title: A quantum bound on the thermodynamic description of gravity

abstract:
  The seminal works of Bekenstein and Hawking have revealed that black holes
have a well-defined thermodynamic description. In particular, it is often
stated in the physical literature that black holes, like mundane physical
systems, obey the first law of thermodynamics: $\Delta S=\Delta
E/T_{\text{BH}}$, where $T_{\text{BH}}$ is the Bekenstein-Hawking temperature
of the black hole. In the present work we test the regime of validity of the
thermodynamic description of gravity. In particular, we provide compelling
evidence that, due to quantum effects, the first law of thermodynamics breaks
down in the low-temperature regime $T_{\text{BH}}\times r_{\text{H}}\lesssim
({{\hbar}/{r_{\text{H}}}})^2$ of near-extremal black holes (here $r_{\text{H}}$
is the radius of the black-hole horizon).


title:
Detecting and Tracking The Real-time Hot Topics: A Study on
  Computational Neuroscience

abstract:
  In this study, following the idea of our previous paper (Wang, et al.,
2013a), we improve the method to detect and track hot topics in a specific
field by using the real-time article usage data. With the "usage count" data
provided by Web of Science, we take the field of computational neuroscience as
an example to make analysis. About 10 thousand articles in the field of
Computational Neuroscience are queried in Web of Science, when the records,
including the usage count data of each paper, have been harvested and updated
weekly from October 19, 2015 to March 21, 2016. The hot topics are defined by
the most frequently used keywords aggregated from the articles. The analysis
reveals that hot topics in Computational Neuroscience are related to the key
technologies, like "fmri", "eeg", "erp", etc. Furthermore, using the weekly
updated data, we track the dynamical changes of the topics. The characteristic
of immediacy of usage data makes it possible to track the "heat" of hot topics
timely and dynamically.


title: On the Existence of a Projective Reconstruction

abstract:
  In this note we study the connection between the existence of a projective
reconstruction and the existence of a fundamental matrix satisfying the
epipolar constraints.


title: Electromagnetic Boundaries with PEC/PMC Equivalence

abstract:
  The most general electromagnetic boundary, defined by linear and local
boundary conditions, is defined in terms of conditions which can be called
generalized impedance boundary conditions. Requiring that the boundary be
equivalent to PEC and PMC boundaries for its two eigen-plane waves, which
property is known to exist for many of its special cases, it is shown that the
recently introduced Generalized Soft-and-Hard/DB (GSHDB) boundary is the most
general boundary satisfying this property.


title:
The IACOB project: IV. New predictions for high-degree non-radial mode
  instability domains in massive stars and connection with macroturbulent
  broadening

abstract:
  Asteroseismology is a powerful tool to access the internal structure of
stars. Apart from the important impact of theoretical developments, progress in
this field has been commonly associated with the analysis of time-resolved
observations. Recently, the so-called macroturbulent broadening has been
proposed to be a complementary and less expensive way -- in terms of
observational time -- to investigate pulsations in massive stars. We assess to
what extent this ubiquitous non-rotational broadening component shaping the
line profiles of O stars and B supergiants is a spectroscopic signature of
pulsation modes driven by a heat mechanism. We compute stellar main sequence
and post-main sequence models from 3 to 70Msun with the ATON stellar evolution
code and determine the instability domains for heat-driven modes for degrees
l=1-20 using the adiabatic and non-adiabatic codes LOSC and MAD. We use the
observational material presented in Sim\'on-D\'iaz et al. (2016) to investigate
possible correlations between the single snapshot line-broadening properties of
a sample of ~260 O and B-type stars and their location inside/outside the
various predicted instability domains. We present an homogeneous prediction for
the non-radial instability domains of massive stars for degree l up to 20. We
provide a global picture of what to expect from an observational point of view
in terms of frequency range of excited modes, and investigate the behavior of
the instabilities with stellar evolution and increasing degree of the mode.
Furthermore, our pulsational stability analysis, once compared to the empirical
results of Sim\'on-D\'iaz et al. (2016), indicates that stellar oscillations
originated by a heat mechanism can not explain alone the occurrence of the
large non-rotational line-broadening component commonly detected in the O star
and B supergiant domain.


title: Towards Reversible Computation in Erlang

abstract:
  In a reversible language, any forward computation can be undone by a finite
sequence of backward steps. Reversible computing has been studied in the
context of different programming languages and formalisms, where it has been
used for debugging and for enforcing fault-tolerance, among others. In this
paper, we consider a subset of Erlang, a concurrent language based on the actor
model. We formally introduce a reversible semantics for this language. To the
best of our knowledge, this is the first attempt to define a reversible
semantics for Erlang.


title:
Revisiting enumerative two-part crude MDL for Bernoulli and multinomial
  distributions (Extended version)

abstract:
  We leverage the Minimum Description Length (MDL) principle as a model
selection technique for Bernoulli distributions and compare several types of
MDL codes. We first present a simplistic crude two-part MDL code and a
Normalized Maximum Likelihood (NML) code. We then focus on the enumerative
two-part crude MDL code, suggest a Bayesian interpretation for finite size data
samples, and exhibit a strong connection with the NML approach. We obtain
surprising impacts on the estimation of the model complexity together with
superior compression performance. This is then generalized to the case of the
multinomial distributions. Both the theoretical analysis and the experimental
comparisons suggest that one might use the enumerative code rather than NML in
practice, for Bernoulli and multinomial distributions.


title:
Mollow triplet: pump probe single photon spectroscopy of artificial
  atoms

abstract:
  We analyze a photon transport through an 1D open waveguide side coupled to
the $N$-photon microwave cavity with embedded artificial two- level atom
(qubit). The qubit state is probed by a weak signal at the fundamental
frequency of the waveguide. Within the formalism of projection operators and
non-Hermitian Hamiltonian approach we develop a one-photon approximation scheme
to obtain the photon wavefunction which allows for the calculation of the
probability amplitudes of the spontaneous transitions between the levels of two
Rabi doublets in $N$- photon cavity. We obtain analytic expressions for the
transmission and reflection factors of the microwave signal through a
waveguide, which contain the information of the qubit parameters. We show that
for small number of cavity photons the Mollow spectrum consists of four
spectral lines which is a direct manifestation of quantum nature of light. The
results obtained in the paper are of general nature and can be applied to any
type of qubits. The specific properties of the qubit are only encoded in the
two parameters: the energy $\Omega$ of the qubit and its coupling $\lambda$ to
the cavity photons.


title: Approximate injectivity

abstract:
  In a locally $\lambda$-presentable category, with $\lambda$ a regular
cardinal, classes of objects that are injective with respect to a family of
morphisms whose domains and codomains are $\lambda$-presentable, are known to
be characterized by their closure under products, $\lambda$-directed colimits
and $\lambda$-pure subobjects. Replacing the strict commutativity of diagrams
by "commutativity up to $\varepsilon$", this paper provides an "approximate
version" of this characterization for categories enriched over metric spaces.
It entails a detailed discussion of the needed $\varepsilon$-generalizations of
the notion of $\lambda$-purity. The categorical theory is being applied to the
locally $\aleph_1$-presentable category of Banach spaces and their linear
operators of norm at most 1, culminating in a largely categorical proof for the
existence of the so-called Gurarii Banach space.


title:
Higher dimensional twisted Alexander polynomials for metabelian
  representations

abstract:
  We study the asymptotic behavior of the twisted Alexander polynomial for the
sequence of SL(n ,C)-representations induced from an irreducible metabelian
SL(2, C)-representation of a knot group. We give the limits of the leading
coefficients in the asymptotics of the twisted Alexander polynomial and related
Reidemeister torsion. The concrete computations for all genus one two-bridge
knots are also presented.


title:
Galaxy And Mass Assembly (GAMA): the Stellar Mass Budget of Galaxy
  Spheroids and Disks

abstract:
  We build on a recent photometric decomposition analysis of 7506 Galaxy and
Mass Assembly (GAMA) survey galaxies to derive stellar mass function fits to
individual spheroid and disk component populations down to a lower mass limit
of log(M_*/M_sun)= 8. We find that the spheroid/disk mass distributions for
individual galaxy morphological types are well described by single Schechter
function forms. We derive estimates of the total stellar mass densities in
spheroids (rho_spheroid = 1.24+/-0.49 * 10^8 M_sun Mpc^-3 h_0.7) and disks
(rho_disk = 1.20+/-0.45 * 10^8 M_sun Mpc^-3 h_0.7), which translates to
approximately 50% of the local stellar mass density in spheroids and 48% in
disks. The remaining stellar mass is found in the dwarf "little blue spheroid"
class, which is not obviously similar in structure to either classical spheroid
or disk populations. We also examine the variation of component mass ratios
across galaxy mass and group halo mass regimes, finding the transition from
spheroid to disk mass dominance occurs near galaxy stellar mass ~10^11 M_sun
and group halo mass ~10^12.5 M_sun/h. We further quantify the variation in
spheroid-to-total mass ratio with group halo mass for central and satellite
populations as well as the radial variation of this ratio within groups.


title: Boundary-layer turbulence in experiments of quasi-Keplerian flows

abstract:
  Most flows in nature and engineering are turbulent because of their large
velocities and spatial scales. Laboratory experiments of rotating
quasi-Keplerian flows, for which the angular velocity decreases radially but
the angular momentum increases, are however laminar at Reynolds numbers
exceeding one million. This is in apparent contradiction to direct numerical
simulations showing that in these experiments turbulence transition is
triggered by the axial boundaries. We here show numerically that as the
Reynolds number increases turbulence becomes progressively confined to the
boundary layers and the flow in the bulk fully relaminarizes. Our findings
support that turbulence is unlikely to occur in isothermal constant density
quasi-Keplerian flows.


title:
Automatic Selection of Context Configurations for Improved
  Class-Specific Word Representations

abstract:
  This paper is concerned with identifying contexts useful for training word
representation models for different word classes such as adjectives (A), verbs
(V), and nouns (N). We introduce a simple yet effective framework for an
automatic selection of class-specific context configurations. We construct a
context configuration space based on universal dependency relations between
words, and efficiently search this space with an adapted beam search algorithm.
In word similarity tasks for each word class, we show that our framework is
both effective and efficient. Particularly, it improves the Spearman's rho
correlation with human scores on SimLex-999 over the best previously proposed
class-specific contexts by 6 (A), 6 (V) and 5 (N) rho points. With our selected
context configurations, we train on only 14% (A), 26.2% (V), and 33.6% (N) of
all dependency-based contexts, resulting in a reduced training time. Our
results generalise: we show that the configurations our algorithm learns for
one English training setup outperform previously proposed context types in
another training setup for English. Moreover, basing the configuration space on
universal dependencies, it is possible to transfer the learned configurations
to German and Italian. We also demonstrate improved per-class results over
other context types in these two languages.


title:
Acoustic one-way mode conversion and transmission by sonic crystal
  waveguides

abstract:
  We proposed a scheme to achieve one-way acoustic propagation and even odd
mode switching in two mutually perpendicular sonic crystal waveguides connected
by a resonant cavity. The even mode in the entrance waveguide is able to switch
to odd mode in the exit waveguide through a symmetry match between the cavity
resonant modes and the waveguide modes. Conversely, the odd mode in the exit
waveguide is unable to be converted into the even mode in the entrance
waveguide as incident waves and eigenmodes are mismatched in their symmetries
at the waveguide exit. This one way mechanism can be applied to design an
acoustic diode for acoustic integration devices and can be used as a convertor
of the acoustic waveguide modes.


title:
Generalized Module Extension Banach Algebras: Derivations and Weak
  Amenability

abstract:
  Let $A$ and $X$ be Banach algebras and let $X$ be an algebraic Banach
$A-$module. Then the $\ell^1-$direct sum $A\times X$ equipped with the
multiplication $$(a,x)(b,y)=(ab, ay+xb+xy)\quad (a,b\in A, x,y\in X)$$ is a
Banach algebra, denoted by $A\bowtie X$, which will be called "\textit{a
generalized module extension Banach algebra}". Module extension algebras, Lau
product and also the direct sum of Banach algebras are the main examples
satisfying this framework. We characterize the structure of $n-$dual valued
($n\in\mathbb N)$) derivations on $A\bowtie X$ from which we investigate the
$n-$weak amenability for the algebra $A\bowtie X.$ We apply the results and the
techniques of proofs for presenting some older results with simple direct
proofs.


title:
Weyl nodes as topological defects of the Wannier-Stark ladder: From
  surface to bulk Fermi arcs

abstract:
  A hallmark of Weyl semimetal is the existence of surface Fermi arcs
connecting two surface-projected Weyl nodes with opposite chiralities. An
intriguing question is what determines the connectivity of surface Fermi arcs,
when multiple pairs of Weyl nodes are present. To answer this question, we
first show that the locations of surface Fermi arcs are predominantly
determined by the condition that the Zak phase integrated along the normal
direction to the surface is $\pi$. More importantly, the Zak phase can reveal
the peculiar topological structure of Weyl semimetal directly in the bulk.
Here, we show that the non-trivial winding of the Zak phase around each
projected Weyl node manifests itself as a topological defect of the
Wannier-Stark ladder, the energy eigenstates emerging under an electric field.
Remarkably, this structure leads to "bulk Fermi arcs," i.e., open line segments
in the bulk momentum spectra. It is argued that bulk Fermi arcs should exist in
conjunction with the surface counterparts to conserve the Weyl fermion number
under an electric field, which is supported by explicit numerical evidence.


title: Applications of model theory to C*-dynamics

abstract:
  We initiate the study of compact group actions on C*-algebras from the
perspective of model theory, and present several applications to C*-dynamics.
Firstly, we prove that the continuous part of the central sequence algebra of a
strongly self-absorbing action is indistinguishable from the continuous part of
the sequence algebra, and in fact equivariantly isomorphic under the Continuum
Hypothesis. As another application, we present a unified approach to several
dimensional inequalities in C*-algebras, which is done through the notion of
order zero dimension for an (equivariant) *-homomorphism. Finiteness of the
order zero dimension implies that the dimension of the target algebra can be
bounded by the dimension of the domain. The dimension can be, among others,
decomposition rank, nuclear dimension, or Rokhlin dimension. As a consequence,
we obtain new inequalities for these quantities.
  As a third application we obtain the following result: if a C*-algebra $A$
absorbs a strongly self-absorbing C*-algebra $D$, and $\alpha $ is an action of
a compact group $G$ on $A$ with finite Rokhlin dimension with commuting towers,
then $\alpha $ absorbs any strongly self-absorbing action of $G$ on $% D$. This
has a number of interesting consequences, already in the case of the trivial
action on $D$. For example, we deduce that $D$-stability passes from $A$ to the
crossed product. Additionally, in many cases of interest, our result restricts
the possible values of the Rokhlin dimension to $0, 1$ and $\infty$, showing a
striking parallel to the behavior of the nuclear dimension for simple
C*-algebras. We also show that an action of a finite group with finite Rokhlin
dimension with commuting towers automatically has the Rokhlin property if the
algebra is UHF-absorbing.


title:
Joint Estimation of Sparse Networks with application to Paired Gene
  Expression data

abstract:
  We consider a method to jointly estimate sparse precision matrices and their
underlying graph structures using dependent high-dimensional datasets. We
present a penalized maximum likelihood estimator which encourages both sparsity
and similarity in the estimated precision matrices where tuning parameters are
automatically selected by controlling the expected number of false positive
edges. We also incorporate an extra step to remove edges which represent an
overestimation of triangular motifs. We conduct a simulation study to show that
the proposed methodology presents consistent results for different combinations
of sample size and dimension. Then, we apply the suggested approaches to a
high-dimensional real case study of gene expression data with samples in two
medical conditions, healthy and colon cancer tissues, to estimate a common
network of genes as well as the differentially connected genes that are
important to the disease. We find denser graph structures for healthy samples
than for tumor samples, with groups of genes interacting together in the shape
of clusters.


title: $T \bar{T}$-deformed 2D Quantum Field Theories

abstract:
  It was noticed many years ago, in the framework of massless RG flows, that
the irrelevant composite operator $T \bar{T}$, built with the components of the
energy-momentum tensor, enjoys very special properties in 2D quantum field
theories, and can be regarded as a peculiar kind of integrable perturbation.
Novel interesting features of this operator have recently emerged from the
study of effective string theory models.In this paper we study further
properties of this distinguished perturbation. We discuss how it affects the
energy levels and one-point functions of a general 2D QFT in finite volume
through a surprising relation with a simple hydrodynamic equation. In the case
of the perturbation of CFTs, adapting a result by L\"uscher and Weisz we give a
compact expression for the partition function on a finite-length cylinder and
make a connection with the exact $g$-function method. We argue that, at the
classical level, the deformation naturally maps the action of $N$ massless free
bosons into the Nambu-Goto action in static gauge, in $N+2$ target space
dimensions, and we briefly discuss a possible interpretation of this result in
the context of effective string models.


title:
Recurrence in the dynamical system $(X,\langle T_s\rangle_{s\in S})$ and
  ideals of $\beta S$

abstract:
  A {\it dynamical system\/} is a pair $(X,\langle T_s\rangle_{s\in S})$, where
$X$ is a compact Hausdorff space, $S$ is a semigroup, for each $s\in S$, $T_s$
is a continuous function from $X$ to $X$, and for all $s,t\in S$, $T_s\circ
T_t=T_{st}$. Given a point $p\in\beta S$, the Stone-\v Cech compactification of
the discrete space $S$, $T_p:X\to X$ is defined by, for $x\in X$,
$\displaystyle T_p(x)=p{-}\!\lim_{s\in S}T_s(x)$. We let $\beta S$ have the
operation extending the operation of $S$ such that $\beta S$ is a right
topological semigroup and multiplication on the left by any point of $S$ is
continuous. Given $p,q\in\beta S$, $T_p\circ T_q=T_{pq}$, but $T_p$ is usually
not continuous. Given a dynamical system $(X,\langle T_s\rangle_{s\in S})$, and
a point $x\in X$, we let $U(x)=\{p\in\beta S:T_p(x)$ is uniformly
recurrent$\}$. We show that each $U(x)$ is a left ideal of $\beta S$ and for
any semigroup we can get a dynamical system with respect to which $K(\beta
S)=\bigcap_{x\in X}U(x)$ and $c\ell K(\beta S)=\bigcap\{U(x):x\in X$ and $U(x)$
is closed$\}$. And we show that weak cancellation assumptions guarantee that
each such $U(x)$ properly contains $K(\beta S)$ and has $U(x) \setminus c\ell
K(\beta S)\neq \emptyset$.


title:
Measuring coronal magnetic fields with remote sensing observations of
  shock waves

abstract:
  Recent works demonstrated that remote sensing observations of shock waves
propagating into the corona and associated with major solar eruptions can be
used to derive the strength of coronal magnetic fields met by the shock over a
very large interval of heliocentric distances and latitudes. This opinion
article will summarize most recent results obtained on this topic and will
discuss the weaknesses and strengths of these techniques to open a constructive
discussion with the scientific community.


title: Private and Truthful Aggregative Game for Large-Scale Spectrum Sharing

abstract:
  Thanks to the rapid development of information technology, the size of the
wireless network becomes larger and larger, which makes spectrum resources more
precious than ever before. To improve the efficiency of spectrum utilization,
game theory has been applied to study the spectrum sharing in wireless networks
for a long time. However, the scale of wireless network in existing studies is
relatively small. In this paper, we introduce a novel game and model the
spectrum sharing problem as an aggregative game for large-scale, heterogeneous,
and dynamic networks. The massive usage of spectrum also leads to easier
privacy divulgence of spectrum users' actions, which calls for privacy and
truthfulness guarantees in wireless network. In a large decentralized scenario,
each user has no priori about other users' decisions, which forms an incomplete
information game. A "weak mediator", e.g., the base station or licensed
spectrum regulator, is introduced and turns this game into a complete one,
which is essential to reach a Nash equilibrium (NE). By utilizing past
experience on the channel access, we propose an online learning algorithm to
improve the utility of each user, achieving NE over time. Our learning
algorithm also provides no regret guarantee to each user. Our mechanism admits
an approximate ex-post NE. We also prove that it satisfies the joint
differential privacy and is incentive-compatible. Efficiency of the approximate
NE is evaluated, and the innovative scaling law results are disclosed. Finally,
we provide simulation results to verify our analysis.


title: A Survey on Routing in Anonymous Communication Protocols

abstract:
  The Internet has undergone dramatic changes in the past 15 years, and now
forms a global communication platform that billions of users rely on for their
daily activities. While this transformation has brought tremendous benefits to
society, it has also created new threats to online privacy, ranging from
profiling of users for monetizing personal information to nearly omnipotent
governmental surveillance. As a result, public interest in systems for
anonymous communication has drastically increased. Several such systems have
been proposed in the literature, each of which offers anonymity guarantees in
different scenarios and under different assumptions, reflecting the plurality
of approaches for how messages can be anonymously routed to their destination.
Understanding this space of competing approaches with their different
guarantees and assumptions is vital for users to understand the consequences of
different design options.
  In this work, we survey previous research on designing, developing, and
deploying systems for anonymous communication. To this end, we provide a
taxonomy for clustering all prevalently considered approaches (including
Mixnets, DC-nets, onion routing, and DHT-based protocols) with respect to their
unique routing characteristics, deployability, and performance. This, in
particular, encompasses the topological structure of the underlying network;
the routing information that has to be made available to the initiator of the
conversation; the underlying communication model; and performance-related
indicators such as latency and communication layer. Our taxonomy and
comparative assessment provide important insights about the differences between
the existing classes of anonymous communication protocols, and it also helps to
clarify the relationship between the routing characteristics of these
protocols, and their performance and scalability.


title: Self-gravitating disc candidates around massive young stars

abstract:
  There have been several recent detections of candidate Keplerian discs around
massive young protostars. Given the relatively large disc-to-star mass ratios
in these systems, and their young ages, it is worth investigating their
propensity to becoming self-gravitating. To this end, we compute
self-consistent, semi-analytic models of putative self-gravitating discs for
five candidate disc systems. Our aim is not to fit exactly the observations,
but to demonstrate that the expected dust continuum emission from marginally
unstable self-gravitating discs can be quite weak, due to high optical depth at
the midplane even at millimetre wavelengths. In the best cases, the models
produce "observable" disc masses within a factor of <1.5 of those observed,
with midplane dust temperatures comparable to measured temperatures from
molecular line emission. We find in two cases that a self-gravitating disc
model compares well with observations. If these discs are self-gravitating,
they satisfy the conditions for disc fragmentation in their outer regions.
These systems may hence have as-yet-unresolved low mass stellar companions, and
are thus promising targets for future high angular resolution observations.


title:
Ergodic attractors and almost-everywhere asymptotics of scalar
  semilinear parabolic differential equations

abstract:
  We consider dynamics of scalar semilinear parabolic equations on bounded
intervals with periodic boundary conditions, and on the entire real line, with
a general nonlinearity $g(t,x,u,u_x)$ either not depending on $t$, or periodic
in $t$. While the topological and geometric structure of their attractors has
been investigated in depth, we focus here on ergodic-theoretical properties.
The main result is that the union of supports of all the invariant measures
projects one-to-one to $\mathbb{R}^2$. We rely on a novel application of the
zero-number techniques with respect to evolution of measures on the phase
space, and on properties of the flux of zeroes, and the dissipation of zeroes.
As an example of an application, we prove uniqueness of an invariant measure
for a large family of considered equations which conserve a certain quantity
("mass"), thus generalizing the results by Sinai for the scalar viscous Burgers
equation.


title: Complex Legendre duality

abstract:
  We introduce complex generalizations of the classical Legendre transform,
operating on K\"ahler metrics on a compact complex manifold. These Legendre
transforms give explicit local isometric symmetries for the Mabuchi metric on
the space of K\"ahler metrics around any real analytic K\"ahler metric,
answering a question originating in Semmes' work.


title: Chern forms of singular metrics on vector bundles

abstract:
  We study singular hermitian metrics on holomorphic vector bundles, following
Berndtsson-P{\u{a}}un. Previous work by Raufi has shown that for such metrics,
it is in general not possible to define the curvature as a current with measure
coefficients. In this paper we show that despite this, under appropriate
codimension restrictions on the singular set of the metric, it is still
possible to define Chern forms as closed currents of order 0 with locally
finite mass, which represent the Chern classes of the vector bundle.


title:
Uncertainty Principle for Measurable Sets and Signal Recovery in
  Quaternion Domains

abstract:
  The classical uncertainty principle of harmonic analysis states that a
nontrivial function and its Fourier transform cannot both be sharply localized.
It plays an important role in signal processing and physics. This paper
generalizes the uncertainty principle for measurable sets from complex domain
to hypercomplex domain using quaternion algebras, associated with the
Quaternion Fourier transform. The performance is then evaluated in signal
recovery problems where there is an interplay of missing and time-limiting
data.


title:
Multivariate Lucas Polynomials and Ideal Classes in Quadratic Number
  Fields

abstract:
  In this work, by using Pauli matrices, we introduce four families of
polynomials indexed over the positive integers. These polynomials have rational
or imaginary rational coefficients. It turns out that two of these families are
closely related to classical Lucas and Fibonacci polynomial sequences and hence
to Lucas and Fibonacci numbers. We use one of these families to give a
geometric interpretation of the 200 years old class number problems of Gauss,
which is equivalent to the study of narrow ideal classes in real quadratic
number fields.


title:
Higher harmonic anisotropic flow of identified particles in Pb-Pb
  collisions with the ALICE detector

abstract:
  Anisotropic flow plays a crucial role in establishing the equation of state
of the Quark Gluon Plasma. The results at RHIC and LHC have demonstrated that
the matter created in heavy-ion collisions behaves as a nearly perfect fluid
reflected in the low value of the shear viscosity over entropy density ratio
($\eta/s$). The higher flow harmonics are particularly sensitive to the value
of $\eta/s$ in hydrodynamic calculations. In this analysis, we present the
first ALICE results on the $p_{\mathrm{T}}$ differential $v_{2}$, $v_{3}$ and
$v_{4}$ for $\pi^{\pm}$, $\mathrm{K}^{\pm}$, p($\bar p$) from the high
statistics 2011 heavy-ion run. We investigate how these $v_{n}$ coefficients
evolve with particle mass and centrality for the 0--1\% and 20--30\% centrality
ranges. These new measurements aim at differentiating between models that use
different initial conditions, constraining further the value of $\eta/s$ and
allowing to decouple the influence of the late hadronic stage from the
hydrodynamic evolution of the system.


title: In-depth study of 16CygB using inversion techniques

abstract:
  The 16Cyg binary system hosts the solar-like Kepler targets with the most
stringent observational constraints. Moreover, this system is particularly
interesting since both stars are very similar in mass but the A component is
orbited by a red dwarf, whereas the B component is orbited by a Jovian planet
and thus could have formed a more complex planetary system. In our previous
study, we showed that seismic inversions of integrated quantities could be used
to constrain microscopic diffusion in the A component. In this study, we
analyse the B component in the light of a more regularised inversion. We wish
to analyse independently the B component of the 16Cyg binary system using the
inversion of an indicator dedicated to analyse core conditions, denoted tu.
Using this independent determination, we wish to analyse any differences
between both stars due to the potential influence of planetary formation on
stellar structure and/or their respective evolution. First, we recall the
observational constraints for 16CygB and the method we used to generate
reference stellar models. The inversion results were then used to analyse the
differences between the A and B components. The tu indicator for 16CygB shows a
disagreement with models including microscopic diffusion and sharing the
chemical composition previously derived for 16CygA. Small changes in chemical
composition are insufficient to solve the problem but that extra mixing can
account for the differences seen between both stars. We use a parametric
approach to analyse the impact of extra mixing in the form of turbulent
diffusion on the behaviour of the tu values. We conclude on the necessity of
further investigations using models with a physically motivated implementation
of extra mixing including additional constraints to further improve the
accuracy with which the fundamental parameters of this system are determined.


title: Minimal Entanglement Witness From Electrical Current Correlations

abstract:
  Despite great efforts, an unambiguous demonstration of entanglement of mobile
electrons in solid state conductors is still lacking. Investigating
theoretically a generic entangler-detector setup, we here show that a witness
of entanglement between two flying electron qubits can be constructed from only
two current cross correlation measurements, for any nonzero detector
efficiencies and non-collinear polarization vectors. We find that all entangled
pure states, but not all mixed ones, can be detected with only two
measurements, except the maximally entangled states, which require three.
Moreover, detector settings for optimal entanglement witnessing are presented.


title: Goal-Oriented Reduction of Automata Networks

abstract:
  We consider networks of finite-state machines having local transitions
conditioned by the current state of other automata. In this paper, we depict a
reduction procedure tailored for a given reachability property of the form
``from global state s there exists a sequence of transitions leading to a state
where an automaton g is in a local state T'. By exploiting a causality analysis
of the transitions within the individual automata, the proposed reduction
removes local transitions while preserving all the minimal traces that satisfy
the reachability property. The complexity of the procedure is polynomial in the
total number of local states and transitions, and exponential in the number of
local states within one automaton. Applied to automata networks modelling
dynamics of biological systems, we observe that the reduction shrinks down
significantly the reachable state space, enhancing the tractability of the
model-checking of large networks.


title: Where does the gas fueling star formation in BCGs originate?

abstract:
  We investigate the relationship between X-ray cooling and star formation in
brightest cluster galaxies (BCGs). We present an X-ray spectral analysis of the
inner regions, 10-40 kpc, of six nearby cool core clusters (z<0.35) observed
with Chandra ACIS. This sample is selected on the basis of the high star
formation rate (SFR) observed in the BCGs. We restrict our search for cooling
gas to regions that are roughly cospatial with the starburst. We fit single-
and multi-temperature mkcflow models to constrain the amount of isobarically
cooling intracluster medium (ICM). We find that in all clusters, below a
threshold temperature ranging between 0.9 and 3 keV, only upper limits can be
obtained. In four out of six objects, the upper limits are significantly below
the SFR and in two, namely A1835 and A1068, they are less than a tenth of the
SFR. Our results suggests that a number of mechanisms conspire to hide the
cooling signature in our spectra. In a few systems the lack of a cooling
signature may be attributed to a relatively long delay time between the X-ray
cooling and the star burst. However, for A1835 and A1068, where the X-ray
cooling time is shorter than the timescale of the starburst, a possible
explanation is that the region where gas cools out of the X-ray phase extends
to very large radii, likely beyond the core of these systems.


title: Shortest unique palindromic substring queries in optimal time

abstract:
  A palindrome is a string that reads the same forward and backward. A
palindromic substring $P$ of a string $S$ is called a shortest unique
palindromic substring ($\mathit{SUPS}$) for an interval $[x, y]$ in $S$, if $P$
occurs exactly once in $S$, this occurrence of $P$ contains interval $[x, y]$,
and every palindromic substring of $S$ which contains interval $[x, y]$ and is
shorter than $P$ occurs at least twice in $S$. The $\mathit{SUPS}$ problem is,
given a string $S$, to preprocess $S$ so that for any subsequent query interval
$[x, y]$ all the $\mathit{SUPS}\mbox{s}$ for interval $[x, y]$ can be answered
quickly. We present an optimal solution to this problem. Namely, we show how to
preprocess a given string $S$ of length $n$ in $O(n)$ time and space so that
all $\mathit{SUPS}\mbox{s}$ for any subsequent query interval can be answered
in $O(k+1)$ time, where $k$ is the number of outputs.


title:
Suppressing the cellular breakdown in silicon supersaturated with
  titanium

abstract:
  Hyper doping Si with up to 6 at.% Ti in solid solution was performed by ion
implantation followed by pulsed laser annealing and flash lamp annealing. In
both cases, the implanted Si layer can be well recrystallized by liquid phase
epitaxy and solid phase epitaxy, respectively. Cross-sectional transmission
electron microscopy of Ti-implanted Si after liquid phase epitaxy shows the
so-called growth interface breakdown or cellular breakdown owing to the
occurrence of constitutional supercooling in the melt. The appearance of
cellular breakdown prevents further recrystallization. However, the
out-diffusion and cellular breakdown can be effectively suppressed by solid
phase epitaxy during flash lamp annealing due to the high velocity of
amorphous-crystalline interface and the low diffusion velocity for Ti in the
solid phase.


title:
Relationship between the Reprogramming Determinants of Boolean Networks
  and their Interaction Graph

abstract:
  In this paper, we address the formal characterization of targets triggering
cellular trans-differentiation in the scope of Boolean networks with
asynchronous dynamics. Given two fixed points of a Boolean network, we are
interested in all the combinations of mutations which allow to switch from one
fixed point to the other, either possibly, or inevitably. In the case of
existential reachability, we prove that the set of nodes to (permanently) flip
are only and necessarily in certain connected components of the interaction
graph. In the case of inevitable reachability, we provide an algorithm to
identify a subset of possible solutions.


title:
Rock-paper-scissors played within competing domains in predator-prey
  games

abstract:
  We consider (N,r) games of predation with N species and r < N prey and
predators, acting in a cyclic way. Further basic reactions include
reproduction, decay and diffusion over a regular grid, without a hard
constraint on the occupation number per site, so in a "bosonic" implementation.
For special combinations of N and r and appropriate parameter choices we
observe games within games, that is, different coexisting games, depending on
the spatial resolution. As concrete and simplest example we analyze the (6,3)
game. Once the players segregate from a random initial distribution, domains
emerge, which effectively play a (2,1)-game on the coarse scale of domain
diameters, while agents inside the domains play (3,1) (rock-paper-scissors),
leading to spiral formation with species chasing each other. As the (2,1)-game
has a winner in the end, the coexistence of domains is transient, while agents
inside the remaining domain coexist, until demographic fluctuations lead to
extinction of all but one species in the very end. This means that we observe a
dynamical generation of multiple space and time scales with emerging
re-organization of players upon segregation, starting from a simple set of
rules on the smallest scale and changed rules from the coarser perspective.
These observations are based on Gillespie simulations. We discuss the
deterministic limit derived from a van Kampen expansion. The linear stability
analysis predicts the number of forming domains, their composition in terms of
species; it also explains the instability of interfaces between domains, which
drives their extinction; spiral patterns are identified as motion along
heteroclinic cycles. The numerical solutions reproduce the observed patterns of
the Gillespie simulations including even extinction events, so that the
mean-field analysis here is very conclusive, which is due to the specific
implementation of rules.


title: Learning to Start for Sequence to Sequence Architecture

abstract:
  The sequence to sequence architecture is widely used in the response
generation and neural machine translation to model the potential relationship
between two sentences. It typically consists of two parts: an encoder that
reads from the source sentence and a decoder that generates the target sentence
word by word according to the encoder's output and the last generated word.
However, it faces to the cold start problem when generating the first word as
there is no previous word to refer. Existing work mainly use a special start
symbol </s>to generate the first word. An obvious drawback of these work is
that there is not a learnable relationship between words and the start symbol.
Furthermore, it may lead to the error accumulation for decoding when the first
word is incorrectly generated. In this paper, we proposed a novel approach to
learning to generate the first word in the sequence to sequence architecture
rather than using the start symbol. Experimental results on the task of
response generation of short text conversation show that the proposed approach
outperforms the state-of-the-art approach in both of the automatic and manual
evaluations.


title: Periodic Solutions of vdP and vdP-like Systems on $3$--Tori

abstract:
  Van der Pol equation (in short, vdP) as well as many its non-symmetric
generalizations (the so-called van der Pol-like oscillators (in short, vdPl))
serve as nodes in coupled networks modeling real-life phenomena. Symmetric
properties of periodic regimes of networks of vdP/vdPl depend on symmetries of
coupling. In this paper, we consider $N^3$ identical vdP/vdPl oscillators
arranged in a cubical lattice, where opposite faces are identified in the same
way as for a $3$-torus. Depending on which nodes impact the dynamics of a given
node, we distinguish between $\mathbb D_N \times \mathbb D_N \times \mathbb
D_N$-equivariant systems and their $\mathbb Z_N \times \mathbb Z_N \times
\mathbb Z_N$-equivariant counterparts. In both settings, the local equivariant
Hopf bifurcation together with the global existence of periodic solutions with
prescribed period and symmetry, are studied. The methods used in the paper are
based on the results rooted in both equivariant degree theory and (equivariant)
singularity theory


title:
Minimal Basis Iterative Stockholder: Atoms in Molecules for Force-Field
  Development

abstract:
  Atomic partial charges appear in the Coulomb term of many force-field models
and can be derived from electronic structure calculations with a myriad of
atoms-in-molecules (AIM) methods. More advanced models have also been proposed,
using the distributed nature of the electron cloud and atomic multipoles. In
this work, an electrostatic force field is defined through a concise
approximation of the electron density, for which the Coulomb interaction is
trivially evaluated. This approximate "pro-density" is expanded in a minimal
basis of atom-centered s-type Slater density functions, whose parameters are
optimized by minimizing the Kullback-Leibler divergence of the pro-density from
a reference electron density, e.g. obtained from an electronic structure
calculation. The proposed method, Minimal Basis Iterative Stockholder (MBIS),
is a variant of the Hirshfeld AIM method but it can also be used as a
density-fitting technique. An iterative algorithm to refine the pro-density is
easily implemented with a linear-scaling computational cost, enabling
applications to supramolecular systems. The benefits of the MBIS method are
demonstrated with systematic applications to molecular databases and extended
models of condensed phases. A comparison to 14 other AIM methods shows its
effectiveness when modeling electrostatic interactions. MBIS is also suitable
for rescaling atomic polarizabilities in the Tkatchenko-Sheffler scheme for
dispersion interactions.

categories: physics.chem-ph physics.atm-clus physics.atom-ph physics.comp-ph quant-ph


title:
The Shape of Dark Matter Haloes II. The Galactus HI Modelling & Fitting
  Tool

abstract:
  We present a new HI modelling tool called \textsc{Galactus}. The program has
been designed to perform automated fits of disc-galaxy models to observations.
It includes a treatment for the self-absorption of the gas. The software has
been released into the public domain. We describe the design philosophy and
inner workings of the program. After this, we model the face-on galaxy NGC2403,
using both self-absorption and optically thin models, showing that
self-absorption occurs even in face-on galaxies. It is shown that the maximum
surface brightness plateaus seen in Paper I of this series are indeed signs of
self-absorption. The apparent HI mass of an edge-on galaxy can be drastically
lower compared to that same galaxy seen face-on. The Tully-Fisher relation is
found to be relatively free from self-absorption issues.


title: Neutrino induced vorticity, Alfven waves and the normal modes

abstract:
  We consider plasma consisting of electrons and ions in presence of a
background neutrino gas and develop the magneto hydrodynamic equations for the
system. We show that electron neutrino interaction can induce vorticity in the
plasma even in the absence of any electromagnetic perturbations if the
background neutrino density is left-right asymmetric. This induced vorticity
support a new kind of Alfv\'en wave whose velocity depends on both the external
magnetic field and on the neutrino asymmetry. The normal mode analysis show
that in the presence of neutrino background the Alfv\'en waves can have
different velocities. We also discuss our results in the context of dense
astrophysical plasma such as magnetars and show that the difference in the
Alfv\'en velocities can be used to explain the observed pulsar kick. We discuss
also the relativistic generalization of electron fluid in presence of
asymmetric neutrino background.


title:
The Shape of Dark Matter Haloes III. Kinematics and Structure of the HI
  disc

abstract:
  We present a new strategy for fitting the structure and kinematics of the HI
in edge-on galaxies using a fit to the terminal-velocity channel maps of a HI
data cube. The strategy can deal with self-absorbing HI gas and the presence of
warps. The method is first tested on a series of models. We demonstrate that
fitting optically thin models to real galaxies will lead to an overestimation
of the thickness and velocity dispersion, and to a serious underestimation of
the HI face-on column densities. We subsequently fit both self-absorption and
optically thin models to the HI data of six edge-on galaxies. In three of these
we have also measured the velocity dispersion. On average 27 \pm 6 % of the
total HI mass of edge-on galaxies is hidden by self-absorption. This implies
that the HI mass, thickness and velocity dispersion of galaxies is typically
underestimated in the literature.


title:
Iterative Views Agreement: An Iterative Low-Rank based Structured
  Optimization Method to Multi-View Spectral Clustering

abstract:
  Multi-view spectral clustering, which aims at yielding an agreement or
consensus data objects grouping across multi-views with their graph laplacian
matrices, is a fundamental clustering problem. Among the existing methods,
Low-Rank Representation (LRR) based method is quite superior in terms of its
effectiveness, intuitiveness and robustness to noise corruptions. However, it
aggressively tries to learn a common low-dimensional subspace for multi-view
data, while inattentively ignoring the local manifold structure in each view,
which is critically important to the spectral clustering; worse still, the
low-rank minimization is enforced to achieve the data correlation consensus
among all views, failing to flexibly preserve the local manifold structure for
each view. In this paper, 1) we propose a multi-graph laplacian regularized LRR
with each graph laplacian corresponding to one view to characterize its local
manifold structure. 2) Instead of directly enforcing the low-rank minimization
among all views for correlation consensus, we separately impose low-rank
constraint on each view, coupled with a mutual structural consensus constraint,
where it is able to not only well preserve the local manifold structure but
also serve as a constraint for that from other views, which iteratively makes
the views more agreeable. Extensive experiments on real-world multi-view data
sets demonstrate its superiority.


title: G11.92-0.61 MM1: A Keplerian disc around a massive young proto-O star

abstract:
  The formation process of massive stars is not well understood, and
advancement in our understanding benefits from high resolution observations and
modelling of the gas and dust surrounding individual high-mass (proto)stars.
Here we report sub-arcsecond (<1550 au) resolution observations of the young
massive star G11.92-0.61 MM1 with the SMA and VLA. Our 1.3 mm SMA observations
reveal consistent velocity gradients in compact molecular line emission from
species such as CH$_3$CN, CH$_3$OH, OCS, HNCO, H$_2$CO, DCN and CH$_3$CH$_2$CN,
oriented perpendicular to the previously reported bipolar molecular outflow
from MM1. Modelling of the compact gas kinematics suggests a structure
undergoing rotation around the peak of the dust continuum emission. The
rotational profile can be well fit by a model of a Keplerian disc, including
infall, surrounding an enclosed mass of 30-60M$_{\odot}$, of which
2-3M$_{\odot}$ is attributed to the disc. From modelling the CH$_3$CN emission,
we determine that two temperature components, of 150 K and 230 K, are required
to adequately reproduce the spectra. Our 0.9 and 3.0cm VLA continuum data
exhibit an excess above the level expected from dust emission; the full
centimetre-submillimetre wavelength spectral energy distribution of MM1 is well
reproduced by a model including dust emission, an unresolved hypercompact
H{\i}{\i} region, and a compact ionised jet. In combination, our results
suggest that MM1 is an example of a massive proto-O star forming via disc
accretion, in a similar way to that of lower mass stars.


title:
Rigid Slice-To-Volume Medical Image Registration through Markov Random
  Fields

abstract:
  Rigid slice-to-volume registration is a challenging task, which finds
application in medical imaging problems like image fusion for image guided
surgeries and motion correction for volume reconstruction. It is usually
formulated as an optimization problem and solved using standard continuous
methods. In this paper, we discuss how this task be formulated as a discrete
labeling problem on a graph. Inspired by previous works on discrete estimation
of linear transformations using Markov Random Fields (MRFs), we model it using
a pairwise MRF, where the nodes are associated to the rigid parameters, and the
edges encode the relation between the variables. We compare the performance of
the proposed method to a continuous formulation optimized using simplex, and we
discuss how it can be used to further improve the accuracy of our approach.
Promising results are obtained using a monomodal dataset composed of magnetic
resonance images (MRI) of a beating heart.


title:
The Shape of Dark Matter Haloes IV. The Structure of Stellar Discs in
  Edge-on Galaxies

abstract:
  We present optical and near-infrared archival observations of eight edge-on
galaxies. These observations are used to model the stellar content of each
galaxy using the FitSKIRT software package. Using FitSKIRT, we can
self-consistently model a galaxy in each band simultaneously while treating for
dust. This allows us to accurately measure both the scale length and scale
height of the stellar disc, plus the shape parameters of the bulge. By
combining this data with the previously reported integrated magnitudes of each
galaxy, we can infer their true luminosities. We have successfully modelled
seven out of the eight galaxies in our sample. We find that stellar discs can
be modelled correctly, but have not been able to model the stellar bulge
reliably. Our sample consists for the most part of slow rotating galaxies, and
we find that the average dust layer is much thicker than what is reported for
faster rotating galaxies.


title:
Living in Parallel Realities -- Co-Existing Schema Versions with a
  Bidirectional Database Evolution Language

abstract:
  We introduce end-to-end support of co-existing schema versions within one
database. While it is state of the art to run multiple versions of a
continuously developed application concurrently, it is hard to do the same for
databases. In order to keep multiple co-existing schema versions alive; which
are all accessing the same data set; developers usually employ handwritten
delta code (e.g. views and triggers in SQL). This delta code is hard to write
and hard to maintain: if a database administrator decides to adapt the physical
table schema, all handwritten delta code needs to be adapted as well, which is
expensive and error-prone in practice. In this paper, we present InVerDa:
developers use the simple bidirectional database evolution language BiDEL,
which carries enough information to generate all delta code automatically.
Without additional effort, new schema versions become immediately accessible
and data changes in any version are visible in all schema versions at the same
time. InVerDa also allows for easily changing the physical table design without
affecting the availability of co-existing schema versions. This greatly
increases robustness (orders of magnitude less lines of code) and allows for
significant performance optimization. A main contribution is the formal
evaluation that each schema version acts like a common full-fledged database
schema independently of the chosen physical table design.


title:
Uncertainty propagation of p-boxes using sparse polynomial chaos
  expansions

abstract:
  In modern engineering, physical processes are modelled and analysed using
advanced computer simulations, such as finite element models. Furthermore,
concepts of reliability analysis and robust design are becoming popular, hence,
making efficient quantification and propagation of uncertainties an important
aspect. In this context, a typical workflow includes the characterization of
the uncertainty in the input variables. In this paper, input variables are
modelled by probability-boxes (p-boxes), accounting for both aleatory and
epistemic uncertainty. The propagation of p-boxes leads to p-boxes of the
output of the computational model. A two-level meta-modelling approach is
proposed using non-intrusive sparse polynomial chaos expansions to surrogate
the exact computational model and, hence, to facilitate the uncertainty
quantification analysis. The capabilities of the proposed approach are
illustrated through applications using a benchmark analytical function and two
realistic engineering problem settings. They show that the proposed two-level
approach allows for an accurate estimation of the statistics of the response
quantity of interest using a small number of evaluations of the exact
computational model. This is crucial in cases where the computational costs are
dominated by the runs of high-fidelity computational models.


title: Long time asymptotic state of periodically driven open quantum systems

abstract:
  We investigate a long time asymptotic state of periodically driven open
quantum systems analytically. The model we consider in this paper is a free
fermionic system coupled to an energy and particle reservoir. We clarify some
generic properties of the system which are independent of the details of the
reservoir in the high frequency regime of the external driving. When the
frequency of the external driving is much larger than the energy cutoff of the
system-reservoir coupling, the low-energy properties of the system are
equivalent to those of the Gibbs distribution of a Floquet effective
Hamiltonian. Furthermore, we investigate the effect of finite dissipation on
the system, and elucidate that we cannot suppress excitations by merely
increasing the system-reservoir coupling because the excitations are created
through the reservoir by the external driving when the frequency is smaller
than the energy cutoff of the system-reservoir coupling.


title: The Gelfand-Tsetlin-Zhelobenko base vectors for the series $B$

abstract:
  In the paper using the method of $Z$-invariants of Zhelobenko we construct
base vectors of Gelfand-Tsetlin type in a representation of
$\mathfrak{o}_{2n+1}$, based on restrictions
$\mathfrak{o}_{2n+1}\downarrow\mathfrak{o}_{2n-1}$. The construction is based
on a discovered relation between restriction problems
$\mathfrak{o}_{2n+1}\downarrow\mathfrak{o}_{2n-1}$ and
$\mathfrak{gl}_{n+1}\downarrow\mathfrak{gl}_{n-1}$.


title:
Progressive magnetic softening of ferromagnetic layers in multilayer
  ferromagnet-nonmagnet systems and the role of granularity

abstract:
  We report a study of the structural and magnetic behavior of the topmost
magnetic layer in a ferromagnet-nonmagnet (Co-Au) multilayer system. Glancing
angle X-ray diffraction measurements performed on a series of multilayers
showed a gradually increasing degree of amorphization of the topmost magnetic
layer with increasing number of bilayers. Concurrently, the magnetic hardness
and magneto-crystalline anisotropy of the top Co layer were found to decrease,
as observed by magneto-optical Kerr effect measurements. This magnetic
softening has been discussed in the light of Herzer's random anisotropy model.
Micromagnetic simulations of the multilayer system also corroborated these
observations.


title: Motivic invariants of moduli spaces of rank 2 Bradlow - Higgs triples

abstract:
  In the present thesis we study the geometry of the moduli spaces of
Bradlow-Higgs triples on a smooth projective curve $C$. $(E,\varphi, s)$ is a
Bradlow-Higgs triple if $(E,\varphi)$ is a Higgs bundle and $s$ is a non-zero
global section of $E$. There is a family of stability conditions for triples
that depends on a positive real parameter $\sigma$. The moduli spaces
$\mathcal{M}_\sigma^{r,d}$ of $\sigma$-semistable triples of rank $r$ and
degree $d$ vary with $\sigma$. The phenomenon arising from this is known as
wall-crossing. In the first half of the thesis we will examine how the moduli
spaces $\mathcal{M}_\sigma^{r,d}$ and their universal additive invariants
change as $\sigma$ varies, for the case $r=2$. In particular we will study the
case of $\sigma$ very close to 0, for which $\mathcal{M}_\sigma^{r,d}$ relates
to the moduli space of stable Higgs bundles, and $\sigma$ very large, for which
$\mathcal{M}_\sigma^{r,d}$ is a relative Hilbert scheme of points for the
family of spectral curves. Some of these results will be generalized to
Bradlow-Higgs triples with poles. In the second half we will prove a formula
relating the cohomology of $\mathcal{M}_\sigma^{2,d}$ for small $\sigma$ and
$d$ odd and the perverse filtration on the cohomology of the moduli space of
stable Higgs bundles. The formula is not far from the generalized Macdonald
formulas found in the works of Migliorini-Shende, Maulik-Yun and
Migliorini-Shende-Viviani. We will also partially generalize this result to the
case of rank greater than 2.


title:
A Temporal Consistent Monolithic Approach to Fluid-Structure Interaction
  Enabling Single Field Predictors

abstract:
  We present a monolithic approach to large-deformation fluid-structure
interaction (FSI) problems that allows for choosing fully implicit, single-step
and single-stage time integration schemes in the structure and fluid field
independently, and hence is tailored to the needs of the individual field. The
independent choice of time integration schemes is achieved by temporal
consistent interpolation of the interface traction. To reduce computational
costs, we introduce the possibility of field specific predictors in both
structure and fluid field. These predictors act on the single fields only.
Possible violations of the interface coupling conditions during the predictor
step are dealt with within the monolithic solution procedure. We present full
detail of such a generalized monolithic solution procedure, which is fully
consistent in its non-conforming temporal and spatial discretization. The
incorporated mortar approach allows for non-matching spatial discretizations of
the fluid and solid domain at the FSI interface and is fully integrated in the
resulting monolithic system of equations. The method is applied to a variety of
numerical examples. Thereby, temporal convergence rates, the special role of
essential boundary conditions at the fluid-structure interface, and the
positive effect of predictors are demonstrated and discussed. Emphasis is put
on the comparison of different time integration schemes in fluid and structure
field, for what the achieved freedom of choice of time integrators is fully
exploited.


title: Learning Spatially Regularized Correlation Filters for Visual Tracking

abstract:
  Robust and accurate visual tracking is one of the most challenging computer
vision problems. Due to the inherent lack of training data, a robust approach
for constructing a target appearance model is crucial. Recently,
discriminatively learned correlation filters (DCF) have been successfully
applied to address this problem for tracking. These methods utilize a periodic
assumption of the training samples to efficiently learn a classifier on all
patches in the target neighborhood. However, the periodic assumption also
introduces unwanted boundary effects, which severely degrade the quality of the
tracking model.
  We propose Spatially Regularized Discriminative Correlation Filters (SRDCF)
for tracking. A spatial regularization component is introduced in the learning
to penalize correlation filter coefficients depending on their spatial
location. Our SRDCF formulation allows the correlation filters to be learned on
a significantly larger set of negative training samples, without corrupting the
positive samples. We further propose an optimization strategy, based on the
iterative Gauss-Seidel method, for efficient online learning of our SRDCF.
Experiments are performed on four benchmark datasets: OTB-2013, ALOV++,
OTB-2015, and VOT2014. Our approach achieves state-of-the-art results on all
four datasets. On OTB-2013 and OTB-2015, we obtain an absolute gain of 8.0% and
8.2% respectively, in mean overlap precision, compared to the best existing
trackers.


title:
Dipolar dissociation dynamics in electron collisions with carbon
  monoxide

abstract:
  Dipolar dissociation processes in the electron collisions with carbon
monoxide have been studied using time of flight (TOF) mass spectroscopy in
combination with the highly differential velocity slice imaging (VSI)
technique. Probing ion-pair states both positive and/or negative ions may be
detected. The ion yield curve of negative ions provides the threshold energy
for the ion-pair production. On the other hand, the kinetic energy
distributions and angular distributions of the fragment anion provide detailed
dynamics of the dipolar dissociation process. Two ion-pair states have been
identified based on angular distribution measurements using VSI technique.


title:
Packing chromatic number, $(1,1,2,2)$-colorings, and characterizing the
  Petersen graph

abstract:
  The packing chromatic number $\chi_{\rho}(G)$ of a graph $G$ is the smallest
integer $k$ such that the vertex set of $G$ can be partitioned into sets
$\Pi_1,\ldots,\Pi_k$, where $\Pi_i$, $i\in [k]$, is an $i$-packing. The
following conjecture is posed and studied: if $G$ is a subcubic graph, then
$\chi_{\rho}(S(G))\le 5$, where $S(G)$ is the subdivision of $G$. The
conjecture is proved for all generalized prisms of cycles. To get this result
it is proved that if $G$ is a generalized prism of a cycle, then $G$ is
$(1,1,2,2)$-colorable if and only if $G$ is not the Petersen graph. The
validity of the conjecture is further proved for graphs that can be obtained
from generalized prisms in such a way that one of the two $n$-cycles in the
edge set of a generalized prism is replaced by a union of cycles among which at
most one is a 5-cycle. The packing chromatic number of graphs obtained by
subdividing each of its edges a fixed number of times is also considered.


title: Guido Altarelli and the evolution of QCD

abstract:
  I describe the contributions of Guido Altarelli to the development of Quantum
Chromodynamics from the discovery of asymptotic freedom until the end of the
S$p\bar{p}$S collider era, 1973-1985.


title: On equivariant binary differential equations

abstract:
  This paper introduces the study of occurrence of symmetries in binary
differential equations (BDEs). These are implicit differential equations given
by the zeros of a quadratic 1-form, $a(x,y)dy^2 + b(x,y)dxdy + c(x,y)dx^2 = 0,$
for $a, b, c$ smooth real functions defined on an open set of $\mathbb{R}^2$.
Generically, solutions of a BDE are given as leaves of a pair of foliations,
and the appropriate way to define the action of a symmetry must depend not only
whether it preserves or inverts the plane orientation, but also whether it
preserves or interchanges the foliations. The first main result reveals this
dependence, which is given algebraically by a formula relating three group
homomorphisms defined on the symmetry group of the BDE. The second main result
adapts algebraic methods from invariant theory for representations of compact
Lie groups on the space of quadratic forms on $\mathbb{R}^n$, $n \geq 2$. With
that we obtain an algorithm to compute general expressions of quadratic forms.
Now, symmetric quadratic 1-forms are in one-to-one corrspondence with
equivariant quadratic forms on the plane, so these are treated here as a
particular case. We then apply the result to obtain the general forms of
equivariant quadratic 1-forms under each compact subgroup of the orthogonal
group $\mathbf{O}(2)$.


title: On the norming constants of the Sturm-Liouville problem

abstract:
  We derive new asymptotic formulae for the norming constants of
Sturm-Liouville problem with summable potentials, which generalize and make
more precise previously known formulae. Moreover, our formulae take into
account the smooth dependence of norming constants on boundary conditions. We
also find some new properties of the remainder terms of asymptotics.


title: Packing chromatic number under local changes in a graph

abstract:
  The packing chromatic number $\chi_{\rho}(G)$ of a graph $G$ is the smallest
integer $k$ such that there exists a $k$-vertex coloring of $G$ in which any
two vertices receiving color $i$ are at distance at least $i+1$. It is proved
that in the class of subcubic graphs the packing chromatic number is bigger
than $13$, thus answering an open problem from [Gastineau, Togni, $S$-packing
colorings of cubic graphs, Discrete Math.\ 339 (2016) 2461--2470]. In addition,
the packing chromatic number is investigated with respect to several local
operations. In particular, if $S_e(G)$ is the graph obtained from a graph $G$
by subdividing its edge $e$, then $\left\lfloor \chi_{\rho}(G)/2 \right\rfloor
+1 \le \chi_{\rho}(S_e(G)) \le \chi_{\rho}(G)+1$.


title: Haploid-Diploid Evolutionary Algorithms

abstract:
  This paper uses the recent idea that the fundamental haploid-diploid
lifecycle of eukaryotic organisms implements a rudimentary form of learning
within evolution. A general approach for evolutionary computation is here
derived that differs from all previous known work using diploid
representations. The primary role of recombination is also changed from that
previously considered in both natural and artificial evolution under the new
view. Using well-known abstract tuneable models it is shown that varying
fitness landscape ruggedness varies the benefit of the new approach.


title:
The giant frequency shift of intramolecular O-H vibration band in the
  raman spectra of water on the silver surface

abstract:
  The giant frequency shift was observed in Raman spectra for inramolecular O-H
vibration band. The effect was observed in SERS-condition experiment, when
exciting light was focused by short-focus objective on the Ag-surface, merged
in water. The shift was detected relatively to the regularl position of band,
measured from the bulk of water under the same other conditions.


title:
A partially mesh-free scheme for representing anisotropic spatial
  variations along field lines

abstract:
  A common numerical task is to represent functions which are highly spatially
anisotropic, and to solve differential equations related to these functions.
One way such anisotropy arises is that information transfer along one spatial
direction is much faster than in others. In this situation, the derivative of
the function is small in the local direction of a vector field $\mathbf{b}$. In
order to define a discrete representation, a set of surfaces $M_i$ indexed by
an integer $i$ are chosen such that mapping along the field $\mathbf{b}$
induces a one-to-one relation between the points on surface $M_i$ to those on
$M_{i+1}$. For simple cases $M_i$ may be surfaces of constant coordinate value.
On each surface $M_i$, a function description is constructed using basis
functions defined on a regular structured mesh. The definition of each basis
function is extended from the surface $M$ along the lines of the field
$\mathbf{b}$ by multiplying it by a smooth compact support function whose
argument increases with distance along $\mathbf{b}$. Function values are
evaluated by summing contributions associated with each surface $M_i$. This
does not require any special connectivity of the meshes used in the
neighbouring surfaces $M$, which substantially simplifies the meshing problem
compared to attempting to find a space filling anisotropic mesh. We explore the
numerical properties of the scheme, and show that it can be used to efficiently
solve differential equations for certain anisotropic problems.


title:
Unsupervised Feature Selection Based on the Morisita Estimator of
  Intrinsic Dimension

abstract:
  This paper deals with a new filter algorithm for selecting the smallest
subset of features carrying all the information content of a data set (i.e. for
removing redundant features). It is an advanced version of the fractal
dimension reduction technique, and it relies on the recently introduced
Morisita estimator of Intrinsic Dimension (ID). Here, the ID is used to
quantify dependencies between subsets of features, which allows the effective
processing of highly non-linear data. The proposed algorithm is successfully
tested on simulated and real world case studies. Different levels of sample
size and noise are examined along with the variability of the results. In
addition, a comprehensive procedure based on random forests shows that the data
dimensionality is significantly reduced by the algorithm without loss of
relevant information. And finally, comparisons with benchmark feature selection
techniques demonstrate the promising performance of this new filter.


title: Machine learning applied to proton radiography

abstract:
  Proton radiography is a technique extensively used to resolve magnetic field
structures in high energy density plasmas, revealing a whole variety of
interesting phenomena such as magnetic reconnection and collisionless shocks
found in astrophysical systems. Existing methods of analyzing proton
radiographs give mostly qualitative results or specific quantitative parameters
such as magnetic field strength, and recent work showed that the
line-integrated transverse magnetic field can be reconstructed in specific
regimes where many simplifying assumptions were needed. Using artificial neural
networks, we suggest a novel 3-D reconstruction method that works for a more
general case. A proof of concept is presented here, with mean reconstruction
errors of less than 5 percent even after introducing noise. We demonstrate that
over the long term, this approach is more computationally efficient compared to
other techniques. We also highlight the need for proton tomography because (i)
certain field structures cannot be reconstructed from a single radiograph and
(ii) errors can be further reduced when reconstruction is performed on
radiographs generated by proton beams fired in different directions.


title:
Bayesian inference for continuous time animal movement based on steps
  and turns

abstract:
  Although animal locations gained via GPS, etc. are typically observed on a
discrete time scale, movement models formulated in continuous time are
preferable in order to avoid the struggles experienced in discrete time when
faced with irregular observations or the prospect of comparing analyses on
different time scales. A class of models able to emulate a range of movement
ideas are defined by representing movement as a combination of stochastic
processes describing both speed and bearing. A method for Bayesian inference
for such models is described through the use of a Markov chain Monte Carlo
approach. Such inference relies on an augmentation of the animal's locations in
discrete time that have been observed with error, with a more detailed movement
path gained via simulation techniques. Analysis on real data on an individual
reindeer (Rangifer tarandus) illustrates the presented methods.


title:
Time evolution during and after finite-time quantum quenches in the
  transverse-field Ising chain

abstract:
  We study the time evolution in the transverse-field Ising chain subject to
quantum quenches of finite duration, ie, a continuous change in the transverse
magnetic field over a finite time. Specifically, we consider the dynamics of
the total energy, one- and two-point correlation functions and Loschmidt echo
during and after the quench as well as their stationary behaviour at late
times. We investigate how different quench protocols affect the dynamics and
identify universal properties of the relaxation.


title: Consistency of option prices under bid-ask spreads

abstract:
  Given a finite set of European call option prices on a single underlying, we
want to know when there is a market model which is consistent with these
prices. In contrast to previous studies, we allow models where the underlying
trades at a bid-ask spread. The main question then is how large (in terms of a
deterministic bound) this spread must be to explain the given prices. We fully
solve this problem in the case of a single maturity, and give several partial
results for multiple maturities. For the latter, our main mathematical tool is
a recent result on approximation by peacocks [S. Gerhold, I.C. G\"ul\"uum,
arXiv:1512.06640].


title: Ultrafast Electronic Band Gap Control in an Excitonic Insulator

abstract:
  We report on the nonequilibrium dynamics of the electronic structure of the
layered semiconductor Ta$_2$NiSe$_5$ investigated by time- and angle-resolved
photoelectron spectroscopy. We show that below the critical excitation density
of $F_{C} = 0.2$ mJ cm$^{-2}$, the band gap $narrows$ transiently, while it is
$enhanced$ above $F_{C}$. Hartree-Fock calculations reveal that this effect can
be explained by the presence of the low-temperature excitonic insulator phase
of Ta$_2$NiSe$_5$, whose order parameter is connected to the gap size. This
work demonstrates the ability to manipulate the band gap of Ta$_2$NiSe$_5$ with
light on the femtosecond time scale.


title: Vesicles in magnetic fields

abstract:
  Liposome vesicles tend to align with an applied magnetic field. This is due
to the directional magnetic susceptibility difference of the lipids which form
the membrane of these vesicles. In this work a model of liposome vesicles
exposed to magnetic field is presented. Starting from the base energy of a
lipid membrane in a magnetic field, the force applied to the surrounding fluids
is derived. This force is then used to investigate the dynamics of vesicle in
the presence of magnetic fields.


title:
Strong coupling constant of negative parity nucleon with $\pi$ meson in
  light cone QCD sum rules

abstract:
  We estimate strong coupling constant between the negative parity nucleons
with $\pi$ meson within the light cone QCD sum rules. A method for eliminating
the unwanted contributions coming from the nucleon--nucleon and
nucleon--negative parity nucleon transition is presented. It is observed that
the value strong coupling constant of the negative parity nucleon $N^\ast
N^\ast \pi$ transition is considerably different from the one predicted by the
3--point QCD sum rules, but is quite close to the coupling constant of the
positive parity $N N \pi$ transition.


title: Rigidity for partially hyperbolic diffeomorphisms

abstract:
  In this work we completely classify $C^\infty$ conjugacy for conservative
partially hyperbolic diffeomorphisms homotopic to a linear Anosov automorphism
on the 3-torus by its center foliation behavior. We prove that the uniform
version of absolute continuity for the center foliation is the natural
hypothesis to obtain $C^\infty$ conjugacy to its linear Anosov automorphism. On
a recent work Avila, Viana and Wilkinson proved that for a perturbation in the
volume preserving case of the time-one map of an Anosov flow absolute
continuity of the center foliation implies smooth rigidity. The absolute
version of absolute continuity is the appropriate sceneario for our context
since it is not possible to obtain an analogous result of Avila, Viana and
Wilkinson for our class of maps, for absolute continuity alone fails miserably
to imply smooth rigidity for our class of maps. Our theorem is a global
rigidity result as we do not assume the diffeomorphism to be at some distance
from the linear Anosov automorphism. We also do not assume ergodicity. In
particular a metric condition on the center foliation implies ergodicity and
$C^\infty$ center foliation.


title:
Fluctuations of the increment of the argument for the Gaussian entire
  function

abstract:
  The Gaussian entire function is a random entire function, characterised by a
certain invariance with respect to isometries of the plane. We study the
fluctuations of the increment of the argument of the Gaussian entire function
along planar curves. We introduce an inner product on finite formal linear
combinations of curves (with real coefficients), that we call the signed
length, which describes the limiting covariance of the increment. We also
establish asymptotic normality of fluctuations.


title:
Diagonalizing Quadratic Bosonic Operators by Non-Autonomous Flow
  Equation

abstract:
  We study a non-autonomous, non-linear evolution equation on the space of
operators on a complex Hilbert space. We specify assumptions that ensure the
global existence of its solutions and allow us to derive its asymptotics at
temporal infinity. We demonstrate that these assumptions are optimal in a
suitable sense and more general than those used before. The evolution equation
derives from the Brocket-Wegner flow that was proposed to diagonalize matrices
and operators by a strongly continuous unitary flow. In fact, the solution of
the non-linear flow equation leads to a diagonalization of Hamiltonian
operators in boson quantum field theory which are quadratic in the field.


title: Milankovitch Cycles of Terrestrial Planets in Binary Star Systems

abstract:
  The habitability of planets in binary star systems depends not only on the
radiation environment created by the two stars, but also on the perturbations
to planetary orbits and rotation produced by the gravitational field of the
binary and neighbouring planets. Habitable planets in binaries may therefore
experience significant perturbations in orbit and spin. The direct effects of
orbital resonances and secular evolution on the climate of binary planets
remain largely unconsidered.
  We present latitudinal energy balance modelling of exoplanet climates with
direct coupling to an N Body integrator and an obliquity evolution model. This
allows us to simultaneously investigate the thermal and dynamical evolution of
planets orbiting binary stars, and discover gravito-climatic oscillations on
dynamical and secular timescales.
  We investigate the Kepler-47 and Alpha Centauri systems as archetypes of P
and S type binary systems respectively. In the first case, Earthlike planets
would experience rapid Milankovitch cycles (of order 1000 years) in
eccentricity, obliquity and precession, inducing temperature oscillations of
similar periods (modulated by other planets in the system). These secular
temperature variations have amplitudes similar to those induced on the much
shorter timescale of the binary period.
  In the Alpha Centauri system, the influence of the secondary produces
eccentricity variations on 15,000 year timescales. This produces climate
oscillations of similar strength to the variation on the orbital timescale of
the binary. Phase drifts between eccentricity and obliquity oscillations
creates further cycles that are of order 100,000 years in duration, which are
further modulated by neighbouring planets.


title: SOAR Adaptive Module (SAM): seeing improvement with a UV laser

abstract:
  The adaptive module of the 4.1-m SOAR telescope, SAM, corrects ground-layer
turbulence using a UV laser guide star. It has been commissioned in 2013 and it
is in regular science operation since 2014. SAM works with the CCD imager
covering a 3' field or with the speckle camera. It operates routinely and
stably, delivering resolution in the I band equal to the free-atmosphere
seeing. This paper describes the SAM system as a whole, providing essential
reference for its users and technical information of interest to
instrumentalists. Operation of the instrument, its performance, and science
projects done with SAM so far are reviewed.


title: On Joining Graphs

abstract:
  In the graph database literature the term "join" does not refer to an
operator used to merge two graphs. In particular, a counterpart of the
relational join is not present in existing graph query languages, and
consequently no efficient algorithms have been developed for this operator.
  This paper provides two main contributions. First, we define a binary graph
join operator that acts on the vertices as a standard relational join and
combines the edges according to a user-defined semantics. Then we propose the
"CoGrouped Graph Conjunctive $\theta$-Join" algorithm running over data indexed
in secondary memory. Our implementation outperforms the execution of the same
operation in Cypher and SPARQL on major existing graph database management
systems by at least one order of magnitude, also including indexing and loading
time.


title:
Fundamental aspects of steady-state conversion of heat to work at the
  nanoscale

abstract:
  In recent years, the study of heat to work conversion has been re-invigorated
by nanotechnology. Steady-state devices do this conversion without any
macroscopic moving parts, through steady-state flows of microscopic particles
such as electrons, photons, phonons, etc. This review aims to introduce some of
the theories used to describe these steady-state flows in a variety of
mesoscopic or nanoscale systems. These theories are introduced in the context
of idealized machines which convert heat into electrical power (heat-engines)
or convert electrical power into a heat flow (refrigerators). In this sense,
the machines could be categorized as thermoelectrics, although this should be
understood to include photovoltaics when the heat source is the sun. As quantum
mechanics is important for most such machines, they fall into the field of
quantum thermodynamics. In many cases, the machines we consider have few
degrees of freedom, however the reservoirs of heat and work that they interact
with are assumed to be macroscopic. This review discusses different theories
which can take into account different aspects of mesoscopic and nanoscale
physics, such as coherent quantum transport, magnetic-field induced effects
(including topological ones such as the quantum Hall effect), and single
electron charging effects. It discusses the efficiency of thermoelectric
conversion, and the thermoelectric figure of merit. More specifically, the
theories presented are (i) linear response theory with or without magnetic
fields, (ii) Landauer scattering theory in the linear response regime and far
from equilibrium, (iii) Green-Kubo formula for strongly interacting systems
within the linear response regime, (iv) rate equation analysis for small
quantum machines with or without ..... (SEE THE PDF FOR THE REST OF THIS
ABSTRACT)


title: On rank of von Neumann special flows

abstract:
  We prove that special flows over an ergodic rotation of the circle under a
$C^1$ roof function with one discontinuity do not have local rank one. In
particular, any such flow has infinite rank.


title: The structure of the climate debate

abstract:
  First-best climate policy is a uniform carbon tax which gradually rises over
time. Civil servants have complicated climate policy to expand bureaucracies,
politicians to create rents. Environmentalists have exaggerated climate change
to gain influence, other activists have joined the climate bandwagon. Opponents
to climate policy have attacked the weaknesses in climate research. The climate
debate is convoluted and polarized as a result, and climate policy complex.
Climate policy should become easier and more rational as the Paris Agreement
has shifted climate policy back towards national governments. Changing
political priorities, austerity, and a maturing bureaucracy should lead to a
more constructive climate debate.


title: A Geometric Heat-Flow Theory of Lagrangian Coherent Structures

abstract:
  We consider Lagrangian coherent structures (LCSs) as the boundaries of
material subsets whose advective evolution is metastable under weak diffusion.
For their detection, we first transform the Eulerian advection-diffusion
equation to Lagrangian coordinates, in which it takes the form of a
time-dependent diffusion or heat equation. By this coordinate transformation,
the reversible effects of advection are separated from the irreversible joint
effects of advection and diffusion. In this framework, LCSs express themselves
as (boundaries of) metastable sets under the Lagrangian diffusion process. In
the case of spatially homogeneous isotropic diffusion, averaging the
time-dependent family of Lagrangian diffusion operators yields Froyland's
dynamic Laplacian. In the associated geometric heat equation, the distribution
of heat is governed by the dynamically induced intrinsic geometry on the
material manifold, to which we refer as the geometry of mixing. We study and
visualize this geometry in detail, and discuss connections between geometric
features and LCSs viewed as diffusion barriers in two numerical examples. Our
approach facilitates the discovery of connections between some prominent
methods for coherent structure detection: the dynamic isoperimetry methodology,
the variational geometric approaches to elliptic LCSs, a class of graph
Laplacian-based methods and the effective diffusivity framework used in
physical oceanography.


title:
A criterion of solvability of the elliptic Cauchy problem in a
  multi-dimensional cylindrical domain

abstract:
  In this paper we consider the Cauchy problem for multidimensional elliptic
equations in a cylindrical domain. The method of spectral expansion in
eigenfunctions of the Cauchy problem for equations with deviating argument
establishes a criterion of the strong solvability of the considered elliptic
Cauchy problem. It is shown that the ill-posedness of the elliptic Cauchy
problem is equivalent to the existence of an isolated point of the continuous
spectrum for a self-adjoint operator with deviating argument.


title:
A VLT/FORS2 spectroscopic survey of individual stars in a transforming
  dwarf galaxy

abstract:
  Understanding the properties of dwarf galaxies is important not only to put
them in their proper cosmological context, but also to understand the formation
and evolution of the most common type of galaxies. Dwarf galaxies are divided
into two main classes, dwarf irregulars (dIrrs) and dwarf spheroidals (dSphs),
which differ from each other mainly because the former are gas-rich objects
currently forming stars, while the latter are gas-deficient with no on-going
star formation. Transition types (dT) are thought to represent dIs in the
process of losing their gas, and can therefore shed light into the possible
process of dwarf irregulars (dIrrs) becoming gas-deficient, passively evolving
galaxies. Here we present preliminary results from our wide-area VLT/FORS2 MXU
spectroscopic survey of the Phoenix dT, from which we obtained line-of-sight
velocities and metallicities from the nIR Ca II triplet lines for a large
sample of individual Red Giant Branch stars.


title:
Low-Thrust Trajectory Design Using Reachability Sets near Asteroid 4769
  Castalia

abstract:
  We present a computational approach for the design of continuous low thrust
transfers around an asteroid. These transfers are computed through the use of a
reachability set generated on a lower dimensional Poincar\'e surface. Complex,
long duration transfer trajectories are highly sensitive to the initial guess
and generally have a small region of convergence. Computation of the reachable
set alleviates the need to generate an accurate initial guess for optimization.
From the reachable set, we chose a trajectory which minimizes a distance metric
towards the desired target. Successive computation of the reachable set allows
for the design of general transfer trajectories which iteratively approach the
target. We demonstrate this method by determining a transfer trajectory about
the asteroid 4769 Castalia.


title:
Some spectral properties and isoperimetric inequalities for a nonlocal
  Laplacian problem

abstract:
  In this paper we consider a non-local problem for a Laplace operator in a
multidimensional bounded symmetric domain. The investigated problem is an
analogue of the classical periodic boundary value problems in the case of
non-rectangular domain. We prove self-adjointness of the problem and show a
method of constructing eigenfunctions. We obtain an analogue of the Rayleigh
type inequality and some spectral inequalities for the first eigenvalue of the
nonlocal problem.


title:
Cross-stream transport of asymmetric particles driven by oscillating
  shear

abstract:
  We study the dynamics of asymmetric, deformable particles in oscillatory,
linear shear flow. By simulating the motion of a dumbbell, a ring polymer, and
a capsule we show that cross-stream migration occurs for asymmetric elastic
particles even in linear shear flow if the shear rate varies in time. The
migration is generic as it does not depend on the particle dimension.
Importantly, the migration velocity and migration direction are robust to
variations of the initial particle orientation, making our proposed scheme
suitable for sorting particles with asymmetric material properties.


title: Modeling Human Reading with Neural Attention

abstract:
  When humans read text, they fixate some words and skip others. However, there
have been few attempts to explain skipping behavior with computational models,
as most existing work has focused on predicting reading times (e.g.,~using
surprisal). In this paper, we propose a novel approach that models both
skipping and reading, using an unsupervised architecture that combines a neural
attention with autoencoding, trained on raw text using reinforcement learning.
Our model explains human reading behavior as a tradeoff between precision of
language understanding (encoding the input accurately) and economy of attention
(fixating as few words as possible). We evaluate the model on the Dundee
eye-tracking corpus, showing that it accurately predicts skipping behavior and
reading times, is competitive with surprisal, and captures known qualitative
features of human reading.


title:
Using Distributed Representations to Disambiguate Biomedical and
  Clinical Concepts

abstract:
  In this paper, we report a knowledge-based method for Word Sense
Disambiguation in the domains of biomedical and clinical text. We combine word
representations created on large corpora with a small number of definitions
from the UMLS to create concept representations, which we then compare to
representations of the context of ambiguous terms. Using no relational
information, we obtain comparable performance to previous approaches on the
MSH-WSD dataset, which is a well-known dataset in the biomedical domain.
Additionally, our method is fast and easy to set up and extend to other
domains. Supplementary materials, including source code, can be found at https:
//github.com/clips/yarn


title:
Propensity score analysis with partially observed confounders: how
  should multiple imputation be used?

abstract:
  Inverse probability of treatment weighting (IPTW) is a popular propensity
score (PS)-based approach to estimate causal effects in observational studies
at risk of confounding bias. A major issue when estimating the PS is the
presence of partially observed covariates. Multiple imputation (MI) is a
natural approach to handle missing data on covariates, but its use in the PS
context raises three important questions: (i) should we apply Rubin's rules to
the IPTW treatment effect estimates or to the PS estimates themselves? (ii)
does the outcome have to be included in the imputation model? (iii) how should
we estimate the variance of the IPTW estimator after MI? We performed a
simulation study focusing on the effect of a binary treatment on a binary
outcome with three confounders (two of them partially observed). We used MI
with chained equations to create complete datasets and compared three ways of
combining the results: combining treatment effect estimates (MIte); combining
the PS across the imputed datasets (MIps); or combining the PS parameters and
estimating the PS of the average covariates across the imputed datasets
(MIpar). We also compared the performance of these methods to complete case
(CC) analysis and the missingness pattern (MP) approach, a method which uses a
different PS model for each pattern of missingness. We also studied empirically
the consistency of these 3 MI estimators. Under a missing at random (MAR)
mechanism, CC and MP analyses were biased in most cases when estimating the
marginal treatment effect, whereas MI approaches had good performance in
reducing bias as long as the outcome was included in the imputation model.
However, only MIte was unbiased in all the studied scenarios and Rubin's rules
provided good variance estimates for MIte.


title: On the twists of interplanetary magnetic flux ropes observed at 1 AU

abstract:
  Magnetic flux ropes (MFRs) are one kind of fundamental structures in the
solar physics, and involved in various eruption phenomena. Twist,
characterizing how the magnetic field lines wind around a main axis, is an
intrinsic property of MFRs, closely related to the magnetic free energy and
stableness. So far it is unclear how much amount of twist is carried by MFRs in
the solar atmosphere and in heliosphere and what role the twist played in the
eruptions of MFRs. Contrasting to the solar MFRs, there are lots of in-situ
measurements of magnetic clouds (MCs), the large-scale MFRs in interplanetary
space, providing some important information of the twist of MFRs. Thus,
starting from MCs, we investigate the twist of interplanetary MFRs with the aid
of a velocity-modified uniform-twist force-free flux rope model. It is found
that most of MCs can be roughly fitted by the model and nearly half of them can
be fitted fairly well though the derived twist is probably over-estimated by a
factor of 2.5. By applying the model to 115 MCs observed at 1 AU, we find that
(1) the twist angles of interplanetary MFRs generally follow a trend of about
$0.6\frac{l}{R}$ radians, where $\frac{l}{R}$ is the aspect ratio of a MFR,
with a cutoff at about $12\pi$ radians AU$^{-1}$, (2) most of them are
significantly larger than $2.5\pi$ radians but well bounded by $2\frac{l}{R}$
radians, (3) strongly twisted magnetic field lines probably limit the expansion
and size of MFRs, and (4) the magnetic field lines in the legs wind more
tightly than those in the leading part of MFRs. These results not only advance
our understanding of the properties and behavior of interplanetary MFRs, but
also shed light on the formation and eruption of MFRs in the solar atmosphere.
A discussion about the twist and stableness of solar MFRs are therefore given.


title: An elementary approach to sofic equivalence relations

abstract:
  We present an elementary description of sofic equivalence relations, as well
as some permanence properties for soficity. We answer a question by Conley,
Kechris and Tucker-Drob of determining soficity in terms of the full group for
aperiodic relations.


title: Implementing a Relevance Tracker Module

abstract:
  PC(ID) extends propositional logic with inductive definitions: rule sets
under the well-founded semantics. Recently, a notion of relevance was
introduced for this language. This notion determines the set of undecided
literals that can still influence the satisfiability of a PC(ID) formula in a
given partial assignment. The idea is that the PC(ID) solver can make decisions
only on relevant literals without losing soundness and thus safely ignore
irrelevant literals.
  One important insight that the relevance of a literal is completely
determined by the current solver state. During search, the solver state changes
have an effect on the relevance of literals. In this paper, we discuss an
incremental, lightweight implementation of a relevance tracker module that can
be added to and interact with an out-of-the-box SAT(ID) solver.