title: The Born-Infeld/Gravity Correspondence

abstract:
  In this paper we explore the correspondence between four-dimensional
Born-Infeld theory and five-dimensional classical gravity. The Born-Infeld
theory side corresponds to the low energy effective theory for open strings
ending on coincident D3-branes in a (slowly varying) background Kalb-Ramond
field, including all higher-derivative corrections. On the gravity side one has
the gravitational (closed string) description of D3-branes in the same
background Kalb-Ramond field and the correspondence is thus a consequence of
the open/closed string duality. According to the correspondence the gravity
side provides a description of the strong coupling limit of Born-Infeld theory.
This is a correspondence between effective theories in a similar sense as in
the fluid/gravity correspondence. We match the Born-Infeld and gravity sides up
to, and including, two-derivative corrections. To this end, we find a new
gravity solution for D3-branes with flat embedding in the background of an
arbitrary constant background Kalb-Ramond field and show that there are no
two-derivative corrections to this for a slowly varying Kalb-Ramond field.


title:
Orientations of Simplices Determined by Orderings on the Coordinates of
  their Vertices

abstract:
  Provided n points in an (n-1)-dimensional affine space, and one ordering of
the points for each coordinate, we address the problem of testing whether these
orderings determine if the points are the vertices of a simplex (i.e. are
affinely independent), regardless of the real values of the coordinates. We
also attempt to determine the orientation of this simplex. In other words,
given a matrix whose columns correspond to affine points, we want to know when
the sign (or the non-nullity) of its determinant is implied by orderings given
to each row for the values of the row. We completely solve the problem in
dimensions 2 and 3. We provide a direct combinatorial characterization, along
with a formal calculus method. It can also be viewed as a decision algorithm,
and is based on testing the existence of a suitable inductive cofactor
expansion of the determinant. We conjecture that our method generalizes in
higher dimensions. This work aims to be part of a study on how oriented
matroids encode shapes of 3-dimensional landmark-based objects. Specifically,
applications include the analysis of anatomical data for physical anthropology
and clinical research.


title: Sufficient conditions for memory kernel master equation

abstract:
  We derive sufficient conditions for the memory kernel which guarantee
legitimate (completely positive and trace-preserving) dynamical map. It turns
out that these conditions provide a natural parameterizations of the dynamical
map being a generalization of Markovian semigroup. It is shown that this class
of maps cover almost all known examples -- from Markovian semigroup,
semi-Markov evolution up to collision models and their generalization.


title:
MUSE crowded field 3D spectroscopy of over 12,000 stars in the globular
  cluster NGC 6397 - II. Probing the internal dynamics and the presence of a
  central black hole

abstract:
  We present a detailed analysis of the kinematics of the Galactic globular
cluster NGC 6397 based on more than ~18,000 spectra obtained with the novel
integral field spectrograph MUSE. While NGC 6397 is often considered a core
collapse cluster, our analysis suggests a flattening of the surface brightness
profile at the smallest radii. Although it is among the nearest globular
clusters, the low velocity dispersion of NGC 6397 of <5km/s imposes heavy
demands on the quality of the kinematical data. We show that despite its
limited spectral resolution, MUSE reaches an accuracy of 1km/s in the analysis
of stellar spectra. We find slight evidence for a rotational component in the
cluster and the velocity dispersion profile that we obtain shows a mild central
cusp. To investigate the nature of this feature, we calculate spherical Jeans
models and compare these models to our kinematical data. This comparison shows
that if a constant mass-to-light ratio is assumed, the addition of an
intermediate-mass black hole with a mass of 600M_sun brings the model
predictions into agreement with our data, and therefore could be at the origin
of the velocity dispersion profile. We further investigate cases with varying
mass-to-light ratios and find that a compact dark stellar component can also
explain our observations. However, such a component would closely resemble the
black hole from the constant mass-to-light ratio models as this component must
be confined to the central ~5arcsec of the cluster and must have a similar
mass. Independent constraints on the distribution of stellar remnants in the
cluster or kinematic measurements at the highest possible spatial resolution
should be able to distinguish the two alternatives.


title: A semi-automatic computer-aided method for surgical template design

abstract:
  This paper presents a generalized integrated framework of semi-automatic
surgical template design. Several algorithms were implemented including the
mesh segmentation, offset surface generation, collision detection, ruled
surface generation, etc., and a special software named TemDesigner was
developed. With a simple user interface, a customized template can be semi-
automatically designed according to the preoperative plan. Firstly, mesh
segmentation with signed scalar of vertex is utilized to partition the inner
surface from the input surface mesh based on the indicated point loop. Then,
the offset surface of the inner surface is obtained through contouring the
distance field of the inner surface, and segmented to generate the outer
surface. Ruled surface is employed to connect inner and outer surfaces.
Finally, drilling tubes are generated according to the preoperative plan
through collision detection and merging. It has been applied to the template
design for various kinds of surgeries, including oral implantology, cervical
pedicle screw insertion, iliosacral screw insertion and osteotomy,
demonstrating the efficiency, functionality and generality of our method.


title: Speed of Sound in Hadronic matter using Non-extensive Tsallis Statistics

abstract:
  The speed of sound ($c_s$) is studied to understand the hydrodynamical
evolution of the matter created in heavy-ion collisions. The quark-gluon plasma
(QGP) formed in heavy-ion collisions evolves from an initial QGP to the
hadronic phase via a possible mixed phase. Due to the system expansion in a
first order phase transition scenario, the speed of sound reduces to zero as
the specific heat diverges. We study the speed of sound for systems, which
deviate from a thermalized Boltzmann distribution using non-extensive Tsallis
statistics. In the present work, we calculate the speed of sound as a function
of temperature for different $q$-values for a hadron resonance gas. We observe
a similar mass cut-off behaviour in non-extensive case for $c^{2}_s$ by
including heavier particles, as is observed in the case of a hadron resonance
gas following equilibrium statistics. Also, we explicitly present that the
temperature where the mass cut-off starts, varies with the $q$-parameter which
hints at a relation between the degree of non-equilibrium and the limiting
temperature of the system. It is shown that for values of $q$ above
approximately 1.13 all criticality disappear in the speed of sound, i.e. the
decrease in the value of the speed of sound, observed at lower values of $q$,
disappears completely.


title:
Modeling the Landau-Gauge Ghost Propagator in 2, 3 and 4 Space-Time
  Dimensions

abstract:
  We present an analytic description of numerical results for the ghost
propagator G(p^2) in minimal Landau gauge on the lattice. The data were
produced in the SU(2) case using the largest lattice volumes to date, for d =
2, 3 and 4 space-time dimensions. Our proposed form for G(p^2) is derived from
the one-loop relation between ghost and gluon propagators, considering a
tree-level ghost-gluon vertex and our previously obtained gluon-propagator
results \cite{Cucchieri:2011ig}. Although this one-loop expression is not a
good description of the data, it leads to a one-parameter fit of our
ghost-propagator data with a generally good value of \chi^2/dof, comparable to
other fitting forms used in the literature. At the same time, we present a
simple parametrization of the difference between the lattice data and the
one-loop predictions.


title:
Non-uniform force allocation for area preservation in spring network
  models

abstract:
  In modelling of elastic objects in a flow such as red blood cells, white
blood cells, or tumour cells, several elastic moduli are involved. One of them
is the area conservation modulus. In this paper, we focus on spring network
models and we introduce a new way of modeling the area preservation modulus. We
take into account the current shape of the individual triangles and find the
proportional allocation of area conservation forces, which would for individual
triangles preserve their shapes. The analysis shows that this approach tends to
regularize the triangulation. We demonstrate this effect on individual
triangles as well as on the complete triangulations.


title: Uniformity Properties of Construction C

abstract:
  Construction C (also known as Forney's multi-level code formula) forms a
Euclidean code for the additive white Gaussian noise (AWGN) channel from $L$
binary code components. If the component codes are linear, then the minimum
distance is the same for all the points, although the kissing number may vary.
In fact, while in the single level ($L=1$) case it reduces to lattice
Construction A, a multi-level Construction C is in general not a lattice. We
show that the two-level ($L=2$) case is special: a two-level Construction C
satisfies Forney's definition for a geometrically uniform constellation.
Specifically, every point sees the same configuration of neighbors, up to a
reflection of the coordinates in which the lower level code is equal to 1. In
contrast, for three levels and up ($L\geq 3$), we construct examples where the
distance spectrum varies between the points, hence the constellation is not
geometrically uniform.


title:
MUSE crowded field 3D spectroscopy of over 12,000 stars in the globular
  cluster NGC 6397 - I. The first comprehensive spectroscopic HRD of a globular
  cluster

abstract:
  Aims. We demonstrate the high multiplex advantage of crowded field 3D
spectroscopy using the new integral field spectrograph MUSE by means of a
spectroscopic analysis of more than 12,000 individual stars in the globular
cluster NGC 6397. Methods. The stars are deblended with a PSF fitting
technique, using a photometric reference catalogue from HST as prior, including
relative positions and brightnesses. This catalogue is also used for a first
analysis of the extracted spectra, followed by an automatic in-depth analysis
using a full-spectrum fitting method based on a large grid of PHOENIX spectra.
Results. With 18,932 spectra from 12,307 stars in NGC 6397 we have analysed the
largest sample so far available for a single globular cluster. We derived a
mean radial velocity of vrad=17.84+-0.07 km/s and a mean metallicity of
[Fe/H]=-2.120+-0.002, with the latter seemingly varying with temperature for
stars on the RGB. We determine T_eff and [Fe/H] from the spectra, and log g
from HST photometry. This is the first very comprehensive HRD for a globular
cluster based on the analysis of several thousands of stellar spectra, ranging
from the main sequence to the tip of the RGB. Furthermore, two interesting
objects were identified with one being a post-AGB star and the other a possible
millisecond-pulsar companion.


title: Bayesian Nonparametric System Reliability using Sets of Priors

abstract:
  An imprecise Bayesian nonparametric approach to system reliability with
multiple types of components is developed. This allows modelling partial or
imperfect prior knowledge on component failure distributions in a flexible way
through bounds on the functioning probability. Given component level test data
these bounds are propagated to bounds on the posterior predictive distribution
for the functioning probability of a new system containing components
exchangeable with those used in testing. The method further enables
identification of prior-data conflict at the system level based on component
level test data. New results on first-order stochastic dominance for the
Beta-Binomial distribution make the technique computationally tractable. Our
methodological contributions can be immediately used in applications by
reliability practitioners as we provide easy to use software tools.


title: Localized plasmons in bilayer graphene nanodisks

abstract:
  We study localized plasmonic excitations in bilayer graphene (BLG) nanodisks,
comparing AA-stacked and AB-stacked BLG and contrasting the results to the case
of two monolayers without electronic hybridization. The electrodynamic response
of the BLG electron gas is described in terms of a spatially homogeneous
surface conductivity, and an efficient alternative two-dimensional
electrostatic approach is employed to carry out all the numerical calculations
of plasmon resonances. Due to a unique electronic band structures, the
resonance frequency of the traditional dipolar plasmonic mode in the AA-stacked
BLG nanodisk is roughly doping independent in the low-doping regime, while the
mode is highly damped as the Fermi level approaches the interlayer hopping
energy $\gamma$ associated with tunneling of electrons between the two layers.
In addition to the traditional dipolar mode, we find that the AB-stacked BLG
nanodisk also hosts a new plasmonic mode with energy larger than $\gamma$. This
mode can be tuned by either the doping level or structural size, and
furthermore, this mode can dominate the plasmonic response for realistic
structural conditions.


title:
Dynamics of Disagreement: Large-Scale Temporal Network Analysis Reveals
  Negative Interactions in Online Collaboration

abstract:
  Disagreement and conflict are a fact of social life and considerably affect
our well-being and productivity. Such negative interactions are rarely
explicitly declared and recorded and this makes them hard for scientists to
study. We overcome this challenge by investigating the patterns in the timing
and configuration of contributions to a large online collaboration community.
We analyze sequences of reverts of contributions to Wikipedia, the largest
online encyclopedia, and investigate how often and how fast they occur compared
to a null model that randomizes the order of actions to remove any systematic
clustering. We find evidence that individuals systematically attack the same
person and attack back their attacker; both of these interactions occur at a
faster response rate than expected. We also establish that individuals come to
defend an attack victim but we do not find evidence that attack victims "pay it
forward" or that attackers collude to attack the same individual. We further
find that high-status contributors are more likely to attack many others
serially, status equals are more likely to revenge attacks back, while attacks
by lower-status contributors trigger attacks forward; yet, it is the
lower-status contributors who also come forward to defend third parties. The
method we use can be applied to other large-scale temporal communication and
collaboration networks to identify the existence of negative social
interactions and other social processes.


title: Spin-orbit coupling measurement by the scanning gate microscopy

abstract:
  We propose a procedure for extraction of the Fermi surface for a
two-dimensional electron gas with a strong Rashba spin-orbit coupling from
conductance microscopy. Due to the interplay between the effective spin-orbit
magnetic field and the external one within the plane of confinement, the
backscattering induced by a charged tip of an atomic force microscope located
above the sample, leads to the spin precession, and thus to the spin mixing of
the incident and reflected modes. This mixing leads to a characteristic
angle-dependent beating pattern visible in the conductance maps. We show that
the structure of the Fermi level, bearing signatures of the spin-orbit
coupling, can be extracted from the Fourier transform of the interference
fringes in the conductance maps as a function of the magnetic field direction.
We propose a simple analytical model which can be used to fit the experimental
data in order to obtain the spin-orbit coupling constant.


title:
Novel Analysis of the Multiwavelength Structure of Relativistic Jet in
  Quasar 3C 273

abstract:
  We present a detailed analysis of the best-quality multi-wavelength data
gathered for the large-scale jet in the core-dominated quasar 3C 273. We
analyze all the archival observations of the target with the Chandra X-ray
Observatory, the far-ultraviolet observations with the Hubble Space Telescope,
and the 8.4 GHz map obtained with the Very Large Array. In our study we focus
on investigating the morphology of the outflow at different frequencies, and
therefore we apply various techniques for the image deconvolution, paying
particular attention to a precise modeling of the Chandra and Hubble point
spread functions. We find that the prominent brightness enhancements in the
X-ray and far-ultraviolet jet of 3C 273 - the "knots" - are not point-like, and
can be resolved transversely as extended features with sizes of about $\simeq
0.5$ kpc. Also, the radio outflow is wider than the deconvolved
X-ray/ultraviolet jet. We have also found circumstantial evidence that the
intensity peaks of the X-ray knots are located systematically upstream of the
corresponding radio intensity peaks, with the projected spatial offsets along
the jet ranging from $\lesssim 0.2$ kpc up to $\simeq 1$ kpc. We discuss our
findings in the wider context of multi-component models for the emission and
structure of large-scale quasar jets, and speculate on the physical processes
enabling an efficient acceleration of the emitting ultra-relativistic electrons
along the entire jet length that exceeds 100 kpc.


title:
Linear and Nonlinear Mesoscopic Thermoelectric Transport with Coupling
  to Heat Baths

abstract:
  Decades of research on thermoelectrics stimulated by the fact that nano- and
meso-scale thermoelectric transport could yield higher energy conversion
efficiency and output power has recently uncovered a new direction on inelastic
thermoelectric effects. We introduce the history, motivation, and perspectives
on mesoscopic inelastic thermoelectric effects.


title: Expansions from frame coefficients with erasures

abstract:
  We propose a new approach to the problem of recovering signal from frame
coefficients with erasures. Such problems arise naturally from applications
where some of the coefficients could be corrupted or erased during the data
transmission. Provided that the erasure set satisfies the minimal redundancy
condition, we construct a suitable synthesizing dual frame which enables us to
perfectly reconstruct the original signal without recovering the lost
coefficients. Such dual frames which compensate for erasures are described from
various viewpoints.
  In the second part of the paper frames robust with respect to finitely many
erasures are investigated. We characterize all full spark frames for
finite-dimensional Hilbert spaces. In particular, we show that each full spark
frames is generated by a matrix whose all square submatrices are nonsingular.
In addition, we provide a method for constructing totally positive matrices.
Finally, we give a method, applicable to a large class of frames, for
transforming general frames into Parseval ones.


title: Explosive Crump-Mode-Jagers branching processes

abstract:
  In this paper we initiate the theory of Crump-Mode-Jagers branching processes
(BP) in the setting where no Malthusian parameter exist, i.e., the process
grows faster than exponential. A Crump-Mode-Jagers BP is a branching process
(in continuous time) where arbitrary dependencies are allowed between the
birth-times of the children of a single individual in the population. It is
however assumed that these reproduction processes are i.i.d. point processes
for different individuals. This paper focuses on determining whether this
branching process explodes, that is, the process reaches infinitely many
individuals in finite time. We develop comparison techniques between
reproduction processes. We study special cases in terms of explosivity such as
age-dependent BPs, and epidemic models with contagious intervals. For this, we
superimpose a random contagious interval $[I, C]$ on every individual in the BP
and keep only the children with birth-times that fall in this interval of the
parent. We show that the distribution of the end $C$ of the contagious interval
does not matter in terms of explosion, while the distribution of $I$ does: the
epidemic explodes if and only if the two age-dependent BPs with the original
birth-times and birth-times $I$ explode. We finish studying some pathological
examples such as birth-time distributions that are singular to the
Lebesque-measure yet they produce an explosive BP with arbitrary power-law
offspring distributions.


title:
Efficient implementation of the Localized Orthogonal Decomposition
  method

abstract:
  In this paper we present algorithms for an efficient implementation of the
Localized Orthogonal Decomposition method (LOD). The LOD is a multiscale method
for the numerical simulation of partial differential equations with a continuum
of inseparable scales. We show how the method can be implemented in a fairly
standard Finite Element framework and discuss its realization for different
types of problems, such as linear elliptic problems with rough coefficients and
linear eigenvalue problems.


title: Accelerating Local Search for the Maximum Independent Set Problem

abstract:
  Computing high-quality independent sets quickly is an important problem in
combinatorial optimization. Several recent algorithms have shown that
kernelization techniques can be used to find exact maximum independent sets in
medium-sized sparse graphs, as well as high-quality independent sets in huge
sparse graphs that are intractable for exact (exponential-time) algorithms.
However, a major drawback of these algorithms is that they require significant
preprocessing overhead, and therefore cannot be used to find a high-quality
independent set quickly.
  In this paper, we show that performing simple kernelization techniques in an
online fashion significantly boosts the performance of local search, and is
much faster than pre-computing a kernel using advanced techniques. In addition,
we show that cutting high-degree vertices can boost local search performance
even further, especially on huge (sparse) complex networks. Our experiments
show that we can drastically speed up the computation of large independent sets
compared to other state-of-the-art algorithms, while also producing results
that are very close to the best known solutions.


title:
Solve the linear quaternion-valued differential equations having
  multiple eigenvalues

abstract:
  The theory of two-dimensional linear quaternion-valued differential equations
(QDEs) was recently established (see Kou and Xia, SAPM). Some profound
differences between QDEs and ODEs were observed.
  Also, an algorithm to evaluate the fundamental matrix by employing the
eigenvalues and eigenvectors was presented in [Kou and Xia, SAPM]. However, the
fundamental matrix can be constructed providing that the eigenvalues are
simple. If the linear system has multiple eigenvalues, how to construct the
fundamental matrix? In particular, if the number of independent eigenvectors
might be less than the dimension of the system. That is, the numbers of the
eigenvectors is not enough to construct a fundamental matrix. How to find the
"missing solutions"? The main purpose of this paper is to answer this question.
Furthermore, Caley determinant for Quaternion-valued matrix was adopted to
proceed the theory of QDEs in [Kou and Xia, SAPM]. One big disadvantage of
Caley determinant is that it can be expanded along the different rows and
columns. This may lead to different results due to non-commutativity of the
quaternions. This approach is not convenient to be used. The novel definition
of determinant for Quaternion-valued matrix based on permutation is introduced
to analyze the theory. This newly definition of determinant has great advantage
compare to Calay determinant.


title: On finite groups with automorphisms whose fixed points are Engel

abstract:
  The main result of the paper is the following theorem. Let $q$ be a prime,
$n$ a positive integer and $A$ an elementary abelian group of order $q^2$.
Suppose that $A$ acts coprimely on a finite group $G$ and assume that for each
$a\in A^{\#}$ every element of $C_{G}(a)$ is $n$-Engel in $G$. Then the group
$G$ is $k$-Engel for some $\{n,q\}$-bounded number $k$.


title:
Investigation of the unidirectional spin heat conveyer effect in a 200nm
  thin Yttrium Iron Garnet film

abstract:
  We have investigated the unidirectional spin wave heat conveyer effect in
sub-micron thick yttrium iron garnet (YIG) films using lock-in thermography
(LIT). Although the effect is small in thin layers this technique allows us to
observe asymmetric heat transport by magnons which leads to asymmetric
temperature profiles differing by several mK on both sides of the exciting
antenna, respectively. Comparison of Damon-Eshbach and backward volume modes
shows that the unidirectional heat flow is indeed due to non-reciprocal
spin-waves. Because of the finite linewidth, small asymmetries can still be
observed when only the uniform mode of ferromagnetic resonance is excited. The
latter is of extreme importance for example when measuring the inverse
spin-Hall effect because the temperature differences can result in
thermovoltages at the contacts. Because of the non-reciprocity these
thermovoltages reverse their sign with a reversal of the magnetic field which
is typically deemed the signature of the inverse spin-Hall voltage.


title:
Ambipolar Light-Emitting Transistors on Chemical Vapor Deposited
  Monolayer MoS2

abstract:
  We realize and investigate ionic liquid gated field-effect transistors (FETs)
on large-area MoS2 monolayers grown by chemical vapor deposition (CVD). Under
electron accumulation, the performance of these devices is comparable to that
of FETs based on exfoliated flakes. FETs on CVD-grown material, however,
exhibit clear ambipolar transport, which for MoS2 monolayers had not been
reported previously. We exploit this property to estimate the bandgap {\Delta}
of monolayer MoS2 directly from the device transfer curves and find {\Delta}
$\approx$ 2.4-2.7 eV. In the ambipolar injection regime, we observe
electroluminescence due to exciton recombination in MoS2, originating from the
region close to the hole-injecting contact. Both the observed transport
properties and the behavior of the electroluminescence can be consistently
understood as due to the presence of defect states at an energy of 250-300 meV
above the top of the valence band, acting as deep traps for holes. Our results
are of technological relevance, as they show that devices with useful
optoelectronic functionality can be realized on large-area MoS2 monolayers
produced by controllable and scalable techniques.


title:
The Moon Zoo citizen science project: Preliminary results for the Apollo
  17 landing site

abstract:
  Moon Zoo is a citizen science project that utilises internet crowd-sourcing
techniques. Moon Zoo users are asked to review high spatial resolution images
from the Lunar Reconnaissance Orbiter Camera (LROC), onboard NASAs LRO
spacecraft, and perform characterisation such as measuring impact crater sizes
and identify morphological features of interest. The tasks are designed to
address issues in lunar science and to aid future exploration of the Moon. We
have tested various methodologies and parameters therein to interrogate and
reduce the Moon Zoo crater location and size dataset against a validated expert
survey. We chose the Apollo 17 region as a test area since it offers a broad
range of cratered terrains, including secondary-rich areas, older maria, and
uplands. The assessment involved parallel testing in three key areas: (1)
filtering of data to remove problematic mark-ups; (2) clustering methods of
multiple notations per crater; and (3) derivation of alternative crater
degradation indices, based on the statistical variability of multiple notations
and the smoothness of local image structures. We compared different
combinations of methods and parameters and assessed correlations between
resulting crater summaries and the expert census.
  We derived the optimal data reduction steps and settings of the existing Moon
Zoo crater data to agree with the expert census. Further, the regolith depth
and crater degradation states derived from the data are also found to be in
broad agreement with other estimates for the Apollo 17 region. Our study
supports the validity of this citizen science project but also recommends
improvements in key elements of the data acquisition planning and production.


title: Improved Query Topic Models via Pseudo-Relevant P\'olya Document Models

abstract:
  Query-expansion via pseudo-relevance feedback is a popular method of
overcoming the problem of vocabulary mismatch and of increasing average
retrieval effectiveness. In this paper, we develop a new method that estimates
a query topic model from a set of pseudo-relevant documents using a new
language modelling framework.
  We assume that documents are generated via a mixture of multivariate Polya
distributions, and we show that by identifying the topical terms in each
document, we can appropriately select terms that are likely to belong to the
query topic model. The results of experiments on several TREC collections show
that the new approach compares favourably to current state-of-the-art expansion
methods.


title:
Entrainment dominates the interaction of microalgae with micron-sized
  objects

abstract:
  The incessant activity of swimming microorganisms has a direct physical
effect on surrounding microscopic objects, leading to enhanced diffusion far
beyond the level of Brownian motion with possible influences on the spatial
distribution of non-motile planktonic species and particulate drifters. Here we
study in detail the effect of eukaryotic flagellates, represented by the green
microalga Chlamydomonas reinhardtii, on microparticles. Macro- and micro-scopic
experiments reveal that microorganism-colloid interactions are dominated by
rare close encounters leading to large displacements through direct
entrainment. Simulations and theoretical modelling show that the ensuing
particle dynamics can be understood in terms of a simple jump-diffusion
process, combining standard diffusion with Poisson-distributed jumps. This
heterogeneous dynamics is likely to depend on generic features of the
near-field of swimming microorganisms with front-mounted flagella.

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


title: Thermal Charm and Charmonium Production in Quark Gluon Plasma

abstract:
  We study the effect of thermal charm production on charmonium regeneration in
high energy nuclear collisions. By solving the kinetic equations for charm
quark and charmonium distributions in Pb+Pb collisions, we calculate the global
and differential nuclear modification factors $R_{AA}(N_{part})$ and
$R{AA}(p_t)$ for $J/\Psi$s. Due to the thermal charm production in hot medium,
the charmonium production source changes from the initially created charm
quarks at SPS, RHIC and LHC to the thermally produced charm quarks at Future
Circular Collider (FCC), and the $J/\Psi$ suppression ($R_{AA}<1$) observed so
far will be replaced by a strong enhancement ($R_{AA}>1$) at FCC at low
transverse momentum.


title: Indication of the High Mass-Transfer Ratio in S-type Symbiotic Binaries

abstract:
  By modelling H$^0$ column densities in eclipsing S-type symbiotic stars EG
And and SY Mus, we derived the wind velocity profile and the corresponding
mass-loss rate from their giants. Our analysis revealed a strong enhancement of
the wind at the orbital plane.


title:
Probing spacetime around Sagittarius A* using modeled VLBI closure
  phases

abstract:
  The emission region and black hole shadow of Sagittarius A*, the supermassive
black hole at the Galactic Center, can be probed with millimeter Very Long
Baseline Interferometry. Our goal is to probe the geometry of the emitting
plasma around Sgr A* by using modeled mm-VLBI closure phase calculations at 1.3
mm and to constrain the observer's inclination angle and position angle of the
black hole spin axis. We have simulated images for three different models of
the emission of Sgr A*: an orbiting spot, a disk model, and a jet model. The
orbiting spot model was used as a test case scenario, while the disk and jet
models are physically driven scenarios based on standard three-dimensional
general relativistic magnetohydrodynamic simulations of hot accretion flows.
Our results are compared to currently available closure phase observational
limits. Our results indicate that more models with closer to edge-on viewing
angles are consistent with observational limits. In general, jet and disk
geometries can reproduce similar closure phases for different sets of viewing
and position angles. Consequently, the favored black hole spin orientation and
its magnitude are strongly model dependent. We find that both the jet and the
disk models can explain current VLBI limits. We conclude that new observations
at 1.3 mm and possibly at longer wavelengths including other triangles of VLBI
baselines are necessary to interpret Sgr A* emission and the putative black
hole spin parameters.


title: Ba2YIrO6: A cubic double perovskite material with Ir5+ ions

abstract:
  Materials with a 5d4 electronic configuration are generally considered to
have a nonmagnetic ground state (J=0). Interestingly, Sr2YIrO6 (Ir5+ having 5d4
electronic configuration) was recently reported to exhibit long-range magnetic
order at low temperature and the distorted IrO6 octahedra were discussed to
cause the magnetism in this material. Hence, a comparison of structurally
distorted Sr2YIrO6 with cubic Ba2YIrO6 may shed light on the source of
magnetism in such Ir5+ materials with 5d4 configuration. Besides, Ir5+
materials having 5d4 are also interesting in the context of recently predicted
excitonic types of magnetism. Here we report a single-crystal-based analysis of
the structural, magnetic, and thermodynamic properties of Ba2YIrO6. We observe
that in Ba2YIrO6 for temperatures down to 0.4 K, long-range magnetic order is
absent but at the same time correlated magnetic moments are present. We show
that these moments are absent in fully relativistic ab initio band-structure
calculations; hence, their origin is presently unclear.


title: Irreversible Markov chain Monte Carlo algorithm for self-avoiding walk

abstract:
  We formulate an irreversible Markov chain Monte Carlo algorithm for the
self-avoiding walk (SAW), which violates the detailed balance condition and
satisfies the balance condition. Its performance improves significantly
compared to that of the Berretti-Sokal algorithm, which is a variant of the
Metropolis-Hastings method. The gained efficiency increases with the spatial
dimension (D), from approximately $10$ times in 2D to approximately $40$ times
in 5D. We simulate the SAW on a 5D hypercubic lattice with periodic boundary
conditions, for a system with a linear size up to $L=128$, and confirm that as
for the 5D Ising model, the finite-size scaling of the SAW is governed by
renormalized exponents $\nu^*=2/d$ and $\gamma/\nu^*=d/2$. The critical point
is determined, which is approximately $8$ times more precise than the best
available estimate.


title:
The Generalised Isolation-With-Migration Model: a Maximum-Likelihood
  Implementation for Multilocus Data Sets

abstract:
  Statistical inference about the speciation process has often been based on
the isolation-with-migration (IM) model, especially when the research aim is to
learn about the presence or absence of gene flow during divergence. The
generalised IM model introduced in this paper extends both the standard
two-population IM model and the isolation-with-initial-migration (IIM) model,
and encompasses both these models as special cases. It can be described as a
two-population IM model in which migration rates and population sizes are
allowed to change at some point in the past. By developing a maximum-likelihood
implementation of this GIM model, we enable inference on both historical and
contemporary rates of gene flow between two closely related species. Our method
relies on the spectral decomposition of the coalescent generator matrix and is
applicable to data sets consisting of the numbers of nucleotide differences
between one pair of DNA sequences at each of a large number of independent
loci.


title:
The inverse problem of the calculus of variations and the stabilization
  of controlled Lagrangian systems

abstract:
  We apply methods of the so-called `inverse problem of the calculus of
variations' to the stabilization of an equilibrium of a class of
two-dimensional controlled mechanical systems. The class is general enough to
include, among others, the inverted pendulum on a cart and the inertia wheel
pendulum. By making use of a condition that follows from Douglas'
classification, we derive feedback controls for which the control system is
variational. We then use the energy of a suitable controlled Lagrangian to
provide a stability criterion for the equilibrium.


title: Universality in string interactions

abstract:
  In this letter, we provide evidence for universality in the low-energy
expansion of tree-level string interactions. More precisely, in the
alpha'-expansion of tree-level scattering amplitudes, we conjecture that the
leading transcendental coefficient at each order in alpha' is universal for all
perturbative string theories. We have checked this universality up to seven
points and trace its origin to the ability to restructure the disk integrals of
open bosonic string into those of the superstring. The accompanying kinematic
functions have the same low-energy limit and do not introduce any
transcendental numbers in their alpha'-corrections. Universality in the
closed-string sector then follows from the KLT-relations.


title:
Symplecticity-preserving continuous-stage Runge-Kutta-Nystr\"{o}m
  methods

abstract:
  We develop continuous-stage Runge-Kutta-Nystr\"{o}m (csRKN) methods for
solving second order ordinary differential equations (ODEs) in this paper. The
second order ODEs are commonly encountered in various fields and some of them
can be reduced to the first order ODEs with the form of separable Hamiltonian
systems. The symplecticity-preserving numerical algorithm is of interest for
solving such special systems. We present a sufficient condition for a csRKN
method to be symplecticity-preserving, and by using Legendre polynomial
expansion we show a simple way to construct such symplectic RKN type method.


title: A new insight into the V1184 Tau variability

abstract:
  V1184 Tau is a young variable for long time monitored at optical wavelengths.
Its variability has been ascribed to a sudden and repetitive increase of the
circumstellar extinction (UXor-type variable), but the physical origin of such
variation, although hypothesized, has not been fully supported on observational
basis. To get a new insight into the variability of V1184 Tau, we present new
photometric and spectroscopic observations taken in the period 2008-2015.
During these years the source has reached the same high brightness level that
had before the remarkable fading of about 5 mag undergone in 2004. The optical
spectrum is the first obtained when the continuum is at its maximum level. The
observations are interpreted in the framework of extinction driven variability.
We analyze light curves, optical and near-infrared colors, SED and optical
spectrum. The emerging picture indicates that the source fading is due to an
extinction increase of DeltaA_V about 5 mag, associated with a strong infrared
excess, attributable to a thermal component at T=1000 K. From the flux of
H(alpha) we derive a mass accretion rate between 10^-11 -5 10^-10 M_sun yr^-1
s, consistent with that of classical T Tauri stars of similar mass. The source
SED was fitted for both the high and low level of brightness. A scenario
consistent with the known stellar properties (such as spectral type, mass and
radius) is obtained only if the distance to the source is of few hundreds of
parsecs, in contrast with the commonly assumed value of 1.5 kpc. Our analysis
partially supports that presented by Grinin (2009), according to which the
circumstellar disk undergoes a periodical puffing, whose observational effects
are both to shield the central star and to evidence a disk wind activity.
However, since the mass accretion rate remains almost constant with time, the
source is likely not subject to accretion bursts.


title:
Coupling between Majorana fermions and Nambu-Goldstone bosons inside a
  non-Abelian vortex in dense QCD

abstract:
  Quark matter at high density may exhibit color superconductivity. As magnetic
flux tubes in metallic superconductors, color magnetic flux tubes as
non-Abelian vortices appear in the color-flavor locked phase of high density
QCD. ${\mathbb C}P^2$ Nambu-Goldstone bosons and Majorana fermions belonging to
the triplet representation are known to be localized around a non-Abelian
vortex. In this paper, we determine the coupling of these bosonic and fermionic
modes by using the nonlinear realization method.


title: Construction of the de Sitter supergravity

abstract:
  Recently, the complete action for an N=1 pure supergravity action in 4
dimensions that allows a positive, negative or zero cosmological constant has
been constructed. The action is the generalization of a Volkov-Akulov action
for the Goldstino coupled to supergravity. The construction uses a nilpotent
multiplet.
  This paper is written in honour of Philippe Spindel. AVP enjoyed
collaborations and many interactions with Philippe, who has always appreciated
very precise derivations. We use this occasion to give a very detailed account
of the calculations that lead to the published results. We review aspects of
supersymmetry with de Sitter backgrounds, the treatment of auxiliary fields,
and other ingredients in the construction.


title:
Boundary versus bulk behavior of time-dependent correlation functions in
  one-dimensional quantum systems

abstract:
  We study the influence of reflective boundaries on time-dependent responses
of one-dimensional quantum fluids at zero temperature beyond the low-energy
approximation. Our analysis is based on an extension of effective mobile
impurity models for nonlinear Luttinger liquids to the case of open boundary
conditions. For integrable models, we show that boundary autocorrelations
oscillate as a function of time with the same frequency as the corresponding
bulk autocorrelations. This frequency can be identified as the band edge of
elementary excitations. The amplitude of the oscillations decays as a power law
with distinct exponents at the boundary and in the bulk, but boundary and bulk
exponents are determined by the same coupling constant in the mobile impurity
model. For nonintegrable models, we argue that the power-law decay of the
oscillations is generic for autocorrelations in the bulk, but turns into an
exponential decay at the boundary. Moreover, there is in general a nonuniversal
shift of the boundary frequency in comparison with the band edge of bulk
excitations. The predictions of our effective field theory are compared with
numerical results obtained by time-dependent density matrix renormalization
group (tDMRG) for both integrable and nonintegrable critical spin-$S$ chains
with $S=1/2$, $1$ and $3/2$.


title:
Phonon Boltzmann equation-based discrete unified gas kinetic scheme for
  multiscale heat transfer

abstract:
  Numerical prediction of multiscale heat transfer is a challenging problem due
to the wide range of time and length scales involved. In this work a discrete
unified gas kinetic scheme (DUGKS) is developed for heat transfer in materials
with different acoustic thickness based on the phonon Boltzmann equation. With
discrete phonon direction, the Boltzmann equation is discretized with a
second-order finite-volume formulation, in which the time-step is fully
determined by the Courant-Friedrichs-Lewy (CFL) condition. The scheme has the
asymptotic preserving (AP) properties for both diffusive and ballistic regimes,
and can present accurate solutions in the whole transition regime as well. The
DUGKS is a self-adaptive multiscale method for the capturing of local transport
process. Numerical tests for both heat transfers with different Knudsen numbers
are presented to validate the current method.


title:
Magnetotransport in single layer graphene in a large parallel magnetic
  field

abstract:
  Graphene on hexagonal boron-nitride (h-BN) is an atomically flat conducting
system that is ideally suited for probing the effect of Zeeman splitting on
electron transport. We demonstrate by magneto-transport measurements that a
parallel magnetic field up to 30 Tesla does not affect the transport properties
of graphene on h-BN even at charge neutrality where such an effect is expected
to be maximal. The only magnetoresistance detected at low carrier
concentrations is shown to be associated with a small perpendicular component
of the field which cannot be fully eliminated in the experiment. Despite the
high mobility of charge carries at low temperatures, we argue that the effects
of Zeeman splitting are fully masked by electrostatic potential fluctuations at
charge neutrality.


title:
The non-linear coupled spin 2 - spin 3 Cotton equation in three
  dimensions

abstract:
  In the context of three-dimensional conformal higher spin theory we derive,
in the frame field formulation, the full non-linear spin 3 Cotton equation
coupled to spin 2. This is done by solving the corresponding Chern-Simons gauge
theory system of equations, that is, using $F=0$ to eliminate all auxiliary
fields and thus expressing the Cotton equation in terms of just the spin 3
frame field and spin 2 covariant derivatives and tensors (Schouten). In this
derivation we neglect the spin 4 and higher spin sectors and approximate the
star product commutator by a Poisson bracket. The resulting spin 3 Cotton
equation is complicated but can be related to linearized versions in the metric
formulation obtained previously by other authors. The expected symmetry (spin 3
"translation", "Lorentz" and "dilatation") properties are verified for Cotton
and other relevant tensors but some perhaps unexpected features emerge in the
process, in particular in relation to the non-linear equations. We discuss the
structure of this non-linear spin 3 Cotton equation but its explicit form is
only presented here, in an exact but not completely refined version, in
appended files obtained by computer algebra methods. Both the frame field and
metric formulations are provided.


title: The Influence of Magnetic Fields on UHECR Propagation from Virgo A

abstract:
  Active galactic nuclei (AGN) are considered as one of the most appropriate
sources of cosmic rays with energy exceeding $\sim 10^{18}$ eV. Virgo A (M87 or
NGC 4486) is the second closest to the Milky Way active galaxy. According to
existing estimations it can be a prominent source of ultra high energy cosmic
rays (UHECR). However not many events have been registered in the sky region
near Virgo A, possibly due to magnetic field influence. In the present work we
check UHECR events from the recent sets of data (AUGER, Telescope Array etc.)
for possibility of their origination in this AGN. We carried out the simulation
of UHECR motion from Virgo A taking into account their deflections in galactic
(GMF) as well as extragalactic (EGMF) magnetic fields according to the several
latest models. The maps of expected UHECR arrival directions were obtained as a
result. It has been found the following: 1) UHECR deflection caused by EGMF is
comparable with GMF one, moreover the influence of EGMF sometimes is
dominating; 2) effect of EGMF demonstrates obvious asymmetry in the final
distribution of expected UHECR arrival directions; 3) the results of
simulations depend on chosen GMF model and are still open for the discussion.


title:
Lignocellulosic biomass: a sustainable platform for the production of
  bio-based chemicals and polymers

abstract:
  The demand for petroleum dependent chemicals and materials has been
increasing despite the dwindling of their fossil resources. As the dead-end of
petroleum based industry has started to appear, today's modern society has to
implement alternative energy and valuable chemical resources immediately. Owing
to the importance of lignocellulosic biomass being the most abundant and
bio-renewable biomass on earth, this critical review provides insights into the
potential of lignocellulosic biomass as an alternative platform to fossil
resources. In this context, over 200 value-added compounds, which can be
derived from lignocellulosic biomass by various treatment methods, are
presented with their references. Lignocellulosic biomass based polymers and
their commercial importance are also reported mainly in the frame of these
compounds. This review article aims to draw the map of lignocellulosic biomass
derived chemicals and their synthetic polymers, and to reveal the scope of this
map in today's modern chemical and polymer industry.


title: Mapping the jamming transition of bidisperse mixtures

abstract:
  We systematically map out the jamming transition of all 2D bidisperse
mixtures of frictionless disks in the hard particle limit. The critical volume
fraction, mean coordination number, number of rattlers, structural order
parameters, and bulk modulus each show a rich variation with mixture
composition and particle size ratio, and can therefore be tuned by choosing
certain mixtures. We identify two local minima in the critical volume fraction,
both of which have low structural order; one minimum is close to the widely
studied 50:50 mixture of particles with a ratio of radii of 1:1.4. We also
identify a region at low size ratios characterized by increased structural
order and high rattler fractions, with a corresponding enhancement in the
stiffness.


title:
Dual approaches to the strongly convex simple function minimization
  problem under affine restrictions

abstract:
  We consider strongly convex optimization problems with affine-type
restrictions. We build dual problem and solve dual problem by Fast Gradient
Method. We use primal-dual structure of this method to construct the solution
of the primal problem. The paper contain a lot of different tricks that allows
to generalize mentioned above results for almost all methods we would like to
choose to solve the dual problem.


title: Some 4-manifold geometry from hyperbolic knots in S^3

abstract:
  A 4-manifold is constructed with some curious metric properties; or maybe it
is many 4-manifolds masquerading as one, which would explain why it looks
curious. Anyway, knots in the 3-sphere with complete finite volume hyperbolic
metrics on their complements play a role in this story.


title: On the 2015 outburst of the EXor variable star V1118 Ori

abstract:
  After a long-lasting period of quiescence of about a decade, the source V1118
Ori, one of the most representative members of the EXor variables, is now
outbursting. Since the initial increase of the near-infrared flux of about 1
mag (JHK bands) registered on 2015 September 22, the source brightness has
remained fairly stable. We estimate DeltaV about 3 mag with respect to the
quiescence phase. An optical/near-IR low-resolution spectrum has been obtained
with the Large Binocular Telescope instruments MODS and LUCI2, and compared
with a spectrum of similar spectral resolution and sensitivity level taken
during quiescence. Together with the enhancement of the continuum, the outburst
spectrum presents a definitely higher number of emission lines, in particular
HI recombination lines of the Balmer, Paschen, and Brackett series, along with
bright permitted lines of several species, forbidden atomic lines, and CO
ro-vibrational lines. Both mass accretion and mass loss rates have
significantly increased (by to about an order of magnitude, mass accretion rate
= 1.2-4.8 10^-8 M_sun/yr, mass loss rate = 0.8-2 10^-9 M_sun/yr) with respect
to the quiescence phase. If compared with previous outbursts, the present one
appears less energetic. Alternatively, it could already be in the fading phase
(with the maximum brightness level reached when the source was not visible),
or, viceversa, still in the rising phase.


title: A quantum protective mechanism in photosynthesis

abstract:
  Since the emergence of oxygenic photosynthesis, living systems have developed
protective mechanisms against reactive oxygen species. During charge separation
in photosynthetic reaction centres, triplet states can react with molecular
oxygen generating destructive singlet oxygen. The triplet product yield in
bacteria is observed to be reduced by weak magnetic fields. Reaction centres
from plants' photosystem II share many features with bacterial reaction
centres, including a high-spin iron whose function has remained obscure. To
explain observations that the magnetic field effect is reduced by the iron, we
propose that its fast-relaxing spin plays a protective role in photosynthesis
by generating an effective magnetic field. We consider a simple model of the
system, derive an analytical expression for the effective magnetic field and
analyse the resulting triplet yield reduction. The protective mechanism is
robust for realistic parameter ranges, constituting a clear example of a
quantum effect playing a macroscopic role vital for life.


title: Minimizing the Maximal Loss: How and Why?

abstract:
  A commonly used learning rule is to approximately minimize the \emph{average}
loss over the training set. Other learning algorithms, such as AdaBoost and
hard-SVM, aim at minimizing the \emph{maximal} loss over the training set. The
average loss is more popular, particularly in deep learning, due to three main
reasons. First, it can be conveniently minimized using online algorithms, that
process few examples at each iteration. Second, it is often argued that there
is no sense to minimize the loss on the training set too much, as it will not
be reflected in the generalization loss. Last, the maximal loss is not robust
to outliers. In this paper we describe and analyze an algorithm that can
convert any online algorithm to a minimizer of the maximal loss. We prove that
in some situations better accuracy on the training set is crucial to obtain
good performance on unseen examples. Last, we propose robust versions of the
approach that can handle outliers.


title: Noisy Metrology: A saturable lower bound on quantum Fisher information

abstract:
  In order to provide a guaranteed precision and a more accurate judgement
about the true value of the Cram\'{e}r-Rao bound and its scaling behavior, an
upper bound (equivalently a lower bound on the quantum Fisher information) for
precision of estimation is introduced. Unlike the bounds previously introduced
in the literature, the upper bound is saturable and yields a practical
instruction to estimate the parameter through preparing the optimal initial
state and optimal measurement. The bound is based on the underling dynamics and
its calculation is straightforward and requires only the matrix representation
of the quantum maps responsible for encoding the parameter. This allows us to
apply the bound to open quantum systems whose dynamics are described by either
semigroup or non-semigroup maps. Reliability and efficiency of the method to
predict the ultimate precision limit are demonstrated by {three} main examples.


title:
New Astrophysical Reaction Rate for the
  $^{12}\textrm{C}(\alpha,\gamma)^{16}\textrm{O}$ Reaction

abstract:
  A new astrophysical reaction rate for $^{12}$C($\alpha,\gamma$)$^{16}$O has
been evaluated on the basis of a global R-matrix fitting to the available
experimental data. The reaction rates of $^{12}$C($\alpha,\gamma$)$^{16}$O for
stellar temperatures between 0.04 $\leq$ $T_9$ $\leq$ 10 are provided in a
tabular form and by an analytical fitting expression. At $T_9$ = 0.2, the
reaction rate is (7.83 $\pm$ 0.35)$\times10^{15}$ $\rm{cm^3 mol^{-1} s^{-1}}$,
where stellar helium burning occurs.


title:
Thermodynamic aspects of information transfer in complex dynamical
  systems

abstract:
  From the Horowitz-Esposito stochastic thermodynamical description of
information flows in dynamical systems [J. M. Horowitz and M. Esposito, Phys.
Rev. X4, 031015 (2014)], it is known that while the second law of
thermodynamics is satisfied by a joint system, the entropic balance for the
subsystems is adjusted by a term related to the mutual information exchange
rate between the two subsystems. In this article, we present a quantitative
discussion of the conceptual link between the Horowitz-Esposito analysis and
the Liang-Kleeman work on information transfer between dynamical system
components [X. S. Liang and R. Kleeman, Phys. Rev. Lett. 95, 244101 (2005)]. In
particular, the entropic balance arguments employed in the two approaches are
compared. Notwithstanding all differences between the two formalisms, our work
strengthens the Liang-Kleeman heuristic balance reasoning by showing its formal
analogy with the recent Horowitz-Esposito thermodynamic balance arguments.


title:
Very Hight Energy Observationa of Shell-Type Supernova Remnants with
  SHALON Mirror Cherenkov Telescopes

abstract:
  The investigation of VHE gamma-ray sources by any methods, including mirror
Cherenkov telescopes, touches on the problem of the cosmic ray origin and,
accordingly, the role of the Galaxy in their generation. The SHALON
observations have yielded the results on Galactic shell-type supernova remnants
(SNR) on different evolution stages. Among them are: SNRs Tycho's SNR, Cas A,
IC 443, $\gamma$Cygni SNR and classical nova GK Per (Nova 1901). For each of
SNRs the observation results are presented with spectral energy distribution by
SHALON in comparison with other experiment data and images by SHALON. The
collected experimental data have confirmed the prediction of the theory about
the hadronic generation mechanism of very high energy 800 GeV - 100 TeV
$\gamma$-rays in Tycho's SNR, Cas A and IC443.


title:
Effect of non-specific interactions on formation and stability of
  specific complexes

abstract:
  We introduce a simple model to describe the interplay between specific and
non-specific interactions. We study the influence of various physical factors
on the static and dynamic properties of the specific interactions of our model
and show that contrary to intuitive expectations, non-specific interactions can
assist in the formation of specific complexes and increase their stability. We
then discuss the relevance of these results for biological systems.


title: Measurement of Chern numbers through center-of-mass responses

abstract:
  Probing the center-of-mass of an ultracold atomic cloud can be used to
measure Chern numbers, the topological invariants underlying the quantum Hall
effects. In this work, we show how such center-of-mass observables can have a
much richer dependence on topological invariants than previously discussed. In
fact, the response of the center of mass depends not only on the current
density, typically measured in a solid-state system, but also on the particle
density, which itself can be sensitive to the topology of the band structure.
We apply a semiclassical approach, supported by numerical simulations, to
highlight the key differences between center-of-mass responses and more
standard conductivity measurements. We illustrate this by analyzing both the
two- and the four-dimensional quantum Hall effects. These results have
important implications for experiments in engineered topological systems, such
as ultracold gases and photonics.


title: Domination in 3-tournaments

abstract:
  A 3-tournament is a complete 3-uniform hypergraph where each edge has a
special vertex designated as its tail. A vertex set $X$ dominates $T$ if every
vertex not in $X$ is contained in an edge whose tail is in $X$. The domination
number of $T$ is the minimum size of such an $X$. Generalizing well-known
results about usual (graph) tournaments, Gy\'arf\'as conjectured that there are
3-tournaments with arbitrarily large domination number, and that this is not
the case if any four vertices induce two triples with the same tail. In this
short note we solve both problems, proving the first conjecture and refuting
the second.


title:
Contact Interactions in Higgs-Vector Boson Associated Production at the
  ILC

abstract:
  We explore new physics (NP) effects in Higgs-Vector boson associated
production at a future International Linear Collider (ILC) via e+e- -> Zh,Zhh,
using effective field theory (EFT) techniques. In particular, we focus on a
certain class of dimension 6 operators, which are generated by tree-level
exchanges of a new heavy vector field in the underlying theory. These operators
induce new contact terms of the form \psi\psi\phi D\phi, involving the Standard
Model (SM) fermions (\psi), gauge-bosons (D is the covariant derivative) and
the SM Higgs field (\phi). We investigate the high-energy behaviour of these
new effective interactions in e+e- -> Zh,Zhh, imposing bounds from electroweak
precision measurements, and show that the ILC is an excellent testing ground
for probing this type of NP via e+e- -> Zh,Zhh. We also address the validity of
the EFT expansion and we study the correlation between the hZ and hhZ signals,
which can be utilized in future searches for NP in these channels.


title:
Radiative natural SUSY spectrum from deflected AMSB scenario with
  messenger-matter interactions

abstract:
  A radiative natural SUSY spectrum are proposed in the deflected anomaly
mediation scenario with general messenger-matter interactions. Due to the
contributions from the new interactions, positive slepton masses as well as a
large |A_t| term can naturally be obtained with either sign of deflection
parameter and few messenger species (thus avoid the possible Landau pole
problem). In this scenario, in contrast to the ordinary (radiative) natural
SUSY scenario with under-abundance of dark matter (DM), the DM can be the mixed
bino-higgsino and have the right relic density. The 125 GeV Higgs mass can also
be easily obtained in our scenario. The majority of low EW fine tuning points
can be covered by the XENON-1T direct detection experiments.


title:
The large deviations of the whitening process in random constraint
  satisfaction problems

abstract:
  Random constraint satisfaction problems undergo several phase transitions as
the ratio between the number of constraints and the number of variables is
varied. When this ratio exceeds the satisfiability threshold no more solutions
exist; the satisfiable phase, for less constrained problems, is itself divided
in an unclustered regime and a clustered one. In the latter solutions are
grouped in clusters of nearby solutions separated in configuration space from
solutions of other clusters. In addition the rigidity transition signals the
appearance of so-called frozen variables in typical solutions: beyond this
threshold most solutions belong to clusters with an extensive number of
variables taking the same values in all solutions of the cluster. In this paper
we refine the description of this phenomenon by estimating the location of the
freezing transition, corresponding to the disappearance of all unfrozen
solutions (not only typical ones). We also unveil phase transitions for the
existence and uniqueness of locked solutions, in which all variables are
frozen. From a technical point of view we characterize atypical solutions with
a number of frozen variables different from the typical value via a large
deviation study of the dynamics of a stripping process (whitening) that unveils
the frozen variables of a solution, building upon recent works on atypical
trajectories of the bootstrap percolation dynamics. Our results also bear some
relevance from an algorithmic perspective, previous numerical studies having
shown that heuristic algorithms of various kinds usually output unfrozen
solutions.

categories: cond-mat.dis-nn cond-mat.stat-mech cs.DM math.PR


title:
Kinematic constrains on interacting nucleons in $Pb+Pb$ collisions at
  $\sqrt{s_{NN}}=2.76$ TeV within the HIJING code

abstract:
  The kinematic constrains on interacting nucleons in Large Hadron Collider
(LHC) heavy-ion collisions are investigated in the framework of the Heavy Ion
Jet Interaction Generator (HIJING) code incorporated with a collective cascade
recipe. The latter is used to implement energy-momentum conservation constrains
on both primary and secondary interacting nucleons. It is found that the
energy-momentum conservation constrains on the interacting nucleons affect the
whole charged particle pseudo-rapidity density distribution
$(\frac{dN_{ch}}{d\eta})$, at different centralities (from central (0-5\%) to
peripheral (70-80\%) collisions), in Pb+Pb collisions at $\sqrt{s_{NN}} =2.76$
TeV. In particular, the kinematic constrains on interacting nucleons are shown
to reduce $(\frac{dN_{ch}}{d\eta})$ yield at mid-pseudorapidity
$(\lvert\eta\rvert<2)$ in all centrality intervals, which is consistent with
the LHC data. In addition, the model predicts an enhancement of the hadron
production at $\lvert\eta\rvert>8$, which could be checked in future ALICE Zero
Degree calorimeter. Such an enhancement is found to be mainly due to the
interactions of protons at the spectator parts of the collision. This indicates
that the kinematic constrains are important for a correct geometrical treatment
of Pb+Pb collisions at LHC energies.


title:
Design and Performance of a Lead Fluoride Detector as a Luminosity
  Monitor

abstract:
  Precise luminosity measurements for the OLYMPUS two-photon exchange
experiment at DESY were performed by counting scattering events with
alternating beams of electrons and positrons incident on atomic electrons in a
gaseous hydrogen target. Final products of M{\o}ller, Bhabha, and pair
annihilation interactions were observed using a pair of lead fluoride Cherenkov
calorimeters with custom housings and electronics, adapted from a system used
by the A4 parity violation experiment at MAMI. This paper describes the design,
calibration, and operation of these detectors. An explanation of the Monte
Carlo methods used to simulate the physical processes involved both at the
scattering vertices and in the detector apparatus is also included.


title:
Direct Arbitrary-Lagrangian-Eulerian finite volume schemes on moving
  nonconforming unstructured meshes

abstract:
  In this paper, we present a novel second-order accurate
Arbitrary-Lagrangian-Eulerian (ALE) finite volume scheme on moving
nonconforming polygonal grids, in order to avoid the typical mesh distortion
caused by shear flows in Lagrangian-type methods. In our new approach the
nonconforming element interfaces are not defined by the user, but they are
automatically detected by the algorithm if the tangential velocity difference
across an element interface is sufficiently large. The grid nodes that are
sufficiently far away from a shear wave are moved with a standard node solver,
while at the interface we insert a new set of nodes that can slide in a
nonconforming manner. In this way, the elements on both sides of the shear wave
can move with a different velocity, without producing highly distorted
elements. The core of the proposed method is the use of a space-time
conservation formulation in the construction of the final finite volume scheme,
which completely avoids the need of an additional remapping stage and ensures
that the geometric conservation law (GCL) is automatically satisfied. Moreover,
the mesh quality remains high and, as a direct consequence, also the time step
remains almost constant in time, even for highly sheared vortex flows. The
accuracy of the new scheme has been further improved by incorporating a special
well balancing technique that is able to maintain particular stationary
solutions of the governing PDE system up to machine precision. A large set of
numerical tests has been carried out in order to check the accuracy and the
robustness of the new method. In particular we have compared the results for a
steady vortex in equilibrium solved with a standard conforming ALE method and
with our new nonconforming ALE scheme, to show that the new nonconforming
scheme is able to avoid mesh distortion even after very long simulation times.


title:
Bilayer graphene under pressure: Electron-hole Symmetry Breaking, Valley
  Hall Effect, and Landau Levels

abstract:
  The electronic structure of bilayer graphene under pressure develops very
interesting features with an enhancement of the trigonal warping and a
splitting of the parabolic touching bands at the K point of the reciprocal
space into four Dirac cones, one at K and three along the T symmetry lines. As
pressure is increased, these cones separate in reciprocal space and in energy,
breaking the electron-hole symmetry. Due to their energy separation, their
opposite Berry curvature can be observed in valley Hall effect experiments and
in the structure of the Landau levels. Based on the electronic structure
obtained by Density Functional Theory, we develop a low energy Hamiltonian that
describes the effects of pressure on measurable quantities such as the Hall
conductivity and the Landau levels of the system.


title: Gravity and Cosmology with Interacting Dark Energy

abstract:
  Dark energy (DE) is not necessarily uniform when other sources of gravity are
present: interaction with matter leads to its variation in space and time. We
study cosmological implications of this fact by analyzing cosmological models
in which DE density interacts with matter and thus changes with time. We model
the DE--matter interaction by specifying the rate of change of the DE density
as an arbitrary function of it and the density of matter, in a single--phase
case. In the case of several matter components interacting with dark energy we
assume the rate of every interacting phase density to be an arbitrary function
of this density and the DE density. We describe some properties of cosmological
solutions valid for a general law of DE--matter interaction, and discuss
physical admissibility of the interaction laws. We study numerous families of
exact solutions, both singular, non-singular, and mixed. Some of them exhibit
interesting properties, such as, for instance, absence of the horizon problem
due to the initial fast growth of the scale factor (any power of time
possible); non-singular evolution from one de Sitter universe (pure DE with no
matter) to the other one with a different DE density; DE dominating either from
some moment of time on, or throughout the expansion; dark matter dominating
normal matter at large times without any parameter tuning, and so on. All the
results are obtained strictly within the framework of general relativity,
Einstein's theory of gravity, without modifying it in any way.


title:
$L$-series associated to symmetric functions mod $N$ with applications
  related to $\zeta(3)$, $\zeta(5)$

abstract:
  We develop a new theory of $L$-series based on replacing Dirichlet characters
mod $N$ by symmetric functions mod $N$ in order to calculate explicitly the
sums of infinite series more closely related to $\zeta(2n+1)$, specifically
$\zeta(3)$, $\zeta(5)$. This generalizes the corresponding theory of sums of
$L$-series associated to Dirichlet characters.


title: Curve packing and modulus estimates

abstract:
  A family of planar curves is called a Moser family if it contains an
isometric copy of every rectifiable curve in $\mathbb{R}^{2}$ of length one.
The classical "worm problem" of L. Moser from 1966 asks for the least area
covered by the curves in any Moser family. In 1979, J. M. Marstrand proved that
the answer is not zero: the union of curves in a Moser family has always area
at least $c$ for some small absolute constant $c > 0$. We strengthen
Marstrand's result by showing that for $p > 3$, the $p$-modulus of a Moser
family of curves is at least $c_{p} > 0$.


title: The R1R2' outer ring revealed by young open cluster data

abstract:
  The distribution of young open clusters in the Galactic plane suggests the
existence of the outer ring R1R2' in the Galaxy. The solar position angle
theta_b providing the best agreement between the observed and model
distribution is theta_b=35 +\- 10 degrees. We compared the theta_b values
derived from three different catalogues of open cluster and they appear to be
consistent within the errors.


title: Temperature dependence of slow positron reemission from metals

abstract:
  Intensity of positron reemission from a metal is related to its work
function. This property is dependent on temperature and can be modified with
temperature control. In this article a simple model is proposed to explain and
predict the variation of the positron work function with temperature. The
dependence of slow positron yield of metals on temperature is predicted based
on this model and the critical temperatures at which the slow positron yield is
maximum is calculated. The proposed model is consistent with experimental
observations.


title:
Persistence of slow fluctuations in the overdoped regime of
  Ba(Fe1-xRhx)2As2 superconductors

abstract:
  We present nuclear magnetic resonance evidence that very slow ($\leq 1$ MHz)
spin fluctuations persist into the overdoped regime of
Ba(Fe$_{1-x}$Rh$_{x}$)$_2$As$_2$ superconductors. Measurements of the $^{75}$As
spin echo decay rate, obtained both with Hahn Echo and Carr Purcell Meiboom
Gill pulse sequences, show that the slowing down of spin fluctuations can be
described by short-range diffusive dynamics, likely involving domain walls
motions separating $(\pi/a,0)$ from $(0,\pi/a)$ correlated regions. This
slowing down of the fluctuations is weakly sensitive to the external magnetic
field and, although fading away with doping, it extends deeply into the
overdoped regime.


title:
The Great Time Series Classification Bake Off: An Experimental
  Evaluation of Recently Proposed Algorithms. Extended Version

abstract:
  In the last five years there have been a large number of new time series
classification algorithms proposed in the literature. These algorithms have
been evaluated on subsets of the 47 data sets in the University of California,
Riverside time series classification archive. The archive has recently been
expanded to 85 data sets, over half of which have been donated by researchers
at the University of East Anglia. Aspects of previous evaluations have made
comparisons between algorithms difficult. For example, several different
programming languages have been used, experiments involved a single train/test
split and some used normalised data whilst others did not. The relaunch of the
archive provides a timely opportunity to thoroughly evaluate algorithms on a
larger number of datasets. We have implemented 18 recently proposed algorithms
in a common Java framework and compared them against two standard benchmark
classifiers (and each other) by performing 100 resampling experiments on each
of the 85 datasets. We use these results to test several hypotheses relating to
whether the algorithms are significantly more accurate than the benchmarks and
each other. Our results indicate that only 9 of these algorithms are
significantly more accurate than both benchmarks and that one classifier, the
Collective of Transformation Ensembles, is significantly more accurate than all
of the others. All of our experiments and results are reproducible: we release
all of our code, results and experimental details and we hope these experiments
form the basis for more rigorous testing of new algorithms in the future.


title: Building blocks of the basin stability of power grids

abstract:
  Given a power grid and a transmission (coupling) strength, basin stability is
a measure of synchronization stability for individual nodes. Earlier studies
have focused on the basin stability's dependence of the position of the nodes
in the network for single values of transmission strength. Basin stability
grows from zero to one as transmission strength increases, but often in a
complex, nonmonotonous way. In this study, we investigate the entire functional
form of the basin stability's dependence on transmission strength. To be able
to perform a systematic analysis, we restrict ourselves to small networks. We
scan all isomorphically distinct networks with an equal number of power
producers and consumers of six nodes or less. We find that the shapes of the
basin stability fall into a few, rather well-defined classes, that could be
characterized by the number of edges and the betweenness of the nodes, whereas
other network positional quantities matter less.


title:
Detection of binary and multiple systems among rapidly rotating K and M
  dwarf stars from Kepler data

abstract:
  From an examination of ~18,000 Kepler light curves of K- and M-stars we find
some 500 which exhibit rotational periods of less than 2 days. Among such
stars, approximately 50 show two or more incommensurate periodicities. We
discuss the tools that allow us to differentiate between rotational modulation
and other types of light variations, e.g., due to pulsations or binary
modulations. We find that these multiple periodicities are independent of each
other and likely belong to different, but physically bound, stars. This
scenario was checked directly by UKIRT and adaptive optics imaging,
time-resolved Fourier transforms, and pixel-level analysis of the data. Our
result is potentially important for discovering young multiple stellar systems
among rapidly rotating K- and M-dwarfs.


title: Anticommutative extension of the Adler map

abstract:
  We construct a noncommutative (Grassmann) extension of the well known Adler
Yang-Baxter map. It satisfies the Yang-Baxter equation, it is reversible and
birational. Our extension preserves all the properties of the original map
except the involutivity.


title: Loop equations from differential systems

abstract:
  To any differential system $d\Psi=\Phi\Psi$ where $\Psi$ belongs to a Lie
group (a fiber of a principal bundle) and $\Phi$ is a Lie algebra $\mathfrak g$
valued 1-form on a Riemann surface $\Sigma$, is associated an infinite sequence
of "correlators" $W_n$ that are symmetric $n$-forms on $\Sigma^n$. The goal of
this article is to prove that these correlators always satisfy "loop
equations", the same equations satisfied by correlation functions in random
matrix models, or the same equations as Virasoro or W-algebra constraints in
CFT.


title:
Decentralized Prediction-Correction Methods for Networked Time-Varying
  Convex Optimization

abstract:
  We develop algorithms that find and track the optimal solution trajectory of
time-varying convex optimization problems which consist of local and
network-related objectives. The algorithms are derived from the
prediction-correction methodology, which corresponds to a strategy where the
time-varying problem is sampled at discrete time instances and then a sequence
is generated via alternatively executing predictions on how the optimizers at
the next time sample are changing and corrections on how they actually have
changed. Prediction is based on how the optimality conditions evolve in time,
while correction is based on a gradient or Newton method, leading to
Decentralized Prediction-Correction Gradient (DPC-G) and Decentralized
Prediction-Correction Newton (DPC-N). We extend these methods to cases where
the knowledge on how the optimization programs are changing in time is only
approximate and propose Decentralized Approximate Prediction-Correction
Gradient (DAPC-G) and Decentralized Approximate Prediction-Correction Newton
(DAPC-N). Convergence properties of all the proposed methods are studied and
empirical performance is shown on an application of a resource allocation
problem in a wireless network. We observe that the proposed methods outperform
existing running algorithms by orders of magnitude. The numerical results
showcase a trade-off between convergence accuracy, sampling period, and network
communications.


title: The structure of fluctuations in stochastic homogenization

abstract:
  Four quantities are fundamental in homogenization of elliptic systems in
divergence form and in its applications: the field and the flux of the solution
operator (applied to a general deterministic right-hand side), and the field
and the flux of the corrector. Homogenization is the study of the large-scale
properties of these objects. In case of random coefficients, these quantities
fluctuate and their fluctuations are a priori unrelated. Depending on the law
of the coefficient field, and in particular on the decay of its correlations on
large scales, these fluctuations may display different scalings and different
limiting laws (if any). In this contribution, we identify another crucial
intrinsic quantity, motivated by H-convergence, which we refer to as the
\emph{homogenization commutator} and is related to variational quantities first
considered by Armstrong and Smart. In the simplified setting of the random
conductance model, we show what we believe to be a general principle, namely
that the homogenization commutator drives at leading order the fluctuations of
each of the four other quantities in a strong norm in probability, which is
expressed in form of a suitable two-scale expansion and reveals the
\emph{pathwise structure} of fluctuations in stochastic homogenization. In
addition, we show that the (rescaled) homogenization commutator converges in
law to a Gaussian white noise, and we analyze to which precision the covariance
tensor that characterizes the latter can be extracted from the representative
volume element method. This collection of results constitutes a new theory of
fluctuations in stochastic homogenization that holds in any dimension and
yields optimal rates. Extensions to the (non-symmetric) continuum setting are
also discussed, the details of which are postponed to forthcoming works.


title: Formal Verification of Autonomous Vehicle Platooning

abstract:
  The coordination of multiple autonomous vehicles into convoys or platoons is
expected on our highways in the near future. However, before such platoons can
be deployed, the new autonomous behaviors of the vehicles in these platoons
must be certified. An appropriate representation for vehicle platooning is as a
multi-agent system in which each agent captures the "autonomous decisions"
carried out by each vehicle. In order to ensure that these autonomous
decision-making agents in vehicle platoons never violate safety requirements,
we use formal verification. However, as the formal verification technique used
to verify the agent code does not scale to the full system and as the global
verification technique does not capture the essential verification of
autonomous behavior, we use a combination of the two approaches. This mixed
strategy allows us to verify safety requirements not only of a model of the
system, but of the actual agent code used to program the autonomous vehicles.


title:
The effect of ambipolar electric fields on the electron heating in
  capacitive RF plasmas

abstract:
  We investigate the electron heating dynamics in electropositive argon and
helium capacitively coupled RF discharges driven at 13.56 MHz by Particle in
Cell simulations and by an analytical model. The model allows to calculate the
electric field outside the electrode sheaths, space and time resolved within
the RF period. Electrons are found to be heated by strong ambipolar electric
fields outside the sheath during the phase of sheath expansion in addition to
classical sheath expansion heating. By tracing individual electrons we also
show that ionization is primarily caused by electrons that collide with the
expanding sheath edge multiple times during one phase of sheath expansion due
to backscattering towards the sheath by collisions. A synergistic combination
of these different heating events during one phase of sheath expansion is
required to accelerate an electron to energies above the threshold for
ionization. The ambipolar electric field outside the sheath is found to be time
modulated due to a time modulation of the electron mean energy caused by the
presence of sheath expansion heating only during one half of the RF period at a
given electrode. This time modulation results in more electron heating than
cooling inside the region of high electric field outside the sheath on time
average. If an electric field reversal is present during sheath collapse, this
time modulation and, thus, the asymmetry between the phases of sheath expansion
and collapse will be enhanced. We propose that the ambipolar electron heating
should be included in models describing electron heating in capacitive RF
plasmas.


title:
$L^2$-Stability of Traveling Wave Solutions to Nonlocal Evolution
  Equations

abstract:
  Stability of the traveling wave solution to a general class of
one-dimensional nonlocal evolution equations is studied in $L^2$-spaces,
thereby providing an alternative approach to the usual spectral analysis with
respect to the supremum norm. We prove that the linearization around the
traveling wave solution satisfies a Lyapunov-type stability condition in a
weighted space $L^2(\rho)$ for a naturally associated density $\rho$. The
result can be applied to obtain stability of the traveling wave solution under
stochastic perturbations of additive or multiplicative type. For small wave
speeds, we also prove an alternative Lyapunov-type stability condition in
$L^2(\mathfrak{m})$, where $\mathfrak{m}$ is the symmetrizing density for the
traveling wave operator, which allows to derive a long-term stochastic
stability result.


title:
Spiral-driven accretion in protoplanetary discs - II Self-similar
  solutions

abstract:
  Accretion discs are ubiquitous in the universe and it is a crucial issue to
understand how angular momentum and mass are being radially transported in
these objects. Here, we study the role played by non-linear spiral patterns
within hydrodynamical and non self-gravitating accretion disc assuming that
external disturbances such as infall onto the disc may trigger them. To do so,
we computed self-similar solutions that describe discs in which a spiral wave
propagates. Such solutions present both shocks and critical sonic points that
we carefully analyze. For all allowed temperatures and for several spiral
shocks, we calculated the wave structure. In particular we inferred the angle
of the spiral patern, the stress it exerts on the disc as well as the
associated flux of mass and angular momentum as a function of temperature. We
quantified the rate of angular momentum transport by means of the dimensionless
$\alpha$ parameter. For the thickest disc we considered (corresponding to $h/r$
values of about 1/3), we found values of $\alpha$ as high as $0.1$, and scaling
with the temperature $T$ such that $\alpha \propto T^{3/2} \propto (h/r)^3$.
The spiral angle scales with the temperature as $\arctan(r/h)$. The existence
of these solutions suggests that perturbations occurring at disc outer
boundaries, such as for example perturbations due to infall motions, can
propagate deep inside the disc and therefore should not be ignored, even when
considering small radii.


title: Breather solitons in highly nonlocal media

abstract:
  We investigate the breathing of optical spatial solitons in highly nonlocal
media. Generalizing the Ehrenfest theorem, we demonstrate that oscillations in
beam width obey a fourth-order ordinary differential equation. Moreover, in
actual highly nonlocal materials, the original accessible soliton model by
Snyder and Mitchell [Science \textbf{276}, 1538 (1997)] cannot accurately
describe the dynamics of self-confined beams as the transverse size
oscillations have a period which not only depends on power but also on the
initial width. Modeling the nonlinear response by a Poisson equation driven by
the beam intensity we verify the theoretical results against numerical
simulations.


title: Cavity-induced chiral states of fermionic quantum gases

abstract:
  We investigate ultra-cold fermions placed into an optical cavity and
subjected to optical lattices which confine the atoms to ladder structures. A
transverse running-wave laser beam induces together with the dynamical cavity
field a two-photon Raman-assisted tunneling process with spatially dependent
phase imprint along the rungs of the ladders. We identify the steady states
which can occur by the feedback mechanism between the cavity field and the
atoms. We find the spontaneous emergence of a finite cavity field amplitude
which leads to an artificial magnetic field felt by the fermionic atoms. These
form a chiral insulating or chiral liquid state carrying a chiral current. We
explore the rich state diagram as a function of the power of the transverse
laser beam, the atomic filling, and the phase imprint during the cavity-induced
tunneling. Both a sudden onset or a slow exponential activation with the
transverse laser power of the self-organized chiral states can occur.


title:
Dust masses of disks around 8 Brown Dwarfs and Very Low-Mass Stars in
  Upper Sco OB1 and Ophiuchus

abstract:
  We present the results of ALMA band 7 observations of dust and CO gas in the
disks around 7 objects with spectral types ranging between M5.5 and M7.5 in
Upper Scorpius OB1, and one M3 star in Ophiuchus. We detect unresolved
continuum emission in all but one source, and the $^{12}$CO J=3-2 line in two
sources. We constrain the dust and gas content of these systems using a grid of
models calculated with the radiative transfer code MCFOST, and find disk dust
masses between 0.1 and 1 M$_\oplus$, suggesting that the stellar mass / disk
mass correlation can be extrapolated for brown dwarfs with masses as low as
0.05 M$_\odot$. The one disk in Upper Sco in which we detect CO emission, 2MASS
J15555600, is also the disk with warmest inner disk as traced by its H - [4.5]
photometric color. Using our radiative transfer grid, we extend the correlation
between stellar luminosity and mass-averaged disk dust temperature originally
derived for stellar mass objects to the brown dwarf regime to $\langle T_{dust}
\rangle \approx 22 (L_{*} /L_{\odot})^{0.16} K$, applicable to spectral types
of M5 and later. This is slightly shallower than the relation for earlier
spectral type objects and yields warmer low-mass disks. The two prescriptions
cross at 0.27 L$_\odot$, corresponding to masses between 0.1 and 0.2 M$_\odot$
depending on age.


title: High-Throughput ab-initio Dilute Solute Diffusion Database

abstract:
  We demonstrate automated generation of diffusion databases from
high-throughput density functional theory (DFT) calculations. A total of more
than 230 dilute solute diffusion systems in Mg, Al, Cu, Ni, Pd, and Pt host
lattices have been determined using multi-frequency diffusion models. We apply
a correction method for solute diffusion in alloys using experimental and
simulated values of host self-diffusivity. We find good agreement with
experimental solute diffusion data, obtaining a weighted activation barrier RMS
error of 0.176 eV when excluding magnetic solutes in non-magnetic alloys. The
compiled database is the largest collection of consistently calculated
ab-initio solute diffusion data in the world.


title:
Continuum theory of swelling material surfaces with applications to
  thermo-responsive gel membranes and surface mass transport

abstract:
  Soft membranes are commonly employed in shape-morphing applications, where
the material is programmed to achieve a target shape upon activation by an
external trigger, and as coating layers that alter the surface characteristics
of bulk materials, such as the properties of spreading and absorption of
liquids. In particular, polymer gel membranes experience swelling or shrinking
when their solvent content change, and the non-homogeneous swelling field may
be exploited to control their shape. Here, we develop a theory of swelling
material surfaces to model polymer gel membranes and demonstrate its features
by numerically studying applications in the contexts of biomedicine,
micro-motility, and coating technology. We also specialize the theory to
thermo-responsive gels, which are made of polymers that change their affinity
with a solvent when temperature varies.


title: Some manifolds of Khinchin type for convergence

abstract:
  Recently, Beresnevich, Vaughan, Velani, and Zorin (arXiv: 1506.09049) gave
some sufficient conditions for a manifold to be of Khinchin type for
convergence. We show that their techniques can be used in a more optimal way to
yield stronger results. In the process we also improve a theorem of Dodson,
Rynne, and Vickers ('89).


title: NeRD: a Neural Response Divergence Approach to Visual Salience Detection

abstract:
  In this paper, a novel approach to visual salience detection via Neural
Response Divergence (NeRD) is proposed, where synaptic portions of deep neural
networks, previously trained for complex object recognition, are leveraged to
compute low level cues that can be used to compute image region
distinctiveness. Based on this concept , an efficient visual salience detection
framework is proposed using deep convolutional StochasticNets. Experimental
results using CSSD and MSRA10k natural image datasets show that the proposed
NeRD approach can achieve improved performance when compared to
state-of-the-art image saliency approaches, while the attaining low
computational complexity necessary for near-real-time computer vision
applications.


title:
Correntropy Maximization via ADMM - Application to Robust Hyperspectral
  Unmixing

abstract:
  In hyperspectral images, some spectral bands suffer from low signal-to-noise
ratio due to noisy acquisition and atmospheric effects, thus requiring robust
techniques for the unmixing problem. This paper presents a robust supervised
spectral unmixing approach for hyperspectral images. The robustness is achieved
by writing the unmixing problem as the maximization of the correntropy
criterion subject to the most commonly used constraints. Two unmixing problems
are derived: the first problem considers the fully-constrained unmixing, with
both the non-negativity and sum-to-one constraints, while the second one deals
with the non-negativity and the sparsity-promoting of the abundances. The
corresponding optimization problems are solved efficiently using an alternating
direction method of multipliers (ADMM) approach. Experiments on synthetic and
real hyperspectral images validate the performance of the proposed algorithms
for different scenarios, demonstrating that the correntropy-based unmixing is
robust to outlier bands.


title:
The deterministic Kermack-McKendrick model bounds the general stochastic
  epidemic

abstract:
  We prove that, for Poisson transmission and recovery processes, the classic
Susceptible $\to$ Infected $\to$ Recovered (SIR) epidemic model of Kermack and
McKendrick provides, for any given time $t>0$, a strict lower bound on the
expected number of suscpetibles and a strict upper bound on the expected number
of recoveries in the general stochastic SIR epidemic. The proof is based on the
recent message passing representation of SIR epidemics applied to a complete
graph.

categories: q-bio.PE cond-mat.stat-mech math.PR physics.soc-ph


title:
Multi-Objective Framework for Dynamic Optimization of OFDMA Cellular
  Systems

abstract:
  Green cellular networking has become an important research area in recent
years due to environmental and economical concerns. Switching off
under-utilized BSs during off-peak traffic load conditions is a promising
approach to reduce energy consumption in cellular networks. In practice, during
initial cell planning, the BS locations and RAN parameters are optimized to
meet the basic system design requirements like coverage, capacity, overlap, QoS
etc. As these metrics are tightly coupled with each other due to co-channel
interference, switching off certain BSs may affect the system requirements.
Therefore, identifying a subset of large number of BSs which are to be put into
sleep mode, is a challenging dynamic optimization problem. In this work, we
develop a multiobjective framework for dynamic optimization framework for OFDMA
based cellular systems. The objective is to identify the appropriate set of
active sectors and RAN parameters that maximize coverage and area spectral
efficiency while minimizing overlap and area power consumption without
violating the QoS requirements for a given traffic demand density. The
objective functions and constraints are obtained using appropriate analytical
models which capture the traffic characteristics, propagation characteristics
(pathloss, shadowing, and small scale fading) as well as load condition in
neighbouring cells. A low complexity evolutionary algorithm is used for
identifying the global Pareto optimal solutions at a faster convergence rate.
The inter-relationships between the system objectives are studied and
guidelines are provided to find an appropriate network configuration that
provides the best achievable trade-offs. The results show that using the
proposed framework, significant amount of energy saving can be achieved and
with a low computational complexity while maintaining good trade-offs among the
other objectives.


title: Buffer-aware Worst Case Timing Analysis of Wormhole Network On Chip

abstract:
  A buffer-aware worst-case timing analysis of wormhole NoC is proposed in this
paper to integrate the impact of buffer size on the different dependencies
relationship between flows, i.e. direct and indirect blocking flows, and
consequently the timing performance. First, more accurate definitions of direct
and indirect blocking flows sets have been introduced to take into account the
buffer size impact. Then, the modeling and worst-case timing analysis of
wormhole NoC have been detailed, based on Network Calculus formalism and the
newly defined blocking flows sets. This introduced approach has been
illustrated in the case of a realistic NoC case study to show the trade off
between latency and buffer size. The comparative analysis of our proposed
Buffer-aware timing analysis with conventional approaches is conducted and
noticeable enhancements in terms of maximum latency have been proved.