title:
Detecting multiple periodicities in observational data with the
  multi-frequency periodogram. I. Analytic assessment of the statistical
  significance

abstract:
  We consider the "multi-frequency" periodogram, in which the putative signal
is modelled as a sum of two or more sinusoidal harmonics with idependent
frequencies. It is useful in the cases when the data may contain several
periodic components, especially when their interaction with each other and with
the data sampling patterns might produce misleading results.
  Although the multi-frequency statistic itself was already constructed, e.g.
by G. Foster in his CLEANest algorithm, its probabilistic properties (the
detection significance levels) are still poorly known and much of what is
deemed known is unrigourous. These detection levels are nonetheless important
for the data analysis. We argue that to prove the simultaneous existence of all
$n$ components revealed in a multi-periodic variation, it is mandatory to apply
at least $2^n-1$ significance tests, among which the most involves various
multi-frequency statistics, and only $n$ tests are single-frequency ones.
  The main result of the paper is an analytic estimation of the statistical
significance of the frequency tuples that the multi-frequency periodogram can
reveal. Using the theory of extreme values of random fields (the generalized
Rice method), we find a handy approximation to the relevant false alarm
probability. For the double-frequency periodogram this approximation is given
by an elementary formula $\frac{\pi}{16} W^2 e^{-z} z^2$, where $W$ stands for
a normalized width of the settled frequency range, and $z$ is the observed
periodogram maximum. We carried out intensive Monte Carlo simulations to show
that the practical quality of this approximation is satisfactory. A similar
analytic expression for the general multi-frequency periodogram is also given
in the paper, though with a smaller amount of numerical verification.


title: Localizability of Wireless Sensor Networks: Beyond Wheel Extension

abstract:
  A network is called localizable if the positions of all the nodes of the
network can be computed uniquely. If a network is localizable and embedded in
plane with generic configuration, the positions of the nodes may be computed
uniquely in finite time. Therefore, identifying localizable networks is an
important function. If the complete information about the network is available
at a single place, localizability can be tested in polynomial time. In a
distributed environment, networks with trilateration orderings (popular in real
applications) and wheel extensions (a specific class of localizable networks)
embedded in plane can be identified by existing techniques. We propose a
distributed technique which efficiently identifies a larger class of
localizable networks. This class covers both trilateration and wheel
extensions. In reality, exact distance is almost impossible or costly. The
proposed algorithm based only on connectivity information. It requires no
distance information.


title: Optimal Payoffs under State-dependent Preferences

abstract:
  Most decision theories, including expected utility theory, rank dependent
utility theory and cumulative prospect theory, assume that investors are only
interested in the distribution of returns and not in the states of the economy
in which income is received. Optimal payoffs have their lowest outcomes when
the economy is in a downturn, and this feature is often at odds with the needs
of many investors. We introduce a framework for portfolio selection within
which state-dependent preferences can be accommodated. Specifically, we assume
that investors care about the distribution of final wealth and its interaction
with some benchmark. In this context, we are able to characterize optimal
payoffs in explicit form. Furthermore, we extend the classical expected utility
optimization problem of Merton to the state-dependent situation. Some
applications in security design are discussed in detail and we also solve some
stochastic extensions of the target probability optimization problem.


title:
Exchange parameters and adiabatic magnon energies from spin-spiral
  calculations

abstract:
  We present a method of extracting the exchange parameters of the classical
Heisenberg model from first-principles calculations of spin-spiral total
energies based on density functional theory. The exchange parameters of the
transition-metal monoxides MnO and NiO are calculated and used to estimate
magnetic properties such as transition temperatures and magnon energies.
Furthermore we show how to relate the magnon energies directly to differences
in spin-spiral total energies for systems containing an arbitrary number of
magnetic sublattices. This provides a comparison between magnon energies using
a finite number of exchange parameters and the infinite limit.


title: Coherently opening a high-Q cavity

abstract:
  We propose a general framework to effectively `open' a high-Q resonator, that
is, to release the quantum state initially prepared in it in the form of a
traveling electromagnetic wave. This is achieved by employing a mediating mode
that scatters coherently the radiation from the resonator into a
one-dimensional continuum of modes such as a waveguide. The same mechanism may
be used to `feed' a desired quantum field to an initially empty cavity.
Switching between an `open' and `closed' resonator may then be obtained by
controlling either the detuning of the scatterer or the amount of time it
spends in the resonator. First, we introduce the model in its general form,
identifying (i) the traveling mode that optimally retains the full quantum
information of the resonator field and (ii) a suitable figure of merit that we
study analytically in terms of the system parameters. Then, we discuss two
feasible implementations based on ensembles of two-level atoms interacting with
cavity fields. In addition, we discuss how to integrate traditional cavity QED
in our proposal using three-level atoms.


title: Limits on Lorentz violation in neutral-Kaon decay

abstract:
  The KLOE collaboration recently reported bounds on the directional dependence
of the lifetime of the short-lived neutral kaon K_S with respect to the cosmic
microwave background dipole anisotropy. We interpret their results in a general
framework developed to probe Lorentz violation in the weak interaction. In this
approach a Lorentz-violating tensor \chi_{\mu\nu} is added to the standard
propagator of the W boson. We derive the K_S decay rate in a naive tree-level
model and calculate the asymmetry for the lifetime. By using the KLOE data the
real vector part of \chi_{\mu\nu} is found to be smaller than 10^-2. We briefly
discuss the theoretical challenges concerning nonleptonic decays.


title:
Using Chip Multithreading to Speed Up Scenario-Based Design Space
  Exploration

abstract:
  To cope with the complex embedded system design, early design space
exploration (DSE) is used to make design decisions early in the design phase.
For early DSE it is crucial that the running time of the exploration is as
small as possible. In this paper, we describe both the porting of our
scenario-based DSE to the SPARC T3-4 server and the analysis of its performance
behavior.


title:
Nuclear stopping for heavy-ion induced reactions in the Fermi Energy
  range : from 1-Body to 2-Body dissipation

abstract:
  We address the stopping in heavy-ion induced reactions around the Fermi
energy using central collisions recorded with \emph{INDRA} $4\pi$ array. The
stopping is minimal around the Fermi energy and corresponds to the
disappearance of the Mean-Field effects and the appearance of nucleon-nucleon
elastic collisions. This phenomenon is attributed to a change in the
dissipation regime going from 1-body (Mean-Field) dissipation at low incident
energy to 2- body (nucleonic collisions) above the Fermi energy. A connection
to the in-medium transport properties of nuclear matter is proposed and
comprehensive values of the nucleon mean free path $\lambda_{NN}$ and the
nucleon-nucleon cross section are extracted.


title:
Convergence to equilibrium for positive solutions of some
  mutation-selection model

abstract:
  In this paper we are interested in the long time behaviour of the positive
solutions of the mutation selection model with Neumann Boundary condition: $$
\frac{\partial
u(x,t)}{dt}=u\left[r(x)-\int_{\O}K(x,y)|u|^{p}(y)\,dy\right]+\nabla\cdot\left(A(x)\nabla
u(x)\right),\qquad \text{in}\quad \R^+\times\O$$ where $\O\subset \R^N$ is a
bounded smooth domain, $k(.,.) \in C(\bar \O \times C(\bar\O), \R), p\ge 1$ and
$A(x)$ is a smooth elliptic matrix. In a blind competition situation, i.e
$K(x,y)=k(y)$, we show the existence of a unique positive steady state which is
positively globally stable. That is, the positive steady state attracts all the
possible trajectories initiated from any non negative initial datum. When $K$
is a general positive kernel, we also present a necessary and sufficient
condition for the existence of a positive steady states. We prove also some
stability result on the dynamic of the equation when the competition kernel $K$
is of the form $K(x,y)=k_0(y)+\eps k_1(x,y)$. That is, we prove that for
sufficiently small $\eps$ there exists a unique steady state, which in addition
is positively asymptotically stable. The proofs of the global stability of the
steady state essentially rely on non-linear relative entropy identities and an
orthogonal decomposition. These identities combined with the decomposition
provide us some a priori estimates and differential inequalities essential to
characterise the asymptotic behaviour of the solutions.


title: Search for hidden turbulent gas through interstellar scintillation

abstract:
  Stars twinkle because their light propagates through the atmosphere. The same
phenomenon is expected when the light of remote stars crosses a Galactic - disk
or halo - refractive medium such as a molecular cloud. We present the promising
results of a test performed with the ESO-NTT and the perspectives of detection.


title:
Tetrahedron equation and quantum R matrices for infinite dimensional
  modules of U_q(A^{(1)}_1) and U_q(A^{(2)}_2)

abstract:
  From the q-oscillator solution to the tetrahedron equation associated with a
quantized coordinate ring, we construct solutions to the Yang-Baxter equation
by applying a reduction procedure formulated earlier by S. Sergeev and the
first author. The results are identified with the quantum R matrices for the
infinite dimensional modules of U_q(A^{(1)}_1) and U_q(A^{(2)}_2) corresponding
to an affinization of Verma modules of their subalgebras isomorphic to
U_q(sl_2) and U_{q^4}(sl_2).


title: Remarks on Wilmshurst's theorem

abstract:
  We demonstrate counterexamples to Wilmshurst's conjecture on the valence of
harmonic polynomials in the plane, and we conjecture a bound that is linear in
the analytic degree for each fixed anti-analytic degree. Then we initiate a
discussion of Wilmshurt's theorem in more than two dimensions, showing that if
the zero set of a polynomial harmonic field is bounded then it must have
codimension at least two. Examples are provided to show that this conclusion
cannot be improved.


title:
Self-stabilizing TDMA Algorithms for Wireless Ad-hoc Networks without
  External Reference

abstract:
  Time division multiple access (TDMA) is a method for sharing communication
media. In wireless communications, TDMA algorithms often divide the radio time
into timeslots of uniform size, $\xi$, and then combine them into frames of
uniform size, $\tau$. We consider TDMA algorithms that allocate at least one
timeslot in every frame to every node. Given a maximal node degree, $\delta$,
and no access to external references for collision detection, time or position,
we consider the problem of collision-free self-stabilizing TDMA algorithms that
use constant frame size.
  We demonstrate that this problem has no solution when the frame size is $\tau
< \max\{2\delta,\chi_2\}$, where $\chi_2$ is the chromatic number for
distance-$2$ vertex coloring. As a complement to this lower bound, we focus on
proving the existence of collision-free self-stabilizing TDMA algorithms that
use constant frame size of $\tau$. We consider basic settings (no hardware
support for collision detection and no prior clock synchronization), and the
collision of concurrent transmissions from transmitters that are at most two
hops apart. In the context of self-stabilizing systems that have no external
reference, we are the first to study this problem (to the best of our
knowledge), and use simulations to show convergence even with computation time
uncertainties.


title:
Dense baryonic matter in conformally-compensated hidden local symmetry:
  Vector manifestation and chiral symmetry restoration

abstract:
  We find that, when the dilaton is implemented as a (pseudo-)Nambu-Goldstone
boson using a conformal compensator or "conformon" in a hidden gauge symmetric
Lagrangian written to $O(p^4)$ from which baryons arise as solitons, namely,
skyrmions, the vector manifestation and chiral symmetry restoration at high
density predicted in hidden local symmetry theory --- which is consistent with
Brown-Rho scaling --- are lost or sent to infinite density. It is shown that
they can be restored if in medium the behavior of the $\omega$ field is taken
to deviate from that of the $\rho$ meson in such a way that the flavor $U(2)$
symmetry is strongly broken at increasing density. The hitherto unexposed
crucial role of the $\omega$ meson in the structure of elementary baryon and
multibaryon systems is uncovered in this work. In the state of half-skyrmions
to which the skyrmions transform at a density $n_{1/2}^{} \gtrsim n_0^{}$
(where $n_0^{}$ is the normal nuclear matter density), characterized by the
vanishing (space averaged) quark condensate but nonzero pion decay constant,
the nucleon mass remains more or less constant at a value $\gtrsim$ 60 \% of
the vacuum value indicating a large component of the nucleon mass that is not
associated with the spontaneous breaking of chiral symmetry. We discuss its
connection to the chiral-invariant mass $m_0^{}$ that figures in the
parity-doublet baryon model.


abstract:
  In this paper certain Tur\'an type inequalities for some Lommel functions of
the first kind are deduced. The key tools in our proofs are the infinite
product representation for these Lommel functions of the first kind, a
classical result of G. P\'olya on the zeros of some particular entire
functions, and the connection of these Lommel functions with the so-called
Laguerre-P\'olya class of entire functions. Moreover, it is shown that in some
cases J. Steinig's results on the sign of Lommel functions of the first kind
combined with the so-called monotone form of l'Hospital's rule can be used in
the proof of the corresponding Tur\'an type inequalities.


title: Broad N2H+ emission towards the protostellar shock L1157-B1

abstract:
  We present the first detection of N2H+ towards a low-mass protostellar
outflow, namely the L1157-B1 shock, at about 0.1 pc from the protostellar
cocoon. The detection was obtained with the IRAM 30-m antenna. We observed
emission at 93 GHz due to the J = 1-0 hyperfine lines. The analysis of the
emission coupled with the HIFI CHESS multiline CO observations leads to the
conclusion that the observed N2H+(1-0) line originates from the dense (> 10^5
cm-3) gas associated with the large (20-25 arcsec) cavities opened by the
protostellar wind. We find a N2H+ column density of few 10^12 cm-2
corresponding to an abundance of (2-8) 10^-9. The N2H+ abundance can be matched
by a model of quiescent gas evolved for more than 10^4 yr, i.e. for more than
the shock kinematical age (about 2000 yr). Modelling of C-shocks confirms that
the abundance of N2H+ is not increased by the passage of the shock. In summary,
N2H+ is a fossil record of the pre-shock gas, formed when the density of the
gas was around 10^4 cm-3, and then further compressed and accelerated by the
shock.


title: Topological metastability of textures in biaxial nematics

abstract:
  We consider textures of biaxial nematics confined between two parallel
plates. The boundary conformations at the bordering plates are supposed to be
identical, the gradients of the order parameter being generally nonzero. We
claim that for any texture (including stable uniform order parameter alignment)
there exists its counterpart texture which is also a minimum of the gradient
elastic energy. Our arguments are based on the topological analysis of the
conformation of the order parameter.


title:
The role of mutation rate variation and genetic diversity in the
  architecture of human disease

abstract:
  We have investigated the role that the mutation rate and the structure of
genetic variation at a locus play in determining whether a gene is involved in
disease. We predict that the mutation rate and its genetic diversity should be
higher in genes associated with disease, unless all genes that could cause
disease have already been identified. Consistent with our predictions we find
that genes associated with Mendelian and complex disease are substantially
longer than non-disease genes. However, we find that both Mendelian and complex
disease genes are found in regions of the genome with relatively low mutation
rates, as inferred from intron divergence between humans and chimpanzees.
Complex disease gene are predicted to have higher rates of non-synonymous
mutation than non-disease genes, but the opposite pattern is found in Mendelian
disease genes. Finally, we find that disease genes are in regions of
significantly elevated genetic diversity, even when variation in the rate of
mutation is controlled for. The effect is small nevertheless. Our results
suggest that variation in the genic mutation rate and the genetic architecture
of the locus play a minor role in determining whether a gene is associated with
disease.


title:
Nonparametric Decentralized Sequential Detection via Universal Source
  Coding

abstract:
  We consider nonparametric or universal sequential hypothesis testing problem
when the distribution under the null hypothesis is fully known but the
alternate hypothesis corresponds to some other unknown distribution. These
algorithms are primarily motivated from spectrum sensing in Cognitive Radios
and intruder detection in wireless sensor networks. We use easily implementable
universal lossless source codes to propose simple algorithms for such a setup.
The algorithms are first proposed for discrete alphabet. Their performance and
asymptotic properties are studied theoretically. Later these are extended to
continuous alphabets. Their performance with two well known universal source
codes, Lempel-Ziv code and Krichevsky-Trofimov estimator with Arithmetic
Encoder are compared. These algorithms are also compared with the tests using
various other nonparametric estimators. Finally a decentralized version
utilizing spatial diversity is also proposed. Its performance is analysed and
asymptotic properties are proved.


title:
Accurate lubrication corrections for spherical and non-spherical
  particles in discretized fluid simulations

abstract:
  Discretized fluid solvers coupled to a Newtonian dynamics method are a
popular tool to study suspension flow. As any simulation technique with finite
resolution, the lattice Boltzmann method, when coupled to discrete particles
using the momentum exchange method, resolves the diverging lubrication
interactions between surfaces near contact only insufficiently. For spheres, it
is common practice to account for surface-normal lubrication forces by means of
an explicit correction term. A method that additionally covers all further
singular interactions for spheres is present in the literature as well as a
link-based approach that allows for more general shapes but does not capture
non-normal interactions correctly. In this paper, lattice-independent
lubrication corrections for aspherical particles are outlined, taking into
account all leading divergent interaction terms. An efficient implementation
for arbitrary spheroids is presented and compared to purely normal and
link-based models. Good consistency with Stokesian dynamics simulations of
spheres is found. The non-normal interactions affect the viscosity of
suspensions of spheres at volume fractions \Phi >= 0.3 but already at \Phi >=
0.2 for spheroids. Regarding shear-induced diffusion of spheres, a distinct
effect is found at 0.1 <= \Phi <= 0.5 and even increasing the resolution of the
radius to 8 lattice units is no substitute for an accurate modeling of
non-normal interactions.


title:
Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies:
  Supplemental Material

abstract:
  This is the Supplemental Material to Kormendy and Ho 2013, ARAA, 51, 511
(arXiv:1304.7762). Section S1 summarizes indirect methods that are used to
estimate black hole (BH) masses for galaxies with active nuclei (AGNs). Section
S2 lists the observational criteria that are used to classify classical and
pseudo bulges. The (pseudo)bulge classifications used in the main paper are not
based on physical interpretation; rather, they are based on these observational
criteria. Section S3 supplements the BH database in Section 5 of the main paper
and Section S4 here. It discusses corrections to galaxy and BH parameters, most
importantly to 2MASS K-band apparent magnitudes. It presents evidence that
corrections are needed because 2MASS misses light at large radii when the
images of galaxies subtend large angles on the sky or have shallow outer
brightness gradients. Section S4 reproduces essentially verbatim the first part
of Section 5 in the main paper, the BH database. It includes the list of BH and
host-galaxy properties (Tables 2 and 3). Its most important purpose is to
provide all of the notes on individual objects.


title: Probing the flavor violating scalar top quark signal at the LHC

abstract:
  The Large Hadron Collider(LHC) has completed its run at 8 TeV with the
experiments ATLAS and CMS having collected about 25 $\rm fb^{-1}$ of data each.
Discovery of a light Higgs boson, coupled with lack of evidence for
supersymmetry at the LHC so far, has motivated studies of supersymmetry in the
context of naturalness with the principal focus being the third generation
squarks. In this work, we analyze the prospects of the flavor violating decay
mode $\rm \tilde{t}_1\to c\chi_{1}^{0}$ at 8 and 13 TeV center of mass energy
at the LHC. This channel is also relevant in the dark matter context for the
stop-coannihilation scenario, where the relic density depends on the mass
difference between the lighter stop quark ($\tilde{t}_1$) and the lightest
neutralino($\chi_{1}^{0}$) states. This channel is extremely challenging to
probe, specially for situations when the mass difference between the lighter
stop quark and the lightest neutralino is small. Using certain kinematical
properties of signal events we find that the level of backgrounds can be
reduced substantially. We find that the prospect for this channel is limited
due to the low production cross section for top squarks and limited luminosity
at 8 TeV, but at the 13 TeV LHC with 100 $fb^{-1}$ luminosity, it is possible
to probe top squarks with masses up to $\sim$ 450 GeV. We also discuss how the
sensitivity could be significantly improved by tagging charm jets.


title: Instanton effects and quantum spectral curves

abstract:
  We study a spectral problem associated to the quantization of a spectral
curve arising in local mirror symmetry. The perturbative WKB quantization
condition is determined by the quantum periods, or equivalently by the refined
topological string in the Nekrasov-Shatashvili (NS) limit. We show that the
information encoded in the quantum periods is radically insufficient to
determine the spectrum: there is an infinite series of instanton corrections,
which are non-perturbative in \hbar, and lead to an exact WKB quantization
condition. Moreover, we conjecture the precise form of the instanton
corrections: they are determined by the standard or un-refined topological
string free energy, and we test our conjecture successfully against numerical
calculations of the spectrum. This suggests that the non-perturbative sector of
the NS refined topological string contains information about the standard
topological string. As an application of the WKB quantization condition, we
explain some recent observations relating membrane instanton corrections in
ABJM theory to the refined topological string.


title: Higgs Boson and Top-Quark Masses and Parity-Symmetry Restoration

abstract:
  The recent ATLAS and CMS experiments show the first observations of a new
particle in the search for the Standard Model Higgs boson at the LHC. We
revisit the scenario that high-dimensional operators of fermions must be
present due to the theoretical inconsistency of the fundamental cutoff (quantum
gravity) with the parity-violating gauge symmetry of the Standard Model.
Studying the four-fermion interaction of the third quark family, we show that
at an intermediate energy threshold E\approx 4.27 TeV for the four-fermion
coupling being larger than a critical value, the spontaneous symmetry-breaking
phase transits to the strong-coupling symmetric phase where composite Dirac
fermions form fully preserving the chiral gauge symmetry of the Standard Model
and the parity-symmetry is restored. Under this circumstance, we perform the
standard analysis of renormalization-group equations of the Standard Model in
the spontaneous symmetry-breaking phase. As a result, the Higgs boson mass
m_H\approx 126.7 GeV and top-quark mass m_t\approx 172.7 GeV are obtained
without drastically fine-tuning the four-fermion coupling.


title: A New Algorithm of Speckle Filtering using Stochastic Distances

abstract:
  This paper presents a new approach for filter design based on stochastic
distances and tests between distributions. A window is defined around each
pixel, overlapping samples are compared and only those which pass a
goodness-of-fit test are used to compute the filtered value. The technique is
applied to intensity SAR data with homogeneous regions using the Gamma model.
The proposal is compared with the Lee's filter using a protocol based on Monte
Carlo. Among the criteria used to quantify the quality of filters, we employ
the equivalent number of looks, line and edge preservation. Moreover, we also
assessed the filters by the Universal Image Quality Index and the Pearson's
correlation on edges regions.

categories: cs.IT cs.CV cs.GR math.IT stat.AP stat.ML


title:
Modeling the interaction of an arbitrary light field with a diffraction
  grating by the Monte Carlo method

abstract:
  A high-accuracy solution of the diffraction problem has become necessary for
the treatment of certain special questions of statistical physics. This article
reports the creation of a computer program that serves as an instrumental
method of calculating the parameters of diffraction phenomena when complex
optical systems are being theoretically investigated. The program solves the
diffraction problem by a rigorous method based on Maxwell"s equations under
specified boundary conditions. An arbitrary for instance, diffuse configuration
of the initial light field is allowed. Reflective gratings with a linear or
crossed sinusoidal profile of the surface micro relief are considered as the
diffraction optical elements. The characteristics of the self-consistent total
light field can be calculated when several diffraction elements are present in
the system.


title:
A novel black hole mimicker: a boson star and a global monopole
  nonminimally coupled to gravity

abstract:
  A field-theoretic model for a highly compact object that mimicks a black hole
is found for the gravitationally interacting system of a boson star and a
global monopole which are nonminimally coupled to gravity. According to the
strength of the nonlinear gravitational effects and the gravitational
backreaction, three distinct coupling regimes are featured: weak, mild and
strong. In the strong coupling regime we show that a repulsive monopole
stabilizes an attractive boson star and the resulting configuration exhibits
large energy density, large (and negative) principal pressures, large
compactness, large effective potential, large local forces, and yet exhibits no
event horizon. As such a composite system of a boson star and a global monopole
represents a convincing microscopic candidate for a black hole mimicker.


title: CO outflows from high-mass Class 0 protostars in Cygnus-X

abstract:
  As natural consequences of the accretion process, outflows are one of the few
(indirect) tracers of accretion. We used CO(2-1) PdBI observations towards 6
MDCs in Cygnus-X, containing 9 high-mass cores, to investigate what the
accretion process and origin of the material feeding the precursors of
high-mass stars are. We compared our sample to low-mass objects from the
literature and developed simple evolutionary models to reproduce the
observables. We find that 8/9 high-mass cores drive clear individual outflows
as true equivalents of Class 0 protostars in the high-mass regime. The
remaining core has only a tentative outflow detection. It could be amongst the
first examples of a true individual high-mass prestellar core. We find that the
momentum flux of high-mass objects has a linear relation to the envelope mass,
as a scale-up of the relations found for low-mass protostars. This suggests a
fundamental proportionality between accretion rates and mass reservoir,
suggesting identical collapse timescales for all masses. We conclude that if
the pre-collapse evolution is quasi-static, the fragmentation scale (which is
similar for all masses) would limit the size of the initial mass reservoirs,
leading to shorter free-fall times for higher mass stars. However, as we find
identical collapse timescales for all masses, a significant turbulent/magnetic
support is needed to slow down the collapse of the more massive envelopes in a
quasi-static view. With this support still to be discovered, and with
indications of large dynamics in pre-collapse gas for high-mass star formation,
we propose that such an identical collapse timescale implies that the initial
densities, which should set the duration of the collapse, should be similar for
all masses. This suggests that the mass that incorporates massive stars has to
have been accreted in a dynamical way from larger scales than those of low-mass
stars.


title: Phononic Frequency Combs via Nonlinear Resonances

abstract:
  We study the analogue of optical frequency combs in driven nonlinear phononic
systems, and present a new generation mechanism for phononic frequency combs
via nonlinear resonances. The nonlinear resonance refers to the simultaneous
excitation of a set of phonon modes by the external driving, and thereby
generated frequency combs are characterized by an array of equidistant spectral
lines in the spectrum of each nonlinearly excited phonon mode. Frequency combs
via nonlinear resonance of different orders are investigated, and particularly
we reveal the possibility for correlation tailoring in higher order cases. The
investigation contributes to potential applications in various nonlinear
acoustic processes, such as harvesting phonons and generating phonon
entanglements, and can also be generalized to other nonlinear systems.


title: Grain boundary ferromagnetism in vanadium-doped In$_2$O$_3$ thin films

abstract:
  Room temperature ferromagnetism was observed in In$_2$O$_3 thin films doped
with 5 at.% vanadium, prepared by pulsed laser deposition at substrate
temperatures ranging from 300 to 600 $\,^{\circ}{\rm C}$. X-ray absorption fine
structure measurement indicated that vanadium was substitutionally dissolved in
the In$_2$O$_3$ host lattice, thus excluding the existence of secondary phases
of vanadium compounds. Magnetic measurements based on SQUID magnetometry and
magnetic circular dichroism confirm that the magnetism is at grain boundaries
and also in the grains. The overall magnetization originates from the competing
effects between grains and grain boundaries.


title:
QCD Corrections to Quark (Chromo)Electric Dipole Moments in High-scale
  Supersymmetry

abstract:
  Recent results from the LHC experiments, both for the Higgs mass measurement
and the direct search for supersymmetric (SUSY) particles, might indicate that
the SUSY breaking scale is much higher than the electroweak scale. Although it
is difficult to investigate such a scenario at collider experiments, the
measurement of the hadronic electric dipole moments is one of promising ways to
detect the effects of the SUSY particles. These effects are expressed in terms
of the CP-violating effective operators defined at the SUSY breaking scale,
which involve quarks, gluons, photons, and gluinos. In this paper, we discuss
the QCD corrections to the effective operators in the high-scale SUSY scenario.
To appropriately evaluate the radiative corrections in the presence of large
mass hierarchy among the SUSY particles, we exploit an effective theoretical
approach based on the renormalization-group equations. As a result, it is found
that the low-energy quark electric and chromoelectric dipole moments may differ
from those evaluated in previous works by O(100) % and O(10) %, respectively.


title: Spectral community detection in sparse networks

abstract:
  Spectral methods based on the eigenvectors of matrices are widely used in the
analysis of network data, particularly for community detection and graph
partitioning. Standard methods based on the adjacency matrix and related
matrices, however, break down for very sparse networks, which includes many
networks of practical interest. As a solution to this problem it has been
recently proposed that we focus instead on the spectrum of the non-backtracking
matrix, an alternative matrix representation of a network that shows better
behavior in the sparse limit. Inspired by this suggestion, we here make use of
a relaxation method to derive a spectral community detection algorithm that
works well even in the sparse regime where other methods break down.
Interestingly, however, the matrix at the heart of the method, it turns out, is
not exactly the non-backtracking matrix, but a variant of it with a somewhat
different definition. We study the behavior of this variant matrix for both
artificial and real-world networks and find it to have desirable properties,
especially in the common case of networks with broad degree distributions, for
which it appears to have a better behaved spectrum and eigenvectors than the
original non-backtracking matrix.


title: Iterated icons

abstract:
  We study the totality of categories weakly enriched in a monoidal bicategory
using a notion of enriched icon as 2-cells. We show that when the monoidal
bicategory in question is symmetric then this process can be iterated. We show
that starting from the symmetric monoidal bicategory Cat and performing the
construction twice yields a convenient symmetric monoidal bicategory of
partially strict tricategories. We show that restricting to the doubly
degenerate ones immediately gives the correct bicategory of "2-tuply monoidal
categories" missing from our earlier studies of the Periodic Table. We propose
a generalisation to all k-tuply monoidal n-categories.


title:
A near-infrared census of the multi-component stellar structure of
  early-type dwarf galaxies in the Virgo cluster

abstract:
  The fraction of star-forming to quiescent dwarf galaxies varies from almost
infinity in the field to zero in the centers of rich galaxy clusters. What is
causing this pronounced morphology-density relation? What do quiescent dwarf
galaxies look like when studied in detail, and what conclusions can be drawn
about their formation mechanism? Here we study a nearly magnitude-complete
sample (-19 < M_r < -16 mag) of 121 Virgo cluster early types with deep
near-infrared images from the SMAKCED project. We fit two-dimensional models
with optional inner and outer components, as well as bar and lens components
(in ~15% of the galaxies), to the galaxy images. While a single S\'ersic
function may approximate the overall galaxy structure, it does not entirely
capture the light distribution of two-thirds of our galaxies, for which
multi-component models provide a better fit. This fraction of complex galaxies
shows a strong dependence on luminosity, being larger for brighter objects. We
analyze the global and component-specific photometric scaling relations of
early-type dwarf galaxies and discuss similarities with bright early and late
types. The dwarfs' global galaxy parameters show scaling relations that are
similar to those of bright disk galaxies. The inner components are mostly
fitted with S\'ersic n values close to 1. At a given magnitude they are
systematically larger than the bulges of spirals, suggesting that they are not
ordinary bulges. We argue that the multi-component structures in early-type
dwarfs are mostly a phenomenon inherent to the disks, and may indeed stem from
environmental processing.


title: Splittings of knot groups

abstract:
  Let K be a knot of genus g. If K is fibered, then it is well known that the
knot group pi(K) splits only over a free group of rank 2g. We show that if K is
not fibered, then pi(K) splits over non-free groups of arbitrarily large rank.
Furthermore, if K is not fibered, then pi(K) splits over every free group of
rank at least 2g. However, pi(K) cannot split over a group of rank less than
2g. The last statement is proved using the recent results of Agol,
Przytycki-Wise and Wise.


title: Universal Approximation Using Shuffled Linear Models

abstract:
  This paper proposes a specific type of Local Linear Model, the Shuffled
Linear Model (SLM), that can be used as a universal approximator. Local
operating points are chosen randomly and linear models are used to approximate
a function or system around these points. The model can also be interpreted as
an extension to Extreme Learning Machines with Radial Basis Function nodes, or
as a specific way of using Takagi-Sugeno fuzzy models. Using the available
theory of Extreme Learning Machines, universal approximation of the SLM and an
upper bound on the number of models are proved mathematically, and an efficient
algorithm is proposed.


title: Dirac quasinormal modes in spherically symmetric regular black holes

abstract:
  Using the WKB approximation, massless and massive Dirac quasinormal modes
(QNMs) are studied in spherically symmetric regular spacetimes. We analyze the
relationships between QNM frequencies and the parameters (angular momentum
number $l$, magnetic monopole charge $\beta$ and the mass of the field $m$),
and discuss the extreme charge of magnetic monopole $\beta_{e}$ for spherically
symmetric regular black holes (BHs). Furthermore, we apply an expansion method
to expand QNMs in inverse powers of $L=l+1/2$, and confirm good precision with
$l>n$. Finally, we improve traditional finite difference method to be available
in massive Dirac case, and illuminate the dynamical evolution of massive Dirac
field.


title: Photo-z Quality Cuts and their Effect on the Measured Galaxy Clustering

abstract:
  Photometric galaxy surveys are an essential tool to further our understanding
of the large-scale structure of the universe, its matter and energy content and
its evolution. These surveys necessitate the determination of the galaxy
redshifts using photometric techniques (photo-z). Oftentimes, it is
advantageous to remove from the galaxy sample those for which one suspects that
the photo-z estimation might be unreliable. In this paper, we show that
applying these photo-z quality cuts blindly can grossly bias the measured
galaxy correlations within and across photometric redshift bins. We then extend
the work of Ho et al. (2012) and Ross et al. (2011) to develop a simple and
effective method to correct for this using the data themselves. Finally, we
apply the method to the Mega-Z catalog, containing about a million luminous red
galaxies in the redshift range 0.45 < z < 0.65. After splitting the sample into
four \Delta z = 0.05 photo-z bins using the BPZ algorithm, we see how our
corrections bring the measured galaxy auto- and cross-correlations into
agreement with expectations. We then look for the BAO feature in the four bins,
with and without applying the photo-z quality cuts, and find a broad agreement
between the BAO scales extracted in both cases. Intriguingly, we observe a
correlation between galaxy density and photo-z quality even before any photo-z
quality cuts are applied. This may be due to uncorrected observational effects
that result in correlated gradients across the sky of the galaxy density and
the galaxy photo-z precision. Our correction procedure could also help to
mitigate some of these systematic effects.


title:
On stability of the catenoid under vanishing mean curvature flow on
  Minkowski space

abstract:
  We establish basic local existence as well as a stability result concerning
small perturbations of the Catenoid minimal surface in $\R^3$ under hyperbolic
vanishing mean curvature flow.


title:
LIDT-DD: A new self-consistent debris disc model including radiation
  pressure and coupling collisional and dynamical evolution

abstract:
  In most current debris disc models, the dynamical and the collisional
evolutions are studied separately, with N-body and statistical codes,
respectively, because of stringent computational constraints. We present here
LIDT-DD, the first code able to mix both approaches in a fully self-consistent
way. Our aim is for it to be generic enough so as to be applied to any
astrophysical cases where we expect dynamics and collisions to be deeply
interlocked with one another: planets in discs, violent massive breakups,
destabilized planetesimal belts, exozodiacal discs, etc. The code takes its
basic architecture from the LIDT3D algorithm developed by Charnoz et al.(2012)
for protoplanetary discs, but has been strongly modified and updated in order
to handle the very constraining specificities of debris discs physics:
high-velocity fragmenting collisions, radiation-pressure affected orbits,
absence of gas, etc. In LIDT-DD, grains of a given size at a given location in
a disc are grouped into "super-particles", whose orbits are evolved with an
N-body code and whose mutual collisions are individually tracked and treated
using a particle-in-a-box prescription. To cope with the wide range of possible
dynamics, tracers are sorted and regrouped into dynamical families depending on
their orbits. The code retrieves the classical features known for debris discs,
such as the particle size distributions in unperturbed discs, the outer radial
density profiles (slope in -1.5) outside narrow collisionally active rings, and
the depletion of small grains in "dynamically cold" discs. The potential of the
new code is illustrated with the test case of the violent breakup of a massive
planetesimal within a debris disc. The main potential future applications of
the code are planet/disc interactions, and more generally any configurations
where dynamics and collisions are expected to be intricately connected.


title:
Second-Order Asymptotics for the Classical Capacity of Image-Additive
  Quantum Channels

abstract:
  We study non-asymptotic fundamental limits for transmitting classical
information over memoryless quantum channels, i.e. we investigate the amount of
classical information that can be transmitted when a quantum channel is used a
finite number of times and a fixed, non-vanishing average error is permissible.
We consider the classical capacity of quantum channels that are image-additive,
including all classical to quantum channels, as well as the product state
capacity of arbitrary quantum channels. In both cases we show that the
non-asymptotic fundamental limit admits a second-order approximation that
illustrates the speed at which the rate of optimal codes converges to the
Holevo capacity as the blocklength tends to infinity. The behavior is governed
by a new channel parameter, called channel dispersion, for which we provide a
geometrical interpretation.


title:
On the Conditions of Sparse Parameter Estimation via Log-Sum Penalty
  Regularization

abstract:
  For high-dimensional sparse parameter estimation problems, Log-Sum Penalty
(LSP) regularization effectively reduces the sampling sizes in practice.
However, it still lacks theoretical analysis to support the experience from
previous empirical study. The analysis of this article shows that, like
$\ell_0$-regularization, $O(s)$ sampling size is enough for proper LSP, where
$s$ is the non-zero components of the true parameter. We also propose an
efficient algorithm to solve LSP regularization problem. The solutions given by
the proposed algorithm give consistent parameter estimations under less
restrictive conditions than $\ell_1$-regularization.


title: Oracle Tractability of Skew Bisubmodular Functions

abstract:
  In this paper we consider skew bisubmodular functions as introduced in [9].
We construct a convex extension of a skew bisubmodular function which we call
Lov\'asz extension in correspondence to the submodular case. We use this
extension to show that skew bisubmodular functions given by an oracle can be
minimised in polynomial time.


title:
Measurement of \gamma\ from B->Dh decays at LHCb---including the effect
  of D0-D0bar mixing

abstract:
  I present a measurement of the CKM angle gamma from a combination of three
LHCb measurements using the tree decays B -> DK and B -> Dpi. These
measurements are based on a dataset corresponding to 1.0fb-1, collected in
2011. In contrast to what was presented at FPCP, these proceedings fully
include the effect of D0--D0b mixing on the combination.
  I also report on the inclusion of new, preliminary results on the Dalitz
analysis of B->DK, D->KShh, using a dataset corresponding to 3fb-1, collected
in 2011--2012.


title: Riesz transforms on compact Riemannian symmetric spaces of rank one

abstract:
  In this paper we prove mixed norm estimates for Riesz transforms related to
Laplace--Beltrami operators on compact Riemannian symmetric spaces of rank one.
These operators are closely related to the Riesz transforms for Jacobi
polynomials expansions. The key point is to obtain sharp estimates for the
kernel of the Jacobi--Riesz transforms with uniform control on the parameters,
together with an adaptation of Rubio de Francia's extrapolation theorem. The
latter results are of independent interest.


title:
Divergence of the Long Wavelength Collective Diffusion Coefficient in
  Quasi-one and Quasi-two Dimensional Colloid Suspensions

abstract:
  We report the results of experimental studies of the short time-long
wavelength behavior of collective particle displacements in
quasi-one-dimensional and quasi-two-dimensional colloid suspensions. Our
results are represented by the behavior of the hydrodynamic function H(q) that
relates the effective collective diffusion coefficient, D_e(q) with the static
structure factor S(q) and the self-diffusion coefficient of isolated particles
D_0: H(q)=D_e(q)S(q)/D_0. We find an apparent divergence of H(q) as q->0 with
the form H(q) proportional to q^-gamma, 1.7<gamma<1.9, for both q1D and q2D
colloid suspensions. Given that S(q) does not diverge as q=>0 we infer that
D_e(q) does. We provide evidence that this divergence arises from the interplay
of boundary conditions on the flow of the carrier liquid and many-body
hydrodynamic interactions between colloid particles that affect the long
wavelength behavior of the particle collective diffusion coefficient in the
suspension. We speculate that in the q1D and q2D systems studied the divergence
of H(q) might be associated with a q-dependent partial slip boundary condition,
specifically an effective slip length that increases with decreasing q. We also
verify, using data from the work of Lin, Rice and Weitz (J. Chem. Phys. 99,
9585 (1993)), the prediction by Bleibel et al (arXiv:1305.3715), that D_e(q)
for a monolayer of colloid particles constrained to lie in the interface
between two fluids diverges as 1/q as q->0. The verification of that
prediction, which is based on an analysis that allows two-dimensional colloid
motion embedded in three-dimensional suspending fluid motion, supports the
contention that the boundary conditions that define a q2D system play a very
important role in determining the long wavelength behavior of the collective
diffusion coefficient.


title: Beating O(nm) in approximate LZW-compressed pattern matching

abstract:
  Given an LZW/LZ78 compressed text, we want to find an approximate occurrence
of a given pattern of length m. The goal is to achieve time complexity
depending on the size n of the compressed representation of the text instead of
its length. We consider two specific definitions of approximate matching,
namely the Hamming distance and the edit distance, and show how to achieve
O(nm^0.5k^2) and O(nm^0.5k^3) running time, respectively, where k is the bound
on the distance. Both algorithms use just linear space. Even for very small
values of k, the best previously known solutions required O(nm) time. Our main
contribution is applying a periodicity-based argument in a way that is
computationally effective even if we need to operate on a compressed
representation of a string, while the previous solutions were either based on a
dynamic programming, or a black-box application of tools developed for
uncompressed strings.


title:
A perturbation density functional theory for the competition between
  inter and intramolecular association

abstract:
  Using the framework of Wertheim's thermodynamic perturbation theory we
develop the first density functional theory which accounts for intramolecular
association in chain molecules. To test the theory new Monte Carlo simulations
are performed at a fluid solid interface for a 4 segment chain which can both
intra and intermolecularly associate. The theory and simulation results are
found to be in excellent agreement. It is shown that the inclusion of
intramolecular association can have profound effects on interfacial properties
such as interfacial tension and the partition coefficient.


title: Dilepton Signatures of the Higgs Boson with Tau-jet Tagging

abstract:
  We consider the process $p p \to t {\bar t} H$. This process can give rise to
many signatures of the Higgs boson. The signatures can have electrons, muons
and jets. We consider the signatures that have two electrons/muons and jets.
Tagging of a tau jet and a bottom jet can help reduce the backgrounds
significantly. In particular, we examine the usefulness of the signatures
"isolated 2 electrons/muons + a bottom jet + a tau jet", "isolated 2
electrons/muons + 2 tau jets", "isolated 2 electrons/muons + 2 bottom jets + a
tau jet", and "isolated 2 electrons/muons + a bottom jet + 2 tau jets". We find
that signatures with two tau jets are useful. The signatures with one tau jet
are also useful, if we restrict to same-sign electrons/muons. These
requirements reduce the backgrounds due the process with Z-bosons + jets and
the production of a pair of top quarks. We show that these signatures may be
visible in the run II of the Large Hadron Collider.


title: Critical Behaviour of the Fuzzy Sphere

abstract:
  We study a multi-matrix model whose low temperature phase is a fuzzy sphere
that undergoes an evaporation transition as the temperature is increased. We
investigate finite size scaling of the system as the limiting temperature of
stability of the fuzzy sphere phase is approached. We find on theoretical
grounds that the system should obey scaling with specific heat exponent
\alpha=1/2, shift exponent \bar \lambda=4/3 and that the peak in the specific
heat grows with exponent \bar \omega=2/3. Using hybrid Monte Carlo simulations
we find good collapse of specific heat data consistent with a scaling ansatz
which give our best estimates for the scaling exponents as \alpha=0.50 \pm
0.01,\bar \lambda=1.41 \pm 0.08 and \bar \omega=0.66 \pm 0.08 .


title: Variable range of the RKKY interaction in edged graphene

abstract:
  The indirect exchange interaction is one of the key factors in determining
the overall alignment of magnetic impurities embedded in metallic host
materials. In this work we examine the range of this interaction in
magnetically-doped graphene systems in the presence of armchair edges using a
combination of analytical and numerical Green function (GF) approaches. We
consider both a semi-infinite sheet of graphene with a single armchair edge,
and also quasi-one-dimensional armchair edged graphene nanoribbons (GNRs).
While we find signals of the bulk decay rate in semi-infinite graphene and
signals of the expected one-dimensional decay rate in GNRs, we also find an
unusually rapid decay for certain instances in both, which manifests itself
whenever the impurities are located at sites which are a multiple of three
atoms from the edge. This decay behavior emerges from both the analytic and
numerical calculations, and the result for semi-infinite graphene can be
interpreted as an intermediate case between ribbon and bulk systems.


title: Entropy, Pressure and Duality for Gibbs plans in Ergodic Transport

abstract:
  Let $X$ be a finite set and $\Omega=\{1,...,d\}^{\mathbb{N}}$ be the
Bernoulli space. Denote by $\sigma$ the shift map acting on $\Omega$. For a
fixed probability $\mu$ on $X$ with supp($\mu$)$=X$, define $\Pi(\mu,\sigma)$
as the set of all Borel probabilities $\pi \in P(X\times \Omega)$ such that the
$x$-marginal of $\pi$ is $\mu $ and the $y$-marginal of $\pi$ is
$\sigma$-invariant. We consider a fixed Lipschitz cost function $c: X \times
\Omega \to \mathbb{R}$ and an associated Ruelle operator. We introduce the
concept of Gibbs plan, which is a probability on $X \times \Omega$. Moreover,
we define entropy, pressure and equilibrium plans. The study of equilibrium
plans can be seen as a generalization of the optimal cost problem where the
concept of entropy is introduced. We show that an equilibrium plan is a Gibbs
plan. Our main result is a Kantorovich duality Theorem on this setting. The
pressure plays an important role in the establishment of the notion of
admissible pair. Finally, given a parameter $\beta$, which plays the role of
the inverse of temperature, we consider equilibrium plans for $\beta c$ and its
limit $\pi_\infty$, when $\beta \to \infty$, which is also known as ground
state. We compare this with other previous results on Ergodic Transport in
temperature zero.

categories: math.DS cond-mat.stat-mech math-ph math.MP math.OC math.PR


title:
A Monte Carlo density functional theory for the competition between
  inter and intramolecular association in inhomogeneous fluids

abstract:
  A monte carlo density functional theory is developed for chain molecules
which both intra and intermolecularly associate. The approach can be applied
over a range of chain lengths. The theory is validated for the case of an
associating 4-mer fluid in a planar hard slit pore. Once validated the new
theory is used to study the effect of chain length and temperature on the
competition between intra and intermolecular association near a hard wall. We
show that this competition enhances intramolecular association near wall
contact and inverts the chain length dependence of the fraction bonded
intermolecularly in the inhomogeneous region.


title:
Spectroscopic direct detection of reflected light from extra-solar
  planets

abstract:
  At optical wavelengths, an exoplanet's signature is essentially reflected
light from the host star - several orders of magnitude fainter. Since it is
superimposed on the star spectrum its detection has been a difficult
observational challenge. However, the development of a new generation of
instruments like ESPRESSO and next generation telescopes like the E-ELT put us
in a privileged position to detect these planets' reflected light as we will
have access to extremely high signal-to-noise ratio spectra. With this work, we
propose an alternative approach for the direct detection of the reflected light
of an exoplanet. We simulated observations with ESPRESSO@VLT and HIRES@E-ELT of
several star+planet systems, encompassing 10h of the most favourable orbital
phases. To the simulated spectra we applied the Cross Correlation Function to
operate in a much higher signal-to-noise ratio domain than when compared with
the spectra. The use of the Cross-Correlation Function permitted us to recover
the simulated the planet signals at a level above 3 \sigma_{noise} significance
on several prototypical (e.g., Neptune type planet with a 2 days orbit with the
VLT at 4.4 \sigma_{noise} significance) and real planetary systems (e.g., 55
Cnc e with the E-ELT at 4.9 \sigma_{noise} significance). Even by using a more
pessimistic approach to the noise level estimation, where systematics in the
spectra increase the noise 2-3 times, the detection of the reflected light from
large close-orbit planets is possible. We have also shown that this kind of
study is currently within reach of current instruments and telescopes (e.g., 51
Peg b with the VLT at 5.2 \sigma_{noise} significance), although at the limit
of their capabilities.


title:
Evidence for a receding dust sublimation region around a supermassive
  black hole

abstract:
  The near-IR emission in Type 1 AGNs is thought to be dominated by the thermal
radiation from dust grains that are heated by the central engine in the
UV/optical and are almost at the sublimation temperature. A brightening of the
central source can thus further sublimate the innermost dust, leading to an
increase in the radius of the near-IR emitting region. Such changes in radius
have been indirectly probed by the measurements of the changes in the time lag
between the near-IR and UV/optical light variation. Here we report direct
evidence for such a receding sublimation region through the near-IR
interferometry of the brightest Type 1 AGN in NGC4151. The increase in radius
follows a significant brightening of the central engine with a delay of at
least a few years, which is thus the implied destruction timescale of the
innermost dust distribution. Compiling historic flux variations and radius
measurements, we also infer the reformation timescale for the inner dust
distribution to be several years in this galactic nucleus. More specifically
and quantitatively, we find that the radius at a given time seems to be
correlated with a long-term average of the flux over the previous several (~6)
years, instead of the instantaneous flux. Finally, we also report measurements
of three more Type 1 AGNs newly observed with the Keck interferometer, as well
as the second epoch measurements for three other AGNs.


title: Tonelli Lagrangian systems on the 2-torus and topological entropy

abstract:
  We study Tonelli Lagrangian systems on the 2-torus in energy levels above
Ma\~n\'e's strict critical value and analyize the structure of global
minimizers in the spirit of Morse, Hedlund and Bangert. In the case where the
topological entropy of the Euler-Lagrange flow on the fixed energy level
vanishes, we show that there are invariant tori for all rotation vectors
indicating integrable-like behavior on a large scale. On the other hand, using
a construction of Katok, we give examples of reversible Finsler geodesic flows
with vanishing topological entropy, but having ergodic components of positive
measure in the unit tangent bundle.


title:
Second-order properties and central limit theorems for geometric
  functionals of Boolean models

abstract:
  Let $Z$ be a Boolean model based on a stationary Poisson process $\eta$ of
compact, convex particles in Euclidean space ${\mathbb{R}}^d$. Let $W$ denote a
compact, convex observation window. For a large class of functionals $\psi$,
formulas for mean values of $\psi(Z\cap W)$ are available in the literature.
The first aim of the present work is to study the asymptotic covariances of
general geometric (additive, translation invariant and locally bounded)
functionals of $Z\cap W$ for increasing observation window $W$, including
convergence rates. Our approach is based on the Fock space representation
associated with $\eta$. For the important special case of intrinsic volumes,
the asymptotic covariance matrix is shown to be positive definite and can be
explicitly expressed in terms of suitable moments of (local) curvature measures
in the isotropic case. The second aim of the paper is to prove multivariate
central limit theorems including Berry-Esseen bounds. These are based on a
general normal approximation result obtained by the Malliavin--Stein method.


title: Efficient uncertainty propagation for network multiphysics systems

abstract:
  We consider a multiphysics system with multiple component models coupled
together through network coupling interfaces, i.e., a handful of scalars. If
each component model contains uncertainties represented by a set of parameters,
a straightfoward uncertainty quantification (UQ) study would collect all
uncertainties into a single set and treat the multiphysics model as a black
box. Such an approach ignores the rich structure of the multiphysics system,
and the combined space of uncertainties can have a large dimension that
prohibits the use of polynomial surrogate models. We propose an intrusive
methodology that exploits the structure of the network coupled multiphysics
system to efficiently construct a polynomial surrogate of the model output as a
function of uncertain inputs. Using a nonlinear elimination strategy, we treat
the solution as a composite function: the model outputs are functions of the
coupling terms which are functions of the uncertain parameters. The composite
structure allows us to construct and employ a reduced polynomial basis that
depends on the coupling terms; the basis can be constructed with many fewer
system solves than the naive approach, which results in substantial
computational savings. We demonstrate the method on an idealized model of a
nuclear reactor.


title:
Search for MeV dark photons in a light-shining-through-walls experiment
  at CERN

abstract:
  In addition to gravity, there might be another very weak interaction between
the ordinary and dark matter transmitted by U'(1) gauge bosons A' (dark
photons) mixing with our photons. If such A's exist, they could be searched for
in a light-shining-through-a-wall experiment with a high energy electron beam.
The electron energy absorption in a calorimeter (CAL1) is accompanied by the
emission of bremsstrahlung A's in the reaction eZ -> eZA' of electrons
scattering on nuclei due to the \gamma - A' mixing. A part of the primary beam
energy is deposited in the CAL1, while the rest of the energy is transmitted by
the A' through the "CAL1 wall" and deposited in another downstream calorimeter
CAL2 by the e+e- pair from the A'->e+e- decay in flight. Thus, the A's could be
observed by looking for an excess of events with the two-shower signature
generated by a single high energy electron in the CAL1 and CAL2. A proposal to
perform such an experiment to probe the still unexplored area of the mixing
strength 10^{-5} < \epsilon < 10^{-3} and masses M_{A'} < 100 MeV by using
10-300 GeV electron beams from the CERN SPS is presented. The experiment can
provide complementary coverage of the parameter space, which is intended to be
probed by other searches. It has also a capability for a sensitive search for
A's decaying invisibly to dark-sector particles, such as dark matter, which
could cover a significant part of the still allowed parameter space.


title: Phenomenological Study of Residual Z^s_2 and Zbar^s_2 Symmetries

abstract:
  The phenomenological consequences of the residual Z^s_2 and Zbar^s_2
symmetries are explored in detail. With a precisely measured value of the
reactor angle, these two residual symmetries predict distinct distributions for
the Dirac CP phase and the atmospheric angle, which leads to the possibility of
identifying them at neutrino experiments. For both symmetries, it is possible
to resolve the neutrino mass hierarchy in most of the parameter space, and they
can be distinguished from one another if the true residual symmetry is Z^s_2
and the atmospheric angle is non-maximal. These results are obtained using an
equally split schedule: a 1.5-year run of neutrinos and a 1.5-year run of
antineutrinos at NOvA together with a 2.5-year run of neutrinos and a 2.5-year
run of antineutrinos at T2K. This schedule can significantly increase and
stabilize the sensitivities to the mass hierarchy and the octant of the
atmospheric angle with only a moderate compromise to the sensitivity of
distinguishing Z^s_2 and Zbar^s_2.


title: Branch Cuts in Maple 17

abstract:
  Accurate and comprehensible knowledge about the position of branch cuts is
essential for correctly working with multi-valued functions, such as the square
root and logarithm. We discuss the new tools in Maple 17 for calculating and
visualising the branch cuts of such functions, and others built up from them.
The cuts are described in an intuitive and accurate form, offering substantial
improvement on the descriptions previously available.


title: General Relativistic N-body simulations in the weak field limit

abstract:
  We develop a formalism for General Relativistic N-body simulations in the
weak field regime, suitable for cosmological applications. The problem is kept
tractable by retaining the metric perturbations to first order, the first
derivatives to second order and second derivatives to all orders, thus taking
into account the most important nonlinear effects of Einstein gravity. It is
also expected that any significant "backreaction" should appear at this order.
We show that the simulation scheme is feasible in practice by implementing it
for a plane-symmetric situation and running two test cases, one with only cold
dark matter, and one which also includes a cosmological constant. For these
plane-symmetric situations, the deviations from the usual Newtonian N-body
simulations remain small and, apart from a non-trivial correction to the
background, can be accurately estimated within the Newtonian framework. The
correction to the background scale factor, which is a genuine "backreaction"
effect, can be robustly obtained with our algorithm. Our numerical approach is
also naturally suited for the inclusion of extra relativistic fields and thus
for dark energy or modified gravity simulations.


title: A diffraction effect in X-ray area detectors

abstract:
  When an X-ray area detector based on a single crystalline material, for
instance, a state of the art hybrid pixel detector, is illuminated from a point
source by monochromatic radiation, a pattern of lines appears which overlays
the detected image. These lines can be easily found by scattering experiments
with smooth patterns, such as small-angle X-ray scattering. The origin of this
effect is the Bragg reflection in the sensor layer of the detector.
Experimental images are presented over a photon energy range from 3.4 keV to 10
keV, together with a theoretical analysis. The intensity of this pattern is up
to 20%, which can disturb the evaluation of scattering and diffraction
experiments. The patterns can be exploited to check the alignment of the
detector surface with the direct beam, and the alignment of individual detector
modules with each other in the case of modular detectors, as well as for the
energy calibration of the radiation.


title:
On the Effectiveness of Punishments in a Repeated Epidemic Dissemination
  Game

abstract:
  This work uses Game Theory to study the effectiveness of punishments as an
incentive for rational nodes to follow an epidemic dissemination protocol. The
dissemination process is modeled as an infinite repetition of a stage game. At
the end of each stage, a monitoring mechanism informs each player of the
actions of other nodes. The effectiveness of a punishing strategy is measured
as the range of values for the benefit-to-cost ratio that sustain cooperation.
This paper studies both public and private monitoring. Under public monitoring,
we show that direct reciprocity is not an effective incentive, whereas full
indirect reciprocity provides a nearly optimal effectiveness. Under private
monitoring, we identify necessary conditions regarding the topology of the
graph in order for punishments to be effective. When punishments are
coordinated, full indirect reciprocity is also effective with private
monitoring.


title:
The effect of the Perdew-Zunger self-interaction correction to density
  functionals on the energetics of small molecules

abstract:
  Self-consistent calculations using the Perdew-Zunger self-interaction
correction (PZ-SIC) to local density and gradient dependent energy functionals
are presented for the binding energy and equilibrium geometry of small
molecules as well as energy barriers of reactions. The effect of the correction
is to reduce binding energy and bond lengths and increase activation energy
barriers when bond breaking is involved. The accuracy of the corrected
functionals varies strongly, the correction to the binding energy being too
weak for the local density approximation but too strong for the gradient
dependent functionals considered. For the Perdew, Burke, and Ernzerhof (PBE)
functional, a scaling of the PZ-SIC by one half gives improved results on
average for both binding energy and bond lengths. The PZ-SIC does not
necessarily give more accurate total energy, but it can result in a better
cancellation of errors. An essential aspect of these calculations is the use of
complex orbitals. A restriction to real orbitals leads to less accurate results
as was recently shown for atoms [S. Kl\"upfel, P. Kl\"upfel, and H. J\'onsson,
Phys. Rev. A {84}, 050501 (2011)]. The molecular geometry of radicals can be
strongly affected by PZ-SIC. An incorrect, non-linear structure of the \ce{C2H}
radical predicted by PBE is corrected by PZ-SIC. The \ce{CH3} radical is
correctly predicted to be planar when complex orbitals are used, while it is
non-planar when the PZ-SIC calculation is restricted to real orbitals.

categories: physics.atm-clus physics.chem-ph physics.comp-ph quant-ph


title:
Realization of a two-channel Kondo model with Josephson junction
  networks

abstract:
  We show that- in the quantum regime- a Josephson junction rhombi chain (i.e.
a Josephson junction chain made by rhombi formed by joining 4 Josephson
junctions) may be effectively mapped onto a quantum Hamiltonian describing
Ising spins in a transverse magnetic field with open boundary conditions. Then,
we elucidate how a Y-shaped network fabricated with 3 Josephson Junction Rhombi
chains may be used as a quantum device realizing the two channel Kondo model
recently proposed by Tsvelik. We point out that the emergence of a 2 channel
Kondo effect in this superconducting network may be probed through the
measurement of a pertinent Josephson current.


title: Thermoelectric properties of ${\beta}$-FeSi$_{\text2}$

abstract:
  We investigate the thermoelectric properties of ${\beta}$-FeSi$_{\text2}$
using first principles electronic structure and Boltzmann transport
calculations. We report a high thermopower for both \textit{p}- and
\textit{n}-type ${\beta}$-FeSi$_{\text2}$ over a wide range of carrier
concentration and in addition find the performance for \textit{n}-type to be
higher than for the \textit{p}-type. Our results indicate that, depending upon
temperature, a doping level of 3$\times10{^{20}}$ - 2$\times10{^{21}}$
cm${^{-3}}$ may optimize the thermoelectric performance.


title: Optimal unbiased state characterization

abstract:
  We propose a general approach to characterize states of a bipartite system
composed by a fully controllable and an unaccessible subsystems. The method is
based on the measuring interference between states of the uncontrollable
subsystem obtained after projecting an appropriately transformed bipartite
state on the basis of the accessible subsystem by local operations.


title: Geometric Waldspurger periods II

abstract:
  In this paper we extend the calculation of the geometric Waldspurger periods
from our paper math/0510110 to the case of ramified coverings. We give some
applications to the study of Whittaker coefficients of the theta-lifting of
automorphic sheaves from PGL_2 to the metaplectic group Mp_2, they agree with
our conjectures from arXiv:1211.1596. In the process of the proof, we get some
new automorphic sheaves for GL_2 in the ramified setting. We also formulate
stronger conjectures about Waldspurger periods and geometric theta-lifting for
the dual pair (SL_2, Mp_2).


title:
Low regularity well-posedness for the 2D Maxwell-Klein-Gordon equation
  in the Coulomb gauge

abstract:
  We consider the Maxwell-Klein-Gordon equation in 2D in the Coulomb gauge. We
establish local well-posedness for $s=\frac 14+\epsilon$ for data for the
spatial part of the gauge potentials and for $s=\frac 58+\epsilon$ for the
solution $\phi$ of the gauged Klein-Gordon equation. The main tool for handling
the wave equations is the product estimate established by D'Ancona, Foschi, and
Selberg. Due to low regularity, we are unable to use the conventional
approaches to handle the elliptic variable $A_0$, so we provide a new approach.


title: Light-induced gauge fields for ultracold atoms

abstract:
  Gauge fields are central in our modern understanding of physics at all
scales. At the highest energy scales known, the microscopic universe is
governed by particles interacting with each other through the exchange of gauge
bosons. At the largest length scales, our universe is ruled by gravity, whose
gauge structure suggests the existence of a particle - the graviton - that
mediates the gravitational force. At the mesoscopic scale, solid-state systems
are subjected to gauge fields of different nature: materials can be immersed in
external electromagnetic fields, but they can also feature emerging gauge
fields in their low-energy description. In this review, we focus on another
kind of gauge field: those engineered in systems of ultracold neutral atoms. In
these setups, atoms are suitably coupled to laser fields that generate
effective gauge potentials in their description. Neutral atoms "feeling"
laser-induced gauge potentials can potentially mimic the behavior of an
electron gas subjected to a magnetic field, but also, the interaction of
elementary particles with non-Abelian gauge fields. Here, we review different
realized and proposed techniques for creating gauge potentials - both Abelian
and non-Abelian - in atomic systems and discuss their implication in the
context of quantum simulation. While most of these setups concern the
realization of background and classical gauge potentials, we conclude with more
exotic proposals where these synthetic fields might be made dynamical, in view
of simulating interacting gauge theories with cold atoms.

categories: cond-mat.quant-gas cond-mat.mes-hall hep-lat hep-th quant-ph


title:
Stopping the SuperSpreader Epidemic: the lessons from SARS (with,
  perhaps, applications to MERS)

abstract:
  I discuss the so-called SuperSpreader epidemic, for which SARS is the
canonical examples (and, perhaps, MERS will be another). I use simulation by an
agent-based model as well as the mathematics of multi-type branching-processes
to illustrate how the SS epidemic differs from the more familiar uniform
epidemic (e.g., caused by influenza). The conclusions may surprise the reader:
(a) The SS epidemic must be described by at least two numbers, such as the mean
reproductive number (of "secondary" cases caused by a "primary case"), R0, and
the variance of same, call it V0; (b) Even if R0 > 1, if V0 >> R0 the
probability that an infection-chain caused by one primary case goes extinct
without intervention may be close to one (e.g., 0.97); (c) The SS epidemic may
have a long "kindling period" in which sporadic cases appear (transmitted from
some unknown host) and generate a cluster of cases, but the chains peter out,
perhaps generating a false sense of security that a pandemic will not occur;
(d) Interventions such as isolation (or contact-tracing and secondary case
isolation) may prove efficacious even without driving R0 below one; (e) The
efficacy of such interventions diminishes, but slowly, with increasing V0 at
fixed R0. From these considerations, I argue that the SS epidemic has dynamics
sufficiently distinct from the uniform case that efficacious public-health
interventions can be designed even in the absence of a vaccine or other form of
treatment.


title:
Non-degeneracy of some Sobolev Pseudo-norms of fractional Brownian
  motion

abstract:
  Applying an upper bound estimate for small $L^{2}$ ball probability for
fractional Brownian motion (fBm), we prove the non-degeneracy of some Sobolev
pseudo-norms of fBm.


title:
Root-theoretic Young diagrams and Schubert calculus: planarity and the
  adjoint varieties

abstract:
  We study root-theoretic Young diagrams to investigate the existence of a
Lie-type uniform and nonnegative combinatorial rule for Schubert calculus. We
provide formulas for (co)adjoint varieties of classical Lie type. This is a
simplest case after the (co)minuscule family (where a rule has been proved by
H.Thomas and the second author using work of R.Proctor). Our results build on
earlier Pieri-type rules of P.Pragacz-J.Ratajski and of
A.Buch-A.Kresch-H.Tamvakis. Specifically, our formula for OG(2,2n) is the first
complete rule for a case where diagrams are non-planar. Yet the formulas
possess both uniform and non-uniform features. Using these classical type
rules, as well as results of P.-E.Chaput-N.Perrin in the exceptional types, we
suggest a connection between polytopality of the set of nonzero Schubert
structure constants and planarity of the diagrams. This is an addition to work
of A.Klyachko and A.Knutson-T.Tao on the Grassmannian and of
K.Purbhoo-F.Sottile on cominuscule varieties, where the diagrams are always
planar.


title: Percolation on random networks with arbitrary k-core structure

abstract:
  The k-core decomposition of a network has thus far mainly served as a
powerful tool for the empirical study of complex networks. We now propose its
explicit integration in a theoretical model. We introduce a Hard-core Random
Network model that generates maximally random networks with arbitrary degree
distribution and arbitrary k-core structure. We then solve exactly the bond
percolation problem on the HRN model and produce fast and precise analytical
estimates for the corresponding real networks. Extensive comparison with
selected databases reveals that our approach performs better than existing
models, while requiring less input information.


title:
Specific chemical reactivities of spatially separated 3-aminophenol
  conformers with cold Ca$^+$ ions

abstract:
  Many molecules exhibit multiple rotational isomers (conformers) that
interconvert thermally and are difficult to isolate. Consequently, a precise
characterization of their role in chemical reactions has proven challenging. We
have probed the reactivity of specific conformers using an experimental
technique based on their spatial separation in a molecular beam by
electrostatic deflection. The separated conformers react with a target of
Coulomb-crystallized ions in a trap. In the reaction of Ca$^+$ with
3-aminophenol, we find a twofold larger rate constant for the \textit{cis}-
compared to the \textit{trans}-conformer (differentiated by the O-H bond
orientation). This result is explained by conformer-specific differences in the
long-range ion-molecule interaction potentials. Our approach demonstrates the
possibility of controlling reactivity through selection of conformational
states.


title: Rigidity of Fiber Bunched Cocycles

abstract:
  We prove a rigidity theorem for fiber bunched matrix-valued Holder cocycles
over hyperbolic homeomorphisms. More precisely, we show that two such cocycles
are cohomologous if and only if they have conjugated periodic data.


title: Note on universal description of heavy and light mesons

abstract:
  The experimental spectrum of excited S-wave vector mesons with hidden quark
flavor reveals a remarkable property: For all flavors, it is approximately
linear in mass squared, $m_n^2\approx a(n+b)$, $n$ is the radial quantum
number. We draw attention to the fact that such a universal behavior for any
quark mass cannot be obtained in a natural way within the usual
semirelativistic potential and string-like models - if the Regge-like behavior
is reproduced for the mesons made of the light quarks, the trajectories become
essentially nonlinear for the heavy-quark sector. In reality, however, the
linearity for the heavy mesons appears to be even better than for the light
ones. In addition, the slope a is quite different for different quark flavors.
This difference is difficult to understand within the QCD string approach since
the slope measures the interaction strength among quarks. We propose a simple
way for reparametrization of the vector spectrum in terms of quark masses and
universal slope and intercept. Our model-independent analysis suggests that the
quarks of any mass should be regarded as static sources inside mesons while the
interaction between quarks is substantially relativistic.


title:
Interface limited growth of heterogeneously nucleated ice in supercooled
  water

abstract:
  Heterogeneous ice growth exhibits a maximum in freezing rate arising from the
competition between kinetics and the thermodynamic driving force between the
solid and liquid states. Here, we use molecular dynamics simulations to
elucidate the atomistic details of this competition, focusing on water
properties in the interfacial region along the secondary prismatic direction.
The crystal growth velocity is maximized when the efficiency of converting
interfacial water molecules to ice, collectively known as the attachment
kinetics, is greatest. We find water molecules that contact the intermediate
ice layer in concave regions along the atomistically roughened surface are more
likely to freeze directly. The increased roughening of the solid surface at
large undercoolings consequently plays an important limiting role on the rate
of ice growth, as water molecules are unable to integrate into increasingly
deeper surface pockets. These results provide insights into the molecular
mechanisms for self-assembly of solid phases that are important in many
biological and atmospheric processes.


title: An accordion lattice based on the Talbot effect

abstract:
  We introduce an idea of producing an optical lattice relied on the Talbot
effect. Our alternative scheme is based on the interference of light behind a
diffraction grating in the near-field regime. We demonstrate 1-D and 2-D
optical lattices with the simulations and experiments. This Talbot optical
lattice can be broadly used from quantum simulations to quantum information.
The Talbot effect is usually used in lensless optical systems, therefore it
provides small aberrations.


title:
Resource Allocation in MIMO Radar With Multiple Targets for Non-Coherent
  Localization

abstract:
  In a MIMO radar network the multiple transmit elements may emit waveforms
that differ on power and bandwidth. In this paper, we are asking, given that
these two resources are limited, what is the optimal power, optimal bandwidth
and optimal joint power and bandwidth allocation for best localization of
multiple targets. The well known Cr\'amer-Rao lower bound for target
localization accuracy is used as a figure of merit and approximate solutions
are found by minimizing a sequence of convex problems. Their quality is
assessed through extensive numerical simulations and with the help of a
lower-bound on the true solution. Simulations results reveal that bandwidth
allocation policies have a definitely stronger impact on performance than
power.


title: Theories of Glass Formation and the Glass Transition

abstract:
  This key-issues review is a plea for a new focus on simpler and more
realistic models of glass-forming fluids. It seems to me that we have too often
been led astray by sophisticated mathematical models that beautifully capture
some of the most intriguing features of glassy behavior, but are too
unrealistic to provide bases for predictive theories. As illustrations of what
I mean, the first part of this article is devoted to brief summaries of
imaginative, sensible, but disparate and often contradictory ideas for solving
glass problems. Almost all of these ideas remain alive today, with their own
enthusiastic advocates. I then describe numerical simulations, mostly by H.
Tanaka and coworkers, in which it appears that very simple, polydisperse
systems of hard disks and spheres develop long range, Ising-like,
bond-orientational order as they approach glass transitions. Finally, I
summarize my recent proposal that topologically ordered clusters of particles,
in disordered environments, tend to become aligned with each other as if they
were two-state systems, and thus produce the observed Ising-like behavior.
Neither Tanaka's results nor my proposed interpretation of them fit comfortably
within any of the currently popular glass theories.


title:
Second-order equations and local isometric immersions of
  pseudo-spherical surfaces

abstract:
  We consider the class of differential equations that describe
pseudo-spherical surfaces of the form $u\_t=F(u,u\_x,u\_{xx})$ and
$u\_{xt}=F(u, u\_x)$ given in Chern-Tenenblat \cite{ChernTenenblat} and
Rabelo-Tenenblat \cite{RabeloTenenblat90}. We answer the following question:
Given a pseudo-spherical surface determined by a solution $u$ of such an
equation, do the coefficients of the second fundamental form of the local
isometric immersion in $\mathbb{R}^3$ depend on a jet of finite order of $u$?
We show that, except for the sine-Gordon equation, where the coefficients
depend on a jet of order zero, for all other differential equations, whenever
such an immersion exists, the coefficients are universal functions of $x$ and
$t$, independent of $u$.


title: Self tolerance in a minimal model of the idiotypic network

abstract:
  We consider the problem of self tolerance in the frame of a minimalistic
model of the idiotypic network. A node of this network represents a population
of B lymphocytes of the same idiotype which is encoded by a bit string. The
links of the network connect nodes with (nearly) complementary strings. The
population of a node survives if the number of occupied neighbours is not too
small and not too large. There is an influx of lymphocytes with random idiotype
from the bone marrow. Previous investigations have shown that this system
evolves toward highly organized architectures, where the nodes can be
classified into groups according to their statistical properties. The building
principles of these architectures can be analytically described and the
statistical results of simulations agree very well with results of a modular
mean field theory. In this paper we present simulation results for the case
that one or several nodes, playing the role of self, are permanently occupied.
We observe that the group structure of the architecture is very similar to the
case without self antigen, but organized such that the neighbours of the self
are only weakly occupied, thus providing self tolerance. We also treat this
situation in mean field theory which give results in good agreement with data
from simulation.


title: Tropical (1, 1)-homology for floor decomposed surfaces

abstract:
  The tropical (p, q)-homology groups of Itenberg, Katzarkov, Mikhalkin and
Zharkov are the tropical analogues of the Hodge decomposition of the cohomology
of complex algebraic varieties. There is a well-defined intersection pairing on
tropical (1, 1)-classes of a compact non-singular tropical surface. Here we
compute directly the (1, 1)-homology of a non-singular floor decomposed
tropical surface in tropical projective space, along with the intersection
form.


title: Compositories and Gleaves

abstract:
  Sheaves are objects of a local nature: a global section is determined by how
it looks locally. Hence, a sheaf cannot describe mathematical structures which
contain global or nonlocal geometric information. To fill this gap, we
introduce the theory of "gleaves", which are presheaves equipped with an
additional "gluing operation" of compatible pairs of local sections. This
generalizes the conditional product structures of Dawid and Studen\'y, which
correspond to gleaves on distributive lattices. Our examples include the gleaf
of metric spaces and the gleaf of joint probability distributions. A result of
Johnstone shows that a category of gleaves can have a subobject classifier
despite not being cartesian closed.
  Gleaves over the simplex category $\Delta$, which we call compositories, can
be interpreted as a new kind of higher category in which the composition of an
$m$-morphism and an $n$-morphism along a common $k$-morphism face results in an
$(m+n-k)$-morphism. The distinctive feature of this composition operation is
that the original morphisms can be recovered from the composite morphism as
initial and final faces. Examples of compositories include nerves of categories
and compositories of higher spans.


title: Quaternion representation and symplectic spin tomography

abstract:
  Quantum tomography for continuous variables is based on the symplectic
transformation group acting in the phase space. A particular case of symplectic
tomography is optical tomography related to the action of a special orthogonal
group. In the tomographic description of spin states, the connection between
special unitary and special orthogonal groups is used. We analyze the
representation for spin tomography using the Cayley-Klein parameters and
discuss an analog of symplectic tomography for discrete variables. We propose a
representation for tomograms of discrete variables through quaternions and
employ the qubit-state tomogram to illustrate the method elaborated.


title:
The quantum ultra-cold neutron gas trapped in the two-dimensional
  harmonic oscillator potential on the Earth's gravitational field

abstract:
  In our previous paper, we have investigated the thermodynamics of the quantum
ultra-cold neutron gas trapped in the two-dimensional square-well potential on
the Earth's gravitational field. We have pointed out that they have strong
dependence on the shape of the trapping potential. In the present paper, we
estimate the Fermi energy and the density distribution of the Fermi gas with
two-dimensional harmonic oscillator potential, instead of the square-well
potential. Then we discuss them in terms of the Fermi energy and the density
distribution as compared with both of cases.


title:
One-Dimensional Waveguide Coupled to Multiple Qubits: Photon-Photon
  Correlations

abstract:
  For a one-dimensional (1D) waveguide coupled to two or three qubits, we show
that the photon-photon correlations have a wide variety of behavior, with
structure that depends sensitively on the frequency and on the qubit-qubit
separation $L$. We study the correlations by calculating the second-order
correlation function $g_2(t)$ in which the interference among the photons
multiply scattered from the qubits causes rich structure. In one case, for
example, transmitted and reflected photons are both bunched initially, but then
become strongly anti-bunched for a long time interval. We first calculate the
correlation function $g_2(t)$ including non-Markovian effects and then show
that a much simpler Markovian treatment, which can be solved analytically, is
accurate for small qubit separation. As a result, the non-classical properties
of microwaves in a 1D waveguide coupled to many superconducting qubits with
experimentally accessible separation $L$ could be readily explored with our
approach.


title: Integer-Forcing Source Coding

abstract:
  Integer-Forcing (IF) is a new framework, based on compute-and-forward, for
decoding multiple integer linear combinations from the output of a Gaussian
multiple-input multiple-output channel. This work applies the IF approach to
arrive at a new low-complexity scheme, IF source coding, for distributed lossy
compression of correlated Gaussian sources under a minimum mean squared error
distortion measure. All encoders use the same nested lattice codebook. Each
encoder quantizes its observation using the fine lattice as a quantizer and
reduces the result modulo the coarse lattice, which plays the role of binning.
Rather than directly recovering the individual quantized signals, the decoder
first recovers a full-rank set of judiciously chosen integer linear
combinations of the quantized signals, and then inverts it. In general, the
linear combinations have smaller average powers than the original signals. This
allows to increase the density of the coarse lattice, which in turn translates
to smaller compression rates. We also propose and analyze a one-shot version of
IF source coding, that is simple enough to potentially lead to a new design
principle for analog-to-digital converters that can exploit spatial
correlations between the sampled signals.


title: Exploring anti-reflection modes in disordered media

abstract:
  Sensing and manipulating targets hidden under scattering media are universal
problems that take place in applications ranging from deep-tissue optical
imaging to laser surgery. A major issue in these applications is the shallow
light penetration caused by multiple scattering that reflects most of incident
light. Although advances have been made to eliminate image distortion by a
scattering medium, dealing with the light reflection has remained unchallenged.
Here we present a method to minimize reflected intensity by finding and
coupling light into the anti-reflection modes of a scattering medium. In doing
so, we achieved more than a factor of 3 increase in light penetration. Our
method of controlling reflected waves makes it readily applicable to in vivo
applications in which detector sensors can only be positioned at the same side
of illumination and will therefore lay the foundation of advancing the working
depth of many existing optical imaging and treatment technologies.


title: Quartz Plate Calorimetry for CMS HE Upgrade

abstract:
  Analysis of the CMS data and the simulation prediction based on these results
indicate that the performance of the current scintillators in the CMS Hadron
Endcap Calorimeter (HE) tiles will degrade dramatically in the High Luminosity
LHC (HL-LHC) era. In order to continue the physics program in this region, the
HE tiles will need to be replaced. The new tiles should have
comparable/improved performance, be radiation hard, reliable and robust.


title: On embeddings of $C_0(K)$ spaces into $C_0(L,X)$ spaces

abstract:
  Let $C_0(K, X)$ denote the space of all continuous $X$-valued functions
defined on the locally compact Hausdorff space $K$ which vanish at infinity,
provided with the supremum norm. If $X$ is the scalar field, we denote $C_0(K,
X)$ by simply $C_0(K)$. In this paper we prove that for locally compact
Hausdorff spaces $K$ and $L$ and for Banach space $X$ containing no copy of
$c_0$, if there is a isomorphic embedding of $C_0(K)$ into $C_0(L,X)$ where
either $X$ is separable or $X^*$ has the Radon-Nikod\'ym property, then either
$K$ is finite or $|K|\leq |L|$. As a consequence of this result, if there is a
isomorphic embedding of $C_0(K)$ into $C_0(L,X)$ where $X$ contains no copy of
$c_0$ and $L$ is scattered, then $K$ must be scattered.


title: Determinantal representations of semi-hyperbolic polynomials

abstract:
  We prove a generalization of the Hermitian version of the Helton-Vinnikov
determinantal representation of hyperbolic polynomials to the class of
semi-hyperbolic polynomials, a strictly larger class, as shown by an example.
We also prove that certain hyperbolic polynomials affine in two out of four
variables divide a determinantal polynomial. The proofs are based on work
related to polynomials with no zeros on the bidisk and tridisk.


title: Pseudo-Diagonals and Uniqueness Theorems

abstract:
  We examine a certain type of abelian C*-subalgebras that allow one to give a
unified treatment of two uniqueness theorems: for graph C*-algebras and for
certain reduced crossed products.


title: Enrichment of deeply penetrating waves in disordered media

abstract:
  Waves incident to a highly scattering medium are incapable of penetrating
deep into the medium due to the diffusion process induced by multiple
scattering. This poses a fundamental limitation to optically imaging, sensing,
and manipulating targets embedded in opaque scattering layers such as
biological tissues. One strategy for mitigating the shallow wave penetration is
to exploit eigenmodes with anomalously high transmittance existing in any
disordered medium. When waves are coupled to these eigenmodes, strong
constructive wave interference enhances deeply penetrating waves. However,
finding such eigenmodes has been a challenging task due to the complexity of
disordered media. In this Letter, we present an iterative wavefront control
method that selectively enriches the coupling of incident beam to
high-transmission eigenmodes. Specifically, we refined the high-transmission
eigenmodes from an arbitrary initial wave by either maximizing transmitted wave
intensity or minimizing reflected wave intensity. Using the proposed method, we
achieved more than a factor of 3 increases in light transmission through a
scattering medium exhibiting hundreds of scattering events. Our approach is
readily applicable to in vivo applications in which only the detection of
reflected waves is available. Enhancing light penetration will lead to
improving the working depth of optical imaging and treatment techniques.


title:
Partial results on the convexity of the Parisi functional with PDE
  approach

abstract:
  We investigate the convexity problem for the Parisi functional defined on the
space of the so-called functional ordered parameters in the
Sherrington-Kirkpatrick model. In the recent work of Panchenko [3], he proved
that this functional is convex along one-sided directions with a probabilistic
method. In this paper, we will study this problem with a PDE approach that
simplifies his original proof and presents more general results.