title: Fidelity Threshold of the Surface Code Beyond Single-Qubit Error Models

abstract:
  The surface code is one the most promising alternatives for implementing
fault-tolerant, large-scale quantum information processing. Its high threshold
for single-qubit errors under stochastic noise is one of its most attrative
features. We develop an exact formulation for the fidelity of the surface code
that allows us to probe much further on this promise of strong protection. This
formulation goes beyond the stochastic single-qubit error model approximation
and can take into account both correlated errors and inhomogeneities in the
coupling between physical qubits and the environment. For the case of a
bit-flipping environment, we map the complete evolution after one quantum error
correction cycle onto the problem of computing correlation functions of a
two-dimensional Ising model with boundary fields. Exact results for the
fidelity threshold of the surface code are then obtained for several relevant
types of noise. Analytical predictions for a representative case are confirmed
by Monte Carlo simulations.


title:
Network Synchronization with Nonlinear Dynamics and Switching
  Interactions

abstract:
  This paper considers the synchronization problem for networks of coupled
nonlinear dynamical systems under switching communication topologies. Two types
of nonlinear agent dynamics are considered. The first one is non-expansive
dynamics (stable dynamics with a convex Lyapunov function $\varphi(\cdot)$) and
the second one is dynamics that satisfies a global Lipschitz condition. For the
non-expansive case, we show that various forms of joint connectivity for
communication graphs are sufficient for networks to achieve global asymptotic
$\varphi$-synchronization. We also show that $\varphi$-synchronization leads to
state synchronization provided that certain additional conditions are
satisfied. For the globally Lipschitz case, unlike the non-expansive case,
joint connectivity alone is not sufficient for achieving synchronization. A
sufficient condition for reaching global exponential synchronization is
established in terms of the relationship between the global Lipschitz constant
and the network parameters. We also extend the results to leader-follower
networks.


title:
Bergman Kernels and algebraic structure of limit space for a sequence of
  almost K\"{a}hler-Ricci solitons

abstract:
  In this paper, we give a lower bound of Bergman kernels for a sequence of
almost K\"{a}hler-Einstein Fano manifolds, or more general, a sequence of Fano
manifolds with almost K\"{a}hler-Ricci solitons. This generalizes a result by
Donaldson-Sun, Tian for K\"{a}hler-Einstein manifolds sequence with positive
scalar curvature. As an application of our result, we prove that the
Gromov-Hausdorff limit of sequence is homomorphic to a log terminal $Q$-Fano
variety which admits a K\"{a}hler-Ricci soliton on its smooth part.


title: Pseudo-random Phase Precoded Spatial Modulation

abstract:
  Spatial modulation (SM) is a transmission scheme that uses multiple transmit
antennas but only one transmit RF chain. At each time instant, only one among
the transmit antennas will be active and the others remain silent. The index of
the active transmit antenna will also convey information bits in addition to
the information bits conveyed through modulation symbols (e.g.,QAM).
Pseudo-random phase precoding (PRPP) is a technique that can achieve high
diversity orders even in single antenna systems without the need for channel
state information at the transmitter (CSIT) and transmit power control (TPC).
In this paper, we exploit the advantages of both SM and PRPP simultaneously. We
propose a pseudo-random phase precoded SM (PRPP-SM) scheme, where both the
modulation bits and the antenna index bits are precoded by pseudo-random
phases. The proposed PRPP-SM system gives significant performance gains over SM
system without PRPP and PRPP system without SM. Since maximum likelihood (ML)
detection becomes exponentially complex in large dimensions, we propose low
complexity local search based detection (LSD) algorithm suited for PRPP-SM
systems with large precoder sizes. Our simulation results show that with 4
transmit antennas, 1 receive antenna, $5\times 20$ pseudo-random phase precoder
matrix and BPSK modulation, the performance of PRPP-SM using ML detection is
better than SM without PRPP with ML detection by about 9 dB at $10^{-2}$ BER.
This performance advantage gets even better for large precoding sizes.


title: Bifurcation locus and branches at infinity of a polynomial f : C2 -> c

abstract:
  We show that the number of bifurcation points at infinity of a polynomial
function f : C2 -> C is at most the number of branches at infinity of a generic
fiber of f and that this upper bound can be diminished by one in certain cases.


title: Accretion onto Planetary Mass Companions of Low-Mass Young Stars

abstract:
  Measurements of accretion rates onto planetary mass objects may distinguish
between different planet formation mechanisms, which predict different
accretion histories. In this Letter, we use \HST/WFC3 UVIS optical photometry
to measure accretion rates onto three accreting objects, GSC06214-00210 b, GQ
Lup b, and DH Tau b, that are at the planet/brown dwarf boundary and are
companions to solar mass stars. The excess optical emission in the excess
accretion continuum yields mass accretion rates of $10^{-9}$ to $10^{-11}$
\Msol/yr for these three objects. Their accretion rates are an order of
magnitude higher than expected from the correlation between mass and accretion
rates measured from the UV excess, which is applicable if these wide planetary
mass companions formed by protostellar core fragmentation. The high accretion
rates and large separation from the central star demonstrate the presence of
massive disks around these objects. Models for the formation and evolution of
wide planetary mass companions should account for their large accretion rates.
High ratios of H$\alpha$ luminosity over accretion luminosity for objects with
low accretion rates suggest that searches for H$\alpha$ emission may be an
efficient way to find accreting planets.


title:
Explanation for the Transverse Radiation Force Observed on a Vertically
  Hanging Fiber

abstract:
  As shown in the experiment of She {\it et al.} [Phys. Rev. Lett. {\bf 101},
243601 (2008)], a weak laser beam sent through a vertically hanging fiber
exerts a transverse force and produces a lateral displacement of the fiber's
lower end. The experiment is of obvious theoretical interest in connection with
the electromagnetic theory of media. Suggested explanations given for this
effect in the past include the famous Abraham-Minkowski issue concerning the
"correct" photon momentum in matter. In our opinion such an explanation can
hardly be right. Instead, we propose instead a very simple description of the
effect implying that the sideways deflection is caused by the radiation force
on the {\it obliquely cut} lower end face of the fiber. From a calculation
based upon geometrical optics, we find quite good agreement with the
observations. We present also, as an alternative approach, a calculation
involving wave optics instead of geometrical optics, and find comparable
results.


title: Theoretical rates of pulsation period change in the Galactic Cepheids

abstract:
  Theoretical estimates of the rates of radial pulsation period change in
Galactic Cepheids with initial masses 5.5M_\odot <= Mzams <= 13M_\odot,
chemical composition X=0.7, Z=0.02 and periods 1.5 day <= P <= 100 day are
obtained from consistent stellar evolution and nonlinear stellar pulsation
computations. Pulsational instability was investigated for three crossings of
the instability strip by the evolutionary track in the HR diagram. The first
crossing occurs at the post-main sequence helium core gravitational contraction
stage which proceeds in the Kelvin--Helmholtz timescale whereas the second and
the third crossings take place at the evolutionary stage of thermonuclear core
helium burning. During each crossing of the instability strip the period of
radial pulsations is a quadratic function of the stellar evolution time.
Theoretical rates of the pulsation period change agree with observations but
the scatter of observational estimates of dP/dt noticeably exceeds the width of
the band (\delta\log |dP/dt| <= 0.6) confining evolutionary tracks in the
period - period change rate diagram. One of the causes of the large scatter
with very high values of dP/dt in Cepheids with increasing periods might be the
stars that cross the instability strip for the first time. Their fraction
ranges from 2% for Mzams=5.5M_\odot to 9% for Mzams=13M_\odot. Variable stars
\alpha UMi and IX Cas seem to belong to such objects.


title: Implicit Large Eddy Simulation of Cavitation in Micro Channel Flows

abstract:
  We present a numerical method for Large Eddy Simulations (LES) of
compressible two-phase flows. The method is validated for the flow in a micro
channel with a step-like restriction. This setup is representative for typical
cavitating multi-phase flows in fuel injectors and follows an experimental
study of Iben et al., 2010. While a diesel-like test fuel was used in the
experiment, we solve the compressible Navier-Stokes equations with a barotropic
equation of state for water and vapor and a simple phase-change model based on
equilibrium assumptions. Our LES resolve all wave dynamics in the compressible
fluid and the turbulence production in shear layers.


title:
Noncommutative Grassmannian of codimension two has coherent coordinate
  ring

abstract:
  A noncommutative Grassmannian NGr(m, n) is introduced by Efimov, Luntz, and
Orlov in `Deformation theory of objects in homotopy and derived categories III:
Abelian categories' as a noncommutative algebra associated to an exceptional
collection of n-m+1 coherent sheaves on P^n. It is a graded Calabi--Yau
Z-algebra of dimension n-m+1. We show that this algebra is coherent provided
that the codimension d = n-m of the Grassmannian is two. According to op. cit.,
this gives a t-structure on the derived category of the coherent sheaves on the
noncommutative Grassmannian. The proof is quite different from the recent
proofs of the coherence of some graded 3-dimensional Calabi--Yau algebras and
is based on properties of a PBW-basis of the algebra.


title:
Spatial Confinement Causes Lifetime Enhancement and Expansion of Vortex
  Rings with Positive Filament Tension

abstract:
  We study the impact of spatial confinement on the dynamics of
three-dimensional excitation vortices with circular filaments. In a chemically
active medium we observe a decreased contraction of such scroll rings and even
expanding ones, despite of their positive filament tension. We propose a
kinematical model which takes into account the interaction of the scroll ring
with a confining Neumann boundary. The model reproduces all experimentally
observed regimes of ring evolution, and correctly predicts the results obtained
by numerical simulations of the underlying reaction-diffusion equations.


title:
A class of compact entities in three component Bose - Einstein
  condensates

abstract:
  We introduce a new class of soliton-like entities in spinor three component
BECs. These entities generalize well known solitons. For special values of
coupling constants, the system considered is Completely Integrable and supports
$N$ soliton solutions. The one-soliton solutions can be generalized to systems
with different values of coupling constants. However, they no longer interact
elastically. When two so generalized solitons collide, a spin component
oscillation is observed in both emerging entities. We propose to call these
newly found entities oscillatons. They propagate without dispersion and retain
their character after collisions. We derived an exact mathematical model for
oscillatons and showed that the well known one soliton solutions are a
particular case.


title: Unstable Graphs: A Fresh Outlook via TF-Automorphisms

abstract:
  In this paper, we first establish the very close link between stability of
graphs, a concept first introduced in \cite{Scapsalvi1} and studied most
notably by Surowski \cite{Surowski1}, \cite{Surowski2} and Wilson
\cite{Wilson01} and two-fold automorphisms. The concept of two-fold
isomorphisms, as far as we know, first appeared in literature in the form of
isotopies of digraphs \cite{zelinka4}, \cite{zelinka1}, \cite{zelinka2},
\cite{zelinka3} and later studied formally in \cite{lms1}, \cite{lms2} with a
greater emphasis on undirected graphs. We then turn our attention to the
stability of graphs which have every edge on a triangle, but with the fresh
outlook provided by TF-automorphisms. Amongst such graphs are strongly regular
graphs with certain parameters. The advantages of this fresh outlook are
highlighted when we ultimately present a method of constructing and generating
unstable graphs with large diameter having every edge lying on a triangle. This
was a rather surprising outcome.


title: Monoids of modules and arithmetic of direct-sum decompositions

abstract:
  Let $R$ be a (possibly noncommutative) ring and let $\mathcal C$ be a class
of finitely generated (right) $R$-modules which is closed under finite direct
sums, direct summands, and isomorphisms. Then the set $\mathcal V (\mathcal C)$
of isomorphism classes of modules is a commutative semigroup with operation
induced by the direct sum. This semigroup encodes all possible information
about direct sum decompositions of modules in $\mathcal C$. If the endomorphism
ring of each module in $\mathcal C$ is semilocal, then $\mathcal V (\mathcal
C)$ is a Krull monoid. Although this fact was observed nearly a decade ago, the
focus of study thus far has been on ring- and module-theoretic conditions
enforcing that $\mathcal V(\mathcal C)$ is Krull. If $\mathcal V(\mathcal C)$
is Krull, its arithmetic depends only on the class group of $\mathcal
V(\mathcal C)$ and the set of classes containing prime divisors. In this paper
we provide the first systematic treatment to study the direct-sum
decompositions of modules using methods from Factorization Theory of Krull
monoids. We do this when $\mathcal C$ is the class of finitely generated
torsion-free modules over certain one- and two-dimensional commutative
Noetherian local rings.


title:
Deterministic formation of interface states in some two-dimensional
  photonic crystals with conical dispersions

abstract:
  There is no assurance that interface states can be found at the boundary
separating two materials. As a strong perturbation typically favors wave
localization, it is natural to expect that an interface state should form more
easily in the boundary that represents a strong perturbation. Here, we show on
the contrary that in some two dimensional photonic crystals (PCs) with a square
lattice possessing Dirac-like cone at k=0, a small perturbation guarantees the
existence of interface states. More specifically, we find that single-mode
localized states exist in a deterministic manner at an interface formed by two
PCs each with system parameters slightly perturbed from the conical dispersion
condition. The conical dispersion guarantees the existence of gaps in the
projected band structure which allows interface states to form and the assured
existence of interface states stems from the geometric phases of the bulk
bands.


title:
The Affine Structure of Gravitational Theories: Symplectic Groups and
  Geometry

abstract:
  We give a geometrical description of gravitational theories from the
viewpoint of symmetries and affine structure. We show how gravity, considered
as a gauge theory, can be consistently achieved by the nonlinear realization of
the conformal-affine group in an indirect manner: due the partial isomorphism
between $CA\left( 3,1\right) $ and the centrally extended $Sp\left( 8\right) $,
we perform a nonlinear realization of the centrally extended (CE)$Sp\left(
8\right) $ in its semi-simple version. In particular, starting from the bundle
structure of gravity, we derive the conformal-affine Lie algebra and then, by
the non-linear realization, we define the coset field transformations, the
Cartan forms and the inverse Higgs constraints. Finally we discuss the
geometrical Lagrangians where all the information on matter fields and their
interactions can be contained.


title:
Singular Behavior of Electric Field of High Contrast Concentrated
  Composites

abstract:
  A heterogeneous medium of constituents with vastly different mechanical
properties, whose inhomogeneities are in close proximity to each other, is
considered. The gradient of the solution to the corresponding problem exhibits
singular behavior (blow up) with respect to the distance between
inhomogeneities. This paper introduces a concise procedure for capturing the
leading term of gradient's asymptotics precisely. This procedure is based on a
thorough study of the system's energy. The developed methodology allows for
straightforward generalization to heterogeneous media with a nonlinear
constitutive description.


title: A 3D Babcock-Leighton Solar Dynamo Model

abstract:
  We present a 3D kinematic solar dynamo model in which poloidal field is
generated by the emergence and dispersal of tilted sunspot pairs (more
generally Bipolar Magnetic Regions, or BMRs). The axisymmetric component of
this model functions similarly to previous 2D Babcock-Leighton (BL) dynamo
models that employ a double-ring prescription for poloidal field generation but
we generalize this prescription into a 3D flux emergence algorithm that places
BMRs on the surface in response to the dynamo-generated toroidal field. In this
way, the model can be regarded as a unification of BL dynamo models (2D in
radius/latitude) and surface flux transport models (2D in latitude/longitude)
into a more self-consistent framework that captures the full 3D structure of
the evolving magnetic field. The model reproduces some basic features of the
solar cycle including an 11-yr periodicity, equatorward migration of toroidal
flux in the deep convection zone, and poleward propagation of poloidal flux at
the surface. The poleward-propagating surface flux originates as trailing flux
in BMRs, migrates poleward in multiple non-axisymmetric streams (made
axisymmetric by differential rotation and turbulent diffusion), and eventually
reverses the polar field, thus sustaining the dynamo. In this letter we briefly
describe the model, initial results, and future plans.


title: Asymptotic density of rational sets in free abelian groups

abstract:
  In this paper we study asymptotic density of rational sets in free abelian
group $\mathbb{Z}^n$ of rank $n$. We show that any rational set $R$ in
$\mathbb{Z}^n$ has asymptotic density. If $R$ is given by its semi-simple
decomposition we show how to compute its asymptotic density.


title: Lunar eclipse induces disturbance in the lunar exosphere

abstract:
  Given the renewed scientific interest in lunar exploration missions, complete
understanding of lunar near surface environment and its exosphere under
different conditions is of paramount importance. Lunar exosphere has been
extensively studied by ground based observations [18,19,20,21,22,23] and
hypothesized by different models[1,2,3,4,5,6,7,8,9,10,11,12,13]. In present
work, we have discussed overlooked possible sources behind changes in the lunar
exosphere when the Moon passes through the penumbra and umbra of the Earth
during a lunar eclipse. The dusty turbulent environment due to planetary shadow
is not only confined to lunar studies and exploration, but it can also be
extended to all terrestrial airless bodies in the universe with a dusty surface
e.g. some planets, planetary satellites, asteroids etc.


title:
On the complete indeterminacy and the chaoticity of generalized operator
  of Heun in Bargmann space

abstract:
  In Communications in Mathematical Physics, no. 199, (1998), we have
considered the Heun operator $\displaystyle{ H = a^* (a + a^*)a}$ acting on
Bargmann space where $a$ and $a^{*}$ are the standard Bose annihilation and
creation operators satisfying the commutation relation $[a, a^{*}] = I$.
  We have used the boundary conditions at infinity to give a description of all
maximal dissipative extensions in Bargmann space of the minimal Heun's operator
$H$. The characteristic functions of the dissipative extensions have be
computed and some completeness theorems have be obtained for the system of
generalized eigenvectors of this operator.
  In this paper we study the deficiency numbers of the generalized Heun's
operator
  $\displaystyle{ H^{p,m} = a^{*^{p}} (a^{m} + a^{*^{m}})a^{p}; (p, m=1, 2,
.....)}$ acting on Bargmann space. In particular, here we find some conditions
on the parameters $p$ and $m$ for that $\displaystyle{ H^{p,m}}$ to be
completely indeterminate. It follows from these conditions that $\displaystyle{
H^{p,m}}$ is entire of the type minimal. And we show that
$\displaystyle{H^{p,m}}$ and $\displaystyle{ H^{p,m}+ H^{*^{p,m}}}$ (where
$H^{*^{p,m}}$ is the adjoint of the $H^{p,m}$) are connected at the chaotic
operators. We will give a description of all maximal dissipative extensions and
all selfadjoint extensions of the minimal generalized Heun's operator $H^{p,m}$
acting on Bargmann space in separate paper.


title:
Sensitivity of Tunneling-Rotational Transitions in Ethylene Glycol to
  Variation of Electron-to-Proton Mass Ratio

abstract:
  Ethylene glycol in its ground conformation has tunneling transition with the
frequency about 7 GHz. This leads to a rather complicated tunneling-rotational
spectrum. Because tunneling and rotational energies have different dependence
on the electron-to-proton mass ratio $\mu$, this spectrum is highly sensitive
to the possible $\mu$ variation. We used simple 14 parameter effective
Hamiltonian to calculate dimensionless sensitivity coefficients $Q_\mu$ of the
tunneling-rotational transitions and found that they lie in the range from
$-17$ to $+18$. Ethylene glycol has been detected in the interstellar medium.
All this makes it one of the most sensitive probes of $\mu$ variation at the
large space and time scales.


title: Planck stars

abstract:
  A star that collapses gravitationally can reach a further stage of its life,
where quantum-gravitational pressure counteracts weight. The duration of this
stage is very short in the star proper time, yielding a bounce, but extremely
long seen from the outside, because of the huge gravitational time dilation.
Since the onset of quantum-gravitational effects is governed by energy density
---not by size--- the star can be much larger than planckian in this phase. The
object emerging at the end of the Hawking evaporation of a black hole can then
be larger than planckian by a factor $(m/m_{\scriptscriptstyle P})^n$, where
$m$ is the mass fallen into the hole, $m_{\scriptscriptstyle P}$ is the Planck
mass, and $n$ is positive. We consider arguments for $n=1/3$ and for $n=1$.
There is no causality violation or faster-than-light propagation. The existence
of these objects alleviates the black-hole information paradox. More
interestingly, these objects could have astrophysical and cosmological
interest: they produce a detectable signal, of quantum gravitational origin,
around the $10^{-14} cm$ wavelength.


title:
Effects of coordination and pressure on sound attenuation, boson peak
  and elasticity in amorphous solids

abstract:
  Connectedness and applied stress strongly affect elasticity in solids. In
various amorphous solids, mechanical stability can be lost either by reducing
connectedness or by increasing pressure. We present an effective medium theory
of elasticity that extends previous approaches by incorporating the effect of
compression, of amplitude $e$, allowing one to describe quantitative features
of sound propagation, transport, the boson peak, and elastic moduli near the
elastic instability occurring at a compression $e_c$. The theory disentangles
several frequencies characterizing the vibrational spectrum: the onset
frequency $\omega_0\sim \sqrt{e_c-e}$ where strongly-scattered modes appear in
the vibrational spectrum, the pressure-independent frequency $\omega_*$ where
the density of states displays a plateau, the boson peak frequency
$\omega_{BP}$, and the Ioffe-Regel frequency $\omega_{IR}$ where scattering
length and wavelength become equal. We predict that sound attenuation crosses
over from $\omega^4$ to $\omega^2$ behaviour at $\omega_0$. We predict that a
frequency-dependent length scale $l_s(\omega)$ and speed of sound $\nu(\omega)$
characterize vibrational modes, and could be extracted from scattering data.
One key result is the prediction of a flat diffusivity above $\omega_0$, in
agreement with previously unexplained observations. We find that the shear
modulus does not vanish at the elastic instability, but drops by a factor of 2.
We check our predictions in packings of soft particles and study the case of
covalent networks and silica. Overall, our approach unifies sound attenuation,
transport and length scales entering elasticity in a single framework where
disorder is not the main parameter controlling the boson peak, in agreement
with observations. This framework leads to a phase diagram where various
glasses can be placed, connecting microscopic structure to vibrational
properties.


title:
Generalized parton distributions from neutrino experiments: twist-three
  effects

abstract:
  We study the twist-3 corrections to the neutrino induced deeply virtual meson
production due to the chiral odd transversity Generalized Parton Distribution
(GPD). We found that in contrast to pion electroproduction, in neutrino-induced
processes these corrections are small. This occurs due to large contribution of
unpolarized GPDs $H,\, E$ to the twist-2 amplitude in neutrinoproduction. Our
results are important for analyses of the pion and kaon production in the
Minerva experiment at FERMILAB.


title: New quasi-exactly solvable class of generalized isotonic oscillators

abstract:
  We introduce a new family of quasi-exactly solvable generalized isotonic
oscillators which are based on the pseudo-Hermite exceptional orthogonal
polynomials. We obtain exact closed-form expressions for the energies and
wavefunctions as well as the allowed potential parameters for the first two
members of the family using the Bethe ansatz method. Numerical calculations of
the energies reveal that member potentials have multiple quasi-exactly solvable
eigenstates and the number of states for higher members are parameter
dependent.


title:
Search for supersymmetric baryons near production threshold in terms of
  the superflavor symmetry

abstract:
  The supersymmetry (SUSY) may be one of the most favorable extensions of the
standard model (SM), however, so far at LHC no evidence of the SUSY particles
were observed. An obvious question is whether they have already emerged, but
escaped from our detection, or do not exist at all. We propose that the future
ILC may provide sufficient energy to produce SUSY particles if they are not too
heavy in the low background environment. The superflavor symmetry associates
baryons with mesons as long as both of them containing a heavy constituent and
a light one. In this work, we estimate the production rate of SUSY baryons near
their production threshold in terms of the $B\bar B$ production data. Our
analysis indicates that if the SUSY baryons with masses below $\sqrt s/2$
($\sqrt s$ is the ILC energy) exist, they could be observed at future ILC.


title:
A Machine Learning Approach for the Identification of Bengali Noun-Noun
  Compound Multiword Expressions

abstract:
  This paper presents a machine learning approach for identification of Bengali
multiword expressions (MWE) which are bigram nominal compounds. Our proposed
approach has two steps: (1) candidate extraction using chunk information and
various heuristic rules and (2) training the machine learning algorithm called
Random Forest to classify the candidates into two groups: bigram nominal
compound MWE or not bigram nominal compound MWE. A variety of association
measures, syntactic and linguistic clues and a set of WordNet-based similarity
features have been used for our MWE identification task. The approach presented
in this paper can be used to identify bigram nominal compound MWE in Bengali
running text.


title:
Yet another derivation of special relativity transformations without the
  second postulate

abstract:
  The most general transformation connecting inertial frames is derived from
rather general and simple assumptions, without the postulate of constancy of
the speed of light in vacuo.


title: Blow-up for the two-component Camassa-Holm system

abstract:
  Following conservative solutions of the two-component Camassa-Holm system
$u_t-u_{txx}+3uu_x-2u_xu_{xx}-uu_{xxx}+\rho\rho_x=0$, $\rho_t+(u\rho)_x=0$
along characteristics, we determine if wave breaking occurs in the nearby
future or not, for initial data $u_0\in H^1(\mathbb R)$ and $\rho_0\in
L^2(\mathbb R)$.


title:
A matrix weighted $T1$ theorem for matrix kernelled Calderon Zygmund
  operators - I

abstract:
  In this series of two papers, we will prove a natural matrix weighted $T1$
theorem for matrix kernelled CZOs. In the current paper, we will prove matrix
weighted norm inequalities for matrix symbolled paraproducts via a general
matrix weighted Carleson embedding theorem. Along the way, we will also provide
a stopping time proof of the identification of $L^p(W)$ as a weighted
Triebel-Lizorkin space when $W$ is a matrix A${}_p$ weight.


title:
Keyword and Keyphrase Extraction Using Centrality Measures on
  Collocation Networks

abstract:
  Keyword and keyphrase extraction is an important problem in natural language
processing, with applications ranging from summarization to semantic search to
document clustering. Graph-based approaches to keyword and keyphrase extraction
avoid the problem of acquiring a large in-domain training corpus by applying
variants of PageRank algorithm on a network of words. Although graph-based
approaches are knowledge-lean and easily adoptable in online systems, it
remains largely open whether they can benefit from centrality measures other
than PageRank. In this paper, we experiment with an array of centrality
measures on word and noun phrase collocation networks, and analyze their
performance on four benchmark datasets. Not only are there centrality measures
that perform as well as or better than PageRank, but they are much simpler
(e.g., degree, strength, and neighborhood size). Furthermore, centrality-based
methods give results that are competitive with and, in some cases, better than
two strong unsupervised baselines.


title:
Relativistic cosmology number densities in void-Lemaitre-Tolman-Bondi
  models

abstract:
  The goal of this work is to compute the number density of far-IR selected
galaxies in the comoving frame and along the past lightcone of observationally
constrained LTB models and to compare those results with their standard model
counterparts.
  We derived integral number densities and differential number densities using
different cosmological distance definitions in the LTB models. Then, we
computed selection functions and consistency functions for the luminosity
functions in the combined fields of the Herschel/PACS evolutionary probe (PEP)
survey in both standard and void cosmologies, from which we derived the
observed values of the above-mentioned densities. We used the
Kolmogorov-Smirnov statistics to study both the evolution of the consistency
functions and its connection to the evolution of the comoving density of
sources. Finally, we fitted the power-law behaviour of the densities along the
observer's past lightcone.
  The analysis of the comoving number density shows that the increased
flexibility of the LTB models is not enough to fit the observed redshift
evolution of the number counts, if it is specialised to a recent best-fit giant
void parametrisation. The results for the power-law fits of the densities along
the observer's past lightcone show general agreement across both cosmological
models studied here around a slope of -2.5 $\pm$ 0.1 for the integral number
density on the luminosity-distance volumes. The differential number densities
show much bigger slope discrepancies.
  We conclude that the differential number densities on the observer's past
lightcone were still rendered dependent on the cosmological model by the flux
limits of the PEP survey. In addition, we show that an intrinsic evolution of
the sources must be assumed to fit the comoving number-density redshift
evolution in the giant void parametrisation for the LTB models used in this
work.


title: Deverbal semantics and the Montagovian generative lexicon

abstract:
  We propose a lexical account of action nominals, in particular of deverbal
nominalisations, whose meaning is related to the event expressed by their base
verb. The literature about nominalisations often assumes that the semantics of
the base verb completely defines the structure of action nominals. We argue
that the information in the base verb is not sufficient to completely determine
the semantics of action nominals. We exhibit some data from different
languages, especially from Romance language, which show that nominalisations
focus on some aspects of the verb semantics. The selected aspects, however,
seem to be idiosyncratic and do not automatically result from the internal
structure of the verb nor from its interaction with the morphological suffix.
We therefore propose a partially lexicalist approach view of deverbal nouns. It
is made precise and computable by using the Montagovian Generative Lexicon, a
type theoretical framework introduced by Bassac, Mery and Retor\'e in this
journal in 2010. This extension of Montague semantics with a richer type system
easily incorporates lexical phenomena like the semantics of action nominals in
particular deverbals, including their polysemy and (in)felicitous
copredications.


title:
Category theory, logic and formal linguistics: some connections, old and
  new

abstract:
  We seize the opportunity of the publication of selected papers from the
\emph{Logic, categories, semantics} workshop in the \emph{Journal of Applied
Logic} to survey some current trends in logic, namely intuitionistic and linear
type theories, that interweave categorical, geometrical and computational
considerations. We thereafter present how these rich logical frameworks can
model the way language conveys meaning.


title: Submixing and Shift-invariant Stochastic Games

abstract:
  We consider zero-sum stochastic games with perfect information and finitely
many states and actions. The payoff is computed by a function which associates
to each infinite sequence of states and actions a real number. We prove that if
the payoff function is both shift-invariant and submixing, then the game is
half-positional, i.e. the first player has an optimal strategy which is both
deterministic and stationary. This result relies on the existence of
epsilon-subgame-perfect strategies in shift-invariant games, a second
contribution of the paper. The techniques can be used to establish a third
result: for shift-invariant and submixing payoff functions, the existence of
finite-memory strategies for player 2 in one-player games implies the same
property for two-player games as well.


title: Adding modular predicates to first-order fragments

abstract:
  We investigate the decidability of the definability problem for fragments of
first order logic over finite words enriched with modular predicates. Our
approach aims toward the most generic statements that we could achieve, which
successfully covers the quantifier alternation hierarchy of first order logic
and some of its fragments. We obtain that deciding this problem for each level
of the alternation hierarchy of both first order logic and its two-variable
fragment when equipped with all regular numerical predicates is not harder than
deciding it for the corresponding level equipped with only the linear order and
the successor. For two-variable fragments we also treat the case of the
signature containing only the order and modular predicates.Relying on some
recent results, this proves the decidability for each level of the alternation
hierarchy of the two-variable first order fragmentwhile in the case of the
first order logic the question remains open for levels greater than two.The
main ingredients of the proofs are syntactic transformations of first order
formulas as well as the algebraic framework of finite categories.


title: Cusps and Cores in the presence of galactic bulges

abstract:
  In this paper, we study how the presence of bulge formation in galaxies
influence their inner density profile, by means of an extended version of the
Del Popolo (2009) semi-analytical model. As in Del Popolo (2009), the model
takes into account the effect of baryons adiabatic contraction, ordered and
random angular momentum, dynamical friction, and adds to the previous the
effect of gas cooling, star formation, supernova feedback, and reionization.
Our model shows that dwarf galaxies are bulgeless, in agreement with
observations showing that the large majority of them has no stellar bulges, and
are characterized by a flat profile well described by a Burkert profile. {We
then studied the effect of a bulge, added to the {cored} DM halo, on the
density profile}. In the case of a galaxy having a mass $10^{11} M_{\odot}$ the
inner density profile has a slope $\alpha \simeq 0.65$, for a bulge of $4.5
\times 10^{9} M_{\odot}$, while if bulge formation is not considered, the slope
would be $\alpha \simeq 0.55$. If the bulge is larger, $6.5 \times 10^{9}
M_{\odot}$ the slope is $\alpha \simeq 0.7$. In the case of a larger galaxy
with $10^{12} M_{\odot}$ the slope is $\alpha \simeq 0.85$, while in absence of
bulge it is $\alpha \simeq 0.75$. We finally study how the inner slope $\alpha$
changes with the bulge mass, and we find a correlation among the two
quantities. The result shows that bulge formation has an important role in
shaping the inner DM density profile in agreement with Inoue & Saitoh (2011)
result. The result implies that going from Sc to SO Hubble type the slope is
slightly steepening due to the bulge formation, and due to the fact that early
type galaxies have larger bulges.


title: Simple Error Bounds for Regularized Noisy Linear Inverse Problems

abstract:
  Consider estimating a structured signal $\mathbf{x}_0$ from linear,
underdetermined and noisy measurements
$\mathbf{y}=\mathbf{A}\mathbf{x}_0+\mathbf{z}$, via solving a variant of the
lasso algorithm: $\hat{\mathbf{x}}=\arg\min_\mathbf{x}\{
\|\mathbf{y}-\mathbf{A}\mathbf{x}\|_2+\lambda f(\mathbf{x})\}$. Here, $f$ is a
convex function aiming to promote the structure of $\mathbf{x}_0$, say
$\ell_1$-norm to promote sparsity or nuclear norm to promote low-rankness. We
assume that the entries of $\mathbf{A}$ are independent and normally
distributed and make no assumptions on the noise vector $\mathbf{z}$, other
than it being independent of $\mathbf{A}$. Under this generic setup, we derive
a general, non-asymptotic and rather tight upper bound on the $\ell_2$-norm of
the estimation error $\|\hat{\mathbf{x}}-\mathbf{x}_0\|_2$. Our bound is
geometric in nature and obeys a simple formula; the roles of $\lambda$, $f$ and
$\mathbf{x}_0$ are all captured by a single summary parameter
$\delta(\lambda\partial((f(\mathbf{x}_0)))$, termed the Gaussian squared
distance to the scaled subdifferential. We connect our result to the literature
and verify its validity through simulations.


title: Isomorphisms between Jacobson graphs

abstract:
  Let $R$ be a commutative ring with a non-zero identity and $\mathfrak{J}_R$
be its Jacobson graph. We show that if $R$ and $R'$ are finite commutative
rings, then $\mathfrak{J}_R\cong\mathfrak{J}_{R'}$ if and only if
$|J(R)|=|J(R')|$ and $R/J(R)\cong R'/J(R')$. Also, for a Jacobson graph
$\mathfrak{J}_R$, we obtain the structure of group
$\mathrm{Aut}(\mathfrak{J}_R)$ of all automorphisms of $\mathfrak{J}_R$ and
prove that under some conditions two semi-simple rings $R$ and $R'$ are
isomorphic if and only if
$\mathrm{Aut}(\mathfrak{J}_R)\cong\mathrm{Aut}(\mathfrak{J}_{R'})$.


title:
A Multicast Approach for Constructive Interference Precoding in MISO
  Downlink Channel

abstract:
  This paper studies the concept of jointly utilizing the data
information(DI)and channel state information (CSI) in order to design
symbol-level precoders for a multiple input and single output (MISO) downlink
channel. In this direction, the interference among the simultaneous data
streams is transformed to useful signal that can improve the signal to
interference noise ratio (SINR) of the downlink transmissions. We propose a
maximum ratio transmissions (MRT) based algorithm that jointly exploits DI and
CSI to gain the benefits from these useful signals. In this context, a novel
framework to minimize the power consumption is proposed by formalizing the
duality between the constructive interference downlink channel and the
multicast channels. The numerical results have shown that the proposed schemes
outperform other state of the art techniques.


title: Diophantine approximation exponents on homogeneous varieties

abstract:
  Recent years have seen very important developments at the interface of
Diophantine approximation and homogeneous dynamics. In the first part of the
paper we give a brief exposition of a dictionary developed by Dani and
Kleinbock-Margulis which relates Diophantine properties of vectors to
distribution of orbits of flows on the space of unimodular lattices. In the
second part of the paper we briefly describe an extension of this dictionary
recently developed by the authors, which establishes an analogous dynamical
correspondence for general lattice orbits on homogeneous spaces. We concentrate
specifically on the problem of estimating exponents of Diophantine
approximation by arithmetic lattices acting on algebraic varieties. In the
third part of the paper, we exemplify our results by establishing explicit
bounds for the Diophantine exponent of dense lattice orbits in a number of
basic cases.
  These include the linear and affine actions on affine spaces, and the action
on the variety of matrices of fixed determinant. In some cases, these exponents
are shown to be best possible.


title:
CSI 2264: Simultaneous optical and infrared light curves of young
  disk-bearing stars in NGC 2264 with CoRoT and Spitzer-- evidence for multiple
  origins of variability

abstract:
  We present the Coordinated Synoptic Investigation of NGC 2264, a continuous
30-day multi-wavelength photometric monitoring campaign on more than 1000 young
cluster members using 16 telescopes. The unprecedented combination of
multi-wavelength, high-precision, high-cadence, and long-duration data opens a
new window into the time domain behavior of young stellar objects. Here we
provide an overview of the observations, focusing on results from Spitzer and
CoRoT. The highlight of this work is detailed analysis of 162 classical T Tauri
stars for which we can probe optical and mid-infrared flux variations to 1%
amplitudes and sub-hour timescales. We present a morphological variability
census and then use metrics of periodicity, stochasticity, and symmetry to
statistically separate the light curves into seven distinct classes, which we
suggest represent different physical processes and geometric effects. We
provide distributions of the characteristic timescales and amplitudes, and
assess the fractional representation within each class. The largest category
(>20%) are optical "dippers" having discrete fading events lasting ~1-5 days.
The degree of correlation between the optical and infrared light curves is
positive but weak; notably, the independently assigned optical and infrared
morphology classes tend to be different for the same object. Assessment of flux
variation behavior with respect to (circum)stellar properties reveals
correlations of variability parameters with H$\alpha$ emission and with
effective temperature. Overall, our results point to multiple origins of young
star variability, including circumstellar obscuration events, hot spots on the
star and/or disk, accretion bursts, and rapid structural changes in the inner
disk.


title: The Radio Number of Grid Graphs

abstract:
  The radio number problem uses a graph-theoretical model to simulate optimal
frequency assignments on wireless networks. A radio labeling of a connected
graph $G$ is a function $f:V(G) \to \mathbb Z_{0}^+$ such that for every pair
of vertices $u,v \in V(G)$, we have $\lvert f(u)-f(v)\rvert \ge \text{diam}(G)
+ 1 - d(u,v)$ where $\text{diam}(G)$ denotes the diameter of $G$ and $d(u,v)$
the distance between vertices $u$ and $v$. Let $\text{span}(f)$ be the
difference between the greatest label and least label assigned to $V(G)$. Then,
the \textit{radio number} of a graph $\text{rn}(G)$ is defined as the minimum
value of $\text{span}(f)$ over all radio labelings of $G$. So far, there have
been few results on the radio number of the grid graph: In 2009 Calles and
Gomez gave an upper and lower bound for square grids, and in 2008 Flores and
Lewis were unable to completely determine the radio number of the ladder graph
(a 2 by $n$ grid). In this paper, we completely determine the radio number of
the grid graph $G_{a,b}$ for $a,b>2$, characterizing three subcases of the
problem and providing a closed-form solution to each. These results have
implications in the optimization of radio frequency assignment in wireless
networks such as cell towers and environmental sensors.


title: On the eigenvalue process of a matrix fractional Brownian motion

abstract:
  We investigate the process of eigenvalues of a symmetric matrix-valued
process which upper diagonal entries are independent one-dimensional H\"older
continuous Gaussian processes of order gamma in (1/2,1). Using the stochastic
calculus with respect to the Young's integral we show that these eigenvalues do
not collide at any time with probability one. When the matrix process has
entries that are fractional Brownian motions with Hurst parameter H in (1/2,1),
we find a stochastic differential equation in a Malliavin calculus sense for
the eigenvalues of the corresponding matrix fractional Brownian motion. A new
generalized version of the It\^o formula for the multidimensional fractional
Brownian motion is first established.


title:
Relativistic many-body calculations of van der Waals coefficients for
  Yb-Li and Yb-Rb dimers

abstract:
  We derive the relativistic formulas for the van der Waals coefficients of
Yb-alkali dimers that correlate to ground and excited separated-atom limits. We
calculate $C_6$ and $C_8$ coefficients of particular experimental interest. We
also derive a semi-empirical formula that expresses the $C_8$ coefficient of
heteronuclear $A+B$ dimers in terms of the $C_6$ and $C_8$ coefficients of
homonuclear dimers and the static dipole and quadrupole polarizabilities of the
atomic states $A$ and $B$. We report results of calculation of the $C_6$
coefficients for the Yb-Rb $^3/!P_1^o+5s\, ^2/!S_{1/2}$ and $^1/!S_0+5p\,
^2/!P^o_{1/2}$ dimers, and the $C_8$ coefficients for the Yb-Li $^1/!S_0+2s\,
^2/!S_{1/2}$ and Yb-Rb $^1/!S_0+5s\, ^2/!S_{1/2}$ dimers. Uncertainties are
estimated for all predicted properties.

categories: physics.atom-ph cond-mat.quant-gas physics.optics quant-ph


title:
Strong particle-hole asymmetry of charge instabilities in doped Mott
  insulators

abstract:
  We study possible charge instabilities in doped Mott insulators by employing
the two-dimensional t-J model with a positive value of the next
nearest-neighbor hopping integral t' on a square lattice, which is applicable
to electron-doped cuprates. Although the d-wave charge density wave (flux
phase) and d-wave Pomeranchuk instability (nematic order) are dominant
instabilities for a negative t' that corresponds to hole-doped cuprates, we
find that those instabilities are strongly suppressed and become relevant only
rather close to half filling. Instead, various types of bond orders with
modulation vectors close to (pi,pi) are dominant in a moderate doping region.
Phase separation is also enhanced, but it can be suppressed substantially by
the nearest-neighbor Coulomb repulsion without affecting the aforementioned
charge instabilities.


title: Deconstructing the governing dissipative phenomena in the nanoscale

abstract:
  An expression describing the controlling parameters involved in short range
nanoscale dissipation is proposed and supported by simulations and experimental
findings. The expression is deconstructed into the geometrical, dynamic,
chemical and mechanical properties of the system. In atomic force microscopy
these are translated into 1) tip radius and tip-sample deformation, 2) resonant
frequency and oscillation amplitude and 3) hysteretic and viscous dissipation.
The latter are characteristic parameters defining the chemical and mechanical
properties of the tip-sample system. Long range processes are also discussed
and footprints are identified in experiments conducted on mica and silicon
samples. The present methodology can be exploited to validate or invalidate
nanoscale dissipative models by comparing predictions with experimental
observables.


title: Combinatorial proofs of some Bell number formulas

abstract:
  In this note, we provide bijective proofs of some identities involving the
Bell number, as previously requested. Our arguments may be extended to yield a
generalization in terms of complete Bell polynomials. We also provide a further
interpretation for a related difference of Catalan numbers in terms of the
inclusion-exclusion principle.


title: Notes on Simple Modules over Leavitt Path Algebras

abstract:
  Given an arbitrary graph E and any field K, a new class of simple left
modules over the Leavitt path algebra L of the graph E over K is constructed by
using vertices that emit infinitely many edges. The corresponding annihilating
primitive ideals are described and is used to show that these new class of
simple L-modules are different from(that is non-isomorphic to) any of the
previously known simple modules. Using a Boolean subring of idempotents induced
by paths in E, bounds for the cardinality of the set of distinct isomorphism
classes of simple L-modules are given. We also append other information about
the Leavitt path algebra L(E) of a finite graph E over which every simple left
module is finitely presented.


title:
On the relationship between charge ordering and the Fermi arcs observed
  in underdoped high Tc superconductors

abstract:
  We address the origin of the recently discovered close correspondence between
the charge ordering wave vectors and the momentum-space separation between the
tips of the Fermi arcs seen in angle-resolved photoemission measurements in
underdoped high temperature superconducting cuprates. We calculate the Fermi
surface spectral weight for a charge density-wave model, assuming a Fermi
surface, charge ordering wave vectors and short correlation lengths similar to
those found experimentally. We show that the observation of wavevectors
spanning the tips of remnant Fermi surface sections signal Fermi surface
reconstruction by charge order, similar to archetypal charge density wave
materials, obviating the need to invoke pre-existing Fermi arcs as being
unstable to charge ordering. Our findings suggest that charge ordering plays a
central role in reconstructing the Fermi surface in underdoped cuprate
superconductors.


title: Non-renormalization theorems and N=2 supersymmetric backgrounds

abstract:
  The conditions for fully supersymmetric backgrounds of general N=2 locally
supersymmetric theories are derived based on the off-shell superconformal
multiplet calculus. This enables the derivation of a non-renormalization
theorem for a large class of supersymmetric invariants with higher-derivative
couplings. The theorem implies that the invariant and its first order variation
must vanish in a fully supersymmetric background. The conjectured relation of
one particular higher-derivative invariant with a specific five-dimensional
invariant containing the mixed gauge-gravitational Chern-Simons term is
confirmed.


title:
A central limit type theorem for Gaussian mixture approximations to the
  nonlinear filtering problem

abstract:
  Approximating the solution of the nonlinear filtering problem with Gaussian
mixtures has been a very popular method since the 1970s. However, the vast
majority of such approximations are introduced in an ad-hoc manner without
theoretical grounding. This work is a continuation of [4, 5], where we
described a rigorous Gaussian mixture approximation to the solution of the
filtering problem. We deduce here a refined estimate of the rate of convergence
of the approximation. We do this by proving a central limit type theorem for
the error process. We also find the optimal variances of the Gaussian measures
are of order $1/\sqrt{n}$. This implies, in particular, that the mean square
error of the approximation as defined in [4, 5] is of order $1/n$.


title:
Approximating classes of functions defined by a generalised modulus of
  smoothness

abstract:
  In the present paper, we use a generalised shift operator in order to define
a generalised modulus of smoothness. By its means, we define generalised
Lipschitz classes of functions, and we give their constructive characteristics.
Specifically, we prove certain direct and inverse types theorems in
approximation theory for best approximation by algebraic polynomials.


title:
Reduction of Nonlinear Embedded Boundary Models for Problems with
  Evolving Interfaces

abstract:
  Embedded boundary methods alleviate many computational challenges, including
those associated with meshing complex geometries and solving problems with
evolving domains and interfaces. Developing model reduction methods for
computational frameworks based on such methods seems however to be challenging.
Indeed, most popular model reduction techniques are projection-based, and rely
on basis functions obtained from the compression of simulation snapshots. In a
traditional interface-fitted computational framework, the computation of such
basis functions is straightforward, primarily because the computational domain
does not contain in this case a fictitious region. This is not the case however
for an embedded computational framework because the computational domain
typically contains in this case both real and ghost regions whose definitions
complicate the collection and compression of simulation snapshots. The problem
is exacerbated when the interface separating both regions evolves in time. This
paper addresses this issue by formulating the snapshot compression problem as a
weighted low-rank approximation problem where the binary weighting identifies
the evolving component of the individual simulation snapshots. The proposed
approach is application independent and therefore comprehensive. It is
successfully demonstrated for the model reduction of several two-dimensional,
vortex-dominated, fluid-structure interaction problems.


title: Regularized brain reading with shrinkage and smoothing

abstract:
  Functional neuroimaging measures how the brain responds to complex stimuli.
However, sample sizes are modest, noise is substantial, and stimuli are high
dimensional. Hence, direct estimates are inherently imprecise and call for
regularization. We compare a suite of approaches which regularize via
shrinkage: ridge regression, the elastic net (a generalization of ridge
regression and the lasso), and a hierarchical Bayesian model based on small
area estimation (SAE). We contrast regularization with spatial smoothing and
combinations of smoothing and shrinkage. All methods are tested on functional
magnetic resonance imaging (fMRI) data from multiple subjects participating in
two different experiments related to reading, for both predicting neural
response to stimuli and decoding stimuli from responses. Interestingly, when
the regularization parameters are chosen by cross-validation independently for
every voxel, low/high regularization is chosen in voxels where the
classification accuracy is high/low, indicating that the regularization
intensity is a good tool for identification of relevant voxels for the
cognitive task. Surprisingly, all the regularization methods work about equally
well, suggesting that beating basic smoothing and shrinkage will take not only
clever methods, but also careful modeling.


title: A Novel String Distance Function based on Most Frequent K Characters

abstract:
  This study aims to publish a novel similarity metric to increase the speed of
comparison operations. Also the new metric is suitable for distance-based
operations among strings. Most of the simple calculation methods, such as
string length are fast to calculate but does not represent the string
correctly. On the other hand the methods like keeping the histogram over all
characters in the string are slower but good to represent the string
characteristics in some areas, like natural language. We propose a new metric,
easy to calculate and satisfactory for string comparison. Method is built on a
hash function, which gets a string at any size and outputs the most frequent K
characters with their frequencies. The outputs are open for comparison and our
studies showed that the success rate is quite satisfactory for the text mining
operations.


title: Ensembled Correlation Between Liver Analysis Outputs

abstract:
  Data mining techniques on the biological analysis are spreading for most of
the areas including the health care and medical information. We have applied
the data mining techniques, such as KNN, SVM, MLP or decision trees over a
unique dataset, which is collected from 16,380 analysis results for a year.
Furthermore we have also used meta-classifiers to question the increased
correlation rate between the liver disorder and the liver analysis outputs. The
results show that there is a correlation among ALT, AST, Billirubin Direct and
Billirubin Total down to 15% of error rate. Also the correlation coefficient is
up to 94%. This makes possible to predict the analysis results from each other
or disease patterns can be applied over the linear correlation of the
parameters.


title:
Never forget, whom was my ancestors: A cross-cultural analysis from
  Yonsei (fourth-generation Nikkei) in four societies using Data Mining

abstract:
  This research explains the importance of transculturality in social
networking in a wide variety of activities of our daily life. We focus our
analysis to online activities that use social richness, analyzing societies in
Yakutia (A Russian Republic), Macau in China, Uberl\^andia in Brazil and Juarez
City in Mexico, all with people descending from Japanese people. To this end,
we performed surveys to gathering information about salient aspects of upgrade
and combined them using social data mining techniques to profile a number of
behavioural patterns and choices that describe social networking behaviours in
these societies.


title: Symmetries of filtered structures via the filtered Lie equations

abstract:
  We bound the symmetry algebra of a vector distribution, possibly equipped
with an additional structure, by the corresponding Tanaka algebra. The main
tool is the theory of weighted jets.


title:
CSI 2264: Characterizing Accretion-Burst Dominated Light Curves for
  Young Stars in NGC 2264

abstract:
  Based on more than four weeks of continuous high cadence photometric
monitoring of several hundred members of the young cluster NGC 2264 with two
space telescopes, NASA's Spitzer and the CNES CoRoT (Convection, Rotation, and
planetary Transits), we provide high quality, multi-wavelength light curves for
young stellar objects (YSOs) whose optical variability is dominated by short
duration flux bursts, which we infer are due to enhanced mass accretion rates.
These light curves show many brief -- several hour to one day -- brightenings
at optical and near-infrared (IR) wavelengths with amplitudes generally in the
range 5-50% of the quiescent value. Typically, a dozen or more of these bursts
occur in a thirty day period. We demonstrate that stars exhibiting this type of
variability have large ultraviolet (UV) excesses and dominate the portion of
the u-g vs. g-r color-color diagram with the largest UV excesses. These stars
also have large Halpha equivalent widths, and either centrally peaked, lumpy
Halpha emission profiles or profiles with blue-shifted absorption dips
associated with disk or stellar winds. Light curves of this type have been
predicted for stars whose accretion is dominated by Rayleigh-Taylor
instabilities at the boundary between their magnetosphere and inner
circumstellar disk, or where magneto-rotational instabilities modulate the
accretion rate from the inner disk. Amongst the stars with the largest UV
excesses or largest Halpha equivalent widths, light curves with this type of
variability greatly outnumber light curves with relatively smooth sinusoidal
variations associated with long-lived hot spots. We provide quantitative
statistics for the average duration and strength of the accretion bursts and
for the fraction of the accretion luminosity associated with these bursts.


title:
Model reduction for slow-fast stochastic systems with metastable
  behaviour

abstract:
  The quasi-steady-state approximation (or stochastic averaging principle) is a
useful tool in the study of multiscale stochastic systems, giving a practical
method by which to reduce the number of degrees of freedom in a model. The
method is extended here to slow-fast systems in which the fast variables
exhibit metastable behaviour. The key parameter that determines the form of the
reduced model is the ratio of the timescale for the switching of the fast
variables between metastable states to the timescale for the evolution of the
slow variables. The method is illustrated with two examples: one from
biochemistry (a fast-species-mediated chemical switch coupled to a
slower-varying species), and one from ecology (a predator-prey system).
Numerical simulations of each model reduction are compared with those of the
full system.


title:
Automatic detection of key innovations, rate shifts, and
  diversity-dependence on phylogenetic trees

abstract:
  A number of methods have been developed to infer differential rates of
species diversification through time and among clades using time-calibrated
phylogenetic trees. However, we lack a general framework that can delineate and
quantify heterogeneous mixtures of dynamic processes within single phylogenies.
I developed a method that can identify arbitrary numbers of time-varying
diversification processes on phylogenies without specifying their locations in
advance. The method uses reversible-jump Markov Chain Monte Carlo to move
between model subspaces that vary in the number of distinct diversification
regimes. The model assumes that changes in evolutionary regimes occur across
the branches of phylogenetic trees under a compound Poisson process and
explicitly accounts for rate variation through time and among lineages. Using
simulated datasets, I demonstrate that the method can be used to quantify
complex mixtures of time-dependent, diversity-dependent, and constant-rate
diversification processes. I compared the performance of the method to the
MEDUSA model of rate variation among lineages. As an empirical example, I
analyzed the history of speciation and extinction during the radiation of
modern whales. The method described here will greatly facilitate the
exploration of macroevolutionary dynamics across large phylogenetic trees,
which may have been shaped by heterogeneous mixtures of distinct evolutionary
processes.


title:
XMM-Newton and Chandra Observations of the Ejecta-Dominated
  Mixed-Morphology Galactic Supernova Remnant G352.7-0.1

abstract:
  (Abridged) We present a spatial and spectral X-ray analysis of the Galactic
supernova remnant (SNR) G352.7-0.1 using archival data from observations made
with XMM-Newton and Chandra. Prior X-ray observations of this SNR revealed a
thermal center-filled morphology which contrasts with a shell-like radio
morphology, thus establishing G352.7$-$0.1 as a mixed-morphology SNR (MMSNRs).
Our study confirms that the X-ray emission comes from the SNR interior and must
be ejecta-dominated. Spectra obtained with XMM-Newton may be fit satisfactorily
with a single thermal component (namely a non-equilibrium ionization component
with enhanced abundances of silicon and sulfur). In contrast, spectra extracted
by Chandra from certain regions of the SNR cannot always be fit by a single
thermal component. For those regions, a second thermal component with solar
abundances or two thermal components with different temperatures and thawed
silicon and sulfur abundances (respectively) can generate a
statistically-acceptable fit. We argue that the former scenario is more
physically-plausible: based on parameters of our spectral fits, we calculate
physical parameters including X-ray-emitting mass (about 45 solar masses, for
solar abundances). We find no evidence for overionization in the X-ray emitting
plasma associated with the SNR: this phenomenon has been seen in other MMSNRs.
We have conducted a search for a neutron star within the SNR using a hard (2-10
keV) Chandra image but could not identify a firm candidate. We also present
(for the first time) the detection of infrared emission from this SNR as
detected at 24 micron by MIPS aboard Spitzer. Finally, we discuss the
properties of G352.7-0.1 in the context of other ejecta-dominated MMSNRs.


title:
Constructing Boolean Functions With Potential Optimal Algebraic Immunity
  Based on Additive Decompositions of Finite Fields

abstract:
  We propose a general approach to construct cryptographic significant Boolean
functions of $(r+1)m$ variables based on the additive decomposition
$\mathbb{F}_{2^{rm}}\times\mathbb{F}_{2^m}$ of the finite field
$\mathbb{F}_{2^{(r+1)m}}$, where $r$ is odd and $m\geq3$. A class of unbalanced
functions are constructed first via this approach, which coincides with a
variant of the unbalanced class of generalized Tu-Deng functions in the case
$r=1$. This class of functions have high algebraic degree, but their algebraic
immunity does not exceeds $m$, which is impossible to be optimal when $r>1$. By
modifying these unbalanced functions, we obtain a class of balanced functions
which have optimal algebraic degree and high nonlinearity (shown by a lower
bound we prove). These functions have optimal algebraic immunity provided a
combinatorial conjecture on binary strings which generalizes the Tu-Deng
conjecture is true. Computer investigations show that, at least for small
values of number of variables, functions from this class also behave well
against fast algebraic attacks.


title:
Topological spin liquid phase in a low-dimensional organic molecular
  compound

abstract:
  We report the discovery of a correlated insulator with a bulk gap at
two-thirds filling in a geometrically frustrated Hubbard model that describes
the low-energy physics of Mo$_3$S$_7$(dmit)$_3$. This is very different from
the Mott insulator expected at half-filling. We show that the insulating phase,
which persists even for very weak electron-electron interactions ($U$), is
adiabatically connected to the Haldane phase and is consistent with experiments
on Mo$_3$S$_7$(dmit)$_3$


title:
Continuous Localization and Mapping of a Pan Tilt Zoom Camera for Wide
  Area Tracking

abstract:
  Pan-tilt-zoom (PTZ) cameras are powerful to support object identification and
recognition in far-field scenes. However, the effective use of PTZ cameras in
real contexts is complicated by the fact that a continuous on-line camera
calibration is needed and the absolute pan, tilt and zoom positional values
provided by the camera actuators cannot be used because are not synchronized
with the video stream. So, accurate calibration must be directly extracted from
the visual content of the frames. Moreover, the large and abrupt scale changes,
the scene background changes due to the camera operation and the need of camera
motion compensation make target tracking with these cameras extremely
challenging. In this paper, we present a solution that provides continuous
on-line calibration of PTZ cameras which is robust to rapid camera motion,
changes of the environment due to illumination or moving objects and scales
beyond thousands of landmarks. The method directly derives the relationship
between the position of a target in the 3D world plane and the corresponding
scale and position in the 2D image, and allows real-time tracking of multiple
targets with high and stable degree of accuracy even at far distances and any
zooming level.


title: An Accelerated Linearized Alternating Direction Method of Multipliers

abstract:
  We present a novel framework, namely AADMM, for acceleration of linearized
alternating direction method of multipliers (ADMM). The basic idea of AADMM is
to incorporate a multi-step acceleration scheme into linearized ADMM. We
demonstrate that for solving a class of convex composite optimization with
linear constraints, the rate of convergence of AADMM is better than that of
linearized ADMM, in terms of their dependence on the Lipschitz constant of the
smooth component. Moreover, AADMM is capable to deal with the situation when
the feasible region is unbounded, as long as the corresponding saddle point
problem has a solution. A backtracking algorithm is also proposed for practical
performance.


title: Floer homology and embedded bipartite graphs

abstract:
  We generalize the construction of the Heegaard Floer homology for a singular
knot to that for a balanced bipartite graph. For a given graph, we provide a
combinatorial description of the Euler characteristic of its Heegaard Floer
homology by using the "Kauffman states" on a graph diagram.


title: Classification of the Entangled States of $2 \times L \times M \times N$

abstract:
  We present a practical entanglement classification scheme for pure state in
form of $2\times L\times M\times N$ under the stochastic local operation and
classical communication (SLOCC), where every inequivalent class of the
entangled quantum states may be sorted out according to its standard form and
the corresponding transformation matrix. This provides a practical method for
determining the interconverting matrix between two SLOCC equivalent entangled
states, and classification examples for some $2\times 4\times M\times N$
systems are also presented.


title:
Permutation Relations of Yangian Invariants, Unitarity Cuts, and
  Scattering Amplitudes

abstract:
  We find a permutation relation among Yangian Invariants -- two Yangian
Invariants with adjacent external lines exchanged are related by a simple
kinematic factor. This relation is shown to be equivalent to U(1) decoupling
and Bern-Carrasco-Johansson (BCJ) relation at the level of maximal helicity
violating (MHV) amplitudes. Together with the newly found permutation relation
and using unitarity cuts to remove ambiguity in the definition of loop momenta
of cut amplitudes due to the nonplanar legs, we propose a systematic way of
reconstructing the the integrands of nonplanar MHV amplitudes up to a rational
function which vanishes under all possible unitarity cuts. This method when
applied to planar diagrams reproduces results from the single cut method. As
explicit examples the construction of one-loop double-trace MHV amplitudes of
4- and 5-point interactions are presented using on-shell diagrams. The
kinematic factors and the resultant planar diagrams are carefully dealt with
using the unitarity cut condition. The first next-to-MHV amplitudes are
addressed using generalized unitarity cuts. Their leading singularities can be
identified as residues of the Grassmanian integral. This example also serve to
demonstrate the power of the newly found relation of Yangian Invariants.


title: Double Character Sums over Subgroups and Intervals

abstract:
  We estimate double sums $$ S_\chi(a, I, G) = \sum_{x \in I} \sum_{\lambda \in
G} \chi(x + a\lambda), \qquad 1\le a < p-1, $$ with a multiplicative character
$\chi$ modulo $p$ where $I= \{1,\ldots, H\}$ and $G$ is a subgroup of order $T$
of the multiplicative group of the finite field of $p$ elements. A nontrivial
upper bound on $S_\chi(a, I, G)$ can be derived from the Burgess bound if $H
\ge p^{1/4+\varepsilon}$ and from some standard elementary arguments if $T \ge
p^{1/2+\varepsilon}$, where $\varepsilon>0$ is arbitrary. We obtain a
nontrivial estimate in a wider range of parameters $H$ and $T$. We also
estimate double sums $$ T_\chi(a, G) = \sum_{\lambda, \mu \in G} \chi(a +
\lambda + \mu), \qquad 1\le a < p-1, $$ and give an application to primitive
roots modulo $p$ with $3$ non-zero binary digits.


title: Has Hawking radiation been measured?

abstract:
  It is argued that Hawking radiation has indeed been measured and shown to
posses a thermal spectrum, as predicted. This contention is based on three
separate legs. The first is that the essential physics of the Hawking process
for black holes can be modelled in other physical systems. The second is the
white hole horizons are the time inverse of black hole horizons, and thus the
physics of both is the same. The third is that the quantum emission, which is
the Hawking process, is completely determined by measurements of the classical
parameters of a linear physical system. The experiment conducted in 2010
fulfills all of these requirements, and is thus a true measurement of Hawking
radiation.


title: High Energy Astrophysics

abstract:
  High energy astrophysics is one of the most active branches in contemporary
astrophysics. It studies astrophysical objects that emit X-ray and gamma-ray
photons, such as accreting super-massive and stellar-size black holes, and
various species of neutron stars. With the operations of many space-borne and
ground-based observational facilities, high energy astrophysics has enjoyed a
rapid development in the past decades. It is foreseen that the field will
continue to advance rapidly in the coming decade, with possible ground-breaking
discoveries of astrophysical sources in the high-energy neutrino and
gravitational wave channels. This Special Issue of Frontiers of Physics is
dedicated to a systematic survey of the field of high energy astrophysics as it
stands in 2013.


title: The twin prime conjecture

abstract:
  This is an exposition of recent developments in the theory of bounded
differences between primes. Readers are expected to be beginners of analytic
number theory.
  The present text is a substantially improved and augmented version of the one
that I had prepared for my talk which I delivered at the Annual Meeting of the
Mathematical Society of Japan on 15 March 2014.


title:
Iterative Approximate Consensus in the presence of Byzantine Link
  Failures

abstract:
  This paper explores the problem of reaching approximate consensus in
synchronous point-to-point networks, where each directed link of the underlying
communication graph represents a communication channel between a pair of nodes.
We adopt the transient Byzantine link failure model [15, 16], where an
omniscient adversary controls a subset of the directed communication links, but
the nodes are assumed to be fault-free.
  Recent work has addressed the problem of reaching approximate consen- sus in
incomplete graphs with Byzantine nodes using a restricted class of iterative
algorithms that maintain only a small amount of memory across iterations [22,
21, 23, 12]. However, to the best of our knowledge, we are the first to
consider approximate consensus in the presence of Byzan- tine links. We extend
our past work that provided exact characterization of graphs in which the
iterative approximate consensus problem in the presence of Byzantine node
failures is solvable [22, 21]. In particular, we prove a tight necessary and
sufficient condition on the underlying com- munication graph for the existence
of iterative approximate consensus algorithms under transient Byzantine link
model. The condition answers (part of) the open problem stated in [16].


title: A universal form for quark and neutrino mass matrices

abstract:
  We propose a universal form for quark and lepton mass matrices, which applies
in a ``leading order'' approximation where $CP$-violating phases are ignored.
Down-quark mass ratios are successfully predicted in our scheme using the
measured CKM mixing angles as input. Assuming an additional discrete symmetry
in the neutrino sector, we obtain the ``golden ratio'' pattern in the
leading-order PMNS mixing matrix; in addition we predict an inverted neutrino
mass hierarchy with $m_1\simeq m_2 \simeq74 meV$, $m_3\simeq 55 meV$, and
neutrinoless double beta decay mass parameter $m_{0\nu\beta\beta}\simeq 33~
meV$. We also predict that the $CP$-violating angle in the neutrino sector is
close to the maximal value $\delta=\pm\pi/2$, and that the diagonal phases in
the PMNS matrix are $\alpha_1\simeq 0$, $\alpha_2\simeq\pi$.


title:
Boundedness of vector-valued intrinsic square functions in Morrey type
  spaces

abstract:
  In this paper, we will obtain the strong type and weak type estimates for
vector-valued analogues of intrinsic square functions in the weighted Morrey
spaces $L^{p,\kappa}(w)$ when $1\leq p<\infty$, $0<\kappa<1$, and in the
generalized Morrey spaces $L^{p,\Phi}$ for $1\le p<\infty$, where $\Phi$ is a
growth function on $(0,\infty)$ satisfying the doubling condition.


title: Cycles and paths in Jacobson graphs

abstract:
  All finite Jacobson graphs with a Hamiltonian cycle or path, or Eulerian tour
or trail are determined, and it is shown that a finite Jacobson graph is
Hamiltonian if and only if it is pancyclic. Also, the length of the longest
induced cycles and paths in finite Jacobson graphs are obtained.


title: On cycles in intersection graph of rings

abstract:
  Let $R$ be a commutative ring with non-zero identity. We describe all $C_3$-
and $C_4$-free intersection graph of non-trivial ideals of $R$ as well as
$C_n$-free intersection graph when $R$ is a reduced ring. Also, we shall
describe all complete, regular and $n$-claw-free intersection graphs. Finally,
we shall prove that almost all Artin rings $R$ have Hamiltonian intersection
graphs. We show that such graphs are indeed pancyclic.


title: Physical white chaos generation

abstract:
  Physical chaos is a fascinating prospect for high-speed data security by
serving as a masking carrier or a key source, but suffers from a colored
spectrum that divulges system's intrinsic oscillations and degrades randomness.
Here, we demonstrate that physical chaos with a white spectrum can be achieved
by the optical heterodyning of two delayed-feedback lasers. A white chaotic
spectrum with 1-dB fluctuation in a band of 11 GHz is experimentally obtained.
The white chaos also has a perfect delta-like autocorrelation function and a
high dimensionality of greater than 10, which makes chaos reconstruction
extremely difficult and thus improves security.


title:
Particle Swarm Optimization for Mobility Load Balancing SON in LTE
  Networks

abstract:
  This paper presents a self-optimizing solution for Mobility Load Balancing
(MLB). The MLB-SON is performed in two phases. In the first, a MLB controller
is designed using Multi-Objective Particle Swarm Optimization (MO-PSO) which
incorporates a priori expert knowledge to considerably reduce the search space
and optimization time. The dynamicity of the optimization phase is addressed.
In the second phase, the controller is pushed into the base stations to
implement the MLB SON. The method is applied to dynamically adapt Handover
Margin parameters of a large scale LTE network in order to balance traffic of
the network eNodeBs. Numerical results illustrate the benefits of the proposed
solution.


title: Simple forms of SLOCC equivalent four-qubit \c{hi} state

abstract:
  Some simple structure of maximally four-qubit state is presented. Using
stochastic local operations and classical communication (SLOCC) invariants, it
is can be shown those simple structure of maximally four-qubit state is SLOCC
equivalent to four-qubit \c{hi} state.


title: Near-Ideal Behavior of Compressed Sensing Algorithms

abstract:
  In a recent paper, it is shown that the LASSO algorithm exhibits "near-ideal
behavior," in the following sense: Suppose $y = Az + \eta$ where $A$ satisfies
the restricted isometry property (RIP) with a sufficiently small constant, and
$\Vert \eta \Vert_2 \leq \epsilon$. Then minimizing $\Vert z \Vert_1$ subject
to $\Vert y - Az \Vert_2 \leq \epsilon$ leads to an estimate $\hat{x}$ whose
error $\Vert \hat{x} - x \Vert_2$ is bounded by a universal constant times the
error achieved by an "oracle" that knows the location of the nonzero components
of $x$. In the world of optimization, the LASSO algorithm has been generalized
in several directions such as the group LASSO, the sparse group LASSO, either
without or with tree-structured overlapping groups, and most recently, the
sorted LASSO. In this paper, it is shown that {\it any algorithm\/} exhibits
near-ideal behavior in the above sense, provided only that (i) the norm used to
define the sparsity index is "decomposable," (ii) the penalty norm that is
minimized in an effort to enforce sparsity is "$\gamma$-decomposable," and
(iii) a "compressibility condition" in terms of a group restricted isometry
property is satisfied. Specifically, the group LASSO, and the sparse group
LASSO (with some permissible overlap in the groups), as well as the sorted
$\ell_1$-norm minimization all exhibit near-ideal behavior. Explicit bounds on
the residual error are derived that contain previously known results as special
cases.


title:
Similarity reductions and new nonlinear exact solutions for the 2D
  incompressible Euler equations

abstract:
  For the 2D and 3D Euler equations, their existing exact solutions are often
in linear form with respect to variables x,y,z. In this paper, the
Clarkson-Kruskal reduction method is applied to reduce the 2D incompressible
Euler equations to a system of completely solvable ordinary equations, from
which several novel nonlinear exact solutions with respect to the variables x
and y are found.


title: Hadron Multiplicities in p+p and p+Pb Collisions

abstract:
  Experiments at the Large Hadron Collider (LHC) have measured multiplicity
distributions in p+p and p+Pb collisions at a new domain of collision energy.
Based on considering an energy-dependent broadening of the nucleon's density
distribution, charged hadron multiplicities are studied with the
phenomenological saturation model and the evolution equation dependent
saturation model. By assuming the saturation scale have a small dependence on
the 3-dimensional root mean square (rms) radius at different energy, the
theoretical results are in good agreement with the experimental data from CMS
and ALICE collaboration. Then, the predictive results in p+p collisions at
$\sqrt{s}=$ 14 TeV of the LHC are also given.


title:
Completion Time Reduction in Instantly Decodable Network Coding Through
  Decoding Delay Control

abstract:
  For several years, the completion time and decoding delay problems in
Instantly Decodable Network Coding (IDNC) were considered separately and were
thought to completely act against each other. Recently, some works aimed to
balance the effects of these two important IDNC metrics but none of them
studied a further optimization of one by controlling the other. In this paper,
we study the effect of controlling the decoding delay to reduce the completion
time below its currently best known solution. We first derive the
decoding-delay-dependent expressions of the users' and overall completion
times. Although using such expressions to find the optimal overall completion
time is NP-hard, we design a novel heuristic that minimizes the probability of
increasing the maximum of these decoding-delay-dependent completion time
expressions after each transmission through a layered control of their decoding
delays. Simulation results show that this new algorithm achieves both a lower
mean completion time and mean decoding delay compared to the best known
heuristic for completion time reduction. The gap in performance becomes
significant for harsh erasure scenarios.


title: On the holonomy group of hypersurfaces

abstract:
  Hypersurfaces of manifolds of constant nonzero sectional curvature are
classificated according their restricted homogeneous holonomy groups.


title:
BigOP: Generating Comprehensive Big Data Workloads as a Benchmarking
  Framework

abstract:
  Big Data is considered proprietary asset of companies, organizations, and
even nations. Turning big data into real treasure requires the support of big
data systems. A variety of commercial and open source products have been
unleashed for big data storage and processing. While big data users are facing
the choice of which system best suits their needs, big data system developers
are facing the question of how to evaluate their systems with regard to general
big data processing needs. System benchmarking is the classic way of meeting
the above demands. However, existent big data benchmarks either fail to
represent the variety of big data processing requirements, or target only one
specific platform, e.g. Hadoop.
  In this paper, with our industrial partners, we present BigOP, an end-to-end
system benchmarking framework, featuring the abstraction of representative
Operation sets, workload Patterns, and prescribed tests. BigOP is part of an
open-source big data benchmarking project, BigDataBench. BigOP's abstraction
model not only guides the development of BigDataBench, but also enables
automatic generation of tests with comprehensive workloads.
  We illustrate the feasibility of BigOP by implementing an automatic test
generation tool and benchmarking against three widely used big data processing
systems, i.e. Hadoop, Spark and MySQL Cluster. Three tests targeting three
different application scenarios are prescribed. The tests involve relational
data, text data and graph data, as well as all operations and workload
patterns. We report results following test specifications.


title:
The Origin of the Galactic Center Diffuse X-ray Emission Investigated by
  Near-infrared Imaging and Polarimetric Observations

abstract:
  The origin of the Galactic center diffuse X-ray emission (GCDX) is still
under intense investigation. We have found a clear excess in a longitudinal
GCDX profile over a stellar number density profile in the nuclear bulge region,
suggesting a significant contribution of diffuse, interstellar hot plasma to
the GCDX. We have estimated that contributions of an old stellar population to
the GCDX are about 50 % and 20 % in the nuclear stellar disk and nuclear star
cluster, respectively. Our near-infrared polarimetric observations show that
the GCDX region is permeated by a large scale, toroidal magnetic field.
Together with observed magnetic field strengths in nearly energy equipartition,
the interstellar hot plasma could be confined by the toroidal magnetic field.


title:
Higher derivative corrections of $f(R)$ gravity with varying equation of
  state in the case of variable $G$ and $\Lambda$

abstract:
  In this paper, we study three models of f(R) modified gravity including
higher order terms based on different equation of state parameter. We also
assume variable G and $\Lambda$. By using numerical analysis, we obtain the
behavior of some important cosmological parameters, like the Hubble expansion H
parameter and the deceleration parameter q. The statefinder diagnostics is also
performed for all models.


title:
Lattice parameters and stability of the spinel compounds in relation to
  the ionic radii and electronegativities of constituting chemical elements

abstract:
  A thorough consideration of the relation between the lattice parameters of
185 binary and ternary spinel compounds, on one side, and ionic radii and
electronegativities of the constituting ions, on the other side, allowed for
establishing a simple empirical model and finding its linear equation, which
links together the above-mentioned quantities. The derived equation gives good
agreement between the experimental and modeled values of the lattice parameters
in the considered group of spinels, with an average relative error of about 1%
only. The proposed model was improved further by separate consideration of
several groups of spinels, depending on the nature of the anion (oxygen,
sulfur, selenium/tellurium, nitrogen). The developed approach can be
efficiently used for prediction of lattice constants for new isostructural
materials. In particular, the lattice constants of new hypothetic spinels
ZnRE2O4, CdRE2S4, CdRE2Se4 (RE=rare earth elements) are predicted in the
present paper. In addition, the upper and lower limits for the variation of the
ionic radii, electronegativities and certain their combinations were
established, which can be considered as stability criteria for the spinel
compounds. The findings of the present paper offer a systematic overview of the
structural properties of spinels and can serve as helpful guides for synthesis
of new spinel compounds.


title: Remarks on Ekedahl-Oort stratifications

abstract:
  This short paper is a continuation of the author's Ph.D thesis, where
Ekedahl-Oort strata are defined and studied for Shimura varieties of Hodge
type. The main results here are as follows.
  1. The Ekedahl-Oort stratification is independent of the choices of
symplectic embeddings.
  2. Under certain reasonable assumptions, there is certain functoriality for
Ekedahl-Oort stratifications with respect to morphisms of Shimura varieties.


title:
Payoff Allocation of Service Coalition in Wireless Mesh Network: A
  Cooperative Game Perspective

abstract:
  In wireless mesh network (WMN), multiple service providers (SPs) can
cooperate to share resources (e.g., relay nodes and spectrum), to serve their
collective subscribed customers for better service. As a reward, SPs are able
to achieve more individual benefits, i.e., increased revenue or decreased cost,
through efficient utilization of shared network resources. However, this
cooperation can be realized only if fair allocation of aggregated payoff, which
is the sum of the payoff of all the cooperative SPs, can be achieved. We first
formulate such cooperation as a coalitional game with transferable utility,
specifically, a linear programming game, in which, each SP should obtain the
fair share of the aggregated payoff. Then we study the problem of allocating
aggregated payoff which leads to stable service coalition of SPs in WMN based
on the concepts of dual payoff and Shapley value.


title: Hermitian Self-Dual Cyclic Codes of Length $p^a$ over $GR(p^2,s)$

abstract:
  In this paper, we study cyclic codes over the Galois ring ${\rm
GR}({p^2},s)$. The main result is the characterization and enumeration of
Hermitian self-dual cyclic codes of length $p^a$ over ${\rm GR}({p^2},s)$.
Combining with some known results and the standard Discrete Fourier Transform
decomposition, we arrive at the characterization and enumeration of Euclidean
self-dual cyclic codes of any length over ${\rm GR}({p^2},s)$. Some corrections
to results on Euclidean self-dual cyclic codes of even length over
$\mathbb{Z}_4$ in Discrete Appl. Math. 128, (2003), 27 and Des. Codes Cryptogr.
39, (2006), 127 are provided.


title: Moduli of autodual instanton bundles

abstract:
  We provide a description of the moduli space of framed autodual instanton
bundles on projective space, focusing on the particular cases of symplectic and
orthogonal instantons. Our description will use the generalized ADHM equations
which define framed instanton sheaves.


title: Semicircle law for a matrix ensemble with dependent entries

abstract:
  We study ensembles of random symmetric matrices whose entries exhibit certain
correlations. Examples are distributions of Curie-Weiss-type. We provide a
criterion on the correlations ensuring the validity of Wigner's semicircle law
for the eigenvalue distribution measure. In case of Curie-Weiss distributions
this criterion applies above the critical temperature (i.e. $\beta<1$). We also
investigate the largest eigenvalue of certain ensembles of Curie-Weiss type and
find a transition in its behavior at the critical temperature.


title: Convergence of T\^atonnement in Fisher Markets

abstract:
  Analyzing simple and natural price-adjustment processes that converge to a
market equilibrium is a fundamental question in economics. Such an analysis may
have implications in economic theory, computational economics, and distributed
systems. T\^atonnement, proposed by Walras in 1874, is a process by which
prices go up in response to excess demand, and down in response to excess
supply. This paper analyzes the convergence of a time-discrete t\^atonnement
process, a problem that recently attracted considerable attention of computer
scientists. We prove that the simple t\^atonnement process that we consider
converges (efficiently) to equilibrium prices and allocation in markets with
nested CES-Leontief utilities, generalizing some of the previous convergence
proofs for more restricted types of utility functions.


title: Painting Analysis Using Wavelets and Probabilistic Topic Models

abstract:
  In this paper, computer-based techniques for stylistic analysis of paintings
are applied to the five panels of the 14th century Peruzzi Altarpiece by Giotto
di Bondone. Features are extracted by combining a dual-tree complex wavelet
transform with a hidden Markov tree (HMT) model. Hierarchical clustering is
used to identify stylistic keywords in image patches, and keyword frequencies
are calculated for sub-images that each contains many patches. A generative
hierarchical Bayesian model learns stylistic patterns of keywords; these
patterns are then used to characterize the styles of the sub-images; this in
turn, permits to discriminate between paintings. Results suggest that such
unsupervised probabilistic topic models can be useful to distill characteristic
elements of style.


title: On the Alfven wave cut-off in partly ionized collisional plasmas

abstract:
  The cut-off of the Alfven wave, caused by plasma collisions with neutrals in
multi-component partially ionized plasmas, is discussed.
  Full multi-component theory is used, and similarities and differences
regarding the classic magnetohydrodynamic theory are presented.
  It is shown that the cut-off in partially ionized plasma in principle may
remain the same as predicted in classic magnetohydrodynamic works, although
multi-component theory also yields some essential differences. Due to electric
field, the ion motion is intrinsically two-dimensional and this results in
additional forced oscillations of neutrals. One new small parameter, containing
the ion inertial length, appears in the multi-component theory. This new small
parameter is missing in the magnetohydrodynamic description, and it turns out
that for some parameters it may be greater than the ions-to-neutrals density
ratio which is the only small parameter in the magnetohydrodynamic description.
Due to this the Alfven wave behavior can become much different as compared to
classic magnetohydrodynamic results. It is shown also that in plasmas with
unmagnetized ions, Alfv}n waves cannot be excited. This by all means applies to
the solar photosphere where the ion collision frequency may be far above the
ion gyro-frequency.


title: Forensic Statistics and Justice: the Leiden Consensus

abstract:
  Between 26 and 29 April 2011 a four-day interdisciplinary workshop "Science
meets Law" was held at the Lorentz Center (University of Leiden, NL). It was
organised by the Lorentz Center in collaboration with the Netherlands Institute
for Advanced Study in the Humanities and Social Sciences ("NIAS", Wassenaar,
NL). The programme was prepared by Richard Gill and Johannes F. Nijboer and
connected to Richard Gill's 2010-2011 stay at NIAS as Distinguished Lorentz
Fellow.
  This document was prepared by three of us and represents our personal
synthesis of the discussions which took place during the meeting. Comments are
welcome.


title:
Raman process under condition of radiation trapping in a disordered
  atomic medium

abstract:
  We consider the Raman process developing in a disordered medium of
alkali-metal atoms when the scattered modes are trapped on a closed transition.
Our theoretical analysis, based on numerical simulations of the Bethe-Salpeter
equation for the light correlation function, which includes all Zeeman states
and light polarization, lets us track the stimulated amplification as well as
the losses associated with the inverse anti-Stokes scattering channel. We
discuss possible conditions when this process could approach the instability
point and enter the regime of random lasing.


title: Synchrony in Neuronal Communications: An Energy Efficient Scheme

abstract:
  We are interested in understanding the neural correlates of attentional
processes using first principles. Here we apply a recently developed first
principles approach that uses transmitted information in bits per joule to
quantify the energy efficiency of information transmission for an
inter-spike-interval (ISI) code that can be modulated by means of the synchrony
in the presynaptic population. We simulate a single compartment
conductance-based model neuron driven by excitatory and inhibitory spikes from
a presynaptic population, where the rate and synchrony in the presynaptic
excitatory population may vary independently from the average rate. We find
that for a fixed input rate, the ISI distribution of the post synaptic neuron
depends on the level of synchrony and is well-described by a Gamma distribution
for synchrony levels less than 50%. For levels of synchrony between 15% and 50%
(restricted for technical reasons), we compute the optimum input distribution
that maximizes the mutual information per unit energy. This optimum
distribution shows that an increased level of synchrony, as it has been
reported experimentally in attention-demanding conditions, reduces the mode of
the input distribution and the excitability threshold of post synaptic neuron.
This facilitates a more energy efficient neuronal communication.