title:
On algorithms with good mesh properties for problems with moving
  boundaries based on the Harmonic Map Heat Flow and the DeTurck trick

abstract:
  In this paper, we present a general approach to obtain numerical schemes with
good mesh properties for problems with moving boundaries, that is for evolving
submanifolds with boundaries. This includes moving domains and surfaces with
boundaries. Our approach is based on a variant of the so-called the DeTurck
trick. By reparametrizing the evolution of the submanifold via solutions to the
harmonic map heat flow of manifolds with boundary, we obtain a new velocity
field for the motion of the submanifold. Moving the vertices of the
computational mesh according to this velocity field automatically leads to
computational meshes of high quality both for the submanifold and its boundary.
Using the ALE-method in [16], this idea can be easily built into algorithms for
the computation of physical problems with moving boundaries.


title:
Unified rheology of vibro-fluidized dry granular media: From slow dense
  flows to fast gas-like regimes

abstract:
  Granular media take on great importance in industry and geophysics, posing a
severe challenge to materials science. Their response properties elude known
soft rheological models, even when the yield-stress discontinuity is blurred by
vibro-fluidization. Here we propose a broad rheological scenario where average
stress sums up a frictional contribution, generalizing conventional
$\mu(I)$-rheology, and a kinetic collisional term dominating at fast
fluidization. Our conjecture fairly describes a wide series of experiments in a
vibrofluidized vane setup, whose phenomenology includes velocity weakening,
shear thinning, a discontinuous thinning transition, and gaseous shear
thickening. The employed setup gives access to dynamic fluctuations, which
exhibit a broad range of timescales. In the slow dense regime the frequency of
cage-opening increases with stress and enhances, with respect to
$\mu(I)$-rheology, the decrease of viscosity. Diffusivity is exponential in the
shear stress in both thinning and thickening regimes, with a huge growth near
the transition.


title: Is spatial information in ICT data reliable?

abstract:
  An increasing number of human activities are studied using data produced by
individuals' ICT devices. In particular, when ICT data contain spatial
information, they represent an invaluable source for analyzing urban dynamics.
However, there have been relatively few contributions investigating the
robustness of this type of results against fluctuations of data
characteristics. Here, we present a stability analysis of higher-level
information extracted from mobile phone data passively produced during an
entire year by 9 million individuals in Senegal. We focus on two
information-retrieval tasks: (a) the identification of land use in the region
of Dakar from the temporal rhythms of the communication activity; (b) the
identification of home and work locations of anonymized individuals, which
enable to construct Origin-Destination (OD) matrices of commuting flows. Our
analysis reveal that the uncertainty of results highly depends on the sample
size, the scale and the period of the year at which the data were gathered.
Nevertheless, the spatial distributions of land use computed for different
samples are remarkably robust: on average, we observe more than 75% of shared
surface area between the different spatial partitions when considering activity
of at least 100,000 users whatever the scale. The OD matrix is less stable and
depends on the scale with a share of at least 75% of commuters in common when
considering all types of flows constructed from the home-work locations of
100,000 users. For both tasks, better results can be obtained at larger levels
of aggregation or by considering more users. These results confirm that ICT
data are very useful sources for the spatial analysis of urban systems, but
that their reliability should in general be tested more thoroughly.


title:
Morphological Constraints for Phrase Pivot Statistical Machine
  Translation

abstract:
  The lack of parallel data for many language pairs is an important challenge
to statistical machine translation (SMT). One common solution is to pivot
through a third language for which there exist parallel corpora with the source
and target languages. Although pivoting is a robust technique, it introduces
some low quality translations especially when a poor morphology language is
used as the pivot between rich morphology languages. In this paper, we examine
the use of synchronous morphology constraint features to improve the quality of
phrase pivot SMT. We compare hand-crafted constraints to those learned from
limited parallel data between source and target languages. The learned
morphology constraints are based on projected align- ments between the source
and target phrases in the pivot phrase table. We show positive results on
Hebrew-Arabic SMT (pivoting on English). We get 1.5 BLEU points over a phrase
pivot baseline and 0.8 BLEU points over a system combination baseline with a
direct model built from parallel data.


title: Isometric embeddings of snowflakes into finite-dimensional Banach spaces

abstract:
  We consider a general notion of snowflake of a metric space by composing the
distance by a nontrivial concave function.
  We prove that a snowflake of a metric space $X$ isometrically embeds into
some finite-dimensional normed space if and only if $X$ is finite. In the case
of power functions we give a uniform bound on the cardinality of $X$ depending
only on the power exponent and the dimension of the vector space.


title: A method of constructive quantum mechanics of remarkable hidden beauty

abstract: A viewpoint-article comment on asymptotic iteration method.


title: The origin of the enhanced metallicity of satellite galaxies

abstract:
  Observations of galaxies in the local Universe have shown that both the
ionized gas and the stars of satellites are more metal-rich than of equally
massive centrals. To gain insight into the connection between this metallicity
enhancement and other differences between centrals and satellites, such as
their star formation rates, gas content, and growth history, we study the
metallicities of >3600 galaxies with M_star > 10^10 M_sun in the cosmological
hydrodynamical EAGLE 100 Mpc `Reference' simulation, including ~1500 in the
vicinity of galaxy groups and clusters (M_200 >= 10^13 M_sun). The simulation
predicts excess gas and stellar metallicities in satellites consistent with
observations, except for stellar metallicities at M_star <~ 10^10.2 M_sun where
the predicted excess is smaller than observed. The exact magnitude of the
effect depends on galaxy selection, aperture, and on whether the metallicity is
weighted by stellar mass or luminosity. The stellar metallicity excess in
clusters is also sensitive to the efficiency scaling of star formation
feedback. We identify stripping of low-metallicity gas from the galaxy
outskirts, as well as suppression of metal-poor inflows towards the galaxy
centre, as key drivers of the enhancement of gas metallicity. Stellar
metallicities in satellites are higher than in the field as a direct
consequence of the more metal-rich star forming gas, whereas stripping of stars
and suppressed stellar mass growth, as well as differences in accreted vs.
in-situ star formation between satellites and the field, are of secondary
importance.


title:
Transport properties of photonic topological insulators based on
  microring resonator array

abstract:
  An array of ring resonators specifically designed can perform as a
topological insulator. We conduct simulations using both Tight-Binding Model
(TBM) and Transfer Matrix Method (TMM) to analyze the transport properties of
such optical structure, verifying the presence of robust topological edge
states which is immune to disorder and defect. We have also made a comparison
between these two methods, of which results suggesting that TBM is only
applicable under weakly-coupling condition while TMM is more rigorous. Finally
we compared the structure with common microring array and coupled resonator
optical waveguide (CROW) to demonstrate that it has desired transmission
properties with wide and flat spectral response.


title: Mapping the Chemical Potential Landscape of a Triple Quantum Dot

abstract:
  We investigate the non-equilibrium charge dynamics of a triple quantum dot
and demonstrate how electron transport through these systems can give rise to
non-trivial tunnelling paths. Using a real-time charge sensing method we
establish tunnelling pathways taken by particular electrons under well-defined
electrostatic configurations. We show how these measurements map to the
chemical potentials for different charge states across the system. We use a
modified Hubbard Hamiltonian to describe the system dynamics and show that it
reproduces all experimental observations.


title: Properties of the false vacuum as the quantum unstable state

abstract:
  We analyze properties of unstable vacuum states from the point of view of the
quantum theory. In the literature one can find some suggestions that some of
false (unstable) vacuum states may survive up to times when their survival
probability has a non-exponential form. At asymptotically late times the
survival probability as a function of time $t$ has an inverse power--like form.
We show that at this time region the energy of the false vacuum states tends to
the energy of the true vacuum state as $1/t^{2}$ for $t \to \infty$. This means
that the energy density in the unstable vacuum state should have analogous
properties and hence the cosmological constant $\Lambda = \Lambda (t)$ too. The
conclusion is that $\Lambda$ in the Universe with the unstable vacuum should
have a form of the sum of the "bare" cosmological constant and of the term of a
type $1/t^{2}$: $\Lambda(t) \equiv \Lambda_{bare} + d/ t^{2}$ (where
$\Lambda_{bare}$ is the cosmological constant for the Universe with the true
vacuum).


title:
Spin structures of textured and isotropic Nd-Fe-B-based nanocomposites:
  Evidence for correlated crystallographic and spin texture

abstract:
  We report the results of a comparative study of the magnetic microstructure
of textured and isotropic
$\mathrm{Nd}_2\mathrm{Fe}_{14}\mathrm{B}/\alpha$-$\mathrm{Fe}$ nanocomposites
using magnetometry, transmission electron microscopy, synchrotron x-ray
diffraction, and, in particular, magnetic small-angle neutron scattering
(SANS). Analysis of the magnetic neutron data of the textured specimen and
computation of the correlation function of the spin misalignment SANS cross
section suggests the existence of inhomogeneously magnetized regions on an
intraparticle nanometer length scale, about $40-50 \, \mathrm{nm}$ in the
remanent state. Possible origins for this spin disorder are discussed: it may
originate in thin grain-boundary layers (where the materials parameters are
different than in the $\mathrm{Nd}_2\mathrm{Fe}_{14}\mathrm{B}$ grains), or it
may reflect the presence of crystal defects (introduced via hot pressing), or
the dispersion in the orientation distribution of the magnetocrystalline
anisotropy axes of the $\mathrm{Nd}_2\mathrm{Fe}_{14}\mathrm{B}$ grains. X-ray
powder diffraction data reveal a crystallographic texture in the direction
perpendicular to the pressing direction -- a finding which might be related to
the presence of a texture in the magnetization distribution, as inferred from
the magnetic SANS data.


title: Thermal analysis of Josephson junctions array in cryocooler

abstract:
  Complex cryogenics is still a strong limitation to the spread of quantum
voltage standards and cryogen-free operation is then particularly interesting
for Josephson standards. The main difficulties in He-free refrigeration are
related to chip thermalization. We tested different solutions and interface
materials between the chip and the cooling surface, to improve thermal
conduction. Some junctions were chosen as elements to dissipate electrical
power, while some others were operated as on-chip temperature sensors. Indium
foil between chip and Cu support was demonstrated to provide a good thermal
interface suitable for programmable voltage standard operation. However,
thermal conduction can be further increased by thermal contacting the chip at
the top. Finally, general physical constraints in vacuum thermal contacts are
analyzed in terms of known properties of thermal interfaces at cryogenics
temperatures.


title:
Libraries' Metadata as Data in the Era of the Semantic Web: Modeling a
  Repository of Master Theses and PhD Dissertations for the Web of Data

abstract:
  This study argues that metadata of library catalogs can stand autonomously,
providing valuable information detached from the resources they point to and,
therefore, could be used as data in the context of the Semantic Web. We present
an analysis of this perception followed by an implementation proposal for a
Master's thesis and PhD dissertation repository. The analysis builds on the
flexibility of the Resource Description Framework (RDF) and takes into account
the Functional Requirements for Bibliographic Records (FRBR) and Functional
Requirements for Authority Data (FRAD) in order to reveal the latent academic
network by linking its entities to a meaningful and computationally processable
set. Current library catalogs retrieve documents to find answers, whereas in
our approach catalogs can provide answers that could not be found in any
specific document.


title: New CMB constraints for Abelian Higgs cosmic strings

abstract:
  We present cosmic microwave background (CMB) power spectra from recent
numerical simulations of cosmic strings in the Abelian Higgs model and compare
them to CMB power spectra measured by Planck. We obtain revised constraints on
the cosmic string tension parameter $G\mu$. For example, in the $\Lambda$CDM
model with the addition of strings and no primordial tensor perturbations, we
find $G\mu < 2.0 \times 10^{-7}$ at 95% confidence, about 20% lower than the
value obtained from previous simulations, which had 1/64 of the spatial volume.
We investigate the source of the difference, showing that the main cause is an
improved treatment of the string evolution across the radiation-matter
transition. The increased computational volume also makes possible to simulate
fully the physical equations of motion, in which the string cores shrink in
comoving coordinates. This, and the larger dynamic range, changes the amplitude
of the power spectra by only about 10%, demonstrating that field theory
simulations of cosmic strings have now reached the required dynamic range for
CMB calculations.


title:
M2M Traffic via Random Access Satellite links: Interactions between
  Transport and MAC Layers

abstract:
  Machine-to-machine services are witnessing an unprecedented diffusion, which
is expected to result in an ever-increasing data traffic load. In this context,
satellite technology is playing a pivotal role, since it enables a widespread
provisioning of machine-to-machine services. In particular, oil industry,
maritime communications, as well as remote monitoring are sectors where the use
of satellite communications is expected to dramatically explode within the next
few years. In the light of this sudden increase of machine-to-machine data
transported over satellite, a more thorough understanding of machine-to-machine
service implementation over satellite is required, especially focusing on the
interaction between transport and MAC layers of the protocol stack. Starting
from these observations, this paper thoroughly analyses the interaction between
TCP and the Contention Resolution Diversity Slotted Aloha access scheme defined
in the DVB-RCS2 standard, assuming the use of an MQTT-like protocol to
distribute machine-to-machine services. A novel TCP model is developed and
validated through extensive simulation campaigns, which also shed important
lights on the design choices enabling the efficient transport of
machine-to-machine data via satellite.


title:
Halo Histories vs. Galaxy Properties at z=0, I: The Quenching of Star
  Formation

abstract:
  We test whether halo age and galaxy age are correlated at fixed halo and
galaxy mass. The formation histories, and thus ages, of dark matter halos
correlate with their large-scale density $\rho$, an effect known as assembly
bias. We test whether this correlation extends to galaxies by measuring the
dependence of galaxy stellar age on $\rho$. To clarify the comparison between
theory and observation, and to remove the strong environmental effects on
satellites, we use galaxy group catalogs to identify central galaxies and
measure their quenched fraction, $f_Q$, as a function of large-scale
environment. Models that match halo age to central galaxy age predict a strong
positive correlation between $f_Q$ and $\rho$. However, we show that the
amplitude of this effect depends on the definition of halo age: assembly bias
is significantly reduced when removing the effects of splashback halos---those
halos that are central but have passed through a larger halo or experienced
strong tidal encounters. Defining age using halo mass at its peak value rather
than current mass removes these effects. In SDSS data, at M$_{\rm gal}\gtrsim
10^{10.0}$ M_sol/h$^2$, there is a $\sim 5\%$ increase in $f_Q$ from low to
high densities, which is in agreement with predictions of dark matter halos
using peak halo mass. At lower stellar mass there is little to no correlation
of $f_Q$ with $\rho$. For these galaxies, age-matching is inconsistent with the
data across the wide range the halo formation metrics that we tested. This
implies that halo formation history has a small but statistically significant
impact on quenching of star formation at high masses, while the quenching
process in low-mass central galaxies is uncorrelated with halo formation
history.


title: Spin decoherence of magnetic atoms on surfaces

abstract:
  We review the problem of spin decoherence of magnetic atoms deposited on a
surface. Recent breakthroughs in scanning tunnelling microscopy (STM) make it
possible to probe the spin dynamics of individual atoms, either isolated or
integrated in nanoengineered spin structures. Transport pump and probe
techniques with spin polarized tips permit measuring the spin relaxation time
$T_1$, while novel demonstration of electrically driven STM single spin
resonance has provided a direct measurement of the spin decoherence time $T_2$
of an individual magnetic adatom. Here we address the problem of spin
decoherence from the theoretical point of view. First we provide a short
general overview of decoherence in open quantum systems and we discuss with
some detail ambiguities that arise in the case of degenerate spectra, relevant
for magnetic atoms. Second, we address the physical mechanisms that allows
probing the spin coherence of magnetic atoms on surfaces. Third, we discuss the
main spin decoherence mechanisms at work on a surface, most notably, Kondo
interaction, but also spin-phonon coupling and dephasing by Johnson noise.
Finally, we propose some schemes to engineer spin decoherence.


title:
NLO QCD Predictions for off-shell $t \bar t$ and $t \bar t H$ Production
  and Decay at a Linear Collider

abstract:
  We present predictions for $t \bar t$ and $t \bar t H$ production and decay
at future lepton colliders including non-resonant and interference
contributions up to next-to-leading order (NLO) in perturbative QCD. The
obtained precision predictions are necessary for a future precise determination
of the top-quark Yukawa coupling, and allow for top-quark phenomenology in the
continuum at an unprecedented level of accuracy. Simulations are performed with
the automated NLO Monte-Carlo framework WHIZARD interfaced to the OpenLoops
matrix element generator.


title:
NLS breathers, rogue waves, and solutions of the Lyapunov equation for
  Jordan blocks

abstract:
  The infinite families of Peregrine, Akhmediev and Kuznetsov-Ma breather
solutions of the focusing Nonlinear Schroedinger (NLS) equation are obtained
via a matrix version of the Darboux transformation, with a spectral matrix of
the form of a Jordan block. The structure of these solutions is essentially
determined by the corresponding solution of the Lyapunov equation. In
particular, regularity follows from properties of the Lyapunov equation.


title:
Improved orbits and parallaxes for eight visual binaries with
  unrealistic previous masses using the Hipparcos parallax

abstract:
  Improved orbits are presented for the visual binaries WDS 02366+1227, WDS
02434-6643, WDS 03244-1539, WDS 08507+1800, WDS 09128-6055, WDS 11532-1540, WDS
17375+2419, and WDS 22408-0333. The latest orbits for these binaries were
demonstrating a great inconsistency between the systemic mass obtained through
Kepler's Third Law and that calculated as a sum of their components' mass
through standard mass-luminosity and mass-spectrum relationships. Our
improvement allowed us to obtain consistent systemic masses for WDS 02434-6643
and WDS 09128-6055 without a need for changing the Hipparcos parallax. For the
remaining 6 pairs, we suggest the use of their dynamical parallax as a reliable
distance estimate unless more precise parallax is reported. Astrophysical and
dynamical properties of individual objects are discussed.


title: Unavoidable trees in tournaments

abstract:
  An oriented tree $T$ on $n$ vertices is unavoidable if every tournament on
$n$ vertices contains a copy of $T$. In this paper we give a sufficient
condition for $T$ to be unavoidable, and use this to prove that almost all
labelled oriented trees are unavoidable, verifying a conjecture of Bender and
Wormald. We additionally prove that every tournament on $n + o(n)$ vertices
contains a copy of every oriented tree $T$ on $n$ vertices with polylogarithmic
maximum degree, improving a result of K\"uhn, Mycroft and Osthus.


title: A Study on Clique Invariants of Jaco-type Graphs

abstract:
  The first study related to this paper was on the notion of primitive holes.
This paper reports on research in respect of clique parameters and related
properties thereof within Jaco-type graphs.


title: A Study on the Quadratic Jaco Graph

abstract:
  In this paper we introduce the quadratic Jaco graph. The characteristics,
properties and some graph invariants of quadratic Jaco graphs are discussed.
The observation that quadratic Jaco graphs are well-defined in respect of
complete graphs and bridges led to the notion of braided complete graphs.


title:
FALCON: Feature Driven Selective Classification for Energy-Efficient
  Image Recognition

abstract:
  Machine-learning algorithms have shown outstanding image recognition or
classification performance for computer vision applications. However, the
compute and energy requirement for implementing such classifier models for
large-scale problems is quite high. In this paper, we propose Feature Driven
Selective Classification (FALCON) inspired by the biological visual attention
mechanism in the brain to optimize the energy-efficiency of machine-learning
classifiers. We use the consensus in the characteristic features
(color/texture) across images in a dataset to decompose the original
classification problem and construct a tree of classifiers (nodes) with a
generic-to-specific transition in the classification hierarchy. The initial
nodes of the tree separate the instances based on feature information and
selectively enable the latter nodes to perform object specific classification.
The proposed methodology allows selective activation of only those branches and
nodes of the classification tree that are relevant to the input while keeping
the remaining nodes idle. Additionally, we propose a programmable and scalable
Neuromorphic Engine (NeuE) that utilizes arrays of specialized neural
computational elements to execute the FALCON based classifier models for
diverse datasets. The structure of FALCON facilitates the reuse of nodes while
scaling up from small classification problems to larger ones thus allowing us
to construct classifier implementations that are significantly more efficient.
We evaluate our approach for a 12-object classification task on the Caltech101
dataset and 10-object task on CIFAR-10 dataset by constructing FALCON models on
the NeuE platform in 45nm technology. Our results demonstrate significant
improvement in energy-efficiency and training time for minimal loss in output
quality.


title:
New Results on Massive 3-Loop Wilson Coefficients in Deep-Inelastic
  Scattering

abstract:
  We present recent results on newly calculated 2- and 3-loop contributions to
the heavy quark parts of the structure functions in deep-inelastic scattering
due to charm and bottom.


title: Dynamical Galois groups of trinomials and Odoni's conjecture

abstract:
  We prove Odoni's conjecture in all prime degrees; namely, we prove that for
every positive prime $p$, there exists a degree $p$ polynomial
$\varphi\in\mathbb{Z}[x]$ with surjective arboreal Galois representation. We
also show that Vojta's conjecture implies the existence of such a polynomial in
many degrees $d$ which are not prime.


title:
Determination of the $\boldsymbol{\eta ^3{\rm He}}$ threshold structure
  from the low energy $\boldsymbol{pd \to \eta ^3{\rm He}}$ reaction

abstract:
  We analyze the data on cross sections and asymmetries for the $pd (dp) \to
\eta ^3{\rm He}$ reaction close to threshold and look for bound states of the
$\eta ^3 {\rm He}$ system. Rather than parameterizing the scattering matrix, as
is usually done, we develop a framework in which the $\eta ^3 {\rm He}$ optical
potential is the key ingredient, and its strength, together with some
production parameters, are fitted to the available experimental data. The
relationship of the scattering matrix to the optical potential is established
using the Bethe-Salpeter equation and the $\eta ^3 {\rm He}$ loop function
incorporates the range of the interaction given by the empirical $^3 {\rm He}$
density. We find a local Breit Wigner form of the $\eta^3$He amplitude $T$
below threshold with a clear peak in $|T|^2$, which corresponds to an $\eta^3
{\rm He}$ binding of about 0.3 MeV and a width of about 3 MeV. By fitting the
potential we can also evaluate the $\eta ^3 {\rm He}$ scattering length,
including its sign, thus resolving the ambiguity in the former analyses.


title:
Efficient inference for genetic association studies with multiple
  outcomes

abstract:
  Combined inference for heterogeneous high-dimensional data is critical in
modern biology, where clinical and various kinds of molecular data may be
available from a single study. Classical genetic association studies regress a
single clinical outcome on many genetic variants one by one, but there is an
increasing demand for joint analysis of many molecular outcomes and genetic
variants in order to unravel functional interactions. Unfortunately, most
existing approaches to joint modelling are either too simplistic to be powerful
or are impracticable for computational reasons. Inspired by Richardson et al.
(2010, Bayesian Statistics 9), we consider a sparse multivariate regression
model that allows simultaneous selection of predictors and associated
responses. As Markov chain Monte Carlo (MCMC) inference on such models can be
prohibitively slow when the number of genetic variants exceeds a few thousand,
we propose a variational inference approach which produces posterior
information very close to that of MCMC inference, at a much reduced
computational cost. Extensive numerical experiments show that our approach
outperforms popular variable selection methods and tailored Bayesian
procedures, dealing within hours with problems involving hundreds of thousands
of genetic variants and tens to hundreds of clinical or molecular outcomes.


title: On $r$-uniform linear hypergraphs with no Berge-$K_{2,t}$

abstract:
  Let $\mathcal{F}$ be an $r$-uniform hypergraph and $G$ be a multigraph. The
hypergraph $\mathcal{F}$ is a Berge-$G$ if there is a bijection $f: E(G)
\rightarrow E( \mathcal{F} )$ such that $e \subseteq f(e)$ for each $e \in
E(G)$. Given a family of multigraphs $\mathcal{G}$, a hypergraph $\mathcal{H}$
is said to be $\mathcal{G}$-free if for each $G \in \mathcal{G}$, $\mathcal{H}$
does not contain a subhypergraph that is isomorphic to a Berge-$G$. We prove
bounds on the maximum number of edges in an $r$-uniform linear hypergraph that
is $K_{2,t}$-free. We also determine an asymptotic formula for the maximum
number of edges in a linear 3-uniform 3-partite hypergraph that is $\{C_3 ,
K_{2,3} \}$-free.


title: On the existence of accretion-driven bursts in massive star formation

abstract:
  Accretion-driven luminosity outbursts are a vivid manifestation of variable
mass accretion onto protostars. They are known as the so-called FU Orionis
phenomenon in the context of low-mass protostars. More recently, this process
has been found in models of primordial star formation. Using numerical
radiation hydrodynamics simulations, we stress that present-day forming massive
stars also experience variable accretion and show that this process is
accompanied by luminous outbursts induced by the episodic accretion of gaseous
clumps falling from the circumstellar disk onto the protostar. Consequently,
the process of accretion-induced luminous flares is also conceivable in the
high-mass regime of star formation and we propose to regard this phenomenon as
a general mechanism that can affect protostars regardless of their mass and/or
the chemical properties of the parent environment in which they form. In
addition to the commonness of accretion-driven outbursts in the star formation
machinery, we conjecture that luminous flares from regions hosting forming
high-mass star may be an observational implication of the fragmentation of
their accretion disks.


title: Type-II Leptogenesis

abstract:
  I will talk on our new theory on baryogenesis through type-II leptogenesis
which is different from the well-known type-I leptogenesis. I will comment on
the Jarlskog phases, $\delta_{\rm CKM}$ and $\delta_{\rm PMNS}$, in the CKM and
PMNS matrices. In the type-II leptogenesis, the PMNS phase is used for
Sakharov's condition on the global quantum number generation in the Universe.
For this to be effective, the SU(2)$\times$U(1) gauge symmetry must be broken
during the leptogenesis epoch.


title: Mirror mesons at the Large Hadron Collider (LHC)

abstract:
  The existence of mirror partners of Standard-Model fermions offers a viable
alternative to a fundamental BEH mechanism, with the coupling corresponding to
the gauged mirror generation symmetry becoming naturally strong at energies
around 1 TeV. The resulting non-perturbative processes produce dynamical
katoptron masses which might range from 0.1 to 1.15 TeV in a way circumventing
usual problems with the S parameter. Moreover, they create mirror mesons
belonging in two main groups, with masses differing from each other
approximately by a factor of six and which might range approximately from 0.1
to 2.8 TeV. Since the corresponding phenomenology expected at hadron colliders
is particularly rich, some interesting mirror-meson cross-sections are
presented, something that might also lead to a deeper understanding of the
underlying mirror fermion structure. Among other findings, results in principle
compatible with indications from LHC concerning decays of new particles to two
photons are analyzed.


title: From Hopf-Lax formula to optimal weak transfer plan

abstract:
  We study the properties of Hopf-Lax formula restricted to convex functions
and characterize the optimal transfer plan for weak transport problem.


title:
Regularity of hyperbolic magnetic Schr\"odinger equation with
  oscillating coefficients

abstract:
  This paper mainly discuss the regularity behavior of the hyperbolic magnetic
Schroedinger equation with singular coefficients near the origin. We apply the
techniques from the microlocal analysis to explore the upper bound of loss of
regularity. Furthermore, in order to demonstrate the optimality of the result,
a delicate counterexample with periodic coefficients will be constructed to
show the lower bound of loss of regularity by the application of harmonic
analysis and instability arguments.


title:
Role of the radiation-reaction electric field in the optical response of
  two-dimensional crystals

abstract:
  A classical theory of a radiating two-dimensional crystal is proposed and an
expression for the radiative-reaction electric field is derived. This field
plays an essential role in connecting the microscopic electromagnetic fields
acting on each dipole of the crystal to the macroscopic one, via the boundary
conditions for the system. The expression of the radiative-reaction electric
field coincides with the macroscopic electric field radiating from the crystal
and, summed to the incident electric field, generates the total macroscopic
electric field.


title: Deuteron structure in the deep inelastic regime

abstract:
  We study nuclear effects on the deuteron in the deep inelastic regime using
the newest available data analyzing their $Q^2$ dependence. We conclude that
precise EMC ratios for large $Q^2$ (> 30, GeV$^2$) cannot be obtained without
considering these nuclear effects. For this purpose we use a scheme which
parametrizes these effects in a simple manner and compare our results with
other recent proposals.


title:
Acoustic intensity, energy-density and diffuseness estimation in a
  directionally-constrained region

abstract:
  This work presents a method for estimation of the acoustic intensity, the
energy density and the associated sound field diffuseness around the origin,
when the sound field is weighted with a spatial filter. The method permits
energetic DOA estimation and sound field characterization focused in a specific
angular region determined by the beam pattern of the spatial filter. The
formulation of the estimators is presented and their behavior is analyzed for
the fundamental cases useful in parametric sound field models of a single plane
wave, a uniform diffuse field and a mixture of the two.


title:
Effect of surfactant concentration and interfacial slip on the flow past
  a viscous drop at low surface P\'eclet number

abstract:
  The motion of a viscous drop is investigated when the interface is fully
covered with a stagnant layer of surfactant in an arbitrary unsteady Stokes
flow for the low surface P\'eclet number limit. The effect of the interfacial
slip coefficient on the behavior of the flow field is also considered. The
hydrodynamic problem is solved by the solenoidal decomposition method and the
drag force is computed in terms of Faxen's laws using a perturbation ansatz in
powers of the surface P\'eclet number. The analytical expressions for the
migration velocity of the drop are also obtained in powers of the surface
P\'eclet number. Further instances corresponding to a given ambient flow as
uniform flow, Couette flow, Poiseuille flow are analyzed. Moreover, it is
observed that, a surfactant-induced cross-stream migration of the drop occur
towards the centre-line in both Couette flow and Poiseuille flow cases. The
variation of the drag force and migration velocity is computed for different
parameters such as P\'eclet number, Marangoni number etc.


title: Dark matter as seen from the physical point of view

abstract:
  It is shown that the Newton's law of universal gravitation can be derived
from first submicroscopic principles inherent in the very nature of real space
that is constituted as a tessellattice of primary topological balls. The
submicroscopic concept determines the notion of mass in the tessellattice and
introduces excitations of space, which appear at the motion of particles (mass
particles are determined as local deformations of the tessellattice). These
excitations are associated with carriers of the field of inertia. In the
universe the gravitation is induced by standing inerton waves of mass objects,
which oscillate around the objects with the speed of light. An overlapping of
these standing inerton waves generates an elastic interaction between masses
bringing them to a formation of clusters in which masses are characterised by
both the Newtonian and elastic interaction. It is this elastic interaction that
cancels the necessity of introduction of mystical dark matter. At the same
time, inertons, carriers of inert properties of objects, can be treated as an
analogous of hypothetic weakly interacting massive particles (WIMP) or axions,
which some astronomers try to associate with dark matter particles.


title:
Nonvolatile Multi-level Memory and Boolean Logic Gates Based on a Single
  Memtranstor

abstract:
  Memtranstor that correlates charge and magnetic flux via nonlinear
magnetoelectric effects has a great potential in developing next-generation
nonvolatile devices. In addition to multi-level nonvolatile memory, we
demonstrate here that nonvolatile logic gates such as NOR and NAND can be
implemented in a single memtranstor made of the Ni/PMN-PT/Ni heterostructure.
After applying two sequent voltage pulses (X1, X2) as the logic inputs on the
memtranstor, the output magnetoelectric voltage can be positive high (logic
"1"), positive low (logic "0"), or negative (logic "0"), depending on the
levels of X1 and X2. The underlying physical mechanism is related to the
complete or partial reversal of ferroelectric polarization controlled by
inputting selective voltage pulses, which determines the magnitude and sign of
the magnetoelectric voltage coefficient. The combined functions of both memory
and logic could enable the memtranstor as a promising candidate for future
computing systems beyond von Neumann architecture.


title: PDEs and hypercomplex analytic functions

abstract:
  Hypercomplex numbers are unital algebras over the real numbers. We offer a
short demonstration of the practical value of hypercomplex analytic functions
in the field of partial differential equations.


title:
Well-posedness for the Cauchy problem of spatially weighted dissipative
  equation

abstract:
  This paper mainly investigates the Cauchy problem of the spatially weighted
dissipative equation with initial data in the weighted Lebesgue space. A
generalized Hankel Transform is introduced to derive the analytical solution
and a special Young's Inequality has been applied to prove the space-time
estimates for this type of equation.


title:
Active Canny: Edge Detection and Recovery with Open Active Contour
  Models

abstract:
  We introduce an edge detection and recovery framework based on open active
contour models (snakelets). This is motivated by the noisy or broken edges
output by standard edge detection algorithms, like Canny. The idea is to
utilize the local continuity and smoothness cues provided by strong edges and
grow them to recover the missing edges. This way, the strong edges are used to
recover weak or missing edges by considering the local edge structures, instead
of blindly linking them if gradient magnitudes are above some threshold. We
initialize short snakelets on the gradient magnitudes or binary edges
automatically and then deform and grow them under the influence of gradient
vector flow. The output snakelets are able to recover most of the breaks or
weak edges, and they provide a smooth edge representation of the image; they
can also be used for higher level analysis, like contour segmentation.


title:
Characterization of two distant double-slits by chaotic light
  second-order interference

abstract:
  We present the experimental characterization of two distant double-slit masks
illuminated by chaotic light, in the absence of first-order imaging and
interference. The scheme exploits second-order interference of light
propagating through two indistinguishable pairs of {\it disjoint} optical paths
passing through the masks of interest. The proposed technique leads to a deeper
understanding of biphoton interference and coherence, and opens the way to the
development of novel schemes for retrieving information on the relative
position and the spatial structure of distant objects, which is of interest in
remote sensing, biomedical imaging, as well as monitoring of laser ablation,
when first-order imaging and interference are not feasible.


title: The Unusual Nature of Confined Modes in a Chiral System

abstract:
  Nonreciprocity of spin wave propagation is a well-known consequence of
antisymmetric exchange contributions possible in magnetic spin systems that
lack inversion symmetry. In this case, it is possible for the energy of a state
to depend on the sign of its momentum as {\omega}(k) ${\neq}$ {\omega}(-k). We
discuss here the consequences of this nonreciprocity on counterpropagating
travelling spin wave states. In a confined geometry we find states with
well-defined nodes but with amplitudes that are modulated such that inversion
symmetry of the mode profile is lost. This feature leads to the suggestion that
additional features may become visible in, for example, ferromagnetic resonance
studies of ferromagnetic micro-elements with DMI, allowing a quantification of
the amplitude and direction of the DMI. Moreover, this interference between
nonreciprocal modes forms the basis for a generalized concept of mode
confinement.


title: Particle-in-cell simulation study of a lower-hybrid shock

abstract:
  The expansion of a magnetized high-pressure plasma into a low-pressure
ambient medium is examined with particle-in-cell (PIC) simulations. The
magnetic field points perpendicularly to the plasma's expansion direction and
binary collisions between particles are absent. The expanding plasma steepens
into a quasi-electrostatic shock that is sustained by the lower-hybrid (LH)
wave. The ambipolar electric field points in the expansion direction and it
induces together with the background magnetic field a fast E cross B drift of
electrons. The drifting electrons modify the background magnetic field,
resulting in its pile-up by the LH shock. The magnetic pressure gradient force
accelerates the ambient ions ahead of the LH shock, reducing the relative
velocity between the ambient plasma and the LH shock to about the phase speed
of the shocked LH wave, transforming the LH shock into a nonlinear LH wave. The
oscillations of the electrostatic potential have a larger amplitude and
wavelength in the magnetized plasma than in an unmagnetized one with otherwise
identical conditions. The energy loss to the drifting electrons leads to a
noticable slowdown of the LH shock compared to that in an unmagnetized plasma.


title:
Coincidence detection of spatially correlated photon pairs with a
  monolithic time-resolving detector array

abstract:
  We demonstrate coincidence measurements of spatially entangled photons by
means of a novel type of multi-pixel based detection array. The adopted sensor
is a fully digital 8$\times$16 silicon photomultiplier array allowing not only
photon counting but also per-pixel time stamping of the arrived photons with a
resolution of 65 ps. Together with a frame rate of 500 kfps, this property
exceeds the capabilities of conventional charge-coupled device cameras which
have become of growing interest for the detection of transversely correlated
photon pairs. The sensor is used to measure a second-order correlation function
for various non-collinear configurations of entangled photons generated by
spontaneous parametric down-conversion. The experimental results are compared
to theory.


title:
Physical restrictions on the choice of electromagnetic gauge and their
  practical consequences

abstract:
  It is shown that electromagnetic potentials convey physical information
beyond that supplied by electric and magnetic fields alone, and are thus more
fundamental. Observable physical properties can impose conditions on the
selection of electromagnetic gauge (i.e. sets of potentials) that are explicit
and restrictive. This is true both classically and quantum mechanically. The
implication that the choice of gauge carries physical information is confirmed
by exhibiting a set of potentials that describes fields correctly, but that
violates physical constraints. The basic conclusions are that physical
requirements place limits on acceptable gauges; and that potentials are more
fundamental than fields in both classical and quantum physics, representing a
major generalization of the quantum-only Aharonov-Bohm effect. These important
properties are obscured if the dipole approximation is employed. The properties
demonstrated here relate directly to conditions that exist in strong-field
laser applications.


title:
ALMA reveals optically thin, highly excited CO gas in the jet-driven
  winds of the galaxy IC5063

abstract:
  Using CO (4-3) and (2-1) Atacama Large Millimeter Array (ALMA) data, we prove
that the molecular gas in the jet-driven winds of the galaxy IC5063 is more
highly excited than the rest of the molecular gas in the disk of the same
galaxy. On average, the CO(4-3)/CO(2-1) flux ratio is 1 for the disk and 5 for
the jet accelerated or impacted gas. Spatially-resolved maps reveal that in
regions associated with winds, the CO(4-3)/CO(2-1) flux ratio significantly
exceeds the upper limit of 4 for optically thick gas. It frequently takes
values between 5 and 11, and it occasionally further approaches the upper limit
of 16 for optically thin gas. Excitation temperatures of 30-100 K are common
for the molecules in these regions. If all of the outflowing molecular gas is
optically thin, at 30-50 K, then its mass is 2*10^6 M_sun. This lower mass
limit is an order of magnitude below the mass derived from the CO(2-1) flux in
the case of optically thick gas. Molecular winds can thus be less massive, but
more easily detectable at high z than they were previously thought to be.


title:
Orthorhombic boron oxide under pressure: in situ study by X-ray
  diffraction and Raman scattering

abstract:
  High-pressure phase of boron oxide, orthorhombic \b{eta}-B2O3, has been
studied in situ by synchrotron X-ray diffraction to 22 GPa and Raman scattering
to 46 GPa at room temperature. The bulk modulus of \b{eta}-B2O3 has been found
to be 169(3) GPa that is in good agreement with our ab initio calculations.
Raman and IR spectra of \b{eta}-B2O3 have been measured at ambient pressure,
all experimentally observed bands have been attributed to the theoretically
calculated ones, and the mode assignment has been performed. Based on the data
on Raman shift as a function of pressure, combined with equation-of-state data,
the Gr\"uneisen parameters of all experimentally observed Raman bands have been
calculated. \b{eta}-B2O3 enriched by 10B isotope has been synthesized, and the
effect of boron isotopic substitution on Raman spectra has been studied.


title:
A Bayesian Lower Bound for Parameter Estimation of Poisson Data
  Including Multiple Changes (extended)

abstract:
  This paper derives lower bounds for the mean square errors of parameter
estimators in the case of Poisson distributed data subjected to multiple abrupt
changes. Since both change locations (discrete parameters) and parameters of
the Poisson distribution (continuous parameters) are unknown, it is appropriate
to consider a mixed Cramer-Rao/Weiss-Weinstein bound for which we derive
closed-form expressions and illustrate its tightness by numerical simulations.


title:
Estimating distances from parallaxes. II. Performance of Bayesian
  distance estimators on a Gaia-like catalogue

abstract:
  Estimating a distance by inverting a parallax is only valid in the absence of
noise. As most stars in the Gaia catalogue will have non-negligible fractional
parallax errors, we must treat distance estimation as a constrained inference
problem. Here we investigate the performance of various priors for estimating
distances, using a simulated Gaia catalogue of one billion stars. We use three
minimalist, isotropic priors, as well an anisotropic prior derived from the
observability of stars in a Milky Way model. The two priors that assume a
uniform distribution of stars--either in distance or in space density---give
poor results: The root mean square fractional distance error, f_RMS, grows far
in excess of 100% once the fractional parallax error, f_true, is larger than
0.1. A prior assuming an exponentially decreasing space density with increasing
distance performs well once its single scale length parameter has been set to
an appropriate value: f_RMS is roughly equal to f_true for f_true < 0.4, yet
does not increase further as f_true increases up to to 1.0. The Milky Way prior
performs well except towards the Galactic centre, due to a mismatch with the
(simulated) data. Such mismatches will be inevitable (and remain unknown) in
real applications, and can produce large errors. We therefore suggest to adopt
the simpler exponentially decreasing space density prior, which is also less
time-consuming to compute. Including Gaia photometry improves the distance
estimation significantly for both the Milky Way and exponentially decreasing
space density prior, yet doing so requires additional assumptions about the
physical nature of stars.


title: Detecting Relativistic X-ray Jets in High-Redshift Quasars

abstract:
  We analyze Chandra X-ray images of a sample of 11 quasars that are known to
contain kiloparsec scale radio jets. The sample consists of five high-redshift
(z >= 3.6) flat-spectrum radio quasars, and six intermediate redshift (2.1 < z
< 2.9) quasars. The dataset includes four sources with integrated steep radio
spectra and seven with flat radio spectra. A total of 25 radio jet features are
present in this sample. We apply a Bayesian multi-scale image reconstruction
method to detect and measure the X-ray emission from the jets. We compute
deviations from a baseline model that does not include the jet, and compare
observed X-ray images with those computed with simulated images where no jet
features exist. This allows us to compute p-value upper bounds on the
significance that an X- ray jet is detected in a pre-determined region of
interest. We detected 12 of the features unambiguously, and an additional 6
marginally. We also find residual emission in the cores of 3 quasars and in the
background of 1 quasar that suggest the existence of unresolved X-ray jets. The
dependence of the X-ray to radio luminosity ratio on redshift is a potential
diagnostic of the emission mechanism, since the inverse Compton scattering of
cosmic microwave background photons (IC/CMB) is thought to be redshift
dependent, whereas in synchrotron models no clear redshift dependence is
expected. We find that the high-redshift jets have X-ray to radio flux ratios
that are marginally inconsistent with those from lower redshifts, suggesting
that either the X-ray emissions is due to the IC/CMB rather than the
synchrotron process, or that high redshift jets are qualitatively different.


title: Multi-Label Learning with Provable Guarantee

abstract:
  Here we study the problem of learning labels for large text corpora where
each text can be assigned a variable number of labels. The problem might seem
trivial when the label dimensionality is small and can be easily solved using a
series of one-vs-all classifiers. However, as the label dimensionality
increases to several thousand, the parameter space becomes extremely large, and
it is no longer possible to use the one-vs-all technique. Here we propose a
model based on the factorization of higher order moments of the words in the
corpora, as well as the cross moment between the labels and the words for
multi-label prediction. Our model provides guaranteed convergence bounds on the
estimated parameters. Further, our model takes only three passes through the
training dataset to extract the parameters, resulting in a highly scalable
algorithm that can train on GB's of data consisting of millions of documents
with hundreds of thousands of labels using a nominal resource of a single
processor with 16GB RAM. Our model achieves 10x-15x order of speed-up on
large-scale datasets while producing competitive performance in comparison with
existing benchmark algorithms.


title:
RANS solver for microscale pollution dispersion problems in areas with
  vegetation: Development and validation

abstract:
  We present a description and validation of a finite volume solver aimed at
solving the problems of microscale urban flows where vegetation is present. The
solver is based on the five equation system of Reynolds-averaged Navier-Stokes
equations for atmospheric boundary layer flows, which are complemented by the
k-epsilon turbulence model. The vegetation is modelled as a porous zone, and
the effects of the vegetation are included in the momentum and turbulence
equations. A detailed dry deposition model is incorporated in the pollutant
transport equation, allowing the investigation of the filtering properties of
urban vegetation. The solver is validated on four test cases to assess the
components of the model: the flow and pollutant dispersion around the 2D hill,
the temporal evolution of the rising thermal bubble, the flow through and
around the forest canopy, and a hedgerow filtering the particle-laden flow.
Generally good agreement with the measured values or previously computed
numerical solution is observed, although some deficiencies of the model are
identified. These are related to the chosen turbulence model and to the
uncertainties of the vegetation properties.


title: Cygnus Loop: A double bubble?

abstract:
  The Cygnus Loop is a well-studied supernova remnant (SNR) that has been
observed across the electromagnetic spectrum. Although widely believed to be an
SNR shell with a blow- out region in the south, we consider the possibility
that this object is two SNRs projected along the same line-of-sight by using
multi-wavelength images and modelling. Our results show that a model of two
objects including some overlap region/interaction between the two objects has
the best match to the observed data.


title: Equivariant $A$-theory

abstract:
  We give a new construction of the equivariant $K$-theory of group actions
(cf. Barwick et al.), producing an infinite loop $G$-space for each Waldhausen
category with $G$-action, for a finite group $G$. On the category $R(X)$ of
retractive spaces over a $G$-space $X$, this produces an equivariant lift of
Waldhausen's functor $A(X)$, and we show that the $H$-fixed points are the
bivariant $A$-theory of the fibration $X_{hH}\to BH$. We then use the framework
of spectral Mackey functors to produce a second equivariant refinement $A_G(X)$
whose fixed points have tom Dieck type splittings. We expect this second
definition to be suitable for an equivariant generalization of the parametrized
$h$-cobordism theorem.


title: Static and rotating solutions for Vector-Galileon theories

abstract:
  We consider a particular truncation of the generalized Proca field theory in
four dimensions for which we construct a static and axisymmetric rotating black
hole "stealth solutions", namely solutions with (Anti) de Sitter or Kerr metric
but non-trivial vector field. The static configuration is promoted to a
backreacting black hole with asymptotic (Anti) de Sitter behavior by turning on
a nonlinear electrodynamic source given as a fixed power of the Maxwell
invariant. Finally we extend our solutions to arbitrary dimensions.


title: Galerkin least squares finite element method for the obstacle problem

abstract:
  We construct a consistent multiplier free method for the finite element
solution of the obstacle problem. The method is based on an augmented
Lagrangian formulation in which we eliminate the multiplier by use of its
definition in a discrete setting. We prove existence and uniqueness of discrete
solutions and optimal order a priori error estimates for smooth exact
solutions. Using a saturation assumption we also prove an a posteriori error
estimate. Numerical examples show the performance of the method and of an
adaptive algorithm for the control of the discretization error.


title: The Generalized Subterm Criterion in TTT2

abstract:
  We present an SMT encoding of a generalized version of the subterm criterion
and evaluate its implementation in TTT2.


title: Feedback Motion Planning for Liquid Transfer using Supervised Learning

abstract:
  We present a novel motion planning algorithm for transferring a liquid body
from a source to a target container. Our approach uses a receding-horizon
optimization strategy that takes into account fluid constraints and avoids
collisions. In order to efficiently handle the high-dimensional configuration
space of a liquid body, we use system identification to learn its dynamics
characteristics using a neural network. We generate the training dataset using
stochastic optimization in a transfer-problem-specific search space. The
runtime feedback motion planner is used for real-time planning and we observe
high success rate in our simulated 2D and 3D fluid transfer benchmarks.


title:
Surface superconductivity as the primary cause of broadening of
  superconducting transition in Nb-films

abstract:
  We study the origin of broadening of superconducting transition in sputtered
Nb films. From simultaneous tunneling and transport measurements we conclude
that the upper critical field Hc2 always corresponds to the bottom of
transition R~0, while the top R~Rn occurs close to the critical field for
destruction of surface superconductivity Hc3 ~ 1.7 Hc2. The two-dimensional
nature of superconductivity at H>Hc2 is confirmed by cusp-like angular
dependence of magnetoresistance. Our data indicates that surface
superconductivity is remarkably robust even in disordered polycrystalline films
and, surprisingly, even in perpendicular magnetic fields.


title:
On the Erd\"{o}s flat polynomials problem, Chowla conjecture and Riemann
  Hypothesis

abstract:
  There are no square $L^2$-flat sequences of polynomials of the type
  $$\frac{1}{\sqrt q}( \epsilon_0 + \epsilon_1z + \epsilon_2z^2 + \cdots +
\epsilon_{q-2}z^{q-2} +\epsilon_q z^{q-1}),$$ where for each $j,~~ 0 \leq j\leq
q-1,~\epsilon_j = \pm 1$. It follows that Erd\"{o}s's conjectures on Littlewood
polynomials hold. Consequently, Turyn-Golay's conjecture is true, that is,
there are only finitely many Barker sequences. We further get that the spectrum
of dynamical systems arising from continuous Morse sequences is singular. This
settles an old question due to M. Keane. Applying our reasoning to the
Liouville function we obtain that the popular Chowla conjecture on the
%Bernouillicity normality of the Liouville function implies Riemann hypothesis.


title: Quasi-stationary Monte Carlo and the ScaLE Algorithm

abstract:
  This paper introduces a class of Monte Carlo algorithms which are based upon
the simulation of a Markov process whose quasi-stationary distribution
coincides with a distribution of interest. This differs fundamentally from,
say, current Markov chain Monte Carlo methods which simulate a Markov chain
whose stationary distribution is the target. We show how to approximate
distributions of interest by carefully combining sequential Monte Carlo methods
with methodology for the exact simulation of diffusions. The methodology
introduced here is particularly promising in that it is applicable to the same
class of problems as gradient based Markov chain Monte Carlo algorithms but
entirely circumvents the need to conduct Metropolis-Hastings type accept/reject
steps whilst retaining exactness: the paper gives theoretical guarantees
ensuring the algorithm has the correct limiting target distribution.
Furthermore, this methodology is highly amenable to big data problems. By
employing a modification to existing na{\"\i}ve sub-sampling and control
variate techniques it is possible to obtain an algorithm which is still exact
but has sub-linear iterative cost as a function of data size.


title:
First-Order Bayesian Network Specifications Capture the Complexity Class
  PP

abstract:
  The point of this note is to prove that a language is in the complexity class
PP if and only if the strings of the language encode valid inferences in a
Bayesian network defined using function-free first-order logic with equality.


title:
Reactive Multi-Context Systems: Heterogeneous Reasoning in Dynamic
  Environments

abstract:
  Managed multi-context systems (mMCSs) allow for the integration of
heterogeneous knowledge sources in a modular and very general way. They were,
however, mainly designed for static scenarios and are therefore not well-suited
for dynamic environments in which continuous reasoning over such heterogeneous
knowledge with constantly arriving streams of data is necessary. In this paper,
we introduce reactive multi-context systems (rMCSs), a framework for reactive
reasoning in the presence of heterogeneous knowledge sources and data streams.
We show that rMCSs are indeed well-suited for this purpose by illustrating how
several typical problems arising in the context of stream reasoning can be
handled using them, by showing how inconsistencies possibly occurring in the
integration of multiple knowledge sources can be handled, and by arguing that
the potential non-determinism of rMCSs can be avoided if needed using an
alternative, more skeptical well-founded semantics instead with beneficial
computational properties. We also investigate the computational complexity of
various reasoning problems related to rMCSs. Finally, we discuss related work,
and show that rMCSs do not only generalize mMCSs to dynamic settings, but also
capture/extend relevant approaches w.r.t. dynamics in knowledge representation
and stream reasoning.


title:
Improved Dynamic Predictions from Joint Models of Longitudinal and
  Survival Data with Time-Varying Effects using P-splines

abstract:
  In the field of cardio-thoracic surgery, valve function is monitored over
time after surgery. The motivation for our research comes from a study which
includes patients who received a human tissue valve in the aortic position.
These patients are followed prospectively over time by standardized
echocardiographic assessment of valve function. Loss of follow-up could be
caused by valve intervention or the death of the patient. One of the main
characteristics of the human valve is that its durability is limited.
Therefore, it is of interest to obtain a prognostic model in order for the
physicians to scan trends in valve function over time and plan their next
intervention, accounting for the characteristics of the data.
  Several authors have focused on deriving predictions under the standard joint
modeling of longitudinal and survival data framework that assumes a constant
effect for the coefficient that links the longitudinal and survival outcomes.
However, in our case this may be a restrictive assumption. Since the valve
degenerates, the association between the biomarker with survival may change
over time.
  To improve dynamic predictions we propose a Bayesian joint model that allows
a time-varying coefficient to link the longitudinal and the survival processes,
using P-splines. We evaluate the performance of the model in terms of
discrimination and calibration, while accounting for censoring.


title: Laser Spectroscopy of Muonic Atoms and Ions

abstract:
  Laser spectroscopy of the Lamb shift (2S-2P energy difference) in light
muonic atoms or ions, in which one negative muon $\mu^-$ is bound to a nucleus,
has been performed. The measurements yield significantly improved values of the
root-mean-square charge radii of the nuclei, owing to the large muon mass,
which results in a vastly increased muon wave function overlap with the
nucleus. The values of the proton and deuteron radii are 10 and 3 times more
accurate than the respective CODATA values, but 7 standard deviations smaller.
Data on muonic helium-3 and -4 ions is being analyzed and will give new
insights. In future, the (magnetic) Zemach radii of the proton and the helium-3
nuclei will be determined from laser spectroscopy of the 1S hyperfine
splittings, and the Lamb shifts of muonic Li, Be and B can be used to improve
the respective charge radii.


title: Read, Tag, and Parse All at Once, or Fully-neural Dependency Parsing

abstract:
  We present a dependency parser implemented as a single deep neural network
that reads orthographic representations of words and directly generates
dependencies and their labels. Unlike typical approaches to parsing, the model
doesn't require part-of-speech (POS) tagging of the sentences. With proper
regularization and additional supervision achieved with multitask learning we
reach state-of-the-art performance on Slavic languages from the Universal
Dependencies treebank: with no linguistic features other than characters, our
parser is as accurate as a transition- based system trained on perfect POS
tags.


title:
Cooperative Phoneotypes: Exploring Phone-based Behavioral Markers of
  Cooperation

abstract:
  Cooperation is a fundamental human concept studied across multiple social and
biological disciplines. Traditional methods for eliciting an individual's
propensity to cooperate have included surveys and laboratory experiments and
multiple such studies have connected an individual's cooperation level with her
social behavior. We describe a novel approach to model an individual's
cooperation level based on her phoneotype i.e. a composite of an individual's
traits as observable via a mobile phone. This phone sensing-based method can
potentially complement surveys, thus providing a cheaper, faster, automated
method for generating insights into cooperation levels of users. Based on a
10-week field study involving 54 participants, we report that: (1) multiple
phone-based signals were significantly associated with participant's
cooperation attitudes; and (2) combining phone-based signals yielded a
predictive model with AUCROC of 0.945 that performed significantly better than
a comparable demography-based model at predicting individual cooperation
propensities. The results pave the way for individuals and organizations to
identify more cooperative peers in personal, social, and commerce related
settings.


title: Optimal Design of Fibre Reinforced Membrane Structures

abstract:
  A design problem of finding an optimally stiff membrane structure by
selecting one-dimensional fiber reinforcements is formulated and solved. The
membrane model is derived in a novel manner from a particular three-dimensional
linear elastic orthotropic model by appropriate assumptions. The design problem
is given in the form of two minimization statements, reminiscent of a Nash
game. After finite element discretization, the separate treatment of each of
the two minimization statements follows from classical results and methods of
structural optimization: the stiffest orientation of reinforcing fibers
coincides with principal stresses and the separate selection of density of
fibers is a convex problem that can be solved by optimality criteria
iterations. Numerical solutions are shown for two particular configurations.
The first for a statically determined structure and the second for a statically
undetermined one. The latter shows related but non-unique solutions.


title:
Phenomenology of the SU(3)_C \otimes SU(2)_L \otimes SU(3)_R \otimes
  U(1)_X gauge model

abstract:
  We study the left-right asymmetric model based on SU(3)_C \otimes SU(2)_L
\otimes SU(3)_R \otimes U(1)_X gauge group, which improves the theoretical and
phenomenological aspects of the known left-right symmetric model. This new
gauge symmetry yields that the fermion generation number is three, and the
tree-level flavor-changing neutral currents arise in both gauge and scalar
sectors. Also, it can provide the observed neutrino masses as well as dark
matter automatically. Further, we investigate the mass spectrum of the gauge
and scalar fields. All the gauge interactions of the fermions and scalars are
derived. We examine the tree-level contributions of the new neutral vector,
Z'_R, and new neutral scalar, H_2, to flavor-violating neutral meson mixings,
say K-\bar{K}, B_d-\bar{B}_d, and B_s-\bar{B}_s, which strongly constrain the
new physics scale as well as the elements of the right-handed quark mixing
matrices. The bounds for the new physics scale are in agreement with those
coming from the \rho-parameter as well as the mixing parameters between W, Z
bosons and new gauge bosons.


title: R-Matrix Calculations for Few-Quark Bound States

abstract:
  The R--matrix method is implemented to study the heavy charm and bottom
diquark, triquark, tetraquark and pentaquarks in configuration space, as the
bound states of quark--antiquark, diquark--quark, diquark--antidiquark and
diquark--antitriquark systems, respectively. The mass spectrum and the size of
these systems are calculated for different partial wave channels. The
calculated masses are compared with recent theoretical results obtained by
other methods in momentum and configuration spaces and also by available
experimental data.


title: Foundations of Boij-S\"oderberg Theory for Grassmannians

abstract:
  Boij-S\"oderberg theory characterizes syzygies of graded modules and sheaves
on projective space. This paper continues earlier work with S. Sam, extending
the theory to the setting of $GL_k$-equivariant modules and sheaves on
Grassmannians. Algebraically, we study modules over a polynomial ring in $k n$
variables, thought of as the entries of a $k \times n$ matrix.
  We give equivariant analogues of two important features of the ordinary
theory: the Herzog-K\"uhl equations and the pairing between Betti and
cohomology tables. As a necessary step, we also extend previous results,
concerning the base case of square matrices, to cover complexes other than free
resolutions.
  Our statements specialize to those of ordinary Boij-S\"oderberg theory when
$k=1$. Our proof of the equivariant pairing gives a new proof in the graded
setting: it relies on finding perfect matchings on certain graphs associated to
Betti tables.
  Finally, we give preliminary results on $2 \times 3$ matrices, exhibiting
certain classes of extremal rays on the cone of Betti tables.


title:
Sharp conditions to avoid collisions in singular Cucker-Smale
  interactions

abstract:
  We consider the Cucker-Smale flocking model with a singular communication
weight $\psi(s) = s^{-\alpha}$ with $\alpha > 0$. We provide a critical value
of the exponent $\alpha$ in the communication weight leading to global
regularity of solutions or finite-time collision between particles. For $\alpha
\geq 1$, we show that there is no collision between particles in finite time if
they are placed in different positions initially. For $\alpha\geq 2$ we
investigate a version of the Cucker-Smale model with expanded singularity i.e.
with weight $\psi_\delta(s) = (s-\delta)^{-\alpha}$, $\delta\geq 0$. For such
model we provide a uniform with respect to the number of particles estimate
that controls the $\delta$-distance between particles. In case of $\delta = 0$
it reduces to the estimate of non-collisioness.


title: Learning Sparse Graphs Under Smoothness Prior

abstract:
  In this paper, we are interested in learning the underlying graph structure
behind training data. Solving this basic problem is essential to carry out any
graph signal processing or machine learning task. To realize this, we assume
that the data is smooth with respect to the graph topology, and we parameterize
the graph topology using an edge sampling function. That is, the graph
Laplacian is expressed in terms of a sparse edge selection vector, which
provides an explicit handle to control the sparsity level of the graph. We
solve the sparse graph learning problem given some training data in both the
noiseless and noisy settings. Given the true smooth data, the posed sparse
graph learning problem can be solved optimally and is based on simple rank
ordering. Given the noisy data, we show that the joint sparse graph learning
and denoising problem can be simplified to designing only the sparse edge
selection vector, which can be solved using convex optimization.


title:
A terrestrial planet candidate in a temperate orbit around Proxima
  Centauri

abstract:
  At a distance of 1.295 parsecs, the red-dwarf Proxima Centauri ($\alpha$
Centauri C, GL 551, HIP 70890, or simply Proxima) is the Sun's closest stellar
neighbor and one of the best studied low-mass stars. It has an effective
temperature of only $\sim$ 3050 K, a luminosity of $\sim$0.1 per cent solar, a
measured radius of 0.14 R$_\odot$ and a mass of about 12 per cent the mass of
the Sun. Although Proxima is considered a moderately active star, its rotation
period is $\sim$ 83 days, and its quiescent activity levels and X-ray
luminosity are comparable to the Sun's. New observations reveal the presence of
a small planet orbiting Proxima with a minimum mass of 1.3~Earth masses and an
orbital period of $\sim$11.2 days. Its orbital semi-major axis is $\sim0.05$
AU, with an equilibrium temperature in the range where water could be liquid on
its surface.


title:
Non-standard interactions with high-energy atmospheric neutrinos at
  IceCube

abstract:
  Non-standard interactions in the propagation of neutrinos in matter can lead
to significant deviations from expectations within the standard neutrino
oscillation framework and atmospheric neutrino detectors have been considered
to set constraints. However, most previous works have focused on relatively
low-energy atmospheric neutrino data. Here, we consider the one-year
high-energy through-going muon data in IceCube, which has been already used to
search for light sterile neutrinos, to constrain new interactions in the
$\mu\tau$-sector. In our analysis we include several systematic uncertainties
on both, the atmospheric neutrino flux and on the detector properties, which
are accounted for via nuisance parameters. After considering different primary
cosmic-ray spectra and hadronic interaction models, we obtain the most
stringent bound on the off-diagonal $\varepsilon_{\mu \tau}$ parameter to date,
with the 90\% credible interval given by $-6.0 \times 10^{-3} <
\varepsilon_{\mu \tau} < 5.4 \times 10^{-3}$. In addition, we also estimate the
expected sensitivity after 10~years of collected data in IceCube and study the
precision at which non-standard parameters could be determined for the case of
$\varepsilon_{\mu \tau}$ near its current bound.


title: Dynamics of electrons and explicit solutions of Dirac-Weyl systems

abstract:
  Explicit solutions of Dirac-Weyl system, which is essential in graphene
studies, are constructed using our recent approach to the construction of
solutions of dynamical systems. The obtained classes of solutions are much
wider than the ones, which were considered before. It is proved that neither
constructed potentials nor corresponding solutions have singularities. Various
examples are provided.


title:
Navigation of C. elegans in three-dimensional media: roll maneuvers and
  planar turns

abstract:
  Free-living nematode Caenorhabditis elegans is a powerful genetic model,
essential for investigations ranging from behavior to neuroscience to aging,
and locomotion is a key observable used in these studies. However, despite the
fact that in its natural environment C. elegans moves in three-dimensional (3D)
complex media (decomposing organic matter and water), quantitative in
vestigations of its locomotion have been limited to two-dimensional (2D)
motion. Based on our recent quantitative analysis of 2D turning maneuvers
[Phys. Fluids 25, 081902 (2013)] we follow with the first quantitative
description of how C. elegans moves in 3D environments. We show that by
superposing body torsion and 2D undulations, a burrowing or swimming nematode
can rotate the undulation plane. A combination of these roll maneuvers and 2D
turns associated with variation of undulation-wave parameters allows the
nematode to explore 3D space. We apply our model to analyze 3D chemotaxis of
nematodes burrowing in a gel and swimming in water; we conclude that the
nematode can achieve efficient chemotaxis in different environments without
adjusting its sensory-motor response to chemical signals. Implications of our
findings for understanding of 3D neuromuscular control of nematode body are
discussed.


title:
SOAR observations of the high-viscosity accretion disc of the dwarf nova
  V4140 Sagitarii in quiescence and in outburst

abstract:
  We report the analysis of 22 B-band light curves of the dwarf nova V4140 Sgr
obtained with SOI/SOAR during two nights along the decline of a superoutburst
in 2006 Sep 12-24 and in quiescence over 50 days following the superoutburst.
Three-dimensional eclipse mapping of the outburst light curves indicates that
the accretion disc is elliptical (eccentricity e=0.13) and that superhump
maximum occurs when the mass donor star is aligned with the bulge of the
elliptical disc. The accretion disc is geometrically thin both in outburst and
in quiescence; it fills the primary Roche lobe in outburst and shrinks to about
half this size in quiescence. The stability of the eclipse shape, width and
depth along quiescence and the derived disc surface brightness distribution
indicate that the quiescent accretion disc is in a high-viscosity,
steady-state. Flickering mapping of the quiescent data reveal that the
low-frequency flickering arises from an azimuthally-extended stream-disc impact
region at disc rim and from the innermost disc region, whereas the
high-frequency flickering originates in the accretion disc. Assuming the
disc-related flickering to be caused by fluctuations in the energy dissipation
rate induced by magneto-hydrodynamic turbulence (Gertseema & Achterberg 1992),
we find that the quiescent disc viscosity parameter is large (alpha ~ 0.2-0.4)
at all radii. The high-viscosity quiescent disc and the inferred low disc
temperatures in superoutburst are inconsistent with expectations of the
disc-instability model, and lead to the conclusion that the outbursts of V4140
Sgr are powered by mass transfer bursts from its donor star.


title: Currentless reversal of N\'eel vector in antiferromagnets

abstract:
  The bias driven perpendicular magnetic anisotropy is a magneto-electric
effect that can realize 90$^\circ$ magnetization rotation and even 180$% ^\circ
$ flip along the easy axis in the ferromagnets with a minimal energy
consumption. This study theoretically demonstrates a similar phenomenon of the
N\'{e}el vector reversal via a short electrical pulse that can mediate
perpendicular magnetic anisotropy in the antiferromagnets. The analysis based
on the dynamical equations as well as the micro-magnetic simulations reveals
the important role of the inertial behavior in the antiferromagnets that
facilitates the N\'{e}el vector to overcome the barrier between two free-energy
minima of the bistable states along the easy axis. In contrast to the
ferromagnets, this N\'{e}el vector reversal does not accompany angular moment
transfer to the environment, leading to acceleration in the dynamical response
by a few orders of magnitude. Further, a small switching energy requirement of
a few attojoules illustrates an added advantage of the phenomenon in low-power
spintronic applications.


title:
Another New Foundation: A Theory with Combined Concepts from Set Theory,
  Type Theory and Le\'{s}niewski's Mereology

abstract:
  This paper introduces a new theory which encompasses concepts and ideas from
set theory, type theory, and Le\'{s}niewski's mereology and describes its
possibility as an alternative foundation for mathematics. In the introduction
section I will introduce motives for development of the theory and some remarks
on the methods of presentation. Axioms of the theory and their philosophical
background and justification on the basis of intuitive view are discussed next.
Discussed after are realizations of mathematical concepts such as $\mathbb{N}$,
$\mathbb{Z}$, $\mathbb{Q}$, $\mathbb{R}$, $\mathbb{C}$, etc. Then this paper
concludes with comparisons between the theory and ZFC and its mathematical
limitations.


title: Factors controlling oxygen migration barriers in perovskites

abstract:
  Perovskites with fast oxygen ion conduction can enable technologies like
solid oxide fuel cells. One component of fast oxygen ion conduction is low
oxygen migration barrier. Here we apply ab initio methods on over 40
perovskites to produce a database of oxygen migration barriers ranging from 0.2
to 1.6 eV. Mining the database revealed that systems with low barriers also
have low metal-oxygen bond strength, as measured by oxygen vacancy formation
energy and oxygen p-band center energy. These correlations provide a powerful
descriptor for the development of new oxygen ion conductors and may explain the
poor stability of some of the best oxygen conducting perovskites under reducing
conditions. Other commonly-cited measures of space, volume, or structure
ideality showed only weak correlation with migration barrier. The lowest
migration barriers (< 0.5 eV) belong to perovskites with non-transition-metal
B-site cations, and may require vacancy-creation strategies that involve no
dopants or low-association dopants for optimal performance.


title: Math-Aware Search Engines: Physics Applications and Overview

abstract:
  Search engines for equations now exist, which return results matching the
query's mathematical meaning or structural presentation. Operating over
scientific papers, online encyclopedias, and math discussion forums, their
content includes physics, math, and other sciences. They enable physicists to
avoid jargon and more easily target mathematical content within and across
disciplines. As a natural extension of keyword-based search, they open up a new
world for discovering both exact and approximate mathematical solutions;
physical systems' analogues and alternative models; and physics' patterns.
  This review presents the existing math-aware search engines, discusses
methods for maximizing their search success, and overviews their math-matching
capabilities. Proposed applications to physics are also given, to contribute
towards developers' and physicists' exploration of the newly available search
horizons.


title:
Magnetic, specific heat and electrical transport properties of
  Frank-Kasper cage compounds RTM$_2$Al$_{20}$ [R = Eu,Gd and La ; TM = V,Ti]

abstract:
  Single crystals of Frank-Kasper compounds RTM$_2$Al$_{20}$ (R = Eu, Gd and
La; TM = V and Ti) were grown by self-flux method and their physical properties
were investigated through magnetization ($M$), magnetic susceptibility
($\chi$), specific heat ($C_P$) and electrical resistivity ($\rho$)
measurements. Powder x-ray diffraction studies and structural analysis showed
that these compounds crystallize in the cubic crystal structure with the space
group $Fd\overline{3}m$. The magnetic susceptibility for the compounds
EuTi$_2$Al$_{20}$ and GdTi$_2$Al$_{20}$ showed a sudden jump below the N{\'e}el
temperature $T_N$ indicative of plausible double magnetic transition. Specific
heat ($C_P$) and electrical resistivity ($\rho$) measurements also confirm the
first-order magnetic transition (FOMT) and possible double magnetic
transitions. Temperature variation of heat capacity showed a sharp phase
transition and huge $C_P$ value for the (Eu/Gd)Ti$_2$Al$_{20}$ compounds Full
width at half-maximum (FWHM) $<$ 0.2 K) which is reminiscent of a first-order
phase transition and a unique attribute among RTM$_2$Al$_{20}$ compounds. We
observed clear anomaly between heating and cooling cycle in temperature-time
relaxation curve for the compounds GdTi$_2$Al$_{20}$ (2.38 $K$) and
EuTi$_2$Al$_{20}$ (3.2 $K$) which is indicating a thermal arrest due to the
latent heat. The temperature variation of $S_{mag}$ for GdTi$_2$Al$_{20}$
saturates to a value $0.95R\ln8$ while the other magnetic systems exhibited
still lower entropy saturation values in the high temperature limit.
Resistivity measurements showed that all the samples behave as normal Fermi
liquid type compounds and $\rho(T)$ due to electron-phonon scattering follows
Bloch-Gr$\ddot{\textrm u}$neisen-Mott relation in the paramagnetic region.


title:
Extracting Work from a single heat bath using velocity dependent
  feedback

abstract:
  Thermodynamics of nanoscale devices is an active area of research. Despite
their noisy surround- ing they often produce mechanical work (e.g. micro-heat
engines) or display rectified Brownian motion (e.g. molecular motors). This
invokes the research in terms of experimentally quantifiable thermodynamic
efficiencies. To enhance the efficiency of such devices, close-loop control is
an useful technique. Here a single Brownian particle is driven by a harmonic
confinement with time-periodic contraction and expansion, together with a
velocity feedback that acts on the particle only when the trap contracts. Due
to this feedback we are able to extract thermodynamic work out of the system
having single heat bath without violating the Second Law of Thermodynamics. We
analyse the system using stochastic thermodynamics.


title:
Complexity of Universality and Related Problems for Partially Ordered
  NFAs

abstract:
  Partially ordered nondeterminsitic finite automata (poNFAs) are NFAs whose
transition relation induces a partial order on states, that is, for which
cycles occur only in the form of self-loops on a single state. A poNFA is
universal if it accepts all words over its input alphabet. Deciding
universality is PSPACE-complete for poNFAs, and we show that this remains true
even when restricting to a fixed alphabet. This is nontrivial since standard
encodings of alphabet symbols in, e.g., binary can turn self-loops into longer
cycles. A lower coNP-complete complexity bound can be obtained if we require
that all self-loops in the poNFA are deterministic, in the sense that the
symbol read in the loop cannot occur in any other transition from that state.
We find that such restricted poNFAs (rpoNFAs) characterise the class of
$\mathcal{R}$-trivial languages, and we establish the complexity of deciding if
the language of an NFA is $\mathcal{R}$-trivial. Nevertheless, the limitation
to fixed alphabets turns out to be essential even in the restricted case:
deciding universality of rpoNFAs with unbounded alphabets is PSPACE-complete.
Based on a close relation between universality and the problems of inclusion
and equivalence, we also obtain the complexity results for these two problems.
Finaly, we show that the languages of rpoNFAs are definable by deterministic
(one-unambiguous) regular expressions, which makes them interesting in schema
languages for XML data.


title:
MUG: A Parameterless No-Reference JPEG Quality Evaluator Robust to Block
  Size and Misalignment

abstract:
  In this letter, a very simple no-reference image quality assessment (NR-IQA)
model for JPEG compressed images is proposed. The proposed metric called median
of unique gradients (MUG) is based on the very simple facts of unique gradient
magnitudes of JPEG compressed images. MUG is a parameterless metric and does
not need training. Unlike other NR-IQAs, MUG is independent to block size and
cropping. A more stable index called MUG+ is also introduced. The experimental
results on six benchmark datasets of natural images and a benchmark dataset of
synthetic images show that MUG is comparable to the state-of-the-art indices in
literature. In addition, its performance remains unchanged for the case of the
cropped images in which block boundaries are not known. The MATLAB source code
of the proposed metrics is available at
https://dl.dropboxusercontent.com/u/74505502/MUG.m and
https://dl.dropboxusercontent.com/u/74505502/MUGplus.m.


title:
Transition from Jaynes-Cummings to Autler-Townes ladder in a quantum
  dot-microcavity system

abstract:
  We study experimentally and theoretically a coherently-driven
strongly-coupled quantum dot-microcavity system. Our focus is on physics of the
unexplored intermediate excitation regime where the resonant laser field
dresses a strongly-coupled single exciton-photon (polariton) system resulting
in a ladder of laser-dressed Jaynes-Cummings states. In that case both the
coupling of the emitter to the confined light field of the microcavity and to
the light field of the external laser are equally important, as proved by
observation of injection pulling of the polariton branches by an external
laser. This intermediate interaction regime is of particular interest since it
connects the purely quantum mechanical Jaynes-Cummings ladder and the
semi-classical Autler-Townes ladder. Exploring the driving strength-dependence
of the mutually coupled system we establish the maximum in the resonance
fluorescence signal to be a robust fingerprint of the intermediate regime and
observe signatures indicating the laser-dressed Jaynes-Cummings ladder. In
order to address the underlying physics we excite the coupled system via the
matter component of fermionic nature undergoing saturation - in contrast to
commonly used cavity-mediated excitation.


title:
Structure, hydrolysis and diffusion of aqueous vanadium ions from
  Car-Parrinello molecular dynamics

abstract:
  A molecular level understanding of the properties of electroactive vanadium
species in aqueous solution is crucial for enhancing the performance of
vanadium redox flow batteries (RFB). Here, we employ Car-Parrinello molecular
dynamics (CPMD) simulations based on density functional theory to investigate
the hydration structures, first hydrolysis reaction and diffusion of aqueous
V$^{2+}$, V$^{3+}$, VO$^{2+}$, and VO$_2^+$ ions at 300 K. The results indicate
that the first hydration shell of both V$^{2+}$ and V$^{3+}$ contains six water
molecules, while VO$^{2+}$ is coordinated to five and VO$_2^+$ to three water
ligands. The first acidity constants (p$K_\mathrm{a}$) estimated using
metadynamics simulations are 2.47, 3.06 and 5.38 for aqueous V$^{3+}$, VO$_2^+$
and VO$^{2+}$, respectively, while V$^{2+}$ is predicted to be a fairly weak
acid in aqueous solution with a p$K_\mathrm{a}$ value of 6.22. We also show
that the presence of chloride ions in the first coordination sphere of the
aqueous VO$_2^+$ ion has a significant impact on water hydrolysis leading to a
much higher p$K_\mathrm{a}$ value of 4.8. This should result in a lower
propensity of aqueous VO$_2^+$ for oxide precipitation reaction in agreement
with experimental observations for chloride-based electrolyte solutions. The
computed diffusion coefficients of vanadium species in water at room
temperature are found to increase as V$^{3+}$ $<$ VO$_2^+$ $<$ VO$^{2+}$ $<$
V$^{2+}$ and thus correlate with the simulated hydrolysis constants, namely,
the higher the p$K_\mathrm{a}$ value, the greater the diffusion coefficient.


title: XMM-Newton Studies of the Supernova Remnant G350.0$-$2.0

abstract:
  We report the results of XMM-Newton observations of the Galactic
mixed-morphology supernova remnant G350.0$-$2.0. Diffuse thermal X-ray emission
fills the north-western part of the remnant surrounded by radio shell-like
structures. We did not detect any X-ray counterpart of the latter structures,
but found several bright blobs within the diffuse emission. The X-ray spectrum
of the most part of the remnant can be described by a collisionally-ionized
plasma model VAPEC with solar abundances and a temperature of $\approx 0.8$
keV. The solar abundances of plasma indicate that the X-ray emission comes from
the shocked interstellar material. The overabundance of Fe was found in some of
the bright blobs. We also analysed the brightest point-like X-ray source 1RXS
J172653.4$-$382157 projected on the extended emission. Its spectrum is well
described by the two-temperature optically thin thermal plasma model MEKAL
typical for cataclysmic variable stars. The cataclysmic variable source nature
is supported by the presence of a faint ($g\approx21$) optical source with
non-stellar spectral energy distribution at the X-ray position of 1RXS
J172653.4$-$382157. It was detected with the XMM-Newton optical/UV monitor in
the $U$ filter and was also found in the archival H$\alpha$ and
optical/near-infrared broadband sky survey images. On the other hand, the X-ray
spectrum is also described by the power law plus thermal component model
typical for a rotation powered pulsar. Therefore, the pulsar interpretation of
the source cannot be excluded. For this source, we derived the upper limit for
the pulsed fraction of 27 per cent.


title:
Opinion dynamics in social networks with stubborn agents: an issue-based
  perspective

abstract:
  Classic models on opinion dynamics usually focus on a group of agents forming
their opinions interactively over single issue. Yet generally consensus can not
be achieved over single issue when agents are not completely open to
interpersonal influence. In this paper, opinion consensus in social networks
with stubborn agents is considered over issue sequences. The social network
with stubborn agents is described by the Friedkin-Johnsen (F-J) model where
agents are stubborn to their initial opinions. Firstly, we propose some
sufficient and necessary conditions both in terms of network topology and
system matrix for convergence of the F-J model over single issue. Secondly,
opinion consensus of the F-J model is investigated over issue sequences. Our
analysis establishes connections between the interpersonal influence network
and the network describing the relationship of agents' initial opinions for
successive issues. Taking advantage of these connections, we derive the
sufficient and necessary condition for the F-J model to achieve opinion
consensus over issue sequences. Finally, we consider a more general scenario
where each agent has bounded confidence in forming its initial opinion for
every issue. By analyzing the evolution of agents' ultimate opinions for each
issue over issue sequences, we prove that the connectivity of the
state-dependent network is preserved in this setting. Then the conditions for
agents to achieve opinion consensus over issue sequences are proposed.
Simulation examples are provided to illustrate the effectiveness of our
theoretical results.


title: Effective description of dark matter as a viscous fluid

abstract:
  Treating dark matter at large scales as an effectively viscous fluid provides
an improved framework for the calculation of the density and velocity power
spectra compared to the standard assumption of an ideal pressureless fluid. We
discuss how this framework can be made concrete through an appropriate
coarse-graining procedure. We also review results that demonstrate that it
improves the convergence of cosmological perturbation theory.


title:
Eigenvectors under a generic perturbation: non-perturbative results from
  the random matrix approach

abstract:
  We consider eigenvectors of the Hamiltonian $H_0$ perturbed by a generic
perturbation $V$ modelled by a random matrix from the Gaussian Unitary Ensemble
(GUE). Using the supersymmetry approach we derive analytical results for the
statistics of the eigenvectors, which are non-perturbative in $V$ and valid for
an arbitrary deterministic $H_0$. Further we generalise them to the case of a
random $H_0$, focusing, in particular, on the Rosenzweig-Porter model. Our
analytical predictions are confirmed by numerical simulations.

categories: cond-mat.dis-nn cond-mat.stat-mech math-ph math.MP quant-ph


title: The edge Folkman number $F_e(3, 3; 4)$ is greater than 19

abstract:
  The set of the graphs which do not contain the complete graph on $q$ vertices
$K_q$ and have the property that in every coloring of their edges in two colors
there exist a monochromatic triangle is denoted by $\mathcal{H}_e(3, 3; q)$.
The edge Folkman numbers $F_e(3, 3; q) = \min\{|V(G)| : G \in \mathcal{H}_e(3,
3; q)\}$ are considered. Folkman proved in 1970 that $F_e(3, 3; q)$ exists if
and only if $q \geq 4$. From the Ramsey number $R(3, 3) = 6$ it becomes clear
that $F_e(3, 3; q) = 6$ if $q \geq 7$. It is also known that $F_e(3, 3; 6) = 8$
and $F_e(3, 3; 5) = 15$. The upper bounds on the number $F_e(3, 3; 4)$ which
follow from the construction of Folkman and from the constructions of some
other authors are not good. In 1975 Erdo\"s posed the problem to prove the
inequality $F_e(3, 3; 4) < 10^{10}$. This Erdo\"s problem was solved by Spencer
in 1978. The last upper bound on $F_e(3, 3; 4)$ was obtained in 2012 by Lange,
Radziszowski and Xu, who proved that $F_e(3, 3; 4) \leq 786$. The best lower
bound on this number is 19 and was obtained 10 years ago by Radziszowski and
Xu. In this paper, we improve this result by proving $F_e(3, 3; 4) \geq 20$. At
the end of the paper, we improve the known bounds on the vertex Folkman number
$F_v(2, 3, 3; 4)$ by proving $20 \leq F_v(2, 3, 3; 4) \leq 24$.


title: ALMA observations of the supergiant B[e] star Wd1-9

abstract:
  Mass-loss in massive stars plays a critical role in their evolution, although
the precise mechanism(s) responsible - radiatively driven winds, impulsive
ejection and/or binary interaction -remain uncertain. In this paper we present
ALMA line and continuum observations of the supergiant B[e] star Wd1-9, a
massive post-Main Sequence object located within the starburst cluster
Westerlund 1. We find it to be one of the brightest stellar point sources in
the sky at millimetre wavelengths, with (serendipitously identified) emission
in the H41alpha radio recombination line. We attribute these properties to a
low velocity (~100 km/s) ionised wind, with an extreme mass-loss rate
6.4x10^-5(d/5kpc)^1.5 Msol/yr. External to this is an extended aspherical
ejection nebula indicative of a prior phase of significant mass-loss. Taken
together, the millimetre properties of Wd1-9 show a remarkable similarity to
those of the highly luminous stellar source MWC349A.We conclude that these
objects are interacting binaries evolving away from the main sequence and
undergoing rapid case-A mass transfer. As such they - and by extension the
wider class of supergiant B[e] stars - may provide a unique window into the
physics of a process that shapes the life-cycle of ~70% of massive stars found
in binary systems.


title:
Joint Asymptotics for Estimating the Fractal Indices of Bivariate
  Gaussian Processes

abstract:
  Multivariate (or vector-valued) processes are important for modeling multiple
variables. The fractal indices of the components of the underlying multivariate
process play a key role in characterizing the dependence structures and
statistical properties of the multivariate process.
  In this paper, under the infill asymptotics framework, we establish joint
asymptotic results for the increment-based estimators of bivariate fractal
indices. Our main results quantitatively describe the effect of the
cross-dependence structure on the performance of the estimators.