title:
Eigenvalues of Laplacian and multi-way isoperimetric constants on
  weighted Riemannian manifolds

abstract:
  We investigate the distribution of eigenvalues of the weighted Laplacian on
closed weighted Riemannian manifolds of nonnegative Bakry-\'Emery Ricci
curvature. We derive some universal inequalities among eigenvalues of the
weighted Laplacian on such manifolds. These inequalities are quantitative
versions of the previous theorem by the author with Shioya. We also study some
geometric quantity, called multi-way isoperimetric constants, on such manifolds
and obtain similar universal inequalities among them. Multi-way isoperimetric
constants are generalizations of the Cheeger constant. Extending and following
the heat semigroup argument by Ledoux and E. Milman, we extend the Buser-Ledoux
result to the $k$-th eigenvalue and the $k$-way isoperimetric constant. As a
consequence the $k$-th eigenvalue of the weighted Laplacian and the $k$-way
isoperimetric constant are equivalent up to polynomials of $k$ on closed
weighted manifolds of nonnegative Bakry-\'Emery Ricci curvature.


title: Stabilizing the Semilocal String with a Dilatonic Coupling

abstract:
  We demonstrate that the stability of the semilocal vortex can be
significantly improved by the presence of a dilatonic coupling of the form
e^\frac{q | \Phi |^2}{\eta^2} F_{\mu \nu}F^{\mu \nu} with q>0 where \eta is the
scale of symmetry breaking that gives rise to the vortex. For q=0 we obtain the
usual embedded (semilocal) Nielsen-Olesen vortex. We find the stability region
of the parameter \beta = (\frac{m_\Phi}{m_A})^2 (m_\Phi and m_A are the masses
of the scalar and gauge fields respectively). We show that the stability region
of \beta is 0<\beta<\beta_{max}(q) where \beta_{max}(q=0)=1 (as expected) and
\beta_{max}(q) is an increasing function of q. This result may have significant
implications for the stability of the electroweak vortex in the presence of a
dilatonic coupling (dilatonic electroweak vortex).


title: A Moser-Trudinger inequality for the singular Toda system

abstract:
  In this paper we prove a sharp version of the Moser-Trudinger inequality for
the Euler-Lagrange functional of a singular Toda system, motivated by the study
of models in Chern-Simons theory. Our result extends those for the scalar case,
as well as for the regular Toda system. We expect this inequality to be a basic
tool to attack variationally the existence problem under general assumptions.


title: The cosmology of a fundamental scalar

abstract:
  We observe that the standard homogeneous cosmologies, those of Minkowski, de
Sitter, and anti-de Sitter, which form the matrix for the Robertson--Walker
scale factor, live naturally as isolated points inside a larger family of
conformally flat metrics obtained by allowing a tensor containing the
information of conformal symmetry breaking to be more general. So the standard
cosmological metrics are parametrically unstable in this sense, and therefore
unphysical. When we pass to the stable family of perturbed metrics, we
immediately encounter a scalar field, which drives the conformal expansion of
the universe and which automatically obeys the non-linear sine-Gordon equation.
The Lagrangian for the sine-Gordon equation is a cosine potential agreeing to
the fourth order with the potential used in the approach to the generation of
mass in gauge theories. Accordingly we identify our geometric scalar
field---actually of the type of an abelian gauge field---with the recently
discovered scalar field. There are two constants in the theory: the first,
named $m$, is positive and defines a mass scale for the universe; the second,
named $\Lambda$, is the cosmological constant. For the space-time to be
everywhere non-singular, equivalently for the (strict) dominant energy
condition to hold, these constants must obey the inequality $\Lambda > m^2/4$.


title:
Mathematize urbes by humanizing them: Cities as Isobenefit Landscapes.
  Psycho-Economical distances and Isobenefit Lines

abstract:
  The city reading proposed is a modern postmodern urbanism approach which
quantifies but by passing through subjectivism. The isobenefit lines shown
translate cities into benefit landscapes, subjective and continually changeable
according to personal moods needs preferences and urban transformations. They
read attractiveness and how they flow throughout the city. Doing it for each
urban point and for each urban attraction, we obtain the isobenefit orography
of the city, namely a map of its urban attractions and of their flows. This is
a liquid surface rather than solid, as it varies across time and people. It is
in this liquidness where resides the complexity of cities, their bottom up
spirit and the dynamicity of equilibriums and networks. People do not
necessarily go in the most accessible points, but where they need and want to,
and, they flow through paths they need or choose to pass through. It is also
introduced the likeability of places and paths: in addition to the usual
parameters currently used, which weight distances in terms of physical
distance, cost, time or mental easiness representations, psycho-economical
distances used in the isobenefit lines proposed here, also consider how a place
and a path pleases us. According to the Underground Hedonic Theory, this
pleasure to pass through or to stay in agreeable areas has an underground and
an inertia effect too which contributes to delight our lives. The final purpose
of the science of cities and urban design is to understand cities and make them
efficient and attractive to please our lives in them.


title: Brauer-friendly modules and slash functors

abstract:
  This paper introduces the notion of Brauer-friendly modules, a generalisation
of endo-p-permutation modules. A module over a block algebra OGe is said to be
Brauer-friendly if it is a direct sum of indecomposable modules with compatible
fusion-stable endopermutation sources. We obtain, for these modules, a
functorial version of Dade's slash construction, also known as
deflation-restriction. We prove that our slash functors, defined over
Brauer-friendly categories, share most of the very useful properties that are
satisfied by the Brauer functor over the category of p-permutation OGe-modules.
In particular, we give a parametrisation of indecomposable Brauer-friendly
modules, which opens the way to a complete classification whenever the
fusion-stable sources are classified. Those tools have been used to prove the
existence of a stable equivalence between non-principal blocks in the context
of a minimal counter-example to the odd Z*p-theorem.


title: A reduced new modified Weibull distribution

abstract:
  In this paper, we propose a reduced version of the new modified Weibull (NMW)
distribution due to Almalki and Yuan \cite{meNMW} in order to avoid some
estimation problems. The number of parameters in the NMW distribution is five.
The number of parameters in the reduced version is three. We study mathematical
properties as well as maximum likelihood estimation of the reduced version.
Four real data sets (two of them complete and the other two censored) are used
to compare the flexibility of the reduced version versus the NMW distribution.
It is shown that the reduced version has the same desirable properties of the
NMW distribution in spite of having two less parameters. The NMW distribution
did not provide a significantly better fit than the reduced version for any of
the four data sets.


title:
Planar Ising magnetization field II. Properties of the critical and
  near-critical scaling limits

abstract:
  In [CGN12], we proved that the renormalized critical Ising magnetization
fields $\Phi^a:= a^{15/8} \sum_{x\in a\, \Z^2} \sigma_x \, \delta_x$ converge
as $a\to 0$ to a random distribution that we denoted by $\Phi^\infty$. The
purpose of this paper is to establish some fundamental properties satisfied by
this $\Phi^\infty$ and the near-critical fields $\Phi^{\infty,h}$. More
precisely, we obtain the following results. \bi [(i)] If $A\subset \C$ is a
smooth bounded domain and if $m=m_A := <{\Phi^\infty, 1_A}$ denotes the
limiting rescaled magnetization in $A$, then there is a constant $c=c_A>0$ such
that {equation*} \log \Pb{m > x} \underset{x\to \infty}{\sim} -c \;
x^{16}\,.{equation*} In particular, this provides an alternative proof that the
field $\Phi^\infty$ is non-Gaussian (another proof of this fact would use the
$n$-point correlation functions established in \cite{CHI} which do not satisfy
Wick's formula). [(ii)] The random variable $m=m_A$ has a smooth {\it density}
and one has more precisely the following bound on its Fourier transform:
$|\Eb{e^{i\,t m}} |\le e^{- \tilde{c}\, |t|^{16/15}}$. [(iii)] There exists a
one-parameter family $\Phi^{\infty,h}$ of near-critical scaling limits for the
magnetization field in the plane with vanishingly small external magnetic
field. \ei


title:
On the equivalence of lossy evolution and POVM generalized quantum
  measurements

abstract:
  Loss induced generalized measurements have been introduced years ago as a
mean to implement generalized quantum measurements (POVM). Here the original
idea is extended to a complete equivalence of lossy evolution and a certain
widely used class of POVM. This class includes POVM used for unambiguous state
discrimination and entanglement concentration. One implication of this
equivalence is that unambiguous state discrimination schemes based on
PT-symmetric and non-Hermitian Hamiltonians have the same performance as those
of standard POVM. After discussing several key points of this equivalence we
illustrate our findings in two elementary physical realizations. Finally, we
discuss several implications of this equivalence.


title: A combinatorial non-commutative Hopf algebra of graphs

abstract:
  A non-commutative, planar, Hopf algebra of rooted trees was proposed in L.
Foissy, Bull. Sci. Math. 126 (2002) 193-239. In this paper we propose such a
non-commutative Hopf algebra for graphs. In order to define a non-commutative
product we use a quantum field theoretical (QFT) idea, namely the one of
introducing discrete scales on each edge of the graph (which, within the QFT
framework, corresponds to energy scales of the associated propagators).


title: On three-dimensional Alexandrov spaces

abstract:
  We study three-dimensional Alexandrov spaces with a lower curvature bound,
focusing on extending three classical results on three-dimensional manifolds:
First, we show that a closed three-dimensional Alexandrov space of positive
curvature, with at least one topological singularity, must be homeomorphic to
the suspension of the real projective plane; we use this to classify, up to
homeomorphism, closed, positively curved Alexandrov spaces of dimension three.
Second, we classify closed three-dimensional Alexandrov spaces of nonnegative
curvature. Third, we study the well-known Poincar\'e Conjecture in dimension
three, in the context of Alexandrov spaces, in the two forms it is usually
formulated for manifolds. We first show that the only three-dimensional
Alexandrov space that is also a homotopy sphere is the 3-sphere; then we give
examples of closed, geometric, simply connected three-dimensional Alexandrov
spaces for five of the eight Thurston geometries, proving along the way the
impossibility of getting such examples for the Nil,
$\widetilde{\mathrm{SL}_2(\mathbb{R})}$ and Sol geometries. We conclude the
paper by proving the analogue of the geometrization conjecture for closed
three-dimensional Alexandrov spaces.


title: The Katowice problem and autohomeomorphisms of $\omega^*$

abstract:
  We show that the existence of a homeomorphism between $\omega_0^*$ and
$\omega_1^*$ entails the existence of a non-trivial autohomeomorphism of
$\omega_0^*$.


title: MAX 2-SAT with up to 108 qubits

abstract:
  We experimentally study the performance of a programmable quantum annealing
processor, the D-Wave One (DW1) with up to 108 qubits, on maximum
satisfiability problem with 2 variables per clause (MAX 2-SAT) problems. We
consider ensembles of random problems characterized by a fixed clause density,
an order parameter which we tune through its critical value in our experiments.
We demonstrate that the DW1 is sensitive to the critical value of the clause
density. The DW1 results are verified and compared with akmaxsat, an exact,
state-of-the-art algorithm. We study the relative performance of the two
solvers and how they correlate in terms of problem hardness. We find that the
DW1 performance scales more favorably with problem size and that problem
hardness correlation is essentially non-existent. We discuss the relevance and
limitations of such a comparison.


title:
Topotactic phase transformation of the brownmillerite SrCoO2.5 to the
  perovskite SrCoO3-\delta

abstract:
  Oxygen stoichiometry is one of the most important elements in determining the
physical properties of transition metal oxides (TMOs). A small fractional
change in the oxygen content, resulting in the variation of valence state of
the transition metal, can drastically modify the materials functionalities. In
particular, TMOs with mixed valences have attracted attention for many energy
applications. Previous studies also showed that the ability to control the
number of d-band electron populations and detailed spin configurations is
critical for improved catalytic performance of TMOs. In this context,
SrCoO$_{x}$ (2.5 < x < 3.0) is an ideal class of materials due to the existence
of two structurally distinct topotatic phases, i.e. the brownmillerite
SrCoO$_{2.5}$(BM-SCO) and the perovskite SrCoO$_{3}$. Especially, BM-SCO has
atomically-ordered one-dimensional vacancy channels, which can accommodate
additional oxygen. Moreover, SrCoO$_{x}$ exhibits a wide spectrum of physical
properties depending on the oxygen stoichiometry. Since SrCoOx has only a
single knob to control the Co valence state without cation doping, it is an
attractive material for studying the valence state dependent physical
properties. However, so far, the growth of high quality single crystalline
materials has not been much studied due to difficulty in controlling the right
oxidation state. In this work, we report on the epitaxial growth of BM-SCO
single crystalline films on SrTiO3 by pulsed laser epitaxy. In order to examine
the topotactic phase transformation to the perovskite SrCoO$_{3-\delta}$, some
of samples were subsequently in-situ annealed at various oxygen pressure
P(O$_{2}$). We found that post-annealing in high P(O$_{2}$) (> several hundreds
of Torr) could fill some of oxygen vacancies accompanying systematic evolution
in electronic, magnetic, and thermoelectric properties.


title: Unraveling gravity beyond Einstein with extended test bodies

abstract:
  The motion of test bodies in gravity is tightly linked to the conservation
laws. This well-known fact in the context of General Relativity is also valid
for gravitational theories which go beyond Einstein's theory. Here we derive
the equations of motion for test bodies for a very large class of gravitational
theories with a general nonminimal coupling to matter. These equations form the
basis for future systematic tests of alternative gravity theories. Our
treatment is covariant and generalizes the classic Mathisson-Papapetrou-Dixon
result for spinning (extended) test bodies. The equations of motion for
structureless test bodies turn out to be surprisingly simple, despite the very
general nature of the theories considered.


title:
Mass flow in the circumbinary disk with gap around supermassive binary
  black holes

abstract:
  In this paper, we study the interaction between the supermassive binary black
holes in elliptical orbit and their surrounding disk with a gap.
  The gap in the disk is a low density region formed due to the tidal effects
of the less massive black hole. The binary we have investigated has a
sub-parsec separation and is coplanar with the disk. We find that the maximum
variation of the surface density in the gap reaches 50% during an orbital
period. However, in other regions of the disk, the density variation is much
less than 1%. Furthermore, we calculate the corresponding variation of spectral
energy distribution within a period, but little variation is found. The reason
for these results is that the viscosity timescale of the disk at the binary
radius is much longer than the orbital period of the binary.


title: Mapping the differential reddening in globular clusters

abstract:
  We build differential-reddening maps for 66 Galactic globular clusters (GCs)
with archival HST WFC/ACS F606W and F814W photometry. Because of the different
GC sizes (characterised by the half-light radius $R_h$) and distances to the
Sun, the WFC/ACS field of view ($200\arcsec\times200\arcsec$) coverage
($R_{obs}$) lies in the range $1\la R_{obs}/R_h\la15$ for about 85% of the
sample, with about 10% covering only the inner ($R_{obs}\la R_h$) parts. We
divide the WFC/ACS field of view across each cluster in a regular cell grid,
and extract the stellar-density Hess diagram from each cell, shifting it in
colour and magnitude along the reddening vector until matching the mean
diagram. Thus, the maps correspond to the internal dispersion of the reddening
around the mean. Depending on the number of available stars (i.e. probable
members with adequate photometric errors), the angular resolution of the maps
range from $\approx7\arcsec\times7\arcsec$ to
$\approx20\arcsec\times20\arcsec$. We detect spatially-variable extinction in
the 66 globular clusters studied, with mean values ranging from
$\mEBV\approx0.018$ (NGC\,6981) up to $\mEBV\approx0.16$ (Palomar\,2).
Differential-reddening correction decreases the observed foreground reddening
and the apparent distance modulus but, since they are related to the same value
of \EBV, the distance to the Sun is conserved. Fits to the mean-ridge lines of
the highly-extincted and photometrically scattered globular cluster Palomar\,2
show that age and metallicity also remain unchanged after the
differential-reddening correction, but measurement uncertainties decrease
because of the reduced scatter. The lack of systematic variations of \mEBV\
with both the foreground reddening and the sampled cluster area indicates that
the main source of differential reddening is interstellar.


title:
Spectroscopy of fullerenes, fulleranes and PAHs in the UV, visible and
  near infrared spectral range

abstract:
  The spectra of fullerenes C60 and C70, higher fullerenes C76, C78 and C84 and
hydrogenated fullerenes (fulleranes) were studied in laboratory in the UV and
in the visible spectral range and could be used for searching and recognizing
these molecules in space. Furthermore, the radical cation spectra of all the
mentioned fullerene series and also of a series of large and very large
polycyclic aromatic hydrocarbons (PAHs) were generated in laboratory and
studied in the near infrared spectral range.


title: Gravitational theoretical development supporting MOND

abstract:
  Conformal geometry is considered within a general relativistic framework. An
invariant distant for proper time is defined and a parallel displacement is
applied in the distorted space-time, modifying Einstein's equation
appropriately. A particular solution is introduced for the covariant
acceleration potential that matches the observed velocity distribution at large
distances from the galactic centre, i.e. Modified Newtonian Dynamics (MOND).
This explicit solution, of a general framework that allows both curvature and
explicit local expansion of space-time, thus reproduces the observed flattening
of galaxys' rotation curves without the need to assume the existence of dark
matter. The large distance expansion rate is found to match the speed of a
spherical shock wave.


title: Extracting scaling laws from numerical dynamo models

abstract:
  Earth's magnetic field is generated by processes in the electrically
conducting, liquid outer core, subsumed under the term `geodynamo'. In the last
decades, great effort has been put into the numerical simulation of core
dynamics following from the magnetohydrodynamic (MHD) equations. However, the
numerical simulations are far from Earth's core in terms of several control
parameters. Different scaling analyses found simple scaling laws for quantities
like heat transport, flow velocity, magnetic field strength and magnetic
dissipation time.
  We use an extensive dataset of 116 numerical dynamo models compiled by
Christensen and co-workers to analyse these scalings from a rigorous model
selection point of view. Our method of choice is leave-one-out cross-validation
which rates models according to their predictive abilities. In contrast to
earlier results, we find that diffusive processes are not negligible for the
flow velocity and magnetic field strength in the numerical dynamos. Also the
scaling of the magnetic dissipation time turns out to be more complex than
previously suggested. Assuming that the processes relevant in the numerical
models are the same as in Earth's core, we use this scaling to estimate an
Ohmic dissipation of 3-8 TW for the core. This appears to be consistent with
recent high CMB heat flux scenarios.


title:
Radiation reaction force induced nonlinear mixing of Raman sidebands of
  an ultra-intense laser pulse in a plasma

abstract:
  Stimulated Raman scattering of an ultra-intense laser pulse in plasmas is
studied by perturbatively including the leading order term of the
Landau-Lifshitz radiation reaction force in the equation of motion for plasma
electrons. In this approximation, radiation reaction force causes phase shift
in nonlinear current densities that drive the two Raman sidebands (anti-Stokes
and Stokes waves), manifesting itself into the nonlinear mixing of two
sidebands. This mixing results in a strong enhancement in the growth of the
forward Raman scattering instability.


title:
Large-scale MU-MIMO: It Is Necessary to Deploy Extra Antennas at Base
  Station

abstract:
  In this paper, the large-scale MU-MIMO system is considered where a base
station (BS) with extremely large number of antennas (N) serves relatively less
number of users (K). In order to achieve largest sum rate, it is proven that
the amount of users must be limited such that the number of antennas at the BS
is preponderant over that of the antennas at all the users. In other words, the
antennas at the BS should be excess. The extra antennas at the BS are no longer
just an optional approach to enhance the system performance but the
prerequisite to the largest sum rate. Based on this factor, for a fixed N, the
optimal K that maximizes the sum rate is further obtained. Additionally, it is
also pointed out that the sum rate can be substantially improved by only adding
a few antennas at the BS when the system is N=KM with M denoting the antennas
at each user. The derivations are under the assumption of N and M going to
infinity, and being implemented on different precoders. Numerical simulations
verify the tightness and accuracy of our asymptotic results even for small N
and M.


title: Reinforcement and inference in cross-situational word learning

abstract:
  Cross-situational word learning is based on the notion that a learner can
determine the referent of a word by finding something in common across many
observed uses of that word. Here we propose an adaptive learning algorithm that
contains a parameter that controls the strength of the reinforcement applied to
associations between concurrent words and referents, and a parameter that
regulates inference, which includes built-in biases, such as mutual
exclusivity, and information of past learning events. By adjusting these
parameters so that the model predictions agree with data from representative
experiments on cross-situational word learning, we were able to explain the
learning strategies adopted by the participants of those experiments in terms
of a trade-off between reinforcement and inference. These strategies can vary
wildly depending on the conditions of the experiments. For instance, for fast
mapping experiments (i.e., the correct referent could, in principle, be
inferred in a single observation) inference is prevalent, whereas for
segregated contextual diversity experiments (i.e., the referents are separated
in groups and are exhibited with members of their groups only) reinforcement is
predominant. Other experiments are explained with more balanced doses of
reinforcement and inference.


title:
Regularity of Wiener functionals under a H\"ormander type condition of
  order one

abstract:
  We study the local existence and regularity of the density of the law of a
functional on the Wiener space which satisfies a criterion that generalizes the
H\"ormander condition of order one (that is, involving the first order Lie
brackets) for diffusion processes.


title: Coarse amenability and discreteness

abstract:
  This paper is devoted to dualization of paracompactness to the coarse
category via the concept of $R$-disjointness. Property A of G.Yu can be seen as
a coarse variant of amenability via partitions of unity and leads to a
dualization of paracompactness via partitions of unity. On the other hand,
finite decomposition complexity of G.Yu and straight finite decomposition
complexity of Dranishnikov-Zarichnyi employ $R$-disjointness as the main
concept. We generalize both concepts to that of countable asymptotic dimension
and our main result shows that it is a subclass of of spaces with Property A.
In addition, it gives a necessary and sufficient condition for spaces of
countable asymptotic dimension to be of finite asymptotic dimension.


title: Possible evidence for a $5.86 PeV$ cosmic ray enhancement

abstract:
  A blind search has been made for cosmic ray sources of neutral hadrons
yielding a peak just above the knee, which has resulted in possible evidence
for a peak at $5.86\pm 0.75 PeV.$ This search was motivated by a 1999 claim by
this author of such a peak at $4.5\pm 2.2 PeV,$ and also some recent results by
at least three experiments showing a $E\approx 5.6 PeV$ peak in the
all-particle cosmic ray spectrum.


title:
Notes on the sum and maximum of independent exponentially distributed
  random variables with different scale parameters

abstract:
  We consider the distribution of the sum and the maximum of a collection of
independent exponentially distributed random variables. The focus is laid on
the explicit form of the density functions (pdf) of non-i.i.d. sequences. Those
are recovered in a simple and direct way based on conditioning. A connection
between the pdf and a representation of the convolution characteristic function
as a linear combination of the single characteristic functions is drawn. It is
demonstrated how the results on the pdf of order statistics and the convolution
merge.


title: On the Cause of Supra-Arcade Downflows in Solar Flares

abstract:
  A model of supra-arcade downflows (SADs), dark low density regions also known
as tadpoles that propagate sunward during solar flares, is presented. It is
argued that the regions of low density are flow channels carved by
sunward-directed outflow jets from reconnection. The solar corona is
stratified, so the flare site is populated by a lower density plasma than that
in the underlying arcade. As the jets penetrate the arcade, they carve out
regions of depleted plasma density which appear as SADs. The present
interpretation differs from previous models in that reconnection is localized
in space but not in time. Reconnection is continuous in time to explain why
SADs are not filled in from behind as they would if they were caused by
isolated descending flux tubes or the wakes behind them due to temporally
bursty reconnection. Reconnection is localized in space because outflow jets in
standard two-dimensional reconnection models expand in the normal (inflow)
direction with distance from the reconnection site, which would not produce
thin SADs as seen in observations. On the contrary, outflow jets in spatially
localized three-dimensional reconnection with an out-of-plane (guide) magnetic
field expand primarily in the out-of-plane direction and remain collimated in
the normal direction, which is consistent with observed SADs being thin.
Two-dimensional proof-of-principle simulations of reconnection with an
out-of-plane (guide) magnetic field confirm the creation of SAD-like depletion
regions and the necessity of density stratification. Three-dimensional
simulations confirm that localized reconnection remains collimated.


title: Rip Brane Cosmology from 4d Inhomogeneous Dark Fluid Universe

abstract:
  Specific dark energy models with linear inhomogeneous time-dependent equation
of state, within the framework of 4d Friedman-Robertson-Walker (FRW) cosmology,
are investigated. It is demonstrated that the choice of such 4d inhomogeneous
fluid models may lead to a brane FRW cosmology without any explicit account of
higher dimensions at all. Effectively, we thus obtain a brane dark energy
universe without introducing the brane concept explicitly. Several examples of
brane Rip cosmology arising from 4d inhomogeneous dark fluid models are given.


title:
Implications of LHC data on 125GeV Higgs-like boson for the Standard
  Model and its various extensions

abstract:
  Recent data on 125 GeV Higgs-like boson at the LHC starts to constrain the
electroweak symmetry breaking sector of the SM and its various extensions. If
one imposes the local gauge symmetry of the Standard Model (SM) ($SU(3)_c
\times SU(2)_L \times U(1)_Y$) to the SM and any possible new physics
scenarios, the SM Higgs properties will be modified by intrinsically two
different ways: by new physics either coupling directly to the SM Higgs boson
$h$, or affecting indirectly the SM Higgs properties through the mixing of $h$
with a SM singlet scalar $s$. The models of two Higgs doublet, extra sequential
and mirror fermions belong to the first category, whereas the models with a
hidden sector dark matter, extra vector-like fermions and new charged vector
bosons, which can enhance the diphoton rate of the SM Higgs-like resonance,
belong to the second category. We perform a global fit to data in terms of the
effective Lagrangian description of two interaction eigenstates of scalar
bosons, a SM Higgs and a singlet scalar, and their mixing. This framework is
more suitable to study singlet-extended scenarios discussed above compared to
other approaches based on the Lagrangian of mass eigenstates. With fairly
model-independent assumptions, the effective Lagrangian contains at most four
free parameters still encompassing the majority of models in the literature.
Interestingly, the SM gives the best fit if all data from ATLAS and CMS are
used, whereas various singlet extensions can fit better to individual ATLAS or
CMS data. Without further assumptions, an upper bound on the total width (or,
non-standard branching ratio) is generically obtained. Furthermore, global fit
based on our parameterization can be used to probe interactions of the singlet
scalar if the singlet resides below $2m_W$.


title: On Soft Power Diagrams

abstract:
  Many applications in data analysis begin with a set of points in a Euclidean
space that is partitioned into clusters. Common tasks then are to devise a
classifier deciding which of the clusters a new point is associated to, finding
outliers with respect to the clusters, or identifying the type of clustering
used for the partition.
  One of the common kinds of clusterings are (balanced) least-squares
assignments with respect to a given set of sites. For these, there is a
'separating power diagram' for which each cluster lies in its own cell.
  In the present paper, we aim for efficient algorithms for outlier detection
and the computation of thresholds that measure how similar a clustering is to a
least-squares assignment for fixed sites. For this purpose, we devise a new
model for the computation of a 'soft power diagram', which allows a soft
separation of the clusters with 'point counting properties'; e.g. we are able
to prescribe how many points we want to classify as outliers.
  As our results hold for a more general non-convex model of free sites, we
describe it and our proofs in this more general way. Its locally optimal
solutions satisfy the aforementioned point counting properties. For our target
applications that use fixed sites, our algorithms are efficiently solvable to
global optimality by linear programming.


title: Configurational entropy of ice from thermodynamic integration

abstract:
  The configurational entropy of ice is calculated by thermodynamic integration
from high to low temperatures. We use Monte Carlo simulations with a simple
energy model which reproduces the Bernal-Fowler ice rules. This procedure is
found to be precise enough to give reliable values for the residual entropy
s_th of different ice phases in the thermodynamic limit. First, we check it for
a two-dimensional ice model. Second, we calculate s_th for ice Ih, and compare
our result with those previously given in the literature. Third, we obtain s_th
for ice VI, for which we find a value clearly higher than for ice Ih.


title: Determinacy and indeterminacy of games played on complete metric spaces

abstract:
  Schmidt's game is a powerful tool for studying properties of certain sets
which arise in Diophantine approximation theory, number theory, and dynamics.
Recently, many new results have been proven using this game. In this paper we
address determinacy and indeterminacy questions regarding Schmidt's game and
its variations, as well as more general games played on complete metric spaces
(e.g. fractals). We show that except for certain exceptional cases, these games
are undetermined on Bernstein sets.


title:
Fast optical cooling of nanomechanical cantilever with the dynamical
  Zeeman effect

abstract:
  We propose an efficient optical electromagnetically induced transparency
(EIT) cooling scheme for a cantilever with a nitrogen-vacancy center attached
in a non-uniform magnetic field using dynamical Zeeman effect. In our scheme,
the Zeeman effect combined with the quantum interference effect enhances the
desired cooling transition and suppresses the undesired heating transitions. As
a result, the cantilever can be cooled down to nearly the vibrational ground
state under realistic experimental conditions within a short time. This
efficient optical EIT cooling scheme can be reduced to the typical EIT cooling
scheme under special conditions.


title: Hierarchy and dynamics of trace distance correlations

abstract:
  We define and analyze measures of correlations for bipartite states based on
trace distance. For Bell diagonal states of two qubits, in addition to the
known expression for quantum correlations using this metric, we provide
analytic expressions for the classical and total correlations. The ensuing
hierarchy of correlations based on trace distance is compared to the ones based
on relative entropy and Hilbert-Schmidt norm. Although some common features can
be found, the trace distance measure is shown to differentiate from the others
in that the closest uncorrelated state to a given bipartite quantum state is
not given by the product of the marginals, and further, the total correlations
are strictly smaller than the sum of the quantum and classical correlations. We
compare the various correlation measures in two dynamical non-Markovian models,
locally applied phase-flip channels and random external fields. It is shown
that the freezing behavior, observed across all known valid measures of quantum
correlations for Bell diagonal states under local phase-flip channels, occurs
for a larger set of starting states for the trace distance than for the other
metrics.

categories: quant-ph cond-mat.stat-mech math-ph math.MP physics.data-an


title: Echoes of multiple outbursts of Sagittarius A* revealed by Chandra

abstract:
  The relatively rapid spatial and temporal variability of the X-ray radiation
from some molecular clouds near the Galactic center shows that this emission
component is due to the reflection of X-rays generated by a source that was
luminous in the past, most likely the central supermassive black hole,
Sagittarius A*. Studying the evolution of the molecular cloud reflection
features is therefore a key element to reconstruct Sgr A*'s past activity. The
aim of the present work is to study this emission on small angular scales in
order to characterize the source outburst on short time scales. We use Chandra
high-resolution data collected from 1999 to 2011 to study the most rapid
variations detected so far, those of clouds between 5' and 20' from Sgr A*
towards positive longitudes. Our systematic spectral-imaging analysis of the
reflection emission, notably of the Fe Kalpha line at 6.4 keV and its
associated 4-8 keV continuum, allows us to characterize the variations down to
15" angular scale and 1-year time scale. We reveal for the first time abrupt
variations of few years only and in particular a short peaked emission, with a
factor of 10 increase followed by a comparable decrease, that propagates along
the dense filaments of the Bridge cloud. This 2-year peaked feature contrasts
with the slower 10-year linear variations we reveal in all the other molecular
structures of the region. Based on column density constraints, we argue that
these two different behaviors are unlikely to be due to the same illuminating
event. The variations are likely due to a highly variable active phase of Sgr
A* sometime within the past few hundred years, characterized by at least two
luminous outbursts of a few-year time scale and during which the Sgr A*
luminosity went up to at least 10^39 erg/s.


title:
A permutation invariant collective variable to track and drive vacancy
  dynamics in simulations of solids

abstract:
  Vacancy dynamics in oxides are vital for understanding redox reactions and
resulting memristive effects or catalytic activity. We present a method to
track and drive vacancies which we apply to metadynamics simulation of oxygen
vacancies (V$_{\mathrm{O}}$) in rutile, demonstrating its effectiveness. Using
the density functional based tight binding method, it is possible to explore
the free energy hyperplane of oxygen vacancies in TiO$_{2}$. We show that the
migration of V$_{\mathrm{O}}$ in TiO$_{2}$ is governed by the jump with the
higherst number of realizations. Free energy profiles are consistent with
minimum energy paths.


title: The Pierre Auger Observatory: results on the highest energy particles

abstract:
  The Pierre Auger Observatory has been designed to investigate the most
energetic particles known, the ultra high energy cosmic rays. The observatory,
covering an area of 3000 km^2, combines two different detection techniques to
study the huge particle showers created by the interaction of primary cosmic
rays with the atmosphere. The analysis of the showers allows one to extract
information on the nature of the primary cosmic rays, as well as their origin.
Moreover, the study of the interaction of these particles with the atmosphere
offers a unique window to study particle physics at an energy more than one
order of magnitude above the current highest energy human-made accelerator. In
this contribution selected results are presented, with a focus on the primary
mass composition, the determination of the number of muons, which is sensitive
to the shower hadronic interactions, and the measurement of the proton-air
cross-section at sqrt(s) = 57 TeV. For the last topic, a link with the
proton-proton cross-section measurements using accelerators will be made.
Results on the cosmic ray energy spectrum and on searches for ultra high energy
photons and neutrinos, will also be discussed.


title:
Strong binding and shrinkage of single and double kbar~nuclear systems
  (K^-pp, K^-ppn, K^-K^-p and K^-K^-pp) predicted by Faddeev-Yakubovsky
  calculations

abstract:
  Non-relativistic Faddeev and Faddeev-Yakubovsky calculations were made for
K^-pp, K^- ppn, K^-K^-p and K^- K^-pp kaonic nuclear clusters, where the quasi
bound states were treated as bound states by employing real separable potential
models for the K^ - - K^ - and the K^ - -nucleon interactions as well as for
the nucleon-nucleon interaction. The binding energies and spatial shrinkages of
these states, obtained for various values of the Kbar N interaction, were found
to increase rapidly with the Kbar N interaction strength. Their behaviors are
shown in a reference diagram, where possible changes by varying the KbarN
interaction in the dense nuclear medium are given. Using the Lambda(1405)
ansatz with a PDG mass of 1405 MeV/ c^2 for K^-p, the following ground-state
binding energies together with the wave functions were obtained: 51.5 MeV ( K^
- pp ), 69 MeV ( K^ - ppn), 30.4 MeV ( K^ - K^ - p ) and 93 MeV ( K^ -K^ - pp
), which are in good agreement with previous results of variational calculation
based on the Akaishi-Yamazaki coupled-channel potential. The K^ - K^ - pp state
has a significantly increased density where the two nucleons are located very
close to each other, in spite of the inner NN repulsion. Relativistic
corrections on the calculated non-relativistic results indicate substantial
lowering of the bound-state masses, especially of K^-K^-pp , toward the kaon
condensation regime. The fact that the recently observed binding energy of
K^-pp is much larger (by a factor of 2) than the originally predicted one may
infer an enhancement of the KbarN interaction in dense nuclei by about 25 %,
possibly due to chiral symmetry restoration. In this respect some qualitative
accounts are given based on "clearing QCD vacuum" model of Brown, Kubodera and
Rho.


title: Spectroscopic study of interfaces in Al/Ni periodic multilayers

abstract:
  Using electron-induced X-ray emission spectroscopy (XES), we have studied two
Al/Ni periodic multilayers that differ only by their annealing temperature:
as-deposited and annealed at 115C. Our aim is to show that XES can provide
further details about the chemistry at the metal-metal interface, in addition
to what is obtained by X-ray diffraction. The distribution of valence states
exhibiting Al 3p and Ni 3d character is determined from the analysis of the Al
Kbeta and Ni Lalpha emission bands respectively. The multilayer emission bands
are compared to those of reference materials: pure Al and Ni metals as well as
Al3Ni, Al3Ni2 and AlNi intermetallics. We provide evidence that, for
temperatures up to 115C, Al3Ni is the major component of the multilayer.


title: Characterization of Al and Mg Alloys from Their X-Ray Emission Bands

abstract:
  The valence states of Mg-Al alloys are compared to those of reference
materials (pure Mg and Al metals, and intermetallics). Two methods based on
X-ray emission spectroscopy are proposed to determine the phases and their
proportion: first, by analyzing the Al valence spectra of the Mg-rich alloys
and the Mg valence spectra of the Al-rich alloys; second, by fitting with a
linear combination of the reference spectra the Al spectra of the Al-rich
alloys and the Mg spectra of the Mg-rich alloys. This enables us to determine
that Al and Al3Mg2 are present in the 0-43.9 wt% Al composition range and Mg
and Al12Mg17 are present in the 62.5-100 wt% Al composition range. In the
43.9-62.5% Al range, the alloy is single phase and an underestimation of the Al
content of the alloy can be estimated from the comparison of the bandwidth of
the alloy spectrum to the bandwidths of the reference spectra.


title:
Complete spectrum and scalar products for the open spin-1/2 XXZ quantum
  chains with non-diagonal boundary terms

abstract:
  We use the quantum separation of variable (SOV) method to construct the
eigenstates of the open XXZ chain with the most general boundary terms. The
eigenstates in the inhomogeneous case are constructed in terms of solutions of
a system of quadratic equations. This SOV representation permits us to compute
scalar products and can be used to calculate form factors and correlation
functions.

categories: math-ph cond-mat.stat-mech hep-th math.MP nlin.SI


title:
Folding Kinetics of Riboswitch Transcriptional Terminators and
  Sequesterers

abstract:
  To function as gene regulatory elements in response to environmental signals,
riboswitches must adopt specific secondary structures on appropriate time
scales. We employ kinetic Monte Carlo simulation to model the time-dependent
folding during transcription of TPP riboswitch expression platforms. According
to our simulations, riboswitch transcriptional terminators, which must adopt a
specific hairpin configuration by the time they have been transcribed, fold
with higher efficiency than Shine-Dalgarno sequesterers, whose proper structure
is required only at the time of ribosomal binding. Our findings suggest both
that riboswitch transcriptional terminator sequences have been naturally
selected for high folding efficiency, and that sequesterers can maintain their
function even in the presence of significant misfolding.


title: Exploring Quantum Physics at the ILC

abstract:
  We review the ILC capabilities to explore the electroweak (EW) sector of the
SM at high precision and the prospects of unveiling signals of BSM physics,
either through the presence of new particles in higher-order corrections or via
direct production of extra EW gauge bosons. This includes electroweak precision
observables, global fits to the SM Higgs boson mass as well as triple and
quartic gauge boson couplings.


title:
On the survival of a class of subcritical branching processes in random
  environment

abstract:
  Let $Z_{n}$ be the number of individuals in a subcritical BPRE evolving in
the environment generated by iid probability distributions. Let $X$ be the
logarithm of the expected offspring size per individual given the environment.
Assuming that the density of $X$ has the form $$p_{X}(x)=x^{-\beta
-1}l_{0}(x)e^{-\rho x}$$ for some $\beta >2,$ a slowly varying function
$l_{0}(x)$ and $\rho \in \left( 0,1\right),$ we find the asymptotic survival
probability and prove a Yaglom type conditional limit theorem for the process.
The survival probability decreases exponentially with an additional polynomial
term related to the tail of $X$. The proof relies on a fine study of a random
walk (with negative drift and heavy tails) conditioned to stay positive until
time $n$ and to have a small positive value at time $n$, with $n$ tending to
infinity.


title: Learning Markov networks with context-specific independences

abstract:
  Learning the Markov network structure from data is a problem that has
received considerable attention in machine learning, and in many other
application fields. This work focuses on a particular approach for this purpose
called independence-based learning. Such approach guarantees the learning of
the correct structure efficiently, whenever data is sufficient for representing
the underlying distribution. However, an important issue of such approach is
that the learned structures are encoded in an undirected graph. The problem
with graphs is that they cannot encode some types of independence relations,
such as the context-specific independences. They are a particular case of
conditional independences that is true only for a certain assignment of its
conditioning set, in contrast to conditional independences that must hold for
all its assignments. In this work we present CSPC, an independence-based
algorithm for learning structures that encode context-specific independences,
and encoding them in a log-linear model, instead of a graph. The central idea
of CSPC is combining the theoretical guarantees provided by the
independence-based approach with the benefits of representing complex
structures by using features in a log-linear model. We present experiments in a
synthetic case, showing that CSPC is more accurate than the state-of-the-art IB
algorithms when the underlying distribution contains CSIs.


title: The Hyperbolic Ax-Lindemann-Weierstrass conjecture

abstract:
  The hyperbolic Ax-Lindemann-Weierstrass conjecture is a functional algebraic
independence statement for the uniformizing map of an arithmetic variety. In
this paper we provide a proof of this conjecture, generalizing previous work of
Pila-Tsimerman and Peterzil-Starchenko.


title:
Cobalt spin state above the valence and spin-state transition in
  (Pr0.7Sm0.3)0.7Ca0.3CoO3

abstract:
  (Pr0.7Sm0.3)0.7Ca0.3CoO3 belongs to a class of cobalt oxides undergoing a
first-order transition (T* close to 90 K) associated to a coupled change in the
valence and spin-state degrees of freedom. The Curie-Weiss regime present
around room temperature (T >> T*) was analysed in detail to address the
controversial issue of the cobalt spin states above the transition. This
magnetic investigation indicates that the Co4+ are in an intermediate
spin-state, while the Co3+ are in a mixed state combining low-spin and
high-spin states. These results are discussed with respect to the literature on
related compounds and recent results of x-ray absorption spectroscopy.


title:
Development of a relativistic coupled-cluster method for one electron
  detachment theory: Application to Mn IX, Fe X, Co XI and Ni XII ions

abstract:
  We have developed one electron detachment theory from a closed-shell atomic
configuration in the relativistic Fock-space coupled-cluster ansatz. Using this
method, we determine sensitivity coefficients to the variation of the fine
structure constant in the first three important low-lying transitions of the
astrophysically interesting highly charged Mn IX, Fe X, Co XI and Ni XII ions.
The potential of this method has been assessed by evaluating the detachment
energies of the removed electrons and determining lifetimes of the atomic
states in the above ions. To account the sensitivity of the higher order
relativistic effects, we have used the four component wave functions of the
Dirac-Coulomb-Breit Hamiltonian with the leading order quantum electrodynamics
(QED) corrections. A systematic study has been carried out to highlight the
importance of the Breit and QED interactions in the considered properties of
the above ions.


title:
Lagrangian submanifolds in complex space forms satisfying an improved
  equality involving $\delta(2,2)$

abstract:
  It was proved in [8,9] that every Lagrangian submanifold $M$ of a complex
space form $\tilde M^{5}(4c)$ of constant holomorphic sectional curvature $4c$
satisfies the following optimal inequality: {align}\tag{A}\delta(2,2)\leq
\text{\small${25}{4}$} H^{2}+8c,{align} where $H^{2}$ is the squared mean
curvature and $\delta(2,2)$ is a $\delta$-invariant on $M$ introduced by the
first author. This optimal inequality improves a special case of an earlier
inequality obtained in [B.-Y. Chen, Japan. J. Math. 26 (2000), 105-127].
  The main purpose of this paper is to classify Lagrangian submanifolds of
$\tilde M^{5}(4c)$ satisfying the equality case of the improved inequality (A).


title:
Classification of minimal Lorentz surfaces in indefinite space forms
  with arbitrary codimension and arbitrary index

abstract:
  Since J. L. Lagrange initiated in 1760 the study of minimal surfaces of
Euclidean 3-space, minimal surfaces in real space forms have been studied
extensively by many mathematicians during the last two and half centuries. In
contrast, so far very few results on minimal Lorentz surfaces in indefinite
space forms are known. Hence, in this paper we investigate minimal Lorentz
surfaces in arbitrary indefinite space forms. As a consequence, we obtain
several classification results for minimal Lorentz surfaces in indefinite space
forms. In particular, we completely classify all minimal Lorentz surfaces in a
pseudo-Euclidean space $\mathbb E^m_s$ with arbitrary dimension $m$ and
arbitrary index $s$.


title: Invariances in Physics and Group Theory

abstract:
  This is a short review of the heritage of Klein's Erlangen program in modern
physics.


title:
Dependence of the Gauss-Codazzi equations and the Ricci equation of
  Lorentz surfaces

abstract:
  The fundamental equations of Gauss, Codazzi and Ricci provide the conditions
for local isometric embeddability. In general, the three fundamental equations
are independent for surfaces in Riemannian 4-manifolds. In contrast, we prove
in this article that for arbitrary Lorentz surfaces in Lorentzian Kaehler
surfaces the equation of Ricci is a consequence of the equations of Gauss and
Codazzi.


title: Minimal flat Lorentzian surfaces in Lorentzian complex space forms

abstract:
  In this article we study minimal flat Lorentzian surfaces in Lorentzian
complex space forms. First we prove that, for minimal flat Lorentzian surfaces
in a Lorentzian complex form, the equation of Ricci is a consequence of the
equations of Gauss and Codazzi. Then we classify minimal flat Lorentzian
surfaces in the Lorentzian complex plane ${\bf C}^2_1$. Finally, we classify
minimal flat slant surfaces in Lorentzian complex projective plane $CP^2_1$ and
in Lorentzian complex hyperbolic plane $CH^2_1$.


title:
Geometry of quasi-sum production functions with constant elasticity of
  substitution property

abstract:
  A production function $f$ is called quasi-sum if there are strict monotone
functions $F, h_1,...,h_n$ with $F'>0$ such that $$f(x)= F(h_1 (x_1)+...+h_n
(x_n)).$$ The justification for studying quasi-sum production functions is that
these functions appear as solutions of the general bisymmetry equation and they
are related to the problem of consistent aggregation.
  In this article, first we present the classification of quasi-sum production
functions satisfying the constant elasticity of substitution property. Then we
prove that if a quasi-sum production function satisfies the constant elasticity
of substitution property, then its graph has vanishing Gauss-Kronecker
curvature (or its graph is a flat space) if and only if the production function
is either a linearly homogeneous generalized ACMS function or a linearly
homogeneous generalized Cobb-Douglas function.


title:
Construction of Hamiltonian-stationary Lagrangian submanifolds of
  constant curvature $\varepsilon$ in complex space forms $\tilde
  M^n(4\varepsilon)

abstract:
  Lagrangian submanifolds of a Kaehler manifold are called
Hamiltonian-stationary (or $H$-stationary for short) if it is a critical point
of the area functional restricted to compactly supported Hamiltonian
variations. In [B. Y. Chen, F. Dillen, L. Verstraelen and L. Vrancken,
Lagrangian isometric immersions of a real-space-form $M^{n}(c)$ into a
complex-space-form $\tilde{M}^{n}(4c)$, Math. Proc. Cambridge Philo. Soc. 124
(1998), 107-125], an effective method to constructing Lagrangian submanifolds
of constant curvature $\varepsilon$ in complex space form $M^n(4\varepsilon)$
was introduced. In this article we survey recent results on construction of
Hamiltonian-stationary Lagrangian submanifolds in complex space forms using
this method.


title: Some Improvements to Total Degree Tests

abstract:
  A low-degree test is a collection of simple, local rules for checking the
proximity of an arbitrary function to a low-degree polynomial. Each rule
depends on the function's values at a small number of places. If a function
satisfies many rules then it is close to a low-degree polynomial. Low-degree
tests play an important role in the development of probabilistically checkable
proofs.
  In this paper we present two improvements to the efficiency of low-degree
tests. Our first improvement concerns the smallest field size over which a
low-degree test can work. We show how to test that a function is a degree $d$
polynomial over prime fields of size only $d+2$.
  Our second improvement shows a better efficiency of the low-degree test of
Rubinfeld and Sudan (Proc. SODA 1992) than previously known. We show concrete
applications of this improvement via the notion of "locally checkable codes".
This improvement translates into better tradeoffs on the size versus probe
complexity of probabilistically checkable proofs than previously known.


title:
Single-tape and Multi-tape Turing machines through the lens of the
  Grossone methodology

abstract:
  The paper investigates how the mathematical languages used to describe and to
observe automatic computations influence the accuracy of the obtained results.
In particular, we focus our attention on Single and Multi-tape Turing machines
which are described and observed through the lens of a new mathematical
language which is strongly based on three methodological ideas borrowed from
Physics and applied to Mathematics, namely: the distinction between the object
(we speak here about a mathematical object) of an observation and the
instrument used for this observation; interrelations holding between the object
and the tool used for the observation; the accuracy of the observation
determined by the tool. Results of the observation executed by the traditional
and new languages are compared and discussed.


title: Compositions of birational endomorphisms of the affine plane

abstract:
  Let A^2 denote the affine plane over an algebraically closed field of
arbitrary characteristic. Besides contributing several new results in the
general theory of birational endomorphisms of A^2, this article describes
certain classes of birational endomorphisms f defined by requiring that the
missing curves or contracting curves of f are lines. The last part of the
article is concerned with the monoid structure of the set of birational
endomorphisms of A^2.


title: The last word(s) on CPOD 2013

abstract:
  Higher order moments of net conserved charge fluctuations, in particular net
baryon number and net electric charge, are sensitive thermodynamic observables
that respond strongly to critical behavior in strong interaction matter. In
order to use them also as a sensible probe to detect critical behavior in heavy
ion experiments we not only need to better understand the relation between
chemical freeze-out in heavy ion collision and the QCD phase boundary, we also
need to verify that charge fluctuations measured experimentally indeed
correspond to thermal conditions as described by equilibrium QCD. This requires
a model independent characterization of thermal conditions for which cumulants
of conserved charge fluctuations themselves are ideally suited.


title: Self-organized defect strings in two-dimensional crystals

abstract:
  Using experiments with single particle resolution and computer simulations we
study the collective behaviour of multiple vacancies injected into
two-dimensional crystals. We find that the defects assemble into linear strings
that propagate through the crystal in a succession of rapid one-dimensional
gliding phases and rare rotations, during which the direction of motion
changes. At both ends, strings are terminated by dislocations with
anti-parallel Burgers vectors. By monitoring the separation of the
dislocations, we measure their effective interactions with high precision, for
the first time beyond spontaneous formation and annihilation, and explain the
double-well form of the dislocation interaction in terms of continuum
elasticity theory. Our results give a detailed picture of the motion and
interaction of dislocations in two dimensions and enhance our understanding of
topological defects in two-dimensional nano-materials.


title:
Improved surface quality of anisotropically etched silicon {111} planes
  for mm-scale integrated optics

abstract:
  We have studied the surface quality of millimeter-scale optical mirrors
produced by etching CZ and FZ silicon wafers in potassium hydroxide to expose
the $\{111\}$ planes. We find that the FZ surfaces have four times lower noise
power at spatial frequencies up to $500\, {mm}^{-1}$. We conclude that mirrors
made using FZ wafers have higher optical quality.


title:
Existence and orbital stability of the ground states with prescribed
  mass for the L^2-critical and supercritical NLS on bounded domains

abstract:
  We study solutions of a semilinear elliptic equation with prescribed mass and
Dirichlet homogeneous boundary conditions in the unitary ball. Such problem
arises in the search of solitary wave solutions for nonlinear Schr\"odinger
equations (NLS) with Sobolev subcritical power nonlinearity on bounded domains.
Necessary and sufficient conditions are provided for the existence of such
solutions. Moreover, we show that standing waves associated to least energy
solutions are always orbitally stable when the nonlinearity is L^2-critical and
subcritical, while they are almost always stable in the L^2-supercritical
regime. The proofs are obtained in connection with the study of a variational
problem with two constraints, of independent interest: to maximize the
L^{p+1}-norm among functions having prescribed L^2 and H^1_0-norm.


title: Political Stability and Military Intervention in Egypt

abstract:
  Policy choices in the wake of recent mass protests in Egypt will determine
the likelihood of civil war in the short run and the prospects for democracy in
the long run. Economic conditions can be improved by international action to
reduce grain-based biofuel production and finance employment generation.
Creating the conditions for stable democracy requires accepting power-sharing
mechanisms in which the military will have an important role.


title:
The asymptotic number of integral cubic polynomials with bounded heights
  and discriminants

abstract:
  In the paper we partially solved the problem of the distribution of the
discriminants of integral polynomials in the cubic case. We proved the
asymptotic formula for the number of integral cubic polynomials having bounded
height and bounded discriminant. The main term of the obtained formula is the
best possible for the considered range of polynomial discriminant values.


title: The classical limit of a physical theory and the dimensionality of space

abstract:
  In the operational approach to general probabilistic theories one
distinguishes two spaces, the state space of the "elementary systems" and the
physical space in which "laboratory devices" are embedded. Each of those spaces
has its own dimension- the minimal number of real parameters (coordinates)
needed to specify the state of system or a point within the physical space.
Within an operational framework to a physical theory, the two dimensions
coincide in a natural way under the following "closeness" requirement: the
dynamics of a single elementary system can be generated by the invariant
interaction between the system and the "macroscopic transformation device" that
itself is described from within the theory in the macroscopic (classical)
limit. Quantum mechanics fulfils this requirement since an arbitrary unitary
transformation of an elementary system (spin-1/2 or qubit) can be generated by
the pairwise invariant interaction between the spin and the constituents of a
large coherent state ("classical magnetic field"). Both the spin state space
and the "classical field" are then embedded in the Euclidean three-dimensional
space. Can we have a general probabilistic theory, other than quantum theory,
in which the elementary system ("generalized spin") and the "classical fields"
generating its dynamics are embedded in a higher-dimensional physical space? We
show that as long as the interaction is pairwise, this is impossible, and
quantum mechanics and the three-dimensional space remain the only solution.
However, having multi-particle interactions and a generalized notion of
"classical field" may open up such a possibility.


title:
Generalized Bootstrap Equations and possible implications for the NLO
  Odderon

abstract:
  We formulate and discuss generalized bootstrap equations in nonabelian gauge
theories. They are shown to hold in the leading logarithmic approximation.
Since their validity is related to the self-consistency of the Steinmann
relations for inelastic production amplitudes they can be expected to be valid
also in NLO. Specializing to the N=4 SYM, we show that the validity in NLO of
these generalized bootstrap equations allows to find the NLO Odderon solution
with intercept exactly at one, a result which is valid also for the planar
limit of QCD.


title: A Nonlinear Theory of Prestressed Elastic Stick-and-Spring Structures

abstract:
  The discrete modeling of a large class of mechanical structures can be based
on a stick-and-spring concept. We here present a stick-and-spring theory with
potential application to the statics and the dynamics of such nanostructures as
graphene, carbon nanotubes, viral capsids, and others. A key feature of our
theory is its geometrical nonlinearity: we combine exactly defined strain
measures with a general linear stress response; another, rarely found feature
is a careful account of prestress states. A linear version is firstly proposed,
where attention is restricted to study small displacements from an unstressed
reference placement. Next, a theory linearized about a prestressed (preloaded
or not) placement is displayed, which is based on a careful analysis of the
tangent stiffness operator and its two parts, the elastic and prestress
stiffness operators. Finally, two examples are proposed and solved; when an
analytical solution is of prohibitive complication, numerical solutions are
given, by the use of a specifically implemented `stick-and-spring' code.


title:
Exact ground states of one-dimensional long-range random-field Ising
  magnets

abstract:
  We investigate the one-dimensional long-range random-field Ising magnet with
Gaussian distribution of the random fields. In this model, a ferromagnetic bond
between two spins is placed with a probability $p \sim r^{-1-\sigma}$, where
$r$ is the distance between these spins and $\sigma$ is a parameter to control
the effective dimension of the model. Exact ground states at zero temperature
are calculated for system sizes up to $L = 2^{19}$ via graph theoretical
algorithms for four different values of $\sigma \in \{0.25,0.4,0.5,1.0\}$ while
varying the strength $h$ of the random fields. For each of these values several
independent physical observables are calculated, i.e., magnetization, Binder
parameter, susceptibility and a specific-heat-like quantity. The
ferromagnet-paramagnet transitions at critical values $h_c(\sigma)$ as well as
the corresponding critical exponents are obtained. The results agree well with
theory and interestingly we find for $\sigma = 1/2$ the data is compatible with
a critical random-field strength $h_c > 0$.


title: Multiplicative Cauchy functional equation on symmetric cones

abstract:
  We solve the multiplicative Cauchy functional equation on symmetric cones
with respect to two different multiplication algorithms. We impose no
regularity assumptions on respective functions.


title:
The Topology of Information on the Space of Probability Measures over
  Polish Spaces

abstract:
  We study here the topology of information on the space of probability
measures over Polish spaces that was defined in [1]. We show that under this
topology, a convergent sequence of probability measures satisfying a
conditional independence property converges to a measure that also satisfies
the same conditional independence property. In the process of showing this, we
also provide a correct proof of the result in Lemma 4 in [1].


title: Some support properties for a class of Lambda-Fleming-Viot processes

abstract:
  For a class of $\Lambda$-Fleming-Viot processes with underlying Brownian
motion whose associated $\Lambda$-coalescents come down from infinity, we prove
a one-sided modulus of continuity result for their ancestry processes recovered
from the lookdown construction of Donnelly and Kurtz. As applications, we first
show that such a $\Lambda$-Fleming-Viot support process has one-sided modulus
of continuity (with modulus function $C\sqrt{t\log(1/t)}$) at any fixed time.
We also show that the support is compact simultaneously at all positive times,
and given the initial compactness, its range is uniformly compact over any
finite time interval. In addition, under a mild condition on the
$\Lambda$-coalescence rates, we find a uniform upper bound on Hausdorff
dimension of the support and an upper bound on Hausdorff dimension of the
range.


title: Global Fukaya category and quantum Novikov conjecture I

abstract:
  Conceptually, the goal here is a construction which functorially translates a
Hamiltonian fibre bundle to a certain ``derived vector bundle'' over the same
space, with fiber an $A _{\infty} $ category. This ``derived vector bundle''
must remember the continuity of the original bundle. Concretely, using
Floer-Fukaya theory for a monotone $(M, \omega)$ we construct a natural
continuous map \begin{equation*}
  BHam (M, \omega) \to (\mathcal{S}, NFuk (M)), \end{equation*} with
$(\mathcal{S}, NFuk (M))$ denoting the $NFuk (M)$ component of the ``space'' of
$\infty$-categories, where $NFuk (M)$ is the $A _{\infty} $-nerve of the Fukaya
category $Fuk (M)$. This construction is very closely related to the theory of
the Seidel homomorphism and the quantum Chern classes of the author, and this
map is intended to be the deepest expression of their underlying geometric
theory. In part II the above map is shown to be non trivial by an explicit
calculation. In particular we arrive at a new non-trivial ``quantum'' invariant
of any smooth manifold and a ``quantum'' Novikov conjecture.


title: Towards the ASTRI mini-array

abstract:
  The Cherenkov Telescope Array (CTA) will consist of an array of three types
of telescopes covering a wide energy range, from tens of GeV up to more than
100 TeV. The high energy section (> 3 TeV) will be covered by the Small Size
Telescopes (SST). ASTRI (Astrofisica con Specchi a Tecnologia Replicante
Italiana) is a flagship project of the Italian Ministry of Research and
Education led by INAF, aiming at the design and construction of a prototype of
the Dual Mirror SST. In a second phase the ASTRI project foresees the
installation of the first elements of the SST array at the CTA southern site, a
mini-array of 5-7 telescopes. The optimization of the layout of this mini-array
embedded in the SST array of the CTA Observatory has been the object of an
intense simulation effort. In this work we present the expected mini-array
performance in terms of energy threshold, angular and energy resolution and
sensitivity.


title: Conformal Field Theory of Critical Casimir Interactions in 2D

abstract:
  Thermal fluctuations of a critical system induce long-ranged Casimir forces
between objects that couple to the underlying field. For two dimensional (2D)
conformal field theories (CFT) we derive an exact result for the Casimir
interaction between two objects of arbitrary shape, in terms of (1) the free
energy of a circular ring whose radii are determined by the mutual capacitance
of two conductors with the objects' shape; and (2) a purely geometric energy
that is proportional to conformal charge of the CFT, but otherwise
super-universal in that it depends only on the shapes and is independent of
boundary conditions and other details.


title: On the rank of the fibers of elliptic K3 surfaces

abstract:
  Let $X$ be an elliptic K3 surface endowed with two distinct Jacobian elliptic
fibrations $\pi_i$, $i=1,2$, defined over a number field $k$. We prove that
there is an elliptic curve $C\subset X$ such that the generic rank over $k$ of
$X$ after a base extension by $C$ is strictly larger than the generic rank of
$X$. Moreover, if the generic rank of $\pi_j$ is positive then there are
infinitely many fibers of $\pi_i$ ($j\neq i$) with rank at least the generic
rank of $\pi_i$ plus one.


title: On the Maximum Mass of Neutron Stars

abstract:
  One of the most intringuing questions about neutron stars concerns their
maximum mass. The answer is intimately related to the properties of matter at
densities far beyond that found in heavy atomic nuclei. The current view on the
internal constitution of neutron stars and on their maximum mass, both from
theoretical and observational studies, are briefly reviewed.


title: Do Cloaked Objects Really Scatter Less?

abstract:
  We discuss the global scattering response of invisibility cloaks over the
entire frequency spectrum, from static to very high frequencies. Based on
linearity, causality and energy conservation we show that the total extinction
and scattering, integrated over all wavelengths, of any linear, passive, causal
and non-diamagnetic cloak necessarily increases compared to the uncloaked case.
In light of this general principle, we provide a quantitative measure to
compare the global performance of different cloaking techniques and we discuss
solutions to minimize the global scattering signature of an object using thin,
superconducting shells. Our results provide important physical insights on how
invisibility cloaks operate and affect the global scattering of an object,
suggesting ways to defeat countermeasures aimed at detecting cloaked objects
using short impinging pulses.


title:
Glass and jamming transition of simple liquids: static and dynamic
  theory

abstract:
  We study the glass and jamming transition of finite-dimensional models of
simple liquids: hard- spheres, harmonic spheres and more generally bounded pair
potentials that modelize frictionless spheres in interaction. At finite
temperature, we study their glassy dynamics via field-theoretic methods by
resorting to a mapping towards an effective quantum mechanical evolution, and
show that such an approach resolves several technical problems encountered with
previous attempts. We then study the static, mean-field version of their glass
transition via replica theory, and set up an expansion in terms of the
corresponding static order parameter. Thanks to this expansion, we are able to
make a direct and exact comparison between historical Mode-Coupling results and
replica theory. Finally we study these models at zero temperature within the
hypotheses of the random-first-order-transition theory, and are able to derive
a quantitative mean-field theory of the jamming transition. The theoretic
methods of field theory and liquid theory used in this work are presented in a
mostly self-contained, and hopefully pedagogical, way. This manuscript is a
corrected version of my PhD thesis, defended in June, 29th, under the
advisorship of Fr\'ed\'eric van Wijland, and also contains the result of
collaborations with Ludovic Berthier and Francesco Zamponi. The PhD work was
funded by a CFM-JP Aguilar grant, and conducted in the Laboratory MSC at
Universit\'e Denis Diderot--Paris 7, France.


title:
Nonequilibrium dissipation-free transport in F1-ATPase and the
  thermodynamic role of asymmetric allosterism

abstract:
  F1-ATPase (or F1), the highly-efficient and reversible biochemical engine,
has motivated physicists as well as biologists to imagine the design principles
governing machines in the fluctuating world. Recent experiments have clarified
yet another interesting property of F1; the dissipative heat inside the motor
is very small, irrespective of the velocity of rotation and energy transport.
Conceptual interest is devoted to the fact that the amount of internal
dissipation is not simply determined by the sequence of equilibrium pictures,
but also relies on the rotational-angular dependence of nucleotide affinity,
which is a truly nonequilibrium aspect. We propose that the totally asymmetric
allosteric model (TASAM), where adenosine triphosphate (ATP) binding to F1 is
assumed to have low dependence on the angle of the rotating shaft, produces
results that are most consistent with the experiment. Theoretical analysis
proves the crucial role of two time scales in the model, which explains the
universal mechanism to produce the internal dissipation-free feature. The model
reproduces the characteristic torque dependence of the rotational velocity of
F1, and predicts that the internal dissipation upon the ATP synthesis direction
rotation becomes large at the low nucleotide condition.


title: Combinatorial proof of the skew K-saturation theorem

abstract:
  We give a combinatorial proof of the skew Kostka analogue of the K-saturation
theorem. More precisely, for any positive integer k, we give an explicit
injection from the set of skew semistandard Young tableaux with skew shape
k\lambda/k\mu{} and type k\nu{} to the set of skew semistandard Young tableaux
of shape \lambda/\mu{} and type \nu.
  Based on this method, we pose some natural conjectural refinements on related
problems.


title:
Filtergraph: An Interactive Web Application for Visualization of
  Astronomy Datasets

abstract:
  Filtergraph is a web application being developed and maintained by the
Vanderbilt Initiative in Data-intensive Astrophysics (VIDA) to flexibly and
rapidly visualize a large variety of astronomy datasets of various formats and
sizes. The user loads a flat-file dataset into Filtergraph which automatically
generates an interactive data portal that can be easily shared with others.
From this portal, the user can immediately generate scatter plots of up to 5
dimensions as well as histograms and tables based on the dataset. Key features
of the portal include intuitive controls with auto-completed variable names,
the ability to filter the data in real time through user-specified criteria,
the ability to select data by dragging on the screen, and the ability to
perform arithmetic operations on the data in real time. To enable seamless data
visualization and exploration, changes are quickly rendered on screen and
visualizations can be exported as high quality graphics files. The application
is optimized for speed in the context of large datasets: for instance, a plot
generated from a stellar database of 3.1 million entries renders in less than 2
seconds on a standard web server platform. This web application has been
created using the Web2py web framework based on the Python programming
language. Filtergraph is free to use at http://filtergraph.vanderbilt.edu/.


title: The $\pi\rho$ Cloud Contribution to the $\omega$ Width in Nuclear Matter

abstract:
  The width of the $\omega$ meson in cold nuclear matter is computed in a
hadronic many-body approach, focusing on a detailed treatment of the medium
modifications of intermediate $\pi\rho$ states. The $\pi$ and $\rho$
propagators are dressed by their selfenergies in nuclear matter taken from
previously constrained many-body calculations. The pion selfenergy includes
$Nh$ and $\Delta h$ excitations with short-range correlations, while the $\rho$
selfenergy incorporates the same dressing of its $2\pi$ cloud with a full
3-momentum dependence and vertex corrections, as well as direct resonance-hole
excitations; both contributions were quantitatively fit to total
photo-absorption spectra and $\pi N\to\rho N$ scattering. Our calculations
account for in-medium decays of type $\omega N\to \pi N^{(*)}, \pi\pi
N(\Delta)$, and 2-body absorptions $\omega NN\to NN^{(*)},\pi NN$. This causes
deviations of the in-medium $\omega$ width from a linear behavior in density,
with important contributions from spacelike $\rho$ propagators. The $\omega$
width from the $\rho\pi$ cloud may reach up to 200 MeV at normal nuclear matter
density, with a moderate 3-momentum dependence. This largely resolves the
discrepancy of linear $T$-$\varrho$ approximations with the values deduced from
nuclear photoproduction measurements.


title:
Asymptotic Approximation of the Dirichlet to Neumann Map of High
  Contrast Conductive Media

abstract:
  We present an asymptotic study of the Dirichlet to Neumann map of high
contrast composite media with perfectly conducting inclusions that are close to
touching. The result is an explicit characterization of the map in the
asymptotic limit of the distance between the particles tending to zero.


title:
Information and treatment of unknown correlations in the combination of
  measurements using the BLUE method

abstract:
  We discuss the effect of large positive correlations in the combinations of
several measurements of a single physical quantity using the Best Linear
Unbiased Estimate (BLUE) method. We suggest a new approach for comparing the
relative weights of the different measurements in their contributions to the
combined knowledge about the unknown parameter, using the well-established
concept of Fisher information. We argue, in particular, that one We discuss the
effect of large positive correlations in the combinations of several
measurements of a single physical quantity using the Best Linear Unbiased
Estimate (BLUE) method. We suggest a new approach for comparing the relative
weights of the different measurements in their contributions to the combined
knowledge about the unknown parameter, using the well-established concept of
Fisher information. We argue, in particular, that one contribution to
information comes from the collective interplay of the measurements through
their correlations and that this contribution cannot be attributed to any of
the individual measurements alone. We show that negative coefficients in the
BLUE weighted average invariably indicate the presence of a regime of high
correlations, where the effect of further increasing some of these correlations
is that of reducing the error on the combined estimate. In these regimes, we
stress that assuming fully correlated systematic uncertainties is not a truly
conservative choice, and that the correlations provided as input to BLUE
combinations need to be assessed with extreme care instead. In situations where
the precise evaluation of these correlations is impractical, or even
impossible, we provide tools to help experimental physicists perform more
conservative combinations.


title:
On the relaxation towards equilibrium in an isolated strongly correlated
  1D Bose gas

abstract:
  In this work we study the time evolution of soft core bosons on a
one-dimensional lattice, where the particles are initially quenched into a
atomic density wave. At time $t=0$ the particles are released from the quench
and can evolve under the dynamics of a soft-core Bose-Hubbard Hamiltonian on a
lattice including a confining trap.


title: Slices of Co-Operations for $KGL$

abstract:
  We verify a conjecture of Voevodsky, concerning the slices of co-operations
in motivic $K$-theory.


title: On harmonic functions and the hyperbolic metric

abstract:
  Motivated by some recent results of Kalaj and Vuorinen (Proc. Amer. Math.
Soc., 2012), we prove that positive harmonic functions defined in the upper
half--plane are contractions w.r.t. hyperbolic metrics of half--plane and
positive part of the real line, respectively


title:
Asymmetry of the Kolmogorov complexity of online predicting odd and even
  bits

abstract:
  Symmetry of information states that $C(x) + C(y|x) = C(x,y) + O(\log C(x))$.
We show that a similar relation for online Kolmogorov complexity does not hold.
Let the even (online Kolmogorov) complexity of an n-bitstring $x_1x_2... x_n$
be the length of a shortest program that computes $x_2$ on input $x_1$,
computes $x_4$ on input $x_1x_2x_3$, etc; and similar for odd complexity. We
show that for all n there exist an n-bit x such that both odd and even
complexity are almost as large as the Kolmogorov complexity of the whole
string. Moreover, flipping odd and even bits to obtain a sequence
$x_2x_1x_4x_3\ldots$, decreases the sum of odd and even complexity to $C(x)$.


title: Magneto-optical conductivity of graphene on polar substrates

abstract:
  We theoretically study the effect of polar substrates on the magneto-optical
conductivity of doped monolayer graphene, where we particularly focus on the
role played by surface polar phonons (SPPs). Our calculations suggest that
polaronic shifts of the intra- and interband absorption peaks can be
significantly larger for substrates with strong electron-SPP coupling than
those in graphene on non-polar substrates, where only intrinsic graphene
optical phonons with much higher energies contribute. Electron-phonon
scattering and phonon-assisted transitions are, moreover, found to result in a
loss of spectral weight at the absorption peaks. The strength of these
processes is strongly temperature-dependent and with increasing temperatures
the magneto-optical conductivity becomes increasingly affected by polar
substrates, most noticeably in polar substrates with small SPP energies such as
HfO$_2$. The inclusion of a Landau level-dependent scattering rate to account
for Coulomb impurity scattering does not alter this qualitative picture, but
can play an important role in determining the lineshape of the absorption
peaks, especially at low temperatures, where impurity scattering dominates.


title:
Quantum Monte Carlo calculation of the Fermi liquid parameters of the
  two-dimensional homogeneous electron gas

abstract:
  Fermi liquid theory is the basic paradigm within which we understand the
normal behavior of interacting electron systems, but quantitative values for
the parameters that occur in this theory are currently unknown in many
important cases. One such case is the two-dimensional homogeneous electron gas
(2D HEG), which is realized in a wide variety of semiconductor devices. We have
used quantum Monte Carlo (QMC) methods to calculate the Landau interaction
functions between pairs of quasiparticles. We use these to study the Fermi
liquid parameters, finding that finite-size effects represent a serious
obstacle to the direct determination of Fermi liquid parameters in QMC
calculations. We have used QMC data in the literature for other properties of
the 2D HEG to assemble a set of "best available" values for the Fermi liquid
parameters.


title: Variational orthogonalization

abstract:
  We introduce variational methods for finding approximate eigenfunctions and
eigenvalues of quantum Hamiltonians by constructing a set of orthogonal wave
functions which approximately solve the eigenvalue equation.


title: Neutrino pair emission from thermally excited nuclei in stellar collapse

abstract:
  We examine the rate of neutrino-antineutrino pair emission by hot nuclei in
collapsing stellar cores. The rates are calculated assuming that only allowed
charge-neutral Gamow-Teller (GT$_0$) transitions contribute to the decay of
thermally excited nuclear states. To obtain the GT$_0$ transition matrix
elements, we employ the quasiparticle random phase approximation extended to
finite temperatures within the thermo field dynamics formalism. The decay rates
and the energy emission rates are calculated for the sample nuclei ${}^{56}$Fe
and $^{82}$Ge at temperatures relevant to core collapse supernovae.


title:
Theory of plasmonic waves on a chain of metallic nanoparticles in a
  liquid crystalline host

abstract:
  A chain of metallic particles, of sufficiently small diameter and spacing,
allows linearly polarized plasmonic waves to propagate along the chain. In this
paper, we describes how these waves are altered when the liquid crystal host is
a nematic or a cholesteric liquid crystal (NLC or CLC) with or without an
applied magnetic field. We find that, in general, the liquid crystal host,
either NLC or CLC, alters the dispersion relations of the transverse ($T$) and
longitudinal ($L$) waves significantly from the dispersion relations for an
isotropic host. We show that by altering the director axis of the liquid
crystal relative to the long axis of the metallic chain, that the $T$ branch
can be split into two non-degenerate linearly polarized branches (NLC host) or
two non-degenerate elliptically polarized branches (CLC host). When an external
magnetic field is applied parallel to both the long axis of the metallic
particles and the director of the CLC host, we find that the dispersion
relations are odd in an exchange in sign for $\omega$ for the non-degenerate
elliptically polarized $T$ branches. That is, the application of an external
magnetic field leads to the realization of a one-way waveguide.


title:
Electron Cloud Buildup Characterization Using Shielded Pickup
  Measurements and Custom Modeling Code at CESRTA

abstract:
  The Cornell Electron Storage Ring Test Accelerator experimental program
includes investigations into electron cloud buildup, applying various
mitigation techniques in custom vacuum chambers. Among these are two 1.1-m-long
sections located symmetrically in the east and west arc regions. These chambers
are equipped with pickup detectors shielded against the direct beam-induced
signal. They detect cloud electrons migrating through an 18-mm-diameter pattern
of small holes in the top of the chamber. A digitizing oscilloscope is used to
record the signals, providing time-resolved information on cloud development.
Carbon-coated, TiN-coated and uncoated aluminum chambers have been tested.
Electron and positron beams of 2.1, 4.0 and 5.3 GeV with a variety of bunch
populations and spacings in steps of 4 and 14 ns have been used. Here we report
on results from the ECLOUD modeling code which highlight the sensitivity of
these measurements to the physical phenomena determining cloud buildup such as
the photoelectron production azimuthal and energy distributions, and the
secondary yield parameters including the true secondary, re-diffused, and
elastic yield values.


title: Unidentified species in envelopes around carbon stars

abstract:
  The infrared (IR) spectra of many evolved carbon-rich stars exhibit two
prominent dust emission features peaking around 21um and 30um, with the former
exclusively seen in proto-planetary nebulae (PPNe), while the latter seen in a
much wider range of objects, including AGB stars, PPNe and planetary nebulae
(PNe). The 30um feature is seen in all the 21um sources, but no correlation is
found between these two features. Over a dozen carrier candidates have been
proposed for the 21um feature, but none of them has been widely accepted and
the nature of the 21um feature remains a mystery. The carrier of the 30um
feature also remains unidentied. MgS dust, once widely accepted as a valid
carrier, was ruled out because of the sulfur budget problem. In this work we
examine nano-sized FeO dust as a carrier for the 21um feature. We calculate the
IR emission spectrum of FeO nanodust which undergoes single-photon heating in
PPNe. It is found that the 21um feature emitted by FeO nanodust is too broad to
explain the observed feature. For the 30um feature, we argue that graphite
could be a viable carrier. Graphite, provided its d.c. conductivity sigma_dc
exceeding 100/ohm/cm, exhibits a pronounced band at 30um.


title: Sub-millimeter observations of IRAS and WISE debris disk candidates

abstract:
  A set of six debris disk candidates identified with IRAS or WISE excesses
were observed at either 350 um or 450 um with the CSO. Five of the targets -
HIP 51658, HIP 68160, HIP 73512, HIP 76375, and HIP 112460 - have among the
largest measured excess emission from cold dust from IRAS in the 25-100 um
bands. Single temperature blackbody fits to the excess dust emission of these
sources predict 350-450 um fluxes above 240 mJy. The final target - HIP 73165 -
exhibits weak excess emission above the stellar photosphere from WISE
measurements at 22 um, indicative of a population of warm circumstellar dust.
None of the six targets were detected, with 3 sigma upper limits ranging from
51-239 mJy. These limits are significantly below the expected fluxes from SED
fitting. Two potential causes of the null detections were explored - companion
stars and contamination. To investigate the possible influence of companion
stars, imaging data were analyzed from new AO data from the MMT and archival
HST, NIRI, and POSS/2MASS data. The images are sensitive to all stellar
companions beyond a radius of 1-94 AU. One target is identified as a binary
system, but with a separation too large to impact the disk. While the
gravitational effects of a companion do not appear to provide an explanation
for the submm upper limits, the majority of the IRAS excess targets show
evidence for contaminating sources, based on investigation of higher resolution
WISE and archival Spitzer and Herschel images. Finally, the exploratory submm
measurements of the WISE excess source suggest that the hot dust present around
these targets is not matched by a comparable population of colder, outer dust.
More extensive and more sensitive Herschel observations of WISE excess sources
will build upon this initial example to further define the characteristics of
warm debris disks sources.


title: Weak value amplification is suboptimal for estimation and detection

abstract:
  We show using statistically rigorous arguments that the technique of weak
value amplification (WVA) does not perform better than standard statistical
techniques for the tasks of single parameter estimation and signal detection.
Specifically we prove that post-selection, a necessary ingredient for WVA,
decreases estimation accuracy and, moreover, arranging for anomalously large
weak values is a suboptimal strategy. In doing so, we explicitly provide the
optimal estimator, which in turn allows us to identify the optimal experimental
arrangement to be the one in which all outcomes have equal weak values (all as
small as possible) and the initial state of the meter is the maximal eigenvalue
of the square of the system observable. Finally, we give precise quantitative
conditions for when weak measurement (measurements without post-selection or
anomalously large weak values) can mitigate the effect of uncharacterized
technical noise in estimation.


title: Information Geometry of Complex Hamiltonians and Exceptional Points

abstract:
  Information geometry provides a tool to systematically investigate parameter
sensitivity of the state of a system. If a physical system is described by a
linear combination of eigenstates of a complex (that is, non-Hermitian)
Hamiltonian, then there can be phase transitions where dynamical properties of
the system change abruptly. In the vicinities of the transition points, the
state of the system becomes highly sensitive to the changes of the parameters
in the Hamiltonian. The parameter sensitivity can then be measured in terms of
the Fisher-Rao metric and the associated curvature of the parameter-space
manifold. A general scheme for the geometric study of parameter-space manifolds
of eigenstates of complex Hamiltonians is outlined here, leading to generic
expressions for the metric.

categories: quant-ph cond-mat.stat-mech math-ph math.MP


title: Quantum quenches and thermalization on scale-free graphs

abstract:
  We show that after a quantum quench of the parameter controlling the number
of particles in a Fermi-Hubbard model on scale free graphs, the distribution of
energy modes follows a power law dependent on the quenched parameter and the
connectivity of the graph. This paper contributes to the literature of quantum
quenches on lattices, in which, for many integrable lattice models the
distribution of modes after a quench thermalizes to a Generalized Gibbs
Ensemble; this paper provides another example of distribution which can arise
after relaxation. We argue that the main role is played by the symmetry of the
underlying lattice which, in the case we study, is scale free, and to the
distortion in the density of modes.


title: Solar Magnetic Tracking. IV. The Death of Magnetic Features

abstract:
  The removal of magnetic flux from the quiet-sun photosphere is important for
maintaining the statistical steady-state of the magnetic field there, for
determining the magnetic flux budget of the Sun, and for estimating the rate of
energy injected into the upper solar atmosphere. Magnetic feature death is a
measurable proxy for the removal of detectable flux. We used the SWAMIS feature
tracking code to understand how nearly 20000 detected magnetic features die in
an hour-long sequence of Hinode/SOT/NFI magnetograms of a region of quiet Sun.
Of the feature deaths that remove visible magnetic flux from the photosphere,
the vast majority do so by a process that merely disperses the
previously-detected flux so that it is too small and too weak to be detected.
The behavior of the ensemble average of these dispersals is not consistent with
a model of simple planar diffusion, suggesting that the dispersal is
constrained by the evolving photospheric velocity field. We introduce the
concept of the partial lifetime of magnetic features, and show that the partial
lifetime due to Cancellation of magnetic flux, 22 h, is 3 times slower than
previous measurements of the flux turnover time. This indicates that prior
feature-based estimates of the flux replacement time may be too short, in
contrast with the tendency for this quantity to decrease as resolution and
instrumentation have improved. This suggests that dispersal of flux to smaller
scales is more important for the replacement of magnetic fields in the quiet
Sun than observed bipolar cancellation. We conclude that processes on spatial
scales smaller than those visible to Hinode dominate the processes of flux
emergence and cancellation, and therefore also the quantity of magnetic flux
that threads the photosphere.


title: Ramsey-Bord\'e interferometer for electrons

abstract:
  A scheme to realize an electron interferometer using low-intensity,
bi-chromatic laser pulses as beam splitter is proposed. The splitting process
is based on a modification of the Kapitza-Dirac effect, which produces a
momentum kick for electrons with a specific initial momentum. A full
interferometric setup in Ramsey-Bord\'e configuration is theoretically
analyzed.


title: C-metric with a conformally coupled scalar field in a magnetic universe

abstract:
  In Einstein-Maxwell gravity with a conformally coupled scalar field, the
black hole found by Bocharova, Bronnikov, Melnikov, and Bekenstein breaks when
embedded in the external magnetic field of the Melvin universe. The situation
improves in presence of acceleration, allowing one to build magnetised and
accelerating BBMB black hole with a thin membrane. But to overcome this and
others disadvantages of BBMB spacetimes, a new class of black holes, including
the rotating case, is proposed for the conformal matter coupling under
consideration.


title:
Evidence for massive bulk Dirac Fermions in Pb$_{1-x}$Sn$_x$Se from
  Nernst and thermopower experiments

abstract:
  The lead chalcogenides (Pb,Sn)Te and (Pb,Sn)Se are the first examples of
topological crystalline insulators (TCI) predicted \cite{Fu,Hsieh} (and
confirmed \cite{Hasan,Story,Takahashi}) to display topological surface Dirac
states (SDS) that are protected by mirror symmetry. A starting premise
\cite{Hsieh} is that the SDS arise from bulk states describable as massive
Dirac states \cite{Wallis,Svane}, but this assumption is untested. Here we show
that the thermoelectric response of the bulk states display features specific
to the Dirac spectrum. We show that, in the quantum limit, the lowest Landau
Level (LL) is singly spin-degenerate, whereas higher levels are doubly
degenerate. The abrupt change in spin degeneracy leads to a large step-decrease
in the thermopower $S_{xx}$. In the lowest LL, $S_{xx}$ displays a striking
linear increase vs. magnetic field. In addition, the Nernst signal undergoes an
anomalous sign change when the bulk gap inverts at 180 K.