title: The INTEGRAL/IBIS AGN catalogue: an update

abstract:
  In the most recent IBIS survey based on observations performed during the
first 1000 orbits of INTEGRAL, are listed 363 high energy emitters firmly
associated with AGN, 107 of which are reported here for the first time. We have
used X-ray data to image the IBIS 90% error circle of all the AGN in the sample
of 107, in order to obtain the correct X-ray counterparts, locate them with
arcsec accuracy and therefore pinpoint the correct optical counterparts. This
procedure has led to the optical and spectral characterization of the entire
sample. This new set consists of 34 broad line or type 1 AGN, 47 narrow line or
type 2 AGN, 18 Blazars and 8 sources of unknown class. These 8 sources have
been associated with AGN from their positional coincidence with
2MASX/Radio/X-ray sources. Seven high energy emitters have been included since
they are considered to be good AGN candidates. Spectral analysis has been
already performed on 55 objects and the results from the most recent and/or
best statistical measurements have been collected. For the remaining 52
sources, we report the spectral analysis for the first time in this work. We
have been able to obtain the full X-ray coverage of the sample making use of
data from Swift/XRT, XMM-Newton and NuSTAR. In addition to the spectral
characterization of the entire sample, this analysis has enabled us to identify
peculiar sources and by comparing different datasets, highlight flux
variability in the 2-10 keV and 20-40 keV bands.


title:
Fast adaptive estimation of log-additive exponential models in
  Kullback-Leibler divergence

abstract:
  We study the problem of nonparametric estimation of density functions with a
product form on the domain $\triangle=\{( x_1, \ldots, x_d)\in \mathbb{R}^d,
0\leq x_1\leq \dots \leq x_d \leq 1\}$. Such densities appear in the random
truncation model as the joint density function of observations. They are also
obtained as maximum entropy distributions of order statistics with given
marginals. We propose an estimation method based on the approximation of the
logarithm of the density by a carefully chosen family of basis functions. We
show that the method achieves a fast convergence rate in probability with
respect to the Kullback-Leibler divergence for densities whose logarithm
belongs to a Sobolev function class with known regularity. In the case when the
regularity is unknown, we propose an estimation procedure using convex
aggregation of the log-densities to obtain adaptability. The performance of
this method is illustrated in a simulation study.


title: Contributions of plasma physics to chaos and nonlinear dynamics

abstract:
  This topical review focusses on the contributions of plasma physics to chaos
and nonlinear dynamics bringing new methods which are or can be used in other
scientific domains. It starts with the development of the theory of Hamiltonian
chaos, and then deals with order or quasi order, for instance adiabatic and
soliton theories. It ends with a shorter account of dissipative and high
dimensional Hamiltonian dynamics, and of quantum chaos. Most of these
contributions are a spin-off of the research on thermonuclear fusion by
magnetic confinement, which started in the fifties. Their presentation is both
exhaustive and compact. [15 April 2016]


title: The Whitehead group of (almost) extra-special p-groups with p odd

abstract:
  Let p be an odd prime number. We describe the Whitehead group of all
extra-special and almost extra-special p-groups. For this we compute, for any
finite p-group P , the subgroup Cl\_1 (ZP) of SK\_1 (ZP), in terms of a genetic
basis of P. We also introduce a deflation map Cl\_1 (ZP) $\rightarrow$ Cl\_1
(Z(P/N)) , for a normal subgroup N of P , and show that it is always
surjective. Along the way, we give a new proof of the result describing the
structure of SK\_1 (ZP), when P is an elementary abelian p-group.


title: Inverse Magnetic Catalysis in Bottom-Up Holographic QCD

abstract:
  We explore the effect of magnetic field on chiral condensation in QCD via a
simple bottom up holographic model which inputs QCD dynamics through the
running of the anomalous dimension of the quark bilinear. Bottom up holography
is a form of effective field theory and we use it to explore the dependence on
the coefficients of the two lowest order terms linking the magnetic field and
the quark condensate. In the massless theory, we identify a region of parameter
space where magnetic catalysis occurs at zero temperature but inverse magnetic
catalysis at temperatures of order the thermal phase transition. The model
shows similar non-monotonic behaviour in the condensate with B at intermediate
T as the lattice data. This behaviour is due to the separation of the meson
melting and chiral transitions in the holographic framework. The introduction
of quark mass raises the scale of B where inverse catalysis takes over from
catalysis until the inverse catalysis lies outside the regime of validity of
the effective description leaving just catalysis.


title: Some estimators of the PDF and CDF of the Lindley Distribution

abstract:
  This article addresses the different methods of estimation of the probability
density function (PDF) and the cumulative distribution function (CDF) for the
Lindley distribution. Following estimation methods are considered: uniformly
minimum variance unbiased estimator (UMVUE), maximum likelihood estimator
(MLE), percentile estimator (PCE), least square estimator (LSE), weighted least
square estimator (WLSE), Cram\'{e}r-von-Mises estimator (CVME),
Anderson-Darling estimator (ADE). Monte Carlo simulations are performed to
compare the performances of the proposed methods of estimation.


title:
R-matrix realization of two-parameter quantum affine algebra
  $U_{r,s}(\widehat{gl}_n)$

abstract:
  We introduce the two-parameter quantum affine algebra
$U_{r,s}(\widehat{gl}_n)$ via the RTT realization. The Drinfeld realization is
given and the type A quantum affine algebra is proved to be a special
subalgebra of our extended algebra.


title:
Inference on covariance operators via concentration inequalities:
  k-sample tests, classification, and clustering via Rademacher complexities

abstract:
  We propose a novel approach to the analysis of covariance operators making
use of concentration inequalities. First, non-asymptotic confidence sets are
constructed for such operators. Then, subsequent applications including a k
sample test for equality of covariance, a functional data classifier, and an
expectation-maximization style clustering algorithm are derived and tested on
both simulated and phoneme data.


title:
Arbitrary quantum state engineering in three-state systems via
  Counterdiabatic driving

abstract:
  A scheme for arbitrary quantum state engineering (QSE) in three-state systems
is proposed. Firstly, starting from a set of complete orthogonal time-dependent
basis with undetermined coefficients, a time-dependent Hamiltonian is derived
via Counterdiabatic driving for the purpose of guiding the system to attain an
arbitrary target state at a predefined time. Then, on request of the assumed
target states, two single-mode driving protocols and a multi-mode driving
protocol are proposed as examples to discuss the validity of the QSE scheme.
The result of comparison between single-mode driving and multi-mode driving
shows that multi-mode driving seems to have a wider rang of application
prospect because it can drive the system to an arbitrary target state from an
arbitrary initial state also at a predefined time even without the use of
microwave fields for the transition between the two ground states. Moreover,
for the purpose of discussion in the scheme's feasibility in practice, a
polynomial ansatz as the simplest exampleis used to fix the pulses. The result
shows that the pulses designed to implement the protocols are not hard to be
realized in practice. At the end, QSE in higher-dimensional systems is also
discussed in brief as a generalization example of the scheme.


title: Criticality and Surface Tension in Rotating Horizon Thermodynamics

abstract:
  We study a modified horizon thermodynamics and the associated criticality for
rotating black hole spacetimes. Namely, we show that under a virtual
displacement of the black hole horizon accompanied by an independent variation
of the rotation parameter, the radial Einstein equation takes a form of a
"cohomogeneity two" horizon first law, $dE=TdS+\Omega dJ-\sigma dA$, where $E$
and $J$ are the horizon energy (an analogue of the Misner-Sharp mass) and the
horizon angular momentum, $\Omega$ is the horizon angular velocity, $A$ is the
horizon area, and $\sigma$ is the surface tension induced by the matter fields.
For fixed angular momentum, the above equation simplifies and the more familiar
(cohomogeneity one) horizon first law $dE=TdS-PdV$ is obtained, where $P$ is
the pressure of matter fields and $V$ is the horizon volume. A universal
equation of state is obtained in each case and the corresponding critical
behavior is studied.


title: Generalized Galilean Algebras and Newtonian Gravity

abstract:
  The non-relativistic versions of the generalized Poincar\'{e} algebras and
generalized $AdS$-Lorentz algebras are obtained. This non-relativistic algebras
are called, generalized Galilean algebras type I and type II and denoted by
$\mathcal{G}\mathfrak{B}_{n}$ and $\mathcal{G}\mathfrak{L}_{_{n}}$
respectively. Using a generalized In\"{o}n\"{u}--Wigner contraction procedure
we find that the generalized Galilean algebras type I can be obtained from the
generalized Galilean algebras type II. The $S$-expansion procedure allows us to
find the $\mathcal{G}\mathfrak{B}_{_{5}}$ algebra from the Newton--Hooke
algebra with central extension. The procedure developed in Ref. \cite{newton}
allow us to show that the non-relativistic limit of the five dimensional
Einstein--Chern--Simons gravity is given by a modified version of the Poisson
equation. The modification could be compatible with the effects of Dark Matter,
which leads us to think that Dark Matter can be interpreted as a
non-relativistic limit of Dark Energy.


title:
Generation of Electrojets in Weakly Ionized Plasmas through a
  Collisional Dynamo

abstract:
  Intense electric currents called electrojets occur in weakly ionized
magnetized plasmas. An example occurs in the Earth's ionosphere near the
magnetic equator where neutral winds drive the plasma across the geomagnetic
field. Similar processes take place in the Solar chromosphere and MHD
generators. This letter argues that not all convective neutral flows generate
electrojets and it introduces the corresponding universal criterion for
electrojet formation, $\nabla\times
(\vec{U}\times\vec{B})\neq\partial\vec{B}/\partial t$, where $\vec{U}$ is the
neutral flow velocity, $\vec{B}$ is the magnetic field, and $t$ is time. This
criterion does not depend on the conductivity tensor, $\hat{\sigma}$. For many
systems, the displacement current, $\partial\vec{B}/\partial t$, is negligible,
making the criterion even simpler. This theory also shows that the
neutral-dynamo driver that generates electrojets plays the same role as the DC
electric current plays for the generation of the magnetic field in the
Biot-Savart law.


title:
Compact spacelike surfaces in four-dimensional Lorentz-Minkowski
  spacetime with a non-degenerate lightlike normal direction

abstract:
  A spacelike surface in four-dimensional Lorentz-Minkowski spacetime through
the lightcone has a meaningful lightlike normal vector field $\eta$. Several
sufficient assumptions on such a surface with non-degenerate $\eta$-second
fundamental form are established to prove that it must be a totally umbilical
round sphere. With this aim, a new formula which relates the Gauss curvatures
of the induced metric and of the $\eta$-second fundamental form is developed.
Then, totally umbilical round spheres are characterized as the only compact
spacelike surfaces through the lightcone such that its $\eta$-second
fundamental form is non-degenerate and has constant Gauss curvature two.
Another characterizations of totally umbilical round spheres in terms of the
Gauss-Kronecker curvature of $\eta$ and the area of the $\eta$-second
fundamental form are also given.


title: Lectures on perverse sheaves on instanton moduli spaces

abstract:
  I will explain my joint paper `Instantons moduli spaces and W-algebras' with
A.Braverman, M.Finkelberg, arXiv:1406.2381. I will concentrate on the geometric
part, that is a study of perverse sheaves on instanton moduli spaces. I place a
particular emphasize on the hyperbolic restriction functor and stable envelop,
which are our key tools, and appear also in other situations in geometric
representation theory.
  These are lecture notes for a course in 2015 PCMI.

categories: math.RT hep-th math-ph math.AG math.DG math.MP


title:
Newly synthesized Zr2(Al0.58Bi0.42)C, Zr2(Al0.2Sn0.8)C, and
  Zr2(Al0.3Sb0.7)C MAX phases: A first-principles study

abstract:
  The structural, elastic, and electronic properties of newly synthesized
Zr2(Al0.58Bi0.42)C, Zr2(Al0.2Sn0.8)C, and Zr2(Al0.3Sb0.7)C MAX nanolaminates
have been studied using first-principles density functional theory (DFT)
calculations for the first time. Theoretical Vickers hardness has also been
estimated for these compounds. All the calculated results are compared with
experimental data and also with that of recently discovered Zr2AlC phase, where
available. Zr2(Al0.58Bi0.42)C and Zr2(Al0.2Sn0.8)C are the two first Bi and Sn
containing MAX compounds. The calculated structural parameters are found to be
in good agreement with the experimental data. The single crystal elastic
constants Cij and other polycrystalline elastic coefficients have been
calculated and the mechanical stabilities of these compounds have been
theoretically confirmed. The bulk modulus increases and the shear modulus
decreases due to partial Bi/Sn/Sb substitution for Al in Zr2AlC. The calculated
elastic moduli show that these Bi/Sn/Sb containing MAX phases are more
anisotropic than Zr2AlC, and have a tendency towards ductility. The Vickers
hardness decreases in the Bi/Sn/Sb containing compounds. Further, the
electronic band structures and electronic density of states (EDOS) are
calculated and the effects of different elemental substitution on these
properties are investigated. The electronic band structures show metallic
characteristics with contribution predominantly coming from the Zr 4d orbitals.
Partial presence of Bi/Sn/Sb atoms increases the EDOS at the Fermi level to
some extent. Possible implications of the theoretical results for these
recently discovered MAX nanolaminates have been discussed in detail in this
paper.


title:
TI-POOLING: transformation-invariant pooling for feature learning in
  Convolutional Neural Networks

abstract:
  In this paper we present a deep neural network topology that incorporates a
simple to implement transformation invariant pooling operator (TI-POOLING).
This operator is able to efficiently handle prior knowledge on nuisance
variations in the data, such as rotation or scale changes. Most current methods
usually make use of dataset augmentation to address this issue, but this
requires larger number of model parameters and more training data, and results
in significantly increased training time and larger chance of under- or
overfitting. The main reason for these drawbacks is that the learned model
needs to capture adequate features for all the possible transformations of the
input. On the other hand, we formulate features in convolutional neural
networks to be transformation-invariant. We achieve that using parallel siamese
architectures for the considered transformation set and applying the TI-POOLING
operator on their outputs before the fully-connected layers. We show that this
topology internally finds the most optimal "canonical" instance of the input
image for training and therefore limits the redundancy in learned features.
This more efficient use of training data results in better performance on
popular benchmark datasets with smaller number of parameters when comparing to
standard convolutional neural networks with dataset augmentation and to other
baselines.


title: Quantum Holonomy Theory and Hilbert Space Representations

abstract:
  We present a new formulation of quantum holonomy theory, which is a candidate
for a non-perturbative and background independent theory of quantum gravity
coupled to matter and gauge degrees of freedom. The new formulation is based on
a Hilbert space representation of the QHD(M) algebra, which is generated by
holonomy-diffeomorphisms on a 3-dimensional manifold and by canonical
translation operators on the underlying configuration space over which the
holonomy-diffeomorphisms form a non-commutative C*-algebra. A proof that the
state that generates the representation exist is left for later publications.


title: Comparison between TeV and non-TeV BL Lac Objects

abstract:
  BL Lacertae objects (BL Lacs) is the dominant population of TeV emitting
blazars. In this work, we investigate whether there is any special
observational properties for TeV sources. To do so, we will compare the
observational properties of TeV detected BL Lacs (TeV BLs) and non-TeV detected
BL Lac objects (non-TeV BLs). From the 3rd $Fermi$/LAT catalog (3FGL), we can
get 662 BL Lacs, out of which, 47 are TeV BLs and 615 are non-TeV BLs. Their
multi-wavelength flux densities ($F_{\rm R}$, $F_{\rm O}$, $F_{\rm X}$,
$F_{\gamma}$), photon spectral indexes ($\alpha_{\rm X}^{\rm ph}$,
$\alpha_{\gamma}^{\rm ph}$), and effective spectral indexes ($\alpha_{\rm RO}$
and $\alpha_{\rm OX}$) are compiled from the available literatures. Then the
luminosities ($\log\,{\nu}L_{\rm R}$, $\log\,{\nu}L_{\rm O}$,
$\log\,{\nu}L_{\rm X}$, $\log\,{\nu}L_{\gamma}$) are calculated. From
comparisons, we found that TeV BLs are different from low-synchrotron-peaked
BLs (LSP) and intermediate-synchrotron-peaked BLs (ISP), but TeV BLs show
similar properties as high-synchrotron-peaked BLs (HSP). Therefore, we
concentrated on comparison between TeV HSP BLs and non-TeV HSP BLs. Analysis
results suggest that TeV HSP BLs and non-TeV HSP BLs show some differences in
their $\alpha_{\rm RO}$ and $\alpha_{\gamma}^{\rm ph}$, while their other
properties are quite similar.


title:
Mass-deformed ABJ and ABJM theory, Meixner-Pollaczek polynomials, and
  $su(1,1)$ oscillators

abstract:
  We give explicit analytical expressions for the partition function of
$U(N)_{k}\times U(N+M)_{-k}$ ABJ theory at weak coupling ($k\rightarrow \infty
)$ for finite and arbitrary values of $N$ and $M$ (including the ABJM case and
its mass-deformed generalization). We obtain the expressions by identifying the
one-matrix model formulation with a Meixner-Pollaczek ensemble and using the
corresponding orthogonal polynomials, which are also eigenfunctions of a
$su(1,1)$ quantum oscillator. Wilson loops in mass-deformed ABJM are also
studied in the same limit and interpreted in terms of $su(1,1)$ coherent
states.


title: Effects of Oxygen Contamination on Monolayer GeSe: A computational study

abstract:
  Natural oxidation is a common degradation mechanism of both mechanical and
electronic properties for most of the new two-dimensional materials. From
another perspective, controlled oxidation is an option to tune material
properties, expanding possibilities for real-world applications. Understanding
the electronic structure modifications induced by oxidation is highly desirable
for new materials like monolayer GeSe, which is a new candidate for
near-infrared photodetectors. By means of first-principles calculations, we
study the influence of oxygen defects on the structure and electronic
properties of the single layer GeSe. Our calculations show that the oxidation
is an exothermic process, and it is nucleated in the germanium sites. The
oxidation can cause severe local deformations on the monolayer GeSe structure
and introduces a deep state in the bandgap or a shallow state near the
conduction band edge. Furthermore, the oxidation increases the bandgap by up to
23 %, and may induce direct to indirect bandgap transitions. These results
suggest that the natural or intentionally induced monolayer GeSe oxidation can
be a source of new optoelectronic properties, adding another important building
block to the two-dimensional layered materials.


title: Optimal constants for a mixed Littlewood type inequality

abstract:
  For $p\in\lbrack2,\infty]$ a mixed Littlewood-type inequality asserts that
there is a constant $C_{(m),p}\geq1$ such that \[ \left(
\sum_{i_{1}=1}^{\infty}\left( \sum_{i_{2},...,i_{m}=1}^{\infty
}|T(e_{i_{1}},...,e_{i_{m}})|^{2}\right) ^{\frac{1}{2}\frac{p}{p-1}}\right)
^{\frac{p-1}{p}}\leq C_{(m),p}\Vert T\Vert \] for all continuous real-valued
$m$-linear forms on $\ell_{p}\times c_{0} \times\dots\times c_{0}$ (when
$p=\infty$, $\ell_{p}$ is replaced by $c_{0})$. We prove that for $p>2.18006$
the optimal constants $C_{(m),p}$ are $\left(
2^{\frac{1}{2}-\frac{1}{p}}\right) ^{m-1}.$ When $p=\infty,$ we recover the
best constants of the mixed $\left( \ell_{1},\ell_{2}\right) $-Littlewood
inequality.


title:
Room temperature magnetism on the zigzag edges of phosphorene
  nanoribbons

abstract:
  Searching for room temperature ferromagnetic semiconductors has evolved into
a broad field of material science and spintronics for decades, nevertheless,
these novel states remain rare. Phosphorene, a monolayer black phosphorus with
a puckered honeycomb lattice structure possessing a finite band gap and high
carrier mobility, has been synthesized recently. Here we show, by means of two
different large scale quantum Monte-Carlo methods, that relatively weak
interactions can lead to remarkable edge magnetism in the phosphorene
nanoribbons. The ground state constrained path quantum Monte-Carlo simulations
reveal strong ferromagnetic correlations along the zigzag edges, and the finite
temperature determinant quantum Monte-Carlo calculations show a high Curie
temperature up to room temperature.


title:
Anisotropic superconductivity in La(O,F)BiSeS crystals revealed by
  field-angle dependent Andreev reflection spectroscopy

abstract:
  From field-angle dependent Andreev reflection spectroscopy on single crystals
of La(O,F)BiSeS, which belongs to the recently discovered BiCh 2 (Ch = S, Se)
based layered superconductors, we found that the superconductivity in
La(O,F)BiSeS is highly anisotropic. We measured a superconducting energy gap of
0.61 meV for current injected along c-axis at 1.5 K. Detailed temperature and
magnetic field dependent studies of the gap also reveal the presence of
unconventional pairing in La(O,F)BiSeS. We show that the observed anisotropic
superconducting properties can be attributed to the anisotropy in the
superconducting order parameter with a complex symmetry in superconducting
La(O,F)BiSeS.


title:
Charge ordering in Ni$^{1+}$/Ni$^{2+}$ nickelates: La$_4$Ni$_3$O$_8$ and
  La$_3$Ni$_2$O$_6$

abstract:
  Ab initio calculations have been performed to unravel the origin of the
recently found superlattice peaks in the trilayer nickelate La$_4$Ni$_3$O$_8$.
These peaks arise from static charge ordering of Ni$^{2+}$/ Ni$^{1+}$ stripes
oriented at 45$^{\circ}$ to the Ni-O bonds. An insulating state originates from
a combination of structural distortions and magnetic order, with the gap being
formed solely within the d$_{x^2-y^2}$ manifold of states. When doped,
electrons or holes would go into these states, in a similar fashion to what
occurs in the cuprates. Analogous calculations suggest that checkerboard charge
order should occur in the bilayer nickelate La$_3$Ni$_2$O$_6$. These results
reveal a close connection between La$_4$Ni$_3$O$_8$ and La$_3$Ni$_2$O$_6$ with
La$_{2-x}$Sr$_x$NiO$_4$ for x=1/3 and x=1/2, respectively.


title:
A new probe of magnetic fields in the pre-reionization epoch: II.
  Detectability

abstract:
  In the first paper of this series, we proposed a novel method to probe
large-scale intergalactic magnetic fields during the cosmic Dark Ages, using
21-cm tomography. This method relies on the effect of spin alignment of
hydrogen atoms in a cosmological setting, and on the effect of magnetic
precession of the atoms on the statistics of the 21-cm brightness-temperature
fluctuations. In this paper, we forecast the sensitivity of future tomographic
surveys to detecting magnetic fields using this method. For this purpose, we
develop a minimum-variance estimator formalism to capture the characteristic
anisotropy signal using the two-point statistics of the brightness-temperature
fluctuations. We find that, depending on the reionization history, and subject
to the control of systematics from foreground subtraction, an array of dipole
antennas in a compact-grid configuration with a collecting area slightly
exceeding one square kilometer can achieve a $1\sigma$ detection of
$\sim$$10^{-21}$ Gauss comoving (scaled to present-day value) within three
years of observation. Using this method, tomographic 21-cm surveys could thus
probe ten orders of magnitude below current CMB constraints on primordial
magnetic fields, and provide exquisite sensitivity to large-scale magnetic
fields in situ at high redshift.


title: The near-Earth asteroid population from two decades of observations

abstract:
  Determining the size and orbital distribution of the population of near-Earth
asteroids (NEAs) is the focus of intense research, with the most recent models
converging to a population of approximately $1000$ NEAs larger than 1 km and up
to approximately $10^9$ NEAs with absolute magnitude $H<30$. We present an
analysis of the combined observations of nine of the leading asteroid surveys
over the past two decades, and show that for an absolute magnitude $H<17.75$,
which is often taken as proxy for an average diameter larger than 1 km, the
population of NEAs is $920\pm10$, lower than other recent estimates. The
population of small NEAs is estimated at $(4 \pm 1)\times 10^8$ for $H<30$, and
the number of decameter NEAs is lower than other recent estimates. This
population tracks accurately the orbital distribution of recently discovered
large NEAs, and produces an estimated Earth impact rate for small NEAs in good
agreement with the bolide data.


title: Commutative Stochastic Games

abstract:
  We are interested in the convergence of the value of n-stage games as n goes
to infinity and the existence of the uniform value in stochastic games with a
general set of states and finite sets of actions where the transition is
commutative. This means that playing an action profile a 1 followed by an
action profile a 2 , leads to the same distribution on states as playing first
the action profile a 2 and then a 1. For example, absorbing games can be
reformulated as commutative stochastic games. When there is only one player and
the transition function is deterministic, we show that the existence of a
uniform value in pure strategies implies the existence of 0-optimal strategies.
In the framework of two-player stochastic games, we study a class of games
where the set of states is R m and the transition is deterministic and
1-Lipschitz for the L 1-norm, and prove that these games have a uniform value.
A similar proof shows the existence of an equilibrium in the non zero-sum case.
These results remain true if one considers a general model of finite repeated
games, where the transition is commutative and the players observe the past
actions but not the state.


title:
Nano-scale ultra-dense Z-pinches formation from laser-irradiated
  nanowire arrays

abstract:
  We show that ulta-dense Z-pinches with nanoscale dimensions can be generated
by irradiating aligned nanowires with femtosecond laser pulses of relativistic
intensity. Using fully three-dimensional relativistic particle-in-cell
simulations we demonstrate that the laser pulse drives a forward electron
current in the area around the wires. This forward current induces return
current densities of $\sim$ 0.1 Giga-Amperes per $\mu$m\textsuperscript{2}
through the wires. The resulting strong, quasi-static, self-generated azimuthal
magnetic field pinches the nanowires into hot plasmas with a peak electron
density of $> 9\cdot 10^{24}$ cm\textsuperscript{-3}, exceeding 1000 times the
critical density. Arrays of these new ultra-dense nanopinches can be expected
to lead to efficient micro-fusion and other applications.


title: Holographic Schwinger effect with a rotating probe D3-brane

abstract:
  This paper presents the potential research on holographic Schwinger effect
with rotating probe D3-brane etc. We discover, for zero temperature case in the
Schwinger effect, the faster the angular velocity, the farther the distance of
the test particles pair at D3-brane, the potential barrier of total potential
energy also grows higher and wider. This paper discovers: at finite
temperature, when S5 without rotation near the horizon, there is the failure of
the Schwinger effect because the particles will remain at annihilate state,
which is an absolute vacuum state. However, the angular velocity in S5 will
avoid the existence of the absolute vacuum near the horizon. Both zero and
finite temperature states, the achieved results completely agree with the
results of the DBI action. So the theories of this paper are consistent, all
these show that these theories will play important roles in pair production
research in the future.


title:
Ferromagnetic resonance of exchange-coupled perpendicularly magnetized
  bilayers

abstract:
  Strong ferromagnetic interlayer exchange couplings $J$ in perpendicularly
magnetized systems are becoming increasingly desirable for applications. We
study whether ferromagnetic interlayer exchange couplings can be measured by a
combination of broadband ferromagnetic resonance methods and magnetometry
hysteresis loops. For this we model the switching and the eigenexcitations in
bilayer systems comprising a soft layer coupled to a thicker harder layer that
possesses higher perpendicular magnetic anisotropy. For large $J >0$ the
switching fields are essentially independent of $J$ but the frequency of the
optical eigenmode of the bilayer and the linewidth of the acoustical and
optical eigenmode are directly sensitive to the coupling. We derive a corpus of
compact analytical expressions to analyze these frequencies, their linewidth
and discuss the meaning thereof. We illustrate this corpus on a system
mimicking the fixed layers of a magnetic tunnel junction meant for spin torque
applications.


title:
Submanifolds and differential forms on Carnot manifolds, after M. Gromov
  and M. Rumin

abstract:
  The purpose of these notes is to explain parts of Gromov's survey of
Carnot-Carathedory spaces, in the light of subsequent results of M. Rumin.
Among the rich material provided by Gromov, most of which pertains to analysis
on metric spaces, we choose to concentrate on the H{\"o}lder equivalence
problem for Carnot manifolds. The notes go to some extent into the PDE
technique used by Gromov in order to construct horizontal submanifolds. Rumin's
complex is explained too. The upshot is that both methods yield more or less
the same conclusions as far as the H{\"o}lder equivalence problem is concerned.


title:
Entropy, chaos and excited-state quantum phase transitions in the Dicke
  model

abstract:
  We study non-equilibrium processes in an isolated quantum system ---the Dicke
model--- focusing on the role played by the transition from integrability to
chaos and the presence of excited-state quantum phase transitions. We show that
both diagonal and entanglement entropies are abruptly increased by the onset of
chaos. Also, this increase ends in both cases just after the system crosses the
critical energy of the excited-state quantum phase transition. The link between
entropy production, the development of chaos and the excited-state quantum
phase transition is more clear for the entanglement entropy. On the contrary,
the heat dissipated by the process is affected neither by the onset of chaos,
nor by the excited-state quantum phase transition.


title:
Markov models for ocular fixation locations in the presence and absence
  of colour

abstract:
  We propose to model the fixation locations of the human eye when observing a
still image by a Markovian point process in R 2 . Our approach is data driven
using k-means clustering of the fixation locations to identify distinct salient
regions of the image, which in turn correspond to the states of our Markov
chain. Bayes factors are computed as model selection criterion to determine the
number of clusters. Furthermore, we demonstrate that the behaviour of the human
eye differs from this model when colour information is removed from the given
image.


title:
Hitting times, functional inequalities, lyapunov conditions and uniform
  ergodicity

abstract:
  The use of Lyapunov conditions for proving functional inequalities was
initiated in [5]. It was shown in [4, 30] that there is an equivalence between
a Poincar{\'e} inequality, the existence of some Lyapunov function and the
exponential integrability of hitting times. In the present paper, we close the
scheme of the interplay between Lyapunov conditions and functional inequalities
by $\bullet$ showing that strong functional inequalities are equivalent to
Lyapunov type conditions; $\bullet$ showing that these Lyapunov conditions are
characterized by the finiteness of generalized exponential moments of hitting
times. We also give some complement concerning the link between Lyapunov
conditions and in-tegrability property of the invariant probability measure and
as such transportation inequalities , and we show that some "unbounded Lyapunov
conditions" can lead to uniform ergodicity, and coming down from infinity
property.


title: Bergman kernels on punctured Riemann surfaces

abstract:
  In this paper we consider a punctured Riemann surface endowed with a
Hermitian metric which equals the Poincar\'e metric near the punctures and a
holomorphic line bundle which polarizes the metric. We show that the Bergman
kernel can be localized around the singularities and its local model is the
Bergman kernel of the punctured unit disc endowed with the standard Poincar\'e
metric. As a consequence, we obtain an optimal uniform estimate of the supremum
norm of the Bergman kernel, involving a fractional growth order of the tensor
power.


title:
Robust Audio Event Recognition with 1-Max Pooling Convolutional Neural
  Networks

abstract:
  We present in this paper a simple, yet efficient convolutional neural network
(CNN) architecture for robust audio event recognition. Opposing to deep CNN
architectures with multiple convolutional and pooling layers topped up with
multiple fully connected layers, the proposed network consists of only three
layers: convolutional, pooling, and softmax layer. Two further features
distinguish it from the deep architectures that have been proposed for the
task: varying-size convolutional filters at the convolutional layer and 1-max
pooling scheme at the pooling layer. In intuition, the network tends to select
the most discriminative features from the whole audio signals for recognition.
Our proposed CNN not only shows state-of-the-art performance on the standard
task of robust audio event recognition but also outperforms other deep
architectures up to 4.5% in terms of recognition accuracy, which is equivalent
to 76.3% relative error reduction.


title: Discrete stress-energy tensor in the loop O(n) model

abstract:
  We study the loop $O(n)$ model on the honeycomb lattice. By means of local
non-planar deformations of the lattice, we construct a discrete stress-energy
tensor. For $n\in [-2,2]$, it gives a new observable satisfying a part of
Cauchy-Riemann equations. We conjecture that it is approximately
discrete-holomorphic and converges to the stress-energy tensor in the
continuum, which is known to be a holomorphic function with the Schwarzian
conformal covariance. In support of this conjecture, we prove it for the case
of $n=1$ which corresponds to the Ising model. Moreover, in this case, we show
that the correlations of the discrete stress-energy tensor with primary fields
converge to their continuous counterparts, which satisfy the OPEs given by the
CFT with central charge $c=1/2$.
  Proving the conjecture for other values of $n$ remains a challenge. In
particular, this would open a road to establishing the convergence of the
interface to the corresponding $\mathrm{SLE}_\kappa$ in the scaling limit.


title: Optimal control under uncertainty and Bayesian parameters adjustments

abstract:
  We propose a general framework for studying optimal impulse control problem
in the presence of uncertainty on the parameters. Given a prior on the
distribution of the unknown parameters, we explain how it should evolve
according to the classical Bayesian rule after each impulse. Taking these
progressive prior-adjustments into account, we characterize the optimal policy
through a quasi-variational parabolic equation, which can be solved
numerically. The derivation of the dynamic programming equation seems to be new
in this context. The main difficulty lies in the nature of the set of controls
which depends in a non trivial way on the initial data through the filtration
itself.


title: Bochner integrals in ordered vector spaces

abstract:
  We present a natural way to cover an Archimedean directed ordered vector
space $E$ by Banach spaces and extend the notion of Bochner integrability to
functions with values in $E$. The resulting set of integrable functions is an
Archimedean directed ordered vector space and the integral is an order
preserving map.


title: Optimal trading with online parameters revisions

abstract:
  The aim of this paper is to explain how parameters adjustments can be
integrated in the design or the control of automates of trading. Typically, we
are interested by the online estimation of the market impacts generated by
robots or single orders, and how they/the controller should react in an optimal
way to the informations generated by the observation of the realized impacts.
This can be formulated as an optimal impulse control problem with unknown
parameters, on which a prior is given. We explain how a mix of the classical
Bayesian updating rule and of optimal control techniques allows one to derive
the dynamic programming equation satisfied by the corresponding value function,
from which the optimal policy can be inferred. We provide an example of
convergent finite difference scheme and consider typical examples of
applications.


title: The one-phase problem for harmonic measure in two-sided NTA domains

abstract:
  We show that if $\Omega\subset\mathbb R^3$ is a two-sided NTA domain with
AD-regular boundary such that the logarithm of the Poisson kernel belongs to
$\textrm{VMO}(\sigma)$, where $\sigma$ is the surface measure of $\Omega$, then
the outer unit normal to $\partial\Omega$ belongs to $\textrm{VMO}(\sigma)$
too. The analogous result fails for dimensions larger than $3$. This answers a
question posed by Kenig and Toro and also by Bortz and Hofmann.


title:
ASASSN-15jd: WZ Sge-type star with intermediate superoutburst between
  single and double ones

abstract:
  We present optical photometry of a WZ Sge-type dwarf nova (DN), ASASSN-15jd.
Its light curve showed a small dip in the middle of the superoutburst in 2015
for the first time among WZ Sge-type DNe. The unusual light curve implies a
delay in the growth of the 3:1 resonance tidal instability. Also, the light
curve is similar to those of other two WZ Sge-type stars, SSS
J122221.7$-$311523 and OT J184228.1$+$483742, which are believed to be the best
candidates for a period bouncer on the basis of their small values of the mass
ratio ($q \equiv M_{2}/M_{1}$). Additionally, the small mean superhump
amplitude ($<$ 0.1 mag) and the long duration of no ordinary superhumps at the
early stage of the superoutburst are common to the best candidates for a period
bouncer. The average superhump period was $P_{\rm sh}$ = 0.0649810(78) d and no
early superhumps were detected. Although we could not estimate the mass ratio
of ASASSN-15jd with high accuracy, this object is expected to be a candidate
for a period bouncer, a binary accounting for the missing population of
post-period minimum cataclysmic variables, based on the above characteristics.


title:
Cosmological backreaction in the presence of radiation and a
  cosmological constant

abstract:
  We construct high-precision models of the Universe that contain radiation, a
cosmological constant, and periodically distributed inhomogeneous matter. The
density contrasts in these models are allowed to be highly non-linear, and the
cosmological expansion is treated as an emergent phenomenon. This is achieved
by employing a generalised version of the post-Newtonian formalism, and by
joining together inhomogeneous regions of space-time at reflection symmetric
junctions. Using these models, we find general expressions that precisely and
unambiguously quantify the effect of small-scale inhomogeneity on the
large-scale expansion of space (an effect referred to as "back-reaction", in
the literature). We then proceed to specialize our models to the case where the
matter fields are given by a regular array of point-like particles. This allows
us to derive extremely simple expressions for the emergent Friedmann-like
equations that govern the large-scale expansion of space. It is found that the
presence of radiation tends to reduce the magnitude of back-reaction effects,
while the existence of a cosmological constant has only a negligible effect.


title:
Electromagnetic probes of a pure-glue initial state in nucleus-nucleus
  collisions at energies available at the CERN Large Hadron Collider

abstract:
  Partonic matter produced in the early stage of ultrarelativistic
nucleus-nucleus collisions is assumed to be composed mainly of gluons, and
quarks and antiquarks are produced at later times. To study the implications of
such a scenario, the dynamical evolution of a chemically nonequilibrated system
is described by the ideal (2+1)-dimensional hydrodynamics with a time dependent
(anti)quark fugacity. The equation of state interpolates linearly between the
lattice data for the pure gluonic matter and the lattice data for the
chemically equilibrated quark-gluon plasma. The spectra and elliptic flows of
thermal dileptons and photons are calculated for central Pb+Pb collisions at
the CERN Large Hadron Collider energy of $\sqrt{s_{_{\rm NN}}} = 2.76$ TeV. We
test the sensitivity of the results to the choice of equilibration times,
including also the case where the complete chemical equilibrium of partons is
reached already at the initial stage. It is shown that a suppression of quarks
at early times leads to a significant reduction of the yield of the thermal
dileptons, but only to a rather modest suppression of the $p_T$-distribution of
direct photons. It is demonstrated that an enhancement of photon and dilepton
elliptic flows might serve as a promising signature of the pure-glue initial
state.


title:
On the regularity index of $s$ equimultiple fat points not on a linear
  $(r-1)$-space, $s \le r+3$

abstract:
  We prove the Trung's conjecture about Segre's upper bound for s equimultiple
fat points not on a linear (r-1)-space, s\le r+3, by algebraic method used in
[3]. This method also may used to research other cases of fat points.


title: Weak-mixing polygonal billiards

abstract:
  We consider the set of polygons all of whose sides are vertical or horizontal
with fixed combinatorics (for example all the figure "L"s). We show that there
is a dense G $\delta$ subset of such polygons such that for each polygon in
this G $\delta$ set the billiard flow is weakly-mixing in almost every
direction.


title:
An analog of Chang inversion formula for weighted Radon transforms in
  multidimensions

abstract:
  In this work we study weighted Radon transforms in multidimensions. We
introduce an analog of Chang approximate inversion formula for such transforms
and describe all weights for which this formula is exact. In addition, we
indicate possible tomographic applications of inversion methods for weighted
Radon transforms in 3D.


title:
Linear-quadratic optimal sampled-data control problems: convergence
  result and Riccati theory

abstract:
  We consider a general linear control system and a general quadratic cost,
where the state evolves continuously in time and the control is sampled, i.e.,
is piecewise constant over a subdivision of the time interval. This is the
framework of a linear-quadratic optimal sampled-data control problem. As a
first result, we prove that, as the sampling periods tend to zero, the optimal
sampled-data controls converge pointwise to the optimal permanent control.
Then, we extend the classical Riccati theory to the sampled-data control
framework, by developing two different approaches: the first one uses a
recently established version of the Pontryagin maximum principle for optimal
sampled-data control problems, and the second one uses an adequate version of
the dynamic programming principle. In turn, we obtain a closed-loop expression
for optimal sampled-data controls of linear-quadratic problems.


title: Mission to the Gravitational Focus of the Sun: A Critical Analysis

abstract:
  The gravitational field of the sun will focus light from a distant source to
a focal point at a minimal distance of 550 Astronomical Units from the sun. A
proposed mission to this gravitational focus could use the sun as a very large
lens, allowing (in principle) a large amplification of signal from the target,
and a very high magnification. This article discusses some of the difficulties
involved in using the sun as such a gravitational telescope for a candidate
mission, that of imaging the surface of a previously-detected exoplanet. These
difficulties include the pointing and focal length, and associated high
magnification; the signal to noise ratio associated with the solar corona, and
the focal blur. In addition, a method to calculate the signal gain and
magnification is derived using the first-order deflection calculation and
classical optics, showing that the gain is finite for an on-axis source of
non-zero area.

categories: astro-ph.EP astro-ph.IM gr-qc physics.optics


title: Asymptotic Analysis for Randomly Forced MHD

abstract:
  We consider the three-dimensional magnetohydrodynamics (MHD) equations in the
presence of a spatially degenerate stochastic forcing as a model for
magnetostrophic turbulence in the Earth's fluid core. We examine the
multi-parameter singular limit of vanishing Rossby number $\epsilon$ and
magnetic Reynold's number $\delta$, and establish that: (i) the limiting
stochastically driven active scalar equation (with $\epsilon =\delta=0$)
possesses a unique ergodic invariant measure, and (ii) any suitable sequence of
statistically invariant states of the full MHD system converge weakly, as
$\epsilon,\delta \rightarrow 0$, to the unique invariant measure of the limit
equation. This latter convergence result does not require any conditions on the
relative rates at which $\varepsilon, \delta$ decay.
  Our analysis of the limit equation relies on a recently developed theory of
hypo-ellipticity for infinite-dimensional stochastic dynamical systems. We
carry out a detailed study of the interactions between the nonlinear and
stochastic terms to demonstrate that a H\"{o}rmander bracket condition is
satisfied, which yields a contraction property for the limit equation in a
suitable Wasserstein metric. This contraction property reduces the convergence
of invariant states in the multi-parameter limit to the convergence of
solutions at finite times. However, in view of the phase space mismatch between
the small parameter system and the limit equation, and due to the
multi-parameter nature of the problem, further analysis is required to
establish the singular limit. In particular, we develop methods to lift the
contraction for the limit equation to the extended phase space, including the
velocity and magnetic fields. Moreover, for the convergence of solutions at
finite times we make use of a probabilistic modification of the Gr\"onwall
inequality, relying on a delicate stopping time argument.


title: Coupled Mode Theory of Optomechanical Crystals

abstract:
  Acousto-optic interaction in optomechanical crystals allows unidirectional
control of elastic waves over optical waves. However, as a result of this
nonlinear interaction, infinitely many optical modes are born. This article
presents an exact formulaion of coupled mode theory for interaction between
elastic and photonic Bloch waves moving along an optomechanical waveguide. In
general, an optical wavefront is strongly diffracted by an elastic wave in
frequency and wavevector, and thus infinite modes with different frequencies
and wavevectors appear. We discuss resonance and mode conversion conditions,
and present a rigorous method to derive coupling rates and mode profiles. We
also find a conservation law which rules over total optical power from
interacting individual modes. We present application examples to the theory to
optomechanical waveguides and cavities, as well as non-reciprocal transmission
of light and optomechanical switches.


title:
Spontaneous breaking of Lorentz symmetry in $(2+\epsilon)$-dimensional
  QED

abstract:
  The phase diagram of massless quantum electrodynamics in three space-time
dimensions as a function of fermion flavor number $N$ exhibits two well-known
phases: at large $N > N_c^{conf}$ the system is in a conformal gapless state,
while for small $N < N_c^{\chi SB}$ the fermions are expected to develop a
dynamical mass due to spontaneous chiral symmetry breaking. Using $\epsilon$
expansion near the lower critical dimension of 2, as well as the recent results
on the generalization of the $F$ theorem to continuous dimension, we show that
$N_c^{conf} > N_c^{\chi SB}$. There is therefore an intermediate range of
values of $N$ at which a third phase is stabilized. We demonstrate that this
phase is characterized by spontaneous breaking of Lorentz symmetry, in which a
composite vector boson field acquires a vacuum expectation value with the
fermions and the photon remaining massless.


title:
Accurate computations of bound state properties in three- and
  four-electron atomic systems in the basis of multi-dimensional gaussoids

abstract:
  Results of accurate computations of bound states in three- and four-electron
atomic systems are discussed. Bound state properties of the four-electron
lithium ion Li$^{-}$ in its ground $2^{2}S-$state are determined from the
results of accurate, variational computations. We also consider a closely
related problem of accurate numerical evaluation of the half-life of the
beryllium-7 isotope. This problem is of paramount importance for modern
radiochemistry.


title: Iterative Judgment Aggregation

abstract:
  Judgment aggregation problems form a class of collective decision-making
problems represented in an abstract way, subsuming some well known problems
such as voting. A collective decision can be reached in many ways, but a direct
one-step aggregation of individual decisions is arguably most studied. Another
way to reach collective decisions is by iterative consensus building --
allowing each decision-maker to change their individual decision in response to
the choices of the other agents until a consensus is reached. Iterative
consensus building has so far only been studied for voting problems. Here we
propose an iterative judgment aggregation algorithm, based on movements in an
undirected graph, and we study for which instances it terminates with a
consensus. We also compare the computational complexity of our iterative
procedure with that of related judgment aggregation operators.


title:
Momentum-space structure of surface states in a topological semimetal
  with a nexus point of Dirac lines

abstract:
  Three-dimensional topological semimetals come in different variants, either
containing Weyl points or Dirac lines. Here we describe a more complicated
momentum-space topological defect where several separate Dirac lines connect
with each other, forming a momentum-space equivalent of the real-space nexus
considered before for Helium-3. Close to the nexus the Dirac lines exhibit a
transition from type I to type II lines. We consider a general model of stacked
honeycomb lattices with the symmetry of Bernal (AB) stacked graphite and show
that the structural mirror symmetries in such systems protect the presence of
the Dirac lines, and also naturally lead to the formation of the nexus. By the
bulk-boundary correspondence of topological media, the presence of Dirac lines
lead to the formation of drumhead surface states at the side surfaces of the
system. We calculate the surface state spectrum, and especially illustrate the
effect of the nexus on these states.


title:
Perennial life-histories and demographic advantages may play
  contradictory roles in the evolution of plant mating systems

abstract:
  When predicting the fate and consequences of recurring deleterious mutations
in self-fertilising populations most models developed make the assumption that
populations have discrete non-overlapping generations. This makes them
biologically irrelevant when considering perennial species with over-lapping
generations and where mating occurs independently of the age group. Previous
models studying the effect of perennial life-histories on the genetic
properties of populations in the presence of self-fertilisation have done so
considering age-dependent selection and have found that, contrary to empirical
observations, perennial populations should exhibit lower levels of inbreeding
depression. Here we propose a simple deterministic model in continuous time
with selection at different fitness traits and feedback between population
fitness and size. We find that a perennial life-history can result in high
levels of inbreeding depression in spite of inbreeding, due to higher
frequencies of heterozygous individuals at the adult stage. We also propose
that there may be demographic advantages for self-fertilisation that are
independent of reproductive success.


title: p-quotients of the G.Higman group

abstract:
  These notes are based on the mini-course "On the Graham Higman group", given
at the Erwin Schr\"odinger Institute in Vienna, January 20, 22, 27 and 29,
2016, as a part of the Measured Group Theory program. The main purpose is to
describe p-quotients of the Higman group $H(k)$ for $p|(k-1)$. (One may check
that the condition $p|(k-1)$ is necessary for the existence of such quotients.)


title:
The effects of the stellar wind and orbital motion on the jets of
  high-mass microquasars

abstract:
  High-mass microquasar jets propagate under the effect of the wind from the
companion star, and the orbital motion of the binary system. The stellar wind
and the orbit may be dominant factors determining the jet properties beyond the
binary scales.} An analytical study is performed to characterize the effects of
the stellar wind and the orbital motion on the jet properties. Accounting for
the wind thrust transferred to the jet, we derive analytical estimates to
characterize the jet evolution under the impact of the stellar wind. We include
the Coriolis force effect, induced by orbital motion and enhanced by the wind
presence. Large-scale evolution of the jet is sketched accounting for
wind-to-jet thrust transfer, total energy conservation, and wind-jet flow
mixing. If the angle of the wind-induced jet bending is larger than its
half-opening angle, the following is expected: (i) a strong recollimation
shock; (ii) bending against orbital motion, caused by Coriolis forces and
enhanced by the wind presence; and (iii) non-ballistic helical propagation
further away. Even if disrupted, the jet can reaccelerate due to ambient
pressure gradients, but wind entrainment can weaken this acceleration. On large
scales, the opening angle of the helical structure is determined by the
wind-jet thrust relation, and the wind-loaded jet flow can be rather slow. The
impact of stellar winds on high-mass microquasar jets can yield non-ballistic
helical jet trajectories, jet partial disruption and wind mixing, shocks, and
possibly non-thermal emission. Among several observational diagnostics at
different bands, the radio morphology on milliarcsecond scales can be
particularly insightful regarding the wind-jet interaction.


title: Row-less Universal Schema

abstract:
  Universal schema jointly embeds knowledge bases and textual patterns to
reason about entities and relations for automatic knowledge base construction
and information extraction. In the past, entity pairs and relations were
represented as learned vectors with compatibility determined by a scoring
function, limiting generalization to unseen text patterns and entities.
Recently, 'column-less' versions of Universal Schema have used compositional
pattern encoders to generalize to all text patterns. In this work we take the
next step and propose a 'row-less' model of universal schema, removing explicit
entity pair representations. Instead of learning vector representations for
each entity pair in our training set, we treat an entity pair as a function of
its relation types. In experimental results on the FB15k-237 benchmark we
demonstrate that we can match the performance of a comparable model with
explicit entity pair representations using a model of attention over relation
types. We further demonstrate that the model per- forms with nearly the same
accuracy on entity pairs never seen during training.


title: Pebble Accretion and the Diversity of Planetary Systems

abstract:
  I examine the standard model of planet formation, including pebble accretion,
using numerical simulations. Planetary embryos large enough to become giant
planets do not form beyond the ice line within a typical disk lifetime unless
icy pebbles stick at higher speeds than in experiments using rocky pebbles.
Systems like the Solar System (small inner planets, giant outer planets) can
form if (i) icy pebbles are stickier than rocky pebbles, and (ii) the
planetesimal formation efficiency increases with pebble size, which prevents
the formation of massive terrestrial planets. Growth beyond the ice line is
dominated by pebble accretion. Most growth occurs early, when the surface
density of pebbles is high due to inward drift of pebbles from the outer disk.
Growth is much slower after the outer disk is depleted. The outcome is
sensitive to the disk radius and turbulence level, which control the lifetime
and maximum size of pebbles. The outcome is sensitive to the size of the
largest planetesimals since there is a threshold mass for the onset of pebble
accretion. The planetesimal formation rate is unimportant provided that some
large planetesimals form while pebbles remain abundant. Two outcomes are seen,
depending on whether pebble accretion begins while pebbles are still abundant.
Either (i) multiple gas giant planets form beyond the ice line, small planets
form close to the star, and a Kuiper-belt-like disk of bodies is scattered
outwards by the giant planets; or (ii) no giants form and bodies remain
Earth-mass or smaller.


title:
Complete algebraic classification of the hypersurfaces of the maximum
  inaccuracies of an indirectly measurable variable

abstract:
  Let an indirectly measurable variable be represented as a function of a
finite number of directly measurable variables . In our previous researches we:
1) represented the maximum inaccuracies of in first degree of approximation as
linear functions of the inaccuracies of ; 2) defined the spaces of the maximum
inaccuracies and we defined a dimensionless scale for quality (accuracy)
evaluation of an experiment in them; 3) introduced the maximum inaccuracies in
second degree of approximation.
  In the current paper we prove that the maximum inaccuracies of in second
degree of approximation are quadrics of the inaccuracies of and that these
forms describe certain types of quadric hypersurfaces of parabolic class.
Moreover: 1) we give a complete algebraic classification of these
hypersurfaces; 2) we define a dimensionless scale for quality (accuracy)
evaluation of the experiment given the maximum inaccuracies in second degree of
approximation.


title: On polynomial $n$-tuples of commuting isometries

abstract:
  We extend some of the results of Agler, Knese, and McCarthy [1] to $n$-tuples
of commuting isometries for $n>2$. Let $\mathbb{V}=(V_1,\dots,V_n)$ be an
$n$-tuple of a commuting isometries on a Hilbert space and let
Ann$(\mathbb{V})$ denote the set of all $n$-variable polynomials $p$ such that
$p(\mathbb{V})=0$. When Ann$(\mathbb{V})$ defines an affine algebraic variety
of dimension 1 and $\mathbb{V}$ is completely non-unitary, we show that
$\mathbb{V}$ decomposes as a direct sum of $n$-tuples
$\mathbb{W}=(W_1,\dots,W_n)$ with the property that, for each $i=1,\dots,n$,
$W_i$ is either a shift or a scalar multiple of the identity. If $\mathbb{V}$
is a cyclic $n$-tuple of commuting shifts, then we show that $\mathbb{V}$ is
determined by Ann$(\mathbb{V})$ up to near unitary equivalence, as defined in
[1].


title: Spherically-symmetric solutions in general relativity

abstract:
  We present a tetrad-based method for solving the Einstein field equations for
spherically-symmetric systems and compare it with the widely-used
Lema\^itre-Tolman-Bondi (LTB) model. In particular, we focus on the issues of
gauge ambiguity and the use of comoving versus 'physical' coordinate systems.
We also clarify the correspondences between the two approaches, and illustrate
their differences by applying them to the classic examples of the Schwarzschild
and Friedmann-Robertson-Walker spacetimes. We demonstrate that the tetrad-based
method does not suffer from the gauge freedoms inherent to the LTB model,
naturally accommodates non-zero pressure and has a more transparent physical
interpretation. We further apply our tetrad-based method to a generalised form
of 'Swiss cheese' model, which consists of an interior spherical region
surrounded by a spherical shell of vacuum that is embedded in an exterior
background universe. In general, we allow the fluid in the interior and
exterior regions to support pressure, and do not demand that the interior
region be compensated. We pay particular attention to the form of the solution
in the intervening vacuum region and verify the validity of Birkhoff's theorem
at both the metric and tetrad level. We then reconsider critically the original
theoretical arguments underlying the so-called $R_h = ct$ cosmological model,
which has recently received considerable attention. These considerations in
turn illustrate the interesting behaviour of a number of 'horizons' in general
cosmological models.


title:
Molecular dynamics study of accelerated ion-induced shock waves in
  biological media

abstract:
  We present a molecular dynamics study of the effects of carbon- and iron-ion
induced shock waves in DNA duplexes in liquid water. We use the CHARMM force
field implemented within the MBN Explorer simulation package to optimize and
equilibrate DNA duplexes in liquid water boxes of different sizes and shapes.
The translational and vibrational degrees of freedom of water molecules are
excited according to the energy deposited by the ions and the subsequent shock
waves in liquid water are simulated. The pressure waves generated are studied
and compared with an analytical hydrodynamics model which serves as a benchmark
for evaluating the suitability of the simulation boxes. The energy deposition
in the DNA backbone bonds is also monitored as an estimation of biological
damage, something which lies beyond the possibilities of the analytical model.


title:
Probing Non-holomorphic MSSM via precision constraints, dark matter and
  LHC data

abstract:
  In this analysis we explore the phenomenological constraints of models with
non-holomorphic soft SUSY breaking terms in a beyond the MSSM scenario having
identical particle content. The model referred as NHSSM shows various promising
features like the possibility of a strong reduction in electroweak fine-tuning
even for a scenario of a heavy higgsino type of LSP, a fact that is unavailable
in pMSSM models. The other important aspect is satisfying the muon $g-2$ data
even for a small $\tan\beta$ via a small value of coupling $A_\mu'$ associated
with the tri-linear non-holomorphic soft term. Thus, a large SUSY contribution
to muon $g-2$ is possible even for a significantly large smuon mass $m_{\tilde
{\mu_1}}$. The Higgs mass radiative corrections are contributed by both the
holomorphic and non-holomorphic trilinear soft parameters $A_t$ and $A_t'$,
thus diluting the requirement to have a larger $A_t$ to satisfy the Higgs mass
data. The model also provides with valid parameter space satisfying the
constraint of $B \rightarrow X_s +\gamma$ for large values of $\tan\beta$, a
scenario unfavourable in pMSSM.


title: Infinite rank spinor and oscillator representations

abstract:
  We develop a functorial theory of spinor and oscillator representations
parallel to the theory of Schur functors for general linear groups. This
continues our work on developing orthogonal and symplectic analogues of Schur
functors. As such, there are a few main points in common. We define a category
of representations of what might be thought of as the infinite rank pin and
metaplectic groups, and give three models of this category in terms of:
multilinear algebra, diagram categories, and twisted Lie algebras. We also
define specialization functors to the finite rank groups and calculate the
derived functors.


title: A big bounce, slow-roll inflation and dark energy from conformal gravity

abstract:
  We examine the cosmological sector of a gauge theory of gravity based on the
SO(4,2) conformal group of Minkowski space. We allow for conventional matter
coupled to the spacetime metric as well as matter coupled to the field that
gauges special conformal transformations. An effective cosmological constant is
generated dynamically via solution of the equations of motion, and this allows
us to recover the late time acceleration of the universe. Furthermore,
gravitational fields sourced by ordinary cosmological matter (i.e. dust and
radiation) are significantly weakened in the very early universe, which has the
effect of replacing the big bang with a big bounce. Finally, we find that this
bounce is followed by a period of nearly-exponential slow roll inflation that
can last long enough to explain the large scale homogeneity of the cosmic
microwave background.


title:
The ruin problem for L\'evy-driven linear stochastic equations with
  applications to actuarial models with negative risk sums

abstract:
  We study the asymptotic of the ruin probability for a process which is the
solution of linear SDE defined by a pair of independent L\'evy processes. Our
main interest is the model describing the evolution of the capital reserve of
an insurance company selling annuities and investing in a risky asset. Let
$\beta>0$ be the root of the cumulant-generating function $H$ of the increment
of the log price process $V$. We show that the ruin probability admits the
exact asymptotic $Cu^{-\beta}$ as the initial capital $u\to\infty$ assuming
only that the law of $V_T$ is non-arithmetic without any further assumptions on
the price process.


title:
Modeling the disequilibrium species for Jupiter and Saturn: Implications
  for Juno and Saturn entry probe

abstract:
  Disequilibrium species have been used previously to probe the deep water
abundances and the eddy diffusion coefficient for giant planets. In this paper,
we present a diffusion-kinetics code that predicts the abundances of
disequilibrium species in the tropospheres of Jupiter and Saturn with updated
thermodynamic and kinetic data. The dependence on the deep water abundance and
the eddy diffusion coefficient is investigated. We quantified the disagreements
in CO kinetics that comes from using different reaction networks and identified
C$_2$H$_6$ as a useful tracer for the eddy diffusion coefficient. We first
apply a H/P/O reaction network to Jupiter and Saturn's atmospheres and suggest
a new PH$_3$ destruction pathway. New chemical pathways for SiH$_4$ and GeH$_4$
destruction are also suggested, and another AsH$_3$ destruction pathway is
investigated thanks to new thermodynamic and kinetic data. These new models
should enhance the interpretation of the measurement of disequilibrium species
by JIRAM on board Juno and allow disentangling between methods for constraining
the Saturn's deep water abundance with the Saturn entry probes envisaged by
NASA or ESA.


title: Pre-big bang geometric extensions of inflationary cosmologies

abstract:
  Robertson-Walker spacetimes within a large class are geometrically extended
to larger cosmologies that include spacetime points with zero and negative
cosmological times. In the extended cosmologies, the big bang is lightlike, and
though singular, it inherits some geometric structure from the original
spacetime. Spacelike geodesics are continuous across the cosmological time zero
submanifold which is parameterized by the radius of Fermi space slices, i.e, by
the proper distances along spacelike geodesics from a comoving observer to the
big bang. The continuous extension of the metric, and the continuously
differentiable extension of the leading Fermi metric coefficient $g_{\tau\tau}$
of the observer, restrict the geometry of spacetime points with pre-big bang
cosmological time coordinates. In our extensions the big bang is two
dimensional in a certain sense, consistent with some findings in quantum
gravity.


title:
Deformation effects in the alpha accompanied cold ternary fission of
  even-even $^{244-260}$Cf isotopes

abstract:
  Within the Unified ternary fission model (UTFM), the alpha accompanied
ternary fission of even-even $^{244-260}$Cf isotopes has been studied by taking
the interacting barrier as the sum of Coulomb and proximity potential. For the
alpha accompanied ternary fission of 244^Cf isotope, the highest yield is
obtained for the fragment combination 108^Ru+4^He+132^Te, which contain near
doubly magic nuclei 132^Te (N=80, Z=52). In the case of 246^Cf and 248^Cf
isotopes, the highest yield is obtained for the fragment combinations with near
doubly magic nuclei 134^Te (N=82, Z=52) as the heavier fragment. The highest
yield obtained for 250^Cf, 252^Cf, 254^Cf, 256^Cf, 258^Cf and 260^Cf isotopes
is for the fragment combination with doubly magic nuclei 132^Sn (N=82, Z=50) as
the heavier fragment. We have included the effect of deformation and
orientation of fragments and this has revealed that in addition to closed shell
effect, ground state deformation also plays an important role in the
calculation of relative yield of favorable fragment combinations. The computed
isotopic yields for alpha accompanied ternary fission of 252^Cf isotope are
found to be in agreement with the experimental data. The emission probability
and kinetic energy of long range alpha particle is calculated for the various
isotopes of Cf and are found to be in good agreement with the experimental
data.


title:
A novel method for the injection and manipulation of magnetic charge
  states in nanostructures

abstract:
  Realising the promise of next-generation magnetic nanotechnologies is
contingent on the development of novel methods for controlling magnetic states
at the nanoscale. There is currently demand for simple and flexible techniques
to access exotic magnetisation states without convoluted fabrication and
application processes. 360 degree domain walls (metastable twists in
magnetisation separating two domains with parallel magnetisation) are one such
state, which is currently of great interest in data storage and magnonics.
Here, we demonstrate a straightforward and powerful process whereby a moving
magnetic charge, provided experimentally by a magnetic force microscope tip,
can write and manipulate magnetic charge states in ferromagnetic nanowires. The
method is applicable to a wide range of nanowire architectures with
considerable benefits over existing techniques. We confirm the method's
efficacy via the injection and spatial manipulation of 360 degree domain walls
in Py and Co nanowires. Experimental results are supported by micromagnetic
simulations of the tip-nanowire interaction.


title: Umbilical properties of spacelike co-dimension two submanifolds

abstract:
  For Riemannian submanifolds of a semi-Riemannian manifold, we introduce the
concepts of \emph{total shear tensor} and \emph{shear operators} as the
trace-free part of the corresponding second fundamental form and shape
operators. The relationship between these quantities and the umbilical
properties of the submanifold is shown. Several novel notions of umbilical
submanifolds are then considered along with the classical concepts of totally
umbilical and pseudo-umbilical submanifolds.
  Then we focus on the case of co-dimension $2$, and we present necessary and
sufficient conditions for the submanifold to be umbilical with respect to a
normal direction. Moreover, we prove that the umbilical direction, if it
exists, is unique ---unless the submanifold is totally umbilical--- and we give
a formula to compute it explicitly. When the ambient manifold is Lorentzian we
also provide a way of determining its causal character. We end the paper by
illustrating our results on the Lorentzian geometry of the Kerr black hole.


title:
Perfect-Information Stochastic Games with Generalized Mean-Payoff
  Objectives

abstract:
  Graph games provide the foundation for modeling and synthesizing reactive
processes. In the synthesis of stochastic reactive processes, the traditional
model is perfect-information stochastic games, where some transitions of the
game graph are controlled by two adversarial players, and the other transitions
are executed probabilistically. We consider such games where the objective is
the conjunction of several quantitative objectives (specified as mean-payoff
conditions), which we refer to as generalized mean-payoff objectives. The basic
decision problem asks for the existence of a finite-memory strategy for a
player that ensures the generalized mean-payoff objective be satisfied with a
desired probability against all strategies of the opponent. A special case of
the decision problem is the almost-sure problem where the desired probability
is 1. Previous results presented a semi-decision procedure for
epsilon-approximations of the almost-sure problem. In this work, we show that
both the almost-sure problem as well as the general basic decision problem are
coNP-complete, significantly improving the previous results. Moreover, we show
that in the case of 1-player stochastic games, randomized memoryless strategies
are sufficient and the problem can be solved in polynomial time. In contrast,
in two-player stochastic games, we show that even with randomized strategies
exponential memory is required in general, and present a matching exponential
upper bound. We also study the basic decision problem with infinite-memory
strategies and present computational complexity results for the problem. Our
results are relevant in the synthesis of stochastic reactive systems with
multiple quantitative requirements.


title: Learning Unknown Service Rates in Queues: A Multi-Armed Bandit Approach

abstract:
  Consider a queueing system consisting of multiple servers. Jobs arrive over
time and enter a queue for service; the goal is to minimize the size of this
queue. At each opportunity for service, at most one server can be chosen, and
at most one job can be served. Service is successful with a probability (the
service probability) that is a priori unknown for each server. An algorithm
that knows the service probabilities (the "genie") can always choose the server
of highest service probability. We study algorithms that learn the unknown
service probabilities. Our goal is to minimize queue-regret: the (expected)
difference between the queue-lengths obtained by the algorithm, and those
obtained by the "genie."
  Since queue-regret cannot be larger than classical regret, results for the
standard multi-armed bandit problem give algorithms for which queue-regret
increases no more than logarithmically in time. Our paper shows surprisingly
more complex behavior. In particular, as long as the bandit algorithm's queues
have relatively long regenerative cycles, queue-regret is similar to cumulative
regret, and scales (essentially) logarithmically. However, we show that this
"early stage" of the queueing bandit eventually gives way to a "late stage",
where the optimal queue-regret scaling is $O(1/t)$. We demonstrate an algorithm
that (order-wise) achieves this asymptotic queue-regret in the late stage. Our
results are developed in a more general model that allows for multiple job
classes as well.


title: NEWTON's trajectories versus MOND's trajectories

abstract:
  MOND dynamics consists of a modification of the acceleration with respect to
the one provided by Newtonian mechanics. In this paper we investigate whether
it can be derived from a velocity-dependent deformation of the coordinates of
the systems. The conclusion is that it cannot be derived this way because of
the intrinsic non-local character in time of the MOND procedure. This is a
feature pointed out some time ago already by Milgrom himself.


title:
Automatic Inference of Graph Transformation Rules Using the Cyclic
  Nature of Chemical Reactions

abstract:
  Graph transformation systems have the potential to be realistic models of
chemistry, provided a comprehensive collection of reaction rules can be
extracted from the body of chemical knowledge. A first key step for rule
learning is the computation of atom-atom mappings, i.e., the atom-wise
correspondence between products and educts of all published chemical reactions.
This can be phrased as a maximum common edge subgraph problem with the
constraint that transition states must have cyclic structure. We describe a
search tree method well suited for small edit distance and an integer linear
program best suited for general instances and demonstrate that it is feasible
to compute atom-atom maps at large scales using a manually curated database of
biochemical reactions as an example. In this context we address the network
completion problem.


title:
Asymptotic properties of a Nadaraya-Watson type estimator for regression
  functions of infinite order

abstract:
  We consider a class of nonparametric time series regression models in which
the regressor takes values in a sequence space. Technical challenges that
hampered theoretical advances in these models include the lack of associated
Lebesgue density and difficulties with regard to the choice of dependence
structure in the autoregressive framework. We propose an infinite-dimensional
Nadaraya-Watson type estimator, and investigate its asymptotic properties in
detail under both static regressive and autoregressive contexts, aiming to
answer the open questions left by Linton and Sancetta (2009). First we show
pointwise consistency of the estimator under a set of mild regularity
conditions. Furthermore, the asymptotic normality of the estimator is
established, and then its uniform strong consistency is shown over a compact
set of logarithmically increasing dimension with respect to $\alpha$-mixing and
near epoch dependent (NED) samples. We specify the explicit rates of
convergence in terms of the Lambert W function, and show that the optimal rate
is of logarithmic order, confirming the existence of the curse of infinite
dimensionality.


title:
Two faces of Douglas-Kazakov transition: from Yang-Mills theory to
  random walks and beyond

abstract:
  Being inspired by the connection between 2D Yang-Mills (YM) theory and (1+1)D
"vicious walks" (VW), we consider different incarnations of large-$N$
Douglas-Kazakov (DK) phase transition in gauge field theories and stochastic
processes focusing at possible physical interpretations. We generalize the
connection between YM and VW, study the influence of initial and final
distributions of walkers on the DK phase transition, and describe the effect of
the $\theta$-term in corresponding stochastic processes. We consider the Jack
stochastic process involving Calogero-type interaction between walkers and
investigate the dependence of DK transition point on a coupling constant.
Relying on the relation between large-$N$ 2D $q$-YM and extremal black hole
(BH) with large-$N$ magnetic charge, we speculate about a physical
interpretation of a DK phase transitions in a 4D extremal charged BH.

categories: hep-th cond-mat.stat-mech math-ph math.MP


title:
A characterization of trees with equal 2-domination and 2-independence
  numbers

abstract:
  A set $S$ of vertices in a graph $G$ is a $2$-dominating set if every vertex
of $G$ not in $S$ is adjacent to at least two vertices in $S$, and $S$ is a
$2$-independent set if every vertex in $S$ is adjacent to at most one vertex of
$S$. The $2$-domination number $\gamma_2(G)$ is the minimum cardinality of a
$2$-dominating set in $G$, and the $2$-independence number $\alpha_2(G)$ is the
maximum cardinality of a $2$-independent set in $G$. Chellali and Meddah [{\it
Trees with equal $2$-domination and $2$-independence numbers,} Discussiones
Mathematicae Graph Theory 32 (2012), 263--270] provided a constructive
characterization of trees with equal $2$-domination and $2$-independence
numbers. Their characterization is in terms of global properties of a tree, and
involves properties of minimum $2$-dominating and maximum $2$-independent sets
in the tree at each stage of the construction. We provide a constructive
characterization that relies only on local properties of the tree at each stage
of the construction.


title: Piecewise Empirical Likelihood

abstract:
  Non-parametric methods avoid the problem of having to specify a particular
data generating mechanism, but can be computationally intensive, reducing their
accessibility for large data problems. Empirical likelihood, a non-parametric
approach to the likelihood function, is also limited in application due to the
computational demands necessary. We propose a new approach that combines
multiple non-parametric likelihood-type components to build a data-driven
approximation of the true function. We will examine the theoretical properties
of this piecewise empirical likelihood and demonstrate the computational gains
of this methodology.


title: Computation Tree Logic for Synchronization Properties

abstract:
  We present a logic that extends CTL (Computation Tree Logic) with operators
that express synchronization properties. A property is synchronized in a system
if it holds in all paths of a certain length. The new logic is obtained by
using the same path quantifiers and temporal operators as in CTL, but allowing
a different order of the quantifiers. This small syntactic variation induces a
logic that can express non-regular properties for which known extensions of MSO
with equality of path length are undecidable. We show that our variant of CTL
is decidable and that the model-checking problem is in Delta_3^P = P^{NP^NP},
and is DP-hard. We analogously consider quantifier exchange in extensions of
CTL, and we present operators defined using basic operators of CTL* that
express the occurrence of infinitely many synchronization points. We show that
the model-checking problem remains in Delta_3^P. The distinguishing power of
CTL and of our new logic coincide if the Next operator is allowed in the
logics, thus the classical bisimulation quotient can be used for state-space
reduction before model checking.


title: Inelastic photon scattering via the intracavity Rydberg blockade

abstract:
  Electromagnetically induced transparency (EIT) in a ladder system involving a
Rydberg level is known to yield giant optical nonlinearities for the probe
field, even in the few-photon regime. This enhancement is due to the strong
dipole-dipole interactions between Rydberg atoms and the resulting excitation
blockade phenomenon. In order to study such highly correlated media, ad hoc
models or low-excitation assumptions are generally used to tackle their
dynamical response to optical fields. Here, we study the behaviour of a cavity
Rydberg-EIT setup in the non-equilibrium quantum field formalism, and we obtain
analytic expressions for elastic and inelastic components of the cavity
transmission spectrum, valid up to higher excitation numbers than previously
achieved. This allows us to identify and interpret a polaritonic resonance
structure, to our knowledge unreported so far.


title: Stability in Graphs and Games

abstract:
  We study graphs and two-player games in which rewards are assigned to states,
and the goal of the players is to satisfy or dissatisfy certain property of the
generated outcome, given as a mean payoff property. Since the notion of
mean-payoff does not reflect possible fluctuations from the mean-payoff along a
run, we propose definitions and algorithms for capturing the stability of the
system, and give algorithms for deciding if a given mean payoff and stability
objective can be ensured in the system


title: Introduction to the Rapid Decay property

abstract:
  This is an introduction to the Rapid Decay property, with a survey of known
results and equivalent definitions of this property. We also discuss in details
the easy case when G = Z. Everything in this paper is well-known by different
sets of people.


title:
Interaction-assisted quantum tunneling of a Bose-Einstein condensate out
  of a single trapping well

abstract:
  We experimentally study tunneling of Bose-condensed $^{87}$Rb atoms prepared
in a quasi-bound state and observe a non-exponential decay caused by
interatomic interactions. A combination of a magnetic quadrupole trap and a
thin $1.3\mathrm{\mu m}$ barrier created using a blue-detuned sheet of light is
used to tailor traps with controllable depth and tunneling rate. The escape
dynamics strongly depend on the mean-field energy, which gives rise to three
distinct regimes--- classical spilling over the barrier, quantum tunneling, and
decay dominated by background losses. We show that the tunneling rate depends
exponentially on the chemical potential. Our results show good agreement with
numerical solutions of the 3D Gross-Pitaevskii equation.


title:
Optimizing spectral distribution character of the LEDs to decrease
  discoloring of the collections in museum

abstract:
  For white LEDs used for lighting museums, it is possible to reduce their
effects on the discoloration of exhibits to a great extent by regulating their
spectral distribution so that less lights with 420~470 nm of wavelength which
acts on increasing the span of preservation of exhibits, such as pictures,
color paper and color cloth. For same illumination of radiation of 5000 lx of
white LEDs with different color temperature of about 3000, 3200, 4200 and 6500
K, the density of radiation energy of 420 nm was 34.2, 71.8, 83.1 and 268.3
{\mu}W/cm2, respectively. The discoloration experiment shows that the effects
of discoloration of cold white LEDs was much greater than those of warm white
LEDs.


title:
Anisotropy and interaction effects of strongly strained SrIrO3 thin
  films

abstract:
  Magneto-transport properties of SrIrO$_3$ thin films epitaxially grown on
SrTiO$_3$, using reactive RF sputtering, are investigated. A large anisotropy
between the in-plane and the out-of-plane resistivities is found, as well as a
signature of the substrate cubic to tetragonal transition. Both observations
result from the structural distortion associated to the epitaxial strain. The
low-temperature and field dependences of the Hall number are interpreted as due
to the contribution of Coulomb interactions to weak localization, evidencing
the strong correlations in this material. The introduction of a contribution
from magnetic scatters, in the analysis of magnetoconductance in the weakly
localized regime, is proposed as an alternative to an anomalously large
temperature dependence of the Land\'{e} coefficient.


title:
Systematic estimation of theoretical uncertainties in the calculation of
  the pion-photon transition form factor using light-cone sum rules

abstract:
  We consider the calculation of the pion-photon transition form factor
$F^{\gamma^*\gamma\pi^0}(Q^2)$ within light-cone sum rules focusing attention
to the low-mid region of momenta. The central aim is to estimate the
theoretical uncertainties which originate from a wide variety of sources
related to (i) the relevance of next-to-next-to-leading order radiative
corrections (ii) the influence of the twist-four and the twist-six term (iii)
the sensitivity of the results on auxiliary parameters, like the Borel scale
$M^2$, (iv) the role of the phenomenological description of resonances, and (v)
the significance of a small but finite virtuality of the quasireal photon.
Predictions for $F^{\gamma^*\gamma\pi^0}(Q^2)$ are presented which include all
these uncertainties and found to comply within the margin of experimental error
with the existing data in the $Q^2$ range between 1 and 5 GeV$^2$, thus
justifying the reliability of the applied calculational scheme. This provides a
solid basis for confronting theoretical predictions with forthcoming data
bearing small statistical errors.


title:
Convergence criteria for FI$_\mathcal{W}$-algebras and polynomial
  statistics on maximal tori in type B/C

abstract:
  A result of Lehrer describes a beautiful relationship between topological and
combinatorial data on certain families of varieties with actions of finite
reflection groups. His formula relates the cohomology of complex varieties to
point counts on associated varieties over finite fields. Church, Ellenberg, and
Farb use their representation stability results on the cohomology of flag
manifolds, together with classical results on the cohomology rings, to prove
asymptotic stability for "polynomial" statistics on associated varieties over
finite fields. In this paper we investigate the underlying algebraic structure
of these families' cohomology rings that makes the formulas convergent. We
prove that asymptotic stability holds in general for subquotients of
FI$_\mathcal{W}$-algebras finitely generated in degree at most one, a result
that is in a sense sharp. As a consequence, we obtain convergence results for
polynomial statistics on the set of maximal tori in
$\mathrm{Sp}_{2n}(\overline{F_q})$ and $\mathrm{SO}_{2n+1}(\overline{F_q})$
that are invariant under the Frobenius morphism. Our results also give a new
proof of the stability theorem for invariant maximal tori in
$\mathrm{GL}_n(\overline{F_q})$ due to Church-Ellenberg-Farb.


title: Partial actions: What they are and why we care

abstract:
  In this work, we give a survey of recent developments in the theory of
partial actions of groups and Hopf algebras.


title: On the asymptotics of supremum distribution for some iterated processes

abstract:
  In this paper, we study the asymptotic behavior of supremum distribution of
some classes of iterated stochastic processes $\{X(Y(t)) : t \in [0,
\infty)\}$, where $\{X(t) : t \in \mathbb{R} \}$ is a centered Gaussian process
and $\{Y(t): t \in [0, \infty)\}$ is an independent of $\{X(t)\}$ stochastic
process with a.s. continuous sample paths. In particular, the asymptotic
behavior of $\mathbb{P}\left(\sup_{s \in [0,T]} X(Y(s)) > u\right)$ as $u \to
\infty$, where $T > 0$, as well as $\lim_{u\to\infty} \mathbb{P}\left(\sup_{s
\in [0, h(u)]} X(Y(s)) > u\right)$, for some suitably chosen function $h(u)$
are analyzed. As an illustration, we study the asymptotic behavior of the
supremum distribution of iterated fractional Brownian motion process.


title: Orbits of four young triple-lined multiple systems

abstract:
  Each of the nearby triple systems HIP 7601, 13498, 23824, and 113597 (HD
10800, 18198, 35877, 217389) consists of solar-type dwarfs with comparable
masses, where all three components are resolved spectrally, while the outer
pairs are resolved both visually and spectrally. These stars are relatively
young (between 100 and 600 Myr) and chromospherically active (X-ray sources),
although they rotate slowly. Spectroscopic orbits of the inner subsystems
(periods 19.4, 14.1, 5.6, 20.3 days) and orbits of the outer systems (periods
1.75, 51, 27, 500 yrs, respectively) are determined. For HIP 7601 and 13498,
the combined spectro-interferometric outer orbits produce direct measurement of
masses of all components, allowing comparison with stellar models. The 6708A
lithium line is present and its strength is measured in each component
individually by subtracting the contributions of other components. The inner
and outer orbits of HIP 7601 are nearly circular, likely co-planar, and have a
modest period ratio of 1:33. This study contributes to the characterization of
hierarchical multiplicity in the solar neighborhood and provides data for
testing stellar evolutionary models and chronology.


title: The SSM with Suppressed SUSY Charge

abstract:
  An earlier paper showed that it is possible to write down new SUSY Actions in
which it is not possible to define a Supersymmetry Charge. SUSY is defined in
these new Actions by the fact that they satisfy Master Equations. The new SUSY
Actions are very easy to write down. One simply takes a Chiral SUSY Action,
coupled to Gauge and other Chiral Multiplets, and even SuperGravity, if
desired. Then one creates a new Action from this by exchanging all or part of
the Scalar Field $S$ for a new Zinn Source $J$, and the corresponding part of
the Zinn Source $\Gamma$ for a new Antighost Field $\eta$. Since the original
Action satisfies a Master Equation, this exchange guarantees that the new
Action will satisfy the new Master Equation. As was shown in the earlier paper,
the new multiplets have fewer bosonic degrees of freedom than fermionic degrees
of freedom. This is possible because they do not have a Supercharge.
  The resulting new SSM has no need for Squarks or Sleptons. It does not need
spontaneous breaking of SUSY, so that the cosmological constant problem does
not arise (at least at tree level). It mimics the usual non-supersymmetric
Standard Model very well, and the absence of large flavour changing neutral
currents is natural. There is no need for a hidden sector, or a messenger
sector, or explicit `soft' breaking of SUSY. Spontaneous Gauge Symmetry
Breaking implies the existence of two new very heavy Higgs Bosons with mass
13.4 TeV, slightly smaller than the energy of the LHC at 14 TeV. There is also
a curious set of Gauginos and Higgsinos which have exactly the same masses as
the Higgs and Gauge Bosons. These do not couple to the Quarks and Leptons,
except through the Higgs and Gauge Bosons.


title: Improving Human Action Recognition by Non-action Classification

abstract:
  In this paper we consider the task of recognizing human actions in realistic
video where human actions are dominated by irrelevant factors. We first study
the benefits of removing non-action video segments, which are the ones that do
not portray any human action. We then learn a non-action classifier and use it
to down-weight irrelevant video segments. The non-action classifier is trained
using ActionThread, a dataset with shot-level annotation for the occurrence or
absence of a human action. The non-action classifier can be used to identify
non-action shots with high precision and subsequently used to improve the
performance of action recognition systems.


title: Mode jumping MCMC for Bayesian variable selection in GLMM

abstract:
  Generalized linear mixed models (GLMM) are used for inference and prediction
in a wide range of different applications providing a powerful scientific tool.
An increasing number of sources of data are becoming available, introducing a
variety of candidate explanatory variables for these models. Selection of an
optimal combination of variables is thus becoming crucial. In a Bayesian
setting, the posterior distribution of the models, based on the observed data,
can be viewed as a relevant measure for the model evidence. The number of
possible models increases exponentially in the number of candidate variables.
Moreover, the space of models has numerous local extrema in terms of posterior
model probabilities. To resolve these issues a novel MCMC algorithm for the
search through the model space via efficient mode jumping for GLMMs is
introduced. The algorithm is based on that marginal likelihoods can be
efficiently calculated within each model. It is recommended that either exact
expressions or precise approximations of marginal likelihoods are applied. The
suggested algorithm is applied to simulated data, the famous U.S. crime data,
protein activity data and epigenetic data and is compared to several existing
approaches.


title: Orbits of subsystems in four hierarchical multiple stars

abstract:
  Seven spectroscopic orbits in nearby solar-type multiple stars are presented.
The primary of the chromospherically active star HIP 9642 is a 4.8-day
double-lined pair; the outer 420-yr visual orbit is updated, but remains poorly
constrained. HIP 12780 is a quadruple system consisting of the resolved 6.7-yr
pair FIN 379 Aa,Ab, for which the combined orbit, masses, and orbital parallax
are determined here, and the single-lined binary Ba,Bb with a period of 27.8
days. HIP 28790 is a young quintuple system composed of two close binaries
Aa,Ab and Ba,Bb with periods of 221 and 13 days, respectively, and a single
distant component C. Its subsystem Ba,Bb is peculiar, having the spectroscopic
mass ratio of 0.89 but a magnitude difference of ~2.2 mag. HIP 64478 also
contains five stars: the A-component is a 29-year visual pair with a previously
known 4-day twin subsystem, while the B-component is a contact binary with a
period of 5.8 hours, seen nearly pole-on.


title: Achieving sub-shot-noise sensing at finite temperatures

abstract:
  We investigate sensing of magnetic fields using quantum spin chains at finite
temperature and exploit quantum phase crossovers to improve metrological bounds
on the estimation of the chain parameters. In particular, we analyze the $ XX $
spin chain and show that the magnetic sensitivity of this system is dictated by
its adiabatic magnetic susceptibility, which scales extensively (linearly) in
the number of spins $ N $. Next, we introduce an iterative feedforward protocol
that actively exploits features of quantum phase crossovers to enable
super-extensive scaling of the magnetic sensitivity. Moreover, we provide
experimentally realistic observables to saturate the quantum metrological
bounds. Finally, we also address magnetic sensing in the Heisenberg $ XY $ spin
chain.