title:
Finite amplitude inhomogeneous waves in Mooney-Rivlin viscoelastic
  solids

abstract:
  New exact solutions are exhibited within the framework of finite
viscoelasticity. More precisely, the solutions correspond to finite-amplitude,
transverse, linearly-polarized, inhomogeneous motions superposed upon a finite
homogeneous static deformation. The viscoelastic body is composed of a
Mooney-Rivlin viscoelastic solid, whose constitutive equation consists in the
sum of an elastic part (Mooney-Rivlin hyperelastic model) and a viscous part
(Newtonian viscous fluid model). The analysis shows that the results are
similar to those obtained for the purely elastic case; inter alia, the normals
to the planes of constant phase and to the planes of constant amplitude must be
orthogonal and conjugate with respect to the B-ellipsoid, where B is the left
Cauchy-Green strain tensor associated with the initial large static
deformation. However, when the constitutive equation is specialized either to
the case of a neo-Hookean viscoelastic solid or to the case of a Newtonian
viscous fluid, a greater variety of solutions arises, with no counterpart in
the purely elastic case. These solutions include travelling inhomogeneous
finite-amplitude damped waves and standing damped waves.


title: Observational challenges in dark energy models

abstract:
  Cosmological distances inferred from supernova Ia observations constitute the
most direct and solid evidence for the recently detected accelerated expansion
of the universe. In this contribution, we show some inconsistencies between two
of the main light-curve fitters used for the elaboration of supernova Ia data
sets, opening new observational challenges regarding the use of these
luminosity distances when combined with CMB and BAO data. We also mention
ongoing analysis related to alternative models. The resolution of these
challenges will be crucial for XXI century cosmology.


title:
Broadband enhancement of spontaneous emission from nitrogen-vacancy
  centers in nanodiamonds by hyperbolic metamaterials

abstract:
  We experimentally demonstrate a broadband enhancement of emission from
nitrogen vacancy centers in nanodiamonds. The enhancement is achieved by using
a multilayer metamaterial with hyperbolic dispersion. The metamaterial is
fabricated as a stack of alternating gold and alumina layers. Our approach
paves the way towards the construction of efficient single-photon sources as
planar on-chip devices.


title:
Surface waves in a deformed isotropic hyperelastic material subject to
  an isotropic internal constraint

abstract:
  An isotropic elastic half space is prestrained so that two of the principal
axes of strain lie in the bounding plane, which itself remains free of
traction. The material is subject to an isotropic constraint of arbitrary
nature. A surface wave is propagated sinusoidally along the bounding surface in
the direction of a principal axis of strain and decays away from the surface.
The exact secular equation is derived by a direct method for such a principal
surface wave; it is cubic in a quantity whose square is linearly related to the
squared wave speed. For the prestrained material, replacing the squared wave
speed by zero gives an explicit bifurcation, or stability, criterion.
Conditions on the existence and uniqueness of surface waves are given. The
bifurcation criterion is derived for specific strain energies in the case of
four isotropic constraints: those of incompressibility, Bell, constant area,
and Ericksen. In each case investigated, the bifurcation criterion is found to
be of a universal nature in that it depends only on the principal stretches,
not on the material constants. Some results related to the surface stability of
arterial wall mechanics are also presented.


title:
Anisotropic transport and magnetic properties, and magnetic-field tuned
  states of CeZn11 single crystals

abstract:
  We present detailed temperature and field dependent data obtained from
magnetization, resistivity, heat capacity, Hall resistivity and thermoelectric
power measurements performed on single crystals of CeZn11. The compounds orders
antiferromagnetically at $\sim$ 2 K. The zero-field resistivity and TEP data
show features characteristic of a Ce-based intermetallic with crystal electric
field splitting and possible correlated, Kondo lattice effects. We constructed
the T-H phase diagram for the magnetic field applied along the easy, [110],
direction which shows that the magnetic field required to suppress T_N below
0.4 K is in the range of 45-47.5 kOe. A linear behavior of the rho(T) data,
H||[110], was observed only for H=45 kOe for 0.46 K<T<1.96 K followed by the
Landau-Fermi-liquid regime for a limited range of fields, 47.5 kOe< H<60 kOe.
From the analysis of our data, it appears that CeZn11 is a weakly to moderately
correlated local moment compound with rather small Kondo temperature. The
thermoelectric and transport properties of CeZn11 are mostly governed by the
CEF effects. Given the very high quality of our single crystals, quantum
oscillations are found for both CeZn11 and its non-magnetic analogue, LaZn11.


title:
Clustering Consumption in Queues: A Scalable Model for Electric Vehicle
  Scheduling

abstract:
  In this paper, we introduce a scalable model for the aggregate electricity
demand of a fleet of electric vehicles, which can provide the right balance
between model simplicity and accuracy. The model is based on classification of
tasks with similar energy consumption characteristics into a finite number of
clusters. The aggregator responsible for scheduling the charge of the vehicles
has two goals: 1) to provide a hard QoS guarantee to the vehicles at the lowest
possible cost; 2) to offer load or generation following services to the
wholesale market. In order to achieve these goals, we combine the scalable
demand model we propose with two scheduling mechanisms, a near-optimal and a
heuristic technique. The performance of the two mechanisms is compared under a
realistic setting in our numerical experiments.


title: Flux-transfer losses in helically wound superconducting power cables

abstract:
  Minimization of ac losses is essential for economic operation of
high-temperature superconductor (HTS) ac power cables. A favorable
configuration for the phase conductor of such cables has two counter-wound
layers of HTS tape-shaped wires lying next to each other and helically wound
around a flexible cylindrical former. However, if magnetic materials such as
magnetic substrates of the tapes lie between the two layers, or if the winding
pitch angles are not opposite and essentially equal in magnitude to each other,
current distributes unequally between the two layers. Then, if at some point in
the ac cycle the current of either of the two layers exceeds its critical
current, a large ac loss arises from the transfer of flux between the two
layers. A detailed review of the formalism, its application to the case of
paramagnetic substrates including the calculation of this flux transfer loss is
presented.


title: Planetary-mass companions to the K-giants BD+15 2940 and HD 233604

abstract:
  We report the discovery of planetary-mass companions to two red giants by the
ongoing Penn State - Torun Planet Search (PTPS) conducted with the 9.2-m
Hobby-Eberly Telescope. The 1.1 Ms K0-giant, BD+15 2940, has a 1.1 Mj minimum
mass companion orbiting the star at a 137.5-day period in a 0.54 AU orbit what
makes it the closest - in planet around a giant and possible subject of
engulfment as the consequence of stellar evolution. HD 233604, a 1.5 Ms
K5-giant, is orbited by a 6.6 Mj minimum mass planet which has a period of 192
days and a semi-major axis of only 0.75 AU making it one of the least distant
planets to a giant star. The chemical composition analysis of HD 233604 reveals
a relatively high 7Li abundance which may be a sign of its early evolutionary
stage or recent engulfment of another planet in the system.
  We also present independent detections of planetary-mass companions to HD
209458 and HD 88133, and stellar activity-induced RV variations in HD 166435,
as part of the discussion of the observing and data analysis methods used in
the PTPS project.


title: The Prouhet-Tarry-Escott Problem and Generalized Thue-Morse Sequences

abstract:
  We present new methods of generating Prouhet-Tarry-Escott partitions of
arbitrarily large regularity. One of these methods generalizes the construction
of the Thue-Morse sequence to finite alphabets with more than two letters. We
show how one can use such partitions to (theoretically) pour the same volume
coffee from an urn into a finite number of cups so that each cup gets almost
the same amount of caffeine.


title:
Monte Carlo simulation of the nonadditive restricted primitive model of
  ionic fluids: Phase diagram and clustering

abstract:
  We report an accurate Monte Carlo calculation of the phase diagram and
clustering properties of the restricted primitive model with non-additive
hard-sphere diameters. At high density the positively non-additive fluid shows
more clustering than the additive model and the negatively non-additive fluid
shows less clustering than the additive model, at low density the reverse
scenario appears. A negative nonadditivity tends to favor the formation of
neutrally charged clusters starting from the dipole. A positive nonadditivity
favors the pairing of like ions at high density. The critical point of the
gas-liquid phase transition moves at higher temperatures and higher densities
for a negative nonadditivity and at lower temperatures and lower densities for
a positive nonadditivity. The law of corresponding states does not seem to hold
strictly. Our results can be used to interpret recent experimental works on
room temperature ionic liquids.


title: Frozen into stripes: fate of the critical Ising model after a quench

abstract:
  In this work we study numerically the final state of the two dimensional
ferromagnetic critical Ising model after a quench to zero temperature.
Beginning from equilibrium at $T_c$, the system can be blocked in a variety of
infinitely long lived stripe states in addition to the ground state. Similar
results have already been obtained for an infinite temperature initial
condition and an interesting connection to exact percolation crossing
probabilities has emerged. Here we complete this picture by providing a new
example of stripe states precisely related to initial crossing probabilities
for various boundary conditions. We thus show that this is not specific to
percolation but rather that it depends on the properties of spanning clusters
in the initial state.


title: k-Modulus Method for Image Transformation

abstract:
  In this paper, we propose a new algorithm to make a novel spatial image
transformation. The proposed approach aims to reduce the bit depth used for
image storage. The basic technique for the proposed transformation is based of
the modulus operator. The goal is to transform the whole image into multiples
of predefined integer. The division of the whole image by that integer will
guarantee that the new image surely less in size from the original image. The
k-Modulus Method could not be used as a stand alone transform for image
compression because of its high compression ratio. It could be used as a scheme
embedded in other image processing fields especially compression. According to
its high PSNR value, it could be amalgamated with other methods to facilitate
the redundancy criterion.


title: Sequences of Gluing Bifurcations in an Analog Electronic Circuit

abstract:
  We report on the experimental investigation of gluing bifurcations in the
analog electronic circuit which models a dynamical system of the third order:
Lorenz equations with an additional quadratic nonlinearity. Variation of one of
the resistances in the circuit changes the coefficient at this nonlinearity and
enables transition from the Lorenz route to chaos to a different scenario which
leads, through the sequence of homoclinic bifurcations, from periodic
oscillations of the voltage to the chaotic state. A single bifurcation "glues"
in the phase space two stable periodic orbits and creates a new one, with the
doubled length: a bifurcation sequence results in the birth of the chaotic
attractor.


title: Towards a Networks-of-Networks Framework for Cyber Security

abstract:
  Networks-of-networks (NoN) is a graph-theoretic model of interdependent
networks that have distinct dynamics at each network (layer). By adding special
edges to represent relationships between nodes in different layers, NoN
provides a unified mechanism to study interdependent systems intertwined in a
complex relationship. While NoN based models have been proposed for
cyber-physical systems, in this position paper we build towards a three-layered
NoN model for an enterprise cyber system. Each layer captures a different facet
of a cyber system. We present in-depth discussion for four major graph-
theoretic applications to demonstrate how the three-layered NoN model can be
leveraged for continuous system monitoring and mission assurance.


title: A semantic account of strong normalization in Linear Logic

abstract:
  We prove that given two cut free nets of linear logic, by means of their
relational interpretations one can: 1) first determine whether or not the net
obtained by cutting the two nets is strongly normalizable 2) then (in case it
is strongly normalizable) compute the maximal length of the reduction sequences
starting from that net.


title: Deep Scattering Spectrum

abstract:
  A scattering transform defines a locally translation invariant representation
which is stable to time-warping deformations. It extends MFCC representations
by computing modulation spectrum coefficients of multiple orders, through
cascades of wavelet convolutions and modulus operators. Second-order scattering
coefficients characterize transient phenomena such as attacks and amplitude
modulation. A frequency transposition invariant representation is obtained by
applying a scattering transform along log-frequency. State-the-of-art
classification results are obtained for musical genre and phone classification
on GTZAN and TIMIT databases, respectively.


title: VERITAS contributions to CF6-A: Cosmic Rays, Gamma Rays and Neutrinos

abstract:
  This white paper describes the contributions of the VERITAS gamma-ray
telescope array to the CF6-A subgroup of the 'Cosmic Frontier' working group,
part of the Snowmass Community Summer Study 2013.


title: Geometric Nonlinear PID Control of a Quadrotor UAV on SE(3)

abstract:
  Nonlinear PID control systems for a quadrotor UAV are proposed to follow an
attitude tracking command and a position tracking command. The control systems
are developed directly on the special Euclidean group to avoid singularities of
minimal attitude representations or ambiguity of quaternions. A new form of
integral control terms is proposed to guarantee almost global asymptotic
stability when there exist uncertainties in the quadrotor dynamics. A rigorous
mathematical proof is given. Numerical example illustrating a complex maneuver,
and a preliminary experimental result are provided.


title:
Comment on 'Field ion microscopy characterized tips in noncontact atomic
  force microscopy: Quantification of long-range force interactions'

abstract:
  A recent article by Falter et al. (Phys. Rev. B 87, 115412 (2013)) presents
experimental results using field ion microscopy characterized tips in
noncontact atomic force microscopy in order to characterize electrostatic and
van der Waals long range forces. In the article, the tip radius was
substantially underestimated at ~4.7 nm rather than ~8.1 nm due to subtleties
in the application of the ring counting method. We point out where common
errors in ring counting arise in order to benefit future experimental work in
which the determination of tip radius by FIM is important.


title: Casimir Momentum of a Chiral Molecule in a Magnetic Field

abstract:
  In a classical description, a neutral, polarizable object acquires a kinetic
momentum when exposed to crossed electric and magnetic fields. In the presence
of only a magnetic field no such momentum exists classically, although it is
symmetry-allowed for an object lacking mirror symmetry. We perform a full QED
calculation to show that the quantum vacuum coupled to a chiral molecule
provides a kinetic "Casimir" momentum directed along the magnetic field,
proportional to its rotatory power and the fine structure constant.


title: Nuclear magnetic resonance as a probe of electronic states of Bi2Se3

abstract:
  We present magnetotransport and Bi-209 nuclear magnetic resonance (NMR) data
on a series of single crystals of Bi2Se3, Bi2Te2Se and Cu_xBi2Se3 with varying
carrier concentrations. The Knight shift of the bulk nuclei is strongly
correlated with the carrier concentration via a hyperfine coupling of 27 ueV,
which may have important consequences for scattering of the protected surface
states. Surprisingly we find that the NMR linewidths and the spin lattice
relaxation rate appear to be dominated by the presence of localized spins,
which may be related to the presence of Se vacancies.


title:
High temperature plasmonics: Narrowband, tunable, near-field thermal
  sources

abstract:
  We propose multiple approaches for controlling Wien's displacement law in the
near-field leading to narrowband, tunable, spatially-coherent high temperature
thermal sources. We show that narrowband super-planckian thermal emission
relevant to the wavelength ranges for near-field thermophotovoltaics can be
achieved by utilizing engineered plasmonic states of metals with a high melting
point. Along with conventional thin film surface plasmon polaritons of high
temperature plasmonic metals, we also introduce multiple different approaches
to narrowband near field thermal emission a) epsilon-near-zero metamaterials b)
tunable surface-plasmon-polaritons of anisotropic metamaterials and c) photonic
van hove singularities. Our work solves the critical issue of a narrowband
thermal source for near-field thermophotovoltaics.


title: Dynamic Newton-Puiseux Theorem

abstract:
  A constructive version of Newton-Puiseux theorem for computing the Puiseux
expansions of algebraic curves is presented. The proof is based on a classical
proof by Abhyankar. Algebraic numbers are evaluated dynamically; hence the base
field need not be algebraically closed and a factorization algorithm of
polynomials over the base field is not needed. The extensions obtained are a
type of regular algebras over the base field and the expansions are given as
formal power series over these algebras.


title: Constructing homotopy equivalences of chain complexes of free ZG-modules

abstract:
  We describe a general method for algorithmic construction of G-equivariant
chain homotopy equivalences from non-equivariant ones. As a consequence, we
obtain an algorithm for computing equivariant (co)homology of Eilenberg-MacLane
spaces K(pi,n), where pi is a finitely generated ZG-module.
  This result will be used in a forthcoming paper to construct equivariant
Postnikov towers of simply connected spaces with free actions of a finite group
G and further to compute stable equivariant homotopy classes of maps between
such spaces.
  The methods of this paper work for modules over any non-negatively graded
differential graded algebra, whose underlying graded abelian group is free with
1 as one of the generators.


title:
Brittleness of Bayesian Inference Under Finite Information in a
  Continuous World

abstract:
  We derive, in the classical framework of Bayesian sensitivity analysis,
optimal lower and upper bounds on posterior values obtained from Bayesian
models that exactly capture an arbitrarily large number of finite-dimensional
marginals of the data-generating distribution and/or that are as close as
desired to the data-generating distribution in the Prokhorov or total variation
metrics; these bounds show that such models may still make the largest possible
prediction error after conditioning on an arbitrarily large number of sample
data measured at finite precision. These results are obtained through the
development of a reduction calculus for optimization problems over measures on
spaces of measures. We use this calculus to investigate the mechanisms that
generate brittleness/robustness and, in particular, we observe that learning
and robustness are antagonistic properties. It is now well understood that the
numerical resolution of PDEs requires the satisfaction of specific stability
conditions. Is there a missing stability condition for using Bayesian inference
in a continuous world under finite information?


title: Ionization Efficiency Study for Low Energy Nuclear Recoils in Germanium

abstract:
  We used the internal conversion ($E_0$ transition) of germanium-72 to
indirectly measure the low energy nuclear recoils of germanium. Together with a
reliable Monte Carlo package, in which we implement the internal conversion
process, the data was compared to the Lindhard ($k$=0.159) and Barker-Mei
models. A shape analysis indicates that both models agree well with data in the
region of interest within 4%. The most probable value (MPV) of the nuclear
recoils obtained from the shape analysis is 17.5 keV with an average
path-length of 0.014 $\mu$m.


title: Intersections of sets, diophantine equations and Fourier analysis

abstract:
  A classical theorem due to Mattila (see \cite{Mat84}; see also \cite{M95},
Chapter 13) says that if $A,B \subset {\Bbb R}^d$ of Hausdorff dimension $s_A,
s_B$, respectively, with $s_A+s_B \ge d$, $s_B>\frac{d+1}{2}$ and
$dim_{{\mathcal H}}(A \times B)=s_A+s_B\ge d$, then $$ dim_{{\mathcal H}}(A
\cap (z+B)) \leq s_A+s_B-d$$ for almost every $z \in {\Bbb R}^d$, in the sense
of Lebesgue measure.
  In this paper, we replace the Hausdorff dimension on the left hand side of
the first inequality above by the upper Minkowski dimension, replace the
Lebesgue measure of the set of translates by a Hausdorff measure on a set of
sufficiently large dimension and replace the translation and rotation group by
a more general variable coefficient family of transformations. Interesting
arithmetic issues arise in the consideration of sharpness examples. These
results are partly motivated by those in \cite{EIT11} and \cite{IJL10} where in
the former the classical regular value theorem from differential geometry was
investigated in a fractal setting and in the latter discrete incidence theory
is explored from an analytic standpoint. Fourier Integral Operator bounds and
other techniques of harmonic analysis play a crucial role in our investigation.
  We also consider, in the spirit of the Furstenberg conjecture, inverse
problems for intersections by asking how small a dimension of a set can be
given that the dimension of its intersections with a suitably well-curved
family of manifolds is bounded from below by a given threshold.
  Finally, we shall discuss applications of our estimates to the problem of
estimating the number of solutions of systems of diophantine equations over
integers.


title:
Negative eigenvalues of partial transposition of arbitrary bipartite
  states

abstract:
  The partial transposition of a two-qubit state has at most one negative
eigenvalue and all the eigenvalues lie in [-1/2,1]. In this Brief Report, we
extend this result by Sanpera et al. [A. Sanpera, R. Tarrach and G. Vidal,
Phys. Rev. A 58, 826 (1998)] to arbitrary bipartite states. We show that
partial transposition of an $m\otimes n$ state can not have more than
(m-1)(n-1) number of negative eigenvalues. Low-dimensional states have been
studied to show the tightness of this result and explicit examples have been
provided for $mn\le 9$. It is also shown that all the eigenvalues of partial
transposition lie within [-1/2,1]. Some possible applications are also
discussed.


title: Several characterizations of the 4--valued modal algebras

abstract:
  A. Monteiro, in 1978, defined the algebras he named tetravalent modal
algebras, will be called 4--valued modal algebras in this work. These algebras
constitute a generalization of the 3--valued Lukasiewicz algebras defined by
Moisil.
  The theory of the 4--valued modal algebras has been widely developed by I.
Loureiro in [6,7,8,9,10,11,12] and by A. V. Figallo in [2,3,4,5].
  J. Font and M. Rius indicated, in the introduction to the important work [1],
a brief but detailed review on the $4-$valued modal algebras.
  In this work varied characterizations are presented that show the "closeness"
this variety of algebras has with other well--known algebras related to the
algebraic counterparts of certain logics.


title: A Bayesian approach for predicting the popularity of tweets

abstract:
  We predict the popularity of short messages called tweets created in the
micro-blogging site known as Twitter. We measure the popularity of a tweet by
the time-series path of its retweets, which is when people forward the tweet to
others. We develop a probabilistic model for the evolution of the retweets
using a Bayesian approach, and form predictions using only observations on the
retweet times and the local network or "graph" structure of the retweeters. We
obtain good step ahead forecasts and predictions of the final total number of
retweets even when only a small fraction (i.e., less than one tenth) of the
retweet path is observed. This translates to good predictions within a few
minutes of a tweet being posted, and has potential implications for
understanding the spread of broader ideas, memes, or trends in social networks.


title: Modular Inverse and Reciprocity Formula

abstract:
  This paper proves a reciprocity formula for modular inverses for non-zero
integers and demonstrates some applications of the reciprocity formula in
calculating or verifying some modular inverses of specific forms, including the
modular inverse of a Gaussian integer modulo another Gaussian integer.


title:
Optomechanical back-action evading measurement without parametric
  instability

abstract:
  We review a scheme for performing a back-action evading measurement of one
mechanical quadrature in an optomechanical setup. The experimental application
of this scheme has been limited by parametric instabilities caused in general
by a slight dependence of the mechanical frequency on the electromagnetic
energy in the cavity. We find that a simple modification to the optical drive
can effectively eliminate the parametric instability even at high intracavity
power, allowing realistic devices to achieve sub-zero-point uncertainties in
the measured quadrature.


title: Practices in source code sharing in astrophysics

abstract:
  While software and algorithms have become increasingly important in
astronomy, the majority of authors who publish computational astronomy research
do not share the source code they develop, making it difficult to replicate and
reuse the work. In this paper we discuss the importance of sharing scientific
source code with the entire astrophysics community, and propose that journals
require authors to make their code publicly available when a paper is
published. That is, we suggest that a paper that involves a computer program
not be accepted for publication unless the source code becomes publicly
available. The adoption of such a policy by editors, editorial boards, and
reviewers will improve the ability to replicate scientific results, and will
also make the computational astronomy methods more available to other
researchers who wish to apply them to their data.


title: Band surgeries and crossing changes between fibered links

abstract:
  We characterize cutting arcs on fiber surfaces that produce new fiber
surfaces, and the changes in monodromy resulting from such cuts. As a
corollary, we characterize band surgeries between fibered links and introduce
an operation called Generalized Hopf banding. We further characterize
generalized crossing changes between fibered links, and the resulting changes
in monodromy.


title:
Minimal Residual Methods for Complex Symmetric, Skew Symmetric, and Skew
  Hermitian Systems

abstract:
  While there is no lack of efficient Krylov subspace solvers for Hermitian
systems, there are few for complex symmetric, skew symmetric, or skew Hermitian
systems, which are increasingly important in modern applications including
quantum dynamics, electromagnetics, and power systems. For a large consistent
complex symmetric system, one may apply a non-Hermitian Krylov subspace method
disregarding the symmetry of $A$, or a Hermitian Krylov solver on the
equivalent normal equation or an augmented system twice the original dimension.
These have the disadvantages of increasing either memory, conditioning, or
computational costs. An exception is a special version of QMR by Freund (1992),
but that may be affected by non-benign breakdowns unless look-ahead is
implemented; furthermore, it is designed for only consistent and nonsingular
problems. For skew symmetric systems, Greif and Varah (2009) adapted CG for
nonsingular skew symmetric linear systems that are necessarily and
restrictively of even order.
  We extend the symmetric and Hermitian algorithms MINRES and MINRES-QLP by
Choi, Paige and Saunders (2011) to complex symmetric, skew symmetric, and skew
Hermitian systems. In particular, MINRES-QLP uses a rank-revealing QLP
decomposition of the tridiagonal matrix from a three-term recurrent
complex-symmetric Lanczos process. Whether the systems are real or complex,
singular or invertible, compatible or inconsistent, MINRES-QLP computes the
unique minimum-length, i.e., pseudoinverse, solutions. It is a significant
extension of MINRES by Paige and Saunders (1975) with enhanced stability and
capability.


title: Structured Functional Principal Component Analysis

abstract:
  Motivated by modern observational studies, we introduce a class of functional
models that expands nested and crossed designs. These models account for the
natural inheritance of correlation structure from sampling design in studies
where the fundamental sampling unit is a function or image. Inference is based
on functional quadratics and their relationship with the underlying covariance
structure of the latent processes. A computationally fast and scalable
estimation procedure is developed for ultra-high dimensional data. Methods are
illustrated in three examples: high-frequency accelerometer data for daily
activity, pitch linguistic data for phonetic analysis, and EEG data for
studying electrical brain activity during sleep.


title: Elementary excitations and crossover phenomenon in liquids

abstract:
  The elementary excitations of vibration in solids are phonons. But in liquids
phonons are extremely short-lived and marginalized. In this letter through
classical and ab-initio molecular dynamics simulations of the liquid state of
various metallic systems we show that different excitations, the local
configurational excitations in the atomic connectivity network, are the
elementary excitations in high temperature metallic liquids. We also
demonstrate that the competition between the configurational excitations and
phonons determines the so-called crossover phenomenon in liquids. These
discoveries open the way to the explanation of various complex phenomena in
liquids, such as fragility and the rapid increase in viscosity toward the glass
transition, in terms of these excitations.


title: On limit set of KdV flow: An extension of Remling theorem

abstract:
  C. Remling obtained a theorem on limit set of the shift operation on a space
of functions on R when the associated 1-D half line Schr\"odinger operators
have absolutely continuous component in their spectrum. The purpose of the
paper is to define a KdV flow on a certain class of functions containing
algebro-geometric functions and to extend this result to the KdV flow.


title: Krein's strings whose spectral functions are of polynomial growth

abstract:
  In the case of Krein's strings with spectral functions of polynomial growth a
necessary and sufficient condition for the Krein's correspondence to be
continuous is given.


title: Supersymmetry and the Modular Double

abstract:
  A counterpart of the modular double for quantum superalgebra
$\cU_q(\osp(1|2))$ is constructed by means of supersymmetric quantum mechanics.
We also construct the $R$-matrix operator acting in the corresponding
representations, which is expressed via quantum dilogarithm.


title: Surface solitons in PT symmetric potentials

abstract:
  We investigate light beam propagation along the interface between linear and
nonlinear media with parity-time PT symmetry, and derive an equation governing
the beam propagation. A novel class of two-dimensional PT surface solitons are
found analytically and numerically, and checked to be stable over a wide range
of PT potential structures and parameters. These surface solitons do not
require a power threshold. The transverse power flow across beam is examined
within the solitons and found to be caused by the nontrivial phase structure of
the solitons. PT surface solitons are possibly observed experimentally in
photorefractive crystals.


title: Principal Nested Spheres for Time Warped Functional Data Analysis

abstract:
  There are often two important types of variation in functional data: the
horizontal (or phase) variation and the vertical (or amplitude) variation.
These two types of variation have been appropriately separated and modeled
through a domain warping method (or curve registration) based on the Fisher Rao
metric. This paper focuses on the analysis of the horizontal variation,
captured by the domain warping functions. The square-root velocity function
representation transforms the manifold of the warping functions to a Hilbert
sphere. Motivated by recent results on manifold analogs of principal component
analysis, we propose to analyze the horizontal variation via a Principal Nested
Spheres approach. Compared with earlier approaches, such as approximating
tangent plane principal component analysis, this is seen to be the most
efficient and interpretable approach to decompose the horizontal variation in
some examples.


title: On mathematical foundation of the Brownian motor theory

abstract:
  The paper contains mathematical justification of basic facts concerning the
Brownian motor theory. The homogenization theorems are proved for the Brownian
motion in periodic tubes with a constant drift. The study is based on an
application of the Bloch decomposition. The effective drift and effective
diffusivity are expressed in terms of the principal eigenvalue of the Bloch
spectral problem on the cell of periodicity as well as in terms of the harmonic
coordinate and the density of the invariant measure. We apply the formulas for
the effective parameters to study the motion in periodic tubes with nearly
separated dead zones.


title: Isospin violating dark matter being asymmetric

abstract:
  The isospin violating dark matter (IVDM) scenario offers an interesting
possibility to reconcile conflicting results among direct dark matter search
experiments for a mass range around 10 GeV. We consider two simple
renormalizable IVDM models with a complex scalar dark matter and a Dirac
fermion dark matter, respectively, whose stability is ensured by the
conservation of "dark matter number". Although both models successfully work as
the IVDM scenario with destructive interference between effective couplings to
proton and neutron, the dark matter annihilation cross section is found to
exceed the cosmological/astrophysical upper bounds. Then, we propose a simple
scenario to reconcile the IVDM scenario with the cosmological/astrophysical
bounds, namely, the IVDM being asymmetric. Assuming a suitable amount of dark
matter asymmetry has been generated in the early Universe, the annihilation
cross section beyond the cosmological/astrophysical upper bound nicely works to
dramatically reduce the anti-dark matter relic density and as a result, the
constraints from dark matter indirect searches are avoided. We also discuss
collider experimental constraints on the models and an implication to Higgs
boson physics.


title: On the mixed $f$-divergence for multiple pairs of measures

abstract:
  In this paper, the concept of the classical $f$-divergence (for a pair of
measures) is extended to the mixed $f$-divergence (for multiple pairs of
measures). The mixed $f$-divergence provides a way to measure the difference
between multiple pairs of (probability) measures. Properties for the mixed
$f$-divergence are established, such as permutation invariance and symmetry in
distributions. An Alexandrov-Fenchel type inequality and an isoperimetric type
inequality for the mixed $f$-divergence will be proved and applications in the
theory of convex bodies are given.


title:
Bounds for the first Hilbert coefficients of ${\mathfrak m}$-primary
  ideals

abstract:
  This paper purposes to characterize Noetherian local rings $(A, {\mathfrak
m})$ of positive dimension such that the first Hilbert coefficients of
${\mathfrak m}$-primary ideals in $A$ range among only finitely many values.
Examples are explored.


title: The mass of first stars

abstract:
  We perform a three dimensional radiation hydrodynamics simulation to
investigate the formation of first stars from initial collapse of a primordial
gas cloud to formation and growth of protostars. The simulation is integrated
until 0.1 Myrs after the formation of the primary protostar by which the
protostars have already settled onto main sequence stars. This is the first
attempt of simulating first star formation to take into account the ultraviolet
radiative feedback effect by the multiple protostars as well as the three
dimensional effects such as fragmentation of the accretion disk. We find that
the mass accretions onto the population III protostars are significantly
suppressed by the radiative feedback from themselves. As a result, we find five
stars formed in this particular simulation, and that the final mass of the
stars are < 60Msun, including a star of 4.4Msun. Formation of such a star hints
at the existence of even lower-mass stars that would live today.


title: Dipole interactions in doubly-periodic domains

abstract:
  We consider the interactions of finite dipoles in a doubly-periodic domain. A
finite dipole is a pair of equal and opposite strength point vortices separated
by a finite distance. The dynamics of multiple finite dipoles in an unbounded
inviscid uid was first proposed by Tchieu, Kanso & Newton in [1] as a model
that captures the "far- field" hydrodynamic interactions in fish schools. In
this paper, we formulate the equations of motion governing the dynamics of
finite-dipoles in a doubly-periodic domain. We show that a single dipole in a
doubly-periodic domain exhibits periodic and aperiodic behavior, in contrast to
a single dipole in an unbounded domain. In the case of two dipoles in
doubly-periodic domain, we identify a number of interesting trajectories
including collision, collision avoidance, and passive synchronization of the
dipoles. We then examine two types of dipole lattices: rectangular and diamond.
We verify that these lattices are in a state of relative equilibrium and show
that the rectangular lattice is unstable while the diamond lattice is linearly
stable for a range of perturbations. We conclude by commenting on the insights
these models provide in the context of fish schooling.


title: Probing Protein Ensemble Rigidity and Hydrogen-Deuterium exchange

abstract:
  Protein rigidity and flexibility can be analyzed accurately and efficiently
using the program FIRST. Previous studies using FIRST were designed to analyze
the rigidity and flexibility of proteins using a single static (snapshot)
structure. It is however well known that proteins can undergo spontaneous
sub-molecular unfolding and refolding, or conformational dynamics, even under
conditions that strongly favour a well-defined native structure. These (local)
unfolding events result in a large number of conformers that differ from each
other very slightly. In this context, proteins are better represented as a
thermodynamic ensemble of `native-like' structures, and not just as a single
static low-energy structure.
  Working with this notion, we introduce a novel FIRST-based approach for
predicting rigidity/flexibility of the protein ensemble by (i) averaging the
hydrogen bonding strengths from the entire ensemble and (ii) by refining the
mathematical model of hydrogen bonds. Furthermore, we combine our
FIRST-ensemble rigidity predictions with the ensemble solvent accessibility
data of the backbone amides and propose a novel computational method which uses
both rigidity and solvent accessibility for predicting hydrogen-deuterium
exchange (HDX). To validate our predictions, we report a novel site specific
HDX experiment which characterizes the native structural ensemble of
Acylphosphatase from hyperthermophile Sulfolobus solfataricus (Sso AcP).
  The sub-structural conformational dynamics that is observed by HDX data, is
closely matched with the FIRST-ensemble rigidity predictions, which could not
be attained using the traditional single `snapshot' rigidity analysis.
Moreover, the computational predictions of regions that are protected from HDX
and those that undergo exchange are in very good agreement with the
experimental HDX profile of Sso AcP.


title: Limit Models in Metric Abstract Elementary Classes: the Categorical case

abstract:
  We study versions of limit models adapted to the context of *metric abstract
elementary classes*. Under categoricity and superstability-like assumptions, we
generalize some theorems from [GrVaVi]. We prove criteria for existence and
uniqueness of limit models in the metric context.


title: On the Unirationality of del Pezzo surfaces of degree two

abstract:
  Among geometrically rational surfaces, del Pezzo surfaces of degree two over
a field k containing at least one point are arguably the simplest that are not
known to be unirational over k. Looking for k-rational curves on these
surfaces, we extend some earlier work of Manin on this subject. We then focus
on the case where k is a finite field, where we show that all except possibly
three explicit del Pezzo surfaces of degree two are unirational over k.


title: Nonlinear Plasma Wave in Magnetized Plasmas

abstract:
  Nonlinear axisymmetric cylindrical plasma oscillations in magnetized
collisionless plasmas are a model for the electron fluid collapse on the axis
behind an ultrashort relativisically intense laser pulse exciting a plasma wake
wave. We present an analytical description of the strongly nonlinear
oscillations showing that the magnetic field prevents closing of the cavity
formed behind the laser pulse. This effect is demonstrated with 3D PIC
simulations of the laser-plasma interaction. An analysis of the betatron
oscillations of fast electrons in the presence of the magnetic field reveals a
characteristic "Four-Ray Star" pattern which has been observed in the image of
the electron bunch in experiments [T. Hosokai, et al., Phys. Rev. Lett. 97,
075004 (2006)].


title: Approximation Hardness of Graphic TSP on Cubic Graphs

abstract:
  We prove explicit approximation hardness results for the Graphic TSP on cubic
and subcubic graphs as well as the new inapproximability bounds for the
corresponding instances of the (1,2)-TSP. The proof technique uses new modular
constructions of simulating gadgets for the restricted cubic and subcubic
instances. The modular constructions used in the paper could be also of
independent interest.


title:
Quantum mechanics of many particles defined on twisted N-enlarged
  Newton-Hooke space-times

abstract:
  We provide the quantum mechanics of many particles moving in twisted
N-enlarged Newton-Hooke space-time. In particular, we consider the example of
such noncommutative system - the set of M particles moving in Coulomb field of
external point-like source and interacting each other also by Coulomb
potential.


title:
Behavior of the Eilenberg-Moore spectral sequence in derived string
  topology

abstract:
  The purpose of this paper is to give applications of the Eilenberg-Moore type
spectral sequence converging to the relative loop homology algebra of a
Gorenstein space, which is introduced in the previous paper due to the authors.
Moreover, it is proved that the spectral sequence is functorial on the category
of simply-connected Poincar\'e duality spaces over a space.


title:
Direct Learning of Sparse Changes in Markov Networks by Density Ratio
  Estimation

abstract:
  We propose a new method for detecting changes in Markov network structure
between two sets of samples. Instead of naively fitting two Markov network
models separately to the two data sets and figuring out their difference, we
\emph{directly} learn the network structure change by estimating the ratio of
Markov network models. This density-ratio formulation naturally allows us to
introduce sparsity in the network structure change, which highly contributes to
enhancing interpretability. Furthermore, computation of the normalization term,
which is a critical bottleneck of the naive approach, can be remarkably
mitigated. We also give the dual formulation of the optimization problem, which
further reduces the computation cost for large-scale Markov networks. Through
experiments, we demonstrate the usefulness of our method.


title: A Note On Galilean Invariants In Semi-Relativistic Electromagnetism

abstract:
  The incompatibility between the Lorentz invariance of classical
electromagnetism and the Galilean invariance of continuum mechanics is one of
the major barriers to prevent two theories from merging. In this note, a
systematic approach of obtaining Galilean invariant field variables and
equations of electromagnetism within the semi-relativistic limit is reviewed
and extended. In particular, the Galilean invariant forms of Poynting's theorem
and the momentum identity, two most important electromagnetic identities in the
thermomechanical theory of continua, are presented. In this note, we also
introduce two frequently used stronger limits, namely the magnetic and the
electric limit. The reduction of Galilean invariant variables and equations
within these stronger limits are discussed.


title: Variable energy flux in quasi-static magnetohydrodynamic turbulence

abstract:
  Experiments and numerical simulations show that the energy spectrum of the
magnetohydrodynamic turbulence in the quasi-static limit deviates from
Kolmogorov's $k^{-5/3}$ spectrum as the external magnetic field, or
equivalently the interaction parameter, is increased. To explain this
phenomena, we construct an analytical turbulence model with variable energy
flux that arises due to the Lorentz-force induced dissipation. The energy
spectra computed using our model for various interaction parameters are in
qualitative agreement with earlier experimental and numerical results.


title: Bertrand Networks

abstract:
  We study scenarios where multiple sellers of a homogeneous good compete on
prices, where each seller can only sell to some subset of the buyers.
Crucially, sellers cannot price-discriminate between buyers. We model the
structure of the competition by a graph (or hyper-graph), with nodes
representing the sellers and edges representing populations of buyers. We study
equilibria in the game between the sellers, prove that they always exist, and
present various structural, quantitative, and computational results about them.
We also analyze the equilibria completely for a few cases. Many questions are
left open.


title: Pulse to pulse flux density modulation from pulsars at 8.35 GHz

abstract:
  Aims. To investigate the flux density modulation from pulsars and the
existence of specific behaviour of modulation index versus frequency. Methods.
Several pulsars have been observed with the Effelsberg radio telescope at 8.35
GHz. Their flux density time series have been corrected for interstellar
scintillation effects. Results. We present the measurement of modulation
indices for 8 pulsars. We confirm the presence of a critical frequency at ~1
GHz for these pulsars (including 3 new ones from this study). We derived
intrinsic modulation indices for the resulting flux density time series. Our
data analysis revealed strong single pulses detected from 5 pulsars.


title: Dynamo in Protostar

abstract:
  In this paper, we estimate the magnetic Reynolds number of a typical
protostar before and after deuterium burning, and claim for the existence of
dynamo process in both the phases, because the magnetic Reynolds number of the
protostar far exceeds the critical magnetic Reynolds number for dynamo action.
Using the equipartition of kinetic and magnetic energies, we estimate the
steady-state magnetic field of the protostar to be of the order of kilo-gauss,
which is in good agreement with observations.


title: A New Trusted and E-Commerce Architecture for Cloud Computing

abstract:
  Cloud computing platform gives people the opportunity for sharing resources,
services and information among the people of the whole world. In private cloud
system, information is shared among the persons who are in that cloud.
Presently, different types of internet based systems are running in Cloud
Computing environment. E-commerce is one of them. Present models are not
secured enough for executing e-transactions easily, especially in cloud
platform. Again, most of the time, clients fail to distinguish between the good
online business companies and the bad one, which discourages clients and
companies to migrate in cloud. In this paper, we have proposed a newer
e-commerce architecture depends on encryption based secured and fuzzy logic
based certain trust model which will be helpful to solve present e-commerce
problems. We had discussed about the whole working procedure of the model in
this paper. Finally, at the end of this paper, we have discussed some
experimental results about our proposed model which will help to show the
validity of our model.


title:
Inference and learning in probabilistic logic programs using weighted
  Boolean formulas

abstract:
  Probabilistic logic programs are logic programs in which some of the facts
are annotated with probabilities. This paper investigates how classical
inference and learning tasks known from the graphical model community can be
tackled for probabilistic logic programs. Several such tasks such as computing
the marginals given evidence and learning from (partial) interpretations have
not really been addressed for probabilistic logic programs before.
  The first contribution of this paper is a suite of efficient algorithms for
various inference tasks. It is based on a conversion of the program and the
queries and evidence to a weighted Boolean formula. This allows us to reduce
the inference tasks to well-studied tasks such as weighted model counting,
which can be solved using state-of-the-art methods known from the graphical
model and knowledge compilation literature. The second contribution is an
algorithm for parameter estimation in the learning from interpretations
setting. The algorithm employs Expectation Maximization, and is built on top of
the developed inference algorithms.
  The proposed approach is experimentally evaluated. The results show that the
inference algorithms improve upon the state-of-the-art in probabilistic logic
programming and that it is indeed possible to learn the parameters of a
probabilistic logic program from interpretations.


title:
Nonlinear-optical up and down frequency-converting backward-wave
  metasensors and metamirrors

abstract:
  A concept of a family of unique backward-wave photonic devices, such as
frequency up and down converting nonlinear-optical mirrors, sensors,
modulators, filters and amplifiers is proposed. Novel materials are considered,
which support coexistence of ordinary and backward waves and thus enable
enhanced nonlinear-optical frequency-conversion processes. Particular
properties of short-pulse regime are investigated.


title: On discrete projective transformation groups of Riemannian manifolds

abstract:
  We prove rigidity facts for groups acting on pseudo-Riemannian manifolds by
preserving unparameterized geodesics.


title:
The Compressed Annotation Matrix: an Efficient Data Structure for
  Computing Persistent Cohomology

abstract:
  The persistent homology with coefficients in a field F coincides with the
same for cohomology because of duality. We propose an implementation of a
recently introduced algorithm for persistent cohomology that attaches
annotation vectors with the simplices. We separate the representation of the
simplicial complex from the representation of the cohomology groups, and
introduce a new data structure for maintaining the annotation matrix, which is
more compact and reduces substancially the amount of matrix operations. In
addition, we propose heuristics to simplify further the representation of the
cohomology groups and improve both time and space complexities. The paper
provides a theoretical analysis, as well as a detailed experimental study of
our implementation and comparison with state-of-the-art software for persistent
homology and cohomology.


title: Turbulence for the generalised Burgers equation

abstract:
  In this survey, we review the results on turbulence for the generalised
Burgers equation on the circle: u_t+f'(u)u_x=\nu u_{xx}+\eta,\ x \in S^1=\R/\Z,
obtained by A.Biryuk and the author in \cite{Bir01,BorK,BorW,BorD}. Here, f is
smooth and strongly convex, whereas the constant 0<\nu << 1 corresponds to a
viscosity coefficient. We will consider both the case \eta=0 and the case when
\eta is a random force which is smooth in x and irregular (kick or white noise)
in t. In both cases, sharp bounds for Sobolev norms of u averaged in time and
in ensemble of the type C \nu^{-\delta}, \delta>=0, with the same value of
\delta for upper and lower bounds, are obtained. These results yield sharp
bounds for small-scale quantities characterising turbulence, confirming the
physical predictions \cite{BK07}.


title:
Quantum Implemention of an LTI System with the minimal number of
  additional quantum noise inputs

abstract:
  Physical Realizability addresses the question of whether it is possible to
implement a given LTI system as a quantum system. It is in general not true
that a given synthesized quantum controller described by a set of stochastic
differential equations is equivalent to some physically meaningful quantum
system. However, if additional quantum noises are permitted in the
implementation it is always possible to implement an arbitrary LTI system as a
quantum system. In this paper we give an expression for the exact number of
noises required to implement a given LTI system as a quantum system.
Furthermore, we focus our attention on proving that this is a minimum, that is,
it is not possible to implement the system as a quantum system with a smaller
number of additional quantum noises.


Boundedness and blow-up of solutions for a nonlinear elliptic system
  arising in probability and stochastic processes


title: Artificial magnetism and magnetoelectric coupling from dielectric layers

abstract:
  We investigate a high-order homogenization (HOH) algorithm for periodic
multilayered stacks. The mathematical tool of choice is a transfer matrix
method. Expressions for effective permeability, permittivity and
magnetoelectric coupling are explored by frequency power expansions. On the
physical side, this high-order homogenization uncovers a magnetoelectric
coupling effect (odd order approximation) and artificial magnetism (even order
approximation) in moderate contrast photonic crystals. Comparing the effective
parameters' expressions of a stack with three layers against that of a stack
with two layers, we note that the magnetoelectric coupling effect vanishes
while the artificial magnetism can still be achieved in a center symmetric
periodic structure. Furthermore, we numerically check the effective parameters
through the dispersion law and transmission curves of a stack with two
dielectric layers against that of an effective bianisotropic medium: they
present a good agreement in the low frequency (acoustic) band until the first
stop band, where the analyticity of the logarithm function of transfer matrix
($\log\{T\}$) breaks down.


title:
Rayleigh waves in anisotropic crystals rotating about the normal to a
  symmetry plane

abstract:
  The propagation of surface acoustic waves in a rotating anisotropic crystal
is studied. The crystal is monoclinic and cut along a plane containing the
normal to the symmetry plane; this normal is also the axis of rotation. The
secular equation is obtained explicitly using the "method of the polarization
vector", and it shows that the wave is dispersive and decelerates with
increasing rotation rate. The case of orthorhombic symmetry is also treated.
The surface wave speed is computed for 12 monoclinic and 8 rhombic crystals,
and for a large range of the rotation rate/wave frequency ratio.


title: A Fokker-Planck description for the queue dynamics of large tick stocks

abstract:
  Motivated by empirical data, we develop a statistical description of the
queue dynamics for large tick assets based on a two-dimensional Fokker-Planck
(diffusion) equation, that explicitly includes state dependence, i.e. the fact
that the drift and diffusion depends on the volume present on both sides of the
spread. "Jump" events, corresponding to sudden changes of the best limit price,
must also be included as birth-death terms in the Fokker-Planck equation. All
quantities involved in the equation can be calibrated using high-frequency data
on best quotes. One of our central finding is the the dynamical process is
approximately scale invariant, i.e., the only relevant variable is the ratio of
the current volume in the queue to its average value. While the latter shows
intraday seasonalities and strong variability across stocks and time periods,
the dynamics of the rescaled volumes is universal. In terms of rescaled
volumes, we found that the drift has a complex two-dimensional structure, which
is a sum of a gradient contribution and a rotational contribution, both stable
across stocks and time. This drift term is entirely responsible for the
dynamical correlations between the ask queue and the bid queue.


title:
Fragmentation and dynamical collapse of the starless high-mass
  star-forming region IRDC18310-4

abstract:
  Aims: We study the fragmentation and dynamical properties of a massive
starless gas clump at the onset of high-mass star formation. Methods: Based on
Herschel continuum data we identify a massive gas clump that remains
far-infrared dark up to 100mum wavelengths. The fragmentation and dynamical
properties are investigated by means of Plateau de Bure Interferometer and
Nobeyama 45m single-dish spectral line and continuum observations. Results: The
massive gas reservoir fragments at spatial scales of ~18000AU in four cores.
Comparing the spatial extent of this high-mass region with intermediate- to
low-mass starless cores from the literature, we find that linear sizes do not
vary significantly over the whole mass regime. However, the high-mass regions
squeeze much more gas into these similar volumes and hence have orders of
magnitude larger densities. The fragmentation properties of the presented
low-to high-mass regions are consistent with gravitational instable Jeans
fragmentation. Furthermore, we find multiple velocity components associated
with the resolved cores. Recent radiative transfer hydrodynamic simulations of
the dynamic collapse of massive gas clumps also result in multiple velocity
components along the line of sight because of the clumpy structure of the
regions. This result is supported by a ratio between viral and total gas mass
for the whole region <1. Conclusions: This apparently still starless high-mass
gas clump exhibits clear signatures of early fragmentation and dynamic collapse
prior to the formation of an embedded heating source. A comparison with regions
of lower mass reveals that the linear size of star-forming regions does not
necessarily have to vary much for different masses, however, the mass
reservoirs and gas densities are orders of magnitude enhanced for high-mass
regions compared to their lower-mass siblings.


title: AdS black holes, the bulk-boundary dictionary, and smearing functions

abstract:
  In Lorentzian AdS/CFT there exists a mapping between local bulk operators and
nonlocal CFT operators. In global AdS this mapping can be found through use of
bulk equations of motion and allows the nonlocal CFT operator to be expressed
as a local operator smeared over a range of positions and times. We argue that
such a construction is not possible if there are bulk normal modes with
exponentially small near boundary imprint. We show that the AdS-Schwarzschild
background is such a case, with the horizon introducing modes with angular
momentum much larger than frequency, causing them to be trapped by the
centrifugal barrier. More generally, we argue that any barrier in the radial
effective potential which prevents null geodesics from reaching the boundary
will lead to modes with vanishingly small near boundary imprint, thereby
obstructing the existence of a smearing function. While one may have thought
the bulk-boundary dictionary for low curvature regions, such as the exterior of
a black hole, should be as in empty AdS, our results demonstrate otherwise.


title:
On Design of Opportunistic Spectrum Access in the Presence of Reactive
  Primary Users

abstract:
  Opportunistic spectrum access (OSA) is a key technique enabling the secondary
users (SUs) in a cognitive radio (CR) network to transmit over the "spectrum
holes" unoccupied by the primary users (PUs). In this paper, we focus on the
OSA design in the presence of reactive PUs, where PU's access probability in a
given channel is related to SU's past access decisions. We model the channel
occupancy of the reactive PU as a 4-state discrete-time Markov chain. We
formulate the optimal OSA design for SU throughput maximization as a
constrained finite-horizon partially observable Markov decision process (POMDP)
problem. We solve this problem by first considering the conventional short-term
conditional collision probability (SCCP) constraint. We then adopt a long-term
PU throughput (LPUT) constraint to effectively protect the reactive PU
transmission. We derive the structure of the optimal OSA policy under the LPUT
constraint and propose a suboptimal policy with lower complexity. Numerical
results are provided to validate the proposed studies, which reveal some
interesting new tradeoffs between SU throughput maximization and PU
transmission protection in a practical interaction scenario.


title:
Initial condition from the action principle and its application to
  cosmology and to false vacuum bubbles

abstract:
  We study models where the gauge coupling constants, masses, etc are functions
of some conserved charge in the universe. We first consider the standard Dirac
action, but where the mass and the electromagnetic coupling constant are a
function of the charge in the universe and afterwards extend this scalar
fields. For Dirac field in the flat space formulation, the formalism is not
manifestly Lorentz invariant, however Lorentz invariance can be restored by
performing a phase transformation of the Dirac field. In the case where scalar
field are considered, there is the new feature that an initial condition for
the scalar field is derived from the action. In the case of the Higgs field,
the initial condition require, that the universe be at the false vacuum state
at a certain time slice, which is quite important for inflation scenarios. Also
false vacuum branes will be studied in a similar approach. We discuss also the
use of "spoiling terms", that violate gauge invariant to introduce these
initial condition.


title:
Transonic solutions of isothermal galactic winds in a cold dark matter
  halo

abstract:
  We study fundamental properties of steady, spherically symmetric, isothermal
galactic outflow in appropriate gravitational potential models. We aim at
constructing a universal scale free theory not only for galactic winds, but
also for winds from clusters/groups of galaxies. In particular, we consider
effects of mass-density distribution on the formation of transonic galactic
outflows under several models of the density distribution profile predicted by
cosmological simulations of structure formation based on the cold dark matter
(CDM) scenario. In this study, we have clarified that there exists two types of
transonic solutions: outflows from the central region and from distant region
with a finite radius, depending upon the density distribution of the system.
The system with sufficiently steep density gradient at the center is allowed to
have the transonic outflows from the center. The resultant criterion
intriguingly indicates that the density gradient at the center must be steeper
than that of the prediction of conventional CDM model including Navarro, Frenk
& White (1997) and Moore et al. (1999). This result suggests that an additional
steeper density distribution originated by baryonic systems such as the stellar
component and/or the central massive black hole is required to realize
transonic outflow from the central region. On the other hand, we predict the
outflow, which is started at the outskirts of the galactic center and is
slowly-accelerated without any drastic energy injection like starburst events.
These transonic outflows may contribute secularly to the metal enrichment of
the intergalactic medium.


title:
Multilevel Preconditioner with Stable Coarse Grid Corrections for the
  Helmholtz Equation

abstract:
  In this paper we consider a class of robust multilevel precontioners for the
Helmholtz equation with high wave number. The key idea in this work is to use
the continuous interior penalty finite element methods (CIP-FEM) studied in
\cite{Wu12,Wu12-hp} to construct the stable coarse grid correction problems.
The multilevel methods, based on GMRES smoothing on coarse grids, are then
served as a preconditioner in the outer GMRES iteration. In the one dimensional
case, convergence property of the modified multilevel methods is analyzed by
the local Fourier analysis. From our numerical results, we find that the
proposed methods are efficient for a reasonable range of frequencies. The
performance of the algorithms depends relatively mildly on wave number. In
particular, only one GMRES smoothing step may guarantee the optimal convergence
of our multilevel algorithm, which remedies the shortcoming of the multilevel
algorithm in \cite{EEO01}.


title:
Explicit secular equations for piezoacoustic surface waves:
  Shear-Horizontal modes

abstract:
  Attention is given to surface waves of shear-horizontal modes in
piezoelectric crystals permitting the decoupling between an elastic in-plane
Rayleigh wave and a piezoacoustic anti-plane Bleustein-Gulyaev wave.
Specifically, the crystals possess $\bar{4}$ symmetry (inclusive of
$\bar{4}2$m, $\bar{4}3$m, and 23 classes) and the boundary is any plane
containing the normal to a symmetry plane (rotated $Y$-cuts about the $Z$
axis). The secular equation is obtained explicitly as a polynomial not only for
the metallized boundary condition but, in contrast to previous studies on the
subject, also for other types of boundary conditions. For the metallized
surface problem, the secular equation is a quadratic in the squared wave speed;
for the un-metallized surface problem, it is a sextic in the squared wave
speed; for the thin conducting boundary problem, it is of degree 16 in the
speed. The relevant root of the secular equation can be identified and the
complete solution is then found (attenuation factors, field profiles, etc.).
The influences of the cut angle and of the conductance of the adjoining medium
are illustrated numerically for GaAs ($\bar{4}3$m), BaLaGa$_3$O$_7$
($\bar{4}2$m) and Bi$_{12}$GeO$_{20}$ (23). Indications are given on how to
apply the method to crystals with 222 symmetry.


title: Quantum State Tomography via Linear Regression Estimation

abstract:
  A simple yet efficient method of linear regression estimation (LRE) is
presented for quantum state tomography. In this method, quantum state
reconstruction is converted into a parameter estimation problem of a linear
regression model and the least-squares method is employed to estimate the
unknown parameters. The asymptotic mean squared error (MSE) bound of the
estimate can be given analytically, which can guide one to choose optimal
measurement sets. The LRE is asymptotically optimal in the sense that the MSE
may achieve the Cram\'{e}r-Rao bound asymptotically. The computational
complexity of LRE is O(d^4), where d is the dimension of the quantum state.
Numerical examples show that LRE is much faster than maximum-likelihood
estimation for quantum state tomography.


title: Kondo screening by the surface modes of a strong topological insulator

abstract:
  We consider a magnetic impurity deposited on the surface of a strong
topological insulator and interacting with the surface modes by a Kondo
exchange interaction. Taking into account the warping of the Fermi line of the
surface modes, we derive a mapping to an effective one dimensional model and
show that the impurity is fully screened by the surface electrons except when
the Fermi level lies exactly at the Dirac point. Using an Abrikosov fermion
mean-field theory, we calculate the shape of the electronic density Friedel
oscillation resulting from the presence of the Kondo screening cloud. We
analyze quantitatively the observability of a six-fold symmetry in the Friedel
oscillations for two prototype compounds: Bi$_2$Se$_3$ and Bi$_2$Te$_3$.


title:
Tension, rigidity and preferential curvature of interfaces between
  coexisting polymer solutions

abstract:
  The properties of the interface in a phase-separated solution of polymers
with different degrees of polymerization and Kuhn segment lengths are
calculated. The starting point is the planar interface, the profile of which is
calculated in the so-called 'blob model', which incorporates the solvent in an
implicit way. The next step is the study of a metastable droplet phase formed
by imposing a chemical potential different from that at coexistence. The
pressure difference across the curved interface, which corresponds to this
higher chemical potential, is used to calculate the curvature properties of the
droplet. Interfacial tensions, Tolman lengths and rigidities are calculated and
used for predictions for a realistic experimental case. The results suggest
that interfaces between phase-separated solutions of polymers exhibit, in
general, a preferential curvature, which stabilizes droplets of low molecular
mass polymer in a high molecular mass macroscopic phase.


title:
Multi-dimensional potential energy surfaces and non-axial octupole
  correlations in actinide and transfermium nuclei from relativistic mean field
  models

abstract:
  We have developed multi-dimensional constrained covariant density functional
theories (MDC-CDFT) for finite nuclei in which the shape degrees of freedom
\beta_{\lambda\mu} with even \mu, e.g., \beta_{20}, \beta_{22}, \beta_{30},
\beta_{32}, \beta_{40}, etc., can be described simultaneously. The functional
can be one of the following four forms: the meson exchange or point-coupling
nucleon interactions combined with the non-linear or density-dependent
couplings. For the pp channel, either the BCS approach or the Bogoliubov
transformation is implemented. The MDC-CDFTs with the BCS approach for the
pairing (in the following labelled as MDC-RMF models with RMF standing for
"relativistic mean field") have been applied to investigate multi-dimensional
potential energy surfaces and the non-axial octupole $Y_{32}$-correlations in
N=150 isotones. In this contribution we present briefly the formalism of
MDC-RMF models and some results from these models. The potential energy
surfaces with and without triaxial deformations are compared and it is found
that the triaxiality plays an important role upon the second fission barriers
of actinide nuclei. In the study of Y_{32}-correlations in N=150 isotones, it
is found that, for 248Cf and 250Fm, \beta_{32} > 0.03 and the energy is lowered
by the \beta_{32} distortion by more than 300 keV; while for 246Cm and 252No,
the pocket with respect to \beta_{32} is quite shallow.


title: Dynamic structure function of a cold Fermi gas at unitarity

abstract:
  We present a theoretical study of the dynamic structure function of a
resonantly interacting two-component Fermi gas at zero temperature. Our
approach is based on dynamic many-body theory able to describe excitations in
strongly correlated Fermi systems. The fixed-node diffusion Monte Carlo method
is used to produce the ground-state correlation functions which are used as an
input for the excitation theory. Our approach reproduces recent Bragg
scattering data in both the density and the spin channel. In the BCS regime,
the response is close to that of the ideal Fermi gas. On the BEC side, the Bose
peak associated with the formation of dimers dominates the density channel of
the dynamic response. When the fraction of dimers is large our theory departs
from the experimental data, mainly in the spin channel.


title:
Polynomial Time Algorithm for Min-Ranks of Graphs with Simple Tree
  Structures

abstract:
  The min-rank of a graph was introduced by Haemers (1978) to bound the Shannon
capacity of a graph. This parameter of a graph has recently gained much more
attention from the research community after the work of Bar-Yossef et al.
(2006). In their paper, it was shown that the min-rank of a graph G
characterizes the optimal scalar linear solution of an instance of the Index
Coding with Side Information (ICSI) problem described by the graph G. It was
shown by Peeters (1996) that computing the min-rank of a general graph is an
NP-hard problem. There are very few known families of graphs whose min-ranks
can be found in polynomial time. In this work, we introduce a new family of
graphs with efficiently computed min-ranks. Specifically, we establish a
polynomial time dynamic programming algorithm to compute the min-ranks of
graphs having simple tree structures. Intuitively, such graphs are obtained by
gluing together, in a tree-like structure, any set of graphs for which the
min-ranks can be determined in polynomial time. A polynomial time algorithm to
recognize such graphs is also proposed.


title:
Adatoms and clusters of 3d transition metals on graphene: Electronic and
  magnetic configurations

abstract:
  We investigate the electronic and magnetic properties of single Fe, Co, and
Ni atoms and clusters on monolayer graphene (MLG) on SiC(0001) by means of
scanning tunneling microscopy (STM), x-ray absorption spectroscopy, x-ray
magnetic circular dichroism (XMCD), and ab initio calculations. STM reveals
different adsorption sites for Ni and Co adatoms. XMCD proves Fe and Co adatoms
to be paramagnetic and to exhibit an out-of-plane easy axis in agreement with
theory. In contrast, we experimentally find a nonmagnetic ground state for Ni
monomers while an increasing cluster size leads to sizeable magnetic moments.
These observations are well reproduced by our calculations and reveal the
importance of hybridization effects and intra-atomic charge transfer for the
properties of adatoms and clusters on MLG.


title:
Stellar substructures in the solar neighbourhood. II. Abundances of
  neutron-capture elements in the kinematic Group 3 of the Geneva-Copenhagen
  survey

abstract:
  The evolution of chemical elements in a galaxy is linked to its star
formation history. Variations in star formation history are imprinted in the
relative abundances of chemical elements produced in different supernova events
and asymptotic giant branch stars. We determine detailed elemental abundances
of s- and r-process elements in stars belonging to Group3 of the
Geneva-Copenhagen survey and compare their chemical composition with Galactic
disc stars. The aim is to look for possible chemical signatures that might give
information about the formation history of this kinematic group of stars, which
is suggested to correspond to remnants of disrupted satellites. High-resolution
spectra were obtained with the FIES spectrograph at the Nordic Optical
Telescope, La Palma, and were analysed with a differential model atmosphere
method. Comparison stars were observed and analysed with the same method.
Abundances of chemical elements produced mainly by the s-process are similar to
those in the Galactic thin-disc dwarfs of the same metallicity, while
abundances of chemical elements produced predominantly by the r-process are
overabundant. The similar elemental abundances are observed in Galactic
thick-disc stars. The chemical composition together with the kinematic
properties and ages of stars in Group3 of the Geneva-Copenhagen survey support
a gas-rich satellite merger scenario as the most likely explanation for the
origin. The similar chemical composition of stars in Group3 and the thick-disc
stars might suggest that their formation histories are linked.


title:
Stringent Tests of Constrained Minimal Flavour Violation through Delta
  F=2 Transitions

abstract:
  New Physics contributions to Delta F=2 transitions in models with constrained
Minimal Flavour Violation (CMFV), are parametrized by a single variable S(v),
the value of the real box diagram function. With already precise experimental
values of epsilon_K, Delta M_d, Delta M_s, CP-asymmetry S_{psi K_S} and of
hat{B}_K entering the evaluation of epsilon_K, the future of CMFV in the Delta
F=2 sector depends crucially on the values of |Vcb|, |Vub|, gamma, F_{B_s}
sqrt{hat B_{B_s}} and F_{B_d} sqrt{hat B_{B_d}}. The ratio xi of the latter two
parameters, rather precisely determined from lattice calculations, allows then
together with Delta M_s/Delta M_d and S_{psi K_S} to determine the range of
gamma in the unitarity triangle independently of the value of S(v). Imposing in
addition the constraints from epsilon_K and Delta M_d allows to determine the
favorite CMFV values of |Vcb|, |Vub|, F_{B_s} sqrt{hat B_{B_s}} and F_{B_d}
sqrt{hat B_{B_d}} as functions of S(v) and gamma. The |Vcb|^4 dependence of
epsilon_K allows to determine |Vcb| for a given S(v) and gamma with a higher
precision than it is presently possible using tree-level decays. The same
applies to |Vub|, |Vtd| and |Vts| that are automatically determined as
functions of S(v) and gamma. Typically F_{B_s}sqrt{hat B_{B_s}} and F_{B_d}
sqrt{hat B_{B_d}} have to be significantly lower than their present lattice
values, while |Vcb| has to be significantly higher than its tree-level
determination. The region in the space of these three parameters allowed by
CMFV indicates visible problems in this class of models and hints for the
presence of new sources of flavour violation and/or new local operators in
Delta F=2 data that are strongly suppressed in these models. As a byproduct we
propose to reduce the present uncertainty in the charm contribution toepsilon_K
by using the experimental value of Delta M_K.


title:
Variational Assimilation for Xenon Dynamical Forecasts in Neutronic
  using Advanced Background Error Covariance Matrix

abstract:
  Data assimilation method consists in combining all available pieces of
information about a system to obtain optimal estimates of initial states. The
different sources of information are weighted according to their accuracy by
the means of error covariance matrices. Our purpose here is to evaluate the
efficiency of variational data assimilation for the xenon induced oscillations
forecasts in nuclear cores. In this paper we focus on the comparison between
3DVAR schemes with optimised background error covariance matrix B and a 4DVAR
scheme. Tests were made in twin experiments using a simulation code which
implements a mono-dimensional coupled model of xenon dynamics, thermal, and
thermal-hydraulic processes. We enlighten the very good efficiency of the 4DVAR
scheme as well as good results with the 3DVAR one using a careful multivariate
modelling of B.


title:
Properties of Odd-Frequency Superconductivity in Antiferromagnetic
  Ordered State

abstract:
  We investigate properties below T_c of odd-frequency pairing which is
realized by antiferromagnetic critical spin fluctuations or spin wave modes. It
is shown that \Delta(\epsilon_n) becomes maximum at finite \epsilon_n, and
\Delta(\pi T) becomes maximum at finite T. Implications of the present results
to the experimental results of CeCu_2Si_2 and CeRhIn_5 are given.


title: On additive complement of a finite set

abstract:
  We say the sets of nonnegative integers A and B are additive complements if
their sum contains all sufficiently large integers. In this paper we prove a
conjecture of Chen and Fang about additive complement of a finite set.


title: Cored Hypergraphs, Power Hypergraphs and Their Laplacian H-Eigenvalues

abstract:
  In this paper, we introduce the class of cored hypergraphs and power
hypergraphs, and investigate the properties of their Laplacian H-eigenvalues.
From an ordinary graph, one may generate a $k$-uniform hypergraph, called the
$k$th power hypergraph of that graph. Power hypergraphs are cored hypergraphs,
but not vice versa. Hyperstars, hypercycles, hyperpaths are special cases of
power hypergraphs, while sunflowers are a subclass of cored hypergraphs, but
not power graphs in general. We show that the largest Laplacian H-eigenvalue of
an even-uniform cored hypergraph is equal to its largest signless Laplacian
H-eigenvalue. Especially, we find out these largest H-eigenvalues for
even-uniform sunflowers. Moreover, we show that the largest Laplacian
H-eigenvalue of an odd-uniform sunflower, hypercycle and hyperpath is equal to
the maximum degree, i.e., 2. We also compute out the H-spectra of the class of
hyperstars. When $k$ is odd, the H-spectra of the hypercycle of size 3 and the
hyperpath of length 3 are characterized as well.


title: Group Classification of a Generalized Black--Scholes--Merton Equation

abstract:
  The complete group classification of a generalization of the
Black-Scholes-Merton model is carried out by making use of the underlying
equivalence and additional equivalence transformations. For each non linear
case obtained through this classification, invariant solutions are given. To
that end, two boundary conditions of financial interest are considered, the
terminal and the barrier option conditions.


title:
BEER analysis of Kepler and CoRoT light curves: I. Discovery of
  Kepler-76b: A hot Jupiter with evidence for superrotation

abstract:
  We present the first case in which the BEER algorithm identified a hot
Jupiter in the Kepler light curve, and its reality was confirmed by orbital
solutions based on follow-up spectroscopy. The companion Kepler-76b was
identified by the BEER algorithm, which detected the BEaming (sometimes called
Doppler boosting) effect together with the Ellipsoidal and Reflection/emission
modulations (BEER), at an orbital period of 1.54 days, suggesting a planetary
companion orbiting the 13.3 mag F star. Further investigation revealed that
this star appeared in the Kepler eclipsing binary catalog with estimated
primary and secondary eclipse depths of 5e-3 and 1e-4 respectively.
Spectroscopic radial-velocity follow-up observations with TRES and SOPHIE
confirmed Kepler-76b as a transiting 2.0+/-0.26 Mjup hot Jupiter. The mass of a
transiting planet can be estimated from either the beaming or the ellipsoidal
amplitude. The ellipsoidal-based mass estimate of Kepler-76b is consistent with
the spectroscopically measured mass while the beaming-based estimate is
significantly inflated. We explain this apparent discrepancy as evidence for
the superrotation phenomenon, which involves eastward displacement of the
hottest atmospheric spot of a tidally-locked planet by an equatorial
super-rotating jet stream. This phenomenon was previously observed only for HD
189733b in the infrared. We show that a phase shift of 10.3+/-2.0 degrees of
the planet reflection/emission modulation, due to superrotation, explains the
apparently inflated beaming modulation, resolving the ellipsoidal/beaming
amplitude discrepancy. Kepler-76b is one of very few confirmed planets in the
Kepler light curves that show BEER modulations and the first to show
superrotation evidence in the Kepler band. Its discovery illustrates for the
first time the ability of the BEER algorithm to detect short-period planets and
brown dwarfs.


title:
Radiation reaction from QED: lightfront perturbation theory in a plane
  wave background

abstract:
  We derive dynamical, real time radiation reaction effects from lightfront
QED. Combining the Hamiltonian formalism with a plane wave background field,
the calculation is performed in the Furry picture for which the background is
treated exactly while interactions between quantum fields are treated in
perturbation theory as normal. We work to a fixed order in perturbation theory,
but no other approximation is made. The literature contains many proposals for
the correct classical equation describing a radiating particle; we take the
classical limit of our results and identify which equations are consistent with
QED.


title: L2-invisibility and a class of local similarity groups

abstract:
  In this note we show that the members of a certain class of local similarity
groups are l2-invisible, i.e. the non-reduced group homology of the regular
unitary representation vanishes in all degrees. This class contains for example
Thompson's group V and Nekrashevych-R\"over groups. They yield counterexamples
to a generalized zero-in-the-spectrum conjecture for groups that admit a
classifying space with finitely many cells in each dimension.


title: A ballistic pn junction in suspended graphene with split bottom gates

abstract:
  We have developed a process to fabricate suspended graphene devices with
local bottom gates, and tested it by realizing electrostatically controlled pn
junctions on a suspended graphene mono-layer nearly 2 micrometers long.
Measurements as a function of gate voltage, magnetic field, bias, and
temperature exhibit characteristic Fabry-Perot oscillations in the cavities
formed by the pn junction and each of the contacts, with transport occurring in
the ballistic regime. Our results demonstrate the possibility to achieve a high
degree of control on the local electronic properties of ultra-clean suspended
graphene layers, a key aspect for the realization of new graphene
nanostructures.


title:
Solving the Schr\"odinger eigenvalue problem by the imaginary time
  propagation technique using splitting methods with complex coefficients

abstract:
  The Schr\"odinger eigenvalue problem is solved with the imaginary time
propagation technique. The separability of the Hamiltonian makes the problem
suitable for the application of splitting methods. High order fractional time
steps of order greater than two necessarily have negative steps and can not be
used for this class of diffusive problems. However, there exist methods which
use fractional complex time steps with positive real parts which can be used
with only a moderate increase in the computational cost. We analyze the
performance of this class of schemes and propose new methods which outperform
the existing ones in most cases. On the other hand, if the gradient of the
potential is available, methods up to fourth order with real and positive
coefficients exist. We also explore this case and propose new methods as well
as sixth-order methods with complex coefficients. In particular, highly
optimized sixth-order schemes for near integrable systems using positive real
part complex coefficients with and without modified potentials are presented. A
time-stepping variable order algorithm is proposed and numerical results show
the enhanced efficiency of the new methods.


title: Time-independent pricing of options in range bound markets

abstract:
  Assuming that price of the underlying stock is moving in range bound, the
Black-Scholes formula for options pricing supports a separation of variables.
The resulting time-independent equation is solved employing different behavior
of the option price function and three significant results are deduced. The
first is the probability of stock price penetration through support or
resistance level, called transmission coefficient. The second is the distance
that price will go through once stock price penetrates out of the range bound.
The last one is a predicted short time dramatic fall in the stock volatility
right ahead of price tunneling. All three results are useful tools that give
market practitioners valuable insights in choosing the right time to get
involved in an option contract, about how far the price will go in case of a
breakout, and how to correctly interpret volatility downfalls.


title: Quantitative ergodic theorems and their number-theoretic applications

abstract:
  We present a survey of ergodic theorems for actions of algebraic and
arithmetic groups recently established by the authors, as well as some of their
applications. Our approach is based on spectral methods employing the unitary
representation theory of the groups involved. This allows the derivation of
ergodic theorems with a rate of convergence, an important phenomenon which does
not arise in classical ergodic theory. Quantitative ergodic theorems give rise
to new and previously inaccessible applications, and we demonstrate the
remarkable diversity of such applications by presenting several
number-theoretic results. These include, in particular, general uniform error
estimates in lattice points counting problems, explicit estimates in sifting
problems for almost-prime points on symmetric varieties, bounds for exponents
of intrinsic Diophantine approximation, and results on fast distribution of
dense orbits on homogeneous spaces.


title: Additivity and lineability in vector spaces

abstract:
  G\'amez-Merino, Munoz-Fern\'andez and Seoane-Sep\'ulveda proved that if
additivity $\mathcal A(\mathcal F)>\mathfrak c$, then $\mathcal F$ is $\mathcal
A(\mathcal F)$-lineable where $\mathcal F\subseteq\mathbb R^\mathbb R$. They
asked if $\mathcal A(\mathcal F)>\mathfrak c$ can be weakened. We answer this
question in negative. Moreover, we introduce and study the notions of
homogeneous lineability number and lineability number of subsets of linear
spaces.


title: Hann-Banach-Arveson extension theorem and Kadison isomorphism

abstract:
  Let $C^*(\cls)$ be the $C^*$ algebra generated by an operator system $\cls$
i.e. a unital $*$-closed subspace of a unital $C^*$ algebra $\cla$. We prove
that any complete order isomorphism $\cli:\cls \raro \cls'$ between two such
operator systems of matrix algebras has a unique extension to a
$C^*$-isomorphism $\cli:C^*(\cls) \raro C^*(\cls')$. However, the same
statement with more general operator systems of infinite dimensional
$C^*$-algebra is false. As an application of this result, we characterise upto
cocycle conjugacy the extreme points of unital completely positive maps on
matrix algebra.


title: Photoproduction of rho0 in ultra--peripheral nuclear collisions at ALICE

abstract:
  Photoproduction of $\rho^0$ mesons in ultra-peripheral Pb+Pb collisions has
been studied by the ALICE Collaboration at the CERN LHC. The strong photon flux
associated with relativistic charged nuclei leads to a very large cross section
for exclusive photoproduction of $\rho^0$ meson in interactions of the type $Pb
+ Pb \rightarrow Pb + Pb + \rho^0$. For a $\rho^0$ produced at mid-rapidity at
the LHC, the photon-nucleus center of mass energy is higher than in any
previous experiment.
  The ALICE detector is a general purpose detector dedicated to study
heavy--ion collisions. ALICE has excellent performance in the low $p_T$ region,
and can reconstruct charged particle tracks with 0.1 GeV/c $\leq p_T \leq 100$
GeV/c. In this analysis all tracks were required to be within ALICE's central
barrel. Analysis of data from the first heavy ion run at the LHC in 2010 will
be discussed in this paper.


title:
A criterion for good reduction of Drinfeld modules and Anderson motives
  in terms of local shtukas

abstract:
  For an Anderson A-motive over a discretely valued field whose residue field
has A-characteristic \epsilon, we prove a criterion for good reduction in terms
of its associated local shtuka at \epsilon. This yields a criterion for good
reduction of Drinfeld modules. Our criterion is the function-field analog of
Grothendieck's and de Jong's criterion for good reduction of an abelian variety
over a discretely valued field with residue characteristic p in terms of its
associated p-divisible group.


title: Study of Failed CME Core Associated with Asymmetric Filament Eruption

abstract:
  We present the multi-wavelength observations of asymmetric filament eruption,
associated CME and coronal downflows on 2012 June 17-18 during 20:00-05:00 UT.
We use SDO/AIA, STEREO-B/SECCHI observations to understand the filament
eruption scenario and its kinematics. While LASCO C2 observations have been
analyzed to study the kinematics of the CME and associated downflows. SDO/AIA
limb observations show that the filament exhibits whipping like asymmetric
eruption. STEREO/EUVI disk observations reveal a two ribbon flare underneath
the south-eastern part of the filament that is most probably occurred due to
reconnection process in the coronal magnetic field in the wake of the filament
eruption. The whipping like filament eruption later gives a slow CME in which
the leading edge and the core propagate respectively with the average speed of
$\approx$ 540 km s$^{-1}$ and $\approx$ 126 km s$^{-1}$ as observed in the
LASCO C2 coronagraph. The CME core formed by the eruptive flux-rope shows the
outer coronal downflows with the average speed of $\approx$ 56 km s$^{-1}$
after reaching up to $\approx$4.33 $R_{\sun}$. Initially, the core decelerates
with $\approx$ 48 m s$^{-2}$. The plasma first decelerates gradually up to the
height of $\approx$4.33 $ R_{\sun}$ and then starts accelerating downward. We
suggest a self-consistent model of a magnetic flux rope representing the
magnetic structure of the CME core formed by eruptive filament that lost its
previous stable equilibrium when reach at a critical height. With some
reasonable parameters, and inherent physical conditions the model describes the
non-radial ascending motion of the flux rope in the corona, its stopping at
some height, and thereafter the downward motion, which are in good agreement
with the observations.


title:
Some estimates for imaginary powers of the Laplace operator in variable
  Lebesgue spaces and applications

abstract:
  In this paper we study some estimates of norms in variable exponent Lebesgue
spaces for a singular integral operators that are imaginary powers of the
Laplace operator in $\R^n$. Using Mellin transform argument, from this
estimates we obtain boundedness for a family of maximal operators in variable
exponent Lebesgue spaces, which are closely related to the (weak) solution of
the wave equation.42B25, 42B20, 46E30, 44A10, 42B10, 35L05


title: A categorical description of Bass-Serre theory

abstract:
  Self-similar group actions may be encoded by a class of left cancellative
monoids called left Rees monoids, a result obtained by combining pioneering
work by Perrot with later work by the first author. Left Rees monoids that are
also right cancellative are called Rees monoids. Irreducible Rees monoids have
the striking property that they are embedded in their universal groups and
these universal groups are HNN extensions by a single stable letter. In this
paper, we generalize the above theory from monoids to categories. We study the
structure of left Rees categories and prove that Rees categories embed into
their universal groups. Furthermore, we show that from each graph of groups, we
may construct a Rees category and prove that the fundamental group of the
former is the universal group of the latter. In this way, Bass-Serre theory may
be viewed as a special case of the general problem of embedding categories into
groupoids.


title:
The random field Ising model with an asymmetric trimodal probability
  distribution

abstract:
  The Ising model in the presence of a random field is investigated within the
mean field approximation based on Landau expansion. The random field is drawn
from the trimodal probability distribution $P(h_{i})=p \delta(h_{i}-h_{0}) + q
\delta (h_{i}+h_{0}) + r \delta(h_{i})$, where the probabilities $p, q, r$ take
on values within the interval $[0,1]$ consistent with the constraint $p+q+r=1$
(asymmetric distribution), $h_{i}$ is the random field variable and $h_{0}$ the
respective strength. This probability distribution is an extension of the
bimodal one allowing for the existence in the lattice of non magnetic particles
or vacant sites. The current random field Ising system displays second order
phase transitions, which, for some values of $p, q$ and $h_{0}$, are followed
by first order phase transitions, thus confirming the existence of a
tricritical point and in some cases two tricritical points. Also, reentrance
can be seen for appropriate ranges of the aforementioned variables. Using the
variational principle, we determine the equilibrium equation for magnetization,
solve it for both transitions and at the tricritical point in order to
determine the magnetization profile with respect to $h_{0}$.


title:
130 GeV gamma ray line and enhanced Higgs di-photon rate from
  Triplet-Singlet extended MSSM

abstract:
  We propose an economic extension of minimal supersymmetric standard model
with a SU(2) singlet and Y=0 triplet, which can explain (i) the 125 GeV Higgs
boson without fine tuning, (ii) the 130 GeV $\gamma$-ray line seen at
Fermi-LAT, (as well as a second photon line at 114 GeV)(iii) an enhanced Higgs
di-photon decay rate seen by ATLAS, while being consistent with dark matter
relic density and recent XENON 100 exclusion limits on spin-independent direct
detection cross-section. We obtain the required cross-section of
$10^{-27}cm^3s^{-1}$ for the 130 GeV $\gamma$-ray flux through the resonant
annihilation of dark matter via pseudoscalar triplet Higgs of mass $\sim$260
GeV. The dark matter is predominantly bino-higgsino which has large couplings
with photons (through higgsino) and gives correct relic density (through bino).
We get the enhanced Higgs diphoton decay rate, $R_{\gamma \gamma}\simeq 1.24$
dominantly contributed by the light chargino-loops, which can account for the
reported excess seen in the $h\rightarrow \gamma \gamma$ channel by ATLAS.


title: Study of the 4He crystal surface

abstract:
  The evolution of the meniscus of a helium crystal near the (0001) face is
traced during a change in the boundary conditions at the chamber wall in the
temperature range 0.5-0.9 K. The critical behavior of the contact angle is
studied. An anisotropy is detected in the crystal-glass interface energy. New
data on the temperature dependence of the elementary-step energy are obtained.