title: Minimum Vertex-type Sequence Indexingfor Clusters on Square Lattice

abstract:
  An effective indexing scheme for clusters that enables fast structure
comparison and congruence check is desperately desirable in the field of
mathematics, artificial intelligence, materials science, etc. Here we introduce
the concept of minimum vertex-type sequence for the indexing of clusters on
square lattice, which contains a series of integers each labeling the vertex
type of an atom. The minimum vertex-type sequence is orientation independent,
and it builds a one-to-one correspondence with the cluster. By using minimum
vertex-type sequence for structural comparison and congruence check, only one
type of data is involved, and the largest amount of data to be compared is n
pairs, n is the cluster size. In comparison with traditional coordinate-based
methods and distance-matrix methods, the minimum vertex-type sequence indexing
scheme has many other remarkable advantages. Furthermore, this indexing scheme
can be easily generalized to clusters on other high-symmetry lattices. Our work
can facilitate cluster indexing and searching in various situations, it may
inspire the search of other practical indexing schemes for handling clusters of
large sizes.


title:
$SU(2)$ particle sigma model: the role of non-point symmetries in global
  quantization

abstract:
  In this paper we achieve the quantization of a particle moving on the $SU(2)$
group manifold, that is, the three-dimensional sphere $S^{3}$, by using
group-theoretical methods. For this purpose, a fundamental role is played by
contact, non-point symmetries, i.e., symmetries that leave the
Poincar\'e-Cartan form semi-invariant at the classical level, although not
necessarily the Lagrangian. Special attention is paid to the role played by the
basic quantum commutators, which depart from the canonical, Heisenberg-Weyl
ones, as well as the relationship between the integration measure in the
Hilbert space of the system and the non-trivial topology of the configuration
space. Also, the quantization on momentum space is briefly outlined.


title:
Monopole correlation functions and holographic phases of matter in 2+1
  dimensions

abstract:
  The strong coupling dynamics of a 2+1 dimensional U(1) gauge theory coupled
to charged matter is holographically modeled via a top-down construction with
intersecting D3- and D5-branes. We explore the resulting phase diagram at
finite temperature and charge density using correlation functions of monopole
operators, dual to magnetically charged particles in the higher-dimensional
bulk theory, as a diagnostic.


title:
Long-range Rydberg molecules, Rydberg macrodimers and Rydberg aggregates
  in an ultracold Cs gas

abstract:
  We present an overview of our recent investigations of long-range
interactions in an ultracold Cs Rydberg gas. These interactions are studied by
high-resolution photoassociation spectroscopy, using excitation close to
one-photon transitions into $n$p$_{3/2}$ Rydberg states with pulsed and
continuous-wave ultraviolet laser radiation, and lead to the formation of
long-range Cs$_2$ molecules. We observe two types of molecular resonances. The
first type originates from the correlated excitation of two atoms into
Rydberg-atom-pair states interacting at long range via multipole-multipole
interactions. The second type results from the interaction of one atom excited
to a Rydberg state with one atom in the electronic ground state. Which type of
resonances is observed in the experiments depends on the laser intensity and
frequency and on the pulse sequences used to prepare the Rydberg states. We
obtain insights into both types of molecular resonances by modelling the
interaction potentials, using a multipole expansion of the long-range
interaction for the first type of resonances and a Fermi-contact
pseudo-potential for the second type of resonances. We analyse the relation of
these long-range molecular resonances to molecular Rydberg states and ion-pair
states, and discuss their decay channels into atomic and molecular ions. In
experiments carried out with a two-colour two-photon excitation scheme, we
observe a large enhancement of Rydberg-excitation probability, which we
interpret as a saturable autocatalytic antiblockade phenomenon.


title:
On isotropic Lagrangian submanifolds in the homogeneous nearly K\"ahler
  $\mathbb{S}^3\times\mathbb{S}^3$

abstract:
  In this paper, we show that isotropic Lagrangian submanifolds in a
$6$-dimensional strict nearly K\"ahler manifold are totally geodesic. Moreover,
under some weaker conditions, a complete classification of the $J$-isotropic
Lagrangian submanifolds in the homogeneous nearly K\"ahler $\mathbb{S}^3\times
\mathbb{S}^3$ is also obtained. Here, a Lagrangian submanifold is called
$J$-isotropic, if there exists a function $\lambda$, such that $g((\nabla
h)(v,v,v),Jv)=\lambda$ holds for all unit tangent vector $v$.


title:
The Effects of Consistent Chemical Kinetics Calculations on the
  Pressure-Temperature Profiles and Emission Spectra of Hot Jupiters

abstract:
  In this work we investigate the impact of calculating non-equilibrium
chemical abundances consistently with the temperature structure for the
atmospheres of highly-irradiated, close-in gas giant exoplanets. Chemical
kinetics models have been widely used in the literature to investigate the
chemical compositions of hot Jupiter atmospheres which are expected to be
driven away from chemical equilibrium via processes such as vertical mixing and
photochemistry. All of these models have so far used pressure--temperature
(P-T) profiles as fixed model input. This results in a decoupling of the
chemistry from the radiative and thermal properties of the atmosphere, despite
the fact that in nature they are intricately linked. We use a one-dimensional
radiative-convective equilibrium model, ATMO, which includes a sophisticated
chemistry scheme to calculate P-T profiles which are fully consistent with
non-equilibrium chemical abundances, including vertical mixing and
photochemistry. Our primary conclusion is that, in cases of strong chemical
disequilibrium, consistent calculations can lead to differences in the P-T
profile of up to 100 K compared to the P-T profile derived assuming chemical
equilibrium. This temperature change can, in turn, have important consequences
for the chemical abundances themselves as well as for the simulated emission
spectra. In particular, we find that performing the chemical kinetics
calculation consistently can reduce the overall impact of non-equilibrium
chemistry on the observable emission spectrum of hot Jupiters. Simulated
observations derived from non-consistent models could thus yield the wrong
interpretation. We show that this behaviour is due to the non-consistent models
violating the energy budget balance of the atmosphere.


title: Update Strength in EDAs and ACO: How to Avoid Genetic Drift

abstract:
  We provide a rigorous runtime analysis concerning the update strength, a
vital parameter in probabilistic model-building GAs such as the step size $1/K$
in the compact Genetic Algorithm (cGA) and the evaporation factor $\rho$ in
ACO. While a large update strength is desirable for exploitation, there is a
general trade-off: too strong updates can lead to genetic drift and poor
performance. We demonstrate this trade-off for the cGA and a simple MMAS ACO
algorithm on the OneMax function. More precisely, we obtain lower bounds on the
expected runtime of $\Omega(K\sqrt{n} + n \log n)$ and $\Omega(\sqrt{n}/\rho +
n \log n)$, respectively, showing that the update strength should be limited to
$1/K, \rho = O(1/(\sqrt{n} \log n))$. In fact, choosing $1/K, \rho \sim
1/(\sqrt{n}\log n)$ both algorithms efficiently optimize OneMax in expected
time $O(n \log n)$. Our analyses provide new insights into the stochastic
behavior of probabilistic model-building GAs and propose new guidelines for
setting the update strength in global optimization.


title: On the Ribosomal Density that Maximizes Protein Translation Rate

abstract:
  During mRNA translation, several ribosomes attach to the same mRNA molecule
simultaneously translating it into a protein. This pipelining increases the
protein production rate. A natural and important question is what ribosomal
density maximizes the protein production rate. Using mathematical models of
ribosome flow along both a linear and a circular mRNA molecule we prove that
typically the steady-state production rate is maximized when the ribosomal
density is one half of the maximal possible density. We discuss the
implications of our results to endogenous genes under natural cellular
conditions and also to synthetic biology.


title:
Thickness Engineered Tunnel Field-Effect Transistors based on
  Phosphorene

abstract:
  Thickness engineered tunneling field-effect transistors (TE-TFET) as a high
performance ultra-scaled steep transistor is proposed. This device exploits a
specific property of 2D materials: layer thickness dependent energy bandgap
(Eg). Unlike the conventional hetero-junction TFETs, TE-TFET uses spatially
varying layer thickness to form a hetero-junction. This offers advantages by
avoiding the interface states and lattice mismatch problems. Furthermore, it
boosts the ON-current to 1280$\mu A/\mu m$ for 15nm channel length. TE-TFET
shows a channel length scalability down to 9nm with constant field scaling $E =
V_{DD}/L_{ch}= 30V/nm$. Providing a higher ON current, phosphorene TE-TFET
outperforms the homojunction phosphorene TFET and the TMD TFET in terms of
extrinsic energy-delay product. In this work, the operation principles of
TE-TFET and its performance sensitivity to the design parameters are
investigated by the means of full-band atomistic quantum transport simulation.


title: Nonassociative differential extensions of characteristic p

abstract:
  Let F be a field of characteristic p. We define and investigate
nonassociative differential extensions of F and of a central simple division
algebra over F and give a criterium for these algebras to be division. As
special cases, we obtain classical results for associative algebras by Amitsur
and Jacobson. We construct families of nonassociative division algebras which
can be viewed as generalizations of associative cyclic extensions of a purely
inseparable field extension of exponent one or a central division algebra.
Division algebras which are nonassociative cyclic extensions of a purely
inseparable field extension of exponent one are particularly easy to obtain.


title:
Phase separation and critical percolation in bidimensional spin-exchange
  models

abstract:
  Binary mixtures prepared in an homogeneous phase and quenched into a
two-phase region phase-separate via a coarsening process whereby domains of the
two phases grow in time. With a numerical study of a spin-exchange model we
show that this dynamics first takes a system with equal density of the two
species to a critical percolation state. We prove this claim and we determine
the time-dependence of the growing length associated to this process with the
scaling analysis of the statistical and morphological properties of the
clusters of the two phases.


title:
Radio continuum and X-ray emission from the most extreme FIR-excess
  galaxy NGC 1377: An extremely obscured AGN revealed

abstract:
  Galaxies which strongly deviate from the radio-far IR correlation are of
great importance for studies of galaxy evolution as they may be tracing early,
short-lived stages of starbursts and active galactic nuclei (AGNs). The most
extreme FIR-excess galaxy NGC1377 has long been interpreted as a young dusty
starburst, but millimeter observations of CO lines revealed a powerful
collimated molecular outflow which cannot be explained by star formation alone.
We present new radio observations at 1.5 and 10 GHz obtained with the Jansky
Very Large Array (JVLA) and Chandra X-ray observations towards NGC1377. The
observations are compared to synthetic starburst models to constrain the
properties of the central energy source. We obtained the first detection of the
cm radio continuum and X-ray emission in NGC1377. We find that the radio
emission is distributed in two components, one on the nucleus and another
offset by 4$"$.5 to the South-West. We confirm the extreme FIR-excess of the
galaxy, with a $q_\mathrm{FIR}\simeq$4.2, which deviates by more than
7-$\sigma$ from the radio-FIR correlation. Soft X-ray emission is detected on
the off-nucleus component. From the radio emission we estimate for a young
($<10$ Myr) starburst a star formation rate SFR$<$0.1 M$_\odot$ yr$^{-1}$. Such
a SFR is not sufficient to power the observed IR luminosity and to drive the CO
outflow. We find that a young starburst cannot reproduce all the observed
properties of the nucleus of NGC1377. We suggest that the galaxy may be
harboring a radio-quiet, obscured AGN of 10$^6$M$_\odot$, accreting at
near-Eddington rates. We speculate that the off-nucleus component may be
tracing an hot-spot in the AGN jet.


title:
Particle-in-Cell/Test-Particle Simulations of Technological Plasmas:
  Sputtering Transport in Capacitive Radio Frequency Discharges

abstract:
  The paper provides a tutorial to the conceptual layout of a self-consistently
coupled Particle-In-Cell/Test-Particle model for the kinetic simulation of
sputtering transport in capacitively coupled plasmas at low gas pressures. It
explains when a kinetic approach is actually needed and which numerical
concepts allow for the inherent nonequilibrium behavior of the charged and
neutral particles. At the example of a generic sputtering discharge both the
fundamentals of the applied Monte Carlo methods as well as the conceptual
details in the context of the sputtering scenario are elaborated on. Finally,
two in the context of sputtering transport simulations often exploited
assumptions, namely on the energy distribution of impinging ions as well as on
the test particle approach, are validated for the proposed example discharge.


title: Quantum Corrected Schwarzschild Thin Shell Wormhole

abstract:
  Recently, Ali and Khalil \cite{Farag Ali}, based on the Bohmian quantum
mechanics derived a quantum corrected version of the Schwarzschild metric. In
this paper, we construct a quantum corrected Schwarzschild thin shell wormhole
(QSTSW) and investigate the stability of this wormhole. First we compute the
surface stress at the wormhole throat by applying the Darmois-Israel formalism
to the modified Schwarzschild metric and show that exotic matter is required at
the throat to keep the wormhole stable. We then study the stability analysis of
the wormhole by considering phantom-energy for the exotic matter, generalized
Chaplygin gas (GCG), and the linearized stability analysis. It is argued that,
quantum corrections can affect the stability domain of the wormhole.


title: On the zero forcing number of corona and lexicographic product of graphs

abstract:
  The zero forcing number of a graph $G$, denoted by $Z(G)$, is the minimum
cardinality of a set $S$ of black vertices (where vertices in $V(G)\setminus S$
are colored white) such that $V(G)$ is turned black after finitely many
applications of $"$the color change rule$"$: a white vertex is turned black if
it is the only white neighbor of a black vertex. In this paper, we study the
zero forcing number of corona product, $G\odot H$ and lexicographic product,
$G\circ H$ of two graphs $G$ and $H$. It is shown that if $G$ and $H$ are
connected graphs of order $n_{1}\geq2$ and $n_{2}\geq2$ respectively, then
$Z(G\odot ^{k}H)=Z(G\odot ^{k-1}H)+n_{1}(n_{2}+1)^{k-1}Z(H)$, where
$G\odot^{k}H=(G\odot^{k-1}H)\odot H$. Also, it is shown that for a connected
graph $G$ of order $n\geq 2$ and an arbitrary graph $H$ containing $l\geq 1$
components $H_{1},H_{2}, \cdots,H_{l}$ with $|V(H_{i})|=m_{i}\geq 2$, $1\leq
i\leq l$, $(n-1)l+\sum\limits_{i=1}^l m_{i}\leq Z(G\circ H)\leq
n(\sum\limits_{i=1}^{l}m_{i})-l$.


title: Orthogonal Design of Cyclic Block Filtered Multitone Modulation

abstract:
  The orthogonal design of a Cyclic Block Filtered Multititone Modulation
(CB-FMT) system is addressed. CB-FMT is a filter bank modulation scheme that
uses frequency confined prototype pulses, similarly to Filtered Multitone
Modulation (FMT). Differently from FMT, where the linear convolution is used,
the cyclic convolution is exploited in CB-FMT. This allows to efficiently
implement the system via a concatenation of discrete Fourier transforms (DFT).
The necessary and sufficient orthogonality conditions are derived in time
domain and frequency domain. Then, these conditions are expressed in matrix
form and the prototype pulse coefficients are parameterized with
hyper-spherical coordinates. The effect of a linear time-variant transmission
medium is discussed. In such a scenario, the optimal filter bank orthogonal
design is considered with the objective of maximizing either the
in-band-to-out-band sub-channel energy ratio or the achievable rate. Numerical
results and comparisons show the performance improvements attainable with
several designed optimal pulses also w.r.t. the use of the baseline
root-raised-cosine pulse.


title:
Chiral symmetry restoration in heavy-ion collisions at intermediate
  energies

abstract:
  We study the effect of the chiral symmetry restoration (CSR) on heavy-ion
collisions observables in the energy range $\sqrt{s_{NN}}$=3-20 GeV within the
Parton-Hadron-String Dynamics (PHSD) transport approach. The PHSD includes the
deconfinement phase transition as well as essential aspects of CSR in the dense
and hot hadronic medium, which are incorporated in the Schwinger mechanism for
the hadronic particle production. We adopt different parametrizations of the
nuclear equation of state from the non-linear $\sigma-\omega$ model, which
enter in the computation of the quark scalar density for the CSR mechanism, in
order to estimate the uncertainty in our calculations.


title: Cycles of each even lengths in balanced bipartite digraphs

abstract:
  Let $D$ be a strongly connected balanced bipartite directed graph of order
$2a\geq 4$. Let $x,y$ be distinct vertices in $D$. $\{x,y\}$ dominates a vertex
$z$ if $x\rightarrow z$ and $y\rightarrow z$; in this case, we call the pair
$\{x,y\}$ dominating. In this paper we prove:
  (i). If $a\geq 4$ and $ max\{d(x), d(y)\}\geq 2a-1$ for every dominating pair
of vertices $\{x,y\}$, $D$ then contains a cycle of length $2a-2$ or $D$ is a
directed cycle.
  (ii). If $D$ contains a cycle of length $2a-2\geq 6$ and $max \{d(x),
d(y)\}\geq 2a-2$ for every dominating pair of vertices $\{x,y\}$, then for any
$k$, $1\leq k\leq a-1$, $D$ contains a cycle of length $2k$.
  (iii). If $a\geq 4$ and $ max\{d(x), d(y)\}\geq 2a-1$ for every dominating
pair of vertices $\{x,y\}$, then for every $k$, $1\leq k\leq a$, $D$ contains a
cycle of length $2k$ unless $D$ is isomorphic to only one exceptional digraph
of order eight.


title:
Cluster size distributions of extreme values for the Poisson-Voronoi
  tessellation

abstract:
  We consider the Voronoi tessellation based on a homogeneous Poisson point
process in $\mathbf{R}^{d}$. For a geometric characteristic of the cells (e.g.
the inradius, the circumradius, the volume), we investigate the point process
of the nuclei of the cells with large values. Conditions are obtained for the
convergence in distribution of this point process of exceedances to a
homogeneous compound Poisson point process. We provide a characterization of
the asymptotic cluster size distribution which is based on the Palm version of
the point process of exceedances. This characterization allows us to compute
efficiently the values of the extremal index and the cluster size probabilities
by simulation for various geometric characteristics. The extension to the
Poisson-Delaunay tessellation is also discussed.


title: Difference Index of Quasi-regular Difference Algebraic Systems

abstract:
  This paper is devoted to studying difference indices of quasi-regular
difference algebraic systems. We give the definition of difference indices
through a family of pseudo-Jacobian matrices. Some properties of difference
indices are proved. In particular, a Jacobi-type upper bound for the sum of the
order and the difference index is given. As applications, an upper bound of the
Hilbert-Levin regularity and an upper bound of the order for difference ideal
membership problem are deduced.


title: Designing a High Performance Parallel Personal Cluster

abstract:
  Today, many scientific and engineering areas require high performance
computing to perform computationally intensive experiments. For example, many
advances in transport phenomena, thermodynamics, material properties,
computational chemistry and physics are possible only because of the
availability of such large scale computing infrastructures. Yet many challenges
are still open. The cost of energy consumption, cooling, competition for
resources have been some of the reasons why the scientific and engineering
communities are turning their interests to the possibility of implementing
energy-efficient servers utilizing low-power CPUs for computing-intensive
tasks. In this paper we introduce a novel approach, which was recently
presented at Linux Conference Europe 2015, based on the Beowulf concept and
utilizing single board computers (SBC). We present a low-energy consumption
architecture capable to tackle heavily demanding scientific computational
problems. Additionally, our goal is to provide a low cost personal solution for
scientists and engineers. In order to evaluate the performance of the proposed
architecture we ran several standard benchmarking tests. Furthermore, we assess
the reliability of the machine in real life situations by performing two
benchmark tools involving practical TCAD for physicist and engineers in the
semiconductor industry.


title: Hypertoric manifolds and hyperK\"ahler moment maps

abstract:
  We discuss various aspects of moment map geometry in symplectic and
hyperK\"ahler geometry. In particular, we classify complete hyperK\"ahler
manifolds of dimension $4n$ with a tri-Hamiltonian action of a torus of
dimension $n$, without any assumption on the finiteness of the Betti numbers.
As a result we find that the hyperK\"ahler moment in these cases has connected
fibres, a property that is true for symplectic moment maps, and is surjective.
New examples of hypertoric manifolds of infinite topological type are produced.
We provide examples of non-Abelian tri-Hamiltonian group actions of connected
groups on complete hyperK\"ahler manifolds such that the hyperK\"ahler moment
map is not surjective and has some fibres that are not connected. We also
discuss relationships to symplectic cuts, hyperK\"ahler modifications and
implosion constructions.


title: Why do some cores remain starless ?

abstract:
  Physical conditions that could render a core starless(in the local Universe)
is the subject of investigation in this work. To this end we studied the
evolution of four starless cores, B68, L694-2, L1517B, L1689, and L1521F, a
VeLLO. The density profile of a typical core extracted from an earlier
simulation developed to study core-formation in a molecular cloud was used for
the purpose. We demonstrate - (i) cores contracted in quasistatic manner over a
timescale on the order of $\sim 10^{5}$ years. Those that remained starless did
briefly acquire a centrally concentrated density configuration that mimicked
the density profile of a unstable Bonnor Ebert sphere before rebounding, (ii)
three of our test cores viz. L694-2, L1689-SMM16 and L1521F remained starless
despite becoming thermally super-critical. On the contrary B68 and L1517B
remained sub-critical; L1521F collapsed to become a VeLLO only when gas-cooling
was enhanced by increasing the size of dust-grains. This result is robust, for
other cores viz. B68, L694-2, L1517B and L1689 that previously remained
starless could also be similarly induced to collapse. Our principle conclusions
are : (a) acquiring the thermally super-critical state does not ensure that a
core will necessarily become protostellar, (b) potentially star-forming cores
(VeLLO L1521F here), could be experiencing coagulation of dust-grains that must
enhance the gas-dust coupling and in turn lower the gas temperature, thereby
assisting collapse. This hypothesis appears to have some observational support,
and (c) depending on its dynamic state at any given epoch, a core could appear
to be pressure-confined, gravitationally/virially bound, suggesting that
gravitational/virial boundedness of a core is insufficient to ensure it will
form stars, though it is crucial for gas in a contracting core to cool
efficiently so it can collapse further to become protostellar.


title: Reducible means and reducible inequalities

abstract:
  It is well-known that if a real valued function acting on a convex set
satisfies the $n$-variable Jensen inequality, for some natural number $n\geq
2$, then, for all $k\in\{1,\dots, n\}$, it fulfills the $k$-variable Jensen
inequality as well. In other words, the arithmetic mean and the Jensen
inequality (as a convexity property) are both reducible. Motivated by this
phenomenon, we investigate this property concerning more general means and
convexity notions. We introduce a wide class of means which generalize the
well-known means for arbitrary linear spaces and enjoy a so-called reducibility
property. Finally, we give a sufficient condition for the reducibility of the
$(M,N)$-convexity property of functions and also for H\"older--Minkowski type
inequalities.


title:
Predicting polarization signatures for double-detonation and
  delayed-detonation models of Type Ia supernovae

abstract:
  Calculations of synthetic spectropolarimetry are one means to test
multi-dimensional explosion models for Type Ia supernovae. In a recent paper,
we demonstrated that the violent merger of a 1.1 and 0.9 M$_{\odot}$ white
dwarf binary system is too asymmetric to explain the low polarization levels
commonly observed in normal Type Ia supernovae. Here, we present polarization
simulations for two alternative scenarios: the sub-Chandrasekhar mass
double-detonation and the Chandrasekhar mass delayed-detonation model.
Specifically, we study a two-dimensional double-detonation model and a
three-dimensional delayed-detonation model, and calculate polarization spectra
for multiple observer orientations in both cases. We find modest polarization
levels ($<$ 1 per cent) for both explosion models. Polarization in the
continuum peaks at $\sim$ 0.1$-$0.3 per cent and decreases after maximum light,
in excellent agreement with spectropolarimetric data of normal Type Ia
supernovae. Higher degrees of polarization are found across individual spectral
lines. In particular, the synthetic Si ii {\lambda}6355 profiles are polarized
at levels that match remarkably well the values observed in normal Type Ia
supernovae, while the low degrees of polarization predicted across the O i
{\lambda}7774 region are consistent with the non-detection of this feature in
current data. We conclude that our models can reproduce many of the
characteristics of both flux and polarization spectra for well-studied Type Ia
supernovae, such as SN 2001el and SN 2012fr. However, the two models considered
here cannot account for the unusually high level of polarization observed in
extreme cases such as SN 2004dt.


title:
On the classification of contact metric $(k,\mu)$-spaces via tangent
  hyperquadric bundles

abstract:
  We classify locally the contact metric (k,mu)-spaces whose Boeckx invariant
is $\le -1$ as tangent hyperquadric bundles of Lorentzian space forms.


title: Configurations of lines in space and combinatorial rigidity

abstract:
  Let $L$ be a sequence $(\ell_1,\ell_2,\ldots,\ell_n)$ of $n$ lines in
$\mathbb{C}^3$. We define the {\it intersection graph} $G_L=([n],E)$ of $L$,
where $[n]:=\{1,\ldots, n\}$, and with $\{i,j\}\in E$ if and only if $i\neq j$
and the corresponding lines $\ell_i$ and $\ell_j$ intersect, or are parallel
(or coincide). For a graph $G=([n],E)$, we say that a sequence $L$ is a {\it
realization} of $G$ if $G\subset G_L$. One of the main results of this paper is
to provide a combinatorial characterization of graphs $G=([n],E)$ that have the
following property: For every {\it generic} realization $L$ of $G$ that
consists of $n$ pairwise distinct lines, we have $G_L=K_n$, in which case the
lines of $L$ are either all concurrent or all coplanar.
  The general statements that we obtain about lines, apart from their
independent interest, turns out to be closely related to the notion of graph
rigidity. The connection is established due to the so-called Elekes--Sharir
framework, which allows us to transform the problem into an incidence problem
involving lines in three dimensions. By exploiting the geometry of contacts
between lines in 3D, we can obtain alternative, simpler, and more precise
characterizations of the rigidity of graphs.


title: Phase transitions in edge-weighted exponential random graphs

abstract:
  The exponential family of random graphs represents an important and
challenging class of network models. Despite their flexibility, conventionally
used exponential random graphs have one shortcoming. They cannot directly model
weighted networks as the underlying probability space consists of simple graphs
only. Since many substantively important networks are weighted, this limitation
is especially problematic. We extend the existing exponential framework by
proposing a generic common distribution for the edge weights and rigorously
analyze the associated phase transitions and critical phenomena. We then apply
these general results to get concrete answers in exponential random graph
models where the edge weights are uniformly distributed.


title: Bidirectional invisibility in Kramers-Kronig optical media

abstract:
  A broad class of planar dielectric media with complex permittivity profiles
that are fully invisible, for both left and right incidence sides, is
introduced. Such optical media are locally isotropic, non-magnetic and belong
to the recently discovered class of Kramers-Kronig media [{\it Nature Photon.}
9, 436 (2015)], i.e. the spatial profiles of the real and imaginary parts of
the dielectric permittivity are related each other by a Hilbert transform. The
transition from unidirectional to bidirectional invisibility, and the
possibility to realize sharp reflection above a cut-off incidence angle, are
also discussed.


title:
Averaging theory at any order for computing limit cycles of
  discontinuous piecewise differential systems with many zones

abstract:
  This work is devoted to study the existence of periodic solutions for a
family of discontinuous differential systems $Z(x,y;\epsilon)$ with many zones.
We show that for $\epsilon$ sufficiently small the averaged functions at any
order control the existence of crossing limit cycles for systems in this
family. We also provide some examples dealing with nonlinear centers.


title:
Amplification of matter rogue waves and breathers in
  quasi-two-dimensional Bose-Einstein condensates

abstract:
  We construct rogue wave and breather solutions of a quasi-two-dimensional
Gross-Pitaevskii equation with a time-dependent interatomic interaction and
external trap. We show that the trapping potential and an arbitrary functional
parameter that present in the similarity transformation should satisfy a
constraint for the considered equation to be integrable and yield the desired
solutions. We consider two different forms of functional parameters and
investigate how the density of the rogue wave and breather profiles vary with
respect to these functional parameters. We also construct vector localized
solutions of a two coupled quasi-two-dimensional Bose-Einstein condensate
system. We then investigate how the vector localized density profiles modify in
the constant density background with respect to the functional parameters. Our
results may help to manipulate matter rogue waves experimentally in the
two-dimensional Bose-Einstein condensate systems.


title: Virtual pro-$p$ properties of 3-manifold groups

abstract:
  We answer a question of Aschenbrenner and Friedl regarding virtual
$p$-efficiency for 3-manifold groups. We then study conjugacy $p$-separability
and prove results for Fuchsian groups, Seifert fibre spaces and graph
manifolds.


title:
Hidden and coexistent magnetic phases in Kondo-type Cerium Hexaboride
  (CeB6)

abstract:
  The heavy fermion material CeB6 shows hidden magnetic ordered phases. Besides
well-known Ferromagnetic(FM) and Antiferromagnetic(AFM) phases, CeB6 is
speculated to form a unique antiferroquadrupolar (AFQ) phase that is orbital in
nature. Hidden from many characterization methods that cannot assess orbital
ordering, debate continue on the origins. From electronic-structure
calculations, we find that these three phases are energetically almost
degenerate, suggesting that magnetic domain walls form, possibly with defect
boundaries. Only calculations with spin-orbit coupling reproduce most band
structures and Fermi surfaces, as found in experiment, indicating the
importance of crystal-field splitting. Simulated ionization peaks, i.e., Ce f0
and f1 states, also agree with photoemission data. Small pressures stabilizes
the AFM over the FM phase, which is the observed phase at low temperature. We
propose to realize such small physical pressure under various situations e.g.
effect of intrinsic defects such as vacancies, antisites, surface effects etc.


title: Kripke Semantics for Fuzzy Logics

abstract:
  Kripke frames (and models) provide a suitable semantics for sub-classical
logics, for example Intuitionistic Logic (of Brouwer and Heyting) axiomatizes
the reflexive and transitive Kripke frames (with persistent satisfaction
relations), and the Basic Logic (of Visser) axiomatizes transitive Kripke
frames (with persistent satisfaction relations). Here, we investigate whether
Kripke frames/models could provide a semantics for fuzzy logics. For each axiom
of the Basic Fuzzy Logic, necessary and sufficient conditions are sought for
Kripke frames/models which satisfy them. It turns out that the only fuzzy
logics (logics containing the Basic Fuzzy Logic) which are sound and complete
with respect to a class of Kripke frames/models are the extensions of the
G\"odel Logic (or the super-intuitionistic logic of Dummett), indeed this logic
is sound and strongly complete with respect to reflexive, transitive and
connected (linear) Kripke frames (with persistent satisfaction relations). This
provides a semantic characterization for the G\"odel Logic among
(propositional) fuzzy logics.


title: Generalized Sampling in Julia

abstract:
  Generalized sampling is a numerically stable framework for obtaining
reconstructions of signals in different bases and frames from their samples. In
this paper, we will introduce a carefully documented toolbox for performing
generalized sampling in Julia. Julia is a new language for technical computing
with focus on performance, which is ideally suited to handle the large size
problems often encountered in generalized sampling. The toolbox provides
specialized solutions for the setup of Fourier bases and wavelets. The
performance of the toolbox is compared to existing implementations of
generalized sampling in MATLAB.


title:
Spatial asymptotics for the parabolic Anderson model driven by a
  Gaussian rough noise

abstract:
  The aim of this paper is to establish the almost sure asymptotic behavior as
the space variable becomes large, for the solution to the one spatial
dimensional stochastic heat equation driven by a Gaussian noise which is white
in time and which has the covariance structure of a fractional Brownian motion
with Hurst parameter greater than 1/4 and less than 1/2 in the space variable.


title: Topological equivalence to a projection

abstract:
  We present a necessary and sufficient condition for the topological
equivalence of a continuous function on a plane to a projection onto one of
coordinates.


title:
Simultaneous Measurement of Resistively and Optically Detected Nuclear
  Magnetic Resonance in the $\nu=2/3$ Fractional Quantum Hall Regime

abstract:
  We observe nuclear magnetic resonance (NMR) in the fractional quantum Hall
regime at Landau level filling factor $\nu=2/3$ from simultaneous measurement
of longitudinal resistance and photoluminescence (PL). The dynamic nuclear spin
polarization is induced by applying a huge electronic current at the spin phase
transition point of $\nu=2/3$. The NMR spectra obtained from changes in
resistance and PL intensity are qualitatively the same; that is, the Knight
shift (spin polarized region) and zero-shift (spin unpolarized region)
resonances are observed in both. The observed change in PL intensity is
interpreted as a consequence of the trion scattering induced by polarized
nuclear spins. We conclude that both detection methods probe almost the same
local phenomena.


title:
Regularity of partial differential operators in ultradifferentiable
  spaces and Wigner type transforms

abstract:
  We study the behaviour of linear partial differential operators with
polynomial coefficients via a Wigner type transform. In particular, we obtain
some results of regularity in the Schwartz space $\mathcal S$ and in the space
${\mathcal S}_\omega$ as introduced by Bj\"orck for weight functions $\omega$.
Several examples are discussed in this new setting.


title: Torelli theorem for the parabolic Deligne-Hitchin moduli space

abstract:
  We prove that, given the isomorphism class of the parabolic Deligne-Hitchin
moduli space over a smooth projective curve, we can recover the isomorphism
class of the curve and the parabolic points.


title:
Homeotopy groups of rooted tree like non-singular foliations on the
  plane

abstract:
  Let $F$ be a non-singular foliation on the plane with all leaves being closed
subsets, $H^{+}(F)$ be the group of homeomorphisms of the plane which maps
leaves onto leaves endowed with compact open topology, and $H^{+}_{0}(F)$ be
the identity path component of $H^{+}(F)$. The quotient $\pi_0 H^{+}(F) =
H^{+}(F)/H^{+}_{0}(F)$ is an analogue of a mapping class group for foliated
homeomorphisms. We will describe the algebraic structure of $\pi_0 H^{+}(F)$
under an assumption that the corresponding space of leaves of $F$ has a
structure similar to a rooted tree of finite diameter.


title: On the existence of closed magnetic geodesics via symplectic reduction

abstract:
  Let $(M,g)$ be a closed Riemannian manifold and $\sigma$ be a closed 2-form
on $M$ representing an integer cohomology class. In this paper, using
symplectic reduction, we show how the problem of existence of closed magnetic
geodesics for the magnetic flow of the pair $(g,\sigma)$ can be interpreted as
a critical point problem for a Rabinowitz-type action functional defined on the
cotangent bundle $T^*E$ of a suitable $S^1$-bundle $E$ over $M$ or,
equivalently, as a critical point problem for a Lagrangian-type action
functional defined on the free loopspace of $E$. We then study the relation
between the stability property of energy hypersurfaces in $(T^*M,dp\wedge
dq+\pi^*\sigma)$ and of the corresponding codimension 2 coisotropic
submanifolds in $(T^*E,dp\wedge dq)$ arising via symplectic reduction. Finally,
we reprove the main result of [9] in this setting.


title:
Cosmological bounces and Lorentzian wormholes in Galileon theories with
  an extra scalar field

abstract:
  We study whether it is possible to design a "classical" spatially flat
bouncing cosmology or a static, spherically symmetric asymptotically flat
Lorentzian wormhole in cubic Galileon theories interacting with an extra scalar
field. We show that bouncing models are always plagued with gradient
instabilities, while there are always ghosts in wormhole backgrounds.


title: Insurance valuation: a computable multi-period cost-of-capital approach

abstract:
  We present an approach to market-consistent multi-period valuation of
insurance liability cash flows based on a two-stage valuation procedure. First,
a portfolio of traded financial instrument aimed at replicating the liability
cash flow is fixed. Then the residual cash flow is managed by repeated
one-period replication using only cash funds. The latter part takes capital
requirements and costs into account, as well as limited liability and risk
averseness of capital providers. The cost-of-capital margin is the value of the
residual cash flow. We set up a general framework for the cost-of-capital
margin and relate it to dynamic risk measurement. Moreover, we present explicit
formulas and properties of the cost-of-capital margin under further assumptions
on the model for the liability cash flow and on the conditional risk measures
and utility functions. Finally, we highlight computational aspects of the
cost-of-capital margin, and related quantities, in terms of an example from
life insurance.


title: A Moser type inequality for Bessel Laplace equations and applications

abstract:
  In this paper, we study Bessel operators and Bessel Laplace equations studied
by Weinstein, Huber, and related the harmonic function theory introduced by
Muckenhoupt--Stein. We establish the Moser type inequality for these harmonic
functions, which is missing in this setting before. We then apply it to give a
direct proof for the equivalence of characterizations of the Hardy spaces
associated to Bessel operator via non-tangential maximal function and radial
maximal function defined in terms of the Poisson semigroup.


title: Asymmetry and structural information in preferential attachment graphs

abstract:
  Graph symmetries intervene in diverse applications, from enumeration, to
graph structure compression, to the discovery of graph dynamics (e.g., node
arrival order inference). Whereas Erd\H{o}s-R\'enyi graphs are typically
asymmetric, real networks are highly symmetric. So a natural question is
whether preferential attachment graphs, where in each step a new node with $m$
edges is added, exhibit any symmetry. In recent work it was proved that
preferential attachment graphs are symmetric for $m=1$, and there is some
non-negligible probability of symmetry for $m=2$. It was conjectured that these
graphs are asymmetric when $m \geq 3$. We settle this conjecture in the
affirmative, then use it to estimate the structural entropy of the model. To do
this, we also give bounds on the number of ways that the given graph structure
could have arisen by preferential attachment. These results have further
implications for information theoretic problems of interest on preferential
attachment graphs.


title:
Universality of nucleon-nucleon short-range correlations: the
  factorization property of the nuclear wave function, the relative and
  center-of-mass momentum distributions, and the nuclear contacts

abstract:
  The two-nucleon momentum distributions have been calculated for nuclei up to
A=40 and various values of the relative and center-of-mass momenta and angle
between them. For complex nuclei a parameter-free linked-cluster expansion,
based upon a realistic local two-nucleon interaction of the Argonne family and
variational wave function featuring central, tensor, spin and iso-spin
correlations, has been used. The obtained results show that: 1) independently
of the mass number A, at values of the relative momentum k_rel> 2 fm^{-1} the
proton-neutron momentum distributions for back-to-back (BB) nucleons (K_cm=0)
exhibit the factorization property n_A^{pn}(k_rel,K_cm=0)=C_A^{pn} n_D(k_rel)
n_{cm}^{pn}(K_cm=0), where n_D is the deuteron momentum distribution,
n_{cm}^{pn}(K_{cm}=0) the momentum distribution of the c.m. motion of the pair
and C_A^{pn} the nuclear contact measuring the number of BB pn pairs with
deuteron-like momenta; 2) the values of the proton-neutron nuclear contact
C_A^{pn} are obtained in a model-independent way from the ratio
n_A^{pn}(k_rel,K_cm=0)/n_D(k_rel) n_{cm}^{pn}(K_cm=0); 3) also the
K_cm-integrated pn momentum distributions divided by the deuteron momentum
distribution exhibits a constant behavior equal to C_A^{pn}, but only at very
high values of k_{rel}> 3.5fm^{-1}, where the relative momentum distribution is
entirely governed by BB short-range correlated nucleons; 4) the absolute value
of the number of pn and pp short-range correlated pairs is calculated,
illustrating that the high values (K_cm>1 fm^{-1}) of the pair c.m. momentum
appreciably reduce the dominance of the pn over pp pairs produced by the tensor
force when K_cm=0; 5) calculations are in good agreement with the VMC
calculations for light nuclei and with available experimental on the processes
A(e,e'pn)X and A(e,e'pp)X.


title: Language-integrated provenance

abstract:
  Provenance, or information about the origin or derivation of data, is
important for assessing the trustworthiness of data and identifying and
correcting mistakes. Most prior implementations of data provenance have
involved heavyweight modifications to database systems and little attention has
been paid to how the provenance data can be used outside such a system. We
present extensions to the Links programming language that build on its support
for language-integrated query to support provenance queries by rewriting and
normalizing monadic comprehensions and extending the type system to distinguish
provenance metadata from normal data. The main contribution of this article is
to show that the two most common forms of provenance can be implemented
efficiently and used safely as a programming language feature with no changes
to the database system.


title: On the conjecture of Wood and projective homogeneity

abstract:
  In 2005 Kawamura and Rambla, independently, constructed a metric
counterexample to Wood's Conjecture from 1982. We exhibit a new nonmetric
counterexample of a space $\hat L$, such that $C_0(\hat L,\mathbb{C})$ is
almost transitive, and show that it is distinct from a nonmetric space whose
existence follows from the work of Greim and Rajagopalan in 1997. Up to our
knowledge, this is only the third known counterexample to Wood's Conjecture. We
also show that, contrary to what was expected, if a one-point compactification
of a space $X$ is R.H. Bing's pseudo-circle then $C_0(X,\mathbb{C})$ is not
almost transitive, for a generic choice of points. Finally, we point out close
relation of these results on Wood's conjecture to a work of Irwin and Solecki
on projective Fra\"iss\'e limits and projective homogeneity of the pseudo-arc
and, addressing their conjecture, we show that the pseudo-circle is not
approximately projectively homogeneous.


title:
Using baseline-dependent window functions for data compression and
  field-of-interest shaping in radio interferometry

abstract:
  In radio interferometry, observed visibilities are intrinsically sampled at
some interval in time and frequency. Modern interferometers are capable of
producing data at very high time and frequency resolution; practical limits on
storage and computation costs require that some form of data compression be
imposed. The traditional form of compression is a simple averaging of the
visibilities over coarser time and frequency bins. This has an undesired side
effect: the resulting averaged visibilities "decorrelate", and do so
differently depending on the baseline length and averaging interval. This
translates into a non-trivial signature in the image domain known as
"smearing", which manifests itself as an attenuation in amplitude towards
off-centre sources. With the increasing fields of view and/or longer baselines
employed in modern and future instruments, the trade-off between data rate and
smearing becomes increasingly unfavourable. In this work we investigate
alternative approaches to low-loss data compression. We show that averaging of
the visibility data can be treated as a form of convolution by a boxcar-like
window function, and that by employing alternative baseline-dependent window
functions a more optimal interferometer smearing response may be induced. In
particular, we show improved amplitude response over a chosen field of
interest, and better attenuation of sources outside the field of interest. The
main cost of this technique is a reduction in nominal sensitivity; we
investigate the smearing vs. sensitivity trade-off, and show that in certain
regimes a favourable compromise can be achieved. We show the application of
this technique to simulated data from the Karl G. Jansky Very Large Array (VLA)
and the European Very-long-baseline interferometry Network (EVN).


title: Magnetar-like activity from the central compact object in the SNR RCW103

abstract:
  The 6.67 hr periodicity and the variable X-ray flux of the central compact
object (CCO) at the center of the SNR RCW 103, named 1E 161348-5055, have been
always difficult to interpret within the standard scenarios of an isolated
neutron star or a binary system. On 2016 June 22, the Burst Alert Telescope
(BAT) onboard Swift detected a magnetar-like short X-ray burst from the
direction of 1E 161348-5055, also coincident with a large long-term X-ray
outburst. Here we report on Chandra, NuSTAR, and Swift (BAT and XRT)
observations of this peculiar source during its 2016 outburst peak. In
particular, we study the properties of this magnetar-like burst, we discover a
hard X-ray tail in the CCO spectrum during outburst, and we study its long-term
outburst history (from 1999 to July 2016). We find the emission properties of
1E 161348-5055 consistent with it being a magnetar. However in this scenario,
the 6.67 hr periodicity can only be interpreted as the rotation period of this
strongly magnetized neutron star, which therefore represents the slowest pulsar
ever detected, by orders of magnitude. We briefly discuss the viable slow-down
scenarios, favoring a picture involving a period of fall-back accretion after
the supernova explosion, similarly to what is invoked (although in a different
regime) to explain the "anti-magnetar" scenario for other CCOs.


title: A note on constructive treatment of eigenvectors

abstract:
  The eigenvalue problem plays a central role in linear algebra and its
applications in control and optimization methods. In particular, many matrix
decompositions rely upon computation of eigenvalue-eigenvector pairs, such as
diagonal or Jordan normal forms. Unfortunately, numerical algorithms computing
eigenvectors are prone to errors. Due to uncomputability of eigenpairs,
perturbation theory and various regularization techniques only help if the
matrix at hand possesses certain properties such as the absence of non-zero
singular values, or the presence of a distinguishable gap between the large and
small singular values. Posing such a requirement might be restrictive in some
practical applications. In this note, we propose an alternative treatment of
eigenvectors which is approximate and constructive. In comparison to classical
eigenvectors whose computation is often prone to numerical instability, a
constructive treatment allows addressing the computational uncertainty in a
controlled way.


title: General Sub-packetized Access-Optimal Regenerating Codes

abstract:
  This paper presents a novel construction of $(n,k,d=n-1)$ access-optimal
regenerating codes for an arbitrary sub-packetization level $\alpha$ for exact
repair of any systematic node. We refer to these codes as general
sub-packetized because we provide an algorithm for constructing codes for any
$\alpha$ less than or equal to $r^{\lceil \frac{k}{r} \rceil}$ where
$\frac{k}{r}$ is not necessarily an integer. This leads to a flexible
construction of codes for different code rates compared to existing approaches.
We derive the lower and the upper bound of the repair bandwidth. The repair
bandwidth depends on the code parameters and $\alpha$. The repair process of a
failed systematic node is linear and highly parallelized, which means that a
set of $\lceil \frac{\alpha}{r} \rceil$ symbols is independently repaired first
and used along with the accessed data from other nodes to recover the remaining
symbols.


title: Using Recurrent Neural Network for Learning Expressive Ontologies

abstract:
  Recently, Neural Networks have been proven extremely effective in many
natural language processing tasks such as sentiment analysis, question
answering, or machine translation. Aiming to exploit such advantages in the
Ontology Learning process, in this technical report we present a detailed
description of a Recurrent Neural Network based system to be used to pursue
such goal.


title:
General Rotational Surfaces in Pseudo-Euclidean 4-Space with Neutral
  Metric

abstract:
  We define general rotational surfaces of elliptic and hyperbolic type in the
pseudo-Euclidean 4-space with neutral metric which are analogous to the general
rotational surfaces of C. Moore in the Euclidean 4-space. We study Lorentz
general rotational surfaces with plane meridian curves and give the complete
classification of minimal general rotational surfaces of elliptic and
hyperbolic type, general rotational surfaces with parallel normalized mean
curvature vector field, flat general rotational surfaces, and general
rotational surfaces with flat normal connection.


title:
Magnetic phase diagrams in the H-T plane of the magnetically strongest
  sigma-phase Fe-V compounds

abstract:
  Magnetization measurements were performed on two sigma-phase samples of
Fe(100-x)V(x) (x=35.5, 34.1) vs. temperature, T, and in DC magnetic field, of
various amplitudes. Using three characteristic temperatures, magnetic phase
diagrams in the H-T plane have been designed testifying to a re-entrant
character of magnetism. The ground magnetic state, a spin glass (SG), was
evidenced to be composed of two sub phases: one with a weak irreversibility and
the other with a strong irreversibility. Two critical lines were reconstructed
within the SG state. Both of them show a crossover from the Gabay-Toulouse
behavior (low field) to a linear and/or quasi-Almeida-Touless behavior. A
strong difference in the effect of the applied magnetic field on the SG phase
in the two samples was revealed.


title: Height four formal groups with quadratic complex multiplication

abstract:
  We construct spectral sequences for computing the cohomology of automorphism
groups of formal groups with complex multiplication by a $p$-adic number ring.
We then compute the cohomology of the group of automorphisms of a height four
formal group law which commute with complex multiplication by the ring of
integers in the field $\mathbb{Q}_p(\sqrt{p})$, for primes $p>5$. This is a
large subgroup of the height four strict Morava stabilizer group. The group
cohomology of this group of automorphisms turns out to have cohomological
dimension $8$ and total rank $80$. We then run the $K(4)$-local $E_4$-Adams
spectral sequence to compute the homotopy groups of the homotopy fixed-point
spectrum of this group's action on the Lubin-Tate/Morava spectrum $E_4$.


title:
The Effects of Minimal Length, Maximal Momentum and Minimal Momentum in
  Entropic Force

abstract:
  In this paper, the modified entropic force law is studied by using a new kind
of generalized uncertainty principle which contains a minimal length, a minimal
momentum and a maximal momentum. Firstly, the quantum corrections to the
thermodynamics of a black hole is investigated. Then, according to Verlinde's
theory, the generalized uncertainty principle (GUP) corrected entropic force is
obtained. The result shows that the GUP corrected entropic force is related not
only to the properties of the black holes, but also to the Planck length and
the dimensionless constants $\alpha _{\rm{0}}$ and $\beta _{\rm{0}}$. Moreover,
based on the GUP corrected entropic force, we also derive the modified
Einstein's field equation (EFE) and the modified Friedmann equation.


title: The probl\`eme des m\'enages revisited

abstract:
  We present an alternative proof to the Touchard-Kaplansky formula for the
probl\`eme des m\'enages, which, we believe, is simpler than the extant ones
and is in the spirit of the elegant original proof by Kaplansky (1943). About
the latter proof, Bogart and Doyle (1986) argued that despite its cleverness,
suffered from opting to give precedence to one of the genders for the couples
involved (Bogart and Doyle supplied an elegant proof that avoided such
gender-dependent bias).


title:
Inducing and detecting collective population inversions of M\"ossbauer
  nuclei

abstract:
  Up to now, experiments involving M\"ossbauer nuclei driven by x-rays have
been restricted to the low-excitation regime. Here, a setup is proposed which
promises significant excitation, ideally exceeding full inversion of the
nuclear ensemble, at x-ray light sources under construction. We further
introduce a method to experimentally verify such inversions, in which
population inversions manifest themselves in symmetry flips of suitably
recorded spectra. It neither requires per-shot spectra of the incoming x-ray
pulses, nor absolute measurements of the scattered light intensity.


title:
Improvement of radiopurity level of enriched $^{116}$CdWO$_4$ and
  ZnWO$_4$ crystal scintillators by recrystallization

abstract:
  As low as possible radioactive contamination of a detector plays a crucial
role to improve sensitivity of a double beta decay experiment. The radioactive
contamination of a sample of $^{116}$CdWO$_4$ crystal scintillator by thorium
was reduced by a factor $\approx 10$, down to the level 0.01 mBq/kg
($^{228}$Th), by exploiting the recrystallization procedure. The total alpha
activity of uranium and thorium daughters was reduced by a factor $\approx 3$,
down to 1.6 mBq/kg. No change in the specific activity (the total $\alpha$
activity and $^{228}$Th) was observed in a sample of ZnWO$_4$ crystal produced
by recrystallization after removing $\approx 0.4$ mm surface layer of the
crystal.


title:
Algebraic method for group classification of (1+1)-dimensional linear
  Schr\"odinger equations

abstract:
  We carry out the complete group classification of the class of
(1+1)-dimensional linear Schr\"odinger equations with complex-valued
potentials. After introducing the notion of uniformly semi-normalized classes
of differential equations, we compute the equivalence groupoid of the class
under study and show that it is uniformly semi-normalized. More specifically,
each admissible transformation in the class is the composition of a linear
superposition transformation of the corresponding initial equation and an
equivalence transformation of this class. This allows us to apply the new
version of the algebraic method based on uniform semi-normalization and reduce
the group classification of the class under study to the classification of
low-dimensional appropriate subalgebras of the associated equivalence algebra.
The partition into classification cases involves two integers that characterize
Lie symmetry extensions and are invariant with respect to equivalence
transformations.


title: Shortcut to adiabaticity in spinor condensates

abstract:
  We devise a method to shortcut the adiabatic evolution of a spin-1 Bose gas
with an external magnetic field as the control parameter. An initial many-body
state with almost all bosons populating the Zeeman sublevel $m=0$, is evolved
to a final state very close to a macroscopic spin-singlet condensate, a
fragmented state with three macroscopically occupied Zeeman states. The
shortcut protocol, obtained by an approximate mapping to a harmonic oscillator
Hamiltonian, is compared to linear and exponential variations of the control
parameter. We find a dramatic speedup of the dynamics when using the shortcut
protocol.


title: Minimal model for the frustrated spin ladder system BiCu$_2$PO$_6$

abstract:
  To establish the microscopic model of the compound BiCu$_2$PO$_6$ is a
challenging task. Inelastic neutron scattering experiments showed that the
dispersion of this material is non-degenerate suggesting the existence of
anisotropic interactions. Here we present a quantitative description of the
excitation spectrum for BiCu$_2$PO$_6$ on the one-particle level. The solution
of the isotropic frustrated spin ladder by continuous unitary transformations
is the starting point of our approach. Further couplings such as isotropic
interladder couplings and anisotropic interactions are included on the
mean-field level. Our aim is to establish a minimal model built on the symmetry
allowed interactions and to find a set of parameters, which allow us to
describe the low-energy part of the dispersion without assuming unrealistic
couplings.


title: Universe's memory and spontaneous coherence in loop quantum cosmology

abstract:
  The quantum bounce a priori connects several (semi)classical epochs of
Universe evolution, however determining if and how well the semiclassicality is
preserved in this transition is highly nontrivial. We review the present state
of knowledge in that regards in the isotropic sector of loop quantum cosmology.
This knowledge is next extended by studies of an isotropic universe admitting
positive cosmological constant (featuring an infinite chain of large Universe
epochs). It is also shown, that such universe always admits a semiclassical
epoch thanks to spontaneous spontaneous coherence, provided it is semiclassical
in certain constant of motion playing the role of energy.


title:
iMet: A computational tool for structural annotation of unknown
  metabolites from tandem mass spectra

abstract:
  Untargeted metabolomic studies are revealing large numbers of naturally
occurring metabolites that cannot be characterized because their chemical
structures and MS/MS spectra are not available in databases. Here we present
iMet, a computational tool based on experimental tandem mass spectrometry that
could potentially allow the annotation of metabolites not discovered
previously. iMet uses MS/MS spectra to identify metabolites structurally
similar to an unknown metabolite, and gives a net atomic addition or removal
that converts the known metabolite into the unknown one. We validate the
algorithm with 148 metabolites, and show that for 89% of them at least one of
the top four matches identified by iMet enables the proper annotation of the
unknown metabolite. iMet is freely available at http://imet.seeslab.net.


title: Degravitation, Orbital Dynamics and the Effective Barycentre

abstract:
  In this article we present a particular theory of gravity in which Einstein's
field equations are modified by promoting Newton's constant $G$ to a covariant
differential operator $G_\Lambda(\Box_g)$. The general idea was obviously
outlined for the first time in [13-16] and originates from the quest of finding
a mechanism that is able to degravitate the vacuum energy on cosmological
scales. We suggest in this manuscript a precise covariant coupling model which
acts like a high-pass filter with a macroscopic distance filter scale
$\sqrt{\Lambda}$. In the context of this specific theory of gravity we review
some cosmological aspects before we briefly recall the effective relaxed
Einstein equations outlined for the first time in [1]. We present a general
procedure to determine the gravitational potentials for a far away wave zone
field point. Moreover we work out the modified orbital dynamics of a
binary-system as well as the effective 1.5 post-Newtonian barycentre for a
generic $n$-body system. We notice that it is always possible to recover the
corresponding general relativistic results in the limit of vanishing nonlocal
modification parameters.


title:
Deuteron electromagnetic structure functions and polarization properties
  in soft-wall AdS/QCD

abstract:
  We apply a soft-wall AdS/QCD approach to the description of deuteron
structure functions and tensor polarized properties. Present work is a
completion of our previous study on electromagnetic form factors. By the
appropriate choice of two couplings in the effective action we are able to
reproduce both the form factors and structure functions in full consistency
with model-independent constraints set by perturbative QCD. Our framework is
based on a five-dimensional action in AdS space formulated in terms of vector
fields dual to the deuteron and the electromagnetic fields. The AdS fields
depend on four Minkowski and one holographic coordinate $z$. The scale
dependence of the form factors and structure functions is consistent with quark
counting rules implying the $1/Q^{10}$ behavior of the charge form factor
$G_C(Q^2)$, structure functions $A(Q^2)$ and $B(Q^2)$, and the $1/Q^{12}$
behavior of the magnetic $G_M(Q^2)$ and quadrupole $G_Q(Q^2)$ form factors.


title: Citation count distributions for large monodisciplinary journals

abstract:
  Many different citation-based indicators are used by researchers and research
evaluators to help evaluate the impact of scholarly outputs. Although the
appropriateness of individual citation indicators depends in part on the
statistical properties of citation counts, there is no universally agreed
best-fitting statistical distribution against which to check them. The two
current leading candidates are the discretised lognormal and the hooked or
shifted power law. These have been mainly tested on sets of articles from a
single field and year but these collections can include multiple specialisms
that might dilute their properties. This article fits statistical distributions
to 50 large subject-specific journals in the belief that individual journals
can be purer than subject categories and may therefore give clearer findings.
The results show that in most cases the discretised lognormal fits
significantly better than the hooked power law, reversing previous findings for
entire subcategories. This suggests that the discretised lognormal is the more
appropriate distribution for modelling pure citation data. Thus future
analytical investigations of the properties of citation indicators can use the
lognormal distribution to analyse their basic properties. This article also
includes improved software for fitting the hooked power law.


title:
A High-Resolution Multiband Survey of Westerlund 2 With the Hubble Space
  Telescope. II. Mass accretion in the Pre-Main Sequence Population

abstract:
  We present a detailed analysis of the pre-main-sequence (PMS) population of
the young star cluster Westerlund~2 (Wd2), the central ionizing cluster of the
HII region RCW 49, using data from a high resolution multi-band survey with the
Hubble Space Telescope. The data were acquired with the Advanced Camera for
Surveys in the F555W, F814W, and F658N filters and with the Wide Field Camera 3
in the F125W, F160W, and F128N filters. We find a mean age of the region of
1.04+-0.72 Myr. The combination of dereddened F555W and F814W photometry in
combination with F658N photometry allows us to study and identify stars with
H_alpha excess emission. With a careful selection of 240 bona-fide PMS H_alpha
excess emitters we were able to determine their H_alpha luminosity, which has a
mean value L(H_alpha)=1.67 x 10^{-31} erg s^{-1}. Using the PARSEC 1.2S
isochrones to obtain the stellar parameters of the PMS stars we determined a
mean mass accretion rate \dot M_acc=4.43 x 10^{-8} M_sun yr^{-1} per star. A
careful analysis of the spatial dependence of the mass-accretion rate suggests
that this rate is ~25% lower in center of the two density peaks of Wd2 in close
proximity to the luminous OB stars, compared to the Wd2 average. This rate is
higher with increasing distance from the OB stars, indicating that the PMS
accretion disks are being rapidly destroyed by the far-ultra-violet radiation
emitted by the OB population.


title: Inverse scattering problem in turbulent magnetic fluctuations

abstract:
  We apply a particular form of the inverse scattering theory to turbulent
magnetic fluctuations in a plasma. In the present note we develop the theory,
formulate the magnetic fluctuation problem in terms of its electrodynamic
turbulent response function, and reduce it to the solution of a special form of
the famous Gel$'$fand-Levitan-Marchenko equation of quantum mechanical
scattering theory.


title: Two Counterexamples Concerning the Scott Topology on a Partial Order

abstract:
  We construct a complete lattice $Z$ such that the binary supremum function
$\sup:Z\times Z\to Z$ is discontinuous with respect to the product topology on
$Z\times Z$ of the Scott topologies on each copy of $Z$. In addition, we show
that bounded completeness of a complete lattice $Z$ is in general not inherited
by the dcpo $C(X,Z)$ of continuous functions from $X$ to $Z$ where $X$ may be
any topological space and where on $Z$ the Scott topology is considered.


title:
Simplifying amplitudes in Maxwell-Einstein and Yang-Mills-Einstein
  supergravities

abstract:
  This article reviews recent progress in formulating double-copy constructions
for scattering amplitudes in supergravity theories with N=2 supersymmetry in
five and four spacetime dimensions. Particular attention is devoted to infinite
families of Maxwell-Einstein theories with symmetric and homogeneous target
spaces and to Yang-Mills-Einstein theories with compact gauge groups. Extension
of the construction to theories with spontaneously-broken gauge symmetry is
also discussed.


title: Random groups, random graphs and eigenvalues of p-Laplacians

abstract:
  We prove that a random group in the triangular density model has, for density
larger than 1/3, fixed point properties for actions on $L^p$-spaces (affine
isometric, and more generally $(2-2\epsilon)^{1/2p}$-uniformly Lipschitz) with
$p$ varying in an interval increasing with the set of generators. In the same
model, we establish a double inequality between the maximal $p$ for which
$L^p$-fixed point properties hold and the conformal dimension of the boundary.
  In the Gromov density model, we prove that for every $p_0 \in [2, \infty)$
for a sufficiently large number of generators and for any density larger than
1/3, a random group satisfies the fixed point property for affine actions on
$L^p$-spaces that are $(2-2\epsilon)^{1/2p}$-uniformly Lipschitz, and this for
every $p\in [2,p_0]$.
  To accomplish these goals we find new bounds on the first eigenvalue of the
p-Laplacian on random graphs, using methods adapted from Kahn and Szemeredi's
approach to the 2-Laplacian. These in turn lead to fixed point properties using
arguments of Bourdon and Gromov, which extend to $L^p$-spaces previous results
for Kazhdan's Property (T) established by Zuk and Ballmann-Swiatkowski.


title:
The Dixmier-Moeglin equivalence for extensions of scalars and Ore
  extensions

abstract:
  An algebra $A$ satisfies the Dixmier-Moeglin equivalence if we have the
equivalences: $$P~{\rm primitive}\iff P~{\rm rational}\iff P ~{\rm
locally~closed~}\qquad~{\rm for}~P\in {\rm Spec}(A).$$ We study the robustness
of the Dixmier-Moeglin equivalence under extension of scalars and under the
formation of Ore extensions. In particular, we show that the Dixmier-Moeglin
equivalence is preserved under base change for finitely generated complex
noetherian algebras. We also study Ore extensions of finitely generated complex
noetherian algebras $A$. If $T:A\to A$ is either a $\mathbb{C}$-algebra
automorphism or a $\mathbb{C}$-linear derivation of $A$, we say that $T$ is
\emph{frame-preserving} if there exists a finite-dimensional subspace
$V\subseteq A$ that generates $A$ as an algebra such that $T(V)\subseteq V$. We
show that if $A$ is of finite Gelfand-Kirillov dimension and has the property
that all prime ideals of $A$ are completely prime and $A$ satisfies the
Dixmier-Moeglin equivalence then the Ore extension $A[x;T]$ satisfies the
Dixmier-Moeglin equivalence whenever $T$ is a frame-preserving derivation or
automorphism.


title: Symplectic Analysis of the Two Dimensional Palatini Action

abstract:
  The symplectic analysis, initiated by Faddeev and Jackiw, is applied to the
first order (Palatini) form of the Einstein-Hilbert action in 1 + 1 dimensions.
The constraints that arise are shown to result in the same gauge
transformations that follow from the first class constraints occurring when the
Dirac constraint formalism is applied to this action. Problems associated with
gauge fixing are discussed.


title: A hypothesis for the color bimodality of Jupiter Trojans

abstract:
  One of the most enigmatic and hitherto unexplained properties of Jupiter
Trojans is their bimodal color distribution. This bimodality is indicative of
two sub-populations within the Trojans, which have distinct size distributions.
In this paper, we present a simple, plausible hypothesis for the origin and
evolution of the two Trojan color sub-populations. In the framework of
dynamical instability models of early Solar System evolution, which suggest a
common primordial progenitor population for both Trojans and Kuiper belt
objects, we use observational constraints to assert that the color bimodalities
evident in both minor body populations developed within the primordial
population prior to the onset of instability. We show that, beginning with an
initial composition of rock and ices, location-dependent volatile loss through
sublimation in this primordial population could have led to sharp changes in
the surface composition with heliocentric distance. We propose that the
depletion or retention of H$_{2}$S ice on the surface of these objects was the
key factor in creating an initial color bimodality. Objects that retained
H$_{2}$S on their surfaces developed characteristically redder colors upon
irradiation than those that did not. After the bodies from the primordial
population were scattered and emplaced into their current positions, they
preserved this primordial color bimodality to the present day. We explore
predictions of the volatile loss model - in particular, the effect of
collisions within the Trojan population on the size distributions of the two
sub-populations - and propose further experimental and observational tests of
our hypothesis


title: Rank three geometry and positive curvature

abstract:
  An axiomatic characterization of buildings of type $\CC_3$ due to Tits is
used to prove that any cohomogeneity two polar action of type $\CC_3$ on a
positively curved simply connected manifold is equivariantly diffeomorphic to a
polar action on a rank one symmetric space. This includes two actions on the
Cayley plane whose associated $\CC_3$ type geometry is not covered by a
building.


title: Stringy Chern classes of singular toric varieties and their applications

abstract:
  Let X be a normal projective Q-Gorenstein variety with at worst log-terminal
singularities. We prove a formula expressing the total stringy Chern class of a
generic complete intersection in X via the total stringy Chern class of X. This
formula is motivated by its applications to mirror symmetry for Calabi-Yau
complete intersections in toric varieties. We compute stringy Chern classes and
give a combinatorial interpretation of the stringy Libgober-Wood identity for
arbitrary projective Q-Gorenstein toric varieties. As an application we derive
a new combinatorial identity relating d-dimensional reflexive polytopes to the
number 12 in dimension d>3.


title:
Secular bipolar growth rate of the real US GDP per capita: implications
  for understanding past and future economic growth

abstract:
  We present a quantitative characterisation of the fluctuations of the
annualized growth rate of the real US GDP per capita growth at many scales,
using a wavelet transform analysis of two data sets, quarterly data from 1947
to 2015 and annual data from 1800 to 2010. Our main finding is that the
distribution of GDP growth rates can be well approximated by a bimodal function
associated to a series of switches between regimes of strong growth rate
$\rho_\text{high}$ and regimes of low growth rate $\rho_\text{low}$. The
succession of such two regimes compounds to produce a remarkably stable long
term average real annualized growth rate of 1.6\% from 1800 to 2010 and
$\approx 2.0\%$ since 1950, which is the result of a subtle compensation
between the high and low growth regimes that alternate continuously. Thus, the
overall growth dynamics of the US economy is punctuated, with phases of strong
growth that are intrinsically unsustainable, followed by corrections or
consolidation until the next boom starts. We interpret these findings within
the theory of "social bubbles" and argue as a consequence that estimations of
the cost of the 2008 crisis may be misleading. We also interpret the absence of
strong recovery since 2008 as a protracted low growth regime $\rho_\text{low}$
associated with the exceptional nature of the preceding large growth regime.


title: Balanced Locally Repairable Codes

abstract:
  We introduce a family of balanced locally repairable codes (BLRCs) $[n, k,
d]$ for arbitrary values of $n$, $k$ and $d$. Similar to other locally
repairable codes (LRCs), the presented codes are suitable for applications that
require a low repair locality. The novelty that we introduce in our
construction is that we relax the strict requirement the repair locality to be
a fixed small number $l$, and we allow the repair locality to be either $l$ or
$l+1$. This gives us the flexibility to construct BLRCs for arbitrary values of
$n$ and $k$ which partially solves the open problem of finding a general
construction of LRCs. Additionally, the relaxed locality criteria gives us an
opportunity to search for BLRCs that have a low repair locality even when
double failures occur. We use metrics such as a storage overhead, an average
repair bandwidth, a Mean Time To Data Loss (MTTDL) and an update complexity to
compare the performance of BLRCs with existing LRCs.


title:
Towards Persistent Storage and Retrieval of Domain Models using Graph
  Database Technology

abstract:
  We employ graph database technology to persistently store and retrieve robot
domain models.


title:
Unseeded Large Scale PIV measurements accounting for capillary-gravity
  waves phase speed

abstract:
  Large Scale Particle Image Velocimetry (LSPIV) is widely recognized as a
reliable method to measure water surface velocity field in open channels and
rivers. LSPIV technique is based on a camera view that frames the water surface
in a sequence, and image-processing methods to compute water surface
displacements between consecutive frames. Using LSPIV, high flow velocities, as
for example flood conditions, were accurately measured, whereas determinations
of low flow velocities is more challenging, especially in absence of floating
seeding transported by the flow velocity. In fact, in unseeded conditions,
typical surface features dynamics must be taken into account: besides surface
structures convected by the current, capillary-gravity waves travel in all
directions, with their own dynamics. Discrimination between all these phenomena
is here discussed, providing a new method to distinguish and to correct
unseeded LSPIV measurements associated with wavy structures, accounting for
their phase speed magnitude and direction. This has been done measuring
wavenumber vectors by using the same images exploited for PIV analysis. All
measurements are performed without any flow seeding and in total absence of
suspended materials, using the specular reflection of the water surface as a
key marker. Results obtained at low-flow regimes in a straight concrete-made
rectangular-section channel and in a river are satisfying, especially if
compared to those obtained from classic LSPIV application without
discrimination and correction. Moreover, a novel simple and safe procedure to
orthorectify images is here presented.


title: Multi-Skyrmions with orientational moduli

abstract:
  We analyze the mechanism of condensation of orientational moduli (as
introduced in [25]) on multi-Skyrmionic configurations of the four-dimensional
Skyrme model. The present analysis reveals interesting novel features. First of
all, the orientational moduli tend to decrease the repulsive interactions
between Skyrmions, the effect decreasing with the increase of the Baryon
number. Moreover, in the case of a single Skyrmion, the appearance of moduli is
energetically favorable if finite volume effects are present. Otherwise, in the
usual flat topologically trivial case, it is not. In the low energy theory
these solutions can be interpreted as Skyrmions with additional isospin degrees
of freedom.


title:
A new model test in high energy physics in frequentist and Bayesian
  statistical formalisms

abstract:
  A problem of a new physical model test given observed experimental data is a
typical one for modern experiments of high energy physics (HEP). A solution of
the problem may be provided with two alternative statistical formalisms, namely
frequentist and Bayesian, which are widely spread in contemporary HEP searches.
A characteristic experimental situation is modeled from general considerations
and both the approaches are utilized in order to test a new model. The results
are juxtaposed, what demonstrates their consistency in this work. An effect of
a systematic uncertainty treatment in the statistical analysis is also
considered.


title: Localization in an acoustic cavitation cloud

abstract:
  Using a nonlinear sound wave equation for a bubbly liquid in conjunction with
an equation for bubble pulsation, we predict and experimentally demonstrate the
appearance of a gap in the frequency spectrum of a sound wave propagating in a
cavitation cloud comprising bubbles. For bubbles with an ambient radius of 100
{\mu}m, the calculations revealed that this gap corresponds to the phenomenon
of sound wave localization. For bubbles with an ambient radius of 120 {\mu}m,
this spectral gap relates to a forbidden band of the sound wave. In the
experiment, we observed the predicted gap in the frequency spectrum in soda
water; however, in tap water, no spectral gap was present because the bubbles
were much smaller than 100 {\mu}m.


title: Sampling Rate Distortion

abstract:
  Consider a discrete memoryless multiple source with $m$ components of which
$k \leq m$ possibly different sources are sampled at each time instant and
jointly compressed in order to reconstruct all the $m$ sources under a given
distortion criterion. A new notion of sampling rate distortion function is
introduced, and is characterized first for the case of fixed-set sampling.
Next, for independent random sampling performed without knowledge of the source
outputs, it is shown that the sampling rate distortion function is the same
regardless of whether or not the decoder is informed of the sequence of sampled
sets. Furthermore, memoryless random sampling is considered with the sampler
depending on the source outputs and with an informed decoder. It is shown that
deterministic sampling, characterized by a conditional point-mass, is optimal
and suffices to achieve the sampling rate distortion function. For memoryless
random sampling with an uninformed decoder, an upper bound for the sampling
rate distortion function is seen to possess a similar property of conditional
point-mass optimality. It is shown by example that memoryless sampling with an
informed decoder can outperform strictly any independent random sampler, and
that memoryless sampling can do strictly better with an informed decoder than
without.


title:
Multiparameter Fuss--Catalan numbers with application to algebraic
  equations

abstract:
  We present an exposition on the Fuss--Catalan numbers, which are a
generalization of the well known Catalan numbers. The literature on the subject
is scattered (especially for the case of multiple independent parameters, as
will be explained in the text), with overlapping definitions by different
authors and duplication of proofs. This paper collects the main theorems and
identities, with a consistent notation. Contact is made with the works of
numerous authors, including the early works of Lambert and Euler. We
demonstrate the application of the formalism to solve algebraic equations by
infinite series. Our main result in this context is a new necessary and
sufficient formula for the domain of absolute convergence of the series
solutions of algebraic equations, which corrects and extends previous work in
the field. Some historical material is placed in an Appendix.


title: Test vectors for local periods

abstract:
  Let $E/F$ be a quadratic extension of non-archimedean local fields of
characteristic zero. An irreducible admissible representation $\pi$ of
$GL(n,E)$ is said to be distinguished with respect to $GL(n,F)$ if it admits a
non-trivial linear form that is invariant under the action of $GL(n,F)$. It is
known that there is exactly one such invariant linear form up to multiplication
by scalars, and an explicit linear form is given by integrating Whittaker
functions over the $F$-points of the mirabolic subgroup when $\pi$ is unitary
and generic. In this paper, we prove that the essential vector of [JPSS81] is a
test vector for this standard distinguishing linear form and that the value of
this form at the essential vector is a local $L$-value. As an application we
determine the value of a certain proportionality constant between two explicit
distinguishing linear forms. We then extend all our results to the non-unitary
generic case.


title: Molecular Mechanics of Chitin-Protein Interface

abstract:
  Chitin and protein are two main building blocks for many natural
biomaterials. The interaction between chitin and protein critically determines
the properties of the composite biological materials. As living organisms
usually encounter complex ambient conditions like water, pH and ions are
critical factors towards the structural integrity of biomaterials. It is
therefore essential to study the chitin-protein interface under different
environmental conditions. Here, an atomistic model consisting of a chitin
substrate and a protein filament is constructed, which is regarded as a
representative of the chitin-protein interface existing in many chitin-based
biomaterials. Based on this model, the mechanical properties of chitin-protein
interface under different moisture and pH values are investigated through
molecular dynamics simulations. The results reveal a weakening effect of water
towards the chitin-protein interface, as well as acidity, i.e. the protonated
protein forms a stronger adhesion to chitin than that in the alkaline
environment. In addition, the effect from side-chain of protein is studied and
it is found that certain kinds of amino acid can form hydrophobic connections
to chitin surface, which means that these peptides partly dodge the weakening
effect of water. Our observation indicates that terminuses and side-chains in
protein are of importance in forming interfacial hydrogen bonds. From our full
atomistic models, we can observe some molecular mechanisms about how protein
interacts with chitin in different conditions, which may spotlight the
engineering on biomaterials with similar interfaces.


title:
Multi-modal dictionary learning for image separation with application in
  art investigation

abstract:
  In support of art investigation, we propose a new source separation method
that unmixes a single X-ray scan acquired from double-sided paintings. In this
problem, the X-ray signals to be separated have similar morphological
characteristics, which brings previous source separation methods to their
limits. Our solution is to use photographs taken from the front and back-side
of the panel to drive the separation process. The crux of our approach relies
on the coupling of the two imaging modalities (photographs and X-rays) using a
novel coupled dictionary learning framework able to capture both common and
disparate features across the modalities using parsimonious representations;
the common component models features shared by the multi-modal images, whereas
the innovation component captures modality-specific information. As such, our
model enables the formulation of appropriately regularized convex optimization
procedures that lead to the accurate separation of the X-rays. Our dictionary
learning framework can be tailored both to a single- and a multi-scale
framework, with the latter leading to a significant performance improvement.
Moreover, to improve further on the visual quality of the separated images, we
propose to train coupled dictionaries that ignore certain parts of the painting
corresponding to craquelure. Experimentation on synthetic and real data - taken
from digital acquisition of the Ghent Altarpiece (1432) - confirms the
superiority of our method against the state-of-the-art morphological component
analysis technique that uses either fixed or trained dictionaries to perform
image separation.


title: Novel quantum initial conditions for inflation

abstract:
  We present a novel approach for setting initial conditions on the mode
functions of the Mukhanov Sazaki equation. These conditions are motivated by
minimisation of the renormalised stress-energy tensor, and are valid for
setting a vacuum state even in a context where the spacetime is changing
rapidly. Moreover, these alternative conditions are potentially observationally
distinguishable. We apply this to the kinetically dominated universe, and
compare with the more traditional approach.


title: Best-Response Dynamics in Combinatorial Auctions with Item Bidding

abstract:
  In a combinatorial auction with item bidding, agents participate in multiple
single-item second-price auctions at once. As some items might be substitutes,
agents need to strategize in order to maximize their utilities. A number of
results indicate that high welfare can be achieved this way, giving bounds on
the welfare at equilibrium. Recently, however, criticism has been raised that
equilibria are hard to compute and therefore unlikely to be attained.
  In this paper, we take a different perspective. We study simple best-response
dynamics. That is, agents are activated one after the other and each activated
agent updates his strategy myopically to a best response against the other
agents' current strategies. Often these dynamics may take exponentially long
before they converge or they may not converge at all. However, as we show,
convergence is not even necessary for good welfare guarantees. Given that
agents' bid updates are aggressive enough but not too aggressive, the game will
remain in states of good welfare after each agent has updated his bid at least
once.
  In more detail, we show that if agents have fractionally subadditive
valuations, natural dynamics reach and remain in a state that provides a $1/3$
approximation to the optimal welfare after each agent has updated his bid at
least once. For subadditive valuations, we can guarantee an $\Omega(1/\log m)$
approximation in case of $m$ items that applies after each agent has updated
his bid at least once and at any point after that. The latter bound is
complemented by a negative result, showing that no kind of best-response
dynamics can guarantee more than an $o(\log \log m/\log m)$ fraction of the
optimal social welfare.


title: Josephson currents induced by the Witten effect

abstract:
  We reveal the existence of a new type of topological Josephson effect
involving type II superconductors and three-dimensional topological insulators
as tunnel junctions. We predict that vortex lines induce a variant of the
Witten effect that is the consequence of the axion electromagnetic response of
the topological insulator: at the interface of the junction each flux quantum
attains a fractional electrical charge of e/4. As a consequence, if an external
magnetic field is applied perpendicular to the junction, the Witten effect
induces an AC Josephson effect in absence of any external voltage. We derive a
number of further experimental consequences and propose potential setups where
these {quantized, flux induced, Witten} effects may be observed.


title:
Generation of narrow-band polarization-entangled photon pairs at a
  rubidium D1 line

abstract:
  Using the process of cavity-enhanced spontaneous parametric down-conversion
(SPDC), we generate a narrow-band polarization-entangled photon pair resonant
on the rubidium (Rb) D1 line (795 nm). The degenerate single-mode photon pair
is selected by multiple temperature controlled etalons. The linewidth of
generated polarization-entangled photon pairs is 15 MHz which matches the
typical atomic memory bandwidth. The measured Bell parameter for the
polarization-entangled photons S=2.73+-0.04 which violates the Bell-CHSH
inequality by ~18 standard deviations. The presented entangled photon pair
source could be utilized in quantum communication and quantum computing based
on quantum memories in atomic ensemble.


title:
Protein single-model quality assessment by feature-based probability
  density functions

abstract:
  Protein quality assessment (QA) has played an important role in protein
structure prediction. We developed a novel single-model quality assessment
method - Qprob. Qprob calculates the absolute error for each protein feature
value against the true quality scores (i.e. GDT-TS scores) of protein
structural models, and uses them to estimate its probability density
distribution for quality assessment. Qprob has been blindly tested on the 11th
Critical Assessment of Techniques for Protein Structure Prediction (CASP11) as
MULTICOM-NOVEL server. The official CASP result shows that Qprob ranks as one
of the top single-model QA methods. In addition, Qprob makes contributions to
our protein tertiary structure predictor MULTICOM, which is officially ranked
3rd out of 143 predictors. The good performance shows that Qprob is good at
assessing the quality of models of hard targets. These results demonstrate that
this new probability density distribution based method is effective for protein
single-model quality assessment and is useful for protein structure prediction.
The webserver and software packages of Qprob are available at:
http://calla.rnet.missouri.edu/qprob/.


title:
On the Optimal Management of Public Debt: a Singular Stochastic Control
  Problem

abstract:
  Consider the problem of a government that wants to reduce the debt-to-GDP
(gross domestic product) ratio of a country. The government aims at choosing a
debt reduction policy which minimises the total expected cost of having debt,
plus the total expected cost of interventions on the debt ratio. We model this
problem as a singular stochastic control problem over an infinite time-horizon.
In a general not necessarily Markovian framework, we first show by
probabilistic arguments that the optimal debt reduction policy can be expressed
in terms of the optimal stopping rule of an auxiliary optimal stopping problem.
We then exploit such link to characterise the optimal control in a
two-dimensional Markovian setting in which the state variables are the level of
the debt-to-GDP ratio and the current inflation rate of the country. The latter
follows uncontrolled Ornstein-Uhlenbeck dynamics and affects the growth rate of
the debt ratio. We show that it is optimal for the government to adopt a policy
that keeps the debt-to-GDP ratio under an inflation-dependent ceiling. This
curve is given in terms of the solution of a nonlinear integral equation
arising in the study of a fully two-dimensional optimal stopping problem.


title: Using quantum friction to synchronize rotating bodies

abstract:
  Proposing a combined system of a nanoparticle and a plane surface in the
presence of electromagnetic vacuum fluctuations, the electromagnetic and medium
fields have been quantized. Quantum friction of nanoparticle due to the
presence of plane surface and also electromagnetic vacuum has been discussed.
The possibility of synchronizing rotating bodies through the quantum friction
between them are investigated. It has been shown that there is a significant
connection between the synchronization of the rotating bodies and their quantum
friction.


title:
Fashion, fads and the popularity of choices: micro-foundations for
  diffusion consumer theory

abstract:
  Knowledge acquisition by consumers is a key process in the diffusion of
innovations. However, in standard theories of the representative agent, agents
do not learn and innovations are adopted instantaneously. Here, we show that in
a discrete choice model where utility-maximising agents with heterogenous
preferences learn about products through peers, their stock of knowledge on
products becomes heterogenous, fads and fashions arise, and transitivity in
aggregate preferences is lost. Non-equilibrium path-dependent dynamics emerge,
the representative agent exhibits behavioural rules different than individual
agents, and aggregate utility cannot be optimised. Instead, an evolutionary
theory of product innovation and diffusion emerges.


title: Canonicity for Cubical Type Theory

abstract:
  Cubical type theory is an extension of Martin-L\"of type theory recently
proposed by Cohen, Coquand, M\"ortberg and the author which allows for direct
manipulation of $n$-dimensional cubes and where Voevodsky's Univalence Axiom is
provable. In this paper we prove canonicity for cubical type theory: any
natural number in a context build from only name variables is judgmentally
equal to a numeral. To achieve this we formulate a typed and deterministic
operational semantics and employ a computability argument adapted to a
presheaf-like setting.


title: The 2008 election: A preregistered replication analysis

abstract:
  We present an increasingly stringent set of replications of Ghitza & Gelman
(2013), a multilevel regression and poststratification analysis of polls from
the 2008 U.S. presidential election campaign, focusing on a set of plots
showing the estimated Republican vote share for whites and for all voters, as a
function of income level in each of the states.
  We start with a nearly-exact duplication that uses the posted code and
changes only the model-fitting algorithm; we then replicate using
already-analyzed data from 2004; and finally we set up preregistered
replications using two surveys from 2008 that we had not previously looked at.
We have already learned from our preliminary, non-preregistered replication,
which has revealed a potential problem with the published analysis of Ghitza &
Gelman (2013); it appears that our model may not sufficiently account for
nonsampling error, and that some of the patterns presented in that earlier
paper may simply reflect noise.
  In addition to the substantive interest in validating earlier findings about
demographics, geography, and voting, the present project serves as a
demonstration of preregistration in a setting where the subject matter is
historical (and thus the replication data exist before the preregistration plan
is written) and where the analysis is exploratory (and thus a replication
cannot be simply deemed successful or unsuccessful based on the statistical
significance of some particular comparison).