title: Scaling up Dynamic Topic Models

abstract:
  Dynamic topic models (DTMs) are very effective in discovering topics and
capturing their evolution trends in time series data. To do posterior inference
of DTMs, existing methods are all batch algorithms that scan the full dataset
before each update of the model and make inexact variational approximations
with mean-field assumptions. Due to a lack of a more scalable inference
algorithm, despite the usefulness, DTMs have not captured large topic dynamics.
  This paper fills this research void, and presents a fast and parallelizable
inference algorithm using Gibbs Sampling with Stochastic Gradient Langevin
Dynamics that does not make any unwarranted assumptions. We also present a
Metropolis-Hastings based $O(1)$ sampler for topic assignments for each word
token. In a distributed environment, our algorithm requires very little
communication between workers during sampling (almost embarrassingly parallel)
and scales up to large-scale applications. We are able to learn the largest
Dynamic Topic Model to our knowledge, and learned the dynamics of 1,000 topics
from 2.6 million documents in less than half an hour, and our empirical results
show that our algorithm is not only orders of magnitude faster than the
baselines but also achieves lower perplexity.


title:
An accelerated exponential time integrator for semi-linear stochastic
  strongly damped wave equation with additive noise

abstract:
  This paper is concerned with the strong approximation of a semi-linear
stochastic wave equation with strong damping, driven by additive noise. Based
on a spatial discretization performed by a spectral Galerkin method, we
introduce a kind of accelerated exponential time integrator involving linear
functionals of the noise. Under appropriate assumptions, we provide error
bounds for the proposed full-discrete scheme. It is shown that the scheme
achieves higher strong order in time direction than the order of temporal
regularity of the underlying problem, which allows for higher convergence rate
than usual time-stepping schemes. For the space-time white noise case in two or
three spatial dimensions, the scheme still exhibits a good convergence
performance. Another striking finding is that, even for the velocity with low
regularity the scheme always promises first order strong convergence in time.
Numerical examples are finally reported to confirm our theoretical findings.


title: Bridge number and twist equivalence of Seifert surfaces

abstract:
  Two Seifert surfaces of links in $S^3$ are said to be twist equivalent if one
can be obtained from the other, up to isotopy, by repeatedly performing
operations consisting of cutting along an embedded arc, applying a full twist
near one copy of the arc, and re-gluing. By using bridge spheres for their
boundary links, we provide a new method of distinguishing twist equivalence
classes of Seifert surfaces of any given genus. Given a Seifert surface $F$ of
a link $L$, we show that the bridge numbers of the boundary links of Seifert
surfaces twist equivalent to $F$ are uniformly bounded above by a constant
depending only on $F$. By computing this constant in one simple case and
applying a result of Pfeuti, we deduce that $b(L)\leq 2g_c(L)+|L|$ for any link
$L$ in $S^3$, where $g_c(L)$ denotes the canonical genus of $L$. Various
consequences of this inequality are discussed. We then apply the main theorem
to show that there are infinitely many distinct twist equivalence classes
represented by free, genus one Seifert surfaces, answering a question of Pfeuti
in the negative.


title: Strong Backdoors for Default Logic

abstract:
  In this paper, we introduce a notion of backdoors to Reiter's propositional
default logic and study structural properties of it. Also we consider the
problems of backdoor detection (parameterised by the solution size) as well as
backdoor evaluation (parameterised by the size of the given backdoor), for
various kinds of target classes (cnf, horn, krom, monotone, identity). We show
that backdoor detection is fixed-parameter tractable for the considered target
classes, and backdoor evaluation is either fixed-parameter tractable, in
para-DP2 , or in para-NP, depending on the target class.


title: First-order Methods for Geodesically Convex Optimization

abstract:
  Geodesic convexity generalizes the notion of (vector space) convexity to
nonlinear metric spaces. But unlike convex optimization, geodesically convex
(g-convex) optimization is much less developed. In this paper we contribute to
the understanding of g-convex optimization by developing iteration complexity
analysis for several first-order algorithms on Hadamard manifolds.
Specifically, we prove upper bounds for the global complexity of deterministic
and stochastic (sub)gradient methods for optimizing smooth and nonsmooth
g-convex functions, both with and without strong g-convexity. Our analysis also
reveals how the manifold geometry, especially \emph{sectional curvature},
impacts convergence rates. To the best of our knowledge, our work is the first
to provide global complexity analysis for first-order algorithms for general
g-convex optimization.


title:
Electronic orders in multi-orbital Hubbard models with lifted orbital
  degeneracy

abstract:
  We study the symmetry-broken phases in two- and three-orbital Hubbard models
with lifted orbital degeneracy using dynamical mean field theory. On the
technical level, we explain how symmetry relations can be exploited to measure
the four-point correlation functions needed for the calculation of the lattice
susceptibilities. In the half-filled two-orbital model with crystal field
splitting, we find an instability of the metallic phase to spin-orbital order
with neither spin nor orbital moment. This ordered phase is shown to be related
to the recently discovered fluctuating-moment induced spin-triplet
superconducting state in the orbitally degenerate model with shifted chemical
potential. In the three-orbital case, we consider the effect of a crystal field
splitting on the spin-triplet superconducting state in the model with positive
Hund coupling, and the spin-singlet superconducting state in the case of
negative Hund coupling. It is demonstrated that for certain crystal field
splittings the higher energy orbitals instead of the lower ones are relevant
for superconductivity, and that $T_c$ can be enhanced by the crystal field
effect. We comment on the implications of our results for the superconductivity
in strontium ruthenates, and for the recently reported light-enhanced
superconducting state in alkali-doped fullerides.


title:
Distinctive response of many-body localized systems to strong electric
  field

abstract:
  We study systems which are close to or within the many-body localized (MBL)
regime and are driven by strong electric field. In the ergodic regime, the
disorder extends applicability of the equilibrium linear--response theory to
stronger drivings, whereas the response of the MBL systems is very distinctive,
revealing currents with damped oscillations. The oscillation frequency is
independent of driving and the damping is not due to heating but rather due to
dephasing. The details of damping depend on the system's history reflecting
nonergodicity of the MBL phase, while the frequency of the oscillations remains
a robust hallmark of localization. We show that the distinctive characteristic
of the driven MBL phase is also a logarithmic increase of the energy and the
polarization with time.


title:
A Convex Polynomial Force-Motion Model for Planar Sliding:
  Identification and Application

abstract:
  We propose a polynomial force-motion model for planar sliding. The set of
generalized friction loads is the 1-sublevel set of a polynomial whose gradient
directions correspond to generalized velocities. Additionally, the polynomial
is confined to be convex even-degree homogeneous in order to obey the maximum
work inequality, symmetry, shape invariance in scale, and fast invertibility.
We present a simple and statistically-efficient model identification procedure
using a sum-of-squares convex relaxation. Simulation and robotic experiments
validate the accuracy and efficiency of our approach. We also show practical
applications of our model including stable pushing of objects and free sliding
dynamic simulations.


title: Uniresolution representations of white-matter data from CoCoMac

abstract:
  Tracing data as collated by CoCoMac, a seminal neuroinformatics database, is
at multiple resolutions -- white matter tracts were studied for areas and their
subdivisions by different reports. Network theoretic analysis of this
multi-resolution data often assumes that the data at various resolutions is
equivalent, which may not be correct. In this paper we propose three methods to
resolve the multi-resolution issue such that the resultant networks have
connectivity data at only one resolution. The different resultant networks are
compared in terms of their network analysis metrics and degree distributions.


title: Binarization Trees and Random Number Generation

abstract:
  An m-extracting procedure produces unbiased random bits from a loaded dice
with m faces. A binarization takes inputs from an m-faced dice and produce bit
sequences to be fed into a (binary) extracting procedure to obtain random bits.
Thus, binary extracting procedures give rise to an m-extracting procedure via a
binarization. An entropy- preserving binarization is to be called complete, and
such a procedure has been proposed by Zhou and Bruck. We show that there exist
complete binarizations in abundance as naturally arising from binary trees with
m leaves. The well-known leaf entropy theorem and a closely related structure
lemma play important roles in the arguments.


title: Non-Thermal Einstein Relations

abstract:
  We consider a particle moving with equation of motion $\dot x=f(t)$, where
$f(t)$ is a random function with statistics which are independent of $x$ and
$t$, with a finite drift velocity $v=\langle f\rangle$ and in the presence of a
reflecting wall. Far away from the wall, translational invariance implies that
the stationary probability distribution is $P(x)\sim \exp(\alpha x)$. A
classical example of a problem of this type is sedimentation equilibrium, where
$\alpha$ is determined by temperature. In this work we do not introduce a
thermal reservoir and $\alpha$ is determined from the equation of motion. We
consider a general approach to determining $\alpha$ which is not always in
agreement with Einstein's relation between the mean velocity and the diffusion
coefficient. We illustrate our results with a model inspired by the Boltzmann
equation.


title:
Electromagnetic and Weak Nuclear Structure Functions $F_{1,2}(x,Q^2)$ in
  the Intermediate Region of $Q^2$

abstract:
  We have studied nuclear structure functions $F_{1A}(x,Q^2)$ and
$F_{2A}(x,Q^2)$ for electromagnetic and weak processes in the region of $1
GeV^2 < Q^2 <8 GeV^2$. The nuclear medium effects arising due to Fermi motion,
binding energy, nucleon correlations, mesonic contributions and shadowing
effects are taken into account using a many body field theoretical approach.
The calculations are performed in a local density approximation using a
relativistic nucleon spectral function. The results are compared with the
available experimental data. Implications of nuclear medium effects on the
validity of Callan-Gross relation are also discussed.


title:
Revisiting $\nu_\mu(\bar\nu_\mu)$ and $\nu_e(\bar\nu_e) $ Induced
  Quasielastic Scattering from Nuclei in Sub-GeV Energy Region

abstract:
  We present the results of charged current quasielastic(CCQE) scattering cross
sections from free as well as bound nucleons like in $^{12}C$, $^{16}O$,
$^{40}Ar$ and $^{208}Pb$ nuclear targets in $E_\nu(_{\bar\nu})~\le~ $1 GeV
energy region.
  The results are obtained using local Fermi gas model with and without RPA
effect.
  The differences those may arise in the electron and muon production cross
sections due to the different lepton mass, uncertainties in the axial dipole
mass $M_A$ and pseudoscalar form factor, and due to the inclusion of second
class currents have been highlighted for neutrino/antineutrino induced
processes.


title:
The pseudo-gap phase and the duality in holographic fermionic system
  with dipole coupling on Q-lattice

abstract:
  We classify the different phases by the "pole-zero mechanism" for a
holographic fermionic system which contains a dipole coupling with strength $p$
on a Q-lattice background. A complete phase structure in $p$ space can be
depicted in terms of Fermi liquid, non-Fermi liquid, Mott phase and pseudo-gap
phase. In particular, we find that in general the region of the pseudo-gap
phase in $p$ space is suppressed when the Q-lattice background is dual to a
deep insulating phase, while for an anisotropic background, we have an
anisotropic region for the pseudo-gap phase in $p$ space as well. In addition,
we find that the duality between zeros and poles always exists regardless of
whether or not the model is isotropic.


title:
Pricing and Resource Allocation via Game Theory for a Small-Cell Video
  Caching System

abstract:
  Evidence indicates that downloading on-demand videos accounts for a dramatic
increase in data traffic over cellular networks. Caching popular videos in the
storage of small-cell base stations (SBS), namely, small-cell caching, is an
efficient technology for reducing the transmission latency whilst mitigating
the redundant transmissions of popular videos over back-haul channels. In this
paper, we consider a commercialized small-cell caching system consisting of a
network service provider (NSP), several video retailers (VR), and mobile users
(MU). The NSP leases its SBSs to the VRs for the purpose of making profits, and
the VRs, after storing popular videos in the rented SBSs, can provide faster
local video transmissions to the MUs, thereby gaining more profits. We conceive
this system within the framework of Stackelberg game by treating the SBSs as a
specific type of resources. We first model the MUs and SBSs as two independent
Poisson point processes, and develop, via stochastic geometry theory, the
probability of the specific event that an MU obtains the video of its choice
directly from the memory of an SBS. Then, based on the probability derived, we
formulate a Stackelberg game to jointly maximize the average profit of both the
NSP and the VRs. Also, we investigate the Stackelberg equilibrium by solving a
non-convex optimization problem. With the aid of this game theoretic framework,
we shed light on the relationship between four important factors: the optimal
pricing of leasing an SBS, the SBSs allocation among the VRs, the storage size
of the SBSs, and the popularity distribution of the VRs. Monte-Carlo
simulations show that our stochastic geometry-based analytical results closely
match the empirical ones. Numerical results are also provided for quantifying
the proposed game-theoretic framework by showing its efficiency on pricing and
resource allocation.


title:
On Training Bi-directional Neural Network Language Model with Noise
  Contrastive Estimation

abstract:
  We propose to train bi-directional neural network language model(NNLM) with
noise contrastive estimation(NCE). Experiments are conducted on a rescore task
on the PTB data set. It is shown that NCE-trained bi-directional NNLM
outperformed the one trained by conventional maximum likelihood training. But
still(regretfully), it did not out-perform the baseline uni-directional NNLM.


title: Ergodicity of non-Hamiltonian equilibrium systems

abstract:
  It is well known that ergodic theory can be used to formally prove a weak
form of relaxation to equilibrium for finite, mixing, Hamiltonian systems. In
this Letter we extend this proof to any dynamics that preserves a mixing
equilibrium distribution. The proof uses an approach similar to that used in
umbrella sampling, and demonstrates the need for a form of ergodic consistency
of the initial and final distribution. This weak relaxation only applies to
averages of physical properties. It says nothing about whether the distribution
of states relaxes towards the equilibrium distribution or how long the
relaxation of physical averages takes.


title: Pion production off the nucleon

abstract:
  We have studied charged current neutrino/antineutrino induced weak pion
production from nucleon. For the present study, contributions from
$\Delta(1232)$-resonant term, non-resonant background terms as well as
contribution from higher resonances viz. $P_{11}$(1440), $D_{13}$(1520),
$S_{11}$(1535), $S_{11}$(1650) and $P_{13}$(1720) are taken. To write the
hadronic current for the non-resonant background terms, a microscopic approach
based on SU(2) non-linear sigma model has been used. The vector form factors
for the resonances are obtained from the helicity amplitudes provided by MAID.
Axial coupling in the case of $\Delta(1232)$ resonance is obtained by fitting
the ANL and BNL $\nu$-deuteron reanalyzed scattering data. The results of the
cross sections are presented and discussed for all the possible channels of
single pion production induced by charged current interaction.


title:
Observations of 't Hooft's sublattices and Dirac's monopole by
  inhomogeneous phases of solitons

abstract:
  Here, we experimentally generated photonic graphene by resonance of
inhomogeneously strained one dimensional lattices of triangular solitons. Where
mildly twisted solitons are considered as north and south monopoles, while
strongly twisted solitons are considered as defect north monopoles. Weak
bounding is observed between the opposite monopoles. Strong bounding occurred
between the monopoles with same polarity. Where a defect north monopole is
transformed into a flux-like tube. Which generated an optical analogue of the
torus sublattice. Bogomolny's vortice-like symmetry is remained intact in all
these observations. Dirac's north monopole along with the string is also
observed. The results presented in this paper were also described in terms of
supersymmetry and quantum phase transitions, and reported in ref[20].


title:
Effects of Nuclear Medium on the Sum Rules in Electron and Neutrino
  Scattering

abstract:
  In this work, we study the influence of nuclear medium effects on various
parton model sum rules in nuclei and compare the results with the free nucleon
case. We have used relativistic nucleon spectral function to take into account
Fermi motion, binding and nucleon correlations. The pion and rho meson cloud
contributions have been incorporated in a microscopic model. The effect of
shadowing has also been considered.


title:
A note on the gaps between zeros of Epstein's zeta-functions on the
  critical line

abstract:
  It is proved that Epstein's zeta-function $\zeta_{Q}(s)$, related to a
positive definite integral binary quadratic form, has a zero $1/2 + i\gamma$
with $ T \leq \gamma \leq T + T^{{3/7} +\varepsilon} $ for sufficiently large
positive numbers $T$. This is an improvement of the result by M. Jutila and K.
Srinivas (Bull. London Math. Soc. 37 (2005) 45--53).


title: Vertex-disjoint Cycle Cover for graph signal processing

abstract:
  Eigenvectors of the Laplacian of a cycle graph exhibit the sinusoidal
characteristics of the standard DFT basis, and signals defined on such graphs
are amenable to linear shift invariant (LSI) operations. In this paper we
propose to reduce a generic graph to its vertex-disjoint cycle cover, i.e., a
set of subgraphs that are cycles, that together contain all vertices of the
graph, and no two subgraphs have any vertices in common. Additionally if the
weight of an edge in the graph is a function of the variation in the signals on
its vertices, then maximally smooth cycles can be found, such that the
resulting DFT does not have high frequency components. We show that an image
graph can be reduced to such low-frequency cycles, and use that to propose a
simple image denoising algorithm.


title: The Algebraic Way

abstract:
  In this paper we examine in detail the non-commutative symplectic algebra
underlying quantum dynamics. We show that this algebra contains both the
Weyl-von Neumann algebra and the Moyal algebra. The latter contains the Wigner
distribution as the kernel of the density matrix. The underlying
non-commutative geometry can be projected into either of two Abelian spaces,
so-called `shadow phase spaces'. One of these is the phase space of Bohmian
mechanics, showing that it is a fragment of the basic underlying algebra. The
algebraic approach is much richer, giving rise to two fundamental dynamical
time development equations which reduce to the Liouville equation and the
Hamilton-Jacobi equation in the classical limit. They also include the
Schr\"{o}dinger equation and its wave function, showing that these features are
a partial aspect of the more general non-commutative structure. We discuss
briefly the properties of this more general mathematical background from which
the non-commutative symplectic algebra emerges.


title: MDF: Magnetic Particle Imaging Data Format

abstract:
  Magnetic particle imaging (MPI) is a tomographic method to determine the
spatio-temporal distribution of magnetic nanoparticles. In this document, a
file format for the standardized storage of MPI and magnetic particle
spectroscopy (MPS) data is introduced. The aim of the Magnetic Particle Imaging
Data Format (MDF) is to provide a coherent way of exchanging MPI and MPS data
acquired with different devices worldwide. The focus of the MDF is on sequence
parameters, measurement data, calibration data, and reconstruction data. The
format is based on the hierarchical document format in version 5 (HDF5). This
document discusses the MDF version 2.1.0, which is not backward compatible with
version 1.x.y.


title: Modified group non-membership is in AWPP

abstract:
  It is known that the group non-membership problem is in QMA relative to any
group oracle and in ${\rm SPP}\cap{\rm BQP}$ relative to group oracles for
solvable groups. We consider a modified version of the group non-membership
problem where the order of the group is also given as an additional input. We
show that the problem is in AWPP relative to any group oracle. To show the
result, we use the idea of the postselected quantum computing.


title: Instanton effects on the heavy-quark static potential

abstract:
  We investigate the instanton effects on the heavy-quark potential,including
its spin-dependent part, based on the instanton liquid model. Starting with the
central potential derived from the instanton vacuum, we obtain the
spin-dependent part of the heavy-quark potential. We discuss the results of the
heavy-quark potential from the instanton vacuum. We finally solve the
nonrelativistic two-body problem, associating with the heavy-quark potential
from the instanton vacuum. The instanton effects on the quarkonia spectra are
marginal but are required for quantitative description of the spectra.


title: Olver's Method for Approximating Roots of p-Adic Polynomials Equations

abstract:
  Let $\mathbb{Z}_p[x]$ be the set of all functions whose coefficients are in
the field of $p$-adic integers $\mathbb{Z}_p$. This work considers a problem of
finding a root of a polynomial equation $P(x)=0$ where
$P(x)\in\mathbb{Z}_p[x]$. The solution is approached through an analogue of
Olver's method for finding roots of polynomial equations $P(x)=0$ in
$\mathbb{Z}_p$.


title:
The Extended Spatial Distribution of Globular Clusters in the Core of
  the Fornax Cluster

abstract:
  We report the discovery of a complex extended density enhancement in the
Globular Clusters (GCs) in the central $\sim 0.5(^{\circ})^2$ ($\sim 0.06$
Mpc$^2$) of the Fornax cluster, corresponding to $\sim 50\%$ of the area within
1 core radius. This overdensity connects the GC system of NGC1399 to most of
those of neighboring galaxies within $\sim 0.6^{\circ}$ ($\sim 210$ kpc) along
the W-E direction. The asymmetric density structure suggests that the galaxies
in the core of the Fornax cluster experienced a lively history of interactions
that have left a clear imprint on the spatial distribution of GCs. The extended
central dominant structure is more prominent in the distribution of blue GCs,
while red GCs show density enhancements that are more centrally concentrated on
the host galaxies. We propose that the relatively small-scale density
structures in the red GCs are caused by galaxy-galaxy interactions, while the
extensive spatial distribution of blue GCs is due to stripping of GCs from the
halos of core massive galaxies by the Fornax gravitational potential. Our
investigations is based on density maps of candidate GCs extracted from the
multi-band VLT Survey Telescope (VST) survey of Fornax (FDS), identified in a
three-dimensional color space and further selected based on their $g$-band
magnitude and morphology.


title: Aspects of Algebraic Quantum Theory: a Tribute to Hans Primas

abstract:
  This paper outlines the common ground between the motivations lying behind
Hans Primas' algebraic approach to quantum phenomena and those lying behind
David Bohm's approach which led to his notion of implicate/explicate order.
This connection has been made possible by the recent application of orthogonal
Clifford algebraic techniques to the de Broglie-Bohm approach for relativistic
systems with spin.


title: Neumann to Steklov eigenvalues: asymptotic and monotonicity results

abstract:
  We consider the Steklov eigenvalues of the Laplace operator as limiting
Neumann eigenvalues in a problem of mass concentration at the boundary of a
ball. We discuss the asymptotic behavior of the Neumann eigenvalues and find
explicit formulas for their derivatives at the limiting problem. We deduce that
the Neumann eigenvalues have a monotone behavior in the limit and that Steklov
eigenvalues locally minimize the Neumann eigenvalues.


title: Tribes Is Hard in the Message Passing Model

abstract:
  We consider the point-to-point message passing model of communication in
which there are $k$ processors with individual private inputs, each $n$-bit
long. Each processor is located at the node of an underlying undirected graph
and has access to private random coins. An edge of the graph is a private
channel of communication between its endpoints. The processors have to compute
a given function of all their inputs by communicating along these channels.
While this model has been widely used in distributed computing, strong lower
bounds on the amount of communication needed to compute simple functions have
just begun to appear. In this work, we prove a tight lower bound of
$\Omega(kn)$ on the communication needed for computing the Tribes function,
when the underlying graph is a star of $k+1$ nodes that has $k$ leaves with
inputs and a center with no input. Lower bound on this topology easily implies
comparable bounds for others. Our lower bounds are obtained by building upon
the recent information theoretic techniques of Braverman et.al (FOCS'13) and
combining it with the earlier work of Jayram, Kumar and Sivakumar (STOC'03).
This approach yields information complexity bounds that is of independent
interest.


title: PMT overshoot study for JUNO prototype detector

abstract:
  The quality of PMT signal is one of the key items for a large and high
precision neutrino experiment, like Daya Bay, JUNO, while most of the
experiments are affected by the PMT signal overshoot from its positive
HV-single cable scheme. For JUNO prototype detector, we have a detailed study
on the PMT overshoot and successfully reduced the ratio of overshoot amplitude
to signal to ~1% from previous typical ~10%, with no affection to PMT other
parameters. Furthermore, we calculated that the overshoot is a result of
discharging of capacitors in the HV-signal splitter and the PMT voltage
divider. The study result is extremely important for JUNO and other similar
experiments.


title: Aging in Metropolis dynamics of the REM: a proof

abstract:
  We study the aging behavior of the Random Energy Model (REM) evolving under
Metropolis dynamics. We prove that a classical two-time correlation function
converges almost surely to the arcsine law distribution function that
characterizes activated aging, as predicted in the physics literature, in the
optimal domain of the time-scale and temperature parameters where this result
can be expected to hold. In the course of the proof we establish that a certain
continuous time clock process, after proper rescaling, converges almost surely
to a stable subordinator, improving upon the result of Cerny and Wassmer (2015)
where a closely related clock is shown to converge in probability only, and in
a restricted region of the time-scale and temperature parameters. The random
rescaling involved in this convergence is controlled at the fine level of
fluctuations. As a byproduct, we refine and prove a conjecture made in Cerny
and Wassmer (2015).


title: Distinguishability of countable quantum states and von Neumann lattice

abstract:
  Condition for distinguishability of countably infinite number of pure states
by a single measurement is given. Distinguishability is to be understood as
possibility of an unambiguous measurement. For finite number of states, it is
known that the necessary and sufficient condition of distinguishability is that
the states are linearly independent. For infinite number of states, several
natural classes of distinguishability can be defined. We give a necessary and
sufficient condition for a system of pure states to be distinguishable. It
turns out that each level of distinguishability naturally corresponds to one of
the generalizations of linear independence to families of infinite vectors. As
an important example, we apply the general theory to von Neumann's lattice, a
subsystem of coherent states which corresponds to a lattice in the classical
phase space. We prove that the condition for distinguishability is that the
area of the fundamental region of the lattice is greater than the Planck
constant, and also find subtle behavior on the threshold. These facts reveal
the measurement theoretical meaning of the Planck constant and give a
justification for the interpretation that it is the smallest unit of area in
the phase space. The cases of uncountably many states and of mixed states are
also discussed.


title:
Charge-changing transitions and capture strengths of pf-shell nuclei
  with $T_{z} = -2$ at proton drip-line

abstract:
  Charge-changing transitions, commonly referred to as Gamow-Teller (GT)
transitions, and electron capture/$\beta^{+}$-decay strengths for pf-shell
nuclei with $T_{z} = - 2$ at proton drip-line have been calculated using the
proton-neutron quasi-particle random phase approximation (pn-QRPA) model. The
total GT$_{+}$ strength values and electron capture/$\beta^{+}$-decay rates are
needed for the study of the late stages of the stellar evolution. The pn-QRPA
theory is used for a microscopic calculation of GT strength distribution
functions and associated stellar electron capture/$\beta^{+}$-decay rates of
proton-rich pf-shell nuclei with $T_{z} = - 2$ in the mass range 46 $\leq$ A
$\leq$ 56 at proton drip-line. Standard quenching factor of 0.74, usually
implemented in the shell model calculation, has been incorporated for the
comparison with experimental data (wherever available). The calculated GT
strength of the two proton-rich nuclei, $^{52}$Ni and $^{56}$Zn are compared
with experimental data of corresponding mirror nuclei. It has been found that
the pn-QRPA results are in good agreement with the experimental data as well as
shell model result. It is noted that the total GT strength increases linearly
with the increase of mass number. The electron capture/$\beta^{+}$-decay rates
for proton-rich nuclei are calculated on a temperature and density scale
relevant to presupernova evolution of massive stars. The $\beta^{+}$ decay
half-lives are compared with measured and other theoretical calculations.


title: Coarse medians and Property A

abstract:
  We prove that uniformly locally finite quasigeodesic coarse median spaces of
finite rank and at most exponential growth have Property A. This offers an
alternative proof of the fact that mapping class groups have property A.


title: On identities of infinite dimensional Lie superalgebras

abstract:
  We study codimension growth of infinite dimensional Lie superalgebras over an
algebraically closed field of characteristic zero. We prove that if a Lie
superalgebra $L$ is a Grassmann envelope of a finite dimensional simple Lie
algebra then the PI-exponent of $L$ exists and it is a positive integer.


title:
Gauge-covariant decomposition and magnetic monopole for G(2) Yang-Mills
  field

abstract:
  We give a gauge-covariant decomposition of the Yang-Mills field with an
exceptional gauge group $G(2)$, which extends the field decomposition invented
by Cho, Duan-Ge, and Faddeev-Niemi for the $SU(N)$ Yang-Mills field. As an
application of the decomposition, we derive a new expression of the non-Abelian
Stokes theorem for the Wilson loop operator in an arbitrary representation of
$G(2)$. The resulting new form is used to define gauge-invariant magnetic
monopoles in the $G(2)$ Yang-Mills theory. Moreover, we obtain the quantization
condition to be satisfied by the resulting magnetic charge. The method given in
this paper is general enough to be applicable to any semi-simple Lie group
other than $SU(N)$ and $G(2)$.


title:
Critical Temperature Enhancement of Topological Superconductors: A
  Dynamical Mean Field Study

abstract:
  We show that a critical temperature Tc for spin-singlet two-dimensional
superconductivity is enhanced by a cooperation between the Zeeman magnetic
field and the Rashba spin-orbit coupling, where a superconductivity becomes
topologically non-trivial below Tc. The dynamical mean field theory (DMFT) with
the segment-based hybridization-expansion continuous-time quantum Monte Carlo
impurity solver (ct-HYB) is used for accurately evaluating a critical
temperature, without any Fermion sign problem. A strong-coupling approach shows
that spin-flip driven local pair hopping leads to part of this enhancement,
especially effects of the magnetic field. We propose physical settings suitable
for verifying the present calculations, one-atom-layer system on Si(111) and
ionic-liquid based electric double-layer transistors (EDLTs).


title: On the codimension growth of simple color Lie superalgebras

abstract:
  We study polynomial identities of finite dimensional simple color Lie
superalgebras over an algebraically closed field of characteristic zero graded
by the product of two cyclic groups of order $2$. We prove that the
codimensions of identities grow exponentially and the rate of exponent equals
the dimension of the algebra. A similar result is also obtained for graded
identities and graded codimensions.


title: On roughness-induced adhesion enhancement

abstract:
  While adhesion reduction due to roughness is not surprising, roughness
induced adhesion remained a puzzle until recently Guduru and coworkers have
shown a very convincing mechanism to explain both the increase of strength and
of toughness in a sphere with concentric single scale of waviness. Kesari and
coworkers have later shown some very elegant convenient asymptotic expansion of
Guduru's solution. This enhancement is very high and indeed, using Kesari's
solution, it is here shown to depend uniquely on a Johnson parameter for
adhesion of a sinusoidal contact. However, counterintuitively, it leads to
unbounded enhancement for conditions of large roughness for which Johnson
parameter is very low. Guduru postulated that this enhancement should occur
after sufficiently large pressure has been applied to any spherical contact.
Also, that although the enhancement is limited to the JKR regime of large soft
materials with high adhesion, the DMT limit for the smooth sphere is found
otherwise. However, for hard materials, even the DMT limit for the smooth
solids is very hard to observe, which suggest that also adhesion reduction is
yet not well understood.
  The limitations of the assumption of simply connected area is here further
discussed, and a well known model for hard particles in contact with rough
planes due to Rumpf is used to show that in the range where unbounded increase
is predicted, orders of magnitude reduction is instead expected for rigid
solids. We suggest that Guduru's model may be close to an upper bound to
adhesion of rough bodies, while the Rumpf-Rabinovich model may be close to a
lower bound.


title: Optical anisotropy of the Jeff = 1/2 Mott insulator Sr2IrO4

abstract:
  We report the complex dielectric function along and perpendicular to the IrO2
planes in the layered perovskite Sr2IrO4 determined by spectroscopic
ellipsometry in the spectral range from 12 meV to 6 eV. Thin high quality
single crystals were stacked to measure the c-axis optical conductivity. In the
phonon response we identified 10 infrared-active modes polarized within the
basal plane and only four modes polarized along the c-axis, in full agreement
with first-principle lattice dynamics calculations. We also observed a strong
optical anisotropy in the near-infrared spectra arising from direct transitions
between Ir 5d t2g Jeff = 1/2 and Jeff = 3/2 bands, which transition probability
is highly suppressed for light polarized along the c-axis. The spectra are
analyzed and discussed in terms of relativistic LSDA+U band structure
calculations.


title:
On the scaling of functional spaces, from smart cities to cloud
  computing

abstract:
  The study of spacetime, and its role in understanding functional systems has
received little attention in information science. Recent work, on the origin of
universal scaling in cities and biological systems, provides an intriguing
insight into the functional use of space, and its measurable effects. Cities
are large information systems, with many similarities to other technological
infrastructures, so the results shed new light indirectly on the scaling the
expected behaviour of smart pervasive infrastructures and the communities that
make use of them.
  Using promise theory, I derive and extend the scaling laws for cities to
expose what may be extrapolated to technological systems. From the promise
model, I propose an explanation for some anomalous exponents in the original
work, and discuss what changes may be expected due to technological
advancement.


title:
On the existence of three solutions for the Dirichlet problem on the
  Sierpinski gasket

abstract:
  We apply a recently obtained three critical points theorem of B. Ricceri to
prove the existence of at least three solutions of certain two-parameters
Dirichlet problems defined on the Sierpinski gasket. We also show the existence
of at least three nonzero solutions of certain perturbed two-parameters
Dirichlet problems on the Sierpinski gasket, using both the mountain pass
theorem of Ambrosetti-Rabinowitz and that of Pucci-Serrin.


title:
Self-organisation in cellular automata with coalescent particles:
  qualitative and quantitative approaches

abstract:
  This article introduces new tools to study self-organisation in a family of
simple cellular automata which contain some particle-like objects with good
collision properties (coalescence) in their time evolution. We draw an initial
configuration at random according to some initial $\sigma$-ergodic measure
$\mu$, and use the limit measure to descrbe the asymptotic behaviour of the
automata. We first take a qualitative approach, i.e. we obtain information on
the limit measure(s). We prove that only particles moving in one particular
direction can persist asymptotically. This provides some previously unknown
information on the limit measures of various deterministic and probabilistic
cellular automata: 3 and 4-cyclic cellular automata (introduced in [Fis90b]),
one-sided captive cellular automata (introduced in [The04]), N. Fat{\`e}s'
candidate to solve the density classification problem [Fat13], self
stabilization process toward a discrete line [RR15]... In a second time we
restrict our study to to a subclass, the gliders cellular automata. For this
class we show quantitative results, consisting in the asymptotic law of some
parameters: the entry times (generalising [KFD11]), the density of particles
and the rate of convergence to the limit measure.


title: Elementary matrix reduction over Bezout duo rings

abstract:
  A ring $R$ is an elementary divisor ring if every matrix over $R$ admits a
diagonal reduction. We further explore various stable like conditions on a
bezout duo-domain under which it is an elementary divisor domain. Many known
results are thereby generalized to much wider class of rings.


title:
Simulation of Effective Subshifts by Two-dimensional Subshifts of Finite
  Type

abstract:
  In this article we study how a subshift can simulate another one, where the
notion of simulation is given by operations on subshifts inspired by the
dynamical systems theory (factor, projective subaction...). There exists a
correspondence between the notion of simulation and the set of forbidden
patterns. The main result of this paper states that any effective subshift of
dimension d -- that is a subshift whose set of forbidden patterns can be
generated by a Turing machine -- can be obtained by applying dynamical
operations on a subshift of finite type of dimension d + 1 -- a subshift that
can be defined by a finite set of forbidden patterns. This result improves
Hochman's [Hoc09].


title:
Long-Range Dipole-Dipole Interaction and Anomalous F\"{o}rster Energy
  Transfer across Hyperbolic Meta Material

abstract:
  We study radiative energy transfer between a donor-acceptor pair across a
hyperbolic metamaterial slab. We show that similar to a perfect lens a
hyperbolic lens allows for giant energy transfer rates. For a realistic
realization of a hyperbolic multilayer metamaterial we find an enhancement of
up to three orders of magnitude with respect to the transfer rates across a
plasmonic silver film of the same size especially for frequencies which
coincide with the epsilon-near zero and the epsilonnear pole frequencies.
Furthermore, we compare exact results based on the S-matrix method with results
obtained from effective medium theory. Our finding of very large dipole-dipole
interaction at distances of the order of a wavelength has important
consequences for producing radiative heat transfer, quantum entanglement etc.


title: GBLA -- Gr\"obner Basis Linear Algebra Package

abstract:
  This is a system paper about a new GPLv2 open source C library GBLA
implementing and improving the idea of Faug\`ere and Lachartre (GB reduction).
We further exploit underlying structures in matrices generated during Gr\"obner
basis computations in algorithms like F4 or F5 taking advantage of block
patterns by using a special data structure called multilines. Moreover, we
discuss a new order of operations for the reduction process. In various
different experimental results we show that GBLA performs better than GB
reduction or Magma in sequential computations (up to 40% faster) and scales
much better than GB reduction for a higher number of cores: On 32 cores we
reach a scaling of up to 26. GBLA is up to 7 times faster than GB reduction.
Further, we compare different parallel schedulers GBLA can be used with. We
also developed a new advanced storage format that exploits the fact that our
matrices are coming from Gr\"obner basis computations, shrinking storage by a
factor of up to 4. A huge database of our matrices is freely available with
GBLA.


title: A Nash type solution for hemivariational inequality systems

abstract:
  In this paper we prove an existence result for a general class of
hemivariational inequalities systems using the Ky Fan version of KKM theorem
(1984) or the Tarafdar fixed point theorem (1987). As application we give an
infinite dimensional version for existence result of Nash generalized
derivative points introduced recently by Krist\'{a}ly (2010) and also we give
an application to a general hemivariational inequalities system.


title:
Intensity Distribution Function and Statistical Properties of Fast Radio
  Bursts

abstract:
  Fast Radio Bursts (FRBs) are intense radio flashes from the sky that are
characterized by millisecond durations and Jansky-level flux densities. We
carried out a statistical analysis on FRBs discovered. Their mean dispersion
measure, after subtracting the contribution from the interstellar medium of our
Galaxy, is found to be $\sim 660\,\rm pc\,cm^{-3}$, supporting their being from
cosmological origin. Their energy released in radio band spans about two orders
of magnitude, with a mean value of $\sim 10^{39}$ ergs. More interestingly,
although the FRB study is still in a very early phase, the published collection
of FRBs enables us to derive a useful intensity distribution function. For the
16 non-repeating FRBs detected by Parkes telescope and the Green Bank
Telescope, the intensity distribution can be described as $dN/dF_{\rm obs} =
(4.1 \pm 1.3) \times 10^3 \, F_{\rm obs}^{-1.1\pm0.2} \; \rm
sky^{-1}\,day^{-1}$, where $F_{\rm obs}$ is the observed radio fluence in units
of Jy~ms. Here the power-law index is significantly flatter than the expected
value of 2.5 for standard candles distributed homogeneously in a flat Euclidean
space. Based on this intensity distribution function, the Five-hundred-meter
Aperture Spherical radio Telescope (FAST) will be able to detect about 5 FRBs
for every 1000 hours of observation time.


title: Delayed Choice Experiments and the Bohm Approach

abstract:
  The delayed choice experiments of the type introduced by Wheeler and extended
by Englert, Scully, S\"ussmann and Walther [ESSW], and others, have formed a
rich area for investigating the puzzling behaviour of particles undergoing
quantum interference. The surprise provided by the original delayed choice
experiment, led Wheeler to the conclusion that "no phenomenon is a phenomenon
until it is an observed phenomenon", a radical explanation which implied that
"the past has no existence except as it is recorded in the present". However
Bohm, Dewdney and Hiley have shown that the Bohm interpretation gives a
straightforward account of the behaviour of the particle without resorting to
such a radical explanation. The subsequent modifications of this experiment led
both Aharonov and Vaidman and [ESSW] to conclude that the resulting Bohm-type
trajectories in these new situations produce unacceptable properties. For
example, if a cavity is placed in one arm of the interferometer, it will be
excited by a particle travelling down the {\em other} arm. In other words it is
the particle that does {\em not} go through the cavity that gives up its
energy! If this analysis is correct, this behaviour would be truly bizarre and
could only be explained by an extreme non-local transfer of energy that is even
stronger than that required in an EPR-type processes. In this paper we show
that this conclusion is not correct and that if the Bohm interpretation is used
correctly, it gives a {\em local} explanation, which actually corresponds
exactly to the standard quantum mechanics explanation offered by Englert,
Scully, S\"ussmann and Walther [ESSW].


title:
Density analysis of non-Markovian BSDEs and applications to biology and
  finance

abstract:
  In this paper, we provide conditions which ensure that stochastic Lipschitz
BSDEs admit Malliavin differentiable solutions. We investigate the problem of
existence of densities for the first components of solutions to general
path-dependent stochastic Lipschitz BSDEs and obtain results for the second
components in particular cases. We apply these results to both the study of a
gene expression model in biology and to the classical pricing problems in
mathematical finance.


title: Two-bubble nodal solutions for slightly subcritical Fractional Laplacian

abstract:
  In this paper, we consider the existence of nodal solutions with two bubbles
to the slightly subcritical problem with the fractional Laplacian
\begin{equation*} \left\{\aligned &(-\Delta)^su=|u|^{p-1-\varepsilon}u\ \
\mbox{in}\ \Omega &u=0\ \mbox{on}\ \partial\Omega, \endaligned \right.
\end{equation*} where $\Omega$ is a smooth bounded domain in $\mathbb R^N$,
$N>2s$, $0<s<1$, $ p=\frac{N+2s}{N-2s}$ and $\varepsilon>0$ is a small
parameter, which can be seen as a nonlocal analog of the results of Bartsch,
Micheletti and Pistoia (2006) \cite{Bartsch1}.


title: Singular solutions of perturbed logistic-type equations

abstract:
  We are concerned with the qualitative analysis of positive singular solutions
with blow-up boundary for a class of logistic-type equations with slow
diffusion and variable potential. We establish the exact blow-up rate of
solutions near the boundary in terms of Karamata regular variation theory. This
enables us to deduce the uniqueness of the singular solution.


title:
Polarization-transfer measurement to a large-virtuality bound proton in
  the deuteron

abstract:
  Possible differences between free and bound protons may be observed in the
ratio of polarization-transfer components, $P'_x/P'_z$. We report the
measurement of $P'_x/P'_z$, in the $^2\textrm{H}(\vec{e},e^{\prime}\vec{p})n$
reaction at low and high missing momenta. Observed increasing deviation of
$P'_x/P'_z$ from that of a free proton as a function of the virtuality, similar
to that observed in \hefour, indicates that the effect in nuclei is due to the
virtuality of the knock-out proton and not due to the average nuclear density.
The measured differences from calculations assuming free-proton form factors
($\sim10\%$), may indicate in-medium modifications.


title: Designing recipes for auxetic behaviour of 2-d lattices

abstract:
  We present an analytical model to investigate the mechanics of 2-dimensional
lattices composed of elastic beams of non-uniform cross-section. Our approach
is based on reducing a lattice to a single beam subject to the action of a set
of linear and torsional springs, thus allowing the problem to be solved through
a transfer matrix method. We show a non-trivial region of design space that
yields materials with auxetic properties for strains greater than that required
to trigger elastic instability. The critical loading required to make this
transition from positive to negative Poisson's ratio is calculated.
Furthermore, we present lattice parameters that provide direction-dependent
deformation modes offering great tailorability of the mechanical properties of
finite size lattices. Not only is our analytical formulation in good agreement
with the finite element simulation results, but it provides an insight into the
role of the interplay between structure and elastic instability, and gives an
efficient methodology to pursue questions of rational design in the field of
mechanical metamaterials.


title: Collective excitations of massive flavor branes

abstract:
  We study the intersections of two sets of D-branes of different
dimensionalities. This configuration is dual to a supersymmetric gauge theory
with flavor hypermultiplets in the fundamental representation of the gauge
group which live on the defect of the unflavored theory determined by the
directions common to the two types of branes. One set of branes is dual to the
color degrees of freedom, while the other set adds flavor to the system. We
work in the quenched approximation, i.e., where the flavor branes are
considered as probes, and focus specifically on the case in which the quarks
are massive. We study the thermodynamics and the speeds of first and zero sound
at zero temperature and non-vanishing chemical potential. We show that the
system undergoes a quantum phase transition when the chemical potential
approaches its minimal value and we obtain the corresponding non-relativistic
critical exponents that characterize its critical behavior. In the case of
(2+1)-dimensional intersections, we further study alternative quantization and
the zero sound of the resulting anyonic fluid. We finally extend these results
to non-zero temperature and magnetic field and compute the diffusion constant
in the hydrodynamic regime. The numerical results we find match the predictions
by the Einstein relation.


title: Fake projective planes, automorphic forms, exceptional collections

abstract:
  On the projective plane there is a unique cubic root of the canonical bundle
and this root is acyclic. On fake projective planes such root exists and is
unique if there are no 3-torsion divisors (and usually exists, but not unique,
otherwise). Earlier we conjectured that any such cubic root must be acyclic. In
the present note we give two short proofs of this statement and show acyclicity
of some other line bundles on the fake projective planes with at least $9$
automorphisms. Similarly to our earlier work we employ simple representation
theory for non-abelian finite groups. The novelty stems from the idea that if
some line bundle is non-linearizable with respect to a finite abelian group,
then it should be linearized by a finite, \emph{non-abelian}, Heisenberg group.
For the second proof, we also demonstrate vanishing of odd Betti numbers for a
class of abelian covers, and use a linearization of an auxiliary line bundle as
well.


title:
The group of strong Galois objects associated to a cocommutative Hopf
  quasigroup

abstract:
  Let H be a cocommutative faithfully flat Hopf quasigroup in a strict
symmetric monoidal category with equalizers. In this paper we introduce the
notion of (strong) Galois H-object and we prove that the set of isomorphism
classes of (strong) Galois H-objects is a (group) monoid which coincides, in
the Hopf algebra setting, with the Galois group of H-Galois objects introduced
by Chase and Sweedler.


title: Solvability of Dirichlet problem with Integro-differential Operator

abstract:
  This paper studies the solvability of a class of Dirichlet problem associated
with non-linear integro-differential operator. The main ingredient is the
probabilistic construction of continuous supersolution via the identification
of the continuity set of the exit time operators under Skorohod topology.


title: Lifting non-ordinary cohomology classes for SL(3)

abstract:
  In this paper, we present a generalisation of a theorem of David and Rob
Pollack. In 'A construction of rigid analytic cohomology classes for congruence
subgroups of SL(3,Z)', they give a very general argument for lifting ordinary
eigenclasses (with respect to a suitable operator) in the group cohomology of
certain arithmetic groups. With slightly tighter conditions, we prove the same
result for non-ordinary classes. Pollack and Pollack apply their results to the
case of p-ordinary classes in the group cohomology of congruence subgroups for
SL3, constructing explicit overconvergent classes in this setting. As an
application of our results, we give an extension of their results to the case
of non-critical slope classes in the same setting.


title: Compressive Conjugate Directions: Linear Theory

abstract:
  We present a powerful and easy-to-implement iterative algorithm for solving
large-scale optimization problems that involve $L_1$/total-variation (TV)
regularization. The method is based on combining the Alternating Directions
Method of Multipliers (ADMM) with a Conjugate Directions technique in a way
that allows reusing conjugate search directions constructed by the algorithm
across multiple iterations of the ADMM. The new method achieves fast
convergence by trading off multiple applications of the modeling operator for
the increased memory requirement of storing previous conjugate directions. We
illustrate the new method with a series of imaging and inversion applications.


title:
Updated determination of chiral couplings and vacuum condensates from
  hadronic tau decay data

abstract:
  We analyze the lowest spectral moments of the left-right two-point
correlation function, using all known short-distance constraints and the
recently updated ALEPH V-A spectral function from tau decays. This information
is used to determine the low-energy couplings L10 and C87 of chiral
perturbation theory and the lowest-dimensional contributions to the Operator
Product Expansion of the left-right correlator. A detailed statistical analysis
is implemented to assess the theoretical uncertainties, including violations of
quark-hadron duality.


title:
Cosmological dynamics of scalar fields with kinetic corrections: Beyond
  the exponential potential

abstract:
  We expand the dynamical systems investigation of cosmological scalar fields
characterised by kinetic corrections presented in [N. Tamanini, Phys. Rev. D 89
(2014) 083521]. In particular we do not restrict the analysis to exponential
potentials only, but we consider arbitrary scalar field potentials and derive
general results regarding the corresponding cosmological dynamics. Two specific
potentials are then used as examples to show how these models can be employed
not only to describe dark energy, but also to achieve dynamical crossing of the
phantom barrier at late times. Stability and viability issues at the classical
level are also discussed.


title: Measuring Plank constant with colour LEDs and compact disk

abstract:
  This problem was given on the Open Experimental Physics Olympiad (OEPO) "The
day of the photon" on 25 April 2015. The Olympiad was a part of the celebration
of the International Year of Light (IYL)
http://www.light2015.org/Home/Event-Programme/2015/Competition/Bulgaria-Second-Experimental-Physics-Olympiad--25-April-2015-in-Sofia.-The-Day-of-the-Photon-in-the-International-Year-of-the-Light.html
and was organized by the Sofia Branch of the Union of Physicist in Bulgaria and
the Regional Society of Physicists of Strumica, Macedonia.


title: Reentrance of disorder in the anisotropic shuriken Ising model

abstract:
  For a material to order upon cooling is common sense. What is more seldom is
for disorder to reappear at lower temperature, which is known as reentrant
behavior. Such resurgence of disorder has been observed in a variety of
systems, ranging from Rochelle salts to nematic phases in liquid crystals.
Frustration is often a key ingredient for reentrance mechanisms. Here we shall
study a frustrated model, namely the anisotropic shuriken lattice, which offers
a natural setting to explore an extension of the notion of reentrance between
magnetic disordered phases. By tuning the anisotropy of the lattice, we open a
window in the phase diagram where magnetic disorder prevails down to zero
temperature. In this region, the competition between multiple disordered ground
states gives rise to a double crossover where both the low- and
high-temperature regimes are less correlated than the intervening classical
spin liquid. This reentrance of disorder is characterized by an entropy
plateau, a multi-step Curie law crossover and a rather complex diffuse
scattering in the static structure factor. Those results are confirmed by
complementary numerical and analytical methods: Monte Carlo simulations,
Husimi-tree calculations and an exact decoration-iteration transformation.


title:
Constraints on the location of a possible 9th planet derived from the
  Cassini data

abstract:
  To explain the unusual distribution of Kuiper Belt objects, several authors
have advocated the existence of a super-Earth planet in the outer solar system.
It has recently been proposed that a 10 M$_{\oplus}$ object with an orbit of
700 AU semi major axis and 0.6 eccentricity can explain the observed
distribution of Kuiper Belt objects around Sedna. Here we use the INPOP
planetary ephemerides model as a sensor for testing for an additional body in
the solar system. We test the possibility of adding the proposed planet without
increasing the residuals of the planetary ephemerides, fitted over the whole
INPOP planetary data sample. We demonstrate that the presence of such an object
is not compatible with the most sensitive data set, the Cassini radio ranging
data, if its true anomaly is in the intervals $[-130^\circ:-100^\circ]$ or
$[-65^\circ : 85^\circ]$. Moreover, we find that the addition of this object
can reduce the Cassini residuals, with a most probable position given by a true
anomaly $v = {117.8^\circ}^{ + 11^\circ}_{ - 10^\circ} $.


title: Nonlinear quantum optics mediated by Rydberg interactions

abstract:
  By mapping the strong interaction between Rydberg excitations in ultra-cold
atomic ensembles onto single photons via electromagnetically induced
transparency, it is now possible to realize a nonlinear optical medium which
exhibits a strong optical nonlinearity at the level of individual photons. We
review the theoretical concepts and the experimental state-of-the-art of this
exciting new field, and discuss first applications in the field of all-optical
quantum information processing.


title:
Comparison of magneto-optical properties of various excitonic complexes
  in CdTe and CdSe self-assembled quantum dots

abstract:
  We present a comparative study of two self-assembled quantum dot (QD) systems
based on II-VI compounds: CdTe/ZnTe and CdSe/ZnSe. Using magneto-optical
techniques we investigated a large population of individual QDs. The systematic
photoluminescence studies of emission lines related to the recombination of
neutral exciton X, biexciton XX, and singly charged excitons (X$^+$, X$^-$)
allowed us to determine average parameters describing CdTe QDs (CdSe QDs): X-XX
transition energy difference 12 meV (24 meV); fine-structure splitting
$\delta_{1}=$0.14 meV ($\delta_{1}=$0.47 meV); $g$-factor $g=$2.12 ($g=$1.71);
diamagnetic shift $\gamma=$2.5 $\mu$eV$/$T$^{2}$ ($\gamma=$1.3
$\mu$eV$/$T$^{2}$). We find also statistically significant correlations between
various parameters describing internal structure of excitonic complexes.


title: About a theorem of Wiener on the Bessel-Kingman Hypergroup

abstract:
  A theorem of Wiener on the circle group was strengthened and extended by
Fournier in [2] to locally compact abelian groups and extended further to the
Bessel-Kingman hypergroup with parameter {\alpha} = 1 / 2 by
Bloom/Fournier/Leinert in [1]. We further extend this theorem to Bessel-Kingman
hypergroups with parameter {\alpha} > 1 / 2 .


title:
Renormalization group flow of the Luttinger-Ward functional: conserving
  approximations and application to the Anderson impurity model

abstract:
  We study the renormalization group flow of the Luttinger-Ward functional and
of its two-particle irreducible vertex functions, given a cut-off in the
two-particle interaction. We derive a conserving approximation to the flow and
relate it to the fluctuation exchange approximation as well as to
non-conserving approximations introduced in an earlier publication ctuation
exchange approximation as well as to nonconserving approximations introducen
[J. F. Rentrop, S. G. Jakobs, and V. Meden, J. Phys. A: Math. Theor. 48, 145002
(2015)]. We apply the different approximate flow equations to the single
impurity Anderson model in thermal equilibrium at vanishing temperature.
Numerical results for the effective mass, the spin susceptibility, the charge
susceptibility, and the linear conductance reflect the similarity of the
methods to the fluctuation exchange approximation. We find the majority of the
approximations to deviate stronger from the exact results than one-particle
irreducible functional renormalization group schemes. However, we identify a
simple static two-particle irreducible flow scheme which performs remarkably
well and produces an exponential Kondo-like scale in the renormalized level
position.


title:
Asymptotic Analysis of a Viscous Fluid in a Curved Pipe with Elastic
  Walls

abstract:
  This communication is devoted to the presentation of our recent results
regarding the asymptotic analysis of a viscous flow in a tube with elastic
walls. This study can be applied, for example, to the blood flow in an artery.
With this aim, we consider the dynamic problem of the incompressible flow of a
viscous fluid through a curved pipe with a smooth central curve. Our analysis
leads to obtain an one dimensional model via singular perturbation of the
Navier-Stokes system as $\varepsilon$, a non dimensional parameter related to
the radius of cross-section of the tube, tends to zero. We allow the radius
depend on tangential direction and time, so a coupling with an elastic or
viscoelastic law on the wall of the pipe is possible.
  To perform the asymptotic analysis, we do a change of variable to a reference
domain where we assume the existence of asymptotic expansions on $\varepsilon$
for both velocity and pressure which, upon substitution on Navier-Stokes
equations, leads to the characterization of various terms of the expansion.
This allows us to obtain an approximation of the solution of the Navier-Stokes
equations.


title: Canonical ensemble in non-extensive statistical mechanics when q>1

abstract:
  The non-extensive statistical mechanics has been used to describe a variety
of complex systems. The maximization of entropy, often used to introduce the
non-extensive statistical mechanics, is a formal procedure and does not easily
leads to physical insight. In this article we investigate the canonical
ensemble in the non-extensive statistical mechanics by considering a small
system interacting with a large reservoir via short-range forces and assuming
equal probabilities for all available microstates. We concentrate on the
situation when the reservoir is characterized by generalized entropy with
non-extensivity parameter q>1. We also investigate the problem of divergence in
the non-extensive statistical mechanics occurring when q>1 and show that there
is a limit on the growth of the number of microstates of the system that is
given by the same expression for all values of q.


title:
Sharp $L^{p}$-Boundedness of Oscillatory Integral Operators with
  Polynomial Phases

abstract:
  In this paper, we shall prove the $L^{p}$ endpoint decay estimates of
oscillatory integral operators with homogeneous polynomial phases $S$ in
$\mathbb{R} \times \mathbb{R}$. As a consequence, sharp $L^{p}$ decay estimates
are also obtained when polynomial phases have the form $S(x^{m_{1}},y^{m_{2}})$
with $m_1$ and $m_2$ being positive integers.


title: Monopole-center vortex chains in $SU(2)$ gauge theory

abstract:
  We study the relation between center vortex fluxes and monopole fluxes for
$SU(2)$ gauge group in a model. This model is the same as thick center vortex
model but we use monopole-antimonopole configurations instead of center
vortices in the vacuum. Monopole-antimonopole configurations are line-like
similar to center vortices. The group factor and potential for the fundamental
representation of these configurations are studied and compared with those of
center vortices. As a result, we obtain monopole-vortex chains which appear in
lattice Monte Carlo simulations, as well. If these monopole-vortex chains
intersect the large Wilson loop in two points, screening is observed for the
potential in the fundamental representation at large distances and confinement
is observed when one leg of the chain intersects the Wilson loop.


title:
The slow collisional ExB ion drift characterized as the major
  instability mechanism of a poorly magnetized plasma column with an
  inward-directed radial electric field

abstract:
  The low-frequency instability of a cylindrical poorly magnetized plasma with
an inward-directed radial electric field is studied changing the gas pressure
and the ion cyclotron frequency. The unstable frequency always decreases when
the gas pressure is increased indicating collisional effects. At a fixed
pressure, the unstable frequency increases with the magnetic field when the
B-field is low and decreases at larger magnetic field strength. We find that
the transition between these two regimes is obtained when the ion cyclotron
frequency equals the ion-neutrals collision frequency. This is in agreement
with the theory of the slow-ion drift instability induced by the collisional
slowing of the electric ion drift (A. Simon, Phys. Fluids 6, 382, (1963).


title:
On the Multilinear Fractional Integral Operators with Correlation
  Kernels

abstract:
  In this paper, we study a class of multilinear fractional integral operators
which have correlation kernels $\prod_{1\leq i<j \leq
k}|x_i-x_j|^{-\alpha_{ij}}$. The necessary and sufficient conditions are
obtained under which these oprators are bounded from $L^{p_1}\times \cdots
\times L^{p_k}$ into $L^q$. As a consequence, we also get the endpoint
estimates from $L^{p_1}\times \cdots \times L^{p_k}$ to $BMO$ of these
operators.


title:
Harmonic analysis on the space of $p$-adic unitary hermitian matrices,
  including dyadic case

abstract:
  We are interested in the harmonic analysis on $p$-adic homogeneous spaces
based on spherical functions. In the present paper, we investigate the space
$X$ of unitary hermitian matrices of size $m$ over a ${\mathfrak p}$-adic field
$k$ and give unified description including dyadic case, which is a continuation
of our previous papers on non-dyadic case. The space becomes complicated when
$e = v_\pi(2) > 0$. First we introduce a typical spherical function
$\omega(x;z)$ on $X$, and study their functional equations, which depend on $m$
and $e$, we give an explicit formula for $\omega(x;z)$, where Hall-Littlewood
polynomials of type $C_n$ appear as a main term with different specialization
according as $m = 2n$ or $2n+1$, but independent of $e$. By spherical
transform, we show the Schwartz space ${\mathcal S}(K \backslash X)$ is a free
Hecke algebra ${\mathcal H}(G,K)$-module of rank $2^n$, and give
parametrization of all the spherical functions on $X$ and the explicit
Plancherel formula on ${\mathcal S}(K \backslash X)$. The Plancherel measure
does not depend on $e$, but the normalization of $G$-invariant measure on $X$
depends.


title:
Comment on 'Absolute negative mobility in a one-dimensional overdamped
  system'

abstract:
  Recently Ru-Yin Chen et al. (Phys. Lett. A 379 (2015) 2169-2173) presented
results on the absolute negative mobility (ANM) in a one-dimensional overdamped
system and claimed that a new minimal model of ANM was proposed. We suggest
that the authors introduced a mistake in their calculations. Then we perform a
precise numerical simulation of the corresponding Langevin equation to show
that the ANM phenomenon does not occur in the considered system.


title:
The $N_f=2$ QCD chiral phase transition with Wilson fermions at zero and
  imaginary chemical potential

abstract:
  The order of the thermal phase transition in the chiral limit of Quantum
Chromodynamics (QCD) with two dynamical flavors of quarks is a long-standing
issue and still not known in the continuum limit. Whether the transition is
first or second order has important implications for the QCD phase diagram and
the existence of a critical endpoint at finite densities. We follow a recently
proposed approach to explicitly determine the region of first order chiral
transitions at imaginary chemical potential, where it is large enough to be
simulated, and extrapolate it to zero chemical potential with known critical
exponents. Using unimproved Wilson fermions on coarse $N_t=4$ lattices, the
first order region turns out to be so large that no extrapolation is necessary.
The critical pion mass $m_\pi^c\approx 560$ MeV is by nearly a factor 10 larger
than the corresponding one using staggered fermions. Our results are in line
with investigations of three-flavour QCD using improved Wilson fermions and
indicate that the systematic error on the two-flavour chiral transition is
still of order 100\%.


title: Free energy of ligand removal in the metal-organic framework UiO-66

abstract:
  We report an investigation of the "missing-linker phenomenon" in the Zr-based
metal-organic framework UiO-66 using atomistic forcefield and quantum chemical
methods. For a vacant benzene dicarboxylate ligand, the lowest energy charge
capping mechanism involves acetic acid or Cl-/H2O. The calculated defect free
energy of formation is remarkably low, consistent with the high defect
concentrations reported experimentally. A dynamic structural instability is
identified for certain higher defect concentrations. In addition to the changes
in material properties upon defect formation, we assess the formation of
molecular aggregates, which provide an additional driving force for ligand
loss. These results are expected to be of relevance to a wide range of
metal-organic frameworks.


title: Biharmonic submanifolds of generalized space forms

abstract:
  We consider biharmonic submanifolds in both generalized complex and Sasakian
space forms. After giving the biharmonicity conditions for submanifolds in
these spaces, we study different particular cases for which we obtain curvature
estimates. We consider curves, complex and Lagrangian surfaces and
hypersurfaces for the generalized complex space form as well as hypersurfaces,
invariant and anti-invariant submanifolds in case of generalized Sasakian space
form.


title: Mechanism of Threshold Elongation of DNA Macromolecule

abstract:
  The mechanism of threshold elongation (overstretching) of DNA macromolecules
under the action of external force is studied within the framework of
phenomenological approach. When considering the task it is taken into account
that double-stranded DNA is a polymorphic macromolecule with a set of
metastable states. Accordingly to proposed mechanism, DNA threshold elongation
can take place as a cooperative structural transition of macromolecule to
metastable form, which is stabilized by the external force. For the description
of DNA overstretching, the model included external (stretching) and internal
(conformation) displacement components is constructed. As assumed, both
components are coupled on the pathway of double helix transformations. It is
shown, that under force action DNA deformation proceeds in two stages. First
one is the restructuring of the double helix, which leads to formation of
conformational bistability in DNA macromolecule. On the second stage, the
conformational transition and the deformation induced by it consistently cover
the macromolecule as a threshold process. The comparison of calculated
characteristics of DNA overstretching process with experimental data shows good
agreement. Analysis of the results obtained, together with the available
literature data allow to conclude, that overstretching transition in the double
helix is dynamical process and can spread in DNA chain. In the same time, in
DNA with A$\cdot$T-rich content due to large dissipation the overstretching
process leads to force induced melting transition, and should have nearly
static character.


title:
Optimal Low-Complexity Self-Interference Cancellation for Full-Duplex
  MIMO Small Cells

abstract:
  Self-interference (SI) significantly limits the performance of full-duplex
(FD) radio devices if not properly cancelled. State-of-the-art SI cancellation
(SIC) techniques at the receive chain implicitly set an upper bound on the
transmit power of the device. This paper starts from this observation and
proposes a transmit beamforming design for FD multiple-antenna radios that: i)
leverages the inherent SIC capabilities at the receiver and the channel state
information; and ii) exploits the potential of multiple antennas in terms of
spatial SIC. The proposed solution not only maximizes the throughput while
complying with the SIC requirements of the FD device, but also enjoys a very
low complexity that allows it to outperform state-of-the-art counterparts in
terms of processing time and power requirements. Numerical results show that
our transmit beamforming design achieves significant gains with respect to
applying zero-forcing to the SI channel when the number of transmit antennas is
small to moderate, which makes it particularly appealing for FD small-cell base
stations.


title:
Spin-isospin transitions in chromium isotopes within the quasiparticle
  random phase approximation

abstract:
  Beta decay and electron capture on isotopes of chromium are advocated to play
a key role in the stellar evolution process. In this paper we endeavor to study
charge-changing transitions for 24 isotopes of chromium ($^{42-65}$Cr). These
include neutron-rich and neutron-deficient isotopes of chromium. Three
different models from the QRPA genre, namely the pn-QRPA, the Pyatov method
(PM) and the Schematic model (SM), were selected to calculate and study the
Gamow-Teller (GT) transitions in chromium isotopes. The SM was employed
separately in the particle-particle ($pp$) and $pp$ + particle-hole ($ph$)
channels. To study the effect of deformation, the SM was first used assuming
the nuclei to be spherical and later to be deformed. The PM was used both in
$pp$ and $pp$ + $ph$ channels but only for the case of spherical nuclei. The
pn-QRPA calculation was done by considering both $pp$ and $ph$ forces and
taking deformation of nucleus into consideration. A recent study proved this
version of pn-QRPA to be the best for calculation of GT strength distributions
amongst the QRPA models. The pn-QRPA model calculated GT distributions had
low-lying centroids and small widths as compared to other QRPA models. Our
calculation results were also compared with other theoretical models and
measurements wherever available. Our results are in decent agreement with
previous measurements and shell model calculations.


title: Quantifying noisy attractors: from heteroclinic to excitable networks

abstract:
  Attractors of dynamical systems may be networks in phase space that can be
heteroclinic (where there are dynamical connections between simple invariant
sets) or excitable (where a perturbation threshold needs to be crossed to a
dynamical connection between "nodes"). Such network attractors can display a
high degree of sensitivity to noise both in terms of the regions of phase space
visited and in terms of the sequence of transitions around the network. The two
types of network are intimately related---one can directly bifurcate to the
other.
  In this paper we attempt to quantify the effect of additive noise on such
network attractors. Noise increases the average rate at which the networks are
explored, and can result in "macroscopic" random motion around the network. We
perform an asymptotic analysis of local behaviour of an escape model near
heteroclinic/excitable nodes in the limit of noise $\eta\rightarrow 0^+$ as a
model for the mean residence time $T$ near equilibria.
  We also explore transition probabilities between nodes of the network in the
presence of anisotropic noise. For low levels of noise, numerical results
suggest that a (heteroclinic or excitable) network can approximately realise
any set of transition probabilities and any sufficiently large mean residence
times at the given nodes. We show that this can be well modelled in our example
network by multiple independent escape processes, where the direction of first
escape determines the transition. This suggests that it is feasible to design
noisy network attractors with arbitrary Markov transition probabilities and
residence times.


title:
Ordonnancement d'entit\'es pour la rencontre du web des documents et du
  web des donn\'ees

abstract:
  The advances of the Linked Open Data (LOD) initiative are giving rise to a
more structured web of data. Indeed, a few datasets act as hubs (e.g., DBpedia)
connecting many other datasets. They also made possible new web services for
entity detection inside plain text (e.g., DBpedia Spotlight), thus allowing for
new applications that will benefit from a combination of the web of documents
and the web of data. To ease the emergence of these new use-cases, we propose a
query-biased algorithm for the ranking of entities detected inside a web page.
Our algorithm combine link analysis with dimensionality reduction. We use
crowdsourcing for building a publicly available and reusable dataset on which
we compare our algorithm to the state of the art. Finally, we use this
algorithm for the construction of semantic snippets for which we evaluate the
usability and the usefulness with a crowdsourcing-based approach.


title:
The role of the pressure in the partial regularity theory for weak
  solutions of the Navier--Stokes equations

abstract:
  We study the role of the pressure in the partial regularity theory for weak
solutions of the Navier--Stokes equations. By introducing the notion of
dissipative solutions, due to Duchon \& Robert, we will provide a
generalization of the Caffarelli, Kohn and Nirenberg theory. Our approach gives
a new enlightenment of the role of the pressure in this theory in connection to
Serrin's local regularity criterion.


title: Toward virtual ceramic composites

abstract:
  A first step toward a multi-scale and multi-physic model --a virtual
material-- for self-healing ceramic matrix composites is presented. Each
mechanism --mechanical, chemical-- that act on the material's lifetime at a
given scale --fibre, yarn-- is introduced in a single modeling framework, aimed
at providing powerful prediction tools.


title: Toward a virtual material for lifetime prediction of CMCs

abstract:
  A first version of a multi-scale, multi-physic hybrid model --called virtual
material-- for predictions on Self-Healing Ceramic Matrix Composite's (CMCs)
lifetime is presented. The model has a mechanical and a chemical part, which
are presented here in their actual state of development. The mechanical part
provides precise data for the chemical models through an hybrid --melting
continuum damage macro model discrete crack surfaces-- representation of the
morphology of the crack network at yarn scale. The chemical part should provide
predictions on the structure's lifetime using a model of the self-healing
process, not yet achieved then not presented here, and a model of fiber
sub-critical failure under mechanical and chemical load.


title:
A probabilistic representation for the value of zero-sum differential
  games with incomplete information on both sides

abstract:
  We prove that for a class of zero-sum differential games with incomplete
information on both sides, the value admits a probabilistic representation as
the value of a zero-sum stochastic differential game with complete information,
where both players control a continuous martingale. A similar representation as
a control problem over discontinuous martingales was known for games with
incomplete information on one side (see Cardaliaguet-Rainer [8]), and our
result is a continuous-time analog of the so called splitting-game introduced
in Laraki [20] and Sorin [27] in order to analyze discrete-time models. It was
proved by Cardaliaguet [4, 5] that the value of the games we consider is the
unique solution of some Hamilton-Jacobi equation with convexity constraints.
Our result provides therefore a new probabilistic representation for solutions
of Hamilton-Jacobi equations with convexity constraints as values of stochastic
differential games with unbounded control spaces and unbounded volatility.


title: Nonlinear waves in coherently coupled Bose-Einstein condensates

abstract:
  We consider a quasi-one-dimensional two-component Bose-Einstein condensate
subject to a coherent coupling between its components, such as realized in
spin-orbit coupled condensates. We study how nonlinearity modifies the dynamics
of the elementary excitations. The spectrum has two branches which are affected
in different ways. The upper branch experiences a modulational instability
which is stabilized by a long wave-short wave resonance with the lower branch.
The lower branch is stable. In the limit of weak nonlinearity and small
dispersion it is described by a Korteweg-de Vries equation or by the Gardner
equation, depending on the value of the parameters of the system.


title: Three-dimensional hydrodynamic simulations of L2 Puppis

abstract:
  Recent observations of the L2 Puppis system suggest that this Mira-like
variable may be in the early stages of forming a bipolar planetary nebula (PN).
As one of nearest and brightest AGB stars, thought be a binary, L2 Puppis
serves as a benchmark object for studying the late-stages of stellar evolution.
We perform global, three-dimensional, adaptive-mesh-refinement hydrodynamic
simulations of the L2 Puppis system with AstroBEAR. We use the radiative
transfer code RADMC-3D to construct the broad-band spectral-energy-distribution
(SED) and synthetic observational images from our simulations. Given the
reported binary parameters, we are able to reproduce the current observational
data if a short pulse of dense material is released from the AGB star with a
velocity sufficient to escape the primary but not the binary. Such a situation
could result from a thermal pulse, be induced by a periastron passage of the
secondary, or could be launched if the primary ingests a planet.


title:
Impact of leptonic $\tau$ decays on the distribution of $B \to P
  \mu\bar\nu$ decays

abstract:
  We calculate the fully-differential rate of the decays $B\to P\tau(\to
\mu\bar\nu\nu)\bar\nu$ where $P = D,\pi$, which is a background to the
semimuonic decays $B\to P\mu\bar\nu$. The decays with a $3\nu$ final state can
have a sizeable impact on the experimental analyses of the ratios $R_D$ and
$R_\pi$, depending on the event selection in the analysis. We outline a
strategy which permits the extraction of $R_P \mathcal{B}(\tau \to
\mu\bar\nu\nu)$ from the neutrino-inclusive rate. Our analytic results can also
be used to test both existing and upcoming experimental analyses. We further
provide Monte Carlo samples of the 5D rate of the neutrino-inclusive decays
$B\to P\mu X_{\bar\nu}$.


title: Monge points, Euler lines, and Feuerbach spheres in Minkowski spaces

abstract:
  It is surprising, but an established fact that the field of Elementary
Geometry referring to normed spaces (= Minkowski spaces) is not a
systematically developed discipline. There are many natural notions and
problems of elementary and classical geometry that were never investigated in
this more general framework, although their Euclidean subcases are well known
and this extended viewpoint is promising. An example is the geometry of
simplices in non-Euclidean normed spaces; not many papers in this direction
exist. Inspired by this lack of natural results on Minkowskian simplices, we
present a collection of new results as non-Euclidean generalizations of
well-known fundamental properties of Euclidean simplices. These results refer
to Minkowskian analogues of notions like Euler line, orthocentricity, Monge
point, and Feuerbach sphere of a simplex in a normed space. In addition, we
derive some related results on polygons (instead of triangles) in normed
planes.


title:
Recurrent delocalization and quasi-equilibration of photons in coupled
  circuit QED systems

abstract:
  We explore the photon population dynamics in two coupled circuit QED systems.
For a sufficiently weak inter-cavity photon hopping, as the photon-cavity
coupling increases, the dynamics undergoes double transitions first from a
delocalized to a localized phase and then from the localized to another
delocalized phase. The latter delocalized phase is distinguished from the
former one; instead of oscillating between the two cavities, the photons
rapidly quasi-equilibrate over the two cavities. These intrigues are attributed
to an interplay between two qualitatively distinctive nonlinear behaviors of
the circuit QED systems in the utrastrong coupling regime, whose distinction
has been widely overlooked.


title: Vacuum energy in some particular quantum field theories

abstract:
  We study the properties of a class of quantum field theories endowed with an
equal number of anti commuting and commuting field variables, the most common
example being the supersymmetric models. Based on the scaling properties of the
partition function we find that these theories have the quantum energy momentum
tensor associated to dilatations and thus the vacuum energy equal to zero.


title: Magnetic Solitons in a Binary Bose-Einstein Condensate

abstract:
  We study solitary waves of polarization (magnetic solitons) in a
two-component Bose gas with slightly unequal repulsive intra- and interspin
interactions. In experimentally relevant conditions we obtain an analytical
solution which reveals that the width and the velocity of magnetic solitons are
explicitly related to the spin healing length and the spin sound velocity of
the Bose mixture, respectively. We calculate the profiles, the energy and the
effective mass of the solitons in the absence of external fields and
investigate their oscillation in a harmonic trap where the oscillation period
is calculated as a function of the oscillation amplitude. The stability of
magnetic solitons in two dimensions and the conditions for their experimental
observation are also briefly discussed.


title: Gaussian polytopes: a cumulant-based approach

abstract:
  The random convex hull of a Poisson point process in $\mathbb{R}^d$ whose
intensity measure is a multiple of the standard Gaussian measure on
$\mathbb{R}^d$ is investigated. The purpose of this paper is to invent a new
viewpoint on these Gaussian polytopes that is based on cumulants and the
general large deviation theory of Saulis and Statulevi\v{c}ius. This leads to
new and powerful concentration inequalities, moment bounds,
Marcinkiewicz-Zygmund-type strong laws of large numbers, central limit theorems
and moderate deviation principles for the volume and the face numbers.
Corresponding results are also derived for the empirical measures induced by
these key geometric functionals, taking thereby care of their spatial profiles.


title: Large age-gap face verification by feature injection in deep networks

abstract:
  This paper introduces a new method for face verification across large age
gaps and also a dataset containing variations of age in the wild, the Large
Age-Gap (LAG) dataset, with images ranging from child/young to adult/old. The
proposed method exploits a deep convolutional neural network (DCNN) pre-trained
for the face recognition task on a large dataset and then fine-tuned for the
large age-gap face verification task. Finetuning is performed in a Siamese
architecture using a contrastive loss function. A feature injection layer is
introduced to boost verification accuracy, showing the ability of the DCNN to
learn a similarity metric leveraging external features. Experimental results on
the LAG dataset show that our method is able to outperform the face
verification solutions in the state of the art considered.


title: Moduli spaces of $\Lambda$-modules on abelian varieties

abstract:
  We study the moduli space $\mathbf{M}_X(\Lambda, n)$ of semistable
$\Lambda$-modules of vanishing Chern classes over an abelian variety $X$, where
$\Lambda$ belongs to a certain subclass of $D$-algebras. In particular, for
$\Lambda = \mathcal{D}_X$ (resp. $\Lambda = \mathrm{Sym}^\bullet \mathcal{T}X$)
we obtain a description of the moduli spaces of flat connections (resp. Higgs
bundles).
  We give a description of $\mathbf{M}_X(\Lambda, n)$ in terms of a symmetric
product of a certain fibre bundle over the dual abelian variety $\hat{X}$. We
also give a moduli interpretation to the associated Hilbert scheme as the
classifying space of $\Lambda$-modules with extra structure. Finally, we study
the non-abelian Hodge theory associated to these new moduli spaces.


title:
Mass-radius spirals for steady state families of the Vlasov-Poisson
  system

abstract:
  We consider spherically symmetric steady states of the Vlasov-Poisson system,
which describe equilibrium configurations of galaxies or globular clusters. If
the microscopic equation of state, i.e., the dependence of the steady state on
the particle energy (and angular momentum) is fixed, a one-parameter family of
such states is obtained. In the polytropic case the mass of the state along
such a one-parameter family is a monotone function of its radius. We prove that
for the King, Woolley-Dickens, and related models this mass-radius relation
takes the form of a spiral.


title: Quantum Entanglement Percolation

abstract:
  Quantum communication demands efficient distribution of quantum entanglement
across a network of connected partners. The search for efficient strategies for
the entanglement distribution may be based on percolation theory, which
describes evolution of network connectivity with respect to some network
parameters. In this framework, the probability to establish perfect
entanglement between two remote partners decays exponentially with the distance
between them before the percolation transition point, which unambiguously
defines percolation properties of any classical network or lattice. Here we
introduce quantum networks created with local operations and classical
communication, which exhibit non-classical percolation transition points
leading to the striking communication advantages over those offered by the
corresponding classical networks. We show, in particular, how to establish
perfect entanglement between any two nodes in the simplest possible network --
the 1D chain -- using imperfect entangled pairs of qubits.


title:
Deterministic particle approximation of the Hughes model in one space
  dimension

abstract:
  In this paper we present a new approach to the solution to a generalized
version of Hughes' models for pedestrian movements based on a follow-the-leader
many particle approximation. In particular, we provide a rigorous global
existence result under a smallness assumption on the initial data ensuring that
the trace of the solution along the turning curve is zero for all positive
times. We also focus shortly on the approximation procedure for symmetric data
and Riemann type data. Two different numerical approaches are adopted for the
simulation of the model, namely the proposed particle method and a Godunov type
scheme. Several numerical tests are presented, which are in agreement with the
theoretical prediction.


title: Structural Complexity Of Quantum Networks

abstract:
  Quantum network is a set of nodes connected with channels, through which the
nodes communicate photons and classical information. Classical structural
complexity of a quantum network may be defined through its physical structure,
i.e. mutual position of nodes and channels connecting them. We show here that
the classical structural complexity of a quantum network does not restrict the
structural complexity of entanglement graphs, which may be created in the
quantum network with local operations and classical communication. We show, in
particular, that 1D quantum network can simulate both simple entanglement
graphs such as lattices and random graphs and complex small-world graphs.


title:
Multiscale Analysis of Information Dynamics for Linear Multivariate
  Processes

abstract:
  In the study of complex physical and physiological systems represented by
multivariate time series, an issue of great interest is the description of the
system dynamics over a range of different temporal scales. While
information-theoretic approaches to the multiscale analysis of complex dynamics
are being increasingly used, the theoretical properties of the applied measures
are poorly understood. This study introduces for the first time a framework for
the analytical computation of information dynamics for linear multivariate
stochastic processes explored at different time scales. After showing that the
multiscale processing of a vector autoregressive (VAR) process introduces a
moving average (MA) component, we describe how to represent the resulting VARMA
process using state-space (SS) models and how to exploit the SS model
parameters to compute analytical measures of information storage and
information transfer for the original and rescaled processes. The framework is
then used to quantify multiscale information dynamics for simulated
unidirectionally and bidirectionally coupled VAR processes, showing that
rescaling may lead to insightful patterns of information storage and transfer
but also to potentially misleading behaviors.


title: On Edge Caching with Secrecy Constraints

abstract:
  In this paper we investigate the problem of optimal cache placement under
secrecy constraints in heterogeneous networks, where small-cell base stations
are equipped with caches to reduce the overall backhaul load. For two models
for eavesdropping attacks, we formally derive the necessary conditions for
secrecy and we derive the corresponding achievable backhaul rate. In particular
we formulate the optimal caching schemes with secrecy constraints as a convex
optimization problem. We then thoroughly investigate the backhaul rate
performance of the heterogeneous network with secrecy constraints using
numerical simulations. We compare the system performance with and without
secrecy constraints and we analyze the influence of the system parameters, such
as the file popularity, size of the library files and the capabilities of the
small-cell base stations, on the overall performance of our optimal caching
strategy. Our results highlight the considerable impact of the secrecy
requirements on the overall caching performance of the network.


title: Depth-Based Object Tracking Using a Robust Gaussian Filter

abstract:
  We consider the problem of model-based 3D-tracking of objects given dense
depth images as input. Two difficulties preclude the application of a standard
Gaussian filter to this problem. First of all, depth sensors are characterized
by fat-tailed measurement noise. To address this issue, we show how a recently
published robustification method for Gaussian filters can be applied to the
problem at hand. Thereby, we avoid using heuristic outlier detection methods
that simply reject measurements if they do not match the model. Secondly, the
computational cost of the standard Gaussian filter is prohibitive due to the
high-dimensional measurement, i.e. the depth image. To address this problem, we
propose an approximation to reduce the computational complexity of the filter.
In quantitative experiments on real data we show how our method clearly
outperforms the standard Gaussian filter. Furthermore, we compare its
performance to a particle-filter-based tracking method, and observe comparable
computational efficiency and improved accuracy and smoothness of the estimates.


title:
Significant crosstalk reduction using all-dielectric CMOS-compatible
  metamaterials

abstract:
  A recent computational result suggests that highly confined modes can be
realized by all-dielectric metamaterials (S. Jahani et. al., Optica 1, 96
(2014)). This substantially decreases crosstalk between dielectric waveguides,
paving the way for high-density photonic circuits. Here, we experimentally
demonstrate, on a standard silicon-on-insulator (SOI) platform, that using a
simple metamaterial between two silicon strip waveguides results in about a
10-fold increase in coupling length. The proposed structure may lead to
significant reduction in the size of devices in silicon photonics.