title:
The Open Connectome Project Data Cluster: Scalable Analysis and Vision
  for High-Throughput Neuroscience

abstract:
  We describe a scalable database cluster for the spatial analysis and
annotation of high-throughput brain imaging data, initially for 3-d electron
microscopy image stacks, but for time-series and multi-channel data as well.
The system was designed primarily for workloads that build connectomes---neural
connectivity maps of the brain---using the parallel execution of computer
vision algorithms on high-performance compute clusters. These services and
open-science data sets are publicly available at http://openconnecto.me.
  The system design inherits much from NoSQL scale-out and data-intensive
computing architectures. We distribute data to cluster nodes by partitioning a
spatial index. We direct I/O to different systems---reads to parallel disk
arrays and writes to solid-state storage---to avoid I/O interference and
maximize throughput. All programming interfaces are RESTful Web services, which
are simple and stateless, improving scalability and usability. We include a
performance evaluation of the production system, highlighting the effectiveness
of spatial data organization.


title: Energy integrals over local fields and global height bounds

abstract:
  We solve an energy minimization problem for local fields. As an application
of these results, we improve on lower bounds set by Bombieri and Zannier for
the limit infimum of the Weil height in fields of totally p-adic numbers and
generalizations thereof. In the case of fields with mixed archimedean and
non-archimedean splitting conditions, we are able to combine our bounds with
similar bounds at the archimedean places for totally real fields.


title:
Propeller-Effect Interpretation of MAXI/GSC Light Curves of 4U 1608-52
  and AqlX-1 and application to XTE J1701-462

abstract:
  We present the luminosity dwell-time distributions during the hard states of
low-mass X-ray binaries containing a neutron star, 4U 1608-52 and AqlX-1,
observed with MAXI/GSC. The luminosity distributions show a steep cut-off in
the low-luminosity side at $\sim1.0 \times 10^{36}$ erg s$^{-1}$ in both the
two sources. The cut-off implies a rapid luminosity decrease in their outburst
decay phases, and the feature can be interpreted as due the propeller effect.
We estimated the surface magnetic field of the neutron star to be (0.5--1.6)
$\times 10^8$ G in 4U 1608-52 and (0.6--1.9) $\times 10^8$ G in AqlX-1 from the
cut-off luminosity. We applied the same propeller mechanism to the similar
rapid luminosity decrease observed in the transient Z-source, XTE J1701-462,
with RXTE/ASM. Assuming that spin period of the neutron star is in the order of
milliseconds, the observed cut-off luminosity deduces surface magnetic field in
the order of $10^9$ G.


title: Cellular Automata in Cryptographic Random Generators

abstract:
  Cryptographic schemes using one-dimensional, three-neighbor cellular automata
as a primitive have been put forth since at least 1985. Early results showed
good statistical pseudorandomness, and the simplicity of their construction
made them a natural candidate for use in cryptographic applications. Since
those early days of cellular automata, research in the field of cryptography
has developed a set of tools which allow designers to prove a particular scheme
to be as hard as solving an instance of a well- studied problem, suggesting a
level of security for the scheme. However, little or no literature is available
on whether these cellular automata can be proved secure under even generous
assumptions. In fact, much of the literature falls short of providing complete,
testable schemes to allow such an analysis.
  In this thesis, we first examine the suitability of cellular automata as a
primitive for building cryptographic primitives. In this effort, we focus on
pseudorandom bit generation and noninvertibility, the behavioral heart of
cryptography. In particular, we focus on cyclic linear and non-linear au-
tomata in some of the common configurations to be found in the literature. We
examine known attacks against these constructions and, in some cases, improve
the results.
  Finding little evidence of provable security, we then examine whether the
desirable properties of cellular automata (i.e. highly parallel, simple
construction) can be maintained as the automata are enhanced to provide a
foundation for such proofs. This investigation leads us to a new construction
of a finite state cellular automaton (FSCA) which is NP-Hard to invert.
Finally, we introduce the Chasm pseudorandom generator family built on this
construction and provide some initial experimental results using the NIST test
suite.


title: High temperature superconductivity: Cooper pairs in trap

abstract:
  The tremendous efforts to unveil high temperature superconductivity (HTSC)
have been devoted to the search of the mechanism underlying Cooper pairs which,
however, remains a mysterious subject of vigorous debate, let alone many other
mysteries like the pseudogap state, the peculiar Homes law, the unnegligible
electron-phonon interaction, the stripe, the universal nodal Fermi velocity,
etc. Most of subsequent works either bring in more controversies or swell the
list of mysteries. Here I tentatively propose a whole new perspective on the
basis of low-dimensional Bose-Einstein Condensation (LDBEC), which possibly
makes lots of those mysteries correlated and understood in single picture.


title: Encoding Higher Level Extensions of Petri Nets in Answer Set Programming

abstract:
  Answering realistic questions about biological systems and pathways similar
to the ones used by text books to test understanding of students about
biological systems is one of our long term research goals. Often these
questions require simulation based reasoning. To answer such questions, we need
formalisms to build pathway models, add extensions, simulate, and reason with
them. We chose Petri Nets and Answer Set Programming (ASP) as suitable
formalisms, since Petri Net models are similar to biological pathway diagrams;
and ASP provides easy extension and strong reasoning abilities. We found that
certain aspects of biological pathways, such as locations and substance types,
cannot be represented succinctly using regular Petri Nets. As a result, we need
higher level constructs like colored tokens. In this paper, we show how Petri
Nets with colored tokens can be encoded in ASP in an intuitive manner, how
additional Petri Net extensions can be added by making small code changes, and
how this work furthers our long term research goals. Our approach can be
adapted to other domains with similar modeling needs.


title: On f-biharmonic maps and f-biharmonic submanifolds

abstract:
  f-Biharmonic maps are the extrema of the f-bienergy functional. f-biharmonic
submanifolds are submanifolds whose defining isometric immersions are
f-biharmonic maps. In this paper, we prove that an f-biharmonic map from a
compact Riemannian manifold into a non-positively curved manifold with constant
f-bienergy density is a harmonic map; any f-biharmonic function on a compact
manifold is constant, and that the inversions about $S^m$ for $m\ge 3$ are
proper f-biharmonic conformal diffeomorphisms. We derive f-biharmonic
submanifolds equations and prove that a surface in a manifold $(N^n, h)$ is an
f-biharmonic surface if and only it can be biharmonically conformally immersed
into $(N^n,h)$. We also give a complete classification of f-biharmonic curves
in 3-dimensional Euclidean space. Many examples of proper f-biharmonic maps and
f-biharmonic surfaces and curves are given.


title: Irreducible triangulations of the M\"obius band

abstract:
  A complete list of irreducible triangulations is identified on the M\"obius
band.


title:
Proceedings of the 2nd Workshop on Robots in Clutter: Preparing robots
  for the real world (Berlin, 2013)

abstract:
  This volume represents the proceedings of the 2nd Workshop on Robots in
Clutter: Preparing robots for the real world, held June 27, 2013, at the
Robotics: Science and Systems conference in Berlin, Germany.


title:
X-ray and Radio Follow-up Observations of High-Redshift Blazar
  Candidates in the Fermi-LAT Unassociated Source Population

abstract:
  We report on the results of X-ray and radio follow-up observations of two GeV
gamma-ray sources 2FGL J0923.5+1508 and 2FGL J1502.1+5548, selected as
candidates for high-redshift blazars from unassociated sources in the {\it
Fermi} Large Area Telescope Second Source Catalog. We utilize the Suzaku
satellite and the VLBI Exploration of Radio Astrometry (VERA) telescopes for
X-ray and radio observations, respectively. For 2FGL J0923.5+1508, a possible
radio counterpart NVSS J092357+150518 is found at 1.4 GHz from an existing
catalog, but we do not detect any X-ray emission from it and derive a flux
upper limit $F_{\rm 2-8 keV} <$ 1.37 $\times$ 10$^{-14}$ erg cm$^{-2}$
s$^{-1}$. Radio observations at 6.7 GHz also result in an upper limit of
$S_{\rm 6.7 GHz}$ $<$ 19 mJy, implying a steep radio spectrum that is not
expected for a blazar. On the other hand, we detect X-rays from NVSS
J150229+555204, the potential 1.4 GHz radio counterpart of 2FGL J1502.1+5548.
The X-ray spectrum can be fitted with an absorbed power-law model with a photon
index $\gamma$=1.8$^{+0.3}_{-0.2}$ and the unabsorbed flux is $F_{\rm 2-8
keV}$=4.3$^{+1.1}_{-1.0}$ $\times$ 10$^{-14}$ erg cm$^{-2}$ s$^{-1}$. Moreover,
we detect unresolved radio emission at 6.7 GHz with flux $S_{\rm 6.7 GHz}$=30.1
mJy, indicating a compact, flat-spectrum radio source. If NVSS J150229+555204
is indeed associated with 2FGL J1502.1+5548, we find that its multiwavelength
spectrum is consistent with a blazar at redshift $z \sim 3-4$.


title:
Bound state of particle in delta-potential in tomographic representation
  of quantum mechanics

abstract:
  The problem of quantum particle moving in Dirac delta potential with instant
changing well depth is studied by using formalism of tomographic representation
of quantum mechanics.The bound state tomogram is given in terms of error
function.The ionisation probability due to instant change of the potential
parameter is calculated in terms of integral containing the state tomograms.The
probability of ionisation is also expressed in terms of the Wigner function.


title: Thermodynamics of long-run economic innovation and growth

abstract:
  This article derives prognostic expressions for the evolution of globally
aggregated economic wealth, productivity, inflation, technological change,
innovation and growth. The approach is to treat civilization as an open,
non-equilibrium thermodynamic system that dissipates energy and diffuses matter
in order to sustain existing circulations and to further its material growth.
Appealing to a prior result that established a fixed relationship between a
very general representation of global economic wealth and rates of global
primary energy consumption, physically derived expressions for economic
quantities follow. The analysis suggests that wealth can be expressed in terms
of the length density of civilization's networks and the availability of energy
resources. Rates of return on wealth are accelerated by energy reserve
discovery, improvements to human and infrastructure longevity, and a more
common culture, or a lowering of the amount of energy required to diffuse raw
materials into civilization's bulk. According to a logistic equation, rates of
return are slowed by past growth, and if rates of return approach zero, such
"slowing down" makes civilization fragile with respect to externally imposed
network decay. If past technological change has been especially rapid, then
civilization is particularly vulnerable to newly unfavorable conditions that
might force a switch into a mode of accelerating collapse.


title: Calabi-Yau quotients with terminal singularities

abstract:
  In this paper we are interested in quotients of Calabi-Yau threefolds with
isolated singularities. In particular, we analyze the case when $X/G$ has
terminal singularities. We prove that, if $G$ is cyclic of prime order and
$X/G$ has terminal singularities, then $G$ has order $2,3$ or $5$.


title: Neutrino mass textures with one vanishing minor and two equal cofactors

abstract:
  In this paper, we carry out a numerical and systematic analysis of the
neutrino mass textures, which contain one vanishing minor and an equality
between two cofactors. Among 60 logically possible textures, only eight of them
are excluded for both normal and inverted hierarchy by the current experimental
data at 3\sigma level. We also demonstrate that the future long-baseline
neutrino oscillation experiments, especially for the measurement of \theta 23
mixing angle, will play the important role in the model selection. The
phenomenological implications from neutrinoless double beta decay and the
cosmology observation are also examined. A discussion on the flavor symmetry
realization of the textures is also given.


title: The Hamiltonians generating one-dimensional discrete-time quantum walks

abstract:
  An explicit formula of the Hamiltonians generating one-dimensional
discrete-time quantum walks is given. The formula is deduced by using the
algebraic structure introduced previously. The square of the Hamiltonian turns
out to be an operator without, essentially, the `coin register', and hence it
can be compared with the one-dimensional continuous-time quantum walk. It is
shown that, under a limit with respect to a parameter, which expresses the
magnitude of the diagonal components of the unitary matrix defining the
discrete-time quantum walks, the one-dimensional continuous-time quantum walk
is obtained from operators defined through the Hamiltonians of the
one-dimensional discrete-time quantum walks. Thus, this result can be regarded,
in one-dimension, as a partial answer to a problem proposed by Ambainis.


title: Outlying Property Detection with Numerical Attributes

abstract:
  The outlying property detection problem is the problem of discovering the
properties distinguishing a given object, known in advance to be an outlier in
a database, from the other database objects. In this paper, we analyze the
problem within a context where numerical attributes are taken into account,
which represents a relevant case left open in the literature. We introduce a
measure to quantify the degree the outlierness of an object, which is
associated with the relative likelihood of the value, compared to the to the
relative likelihood of other objects in the database. As a major contribution,
we present an efficient algorithm to compute the outlierness relative to
significant subsets of the data. The latter subsets are characterized in a
"rule-based" fashion, and hence the basis for the underlying explanation of the
outlierness.


title: The Lowest Metallicity Stars in the LMC: Clues from MaGICC Simulations

abstract:
  Using a cosmological hydrodynamical simulation of a galaxy of similar mass to
the Large Magellanic Cloud (LMC), we examine the predicted characteristics of
its lowest metallicity populations. In particular, we emphasise the spatial
distributions of first (Pop III) and second (polluted by only immediate Pop III
ancestors) generation stars. We find that primordial composition stars form not
only in the central galaxy's progenitor, but also in locally collapsed
sub-halos during the early phases of galaxy formation. The lowest metallicity
stars in these sub-halos end up in a relatively extended distribution around
the host, with these accreted stars possessing present-day galactocentric
distances as great as ~40kpc. By contrast, the earliest stars formed within the
central galaxy remain in the inner region, where the vast majority of star
formation occurs, for the entirety of the simulation. Consequently, the
fraction of stars that are from the earliest generation increases strongly with
radius.


title: iCub World: Friendly Robots Help Building Good Vision Data-Sets

abstract:
  In this paper we present and start analyzing the iCub World data-set, an
object recognition data-set, we acquired using a Human-Robot Interaction (HRI)
scheme and the iCub humanoid robot platform. Our set up allows for rapid
acquisition and annotation of data with corresponding ground truth. While more
constrained in its scopes -- the iCub world is essentially a robotics research
lab -- we demonstrate how the proposed data-set poses challenges to current
recognition systems. The iCubWorld data-set is publicly available. The data-set
can be downloaded from: http://www.iit.it/en/projects/data-sets.html.


title:
Supersymmetric double-well matrix model as two-dimensional type IIA
  superstring on RR background

abstract:
  In the previous paper, the authors pointed out correspondence of a
supersymmetric double-well matrix model with two-dimensional type IIA
superstring theory on a nontrivial Ramond-Ramond background from the viewpoint
of symmetries and spectrum. In this paper we further investigate the
correspondence from dynamical aspects by comparing scattering amplitudes in the
matrix model and those in the type IIA theory. In the latter, cocycle factors
are introduced to vertex operators in order to reproduce correct transformation
laws and target-space statistics. By a perturbative treatment of the
Ramond-Ramond background as insertions of the corresponding vertex operators,
various IIA amplitudes are explicitly computed including quantitatively precise
numerical factors. We show that several kinds of amplitudes in both sides
indeed have exactly the same dependence on parameters of the theory. Moreover,
we have a number of relations among coefficients which connect quantities in
the type IIA theory and those in the matrix model. Consistency of the relations
convinces us of the validity of the correspondence.


title:
Monte Carlo simulations of dynamic phase transitions in ultrathin
  Blume-Capel films

abstract:
  Dynamic phase transition phenomena in ultrathin films described by
Blume-Capel model have been investigated using Monte Carlo simulations.
Hysteresis loops, micromagnetic structures, and hysteresis loop area curves, as
well as dynamic correlation between the magnetization and the external field
have been studied as functions of the field, as well as the film parameters.
The variation of critical coupling of the modified film surface at which the
transition temperature becomes independent of film thickness have been
clarified for varying system parameters. Frequency dispersion of hysteresis
loop area have been found to obey a power law for low and moderate frequencies
for both ordinary and enhanced surfaces.


title: Surface plasmons in coaxial metamaterial cables

abstract:
  Thanks to Victor Veselago for his hypothesis of negative index of refraction,
metamaterials -- engineered composites -- can be designed to have properties
difficult or impossible to find in nature: they can have both electrical
permitivity ($\epsilon$) and magnetic permeability ($\mu$) simultaneously
negative. The metamaterials -- henceforth negative-index materials (NIMs) --
owe their properties to subwavelength structure rather than to their chemical
composition. The tailored electromagnetic response of the NIMs has had a
dramatic impact on the classical optics: they are becoming known to have
changed many basic notions related with the electromagnetism. The present
article is focused on gathering and reviewing the fundamental characteristics
of plasmon propagation in the coaxial cables fabricated of the right-handed
medium (RHM) [with $\epsilon>0$, $\mu>0$] and the left-handed medium (LHM)
[with $\epsilon<0$, $\mu<0$] in alternate shells starting from the innermost
cable. Such structures as conceived here may pave the way to some interesting
effects in relation to, e.g., the optical science exploiting the cylindrical
symmetry of the coaxial waveguides that make it possible to perform all major
functions of an optical fiber communication system in which the light is born,
manipulated, and transmitted without ever leaving the fiber environment, with
precise control over the polarization rotation and pulse broadening. The review
also covers briefly the nomenclature, classification, potential applications,
and the limitations (related, e.g., to the inherent losses) of the NIMs and
their impact on the classical electrodynamics, in general, and in designing the
cloaking devices, in particular. Recent surge in efforts on invisibility and
the cloaking devices seems to have spoiled the researchers worldwide:


title:
Impact of Triaxiality on the Emission and Absorption of Neutrons and
  Gamma Rays in Heavy Nuclei

abstract:
  For many spin-0 target nuclei neutron capture measurements yield information
on level densities at the neutron separation energy. Also the average photon
width has been determined from capture data as well as Maxwellian average cross
sections for the energy range of unresolved resonances. Thus it is challenging
to use this data set for a test of phenomenological prescriptions for the
prediction of radiative processes. An important ingredient for respective
calculations is the photon strength function for which a parameterization was
proposed using a fit to giant dipole resonance shapes on the basis of
theoretically determined ground state deformations including triaxiality.
Deviations from spherical and axial symmetry also influence level densities and
it is suggested to use a combined parameterization for both, level density and
photon strength. The formulae presented give a good description of the data for
low spin capture into 124 nuclei with 72<A<244 and only very few global
parameters have to be adjusted when the predetermined information on ground
state shapes of the nuclei involved is accounted for.


title: The CP(N-1) model on a Disc and Decay of a Non-Abelian String

abstract:
  We consider the role of quantum effects in the non-perturbative decay of
non-abelian string with orientational moduli in non-supersymmetric D=4 gauge
theory. To this aim the effective action in the $CP(N-1)$ model on a disc at
large N has been calculated. It exhibits phase transition at some radius, the
"wrong sign" Luscher term and large boundary boojum-like negative contribution.
The effect of $\theta$ - term and the possibility of the spontaneous creation
of the non-abelian string are briefly discussed.


title: Faster deterministic Feedback Vertex Set

abstract:
  We present two new deterministic algorithms for the Feedback Vertex Set
problem parameterized by the solution size. We begin with a simple algorithm,
which runs in O*((2 + \phi)^k) time, where \phi < 1.619 is the golden ratio. It
already surpasses the previously fastest O*((1+2sqrt(2))^k)-time deterministic
algorithm due to Cao et al. [SWAT 2010]. In our developments we follow the
approach of Cao et al., however, thanks to a new reduction rule, we obtain not
only better dependency on the parameter in the running time, but also a
solution with simple analysis and only a single branching rule. Then, we
present a modification of the algorithm which, using a more involved set of
branching rules, achieves O*(3.592^k) running time.


title: Quantum pinch effect

abstract:
  We investigate a two-component, cylindrical, quasi-one-dimensional quantum
plasma subjected to a {\em radial} confining harmonic potential and an applied
magnetic field in the symmetric gauge. It is demonstrated that such a system as
can be realized in semiconducting quantum wires offers an excellent medium for
observing the quantum pinch effect at low temperatures. An exact analytical
solution of the problem allows us to make significant observations:
surprisingly, in contrast to the classical pinch effect, the particle density
as well as the current density display a {\em determinable} maximum before
attaining a minimum at the surface of the quantum wire. The effect will persist
as long as the equilibrium pair density is sustained. Therefore, the
technological promise that emerges is the route to the precise electronic
devices that will control the particle beams at the nanoscale.


title:
Multiple values and uniqueness problem of meromorphic mappings sharing
  hypersurfaces

abstract:
  The purpose of this article is to deal with the multiple values and
uniqueness problem of meromorphic mappings from $\mathbb{C}^{m}$ into the
complex projective space $\mathbb{P}^{n}(\mathbb{C})$ sharing fixed and moving
hypersurfaces. We obtain several uniqueness theorems which improve and extend
some known results.


title:
Coherence properties of focused X-ray beams at high brilliance
  synchrotron sources

abstract:
  An analytical approach describing properties of focused partially coherent
X-ray beams is presented. The method is based on the results of statistical
optics and gives both the beam size and transverse coherence length at any
distance behind an optical element. In particular, here we consider Gaussian
Schell-model beams and thin optical elements. Limiting cases of incoherent and
fully coherent illumination of the focusing element are discussed. The effect
of the beam defining aperture, typically used in combination with focusing
elements at synchrotron sources to improve transverse coherence, is also
analyzed in detail. As an example the coherence properties in the focal region
of compound refractive lenses at the PETRA III synchrotron source are analyzed.


title:
Theory of confined plasmonic waves in coaxial cylindrical cables
  fabricated of metamaterials

abstract:
  We report on the theoretical investigation of the plasmonic wave propagation
in the coaxial cylindrical cables fabricated of both right-handed medium (RHM)
[with $\epsilon >0$, $\mu >0$] and left-handed medium (LHM) [with
$\epsilon(\omega) <0$, $\mu(\omega) <0$], using a Green-function (or response
function) theory in the absence of an applied magnetic field. The
Green-function theory generalized to be applicable to such quasi-one
dimensional systems enables us to derive explicit expressions for the
corresponding response functions (associated with the EM fields), which can in
turn be used to derive various physical properties of the system. The confined
plasmonic wave excitations in such multi-interface structures are characterized
by the electromagnetic fields that are localized at and decay exponentially
away from the interfaces. A rigorous analytical diagnosis of the general
results in diverse situations leads us to reproduce exactly the previously
well-known results in other geometries, obtained within the different
theoretical frameworks. As an application, we present several illustrative
examples on the dispersion characteristics of the confined (and extended)
plasmonic waves in single- and double-interface structures made up of
dispersive metamaterials interlaced with conventional dielectrics. These
dispersive modes are also substantiated through the computation of local as
well as total density of states. It is observed that the dispersive components
enable the system to support the simultaneous existence of s- and
p-polarization modes in the system. Such effects as this one are solely
attributed to the negative-index metamaterials and are otherwise impossible...


title:
On the Boundary Behavior of Positive Solutions of Elliptic Differential
  Equations

abstract:
  Let $u$ be a positive harmonic function in the unit ball $B_1 \subset
\mathbb{R}^n$ and let $\mu$ be the boundary measure of $u$. Consider a point
$x\in \partial B_1$ and let $n(x)$ denote the unit normal vector at $x$. Let
$\alpha$ be a number in $(-1,n-1]$ and $A \in [0,+\infty) $. We prove that
$u(x+n(x)t)t^{\alpha} \to A$ as $t \to +0$ if and only if
$\frac{\mu({B_r(x)})}{r^{n-1}} r^{\alpha} \to C_\alpha A$ as $r\to+0$, where
${C_\alpha=
\frac{\pi^{n/2}}{\Gamma(\frac{n-\alpha+1}{2})\Gamma(\frac{\alpha+1}{2})}}$. For
$\alpha=0$ it follows from the theorems by Rudin and Loomis which claim that a
positive harmonic function has a limit along the normal iff the boundary
measure has the derivative at the corresponding point of the boundary. For
$\alpha=n-1$ it concerns about the point mass of $\mu$ at $x$ and it follows
from the Beurling minimal principle. For the general case of $\alpha \in
(-1,n-1)$ we prove it with the help of the Wiener Tauberian theorem in a
similar way to Rudin's approach. Unfortunately this approach works for a ball
or a half-space only but not for a general kind of domain. In dimension $2$ one
can use conformal mappings and generalise the statement above to sufficiently
smooth domains, in dimension $n\geq 3$ we showed that this generalisation is
possible for $\alpha\in [0,n-1]$ due to harmonic measure estimates. The last
method leads to an extension of the theorems by Loomis, Ramey and Ullrich on
non-tangential limits of harmonic functions to positive solutions of elliptic
differential equations with Holder continuous coefficients.


title:
An Intensely Star-Forming Galaxy at z~7 with Low Dust and Metal Content
  Revealed by Deep ALMA and HST Observations

abstract:
  We report deep ALMA observations complemented with associated HST imaging for
a luminous (m_uv=25) galaxy, `Himiko', at a redshift z=6.595. The galaxy is
remarkable for its high star formation rate, 100 Mo/yr, securely estimated from
our deep HST and Spitzer photometry, and the absence of any evidence for strong
AGN activity or gravitational lensing magnification. Our ALMA observations
probe an order of magnitude deeper than previous IRAM observations, yet fail to
detect a 1.2mm dust continuum, indicating a flux <52uJy comparable with or
weaker than that of local dwarf irregulars with much lower star formation
rates. We likewise provide a strong upper limit for the flux of [CII] 158um,
L([CII]) < 5.4x10^7 Lo, a diagnostic of the hot interstellar gas often
described as a valuable probe for early galaxies. In fact, our observations
indicate Himiko lies off the local L([CII]) - star formation rate scaling
relation by a factor of more than 30. Both aspects of our ALMA observations
suggest Himiko is an unique object with a very low dust content and perhaps
nearly primordial interstellar gas. Our HST images provide unique insight into
the morphology of this remarkable source, highlighting an extremely blue core
of activity and two less extreme associated clumps. Himiko is undergoing a
triple major merger event whose extensive ionized nebula of Lyman alpha
emitting gas, discovered in our earlier work with Subaru, is powered by star
formation and the dense circum-galactic gas. We are likely witnessing an early
massive galaxy during a key period of its mass assembly close to the end of the
reionization era.


title:
Low-frequency surface plasmon excitations in multicoaxial negative-index
  metamaterial cables

abstract:
  By using an elegant response function theory, which does not require matching
of the messy boundary conditions, we investigate the surface plasmon
excitations in the multicoaxial cylindrical cables made up of negative-index
metamaterials. The multicoaxial cables with {\em dispersive} metamaterial
components exhibit rather richer (and complex) plasmon spectrum with each
interface supporting two modes: one TM and the other TE for (the integer order
of the Bessel function) $m \ne 0$. The cables with {\em nondispersive}
metamaterial components bear a different tale: they do not support
simultaneously both TM and TE modes over the whole range of propagation vector.
The computed local and total density of states enable us to substantiate
spatial positions of the modes in the spectrum. Such quasi-one dimensional
systems as studied here should prove to be the milestones of the emerging
optoelectronics and telecommunications systems.


title:
Early stopping and non-parametric regression: An optimal data-dependent
  stopping rule

abstract:
  The strategy of early stopping is a regularization technique based on
choosing a stopping time for an iterative algorithm. Focusing on non-parametric
regression in a reproducing kernel Hilbert space, we analyze the early stopping
strategy for a form of gradient-descent applied to the least-squares loss
function. We propose a data-dependent stopping rule that does not involve
hold-out or cross-validation data, and we prove upper bounds on the squared
error of the resulting function estimate, measured in either the $L^2(P)$ and
$L^2(P_n)$ norm. These upper bounds lead to minimax-optimal rates for various
kernel classes, including Sobolev smoothness classes and other forms of
reproducing kernel Hilbert spaces. We show through simulation that our stopping
rule compares favorably to two other stopping rules, one based on hold-out data
and the other based on Stein's unbiased risk estimate. We also establish a
tight connection between our early stopping strategy and the solution path of a
kernel ridge regression estimator.


title: Entropy of Quantum Fields in de Sitter Space-time

abstract:
  The quantum states or Hilbert spaces for the quantum field theory in de
Sitter space-time are studied on ambient space formalism. In this formalism,
the quantum states are only depended $(1)$ on the topological character of the
de Sitter space-time, {\it i.e.} $\R \times S^3$, and $(2)$ on the homogeneous
spaces which are used for construction of the unitary irreducible
representation of de Sitter group. A compact homogeneous space is chosen in
this paper. The unique feature of this homogeneous space is that its total
number of quantum states, ${\cal N}$, is finite although the Hilbert space has
infinite dimensions. It is shown that ${\cal N}$ is a continuous function of
the Hubble constant $H$ and the eigenvalue of the Casimir operators of de
Sitter group. The entropy of the quantum fields on this Hilbert space have been
calculated which is finite and invariant for all inertial observers on the de
Sitter hyperboloid.


title: Multiplex PageRank

abstract:
  Many complex systems can be described as multiplex networks in which the same
nodes can interact with one another in different layers, thus forming a set of
interacting and co-evolving networks. Examples of such multiplex systems are
social networks where people are involved in different types of relationships
and interact through various forms of communication media. The ranking of nodes
in multiplex networks is one of the most pressing and challenging tasks that
research on complex networks is currently facing. When pairs of nodes can be
connected through multiple links and in multiple layers, the ranking of nodes
should necessarily reflect the importance of nodes in one layer as well as
their importance in other interdependent layers. In this paper, we draw on the
idea of biased random walks to define the Multiplex PageRank centrality measure
in which the effects of the interplay between networks on the centrality of
nodes are directly taken into account. In particular, depending on the
intensity of the interaction between layers, we define the Additive,
Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show
how each version reflects the extent to which the importance of a node in one
layer affects the importance the node can gain in another layer. We discuss
these measures and apply them to an online multiplex social network. Findings
indicate that taking the multiplex nature of the network into account helps
uncover the emergence of rankings of nodes that differ from the rankings
obtained from one single layer. Results provide support in favor of the
salience of multiplex centrality measures, like Multiplex PageRank, for
assessing the prominence of nodes embedded in multiple interacting networks,
and for shedding a new light on structural properties that would otherwise
remain undetected if each of the interacting networks were analyzed in
isolation.


title: A geometric one-sided inequality for zero-viscosity limits

abstract:
  The Oleinik inequality for conservation laws and Aronson-Benilan type
inequalities for porous medium or p-Laplacian equations are one-sided
inequalities that provide the fundamental features of the solution such as the
uniqueness and sharp regularity. In this paper such one-sided inequalities are
unified and generalized for a wide class of first and second order equations in
the form of $$ u_t=\sigma(t,u,u_x,u_{xx}),\quad u(x,0)=u^0(x)\ge0,\quad
t>0,\,x\in\bfR, $$ where the non-strict parabolicity ${\partial\over\partial q}
\sigma(t,z,p,q)\ge0$ is assumed. The generalization or unification of one-sided
inequalities is given in a geometric statement that the zero level set $$
A(t;m,x_0):=\{x:\rhom(x-x_0,t)-u(x,t)>0\} $$ is connected for all $t,m>0$ and
$x_0\in\bfR$, where $\rhom$ is the fundamental solution with mass $m>0$. This
geometric statement is shown to be equivalent to the previously mentioned
one-sided inequalities and used to obtain uniqueness and TV boundedness of
conservation laws without convexity assumption. Multi-dimensional extension for
the heat equation is also given.


title:
Evolution of the phase-space density and the Jeans scale for dark matter
  derived from the Vlasov-Einstein equation

abstract:
  We discuss solutions of Vlasov-Einstein equation for collisionless dark
matter particles in the context of a flat Friedmann universe. We show that,
after decoupling from the primordial plasma, the dark matter phase-space
density indicator Q remains constant during the expansion of the universe,
prior to structure formation. This well known result is valid for
non-relativistic particles and is not "observer dependent" as in solutions
derived from the Vlasov-Poisson system. In the linear regime, the inclusion of
velocity dispersion effects permits to define a physical Jeans length for
collisionless matter as function of the primordial phase-space density
indicator: \lambda_J = (5\pi/G)^(1/2)Q^(-1/3)\rho_dm^(-1/6). The comoving Jeans
wavenumber at matter-radiation equality is smaller by a factor of 2-3 than the
comoving wavenumber due to free-streaming, contributing to the cut-off of the
density fluctuation power spectrum at the lowest scales. We discuss the
physical differences between these two scales. For dark matter particles of
mass equal to 200 GeV, the derived Jeans mass is 4.3 x 10^(-6) solar masses.


title: The spin Hall effect in a quantum gas

abstract:
  Electronic properties like current flow are generally independent of the
electron's spin angular momentum, an internal degree of freedom present in
quantum particles. The spin Hall effects (SHEs), first proposed 40 years ago,
are an unusual class of phenomena where flowing particles experience
orthogonally directed spin-dependent Lorentz-like forces, analogous to the
conventional Lorentz force for the Hall effect, but opposite in sign for two
spin states. Such spin Hall effects have been observed for electrons flowing in
spin-orbit coupled materials such as GaAs or InGaAs and for laser light
traversing dielectric junctions. Here we observe the spin Hall effect in a
quantum-degenerate Bose gas, and use the resulting spin-dependent Lorentz
forces to realize a cold-atom spin transistor. By engineering a spatially
inhomogeneous spin-orbit coupling field for our quantum gas, we explicitly
introduce and measure the requisite spin-dependent Lorentz forces, in excellent
agreement with our calculations. This atomtronic circuit element behaves as a
new type of velocity-insensitive adiabatic spin-selector, with potential
application in devices such as magnetic or inertial sensors. In addition, such
techniques --- for both creating and measuring the SHE --- are clear
prerequisites for engineering topological insulators and detecting their
associated quantized spin Hall effects in quantum gases. As implemented, our
system realized a laser-actuated analog to the Datta-Das spin transistor.


title: The Dirac Conjecture and the Non-uniqueness of Lagrangian

abstract:
  By adding the total time derivatives of all the constraints to the Lagrangian
step by step, we achieve the further work of the Dirac conjecture left by
Dirac. Hitherto, the Dirac conjecture is proved completely. It is worth
noticing that the addition of the total time derivatives to the Lagrangian can
turn up some constraints hiding in the original Lagrangian. For a constrained
system, the extended Hamiltonian $H_E$ considers more constraints, and shows
symmetries more obviously than the total Hamiltonian $H_T$. In the Lagrangian
formalism, we reconsider the Cawley counterexample, and offer an example in
which in accordance with its original Lagrangian its extended Hamiltonian is
better than its total Hamiltonian.


title:
Horizontal or vertical magnetic fields on the quiet Sun: Angular
  distributions and their height variations

abstract:
  Different analyses of identical Hinode SOT/SP data of quiet-sun magnetic
fields have in the past led to contradictory answers to the question of whether
the angular distribution of field vectors is preferentially horizontal or
vertical. These answers have been obtained by combining the measured circular
and linear polarizations in different ways to derive the field inclinations. A
problem with these combinations is that the circular and linear polarizations
scale with field strength in profoundly different ways. Here, we avoid these
problems by using an entirely different approach that is based exclusively on
the fundamental symmetry properties of the transverse Zeeman effect for
observations away from the disk center without any dependence on the circular
polarization. Systematic errors are suppressed by the application of a doubly
differential technique with the 5247-5250 \AA\ line pair for observations with
the ZIMPOL-2 imaging polarimeter on the French THEMIS telescope on Tenerife.
This allows us to determine in a model- and resolution-independent way how the
angular distribution of the intranetwork magnetic fields changes from being
preferentially vertical in the lower and middle photosphere to become
preferentially horizontal in the upper photosphere.


title:
Wide temperature span of entropy change in first-order metamagnetic
  MnCo1-xFexSi

abstract:
  The crystal structure and magnetic properties of MnCoxFe1-xSi (x=0-0.5)
compounds were investigated. With increasing Fe content, the unit cell changes
anisotropically and the magnetic property evolves gradually: Curie temperature
decreases continuously, the first-order metamagnetic transition from a
low-temperature helical antiferromagnetic state to a high-temperature
ferromagnetic state disappears gradually and then a spin-glass-like state and
another antiferromagnetic state emerge in the low temperature region. The Curie
transition leads to a moderate conventional entropy change. The metamagnetic
transition not only yields a larger negative magnetocaloric effect at lower
applied fields than in MnCoSi but also produces a very large temperature span
(103 K for H=5 T) of delta S(T), which results in a large refrigerant capacity.
These phenomena were explained in terms of crystal structure change and
magnetoelastic coupling mechanism. The low-cost MnCo1-xFexSi compounds are
promising candidates for near room temperature magnetic refrigeration
applications because of the large isothermal entropy change and the wide
working temperature span.


title: Gluon production in the Lipatov effective action formalism

abstract:
  Gluon production on two scattering centers is studied in the formalism of
reggeized gluons. Different contributions to the inclusive cross-section are
derived with the help of the Lipatov effective action. The AGK relations
between these contributions are established. The found inclusive cross-section
is compared to the one in the dipole picture and demonstrated to be the same.


title: Recurrent Convolutional Neural Networks for Discourse Compositionality

abstract:
  The compositionality of meaning extends beyond the single sentence. Just as
words combine to form the meaning of sentences, so do sentences combine to form
the meaning of paragraphs, dialogues and general discourse. We introduce both a
sentence model and a discourse model corresponding to the two levels of
compositionality. The sentence model adopts convolution as the central
operation for composing semantic vectors and is based on a novel hierarchical
convolutional neural network. The discourse model extends the sentence model
and is based on a recurrent neural network that is conditioned in a novel way
both on the current sentence and on the current speaker. The discourse model is
able to capture both the sequentiality of sentences and the interaction between
different speakers. Without feature engineering or pretraining and with simple
greedy decoding, the discourse model coupled to the sentence model obtains
state of the art performance on a dialogue act classification experiment.


title: Exponential Mixing for Retarded Stochastic Differential Equations

abstract:
  In this paper, we discuss exponential mixing property for Markovian
semigroups generated by segment processes associated with several class of
retarded Stochastic Differential Equations (SDEs) which cover SDEs with
constant/variable/distributed time-lags. In particular, we investigate the
exponential mixing property for (a) non-autonomous retarded SDEs by the
Arzel\`{a}--Ascoli tightness characterization of the space $\C$ equipped with
the uniform topology (b) neutral SDEs with continuous sample paths by a
generalized Razumikhin-type argument and a stability-in-distribution approach
and (c) jump-diffusion retarded SDEs by the Kurtz criterion of tightness for
the space $\D$ endowed with the Skorohod topology.


title:
Distinguishing the Color Octet Axial-Vector-like Particle for Top Quark
  Asymmetry via Color Flow Method at the LHC

abstract:
  The excess in top quark forward-backward asymmetry has been a hot topic in
recent years. Although there are many proposals to explain it, most of them can
not fit the differential distributions well. The color octet axial-vector like
particle, with mass near the top quark pair threshold, is still a good
description of the differential distributions. We study how to distinguish the
color singlet and octet mediating particles in top quark pair production by
adopting the color flow method. For the first time, we show that such a
proposal for the froward-backward asymmetry can be cross-checked indirectly at
the LHC.


title:
Condensation in stochastic particle systems with stationary product
  measures

abstract:
  We study stochastic particle systems with stationary product measures that
exhibit a condensation transition due to particle interactions or spatial
inhomogeneities. We review previous work on the stationary behaviour and put it
in the context of the equivalence of ensembles, providing a general
characterization of the condensation transition for homogeneous and
inhomogeneous systems in the thermodynamic limit. This leads to strengthened
results on weak convergence for subcritical systems, and establishes the
equivalence of ensembles for spatially inhomogeneous systems under very general
conditions, extending previous results which were focused on attractive and
finite systems. We use relative entropy techniques which provide simple proofs,
making use of general versions of local limit theorems for independent random
variables.

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


title:
Propagation of singularities for weak KAM solutions and barrier
  functions

abstract:
  This paper studies the structure of the singular set (points of
nondifferentiability) of viscosity solutions to Hamilton-Jacobi equations
associated with general mechanical systems on the n-torus. First, using the
level set method, we characterize the propagation of singularities along
generalized characteristics. Then, we obtain a local propagation result for
singularities of weak KAM solutions in the supercritical case. Finally, we
apply such a result to study the propagation of singularities for barrier
functions.


title:
Effect of electrode geometry on photovoltaic performance of polymer
  solar cells

abstract:
  This paper investigates the impact of electrode geometry on the performance
of polymer solar cells (PSCs). Four types of negative electrodes with equal
area (0.09 cm2) but different shape (round, oval, square, and triangular) are
evaluated with respect to short-circuit current density, open-circuit voltage,
fill factor, and power conversion efficiency of PSCs. The results show that the
device with round electrodes gives the best photovoltaic performance; in
contrast, the device with triangular electrodes reveals the worst properties.
Maximum almost twice increase in PCE with round electrode is obtained in the
devices compared with that of the triangular electrode. As a conclusion, the
electrode boundary curvature has a strong influence on the performance of PSCs.
The larger curvature, i.e. the sharper electrodes edge, maybe is a negative
effector on exciton separation and carrier transport in PSC system.


title: A formula for damping interarea oscillations with generator redispatch

abstract:
  We derive a new formula for the sensitivity of electromechanical oscillation
damping with respect to generator redispatch. The formula could lead to some
combination of observations, computations and heuristics to more effectively
damp interarea oscillations.


title:
Analysis of single-photon and linear amplifier detectors for microwave
  cavity dark matter axion searches

abstract:
  We show that at higher frequencies, and thus higher axion masses,
single-photon detectors become competitive and ultimately favored, when
compared to quantum-limited linear amplifiers, as the detector technology in
microwave cavity experimental searches for galactic halo dark matter axions.
The cross-over point in this comparison is of order 10 GHz ($\sim 40\ \mu$eV),
not far above the frequencies of current searches.


title:
Top-quark transverse-momentum distributions in t-channel single-top
  production

abstract:
  I present approximate next-to-next-to-leading-order (NNLO) top-quark
transverse momentum, pT, distributions in t-channel single-top production.
These distributions are derived from next-to-next-to-leading-logarithm (NNLL)
soft-gluon resummation. Theoretical results for the single top as well as the
single antitop pT distributions are shown for LHC and Tevatron energies.


title:
Towards scaling cosmological solutions with full coupled Horndeski
  Lagrangian: the KGB model

abstract:
  We study a general scalar field Lagrangian coupled with matter and linear in
$\Box\phi$ (also called KGB model). Within this class of models, we find the
most general form of the Lagrangian that allows for cosmological scaling
solutions, i.e. solutions where the ratio of matter to field density and the
equation of state remain constant. Scaling solutions of this kind may help
solving the coincidence problem since in this case the presently observed ratio
of matter to dark energy does not depend on initial conditions, but rather on
the theoretical parameters. Extending previous results we find that it is
impossible to join in a single solution a matter era and the scaling attractor.
This is an additional step towards finding the most general scaling Lagrangian
within the Horndeski class, i.e. general scalar-tensor models with second order
equations of motion.


title: The 4-Body Problem in a (1+1)-Dimensional Self-Gravitating System

abstract:
  We report on the results of a study of the motion of a four particle
non-relativistic one-dimensional self-gravitating system. We show that the
system can be visualized in terms of a single particle moving within a
potential whose equipotential surfaces are shaped like a box of pyramid-shaped
sides. As such this is the largest $N$-body system that can be visualized in
this way. We describe how to classify possible states of motion in terms of
Braid Group operators, generalizing this to $N$ bodies. We find that the
structure of the phase\textcolor{black}{{} space of each of these systems
yields a large variety of interesting dynamics, containing regions of
quasiperiodicity and chaos. Lyapunov exponents are calculated for many
trajectories to measure stochasticity and previously unseen phenomena in the
Lyapunov graphs are observed.

categories: gr-qc astro-ph.IM math-ph math.MP nlin.CD


title: The Multifractal Nature of Volterra-L\'{e}vy Processes

abstract:
  We consider the regularity of sample paths of Volterra-L\'{e}vy processes.
These processes are defined as stochastic integrals $$
M(t)=\int_{0}^{t}F(t,r)dX(r), \ \ t \in \mathds{R}_{+}, $$ where $X$ is a
L\'{e}vy process and $F$ is a deterministic real-valued function. We derive the
spectrum of singularities and a result on the 2-microlocal frontier of
$\{M(t)\}_{t\in [0,1]}$, under regularity assumptions on the function $F$.


title: Circuit QED with Hole-Spin Qubits in Ge/Si Nanowire Quantum Dots

abstract:
  We propose a setup for universal and electrically controlled quantum
information processing with hole spins in Ge/Si core/shell nanowire quantum
dots (NW QDs). Single-qubit gates can be driven through electric-dipole-induced
spin resonance, with spin-flip times shorter than 100 ps. Long-distance
qubit-qubit coupling can be mediated by the cavity electric field of a
superconducting transmission line resonator, where we show that operation times
below 20 ns seem feasible for the entangling square-root-of-iSWAP gate. The
absence of Dresselhaus spin-orbit interaction (SOI) and the presence of an
unusually strong Rashba-type SOI enable precise control over the transverse
qubit coupling via an externally applied, perpendicular electric field. The
latter serves as an on-off switch for quantum gates and also provides control
over the g factor, so single- and two-qubit gates can be operated
independently. Remarkably, we find that idle qubits are insensitive to charge
noise and phonons, and we discuss strategies for enhancing noise-limited gate
fidelities.


title:
Exploring the magnetoroton excitations in quantum wires: Inverse
  dielectric functions

abstract:
  A theoretical investigation has been made of the magnetoplasmon excitations
in a quantum wire characterized by a confining harmonic potential and subjected
to a perpendicular magnetic field. We study the (nonlocal, dynamic) inverse
dielectric function to examine the charge-density excitations within a
two-subband model in the framework of Bohm-Pines' random-phase approximation. A
particular stress is put on the (intersubband) magnetoroton excitation which
changes the sign of its group velocity twice before merging with the respective
single-particle continuum. It has already been suggested that the electronic
device based on such magnetoroton excitations can act as an {\it active} laser
medium [see, e.g., Phys. Rev. B {\bf 78}, 153306 (2008)]. Scrutinizing the real
and imaginary parts of the inverse dielectric function provides us with an
important information on the longitudinal and transverse (Hall) resistances of
the system.


title:
A group-theoretic viewpoint on Erdos-Falconer problems and the Mattila
  integral

abstract:
  We obtain nontrivial exponents for Erd\H os-Falconer type problems. Let
$T_k(E)$ denote the set of distinct congruent $k$-dimensional simplexes
determined by $(k+1)$-tuples of points from $E$. We prove that there exists
$s_0(d)<d$ such that, if $E \subset {\Bbb R}^d,\, d \ge 2$, with
$dim_{{\mathcal H}}(E)>s_0(d)$, then the ${k+1 \choose 2}$-dimensional Lebesgue
measure of $T_k(E)$ is positive. Results were previously obtained for triangles
in the plane \cite{GI12} and in higher dimensions \cite{GGIP12}. In this paper,
we improve upon those exponents, using a group-theoretic method that sheds new
light on the classical approach to these problems. The key to our approach is a
group action perspective which leads to natural and effective formulae related
to the classical Mattila integral.


title: Deceleration of SS433 radio jets

abstract:
  The mildly relativistic jets of SS\,433 are believed to inflate the
surrounding supernova remnant W\,50 depositing in its expansion possibly more
than 99% of their kinetic energy (\cite[1998]{Dub98}). Where and how this
transformation of energy is curried out, it is not yet known. What can we learn
from it that the jets decelerate and the deceleration is non-dissipative, i.e.
radiatively dark. In this paper we unclose the observed deviations of the
precessing radio jets of SS\,433, within a few arcseconds from a jets source,
from the ballistic track, described by the kinematic model, as a signature of
the deceleration which, on other hand, issues from the jets colliding with
ambient medium. For that we model kinematics of these colliding jets. The ram
pressure on the jets is estimated from the observed profile of brightness of
synchrotron radiation along the radio jets. We have found that to fit observed
locus the radio jets should be decelerated and twisted, additionally to the
precession twist, mostly within the first one-fifth of precession period, and
further they extend imitating ballistic jets. The fitted physical parameters of
the jet model turned out to be physically reliable and characteristic for
SS\,433 jets that unlikely to be occasional. This model explains naturally, and
meets approval by a) the observed shock-pressed morphology of the radio jets
and their brightness, b) the observed $\sim 10%$ deflections from the standard
kinematic model --- just a magnitude of the jet speed decrement in the model,
c) regularly observed for the radio jets the precession phase deviation from
the standard kinematic model prediction, d) dichotomy of distance to the
object, 4.8\,kpc vs. 5.5\,kpc, determined on the basis of the radio jets
kinematics on scales of a sub-arcsecond and several arcseconds.


title:
Precision Measurement of the e+e- --> K+K-(gamma) Cross Section with the
  Initial-State Radiation Method at BaBar

abstract:
  A precise measurement of the cross section for the process e+e- -->
K+K-(gamma) from threshold to an energy of 5 GeV is obtained with the
initial-state radiation (ISR) method using 232 fb^{-1} of data collected with
the BaBar detector at e+e- center-of-mass energies near 10.6 GeV. The
measurement uses the effective ISR luminosity determined from the e+e- -->
mu+mu-(gamma)gamma_ISR process with the same data set. The corresponding
lowest-order contribution to the hadronic vacuum polarization term in the muon
magnetic anomaly is found to be a_mu^{KK, LO}=(22.93 +- 0.18_{stat} +-
0.22_{syst}) * 10^{-10}. The charged kaon form factor is extracted and compared
to previous results. Its magnitude at large energy significantly exceeds the
asymptotic QCD prediction, while the measured slope is consistent with the
prediction.


title: Approximate Nearest Neighbor Search in $\ell_p$

abstract:
  We present a new locality sensitive hashing (LSH) algorithm for
$c$-approximate nearest neighbor search in $\ell_p$ with $1<p<2$. For a
database of $n$ points in $\ell_p$, we achieve $O(dn^{\rho})$ query time and
$O(dn+n^{1+\rho})$ space, where $\rho \le O((\ln c)^2/c^p)$. This improves upon
the previous best upper bound $\rho\le 1/c$ by Datar et al. (SOCG 2004), and is
close to the lower bound $\rho \ge 1/c^p$ by O'Donnell, Wu and Zhou (ITCS
2011). The proof is a simple generalization of the LSH scheme for $\ell_2$ by
Andoni and Indyk (FOCS 2006).


title:
Faster Deterministic Algorithms for Packing, Matching and $t$-Dominating
  Set Problems

abstract:
  In this paper, we devise three deterministic algorithms for solving the
$m$-set $k$-packing, $m$-dimensional $k$-matching, and $t$-dominating set
problems in time $O^*(5.44^{mk})$, $O^*(5.44^{(m-1)k})$ and $O^*(5.44^{t})$,
respectively. Although recently there has been remarkable progress on
randomized solutions to those problems, our bounds make good improvements on
the best known bounds for deterministic solutions to those problems.


title:
Accurate and efficient approximation to the optimized effective
  potential for exchange

abstract:
  We devise an efficient practical method for computing the Kohn-Sham
exchange-correlation potential corresponding to a Hartree-Fock electron
density. This potential is almost indistinguishable from the exact-exchange
optimized effective potential (OEP) and, when used as an approximation to the
OEP, is vastly better than all existing models. Using our method one can obtain
unambiguous, nearly exact OEPs for any finite one-electron basis set at the
same low cost as the Krieger-Li-Iafrate and Becke-Johnson potentials. For all
practical purposes, this solves the long-standing problem of black-box
construction of OEPs in exact-exchange calculations.


title: OFDM Synthetic Aperture Radar Imaging with Sufficient Cyclic Prefix

abstract:
  The existing linear frequency modulated (LFM) (or step frequency) and random
noise synthetic aperture radar (SAR) systems may correspond to the frequency
hopping (FH) and direct sequence (DS) spread spectrum systems in the past
second and third generation wireless communications. Similar to the current and
future wireless communications generations, in this paper, we propose OFDM SAR
imaging, where a sufficient cyclic prefix (CP) is added to each OFDM pulse. The
sufficient CP insertion converts an inter-symbol interference (ISI) channel
from multipaths into multiple ISI-free subchannels as the key in a wireless
communications system, and analogously, it provides an inter-range-cell
interference (IRCI) free (high range resolution) SAR image in a SAR system. The
sufficient CP insertion along with our newly proposed SAR imaging algorithm
particularly for the OFDM signals also differentiates this paper from all the
existing studies in the literature on OFDM radar signal processing. Simulation
results are presented to illustrate the high range resolution performance of
our proposed CP based OFDM SAR imaging algorithm.


title:
Pushing the glass transition towards random close packing using
  self-propelled hard spheres

abstract:
  Although the concept of random close packing with an almost universal packing
fraction of ~ 0.64 for hard spheres was introduced more than half a century
ago, there are still ongoing debates. The main difficulty in searching the
densest packing is that states with packing fractions beyond the glass
transition at ~ 0.58 are inherently non-equilibrium systems, where the dynamics
slows down with a structural relaxation time diverging with density; hence, the
random close packing is inaccessible. Here we perform simulations of
self-propelled hard spheres, and we find that with increasing activity the
relaxation dynamics can be sped up by orders of magnitude. The glass transition
shifts to higher packing fractions upon increasing the activity, allowing the
study of sphere packings with fluid-like dynamics at packing fractions close to
random close packing. Our study opens new possibilities of investigating dense
packings and the glass transition in systems of hard particles.


title: Translation surfaces with no convex presentation

abstract:
  We give infinite lists of translations surfaces with no convex presentations.
We classify the surfaces in the stratum H(2) which do not have convex
presentations, as well as those with no strictly convex presentations. We show
that in H(1,1), all surfaces in the eigenform loci E_4, E_9 or E_{16} have no
strictly convex presentation, and that the list of surfaces with no convex
presentations in H(1,1) - (E_4 union E_9 union E_{16}) is finite and consists
of square-tiled surfaces. We prove the existence of non-lattice surfaces
without strictly convex presentations in all of the strata H^{(hyp)}(g-1, g-1).


title: Human pitch is pre-cortical: The essential role of the cochlear fluid

abstract:
  The perceived pitch of a complex harmonic sound changes if the partials of
the sound are frequency-shifted by a fixed amount. Simple mathematical rules
that the perceived pitch could be expected to follow ('first pitch-shift') are
violated in psychoacoustic experiments ('second pitchshift'). For this,
commonly cognitive cortical processes were held responsible. Here, we show that
human pitch perception can be reproduced from a minimal, purely biophysical,
model of the cochlea, by fully recovering the psychoacoustical pitch-shift data
of G.F. Smoorenburg (1970) and related physiological measurements from the cat
cochlear nucleus. For this to happen, the cochlear fluid plays a distinguished
role.


title: The Two Sources of Solar Energetic Particles

abstract:
  Evidence for two different physical mechanisms for acceleration of solar
energetic particles (SEPs) arose 50 years ago with radio observations of type
III bursts, produced by outward streaming electrons, and type II bursts from
coronal and interplanetary shock waves. Since that time we have found that the
former are related to "impulsive" SEP events from impulsive flares or jets.
Here, resonant stochastic acceleration, related to magnetic reconnection
involving open field lines, produces not only electrons but 1000-fold
enhancements of 3He/4He and of (Z>50)/O. Alternatively, in "gradual" SEP
events, shock waves, driven out from the Sun by coronal mass ejections (CMEs),
more democratically sample ion abundances that are even used to measure the
coronal abundances of the elements. Sometimes residual impulsive suprathermal
ions contribute to the seed population for shock acceleration, complicating the
abundance picture, but this process has now been modeled theoretically.
Initially, impulsive events define a point source on the Sun, selectively
filling few magnetic flux tubes, while gradual events show broad acceleration
that can fill half of the inner heliosphere, beginning when the shock reaches
~2 solar radii. Shock acceleration occurs as ions are scattered back and forth
across the shock by resonant Alfven waves amplified by the accelerated protons
themselves. These waves also can produce a streaming-limited maximum SEP
intensity and plateau region upstream of the shock. Behind the shock lies the
large expanse of the "reservoir", a spatially extensive trapped volume of
uniform SEP intensities with invariant energy-spectral shapes where overall
intensities decrease with time as the enclosing "magnetic bottle" expands
adiabatically. These reservoirs now explain the slow intensity decrease that
defines gradual events, once erroneously attributed solely to slow outward
diffusion.


title: Volume Ratio, Sparsity, and Minimaxity under Unitarily Invariant Norms

abstract:
  The current paper presents a novel machinery for studying non-asymptotic
minimax estimation of high-dimensional matrices, which yields tight minimax
rates for a large collection of loss functions in a variety of problems.
  Based on the convex geometry of finite-dimensional Banach spaces, we first
develop a volume ratio approach for determining minimax estimation rates of
unconstrained normal mean matrices under all squared unitarily invariant norm
losses. In addition, we establish the minimax rates for estimating mean
matrices with submatrix sparsity, where the sparsity constraint introduces an
additional term in the rate whose dependence on the norm differs completely
from the rate of the unconstrained problem. Moreover, the approach is
applicable to the matrix completion problem under the low-rank constraint.
  The new method also extends beyond the normal mean model. In particular, it
yields tight rates in covariance matrix estimation and Poisson rate matrix
estimation problems for all unitarily invariant norms.


title: Thresholds of Spatially Coupled Systems via Lyapunov's Method

abstract:
  The threshold, or saturation phenomenon of spatially coupled systems is
revisited in the light of Lyapunov's theory of dynamical systems. It is shown
that an application of Lyapunov's direct method can be used to quantitatively
describe the threshold phenomenon, prove convergence, and compute threshold
values. This provides a general proof methodology for the various systems
recently studied. Examples of spatially coupled systems are given and their
thresholds are computed.


title: Geodesics in a Graph of Perfect Matchings

abstract:
  Let $\mathscr{P}_{m}$ be the graph on the set of perfect matchings in the
complete graph $K_{2m}$, where two perfect matchings are connected by an edge
if their symmetric difference is a cycle of length four. This paper studies
geodesics in $\mathscr{P}_{m}$. The diameter of $\mathscr{P}_{m}$, as well as
the eccentricity of each vertex, are shown to be $m-1$. Two proof are given to
show that the number of geodesics between any two antipodes is $m^{m-2}$. The
first is a direct proof via a recursive formula, and the second is via
reduction to the number of minimal factorizations of a given $m$-cycle in the
symmetric group $S_m$. An explicit formula for the number of geodesics between
any two matchings in $\mathscr{P}_{m}$ is also given.
  Let $\mathscr{M}_m$ be the graph on the set of non-crossing perfect matchings
of $2m$ labeled points on a circle with the same adjacency condition as in
$\mathscr{P}_m$. $\mathscr{M}_m$ is an induced subgraph of $\mathscr{P}_m$, and
it is shown that $\mathscr{M}_m$ has exactly one pair of antipodes having the
maximal number ($m^{m-2}$) of geodesics between them.


title:
The Role of Emotions in Contributors Activity: A Case Study on the
  GENTOO Community

abstract:
  We analyse the relation between the emotions and the activity of contributors
in the Open Source Software project Gentoo. Our case study builds on extensive
data sets from the project's bug tracking platform Bugzilla, to quantify the
activity of contributors, and its mail archives, to quantify the emotions of
contributors by means of sentiment analysis. The Gentoo project is known for a
period of centralization within its bug triaging community. This was followed
by considerable changes in community organization and performance after the
sudden retirement of the central contributor. We analyse how this event
correlates with the negative emotions, both in bilateral email discussions with
the central contributor, and at the level of the whole community of
contributors. We then extend our study to consider the activity patterns on
Gentoo contributors in general. We find that contributors are more likely to
become inactive when they express strong positive or negative emotions in the
bug tracker, or when they deviate from the expected value of emotions in the
mailing list. We use these insights to develop a Bayesian classifier that
detects the risk of contributors leaving the project. Our analysis opens new
perspectives for measuring online contributor motivation by means of sentiment
analysis and for real-time predictions of contributor turnover in Open Source
Software projects.


title: Extensions of Current Groups on S^3 and the Adjoint Representations

abstract:
  Let Omega^3(SU(n)) be the Lie group of based mappings from S^3 to SU(n). We
construct a Lie group extension of Omega^3(SU(n)) for n>2 by the abelian group
of the affine dual space of SU(n)-connections on S^3. In this article we give
several improvement of J. Mickelsson's results in 1987, especially we give a
precise description of the extension of those components that are not the
identity component,. We also correct several argument about the extension of
Omega^3(SU(2)) which seems not to be exact in Mickelsson's work, though his
observation about the fact that the extension of Omega^3(SU(2)) reduces to the
extension by Z_2 is correct. Then we shall investigate the adjoint
representation of the Lie group extension of Omega^3(SU(n)) for n>2.


title:
Chemical Analysis of the Ninth Magnitude Carbon-Enhanced Metal-Poor Star
  BD+44 493

abstract:
  We present detailed chemical abundances for the bright carbon-enhanced
metal-poor (CEMP) star BD+44 493, previously reported on by Ito et al. Our
measurements confirm that BD+44 493 is an extremely metal-poor ([Fe/H]=-3.8)
subgiant star with excesses of carbon and oxygen. No significant excesses are
found for nitrogen and neutron-capture elements (the latter of which place it
in the CEMP-no class of stars). Other elements that we measure exhibit
abundance patterns that are typical for non-CEMP extremely metal-poor stars. No
evidence for variations of radial velocity have been found for this star. These
results strongly suggest that the carbon enhancement in BD+44 493 is unlikely
to have been produced by a companion asymptotic giant-branch star and
transferred to the presently observed star, nor by pollution of its natal
molecular cloud by rapidly-rotating, massive, mega metal-poor ([Fe/H] < -6.0)
stars. A more likely possibility is that this star formed from gas polluted by
the elements produced in a "faint" supernova, which underwent mixing and
fallback, and only ejected small amounts of elements of metals beyond the
lighter elements. The Li abundance of BD+44 493 (A(Li)=log(Li/H)+12=1.0) is
lower than the Spite plateau value, as found in other metal-poor subgiants. The
upper limit on Be abundance (A(Be)=log(Be/H)+12<-1.8) is as low as those found
for stars with similarly extremely-low metallicity, indicating that the
progenitors of carbon- (and oxygen-) enhanced stars are not significant sources
of Be, or that Be is depleted in metal-poor subgiants with effective
temperatures of ~5400K.


title:
Seasonal Variations in Relative Weight of Lake Trout (Salvelinus
  namaycush), Kokanee Salmon (Oncorhynchus nerka), Rainbow Trout (Onocorhynchus
  mykiss), and Brown Trout (Salmo trutta) in Blue Mesa Reservoir, Colorado

abstract:
  Blue Mesa Reservoir is the largest body of water in Colorado and is located
on the western slope of the Rocky Mountains at an elevation of 7520 feet. Blue
Mesa Reservoir contains recreationally important populations of lake trout
(Salvelinus namaycush), kokanee salmon (Oncorhynchus nerka), rainbow trout
(Onocorhynchus mykiss), and brown trout (Salmo trutta). A management challenge
in recent years has been the overpopulation of lake trout, which has led to a
steep decline in abundance of kokanee salmon (a preferred food source) followed
by a steep decline in body condition of the lake trout. Relative weight, Wr, is
commonly used to assess body condition and prey availability of fish in a
variety of ecosystems, but its seasonal variability has not been well
documented in cold water species. Relative weight is 100 times the actual
weight of a fish divided by expected weight (or standard weight) of that
species at the measured total length. The present study uses multi-year,
multi-season length and weight data provided by the Colorado Department of
Parks and Wildlife to quantify seasonal variations in mean relative weight in
these four species. It is found that lake trout consistently lose significant
body condition between the spring and the fall of a given year, with a mean
loss in relative weight of 11.7 +/- 2.4. In contrast, kokanee salmon tend to
gain significant body condition between spring and fall with a mean gain in
relative weight of 5.2 +/- 2.9. Rainbow trout tend to lose body condition
between summer and fall with a mean loss of relative weight of 7.4 +/- 1.7.
Brown trout tend to gain body condition between spring and fall with a mean
gain of 5.6 +/- 1.8. These findings can be interpreted in terms of the feeding
habits, forage availability, and metabolic activity of each species.


title:
Time-dependent density-functional theory of exciton-exciton correlations
  in the nonlinear optical response

abstract:
  We analyze possible nonlinear exciton-exciton correlation effects in the
optical response of semiconductors by using a time-dependent density-functional
theory (TDDFT) approach. For this purpose, we derive the nonlinear
(third-order) TDDFT equation for the excitonic polarization. In this equation,
the nonlinear time-dependent effects are described by the time-dependent
(non-adiabatic) part of the effective exciton-exciton interaction, which
depends on the exchange-correlation (XC) kernel. We apply the approach to study
the nonlinear optical response of a GaAs quantum well. In particular, we
calculate the 2D Fourier spectra of the system and compare it with experimental
data. We find that it is necessary to use a non-adiabatic XC kernel to describe
excitonic bound states - biexcitons, which are formed due to the retarded TDDFT
exciton-exciton interaction.


title: Topology of the Standard Model, I: Fermions

abstract:
  The Harari-Shupe model for fermions is extended to a topological model which
contains an explanation for the observed fact that there are only three
generations of fermions. Topological explanations are given for $\beta$-decay
and for proton decay predicted in supersymmetry and string theories. An
explanation is given for the observed fact that the three generations of
fermions have such similar properties. The concept of "color" is incorporated
into the model in a topologically meaningful way. Conservation laws are defined
and discussed in the context of the algebraic topology of the model, and preon
number is proved to be linearly determined by charge, weak isospin, and color.


title: Theoretical Bounds in Minimax Decentralized Hypothesis Testing

abstract:
  Minimax decentralized detection is studied under two scenarios: with and
without a fusion center when the source of uncertainty is the Bayesian prior.
When there is no fusion center, the constraints in the network design are
determined. Both for a single decision maker and multiple decision makers, the
maximum loss in detection performance due to minimax decision making is
obtained. In the presence of a fusion center, the maximum loss of detection
performance between with- and without fusion center networks is derived
assuming that both networks are minimax robust. The results are finally
generalized.


title:
Environmental and fishing effects on the dynamic of brown tiger prawn
  (Penaeus esculentus) in Moreton Bay (Australia)

abstract:
  This analysis of the variations of brown tiger prawn (Penaeus esculentus)
catch in the Moreton Bay multispecies trawl fishery estimated catchability
using a delay difference model. It integrated several factors responsible for
variations in catchability: targeting of fishing effort, increasing fishing
power and changing availability. An analysis of covariance was used to define
fishing events targeted at brown tiger prawns. A general linear model estimated
inter-annual variations of fishing power. Temperature induced changes in prawn
behaviour played an important role in the dynamic of this fishery. Maximum
likelihood estimates of targeted catchability ($3.92 \pm 0.40 \ 10^{-4}$
boat-days$^{-1}$) were twice as large as non-targeted catchability ($1.91 \pm
0.24 \ 10^{-4}$ boat-days$^{-1}$). The causes of recent decline in fishing
effort in this fishery were discussed.


title:
Propagation of seismic waves through a spatio-temporally fluctuating
  medium: Homogenization

abstract:
  Measurements of seismic wave travel times at the photosphere of the Sun have
enabled inferences of its interior structure and dynamics. In interpreting
these measurements, the simplifying assumption that waves propagate through a
temporally stationary medium is almost universally invoked. However, the Sun is
in a constant state of evolution, on a broad range of spatio-temporal scales.
At the zero wavelength limit, i.e., when the wavelength is much shorter than
the scale over which the medium varies, the WKBJ (ray) approximation may be
applied. Here, we address the other asymptotic end of the spectrum, the
infinite wavelength limit, using the technique of homogenization. We apply
homogenization to scenarios where waves are propagating through rapidly varying
media (spatially and temporally), and derive effective models for the media.
One consequence is that a scalar sound speed becomes a tensorial wavespeed in
the effective model and anisotropies can be induced depending on the nature of
the perturbation. The second term in this asymptotic two-scale expansion, the
so-called corrector, contains contributions due to higher-order scattering,
leading to the decoherence of the wavefield. This decoherence may be causally
linked to the observed wave attenuation in the Sun. Although the examples we
consider here consist of periodic arrays of perturbations to the background,
homogenization may be extended to ergodic and stationary random media. This
method may have broad implications for the manner in which we interpret seismic
measurements in the Sun and for modeling the effects of granulation on the
scattering of waves and distortion of normal-mode eigenfunctions.


title: Notes On Holomorphic String And Superstring Theory Measures Of Low Genus

abstract:
  It has long been known that in principle, the genus g vacuum amplitude for
bosonic strings or superstrings in 26 or 10 dimensions can be entirely
determined from conditions of holomorphy. Moreover, this has been done in
practice for bosonic strings of low genus. Here we describe in a unified way
how to determine the bosonic string and superstring vacuum amplitude in genus 1
and 2 via holomorphy. The main novelty is the superstring analysis in genus 2,
where we use holomorphy to get a new understanding of some of the results that
previously have been obtained by more explicit calculations.


title:
A Differential Feedback Scheme Exploiting the Temporal and Spectral
  Correlation

abstract:
  Channel state information (CSI) provided by limited feedback channel can be
utilized to increase the system throughput. However, in multiple input multiple
output (MIMO) systems, the signaling overhead realizing this CSI feedback can
be quite large, while the capacity of the uplink feedback channel is typically
limited. Hence, it is crucial to reduce the amount of feedback bits. Prior work
on limited feedback compression commonly adopted the block fading channel model
where only temporal or spectral correlation in wireless channel is considered.
In this paper, we propose a differential feedback scheme with full use of the
temporal and spectral correlations to reduce the feedback load. Then, the
minimal differential feedback rate over MIMO doubly selective fading channel is
investigated. Finally, the analysis is verified by simulations.


title: KK-lifting problem for dimension drop interval algebras

abstract:
  We investigate the KK-lifting problem for generalized dimension drop interval
algebras (with possibly different dimension drops at the endpoints). It turns
out that there exist KK-elements between two such algebras which preserve the
Dadarlat-Loring order structure on K-theory with coefficient, but fail to be
lifted to a homomorphism between the algebras.


title:
Reporting an Experience on Design and Implementation of e-Health Systems
  on Azure Cloud

abstract:
  Electronic Health (e-Health) technology has brought the world with
significant transformation from traditional paper-based medical practice to
Information and Communication Technologies (ICT)-based systems for automatic
management (storage, processing, and archiving) of information. Traditionally
e-Health systems have been designed to operate within stovepipes on dedicated
networks, physical computers, and locally managed software platforms that make
it susceptible to many serious limitations including: 1) lack of on-demand
scalability during critical situations; 2) high administrative overheads and
costs; and 3) in-efficient resource utilization and energy consumption due to
lack of automation. In this paper, we present an approach to migrate the ICT
systems in the e-Health sector from traditional in-house Client/Server (C/S)
architecture to the virtualised cloud computing environment. To this end, we
developed two cloud-based e-Health applications (Medical Practice Management
System and Telemedicine Practice System) for demonstrating how cloud services
can be leveraged for developing and deploying such applications. The Windows
Azure cloud computing platform is selected as an example public cloud platform
for our study. We conducted several performance evaluation experiments to
understand the Quality Service (QoS) tradeoffs of our applications under
variable workload on Azure.


title: Fluctuations of the Bose-Einstein condensate

abstract:
  This article gives a rigorous analysis of the fluctuations of the
Bose-Einstein condensate for a system of non-interacting bosons in an arbitrary
potential, assuming that the system is governed by the canonical ensemble. As a
result of the analysis, we are able to tell the order of fluctuations of the
condensate fraction as well as its limiting distribution upon proper centering
and scaling. This yields interesting results. For example, for a system of $n$
bosons in a 3D harmonic trap near the transition temperature, the order of
fluctuations of the condensate fraction is $n^{-1/2}$ and the limiting
distribution is normal, whereas for the 3D uniform Bose gas, the order of
fluctuations is $n^{-1/3}$ and the limiting distribution is an explicit
non-normal distribution. For a 2D harmonic trap, the order of fluctuations is
$n^{-1/2}(\log n)^{1/2}$, which is larger than $n^{-1/2}$ but the limiting
distribution is still normal. All of these results come as easy consequences of
a general theorem.


title: Describe Prime number gaps pattern by Logistic mapping

abstract:
  Based on symbolic dynamics methods, we show the primes gap pattern could be
described by the chaos orbit of Logistic mapping X(k+1)=1-uX(k)^2, u=1.5437. If
so, there will be arbitrarily many twin primes.


title:
Bayesian test of significance for conditional independence: The
  multinomial model

abstract:
  Conditional independence tests (CI tests) have received special attention
lately in Machine Learning and Computational Intelligence related literature as
an important indicator of the relationship among the variables used by their
models. In the field of Probabilistic Graphical Models (PGM)--which includes
Bayesian Networks (BN) models--CI tests are especially important for the task
of learning the PGM structure from data. In this paper, we propose the Full
Bayesian Significance Test (FBST) for tests of conditional independence for
discrete datasets. FBST is a powerful Bayesian test for precise hypothesis, as
an alternative to frequentist's significance tests (characterized by the
calculation of the \emph{p-value}).


title: Euler Equations Related to the Generalized Neveu-Schwarz Algebra

abstract:
  In this paper, we study supersymmetric or bi-superhamiltonian Euler equations
related to the generalized Neveu-Schwarz algebra. As an application, we obtain
several supersymmetric or bi-superhamiltonian generalizations of some
well-known integrable systems including the coupled KdV equation, the
2-component Camassa-Holm equation and the 2-component Hunter-Saxton equation.
To our knowledge, most of them are new.


title:
The 2D Incompressible Magnetohydrodynamics Equations with only Magnetic
  Diffusion

abstract:
  This paper examines the global (in time) regularity of classical solutions to
the 2D incompressible magnetohydrodynamics (MHD) equations with only magnetic
diffusion. Here the magnetic diffusion is given by the fractional Laplacian
operator $(-\Delta)^\beta$. We establish the global regularity for the case
when $\beta>1$. This result significantly improves previous work which requires
$\beta>\frac32$ and brings us closer to the resolution of the well-known global
regularity problem on the 2D MHD equations with standard Laplacian magnetic
diffusion, namely the case when $\beta=1$.


title: Rigidity of Infinite Hexagonal Triangulation of the Plane

abstract:
  In the paper, we consider the rigidity problem of the infinite hexagonal
triangulation of the plane under the piecewise linear conformal changes
introduced by Luo in [5]. Our result shows that if a geometric hexagonal
triangulation of the plane is PL conformal to the regular hexagonal
triangulation and all inner angles are in $[\delta, \pi/2 -\delta]$ for any
constant $\delta > 0$, then it is the regular hexagonal triangulation. This
partially solves a conjecture of Luo [4]. The proof uses the concept of
\emph{quasi-harmonic} functions to unfold the properties of the mesh.


title:
Viscosity solutions of obstacle problems for Fully nonlinear
  path-dependent PDEs

abstract:
  In this article, we adapt the definition of viscosity solutions to the
obstacle problem for fully nonlinear path-dependent PDEs with data uniformly
continuous in $(t,\omega)$, and generator Lipschitz continuous in
$(y,z,\gamma)$. We prove that our definition of viscosity solutions is
consistent with the classical solutions, and satisfy a stability result. We
show that the value functional defined via the second order reflected backward
stochastic differential equation is the unique viscosity solution of the
variational inequalities.


title: The Eisenstein ideal and Jacquet-Langlands isogeny over function fields

abstract:
  Let $\frak{p}$ and $\frak{q}$ be two distinct prime ideals of
$\mathbb{F}_q[T]$. We use the Eisenstein ideal of the Hecke algebra of the
Drinfeld modular curve $X_0(\frak{p}\frak{q})$ to compare the rational torsion
subgroup of the Jacobian $J_0(\frak{p}\frak{q})$ with its subgroup generated by
the cuspidal divisors, and to produce explicit examples of Jacquet-Langlands
isogenies. Our results are stronger than what is currently known about the
analogues of these problems over $\mathbb{Q}$.


title:
Establishment of thermodynamic equilibrium in cosmological model with an
  arbitrary acceleration

abstract:
  It has been built a strict mathematical model of the thermodynamic
equilibrium's establishment in the originally nonequilibrium cosmological
ultrarelativistic plasma for the arbitrary accelerated Universe under the
assumption that scaling of interactions of elementary particles is restored at
energies above the unitary limit. It is shown, that in case of Universe
positive acceleration, thermodynamic equilibrium never can be completely
restored.


title: Poisson structures and star products on quasimodular forms

abstract:
  We construct and classify all Poisson structures on quasimodular forms that
extend the one coming from the first Rankin-Cohen bracket on the modular forms.
We use them to build formal deformations on the algebra of quasimodular forms.


title:
A Quenched Functional Central Limit Theorem for Planar Random Walks in
  Random Sceneries

abstract:
  Random walks in random sceneries (RWRS) are simple examples of stochastic
processes in disordered media. They were introduced at the end of the 70's by
Kesten-Spitzer and Borodin, motivated by the construction of new self-similar
processes with stationary increments. Two sources of randomness enter in their
definition: a random field $\xi = (\xi_x)_{x \in \Z^d}$ of i.i.d.\ random
variables, which is called the \emph{random scenery}, and a random walk $S =
(S_n)_{n \in \N}$ evolving in $\Z^d$, independent from the scenery. The RWRS $Z
= (Z_n)_{n \in \N}$ is then defined as the accumulated scenery along the
trajectory of the random walk, i.e., $Z_n := \sum_{k=1}^n \xi_{S_k}$. The law
of $Z$ under the joint law of $\xi$ and $S$ is called "annealed", and the
conditional law given $\xi$ is called "quenched". Recently, central limit
theorems under the quenched law were proved for $Z$ by the first two authors
for a class of transient random walks including walks with finite variance in
dimension $d \ge 3$. In this paper we extend their results to dimension $d=2$.


title: Differential meta-analysis of RNA-seq data from multiple studies

abstract:
  High-throughput sequencing is now regularly used for studies of the
transcriptome (RNA-seq), particularly for comparisons among experimental
conditions. For the time being, a limited number of biological replicates are
typically considered in such experiments, leading to low detection power for
differential expression. As their cost continues to decrease, it is likely that
additional follow-up studies will be conducted to re-address the same
biological question. We demonstrate how p-value combination techniques
previously used for microarray meta-analyses can be used for the differential
analysis of RNA-seq data from multiple related studies. These techniques are
compared to a negative binomial generalized linear model (GLM) including a
fixed study effect on simulated data and real data on human melanoma cell
lines. The GLM with fixed study effect performed well for low inter-study
variation and small numbers of studies, but was outperformed by the
meta-analysis methods for moderate to large inter-study variability and larger
numbers of studies. To conclude, the p-value combination techniques illustrated
here are a valuable tool to perform differential meta-analyses of RNA-seq data
by appropriately accounting for biological and technical variability within
studies as well as additional study-specific effects. An R package metaRNASeq
is available on the R Forge.


title:
Asymptotic stability of a nonlinear Korteweg-de Vries equation with a
  critical length

abstract:
  We study an initial-boundary-value problem of a nonlinear Korteweg-de Vries
equation posed on a finite interval (0,2pi). The whole system has Dirichlet
boundary condition at the left end-point, and both of Dirichlet and Neumann
homogeneous boundary conditions at the right end-point. It is known that the
origin is not asymptotically stable for the linearized system around the
origin. We prove that the origin is (locally) asymptotically stable for the
nonlinear system.


title:
Inverse scattering at high energies for the multidimensional Newton
  equation in a long range potential

abstract:
  We define scattering data for the Newton equation in a potential $V\in
C^2(\R^n,\R)$, $n\ge2$, that decays at infinity like $r^{-\alpha}$ for some
$\alpha\in (0,1]$. We provide estimates on the scattering solutions and
scattering data and we prove, in particular, that the scattering data at high
energies uniquely determine the short range part of the potential up to the
knowledge of the long range tail of the potential. The Born approximation at
fixed energy of the scattering data is also considered. We then change the
definition of the scattering data to study inverse scattering in other
asymptotic regimes. These results were obtained by developing the inverse
scattering approach of [Novikov, 1999].


title:
Rigorous investigation of the reduced density matrix for the ideal Bose
  gas in harmonic traps by a loop-gas-like approach

abstract:
  In this paper, we rigorously investigate the reduced density matrix (RDM)
associated to the ideal Bose gas in harmonic traps. We present a method based
on a sum-decomposition of the RDM allowing to treat not only the isotropic
trap, but also general anisotropic traps. When focusing on the isotropic trap,
the method is analogous to the loop-gas approach developed by W.J. Mullin in
[38]. Turning to the case of anisotropic traps, we examine the RDM for some
anisotropic trap models corresponding to some quasi-1D and quasi-2D regimes.
For such models, we bring out an additional contribution in the local density
of particles which arises from the mesoscopic loops. The close connection with
the occurrence of generalized-BEC is discussed. Our loop-gas-like approach
provides relevant information which can help guide numerical investigations on
highly anisotropic systems based on the Path Integral Monte Carlo (PIMC)
method.

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


title:
Alpha, Betti and the Megaparsec Universe: on the Topology of the Cosmic
  Web

abstract:
  We study the topology of the Megaparsec Cosmic Web in terms of the
scale-dependent Betti numbers, which formalize the topological information
content of the cosmic mass distribution. While the Betti numbers do not fully
quantify topology, they extend the information beyond conventional cosmological
studies of topology in terms of genus and Euler characteristic. The richer
information content of Betti numbers goes along the availability of fast
algorithms to compute them.
  For continuous density fields, we determine the scale-dependence of Betti
numbers by invoking the cosmologically familiar filtration of sublevel or
superlevel sets defined by density thresholds. For the discrete galaxy
distribution, however, the analysis is based on the alpha shapes of the
particles. These simplicial complexes constitute an ordered sequence of nested
subsets of the Delaunay tessellation, a filtration defined by the scale
parameter, $\alpha$. As they are homotopy equivalent to the sublevel sets of
the distance field, they are an excellent tool for assessing the topological
structure of a discrete point distribution. In order to develop an intuitive
understanding for the behavior of Betti numbers as a function of $\alpha$, and
their relation to the morphological patterns in the Cosmic Web, we first study
them within the context of simple heuristic Voronoi clustering models.
  Subsequently, we address the topology of structures emerging in the standard
LCDM scenario and in cosmological scenarios with alternative dark energy
content. The evolution and scale-dependence of the Betti numbers is shown to
reflect the hierarchical evolution of the Cosmic Web and yields a promising
measure of cosmological parameters. We also discuss the expected Betti numbers
as a function of the density threshold for superlevel sets of a Gaussian random
field.


title: Remez-Type Inequality for Smooth Functions

abstract:
  The classical Remez inequality bounds the maximum of the absolute value of a
polynomial $P(x)$ of degree $d$ on $[-1,1]$ through the maximum of its absolute
value on any subset $Z$ of positive measure in $[-1,1]$. Similarly, in several
variables the maximum of the absolute value of a polynomial $P(x)$ of degree
$d$ on the unit ball $B^n \subset {\mathbb R}^n$ can be bounded through the
maximum of its absolute value on any subset $Z\subset Q^n_1$ of positive
$n$-measure $m_n(Z)$. In \cite{Yom} a stronger version of Remez inequality was
obtained: the Lebesgue $n$-measure $m_n$ was replaced by a certain geometric
quantity $\omega_{n,d}(Z)$ satisfying $\omega_{n,d}(Z)\geq m_n(Z)$ for any
measurable $Z$. The quantity $\omega_{n,d}(Z)$ can be effectively estimated in
terms of the metric entropy of $Z$ and it may be nonzero for discrete and even
finite sets $Z$.
  In the present paper we extend Remez inequality to functions of finite
smoothness. This is done by combining the result of \cite{Yom} with the Taylor
polynomial approximation of smooth functions. As a consequence we obtain
explicit lower bounds in some examples in the Whitney problem of a $C^k$-smooth
extrapolation from a given set $Z$, in terms of the geometry of $Z$.