title:
Seeding Influential Nodes in Non-Submodular Models of Information
  Diffusion

abstract:
  We consider the model of information diffusion in social networks from
\cite{Hui2010a} which incorporates trust (weighted links) between actors, and
allows actors to actively participate in the spreading process, specifically
through the ability to query friends for additional information. This model
captures how social agents transmit and act upon information more realistically
as compared to the simpler threshold and cascade models. However, it is more
difficult to analyze, in particular with respect to seeding strategies. We
present efficient, scalable algorithms for determining good seed sets --
initial nodes to inject with the information. Our general approach is to reduce
our model to a class of simpler models for which provably good sets can be
constructed. By tuning this class of simpler models, we obtain a good seed set
for the original more complex model. We call this the \emph{projected greedy
approach} because you `project' your model onto a class of simpler models where
a greedy seed set selection is near-optimal. We demonstrate the effectiveness
of our seeding strategy on synthetic graphs as well as a realistic San Diego
evacuation network constructed during the 2007 fires.


title:
Well-posedness in energy space for the periodic modified Benjamin-Ono
  equation

abstract:
  We prove that the periodic modified Benjamin-Ono equation is locally
well-posed in the energy space $H^{1/2}$. This ensures the global
well-posedness in the defocusing case. The proof is based on an $X^{s,b}$
analysis of the system after gauge transform.


title: Non-complicated EuTiO3 Structure

abstract:
  A recently published paper [arXiv:1206.5417 ]showed strong incommensurate
diffraction peaks in EuTiO3 around zone boundary R-points. We wish to convey
that in our samples, and, it seems, at least another case from the literature,
these peaks are absent.


title:
A minimally constrained model of self-organized helical states in
  reversed-field pinches

abstract:
  We show that the self-organized single-helical-axis (SHAx) and
double-helical-axis (DAx) states in reversed field pinches can be reproduced in
a minimally constrained equilibrium model using only five parameters. This is a
significant reduction on previous representations of the SHAx which have
required an infinite number of constraints. The DAx state, which has a
non-trivial topology, has not been previously reproduced using an equilibrium
model that preserves this topological structure. We show that both states are a
consequence of transport barrier formation in the plasma core, in agreement
with experimental results.


title:
Time-Dependent Gaussian Solution for the Kostin Equation around
  Classical Trajectories

abstract:
  The structure of time-dependent Gaussian solutions for the Kostin equation in
dissipative quantum mechanics is analyzed. Expanding the generic external
potential near the center of mass of the wave packet, one conclude that: the
center of mass follows the dynamics of a classical particle under the external
potential and a damping proportional to the velocity; the width of the wave
packet satisfy a non-conservative Pinney equation. An appropriate perturbation
theory is developed for the free particle case, solving the long standing
problem of finding analytic expressions for square integrable solutions of the
free Kostin equation. The associated Wigner function is also studied.


title: CMOS-Compatible Nanowire Biosensors

abstract:
  In this chapter, silicon nanowires that are compatible with CMOS fabrication
processes have been described. It has been shown that these nanowires can be
functionalized by conjugating monoclonal antibodies to their surface in order
to build sensitive biochemical sensors. It has also been shown that by using
frequency-based signals, all the necessary components to interrogate these
nanowires can be built on low-cost CMOS processes.


title:
Geometric framework for modeling nonlinear flows in porous media, and
  its applications in engineering

abstract:
  This work represents an application of constant mean curvature graphs (as
solutions of the mean curvature PDE) to non-linear non-Darcy flows in porous
media. It relates time invariant pressure distribution graphs to graphs of
constant mean curvature surfaces. This differential geometric interpretation
provides an important tool for evaluating technological parameters in reservoir
engineering.


title: Dark Matter annihilation energy output and its effects on the high-z IGM

abstract:
  We study the case of DM self annihilation, in order to assess its importance
as an energy injection mechanism, to the IGM in general, and to the medium
within particular DM haloes. We consider thermal relic WIMP particles with
masses of 10GeV and 1TeV and we analyse in detail the clustering properties of
DM in a $\Lambda$CDM cosmology, on all hierarchy levels, from haloes and their
mass function, to subhaloes and the DM density profiles within them,
considering adiabatic contraction by the presence of a SMBH. We then compute
the corresponding energy output, concluding that DM annihilation does not
constitute an important feedback mechanism. We also calculate the effects that
DM annihilation has on the IGM temperature and ionization fraction, and we find
that assuming maximal energy absorption, at z ~ 10, for the case of a 1TeV
WIMP, the ionization fraction could be raised to $6 \times 10^{-4}$ and the
temperature to 10K, and in the case of a 10GeV WIMP, the IGM temperature could
be raised to 200K and the ionization fraction to $8 \times 10^{-3}$. We
conclude that DM annihilations cannot be regarded as an alternative
reionization scenario. Regarding the detectability of the WIMP through the
modifications to the 21 cm differential brightness temperature signal
($\delta$Tb), we conclude that a thermal relic WIMP with mass of 1TeV is not
likely to be detected from the global signal alone, except perhaps at the 1-3mK
level in the frequency range 30MHz < $\nu$ < 35MHz corresponding to 40 < z <
46. However, a 10GeV mass WIMP may be detectable at the 1-3mK level in the
frequency range 55MHz < $\nu$ < 119MHz corresponding to 11 < z < 25, and at the
1-10mK level in the frequency range 30MHz < $\nu$ < 40MHz corresponding to 35 <
z < 46.


title: Schr\"odinger equations with time-dependent strong magnetic fields

abstract:
  We consider d-dimensional time dependent Schr\"odinger equations on the
Hilbert space of square integrable functions. We assume magnetic and scalar
potentials are almost critically singular with respect to spatial variables
both locally and at infinity for the fixed time Schr\"odinger operator H(t) to
be essentially self-adjoint on the compactly supported smooth functions. In
particular, if magnetic field B(t,x) is very strong at infinity, the scalar
potential can explode to negative infinity faster than quadratic functions. We
show that equations uniquely generate unitary propagators under suitable
conditions on the size and singularities of time derivatives of potentials.
Basic tools are Kato's abstract theory for evolution equations, Iwatsuka's
identity which rewrites H(t) to an elliptic differential operator in which
B(t,x) appears explicitly, and a new diamagnetic like inequality.


title: Canonical Tensor Model with Local Time and its Uniqueness

abstract:
  A canonical formalism of the rank-three tensor model with the notion of local
time is proposed. The consistency of the local time evolution is guaranteed by
imposing that local Hamiltonians and the so(N) kinematical symmetry of the
tensor model should form a first class constraint algebra. By imposing some
physically reasonable assumptions, it is shown that there exist only two such
local Hamiltonians with a slight difference in index contraction. The first
class constraint algebra is shown to approach the DeWitt constraint algebra of
the general relativity in a certain locality limit. Quantization of the system
is briefly discussed.


title:
Anderson Localization of cold atomic gases with effective spin-orbit
  interaction in a quasiperiodic optical lattice

abstract:
  We theoretically investigate the localization properties of a spin-orbit
coupled spin-1/2 particle moving in a one-dimensional quasiperiodic potential,
which can be experimentally implemented using cold atoms trapped in a
quasiperiodic optical lattice potential and external laser fields. We present
the phase diagram in the parameter space of the disorder strength and those
related to the spin-orbit coupling. The phase diagram is verified via
multifractal analysis of the atomic wavefunctions and the numerical simulation
of diffusion dynamics. We found that spin-orbit coupling can lead to the
spectra mixing (coexistence of extended and localized states) and the
appearance of mobility edges.


title:
Possible $\Sigma^*(1/2^-)$ in the initial-state polarized $\gamma
  N\rightarrow K^{+} \Sigma^*(1385) \rightarrow K^{+} \pi \Lambda$ reaction
  near threshold

abstract:
  By using an effective Lagrangian method, we study the effects of a newly
proposed $\Sigma^*(1/2^-)$ state with mass around 1380 MeV in the initial-state
polarized $\gamma N\rightarrow K^{+} \Sigma^*(1385) \rightarrow K^{+} \pi
\Lambda$ process near threshold. The theoretical predictions for the helicity
cross sections $\sigma_{3/2}$, $\sigma_{1/2}$ as well as their ratios, and the
angular distributions of $\pi$ in the $\pi\Lambda$ center-of-mass system are
given. It is found that assuming $\Sigma^*(1/2^-)$ exists or not, these
physical quantities are distinctly different. So our results could be useful
for the investigation of the existence of $\Sigma^*(1/2^-)$ when the
experimental data are available in the future.


title: Charge order in Kondo lattice systems

abstract:
  Charge order is a commonly observed phenomenon in strongly correlated
materials. However, most theories are based on a repulsive inter-site Coulomb
interaction in order to explain charge order. We here show that only due to
local interactions, charge order is favorable in heavy fermion systems at
quarter filling. The driving force is the Kondo effect, which leads to a
non-linear dependence on the filling of the lattice site for the energy gain.
We use dynamical mean field theory combined with numerical renormalization
group to demonstrate the existence of charge order at quarter filling for a
Kondo lattice model.


title: What does the proof of Birnbaum's theorem prove?

abstract:
  Birnbaum's theorem, that the sufficiency and conditionality principles entail
the likelihood principle, has engendered a great deal of controversy and
discussion since the publication of the result in 1962. In particular, many
have raised doubts as to the validity of this result. Typically these doubts
are concerned with the validity of the principles of sufficiency and
conditionality as expressed by Birnbaum. Technically it would seem, however,
that the proof itself is sound. In this paper we use set theory to formalize
the context in which the result is proved and show that in fact Birnbaum's
theorem is incorrectly stated as a key hypothesis is left out of the statement.
When this hypothesis is added, we see that sufficiency is irrelevant, and that
the result is dependent on a well-known flaw in conditionality that renders the
result almost vacuous.


title: Geodesic systems of tunnels in hyperbolic 3-manifolds

abstract:
  It is unknown whether an unknotting tunnel is always isotopic to a geodesic
in a finite volume hyperbolic 3-manifold. In this paper, we address the
generalization of this problem to hyperbolic 3-manifolds admitting tunnel
systems. We show that there exist finite volume hyperbolic 3-manifolds with a
single cusp, with a system of at least two tunnels, such that all but one of
the tunnels come arbitrarily close to self-intersecting. This gives evidence
that systems of unknotting tunnels may not be isotopic to geodesics in tunnel
number n manifolds. In order to show this result, we prove there is a
geometrically finite hyperbolic structure on a (1;n)-compression body with a
system of core tunnels such that all but one of the core tunnels
self-intersect.


title: Controlling hole spins in quantum dots and wells

abstract:
  We review recent theoretical results for hole spins influenced by spin-orbit
coupling and Coulomb interaction in two-dimensional quantum wells as well as
the decoherence of single hole spins in quantum dots due to hyperfine
interaction with surrounding nuclear spins. After reviewing the different forms
of spin-orbit coupling that are relevant for electrons and heavy holes in III-V
semiconductor quantum wells, we illustrate the combined effect of spin-orbit
coupling and Coulomb interactions for hole systems on spin-dependent
quasiparticle group velocities. We further analyze spin-echo decay for a single
hole spin in a nuclear-spin bath, demonstrating that this decoherence source
can be controlled in these systems by entering a motional-averaging regime.
Throughout this review, we emphasize physical effects that are unique to hole
spins (rather than electrons) in nanoscale systems.


title: Milli-Charged Dark Matter in Quantum Gravity and String Theory

abstract:
  We examine the milli-charged dark matter scenario from a string theory
perspective. In this scenario, kinetic and mass mixings of the photon with
extra U(1) bosons are claimed to give rise to small electric charges, carried
by dark matter particles, whose values are determined by continuous parameters
of the theory. This seems to contradict folk theorems of quantum gravity that
forbid the existence of irrational charges in theories with a single massless
gauge field. By considering the underlying structure of the U(1) mass matrix
that appears in type II string compactifications, we show that milli-charges
arise exclusively through kinetic mixing, and require the existence of at least
two exactly massless gauge bosons.


title:
Variational Principles for Minkowski Type Problems, Discrete Optimal
  Transport, and Discrete Monge-Ampere Equations

abstract:
  In this paper, we develop several related finite dimensional variational
principles for discrete optimal transport (DOT), Minkowski type problems for
convex polytopes and discrete Monge-Ampere equation (DMAE). A link between the
discrete optimal transport, discrete Monge-Ampere equation and the power
diagram in computational geometry is established.


title:
P-shell nuclei using Similarity Renormalization Group evolved
  three-nucleon interactions

abstract:
  The Similarity Renormalization Group (SRG) is used to soften interactions for
ab initio nuclear structure calculations by decoupling low- and high-energy
Hamiltonian matrix elements. The substantial contribution of both initial and
SRG-induced three-nucleon forces requires their consistent evolution in a
three-particle basis space before applying them to larger nuclei. While in
principle the evolved Hamiltonians are unitarily equivalent, in practice the
need for basis truncation introduces deviations, which must be monitored. Here
we present benchmark no-core full configuration calculations with SRG-evolved
interactions in p-shell nuclei over a wide range of softening. These
calculations are used to assess convergence properties, extrapolation
techniques, and the dependence of energies, including four-body contributions,
on the SRG resolution scale.


title: On the performance of a hybrid genetic algorithm in dynamic environments

abstract:
  The ability to track the optimum of dynamic environments is important in many
practical applications. In this paper, the capability of a hybrid genetic
algorithm (HGA) to track the optimum in some dynamic environments is
investigated for different functional dimensions, update frequencies, and
displacement strengths in different types of dynamic environments. Experimental
results are reported by using the HGA and some other existing evolutionary
algorithms in the literature. The results show that the HGA has better
capability to track the dynamic optimum than some other existing algorithms.


title: Estimation of oblique structure via penalized likelihood factor analysis

abstract:
  We consider the problem of sparse estimation via a lasso-type penalized
likelihood procedure in a factor analysis model. Typically, the model
estimation is done under the assumption that the common factors are orthogonal
(uncorrelated). However, the lasso-type penalization method based on the
orthogonal model can often estimate a completely different model from that with
the true factor structure when the common factors are correlated. In order to
overcome this problem, we propose to incorporate a factor correlation into the
model, and estimate the factor correlation along with parameters included in
the orthogonal model by maximum penalized likelihood procedure. An entire
solution path is computed by the EM algorithm with coordinate descent, which
permits the application to a wide variety of convex and nonconvex penalties.
The proposed method can provide sufficiently sparse solutions, and be applied
to the data where the number of variables is larger than the number of
observations. Monte Carlo simulations are conducted to investigate the
effectiveness of our modeling strategies. The results show that the lasso-type
penalization based on the orthogonal model cannot often approximate the true
factor structure, whereas our approach performs well in various situations. The
usefulness of the proposed procedure is also illustrated through the analysis
of real data.


title: On the definition of nucleus for dialgebras

abstract:
  Malcev dialgebras have been introduced recently by Bremner, Peresi and
S\'anchez-Ortega. In the present paper, we continue their study by introducing
the notion of the generalized alternative di-nucleus of a 0-dialgebra. A
general conjecture about the speciality of Malcev dialgebras in terms of this
di-nucleus is formulated. In the last section, we introduce the appropriate
generalization of the associative nucleus for dialgebras, and prove an analogue
of Kleinfeld's theorem for the setting of dialgebras.


title:
Bilinear Identities and Hirota's Bilinear Forms for an Extended
  Kadomtsev-Petviashvili Hierarchy

abstract:
  In this paper, we construct the bilinear identities for the wave functions of
an extended Kadomtsev-Petviashvili (KP) hierarchy, which is the KP hierarchy
with particular extended flows (2008, Phys. Lett. A, 372: 3819). By introducing
an auxiliary parameter (denoted by $z$), whose flow corresponds to the
so-called squared eigenfunction symmetry of KP hierarchy, we find the
tau-function for this extended KP hierarchy. It is shown that the bilinear
identities will generate all the Hirota's bilinear equations for the
zero-curvature forms of the extended KP hierarchy, which includes two types of
KP equation with self-consistent sources (KPSCS). It seems that the Hirota's
bilinear equations obtained in this paper for KPSCS are in a simpler form by
comparing with the results by Hu and Wang (2007, Inverse Problems, 23: 1433).


title: An approach to categorification of some small quantum groups II

abstract:
  We categorify an idempotented form of quantum sl2 and some of its simple
representations at a prime root of unity.


title: Broken Dynamic Symmetry and Phase Transition Precursor

abstract:
  Symmetry breaking is a central concept of Landau phase transition theory,
which, however, only considers time-averaged static symmetry of crystal lattice
while neglects dynamic symmetry of lattice vibrations thus fails to explain the
ubiquitous transformation precursor phenomena. We show that incomplete phonon
softening prior to phase transformation leads to dynamic symmetry breaking,
whose natural consequences manifest as various precursor "anomalies" that have
been difficult to understand from traditional theory. Our experimental
observation of heterogeneous phonon domains in high-static-symmetry austenite
phase of thermoelastic Ni-Mn-Ga single crystals before martensitic
transformation by using three-dimensional synchrotron X-ray phonon diffuse
scattering confirms the idea of dynamic symmetry breaking. It provides a
natural mechanism and physical understanding of ubiquitous phase transition
precursor phenomena in metals, alloys and ceramics.


title: Viscous Asymptotically Flat Reissner-Nordstr\"om Black Branes

abstract:
  We study electrically charged asymptotically flat black brane solutions whose
world-volume fields are slowly varying with the coordinates. Using familiar
techniques, we compute the transport coefficients of the fluid dynamic
derivative expansion to first order. We show how the shear and bulk viscosities
are modified in the presence of electric charge and we compute the charge
diffusion constant which is not present for the neutral black p-brane. We
compute the first order dispersion relations of the effective fluid. For small
values of the charge the speed of sound is found to be imaginary and the brane
is thus Gregory-Laflamme unstable as expected. For sufficiently large values of
the charge, the sound mode becomes stable, however, in this regime the
hydrodynamic mode associated with charge diffusion is found to be unstable. The
electrically charged brane is thus found to be (classically) unstable for all
values of the charge density in agreement with general thermodynamic arguments.
Finally, we show that the shear viscosity to entropy bound is saturated, as
expected, while the proposed bounds for the bulk viscosity to entropy can be
violated in certain regimes of the charge of the brane.


title:
Classification and Characterization of Core Grid Protocols for Global
  Grid Computing

abstract:
  Grid computing has attracted many researchers over a few years, and as a
result many new protocols have emerged and also evolved since its inception a
decade ago. Grid protocols play major role in implementing services that
facilitate coordinated resource sharing across diverse organizations. In this
paper, we provide comprehensive coverage of different core Grid protocols that
can be used in Global Grid Computing. We establish the classification of core
Grid protocols into i) Grid network communication and Grid data transfer
protocols, ii) Grid information security protocols, iii) Grid resource
information protocols, iv) Grid management protocols, and v) Grid interface
protocols, depending upon the kind of activities handled by these protocols.
All the classified protocols are also organized into layers of the Hourglass
model of Grid architecture to understand dependency among these protocols. We
also present the characteristics of each protocol. For better understanding of
these protocols, we also discuss applied protocols as examples from either
Globus toolkit or other popular Grid middleware projects. We believe that our
classification and characterization of Grid protocols will enable better
understanding of core Grid protocols and will motivate further research in the
area of Global Grid Computing.


title:
Multipole Gravitational Lensing and High-order Perturbations on the
  Quadrupole Lens

abstract:
  An arbitrary surface mass density of gravitational lens can be decomposed
into multipole components. We simulate the ray-tracing for the multipolar mass
distribution of generalized SIS (Singular Isothermal Sphere) model, based on
the deflection angles which are analytically calculated. The magnification
patterns in the source plane are then derived from inverse shooting technique.
As have been found, the caustics of odd mode lenses are composed of two
overlapping layers for some lens models. When a point source traverses such
kind of overlapping caustics, the image numbers change by \pm 4, rather than
\pm 2. There are two kinds of images for the caustics. One is the critical
curve and the other is the transition locus. It is found that the image number
of the fold is exactly the average value of image numbers on two sides of the
fold, while the image number of the cusp is equal to the smaller one. We also
focus on the magnification patterns of the quadrupole (m = 2) lenses under the
perturbations of m = 3, 4 and 5 mode components, and found that one, two, and
three butterfly or swallowtail singularities can be produced respectively. With
the increasing intensity of the high-order perturbations, the singularities
grow up to bring sixfold image regions. If these perturbations are large enough
to let two or three of the butterflies or swallowtails contact, eightfold or
tenfold image regions can be produced as well. The possible astronomical
applications are discussed.


title: Jordan cells of periodic loop models

abstract:
  Jordan cells in transfer matrices of finite lattice models are a signature of
the logarithmic character of the conformal field theories that appear in their
thermodynamical limit. The transfer matrix of periodic loop models, T_N, is an
element of the periodic Temperley-Lieb algebra EPTL_N(\beta, \alpha), where N
is the number of sites on a section of the cylinder, and \beta = -(q+1/q) = 2
\cos \lambda and \alpha the weights of contractible and non-contractible loops.
The thermodynamic limit of T_N is believed to describe a conformal field theory
of central charge c=1-6\lambda^2/(\pi(\lambda-\pi)). The abstract element T_N
acts naturally on (a sum of) spaces V_N^d, similar to those upon which the
standard modules of the (classical) Temperley-Lieb algebra act. These spaces
known as sectors are labeled by the numbers of defects d and depend on a {\em
twist parameter} v that keeps track of the winding of defects around the
cylinder. Criteria are given for non-trivial Jordan cells of T_N both between
sectors with distinct defect numbers and within a given sector.

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


title:
Input-output equivalence and identifiability: some simple
  generalizations of the differential algebra approach

abstract:
  In this paper, we give an overview of the differential algebra approach to
identifiability, and then note a very simple observation about input-output
equivalence and identifiability, that describes the identifiability equivalence
between input-output equivalent models. We then give several simple
consequences of this observation that can be useful in showing identifiability,
including examining non-first order ODE models, nondimensionalization and
rescaling, model reducibility, and a modular approach to evaluating
identifiability. We also examine how input-output equivalence can allow us to
generate input output equations in the differential algebra approach through a
wider range of methods (e.g. substitution and differential or standard Groebner
basis approaches).


title: Black Hole Binaries and Microquasars

abstract:
  This is a general review on the observations and physics of black hole X-ray
binaries and microquasars, with the emphasize on recent developments in the
high energy regime. The focus is put on understanding the accretion flows and
measuring the parameters of black holes in them. It includes mainly two parts:
(1) Brief review of several recent review article on this subject; (2) Further
development on several topics, including black hole spin measurements, hot
accretion flows, corona formation, state transitions and thermal stability of
standard think disk. This is thus not a regular bottom-up approach, which I
feel not necessary at this stage. Major effort is made in making and
incorporating from many sources useful plots and illustrations, in order to
make this article more comprehensible to non-expert readers. In the end I
attempt to make a unification scheme on the accretion-outflow (wind/jet)
connections of all types of accreting BHs of all accretion rates and all BH
mass scales, and finally provide a brief outlook.


title:
Constraints on spacetime anisotropy and Lorentz violation from the GRAAL
  experiment

abstract:
  The GRAAL experiment could constrain the variations of the speed of light.
The anisotropy of the speed of light may imply that the spacetime is
anisotropic. Finsler geometry is a reasonable candidate to deal with the
spacetime anisotropy. In this paper, the Lorentz invariance violation (LIV) of
the photon sector is investigated in the locally Minkowski spacetime. The
locally Minkowski spacetime is a class of flat Finsler spacetime and refers a
metric with the anisotropic departure from the Minkowski one. The LIV matrices
used to fit the experimental data are represented in terms of these metric
deviations. The GRAAL experiment constrains the spacetime anisotropy to be less
than \(10^{-14}\). In addition, we find that the simplest Finslerian photon
sector could be viewed as a geometric representation of the photon sector in
the minimal standard model extension (SME).


title: Stable phase retrieval with low-redundancy frames

abstract:
  We investigate the recovery of vectors from magnitudes of frame coefficients
when the frames have a low redundancy, meaning a small number of frame vectors
compared to the dimension of the Hilbert space. We first show that for vectors
in d dimensions, 4d-4 suitably chosen frame vectors are sufficient to uniquely
determine each signal, up to an overall unimodular constant, from the
magnitudes of its frame coefficients. Then we discuss the effect of noise and
show that 8d-4 frame vectors provide a stable recovery if part of the frame
coefficients is bounded away from zero. In this regime, perturbing the
magnitudes of the frame coefficients by noise that is sufficiently small
results in a recovery error that is at most proportional to the noise level.


title: Fabrication of whispering gallery mode cavity using crystal growth

abstract:
  We developed a new method for fabricating crystalline whispering gallery mode
cavities based on laser-heated pedestal growth. We fabricated sapphire cavities
and obtained a Q factor of 16000 with a cavity whose diameter was about 240 um.
We showed numerically that the cross-sectional shape of the cavity is sensitive
to the cavity Q, and we controlled it successfully by changing the growth
condition in the molten zone, without significantly degrading the crystal
structure.


title:
Nano-Optical Device Design with the Use of Open-Source Parallel Version
  FDTD and Commercial Finite Element Package

abstract:
  In this paper, the implementation of open-source parallel-version FDTD
(Finite-Difference-Time-Domain) software, MEEP, on Texas A&M supercomputers and
commercial finite element package, COMSOL, on a single workstation for the
design design of nano-optical device is reported. The the computer architecture
and performance of both numerical methods on the same design will be briefly
described.


title:
Computer Interaction and the Benefits of Social Networking for People
  with Borderline Personality Disorder: Enlightening Mental Health
  Professionals

abstract:
  This paper seeks to present the findings of a focus group and questionnaire
in assessing how aware mental health professionals, who have experience with
people with Borderline Personality Disorder (BPD), are in the extent of ICT
based support for people with BPD. The methods used were both qualitative and
quantitative and used descriptive data. Content analysis was used to explore
specific themes and results were cross-examined between the two methods. The
work should be viewed as an exploratory study into the viability and likely
acceptance of a virtual support community specifically designed for people with
BPD. The long term aim is to provide additional support for people with BPD,
especially when they are in crisis and might be at a higher risk of harm.


title:
Implications for Improving Accessibility to E-Commerce Websites in
  Developing Countries - A Study of Hotel Websites

abstract:
  This research explores the accessibility issues with regard to the e-commerce
websites in developing countries, through a study of Sri Lankan hotel websites.
A web survey and a web content analysis were conducted as the methods to elicit
data on web accessibility. Factors preventing accessibility were hypothesized
as an initial experiment. Affecting design elements are identified through web
content analysis, the results of which are utilized to develop specific
implications for improving web accessibility. The hypothesis tests show that
there is no significant correlation between accessibility and geographical or
economic factors. However, physical impairments of users have a considerable
influence on the accessibility of web page user interface if it has been
designed without full consideration of the needs of all users. Especially,
visual and mobility impaired users experience poor accessibility. Poor
readability and less navigable page designs are two observable issues, which
pose threats to accessibility. The lack of conformance to W3C accessibility
guidelines and the poor design process are the specific shortcomings which
reduce the overall accessibility. Guidelines aim to improve the accessibility
of sites with a strategic focus. Further enhancements are suggested with
adherence to principles, user centered design and developing customizable web
portals compatible for connections with differing speeds. Re-ordering search
results has been suggested as one of the finest step towards making the web
content accessible for users with differing needs. A need for developing new
design models for differencing user groups and implementing web accessibility
strategy are emphasized as vital steps towards effective information
dissemination via e-commerce websites in the developing countries.


title: Fidelity in topological superconductors with end Majorana fermions

abstract:
  Fidelity and fidelity susceptibility are introduced to investigate the
topological superconductors with end Majorana fermions. A general formalism is
established to calculate the fidelity and fidelity susceptibility by solving
Bogoliubov-de Gennes equations. It is shown that the fidelity susceptibility
manifest itself as a peak at the topological quantum phase transition point for
homogeneous Kitaev wire, thus serves as a valid indicator for the topological
quantum phase transition which signals the appearance of Majorana fermions. The
effect of disorders is investigated within this formalism. We consider three
disordered systems and observe fidelity susceptibility peak in all of them. By
analyzing the susceptibility peak, we notice that the local potential disorders
and the hopping disorders can shift the phase transition point, while
off-diagonal disorders have no obvious influence. Our results confirm that the
existence of topological quantum phase transition is robust to these disorders,
while the behavior of the phase transition might be influenced by disorders.


title:
Modeling and Testing for Joint Association Using a Genetic Random Field
  Model

abstract:
  Substantial progress has been made in identifying single genetic variants
predisposing to common complex diseases. Nonetheless, the genetic etiology of
human diseases remains largely unknown. Human complex diseases are likely
influenced by the joint effect of a large number of genetic variants instead of
a single variant. The joint analysis of multiple genetic variants considering
linkage disequilibrium (LD) and potential interactions can further enhance the
discovery process, leading to the identification of new disease-susceptibility
genetic variants. Motivated by the recent development in spatial statistics, we
propose a new statistical model based on the random field theory, referred to
as a genetic random field model (GenRF), for joint association analysis with
the consideration of possible gene-gene interactions and LD. Using a
pseudo-likelihood approach, a GenRF test for the joint association of multiple
genetic variants is developed, which has the following advantages: 1.
considering complex interactions for improved performance; 2. natural dimension
reduction; 3. boosting power in the presence of LD; 4. computationally
efficient. Simulation studies are conducted under various scenarios. Compared
with a commonly adopted kernel machine approach, SKAT, GenRF shows overall
comparable performance and better performance in the presence of complex
interactions. The method is further illustrated by an application to the Dallas
Heart Study.


title:
Superfluidity of fermion atoms loaded in a deep optical lattice: the
  existence of two rotonlike modes

abstract:
  We present theoretical calculations of collective modes of the one-band
attractive Hubbard model which is widely used to study the s-wave superfluid
phases of atomic Fermi gases of two-hyperfine states loaded in a deep optical
lattice. To make our theory applicable for both superconductivity and
superfluidity, we assume the more general $t-U-J$ Hamiltonian.
  Using the functional differentiation we derive Schwinger-Dyson equations for
the single-particle Green's functions.
  The method of Legendre transform is used to give a systematic derivation of
the Bethe-Salpeter (BS) equation for the two-particle Green's function and the
associated collective modes. The numerical solution of the BS equation in the
limit $J\rightarrow 0$ shows the existence of two rotonlike collective modes
with different low-energy Goldstone dispersions and different positions of the
rotonlike minima. The two rotonlike modes lie outside of the region determined
by the lower boundary of the particle-hole continuum, and therefore, the two
modes are not damped and they should be experimentally observable.
  In the presence of superfluid flow at a certain critical flow momentum, the
minimum of the first rotonlike mode reaches zero energy, but this occurs before
the minimum of the second mode and the lower boundary of the particle-hole
continuum do, i.e. there are two critical flow momenta related to the existence
of two rotonlike excitations.


title:
Looking back at Facebook content and the positive impact upon wellbeing:
  Exploring reminiscing as a tool for self soothing

abstract:
  The premise of this paper is to explore the potential of reminiscing in
facilitating self soothing. The research presented looks at people's activities
on Facebook and whether these particular activities impact upon their perceived
sense of wellbeing, furthermore, whether specific Facebook activities enable a
self-soothing effect when feeling low in mood. A survey was distributed amongst
Facebook users. The results from the study appear to indicate that in
comparison to other Facebook activities, looking back upon photos and wall
posts in particular, could have a positive impact upon wellbeing. Additionally,
the results indicate that people who have mental health problems, experience a
more positive impact upon their wellbeing when looking at photos and wall
posts, than those who did not have a history of mental health issues. The
results from the research presented here contribute towards the viability of
developing a mobile application to facilitate positive reminiscing


title:
Resonant Excitation of Disk Oscillations in Deformed Disks VI: Stability
  Criterion Revisited

abstract:
  We re-examine excitation of a set of disk oscillations in a deformed disk by
a resonant process. We assume that the disk is deformed from an axisymmetric
steady state by an oscillatory deformation with frequency $\omega_{\rm D}$ and
azimuthal wavenumber $m_{\rm D}$. Then, we consider two normal mode
oscillations with a set of frequencies and azimuthal wavenumber being
($\omega_1$, $m_1$) and ($\omega_2$, $m_2$) and satisfying the resonant
conditions ($\omega_1+\omega_2+\omega_{\rm D}=0$ and $m_1+m_2+m_{\rm D}=0$).
These oscillations are resonantly excited if $(E_1/\omega_1)(E_2/\omega_2)>0$,
where $E_1$ and $E_2$ are wave energies of the above two oscillations, when the
deformation is maintained by external forces or has a large amplitude compared
with the oscillations. This instability condition is rather general as long as
unperturbed density and pressure vanish on the surface of the system.
Possibility of application to superhump and negative superhump in superoutburst
state of dwarf novae are briefly discussed.


title:
HCI considerations in Designing a Second Life Virtual Therapeutic
  Community for the Support & Treatment of People with Borderline Personality
  Disorder

abstract:
  This paper aims to present the current position of the ongoing research into
developing the requirements and acceptance of a virtual therapeutic community
in Second Life, specifically for people with Borderline Personality Disorder
(BPD). The research has identified this particular user group given that people
with BPD often require high levels of support, which can result in emergency
hospital admissions, in addition to the significant economic cost of treating
people BPD in relation to other mental illnesses (NCCMH, 2009). The research is
also intended to be used as framework for other mental health conditions. This
work is a continuation of the research carried out in exploring the potential
of virtual therapeutic communities based on existing models of therapeutic
hospitals as well as virtual treatments and support, in treating people with
BPD. An interdisciplinary approach to this research features collaboration from
areas in HCI, forensic psychology and psychotherapy.


title:
On the Coulomb and Higgs branch formulae for multi-centered black holes
  and quiver invariants

abstract:
  In previous work we have shown that the equivariant index of multi-centered
N=2 black holes localizes on collinear configurations along a fixed axis. Here
we provide a general algorithm for enumerating such collinear configurations
and computing their contribution to the index. We apply this machinery to the
case of black holes described by quiver quantum mechanics, and give a
systematic prescription -- the Coulomb branch formula -- for computing the
cohomology of the moduli space of quiver representations. For quivers without
oriented loops, the Coulomb branch formula is shown to agree with the Higgs
branch formula based on Reineke's result for stack invariants, even when the
dimension vector is not primitive. For quivers with oriented loops, the Coulomb
branch formula parametrizes the Poincar\'e polynomial of the quiver moduli
space in terms of single-centered (or pure-Higgs) BPS invariants, which are
conjecturally independent of the stability condition (i.e. the choice of
Fayet-Iliopoulos parameters) and angular-momentum free. To facilitate further
investigation we provide a Mathematica package "CoulombHiggs.m" implementing
the Coulomb and Higgs branch formulae.


title:
A Review into eHealth Services and Therapies: Potential for Virtual
  Therapeutic Communities - Supporting People with Severe Personality Disorder

abstract:
  eHealth has expanded hugely over the last fifteen years and continues to
evolve, providing greater benefits for patients, health care professionals and
providers alike. The technologies that support these systems have become
increasingly more sophisticated and have progressed significantly from standard
databases, used for patient records, to highly advanced Virtual Reality (VR)
systems for the treatment of complex mental health illnesses. The scope of this
paper is to initially explore e-Health, particularly in relation to
technologies supporting the treatment and management of wellbeing in mental
health. It then provides a case study of how technology in e-Health can lend
itself to an application that could support and maintain the wellbeing of
people with a severe mental illness. The case study uses Borderline Personality
Disorder as an example, but could be applicable in many other areas, including
depression, anxiety, addiction and PTSD. This type of application demonstrates
how e-Health can empower the individuals using it but also potentially reducing
the impact upon health care providers and services.


title: Spectral Variation of NLS1 Galaxy PMN J0948+0022

abstract:
  Four well-sampled spectral energy distributions (SEDs) of PMN J0948+0022 are
fitted with the syn+SSC+EC model to derive the physical parameters of its jets
and to investigate the spectral variations of its SEDs. A tentative correlation
between the peak luminosity L_c and peak frequency nu_c of its inverse Compton
(IC) bump is found in both the observer and co-moving frames, indicating that
the variations of luminosity are accompanied with the spectral shift. A
correlation between L_c and delta is found, and thus the magnification of the
external photon field by the bulk motion of the radiation regions is an
essential reason for the spectral variation since the IC bump of PMN J0948+0022
is dominated by the EC process.


title: Universal central extensions in semi-abelian categories

abstract:
  Basing ourselves on Janelidze and Kelly's general notion of central
extension, we study universal central extensions in the context of semi-abelian
categories. We consider a new fundamental condition on composition of central
extensions and give examples of categories which do, or do not, satisfy this
condition.


title: LFTL: A multi-threaded FTL for a Parallel IO Flash Card under Linux

abstract:
  New PCI-e flash cards and SSDs supporting over 100,000 IOPs are now
available, with several usecases in the design of a high performance storage
system. By using an array of flash chips, arranged in multiple banks, large
capacities are achieved. Such multi-banked architecture allow parallel read,
write and erase operations. In a raw PCI-e flash card, such parallelism is
directly available to the software layer. In addition, the devices have
restrictions such as, pages within a block can only be written sequentially.
The devices also have larger minimum write sizes (greater than 4KB). Current
flash translation layers (FTLs) in Linux are not well suited for such devices
due to the high device speeds, architectural restrictions as well as other
factors such as high lock contention. We present a FTL for Linux that takes
into account the hardware restrictions, that also exploits the parallelism to
achieve high speeds. We also consider leveraging the parallelism for garbage
collection by scheduling the garbage collection activities on idle banks. We
propose and evaluate an adaptive method to vary the amount of garbage
collection according to the current I/O load on the device.


title: Transversals of Longest Paths and Cycles

abstract:
  Let G be a graph of order n. Let lpt(G) be the minimum cardinality of a set X
of vertices of G such that X intersects every longest path of G and define
lct(G) analogously for cycles instead of paths. We prove that lpt(G) \leq
ceiling(n/4-n^{2/3}/90), if G is connected, lct(G) \leq
ceiling(n/3-n^{2/3}/36), if G is 2-connected, and \lpt(G) \leq 3, if G is a
connected circular arc graph. Our bound on lct(G) improves an earlier result of
Thomassen and our bound for circular arc graphs relates to an earlier statement
of Balister \emph{et al.} the argument of which contains a gap. Furthermore, we
prove upper bounds on lpt(G) for planar graphs and graphs of bounded
tree-width.


title: Skyrmion crystals in the pseudo-spin-1/2 Bose-Einstein condensates

abstract:
  Exact two-dimensional solutions are constructed for the pseudo-spin-1/2
Bose-Einstein condensates which are described by the coupled nonlinear
Gross-Pitaevskii equations where the intraspecies and interspecies coupling
constants are assumed to be equal. The equations are decoupled by means of
re-combinations of the nonlinear terms of the hyperfine states according to the
spatial dimensions. These stationary solutions form various spin textures which
are identified as skyrmion crystals. In a special case, the crystal of
skyrmion-antiskyrmion pairs is formed in the soliton limit.


title:
Verification and comparison of four numerical schemes for a 1D
  viscoelastic blood flow model

abstract:
  A reliable and fast numerical scheme is crucial for the 1D simulation of
blood flow in compliant vessels. In this paper, a 1D blood flow model is
incorporated with a Kelvin-Voigt viscoelastic arterial wall. This leads to a
nonlinear hyperbolic-parabolic system, which is then solved with four numerical
schemes, namely: MacCormack, Taylor-Galerkin, MUSCL (monotonic upwind scheme
for conservation law) and local discontinuous Galerkin. The numerical schemes
are tested on a single vessel, a simple bifurcation and a network with 55
arteries. The numerical solutions are checked favorably against analytical,
semi-analytical solutions or clinical observations. Among the numerical
schemes, comparisons are made in four important aspects: accuracy, ability to
capture shock-like phenomena, computational speed and implementation
complexity. The suitable conditions for the application of each scheme are
discussed.


title: On the endomorphisms of some sheaves of functions

abstract:
  Given a $C^\infty$ real manifold $X$ and $\mathcal{C}^m_X$ its sheaf of
$m$-times differentiable real-valued functions, we prove that the sheaf
$\mathcal{D}^{m, r}_X$ of differential operators of order $\leq m$ with
coefficient functions of class $C^r$ can be obtained in terms of the sheaf
$\mathcal{H}om_{\mathbb{R}_X}(\mathcal{C}^m_X, \mathcal{C}^r_X)$ of morphisms
of $\mathcal{C}^m_X$ into $\mathcal{C}^r_X$. The superscripts $m$ and $r$ are
integers.


title: SOAP3-dp: Fast, Accurate and Sensitive GPU-based Short Read Aligner

abstract:
  To tackle the exponentially increasing throughput of Next-Generation
Sequencing (NGS), most of the existing short-read aligners can be configured to
favor speed in trade of accuracy and sensitivity. SOAP3-dp, through leveraging
the computational power of both CPU and GPU with optimized algorithms, delivers
high speed and sensitivity simultaneously. Compared with widely adopted
aligners including BWA, Bowtie2, SeqAlto, GEM and GPU-based aligners including
BarraCUDA and CUSHAW, SOAP3-dp is two to tens of times faster, while
maintaining the highest sensitivity and lowest false discovery rate (FDR) on
Illumina reads with different lengths. Transcending its predecessor SOAP3,
which does not allow gapped alignment, SOAP3-dp by default tolerates alignment
similarity as low as 60 percent. Real data evaluation using human genome
demonstrates SOAP3-dp's power to enable more authentic variants and longer
Indels to be discovered. Fosmid sequencing shows a 9.1 percent FDR on newly
discovered deletions. SOAP3-dp natively supports BAM file format and provides a
scoring scheme same as BWA, which enables it to be integrated into existing
analysis pipelines. SOAP3-dp has been deployed on Amazon-EC2, NIH-Biowulf and
Tianhe-1A.


title: Ionospheric HF radio propagation in problems and computer assignments

abstract:
  The book's purpose is to introduce the HF ionospheric radio-propagation,
through the solution of problems and computer assignments. The problems and
computer assignments are used primarily as a check and deepening of the
theoretical part, which however is essential. Secondly, they are used to
introduce the reader to new subjects in a natural way. The text proposes the
main objective of bringing the reader which has a background similar to a
master degree in physics or engineering, to an operative level in the field of
ionospheric radio-propagation. The material covers the fundamentals of plasma
physics, the Appleton-Hartree equation, its interpretation and discussion, and
group refractive indices. The applications presented include ionograms
simulation, ray tracing, and ionospheric absorption.


title: Coexistence of diffusive and ballistic transport in a simple spin ladder

abstract:
  We show that in a nonintegrable spin ladder system with the XX type of
coupling along the legs and the XXZ type along the rungs there are invariant
subspaces that support ballistic magnetization transport. In the complementary
subspace the transport is found to be diffusive. This shows that (i) quantum
chaotic systems can possess ballistic subspaces, and (ii) diffusive and
ballistic transport modes can coexist in a rather simple nonintegrable model.
In the limit of an infinite anisotropy in rungs the system studied is
equivalent to the one-dimensional Hubbard model.


title: HST/COS observations of a new population of associated QSO absorbers

abstract:
  (Abridged) We present a sample of new population of associated absorbers,
detected through Ne VIII \lambda\lambda 770,780 absorption, in HST/COS spectra
of intermediate redshift (0.45 < z < 1.21) quasars (QSOs). Our sample comprised
of total 12 associated Ne VIII systems detected towards 8 lines of sight (none
of them are radio bright). The incidence rate of these absorbers is found to be
40%. Majority of the Ne VIII systems at small ejection velocities (v_ej) show
complete coverage of the background source, but systems with higher v_ej show
lower covering fractions (i.e. f_c < 0.8) and systematically higher values of
N(Ne VIII). We detect Mg X \lambda\lambda 609,624 absorption in 7 out of the 8
Ne VIII systems where the expected wavelength range is cover by our spectra and
is free of any strong blending. We report the detections of Na IX
\lambda\lambda 681,694 absorption, for the first time, in three highest
ejection velocity (e.g. v_ej > 7,000 km/s) systems in our sample. All these
systems show very high N(Ne VIII) (i.e. > 10^{15.6} cm^{-2}), high ionization
parameter (i.e. log U > 0.5), high metallicity (i.e. Z > Z_{\odot}), and
ionization potential dependent f_c values. The observed column density ratios
of different ions are reproduced by multiphase photoionization (PI) and/or
collisional ionization (CI) equilibrium models. While solar abundance ratios
are adequate in CIE, enhancement of Na relative to Mg is required in PI models
to explain our observations.


title:
Perangkat lunak bantu mengenal huruf arab melayu ke bentuk huruf latin
  bahasa Indonesia

abstract:
  The development of computer science has contributed greatly for increasing of
efficiency and effectively. Many areas are covered by computer science,
included education. The purpose of this research is to introduce jawi a type of
Indonesian letters. Jawis letter is one of the most popular letter in the past.
But right now few people can read and understand it. Many documents in the past
was written in Jawi. The writer develop or build the software using Pressman
method, and tools such as Microsoft Visual Basic, and Microsoft Access. This
software can introduce Jawi then people can learn it easily.


title: Nielsen zeta functions for maps on infra-nilmanifolds are rational

abstract:
  In this paper we will show that for any map $f$ on an infra-nilmanifold, the
Nielsen number $N(f)$ of this map is either equal to $|L(f)|$, where $L(f)$ is
the Lefschetz number of that map, or equal to the expression $|L(f)-L(f_+)|$,
where $f_+$ is a lift of $f$ to a 2-fold covering of that infra-nilmanifold. By
exploiting the exact nature of this relationship for all powers of $f$, we
prove that the Nielsen dynamical zeta function for a map on an
infra-nilmanifold is always a rational function.


title: Granular transport in a horizontally vibrated sawtooth channel

abstract:
  We present a new mode of transport of spherical particles in a horizontally
vibrated channel with sawtooth shaped side walls. The underlying driving
mechanism is based on an interplay of directional energy injection transformed
by the sidewall collisions and density dependent interparticle collisions.
Experiments and matching numerics show that the average particle velocity
reaches a maximum at 60% of the maximal filling density. Introducing a spatial
phase shift between the channel boundaries increases the transport velocity by
an order of magnitude.


title: Blind Estimation of Primary User Traffic Parameters Under Sensing Errors

abstract:
  In this work we investigate the bounds on the estimation accuracy of Primary
User (PU) traffic parameters with exponentially distributed busy and idle
times. We derive closed-form expressions for the Cramer-Rao bounds on the mean
squared estimation error for the blind joint estimation of the PU traffic
parameters, specifically, the duty cycle, and the mean arrival and departure
rates. Moreover, we present the corresponding maximum-likelihood estimators for
the traffic parameters. In addition, we derive a modified likelihood function
for the joint estimation of traffic parameters when spectrum sensing errors are
considered, and we present the impact of spectrum sensing errors on the
estimation error via simulations. Finally, we consider a duty cycle estimator,
common in traffic estimation literature, that is based on averaging the traffic
samples. We derive, in closed-form, the mean squared estimation error of the
considered estimator under spectrum sensing errors.


title:
Gauge-covariant canonical formalism revisited with application to the
  proton spin decomposition

abstract:
  We revisit the gauge-covariant canonical formalism by separating explicitly
physical and gauge degrees of freedom. We show in particular that the
gauge-invariant linear and angular momentum operators proposed by Chen et al.
can consistently be derived from the standard procedure based on the Noether's
theorem. Finally, we demonstrate that this approach is essentially equivalent
to the gauge-invariant canonical formalism based on the concept of Dirac
variables. Because of many similarities with the background field method, the
formalism developed here should also be relevant to general relativity and any
metric theories.


title:
Spectral features of Earth-like planets and their detectability at
  different orbital distances around F, G, and K-type stars

abstract:
  We investigate the spectral appearance of Earth-like exoplanets in the HZ of
different main sequence stars at different orbital distances. We furthermore
discuss for which of these scenarios biomarker absorption bands may be detected
during primary or secondary transit with near-future telescopes and
instruments.We analyze the spectra taking into account different filter
bandpasses of two photometric instruments planned to be mounted to the JWST. We
analyze in which filters and for which scenarios molecular absorption bands are
detectable when using the space-borne JWST or the ground-based telescope E-ELT.
Absorption bands of CO2, H2O, CH4 and O3 are clearly visible in high-resolution
spectra as well as in the filters of photometric instruments. However, only
during primary eclipse bands of CO2, H2O and O3 are detectable for all
scenarios when using photometric instruments and an E-ELT telescope setup. CH4
is only detectable at the outer HZ of the K star since here the atmospheric
modeling results in very high abundances. Since the detectable CO2 and H2O
bands overlap, separate bands need to be observed to prove their existence in
the atmosphere. In order to detect H2O in a separate band, a S/N>7 needs to be
achieved for E-ELT observations, e.g. by co-adding at least 10 transit
observations. Using a spaceborne telescope like the JWST enables the detection
of CO2 at 4.3mu, which is not possible for ground-based observations due to the
Earth's atmospheric absorption. Hence combining observations of spaceborne and
groundbased telescopes might allow to detect the presence of the biomarker
molecule O3 and the related compounds H2O and CO2 in a planetary atmosphere.
Other absorption bands using the JWST can only be detected for much higher
S/Ns, which is not achievable by just co-adding transit observations since this
would be far beyond the planned mission time of JWST.(abridged)


title:
Entanglement Spectra and Entanglement Thermodynamics of Hofstadter
  Bilayers

abstract:
  We study Hofstadter bilayers, i.e. coupled hopping models on two-dimensional
square lattices in a perpendicular magnetic field. Upon tracing out one of the
layers, we find an explicit expression for the resulting entanglement spectrum
in terms of the energy eigenvalues of the underlying monolayer system. For
strongly coupled layers the entanglement Hamiltonian is proportional to the
energetic Hamiltonian of the monolayer system. The proportionality factor,
however, cannot be interpreted as the inverse thermodynamic temperature, but
represents a phenomenological temperature scale. We derive an explicit relation
between both temperature scales which is in close analogy to a standard result
of classic thermodynamics. In the limit of vanishing temperature, thermodynamic
quantities such as entropy and inner energy approach their ground-state values,
but show a fractal structure as a function of magnetic flux.


title: Locally Repairable Codes with Multiple Repair Alternatives

abstract:
  Distributed storage systems need to store data redundantly in order to
provide some fault-tolerance and guarantee system reliability. Different coding
techniques have been proposed to provide the required redundancy more
efficiently than traditional replication schemes. However, compared to
replication, coding techniques are less efficient for repairing lost
redundancy, as they require retrieval of larger amounts of data from larger
subsets of storage nodes. To mitigate these problems, several recent works have
presented locally repairable codes designed to minimize the repair traffic and
the number of nodes involved per repair. Unfortunately, existing methods often
lead to codes where there is only one subset of nodes able to repair a piece of
lost data, limiting the local repairability to the availability of the nodes in
this subset. In this paper, we present a new family of locally repairable codes
that allows different trade-offs between the number of contacted nodes per
repair, and the number of different subsets of nodes that enable this repair.
We show that slightly increasing the number of contacted nodes per repair
allows to have repair alternatives, which in turn increases the probability of
being able to perform efficient repairs. Finally, we present pg-BLRC, an
explicit construction of locally repairable codes with multiple repair
alternatives, constructed from partial geometries, in particular from
Generalized Quadrangles. We show how these codes can achieve practical lengths
and high rates, while requiring a small number of nodes per repair, and
providing multiple repair alternatives.


title: Uniform hyperbolicity of the curve graph via surgery sequences

abstract:
  We prove that the curve graph $\calC^{(1)}(S)$ is Gromov-hyperbolic with a
constant of hyperbolicity independent of the surface $S$. The proof is based on
the proof of hyperbolicity of the free splitting complex by Handel and Mosher,
as interpreted by Hilion and Horbez.


title:
The last three outbursts of H 1743-322 observed by RXTE in its latest
  service phase

abstract:
  After 2010, three outbursts of H 1743-322 were detected by RXTE. We have
carried out timing and spectral analysis of the data, emphasizing on the two
with relatively complete evolution history presented in the RXTE/PCA
observations. We then constitute an enlarged outburst sample for H 1743-322
which allows to investigate the spectral transitions in more details. We find
that the spectral transitions to high-soft state constrain a region for four
outbursts in hardness-intensity diagram. An extension of the region locates in
the vicinity of the failed outburst in 2008, and excludes it from a successful
group. We therefore suggest the failed outburst in 2008 may present the first
almost successful outburst sample, which is important for modelling the
outburst, especially upon the conditions required for transition to high-soft
state.


title:
Towards Python-based Domain-specific Languages for Self-reconfigurable
  Modular Robotics Research

abstract:
  This paper explores the role of operating system and high-level languages in
the development of software and domain-specific languages (DSLs) for
self-reconfigurable robotics. We review some of the current trends in
self-reconfigurable robotics and describe the development of a software system
for ATRON II which utilizes Linux and Python to significantly improve software
abstraction and portability while providing some basic features which could
prove useful when using Python, either stand-alone or via a DSL, on a
self-reconfigurable robot system. These features include transparent socket
communication, module identification, easy software transfer and reliable
module-to-module communication. The end result is a software platform for
modular robots that where appropriate builds on existing work in operating
systems, virtual machines, middleware and high-level languages.


title:
Strangeness in proton and properties of nucleons in nuclear matter
  revisited

abstract:
  The properties of the nucleons in nuclear medium have been investigated in
the context of the flux tube model incorporating strangeness $(s\bar{s})$
contribution to proton structure in conformity with the experimental
indication. Proton is described as a pentaquark system with strange quark
contribution whereas neutron is described in three quark configuration. The
Quasi particle model of diquark is used to describe the structures of the
nucleons. Modifications of the properties like swelling, mass,
incompressibility, ratio of the structure functions
($\frac{F_{2}^{n}(x)}{F_{2}^{p}(x)}$), Gottfried Sum rule for nucleons in
nuclear medium have been studied and significant effects have been observed. It
has been suggested that the change of the size degree of freedom of the nucleon
in the nuclear medium plays an important role in describing the properties in
medium. The results are discussed in detail and compared with existing
experimental and theoretical predictions. Some interesting observations are
made.


title:
Existence of capillary-gravity water waves with piecewise constant
  vorticity

abstract:
  In this paper we construct periodic capillarity-gravity water waves with a
piecewise constant vorticity distribution. They describe water waves traveling
on superposed linearly sheared currents that have different vorticities. This
is achieved by associating to the height function formulation of the water wave
problem a diffraction problem where we impose suitable transmission conditions
on each line where the vorticity function has a jump. The solutions of the
diffraction problem, found by using local bifurcation theory, are the desired
solutions of the hydrodynamical problem.


title:
Z2 Topological insulator of ultra cold atoms in bichromatic optical
  lattices

abstract:
  We investigate the effect of a strong bichromatic deformation to the
$\mathbb{Z}_{2}$ topological insulator in a fermionic ultracold atomic system
proposed by B. B\'eri and N. R. Cooper, Phys.Rev.Lett. {\bf 107}, 145301
(2011). Large insulating gap of this system allows for examination of strong
perturbations. We consider bichromatic perturbation along all axes on a
triangular optical lattice. We find that $\mathbb{Z}_{2}$ topological character
of the system is robust up to a certain depth of the deformation. The lowest
band can become topologically trivial while the lowest two bands are always
protected.


title: CRDB: a database of charged cosmic rays

abstract:
  This paper gives a description of a new on-line database
http://lpsc.in2p3.fr/crdb and associated on-line tools (data selection, data
export, plots, etc.) for charged cosmic-ray measurements. The experimental
setups (type, flight dates, techniques) from which the data originate are
included in the database, along with the references to all relevant
publications. The database relies on the MySQL5 engine. The web pages and
queries are based on PHP, AJAX and the jquery, jquery.cluetip, jquery-ui, and
table-sorter third-party libraries. In this first release, we restrict
ourselves to Galactic cosmic rays with Z<=30 and a kinetic energy per nucleon
up to a few tens of TeV/n. This corresponds to more than 200 different
sub-experiments (i.e., different experiments, or data from the same experiment
flying at different times) in as many publications. We set up a cosmic-ray
database and provide tools to sort and visualise the data. New data can be
submitted, providing the community with a collaborative tool to archive past
and future cosmic-ray measurements. Any help/ideas to further expand and/or
complement the database is welcome (please contact crdatabase@lpsc.in2p3.fr).


title:
Stochastic dynamics of lexicon learning in an uncertain and nonuniform
  world

abstract:
  We study the time taken by a language learner to correctly identify the
meaning of all words in a lexicon under conditions where many plausible
meanings can be inferred whenever a word is uttered. We show that the most
basic form of cross-situational learning - whereby information from multiple
episodes is combined to eliminate incorrect meanings - can perform badly when
words are learned independently and meanings are drawn from a nonuniform
distribution. If learners further assume that no two words share a common
meaning, we find a phase transition between a maximally-efficient learning
regime, where the learning time is reduced to the shortest it can possibly be,
and a partially-efficient regime where incorrect candidate meanings for words
persist at late times. We obtain exact results for the word-learning process
through an equivalence to a statistical mechanical problem of enumerating loops
in the space of word-meaning mappings.

categories: physics.soc-ph cond-mat.stat-mech cs.CL q-bio.NC


title:
Local cubic vertex functions for three massless higher even spin fields
  on spaces AdS_D: An analytic approach

abstract:
  Local cubic vertex functions of three higher even spin fields on AdS_D are
constructed from the Green function of three conserved currents that are dual
to the higher spin fields. Conservation of the currents implies lowest order
gauge invariance. These vertex functions appear by the UV divergence as the
residue of the highest order pole in the dimensional regularization parameter
\epsilon. The method works for even D and maintains covariance at any step. The
resulting formula is quite concise.


title: Independent confirmation of {\beta} Pictoris b imaging with NICI

abstract:
  Context. {\beta} Pictoris b is one of the most studied objects nowadays since
it was identified with VLT/NaCo as a bona-fide exoplanet with a mass of about 9
times that of Jupiter at an orbital separation of 8-9 AU. The link between the
planet and the dusty disk is unambiguously attested and this system provides an
opportunity to study the disk/planet interactions and to constrain formation
and evolutionary models of gas giant planets. Still, {\beta} Pictoris b had
never been confirmed with other telescopes so far. Aims. We aimed at an
independent confirmation using a different instrument. Methods. We retrieved
archive images from Gemini South obtained with the instrument NICI, which is
designed for high contrast imaging. The observations combine coronagraphy and
angular differential imaging and were obtained at three epochs in Nov. 2008,
Dec. 2009 and Dec. 2010. Results. We report the detection with NICI of the
planet {\beta} Pictoris b in Dec. 2010 images at a separation of 404 \pm 10 mas
and P A = 212.1 \pm 0.7{\deg} . It is the first time this planet is observed
with a telescope different than the VLT.


title:
The heat equation under linear conditions on the moments in higher
  dimensions

abstract:
  We consider the heat equation on the $N$-dimensional cube $(0,1)^N$ and
impose different classes of integral conditions, instead of usual boundary
ones. Well-posedness results for the heat equation under the condition that the
moments of order 0 and 1 are conserved had been known so far only in the case
of N=1 -- for which such conditions can be easily interpreted as conservation
of mass and barycenter. In this paper we show that in the case of general $N$
the heat equation with such integral conditions is still well-posed, upon
suitably relax the notion of solution.
  Existence and uniqueness of solutions with general initial data in a suitable
space of distibutions over $(0,1)^N$ are proved by introducing two appropriate
realizations of the Laplacian and checking by form methods that they generate
analytic semigroups. The solution thus obtained does however solve the heat
equation only in a certain distributional sense.
  However, it turns out that one of these realizations is tightly related to a
well-known object of operator theory, the Krein--von Neumann extension of the
Laplacian. This connection also establishes well-posedness in a classical
sense, as long as the initial data are $L^2$-functions.


title: Electrically charged dilaton black holes in external magnetic field

abstract:
  In the present paper we construct a new solution to the
Einstein-Maxwell-dilaton gravity equations describing electrically charged
dilaton black holes immersed in a strong external magnetic field and we study
its properties. The black holes described by the solution are rotating but with
zero total angular momentum and possess an ergoregion confined in a
neighborhood of the horizon. Our results also show that the external magnetic
field does not affect the black hole thermodynamics.


title:
Positive Solution of Singular BVPs for System of Dynamic Equations on
  Time Scales

abstract:
  This paper is devoted to derive some necessary and suficient conditions for
the existence of positive solutions to a singular second order system of
dynamic equations with Dirichlet boundary conditions. The results are obtained
by employing the fixed-point theorems and the method of the lower and upper
solutions.


title:
Free Collisions in a Microgravity Many-Particle Experiment III: The
  Collision Behavior of sub-Millimeter-Sized Dust Aggregates

abstract:
  We conducted micro-gravity experiments to study the outcome of collisions
between sub-mm-sized dust agglomerates consisting of \mu m-sized SiO2 monomer
grains at velocities of several cm/s. Prior to the experiments, we used X-ray
computer tomography (nano-CT) imaging to study the internal structure of these
dust agglomerates and found no rim compaction so that their collision behavior
is not governed by preparation-caused artefacts. We found that collisions
between these dust aggregates can lead either to sticking or to bouncing,
depending mostly on the impact velocity. While previous collision models
derived the transition between both regimes from contact physics, we used the
available empirical data from these and earlier experiments to derive a power
law relation between dust-aggregate mass and impact velocity for the threshold
between the two collision outcomes. In agreement with earlier experiments, we
show that the transition between both regimes is not sharp, but follows a
shallower power law than predicted by previous models (G\"uttler et al. 2010).
Furthermore, we find that sticking between dust aggregates can lead to the
formation of larger structures. Collisions between aggregates-of-aggregates can
lead to growth at higher velocities than homogeneous dust agglomerates.


title:
Ballistic charge transport in graphene and light propagation in periodic
  dielectric structures with metamaterials: a comparative study

abstract:
  We explore the optical properties of periodic layered media containing
left-handed metamaterials. This study is based on several analogies between the
propagation of light in metamaterials and charge transport in graphene. We
derive the conditions for these two problems become equivalent, i.e., the
equations and the boundary conditions when the corresponding wave functions
coincide. We show that the photonic band-gap structure of a periodic system
built of alternating left- and right-handed dielectric slabs contains conical
singularities similar to the Dirac points in the energy spectrum of charged
quasiparticles in graphene. Such singularities in the zone structure of the
infinite systems give rise to rather unusual properties of light transport in
finite samples. In an insightful numerical experiment (the propagation of a
Gaussian beam through a mixed stack of normal and meta-dielectrics) we
simultaneously demonstrate four Dirac point-induced anomalies: (i)
diffusion-like decay of the intensity at forbidden frequencies, (ii) focusing
and defocussing of the beam, (iii) absence of the transverse shift of the beam,
and (iv) a spatial analogue of the Zitterbewegung effect. All of these
phenomena take place in media with non-zero average refractive index, and can
be tuned by changing either the geometrical and electromagnetic parameters of
the sample,or the frequency and the polarization of light.


title: Marginal Fluctuations as Instantons on M2/D2-Branes

abstract:
  We introduce some (anti)M/D-branes through turning on the corresponding field
strengths of the eleven- and ten-dimensional supergravity theories over AdS_4 x
M^(7/6) spaces, where we use S^7/Z_k and CP^3 for the internal spaces. Indeed,
when we add M2/D2-branes on the same directions with the near horizon branes of
Aharony-Bergman-Jafferis-Maldacena model, all symmetries and supersymmetries
are preserved trivially. In the case, we gain a localized object just in the
horizon. This normalizable bulk massless scalar mode is a singlet of SO(8) and
SU(4)x U(1), and agrees with a marginal boundary operator of the conformal
dimension of {\Delta}_+=3. However, after performing a special conformal
transformation, we see that the solution is localized in the Euclideanized
AdS_4 space and is attributable to the included anti-M2/D2-branes, which are
also necessary to ensure that there is no backreaction. The resultant theory
now breaks all N=8,6 supersymmetries to N=0 while other symmetries are so
preserved. The dual boundary operator then sets up from the skew-whiffing of
the representations 8_s and 8_v for the supercharges and scalars respectively,
while the fermions remain fixed in 8_c of the original theory. Besides, we also
address another alternate bulk to boundary matching procedure through turning
on one of the gauge fields of the full U(N)_k x U(N)_-k gauge group in the same
lines with the similar situation faced in AdS_5/CFT_4 correspondence. The
latter approach covers the difficulty already faced with of the bulk-boundary
matching procedure for k=1,2 as well.


title: Characterization of worst-case GMRES

abstract:
  Given a matrix $A$ and iteration step $k$, we study a best possible
attainable upper bound on the GMRES residual norm that does not depend on the
initial vector $b$. This quantity is called the worst-case GMRES approximation.
We show that the worst case behavior of GMRES for the matrices $A$ and $A^T$ is
the same, and we analyze properties of initial vectors for which the worst-case
residual norm is attained. In particular, we show that such vectors satisfy a
certain "cross equality", and we characterize them as right singular vectors of
the corresponding GMRES residual matrix. We show that the worst-case GMRES
polynomial may not be uniquely determined, and we consider the relation between
the worst-case and the ideal GMRES approximations, giving new examples in which
the inequality between the two quantities is sharp at all iteration steps
$k\geq 3$. Finally, we give a complete characterization of how the values of
the approximation problems in the context of worst-case and ideal GMRES for a
real matrix change, when one considers complex (rather than real) polynomials
and initial vectors in these problems.


title: Power and spherical series over real alternative *-algebras

abstract:
  We study two types of series over a real alternative $^*$-algebra $A$. The
first type are series of the form $\sum_{n} (x-y)^{\punto n}a_n$, where $a_n$
and $y$ belong to $A$ and $(x-y)^{\punto n}$ denotes the $n$--th power of $x-y$
w.r.t.\ the usual product obtained by requiring commutativity of the
indeterminate $x$ with the elements of $A$. In the real and in the complex
cases, the sums of power series define, respectively, the real analytic and the
holomorphic functions. In the quaternionic case, a series of this type
produces, in the interior of its set of convergence, a function belonging to
the recently introduced class of slice regular functions. We show that also in
the general setting of an alternative algebra $A$, the sum of a power series is
a slice regular function. We consider also a second type of series, the
spherical series, where the powers are replaced by a different sequence of
slice regular polynomials. It is known that on the quaternions, the set of
convergence of these series is an open set, a property not always valid in the
case of power series. We characterize the sets of convergence of this type of
series for an arbitrary alternative $^*$-algebra $A$. In particular, we prove
that these sets are always open in the quadratic cone of $A$. Moreover, we show
that every slice regular function has a spherical series expansion at every
point.


title: Simulating fermion production in 1+1 dimensional QED

abstract:
  We investigate fermion--anti-fermion production in 1+1 dimensional QED using
real-time lattice techniques. In this non-perturbative approach the full
quantum dynamics of fermions is included while the gauge field dynamics can be
accurately represented by classical-statistical simulations for relevant field
strengths. We compute the non-equilibrium time evolution of gauge invariant
correlation functions implementing 'low-cost' Wilson fermions. Introducing a
lattice generalization of the Dirac-Heisenberg-Wigner function, we recover the
Schwinger formula in 1+1 dimensions in the limit of a static background field.
We discuss the decay of the field due to the backreaction of the created
fermion--anti-fermion pairs and apply the approach to strongly inhomogeneous
gauge fields. The latter allows us to discuss the striking phenomenon of a
linear rising potential building up between produced fermion bunches after the
initial electric pulse ceased.


title:
Periodic spatial variation of the electron-phonon interaction in
  epitaxial graphene on Ru(0001

abstract:
  We have performed low temperature scanning tunnelling spectroscopy (STS)
measurements on graphene epitaxially grown on Ru(0001). An inelastic feature,
related to the excitation of a vibrational breathing mode of the graphene
lattice, was found at 360 meV. The change in the differential electrical
conductance produced by this inelastic feature, which is associated with the
electron-phonon interaction strength, varies spatially from one position to
other of the graphene supercell. This inhomogeneity in the electronic
properties of graphene on Ru(0001) results from local variations of the
carbon-ruthenium interaction due to the lattice mismatch between the graphene
and the Ru(0001) lattices.


title: Sterile neutrinos and $R_K$

abstract:
  We study the violation of lepton flavour universality in light meson decays
due to the presence of non-zero mixings between the active neutrinos with new
sterile states. The modified $W \ell \nu$ vertices, arising from a
non-unitarity leptonic mixing matrix intervening in charged currents, might
lead to a tree-level enhancement of $R_{P} = \Gamma (P \to e \nu) / \Gamma (P
\to \mu \nu)$, with $P=K, \pi$. These enhancements are illustrated in the case
of the inverse seesaw, showing that one can saturate the current experimental
bounds on $\Delta r_{K}$ (and $\Delta r_{\pi}$), while in agreement with the
different experimental and observational constraints.


title: The SMAA-PROMETHEE methods

abstract:
  PROMETHEE methods are widely used in Multiple Criteria Decision Aiding (MCDA)
to deal with real decision making problems. A crucial aspect of the classical
PROMETHEE methods is the choice of criteria weights. In this paper, we propose
to apply the Stochastic Multiobjective Acceptability Analysis (SMAA) to the
classical PROMETHEE methods and to the bipolar PROMETHEE methods in order to
explore the whole set of weights compatible with some preference information
provided by the Decision Maker (DM). A didactic example describes the
application of the presented methodology to a student evaluation problem.


title:
Gigantic magnetic field polarization and magnetoelectric coupling in a
  ferrimagnetic oxide CaBaCo4O7

abstract:
  The single crystal study of CaBaCo4O7, a non collinear ferrimagnet (TC=64K),
with a polar orthorhombic space group (Pbn21) between 4 K and 293 K, shows the
appearance below TC of a large electric polarization along its c axis, reaching
17mC.m-2 at 10K. At 62.5K, a magnetic field driven giant variation of
polarization, P(9T)-P(0T)=8mC.m-2, is observed. Moreover, the present
magnetoelectric measurements, are fully consistent with the m'm2' magnetic
point group, strongly supporting that this oxide is also ferrotoroidic. This
ferrimagnetic oxide, which belongs to the '114' structural family, opens an
avenue for the search of new magnetoelectrics.


title: Generic linear cocycles over a minimal base

abstract:
  We prove that a generic linear cocycle over a minimal base dynamics of finite
dimension has the property that the Oseledets splitting with respect to any
invariant probability coincides almost everywhere with the finest dominated
splitting. Therefore the restriction of the generic cocycle to a subbundle of
the finest dominated splitting is uniformly subexponentially quasiconformal.
This extends a previous result for SL(2,R)-cocycles due to Avila and the
author.


title:
Reply to comment of Shukla et al. on 'On "Novel attractive forces"
  between ions in quantum plasmas - failure of linearized quantum
  hydrodynamics'

abstract:
  In an earlier paper we demonstrated that the "novel attractive force" between
protons in dense hydrogen reported by Shukla and Eliasson based on linearized
quantum hydrodynamics (LQHD) is wrong. As benchmark results we used state of
the art density functional theory (DFT) simulations. In their response to that
paper Shukla et al. (arXiv:1112.5556) claimed that the disagreement is due to a
failure of DFT. Here we show - by comparing the properties and limitations of
DFT and QHD - that their statements have no scientific basis and that DFT is a
suitable benchmark for more approximate approaches such as QHD and LQHD.


title: Mapping Citation Patterns of Book Chapters in the Book Citation Index

abstract:
  In this paper we provide the reader with a visual representation of
relationships among the impact of book chapters indexed in the Book Citation
Index using information gain values and published by different academic
publishers in specific disciplines. The impact of book chapters can be
characterized statistically by citations histograms. For instance, we can
compute the probability of occurrence of book chapters with a number of
citations in different intervals for each academic publisher. We predict the
similarity between two citation histograms based on the amount of relative
information between such characterizations. We observe that the citation
patterns of book chapters follow a Lotkaian distribution. This paper describes
the structure of the Book Citation Index using 'heliocentric clockwise maps'
which allow the reader not only to determine the grade of similarity of a given
academic publisher indexed in the Book Citation Index with a specific
discipline according to their citation distribution, but also to easily observe
the general structure of a discipline, identifying the publishers with higher
impact and output.


title:
Many-worlds interpretation of quantum theory, mesoscopic anthropic
  principle and biological evolution

abstract:
  We suggest to combine the Anthropic Principle with the Many-Worlds
Interpretation of Quantum Theory. Realizing the multiplicity of worlds it
provides an opportunity of explanation of some important events which are
assumed to be extremely improbable. The Mesoscopic Anthropic Principle
suggested here is aimed to explain appearance of such events which are
necessary for emergence of Life and Mind. It is complementary to the
Cosmological Anthropic Principle explaining the fine tuning of fundamental
constants. We briefly discuss various possible applications of the Mesoscopic
Anthropic Principle including the Solar Eclipses and assembling of complex
molecules. Besides, we address the problem of Time's Arrow in the framework of
the Many-Worlds Interpretation. We suggest the recipe for disentangling of
quantities defined by fundamental physical laws and by an anthropic selection.
The main emphasis is made on the problem of the biological evolution.


title:
Existence of critical points with semi-stiff boundary conditions for
  singular perturbation problems in simply connected planar domains

abstract:
  Let $\Omega$ be a smooth bounded simply connected domain in $\mathbb{R}^2$.
We investigate the existence of critical points of the energy $E_\varepsilon
(u)=1/2\int_\Omega |\nabla u|^2+1/(4\varepsilon^2)\int_\Omega (1-|u|^2)^2$,
where the complex map $u$ has modulus one and prescribed degree $d$ on the
boundary. Under suitable nondegeneracy assumptions on $\Omega$, we prove
existence of critical points for small $\varepsilon$. More can be said when the
prescribed degree equals one. First, we obtain existence of critical points in
domains close to a disc. Next, we prove that critical points exist in "most" of
the domains.


title: The model of randomly distributed polydisperse overlapping spheres

abstract:
  A model of randomly distributed overlapping spheres of different radii is
represented to describe a heterogeneous porous medium. Two-particle correlation
function of the relative position of pores of different radii in the medium
space was calculated and detailed analysis was carried out. The model allows to
characterize the disordered porous medium with the number of nearest neighbors,
the area of all mouths that connect pore with the neighboring pores. These
paramaters depend on the pore size and porosity and --- in addition to the
specific surface area, porosity, and percolation threshold and the distribution
function of pore size.

categories: cond-mat.soft cond-mat.dis-nn cond-mat.stat-mech math-ph math.MP


title: How to make Dupire's local volatility work with jumps

abstract:
  There are several (mathematical) reasons why Dupire's formula fails in the
non-diffusion setting. And yet, in practice, ad-hoc preconditioning of the
option data works reasonably well. In this note we attempt to explain why. In
particular, we propose a regularization procedure of the option data so that
Dupire's local vol diffusion process recreates the correct option prices, even
in manifest presence of jumps.


title: On Graph Deltas for Historical Queries

abstract:
  In this paper, we address the problem of evaluating historical queries on
graphs. To this end, we investigate the use of graph deltas, i.e., a log of
time-annotated graph operations. Our storage model maintains the current graph
snapshot and the delta. We reconstruct past snapshots by applying appropriate
parts of the graph delta on the current snapshot. Query evaluation proceeds on
the reconstructed snapshots but we also propose algorithms based mostly on
deltas for efficiency. We introduce various techniques for improving
performance, including materializing intermediate snapshots, partial
reconstruction and indexing deltas.


title:
The Cauchy problem for indefinite improper affine spheres and their
  Hessian equation

abstract:
  We give a conformal representation for indefinite improper affine spheres
which solve the Cauchy problem for their Hessian equation. As consequences, we
can characterize their geodesics and obtain a generalized symmetry principle.
Then, we classify the helicoidal indefinite improper affine spheres and find a
new family with complete non flat affine metric. Moreover, we present
interesting examples with singular curves and isolated singularities.


title:
$L^p$ estimates for the maximal singular integral in terms of the
  singular integral

abstract:
  This paper continues the study, initiated in the works {MOV} and {MOPV}, of
the problem of controlling the maximal singular integral $T^{*}f$ by the
singular integral $Tf$. Here $T$ is a smooth homogeneous Calder\'on-Zygmund
singular integral operator of convolution type. We consider two forms of
control, namely, in the weighted $L^p(\omega)$ norm and via pointwise estimates
of $T^{*}f$ by $M(Tf)$ or $M^2(Tf)$\,, where $M$ is the Hardy-Littlewood
maximal operator and $M^2=M \circ M$ its iteration. The novelty with respect to
the aforementioned works, lies in the fact that here $p$ is different from 2
and the $L^p$ space is weighted.


title: Quantum correlations in predictive processes

abstract:
  We consider the role of quantum correlations in the efficient use of
information by a predictive quantum system, generalizing a recently proposed
classical measure of non-predictive information to the quantum regime. We show
that, as a quantum system changes state, the non-predictive information held by
another correlated quantum system is exactly equal to the extractable work that
is lost from the second system. We use quantum discord to quantify the quantum
contribution, and demonstrate the possibility of improved thermodynamic
efficiency due to a negative "quantum part" of the lost work. We also give a
thermodynamic interpretation to quantum discord, as the reduction in
extractable work under an optimal classical approximation of a quantum memory.


title: Multimode circuit QED with hybrid metamaterial transmission lines

abstract:
  Quantum transmission lines are a central to superconducting and hybrid
quantum computing. Parallel to these developments are those of left-handed
meta-materials. They have a wide variety of applications in photonics from the
microwave to the visible range such as invisibility cloaks and perfect flat
lenses. For classical guided microwaves, left-handed transmission lines have
been proposed and studied on the macroscopic scale. We combine these ideas in
presenting a left-handed/right-handed hybrid transmission line for applications
in quantum optics on a chip. The resulting system allows circuit QED to reach a
new regime: multi-mode ultra-strong coupling. Out of the many potential
applications of this novel device, we discuss two; the preparation of
multipartite entangled states and its use as a quantum simulator for the
spin-boson model where a quantum phase transition is reached up to finite
size-effects.


title:
Self-similar prior and wavelet bases for hidden incompressible turbulent
  motion

abstract:
  This work is concerned with the ill-posed inverse problem of estimating
turbulent flows from the observation of an image sequence. From a Bayesian
perspective, a divergence-free isotropic fractional Brownian motion (fBm) is
chosen as a prior model for instantaneous turbulent velocity fields. This
self-similar prior characterizes accurately second-order statistics of velocity
fields in incompressible isotropic turbulence. Nevertheless, the associated
maximum a posteriori involves a fractional Laplacian operator which is delicate
to implement in practice. To deal with this issue, we propose to decompose the
divergent-free fBm on well-chosen wavelet bases. As a first alternative, we
propose to design wavelets as whitening filters. We show that these filters are
fractional Laplacian wavelets composed with the Leray projector. As a second
alternative, we use a divergence-free wavelet basis, which takes implicitly
into account the incompressibility constraint arising from physics. Although
the latter decomposition involves correlated wavelet coefficients, we are able
to handle this dependence in practice. Based on these two wavelet
decompositions, we finally provide effective and efficient algorithms to
approach the maximum a posteriori. An intensive numerical evaluation proves the
relevance of the proposed wavelet-based self-similar priors.


title: The splitting theorem in non-smooth context

abstract:
  We prove that an infinitesimally Hilbertian CD(0,N) space containing a line
splits as the product of $R$ and an infinitesimally Hilbertian CD(0,N-1) space.
By `infinitesimally Hilbertian' we mean that the Sobolev space
$W^{1,2}(X,d,m)$, which in general is a Banach space, is an Hilbert space. When
coupled with a curvature-dimension bound, this condition is known to be stable
with respect to measured Gromov-Hausdorff convergence.


title:
DCT and Eigenvectors of Covariance of 1st and 2nd order Discrete
  fractional Brownian motion

abstract:
  This paper establishes connection between discrete cosine transform (DCT) and
1st and 2nd order discrete-time fractional Brownian motion process. It is
proved that the eigenvectors of the auto-covariance matrix of a 1st and 2nd
order discrete-time fractional Brownian motion can be approximated by DCT basis
vectors in the asymptotic sense. Perturbation in eigenvectors from DCT basis
vectors is modeled using the analytic perturbation theory of linear operators.


title:
Nonlinear heat transport in mesoscopic conductors: Rectification,
  Peltier effect and Wiedemann-Franz law

abstract:
  We investigate nonlinear heat properties in mesoscopic conductors using a
scattering theory of transport. Our approach is based on a leading-order
expansion in both the electrical and thermal driving forces. Beyond linear
response, the transport coefficients are functions of the nonequilibrium
screening potential that builds up in the system due to interactions. Within a
mean-field approximation, we self-consistently calculate the heat rectification
properties of a quantum dot attached to two terminals. We discuss nonlinear
contributions to the Peltier effect and find departures from the
Wiedemann-Franz law in the nonlinear regime of transport.


title:
Generation of non-classical photon states in superconducting quantum
  metamaterials

abstract:
  We report a theoretical study of diverse non-classical photon states that can
be realized in superconducting quantum metamaterials. As a particular example
of superconducting quantum metamaterials an array of SQUIDs incorporated in a
low-dissipative transmission line (resonant cavity) will be studied. This
system will be modeled as a set of two-levels systems (qubits) strongly
interacting with resonant cavity photons. We predict and analyze {a
second(first)-order phase transition} between an incoherent (the
high-temperature phase) and coherent (the low-temperatures phase) states of
photons. In equilibrium state the partition function $Z$ of the electromagnetic
field (EF) in the cavity is determined by the effective action
$S_{eff}\{P(\tau)\}$ that, in turn, depends on imaginary-time dependent
momentum of photon field $P(\tau)$. We show that the order parameter of this
phase transition is the $P_{0}(\tau)$ minimizing the effective action of a
whole system. In the incoherent state the order parameter $P_{0}(\tau)=0$ but
at low temperatures we obtain various coherent states characterized by non-zero
values of $P_{0}(\tau)$. This phase transition in many aspects resembles the
Peierls metal-insulator and the metal-superconductor phase transitions. The
critical temperature of such phase transition $T^\star$ is determined by the
energy splitting of two-level systems $\Delta$, a number of SQUIDs in the array
$N$, and the strength of the interaction $\eta$ between SQUIDs and photons in
cavity.