title:
Linear nonequilibrium thermodynamics of reversible periodic processes
  and chemical oscillations

abstract:
  Onsager's phenomenological equations successfully describe irreversible
thermodynamic processes. They assume a symmetric coupling matrix between
thermodynamic fluxes and forces. It is easily shown that the antisymmetric part
of a coupling matrix does not contribute to dissipation. Therefore, entropy
production is exclusively governed by the symmetric matrix even in the presence
of antisymmetric terms. In this work we focus on the antisymmetric
contributions which describe isentropic oscillations and well-defined equations
of motion. The formalism contains variables that are equivalent to momenta, and
coefficients that are analogous to an inertial mass. We apply this formalism to
simple problems such as an oscillating piston and the oscillation in an
electrical LC-circuit. We show that isentropic oscillations are possible even
close to equilibrium in the linear limit and one does not require far-from
equilibrium situations. One can extend this formalism to other pairs of
variables, including chemical systems with oscillations. In isentropic
thermodynamic systems all extensive and intensive variables including
temperature can display oscillations reminiscent of adiabatic waves.


title: The star-shapedness of a generalized numerical range

abstract:
  Let $\mathcal{H}_n$ be the set of all $n\times n$ Hermitian matrices and
$\mathcal{H}^m_n$ be the set of all $m$-tuples of $n\times n$ Hermitian
matrices. For $A=(A_1,...,A_m)\in \mathcal{H}^m_n$ and for any linear map
$L:\mathcal{H}^m_n\to\mathbb{R}^\ell$, we define the $L$-numerical range of $A$
by \[ W_L(A):=\{L(U^*A_1U,...,U^*A_mU): U\in \mathbb{C}^{n\times n},
U^*U=I_n\}. \] In this paper, we prove that if $\ell\leq 3$, $n\geq \ell$ and
$A_1,...,A_m$ are simultaneously unitarily diagonalizable, then $W_L(A)$ is
star-shaped with star center at $L\left(\frac{\mathrm{tr}
A_1}{n}I_n,...,\frac{\mathrm{tr} A_m}{n}I_n\right)$.


title:
Exponential laws for spaces of differentiable functions on topological
  groups

abstract:
  Smooth functions $f:G\to E$ from a topological group $G$ to a locally convex
space $E$ were considered by Riss (1953), Boseck, Czichowski and Rudolph
(1981), Belti\c{t}\u{a} and Nicolae (2015), and others, in varying degrees of
generality. The space $C^\infty(G,E)$ of such functions carries a natural
topology, the compact-open $C^\infty$-topology. For topological groups $G$ and
$H$, we show that $C^\infty(G\times H,E)\cong C^\infty(G,C^\infty(H,E))$ as a
locally convex space, whenever both $G$ and $H$ are metrizable or both $G$ and
$H$ are locally compact. Likewise, $C^k(G, C^l(H,E))$ can be identified with a
suitable space of functions on $G\times H$.


title:
The field of invariants for the adjoint action of the Borel group in the
  nilradical of a parabolic subalgebra

abstract:
  In this paper the field of invariants for the adjoint action of the Borel
group in the nilradical of a parabolic subalgebra is studied. We construct the
set of B-invariant rational functions generating the field of invariants.


title:
Core-collapse supernova progenitor constraints using the spatial
  distributions of massive stars in local galaxies

abstract:
  We study the spatial correlations between the H$\alpha$ emission and
different types of massive stars in two local galaxies, the Large Magellanic
Cloud (LMC) and Messier 33. We compare these to correlations derived for
core-collapse supernovae (CCSNe) in the literature to connect CCSNe of
different types with the initial masses of their progenitors and to test the
validity of progenitor mass estimates which use the pixel statistics method. We
obtain samples of evolved massive stars in both galaxies from catalogues with
good spatial coverage and/or completeness, and combine them with coordinates of
main-sequence stars in the LMC from the SIMBAD database. We calculate the
spatial correlation of stars of different classes and spectral types with
H$\alpha$ emission. We also investigate the effects of distance, noise and
positional errors on the pixel statistics method. A higher correlation with
H$\alpha$ emission is found to correspond to a shorter stellar lifespan, and we
conclude that the method can be used as an indicator of the ages, and therefore
initial masses, of SN progenitors. We find that the spatial distributions of
type II-P SNe and red supergiants of appropriate initial mass ($\gtrsim$9
$M_{\odot}$) are consistent with each other. We also find the distributions of
type Ic SNe and WN stars with initial masses $\gtrsim$20 $M_{\odot}$
consistent, while supergiants with initial masses around 15 $M_{\odot}$ are a
better match for type IIb and II-L SNe. The type Ib distribution corresponds to
the same stellar types as type II-P, which suggests an origin in interacting
binaries. On the other hand, we find that luminous blue variable stars show a
much stronger correlation with H$\alpha$ emission than do type IIn SNe.


title: On Preambles With Low Out of Band Radiation for Channel Estimation

abstract:
  In this paper, we investigate preamble designs for channel estimation, that
jointly address the estimation efficiency in terms of MSE of the channel
estimates, and the OOB radiation of the transmit preambles. We provide two
novel design techniques, based on a convex optimization problem, to obtain
optimal preambles for a single carrier and provide a juxtaposition based method
to extend their application to multi-carrier systems. The obtained preambles
are shown to have 10 dB to 35 dB lower OOB radiation than the existing preamble
based estimation techniques. We also show the fundamental trade-off between the
estimation efficiency and the OOB radiation and highlight that the improved OOB
performance comes at a cost of increased estimation error. Finally, as a case
study, the estimated channel values are used in equalization of a MIMO GFDM
system that is aimed for transmit diversity.


title:
Dust evolution processes constrained by extinction curves in nearby
  galaxies

abstract:
  Extinction curves, especially those in the Milky Way (MW), the Large
Magellanic Cloud (LMC), and the Small Magellanic Cloud (SMC), have provided us
with a clue to the dust properties in the nearby Universe. We examine whether
or not these extinction curves can be explained by well known dust evolution
processes. We treat the dust production in stellar ejecta, destruction in
supernova shocks, dust growth by accretion and coagulation, and dust disruption
by shattering. To make a survey of the large parameter space possible, we
simplify the treatment of the grain size distribution evolution by adopting the
`two-size approximation', in which we divide the grain population into small
($\lesssim 0.03~\mu$m) and large ($\gtrsim 0.03~\mu$m) grains. It is confirmed
that the MW extinction curve can be reproduced in reasonable ranges for the
time-scale of the above processes with a silicate-graphite mixture. This
indicates that the MW extinction curve is a natural consequence of the dust
evolution through the above processes. We also find that the same models fail
to reproduce the SMC/LMC extinction curves. Nevertheless, this failure can be
remedied by giving higher supernova destruction rates for small carbonaceous
dust and considering amorphous carbon for carbonaceous dust; these modification
fall in fact in line with previous studies. Therefore, we conclude that the
current dust evolution scenario composed of the aforementioned processes is
successful in explaining the extinction curves. All the extinction curves favor
efficient interstellar processing of dust, especially, strong grain growth by
accretion and coagulation.


title:
Spin dynamics of the ordered dipolar-octupolar pseudospin-$^1/_2$
  pyrochlore Nd$_2$Zr$_2$O$_7$ probed by muon spin relaxation

abstract:
  We present a muon spin relaxation study on the Ising pyrochlore
Nd$_2$Zr$_2$O$_7$ which develops an "all-in-all-out" magnetic order below
0.4~K. At 20~mK far below the ordering transition temperature, the zero-field
muon spin relaxation spectra show no static features and can be well described
by a dynamical Gaussian-broadened Gaussian Kubo-Toyabe function indicating
strong fluctuations of the ordered state. The spectra of the paramagnetic state
(below 4.2~K) reveal anomalously slow paramagnetic spin dynamics and show only
small difference with the spectra of the ordered state. We find that the
fluctuation rate decreases with decreasing temperature and becomes nearly
temperature independent below the transition temperature indicating persistent
slow spin dynamics in the ground state. The field distribution width shows a
small but sudden increase at the transition temperature and then becomes almost
constant. The spectra in applied longitudinal fields are well fitted by the
conventional dynamical Gaussian Kubo-Toyabe function, which further supports
the dynamical nature of the ground state. The fluctuation rate shows a peak as
a function of external field which is associated with a field-induced spin-flip
transition. The strong dynamics in the ordered state are attributed to the
transverse coupling of the Ising spins introduced by the multipole
interactions.


title:
Convexity and Star-shapedness of Real Linear Images of Special
  Orthogonal Orbits

abstract:
  Let $A\in \mathbb{R}^{N\times N}$ and $\mathrm{SO}_n:=\{ U \in \mathbb{R}^{N
\times N}:UU^t=I_n,\det U>0\}$ be the set of $n\times n$ special orthogonal
matrices. Define the (real) special orthogonal orbit of $A$ by \[
O(A):=\{UAV:U,V\in\mathrm{SO}_n\}. \] In this paper, we show that the linear
image of $O(A)$ is star-shaped with respect to the origin for arbitrary linear
maps $L:\mathbb{R}^{N\times N}\to\mathbb{R}^\ell$ if $n\geq 2^{\ell-1}$. In
particular, for linear maps $L:\mathbb{R}^{N\times N}\to\mathbb{R}^2$ and when
$A$ has distinct singular values, we study $B\in O(A)$ such that $L(B)$ is a
boundary point of $L(O(A))$. This gives an alternative proof of a result by Li
and Tam on the convexity of $L(O(A))$ for linear maps $L:\mathbb{R}^{N\times
N}\to\mathbb{R}^2$.


title:
The virial theorem and ground state energy estimate of nonlinear
  Schr\"odinger equations in $\mathbb{R}^2$ with square root and saturable
  nonlinearities in nonlinear optics

abstract:
  The virial theorem is a nice property for the linear Schrodinger equation in
atomic and molecular physics as it gives an elegant ratio between the kinetic
and potential energies and is useful in assessing the quality of numerically
computed eigenvalues. If the governing equation is a nonlinear Schrodinger
equation with power-law nonlinearity, then a similar ratio can be obtained but
there seems no way of getting any eigenvalue estimate. It is surprising as far
as we are concerned that when the nonlinearity is either square-root or
saturable nonlinearity (not a power-law), one can develop a virial theorem and
eigenvalue estimate of nonlinear Schrodinger (NLS) equations in R2 with
square-root and saturable nonlinearity, respectively. Furthermore, we show here
that the eigenvalue estimate can be used to obtain the 2nd order term (which is
of order $ln\Gamma$) of the lower bound of the ground state energy as the
coefficient $\Gamma$ of the nonlinear term tends to infinity.

categories: math.AP math-ph math.MP nlin.PS physics.optics


title:
Estimating Maximum Error Impact in Dynamic Data-driven Applications for
  Resource-aware Adaption of Software-based Fault-Tolerance

abstract:
  The rise of transient faults in modern hardware requires system designers to
consider errors occurring at runtime. Both hardware- and software-based error
handling must be deployed to meet application reliability requirements. The
level of required reliability can vary for system components and depend on
input and state, so that a selective use of resilience methods is advised,
especially for resource-constrained platforms as found in embedded systems. If
an error occurring at runtime can be classified as having negligible or
tolerable impact, less effort can be spent on correcting it. As the actual
impact of an error is often dependent on the state of a system at time of
occurrence, it can not be determined precisely for highly dynamic workloads in
data-driven applications. We present a concept to estimate error propagation in
sets of tasks with variable data dependencies. This allows for a coarse grained
analysis of the impact a failed task may have on the overall output. As an
application example, we demonstrate our method for a typical dynamic embedded
application, namely a decoder for the H.264 video format.


title: Meson-baryon effective chiral Lagrangians at order $p^4$

abstract:
  We construct the three-flavor Lorentz-invariant meson-baryon chiral
Lagrangians at the order $p^4$, with which a full one-loop investigation may be
performed. One obtains 540 independent terms. The processes with the minimal
number of mesons and photons that this order Lagrangians may contribute to are
also presented.


title:
Aspects of geodesical motion with Fisher-Rao metric: classical and
  quantum

abstract:
  The purpose of this article is to exploit the geometric structure of Quantum
Mechanics and of statistical manifolds to study the qualitative effect that the
quantum properties have in the statistical description of a system. We show
that the end points of geodesics in the classical setting coincide with the
probability distributions that minimise Shannon's Entropy, i.e. with
distributions of zero dispersion. In the quantum setting this happens only for
particular initial conditions, which in turn correspond to classical
submanifolds. This result can be interpreted as a geometric manifestation of
the uncertainty principle.


title:
Test vectors for Waldspurger's period integral and application to the
  mass equidistribution on nonsplit torus

abstract:
  In this paper we provide local test vector for Waldspurger's period integral,
when the level of the representation $\pi_v$ is sufficiently large compared to
the level of the character $\Omega_v$ over quadratic extension, while allowing
joint ramifications. The test vectors we shall use are variants of classical
newforms, and the size of the resulting local integral is asymptotically the
inverse of convexity bound for $L(\Pi\otimes\Omega,1/2)$. Such test vectors are
used to recover Gross-Prasad type test vectors. We also get vanishing result
for local integral when using other test vectors. This phenomenon is used to
prove the mass equidistribution of cuspidal newforms on nonsplit torus in depth
aspect.


title:
Relaxing the Hypotheses of Symmetry and Time-Reversibility in Genome
  Evolutionary Models

abstract:
  Various genome evolutionary models have been proposed these last decades to
predict the evolution of a DNA sequence over time, essentially described using
a mutation matrix. By essence, all of these models relate the evolution of DNA
sequences to the computation of the successive powers of the mutation matrix.
To make this computation possible, hypotheses are assumed for the matrix, such
as symmetry and time-reversibility, which are not compatible with mutation
rates that have been recently obtained experimentally on genes ura3 and can1 of
the Yeast Saccharomyces cerevisiae. In this work, authors investigate
systematically the possibility to relax either the symmetry or the
time-reversibility hypothesis of the mutation matrix, by investigating all the
possible matrices of size 2*2 and 3*3. As an application example, the
experimental study on the Yeast Saccharomyces cerevisiae has been used in order
to deduce a simple mutation matrix, and to compute the future evolution of the
rate purine/pyrimidine for $ura3$ on the one hand, and of the particular
behavior of cytosines and thymines compared to purines on the other hand.


title:
SensibleSleep: A Bayesian Model for Learning Sleep Patterns from
  Smartphone Events

abstract:
  We propose a Bayesian model for extracting sleep patterns from smartphone
events. Our method is able to identify individuals' daily sleep periods and
their evolution over time, and provides an estimation of the probability of
sleep and wake transitions. The model is fitted to more than 400 participants
from two different datasets, and we verify the results against ground truth
from dedicated armband sleep trackers. We show that the model is able to
produce reliable sleep estimates with an accuracy of 0.89, both at the
individual and at the collective level. Moreover the Bayesian model is able to
quantify uncertainty and encode prior knowledge about sleep patterns. Compared
with existing smartphone-based systems, our method requires only screen on/off
events, and is therefore much less intrusive in terms of privacy and more
battery-efficient.


title:
Stability Results for Idealised Shear Flows on a Rectangular Periodic
  Domain

abstract:
  We present a new linearly stable solution of the Euler fluid flow on a torus.
On a two-dimensional rectangular periodic domain $[0,2\pi)\times[0,2\pi /
\kappa)$ for $\kappa\in\mathbb{R}^+$, the Euler equations admit a family of
stationary solutions given by the vorticity profiles $\Omega^*(\mathbf{x})=
\Gamma \cos(p_1x_1+ \kappa p_2x_2)$. We show linear stability for such flows
when $p_2=0$ and $\kappa \geq |p_1|$ (equivalently $p_1=0$ and
$\kappa{|p_2|}\leq{1}$). The classical result due to Arnold is that for $p_1 =
1, p_2 = 0$ and $\kappa \ge 1$ the stationary flow is {nonlinearly} stable via
the energy-Casimir method. We show that for $\kappa \ge |p_1| \ge 2, p_2 = 0$
the flow is linearly stable, but one cannot expect a similar nonlinear
stability result. Finally we prove nonlinear instability for all equilibria
satisfying $p_1^2+\kappa^2{p_2^2}>\frac{{3(\kappa^2+1)}}{4(7-4\sqrt{3})}$. The
modification and application of a structure-preserving Hamiltonian truncation
is discussed for the $\kappa\neq 1$ case. This leads to an explicit Lie-Poisson
integrator for the truncated system.


title:
ARPES observation of Mn-pnictide hybridization and negligible band
  structure renormalization in BaMn$_2$As$_2$ and BaMn$_2$Sb$_2$

abstract:
  We performed an angle-resolved photoemission spectroscopy study of
BaMn$_2$As$_2$ and BaMn$_2$Sb$_2$, which are isostructural to the parent
compound BaFe$_2$As$_2$ of the 122 family of ferropnictide superconductors. We
show the existence of a strongly $k_z$-dependent band gap with a minimum at the
Brillouin zone center, in agreement with their semiconducting properties.
Despite the half-filling of the electronic 3$d$ shell, we show that the band
structure in these materials is almost not renormalized from the Kohn-Sham
bands of density functional theory. Our photon energy dependent study provides
evidence for Mn-pnictide hybridization, which may play a role in tuning the
electronic correlations in these compounds.


title: An Incremental Parser for Abstract Meaning Representation

abstract:
  Meaning Representation (AMR) is a semantic representation for natural
language that embeds annotations related to traditional tasks such as named
entity recognition, semantic role labeling, word sense disambiguation and
co-reference resolution. We describe a transition-based parser for AMR that
parses sentences left-to-right, in linear time. We further propose a test-suite
that assesses specific subtasks that are helpful in comparing AMR parsers, and
show that our parser is competitive with the state of the art on the LDC2015E86
dataset and that it outperforms state-of-the-art parsers for recovering named
entities and handling polarity.


title: Syntomic regulators of Asai--Flach classes

abstract:
  In this paper, we derive a formula for the p-adic syntomic regulators of
Asai--Flach classes. These are cohomology classes forming an Euler system
associated to a Hilbert modular form over a quadratic field, introduced in an
earlier paper (arXiv:1607.07813) by Antonio Lei and the first and third
authors. The formula we develop here is expressed in terms of differential
operators acting on overconvergent Hilbert modular forms; it is analogous to
existing formulae for the regulators of Beilinson--Flach classes, but a novel
feature is the appearance of a projection operator associated to a
critical-slope Eisenstein series. We conclude the paper with numerical
calculations giving strong evidence for the non-vanishing of these regulators
in an explicit example.


title:
On the orthogonal rank of Cayley graphs and impossibility of quantum
  round elimination

abstract:
  After Bob sends Alice a bit, she responds with a lengthy reply. At the cost
of a factor of two in the total communication, Alice could just as well have
given the two possible replies without listening and have Bob select which
applies to him. Motivated by a conjecture stating that this form of "round
elimination" is impossible in exact quantum communication complexity, we study
the orthogonal rank and a symmetric variant thereof for a certain family of
Cayley graphs. The orthogonal rank of a graph is the smallest number $d$ for
which one can label each vertex with a nonzero $d$-dimensional complex vector
such that adjacent vertices receive orthogonal vectors.
  We show an exp$(n)$ lower bound on the orthogonal rank of the graph on
$\{0,1\}^n$ in which two strings are adjacent if they have Hamming distance at
least $n/2$. In combination with previous work, this implies an affirmative
answer to the above conjecture.


title: A hierarchy of maximal intersecting triple systems

abstract:
  We reach beyond the celebrated theorems of Erd\H{o}s-Ko-Rado and
Hilton-Milner, and, a recent theorem of Han-Kohayakawa, and determine all
maximal intersecting triples systems. It turns out that for each $n\ge7$ there
are exactly 15 pairwise non-isomorphic such systems (and 13 for $n=6$). We
present our result in terms of a hierarchy of Tur\'an numbers $\ex^{(s)}(n,
M_2^{3})$, $s\ge1$, where $M_2^{3}$ is a pair of disjoint triples. Moreover,
owing to our unified approach, we provide short proofs of the above mentioned
results (for triple systems only). The triangle $C_3$ is defined as
$C_3=\{\{x_1,y_3,x_2\},\{x_1,y_2,x_3\}, \{x_2,y_1,x_3\}\}$. Along the way we
show that the largest intersecting triple system $H$ on $n\ge6$ vertices, which
is not a star and is triangle-free, consists of $\max\{10,n\}$ triples. This
facilitates our main proof's philosophy which is to assume that $H$ contains a
copy of the triangle and analyze how the remaining edges of $H$ intersect that
copy.


title: Optimal stability estimates for continuity equations

abstract:
  This review paper is concerned with the stability analysis of the continuity
equation in the DiPerna--Lions setting in which the advecting velocity field is
Sobolev regular. Quantitative estimates for the equation were derived only
recently (Seis 2016), but optimality was not discussed. In this paper, we
revisit the results from (Seis 2016), compare the new estimates with previously
known estimates for Lagrangian flows, e.g.\ (Crippa & De Lellis 2008), and
finally demonstrate how those can be applied to produce optimal bounds in
applications from physics, engineering or numerics.


title:
Metals in the z~3 intergalactic medium: results from an ultra-high
  signal-to-noise ratio UVES quasar spectrum

abstract:
  In this work, we investigate the abundance and distribution of metals in the
intergalactic medium (IGM) at $\langle z \rangle \simeq 2.8$ through the
analysis of an ultra-high signal-to-noise ratio UVES spectrum of the quasar
HE0940-1050. In the CIV forest, our deep spectrum is sensitive at $3\,\sigma$
to lines with column density down to $\log N_{\rm CIV} \simeq 11.4$ and in 60
per cent of the considered redshift range down to $\simeq11.1$. In our sample,
all HI lines with $\log N_{\rm HI} \ge 14.8$ show an associated CIV absorption.
In the range $14.0 \le \log N_{\rm HI} <14.8$, 43 per cent of HI lines has an
associated CIV absorption. At $\log N_{\rm HI} < 14.0$, the detection rates
drop to $<10$ per cent, possibly due to our sensitivity limits and not to an
actual variation of the gas abundance properties. In the range $\log N_{\rm HI}
\ge 14$, we observe a fraction of HI lines with detected CIV a factor of 2
larger than the fraction of HI lines lying in the circum-galactic medium (CGM)
of relatively bright Lyman-break galaxies hosted by dark matter haloes with
$\langle M\rangle \sim10^{12}$ M$_{\odot}$. The comparison of our results with
the output of a grid of photoionization models and of two cosmological
simulations implies that the volume filling factor of the IGM gas enriched to a
metallicity $\log Z/Z_{\odot} \ge -3$ should be of the order of $\sim 10-13$
percent. In conclusion, our results favour a scenario in which metals are found
also outside the CGM of bright star-forming galaxies, possibly due to pollution
by lower mass objects and/or to an early enrichment by the first sources.


title: Phase Retrieval From the Magnitudes of Affine Linear Measurements

abstract:
  In this paper, we consider the phase retrieval problem in which one aims to
recover a signal from the magnitudes of affine measurements. Let $\{{\mathbf
a}_j\}_{j=1}^m \subset {\mathbb H}^d$ and ${\mathbf b}=(b_1, \ldots,
b_m)^\top\in{\mathbb H}^m$, where ${\mathbb H}={\mathbb R}$ or ${\mathbb C}$.
We say $\{{\mathbf a}_j\}_{j=1}^m$ and $\mathbf b$ are affine phase retrievable
for ${\mathbb H}^d$ if any ${\mathbf x}\in{\mathbb H}^d$ can be recovered from
the magnitudes of the affine measurements $\{|<{\mathbf a}_j,{\mathbf
x}>+b_j|,\, 1\leq j\leq m\}$. We develop general framework for affine phase
retrieval and prove necessary and sufficient conditions for $\{{\mathbf
a}_j\}_{j=1}^m$ and $\mathbf b$ to be affine phase retrievable. We establish
results on minimal measurements and generic measurements for affine phase
retrieval as well as on sparse affine phase retrieval. In particular, we also
highlight some notable differences between affine phase retrieval and the
standard phase retrieval in which one aims to recover a signal $\mathbf x$ from
the magnitudes of its linear measurements. In standard phase retrieval, one can
only recover $\mathbf x$ up to a unimodular constant, while affine phase
retrieval removes this ambiguity. We prove that unlike standard phase
retrieval, the affine phase retrievable measurements $\{{\mathbf
a}_j\}_{j=1}^m$ and $\mathbf b$ do not form an open set in ${\mathbb
H}^{m\times d}\times {\mathbb H}^m$. Also in the complex setting, the standard
phase retrieval requires $4d-O(\log_2d)$ measurements, while the affine phase
retrieval only needs $m=3d$ measurements.


title: Accretion regimes in the X-ray pulsar 4U 1901+03

abstract:
  The source 4U 1901+03 is a high-mass X-ray pulsar than went into outburst in
2003. Observation performed with the Rossi X-ray Timing Explorer showed
spectral and timing variability, including the detection of flares,
quasi-periodic oscillations, complex changes in the pulse profiles, and pulse
phase dependent spectral variability. We re-analysed the data covering the 2003
X-ray outburst and focused on several aspects of the variability that have not
been discussed so far. These are the 10 keV feature and the X-ray spectral
states and their association with accretion regimes, including the transit to
the propeller state at the end of the outburst. We find that 4U 1901+03 went
through three accretion regimes over the course of the X-ray outburst. At the
peak of the outburst and for a very short time, the X-ray flux may have
overcome the critical limit that marks the formation of a radiative shock at a
certain distance above the neutron star surface. Most of the time, however, the
source is in the subcritical regime. Only at the end of the outburst, when the
luminosity decreased below ~10^{36} (d/10 kpc)^2 erg/s, did the source enter
the propeller regime. Evidence for the existence of these regimes comes from
the pulse profiles, the shape of the hardness-intensity diagram, and the
correlation of various spectral parameters with the flux. The 10 keV feature
appears to strongly depend on the X-ray flux and on the pulse phase, which
opens the possibility to interpret this feature as a cyclotron line.


title:
Particle Physics as a way to bring different cultures to work together
  in Science

abstract:
  Science has traditionally played an important role in sharing knowledge among
people. Particle Physics, with its large experiments, has shown that one not
only can share the knowledge among different cultures, but that one can also
work together to achieve this knowledge. The present article gives a few
examples where this has been possible among people that are sometimes in
conflict situations.


title: Compact models for multidimensional quasiballistic thermal transport

abstract:
  The Boltzmann transport equation (BTE) has proven indispensable in
elucidating quasiballistic heat dynamics. Experimental observations of
nondiffusive thermal transients, however, are interpreted almost exclusively
through purely diffusive formalisms that merely extract "effective" Fourier
conductivities. Here, we build upon stochastic transport theory to provide a
characterisation framework that blends the rich physics contained within BTE
solutions with the convenience of conventional analyses. The multidimensional
phonon dynamics are described in terms of an isotropic Poissonian flight
process with rigorous Fourier-Laplace single pulse response $P(\vec{\xi},s) =
1/[s + \psi(\| \vec{\xi} \|)]$. The spatial propagator $\psi(\|\vec{\xi}\|)$,
unlike commonly reconstructed mean free path spectra
$\kappa_{\Sigma}(\Lambda)$, serves as a genuine thermal blueprint of the medium
that can be identified in compact form directly from raw measurement signals.
Practical illustrations for transient thermal grating (TTG) and time domain
thermoreflectance (TDTR) experiments on respectively GaAs and InGaAs are
provided.


title: Volatility and Arbitrage

abstract:
  The capitalization-weighted total relative variation $\sum_{i=1}^d
\int_0^\cdot \mu_i (t) \mathrm{d} \langle \log \mu_i \rangle (t)$ in an equity
market consisting of a fixed number $d$ of assets with capitalization weights
$\mu_i (\cdot)$ is an observable and nondecreasing function of time. If this
observable of the market is not just nondecreasing, but actually grows at a
rate which is bounded away from zero, then strong arbitrage can be constructed
relative to the market over sufficiently long time horizons. It has been an
open issue for more than ten years, whether such strong outperformance of the
market is possible also over arbitrary time horizons under the stated
condition. We show that this is not possible in general, thus settling this
long-open question. We also show that, under appropriate additional conditions,
outperformance over any time horizon indeed becomes possible, and exhibit
investment strategies that effect it.


title: Metallic coplanar resonators optimized for low-temperature measurements

abstract:
  Metallic coplanar microwave resonators are widely employed at room
temperature, but their low-temperature performance has received little
attention so far. We characterize compact copper coplanar resonators with
multiple modes from 2.5 to 20 GHz at temperatures as low as 5 K. We investigate
the influence of center conductor width (20 to 100 {\mu}m) and coupling gap
size (10 to 50 {\mu}m), and we observe a strong increase of quality factor (Q)
for wider center conductors, reaching values up to 470. The magnetic-field
dependence of the resonators is weak, with a maximum change in Q of 3.5% for an
applied field of 7 T. This makes these metallic resonators well suitable for
magnetic resonance studies, as we document with electron spin resonance (ESR)
measurements at multiple resonance frequencies.


title: Clustering of microscopic particles in constricted blood flow

abstract:
  A mixed suspension of red blood cells (RBCs) and microparticles flows through
a cylindrical channel with a constriction mimicking a stenosed blood vessel.
Our three-dimensional Lattice-Boltzmann simulations show that the RBCs are
depleted right ahead and after the constriction. Although the RBC mean
concentration (hematocrit) is 16.5% or 23.7%, their axial concentration profile
is very similar to that of isolated tracer particles flowing along the central
axis. Most importantly, however, we find that the stiff microparticles exhibit
the opposite behavior. Arriving on a marginated position near the channel wall,
they can pass through the constriction only if they find a suitable gap to dip
into the dense plug of RBCs occupying the channel center. This leads to a
prolonged dwell time and, as a consequence, to a pronounced increase in
microparticle concentration right in front of the constriction. For
biochemically active particles such as drug delivery agents or activated
platelets this clustering may lead to physiologically relevant hot spots of
biochemical activity.

categories: physics.flu-dyn cond-mat.soft physics.bio-ph physics.comp-ph


title:
Ultrafast Melting of Spin Density Wave Order in BaFe$_{2}$As$_{2}$
  Observed by Time- and Angle-Resolved Photoemission Spectroscopy with
  Extreme-Ultraviolet Higher Harmonic Generation

abstract:
  Transient single-particle spectral function of BaFe$_{2}$As$_{2}$, a parent
compound of iron-based superconductors, has been studied by time- and
angle-resolved photoemission spectroscopy with an extreme-ultraviolet laser
generated by higher harmonics from Ar gas, which enables us to investigate the
dynamics in the entire Brillouin zone. We observed electronic modifications
from the spin-density-wave (SDW) ordered state within $\sim$ 1 ps after the
arrival of a 1.5 eV pump pulse. We observed optically excited electrons at the
zone center above $E_{F}$ at 0.12 ps, and their rapid decay. After the fast
decay of the optically excited electrons, a thermalized state appears and
survives for a relatively long time. From the comparison with the
density-functional theory band structure for the paramagnetic and SDW states,
we interpret the experimental observations as the melting of the SDW.
Exponential decay constants for the thermalized state to recover back to the
SDW ground state are $\sim$ 0.60 ps both around the zone center and the zone
corner.


title: Representability of Chern-Weil forms

abstract:
  In this paper we look at two naturally occurring situations where the
following question arises. When one can find a metric so that a Chern-Weil form
can be represented by a given form ? The first setting is semi-stable
Hartshorne-ample vector bundles on complex surfaces where we provide evidence
for a conjecture of Griffiths by producing metrics whose Chern forms are
positive. The second scenario deals with a particular rank-2 bundle (related to
the vortex equations) over a product of a Riemann surface and the sphere.


title: Three-body antikaon-nucleon systems

abstract:
  The paper contains a review of the exact or accurate results achieved in the
field of the three-body antikaon-nucleon physics. Different states and
processes in $\bar{K}NN$ and $\bar{K}\bar{K}N$ systems are considered. In
particular, quasi-bound states in $K^- pp$ and $K^- K^- p$ systems were
investigated together with antikaonic deuterium atom. Near-threshold scattering
of antikaons on deuteron, including the $K^- d$ scattering length, and
applications of the scattering amplitudes are also discussed.
  All exact three-body results were calculated using some form of Faddeev
equations. Different versions of $\bar{K}N$, $\Sigma N$, $\bar{K}\bar{K}$, and
$NN$ potentials, specially constructed for the calculations, allowed
investigation of the dependence of the three-body results on the two-body
input. Special attention is paid to the antikaon-nucleon interaction, being the
most important for the three-body systems. Approximate calculations, performed
additionally to the exact ones, demonstrate accuracy of the commonly used
approaches.


title: The circular altitude of a graph

abstract:
  In this paper we investigate a parameter of graphs, called the circular
altitude, introduced by Peter Cameron. We show that the circular altitude
provides a lower bound on the circular chromatic number, and hence on the
chromatic number, of a graph and investigate this parameter for the iterated
Mycielskian of certain graphs.


title: Joint Subcarrier and CPU Time Allocation for Mobile Edge Computing

abstract:
  In mobile edge computing systems, mobile devices can offload
compute-intensive tasks to a nearby cloudlet,so as to save energy and extend
battery life. Unlike a fully-fledged cloud, a cloudlet is a small-scale
datacenter deployed at a wireless access point, and thus is highly constrained
by both radio and compute resources. We show in this paper that separately
optimizing the allocation of either compute or radio resource, as most existing
works did, is highly suboptimal: the congestion of compute resource leads to
the waste of radio resource, and vice versa. To address this problem, we
propose a joint scheduling algorithm that allocates both radio and compute
resources coordinately. Specifically, we consider a cloudlet in an Orthogonal
Frequency-Division Multiplexing Access (OFDMA) system with multiple mobile
devices, where we study subcarrier allocation for task offloading and CPU time
allocation for task execution in the cloudlet. Simulation results show that the
proposed algorithm significantly outperforms per-resource optimization,
accommodating more offloading requests while achieving salient energy saving.


title: Modular symmetry in magnetized/intersecting D-brane models

abstract:
  We study the modular symmetry in four-dimensional low-energy effective field
theory, which is derived from type IIB magnetized D-brane models and type IIA
intersecting D-brane models. We analyze modular symmetric behaviors of
perturbative terms and non-perturbative terms induced by D-brane instanton
effects. Anomalies are also investigated and such an analysis on anomalies
suggests corrections in effective field theory.


title: Monadic Datalog Containment on Trees Using the Descendant-Axis

abstract:
  In their AMW14-paper, Frochaux, Grohe, and Schweikardt showed that the query
containment problem for monadic datalog on finite unranked labeled trees is
Exptime-complete when (a) considering unordered trees using the child-axis, and
when (b) considering ordered trees using the axes firstchild, nextsibling, and
child. Furthermore, when allowing to use also the descendant-axis, the query
containment problem was shown to be solvable in 2-fold exponential time, but it
remained open to determine the problems exact complexity in presence of the
descendant-axis. The present paper closes this gap by showing that, in the
presence of the descendant-axis, the problem is 2Exptime-hard.


title: The feedback of atomic jets from embedded protostars in NGC 1333

abstract:
  Star-formation feedback onto the parent cloud is conventionally examined
through the study of molecular outflows. Little is however known on the effect
that atomic ejecta, tracing fast shocks, can have on the global cloud
properties. In this study we employ Herschel/PACS [OI] and [CII] spectral line
maps of the NGC 1333 star-forming region to assess the relative influence of
atomic jets onto the star-formation process. Atomic line maps are compared
against molecular outflow tracers and atomic ejecta are associated to
individual driving sources. We study the detailed morphology and velocity
distribution of [OI] line using channel and line-centroid maps and derive the
momentum, energy, and mass flux for all the bipolar jets traced by [OI] line
emission. We find that the line-centroid maps can trace velocity structures
down to 5 km s$^{-1}$ which is a factor of $\sim$20 beyond the nominal velocity
resolution reached by Herschel/PACS. These maps reveal an unprecedented degree
of details that assist significantly in the association and characterization of
jets and outflows. Comparisons of the dynamical and kinematical properties
shows that [OI] momentum accounts for only $\sim$1% of the momentum carried by
the large scale CO outflows but the energy released through the jets
corresponds to 50 - 100% of the energy released in outflows. The estimated
ratios of the jet to the outflow momenta and energies are consistent with the
results of two-component, nested jet/outflow simulations, where jets are
associated to episodic accretion events. Under this scenario, the energy from
atomic jets to the cloud is as important as the energy output from outflows in
maintaining turbulence and dissipating the cloud gas.


title:
Reconstructing Neural Parameters and Synapses of arbitrary
  interconnected Neurons from their Simulated Spiking Activity

abstract:
  To understand the behavior of a neural circuit it is a presupposition that we
have a model of the dynamical system describing this circuit. This model is
determined by several parameters, including not only the synaptic weights, but
also the parameters of each neuron. Existing works mainly concentrate on either
the synaptic weights or the neural parameters. In this paper we present an
algorithm to reconstruct all parameters including the synaptic weights of a
spiking neuron model. The model based on works of Eugene M. Izhikevich
(Izhikevich 2007) consists of two differential equations and covers different
types of cortical neurons. It combines the dynamical properties of
Hodgkin-Huxley-type dynamics with a high computational efficiency. The
presented algorithm uses the recordings of the corresponding membrane
potentials of the model for the reconstruction and consists of two main
components. The first component is a rank based Genetic Algorithm (GA) which is
used to find the neural parameters of the model. The second one is a Least Mean
Squares approach which computes the synaptic weights of all interconnected
neurons by minimizing the squared error between the calculated and the measured
membrane potentials for each time step. In preparation for the reconstruction
of the neural parameters and of the synaptic weights from real measured
membrane potentials, promising results based on simulated data generated with a
randomly parametrized Izhikevich model are presented. The reconstruction does
not only converge to a global minimum of neural parameters, but also
approximates the synaptic weights with high precision.


title:
A Combined Dependability and Security Approach for Third Party Software
  in Space Systems

abstract:
  Software components for on-board architectures in the space domain are
increasingly reliant on Commercial Off-The-Shelf (COTS), Open Source (OSS) or
other third party software products. However, these software components often
have not been built with mission critical requirements in mind. Development
project teams incorporating these products have limited knowledge of or control
over the processes applied during the design, implementation, testing and
maintenance of selected COTS/OSS software products. These constraints generate
uncertainty of potential software induced failures. Moreover, the lack of
information regarding security vulnerabilities increases the risks of their
usage, since their exploitation might lead to undesired behaviour of the
software and therefore to a system failure. The purpose of this paper is to
present a combined approach that takes into account reliability and security
enhancements for third party software, based on Time-Space Partitioning and
Multiple Levels of Security.


title:
Median-Based Generation of Synthetic Speech Durations using a
  Non-Parametric Approach

abstract:
  This paper proposes a new approach to duration modelling for statistical
parametric speech synthesis in which a recurrent statistical model is trained
to output a phone transition probability at each timestep (acoustic frame).
Unlike conventional approaches to duration modelling -- which assume that
duration distributions have a particular form (e.g., a Gaussian) and use the
mean of that distribution for synthesis -- our approach can in principle model
any distribution supported on the non-negative integers. Generation from this
model can be performed in many ways; here we consider output generation based
on the median predicted duration. The median is more typical (more probable)
than the conventional mean duration, is robust to training-data irregularities,
and enables incremental generation. Furthermore, a frame-level approach to
duration prediction is consistent with a longer-term goal of modelling
durations and acoustic features together. Results indicate that the proposed
method is competitive with baseline approaches in approximating the median
duration of held-out natural speech.


title: Resolution of ranking hierarchies in directed networks

abstract:
  Identifying hierarchies and rankings of nodes in directed graphs is
fundamental in many applications such as social network analysis, biology,
economics, and finance. A recently proposed method identifies the hierarchy by
finding the ordered partition of nodes which minimises a score function, termed
agony. This function penalises the links violating the hierarchy in a way
depending on the strength of the violation. To investigate the resolution of
ranking hierarchies we introduce an ensemble of random graphs, the Ranked
Stochastic Block Model. We find that agony may fail to identify hierarchies
when the structure is not strong enough and the size of the classes is small
with respect to the whole network. We analytically characterise the resolution
threshold and we show that an iterated version of agony can partly overcome
this resolution limit.


title: A Linear Kernel for Finding Square Roots of Almost Planar Graphs

abstract:
  A graph H is a square root of a graph G if G can be obtained from H by the
addition of edges between any two vertices in H that are of distance 2 from
each other. The Square Root problem is that of deciding whether a given graph
admits a square root. We consider this problem for planar graphs in the context
of the "distance from triviality" framework. For an integer k, a planar+kv
graph (or k-apex graph) is a graph that can be made planar by the removal of at
most k vertices. We prove that a generalization of Square Root, in which some
edges are prescribed to be either in or out of any solution, has a kernel of
size O(k) for planar+kv graphs, when parameterized by k. Our result is based on
a new edge reduction rule which, as we shall also show, has a wider
applicability for the Square Root problem.


title:
Minimal relations and the Diophantine Frobenius Problem in embedding
  dimension three

abstract:
  This paper provides a formula for the minimal relations and the Frobenius
number of a numerical semigroup minimally generated by three pairwise coprime
positive integers.


title:
Stochastic resonance in a sinusoidal potential system: An analog
  simulation experiment

abstract:
  Recently, stochastic resonance was obtained numerically in an underdamped
periodic potential system driven by a periodic force and a Gaussian white
noise. In that numerical work, the occurrence of stochastic resonance was
explained in terms of the existence of two dynamical states having different
amplitude and phase lag. At zero temperature these two initial condition
dependent dynamical states are stable. However, at elevated temperatures, these
two states make transitions from one to the other at a mean rate. In the
present work, we setup an analog simulation experiment to show the existence of
the two dynamical states in a sinusoidal potential system as well as to verify
the occurrence of stochastic resonance in the same system. The experimental
procedure includes setting the initial conditions for the experiment.


title: Z(3) metastable states in Polyakov Quark Meson model

abstract:
  We study the existence of Z(3) metastable states in the presence of the
dynamical quarks within the ambit of Polyakov quark meson (PQM) model. Within
the parameters of the model, it is seen that for temperatures $T_m$ greater
than the chiral transition temperature $T_c$, Z(3) metastable states exist (
$T_{m} \sim 310$ MeV at zero chemical potential). At finite chemical potential
$T_m$ is larger than the same at vanishing chemical potential. We also observe
a shift of ($\sim 5^\circ$) in the phase of the metastable vacua at zero
chemical potential. The energy density difference between true and Z(3)
metastable vacua is very large in this model. This indicates a strong explicit
symmetry breaking effect due to quarks in PQM model. We compare this explicit
symmetry breaking in PQM model with small explicit symmetry breaking as a
linear term in Polyakov loop added to the Polyakov loop potential. We also
study about the possibility of domain growth in a quenched transition to QGP in
relativistic heavy ion collisions.


title:
Restriction of irreducible modules for $\mbox{Spin}_{2n+1}(K)$ to
  $\mbox{Spin}_{2n}(K)$

abstract:
  Let $K$ be an algebraically closed field of characteristic $p\geqslant 0$ and
let $Y=\mbox{Spin}_{2n+1}(K)$ $(n\geqslant 3)$ be a simply connected simple
algebraic group of type $B_n$ over $K.$ Also let $X$ be the subgroup of type
$D_n,$ embedded in $Y$ in the usual way, as the derived subgroup of the
stabilizer of a non-singular one-dimensional subspace of the natural module for
$Y.$ In this paper, we give a complete set of isomorphism classes of
finite-dimensional, irreducible, rational $KY$-modules on which $X$ acts with
exactly two composition factors.


title: A persistent particle ontology for QFT in terms of the Dirac sea

abstract:
  We show that the Bohmian approach in terms of persisting particles that move
on continuous trajectories following a deterministic law can be literally
applied to QFT. By means of the Dirac sea model -- exemplified in the electron
sector of the standard model neglecting radiation -- we explain how starting
from persisting particles, one is led to standard QFT employing creation and
annihilation operators when tracking the dynamics with respect to a reference
state, the so-called vacuum. Since on the level of wave functions, both
formalisms are mathematically equivalent, this proposal provides for an
ontology of QFT that includes a dynamics of individual processes, solves the
measurement problem and explains the appearance of creation and annihilation
events.


title: Squares of Low Maximum Degree

abstract:
  A graph H is a square root of a graph G if G can be obtained from H by adding
an edge between any two vertices in H that are of distance 2. The Square Root
problem is that of deciding whether a given graph admits a square root. This
problem is only known to be NP-complete for chordal graphs and polynomial-time
solvable for non-trivial minor-closed graph classes and a very limited number
of other graph classes. We prove that Square Root is O(n)-time solvable for
graphs of maximum degree 5 and O(n^4)-time solvable for graphs of maximum
degree at most 6.


title:
Object Depth Profile and Reflectivity Restoration from Sparse
  Single-Photon Data Acquired in Underwater Environments

abstract:
  This paper presents two new algorithms for the joint restoration of depth and
reflectivity (DR) images constructed from time-correlated single-photon
counting (TCSPC) measurements. Two extreme cases are considered: (i) a reduced
acquisition time that leads to very low photon counts and (ii) a highly
attenuating environment (such as a turbid medium) which makes the reflectivity
estimation more difficult at increasing range. Adopting a Bayesian approach,
the Poisson distributed observations are combined with prior distributions
about the parameters of interest, to build the joint posterior distribution.
More precisely, two Markov random field (MRF) priors enforcing spatial
correlations are assigned to the DR images. Under some justified assumptions,
the restoration problem (regularized likelihood) reduces to a convex
formulation with respect to each of the parameters of interest. This problem is
first solved using an adaptive Markov chain Monte Carlo (MCMC) algorithm that
approximates the minimum mean square parameter estimators. This algorithm is
fully automatic since it adjusts the parameters of the MRFs by maximum marginal
likelihood estimation. However, the MCMC-based algorithm exhibits a relatively
long computational time. The second algorithm deals with this issue and is
based on a coordinate descent algorithm. Results on single-photon depth data
from laboratory based underwater measurements demonstrate the benefit of the
proposed strategy that improves the quality of the estimated DR images.


title: DETOx: Towards Optimal Software-based Soft-Error Detector Configurations

abstract:
  Application developers often place executable assertions -- equipped with
program-specific predicates -- in their system, targeting programming errors.
However, these detectors can detect data errors resulting from transient
hardware faults in main memory as well. But while an assertion reduces silent
data corruptions (SDCs) in the program state they check, they add runtime to
the target program that increases the attack surface for the remaining state.
This article outlines an approach to find an optimal subset of assertions that
minimizes the SDC count, without the need to run fault-injection experiments
for every possible assertion subset.


title: Geometric criterion for separability based on local measurement

abstract:
  A geometric understanding of entanglement is proposed based on local
measurements. Taking recourse to the general structure of density matrices in
the framework of Euclidean geometry, we first illustrate our approach for
bipartite Werner states. It is demonstrated that separable states satisfy
certain geometric constraints that entangled states do not. A separability
criterion for multiparty Werner states of arbitrary dimension is derived. This
approach can be used to determine separability across any bipartition of a
general density matrix and leads naturally to a computable measure of
entanglement for multiparty pure states. It is known that all density matrices
within a certain distance of the normalized identity are separable. This
distance is determined for a general setting of $n$ qudits, each of dimension
$d$.


title:
The Role of the Hes1 Crosstalk Hub in Notch-Wnt Interactions of the
  Intestinal Crypt

abstract:
  The Notch pathway plays a vital role in determining whether cells in the
intestinal epithelium adopt a secretory or an absorptive phenotype. Cell fate
specification is coordinated via Notch's interaction with the canonical Wnt
pathway. Here, we propose a new mathematical model of the Notch and Wnt
pathways, in which the Hes1 promoter acts as a hub for pathway crosstalk.
Computational simulations of the model can assist in understanding how healthy
intestinal tissue is maintained, and predict the likely consequences of
biochemical knockouts upon cell fate selection processes. Chemical reaction
network theory (CRNT) is a powerful, generalised framework which assesses the
capacity of our model for monostability or multistability, by analysing
properties of the underlying network structure without recourse to specific
parameter values or functional forms for reaction rates. CRNT highlights the
role of beta-catenin in stabilising the Notch pathway and damping oscillations,
demonstrating that Wnt-mediated actions on the Hes1 promoter can induce
dynamical transitions in the Notch system, from multistability to
monostability. Time-dependent model simulations of cell pairs reveal the
stabilising influence of Wnt upon the Notch pathway, in which beta-catenin- and
Dsh-mediated action on the Hes1 promoter are key in shaping the subcellular
dynamics. Where Notch-mediated transcription of Hes1 dominates, there is Notch
oscillation and maintenance of fate flexibility; Wnt-mediated transcription of
Hes1 favours bistability akin to cell fate selection. Cells could therefore
regulate the proportion of Wnt- and Notch-mediated control of the Hes1 promoter
to coordinate the timing of cell fate selection as they migrate through the
intestinal epithelium and are subject to reduced Wnt stimuli.


title: Black hole chemistry: thermodynamics with Lambda

abstract:
  We review recent developments on the thermodynamics of black holes in
extended phase space, where the cosmological constant is interpreted as
thermodynamic pressure and treated as a thermodynamic variable in its own
right. In this approach, the mass of the black hole is no longer regarded as
internal energy, rather it is identified with the chemical enthalpy. This leads
to an extended dictionary for black hole thermodynamic quantities, in
particular a notion of thermodynamic volume emerges for a given black hole
spacetime. This volume is conjectured to satisfy the reverse isoperimetric
inequality - an inequality imposing a bound on the amount of entropy black hole
can carry for a fixed thermodynamic volume. New thermodynamic phase transitions
naturally emerge from these identifications. Namely, we show that black holes
can be understood from the viewpoint of chemistry, in terms of concepts such as
Van der Waals fluids, reentrant phase transitions, and triple points. We also
review the recent attempts at extending the AdS/CFT dictionary in this setting,
discuss the connections with horizon thermodynamics, applications to Lifshitz
spacetimes, and outline possible future directions in this field.


title:
Multiple objects tracking in surveillance video using color and Hu
  moments

abstract:
  Multiple objects tracking finds its applications in many high level vision
analysis like object behaviour interpretation and gait recognition. In this
paper, a feature based method to track the multiple moving objects in
surveillance video sequence is proposed. Object tracking is done by extracting
the color and Hu moments features from the motion segmented object blob and
establishing the association of objects in the successive frames of the video
sequence based on Chi-Square dissimilarity measure and nearest neighbor
classifier. The benchmark IEEE PETS and IEEE Change Detection datasets has been
used to show the robustness of the proposed method. The proposed method is
assessed quantitatively using the precision and recall accuracy metrics.
Further, comparative evaluation with related works has been carried out to
exhibit the efficacy of the proposed method.


title:
Convergence of a mixed finite element finite volume scheme for the
  isentropic Navier-Stokes system via dissipative measure-valued solutions

abstract:
  We study convergence of a mixed finite element finite volume numerical scheme
for the isentropic Navier-Stokes system under the full range of the adiabatic
exponent. We establish suitable stability and consistency estimates and show
that the Young measure generated by numerical solutions represents a
dissipative measure-valued solutions of the limit system. In particular, using
the recently established weak{strong uniqueness principle in the class of
dissipative measure-valued solutions we show that the numerical solutions
converge strongly to a strong solutions of the limit system as long as the
latter exists.


title: Crab Waist collision scheme: a novel approach for particle colliders

abstract:
  A new concept of nonlinear focusing of colliding bunches, called Crab Waist
(CW)collision scheme, has been proposed at LNF INFN. It has been successfully
tested at the Italian lepton collider DAFNE in operational conditions providing
luminosity for two different experimental detectors, SIDDHARTA and KLOE-2.
Considering a high efficiency of the scheme for increasing collision luminosity
and its relative simplicity for implementation several new collider projects
have been proposed and are under development at present. These are the
SuperKEKB B-factory ready to start commissioning in 2016 in Japan, the
SuperC-Tau factory proposed in Novosibirsk and entered in the short list of
Russian mega-science projects, the new 100-km electron-positron Future Circular
Collider (FCC-ee) under design study at CERN and some others. In this paper we
describe the CW collision scheme, discuss its advantages and report principal
results achieved at the electron-positron Phi-factory DAFNE.


title:
Local and Global Existence of Strong Solutions to Large Cross Diffusion
  Systems

abstract:
  We study the solvability of a general class of cross diffusion systems and
establish the local and global existence of their strong solutions under the
weakest assumption that they are VMO. This work simplifies the setting in our
previous work [16] and provides new extensions which are more verifiable in
applications.


title: Quantum back-action evading measurement of collective mechanical modes

abstract:
  The standard quantum limit constrains the precision of an oscillator position
measurement. It arises from a balance between the imprecision and the quantum
back-action of the measurement. However, a measurement of only a single
quadrature of the oscillator can evade the back-action and be made with
arbitrary precision. Here we demonstrate quantum back-action evading
measurements of a collective quadrature of two mechanical oscillators, both
coupled to a common microwave cavity. The work allows for quantum state
tomography of two mechanical oscillators, and provides a foundation for
macroscopic mechanical entanglement and force sensing beyond conventional
quantum limits.


title:
Noncommutative coherent states and related aspects of Berezin-Toeplitz
  quantization

abstract:
  In~this paper, we construct noncommutative coherent states using various
families of unitary irreducible representations (UIRs) of $\g$, a connected,
simply connected nilpotent Lie group, that was identified as the kinematical
symmetry group of noncommutative quantum mechanics for a system of 2-degrees of
freedom in an earlier paper. Likewise described are the degenerate
noncommutative coherent states arising from the degenerate UIRs of $\g$.
We~then compute the reproducing kernels associated with both these families of
coherent states and study Berezin-Toeplitz quantization of the observables on
the underlying 4-dimensional phase space, analyzing in particular the
semi-classical asymptotics for both these cases.


title:
Multi-Sensor Prognostics using an Unsupervised Health Index based on
  LSTM Encoder-Decoder

abstract:
  Many approaches for estimation of Remaining Useful Life (RUL) of a machine,
using its operational sensor data, make assumptions about how a system degrades
or a fault evolves, e.g., exponential degradation. However, in many domains
degradation may not follow a pattern. We propose a Long Short Term Memory based
Encoder-Decoder (LSTM-ED) scheme to obtain an unsupervised health index (HI)
for a system using multi-sensor time-series data. LSTM-ED is trained to
reconstruct the time-series corresponding to healthy state of a system. The
reconstruction error is used to compute HI which is then used for RUL
estimation. We evaluate our approach on publicly available Turbofan Engine and
Milling Machine datasets. We also present results on a real-world industry
dataset from a pulverizer mill where we find significant correlation between
LSTM-ED based HI and maintenance costs.


title:
An Energy Estimate for Dislocation Configurations and the Emergence of
  Cosserat-Type Structures in Metal Plasticity

abstract:
  We investigate low energy structures of a lattice with dislocations in the
context of nonlinear elasticity. We show that these low energy configurations
exhibit in the limit a Cosserat-like behavior. Moreover, we give bounds from
above and below to the energy of such configurations.


title:
Molecular beam epitaxy of InAs nanowires in SiO2 nanotube templates:
  challenges and prospects for integration of III-Vs on Si

abstract:
  Guided growth of semiconductor nanowires in nanotube templates has been
considered as a potential platform for reproducible integration of III-Vs on
silicon or other mismatched substrates. Herein, we report on the challenges and
prospects of molecular beam epitaxy of InAs nanowires on SiO2/Si nanotube
templates. We show how and under which conditions the nanowire growth is
initiated by In-assisted vapor-liquid-solid growth enabled by the local
conditions inside the nanotube template. The conditions for high yield of
vertical nanowires are investigated in terms of the nanotube depth, diameter
and V/III flux ratios. We present a model that further substantiates our
findings. This work opens new perspectives for monolithic integration of III-Vs
on the silicon platform enabling new applications in the electronics,
optoelectronics and energy harvesting arena.


title:
The Spin-Half {\it XXZ} Antiferromagnet on the Square Lattice Revisited:
  A High-Order Coupled Cluster Treatment

abstract:
  We use the coupled cluster method (CCM) to study the ground-state properties
and lowest-lying triplet excited state of the spin-half {\it XXZ}
antiferromagnet on the square lattice. The CCM is applied to it to high orders
of approximation by using an efficient computer code that has been written by
us and which has been implemented to run on massively parallelized computer
platforms. We are able therefore to present precise data for the basic
quantities of this model over a wide range of values for the anisotropy
parameter $\Delta$ in the range $-1 \leq \Delta < \infty$ of interest,
including both the easy-plane $(-1 < \Delta < 1)$ and easy-axis $(\Delta > 1)$
regimes, where $\Delta \rightarrow \infty$ represents the Ising limit. We
present results for the ground-state energy, the sublattice magnetization, the
zero-field transverse magnetic susceptibility, the spin stiffness, and the
triplet spin gap. Our results provide a useful yardstick against which other
approximate methods and/or experimental studies of relevant antiferromagnetic
square-lattice compounds may now compare their own results. We also focus
particular attention on the behaviour of these parameters for the easy-axis
system in the vicinity of the isotropic Heisenberg point ($\Delta = 1$), where
the model undergoes a phase transition from a gapped state (for $\Delta > 1$)
to a gapless state (for $\Delta \leq 1$), and compare our results there with
those from spin-wave theory (SWT). Interestingly, the nature of the criticality
at $\Delta=1$ for the present model with spins of spin quantum number
$s=\frac{1}{2}$ that is revealed by our CCM results seems to differ
qualitatively from that predicted by SWT, which becomes exact only for its
near-classical large-$s$ counterpart.


title: Water around IRAS15398-3359 observed with ALMA

abstract:
  How protostars accrete mass is one of the fundamental problems of star
formation. High column densities and complex kinematical structures make direct
observations challenging and they only provide a snapshot. Chemical tracers
provide an interesting alternative to characterise the infall histories of
protostars. Previous observations of H13CO+ towards the low-mass protostar
IRAS15398-3359 showed a depression in the abundance. This is a sign of
destruction of HCO+ by an enhanced presence of gaseous water in an extended
region, possibly related to a recent burst in the accretion. Direct
observations of water vapour can determine the exact extent of the emission and
confirm the hypothesis that HCO+ is indeed a good tracer of the water
snow-line. IRAS15398 was observed using ALMA at 0.5" resolution. Maps of
HDO(101-000) and H218O(414-321) were taken simultaneously with observations of
the CS(8-7) and N2H+(5-4) lines and continuum at 0.65 and 0.75 mm. The maps
were interpreted using dust radiative transfer calculations of the protostellar
infalling envelope with an outflow cavity. HDO is clearly detected and extended
over the scales of the H13CO+ depression, although it is displaced by ~500 AU
in the direction of the outflow. H218O is tentatively detected towards the
red-shifted outflow lobe, but otherwise it is absent from the mapped region,
which suggests that temperatures are low. Based on the temperature structure
obtained from dust radiative transfer models, we conclude that the water was
most likely released from the grains in an extended hour-glass configuration
during a recent accretion burst. HDO is only detected in the region closest to
the protostar, at distances of up to 500 AU. These signatures can only be
explained if the luminosity has recently been increased by orders of
magnitudes. Additionally, the densities in the outflow cones must be
sufficiently low.


title: Total-variation regularization strategies in full-waveform inversion

abstract:
  We propose an extended full-waveform inversion formulation that includes
general convex constraints on the model. Though the full problem is highly
nonconvex, the overarching optimization scheme arrives at geologically
plausible results by solving a sequence of relaxed and warm-started constrained
convex subproblems. The combination of box, total-variation, and successively
relaxed asymmetric total-variation constraints allows us to steer free from
parasitic local minima while keeping the estimated physical parameters
laterally continuous and in a physically realistic range. For accurate starting
models, numerical experiments carried out on the challenging 2004 BP velocity
benchmark demonstrate that bound and total-variation constraints improve the
inversion result significantly by removing inversion artifacts, related to
source encoding, and by clearly improved delineation of top, bottom, and flanks
of a high-velocity high-contrast salt inclusion. The experiments also show that
for poor starting models these two constraints by themselves are insufficient
to detect the bottom of high-velocity inclusions such as salt. Inclusion of the
one-sided asymmetric total-variation constraint overcomes this issue by
discouraging velocity lows to buildup during the early stages of the inversion.
To the author's knowledge the presented algorithm is the first to successfully
remove the imprint of local minima caused by poor starting models and
band-width limited finite aperture data.


title: Bilinear Forms with Kloosterman and Gauss Sums

abstract:
  We obtain several estimates for bilinear form with Kloosterman sums. Such
results can be interpreted as a measure of cancellations amongst with
parameters from short intervals. In particular, for certain ranges of
parameters we improve some recent results of Blomer, Fouvry, Kowalski, Michel
and Mili\'cevi\'c and also of Fouvry, Kowalski and Michel. In particular, we
improve the bound on the error term in the asymptotic formula for mixed moments
of $L$-series associated with Hecke eigenforms.


title: Elliptic Hypergeometric Functions

abstract:
  In these lecture notes I give an elementary introduction to elliptic
hypergeometric functions. I focus on motivating the main ideas and
constructions, rather than giving a comprehensive survey. The lectures include
a brief explanation of the historical origin of elliptic hypergeometric
functions in the context of solvable lattice models. In particular, I give a
new proof of the fact that fused Boltzmann weights for the elliptic
solid-on-solid model can be expressed as elliptic hypergeometric sums.

categories: math.CA cond-mat.stat-mech math-ph math.MP


title: Coupled dynamics for superfluid $^4$He in the channel

abstract:
  We study the coupled dynamics of normal and superfluid components of the
superfluid $^4$He in the channel considering the counterflow turbulence with
laminar normal component. In particular, we calculated profiles of the normal
velocity, the mutual friction, the vortex line density and other flow
properties and compared them to the case when the dynamic of the normal
component is "frozen". We have found that the coupling between the normal and
superfluid components leads to flattening of the normal velocity profile,
increasingly more pronounced with temperature, as the mutual friction, and
therefore coupling, becomes stronger. The commonly measured flow properties
also change when the coupling between two components is taken into account.


title: Late-time Structure of the Bunch-Davies FRW Wavefunction

abstract:
  In this short note we organize a perturbation theory for the Bunch-Davies
wavefunction in flat, accelerating cosmologies. The calculational technique
avoids the in-in formalism and instead uses an analytic continuation from
Euclidean signature. We will consider both massless and conformally coupled
self-interacting scalars. These calculations explicitly illustrate two facts.
The first is that IR divergences get sharper as the acceleration slows. The
second is that UV-divergent contact terms in the Euclidean computation can
contribute to the absolute value of the wavefunction in Lorentzian signature.
Here UV divergent refers to terms involving inverse powers of the radial cutoff
in the Euclidean computation. In Lorentzian signature such terms encode
physical time dependence of the wavefunction.


title:
Variational approach to low-frequency kinetic-MHD in the current
  coupling scheme

abstract:
  Hybrid kinetic-MHD models describe the interaction of an MHD bulk fluid with
an ensemble of hot particles, which is described by a kinetic equation. When
the Vlasov description is adopted for the energetic particles, different
Vlasov-MHD models have been shown to lack an exact energy balance, which was
recently recovered by the introduction of non-inertial force terms in the
kinetic equation. These force terms arise from fundamental approaches based on
Hamiltonian and variational methods. In this work we apply Hamilton's
variational principle to formulate new current-coupling kinetic-MHD models in
the low-frequency approximation (i.e. large Larmor frequency limit). More
particularly, we formulate current-coupling hybrid schemes, in which energetic
particle dynamics are expressed in either guiding-center or gyrocenter
coordinates.


title: Quasi-local mass at the null infinity of the Vaidya spacetime

abstract:
  There are two important statements regarding the Trautman-Bondi mass [1,8,5]
at null infinity: one is the positivity [7,6], and the other is the Bondi mass
loss formula [1], which are both global in nature. The positivity of the
quasi-local mass can potentially lead to a local description at null infinity.
This is confirmed for the Vaidya spacetime in this note. We study the Wang-Yau
quasi-local mass on surfaces of fixed size at the null infinity of the Vaidya
spacetime. The optimal embedding equation is solved explicitly and the
quasi-local mass is evaluated in terms of the mass aspect function of the
Vaidya spacetime.


title:
Optimal Demand Side Management by Distributed and Secured Energy
  Commitment Framework

abstract:
  This paper introduces a demand-side distributed and secured energy commitment
framework and operations for a Power Producer and Supplier (PPS) in deregulated
environment. Due to the diversity of geographical location as well as
customers' energy profile coupled with high number of customers, managing
energy transactions and resulting energy exchanges are challenging for a PPS.
The envisioned PPS maintains several aggregators (e.g. Microgrids), named as
Sub Service Provider (SSP) that manage customers/subscribers under their
domains. The SSPs act as agents that perform local energy matching (inside
their domains) and distributed energy matching within SSPs to determine the
energy commitment. The goal of the distributed energy matching is to reduce the
involvement of External Energy Supplier (e.g. Utility) while providing a
platform to demand side players to be a part of energy transaction. A
distributed assignment problem is designed that requires minimum and aggregated
information exchange (hence, secured) and solved by Linear Programming (LP)
that provides the distributed matching decision. The communicative burden among
SSPs due to the exchange of energy information is reduced by applying an
adaptive coalition formation method. The simulations are conducted by
implementing a synchronous distributed matching algorithm while showing the
effectiveness of the proposed framework.


title: On finite-dimensional copointed Hopf algebras over dihedral groups

abstract:
  We classify all finite-dimensional Hopf algebras over an algebraically closed
field of characteristic zero such that its coradical is isomorphic to the
algebra of functions over a dihedral group D_m, with m=4a> 11. We obtain this
classification by means of the lifting method, where we use cohomology theory
to determine all possible deformations. Our result provides an infinite family
of new examples of finite-dimensional copointed Hopf algebras over dihedral
groups.


title:
On Spectrum and Infrastructure Sharing in Multi-Operator Cellular
  Networks

abstract:
  In this paper, we introduce a mathematical framework for analyzing and
optimizing multi-operator cellular networks that are allowed to share spectrum
licenses and infrastructure elements. The proposed approach exploits stochastic
geometry for modeling the locations of cellular base stations and for computing
the aggregate average rate. The trade-offs that emerge from sharing spectrum
frequencies and cellular base stations are quantified and discussed.


title:
Effective and Complete Discovery of Order Dependencies via Set-based
  Axiomatization

abstract:
  Integrity constraints (ICs) provide a valuable tool for expressing and
enforcing application semantics. However, formulating constraints manually
requires domain expertise, is prone to human errors, and may be excessively
time consuming, especially on large datasets. Hence, proposals for automatic
discovery have been made for some classes of ICs, such as functional
dependencies (FDs), and recently, order dependencies (ODs). ODs properly
subsume FDs, as they can additionally express business rules involving order;
e.g., an employee never has a higher salary while paying lower taxes compared
with another employee.
  We address the limitations of prior work on OD discovery which has factorial
complexity in the number of attributes, is incomplete (i.e., it does not
discover valid ODs that cannot be inferred from the ones found) and is not
concise (i.e., it can result in "redundant" discovery and overly large
discovery sets). We improve significantly on complexity, offer completeness,
and define a compact canonical form. This is based on a novel polynomial
mapping to a canonical form for ODs, and a sound and complete set of axioms
(inference rules) for canonical ODs. This allows us to develop an efficient
set-containment, lattice-driven OD discovery algorithm that uses the inference
rules to prune the search space. Our algorithm has exponential worst-case time
complexity in the number of attributes and linear complexity in the number of
tuples. We prove that it produces a complete, minimal set of ODs (i.e., minimal
with regards to the canonical representation). Finally, using real and
synthetic datasets, we experimentally show orders-of-magnitude performance
improvements over the current state-of-the-art algorithm and demonstrate
effectiveness of our techniques.


title:
Tur\'an problems for digraphs avoiding distinct walks of a given length
  with the same endpoints

abstract:
  Let $n \ge 5$ and $k\ge 4$ be positive integers. We determine the maximum
size of digraphs of order n that avoid distinct walks of length k with the same
endpoints. We also characterize the extremal digraphs attaining this maximum
number when $k \ge 5$.


title:
MISO: An intermediate language to express parallel and dependable
  programs

abstract:
  One way to write fast programs is to explore the potential parallelism and
take advantage of the high number of cores available in microprocessors. This
can be achieved by manually specifying which code executes on which thread, by
using compiler parallelization hints (such as OpenMP or Cilk), or by using a
parallel programming language (such as X10, Chapel or Aeminium. Regardless of
the approach, all of these programs are compiled to an intermediate lower-level
language that is sequential, thus preventing the backend compiler from
optimizing the program and observing its parallel nature. This paper presents
MISO, an intermediate language that expresses the parallel nature of programs
and that can be targeted by front-end compilers. The language defines 'cells',
which are composed by a state and a transition function from one state to the
next. This language can express both sequential and parallel programs, and
provides information for a backend- compiler to generate efficient parallel
programs. Moreover, MISO can be used to automatically add redundancy to a
program, by replicating the state or by taking advantage of different processor
cores, in order to provide fault tolerance for programs running on unreliable
hardware.


title:
On the Origin of Samples: Attribution of Output to a Particular
  Algorithm

abstract:
  With unprecedented advances in genetic engineering we are starting to see
progressively more original examples of synthetic life. As such organisms
become more common it is desirable to be able to distinguish between natural
and artificial life forms. In this paper, we present this challenge as a
generalized version of Darwin's original problem, which he so brilliantly
addressed in On the Origin of Species. After formalizing the problem of
determining origin of samples we demonstrate that the problem is in fact
unsolvable, in the general case, if computational resources of considered
originator algorithms have not been limited and priors for such algorithms are
known to be equal. Our results should be of interest to astrobiologists and
scientists interested in producing a more complete theory of life, as well as
to AI-Safety researchers.


title: Compression and ablation of the photo-irradiated cloud the Orion Bar

abstract:
  The Orion Bar is the archetypal edge-on molecular cloud surface illuminated
by strong ultraviolet radiation from nearby massive stars. Owing to the close
distance to Orion (about 1,350 light-year), the effects of stellar feedback on
the parental cloud can be studied in detail. Visible-light observations of the
Bar(1) show that the transition between the hot ionised gas and the warm
neutral atomic gas (the ionisation front) is spatially well separated from the
transition from atomic to molecular gas (the dissociation front): about 15
arcseconds or 6,200 astronomical units (one astronomical unit is the Earth-Sun
distance). Static equilibrium models(2,3) used to interpret previous
far-infrared and radio observations of the neutral gas in the Bar(4,5,6)
(typically at 10-20 arcsecond resolution) predict an inhomogeneous cloud
structure consisting of dense clumps embedded in a lower density extended gas
component. Here we report one-arcsecond-resolution millimetre-wave images that
allow us to resolve the molecular cloud surface. In contrast to stationary
model predictions(7,8,9), there is no appreciable offset between the peak of
the H2 vibrational emission (delineating the H/H2 transition) and the edge of
the observed CO and HCO+ emission. This implies that the H/H2 and C+/C/CO
transition zones are very close. These observations reveal a fragmented ridge
of high-density substructures, photoablative gas flows and instabilities at the
molecular cloud surface. The results suggest that the cloud edge has been
compressed by a high-pressure wave that currently moves into the molecular
cloud. The images demonstrate that dynamical and nonequilibrium effects are
important for the cloud evolution.


title:
Computationally Efficient Bayesian Estimation of High Dimensional
  Copulas with Discrete and Mixed Margins

abstract:
  Estimating copulas with discrete marginal distributions is challenging,
especially in high dimensions, because computing the likelihood contribution of
each observation requires evaluating $2^{J}$ terms, with $J$ the number of
discrete variables. Currently, data augmentation methods are used to carry out
inference for discrete copula and, in practice, the computation becomes
infeasible when $J$ is large. Our article proposes two new fast Bayesian
approaches for estimating high dimensional copulas with discrete margins, or a
combination of discrete and continuous margins. Both methods are based on
recent advances in Bayesian methodology that work with an unbiased estimate of
the likelihood rather than the likelihood itself, and our key observation is
that we can estimate the likelihood of a discrete copula unbiasedly with much
less computation than evaluating the likelihood exactly or with current
simulation methods that are based on augmenting the model with latent
variables. The first approach builds on the pseudo marginal method that allows
Markov chain Monte Carlo simulation from the posterior distribution using only
an unbiased estimate of the likelihood. The second approach is based on a
Variational Bayes approximation to the posterior and also uses an unbiased
estimate of the likelihood. We show that Monte Carlo and randomised quasi Monte
Carlo methods can be used with both approaches to reduce the variability of the
estimate of the likelihood, and hence enable us to carry out Bayesian inference
for high values of $J$ for some classes of copulas where the computation was
previously too expensive. Our article also introduces {\em a correlated quasi
random number pseudo marginal} approach into the literature. The methodology is
illustrated through several real and simulated data examples.


title: Effectiveness of greedily collecting items in open world games

abstract:
  Since Pokemon Go sent millions on the quest of collecting virtual monsters,
an important question has been on the minds of many people: Is going after the
closest item first a time-and-cost-effective way to play? Here, we show that
this is in fact a good strategy which performs on average only 7% worse than
the best possible solution in terms of the total distance traveled to gather
all the items. Even when accounting for errors due to the inability of people
to accurately measure distances by eye, the performance only goes down to 16%
of the optimal solution.


title: Invariants de Hasse $\mu$-ordinaires

abstract:
  In this article, we construct in a purely local way partial (Hasse)
invariants for $p$-divisible groups with given endomorphisms, using crystalline
cohomology. Theses invariants generalises the classical Hasse invariant, and
allow us to study families of such groups. We also study a few geometric
properties of theses invariants. Used in the context of Shimura varieties, for
example, theses invariants are detecting some Newton strata, including the
$\mu$-ordinary locus.


title:
Study of Distortions in Statistics of Counts in CCD Observations using
  the Fano Factor

abstract:
  Factors distorting the statistics of photocounts when acquiring objects with
low fluxes were considered here. Measurements of the Fano factor for existing
CCD systems were conducted. The study allows one to conclude on the quality of
the CCD video signal processing channel. The optimal strategy for faint object
observations was suggested.


title:
Phase transition and Gibbs Measures of Vannimenus model on semi-infinite
  Cayley tree of order three

abstract:
  Ising model with competing nearest-neighbors and prolonged
next-nearest-neighbors interactions on a Cayley tree has long been studied but
there are still many problems untouched. This paper tackles new Gibbs measures
of Ising-Vannimenus model with competing nearest-neighbors and prolonged
next-nearest-neighbors interactions on a Cayley tree (or Bethe lattice) of
order three. By using a new approach, we describe the translation-invariant
Gibbs measures for the model. We show that some of the measures are extreme
Gibbs distributions. In this paper we take up with trying to determine when
phase transition does occur.


title:
Thermally induced magnonic spin current, thermomagnonic torques and
  domain wall dynamics in the presence of Dzyaloshinskii-Moriya interaction

abstract:
  Thermally activated domain wall (DW) motion in magnetic insulators has been
considered theoretically, with a particular focus on the role of
Dzyaloshinskii-Moriya Interaction (DMI) and thermomagnonic torques. The
thermally assisted DW motion is a consequence of the magnonic spin current due
to the applied thermal bias. In addition to the exchange magnonic spin current
and the exchange adiabatic and the entropic spin transfer torques, we also
consider the DMI-induced magnonic spin current, thermomagnonic DMI field-like
torque and the DMI entropic torque. Analytical estimations are supported by
numerical calculations. We found that the DMI has a substantial influence on
the size and the geometry of DWs, and that the DWs become oriented parallel to
the long axis of the nanostrip. Increasing the temperature smoothes the DWs.
Moreover, the thermallyinduced magnonic current generates a torque on the DWs,
which is responsible for their motion. From our analysis it follows that for a
large enough DMI the influence of DMI-induced field-like torque is much
stronger than that of the DMI and the exchange entropic torques. By
manipulating the strength of the DMI constant, one can control the speed of the
DW motion, and the direction of the DW motion can be switched, as well. We also
found that DMI not only contributes to the total magnonic current, but also it
modifies the exchange magnonic spin current, and this modification depends on
the orientation of the steady state magnetization. The observed phenomenon can
be utilized in spin caloritronics devices, for example in the DMI based thermal
diodes. By switching the magnetization direction, one can rectify the total
magnonic spin current.


title:
Commensurate $4a_0$ period Charge Density Modulations throughout the
  $Bi_2Sr_2CaCu_2O_{8+x}$ Pseudogap Regime

abstract:
  Theories based upon strong real space (r-space) electron electron
interactions have long predicted that unidirectional charge density modulations
(CDM) with four unit cell (4$a_0$) periodicity should occur in the hole doped
cuprate Mott insulator (MI). Experimentally, however, increasing the hole
density p is reported to cause the conventionally defined wavevector $Q_A$ of
the CDM to evolve continuously as if driven primarily by momentum space
(k-space) effects. Here we introduce phase resolved electronic structure
visualization for determination of the cuprate CDM wavevector. Remarkably, this
new technique reveals a virtually doping independent locking of the local CDM
wavevector at $|Q_0|=2\pi/4a_0$ throughout the underdoped phase diagram of the
canonical cuprate $Bi_2Sr_2CaCu_2O_8$. These observations have significant
fundamental consequences because they are orthogonal to a k-space (Fermi
surface) based picture of the cuprate CDM but are consistent with strong
coupling r-space based theories. Our findings imply that it is the latter that
provide the intrinsic organizational principle for the cuprate CDM state.


title:
Differences of weighted differentiation composition operators from
  Bloch-type space to weighted-type space

abstract:
  We found several new equivalent characterizations for the boundedness and
compactness of the differences of weighted differentiation composition
operators from Bloch-type space to weighted-type space. Especially, we
estimated its essential norm in terms of the $n$-th power of the induced
analytic self-maps on the unit disk.


title: Numerical approaches for some Nonlinear Eigenvalue Problems

abstract:
  In this article we are interested for the numerical study of nonlinear
eigenvalue problems. We begin with a review of theoretical results obtained by
functional analysis methods, especially for the Schrodinger pencils. Some
recall are given for the pseudospectra. Then we present the numerical methods
and results obtained for eigenvalues computation with spectral methods and
finite difference discretization, in infinite or bounded domains. Comparison
with theoretical results is done. The main difficulty here is that we have to
compute eigenvalues of strongly non-self-adjoint operators which are very
unstable.


title:
Modeling Cellular Networks with Full Duplex D2D Communication: A
  Stochastic Geometry Approach

abstract:
  Full-duplex (FD) communication is optimistically promoted to double the
spectral efficiency if sufficient self-interference cancellation (SIC) is
achieved. However, this is not true when deploying FD-communication in a
large-scale setup due to the induced mutual interference. Therefore, a
large-scale study is necessary to draw legitimate conclusions about gains
associated with FD-communication. This paper studies the FD operation for
underlay device-to-device (D2D) communication sharing the uplink resources in
cellular networks. We propose a disjoint fine-tuned selection criterion for the
D2D and FD modes of operation. Then, we develop a tractable analytical
paradigm, based on stochastic geometry, to calculate the outage probability and
rate for cellular and D2D users. The results reveal that even in the case of
perfect SIC, due to the increased interference injected to the network by
FD-D2D communication, having all proximity UEs transmit in FD-D2D is not
beneficial for the network. However, if the system parameters are carefully
tuned, non-trivial network spectral-efficiency gains (64 shown) can be
harvested. We also investigate the effects of imperfect SIC and D2D-link
distance distribution on the harvested FD gains.


title: Relative K-stability and Extremal Sasaki metrics

abstract:
  We define K-stability of a polarized Sasakian manifold relative to a maximal
torus of automorphisms. The existence of a Sasaki-extremal metric in the
polarization is shown to imply that the polarization is K-semistable. Computing
this invariant for the deformation to the normal cone gives an extention of the
Lichnerowicz obstruction, due to Gauntlett, Martelli, Sparks, and Yau, to an
obstruction of Sasaki-extremal metrics. We use this to give a list of examples
of Sasakian manifolds whose Sasaki cone contains no extremal representatives.
These give the first examples of Sasaki cones of dimension greater than one
that contain no extremal Sasaki metrics whatsoever. In the process we compute
the unreduced Sasaki cone for an arbitrary smooth link of a weighted
homogeneous polynomial.


title:
An alternative representation of the Vi\`ete's formula for pi by
  Chebyshev polynomials of the first kind

abstract:
  There are several reformulations of the Vi\`ete's formula for pi that have
been reported in the modern literature. In this paper we show another analog to
the Vi\`ete's formula for pi by Chebyshev polynomials of the first kind.


title:
Schr\"odinger Equation with a Non-Central Potential: Some Statistical
  Quantities

abstract:
  In this paper, we search the dependence of some statistical quantities such
as the free energy, the mean energy, the entropy, and the specific heat for the
Schr\"odinger equation on the temperature, particularly the case of a
non-central potential. The basic point is to find the partition function which
is obtained by a method based on the Euler-Maclaurin formula. At first, we
present the analytical results by supporting with some plots for the thermal
functions for one- and three-dimensional cases to find out the effect of the
angular momentum. We also search then the effect of the angle-dependent part of
the non-central potential. We discuss the results briefly for a phase
transition for the system. We also present our results for three-dimesional
harmonic oscillator.


title:
Approximate Universal Relations among Tidal Parameters for Neutron Star
  Binaries

abstract:
  One of largest uncertainties in nuclear physics is the relation between the
pressure and density of supranuclear matter: the equation of state. Some of
this uncertainty may be removed through future gravitational wave observations
of neutron star binaries by extracting the tidal deformabilities (or Love
numbers) of neutron stars. Previous studies showed that only a certain
combination of the individual deformabilities of each body (chirp tidal
deformability) can be measured with second-generation gravitational wave
interferometers, such as Adv. LIGO, due to correlations between the individual
deformabilities. To overcome this, we search for approximately universal (or
equation-of-state independent) relations between two combinations of the
individual tidal deformabilities, such that once one of them has been measured,
the other can be automatically obtained and the individual ones decoupled
through these relations. We find an approximately universal relation between
the symmetric and the anti-symmetric combination of the individual tidal
deformabilities that is equation-of-state-insensitive to $20\%$ for binaries
with masses less than $1.7M_\odot$. We show that these relations can be used to
eliminate a combination of the tidal parameters from the list of model
parameters, thus breaking degeneracies and improving the accuracy in parameter
estimation. A simple study shows that the universal relations can improve the
accuracy in the extraction of the symmetric combination of tidal parameters by
as much as an order of magnitude, making the overall accuracy in the extraction
of this parameter slightly better than that of the chirp tidal deformability.
These new universal relations and the improved measurement accuracy on tidal
parameters not only are important to astrophysics and nuclear physics, but also
impact our ability to probe extreme gravity with gravitational waves and
cosmology.


title:
Linking particle properties to paste extrusion flow characteristics
  using discrete element simulations

abstract:
  Extrusion is a widely used process for forming pastes into designed shapes,
and is central to the manufacture of many industrial products. The extrusion
through a square-entry die of a model paste of non-Brownian spheres suspended
in a Newtonian fluid is investigated using discrete element simulations,
capturing individual particle contacts and hydrodynamic interactions. The
simulations reveal inhomogeneous velocity and stress distributions, originating
in the inherent microstructure formed by the constituent particles. Such
features are shown to be relevant to generic paste extrusion behaviour, such as
die swell. The pressure drop across the extruder is correlated with the
extrudate velocity using the Benbow-Bridgwater equation, with the empirical
parameters being linked directly to particle properties such as surface
friction, and processing conditions such as extruder wall roughness. Our model
and results bring recent advances in suspension rheology into an industrial
setting, laying foundations for future model development, paste formulation and
extrusion design.