title:
Search for a Non-equilibrium Plasma in the Merging Galaxy Cluster Abell
  754

abstract:
  Abell 754 is a galaxy cluster in which an ongoing merger is evident on the
plane of the sky, from the southeast to the northwest. We study the spatial
variation of the X-ray spectra observed with Suzaku along the merging
direction, centering on the Fe Ly-alpha / Fe He-alpha line ratio to search for
possible deviation from ionization equilibrium. Fitting with a single
temperature collisional non-equilibrium plasma model shows that the electron
temperature increases from the southeast to the northwest. The ionization
parameter is consistent with that in equilibrium (n_et>10^{13} s cm^{-3})
except for a specific region with the highest temperature
(kT=13.3^{+1.4}_{-1.1} keV) where n_et=10^{11.6^{+0.6}_{-1.7}} s cm^{-3}. The
elapsed time from the plasma heating estimated from the ionization parameter is
0.36-76 Myr at the 90% confidence level. This time scale is quite short but
consistent with the traveling time of a shock to pass through that region. We
thus interpret that the non-equilibrium ionization plasma in Abell 754 observed
is a remnant of the shock heating in the merger process. We, however, note that
the X-ray spectrum of the specific region where the non-equilibrium is found
can also be fitted with a collisional ionization plasma model with two
temperatures, low kT=4.2^{+4.2}_{-1.5} keV and very high kT > 19.3 keV. The
very high temperature component is alternatively fitted with a power law model.
Either of these spectral models is interpreted as a consequence of the ongoing
merger process as in the case of that with the non-equilibrium ionization
plasma.


title:
Latent class analyisis for reliable measure of inflation expectation in
  the indian public

abstract:
  The main aim of this paper is to inspect the properties of survey based on
households inflation expectations, conducted by Reserve Bank of India. It is
theorized that the respondents answers are exaggerated by extreme response
bias. Latent class analysis has been hailed as a promising technique for
studying measurement errors in surveys, because the model produces estimates of
the error rates associated with a given question of the questionnaire. I have
identified a model with optimum performance and hence categorize the objective
as well as reliable classifiers or otherwise.


title: Kinematical properties of coronal mass ejections

abstract:
  Coronal mass ejections (CMEs) are the most dynamic phenomena in our solar
system. They abruptly disrupt the continuous outflow of solar wind by expelling
huge clouds of magnetized plasma into interplanetary space with velocities
enabling to cross the Sun-Earth distance within a few days. Earth-directed CMEs
may cause severe geomagnetic storms when their embedded magnetic fields and the
shocks ahead compress and reconnect with the Earth's magnetic field. The
transit times and impacts in detail depend on the initial CME velocity, size,
and mass, as well as on the conditions and coupling processes with the ambient
solar wind flow in interplanetary space. The observed CME parameters may be
severly affected by projection effects and the constant changing environmental
conditions are hard to derive. This makes it difficult to fully understand the
physics behind CME evolution, preventing to do a reliable forecast of
Earth-directed events. This short review focusing on observational data, shows
recent methods which were developed to derive the CME kinematical profile for
the entire Sun-Earth distance range as well as studies which were performed to
shed light on the physical processes that CMEs encounter when propagating from
Sun to Earth.


title:
Sampling approach to sparse approximation problem: determining degrees
  of freedom by simulated annealing

abstract:
  The approximation of a high-dimensional vector by a small combination of
column vectors selected from a fixed matrix has been actively debated in
several different disciplines. In this paper, a sampling approach based on the
Monte Carlo method is presented as an efficient solver for such problems.
Especially, the use of simulated annealing (SA), a metaheuristic optimization
algorithm, for determining degrees of freedom (the number of used columns) by
cross validation is focused on and tested. Test on a synthetic model indicates
that our SA-based approach can find a nearly optimal solution for the
approximation problem and, when combined with the CV framework, it can optimize
the generalization ability. Its utility is also confirmed by application to a
real-world supernova data set.

categories: cs.IT cond-mat.dis-nn cond-mat.stat-mech math.IT stat.ME


title:
Phase solitons and domain dynamics in an optically injected
  semiconductor laser

abstract:
  We analyze experimentally and theoretically the spatio-temporal dynamics of a
highly multimode semiconductor laser with coherent optical injection. Due to
the particular geometry of the device (a 1~m long ring cavity), the multimode
dynamics can be resolved in real time and we observe stable chiral solitons and
domain dynamics. The experiment is analyzed in the framework of a set of
effective semiconductor Maxwell-Bloch equations. We analyze the stability of
stationary solutions and simulate both the complete model and a reduced rate
equation model. This allows us to predict domain shrinking and the stability of
only one chiral charge that we ascribe to the finite active medium response
time.


title: Bosonic self-energy functional theory

abstract:
  We derive the self-energy functional theory for bosonic lattice systems with
broken $U(1)$ symmetry by parametrizing the bosonic Baym-Kadanoff effective
action in terms of one- and two-point self-energies. The formalism goes beyond
other approximate methods such as the pseudoparticle variational cluster
approximation, the cluster composite boson mapping, and the Bogoliubov+U
theory. It simplifies to bosonic dynamical-mean field theory when constraining
to local fields, whereas when neglecting kinetic contributions of non-condensed
bosons it reduces to the static mean-field approximation. To benchmark the
theory we study the Bose-Hubbard model on the two- and three-dimensional cubic
lattice, comparing with exact results from path integral quantum Monte Carlo.
We also study the frustrated square lattice with next-nearest neighbor hopping,
which is beyond the reach of Monte Carlo simulations. A reference system
comprising a single bosonic state, corresponding to three variational
parameters, is sufficient to quantitatively describe phase-boundaries, and
thermodynamical observables, while qualitatively capturing the spectral
functions, as well as the enhancement of kinetic fluctuations in the frustrated
case. On the basis of these findings we propose self-energy functional theory
as the omnibus framework for treating bosonic lattice models, in particular, in
cases where path integral quantum Monte Carlo methods suffer from severe sign
problems (e.g. in the presence of non-trivial gauge fields or frustration).
Self-energy functional theory enables the construction of diagrammatically
sound approximations that are quantitatively precise and controlled in the
number of optimization parameters, but nevertheless remain computable by modest
means.


title:
A revised condition for self-gravitational fragmentation of
  protoplanetary disks

abstract:
  Fragmentation of protoplanetary disks due to gravitational instabilities is a
candidate of a formation mechanism of binary stars, brown dwarfs, and gaseous
giant planets. The condition for the fragmentation has been thought that the
disk cooling timescale is comparable to its dynamical timescale. However, some
numerical simulations suggest that the fragmentation does not occur even if the
cooling time is small enough, or the fragmentation can occur even when the
cooling is inefficient. To reveal a realistic condition for fragmentation of
self-gravitating disks, we perform two-dimensional numerical simulations that
take into account the effect of the irradiation of the central star and
radiation cooling of the disk, and precisely investigate the structure of the
spiral arms formed in the protoplanetary disks. We show that the Toomre Q
parameter in the spiral arms is an essential parameter for fragmentation. The
spiral arms fragment only when Q < 0.6 in the spiral arms. We have further
confirmed that this fragmentation condition observed in the numerical
simulations can be obtained from the linear stability analysis for the
self-gravitating spiral arms. These results indicate that the process of
fragmentation of protoplanetary disks is divided into two stages: formation of
the spiral arms in the disks; and fragmentation of the spiral arm. Our work
reduces the condition for the fragmentation of the protoplanetary disks to the
condition of the formation of the spiral arm that satisfies Q < 0.6.


title: Hemi-slant submanifolds of nearly Kaehler manifolds

abstract:
  In the present paper, we study the hemi-slant submanifolds of nearly Kaehler
manifolds. We study the integrability of distributions involved in the
definition of hemi-slant submanifolds. some results are worked out on totally
umbilical hemi-slant submanifolds. we study the cohomology class for hemi-slant
submanifolds of nearly Kaehler manifolds.


title: Design Heuristic for Parallel Many Server Systems under FCFS-ALIS

abstract:
  We study a parallel queueing system with multiple types of servers and
customers. A bipartite graph describes which pairs of customer-server types are
compatible. We consider the service policy that always assigns servers to the
first, longest waiting compatible customer, and that always assigns customers
to the longest idle compatible server if on arrival, multiple compatible
servers are available. For a general renewal stream of arriving customers and
general service time distributions, the behavior of such systems is very
complicated. In particular, the calculation of matching rates, the fraction of
services of customer-server type, is intractable. We suggest through a
heuristic argument that if the number of servers becomes large, the matching
rates are well approximated by matching rates calculated from the tractable
bipartite infinite matching model. We present simulation evidence to support
this heuristic argument, and show how this can be used to design systems with
desired performance requirements.


title: A New Approach to the Classical and Quantum Dynamics of Branes

abstract:
  It is shown that the Dirac-nambu-Goto brane can be described as a point
particle in an infinite dimensional brane space with a particular metric. This
suggests a generalization to brane spaces with arbitrary metric, including the
"flat" metric. Then quantization of such a system is straightforward: it is
just like quantization of a bunch of non interacting particles. This leads us
to a system of a continuous set of scalar fields. For a particular choice of
the metric in the space of fields we find that the classical Dirac-Nambu-Goto
brane theory arises as an effective theory of such an underlying quantum field
theory. Quantization of branes is important for the brane world scenarios, and
thus for "quantum gravity".


title:
Unitary evolution for anisotropic quantum cosmologies: models with
  variable spatial curvature

abstract:
  Contrary to the general belief, there has recently been quite a few examples
of unitary evolution of quantum cosmological models. The present work gives
more examples, namely Bianchi type VI and type II. These examples are important
as they involve varying spatial curvature unlike the most talked about
homogeneous but anisotropic cosmological models like Bianchi I, V and IX. We
exhibit either explicit example of the unitary solutions of the Wheeler-DeWitt
equation, or at least show that a self-adjoint extension is possible.


title:
TANGO: Transparent heterogeneous hardware Architecture deployment for
  eNergy Gain in Operation

abstract:
  The paper is concerned with the issue of how software systems actually use
Heterogeneous Parallel Architectures (HPAs), with the goal of optimizing power
consumption on these resources. It argues the need for novel methods and tools
to support software developers aiming to optimise power consumption resulting
from designing, developing, deploying and running software on HPAs, while
maintaining other quality aspects of software to adequate and agreed levels. To
do so, a reference architecture to support energy efficiency at application
construction, deployment, and operation is discussed, as well as its
implementation and evaluation plans.


title:
Positive and negative effects of social impact on evolutionary
  vaccination game in networks

abstract:
  Preventing infectious disease like flu from spreading to large communities is
one of the most important issues for humans. One effective strategy is
voluntary vaccination, however, there is always the temptation for people
refusing to be vaccinated because once herd immunity is achieved, infection
risk is greatly reduced. In this paper, we study the effect of social impact on
the vaccination behavior resulting in preventing infectious disease in
networks. The evolutionary simulation results show that the social impact has
both positive and negative effects on the vaccination behavior. Especially, in
heterogeneous networks, if the vaccination cost is low, the behavior is more
promoted than the case without social impact. In contrast, if the cost is high,
the behavior is reduced compared to the case without social impact. Moreover,
the vaccination behavior is effective in heterogeneous networks more than in
homogeneous networks. This implies that the social impact puts people at risk
in homogeneous networks. We also evaluate the results from the social cost
related to the vaccination policy.


title:
Genuine quantum signatures in synchronization of anharmonic
  self-oscillators

abstract:
  We study the synchronization of a van der Pol self-oscillator with Kerr
anharmonicity to an external drive. We demonstrate that the anharmonic,
discrete energy spectrum of the quantum oscillator leads to multiple resonances
in both phase locking and frequency entrainment not present in the
corresponding classical system. Strong driving close to these resonances leads
to nonclassical steady-state Wigner distributions. Experimental realizations of
these genuine quantum signatures can be implemented with current technology.


title: The Kepler and Hale observations of V523 Lyr

abstract:
  We present new observations of the cataclysmic variable V523 Lyr, a member of
the open cluster NGC 6791. The Kepler Space telescope obtained photometric
observations of this source and we examine the nearly 3 year long light curve.
The observations show numerous small amplitude outbursts recurring on average
every 33 days, intermittent quasi-periodic oscillations, and a significant
fully coherent period of ~3.8 hr which we identify as the orbital period of the
binary. Contemporaneous optical spectroscopy of V523 Lyr reveals a faint blue
source with broad Balmer absorption lines containing narrow emission cores.
H$\alpha$ is in emission above the continuum. The low amplitude of the
photometric signal and no detected velocity motion suggest a low orbital
inclination. We discuss the properties of V523 Lyr and show that it is a member
of the growing group of anomalous Z Cam type CVs, systems which show stunted
outbursts, light curve standstills, and occasional deep drops in brightness.


title: A pairwise comparison approach to ranking in chess team championships

abstract:
  Chess championships are often organised as a Swiss-system tournament, causing
great challenges in ranking the participants due to the different strength of
schedules and possible circular triads. The paper suggests that pairwise
comparison matrices perform well in similar ranking problems. Some features of
the proposed method are illustrated by the results of the 18th European Team
Chess Championship. The analysis is able to take into account the influence of
different opponents and robust with respect to the scaling technique chosen.
The method is simple to compute as a solution of a linear equation system.


title: Contextual trace refinement for concurrent objects: Safety and progress

abstract:
  Correctness of concurrent objects is defined in terms of safety properties
such as linearizability, sequential consistency, and quiescent consistency, and
progress properties such as wait-, lock-, and obstruction-freedom. These
properties, however, only refer to the behaviours of the object in isolation,
which does not tell us what guarantees these correctness conditions on
concurrent objects provide to their client programs. This paper investigates
the links between safety and progress properties of concurrent objects and a
form of trace refinement for client programs, called contextual trace
refinement. In particular, we show that linearizability together with a minimal
notion of progress are sufficient properties of concurrent objects to ensure
contextual trace refinement, but sequential consistency and quiescent
consistency are both too weak. Our reasoning is carried out in the action
systems framework with procedure calls, which we extend to cope with non-atomic
operations.


title: Geometry of Riccati equations over normed division algebras

abstract:
  This work presents and studies Riccati equations over finite-dimensional
normed division algebras. We prove that a Riccati equation over a
finite-dimensional normed division algebra $A$ is a particular case of
conformal Riccati equation on a Euclidean space and it can be considered as a
curve in a Lie algebra of vector fields $V\simeq\mathfrak{so}(\dim A+1,1)$.
Previous results on known types of Riccati equations are recovered from a new
viewpoint. A new type of Riccati equations, the octonionic Riccati equations,
are extended to the octonionic projective line $\mathbb{O}{\rm P}^1$. As a new
physical application, quaternionic Riccati equations are applied to study
quaternionic Schr\"odinger equations on 1+1 dimensions.


title: Coherence for vectorial waves and majorization

abstract:
  We show that majorization provides a powerful approach to the coherence
conveyed by partially polarized transversal electromagnetic waves. Here we
present the formalism, provide some examples and compare with standard measures
of polarization and coherence of vectorial waves.


title: Hard X-ray flux variations in AGN from NuSTAR

abstract:
  We present here our results on the hour like time scale X-ray flux variations
in a sample of active galactic nuclei using data from the Nuclear Spectroscopic
Telescope Array (NuSTAR). We find that in the 3-79 keV band, BL Lacs are more
variable than flat spectrum radio quasars and Seyfert galaxies. Among Seyferts,
Seyfert 2s are more variable than Seyfert 1s. Also, radio-loud quasars are more
variable in the hard (10-79 keV) band than the soft (3-10 keV) band while,
Seyfert galaxies tend to show more variations in the soft band relative to the
hard band.


title: Big is Fragile: An Attempt at Theorizing Scale

abstract:
  In this paper we characterise the propensity of big capital investments to
systematically deliver poor outcomes as "fragility," a notion suggested by
Nassim Taleb. A thing or system that is easily harmed by randomness is fragile.
We argue that, contrary to their appearance, big capital investments break
easily - i.e. deliver negative net present value - due to various sources of
uncertainty that impact them during their long gestation, implementation, and
operation periods. We do not refute the existence of economies of scale and
scope. Instead we argue that big capital investments have a disproportionate
(non-linear) exposure to uncertainties that deliver poor or negative returns
above and beyond their economies of scale and scope. We further argue that to
succeed, leaders of capital projects need to carefully consider where scaling
pays off and where it does not. To automatically assume that "bigger is
better," which is common in megaproject management, is a recipe for failure.


title: Dynamic Memory Networks for Visual and Textual Question Answering

abstract:
  Neural network architectures with memory and attention mechanisms exhibit
certain reasoning capabilities required for question answering. One such
architecture, the dynamic memory network (DMN), obtained high accuracy on a
variety of language tasks. However, it was not shown whether the architecture
achieves strong results for question answering when supporting facts are not
marked during training or whether it could be applied to other modalities such
as images. Based on an analysis of the DMN, we propose several improvements to
its memory and input modules. Together with these changes we introduce a novel
input module for images in order to be able to answer visual questions. Our new
DMN+ model improves the state of the art on both the Visual Question Answering
dataset and the \babi-10k text question-answering dataset without supporting
fact supervision.


title: Multi-band Variability Analysis of Mrk 421

abstract:
  We have assembled the historical variability data of Mrk 421 at radio 15 GHz,
X-ray and gamma-ray bands, spanning about 6.3, 10.3 and 7.5 yr, respective- ly.
We analyzed the variability by using three methods. The results indicated that
there is a period of 287.6 +- 4.4 days for 15 GHz, 309.5 +- 5.8 days for X- ray
and 283.4+- 4.7 days for gamma-ray, respectively. This period can be reasonably
explained by the nonballistic helical motion of the emitting material. The cor-
relation analysis suggested that the variabilities of radio 15 GHz, X-ray and
0-ray are remarkable correlated, and the emission of radio 15 GHz lags behind
that of X-ray, and the X-ray flux lags behind the gamma-ray. This suggests that
the gamma-ray derives from inverse Compton (IC) scattering of the synchrotron
photons, supporting the synchrotron self-Compton (SSC) model. Moreover, the
time delay between different wavebands could be explained by the shock-in-jet
models, in which a moving emission region produces the radio to gamma-ray
activity, implying that the emission region of gamma-ray is closer to the
center than ones of X-ray and radio emission.


title:
Methods for Stochastic Collection and Replenishment (SCAR) optimisation
  for persistent autonomy

abstract:
  Consideration of resources such as fuel, battery charge, and storage space,
is a crucial requirement for the successful persistent operation of autonomous
systems. The Stochastic Collection and Replenishment (SCAR) scenario is
motivated by mining and agricultural scenarios where a dedicated replenishment
agent transports a resource between a centralised replenishment point to agents
using the resource in the field. The agents in the field typically operate
within fixed areas (for example, benches in mining applications, and fields or
orchards in agricultural scenarios), and the motion of the replenishment agent
may be restricted by a road network. Existing research has typically approached
the problem of scheduling the actions of the dedicated replenishment agent from
a short-term and deterministic angle. This paper introduces a method of
incorporating uncertainty in the schedule optimisation through a novel
prediction framework, and a branch and bound optimisation method which uses the
prediction framework to minimise the downtime of the agents. The prediction
framework makes use of several Gaussian approximations to quickly calculate the
risk-weighted cost of a schedule. The anytime nature of the branch and bound
method is exploited within an MPC-like framework to outperform existing
optimisation methods while providing reasonable calculation times in large
scenarios.


title: Capacity Results for the Multicast Cognitive Interference Channel

abstract:
  The capacity region of the Multicast Cognitive Interference Channel (CIFC) is
investigated. This channel consists of two independent transmitters that wish
to multicast two different messages, each of them to a different set of users.
In addition, one of the transmitters --commonly referred to as the cognitive
transmitter-- has prior non-causal knowledge of both messages to be
transmitted. This scenario combines difficulties and challenges arising in the
Interference Channel, the Broadcast Channel and multicasting communications.
Our aim concerns the derivation of optimal interference mitigation techniques
in such a challenging communication setup. We investigate to this end the
multi-primary CIFC and its dual multi-secondary CIFC under various interference
regimes as an attempt to build a thorough understanding for the more general
setting. It is shown that, for some regimes, well-known coding techniques for
the conventional CIFC remain still optimal in the presence of multicasting.
While in other regimes, evolved encoding and/or decoding strategies are
crucial. A careful use of these coding schemes and new outer bounding
techniques allows us to characterize the capacity region for several classes of
discrete memoryless and Gaussian channels in different interference regimes.


title:
H\"older continuity of Oseledets splittings for semi-invertible operator
  cocycles

abstract:
  For H\"older continuous cocycles over an invertible, Lipschitz base, we
establish the H\"older continuity of Oseledets subspaces on compact sets of
arbitrarily large measure. This extends a result of Ara\'{u}jo, Bufetov, and
Filip by considering possibly noninvertible cocycles, which in addition may
take values in the space of compact operators on a Hilbert space. As a
by-product of our work, we also show that a noninvertible cocycle with
nonvanishing Lyapunov exponents exhibits nonuniformly hyperbolic behaviour (in
the sense of Pesin) on a set of full measure.


title: Short note on the number of 1-ascents in dispersed dyck paths

abstract:
  A dispersed Dyck path (DDP) of length n is a lattice path on $N\times N$ from
(0,0) to (n,0) in which the following steps are allowed: "up" (x, y) $\to$
(x+1, y+1); "down" (x, y) $\to$ (x+1, y-1); and "right" (x,0) $\to$ (x+1,0). An
ascent in a DDP is an inclusion-wise maximal sequence of consecutive up steps.
A 1-ascent is an ascent consisting of exactly 1 up step. We give a closed
formula for the total number of 1-ascents in all dispersed Dyck paths of length
n, A191386 in Sloane's OEIS. Previously, only implicit generating function
relations and asymptotics were known.


title:
Exploring the Stability and Dynamics of Dipolar Matter-Wave Dark
  Solitons

abstract:
  We study the stability, form and interaction of single and multiple dark
solitons in quasi-one-dimensional dipolar Bose-Einstein condensates. The
solitons are found numerically as stationary solutions in the moving frame of a
non-local Gross Pitaevskii equation, and characterized as a function of the key
experimental parameters, namely the ratio of the dipolar atomic interactions to
the van der Waals interactions, the polarization angle and the condensate
width. The solutions and their integrals of motion are strongly affected by the
phonon and roton instabilities of the system. Dipolar matter-wave dark solitons
propagate without dispersion, and collide elastically away from these
instabilities, with the dipolar interactions contributing an additional
repulsion or attraction to the soliton-soliton interaction. However, close to
the instabilities, the collisions are weakly dissipative.


title: Estimating Non-Simplified Vine Copulas Using Penalized Splines

abstract:
  Vine copulas (or pair-copula constructions) have become an important tool for
high-dimensional dependence modeling. Typically, so called simplified vine
copula models are estimated where bivariate conditional copulas are
approximated by bivariate unconditional copulas. We present the first
non-parametric estimator of a non-simplified vine copula that allows for
varying conditional copulas using penalized hierarchical B-splines. Throughout
the vine copula, we test for the simplifying assumption in each edge,
establishing a data-driven non-simplified vine copula estimator. To overcome
the curse of dimensionality, we approximate conditional copulas with more than
one conditioning argument by a conditional copula with the first principal
component as conditioning argument. An extensive simulation study is conducted,
showing a substantial improvement in the out-of-sample Kullback-Leibler
divergence if the null hypothesis of a simplified vine copula can be rejected.
We apply our method to the famous uranium data and present a classification of
an eye state data set, demonstrating the potential benefit that can be achieved
when conditional copulas are modeled.


title:
Representations of virtual braids by automorphisms and virtual knot
  groups

abstract:
  In the present paper the representation of the virtual braid group $VB_n$
into the automorphism group of free product of the free group and free abelian
group is constructed. This representation generalizes the previously
constructed ones. The fact that these already known representations are not
faithful for $n \geq 4$ is verified. Using representations of $VB_n$, the
virtual link group is defined. Also representations of welded braid group
$WB_n$ are constructed and the welded link group is defined.


title: On the Chow ring of certain rational cohomology tori

abstract:
  Let $f: X \rightarrow A$ be an abelian cover from a complex algebraic variety
with quotient singularities to an abelian variety. We show that $f^*$ induces
an isomorphism between the rational cohomology rings $H^\bullet(A, \mathbb{Q})$
and $H^\bullet(X, \mathbb{Q})$ if and only if $f^*$ induces an isomorphism
between the Chow rings with rational coefficients
$\mathrm{CH}^\bullet(A)_{\mathbb{Q}}$ and
$\mathrm{CH}^\bullet(X)_{\mathbb{Q}}$.


title:
Splines are Universal Solutions of Linear Inverse Problems with
  Generalized-TV regularization

abstract:
  Splines come in a variety of flavors that can be characterized in terms of
some differential operator L. The simplest piecewise-constant model corresponds
to the derivative operator. Likewise, one can extend the traditional notion of
total variation by considering more general operators than the derivative. This
leads us to the definition of the generalized Beppo-Levi space M, which is
further identified as the direct sum of two Banach spaces. We then prove that
the minimization of the generalized total variation (gTV) over M, subject to
some arbitrary (convex) consistency constraints on the linear measurements of
the signal, admits nonuniform L-spline solutions with fewer knots than the
number of measurements. This shows that non-uniform splines are universal
solutions of continuous-domain linear inverse problems with LASSO, L1, or
TV-like regularization constraints. Remarkably, the spline-type is fully
determined by the choice of L and does not depend on the actual nature of the
measurements.


title:
Achieving accurate ionization potential of semiconductors by the
  efficient Kohn-Sham scheme of density functional theory

abstract:
  Despite of its huge successes in vast amount of applications, the Kohn-Sham
scheme of density functional theory (DFT-Kohn-Sham) has not been able to get
reliable ionization potentials (IP) for semiconductors, due to self-interaction
error in the local density approximation (LDA) and generalized gradient
approximations (GGA), and the difficulty of using asymptotically long-ranged
potentials for surface calculations. An approximate optimize effective
potential (OEP), the Becke-Johnson'06 exchange, is used to explore the
capability of OEP to calculate semiconductor IP with a surface technique
suitable for both short- and long-ranged potentials. Combined with the LDA
correlation, the approximate OEP has achieved an IP accuracy for 17
semiconductors which is similar to the much more sophisticated $GW$
approximation (GWA), with the computational cost of only LDA/GGA. For the first
time, this opens the way for systematic calculation of semiconductor IP's by
the DFT-Kohn-Sham scheme. The long-range part of the $v_{xc}$ is not as
important for solid surface as for atoms and molecules since the wave functions
are mainly bound to the slab while less exposed to the asymptotic region.
Nevertheless, it contributes significantly to the total IP and therefore shall
not be simply ignored. Without including its effects, it is unlikely that the
same GWA procedure could achieve universally accurate band gaps and accurate
IP's at the same time, as is indeed seen in practical calculations.


title:
Immunity, Improving and Retrieving the lost entanglement of accelerated
  qubit-qutrit system via local Filtering

abstract:
  The possibility of immunized and improving the entanglement of accelerated
systems via local filtering is discussed. The maximum bounds of entanglement
depend on the dimensions of the accelerated and the filtered subsystems. If the
small dimensional subsystem is accelerated and the large dimensional subsystem
is filtered, one can get a long-lived entanglement. Moreover, if the larger
subsystem is accelerated, then by filtering any subsystem, the upper bounds of
entanglement of the filtered state are larger then that for the initial
states.For any accelerated subsystem, the entanglement always increases as the
filter strength of the large dimensional subsystem increases.


title:
Formation of positron-atom bound states in collisions between Rydberg Ps
  and neutral atoms

abstract:
  Predicted twenty years ago, positron binding to neutral atoms has not yet
been observed experimentally. A new scheme is proposed to detect positron-atom
bound states by colliding Rydberg positronium (Ps) with neutral atoms.
Estimates of the charge-transfer reaction cross section are obtained using the
first Born approximation for a selection of neutral atom targets and a wide
range of incident Ps energies and principal quantum numbers. We also estimate
the corresponding Ps ionization cross section. The accuracy of the calculations
is tested by comparison with earlier predictions for Ps charge transfer in
collisions with hydrogen and antihydrogen. We describe an existing Rydberg Ps
beam suitable for producing positron-atom bound states and estimate signal
rates based on the calculated cross sections and realistic experimental
parameters. We conclude that the proposed methodology is capable of producing
such states and of testing theoretical predictions of their binding energies.


title:
Normalization Propagation: A Parametric Technique for Removing Internal
  Covariate Shift in Deep Networks

abstract:
  While the authors of Batch Normalization (BN) identify and address an
important problem involved in training deep networks-- Internal Covariate
Shift-- the current solution has certain drawbacks. Specifically, BN depends on
batch statistics for layerwise input normalization during training which makes
the estimates of mean and standard deviation of input (distribution) to hidden
layers inaccurate for validation due to shifting parameter values (especially
during initial training epochs). Also, BN cannot be used with batch-size 1
during training. We address these drawbacks by proposing a non-adaptive
normalization technique for removing internal covariate shift, that we call
Normalization Propagation. Our approach does not depend on batch statistics,
but rather uses a data-independent parametric estimate of mean and
standard-deviation in every layer thus being computationally faster compared
with BN. We exploit the observation that the pre-activation before Rectified
Linear Units follow Gaussian distribution in deep networks, and that once the
first and second order statistics of any given dataset are normalized, we can
forward propagate this normalization without the need for recalculating the
approximate statistics for hidden layers.


title:
Inner-shell photodetachment from Si- negative ion: strong effect of
  many-electron correlations

abstract:
  The first theoretical investigation on the inner-shell single-photodetachment
from the Si- negative ion is presented. The partial and total cross sections,
the photoelectron phaseshifts, and the parameters of angular anisotropy are
calculated in the framework of Many-Body Theory for L-shell photodetachment
from Si- ion in the experimentally accessible range of photon energies (7.5-14
Ry). Comparison is made between the calculations of the response of the ionic
many-electron system Si- to an electromagnetic field at the different levels of
approximation: the "frozen-field" Random Phase Approximation with Exchange
(RPAE), and the static relaxation approximation. The optimal analysis is made
when the dynamic relaxation and polarization are included within the Dyson
Equation Method (DEM) simultaneously with the RPAE corrections (RPAE&DEM
approach). It is predicted that the photoexcitation to a resonance state of
complex "shape-Feschbach" nature in the open p-shell reveals itself as a
prominent resonance structure in the photodetachment cross sections in the
energy range of the 2s and 2p inner shell thresholds similar to that in 1s
inner-shell photodetachment from C- (J.Phys.B 39, 1379, 2006). The
photodetachment dynamical characteristics clearly demonstrate the significance
of all the considered many-electron correlations within the RPAE&DEM approach,
however the total photodetachment cross section is dominated by a strong
resonance peak just after the 2s threshold. Dynamical relaxation (screening) is
identified as a decisive factor in the formation of this resonance.


title: Super-Additivity and Entanglement Assistance in Quantum Reading

abstract:
  Quantum information theory determines the maximum rates at which information
can be transmitted through physical systems described by quantum mechanics.
Here we consider the communication protocol known as quantum reading. Quantum
reading is a protocol for retrieving the information stored in a digital memory
by using a quantum probe, e.g., shining quantum states of light to read an
optical memory. In a variety of situations using a quantum probe enhances the
performances of the reading protocol in terms of fidelity, data density and
energy dissipation. Here we review and characterize the quantum reading
capacity of a memory model, defined as the maximum rate of reliable reading. We
show that, like other quantities in quantum information theory, the quantum
reading capacity is super-additive. Moreover, we determine conditions under
which the use of an entangled ancilla improves the performance of quantum
reading.


title: Local and global dynamics in polypropylene glycol / silica composites

abstract:
  The local segmental and global dynamics of a series of polypropylene glycol /
silica nanocomposites were studied using rheometry and mechanical and
dielectric spectroscopies. The particles cause substantial changes in the
rheology, including higher viscosities that become non-Newtonian and the
appearance of stress overshoots in the transient shear viscosity. However, no
change was observed in the mean relaxation times for either the segmental or
normal mode dynamics measured dielectrically. This absence of an effect of the
particles is due to masking of the interfacial response by polymer chains
remote from the particles. When the unattached polymer was extracted to isolate
the interfacial material, very large reductions in the relaxation times were
measured. This speeding up of the dynamics is due in part to the reduced
density at the interface, presumably a consequence of poorer packing of
tethered chains. In addition, binding of the ether oxygens of the polypropylene
glycol chains truncates the normal mode, which shifts the corresponding
relaxation peak to higher frequencies.


title:
Evidence of the stability of Mo_{2}TiAlC_{2} from first principles
  calculations and its thermodynamical and optical properties

abstract:
  The elastic, thermodynamic, and optical properties of Mo_{2}TiAlC_{2} are
investigated by first-principles calculations. Our results indicate that the a
axis is stiffer than c axis within 0~100 GPa. Elastic constants calculations
predict the large stability range of Mo_{2}TiAlC_{2} under pressure. Several
important thermodynamic properties are discussed detailedly, including the
Debye temperature, thermal expansion coefficient, and heat capacity etc. The
bonding properties are studied from the elastic quantities and electronic
properties. The electronic properties are investigated, including the energy
band structure, density of states, and so on. The evidence of the instability
of Mo_{3}AlC_{2} and stability of Mo_{2}TiAlC_{2} are successfully obtained.


title:
Implementation of a Direct Coupling Coherent Quantum Observer including
  Observer Measurements

abstract:
  This paper considers the problem of constructing a direct coupling quantum
observer for a quantum harmonic oscillator system. The proposed observer is
shown to be able to estimate one but not both of the plant variables and
produces a measureable output using homodyne detection.


title:
Conditions for optimal input states for discrimination of quantum
  channels

abstract:
  We find optimality conditions for testers in discrimination of quantum
channels. These conditions are obtained using semidefinite programming and are
similar to optimality conditions for POVMs obtained by Holevo for ensembles of
quantum states. We get a simple condition for existence of an optimal tester
with any given input state with maximal Schmidt rank, in particular with a
maximally entangled input state and we show the pitfalls of using input states
with not maximal Schmidt rank. In case when maximally entangled state is not
the optimal input state an error estimate is obtained. The results for
maximally entangled input state are applied to covariant channels, qubit
channels, unitary channels and simple projective measurements.


title:
Quantum-chemical perspective of nanoscale Raman spectroscopy with
  three-dimensional phonon confinement model

abstract:
  Raman spectroscopy of crystalline/molecular systems is well backed with
quantum chemical calculations and group theory, making it a unique
characterization tool. For the "intermediate" case of nanoscale systems,
however, the use of Raman spectroscopy is limited by the lack of such
theoretical bases. Here, we suggest to couple a scaled quantum-mechanical (SQM)
calculation with the phonon confinement model (PCM) to construct a universal
and physically consistent basis for nanoscale Raman spectroscopy. Unlike the
commonly used one-dimensional dispersion PCM, we take into account the
confinement along all the three dimensions of the k-space. We apply it to
diamond nanoparticles of sub-50nm size, a system with pronounced anisotropy of
dispersion for which the use of three-dimensional dispersion is a requisite.
The model excellently reproduces size-sensitive spectral features, including
the peak position, bandwidth and asymmetry of the sp3 C-C Raman band. This
fundamental approach can be easily generalized to other nanocrystalline solids
to hopefully contribute the future development of quantitative nanoscale Raman
spectroscopy.


title: The Strong Nullstellensatz for Certain Normed Algebras

abstract:
  Consider the polynomial ring in any finite number of variables over the
complex numbers, endowed with the $\ell_1$-norm on the system of coefficients.
Its completion is the Banach algebra of power series that converge absolutely
on the closed polydisc. Whereas the strong Hilbert Nullstellensatz does not
hold for Banach algebras in general, we show that it holds for ideals in the
polynomial ring that are closed for the indicated norm. Thus the corresponding
statement holds at least partially for the associated Banach algebra. We also
describe the closure of an ideal in small cases.


title: Cubic graphs and related triangulations on orientable surfaces

abstract:
  Let $\mathbb{S}_g$ be the orientable surface of genus $g$. We show that the
number of vertex-labelled cubic multigraphs embeddable on $\mathbb{S}_g$ with
$2n$ vertices is asymptotically $c_g n^{5(g-1)/2-1}\gamma^{2n}(2n)!$, where
$\gamma$ is an algebraic constant and $c_g$ is a constant depending only on the
genus $g$. We also derive an analogous result for simple cubic graphs and
weighted cubic multigraphs. Additionally we prove that a typical cubic
multigraph embeddable on $\mathbb{S}_g$, $g\ge 1$, has exactly one non-planar
component.


title:
Searching for a magnetic field in Wolf-Rayet stars using FORS2
  spectropolarimetry

abstract:
  To investigate if magnetic fields are present in Wolf-Rayet stars, we
selected a few stars in the Galaxy and one in the Large Magellanic Cloud (LMC).
We acquired low-resolution spectropolarimetric observations with the ESO FORS2
instrument during two different observing runs. During the first run in visitor
mode, we observed the LMC Wolf-Rayet star BAT99 7 and the stars WR6, WR7, WR18,
and WR23 in our Galaxy. The second run in service mode was focused on
monitoring the star WR6. Linear polarization was recorded immediately after the
observations of circular polarization. During our visitor observing run, the
magnetic field for the cyclically variable star WR6 was measured at a
significance level of 3.3sigma (<B_z> = 258+-78G). Among the other targets, the
highest value for the longitudinal magnetic field, <B_z> = 327+-141G, was
measured in the LMC star BAT99 7. Spectropolarimetric monitoring of the star
WR6 revealed a sinusoidal nature of the <B_z> variations with the known
rotation period of 3.77d, significantly adding to the confidence in the
detection. The presence of the rotation-modulated magnetic variability is also
indicated in our frequency periodogram. The reported field magnitude suffers
from significant systematic uncertainties at the factor 2 level, in addition to
the quoted statistical uncertainties, owing to the theoretical approach used to
characterize it. Linear polarization measurements showed no line effect in the
stars, apart from WR6. BAT99 7, WR7, and WR,23 do not show variability of the
linear polarization over two nights.


title: A Generalization of the Power Law Distribution with Nonlinear Exponent

abstract:
  The power law distribution is usually used to fit data in the upper tail of
the distribution. However, commonly it is not valid to model data in all the
range. In this paper, we present a new family of distributions, the so-called
Generalized Power Law (GPL), which can be useful for modeling data in all the
range and possess power law tails. To do that, we model the exponent of the
power law using a nonlinear function which depends on data and two parameters.
Then, we provide some basic properties and some specific models of that new
family of distributions. After that, we study a relevant model of the family,
with special emphasis on the quantile and hazard functions, and the
corresponding estimation and testing methods. Finally, as an empirical
evidence, we study how the debt is distributed across municipalities in Spain.
We check that power law model is only valid in the upper tail; we show
analytically and graphically the competence of the new model with municipal
debt data in the whole range; and we compare the new distribution with other
well-known distributions including the Lognormal, the Generalized Pareto, the
Fisk, the Burr type XII and the Dagum models.


title: Computing the Power Distribution in the IMF

abstract:
  The International Monetary Fund is one of the largest international
organizations using a weighted voting system. The weights of its 188 members
are determined by a fixed amount of basic votes plus some extra votes for
so-called Special Drawing Rights (SDR). On January 26, 2016, the conditions for
the SDRs were increased at the 14th General Quota Review, which drastically
changed the corresponding voting weights. However, since the share of voting
weights in general is not equal to the influence, of a committee member on the
committees overall decision, so-called power indices were introduced. So far
the power distribution of the IMF was only computed by either approximation
procedures or smaller games than then entire Board of Governors consisting of
188 members. We improve existing algorithms, based on dynamic programming, for
the computation of power indices and provide the exact results for the IMF
Board of Governors before and after the increase of voting weights. Tuned
low-level details of the algorithms allow the repeated routine with sparse
computational resources and can of course be applied to other large voting
bodies. It turned out that the Banzhaf power shares are rather sensitive to
changes of the quota.


title: Computational Aspects of Private Bayesian Persuasion

abstract:
  We study computational questions in a game-theoretic model that, in
particular, aims to capture advertising/persuasion applications such as viral
marketing. Specifically, we consider a multi-agent Bayesian persuasion model
where an informed sender (marketer) tries to persuade a group of agents
(consumers) to adopt a certain product. The quality of the product is known to
the sender, but it is unknown to the agents. The sender is allowed to commit to
a signaling policy where she sends a private signal---say, a viral marketing
ad---to every agent. This work studies the computation aspects of finding a
signaling policy that maximizes the sender's revenue.
  We show that if the sender's utility is a submodular function of the set of
agents that adopt the product, then we can efficiently find a signaling policy
whose revenue is at least (1-1/e) times the optimal. We also prove that
approximating the sender's optimal revenue by a factor better than (1-1/e) is
NP-hard and, hence, the developed approximation guarantee is essentially tight.
When the senders' utility is a function of the number of agents that adopt the
product (i.e., the utility function is anonymous), we show that an optimal
signaling policy can be computed in polynomial time. Our results are based on
an interesting connection between the Bayesian persuasion problem and the
evaluation of the concave closure of a set function.


title: Approximate Relational Hoare Logic for Continuous Random Samplings

abstract:
  Approximate relational Hoare logic (apRHL) is a logic for formal verification
of the differential privacy of databases written in the programming language
pWHILE. Strictly speaking, however, this logic deals only with discrete random
samplings. In this paper, we define the graded relational lifting of the
subprobabilistic variant of Giry monad, which described differential privacy.
We extend the logic apRHL with this graded lifting to deal with continuous
random samplings. We give a generic method to give proof rules of apRHL for
continuous random samplings.


title: Sheaves are the canonical datastructure for sensor integration

abstract:
  A sensor integration framework should be sufficiently general to accurately
represent all information sources, and also be able to summarize information in
a faithful way that emphasizes important, actionable information. Few
approaches adequately address these two discordant requirements. The purpose of
this expository paper is to explain why sheaves are the canonical data
structure for sensor integration and how the mathematics of sheaves satisfies
our two requirements. We outline some of the powerful inferential tools that
are not available to other representational frameworks.


title:
Regge spectra of excited mesons, harmonic confinement and QCD vacuum
  structure

abstract:
  An approach to QCD vacuum as a medium describable in terms of statistical
ensemble of almost everywhere homogeneous Abelian (anti-)self-dual gluon fields
is briefly reviewed. These fields play the role of the confining medium for
color charged fields as well as underline the mechanism of realization of
chiral $SU_{\rm L}(N_f)\times SU_{\rm R}(N_f)$ and $U_A(1)$ symmetries.
Hadronization formalism based on this ensemble leads to manifestly defined
quantum effective meson action. Strong, electromagnetic and weak interactions
of mesons are represented in the action in terms of nonlocal $n$-point
interaction vertices given by the quark-gluon loops averaged over the
background ensemble. New systematic results for the mass spectrum and decay
constants of radially excited light, heavy-light mesons and heavy quarkonia are
presented. Interrelation between the present approach, models based on ideas of
soft wall AdS/QCD, light front holographic QCD, and the picture of harmonic
confinement is outlined.


title: The thermal instability of the warm absorber in NGC 3783

abstract:
  We model the observed X-ray spectral continuum shape, ionic column densities,
and absorption measure distribution (AMD) of the warm absorber in the Seyfert
galaxy NGC 3783. We assume a photo-ionized medium with a uniform total
(gas+radiation) pressure. The irradiation causes the wind to be radiation
pressure compressed (RPC). We compare the observational characteristics derived
from the 900 ksec Chandra observation to radiative transfer computations in
pressure equilibrium using the radiative transfer code TITAN. We explore
different values of the ionization parameter xi of the incident flux and adjust
the hydrogen-equivalent column density, N_H0 of the warm absorber to match the
observed soft X-ray continuum. We derive theoretical column densities for a
broad range of ionic species of iron and neon and an AMD that we compare to the
observations. We find an extension of the degeneracy between xi and N_H0 for
the constant pressure models previously discussed for NGC 3783. Including the
ionic column densities of iron and neon in the comparison between observations
and data we conclude that a range of ionization parameters between 4000 and
8000 ergs cm/s is preferred. For the first time, we present theoretical AMD for
a constant pressure wind in NGC 3783 that correctly reproduces the observed
level and is in approximate agreement with the observational appearance of an
instability region. Using a variety of observational indicators, we confirm
that the X-ray outflow of NGC 3783 can be described as an RPC medium in
pressure equilibrium. The observed AMD agrees with a uniformly hot or a
uniformly cold thermal state. The measured ionic column densities suggest that
the wind tends to the uniformly cold thermal state. The occurrence of thermal
instability in the warm absorber model may depend on the computational method
and the spatial scale on which the radiative transfer is solved.


title: Intrinsic Optical Bistability in a Strongly-Driven Rydberg Ensemble

abstract:
  We observe and characterize intrinsic optical bistability in a dilute Rydberg
vapor. The bistability is characterized by sharp jumps between states of low
and high Rydberg occupancy with jump up and down positions displaying
hysteresis depending on the direction in which the control parameter is
changed. We find that the shift in frequency of the jump point scales with the
fourth power of the principal quantum number. Also, the width of the hysteresis
window increases with increasing principal quantum number, before reaching a
peak and then closing again. The experimental results are consistent with
predictions from a simple theoretical model based on semiclassical
Maxwell-Bloch equations including the effect of broadening and frequency
shifts. These results provide insight to the dynamics of driven dissipative
systems.


title: Sequential ranking under random semi-bandit feedback

abstract:
  In many web applications, a recommendation is not a single item suggested to
a user but a list of possibly interesting contents that may be ranked in some
contexts. The combinatorial bandit problem has been studied quite extensively
these last two years and many theoretical results now exist : lower bounds on
the regret or asymptotically optimal algorithms. However, because of the
variety of situations that can be considered, results are designed to solve the
problem for a specific reward structure such as the Cascade Model. The present
work focuses on the problem of ranking items when the user is allowed to click
on several items while scanning the list from top to bottom.


title: Separability of test fields equations on the C-metric background

abstract:
  In the Kerr-Newman spacetime the Teukolsky master equation, governing the
fundamental test fields, is of great importance. We derive an analogous master
equation for the non-rotating C-metric which encompass massless Klein-Gordon
field, neutrino field, Maxwell field, Rarita-Schwinger field and gravitational
perturbations. This equation is shown to be separable in terms of "accelerated
spin weighted spherical harmonics". It is shown that, contrary to ordinary spin
weighted spherical harmonics, the "accelerated" ones are different for
different spins. In some cases, the equation for eigenfunctions and eigenvalues
are explicitly solved.


title:
Unveiling the radio counterparts of two binary AGN candidates:
  J1108+0659 and J1131-0204

abstract:
  The sources SDSS\,J113126.08-020459.2 and SDSS\,J110851.04+065901.4 are two
double-peaked [O III] emitting AGN, identified as candidate binary AGNs by
optical and near infrared (NIR) observations. We observed the two sources with
high resolution Very Long Baseline Interferometry (VLBI) using the European
VLBI Network at 5\,GHz, reduced VLA observations at three frequencies available
for one of the sources, and used archival HST observations.
  For the source SDSS\,J113126.08-020459.2, the VLBI observations detected only
one single compact component associated with the eastern NIR nucleus. In
SDSS\,J110851.04+065901.4, the VLBI observations did not detect any compact
components, but the VLA observations allowed us to identify a possible compact
core in the region of the north-western optical/NIR nucleus. In this source we
find kpc-scale extended radio emission that is spatially coincident to the
ultraviolet continuum and to the extended emission narrow line region. The UV
continuum is significantly obscured since the amount of extended radio emission
yields a star formation rate of about 110 \msunyr, which is an order of
magnitude larger than implied by the observed ultraviolet emission.
  Our analysis confirms the presence of only one AGN in the two candidate
binary AGNs.


title:
Modelling the number density of Halpha emitters for future spectroscopic
  near-IR space missions

abstract:
  The future space missions Euclid and WFIRST-AFTA will use the Halpha emission
line to measure the redshifts of tens of millions of galaxies. The Halpha
luminosity function at z>0.7 is one of the major sources of uncertainty in
forecasting cosmological constraints from these missions. We construct unified
empirical models of the Halpha luminosity function spanning the range of
redshifts and line luminosities relevant to the redshift surveys proposed with
Euclid and WFIRST-AFTA. By fitting to observed luminosity functions from Halpha
surveys, we build three models for its evolution. Different fitting
methodologies, functional forms for the luminosity function, subsets of the
empirical input data, and treatment of systematic errors are considered to
explore the robustness of the results. Functional forms and model parameters
are provided for all three models, along with the counts and redshift
distributions up to z~2.5 for a range of limiting fluxes (F_Halpha>0.5 - 3 x
10^-16 erg cm^-2 s^-1) that are relevant for future space missions. For
instance, in the redshift range 0.90<z<1.8, our models predict an available
galaxy density in the range 7700--13300 and 2000--4800 deg^-2 respectively at
fluxes above F_Halpha>1 and 2 x 10^-16 erg cm^-2 s^-1, and 32000--48000 for
F_Halpha>0.5 x 10^-16 erg cm^-2 s^-1 in the extended redshift range 0.40<z<1.8.
We also consider the implications of our empirical models for the total Halpha
luminosity density of the Universe, and the closely related cosmic star
formation history.


title:
Extensions of associative and Lie algebras via Gr\"obner-Shirshov bases
  method

abstract:
  Let $\mathfrak{a},\mathfrak{b},\mathfrak{e}$ be algebras over a field $k$.
Then $\mathfrak{e}$ is an extension of $\mathfrak{a}$ by $\mathfrak{b}$ if
$\mathfrak{a}$ is an ideal of $\mathfrak{e}$ and $\mathfrak{b}$ is isomorphic
to the quotient algebra $\mathfrak{e}/\mathfrak{a}$. In this paper, by using
Gr\"obner-Shirshov bases theory for associative (resp. Lie) algebras, we give
complete characterizations of associative (resp. Lie) algebra extensions of
$\mathfrak{a}$ by $\mathfrak{b}$, where $\mathfrak{b}$ is presented by
generators and relations.


title: Nominal Automata with Name Binding

abstract:
  Automata models for data languages (i.e. languages over infinite alphabets)
often feature either global or local freshness operators. We show that Bollig
et al.'s session automata, which focus on global freshness, are equivalent to
regular nondeterministic nominal automata (RNNA), a natural nominal automaton
model with explicit name binding that has appeared implicitly in the semantics
of nominal Kleene algebra (NKA), an extension of Kleene algebra with name
binding. The expected Kleene theorem for NKA is known to fail in one direction,
i.e. there are nominal languages that can be accepted by an RNNA but are not
definable in NKA; via session automata, we obtain a full Kleene theorem for
RNNAs for an expression language that extends NKA with unscoped name binding.
Based on the equivalence with RNNAs, we then slightly rephrase the known
equivalence checking algorithm for session automata. Reinterpreting the data
language semantics of name binding by unrestricted instead of clean
alpha-equivalence, we obtain a local freshness semantics as a quotient of the
global freshness semantics. Under local freshness semantics, RNNAs turn out to
be equivalent to a natural subclass of Bojanczyk et al.'s nondeterministic
orbit-finite automata. We establish decidability of inclusion under local
freshness by modifying the RNNA-based algorithm; in summary, we obtain a
formalism for local freshness in data languages that is reasonably expressive
and has a decidable inclusion problem.


title:
Breather transition dynamics, Peregrine combs/walls and modulation
  instability in a variable-coefficient nonlinear Schr\"odinger equation with
  higher-order effects

abstract:
  We study a variable-coefficient nonlinear Schr\"odinger (vc-NLS) equation
with higher-order effects. We show that the breather solution can be converted
into four types of nonlinear waves on constant backgrounds including the
multi-peak solitons, antidark soliton, periodic wave and W-shaped soliton. The
transition condition requiring the group velocity dispersion (GVD) and
third-order dispersion (TOD) to scale linearly is obtained analytically. We
display several kinds of elastic interactions between the transformed nonlinear
waves. We discuss the dispersion management of multi-peak soliton, which
indicates that the GVD coefficient controls the number of peaks of the wave
while the TOD coefficient has compression effect. The gain or loss has
influence on the amplitudes of the multi-peak soliton. We further derive the
breather multiple births by using multiple compression points of Akhmediev
breathers in optical fiber systems with periodic dispersion. The number of ABs
depends on the amplitude of the modulation but not on its wavelength, which
affects their separation distance. In the limiting case, the breather multiple
births reduce to the Peregrine combs. We discuss the effects of TOD coefficient
on the spatiotemporal characteristics of Peregrine combs. When the amplitude of
the modulation is equal to 1, the Peregrine comb is converted into a Peregrine
wall that can be seen as intermediate state between rogue wave and W-shaped
soliton. We finally find that the modulational stability regions with zero
growth rate coincide with the transition condition using rogue wave
eigenvalues. Our results could be useful for the experimental control and
manipulation of the formation of generalized Peregrine rogue waves in diverse
physical systems modeled by vc-NLS equation with higher-order effects.


title:
Effects of Thermal Fluctuations on the Thermodynamics of Modified
  Hayward Black Hole

abstract:
  In this work, we analyze the effects of thermal fluctuations on the
thermodynamics of a modified Hayward black hole. These thermal fluctuations
will produce correction terms for various thermodynamic quantities like
entropy, pressure, inner energy and specific heats. We also investigate the
effect of these correction terms on the first law of thermodynamics. Finally,
we study the phase transition for the modified Hayward black hole. It is
demonstrated that the modified Hayward black hole is stable even after the
thermal fluctuations are taken into account, as long as the event horizon is
larger than a certain critical value.


title: Almost invariance of distributions for random walks on groups

abstract:
  We study the neighborhoods of a typical point $Z_n$ visited at $n$-th step of
a random walk, determined by the condition that the transition probabilities
stay close to $\mu^{*n}(Z_n)$. If such neighborhood contains a ball of radius
$C \sqrt{n}$, we say that the random walk has almost invariant transition
probabilities. We prove that simple random walks on wreath products of
$\mathbb{Z}$ with finite groups have almost invariant distributions. A weaker
version of almost invariance implies a necessary condition of Ozawa's criterion
for the property $H_{\rm FD}$. We define and study the radius of almost
invariance, we estimate this radius for random walks on iterated wreath
products and show this radius can be asymptotically strictly smaller than
$n/L(n)$, where $L(n)$ denotes the drift function of the random walk. We show
that the radius of individual almost invariance of a simple random walk on the
wreath product of $\mathbb{Z}^2$ with a finite group is asymptotically strictly
larger than $n/L(n)$. Finally, we show the existence of groups such that the
radius of almost invariance is smaller than a given function, but remains
unbounded. We also discuss possible limiting distribution of ratios of
transition probabilities on non almost invariant scales.


title:
High frequency oscillations of first eigenmodes in axisymmetric shells
  as the thickness tends to zero

abstract:
  The lowest eigenmode of thin axisymmetric shells is investigated for two
physical models (acoustics and elasticity) as the shell thickness (2$\epsilon$)
tends to zero. Using a novel asymptotic expansion we determine the behavior of
the eigenvalue $\lambda$($\epsilon$) and the eigenvector angular frequency
k($\epsilon$) for shells with Dirichlet boundary conditions along the lateral
boundary, and natural boundary conditions on the other parts. First, the scalar
Laplace operator for acoustics is addressed, for which k($\epsilon$) is always
zero. In contrast to it, for the Lam{\'e} system of linear elasticity several
different types of shells are defined, characterized by their geometry, for
which k($\epsilon$) tends to infinity as $\epsilon$ tends to zero. For two
families of shells: cylinders and elliptical barrels we explicitly provide
$\lambda$($\epsilon$) and k($\epsilon$) and demonstrate by numerical examples
the different behavior as $\epsilon$ tends to zero.


title: Imaginary noise and parity conservation in the reaction A+A <--> 0

abstract:
  The master equation for the reversible reaction A+A <--> 0 is considered in
Poisson representation, where it is equivalent to a Langevin equation with
imaginary noise for a complex stochastic variable \phi. Such Langevin equations
appear quite generally in field-theoretic treatments of reaction-diffusion
problems. For this example we study the probability flow in the complex \phi
plane both analytically and by simulation. We show that this flow has various
curious features that must be expected to occur similarly in other Langevin
equations associated with reaction-diffusion problems.


title: A Note on Coherent States with Quantum Gravity Effects

abstract:
  Existence of a minimal measurable length and an upper bound for the momentum
fluctuations are the casting reasons for generalization of uncertainty
principle and then reformulation of Hilbert space representation of quantum
mechanics. In this paper, we study the consequences of the Generalized
Uncertainty Principle (GUP) in the presence of both minimal length and maximal
momentum. We consider a simple harmonic oscillator in the framework of GUP by
introducing it's energy eigenstates and energy spectrum. Investigation of
coherent states for a generalized harmonic oscillator and it's generic behavior
are the other topics in our study.


title: A new asymptotic expansion series for the constant pi

abstract:
  In our recent publications we have introduced the incomplete cosine expansion
of the sinc function for efficient application in sampling [Abrarov & Quine,
Appl. Math. Comput., 258 (2015) 425-435; Abrarov & Quine, J. Math. Research, 7
(2) (2015) 163-174]. Here we show that it can also be utilized as a flexible
and efficient tool in mathematical analysis. In particular, an application of
the incomplete cosine expansion of the sinc function leads to expansion series
of the error function in form of a sum of the Gaussian functions. This approach
in integration provides a new asymptotic formula for the constant $\pi$.


title: Interferometry concepts

abstract:
  This paper serves as an introduction to the current book. It provides the
basic notions of long-baseline optical/infrared interferome-try prior to
reading all the subsequent chapters, and is not an extended introduction to the
field.


title:
General relativistic massive vector field effects in Gamma Ray Burst
  production

abstract:
  To explain the extremely high energy release, $>10^{53}$~erg, suggested by
the observations of some Gamma Ray Bursts (GRBs) we propose a new energy
extraction mechanism from the rotation energy of a Kerr-Newman black hole (BH)
by a massive photon field. Numerical results show that this mechanism is stable
with respect to the black hole rotation parameter, $a$, with a clear dependence
on the BH mass, $M$, and charge, $Q$, and can extract energies up to $10^{54}$
erg. The controversial "energy crisis" problem of GRBs that does not show
evidence for collimated emission may benefit of this energy extraction
mechanism. With these results we set a lower bound on the coupling between
electromagnetic and gravitational fields.


title:
A note on the relations between thermodynamics, energy definitions and
  Friedmann equations

abstract:
  In what follows, we investigate the relation between the Friedmann and
thermodynamic pressure equations, through solving the Friedmann and
thermodynamic pressure equations simultaneously. Our investigation shows that a
perfect fluid, as a suitable solution for the Friedmann equations leading to
the standard modelling of the universe expansion history, cannot simultaneously
satisfy the thermodynamic pressure equation and those of Friedmann. Moreover,
we consider various energy definitions, such as the Komar mass, and solve the
Friedmann and thermodynamic pressure equations simultaneously to get some
models for dark energy. The cosmological consequences of obtained solutions are
also addressed. Our results indicate that some of obtained solutions may unify
the dominated fluid in both the primary inflationary and current accelerating
eras into one model. In addition, by taking into account a cosmic fluid of a
known equation of state, and combining it with the Friedmann and thermodynamic
pressure equations, we obtain the corresponding energy of these cosmic fluids
and face their limitations. Finally, we point out the cosmological features of
this cosmic fluid and also study its observational constraints.


title: Accretion Onto a Charged Higher-Dimensional Black Hole

abstract:
  This paper deals with the steady-state polytropic fluid accretion onto a
higher-dimensional Reissner-Nordstr$\ddot{o}$m black hole. We formulate the
generalized mass flux conservation equation, energy flux conservation and
relativistic Bernoulli equation to discuss the accretion process. The critical
accretion is investigated by finding critical radius, critical sound velocity
and critical flow velocity. We also explore gas compression and temperature
profiles to analyze the asymptotic behavior. It is found that the results for
Schwarzschild black hole are recovered when $q=0$ in four dimensions. We
conclude that accretion process in higher dimensions becomes slower in the
presence of charge.


title:
Badly approximable vectors and fractals defined by conformal dynamical
  systems

abstract:
  We prove that if $J$ is the limit set of an irreducible conformal iterated
function system (with either finite or countably infinite alphabet), then the
badly approximable vectors form a set of full Hausdorff dimension in $J$. The
same is true if $J$ is the radial Julia set of an irreducible meromorphic
function (either rational or transcendental). The method of proof is to find
subsets of $J$ that support absolutely friendly and Ahlfors regular measures of
large dimension. In the appendix to this paper, we answer a question of
Broderick, Kleinbock, Reich, Weiss, and the second-named author ('12) by
showing that every hyperplane diffuse set supports an absolutely decaying
measure.


title:
Edge Coloring and Stopping Sets Analysis in Product Codes with MDS
  components

abstract:
  We consider non-binary product codes with MDS components and their iterative
row-column algebraic decoding on the erasure channel. Both independent and
block erasures are considered in this paper. A compact graph representation is
introduced on which we define double-diversity edge colorings via the rootcheck
concept. An upper bound of the number of decoding iterations is given as a
function of the graph size and the color palette size $M$. Stopping sets are
defined in the context of MDS components and a relationship is established with
the graph representation. A full characterization of these stopping sets is
given up to a size $(d_1+1)(d_2+1)$, where $d_1$ and $d_2$ are the minimum
Hamming distances of the column and row MDS components respectively. Then, we
propose a differential evolution edge coloring algorithm that produces
colorings with a large population of minimal rootcheck order symbols. The
complexity of this algorithm per iteration is $o(M^{\aleph})$, for a given
differential evolution parameter $\aleph$, where $M^{\aleph}$ itself is small
with respect to the huge cardinality of the coloring ensemble. The performance
of MDS-based product codes with and without double-diversity coloring is
analyzed in presence of both block and independent erasures. In the latter
case, ML and iterative decoding are proven to coincide at small channel erasure
probability. Furthermore, numerical results show excellent performance in
presence of unequal erasure probability due to double-diversity colorings.


title: On the Numerical Solution of the Far Field Refractor Problem

abstract:
  The far field refractor problem with a discrete target is solved with a
numerical scheme that uses and simplify ideas from Caffarelli, Kochengin and
Oliker. A numerical implementation is carried out and examples are shown.


title: Electronic and ionic conductivities in superionic Li$_4$C$_{60}$

abstract:
  The $10$ GHz microwave conductivity, $\sigma(T)$ and high field, $222$ GHz
electron spin resonance (HF-ESR) of Li$_4$C$_{60}$ fulleride is measured in a
wide temperature range. We suggest that the majority of ESR active sites and at
least some of the charge carriers for $\sigma(T)$ are electrons bound to a
small concentration of surplus or vacancy ions in the polymer phase. Both
$\sigma(T)$ and the ESR line shape depend on ionic motion. A change of the
activation energy of $\sigma(T)$ at $125$ K coincides with the onset of the
ionic DC conductivity. The ESR line shape is determined mainly by Li ionic
motion within octahedral voids below $150$ K. At higher temperatures,
fluctuations due to ionic diffusion change the environment of defects from
axial to effectively isotropic on the ESR time scale. $\sigma(T)$ data up to
$700$ K through the depolymerization transition confirm that the monomeric
phase of Li$_4$C$_{60}$ is a metal.


title: Charmed partner of the exotic $X(5568)$ state and its properties

abstract:
  The mass, decay constant and width of a hypothetical charmed partner $X_c$ of
the newly observed exotic $X_b(5568)$ state are calculated using a technique of
QCD sum rule method. The $X_c=[su][\overline{c}\overline{d}]$ state with
$J^{P}=0^{+}$ is described employing two types of the diquark-antidiquark
interpolating currents. The evaluation of the mass $m_{X_c}$ and decay constant
$f_{X_c}$ is carried out utilizing the two-point sum rule method by including
vacuum condensates up to eight dimensions. The widths of the decay channels
$X_c \to D_s^{-} \pi^{+}$ and $X_c \to D^{0} K^{0}$ are also found. To this
end, the strong couplings $g_{X_{c}D_{s}\pi}$ and $g_{X_{c}D K}$ are computed
by means of QCD sum rules on the light-cone and soft-meson approximation.


title:
Minimax Design and Order Estimation of FIR Filters for Extending the
  Bandwidth of ADCs

abstract:
  The bandwidth of the sampling systems, especially for time-interleaved
analog-to-digital converters, needs to be extended along with the rapid
increase of the sampling rate. A digitally assisted technique becomes a
feasible approach to extend the analog bandwidth, as it is impractical to
implement the extension in analog circuits. This paper derives accurate order
estimation formulas for the bandwidth extension filter, which is designed in
the minimax sense with the ripple constraints as the design criteria. The
derived filter order estimation is significant in evaluating the computational
complexity from the viewpoint of the top-level system design. Moreover, with
the proposed order estimates, one can conveniently obtain the minimal order
that satisfies the given ripple constraints, which contributes to reducing the
design time. Both the performance of the extension filter and its order
estimation are illustrated and demonstrated through simulation examples.


title:
Exact and optimal controllability for scalar conservation laws with
  discontinuous flux

abstract:
  This paper deals with an optimal control problem and describes the reachable
set for the scalar 1-D conservation laws with discontinuous flux. Regarding the
optimal control problem we first prove the existence of a minimizer and then we
prescribe an algorithm to compute it. The same method also applies to compute
the initial data control. The proof relies on the explicit formula for the
conservation laws with the discontinuous flux and finer properties of the
characteristics.


title: The Accretion Disk Wind in the Black Hole GRS 1915+105

abstract:
  We report on a 120 ks Chandra/HETG spectrum of the black hole GRS 1915+105.
The observation was made during an extended and bright soft state in June,
2015. An extremely rich disk wind absorption spectrum is detected, similar to
that observed at lower sensitivity in 2007. The very high resolution of the
third-order spectrum reveals four components to the disk wind in the Fe K band
alone; the fastest has a blue-shift of v = 0.03c. Broadened re-emission from
the wind is also detected in the first-order spectrum, giving rise to clear
accretion disk P Cygni profiles. Dynamical modeling of the re-emission spectrum
gives wind launching radii of r ~ 10^(2-4) GM/c^2. Wind density values of n ~
10^(13-16) cm^-3 are then required by the ionization parameter formalism. The
small launching radii, high density values, and inferred high mass outflow
rates signal a role for magnetic driving. With simple, reasonable assumptions,
the wind properties constrain the magnitude of the emergent magnetic field to B
~ 10^(3-4) Gauss if the wind is driven via magnetohydrodynamic (MHD) pressure
from within the disk, and B ~ 10^(4-5) Gauss if the wind is driven by
magnetocentrifugal acceleration. The MHD estimates are below upper limits
predicted by the canonical alpha-disk model (Shakura & Sunyaev 1973). We
discuss these results in terms of fundamental disk physics and black hole
accretion modes.


title:
The cohomology ring of certain families of periodic virtually cyclic
  groups

abstract:
  Let G be a virtually cyclic of the form (Z_a x Z_b) x Z or [Z_a x (Z b x
Q_{2^i})] x Z. We compute the integral cohomology ring of G, and then obtain
the periodicity of the Farell cohomology of these groups.


title:
Vine copula based likelihood estimation of dependence patterns in
  multivariate event time data

abstract:
  In many studies multivariate event time data are generated from clusters
having a possibly complex association pattern. Flexible models are needed to
capture this dependence. Vine copulas serve this purpose. Inference methods for
vine copulas are available for complete data. Event time data, however, are
often subject to right-censoring. As a consequence, the existing inferential
tools, e.g. likelihood estimation, need to be adapted. A two-stage estimation
approach is proposed. First, the marginal distributions are modeled. Second,
the dependence structure modeled by a vine copula is estimated via likelihood
maximization. Due to the right-censoring single and double integrals show up in
the copula likelihood expression such that numerical integration is needed for
its evaluation. For the dependence modeling a sequential estimation approach
that facilitates the computational challenges of the likelihood optimization is
provided. A three-dimensional simulation study provides evidence for the good
finite sample performance of the proposed method. Using four-dimensional
mastitis data, it is shown how an appropriate vine copula model can be selected
for data at hand.


title:
Direct observation of Rogue Waves in optical turbulence using Time
  Microscopy

abstract:
  The formation of coherent structures in noise driven phenomena and in
Turbulence is a complex and fundamental question. A particulary important
structure is the so-called Rogue Wave (RW) that arises as the sudden appearance
of a localized and giant peak. First studied in Oceanography, RWs have been
extensively investigated in Optics since 2007, in particular in optical fibers
experiments on supercontinua and optical turbulence. However the typical time
scales underlying the random dynamics in those experiments prevented --up to
now-- the direct observation of isolated RWs. Here we report on the direct
observation of RWs, using an ultrafast acquisition system equivalent to
microscope in the time domain. The RWs are generated by nonlinear propagation
of random waves inside an optical fiber, and recorded with $\sim 250$~fs
resolution. Our experiments demonstrate the central role played by
"breathers-like" solutions of the one-dimensional nonlinear Schr\"odinger
equation (1D-NLSE) in the formation of RWs


title: Quantum expectations via spectrograms

abstract:
  We discuss a new phase space method for the computation of quantum
expectation values in the high frequency regime. Instead of representing a
wavefunction by its Wigner function, which typically attains negative values,
we define a new phase space density by adding a first-order Hermite spectrogram
term as a correction to the Husimi function. The new phase space density yields
accurate approximations of the quantum expectation values as well as allows
numerical sampling from non-negative densities. We illustrate the new method by
numerical experiments in up to $128$ dimensions.


title: Pressure in Lema\^{i}tre-Tolman-Bondi solutions and cosmologies

abstract:
  Lema\^{i}tre-Tolman-Bondi (LTB) solutions have traditionally been confined to
systems with no pressure in which the gravity is due to massive dust, but the
solutions are little changed in form if, as in cosmology, the pressure is
uniform in space at each comoving time. This allows the equations of cosmology
to be deduced in a manner that more closely resembles classical mechanics. It
also gives some inhomogeneous solutions with growing condensations and black
holes. We give criteria by which the sizes of different closed models of the
universe can be compared and discuss conditions for self-closure of
inhomogeneous cosmologies with a $\Lambda$-term.


title:
Improved Algorithms and Coupled Neutron-Photon Transport for
  Auto-Importance Sampling Method

abstract:
  The Auto-Importance Sampling (AIS) method is a Monte Carlo variance reduction
technique proposed for deep penetration problems, which can significantly
improve computational efficiency without pre-calculations for importance
distribution. However, the AIS method is only validated with several simple
examples, and cannot be used for coupled neutron-photon transport. This paper
presents the improved algorithms for the AIS method, including particle
transport, fictitious particles creation and adjustment, fictitious surface
geometry, random number allocation and calculation of the estimated relative
error. These improvements allow the AIS method to be applicable to complicated
deep penetration problems with complex geometry and multiple materials. A
coupled Neutron-Photon Auto-Importance Sampling (NP-AIS) method is proposed to
solve the deep penetration problems of coupled neutron-photon transport using
the improved algorithms. The NUREG/CR-6115 PWR benchmark was calculated by
using the methods of NP-AIS, geometry splitting with Russian roulette and the
analog Monte Carlo, respectively. The calculation results of NP-AIS were in
good agreement with those of geometry splitting with Russian roulette and the
benchmark solutions. The computational efficiency of NP-AIS for both neutron
and photon was much better than that of geometry splitting with Russian
roulette in most cases, and increased by several orders of magnitude compared
with that of the analog Monte Carlo.


title: Gibbs Random Fields and Markov Random Fields with Constraints

abstract:
  It was shown many times in the literature that a Markov random field is
equivalent to a Gibbs random field when all realizations of the field have
non-zero probabilities; the proofs are rather complicated. A simpler proof,
which is based directly on simple probability theory, is presented.
Furthermore, it is shown that the equivalence is still valid when there are
constraints (zero probability realizations) of any type. The equivalence
extends to infinite size random fields, as well.


title: 373 K Superconductors

abstract:
  Experimental evidence of superconductors with critical temperatures above
$373\:K$ is presented. In a family of different compounds we demonstrate the
superconductor state, the transition to normal state above $387\:K$, an
intermediate $242\:K$ superconductor, susceptibility up to $350\:K$, $I-V$
curves at $4.2\:K$ in magnetic field of $12\:T$ and current up to $60\:A$,
$300\:K$ Josephson Junctions and Shapiro steps with radiation of $5\:GHz$ to
$21\:THz$, $300\:K$ tapes tests with high currents up to $3000\:A$ and many
$THz$ images of coins and washers. Due to a pending patent, the exact chemical
characterization and technological processes for these materials are
temporarily withheld and will be presented elsewhere.


title: Minimal Length, Measurability and Gravity

abstract:
  The present work is a continuation of the previous papers written by the
author on the subject. In terms of the measurability (or measurable quantities)
notion introduced in a minimal length theory, first the consideration is given
to a quantum theory in the momentum representation. The same terms are used to
consider the Markov gravity model that here illustrates the general approach to
studies of gravity in terms of measurable quantities. This paper is dedicated
to the 75th Anniversary of Professor Vladimir Grigor'evich Baryshevsky.


title: Geometric mean, splines and de Boor algorithm in geodesic spaces

abstract:
  We extend the concepts of de Casteljau and de Boor algorithms as well as
splines to geodesic spaces and present some applications in geometric modeling.
The concept of weighted geometric mean provides another approach to splines. We
compare the corresponding Bezier curves and show that for Riemannian manifolds,
their endpoint tangents coincide.


title:
Lieb-Thirring and Cwickel-Lieb-Rozenblum inequalities for perturbed
  graphene with a Coulomb impurity

abstract:
  We study the two dimensional massless Coulomb-Dirac operator restricted to
its positive spectral subspace and prove estimates on the negative eigenvalues
created by electromagnetic perturbations.


title: Distributed $(\Delta+1)$-Coloring in Sublogarithmic Rounds

abstract:
  We give a new randomized distributed algorithm for $(\Delta+1)$-coloring in
the LOCAL model, running in $O(\sqrt{\log \Delta})+ 2^{O(\sqrt{\log \log n})}$
rounds in a graph of maximum degree~$\Delta$. This implies that the
$(\Delta+1)$-coloring problem is easier than the maximal independent set
problem and the maximal matching problem, due to their lower bounds of $\Omega
\left( \min \left( \sqrt{\frac{\log n}{\log \log n}}, \frac{\log \Delta}{\log
\log \Delta} \right) \right)$ by Kuhn, Moscibroda, and Wattenhofer [PODC'04].
Our algorithm also extends to list-coloring where the palette of each node
contains $\Delta+1$ colors. We extend the set of distributed symmetry-breaking
techniques by performing a decomposition of graphs into dense and sparse parts.


title:
Inclination angle and braking index evolution of pulsars with
  plasma-filled magnetosphere: application to high braking index of PSR
  J1640-4631

abstract:
  The recently discovered rotationally powered pulsar PSR J1640-4631 is the
first to have a braking index measured, with high enough precision, that is
greater than three. An inclined magnetic rotator in vacuum or plasma would be
subject not only to spin-down but also to an alignment torque. The vacuum model
can address the braking index only for an almost orthogonal rotator that is
incompatible with the single peaked pulse profile. The magnetic dipole model
with the corotating plasma predicts braking indices between $3-3.25$. We find
that the braking index of $3.15$ is consistent with two different inclination
angles, $18.5\pm 3$ degrees and $56 \pm 4$ degrees. The smaller angle is
preferred given the pulse profile has a single peak and the radio output of the
source is weak. We infer the change in the inclination angle to be at the rate
$-0.23$ degrees per century, three times smaller in absolute value than the
rate recently observed for the Crab pulsar.


title:
A knowledge representation meta-model for rule-based modelling of
  signalling networks

abstract:
  The study of cellular signalling pathways and their deregulation in disease
states, such as cancer, is a large and extremely complex task. Indeed, these
systems involve many parts and processes but are studied piecewise and their
literatures and data are consequently fragmented, distributed and sometimes--at
least apparently--inconsistent. This makes it extremely difficult to build
significant explanatory models with the result that effects in these systems
that are brought about by many interacting factors are poorly understood.
  The rule-based approach to modelling has shown some promise for the
representation of the highly combinatorial systems typically found in
signalling where many of the proteins are composed of multiple binding domains,
capable of simultaneous interactions, and/or peptide motifs controlled by
post-translational modifications. However, the rule-based approach requires
highly detailed information about the precise conditions for each and every
interaction which is rarely available from any one single source. Rather, these
conditions must be painstakingly inferred and curated, by hand, from
information contained in many papers--each of which contains only part of the
story.
  In this paper, we introduce a graph-based meta-model, attuned to the
representation of cellular signalling networks, which aims to ease this massive
cognitive burden on the rule-based curation process. This meta-model is a
generalization of that used by Kappa and BNGL which allows for the flexible
representation of knowledge at various levels of granularity. In particular, it
allows us to deal with information which has either too little, or too much,
detail with respect to the strict rule-based meta-model. Our approach provides
a basis for the gradual aggregation of fragmented biological knowledge
extracted from the literature into an instance of the meta-model from which we
can define an automated translation into executable Kappa programs.


title: Performance Localisation

abstract:
  Performance becomes an issue particularly when execution cost hinders the
functionality of a program. Typically a profiler can be used to find program
code execution which represents a large portion of the overall execution cost
of a program. Pinpointing where a performance issue exists provides a starting
point for tracing cause back through a program.
  While profiling shows where a performance issue manifests, we use mutation
analysis to show where a performance improvement is likely to exist. We find
that mutation analysis can indicate locations within a program which are highly
impactful to the overall execution cost of a program yet are executed
relatively infrequently. By better locating potential performance improvements
in programs we hope to make performance improvement more amenable to
automation.


title: Particle Acceleration in Relativistic Electron-Ion Outlfows

abstract:
  We use the Los Alamos VPIC code to investigate particle acceleration in
relativistic, unmagnetized, collisionless electron-ion plasmas. We run our
simulations both with a realistic proton-to-electron mass ratio m_p/m_e = 1836,
as well as commonly employed mass ratios of m_p/m_e =100 and 25, and show that
results differ among the different cases. In particular, for the physically
accurate mass ratio, electron acceleration occurs efficiently in a narrow
region of a few hundred inertial lengths near the flow front, producing a power
law dN/dgamma ~ gamma^(-p) with p ~ -2 developing over a few decades in energy,
while acceleration is weak in the region far downstream. We find 20%, 10%, and
0.2% of the total energy given to the electrons for mass ratios of 25, 100, and
1836 respectively at a time of 2500 (w_p)^-1. Our simulations also show
significant magnetic field generation just ahead of and behind the the flow
front, with about 1% of the total energy going into the magnetic field for a
mass ratio of 25 and 100, and 0.1% for a mass ratio of and 1836. In addition,
lower mass ratios show significant fields much further downstream than in the
realistic mass ratio case. Our results suggest the region and energetic extent
of particle acceleration is directly related to the presence of magnetic field
generation. Our work sheds light on the understanding of particle acceleration
and emission in gamma-ray bursts, among other relativistic astrophysical
outflows, but also underscores the necessity of optimizing numerical and
physical parameters, as well as comparing among PIC codes before firm
conclusions are drawn from these types of simulations.


title: Embeddings and $C^*$-envelopes of exact operator systems

abstract:
  We prove a necessary and sufficient condition for embeddability of an
operator system into $\mathcal{O}_2$. Using Kirchberg's theorems on a tensor
product of $\mathcal{O}_2$ and $\mathcal{O}_{\infty}$, we establish results on
their operator system counterparts $\mathcal{S}_2$ and $\mathcal{S}_{\infty}$.
Applications of the results proved, including some examples describing
$C^*$-envelopes of operator systems, are also discussed.


title: Charge induced nematicity in FeSe

abstract:
  The spontaneous appearance of nematicity, a state of matter that breaks
rotation but not translation symmetry, is one of the most intriguing property
of the iron based superconductors (Fe SC), and has relevance for the cuprates
as well. Establishing the critical electronic modes behind nematicity remains
however a challenge, because their associated susceptibilities are not easily
accessible by conventional probes. Here using FeSe as a model system, and
symmetry resolved electronic Raman scattering as a probe, we unravel the
presence of critical charge nematic fluctuations near the structural / nematic
transition temperature, T$_S\sim$ 90 K. The diverging behavior of the
associated nematic susceptibility foretells the presence of a Pomeranchuk
instability of the Fermi surface with d-wave symmetry. The excellent scaling
between the observed nematic susceptibility and elastic modulus data
demonstrates that the structural distortion is driven by this d-wave
Pomeranchuk transition. Our results make a strong case for charge induced
nematicity in FeSe.


title: QDQ vs. UCT

abstract:
  This is a survey of recent progress in the structure and classification
theory of nuclear C*-algebras. In particular, I outline how the Universal
Coefficient Theorem ensures a positive answer to the quasidiagonality question
in the presence of faithful traces. This has strong consequences for the
regularity conjecture and the classification problem for separable, simple,
nuclear C*-algebras. Moreover, it entails a positive solution to Rosenberg's
conjecture on quasidiagonality of reduced C*-algebras of discrete amenable
groups. This note is largely based on a joint paper with Aaron Tikuisis and
Stuart White.


title:
Spectral asymptotics on sequences of elliptically degenerating Riemann
  surfaces

abstract:
  This is the second in a series of two articles where we study various aspects
of the spectral theory associated to families of hyperbolic Riemann surfaces
obtained through elliptic degeneration. In the first article, we investigate
the asymptotics of the trace of the heat kernel both near zero and infinity and
we show the convergence of small eigenvalues and corresponding eigenfunctions.
Having obtained necessary bounds for the trace, this second article presents
the behavior of several spectral invariants. Some of these invariants, such as
the Selberg zeta function and the spectral counting functions associated to
small eigenvalues below 1/4, converge to their respective counterparts on the
limiting surface. Other spectral invariants, such as the spectral zeta function
and the logarithm of the determinant of the Laplacian diverge. In these latter
cases, we identify diverging terms and remove their contributions, thus
regularizing convergence of these spectral invariants. Our study is motivated
by a result from \cite{He 83}, which D. Hejhal attributes to A. Selberg,
proving spectral accumulation for the family of Hecke triangle groups. In this
article, we obtain a quantitative result to Selberg's remark.