title:
Polynomial-time Solvable #CSP Problems via Algebraic Models and Pfaffian
  Circuits

abstract:
  A Pfaffian circuit is a tensor contraction network where the edges are
labeled with changes of bases in such a way that a very specific set of
combinatorial properties are satisfied. By modeling the permissible changes of
bases as systems of polynomial equations, and then solving via computation, we
are able to identify classes of 0/1 planar #CSP problems solvable in
polynomial-time via the Pfaffian circuit evaluation theorem (a variant of L.
Valiant's Holant Theorem). We present two different models of 0/1 variables,
one that is possible under a homogeneous change of basis, and one that is
possible under a heterogeneous change of basis only. We enumerate a series of
1,2,3, and 4-arity gates/cogates that represent constraints, and define a class
of constraints that is possible under the assumption of a ``bridge" between two
particular changes of bases. We discuss the issue of planarity of Pfaffian
circuits, and demonstrate possible directions in algebraic computation for
designing a Pfaffian tensor contraction network fragment that can simulate a
swap gate/cogate. We conclude by developing the notion of a decomposable
gate/cogate, and discuss the computational benefits of this definition.


title:
High Precision Astrometry in Asteroid Mitigation - the NEOShield
  Perspective

abstract:
  Among the currently known Near Earth Objects (NEOs), roughly 1400 are
classified as being potentially hazardous asteroids. The recent Chelyabinsk
event has shown that these objects can pose a real threat to mankind. We
illustrate that high precision asteroid astrometry plays a vital role in
determining potential impact risks, selecting targets for deflection
demonstration missions and evaluating mitigation mission success. After a brief
introduction to the NEOShield project, an international effort initiated by the
European Commission to investigate aspects of NEO mitigation in a comprehensive
fashion, we discuss current astrometric performances, requirements and possible
issues with NEO risk assessment and deflection demonstration missions.


title: Uncertain growth and the value of the future

abstract:
  For environmental problems such as global warming future costs must be
balanced against present costs. This is traditionally done using an exponential
function with a constant discount rate, which reduces the present value of
future costs. The result is highly sensitive to the choice of discount rate and
has generated a major controversy as to the urgency for immediate action. We
study analytically several standard interest rate models from finance and
compare their properties to empirical data. From historical time series for
nominal interest rates and inflation covering 14 countries over hundreds of
years, we find that extended periods of negative real interest rates are
common, occurring in many epochs in all countries. This leads us to choose the
Ornstein-Uhlenbeck model, in which real short run interest rates fluctuate
stochastically and can become negative, even if they revert to a positive mean
value. We solve the model in closed form and prove that the long-run discount
rate is always less than the mean; indeed it can be zero or even negative,
despite the fact that the mean short term interest rate is positive. We fit the
parameters of the model to the data, and find that nine of the countries have
positive long run discount rates while five have negative long-run discount
rates. Even if one rejects the countries where hyperinflation has occurred, our
results support the low discounting rate used in the Stern report over higher
rates advocated by others.


title: Search for High Energy GRB Neutrino Emission with ANTARES

abstract:
  ANTARES is the largest high-energy neutrino telescope in the Northern
Hemisphere. A search for neutrinos in coincidence with gamma-ray bursts using
ANTARES data from late 2007 to 2011 is presented here. An extended maximum
likelihood ratio search was employed to optimise the discovery potential for a
neutrino signal as predicted by the numerical NeuCosmA model. No significant
excess was found, so 90% confidence upper limits on the fluxes as expected from
analytically approximated neutrino-emission models as well as on up-to-date
numerical predictions were placed.


title: Shear viscosity due to the Landau damping from quark-pion interaction

abstract:
  We have calculated the shear viscosity coefficient $\eta$ of the strongly
interacting matter in the relaxation time approximation, where a quasi particle
description of quarks with its dynamical mass is considered from NJL model. Due
to the thermodynamic scattering of quarks with pseudo scalar type condensate
(i.e. pion), a non zero Landau damping will be acquired by the propagating
quarks. This Landau damping may be obtained from the Landau cut contribution of
the in-medium self-energy of quark-pion loop, which is evaluated in the
framework of real-time thermal field theory.


title:
Fine structure of the confining string in an analytically solvable 3D
  model

abstract:
  In $\mathrm{U(1)}$ lattice gauge theory in three spacetime dimensions,
confinement can be analytically shown to persist at all values of the coupling.
Furthermore, the explicit predictions for the dependence of string tension
$\sigma$ and mass gap $m_0$ on the coupling allow one to tune their ratio at
will. These features, and the possibility of obtaining high-precision numerical
results via an exact duality map to a spin model, make this theory an ideal
laboratory to test the effective string description of confining flux tubes. In
this contribution, we discuss our investigation of next-to-leading-order
corrections to the confining potential and of the finite-temperature behavior
of the flux tube width. Our data provide a very stringent test of the
theoretical predictions for these quantities and allow to test their dependence
on the $m_0/\sqrt{\sigma}$ ratio.


title: Almost CR quaternionic manifolds and their immersibility in HP^n

abstract:
  We apply the general theory of codimension one integrability conditions for
$G$-structures developed in arXiv:1306.6817v3 [math.DG] to the case of
quaternionic CR geometry. We obtain necessary and sufficient conditions for an
almost CR quaternionic manifold to admit local immersions as an hypersurface of
the quaternionic projective space. We construct a deformation of the standard
quaternionic contact structure on the quaternionic Heisenberg group which does
not admit local immersions in any quaternionic manifold.


title:
Tensor product of cyclic A$_\infty$-algebras and their Kontsevich
  classes

abstract:
  Given two cyclic A$_\infty$-algebras $A$ and $B$, we prove that there exists
a cyclic A$_\infty$-algebra structure on their tensor product $A\otimes B$
which is unique up to a cyclic A$_\infty$-quasi-isomorphism. Furthermore, the
Kontsevich class of $A\otimes B$ is equal to the cup product of the Kontsevich
classes of $A$ and $B$ on the moduli space of curves.


title:
Option Pricing with Lie Symmetry Analysis and Similarity Reduction
  Method

abstract:
  With some transformations, we convert the problem of option pricing under
state-dependent volatility into an initial value problem of the Fokker-Planck
equation with a certain potential. By using the Lie symmetry analysis and
similarity reduction method, we are able to reduce the dimensions of the
partial differential equation and find some of its particular solutions of the
equation. A few case studies demonstrate that our new method can be used to
produce analytical option pricing formulas for certain volatility functions.


title: A thermostatistical approach to scale-free networks

abstract:
  We describe an ensemble of growing scale-free networks in an equilibrium
framework, providing insight into why the exponent of empirical scale-free
networks in nature is typically robust. In an analogy to thermostatistics, to
describe the canonical and microcanonical ensembles, we introduce a functional,
whose maximum corresponds to a scale-free configuration. We then identify the
equivalents to energy, Zeroth-law, entropy and heat capacity for scale-free
networks. Discussing the merging of scale-free networks, we also establish an
exact relation to predict their final "equilibrium" degree exponent. All
analytic results are complemented with Monte Carlo simulations. Our approach
illustrates the possibility to apply the tools of equilibrium statistical
physics to study the properties of growing networks, and it also supports the
recent arguments on the complementarity between equilibrium and nonequilibrium
systems.


title:
A comment on estimating sensitivity to neutrino mass hierarchy in
  neutrino experiments

abstract:
  Recently it has been proposed, in the context of experiments designed to
resolve the neutrino mass hierarchy, to use the average posterior probability
of one of the hypotheses as a measure of sensitivity of future experiments.
This has led to sensitivity estimates that are drastically lower than common
conventions. We point to the fact that such estimates can be severely
misleading: the probability that an experiment would actually produce a result
similar to the average value can be in fact negligibly small. We emphasize
again the simple relation between median significance and the likelihood ratio
evaluated with the ``Asimov'' data set, which can be used to express
experimental sensitivity in Bayesian terms as well.


title: Superbroad Component in Emission Lines of SS 433

abstract:
  We have detected new components in stationary emission lines of SS 433; these
are the superbroad components that are low-contrast substrates with a width of
2000--2500 km s-1 in He I $\lambda4922$ and H$\beta$ and 4000--5000 km s-1 in
He II $\lambda4686$. Based on 44 spectra taken during four years of
observations from 2003 to 2007, we have found that these components in the He
II and He I lines are eclipsed by the donor star; their behavior with
precessional and orbital phases is regular and similar to the behavior of the
optical brightness of SS 433. The same component in H$\beta$ shows neither
eclipses nor precessional variability. We conclude that the superbroad
components in the helium and hydrogen lines are different in origin. Electron
scattering is shown to reproduce well the superbroad component of H$\beta$ at a
gas temperature of 20--35 kK and an optical depth for Thomson scattering $\tau
\approx$ 0.25--0.35. The superbroad components of the helium lines are probably
formed in the wind from the supercritical accretion disk. We have computed a
wind model based on the concept of Shakura-Sunyaev supercritical disk
accretion. The main patterns of the He II line profiles are well reproduced in
this model: not only the appearance of the superbroad component but also the
evolution of the central two-component part of the profile of this line during
its eclipse by the donor star can be explained.


title: Skew and implied leverage effect: smile dynamics revisited

abstract:
  We revisit the ``Smile Dynamics'' problem, which consists in relating the
implied leverage (i.e. the correlation of the at-the-money volatility with the
returns of the underlying) and the skew of the option smile. The ratio between
these two quantities, called ``Skew-Stickiness Ratio'' (SSR) by Bergomi (Smile
Dynamics IV, RISK, 94-100, December 2009), saturates to the value 2 for linear
models in the limit of small maturities, and converges to 1 for long
maturities. We show that for more general, non-linear models (such as the
asymmetric GARCH model), Bergomi's result must be modified, and can be larger
than 2 for small maturities. The discrepancy comes from the fact that the
volatility skew is, in general, different from the skewness of the underlying.
We compare our theory with empirical results, using data both from option
markets and from the underlying price series, for the S&P500 and the DAX. We
find, among other things, that although both the implied leverage and the skew
appear to be too strong on option markets, their ratio is well explained by the
theory. We observe that the SSR indeed becomes larger than 2 for small
maturities.


title:
Escaping the poverty trap: modeling the interplay between economic
  growth and the ecology of infectious disease

abstract:
  The dynamics of economies and infectious disease are inexorably linked:
economic well-being influences health (sanitation, nutrition, treatment
capacity, etc.) and health influences economic well-being (labor productivity
lost to sickness and disease). Often societies are locked into "poverty traps"
of poor health and poor economy. Here, using a simplified coupled
disease-economic model with endogenous capital growth we demonstrate the
formation of poverty traps, as well as ways to escape them. We suggest two
possible mechanisms of escape both motivated by empirical data: one, through an
influx of capital (development aid), and another through changing the
percentage of GDP spent on healthcare. We find that a large influx of capital
is successful in escaping the poverty trap, but increasing health spending
alone is not. Our results demonstrate that escape from a poverty trap may be
possible, and carry important policy implications in the world-wide
distribution of aid and within-country healthcare spending.


title: Two-dimensional quasi-ideal Fermi gas with Rashba spin-orbit coupling

abstract:
  We investigate the zero-temperature properties of a quasi-ideal Fermi gas
with Rashba spin-orbit coupling. We find that the spin-orbit term strongly
affects the speeds of zero sound and first sound in the Fermi gas, due to the
presence of a third-order quantum phase transition. In addition, including a 2D
harmonic confinement we show that also the shape of the density profile of the
cloud crucially depends on the strength of the Rashba coupling.


title:
Magnetic response to applied electrostatic field in external magnetic
  field

abstract:
  We show, within QED and other possible nonlinear theories, that a static
charge localized in a finite domain of space becomes a magnetic dipole, if it
is placed in an external (constant and homogeneous) magnetic field in the
vacuum. The magnetic moment is quadratic in the charge, depends on its size and
is parallel to the external field, provided the charge distribution is at least
cylindrically symmetric. This magneto-electric effect is a nonlinear response
of the magnetized vacuum to an applied electrostatic field. Referring to a
simple example of a spherically-symmetric applied field, the nonlinearly
induced current and its magnetic field are found explicitly throughout the
space, the pattern of lines of force is depicted, both inside and outside the
charge, which resembles that of a standard solenoid of classical
magnetostatics.


title:
Can a biologically-plausible hierarchy effectively replace face
  detection, alignment, and recognition pipelines?

abstract:
  The standard approach to unconstrained face recognition in natural
photographs is via a detection, alignment, recognition pipeline. While that
approach has achieved impressive results, there are several reasons to be
dissatisfied with it, among them is its lack of biological plausibility. A
recent theory of invariant recognition by feedforward hierarchical networks,
like HMAX, other convolutional networks, or possibly the ventral stream,
implies an alternative approach to unconstrained face recognition. This
approach accomplishes detection and alignment implicitly by storing
transformations of training images (called templates) rather than explicitly
detecting and aligning faces at test time. Here we propose a particular
locality-sensitive hashing based voting scheme which we call "consensus of
collisions" and show that it can be used to approximate the full 3-layer
hierarchy implied by the theory. The resulting end-to-end system for
unconstrained face recognition operates on photographs of faces taken under
natural conditions, e.g., Labeled Faces in the Wild (LFW), without aligning or
cropping them, as is normally done. It achieves a drastic improvement in the
state of the art on this end-to-end task, reaching the same level of
performance as the best systems operating on aligned, closely cropped images
(no outside training data). It also performs well on two newer datasets,
similar to LFW, but more difficult: LFW-jittered (new here) and SUFR-W.


title: Inheriting of chaos in nonautonomous dynamical systems

abstract:
  We consider nonautonomous discrete dynamical systems $\{ f_n\}_{n\ge 1}$,
where every $f_n$ is a surjective continuous map $[0,1]\to [0,1]$ such that
$f_n$ converges uniformly to a map $f$. We show, among others, that if $f$ is
chaotic in the sense of Li and Yorke then the nonautonomous system $ \{
f_n\}_{n\ge 1}$ is Li-Yorke chaotic as well, and that the same is true for
distributional chaos. If $f$ has zero topological entropy then the
nonautonomous system inherits its infinite $\omega$-limit sets.


abstract:
  The CALET Gamma-ray Burst Monitor (CGBM) is the secondary scientific
instrument of the CALET mission on the International Space Station (ISS), which
is scheduled for launch by H-IIB/HTV in 2014. The CGBM provides a broadband
energy coverage from 7 keV to 20 MeV, and simultaneous observations with the
primary instrument Calorimeter (CAL) in the GeV - TeV gamma-ray range and
Advanced Star Camera (ASC) in the optical for gamma-ray bursts (GRBs) and other
X-gamma-ray transients. The CGBM consists of two kinds of scintillators: two
LaBr$_3$(Ce) (7 keV - 1 MeV) and one BGO (100 keV - 20 MeV) each read by a
single photomultiplier. The LaBr$_3$(Ce) crystal, used in space for the first
time here for celestial gamma-ray observations, enables GRB observations over a
broad energy range from low energy X-ray emissions to gamma rays. The detector
performance and structures have been verified using the bread-board model (BBM)
via vibration and thermal vacuum tests. The CALET is currently in the
development phase of the proto-flight model (PFM) and the pre-flight
calibration of the CGBM is planned for August 2013. In this paper, we report on
the current status and expected performance of CALET for GRB observations.


title:
Motions in liquid-vapour interfaces by using a continuous mechanical
  model

abstract:
  By using a limit analysis for the motion equations of viscous fluid endowed
with internal capillarity, we are able to propose a dynamical expression for
the surface tension of moving liquid-vapour interfaces without any
phenomenological assumption. The proposed relation extends the static case,
yields the Laplace formula in cases of mass transfer across interfacial layers
and allows to take the second coefficient of viscosity of compressible fluids
into account. We generalize the Maxwell rule in dynamics and directly explain
the Marangoni effect.


title: A hybrid decision support system : application on healthcare

abstract:
  Many systems based on knowledge, especially expert systems for medical
decision support have been developed. Only systems are based on production
rules, and cannot learn and evolve only by updating them. In addition, taking
into account several criteria induces an exorbitant number of rules to be
injected into the system. It becomes difficult to translate medical knowledge
or a support decision as a simple rule. Moreover, reasoning based on generic
cases became classic and can even reduce the range of possible solutions. To
remedy that, we propose an approach based on using a multi-criteria decision
guided by a case-based reasoning (CBR) approach.


title:
Finding New Superconductors: The Spin-Fluctuation Gateway to High Tc and
  Possible Room Temperature Superconductivity

abstract:
  We propose an experiment-based strategy for finding new high transition
temperature superconductors that is based on the well-established spin
fluctuation magnetic gateway to superconductivity in which the attractive
quasiparticle interaction needed for superconductivity comes from their
coupling to dynamical spin fluctuations originating in the proximity of the
material to an antiferromagnetic state. We show how lessons learned by
combining the results of almost three decades of intensive experimental and
theoretical study of the cuprates with those found in the decade-long study of
a strikingly similar family of unconventional heavy electron superconductors,
the 115 materials, can prove helpful in carrying out that search. We conclude
that since Tc in these materials scales approximately with the strength of the
interaction, J, between the nearest neighbor local moments in their parent
antiferromagnetic state, there may not be a magnetic ceiling that would prevent
one from discovering a room temperature superconductor.


title:
The Optimization of Running Queries in Relational Databases Using
  ANT-Colony Algorithm

abstract:
  The issue of optimizing queries is a cost-sensitive process and with respect
to the number of associated tables in a query, its number of permutations grows
exponentially. On one hand, in comparison with other operators in relational
database, join operator is the most difficult and complicated one in terms of
optimization for reducing its runtime. Accordingly, various algorithms have so
far been proposed to solve this problem. On the other hand, the success of any
database management system (DBMS) means exploiting the query model. In the
current paper, the heuristic ant algorithm has been proposed to solve this
problem and improve the runtime of join operation. Experiments and observed
results reveal the efficiency of this algorithm compared to its similar
algorithms.


title: Nonassociative algebras and groups with property ($T$)

abstract:
  We extend the results of \cite{EJK} on property (T) to certain groups
"coordinatized" by nonassociative algebras.


title: Distance two labeling of direct product of paths and cycles

abstract:
  Suppose that $[n]=\left\{0,1,2,...,n\right\}$ is a set of non-negative
integers and $h,k \in [n]$. The $L(h,k)$-labeling of graph $G$ is the function
$l:V(G)\rightarrow[n]$ such that $\left|l(u)-l(v)\right|\geq h$ if the distance
$d(u,v)$ between $u$ and $v$ is one and $\left|l(u)-l(v)\right| \geq k$ if the
distance $d(u,v)$ is two. Let $L(V(G))=\left\{l(v): v \in V(G)\right\}$ and let
$p$ be the maximum value of $L(V(G)).$ Then $p$ is called $\lambda_h^k-$number
of $G$ if $p$ is the least possible member of $[n]$ such that $G$ maintains an
$L(h,k)-$labeling. In this paper, we establish $\lambda_1^1-$ numbers of $P _m
\times C_n$ graphs for all $m \geq 2$ and $n\geq 3$.


title:
Maximum likelihood versus likelihood-free quantum system identification
  in the atom maser

abstract:
  We consider the system identification problem of estimating a dynamical
parameter of a Markovian quantum open system (the atom maser), by performing
continuous time measurements in the system's output (outgoing atoms). Two
estimation methods are investigated and compared. On the one hand, the maximum
likelihood estimator (MLE) takes into account the full measurement data and is
asymptotically optimal in terms of its mean square error. On the other hand,
the `likelihood-free' method of approximate Bayesian computation (ABC) produces
an approximation of the posterior distribution for a given set of summary
statistics, by sampling trajectories at different parameter values and
comparing them with the measurement data via chosen statistics.
  Our analysis is performed on the atom maser model, which exhibits interesting
features such as bistability and dynamical phase transitions, and has
connections with the classical theory of hidden Markov processes. Building on
previous results which showed that atom counts are poor statistics for certain
values of the Rabi angle, we apply MLE to the full measurement data and
estimate its Fisher information. We then select several correlation statistics
such as waiting times, distribution of successive identical detections, and use
them as input of the ABC algorithm. The resulting posterior distribution
follows closely the data likelihood, showing that the selected statistics
contain `most' statistical information about the Rabi angle.


title: Some new light on a few classical results

abstract:
  The purpose of this paper is to describe a unified approach to proving
vector-valued inequalities without relying on the full strength of weighted
theory. Our applications include the Fefferman-Stein and Cordoba-Fefferman
inequalities, as well as the vector-valued Carleson operator. Using this
approach we also produce a proof of the boundedness of the classical
bi-parameter multiplier operators, that does not rely on product theory. Our
arguments are inspired by the vector valued restricted type interpolation used
in [1].


title: Alfven Wave Solar Model (AWSoM): Coronal Heating

abstract:
  We present a new version of the Alfven Wave Solar Model (AWSoM), a global
model from the upper chromosphere to the corona and the heliosphere. The
coronal heating and solar wind acceleration are addressed with low-frequency
Alfven wave turbulence. The injection of Alfven wave energy at the inner
boundary is such that the Poynting flux is proportional to the magnetic field
strength. The three-dimensional magnetic field topology is simulated using data
from photospheric magnetic field measurements. This model does not impose
open-closed magnetic field boundaries; those develop self-consistently. The
physics includes: (1) The model employs three different temperatures, namely
the isotropic electron temperature and the parallel and perpendicular ion
temperatures. The firehose, mirror, and ion-cyclotron instabilities due to the
developing ion temperature anisotropy are accounted for. (2) The Alfven waves
are partially reflected by the Alfven speed gradient and the vorticity along
the field lines. The resulting counter-propagating waves are responsible for
the nonlinear turbulent cascade. The balanced turbulence due to uncorrelated
waves near the apex of the closed field lines and the resulting elevated
temperatures are addressed. (3) To apportion the wave dissipation to the three
temperatures, we employ the results of the theories of linear wave damping and
nonlinear stochastic heating. (4) We have incorporated the collisional and
collisionless electron heat conduction. We compare the simulated
multi-wavelength EUV images of CR2107 with the observations from STEREO/EUVI
and SDO/AIA instruments. We demonstrate that the reflection due to strong
magnetic fields in proximity of active regions intensifies the dissipation and
observable emission sufficiently.


title:
Coexisting Itinerant and Localized Electrons in Iron-Based
  Superconductors

abstract:
  The surprising discovery of high-$T_c$ superconductivity in iron-based
compounds has prompted an intensive investigation on the role of interaction
and magnetism in the these materials. Based on the general features of
multi-bands and intermediate coupling strengths, a phenomenological theory of
coexisting itinerant and localized electrons has been proposed to describe the
low-energy physics in iron-based superconductors. It provides a unified
framework to understand magnetic, superconducting, and normal phases, subject
to further microscopic justification and experimental verification.


title:
Measuring the ground-state wave functional of SU(2) Yang-Mills theory in
  3+1 dimensions: Abelian plane waves

abstract:
  A method of measuring relative probabilities of various gauge-field
configurations in the Yang-Mills vacuum was proposed long ago [Phys. Lett. B
223 (1989) 207]. We applied this method to compute the square of the YM vacuum
wave functional (VWF) in numerical simulations of SU(2) lattice gauge theory in
D=3+1 dimensions for sets of abelian plane waves. The results were compared to
predictions based on some VWF proposals in the literature. None of them
describes the data satisfactorily at large plane-wave momenta. The
phenomenological best fit to data, containing three free parameters, appears to
reduce in the continuum limit to the approximate form proposed in [Phys. Rev. D
77 (2008) 065003].


title: Distributed Data Storage Systems with Opportunistic Repair

abstract:
  The reliability of erasure-coded distributed storage systems, as measured by
the mean time to data loss (MTTDL), depends on the repair bandwidth of the
code. Repair-efficient codes provide reliability values several orders of
magnitude better than conventional erasure codes. Current state of the art
codes fix the number of helper nodes (nodes participating in repair) a priori.
In practice, however, it is desirable to allow the number of helper nodes to be
adaptively determined by the network traffic conditions. In this work, we
propose an opportunistic repair framework to address this issue. It is shown
that there exists a threshold on the storage overhead, below which such an
opportunistic approach does not lose any efficiency from the optimal
storage-repair-bandwidth tradeoff; i.e. it is possible to construct a code
simultaneously optimal for different numbers of helper nodes. We further
examine the benefits of such opportunistic codes, and derive the MTTDL
improvement for two repair models: one with limited total repair bandwidth and
the other with limited individual-node repair bandwidth. In both settings, we
show orders of magnitude improvement in MTTDL. Finally, the proposed framework
is examined in a network setting where a significant improvement in MTTDL is
observed.


title: Existence results for incompressible magnetoelasticity

abstract:
  We investigate a variational theory for magnetoelastic solids under the
incompressibility constraint. The state of the system is described by
deformation and magnetization. While the former is classically related to the
reference configuration, magnetization is defined in the deformed configuration
instead. We discuss the existence of energy minimizers without relying on
higher-order deformation gradient terms. Then, by introducing a suitable
positively $1$-homogeneous dissipation, a quasistatic evolution model is
proposed and analyzed within the frame of energetic solvability.


title: Dark Energy from holographic theories with hyperscaling violation

abstract:
  We show that analytical continuation maps scalar solitonic solutions of
Einstein-scalar gravity, interpolating between an hyperscaling violating and an
Anti de Sitter (AdS) region, in flat FLRW cosmological solutions sourced by a
scalar field. We generate in this way exact FLRW solutions that can be used to
model cosmological evolution driven by dark energy (a quintessence field) and
usual matter. In absence of matter, the flow from the hyperscaling violating
regime to the conformal AdS fixed point in holographic models corresponds to
cosmological evolution from power-law expansion at early cosmic times to a de
Sitter (dS) stable fixed point at late times. In presence of matter, we have a
scaling regime at early times, followed by an intermediate regime in which dark
energy tracks matter. At late times the solution exits the scaling regime with
a sharp transition to a dS spacetime. The phase transition between hyperscaling
violation and conformal fixed point observed in holographic gravity has a
cosmological counterpart in the transition between a scaling era and a dS era
dominated by the energy of the vacuum.


title:
Discontinuous shear thickening without inertia in dense non-Brownian
  suspensions

abstract:
  A consensus is emerging that discontinuous shear thickening (DST) in dense
suspensions marks a transition from a flow state where particles remain well
separated by lubrication layers, to one dominated by frictional contacts. We
show here that reasonable assumptions about contact proliferation predict two
distinct types of DST in the absence of inertia. The first occurs at densities
above the jamming point of frictional particles; here the thickened state is
completely jammed and (unless particles deform) cannot flow without
inhomogeneity or fracture. The second regime shows strain- rate hysteresis and
arises at somewhat lower densities where the thickened phase flows smoothly.
DST is predicted to arise when finite-range repulsions defer contact formation
until a characteristic stress level is exceeded.


title:
High-efficiency degenerate four wave-mixing in triply resonant nanobeam
  cavities

abstract:
  We demonstrate high-efficiency, degenerate four-wave mixing in triply
resonant Kerr $\chi^(3)$ photonic crystal (PhC) nanobeam cavities. Using a
combination of temporal coupled mode theory and nonlinear finite-difference
time-domain (FDTD) simulations, we study the nonlinear dynamics of resonant
four-wave mixing processes and demonstrate the possibility of observing
high-efficiency limit cycles and steady-state conversion corresponding to
$\approx 100$% depletion of the pump light at low powers, even including
effects due to losses, self- and cross-phase modulation, and imperfect
frequency matching. Assuming operation in the telecom range, we predict close
to perfect quantum efficiencies at reasonably low $\sim$ 50 mW input powers in
silicon micrometer-scale cavities.


title: Flavor Physics Constraints on TeV Scale Color Sextet Scalars

abstract:
  In this work we present an analysis of flavor violating effects mediated by
color sextet scalars, which arise naturally in left-right symmetric gauge
theories based on SU(2)_L \times SU(2)_R \times SU(4)_C group. The sextets,
denoted here by \Delta_{dd}, Delta_{ud} and \Delta_{uu}, couple to
right--handed quarks. We delineate the constraints on these couplings arising
from meson--anti-meson transitions and flavor changing weak decays. The sextet
\Delta_{uu} mediates D^{0}-\bar{D}^{0} mixing via tree-level and box diagrams,
and also mediates D --> K pi, pi pi decays. The sextets \Delta_{ud} and
\Delta_{dd} mediate B_{d}^{0}-\bar{B}_{d}^{0}, B_{s}^{0}-\bar{B}_{s}^{0} and
K^{0}-\bar{K}^{0} mixings as well as rare B and D meson decays. Our analysis
shows that for coupling strengths of order 10^{-2}, the current experimental
data requires the mass of these color sextets to exceed several TeV. These
bounds are stronger than those obtained from direct LHC searches.


title:
The close environment of high-mass X-ray binaries at high angular
  resolution I. VLTI/AMBER and VLTI/PIONIER near-infrared interferometric
  observations of Vela X-1

abstract:
  Recent improvements on the sensitivity and spectral resolution of X-ray
observations have led to a better understanding of the properties of matter in
the vicinity of High Mass X-ray Binaries hosting a supergiant star and a
compact object. However the geometry and physical properties of their
environment at larger scales are currently only predicted by simulations. We
aim at exploring the environment of Vela X-1 at a few stellar radii of the
supergiant using spatially resolved observations in the near-infrared and at
studying its dynamical evolution along the 9-day orbital period of the system.
We observed Vela X-1 in 2010 and 2012 using long baseline interferometry at
VLTI, respectively with the AMBER instrument in the K band and the PIONIER
instrument in the H band. The PIONIER observations span through one orbital
period to monitor possible evolutions in the geometry of the system. We
resolved a structure of $8\pm3~R_\star$ from the AMBER data and
$2.0\,_{-1.2}^{+0.7}~R_\star$ from the PIONIER data. From the closure phase we
found that the environment of Vela X-1 is symmetrical. We observed comparable
measurements between the continuum and the spectral lines in the K band,
meaning that both emissions originate from the same forming region. From the
monitoring of the system over one period in 2012, we found the signal to be
constant with the orbital phase within the error bars. We propose three
scenarios for the discrepancy between the two measurements: either there is a
strong temperature gradient in the supergiant wind leading to a hot component
much more compact than the cool part of the wind observed in the K band, or we
observed a diffuse shell in 2010 possibly triggered by an off-state in the
accretion rate of the pulsar that was dissolved in the interstellar medium in
2012, or the structure observed in the H band was the stellar photosphere
instead of the supergiant wind.


title: Rotating-crystal Malaria Diagnosis: Pre-clinical validation

abstract:
  Improving the efficiency of malaria diagnosis is one of the main goals of
current malaria research. We have recently developed a magneto-optical (MO)
method which allows high-sensitivity detection of malaria pigment (hemozoin)
crystals via their magnetically induced rotation in blood. Here, we validate
this technique on laboratory derived blood samples infected with
\textit{Plasmodium falciparum}. Using two parasite cultures, the first
containing mostly ring stages and the second corresponding to the end of the
parasite life cycle, we demonstrate that our novel method can detect parasite
densities as low as $\sim$40 and $\sim$10\,parasites per microliter of blood
for ring and schizont stage parasites, respectively. This detection limit
exceeds the performance of rapid diagnostic tests and competes with the
threshold achievable by light microscopic observation of blood smears. Our
method can be performed with as little as 50\,microliter of capillary blood and
is sensitive to the presence of hemozoin micro-crystals down to ppm
concentrations. The device, designed to a portable format for clinical and
in-field tests, requires no special training of the operator or specific
reagents, except for an inexpensive lysis solution to release intracellular
hemozoin. Beyond diagnostics, this technique may offer an efficient tool to
study hemozoin formation, trace hemozoin kinetics in the body and test
susceptibility/resistance of parasites to new antimalarial drugs inhibiting
hemozoin formation.


title: Intermittent process analysis with scattering moments

abstract:
  Scattering moments provide nonparametric models of random processes with
stationary increments. They are expected values of random variables computed
with a nonexpansive operator, obtained by iteratively applying wavelet
transforms and modulus nonlinearities, which preserves the variance. First- and
second-order scattering moments are shown to characterize intermittency and
self-similarity properties of multiscale processes. Scattering moments of
Poisson processes, fractional Brownian motions, L\'{e}vy processes and
multifractal random walks are shown to have characteristic decay. The
Generalized Method of Simulated Moments is applied to scattering moments to
estimate data generating models. Numerical applications are shown on financial
time-series and on energy dissipation of turbulent flows.


title: Topological insulator states in quasi-one-dimensional sawtooth chain

abstract:
  We report the discovery of flatten Bloch bands with nontrivial topological
numbers in a quasi-one-dimensional sawtooth chain. We present the nearly
flat-band with a obvious gap and nonzero Chern number of the modulated sawtooth
chain by tuning hoppings and modulation. With the increasing of the strength of
the modulation, the system undergos a series of topological phase transitions
in the absence of interaction. By adding interaction to the model, we present
exact diagonalization results for the system at $1/3$ filling and some
interesting connections with fraction quantum Hall states: topological
degeneracy, nontrivially topological number and fractional statistic of the
quasihole.


title:
Global Solvability and Vanishing Shear Viscosity Limit of Planar
  Magnetohydrodynamic Equations with Large Initial Data

abstract:
  By observing a new relation between the magnetic pressure and the
hydrodynamic pressure, global existence of classical solution to the full
perfect MHD equations with large data is established, in particular including
the case when all the viscosity, heat conductivity and diffusivity coefficients
are constant. This can be viewed as an analog of the classical work by
Kazhikhov-Shelukhin for the Navier-Stokes equations to the MHD equations. In
addition, the vanishing shear viscosity limit is proved.


title: Micro-modulated luminescence tomography

abstract:
  Imaging depth of optical microscopy has been fundamentally limited to
millimeter or sub-millimeter due to light scattering. X-ray microscopy can
resolve spatial details of few microns deeply inside a sample but the contrast
resolution is still inadequate to depict heterogeneous features at cellular or
sub-cellular levels. To enhance and enrich biological contrast at large imaging
depth, various nanoparticles are introduced and become essential to basic
research and molecular medicine. Nanoparticles can be functionalized as imaging
probes, similar to fluorescent and bioluminescent proteins. LiGa5O8:Cr3+
nanoparticles were recently synthesized to facilitate luminescence energy
storage with x-ray pre-excitation and the subsequently stimulated luminescence
emission by visible/near-infrared (NIR) light. In this paper, we suggest a
micro-modulated luminescence tomography (MLT) approach to quantify a
nanophosphor distribution in a thick biological sample with high resolution.
Our numerical simulation studies demonstrate the feasibility of the proposed
approach.


title:
Maximally Entangled Mode, Metal-Insulator Transition and Violation of
  Entanglement Area Law in Non-interacting Fermion Ground States

abstract:
  We study in this work the ground state entanglement properties of two models
of non-interacting fermions moving in one-dimension (1D), that exhibit
metal-insulator transitions. We find that entanglement entropy grows either
logarithmically or in a power-law fashion in the metallic phase, thus violating
the (1D version of) entanglement area law. No such violation is found in the
insulating phase. We further find that characteristics of {\em single fermion}
states at the Fermi energy (which can {\em not} be obtained from the
many-fermion Slater determinant) is captured by the lowest energy single
fermion mode of the {\em entanglement} Hamiltonian; this is particularly true
at the metal-insulator transition point. Our results suggest entanglement is a
powerful way to detect metal-insulator transitions, {\em without} knowledge of
the Hamiltonian of the system.


title: Generalised Knight's Tours

abstract:
  The problem of existence of closed knight's tours in $[n]^d$, where $[n]=\{0,
1, \dots, n-1\}$, was recently solved by Erde, Gol\'{e}nia, and Gol\'{e}nia.
They raised the same question for a generalised, $(a, b)$ knight, which is
allowed to move along any two axes of $[n]^d$ by $a$ and $b$ unit lengths
respectively. Given an even number $a$, we show that the $[n]^d$ grid admits an
$(a, 1)$ knight's tour for sufficiently large even side length $n$.


title: Holographic superconductors with hidden Fermi surfaces

abstract:
  In this paper, we investigate a holographic model of superconductor with
hidden Fermi surfaces, which was defined by the logarithmic violation of area
law of entanglement entropy. We works in fully back-reacted background using
standard Einstein-Maxwell-Dilaton action with additional complex scalar filed
which was charged under the Maxwell field. Particularly, we analyze the
behavior of entanglement entropy during the phase transition. At the critical
point, the finite part of the entanglement entropy has a discontinuity of slope
and tends to a lower value in the superconducting phase all the way down to the
zero temperature limit, indicating the reorganization of degrees of freedom of
the system across the phase transition.


title: Dynamic Resource Allocation for Multiple-Antenna Wireless Power Transfer

abstract:
  We consider a point-to-point multiple-input-single-output (MISO) system where
a receiver harvests energy from a wireless power transmitter to power itself
for various applications. The transmitter performs energy beamforming by using
an instantaneous channel state information (CSI). The CSI is estimated at the
receiver by training via a preamble, and fed back to the transmitter. The
channel estimate is more accurate when longer preamble is used, but less time
is left for wireless power transfer before the channel changes. To maximize the
harvested energy, in this paper, we address the key challenge of balancing the
time resource used for channel estimation and wireless power transfer (WPT),
and also investigate the allocation of energy resource used for wireless power
transfer. First, we consider the general scenario where the preamble length is
allowed to vary dynamically. Taking into account the effects of imperfect CSI,
the optimal preamble length is obtained online by solving a dynamic programming
(DP) problem. The solution is shown to be a threshold-type policy that depends
only on the channel estimate power. Next, we consider the scenario in which the
preamble length is fixed. The optimal preamble length is optimized offline.
Furthermore, we derive the optimal power allocation schemes for both scenarios.
For the scenario of dynamic-length preamble, the power is allocated according
to both the optimal preamble length and the channel estimate power; while for
the scenario of fixed-length preamble, the power is allocated according to only
the channel estimate power. The analysis results are validated by numerical
simulations. Encouragingly, with optimal power allocation, the harvested energy
by using optimized fixed-length preamble is almost the same as the harvested
energy by employing dynamic-length preamble, hence allowing a low-complexity
WPT system to be implemented in practice.


title: Big Data Analytics in Future Internet of Things

abstract:
  Current research on Internet of Things (IoT) mainly focuses on how to enable
general objects to see, hear, and smell the physical world for themselves, and
make them connected to share the observations. In this paper, we argue that
only connected is not enough, beyond that, general objects should have the
capability to learn, think, and understand both the physical world by
themselves. On the other hand, the future IoT will be highly populated by large
numbers of heterogeneous networked embedded devices, which are generating
massive or big data in an explosive fashion. Although there is a consensus
among almost everyone on the great importance of big data analytics in IoT, to
date, limited results, especially the mathematical foundations, are obtained.
These practical needs impels us to propose a systematic tutorial on the
development of effective algorithms for big data analytics in future IoT, which
are grouped into four classes: 1) heterogeneous data processing, 2) nonlinear
data processing, 3) high-dimensional data processing, and 4) distributed and
parallel data processing. We envision that the presented research is offered as
a mere baby step in a potentially fruitful research direction. We hope that
this article, with interdisciplinary perspectives, will stimulate more
interests in research and development of practical and effective algorithms for
specific IoT applications, to enable smart resource allocation, automatic
network operation, and intelligent service provisioning.


title:
Quantum Anomalous Hall Effect in Magnetically Doped InAs/GaSb Quantum
  Wells

abstract:
  The quantum anomalous Hall effect has recently been observed experimentally
in thin films of Cr doped (Bi,Sb)$_2$Te$_3$ at a low temperature ($\sim$ 30mK).
In this work, we propose realizing the quantum anomalous Hall effect in more
conventional diluted magnetic semiconductors with doped InAs/GaSb type II
quantum wells. Based on a four band model, we find an enhancement of the Curie
temperature of ferromagnetism due to band edge singularities in the inverted
regime of InAs/GaSb quantum wells. Below the Curie temperature, the quantum
anomalous Hall effect is confirmed by the direct calculation of Hall
conductance. The parameter regime for the quantum anomalous Hall phase is
identified based on the eight-band Kane model. The high sample quality and
strong exchange coupling make magnetically doped InAs/GaSb quantum wells good
candidates for realizing the quantum anomalous Hall insulator at a high
temperature.


title:
New Results from the T2K Experiment: Observation of $\nu_e$ Appearance
  in a $\nu_\mu$ Beam

abstract:
  The T2K Experiment has observed the appearance of electron neutrinos in a
muon-neutrino beam. Twenty eight neutrino candidates pass the selection cuts
with a predicted background of $4.64 \pm 0.53$ events, which corresponds to a
6.8$\sigma$ exclusion of $\theta_{13} = 0$. When comparing the $\theta_{13} =
0$ hypothesis to the best fit of the full electron momentum and angle
distribution, $\theta_{13} = 0$ is excluded at 7.5$\sigma$ for $\sin^2
2\theta_{23} = 1$ and $\delta_{CP} = 0$. In addition, results from the T2K
$\nu_\mu$ disappearance analysis have also been updated to improve the
treatment of full 3-flavor oscillations.


title: A Proof Of The Block Model Threshold Conjecture

abstract:
  We study a random graph model named the "block model" in statistics and the
"planted partition model" in theoretical computer science. In its simplest
form, this is a random graph with two equal-sized clusters, with a
between-class edge probability of $q$ and a within-class edge probability of
$p$.
  A striking conjecture of Decelle, Krzkala, Moore and Zdeborov\'a based on
deep, non-rigorous ideas from statistical physics, gave a precise prediction
for the algorithmic threshold of clustering in the sparse planted partition
model. In particular, if $p = a/n$ and $q = b/n$, $s=(a-b)/2$ and $p=(a+b)/2$
then Decelle et al.\ conjectured that it is possible to efficiently cluster in
a way correlated with the true partition if $s^2 > p$ and impossible if $s^2 <
p$. By comparison, the best-known rigorous result is that of Coja-Oghlan, who
showed that clustering is possible if $s^2 > C p \ln p$ for some sufficiently
large $C$.
  In a previous work, we proved that indeed it is information theoretically
impossible to to cluster if $s^2 < p$ and furthermore it is information
theoretically impossible to even estimate the model parameters from the graph
when $s^2 < p$. Here we complete the proof of the conjecture by providing an
efficient algorithm for clustering in a way that is correlated with the true
partition when $s^2 > p$. A different independent proof of the same result was
recently obtained by Laurent Massoulie.


title:
In situ ore formation experiment: Amino acids and amino sugars trapped
  in artificial chimneys on deep-sea hydrothermal systems at Suiyo Seamount,
  Izu-Bonin Arc, Pacific Ocean

abstract:
  The present study reports on the bio-organic composition of a deep-sea
venting hydrothermal system originating from arc volcanism; the origin of the
particulates in hydrothermal fluids from the Suiyo Seamount in the southern
Izu-Bonin (Ogasawara) Arc is discussed with regard to amino compounds. Chimney
samples on deep-sea hydrothermal systems and core samples at Suiyo Seamount
were determined for amino acids, and occasionally amino sugars. Two types of
chimney samples were obtained from active hydrothermal systems by submersible
vehicles: one was natural chimney (NC) on a hydrothermal natural vent; the
other was artificial chimneys (AC), mainly formed by the growth and deposition
of sulfide-rich particulate components in a Kuwabara-type in situ incubator (KI
incubator). Total hydrolyzed amino acids (THAA) and hydrolyzed hexosamines (HA)
in AC ranged from 10.7 nmol/g to 64.0 nmol/g and from 0 nmol/g to 8.1 nmol/g,
respectively, while THAA in hydrothermally altered core samples ranged from
26.0 nmol/g to 107.4 nmol/g-rock. The THAA was thus of the same order of
magnitude in AC and core samples. The representative biochemical indicator
ratios of {\beta}-alanine/aspartic acid and {\gamma}-aminobutyric acid/glutamic
acid were low. This is consistent with a large microbial population and labile
subterranean biogenic organic compounds. A micro energy dispersive X-ray
spectrometer ({\mu}EDX) was used to show that the formation of massive pyrite-
and chalcopyrite-ores, the major matrixes of the natural chimney structures,
were processed during hydrothermal activity. These data suggest that labile
particulate organic matter (POM) and/or dissolved organic matter (DOM) from
hydrothermal fluid were continuously trapped to form concentrated organic
matter in a sulfide-rich matrix.


title:
Parameter Estimation in Hidden Markov Models with Intractable
  Likelihoods Using Sequential Monte Carlo

abstract:
  We propose sequential Monte Carlo based algorithms for maximum likelihood
estimation of the static parameters in hidden Markov models with an intractable
likelihood using ideas from approximate Bayesian computation. The static
parameter estimation algorithms are gradient based and cover both offline and
online estimation. We demonstrate their performance by estimating the
parameters of three intractable models, namely the alpha-stable distribution,
g-and-k distribution, and the stochastic volatility model with alpha-stable
returns, using both real and synthetic data.


title: A refinement of Brascamp-Lieb-Poincare inequality in one dimension

abstract:
  In this short note we give a refinement of Brascamp-Lieb in the style of
Houdre-Kagan extension for Poincare inequality in one dimension. This is
inspired by works of Helffer and Ledoux.


title: Global bifurcation diagram for the Kerner-Konhauser traffic flow model

abstract:
  We study traveling wave solutions of the Kerner--Konh\"auser PDE for traffic
flow. By a standard change of variables, the problem is reduced to a dynamical
system in the plane with three parameters. In a previous paper (Carrillo, F.A.,
J. Delgado, P. Saavedra, R.M. Velasco and F. Verduzco, (2013). Traveling waves,
catastrophes and bifurcations in a generic second order traffic flow model --to
appear in \textit{International Journal of Bifurcation and Chaos}--, it was
shown that under general hypotheses on the fundamental diagram, the dynamical
system has a surface of critical points showing either a fold or cusp
catastrophe when projected under a two dimensional plane of parameters named
$q_g$--$v_g$. In any case a one parameter family of Bogdanov--Takens (BT)
bifurcation takes place, and therefore local families of Hopf and homoclinic
bifurcation arising from each BT point exist. Here we prove the existence of a
degenerate Bogdanov--Takens bifurcation (DBT) which in turn implies the
existence of Generalized Hopf or Bautin bifurcations (GH). We describe
numerically the global lines of bifurcations continued from the local ones,
inside a cuspidal region of the parameter space. In particular, we compute the
first Lyapunov exponent, and compare with the GH bifurcation curve. We present
some families of stable limit cycles which are taken as initial conditions in
the PDE leading to stable traveling waves.


title:
Fast and Accurate Evaluation of Nonlocal Coulomb and Dipole-Dipole
  Interactions via the Nonuniform FFT

abstract:
  We present a fast and accurate algorithm for the evaluation of nonlocal
(long-range) Coulomb and dipole-dipole interactions in free space. The
governing potential is simply the convolution of an interaction kernel $U(\bx)$
and a density function $\rho(\bx)=|\psi(\bx)|^2$, for some complex-valued wave
function $\psi(\bx)$, permitting the formal use of Fourier methods. These are
hampered by the fact that the Fourier transform of the interaction kernel
$\widehat{U}(\bk)$ has a singularity at the origin $\bk={\bf 0}$ in Fourier
(phase) space. Thus, accuracy is lost when using a uniform Cartesian grid in
$\bk$ which would otherwise permit the use of the FFT for evaluating the
convolution. Here, we make use of a high-order discretization of the Fourier
integral, accelerated by the nonuniform fast Fourier transform (NUFFT). By
adopting spherical and polar phase-space discretizations in three and two
dimensions, respectively, the singularity in $\hat{U}(\bk)$ at the origin is
canceled, so that only a modest number of degrees of freedom are required to
evaluate the Fourier integral, assuming that the density function $\rho(\bx)$
is smooth and decays sufficiently fast as $\bx \rightarrow \infty$. More
precisely, the calculation requires $O(N\log N)$ operations, where $N$ is the
total number of discretization points in the computational domain. Numerical
examples are presented to demonstrate the performance of the algorithm.


title: Application of Rough Set Theory in Data Mining

abstract:
  Rough set theory is a new method that deals with vagueness and uncertainty
emphasized in decision making. Data mining is a discipline that has an
important contribution to data analysis, discovery of new meaningful knowledge,
and autonomous decision making. The rough set theory offers a viable approach
for decision rule extraction from data.This paper, introduces the fundamental
concepts of rough set theory and other aspects of data mining, a discussion of
data representation with rough set theory including pairs of attribute-value
blocks, information tables reducts, indiscernibility relation and decision
tables. Additionally, the rough set approach to lower and upper approximations
and certain possible rule sets concepts are introduced. Finally, some
description about applications of the data mining system with rough set theory
is included.


title:
Preparing arbitrary pure states of spatial qudits with a single
  phase-only spatial light modulator

abstract:
  Spatial qudits are D-dimensional ($D\geq 2$) quantum systems carrying
information encoded in the discretized transverse momentum and position of
single photons. We present a proof-of-principle demonstration of a method for
preparing arbitrary pure states of such systems by using a single phase-only
spatial light modulator (SLM). The method relies on the encoding of the complex
transmission function corresponding to a given spatial qudit state onto a
preset diffraction order of a phase-only grating function addressed at the SLM.
Fidelities of preparation above 94% were obtained with this method, which is
simpler, less costly, and more efficient than those that require two SLMs for
the same purpose.


title:
$\mathcal{PT}$-symmetry breaking in a necklace of coupled optical
  waveguides

abstract:
  We consider parity-time ($\mathcal{PT}$) symmetric arrays formed by $N$
optical waveguides with gain and $N$ waveguides with loss. When the gain-loss
coefficient exceeds a critical value $\gamma_c$, the $\mathcal{PT}$-symmetry
becomes spontaneously broken. We calculate $\gamma_c(N)$ and prove that
$\gamma_c \to 0$ as $N \to \infty$. In the symmetric phase, the periodic array
is shown to support $2N$ solitons with different frequencies and polarisations.


title: Blow-up regimes in the $\mathcal{PT}$- and the $\mathcal{AC}$-dimer

abstract:
  In the actively coupled ($\mathcal{AC}$) pair of waveguides, the growth of
small perturbations is saturated by the focussing nonlinearity that couples the
linearly growing to the linearly damped mode. On the other hand, in the
$\mathcal{PT}$-symmetric coupler, the focussing nonlinearity promotes the
blowup of stationary light beams. The purpose of this study is to compare the
nonlinear dynamics and explain the opposite effect of the same nonlinearity in
the two systems. We show that while the blowup regimes are stable in the
$\mathcal{PT}$-symmetric pair of waveguides, they are unstable and hence cannot
be observed in the $\mathcal{AC}$-dimer.


title: Polytropic process and tropical Cyclones

abstract:
  We show a parallelism between the expansion and compression of the atmosphere
in the secondary cycle of a tropical cyclone with the fast expansion and
compression of wet air in a bottle. We present a simple model in order to
understand how the system (cyclone) draws energy from the air humidity. In
particular we suggest that the upward (downward) expansion (compression) of the
warm (cold) moist (dry) air follows a polytropic process, $PV^\beta$= constant.
We show both experimentally and analytically that $\beta$ depends on the
initial vapor pressure in the air. We propose that the adiabatic stages in the
Carnot-cycle model for the tropical cyclone be replaced by two polytropic
stages. These polytropic processes can explain how the wind wins energy and how
the rain and the dry bands are produced inside the storm.


title: Temporal prediction of epidemic patterns in community networks

abstract:
  Most previous studies of epidemic dynamics on complex networks suppose that
the disease will eventually stabilize at either a disease-free state or an
endemic one. In reality, however, some epidemics always exhibit sporadic and
recurrent behaviour in one region because of the invasion from an endemic
population elsewhere. In this paper we address this issue and study a
susceptible-infected-susceptible epidemiological model on a network consisting
of two communities, where the disease is endemic in one community but
alternates between outbreaks and extinctions in the other. We provide a
detailed characterization of the temporal dynamics of epidemic patterns in the
latter community. In particular, we investigate the time duration of both
outbreak and extinction, and the time interval between two consecutive
inter-community infections, as well as their frequency distributions. Based on
the mean-field theory, we theoretically analyze these three timescales and
their dependence on the average node degree of each community, the transmission
parameters, and the number of intercommunity links, which are in good agreement
with simulations, except when the probability of overlaps between successive
outbreaks is too large. These findings aid us in better understanding the
bursty nature of disease spreading in a local community, and thereby suggesting
effective time-dependent control strategies.


title: Gravity gradient torque of spacecraft orbiting asteroids

abstract:
  Purpose: This paper presents a full fourth-order model of the gravity
gradient torque of spacecraft around asteroids by taking into consideration of
the inertia integrals of the spacecraft up to the fourth order, which is an
improvement of the previous fourth-order model of the gravity gradient torque.
Design, methodology and approach: The fourth-order gravitational potential of
the spacecraft is derived based on Taylor expansion. Then the expression of the
gravity gradient torque in terms of gravitational potential derivatives is
derived. By using the formulation of the gravitational potential, explicit
formulations of the full fourth-order gravity gradient torque are obtained.
Then a numerical simulation is carried out to verify our model. Findings: We
find that our model is more sound and precise than the previous fourth-order
model due to the consideration of higher-order inertia integrals of the
spacecraft. Numerical simulation results show that the motion of the previous
fourth-order model is quite different from the exact motion, while our full
fourth-order model fits the exact motion very well. Our full fourth-order model
is precise enough for high-precision attitude dynamics and control around
asteroids. Practical implications: This high-precision model is of importance
for the future asteroids missions for scientific explorations and near-Earth
objects mitigation. Originality and value: In comparison with the previous
model, a gravity gradient torque model around asteroids that is more sound and
precise is established. This model is valuable for high-precision attitude
dynamics and control around asteroids.


title: Dwyer-Kan localization revisited

abstract:
  A version of Dwyer-Kan localization in the context of infinity-categories and
simplicial categories is presented. Some results of the classical papers by
Dwyer and Kan on simplicial localization are reproven and generalized. It is
proven that a Quillen pair of model categories gives rise to an adjoint pair of
the DK localizations. Also a result on localization of a family of
infinity-categories is proven. This, in particular, is applied to localization
of symmetric monoidal infinity-categories, where some (partial) results are
obtained.


title:
Photon added nonlinear coherent states for a one mode field in a Kerr
  medium

abstract:
  We construct Deformed Photon Added Nonlinear Coherent States (DPANCSs) by
application of the deformed creation operator upon the Nonlinear Coherent
States obtained as eigenstates of the deformed annihilation operator and by
application of a deformed displacement operator upon the vacuum state. We
evaluate some statistical properties like the Mandel parameter, Husimi and
Wigner functions for these states and analyze their differences, we give closed
analytical expressions for them. We found a profound difference in the
statistical properties of the DPANCSs obtained from the two above mentioned
generalizations.


title: Rectification of algebras and modules

abstract:
  Let O be a topological (colored) operad. The Lurie infinity-category of
O-algebras with values in (infinity-category of) complexes is compared to the
infinity-category underlying the model category of (classical) dg O-algebras.
This can be interpreted as a "rectification" result for Lurie operad algebras.
A similar result is obtained for modules over operad algebras, as well as for
algebras over topological PROPs.


title: Maximal subalgebras of the classical linear Lie superalgebras

abstract:
  Dynkin's classification of maximal subalgebras of simple finite dimensional
complex Lie algebras is generalized to linear Lie superalgebras. Namely, the
maximal non-simple irreducible subalgebras of $\mathfrak{gl}(p|q),
\mathfrak{q}(n), \mathfrak{sl}(p|q), \mathfrak{osp}(m|2n), \mathfrak{pe}(n)$,
and $\mathfrak{spe}(n)$ are classified.


title: Differential systems of pure Gaussian type

abstract:
  We give the transformation rule for the Stokes data of the Laplace transform
of a differential system of pure Gaussian type.


title: A lower bound on the orbit growth of a regular self-map of affine space

abstract:
  We show that if $f : \mathbb{A}_{\bar{\mathbb{Q}}}^r \to
\mathbb{A}_{\bar{\mathbb{Q}}}^r$ is a regular self-map and $P \in
\mathbb{A}^r(\bar{\mathbb{Q}})$ has $\limsup_{n \in \mathbb{N}}
\frac{\log{h_{\mathrm{aff}}(f^nP)}}{\log{n}} < 1/r$, where $h_{\textrm{aff}}$
is the affine Weil height, then $\mathbb{N}$ partitions into a finite set and
finitely many full arithmetic progressions, on each of which the coordinates of
$f^nP$ are polynomials in $n$.
  In particular, if $(f^nP)_{n \in \mathbb{N}}$ is a Zariski-dense orbit, then
either $n = 1$ and $f$ is of the shape $t \mapsto \zeta t + c$, $\zeta \in
\mu_{\infty}$, or else $\limsup_{n \in \mathbb{N}}
\frac{\log{h_{\mathrm{aff}}(f^nP)}}{\log{n}} \geq 1/r$. This inequality is the
exponential improvement of the trivial lower bound obtained from counting the
points of bounded height in $\mathbb{A}^r(K)$.


title: Quantum pumping induced by disorder in one dimension

abstract:
  The topological property in one dimension (1D) is protected by symmetry.
Based on a concrete model, we show that since a 1D topological model usually
contain two of the three Pauli matrix, the left one automatically become the
protecting symmetry. We study the effect of disorder preserving or breaking the
symmetry and show the nature of symmetry protecting in the 1D topological
phase. Based on the 1D topological model, a stable quantum pumping can be
constructed, which is topologically nontrivial and can be characterized by the
Chern number. By calculating the instantaneous local current we show that an
integer charge is pumped across a periodic chain in a cyclic process. Also on
an open chain, an edge state can be transferred to the other edge by the
quantum pumping. Furthermore we find that not only the quantum pumping is
stable to on-site disorder, but also can be induced by it. These results may be
realized experimentally using quasicrystals.


title: Quantum probes for the spectral properties of a classical environment

abstract:
  We address the use of simple quantum probes for the spectral characterization
of classical noisy environments. In our scheme a qubit interacts with a
classical stochastic field describing environmental noise and is then measured
after a given interaction time in order to estimate the characteristic
parameters of the noise. In particular, we address estimation of the spectral
parameters of two relevant kinds of non-Gaussian noise: random telegraph noise
with Lorentzian spectrum and colored noise with $1/f^{\alpha}$ spectrum. We
discuss the estimation precision achievable by quantum probes by analyzing in
details the behavior of the quantum Fisher information (QFI) as a function of
the noise and the other parameters. We found that population measurement on the
qubit is optimal for noise estimation and also evaluate the optimal interaction
times for the quantum probe, i.e. the values maximizing the QFI and the quantum
signal-to-noise ratio. For random telegraph noise the QFI is inversely
proportional to the square of the switching rate, meaning that the quantum
signal-to-noise ratio is constant and thus the switching rate may be uniformly
estimated with the same precision in its whole range of variation. For colored
noise, the precision achievable in the estimation of ``color'', i.e. of the
exponent $\alpha$, strongly depends on the structure of the environment, i.e.
on the number of fluctuators describing the classical environment. For an
environment modeled by a single random fluctuator estimation is more precise
for pink noise, i.e. for $\alpha=1$, whereas by increasing the number of
fluctuators, the QFI is has two local maxima, with the largest one drifting
towards $\alpha=2$, i.e. brown noise.


title: Validity of covariance models for the analysis of geographical variation

abstract:
  Due to the availability of large molecular data-sets, covariance models are
increasingly used to describe the structure of genetic variation as an
alternative to more heavily parametrised biological models. We focus here on a
class of parametric covariance models that received sustained attention lately
and show that the conditions under which they are valid mathematical models
have been overlooked so far. We provide rigorous results for the construction
of valid covariance models in this family. We also outline how to construct
alternative covariance models for the analysis of geographical variation that
are both mathematically well behaved and easily implementable.


title:
Reconstruction of interfaces from the elastic farfield measurements
  using CGO solutions

abstract:
  In this work, we are concerned with the inverse scattering by interfaces for
the linearized and isotropic elastic model at a fixed frequency. First, we
derive complex geometrical optic solutions with linear or spherical phases
having a computable dominant part and an $H^\alpha$-decaying remainder term
with $\alpha <3$, where $H^{\alpha}$ is the classical Sobolev space. Second,
based on these properties, we estimate the convex hull as well as non convex
parts of the interface using the farfields of only one of the two reflected
body waves (pressure waves or shear waves) as measurements. The results are
given for both the impenetrable obstacles, with traction boundary conditions,
and the penetrable obstacles. In the analysis, we require the surfaces of the
obstacles to be Lipschitz regular and, for the penetrable obstacles, the Lam\'e
coefficients to be measurable and bounded with the usual jump conditions across
the interface.


title: Are polar rings indeed polar?

abstract:
  We have considered polar ring galaxy candidates, the images of which can be
found in the SDSS. The sample of 78 galaxies includes the most reliable
candidates from the SPRC and PRC catalogs, some of which already have kinematic
confirmations. We analyze the distributions of studied objects by the angle
between the polar ring and the central disk, and by the optical diameter of the
outer ring structures. In the vast majority of cases, the outer structures lie
in the plane close to polar (within 10-20 deg) which indicates the stability of
the corresponding orbits in the gravitational potential of the halo. Moderately
inclined outer structures are observed only in about 6% of objects which
probably indicates their short lifetime. In such an unstable configuration, the
polar ring would often cross the disk of the galaxy, being smaller than it in
the diameter. We show that the inner polar structures and outer large-scale
polar rings form a single family in the distribution of diameters normalized to
the optical size of the galaxy. At the same time, this distribution is bimodal,
as the number of objects with d_ring= (0.4-0.7)*d_disk is negligible. Such a
shape of size distribution is most likely due to the fact that the stability of
polar orbits in the inner regions of galaxies is maintained by the bulge or the
bar, while in the outer regions it is provided by the spheroidal (or triaxial)
halo.


title:
First-principle study of octahedral tilting and Ferroelectric like
  transition in metallic LiOsO3

abstract:
  The octahedral tilting and ferroelectric-like structural transition of LiOsO3
metallic perovskite [Nature Materials 12, 1024 (2013)] was examined using
first-principles density-functional theory. In LiOsO3, a-a-a- octahedral
titling mode is responsible for the cubic to rhombohedral structural
transition, which is stable phase at room temperature. At low temperatures, a
non-centrosymmetric transition to a rhombohedra phase was realized due to zone
center phonon softening. The phase transition behavior of LiOsO3 can be
explained fully by density functional calculations and phonon calculations. The
electronic structure and Fermi surface changes due to the electron lattice
coupling effect are also presented. The carrier density of state across the
phase transition is associated with the resistivity, heat capacity, and
susceptibility.


title:
Octahedral tilting and ferroelectricity in RbANb2O7 (A = Bi, Nd) from
  first principles

abstract:
  The effects of octahedral tilting of RbANb2O7 (A = Bi, Nd) compounds was
studied using density-functional theory. In this compound, the structural phase
transition was correlated with two octahedral tilting modes (a-a-c0 tilting and
a0a0c+ tilting), and magnitude of the octahedral tilting mode was analyzed in
the optimized structure. The theoretical results correlated well with the
recent experimental results on the ferroelectricity of RbBiNb2O7. The hybrid
improper ferroelectricity resulting from the coupling of two octahedral tilting
modes and off center displacement mode was analyzed by group theory and
symmetry mode analysis. The detailed relationship of the tilting modes to the
structural phase transition and the detailed physical properties of
ferroelectricity are also presented.


title:
Hamiltonian analysis of curvature-squared gravity with or without
  conformal invariance

abstract:
  We analyze gravitational theories with quadratic curvature terms, including
the case of conformally invariant Weyl gravity, motivated by the intention to
find a renormalizable theory of gravity in the ultraviolet region, yet yielding
general relativity at long distances. In the Hamiltonian formulation of Weyl
gravity, the number of local constraints is equal to the number of unstable
directions in phase space, which in principle could be sufficient for
eliminating the unstable degrees of freedom in the full nonlinear theory. All
the other theories of quadratic type are unstable -- a problem appearing as
ghost modes in the linearized theory.
  We find that the full projection of the Weyl tensor onto a three-dimensional
hypersurface contains an additional fully traceless component, given by a
quadratic extrinsic curvature tensor. A certain inconsistency in the literature
is found and resolved: when the conformal invariance of Weyl gravity is broken
by a cosmological constant term, the theory becomes pathological, since a
constraint required by the Hamiltonian analysis imposes the determinant of the
metric of spacetime to be zero. In order to resolve this problem by restoring
the conformal invariance, we introduce a new scalar field that couples to the
curvature of spacetime, reminiscent of the introduction of vector fields for
ensuring the gauge invariance.


title:
On the inverse elastic scattering by interfaces using one type of
  scattered waves

abstract:
  We deal with the problem of the linearized and isotropic elastic inverse
scattering by interfaces. We prove that the scattered $P$-parts or $S$-parts of
the far field pattern, corresponding to all the incident plane waves of
pressure or shear types, uniquely determine the obstacles for both the
penetrable and impenetrable obstacles. In addition, we state a reconstruction
procedure. In the analysis, we assume only the Lipschitz regularity of the
interfaces and, for the penetrable case, the Lam{\'e} coefficients to be
measurable and bounded, inside the obstacles, with the usual jumps across these
interfaces.


title: The Weierstrass semigroups on double covers of genus two curves

abstract:
  We show that three numerical semigroups <5,6,7,8>, <3,7,8 > and <3,5> are of
double covering type, i.e., the Weierstrass semigroups of ramification points
on double covers of curves. Combining this with the results of
Oliveira-Pimentel and Komeda we can determine the Weierstrass semigroups of the
ramification points on double covers of genus two curves.


title: Left-Right Symmetry and the Charged Higgs Bosons at the LHC

abstract:
  The charged Higgs boson sector of the Minimal Manifest Left-Right Symmetric
model (MLRSM) is investigated in the context of LHC discovery search for new
physics beyond Standard Model. We discuss and summarise the main processes
within MLRSM where heavy charged Higgs bosons can be produced at the LHC. We
explore the scenarios where the amplified signals due to relatively light
charged scalars dominate against heavy neutral $Z_2$ and charged gauge $W_2$ as
well as heavy neutral Higgs bosons signals which are dumped due to large vacuum
expectation value $v_R$ of the right-handed scalar triplet. In particular,
production processes with one and two doubly charged Higgs bosons are
considered. We further incorporate the decays of those scalars leading to multi
lepton signals at the LHC. Branching ratios for heavy neutrino $N_R$, $W_2$ and
$Z_2$ decay into charged Higgs bosons are calculated. These effects are
substantial enough and cannot be neglected. The tri- and four-lepton final
states for different benchmark points are analysed. Kinematic cuts are chosen
in order to strength the leptonic signals and decrease the Standard Model (SM)
background. The results are presented using di-lepton invariant mass and
lepton-lepton separation distributions for the same sign (SSDL) and opposite
sign (OSDL) di-leptons as well as the charge asymmetry are also discussed. We
have found that for considered MLRSM processes tri-lepton and four-lepton
signals are most important for their detection when compared to the SM
background. Both of the signals can be detected at 14 TeV collisions at the LHC
with integrated luminosity at the level of $300 fb^{-1}$ with doubly charged
Higgs bosons up to approximately 600 GeV. Finally, possible extra contribution
of the charged MLRSM scalar particles to the measured Higgs to di-photon
($H_0^0 \to \gamma \gamma$) decay is computed and pointed out.


title:
Derivation of reaction cross sections from experimental elastic
  backscattering probabilities

abstract:
  The relationship between the backward elastic scattering probabilities and
reaction cross sections is derived. This is a a very simple and useful method
to extract reaction cross sections for heavy ion systems. We compare the
results of our method with those using the traditional full elastic scattering
angular distributions, for several systems, at energies near and above the
Coulomb barrier. From the calculated reaction and capture cross sections using
the present method, we derive the cross sections of other mechanisms for nearly
spherical systems.


title: Elliptic Determinantal Process of Type A

abstract:
  We introduce an elliptic extension of Dyson's Brownian motion model, which is
a temporally inhomogeneous diffusion process of noncolliding particles defined
on a circle. Using elliptic determinant evaluations related to the reduced
affine root system of types $A$, we give determinantal martingale
representation (DMR) for the process, when it is started at the configuration
with equidistant spacing on the circle. DMR proves that the process is
determinantal and the spatio-temporal correlation kernel is determined. By
taking temporally homogeneous limits of the present elliptic determinantal
process, trigonometric and hyperbolic versions of noncolliding diffusion
processes are studied.

categories: math.PR cond-mat.stat-mech math-ph math.MP nlin.SI


title: Maximizing the number of independent sets of a fixed size

abstract:
  Let $i_t(G)$ be the number of independent sets of size $t$ in a graph $G$.
Engbers and Galvin asked how large $i_t(G)$ could be in graphs with minimum
degree at least $\delta$. They further conjectured that when $n\geq 2\delta$
and $t\geq 3$, $i_t(G)$ is maximized by the complete bipartite graph
$K_{\delta, n-\delta}$. This conjecture has drawn the attention of many
researchers recently. In this short note, we prove this conjecture.


title:
Some new identities on the Apostol-Bernoulli polynomials of higher order
  derived from Bernoulli basis

abstract:
  In the present paper, we obtain new interesting relations and identities of
the Apostol-Bernoulli polynomials of higher order, which are derived using a
Bernoulli polynomial basis. Finally, by utilizing our method, we also derive
formulas for the convolutions of Bernoulli and Euler polynomials, expressed via
Apostol-Bernoulli polynomials of higher order.


title: Qubit entanglement: A Jordan algebraic perspective

abstract:
  We review work classifying the physically distinct forms of 3-qubit
entanglement using the elegant framework of Jordan algebras, Freudenthal triple
systems and groups of type E_7. While this framework is, in the first instance,
specific to three qubits, it is shown here how the essential features may be
naturally generalised to an arbitrary number of qubits.


title: Towards Big Topic Modeling

abstract:
  To solve the big topic modeling problem, we need to reduce both time and
space complexities of batch latent Dirichlet allocation (LDA) algorithms.
Although parallel LDA algorithms on the multi-processor architecture have low
time and space complexities, their communication costs among processors often
scale linearly with the vocabulary size and the number of topics, leading to a
serious scalability problem. To reduce the communication complexity among
processors for a better scalability, we propose a novel communication-efficient
parallel topic modeling architecture based on power law, which consumes orders
of magnitude less communication time when the number of topics is large. We
combine the proposed communication-efficient parallel architecture with the
online belief propagation (OBP) algorithm referred to as POBP for big topic
modeling tasks. Extensive empirical results confirm that POBP has the following
advantages to solve the big topic modeling problem: 1) high accuracy, 2)
communication-efficient, 3) fast speed, and 4) constant memory usage when
compared with recent state-of-the-art parallel LDA algorithms on the
multi-processor architecture.


title: Lattice-cell : Hybrid approach for text categorization

abstract:
  In this paper, we propose a new text categorization framework based on
Concepts Lattice and cellular automata. In this framework, concept structure
are modeled by a Cellular Automaton for Symbolic Induction (CASI). Our
objective is to reduce time categorization caused by the Concept Lattice. We
examine, by experiments the performance of the proposed approach and compare it
with other algorithms such as Naive Bayes and k nearest neighbors. The results
show performance improvement while reducing time categorization.


title: Nebular metallicities in two isolated Local Void dwarf galaxies

abstract:
  Isolated dwarf galaxies, especially those situated in voids, may provide
insight into primordial conditions in the Universe and the physical processes
that govern star formation in undisturbed stellar systems. The metallicity of H
ii regions in such galaxies is key to investigating this possibility. From the
SIGRID sample of isolated dwarf galaxies, we have identified two exceptionally
isolated objects, the Local Void galaxy [KK98]246 (ESO 461-G036) and another
somewhat larger dwarf irregular on the edge of the Local Void, MCG-01-41-006
(HIPASS J1609- 04). We report our measurements of the nebular metallicities in
these objects. The first object has a single low luminosity Hii region, while
the second is in a more vigorous star forming phase with several bright H ii
regions. We find that the metallicities in both galaxies are typical for
galaxies of this size, and do not indicate the presence of any primordial gas,
despite (for [KK98]246) the known surrounding large reservoir of neutral
Hydrogen.


title: Stable and quasi-stable confining SU(N) strings in D=2+1

abstract:
  We investigate the low-lying spectrum of closed confining flux-tubes that
wind around a spatial torus in D=2+1 and carry flux in different
representations of SU(N). We focus on our most recent calculations for N=6 and
{\beta}=171, where the calculated low-energy physics is very close to the
continuum and large-N limits. We investigate the adjoint, 84, 120, k = 2A, 2S
and k = 3A, 3M, 3S representations and show that the corresponding flux-tubes
do exist. Similarly to the results for the fundamental representation, the
ground state of a flux-tube with momentum along its axis appears to be well
described by Nambu-Goto all the way down to very short tubes. In contrast,
excited states have much larger deviations from Nambu-Goto. We discuss whether
these states are non-string-like and associated with excitations of massive
flux-tube modes.


title: Conditional Expectations of Correspondences

abstract:
  We characterize the properties of convexity, compactness and preservation of
upper hemicontinuity for conditional expectations of correspondences. These
results are then applied to obtain a necessary and sufficient condition for the
existence of pure strategy equilibria in Bayesian games.


title: First results for SU(2) Yang-Mills with one adjoint Dirac Fermion

abstract:
  We present a first exploratory study of SU(2) gauge theory with one Dirac
flavour in the adjoint representation. We provide initial results for the
spectroscopy and the anomalous dimension for the chiral condensate. Our
investigation indicates that the theory is conformal or near-conformal, with an
anomalous dimension of order one. A discussion of the relevance of these
findings in relation to walking technicolor scenarios is also presented.


title: Infinite Tension Limit of the Pure Spinor Superstring

abstract:
  Mason and Skinner recently constructed a chiral infinite tension limit of the
Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan
formulae for tree-level d=10 Yang-Mills amplitudes and the NS-NS sector of
tree-level d=10 supergravity amplitudes. In this letter, their chiral infinite
tension limit is generalized to the pure spinor superstring which computes a
d=10 superspace version of the Cachazo-He-Yuan formulae for tree-level d=10
super-Yang-Mills and supergravity amplitudes.


title:
Fermionic Functional Renormalization Group Approach to Bose-Einstein
  Condensation of Dimers

abstract:
  Fermionic functional renormalization group (f-FRG) is applied to describe
Bose-Einstein condensation (BEC) of dimers for a two-component fermionic system
with attractive contact interaction. In order to describe the system of dimers
without introducing auxiliary bosonic fields (bosonization), we propose a new
exact evolution-equation of the effective action in f-FRG with an infrared
regulator for the fermion vertex. Then we analyze its basic properties in
details. We show explicitly that the critical temperature of the free Bose gas
is obtained naturally by this method without bosonization. Methods to make
systematic improvement from the deep BEC limit are briefly discussed.

categories: cond-mat.quant-gas hep-ph hep-th nucl-th


title:
Unsupervised Learning of Invariant Representations in Hierarchical
  Architectures

abstract:
  The present phase of Machine Learning is characterized by supervised learning
algorithms relying on large sets of labeled examples ($n \to \infty$). The next
phase is likely to focus on algorithms capable of learning from very few
labeled examples ($n \to 1$), like humans seem able to do. We propose an
approach to this problem and describe the underlying theory, based on the
unsupervised, automatic learning of a ``good'' representation for supervised
learning, characterized by small sample complexity ($n$). We consider the case
of visual object recognition though the theory applies to other domains. The
starting point is the conjecture, proved in specific cases, that image
representations which are invariant to translations, scaling and other
transformations can considerably reduce the sample complexity of learning. We
prove that an invariant and unique (discriminative) signature can be computed
for each image patch, $I$, in terms of empirical distributions of the
dot-products between $I$ and a set of templates stored during unsupervised
learning. A module performing filtering and pooling, like the simple and
complex cells described by Hubel and Wiesel, can compute such estimates.
Hierarchical architectures consisting of this basic Hubel-Wiesel moduli inherit
its properties of invariance, stability, and discriminability while capturing
the compositional organization of the visual world in terms of wholes and
parts. The theory extends existing deep learning convolutional architectures
for image and speech recognition. It also suggests that the main computational
goal of the ventral stream of visual cortex is to provide a hierarchical
representation of new objects/images which is invariant to transformations,
stable, and discriminative for recognition---and that this representation may
be continuously learned in an unsupervised way during development and visual
experience.


title: Hadron structure and elastic scattering

abstract:
  When colliding, the high energy hadrons can either produce new particles or
scatter elastically without change of their quantum numbers and other particles
produced. Namely elastic scatterings of hadrons are considered in this paper.
The general machinery of their theoretical treatment is described. Some new
experimental data are presented and confronted to phenomenological approaches.
The internal structure of hadrons is the main subject of these studies. Its
impact on properties of their interactions is reviewed. It is shown that
protons become larger and darker with increase of their collision energy and
reveal some substructure. The violation of the geometric scaling in the
diffraction cone and new problems of description of differential cross sections
outside it are described.


title:
Simulating the Synchronizing Behavior of High-Frequency Trading in
  Multiple Markets

abstract:
  Nearly one-half of all trades in financial markets are executed by
high-speed, autonomous computer programs -- a type of trading often called
high-frequency trading (HFT). Although evidence suggests that HFT increases the
efficiency of markets, it is unclear how or why it produces this outcome. Here
we create a simple model to study the impact of HFT on investors who trade
similar securities in different markets. We show that HFT can improve liquidity
by allowing more transactions to take place without adversely affecting pricing
or volatility. In the model, HFT synchronizes the prices of the securities,
which allows buyers and sellers to find one another across markets and
increases the likelihood of competitive orders being filled.


title: Giant magnetocaloric effect in magnetoelectric Eu1-xBaxTiO3

abstract:
  We report the magnetic entropy change (Delta Sm) in magnetoelectric
Eu1-xBaxTiO3 for x = 0.1- 0.9. We find - delta Sm = 11 (40) J/kg.K in x = 0.1
for a field change of 1 (5) Tesla respectively, which is the largest value
among all Eu-based oxides. Delta Sm arises from the field-induced suppression
of the spin entropy of Eu2+:4f7 localized moments. While -delta Sm decreases
with increasing x, -DeltaSm = 6.58 J/kg.K observed in the high spin diluted
composition x = 0.9 is larger than that in many manganites. Our results
indicate that these magnetoelectrics are potential candidates for cryogenic
magnetic refrigeration.


title: On the quantum graph spectra of graphyne nanotubes

abstract:
  We describe explicitly the dispersion relations and spectra of periodic
Schrodinger operators on a graphyne nanotube structure.


title: Interactive Distributed Detection: Architecture and Performance Analysis

abstract:
  This paper studies the impact of interactive fusion on detection performance
in tandem fusion networks with conditionally independent observations. Within
the Neyman-Pearson framework, two distinct regimes are considered: the fixed
sample size test and the large sample test. For the former, it is established
that interactive distributed detection may strictly outperform the one-way
tandem fusion structure. However, for the large sample regime, it is shown that
interactive fusion has no improvement on the asymptotic performance
characterized by the Kullback-Leibler (KL) distance compared with the simple
one-way tandem fusion. The results are then extended to interactive fusion
systems where the fusion center and the sensor may undergo multiple steps of
memoryless interactions or that involve multiple peripheral sensors, as well as
to interactive fusion with soft sensor outputs.

categories: cs.IT math.IT math.OC math.ST stat.AP stat.TH


title: Long-term variability of AGN at hard X-rays

abstract:
  Variability at all observed wavelengths is a distinctive property of AGN.
Hard X-rays provide us with a view of the innermost regions of AGN, mostly
unbiased by absorption along the line of sight. Swift/BAT offers the unique
opportunity to follow, on time scales of days to years and with a regular
sampling, the 14-195 keV emission of the largest AGN sample available up to
date for this kind of investigation. We study the amplitude of the variations,
and their dependence on sub-class and on energy, for a sample of 110 radio
quiet and radio loud AGN selected from the BAT 58-month survey. About 80% of
the AGN in the sample are found to exhibit significant variability on months to
years time scales, radio loud sources being the most variable. The amplitude of
the variations and their energy dependence are incompatible with variability
being driven at hard X-rays by changes of the absorption column density. In
general, the variations in the 14-24 and 35-100 keV bands are well correlated,
suggesting a common origin of the variability across the BAT energy band.
However, radio quiet AGN display on average 10% larger variations at 14-24 keV
than at 35-100 keV and a softer-when-brighter behavior for most of the Seyfert
galaxies with detectable spectral variability on month time scale. In addition,
sources with harder spectra are found to be more variable than softer ones.
These properties are generally consistent with a variable power law continuum,
in flux and shape, pivoting at energies >~ 50 keV, to which a constant
reflection component is superposed. When the same time scales are considered,
the timing properties of AGN at hard X-rays are comparable to those at lower
energies, with at least some of the differences possibly ascribable to
components contributing differently in the two energy domains (e.g.,
reflection, absorption).


title: Giant magnetothermopower in charge ordered Nd0.75Na0.25MnO3

abstract:
  We report magnetization, resistivity and thermopower in the charge-orbital
ordered antiferromagnet Nd0.75Na0.25MnO3. Magnetic-field induced collapse of
antiferromagnetism is found to be accompanied by a giant negative
magnetothermopower (= 80-100% for a field change of 5T) over a wide temperature
(T = 60-225K) and giant magnetoresistance. While the field-induced metamagnetic
transition in magnetization is reversible upon field-cycling at T > 40 K, it is
irreversible at lower temperatures and this has impact on magnetoresistance,
magnetothermopower as well as change in the temperature of the sample. Our
results indicate high sensitivity of thermopower to changes in the magnetic
state of the sample.


title: A Visibility Graph Averaging Aggregation Operator

abstract:
  The problem of aggregation is considerable importance in many disciplines. In
this paper, a new type of operator called visibility graph averaging (VGA)
aggregation operator is proposed. This proposed operator is based on the
visibility graph which can convert a time series into a graph. The weights are
obtained according to the importance of the data in the visibility graph.
Finally, the VGA operator is used in the analysis of the TAIEX database to
illustrate that it is practical and compared with the classic aggregation
operators, it shows its advantage that it not only implements the aggregation
of the data purely, but also conserves the time information, and meanwhile, the
determination of the weights is more reasonable.


title: Towards Hybrid Artificial-Slime Mould Devices

abstract:
  The plasmodium of the slime mould Physarum polycephalum has recently received
significant attention for its value as a highly malleable amorphous computing
substrate. In laboratory-based experiments, micro- and nanoscale artificial
circuit components were introduced into the P. polycephalum plasmdodium to
investigate the electrical properties and computational abilities of hybridised
slime mould. It was found through a combination of imaging techniques and
electrophysiological measurements that P. polycephalum is able to internalise a
range of electrically active nanoparticles, assemble them in vivo and
distribute them around the plasmodium. Hybridised plasmodium is able to form
biomorphic mineralised networks, both inside the living plasmodium and the
empty trails left in its wake by taxis, both of which facilitate the
transmission of electricity. Hybridisation also alters the bioelectrical
activity of the plasmodium and likely influences its information processing
capabilities. It was concluded that hybridised slime mould is a suitable
substrate for producing functional unconventional computing devices.