title: Possible nonplanar structure of phagraphene and its thermal stability

abstract:
  It is shown that phagraphene, a recently predicted planar allotrope of
graphene with Dirac fermions, is unstable or, at least, almost unstable with
respect to transverse atomic displacements. This result is obtained by
numerical calculations in the framework of both the tight-binding model and the
density functional theory. A nonplanar atomic configuration of phagraphene has
a wavy shape and is almost degenerate in energy with the planar configuration.
The main types of possible structural defects in phagraphene are determined.
The temperature dependence of characteristic times of their formation is found.


title:
Interlayer exchange coupling -- a general scheme turning chiral magnets
  into magnetic multilayers carrying atomic-scale skyrmions

abstract:
  We report on a general principle using the interlayer exchange coupling to
extend the regime of chiral magnetic films in which stable or metastable
magnetic skyrmions can appear at zero magnetic field. We verify this concept on
the basis of a first-principles model for a Mn monolayer on W(001) substrate, a
prototype chiral magnet for which the atomic-scale magnetic texture is
determined by the frustration of exchange interactions, impossible to unwind by
laboratory magnetic fields. By means of \textit{ab initio} calculations for the
Mn/W$_m$/Co$_n$/Pt/W(001) multilayer system we show that for certain
thicknesses $m$ of the W spacer and $n$ of the Co reference layer, the
effective field of the reference layer fully substitutes the required magnetic
field for skyrmion formation.


title: A relation between diffusion,temperature and the cosmological constant

abstract:
  We show that the temperature of a diffusing fluid with the diffusion constant
\kappa^{2} in an expanding universe approaches a constant limit T=\kappa^{2}/H
in its final de Sitter stage characterized by the horizon 1/H determined by the
Hubble constant. If de Sitter surface temperature in the final equilibrium
state coincides with the fluid temperature then the cosmological constant
\Lambda=3H^{2}=6\pi\kappa^{2}.


title: Alpha invariants of birationally rigid Fano threefolds

abstract:
  We compute global log canonical thresholds, or equivalently alpha invariants,
of birationally rigid orbifold Fano threefolds embedded in weighted projective
spaces as codimension two or three. As an important application, we prove that
most of them are weakly exceptional, $K$-stable and admit K\"{a}hler--Einstien
metric.


title:
Integrated Control/Structure Design of a Large Space Structure using
  Structured $\mathcal{H}_\infty$ Control

abstract:
  This study presents the integrated control/structure design of a Large
Flexible Structure, the Extra Long Mast Observatory (ELMO). The integrated
design is performed using structured $\mathcal{H}_\infty$ control tools,
developing the Two-Input Two-Output Port (TITOP) model of the flexible
multi-body structure and imposing integrated design specifications as
$\mathcal{H}_\infty$ constraints. The integrated control/structure design for
ELMO consists of optimizing simultaneously its payload mass and control system
for low-frequency perturbation rejection respecting bandwidth requirements.


title: Systemic Risks in CCP Networks

abstract:
  We propose a model for the credit and liquidity risks faced by clearing
members of Central Counterparty Clearing houses (CCPs). This model aims to
capture the features of: gap risk; feedback between clearing member default,
market volatility and margining requirements; the different risks faced by
various types of market participant and the changes in margining requirements a
clearing member faces as the system evolves. By considering the entire network
of CCPs and clearing members, we investigate the distribution of losses to
default fund contributions and contingent liquidity requirements for each
clearing member; further, we identify wrong-way risks between defaults of
clearing members and market turbulence.


title:
Network structure, metadata and the prediction of missing nodes and
  annotations

abstract:
  The empirical validation of community detection methods is often based on
available annotations on the nodes that serve as putative indicators of the
large-scale network structure. Most often, the suitability of the annotations
as topological descriptors itself is not assessed, and without this it is not
possible to ultimately distinguish between actual shortcomings of the community
detection algorithms on one hand, and the incompleteness, inaccuracy or
structured nature of the data annotations themselves on the other. In this work
we present a principled method to access both aspects simultaneously. We
construct a joint generative model for the data and metadata, and a
nonparametric Bayesian framework to infer its parameters from annotated
datasets. We assess the quality of the metadata not according to its direct
alignment with the network communities, but rather in its capacity to predict
the placement of edges in the network. We also show how this feature can be
used to predict the connections to missing nodes when only the metadata is
available, as well as missing metadata. By investigating a wide range of
datasets, we show that while there are seldom exact agreements between metadata
tokens and the inferred data groups, the metadata is often informative of the
network structure nevertheless, and can improve the prediction of missing
nodes. This shows that the method uncovers meaningful patterns in both the data
and metadata, without requiring or expecting a perfect agreement between the
two.


title:
How to separate the low amplitude delta Scuti variation from the
  instrumental ones in CoRoT data?

abstract:
  Rich regular frequency patterns were found in the Fourier spectra of
low-amplitude delta Scuti stars observed by CoRoT satellite (see Papar\'o et
al. 2016a,b). The CoRoT observations are, however, influenced by the disturbing
effect of the South Atlantic Anomaly. The effect is marginal for high amplitude
variable stars but it could be critical in the case of low amplitude variables,
especially if the frequency range of the intrinsic variation overlaps the
interval of the instrumental frequencies. Some tests were carried out both on
synthetic and real data for distinguishing technical and stars' frequencies.


title:
A mass, energy, enstrophy and vorticity conserving (MEEVC) mimetic
  spectral element discretization for the 2D incompressible Navier-Stokes
  equations

abstract:
  In this work we present a mimetic spectral element discretization for the 2D
incompressible Navier-Stokes equations that in the limit of vanishing
dissipation exactly preserves mass, kinetic energy, enstrophy and total
vorticity on unstructured grids. The essential ingredients to achieve this are:
(i) a velocity-vorticity formulation in rotational form, (ii) a sequence of
function spaces capable of exactly satisfying the divergence free nature of the
velocity field, and (iii) a conserving time integrator. Proofs for the exact
discrete conservation properties are presented together with numerical test
cases on highly irregular grids.


title:
Computable dyadic subbases and $\mathbf{T}^\omega$-representations of
  compact sets

abstract:
  We explore representing the compact subsets of a given represented space by
infinite sequences over Plotkin's $\mathbb{T}$. We show that computably compact
computable metric spaces admit representations of their compact subsets in such
a way that compact sets are essentially underspecified points. We can even
ensure that a name of an $n$-element compact set contains $n$ occurrences of
$\bot$. We undergo this study effectively and show that such a
$\mathbb{T}^\omega$-representation is effectively obtained from structures of
computably compact computable metric spaces. As an application, we prove some
statements about the Weihrauch degree of closed choice for finite subsets of
computably compact computable metric spaces.
  Along the way, we introduce the notion of a computable dyadic subbase, and
prove that every computably compact computable metric space admits a proper
computable dyadic subbase.


title:
Flexible Multibody System Linear Modeling for Control using Component
  Modes Synthesis and Double-Port Approach

abstract:
  The main objective of this study is to propose a methodology to build a
parametric linear model of Flexible Multibody Systems for control design. This
approach uses a combined Finite Element - State Space Approach based on
component modes synthesis and double-port approach. The proposed scheme offers
the advantage of automatic assembly of substructures, preserving the elastic
dynamical behavior of the whole system. Substructures are connected following
the double-port approach; i.e, through the transfer of accelerations and loads
at the connection points, which take into account the dynamic coupling among
them. In addition, parametric variations can be included in the model for
accomplishing integrated control/structure design purposes. The method can be
applied to combinations of chain-like or/and star-like flexible systems, and it
is validated through its comparison with the assumed modes method for the case
of a rotatory spacecraft.


title: Archaeoastronomy and the orientation of old churches

abstract:
  Cultural astronomy is an interdisciplinary area of research that studies how
perceptions and concepts related to the sky are part of the worldview of a
culture. One of its branches, archaeoastronomy, focuses on the material remains
of past peoples and tries to investigate their practices and astronomical
knowledge. In this context, the orientation of Christian churches is now
considered a distinctive feature of their architecture that repeats patterns
from early Christian times. There is a general tendency to align their altars
in the solar range, with preference for orientations towards the east. Here we
present recent data from our measurements of astronomical orientations of old
churches located in two --geographically and culturally-- very distant regions,
and we discuss the results in the light of the historical and cultural
knowledge surrounding these temples.


title:
Product rules are optimal for numerical integration in classical
  smoothness spaces

abstract:
  We mainly study numerical integration of real valued functions defined on the
$d$-dimensional unit cube with all partial derivatives up to some finite order
$r\ge1$ bounded by one. It is well known that optimal algorithms that use $n$
function values achieve the error rate $n^{-r/d}$, where the hidden constant
depends on $r$ and $d$. Here we prove explicit error bounds without hidden
constants and, in particular, show that the optimal order of the error is $\min
\bigl\{1, d \, n^{-r/d}\bigr\}$, where now the hidden constant only depends on
$r$, not on $d$. For $n=m^d$, this optimal order can be achieved by (tensor)
product rules.
  We also provide lower bounds for integration defined over an arbitrary open
domain of volume one. We briefly discuss how lower bounds for integration may
be applied for other problems such as multivariate approximation and
optimization.


title: A generalized finite element method for linear thermoelasticity

abstract:
  We propose and analyze a generalized finite element method designed for
linear quasistatic thermoelastic systems with spatial multiscale coefficients.
The method is based on the local orthogonal decomposition technique introduced
by M{\aa}lqvist and Peterseim (Math. Comp., 83(290): 2583--2603, 2014). We
prove convergence of optimal order, independent of the derivatives of the
coefficients, in the spatial $H^1$-norm. The theoretical results are confirmed
by numerical examples.


title: Generalised Maxwellian Equations and their Implications

abstract:
  We present a reformulation of Mawxell's equation and examine the consequence
of this new formulation. We argue that studies of such diverse topics as
magnetic monopole, magnetic recombination and magneto-genesis could benefit
from the new formulation.


title: Linear growth in power law $f(T)$ gravity

abstract:
  We provide for the first time the growth index of linear matter fluctuations
of the power law $f(T) \propto (-T)^{b}$ gravity model. We find that the
asymptotic form of this particular $f(T)$ model is $\gamma \approx
\frac{6}{11-6b}$ which obviously extends that of the $\Lambda$CDM model,
$\gamma_{\Lambda}\approx 6/11$. Finally, we generalize the growth index
analysis of $f(T)$ gravity in the case where $\gamma$ is allowed to vary with
redshift.


title:
Non-separability and steerability of two-qubit states from the geometry
  of steering outcomes

abstract:
  When two qubits A and B are in an appropriate state, Alice can remotely steer
Bob's system B into different ensembles by making different measurements on A.
This famous phenomenon is known as quantum steering, or Einstein-Podolsky-Rosen
steering. Importantly, quantum steering establishes the correspondence not only
between a measurement on A (made by Alice) and an ensemble of B (owned by Bob)
but also between each of Alice's measurement outcomes and an unnormalized
conditional state of Bob's system. The unnormalized conditional states of B
corresponding to all possible measurement outcomes of Alice are called Alice's
steering outcomes. We show that, surprisingly, the $4$-dimensional geometry of
Alice's steering outcomes completely determines both the non-separability of
the two-qubit state and its steerability from her side. Consequently, the
problem of classifying two-qubit states into non-separable and steerable
classes is equivalent to geometrically classifying certain $4$-dimensional
skewed double-cones.


title:
The Algorithm of Islamic Jurisprudence (Fiqh) with Validation of an
  Entscheidungsproblem

abstract:
  The historic background of algorithmic processing with regard to etymology
and methodology is translated into terms of mathematical logic and Computer
Science. A formal logic structure is introduced by exemplaryquestions posed to
Fiqh-chapters to define alogic query language. As a foundation, ageneric
algorithm for deciding Fiqh-rulings is designed to enable and further leverage
rule of law (vs. rule by law) with full transparency and complete algorithmic
coverage of Islamic law eventually providing legal security, legal equality,
and full legal accountability.This is implemented by disentangling and
reinstating classic Fiqh-methodology (usul al-Fiqh) with the expressive power
of subsets of First Order Logic (FOL)sustainably substituting ad hoc reasoning
with falsifiable rational argumentation. The results are discussed in formal
terms of completeness, decidability and complexity of formal Fiqh-systems.
AnEntscheidungsproblem for formal Fiqh-Systems is formulated and validated.


title: Numerical multi-loop calculations: tools and applications

abstract:
  We report on the development of tools to calculate loop integrals and
amplitudes beyond one loop. In particular, we review new features of the
program SecDec which can be used for the numerical evaluation of parametric
integrals like multi-loop integrals.


title: The deterministic information bottleneck

abstract:
  Lossy compression and clustering fundamentally involve a decision about what
features are relevant and which are not. The information bottleneck method (IB)
by Tishby, Pereira, and Bialek formalized this notion as an
information-theoretic optimization problem and proposed an optimal tradeoff
between throwing away as many bits as possible, and selectively keeping those
that are most important. In the IB, compression is measure my mutual
information. Here, we introduce an alternative formulation that replaces mutual
information with entropy, which we call the deterministic information
bottleneck (DIB), that we argue better captures this notion of compression. As
suggested by its name, the solution to the DIB problem turns out to be a
deterministic encoder, or hard clustering, as opposed to the stochastic
encoder, or soft clustering, that is optimal under the IB. We compare the IB
and DIB on synthetic data, showing that the IB and DIB perform similarly in
terms of the IB cost function, but that the DIB significantly outperforms the
IB in terms of the DIB cost function. We also empirically find that the DIB
offers a considerable gain in computational efficiency over the IB, over a
range of convergence parameters. Our derivation of the DIB also suggests a
method for continuously interpolating between the soft clustering of the IB and
the hard clustering of the DIB.

categories: q-bio.NC cond-mat.stat-mech cs.IT math.IT q-bio.QM stat.ML


title: Dynamical Analysis of Anisotropic Inflation

abstract:
  Inflaton coupling to a vector field via the $f^2(\phi)F_{\mu\nu}F^{\mu\nu}$
term is used in several contexts in the literature, such as to generate
primordial magnetic fields, to produce statistically anisotropic curvature
perturbation, to support anisotropic inflation and to circumvent the
$\eta$-problem. Here, I perform dynamical analysis of such a system allowing
for most general Bianchi I initial conditions. I also confirm the stability of
attractor equilibrium points in phase-space directions that had not been
investigated before.


title: Functions with strictly convex epigraph

abstract:
  The aim of this paper is to provide a complete and simple characterization of
functions with domain in a topological real vector space whose epigraph is
strictly convex.


title:
Synergies between SALT and Herschel, Euclid & the SKA: strong
  gravitational lensing & galaxy evolution

abstract:
  Gravitational lensing has seen a surge of interest in the past few years. The
handful of strong lensing systems known in the year 2000 has now been replaced
with hundreds, thanks to innovative multi-wavelength selection, and there is an
imminent prospect of thousands of lenses from Herschel and other sub-millimetre
surveys. Euclid and the Square Kilometre Array promise tens or even hundreds of
thousands. Gravitational lensing is one of the very few probes capable of
mapping dark matter halo distributions. Lensing also provides independent
cosmological parameter estimates and enables the study of galaxy populations
that are otherwise too faint for detailed study. SALT is extremely well placed
to have an enormous impact with follow-up observations of foreground lenses and
background sources from e.g. Herschel, the South Pole Telescope, the Atacama
Cosmology Telescope, Euclid and the Square Kilometre Array. This paper reviews
the prospects for high-impact SALT science and the many constraints of galaxy
evolution that can result.


title: Extension of Matrix Pencil Reduction to Abelian Categories

abstract:
  Matrix pencils, or pairs of matrices, are used in a variety of applications.
By the Kronecker decomposition Theorem, they admit a normal form. This normal
form consists of four parts, one part based on the Jordan canonical form, one
part made of nilpotent matrices, and two other dual parts, which we call the
observation and control part. The goal of this paper is to show that large
portions of that decomposition are still valid for pairs of morphisms of
modules or abelian groups, and more generally in any abelian category. % This
gives a new perspective even in the vector space case, as we have to use
radically new proof techniques to work on abelian categories. In the vector
space case, we recover the full Kronecker decomposition theorem. The main
technique is that of reduction, which extends readily to the abelian category
case. Reductions naturally arise in two flavours, which are dual to each other.
There are a number of properties of those reductions which extend remarkably
from the vector space case to abelian categories. First, both types of
reduction commute. Second, at each step of the reduction, one can compute three
sequences of invariant spaces (objects in the category), which generalize the
Kronecker decomposition into nilpotent, observation and control blocks. These
sequences indicate whether the system is reduced in one direction or the other.
In the category of modules, there is also a relation between these sequences
and the resolvent set of the pair of morphisms, which generalizes the regular
pencil theorem. We also indicate how this allows to define invariant subspaces
in the vector space case, and study the notion of strangeness as an example.


title:
Demonstrating topoS: Theorem-Prover-Based Synthesis of Secure Network
  Configurations

abstract:
  In network management, when it comes to security breaches, human error
constitutes a dominant factor. We present our tool topoS which automatically
synthesizes low-level network configurations from high-level security goals.
The automation and a feedback loop help to prevent human errors. Except for a
last serialization step, topoS is formally verified with Isabelle/HOL, which
prevents implementation errors. In a case study, we demonstrate topoS by
example. For the first time, the complete transition from high-level security
goals to both firewall and SDN configurations is presented.


title:
Half-Duplex or Full-Duplex Communications: Degrees of Freedom Analysis
  under Self-Interference

abstract:
  In-band full-duplex (FD) communication provides a promising alternative to
half-duplex (HD) for wireless systems, due to increased spectral efficiency and
capacity. In this paper, HD and FD radio implementations of two way, two hop
and two way two hop communication are compared in terms of degrees of freedom
(DoF) under a realistic residual self-interference (SI) model. DoF analysis is
carried out for each communication scenario for HD, antenna conserved (AC) and
RF chain conserved (RC) FD radio implementations. The DoF analysis indicates
that for the two way channel, the achievable AC FD with imperfect SI
cancellation performs strictly below HD, and RC FD DoF trade-off is superior
when the SI can be sufficiently cancelled. For the two hop channel, FD is
better when the relay has large number of antennas and enough SI cancellation.
For the two way two hop channel, when both nodes require similar throughput,
the achievable DoF pairs for FD do not outperform HD. FD still can achieve
better DoF pairs than HD, provided the relay has sufficient number of antennas
and SI suppression.


title:
Joint Resource Allocation for OFDMA based Overlay Cognitive Radio
  Networks under Stochastic Rate Constraint

abstract:
  This work presents joint subcarrier, power and bit allocation schemes for
multi-user OFDM based overlay cognitive radio under constraints on primary user
throughput loss and total secondary user transmitted power. Closed form for
expressions for the optimal power and bit allocations are initially derived.
Subsequently, optimal and suboptimal algorithms to realise the joint
subcarrier, power and bit allocations are introduced. Numerical simulations are
used to evaluate the performance of the joint resource allocation algorithms.


title: Results from the October 2014 CERN test beam of LumiCal

abstract:
  A prototype of a luminometer, designed for a future e+e- collider detector,
was tested in the CERN PS accelerator T9 testbeam. The objective of this test
beam was to demonstrate a multi-plane operation, to study the development of
the electromagnetic shower and to compare it with MC simulations.


title: 12, 24 and Beyond

abstract:
  We generalize the well-known "12" and "24" Theorems for reflexive polytopes
of dimension 2 and 3 to any smooth reflexive polytope. Our methods apply to a
wider category of objects, here called reflexive GKM graphs, that are
associated with certain monotone symplectic manifolds which do not necessarily
admit a toric action. As an application, we provide bounds on the Betti numbers
for certain monotone Hamiltonian spaces which depend on the minimal Chern
number of the manifold.


title:
Modeling non-harmonic behavior of materials from experimental inelastic
  neutron scattering and thermal expansion measurements

abstract:
  Based on thermodynamic principles, we derive expressions quantifying the
non-harmonic vibrational behavior of materials, which are rigorous yet easily
evaluated from experimentally available data for the thermal expansion
coefficient and the phonon density of states. These experimentally- derived
quantities are valuable to benchmark first-principles theoretical predictions
of harmonic and non-harmonic thermal behaviors using perturbation theory, ab
initio molecular-dynamics, or Monte-Carlo simulations. We illustrate this
analysis by computing the harmonic, dilational, and anharmonic contributions to
the entropy, internal energy, and free energy of elemental aluminum and the
ordered compound FeSi over a wide range of temperature. Results agree well with
previous data in the literature and provide an efficient approach to estimate
anharmonic effects in materials.


title:
Using Recurrent Neural Networks to Optimize Dynamical Decoupling for
  Quantum Memory

abstract:
  We utilize machine learning models which are based on recurrent neural
networks to optimize dynamical decoupling (DD) sequences. DD is a relatively
simple technique for suppressing the errors in quantum memory for certain noise
models. In numerical simulations, we show that with minimum use of prior
knowledge and starting from random sequences, the models are able to improve
over time and eventually output DD-sequences with performance better than that
of the well known DD-families. Furthermore, our algorithm is easy to implement
in experiments to find solutions tailored to the specific hardware, as it
treats the figure of merit as a black box.


title: On Sobolev's mappings on Riemann surfaces

abstract:
  In terms of dilatations, it is proved a series of criteria for continuous and
homeomorphic extension to the boundary of mappings with finite distortion
between regular domains on the Riemann surfaces


title: Integers divisible by a large shifted prime

abstract:
  Let $N(x,y)$ denote the number of integers $n\le x$ which are divisible by a
shifted prime $p-1$ with $p>y$, $p$ prime. Improving upon recent bounds of
McNew, Pollack and Pomerance, we establish the exact order of growth of
$N(x,y)$ for all $x\ge 2y\ge 4$.


title:
Strong Gravitational Lenses and Multi-Wavelength Galaxy Surveys with
  AKARI, Herschel, SPICA and Euclid

abstract:
  Submillimetre and millimetre-wave surveys with Herschel and the South Pole
Telescope have revolutionised the discovery of strong gravitational lenses.
Their follow-ups have been greatly facilitated by the multi-wavelength
supplementary data in the survey fields. The forthcoming Euclid
optical/near-infrared space telescope will also detect strong gravitational
lenses in large numbers, and orbital constraints are likely to require placing
its deep survey at the North Ecliptic Pole (the natural deep field for a wide
class of ground-based and space-based observatories including AKARI, JWST and
SPICA). In this paper I review the current status of the multi-wavelength
survey coverage in the NEP, and discuss the prospects for the detection of
strong gravitational lenses in forthcoming or proposed facilities such as
Euclid, FIRSPEX and SPICA.


title:
Corruption and Wealth: Unveiling a national prosperity syndrome in
  Europe

abstract:
  Data mining revealed a cluster of economic, psychological, social and
cultural indicators that in combination predicted corruption and wealth of
European nations. This prosperity syndrome of self-reliant citizens, efficient
division of labor, a sophisticated scientific community, and respect for the
law, was clearly distinct from that of poor countries that had a diffuse
relationship between high corruption perception, low GDP/capita, high social
inequality, low scientific development, reliance on family and friends, and
languages with many words for guilt. This suggests that there are many ways for
a nation to be poor, but few ones to become rich, supporting the existence of
synergistic interactions between the components in the prosperity syndrome
favoring economic growth. No single feature was responsible for national
prosperity. Focusing on synergies rather than on single features should improve
our understanding of the transition from poverty and corruption to prosperity
in European nations and elsewhere.


title: Riemann-Roch isometries in the non-compact orbifold setting

abstract:
  We generalize work of Deligne and Gillet-Soul\'e on a Riemann-Roch type
isometry, to the case of the trivial sheaf on cusp compactifications of Riemann
surfaces $\Gamma\backslash\mathbb{H}$, for $\Gamma\subset PSL_{2}(\mathbb{R})$
a fuchsian group of the first kind, equipped with the Poincar\'e metric. This
metric is singular at cusps and elliptic fixed points, and the results of
Deligne and Gillet-Soul\'e do not apply to this setting. Our theorem relates
the determinant of cohomology of the trivial sheaf, with an explicit Quillen
type metric in terms of the Selberg zeta function of $\Gamma$, to a metrized
version of the $\psi$ line bundle of the theory of moduli spaces of pointed
orbicurves, and the self-intersection bundle of a suitable twist of the
canonical sheaf $\omega_{X}$. We make use of surgery techniques through
Mayer-Vietoris formulae for determinants of laplacians, in order to reduce to
explicit evaluations of such for model hyperbolic cusps and cones. We derive an
arithmetic Riemann-Roch formula, that applies in particular to integral models
of modular curves with elliptic fixed points. As an application, we treat in
detail the case of the modular curve $X(1)$. From this, we obtain the Selberg
zeta special value $Z^{\prime}(1,PSL_{2}(\mathbb{Z}))$ in terms of logarithmic
derivatives of Dirichlet $L$ functions. Our work finds its place in the program
initiated by Burgos-Kramer-K\"uhn of extending arithmetic intersection theory
to singular hermitian vector bundles.


title:
An implicit boundary integral method for interfaces evolving by
  Mullins-Sekerka dynamics

abstract:
  We present an algorithm for computing the nonlinear interface dynamics of the
Mullins-Sekerka model for interfaces that are defined implicitly (e.g. by a
level set function) using integral equations . The computation of the dynamics
involves solving Laplace's equation with Dirichlet boundary conditions on
multiply connected and unbounded domains and propagating the interface using a
normal velocity obtained from the solution of the PDE at each time step. Our
method is based on a simple formulation for implicit interfaces, which rewrites
boundary integrals as volume integrals over the entire space. The resulting
algorithm thus inherits the benefits of both level set methods and boundary
integral methods to simulate the nonlocal front propagation problem with
possible topological changes. We present numerical results in both two and
three dimensions to demonstrate the effectiveness of the algorithm.


title:
Structural and magnetic field effects on spin fluctuations in
  Sr$_{3}$Ru$_2$O$_7$

abstract:
  We investigate the evolution of magnetic excitations in Sr$_3$Ru$_2$O$_7$
using a three band tight binding model that takes into account the influence of
Mn and Ti dopant ions. The effect of dopant ions on the Sr$_3$Ru$_2$O$_7$ band
structure has been included by taking into account the dopant induced
suppression of the oxygen octahedral rotation in the tight binding band
structure and changes in electron occupation. We find that the low energy spin
fluctuations are dominated by three wave vectors around
Q=$((0,0),(\pi/2,\pi/2))$, and $(\pi,0)$ which compete with each other. As the
octahedral rotation is suppressed with increasing doping, the three wave
vectors evolve differently. In particular, the undoped compound has dominant
wavevectors at Q=$((0,0),(\pi/2,\pi/2))$, but doping Sr$_3$Ru$_2$O$_7$ leads to
a significant enhancement in the spin susceptibility at the Q=$(\pi,0)$
wavevector bringing the system closer to a magnetic instability. All the
features calculated from our model are in agreement with neutron scattering
experiments. We have also studied the effect of a c-axis Zeeman field on the
low energy spin fluctuations. We find that an increasing magnetic field
suppresses the AFM fluctuations and leads to stronger competition between the
AFM and FM spin fluctuations. The magnetic field dependence observed in our
calculations therefore supports the scenario that the observed nematic phase in
the metamagnetic region in Sr$_3$Ru$_2$O$_7$ is intimately related to the
presence of a competing ferromagnetic instability.


title:
Analysis of a Cahn--Hilliard system with non-zero Dirichlet conditions
  modeling tumor growth with chemotaxis

abstract:
  We consider a diffuse interface model for tumor growth consisting of a
Cahn--Hilliard equation with source terms coupled to a reaction-diffusion
equation, which models a tumor growing in the presence of a nutrient species
and surrounded by healthy tissue. The well-posedness of the system equipped
with Neumann boundary conditions was found to require regular potentials with
quadratic growth. In this work, Dirichlet boundary conditions are considered,
and we establish the well-posedness of the system for regular potentials with
higher polynomial growth and also for singular potentials. New difficulties are
encountered due to the higher polynomial growth, but for regular potentials, we
retain the continuous dependence on initial and boundary data for the chemical
potential and for the order parameter in strong norms as established in the
previous work. Furthermore, we deduce the well-posedness of a variant of the
model with quasi-static nutrient by rigorously passing to the limit where the
ratio of the nutrient diffusion time-scale to the tumor doubling time-scale is
small.


title:
Transverse instability of periodic and generalized solitary waves for a
  fifth-order KP model

abstract:
  We consider a fifth-order Kadomtsev-Petviashvili equation which arises as a
two-dimensional model in the classical water-wave problem. This equation
possesses a family of generalized line solitary waves which decay exponentially
to periodic waves at infinity. We prove that these solitary waves are
transversely spectrally unstable and that this instability is induced by the
transverse instability of the periodic tails. We rely upon a detailed spectral
analysis of some suitably chosen linear operators.


title: Building Machines That Learn and Think Like People

abstract:
  Recent progress in artificial intelligence (AI) has renewed interest in
building systems that learn and think like people. Many advances have come from
using deep neural networks trained end-to-end in tasks such as object
recognition, video games, and board games, achieving performance that equals or
even beats humans in some respects. Despite their biological inspiration and
performance achievements, these systems differ from human intelligence in
crucial ways. We review progress in cognitive science suggesting that truly
human-like learning and thinking machines will have to reach beyond current
engineering trends in both what they learn, and how they learn it.
Specifically, we argue that these machines should (a) build causal models of
the world that support explanation and understanding, rather than merely
solving pattern recognition problems; (b) ground learning in intuitive theories
of physics and psychology, to support and enrich the knowledge that is learned;
and (c) harness compositionality and learning-to-learn to rapidly acquire and
generalize knowledge to new tasks and situations. We suggest concrete
challenges and promising routes towards these goals that can combine the
strengths of recent neural network advances with more structured cognitive
models.


title: The efficient certification of knottedness and Thurston norm

abstract:
  We show that the problem of determining whether a knot in the 3-sphere is
non-trivial lies in NP. This is a consequence of the following more general
result. The problem of determining whether the Thurston norm of a second
homology class in a compact orientable 3-manifold is equal to a given integer
is in NP. As a corollary, the problem of determining the genus of a knot in the
3-sphere is in NP. We also show that the problem of determining whether a
compact orientable 3-manifold has incompressible boundary is in NP.


title: Dissipation process of binary mixture gas in thermally relativistic flow

abstract:
  In this paper, we discuss dissipation process of the binary mixture gas in
the thermally relativistic flow \textcolor{red}{by focusing on the
characteristics of the diffusion flux}. As an analytical object, we consider
the relativistic rarefied-shock layer problem around the triangle prism.
Numerical results of the diffusion flux are compared with the
Navier-Stokes-Fourier (NSF) order approximation of the diffusion flux, which is
calculated using the diffusion and thermal-diffusion coefficients by Kox
\textit{et al}. [Physica A, 84, 1, pp.165-174 (1976)]. In the case of the
uniform flow with the small Lorentz contraction, the diffusion flux, which is
obtained by calculating the relativistic Boltzmann equation, is roughly
approximated by the NSF order approximation inside the shock wave, whereas the
diffusion flux in the vicinity of the wall is markedly different from the NSF
order approximation. The magnitude of the diffusion flux, which is obtained by
calculating the relativistic Boltzmann equation, is similar to that of the NSF
order approximation inside the shock wave, unlike the pressure deviator,
dynamic pressure and heat flux, even when the Lorentz contraction in the
uniform flow becomes large, because the diffusion flux does not depend on the
generic Knudsen number from its definition in Eckart's frame.
\textcolor{red}{Finally, the author concludes that the accurate diffusion flux
must be calculated from the particle four flow, which is formulated using the
four velocity distinguished by each species of particles.


title: An effective field theory approach to hybrids

abstract:
  Heavy quarkonium hybrids are studied in an effective field theory framework.
Coupled and uncoupled Schr\"odinger equations are obtained for different
quantum numbers of the hybrid states. The results are discussed and compared to
other approaches.


title: Non-symmetric perturbations of self-adjoint operators

abstract:
  We investigate the effect of non-symmetric relatively bounded perturbations
on the spectrum of self-adjoint operators. In particular, we establish
stability theorems for one or infinitely many spectral gaps along with
corresponding resolvent estimates. These results extend, and improve, classical
perturbation results by Kato and by Gohberg/Krein. Further, we study essential
spectral gaps and perturbations exhibiting additional structure with respect to
the unperturbed operator; in the latter case, we can even allow for
perturbations with relative bound $\ge 1$. The generality of our results is
illustrated by several applications, massive and massless Dirac operators,
point-coupled periodic systems, and two-channel Hamiltonians with dissipation.


title:
Local measurement of error field using naturally rotating tearing mode
  dynamics in EXTRAP T2R

abstract:
  An error field (EF) detection technique using the amplitude modulation of a
naturally rotating tearing mode (TM) is developed and validated in the EXTRAP
T2R reversed field pinch. The technique was used to identify intrinsic EFs of
$m/n = 1/-12$, where $m$ and $n$ are the poloidal and toroidal mode numbers.
The effect of the EF and of a resonant magnetic perturbation (RMP) on the TM,
in particular on amplitude modulation, is modeled with a first-order solution
of the Modified Rutherford Equation. In the experiment, the TM amplitude is
measured as a function of the toroidal angle as the TM rotates rapidly in the
presence of an unknown EF and a known, deliberately applied RMP. The RMP
amplitude is fixed while the toroidal phase is varied from one discharge to the
other, completing a full toroidal scan. Using three such scans with different
RMP amplitudes, the EF amplitude and phase are inferred from the phases at
which the TM amplitude maximizes. The estimated EF amplitude is consistent with
other estimates (e.g. based on the best EF-cancelling RMP, resulting in the
fastest TM rotation). A passive variant of this technique is also presented,
where no RMPs are applied, and the EF phase is deduced.


title: A Strengthening of Theorems of Hal\'asz and Wirsing

abstract:
  Given an arithmetic function $g(n)$ write $M_g(x) := \sum_{n \leq x} g(n)$.
We extend and strengthen the results of a fundamental paper of Hal\'{a}sz in
several ways by proving upper bounds for the ratio of
$\frac{|M_g(x)|}{M_{|g|}(x)}$, for any strongly multiplicative, complex-valued
function $g(n)$ under certain assumptions on the sequence $\{g(p)\}_p$. We
further prove an asymptotic formula for this ratio in the case that
$|\text{arg}(g(p))|$ is sufficiently small uniformly in $p$. In so doing, we
recover a new proof of an explicit lower mean value estimate for $M_{f}(x)$ for
any non-negative, multiplicative function satisfying $c_1 \leq |f(p)| \leq c_2$
for $c_2 \geq c_1 > 0$, by relating it to $\frac{x}{\log x}\prod_{p \leq x}
\left(1+\frac{f(p)}{p}\right)$. As an application, we generalize our main
theorem in such a way as to give explicit estimates for the ratio
$\frac{|M_g(x)|}{M_{f}(x)}$, whenever $f: \mathbb{N} \rightarrow (0,\infty)$
and $g: \mathbb{N} \rightarrow \mathbb{C}$ are strongly multiplicative
functions that are uniformly bounded on primes and satisfy $|g(n)| \leq f(n)$
for every $n \in \mathbb{N}$. This generalizes a theorem of Wirsing and extends
recent work due to Elliott.


title:
Predictions on the alpha decay half lives of Superheavy nuclei with Z =
  113 in the range 255 l.e. A l.e. 314

abstract:
  An intense study of the alpha decay properties of the isotopes of superheavy
element Z=113 have been performed within the Coulomb and proximity potential
model for deformed nuclei (CPPMDN) within the wide range 255 l.e. A l.e. 314.
The predicted alpha decay half lives of $^{278}$113 and $^{282}$113 and the
alpha half lives of their decay products are in good agreement with the
experimental data. 6{\alpha) chains and 4{\alpha} chains predicted respectively
for $^{278}$113 and $^{282}$113 are in agreement with the experimental
observation. Our study shows that the isotopes in the mass range 278 l.e. A
l.e. 286 will survive fission and can be synthesized and detected in the
laboratory via alpha decay. In our study, we have predicted 6{\alpha} chains
from $^{279}$113, 4{\alpha} chains from $^{286}$113, 3{\alpha} chains from
$^{280,281,283}$113, 2{\alpha} chains from $^{284}$113 and 1{\alpha} chain from
$^{285}$113. We hope that these predictions will be a guideline for future
experimental investigations.


title: Poisson transforms for differential forms

abstract:
  We give a construction of a Poisson transform mapping density valued
differential forms on generalized flag manifolds to differential forms on the
corresponding Riemannian symmetric spaces, which can be described entirely in
terms of finite dimensional representations of reductive Lie groups. Moreover,
we will explicitly generate a family of degree-preserving Poisson transforms
whose restriction to real valued differential forms has coclosed images. In
addition, as a transform on sections of density bundles it can be related to
the classical Poisson transform, proving that we produced a natural
generalization of the classical theory.


title:
Chirality-induced helical self-propulsion of cholesteric liquid crystal
  droplets

abstract:
  We report the first experimental realization of a chiral artificial
microswimmer exhibiting the helical motion. We found that a cholesteric liquid
crystal droplet with a helical director field swims in a helical path driven by
the Marangoni flow in an aqueous surfactant solution. We confirmed that the
handedness of the droplet determines that of the helical path. This result
strongly suggests that the helical motion is originated from the chirality of
the cholesteric liquid crystal. To study the mechanism of the emergence of the
helical motion, we propose a coupled time-evolution equations in terms of a
velocity, an angular velocity and a tensor variable representing the symmetry
of the helical director field of the droplet. Our model shows that the chiral
coupling terms between the velocity and the angular velocity play a crucial
role in the emergence of the helical swimming of the droplet.


title: Stochastic Control Approach to Reputation Games

abstract:
  Through a stochastic control theoretic approach, we analyze reputation games
where a strategic long-lived player acts in a sequential repeated game against
a collection of short-lived players. The key assumption in our model is that
the information of the short-lived players is nested in that of the long-lived
player. This nested information structure is obtained through an appropriate
monitoring structure. Under this monitoring structure, we show that, given mild
assumptions, the set of Perfect Bayesian Equilibrium payoffs coincide with
Markov Perfect Equilibrium payoffs, and hence a dynamic programming formulation
can be obtained for the computation of equilibrium strategies of the strategic
long-lived player in the discounted setup. We also consider the undiscounted
average-payoff setup where we obtain an optimal equilibrium strategy of the
strategic long-lived player under further technical conditions. We then use
this optimal strategy in the undiscounted setup as a tool to obtain a tight
upper payoff bound for the arbitrarily patient long-lived player in the
discounted setup. Finally, by using measure concentration techniques, we obtain
a refined lower payoff bound on the value of reputation in the discounted
setup. We also study the continuity of equilibrium payoffs in the prior
beliefs.


title: A SAT model to mine flexible sequences in transactional datasets

abstract:
  Traditional pattern mining algorithms generally suffer from a lack of
flexibility. In this paper, we propose a SAT formulation of the problem to
successfully mine frequent flexible sequences occurring in transactional
datasets. Our SAT-based approach can easily be extended with extra constraints
to address a broad range of pattern mining applications. To demonstrate this
claim, we formulate and add several constraints, such as gap and span
constraints, to our model in order to extract more specific patterns. We also
use interactive solving to perform important derived tasks, such as closed
pattern mining or maximal pattern mining. Finally, we prove the practical
feasibility of our SAT model by running experiments on two real datasets.


title:
A strengthening of rational closure in DLs: reasoning about multiple
  aspects

abstract:
  We propose a logical analysis of the concept of typicality, central in human
cognition (Rosch,1978). We start from a previously proposed extension of the
basic Description Logic ALC (a computationally tractable fragment of First
Order Logic, used to represent concept inclusions and ontologies) with a
typicality operator T that allows to consistently represent the attribution to
classes of individuals of properties with exceptions (as in the classic example
(i) typical birds fly, (ii) penguins are birds but (iii) typical penguins don't
fly). We then strengthen this extension in order to separately reason about the
typicality with respect to different aspects (e.g., flying, having nice
feather: in the previous example, penguins may not inherit the property of
flying, for which they are exceptional, but can nonetheless inherit other
properties, such as having nice feather).


title:
Emergence of granular-sized magnetic bubbles through the solar
  atmosphere. III. The path to the transition region

abstract:
  We study the ascent of granular-sized magnetic bubbles from the solar
photosphere through the chromosphere into the transition region and above, for
the first time. Such events occurred in a flux emerging region in NOAA 11850 on
September 25, 2013. During that time, the first co-observing campaign between
the Swedish 1-m Solar Telescope and the IRIS spacecraft was carried out.
Simultaneous observations of the chromospheric H$\alpha$ 656.28 nm and
\ion{Ca}{2} 854.2 nm lines, plus the photospheric \ion{Fe}{1} 630.25 nm line,
were made with the CRISP spectropolarimeter at the SST reaching a spatial
resolution of 0."14. At the same time, IRIS was performing a four-step dense
raster of the said emerging flux region, taking slit-jaw images at 133 (C~{\sc
ii}, transition region), 140 (\ion{Si}{4}, transition region), 279.6
(\ion{Mg}{2} k, core, upper chromosphere), and 283.2 nm (\ion{Mg}{2} k, wing,
photosphere). Spectroscopy of several lines was performed by the IRIS
spectrograph in the far and near ultraviolet, of which we have used the
\ion{Si}{4} 140.3 and the \ion{Mg}{2} k 279.6 nm lines. Coronal images from the
Atmospheric Imaging Assembly of the Solar Dynamics Observatory were used to
investigate the possible coronal signatures of the flux emergence events. The
photospheric and chromospheric properties of small-scale emerging magnetic
bubbles have been described in detail in Ortiz et al. (2014). Here we are able
to follow such structures up to the transition region. We describe the
properties, including temporal delays, of the observed flux emergence in all
layers. We believe this may be an important mechanism of transporting energy
and magnetic flux from subsurface layers to the transition region and corona.


title: Mode stability of self-similar wave maps in higher dimensions

abstract:
  We consider co-rotational wave maps from Minkowski space in $d+1$ dimensions
to the $d$-sphere. Recently, Bizo\'n and Biernat found explicit self-similar
solutions for each dimension $d\geq 4$. We give a rigorous proof for the mode
stability of these self-similar wave maps.


title: Rivulet flow over a flexible beam

abstract:
  We study theoretically and experimentally how a thin layer of liquid flows
along a flexible beam. The flow is modelled using lubrication theory and the
substrate is modelled as an elastica which deforms according to the
Euler-Bernoulli equation. A constant flux of liquid is supplied at one end of
the beam, which is clamped horizontally, while the other end of the beam is
free. As the liquid film spreads, its weight causes the beam deflection to
increase, which in turn enhances the spreading rate of the liquid. This
feedback mechanism causes the front position ${\sigma}$(t) and the deflection
angle at the front ${\phi}$(t) to go through a number of different power-law
behaviours. For early times, the liquid spreads like a horizontal gravity
current, with ${\sigma}$(t) = $t^{4/5}$ and ${\phi}$(t) = $t^{13/5}$. For
intermediate times, the deflection of the beam leads to rapid acceleration of
the liquid layer, with ${\sigma}$(t) = $t^4$ and ${\phi}$(t) = $t^9$. Finally,
when the beam has sagged to become almost vertical, the liquid film flows
downward with ${\sigma}$(t) = $t$ and ${\phi}$(t) ~ ${\pi}$/2. We demonstrate
good agreement between these theoretical predictions and experimental results.


title: The end of WHAT nucleon-spin crisis?

abstract:
  Povh and Walcher have written a paper entitled "The end of the nucleon-spin
crisis" [arXiv:1603.05884]. But there is no such crisis. What appeared to be a
spin crisis in the parton model, 28 years ago, was a consequence of a
misinterpretation of the results of the famous European Muon Collaboration
experiment on polarized deep inelastic scattering. It would thus seem that Povh
and Walcher have invoked a somewhat dubious argument based on hadronic
fluctuations of the photon in order to resolve a non-existent problem.


title:
Parameter recovery in two-component contamination mixtures: the
  $\mathbb{L}^2$ strategy

abstract:
  In this paper, we consider a parametric density contamination model. We work
with a sample of i.i.d. data with a common density, $f^\star =(1-\lambda^\star)
\phi + \lambda^\star \phi(.-\mu^\star)$, where the shape $\phi$ is assumed to
be known. We establish the optimal rates of convergence for the estimation of
the mixture parameters $(\lambda^\star,\mu^\star)$. In particular, we prove
that the classical parametric rate $1/\sqrt{n}$ cannot be reached when at least
one of these parameters is allowed to tend to $0$ with $n$.


title: Double quadrics with large automorphism groups

abstract:
  We classify three-dimensional nodal Fano varieties that are double covers of
smooth quadrics branched over intersections with quartics acted on by finite
simple non-abelian groups, and study their rationality.


title: The two-dimensional density of Bernoulli Convolutions

abstract:
  Bernoulli convolutions form a one-parameter family of self-similar measures
on the unit interval. We suggest to study their two-dimensional density which
has an intricate combinatorial structure. Visualizing this structure we discuss
results of Erd\"os, J\'oo, Komornik, Sidorov, de Vries, Jordan, Shmerkin and
Solomyak, Feng and Wang. We emphasize the r\^ole of finite orbits of associated
multivalued maps and mention a few new properties and examples.


title:
MUSE 3D Spectroscopy and Kinematics of the gigahertz peaked spectrum
  Radio Galaxy PKS 1934-63: Interaction, Recently Triggered AGN and Star
  Formation

abstract:
  We observe the radio galaxy PKS 1934-63 (at $z=0.1825$) using MUSE (Multi
Unit Spectroscopic Explorer) on the Very Large Telescope (VLT). The radio
source is GigaHertz Peaked Spectrum and compact (0.13 kpc), implying an early
stage of evolution ($\leq 10^4$ yr). Our data show an interacting pair of
galaxies, projected separation 9.1 kpc, velocity difference $\Delta(v)=216$ km
$\rm s^{-1}$. The larger galaxy is a $\rm M_{*}\simeq 10^{11}M_{\odot}$
spheroidal with the emission-line spectrum of a high-excitation young radio
AGN, e.g. strong [OI]6300 and [OIII]5007. Emission-line ratios indicate a large
contribution to the line luminosity from high-velocity shocks ($\simeq 550$ km
$\rm s^{-1}$) . The companion is a non-AGN disk galaxy, with extended $\rm
H\alpha$ emission from which its star-formation rate is estimated as $\rm
0.61~M_{\odot}yr^{-1}$.
  Both galaxies show rotational velocity gradients in $\rm H\alpha$ and other
lines, with the interaction being prograde-prograde. The SE-NW velocity
gradient of the AGN host is misaligned from the E-W radio axis, but aligned
with a previously discovered central ultraviolet source, and a factor 2 greater
in amplitude in $\rm H\alpha$ than in other (forbidden) lines (e.g.
[OIII]5007). This could be produced by a fast rotating (100-150 km $\rm
s^{-1}$) disk with circumnuclear star-formation. We also identify a broad
component of [OIII]5007 emission, blueshifted with a velocity gradient aligned
with the radio jets, and associated with outflow. However, the broad component
of [OI]6300 is redshifted. In spectral fits, both galaxies have old stellar
populations plus $\sim 0.1\%$ of very young stars, consistent with the galaxies
undergoing first perigalacticon, triggering infall and star-formation from
$\sim 40$ Myr ago followed by the radio outburst.


title: Iterative Packing for Demand and Hypergraph Matching

abstract:
  Iterative rounding has enjoyed tremendous success in elegantly resolving open
questions regarding the approximability of problems dominated by covering
constraints. Although iterative rounding methods have been applied to packing
problems, no single method has emerged that matches the effectiveness and
simplicity afforded by the covering case. We offer a simple iterative packing
technique that retains features of Jain's seminal approach, including the
property that the magnitude of the fractional value of the element rounded
during each iteration has a direct impact on the approximation guarantee. We
apply iterative packing to generalized matching problems including demand
matching and $k$-column-sparse column-restricted packing ($k$-CS-PIP) and
obtain approximation algorithms that essentially settle the integrality gap for
these problems. We present a simple deterministic $2k$-approximation for
$k$-CS-PIP, where an $8k$-approximation was the best deterministic algorithm
previously known. The integrality gap in this case is at least $2(k-1+1/k)$. We
also give a deterministic $3$-approximation for a generalization of demand
matching, settling its natural integrality gap.


title: On the hyperbolicity of general hypersurfaces

abstract:
  In 1970, Kobayashi conjectured that general hypersurfaces of sufficiently
large degree in $P^n$ are hyperbolic. In this paper we prove that a general
sufficiently ample hypersurface in a smooth projective variety is hyperbolic.
To prove this statement, we construct hypersurfaces satisfying a property which
is Zariski open and which implies hyperbolicity. These hypersurfaces are chosen
such that the geometry of their higher order jet spaces can be related to the
geometry of a universal family of complete intersections. To do so, we
introduce a Wronskian construction which associates a (twisted) jet
differential to every finite family of global sections of a line bundle.


title:
Automated Alertness and Emotion Detection for Empathic Feedback During
  E-Learning

abstract:
  In the context of education technology, empathic interaction with the user
and feedback by the learning system using multiple inputs such as video, voice
and text inputs is an important area of research. In this paper, a
nonintrusive, standalone model for intelligent assessment of alertness and
emotional state as well as generation of appropriate feedback has been
proposed. Using the non-intrusive visual cues, the system classifies emotion
and alertness state of the user, and provides appropriate feedback according to
the detected cognitive state using facial expressions, ocular parameters,
postures, and gestures. Assessment of alertness level using ocular parameters
such as PERCLOS and saccadic parameters, emotional state from facial expression
analysis, and detection of both relevant cognitive and emotional states from
upper body gestures and postures has been proposed. Integration of such a
system in e-learning environment is expected to enhance students performance
through interaction, feedback, and positive mood induction.


title:
Assessing the significance of fidelity as a figure of merit in quantum
  state reconstruction of discrete and continuous variable systems

abstract:
  We experimentally address the significance of fidelity as a figure of merit
in quantum state reconstruction of discrete (DV) and continuous variable (CV)
quantum optical systems. In particular, we analyze the use of fidelity in
quantum homodyne tomography of CV states and maximum-likelihood polarization
tomography of DV ones, focussing attention on nonclassicality, entanglement and
quantum discord as a function of fidelity to a target state. Our findings show
that high values of fidelity, despite well quantifying geometrical proximity in
the Hilbert space, may be obtained for states displaying opposite physical
properties, e.g. quantum or semiclassical features. In particular, we analyze
in details the quantum-to-classical transition for squeezed thermal states of a
single-mode optical system and for Werner states of a two-photon polarization
qubit system.


title: On choosing mixture components via non-local priors

abstract:
  Choosing the number of mixture components remains an elusive challenge. Model
selection criteria can be either overly liberal or conservative and return
poorly-separated components of limited practical use. We formalize non-local
priors (NLPs) for mixtures and show how they lead to well-separated components
with non-negligible weight, interpretable as distinct subpopulations. We also
propose an estimator for posterior model probabilities under local and
non-local priors, showing that Bayes factors are ratios of posterior to prior
empty-cluster probabilities. The estimator is widely applicable and helps set
thresholds to drop unoccupied components in overfitted mixtures. We suggest
default prior parameters based on multi-modality for Normal/T mixtures and
minimal informativeness for categorical outcomes. We characterise theoretically
the NLP-induced sparsity, derive tractable expressions and algorithms. We fully
develop Normal, Binomial and product Binomial mixtures but the theory,
computation and principles hold more generally. We observed a serious lack of
sensitivity of the Bayesian information criterion (BIC), insufficient parsimony
of the AIC and a local prior, and a mixed behavior of the singular BIC. We also
considered overfitted mixtures, their performance was competitive but depended
on tuning parameters. Under our default prior elicitation NLPs offered a good
compromise between sparsity and power to detect meaningfully-separated
components.


title: Lattice Gauge Theories and Spin Models

abstract:
  The Wegner $Z_2$ gauge theory-$Z_2$ Ising spin model duality in $(2+1)$
dimensions is revisited and derived through a series of canonical
transformations. The Kramers-Wannier duality is similarly obtained. The Wegner
$Z_2$ gauge-spin duality is directly generalized to SU(N) lattice gauge theory
in $(2+1)$ dimensions to obtain the SU(N) spin model in terms of the SU(N)
magnetic fields and their conjugate SU(N) electric scalar potentials. The exact
and complete solutions of the $Z_2, U(1), SU(N)$ Gauss law constraints in terms
of the corresponding spin or dual potential operators are given. The gauge-spin
duality naturally leads to a new gauge invariant magnetic disorder operator for
SU(N) lattice gauge theory which produces a magnetic vortex on the plaquette. A
variational ground state of the SU(2) spin model with nearest neighbor
interactions is constructed to analyze SU(2) gauge theory.


title: Dissection of a rectangle into rectangles with given side ratios

abstract:
  Given a collection of N rectangles such that the side ratio of each one is a
quadratic irrationality, we find all rectangles which can be tiled by
rectangles similar to one of the given ones. It means that each possible shape
can be used several times or not used at all, so that the number of rectangles
in the tiling is not necessarily equal to N.


title:
A Semisupervised Approach for Language Identification based on Ladder
  Networks

abstract:
  In this study we address the problem of training a neuralnetwork for language
identification using both labeled and unlabeled speech samples in the form of
i-vectors. We propose a neural network architecture that can also handle
out-of-set languages. We utilize a modified version of the recently proposed
Ladder Network semisupervised training procedure that optimizes the
reconstruction costs of a stack of denoising autoencoders. We show that this
approach can be successfully applied to the case where the training dataset is
composed of both labeled and unlabeled acoustic data. The results show enhanced
language identification on the NIST 2015 language identification dataset.


title: The microphysics of collisionless shock waves

abstract:
  Collisionless shocks, that is shocks mediated by electromagnetic processes,
are customary in space physics and in astrophysics. They are to be found in a
great variety of objects and environments: magnetospheric and heliospheric
shocks, supernova remnants, pulsar winds and their nebul\ae, active galactic
nuclei, gamma-ray bursts and clusters of galaxies shock waves. Collisionless
shock microphysics enters at different stages of shock formation, shock
dynamics and particle energization and/or acceleration. It turns out that the
shock phenomenon is a multi-scale non-linear problem in time and space. It is
complexified by the impact due to high-energy cosmic rays in astrophysical
environments. This review adresses the physics of shock formation, shock
dynamics and particle acceleration based on a close examination of available
multi-wavelength or in-situ observations, analytical and numerical
developments. A particular emphasize is made on the different instabilities
triggered during the shock formation and in association with particle
acceleration processes with regards to the properties of the background
upstream medium. It appears that among the most important parameters the
background magnetic field through the magnetization and its obliquity is the
dominant one. The shock velocity that can reach relativistic speeds has also a
strong impact over the development of the micro-instabilities and the fate of
particle acceleration. Recent developments of laboratory shock experiments has
started to bring some new insights in the physics of space plasma and
astrophysical shock waves. A special section is dedicated to new laser plasma
experiments probing shock physics


title: Benchmarking Adiabatic Quantum Optimization for Complex Network Analysis

abstract:
  We lay the foundation for a benchmarking methodology for assessing current
and future quantum computers. We pose and begin addressing fundamental
questions about how to fairly compare computational devices at vastly different
stages of technological maturity. We critically evaluate and offer our own
contributions to current quantum benchmarking efforts, in particular those
involving adiabatic quantum computation and the Adiabatic Quantum Optimizers
produced by D-Wave Systems, Inc. We find that the performance of D-Wave's
Adiabatic Quantum Optimizers scales roughly on par with classical approaches
for some hard combinatorial optimization problems; however, architectural
limitations of D-Wave devices present a significant hurdle in evaluating
real-world applications. In addition to identifying and isolating such
limitations, we develop algorithmic tools for circumventing these limitations
on future D-Wave devices, assuming they continue to grow and mature at an
exponential rate for the next several years.


title: AuDroid: Preventing Attacks on Audio Channels in Mobile Devices

abstract:
  Voice control is a popular way to operate mobile devices, enabling users to
communicate requests to their devices. However, adversaries can leverage voice
control to trick mobile devices into executing commands to leak secrets or to
modify critical information. Contemporary mobile operating systems fail to
prevent such attacks because they do not control access to the speaker at all
and fail to control when untrusted apps may use the microphone, enabling
authorized apps to create exploitable communication channels. In this paper, we
propose a security mechanism that tracks the creation of audio communication
channels explicitly and controls the information flows over these channels to
prevent several types of attacks.We design and implement AuDroid, an extension
to the SELinux reference monitor integrated into the Android operating system
for enforcing lattice security policies over the dynamically changing use of
system audio resources. To enhance flexibility, when information flow errors
are detected, the device owner, system apps and services are given the
opportunity to resolve information flow errors using known methods, enabling
AuDroid to run many configurations safely. We evaluate our approach on 17
widely-used apps that make extensive use of the microphone and speaker, finding
that AuDroid prevents six types of attack scenarios on audio channels while
permitting all 17 apps to run effectively. AuDroid shows that it is possible to
prevent attacks using audio channels without compromising functionality or
introducing significant performance overhead.


title: Investigating Bias in Maximum Likelihood Quantum State Tomography

abstract:
  Maximum likelihood quantum state tomography yields estimators that are
consistent, provided that the likelihood model is correct, but the maximum
likelihood estimators may have bias for any finite data set. The bias of an
estimator is the difference between the expected value of the estimate and the
true value of the parameter being estimated. This paper investigates bias in
the widely used maximum likelihood quantum state tomography. Our goal is to
understand how the amount of bias depends on factors such as the purity of the
true state, the number of measurements performed, and the number of different
bases in which the system is measured. For that, we perform numerical
experiments that simulate optical homodyne tomography under various conditions,
perform tomography, and estimate bias in the purity of the estimated state. We
find that estimates of higher purity states exhibit considerable bias, such
that the estimates have lower purity than the true states.


title: Generalized Hypergraph Matching via Iterated Packing and Local Ratio

abstract:
  In $k$-hypergraph matching, we are given a collection of sets of size at most
$k$, each with an associated weight, and we seek a maximum-weight subcollection
whose sets are pairwise disjoint. More generally, in $k$-hypergraph
$b$-matching, instead of disjointness we require that every element appears in
at most $b$ sets of the subcollection. Our main result is a linear-programming
based $(k-1+\tfrac{1}{k})$-approximation algorithm for $k$-hypergraph
$b$-matching. This settles the integrality gap when $k$ is one more than a
prime power, since it matches a previously-known lower bound. When the
hypergraph is bipartite, we are able to improve the approximation ratio to
$k-1$, which is also best possible relative to the natural LP. These results
are obtained using a more careful application of the \emph{iterated packing}
method.
  Using the bipartite algorithmic integrality gap upper bound, we show that for
the family of combinatorial auctions in which anyone can win at most $t$ items,
there is a truthful-in-expectation polynomial-time auction that
$t$-approximately maximizes social welfare. We also show that our results
directly imply new approximations for a generalization of the recently
introduced bounded-color matching problem.
  We also consider the generalization of $b$-matching to \emph{demand
matching}, where edges have nonuniform demand values. The best known
approximation algorithm for this problem has ratio $2k$ on $k$-hypergraphs. We
give a new algorithm, based on local ratio, that obtains the same approximation
ratio in a much simpler way.


title: First detection of gas-phase ammonia in a planet-forming disk

abstract:
  Nitrogen chemistry in protoplanetary disks and the freeze-out on dust
particles is key to understand the formation of nitrogen bearing species in
early solar system analogs. So far, ammonia has not been detected beyond the
snowline in protoplanetary disks. We aim to find gas-phase ammonia in a
protoplanetary disk and characterize its abundance with respect to water vapor.
Using HIFI on the Herschel Space Observatory we detect, for the first time, the
ground-state rotational emission of ortho-NH$_3$ in a protoplanetary disk,
around TW Hya. We use detailed models of the disk's physical structure and the
chemistry of ammonia and water to infer the amounts of gas-phase molecules of
these species. We explore two radial distributions ( confined to $<$60 au like
the millimeter-sized grains) and two vertical distributions (near the midplane
where water is expected to photodesorb off icy grains) to describe the
(unknown) location of the molecules. These distributions capture the effects of
radial drift and vertical settling of ice-covered grains. We use
physical-chemical models to reproduce the fluxes with assuming that water and
ammonia are co-spatial. We infer ammonia gas-phase masses of 0.7-11.0
$\times$10$^{21}$ g. For water, we infer gas-phase masses of 0.2-16.0
$\times$10$^{22}$ g. This corresponds to NH$_3$/H$_2$O abundance ratios of
7\%-84\%, assuming that water and ammonia are co-located. Only in the most
compact and settled adopted configuration is the inferred NH$_3$/H$_2$O
consistent with interstellar ices and solar system bodies of $\sim$ 5\%-10\%.
Volatile release in the midplane may occur via collisions between icy bodies if
the available surface for subsequent freeze-out is significantly reduced, e.g.,
through growth of small grains into pebbles or larger.


title: Type I/heterotic duality and M-theory amplitudes

abstract:
  This paper investigates relationships between low-energy four-particle
scattering amplitudes with external gauge particles and gravitons in the E_8 X
E_8 and SO(32) heterotic string theories and the type I and type IA superstring
theories by considering a variety of tree level and one-loop Feynman diagrams
describing such amplitudes in eleven-dimensional supergravity in a
Horava--Witten background compactified on a circle. This accounts for a number
of perturbative and non-perturbative aspects of low order higher derivative
terms in the low-energy expansion of string theory amplitudes, which are
expected to be protected by half maximal supersymmetry from receiving
corrections beyond one or two loops. It also suggests the manner in which type
I/heterotic duality may be realised for certain higher derivative interactions
that are not so obviously protected. For example, our considerations suggest
that R**4 interactions (where R is the Riemann curvature) might receive no
perturbative corrections beyond one loop by virtue of a conspiracy involving
contributions from (non-BPS) Z2 D-instantons in the type I and heterotic SO(32)
theories.


title: Elementary quantum gates in different bases

abstract:
  We introduce transformation matrix connecting sets of the displaced states
with different displacement amplitudes. Arbitrary pure one-mode state can be
represented in new basis of the displaced number (Fock) states (
representation) by multiplying the transposed transformation matrix on a column
vector of initial state. Analytical expressions of the representation of
superposition of vacuum and single photon and two-mode squeezed vacuum (TMSV)
are obtained. On the basis of the developed mathematical formalism, we consider
the mechanism of interaction between qubits which is based on their displaced
properties. Superposed coherent states deterministically displace target state
on equal modulo but opposite on sign values. Registration of the single photon
in auxiliary mode (probabilistic operation) results in constructive
interference and gives birth to entangled hybrid state corresponding to outcome
of elementary quantum gates. The method requires minimal number of resource and
works in realistic scenario


title:
How to Transfer? Zero-Shot Object Recognition via Hierarchical Transfer
  of Semantic Attributes

abstract:
  Attribute based knowledge transfer has proven very successful in visual
object analysis and learning previously unseen classes. However, the common
approach learns and transfers attributes without taking into consideration the
embedded structure between the categories in the source set. Such information
provides important cues on the intra-attribute variations. We propose to
capture these variations in a hierarchical model that expands the knowledge
source with additional abstraction levels of attributes. We also provide a
novel transfer approach that can choose the appropriate attributes to be shared
with an unseen class. We evaluate our approach on three public datasets:
aPascal, Animals with Attributes and CUB-200-2011 Birds. The experiments
demonstrate the effectiveness of our model with significant improvement over
state-of-the-art.


title:
Simulations of coherent nonlinear optical response of molecular vibronic
  dimers

abstract:
  We have implemented vibronic dynamics for simulations of the third order
coherent response of electronic dimers. In the present communication we provide
the full and detailed description of the dynamical model, recently used for
simulations of chlorophyll-carotenoid dyads, terylene dimers, or hypericin. We
allow for explicit vibronic level structure, by including selected vibrational
modes into a "system". Bath dynamics include the Landau-Teller vibrational
relaxation, electronic dephasing, and nonlinear vibronic (to bath) coupling.
Simulations combine effects of transport and dephasing between vibronic levels.
Transport is described by master equation within secular approximation, phase
is accumulated in cumulants and its calculation follows the transport pathways
during waiting time period.


title:
Elastic and Piezoresistive Properties of Nickel Carbides from
  First-Principles

abstract:
  The nickel--carbon system has received increased attention over the past
years due to the relevance of nickel as a catalyst for carbon nanotube and
graphene growth, where Nickel carbide intermediates may be involved or carbide
interface layers form in the end. Nickel--carbon composite thin films
comprising Ni$_3$C are especially interesting in mechanical sensing
applications. Due to the meta-stability of nickel carbides, formation
conditions and the coupling between mechanical and electrical properties are
not yet well understood. Using first-principles electronic structure methods,
we calculated the elastic properties of Ni$_3$C, Ni$_2$C and NiC, as well as
changes in electronic properties under mechanical strain. We observe that the
electronic density of states around the Fermi level does not change under the
considered strains of up to 1%, which correspond to stresses up to 3GPa.
Relative changes in conductivity of Ni$_3$C range up to maximum values of about
10%.


title:
Unified entropic measures of quantum correlations induced by local
  measurements

abstract:
  We introduce quantum correlations measures based on the minimal change in
unified entropies induced by local rank-one projective measurements, divided by
a factor that depends on the generalized purity of the system in the case of
non-additive entropies. In this way, we overcome the issue of the artificial
increasing of the value of quantum correlations measures based on non-additive
entropies when an uncorrelated ancilla is appended to the system without
changing the computability of our entropic correlations measures with respect
to the previous ones. Moreover, we recover as limiting cases the quantum
correlations measures based on von Neumann and R\'enyi entropies (i.e.,
additive entropies), for which the adjustment factor becomes trivial. In
addition, we distinguish between total and semiquantum correlations and obtain
some relations between them. Finally, we obtain analytical expressions of the
entropic correlations measures for typical quantum bipartite systems.


title:
Super-maximal representations from fundamental groups of punctured
  surfaces to $\mathrm{PSL}(2,\mathbb{R})$

abstract:
  We study a particular class of representations from the fundamental groups of
punctured spheres $\Sigma_{0,n}$ to the group $\text{PSL} (2,\mathbb R)$ (and
their moduli spaces), that we call \emph{super-maximal}. Super-maximal
representations are shown to be \emph{totally non hyperbolic}, in the sense
that every simple closed curve is mapped to a non hyperbolic element. They are
also shown to be \emph{geometrizable} (appart from the reducible super-maximal
ones) in the following very strong sense : for any element of the Teichm\"uller
space $\mathcal T_{0,n}$, there is a unique holomorphic equivariant map with
values in the lower half-plane $\mathbb H^-$. In the relative character
variety, the components of super-maximal representations are shown to be
compact, and symplectomorphic (with respect to the Atiyah-Bott-Goldman
symplectic structure) to the complex projective space of dimension $n-3$
equipped with a certain multiple of the Fubiny-Study form that we compute
explicitly (this generalizes a result of Benedetto--Goldman for the sphere
minus four points). Those are the unique compact components in relative
character varieties of $\text{PSL}(2,\mathbb R)$. This latter fact will be
proved in a companion paper.


title: Signatures of phase transitions in the microwave response of YbRh2Si2

abstract:
  We used a spectroscopic microwave technique utilizing superconducting
stripline resonators at frequencies between 3 GHz and 15 GHz to examine the
charge dynamics of YbRh2Si2 at temperatures and magnetic fields close to the
quantum critical point. The different electronic phases of this heavy-fermion
compound, in particular the antiferromagnetic, Fermi-liquid, and
non-Fermi-liquid regimes, were probed with temperature-dependent microwave
measurements between 40 mK and 600 mK at a set of different magnetic fields up
to 140 mT. Signatures of phase transitions were observed, which give
information about the dynamic response of this peculiar material that exhibits
field-tuned quantum criticality and pronounced deviations from Fermi-liquid
theory.


title:
Anisotropies in the gravitational wave background as a probe of the
  cosmic string network

abstract:
  Pulsar timing arrays are one of the powerful tools to test the existence of
cosmic strings through searching for the gravitational wave background. The
amplitude of the background connects to information on cosmic strings such as
the tension and string network properties. In addition, one may be able to
extract more information on properties of cosmic strings by measuring
anisotropies in the gravitational wave (GW) background. In this paper, we
provide estimates of the level of anisotropy expected in the GW background
generated by cusps on cosmic strings. We find that the anisotropy level
strongly depends on the initial loop size $\alpha$, and thus we may be able to
put constraint on $\alpha$ by measuring the anisotropy of the GW background. We
also find that certain regions of the parameter space can be probed by shifting
the observation frequency of GWs.


title: Prospects for Future Collider Physics

abstract:
  One item on the agenda of future colliders is certain to be the Higgs boson.
What is it trying to tell us? The primary objective of any future collider must
surely be to identify physics beyond the Standard Model, and supersymmetry is
one of the most studied options. it Is supersymmetry waiting for us and, if so,
can LHC Run 2 find it? The big surprise from the initial 13-TeV LHC data has
been the appearance of a possible signal for a new boson X with a mass ~750
GeV. What are the prospects for future colliders if the X(750) exists? One of
the most intriguing possibilities in electroweak physics would be the discovery
of non-perturbative phenomena. What are the prospects for observing sphalerons
at the LHC or a future collider?


title:
Closed expression for the pair vibrational correlation energy of a
  uniform distribution of single-nucleon levels

abstract:
  A closed expression is derived for the pair vibrational correlation energy
generated in the random phase approximation by the isovector pairing force in
the case when Kramers and charge degenerate single-nucleon levels are uniformly
distributed in an interval. The expression is used to analyze the spectral
density of pair vibrational frequencies relative to that of two-quasinucleon
energies. Applications to the analysis of the symmetry energy of the isovector
pairing model and to a Strutinskij renormalization of this model are discussed.


title: Initial State Quantum Fluctuations in the Little Bang

abstract:
  We review recent developments in the ab-initio theoretical description of the
initial state in heavy-ion collisions. We emphasize the importance of
fluctuations, both for the phenomenological description of experimental data
from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider
(LHC), and the theoretical understanding of the non-equilibrium early time
dynamics and thermalization of the medium.


title:
Simultaneous rheo-electric measurements of strongly conductive complex
  fluids

abstract:
  We introduce a novel apparatus designed for stress-controlled rheometers to
perform simultaneous rheological and electrical measurements on strongly
conductive complex fluids under shear. By means of a non-toxic liquid metal at
room temperature, the electrical connection to the rotating shaft is completed
with minimal additional mechanical friction, allowing for simultaneous stress
measurements as low as 1 Pa. We use the capabilities of this design to perform
an extensive set of rheo-electric experiments on gels formulated from
attractive carbon black particles, at concentrations ranging from 4 to 15% wt.
First, experiments on gels at rest prepared with different shear history show a
robust power-law scaling between the elastic modulus $G'_0$ and the
conductivity $\sigma_0$ of the gels, i.e. $G'_0 \sim \sigma_0^\alpha$, with
$\alpha =1.65 \pm 0.04$ independently of the gel concentration. Second,
conductivity measurements performed simultaneously with creep experiments
reveal for the first time that plastic events take place in the bulk while the
shear rate decreases as a weak power law of time in the early stage of the
experiment. The subsequent evolution of the conductivity and shear rate allows
us to propose a local yielding scenario that is in agreement with previous
velocimetry measurements. Finally, we determine the constitutive rheological
and electrical behavior of carbon black gels. Corrections first introduced for
mechanical measurements are carefully extended to electrical measurements to
accurately distinguish between bulk and surface contributions to the
conductivity. As an illustrative example, we examine the constitutive
rheo-electric properties of five carbon black gels of different grades, and
demonstrate the relevance of the novel rheo-electric apparatus as a versatile
characterization tool for strongly conductive complex fluids and their
applications.


title: Understanding and Controlling Water Stability of MOF-74

abstract:
  Metal organic framework (MOF) materials in general, and MOF-74 in particular,
have promising properties for many technologically important processes.
However, their instability under humid conditions severely restricts practical
use. We show that this instability and the accompanying reduction of the CO$_2$
uptake capacity of MOF-74 under humid conditions originate in the water
dissociation reaction H$_2$O$\rightarrow$OH+H at the metal centers. After this
dissociation, the OH groups coordinate to the metal centers, explaining the
reduction in the MOF's CO$_2$ uptake capacity. This reduction thus strongly
depends on the catalytic activity of MOF-74 towards the water dissociation
reaction. We further show that-while the water molecules themselves only have a
negligible effect on the crystal structure of MOF-74-the OH and H products of
the dissociation reaction significantly weaken the MOF framework and lead to
the observed crystal structure breakdown. With this knowledge, we propose a way
to suppress this particular reaction by modifying the MOF-74 structure to
increase the water dissociation energy barrier and thus control the stability
of the system under humid conditions.


title: On universal quadratic identities for minors of quantum matrices

abstract:
  We give a complete combinatorial characterization of homogeneous quadratic
relations of "universal character" valid for minors of quantum matrices (more
precisely, for minors in the quantized coordinate ring $O_q(M_{m,n}(K))$ of
$m\times n$ matrices over a field $K$, where $q\in K^\ast$). This is obtained
as a consequence of a study of quantized minors of matrices generated by paths
in certain planar graphs, called SE-graphs, generalizing the ones associated
with Cauchon diagrams. Our efficient method of verifying universal quadratic
identities for minors of quantum matrices is illustrated with many appealing
examples.


title:
First-principles study of organically modified muscovite mica with
  ammonium (NH$_4^+$) or methylammonium (CH$_3$NH$_3^+$) ion

abstract:
  Using density functional theory calculations, we have investigated the
interlayer cation exchange phenomena in muscovite mica, which is motivated by a
necessity to develop flexible high-insulating covering materials. The
crystalline structures, chemical bonding properties, energetics, and electronic
properties of muscovites before and after exchange of interlayer K$^+$ cation
with ammonium (NH$_4^+$) or methylammonium (CH$_3$NH$_3^+$) ion were
calculated. It was found that the unit cell volume changes are negligibly small
upon exchange with NH$_4^+$ ion, while the unit cells are expanded with about 4
\% relative rate when replacing the interlayer K$^+$ cation with CH$_3$NH$_3^+$
ion. The energy band gap of pre-exchanged muscovite was calculated to be about
5 eV, which hardly changes upon interlayer cation exchange with either NH$_4^+$
or CH$_3$NH$_3^+$ ion, indicating the preservation of high insulating property
of muscovite. The exchange energies were found to be about -100 kJ/mol for
NH$_4^+$ and about -50 kJ/mol for CH$_3$NH$_3^+$ exchange, indicating that the
exchange reactions are exothermic. A detailed analysis of atomic resolved
density of states and electron density redistribution was provided.


title: Simple model for Crystal Field Theory

abstract:
  We investigate a simple model for the prediction of the splitting of the $3d$
orbitals of a metal ion in the environment of ligands. The electrons are
considered to be independent and their interaction with the ligands is
represented by the Dirac delta function in three dimensions. We discuss several
cases where the model is successful and a few ones where it is not.


title: Construction of right gyrogroup structures on a non-abelian group

abstract:
  In this article we gave the notion of particular type of functions on a group
termed as class assigned functions . Using class assigned functions, we have
constructed several right gyrogroup structures on a given non-abelian group.


title:
A Proposed Experimental Search for Chameleons using Asymmetric Parallel
  Plates

abstract:
  Light scalar fields coupled to matter are a common consequence of theories of
dark energy and attempts to solve the cosmological constant problem. The
chameleon screening mechanism is commonly invoked in order to suppress the
fifth forces mediated by these scalars, suficiently to avoid current
experimental constraints, without fine tuning. The force is suppressed
dynamically by allowing the mass of the scalar to vary with the local density.
Recently it has been shown that near future cold atoms experiments using
atom-interferometry have the ability to access a large proportion of the
chameleon parameter space. In this work we demonstrate how experiments
utilising asymmetric parallel plates can push deeper into the remaining
parameter space available to the chameleon.


title: Correlation plenoptic imaging

abstract:
  Plenoptic imaging is a promising optical modality that simultaneously
captures the location and the propagation direction of light in order to enable
three-dimensional imaging in a single shot. However, in classical imaging
systems, the maximum spatial and angular resolutions are fundamentally linked;
thereby, the maximum achievable depth of field is inversely proportional to the
spatial resolution. We propose to take advantage of the second-order
correlation properties of light to overcome this fundamental limitation. In
this paper, we demonstrate that the momentum/position correlation of chaotic
light leads to the enhanced refocusing power of correlation plenoptic imaging
with respect to standard plenoptic imaging.


title: Influence of plasma turbulence on microwave propagation

abstract:
  It is not fully understood how electromagnetic waves propagate through plasma
density fluctuations when the size of the fluctuations is comparable with the
wavelength of the incident radiation. In this paper, the perturbing effect of a
turbulent plasma density layer on a traversing microwave beam is simulated with
full-wave simulations. The deterioration of the microwave beam is calculated as
a function of the characteristic turbulence structure size, the turbulence
amplitude, the depth of the interaction zone and the size of the waist of the
incident beam. The maximum scattering is observed for a structure size on the
order of half the vacuum wavelength. The scattering and beam broadening was
found to increase linearly with the depth of the turbulence layer and
quadratically with the fluctuation strength. Consequences for experiments and
3D effects are considered.


title:
Auxiliary-field based trial wave functions in quantum Monte Carlo
  calculations

abstract:
  Quantum Monte Carlo (QMC) algorithms have long relied on Jastrow factors to
incorporate dynamic correlation into trial wave functions. While Jastrow-type
wave functions have been widely employed in real-space algorithms, they have
seen limited use in second-quantized QMC methods, particularly in projection
methods that involve a stochastic evolution of the wave function in imaginary
time. Here we propose a scheme for generating Jastrow-type correlated trial
wave functions for auxiliary-field QMC methods. The method is based on
decoupling the two-body Jastrow into one-body projectors coupled to auxiliary
fields, which then operate on a single determinant to produce a
multi-determinant trial wave function. We demonstrate that intelligent sampling
of the most significant determinants in this expansion can produce compact
trial wave functions that reduce errors in the calculated energies. Our
technique may be readily generalized to accommodate a wide range of two-body
Jastrow factors and applied to a variety of model and chemical systems.


title: Refactoring Delta-Oriented Product Lines to achieve Monotonicity

abstract:
  Delta-oriented programming (DOP) is a flexible transformational approach to
implement software product lines. In delta-oriented product lines, variants are
generated by applying operations contained in delta modules to a (possibly
empty) base program. These operations can add, remove or modify named elements
in a program (e.g., classes, methods and fields in a Java program). This paper
presents algorithms for refactoring a delta-oriented product line into
monotonic form, i.e., either to contain add and modify operations only
(monotonic increasing) or to contain remove and modify operations only
(monotonic decreasing). Because of their simpler structure, monotonic
delta-oriented product lines are easier to analyze. The algorithms are
formalized by means of a core calculus for DOP of product lines of Java
programs and their correctness and complexity are given.


title:
Conflict Detection for Edits on Extended Feature Models using Symbolic
  Graph Transformation

abstract:
  Feature models are used to specify variability of user-configurable systems
as appearing, e.g., in software product lines. Software product lines are
supposed to be long-living and, therefore, have to continuously evolve over
time to meet ever-changing requirements. Evolution imposes changes to feature
models in terms of edit operations. Ensuring consistency of concurrent edits
requires appropriate conflict detection techniques. However, recent approaches
fail to handle crucial subtleties of extended feature models, namely
constraints mixing feature-tree patterns with first-order logic formulas over
non-Boolean feature attributes with potentially infinite value domains. In this
paper, we propose a novel conflict detection approach based on symbolic graph
transformation to facilitate concurrent edits on extended feature models. We
describe extended feature models formally with symbolic graphs and edit
operations with symbolic graph transformation rules combining graph patterns
with first-order logic formulas. The approach is implemented by combining
eMoflon with an SMT solver, and evaluated with respect to applicability.


title:
Incremental Consistency Checking in Delta-oriented UML-Models for
  Automation Systems

abstract:
  Automation systems exist in many variants and may evolve over time in order
to deal with different environment contexts or to fulfill changing customer
requirements. This induces an increased complexity during design-time as well
as tedious maintenance efforts. We already proposed a multi-perspective
modeling approach to improve the development of such systems. It operates on
different levels of abstraction by using well-known UML-models with activity,
composite structure and state chart models. Each perspective was enriched with
delta modeling to manage variability and evolution. As an extension, we now
focus on the development of an efficient consistency checking method at several
levels to ensure valid variants of the automation system. Consistency checking
must be provided for each perspective in isolation, in-between the perspectives
as well as after the application of a delta.


title: Analysis of Feature Models Using Alloy: A Survey

abstract:
  Feature Models (FMs) are a mechanism to model variability among a family of
closely related software products, i.e. a software product line (SPL). Analysis
of FMs using formal methods can reveal defects in the specification such as
inconsistencies that cause the product line to have no valid products. A
popular framework used in research for FM analysis is Alloy, a light-weight
formal modeling notation equipped with an efficient model finder. Several works
in the literature have proposed different strategies to encode and analyze FMs
using Alloy. However, there is little discussion on the relative merits of each
proposal, making it difficult to select the most suitable encoding for a
specific analysis need. In this paper, we describe and compare those strategies
according to various criteria such as the expressivity of the FM notation or
the efficiency of the analysis. This survey is the first comparative study of
research targeted towards using Alloy for FM analysis. This review aims to
identify all the best practices on the use of Alloy, as a part of a framework
for the automated extraction and analysis of rich FMs from natural language
requirement specifications.


title: Towards a Feature mu-Calculus Targeting SPL Verification

abstract:
  The modal mu-calculus mu-L is a well-known fixpoint logic to express and
model check properties interpreted over labeled transition systems. In this
paper, we propose two variants of the mu-calculus, mu-Lf and mu-Lf', for
feature transition systems. For this, we explicitly incorporate feature
expressions into the logics, allowing operators to select transitions and
behavior restricted to specific products and subfamilies. We provide semantics
for mu-Lf and mu-Lf' and relate the two new mu-calculi and mu-L to each other.
Next, we focus on the analysis of SPL behavior and show how our formalism can
be applied for product-based verification with mu-Lf as well as family-based
verification with mu-Lf'. We illustrate by means of a toy example how
properties can be model checked, exploiting an embedding of mu-Lf' into the
mu-calculus with data.