title: Radial continuous valuations on star bodies and star sets

abstract:
  We show that a radial continuous valuation defined on the $n$-dimensional
star bodies extends uniquely to a continuous valuation on the $n$-dimensional
bounded star sets. Moreover, we provide an integral representation of every
such valuation, in terms of the radial function, which is valid on the dense
subset of the simple Borel star sets. We also show that every radial continuous
valuation defined on the $n$-dimensional star bodies can be decomposed as a sum
$V=V^+-V^-$, where both $V^+$ and $V^-$ are positive radial continuous
valuations.


title: On Fixing number of Functigraphs

abstract:
  The fixing number of a graph $G$ is the order of the smallest subset $S$ of
its vertex set $V(G)$ such that stabilizer of $S$ in $G$, $\Gamma_{S}(G)$ is
trivial. Let $G_{1}$ and $G_{2}$ be disjoint copies of a graph $G$, and let
$g:V(G_{1})\rightarrow V(G_{2})$ be a function. A functigraph $F_{G}$ consists
of the vertex set $V(G_{1})\cup V(G_{2})$ and the edge set $E(G_{1})\cup
E(G_{2})\cup \{uv:v=g(u)\}$. In this paper, we study the behavior of the fixing
number in passing from $G$ to $F_{G}$ and find its sharp lower and upper
bounds. We also study the fixing number of functigraphs of some well known
families of graphs like complete graphs, trees and join graphs.


title: Early Universes with Effective Discrete Time

abstract:
  The mechanism for triggering the universe inflation could be that at very
early periods the time variable was discrete instead of smooth. Alternatively,
and perhaps equivalently, it could be the consequence that the metrics of the
early universe was a strongly concentrated gravitational coherent state with
very high frequency oscillations, allowing local pair creations by a
generalisation to gravity of the Schwinger mechanism, perhaps by creation of
black holes of masses superior to the Planck scale. The lattice spacing between
two clicks in the discrete time picture corresponds to the inverse frequency of
the gravitational coherent state in the other picture. In both cases, a much
lower time than the Planck time might represent a new fundamental scale, giving
new type of physics. To make possible a concrete estimation of the pair
production probability, we propose that the oscillating coherent state metrics
that defines this very early geometry minimises the Einstein gravity action
coupled to interacting 1-,2- and 3-forms. Part of our intuition relies on a
condensed matter analogy with laser-induced superconductivity. An independent
section suggests that the new physical time scale we introduce for the
Markovian discret time of the pre-inflation epoch can be identified with the
stochastic time one uses for standard quantisation in the post-inflation limit.
In the pre-inflation phase its discreteness is the observable driving force for
the universe evolution, while in the post inflation phase it becomes
unobservable and it can can effectively replaced by the continuous time
coordinate of standard quantum field theory.


title: Stability of amplitude chimeras in oscillator networks

abstract:
  We show that amplitude chimeras in ring networks of Stuart-Landau oscillators
with symmetry-breaking nonlocal coupling represent saddle-states in the
underlying phase space of the network. Chimera states are composed of
coexisting spatial domains of coherent and of incoherent oscillations. We
calculate the Floquet exponents and the corresponding eigenvectors in
dependence upon the coupling strength and range, and discuss the implications
for the phase space structure. The existence of at least one positive real part
of the Floquet exponents indicates an unstable manifold in phase space, which
explains the nature of these states as long-living transients. Additionally, we
find a Stuart-Landau network of minimum size $N=12$ exhibiting amplitude
chimeras


title:
Topological collective plasmons in bipartite chains of metallic
  nanoparticles

abstract:
  We study a bipartite linear chain constituted by spherical metallic
nanoparticles, where each nanoparticle supports a localized surface plasmon.
The near-field dipolar interaction between the localized surface plasmons gives
rise to collective plasmons, which are extended over the whole nanoparticle
array. We derive analytically the spectrum and the eigenstates of the
collective plasmonic excitations. At the edge of the Brillouin zone, the
spectrum is of a pseudorelativistic nature similar to that present in the
electronic band structure of polyacetylene. We find the effective Dirac
Hamiltonian for the collective plasmons and show that the corresponding spinor
eigenstates represent one-dimensional Dirac-like massive bosonic excitations.
Therefore, the plasmonic lattice exhibits similar effects to those found for
electrons in one-dimensional Dirac materials, such as the ability for
transmission with highly suppressed backscattering due to Klein tunneling. We
also show that the system is governed by a nontrivial Zak phase, which predicts
the manifestation of edge states in the chain. When two dimerized chains with
different topological phases are connected, we find the appearance of the
bosonic version of a Jackiw-Rebbi midgap state. We further investigate the
radiative and nonradiative lifetimes of the collective plasmonic excitations
and comment on the challenges for experimental realization of the topological
effects found theoretically.


title: On the Impact of Entity Linking in Microblog Real-Time Filtering

abstract:
  Microblogging is a model of content sharing in which the temporal locality of
posts with respect to important events, either of foreseeable or unforeseeable
nature, makes applica- tions of real-time filtering of great practical
interest. We propose the use of Entity Linking (EL) in order to improve the
retrieval effectiveness, by enriching the representation of microblog posts and
filtering queries. EL is the process of recognizing in an unstructured text the
mention of relevant entities described in a knowledge base. EL of short pieces
of text is a difficult task, but it is also a scenario in which the information
EL adds to the text can have a substantial impact on the retrieval process. We
implement a start-of-the-art filtering method, based on the best systems from
the TREC Microblog track realtime adhoc retrieval and filtering tasks , and
extend it with a Wikipedia-based EL method. Results show that the use of EL
significantly improves over non-EL based versions of the filtering methods.


title: Exploring universality of transversity in p-p collisions

abstract:
  The transversity distribution was recently extracted from deep-inelastic
scattering processes producing hadron pairs in the final state. Together with a
specific chiral-odd di-hadron fragmentation function, it is involved in the
elementary mechanism that generates a transverse-spin asymmetry in the
azimuthal distribution of the detected hadron pairs. The same elementary
mechanism was predicted to generate an analogous asymmetry when the hadron
pairs are produced in proton-proton collisions with one transversely polarized
proton. Recently, the STAR Collaboration has observed this asymmetry. We
analyze the impact of these data on our knowledge of transversity.


title:
Error-detected generation and complete analysis of hyperentangled Bell
  states for photons assisted by quantum-dot spins in double-sided optical
  microcavities

abstract:
  We construct an error-detected block, assisted by the quantum-dot spins in
double-sided optical microcavities. With this block, we propose three
error-detected schemes for the deterministic generation, the complete analysis,
and the complete nondestructive analysis of hyperentangled Bell states in both
the polarization and spatial-mode degrees of freedom of two-photon systems. In
these schemes, the errors can be detected, which can improve their fidelities
largely, far different from other previous schemes assisted by the interaction
between the photon and the quantum-dot-cavity system. Our scheme for the
deterministic generation of hyperentangled two-photon systems can be performed
by repeat until success. These features make our schemes more useful in
high-capacity quantum communication with hyperentanglement in the future.


title: Optimization of Generalized Unary Coding

abstract:
  This paper proposes an optimum version of the recently advanced scheme for
generalized unary coding. In this method, the block of 1s that identifies the
number is allowed to be broken up, which extends the count. The result is
established by a theorem. The number count is now n(n-k-1)+1 rather than the
previously described (n-k)(n-k)-1.


title:
Exploring Non-Reversing Magic Mirrors for Screen-Based Augmented Reality
  Systems

abstract:
  Screen-based Augmented Reality (AR) systems can be built as a window into the
real world as often done in mobile AR applications or using the Magic Mirror
metaphor, where users can see themselves with augmented graphics on a large
display. Such Magic Mirror systems have been used in digital clothing
environments to create virtual dressing rooms, to teach human anatomy, and for
collaborative design tasks. The term Magic Mirror implies that the display
shows the users enantiomorph, i.e. the mirror image, such that the system
mimics a real-world physical mirror. However, the question arises whether one
should design a traditional mirror, or instead display the true mirror image by
means of a non-reversing mirror? This is an intriguing perceptual question, as
the image one observes in a mirror is not a real view, as it would be seen by
an external observer, but a reflection, i.e. a front-to-back reversed image. In
this paper, we discuss the perceptual differences between these two mirror
visualization concepts and present a first comparative study in the context of
Magic Mirror anatomy teaching. We investigate the ability of users to identify
the correct placement of virtual anatomical structures in our screen-based AR
system for two conditions: a regular mirror and a non-reversing mirror setup.
The results of our study indicate that the latter is more suitable for
applications where previously acquired domain-specific knowledge plays an
important role. The lessons learned open up new research directions in the
fields of user interfaces and interaction in non-reversing mirror environments
and could impact the implementation of general screen-based AR systems in other
domains.


title: Testing, Verification and Improvements of Timeliness in ROS processes

abstract:
  This paper addresses the problem of improving response times of robots
implemented in the Robotic Operating System (ROS) using formal verification of
computational-time feasibility. In order to verify the real time behaviour of a
robot under uncertain signal processing times, methods of formal verification
of timeliness properties are proposed for data flows in a ROS-based control
system using Probabilistic Timed Programs (PTPs). To calculate the probability
of success under certain time limits, and to demonstrate the strength of our
approach, a case study is implemented for a robotic agent in terms of
operational times verification using the PRISM model checker, which points to
possible enhancements to the operation of the robotic agent.


title: Numerically robust computation of circular visibility

abstract:
  We address the question of whether a point inside a domain bounded by a
simple closed arc spline is circularly visible from a specified arc from the
boundary. We provide a simple and numerically stable linear time algorithm that
solves this problem. In particular, we present an easy-to-check criterion that
implies that a point is not visible from a specified boundary arc.


title: Bulk and Surface Event Identification in p-type Germanium Detectors

abstract:
  The p-type point-contact germanium detectors have been adopted for light dark
matter WIMP searches and the studies of low energy neutrino physics. These
detectors exhibit anomalous behavior to events located at the surface layer.
The previous spectral shape method to identify these surface events from the
bulk signals relies on spectral shape assumptions and the use of external
calibration sources. We report an improved method in separating them by taking
the ratios among different categories of in situ event samples as calibration
sources. Data from CDEX-1 and TEXONO experiments are re-examined using the
ratio method. Results are shown to be consistent with the spectral shape
method.


title: Evaluation of spatial trees for simulation of biological tissue

abstract:
  Spatial organization is a core challenge for all large agent-based models
with local interactions. In biological tissue models, spatial search and
reinsertion are frequently reported as the most expensive steps of the
simulation. One of the main methods utilized in order to maintain both
favorable algorithmic complexity and accuracy is spatial hierarchies. In this
paper, we seek to clarify to which extent the choice of spatial tree affects
performance, and also to identify which spatial tree families are optimal for
such scenarios. We make use of a prototype of the new BioDynaMo tissue
simulator for evaluating performances as well as for the implementation of the
characteristics of several different trees.


title: Formation of hypernuclei in evaporation and fission processes

abstract:
  There are excellent opportunities to produce excited heavy hyper residues in
relativistic hadron and peripheral heavy-ion collisions. We investigate the
disintegration of such residues into hyper nuclei via evaporation of baryons
and light clusters and their fission. Previously these processes were well
known for normal nuclei as the decay channels at low excitation energies. We
have generalized these models for the case of hyper-matter. In this way we make
extension of nuclear reaction studies at low temperature into the strange
sector. We demonstrate how the new decay channels can be integrated in the
whole disintegration process. Their importance for mass and isotope
distributions of produced hyper-fragments is emphasized. New and exotic
isotopes obtained within these processes may provide a unique opportunity for
investigating hyperon interaction in nuclear matter.


title:
Biomimetic surface structuring using cylindrical vector femtosecond
  laser beams

abstract:
  We report on a new, single-step and scalable method to fabricate highly
ordered, multi-directional and complex surface structures that mimic the unique
morphological features of certain species found in nature. Biomimetic surface
structuring was realized by exploiting the unique and versatile angular profile
and the electric field symmetry of cylindrical vector (CV) femtosecond (fs)
laser beams. It is shown that, highly controllable, periodic structures
exhibiting sizes at nano-, micro- and dual-scale micro and nano scales can be
directly written on Ni upon line and large area scanning with radial and
azimuthal polarization beams. Depending on the irradiation conditions, new
complex multi-directional nanostructures, inspired by the Shark skin
morphology, as well as superhydrophobic dual-scale structures mimicking the
Lotus leaf water repellent properties can be attained. It is concluded that the
versatility and features variations of structures formed upon scanning with CV
beams is by far superior to those obtained via laser processing with linearly
polarized beams. More important, by exploiting the capabilities offered by fs
CV optical fields, the present technique can be further extended to fabricate
even more complex and unconventional structures. We believe that our approach
provides a new concept in laser processing of materials, which can be further
exploited for expanding the breadth and novelty of potential applications.


title:
Modelling correlated marker effects in genome-wide prediction via
  Gaussian concentration graph models

abstract:
  In genome-wide prediction, independence of marker allele substitution effects
is typically assumed; however, since early stages of this technology it has
been known that nature points to correlated effects. In statistics, graphical
models have been identified as a useful and powerful tool for covariance
estimation in high dimensional problems and it is an area that has recently
experienced a great expansion. In particular, Gaussian concentration graph
models (GCGM) have been widely studied. These are models in which the
distribution of a set of random variables, the marker effects in this case, is
assumed to be Markov with respect to an undirected graph G. In this paper,
Bayesian (Bayes G and Bayes G-D) and frequentist (GML-BLUP) methods adapting
the theory of GCGM to genome-wide prediction were developed. Different
approaches to define the graph G based on domain-specific knowledge were
proposed, and two propositions and a corollary establishing conditions to find
decomposable graphs were proven. These methods were implemented in small
simulated and real datasets. In our simulations, scenarios where correlations
among allelic substitution effects were expected to arise due to various causes
were considered, and graphs were defined on the basis of physical marker
positions. Results showed improvements in correlation between phenotypes and
predicted breeding values and accuracies of predicted breeding values when
accounting for partially correlated allele substitution effects. Extensions to
the multiallelic loci case were described and some possible refinements
incorporating more flexible priors in the Bayesian setting were discussed. Our
models are promising because they allow incorporation of biological information
in the prediction process, and because they are more flexible and general than
other models accounting for correlated marker effects that have been proposed
previously.


title: Minimizing cones associated with isoparametric foliations

abstract:
  Associated with isoparametric foliations of unit spheres, there are two
classes of minimal surfaces $-$ minimal isoparametric hypersurfaces and focal
submanifolds. By virtue of their rich structures, we find new series of
minimizing cones. They are cones over focal submanifolds and cones over
suitable products among these two classes. Except in low dimensions, all such
cones are shown minimizing.


title:
Proceedings of the Workshop on Brain Analysis using COnnectivity
  Networks - BACON 2016

abstract:
  Understanding brain connectivity in a network-theoretic context has shown
much promise in recent years. This type of analysis identifies brain
organisational principles, bringing a new perspective to neuroscience. At the
same time, large public databases of connectomic data are now available.
However, connectome analysis is still an emerging field and there is a crucial
need for robust computational methods to fully unravelits potential. This
workshop provides a platform to discuss the development of new analytic
techniques; methods for evaluating and validating commonly used approaches; as
well as the effects of variations in pre-processing steps.


title:
Probabilistic representation formula for the solution of fractional high
  order heat-type equations

abstract:
  We propose a probabilistic construction for the solution of a general class
of fractional high order heat-type equations in the one-dimensional case, by
using a sequence of random walks in the complex plane with a suitable scaling.
A time change governed by a class of subordinated processes allows to handle
the fractional part of the derivative in space. We first consider evolution
equations with space fractional derivatives of any order, and later we show the
extension to equations with time fractional derivative (in the sense of Caputo
derivative) of order $\alpha \in (0,1)$.


title: Venus Long-life Surface Package

abstract:
  Measurements in the atmosphere and at the surface of Venus are required to
understand fundamental processes of how terrestrial planets evolve and how they
work today. While the European Venus community is unified in its support of the
EnVision orbiter proposal for the M5 opportunity, many scientific questions
also require in situ Venus exploration. ESA has already explored Venus entry /
descent probe science in its Planetary Entry Probe (PEP) study [ESA PEP study,
2010], and Venus balloon science in its Venus Entry Probe Study [ESA VEP study,
2005]; Venus balloons were also explored in detail by the European Venus
Explorer (EVE) M1/M2 and M3 proposals [Chassefiere et al., 2009; Wilson et al.,
2012]. While those in situ mission concepts remain scientifically compelling
and technically feasible, the present call requests new scientific concepts.
Therefore, in the present document, we suggest a long-duration lander at Venus,
which would be capable of undertaking a seismometry mission, operating in the
460{\deg}C surface conditions of Venus.


title:
Reconstructing directed and weighted topologies of phase-locked
  oscillator networks

abstract:
  The formalism of complex networks is extensively employed to describe the
dynamics of interacting agents in several applications. The features of the
connections among the nodes in a network are not always provided beforehand,
hence the problem of appropriately inferring them often arises. Here, we
present a method to reconstruct directed and weighted topologies (REDRAW) of
networks of heterogeneous phase-locked nonlinear oscillators. We ultimately
plan on using REDRAW to infer the interaction structure in human ensembles
engaged in coordination tasks, and give insights into the overall behavior.


title: Remarks on Top-philic $Z^\prime$ Boson Interactions with Nucleons

abstract:
  This article provides the calculation of an effective vertex function between
a nucleon and a $Z^\prime$ boson that couples preferentially to either the top
quark or the third generation of fermions, for the purpose of calculating
vector-portal dark matter nuclear recoil cross sections. Mixing effects between
the new gauge group $U(1)^\prime$ and the Standard Model hypercharge group
$U(1)_Y$ are taken into account. Contributions to the $U(1)^\prime$ nucleon
current from heavy quarks are quantified using the heavy quark expansion. Also
taken into account are contributions from the 1-loop $Z^\prime$-gluon
interactions and mixing-induced contributions from the light quarks in the
nucleon. We find that, for reasonable values of the $U(1)^\prime$ gauge
parameter, contributions from the light quarks dominate despite being
mixing-suppressed. It is shown that this holds for most models even if mixing
effects do not appear at tree level. Contributions from the heavy quarks and
gluons are suppressed by $1/m_Q^2$ and possibly also by momentum in the low
momentum transfer limits relevant for dark matter direct detection. We discuss
under which conditions the subdominant terms become relevant.


title:
A mixed variational discretization for non-isothermal compressible flow
  in pipelines

abstract:
  We consider the non-isothermal flow of a compressible fluid through pipes.
Starting from the full set of Euler equations, we propose a variational
characterization of solutions that encodes the conservation of mass, energy,
and entropy in a very direct manner. This variational principle is suitable for
a conforming Galerkin approximation in space which automatically inherits the
basic physical conservation laws. Three different spaces are used for
approximation of density, mass flux, and temperature, and we consider a mixed
finite element method as one possible choice of suitable approximation spaces.
We also investigate the subsequent discretization in time by a problem adapted
implicit time stepping scheme for which exact conservation of mass as well as a
slight dissipation of energy and increase of entropy are proven which are due
to the numerical dissipation of the implicit time discretization. The main
arguments of our analysis are rather general and allow us to extend the
approach with minor modification to more general boundary conditions and flow
models taking into account friction, viscosity, heat conduction, and heat
exchange with the surrounding medium.


title: E11, Romans theory and higher level duality relations

abstract:
  From the underlying non-linear realisation we compute the complete E11
invariant equations of motion in eleven dimensions, at the linearised level, up
to and including level four in the fields. Thus we include the metric, the
three and six forms, the dual graviton and three fields at level four. The
fields are linked by a set of duality equations, which are first order in
derivatives and transform into each other under the E11 symmetries. From these
duality relations we deduce second order equations of motion, including those
for the usual supergravity fields. As a result the on-shell degrees of freedom
are those of the eleven dimensional supergravity. We also show that the level
four fields provide an eleven dimensional origin of Romans theory and lead to a
novel duality relation.


title: Couplings of NN(n\pi) n \geq 1

abstract:
  Determinations of the couplings of $N N (n \pi) (n \geq 1)$ are reported. The
study is based on both a quark model of nucleon and a chiral field theory of
mesons. The coupling of $N N \pi$ is predicted and is in agreement with current
value. It shows that the coupling $ N N 2 \pi $ is resulted in the nature that
pion is a Goldstone boson. The couplings of $N N (n \pi) (n \geq 2)$ are
predicted by this approach.


title: Fragmentation Functions Beyond Fixed Order Accuracy

abstract:
  We give a detailed account of the phenomenology of all-order resummations of
logarithmically enhanced contributions at small momentum fraction of the
observed hadron in semi-inclusive electron-positron annihilation and the
time-like scale evolution of parton-to-hadron fragmentation functions. The
formalism to perform resummations in Mellin moment space is briefly reviewed,
and all relevant expressions up to next-to-next-to-leading logarithmic order
are derived, including their explicit dependence on the factorization and
renormalization scales. We discuss the details pertinent to a proper numerical
implementation of the resummed results comprising an iterative solution to the
time-like evolution equations, the matching to known fixed-order expressions,
and the choice of the contour in the Mellin inverse transformation. First
extractions of parton-to-pion fragmentation functions from semi-inclusive
annihilation data are performed at different logarithmic orders of the
resummations in order to estimate their phenomenological relevance. To this
end, we compare our results to corresponding fits up to fixed,
next-to-next-to-leading order accuracy and study the residual dependence on the
factorization scale in each case.


title:
A stochastically verifiable autonomous control architecture with
  reasoning

abstract:
  A new agent architecture called Limited Instruction Set Agent (LISA) is
introduced for autonomous control. The new architecture is based on previous
implementations of AgentSpeak and it is structurally simpler than its
predecessors with the aim of facilitating design-time and run-time verification
methods. The process of abstracting the LISA system to two different types of
discrete probabilistic models (DTMC and MDP) is investigated and illustrated.
The LISA system provides a tool for complete modelling of the agent and the
environment for probabilistic verification. The agent program can be
automatically compiled into a DTMC or a MDP model for verification with Prism.
The automatically generated Prism model can be used for both design-time and
run-time verification. The run-time verification is investigated and
illustrated in the LISA system as an internal modelling mechanism for
prediction of future outcomes.


title: Meromorphic maps of Kahler manifolds with trivial canonical bundles

abstract:
  Let M be a (bounded or not) domain of C^n which is complete with respect to a
K\"ahler metric, or more generally, a complete K\"ahler manifold with trivial
canonical bundle. Let f be a linearly nondegenerate meromorphic map from M to
the complex projective space P^m. Under an assumption on the positivity of the
pull-back by f of the Fubini-Study form on P^m, we prove that f can not omit a
certain number of hyperplanes in subgeneral position in P^m. This is deduced
directly from a non-integrated defect relation for such f which generalizes
that obtained by Fujimoto in the case where M is a ball.


title:
Existence of strong minimizers for the Griffith static fracture model in
  dimension two

abstract:
  We consider the Griffith fracture model in two spatial dimensions, and prove
existence of strong minimizers, with closed jump set and continuously
differentiable deformation fields. One key ingredient, which is the object of
the present paper, is a generalization of the decay estimate by De Giorgi,
Carriero, and Leaci to the vectorial situation. This is based on replacing the
coarea formula by a method to approximate $SBD^p$ functions with small jump set
by Sobolev functions and is restricted to two dimensions. The other two
ingredients are contained in companion papers and consist respectively in
regularity results for vectorial elliptic problems of the elasticity type and
in a method to approximate in energy $GSBD^p$ functions by $SBV^p$ ones.


title: Quark Orbital Angular Momentum in the MIT Bag Model

abstract:
  We present the results for the Generalized Transverse Momentum Distribution
related to quark Orbital Angular Momentum, {\it i.e.} $F_{14}$, in the MIT bag
model. This model has been modified to include the Peierls--Yoccoz projection
to restore translational invariance. Such a modification allows to fulfill more
satisfactorily basic sum rules, that would otherwise be less elegantly carried
out with the original version. Using the same model, we have calculated the
twist-$3$ GPD that corresponds to Orbital Angular Momentum \`a la Ji, through
the Penttinen--Polyakov--Shuvaev--Strikman sum rule. Recently, a new relation
between the two definitions of the quark Orbital Angular Momentum at the
density level has been proposed, which we illustrate here within the model. The
sum rule is fulfilled. Still within the framework of the MIT bag model, we
analyze the Wandzura--Wilczek expression for the GPD of interest. The genuine
quark-gluon contribution is evaluated directly thanks to the equation of motion
of the bag, which allows for a direct control of the kinematical contributions
to the twist-3 GPD.


title:
Galaxy And Mass Assembly (GAMA): Active Galactic Nuclei in Pairs of
  Galaxies

abstract:
  There exist conflicting observations on whether or not the environment of
broad and narrow line AGN differ and this consequently questions the validity
of the AGN unification model. The high spectroscopic completeness of the GAMA
survey makes it ideal for a comprehensive analysis of the close environment of
galaxies. To exploit this, and conduct a comparative analysis of the
environment of broad and narrow line AGN within GAMA, we use a double-Gaussian
emission line fitting method to model the more complex line profiles associated
with broad line AGN. We select 209 type 1 (i.e., unobscured), 464 type 1.5-1.9
(partially obscured), and 281 type 2 (obscured) AGN within the GAMA II
database. Comparing the fractions of these with neighbouring galaxies out to a
pair separation of $350\,\text{kpc }h^{-1}$ and $\Delta z < 0.012$ shows no
difference between AGN of different type, except at separations less than
$20\,\text{kpc }h^{-1}$ where our observations suggest an excess of type 2 AGN
in close pairs. We analyse the properties of the galaxies neighbouring our AGN
and find no significant differences in colour or the star formation activity of
these galaxies. Further to this we find that $\Sigma_5$ is also consistent
between broad and narrow line AGN. We conclude that the observations presented
here are consistent with AGN unification.


title:
Open systems with error bounds: spin boson model with spectral density
  variations

abstract:
  In the study of open quantum systems, one of the most common ways to describe
environmental effects on the reduced dynamics is through the spectral density.
However, in many models this object cannot be computed from first principles
and needs to be inferred on phenomenological grounds or fitted to experimental
data. Consequently, some uncertainty regarding its form and parameters is
unavoidable; this in turn calls into question the accuracy of any theoretical
predictions based on a given spectral density. Here, we focus on the spin-boson
model as a prototypical open quantum system, and find two error bounds on
predicted expectation values in terms of the spectral density variation
considered, and state a sufficient condition for the strongest one to apply. We
further demonstrate an application of our result, by bounding the error brought
about by the approximations involved in the Hierarchical Equations of Motion
resolution method for spin-boson dynamics.


title: Spin-charge coupled dynamics driven by a time-dependent magnetization

abstract:
  The spin-charge coupled dynamics in a thin, magnetized metallic system are
investigated. The effective driving force acting on the charge carriers is
generated by a dynamical magnetic texture, which can be induced, e.g., by a
magnetic material in contact with a normal-metal system. We consider a general
inversion-asymmetric substrate/normal-metal/magnet structure, which, by
specifying the precise nature of each layer, can mimick various experimentally
employed setups. Inversion symmetry breaking gives rise to an effective Rashba
spin-orbit interaction. We derive general spin-charge kinetic equations which
show that such spin-orbit interaction, together with anisotropic Elliott-Yafet
spin relaxation, yields significant corrections to the magnetization-induced
dynamics. In particular, we present a consistent treatment of the spin density
and spin current contributions to the equations of motion, inter alia
identifying a novel term in the effective force which appears due to a spin
current polarized parallel to the magnetization. This "inverse spin filter"
contribution depends markedly on the parameter which describes the anisotropy
in spin relaxation. To further highlight the physical meaning of the different
contributions, the spin pumping configuration of typical experimental setups is
analyzed in detail. In the two-dimensional limit the build-up of a DC voltage
is dominated by the spin galvanic (inverse Edelstein) effect. A measuring
scheme that could isolate this contribution is discussed.


title:
Temperature-Insensitive Analog Vector-by-Matrix Multiplier Based on 55
  nm NOR Flash Memory Cells

abstract:
  We have fabricated and successfully tested an analog vector-by-matrix
multiplier, based on redesigned 10x12 arrays of 55 nm commercial NOR flash
memory cells. The modified arrays enable high-precision individual analog
tuning of each cell, with sub-1% accuracy, while keeping the highly optimized
cells, with their long-term state retention, intact. The array has an area of
0.33 um^2 per cell, and is at least one order of magnitude more dense than the
reported prior implementations of nonvolatile analog memories. The demonstrated
vector-by-vector multiplier, using gate coupling to additional periphery cells,
has ~2% precision, limited by the aggregate effect of cell noise, retention,
mismatch, process variations, tuning precision, and capacitive crosstalk. A
differential version of the multiplier has allowed us to demonstrate sub-3%
temperature drift of the output signal in the range between 25C and 85C.


title: In-Storage Embedded Accelerator for Sparse Pattern Processing

abstract:
  We present a novel architecture for sparse pattern processing, using flash
storage with embedded accelerators. Sparse pattern processing on large data
sets is the essence of applications such as document search, natural language
processing, bioinformatics, subgraph matching, machine learning, and graph
processing. One slice of our prototype accelerator is capable of handling up to
1TB of data, and experiments show that it can outperform C/C++ software
solutions on a 16-core system at a fraction of the power and cost; an optimized
version of the accelerator can match the performance of a 48-core server.


title:
Neutron$-^{19}$C scattering: emergence of universal properties in a
  finite range potential

abstract:
  The low-energy properties of the elastic $s-$wave scattering for the
$n-^{19}$C are studied near the critical condition for the occurrence of an
excited Efimov state in $n-n-^{18}$C. It is established to which extent the
universal scaling laws, strictly valid in the zero-range limit, survive when
finite range potentials are considered. By fixing the two-neutrons separation
energy in $^{20}$C with available experimental data, it is studied the scaling
of the real ($\delta_0^R$) and imaginary parts of the $s-$wave phase-shift with
the variation of the $n-^{18}$C binding energy. We obtain some universal
characteristics given by the pole-position of $k\cot(\delta_0^R)$ and
effective-range parameters. By increasing the $n-^{18}$C binding energy, it was
verified that the excited state of $^{20}$C goes to a virtual state, resembling
the neutron-deuteron behavior in the triton. It is confirmed that the
analytical structure of the unitary cut is not affected by the range of the
potential or mass asymmetry of the three-body system.


title: Efficient Summarization with Read-Again and Copy Mechanism

abstract:
  Encoder-decoder models have been widely used to solve sequence to sequence
prediction tasks. However current approaches suffer from two shortcomings.
First, the encoders compute a representation of each word taking into account
only the history of the words it has read so far, yielding suboptimal
representations. Second, current decoders utilize large vocabularies in order
to minimize the problem of unknown words, resulting in slow decoding times. In
this paper we address both shortcomings. Towards this goal, we first introduce
a simple mechanism that first reads the input sequence before committing to a
representation of each word. Furthermore, we propose a simple copy mechanism
that is able to exploit very small vocabularies and handle out-of-vocabulary
words. We demonstrate the effectiveness of our approach on the Gigaword dataset
and DUC competition outperforming the state-of-the-art.


title:
Disentangling factors of variation in deep representations using
  adversarial training

abstract:
  We introduce a conditional generative model for learning to disentangle the
hidden factors of variation within a set of labeled observations, and separate
them into complementary codes. One code summarizes the specified factors of
variation associated with the labels. The other summarizes the remaining
unspecified variability. During training, the only available source of
supervision comes from our ability to distinguish among different observations
belonging to the same class. Examples of such observations include images of a
set of labeled objects captured at different viewpoints, or recordings of set
of speakers dictating multiple phrases. In both instances, the intra-class
diversity is the source of the unspecified factors of variation: each object is
observed at multiple viewpoints, and each speaker dictates multiple phrases.
Learning to disentangle the specified factors from the unspecified ones becomes
easier when strong supervision is possible. Suppose that during training, we
have access to pairs of images, where each pair shows two different objects
captured from the same viewpoint. This source of alignment allows us to solve
our task using existing methods. However, labels for the unspecified factors
are usually unavailable in realistic scenarios where data acquisition is not
strictly controlled. We address the problem of disentanglement in this more
general setting by combining deep convolutional autoencoders with a form of
adversarial training. Both factors of variation are implicitly captured in the
organization of the learned embedding space, and can be used for solving
single-image analogies. Experimental results on synthetic and real datasets
show that the proposed method is capable of generalizing to unseen classes and
intra-class variabilities.


title:
Second-Harmonic Scattering as a Probe of Structural Correlations in
  Liquids

abstract:
  Second-harmonic scattering experiments of water and other bulk molecular
liquids have long been assumed to be insensitive to interactions between the
molecules. The measured intensity is generally thought to arise from incoherent
scattering due to individual molecules. We introduce a method to compute the
second-harmonic scattering pattern of molecular liquids directly from atomistic
computer simulations, which takes into account the coherent terms. We apply
this approach to large-scale molecular dynamics simulations of liquid water,
where we show that nanosecond second-harmonic scattering experiments contain a
coherent contribution arising from radial and angular correlations on a length
scale of < 1 nm, much shorter than had been recently hypothesized (Shelton, D.
P. J. Chem. Phys. 2014, 141). By combining structural correlations from
simulations with experimental data (Shelton, D. P. J. Chem. Phys. 2014, 141),
we can also extract an effective molecular hyperpolarizability in the liquid
phase. This work demonstrates that second-harmonic scattering experiments and
atomistic simulations can be used in synergy to investigate the structure of
complex liquids, solutions, and biomembranes, including the intrinsic
intermolecular correlations.


title: Approximately Sampling Elements with Fixed Rank in Graded Posets

abstract:
  Graded posets frequently arise throughout combinatorics, where it is natural
to try to count the number of elements of a fixed rank. These counting problems
are often $\#\textbf{P}$-complete, so we consider approximation algorithms for
counting and uniform sampling. We show that for certain classes of posets,
biased Markov chains that walk along edges of their Hasse diagrams allow us to
approximately generate samples with any fixed rank in expected polynomial time.
Our arguments do not rely on the typical proofs of log-concavity, which are
used to construct a stationary distribution with a specific mode in order to
give a lower bound on the probability of outputting an element of the desired
rank. Instead, we infer this directly from bounds on the mixing time of the
chains through a method we call $\textit{balanced bias}$.
  A noteworthy application of our method is sampling restricted classes of
integer partitions of $n$. We give the first provably efficient Markov chain
algorithm to uniformly sample integer partitions of $n$ from general restricted
classes. Several observations allow us to improve the efficiency of this chain
to require $O(n^{1/2}\log(n))$ space, and for unrestricted integer partitions,
expected $O(n^{9/4})$ time. Related applications include sampling permutations
with a fixed number of inversions and lozenge tilings on the triangular lattice
with a fixed average height.


title:
Recent progress in astrophysical plasma turbulence from solar wind
  observations

abstract:
  This paper summarises some of the recent progress that has been made in
understanding astrophysical plasma turbulence in the solar wind, from in situ
spacecraft observations. At large scales, where the turbulence is predominantly
Alfvenic, measurements of critical balance, residual energy, and 3D structure
are discussed, along with comparison to recent models of strong Alfvenic
turbulence. At these scales, a few percent of the energy is also in compressive
fluctuations, and their nature, anisotropy, and relation to the Alfvenic
component is described. In the small scale kinetic range, below the ion
gyroscale, the turbulence becomes predominantly kinetic Alfven in nature, and
measurements of the spectra, anisotropy, and intermittency of this turbulence
are discussed with respect to recent cascade models. One of the major remaining
questions is how the turbulent energy is dissipated, and some recent work on
this question, in addition to future space missions which will help to answer
it, are briefly discussed.

categories: physics.plasm-ph astro-ph.EP astro-ph.SR physics.space-ph


title:
Chained permutations and alternating sign matrices - inspired by
  three-person chess

abstract:
  We define and enumerate two new two-parameter permutation families, namely,
placements of a maximum number of non-attacking rooks on $k$ chained-together
$n\times n$ chessboards, in either a circular or linear configuration. The
linear case with $k=1$ corresponds to standard permutations of $n$, and the
circular case with $n=4$ and $k=6$ corresponds to a three-person chessboard. We
give bijections of these rook placements to matrix form, one-line notation, and
matchings on certain graphs. Finally, we define chained linear and circular
alternating sign matrices, enumerate them for certain values of $n$ and $k$,
and give bijections to analogues of monotone triangles, square ice
configurations, and fully-packed loop configurations.


title: Trion Valley Coherence in Monolayer Semiconductors

abstract:
  The emerging field of valleytronics aims to exploit the valley pseudospin of
electrons residing near Bloch band extrema as an information carrier. Recent
experiments demonstrating optical generation and manipulation of exciton valley
coherence (the superposition of electron-hole pairs at opposite valleys) in
monolayer transition metal dichalcogenides (TMDs) provide a critical step
towards control of this quantum degree of freedom. The charged exciton (trion)
in TMDs is an intriguing alternative to the neutral exciton for control of
valley pseudospin because of its long spontaneous recombination lifetime, its
robust valley polarization, and its coupling to residual electronic spin. Trion
valley coherence has however been unexplored due to experimental challenges in
accessing it spectroscopically. In this work, we employ ultrafast
two-dimensional coherent spectroscopy to resonantly generate and detect trion
valley coherence in monolayer MoSe$_2$ demonstrating that it persists for a
few-hundred femtoseconds. We conclude that the underlying mechanisms limiting
trion valley coherence are fundamentally different from those applicable to
exciton valley coherence. Based on these observations, we suggest possible
strategies for extending valley coherence times in two-dimensional materials.


title:
Robustness of Greenberger-Horne-Zeilinger and W states against
  Dzyaloshinshkii-Moriya interaction

abstract:
  In this article the robustness of tripartite Greenberger-Horne-Zeilinger
(GHZ) and W states is investigated against Dzyaloshinskii-Moriya (i.e. DM)
interaction. We consider a closed system of three qubits and an environmental
qubit. The environmental qubit interacts with any one of the three qubits
through DM interaction. The tripartite system is initially prepared in GHZ and
W states respectively. The composite four qubits system evolve with unitary
dynamics. We detach the environmental qubit by tracing out from four qubits and
profound impact of DM interaction is studied on the initial entanglement of the
system. As a result we find that the bipartite partitions of W states suffer
from entanglement sudden death (i.e. ESD), while tripartite entanglement does
not. On the other hand bipartite partitions and tripartite entanglement in GHZ
states does not feel any influence of DM interaction. So, we find that GHZ
states have robust character than W states. In this work we consider
generalised GHZ and W states and three $\pi$ is used as an entanglement
measure. This study can be useful in quantum information processing where
unwanted DM interaction takes place.


title: Anthropogenic Space Weather

abstract:
  Anthropogenic effects on the space environment started in the late 19th
century and reached their peak in the 1960s when high-altitude nuclear
explosions were carried out by the USA and the Soviet Union. These explosions
created artificial radiation belts near Earth that resulted in major damages to
several satellites. Another, unexpected impact of the high-altitude nuclear
tests was the electromagnetic pulse (EMP) that can have devastating effects
over a large geographic area (as large as the continental United States). Other
anthropogenic impacts on the space environment include chemical release ex-
periments, high-frequency wave heating of the ionosphere and the interaction of
VLF waves with the radiation belts. This paper reviews the fundamental physical
process behind these phenomena and discusses the observations of their impacts.


title:
An equilibrated fluxes approach to the certified descent algorithm for
  shape optimization using conforming finite element and discontinuous Galerkin
  discretizations

abstract:
  The certified descent algorithm (CDA) is a gradient-based method for shape
optimization which certifies that the direction computed using the shape
gradient is a genuine descent direction for the objective functional under
analysis. It relies on the computation of an upper bound of the error
introduced by the finite element approximation of the shape gradient. In this
paper, we present a goal-oriented error estimator which depends solely on local
quantities and is fully-computable. By means of the equilibrated fluxes
approach, we construct a unified strategy valid for both conforming finite
element approximations and discontinuous Galerkin discretizations. The new
variant of the CDA is tested on the inverse identification problem of
electrical impedance tomography: both its ability to identify a genuine descent
direction at each iteration and its reliable stopping criterion are confirmed.


title:
Ultra-high vacuum compatible preparation chain for intermetallic
  compounds

abstract:
  We report the development of a versatile material preparation chain for
intermetallic compounds that focuses on the realization of a high-purity growth
environment. The preparation chain comprises of an argon glovebox, an
inductively heated horizontal cold boat furnace, an arc melting furnace, an
inductively heated rod casting furnace, an optically heated floating-zone
furnace, a resistively heated annealing furnace, and an inductively heated
annealing furnace. The cold boat furnace and the arc melting furnace may be
loaded from the glovebox by means of a load-lock permitting to synthesize
compounds starting with air-sensitive elements while handling the constituents
exclusively in an inert gas atmosphere. All furnaces are all-metal sealed,
bakeable, and may be pumped to ultra-high vacuum. We find that the latter
represents an important prerequisite for handling compounds with high vapor
pressure under high-purity argon atmosphere. We illustrate operational aspects
of the preparation chain in terms of the single-crystal growth of the
heavy-fermion compound CeNi2Ge2.


title:
Anisotropic inflation with a non-minimally coupled electromagnetic field
  to gravity

abstract:
  We consider the non-minimal model of gravity in $Y(R) F^2$-form. We
investigate a particular case of the model, for which the higher order
derivatives are eliminated but the scalar curvature $R$ is kept to be dynamical
via the constraint $Y_RF_{mn}F^{mn} =-\frac{2}{\kappa^2}$. The effective fluid
obtained can be represented by interacting electromagnetic field and vacuum
depending on $Y(R)$, namely, the energy density of the vacuum tracks $R$ while
energy density of the conventional electromagnetic field is dynamically scaled
with the factor $\frac{Y(R)}{2}$. We give exact solutions for anisotropic
inflation by assuming the volume scale factor of the Universe exhibits a
power-law expansion. The directional scale factors do not necessarily exhibit
power-law expansion, which would give rise to a constant expansion anisotropy,
but expand non-trivially and give rise to a non-monotonically evolving
expansion anisotropy that eventually converges to a non-zero constant. Relying
on this fact, we discuss the anisotropic e-fold during the inflation by
considering observed scale invariance in CMB and demanding the Universe to
undergo the same amount of e-folds in all directions. We calculate the residual
expansion anisotropy at the end of inflation, though as a result of
non-monotonic behaviour of expansion anisotropy all the axes of the Universe
undergo the same of amount of e-folds by the end of inflation. We also discuss
the generation of the modified electromagnetic field during the first few
e-folds of the inflation and its persistence against to the vacuum till end of
inflation.


title: Snowflake growth in three dimensions using phase field modelling

abstract:
  Snowflake growth provides us with a fascinating example of spontaneous
pattern formation in nature. Attempts to understand this phenomenon have led to
important insights in non-equilibrium dynamics observed in various active
scientific fields, ranging from pattern formation in physical and chemical
systems, to self-assembly problems in biology. Yet, very few models currently
succeed in reproducing the diversity of snowflake forms in three dimensions,
and the link between model parameters and thermodynamic quantities is not
established. Here, we report a modified phase field model that describes the
subtlety of the ice vapour phase transition, through anisotropic water
molecules attachment and condensation, surface diffusion, and strong
anisotropic surface tension, that guarantee the anisotropy, faceting and
dendritic growth of snowflakes. We demonstrate that this model reproduces the
growth dynamics of the most challenging morphologies of snowflakes from the
Nakaya diagram. We find that the growth dynamics of snow crystals matches the
selection theory, consistently with previous experimental observations.


title:
Extracting information from random data. Applications of laws of large
  numbers in technical sciences and statistics

abstract:
  We formulate conditions for convergence of Laws of Large Numbers and show its
links with of the parts of mathematical analysis such as summation theory,
convergence of orthogonal series. We present also applications of the Law of
Large Numbers such as Stochastic Approximation, Density and Regression
Estimation, Identification.


title: On a spectral theorem of Weyl

abstract:
  We give a geometric proof of a theorem of Weyl on the continuous part of the
spectrum of Sturm-Liouville operators on the half-line with asymptotically
constant coefficients. Earlier proofs due to Weyl and Kodaira depend on special
features of Green's functions for linear ordinary differential operators; ours
might offer better prospects for generalization to higher dimensions, as
required for example in noncommutative harmonic analysis.


title:
Suppression of kHz-Frequency Switching Noise in Digital Micro-Mirror
  Devices

abstract:
  High resolution digital micro-mirror devices (DMD) make it possible to
produce nearly arbitrary light fields with high accuracy, reproducibility and
low optical aberrations. However, using these devices to trap and manipulate
ultracold atomic systems for e.g. quantum simulation is often complicated by
the presence of kHz-frequency switching noise. Here we demonstrate a simple
hardware extension that solves this problem and makes it possible to produce
truly static light fields. This modification leads to a 47 fold increase in the
time that we can hold ultracold $^6$Li atoms in a dipole potential created with
the DMD. Finally, we provide reliable and user friendly APIs written in Matlab
and Python to control the DMD.


title:
XCSP3: An Integrated Format for Benchmarking Combinatorial Constrained
  Problems

abstract:
  We propose a major revision of the format XCSP 2.1, called XCSP3, to build
integrated representations of combinatorial constrained problems. This new
format is able to deal with mono/multi optimization, many types of variables,
cost functions, reification, views, annotations, variable quantification,
distributed, probabilistic and qualitative reasoning. The new format is made
compact, highly readable, and rather easy to parse. Interestingly, it captures
the structure of the problem models, through the possibilities of declaring
arrays of variables, and identifying syntactic and semantic groups of
constraints. The number of constraints is kept under control by introducing a
limited set of basic constraint forms, and producing almost automatically some
of their variations through lifting, restriction, sliding, logical combination
and relaxation mechanisms. As a result, XCSP3 encompasses practically all
constraints that can be found in major constraint solvers developed by the CP
community. A website, which is developed conjointly with the format, contains
many models and series of instances. The user can make sophisticated queries
for selecting instances from very precise criteria. The objective of XCSP3 is
to ease the effort required to test and compare different algorithms by
providing a common test-bed of combinatorial constrained instances.


title:
Impact of Theory Uncertainties on the Precision of the Top Quark Mass in
  a Threshold Scan at Future e+e- Colliders

abstract:
  Future energy-frontier electron-positron colliders will be capable of
high-precision studies of top quark properties. The measurement of the top-pair
production cross section around the threshold provides access to the mass of
the top quark in theoretically well-defined schemes, with statistical
uncertainties of 20 MeV or less, depending on the assumed integrated luminosity
of the measurement. At this level of precision, experimental and theory
systematics are likely to become important or even dominant. This contribution
presents a first analysis of the impact of the remaining uncertainties of the
recently completed calculation of the top pair production cross section at
NNNLO QCD including the exchange of Higgs bosons on the extraction of the top
quark mass from a threshold scan. The analysis is based on reconstruction
efficiencies and background levels obtained in full simulation studies for
CLIC, combined with signal cross sections from the higher-order calculations.
To assess possible differences between different collider options, the study is
performed in the context of CLIC, ILC and FCC-ee by considering the differences
in the luminosity spectra.


title: Lattice Parameters Guide Superconductivity in Iron-Arsenides

abstract:
  The discovery of superconducting materials has led to their use in
technological marvels such as magnetic-field sensors in MRI machines, powerful
research magnets, short transmission cables, and high-speed trains. Despite
such applications, the uses of superconductors are not widespread because they
function much below room-temperature, hence the costly cooling. Since the
discovery of Cu- and Fe-based high-temperature superconductors (HTS), much
intense effort has tried to explain and understand the superconducting
phenomenon. While no exact explanations are given, several trends are reported
in relation to the materials basis in magnetism and spin excitations. In fact,
most HTS have antiferromagnetic undoped 'parent' materials that undergo a
superconducting transition upon small chemical substitutions in them. As it is
currently unclear which 'dopants' can favor superconductivity, this manuscript
investigates crystal structure changes upon chemical substitutions, to find
clues in lattice parameters for the superconducting occurrence. We review the
chemical substitution effects on the crystal lattice of iron-arsenide-based
crystals (2008 to present). We note that (a) HTS compounds have nearly
tetragonal structures with a-lattice parameter close to 4 A, and (b)
superconductivity can depend strongly on the c-lattice parameter changes with
chemical substitution. For example, a decrease in c-lattice parameter is
required to induce 'in-plane' superconductivity. The review of lattice
parameter trends in iron-arsenides presented here should guide synthesis of new
materials and provoke theoretical input, giving clues for HTS.


title:
Nanometer resolution imaging and tracking of fluorescent molecules with
  minimal photon fluxes

abstract:
  We introduce MINFLUX, a concept for localizing photon emitters in space. By
probing the emitter with a local intensity minimum of excitation light, MINFLUX
minimizes the fluorescence photons needed for high localization precision. A
22-fold reduction of photon detections over that required in popular
centroid-localization is demonstrated. In superresolution microscopy, MINFLUX
attained ~1 nm precision, resolving molecules only 6 nm apart. Tracking single
fluorescent proteins by MINFLUX increased the temporal resolution and the
localizations per trace by 100-fold, as demonstrated with diffusing 30S
ribosomal subunits in living E. coli. Since conceptual limits have not been
reached, we expect this localization modality to break new ground for observing
the dynamics, distribution, and structure of macromolecules in living cells and
beyond.


title:
Study of crystal-field splitting in ultrathin CePt$_5$ layers by Raman
  spectroscopy

abstract:
  Low-temperature electronic properties of rare-earth intermetallics are
substantially influenced by the symmetry and magnitude of the crystal electric
field. The direct spectroscopic analysis of crystal field splitting can be
challenging, especially in low-dimensional systems, because it requires both
high spectral resolution and pronounced sensitivity. We demonstrate the
eligibility of electronic Raman spectroscopy for this purpose by the direct
determination of the $4f$ level splitting in ultra-thin ordered CePt$_5$ films
down to 1.7 nm thickness on Pt(111). Crystal field excitations of Ce $4f$
electrons give rise to Raman peaks with energy shifts up to $\approx$ 25 meV.
Three distinct peaks occur which we attribute to inequivalent Ce sites, located
(i) at the interface to the substrate, (ii) next to the Pt-terminated surface,
and (iii) in the CePt$_5$ layers in between. The well-resolved Raman signatures
allow us to identify a reduced crystal field splitting at the interface and an
enhancement at the surface, highlighting its strong dependence on the local
atomic environment.


title:
Synergistic Dynamic Theory of Complex Coevolutionary Systems:
  Disentangling Nonlinear Spatiotemporal Controls on Precipitation

abstract:
  We formulate a nonlinear synergistic theory of coevolutionary systems,
disentangling and explaining dynamic complexity in terms of fundamental
processes for optimised data analysis and dynamic model design: Dynamic Source
Analysis (DSA). DSA provides a nonlinear dynamical basis for spatiotemporal
datasets or dynamical models, eliminating redundancies and expressing the
system in terms of the smallest number of fundamental processes and
interactions without loss of information. This optimises model design in
dynamical systems, expressing complex coevolution in simple synergistic terms,
yielding physically meaningful spatial and temporal structures. These are
extracted by spatiotemporal decomposition of nonlinearly interacting subspaces
via the novel concept of a Spatiotemporal Coevolution Manifold. Physical
consistency is ensured and mathematical ambiguities are avoided with
fundamental principles on energy minimisation and entropy production. The
relevance of DSA is illustrated by retrieving a non-redundant, synergistic set
of nonlinear geophysical processes exerting control over precipitation in space
and time over the Euro-Atlantic region. For that purpose, a nonlinear
spatiotemporal basis is extracted from geopotential data fields, yielding two
independent dynamic sources dominated respectively by meridional and zonal
circulation gradients. These sources are decomposed into spatial and temporal
structures corresponding to multiscale climate dynamics. The added value of
nonlinear predictability is brought out in the geospatial evaluation and
dynamic simulation of evolving precipitation distributions from the geophysical
controls, using DSA-driven model building and implementation. The simulated
precipitation is found to be in agreement with observational data, which they
not only describe but also dynamically link and attribute in synergistic terms
of the retrieved dynamic sources.


title:
Learning an Astronomical Catalog of the Visible Universe through
  Scalable Bayesian Inference

abstract:
  Celeste is a procedure for inferring astronomical catalogs that attains
state-of-the-art scientific results. To date, Celeste has been scaled to at
most hundreds of megabytes of astronomical images: Bayesian posterior inference
is notoriously demanding computationally. In this paper, we report on a
scalable, parallel version of Celeste, suitable for learning catalogs from
modern large-scale astronomical datasets. Our algorithmic innovations include a
fast numerical optimization routine for Bayesian posterior inference and a
statistically efficient scheme for decomposing astronomical optimization
problems into subproblems.
  Our scalable implementation is written entirely in Julia, a new high-level
dynamic programming language designed for scientific and numerical computing.
We use Julia's high-level constructs for shared and distributed memory
parallelism, and demonstrate effective load balancing and efficient scaling on
up to 8192 Xeon cores on the NERSC Cori supercomputer.


title:
Acceptable risks and related decision problems with multiple risk-averse
  agents

abstract:
  In this paper, we consider a risk-averse decision problem for
controlled-diffusion processes, with dynamic risk measures, in which multiple
risk-averse agents choose their decisions in such a way to minimize their
individual accumulated risk-costs over a finite-time horizon. In particular, we
introduce multi-structure dynamic risk measures induced from conditional
$g$-expectations, where the latter are associated with the generator
functionals of certain BSDEs that implicitly take into account the risk-cost
functionals of the risk-averse agents. Here, we also require that such
solutions of the BSDEs to satisfy a stochastic viability property with respect
to a given closed convex set. Moreover, using a result similar to that of the
Arrow-Barankin-Blackwell theorem, we establish the existence of consistent
optimal decisions for the risk-averse agents, when the set of all Pareto
optimal solutions, in the sense of viscosity, for the associated dynamic
programming equations is dense in the given closed convex set. Finally, we
briefly comment on the characteristics of acceptable risks vis-\'{a}-vis some
uncertain future costs or outcomes, in which results from the dynamic risk
analysis constitute part of the information used in the risk-averse decision
criteria.


title:
A millikelvin all-fiber cavity optomechanical apparatus for merging with
  ultra-cold atoms in a hybrid quantum system

abstract:
  We describe the construction of an apparatus designed to realize a hybrid
quantum system comprised of a cryogenically cooled mechanical oscillator and
ultra-cold $^{87}$Rb atoms coupled via light. The outstanding feature of our
instrument is an in-situ adjustable asymmetric all-fiber membrane-in-the-middle
cavity located inside an ultra-high vacuum dilution refrigerator based
cryostat. We show that Bose-Einstein condensates of $N=2\times10^6$ atoms can
be produced in less than 20 s and demonstrate a single photon optomechanical
coupling strength of $g_0=2\pi\times9$ kHz employing a high-stress Si$_3$N$_4$
membrane with a mechanical quality factor $Q_{\rm m}>10^7$ at a cavity set-up
temperature of $T_{\rm MiM}=480$ mK.


title:
Investigating the Potential of the Inter-IXP Multigraph for the
  Provisioning of Guaranteed End-to-End Services

abstract:
  In this work, we propose utilizing the rich connectivity between IXPs and
ISPs for inter-domain path stitching, supervised by centralized QoS brokers. In
this context, we highlight a novel abstraction of the Internet topology, i.e.,
the inter-IXP multigraph composed of IXPs and paths crossing the domains of
their shared member ISPs. This can potentially serve as a dense Internet-wide
substrate for provisioning guaranteed end-to-end (e2e) services with high path
diversity and global IPv4 address space reach. We thus map the IXP multigraph,
evaluate its potential, and introduce a rich algorithmic framework for path
stitching on such graph structures.


title:
Wavepackets in inhomogeneous periodic media: effective particle-field
  dynamics and Berry curvature

abstract:
  We consider a model of an electron in a crystal moving under the influence of
an external electric field: Schr\"{o}dinger's equation with a potential which
is the sum of a periodic function and a general smooth function. We identify
two dimensionless parameters: (re-scaled) Planck's constant and the ratio of
the lattice spacing to the scale of variation of the external potential. We
consider the special case where both parameters are equal and denote this
parameter $\epsilon$. In the limit $\epsilon \downarrow 0$, we prove the
existence of solutions known as semiclassical wavepackets which are asymptotic
up to `Ehrenfest time' $t \sim \ln 1/\epsilon$. To leading order, the center of
mass and average quasi-momentum of these solutions evolve along trajectories
generated by the classical Hamiltonian given by the sum of the Bloch band
energy and the external potential. We then derive all corrections to the
evolution of these observables proportional to $\epsilon$. The corrections
depend on the gauge-invariant Berry curvature of the Bloch band, and a coupling
to the evolution of the wave-packet envelope which satisfies Schr\"{o}dinger's
equation with a time-dependent harmonic oscillator Hamiltonian. This infinite
dimensional coupled `particle-field' system may be derived from an `extended'
$\epsilon$-dependent Hamiltonian. It is known that such coupling of observables
(discrete particle-like degrees of freedom) to the wave-envelope (continuum
field-like degrees of freedom) can have a significant impact on the overall
dynamics.

categories: math-ph cond-mat.mes-hall math.AP math.MP quant-ph


title: Complementarity in lepton-flavour violating muon decay experiments

abstract:
  This note presents an analysis of lepton-flavour-violating muon decays within
the framework of a low-energy effective field theory that contains
higher-dimensional operators allowed by QED and QCD symmetries. The decay modes
$\mu\to e \gamma$ and $\mu\to 3e$ are investigated below the electroweak
symmetry-breaking scale, down to energies at which such processes occur, i.e.
the muon mass scale. The complete class of dimension-5 and dimension-6
operators is studied systematically at the tree level, and one-loop
contributions to the renormalisation group equations are fully taken into
account. Current experimental limits are used to extract bounds on the Wilson
coefficients of some of the operators and, ultimately, on the effective
couplings at any energy level below the electroweak symmetry-breaking scale.
Correlations between two couplings relevant to both processes illustrate the
complementarity of searches planned for the MEG II and Mu3e experiments.


title: Binomial Checkpointing for Arbitrary Programs with No User Annotation

abstract:
  Heretofore, automatic checkpointing at procedure-call boundaries, to reduce
the space complexity of reverse mode, has been provided by systems like
Tapenade. However, binomial checkpointing, or treeverse, has only been provided
in Automatic Differentiation (AD) systems in special cases, e.g., through
user-provided pragmas on DO loops in Tapenade, or as the nested taping
mechanism in adol-c for time integration processes, which requires that user
code be refactored. We present a framework for applying binomial checkpointing
to arbitrary code with no special annotation or refactoring required. This is
accomplished by applying binomial checkpointing directly to a program trace.
This trace is produced by a general-purpose checkpointing mechanism that is
orthogonal to AD.


title:
First principle thermodynamic study of oxygen vacancy at metal/oxide
  interface

abstract:
  The oxygen vacancy is a crucial intrinsic defect in metal-ultrathin oxide
semiconductor heterostructures, and its formation at an interface is of great
importance in determining the device performance and degradation. This paper
presents an ab initio thermodynamic study of oxygen vacancies at metal/oxide
interfaces. Electronic energies and entropies are calculated for defective
interface systems, as a function of interface-vacancy distance. The study
indicates that oxygen vacancies near the interface modify its bonding
structure, and significantly change the thermodynamic properties of the system
(i.e., electronic energy and entropy) compared to bulk-like oxygen vacancies.
We illustrate that different factors, including the vacancy location dependence
on the energy and entropy, the temperature dependence on the entropy, and the
temperature and partial pressure dependence on the oxygen chemical potential,
are all important in determining the Gibbs free energy of formation of oxygen
vacancy.


title: Emergence of Luttinger Liquid behavior of a superclimbing dislocation

abstract:
  A superclimbing dislocation spread over several valleys of Peierls potential
in solid Helium-4 represents a non-Luttinger Liquid according to the elementary
scaling dimensional analysis because its excitation spectrum is parabolic.
Monte Carlo simulations, however, reveal that such a dislocation develops
Luttinger Liquid behavior, which can also undergo a transition into insulating
state. External bias can restore the parabolic spectrum. An experimental
verification of the effect is proposed.


title:
Stochastic representation of the Reynolds transport theorem: revisiting
  large-scale modeling

abstract:
  We explore the potential of a formulation of the Navier-Stokes equations
incorporating a random description of the small-scale velocity component. This
model, established from a version of the Reynolds transport theorem adapted to
a stochastic representation of the flow, gives rise to a large-scale
description of the flow dynamics in which emerges an anisotropic subgrid
tensor, reminiscent to the Reynolds stress tensor, together with a drift
correction due to an inhomogeneous turbulence. The corresponding subgrid model,
which depends on the small scales velocity variance, generalizes the Boussinesq
eddy viscosity assumption. However, it is not anymore obtained from an analogy
with molecular dissipation but ensues rigorously from the random modeling of
the flow. This principle allows us to propose several subgrid models defined
directly on the resolved flow component. We assess and compare numerically
those models on a standard Green-Taylor vortex flow at Reynolds 1600. The
numerical simulations, carried out with an accurate divergence-free scheme,
outperform classical large-eddies formulations and provides a simple
demonstration of the pertinence of the proposed large-scale modeling.


title:
Identifying potentially induced seismicity and assessing statistical
  significance in Oklahoma and California

abstract:
  We develop a statistical method for identifying induced seismicity from large
datasets and apply the method to decades of wastewater disposal and seismicity
data in California and Oklahoma. The method is robust against a variety of
potential pitfalls. The study regions are divided into gridblocks. We use a
longitudinal study design, seeking associations between seismicity and
wastewater injection along time-series within each gridblock. The longitudinal
design helps control for non-random application of wastewater injection. We
define a statistical model that is flexible enough to describe the seismicity
observations, which have temporal correlation and high kurtosis. In each
gridblock, we find the maximum likelihood estimate for a model parameter that
relates induced seismicity hazard to total volume of wastewater injected each
year. To assess significance, we compute likelihood ratio test statistics in
each gridblock and each state, California and Oklahoma. Resampling is used to
empirically derive reference distributions used to estimate p-values from the
likelihood ratio statistics. In Oklahoma, the analysis finds with extremely
high confidence that seismicity associated with wastewater disposal (or other
related activities, such as reservoir depletion) has occurred. In California,
the analysis finds that seismicity associated with wastewater disposal has
probably occurred, but the result is not strong enough to be conclusive. We
identify areas where temporal association between wastewater disposal and
seismicity is apparent. Our method could be applied to other datasets, extended
to identify risk factors that increase induced seismic hazard, or modified to
test alternative statistical models for natural and induced seismicity.


title:
Holographic Entanglement Entropy for Gravitational Anomaly in Four
  Dimensions

abstract:
  We compute the holographic entanglement entropy for the anomaly polynomial
$\mathrm{Tr} R^2$ in 3+1 dimensions. Using the perturbative method developed
for computing entanglement entropy for quantum field theories, we also compute
the parity odd contribution to the entanglement entropy of the dual field
theory that comes from a background gravitational Chern-Simons term. We find
that, in leading order in the perturbation of the background geometry, the two
contributions match except for a logarithmic divergent term on the field theory
side. We interpret this extra contribution as encoding our ignorance of the
source which creates the perturbation of the geometry.


title: Efficient Implementation of a Higher-Order Language with Built-In AD

abstract:
  We show that Automatic Differentiation (AD) operators can be provided in a
dynamic language without sacrificing numeric performance. To achieve this,
general forward and reverse AD functions are added to a simple high-level
dynamic language, and support for them is included in an aggressive optimizing
compiler. Novel technical mechanisms are discussed, which have the ability to
migrate the AD transformations from run-time to compile-time. The resulting
system, although only a research prototype, exhibits startlingly good
performance. In fact, despite the potential inefficiencies entailed by support
of a functional-programming language and a first-class AD operator, performance
is competitive with the fastest available preprocessor-based Fortran AD
systems. On benchmarks involving nested use of the AD operators, it can even
dramatically exceed their performance.


title:
On Explicit Approximations for L\'evy Driven SDEs with Super-linear
  Diffusion Coefficients

abstract:
  Motivated by the results of \cite{sabanis2015}, we propose explicit
Euler-type schemes for SDEs with random coefficients driven by L\'evy noise
when the drift and diffusion coefficients can grow super-linearly. As an
application of our results, one can construct explicit Euler-type schemes for
SDEs with delays (SDDEs) which are driven by L\'evy noise and have super-linear
coefficients. Strong convergence results are established and their rate of
convergence is shown to be equal to that of the classical Euler scheme. It is
proved that the optimal rate of convergence is achieved for
$\mathcal{L}^2$-convergence which is consistent with the corresponding results
available in the literature.


title:
Fundamental frequencies and resonances from eccentric and precessing
  binary black hole inspirals

abstract:
  Binary black holes which are both eccentric and undergo precession remain
unexplored in numerical simulations. We present simulations of such systems
which cover about 50 orbits at comparatively high mass ratios 5 and 7. The
configurations correspond to the generic motion of a nonspinning body in a Kerr
spacetime, and are chosen to study the transition from finite mass-ratio
inspirals to point particle motion in Kerr. We develop techniques to extract
analogs of the three fundamental frequencies of Kerr geodesics, compare our
frequencies to those of Kerr, and show that the differences are consistent with
self-force corrections entering at first order in mass ratio. This analysis
also locates orbital resonances where the ratios of our frequencies take
rational values. At the considered mass ratios, the binaries pass through
resonances in one to two resonant cycles, and we find no discernible effects on
the orbital evolution. We also compute the decay of eccentricity during the
inspiral and find good agreement with the leading order post-Newtonian
prediction.


title:
Elastic properties of solid material with various arrangements of
  spherical voids

abstract:
  In this work the linear elastic properties of materials containing spherical
voids are calculated and compared using finite element simulations. The focus
is on homogeneous solid materials with spherical, empty voids of equal size.
The voids are arranged on crystalline lattices (SC, BCC, FCC and HCP structure)
or randomly, and may overlap in order to produce connected voids. In that way,
the entire range of void fraction between 0.00 and 0.95 is covered, including
closed-cell and open-cell structures. For each arrangement of voids and for
different void fractions the full stiffness tensor is computed. From this, the
Young's modulus and Poisson ratios are derived for different orientations.
Special care is taken of assessing and reducing the numerical uncertainty of
the method. In that way, a reliable quantitative comparison of different void
structures is carried out. Among other things, this work shows that the Young's
modulus of FCC in the (1 1 1) plane differs from HCP in the (0 0 0 1) plane,
even though these structures are very similar. For a given void fraction SC
offers the highest and the lowest Young's modulus depending on the direction.
For BCC at a critical void fraction a switch of the elastic behaviour is found,
as regards the direction in which the Young's modulus is maximised. For certain
crystalline void arrangements and certain directions Poisson ratios between 0
and 1 were found, including values that exceed the bounds for isotropic
materials. For subsequent investigations the full stiffness tensor for a range
of void arrangements and void fractions are provided in the supplemental
material.


title: Location and Position Estimation in Wireless Sensor Networks

abstract:
  A wireless sensor network comprises of small sensor nodes each of which
consists of a processing device, small amount of memory, battery and radio
transceiver for communication. The sensor nodes are autonomous and spatially
distributed in an area of investigation. Certain applications and protocols of
wireless sensor networks require that the sensor nodes should be aware of their
position relative to the sensor network. For it to be significant and to be of
value, the data such as temperature, humidity and pressure, gathered by sensor
nodes must be ascribed to the relative position from where it was collected.
For this to happen, the sensor nodes must be aware of their relative positions.
Traditional location finding solutions, such as Global Positioning System, are
not feasible for wireless sensor nodes due to multiple reasons. Therefore, new
methods, techniques and algorithms need to be developed to solve the problem of
location and position estimation of wireless sensor nodes. A number of
algorithms and techniques based upon different characteristics and properties
of sensor nodes have already been proposed for this purpose. This chapter
discusses the basic principles and techniques used in the localization
algorithms, categories of these algorithms and also takes a more closer look at
a few of the representative localization schemes.


title:
Measurement of Jet Production Cross Sections in Deep-inelastic ep
  Scattering at HERA

abstract:
  A precision measurement of jet cross sections in neutral current
deep-inelastic scattering for photon virtualities $5.5<Q^2<80\,{\rm GeV}^2$ and
inelasticities $0.2<y<0.6$ is presented, using data taken with the H1 detector
at HERA, corresponding to an integrated luminosity of $290\,{\rm pb}^{-1}$.
Double-differential inclusive jet, dijet and trijet cross sections are measured
simultaneously and are presented as a function of jet transverse momentum
observables and as a function of $Q^2$. Jet cross sections normalised to the
inclusive neutral current DIS cross section in the respective $Q^2$-interval
are also determined. Previous results of inclusive jet cross sections in the
range $150<Q^2<15\,000\,{\rm GeV}^2$ are extended to low transverse jet momenta
$5<P_{T}^{\rm jet}<7\,{\rm GeV}$. The data are compared to predictions from
perturbative QCD in next-to-leading order in the strong coupling, in
approximate next-to-next-to-leading order and in full next-to-next-to-leading
order. Using also the recently published H1 jet data at high values of $Q^2$,
the strong coupling constant $\alpha_s(M_Z)$ is determined in next-to-leading
order.


title: Estimating stellar wind parameters from low-resolution magnetograms

abstract:
  Stellar winds govern the angular momentum evolution of solar-like stars
throughout their main-sequence lifetime. The efficiency of this process depends
on the geometry of the star's magnetic field. There has been a rapid increase
recently in the number of stars for which this geometry can be determined
through spectropolarimetry. We present a computationally efficient method to
determine the 3D geometry of the stellar wind and to estimate the mass loss
rate and angular momentum loss rate based on these observations. Using solar
magnetograms as examples, we quantify the extent to which the values obtained
are affected by the limited spatial resolution of stellar observations. We find
that for a typical stellar surface resolution of 20$^{\rm o}$-30$^{\rm o}$,
predicted wind speeds are within 5$\%$ of the value at full resolution. Mass
loss rates and angular momentum loss rates are within 5-20$\%$. In contrast,
the predicted X-ray emission measures can be under-estimated by 1-2 orders of
magnitude, and their rotational modulations by 10-20$\%$.


title: DiffSharp: An AD Library for .NET Languages

abstract:
  DiffSharp is an algorithmic differentiation or automatic differentiation (AD)
library for the .NET ecosystem, which is targeted by the C# and F# languages,
among others. The library has been designed with machine learning applications
in mind, allowing very succinct implementations of models and optimization
routines. DiffSharp is implemented in F# and exposes forward and reverse AD
operators as general nestable higher-order functions, usable by any .NET
language. It provides high-performance linear algebra primitives---scalars,
vectors, and matrices, with a generalization to tensors underway---that are
fully supported by all the AD operators, and which use a BLAS/LAPACK backend
via the highly optimized OpenBLAS library. DiffSharp currently uses operator
overloading, but we are developing a transformation-based version of the
library using F#'s "code quotation" metaprogramming facility. Work on a
CUDA-based GPU backend is also underway.


title: Deciding Hedged Bisimilarity

abstract:
  The spi-calculus is a formal model for the design and analysis of
cryptographic protocols: many security properties, such as authentication and
strong confidentiality, can be reduced to the verification of behavioural
equivalences between spi processes. In this paper we provide an algorithm for
deciding hedged bisimilarity on finite processes, which is equivalent to barbed
equivalence (and coarser than framed bisimilarity). This algorithm works with
any term equivalence satisfying a simple set of conditions, thus encompassing
many different encryption schemata.


title:
A battery-resistor analogy for further insights on measurement
  uncertainties

abstract:
  We use analogies to give introductory laboratory students intuition about
measurement uncertainties. Using a battery-resistor circuit we discuss
uncertainty concepts and derive expressions for uncertainty of the mean and
sums of uncertainties. Finally, we draw attention to the fact that the
interpretation of standard deviation as uncertainty depends on the statistical
distribution of the data, while the interpretation of uncertainty of the mean
is largely insensitive to such distribution, especially for large samples. If
the resistor in the battery-resistor circuit is a resistive loudspeaker, the
uncertainty or noise is literally the acoustic power of the sound produced by
such noise. In the sound analogy the statistical distribution of the noise is
related to its timbre.


title:
Why is it Difficult to Detect Sudden and Unexpected Epidemic Outbreaks
  in Twitter?

abstract:
  Social media services such as Twitter are a valuable source of information
for decision support systems. Many studies have shown that this also holds for
the medical domain, where Twitter is considered a viable tool for public health
officials to sift through relevant information for the early detection,
management, and control of epidemic outbreaks. This is possible due to the
inherent capability of social media services to transmit information faster
than traditional channels. However, the majority of current studies have
limited their scope to the detection of common and seasonal health recurring
events (e.g., Influenza-like Illness), partially due to the noisy nature of
Twitter data, which makes outbreak detection and management very challenging.
  Within the European project M-Eco, we developed a Twitter-based Epidemic
Intelligence (EI) system, which is designed to also handle a more general class
of unexpected and aperiodic outbreaks. In particular, we faced three main
research challenges in this endeavor:
  1) dynamic classification to manage terminology evolution of Twitter
messages, 2) alert generation to produce reliable outbreak alerts analyzing the
(noisy) tweet time series, and 3) ranking and recommendation to support domain
experts for better assessment of the generated alerts.
  In this paper, we empirically evaluate our proposed approach to these
challenges using real-world outbreak datasets and a large collection of tweets.
We validate our solution with domain experts, describe our experiences, and
give a more realistic view on the benefits and issues of analyzing social media
for public health.


abstract:
  This paper presents a novel multitask multiple kernel learning framework that
efficiently learns the kernel weights leveraging the relationship across
multiple tasks. The idea is to automatically infer this task relationship in
the \textit{RKHS} space corresponding to the given base kernels. The problem is
formulated as a regularization-based approach called \textit{Multi-Task
Multiple Kernel Relationship Learning} (\textit{MK-MTRL}), which models the
task relationship matrix from the weights learned from latent feature spaces of
task-specific base kernels. Unlike in previous work, the proposed formulation
allows one to incorporate prior knowledge for simultaneously learning several
related tasks. We propose an alternating minimization algorithm to learn the
model parameters, kernel weights and task relationship matrix. In order to
tackle large-scale problems, we further propose a two-stage \textit{MK-MTRL}
online learning algorithm and show that it significantly reduces the
computational time, and also achieves performance comparable to that of the
joint learning framework. Experimental results on benchmark datasets show that
the proposed formulations outperform several state-of-the-art multitask
learning methods.


title: Beam model for the elastic properties of material with spherical voids

abstract:
  The elastic properties of a material with spherical voids of equal volume are
analysed using a new model, with particular attention paid to the hexagonal
close-packed and the face-centred cubic arrangement of voids. Void fractions
well above 74 \% are considered, yielding overlapping voids as in an open-cell
foam and hence a connected pore structure. The material is represented by a
network of beams. The elastic behaviour of each beam is derived analytically
from the material structure. By computing the linear elastic properties of the
beam network, the Young's moduli and Poisson ratios for different directions
are evaluated. In the limit of rigidity loss a power law is obtained,
describing the relation between Young's modulus and void fraction with an
exponent of 5/2 for bending-dominated and 3/2 for stretching-dominated
directions. The corresponding Poisson ratios vary between 0 and 1. With
decreasing void fraction, these exponents become 2.3 and 1.3, respectively. The
data obtained analytically and from the new beam model are compared to Finite
Element simulations carried out in a companion study, and good agreement is
found. The hexagonal close-packed void arrangement features very anisotropic
behaviour, comparable to that of fibre-reinforced materials, This might allow
for new applications of open-cell materials.


title:
Evolving the Incremental {\lambda} Calculus into a Model of Forward
  Automatic Differentiation (AD)

abstract:
  Formal transformations somehow resembling the usual derivative are
surprisingly common in computer science, with two notable examples being
derivatives of regular expressions and derivatives of types. A newcomer to this
list is the incremental $\lambda$-calculus, or ILC, a "theory of changes" that
deploys a formal apparatus allowing the automatic generation of efficient
update functions which perform incremental computation. The ILC is not only
defined, but given a formal machine-understandable definition---accompanied by
mechanically verifiable proofs of various properties, including in particular
correctness of various sorts. Here, we show how the ILC can be mutated into
propagating tangents, thus serving as a model of Forward Accumulation Mode
Automatic Differentiation. This mutation is done in several steps. These steps
can also be applied to the proofs, resulting in machine-checked proofs of the
correctness of this model of forward AD.


title: Beyond superfluidity in driven non-equilibrium Bose-Einstein condensates

abstract:
  The phenomenon of superfluidity in open Bose-Einstein condensates (BEC) is
analysed numerically and analytically. It is found that a superfluid phase is
feasible even above the speed of sound, when forces due to inhomogeneous
non-equilibrium processes oppose the contributions of homogeneous processes.
Furthermore a regime of accelerating impurities can be observed for particular
pumping/decay strategies. All findings are derived within the complex
Gross-Pitaevskii (GP) theory with creation and annihilation terms. Utilising
this framework the effective force acting on an impurity as it moves with
velocity v through the open condensate can be calculated. The result shows that
the force is continuously increasing/decreasing with increasing velocity
starting from the state of zero motion at v = 0, a property that can be traced
down to the additional homogeneous annihilation/creation term in the extended
GP model. Our findings stand in stark contrast to the concept of a topological
phase transition to frictionless flow below a critical velocity as observed for
equilibrium Bose-Einstein condensates analytically, numerically and for trapped
atoms experimentally.


title: Bounding Hilbert coefficients of parameter ideals

abstract:
  Let $(R,\mathfrak{m})$ be a Noetherian local ring of dimension $d>0$ and
depth R$\geq d-1$. Let $Q$ be a parameter ideal of $R$. In this paper, we
derive uniform lower and upper bounds for the Hilbert coefficient $e_i(Q)$
under certain assumptions on the depth of associated graded ring $G(Q)$. For
$2\leq i\leq d $, we show that (1) $e_i(Q)\leq 0$ provided depth $G(Q)\geq d-2$
and (2) $e_i(Q)\geq -\lambda_R(H_{\mathfrak{m}}^{d-1}(R))$ provided depth
$G(Q)\geq d-1$. It is proved that $e_3(Q)\leq 0$. Further, we obtain a
necessary condition for the vanishing of the last coefficient $e_d(Q)$. As a
consequence, we characterize the vanishing of $e_2(Q)$. Our results generalize
\cite[Theorem 3.2]{goto-ozeki} and \cite[Corollary 4.5]{Lori}.


title: Noise-induced chimera states in a neural network

abstract:
  We show that chimera patterns can be induced by noise in nonlocally coupled
neural networks in the excitable regime. In contrast to classical chimeras,
occurring in noise-free oscillatory networks, they have features of two
phenomena: coherence resonance and chimera states. Therefore, we call them
coherence-resonance chimeras. These patterns demonstrate the constructive role
of noise and appear for intermediate values of noise intensity, which is a
characteristic feature of coherence resonance. In the coherence-resonance
chimera state a neural network of identical elements splits into two coexisting
domains with different behavior: spatially coherent and spatially incoherent, a
typical property of chimera states. Moreover, these noise-induced chimera
states are characterized by alternating behavior: coherent and incoherent
domains switch periodically their location. We show that this alternating
switching can be explained by analyzing the coupling functions.


title: Top Signatures From Composite Higgs Theories

abstract:
  Many compelling theories to address the Higgs hierarchy problem predict
strong interactions between the top and a sector of New Physics. In minimal
composite Higgs models (CHM), the top interactions with a BSM
strongly-interacting sector give the leading contribution to trigger the EWSB
and generate a light mass for the pseudo-NG Higgs. This implies that new
composite states (vector-like top-partners, composite vector resonances, new
composite scalars) dominantly interact with third-generation quarks and, when
produced at colliders, generate top quarks in the final state. I will indicate
interesting signatures involving top quarks for CHM discovery/test at the LHC
and future colliders.


title: A curious differential calculus on the quantum disc and cones

abstract:
  A non-classical differential calculus on the quantum disc and cones is
constructed and the associated integral is calculated.


title:
Optimal Trade Execution with Instantaneous Price Impact and Stochastic
  Resilience

abstract:
  We study an optimal execution problem in illiquid markets with both
instantaneous and persistent price impact and stochastic resilience when only
absolutely continuous trading strategies are admissible. In our model the value
function can be described by a three-dimensional system of backward stochastic
differential equations (BSDE) with a singular terminal condition in one
component. We prove existence and uniqueness of a solution to the BSDE system
and characterize both the value function and the optimal strategy in terms of
the unique solution to the BSDE system. Our existence proof is based on an
asymptotic expansion of the BSDE system at the terminal time that allows us to
express the system in terms of a equivalent system with finite terminal value
but singular driver.