title:
First-order formalism for twinlike models with several real scalar
  fields

abstract:
  We investigate the presence of twinlike models in theories described by
several real scalar fields. We focus on the first-order formalism, and we show
how to build distinct scalar field theories that support the same extended
solution, with the same energy density and the very same linear stability. The
results are valid for two distinct classes of generalized models, that include
the standard model and cover a diversity of generalized models of current
interest in high energy physics.


title:
Production of Nickel-56 in black hole-neutron star merger accretion disk
  outflows

abstract:
  The likely outcome of a compact object merger event is a central black hole
surrounded by a rapidly accreting torus of debris. This disk of debris is a
rich source of element synthesis, the outcome of which is needed to predict
electromagnetic counterparts of individual events and to understand the
contribution of mergers to galactic chemical evolution. Here we study disk
outflow nucleosynthesis in the context of a two-dimensional, time-dependent
black hole-neutron star merger accretion disk model. We use two time snapshots
from this model to examine the impact of the evolution of the neutrino fluxes
from the disk on the element synthesis. While the neutrino fluxes from the
early-time disk snapshot appear to favor neutron-rich outflows, by the
late-time snapshot the situation is reversed. As a result we find copious
production of Nickel-56 in the outflows.


title: Estimating a probability mass function with unknown labels

abstract:
  In the context of a species sampling problem we discuss a non-parametric
maximum likelihood estimator for the underlying probability mass function. The
estimator is known in the computer science literature as the high profile
estimator. We prove strong consistency and derive the rates of convergence, for
an extended model version of the estimator. We also study a sieved estimator
for which similar consistency results are derived. Numerical computation of the
sieved estimator is of great interest for practical problems, such as forensic
DNA analysis, and we present a computational algorithm based on the stochastic
approximation of the expectation maximisation algorithm. As an interesting
byproduct of the numerical analyses we introduce an algorithm for bounded
isotonic regression for which we also prove convergence.


title: QCD at imaginary chemical potential with Wilson fermions

abstract:
  We investigate the phase diagram in the temperature, imaginary chemical
potential plane for QCD with three degenerate quark flavors using Wilson type
fermions. While more expensive than the staggered fermions used in past studies
in this area, Wilson fermions can be used safely to simulate systems with three
quark flavors. In this talk, we focus on the (pseudo)critical line that extends
from $\mu=0$ in the imaginary chemical potential plane, trace it to the
Roberge-Weiss line, and determine its location relative to the Roberge-Weiss
transition point. In order to smoothly follow the (pseudo)critical line in this
plane we perform a multi-histogram reweighting in both temperature and chemical
potential. To perform reweighting in the chemical potential we use the
compression formula to compute the determinants exactly. Our results are
compatible with the standard scenario.


title:
Geochemical and planetary dynamical views on the origin of Earth's
  atmosphere and oceans

abstract:
  Earth's volatile elements (H, C, and N) are essential to maintaining
habitable conditions for metazoans and simpler life forms. However, identifying
the sources (comets, meteorites, and trapped nebular gas) that supplied
volatiles to Earth is not straightforward because secondary processes like
mantle degassing, crustal recycling, and escape to space modified the
composition of the atmosphere. Here, we review two complementary approaches to
investigate the origin of Earth's atmosphere and oceans. The geochemical
approach uses volatile element abundances and isotopic compositions to identify
the possible contributors to the atmosphere and to disentangle the processes
that shaped it. In that respect, noble gases (He, Ne, Ar, Kr, and Xe), elements
that are chemically inert and possess several isotopes produced by
radioactivity, play a critical role. The dynamical approach uses our knowledge
of planetary dynamics to track volatile delivery to the Earth, starting with
dust transport in the disk to planet-building processes. The main conclusion is
that Earth acquired most of its major volatile elements by accretion of
planetesimals or embryos akin to volatile-rich meteorites. At the same time,
solar/meteoritic noble gases were captured by embryos and some gases were lost
to space, by hydrodynamic escape and large impacts. Comets did not contribute
much H, C, and N but may have delivered significant noble gases, which could
represent the only fingerprints of the bombardment of our planet with icy
bodies. The processes that governed the delivery of volatile elements to the
Earth are thought to be relatively common and it is likely that Earth-like
planets covered with oceans exist in extra-solar systems.


title:
Quantum s = 1/2 Antiferromagnets on Archimedean Lattices: The Route from
  Semiclassical Magnetic Order to Nonmagnetic Quantum States

abstract:
  We investigate ground states of $s$=1/2 Heisenberg antiferromagnets on the
eleven two-dimensional (2D) Archimedian lattices by using the coupled cluster
method. Magnetic interactions and quantum fluctuations play against each other
subtly in 2D quantum magnets and the magnetic ordering is thus sensitive to the
features of lattice topology. Archimedean lattices are those lattices that have
2D arrangements of regular polygons and they often build the underlying
magnetic lattices of insulating quasi-two-dimensional quantum magnetic
materials. Hence they allow a systematic study of the relationship between
lattice topology and magnetic ordering. We find that the Archimedian lattices
fall into three groups: those with semiclassical magnetic ground-state
long-range order, those with a magnetically disordered (cooperative quantum
paramagnetic) ground state, and those with a fragile magnetic order. The most
relevant parameters affecting the magnetic ordering are the coordination number
and the degree of frustration present.


title: Frequency dependence of the Chiral Vortical Effect

abstract:
  We study the frequency dependence of all the chiral vortical and magnetic
conductivities for a relativistic gas of free chiral fermions and for a
strongly coupled conformal field theory with holographic dual in four
dimensions. Both systems have gauge and gravitational anomalies, and we compute
their contribution to the conductivities. The chiral vortical conductivities
and the chiral magnetic conductivity in the energy current show a frequency
dependence in the form of a delta centered at zero frequency. This highly
discontinuous behavior is a natural consequence of the Ward identities that
include the energy momentum tensor. We discuss the physical interpretation of
this result and its possible implications for the quark gluon plasma as created
in heavy ion collisions. In the Appendix we discuss why the chiral magnetic
effect seems to vanish in the consistent current for a particular
implementation of the axial chemical potential.


title: A Note on the Inducibility of 4-vertex Graphs

abstract:
  There is much recent interest in understanding the density at which constant
size graphs can appear in a very large graph. Specifically, the inducibility of
a graph H is its extremal density, as an induced subgraph of G, where |G| ->
infinity. Already for 4-vertex graphs many questions are still open. Thus, the
inducibility of the 4-path was addressed in a construction of Exoo (1986), but
remains unknown. Refuting a conjecture of Erdos, Thomason (1997) constructed
graphs with a small density of both 4-cliques and 4-anticliques. In this note,
we merge these two approaches and construct better graphs for both problems.


title:
On the properties of input-to-output transformations in networks of
  perceptrons

abstract:
  Information processing in certain neuronal networks in the brain can be
considered as a map of binary vectors, where ones (spikes) and zeros (no
spikes) of input neurons are transformed into spikes and no spikes of output
neurons. A simple but fundamental characteristic of such a map is how it
transforms distances between input vectors. In particular what is the mean
distance between output vectors given certain distance between input vectors?
Using combinatorial approach we found an exact solution to this problem for
networks of perceptrons with binary weights. he resulting formulas allow for
precise analysis how network connectivity and neuronal excitability affect the
transformation of distances between the vectors of neuronal spiking. As an
application, we considered a simple network model of information processing in
the hippocampus, a brain area critically implicated in learning and memory, and
found a combination of parameters for which the output neurons discriminated
similar and distinct inputs most effectively. A decrease of threshold values of
the output neurons, which in biological networks may be associated with
decreased inhibition, impaired optimality of discrimination.


title: Bounding the Maximum of Dependent Random Variables

abstract:
  Let $M_n$ be the maximum of $n$ zero-mean gaussian variables $X_1,..,X_n$
with covariance matrix of minimum eigenvalue $\lambda$ and maximum eigenvalue
$\Lambda$. Then, for $n \ge 70$, $$\Pr\{M_n \ge \lambda \left (2 \log n - 2.5 -
\log(2 \log n - 2.5) \right )^\frac{1}{2} -.68\Lambda\} \ge \frac{1}{2}.$$
Bounds are also given for tail probabilities other than $\frac{1}{2}$. Upper
bounds are given for tail probabilities of the maximum of dependent identically
distributed variables. As an application, the maximum of purely
non-deterministic stationary Gaussian processes is shown to have the same first
order asymptotic behaviour as the maximum of independent gaussian processes.


title: Fundamental groups of random clique complexes

abstract:
  We study fundamental groups of clique complexes associated to random graphs.
We establish thresholds for their cohomological and geometric dimension and
torsion. We also show that in certain regime any aspherical subcomplex of a
random clique complex satisfies the Whitehead conjecture, i.e. all irs
subcomplexes are also aspherical.


title:
An Introduction to Control of Chaos for Quasi-Integrable Hamiltonian
  Systems

abstract:
  Quasi-integrable Hamiltonian systems are of great interest in many research
fields of physics and mathematics. In these systems, the phase space has
regular and chaotic trajectories. These trajectories depend in part on the
magnitude of perturbation that breaks the integrability of the system. The
value of the critical perturbation responsible for this transition is a key
element in the control of chaos .
  In this paper, we explore a procedure for the control in quasi-integrable
Hamiltonian systems via canonical map. Initially, we present the basic tools
for this study: Hamiltonian map, linearization of the map and Chirikov
criterion. Subsequently, we investigated the behavior of a wave-particle
interaction front perturbation. Finally, we confront with a numerical
analytical approach (iteration of the map) results, showing a good agreement.


title:
Two particle-two hole final states in quasi elastic neutrino-nucleus
  interactions

abstract:
  The excitation of two particle-two hole final states in neutrino-nucleus
scattering, not taken into account in Monte Carlo simulations for data
analysis, has been advocated by many authors as the source of the excess cross
section observed by the MiniBooNE collaboration in the quasi elastic channel.
We analyse the mechanisms leading to the appearance of two particle-two hole
states, and show that interference between the amplitudes involving one- and
two-nucleon currents, not consistently included in existing calculations, plays
a major role. A novel approach allowing to treat one- and two-nucleon current
contributions on the same footing is outlined.


title:
Asymptotic normality of fringe subtrees and additive functionals in
  conditioned Galton--Watson trees

abstract:
  We consider conditioned Galton-Watson trees and show asymptotic normality of
additive functionals that are defined by toll functions that are not too large.
This includes, as a special case, asymptotic normality of the number of fringe
subtrees isomorphic to any given tree, and joint asymptotic normality for
several such subtree counts. Another example is the number of protected nodes.
The offspring distribution defining the random tree is assumed to have
expectation 1 and finite variance; no further moment condition is assumed.


title: Effects of divergent ghost loops on the Green's functions of QCD

abstract:
  In the present work we discuss certain characteristic features encoded in
some of the fundamental QCD Green's functions, whose origin can be traced back
to the nonperturbative masslessness of the ghost field, in the Landau gauge.
Specifically, the ghost loops that contribute to these Green's functions
display infrared divergences, akin to those encountered in the perturbative
treatment, in contradistinction to the gluonic loops, whose perturbative
divergences are tamed by the dynamical generation of an effective gluon mass.
In d=4, the aforementioned divergences are logarithmic, thus causing a
relatively mild impact, whereas in d=3 they are linear, giving rise to enhanced
effects. In the case of the gluon propagator, these effects do not interfere
with its finiteness, but make its first derivative diverge at the origin, and
introduce a maximum in the region of infrared momenta. The three-gluon vertex
is also affected, and the induced divergent behavior is clearly exposed in
certain special kinematic configurations, usually considered in lattice
simulations; the sign of the corresponding divergence is unambiguously
determined. The main underlying concepts are developed in the context of a
simple toy model, which demonstrates clearly the interconnected nature of the
various effects. The picture that emerges is subsequently corroborated by a
detailed nonperturbative analysis, combining lattice results with the dynamical
integral equations governing the relevant ingredients, such as the
nonperturbative ghost loop and the momentum-dependent gluon mass.


title: Forcing $k$-repetitions in degree sequences

abstract:
  One of the most basic results in graph theory states that every graph with at
least two vertices has two vertices with the same degree. Since there are
graphs without $3$ vertices of the same degree, it is natural to ask if for any
fixed $k$, every graph $G$ is ``close'' to a graph $G'$ with $k$ vertices of
the same degree. Our main result in this paper is that this is indeed the case.
Specifically, we show that for any positive integer $k$, there is a constant
$C=C(k)$, so that given any graph $G$, one can remove from $G$ at most $C$
vertices and thus obtain a new graph $G'$ that contains at least
$\min\{k,|G|-C\}$ vertices of the same degree.
  Our main tool is a multidimensional zero-sum theorem for integer sequences,
which we prove using an old geometric approach of Alon and Berman.


title: Localization at Large N

abstract:
  We review how localization is used to probe holographic duality and, more
generally, non-perturbative dynamics of four-dimensional N=2 supersymmetric
gauge theories in the planar large-N limit.


title:
Polymer Escape from a Metastable Kramers potential: Path Integral
  Hyperdynamics Study

abstract:
  We study the dynamics of flexible, semiflexible, and self-avoiding polymer
chains moving under a Kramers metastable potential. Due to thermal noise, the
polymers, initially placed in the metastable well, can cross the potential
barrier, but these events are extremely rare if the barrier is much larger than
thermal energy. To speed up the slow rate processes in computer simulations, we
extend the recently proposed path integral hyperdynamics method to the cases of
polymers. We consider the cases where the polymers' radii of gyration are
comparable to the distance between the well bottom and the barrier top. We find
that, for a flexible polymer, the crossing rate ($\mathcal{R}$) monotonically
decreases with chain contour length ($L$), but with the magnitude much larger
than the Kramers rate in the globular limit. For a semiflexible polymer, the
crossing rate decreases with $L$ but becomes nearly constant for large $L$. For
a fixed $L$, the crossing rate becomes maximum at an intermediate bending
stiffness. For a self-avoiding chain, the rate is a nonmonotonic function of
$L$, first decreasing with $L$, and then, above certain length, increasing with
$L$. These findings can be instrumental for efficient separation of
biopolymers.


title:
Complete non-compact gradient Ricci solitons with nonnegative Ricci
  curvature

abstract:
  In this paper, we give a delay estimate of scalar curvature for a complete
non-compact expanding (or steady) gradient Ricci soliton with nonnegative Ricci
curvature. As an application, we prove that any complete non-compact expanding
(or steady) gradient K\"{a}hler-Ricci solitons with positively pinched Ricci
curvature should be Ricci flat. The result answers a question in case of
K\"{a}hler-Ricci solitons proposed by Chow, Lu and Ni in a book.


title:
Measurement of the $\bar{B}_s^0\to D_s^-D_s^+$ and $\bar{B}_s^0\to
  D^-D_s^+$ effective lifetimes

abstract:
  The first measurement of the effective lifetime of the $\bar{B}_s^0$ meson in
the decay $\bar{B}_s^0\to D_s^-D_s^+$ is reported using a proton-proton
collision dataset, corresponding to an integrated luminosity of 3 fb$^{-1}$,
collected by the LHCb experiment. The measured value of the $\bar{B}_s^0\to
D_s^-D_s^+$ effective lifetime is $1.379\pm0.026\pm0.017$ ps, where the
uncertainties are statistical and systematic, respectively. This lifetime
translates into a measurement of the decay width of the light $\bar{B}_s^0$
mass eigenstate of \Gamma_L$=0.725\pm0.014\pm0.009$ ps$^{-1}$. The
$\bar{B}_s^0$ lifetime is also measured using the flavor-specific
$\bar{B}_s^0\to D^-D_s^+$ decay to be $1.52\pm0.15\pm0.01 {\rm ps}$.


title: Phase-Entanglement Complementarity with Time-Energy Uncertainty

abstract:
  We present a unified view of the Berry phase of a quantum system and its
entanglement with surroundings. The former reflects the nonseparability between
a system and a classical environment as the latter for a quantum environment,
and the concept of geometric time-energy uncertainty can be adopted as a
signature of the nonseparability. Based on this viewpoint, we study their
relationship in the quantum-classical transition of the environment, with the
aid of a spin-half particle (qubit) model exposed to a quantum-classical hybrid
field. In the quantum-classical transition, the Berry phase has a similar
connection with the time-energy uncertainty as the case with only a classical
field, whereas the geometric phase for the mixed state of the qubit exhibits a
complementary relationship with the entanglement. Namely, for a fixed
time-energy uncertainty, the entanglement is gradually replaced by the mixed
geometric phase as the quantum field vanishes. And the mixed geometric phase
becomes the Berry phase in the classical limit. The same results can be draw
out from a displaced harmonic oscillator model.


title:
Chiral perturbation theory of muonic hydrogen Lamb shift: polarizability
  contribution

abstract:
  The proton polarizability effect in the muonic-hydrogen Lamb shift comes out
as a prediction of baryon chiral perturbation theory at leading order and our
calculation yields for it: $\Delta E^{(\mathrm{pol})} (2P-2S) = 8^{+3}_{-1}\,
\mu$eV. This result is consistent with most of evaluations based on dispersive
sum rules, but is about a factor of two smaller than the recent result obtained
in {\em heavy-baryon} chiral perturbation theory. We also find that the effect
of $\Delta(1232)$-resonance excitation on the Lamb-shift is suppressed, as is
the entire contribution of the magnetic polarizability; the electric
polarizability dominates. Our results reaffirm the point of view that the
proton structure effects, beyond the charge radius, are too small to resolve
the `proton radius puzzle'.


title: Comparative Study of MHD Modeling of the Background Solar Wind

abstract:
  Knowledge about the background solar wind plays a crucial role in the
framework of space weather forecasting. In-situ measurements of the background
solar wind are only available for a few points in the heliosphere where
spacecraft are located, therefore we have to rely on heliospheric models to
derive the distribution of solar wind parameters in interplanetary space. We
test the performance of different solar wind models, namely Magnetohydrodynamic
Algorithm outside a Sphere/ENLIL (MAS/ENLIL), Wang-Sheeley-Arge/ENLIL
(WSA/ENLIL), and MAS/MAS, by comparing model results with in-situ measurements
from spacecraft located at 1 AU distance to the Sun (ACE, Wind). To exclude the
influence of interplanetary coronal mass ejections (ICMEs), we chose the year
2007 as a time period with low solar activity for our comparison. We found that
the general structure of the background solar wind is well reproduced by all
models. The best model results were obtained for the parameter solar wind
speed. However, the predicted arrival times of high-speed solar wind streams
have typical uncertainties of the order of about one day. Comparison of model
runs with synoptic magnetic maps from different observatories revealed that the
choice of the synoptic map significantly affects the model performance.


title: Neutrino Factory R&D Efforts

abstract:
  Stored-muon-beam neutrino factories have been recognized as the best option
to measure precisely the elements of the MNSP matrix and sensitively test the
consistency of the three-neutrino mixing picture. Now that all three mixing
angles have been shown to be nonzero, the motivation for neutrino factory
construction is strong. A small number of feasibility issues remain open and
are the subject of ongoing R&D. Progress on these R&D efforts is described.


title: Potentials of stable processes

abstract:
  For a stable process, we give an explicit formula for the potential measure
of the process killed outside a bounded interval and the joint law of the
overshoot, undershoot and undershoot from the maximum at exit from a bounded
interval. We obtain the equivalent quantities for a stable process reflected in
its infimum. The results are obtained by exploiting a simple connection with
the Lamperti representation and exit problems of stable processes.


title: Linearization of Poisson Lie group structures

abstract:
  We show that for any coboundary Poisson Lie group G, the Poisson structure on
G^* is linearizable at the group unit. This strengthens a result of
Enriquez-Etingof-Marshall, who had established formal linearizability of G^*
for quasi-triangular Poisson Lie groups G. We also prove linearizability
properties for the group multiplication in G^* and for Poisson Lie group
morphisms, with similar assumptions.


title: Dispersions of ellipsoidal particles in a nematic liquid crystal

abstract:
  Colloidal particles dispersed in a partially ordered medium, such as a liquid
crystal (LC) phase, disturb its alignment and are subject to elastic forces.
These forces are long-ranged, anisotropic and tunable through temperature or
external fields, making them a valuable asset to control colloidal assembly.
The latter is very sensitive to the particle geometry since it alters the
interactions between the colloids. We here present a detailed numerical
analysis of the energetics of elongated objects, namely prolate ellipsoids,
immersed in a nematic host. The results, complemented with qualitative
experiments, reveal novel LC configurations with peculiar topological
properties around the ellipsoids, depending on their aspect ratio and the
boundary conditions imposed on the nematic order parameter. The latter also
determine the preferred orientation of ellipsoids in the nematic field, because
of elastic torques, as well as the morphology of particles aggregates.


title:
Algebraic Principles for Rely-Guarantee Style Concurrency Verification
  Tools

abstract:
  We provide simple equational principles for deriving rely-guarantee-style
inference rules and refinement laws based on idempotent semirings. We link the
algebraic layer with concrete models of programs based on languages and
execution traces. We have implemented the approach in Isabelle/HOL as a
lightweight concurrency verification tool that supports reasoning about the
control and data flow of concurrent programs with shared variables at different
levels of abstraction. This is illustrated on two simple verification examples.


title: Axial anomaly and vector meson dominance model

abstract:
  The dispersive representation of axial anomaly leads to the anomaly sum rules
(ASRs), exact nonperturbative relations in QCD. The analytical continuation of
the ASRs to the time-like region is performed. The transition form factors of
$\pi^0$, $\eta$ and $\eta'$ mesons in this region are calculated. A good
agreement with the available experimental data is found. Based on the ASRs, we
have provided the foundations for the vector meson dominance model in these
processes.


title: The NESSiE Concept for Sterile Neutrinos

abstract:
  Neutrino physics is nowadays receiving more and more attention as a possible
source of information for the long-standing problem of new physics beyond the
Standard Model. The recent measurement of the third mixing angle theta13 in the
standard mixing oscillation scenario encourages us to pursue the still missing
results on leptonic CP violation and absolute neutrino masses. However, several
puzzling measurements exist, which deserve an exhaustive evaluation. The NESSiE
Collaboration has been setup to undertake a definitive experiment to clarify
the muon disappearance measurements at small L/E, which will be able to put
severe constraints to any model with more than the three-standard neutrinos, or
even to robustly measure the presence of a new kind of neutrino oscillation for
the first time. Within the context of the current CERN project, aimed to
revitalize the neutrino field in Europe, we will illustrate the achievements
that can be obtained by a double muon-spectrometer system, with emphasis on the
search for sterile neutrinos.


title:
Determination of $|V_{us}|$ from a lattice-QCD calculation of the
  $K\to\pi\ell\nu$ semileptonic form factor with physical quark masses

abstract:
  We calculate the kaon semileptonic form factor $f_+(0)$ from lattice QCD,
working, for the first time, at the physical light-quark masses. We use gauge
configurations generated by the MILC collaboration with $N_f=2+1+1$ flavors of
sea quarks, which incorporate the effects of dynamical charm quarks as well as
those of up, down, and strange. We employ data at three lattice spacings to
extrapolate to the continuum limit. Our result, $f_+(0) = 0.9704(32)$, where
the error is the total statistical plus systematic uncertainty added in
quadrature, is the most precise determination to date. Combining our result
with the latest experimental measurements of $K$ semileptonic decays, one
obtains the Cabibbo-Kobayashi-Maskawa matrix element
$|V_{us}|=0.22290(74)(52)$, where the first error is from $f_+(0)$ and the
second one is from experiment. In the first-row test of
Cabibbo-Kobayashi-Maskawa unitarity, the error stemming from $|V_{us}|$ is now
comparable to that from $|V_{ud}|$.


title:
Hamiltonian formalism for integer-valued variables and integer time
  steps and a possible application in quantum physics

abstract:
  Most classical mechanical systems are based on dynamical variables whose
values are real numbers. Energy conservation is then guaranteed if the
dynamical equations are phrased in terms of a Hamiltonian function, which then
leads to differential equations in the time variable. If these real dynamical
variables are instead replaced by integers, and also the time variable is
restricted to integers, it appears to be hard to enforce energy conservation
unless one can also derive a Hamiltonian formalism for that case. We here show
how the Hamiltonian formalism works here, and how it may yield the usual
Hamilton equations in the continuum limit. The question was motivated by the
author's investigations of special quantum systems that allow for a
deterministic interpretation. The 'discrete Hamiltonian formalism' appears to
shed new light on these approaches.


title: Local regularity in non-linear generalized functions

abstract:
  In this review article we present regularity properties of generalized
functions which are useful in the analysis of non-linear problems. It is shown
that Schwartz distributions embedded into our new spaces of generalized
functions, with additional properties described through the association, belong
to various classical spaces with finite or infinite type of regularities.


title: The Morse theory of \v{C}ech and Delaunay complexes

abstract:
  Given a finite set of points in $\mathbb R^n$ and a radius parameter, we
study the \v{C}ech, Delaunay-\v{C}ech, Delaunay (or Alpha), and Wrap complexes
in the light of generalized discrete Morse theory. Establishing the \v{C}ech
and Delaunay complexes as sublevel sets of generalized discrete Morse
functions, we prove that the four complexes are simple-homotopy equivalent by a
sequence of simplicial collapses, which are explicitly described by a single
discrete gradient field.


title:
Self-reciprocal functions, powers of the Riemann zeta function and
  modular-type transformations

abstract:
  The classical transformation of Jacobi's theta function admits a simple proof
by producing an integral representation that yields this invariance apparent.
This idea seems to have first appeared in the work of S. Ramanujan. Several
examples of this idea have been produced by Koshlyakov, Ferrar, Guinand,
Ramanujan and others. A unifying procedure to analyze these examples and
natural generalizations is presented.


title:
Analysing radial flow features in p-Pb and p-p collisions at several TeV
  by studying identified particle production in EPOS3

abstract:
  Experimental transverse momentum spectra of identified particles in p-Pb
collisions at 5.02 TeV show many similarities to the corresponding Pb-Pb
results, the latter ones usually being interpreted in term of hydrodynamic
flow. We analyse these data using EPOS3, an event generator based on a 3D+1
viscous hydrodynamical evolution starting from flux tube initial conditions,
which are generated in the Gribov-Regge multiple scattering framework. An
individual scattering is referred to as Pomeron, identified with a parton
ladder, eventually showing up as flux tubes (or strings). Each parton ladder is
composed of a pQCD hard process, plus initial and final state linear parton
emission. Nonlinear effects are considered by using saturation scales $Q_{s}$,
depending on the energy and the number of participants connected to the Pomeron
in question. We compute transverse momentum ($p_{t}$) spectra of pions, kaons,
protons, lambdas, and $\Xi$ baryons in p-Pb and p-p scattering, compared to
experimental data and many other models. In this way we show in a quantitative
fashion that p-Pb data (and even p-p ones) show the typical ``flow effect'' of
enhanced particle production at intermediate $p_{t}$ values, more and more
visible with increasing hadron mass.


title: On the edge-reconstruction number of a tree

abstract:
  The edge-reconstruction number ern$(G)$ of a graph $G$ is equal to the
minimum number of edge-deleted subgraphs $G-e$ of $G$ which are sufficient to
determine $G$ up to isomorphsim. Building upon the work of Molina and using
results from computer searches by Rivshin and more recent ones which we carried
out, we show that, apart from three known exceptions, all bicentroidal trees
have edge-reconstruction number equal to 2. We also exhibit the known trees
having edge-reconstruction number equal to 3 and we conjecture that the three
infinite families of unicentroidal trees which we have found to have
edge-reconstruction number equal to 3 are the only ones.


title:
Universal scaling of three-dimensional bosonic gases in a trapping
  potential

abstract:
  We investigate the critical properties of cold bosonic gases in three
dimensions, confined by an external quadratic potential coupled to the particle
density, and realistically described by the Bose-Hubbard (BH) model. The
trapping potential is often included in experiments with cold atoms and
modifies the critical finite-size scaling of the homogeneous system in a non
trivial way. The trap-size scaling (TSS) theory accounts for this effect
through the exponent $\theta$.
  We perform extensive simulations of the BH model at the critical temperature,
in the presence of harmonic traps. We find that the TSS predictions are
universal once we account for the effective way in which the trap locally
modifies the chemical potential $\mu$ of the system. The trap exponent for the
BH model at $\mu=0$ is the one corresponding to an effective quartic potential.
At positive $\mu$, evidence suggests that TSS breaks down sufficiently far from
the centre of the trap, as the system encounters an effective phase boundary.


title:
Helicity of mean and turbulent flow with coherent structures in
  Rayleigh-Benard convective cell

abstract:
  We present results of the study of a turbulent air flow with a large scale
circulation in Rayleigh-Benard rectangular convective cell with a heated bottom
wall and a cooled top wall. The mean horizontal velocity of the main roll and
the mean vorticity of eddy rings are almost aligned in a large part of the
flow. The helicity of the mean flow is quite high, and is the source of
turbulent helicity. Since helicity of the mean flow and turbulence is quite
large, the flow in Rayleigh-Benard convective cell is well suited to study
properties of helical turbulence.


title: 8-rank of the class group and isotropy index

abstract:
  Suppose $F=\mathbb{Q}(\sqrt{-p_1\dotsm p_t})$ is an imaginary quadratic
number field with distinct primes $p_1,\dots,p_{t}$, where $p_i\equiv
1\pmod{4}$ ($i=1,\dots,t-1$) and $p_t\equiv 3\pmod{4}$. We express the possible
values of the 8-rank $r_8$ of the class group of $F$ in terms of a quadratic
form $Q$ over $\mathbb{F}_2$ which is defined by quartic symbols. In
particular, we show that $r_8$ is bounded by the isotropy index of $Q$.


title: Polychromatic polariton laser selector switch

abstract:
  Integration of optical elements into scalable chips has been at the center of
a large effort in recent years. Concurrently, the separation between the
diverse functions, namely switches, detectors or emitters increases
significantly the final number of components on chip. Such technical
limitations may be overcome by introducing agile devices able, for example, to
simultaneously detect, process and emit a coherent signal. Such a pathway has
been explored with different approaches that bear advantages and drawbacks.
Polaritons have often been proposed as promising candidates for multifunctional
devices. Here we present an optical switch based on polariton lasing. An
incident monochromatic signal is channeled into several polariton laser beams
at different wavelengths by a novel relaxation mechanism which combines
bistability, phonon interactions, long polariton lifetime and bosonic
stimulation. We demonstrate spin logic operations conserving the original
polarization state that is fully imprinted onto the coherently emitted signals.


title:
Representations for the Drazin inverse of the generalized Schur
  complement

abstract:
  In this paper we present expressions for the Drazin inverse of the
generalized Schur complement $A-CD^{d}B$ in terms of the Drazin inverses of $A$
and the generalized Schur complement $D-BA^{d}C$ under less and weaker
restrictions, which generalize several results in the literature and the
formula of Sherman-Morrison-Woodbury type.


title: Tensor Properties of the Magneto-electric Coupling in Hexaferrites

abstract:
  Recent data reported on the magneto-electric coupling,{\alpha}, of
hexaferrite materials is very high, and they have the potential to impact
future technologies in a major way. The fundamental question addressed in this
paper is what does {\alpha} depend on and, therefore, to what extent can
{\alpha} increase in future experiments. Mathematical formulation of a
microscopic theory would be rather complex, especially for a complex crystal
structure as the Z-type hexaferrite, for example. We have opted for a
thermodynamic argument in which a functional relationship between {\alpha} and
material parameters was derived. We find that {\alpha} is best described as a
tensor property proportional to the product of the magnetostriction and
piezoelectric strain tensors. Quantitative estimates of {\alpha} are given for
hexaferrites and composites.


title:
X-ray monitoring of classical novae in the central region of M31. III.
  Autumn and winter 2009/10, 2010/11 and 2011/12

abstract:
  [Abridged] Classical novae (CNe) represent the major class of supersoft X-ray
sources (SSSs) in the central region of our neighbouring galaxy M31. We
performed a dedicated monitoring of the M31 central region, aimed to detect SSS
counterparts of CNe, with XMM-Newton and Chandra between Nov and Mar of the
years 2009/10, 2010/11 and 2011/12. In total we detected 24 novae in X-rays.
Seven of these sources were known from previous observations, including the M31
nova with the longest SSS phase, M31N~1996-08b, which was found to fade below
our X-ray detection limit 13.8 yr after outburst. Of the new discoveries
several novae exhibit significant variability in their short-term X-ray light
curves with one object showing a suspected period of about 1.3 h. We studied
the SSS state of the most recent outburst of a recurrent nova which had
previously shown the shortest time ever observed between two outbursts (about 5
yr). The total number of M31 novae with X-ray counterpart was increased to 79
and we subjected this extended catalogue to detailed statistical studies. Four
previously indicated correlations between optical and X-ray parameters could be
confirmed and improved. We found indications that the multi-dimensional
parameter space of nova properties might be dominated by a single physical
parameter. We discuss evidence for a different X-ray behaviour of novae in the
M31 bulge and disk. Exploration of the multi-wavelength parameter space of
optical and X-ray measurements is shown to be a powerful tool for examining
properties of extragalactic nova populations. While there are hints that the
different stellar populations of M31 (bulge vs disk) produce dissimilar nova
outbursts, there is also growing evidence that the overall behaviour of an
average nova might be understood in surprisingly simple terms.


title: Practical Cosmology with Lenses

abstract:
  Surveys with submillimetre telescopes are revealing large numbers of
gravitationally lensed high-redshift sources. I describe how, in practice,
these lensed systems could be simultaneously used to estimate the values of
cosmological parameters, test models for the evolution of the distribution of
dark-matter halos and investigate the properties of the source population. Even
the existing sample of lenses found with the Hershcel Space Observatory is
enough to formally rule out the standard models of the evolving population of
dark-matter halos, with the likely explanation a combination of baryon physics
and the perturbation by infalling baryons of the density distribution of dark
matter at the centres of the halos. Independently of the evolution of the
halos, observations of a sample of 100 lensed systems would be enough to
estimate Omega_Lambda with a precision of 5% and observations of 1000 lenses
would be enough to estimate w, the parameter in the equation-of-state of dark
energy, with a precision similar to that obtained from the Planck observations
of the cosmic microwave background. While the fraction of submillimetre sources
that are lensed depends weakly on the specific halo mass function that is used
in the model, it depends very strongly on the evolution of the submillimetre
luminosity function of the source population. Therefore measurements of the
lensing fraction could be used to investigate galaxy evolution in a way that is
independent of the properties of the intervening halos.


title:
Pricing Residential Electricity Based on Individual Consumption
  Behaviors

abstract:
  The conventional practice of retail electric utilities is to aggregate
customers geographically. The utility purchases electricity for its customers
via bulk transactions on the wholesale market, and it passes these costs along
to its customers, the end consumers, through their rate plan. Typically, all
residential consumers are offered the same per unit rate plan, which leads to
cost sharing. Some consumers use their electricity at peak hours, when it is
more expensive on the wholesale market, and others consume mostly at off peak
hours, when it is cheaper, but they all enjoy the same per unit rate through
their utility. This paper proposed a method for the utility to segment a
population of consumers on the basis of their individual consumption patterns.
An optimal recruitment algorithm was developed to aggregate consumers into
groups with a relatively low per unit cost of electricity on the wholesale
market. It was then proposed that the utility should group together enough
consumers to ensure an adequately low forecast error, which is related to risks
it faces in wholesale market transactions. Finally, it was shown that by
repeated application of this process, the utility could segment the entire
population into groups and offer them differentiated rate plans based on their
actual consumption behavior. These groupings are stable in the sense that no
one consumer can unilaterally improve her outcome.


title: Chebushev Greedy Algorithm in convex optimization

abstract:
  Chebyshev Greedy Algorithm is a generalization of the well known Orthogonal
Matching Pursuit defined in a Hilbert space to the case of Banach spaces. We
apply this algorithm for constructing sparse approximate solutions (with
respect to a given dictionary) to convex optimization problems. Rate of
convergence results in a style of the Lebesgue-type inequalities are proved.


title: Quantum Error Correction During 50 Gates

abstract:
  Fault tolerant protocol assumes the application of error correction after
every quantum gate. However, correcting errors is costly in terms of time and
number of qubits. Here we demonstrate that quantum error correction can be
applied significantly less often with only a minimal loss of fidelity. This is
done by simulating the implementation of 50 encoded, single-qubit, quantum
gates within the [[7,1,3]] quantum error correction code in a noisy,
non-equiprobable Pauli error environment with error correction being applied at
different intervals. We find that applying error correction after every gate is
rarely optimal and even applying error correction only once after all 50 gates,
though not generally optimal, sacrifices only a slight amount of fidelity with
the benefit of 50-fold saving of resources. In addition, we find that in cases
where bit-flip errors are dominant, it is best not to apply error correction at
all.


title:
Thermodynamics of currents in nonequilibrium diffusive systems: theory
  and simulation

abstract:
  Understanding the physics of nonequilibrium systems remains as one of the
major challenges of theoretical physics. This problem can be cracked in part by
investigating the macroscopic fluctuations of the currents characterizing
nonequilibrium behavior, their statistics and associated structures. This
fundamental line of research has been severely hampered by the overwhelming
complexity of this problem. However, during the last years two new general
methods have appeared to investigate fluctuating behavior that are changing
radically our understanding of nonequilibrium physics: a powerful macroscopic
fluctuation theory (MFT) and a set of advanced computational techniques to
measure rare events. In this work we study the statistics of current
fluctuations in nonequilibrium diffusive systems, using macroscopic fluctuation
theory as theoretical framework, and advanced Monte Carlo simulations of
several stochastic lattice gases as a laboratory to test the emerging picture.
Our quest will bring us from (1) the confirmation of an additivity conjecture
in one and two dimensions, which considerably simplifies the MFT complex
variational problem to compute the thermodynamics of currents, to (2) the
discovery of novel isometric fluctuation relations, which opens an unexplored
route toward a deeper understanding of nonequilibrium physics by bringing
symmetry principles to the realm of fluctuations, and to (3) the observation of
coherent structures in fluctuations, which appear via dynamic phase transitions
involving a spontaneous symmetry breaking event at the fluctuating level. The
clear-cut observation, measurement and characterization of these unexpected
phenomena, well described by MFT, strongly support this theoretical scheme as
the natural theory to understand the thermodynamics of currents in
nonequilibrium diffusive media, opening new avenues of research in
nonequilibrium physics.

categories: cond-mat.stat-mech math-ph math.MP physics.bio-ph


title:
Tunable strong nonlinearity of a micromechanical beam embedded in a
  dc-SQUID

abstract:
  We present a study of the controllable nonlinear dynamics of a
micromechanical beam coupled to a dc-SQUID (superconducting quantum
interference device). The coupling between these systems places the modes of
the beam in a highly nonlinear potential, whose shape can be altered by varying
the control parameters of the SQUID. We detect the position of the beam by
placing it in an optical cavity, which frees the SQUID to be used solely for
actuation. This enables us to probe the previously unexplored full parameter
space of this device. We measure the frequency response of the beam and find
that it displays a periodic dependence on applied magnetic flux. To account for
this, we develop a model based on the standard theory for SQUID dynamics. In
addition, with the aim of understanding if the device can reach nonlinearity at
the single phonon level, we use this model to show that the responsivity of the
current circulating in the SQUID to the position of the beam can become
divergent, with its magnitude limited only by noise. This suggests a direction
for the generation of macroscopically distinguishable superposition states of
the beam.


title:
ALMA reveals a warm and compact starburst around a heavily obscured
  supermassive black hole at z=4.75

abstract:
  We report ALMA Cycle 0 observations at 1.3mm of LESS J033229.4-275619
(XID403), an Ultraluminous Infrared Galaxy at $z=4.75$ in the Chandra Deep
Field South hosting a Compton-thick QSO. The source is not resolved in our data
at a resolution of $\sim$0.75 arcsec, placing an upper-limit of 2.5 kpc to the
half-light radius of the continuum emission from heated-dust. After
deconvolving for the beam size, however, we found a $\sim3\sigma$ indication of
an intrinsic source size of $0.27\pm0.08$ arcsec (Gaussian FWHM), which would
correspond to $r_{half}\sim0.9\pm0.3$ kpc. We build the far-IR SED of XID403 by
combining datapoints from both ALMA and Herschel and fit it with a modified
blackbody spectrum. For the first time, we measure the dust temperature
$T_d=58.5\pm5.3$ K in this system, which is comparable to what has been
observed in other high-z submillimeter galaxies. The measured star formation
rate is SFR=$1020\pm150$ $M_{\odot}$ yr$^{-1}$, in agreement with previous
estimates at lower S/N. Based on the measured SFR and source size, we constrain
the SFR surface density to be $\Sigma_{SFR}>26\;M_{\odot}$yr$^{-1}$kpc$^{-2}$
($\sim200\;M_{\odot}$yr$^{-1}$kpc$^{-2}$ for $r_{half}\sim0.9$ kpc). The
compactness of this starburst is comparable to what has been observed in other
local and high-z starburst galaxies. If the gas mass measured from previous
[CII] and CO(2-1) observations at low resolution is confined within the same
dust region, assuming $r_{half}\sim0.9\pm0.3$ kpc, this would produce a column
density of $N_H\sim0.3-1.1\times10^{24}$cm$^{-2}$ towards the central SMBH,
similar to the column density of $\approx1.4\times10^{24}$cm$^{-2}$ measured
from the X-rays. Then, in principle, if both gas and dust were confined on
sub-kpc scales, this would be sufficient to produce the observed X-ray column
density without any need of a pc-scale absorber [abridged].


title: Unusual Broad-Line MgII Emitters Among Luminous Galaxies in BOSS

abstract:
  Many classes of active galactic nuclei (AGN) have been observed and recorded
since the discovery of Seyfert galaxies. In this paper, we examine the sample
of luminous galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS). We
find a potentially new observational class of AGN, one with strong and broad
MgII $2799$\AA\ line emission, but very weak emission in other normal
indicators of AGN activity, such as the broad line H$\alpha$, H$\beta$, and the
near-ultraviolet AGN continuum, leading to an extreme ratio of broad
H$\alpha$/MgII flux relative to normal quasars. Meanwhile, these objects'
narrow-line flux ratios reveal AGN narrow-line regions with levels of activity
consistent with the MgII fluxes and in agreement with that of normal quasars.
These AGN may represent an extreme case of the Baldwin effect, with very low
continuum and high equivalent width relative to typical quasars, but their
ratio of broad MgII to broad Balmer emission remains very unusual. They may
also be representative of a class of AGN where the central engine is observed
indirectly with scattered light. These galaxies represent a small fraction of
the total population of luminous galaxies ($\simeq 0.1$\%), but are more likely
(about 3.5 times) to have AGN-like nuclear line emission properties than other
luminous galaxiess. Because MgII is usually inaccessible for the population of
nearby galaxies, there may exist a related population of broad-line MgII
emitters in the local universe which are currently classified as narrow-line
emitters (Seyfert 2s) or LINERs.


title: FIP AND FCP products of ring morphisms

abstract:
  We characterize some types of FIP and FCP ring extensions $R \subset S$,
where $S$ is not an integral domain and $R$ may not be an integral domain. In
this paper S is mostly a product of rings related to R and also the
idealization of an R-module.


title:
Non-Gaussianity of the Cosmic Infrared Background anisotropies I :
  Diagrammatic formalism and application to the angular bispectrum

abstract:
  We present the first halo model based description of the Cosmic Infrared
Background (CIB) non-Gaussianity (NG) that is fully parametric. To this end, we
introduce, for the first time, a diagrammatic method to compute high order
polyspectra of the 3D galaxy density field. It allows an easy derivation and
visualisation of the different terms of the polyspectrum. We apply this
framework to the power spectrum and bispectrum, and we show how to project them
on the celestial sphere in the purpose of the application to the CIB angular
anisotropies. Furthermore, we show how to take into account the particular case
of the shot noise terms in that framework. Eventually, we compute the CIB
angular bispectrum at 857 GHz and study its scale and configuration
dependencies, as well as its variations with the halo occupation distribution
parameters. Compared to a previously proposed empirical prescription, such
physically motivated model is required to describe fully the CIB anisotropies
bispectrum. Finally, we compare the CIB bispectrum with the bispectra of other
signals potentially present at microwave frequencies, which hints that
detection of CIB NG should be possible above 220 GHz.


title:
Non-Gaussianity of the Cosmic Infrared Background anisotropies II :
  Predictions of the bispectrum and constraints forecast

abstract:
  Using a full analytical computation of the bispectrum based on the halo model
together with the halo occupation number, we derive the bispectrum of the cos-
mic infrared background (CIB) anisotropies that trace the clustering of
dusty-star- forming galaxies. We focus our analysis on wavelengths in the
far-infrared and the sub-millimeter typical of the Planck/HFI and
Herschel/SPIRE instruments, 350, 550, 850, and 1380 um. We explore the
bispectrum behaviour as a function of several models of evolution of galaxies
and show that it is strongly sensitive to that ingredient. Contrary to the
power spectrum, the bispectrum, at the four wavelengths, seems dominated by low
redshift galaxies. Such a contribution can be hardly limited by applying low
flux cuts. We also discuss the contributions of halo mass as a function of the
redshift and the wavelength, recovering that each term is sensitive to a
different mass range. Furthermore, we show that the CIB bispectrum is a strong
contaminant of the Cosmic Microwave Background bispectrum at 850 um and higher.
Finally, a Fisher analysis of the power spectrum, bispectrum alone and of the
combination of both shows that degeneracies on the HOD parameters are broken by
including the bispectrum information, leading to tight constraints even when
including foreground residuals.


title: On the annihilators and attached primes of top local cohomology modules

abstract:
  Let \frak a be an ideal of a commutative Noetherian ring R and M a finitely
generated R-module. It is shown that {\rm Ann}_R(H_{\frak a}^{{\dim M}({\frak
a}, M)}(M))= {\rm Ann}_R(M/T_R({\frak a}, M)), where T_R({\frak a}, M) is the
largest submodule of M such that {\rm cd}({\frak a}, T_R({\frak a}, M))< {\rm
cd}({\frak a}, M). Several applications of this result are given. Among other
things, it is shown that there exists an ideal \frak b of R such that {\rm
Ann}_R(H_{\frak a}^{\dim M}(M))={\rm Ann}_R(M/H_{\frak b}^{0}(M)). Using this,
we show that if H_{\frak a}^{\dim R}(R)=0, then {\rm Att}_RH^{{\dim
R}-1}_{\frak a}(R)=\{{\frak p}\in {\rm Spec}\,R|\,{\rm cd}({\frak a}, R/{\frak
p})={\dim R}-1\}. These generalize the main results of \cite[Theorem 2.6]{BAG},
\cite[Theorem 2.3]{He} and \cite[Theorem 2.4]{Lyn}.


title: Parallel matrix factorization for low-rank tensor completion

abstract:
  Higher-order low-rank tensors naturally arise in many applications including
hyperspectral data recovery, video inpainting, seismic data recon- struction,
and so on. We propose a new model to recover a low-rank tensor by
simultaneously performing low-rank matrix factorizations to the all-mode ma-
tricizations of the underlying tensor. An alternating minimization algorithm is
applied to solve the model, along with two adaptive rank-adjusting strategies
when the exact rank is not known.
  Phase transition plots reveal that our algorithm can recover a variety of
synthetic low-rank tensors from significantly fewer samples than the compared
methods, which include a matrix completion method applied to tensor recovery
and two state-of-the-art tensor completion methods. Further tests on real-
world data show similar advantages. Although our model is non-convex, our
algorithm performs consistently throughout the tests and give better results
than the compared methods, some of which are based on convex models. In
addition, the global convergence of our algorithm can be established in the
sense that the gradient of Lagrangian function converges to zero.


title: A short note on exponential-time algorithms for hybridization number

abstract:
  In this short note we prove that, given two (not necessarily binary) rooted
phylogenetic trees T_1, T_2 on the same set of taxa X, where |X|=n, the
hybridization number of T_1 and T_2 can be computed in time O^{*}(2^n) i.e.
O(2^{n} poly(n)). The result also means that a Maximum Acyclic Agreement Forest
(MAAF) can be computed within the same time bound.


title: Lift in the 3-sphere of knots and links in lens spaces

abstract:
  An important geometric invariant of links in lens spaces is the lift in the
3-sphere of a link $L$ in $L(p,q)$, that is the counterimage $\widetilde L$ of
$L$ under the universal covering of $L(p,q)$. If lens spaces are defined as a
lens with suitable boundary identifications, then a link in $L(p,q)$ can be
represented by a disk diagram, that is to say, a regular projection of the link
on a disk. Starting from a disk diagram of $L$, we obtain a diagram of the lift
$\widetilde L$ in the 3-sphere. With this construction we are able to find
different knots and links in $L(p,q)$ having equivalent lifts, that is to say,
we cannot distinguish different links in lens spaces only from their lift.


title:
Logarithmic asymptotics of the densities of SPDEs driven by spatially
  correlated noise

abstract:
  We consider the family of stochastic partial differential equations indexed
by a parameter $\eps\in(0,1]$, \begin{equation*} Lu^{\eps}(t,x) =
\eps\sigma(u^\eps(t,x))\dot{F}(t,x)+b(u^\eps(t,x)), \end{equation*}
$(t,x)\in(0,T]\times\Rd$ with suitable initial conditions. In this equation,
$L$ is a second-order partial differential operator with constant coefficients,
$\sigma$ and $b$ are smooth functions and $\dot{F}$ is a Gaussian noise, white
in time and with a stationary correlation in space. Let $p^\eps_{t,x}$ denote
the density of the law of $u^\eps(t,x)$ at a fixed point
$(t,x)\in(0,T]\times\Rd$. We study the existence of $\lim_{\eps\downarrow 0}
\eps^2\log p^\eps_{t,x}(y)$ for a fixed $y\in\R$. The results apply to a class
of stochastic wave equations with $d\in\{1,2,3\}$ and to a class of stochastic
heat equations with $d\ge1$.


title:
Flexible and Extensible Digital Object and Repository Architecture
  (FEDORA)

abstract:
  We describe a digital object and respository architecture for storing and
disseminating digital library content. The key features of the architecture
are: (1) support for heterogeneous data types; (2) accommodation of new types
as they emerge; (3) aggregation of mixed, possibly distributed, data into
complex objects; (4) the ability to specify multiple content disseminations of
these objects; and (5) the ability to associate rights management schemes with
these disseminations. This architecture is being implemented in the context of
a broader research project to develop next-generation service modules for a
layered digital library architecture.


title: Gradings on composition superalgebras

abstract:
  We classify up to equivalence the gradings on Hurwitz superalgebras and on
symmetric composition superalgebras, over any field. Also, classifications up
to isomorphism are given in case the field is algebraically closed. By grading,
here we mean group grading.


title: Policy-Carrying, Policy-Enforcing Digital Objects

abstract:
  We describe the motivation for moving policy enforcement for access control
down to the digital object level. The reasons for this include handling of
item-specific behaviors, adapting to evolution of digital objects, and
permitting objects to move among repositories and portable devices. We then
describe our experiments that integrate the Fedora architecture for digital
objects and repositories and the PoET implementation of security automata to
effect such objectcentric policy enforcement.


title: Decision problems, complexity, traces, and representations

abstract:
  In this article, we study connections between representation theory and
efficient solutions to the conjugacy problem on finitely generated groups. The
main focus is on the conjugacy problem in conjugacy separable groups, where we
measure efficiency in terms of the size of the quotients required to
distinguish a distinct pair of conjugacy classes.


title: The geometry of variations in Batalin-Vilkovisky formalism

abstract:
  This is a paper about geometry of (iterated) variations. We explain why no
sources of divergence are built into the Batalin-Vilkovisky (BV) Laplacian,
whence there is no need to postulate any ad hoc conventions such as
"$\delta(0)=0$" and "$\log\delta(0)=0$" within BV-approach to quantisation of
gauge systems. Remarkably, the geometry of iterated variations does not refer
at all to the construction of Dirac's $\delta$-function as a limit of smooth
kernels. We illustrate the reasoning by re-deriving - but not just "formally
postulating" - the standard properties of BV-Laplacian and Schouten bracket and
by verifying their basic inter-relations (e.g., cohomology preservation by
gauge symmetries of the quantum master-equation).


title:
One-neutron knockout reaction of 17C on a hydrogen target at 70
  MeV/nucleon

abstract:
  First experimental evidence of the population of the first 2- state in 16C
above the neutron threshold is obtained by neutron knockout from 17C on a
hydrogen target. The invariant mass method combined with in-beam gamma-ray
detection is used to locate the state at 5.45(1) MeV. Comparison of its
populating cross section and parallel momentum distribution with a Glauber
model calculation utilizing the shell-model spectroscopic factor confirms the
core-neutron removal nature of this state. Additionally, a previously known
unbound state at 6.11 MeV and a new state at 6.28(2) MeV are observed. The
position of the first 2- state, which belongs to a member of the lowest-lying
p-sd cross shell transition, is reasonably well described by the shell-model
calculation using the WBT interaction.


title:
A Cheeger-Mueller theorem for symmetric bilinear torsions on manifolds
  with boundary

abstract:
  In this paper, we extend Su-Zhang's Cheeger-Mueller type theorem for
symmetric bilinear torsions to manifolds with boundary in the case that the
Riemannian metric and the non-degenerate symmetric bilinear form are of product
structure near the boundary. Our result also extends Bruening-Ma's
Cheeger-Mueller type theorem for Ray-Singer metric on manifolds with boundary
to symmetric bilinear torsions in product case. We also compare it with the
Ray-Singer analytic torsion on manifolds with boundary.


title: HD 106906 b: A planetary-mass companion outside a massive debris disk

abstract:
  We report the discovery of a planetary-mass companion, HD 106906 b, with the
new Magellan Adaptive Optics (MagAO) + Clio2 system. The companion is detected
with Clio2 in three bands: $J$, $K_S$, and $L^\prime$, and lies at a projected
separation of 7.1'' (650 AU). It is confirmed to be comoving with its $13\pm2$
Myr-old F5 host using Hubble Space Telescope/Advanced Camera for Surveys
astrometry over a time baseline of 8.3 yr. DUSTY and COND evolutionary models
predict the companion's luminosity corresponds to a mass of $11\pm2 M_{Jup}$,
making it one of the most widely separated planetary-mass companions known. We
classify its Magellan/Folded-Port InfraRed Echellette $J/H/K$ spectrum as
L$2.5\pm1$; the triangular $H$-band morphology suggests an intermediate surface
gravity. HD 106906 A, a pre-main-sequence Lower Centaurus Crux member, was
initially targeted because it hosts a massive debris disk detected via infrared
excess emission in unresolved Spitzer imaging and spectroscopy. The disk
emission is best fit by a single component at 95 K, corresponding to an inner
edge of 15-20 AU and an outer edge of up to 120 AU. If the companion is on an
eccentric ($e>0.65$) orbit, it could be interacting with the outer edge of the
disk. Close-in, planet-like formation followed by scattering to the current
location would likely disrupt the disk and is disfavored. Furthermore, we find
no additional companions, though we could detect similar-mass objects at
projected separations $>35$ AU. In situ formation in a binary-star-like process
is more probable, although the companion-to-primary mass ratio, at $<1\%$, is
unusually small.


title: Comments on Ionization Cooling Channel Characteristics

abstract:
  Ionization cooling channels with a wide variety of characteristics and
cooling properties are being developed. These channels can produce cooling
performances that are largely consistent with the ionization cooling theory
developed previously. In this paper we review ionization cooling theory,
discuss its application to presently developing cooling channels, and discuss
criteria for optimizing cooling.


title: On symmetry and topological origin of Weyl particles

abstract:
  We suggest that the Weil spinors originate from the multi - component fermion
fields. Those fields belong to the unusual theory that, presumably, exists at
extremely high energies. In this theory there is no Lorentz symmetry. Moreover,
complex numbers are not used in the description of its dynamics. Namely, the
one - particle wave functions are real - valued, the functional integral that
describes the second - quantised theory does not contain the imaginary unit as
well. In the low energy effective theory the two - component Weil spinors
appear. Their appearance is related to the Atiyah-Bott-Shapiro construction and
to the expansion of the real matrix near the topologically protected nodes in
three dimensional momentum space. The complex numbers entering ordinary quantum
mechanics emerge together with the Weil fermions. In this pattern gauge fields
and gravitational fields appear as certain collective excitations (of the
original theory) experienced by the low - energy Weil fermions.


title:
Combining List Experiment and Direct Question Estimates of Sensitive
  Behavior Prevalence

abstract:
  Survey respondents may give untruthful answers to sensitive questions when
asked directly. In recent years, researchers have turned to the list experiment
(also known as the item count technique) to overcome this difficulty. While
list experiments may be less prone to bias than direct questioning, list
experiments are also more susceptible to sampling variability. We show that
researchers do not have to abandon direct questioning altogether in order to
gain the advantages of list experimentation. We develop a nonparametric
estimator of the prevalence of sensitive behaviors that combines list
experimentation and direct questioning. We prove that this estimator is
asymptotically more efficient than the standard difference-in-means estimator,
and we provide a basis for inference using Wald-type confidence intervals.
Additionally, leveraging information from the direct questioning, we derive two
nonparametric placebo tests of the identifying assumptions for the list
experiment. We demonstrate the effectiveness of our combined estimator and
placebo tests with an original survey experiment.


title: Feynman Categories

abstract:
  In this paper we give a new foundational, categorical formulation for
operations and relations and objects parameterizing them. This generalizes and
unifies the theory of operads and all their cousins including but not limited
to PROPs, modular operads, twisted (modular) operads, properads, hyperoperads,
their colored versions, as well as algebras over operads and an abundance of
other related structures, such as crossed simplicial groups, the augmented
simplicial category or FI--modules.
  The usefulness of this approach is that it allows us to handle all the
classical as well as more esoteric structures under a common framework and we
can treat all the situations simultaneously. Many of the known constructions
simply become Kan extensions.
  In this common framework, we also derive universal operations, such as those
underlying Deligne's conjecture, construct Hopf algebras as well as perform
resolutions, (co)bar transforms and Feynman transforms which are related to
master equations. For these applications, we construct the relevant model
category structures. This produces many new examples.


title:
A comparison of nonlinear mixing models for vegetated areas using
  simulated and real hyperspectral data

abstract:
  Spectral unmixing is a crucial processing step when analyzing hyperspectral
data. In such analysis, most of the work in the literature relies on the widely
acknowledged linear mixing model to describe the observed pixels.
Unfortunately, this model has been shown to be of limited interest for specific
scenes, in particular when acquired over vegetated areas. Consequently, in the
past few years, several nonlinear mixing models have been introduced to take
nonlinear effects into account while performing spectral unmixing. These models
have been proposed empirically, however without any thorough validation. In
this paper, the authors take advantage of two sets of real and physical-based
simulated data to validate the accuracy of various nonlinear models in
vegetated areas. These physics-based and analysis models, and their
corresponding unmixing algorithms, are evaluated with respect to their ability
of fitting the measured spectra and of providing an accurate estimation of the
abundance coefficients, considered as the spatial distribution of the materials
in each pixel.


title: Total cross sections and $\rho$ at high energy

abstract:
  Analysis of the new experimental data obtained by the TOTEM Collaboration at
LHC at $\sqrt{s} = 7 \ $TeV at small momentum transfer is presented. The impact
of the different assumptions on the extraction of the parameters of the elastic
scattering amplitude, especially on the size of the total cross sections, is
examined. It is shown that the contribution of the Coulomb amplitude and
Coulomb-hadron interference term should be taken into account in the analysis
of the existing experimental data at small momentum transfer. Our new method of
extracting the real part of the hadron scattering amplitude from experimental
data shows the inconsistency of the size of $\rho=0.14$ to the parameters of
the imaginary part of the hadron scattering amplitude obtained by the TOTEM
Collaboration. The analysis of the data is compared with the similar analysis
in the Regge approach for the hadron scattering amplitude.


title:
The Morita-equivalence between MV-algebras and abelian $\ell$-groups
  with strong unit

abstract:
  We show that the theory of MV-algebras is Morita-equivalent to that of
abelian $\ell$-groups with strong unit. This generalizes the well-known
equivalence between the categories of set-based models of the two theories
established by D. Mundici in 1986, and allows to transfer properties and
results across them by using the methods of topos theory. We discuss several
applications, including a sheaf-theoretic version of Mundici's equivalence and
a bijective correspondence between the geometric theory extensions of the two
theories.


title:
Design and Analysis of an Estimation of Distribution Approximation
  Algorithm for Single Machine Scheduling in Uncertain Environments

abstract:
  In the current work we introduce a novel estimation of distribution algorithm
to tackle a hard combinatorial optimization problem, namely the single-machine
scheduling problem, with uncertain delivery times. The majority of the existing
research coping with optimization problems in uncertain environment aims at
finding a single sufficiently robust solution so that random noise and
unpredictable circumstances would have the least possible detrimental effect on
the quality of the solution. The measures of robustness are usually based on
various kinds of empirically designed averaging techniques. In contrast to the
previous work, our algorithm aims at finding a collection of robust schedules
that allow for a more informative decision making. The notion of robustness is
measured quantitatively in terms of the classical mathematical notion of a norm
on a vector space. We provide a theoretical insight into the relationship
between the properties of the probability distribution over the uncertain
delivery times and the robustness quality of the schedules produced by the
algorithm after a polynomial runtime in terms of approximation ratios.


title:
Weakly driven anomalous diffusion in non-ergodic regime: an analytical
  solution

abstract:
  We derive the probability density of a diffusion process generated by
nonergodic velocity fluctuations in presence of a weak potential, using the
Liouville equation approach. The velocity of the diffusing particle undergoes
dichotomic fluctuations with a given distribution $\psi(\tau)$ of residence
times in each velocity state. We obtain analytical solutions for the diffusion
process in a generic external potential and for a generic statistics of
residence times, including the non-ergodic regime in which the mean residence
time diverges. We show that these analytical solutions are in agreement with
numerical simulations.


title:
Role of Strain on Electronic and Mechanical Response of Semiconducting
  Transition-Metal Dichalcogenide Monolayers: an ab-initio study

abstract:
  We characterize the electronic structure and elasticity of monolayer
transition-metal dichalcogenides MX2 (M=Mo, W, Sn, Hf and X=S, Se, Te) with 2H
and 1T structures using fully relativistic first principles calculations based
on density functional theory. We focus on the role of strain on the band
structure and band alignment across the series 2D materials. We find that
strain has a significant effect on the band gap; a biaxial strain of 1%
decreases the band gap in the 2H structures, by as a much 0.2 eV in MoS2 and
WS2, while increasing it for the 1T materials. These results indicate that
strain is a powerful avenue to modulate their properties; for example, strain
enables the formation of, otherwise impossible, broken gap heterostructures
within the 2H class. These calculations provide insight and quantitative
information for the rational development of heterostructures based on these
class of materials accounting for the effect of strain.


title: Li-containing scintillating bolometers for low background physics

abstract:
  We present the performances of Li-based compounds used as scintillating
bolometer for rare decay studies such as double-beta decay and direct dark
matter investigations. The compounds are tested in a dilution refrigerator
installed in the underground laboratory of Laboratori Nazionali del Gran Sasso
(Italy). Low temperature scintillating properties are investigated by means of
different radioactive sources, and the radio-purity level for internal
contaminations are estimated for possible employment for next generation
experiments.


title: Bandits and Experts in Metric Spaces

abstract:
  In a multi-armed bandit problem, an online algorithm chooses from a set of
strategies in a sequence of trials so as to maximize the total payoff of the
chosen strategies. While the performance of bandit algorithms with a small
finite strategy set is quite well understood, bandit problems with large
strategy sets are still a topic of very active investigation, motivated by
practical applications such as online auctions and web advertisement. The goal
of such research is to identify broad and natural classes of strategy sets and
payoff functions which enable the design of efficient solutions.
  In this work we study a very general setting for the multi-armed bandit
problem in which the strategies form a metric space, and the payoff function
satisfies a Lipschitz condition with respect to the metric. We refer to this
problem as the "Lipschitz MAB problem". We present a solution for the
multi-armed bandit problem in this setting. That is, for every metric space we
define an isometry invariant which bounds from below the performance of
Lipschitz MAB algorithms for this metric space, and we present an algorithm
which comes arbitrarily close to meeting this bound. Furthermore, our technique
gives even better results for benign payoff functions. We also address the
full-feedback ("best expert") version of the problem, where after every round
the payoffs from all arms are revealed.


title: Alternating knots with unknotting number one

abstract:
  We prove that if an alternating knot has unknotting number one, then there
exists an unknotting crossing in any alternating diagram. This is done by
showing that the obstruction to unknotting number one developed by Greene in
his work on alternating 3-braid knots is sufficient to identify all unknotting
number one alternating knots. As a consequence, we also get a converse to the
Montesinos trick: an alternating knot has unknotting number one if its branched
double cover arises as half-integer surgery on a knot in $S^3$. We also reprove
a characterisation of almost-alternating diagrams of the unknot originally due
to Tsukamoto.


title: Self-dual road to noncommutative gravity with twist: a new analysis

abstract:
  The field equations of noncommutative gravity can be obtained by replacing
all exterior products by twist-deformed exterior products in the action
functional of general relativity, and are here studied by requiring that the
torsion 2-form should vanish, and that the Lorentz-Lie-algebra- valued part of
the full connection 1-form should be self-dual. Other two conditions,
expressing self-duality of a pair 2-forms occurring in the full curvature
2-form, are also imposed. This leads to a systematic solution strategy, here
displayed for the first time, where all parts of the connection 1-form are
first evaluated, hence the full curvature 2-form, and eventually all parts of
the tetrad 1-form, when expanded on the basis of {\gamma}-matrices. By assuming
asymptotic expansions which hold up to first order in the noncommutativity
matrix in the neighbourhood of the vanishing value for noncommutativity, we
find a family of self-dual solutions of the field equations. This is generated
by solving first a inhomogeneous wave equation on 1-forms in a classical curved
spacetime (which is itself self-dual and solves the vacuum Einstein equations),
subject to the Lorenz gauge condition. In particular, when the classical
undeformed geometry is Kasner spacetime, the above scheme is fully computable
out of solutions of the scalar wave equation in such a Kasner model.


title:
Numerical methods with controlled dissipation for small-scale dependent
  shocks

abstract:
  We provide a `user guide' to the literature of the past twenty years
concerning the modeling and approximation of discontinuous solutions to
nonlinear hyperbolic systems that admit small-scale dependent shock waves. We
cover several classes of problems and solutions: nonclassical undercompressive
shocks, hyperbolic systems in nonconservative form, boundary layer problems. We
review the relevant models arising in continuum physics and describe the
numerical methods that have been proposed to capture small-scale dependent
solutions. In agreement with the general well-posedness theory, small-scale
dependent solutions are characterized by a kinetic relation, a family of paths,
or an admissible boundary set. We provide a review of numerical methods (front
tracking schemes, finite difference schemes, finite volume schemes), which, at
the discrete level, reproduce the effect of the physically-meaningful
dissipation mechanisms of interest in the applications. An essential role is
played by the equivalent equation associated with discrete schemes, which is
found to be relevant even for solutions containing shock waves.


title:
Nuclei of Seyfert galaxies and QSOs - Central engine and conditions of
  star formation. Workshop summary and open questions

abstract:
  Observationally established correlations between black hole mass and host
galaxy structural/dynamical properties (like the M_BH - sigma relation) give
support to the idea of an intimate link between the growth of black holes (BHs)
and their host galaxies. Active galactic nuclei represent a poorly understood
phase (or phases) in the life of a galaxy, during which the BH growth is
directly observable. With the advent of wide-field surveys and high angular
resolution instruments, it is now possible to observe the source of energy in
Seyfert galaxies and QSOs, and conduct both statistical and detailed on-object
studies. Combining these two perspectives gives rise to new research questions
and methods. This Workshop, aimed at discussing these questions and gathering
the astronomical community working on AGN, their feeding and feedback
mechanisms, and their relations to the host galaxies. The purpose of this
summary paper is to condense in a few pages some of the ideas and discussion
points that were considered during the Workshop. We would also like to call the
attention to some open questions that are still matter of debate and drive the
research efforts in the field.


title: Fast quantum Monte Carlo on a GPU

abstract:
  We present a scheme for the parallelization of quantum Monte Carlo on
graphical processing units, focusing on bosonic systems and variational Monte
Carlo. We use asynchronous execution schemes with shared memory persistence,
and obtain an excellent acceleration. Comparing with single core execution,
GPU-accelerated code runs over x100 faster. The CUDA code is provided along
with the package that is necessary to execute variational Monte Carlo for a
system representing liquid helium-4. The program was benchmarked on several
models of Nvidia GPU, including Fermi GTX560 and M2090, and the latest Kepler
architecture K20 GPU. Kepler-specific optimization is discussed.


title: Tracy-Widom at high temperature

abstract:
  We investigate the marginal distribution of the bottom eigenvalues of the
stochastic Airy operator when the inverse temperature $\beta$ tends to $0$. We
prove that the minimal eigenvalue, whose fluctuations are governed by the
Tracy-Widom $\beta$ law, converges weakly, when properly centered and scaled,
to the Gumbel distribution. More generally we obtain the convergence in law of
the marginal distribution of any eigenvalue with given index $k$. Those
convergences are obtained after a careful analysis of the explosion times
process of the Riccati diffusion associated to the stochastic Airy operator. We
show that the empirical measure of the explosion times converges weakly to a
Poisson point process using estimates proved in [L. Dumaz and B. Vir\'ag. Ann.
Inst. H. Poincar\'e Probab. Statist. 49, 4, 915-933, (2013)]. We further
compute the empirical eigenvalue density of the stochastic Airy ensemble on the
macroscopic scale when $\beta\to 0$. As an application, we investigate the
maximal eigenvalues statistics of $\beta_N$-ensembles when the repulsion
parameter $\beta_N\to 0$ when $N\to +\infty$. We study the double scaling limit
$N\to +\infty, \beta_N \to 0$ and argue with heuristic and numerical arguments
that the statistics of the marginal distributions can be deduced following the
ideas of [A. Edelman and B. D. Sutton. J. Stat. Phys. 127, 6, 1121-1165 (2007)]
and [J. A. Ram\'irez, B. Rider and B. Vir\'ag. J. Amer. Math. Soc. 24, 919-944
(2011)] from our later study of the stochastic Airy operator.


title: Multiple Time Step Integrators in Ab Initio Molecular Dynamics

abstract:
  Multiple time-scale algorithms exploit the natural separation of time-scales
in chemical systems to greatly accelerate the efficiency of molecular dynamics
simulations. Although the utility of these methods in systems where the
interactions are described by empirical potentials is now well established,
their application to ab initio molecular dynamics calculations has been limited
by difficulties associated with splitting the ab initio potential into fast and
slowly varying components. Here we show that such a timescale separation is
possible using two different schemes: one based on fragment decomposition and
the other on range separation of the Coulomb operator in the electronic
Hamiltonian. We demonstrate for both water clusters and a solvated hydroxide
ion that multiple time-scale molecular dynamics allows for outer time steps of
2.5 fs, which are as large as those obtained when such schemes are applied to
empirical potentials, while still allowing for bonds to be broken and reformed
throughout the dynamics. This permits computational speedups of up to 4.4x,
compared to standard Born-Oppenheimer ab initio molecular dynamics with a 0.5
fs time step, while maintaining the same energy conservation and accuracy.


title:
Species Fractionation in Atomic Chains from Mechanically Stretched
  Alloys

abstract:
  Bettini et al. [Nature Nanotech 1, 182 (2006)] reported the first
experimental realization of linear atomic chains (LACs) composed of different
atoms (Au and Ag). Different contents of Au and Ag were observed in the chains
from what found in the bulk alloys, which rises the question of what is the
wire composition if in equilibrium with a bulk alloy. In this work we address
the thermodynamic driving force for species fractionation in LACs under
tension, and we present density-functional theory results for Ag-Au chain
alloys. A pronounced stabilization of wires with an alternating Ag-Au sequence
is observed, which could be behind the experimentally observed Au enrichment in
LACs from alloys of high Ag content.


title:
An Ontology Model for Organizing Information Resources Sharing on
  Personal Web

abstract:
  Retrieve information resources made by the machine processing may refer to
multiple sources. A personal web as part of information resources in the
Internet requires a feature that can be understood by computer machines.
Therefore, in this paper an ontology semantic web approach is used to map the
resources in a meaningful scheme. In the design of concept, resources on the
web are viewed as documents that have some property and ownership. Domain
interest or web scope is used to describe a classification of resources that
navigate into relevant documents. If instances are completed to the concept,
then the ontology file can be loaded and shared as annotation on personal web.
This allows computer machine to query multiple ontology from different personal
webs that use it.


title:
Using neural networks to estimate redshift distributions. An application
  to CFHTLenS

abstract:
  We present a novel way of using neural networks (NN) to estimate the redshift
distribution of a galaxy sample. We are able to obtain a probability density
function (PDF) for each galaxy using a classification neural network. The
method is applied to 58714 galaxies in CFHTLenS that have spectroscopic
redshifts from DEEP2, VVDS and VIPERS. Using this data we show that the stacked
PDF's give an excellent representation of the true $N(z)$ using information
from 5, 4 or 3 photometric bands. We show that the fractional error due to
using N(z_(phot)) instead of N(z_(truth)) is <=1 on the lensing power spectrum
P_(kappa) in several tomographic bins. Further we investigate how well this
method performs when few training samples are available and show that in this
regime the neural network slightly overestimates the N(z) at high z. Finally
the case where the training sample is not representative of the full data set
is investigated. An IPython notebook accompanying this paper is made available
here: https://bitbucket.org/christopher_bonnett/nn_notebook


title:
Stability estimate and the Aharonov-Bohm effect for the Klein-Gordon
  equation with time-dependent vector potentials

abstract:
  We consider the relativistic Schr\"odinger (Gordon-Klein) equation with a
time dependent vector and a scalar potential on a bounded cylindrical domain.
Using a standard Geometric Optics Ansatz, we establish a logarithmic stability
estimate for the recovery of the vector potentials. We also study the recovery
of the potentials in the presence of obstacles. It is shown that under some
geometric restrictions, the recovery of the potentials is possible up to a
gauge transform.


title: On incorporating post-Newtonian effects in N-body dynamics

abstract:
  The increasing role of general relativity in the dynamics of stellar systems
with central massive black holes and in the evolution of hierarchical triple
systems inspires a close examination of how post-Newtonian effects are
incorporated into N-body dynamics. The majority of approaches incorporate
relativity by adding to the Newtonian N-body equations the standard two-body
post-Newtonian terms for a given star around the black hole or for the close
binary in a triple system. We argue that, for calculating the evolution of such
systems over timescales comparable to the relativistic pericenter advance
timescale, it is essential to include "cross terms" in the equations of motion.
These are post-Newtonian terms that represent a coupling between the potential
of the central black hole and the potential due to other stars in the system.
For hierarchical triple systems, these are couplings between the potential of
the inner binary and that of the distant third body. Over pericenter precession
timescales, the effects of such terms can actually be "boosted" to amplitudes
of Newtonian order. We write down the post-Newtonian N-body equations of motion
including a central black hole in a truncated form that includes all the
relevant cross terms, in a format ready to use for numerical implementation. We
do the same for hierarchical triple systems, and illustrate explicitly the
effects of cross terms on the orbit-averaged equations of evolution for the
orbit elements of the inner binary for the special case where the third body is
on a circular orbit. We also describe the inspiration for this investigation:
the motion of a test body about a central body with a Newtonian quadrupole
moment, including the relativistic pericenter advance, whose correct solution
for the conserved total Newtonian energy requires including PN cross terms
between the mass monopole and quadrupole potentials.


title:
A Technique for Computing Dense Granular Compressible Flows with Shock
  Waves

abstract:
  A numerical procedure was developed for solving equations for compressible
granular multiphase flows in which the particle volume fraction can range
dynamically from very dilute to very dense. The procedure uses a
low-dissipation and high-order numerical method that can describe shocks and
incorporates a particulate model based on kinetic theory. The algorithm
separates edges of a computational cell into gas and solid sections where gas-
and granular-phase Riemann problems are solved independently. Solutions from
these individual Riemann problems are combined to assemble the fully coupled
convective fluxes and nonconservative terms for both phases. The technique
converges under grid refinement even with very high volume fraction granular
interfaces. The method can advect sharp granular material interfaces that
coincide with multi-species gaseous contact surfaces without violating the
pressure nondisturbing condition. The procedure also reproduces known features
from multiphase shock tube problems, granular shocks, transmission angles of
compaction waves, and shock wave and dust-layer interactions. This approach is
relatively straightforward to use in an existing code based on Godunov's method
and can be constructed from standard compressible solvers for the gas-phase and
a modified AUSM$^+$-up scheme for the particle phase.


title:
Modeling the nonlinear clustering in modified gravity models I: A
  fitting formula for matter power spectrum of f(R) gravity

abstract:
  Based on a suite of N-body simulations of the Hu-Sawicki model of f(R)
gravity with different sets of model and cosmological parameters, we develop a
new fitting formula with a numeric code, MGHalofit, to calculate the nonlinear
matter power spectrum P(k) for the Hu-Sawicki model. We compare the MGHalofit
predictions at various redshifts (z<=1) to the f(R) simulations and find that
the accuracy on P(k) is 6% at k<1 h/Mpc and 12% at 1<k<10 h/Mpc respectively.
Based on a sensitivity study of an ongoing and a future spectroscopic survey,
we estimate the detectability of a signal of modified gravity described by the
Hu-Sawicki model using the power spectrum up to quasi-nonlinear scales.
MGHalofit is publicly available at
http://icosmology.info/website/MGHalofit.html.


title: Halo modelling in chameleon theories

abstract:
  We analyse modelling techniques for the large-scale structure formed in
scalar-tensor theories of constant Brans-Dicke parameter which match the
concordance model background expansion history and produce a chameleon
suppression of the gravitational modification in high-density regions. Thereby,
we use a mass and environment dependent chameleon spherical collapse model, the
Sheth-Tormen halo mass function and linear halo bias, the Navarro-Frenk-White
halo density profile, and the halo model. Furthermore, using the spherical
collapse model, we extrapolate a chameleon mass-concentration scaling relation
from a LCDM prescription calibrated to N-body simulations. We also provide
constraints on the model parameters to ensure viability on local scales. We
test our description of the halo mass function and nonlinear matter power
spectrum against the respective observables extracted from large-volume and
high-resolution N-body simulations in the limiting case of f(R) gravity,
corresponding to a vanishing Brans-Dicke parameter. We find good agreement
between the two; the halo model provides a good qualitative description of the
shape of the relative enhancement of the f(R) matter power spectrum with
respect to LCDM caused by the extra attractive gravitational force but fails to
recover the correct amplitude. Introducing an effective linear power spectrum
in the computation of the two-halo term to account for an underestimation of
the chameleon suppression at intermediate scales in our approach, we accurately
reproduce the measurements from the N-body simulations.


title: A property of the inverse of a subspace of a finite field

abstract:
  We prove a geometric property of the set A^{-1} of inverses of the nonzero
elements of an F_q-subspace A of a finite field involving the size of its
intersection with two-dimensional F_q-subspaces. We give some applications,
including a new upper bound on the size of the intersection of A^{-1} and B
when A and B are F_q-subspaces of different dimension of a finite field,
satisfying a suitable natural assumption.


title: 5D partition functions, q-Virasoro systems and integrable spin-chains

abstract:
  We analyze N = 1 theories on S5 and S4 x S1, showing how their partition
functions can be written in terms of a set of fundamental 5d holomorphic
blocks. We demonstrate that, when the 5d mass parameters are analytically
continued to suitable values, the S5 and S4 x S1 partition functions degenerate
to those for S3 and S2 x S1. We explain this mechanism via the recently
proposed correspondence between 5d partition functions and correlators with
underlying q-Virasoro symmetry. From the q-Virasoro 3-point functions, we
axiomatically derive a set of associated reflection coefficients, and show they
can be geometrically interpreted in terms of Harish-Chandra c-functions for
quantum symmetric spaces. We then link these particular c-functions to the
types appearing in the Jost functions encoding the asymptotics of the
scattering in integrable spin chains, obtained taking different limits of the
XYZ model to XXZ-type.


title:
Heat transfers in a double-skin roof ventilated by natural convection in
  summer time

abstract:
  The double-skin roofs investigated in this paper are formed by adding a
metallic screen on an existing sheet metal roof. The system enhances passive
cooling of dwellings and can help diminishing power costs for air conditioning
in summer or in tropical and arid countries. In this work, radiation,
convection and conduction heat transfers are investigated. Depending on its
surface properties, the screen reflects a large amount of oncoming solar
radiation. Natural convection in the channel underneath drives off the residual
heat. The bi-dimensional numerical simulation of the heat transfers through the
double skin reveals the most important parameters for the system's efficiency.
They are, by order of importance, the sheet metal surface emissivity, the
screen internal and external surface emissivity, the insulation thickness and
the inclination angle for a channel width over 6 cm. The influence of those
parameters on Rayleigh and Nusselt numbers is also investigated. Temperature
and air velocity profiles on several channel cross-sections are plotted and
discussed.


title:
One-Loop Single-Real-Emission Contributions to $pp\to H + X$ at
  Next-to-Next-to-Next-to-Leading Order

abstract:
  I compute the contributions of the one-loop single-real-emission amplitudes,
$gg\to H g$, $qg\to H q$, etc., to inclusive Higgs boson production through
next-to-next-to-next-to-leading order (N^3LO) in the strong coupling
$\alpha_s$. The next-to-leading (NLO) and next-to-next-to-leading order (NNLO)
terms are computed in closed form, in terms of $\Gamma$-functions and the
hypergeometric functions ${}_{2}F_{1}$ and ${}_{3}F_{2}$. I compute the \nnnlo\
terms as Laurent expansions in the dimensional regularization parameter through
order $(\epsilon^{1})$. To obtain the \nnnlo\ terms, I perform an extended
threshold expansion of the phase space integrals and map the resulting
coefficients onto a basis of harmonic polylogarithms.


title: System analysis of Force Feedback Microscopy

abstract:
  It was shown recently that the Force Feedback Microscope can avoid the
jump-to-contact in Atomic force Microscopy even when the cantilevers used are
very soft, thus increasing force resolution. In this letter, we explore
theoretical aspects of the associated real time control of the tip position. We
take into account lever parameters such as the lever characteristics in its
environment, spring constant, mass, dissipation coefficient and the operating
conditions such as controller gains, and interaction force. We show how the
controller parameters are determined so that the FFM functions at its best and
estimate the bandwidth of the system under these conditions.


title: DNA confined in a two-dimensional strip geometry

abstract:
  Semiflexible polymers characterized by the contour length $L$ and persistent
length $\ell_p$ confined in a spatial region $D$ have been described as a
series of ``{\em spherical blobs}'' and ``{\em deflecting lines}'' by de Gennes
and Odjik for $\ell_p < D$ and $\ell_p \gg D$ respectively. Recently new
intermediate regimes ({\em extended de Gennes} and {\em Gauss-de Gennes}) have
been investigated by Tree {\em et al.} [Phys. Rev. Lett. {\bf 110}, 208103
(2013)]. In this letter we derive scaling relations to characterize these
transitions in terms of universal scaled fluctuations in $d$-dimension as a
function of $L,\ell_p$, and $D$, and show that the Gauss-de Gennes regime is
absent and extended de Gennes regime is vanishingly small for polymers confined
in a 2D strip. We validate our claim by extensive Brownian dynamics (BD)
simulation which also reveals that the prefactor $A$ used to describe the chain
extension in the Odjik limit is independent of physical dimension $d$ and is
the same as previously found by Yang {\em et al.}[Y. Yang, T. W. Burkhardt, G.
Gompper, Phys. Rev. E {\bf 76}, 011804 (2007)]. Our studies are relevant for
optical maps of DNA stretched inside a nano-strip.