title:
Intrinsic VHE Gamma-ray spectra of Blazars as a probe for Extragalactic
  Background Light

abstract:
  Very high energy (VHE) $\gamma$-rays above 10$'$s of GeV energy, emitted from
distant blazars, are attenuated by photons from the extragalactic background
light (EBL). Unfortunately, neither the EBL nor the intrinsic blazar spectrum
is accurately known to derive one quantity from the other. In this work we use
a homogeneous one zone model involving synchrotron, synchrotron self Compton
(SSC) and external Compton (EC) emission mechanisms to estimate the intrinsic
VHE spectra of blazars. The model is applied on three VHE blazars, namely
PKS2155-304, RGB J0710+591 and 3C279, for which simultaneous multi-wavelength
data are available from various observations. The predicted values of the
intrinsic VHE fluxes are then compared with the observations by imaging
atmospheric Cherenkov telescopes to determine the optical depth of VHE
$\gamma$-rays. On comparing these optical depth values with those predicted by
four different EBL models, we observe a somewhat pronounced systematic
deviation for PKS2155-304 and 3C279 at higher energies, especially for the EBL
model proposed by Finke et al.(2010). We attribute this deviation to be an
outcome of either the failure of the extrapolation of blazar SED to VHE
energies and/or due to various assumptions buried in the EBL models.


title: Density-based and transport-based core-periphery structures in networks

abstract:
  Networks often possess mesoscale structures, and studying them can yield
insights into both structure and function. It is most common to study community
structure, but numerous other types of mesoscale structures also exist. In this
paper, we examine core-periphery structures based on both density and
transport. In such structures, core network components are well-connected both
among themselves and to peripheral components, which are not well-connected to
anything. We examine core-periphery structures in a wide range of examples of
transportation, social, and financial networks---including road networks in
large urban areas, a rabbit warren, a dolphin social network, a European
interbank network, and a migration network between counties in the United
States. We illustrate that a recently developed transport-based notion of node
coreness is very useful for characterizing transportation networks. We also
generalize this notion to examine core versus peripheral edges, and we show
that the resulting diagnostic is also useful for transportation networks. To
examine the properties of transportation networks further, we develop a family
of generative models of roadlike networks. We illustrate the effect of the
dimensionality of the embedding space on transportation networks, and we
demonstrate that the correlations between different measures of coreness can be
very different for different types of networks.

categories: physics.soc-ph cond-mat.dis-nn cs.SI q-bio.OT


title: Provable Security of Networks

abstract:
  We propose a definition of {\it security} and a definition of {\it
robustness} of networks against the cascading failure models of deliberate
attacks and random errors respectively, and investigate the principles of the
security and robustness of networks. We propose a {\it security model} such
that networks constructed by the model are provably secure against any attacks
of small sizes under the cascading failure models, and simultaneously follow a
power law, and have the small world property with a navigating algorithm of
time complex $O(\log n)$. It is shown that for any network $G$ constructed from
the security model, $G$ satisfies some remarkable topological properties,
including: (i) the {\it small community phenomenon}, that is, $G$ is rich in
communities of the form $X$ of size poly logarithmic in $\log n$ with
conductance bounded by $O(\frac{1}{|X|^{\beta}})$ for some constant $\beta$,
(ii) small diameter property, with diameter $O(\log n)$ allowing a navigation
by a $O(\log n)$ time algorithm to find a path for arbitrarily given two nodes,
and (iii) power law distribution, and satisfies some probabilistic and
combinatorial principles, including the {\it degree priority theorem}, and {\it
infection-inclusion theorem}. By using these principles, we show that a network
$G$ constructed from the security model is secure for any attacks of small
scales under both the uniform threshold and random threshold cascading failure
models. Our security theorems show that networks constructed from the security
model are provably secure against any attacks of small sizes, for which natural
selections of {\it homophyly, randomness} and {\it preferential attachment} are
the underlying mechanisms.


title: Gas clumping in galaxy clusters

abstract:
  The reconstruction of galaxy cluster's gas density profiles is usually
performed by assuming spherical symmetry and averaging the observed X-ray
emission in circular annuli. In the case of a very inhomogeneous and asymmetric
gas distribution, this method has been shown to return biased results in
numerical simulations because of the $n^2$ dependence of the X-ray emissivity.
We propose a method to recover the true density profiles in the presence of
inhomogeneities, based on the derivation of the azimuthal median of the surface
brightness in concentric annuli. We demonstrate the performance of this method
with numerical simulations, and apply it to a sample of 31 galaxy clusters in
the redshift range 0.04-0.2 observed with ROSAT/PSPC. The clumping factors
recovered by comparing the mean and the median are mild and show a slight trend
of increasing bias with radius. For $R<R_{500}$, we measure a clumping factor
$\sqrt{C}<1.1$, which indicates that the thermodynamic properties and
hydrostatic masses measured in this radial range are only mildly affected by
this effect. Comparing our results with three sets of hydrodynamical numerical
simulations, we found that non-radiative simulations significantly overestimate
the level of inhomogeneities in the ICM, while the runs including cooling, star
formation, and AGN feedback reproduce the observed trends closely. Our results
indicate that most of the accretion of X-ray emitting gas is taking place in
the diffuse, large-scale accretion patterns rather than in compact structures.


title: Harnack's inequality and Green functions on locally finite graphs

abstract:
  In this paper we study the gradient estimate for positive solutions of
Schrodinger equations on locally finite graph. Then we derive Harnack's
inequality for positive solutions of the Schrodinger equations. We also set up
some results about Green functions of the Laplacian equation on locally finite
graph. Interesting properties of Schrodinger equation are derived.

categories: math.DG cs.IT math.AP math.CA math.IT math.MG


title: Harnack inequalities for $1$-$d$ stochastic Klein-Gordon type equations

abstract:
  By the coupling method, we establish the Harnack inequalities, derivative
formula and Driver's integration by parts formula for the stochastic
Klein-Gordon type equations in the interval. We provide a detailed discussion
about the nonlinear term. Some applications are given.


title: Cloud computing security using encryption technique

abstract:
  Cloud Computing has been envisioned as the next generation architecture of IT
Enterprise. The Cloud computing concept offers dynamically scalable resources
provisioned as a service over the Internet. Economic benefits are the main
driver for the Cloud, since it promises the reduction of capital expenditure
and operational expenditure. In order for this to become reality, however,
there are still some challenges to be solved. Most important among these are
security and trust issues,since the users data has to be released to the Cloud
and thus leaves the protection sphere of the data owner.In contrast to
traditional solutions, where the IT services are under proper physical,logical
and personnel controls, Cloud Computing moves the application software and
databases to the large data centers, where the management of the data and
services may not be fully trustworthy. This unique attribute, however, poses
many new security challenges which have not been well understood. Security is
to save data from danger and vulnerability. There are so many dangers and
vulnerabilities to be handled. Various security issues and some of their
solution are explained and are concentrating mainly on public cloud security
issues and their solutions. Data should always be encrypted when stored(using
separate symmetric encryption keys)and transmitted. If this is implemented
appropriately, even if another tenant can access the data, all that will appear
is gibberish. So a method is proposed such that we are encrypting the whole
data along with the cryptographic key.


title: Surface bulk differences in a conventional superconductor, ZrB(12)

abstract:
  We studied the electronic structure of a conventional superconductor, ZrB(12)
using high resolution x-photoemission spectroscopy and single crystalline
samples. Experimental results with different bulk sensitivity reveals boron
deficiency and different valence states of Zr at the surface relative to the
bulk. Signature of a satellite features is observed in the Zr core level
spectra corresponding to the bulk of the material suggesting importance of
electron correlation among the conduction electrons in the bulk while the
surface appears to be uncorrelated. These results provide an insight in
fabricating devices based on such superconductors.


title:
Impurity Screening and Surface Acoustic Wave Absorption in a Dipolar
  Exciton Condensate at Finite Temperatures

abstract:
  We describe the behavior of a repulsively interacting Bose-Einstein
condensate of indirect dipolar exciton gas in a double quantum well (QW) system
under external static or dynamic electric fields at finite temperatures.
Electrostatic perturbation is considered to be created by an impurity atom or
shot-range defect of QW fluctuation. The screening of this defect potential by
an exciton condensate is studied. We find asymptotic spatial dependence of the
screened potential and analyse its dependence on the temperature and exciton
concentration. It is shown that the asymptotic of the screened potential has a
steep power law dependence in contrast to the well known results of electron
gas. This peculiarity reflects the bosonic nature of the exciton condensate.
The behavior of exciton condensate under external alternative field created by
a surface acoustic wave (SAW) is examined in detail. We focus our attention on
the dependence of SAW absorption coefficient on temperature and exciton
concentration. We found that at zero temperatures Landau damping does not
contribute to the SAW absorption, but the Belyaev mechanism produces unusual
behavior of SAW absorption coefficient on exciton concentration: if the exciton
concentration exceeds some critical value, the SAW absorption vanishes. At
finite temperatures Landau damping comes into action and results in washing out
the sharp absorption behavior. Such unusual SAW absorption properties can be
used for experimental evidence of the exciton condensation. This method is also
applicable to the experimental testing of both dark and bright exciton
condensates, that is impossible to do with the optical luminescence technique.


title:
Sedimentation of granular columns in the viscous and weakly inertial
  regimes

abstract:
  We investigate the dynamics of granular columns of point particles that
interact via long-range hydrodynamic interactions and fall under the action of
gravity. We investigate the influence of inertia using the Green's function for
the Oseen equation. The initial conditions (density and aspect ratio) are
systematically varied. Our results suggest that universal self-similar laws may
be sufficient to characterize the temporal and structural evolution of the
granular columns. A characteristic time above which an instability is triggered
(which may enable the formation of clusters) is also retrieved and discussed.


title: Tunable and Growing Network Generation Model with Community Structures

abstract:
  Recent years have seen a growing interest in the modeling and simulation of
social networks to understand several social phenomena. Two important classes
of networks, small world and scale free networks have gained a lot of research
interest. Another important characteristic of social networks is the presence
of community structures. Many social processes such as information diffusion
and disease epidemics depend on the presence of community structures making it
an important property for network generation models to be incorporated. In this
paper, we present a tunable and growing network generation model with small
world and scale free properties as well as the presence of community
structures. The major contribution of this model is that the communities thus
created satisfy three important structural properties: connectivity within each
community follows power-law, communities have high clustering coefficient and
hierarchical community structures are present in the networks generated using
the proposed model. Furthermore, the model is highly robust and capable of
producing networks with a number of different topological characteristics
varying clustering coefficient and inter-cluster edges. Our simulation results
show that the model produces small world and scale free networks along with the
presence of communities depicting real world societies and social networks.


title:
Linear Convergence on Positively Homogeneous Functions of a Comparison
  Based Step-Size Adaptive Randomized Search: the (1+1) ES with Generalized
  One-fifth Success Rule

abstract:
  In the context of unconstraint numerical optimization, this paper
investigates the global linear convergence of a simple probabilistic
derivative-free optimization algorithm (DFO). The algorithm samples a candidate
solution from a standard multivariate normal distribution scaled by a step-size
and centered in the current solution. This solution is accepted if it has a
better objective function value than the current one. Crucial to the algorithm
is the adaptation of the step-size that is done in order to maintain a certain
probability of success. The algorithm, already proposed in the 60's, is a
generalization of the well-known Rechenberg's $(1+1)$ Evolution Strategy (ES)
with one-fifth success rule which was also proposed by Devroye under the name
compound random search or by Schumer and Steiglitz under the name step-size
adaptive random search. In addition to be derivative-free, the algorithm is
function-value-free: it exploits the objective function only through
comparisons. It belongs to the class of comparison-based step-size adaptive
randomized search (CB-SARS). For the convergence analysis, we follow the
methodology developed in a companion paper for investigating linear convergence
of CB-SARS: by exploiting invariance properties of the algorithm, we turn the
study of global linear convergence on scaling-invariant functions into the
study of the stability of an underlying normalized Markov chain (MC). We hence
prove global linear convergence by studying the stability (irreducibility,
recurrence, positivity, geometric ergodicity) of the normalized MC associated
to the $(1+1)$-ES. More precisely, we prove that starting from any initial
solution and any step-size, linear convergence with probability one and in
expectation occurs. Our proof holds on unimodal functions that are the
composite of strictly increasing functions by positively homogeneous functions
with degree $\alpha$ (assumed also to be continuously differentiable). This
function class includes composite of norm functions but also non-quasi convex
functions. Because of the composition by a strictly increasing function, it
includes non continuous functions. We find that a sufficient condition for
global linear convergence is the step-size increase on linear functions, a
condition typically satisfied for standard parameter choices. While introduced
more than 40 years ago, we provide here the first proof of global linear
convergence for the $(1+1)$-ES with generalized one-fifth success rule and the
first proof of linear convergence for a CB-SARS on such a class of functions
that includes non-quasi convex and non-continuous functions. Our proof also
holds on functions where linear convergence of some CB-SARS was previously
proven, namely convex-quadratic functions (including the well-know sphere
function).


title: Weak Minkowski Spaces

abstract:
  We define the notion of weak Minkowski metric and prove some basic properties
of such metrics. We also highlight some of the important analogies between
Minkowski geometry and the Funk and Hilbert geometries.


title: Absolute Algebra III - The saturated spectrum

abstract:
  Let B1 denote the set {0,1} with the usual operations except that $1+1=1$, in
other words, the smallest characteristic 1 semifield . We compare two possible
analogues of the notion of prime ideal for B1--algebras. We then consider the
relations between these notions and Deitmar's theory of F1--schemes.


title: Prime and primary ideals in characteristic one

abstract:
  We study zero divisors and minimal prime ideals in semirings of
characteristic one. Thereafter we find a counterexample to the most obvious
version of primary decomposition, but are able to establish a weaker version.
Lastly, we study Evans'condition in this context.


title: On the commuting probability and supersolvability of finite groups

abstract:
  For a finite group $G$, let $d(G)$ denote the probability that a randomly
chosen pair of elements of $G$ commute. We prove that if $d(G)>1/s$ for some
integer $s>1$ and $G$ splits over an abelian normal nontrivial subgroup $N$,
then $G$ has a nontrivial conjugacy class inside $N$ of size at most $s-1$. We
also extend two results of Barry, MacHale, and N\'{\i} Sh\'{e} on the commuting
probability in connection with supersolvability of finite groups. In
particular, we prove that if $d(G)>5/16$ then either $G$ is supersolvable, or
$G$ isoclinic to $A_4$, or $G/\Center(G)$ is isoclinic to $A_4$.


title: Spectral evolution in a Shastry-Sutherland lattice, HoB(4)

abstract:
  We studied the electronic structure of a Shastry-Sutherland lattice system,
HoB4 employing high resolution photoemission spectroscopy and ab initio band
structure calculations. The surface and bulk borons exhibit subtle differences,
and loss of boron compared to the stoichiometric bulk. However, the surface and
bulk conduction bands near Fermi level are found to be similar. Evolution of
the electronic structure with temperature is found to be similar to that
observed in a typical charge-disordered system. A sharp dip is observed at the
Fermi level in the low temperature spectra revealing signature of
antiferromagnetic gap. Asymmetric spectral weight transfer with temperature
manifests particle-hole asymmetry that may be related to the exotic properties
of these systems.


title: An Existential Proof of the Conjecture on Packing Anchored Rectangles

abstract:
  Let $P_{n}$ be a set of $n$ points, including the origin, in the unit square
$U = [0,1]^2$. We consider the problem of constructing $n$ axis-parallel and
mutually disjoint rectangles inside $U$ such that the bottom-left corner of
each rectangle coincides with a point in $P_{n}$ and the total area covered by
the rectangles is maximized \cite{ibmpuzzle}, \cite{Winkler2007},
\cite{Winkler2010a}, \cite{Winkler2010b}. The longstanding conjecture has been
that at least half of $U$ can be covered when such rectangles are properly
placed. In this paper, we give an existential proof of the conjecture.


title: Higgs decays to $\gamma$ and invisible particles in the standard model

abstract:
  Using the Higgs boson mass $m_h=125$ GeV, the radiative Higgs decays
$h\rightarrow\gamma \nu_l\bar\nu_l$ with $\nu_l = \nu_e,\,\nu_\mu$ and
$\nu_\tau$ are analyzed in the standard model. Our calculation shows that the
inclusive width of these processes, i.e., the sum of
$\Gamma(h\to\gamma\nu_l\bar\nu_l)$ for ${\nu_l=\nu_e,\nu_\mu,\nu_\tau}$, is
$1.41$ keV, which is about $15\%$ of $\Gamma(h\to\gamma\gamma)$. Therefore, the
observation of these channels in the future precise experiments may provide us
some useful information on the Higgs physics both in the standard model and in
its possible extensions.


title:
Hard Lefschetz Property for Hamiltonian torus actions on 6-dimensional
  GKM manifolds

abstract:
  In this paper, we study the hard Lefschetz property of a symplectic manifold
which admits a Hamiltonian torus action. More precisely, let $(M,\omega)$ be a
6-dimensional compact symplectic manifold with a Hamiltonian $T^2$-action. We
will show that if the moment map image of $M$ is a GKM-graph and if the graph
is index-increasing, then $(M,\omega)$ satisfies the hard Lefschetz property.


title: Flows on Bidirected Graphs

abstract:
  The study of nowhere-zero flows began with a key observation of Tutte that in
planar graphs, nowhere-zero k-flows are dual to k-colourings (in the form of
k-tensions). Tutte conjectured that every graph without a cut-edge has a
nowhere-zero 5-flow. Seymour proved that every such graph has a nowhere-zero
6-flow.
  For a graph embedded in an orientable surface of higher genus, flows are not
dual to colourings, but to local-tensions. By Seymour's theorem, every graph on
an orientable surface without the obvious obstruction has a nowhere-zero
6-local-tension. Bouchet conjectured that the same should hold true on
non-orientable surfaces. Equivalently, Bouchet conjectured that every
bidirected graph with a nowhere-zero $\mathbb{Z}$-flow has a nowhere-zero
6-flow. Our main result establishes that every such graph has a nowhere-zero
12-flow.


title: Explicit round fold maps on some fundamental manifolds

abstract:
  Stable fold maps are fundamental tools in a generalization of the theory of
Morse functions on smooth manifolds and its application to studies of
topological properties of smooth manifolds. Round fold maps were introduced as
stable fold maps with singular value sets, defined as the set consisting of all
the singular values, of concentric spheres by the author in 2013; for example,
some special generic maps on spheres are regarded as round fold maps whose
singular value sets are connected. Algebraic invariants such as homology and
homotopy groups of manifolds admitting round fold maps and more precisely, the
homeomorphism and diffeomorphism types of manifolds admitting such maps having
appropriate differential topological structures were studied. Moreover,
explicit round fold maps into the Eucidean space of dimension larger than $1$
are constructed on some fundamental manifolds such as manifolds having the
structures of bundles over the standard sphere of dimension equal to the
Euclidean space whose fibers are closed smooth manifolds and manifolds of
dimension not smaller than twice the dimension of the Euclidean space
represented as the connected sum of manifolds having the structures of bundles
over the standard sphere of dimension equal to the Euclidean space whose fibers
are diffeomorphic to standard spheres. In this paper, we construct new explicit
fold maps on some fundamental manifolds including the manifolds before by using
extended methods of ones used in the constructions before.


title: All Linear-Time Congruences for Familiar Operators

abstract:
  The detailed behaviour of a system is often represented as a labelled
transition system (LTS) and the abstract behaviour as a stuttering-insensitive
semantic congruence. Numerous congruences have been presented in the
literature. On the other hand, there have not been many results proving the
absence of more congruences. This publication fully analyses the linear-time
(in a well-defined sense) region with respect to action prefix, hiding,
relational renaming, and parallel composition. It contains 40 congruences. They
are built from the alphabet, two kinds of traces, two kinds of divergence
traces, five kinds of failures, and four kinds of infinite traces. In the case
of finite LTSs, infinite traces lose their role and the number of congruences
drops to 20. The publication concentrates on the hardest and most novel part of
the result, that is, proving the absence of more congruences.


title:
Enhanced resonant force between two entangled identical atoms in a
  photonic crystal

abstract:
  We consider the resonant interaction energy and force between two identical
atoms, one in an excited state and the other in the ground state, placed inside
a photonic crystal. The atoms, having the same orientation of their dipole
moment, are supposed prepared in their symmetrical state and interact with the
quantum electromagnetic field. We consider two specific models of photonic
crystals: a one-dimensional model and an isotropic model. We show that in both
cases the resonant interatomic force can be strongly enhanced by the presence
of the photonic crystal, as a consequence of the modified dispersion relation
and density of states, in particular if the transition frequency of the atoms
is close to the edge of a photonic gap. Differences between the two models
considered of photonic crystal are discussed in detail, as well as comparison
with the analogous system of two impurity atoms in a quantum semiconductor
wire. A numerical estimate of the effect in a realistic situation is also
discussed.


title: Photonic processes in Born-Infeld theory

abstract:
  We study the processes of photon-photon scattering and photon splitting in a
magnetic field in Born-Infeld theory. In both cases we combine the terms from
the tree-level Born-Infeld Lagrangian with the usual one-loop QED
contributions, where those are approximated by the Euler-Heisenberg Lagrangian,
including also the interference terms. For photon-photon scattering we obtain
the total cross section in the low-energy approximation. For photon splitting
we compute the total absorption coefficient in the hexagon (weak field)
approximation, and also show that, due to the non-birefringence property of
Born-Infeld theory, the selection rules found by Adler for the QED case
continue to hold in this more general setting. We discuss the bounds on the
free parameter of Born-Infeld theory that may be obtained from this type of
processes.


title:
Verification by stochastic Perron's method in stochastic exit time
  control problems

abstract:
  We apply the Stochastic Perron method, created by Bayraktar and S\^irbu, to a
stochastic exit time control problem. Our main assumption is the validity of
the Strong Comparison Result for the related Hamilton-Jacobi-Bellman (HJB)
equation. Without relying on Bellman's optimality principle we prove that
inside the domain the value function is continuous and coincides with a
viscosity solution of the Dirichlet boundary value problem for the HJB
equation.


title:
Wetting Boundary Conditions in Phase-Field-Based Simulation of Binary
  Fluids: Some Comparative Studies and New Development

abstract:
  We studied several wetting boundary conditions (WBCs) in the simulation of
binary fluids based on phase-field theory. Five WBCs, three belonging to the
surface energy (SE) formulation using the linear, cubic and sine functions
(denoted as LinSE, CubSE and SinSE), the fourth using a geometric formulation
(Geom), and the fifth using a characteristic interpolation (CI), were compared
with each other through the study of several problems: (1) the static contact
angle of a drop; (2) a Poiseuille flow-driven liquid column; (3) a wettability
gradient (WG)-driven liquid column; (4) drop dewetting. It was found that while
all WBCs can predict the static contact angle fairly accurately, they may
affect the simulation outcomes of dynamic problems differently, depending on
the driving mechanism. For the flow-driven problem, to use different WBCs had
almost no effect on the flow characteristics over a large scale. But for other
capillarity-driven problems, the WBC had some noticeable effects. For the
WG-driven liquid column, Geom gave the most consistent prediction between the
drop velocity and dynamic contact angles, and LinSE delivered the poorest
prediction in this aspect. Except for Geom, the dynamic contact angle differed
from the prescribed (static) one when other WBCs were used. For drop dewetting,
Geom led to the most violent drop motion whereas CubSE caused the weakest
motion; the initial contact line velocity was also found to be dependent on the
WBC. For several problems, CubSE and SinSE gave almost the same results, and
those by Geom and CI were close as well, possibly due to similar consideration
in their design. Besides various comparisons, a new implementation that may be
used for all WBCs was proposed to mimic the wall energy relaxation and control
the degree of slip. This new procedure made it possible to allow the
simulations to match experimental measurements well.


title: Nilpotent and Abelian Hall Subgroups in Finite Groups

abstract:
  We give a characterization of the finite groups having nilpotent or abelian
Hall $\pi$-subgroups which can easily be verified from the character table.


title: Combinatorics of Link Diagrams and Volume

abstract:
  We show that the volumes of certain hyperbolic A-adequate links can be
bounded (above and) below in terms of two diagrammatic quantities: the twist
number and the number of certain alternating tangles in an A-adequate diagram.
We then restrict our attention to plat closures of certain braids, a rich
family of links whose volumes can be bounded in terms of the twist number
alone. Furthermore, in the absence of special tangles, our volume bounds can be
expressed in terms of a single stable coefficient of the colored Jones
polynomial. Consequently, we are able to provide a new collection of links that
satisfy a Coarse Volume Conjecture.


title: "Cracking-the-whip" effect stretches driven polymers

abstract:
  Cracking the whip accelerates the tail of a chain to hit the air loudly and
clearly. We proved that the similar acceleration effect causes coil deformation
of driven chain-like polymers. We first preformed Monte Carlo simulations of a
single driven polymer coil to demonstrate its deformation in company with
faster or slower deviations of velocities. We then performed parallel Brownian
Dynamics simulations to demonstrate that the coil deformation can be caused by
the so-called "cracking-the-whip" effect due to non-synchronous biased Brownian
motions of monomers inherited in Monte Carlo simulations. Since such
non-synchronous motions represent random perturbations in the environmentally
dependent potential energy landscape or mobility, reflecting heterogeneous
dynamics of polymers in the liquid phase, our observations bring new insights
into the non-linear dynamics of driven chain-like polymers.


title:
Holographic Approach to Nonequilibrium Dynamics of Moving Mirrors
  Coupled to Quantum Critical Theories

abstract:
  We employ the holographic method to study fluctuations and dissipation of an
$n$-dimensional moving mirror coupled to quantum critical theories in $d$
spacetime dimensions. The bulk counterpart of the mirror with perfect
reflection is a D$(n+1)$ brane in the Lifshitz geometry of $d+1$ dimensions.
The motion of the mirror can be realized from the dynamics of the brane at the
boundary of the bulk. The excited modes of the brane in the bulk render the
mirror undergoing Brownian motion. For small displacement of the mirror, we
derive the analytical results of the correlation functions and response
functions. The dynamics of the mirror due to small fluctuations around the
brane vacuum state in the bulk is found supraohmic so that after initial
growth, the velocity fluctuations approach a saturated value at late time with
a power-law behavior. On the contrary, in the Lifshitz black hole background,
the mirror in thermal fluctuations shows that its relaxation dynamics becomes
ohmic, and the saturation of velocity fluctuations is reached exponentially in
time. Finally a comparison is made with the result of a moving mirror driven by
free fields.


title: Cycling Dynamo in a Young Sun: Grand Minima and Equatorward Propagation

abstract:
  We assess the global-scale dynamo action achieved in a simulation of a
sun-like star rotating at three times the solar rate. The 3-D MHD Anelastic
Spherical Harmonic code, using slope-limited diffusion, is employed to capture
convection and dynamo processes in such a young sun. The simulation is carried
out in a spherical shell that encompasses 3.8 density scale heights of the
solar convection zone. We find that dynamo action with a high degree of time
variation occurs, with many periodic polarity reversals every 6.2 years. The
magnetic energy also rises and falls with a regular period, with two magnetic
energy cycles required to complete a polarity cycle. These magnetic energy
cycles arise from a Lorentz-force feedback on the differential rotation,
whereas the polarity reversals are present due to the spatial separation of the
equatorial and polar dynamos. Moreover, an equatorial migration of toroidal
field is found, which is linked to the changing differential rotation and to a
near-surface shear layer. This simulation also enters a grand minimum lasting
roughly 20 years, after which the dynamo recovers its regular polarity cycles.


title:
An efficient distributed learning algorithm based on effective local
  functional approximations

abstract:
  Scalable machine learning over big data is an important problem that is
receiving a lot of attention in recent years. On popular distributed
environments such as Hadoop running on a cluster of commodity machines,
communication costs are substantial and algorithms need to be designed suitably
considering those costs. In this paper we give a novel approach to the
distributed training of linear classifiers (involving smooth losses and L2
regularization) that is designed to reduce the total communication costs. At
each iteration, the nodes minimize locally formed approximate objective
functions; then the resulting minimizers are combined to form a descent
direction to move. Our approach gives a lot of freedom in the formation of the
approximate objective function as well as in the choice of methods to solve
them. The method is shown to have $O(log(1/\epsilon))$ time convergence. The
method can be viewed as an iterative parameter mixing method. A special
instantiation yields a parallel stochastic gradient descent method with strong
convergence. When communication times between nodes are large, our method is
much faster than the Terascale method (Agarwal et al., 2011), which is a state
of the art distributed solver based on the statistical query model (Chuet al.,
2006) that computes function and gradient values in a distributed fashion. We
also evaluate against other recent distributed methods and demonstrate superior
performance of our method.


title: Valence double parton distributions of the nucleon in a simple model

abstract:
  Valence double parton distribution functions of the nucleon are evaluated in
the framework of a simple model, where the conservation of the longitudinal
momentum is taken into account. The leading-order DGLAP QCD evolution from the
low quark-model scale to higher renormalization scales is carried out via the
Mellin moments of the distributions. Results of the valence quark correlation
function show that in general the double distributions cannot be approximated
as a product of the single-particle distributions.


title: SMaSH: A Benchmarking Toolkit for Human Genome Variant Calling

abstract:
  Motivation: Computational methods are essential to extract actionable
information from raw sequencing data, and to thus fulfill the promise of
next-generation sequencing technology. Unfortunately, computational tools
developed to call variants from human sequencing data disagree on many of their
predictions, and current methods to evaluate accuracy and computational
performance are ad-hoc and incomplete. Agreement on benchmarking variant
calling methods would stimulate development of genomic processing tools and
facilitate communication among researchers.
  Results: We propose SMaSH, a benchmarking methodology for evaluating human
genome variant calling algorithms. We generate synthetic datasets, organize and
interpret a wide range of existing benchmarking data for real genomes, and
propose a set of accuracy and computational performance metrics for evaluating
variant calling methods on this benchmarking data. Moreover, we illustrate the
utility of SMaSH to evaluate the performance of some leading single nucleotide
polymorphism (SNP), indel, and structural variant calling algorithms.
  Availability: We provide free and open access online to the SMaSH toolkit,
along with detailed documentation, at smash.cs.berkeley.edu.


title:
Multiple positive solutions for a nonlinear three-point integral
  boundary-value problem

abstract:
  We investigate the existence of positive solutions to the nonlinear
second-order three-point integral boundary value problem \begin{equation*}
\label{eq-1} \begin{gathered} {u^{\prime \prime}}(t)+f(t, u(t))=0,\ 0<t<T, \\
u(0)={\beta}u(\eta),\ u(T)={\alpha}\int_{0}^{\eta}u(s)ds, \end{gathered}
\end{equation*} where $0<{\eta}<T$, $0<{\alpha}< \frac{2T}{{\eta}^{2}}$,
$0<{\beta}<\frac{2T-\alpha\eta^{2}}{\alpha\eta^{2}-2\eta+2T}$ are given
constants. We establish the existence of at least three positive solutions by
using the Leggett-Williams fixed-point theorem.


title:
Recurrence statistics for the space of Interval Exchange maps and the
  Teichm\"uller flow on the space of translation surfaces

abstract:
  In this note we show that the transfer operator of a Rauzy-Veech-Zorich
renormalization map acting on a space of quasi-H\"older functions is
quasicompact and derive certain statistical recurrence properties for this map
and its associated Teichm\"uller flow. We establish Borel-Cantelli lemmas,
Extreme Value statistics and return time statistics for the map and flow.
Previous results have established quasicompactness in H\"older or analytic
function spaces, for example the work of M. Pollicott and T. Morita. The
quasi-H\"older function space is particularly useful for investigating return
time statistics. In particular we establish the shrinking target property for
nested balls in the setting of Teichm\"uller flow. Our point of view, approach
and terminology derives from the work of M. Pollicott augmented by that of M.
Viana.


title: Flux tubes and coherence length in the SU(3) vacuum

abstract:
  An estimate of the London penetration and coherence lengths in the vacuum of
the SU(3) pure gauge theory is given downstream an analysis of the transverse
profile of the chromoelectric flux tubes. Within ordinary superconductivity, a
simple variational model for the magnitude of the normalized order parameter of
an isolated vortex produces an analytic expression for magnetic field and
supercurrent density. In the picture of SU(3) vacuum as dual superconductor,
this expression provides us with the function that fits the chromoelectric
field data. The smearing procedure is used in order to reduce noise.


title: On the concavity of the arithmetic volumes

abstract:
  In this note, we study the differentiability of the arithmetic volumes along
arithmetic R-divisors, and give some equality conditions for the
Brunn-Minkowski inequality for arithmetic volumes over the cone of nef and big
arithmetic R-divisors.


title: Polynomial spaces reproduced by elliptic scaling functions

abstract:
  The Strang-Fix conditions are necessary and sufficient to reproduce spaces of
algebraic polynomials up to some degree by integer shifts of compactly
supported functions. W. Dahmen and Ch. Micchelli (Linear Algebra Appl.
52/3:217-234, 1983) introduced a generalization of the Strang-Fix conditions to
affinely invariant subspaces of higher degree polynomials. C. de Boor (Constr.
Approx. 3:199-208, 1987) raised a question on the necessity of scale-invariance
of polynomial space for an arbitrary function; and he omitted the
scale-invariance restriction on the space. In the paper, we present a matrix
approach to determine (not necessarily scale-invariant) polynomial space
contained in the span of integer shifts of a compactly supported function.
Also, in the paper, we consider scaling functions that we call the elliptic
scaling functions (Int. J. Wavelets Multiresolut. Inf. Process. To appear);
and, using the matrix approach, we prove that the elliptic scaling functions
satisfy the generalized Strang-Fix conditions and reproduce only affinely
invariant polynomial spaces. Namely we prove that any algebraic polynomial
contained in the span of integer shifts of a compactly supported elliptic
scaling function belongs to the null-space of a homogeneous elliptic
differential operator. However, in the paper, we present nonstationary elliptic
scaling functions such that the scaling functions reproduce not scale-invariant
(only shift-invariant) polynomial spaces.


title:
Dynamic connectivity algorithms for Monte Carlo simulations of the
  random-cluster model

abstract:
  We review Sweeny's algorithm for Monte Carlo simulations of the random
cluster model. Straightforward implementations suffer from the problem of
computational critical slowing down, where the computational effort per edge
operation scales with a power of the system size. By using a tailored dynamic
connectivity algorithm we are able to perform all operations with a
poly-logarithmic computational effort. This approach is shown to be efficient
in keeping online connectivity information and is of use for a number of
applications also beyond cluster-update simulations, for instance in monitoring
droplet shape transitions. As the handling of the relevant data structures is
non-trivial, we provide a Python module with a full implementation for future
reference.


title:
Origin of two-dimensional electron gases at oxide interfaces: insights
  from theory

abstract:
  The response of oxide thin films to polar discontinuities at interfaces and
surfaces has generated an enormous activity due to the variety of interesting
effects it gives rise to. A case in point is the discovery of the electron gas
at the interface between LaAlO3 and SrTiO3, which has since been shown to be
quasi-two-dimensional, switchable, magnetic and/or superconducting. Despite
these findings, the origin of the two-dimensional electron gas is highly
debated and several possible mechanisms remain. Here we review the main
proposed mechanisms and attempt to model expected effects in a quantitative way
with the ambition of better constraining what effects can/cannot explain the
observed phenomenology. We do it in the framework of a phenomenological model
for understanding electronic and/or redox screening of the chemical charge in
oxide heterostructures. We also discuss the effect of intermixing, both
conserving and non-conserving the total stoichiometry.


title: Multilabel Classification through Random Graph Ensembles

abstract:
  We present new methods for multilabel classification, relying on ensemble
learning on a collection of random output graphs imposed on the multilabel and
a kernel-based structured output learner as the base classifier. For ensemble
learning, differences among the output graphs provide the required base
classifier diversity and lead to improved performance in the increasing size of
the ensemble. We study different methods of forming the ensemble prediction,
including majority voting and two methods that perform inferences over the
graph structures before or after combining the base models into the ensemble.
We compare the methods against the state-of-the-art machine learning approaches
on a set of heterogeneous multilabel benchmark problems, including multilabel
AdaBoost, convex multitask feature learning, as well as single target learning
approaches represented by Bagging and SVM. In our experiments, the random graph
ensembles are very competitive and robust, ranking first or second on most of
the datasets. Overall, our results show that random graph ensembles are viable
alternatives to flat multilabel and multitask learners.


title:
An analysis of HCN observations of the Circumnuclear Disk at the
  galactic centre

abstract:
  The Circumnuclear Disk (CND) is a torus of dust and molecular gas rotating
about the galactic centre and extending from approximately 1.6pc to 7pc from
the central massive black hole, SgrA*. Large Velocity Gradient modelling of the
intensities of the HCN 1-0, 3-2 and 4-3 transitions is used to infer hydrogen
density and HCN optical depth. From HCN observations we find the molecular
hydrogen density ranges from 0.1 to 2 $\times$ 10$^{6}$ cm$^{-3}$, about an
order of magnitude less than inferred previously. The 1-0 line is weakly
inverted with line-centre optical depth approx $-$0.1, in stark contrast to
earlier estimates of 4. The estimated mass of the ring is approximately 3 $-$ 4
$\times$ 10$^{5}$M$_{\odot}$ consistent with estimates based on thermal dust
emission. The tidal shear in the disk implies that star formation is not
expected to occur without some significant triggering event.


title: Size dependence of the largest distance between random points

abstract:
  A set of $N$ points is chosen randomly in a $D$-dimensional volume $V=a^D$,
with periodic boundary conditions. For each point $i$, its distance $d_i$ is
found to its nearest neighbour. Then, the maximal value is found,
$d_{max}=max(d_i, i=1,...,N)$. Our numerical calculations indicate, that when
the density $N/V$=const, $d_{max}$ scales with the linear system size as
$d^2_{max}\propto a^\phi$, with $\phi=0.24\pm0.04$ for $D=1,2,3,4$.


title: Multiagent's model of stock market with p-adic description of prices

abstract:
  A new multiagent model of the stock market is formulated that contains four
states in which the agents may be located. Next, the model is reformulated in
the language of the functional integral containing fluctuations of prices and
quantities of cash flows. It is shown that in the functional integral of that
type description of the prices is given not by the real numbers as is made in
many papers but the p-adic numbers. It is shown in the following simple
examples extracted from the proposed theory that the p-adic description of
prices gives good description of fractal behavior of the trends. The formula is
given for the p-adic mapping of prices. Using this formula we obtain the main
p-adic patterns which are the same as the patterns of Elliott wave theory, this
fact allows us to give a rigorous mathematical proof of this theory. Our model
is the only model that gives a strict point like description of the fractal
behavior of prices. The developed approach opens the possibility to give the
formulation of p-adic technical analysis of the stock market.


title: Molecular Jet of IRAS 04166+2706

abstract:
  The molecular outflow from IRAS 04166+2706 was mapped with the Submillimeter
Array (SMA) at 350 GHz continuum and CO J = 3$-$2 at an angular resolution of
~1 arcsec. The field of view covers the central arc-minute, which contains the
inner four pairs of knots of the molecular jet. On the channel map, conical
structures are clearly present in the low velocity range (|V$-$V$_0$|$<$10 km
s$^{-1}$), and the highly collimated knots appear in the Extremely High
Velocity range (EHV, 50$>$|V$-$V$_0$|$>$30 km s$^{-1}$). The higher angular
resolution of ~1 arcsec reveals the first blue-shifted knot (B1) that was
missing in previous PdBI observation of Sant\'iago-Garc\'ia et al. (2009) at an
offset of ~6 arcsec to the North-East of the central source. This
identification completes the symmetric sequence of knots in both the blue- and
red-shifted lobes of the outflow. The innermost knots R1 and B1 have the
highest velocities within the sequence. Although the general features appear to
be similar to previous CO J = 2$-$1 images in Sant\'iago-Garc\'ia et al.
(2009), the emission in CO J = 3$-$2 almost always peaks further away from the
central source than that of CO J = 2$-$1 in the red-shifted lobe of the channel
maps. This gives rise to a gradient in the line-ratio map of CO J = 3$-$2/J =
2$-$1 from head to tail within a knot. A large velocity gradient (LVG) analysis
suggests that the differences may reflect a higher gas kinetic temperature at
the head. We also explore possible constraints imposed by the non-detection of
SiO J = 8$-$7.


title:
Impact of nitrogen seeding on confinement and power load control of a
  high-triangularity JET ELMy H-mode plasma with a metal wall

abstract:
  This paper reports the impact on confinement and power load of the high-shape
2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing
components to an all metal wall. In preparation to this change, systematic
studies of power load reduction and impact on confinement as a result of
fuelling in combination with nitrogen seeding were carried out in JET-C and are
compared to their counterpart in JET with a metallic wall. An unexpected and
significant change is reported on the decrease of the pedestal confinement but
is partially recovered with the injection of nitrogen.


title:
Copolymer template control of gold nanoparticle synthesis via thermal
  annealing

abstract:
  We present here an original process combining top-down and bottom-up
approaches by annealing a thin gold film evaporated onto a hole template made
by etching a PS-PMMA copolymer film. Such process allows a better control of
the gold nanoparticle size distribution which provides a sharper localized
surface plasmon resonance. This makes such route appealing for sensing
applications since the figure of merit of the Au nanoparticles obtained after
thermal evaporation is more than doubled. Such process could besides allow
tuning the localized surface plasmon resonance by using copolymer with various
molecular weights and thus be attractive for surface enhanced raman
spectroscopy.


title: Extensive search for bias in SNIa data

abstract:
  The use of advanced statistical analysis tools is crucial in order to improve
cosmological parameter estimates via removal of systematic errors and
identification of previously unaccounted for cosmological signals. Here we
demonstrate the application of a new fully-Bayesian method, the internal
robustness formalism, to scan for systematics and new signals in the recent
supernova Ia Union compilations. Our analysis is tailored to maximize chances
of detecting the anomalous subsets by means of a variety of sorting algorithms.
We analyse supernova Ia distance moduli for effects depending on angular
separation, redshift, surveys and hemispherical directions. The data have
proven to be robust within 2 sigma, giving an independent confirmation of
successful removal of systematics-contaminated supernovae. Hints of new
cosmology, as for example the anisotropies reported by Planck, do not seem to
be reflected in the supernova Ia data.


title:
Spatial Imaging of Land\'{e} g Factor through Extended Kondo Effect in a
  Single Magnetic Molecule

abstract:
  A methodology of atomically resolved Land\'{e} g factor mapping of a single
molecule is reported. Mn(II)-phthalocyanine (MnPc) molecules on Au(111) surface
can be dehydrogenated via atomic manipulation with manifestation of tailored
extended Kondo effect, which can allow atomically resolved imaging of the
Land\'{e} g factor inside a molecule for the first time. By employing
dehydrogenated MnPc molecules with removal of six H atoms (-6H-MnPc) as an
example, Land\'{e} g factor of atomic constituents of the molecule can be
obtained, therefore offering a unique g factor mapping of single molecule. Our
results open up a new avenue to access local spin texture of a single molecule.


title:
Self-consistent simulation of plasma scenarios for ITER using a
  combination of 1.5D transport codes and free-boundary equilibrium codes

abstract:
  Self-consistent transport simulation of ITER scenarios is a very important
tool for the exploration of the operational space and for scenario
optimisation. It also provides an assessment of the compatibility of developed
scenarios (which include fast transient events) with machine constraints, in
particular with the poloidal field (PF) coil system, heating and current drive
(H&CD), fuelling and particle and energy exhaust systems. This paper discusses
results of predictive modelling of all reference ITER scenarios and variants
using two suite of linked transport and equilibrium codes. The first suite
consisting of the 1.5D core/2D SOL code JINTRAC [1] and the free boundary
equilibrium evolution code CREATE-NL [2,3], was mainly used to simulate the
inductive D-T reference Scenario-2 with fusion gain Q=10 and its variants in H,
D and He (including ITER scenarios with reduced current and toroidal field).
The second suite of codes was used mainly for the modelling of hybrid and
steady state ITER scenarios. It combines the 1.5D core transport code CRONOS
[4] and the free boundary equilibrium evolution code DINA-CH [5].


title:
Assessment of energetic neutral He atom intensities expected from the
  IBEX Ribbon

abstract:
  Full sky maps of energetic neutral atoms (ENA) obtained with the Interstellar
Boundary Explorer revealed a bright, arc-like Ribbon. We compare possible,
though as yet undetected, He ENA emission in two models of the Ribbon origin.
The models were originally developed for hydrogen ENA. In the first one, ENA
are produced outside the heliopause from the ionized neutral solar wind in the
direction where the local interstellar magnetic field is perpendicular to the
line-of-sight. The second model proposes production at the contact layer
between the Local Interstellar Cloud (LIC) and the Local Bubble (LB). The
models are redesigned to helium using relevant interactions between atoms and
ions. Resulting intensities are compared with possible emission of helium ENA
from the heliosheath. In the first model, the expected intensity is ~ 0.014
(cm^2 s sr keV)^-1, i.e., of the order of the He emission from the heliosheath,
whereas in the second, the LIC/LB contact layer model, the intensity is ~ (2-7)
(cm^2 s sr keV)^-1, i.e., a few hundred times larger. If the IBEX Ribbon needs
a source population of He ENA leaving the heliosphere, it should not be visible
in He ENA fluxes mainly because of the insufficient supply of the parent He ENA
originating from the neutralized solar wind {\alpha}-particles. We conclude
that full-sky measurements of He ENA could give promising prospect for probing
the Local Interstellar Medium at the distance of a few thousand AU and create
possibility of distinction between above mentioned models of Ribbon origin.


title:
The electronic structure of a graphene quantum dot:
  Electric-field-induced evolution in two subspaces

abstract:
  The tight-binding method is employed to investigate the effects of three
typical in-plane electric fields on the electronic structure of a triangular
zigzag graphene quantum dot. The calculation shows that the single-electron
eigenstates evolute independently in two subspaces no matter how the electric
fields change. The electric field with fixed-geometry gates chooses several
scattered parts of the zero-energy eigenspace as the new zero-energy
eigenstates, regardless of the field strength. Moreover, the new zero-energy
eigenstates remain unchanged and the associated levels are linear as the field
strength. In contrast, the new nonzero-energy eigenstates mix mutually and the
associated levels are nonlinear as the field strength. By comparing the effects
of three electric fields, we demonstrate that the degeneracy of the zero-energy
eigenstates accounts for the linearity of the associated levels.


title:
A class of symmetric $q$-orthogonal polynomials with four free
  parameters

abstract:
  By using a generalization of Sturm-Liouville problems in $q$-difference
spaces, a class of symmetric $q$-orthogonal polynomials with four free
parameters is introduced. The standard properties of these polynomials, such as
a second order $q$-difference equation, the explicit form of the polynomials in
terms of basic hypergeometric series, a three term recurrence relation and a
general orthogonality relation are presented. Some particular examples are then
studied in detail.


title: Edge-colorings and circular flow numbers on regular graphs

abstract:
  The paper characterizes $(2t+1)$-regular graphs with circular flow number $2
+ \frac{2}{2t-1}$. For $t=1$ this is Tutte's characterization of cubic graphs
with flow number 4. The class of cubic graphs is the only class of odd regular
graphs where a flow number separates the class 1 graphs from the class 2
graphs. We finally state some conjectures and relate them to existing
flow-conjectures.


title: Some Motzkin-Straus type results for non-uniform hypergraphs

abstract:
  A remarkable connection between the order of a maximum clique and the
Lagrangian of a graph was established by Motzkin and Straus in 1965. This
connection and its extensions were applied in Tur\'{a}n problems of graphs and
uniform hypergraphs. Very recently, the study of Tur\'{a}n densities of
non-uniform hypergraphs has been motivated by extremal poset problems. In this
paper, we give some Motzkin-Straus type results for non-uniform hypergraphs.


title: Inconsistency of the Wolf sunspot number series around 1848

abstract:
  Aims. Sunspot number is a benchmark series in many studies, but may still
contain inhomogeneities and inconsistencies. In particular, an essential
discrepancy exists between the two main sunspot number series, Wolf (WSN) and
group (GSN) sunspot numbers, before 1848. The source of this discrepancy has so
far remained unresolved. However, the recently digitized series of solar
observations in 1825-1867 by Samuel Heinrich Schwabe, who was the primary
observer of the WSN before 1848, makes such an assessment possible. Methods. We
construct sunspot series, similar to WSN and GSN, but using only Schwabe's
data. These series, called WSN-S and GSN-S, respectively, were compared with
the original WSN and GSN series for the period 1835-1867 to look for possible
inhomogeneities. Results. We show that: (1) The GSN series is homogeneous and
consistent with the Schwabe data throughout the entire studied period; (2) The
WSN series decreases by roughly ~20% around 1848 caused by the change of the
primary observer from Schwabe to Wolf and an inappropriate individual
correction factor used for Schwabe in the WSN; (3) This implies a major
inhomogeneity in the WSN, which needs to be corrected by reducing its values by
20% before 1848; (4) The corrected WSN series is in good agreement with the GSN
series. This study supports the earlier conclusions that the GSN series is more
consistent and homogeneous in the earlier part than the WSN series.


title: Ion impact induced Interatomic Coulombic Decay in neon and argon dimers

abstract:
  We investigate the contribution of Interatomic Coulombic Decay induced by ion
impact in neon and argon dimers (Ne$_2$ and Ar$_2$) to the production of low
energy electrons. Our experiments cover a broad range of perturbation strengths
and reaction channels. We use 11.37 MeV/u S$^{14+}$, 0.125 MeV/u He$^{1+}$,
0.1625 MeV/u He$^{1+}$ and 0.150 MeV/u He$^{2+}$ as projectiles and study
ionization, single and double electron transfer to the projectile as well as
projectile electron loss processes. The application of a COLTRIMS reaction
microscope enables us to retrieve the three-dimensional momentum vectors of the
ion pairs of the fragmenting dimer into Ne$^{q+}$/Ne$^{1+}$ and
Ar$^{q+}$/Ar$^{1+}$ (q = 1, 2, 3) in coincidence with at least one emitted
electron.


title: Energetic particle instabilities in fusion plasmas

abstract:
  Remarkable progress has been made in diagnosing energetic particle
instabilities on present-day machines and in establishing a theoretical
framework for describing them. This overview describes the much improved
diagnostics of Alfven instabilities and modelling tools developed world-wide,
and discusses progress in interpreting the observed phenomena. A multi-machine
comparison is presented giving information on the performance of both
diagnostics and modelling tools for different plasma conditions outlining
expectations for ITER based on our present knowledge.


title: A variant of K-theory and topological T-duality for Real circle bundles

abstract:
  For a space with involutive action, there is a variant of K-theory. Motivated
by T-duality in type II orbifold string theory, we establish that a twisted
version of the variant enjoys a topological T-duality for Real circle bundles,
i.e. circle bundles with real structure.


title: Multigrade efficient congruencing and Vinogradov's mean value theorem

abstract:
  We develop a multigrade enhancement of the efficient congruencing method to
estimate Vinogradov's integral of degree $k$ for moments of order $2s$, thereby
obtaining near-optimal estimates for $\tfrac{5}{8}k^2<s\le k^2-k+1$. There are
numerous applications. In particular, when $k$ is large, the anticipated
asymptotic formula in Waring's problem is established for sums of $s$ $k$th
powers of natural numbers whenever $s>1.543k^2$. The asymptotic formula is also
established for sums of $28$ fifth powers.


title: Jet tomography of AA-collisions at RHIC and LHC energies

abstract:
  We present our recent results on jet tomography of AA-collisions at RHIC and
LHC. We focus on flavor dependence of the nuclear modification factor. The
computations are performed accounting for radiative and collisional parton
energy loss with running coupling constant.


title:
Buffering and Trapping Ultrashort Optical Pulses in Concatenated Bragg
  Gratings

abstract:
  Strong retardation of ultrashort optical pulses, including their deceleration
and stoppage in the form of Bragg solitons in a cascaded Bragg-grating (BG)
structure, is proposed. The manipulations of the pulses are carried out, using
nonlinear effects, in a chirped BG segment which is linked, via a defect, to a
uniform grating. The storage of the ultrashort pulses is shown to be very
robust with respect to variations of the input field intensity, suggesting the
feasibility of storing ultrafast optical pulses in such a structure. Physical
estimates are produced for the BGs written in silicon.


title: New magnetic real time shape control for MAST

abstract:
  The MAST (Mega Ampere Spherical Tokamak) real time plasma position controller
is based on an optical linear camera placed on the mid plane of the vessel.
This solution has the advantage of being a direct observation of the D
[alpha]emissions coming from the interaction between the boundary of the plasma
and neutral gas, but, on the other hand, it restricts the control to the outer
radius of the plasma only. A complete chain of tools has been set up to
implement, test and simulate a new real time magnetic plasma shape controller
based on the rtEFIT code. The complete working path consists of three elements:
a linear static relationship between control parameters and current demands, a
linear state space model needed to represent the plasma dynamic response in
closed loop simulations, and the possibility to run simulations inside the
Plasma Control System (PCS). The linear relationship has been calculated using
the FIESTA code, which is developed using Matlab at CCFE. The linear state
space model was generated using the CREATE-L code developed by the CREATE
Consortium. It has already been successfully used to model JET, FTU and TCV
tokamaks. Using this working path many simulations have been carried out
allowing fine tuning of the control gains before the real experiment. The
simulation testing includes the plasma shape control law as implemented in PCS
itself, so intensive debugging has been possible prior to operation. Successful
control using rtEFIT was established in the second dedicated experiment during
the MAST 2011-12 campaign. This work is a stepping stone towards divertor
control which is ultimately intended for application to the super-X divertor in
the MAST Upgrade experiment.


title: ANTARES Deep Sea Neutrino Telescope Results

abstract:
  The ANTARES experiment is currently the largest underwater neutrino telescope
in the Northern Hemisphere. It is taking high quality data since 2007. Its main
scientific goal is to search for high energy neutrinos that are expected from
the acceleration of cosmic rays from astrophysical sources. This contribution
reviews the status of the detector and presents several analyses carried out on
atmospheric muons and neutrinos. For example it shows the results from the
measurement of atmospheric muon neutrino spectrum and of atmospheric neutrino
oscillation parameters as well as searches for neutrinos from steady cosmic
point-like sources, for neutrinos from gamma ray bursts and for relativistic
magnetic monopoles.


title: Approximating chiral SU(3) amplitudes

abstract:
  We construct large-N_c motivated approximate chiral SU(3) amplitudes of
next-to-next-to-leading order. The amplitudes are independent of the
renormalization scale. Fitting lattice data with those amplitudes allows for
the extraction of chiral coupling constants with the correct scale dependence.
The differences between approximate and full amplitudes are required to be at
most of the order of N^3LO contributions numerically. Applying the approximate
expressions to recent lattice data for meson decay constants, we determine
several chiral couplings with good precision. In particular, we obtain a value
for F_0, the meson decay constant in the chiral SU(3) limit, that is more
precise than all presently available determinations.


title: Images of Rational Maps of Projective Spaces

abstract:
  Consider a rational map from a projective space to a product of projective
spaces, induced by a collection of linear projections. Motivated by the the
theory of limit linear series and Abel-Jacobi maps, we study the basic
properties of the closure of the image of the rational map using a combination
of techniques of moduli functors and initial degenerations. We first give a
formula of multi-degree in terms of the dimensions of intersections of linear
subspaces and then prove that it is Cohen-Macaulay. Finally, we compute its
Hilbert polynomials.


title: Magnetization Transfer by a Quantum Ring Device

abstract:
  We show that a tight-binding model device consisting of a laterally connected
ring at half filling in a tangent time-dependent magnetic field can in
principle be designed to pump a purely spin current. The process exploits the
spin-orbit interaction in the ring. This behavior is understood analytically
and found to be robust with respect to temperature and small deviations from
half filling.


title:
Composing and Factoring Generalized Green's Operators and Ordinary
  Boundary Problems

abstract:
  We consider solution operators of linear ordinary boundary problems with "too
many" boundary conditions, which are not always solvable. These generalized
Green's operators are a certain kind of generalized inverses of differential
operators. We answer the question when the product of two generalized Green's
operators is again a generalized Green's operator for the product of the
corresponding differential operators and which boundary problem it solves.
Moreover, we show that---provided a factorization of the underlying
differential operator---a generalized boundary problem can be factored into
lower order problems corresponding to a factorization of the respective Green's
operators. We illustrate our results by examples using the Maple package
IntDiffOp, where the presented algorithms are implemented.


title: Optimal Checkpointing Period: Time vs. Energy

abstract:
  This short paper deals with parallel scientific applications using
non-blocking and periodic coordinated checkpointing to enforce resilience. We
provide a model and detailed formulas for total execution time and consumed
energy. We characterize the optimal period for both objectives, and we assess
the range of time/energy trade-offs to be made by instantiating the model with
a set of realistic scenarios for Exascale systems. We give a particular
emphasis to I/O transfers, because the relative cost of communication is
expected to dramatically increase, both in terms of latency and consumed
energy, for future Exascale platforms.


title: Critique of Fault-Tolerant Quantum Information Processing

abstract:
  This is a chapter in a book \emph{Quantum Error Correction} edited by D. A.
Lidar and T. A. Brun, and published by Cambridge University Press (2013)\\
(http://www.cambridge.org/us/academic/subjects/physics/quantum-physics-quantum-information-and-quantum-computation/quantum-error-correction)\\
presenting the author's view on feasibility of fault-tolerant quantum
information processing.


title:
Hybridized discontinuous Galerkin method for convection-diffusion
  problems

abstract:
  In this paper, we propose a new hybridized discontinuous Galerkin (DG) method
for the convection-diffusion problems with mixed boundary conditions. A feature
of the proposed method, is that it can greatly reduce the number of
globally-coupled degrees of freedom, compared with the classical DG methods.
The coercivity of a convective part is achieved by adding an upwinding term. We
give error estimates of optimal order in the piecewise $H^1$-norm for general
convection-diffusion problems. Furthermore, we prove that the approximate
solution given by our scheme is close to the solution of the purely convective
problem when the viscosity coefficient is small. Several numerical results are
presented to verify the validity of our method.


title:
Neutrino coupling to cosmological background: A review on gravitational
  Baryo/Leptogenesis

abstract:
  In this work we review the theories of origin of matter-antimatter asymmetry
in the Universe. The general conditions for achieving baryogenesis and
leptogenesis in a CPT conserving field theory have been laid down by Sakharov.
In this review we discuss scenarios where a background scalar or gravitational
field spontaneously breaks the CPT symmetry and splits the energy levels
between particles and anti-particles. Baryon or Lepton number violating
processes in proceeding at thermal equilibrium in such backgrounds gives rise
to Baryon or Lepton number asymmetry.


title: Dusty Universe viewed by AKARI far infrared detector

abstract:
  We present the results of the analysis of multiwavelength Spectral Energy
Distributions (SEDs) of far-infrared galaxies detected in the AKARI Deep
Field-South (ADF--S) Survey. The analysis uses a carefully selected sample of
186 sources detected at the 90 $\mu$m AKARI band, identified as galaxies with
cross-identification in public catalogues. For sources without known
spectroscopic redshifts, we estimate photometric redshifts after a test of two
independent methods: one based on using mainly the optical -- mid infrared
range, and one based on the whole range of ultraviolet -- far infrared data. We
observe a vast improvement in the estimation of photometric redshifts when far
infrared data are included, compared with an approach based mainly on the
optical -- mid infrared range. We discuss the physical properties of our
far-infrared-selected sample. We conclude that this sample consists mostly of
rich in dust and young stars nearby galaxies, and, furthermore, that almost 25%
of these sources are (Ultra)Luminous Infrared Galaxies. Average SEDs normalized
at 90 $\mu$m for normal galaxies (138 sources), LIRGs (30 sources), and ULIRGs
(18 galaxies) a the significant shift in the peak wavelength of the dust
emission, and an increasing ratio between their bolometric and dust
luminosities which varies from 0.39 to 0.73.


title: A conjecture on the primitive degree of Tensors

abstract:
  In this paper, we prove: Let A be a nonnegative primitive tensor with order m
and dimension n. Then its primitive degree R(A)\leq (n-1)^2+1, and the upper
bound is sharp. This confirms a conjecture of Shao [7].


title: Application of Data Mining In Marketing

abstract:
  One of the most important problems in modern finance is finding efficient
ways to summarize and visualize the stock market data to give individuals or
institutions useful information about the market behavior for investment
decisions. The enormous amount of valuable data generated by the stock market
has attracted researchers to explore this problem domain using different
methodologies. Potential significant benefits of solving these problems
motivated extensive research for years. The research in data mining has gained
a high attraction due to the importance of its applications and the increasing
generation information. This paper provides an overview of application of data
mining techniques such as decision tree. Also, this paper reveals progressive
applications in addition to existing gap and less considered area and
determines the future works for researchers.


title:
Study of n-{\gamma} discrimination in low energy range (above 40 keVee)
  by charge comparison method with a BC501A liquid scintillation detector

abstract:
  A VME-based experiment system for n-{\gamma} discrimination using the charge
comparison method was established. A data acquisition program for controlling
the programmable modules and processing data online via VME64X bus was
developed through the use of LabVIEW. The two-dimensional (2D) scatter plots of
the charge in the slow component vs. the total charge of recorded pulses from
Am-Be and Cf neutron sources were presented. The 2D scatter plots of the energy
vs. the ratio of the charge in the slow component to the total charge of the
pulses were presented at the meantime. The quality of n-{\gamma} discrimination
was checked by the figure-of-merit, and the results showed good performance of
n-{\gamma} discrimination at low energy range. Neutrons and {\gamma}-rays were
separated above 50 keVee (electron-equivalent energy). The quality of
n-{\gamma} discrimination have been improved compared with others' results at 5
energies (150, 250, 350, 450, 550 keVee).


title:
Systems of transversal sections near critical energy levels of
  Hamiltonian systems in $\mathbb{R}^4$

abstract:
  In this article we study Hamiltonian flows associated to smooth functions
$H:\mathbb{R}^4 \to \mathbb{R}$ restricted to energy levels close to critical
levels. We assume the existence of a saddle-center equilibrium point $p_c$ in
the zero energy level $H^{-1}(0)$. The Hamiltonian function near $p_c$ is
assumed to satisfy Moser's normal form and $p_c$ is assumed to lie in a
strictly convex singular subset $S_0$ of $H^{-1}(0)$. Then for all $E>0$ small,
the energy level $H^{-1}(E)$ contains a subset $S_E$ near $S_0$, diffeomorphic
to the closed $3$-ball, which admits a system of transversal sections
$\mathcal{F}_E$, called a $2-3$ foliation. $\mathcal{F}_E$ is a singular
foliation of $S_E$ and contains two periodic orbits $P_{2,E}\subset \partial
S_E$ and $P_{3,E}\subset S_E\setminus \partial S_E$ as binding orbits.
$P_{2,E}$ is the Lyapunoff orbit lying in the center manifold of $p_c$, has
Conley-Zehnder index $2$ and spans two rigid planes in $\partial S_E$.
$P_{3,E}$ has Conley-Zehnder index $3$ and spans a one parameter family of
planes in $S_E \setminus \partial S_E$. A rigid cylinder connecting $P_{3,E}$
to $P_{2,E}$ completes $\mathcal{F}_E$. All regular leaves are transverse to
the Hamiltonian vector field. The existence of a homoclinic orbit to $P_{2,E}$
in $S_E\setminus \partial S_E$ follows from this foliation.


title: Systematic errors in current quantum state tomography tools

abstract:
  Common tools for obtaining physical density matrices in experimental quantum
state tomography are shown here to cause systematic errors. For example, using
maximum likelihood or least squares optimization for state reconstruction, we
observe a systematic underestimation of the fidelity and an overestimation of
entanglement. A solution for this problem can be achieved by a linear
evaluation of the data yielding reliable and computational simple bounds
including error bars.


title: The impact of freeze-out on collapsing molecular clouds

abstract:
  Atoms and molecules, and in particular CO, are important coolants during the
evolution of interstellar star-forming gas clouds. The presence of dust grains,
which allow many chemical reactions to occur on their surfaces, strongly
impacts the chemical composition of a cloud. At low temperatures, dust grains
can lock-up species from the gas phase which freeze out and form ices. In this
sense, dust can deplete important coolants. Our aim is to understand the
effects of freeze-out on the thermal balance and the evolution of a
gravitationally bound molecular cloud. For this purpose, we perform 3D
hydrodynamical simulations with the adaptive mesh code FLASH. We simulate a
gravitationally unstable cloud under two different conditions, with and without
grain surface chemistry. We let the cloud evolve until one free-fall time is
reached and track the thermal evolution and the abundances of species during
this time. We see that at a number density of 10$^4$ cm$^{-3}$ most of the CO
molecules are frozen on dust grains in the run with grain surface chemistry,
thereby depriving the most important coolant. As a consequence, we find that
the temperature of the gas rises up to $\sim$25 K. The temperature drops once
again due to gas-grain collisional cooling when the density reaches a
few$\times$10$^4$ cm$^{-3}$. We conclude that grain surface chemistry not only
affects the chemical abundances in the gas phase, but also leaves a distinct
imprint in the thermal evolution that impacts the fragmentation of a
star-forming cloud. As a final step, we present the equation of state of a
collapsing molecular cloud that has grain surface chemistry included.


title: Reinforcement Learning Framework for Opportunistic Routing in WSNs

abstract:
  Routing packets opportunistically is an essential part of multihop ad hoc
wireless sensor networks. The existing routing techniques are not adaptive
opportunistic. In this paper we have proposed an adaptive opportunistic routing
scheme that routes packets opportunistically in order to ensure that packet
loss is avoided. Learning and routing are combined in the framework that
explores the optimal routing possibilities. In this paper we implemented this
Reinforced learning framework using a customer simulator. The experimental
results revealed that the scheme is able to exploit the opportunistic to
optimize routing of packets even though the network structure is unknown.


title: Sparse Signal Recovery from Nonadaptive Linear Measurements

abstract:
  The theory of Compressed Sensing, the emerging sampling paradigm 'that goes
against the common wisdom', asserts that 'one can recover signals in Rn from
far fewer samples or measurements, if the signal has a sparse representation in
some orthonormal basis', from m = O(klogn), k<< n nonadaptive measurements .
The accuracy of the recovered signal is 'as good as that attainable with direct
knowledge of the k most important coefficients and its locations'. Moreover, a
good approximation to those important coefficients is extracted from the
measurements by solving a L1 minimization problem viz. Basis Pursuit. 'The
nonadaptive measurements have the character of random linear combinations of
the basis/frame elements'.
  The theory has implications which are far reaching and immediately leads to a
number of applications in Data Compression,Channel Coding and Data Acquisition.
'The last of these applications suggest that CS could have an enormous impact
in areas where conventional hardware design has significant limitations',
leading to 'efficient and revolutionary methods of data acquisition and storage
in future'.
  The paper reviews fundamental mathematical ideas pertaining to compressed
sensing viz. sparsity, incoherence, reduced isometry property and basis
pursuit, exemplified by the sparse recovery of a speech signal and convergence
of the L1- minimization algorithm.


title:
The matrix method of representation, analysis and classification of long
  genetic sequences

abstract:
  The article is devoted to a matrix method of comparative analysis of long
nucleotide sequences by means of a presentation of each sequence in a form of
three digital binary sequences. This method uses biochemical attributes of
nucleotides and it also uses a possibility of presentation of every whole set
of n-mers in a form of one of members of a Kronecker family of genetic
matrices. Due to this method, a long nucleotide sequence can be visually
represented as an individual fractal-like mosaic or another regular mosaic of
binary type. In contrast to natural nucleotide sequences, artificial random
sequences give non-regular patterns. Examples of binary mosaics of long
nucleotide sequences are shown, including cases of human chromosomes and
penicillins. Interpretation of binary presentations of nucleotide sequences
from the point of view of Gray code is also tested. Possible reasons of genetic
meaning of Kronecker multiplication of matrices are analyzed. The received
results are discussed.


title:
A direct comparison of CVD-grown and exfoliated MoS2 using optical
  spectroscopy

abstract:
  MoS2 is a highly interesting material system, which exhibits a crossover from
an indirect band gap in the bulk crystal to a direct gap for single layers.
Here, we perform a direct comparison between large-area MoS$_2$ films grown by
chemical vapor deposition (CVD) and MoS$_2$ flakes prepared by mechanical
exfoliation from natural bulk crystal. Raman spectroscopy measurements show
differences between the in-plane and out-of-plane phonon mode positions in
CVD-grown and exfoliated MoS$_2$. Photoluminescence (PL) mapping reveals large
regions in the CVD-grown films that emit strong PL at room temperature, and
low-temperature PL scans demonstrate a large spectral shift of the A exciton
emission as a function of position. Polarization-resolved PL measurements under
near-resonant excitation conditions show a strong circular polarization of the
PL, corresponding to a valley polarization.


title: The partial $C^0$-estimate along the continuity method

abstract:
  We prove that the partial $C^0$-estimate holds for metrics along Aubin's
continuity method for finding K\"ahler-Einstein metrics, confirming a special
case of a conjecture due to Tian. We use the method developed in recent work of
Chen-Donaldson-Sun on the analogous problem for conical K\"ahler-Einstein
metrics.


title:
Amoebas, Ronkin function and Monge-Amp\`ere measures of algebraic curves
  with marked points

abstract:
  A generalization of the amoeba and the Ronkin function of a plane algebraic
curve for a pair of harmonic functions on an algebraic curve with punctures is
proposed. Extremal properties of $M$-curves are proved and connected with the
spectral theory of difference operators with positive coefficients.


title:
Stationary states of fermions in a sign potential with a mixed
  vector-scalar coupling

abstract:
  The scattering of a fermion in the background of a sign potential is
considered with a general mixing of vector and scalar Lorentz structures with
the scalar coupling stronger than or equal to the vector coupling under the
Sturm-Liouville perspective. When the vector coupling and the scalar coupling
have different magnitudes, an isolated solution shows that the fermion under a
strong potential can be trapped in a highly localized region without
manifestation of Klein's paradox. It is also shown that the lonely bound-state
solution disappears asymptotically as one approaches the conditions for the
realization of spin and pseudospin symmetries.


title:
Nonisothermal nematic liquid crystal flows with the Ball-Majumdar free
  energy

abstract:
  In this paper we prove the existence of global in time weak solutions for an
evolutionary PDE system modelling nonisothermal Landau-de Gennes nematic liquid
crystal (LC) flows in three dimensions of space. In our model, the
incompressible Navier-Stokes system for the macroscopic velocity $\vu$ is
coupled to a nonlinear convective parabolic equation describing the evolution
of the Q-tensor $\QQ$, namely a tensor-valued variable representing the
normalized second order moments of the probability distribution function of the
LC molecules. The effects of the (absolute) temperature $\vt$ are prescribed in
the form of an energy balance identity complemented with a global entropy
production inequality. Compared to previous contributions, we can consider here
the physically realistic singular configuration potential $f$ introduced by
Ball and Majumdar. This potential gives rise to severe mathematical
difficulties since it introduces, in the Q-tensor equation, a term which is at
the same time singular in $\QQ$ and degenerate in $\vt$. To treat it a careful
analysis of the properties of $f$, particularly of its blow-up rate, is carried
out.


title: The Jamming Constant of Uniform Random Graphs

abstract:
  By constructing jointly a random graph and an associated exploration process,
we define the dynamics of a "parking process" on a class of uniform random
graphs as a measure-valued Markov process, representing the empirical degree
distribution of non-explored nodes. We then establish a functional law of large
numbers for this process as the number of vertices grows to infinity, allowing
us to assess the jamming constant of the considered random graphs, i.e. the
size of the maximal independent set discovered by the exploration algorithm.
This technique, which can be applied to any uniform random graph with a given
degree distribution, can be seen as a generalization in the space of measures,
of the differential equation method introduced by Wormald.


title:
A simplified density functional theory method for charged adsorbates on
  an ultrathin, insulating film supported by a metal substrate

abstract:
  A simplified density functional theory (DFT) method for charged adsorbates on
an ultrathin, insulating film supported by a metal substrate is developed and
presented. This new method is based on a previous DFT development that uses a
perfect conductor (PC) model to approximate the electrostatic response of the
metal substrate, while the film and the adsorbate are both treated fully within
DFT [I. Scivetti and M. Persson, Journal of Physics: Condensed Matter 25,
355006 (2013)]. The missing interactions between the metal substrate and the
insulating film in the PC approximation are modelled by a simple force field
(FF). The parameters of the PC model and the force field are obtained from DFT
calculations of the film and the substrate, here shown explicitly for a NaCl
bilayer supported by a Cu(100) surface. In order to obtain some of these
parameters and the polarisability of the force field, we have to include an
external, uniformly charged plane in the DFT calculations, which has required
the development of a periodic DFT formalism to include such a charged plane in
the presence of a metal substrate. This extension and implementation should be
of more general interest and applicable to other challenging problems, for
instance, in electrochemistry. As illustrated for the gold atom on the NaCl
bilayer supported by a Cu(100) surface, our new DFT-PC-FF method allows us to
handle different charge states of adsorbates in a controlled and accurate
manner with a considerable reduction of the computational time. In addition, it
is now possible to calculate vertical transition and reorganisation energies
for charging and discharging of adsorbates that cannot be obtained by current
DFT methodologies that include the metal substrate. We find that the computed
vertical transition energy for charging of the gold adatom is in good agreement
with experiments.


title: Tunka-Rex: Status and Results of the First Measurements (RICAP 2013)

abstract:
  Tunka-Rex is the radio extension of Tunka-133 located in Siberia close to
Lake Baikal. The latter is a photomultiplier array registering air-Cherenkov
light from air showers induced by cosmic-ray particles with initial energies of
approximately $10^{16}$ to $10^{18}$ eV. Tunka-Rex extends this detector with
25 antennas spread over an area of 1 km$^2$. It is triggered externally by
Tunka-133, and detects the radio emission of the same air showers. The
combination of an air-Cherenkov and a radio detector provides a facility for
hybrid measurements and cross-calibration between the two techniques. The main
goal of Tunka-Rex is to determine the precision of the reconstruction of
air-shower parameters using the radio detection technique. It started operation
in autumn 2012. We present the overall concept of Tunka-Rex, the current status
of the array and first analysis results.


title:
Distributed simulation of polychronous and plastic spiking neural
  networks: strong and weak scaling of a representative mini-application
  benchmark executed on a small-scale commodity cluster

abstract:
  We introduce a natively distributed mini-application benchmark representative
of plastic spiking neural network simulators. It can be used to measure
performances of existing computing platforms and to drive the development of
future parallel/distributed computing systems dedicated to the simulation of
plastic spiking networks. The mini-application is designed to generate spiking
behaviors and synaptic connectivity that do not change when the number of
hardware processing nodes is varied, simplifying the quantitative study of
scalability on commodity and custom architectures. Here, we present the strong
and weak scaling and the profiling of the computational/communication
components of the DPSNN-STDP benchmark (Distributed Simulation of Polychronous
Spiking Neural Network with synaptic Spike-Timing Dependent Plasticity). In
this first test, we used the benchmark to exercise a small-scale cluster of
commodity processors (varying the number of used physical cores from 1 to 128).
The cluster was interconnected through a commodity network. Bidimensional grids
of columns composed of Izhikevich neurons projected synapses locally and toward
first, second and third neighboring columns. The size of the simulated network
varied from 6.6 Giga synapses down to 200 K synapses. The code demonstrated to
be fast and scalable: 10 wall clock seconds were required to simulate one
second of activity and plasticity (per Hertz of average firing rate) of a
network composed by 3.2 G synapses running on 128 hardware cores clocked @ 2.4
GHz. The mini-application has been designed to be easily interfaced with
standard and custom software and hardware communication interfaces. It has been
designed from its foundation to be natively distributed and parallel, and
should not pose major obstacles against distribution and parallelization on
several platforms.


title:
Interface originated modification of electron-vibration coupling in
  resonant photoelectron spectroscopy

abstract:
  We present a comprehensive study of the photon energy ($h \nu$) dependent
line-shape evolution of molecular orbital signals of large $\pi$-conjugated
molecules by resonant photoelectron spectroscopy (RPES). A comparison to RPES
data of small molecules suggests that the excitation into different vibrational
levels on the intermediate state potential energy surface of the electronic
excitation is responsible for the observed effect. In this simplified picture
of electron-vibration couping the character of the potential energy surfaces
involved in the RPES process determines the line-shape of the molecular orbital
signal for a particular $h \nu$. We use the sensitivity of this effect to probe
the influence of different interfaces on the electron-vibration coupling in the
investigated systems. The magnitude of the variation in line-shape throughout
the particular $h \nu$ region allows to reveal significant differences within
the physisorptive regime.


title:
Remarks on the analyticity of subadditive pressure for products of
  triangular matrices

abstract:
  We study Falconer's subadditive pressure function with emphasis on
analyticity. We begin by deriving a simple closed form expression for the
pressure in the case of diagonal matrices and, by identifying phase transitions
with zeros of Dirichlet polynomials, use this to deduce that the pressure is
piecewise real analytic. We then specialise to the iterated function system
setting and use a result of Falconer and Miao to extend our results to include
the pressure for systems generated by matrices which are simultaneously
triangularisable. Our closed form expression for the pressure simplifies a
similar expression given by Falconer and Miao by reducing the number of
equations needing to be solved by an exponential factor. Finally we present
some examples where the pressure has a phase transition at a non-integer value
and pose some open questions.


title: A Keplerian disk around a Class 0 source: ALMA observations of VLA1623A

abstract:
  Context: Rotationally supported disks are critical in the star formation
process. The questions of when do they form and what factors influence or
hinder their formation have been studied but are largely unanswered.
Observations of early stage YSOs are needed to probe disk formation. Aims:
VLA1623 is a triple non-coeval protostellar system, with a weak magnetic field
perpendicular to the outflow, whose Class 0 component, VLA1623A, shows a
disk-like structure in continuum with signatures of rotation in line emission.
We aim to determine whether this structure is in part or in whole a
rotationally supported disk, i.e. a Keplerian disk, and what are its
characteristics. Methods: ALMA Cycle 0 Early Science 1.3 mm continuum and
C$^{18}$O (2-1) observations in the extended configuration are presented here
and used to perform an analysis of the disk-like structure using PV diagrams
and thin disk modelling with the addition of foreground absorption. Results:
The PV diagrams of the C$^{18}$O line emission suggest the presence of a
rotationally supported component with a radius of at least 50 AU. Kinematical
modelling of the line emission shows that the disk out to 180 AU is actually
rotationally supported, with the rotation being well described by Keplerian
rotation out to at least 150 AU, and the central source mass to be $\sim$0.2
M$_{sun}$ for an inclination of 55$^{\circ}$. Pure infall and conserved angular
momentum rotation models are excluded. Conclusions: VLA1623A, a very young
Class 0 source, presents a disk with an outer radius $R_{\rm out}$ = 180 AU
with a Keplerian velocity structure out to at least 150 AU. The weak magnetic
fields and recent fragmentation in this region of rho Ophiuchus may have played
a lead role in the formation of the disk.


title:
Simulation of counter flow pedestrian dynamics in hallways using
  spheropolygons

abstract:
  We developed a method for simulating pedestrian dynamics in a large, dense
crowd. Our numerical model calculates pedestrian motion from Newton second
laws, taking into account visco-elastic contact forces, contact friction, and
ground reaction forces. In our computer simulation, non-spherical shapes
(spheropolygons) modelled the positions of the chest and arms in the packing
arrangement of pedestrian bodies, based on a cross-sectional profile using data
from the US National Library of Medicine. Motive torque was taken to arise
solely from the pedestrians orientation toward their preferred destination. The
objective was to gain insight into a tragic incident at the Madrid Arena
Pavilion in Spain, where five girls were crushed to death. The incident took
place at a Halloween Celebration in 2012, in a long, densely crowded hallway
used as entrance and exit at the same time. Our simulations reconstruct the
mechanics of clogging in the hallway. The hypothetical case of a total
evacuation order was also investigated. The result highlights the importance of
the pedestrians density and the effect of counter flow in the onset of
avalanches and clogging, and provides qualitative measures of the number of
injuries based on a calculation of the contact force network between the
pedestrians.


title: 2D Quantum Double Models From a 3D Perspective

abstract:
  In this paper we look at 3D lattice models that are generalizations of the
state sum model used to define the Kuperberg invariant of 3-manifolds. The
partition function is a scalar constructed as a tensor network where the
building blocks are tensors given by the structure constants of an involutary
Hopf algebra $\mathcal{A}$. These models are very general and are hard to solve
in its entire parameter space. One can obtain familiar models, such as ordinary
gauge theories, by letting $\mathcal{A}$ be the group algebra $\mathbb{C}(G)$
of a discrete group $G$ and staying on a certain region of the parameter space.
We consider the transfer matrix of the model and show that Quantum double
Hamiltonians are derived from a particular choice of the parameters. Such a
construction naturally leads to the star and plaquette operators of the quantum
double Hamiltonians, of which the toric code is a special case when
$\mathcal{A}=\mathbb{C}(\mathbb{Z}_2)$. This formulation is convenient to study
ground states of these generalized quantum double models where they can
naturally be interpreted as tensor network states. For a surface $\Sigma$, the
ground state degeneracy is determined by the Kuperberg 3-manifold invariant of
$\Sigma\times S^1$. It is also possible to obtain extra models by simple
enlarging the allowed parameter space but keeping the solubility of the model.
While some of these extra models have appeared before in the literature, our 3D
perspective allows for an uniform description of them.


title: The process $e^+e^- \to \eta(\eta')2\pi$ in the extended NJL model

abstract:
  Process of electron-positron annihilation into $\eta(\eta')2\pi$ is described
within the extended NJL model in the energy range up to about 2 GeV.
Contributions of intermediate vector mesons $\rho(770)$ and $\rho(1450)$ are
taken into account. Results for the $\eta2\pi$ channel are found to be in a
reasonable agreement with experimental data. Predictions for production of
$\eta' 2\pi$ are given. The corresponding estimations for decays
$\tau\to\eta(\eta')2\pi\nu$ are given in Appendix.


title: SU(2)-invariant depolarization of quantum states of light

abstract:
  We develop an SU(2)-invariant approach to the depolarization of quantum
systems as the effect of random unitary SU(2) transformations. From it we
derive an SU(2)-invariant Markovian master equation. This is applied to several
quantum states examining whether nonclassical states are more sensible to
depolarization than the classical ones. Furthermore, we show that this
depolarization model provides a nontrivial generalization of depolarization
channels to states of arbitrary dimension.