title: Dimensions, Structures and Security of Networks

abstract:
  One of the main issues in modern network science is the phenomenon of
cascading failures of a small number of attacks. Here we define the dimension
of a network to be the maximal number of functions or features of nodes of the
network. It was shown that there exist linear networks which are provably
secure, where a network is linear, if it has dimension one, that the high
dimensions of networks are the mechanisms of overlapping communities, that
overlapping communities are obstacles for network security, and that there
exists an algorithm to reduce high dimensional networks to low dimensional ones
which simultaneously preserves all the network properties and significantly
amplifies security of networks. Our results explore that dimension is a
fundamental measure of networks, that there exist linear networks which are
provably secure, that high dimensional networks are insecure, and that security
of networks can be amplified by reducing dimensions.


title:
Community Structures Are Definable in Networks, and Universal in Real
  World

abstract:
  Community detecting is one of the main approaches to understanding networks
\cite{For2010}.
  However it has been a longstanding challenge to give a definition for
community structures of networks. Here we found that community structures are
definable in networks, and are universal in real world. We proposed the notions
of entropy- and conductance-community structure ratios. It was shown that the
definitions of the modularity proposed in \cite{NG2004}, and our entropy- and
conductance-community structures are equivalent in defining community
structures of networks, that randomness in the ER model \cite{ER1960} and
preferential attachment in the PA \cite{Bar1999} model are not mechanisms of
community structures of networks, and that the existence of community
structures is a universal phenomenon in real networks. Our results demonstrate
that community structure is a universal phenomenon in the real world that is
definable, solving the challenge of definition of community structures in
networks. This progress provides a foundation for a structural theory of
networks.


title: Homophyly Networks -- A Structural Theory of Networks

abstract:
  A grand challenge in network science is apparently the missing of a
structural theory of networks. The authors have showed that the existence of
community structures is a universal phenomenon in real networks, and that
neither randomness nor preferential attachment is a mechanism of community
structures of network \footnote{A. Li, J. Li, and Y. Pan, Community structures
are definable in networks, and universal in the real world, To appear.}. This
poses a fundamental question: What are the mechanisms of community structures
of real networks? Here we found that homophyly is the mechanism of community
structures and a structural theory of networks. We proposed a homophyly model.
It was shown that networks of our model satisfy a series of new topological,
probabilistic and combinatorial principles, including a fundamental principle,
a community structure principle, a degree priority principle, a widths
principle, an inclusion and infection principle, a king node principle, and a
predicting principle etc, leading to a structural theory of networks. Our model
demonstrates that homophyly is the underlying mechanism of community structures
of networks, that nodes of the same community share common features, that power
law and small world property are never obstacles of the existence of community
structures in networks, and that community structures are definable in
networks.


title:
The Use of Numeraires in Multi-dimensional Black-Scholes Partial
  Differential Equations

abstract:
  The change of numeraire gives very important computational simplification in
option pricing. This technique reduces the number of sources of risks that need
to be accounted for and so it is useful in pricing complicated derivatives that
have several sources of risks. In this article, we considered the underlying
mathematical theory of numeraire technique in the viewpoint of PED theory and
illustrated it with five concrete pricing problems. In the viewpoint of PED
theory, the numeraire technique is a method of reducing the dimension of status
spaces where PDE is defined.


title:
Constraints on variations of m$_\mathrm{p}$/m$_\mathrm{e}$ based on UVES
  observations of H$_2$

abstract:
  This article summarizes the latest results on the proton-to-electron mass
ratio $\mu$ derived from H$_2$ observations at high redshift in the light of
possible variations of fundamental physical constants.
  The focus lies on UVES observations of the past years as enormous progress
was achieved since the first positive results on $\Delta\mu/\mu$ were
published. With the better understanding of systematics, dedicated observation
runs, and numerous approaches to improve wavelength calibration accuracy, all
current findings are in reasonable good agreement with no variation and provide
an upper limit of $\Delta\mu/\mu$ $< 1\times 10^{-5}$ for the redshift range of
$2 <$ z $< 3$.


title:
Tracing the evolution of Active Galactic Nuclei host galaxies over the
  last 9 Gyrs of Cosmic time

abstract:
  We present the results of a combined galaxy population analysis for the host
galaxies of active galactic nuclei (AGN) identified at 0 < z < 1.4 within the
SDSS, Bootes and DEEP2 surveys. We identified AGN in a uniform and unbiased
manner at X-ray, infrared and radio wavelengths. Supermassive black holes
undergoing radiatively-efficient accretion (detected as X-ray and/or infrared
AGN) appear to be hosted in a separate and distinct galaxy population than AGN
undergoing powerful mechanically dominated accretion (radio AGN). Consistent
with some previous studies, radiatively efficient AGN appear to be
preferentially hosted in modest star-forming galaxies, with little dependence
on AGN or galaxy luminosity. AGN exhibiting radio-emitting jets due to
mechanically-dominated accretion are almost exclusively observed in massive,
passive galaxies. Crucially, we now provide strong evidence that the observed
host-galaxy trends are independent of redshift. In particular, these different
accretion-mode AGN have remained as separate galaxy populations throughout the
last 9 Gyr. Furthermore, it appears that galaxies hosting AGN have evolved
along the same path as galaxies that are not hosting AGN with little evidence
for distinctly separate evolution.


title:
A UV-to-MIR monitoring of DR Tau: exploring how water vapor in the
  planet formation region of the disk is affected by stellar accretion
  variability

abstract:
  Young stars are known to show variability due to non-steady mass accretion
rate from their circumstellar disks. Accretion flares can produce strong
energetic irradiation and heating that may affect the disk in the planet
formation region, close to the central star. During an extreme accretion
outburst in the young star EX Lupi, the prototype of EXor variables, remarkable
changes in molecular gas emission from $\sim1$ AU in the disk have recently
been observed (Banzatti et al. 2012). Here, we focus on water vapor and explore
how it is affected by variable accretion luminosity in T Tauri stars. We
monitored a young highly variable solar-mass star, DR Tau, using simultaneously
two high/medium-resolution ESO-VLT spectrographs: VISIR at 12.4 $\mu$m to
observe water lines from the disk, and X-shooter covering from 0.3 to 2.5
$\mu$m to constrain the stellar accretion. Three epochs spanning timescales
from several days to several weeks were obtained. Accretion luminosity was
estimated to change within a factor $\sim2$, and no change in water emission
was detected at a significant level. In comparison to EX Lupi and EXor
outbursts, DR Tau suggests that the less long-lived and weaker variability
phenomena typical of T Tauri stars may leave water at planet-forming radii in
the disk mostly unaffected. We propose that these systems may provide evidence
for two processes that act over different timescales: UV photochemistry in the
disk atmosphere (faster) and heating of the disk deeper layers (slower).


title: Accelerated Universes from type IIA Compactifications

abstract:
  We study slow-roll accelerating cosmologies arising from geometric
compactifications of type IIA string theory on
$T^{6}/(\mathbb{Z}_{2}\,\times\,\mathbb{Z}_{2})$. With the aid of a genetic
algorithm, we are able to find quasi-de Sitter backgrounds with both slow-roll
parameters of order $0.1$. Furthermore, we study their evolution by numerically
solving the corresponding time-dependent equations of motion, and we show that
they actually display a few e-folds of accelerated expansion. Finally, we
comment on their perturbative reliability.


title:
Modeling Gas Evacuation Mechanisms in Present-Day Globular Clusters:
  Stellar Winds from Evolved Stars and Pulsar Heating

abstract:
  We employ hydrodynamical simulations to investigate the underlying mechanism
responsible for the low levels of gas and dust in globular clusters. Our models
examine the competing effects of energy and mass supply from the various
components of the evolved stellar population for globular clusters 47 Tucanae,
M15, NGC 6440, and NGC 6752. Ignoring all other gas evacuation processes, we
find that the energy output from the stars that have recently turned off the
main sequence are capable of effectively clearing the evolved stellar ejecta
and producing intracluster gas densities consistent with current observational
constraints. This result distinguishes a viable gas and dust evacuation
mechanism that is ubiquitous in globular clusters. In addition, we extend our
analysis to probe the efficiency of pulsar wind feedback in globular clusters.
The detection of intracluster ionized gas in 47~Tucanae allows us to place
particularly strict limits on pulsar wind thermalization efficiency, which must
be extremely low in the cluster's core in order to be in accordance with the
observed density constraints.


title:
No $\psi$-epistemic model can fully explain the indistinguishability of
  quantum states

abstract:
  According to a recent no-go theorem (M. Pusey, J. Barrett and T. Rudolph,
Nature Physics 8, 475 (2012)), models in which quantum states correspond to
probability distributions over the values of some underlying physical variables
must have the following feature: the distributions corresponding to distinct
quantum states do not overlap. This is significant because if the distributions
do not overlap, then the quantum state itself is encoded by the physical
variables. In such a model, it cannot coherently be maintained that the quantum
state merely encodes information about underlying physical variables. The
theorem, however, considers only models in which the physical variables
corresponding to independently prepared systems are independent. This work
considers models that are defined for a single quantum system of dimension $d$,
such that the independence condition does not arise. We prove a result in a
similar spirit to the original no-go theorem, in the form of an upper bound on
the extent to which the probability distributions can overlap, consistently
with reproducing quantum predictions. In particular, models in which the
quantum overlap between pure states is equal to the classical overlap between
the corresponding probability distributions cannot reproduce the quantum
predictions in any dimension $d \geq 3$. The result is noise tolerant, and an
experiment is motivated to distinguish the class of models ruled out from
quantum theory.


title:
Black Holes in Short Period X-ray Binaries and the Transition to
  Radiatively Inefficient Accretion

abstract:
  By comparing the orbital period distributions of black hole and neutron star
low mass X-ray binaries (LMXBs) in the Ritter-Kolb catalogue we show that there
is statistical evidence for a dearth of black hole systems at short orbital
periods (P_orb < 4h). This could either be due to a true divergence in orbital
period distributions of these two types of system, or to black hole LMXBs being
preferentially hidden from view at short orbital periods. We explore the latter
possibility, by investigating whether black hole LMXBs could be concealed by a
switch to radiatively inefficient accretion at low luminosities. The peak
luminosity and the duration of X-ray binary outbursts are related to the disc
radius and, hence, the orbital period. At short periods, where the peak
outburst luminosity drops close to the threshold for radiatively inefficient
accretion, black hole LMXBs have lower outburst luminosities, shorter outburst
durations and lower X-ray duty cycles than comparable neutron star systems.
These factors can combine to severely reduce the detection probability of short
period black hole LMXBs relative to those containing neutron stars. We estimate
the outburst properties and orbital period distribution of black hole LMXBs
using two models of the transition to radiatively inefficient accretion: an
instantaneous drop in accretion efficiency (eta) to zero, at a fraction (f) of
the Eddington luminosity (L_Edd) and a power-law efficiency decrease, eta
\propto \dot{M}^n, for L < f*L_Edd. We show that a population of black hole
LMXBs at short orbital periods can only be hidden by a sharp drop in
efficiency, either instantaneous or for n >= 3. This could be achieved by a
genuine drop in luminosity or through abrupt spectral changes that shift the
accretion power out of a given X-ray band.


title:
A catalog of bulge, disk, and total stellar mass estimates for the Sloan
  Digital Sky Survey

abstract:
  We present a catalog of bulge, disk, and total stellar mass estimates for
~660,000 galaxies in the Legacy area of the Sloan Digital Sky Survey Data
Release 7. These masses are based on a homogeneous catalog of g- and r-band
photometry described by Simard et al. (2011), which we extend here with
bulge+disk and Sersic profile photometric decompositions in the SDSS u, i, and
z bands. We discuss the methodology used to derive stellar masses from these
data via fitting to broadband spectral energy distributions (SEDs), and show
that the typical statistical uncertainty on total, bulge, and disk stellar mass
is ~0.15 dex. Despite relatively small formal uncertainties, we argue that SED
modeling assumptions, including the choice of synthesis model, extinction law,
initial mass function, and details of stellar evolution likely contribute an
additional 60% systematic uncertainty in any mass estimate based on broadband
SED fitting. We discuss several approaches for identifying genuine bulge+disk
systems based on both their statistical likelihood and an analysis of their
one-dimensional surface-brightness profiles, and include these metrics in the
catalogs. Estimates of the total, bulge and disk stellar masses for both normal
and dust-free models and their uncertainties are made publicly available here.


title:
Non-Relativistic Parity-Violating Hydrodynamics in Two Spatial
  Dimensions

abstract:
  We construct the non-relativistic parity-violating hydrodynamic description
of a two-dimensional dissipative, normal fluid in presence of small U(1)
background fields and vorticity. This is achieved by taking the
non-relativistic limit of the recently developed relativistic hydrodynamics in
2+1 dimensions. We identify and interpret the resulting parity-violating
contributions to the non-relativistic constitutive relations, which include the
Hall current flowing perpendicular to the temperature gradient, the Hall
viscosity and the Leduc-Righi energy current. Also a comparison of our findings
is made with the non-relativistic parity-violating hydrodynamics obtained from
a light-cone dimensional reduction.


title:
Estimation of phase diffusion rates in a condensate interferometer using
  the Gross-Pitaevskii Equation

abstract:
  Atom interferometers using Bose-Einstein condensates are fundamentally
limited by a phase diffusion process that arises from atomic interactions. The
Gross-Pitaevskii equation is here used to accurately calculate the diffusion
rate for a Bragg interferometer. It is seen to agree with a Thomas-Fermi
approximation at large atom numbers and a perturbative approximation at low
atom numbers. The diffusion times obtained are generally longer than the
coherence times observed in experiments to date.


title:
Regularity criteria in weak $L^3$ for 3D incompressible Navier-Stokes
  equations

abstract:
  We study the regularity of a distributional solution $(u,p)$ of the 3D
incompressible evolution Navier-Stokes equations. Let $B_r$ denote concentric
balls in $\mathbb{R}^3$ with radius $r$. We will show that if $p\in L^{m} (0,1;
L^1(B_2))$, $m>2$, and if $u$ is sufficiently small in $L^{\infty} (0,1;
L^{3,\infty}(B_2))$, without any assumption on its gradient, then $u$ is
bounded in $B_1\times (\frac{1}{10},1)$. It is an endpoint case of the usual
Serrin-type regularity criteria, and extends the steady-state result of
Kim-Kozono to the time dependent setting. In the appendix we also show some
nonendpoint borderline regularity criteria.


title:
SuperYang-Mills, Chern-Simons couplings and their all order $\alpha'$
  corrections in IIB superstring theory

abstract:
  We explore the closed form of the correlation function of four spin operators
(including one closed string Ramond-Ramond (RR) and two open string fermions)
and one current in ten dimensions, to be able to find the complete and the
closed form of the amplitude of one closed string Ramond-Ramond, one gauge
field and two fermionic strings (with the same chirality) to all orders in
$\alpha'$ in IIB superstring theory. In particular we use a special gauge
fixing to the amplitude and apply fermions' equations of motion to $<V_{C}
V_{A}V_{\bar\psi}V_{\psi} >$ correlator. String amplitude induced that neither
there should be any $u-$channel gauge poles for $p=n+2$ case nor there are
couplings between two fermions and two gauge fields for $p=n$ case in the field
theory of type IIB. All infinite $u-$ channel scalar poles and $t,s-$channel
fermion poles of the string amplitude are useful in discovering new couplings
of type IIB. More specifically, by making use of the SYM couplings of one
scalar, one gauge and two fermions and their all order $\alpha'$ higher
derivative corrections, we are able to exactly produce all infinite $(s+t+u)-$
channel scalar poles of $<V_{C} V_{A}V_{\bar\psi}V_{\psi} >$ .


title: Poincar\'e gauge theory in 3D: canonical stability of the scalar sector

abstract:
  We outline the results of the canonical analysis of the three-dimensional
Poincar\'e gauge theory, defined by the general parity-invariant Lagrangian
with eight free parameters [11]. In the scalar sector, containing scalar or
pseudoscalar (A)dS modes, the stability of the canonical structure under
linearization is used to identify dynamically acceptable values of the
parameters.


title:
Separation Between d$_{5/2}$ and s$_{1/2}$ Neutron Single Particle
  Strength in $^{15}$N

abstract:
  The separation between single particle levels in nuclei plays the dominant
role in determining the location of the neutron drip line. The separation also
provides a test of current crossed shell model interactions if the experimental
data is such that multiple shells are involved. The present work uses the
$^{14}$N(d, p)$^{15}$N reaction to extract the 2s$_{1/2}$, and 1d$_{5/2}$ total
neutron single particle strengths and then compares these results with a shell
model calculation using a p-sd crossed shell interaction to identify the
J$^\pi$ of all levels in $^{15}$N up to 12.8 MeV in excitation.


title: Practical method to obtain a lower bound to the three-tangle

abstract:
  The quantitative assessment of the entanglement in multipartite quantum
states is, apart from its fundamental importance, a practical problem. Recently
there has been significant progress in developing new methods to determine
certain entanglement measures. In particular, there is a method---in principle,
analytical---to compute a certified lower bound for the three-tangle. The
purpose of this work is to provide a manual for the implementation of this
approach and to explicitly discuss several analytically solvable cases in order
to gauge the numerical tools. Moreover, we derive a simple analytical bound for
the mixed state three-tangle.


title: Introduction to Black Hole Evaporation

abstract:
  These lecture notes are an elementary and pedagogical introduction to the
black hole evaporation, based on a lecture given by the author at the Ninth
Modave Summer School in Mathematical Physics and are intended for PhD students.
First, quantum field theory in curved spacetime is studied and tools needed for
the remaining of the course are introduced. Then, quantum field theory in
Rindler spacetime in 1+1 dimensions and in the spacetime of a spherically
collapsing star are considered, leading to Unruh and Hawking effects,
respectively. Finally, some consequences such as thermodynamics of black holes
and information loss paradox are discussed.


title:
b-coloring is NP-hard on co-bipartite graphs and polytime solvable on
  tree-cographs

abstract:
  A b-coloring of a graph is a proper coloring such that every color class
contains a vertex that is adjacent to all other color classes. The b-chromatic
number of a graph G, denoted by \chi_b(G), is the maximum number t such that G
admits a b-coloring with t colors. A graph G is called b-continuous if it
admits a b-coloring with t colors, for every t = \chi(G),\ldots,\chi_b(G), and
b-monotonic if \chi_b(H_1) \geq \chi_b(H_2) for every induced subgraph H_1 of
G, and every induced subgraph H_2 of H_1.
  We investigate the b-chromatic number of graphs with stability number two.
These are exactly the complements of triangle-free graphs, thus including all
complements of bipartite graphs. The main results of this work are the
following:
  - We characterize the b-colorings of a graph with stability number two in
terms of matchings with no augmenting paths of length one or three. We derive
that graphs with stability number two are b-continuous and b-monotonic.
  - We prove that it is NP-complete to decide whether the b-chromatic number of
co-bipartite graph is at most a given threshold.
  - We describe a polynomial time dynamic programming algorithm to compute the
b-chromatic number of co-trees.
  - Extending several previous results, we show that there is a polynomial time
dynamic programming algorithm for computing the b-chromatic number of
tree-cographs. Moreover, we show that tree-cographs are b-continuous and
b-monotonic.


title: Skewon no-go theorem

abstract:
  Axion modification of the electrodynamics can be considered as produced by an
irreducible part of the constitutive pseudotensor. In this paper, we study the
modification of wave propagation produced by the second irreducible part called
skewon. We introduce the notions of skewon optic tensor and skewon optic
covector. With these devices we prove that in a pseudo-Riemannian manifold
endowed with an arbitrary skewon at least one solution of the dispersion
relation is spacelike. This means that the skewon generates superluminal wave
motion and is thus ruled out on the basis of SR principles.


title: Hindered magnetic order from mixed dimensionalities in CuP$_2$O$_6$

abstract:
  We present a combined experimental and theoretical study of the spin-1/2
compound CuP$_2$O$_6$ that features a network of two-dimensional (2D)
antiferromagnetic (AFM) square planes, interconnected via one-dimensional (1D)
AFM spin chains. Magnetic susceptibility, high-field magnetization, and
electron spin resonance (ESR) data, as well as microscopic density-functional
band-structure calculations and subsequent quantum Monte-Carlo simulations,
show that the coupling $J_{2D}\sim$ 40 K in the layers is an order of magnitude
larger than $J_{1D}\sim$ 4 K in the chains. Below $T_N\sim$ 8 K, CuP$_2$O$_6$
develops long-range order (LRO), as evidenced by a weak net moment on the 2D
planes induced by anisotropic magnetic interactions of Dzyaloshinsky-Moriya
type. A striking feature of this 3D ordering transition is that the 1D moments
grow significantly slower than the ones on the 2D layers, which is evidenced by
the persistent paramagnetic ESR signal below $T_N$. Compared to typical
quasi-2D magnets, the ordering temperature of CuP$_2$O$_6$ $T_N/J_{2D}\sim$ 0.2
is unusually low, showing that weakly coupled spins sandwiched between 2D
magnetic units effectively decouple these units and impede the long-range
ordering.


title: Effects of the ISM on Detection of Low-frequency Gravitational Waves

abstract:
  Time variable delays due to radio wave propagation in the ionized
interstellar medium are a substantial source of error in pulsar timing array
efforts. We describe the physical origin of these effects, discussing
dispersive and scattering effects separately. Where possible, we give estimates
of the magnitude of timing errors produced by these effects and their scaling
with radio frequency. Although there is general understanding of the
interstellar medium propagation errors to be expected with pulsar timing array
observations, detailed comparison between theory and practice is still in its
infancy, particularly with regard to scattering effects.


title: Power of Nondetreministic JAGs on Cayley graphs

abstract:
  The Immerman-Szelepcsenyi Theorem uses an algorithm for co-st- connectivity
based on inductive counting to prove that NLOGSPACE is closed un- der
complementation. We want to investigate whether counting is necessary for this
theorem to hold. Concretely, we show that Nondeterministic Jumping Graph
Autmata (ND-JAGs) (pebble automata on graphs), on several families of Cayley
graphs, are equal in power to nondeterministic logspace Turing machines that
are given such graphs as a linear encoding. In particular, it follows that
ND-JAGs can solve co-st-connectivity on those graphs. This came as a surprise
since Cook and Rackoff showed that deterministic JAGs cannot solve
st-connectivity on many Cayley graphs due to their high self-similarity (every
neighbourhood looks the same). Thus, our results show that on these graphs,
nondeterminism provably adds computational power. The families of Cayley graphs
we consider include Cayley graphs of abelian groups and of all finite simple
groups irrespective of how they are presented and graphs corresponding to
groups generated by various product constructions, in- cluding iterated ones.
We remark that assessing the precise power of nondeterministic JAGs and in par-
ticular whether they can solve co-st-connectivity on arbitrary graphs is left
as an open problem by Edmonds, Poon and Achlioptas. Our results suggest a
positive answer to this question and in particular considerably limit the
search space for a potential counterexample.


title:
Linear instability of relative equilibria for $n$-body problems in the
  plane

abstract:
  Following Smale, we study simple symmetric mechanical systems of $n$ point
particles in the plane. In particular, we address the question of the linear
and spectral stability properties of relative equilibria, which are special
solutions of the equations of motion. Our main result is a sufficient condition
to detect spectral (hence linear) instability. Namely, we prove that if the
Morse index of an equilibrium point with even nullity is odd, then the
associated relative equilibrium is spectrally unstable. The proof is based on
some refined formul\ae\ for computing the spectral flow. As a notable
application of our theorem, we examine two important classes of singular
potentials: the $\alpha$-homogeneous one, with $\alpha \in (0, 2)$, which
includes the gravitational case, and the logarithmic one. We also establish,
for the $\alpha$-homogeneous potential, an inequality which is useful to test
the spectral instability of the associated relative equilibrium.


title: Many-flavor Schwinger model at finite chemical potential

abstract:
  We study thermodynamic properties of the Schwinger model on a torus with f
flavors of massless fermions and flavor-dependent chemical potentials.
Generalizing the two-flavor case, we present a representation of the partition
function in the form of a multidimensional theta function and show that the
model exhibits a rich phase structure at zero temperature. The different
phases, characterized by certain values of the particle numbers, are separated
by first-order phase transitions. We work out the phase structure in detail for
three and four fermion flavors and conjecture, based on an exploratory
investigation of the five, six, and eight flavor case, that the maximal number
of coexisting phases at zero temperature grows exponentially with increasing f.


title: Safe and Efficient Screening For Sparse Support Vector Machine

abstract:
  Screening is an effective technique for speeding up the training process of a
sparse learning model by removing the features that are guaranteed to be
inactive the process. In this paper, we present a efficient screening technique
for sparse support vector machine based on variational inequality. The
technique is both efficient and safe.


title:
Duality between preferential attachment and static random networks on
  hyperbolic spaces

abstract:
  There is a complex relation between the mechanism of preferential attachment,
scale-free degree distributions and hyperbolicity in complex networks. In fact,
both preferential attachment and hidden hyperbolic spaces often generate
scale-free networks. We show that there is actually a duality between a class
of growing spatial networks based on preferential attachment on the sphere and
a class of static random networks on the hyperbolic plane. Both classes of
networks have the same scale-free degree distribution as the Barabasi-Albert
model. As a limit of this correspondence, the Barabasi-Albert model is
equivalent to a static random network on an hyperbolic space with infinite
curvature.


title: On a result of Jessica Lin

abstract:
  In Theorem 1.5 of [5] an estimate from below is given for nonnegative
supersolutions of parabolic equations in terms of the measure of the set where
the right-hand side is less than $-1$. The given proof contains many
interesting details which are certainly useful in many other situations.
However, as long as the statement of Theorem 1.5 of \cite{JL} is concerned, it
can be proved in a much shorter way, which we present here.


title: Yetter-Drinfeld modules for Hom-bialgebras

abstract:
  The aim of this paper is to define and study Yetter-Drinfeld modules over
Hom-bialgebras, a generalized version of bialgebras obtained by modifying the
algebra and coalgebra structures by a homomorphism. Yetter-Drinfeld modules
over a Hom-bialgebra with bijective structure map provide solutions of the
Hom-Yang-Baxter equation. The category $_H^H{\mathcal YD}$ of Yetter-Drinfeld
modules with bijective structure maps over a Hom-bialgebra H with bijective
structure map can be organized, in two different ways, as a quasi-braided
pre-tensor category. If H is quasitriangular (respectively coquasitriangular)
the first (respectively second) quasi-braided pre-tensor category
$_H^H{\mathcal YD}$ contains, as a quasi-braided pre-tensor subcategory, the
category of modules (respectively comodules) with bijective structure maps over
H.


title:
Reply to the reply to "Comment on Universal out-of-equilibrium transport
  in Kondo-correlated quantum dots"

abstract:
  I reply to the new arguments of Mu\~noz et al. (arXiv:1308.0638) regarding
our controversy on non-equilibrium Green functions of the impurity Anderson
model, and to new unfounded criticism to my paper Ref. 1 (arXiv:1110.0816). In
particular, I show that the lesser self energy given in Ref. 1 does satisfy a
Ward identity. References are updated.


title:
The Amalgamated Product Structure of the Tame Automorphism Group in
  Dimension Three

abstract:
  It is shown the the tame subgroup $\text{TA}_3(\mathbb C)$ of the group
$\text{GA}_3(\mathbb C)$ of polynomials automorphisms of ${\mathbb C}^3$ can be
realized as the product of three subgroups, amalgamated along pairwise
intersections, in a manner that generalizes the well-known amalgamated free
product structure of $\text{TA}_2(\mathbb C)$ (which coincides with
$\text{GA}_2(\mathbb C)$ by Jung's Theorem). The result follows from defining
relations for $\text{TA}_3(\mathbb C)$ given by U. U. Umirbaev.


title: QCD thermodynamics with O(a) improved Wilson fermions at Nf=2

abstract:
  We present an update of our study of the phase diagram of two-flavour QCD at
zero baryon density with dynamical $O(a)$ improved Wilson quarks. All
simulations are done on lattices with a temporal extent of $N_t=16$ and spatial
extent $L=32,48$ and 64, ensuring that discretisation effects are small and
finite size effects can be controlled. In the approach to the chiral limit we
currently have three scans with pion masses between 540 and 200 MeV. In this
proceedings article the focus is on the new scan at $m_\pi=200$ MeV and the
measurement of screening masses. We also present first results concerning a
test of scaling in the approach to the chiral limit and the chiral
extrapolation of the difference of screening masses in scalar and pseudoscalar
channels, which provides a measure for the strength of the anomalous breaking
of the $U_A(1)$ symmetry.


title: Snowmass CF1 Summary: WIMP Dark Matter Direct Detection

abstract:
  As part of the Snowmass process, the Cosmic Frontier WIMP Direct Detection
subgroup (CF1) has drawn on input from the Cosmic Frontier and the broader
Particle Physics community to produce this document. The charge to CF1 was (a)
to summarize the current status and projected sensitivity of WIMP direct
detection experiments worldwide, (b) motivate WIMP dark matter searches over a
broad parameter space by examining a spectrum of WIMP models, (c) establish a
community consensus on the type of experimental program required to explore
that parameter space, and (d) identify the common infrastructure required to
practically meet those goals.

categories: hep-ex astro-ph.CO astro-ph.HE astro-ph.IM physics.ins-det


title:
Non-Filippov dynamics arising from the smoothing of nonsmooth systems,
  and its robustness to noise

abstract:
  Switch-like behaviour in dynamical systems may be modelled by highly
nonlinear functions, such as Hill functions or sigmoid functions, or
alternatively by piecewise-smooth functions, such as step functions. Consistent
modelling requires that piecewise-smooth and smooth dynamical systems have
similar dynamics, but the conditions for such similarity are not well
understood. Here we show that by smoothing out a piecewise-smooth system one
may obtain dynamics that is inconsistent with the accepted wisdom --- so-called
Filippov dynamics --- at a discontinuity, even in the piecewise-smooth limit.
By subjecting the system to white noise, we show that these discrepancies can
be understood in terms of potential wells that allow solutions to dwell at the
discontinuity for long times. Moreover we show that spurious dynamics will
revert to Filippov dynamics, with a small degree of stochasticity, when the
noise magnitude is sufficiently large compared to the order of smoothing. We
apply the results to a model of a dry-friction oscillator, where spurious
dynamics (inconsistent with Filippov's convention or with Coulomb's model of
friction) can account for different coefficients of static and kinetic
friction, but under sufficient noise the system reverts to dynamics consistent
with Filippov's convention (and with Coulomb-like friction).


title:
An easy-to-use algorithm for simulating traffic flow on networks:
  numerical experiments

abstract:
  In this paper we propose a Godunov-based discretization of a hyperbolic
system of conservation laws with discontinuous flux, modeling vehicular flow on
a network. Each equation describes the density evolution of vehicles having a
common path along the network. We show that the algorithm selects automatically
an admissible solution at junctions, hence ad hoc external procedures (e.g.,
maximization of the flux via a linear programming method) usually employed in
classical approaches are no needed. Since users have not to deal explicitly
with vehicle dynamics at junction, the numerical code can be implemented in
minutes. We perform a detailed numerical comparison with a Godunov-based scheme
coming from the classical theory of traffic flow on networks which maximizes
the flux at junctions.


title: Simple Hardy-like proof of quantum contextuality

abstract:
  Contextuality and nonlocality are two fundamental properties of nature.
Hardy's proof is considered the simplest proof of nonlocality and can also be
seen as a particular violation of the simplest Bell inequality. A fundamental
question is: Which is the simplest proof of contextuality? We show that there
is a Hardy-like proof of contextuality that can also be seen as a particular
violation of the simplest noncontextuality inequality. Interestingly, this new
proof connects this inequality with the proof of the Kochen-Specker theorem,
providing the missing link between these two fundamental results, and can be
extended to an arbitrary odd number $n$ of settings, an extension that can be
seen as a particular violation of the $n$-cycle inequality.


title:
Direct observation of ultrafast long-range charge separation at
  polymer:fullerene heterojunctions

abstract:
  In polymeric semiconductors, charge carriers are polarons, which means that
the excess charge deforms the molecular structure of the polymer chain that
hosts it. This effect results in distinctive signatures in the vibrational
modes of the polymer. We probe polaron photo- generation dynamics at
polymer:fullerene heterojunctions by monitoring its time-resolved
resonance-Raman spectrum following ultrafast photoexcitation. We conclude that
polarons emerge within 200 fs, which is nearly two orders of magnitude faster
than exciton localisation in the neat polymer film. Surprisingly, further
vibrational evolution on <50-ps timescales is modest, indicating that the
polymer conformation hosting nascent polarons is not signif- icantly different
from that in equilibrium. This suggests that charges are free from their mutual
Coulomb potential, under which vibrational dynamics would report charge-pair
relaxation. Our work addresses current debates on the photocarrier generation
mechanism at organic semiconductor heterojunctions, and is, to our knowledge,
the first direct probe of molecular conformation dynamics during this
fundamentally important process in these materials.


title:
Particle entanglement in continuum many-body systems via quantum Monte
  Carlo

abstract:
  Entanglement of spatial bipartitions, used to explore lattice models in
condensed matter physics, may be insufficient to fully describe itinerant
quantum many-body systems in the continuum. We introduce a procedure to measure
the R\'enyi entanglement entropies on a particle bipartition, with general
applicability to continuum Hamiltonians via path integral Monte Carlo methods.
Via direct simulations of interacting bosons in one spatial dimension, we
confirm a logarithmic scaling of the single-particle entanglement entropy with
the number of particles in the system. The coefficient of this logarithmic
scaling increases with interaction strength, saturating to unity in the
strongly interacting limit. Additionally, we show that the single-particle
entanglement entropy is bounded by the condensate fraction, suggesting a
practical route towards its measurement in future experiments.


title:
Sub-Micron Positioning of Trapped Ions with Respect to the Absolute
  Center of a Standing Wave Cavity Field

abstract:
  We demonstrate that it is possible, with sub-micron precision, to locate the
absolute center of a Fabry-P\'erot resonator oriented along the rf-field-free
axis of a linear Paul trap through the application of two simultaneously
resonating optical fields. In particular, we apply a probe field, which is
near-resonant with an electronic transition of trapped ions, simultaneously
with an off-resonant strong field acting as a periodic AC Stark-shifting
potential. Through the resulting spatially modulated fluorescence signal we can
find the cavity center of an 11.7 mm-long symmetric Fabry- P\'erot cavity with
a precision of $\pm$135 nm, which is smaller than the periodicity of the
individual standing wave fields. This can e.g. be used to position the minimum
of the axial trap potential with respect to the center of the cavity at any
location along the cavity mode.


title:
Separable Representation of Phenomenological Optical Potentials of
  Woods-Saxon Type

abstract:
  Background: One important ingredient for many applications of nuclear physics
to astrophysics, nuclear energy, and stockpile stewardship are cross sections
for reactions of neutrons with rare isotopes. Since direct measurements are
often not feasible, indirect methods, e.g. (d,p) reactions, should be used.}
Those (d,p) reactions may be viewed as three-body reactions and described with
Faddeev techniques.
  Purpose: Faddeev equations in momentum space have a long tradition of
utilizing separable interactions in order to arrive at sets of coupled integral
equations in one variable. While there exist several separable representations
for the nucleon-nucleon interaction, the optical potential between a neutron
(proton) and a nucleus is not readily available in separable form. The purpose
of this paper is to introduce a separable representation for complex
phenomenological optical potentials of Woods-Saxon type.
  Results: Starting from a global optical potential, a separable representation
thereof is introduced based on the Ernst-Shakin-Thaler (EST) scheme. This
scheme is generalized to non-hermitian potentials. Applications to n$+^{48}$Ca,
n$+^{132}$Sn and n$+^{208}$Pb are investigated for energies from 0 to 50 MeV
and the quality of the representation is examined.
  Conclusions: We find a good description of the on-shell t-matrix for all
systems with rank up to 5. The required rank depends inversely on the angular
momentum. The resulting separable interaction exhibits a different off-shell
behavior compared to the original potential, reducing the high momentum
contributions.


title:
Lattice study of the Boer-Mulders transverse momentum distribution in
  the pion

abstract:
  The Boer-Mulders transverse momentum-dependent parton distribution (TMD)
characterizes polarized quark transverse momentum in an unpolarized hadron.
Techniques previously developed for lattice calculations of nucleon TMDs are
applied to the pion. These techniques are based on the evaluation of matrix
elements of quark bilocal operators containing a staple-shaped Wilson
connection. Results for the Boer-Mulders transverse momentum shift in the pion,
obtained at a pion mass of $m_{\pi} = 518\, \mbox{MeV} $, are presented and
compared to corresponding results in the nucleon.


title:
Extraction of 3D field maps of magnetic multipoles from 2D surface
  measurements with applications to the optics calculations of the
  large-acceptance superconducting fragment separator BigRIPS

abstract:
  The fringing fields of magnets with large apertures and short lengths greatly
affect ion-optical calculations. In particular, for a high magnetic field where
the iron core becomes saturated, the effective lengths and shapes of the field
distribution must be considered because they change with the excitation
current. Precise measurement of the three-dimensional magnetic fields and the
correct application of parameters in the ion-optical calculations are
necessary. First we present a practical numerical method of extracting full 3D
magnetic field maps of magnetic multipoles from 2D field measurements of the
surface of a cylinder. Using this novel method we extracted the distributions
along the beam axis for the coefficient of the first-order quadrupole
component, which is the leading term of the quadrupole components in the
multipole expansion of magnetic fields and proportional to the distance from
the axis. Higher order components of the 3D magnetic field can be extracted
from the leading term via recursion relations. The measurements were done for
many excitation current values for the large-aperture superconducting triplet
quadrupole magnets (STQs) in the BigRIPS fragment separator at the RIKEN
Nishina Center RI Beam Factory. These distributions were parameterized using
the Enge functions to fit the fringe field shapes at all excitation current
values, so that unmeasured values are interpolated. The extracted distributions
depend only on the position along the beam axis, and thus the measured
three-dimensional field can easily be parameterized for ion-optical
calculations. We implemented these parameters in the ion-optical calculation
code COSY INFINITY and realized a first-order calculation that incorporates the
effect of large and varying fringe fields more accurately. We applied the
calculation to determine the excitation current settings of the STQs...


title:
Exotic open-flavor $bc\bar{q}\bar{q}$, $bc\bar{s}\bar{s}$ and
  $qc\bar{q}\bar{b}$, $sc\bar{s}\bar{b}$ tetraquark states

abstract:
  We study the exotic $bc\bar{q}\bar{q}$, $bc\bar{s}\bar{s}$ and
$qc\bar{q}\bar{b}$, $sc\bar{s}\bar{b}$ systems by constructing the
corresponding tetraquark currents with $J^P=0^+$ and $1^+$. After investigating
the two-point correlation functions and the spectral densities, we perform QCD
sum rule analysis and extract the masses of these open-flavor tetraquark
states. Our results indicate that the masses of both the scalar and axial
vector tetraquark states are about $7.1-7.2$ GeV for the $bc\bar{q}\bar{q}$
system and $7.2-7.3$ GeV for the $bc\bar{s}\bar{s}$ system. For the
$qc\bar{q}\bar{b}$ tetraquark states with $J^P=0^+$ and $1^+$, their masses are
extracted to be around $7.1$ GeV. The masses for the scalar and axial vector
$sc\bar{s}\bar{b}$ states are $7.1$ GeV and $6.9-7.1$ GeV, respectively. The
tetraquark states $qc\bar{q}\bar{b}$ and $sc\bar{s}\bar{b}$ lie below the
thresholds of $D^{(\ast)}B^{(\ast)}$ and $D_s^{(\ast)}B_s^{(\ast)}$
respectively, but they can decay into $B_c$ plus a light meson. However, the
tetraquark states $bc\bar{q}\bar{q}$ and $bc\bar{s}\bar{s}$ lie below the
$D^{(\ast)}\bar B^{(\ast)}$ and $D_s^{(\ast)}\bar B_s^{(\ast)}$ thresholds,
suggesting dominantly weak decay mechanisms.


title: Complex box bounds for real maps

abstract:
  In this paper we prove complex bounds, also referred to as a priori bounds,
for real analytic (and even C3) interval maps. This means that we associate to
such a map a complex box mapping (which provides a kind of Markov structure),
together with universal geometric bounds on the shape of the domains. Such
bounds show that the first return maps to these domains are well-controlled,
and consequently form one of the corner stones in many recent results on
one-dimensional dynamics: renormalisation theory, rigidity results, density of
hyperbolicity, local connectivity.


title: Smoothed and Iterated Bootstrap Confidence Regions for Parameter Vectors

abstract:
  The construction of confidence regions for parameter vectors is a difficult
problem in the nonparametric setting, particularly when the sample size is not
large. The bootstrap has shown promise in solving this problem, but empirical
evidence often indicates that some bootstrap methods have difficulty in
maintaining the correct coverage probability, while other methods may be
unstable, often resulting in very large confidence regions. One way to improve
the performance of a bootstrap confidence region is to restrict the shape of
the region in such a way that the error term of an expansion is as small an
order as possible. To some extent, this can be achieved by using the bootstrap
to construct an ellipsoidal confidence region. This paper studies the effect of
using the smoothed and iterated bootstrap methods to construct an ellipsoidal
confidence region for a parameter vector. The smoothed estimate is based on a
multivariate kernel density estimator. This paper establishes a bandwidth
matrix for the smoothed bootstrap procedure that reduces the asymptotic
coverage error of the bootstrap percentile method ellipsoidal confidence
region. We also provide an analytical adjustment to the nominal level to reduce
the computational cost of the iterated bootstrap method. Simulations
demonstrate that the methods can be successfully applied in practice.


title: A note on singularity of fibers of singular sets

abstract: A general theorem on fibers of singular sets is presented.


title: Unexpected links reflect the noise in networks

abstract:
  Gene covariation networks are commonly used to study biological processes.
The inference of gene covariation networks from observational data can be
challenging, especially considering the large number of players involved and
the small number of biological replicates available for analysis. We propose a
new statistical method for estimating the number of erroneous edges in
reconstructed networks that strongly enhances commonly used inference
approaches. This method is based on a special relationship between sign of
correlation (positive/negative) and directionality (up/down) of gene
regulation, and allows for the identification and removal of approximately half
of all erroneous edges. Using the mathematical model of Bayesian networks and
positive correlation inequalities we establish a mathematical foundation for
our method. Analyzing existing biological datasets, we find a strong
correlation between the results of our method and false discovery rate (FDR).
Furthermore, simulation analysis demonstrates that our method provides a more
accurate estimate of network error than FDR.


title:
On the Optimum Energy Efficiency for Flat-fading Channels with
  Rate-dependent Circuit Power

abstract:
  This paper investigates the optimum energy efficiency (EE) and the
corresponding spectral efficiency (SE) for a communication link operating over
a flat-fading channel. The EE is evaluated by the total energy consumption for
transmitting per message bit. Three channel cases are considered, namely static
channel with channel state information available at transmitter (CSIT),
fast-varying (FV) channel with channel distribution information available at
transmitter (CDIT), and FV channel with CSIT. A general circuit power model is
considered. For all the three channel cases, the tradeoff between the EE and SE
is studied. It is shown that the EE improves strictly as the SE increases from
0 to the optimum SE, and then strictly degrades as the SE increases beyond the
optimum SE. The impact of {\kappa}, {\rho} and other system parameters on the
optimum EE and corresponding SE is investigated to obtain insight.Some of the
important and interesting results for all the channel cases include: (1) when
{\kappa} increases the SE corresponding to the optimum EE should keep unchanged
if {\phi}(R) = R, but reduced if {\phi}(R) is strictly convex of R; (2) when
the rate-independent circuit power {\rho} increases, the SE corresponding to
the optimum EE has to be increased. A polynomial-complexity algorithm is
developed with the bisection method to find the optimum SE. The insight is
corroborated and the optimum EE for the three cases are compared by simulation
results.


title:
Matter-wave interference with particles selected from a molecular
  library with masses exceeding 10000 amu

abstract:
  The quantum superposition principle, a key distinction between quantum
physics and classical mechanics, is often perceived as a philosophical
challenge to our concepts of reality, locality or space-time since it contrasts
our intuitive expectations with experimental observations on isolated quantum
systems. While we are used to associating the notion of localization with
massive bodies, quantum physics teaches us that every individual object is
associated with a wave function that may eventually delocalize by far more than
the body's own extension. Numerous experiments have verified this concept at
the microscopic scale but intuition wavers when it comes to delocalization
experiments with complex objects. While quantum science is the uncontested
ideal of a physics theory, one may ask if the superposition principle can
persist on all complexity scales. This motivates matter-wave diffraction and
interference studies with large compounds in a three-grating interferometer
configuration which also necessitates the preparation of high-mass nanoparticle
beams at low velocities. Here we demonstrate how synthetic chemistry allows us
to prepare libraries of fluorous porphyrins which can be tailored to exhibit
high mass, good thermal stability and relatively low polarizability, which
allows us to form slow thermal beams of these high-mass compounds, which can be
detected in electron ionization mass spectrometry. We present successful
superposition experiments with selected species from these molecular libraries
in a quantum interferometer, which utilizes the diffraction of matter waves at
an optical phase grating. We observe high-contrast quantum fringe patterns with
molecules exceeding a mass of 10 000 amu and 810 atoms in a single particle.


title:
Absolutely calibrated radio polarimetry of the inner Galaxy at 2.3 GHz
  and 4.8 GHz

abstract:
  We present high sensitivity and absolutely calibrated images of diffuse radio
polarisation at a resolution of about 10 arcmin covering the range 10 degr
<l<34 degr and |b|<5 degr at 2.3 GHz from the S-band Parkes All Sky Survey and
at 4.8 GHz from the Sino-German 6 cm polarisation survey of the Galactic plane.
Strong depolarisation near the Galactic plane is seen at 2.3 GHz, which
correlates with strong Halpha emission. We ascribe the depolarisation to
spatial Faraday rotation measure fluctuations of about 65 rad/m2 on scales
smaller than 6-9 pc. We argue that most (about 90%) of the polarised emission
seen at 4.8 GHz originates from a distance of 3-4 kpc in the Scutum arm and
that the random magnetic field dominates the regular field there. A branch
extending from the North Polar Spur towards lower latitudes can be identified
from the polarisation image at 4.8 GHz but only partly from the polarised image
at 2.3 GHz, implying the branch is at a distance larger than 2-3 kpc. We show
that comparison of structure functions of complex polarised intensity with
those of polarised intensity can indicate whether the observed polarised
structures are intrinsic or caused by Faraday screens. The probability
distribution function of gradients from the polarisation images at 2.3 GHz
indicates the turbulence in the warm ionised medium is transonic.


title: Entanglement entropy on the fuzzy sphere

abstract:
  We obtain entanglement entropy on the noncommutative (fuzzy) two-sphere. To
define a subregion with a well defined boundary in this geometry, we use the
symbol map between elements of the noncommutative algebra and functions on the
sphere. We find that entanglement entropy is not proportional to the length of
the region's boundary. Rather, in agreement with holographic predictions, it is
extensive for regions whose area is a small (but fixed) fraction of the total
area of the sphere. This is true even in the limit of small noncommutativity.
We also find that entanglement entropy grows linearly with N, where N is the
size of the irreducible representation of SU(2) used to define the fuzzy
sphere.


title:
Orbital control of effective dimensionality: from spin-orbital
  fractionalization to confinement in the anisotropic ladder system CaCu2O3

abstract:
  Fractionalization of an electronic quasiparticle into spin, charge and
orbital parts is a fundamental and characteristic property of interacting
electrons in one dimension. However, real materials are never strictly
one-dimensional and the fractionalization phenomena are hard to observe. Here
we studied the spin and orbital excitations of the anisotropic ladder material
CaCu2O3, whose electronic structure is not one-dimensional. Combining
high-resolution resonant inelastic x-ray scattering experiments with
theoretical model calculations we show that: (i) spin-orbital fractionalization
occurs in CaCu2O3 along the leg direction x through the xz orbital channel as
in a 1D system; and (ii) no fractionalization is observed for the xy orbital,
which extends in both leg and rung direction, contrary to a 1D system. We
conclude that the directional character of the orbital hopping can select
different degrees of dimensionality. Using additional model calculations, we
show that spin-orbital separation is generally far more robust than the
spin-charge separation. This is not only due to the already mentioned selection
realized by the orbital hopping, but also due to the fact that spinons are
faster than the orbitons.


title: Quantum Imaging of High-Dimensional Hilbert Spaces with Radon Transform

abstract:
  High-dimensional Hilbert spaces possess large information encoding and
transmission capabilities. Characterizing exactly the real potential of
high-dimensional entangled systems is a cornerstone of tomography and quantum
imaging. The accuracy of the measurement apparatus and devices used in quantum
imaging is physically limited, which allows no further improvements to be made.
To extend the possibilities, we introduce a post-processing method for quantum
imaging that is based on the Radon transform and the projection-slice theorem.
The proposed solution leads to an enhanced precision and a deeper
parameterization of the information conveying capabilities of high-dimensional
Hilbert spaces. We demonstrate the method for the analysis of high-dimensional
position-momentum photonic entanglement. We show that the entropic separability
bound in terms of standard deviations is violated considerably more strongly in
comparison to the standard setting and current data processing. The results
indicate that the possibilities of the quantum imaging of high-dimensional
Hilbert spaces can be extended by applying appropriate calculations in the
post-processing phase.


title:
Lifshitz and Schrodinger Vacua, Superstar Resolution in Gauged Maximal
  Supergravities

abstract:
  We consider the subset of gauged maximal supergravities that consists of the
SO(n+1) gauge fields A^{ij} and the scalar deformation T^{ij} of the S^n in the
spherical reduction of M-theory or type IIB. We focus on the Abelian Cartan
subgroup and the diagonal entries of T^{ij}. The resulting theories can be
viewed as the STU models with additional hyperscalars. We find that the
theories with only one or two such vectors can be generalized naturally to
arbitrary dimensions. The same is true for the D=4 or 5 Einstein-Maxwell theory
with such a hyperscalar. The gauge fields become massive, determined by
stationary points of the hyperscalars a la the analogous Abelian Higgs
mechanism. We obtain classes of Lifshitz and Schrodinger vacua in these
theories. The scaling exponent z turns out to be rather restricted, taking
fractional or irrational numbers. Tweaking the theories by relaxing the mass
parameter or making a small change of the superpotential, we find that
solutions with z=2 can emerge. In a different application, we find that the
resolution of superstar singularity in the STU models by using bubbling-AdS
solitons can be generalized to arbitrary dimensions in our theories. In
particular, we obtain the smooth AdS solitons that can be viewed as the
resolution of the Reissner-Nordstrom superstars in general dimensions.


title: Thermal machines beyond the weak coupling regime

abstract:
  How much work can be extracted from a heat bath using a thermal machine? The
study of this question has a very long tradition in statistical physics in the
weak-coupling limit, applied to macroscopic systems. However, the assumption
that thermal heat baths remain uncorrelated with physical systems at hand is
less reasonable on the nano-scale and in the quantum setting. In this work, we
establish a framework of work extraction in the presence of quantum
correlations. We show in a mathematically rigorous and quantitative fashion
that quantum correlations and entanglement emerge as a limitation to work
extraction compared to what would be allowed by the second law of
thermodynamics. At the heart of the approach are operations that capture
naturally non-equilibrium dynamics encountered when putting physical systems
into contact with each other. We discuss various limits that relate to known
results and put our work into context of approaches to finite-time quantum
thermodynamics.


title: Billiards on Graphs

abstract:
  We prove some partial results on the periodicity of billiard systems on
graphs. The results specialize to the case of $n$ billiards with equal mass on
the unit interval or circle traveling at the same speed.


title:
Identification and Separation of Radioactive Isotope Beams by the
  BigRIPS Separator at the RIKEN RI Beam Factory

abstract:
  We have developed a method for achieving excellent resolving power in
in-flight particle identification of radioactive isotope (RI) beams at the
BigRIPS fragment separator at the RIKEN Nishina Center RI Beam Factory (RIBF).
In the BigRIPS separator, RI beams are identified by their atomic number Z and
mass-to-charge ratio A/Q which are deduced from the measurements of time of
flight (TOF), magnetic rigidity (Brho) and energy loss (delta-E), and delivered
as tagged RI beams to a variety of experiments including secondary reaction
measurements. High A/Q resolution is an essential requirement for this scheme,
because the charge state Q of RI beams has to be identified at RIBF energies
such as 200-300 MeV/nucleon. By precisely determining the Brho and TOF values,
we have achieved relative A/Q resolution as good as 0.034% (root-mean-square
value). The achieved A/Q resolution is high enough to clearly identify the
charge state Q in the Z versus A/Q particle identification plot, where
fully-stripped and hydrogen-like peaks are very closely located. The precise
Brho determination is achieved by refined particle trajectory reconstruction,
while a slew correction is performed to precisely determine the TOF value.
Furthermore background events are thoroughly removed to improve reliability of
the particle identification. In the present paper we present the details of the
particle identification scheme in the BigRIPS separator. The isotope separation
in the BigRIPS separator is also briefly introduced.


title:
Self-quartic interaction for a scalar field in an extended DFR
  noncommutative spacetime

abstract:
  The framework Doplicher-Fredenhagen-Roberts (DFR) of a noncommutative (NC)
space-time is considered as a alternative approach to study the NC space-time
of the early Universe. In this formalism, the parameter of noncommutative
$\theta^{\mu\nu}$ is promoted to a coordinate of the space-time, and
consequently, we are describing a field theory in a space-time with
extra-dimension. Consequently, there is a canonical momentum associated to this
new coordinate in which the effects of a new physics can emerge in the
propagation of the fields along the extra-dimension. The Fourier space of this
framework is automatically extended by the addition of new momenta components.
The main concept that we would like to emphasize from the outset is that the
formalism demonstrated here will not be constructed introducing a NC parameter
in the system, as usual. It will be generated naturally from an already NC
space. When the components of the new momentum are zero, the DFR approach is
reduced to the usual NC case, in which $\theta^{\mu\nu}$ is a antisymmetric
constant matrix. We study a scalar field action with self-quartic interaction
$\phi^{4}\star$ defined in the DFR NC spacetime, obtaining the Feynman rules in
the Fourier space for the scalar propagator and vertex of the model. With these
rules we are able to build out the radiative corrections to one loop order for
the model propagator. The influence of the NC scale, as well as the propagation
of the field in the extra-dimension, are analyzed in the ultraviolet
divergences scenario. We investigate the actual possibility if this
$\theta^{\mu\nu}$ conjugate momentum has the property of healing the mixing
IR/UV divergences that emerges in this recently new NC spacetime quantum field
theory.


title:
Stochastically Symplectic Maps and Their Applications to Navier-Stokes
  Equation

abstract:
  Poincare's invariance principle for Hamiltonian flows implies Kelvin's
principle for solution to Incompressible Euler Equation. Iyer-Constantin
Circulation Theorem offers a stochastic analog of Kelvin's principle for
Navier-Stokes Equation. Weakly symplectic diffusions are defined to produce
stochastically symplectic flows in a systematic way. With the aid of symplectic
diffusions, we produce a family of martigales associated with solutions to
Navier-Stokes Equation that in turn can be used to prove Iyer-Constantin
Circulation Theorem. We also review some basic facts in symplectic and contact
geometry and their applications to Euler Equation.


title: Thermalization of field driven quantum systems

abstract:
  There is much interest in how quantum systems thermalize after a sudden
change, because unitary evolution should preclude thermalization. The
eigenstate thermalization hypothesis resolves this because all observables for
quantum states in a small energy window have essentially the same value; it is
violated for integrable systems due to the infinite number of conserved
quantities. Here, we show that when a system is driven by a DC electric field
there are five generic behaviors: (i) monotonic or (ii) oscillatory approach to
an infinite-temperature steady state; (iii) monotonic or (iv) oscillatory
approach to a nonthermal steady state; or (v) evolution to an oscillatory
state. Examining the Hubbard model (which thermalizes under a quench) and the
Falicov-Kimball model (which does not), we find both exhibit scenarios (i-iv),
while only Hubbard shows scenario (v). This shows richer behavior than in
interaction quenches and integrability in the absence of a field plays no role.


title:
New Evidence for Efficient Collisionless Heating of Electrons at the
  Reverse Shock of a Young Supernova Remnant

abstract:
  Although collisionless shocks are ubiquitous in astrophysics, certain key
aspects of them are not well understood. In particular, the process known as
collisionless electron heating, whereby electrons are rapidly energized at the
shock front, is one of the main open issues in shock physics. Here we present
the first clear evidence for efficient collisionless electron heating at the
reverse shock of Tycho's supernova remnant (SNR), revealed by Fe-K diagnostics
using high-quality X-ray data obtained by the Suzaku satellite. We detect
K-beta (3p->1s) fluorescence emission from low-ionization Fe ejecta excited by
energetic thermal electrons at the reverse shock front, which peaks at a
smaller radius than Fe K-alpha (2p->1s) emission dominated by a relatively
highly-ionized component. Comparison with our hydrodynamical simulations
implies instantaneous electron heating to a temperature 1000 times higher than
expected from Coulomb collisions alone. The unique environment of the reverse
shock, which is propagating with a high Mach number into rarefied ejecta with a
low magnetic field strength, puts strong constraints on the physical mechanism
responsible for this heating, and favors a cross-shock potential created by
charge deflection at the shock front. Our sensitive observation also reveals
that the reverse shock radius of this SNR is about 10% smaller than the
previous measurement using the Fe K-alpha morphology from the Chandra
observations. Since strong Fe K-beta fluorescence is expected only from
low-ionization plasma where Fe ions still have many 3p electrons, this feature
is key to diagnosing the plasma state and distribution of the immediate
postshock ejecta in a young SNR.


title: The Nature of Millisecond Pulsars with Helium White Dwarf Companions

abstract:
  We examine the growing data set of binary millisecond pulsars that are
thought to have a helium white dwarf companion. These systems are believed to
form when a low- to intermediate-mass companion to a neutron star fills its
Roche lobe between central hydrogen exhaustion and core helium ignition. We
confirm that our own stellar models reproduce a well-defined period-companion
mass relation irrespective of the details of the mass transfer process. With
magnetic braking this relation extends to periods of less than 1d for a 1Msun
giant donor. With this and the measured binary mass functions we calculate the
orbital inclination of each system for a given pulsar mass. We expect these
inclinations to be randomly oriented in space. If the masses of the pulsars
were typically 1.35Msun then there would appear to be a distinct dearth of
high-inclination systems. However if the pulsar masses are more typically 1.55
to 1.65Msun then the distribution of inclinations is indeed indistinguishable
from random. If it were as much as 1.75Msun then there would appear to be an
excess of high-inclination systems. Thus with the available data we can argue
that the neutron star masses in binary millisecond pulsars recycled by mass
transfer from a red giant typically lie around 1.6Msun and that there is no
preferred inclination at which these systems are observed. Hence there is
reason to believe that pulsar beams are either sufficiently broad or show no
preferred direction relative to the pulsar's spin axis which is aligned with
the binary orbit. This is contrary to some previous claims, based on a subset
of the data available today, that there might be a tendency for the pulsar
beams to be perpendicular to their spin.


title:
Point-process deconvolution of fMRI reveals effective connectivity
  alterations in chronic pain patients

abstract:
  It is now recognized that important information can be extracted from the
brain spontaneous activity, as exposed by recent analysis using a repertoire of
computational methods. In this context a novel method, based on a blind
deconvolution technique, is used in this paper to analyze potential changes due
to chronic pain in the brain pain matrix's effective connectivity. The approach
is able to deconvolve the hemodynamic response function to spontaneous neural
events, i.e., in the absence of explicit onset timings, and to evaluate
information transfer between two regions as a joint probability of the
occurrence of such spontaneous events. The method revealed that the chronic
pain patients exhibit important changes in the Insula's effective connectivity
which can be relevant to understand the overall impact of chronic pain on brain
function.


title: Love can be Tough to Measure

abstract:
  The waveform phase for a neutron star binary can be split into point-particle
terms and finite-size terms (characterized by the Love number) that account for
equation of state effects. The latter first enter at 5 post-Newtonian (PN)
order (i.e. proportional to the tenth power of the orbital velocity), but the
former are only known completely to 3.5 PN order, with higher order terms only
known to leading-order in the mass-ratio. We here find that not including
point-particle terms at 4PN order to leading- and first-order in the mass ratio
in the template model can severely deteriorate our ability to measure the
equation of state. This problem can be solved if one uses numerical waveforms
once their own systematic errors are under control.


title: Cohomological resolutions for anomalous Lie constraints

abstract:
  It is shown that the BRST resolution of the spaces of physical states of the
systems with anomalies can be consistently defined. The appropriate anomalous
complexes are obtained by canonical restrictions of the ghost extended spaces
to the kernel of anomaly operator without any modifications of the "matter"
sector. The cohomologies of the anomalous complex for the case of constarints
constituting a centrally extended simple Lie algebra of compact type are
calculated and analyzed in details within the framework of Hodge - deRham -
Kaehler theory: the vanishing theorem of the relative cohomologies is proved
and the absolute cohomologies are reconstructed.


title:
A SIS reaction-diffusion-advection model in a low-risk and high-risk
  domain

abstract:
  A simplified SIS reaction-diffusion-advection model is proposed and
investigated to understand the impact of spatial heterogeneity of environment
and advection on the persistence and eradication of an infectious disease. The
free boundary is introduced to model the contact transmission at the spreading
front of the disease. The behavior of positive solutions to a
reaction-diffusion-advection system are discussed. The basic reproduction
number $R_0^F(t)$ associated with the diseases in the spatial setting is
introduced for this diffusive SIS model with the free boundary, we prove that
fast diffusion, small expanding rate and small initial infected domain are
benefit for the control of the spatial spread of the disease. Sufficient
conditions for the disease to be eradicated or to spread are also given, our
result shows that the disease will spread to the whole area if there exists a
$t_0\geq 0$ such that $R_{0}^F(t_0)\geq 1$, that is, if the spreading domain is
high-risk at some time, the disease will continue to spread till the whole area
is infected; while if $R_{0}^F(0)<1$, the disease may be vanishing or keep
spreading depends on the expanding rate and the initial number of the infective
individuals. The spreading speeds are also given when spreading happens, and
numerical simulations are also given to illustrate the impacts of the advection
and the expanding rate on the spreading fronts.


title: Higgs Working Group Report of the Snowmass 2013 Community Planning Study

abstract:
  This report summarizes the work of the Energy Frontier Higgs Boson working
group of the 2013 Community Summer Study (Snowmass). We identify the key
elements of a precision Higgs physics program and document the physics
potential of future experimental facilities as elucidated during the Snowmass
study. We study Higgs couplings to gauge boson and fermion pairs, double Higgs
production for the Higgs self-coupling, its quantum numbers and $CP$-mixing in
Higgs couplings, the Higgs mass and total width, and prospects for direct
searches for additional Higgs bosons in extensions of the Standard Model. Our
report includes projections of measurement capabilities from detailed studies
of the Compact Linear Collider (CLIC), a Gamma-Gamma Collider, the
International Linear Collider (ILC), the Large Hadron Collider High-Luminosity
Upgrade (HL-LHC), Very Large Hadron Colliders up to 100 TeV (VLHC), a Muon
Collider, and a Triple-Large Electron Positron Collider (TLEP).


title: A diagrammatic approach to Kronecker squares

abstract:
  In this paper we apply a method of Robinson and Taulbee for computing
Kronecker coefficients together with other ingredients and show that the
multiplicity of each component in a Kronecker square can be obtained from an
evaluation of a certain polynomial, which depends only on the component and is
computed combinatorially. This polynomial has as many variables as the set of
isomorphism classes of connected skew diagrams of size at most the depth of the
component.
  We present two applications. The first is a contribution to Saxl conjecture,
which asserts that the Kronecker square of the staircase partition, contains
every irreducible character of the symmetric group as a component. We prove
that for any partition there is a piecewise polynomial function in one real
variable such that for all k, such that the multiplicity of this partition in
the Kronecker square of the staircase partition of size k is given by the
evaluation of the polynomial function in k. The second application is a proof
of a new stability property for Kronecker coefficients.


title:
Improving frequency selection of driven pulses using derivative-based
  transition suppression

abstract:
  Many techniques in quantum control rely on frequency separation as a means
for suppressing unwanted couplings. In its simplest form, the mechanism relies
on the low bandwidth of control pulses of long duration. Here we perform a
higher-order quantum-mechanical treatment that allows for higher precision and
shorter times. In particular, we identify three kinds of off-resonant effects:
i) simultaneous unwanted driven couplings (e.g. due to drive crosstalk), ii)
additional (initially undriven) transitions such as those in an infinite ladder
system, and iii) sideband frequencies of the driving waveform such as we find
in corrections to the rotating wave approximation. With a framework that is
applicable to all three cases, in addition to the known adiabatic error
responsible for a shift of the energy levels we typically see in the
spectroscopy of such systems, we derive error terms in a controlled expansion
corresponding to higher order adiabatic effects and diabatic excitations. We
show, by also expanding the driving waveform in a basis of different order
derivatives of a trial function (typically a Gaussian) these different error
terms can be corrected for in a systematic way hence strongly improving quantum
control of systems with dense spectra.


title:
Incentive Mechanisms for Mobile Crowd Sensing: Current States and
  Challenges of Work

abstract:
  Mobile crowd sensing (MCS) is a new paradigm which leverages the ubiquity of
sensor-equipped mobile devices such as smartphones, music players, and
in-vehicle sensors at the edge of the Internet, to collect data. The new
paradigm will fuel the evolution of the Internet of Things to three changes as
follows: First, the terminal devices at the edge of the Internet change from
PCs to mobile phones. Second, the interactive mode extends from the virtual
space to the real physical world. Thirdly, the forwarding manner of sensing
data are undergoing the transition from the priori to the opportunistic. To
better meet the demands of MCS applications at a societal scale, incentive
mechanisms are indispensable. In this paper, we will first overview three
categories of MCS applications, and then propose a new architecture for MCS
applications. Based on the architecture, we discuss various research challenges
about incentive mechanism designs for MCS applications, followed by potential
future work discussions. Finally, we present potential future works.


title: The Pseudospectrum of the Zakharov-Shabat System

abstract:
  We study the pseudospectrum of the non-selfadjoint Zakharov-Shabat system in
the semiclassical regime. The pseudospectrum may be defined as the union of the
spectra of perturbations of the Zakharov-Shabat system, thus it is relevant to
the numerical computation of true eigenvalues.


title: On spontaneous breaking of conformal symmetry by probe flavour D-branes

abstract:
  We explore the possibilities of breaking conformal symmetry spontaneously by
introducing flavour branes into conformal holographic backgrounds in the probe
limit. A prototype model of such a mechanism is based on placing D7 - anti-D7
configuration in the Klebanov-Witten conifold based model. In this paper we
generalize this model. We conjecture on the required topology of the
backgrounds and the corresponding probe brane embeddings. We identify several
models that obey these requirements and admit spontaneous breaking of conformal
invariance. These include type IIB conifold based examples, dual to defect
field theories based on the conifold, and type IIA constructions based on the
ABJM model. We identify the dilaton, the corresponding Goldstone boson, discuss
its effective action and address the "a-term". We briefly discuss the relevance
of these models to the pseudo dilaton.


title:
Electron acceleration in a nonrelativistic shock with very high Alfv\'en
  Mach number

abstract:
  Electron acceleration associated with various plasma kinetic instabilities in
a nonrelativistic, very-high-Alfv\'en Mach-number ($M_A \sim 45$) shock is
revealed by means of a two-dimensional fully kinetic PIC simulation.
Electromagnetic (ion Weibel) and electrostatic (ion-acoustic and Buneman)
instabilities are strongly activated at the same time in different regions of
the two-dimensional shock structure. Relativistic electrons are quickly
produced predominantly by the shock surfing mechanism with the Buneman
instability at the leading edge of the foot. The energy spectrum has a
high-energy tail exceeding the upstream ion kinetic energy accompanying the
main thermal population. This gives a favorable condition for the ion acoustic
instability at the shock front, which in turn results in additional
energization. The large-amplitude ion Weibel instability generates current
sheets in the foot, implying another dissipation mechanism via magnetic
reconnection in a three-dimensional shock structure in the very-high-$M_A$
regime.


title:
A Non-Centrosymmetric Superconductor with a Bulk 3D Dirac Cone Gapped by
  Strong Spin Orbit Coupling

abstract:
  Layered, non-centrosymmetric, heavy element PbTaSe2 is found to be
superconducting. We report its electronic properties accompanied by electronic
structure calculations. Specific heat, electrical resistivity and magnetic
susceptibility measurements indicate that PbTaSe2 is a moderately coupled,
type-II BCS superconductor (Tc = 3.72 K, Ginzburg-Landau parameter Kappa = 14)
with an electronphonon coupling constant of Lambda_ep = 0.74. Electronic
structure calculations reveal a single bulk 3D Dirac cone at the K point of the
Brillouin Zone derived exclusively from its hexagonal Pb layer; it is similar
to the feature found in graphene except there is a 0.8 eV gap opened by
spin-orbit coupling. The combination of large spin-orbit coupling and lack of
inversion symmetry also results in large Rashba splitting on the order of
tenths of eV.


title: On the inverses of some classes of permutations of finite fields

abstract:
  We study the compositional inverses of some general classes of permutation
polynomials over finite fields. We show that we can write these inverses in
terms of the inverses of two other polynomials bijecting subspaces of the
finite field, where one of these is a linearized polynomial. In some cases we
are able to explicitly obtain these inverses, thus obtaining the compositional
inverse of the permutation in question. In addition we show how to compute a
linearized polynomial inducing the inverse map over subspaces on which a
prescribed linearized polynomial induces a bijection. We also obtain the
explicit compositional inverses of two classes of permutation polynomials
generalizing those whose compositional inverses were recently obtained in [22]
and [24], respectively.


title:
Orbital magnetic moment and coercivity of SiO$_{2}$-coated FePt
  nanoparticles studied by x-ray magnetic circular dichroism

abstract:
  We have investigated the spin and orbital magnetic moments of Fe in FePt
nanoparticles in the $L$1$_{0}$-ordered phase coated with SiO$_{2}$ by x-ray
absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD)
measurements at the Fe $L_{\rm 2,3}$ absorption edges. Using XMCD sum rules, we
evaluated the ratio of the orbital magnetic moment ($M_{\rm orb}$) to the spin
magnetic moment ($M_{\rm spin}$) of Fe to be $M_{\rm orb}/M_{\rm spin}$ = 0.08.
This $M_{\rm orb}/M_{\rm spin}$ value is comparable to the value (0.09)
obtained for FePt nanoparticles prepared by gas phase condensation, and is
larger than the values ($\sim$0.05) obtained for FePt thin films, indicating a
high degree of $L$1$_{0}$ order. The hysteretic behavior of the FePt component
of the magnetization was measured by XMCD. The magnetic coercivity ($H_{\rm
c}$) was found to be as large as 1.8 T at room temperature, $\sim$3 times
larger than the thin film value and $\sim$50 times larger than that of the gas
phase condensed nanoparticles. The hysteresis curve is well explained by the
Stoner-Wohlfarth model for non-interacting single-domain nanoparticles with the
$H_{\rm c}$ distributed from 1 T to 5 T.


title: Tensor product weight representations of the Neveu-Schwarz algebra

abstract:
  In this paper, the tensor product of highest weight modules with intermediate
series modules over the Neveu-Schwarz algebra is studied. The weight spaces of
such tensor products are all infinitely dimensional if the highest weight
module is nontrivial. We find that all such tensor products are indecomposable.
We give the necessary and sufficient conditions for these tensor product
modules to be irreducible by using shifting technique established for the
Virasoro case in [13]. The necessary and sufficient conditions for any two such
tensor products to be isomorphic are also determined.


title:
Scaling of entanglement entropy in the (branching) multi-scale
  entanglement renormalization ansatz

abstract:
  We investigate the scaling of entanglement entropy in both the multi-scale
entanglement renormalization ansatz (MERA) and in its generalization, the
branching MERA. We provide analytical upper bounds for this scaling, which take
the general form of a boundary law with various types of multiplicative
corrections, including power-law corrections all the way to a bulk law. For
several cases of interest, we also provide numerical results that indicate that
these upper bounds are saturated to leading order. In particular we establish
that, by a suitable choice of holographic tree, the branching MERA can
reproduce the logarithmic multiplicative correction of the boundary law
observed in Fermi liquids and spin-Bose metals in $D\geq 2$ dimensions.


title:
Lipschitz-Volume rigidity on limit spaces with Ricci curvature bounded
  from below

abstract:
  We prove a Lipschitz-Volume rigidity theorem for the non-collapsed
Gromov-Hausdorff limits of manifolds with Ricci curvature bounded from below.
This is a counterpart of the Lipschitz-Volume rigidity in Alexandrov geometry.


title:
Capacity and Delay-Throughput Tradeoff in ICMNs with Poisson Meeting
  Process

abstract:
  Intermittently connected mobile networks (ICMNs) serve as an important
network model for many critical applications. This paper focuses on a
continuous ICMN model where the pair-wise meeting process between network nodes
follows a homogeneous and independent Poisson process. This ICMN model is known
to serve as good approximations to a class of important ICMNs with mobility
models like random waypoint and random direction, so it is widely adopted in
the performance study of ICMNs. This paper studies the throughput capacity and
delay-throughput tradeoff in the considered ICMNs with Poisson meeting process.
For the concerned ICMN, we first derive an exact expression of its throughput
capacity based on the pairwise meeting rate therein and analyze the expected
end-to-end packet delay under a routing algorithm that can achieve the
throughput capacity. We then explore the inherent tradeoff between delay and
throughput and establish a necessary condition for such tradeoff that holds
under any routing algorithm in the ICMN. To illustrate the applicability of the
theoretical results, case studies are further conducted for the random waypoint
and random direction mobility models. Finally, simulation and numerical results
are provided to verify the efficiency of our theoretical capacity/delay results
and to illustrate our findings.


title:
BCS-like superconductivity in the noncentrosymmetric compounds
  Nb$_x$Re$_{1-x}$

abstract:
  We present research on the superconducting properties of Nb$_{x}$Re$_{1-x}$
($x$ = 0.13-0.38) obtained by measuring the electrical resistivity $\rho(T)$,
magnetic susceptibility $\chi(T)$, specific heat $C_P(T)$, and London
penetration depth $\Delta\lambda(T)$. It is found that the superconducting
transition temperature $T_c$ decreases monotonically with an increase of $x$.
The upper critical field $B_{c2}(T)$ for various $x$ can be nicely scaled by
its corresponding $T_c$. The electronic specific heat $C_e(T)/T$, penetration
depth $\Delta\lambda(T)$, and superfluid density $\rho_{s}(T)$ demonstrate
exponential behavior at low temperatures and can be well fitted by a one-gap
BCS model. The residual Sommerfeld coefficient $\gamma_0(B)$ in the
superconducting state follows a linear field dependence. All these properties
suggest an \emph{s}-wave BCS-type of superconductivity with a very large
$B_{c2}(0)$ for Nb$_{x}$Re$_{1-x}$ (0.13 $\leq x \leq$ 0.38).


title: Can we observationally test the weak cosmic censorship conjecture?

abstract:
  In general relativity, gravitational collapse of matter fields ends with the
formation of a spacetime singularity, where the matter density becomes infinite
and standard physics breaks down. According to the weak cosmic censorship
conjecture, singularities produced in the gravitational collapse cannot be seen
by distant observers and must be hidden within black holes. The validity of
this conjecture is still controversial and at present we cannot exclude that
naked singularities can be created in our Universe from regular initial data.
In this paper, we study the radiation emitted by a collapsing cloud of dust and
check whether it is possible to distinguish the birth of a black hole from the
one of a naked singularity. In our simple dust model, we find that the
properties of the radiation emitted in the two scenarios is qualitatively
similar. That suggests that observational tests of the cosmic censorship
conjecture may be very difficult, even in principle.


title: Event-based Bipartite Consensus on Signed Networks

abstract:
  In this paper, a bipartite consensus problem for a multi-agent system is
formulated firstly. Then an event-based interaction rule is proposed for the
multi-agent system with antagonistic interactions. The bipartite consensus
stability is analyzed on the basis of spectral properties of the signed
Laplacian matrix associated with multi-agent networks. Some simulation results
are presented to illustrate the bipartite consensus with the proposed
interaction rule.


title: Stanley-Wilf limits are typically exponential

abstract:
  For a permutation $\pi$, let $S_{n}(\pi)$ be the number of permutations on
$n$ letters avoiding $\pi$. Marcus and Tardos proved the celebrated
Stanley-Wilf conjecture that $L(\pi)= \lim_{n \to \infty} S_n(\pi)^{1/n}$
exists and is finite. Backed by numerical evidence, it has been conjectured by
many researchers over the years that $L(\pi)=\Theta(k^2)$ for every permutation
$\pi$ on $k$ letters. We disprove this conjecture, showing that
$L(\pi)=2^{k^{\Theta(1)}}$ for almost all permutations $\pi$ on $k$ letters.


title:
Oblique propagation of dust ion-acoustic solitary waves in a magnetized
  dusty pair-ion plasma

abstract:
  We investigate the propagation characteristics of electrostatic waves in a
magnetized pair-ion plasma with immobile charged dusts. It is shown that
obliquely propagating (OP) low-frequency (in comparison with the negative-ion
cyclotron frequency) long-wavelength "slow" and "fast" modes can propagate,
respectively, as dust ion-acoustic (DIA) and dust ion-cyclotron (DIC)-like
waves. The properties of these modes are studied with the effects of
obliqueness of propagation $(\theta)$, the static magnetic field, the ratios of
the negative to positive ion masses $(m)$ and temperatures $(T)$ as well as the
dust to negative-ion number density ratio $(\delta)$. Using the standard
reductive perturbation technique, we derive a Korteweg-de Vries (KdV) equation
which governs the evolution of small-amplitude OP DIA waves. It is found that
the KdV equation admits only rarefactive solitons in plasmas with $m$ well
below its critical value $m_c~(\gg1)$ which typically depends on $T$ and
$\delta$. It is shown that the nonlinear coefficient of the KdV equation
vanishes at $m=m_c$, i.e., for plasmas with much heavier negative ions, and the
evolution of the DIA waves is then described by a modified KdV (mKdV) equation.
The latter is shown to have only compressive soliton solution. The properties
of both the KdV and mKdV solitons are studied with the system parameters as
above, and possible applications of our results to laboratory and space plasmas
are briefly discussed.


title: Interplay of electron correlation and covalency in FeTe(0.6)Se(0.4)

abstract:
  We investigate the electronic structure of FeTe(0.6)Se(0.4) employing high
resolution photoemission spectroscopy and ab initio band structure
calculations. Fe 2p core level and the valence band spectra exhibit signature
of strong electron correlation in the electronic structure. The electronic
states near the Fermi level reduces in intensity with the decrease in
temperature in conformity with the insulating transport observed near 300 K.
The observation of an insulator to metal transition around 150 K in the
transport properties may be related to the spectral lineshape change in the
vicinity of the Fermi level observed in this study. The spectral features near
Fermi level exhibit significant p orbital character due to the correlation
induced Fe d spectral weight transfer. The experimental spectra reveal dominant
temperature dependence of the spectral functions possessing large p-character.
These results demonstrate significant renormalization of the character of the
conduction electrons due to electron correlation and emphasizes the importance
of ligand states in the superconductivity of these materials.


title: A Labeling Approach to Incremental Cycle Detection

abstract:
  In the \emph{incremental cycle detection} problem arcs are added to a
directed acyclic graph and the algorithm has to report if the new arc closes a
cycle. One seeks to minimize the total time to process the entire sequence of
arc insertions, or until a cycle appears.
  In a recent breakthrough, Bender, Fineman, Gilbert and Tarjan
\cite{BeFiGiTa11} presented two different algorithms, with time complexity
$O(n^2 \log n)$ and $O(m \cdot \min \{m^{1/2}, n^{2/3} \})$, respectively.
  In this paper we introduce a new technique for incremental cycle detection
that allows us to obtain both bounds (up to a logarithmic factor). Furthermore,
our approach seems more amiable for distributed implementation.


title: Novel K Rattling: A New Route to Thermoelectric Materials?

abstract:
  We have performed ab initio molecular dynamics (MD) simulations to study the
alkali-metal dynamics in the Al-doped (KAl0.33W1.67O6 and RbAl0.33W1.67O6) and
undoped (KW2O6 and RbW2O6) defect pyrochlore tungstates. The K atoms exhibit
novel rattling dynamics in both the doped and undoped tungstates while the Rb
atoms do not. The KAl0.33W1.67O6 experimental thermal conductivity curve shows
an unusual depression between ~ 50 K and ~ 250 K, coinciding with two
crossovers in the K dynamics: the first at ~ 50 K, from oscillatory to
diffusive, and the second at ~ 250 K, from diffusive back to oscillatory. We
found that the low-temperature crossover is a result of the system
transitioning below the activation energy of the diffusive dynamics whereas the
high-temperature crossover is driven by a complex reconstruction of the local
potential around the K atoms due to the cage dynamics. This leads to a
hardening of the K potential with increasing temperature. This unusual
reconstruction of the potential may have important implications for the
interpretation of finite-temperature dynamics based on zero-temperature
potentials in similar materials. The key result is that the novel K rattling,
involving local diffusion, leads to a significant reduction in the thermal
conductivity. We suggest that this may open a new route in the phonon
engineering of cage compounds for thermoelectric materials where the rattlers
are specifically selected to reduce the lattice thermal conductivity by the
mechanism of local diffusion.


title:
Bioinformatics Knowledge Transmission (training, learning, and
  teaching): overview and flexible comparison of computer based training
  approaches

abstract:
  The merger of computer science, mathematics, and life sciences has brought
about the discipline known as bioinformatics. However, the transmission (e.g.
training, learning, and teaching) of this knowledge becomes an important issue.
Many tools have been developed to help the bioinformatics community with that
transmission challenge. When selecting the best of these tools, called here
BKTMS (Bioinformatics Knowledge Transmission Management Systems), there may be
confusion. What makes a good BKTMS? How can we make this choice efficiently?
These questions remain unanswered for many users (e.g. learner, teacher and
student, trainer and trainee, administrator). This paper provides a critical
review of 32 existing BKTMS and a flexible comparison. This review and
evaluation will be used to gain insight into the tools, systems, and
capabilities that will be added to or excluded from a new proposed model for
the next generation of BKTMS, involving multidisciplinary, web semantic tools
(e.g. web services, workflow) and standards like LOM, or SCORM.


title: Laser damage helps the eavesdropper in quantum cryptography

abstract:
  We propose a class of attacks on quantum key distribution (QKD) systems where
an eavesdropper actively engineers new loopholes by using damaging laser
illumination to permanently change properties of system components. This can
turn a perfect QKD system into a completely insecure system. A
proof-of-principle experiment performed on an avalanche photodiode-based
detector shows that laser damage can be used to create loopholes. After about 1
W illumination, the detectors' dark count rate reduces 2 to 5 times,
permanently improving single-photon counting performance. After about 1.5 W,
the detectors switch permanently into the linear photodetection mode and become
completely insecure for QKD applications.


title:
Local Fourier Analysis of Multigrid Methods with Polynomial Smoothers
  and Aggressive coarsening

abstract:
  We focus on the study of multigrid methods with aggressive coarsening and
polynomial smoothers for the solution of the linear systems corresponding to
finite difference/element discretizations of the Laplace equation. Using local
Fourier analysis we determine automatically the optimal values for the
parameters involved in defining the polynomial smoothers and achieve fast
convergence of cycles with aggressive coarsening. We also present numerical
tests supporting the theoretical results and the heuristic ideas. The methods
we introduce are highly parallelizable and efficient multigrid algorithms on
structured and semi-structured grids in two and three spatial dimensions.