title: Heading for the Clouds: Implications for Cloud Computing Adopters

abstract:
  Cloud computing projects have many implications, including issues such as
security, compliance, funding, cohesion with existing systems, operational
resource requirements, and number of employees involved. In order to gain a
better understanding of why businesses are interested in adopting cloud
services in spite of these potential difficulties, we interviewed senior IT
personnel at five different organizations about their processes related to
cloud decisions, their thoughts before and during the process, and the outcome
of their endeavor. Our results provide insights from their perspectives into
the similarities and differences among the organizations and the implications
of going into the cloud. We conclude with a list of recommended questions and
areas to consider for use by other organizations looking into adopting cloud
services. The ultimate goal is to help businesses considering a cloud computing
project by providing advice from other organizations based on their experience.


title:
Inose's construction and elliptic K3 surfaces with Mordell-Weil rank 15
  revisited

abstract:
  We describe two constructions of elliptic K3 surfaces starting from the
Kummer surface of the Jacobian of a genus 2 curve. These parallel the
base-change constructions of Kuwata for the Kummer surface of a product of two
elliptic curves. One of these also involves the analogue of an Inose fibration.
We use these methods to provide explicit examples of elliptic K3 surfaces over
the rationals of geometric Mordell-Weil rank 15.


title:
Energy Efficient Resource Allocation for Time-Varying OFDMA Relay
  Systems with Hybrid Energy Supplies

abstract:
  This paper investigates the energy efficient resource allocation for
orthogonal frequency division multiple access (OFDMA) relay systems, where the
system is supplied by the conventional utility grid and a renewable energy
generator equipped with a storage device. The optimal usage of radio resource
depends on the characteristics of the renewable energy generation and the
mobile traffic, which exhibit both temporal and spatial diversities. Lyapunov
optimization method is used to decompose the problem into the joint flow
control, radio resource allocation and energy management without knowing a
priori knowledge of system statistics. It is proven that the proposed algorithm
can result in close-to-optimal performance with capacity limited data buffer
and storage device. Simulation results show that the flexible tradeoff between
the system utility and the conventional energy consumption can be achieved.
Compared with other schemes, the proposed algorithm demonstrates better
performance.


title: Characterizations of the Connected Forcing Number of a Graph

abstract:
  Zero forcing is a dynamic graph coloring process whereby a colored vertex
with a single uncolored neighbor forces that neighbor to be colored. This
forcing process has been used to approximate certain linear algebraic
parameters, as well as to model the spread of diseases and information in
social networks. In this paper, we introduce and study the connected forcing
process -- a restriction of zero forcing in which the initially colored set of
vertices induces a connected subgraph. We show that the connected forcing
number -- the cardinality of the smallest initially colored vertex set which
forces the entire graph to be colored -- is a sharp upper bound to the maximum
nullity, path cover number, and leaf number of the graph. We also give closed
formulas and bounds for the connected forcing numbers of several families of
graphs including trees, hypercubes, and flower snarks, and characterize graphs
with extremal connected forcing numbers.


title:
A Novel Compressive Sensing based Enhanced Multiplexing Scheme for MIMO
  System

abstract:
  A novel compressive-sensing based signal multiplexing scheme is proposed in
this paper to further improve the multiplexing gain for multiple input multiple
output (MIMO) system. At the transmitter side, a Gaussian random measurement
matrix in compressive sensing is employed before the traditional spatial
multiplexing in order to carry more data streams on the available spatial
multiplexing streams of the underlying MIMO system. At the receiver side, it is
proposed to reformulate the detection of the multiplexing signal into two
steps. In the first step, the traditional MIMO equalization can be used to
restore the transmitted spatial multiplexing signal of the MIMO system. While
in the second step, the standard optimization based detection algorithm assumed
in the compressive sensing framework is utilized to restore the CS multiplexing
data streams, wherein the exhaustive over-complete dictionary is used to
guarantee the sparse representation of the CS multiplexing signal. In order to
avoid the excessive complexity, the sub-block based dictionary and the
sub-block based CS restoration is proposed. Finally, simulation results are
presented to show the feasibility of the proposed CS based enhanced MIMO
multiplexing scheme. And our efforts in this paper shed some lights on the
great potential in further improving the spatial multiplexing gain for the MIMO
system.


title:
An Information Theoretic Study for Noisy Compressed Sensing With Joint
  Sparsity Model-2

abstract:
  In this paper, we study a support set reconstruction problem in which the
signals of interest are jointly sparse with a common support set, and sampled
by joint sparsity model-2 (JSM-2) in the presence of noise. Using mathematical
tools, we develop upper and lower bounds on the failure probability of support
set reconstruction in terms of the sparsity, the ambient dimension, the minimum
signal to noise ratio, the number of measurement vectors and the number of
measurements. These bounds can be used to provide a guideline to determine the
system parameters in various applications of compressed sensing with noisy
JSM-2. Based on the bounds, we develop necessary and sufficient conditions for
reliable support set reconstruction. We interpret these conditions to give
theoretical explanations about the benefits enabled by joint sparsity structure
in noisy JSM-2. We compare our sufficient condition with the existing result of
noisy multiple measurement vectors model (MMV). As a result, we show that noisy
JSM-2 may require less number of measurements than noisy MMV for reliable
support set reconstruction.


title:
Calculation of Spin Observables for Proton-Neutron Elastic Scattering in
  the Bethe-Salpeter Equation

abstract:
  Bethe-Salpeter equation is applied to $p$-$n$ elastic scattering. The spin
observables are calculated by the M matrix similar to $p$-$p$ case. The
parameters of the meson-exchange model are used with the cut-off for the pion
exchange interaction. Change of the M matrix indicates breaking of the charge
independence in the nucleon-nucleon system.


title:
Gamma rays from muons from WIMPs: Implementation of radiative muon
  decays for dark matter analyses

abstract:
  Dark matter searches in gamma ray final states often make use of the fact
that photons can be produced from final state muons. Modern Monte Carlo
generators and DM codes include the effects of final state radiation from muons
produced in the dark matter annihilation process itself, but neglect the O(1%)
radiative correction that arises from the subsequent muon decay. After
implementing this correction we demonstrate the effect that it can have on dark
matter phenomenology by considering the case of dark matter annihilation to
four muons via scalar mediator production. We first show that the AMS-02
positron excess can no longer easily be made consistent with this final state
once the Fermi-LAT dwarf limits are calculated with the inclusion of radiative
muon decays, and we next show that the Fermi-LAT galactic centre gamma excess
can be improved with this final state after inclusion of the same effect. We
provide code and tables for the implementation of this effect in the popular
dark matter code micrOMEGAs, providing a solution for any model producing final
state muons.


title:
Classification of globally F-regular $F$-sandwiches of Hirzebruch
  surfaces

abstract:
  Let $X$ be a smooth variety over an algebraically closed field of positive
characteristic. An $F$-sandwich of $X$ is a normal variety $Y$ through which
the relative Frobenius morphism of $X$ factors as $F:X\rightarrow Y \rightarrow
X$. In this paper, we give a classification of globally F-regular
$F$-sandwiches of Hirzebruch surfaces.


title: Globally F-regular $F$-sandwiches of degree $p$ of a projective space

abstract:
  We prove that globally F-regular $F$-sandwiches of degree $p$ of a projective
space are toric varieties.


title:
A dichotomy law for the Diophantine properties in $\beta$-dynamical
  systems

abstract:
  Let $\beta>1$ be a real number and define the $\beta$-transformation on
$[0,1]$ by $T_\beta:x\mapsto \beta x\bmod 1$. Further, define
$$W_y(T_{\beta},\Psi):=\{x\in [0, 1]:|T_\beta^nx-y|<\Psi(n) \mbox{ for
infinitely many $n$}\}$$ and $$W(T_{\beta},\Psi):=\{(x, y)\in [0,
1]^2:|T_\beta^nx-y|<\Psi(n) \mbox{ for infinitely many $n$}\},$$ where
$\Psi:\mathbb{N}\to\mathbb{R}_{>0}$ is a positive function such that
$\Psi(n)\to 0$ as $n\to \infty$. In this paper, we show that each of the above
sets obeys a Jarn\'ik-type dichotomy, that is, the generalised Hausdorff
measure is either zero or full depending upon the convergence or divergence of
a certain series. This work completes the metrical theory of these sets.


title: Infrared [Fe II] Emission Lines from Radiative Atomic Shocks

abstract:
  [Fe II] emission lines are prominent in the infrared (IR), and they are
important diagnostic tools for radiative atomic shocks. We investigate the
emission characteristics of [Fe II] lines using a shock code developed by
Raymond (1979) with updated atomic parameters. We first review general
characteristics of IR [Fe II] emission lines from shocked gas, and derive [Fe
II] line fluxes as a function of shock speed and ambient density. We have
compiled the available IR [Fe II] line observations of interstellar shocks and
compare them to the ratios predicted from our model. The sample includes both
young and old supernova remnants in the Galaxy and the Large Magellanic Cloud
and several Herbig-Haro objects. We find that the observed ratios of IR [Fe II]
lines generally fall on our grid of shock models, but the ratios of some
mid-infrared lines, e.g., [Fe II] 35.35 um/[Fe II] 25.99 um, [Fe II] 5.340
um/[Fe II] 25.99 um, and [Fe II] 5.340 um/[Fe II] 17.94 um, are significantly
offset from our model grid. We discuss possible explanations and conclude that
the uncertainty in atomic rates might be the major source of uncertainty, while
uncertainties in the shock modeling and the observations certainly exist.


title: Topological Entropy of Random Walks on Mapping Class Groups

abstract:
  For any pseudo-Anosov diffeomorphism on a closed orientable surface $S$ of
genus greater than one, it is known by the work of Bers and Thurston that the
topological entropy agrees with the translation distance on the Teichm\"uller
space with respect to the Teichm\"uller metric. In this paper, we consider
random walks on the mapping class group of $S$. The drift of a random walk is
defined as the translation distance of the random walk. We define the
topological entropy of a random walk and prove that it almost surely agrees
with the drift on the Teichm\"uller space with respect to the Teichm\"uller
metric.


title: Diagram uniqueness for highly twisted knots

abstract:
  Frequently, knots are enumerated by their crossing number. However, the
number of knots with crossing number $c$ grows exponentially with $c$, and to
date computer-assisted proofs can only classify diagrams up to around twenty
crossings. Instead, we consider diagrams enumerated by bridge number, following
the lead of Schubert who classified 2-bridge knots in the 1950s. We prove a
uniqueness result for this enumeration. Using recent developments in geometric
topology, including distances in the curve complex and techniques with
incompressible surfaces, we show that infinitely many knot and link diagrams
have a unique simple $m$-bridge diagram. Precisely, if $m$ is at least three,
if each twist region of the diagram has at least three crossings, and if the
length $n$ of the diagram is sufficiently long, i.e., $n>4m(m-2)$, then such a
diagram is unique up to obvious rotations. This projection gives a canonical
form for such knots and links, and thus provides a classification of these
knots or links.


title:
Universal scaling for the spin-electricity conversion on surface states
  of topological insulators

abstract:
  We have investigated spin-electricity conversion on surface states of
bulk-insulating topological insulator (TI) materials using a spin pumping
technique. The sample structure is Ni-Fe|Cu|TI trilayers, in which magnetic
proximity effects on the TI surfaces are negligibly small owing to the inserted
Cu layer. Voltage signals produced by the spin-electricity conversion are
clearly observed, and enhanced with decreasing temperature in line with the
dominated surface transport at lower temperatures. The efficiency of the
spin-electricity conversion is greater for TI samples with higher resistivity
of bulk states and longer mean free path of surface states, consistent with the
surface spin-electricity conversion.


title: Stability of Secant Bundles on Second Symmetric Power of Curves

abstract:
  Given a rank $r$ stable bundle over a smooth irreducible projective curve
$C,$ there is an associated rank $2r$ bundle over $S^2(C),$ the second
symmetric power of $C.$ In this article we study the stability of this bundle.
As a consequence we get an immersion from the moduli space of stable bundles
over $C$ to the associated moduli space of stable bundles over $S^2(C).$


title: The Fourier series of the log-Barnes function

abstract:
  In this paper we determine the Fourier series expansion of the log-Barnes
function. This is the analogue of the classical result of Kummer and Malmsten.
  Applying this expansion we get some integrals similar to the Espinosa-Moll
log-Gamma integrals with respect to $\log G$. During the course of the paper
some interesting log-Gamma integrals and a log-harmonic sum are evaluated.


title:
Constructing the ordinary character tables of some Atlas groups using
  character theoretic methods

abstract:
  We compute the character tables of the following groups with character
theoretic methods, using known information about the conjugacy classes and
about the character tables of some subgroups and factor groups: $Th$, $J_4$,
$2.{}^2E_6(2)$, $2.{}^2E_6(2).2$, and $2.B$.


title: Equivalence of Quantum Metrics with a common domain

abstract:
  We characterize Lipschitz morphisms between quantum compact metric spaces as
those *-morphisms which preserve the domain of certain noncommutative analogues
of Lipschitz seminorms, namely lower semi-continuous Lip-norms. As a corollary,
lower semi-continuous Lip-norms with a shared domain are in fact equivalent. We
then note that when a family of lower semi-continuous Lip-norms are uniformly
equivalent, then they give rise to totally bounded classes of quantum compact
metric spaces, and we apply this observation to several examples of
perturbations of quantum metric spaces. We also construct the noncommutative
generalization of the Lipschitz distance between quantum compact metric spaces.


title: Higher Spin Currents in the N=2 Stringy Coset Minimal Model

abstract:
  In the coset model based on (A_{N-1}^{(1)} \oplus A_{N-1}^{(1)},
A_{N-1}^{(1)}) at level (N, N; 2N), it is known that the N=2 superconformal
algebra can be realized by the two kinds of adjoint fermions. Each Kac-Moody
current of spin-1 is given by the product of fermions with structure constant
(f symbols) as usual. One can construct the spin-1 current by combining the
above two fermions with the structure constant and the spin-1 current by
multiplying these two fermions with completely symmetric SU(N) invariant tensor
of rank 3 (d symbols). The lowest higher spin-2 current with nonzero U(1)
charge (corresponding to the zeromode eigenvalue of spin-1 current of N=2
superconformal algebra) can be obtained from these four spin-1 currents in
quadratic form. Similarly, the other type of lowest higher spin-2 current,
whose U(1) charge is opposite to the above one, can be obtained also. Four
higher spin-5/2 currents can be constructed from the operator product
expansions (OPEs) between the spin-3/2 currents of N=2 superconformal algebra
and the above two higher spin-2 currents. The two higher spin-3 currents can be
determined by the OPEs between the above spin-3/2 currents and the higher
spin-5/2 currents. Finally, the ten N=2 OPEs between the four N=2 higher spin
multiplets (2, 5/2, 5/2, 3), (2, 5/2, 5/2, 3), (7/2, 4, 4, 9/2) and (7/2, 4, 4,
9/2) are obtained explicitly for generic N.


title:
Controlled processing of signal stored in metamaterial with tripod
  structure

abstract:
  In the present paper we have discussed in detail electromagnetically induced
transparency and signal storing in the case of one signal pulses propagating in
a classical electric medium resembling this of four-level atoms in the tripod
configuration. Our theoretical results confirm recently observed dependence of
transparency windows position on coupling parameters. In the process of storing
the pulse energy is confined inside the metamaterial as electric charge
oscillations and after required time it is possible to switch the control
fields on again and to release the trapped signal. By manipulating the driving
fields one can thus control the parameters of the released signal and even to
divide it on demand into arbitrary parts.


title: Detection of timescales in evolving complex systems

abstract:
  Most complex systems are intrinsically dynamic in nature. The evolution of a
dynamic complex system is typically represented as a sequence of snapshots,
where each snapshot describes the configuration of the system at a particular
instant of time. Then, one may directly follow how the snapshots evolve in
time, or aggregate the snapshots within some time intervals to form
representative "slices" of the evolution of the system configuration. This is
often done with constant intervals, whose duration is based on arguments on the
nature of the system and of its dynamics. A more refined approach would be to
consider the rate of activity in the system to perform a separation of
timescales. However, an even better alternative would be to define dynamic
intervals that match the evolution of the system's configuration. To this end,
we propose a method that aims at detecting evolutionary changes in the
configuration of a complex system, and generates intervals accordingly. We show
that evolutionary timescales can be identified by looking for peaks in the
similarity between the sets of events on consecutive time intervals of data.
Tests on simple toy models reveal that the technique is able to detect
evolutionary timescales of time-varying data both when the evolution is smooth
as well as when it changes sharply. This is further corroborated by analyses of
several real datasets. Our method is scalable to extremely large datasets and
is computationally efficient. This allows a quick, parameter-free detection of
multiple timescales in the evolution of a complex system.


title:
Self-consistent continuum random-phase approximation with finite-range
  interactions for charge-exchange excitations

abstract:
  The formalism of the continuum random-phase approximation theory which
treats, without ap- proximations, the continuum part of the single-particle
spectrum, is extended to describe charge- exchange excitations. Our approach is
self-consistent, meaning that we use a unique, finite-range, interaction in the
Hartree-Fock calculations which generate the single-particle basis and in the
con- tinuum random-phase approximation which describes the excitation. We study
excitations induced by the Fermi, Gamow-Teller and spin-dipole operators in
doubly magic nuclei by using four Gogny- like finite-range interactions, two of
them containing tensor forces. We focus our attention on the importance of the
correct treatment of the continuum configuration space and on the effects of
the tensor terms of the force.1


title: Coherent-state-induced transparency

abstract:
  We examine electromagnetically induced transparency (EIT) in an ensemble of
cold $\Lambda-$type atoms induced by a quantum control field in multi-mode
coherent states and compare it with the transparency created by the classical
light of the same intensity. We show that the perfect coincidence is achieved
only in the case of a single-mode coherent state, whereas the transparency
sharply decreases, when the number of the modes exceeds the mean number of
control photons in the medium. The origin of the effect is the modification of
photon statistics in the control field with increasing the number of the modes
that weakens its interaction with atoms resulting in a strong probe absorption.
For the same reason, the probe pulse transforms from EIT-based slow-light into
superluminal propagation caused by the absorption.


title: Probabilistic bounds on the trapping redundancy of linear codes

abstract:
  The trapping redundancy of a linear code is the number of rows of a smallest
parity-check matrix such that no submatrix forms an $(a,b)$-trapping set. This
concept was first introduced in the context of low-density parity-check (LDPC)
codes in an attempt to estimate the number of redundant rows in a parity-check
matrix suitable for iterative decoding. Essentially the same concepts appear in
other contexts as well such as robust syndrome extraction for quantum error
correction. Among the known upper bounds on the trapping redundancy, the
strongest one was proposed by employing a powerful tool in probabilistic
combinatorics, called the Lov\'{a}sz Local Lemma. Unfortunately, the proposed
proof invoked this tool in a situation where an assumption made in the lemma
does not necessarily hold. Hence, although we do not doubt that nonetheless the
proposed bound actually holds, for it to be a mathematical theorem, a more
rigorous proof is desired. Another disadvantage of the proposed bound is that
it is only applicable to $(a,b)$-trapping sets with rather small $a$. Here, we
give a more general and sharper upper bound on trapping redundancy by making
mathematically more rigorous use of probabilistic combinatorics without relying
on the lemma. Our bound is applicable to all potentially avoidable
$(a,b)$-trapping sets with $a$ smaller than the minimum distance of a given
linear code, while being generally much sharper than the bound through the
Lov\'{a}sz Local Lemma. In fact, our upper bound is sharp enough to exactly
determine the trapping redundancy for many cases, thereby providing precise
knowledge in the form of a more general bound with mathematical rigor.


title:
Statistical properties of fluctuations of time series representing the
  appearance of words in nationwide blog data and their applications: An
  example of observations and the modelling of fluctuation scalings of
  nonstationary time series

abstract:
  To elucidate the non-trivial empirical statistical properties of fluctuations
of a typical non-steady time series representing the appearance of words in
blogs, we investigated approximately five billion Japanese blogs over a period
of six years and analyse some corresponding mathematical models. First, we
introduce a solvable non-steady extension of the random diffusion model, which
can be deduced by modelling the behaviour of heterogeneous random bloggers.
Next, we deduce theoretical expressions for both the temporal and ensemble
fluctuation scalings of this model, and demonstrate that these expressions can
reproduce all empirical scalings over eight orders of magnitude. Furthermore,
we show that the model can reproduce other statistical properties of time
series representing the appearance of words in blogs, such as functional forms
of the probability density and correlations in the total number of blogs. As an
application, we quantify the abnormality of special nationwide events by
measuring the fluctuation scalings of 1771 basic adjectives.


title: Pivot duality of universal interpolation and extrapolation spaces

abstract:
  It is a widely used method, for instance in perturbation theory, to associate
with a given C0-semigroup its so-called interpolation and extrapolation spaces.
In the model case of the shift semigroup acting on L^2(R), the resulting chain
of spaces recovers the classical Sobolev scale. In 2014, the second named
author defined the universal interpolation space as the projective limit of the
interpolation spaces and the universal extrapolation space as the completion of
the inductive limit of the extrapolation spaces, provided that the latter is
Hausdorff.
  In this note we use the notion of the dual with respect to a pivot space in
order to show that the aforementioned inductive limit is Hausdorff, already
complete, and can be represented as the dual of the projective limit whenever a
power of the generator of the initial semigroup is a self-adjoint operator. In
the case of the classical Sobolev scale we show that the duality holds, and
that the two universal spaces were already studied by Laurent Schwartz in the
1950s.
  Our results and examples complement the approach of Haase, who in 2006 gave a
different definition of universal extrapolation spaces in the context of
functional calculi. Haase avoids the inductive limit topology precisely for the
reason that it a priori cannot be guaranteed that the latter is always
Hausdorff. We show that this is indeed the case provided that we start with a
semigroup defined on a reflexive Banach space.


title:
Evaluation of the use of web technology by government of Sri Lanka to
  ensure food security for its citizens

abstract:
  Web technology is one of the key areas in information and communication
technology to be used as a powerful tool in ensuring food security which is one
of the main issues in Sri Lanka. Web technology involves in communicating and
sharing resources in network of computers all over the world. Main focus of
food security is to ensure that all people have fair access to sufficient and
quality food without endangering the future supply of the same food. In this
context, web sites play a vital and major role in achieving food security in
Sri Lanka. In this case study, websites pertaining to Sri Lankan government and
link with food security were analyzed to find out their impact in achieving the
goals of food security using web technologies and how they are being involved
in ensuring food security in Sri Lanka. The other objective of this study is to
make the Sri Lankan government aware of present situation of those websites in
addressing food security related issues and how modern web technologies could
be effectively and efficiently used to address those issues. So, the relevant
websites were checked against several criteria and scores were used to assess
their capabilities to address the concerns of food security. It was found that
the amount of emphasis given by these websites to address the issues of food
security is not satisfactory. Further, it showed that if these web sites could
be improved further, they would generate a powerful impact on ensuring food
security in Sri Lanka.


title: A note on badly approximabe sets in projective space

abstract:
  Recently, Ghosh \& Haynes \cite{HG} proved a Khintchine-type result for the
problem of Diophantine approximation in certain projective spaces. In this note
we complement their result by observing that a Jarn\'{\i}k-type result also
holds for `badly approximable' points in real projective space. In particular,
we prove that the natural analogue in projective space of the classical set of
badly approximable numbers has full Hausdorff dimension when intersected with
certain compact subsets of real projective space. Furthermore, we also
establish an analogue of Khintchine's theorem for convergence relating to
`intrinsic' approximation of points in these compact sets.


title: A note on the bi-periodic Fibonacci and Lucas matrix sequences

abstract:
  In this paper, we introduce the bi-periodic Lucas matrix sequence and present
some fundamental properties of this generalized matrix sequence. Moreover, we
investigate the important relationships between the bi-periodic Fibonacci and
Lucas matrix sequences. We express that some behaviours of bi-periodic Lucas
numbers also can be obtained by considering properties of this new matrix
sequence. Finally, we say that the matrix sequences as Lucas, $k$-Lucas and
Pell-Lucas are special cases of this generalized matrix sequence.


title: Isotope effect on gyro-fluid edge turbulence and zonal flows

abstract:
  The role of ion polarisation and finite Larmor radius on the isotope effect
on turbulent tokamak edge transport and flows is investigated by means of local
electromagnetic multi-species gyro-fluid computations. Transport is found to be
reduced with the effective plasma mass for protium, deuterium and tritium
mixtures. This isotope effect is found for both cold and warm ion models, but
significant influence of finite Larmor radius and polarisation effects are
identified. Sheared flow reduction of transport through self generated
turbulent zonal flows and geodesic acoustic modes in the present model (not
including neoclassical flows) is found to play only a minor role on regulating
isotopically improved confinement.


title:
Anderson Localization in high temperature QCD: background configuration
  properties and Dirac eigenmodes

abstract:
  We investigate the properties of the background gauge field configurations
that act as disorder for the Anderson localization mechanism in the Dirac
spectrum of QCD at high temperatures. We compute the eigenmodes of the M\"obius
domain-wall fermion operator on configurations generated for the $SU(3)$ gauge
theory with two flavors of fermions, in the temperature range $[0.9,1.9]T_c$.
We identify the source of localization of the eigenmodes with gauge
configurations that are self-dual and support negative fluctuations of the
Polyakov loop $P_L$, in the high temperature sea of $P_L\sim 1$. The dependence
of these observations on the boundary conditions of the valence operator is
studied. We also investigate the spatial overlap of the left-handed and
right-handed projected eigenmodes in correlation with the localization and the
corresponding eigenvalue. We discuss an interpretation of the results in terms
of monopole-instanton structures.

categories: hep-lat cond-mat.dis-nn cond-mat.stat-mech hep-ph hep-th


title:
Entrainment, motion and deposition of coarse particles transported by
  water over a sloping mobile bed

abstract:
  In gravel-bed rivers, bedload transport exhibits considerable variability in
time and space. Recently, stochastic bedload transport theories have been
developed to address the mechanisms and effects of bedload transport
fluctuations. Stochastic models involve parameters such as particle
diffusivity, entrainment and deposition rates. The lack of hard information on
how these parameters vary with flow conditions is a clear impediment to their
application to real-world scenarios. In this paper, we determined the closure
equations for the above parameters from laboratory experiments. We focused on
shallow supercritical flow on a sloping mobile bed in straight channels, a
setting that was representative of flow conditions in mountain rivers.
Experiments were run at low sediment transport rates under steady nonuniform
flow conditions (i.e., the water discharge was kept constant, but bedforms
developed and migrated upstream, making flow nonuniform). Using image
processing, we reconstructed particle paths to deduce the particle velocity and
its probability distribution, particle diffusivity, and rates of deposition and
entrainment. We found that on average, particle acceleration, velocity and
deposition rate were responsive to local flow conditions, whereas entrainment
rate depended strongly on local bed activity. Particle diffusivity varied
linearly with the depth-averaged flow velocity. The empirical probability
distribution of particle velocity was well approximated by a Gaussian
distribution when all particle positions were considered together. In contrast,
the particles located in close vicinity to the bed had exponentially
distributed velocities. Our experimental results provide closure equations for
stochastic or deterministic bedload transport models.


title:
Hindered magnetic dipole transitions between P-wave bottomonia and
  coupled-channel effects

abstract:
  In the hindered magnetic dipole transitions of heavy quarkonia, the
coupled-channel effects originating from the coupling of quarkonia to a pair of
heavy and anti-heavy mesons can play a dominant role. Here, we study the
hindered magnetic dipole transitions between two $P$-wave bottomonia, $\chi_b(n
P)$ and $h_b(n^\prime P)$, with $n\neq n^\prime$. In these processes the
coupled-channel effects are expected to lead to partial widths much larger than
the quark model predictions. We estimate these partial widths which, however,
are very sensitive to unknown coupling constants related to the vertices
$\chi_{b0}(nP)B\bar B$. A measurement of the hindered M1 transitions can shed
light on the coupled-channel dynamics in these transitions and hence on the
size of the coupling constants. We also suggest to check the coupled-channel
effects by comparing results from quenched and fully dynamical lattice QCD
calculations.


title:
Weak Error for the Euler Scheme Approximation of Diffusions with
  Non-Smooth Coefficients *

abstract:
  We study the weak error associated with the Euler scheme of non degenerate
diffusion processes with non smooth bounded coefficients. Namely, we consider
the cases of H{\"o}lder continuous coefficients as well as piecewise smooth
drifts with smooth diffusion matrices.


title: The CMA Evolution Strategy: A Tutorial

abstract:
  This tutorial introduces the CMA Evolution Strategy (ES), where CMA stands
for Covariance Matrix Adaptation. The CMA-ES is a stochastic, or randomized,
method for real-parameter (continuous domain) optimization of non-linear,
non-convex functions. We try to motivate and derive the algorithm from
intuitive concepts and from requirements of non-linear, non-convex search in
continuous domain.


title:
Rotational Surfaces in Isotropic Spaces Satisfiying Weingarten
  Conditions

abstract:
  In this paper, we study the rotational surfaces in the isotropic 3-space I^3.
satisfying Weingarten conditions in terms of the relative curvature K (analogue
of the Gaussian curvature) and the isotropic mean curvature H. In particular,
we classify such surfaces of linear Weingarten type in I^3.


title: On Maximal Regularity for a Class of Evolutionary Equations

abstract:
  The issue of so-called maximal regularity is discussed within a Hilbert space
framework for a class of evolutionary equations. Viewing evolutionary equations
as a sums of two unbounded operators, showing maximal regularity amounts to
establishing that the operator sum considered with its natural domain is
already closed. For this we use structural constraints of the coefficients
rather than semi-group strategies or sesqui-linear form methods, which would be
difficult to come by for our general problem class. Our approach, although
limited to the Hilbert space case, complements known strategies for approaching
maximal regularity and extends them in a different direction. The abstract
findings are illustrated by re-considering some known maximal regularity
results within the framework presented.


title:
Simultaneous Measurement of Two Quantum Observables: Compatibility,
  Broadcasting, and In-between

abstract:
  One of the central features of quantum theory is that there are pairs of
quantum observables that cannot be measured simultaneously. This
incompatibility of quantum observables is a necessary ingredient in several
quantum phenomena, such as measurement uncertainty relations, violation of Bell
inequalities and steering. Two quantum observables that admit a simultaneous
measurement are, in this respect, classical. A finer classification of
classicality can be made by formulating four symmetric relations on the set of
observables that are stronger than compatibility; they are broadcastability,
one-side broadcastability, mutual nondisturbance and nondisturbance. It is
proven that the five relations form a hierarchy, and their differences in terms
of the required devices needed in a simultaneous measurement is explained. All
the four relations stronger than compatibility are completely characterized in
the case of qubit observables.


title:
Polaronic effects of an impurity in a Fermi superfluid away from the BEC
  limit

abstract:
  In this article we study the interaction between an impurity and the gas of
Bogoliubov excitations of a Fermi superfluid by mapping it on the polaron
problem for an impurity in a BEC. The description of the Fermi superfluid
across the BEC-BCS crossover regime is based on a recently developed effective
field theory presented in [Eur. Phys. J. B 88, 122 (2015)] and provides us with
the interaction-dependent dispersion relations for the Bogoliubov excitations.
The behavior of the polaronic coupling constant $\alpha$ and of the effective
mass of the polaron is examined in a broad window of the BEC-BCS crossover.


title: Categories: How I Learned to Stop Worrying and Love Two Sorts

abstract:
  RS-frames were introduced by Gehrke as relational semantics for substructural
logics. They are two-sorted structures, based on RS-polarities with additional
relations used to interpret modalities. We propose an intuitive, epistemic
interpretation of RS-frames for modal logic, in terms of categorization systems
and agents' subjective interpretations of these systems. Categorization systems
are a key to any decision-making process and are widely studied in the social
and management sciences.
  A set of objects together with a set of properties and an incidence relation
connecting objects with their properties forms a polarity which can be `pruned'
into an RS-polarity. Potential categories emerge as the Galois-stable sets of
this polarity, just like the concepts of Formal Concept Analysis. An agent's
beliefs about objects and their properties (which might be partial) is modelled
by a relation which gives rise to a normal modal operator expressing the
agent's beliefs about category membership. Fixed-points of the iterations of
the belief modalities of all agents are used to model categories constructed
through social interaction.


title: On the distribution of stellar-sized black hole spins

abstract:
  Black hole spin will have a large impact on searches for gravitational waves
with advanced detectors. While only a few stellar mass black hole spins have
been measured using X-ray techniques, gravitational wave detectors have the
capacity to greatly increase the statistics of black hole spin measurements. We
show what we might learn from these measurements and how the black hole spin
values are influenced by their formation channels.


title: Distances in scale free networks at criticality

abstract:
  Scale-free networks with moderate edge dependence experience a phase
transition between ultrasmall and small world behaviour when the power law
exponent passes the critical value of three. Moreover, there are laws of large
numbers for the graph distance of two randomly chosen vertices in the giant
component. When the degree distribution follows a pure power law these show the
same asymptotic distances of $\frac{\log N}{\log\log N}$ at the critical value
three, but in the ultrasmall regime reveal a difference of a factor two between
the most-studied rank-one and preferential attachment model classes. In this
paper we identify the critical window where this factor emerges. We look at
models from both classes when the asymptotic proportion of vertices with degree
at least~$k$ scales like $k^{-2} (\log k)^{2\alpha + o(1)}$ and show that for
preferential attachment networks the typical distance is
$\big(\frac{1}{1+\alpha}+o(1)\big)\frac{\log N}{\log\log N}$ in probability as
the number~$N$ of vertices goes to infinity. By contrast the typical distance
in a rank one model with the same asymptotic degree sequence is
$\big(\frac{1}{1+2\alpha}+o(1)\big)\frac{\log N}{\log\log N}.$ As
$\alpha\to\infty$ we see the emergence of a factor two between the length of
shortest paths as we approach the ultrasmall regime.


title: Quantum state transfer by time reversal in the continuum

abstract:
  A method for high-fidelity quantum state transfer in a quantum network
coupled to a continuum, based on time reversal in the continuum after decay, is
theoretically suggested. Provided that the energy spectrum of the network is
symmetric around a reference energy and symmetric energy states are coupled the
same way to the common continuum, ideal perfect state transfer can be obtained
after time reversal. In particular, it is shown that in a linear tight-binding
chain a quantum state can be transformed into its mirror image with respect to
the center of the chain after a controllable time. As compared to quantum
mirror image based on coherent transport in a static chain with properly
tailored inhomogeneous hopping rates, our method does not require hopping rate
engineering and is less sensitive to disorder for long transfer times.


title:
Ionization in Orthogonal Two-Color Laser Fields - Origin and Phase
  Dependence of Trajectory-Resolved Coulomb Effects

abstract:
  We report on electron momentum distributions from single ionization of Ar in
strong orthogonally polarized two-color (OTC) laser fields measured with the
COLTRIMS technique. We study the effect of Coulomb focusing whose signature is
a cusp like feature in the center of the electron momentum spectrum. While the
direct electrons show the expected strong dependence on the phase between the
two colors, surprisingly the Coulomb focused structure is almost not influenced
by the weak second harmonic streaking field. This effect is explained by the
use of a CTMC simulation which describes the tunneled electron wave packet in
terms of classical trajectories under the influence of the combined Coulomb-
and OTC laser field. We find a subtle interplay between the initial momentum of
the electron upon tunneling, the ionization phase and the action of the Coulomb
field that makes the Coulomb focused part of the momentum spectrum apparently
insensitive to the weaker streaking field.


title:
Simulations of inspiraling and merging double neutron stars using the
  Spectral Einstein Code

abstract:
  We present results on the inspiral, merger, and post-merger evolution of a
neutron star - neutron star (NSNS) system. Our results are obtained using the
hybrid pseudospectral-finite volume Spectral Einstein Code (SpEC). To test our
numerical methods, we evolve an equal-mass system for $\approx 22$ orbits
before merger. This waveform is the longest waveform obtained from fully
general-relativistic simulations for NSNSs to date. Such long (and accurate)
numerical waveforms are required to further improve semi-analytical models used
in gravitational wave data analysis, for example the effective one body models.
We discuss in detail the improvements to SpEC's ability to simulate NSNS
mergers, in particular mesh refined grids to better resolve the merger and
post-merger phases. We provide a set of consistency checks and compare our
results to NSNS merger simulations with the independent BAM code. We find
agreement between them, which increases confidence in results obtained with
either code. This work paves the way for future studies using long waveforms
and more complex microphysical descriptions of neutron star matter in SpEC.


title: Topic Model Based Multi-Label Classification from the Crowd

abstract:
  Multi-label classification is a common supervised machine learning problem
where each instance is associated with multiple classes. The key challenge in
this problem is learning the correlations between the classes. An additional
challenge arises when the labels of the training instances are provided by
noisy, heterogeneous crowdworkers with unknown qualities. We first assume
labels from a perfect source and propose a novel topic model where the present
as well as the absent classes generate the latent topics and hence the words.
We non-trivially extend our topic model to the scenario where the labels are
provided by noisy crowdworkers. Extensive experimentation on real world
datasets reveals the superior performance of the proposed model. The proposed
model learns the qualities of the annotators as well, even with minimal
training data.


title: Heat Kernel estimates for general boundary problems

abstract:
  We show that not feeling the boundary estimates for heat kernels hold for any
non-negative self-adjoint extension of the Laplace operator acting on
vector-valued compactly supported functions on a domain in $\mathbb{R}^d$. They
are therefore valid for any choice of boundary condition and we show that the
implied constants can be chosen independent of the self-adjoint extension. The
method of proof is very general and is based on finite propagation speed
estimates and explicit Fourier Tauberian theorems obtained by Y. Safarov.


title:
Fluidisation and plastic activity in a model soft-glassy material
  flowing in micro-channels with rough walls

abstract:
  By means of mesoscopic numerical simulations of a model soft-glassy material,
we investigate the role of boundary roughness on the flow behaviour of the
material, probing the bulk/wall and global/local rheologies. We show that the
roughness reduces the wall slip induced by wettability properties and acts as a
source of fluidisation for the material. A direct inspection of the plastic
events suggests that their rate of occurrence grows with the fluidity field,
reconciling our simulations with kinetic elasto-plastic descriptions of jammed
materials. Notwithstanding, we observe qualitative and quantitative differences
in the scaling, depending on the distance from the rough wall and on the
imposed shear. The impact of roughness on the orientational statistics is also
studied.


title:
A Survey of Energy-Efficient Techniques for 5G Networks and Challenges
  Ahead

abstract:
  After about a decade of intense research, spurred by both economic and
operational considerations, and by environmental concerns, energy efficiency
has now become a key pillar in the design of communication networks. With the
advent of the fifth generation of wireless networks, with millions more base
stations and billions of connected devices, the need for energy-efficient
system design and operation will be even more compelling. This survey provides
an overview of energy-efficient wireless communications, reviews seminal and
recent contribution to the state-of-the-art, including the papers published in
this special issue, and discusses the most relevant research challenges to be
addressed in the future.


title: Relay Selection for Cooperative NOMA

abstract:
  This letter studies the impact of relay selection (RS) on the performance of
cooperative non-orthogonal multiple access (NOMA). In particular, a two-stage
RS strategy is proposed, and analytical results are developed to demonstrate
that this two-stage strategy can achieve the minimal outage probability among
all possible RS schemes, and realize the maximal diversity gain. The provided
simulation results show that cooperative NOMA with this two-stage RS scheme
outperforms that with the conventional max-min approach, and can also yield a
significant performance gain over orthogonal multiple access.


title:
Achieving Open Vocabulary Neural Machine Translation with Hybrid
  Word-Character Models

abstract:
  Nearly all previous work on neural machine translation (NMT) has used quite
restricted vocabularies, perhaps with a subsequent method to patch in unknown
words. This paper presents a novel word-character solution to achieving open
vocabulary NMT. We build hybrid systems that translate mostly at the word level
and consult the character components for rare words. Our character-level
recurrent neural networks compute source word representations and recover
unknown target words when needed. The twofold advantage of such a hybrid
approach is that it is much faster and easier to train than character-based
ones; at the same time, it never produces unknown words as in the case of
word-based models. On the WMT'15 English to Czech translation task, this hybrid
approach offers an addition boost of +2.1-11.4 BLEU points over models that
already handle unknown words. Our best system achieves a new state-of-the-art
result with 20.7 BLEU score. We demonstrate that our character models can
successfully learn to not only generate well-formed words for Czech, a
highly-inflected language with a very complex vocabulary, but also build
correct representations for English source words.


title:
Evaluation of the forward Compton scattering off protons: II.
  Spin-dependent amplitude and observables

abstract:
  The forward Compton scattering off the proton is determined by substituting
the empirical total photoabsorption cross sections into dispersive sum rules.
In addition to the spin-independent amplitude evaluated previously [Phys. Rev.
D 92, 074031 (2015)], we obtain the spin-dependent amplitude over a broad
energy range. The two amplitudes contain all the information about this
process, and we, hence, can reconstruct the nonvanishing observables of the
proton Compton scattering in the forward kinematics. The results are compared
with predictions of chiral perturbation theory where available. The low-energy
expansion of the spin-dependent Compton scattering amplitude yields the
Gerasimov-Drell-Hearn (GDH) sum rule and relations for the forward spin
polarizabilities (FSPs) of the proton. Our evaluation provides an empirical
verification of the GDH sum rule for the proton, and yields empirical values of
the proton FSPs. For the GDH integral, we obtain $204.5(21.4)$ $\mu$b, in
agreement with the sum rule prediction: $204.784481(4)$ $\mu$b. For the FSPs,
we obtain: $\gamma_0=-92.9(10.5) \times 10^{-6}$ fm$^4$, and
$\bar{\gamma_0}=48.4(8.2) \times 10^{-6}$ fm$^6$, improving on the accuracy of
previous evaluations.


title: Image Captioning with Deep Bidirectional LSTMs

abstract:
  This work presents an end-to-end trainable deep bidirectional LSTM
(Long-Short Term Memory) model for image captioning. Our model builds on a deep
convolutional neural network (CNN) and two separate LSTM networks. It is
capable of learning long term visual-language interactions by making use of
history and future context information at high level semantic space. Two novel
deep bidirectional variant models, in which we increase the depth of
nonlinearity transition in different way, are proposed to learn hierarchical
visual-language embeddings. Data augmentation techniques such as multi-crop,
multi-scale and vertical mirror are proposed to prevent overfitting in training
deep models. We visualize the evolution of bidirectional LSTM internal states
over time and qualitatively analyze how our models "translate" image to
sentence. Our proposed models are evaluated on caption generation and
image-sentence retrieval tasks with three benchmark datasets: Flickr8K,
Flickr30K and MSCOCO datasets. We demonstrate that bidirectional LSTM models
achieve highly competitive performance to the state-of-the-art results on
caption generation even without integrating additional mechanism (e.g. object
detection, attention model etc.) and significantly outperform recent methods on
retrieval task.


title:
Spontaneous concentrations of solids through two-way drag forces between
  gas and sedimenting particles

abstract:
  The behaviour of sedimenting particles depends on the dust-to-gas ratio of
the fluid. Linear stability analysis shows that solids settling in the Epstein
drag regime would remain homogeneously distributed in non-rotating
incompressible fluids, even when dust-to-gas ratios reach unity. However, the
non-linear evolution has not been probed before. Here, we present numerical
calculations indicating that in a particle-dense mixture solids spontaneously
mix out of the fluid and form swarms overdense in particles by at least a
factor 10. The instability is caused by mass-loaded regions locally breaking
the equilibrium background stratification. The driving mechanism depends on
non-linear perturbations of the background flow and shares some similarity to
the streaming instability in accretion discs. The resulting particle-rich
swarms may stimulate particle growth by coagulation. In the context of
protoplanetary discs, the instability could be relevant for aiding small
particles to settle to the midplane in the outer disc. Inside the gas envelopes
of protoplanets, enhanced settling may lead to a reduced dust opacity, which
facilitates the contraction of the envelope. We show that the relevant physical
set up can be recreated in a laboratory setting. This will allow our numerical
calculations to be investigated experimentally in the future.


title:
A CRIRES-search for H3+ emission from the hot Jupiter atmosphere of HD
  209458 b

abstract:
  Close-in extrasolar giant planets are expected to cool their thermospheres by
producing H3+ emission in the near-infrared (NIR), but simulations predict H3+
emission intensities that differ in the resulting intensity by several orders
of magnitude. We want to test the observability of H3+ emission with CRIRES at
the Very Large Telescope (VLT), providing adequate spectral resolution for
planetary atmospheric lines in NIR spectra. We search for signatures of
planetary H3+ emission in the L` band, using spectra of HD 209458 obtained
during and after secondary eclipse of its transiting planet HD 209458 b. We
searched for H3+ emission signatures in spectra containing the combined light
of the star and, possibly, the planet. With the information on the ephemeris of
the transiting planet, we derive the radial velocities at the time of
observation and search for the emission at the expected line positions and
search for planetary signals and use a shift and add technique combining all
observed spectra taken after sec. eclipse to calculate an upper emission limit.
We do not find signatures of atmospheric H3+ emission in the spectra containing
the combined light of HD 209458 and planet b. We calculate the emission limit
for the H3+ line at 3953.0 nm (Q(1, 0)) to be 8.32 E18W and a limit of 5.34E18
W for the line at 3985.5 nm (Q(3, 0)). Comparing our emission limits to the
theoretical predictions suggests that we lack 1 to 3 magnitudes of sensitivity
to measure H3+ emission in our target object. We show that under more favorable
weather conditions the data quality can be improved significantly, reaching 5
E16W for star-planet systems that are close to Earth. We estimate that pushing
the detection limit down to 1E15W will be possible with ground-based
observations with future instrumentation, for example, the E-ELT.


title: Mild solutions of semilinear elliptic equations in Hilbert spaces

abstract:
  This paper extends the theory of regular solutions ($C^1$ in a suitable
sense) for a class of semilinear elliptic equations in Hilbert spaces. The
notion of regularity is based on the concept of $G$-derivative, which is
introduced and discussed. A result of existence and uniqueness of solutions is
stated and proved under the assumption that the transition semigroup associated
to the linear part of the equation has a smoothing property, that is, it maps
continuous functions into $G$-differentiable ones. The validity of this
smoothing assumption is fully discussed for the case of the Ornstein-Uhlenbeck
transition semigroup and for the case of invertible diffusion coefficient
covering cases not previously addressed by the literature. It is shown that the
results apply to Hamilton-Jacobi-Bellman (HJB) equations associated to infinite
horizon optimal stochastic control problems in infinite dimension and that, in
particular, they cover examples of optimal boundary control of the heat
equation that were not treatable with the approaches developed in the
literature up to now.


title: Asymptotic Analysis of Self-Adjusting Contraction Trees

abstract:
  In this paper, we present asymptotic analysis of self-adjusting contraction
trees for incremental sliding window analytics.


title: M\'ethodes Matricielles Introduction \`a la Complexit\'e Alg\'ebrique

abstract:
  The main purpose of this book is to propose an introduction to the modern
tools of algebraic complexity. To remain as simple as possible while providing
meaningful examples, we chose to focus on effective linear algebra; this is
certainly one of the best possible choices to give an idea of the main problems
in algebraic complexity. The contents of the book are the following: classical
results of linear algebra and basic algorithms in linear algebra, straight-line
programs as a model of computation, with an emphasis on Strassen's method known
as "elimination of divisions", a discussion on various notions of complexity, a
presentation of the general algorithmic strategy "divide and conquer", a first
important example: the fast multiplication of polynomials, the very heart of
the book: the fast multiplication of matrices, with a discussion of derived
fast algorithms for various problems of linear algebra. The particular case of
the computation of the determinant is then discussed, and the last chapter
deals with the difficult computation of the permanent (Valiant's conjecture).
This book gives an introduction to a fascinating subject at a reasonable level.
. . for French-speaking people.


title:
Discovery of periodic and alternating flares of the methanol and water
  masers in G107.298+5.639

abstract:
  Methanol and water vapour masers are signposts of early stages of high-mass
star formation but it is generally thought that due to different excitation
processes they probe distinct parts of stellar environments. Here we present
observations of the intermediate-mass young stellar object G107.298+5.639,
revealing for the first time that 34.4 d flares of the 6.7 GHz methanol maser
emission alternate with flares of individual features of the 22 GHz water
maser. High angular resolution data reveal that a few components of both maser
species showing periodic behaviour coincide in position and velocity and all
the periodic water maser components appear in the methanol maser region of size
of 360 au. The maser flares could be caused by variations in the infrared
radiation field induced by cyclic accretion instabilities in a circumstellar or
protobinary disc. The observations do not support either the stellar pulsations
or the seed photon flux variations as the underlying mechanisms of the
periodicity in the source.


title: The t-structure induced by an n-tilting module

abstract:
  We study the t-structure induced by an n-tilting module T in the derived
category D(R) of a ring R. Our main objective is to determine when the heart of
the t-structure is a Grothendieck category. We obtain characterizations in
terms of properties of the module category over the endomorphism ring of T and
as a main result we prove that the heart is a Grothendieck category if and only
if T is a pure projective $R$-module.


title: Driving-induced stability with long-range effects

abstract:
  We give a sufficient condition under which an applied rotation on medium
particles stabilizes a slow probe in the rotation center. The symmetric part of
the stiffness matrix thus gets a positive Lamb shift with respect to
equilibrium. For illustration we take diffusive medium particles with a
self-potential in the shape of a Mexican hat, high around the origin. There is
a short-range attraction between the medium particles and the heavier probe,
all immersed in an equilibrium thermal bath. For no or small rotation force on
the medium particles, the origin is an unstable fixed point for the probe and
the precise shape of the self-potential at large distances from the origin is
irrelevant for the statistical force there. Above a certain rotation threshold,
while the medium particles are still repelled from the origin, the probe
stabilizes there and more details of the medium-density at large distance start
to matter. The effect is robust around the quasi-static limit with rotation
threshold only weakly depending on the temperature but the stabilization gets
stronger at lower temperatures.


title:
Extending DLR with Labelled Tuples, Projections, Functional Dependencies
  and Objectification (full version)

abstract:
  We introduce an extension of the n-ary description logic DLR to deal with
attribute-labelled tuples (generalising the positional notation), with
arbitrary projections of relations (inclusion dependencies), generic functional
dependencies and with global and local objectification (reifying relations or
their projections). We show how a simple syntactic condition on the appearance
of projections and functional dependencies in a knowledge base makes the
language decidable without increasing the computational complexity of the basic
DLR language.


title:
A Tiny Eruptive Filament as a Flux-Rope Progenitor and Driver of a
  Large-Scale CME and Wave

abstract:
  A solar eruptive event SOL2010-06-13 observed with SDO/AIA has been discussed
in the contexts of the CME gebesis and an associated EUV transient in terms of
a shock driven by the apparent CME rim. We have revealed in this event an
erupting flux rope, studied its properties, and detected wave signatures inside
the developing CME. These findings have allowed us to establish new features in
the genesis of the CME and associated EUV wave and to reconcile all of the
episodes into a causally-related sequence. (1) A hot 11 MK flux rope developed
from a compact filament, accelerated up to 3 km/s$^2$ 1 min before a hard X-ray
burst and earlier than other structures, reached 420 km/s, and decelerated to
50 km/s. (2) The CME development was driven by the flux rope. Closed structures
above the rope got sequentially involved in the expansion from below upwards,
came closer together, and disappeared to reveal their envelope, the rim, which
became the outer boundary of the cavity. The rim was associated with the
separatrix surface of a magnetic domain, which contained the pre-eruptive
filament. (3) The rim formation was associated with a successive compression of
the upper active-region structures into the CME frontal structure (FS). When
the rim was formed, it resembled a piston. (4) The disturbance responsible for
the CME formation was excited by the flux rope inside the rim, and then
propagated outward. EUV structures at different heights started to accelerate,
when their trajectories in the distance-time diagram were crossed by the front
of this disturbance. (5) Outside the rim and FS, the disturbance propagated
like a blast wave, manifesting in a type II radio burst and a leading part of
the EUV transient. Its main, trailing part was the FS, which consisted of
swept-up 2 MK loops enveloping the rim. The wave decelerated and decayed soon,
being not driven by the trailing piston, which slowed down.


title:
Multiplicity results of fractional $p$-Laplace equations with
  sign-changing and singular nonlinearity

abstract:
  In this article, we study the following fractional $p$-Laplacian equation
with singular nonlinearity
  \begin{equation*}
  (P_{\la}) \left\{ \begin{array}{lr} - 2\int_{\mb
R^n}\frac{|w(y)-w(x)|^{p-2}(w(y)-w(x))}{|x-y|^{n+ps}}dy = a(x) w^{-q}+ \la b(x)
w^r\; \text{in}\; \Om \quad \quad w>0\;\text{in}\;\Om, \quad w = 0 \;
\mbox{in}\; \mb R^n \setminus\Om, \end{array} \quad \right. \end{equation*}
where $\Om$ is a bounded domain in $\mb R^n$ with smooth boundary $\partial
\Om$, $n> ps$,$s\in(0,1)$, $\la>0$, $0<q<1$, $q<p-1<r< p_{s}^*-1$ with
$p_{s}^*=\frac{np}{n-ps}$, $a: \Om\subset\mb R^n \ra \mb R$ such that $0<
a(x)\in L^{\frac{p^{*}_{s}}{p^{*}_{s}-1+q}}(\Om)$, and $b:\Om\subset\mb R^n \ra
\mb R$ is a sign-changing function such that $b(x)\in
L^{\frac{p^{*}_{s}}{p^{*}_{s}-1-r}}(\Om)$. Using variational methods, we show
existence and multiplicity of positive solutions of $(P_{\la})$ with respect to
the parameter $\la$.


title:
Solutions of Vectorial Hamilton-Jacobi Equations are Rank-One Absolute
  Minimisers in $L^\infty$

abstract:
  Given the supremal functional $E_\infty(u,\Omega')=ess\,\sup_{\Omega'}
H(\cdot,D u)$ defined on $W^{1,\infty}_{loc}(\Omega,\mathbb{R}^N)$, $\Omega'
\Subset \Omega\subseteq \mathbb{R}^n$, we identify a class of vectorial
rank-one Absolute Minimisers by proving a statement slightly stronger than the
next claim: vectorial solutions of the Hamilton-Jacobi equation $H(\cdot,D
u)=c$ are rank-one Absolute Minimisers if they are $C^1$. Our minimality notion
is a generalisation of the classical $L^\infty$ variational principle of
Aronsson to the vector case and emerged in earlier work of the author. The
assumptions are minimal, requiring only continuity and rank-one convexity of
the level sets.


title:
Combinatorics on several families of Kronecker coefficients related to
  plane partitions

abstract:
  We present a study of three families of Kronecker coefficients, which we
describe in terms of reduced Kronecker coefficients. This study is grounded on
the generating function of the coefficients, proved by a bijection between two
combinatorial objects. This study includes the connection between plane
partitions and these three families of reduced Kronecker coefficients,
providing us their combinatorial interpretation. As an application, we verify
that the saturation hypothesis holds for our three families of reduced
Kronecker coefficients. The study also includes other interpretation in terms
of the quasipolynomials that govern these families. We specify the degree and
the period of these quasipolynomials. Finally, the direct relation between
Kronecker coefficients and reduced Kronecker coefficients allows us to give
some observations about the rate of growth of the Kronecker coefficients
associated to the reduced Kronecker coefficients of the study.


title:
Global relaxation of bistable solutions for gradient systems in one
  unbounded spatial dimension

abstract:
  This paper is concerned with spatially extended gradient systems of the form
\[ u_t=-\nabla V (u) + \mathcal{D} u_{xx}\,, \] where spatial domain is the
whole real line, state-parameter $u$ is multidimensional, $\mathcal{D}$ denotes
a fixed diffusion matrix, and the potential $V$ is coercive at infinity.
"Bistable" solutions, that is solutions close at both ends of space to stable
homogeneous equilibria, are considered. For a solution of this kind, it is
proved that, if the homogeneous equilibria approached at both ends belong to
the same level set of the potential and if an appropriate (localized in space)
energy remains bounded from below when time increases, then the solution
approaches, when time approaches infinity, a pattern of stationary solutions
homoclinic or heteroclinic to homogeneous equilibria. This result provides a
step towards a complete description of the global behaviour of all bistable
solutions that is pursued in a companion paper. Some consequences are derived,
and applications to some examples are given.


title: Simulating the pitch sensitivity of twisted nematics of patchy rods

abstract:
  Stiff, elongated biomolecules such as filamentous viruses, DNA or cellulose
nanocrystals are known to form liquid crystals often exhibiting a helical
supramolecular organization. Little is known about the microscopic origin, size
and handedness of the helical pitch in these, so-called cholesteric phases.
Experimental observations in chiral lyotropics suggest that long-ranged chiral
forces of electrostatic origin acting between the mesogens are responsible for
such organization. Using large-scale computer simulation we study the
sensitivity of the pitch imparted by soft microscopic helices and confirm that
the helical sense is sensitive to a change of packing fraction, magnitude of
the molecular pitch and amplitude of the chiral interactions. In particular, we
find evidence that the cholesteric helix sense may change spontaneously upon
variation of particle density, at fixed molecular chirality. These pitch
inversions have been reported in recent theoretical studies but simulation
evidence remains elusive. We rationalize these sudden changes in the
supramolecular helical symmetry on the basis of detailed measurements of the
mean-torque generated by the twisting of the helices. The simulation
methodology employed does not require confining the twisted nematic in a slab
geometry and allows for a simultaneous measurement of the pitch and the twist
elastic constant. We find that the twist elastic constant increases almost
linearly with density suggesting that twisted nematic shows no signs of
anomalous stiffening due to pre-smectic fluctuations at higher packing
fraction.


title:
Dynamical polarizability, screening, and plasmons in one, two, and three
  dimensional massive Dirac systems

abstract:
  We study the density-density response function of a collection of charged
massive Dirac particles and present analytical expressions for the dynamical
polarization function in one, two and three dimensions. The polarization
function is then used to find the dispersion of the plasmon modes, and
electrostatic screening of Coulomb interactions within the random phase
approximation. We find that for massive Dirac systems, the oscillating screened
potential decays as $r^{-1}$, $r^{-2}$ and $r^{-3}$ in one, two, and three
dimensions respectively. However for massless Dirac systems there is no
electrostatic screening or Friedel oscillation in one dimension, and the
oscillating screened potential decays as $r^{-3}$ and $r^{-4}$, in two and
three dimensions respectively. Our analytical results for the polarization
function will be useful for exploring the physics of massive and massless Dirac
materials in different experimental systems with varying dimensionality.


title: Helicity of the toroidal vortex with swirl

abstract:
  On the basis of solutions of the Bragg-Hawthorne equations we discuss the
helicity of thin toroidal vortices with the swirl - the orbital motion along
the torus diretrix. It is shown that relationship of the helicity with
circulations along the small and large linked circles - directrix and
generatrix of the torus - depends on distribution of the azimuthal velocity in
the core of the swirling vortex ring. In the case of non-homogeneous swirl this
relationship differs from the well-known Moffat relationship - the doubled
product of such circulations multiplied by the number of links. The results can
be applied to vortices in planetary atmospheres and to vortex movements in the
vicinity of active galactic nuclei.


title:
Existence and multiplicity of solutions for a class of quasilinear
  problems in Orlicz-Sobolev spaces

abstract:
  This work is concerned with the existence and multiplicity of solutions for
the following class of quasilinear problems $$
-\Delta_{\Phi}u+\phi(|u|)u=f(u)~\text{in} ~\Omega_{\lambda}, u(x)>0
~\text{in}~\Omega_{\lambda}, u=0~ \mbox{on} ~\partial\Omega_{\lambda}, $$ where
$\Phi(t)=\int_0^{|t|} \phi(s) s \, ds $ is an $N-$function, $\Delta_{\Phi}$ is
the $\Phi-$Laplacian operator, \linebreak $\Omega_{\lambda}=\lambda \Omega,$
$\Omega$ is a smooth bounded domain in $\mathbb{R}^N,$ $N \geq 2$, $\lambda$ is
a positive parameter and $f: \mathbb{R}\rightarrow \mathbb{R}$ is a continuous
function. Here, we use variational methods to get multiplicity of solutions by
using of Lusternik-Schnirelmann category of ${\Omega}$ in itself.


title: Seeking for the observational manifestation of de Sitter Relativity

abstract:
  The de Sitter invariant special relativity is a natural extension of the
usual Einstein special relativity. Within this framework a generalization of
special relativity (SR) for the de Sitter space-time introduces a new length
scale $R$, serving an origin of geometrical cosmological constant
$\Lambda=3/R^2$. De Sitter relativity predicts the departure from the Lorentz
invariance due to spacetime curvature, related to the geometrical cosmological
constant. In this paper the possible impact of de Sitter special relativity
effects on threshold particle processes and equivalence principle violation is
considered. The main conclusion is that constraints, coming from cosmological
fine structure constant variations render this effects nowadays undetectable. A
brief outlook is given thereafter.


title:
Hidden global conformal symmetry without Virasoro extension in theory of
  elasticity

abstract:
  The theory of elasticity (a.k.a. Riva-Cardy model) has been regarded as an
example of scale invariant but not conformal field theories. We argue that in
$d=2$ dimensions, the theory has hidden global conformal symmetry of
$SL(2,\mathbb{R}) \times SL(2,\mathbb{R})$ without its Virasoro extension. More
precisely, we can embed all the correlation functions of the displacement
vector into a global conformal field theory with four-derivative action in
terms of two scalar potential variables, which necessarily violates the
reflection positivity. The energy-momentum tensor for the potential variables
cannot be improved to become traceless so that it does not show the Virasoro
symmetry even with the existence of global special conformal current.

categories: hep-th cond-mat.stat-mech math-ph math.MP


title: A Kronecker limit type formula for elliptic Eisenstein series

abstract:
  Let $\Gamma\subset\mathrm{PSL}_{2}(\mathbb{R})$ be a Fuchsian subgroup of the
first kind acting by fractional linear transformations on the upper half-plane
$\mathbb{H}$, and let $M=\Gamma\backslash\mathbb{H}$ be the associated finite
volume hyperbolic Riemann surface. Associated to any cusp of $M$, there is the
classically studied non-holomorphic (parabolic) Eisenstein series. In 1979,
Kudla and Millson studied non-holomorphic (hyperbolic) Eisenstein series
associated to any closed geodesic on $\Gamma\backslash\mathbb{H}$. In 2004,
Jorgenson and Kramer introduced so-called elliptic Eisenstein series associated
to any elliptic fixed point of $M$. In the present article, we prove the
meromorphic continuation of the elliptic Eisenstein series and we explicitly
compute its poles and residues. Further, we derive a Kronecker limit type
formula for elliptic Eisenstein series for general $\Gamma$. Finally, for the
full modular group $\mathrm{PSL}_{2}(\mathbb{Z})$, we give an explicit formula
for the Kronecker's limit functions in terms of holomorphic modular forms.


title:
Decarbonized Demand Response for Residential Plug-in Electric Vehicles
  in Smart Grids

abstract:
  Recently, in Paris, the world has reached an agreement whereby many countries
commit to bolster their efforts about reducing adverse climate changes. Hence,
we can expect that decarbonization will even attract more attention in
different energy sectors in near future. In particular, both generation side
and consumption side are required to be run more congruently and
environmentally friendly. Thus, employing the renewables at the generation side
along with our proposed decarbonized demand response (DDR) at the consumption
side could significantly reduce deleterious impacts on the climate. Such
ambition, at the consumption side, necessitates symbiosis and synergy between
the customers and the retailer, and among customers, respectively. In other
words, there should be some incentive-based collaboration between customers and
the retailer as well as coordination among customers to make the objective be
achieved successfully. In this paper, we present such matching demand response
(DR) algorithm for residential users owning vehicle-to-grid (V2G) enabled
plug-in electric vehicles (PEVs) who obtain electricity from a common retailer.
The retailer itself is connected to the wholesale electricity market to
purchase and sell electricity. Furthermore, we explain the details of the
existing symbiosis and synergy in our system. Our simulation results illustrate
that substantial cost savings can be achieved along with pollution reduction by
our proposed technique.


title:
Connecting probability distributions of different operators and
  generalization of the Chernoff-Hoeffding inequality

abstract:
  This work is devoted to explore fundamental aspects of the spectral
properties of few-body general operators. We first consider the following
question: when we know the probability distributions of a set of observables,
what can we way on the probability distribution of the summation of them? In
considering arbitrary operators, we could not obtain a useful information over
third order moment, while under the assumption of the few-body operators, we
can rigorously prove a much stronger bound on the moment generating function
for arbitrary quantum states. Second, by the use of this bound, we generalize
the Chernoff inequality (or the Hoeffding inequality), which characterizes the
asymptotic decay of the probability distribution for the product states by the
Gaussian decay. In the present form, the Chernoff inequality can be applied to
a summation of independent local observables (e.g., single-site operators). We
extend the range of application of the Chernoff inequality to the generic
few-body observables.

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


title:
Spin freezing in the disordered pyrochlore magnet NaCaCo$_2$F$_7$: NMR
  studies and Monte-Carlo simulations

abstract:
  We present results of $^{23}$Na and $^{19}$F nuclear magnetic resonance (NMR)
measurements on NaCaCo$_2$F$_7$, a frustrated pyrochlore magnet with a
Curie-Weiss temperature, $T_{cw}$ ~-140 K, and intrinsic bond disorder. Below
3.6 K both the $^{23}$Na and $^{19}$F spectra broaden substantially in
comparison to higher temperatures accompanied by a considerable reduction (80
\%) of the NMR signal intensity: This proves a broad quasi-static field
distribution. The $^{19}$F spin-lattice relaxation rate $^{19}(1/T_1$) exhibits
a peak at 2.9 K already starting to develop below 10 K. We attribute the spin
freezing to the presence of bond disorder. This is corroborated by large-scale
Monte-Carlo simulations of a classical bond-disordered XY model on the
pyrochlore lattice. The low freezing temperature, together with the very short
magnetic correlation length not captured by the simulations, suggesting that
quantum effects play a decisive role in NaCaCo$_2$F$_7$.


title:
Analysis of the carbonyl group stretching vibrations in some structural
  fragments of poly-3-hydroxybutyrate

abstract:
  The structure and the medium effects exerted on the spectral characteristics
of the carbonyl group stretching vibrations in some structural fragments of
poly-3-hydroxybutyrate have been analyzed. Calculations of the equilibrium
configurations and IR spectra were carried out using the Gaussian program set
in the approximation B3LYP/cc-pVDZ. It has been shown that typical bending of
the poly-3-hydroxybutyrate chain is observed with an increase in the number of
structural units. In order to explain the difference between the calculated and
experimental frequencies of the C=O group stretching vibrations, the
calculations of the potential energy curve associated with variations in the
length of C=O bond and the subsequent numerical solution of a one-dimensional
vibrational Schr\"odinger equation have been performed. The medium effects have
been taken into account within the scope of a polarizable continuum model.
Owing to the inclusion of the above-mentioned factors, which affect frequencies
of the carbonyl groups stretching vibrations, correlation between the
theoretical and experimental results has been improved significantly.


title:
Application of a Portable $^3$He-Based Polarization Insert at a
  Time-of-Flight Neutron Reflectometer

abstract:
  The suitability of a transportable 3He-spin filter as temporary broadband
polarizer for a Time-of-Flight neutron reflectometer is demonstrated. A simple
two-wavelength method for characterisation of a 3He-spin filter is proposed,
which can be applied even if the absolute transmittance of the 3He-spin filter
cannot be accurately determined. We demonstrate the data treatment procedure
for extracting the spin-up and spin-down neutron reflectivity from measurements
obtained with a time dependent 3He polarization. The extraction of a very weak
magnetic signal from reflectivity data, measured on the in-situ grown magnetic
heterostructure Fe1 nm/Cu20 nm/Sisubstrate in an externally applied magnetic
field of 30mT is presented and compared to similar measurements on the growth
stage Cu20 nm/Sisubstrate of the very same sample, which does not yet contain
any magnetic material.


title: Liquid gas phase transition in hypernuclei

abstract:
  The fragmentation of excited hypernuclear system formed in heavy ion
collisions has been described by the canonical thermodynamical model extended
to three component systems. The multiplicity distribution of the fragments has
been analyzed in detail and it has been observed that the hyperons have the
tendency to get attached to the heavier fragments. Another important
observation is the phase coexistence of the hyperons, a phenomenon which is
linked to liquid gas phase transition in strange matter.


title:
Cooperative communications for sleep monitoring in wireless body area
  networks

abstract:
  This paper investigates the performance of cooperative receive diversity, for
the wireless body area network (WBAN) radio channel, compliant with the IEEE
802.15.6 Standard, in the case of monitoring a sleeping person. Extensive WBAN
measurements near the 2.4 GHz ISM band were used. Up to 7 dB and 20%
improvement for two-hop communications with the use of relays are empirically
demonstrated with respect to outage probability and outage duration, with
3-branch cooperative selection combining and 3-branch cooperative
switch-and-examine combining.


title:
Approximation schemes for the study of multi-band Gutzwiller wave
  functions

abstract:
  The minimum of the Gutzwiller energy functional depends on the number of
parameters considered in the variational state. For a three-orbital Hubbard
model we find that the frequently used diagonal Ansatz is very accurate in
high-symmetry situations. For lower symmetry, induced by a crystal-field
splitting or the spin-orbit coupling, the discrepancies in energy between the
most general and a diagonal Gutzwiller Ansatz can be quite significant. We
discuss approximate schemes that may be employed in multi-band cases where a
minimization of the general Gutzwiller energy functional is too demanding
numerically.


title:
Quasinormal modes of a quantum-corrected Schwarzschild black hole:
  gravitational and Dirac perturbations

abstract:
  In this work, quasinormal modes (QNMs) of the Schwarzschild black hole are
investigated by taking into account the quantum fluctuations. Gravitational and
Dirac perturbations were considered for this case. The Regge-Wheeler gauge and
the Dirac equation were used to derive the perturbation equations of the
gravitational and Dirac fields respectively and the third order
Wentzel-Kramers-Brillouin (WKB) approximation method is used for the computing
of the quasinormal frequencies. The results show that due to the quantum
fluctuations in the background of the Schwarzschild black hole, the QNMs of the
black hole damp more slowly when increasing the quantum correction factor (a),
and oscillate more slowly.


title:
The effect of in-plane magnetic field and applied strain in quantum spin
  Hall systems: application to InAs/GaSb quantum wells

abstract:
  Motivated by the recent discovery of quantized spin Hall effect in InAs/GaSb
quantum wells\cite{du2013}$^,$\cite{xu2014}, we theoretically study the effects
of in-plane magnetic field and strain effect to the quantization of charge
conductance by using Landauer-Butikker formalism. Our theory predicts a
robustness of the conductance quantization against the magnetic field up to a
very high field of 20 tesla. We use a disordered hopping term to model the
strain and show that the strain may help the quantization of the conductance.
Relevance to the experiments will be discussed.


title: Effect of hyperons on phase coexistence in strange matter

abstract:
  The study of liquid gas phase transition in fragmentation of nuclei in heavy
ion collisions has been extended to the strangeness sector using the
statistical model for multifragmentation. Helmholtz's free energy, specific
heat and few other thermodynamic observables have been analyzed in order to
examine the occurence of phase transition in the strange matter. The bimodal
behaviour of the largest cluster formed in fragmentation also strongly
indicates coexistence of both the phases. The presence of hyperons strengthens
the signals and also shifts the transition temperature to lower values.


title:
SINOMA - A new approach for estimating linear relationships between
  noisy serial data streams

abstract:
  Reconstructions of past climates are based on the calibration of available
proxy data. This calibration is usually achieved by means of linear regression
models. In the recent paleo-climate literature there is an ongoing discussion
on the validity of highly resolved climate reconstructions. The reason for this
is that the proxy data are noisy, i.e. in addition to the variability that is
related to the climate variable of interest, they contain other sources of
variability. Inadequate treatment of such noise leads to a biased estimation of
regression slopes, resulting in a wrong representation of the real amplitude of
past climate variations. Methods to overcome this problem have had a limited
success so far. Here, we present a new approach - SINOMA - for noisy serial
data streams that are characterized by different spectral characteristics of
signal and noise. SINOMA makes use of specific properties of the data streams
temporal or spatial structure and by this is able to deliver a precise estimate
of the true regression slope and, simultaneously, of the ratio of noise
variances present in the predictor and predictand. The paper introduces the
underlying mathematics as well as a general description of the presented
algorithm. The validity of SINOMA is illustrated with two test data-sets.
Finally we address methodological limitations and further potential
applications.


title:
Reversibly switchable electromagnetic device with leakage-free
  electrolyte

abstract:
  Electrical control of oxygen off-stoichiometry of transition-metal oxides at
room temperature is a desired strategy to simultaneously switch the electrical
conductance and magnetism of the device. Although the use of the
electrochemical redox reaction of transition-metal oxides is the most
reasonable way to achieve the aforementioned switch, such a device has not been
realized because of the lack of a leakage-free liquid electrolyte. Here, we
demonstrate an electromagnetic device that can reversibly switch a
transition-metal oxide from an insulator/non-magnet to a metal/magnet (Tc=275
K) using a newly developed 'leakage-free electrolyte', incorporated in an
amorphous NaTaO3 nanopillar array film. Reversible switching occurs
electrically, obeying Faraday's laws of electrolysis, under a DC voltage of
+(-)3 V within 2-3 s at RT. The present electromagnetic device does not have
the drawback of liquid leakage, and the leakage-free electrolyte provides a
novel design concept for practical electromagnetic devices using
transition-metal oxides.


title:
Layer-wise Relevance Propagation for Neural Networks with Local
  Renormalization Layers

abstract:
  Layer-wise relevance propagation is a framework which allows to decompose the
prediction of a deep neural network computed over a sample, e.g. an image, down
to relevance scores for the single input dimensions of the sample such as
subpixels of an image. While this approach can be applied directly to
generalized linear mappings, product type non-linearities are not covered. This
paper proposes an approach to extend layer-wise relevance propagation to neural
networks with local renormalization layers, which is a very common product-type
non-linearity in convolutional neural networks. We evaluate the proposed method
for local renormalization layers on the CIFAR-10, Imagenet and MIT Places
datasets.


title:
On the Brezis-Nirenberg type critical problem for nonlinear Choquard
  equation

abstract:
  We establish some existence results for the Brezis-Nirenberg type problem of
the nonlinear Choquard equation $$-\Delta u
=\left(\int_{\Omega}\frac{|u|^{2_{\mu}^{\ast}}}{|x-y|^{\mu}}dy\right)|u|^{2_{\mu}^{\ast}-2}u+\lambda
u\4.14mm\mbox{in}\1.14mm \Omega, $$ where $\Omega$ is a bounded domain of
$\mathbb{R}^N$, with Lipschitz boundary, $\lambda$ is a real parameter,
$N\geq3$, $2_{\mu}^{\ast}=(2N-\mu)/(N-2)$ is the critical exponent in the sense
of the Hardy-Littlewood-Sobolev inequality.


title:
Scintillation light simulation in big-sized BaF$_{2}$ and pure CsI
  crystals

abstract:
  We have investigated scintillation light distribution in BaF$_{2}$ and pure
CsI crystals with dimensions 3x3x20 cm$^{3}$ using the Geant4 toolkit. The
diffuse wrapping material is selected as coating for the crystals. The
simulated cosmic muons and 105 MeV electrons are used as beam particles. The
optical attenuation along the crystals is explored with the simulation data. We
have demonstrated the impact of the crystal surface finish on the light
distribution at the crystal end, optical photon arrival time, incidence angle
distributions, and optical attenuation for the studied crystals.


title:
A general reaction network unifies the aggregation behaviour of the
  A$\beta$42 peptide and its variants

abstract:
  The amyloid $\beta$ peptide (A$\beta$42), whose aggregation is associated
with Alzheimer's disease, is an amphiphatic peptide with a high propensity to
self-assemble. A$\beta$42 has a net negative charge at physiological pH and
modulations of intermolecular electrostatic interactions can significantly
alter its aggregation behaviour. Variations in sequence and solution conditions
lead to varied macroscopic behaviour, often resulting in a number of different
mechanistic explanations for the aggregation of these closely related systems.
Here we alter the electrostatic interactions governing the fibril aggregation
kinetics by varying the ionic strength over an order of magnitude, which allows
us to sample the space of different reaction mechanisms, and develop a minimal
reaction network that explains the experimental kinetics under all the
different conditions. We find that an increase in the ionic strength leads to
an increased rate of surface catalysed nucleation over fragmentation and
eventually to a saturation of this nucleation process. More generally, this
reaction network connects previously separate systems, such as mutants of
A$\beta$42 and the wild type, on a continuous mechanistic landscape, thereby
providing a unified picture of the aggregation mechanism of A$\beta$42 and the
means of directly comparing the effects of intrinsic modifications of the
peptide to those of simple electrostatic shielding.


title:
Application of the triaxial quadrupole-octupole rotor to the ground and
  negative-parity levels of actinide nuclei

abstract:
  In this work we examine the possibility to describe yrast positive- and
negative-parity excitations of deformed even-even nuclei through a collective
rotation model in which the nuclear surface is characterized by triaxial
quadrupole and octupole deformations. The nuclear moments of inertia are
expressed as sums of quadrupole and octupole parts. By assuming an adiabatic
separation of rotation and vibration degrees of freedom we suppose that the
structure of the positive- and negative- parity bands may be determined by the
triaxial-rigid-rotor motion of the nucleus. By diagonalizing the Hamiltonian in
a symmetrized rotor basis with embedded parity we obtain a model description
for the yrast positive- and negative-parity bands in several actinide nuclei.
We show that the energy displacement between the opposite-parity sequences can
be explained as the result of the quadrupole-octupole triaxiality.


title:
Classifying Developers into Core and Peripheral: An Empirical Study on
  Count and Network Metrics

abstract:
  Knowledge about the roles developers play in a software project is crucial to
understanding the project's collaborative dynamics. Developers are often
classified according to the dichotomy of core and peripheral roles. Typically,
operationalizations based on simple counts of developer activities (e.g.,
number of commits) are used for this purpose, but there is concern regarding
their validity and ability to elicit meaningful insights. To shed light on this
issue, we investigate whether commonly used operationalizations of
core--peripheral roles produce consistent results, and we validate them with
respect to developers' perceptions by surveying 166 developers. Improving over
the state of the art, we propose a relational perspective on developer roles,
using developer networks to model the organizational structure, and by
examining core--peripheral roles in terms of developers' positions and
stability within the organizational structure. In a study of 10 substantial
open-source projects, we found that the existing and our proposed
core--peripheral operationalizations are largely consistent and valid.
Furthermore, we demonstrate that a relational perspective can reveal further
meaningful insights, such as that core developers exhibit high positional
stability, upper positions in the hierarchy, and high levels of coordination
with other core developers.


title: Active Latitude Oscillations Observed on the Sun

abstract:
  We investigate periodicities in mean heliographic latitudes of sunspot
groups, called active latitudes, for the last six complete solar cycles
(1945-2008). For this purpose, the Multi Taper Method and Morlet Wavelet
analysis methods were used. We found the following: 1) Solar rotation
periodicities (26-38 days) are present in active latitudes of both hemispheres
for all the investigated cycles (18 to 23). 2) Both in the northern and
southern hemispheres, active latitudes drifted towards the equator starting
from the beginning to the end of each cycle by following an oscillating path.
These motions are well described by a second order polynomial. 3) There are no
meaningful periods between 55 and about 300 days in either hemisphere for all
cycles. 4) A 300 to 370 day periodicity appears in both hemispheres for Cycle
23, in the northern hemisphere for Cycle 20, and in the southern hemisphere for
Cycle 18.


title: Density independent population growth with random survival

abstract:
  A simplified model for the growth of a population is studied in which random
effects arise because reproducing individuals have a certain probability of
surviving until the next breeding season and hence contributing to the next
generation. The resulting Markov chain is that of a branching process with a
known generating function. For parameter values leading to non-extinction, an
approximating diffusion process is obtained for the population size.
  Results are obtained for the number of offspring $r_h$ and the initial
population size $N_0$ required to guarantee a given probabilty of survival. For
large probabilities of survival, increasing the initial population size from
$N_0=1$ to $N_0=2$ gives a very large decrease in required fecundity but
further increases in $N_0$ lead to much smaller decreases in $r_h$. For small
probabilities (< 0.2) of survival the decreases in required fecundity when
$N_0$ changes from 1 to 2 are very small. The calculations have relevance to
the survival of populations derived from colonizing individuals which could be
any of a variety of organisms.


title:
Obstacle Avoidance Strategy using Onboard Stereo Vision on a Flapping
  Wing MAV

abstract:
  The development of autonomous lightweight MAVs, capable of navigating in
unknown indoor environments, is one of the major challenges in robotics. The
complexity of this challenge comes from constraints on weight and power
consumption of onboard sensing and processing devices. In this paper we propose
the "Droplet" strategy, an avoidance strategy based on stereo vision inputs
that outperforms reactive avoidance strategies by allowing constant speed
maneuvers while being computationally extremely efficient, and which does not
need to store previous images or maps. The strategy deals with nonholonomic
motion constraints of most fixed and flapping wing platforms, and with the
limited field-of-view of stereo camera systems. It guarantees obstacle-free
flight in the absence of sensor and motor noise. We first analyze the strategy
in simulation, and then show its robustness in real-world conditions by
implementing it on a 20-gram flapping wing MAV.


title: In narrative texts punctuation marks obey the same statistics as words

abstract:
  From a grammar point of view, the role of punctuation marks in a sentence is
formally defined and well understood. In semantic analysis punctuation plays
also a crucial role as a method of avoiding ambiguity of the meaning. A
different situation can be observed in the statistical analyses of language
samples, where the decision on whether the punctuation marks should be
considered or should be neglected is seen rather as arbitrary and at present it
belongs to a researcher's preference. An objective of this work is to shed some
light onto this problem by providing us with an answer to the question whether
the punctuation marks may be treated as ordinary words and whether they should
be included in any analysis of the word co-occurences. We already know from our
previous study (S.~Dro\.zd\.z {\it et al.}, Inf. Sci. 331 (2016) 32-44) that
full stops that determine the length of sentences are the main carrier of
long-range correlations. Now we extend that study and analyze statistical
properties of the most common punctuation marks in a few Indo-European
languages, investigate their frequencies, and locate them accordingly in the
Zipf rank-frequency plots as well as study their role in the word-adjacency
networks. We show that, from a statistical viewpoint, the punctuation marks
reveal properties that are qualitatively similar to the properties of the most
frequent words like articles, conjunctions, pronouns, and prepositions. This
refers to both the Zipfian analysis and the network analysis. By adding the
punctuation marks to the Zipf plots, we also show that these plots that are
normally described by the Zipf-Mandelbrot distribution largely restore the
power-law Zipfian behaviour for the most frequent items.