title:
Microscopic and thermodynamic evaluation of vesicles shed by
  erythrocytes at elevated temperatures

abstract:
  Erythrocytes and vesicles shed by erythrocytes from human and rat blood were
collected and analyzed after temperature was elevated by physical exercise or
by exposure to external heat. The images of erythrocytes and vesicles were
analyzed by the light microscopy system with spatial resolution of better than
90 nm. The samples were observed in an aqueous environment and required no
freezing, dehydration, staining, shadowing, marking or any other manipulation.
Temperature elevation, whether passive or through exercise, resulted in
significant concentration increase of structurally transformed erythrocytes
(echinocytes) and vesicles in blood. At temperature of 37 oC, mean vesicle
concentrations and diameters in human and rat blood were (1.50+-0.35)x10^6 and
(1.4+-0.2)x10^6 vesicles/{\mu}L, and 0.365+-0.065 and 0.436+-0.03 {\mu}m,
respectively. It was estimated that 80% of all vesicles found in human blood
are smaller than 0.4 {\mu}m. Thermodynamic analysis of experimental and
literature data showed that erythrocyte transformation, vesicle release and
other associated processes are driven by entropy with enthalpy-entropy
compensation. It is suggested that physical state of hydrated cell membrane is
responsible for the compensation. The increase of vesicle number related to
elevated temperatures may be indicative of the heat stress level and serve as
diagnostic of erythrocyte stability and human performance.


title:
Tailoring the electronic texture of a topological insulator via its
  surface orientation

abstract:
  Three dimensional topological insulator crystals consist of an insulating
bulk enclosed by metallic surfaces, and detailed theoretical predictions about
the surface state band topology and spin texture are available. While several
topological insulator materials are currently known, the existence and topology
of these metallic states have only ever been probed for one particular surface
orientation of a given material. For most topological insulators, such as
Bi$_{1-x}$Sb$_{x}$ and Bi$_2$Se$_3$, this surface is the closed-packed (111)
surface and it supports one topologically guaranteed surface state Dirac cone.
Here we experimentally realise a non closed-packed surface of a topological
insulator, Bi$_{1-x}$Sb$_{x}$(110), and probe the surface state topology by
angle-resolved photoemission. As expected, this surface also supports metallic
states but the change in surface orientation drastically modifies the band
topology, leading to three Dirac cones instead of one, in excellent agreement
with the theoretical predictions but in contrast to any other experimentally
studied TI surface. This illustrates the possibility to tailor the basic
topological properties of the surface via its crystallographic direction. Here
it introduces a valley degree of freedom not previously achieved for
topological insulator systems.


title: On the Metric of Space-time

abstract:
  Maxwell's equations are obeyed in a one-parameter group of isotropic
gravity-free flat space-times whose metric depends upon the value of the group
parameter. An experimental determination of this value has been proposed. If it
is zero, the metric is Minkowski's. If it is non-zero, the metric is not
Poincare invariant and local frequencies of electromagnetic waves change as
they propagate. If the group parameter is positive, velocity independent red
shifts develop and the group parameter plays a role similar to that of Hubble's
constant in determining the relation of these redshifts to propagation
distance. In the resulting space-times, the velocity dependence of Doppler
shifts is a function of propagation distance. If the group parameter and
Hubble's constant have the same order of magnitude, observed frequency shifts
in radiation received from stellar sources can imply source velocities quite
different from those implied in Minkowski space. In these space-times,
electromagnetic waves received from bodies in galactic Kepler orbits undergo
frequency shifts which are indistinguishable from shifts currently attributed
to dark matter and dark energy in Minkowski space, or to a non-Newtonian
physics.


title: Towards efficient decoding of classical-quantum polar codes

abstract:
  Known strategies for sending bits at the capacity rate over a general channel
with classical input and quantum output (a cq channel) require the decoder to
implement impractically complicated collective measurements. Here, we show that
a fully collective strategy is not necessary in order to recover all of the
information bits. In fact, when coding for a large number N uses of a cq
channel W, N I(W_acc) of the bits can be recovered by a non-collective strategy
which amounts to coherent quantum processing of the results of product
measurements, where I(W_acc) is the accessible information of the channel W. In
order to decode the other N (I(W) - I(W_acc)) bits, where I(W) is the Holevo
rate, our conclusion is that the receiver should employ collective
measurements. We also present two other results: 1) collective Fuchs-Caves
measurements (quantum likelihood ratio measurements) can be used at the
receiver to achieve the Holevo rate and 2) we give an explicit form of the
Helstrom measurements used in small-size polar codes. The main approach used to
demonstrate these results is a quantum extension of Arikan's polar codes.


title: The category and operad of matching dialgebras

abstract:
  This paper gives a systematic study of matching dialgebras corresponding to
the operad $As^{(2)}$ in \cite{Zi} as the only Koszul self dual operad there
other than the operads of associative algebras and Poisson algebras. The close
relationship of matching dialgebras with semi-homomorphisms and matched pairs
of associative algebras are established. By anti-symmetrizing, matching
dialgerbas are also shown to give compatible Lie algebras, pre-Lie algebras and
PostLie algebras. By the rewriting method, the operad of matching dialgebras is
shown to be Koszul and the free objects are constructed in terms of tensor
algebras. The operadic complex computing the homology of the matching
dialgebras is made explicit.


title: Homogenization: in Mathematics or Physics?

abstract:
  Homogenization appeared more than 100 years ago. It is an approach to study
the macro-behavior of a medium by its micro-properties. In mathematics,
homogenization theory considers the limitations of the sequences of the
problems and its solutions when a parameter tends to zero. This parameter is
regarded as the ratio of the characteristic size in the micro scale to that in
the macro scale. So what is considered is a sequence of problems in a fixed
domain while the characteristic size in micro scale tends to zero. But for the
real situations in physics or engineering, the micro scale of a medium is fixed
and can not be changed. In the process of homogenization, it is the size in
macro scale which becomes larger and larger and tends to infinity. We observe
that the homogenization in physics is not equivalent to the homogenization in
mathematics up to some simple rescaling. With some direct error estimates, we
explain in what means we can accept the homogenized problem as the limitation
of the original real physical problems. As a byproduct, we present some results
on the mathematical homogenization of some problems with source term being only
weakly compacted in $H^{-1}$, while in standard homogenization theory, the
source term is assumed to be at least compacted in $H^{-1}$. A real example is
also given to show the validation of our observation and results.


title: Evidence for Multiple Chiral Doublet Bands in $^{133}$Ce

abstract:
  Two distinct sets of chiral-partner bands have been identified in the nucleus
$^{133}$Ce. They constitute a multiple chiral doublet (M$\chi$D), a phenomenon
predicted by relativistic mean field (RMF) calculations and observed
experimentally here for the first time. The properties of these chiral bands
are in good agreement with results of calculations based on a combination of
the constrained triaxial RMF theory and the particle-rotor model.


title:
Wave propagation in linear viscoelastic media with completely monotonic
  relaxation moduli

abstract:
  It is shown that viscoelastic wave dispersion and attenuation in a
viscoelastic medium with a completely monotonic relaxation modulus is
completely characterized by the phase speed and the dispersion-attenuation
spectral measure. The dispersion and attenuation functions are expressed in
terms of a single dispersion-attenuation spectral measure. An alternative
expression of the mutual dependence of the dispersion and attenuation
functions, known as the Kramers-Kronig dispersion relation, is also derived
from the theory. The minimum phase aspect of the filters involved in the
Green's function is another consequence of the theory. Explicit integral
expressions for the attenuation and dispersion functions are obtained for a few
analytical relaxation models.


title: Two-dimensional dispersive shock waves in dissipative optical media

abstract:
  We study generation of two-dimensional dispersive shock waves and oblique
dark solitons upon interaction of tilted plane waves with negative refractive
index defects embedded into defocusing material with linear gain and two-photon
absorption. Different evolution regimes are encountered including the formation
of well-localized disturbances for input tilts below critical one, and
generation of extended shock waves containing multiple intensity oscillations
in the "upstream" region and gradually vanishing oblique dark solitons in
"downstream" region for input tilts exceeding critical one. The generation of
stable dispersive shock waves is possible only below certain critical defect
strength.


title:
Simplicial vertices in graphs with no induced four-edge path or
  four-edge antipath, and the $H_6$-conjecture

abstract:
  Let $\mathcal{G}$ be the class of all graphs with no induced four-edge path
or four-edge antipath. Hayward and Nastos \cite{MS} conjectured that every
prime graph in $\mathcal{G}$ not isomorphic to the cycle of length five is
either a split graph or contains a certain useful arrangement of simplicial and
antisimplicial vertices. In this paper we give a counterexample to their
conjecture, and prove a slightly weaker version. Additionally, applying a
result of the first author and Seymour \cite{grow} we give a short proof of
Fouquet's result \cite{C5} on the structure of the subclass of bull-free graphs
contained in $\mathcal{G}$.


title: Excluding four-edge paths and their complements

abstract:
  We prove that a graph G contains no induced four-edge path and no induced
complement of a four-edge path if and only if G is obtained from five-cycles
and split graphs by repeatedly applying the following operations: substitution,
split graph unification, and split graph unification in the complement ("split
graph unification" is a new class-preserving operation that is introduced in
this paper).


title:
Generalization Guarantees for a Binary Classification Framework for
  Two-Stage Multiple Kernel Learning

abstract:
  We present generalization bounds for the TS-MKL framework for two stage
multiple kernel learning. We also present bounds for sparse kernel learning
formulations within the TS-MKL framework.


title: On the unbounded of a class of Fourier integral operator on $L^2(R^n)$

abstract:
  In this paper, we give an example of Fourier integral operator with a symbol
belongs to $\bigcap\limits_{0<\rho <1}S_{\rho,1}^{0}$ that cannot be extended
as a bounded operator on $L^{2}(\mathbb{R}^{n}).$


title: Generalizations of the classical Yang-Baxter equation and O-operators

abstract:
  Tensor solutions ($r$-matrices) of the classical Yang-Baxter equation (CYBE)
in a Lie algebra, obtained as the classical limit of the $R$-matrix solution of
the quantum Yang-Baxter equation (QYBE), is an important structure appearing in
different areas such as integrable systems, symplectic geometry, quantum groups
and quantum field theory. Further study of CYBE led to its interpretation as
certain operators, giving rise to the concept of O-operators. In [3], the
O-operators were in turn interpreted as tensor solutions of CYBE by enlarging
the Lie algebra. The purpose of this paper is to extend this study to a more
general class of operators that were recently introduced [4] in the study of
Lax pairs in integrable systems. Relationship between $\calo$-operators,
relative differential operators and Rota-Baxter operators are also discussed.


title: The shuffle relation of fractions from multiple zeta values

abstract:
  Partial fraction methods play an important role in the study of multiple zeta
values. One class of such fractions is related to the integral representations
of MZVs. We show that this class of fractions has a natural structure of
shuffle algebra. This finding conceptualizes the connections among the various
methods of stuffle, shuffle and partial fractions in the study of MZVs. This
approach also gives an explicit product formula of the fractions.


title: A Note on Fourier-Jacobi coefficients of Siegel modular forms

abstract:
  Let F be a Siegel cusp form of weight k and genus n>1 with Fourier-Jacobi
coefficients f_m. In this article, we estimate the growth of the Petersson
norms of f_m, where m runs over an arithmetic progression. This result sharpens
a recent result of Kohnen in [5].


title:
Revisiting conserved currents in F(R) theory of gravity via Noether
  symmetry

abstract:
  Noether symmetry of F(R) theory of gravity in vacuum and in the presence of
pressureless dust yields F(R) \propto R^{3/2} along with the conserved current
\frac{d}{dt}(a\sqrt R) in Robertson-Walker metric and nothing else. Still some
authors recently claimed to have obtained four conserved currents setting F(R)
\propto R^{3/2} a-priori, taking time translation along with a gauge term. We
show that the first one of these does not satisfy the field equations and the
second one is the Hamiltonian which is constrained to vanish in gravity and
thus a part and parcel of the field equations. We also show that the other two
conserved currents, which do not contain time translation are the same in
disguise and identical to the one mentioned above. Thus the claim is wrong.


title:
Second main theorem and uniqueness problem of meromorphic mappings with
  moving hypersurfaces

abstract:
  In this article, we establish some new second main theorems for meromorphic
mappings of $\mathbb C^m$ into $\mathbb P^n(\mathbb C)$ and moving
hypersurfaces with truncated counting functions. A uniqueness theorem for these
mappings sharing few moving hypersurfaces without counting multiplicity is also
given. This result is an improvement of the recent result of Dethloff - Tan
[3]. Moreover the meromorphic mappings in our result may be algebraically
degenerate. The last purpose of this article is to study uniqueness problem in
the case where the meromorphic mappings agree on small identical sets.


title:
Learning to Rank for Expert Search in Digital Libraries of Academic
  Publications

abstract:
  The task of expert finding has been getting increasing attention in
information retrieval literature. However, the current state-of-the-art is
still lacking in principled approaches for combining different sources of
evidence in an optimal way. This paper explores the usage of learning to rank
methods as a principled approach for combining multiple estimators of
expertise, derived from the textual contents, from the graph-structure with the
citation patterns for the community of experts, and from profile information
about the experts. Experiments made over a dataset of academic publications,
for the area of Computer Science, attest for the adequacy of the proposed
approaches.


title: Complex Magnetic Evolution and Magnetic Helicity in the Solar Atmosphere

abstract:
  Solar atmosphere is a single system unified by the presence of large-scale
magnetic fields. Topological changes in magnetic fields that occur in one place
may have consequences for coronal heating and eruptions for other, even remote
locations. Coronal magnetic fields also play role in transport of magnetic
helicity from Sun's subphotosphere/upper convection zone to the interplanetary
space. We discuss observational evidence pertinent to some aspects of the solar
corona being a global interconnected system, i.e., large-scale coronal heating
due to new flux emergence, eruption of chromospheric filament resulting from
changes in magnetic topology triggered by new flux emergence, sunspots rotation
as manifestation of transport of helicity through the photosphere, and
potential consequences of re-distribution of energy from solar luminosity to
the dynamo for solar cycle variations of solar irradiance.


title:
Off-shell Green functions at one-loop level in Maxwell-Chern-Simons
  quantum electrodynamics

abstract:
  We derive the off-shell photon propagator and fermion-photon vertex at
one-loop level in Maxwell-Chern-Simons quantum electrodynamics in arbitrary
covariant gauge, using four-component spinors with parity-even and parity-odd
mass terms for both fermions and photons. We present our results using a basis
of two, three and four point integrals, some of them not known previously in
the literature. These integrals are evaluated in arbitrary space-time
dimensions so that we reproduce results derived earlier under certain limits.


title:
Asymmetric pairing of realistic mass quarks and color neutrality in the
  Polyakov--Nambu--Jona-Lasinio model of QCD

abstract:
  We investigate the effects of realistic quark masses and local color
neutrality on quark pairing in the three-flavor Polyakov--Nambu--Jona-Lasinio
model. While prior studies have indicated the presence of light flavor quark
(2SC) or symmetric color-flavor-locked (CFL) pairing at low temperatures, we
find that in the absence of a local color neutrality constraint the inclusion
of the Polyakov loop gives rise to phases in which all quark colors and flavors
pair, but with unequal magnitudes. We study this asymmetric color-flavor-locked
(ACFL) phase, which can exist even for equal mass quarks, identifying its
location in the phase diagram, the order of the associated phase transitions,
and its symmetry breaking pattern, which proves to be the intersection of the
symmetry groups of the 2SC and CFL phases. We also investigate the effects of
the strange quark mass on this new phase and the QCD phase diagram generally.
Finally, we analyze the effect of a local color neutrality constraint on these
phases of asymmetric pairing. We observe that for massless quarks the
neutrality constraint renders the 2SC phase energetically unfavorable,
eliminating it at low temperatures, and giving rise to the previously proposed
low temperature critical point, with associated continuity between the hadronic
and ACFL phases. For realistic strange quark masses, however, the neutrality
constraint shrinks the 2SC region of the phase diagram, but does not eliminate
it, at T=0.


title:
Bell tests with random measurements require very high detection
  efficiencies

abstract:
  The observation that violating Bell inequalities with high probability is
possible even when the local measurements are randomly chosen, as occurs when
local measurements cannot be suitably calibrated or the parties do not share a
common reference frame, has recently attracted much theoretical and
experimental efforts. Here we show that this observation is only valid when the
overall detection efficiency is very high ($\eta \geq 0.90$), otherwise, even
when using the highest detection efficiency of recent photonic Bell tests, the
probability of demonstrating nonlocality is negligible (e.g., it is smaller
than 0.02% for $\eta=0.785$). Our results show that detection efficiency is a
much more critical resource for real-world applications than it was previously
thought.


title: Arthur-Merlin Streaming Complexity

abstract:
  We study the power of Arthur-Merlin probabilistic proof systems in the data
stream model. We show a canonical $\mathcal{AM}$ streaming algorithm for a wide
class of data stream problems. The algorithm offers a tradeoff between the
length of the proof and the space complexity that is needed to verify it.
  As an application, we give an $\mathcal{AM}$ streaming algorithm for the
\emph{Distinct Elements} problem. Given a data stream of length $m$ over
alphabet of size $n$, the algorithm uses $\tilde O(s)$ space and a proof of
size $\tilde O(w)$, for every $s,w$ such that $s \cdot w \ge n$ (where $\tilde
O$ hides a $\polylog(m,n)$ factor). We also prove a lower bound, showing that
every $\mathcal{MA}$ streaming algorithm for the \emph{Distinct Elements}
problem that uses $s$ bits of space and a proof of size $w$, satisfies $s \cdot
w = \Omega(n)$.
  As a part of the proof of the lower bound for the \emph{Distinct Elements}
problem, we show a new lower bound of $\Omega(\sqrt n)$ on the $\mathcal{MA}$
communication complexity of the \emph{Gap Hamming Distance} problem, and prove
its tightness.


title:
Eighth-order Derivative-Free Family of Iterative Methods for Nonlinear
  Equations

abstract:
  In this note, we present an eighth-order derivative-free family of iterative
methods for nonlinear equations. The proposed family shows optimal eight-order
of convergence in the sense of the Kung and Traub conjecture \cite{5} and is
based on the Steffensen derivative approximation used in the Newton-method. As
a final step, having in mind computational purposes, a derivative-free
polynomial base interpolation is used in order to get optimal order of
convergence with only four functional evaluations. Numerical esperiments and
few issues are discussed at the end of this note.


title: Benchmarking some Portuguese S&T system research units: 2nd Edition

abstract:
  The increasing use of productivity and impact metrics for evaluation and
comparison, not only of individual researchers but also of institutions,
universities and even countries, has prompted the development of bibliometrics.
Currently, metrics are becoming widely accepted as an easy and balanced way to
assist the peer review and evaluation of scientists and/or research units,
provided they have adequate precision and recall.
  This paper presents a benchmarking study of a selected list of representative
Portuguese research units, based on a fairly complete set of parameters:
bibliometric parameters, number of competitive projects and number of PhDs
produced. The study aimed at collecting productivity and impact data from the
selected research units in comparable conditions i.e., using objective metrics
based on public information, retrievable on-line and/or from official sources
and thus verifiable and repeatable. The study has thus focused on the activity
of the 2003-06 period, where such data was available from the latest official
evaluation.
  The main advantage of our study was the application of automatic tools,
achieving relevant results at a reduced cost. Moreover, the results over the
selected units suggest that this kind of analyses will be very useful to
benchmark scientific productivity and impact, and assist peer review.


title: Bond and Site Percolation in Three Dimensions

abstract:
  We simulate the bond and site percolation models on a simple-cubic lattice
with linear sizes up to L=512, and estimate the percolation thresholds to be
$p_c ({\rm bond})=0.248\,811\,82(10)$ and $p_c ({\rm site})=0.311\,607\,7(2)$.
By performing extensive simulations at these estimated critical points, we then
estimate the critical exponents $1/\nu =1.141\,0(15)$,
$\beta/\nu=0.477\,05(15)$, the leading correction exponent $y_i =-1.2(2)$, and
the shortest-path exponent $d_{\rm min}=1.375\,6(3)$. Various universal
amplitudes are also obtained, including wrapping probabilities, ratios
associated with the cluster-size distribution, and the excess cluster number.
We observe that the leading finite-size corrections in certain wrapping
probabilities are governed by an exponent $\approx -2$, rather than $y_i
\approx -1.2$.


title: Set-Membership Constrained Conjugate Gradient Beamforming Algorithms

abstract:
  In this work a constrained adaptive filtering strategy based on conjugate
gradient (CG) and set-membership (SM) techniques is presented for adaptive
beamforming. A constraint on the magnitude of the array output is imposed to
derive an adaptive algorithm that performs data-selective updates when
calculating the beamformer's parameters. We consider a linearly constrained
minimum variance (LCMV) optimization problem with the bounded constraint based
on this strategy and propose a CG type algorithm for implementation. The
proposed algorithm has data-selective updates, a variable forgetting factor and
performs one iteration per update to reduce the computational complexity. The
updated parameters construct a space of feasible solutions that enforce the
constraints. We also introduce two time-varying bounding schemes to measure the
quality of the parameters that could be included in the parameter space. A
comprehensive complexity and performance analysis between the proposed and
existing algorithms are provided. Simulations are performed to show the
enhanced convergence and tracking performance of the proposed algorithm as
compared to existing techniques.


title:
Nonzero |U_e3| from Charged Lepton Corrections and the Atmospheric
  Neutrino Mixing Angle

abstract:
  After the successful determination of the reactor neutrino mixing angle
\theta_13 ~ 0.16 \neq 0, a new feature suggested by the current neutrino
oscillation data is a sizeable deviation of the atmospheric neutrino mixing
angle \theta_23 from \pi/4. Using the fact that the neutrino mixing matrix U =
U_e^\dagger U_\nu, where U_e and U_\nu result from the diagonalisation of the
charged lepton and neutrino mass matrices, and assuming that U_\nu has a i)
bimaximal (BM), ii) tri-bimaximal (TBM) form, or else iii) corresponds to the
conservation of the lepton charge L' = L_e - L_\mu - L_\tau (LC), we
investigate quantitatively what are the minimal forms of U_e, in terms of
angles and phases it contains, that can provide the requisite corrections to
U_\nu so that \theta_13, \theta_23 and the solar neutrino mixing angle
\theta_12 have values compatible with the current data. Two possible orderings
of the 12 and the 23 rotations in U_e, "standard" and "inverse", are
considered. The results we obtain depend strongly on the type of ordering. In
the case of "standard" ordering, in particular, the Dirac CP violation phase
\delta, present in U, is predicted to have a value in a narrow interval around
i) \delta ~ \pi in the BM (or LC) case, ii) \delta ~ 3\pi/2 or \pi/2 in the TBM
case, the CP conserving values \delta = 0, \pi, 2\pi being excluded in the TBM
case at more than 4\sigma. In the addendum we discuss the implications of the
latest 2013 data.


title:
Semiclassical quantization and spectral limits of h-pseudodifferential
  and Berezin-Toeplitz operators

abstract:
  We introduce a minimalistic notion of semiclassical quantization and use it
to prove that the convex hull of the semiclassical spectrum of a quantum system
given by a collection of commuting operators converges to the convex hull of
the spectrum of the associated classical system. This gives a quick alternative
solution to the isospectrality problem for quantum toric systems. If the
operators are uniformly bounded, the convergence is uniform. Analogous results
hold for non-commuting operators.


title:
Asymptotic normality and efficiency of the maximum likelihood estimator
  for the parameter of a ballistic random walk in a random environment

abstract:
  We consider a one dimensional ballistic random walk evolving in a parametric
independent and identically distributed random environment. We study the
asymptotic properties of the maximum likelihood estimator of the parameter
based on a single observation of the path till the time it reaches a distant
site. We prove an asymptotic normality result for this consistent estimator as
the distant site tends to infinity and establish that it achieves the
Cram\'er-Rao bound. We also explore in a simulation setting the numerical
behaviour of asymptotic confidence regions for the parameter value.


title: Ergodic Actions and Spectral Triples

abstract:
  In this article, we give a general construction of spectral triples from
certain Lie group actions on unital C*-algebras. If the group G is compact and
the action is ergodic, we actually obtain a real and finitely summable spectral
triple which satisfies the first order condition of Connes' axioms. This
provides a link between the "algebraic" existence of ergodic action and the
"analytic" finite summability property of the unbounded selfadjoint operator.
More generally, for compact G we carefully establish that our (symmetric)
unbounded operator is essentially selfadjoint. Our results are illustrated by a
host of examples - including noncommutative tori and quantum Heisenberg
manifolds.


title: Searching for Spurious Solar and Sky Lines in the Fermi-LAT Spectrum

abstract:
  We search for a unified instrumental explanation of the spectral features
seen near $E_\gamma=130$ GeV in photons collected by Fermi-LAT from the
galactic center and from the Earth's limb. We report for the first time a
similar feature in photons originating from the vicinity of the Sun, and
examine the instrumental characteristics of this Solar feature. To test an
instrumental hypothesis, we identify the range of photon incident angles where
most of the peak photons are observed in these three spectral features. An
examination of the spectrum of photons from the rest of the sky with this
characteristic angular range reveals a hint of a spectral feature near
$E_\gamma=130$ GeV. These results cast further doubt on the
dark-matter-annihilation interpretation of the galactic center peak.


title: The cohomology of Deligne-Lusztig varieties for the general linear group

abstract:
  We propose two inductive approaches for determining the cohomology of
Deligne-Lusztig varieties in the case of the general linear group


title: Ballistic Motion of a Tracer Particle Coupled to a Bose gas

abstract:
  We study the motion of a heavy tracer particle weakly coupled to a dense
interacting Bose gas exhibiting Bose-Einstein condensation. In the so-called
mean-field limit, the dynamics of this system approaches one determined by
nonlinear Hamiltonian evolution equations. We derive the effective dynamics of
the tracer particle, which is described by a non-linear integro-differential
equation with memory, and prove that if the initial speed of the tracer
particle is below the speed of sound in the Bose gas the motion of the particle
approaches an inertial motion at constant velocity at large times.


title: A Primer on Stochastic Differential Geometry for Signal Processing

abstract:
  This primer explains how continuous-time stochastic processes (precisely,
Brownian motion and other Ito diffusions) can be defined and studied on
manifolds. No knowledge is assumed of either differential geometry or
continuous-time processes. The arguably dry approach is avoided of first
introducing differential geometry and only then introducing stochastic
processes; both areas are motivated and developed jointly.


title:
Confinement induced orbital breathing, fusion, fission and re-ordering
  in semifilled shell atoms

abstract:
  Alternate contraction and drastic expansion, i.e., `breathing' of electronic
subshells, the effects of fusion of two subshells into one subshell and its
subsequent fission (splitting) into the original subshells, as well as multiple
alteration of the order of subshells in confined semifilled shell atoms with a
progressively narrowing confinement are theoretically discovered. The
confinement is represented by a repulsive penetrable spherical potential of an
inner radius $r_{0}$. The effects are exemplified by calculated data for
confined semifilled shell atoms from the second, third and fourth rows of
Mendeleev's table - Li, N, P and Cr atoms with semifilled ${2\rm s}^{1}$,
${2\rm p}^{3}$, ${3\rm p}^{3}$ and ${3\rm d}^{5}$ subshells, respectively - for
the completeness of the study. The underlying physics behind the discovered
effects is explained.


title:
FEAST as a Subspace Iteration Eigensolver Accelerated by Approximate
  Spectral Projection

abstract:
  The calculation of a segment of eigenvalues and their corresponding
eigenvectors of a Hermitian matrix or matrix pencil has many applications. A
new density-matrix-based algorithm has been proposed recently and a software
package FEAST has been developed. The density-matrix approach allows FEAST's
implementation to exploit a key strength of modern computer architectures,
namely, multiple levels of parallelism. Consequently, the software package has
been well received, especially in the electronic structure community.
Nevertheless, theoretical analysis of FEAST has lagged. For instance, the FEAST
algorithm has not been proven to converge. This paper offers a detailed
numerical analysis of FEAST. In particular, we show that the FEAST algorithm
can be understood as an accelerated subspace iteration algorithm in conjunction
with the Rayleigh-Ritz procedure. The novelty of FEAST lies in its accelerator
which is a rational matrix function that approximates the spectral projector
onto the eigenspace in question. Analysis of the numerical nature of this
approximate spectral projector and the resulting subspaces generated in the
FEAST algorithm establishes the algorithm's convergence. This paper shows that
FEAST is resilient against rounding errors and establishes properties that can
be leveraged to enhance the algorithm's robustness. Finally, we propose an
extension of FEAST to handle non-Hermitian problems and suggest some future
research directions.


title:
Spectroscopic evidence for polaronic behaviour of the strong spin-orbit
  insulator Sr$_3$Ir$_2$O$_7$

abstract:
  We investigate the bilayer Ruddlesden-Popper iridate Sr$_3$Ir$_2$O$_7$ by
temperature-dependent angle-resolved photoemission. We find a narrow-gap
correlated insulator, with spectral features indicative of a polaronic ground
state, strikingly similar to that observed previously for the parent compounds
of the cuprate superconductors. We additionally observe similar behaviour for
the single-layer cousin Sr$_2$IrO$_4$, indicating that strong electron-boson
coupling dominates the low-energy excitations of this exotic family of
materials, and providing a microscopic link between the insulating ground
states of the seemingly-disparate 3d cuprates and 5d iridates.


title:
Phase Resolved Observations of Temporal Soliton Pulse Propagation in
  Silicon Nanowires

abstract:
  An effort was conducted to study temporal soliton pulse propagation in
silicon nano-waveguides. These nonlinear phenomenas were studied both
numerically and experimentally with phase-resolved Frequency Resolved Optical
Gating. Soliton pulse broadening, as well as pulse splitting from two-photon
absorption, was observed experimentally, and the simulations matched all of the
experimental results. Further simulations with the validated model have
demonstrated that compression can be observed in centimeter-length waveguides.
This study has demonstrated the feasibility of self-sustaining soliton pulse
propagation at substantially shorter length scales than optical fibers, which
offers much potential applications with regards to all-optical data transfer
and computing.


title: Parallel D2-Clustering: Large-Scale Clustering of Discrete Distributions

abstract:
  The discrete distribution clustering algorithm, namely D2-clustering, has
demonstrated its usefulness in image classification and annotation where each
object is represented by a bag of weighed vectors. The high computational
complexity of the algorithm, however, limits its applications to large-scale
problems. We present a parallel D2-clustering algorithm with substantially
improved scalability. A hierarchical structure for parallel computing is
devised to achieve a balance between the individual-node computation and the
integration process of the algorithm. Additionally, it is shown that even with
a single CPU, the hierarchical structure results in significant speed-up.
Experiments on real-world large-scale image data, Youtube video data, and
protein sequence data demonstrate the efficiency and wide applicability of the
parallel D2-clustering algorithm. The loss in clustering accuracy is minor in
comparison with the original sequential algorithm.


title: Illuminating the Primeval Universe with Type IIn Supernovae

abstract:
  The detection of Pop III supernovae could directly probe the primordial IMF
for the first time, unveiling the properties of the first galaxies, early
chemical enrichment and reionization, and the seeds of supermassive black
holes. Growing evidence that some Pop III stars were less massive than 100
solar masses may complicate prospects for their detection, because even though
they would have been more plentiful they would have died as core-collapse
supernovae, with far less luminosity than pair-instability explosions. This
picture greatly improves if the SN shock collides with a dense circumstellar
shell ejected during a prior violent LBV type eruption. Such collisions can
turn even dim SNe into extremely bright ones whose luminosities can rival those
of pair-instability SNe. We present simulations of Pop III Type IIn SN light
curves and spectra performed with the Los Alamos RAGE and SPECTRUM codes.
Taking into account Lyman-alpha absorption in the early universe and
cosmological redshifting, we find that 40 solar mass Pop III Type IIn SNe will
be visible out to z ~ 20 with JWST and out to z ~ 7 with WFIRST. Thus, even low
mass Pop III SNe can be used to probe the primeval universe.


title: Skew Calabi-Yau Algebras and Homological Identities

abstract:
  A skew Calabi-Yau algebra is a generalization of a Calabi-Yau algebra which
allows for a non-trivial Nakayama automorphism. We prove three homological
identities about the Nakayama automorphism and give several applications. The
identities we prove show (i) how the Nakayama automorphism of a smash product
algebra A # H is related to the Nakayama automorphisms of a graded skew
Calabi-Yau algebra A and a finite-dimensional Hopf algebra H that acts on it;
(ii) how the Nakayama automorphism of a graded twist of A is related to the
Nakayama automorphism of A; and (iii) that Nakayama automorphism of a skew
Calabi-Yau algebra A has trivial homological determinant in case A is
noetherian, connected graded, and Koszul.


title:
Soliton Propagation with Cross Phase Modulation in Silicon Photonic
  Crystal Waveguides

abstract:
  An effort was conducted to numerically determine, using the Nonlinear
Schrodinger Split-Step Fourier method, if using cross phase modulation could
cause temporal soliton pulse propagation in a silicon slow-light photonic
crystal waveguide shorter than a millimeter. The simulations demonstrated that
due to the higher powers and shorter scales of photonic crystals, two-photon
absorption would cause an optical soliton pulse to be extremely dissipative.
The model demonstrated, however, that by utilizing cross-phase modulation, it
is possible to sustain a compressed soliton pulse within a silicon photonic
crystal waveguide subjected to two-photon absorption over longer relative
distances.


title: Correcting Camera Shake by Incremental Sparse Approximation

abstract:
  The problem of deblurring an image when the blur kernel is unknown remains
challenging after decades of work. Recently there has been rapid progress on
correcting irregular blur patterns caused by camera shake, but there is still
much room for improvement. We propose a new blind deconvolution method using
incremental sparse edge approximation to recover images blurred by camera
shake. We estimate the blur kernel first from only the strongest edges in the
image, then gradually refine this estimate by allowing for weaker and weaker
edges. Our method competes with the benchmark deblurring performance of the
state-of-the-art while being significantly faster and easier to generalize.


title:
Euler time discretization of Backward Doubly SDEs and Application to
  Semilinear SPDEs

abstract:
  This paper investigates a numerical probabilistic method for the solution of
some semilinear stochastic partial differential equations (SPDEs in short). The
numerical scheme is based on discrete time approximation for solutions of
systems of decoupled forward-backward doubly stochastic differential equations.
Under standard assumptions on the parameters, the convergence and the rate of
convergence of the numerical scheme is proven. The proof is based on a
generalization of the result on the path regularity of the backward equation.


title:
A generalization of variable elimination for separable inverse problems
  beyond least squares

abstract:
  In linear inverse problems, we have data derived from a noisy linear
transformation of some unknown parameters, and we wish to estimate these
unknowns from the data. Separable inverse problems are a powerful
generalization in which the transformation itself depends on additional unknown
parameters and we wish to determine both sets of parameters simultaneously.
When separable problems are solved by optimization, convergence can often be
accelerated by elimination of the linear variables, a strategy which appears
most prominently in the variable projection methods due to Golub, Pereyra, and
Kaufman. Existing variable elimination methods require an explicit formula for
the optimal value of the linear variables, so they cannot be used in problems
with Poisson likelihoods, bound constraints, or other important departures from
least squares.
  To address this limitation, we propose a generalization of variable
elimination in which standard optimization methods are modified to behave as
though a variable has been eliminated. We verify that this approach is a proper
generalization by using it to re-derive several existing variable elimination
techniques. We then extend the approach to bound-constrained and Poissonian
problems, showing in the process that many of the best features of variable
elimination methods can be duplicated in our framework. Tests on difficult
exponential sum fitting and blind deconvolution problems indicate that the
proposed approach can have significant speed and robustness advantages over
standard methods.


title:
Optimal stochastic control problem under model uncertainty with
  non-entropic penalty

abstract:
  In this paper, a stochastic control problem under model uncertainty with
general penalty term is studied. Two types of penalties are considered. The
first one is of type f-divergence penalty treated in the general framework of a
continuous filtration. The second one called consistent time penalty studied in
the context of a Brownian filtration. In the case of consistent time penalty,
we characterize the value process of our stochastic control problem as the
unique solution of a class of quadratic backward stochastic differential
equation with unbounded terminal condition.


title:
Additive Unit Representations in Endomorphism Rings and an Extension of
  a result of Dickson and Fuller

abstract:
  A module is called automorphism-invariant if it is invariant under any
automorphism of its injective hull. Dickson and Fuller have shown that if $R$
is a finite-dimensional algebra over a field $\mathbb F$ with more than two
elements then an indecomposable automorphism-invariant right $R$-module must be
quasi-injective. In this note, we extend and simplify the proof of this result
by showing that any automorphism-invariant module over an algebra over a field
with more than two elements is quasi-injective. Our proof is based on the study
of the additive unit structure of endomorphism rings.


title:
On the $O(\alpha_s^2)$ corrections to $b \to X_u e \bar \nu$ inclusive
  decays

abstract:
  We present $O(\alpha_s^2)$ QCD corrections to the fully-differential decay
rate of a $b$-quark into inclusive semileptonic charmless final states. Our
calculation provides genuine two-loop QCD corrections, beyond the
Brodsky-Lepage-Mackenzie (BLM) approximation, to any infra-red safe partonic
observable that can be probed in $b \to X_u e \bar \nu$ decays. Kinematic cuts
that closely match those used in experiments can be fully accounted for. To
illustrate these points, we compute the non-BLM corrections to moments of the
hadronic invariant mass and the hadronic energy with cuts on the lepton energy
and the hadronic invariant mass. Our results remove one of the sources of
theoretical uncertainty that affect the extraction of the CKM matrix element
$|V_{ub}|$ from charmless inclusive B-decays.


title:
Exact solutions to the three-dimensional Gross-Pitaevskii equation with
  modulated radial nonlinearity

abstract:
  We study the Bose-Einstein condensate trapped in a three-dimensional
spherically symmetrical potential. Exact solutions to the stationary
Gross-Pitaevskii equation are obtained for properly modulated radial
nonlinearity. The solutions contain vortices with different winding numbers and
exhibit the shell-soliton feature in the radial distributions.


title: Sparse Camera Network for Visual Surveillance -- A Comprehensive Survey

abstract:
  Technological advances in sensor manufacture, communication, and computing
are stimulating the development of new applications that are transforming
traditional vision systems into pervasive intelligent camera networks. The
analysis of visual cues in multi-camera networks enables a wide range of
applications, from smart home and office automation to large area surveillance
and traffic surveillance. While dense camera networks - in which most cameras
have large overlapping fields of view - are well studied, we are mainly
concerned with sparse camera networks. A sparse camera network undertakes large
area surveillance using as few cameras as possible, and most cameras have
non-overlapping fields of view with one another. The task is challenging due to
the lack of knowledge about the topological structure of the network,
variations in the appearance and motion of specific tracking targets in
different views, and the difficulties of understanding composite events in the
network. In this review paper, we present a comprehensive survey of recent
research results to address the problems of intra-camera tracking, topological
structure learning, target appearance modeling, and global activity
understanding in sparse camera networks. A number of current open research
issues are discussed.


title: Functional Dependence in Strategic Games

abstract:
  The paper studies properties of functional dependencies between strategies of
players in Nash equilibria of multi-player strategic games. The main focus is
on the properties of functional dependencies in the context of a fixed
dependency graph for pay-off functions. A logical system describing properties
of functional dependence for any given graph is proposed and is proven to be
complete.


title: Evolution of rotational velocities of A-type stars

abstract:
  It was found that the equatorial velocity of A-type stars undergoes an
acceleration in the first third of the main sequence (MS) stage, but the
velocity decreases as if the stars were not undergoing any redistribution of
angular momentum in the external layers in the last stage of the MS phase. Our
calculations show that the acceleration and the decrease of the equatorial
velocity can be reproduced by the evolution of the differential rotation
zero-age MS model with the angular momentum transport caused by hydrodynamic
instabilities during the MS stage. The acceleration results from the fact that
the angular momentum stored in the interiors of the stars is transported
outwards. In the last stage, the core and the radiative envelope are
uncoupling, and the rotation of the envelope is a quasi-solid rotation; the
uncoupling and the expansion of the envelope lead to that the decrease of the
equatorial velocity approximately follows the slope for the change in the
equatorial velocity of the model without any redistribution of angular
momentum. When the fractional age 0.3 $\lesssim\mathrm{t/t_{MS}}\lesssim$ 0.5,
the equatorial velocity remains almost constant for the stars whose central
density increases with age in the early stage of the MS phase, while the
velocity decreases with age for the stars whose central density decreases with
age in the early stage of the MS phase.


title:
Design of optimal sparse interconnection graphs for synchronization of
  oscillator networks

abstract:
  We study the optimal design of a conductance network as a means for
synchronizing a given set of oscillators. Synchronization is achieved when all
oscillator voltages reach consensus, and performance is quantified by the
mean-square deviation from the consensus value. We formulate optimization
problems that address the trade-off between synchronization performance and the
number and strength of oscillator couplings. We promote the sparsity of the
coupling network by penalizing the number of interconnection links. For
identical oscillators, we establish convexity of the optimization problem and
demonstrate that the design problem can be formulated as a semidefinite
program. Finally, for special classes of oscillator networks we derive explicit
analytical expressions for the optimal conductance values.


title:
Algorithms for leader selection in stochastically forced consensus
  networks

abstract:
  We are interested in assigning a pre-specified number of nodes as leaders in
order to minimize the mean-square deviation from consensus in stochastically
forced networks. This problem arises in several applications including control
of vehicular formations and localization in sensor networks. For networks with
leaders subject to noise, we show that the Boolean constraints (a node is
either a leader or it is not) are the only source of nonconvexity. By relaxing
these constraints to their convex hull we obtain a lower bound on the global
optimal value. We also use a simple but efficient greedy algorithm to identify
leaders and to compute an upper bound. For networks with leaders that perfectly
follow their desired trajectories, we identify an additional source of
nonconvexity in the form of a rank constraint. Removal of the rank constraint
and relaxation of the Boolean constraints yields a semidefinite program for
which we develop a customized algorithm well-suited for large networks. Several
examples ranging from regular lattices to random graphs are provided to
illustrate the effectiveness of the developed algorithms.


title: Macroscopic superpositions and black hole unitarity

abstract:
  We discuss the black hole information problem, including the recent claim
that unitarity requires a horizon firewall, emphasizing the role of decoherence
and macroscopic superpositions. We consider the formation and evaporation of a
large black hole as a quantum amplitude, and note that during intermediate
stages (e.g., after the Page time), the amplitude is a superposition of
macroscopically distinct (and decohered) spacetimes, with the black hole itself
in different positions on different branches. Small but semiclassical observers
(who are themselves part of the quantum amplitude) that fall into the hole on
one branch will miss it entirely on other branches and instead reach future
infinity. This observation can reconcile the subjective experience of an
infalling observer with unitarity. We also discuss implications for the nice
slice formulation of the information problem, and to complementarity.


title: Identifying Signatures of Selection in Genetic Time Series

abstract:
  Both genetic drift and natural selection cause the frequencies of alleles in
a population to vary over time. Discriminating between these two evolutionary
forces, based on a time series of samples from a population, remains an
outstanding problem with increasing relevance to modern data sets. Even in the
idealized situation when the sampled locus is independent of all other loci
this problem is difficult to solve, especially when the size of the population
from which the samples are drawn is unknown. A standard $\chi^2$-based
likelihood ratio test was previously proposed to address this problem. Here we
show that the $\chi^2$ test of selection substantially underestimates the
probability of Type I error, leading to more false positives than indicated by
its $P$-value, especially at stringent $P$-values. We introduce two methods to
correct this bias. The empirical likelihood ratio test (ELRT) rejects
neutrality when the likelihood ratio statistic falls in the tail of the
empirical distribution obtained under the most likely neutral population size.
The frequency increment test (FIT) rejects neutrality if the distribution of
normalized allele frequency increments exhibits a mean that deviates
significantly from zero. We characterize the statistical power of these two
tests for selection, and we apply them to three experimental data sets. We
demonstrate that both ELRT and FIT have power to detect selection in practical
parameter regimes, such as those encountered in microbial evolution
experiments. Our analysis applies to a single diallelic locus, assumed
independent of all other loci, which is most relevant to full-genome selection
scans in sexual organisms, and also to evolution experiments in asexual
organisms as long as clonal interference is weak. Different techniques will be
required to detect selection in time series of co-segregating linked loci.


title: Superconducting Resonance and paring symmetry in electron-doped cuprates

abstract:
  The magnetic excitations in the superconducting electron-doped cuprates are
studied in the framework of spin-density-wave description. The superconducting
resonance is a natural product of the superconductivity due to the opening of
d-wave gap. Its resonance energy exhibits well linear scaling with
superconducting gap as $E_{res}/2\Delta\sim 0.6$, quantitatively consisting
with the experimental discovery. This ratio is insensitive to the selected
parameters, manifesting its universality. Another lower-energy peak below
resonance energy is predicted when the hole pocket emerges due to suppression
of spin-density wave. We further verify that the ratio of linear scales is
intimately related to the pairing symmetry. Distinct ratio can be found with
respective pairing symmetry. In comparison with the inelastic neutron
scattering data, the monotonic d-wave superconductivity is the most likely
candidate in the electron-doped cuprates. Furthermore, we proposed a new method
to check the pairing symmetry by the inelastic neutron scattering measurements.


title: Calibrating the complexity of Delta 2 sets via their changes

abstract:
  The computational complexity of a Delta 2 set will be calibrated by the
amount of changes needed for any of its computable approximations. Firstly, we
study Martin-Loef random sets, where we quantify the changes of initial
segments. Secondly, we look at c.e. sets, where we quantify the overall amount
of changes by obedience to cost functions. Finally, we combine the two
settings. The discussions lead to three basic principles on how complexity and
changes relate.


title: Weak-Value Amplification of light deflection by a dark atomic ensemble

abstract:
  We study the coherent propagation of light whose dynamics is governed by the
effective Schr\"{o}dinger equation derived in a magneto-optically-manipulated
atomic ensemble with a four-level tripod configuration for electromagnetically
induced transparency (EIT). The small transverse deflection of an optical beam,
which is ultra-sensitive to the EIT effect, could be drastically amplified via
a weak measurement with an appropriate preselection and postselection of the
polarization state. The physical mechanism is explained as the effect of
wavepacket reshaping, which results in an enlarged group velocity in the
transverse direction.


title:
Aharonov-Bohm effect and geometric phases -- Exact and approximate
  topology

abstract:
  By analyzing an exactly solvable model in the second quantized formulation
which allows a unified treatment of adiabatic and non-adiabatic geometric
phases, it is shown that the topology of the adiabatic Berry's phase, which is
characterized by the singularity associated with possible level crossing, is
trivial in a precise sense. This topology of the geometric phase is quite
different from the topology of the Aharonov-Bohm effect, where the topology is
specified by the external local gauge field and it is exact for the slow as
well as for the fast motion of the electron.

categories: quant-ph cond-mat.str-el hep-th math-ph math.MP


title: Spectra of the subdivision-vertex and subdivision-edge coronae

abstract:
  The subdivision graph $\mathcal{S}(G)$ of a graph $G$ is the graph obtained
by inserting a new vertex into every edge of $G$. Let $G_1$ and $G_2$ be two
vertex disjoint graphs. The \emph{subdivision-vertex corona} of $G_1$ and
$G_2$, denoted by $G_1\odot G_2$, is the graph obtained from $\mathcal{S}(G_1)$
and $|V(G_1)|$ copies of $G_2$, all vertex-disjoint, by joining the $i$th
vertex of $V(G_1)$ to every vertex in the $i$th copy of $G_2$. The
\emph{subdivision-edge corona} of $G_1$ and $G_2$, denoted by $G_1\circleddash
G_2$, is the graph obtained from $\mathcal{S}(G_1)$ and $|I(G_1)|$ copies of
$G_2$, all vertex-disjoint, by joining the $i$th vertex of $I(G_1)$ to every
vertex in the $i$th copy of $G_2$, where $I(G_1)$ is the set of inserted
vertices of $\mathcal{S}(G_1)$. In this paper we determine the adjacency
spectra, the Laplacian spectra and the signless Laplacian spectra of $G_1\odot
G_2$ (respectively, $G_1\circleddash G_2$) in terms of the corresponding
spectra of $G_1$ and $G_2$. As applications, the results on the spectra of
$G_1\odot G_2$ (respectively, $G_1\circleddash G_2$) enable us to construct
infinitely many pairs of cospectral graphs. The adjacency spectra of $G_1\odot
G_2$ (respectively, $G_1\circleddash G_2$) help us to construct many infinite
families of integral graphs. By using the Laplacian spectra, we also obtain the
number of spanning trees and Kirchhoff index of $G_1\odot G_2$ and
$G_1\circleddash G_2$, respectively.


title:
On the rotational energy distributions of reactive, non-polar species in
  the interstellar medium

abstract:
  A basic model for the formation of non-equilibrium rotational energy
distributions is described for reactive, homo-polar diatomic molecules and ions
in the interstellar medium. Kinetic models were constructed to calculate the
rotational populations of C2+ under the conditions it would experience in the
diffuse interstellar medium. As the non-polar ion reacts with molecular
hydrogen, but not atomic hydrogen, the thermalization of a hot nascent
rotational population will be arrested by chemical reaction when the H2 density
begins to be significant. Populations that deviate strongly from the local
thermodynamic equilibrium are predicted for C2+ in environments where it may be
detectable. Consequences of this are discussed and a new optical spectrum is
calculated.


title: On the performance of 1-level LDPC lattices

abstract:
  The low-density parity-check (LDPC) lattices perform very well in high
dimensions under generalized min-sum iterative decoding algorithm. In this work
we focus on 1-level LDPC lattices. We show that these lattices are the same as
lattices constructed based on Construction A and low-density lattice-code
(LDLC) lattices. In spite of having slightly lower coding gain, 1-level regular
LDPC lattices have remarkable performances. The lower complexity nature of the
decoding algorithm for these type of lattices allows us to run it for higher
dimensions easily. Our simulation results show that a 1-level LDPC lattice of
size 10000 can work as close as 1.1 dB at normalized error probability (NEP) of
$10^{-5}$.This can also be reported as 0.6 dB at symbol error rate (SER) of
$10^{-5}$ with sum-product algorithm.


title: Is the Higgs a sign of extra dimensions?

abstract:
  We introduce a 4-dimensional cutoff in the scenario of gauge-Higgs
unification to control the ultraviolet behavior. A one-loop effective potential
for a Higgs field and the Higgs mass are obtained with the cutoff. We find an
{\it interrelation} between the 4-dimensional cutoff and the scale of extra
dimensions, which is concretized through the Higgs mass. Combining this
interrelation and the recently discovered Higgs boson at LHC, we obtain an
interesting constraint for the 4-dimensional cutoff and the extra dimensional
scale.


title:
Resistance functions for two unequal spheres in linear flow at low
  Reynolds number with the Navier slip boundary condition

abstract:
  Resistance functions for two spherical particles with the Navier slip
boundary condition in general linear flows, including rigid translation, rigid
rotation, and strain, at low Reynolds number are derived by the method of
reflections as well as twin multipole expansions. In the solutions, particle
radii and slip lengths can be chosen independently. In the course of
calculations, single-sphere problem with the slip boundary condition is solved
by Lamb's general solution and the expression of multipole expansions, and
Fax\'{e}n's laws of force, torque, and stresslet for slip particle are also
derived. The solutions of two-body problem are confirmed to recover the
existing results in the no-slip limit and for the case of equal scaled slip
lengths.


title:
Zero-point fluctuations in rotation: Perpetuum mobile of the fourth kind
  without energy transfer

abstract:
  We discuss a simple Casimir-type device for which the rotational energy
reaches its global minimum when the device rotates about a certain axis rather
than remains static. This unusual property is a direct consequence of the fact
that the moment of inertia of zero-point vacuum fluctuations is a negative
quantity (the rotational vacuum effect). Moreover, the device does not produce
any work despite the fact that its equilibrium ground state corresponds to a
permanent rotation. Counterintuitively, the device has no internally moving
mechanical parts while its very existence is consistent with the laws of
thermodynamics. We point out that such devices may possibly be constructed
using carbon nanotubes. We call this "zero-point-driven" device as the
perpetuum mobile of the fourth kind.


title: Modeling citation networks based on vigorousness and dormancy

abstract:
  In citation networks, the activity of papers usually decreases with age and
dormant papers may be discovered and become fashionable again. To model this
phenomenon, a competition mechanism is suggested which incorporates two
factors: vigorousness and dormancy. Based on this idea, a citation network
model is proposed, in which a node has two discrete stage: vigorous and
dormant. Vigorous nodes can be deactivated and dormant nodes may be activated
and become vigorous. The evolution of the network couples addition of new nodes
and state transitions of old ones. Both analytical calculation and numerical
simulation show that the degree distribution of nodes in generated networks
displays a good right-skewed behavior. Particularly, scale-free networks are
obtained as the deactivated vertex is target selected and exponential networks
are realized for the random-selected case. Moreover, the measurement of four
real-world citation networks achieves a good agreement with the stochastic
model.

categories: physics.soc-ph cond-mat.stat-mech cs.DL cs.SI


title:
A solution for the differences in the continuity of continuum among
  mathematicians

abstract:
  There are the longstanding differences in the continuity of continuum among
mathematicians. Starting from studies on a mathematical model of contact, we
construct a set that is in contact everywhere by using the original idea of
Dedekind's cut and weakening Order axioms to violate Order axiom 1. It is
proved that the existence of the set constructed can eliminate the differences
in the continuity.


title: CVA and FVA to Derivatives Trades Collateralized by Cash

abstract:
  In this article, we combine replication pricing with expectation pricing for
derivative trades that are partially collateralized by cash. The derivatives
are replicated by underlying assets and cash, using repurchasing agreement
(repo) and margining, which incur funding costs. We derive a partial
differential equation (PDE) for the derivatives price, obtain and decompose its
solution into the risk-free value of the derivative plus credit valuation
adjustment (CVA) and funding valuation adjustment (FVA). For most derivatives,
as we shall show, CVAs can be evaluated analytically or semi-analytically,
while FVAs, as well as the derivatives values, will have to be solved
recursively through numerical procedures due to their interdependence. In
numerical demonstrations, continuous and discrete margin revisions are
considered, respectively, for an equity call option and a vanilla interest-rate
swaps.


title: Energy conditions in $f(R,G)$ gravity

abstract:
  Modified gravity is one of the most favorable candidates for explaining the
current accelerating expansion of the Universe. In this regard, we study the
viability of an alternative gravitational theory, namely $f(R,G)$, by imposing
energy conditions. We consider two forms of $f(R,G)$, commonly discussed in the
literature, which account for the stability of cosmological solutions. We
construct the inequalities obtained by energy conditions and specifically apply
the weak energy condition using the recent estimated values of the Hubble,
deceleration, jerk and snap parameters to probe the viability of the
above-mentioned forms of $f(R, G)$.


title:
Einstein@Home Discovery of 24 Pulsars in the Parkes Multi-beam Pulsar
  Survey

abstract:
  We have conducted a new search for radio pulsars in compact binary systems in
the Parkes multi-beam pulsar survey (PMPS) data, employing novel methods to
remove the Doppler modulation from binary motion. This has yielded unparalleled
sensitivity to pulsars in compact binaries. The required computation time of
approximately 17000 CPU core years was provided by the distributed volunteer
computing project Einstein@Home, which has a sustained computing power of about
1 PFlop/s. We discovered 24 new pulsars in our search, of which 18 were
isolated pulsars, and six were members of binary systems. Despite the wide
filterbank channels and relatively slow sampling time of the PMPS data, we
found pulsars with very large ratios of dispersion measure (DM) to spin period.
Among those is PSR J1748-3009, the millisecond pulsar with the highest known DM
(approximately 420 pc/cc). We also discovered PSR J1840-0643, which is in a
binary system with an orbital period of 937 days, the fourth largest known. The
new pulsar J1750-2536 likely belongs to the rare class of intermediate-mass
binary pulsars. Three of the isolated pulsars show long-term nulling or
intermittency in their emission, further increasing this growing family. Our
discoveries demonstrate the value of distributed volunteer computing for
data-driven astronomy and the importance of applying new analysis methods to
extensively searched data.


title:
Role of the $N^*(2080)$ in $pp \to pK^+ \Lambda(1520)$ and $\pi^- p \to
  K^0 \Lambda(1520)$ reactions

abstract:
  We investigate the $\Lambda(1520)$ hadronic production in the $p p \to p K^+
\Lambda(1520)$ and $\pi^- p \to K^0 \Lambda(1520)$ reactions within the
effective Lagrangian method. For $\pi^- p \to K^0 \Lambda(1520)$ reaction, in
addition to the "background" contributions from $t-$channel $K^*$ exchange,
$u-$channel $\Sigma^+$ exchange, and $s-$channel nucleon pole terms, we also
consider the contribution from the nucleon resonance $N^*(2080)$ (spin-parity
$J^P = 3/2^-$), which has significant coupling to $K\Lambda(1520)$ channel. We
show that the inclusion of the nucleon resonance $N^*(2080)$ leads to a fairly
good description of the low energy experimental total cross section data of
$\pi^- p \to K^0 \Lambda(1520)$ reaction. From fitting to the experimental
data, we get the $N^*(2080)N\pi$ coupling constant $g_{N^*(2080)N \pi} = 0.14
\pm 0.04$. By using this value and with the assumption that the excitation of
$N^*(2080)$ is due to the $\pi^0$-meson exchanges, we calculate the total and
differential cross sections of $p p \to p K^+ \Lambda(1520)$ reaction. We also
demonstrate that the invariant mass distribution and the Dalitz Plot provide
direct information of the $\Lambda(1520)$ production, which can be tested by
future experiments.


title: Quantum-mechanical engine models and their efficiencies

abstract:
  Based on quantum thermodynamic processes, we make a quantum-mechanical (QM)
extension of the typical heat engine cycles, such as the Carnot, Brayton, Otto,
and Diesel cycles, etc. The temperature is not included in these QM engine
cycles, as lies in the fact that the concept of energy is well-defined in
quantum mechanics, temperature \emph{a priori} is not. These QM engine cycles
are implemented by an ideal or interacting system with an arbitrary number of
particles confined in an arbitrary power-law trap. As a result, a relation
between the quantum adiabatic exponent and trap exponent is found. The
efficiency of a given QM engine cycle is similar to that of its classical
counterpart, thereby identifying the universality of the efficiency.


title: Physics of Low-Dimensional Ultracold Bose Gases

abstract:
  In this work we investigate the unique properties of ultracold Bose gases in
one and two dimensions. In two dimensions, we present simulations of the
Berezinskii-Kosterlitz-Thouless (BKT) phase transition using the projected
Gross-Pitaevskii equation formalism. We confirm the presence of the BKT phase
by observing algebraic decay in the first-order correlation function, unbinding
of vortex pairs, and behaviour of the superfluid fraction. In one dimension we
use a transverse Gaussian ansatz and the Lagrangian approach to derive an
effective equation of motion for the one dimensional Bose gas at zero
temperature.


title:
On the mean values of some multiplicative functions on the short
  interval

abstract:
  In this paper we study the mean values of some multiplicative functions
connected with the divisor function on the short interval of summation. The
asymptocic values for such mean values are proved.


title: On the curvature of symmetric products of a compact Riemann surface

abstract:
  Let $X$ be a compact connected Riemann surface of genus at least two. The
main theorem of arxiv:1010.1488 says that for any positive integer $n \leq
2({\rm genus}(X)-1)$, the symmetric product $S^n(X)$ does not admit any
K\"ahler metric satisfying the condition that all the holomorphic bisectional
curvatures are nonnegative. Our aim here is to give a very simple and direct
proof of this result of B\"okstedt and Rom\~ao.


title:
A mean value formula of sub-p-Laplace parabolic equations on the
  Heisenberg group

abstract:
  We derive two equivalent definitions of the viscosity solutions to the
homogeneous sub-p- Laplace parabolic equations on the Heisenberg group, and
characterize the viscosity solutions in terms of an asymptotic mean value
formula. Moreover, we construct an example to show that these formulae do not
hold in non-asymptotic sense.


title: Near-infrared luminescence in bismuth-doped TlCl crystal

abstract:
  Experimental and theoretical studies of spectral properties of crystalline
TlCl:Bi are performed. Two broad near-infrared luminescence bands with a
lifetime about 0.25 ms are observed: a strong band near 1.18 mkm excited by
0.40, 0.45, 0.70 and 0.80 mkm radiation, and a weak band at > 1.5 mkm excited
by 0.40 and 0.45 mkm radiation. Computer modeling of Bi-related centers in TlCl
lattice suggests that Bi^+__V^-(Cl) center (Bi^+ in Tl site and a negatively
charged Cl vacancy in the nearest anion site) is most likely responsible for
the IR luminescence.


title: On The Extension of the Toeplitz Algebra by Isometries

abstract:
  We introduce the notion of \pi-extension of the semigroup \mathbb{Z}_+ and
study the extensions of the Toeplitz algebras by isometric operators. We show
that when the action of the Toeplitz algebra is irreducible all such extensions
generate the same algebra, i.e. there are no non-trivial extensions of the
Toeplitz algebra. Also we provide the examples of the non-trivial extensions of
the Toeplitz algebra in case its representation is reducible.


title: Phase-amplitude descriptions of neural oscillator models

abstract:
  Phase oscillators are a common starting point for the reduced description of
many single neuron models that exhibit a strongly attracting limit cycle. The
framework for analysing such models in response to weak perturbations is now
particularly well advanced, and has allowed for the development of a theory of
weakly connected neural networks. However, the strong-attraction assumption may
well not be the natural one for many neural oscillator models. For example, the
popular conductance based Morris-Lecar model is known to respond to periodic
pulsatile stimulation in a chaotic fashion that cannot be adequately described
with a phase reduction. In this paper, we generalise the phase description that
allows one to track the evolution of distance from the cycle as well as phase
on cycle. We use a classical technique from the theory of ordinary differential
equations that makes use of a moving coordinate system to analyse periodic
orbits. The subsequent phase-amplitude description is shown to be very well
suited to understanding the response of the oscillator to external stimuli
(which are not necessarily weak). We consider a number of examples of neural
oscillator models, ranging from planar through to high dimensional models, to
illustrate the effectiveness of this approach in providing an improvement over
the standard phase-reduction technique. As an explicit application of this
phase-amplitude framework, we consider in some detail the response of a generic
planar model where the strong-attraction assumption does not hold, and examine
the response of the system to periodic pulsatile forcing. In addition, we
explore how the presence of dynamical shear can lead to a chaotic response.


title:
Cation Dependence of the Electronic States in Molecular Triangular
  Lattice System {\beta}'-X[Pd(dmit)_2]_2: A First-principles study

abstract:
  The electronic structure of an isostructural series of molecular conductors,
{\beta}'-X[Pd(dmit)_2]_2 is systematically studied by a first-principles method
based on the density-functional theory. The calculated band structures are
fitted to the tight-binding model based on Pd(dmit)_2 dimers on the triangular
lattice. We find systematic variation in the anisotropy of the transfer
integrals along the three directions of the triangular lattice taking different
values. The transfer integral along the face-to-face stacking direction of
Pd(dmit)_2 dimers is always the largest. Around the quantum spin liquid, X =
EtMe_3Sb, the other two transfer integrals become comparable. We also report
sensible differences in the distribution of wavefunctions near the Fermi level
between the two dmit ligands of the Pd(dmit)_2 molecule.


title: Temperature gradient and Fourier's law in gradient-mass harmonic systems

abstract:
  Heat flow and thermal profile in a 1D harmonic lattice with
coordinate-dependent masses has been calculated in the thermodynamic limit. It
is shown in the particular example of a 1D harmonic lattice with linearly
increasing masses that in standard Langevin conditions of contact, a
temperature gradient can form, and Fourier's law can be obeyed.


title:
Complex-valued information entropy measure for networks with directed
  links (digraphs). Application to citations by community agents with opposite
  opinions

abstract:
  The notion of complex-valued information entropy measure is presented. It
applies in particular to directed networks (digraphs). The corresponding
statistical physics notions are outlined. The studied network, serving as a
case study, in view of illustrating the discussion, concerns citations by
agents belonging to two distinct communities which have markedly different
opinions: the Neocreationist and Intelligent Design Proponents, on one hand,
and the Darwinian Evolution Defenders, on the other hand. The whole, intra- and
inter-community adjacency matrices, resulting from quotations of published work
by the community agents, are elaborated and eigenvalues calculated. Since
eigenvalues can be complex numbers, the information entropy may become also
complex-valued. It is calculated for the illustrating case. The role of the
imaginary part finiteness is discussed in particular and given some physical
sense interpretation through local interaction range consideration. It is
concluded that such generalizations are not only interesting and necessary for
discussing directed networks, but also may give new insight into conceptual
ideas about directed or other networks. Notes on extending the above to Tsallis
entropy measure are found in an Appendix.

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


title:
Stochastic Control Representations for Penalized Backward Stochastic
  Differential Equations

abstract:
  This paper shows that penalized backward stochastic differential equation
(BSDE), which is often used to approximate and solve the corresponding
reflected BSDE, admits both optimal stopping representation and optimal control
representation. The new feature of the optimal stopping representation is that
the player is allowed to stop at exogenous Poisson arrival times. The
convergence rate of the penalized BSDE then follows from the optimal stopping
representation. The paper then applies to two classes of equations, namely
multidimensional reflected BSDE and reflected BSDE with a constraint on the
hedging part, and gives stochastic control representations for their
corresponding penalized equations.


title: Long-Range and Many-Body Effects in Coagulation Processes

abstract:
  We study the problem of diffusing particles which coalesce upon contact. With
the aid of a non-perturbative renormalization group, we first analyze the
dynamics emerging below the critical dimension two, where strong fluctuations
imply anomalously slow decay. Above two dimensions, the long-time, low-density
behavior is known to conform with the law of mass action. For this case, we
establish an exact mapping between the physics at the microscopic scale
(lattice structure, particle shape and size) and the macroscopic decay rate in
the law of mass action. In addition, we identify a term violating this
classical law. It originates in long-range and many-particle fluctuations and
is a simple, universal function of the macroscopic decay rate.


title:
Enhanced high-field transport critical current densities observed for
  the ex-situ PIT processed Ag/(Ba,K)Fe2As2 thin tapes

abstract:
  We found that the transport Jc of the ex-situ PIT processed (Ba,K)Fe2As2
(Ba-122) wire with single Ag sheath can be significantly enhanced by repeating
the combined process of rolling and heat treatment. The transport Jc (4.2 K and
10 T) of 4.4 x 103 A/cm2 (Ic =15.7 A) was obtained for a thin tape of 0.3 mm in
thickness, which is the highest value reported so far for the PIT processed 122
wires and tapes with a Ag sheath and processed by a conventional route. The
measurement by a hybrid magnet showed that Jc-H curve maintains very small
field dependence up to the strong magnetic field of 28 T as expected from the
previously reported high Hc2 value. The core of the thin tape shows dense grain
structure with less cracks and voids and indicates the development of c-axis
alignment, although it is still incomplete. The researches to elucidate the
origin of Jc enhancement and to have further improvement of transport Jc are
now ongoing. The process is simple using a Ag single sheath and, therefore,
more realistic technique for long length wire production.


title:
Multifractal analysis of the pore space of real and simulated
  sedimentary rocks

abstract:
  It is well known that sedimentary rocks having same porosity can have very
different pore size distribution. The pore distribution determines many
characteristics of the rock among which, its transport property is often the
most useful. Multifractal analysis is a powerful tool that is increasingly used
to characterize the pore space. In this study we have done multifractal
analysis of pore distribution on sedimentary rocks simulated using the Relaxed
Bidisperse Ballistic Model (RBBDM). The RBBDM can generate a $3-D$ structure of
sedimentary rocks of variable porosity by tuning the fraction $p$ of particles
of two different sizes. We have also done multifractal analysis on two samples
of real sedimentary rock to compare with the simulation studies. One sample, an
oolitic limestone is of high porosity (40%)while the other is a reefal
carbonate of low porosity around 7%. $2-D$ sections of X-ray micro-tomographs
of the real rocks were stacked sequentially to reconstruct the real rock
specimens. Both samples show a multifractal character, but we show that RBBDM
gives a very realistic representation of a typical high porosity sedimentary
rock.


title: Stacked triangular lattice: Percolation properties

abstract:
  The stacked triangular lattice has the shape of a triangular prism. In spite
of being considered frequently in solid state physics and materials science,
its percolation properties have received few attention. We investigate several
non-universal percolation properties on this lattice using Monte Carlo
simulation. We show that the percolation threshold is
$p_c^\text{bond}=0.186\;02\pm0.000\;02$ for bonds and
$p_c^\text{site}=0.262\;40\pm0.000\;05$ for sites. The number of clusters at
the threshold per site is $n_c^\text{bond}=0.284\;58\pm0.000\;05$ and
$n_c^\text{site}=0.039\;98\pm0.000\;05$. The stacked triangular lattice is a
convenient choice to study the RGB model [Sci. Rep. {\bf 2}, 751 (2012)]. We
present results on this model and its scaling behavior at the percolation
threshold.


title:
Constraining parameter space of the Little Higgs model by data of tera-Z
  factory and ILC

abstract:
  The Standard Model prediction on the forward-backward asymmetry for $b\bar b$
production ($A^b_{FB}$) is well consistent with the data of LEP I at the
Z-pole, but deviates from the data at $\sqrt s=89\; 93$ GeV which are slightly
away from the pole. This deviation implies that there still is room for new
physics. We calculate the $A^b_{FB}$ at vicinity of Z-pole in the Little Higgs
Model as well as other measurable parameters such as $R_b$ and $R_c$, by which
we may constrain the parameter space of the Little Higgs Model. This can be
tested in the newly proposed tera-Z factory. With the fitted parameters we
further make predictions on $A^b_{FB}$ and $A^t_{FB}$ for $t\bar t$ production
at the ILC energy.


title: Cramer-Rao bound in detection of reversals

abstract:
  We use the Cramer-Rao bound to show which short magnetic reversals can be
recovered successfully from a magnetic anomaly profile. Using a simple variant
of the Vine-Matthews model, we show, in particular, that errors in determining
the duration of a short subchron are much smaller than errors in localizing the
center of the subchron.


title: On the dynamic compressibility of sets

abstract:
  We define a new notion of compressibility of a set of numbers through the
dynamics of a polynomial function. We provide approaches to solve the problem
by reducing it to the multi-criteria traveling salesman problem through a
series of transformations. We then establish computational complexity results
by giving some NP-completeness proofs. We also discuss about a notion of
$\epsilon$ K-compressibility of a set, with regard to lossy compression and
deduce the necessary condition for the given set to be $\epsilon$
K-compressible. Finally, we conclude by providing a list of open problems
solutions to which could extend the applicability the our technique.


title: A multi-lane traffic simulation model via continuous cellular automata

abstract:
  Traffic models based on cellular automata have high computational efficiency
because of their simplicity in describing unrealistic vehicular behavior and
the versatility of cellular automata to be implemented on parallel processing.
On the other hand, the other microscopic traffic models such as car-following
models are computationally more expensive, but they have more realistic driver
behaviors and detailed vehicle characteristics. We propose a new class between
these two categories, defining a traffic model based on continuous cellular
automata where we combine the efficiency of cellular automata models with the
accuracy of the other microscopic models. More precisely, we introduce a
stochastic cellular automata traffic model in which the space is not
coarse-grain but continuous. The continuity also allows us to embed a
multi-agent fuzzy system proposed to handle uncertainties in decision making on
road traffic. Therefore, we simulate different driver behaviors and study the
effect of various compositions of vehicles within the traffic stream from the
macroscopic point of view. The experimental results show that our model is able
to reproduce the typical traffic flow phenomena showing a variety of effects
due to the heterogeneity of traffic.


title: Q-prime curvature on CR manifolds

abstract:
  Q-prime curvature, which was introduced by J. Case and P. Yang, is a local
invariant of pseudo-hermitian structure on CR manifolds that can be defined
only when the Q-curvature vanishes identically. It is considered as a secondary
invariant on CR manifolds and, in 3-dimensions, its integral agrees with the
Burns-Epstein invariant, a Chern-Simons type invariant in CR geometry. We give
an ambient metric construction of the Q-prime curvature and study its basic
properties. In particular, we show that, for the boundary of a strictly
pseudoconvex domain in a Stein manifold, the integral of the Q-prime curvature
is a global CR invariant, which generalizes the Burns-Epstein invariant to
higher dimensions.


title: Improved Bounds on RIP for Generalized Orthogonal Matching Pursuit

abstract:
  Generalized Orthogonal Matching Pursuit (gOMP) is a natural extension of OMP
algorithm where unlike OMP, it may select $N (\geq1)$ atoms in each iteration.
In this paper, we demonstrate that gOMP can successfully reconstruct a
$K$-sparse signal from a compressed measurement $ {\bf y}={\bf \Phi x}$ by
$K^{th}$ iteration if the sensing matrix ${\bf \Phi}$ satisfies restricted
isometry property (RIP) of order $NK$ where $\delta_{NK} < \frac
{\sqrt{N}}{\sqrt{K}+2\sqrt{N}}$. Our bound offers an improvement over the very
recent result shown in \cite{wang_2012b}. Moreover, we present another bound
for gOMP of order $NK+1$ with $\delta_{NK+1} < \frac
{\sqrt{N}}{\sqrt{K}+\sqrt{N}}$ which exactly relates to the near optimal bound
of $\delta_{K+1} < \frac {1}{\sqrt{K}+1}$ for OMP (N=1) as shown in
\cite{wang_2012a}.


title: Basic quantum Hamiltonian's relativistic corrections

abstract:
  After analyzing Dirac's equation, one can suggest that a well-known
quantum-mechanical momentum operator is associated with relativistic momentum,
rather than with non-relativistic one. Consideration of relativistic energy and
momentum expressions allows us to define the non-relativistic, relativistic and
pseudo-relativistic (present in Schr\"odinger equation) kinetic energy
operators. Consequences of kinetic energy operator's correction for spectra of
basic quantum Hamiltonians are investigated. In some cases this correction can
produce remarkable spectra modifications.


title:
Reducing Poisson noise and baseline drift in X-ray spectral images with
  bootstrap Poisson regression and robust nonparametric regression

abstract:
  X-ray spectral imaging provides quantitative imaging of trace elements in
biological sample with high sensitivity. We propose a novel algorithm to
promote the signal-to-noise ratio (SNR) of X-ray spectral images that have low
photon counts. Firstly, we estimate the image data area that belongs to the
homogeneous parts through confidence interval testing. Then, we apply the
Poisson regression through its maximum likelihood estimation on this area to
estimate the true photon counts from the Poisson noise corrupted data. Unlike
other denoising methods based on regression analysis, we use the bootstrap
resampling method to ensure the accuracy of regression estimation. Finally, we
use a robust local nonparametric regression method to estimate the baseline and
subsequently subtract it from the X-ray spectral data to further improve the
SNR of the data. Experiments on several real samples show that the proposed
method performs better than some state-of-the-art approaches to ensure accuracy
and precision for quantitative analysis of the different trace elements in
standard reference biological sample.


title:
Cosmological perturbations in warm-tachyon inflationary universe model
  with viscous pressure on the brane

abstract:
  We study warm-viscous inflationary universe model on the brane, in a tachyon
field theory. We obtain the general conditions which are required for this
model to be realizable. In longitudinal gauge, the primoradial perturbation
parameters are found in great details, using slow-roll and quasi-stable
approximations. The general expressions of the tensor-to-scalar ratio, scalar
spectral index and its running are found. We derive the characteristics of the
inflationary universe model by using an effective exponential potential in two
cases: 1- Dissipative parameter $\Gamma$ and bulk viscous parameter $\zeta$ are
constant parameters. 2- Dissipative parameter as a function of tachyon field
$\phi$ and bulk viscous parameter as a function of radiation-matter mixture
energy density $\rho$. The parameters of the model are restricted by recent
observational data from the seven-year Wilkinson microwave anisotropy probe
(WMAP7).


title:
Local Structure Matching Driven by Joint-Saliency-Structure Adaptive
  Kernel Regression

abstract:
  For nonrigid image registration, matching the particular structures (or the
outliers) that have missing correspondence and/or local large deformations, can
be more difficult than matching the common structures with small deformations
in the two images. Most existing works depend heavily on the outlier
segmentation to remove the outlier effect in the registration. Moreover, these
works do not handle simultaneously the missing correspondences and local large
deformations. In this paper, we defined the nonrigid image registration as a
local adaptive kernel regression which locally reconstruct the moving image's
dense deformation vectors from the sparse deformation vectors in the
multi-resolution block matching. The kernel function of the kernel regression
adapts its shape and orientation to the reference image's structure to gather
more deformation vector samples of the same structure for the iterative
regression computation, whereby the moving image's local deformations could be
compliant with the reference image's local structures. To estimate the local
deformations around the outliers, we use joint saliency map that highlights the
corresponding saliency structures (called Joint Saliency Structures, JSSs) in
the two images to guide the dense deformation reconstruction by emphasizing
those JSSs' sparse deformation vectors in the kernel regression. The
experimental results demonstrate that by using local JSS adaptive kernel
regression, the proposed method achieves almost the best performance in
alignment of all challenging image pairs with outlier structures compared with
other five state-of-the-art nonrigid registration algorithms.


title: Progenitors of Supernovae Type Ia

abstract:
  Despite the significance of Type Ia supernovae (SNeIa) in many fields in
astrophysics, SNeIa lack a theoretical explanation. The standard scenarios
involve thermonuclear explosions of carbon/oxygen white dwarfs approaching the
Chandrasekhar mass; either by accretion from a companion or by a merger of two
white dwarfs. We investigate the contribution from both channels to the SNIa
rate with the binary population synthesis (BPS) code SeBa in order to constrain
binary processes such as the mass retention efficiency of WD accretion and
common envelope evolution. We determine the theoretical rates and delay time
distribution of SNIa progenitors and in particular study how assumptions affect
the predicted rates.


title:
Quantum phase transition of cold atoms in the bilayer hexagonal optical
  lattices

abstract:
  We propose a scheme to investigate the quantum phase transition of cold atoms
in the bilayer hexagonal optical lattices. Using the quantum Monte Carlo
method, we calculate the ground state phase diagrams which contain an
antiferromagnet, a solid, a superfluid, a fully polarized state and a
supersolid. We find there is a supersolid emerging in a proper parameter space,
where the diagonal long range order coexists with off-diagonal long range
order. We show that the bilayer optical lattices can be realized by coupling
two monolayer optical lattices and give an experimental protocol to observe
those novel phenomena in the real experiments.


title: Confining the light wave by using non-Euclidean transformation optics

abstract:
  A new way to understand why some inhomogeneous dielectric medium can be used
for confining the light wave has been given by using non-Euclidean
transformation optics. We show that special inhomogeneous dielectric medium,
which corresponds to a dip in the reference space, can be used for focusing a
plane wave. If we set an absorber at the appropriate position of this medium,
we can highly confine the light on the subwavelength scale.


title:
Dielectric Anomaly in the Quasi-One-Dimensional Frustrated Spin-1/2
  System Rb$_{2}$(Cu$_{1-x}$M$_{x}$)$_{2}$Mo$_{3}$O$_{12}$ (M=Ni and Zn)

abstract:
  Dielectric and magnetic properties have been studied for poly-crystalline
samples of quasi-one-dimensional frustrated spin-1/2 system
Rb$_{2}$(Cu$_{1-x}$M$_{x}$)$_{2}$Mo$_{3}$O$_{12}$(M=Ni and Zn) which does not
exhibit a three-dimensional magnetic transition due to quantum spin fluctuation
and low dimensionality. A broad peak in the magnetic susceptibility -
temperature curves originated from a short range helical ordering at low
temperature is suppressed by the Ni and Zn substitution for Cu sites. The
capacitance is found to anomalously increase with decreasing T below ~50 K,
which is also suppressed by the impurity doping. The behavior of the anomalous
capacitance component is found to be strongly connected with that of the
magnetic susceptibility for Rb$_{2}$(Cu$_{1-x}$M$_{x}$)$_{2}$Mo$_{3}$O$_{12}$
which indicates that the low-temperature dielectric response is driven by the
magnetism.


title:
Spectral non-uniform temperature, non-local heat transfer, and the spin
  Seebeck effect

abstract:
  We present a theory of the spin Seebeck effect driven by subthermal non-local
phonon heat transfer and spectral non-uniform temperature distribution. The
theory explains the non-local behavior of the effect arising from the fact that
phonons that store the energy (thermal) and the phonons that transfer it
(subthermal) are located in different parts of the spectrum and have very
different kinetics. This gives rise to a spectral phonon distribution function
that deviates from local equilibrium along the substrate and is sensitive to
boundary conditions. The theory also predicts a non-magnon origin of the effect
in ferromagnetic metals in agreement with observations in recent experiments.
Equilibration of the heat flow out of the substrate to the Pt probe and
backwards leads to a measurable vertical spin-current produced by the spin
polarized electrons dragged by the local thermal phonons. We predict specific
sample length limits and other dependencies that can be probed experimentally,
and obtain the correct magnitude of the effect.


title: Settling accretion onto slowly rotating X-ray pulsars

abstract:
  Quasi-spherical subsonic accretion onto slowly rotating magnetized NS is
considered, when the accreting matter settles down subsonically onto the
rotating magnetosphere, forming an extended quasi-static shell. The shell
mediates the angular momentum transfer to/from the rotating NS magnetosphere by
large-scale convective motions, which lead to an almost iso-angular-momentum
rotation law inside the shell. The accretion rate through the shell is
determined by the ability of the plasma to enter the magnetosphere due to
Rayleigh-Taylor instability while taking cooling into account. The settling
regime of accretion is possible for moderate X-ray luminosities L <4 10^36
erg/s. At higher luminosities a free-fall gap above the NS magnetosphere
appears due to rapid Compton cooling, and accretion becomes highly
non-stationary. From observations of spin-up/spin-down rates of wind accreting
equilibrium XPSRs with known orbital periods (GX 301-2, Vela X-1), the main
dimensionless parameters of the model and be determined and the NS magnetic
field can be estimated. For equilibrium pulsars with independent measurements
of the magnetic field the velocity of the stellar wind can be estimated without
the use of complicated spectroscopic measurements. For non-equilibrium pulsars,
a maximum possible value of the spin-down rate of the accreting neutron star
exists. From observations of the spin-down rate and the X-ray luminosity in
such pulsars (e. g. GX 1+4, SXP 1062 and 4U 2206+54) a lower limit on the
neutron star magnetic field is obtained, which in all cases turns out to be
close to the standard 10^12-10^13 G value, in agreement with cyclotron line
measurements. The model explains both the spin-up/spin-down of the pulsar
frequency on large time-scales and the irregular short-term frequency
fluctuations, which may correlate or anti-correlate with the X-ray luminosity
fluctuations.


title: Many-body problem in Kaluza-Klein models with toroidal compactification

abstract:
  In this paper, we consider a system of gravitating bodies in Kaluza-Klein
models with toroidal compactification of extra dimensions. To simulate the
astrophysical objects (e.g., our Sun and pulsars) with energy density much
greater than pressure, we suppose that these bodies are pressureless in the
external/our space. At the same time, they may have nonzero parameters
\omega_{(\bar\alpha -3)} \, (\bar\alpha =4,\ldots,D) of the equations of state
in the extra dimensions. We construct the Lagrange function of this many-body
system for any value of \Sigma =\sum_{\bar\alpha} \omega_{(\bar\alpha -3)}.
Moreover, the gravitational tests (PPN parameters, perihelion and periastron
advances) require negligible deviation from the latent soliton value \Sigma
=-(D-3)/2. However, the presence of pressure/tension in the internal space
results necessarily in the smearing of the gravitating masses over the internal
space and in the absence of the KK modes. This looks very unnatural from the
point of view of quantum physics.