title: 4-dimensional compact manifolds with nonnegative biorthogonal curvature

abstract:
  The goal of this article is to study the pinching problem proposed by S.-T.
Yau in 1990 replacing sectional curvature by one weaker condition on
biorthogonal curvature. Moreover, we classify 4-dimensional compact oriented
Riemannian manifolds with nonnegative biorthogonal curvature. In particular, we
obtain a partial answer to Yau Conjecture on pinching theorem for 4-dimensional
compact manifolds.


title: The Science and Beauty of Fluidization

abstract:
  Particle flows of high particle concentration are important in many fields,
including chemical processing, pharmaceutical processing, energy conversion and
powder transport. However, despite decades of research and industrial
application, the real time behavior of particle flow fields is still not well
understood. One of the main reasons is that experimental data is difficult to
acquire in such harsh, opaque particle flow environments. In this educational
video for the Gallery of Fluid Motion, high speed video acquired with a new,
patented high speed particle imaging velocimetry (high speed PIV) technology is
presented. This technology was developed by the USDOE National Energy
Technology Laboratory (NETL). It is being applied to observe and measure the
real time behavior of individual particle motion inside particle flow fields of
high particle concentration for the first time. The high speed PIV system
records high speed videos of particle motion with excellent spatial and
temporal clarity. The high speed videos are analyzed to measure the
concentration and the two-dimensional motion (velocity and trajectory) of
individual particles. Data sample rates for velocity vectors are in the range
of 0.1 to 3 million vectors per second, thereby providing full resolution of
the temporal domain of particle velocity. To see and measure particle motion
inside the flow fields at high particle concentrations, a custom borescope is
inserted into particle flow fields.
  The particle tracking technique can measure gas and fluid flow if the
particles are small enough (have a low enough Stokes number) to follow the
gas/fluid flow. In areas of rapid mixing, such as turbulent wakes, particle
tracking can provide better spatial resolution that conventional
cross-correlation based PIV analysis.
  Keywords: fluid dynamics video, particle tracking, fluidization


title: Primordial fluctuations from deformed quantum algebras

abstract:
  We study the implications of deformed quantum algebras for the generation of
primordial perturbations from slow-roll inflation. Specifically, we assume that
the quantum commutator of the inflaton's amplitude and momentum in Fourier
space gets modified at energies above some threshold $M_{\star}$. We show that
when the commutator is modified to be a function of the momentum only, the
problem of solving for the post-inflationary spectrum of fluctuations is
formally equivalent to solving a one-dimensional Schr\"odinger equation with a
time dependent potential. Depending on the class of modification, we find
results either close to or significantly different from nearly scale invariant
spectra. For the former case, the power spectrum is characterized by step-like
behaviour at some pivot scale, where the magnitude of the jump is
$\mathcal{O}(H^{2}/M_{\star}^{2})$. ($H$ is the inflationary Hubble parameter.)
We use our calculated power spectra to generate predictions for the cosmic
microwave background and baryon acoustic oscillations, hence demonstrating that
certain types of deformations are incompatible with current observations.


title:
A two-type Bellman--Harris process initiated by a large number of
  particles

abstract:
  We investigate a two-type critical Bellman--Harris branching process with the
following properties: the tail of the life-length distribution of the first
type particles is of order $o(t^{-2})$; the tail of the life-length
distribution of the second type particles is regularly varying at infinity with
index $-\beta$, $\beta \in (0,1]$; at time $t=0$ the process starts with a
large number $N$ of the second type particles and no particles of the first
type. It is shown that the time axis $0\leq t<\infty $ splits into several
regions whose ranges depend on $\beta $ and the ratio $N/t$ within each of
which the process at time $t$ exhibits asymptotics (as $N,t\rightarrow \infty$)
which is different from those in the other regions.


title:
Pathwise stability of likelihood estimators for diffusions via rough
  paths

abstract:
  We consider the classical estimation problem of an unknown drift parameter
within classes of nondegenerate diffusion processes. Using rough path theory
(in the sense of T. Lyons), we analyze the Maximum Likelihood Estimator (MLE)
with regard to its pathwise stability properties as well as robustness toward
misspecification in volatility and even the very nature of the noise. Two
numerical examples demonstrate the practical relevance of our results.


title: On the largest graph-Lagrangians of hypergraphs

abstract:
  Frankl and F\"uredi (1989) conjectured that the $r$-graph with $m$ edges
formed by taking the first $m$ sets in the colex ordering of ${\mathbb
N}^{(r)}$ has the largest graph-Lagrangian of all $r$-graphs with $m$ edges. In
this paper, we establish some bounds for graph-Lagrangians of some special
$r$-graphs that support this conjecture.


title:
Optimal control of semi-Markov processes with a backward stochastic
  differential equations approach

abstract:
  In the present work we employ, for the first time, backward stochastic
differential equations (BSDEs) to study the optimal control of semi-Markov
processes on finite horizon, with general state and action spaces. More
precisely, we prove that the value function and the optimal control law can be
represented by means of the solution of a class of BSDEs driven by a
semi-Markov process or, equivalently, by the associated random measure. The
peculiarity of the semi-Markov framework, with respect to the pure jump Markov
case, consists in the proof of the relation between BSDE and optimal control
problem. This is done, as usual, via the Hamilton-Jacobi-Bellman (HJB)
equation, which however in the semi-Markov case is characterized by an
additional differential term $\partial_a$. Taking into account the particular
structure of semi-Markov processes we rewrite the HJB equation in a suitable
integral form which involves a directional derivative operator $D$ related to
$\partial_a$. Then, using a formula of Ito type tailor-made for semi-Markov
processes and the operator $D$, we are able to prove that the BSDE provides the
unique classical solution to the HJB equation, which is shown to be the value
function of our control problem.


title: Noetherian Leavitt path algebras and their regular algebras

abstract:
  In the past, it has been shown that the Leavitt path algebra $L(E)=L_K(E)$ of
a graph $E$ over a field $K$ is left and right noetherian if and only if the
graph $E$ is finite and no cycle of $E$ has an exit. If $Q(E)=Q_K(E)$ denotes
the regular algebra over $L(E),$ we prove that these conditions are further
equivalent with any of the following: $L(E)$ contains no infinite set of
orthogonal idempotents, $L(E)$ has finite uniform dimension, $L(E)$ is directly
finite, $Q(E)$ is directly finite, $Q(E)$ is unit-regular, and a few more
equivalences. In addition, if the involution on $K$ is positive definite, these
conditions are equivalent with the following: the involution $^\ast$ extends
from $L(E)$ to $Q(E),$ $Q(E)$ is $^\ast$-regular, $Q(E)$ is finite, $Q(E)$ is
the maximal (total or classical) symmetric ring of quotients of $L(E),$ every
finitely generated nonsingular $L(E)$-module is projective, and the matrix ring
$M_n(L(E))$ is strongly Baer for every $n$. It may not be surprising that a
noetherian Leavitt path algebra has these properties, but a more interesting
fact is that these properties hold only if a Leavitt path algebra is
noetherian.
  Using some of these equivalences, we give a specific description of the
inverse of the isomorphism $V(L(E))\rightarrow V(Q(E))$ of monoids of
equivalence classes of finitely generated projective modules for noetherian
Leavitt path algebras. We also prove that two noetherian Leavitt path algebras
are isomorphic as rings if and only if they are isomorphic as $^\ast$-algebras.
This answers in affirmative the Isomorphism Conjecture for the class of
noetherian Leavitt path algebras: if $L_{\mathbb C}(E)$ and $L_{\mathbb C}(F)$
are noetherian Leavitt path algebras, then $L_{\mathbb C}(E)\cong L_{\mathbb
C}(F)$ as rings implies $C^*(E)\cong C^*(F)$ as $^\ast$-algebras.


title:
Light-by-Light Scattering Nonlogarithmic Corrections to Hyperfine
  Splitting in Muonium

abstract:
  We consider three-loop corrections to hyperfine splitting in muonium
generated by the gauge invariant set of diagrams with virtual light-by-light
scattering block. These diagrams produce both recoil and nonrecoil
contributions to hyperfine splitting. Recoil corrections are enhanced by large
logarithms of the muon-electron mass ratio. Both nonrecoil and logarithmically
enhanced radiative-recoil corrections where calculated some time ago. Here we
calculate nonlogarithmic radiative-recoil corrections generated by the
insertions of the light-by-light scattering block.


title:
The scalar mesons in multi-channel $\pi\pi$ scattering and decays of the
  $\psi$ and $\Upsilon$ families

abstract:
  The $f_0$ mesons are studied in a combined analysis of data on the isoscalar
S-wave processes $\pi\pi\to\pi\pi,K\overline{K},\eta\eta$ and on decays
$J/\psi\to\phi(\pi\pi, K\overline{K})$, $\psi(2S)\to J/\psi(\pi\pi)$, and
$\Upsilon(2S)\to\Upsilon(1S)\pi\pi$ from the Argus, Crystal Ball, CLEO, CUSB,
DM2, Mark II, Mark III, and BES II collaborations. The method of analysis,
based on analyticity and unitarity and using an uniformization procedure, is
set forth with some details. Some spectroscopic implications from results of
the analysis are discussed.


title: Approximation of improper priors

abstract:
  We propose a convergence mode for positive Radon measures which allows a
sequence of probability measures to have an improper limiting measure. We
define a sequence of vague priors as a sequence of probability measures that
converges to an improper prior. We consider some cases where vague priors have
necessarily large variances and other cases where they have not. We study the
consequences of the convergence of prior distributions on the posterior
analysis. Then we give some constructions of vague priors that approximate the
Haar measures or the Jeffreys priors. We also revisit the Jeffreys-Lindley
paradox.


title:
Possible very high transition temperatures in the infinite-layer ACuO$
  _{2} $ cuprate superconductor for A={Mg, Ca, Sr, Ba}: A DFT study

abstract:
  We show from a bond valence sum correlation that very high superconducting $
T_{c} $ values should be found in optimally hole-doped infinite-layer ACuO$
_{2} $ cuprates - up to 160~K for A = Ba. The projected increase in $ T_{c} $
across the series arises from "internal pressure" effects as A runs from Mg to
Ba. We then use density functional theory to investigate these pressure effects
on the band structure in an attempt to understand this progressive increase in
$ T_{c} $. Where these materials have been synthesised we find good agreement
between our calculated structural parameters and the experimental ones. We find
that internal pressure associated with increasing ion size does indeed enhance
the superconducting energy gap, as observed, via modifications to the
electronic dispersion. Furthermore, in our calculations, pressure alters the
dispersion independently of how it is applied (internal or external) so that
the superconducting energy gap correlates with the unit-cell volume and a
Fermi-surface shape-parameter describing ratio of next-nearest-neighbor to
nearest-neighbor hopping integrals. We infer an energy scale for the pairing
interaction of the order of 1~eV, well above the magnetic energy scale.


title:
Exact predictions from Edwards ensemble vs. realistic simulations of
  tapped narrow two-dimensional granular columns

abstract:
  We simulate via a Discrete Element Method the tapping of a narrow column of
disk under gravity. For frictionless disks, this system has a simple analytic
expression for the density of states in the Edwards volume ensemble. We compare
the predictions of the ensemble at constant compactivity against the results
for the steady states obtained in the simulations. We show that the steady
states cannot be properly described since the microstates sampled are not in
correspondence with the predicted distributions, suggesting that the postulates
of flat measure and ergodicity are, either or both, invalid for this simple
realization of a static granular system. However, we show that certain
qualitative features of the volume fluctuations difficult to predict from
simple arguments are captured by the theory.


title: KROME - a package to embed chemistry in astrophysical simulations

abstract:
  Chemistry plays a key role in many astrophysical situations regulating the
cooling and the thermal properties of the gas, which are relevant during
gravitational collapse, the evolution of disks and the fragmentation process.
  In order to simplify the usage of chemical networks in large numerical
simulations, we present the chemistry package KROME, consisting of a Python
pre-processor which generates a subroutine for the solution of chemical
networks which can be embedded in any numerical code. For the solution of the
rate equations, we make use of the high-order solver DLSODES, which was shown
to be both accurate and efficient for sparse networks, which are typical in
astrophysical applications. KROME also provides a large set of physical
processes connected to chemistry, including photochemistry, cooling, heating,
dust treatment, and reverse kinetics.
  The package presented here already contains a network for primordial
chemistry, a small metal network appropriate for the modelling of low
metallicities environments, a detailed network for the modelling of molecular
clouds, a network for planetary atmospheres, as well as a framework for the
modelling of the dust grain population. In this paper, we present an extended
test suite ranging from one-zone and 1D-models to first applications including
cosmological simulations with ENZO and RAMSES and 3D collapse simulations with
the FLASH code. The package presented here is publicly available at
http://kromepackage.org/ and https://bitbucket.org/krome/krome_stable


title:
Imaginary Time Correlations and the phaseless Auxiliary Field Quantum
  Monte Carlo

abstract:
  The phaseless Auxiliary Field Quantum Monte Carlo method provides a well
established approximation scheme for accurate calculations of ground state
energies of many-fermions systems. Here we apply the method to the calculation
of imaginary time correlation functions. We give a detailed description of the
technique and we test the quality of the results for static and dynamic
properties against exact values for small systems.


title:
Abundances of lithium, oxygen, and sodium in the turn-off stars of
  Galactic globular cluster 47 Tuc

abstract:
  We aim to determine abundances of Li, O and Na in a sample of of 110 turn-off
(TO) stars, in order to study the evolution of light elements in this cluster
and to put our results in perspective with observations of other globular and
open clusters, as well as with field stars. We use medium resolution spectra
obtained with the GIRAFFE spectrograph at the ESO 8.2m Kueyen VLT telescope and
use state of the art 1D model atmospheres and NLTE line transfer to determine
the abundances. We also employ CO5BOLD hydrodynamical simulations to assess the
impact of stellar granulation on the line formation and inferred abundances.
Our results confirm the existence of Na-O abundance anti-correlation and hint
towards a possible Li-O anti-correlation in the TO stars of 47 Tuc. We find no
convincing evidence supporting the existence of Li-Na correlation. The obtained
3D NLTE mean lithium abundance in a sample of 94 TO stars where Li lines were
detected reliably, $\langle A({\rm Li})_{\rm 3D~NLTE}\rangle = 1.78 \pm 0.18$
dex, appears to be significantly lower than what is observed in other globular
clusters. At the same time, star-to-star spread in Li abundance is also larger
than seen in other clusters. The highest Li abundance observed in 47 Tuc is
about 0.1 dex lower than the lowest Li abundance observed among the un-depleted
stars of the metal-poor open cluster NGC 2243. The lithium abundances in 47
Tuc, when put into context with observations in other clusters and field stars,
suggest that stars that are more metal-rich than [FeH] \sim -1.0 experience
significant lithium depletion during their lifetime on the main sequence, while
the more metal-poor stars do not. Rather strikingly, our results suggest that
initial lithium abundance with which the star was created may only depend on
its age (the younger the star, the higher its Li content) and not on its
metallicity.


title:
How linear surface waves are affected by a current with constant
  vorticity

abstract:
  The interaction of surface waves with Couette-type current with uniform
vorticity is a well suited problem for students approaching the theory of
surface waves. The problem, although mathematically simple, contains rich
physics, and is moreover important in several situations from oceanography and
marine technology to microfluidics. We here lay out a simple two-dimensional
theory of waves propagating upon a basic flow of uniform vorticity of constant
depth. The dispersion relation is found, showing how the shearing current
introduces different phase velocities for upstream and downstream propagating
waves. The role of surface tension is discussed and applied to the case of a
wave pattern created by a moving source, stationary as seen by the source. We
conclude by discussing how the average potential and kinetic energies are no
longer equal in the presence of shear.


title:
Repeat-Until-Success: Non-deterministic decomposition of single-qubit
  unitaries

abstract:
  We present a decomposition technique that uses non-deterministic circuits to
approximate an arbitrary single-qubit unitary to within distance $\epsilon$ and
requires significantly fewer non-Clifford gates than existing techniques. We
develop "Repeat-Until-Success" (RUS) circuits and characterize unitaries that
can be exactly represented as an RUS circuit. Our RUS circuits operate by
conditioning on a given measurement outcome and using only a small number of
non-Clifford gates and ancilla qubits. We construct an algorithm based on RUS
circuits that approximates an arbitrary single-qubit $Z$-axis rotation to
within distance $\epsilon$, where the number of $T$ gates scales as
$1.26\log_2(1/\epsilon) - 3.53$, an improvement of roughly three-fold over
state-of-the-art techniques. We then extend our algorithm and show that a
scaling of $2.4\log_2(1/\epsilon) - 3.28$ can be achieved for arbitrary
unitaries and a small range of $\epsilon$, which is roughly twice as good as
optimal deterministic decomposition methods.


title:
Lie algebra generated by locally nilpotent derivations on Danielewski
  surfaces

abstract:
  We give a full description of the Lie algebra generated by locally nilpotent
derivations (short LNDs) on smooth Danielewski surfaces $D_p$ given by
$xy=p(z)$. In case $\mathrm{deg}(p)\geq 3$ it turns out to be not the whole Lie
algebra $\mathrm{VF}_{alg}^\omega(D_p)$ of volume preserving algebraic vector
fields, thus answering a question posed by Lind and the first author. Also we
show algebraic volume density property (short AVDP) for a certain homology
plane, a homogeneous space of the form $SL_2 (\mathbb{C}) /N$, where $N$ is the
normalizer of the maximal torus and another related example. At the end of the
paper we show by example that for the group of holomorphic automorphisms of a
Stein manifold (endowed with c.-o. topology) the connected component and the
path-connected component of the identity may not coincide.


title: Report of the Quark Flavor Physics Working Group

abstract:
  This report represents the response of the Intensity Frontier Quark Flavor
Physics Working Group to the Snowmass charge. We summarize the current status
of quark flavor physics and identify many exciting future opportunities for
studying the properties of strange, charm, and bottom quarks. The ability of
these studies to reveal the effects of new physics at high mass scales make
them an essential ingredient in a well-balanced experimental particle physics
program.


title: The scalar Singlet-Triplet Dark Matter Model

abstract:
  We consider a model for cold dark matter, which combines a real scalar
singlet and a real scalar $SU(2)_L$ triplet field, both of which are residing
in the odd representation of a global $Z_2$ symmetry. The parameter space of
the model is constrained by the inferred dark matter abundance from the WMAP
and Planck data, the most recent results from the direct dark matter search
experiment LUX, the Z boson decay width from LEP-I and perturbativity of the
coupling parameters. The phenomenology of the remaining parameter space is
studied. We find that the model allows for DM masses near the electroweak scale
and a variety of decay scenarios.


title: The hadronic vacuum polarization with twisted boundary conditions

abstract:
  The leading-order hadronic contribution to the anomalous magnetic moment of
the muon is given by a weighted integral over the subtracted hadronic vacuum
polarization. This integral is dominated by euclidean momenta of order the muon
mass which are not available on current lattice volumes with periodic boundary
conditions. Twisted boundary conditions can in principle help access momenta of
any size even in a finite volume. We investigate the implementation of twisted
boundary conditions both numerically (using all-mode averaging for improved
statistics) and analytically, and present our initial results.


title: Exciton-exciton annihilation in MoSe2 monolayers

abstract:
  We investigate the excitonic dynamics in MoSe2 monolayer and bulk samples by
femtosecond transient absorption microscopy. Excitons are resonantly injected
by a 750-nm and 100-fs laser pulse, and are detected by a probe pulse tuned in
the range of 790 - 820 nm. We observe a strong density-dependent initial decay
of the exciton population in monolayers, which can be well described by the
exciton-exciton annihilation. Such a feature is not observed in the bulk under
comparable conditions. We also observe the saturated absorption induced by
exciton phase-space filling in both monolayers and the bulk, which indicates
their potential applications as saturable absorbers.


title:
Quantum phase transitions and ground-state correlations in BCS-like
  models

abstract:
  We study ground-state correlation functions in one- and two-dimensional
lattice models of interacting spinful fermions - BCS-like models, which exhibit
continuous quantum phase transitions. The considered models originate from a
two-dimensional model of d-wave superconductivity proposed by Sachdev. Due to
the exact diagonalizability of the considered models in any dimensionality,
exact phase diagrams, with several kinds of quantum-critical points, are
constructed and closed-form analytic expressions for two-point correlation
functions are obtained. In one- and two-dimensional cases we provide analytic
expressions for the asymptotic behavior of those correlation functions at large
distances and in neighborhoods of quantum-critical points. The novelty of our
results is that in two-dimensions explicit expressions for direction-dependent
correlation lengths in terms of model parameters and the values of
direction-dependent universal critical indices $\nu$, that characterize the
divergence of correlation lengths on approaching critical points, are
determined. Moreover, specific scaling properties of correlation functions with
respect to parameters of underlying Hamiltonians are revealed. Besides
enriching the knowledge of properties of lattice fermion systems exhibiting
continuous quantum phase transitions, especially in two dimensions, our results
open new possibilities of testing unconventional methods of studying quantum
phase transitions, as the promising fidelity approach or the entanglement
approach, beyond one-dimension and beyond the realm of paradigmatic XY and
Ising chains in transverse magnetic fields.


title: Brans-Dicke theory in the local potential approximation

abstract:
  We study the Brans-Dicke theory with arbitrary potential within a functional
renormalization group framework. Motivated by the asymptotic safety scenario of
quantum gravity and by the well-known relation between f(R) gravity and
Brans-Dicke theory at the classical level, we concentrate our analysis on the
fixed-point equation for the potential in four dimensions and with Brans-Dicke
parameter omega equal to zero. For two different choices of gauge, we study the
resulting equations by examining both local and global properties of the
solutions, by means of analytical and numerical methods. As a result of our
analysis we do not find any nontrivial fixed point in one gauge, but we find a
continuum of fixed points in the other one. We interpret such inconsistency as
a result of the restriction to omega equal to zero, and thus we suggest that it
indicates a failure of the equivalence between f(R) gravity and Brans-Dicke
theory at the quantum level.


title: Motivation for hyperlink creation using inter-page relationships

abstract:
  Using raw hyperlink counts for webometrics research has been shown to be
unreliable and researchers have looked for alternatives. One alternative is
classifying hyperlinks in a website based on the motivation behind the
hyperlink creation. The method used for this type of classification involves
manually visiting a webpage and then classifying individual links on the
webpage. This is time consuming, making it infeasible for large scale studies.
This paper speeds up the classification of hyperlinks in UK academic websites
by using a machine learning technique, decision tree induction, to group web
pages found in UK academic websites into one of eight categories and then infer
the motivation for the creation of a hyperlink in a webpage based on the
linking pattern of the category the webpage belongs to.


title:
An Efficient Method for Image and Audio Steganography using Least
  Significant Bit (LSB) Substitution

abstract:
  In order to improve the data hiding in all types of multimedia data formats
such as image and audio and to make hidden message imperceptible, a novel
method for steganography is introduced in this paper. It is based on Least
Significant Bit (LSB) manipulation and inclusion of redundant noise as secret
key in the message. This method is applied to data hiding in images. For data
hiding in audio, Discrete Cosine Transform (DCT) and Discrete Wavelet Transform
(DWT) both are used. All the results displayed prove to be time-efficient and
effective. Also the algorithm is tested for various numbers of bits. For those
values of bits, Mean Square Error (MSE) and Peak-Signal-to-Noise-Ratio (PSNR)
are calculated and plotted. Experimental results show that the stego-image is
visually indistinguishable from the original cover-image when n<=4, because of
better PSNR which is achieved by this technique. The final results obtained
after steganography process does not reveal presence of any hidden message,
thus qualifying the criteria of imperceptible message.


title:
A Chemistry-Inspired Framework for Achieving Consensus in Wireless
  Sensor Networks

abstract:
  The aim of this paper is to show how simple interaction mechanisms, inspired
by chemical systems, can provide the basic tools to design and analyze a
mathematical model for achieving consensus in wireless sensor networks,
characterized by balanced directed graphs. The convergence and stability of the
model are first proven by using new mathematical tools, which are borrowed
directly from chemical theory, and then validated by means of simulation
results, for different network topologies and number of sensors. The underlying
chemical theory is also used to derive simple interaction rules that may
account for practical issues, such as the estimation of the number of neighbors
and the robustness against perturbations. Finally, the proposed chemical
solution is validated under real-world conditions by means of a four-node
hardware implementation where the exchange of information among nodes takes
place in a distributed manner (with no need for any admission control and
synchronism procedure), simply relying on the transmission of a pulse whose
rate is proportional to the state of each sensor.


title: Khovanov homology and the symmetry group of a knot

abstract:
  We introduce an invariant of tangles in Khovanov homology by considering a
natural inverse system of Khovanov homology groups. As application, we derive
an invariant of strongly invertible knots; this invariant takes the form of a
graded vector space that vanishes if and only if the strongly invertible knot
is trivial. While closely tied to Khovanov homology -- and hence the Jones
polynomial -- we observe that this new invariant detects non-amphicheirality in
subtle cases where Khovanov homology fails to do so. In fact, we exhibit
examples of knots that are not distinguished by Khovanov homology but, owing to
the presence of a strong inversion, may be distinguished using our invariant.
This work suggests a strengthened relationship between Khovanov homology and
Heegaard Floer homology by way of two-fold branched covers that we formulate in
a series of conjectures.


title: Tunable transport with broken space-time symmetries

abstract:
  Transport properties of particles and waves in spatially periodic structures
that are driven by external time-dependent forces manifestly depend on the
space-time symmetries of the corresponding equations of motion. A systematic
analysis of these symmetries uncovers the conditions necessary for obtaining
directed transport. In this work we give a unified introduction into the
symmetry analysis and demonstrate its action on the motion in one-dimensional
periodic, both in time and space, potentials. We further generalize the
analysis to quasi-periodic drivings, higher space dimensions, and quantum
dynamics. Recent experimental results on the transport of cold and ultracold
atomic ensembles in ac-driven optical potentials are reviewed as illustrations
of theoretical considerations.


title: The quark-hadron thermodynamics in magnetic field

abstract:
  Nonperturbative treatment of quark-hadron transition at nonzero temperature T
and chemical potential mu in the framework of Field Correlator Method is
generalized to the case of nonzero magnetic field B. A compact form of the
quark pressure for arbitrary B, mu, T is derived. As a result the transition
temperature is found as a function of B and mu, which depends on only
parameters: vacuum gluonic condensate G_2 and the field correlator D_1^E(x),
which defines the Polyakov loops and it is known both analytically and on the
lattice. A moderate (25%) decrease of T_c(mu=0) for eB changing from zero to 1
GeV^2 is found. A sequence of transition curves in the (mu, T) plane is
obtained for B in the same interval, monotonically decreasing in scale for
growing B.


title:
Observation and applications of single-electron charge signals in the
  XENON100 experiment

abstract:
  The XENON100 dark matter experiment uses liquid xenon in a time projection
chamber (TPC) to measure xenon nuclear recoils resulting from the scattering of
dark matter Weakly Interacting Massive Particles (WIMPs). In this paper, we
report the observation of single-electron charge signals which are not related
to WIMP interactions. These signals, which show the excellent sensitivity of
the detector to small charge signals, are explained as being due to the
photoionization of impurities in the liquid xenon and of the metal components
inside the TPC. They are used as a unique calibration source to characterize
the detector. We explain how we can infer crucial parameters for the XENON100
experiment: the secondary-scintillation gain, the extraction yield from the
liquid to the gas phase and the electron drift velocity.


title:
Road Accident Prevention Unit: An prototyping approach towards
  mitigating an omnipresent threat

abstract:
  An intelligent multisensor front end based on the ARM Cortex M3. It deduces a
driver's configuration, ascertains his ability to drive safely and contacts
near ones with location data for urgent disaster mitigation. Prevention
measures are undertaken through external display modules and provision for
being vehicle-powered through external voltage regulated supplies. The proof of
concept for this paper is an ALL INDIA THIRD PRIZE WINNER at the Texas
Instruments Analog Design Contest 2012-13 National Finals and this paper is due
for digital publication in IEEE Xplore. All documentation is property of Texas
Instruments, the Texas Instruments Analog Design Contest 2012-13 and IEEE
Xplore.


title: Polyhedrons and Perceptrons Are Functionally Equivalent

abstract:
  Mathematical definitions of polyhedrons and perceptron networks are
discussed. The formalization of polyhedrons is done in a rather traditional
way. For networks, previously proposed systems are developed. Perceptron
networks in disjunctive normal form (DNF) and conjunctive normal forms (CNF)
are introduced. The main theme is that single output perceptron neural networks
and characteristic functions of polyhedrons are one and the same class of
functions. A rigorous formulation and proof that three layers suffice is
obtained. The various constructions and results are among several steps
required for algorithms that replace incremental and statistical learning with
more efficient, direct and exact geometric methods for calculation of
perceptron architecture and weights.


title: The power of 2 choices over preferential attachment

abstract:
  We introduce a new type of preferential attachment tree that includes choices
in its evolution, like with Achlioptas processes. At each step in the growth of
the graph, a new vertex is introduced. Two possible neighbor vertices are
selected independently and with probability proportional to degree. Between the
two, the vertex with smaller degree is chosen, and a new edge is created. We
determine with high probability the largest degree of this graph up to some
additive error term.


title: Stable Extensions with(out) Gravity

abstract:
  We investigate the vacuum stability as well as the gravitational corrections
in extensions of the Standard Model featuring a new complex scalar, and two
Dirac fermions for different choices of the hypercharge of the scalar and one
of the two fermions. The neutral fermion acquires loop-induced magnetic
interactions with the Standard Model and could be identified with a dark matter
candidate. To the lowest order in perturbation theory we show that these
extensions can save the electroweak vacuum from being metastable. We then add
the gravitational corrections to the different beta functions and discover that
the models can be compatible with the asymptotically safe gravity scenario at
the price of a heavier Higgs and lighter top mass.


title: The origin of the logarithmic integral in the prime number theorem

abstract:
  We establish why li(x) outperforms x/log x as an estimate for the prime
counting function pi(x). The result follows from subdividing the natural
numbers into the intervals s_k :={p_k^2,..., p_{k+1}^2-1}, k>=1, each being
fully sieved by the k first primes {p_1,..., p_k}. Denoting the number of
primes in s_k by pi_k, we show that pi_k |s_k|/log p_{k+1}^2 and that pi(x)
li(x) originates as a continuum approximation of the sum sum_k pi_k. In
contrast, pi(x) x/log x stems from sieving repeatedly in regions already
completed---explaining why x/log x underestimates pi(x). The explanatory
potential arising from defining s_k appears promising, evidenced in the last
section where we outline further research.


title:
Neutron total cross section measurements of gold and tantalum at the
  nELBE photoneutron source

abstract:
  Neutron total cross sections of $^{197}$Au and $^\text{nat}$Ta have been
measured at the nELBE photoneutron source in the energy range from 0.1 - 10 MeV
with a statistical uncertainty of up to 2 % and a total systematic uncertainty
of 1 %. This facility is optimized for the fast neutron energy range and
combines an excellent time structure of the neutron pulses (electron bunch
width 5 ps) with a short flight path of 7 m. Because of the low instantaneous
neutron flux transmission measurements of neutron total cross sections are
possible, that exhibit very different beam and background conditions than found
at other neutron sources.


title: Universal decoherence due to gravitational time dilation

abstract:
  The physics of low-energy quantum systems is usually studied without explicit
consideration of the background spacetime. Phenomena inherent to quantum theory
on curved space-time, such as Hawking radiation, are typically assumed to be
only relevant at extreme physical conditions: at high energies and in strong
gravitational fields. Here we consider low-energy quantum mechanics in the
presence of gravitational time dilation and show that the latter leads to
decoherence of quantum superpositions. Time dilation induces a universal
coupling between internal degrees of freedom and the centre-of-mass of a
composite particle. The resulting correlations cause decoherence of the
particle's position, even without any external environment. We also show that
the weak time dilation on Earth is already sufficient to decohere micron scale
objects. Gravity therefore can account for the emergence of classicality and
the effect can in principle be tested in future matter wave experiments.


title:
Revisiting Dynamics Near a Liquid-Liquid Phase Transition in Si and Ga:
  The Fragile-to-Strong Transition

abstract:
  Using molecular dynamics simulations we analyze the dynamics of two atomic
liquids that display a liquid-liquid phase transition (LLPT): Si described by
the Stillinger-Weber potential and Ga as modeled by the modified embedded-atom
model (MEAM). In particular, our objective is to investigate the extent to
which the presence of a dip in the self-intermediate scattering function is a
manifestation of an excess of vibrational states at low frequencies and may be
associated with a fragile-to-strong transition (FTST) across the LLPT, as
suggested recently. Our results do not lend support to these suggestions.
Specifically, in the case of Ga we observe the appearance of an excess of
vibrational states at low frequencies, even in the absence of the appearance of
a dip in the self-intermediate scattering function across the LLPT.
Furthermore, studying the behavior of the shear viscosities traversing the
LLPTs we find that, despite the development of a dip in the self-intermediate
scattering function for the case of Si and its absence in Ga, both substances
are fragile in character above and below their respective LLPT temperatures.


title: Does Banque de France control inflation and unemployment?

abstract:
  We re-estimate statistical properties and predictive power of a set of
Phillips curves, which are expressed as linear and lagged relationships between
the rates of inflation, unemployment, and change in labour force. For France,
several relationships were estimated eight years ago. The change rate of labour
force was used as a driving force of inflation and unemployment within the
Phillips curve framework. The set of nested models starts with a simplistic
version without autoregressive terms and one lagged term of explanatory
variable. The lag is determined empirically together with all coefficients. The
model is estimated using the Boundary Element Method (BEM) with the least
squares method applied to the integral solutions of the differential equations.
All models include one structural break might be associated with revisions to
definitions and measurement procedures in the 1980s and 1990s as well as with
the change in monetary policy in 1994-1995. For the GDP deflator, our original
model provided a root mean squared forecast error (RMSFE) of 1.0% per year at a
four-year horizon for the period between 1971 and 2004. The rate of CPI
inflation is predicted with RMSFE=1.5% per year. For the naive (no change)
forecast, RMSFE at the same time horizon is 2.95% and 3.3% per year,
respectively. Our model outperforms the naive one by a factor of 2 to 3. The
relationships for inflation were successfully tested for cointegration. We have
formally estimated several vector error correction (VEC) models for two
measures of inflation. At a four year horizon, the estimated VECMs provide
significant statistical improvements on the results obtained by the BEM:
RMSFE=0.8% per year for the GDP deflator and ~1.2% per year for CPI. For a two
year horizon, the VECMs improve RMSFEs by a factor of 2, with the smallest
RMSFE=0.5% per year for the GDP deflator.


title:
Mirror Prox Algorithm for Multi-Term Composite Minimization and
  Semi-Separable Problems

abstract:
  In the paper, we develop a composite version of Mirror Prox algorithm for
solving convex-concave saddle point problems and monotone variational
inequalities of special structure, allowing to cover saddle point/variational
analogies of what is usually called "composite minimization" (minimizing a sum
of an easy-to-handle nonsmooth and a general-type smooth convex functions "as
if" there were no nonsmooth component at all). We demonstrate that the
composite Mirror Prox inherits the favourable (and unimprovable already in the
large-scale bilinear saddle point case) $O(1/\epsilon)$ efficiency estimate of
its prototype. We demonstrate that the proposed approach can be naturally
applied to Lasso-type problems with several penalizing terms (e.g. acting
together $\ell_1$ and nuclear norm regularization) and to problems of the
structure considered in the alternating directions methods, implying in both
cases methods with the $O(\epsilon^{-1})$ complexity bounds.


title:
Systematic Construction of tight-binding Hamiltonians for Topological
  Insulators and Superconductors

abstract:
  A remarkable discovery in recent years is that there exist various kinds of
topological insulators and superconductors characterized by a periodic table
according to the system symmetry and dimensionality. To physically realize
these peculiar phases and study their properties, a critical step is to
construct experimentally relevant Hamiltonians which support these topological
phases. We propose a general and systematic method based on the quaternion
algebra to construct the tight binding Hamiltonians for all the
three-dimensional topological phases in the periodic table characterized by
arbitrary integer topological invariants, which include the spin-singlet and
the spin-triplet topological superconductors, the Hopf and the chiral
topological insulators as particular examples. For each class, we calculate the
corresponding topological invariants through both geometric analysis and
numerical simulation.


title: On a class of reducible trinomials

abstract:
  In this short note we give an expression for some numbers $n$ such that the
polynomial $x^{2p}-nx^p+1$ is reducible.


title: Kinematics of the ionized-to-neutral interfaces in Monoceros R2

abstract:
  Context. Monoceros R2 (Mon R2), at a distance of 830 pc, is the only
ultra-compact H ii region (UC H ii) where its associated photon-dominated
region (PDR) can be resolved with the Herschel Space Observatory. Aims. Our aim
is to investigate observationally the kinematical patterns in the interface
regions (i.e., the transition from atomic to molecular gas) associated with Mon
R2. Methods. We used the HIFI instrument onboard Herschel to observe the line
profiles of the reactive ions CH+, OH+ and H2O+ toward different positions in
Mon R2. We derive the column density of these molecules and compare them with
gas-phase chemistry models. Results. The reactive ion CH+ is detected both in
emission (at central and red-shifted velocities) and in absorption (at
blue-shifted velocities). OH+ is detected in absorption at both blue- and
red-shifted velocities, with similar column densities. H2O+ is not detected at
any of the positions, down to a rms of 40 mK toward the molecular peak. At this
position, we find that the OH+ absorption originates in a mainly atomic medium,
and therefore is associated with the most exposed layers of the PDR. These
results are consistent with the predictions from photo-chemical models. The
line profiles are consistent with the atomic gas being entrained in the ionized
gas flow along the walls of the cavity of the H ii region. Based on this
evidence, we are able to propose a new geometrical model for this region.
Conclusions. The kinematical patterns of the OH+ and CH+ absorption indicate
the existence of a layer of mainly atomic gas for which we have derived, for
the first time, some physical parameters and its dynamics.


title: Spherical collapse and the holographic dark energy model

abstract:
  In this work we investigate the spherical collapse model in flat FRW universe
containing dark energy component. We consider the Holographic Dark Energy (HDE)
model as a dynamical dark energy scenario with slowly time varying EoS
parameter $w_{\Lambda}$ in order to calculate the effect of dark energy on the
scenario of structure formation in the universe. We first calculate the
evolution of density perturbation in linear regime for both phantom and
quintessence behavior of HDE model and compare the results with standard CDM
and $\Lambda$ CDM models. Then we calculate the evolution of two parameters
characterizing the spherical collapse model i.e., linear density threshold
$\delta_c$ and virial over-density $\Delta_{vir}$ for phantom and quintessence
HDE models. It is shown that the growth factor and $\delta_c$ fall behind in
$\Lambda$CDM universe. We also show that $\Delta_{vir}$ is largest in
quintessence HDE model, intermediate in phantom HDE compare to $\Lambda$CDM
model. Hence the growth of structures start earlier in quintessence and phantom
HDE models than $\Lambda$CDM and more concentrated objects can be produced in
these models.


title: Charge exchange reaction at high energies

abstract:
  The charge exchange reaction pp $\rightarrow$ n $\Delta^{++}$ at high
energies is examined. The cross section of this reaction is estimated for RHIC
and LHC energies based on data taken at the lower energies of the Intersecting
Storage Ring (ISR) at CERN. The interest of such measurements for identifying
the associated electromagnetic bremsstrahlung radiation is discussed.


title: The largest structure of the Universe, defined by Gamma-Ray Bursts

abstract:
  Research over the past three decades has revolutionized the field of
cosmology while supporting the standard cosmological model. However, the
cosmological principle of Universal homogeneity and isotropy has always been in
question, since structures as large as the survey size have always been found
as the survey size has increased. Until now, the largest known structure in our
Universe is the Sloan Great Wall (SGW), which is more than 400 Mpc long and
located approximately one billion light-years away. Here we report the
discovery of a structure at least six times larger than the Sloan Great Wall
that is suggested by the distribution of gamma-ray bursts (GRBs). Gamma-ray
bursts are the most energetic explosions in the Universe. They are associated
with the stellar endpoints of massive stars and are found in and near distant
galaxies. Therefore, they are very good indicators of the dense part of the
Universe containing normal matter. As of July 2012, 283 GRB redshifts have been
measured. If one subdivides this GRB sample into nine radial parts and compares
the sky distributions of these subsamples (each containing 31 GRBs), one can
observe that the fourth subsample (1.6 < z < 2.1) differs significantly from
the others in that many of the GRBs are concentrated in the same angular area
of the sky. Using the two-dimensional Kolmogorov-Smirnov test, the significance
of this observation is found to be less than 0.05 per cent. Fourteen out of the
31 Gamma-Ray Bursts in this redshift band are concentrated in approximately 1/8
of the sky. The binomial probability to find such a deviation is p=0.0000055.
This huge structure lies ten times farther away than the Sloan Great Wall, at a
distance of approximately ten billion light-years. The size of the structure
defined by these GRBs is about 2000-3000 Mpc, or more than six times the size
of the largest known object (SGW) in the Universe.


title: $T^3$ deformations and $\beta$-deformed geometries

abstract:
  We discuss $\beta$-deformed geometries on two types of $T^3$'s where the
direction along the third coordinate is not orthogonal to the direction along
the second coordinate or the direction along the first coordinate. We show that
the intersection angle between the direction along the third coordinate and the
direction along the second coordinate corresponds to the parameter of the
S-duality of the $\beta$-deformation while the intersection angle between the
direction along the third coordinate and the direction along the first
coordinate generalizes the $\beta$-deformed geometry.


title:
Equidistribution of expanding curves in homogeneous spaces and
  Diophantine approximation for square matrices

abstract:
  In this article, we study an analytic curve $\varphi: I=[a,b]\rightarrow
\mathrm{M}(n\times n, \mathbb{R})$ in the space of $n$ by $n$ real matrices,
and show that if $\varphi$ satisfies certain geometric conditions, then for
almost every point on the curve, the Diophantine approximation given by
Dirichlet's Theorem is not improvable. To do this, we embed the curve into some
homogeneous space $G/\Gamma$, and prove that under the action of some expanding
diagonal flow $A= \{a(t): t \in \mathbb{R}\}$, the expanding curves tend to be
equidistributed in $G/\Gamma$, as $t \rightarrow +\infty$. This solves a
special case of a problem proposed by Nimish Shah in ~\cite{Shah_1}.


title:
Modeling of radiative and quantum electrodynamics effects in PIC
  simulations of ultra-relativistic laser-plasma interaction

abstract:
  Next generation of ultra-intense laser facilities will lead to novel physical
conditions ruled by collective and quantum electrodynamics effects, such as
synchrotron-like emission of high-energy photons and electron-positron pair
generation. In view of the future experiments performed in this regime, the
latter processes have been implemented into the particle-in-cell code CALDER.


title: An edge variant of the Erd\H{o}s-P\'osa property

abstract:
  For every $r\in \mathbb{N}$, we denote by $\theta_{r}$ the multigraph with
two vertices and $r$ parallel edges. Given a graph $G$, we say that a subgraph
$H$ of $G$ is a model of $\theta_{r}$ in $G$ if $H$ contains $\theta_{r}$ as a
contraction. We prove that the following edge variant of the Erd{\H
o}s-P{\'o}sa property holds for every $r\geq 2$: if $G$ is a graph and $k$ is a
positive integer, then either $G$ contains a packing of $k$ mutually
edge-disjoint models of $\theta_{r}$, or it contains a set $S$ of $f_r(k)$
edges such that $G\setminus S$ has no $\theta_{r}$-model, for both $f_r(k) =
O(k^2r^3 \mathrm{polylog}~kr)$ and $f_r(k) = O(k^4r^2 \mathrm{polylog}~kr).$


title:
The First Billion Years project: dark matter haloes going from
  contraction to expansion and back again

abstract:
  We study the effect of baryons on the inner dark matter profile of the first
galaxies using the First Billion Years simulation between z=16-6 before secular
evolution sets in. Using a large statistical sample from two simulations of the
same volume and cosmological initial conditions, one with and one without
baryons, we are able to directly compare haloes with their baryon-free
counterparts, allowing a detailed study of the modifications to the dark matter
density profile due to the presence of baryons during the first billion years
of galaxy formation. For each of the ~ 5000 haloes in our sample we quantify
the impact of the baryons using eta, defined as the ratio of dark matter mass
enclosed in 100 pc in the baryonic run to its counterpart without baryons.
During this epoch of rapid growth of galaxies, we find that many haloes of
these first galaxies show an enhancement of dark matter in the halo centre
compared to the baryon-free simulation, while many others show a deficit. We
find that the mean value of eta is close to unity, but there is a large
dispersion, with a standard deviation of 0.677. The enhancement is cyclical in
time and tracks the star formation cycle of the galaxy; as gas falls to the
centre and forms stars, the dark matter moves in as well. Supernova feedback
then removes the gas, and the dark matter again responds to the changing
potential. We study three physical models relating the motion of baryons to
that of the dark matter: adiabatic contraction, dynamical friction, and rapid
outflows. Abridged, see text for full abstract


title: Localization and real Jacobi forms

abstract:
  We calculate the elliptic genus of two dimensional abelian gauged linear
sigma models with (2,2) supersymmetry using supersymmetric localization. The
matter sector contains charged chiral multiplets as well as Stueckelberg fields
coupled to the vector multiplets. These models include theories that flow in
the infrared to non-linear sigma models with target spaces that are non-compact
Kahler manifolds with U(N) isometry and with an asymptotically linear dilaton
direction. The elliptic genera are the modular completions of mock Jacobi forms
that have been proposed recently using complementary arguments. We also compute
the elliptic genera of models that contain multiple Stueckelberg fields from
first principles.


title:
Interplay of exciton condensation and quantum spin Hall effect in
  InAs/GaSb bilayers

abstract:
  We study the phase diagram of the inverted InAs/GaSb bilayer quantum wells.
For small tunneling amplitude between the layers, we find that the system is
prone to formation of an s-wave exciton condensate phase, where the
spin-structure of the order parameter is uniquely determined by the small
spin-orbit coupling arising from the bulk inversion asymmetry. The phase is
topologically trivial and does not support edge transport. On the contrary, for
large tunneling amplitude, we obtain a topologically non-trivial quantum spin
Hall insulator phase with a p-wave exciton order parameter, which enhances the
hybridization gap. These topologically distinct insulators are separated by an
insulating phase with spontaneously broken time-reversal symmetry. Close to the
phase transition between the quantum spin Hall and time-reversal broken phases,
the edge transport shows quantized conductance in small samples, whereas in
long samples the mean free path associated with the backscattering at the edge
is temperature independent, in agreement with recent experiments.


title: The curious morphology and orientation of Orion proplyd HST-10

abstract:
  HST-10 is one of the largest proplyds in the Orion Nebula and is located
approximately 1' SE of the Trapezium. Unlike other proplyds in Orion, however,
the long-axis of HST-10 does not align with theta 1 C Ori, but is instead
aligned with the rotational axis of the HST-10 disk. This cannot be easily
explained using current photo-evaporation models. In this letter, we present
high spatial resolution near-infrared images of the Orion proplyd HST-10 using
Keck/NIRC2 with the Laser Guide Star Adaptive Optics system, along with
multi-epoch analysis of HH objects near HST-10 using Hubble Space Telescope
WFPC2 and ACS cameras. Our narrow-band near-IR images resolve the proplyd
ionization front (IF) and circumstellar disk down to 23 AU at the distance to
Orion in Br gamma, He I, H_2, and PAH emission. Br gamma and He I emission
primarily trace the IF (with the disk showing prominently in silhouette), while
the H_2 and PAH emission trace the surface of the disk itself. PAH emission
also traces small dust grains within the proplyd envelope which is asymmetric
and does not coincide with the IF. The curious morphology of the PAH emission
may be due to UV-heating by both theta 1C Ori and theta 2A Ori. Multi-epoch HST
images of the HST-10 field show proper motion of 3 knots associated with HH
517, clearly indicating that HST-10 has a jet. We postulate that the
orientation of HST-10 is determined by the combined ram-pressure of this jet
and the FUV-powered photo-ablation flow from the disk surface.


title: Constraints on Higgs Couplings and Physics Beyond the Standard Model

abstract:
  We summarize current constraints on the couplings of the Higgs boson in the
framework of an effective theory beyond the Standard Model.


title: A low Fermi scale from a simple gaugino-scalar mass relation

abstract:
  In supersymmetric extensions of the Standard Model, the Fermi scale of
electroweak symmetry breaking is determined by the pattern of supersymmetry
breaking. We present an example, motivated by a higher-dimensional GUT model,
where a particular mass relation between the gauginos, third-generation squarks
and Higgs fields of the MSSM leads to a Fermi scale smaller than the soft mass
scale. This is in agreement with the measured Higgs boson mass. The mu
parameter is generated independently of supersymmetry breaking, however the mu
problem becomes less acute due to the little hierarchy between the soft mass
scale and the Fermi scale as we will argue. The resulting superparticle mass
spectra depend on the localization of quark and lepton fields in higher
dimensions. In one case, the squarks of the first two generations as well as
the gauginos and higgsinos can be in the range of the LHC. Alternatively, only
the higgsinos may be accessible at colliders. The lightest superparticle is the
gravitino.


title: Coupled-channel optical model potential for rare earth nuclei

abstract:
  Inspired by the recent work by Dietrich et al., substantiating validity of
the adiabatic assumption in coupled-channel calculations, we explore the
possibility of generalizing a global spherical optical model potential (OMP) to
make it usable in coupled-channel calculations on statically deformed nuclei.
The generalization consists in adding the coupling of the ground state
rotational band, deforming the potential by introducing appropriate quadrupole
and hexadecupole deformation and correcting the OMP radius to preserve volume
integral of the spherical OMP. We choose isotopes of three rare-earth elements
(W, Ho, Gd), which are known to be nearly perfect rotors, to perform a
consistent test of our conjecture on integrated cross sections as well as on
angular distributions for elastic and inelastic neutron scattering. When doing
this we employ the well-established Koning-Delaroche global spherical potential
and experimentally determined deformations without any adjustments. We observe
a dramatically improved agreement with experimental data compared to spherical
optical model calculations. The effect of changing the OMP radius to preserve
volume integral is moderate but visibly improves agreement at lower incident
energies. We find that seven collective states need to be considered for the
coupled-channel calculations to converge. Our results for total, elastic,
inelastic, and capture cross sections, as well as elastic and inelastic angular
distributions are in remarkable agreement with experimental data. This result
confirms that the adiabatic assumption holds and can extend applicability of
the global spherical OMP to rotational nuclei in the rare-earth region,
essentially without any free parameter. Thus, quite reliable coupled-channel
calculations can be performed on such nuclei even when the experimental data,
and consequently a specific coupled-channel potential, are not available.


title: Spot activity of the RS CVn star {\sigma} Geminorum

abstract:
  We model the photometry of RS CVn star $\sigma$ Geminorum to obtain new
information on the changes of the surface starspot distribution, i.e., activity
cycles, differential rotation and active longitudes. We use the previously
published Continuous Periods Search-method (CPS) to analyse V-band differential
photometry obtained between the years 1987 and 2010 with the T3 0.4 m Automated
Telescope at the Fairborn Observatory. The CPS-method divides data into short
subsets and then models the light curves with Fourier-models of variable orders
and provides estimates of the mean magnitude, amplitude, period and light curve
minima. These light curve parameters are then analysed for signs of activity
cycles, differential rotation and active longitudes. We confirm the presence of
two previously found stable active longitudes, synchronised with the orbital
period $P_{\rm{orb}}=19.60$d and find eight events where the active longitudes
are disrupted. The epochs of the primary light curve minima rotate with a
shorter period $P_{\rm{min,1}}=19.47$d than the orbital motion. If the
variations in the photometric rotation period were to be caused by differential
rotation, this would give a differential rotation coefficient of $\alpha \ge
0.103$. The presence of two slightly different periods of active regions may
indicate a superposition of two dynamo modes, one stationary in the orbital
frame and the other one propagating in the azimuthal direction. Our estimate of
the differential rotation is much higher than previous results. However,
simulations show that this can be caused by insufficient sampling in our data.


title:
Microscopic dynamics perspective on the relationship between Poisson
  ratio and ductility of metallic glasses

abstract:
  In metallic glasses a clear correlation had been established between
plasticity or ductility with the Poisson ratio and alternatively the ratio of
the elastic bulk modulus to the shear modulus, K/G. Such a correlation between
these two macroscopic mechanical properties is intriguing and is challenging to
explain from the dynamics on a microscopic level. Such a microscopic
explanation is provided in this paper.


title: Quench Dynamics of the Anisotropic Heisenberg Model

abstract:
  We develop an analytic approach for the study of the quench dynamics of the
anisotropic Heisenberg model (XXZ model) on the infinite line. We present the
exact time-dependent wavefunctions after a quench in an integral form for any
initial state and for any anisotropy $\Delta$ by means of a generalized Yudson
contour representation. We calculate the evolution of several observables from
two particular initial states: starting with a local N\`eel state we calculate
the time evolution of the antiferromagnetic order parameter--staggered
magnetization; starting with a state with consecutive flipped spins we
calculate the propagation of magnons and bound state excitations, and the
induced spin currents. We also show how the "string" solution of Bethe Ansatz
equations emerge naturally from the contour approach. We confront our results
with experiments and numerical methods where possible.


title: One-zone SSC model for the core emission of Centaurus A revisited

abstract:
  Aims: We investigate the role of the second synchrotron self-Compton (SSC)
photon generation to the multiwavelength emission from the compact regions of
sources that are characterized as misaligned blazars. For this, we focus on the
nearest high-energy emitting radio galaxy Centaurus A and we revisit the
one-zone SSC model for its core emission. Methods: We have calculated
analytically the peak luminosities of the first and second SSC components by,
first, deriving the steady-state electron distribution in the presence of
synchrotron and SSC cooling and, then, by using appropriate expressions for the
positions of the spectral peaks. We have also tested our analytical results
against those derived from a numerical code where the full emissivities and
cross-sections were used. Results: We show that the one-zone SSC model cannot
account for the core emission of Centaurus A above a few GeV, where the peak of
the second SSC component appears. We, thus, propose an alternative explanation
for the origin of the high energy ($\gtrsim 0.4$ GeV) and TeV emission, where
these are attributed to the radiation emitted by a relativistic proton
component through photohadronic interactions with the photons produced by the
primary leptonic component. We show that the required proton luminosities are
not extremely high, e.g. $\sim 10^{43}$ erg/s, provided that the injection
spectra are modelled by a power-law with a high value of the lower energy
cutoff. Finally, we find that the contribution of the core emitting region of
Cen A to the observed neutrino and ultra-high energy cosmic-ray fluxes is
negligible.


title:
Reducing pervasive false positive identical-by-descent segments detected
  by large-scale pedigree analysis

abstract:
  Analysis of genomic segments shared identical-by-descent (IBD) between
individuals is fundamental to many genetic applications, from demographic
inference to estimating the heritability of diseases, but IBD detection
accuracy in non-simulated data is largely unknown. In principle, it can be
evaluated using known pedigrees, as IBD segments are by definition inherited
without recombination down a family tree. We extracted 25,432 genotyped
European individuals containing 2,952 father-mother-child trios from the
23andMe, Inc. dataset. We then used GERMLINE, a widely used IBD detection
method, to detect IBD segments within this cohort. Exploiting known familial
relationships, we identified a false positive rate over 67% for 2-4 centiMorgan
(cM) segments, in sharp contrast with accuracies reported in simulated data at
these sizes. Nearly all false positives arose from the allowance of haplotype
switch errors when detecting IBD, a necessity for retrieving long (> 6 cM)
segments in the presence of imperfect phasing. We introduce HaploScore, a
novel, computationally efficient metric that scores IBD segments proportional
to the number of switch errors they contain. Applying HaploScore filtering to
the IBD data at a precision of 0.8 produced a 13-fold increase in recall when
compared to length-based filtering. We replicate the false IBD findings and
demonstrate the generalizability of HaploScore to alternative data sources
using an independent cohort of 555 European individuals from the 1000 Genomes
project. HaploScore can improve the accuracy of segments reported by any IBD
detection method, provided that estimates of the genotyping error rate and
switch error rate are available.


title:
Black holes and running couplings: A comparison of two complementary
  approaches

abstract:
  Black holes appear as vacuum solutions of classical general relativity which
depend on Newton's constant and possibly the cosmological constant. At the
level of a quantum field theory, these coupling constants typically acquire a
scale-dependence. This proceedings briefly summarizes two complementary ways to
incorporate this effect: the renormalization group improvement of the classical
black hole solution based on the running couplings obtained within the
gravitational Asymptotic Safety program and the exact solution of the improved
equations of motion including an arbitrary scale dependence of the
gravitational couplings. Remarkably the picture of the "quantum" black holes
obtained from these very different improvement strategies is surprisingly
similar.


title: On time scaling of semivariance in a jump-diffusion process

abstract:
  The aim of this paper is to examine the time scaling of the semivariance when
returns are modeled by various types of jump-diffusion processes, including
stochastic volatility models with jumps in returns and in volatility. In
particular, we derive an exact formula for the semivariance when the volatility
is kept constant, explaining how it should be scaled when considering a lower
frequency. We also provide and justify the use of a generalization of the
Ball-Torous approximation of a jump-diffusion process, this new model appearing
to deliver a more accurate estimation of the downside risk. We use Markov Chain
Monte Carlo (MCMC) methods to fit our stochastic volatility model. For the
tests, we apply our methodology to a highly skewed set of returns based on the
Barclays US High Yield Index, where we compare different time scalings for the
semivariance. Our work shows that the square root of the time horizon seems to
be a poor approximation in the context of semivariance and that our methodology
based on jump-diffusion processes gives much better results.


title: Cluster glass magnetism in the phase-separated Nd2/3Ca1/3MnO3 perovskite

abstract:
  A detailed study of the low-temperature magnetic state and the relaxation in
the phase-separated colossal magnetoresistance Nd2/3Ca1/3MnO3 perovskite has
been carried out. Clear experimental evidence of the cluster-glass magnetic
behavior of this compound has been revealed. Well defined maxima in the
in-phase linear ac susceptibility $\chi ^{/}(T)$ were observed, indicative of
the magnetic glass transition at $T_{g}$ = 60 K. Strongly divergent
zero-field-cooled and field-cooled static magnetizations and frequency
dependent ac susceptibility are evident of the glassy-like magnetic state of
the compound at low temperatures. The frequency dependence of the cusp
temperature Tmax of the $\chi ^{/}(T)$ susceptibility was found to follow the
critical slowing down mechanism. The Cole-Cole analysis of the dynamic
susceptibility at low temperature has shown extremely broad distribution of
relaxation times, indicating that spins are frozen at "macroscopic" time scale.
Slow relaxation in the zero-field-cooled magnetization has been experimentally
revealed. The obtained results do not agree with a canonical spin-glass state
and indicate a cluster glass magnetic state of the compound below $T_{g}$,
associated with its antiferromagnetic-ferromagnetic nano-phase segregated
state. It was found that the relaxation mechanisms below the cluster glass
freezing temperature $T_{g}$ and above it are strongly different. Magnetic
field up to about $\mu_{0}$H = 0.4 T suppresses the glassy magnetic state of
the compound.


title:
Coulomb corrections to photon and dilepton production in high energy pA
  collisions

abstract:
  We consider particle production in high energy pA collisions. In addition to
the coherent interactions with the nuclear color field, we take into account
coherent interactions with the nuclear electromagnetic Coulomb field. Employing
the dipole model, we sum up the leading multiple color and electromagnetic
interactions and derive inclusive cross sections for photon and dilepton
production. We found that the Coulomb corrections are up to $10\%$ at
$\sqrt{s}=200$~GeV per nucleon.


title: Twisted Phonons in Bose-Einstein condensates

abstract:
  We consider elementary excitations in a Bose Einstein condensate, carrying a
finite amount of angular momentum. We show that these elementary excitations
are modified Bogoliubov oscillations, or phonons with an helical wave
structure. These twisted phonon modes can contribute to the total vorticity in
a quantum fluid, thus complementing the contribution of the traditional quantum
vortices. Linear and nonlinear versions of twisted phonon modes will be
discussed. New envelope soliton solutions are shown to exist in a condensate.


title:
Effect of magnetic field on resonant tunneling in 3D waveguides of
  variable cross-section

abstract:
  We consider an infinite three-dimensional waveguide that far from the
coordinate origin coincides with a cylinder. The waveguide has two narrows of
diameter $\varepsilon$. The narrows play the role of effective potential
barriers for the longitudinal electron motion. The part of waveguide between
the narrows becomes a "resonator"\, and there can arise conditions for electron
resonant tunneling. A magnetic field in the resonator can change the basic
characteristics of this phenomenon. In the presence of a magnetic field, the
tunneling phenomenon is feasible for producing spin-polarized electron flows
consisting of electrons with spins of the same direction.
  We assume that the whole domain occupied by a magnetic field is in the
resonator. An electron wave function satisfies the Pauli equation in the
waveguide and vanishes at its boundary. Taking $\varepsilon$ as a small
parameter, we derive asymptotics for the probability $T(E)$ of an electron with
energy $E$ to pass through the resonator, for the "resonant energy"\,$E_{res}$,
where $T(E)$ takes its maximal value, and for some other resonant tunneling
characteristics.


title: Top Charge Asymmetry -- Theory Status Fall 2013

abstract:
  I review the current status of the charge asymmetry in hadronic top-quark
pair production from a theory perspective. The standard-model predictions for
the observables at the Tevatron and LHC are being discussed, as well as
possible explanations of the Tevatron excess in terms of new physics. I give an
outlook for future investigations of the top-quark charge asymmetry, focussing
on novel observables at the LHC.


title: Generating a state $t$-design by diagonal quantum circuits

abstract:
  We investigate protocols for generating a state $t$-design by using a fixed
separable initial state and a diagonal-unitary $t$-design in the computational
basis, which is a $t$-design of an ensemble of diagonal unitary matrices with
random phases as their eigenvalues. We first show that a diagonal-unitary
$t$-design generates a $O(1/2^N)$-approximate state $t$-design, where $N$ is
the number of qubits. We then discuss a way of improving the degree of
approximation by exploiting non-diagonal gates after applying a
diagonal-unitary $t$-design. We also show that it is necessary and sufficient
to use $O(\log_2 t)$-qubit gates with random phases to generate a
diagonal-unitary $t$-design by diagonal quantum circuits, and that each
multi-qubit diagonal gate can be replaced by a sequence of multi-qubit
controlled-phase-type gates with discrete-valued random phases. Finally, we
analyze the number of gates for implementing a diagonal-unitary $t$-design by
{\it non-diagonal} two- and one-qubit gates. Our results provide a concrete
application of diagonal quantum circuits in quantum informational tasks.


title: Discussion of "Geodesic Monte Carlo on Embedded Manifolds"

abstract:
  Contributed discussion and rejoinder to "Geodesic Monte Carlo on Embedded
Manifolds" (arXiv:1301.6064)


title:
Hybrid Monte-Carlo simulation of interacting tight-binding model of
  graphene

abstract:
  In this work, results are presented of Hybrid-Monte-Carlo simulations of the
tight-binding Hamiltonian of graphene, coupled to an instantaneous long-range
two-body potential which is modeled by a Hubbard-Stratonovich auxiliary field.
We present an investigation of the spontaneous breaking of the sublattice
symmetry, which corresponds to a phase transition from a conducting to an
insulating phase and which occurs when the effective fine-structure constant
$\alpha$ of the system crosses above a certain threshold $\alpha_C$.
Qualitative comparisons to earlier works on the subject (which used larger
system sizes and higher statistics) are made and it is established that
$\alpha_C$ is of a plausible magnitude in our simulations. Also, we discuss
differences between simulations using compact and non-compact variants of the
Hubbard field and present a quantitative comparison of distinct discretization
schemes of the Euclidean time-like dimension in the Fermion operator.


title: Compatible Weighted Proper Scoring Rules

abstract:
  Many proper scoring rules such as the Brier and log scoring rules implicitly
reward a probability forecaster relative to a uniform baseline distribution.
Recent work has motivated weighted proper scoring rules, which have an
additional baseline parameter. To date two families of weighted proper scoring
rules have been introduced, the weighted power and pseudospherical scoring
families. These families are compatible with the log scoring rule: when the
baseline maximizes the log scoring rule over some set of distributions, the
baseline also maximizes the weighted power and pseudospherical scoring rules
over the same set. We characterize all weighted proper scoring families and
prove a general property: every proper scoring rule is compatible with some
weighted scoring family, and every weighted scoring family is compatible with
some proper scoring rule.


title:
Motion and audio analysis in mobile devices for remote monitoring of
  physical activities and user authentication

abstract:
  In this article we propose the use of accelerometer embedded by default in
smartphone as a cost-effective, reliable and efficient way to provide remote
physical activity monitoring for the elderly and people requiring healthcare
service. Mobile phones are regularly carried by users during their day-to-day
work routine, physical movement information can be captured by the mobile phone
accelerometer, processed and sent to a remote server for monitoring. The
acceleration pattern can deliver information related to the pattern of physical
activities the user is engaged in. We further show how this technique can be
extended to provide implicit real-time security by analysing unexpected
movements captured by the phone accelerometer, and automatically locking the
phone in such situation to prevent unauthorised access. This technique is also
shown to provide implicit continuous user authentication, by capturing regular
user movements such as walking, and requesting for re-authentication whenever
it detects a non-regular movement.


title: Amplitude Relations in Non-linear Sigma Model

abstract:
  In this paper, we investigate tree-level scattering amplitude relations in
$U(N)$ non-linear sigma model. We use Cayley parametrization. As was shown in
the recent works [23,24] both on-shell amplitudes and off-shell currents with
odd points have to vanish under Cayley parametrization. We prove the off-shell
$U(1)$ identity and fundamental BCJ relation for even-point currents. By taking
the on-shell limits of the off-shell relations, we show that the color-ordered
tree amplitudes with even points satisfy $U(1)$-decoupling identity and
fundamental BCJ relation, which have the same formations within Yang-Mills
theory. We further state that all the on-shell general KK, BCJ relations as
well as the minimal-basis expansion are also satisfied by color-ordered tree
amplitudes. As a consequence of the relations among color-ordered amplitudes,
the total $2m$-point tree amplitudes satisfy DDM form of color decomposition as
well as KLT relation.


title: Tannakian duality over Dedekind rings and applications

abstract:
  We establish a duality between flat affine group schemes and rigid tensor
categories equipped with a neutral fiber functor (called Tannakian lattice),
both defined over a Dedekind ring. We use this duality and the known Tannakian
duality due to Saavedra to study morphisms between flat affine group schemes.
Next, we apply our new duality to the category of stratified sheaves on a
smooth scheme over a Dedekind ring R to define the relative differential
fundamental group scheme of the given scheme and compare the fibers of this
group scheme with the fundamental group scheme of the fibers. When R is a
complete DVR of equal characteristic we show that this category is Tannakian in
the sense of Saavedra.


title:
On the connection problem for the p-Laplacian system for potentials with
  several global minima

abstract:
  We study the existence of solutions to systems of ordinary differential
equations that involve the p-Laplacian for potentials with several global
minima. We consider the connection problem for potentials with two minima in
arbitrary dimensions and with three or more minima on the plane.


title: The Constant Astigmatism Equation. New Exact Solution

abstract:
  In this paper we present a new solution for the Constant Astigmatism
equation. This solution is parameterized by an arbitrary function of a single
variable.


title: Behind the Horizon in AdS/CFT

abstract:
  We extend the recent proposal of Papadodimas and Raju of a CFT construction
of operators inside the black hole interior to arbitrary non-maximally mixed
states. Our construction builds on the general prescription given in earlier
work, based on ideas from quantum error correction. We indicate how the CFT
state dependence of the interior modes can be removed by introducing an
external system, such as an observer, that is entangled with the CFT.


title: Analysis of the Gibbs sampler for hierarchical inverse problems

abstract:
  Many inverse problems arising in applications come from continuum models
where the unknown parameter is a field. In practice the unknown field is
discretized resulting in a problem in $\mathbb{R}^N$, with an understanding
that refining the discretization, that is increasing $N$, will often be
desirable. In the context of Bayesian inversion this situation suggests the
importance of two issues: (i) defining hyper-parameters in such a way that they
are interpretable in the continuum limit $N \to \infty$ and so that their
values may be compared between different discretization levels; (ii)
understanding the efficiency of algorithms for probing the posterior
distribution, as a function of large $N.$ Here we address these two issues in
the context of linear inverse problems subject to additive Gaussian noise
within a hierarchical modelling framework based on a Gaussian prior for the
unknown field and an inverse-gamma prior for a hyper-parameter, namely the
amplitude of the prior variance. The structure of the model is such that the
Gibbs sampler can be easily implemented for probing the posterior distribution.
Subscribing to the dogma that one should think infinite-dimensionally before
implementing in finite dimensions, we present function space intuition and
provide rigorous theory showing that as $N$ increases, the component of the
Gibbs sampler for sampling the amplitude of the prior variance becomes
increasingly slower. We discuss a reparametrization of the prior variance that
is robust with respect to the increase in dimension; we give numerical
experiments which exhibit that our reparametrization prevents the slowing down.
Our intuition on the behaviour of the prior hyper-parameter, with and without
reparametrization, is sufficiently general to include a broad class of
nonlinear inverse problems as well as other families of hyper-priors.


title:
Hysteresis and Relaxation Effects in the Spin-Ice Compound
  Dy$_2$Ti$_2$O$_7$ studied by Heat Transport

abstract:
  The low-temperature thermal conductivity $\kappa$ of the spin-ice compound
Dy$_2$Ti$_2$O$_7$ shows pronounced hysteresis as a function of magnetic field.
Here, we investigate how these hysteresis effects depend on temperature, the
magnetic-field direction, the rate of magnetic-field change, and on the
direction of the heat current. In addition, the time-dependent relaxation of
the heat conductivity is investigated. These measurements yield information
about possible equilibrium states and reveal that in the low-field and
low-temperature region extremely slow relaxation processes occur.


title:
Interfaces endowed with non-constant surface energies revisited with the
  d'Alembert-Lagrange principle

abstract:
  The equation of motions and the conditions on surfaces and edges between
fluids and solids in presence of non-constant surface energies, as in the case
of surfactants attached to the fluid particles at the interfaces, are revisited
under the principle of virtual work. We point out that adequate behaviors of
surface concentrations may drastically modify the surface tension which
naturally appears in the Laplace and the Young-Dupr\'e equations. Thus, the
principle of virtual work points out a strong difference between the two
revisited concepts of surface energy and surface tension.

categories: cond-mat.soft math-ph math.MP physics.chem-ph


title: Noncommutative recursions and the Laurent phenomenon

abstract:
  We exhibit a family of sequences of noncommutative variables, recursively
defined using monic palindromic polynomials in $\mathbb Q[x]$, and show that
each possesses the Laurent phenomenon. This generalizes a conjecture by
Kontsevich.


title: Giant Planet Formation, Evolution, and Internal Structure

abstract:
  The large number of detected giant exoplanets offers the opportunity to
improve our understanding of the formation mechanism, evolution, and interior
structure of gas giant planets. The two main models for giant planet formation
are core accretion and disk instability. There are substantial differences
between these formation models, including formation timescale, favorable
formation location, ideal disk properties for planetary formation, early
evolution, planetary composition, etc. First, we summarize the two models
including their substantial differences, advantages, and disadvantages, and
suggest how theoretical models should be connected to available (and future)
data. We next summarize current knowledge of the internal structures of solar-
and extrasolar- giant planets. Finally, we suggest the next steps to be taken
in giant planet exploration.


title:
The form factors for B -> pi l nu semileptonic decay from 2+1 flavors of
  domain-wall fermions

abstract:
  We present a calculation of the B -> pi l nu form factors with domain-wall
light quarks and relativistic b-quarks on the lattice. We work with the 2+1
flavor domain-wall fermion and Iwasaki gauge-field ensembles generated by the
RBC and UKQCD Collaborations. The chiral-continuum extrapolation is performed
using SU(2) hard-pion chiral perturbation theory. To extrapolate the lattice
form factors to the full kinematic range, we use the model independent
z-parameterization and impose the kinematic constraint f_+(0) = f_0(0) at zero
momentum transfer.


title:
An informal introduction to perturbations of matrices determined up to
  similarity or congruence

abstract:
  The reductions of a square complex matrix A to its canonical forms under
transformations of similarity, congruence, or *congruence are unstable
operations: these canonical forms and reduction transformations depend
discontinuously on the entries of A. We survey results about their behavior
under perturbations of A and about normal forms of all matrices A+E in a
neighborhood of A with respect to similarity, congruence, or *congruence. These
normal forms are called miniversal deformations of A; they are not uniquely
determined by A+E, but they are simple and depend continuously on the entries
of E.


title:
Characterizing the purple Earth: Modelling the globally-integrated
  spectral variability of the Archean Earth

abstract:
  The ongoing searches for exoplanetary systems have revealed a wealth of
planets with diverse physical properties. Planets even smaller than the Earth
have already been detected, and the efforts of future missions are placed on
the discovery, and perhaps characterization, of small rocky exoplanets within
the habitable zone of their stars. Clearly what we know about our planet will
be our guideline for the characterization of such planets. But the Earth has
been inhabited for at least 3.8 Ga, and its appearance has changed with time.
Here, we have studied the Earth during the Archean eon, 3.0 Ga ago. At that
time one of the more widespread life forms on the planet were purple bacteria.
These bacteria are photosynthetic microorganisms and can inhabit both aquatic
and terrestrial environments. Here, we used a radiative transfer model to
simulate the visible and near-IR radiation reflected by our planet, taking into
account several scenarios regarding the possible distribution of purple
bacteria over continents and oceans. We find that purple bacteria have a
reflectance spectrum which has a strong reflectivity increase, similar to the
red edge of leafy plants, although shifted redwards. This feature produces a
detectable signal in the disk-averaged spectra of our planet, depending on
cloud amount and on purple bacteria concentration/distribution. We conclude
that by using multi-color photometric observations, it is possible to
distinguish between an Archean Earth in which purple bacteria inhabit vast
extensions of the planet, and a present-day Earth with continents covered by
deserts, vegetation or microbial mats.


title: Variedades de \'algebras topologicas

abstract:
  Topological algebras have properties that extend naturally to those of
topological groups [8, 9], but is it the case that semi-direct products exist
as in the category of groups? Firstly, we express concepts in categorical
language that capture group properties. We then observe the results about
topological groups now extended to varieties of topological algebras. We
conclude showing that for topological algebras obeying certain axioms, there
exist semi-direct products which we caracterize like in [17].


title:
Intersection between the geometry of generalized Lie algebroids and some
  aspects of interior and exterior differential systems

abstract:
  An exterior differential calculus in the general framework of generalized Lie
algebroids is presented. A theorem of Maurer-Cartan type is obtained. All
results with details proofs are presented and a new point of view over exterior
differential calculus for Lie algebroids is obtained. Using the theory of
linear connections of Ehresmann type presented in the firstt reference, the
identities of Cartan and Bianchi type are presented. Supposing that any vector
subbundle of the pull-back Lie algebroid of a generalized Lie algebroid is
interior differential system (IDS) for that generalized Lie algebroid, then the
involutivity of the IDS in a theorem of Frobenius type is characterized.
Extending the classical notion of exterior differential system (EDS) to
generalized Lie algebroids, then the involutivity of an IDS in a theorem of
Cartan type is characterized.


title:
Channeling of particles and associated anomalous transport in a 2D
  complex plasma crystal

abstract:
  Implications of recently discovered effect of channeling of upstream extra
particles for transport phenomena in a two-dimensional plasma crystal are
discussed. Upstream particles levitated above the lattice layer and tended to
move between the rows of lattice particles. An example of heat transport is
considered, where upstream particles act as moving heat sources, which may lead
to anomalous heat transport. The average channeling length observed was 15 - 20
interparticle distances. New features of the channeling process are also
reported.


title: Stochastically excited oscillations on the upper main sequence

abstract:
  Convective envelopes in stars on the main sequence are usually connected only
with stars of spectral types F5 or later. However, observations as well as
theory indicate that the convective outer layers in earlier stars, despite
being shallow, are still effective and turbulent enough to stochastically
excite oscillations. Because of the low amplitudes, exploring stochastically
excited pulsations became possible only with space missions such as Kepler and
CoRoT. Here I review the recent results and discuss among others, pulsators
such as delta Scuti, gamma Doradus, roAp, beta Cephei, Slowly Pulsating B and
Be stars, all in the context of solar-like oscillations.


title:
Analytical solutions of the Riccati equation with coefficients
  satisfying integral or differential conditions with arbitrary functions

abstract:
  Ten new exact solutions of the Riccati equation $dy/dx=a(x)+b(x)y+c(x)y^{2}$
are presented. The solutions are obtained by assuming certain relations among
the coefficients $a(x)$, $b(x)$ and $c(x)$ of the Riccati equation, in the form
of some integral or differential expressions, also involving some arbitrary
functions. By appropriately choosing the form of the coefficients of the
Riccati equation, with the help of the conditions imposed on the coefficients,
we obtain ten new integrability cases for the Riccati equation. For each case
the general solution of the Riccati equation is also presented. The possibility
of the application of the obtained mathematical results for the study of
anisotropic general relativistic stellar models is also briefly considered.


title: The Kinematic Algebras from the Scattering Equations

abstract:
  We study kinematic algebras associated to the recently proposed scattering
equations, which arise in the description of the scattering of massless
particles. In particular, we describe the role that these algebras play in the
BCJ duality between colour and kinematics in gauge theory, and its relation to
gravity. We find that the scattering equations are a consistency condition for
a self-dual-type vertex which is associated to each solution of those
equations. We also identify an extension of the anti-self-dual vertex, such
that the two vertices are not conjugate in general. Both vertices correspond to
the structure constants of Lie algebras. We give a prescription for the use of
the generators of these Lie algebras in trivalent graphs that leads to a
natural set of BCJ numerators. In particular, we write BCJ numerators for each
contribution to the amplitude associated to a solution of the scattering
equations. This leads to a decomposition of the determinant of a certain
kinematic matrix, which appears naturally in the amplitudes, in terms of
trivalent graphs. We also present the kinematic analogues of colour traces,
according to these algebras, and the associated decomposition of that
determinant.


title: Repeatable measurements and the collapse postulate

abstract:
  J. v. Neumann justified the collapse postulate by the empirical fact of the
repeatability of a measurement at a single quantum system. However, in his
quantum mechanical treatment of the measurement process repeatability emerges
without collapse. The entangled state of the measurement device and the
measured system after their interaction ensures it already. Furthermore, this
state gives the same predictions for the measured system alone as the
description demanded by the collapse postulate.


title: Conductivity of Dirac fermions with phonon induced topological crossover

abstract:
  We study the Hall conductivity in single layer gapped Dirac fermion materials
including coupling to a phonon field, which not only modifies the
quasi-particle dynamics through the usual self-energy term but also
renormalizes directly the gap. Consequently the Berry curvature is modified. As
the temperature is increased the sign of the renormalized gap can change and
the material can cross over from a band insulator to a topological insulator at
higher temperature (T). The effective Chern numbers defined for valley and spin
Hall conductivity show a rich phase diagram with increasing temperature. While
the spin and valley DC Hall conductivity is no longer quantized at elevated
temperature a change in sign with increasing T is a clear indication of a
topological crossover. The chirality of the circularly polarized light which is
dominantly absorbed by a particular valley can change with temperature as a
result of a topological crossover.


title: Modeling of Volatility with Non-linear Time Series Model

abstract:
  In this paper, non-linear time series models are used to describe volatility
in financial time series data. To describe volatility, two of the non-linear
time series are combined into form TAR (Threshold Auto-Regressive Model) with
AARCH (Asymmetric Auto-Regressive Conditional Heteroskedasticity) error term
and its parameter estimation is studied.


title:
Electronic properties of Mn decorated silicene on hexagonal boron
  nitride

abstract:
  We study silicene on hexagonal boron nitride, using first principles
calculations. Since hexagonal boron nitride is semiconducting, the interaction
with silicene is weaker than for metallic substrates. It therefore is possible
to open a 50 meV band gap in the silicene. We further address the effect of Mn
decoration by determining the onsite Hubbard interaction parameter, which turns
out to differ significantly for decoration at the top and hollow sites. The
induced magnetism in the system is analyzed in detail.


title:
Toward particle-level filtering of individual collision events at the
  Large Hadron Collider and beyond

abstract:
  Low-energy strong interactions are a major source of background at hadron
colliders, and methods of subtracting the associated energy flow are well
established in the field. Traditional approaches treat the contamination as
diffuse, and estimate background energy levels either by averaging over large
data sets or by restricting to given kinematic regions inside individual
collision events. On the other hand, more recent techniques take into account
the discrete nature of background, most notably by exploiting the presence of
substructure inside hard jets, i.e. inside collections of particles originating
from scattered hard quarks and gluons. However, none of the existing methods
subtract background at the level of individual particles inside events. We
illustrate the use of an algorithm that can enable particle-by-particle
background discrimination at the Large Hadron Collider, and we envisage this as
the basis for a novel event filtering procedure upstream of the official jet
reconstruction pipelines. Our hope is that this new technique will improve
physics analysis when used in combination with state-of-the-art algorithms in
high-luminosity hadron collider environments.


title: Extremal functions with vanishing condition

abstract:
  We determine the optimal majorant $M^+$ and minorant $M^-$ of exponential
type for the truncation of $x\mapsto (x^2+a^2)^{-1}$ with respect to general de
Branges measures. We prove that \[ \int_\mathbb{R} (M^+ - M^-) |E(x)|^{-2}dx =
\frac{1}{a^2 K(0,0)} \] where $K$ is the reproducing kernel for
$\mathcal{H}(E)$. As an application we determine the optimal majorant and
minorant for the Heaviside function that vanish at a fixed point $\alpha = ia$
on the imaginary axis. We show that the difference of majorant and minorant has
integral value $(\pi a - \tanh(\pi a))^{-1} \pi a$.