title:
Some conditions for descent of line bundles to GIT quotients $(G/B
  \times G/B \times G/B)//G$

abstract:
  We consider the descent of line bundles to GIT quotients of products of flag
varieties. Let $G$ be a simple, connected, algebraic group over $\mathbb{C}$.
We fix a Borel subgroup $B$ and consider the diagonal action of $G$ on the
projective variety $X = G/B \times G/B \times G/B$. For any triple $(\lambda,
\mu, \nu)$ of dominant regular characters there is a $G$-equivariant line
bundle $\mathcal{L}$ on $X$. Then, $\mathcal{L}$ is said to descend to the GIT
quotient $\pi:[X(\mathcal{L})]^{ss} \rightarrow X(\mathcal{L})//G$ if there
exists a line bundle $\hat{\mathcal{L}}$ on $X(\mathcal{L})//G$ such that
$\mathcal{L}\mid_{[X(\mathcal{L})]^{ss}} \cong \pi^*\hat{\mathcal{L}}$.
  Let $Q$ be the root lattice, $\Lambda$ the weight lattice, and $d$ the least
common multiple of the coefficients of the highest root $\theta$ of the Lie
algebra $\mathfrak{g}$ of $G$ written in terms of simple roots. We show that
$\mathcal{L}$ descends if $\lambda, \mu, \nu \in d\Lambda$ and $\lambda + \mu +
\nu \in \Gamma$, where $\Gamma$ is a fixed sublattice of $Q$ depending only on
the type of $\mathfrak{g}$. Moreover, $\mathcal{L}$ never descends if $\lambda
+ \mu + \nu \notin Q$.


title:
Measuring and modeling the perception of natural and unconstrained gaze
  in humans and machines

abstract:
  Humans are remarkably adept at interpreting the gaze direction of other
individuals in their surroundings. This skill is at the core of the ability to
engage in joint visual attention, which is essential for establishing social
interactions. How accurate are humans in determining the gaze direction of
others in lifelike scenes, when they can move their heads and eyes freely, and
what are the sources of information for the underlying perceptual processes?
These questions pose a challenge from both empirical and computational
perspectives, due to the complexity of the visual input in real-life
situations. Here we measure empirically human accuracy in perceiving the gaze
direction of others in lifelike scenes, and study computationally the sources
of information and representations underlying this cognitive capacity. We show
that humans perform better in face-to-face conditions compared with recorded
conditions, and that this advantage is not due to the availability of input
dynamics. We further show that humans are still performing well when only the
eyes-region is visible, rather than the whole face. We develop a computational
model, which replicates the pattern of human performance, including the finding
that the eyes-region contains on its own, the required information for
estimating both head orientation and direction of gaze. Consistent with
neurophysiological findings on task-specific face regions in the brain, the
learned computational representations reproduce perceptual effects such as the
Wollaston illusion, when trained to estimate direction of gaze, but not when
trained to recognize objects or faces.


title:
Exploring Strategies for Classification of External Stimuli Using
  Statistical Features of the Plant Electrical Response

abstract:
  Plants sense their environment by producing electrical signals which in
essence represent changes in underlying physiological processes. These
electrical signals, when monitored, show both stochastic and deterministic
dynamics. In this paper, we compute 11 statistical features from the raw
non-stationary plant electrical signal time series to classify the stimulus
applied (causing the electrical signal). By using different discriminant
analysis based classification techniques, we successfully establish that there
is enough information in the raw electrical signal to classify the stimuli. In
the process, we also propose two standard features which consistently give good
classification results for three types of stimuli - Sodium Chloride (NaCl),
Sulphuric Acid (H2SO4) and Ozone (O3). This may facilitate reduction in the
complexity involved in computing all the features for online classification of
similar external stimuli in future.


title: Probabilizing Parking Functions

abstract:
  We explore the link between combinatorics and probability generated by the
question "What does a random parking function look like?" This gives rise to
novel probabilistic interpretations of some elegant, known generating
functions. It leads to new combinatorics: how many parking functions begin with
$i$? We classify features (e.g., the full descent pattern) of parking functions
that have exactly the same distribution among parking functions as among all
functions. Finally, we develop the link between parking functions and Brownian
excursion theory to give examples where the two ensembles differ.


title: Detectability of compact binary merger macronovae

abstract:
  We study the optical and near-infrared luminosities and detectability of
radioactively powered electromagnetic transients ('macronovae') occuring in the
aftermath of binary neutron star and neutron star black hole mergers. We
explore the transients that result from the dynamic ejecta and those from
different types of wind outflows. Based on full nuclear network simulations we
calculate the resulting light curves in different wavelength bands. We
scrutinize the robustness of the results by comparing a) two different nuclear
reaction networks and b) two macronova models. We explore in particular how
sensitive the results are to the production of alpha-decaying trans-lead
nuclei. We compare two frequently used mass models: the Finite-Range Droplet
Model (FRDM) and the nuclear mass model of Duflo and Zuker (DZ31). We find that
the abundance of alpha-decaying trans-lead nuclei has a significant impact on
the observability of the resulting macronovae. For example, the DZ31 model
yields considerably larger abundances resulting in larger heating rates and
thermalization efficiencies and therefore predicts substantially brighter
macronova transients. We find that the dynamic ejecta from NSNS models can
reach peak K-band magnitudes in excess of -15 while those from NSBH cases can
reach beyond -16. Similar values can be reached by some of our wind models.
Several of our models (both wind and dynamic ejecta) yield properties that are
similar to the transient that was observed in the aftermath of the short GRB
130603B. We further explore the expected macronova detection frequencies for
current and future instruments such as VISTA, ZTF and LSST.


title: Dialogue Learning With Human-In-The-Loop

abstract:
  An important aspect of developing conversational agents is to give a bot the
ability to improve through communicating with humans and to learn from the
mistakes that it makes. Most research has focused on learning from fixed
training sets of labeled data rather than interacting with a dialogue partner
in an online fashion. In this paper we explore this direction in a
reinforcement learning setting where the bot improves its question-answering
ability from feedback a teacher gives following its generated responses. We
build a simulator that tests various aspects of such learning in a synthetic
environment, and introduce models that work in this regime. Finally, real
experiments with Mechanical Turk validate the approach.


title:
Interspecific allometric scaling of unicellular organisms as an
  evolutionary process of food chain creation

abstract:
  Metabolism of living organisms is a foundation of life. The metabolic rate
(energy production per unit time) increases slower than organisms' mass. When
this phenomenon is considered across different species, it is called
interspecific allometric scaling, whose causes are unknown. We argue that the
cause of interspecific allometric scaling is the total effect of physiological
and adaptation mechanisms inherent to organisms composing a food chain.
Together, the workings of these mechanisms are united by a primary goal of any
living creature - its successful reproduction. This primary necessity of each
organism and of the entire food chain is that common denominator, to which all
organisms adjust their metabolic rates. In this article, we consider
unicellular organisms, while the second paper studies multicellular organisms
and the entire concept in more detail. Here, using the proposed concepts and
experimentally verified growth models of five different unicellular organisms,
we obtain close to experimental findings values of allometric exponents of
0.757 for the end of growth and 0.853 for the beginning of growth. These
results comply with experimental observations and prove our theory that the
requirement of successful reproduction within the food chain is an important
factor shaping interspecific allometric scaling.


title: Cycle flows and multistabilty in oscillatory networks: an overview

abstract:
  The functions of many networked systems in physics, biology or engineering
rely on a coordinated or synchronized dynamics of its constituents. In power
grids for example, all generators must synchronize and run at the same
frequency and their phases need to appoximately lock to guarantee a steady
power flow. Here, we analyze the existence and multitude of such phase-locked
states. Focusing on edge and cycle flows instead of the nodal phases we derive
rigorous results on the existence and number of such states. Generally,
multiple phase-locked states coexist in networks with strong edges, long
elementary cycles and a homogeneous distribution of natural frequencies or
power injections, respectively. We offer an algorithm to systematically compute
multiple phase- locked states and demonstrate some surprising dynamical
consequences of multistability.


title:
Period spacing of gravity modes strongly affected by rotation. Going
  beyond the traditional approximation

abstract:
  Context. As of today, asteroseismology mainly allows us to probe the internal
rotation of stars when modes are only weakly affected by rotation using
perturbative methods. Such methods cannot be applied to rapidly rotating stars,
which exhibit complex oscillation spectra. In this context, the so-called
traditional approximation, which neglects the terms associated with the
latitudinal component of the rotation vector, describes modes that are strongly
affected by rotation. This approximation is sometimes used for interpreting
asteroseismic data, however, its domain of validity is not established yet.
  Aims. We aim at deriving analytical prescriptions for period spacings of
low-frequency gravity modes strongly affected by rotation through the full
Coriolis acceleration, which can be used to probe stellar internal structure
and rotation.
  Methods. We approximated the asymptotic theory of gravito-inertial waves in
uniformly rotating stars using ray theory described in a previous paper in the
low-frequency regime, where waves are trapped near the equatorial plane. We put
the equations of ray dynamics into a separable form and used the EBK
quantisation method to compute modes frequencies from rays.
  Results. Two spectral patterns that depend on stratification and rotation are
predicted within this new approximation: one for axisymmetric modes and one for
non-axisymmetric modes.
  Conclusions. The detection of the predicted patterns in observed oscillation
spectra would give constraints on internal rotation and chemical stratification
of rapidly rotating stars exhibiting gravity modes, such as $\gamma$ Doradus,
SPB, or Be stars. The obtained results have a mathematical form that is similar
to that of the traditional approximation, but the new approximation takes the
full Coriolis, which allows for propagation near the centre, and centrifugal
accelerations into account.


title: Learning Features of Music from Scratch

abstract:
  This paper introduces a new large-scale music dataset, MusicNet, to serve as
a source of supervision and evaluation of machine learning methods for music
research. MusicNet consists of hundreds of freely-licensed classical music
recordings by 10 composers, written for 11 instruments, together with
instrument/note annotations resulting in over 1 million temporal labels on 34
hours of chamber music performances under various studio and microphone
conditions.
  The paper defines a multi-label classification task to predict notes in
musical recordings, along with an evaluation protocol, and benchmarks several
machine learning architectures for this task: i) learning from spectrogram
features; ii) end-to-end learning with a neural net; iii) end-to-end learning
with a convolutional neural net. These experiments show that end-to-end models
trained for note prediction learn frequency selective filters as a low-level
representation of audio.


title:
Two-block Springer fibers of types C and D: a diagrammatic approach to
  Springer theory

abstract:
  We explain an elementary topological construction of the Springer
representation on the homology of (topological) Springer fibers of types C and
D in the case of nilpotent endomorphisms with two Jordan blocks. The Weyl group
and component group actions admit a diagrammatic description in terms of cup
diagrams which appear in the definition of arc algebras of types B and D. We
determine the decomposition of the representations into irreducibles and relate
our construction to classical Springer theory. As an application we obtain
presentations of the cohomology rings of all two-block Springer fibers of types
C and D. Moreover, we deduce explicit isomorphisms between the Kazhdan-Lusztig
cell modules attached to the induced trivial module and the irreducible Specht
modules in types C and D.


title:
A Statistical Index for Early Diagnosis of Ventricular Arrhythmia from
  the Trend Analysis of ECG Phase-portraits

abstract:
  In this paper, we propose a novel statistical index for the early diagnosis
of ventricular arrhythmia (VA) using the time delay phase-space reconstruction
(PSR) technique, from the electrocardiogram (ECG) signal. Patients with two
classes of fatal VA - with preceding ventricular premature beats (VPBs) and
with no VPBs have been analysed using extensive simulations. Three subclasses
of VA with VPBs viz. ventricular tachycardia (VT), ventricular fibrillation
(VF) and VT followed by VF are analyzed using the proposed technique. Measures
of descriptive statistics like mean ({\mu}), standard deviation ({\sigma}),
coefficient of variation (CV = {\sigma}/{\mu}), skewness ({\gamma}) and
kurtosis (\{beta}) in phase-space diagrams are studied for a sliding window of
10 beats of ECG signal using the box-counting technique. Subsequently, a hybrid
prediction index which is composed of a weighted sum of CV and kurtosis has
been proposed for predicting the impending arrhythmia before its actual
occurrence. The early diagnosis involves crossing the upper bound of a hybrid
index which is capable of predicting an impending arrhythmia 356 ECG beats, on
average (with 192 beats standard deviation) before its onset when tested with
32 VA patients (both with and without VPBs). The early diagnosis result is also
verified using a leave out cross-validation (LOOCV) scheme with 96.88%
sensitivity, 100% specificity and 98.44% accuracy.


title: NewsQA: A Machine Comprehension Dataset

abstract:
  We present NewsQA, a challenging machine comprehension dataset of over
100,000 human-generated question-answer pairs. Crowdworkers supply questions
and answers based on a set of over 10,000 news articles from CNN, with answers
consisting of spans of text from the corresponding articles. We collect this
dataset through a four-stage process designed to solicit exploratory questions
that require reasoning. A thorough analysis confirms that NewsQA demands
abilities beyond simple word matching and recognizing textual entailment. We
measure human performance on the dataset and compare it to several strong
neural models. The performance gap between humans and machines (0.198 in F1)
indicates that significant progress can be made on NewsQA through future
research. The dataset is freely available at
https://datasets.maluuba.com/NewsQA.


title:
Analysis of the forward and backward in time pair-separation PDFs for
  inertial particles in isotropic turbulence

abstract:
  In this paper we investigate, using theory and Direct Numerical Simulations
(DNS), the Forward In Time (FIT) and Backward In Time (BIT) Probability Density
Functions (PDFs) of the separation of inertial particle-pairs in isotropic
turbulence. In agreement with our earlier study (Bragg et al., Phys. Fluids 28,
013305 (2016)), where we compared the FIT and BIT mean-square separations, we
find that inertial particles separate much faster BIT than FIT, with the
strength of the irreversibility depending upon the final/initial separation of
the particle-pair and their Stokes number $St$. However, we also find that the
irreversibility shows up in subtle ways in the behavior of the full PDF that it
does not in the mean-square separation. In the theory, we derive new
predictions, including a prediction for the BIT/FIT PDF for ${St\geq O(1)}$,
and for final/initial separations in the dissipation regime. The prediction
shows how caustics in the particle relative velocities in the dissipation range
affect the scaling of the pair-separation PDF, leading to a PDF with an
algebraically decaying tail. The predicted functional behavior of the PDFs is
universal, in that it does not depend upon the level of intermittency in the
underlying turbulence. We also analyze the pair-separation PDFs for fluid
particles at short-times, and construct theoretical predictions using the
multifractal formalism to describe the fluid relative velocity distributions.
The theoretical and numerical results both suggest that the extreme events in
the inertial particle-pair dispersion at the small-scales are dominated by
their non-local interaction with the turbulent velocity field, rather than due
to the strong dissipation range intermittency of the turbulence itself...


title: The analysis of VERITAS muon images using convolutional neural networks

abstract:
  Imaging atmospheric Cherenkov telescopes (IACTs) are sensitive to rare
gamma-ray photons, buried in the background of charged cosmic-ray (CR)
particles, the flux of which is several orders of magnitude greater. The
ability to separate gamma rays from CR particles is important, as it is
directly related to the sensitivity of the instrument. This
gamma-ray/CR-particle classification problem in IACT data analysis can be
treated with the rapidly-advancing machine learning algorithms, which have the
potential to outperform the traditional box-cut methods on image parameters. We
present preliminary results of a precise classification of a small set of muon
events using a convolutional neural networks model with the raw images as input
features. We also show the possibility of using the convolutional neural
networks model for regression problems, such as the radius and brightness
measurement of muon events, which can be used to calibrate the throughput
efficiency of IACTs.


title:
On the construction of minimal foliations by hyperbolic surfaces on
  3-manifolds

abstract:
  We describe several methods to construct minimal foliations by hyperbolic
surfaces on closed 3-manifolds, and discuss the properties of the examples thus
obtained.


title: Whirling orbits around twirling black holes from conformal symmetry

abstract:
  Dynamics in the throat of rapidly rotating Kerr black holes is governed by an
emergent near-horizon conformal symmetry. The throat contains unstable circular
orbits at radii extending from the ISCO down to the light ring. We show that
they are related by conformal transformations to physical plunges and
osculating trajectories. These orbits have angular momentum arbitrarily higher
than that of ISCO. Using the conformal symmetry we compute analytically the
radiation produced by the physical orbits. We also present a simple formula for
the full self-force on such trajectories in terms of the self-force on circular
orbits.


title:
Multi-objective Active Control Policy Design for Commensurate and
  Incommensurate Fractional Order Chaotic Financial Systems

abstract:
  In this paper, an active control policy design for a fractional order (FO)
financial system is attempted, considering multiple conflicting objectives. An
active control template as a nonlinear state feedback mechanism is developed
and the controller gains are chosen within a multi-objective optimization (MOO)
framework to satisfy the conditions of asymptotic stability, derived
analytically. The MOO gives a set of solutions on the Pareto optimal front for
the multiple conflicting objectives that are considered. It is shown that there
is a trade-off between the multiple design objectives and a better performance
in one objective can only be obtained at the cost of performance deterioration
in the other objectives. The multi-objective controller design has been
compared using three different MOO techniques viz. Non Dominated Sorting
Genetic Algorithm-II (NSGA-II), epsilon variable Multi-Objective Genetic
Algorithm (ev-MOGA), and Multi Objective Evolutionary Algorithm with
Decomposition (MOEA/D). The robustness of the same control policy designed with
the nominal system settings have been investigated also for gradual decrease in
the commensurate and incommensurate fractional orders of the financial system.


title: Pretty good state transfer between internal nodes of paths

abstract:
  We study a continous-time quantum walk on a path graph. In this paper, we
show that, for any odd prime $p$ and positive integer $t$, the path on $2^t p -
1$ vertices admits pretty good state transfer between vertices $a$ and $n+1-a$
for each $a$ that is a multiple of $2^{t-1}$ with respect to the quantum walk
model determined by the XY-Hamiltonian. This gives the first examples of pretty
good state transfer occurring between internal vertices on a path, when it does
not occur between the extremal vertices.


title: Quantum and non-signalling graph isomorphisms

abstract:
  We introduce a two-player nonlocal game, called the $(G,H)$-isomorphism game,
where classical players can win with certainty if and only if the graphs $G$
and $H$ are isomorphic. We then define the notions of quantum and
non-signalling isomorphism, by considering perfect quantum and non-signalling
strategies for the $(G,H)$-isomorphism game, respectively. In the quantum case,
we consider both the tensor product and commuting frameworks for nonlocal
games. We prove that non-signalling isomorphism coincides with the well-studied
notion of fractional isomorphism, thus giving the latter an operational
interpretation. Second, we show that, in the tensor product framework, quantum
isomorphism is equivalent to the feasibility of two polynomial systems in
non-commuting variables, obtained by relaxing the standard integer programming
formulations for graph isomorphism to Hermitian variables. On the basis of this
correspondence, we show that quantum isomorphic graphs are necessarily
cospectral. Finally, we provide a construction for reducing linear binary
constraint system games to isomorphism games. This allows us to produce quantum
isomorphic graphs that are nevertheless not isomorphic. Furthermore, it allows
us to show that our two notions of quantum isomorphism, from the tensor product
and commuting frameworks, are in fact distinct relations, and that the latter
is undecidable. Our construction is related to the FGLSS reduction from
inapproximability literature, as well as the CFI construction.


title:
Revisiting radiative decays of $1^{+-}$ heavy quarkonia in the covariant
  light-front approach

abstract:
  We revisit the calculation of the width for the radiative decay of a $1^{+-}$
heavy $Q \bar Q$ meson via the channel $1^{+-} \to 0^{-+} +\gamma$ in the
covariant light-front quark model. We carry out the reduction of the
light-front amplitude in the non-relativistic limit, explicitly computing the
leading and next-to-leading order relativistic corrections. This shows the
consistency of the light-front approach with the non-relativistic formula for
this electric dipole transition. Furthermore, the theoretical uncertainty in
the predicted width is studied as a function of the inputs for the heavy quark
mass and wavefunction structure parameter. We analyze the specific decays
$h_{c}(1P) \to \eta_{c}(1S) + \gamma$ and $h_{b}(1P) \to \eta_{b}(1S) +
\gamma$. We compare our results with experimental data and with other
theoretical predictions from calculations based on non-relativistic models and
their extensions to include relativistic effects, finding reasonable agreement.


title: Localization effects on magnetotransport of a disordered Weyl semimetal

abstract:
  We study magnetotransport in a disordered Weyl semimetal taking into account
localization effects exactly. In the vicinity of a Weyl node, a single chiral
Landau level coexists with a number of conventional non-chiral levels. Disorder
scattering mixes these topologically different modes leading to peculiar
localization effects. We derive the average conductance as well as the full
distribution function of transmission probabilities along the field direction.
Remarkably, we find that localization of the non-chiral modes is greatly
enhanced in a strong magnetic field with the typical localization length
scaling as $1/B$. Technically, we use the non-linear sigma-model formalism with
a topological term describing the chiral states. The problem is solved exactly
by mapping to an equivalent transfer matrix Hamiltonian.


title: Hedgehogs in higher dimensions and their applications

abstract:
  In this paper we study the dynamics of germs of holomorphic diffeomorphisms
of $(\mathbb{C}^{n},0)$ with a fixed point at the origin with exactly one
neutral eigenvalue. We prove that the map on any local center manifold of $0$
is quasiconformally conjugate to a holomorphic map and use this to transport
results from one complex dimension to higher dimensions.


title:
Determining the CP nature of spin-0 mediators in associated production
  of dark matter and $t \bar t$ pairs

abstract:
  In the framework of spin-0 $s$-channel simplified models, we explore the
possibility of assessing the structure of dark matter interactions through the
associate production of dark matter and $t\bar{t}$ pairs. To this purpose,
final states with two leptons are considered and the kinematic properties of
the dilepton system is studied. We develop a realistic analysis strategy and
provide a detailed evaluation of the achievable sensitivity for the dark matter
signal assuming integrated luminosities of $300 \, {\rm fb}^{-1}$ and $3 \,
{\rm ab}^{-1}$ at the 14 TeV LHC. Furthermore, upper limits on the mediator
masses for which the two different CP hypotheses can be distinguished are
derived. The obtained limits on the signal strengths are finally translated
into constraints on the parameter space of two spin-0 simplified models
including a scenario with an extended Higgs sector.


title:
Split-Brain Autoencoders: Unsupervised Learning by Cross-Channel
  Prediction

abstract:
  We propose split-brain autoencoders, a straightforward modification of the
traditional autoencoder architecture, for unsupervised representation learning.
The method adds a split to the network, resulting in two disjoint sub-networks.
Each sub-network is trained to perform a difficult task -- predicting one
subset of the data channels from another. Together, the sub-networks extract
features from the entire input signal. By forcing the network to solve
cross-channel prediction tasks, we induce a representation within the network
which transfers well to other, unseen tasks. This method achieves
state-of-the-art performance on several large-scale transfer learning
benchmarks.


title:
A Cyclic Orbifold Theory for Holomorphic Vertex Operator Algebras and
  Applications

abstract:
  In this thesis we develop an orbifold theory for a finite, cyclic group $G$
acting on a suitably regular, holomorphic vertex operator algebra $V$. To this
end we describe the fusion algebra of the fixed-point vertex operator
subalgebra $V^G$ and show that $V^G$ has group-like fusion. Then we solve the
extension problem for vertex operator algebras with group-like fusion.
  We use these results to construct five new holomorphic vertex operator
algebras of central charge 24 as lattice orbifolds, contributing to the
classification of the $V_1$-structures of suitably regular, holomorphic vertex
operator algebras of central charge 24.
  As another application we present the BRST construction of ten
Borcherds-Kac-Moody algebras whose denominator identities are completely
reflective automorphic products of singular weight.


title:
Simulation studies on the design of optimum PID controllers to suppress
  chaotic oscillations in a family of Lorenz-like multi-wing attractors

abstract:
  Multi-wing chaotic attractors are highly complex nonlinear dynamical systems
with higher number of index-2 equilibrium points. Due to the presence of
several equilibrium points, randomness and hence the complexity of the state
time series for these multi-wing chaotic systems is much higher than that of
the conventional double-wing chaotic attractors. A real-coded Genetic Algorithm
(GA) based global optimization framework has been adopted in this paper as a
common template for designing optimum Proportional-Integral-Derivative (PID)
controllers in order to control the state trajectories of four different
multi-wing chaotic systems among the Lorenz family viz. Lu system, Chen system,
Rucklidge (or Shimizu Morioka) system and Sprott-1 system. Robustness of the
control scheme for different initial conditions of the multi-wing chaotic
systems has also been shown.


title: Mott-hadron resonance gas and lattice QCD thermodynamics

abstract:
  A unified equation of state for quark-hadron matter is presented in the
generalized Beth-Uhlenbeck form. It follows from a $\Phi-$derivable approach to
the thermodynamic potential where the ansatz for the $\Phi$ functional contains
all 2PI diagrams at two-loop order formed with quark cluster Green's functions
for quark, diquark, meson and baryon propagators. We present numerical results
using an effective model for the generic behaviour of hadron masses and phase
shifts at finite temperature which shares basic features with recent
developments within the PNJL model for correlations in quark matter. We obtain
the transition between a hadron resonance gas phase and the quark gluon plasma
where the Mott dissociation of hadrons is encoded in the hadronic phase shifts.
The resulting thermodynamics is in very good agreement with recent lattice QCD
simulations.


title:
Challenges in Cosmology from the Big Bang to Dark Energy, Dark Matter
  and Galaxy Formation

abstract:
  I review the current status of Big Bang Cosmology, with emphasis on current
issues in dark matter, dark energy, and galaxy formation. These topics motivate
many of the current goals of experimental cosmology which range from targeting
the nature of dark energy and dark matter to probing the epoch of the first
stars and galaxies.


title:
Dynamic zero modes of Dirac fermions and competing singlet phases of
  antiferromagnetic order

abstract:
  In quantum spin systems, singlet phases often develop in the vicinity of an
antiferromagnetic order. Typical settings for such problems arise when
itinerant fermions are also present. In this work, we develop a theoretical
framework for addressing such competing orders in an itinerant system,
described by Dirac fermions strongly coupled to an O(3) nonlinear sigma model.
We focus on two spatial dimensions, where upon disordering the
antiferromagnetic order by quantum fluctuations the singular tunneling events
also known as (anti)hedgehogs can nucleate competing singlet orders in the
paramagnetic phase. In the presence of an isolated hedgehog configuration of
the nonlinear sigma model field, we show that the fermion determinant vanishes
as the dynamic Euclidean Dirac operator supports fermion zero modes of definite
chirality. This provides a topological mechanism for suppressing the tunneling
events. Using the methodology of quantum chromodynamics, we evaluate the
fermion determinant in the close proximity of magnetic quantum phase
transition, when the antiferromagnetic order parameter field can be described
by a dilute gas of hedgehogs and antihedgehogs. We show how the precise nature
of emergent singlet order is determined by the overlap between dynamic fermion
zero modes of opposite chirality, localized on the hedgehogs and antihedgehogs.
For a Kondo-Heisenberg model on the honeycomb lattice, we demonstrate the
competition between spin Peierls order and Kondo singlet formation, thereby
elucidating its global phase diagram. We also discuss other physical problems
that can be addressed within this general framework.

categories: cond-mat.str-el cond-mat.dis-nn cond-mat.stat-mech hep-th


title:
A Search for Additional Bodies in the GJ 1132 Planetary System from 21
  Ground-based Transits and a 100 Hour Spitzer Campaign

abstract:
  We present the results of a search for additional bodies in the GJ 1132
system through two methods: photometric transits and transit timing variations
of the known planet. We collected 21 transit observations of GJ 1132b with the
MEarth-South array since 2015. We obtained 100 near-continuous hours of
observations with the $Spitzer$ Space Telescope, including two transits of GJ
1132b and spanning 60\% of the orbital phase of the maximum period at which
bodies coplanar with GJ 1132b would pass in front of the star. We exclude
transits of additional Mars-sized bodies, such as a second planet or a moon,
with a confidence of 99.7\%. When we combine the mass estimate of the star
(obtained from its parallax and apparent $K_s$ band magnitude) with the stellar
density inferred from our high-cadence $Spitzer$ light curve (assuming zero
eccentricity), we measure the stellar radius of GJ 1132 to be
$0.2105^{+0.0102}_{-0.0085} R_\odot$, and we refine the radius measurement of
GJ 1132b to $1.130 \pm 0.056 R_\oplus$. Combined with HARPS RV measurements, we
determine the density of GJ 1132b to be $6.2 \pm 2.0$\ g cm$^{-3}$, with the
mass determination dominating this uncertainty. We refine the ephemeris of the
system and find no evidence for transit timing variations, which would be
expected if there was a second planet near an orbital resonance with GJ 1132b.


title:
Statistical physics approaches to subnetwork dynamics in biochemical
  systems

abstract:
  We apply a Gaussian variational approximation to model reduction in large
biochemical networks of unary and binary reactions. We focus on a small subset
of variables (subnetwork) of interest, e.g. because they are accessible
experimentally, embedded in a larger network (bulk). The key goal is to write
dynamical equations reduced to the subnetwork but still retaining the effects
of the bulk. As a result, the subnetwork-reduced dynamics contains a memory
term and an extrinsic noise term with non-trivial temporal correlations. We
first derive expressions for this memory and noise in the linearized (Gaussian)
dynamics and then use a perturbative power expansion to obtain first order
nonlinear corrections. For the case of vanishing intrinsic noise, our
description is explicitly shown to be equivalent to projection methods up to
quadratic terms, but it is applicable also in the presence of stochastic
fluctuations in the original dynamics. An example from the Epidermal Growth
Factor Receptor (EGFR) signalling pathway is provided to probe the increased
prediction accuracy and computational efficiency of our method.

categories: physics.chem-ph cond-mat.dis-nn cond-mat.stat-mech q-bio.MN


title: Asymptotically Good Convolutional Codes

abstract:
  In this paper, we construct new sequences of asymptotically good
convolutional codes. These sequences are obtained from sequences of transitive,
self-orthogonal and self-dual block codes that attain the Tsfasman-Vladut-Zink
bound. Furthermore, by applying the techniques of expanding, extending,
puncturing, direct sum, the |u|u+v| construction and the product code
construction to these block codes, we construct more new sequences of
asymptotically good convolutional codes. Additionally, we show that the
proposed construction method presented here also works when applied for all
sequences of good block codes where lim kj/nj and lim dj/nj exist.


title: Kaehler differentials for fat point schemes in P^1xP^1

abstract:
  Let $X$ be a set of $K$-rational points in $P^1 \times P^1$ over a field $K$
of characteristic zero, let $Y$ be a fat point scheme supported at $ X$, and
let $R_Y$ be the bihomogeneus coordinate ring of $Y$. In this paper we
investigate the module of Kaehler differentials $\Omega^1_{R_Y/K}$. We describe
this bigraded $R_Y$-module explicitly via a homogeneous short exact sequence
and compute its Hilbert function in a number of special cases, in particular
when the support $X$ is a complete intersection or an almost complete
intersection in $P^1 \times P^1$. Moreover, we introduce a Kaehler different
for $Y$ and use it to characterize reduced fat point schemes in $P^1 \times
P^1$ having the Cayley-Bacharach property.


title:
The K2 Galactic Archaeology Program Data Release 1: Asteroseismic
  results from Campaign 1

abstract:
  NASA's K2 mission is observing tens of thousands of stars along the ecliptic,
providing data suitable for large scale asteroseismic analyses to inform
galactic archaeology studies. Its first campaign covered a field near the north
galactic cap, a region never covered before by large asteroseismic-ensemble
investigations, and was therefore of particular interest for exploring this
part of our Galaxy. Here we report the asteroseismic analysis of all stars
selected by the K2 Galactic Archaeology Program during the mission's "North
Galactic Cap" campaign 1. Our consolidated analysis uses six independent
methods to measure the global seismic properties, in particular the large
frequency separation, and the frequency of maximum power. From the full target
sample of 8630 stars we find about 1200 oscillating red giants, a number
comparable with estimates from galactic synthesis modeling. Thus, as a valuable
by-product we find roughly 7500 stars to be dwarfs, which provide a sample well
suited for galactic exoplanet occurrence studies because they originate from
our simple and easily reproducible selection function. In addition, to
facilitate the full potential of the data set for galactic archaeology we
assess the detection completeness of our sample of oscillating red giants. We
find the sample is at least near complete for stars with 40 < numax/microHz <
270, and numax_detec < 2.6*1e6 * 2e-Kp microHz. There is a detection bias
against helium core burning stars with numax ~ 30 microHz, affecting the number
of measurements of DeltaNu and possibly also numax. Although we can detect
oscillations down to Kp = 15, our campaign 1 sample lacks enough faint giants
to assess the detection completeness for stars fainter than Kp ~ 14.5.


title: Magnetic field evolution in tidal disruption events

abstract:
  When a star gets tidally disrupted by a supermassive black hole, its magnetic
field is expected to pervade its debris. In this paper, we study this process
via smoothed particle magnetohydrodynamical simulations of the disruption and
early debris evolution including the stellar magnetic field. As the gas
stretches into a stream, we show that the magnetic field evolution is strongly
dependent on its orientation with respect to the stretching direction. In
particular, an alignment of the field lines with the direction of stretching
induces an increase of the magnetic energy. For disruptions happening well
within the tidal radius, the star compression causes the magnetic field
strength to sharply increase by an order of magnitude at the time of pericentre
passage. If the disruption is partial, we find evidence for a dynamo process
occurring inside the surviving core due to the formation of vortices. This
causes an amplification of the magnetic field strength by a factor of $\sim
10$. However, this value represents a lower limit since it increases with
numerical resolution. For an initial field strength of 1 G, the magnetic field
never becomes dynamically important. Instead, the disruption of a star with a
strong 1 MG magnetic field produces a debris stream within which magnetic
pressure becomes similar to gas pressure a few tens of hours after disruption.
If the remnant of one or multiple partial disruptions is eventually fully
disrupted, its magnetic field could be large enough to magnetically power the
relativistic jet detected from Swift J1644+57. Magnetized streams could also be
significantly thickened by magnetic pressure when it overcomes the confining
effect of self-gravity.


title:
Spherically-symmetric, cold collapse: the exact solutions and a
  comparison with self-similar solutions

abstract:
  We present the exact solutions for the collapse of a spherically-symmetric,
cold (i.e., pressureless) cloud under its own self-gravity, valid for arbitrary
initial density profiles and not restricted to the realm of self-similarity.
These solutions exhibit a number of remarkable features, including the
self-consistent formation of and subsequent accretion onto a central point
mass. A number of specific examples are provided, and we show that Penston's
solution of pressureless, self-similar collapse is recovered for polytropic
density profiles; importantly, however, we demonstrate that the time over which
this solution holds is fleetingly narrow, implying that much of the collapse
proceeds non-self-similarly. We show that our solutions can naturally
incorporate turbulent pressure support, and we investigate the evolution of
overdensities -- potentially generated by such turbulence -- as the collapse
proceeds. Finally, we analyze the evolution of the angular velocity and
magnetic fields in the limit that their dynamical influence is small, and we
recover exact solutions for these quantities. Our results may provide important
constraints on numerical models that attempt to elucidate the details of
protostellar collapse when the initial conditions are far less idealized.


title: The photo-philic QCD axion

abstract:
  We propose a framework in which the QCD axion has an exponentially large
coupling to photons, relying on the "clockwork" mechanism. We discuss the
impact of present and future axion experiments on the parameter space of the
model. In addition to the axion, the model predicts a large number of
pseudo-scalars which can be light and observable at the LHC. In the most
favorable scenario, axion Dark Matter will give a signal in multiple axion
detection experiments and the pseudo-scalars will be discovered at the LHC,
allowing to determine most of the parameters of the model.


title: CheckMATE 2: From the model to the limit

abstract:
  We present the latest developments to the CheckMATE program that allows
models of new physics to be easily tested against the recent LHC data. To
achieve this goal, the core of CheckMATE now contains over 60 LHC analyses of
which 12 are from the 13 TeV run. The main new feature is that CheckMATE 2 now
integrates the Monte Carlo event generation via Madgraph and Pythia 8. This
allows users to go directly from a SLHA file or UFO model to the result of
whether a model is allowed or not. In addition, the integration of the event
generation leads to a significant increase in the speed of the program. Many
other improvements have also been made, including the possibility to now
combine signal regions to give a total likelihood for a model.


title: ALMA Deep Field in SSA22: Source Catalog and Number Counts

abstract:
  We present results from a deep 2'x3' (comoving scale of 3.7 Mpc x 5.5 Mpc at
z=3) survey at 1.1 mm taken with the Atacama Large Millimeter/submillimeter
Array (ALMA) in the SSA22 field. We observe the core region of a z = 3.09
protocluster, achieving a typical rms sensitivity of 60 micro-Jy/beam at a
spatial resolution of 0".7. We detect 18 robust ALMA sources at a
signal-to-noise ratio (SNR) > 5. Comparison between the ALMA map and a 1.1 mm
map taken with the AzTEC camera on the Atacama Submillimeter Telescope
Experiment (ASTE) indicates that three submillimeter sources discovered by the
AzTEC/ASTE survey are resolved into eight individual submillimeter galaxies
(SMGs) by ALMA. At least ten of our 18 ALMA SMGs have spectroscopic redshifts
of z = 3.09, placing them in the protocluster. This shows that a number of
dusty starburst galaxies are forming simultaneously in the core of the
protocluster. The nine brightest ALMA SMGs with SNR > 10 have a median
intrinsic angular size of 0".32+0".13-0".06 (2.4+1.0-0.4 physical kpc at z =
3.09), which is consistent with previous size measurements of SMGs in other
fields. As expected the source counts show a possible excess compared to the
counts in the general fields at S_1.1mm >= 1.0 mJy due to the protocluster. Our
contiguous mm mapping highlights the importance of large-scale structures on
the formation of dusty starburst galaxies.


title:
The Complete Infrared View of Active Galactic Nuclei from the 70-month
  Swift/BAT Catalog

abstract:
  We systematically investigate the near- (NIR) to far-infrared (FIR)
photometric properties of a nearly complete sample of local active galactic
nuclei (AGN) detected in the Swift/Burst Alert Telescope (BAT) all-sky ultra
hard X-ray (14-195 keV) survey. Out of 606 non-blazar AGN in the Swift/BAT
70-month catalog at high galactic latitude of $|b|>10^{\circ}$, we obtain IR
photometric data of 604 objects by cross-matching the AGN positions with
catalogs from the WISE, AKARI, IRAS, and Herschel infrared observatories. We
find a good correlation between the ultra-hard X-ray and mid-IR (MIR)
luminosities over five orders of magnitude ($41 < \log (L_{14-195}/{\rm
erg}~{\rm s}^{-1})< 46$). Informed by previous measures of the intrinsic
spectral energy distribution of AGN, we find FIR pure-AGN candidates whose FIR
emission is thought to be AGN-dominated with low starformation activity. We
demonstrate that the dust covering factor decreases with the bolometric AGN
luminosity, confirming the luminosity-dependent unified scheme. We also show
that the completeness of the WISE color-color cut in selecting Swift/BAT AGN
increases strongly with 14-195 keV luminosity.


title:
The Stellar Initial Mass Function in Early-Type Galaxies from Absorption
  Line Spectroscopy. III. Radial Gradients

abstract:
  There is good evidence that the centers of massive early-type galaxies have a
bottom-heavy stellar initial mass function (IMF) compared to the IMF of the
Milky Way. Here we study the radial variation of the IMF within such galaxies,
using a combination of high quality Keck spectroscopy and a new suite of
stellar population synthesis models that cover a wide range in metallicity. As
in the previous studies in this series, the models are fitted directly to the
spectra and treat all elemental abundance ratios as free parameters. Using
newly obtained spectroscopy for six galaxies, including deep data extending to
~1Re for the galaxies NGC1407, NGC1600, and NGC2695, we find that the IMF
varies strongly with galactocentric radius. For all six galaxies the IMF is
bottom-heavy in the central regions, with average mass-to-light ratio
"mismatch" parameter a~2.5 at R=0. The IMF rapidly becomes more bottom-light
with increasing radius, flattening off near the Milky Way value (a~1.1) at
R>0.4Re. A consequence is that the luminosity-weighted average IMF depends on
the measurement aperture: within R=Re we find <a>=1.3-1.5, consistent with
recent lensing and dynamical results from SLACS and ATLAS-3D. Our results are
also consistent with several earlier studies that were based on analyses of
radial gradients of line indices. The observed IMF gradients support galaxy
formation models in which the central regions of massive galaxies had a
different formation history than their outer parts. Finally, we make use of the
high signal-to-noise central spectra of NGC1407 and NGC2695 to demonstrate how
we can disentangle IMF effects and abundance effects.


title:
Extinction Correction Significantly Influences the Estimate of
  Ly$\alpha$ Escape Fraction

abstract:
  The Ly$\alpha$ escape fraction is a key measure to constrain the neutral
state of the intergalactic medium and then to understand how the universe was
fully reionized. We combine deep narrowband imaging data from the custom-made
filter NB393 and the $H_{2}S$1 filter centered at 2.14 $\mu$m to examine the
Ly$\alpha$ emitters and H$\alpha$ emitters at the same redshift $z=2.24$. The
combination of these two populations allows us to determine the Ly$\alpha$
escape fraction at $z=2.24$. Over an area of 383 arcmin$^{2}$ in the Extended
Chandra Deep Field South (ECDFS), 124 Ly$\alpha$ emitters are detected down to
NB393 = 26.4 mag at the 5$\sigma$ level, and 56 H$\alpha$ emitters come from
An14. Of these, four have both Ly$\alpha$ and H$\alpha$ emissions (LAHAEs). We
measure the individual/volumetric Ly$\alpha$ escape fraction by comparing the
observed Ly$\alpha$ luminosity/luminosity density to the extinction-corrected
H$\alpha$ luminosity/luminosity density. We revisit the extinction correction
for H$\alpha$ emitters using the Galactic extinction law with the color excess
for nebular emission. We also adopt the Calzetti extinction law together with
an identical color excess for stellar and nebular regions to explore how the
uncertainties in extinction correction affect our results. In both cases, an
anti-correlation between the Ly$\alpha$ escape fraction and dust attenuation is
found among the LAHAEs, suggesting that dust absorption is responsible for the
suppression of the escaping Ly$\alpha$ photons. However, the estimated
Ly$\alpha$ escape fraction of individual LAHAEs varies up to ~3 percentage
points between the two methods of extinction correction. We find the global
Ly$\alpha$ escape fraction at $z=2.24$ to be ($3.7\pm1.4$)% in the ECDFS. The
variation in the color excess of the extinction causes a discrepancy of ~1
percentage point in the global Ly$\alpha$ escape fraction.


title: An estimate of the DM profile in the Galactic bulge region

abstract:
  We present an analysis of the mass distribution in the region of the Galactic
bulge, which leads to constraints on the total amount and distribution of Dark
Matter (DM) therein. Our results -based on the dynamical measurement of the
BRAVA collaboration- are quantitatively compatible with those of a recent
analysis, and generalised to a vaste sample of observationally inferred
morphologies of the stellar components in the region of the Galactic bulge. By
fitting the inferred DM mass to a generalised NFW profile, we find that cores
(index gamma smaller than 0.6) are forbidden only for very light configurations
of the bulge, and that cusps (index gamma bigger than 1.2) are allowed, but not
necessarily preferred. Interestingly, we find that the results for the bulge
region are compatible with those obtained with dynamical methods (based on the
rotation curve) applied to outer regions of the Milky Way, for all morphologies
adopted. We find that the uncertainty on the shape of the stellar morphology
heavily affects the determination of the DM distribution in the bulge region,
which is gravitationally dominated by baryons, adding up to the uncertainty on
its normalization. The combination of the two hinders the actual possibility to
infer sound conclusions about the distribution of DM in the region of the
Galactic bulge, and only future observations of the stellar census and dynamics
in this region will bring us closer to a quantitatively more definite answer.


title:
Testing $\Lambda$CDM at the lowest redshifts with SN Ia and galaxy
  velocities

abstract:
  Peculiar velocities of objects in the nearby universe are correlated due to
the gravitational pull of large-scale structure. By measuring these velocities,
we have a unique opportunity to test the cosmological model at the lowest
redshifts. We perform this test, using current data to constrain the amplitude
of the "signal" covariance matrix describing the velocities and their
correlations. We consider a new, well-calibrated "Supercal" set of low-redshift
SNe Ia as well as a set of distances derived from the fundamental plane
relation of 6dFGS galaxies. Analyzing the SN and galaxy data separately, both
results are consistent with the peculiar velocity signal of our fiducial
$\Lambda$CDM model, ruling out the noise-only model with zero peculiar
velocities at greater than $7\sigma$ (SNe) and $8\sigma$ (galaxies). When the
two data sets are combined appropriately, the precision of the test increases
slightly, resulting in a constraint on the signal amplitude of $A =
1.05_{-0.21}^{+0.25}$, where $A = 1$ corresponds to our fiducial model.
Equivalently, we report an 11% measurement of the product of the growth rate
and amplitude of mass fluctuations evaluated at $z_\text{eff} = 0.02$, $f
\sigma_8 = 0.428_{-0.045}^{+0.048}$, valid for our fiducial $\Lambda$CDM model.
We explore the robustness of the results to a number of conceivable variations
in the analysis and find that individual variations shift the preferred signal
amplitude by less than ${\sim}0.5\sigma$. We briefly discuss our Supercal SN Ia
results in comparison with our previous results using the JLA compilation.


title: Emergent phenomena and partonic structure in hadrons

abstract:
  Modern facilities are poised to tackle fundamental questions within the
Standard Model, aiming to reveal the nature of confinement, its relationship to
dynamical chiral symmetry breaking (DCSB) - the origin of visible mass - and
the connection between these two, key emergent phenomena. There is strong
evidence to suggest that they are intimately connected with the appearance of
momentum-dependent masses for gluons and quarks in QCD, which are large in the
infrared: $m_g \sim 500\,$MeV and $M_q\sim 350\,$MeV. DCSB, expressed in the
dynamical generation of a dressed-quark mass, has an enormous variety of
verifiable consequences, including an enigmatic result that the properties of
the (almost) massless pion are the cleanest expression of the mechanism which
is responsible for almost all the visible mass in the Universe. This
contribution explains that these emergent phenomena are expressed with
particular force in the partonic structure of hadrons, e.g. in valence-quark
parton distribution amplitudes and functions, and, consequently, in numerous
hadronic observables, so that we are now in a position to exhibit the
consequences of confinement and DCSB in a wide range of hadron observables,
opening the way to empirical verification of their expression in the Standard
Model.


title: Millimeter-Wave Line Ratios and Sub-beam Volume Density Distributions

abstract:
  We explore the use of mm-wave emission line ratios to trace molecular gas
density when observations integrate over a wide range of volume densities
within a single telescope beam. For observations targeting external galaxies,
this case is unavoidable. Using a framework similar to that of Krumholz and
Thompson (2007), we model emission for a set of common extragalactic lines from
lognormal and power law density distributions. We consider the median density
of gas producing emission and the ability to predict density variations from
observed line ratios. We emphasize line ratio variations, because these do not
require knowing the absolute abundance of our tracers. Patterns of line ratio
variations have the prospect to illuminate the high-end shape of the density
distribution, and to capture changes in the dense gas fraction and median
volume density. Our results with and without a high density power law tail
differ appreciably; we highlight better knowledge of the PDF shape as an
important area. We also show the implications of sub-beam density distributions
for isotopologue studies targeting dense gas tracers. Differential excitation
often implies a significant correction to the naive case. We provide tabulated
versions of many of our results, which can be used to interpret changes in
mm-wave line ratios in terms of changes in the underlying density
distributions.


title: Finding a faint polarized signal in wide-band radio data

abstract:
  We develop two algorithms, based on maximum likelihood (ML) inference, for
estimating the parameters of polarized radio sources which emit at a single
rotation measure (RM), e.g., pulsars. These algorithms incorporate the flux
density spectrum of the source, either a power law or a scaled version of the
Stokes I spectrum, and a variation in sensitivity across the observing band. We
quantify the detection significance and measurement uncertainties in the fitted
parameters, and we derive weighted versions of the RM synthesis algorithm
which, under certain conditions, maximize the likelihood. We use Monte Carlo
simulations to compare injected and recovered source parameters for a range of
signal-to-noise ratios, investigate the quality of standard methods for
estimating measurement uncertainties, and search for statistical biases. These
simulations consider one frequency band each for the Australia Telescope
Compact Array (ATCA), the Square Kilometre Array (SKA), and the Low Frequency
Array (LOFAR). We find that results obtained for one frequency band cannot be
easily generalized, and that methods which were developed in the past for
correcting bias in individual frequency channels do not apply to wide-band data
sets. The standard method for estimating the measurement uncertainty in RM is
not accurate for sources with non-zero spectral indices. Furthermore, dividing
Stokes Q and U by Stokes I to correct for spectral index effects, in
combination with RM synthesis, does not maximize the likelihood.


title: Boosted Dark Matter at the Deep Underground Neutrino Experiment

abstract:
  We investigate the detection prospects of a non-standard dark sector in the
context of boosted dark matter. We consider a scenario where two stable
particles have a large mass difference and the heavier particle accounts for
most of dark matter in our current universe. The heavier candidate is assumed
to have no interaction with the standard model particles at tree-level, hence
evading existing constraints. Although subdominant, the lighter dark matter
particles are efficiently produced via pair-annihilation of the heavier ones in
the center of the Galaxy or the Sun. The large Lorentz boost enables detection
of the non-minimal dark sector in large volume terrestrial experiments via
exchange of a light dark photon with electrons or nuclei. Various experiments
designed for neutrino physics and proton decay are examined in detail,
including Super-K and Hyper-K. In this study, we focus on the sensitivity of
the far detector at the Deep Underground Neutrino Experiment for boosted dark
matter produced in the center of the Sun, and compare our findings with recent
results for boosted dark matter produced in the galactic center.


title: A new Generation of Standard Solar Models

abstract:
  We compute a new generation of standard solar models (SSMs) that includes
recent updates on some important nuclear reaction rates and a more consistent
treatment of the equation of state. Models also include a novel and flexible
treatment of opacity uncertainties based on opacity kernels, required in the
light of recent theoretical and experimental works on radiative opacity. Two
large sets of SSMs, each based on a different canonical set of solar abundances
with high and low metallicity (Z), are computed to determine model
uncertainties and correlations among different observables. We present detailed
comparisons of high- and low-Z models against different ensembles of solar
observables including solar neutrinos, surface helium abundance, depth of
convective envelope and sound speed profile. A global comparison, including all
observables, yields a p-value of 2.7$\sigma$ for the high-Z model and
4.7$\sigma$ for the low-Z one. When the sound-speed differences in the narrow
region of $0.65 < r/R_{sun} < 0.70$ are excluded from the analysis, results are
0.9$\sigma$ and 3.0$\sigma$ for high- and low-Z models respectively. These
results show that: high-Z models agree well with solar data but have a
systematic problem right below the bottom of the convective envelope linked to
steepness of molecular weight and temperature gradients, and that low-Z models
lead to a much more general disagreement with solar data. We also show that,
while simple parametrizations of opacity uncertainties can strongly alleviate
the solar abundance problem, they are insufficient to substantially improve the
agreement of SSMs with helioseismic data beyond that obtained for high-Z models
due to the intrinsic correlations of theoretical predictions. All the detailed
information of the new solar models, can be found online:
http://www.ice.cat/personal/aldos/Solar_Data.html


title: Exploring the nearly degenerate stop region with sbottom decays

abstract:
  A light stop with mass almost degenerate with the lightest neutralino has
important connections with both naturalness and dark matter relic abundance.
This region is also very hard to probe at colliders. In this paper, we
demonstrate the potential of searching for such stop particles at the LHC from
sbottom decays, focusing on two channels with final states $2\ell+E^{\rm
miss}_{\rm T}$ and $1b1\ell+E^{\rm miss}_{\rm T}$. We found that, if the
lightest sbottom has mass around or below 1 TeV and has a significant branching
ratio to decay to stop and $W$ ($\tilde{b} \to \tilde{t}\,W$), a stop almost
degenerate with neutralino can be excluded up to about 500-600 GeV at the 13
TeV LHC with $300\,{\rm fb}^{-1}$ data. The searches we propose are
complementary to other SUSY searches at the LHC and could have the best
sensitivity to the stop-bino coannihilation region. Since they involve final
states which have already been used in LHC searches, a reinterpretation of the
search results already has sensitivity. Further optimization could deliver the
full potential of these channels.


title:
Searches for correlation between UHECR events and high-energy gamma-ray
  Fermi-LAT data

abstract:
  The astrophysical sources responsible for ultra high-energy cosmic rays
(UHECRs) continue to be one of the most intriguing mysteries in astrophysics.
We present a comprehensive search for correlations between high-energy
($\gtrapprox 1$ GeV) gamma-ray events from the Fermi Large Area Telescope (LAT)
and UHECRs ($\gtrapprox 60$ EeV) detected by the Telescope Array and the Pierre
Auger Observatory. We perform two separate searches. First, we conduct a
standard cross-correlation analysis between the arrival directions of 148
UHECRs and 360 gamma-ray sources in the Second Catalog of Hard Fermi-LAT
sources (2FHL). Second, we search for a possible correlation between UHECR
directions and unresolved Fermi-LAT gamma-ray emission. For the latter, we use
three different methods: a stacking technique with both a model-dependent and
model-independent background estimate, and a cross-correlation function
analysis. We also test for statistically significant excesses in gamma rays
from signal regions centered on Cen A and the Telescope Array hotspot. No
significant correlation is found in any of the analyses performed, except a
weak ($\lessapprox 2\sigma$) hint of signal with the correlation function
method on scales $\sim 1^\circ$. Upper limits on the flux of possible power-law
gamma-ray sources of UHECRs are derived.


title: Odd Azimuthal Anisotropy of the Glasma for pA Scattering

abstract:
  In this paper we analytically extract the odd azimuthal anisotropy in the
Classical Yang-Mills equations for the Glasma for pA collisions. We compute the
first non-trivial term in the expansion of the proton sources of color charge.
The computation is valid in the limit of a large nucleus when the produced
particle momenta are larger than the saturation momentum of the proton.


title: Characterizing the properties of cluster precursors in the MALT90 survey

abstract:
  In the Milky Way there are thousands of stellar clusters each harboring from
a hundred to a million stars. Although clusters are common, the initial
conditions of cluster formation are still not well understood. To determine the
processes involved in the formation and evolution of clusters it is key to
determine the global properties of cluster-forming clumps in their earliest
stages of evolution. Here, we present the physical properties of 1,244 clumps
identified from the MALT90 survey. Using the dust temperature of the clumps as
a proxy for evolution we determined how the clump properties change at
different evolutionary stages. We find that less-evolved clumps exhibiting dust
temperatures lower than 20 K have higher densities and are more gravitationally
bound than more-evolved clumps with higher dust temperatures. We also
identified a sample of clumps in a very early stage of evolution, thus
potential candidates for high-mass star-forming clumps. Only one clump in our
sample has physical properties consistent with a young massive cluster
progenitor, reinforcing the fact that massive proto-clusters are very rare in
the Galaxy.


title:
Transport formulas for multi-component plasmas within the effective
  potential theory framework

abstract:
  The recently proposed effective potential theory [Phys. Rev. Lett. 110,
235001 (2013)] allows evaluating transport in coupled plasmas with the
well-developed formalisms for systems with binary collisions. To facilitate
practical implementation of this concept in fluid models of multi-component
plasmas, compact expressions for the transport coefficients in terms the
generalized Coulomb logarithms are summarized from existing prescriptions. For
weakly coupled plasmas, characterized by Debye-shielded Coulomb interaction
potential, expressions become fully analytical. In coupled plasmas the
generalized Coulomb logarithms need to be evaluated numerically. Routines
implementing the described formalisms are included as supplemental material.


title:
The GAPS Programme with HARPS-N@TNG XII: Characterization of the
  planetary system around HD108874

abstract:
  In order to understand the observed physical and orbital diversity of
extrasolar planetary systems, a full investigation of these objects and of
their host stars is necessary. Within this field, one of the main purposes of
the GAPS observing project with HARPS-N@TNG is to provide a more detailed
characterisation of already known systems. In this framework we monitored the
star, hosting two giant planets, HD108874, with HARPS-N for three years in
order to refine the orbits, to improve the dynamical study and to search for
additional low-mass planets in close orbits. We subtracted the radial velocity
(RV) signal due to the known outer planets, finding a clear modulation of 40.2
d period. We analysed the correlation between RV residuals and the activity
indicators and modelled the magnetic activity with a dedicated code. Our
analysis suggests that the 40.2 d periodicity is a signature of the rotation
period of the star. A refined orbital solution is provided, revealing that the
system is close to a mean motion resonance of about 9:2, in a stable
configuration over 1 Gyr. Stable orbits for low-mass planets are limited to
regions very close to the star or far from it. Our data exclude super-Earths
with Msin i \gtrsim 5 M_Earth within 0.4 AU and objects with Msin i \gtrsim 2
M_Earth with orbital periods of a few days. Finally we put constraints on the
habitable zone of the system, assuming the presence of an exomoon orbiting the
inner giant planet.


title:
On the radial profile of gas-phase Fe/{\alpha} ratio around distant
  galaxies

abstract:
  This paper presents a study of the chemical compositions in cool gas around a
sample of 27 intermediate-redshift galaxies. The sample comprises 13 massive
quiescent galaxies at z=0.40-0.73 probed by QSO sightlines at projected
distances d=3-400 kpc, and 14 star-forming galaxies at z=0.10-1.24 probed by
QSO sightlines at d=8-163 kpc. The main goal of this study is to examine the
radial profiles of the gas-phase Fe/{\alpha} ratio in galaxy halos based on the
observed Fe II to Mg II column density ratios. Because Mg+ and Fe+ share
similar ionization potentials, the relative ionization correction is small in
moderately ionized gas and the observed ionic abundance ratio N(Fe II)/N(Mg II)
places a lower limit to the underlying (Fe/Mg) elemental abundance ratio. For
quiescent galaxies, a median and dispersion of log <N(Fe II)/N(Mg II)>
=-0.06+/-0.15 is found at d<~60 kpc, which declines to log <N(Fe II)/N(Mg II)>
<-0.3 at d>~100 kpc. On the other hand, star-forming galaxies exhibit log <N(Fe
II)/N(Mg II)> =-0.25+/-0.21 at d<~60 kpc and log <N(Fe II)/N(Mg II)>
=-0.9+/-0.4 at larger distances. Including possible differential dust depletion
or ionization correction would only increase the inferred (Fe/Mg) ratio. The
observed N(FeII)/N(Mg II) implies super-solar Fe/{\alpha} ratios in the inner
halo of quiescent galaxies. An enhanced Fe abundance indicates a substantial
contribution by Type Ia supernovae in the chemical enrichment, which is at
least comparable to what is observed in the solar neighborhood or in
intracluster media but differs from young star-forming regions. In the outer
halos of quiescent galaxies and in halos around star-forming galaxies, however,
the observed N(Fe II)/N(Mg II) is consistent with an {\alpha}-element enhanced
enrichment pattern, suggesting a core-collapse supernovae dominated enrichment
history.


title:
Missile Attitude Control via a Hybrid LQG-LTR-LQI Control Scheme with
  Optimum Weight Selection

abstract:
  This paper proposes a new strategy for missile attitude control using a
hybridization of Linear Quadratic Gaussian (LQG), Loop Transfer Recovery (LTR),
and Linear Quadratic Integral (LQI) control techniques. The LQG control design
is carried out in two steps i.e. firstly applying Kalman filter for state
estimation in noisy environment and then using the estimated states for an
optimal state feedback control via Linear Quadratic Regulator (LQR). As further
steps of performance improvement of the missile attitude control system, the
LTR and LQI schemes are applied to increase the stability margins and guarantee
set-point tracking performance respectively, while also preserving the
optimality of the LQG. The weighting matrix (Q) and weighting factor (R) of LQG
and the LTR fictitious noise coefficient (q) are tuned using Nelder-Mead
Simplex optimization technique to make the closed-loop system act faster.
Simulations are given to illustrate the validity of the proposed technique.


title: Evolution of the Mass and Luminosity Functions of Globular Star Clusters

abstract:
  We reexamine the dynamical evolution of the mass and luminosity functions of
globular star clusters (GCMF and GCLF). Fall & Zhang (2001, hereafter FZ01)
showed that a power-law MF, as commonly seen among young cluster systems, would
evolve by dynamical processes over a Hubble time into a peaked MF with a shape
very similar to the observed GCMF in the Milky Way and other galaxies. To
simplify the calculations, the semi-analytical FZ01 model adopted the
"classical" theory of stellar escape from clusters, and neglected variations in
the $M/L$ ratios of clusters. Kruijssen & Portegies Zwart (2009, hereafter
KPZ09) modified the FZ01 model to include "retarded" and mass-dependent stellar
escape, the latter causing significant $M/L$ variations. KPZ09 asserted that
their model was compatible with observations whereas the FZ01 model was not. We
show here that this claim is not correct; the FZ01 and KPZ09 models fit the
observed Galactic GCLF equally well. We also show that there is no detectable
correlation between $M/L$ and $L$ for GCs in the Milky Way and Andromeda
galaxies, in contradiction with the KPZ09 model. Our comparisons of the FZ01
and KPZ09 models with observations can be explained most simply if stars escape
at rates approaching the classical limit for high-mass clusters, as expected on
theoretical grounds.


title:
Discontinuity of the phase transition for the planar random-cluster and
  Potts models with $q>4$

abstract:
  We prove that the $q$-state Potts model and the random-cluster model with
cluster weight $q>4$ undergo a discontinuous phase transition on the square
lattice. More precisely, we show
  - Existence of multiple infinite-volume measures for the critical Potts and
random-cluster models,
  - Ordering for the measures with monochromatic (resp. wired) boundary
conditions for the critical Potts model (resp. random-cluster model), and
  - Exponential decay of correlations for the measure with free boundary
conditions for both the critical Potts and random-cluster models.
  The proof is based on a rigorous computation of the Perron-Frobenius
eigenvalues of the diagonal blocks of the transfer matrix of the six-vertex
model, whose ratios are then related to the correlation length of the
random-cluster model.
  As a byproduct, we rigorously compute the correlation lengths of the critical
random-cluster and Potts models, and show that they behave as
$\exp(\pi^2/\sqrt{q-4})$ as $q$ tends to 4.


title: Identity-sensitive Word Embedding through Heterogeneous Networks

abstract:
  Most existing word embedding approaches do not distinguish the same words in
different contexts, therefore ignoring their contextual meanings. As a result,
the learned embeddings of these words are usually a mixture of multiple
meanings. In this paper, we acknowledge multiple identities of the same word in
different contexts and learn the \textbf{identity-sensitive} word embeddings.
Based on an identity-labeled text corpora, a heterogeneous network of words and
word identities is constructed to model different-levels of word
co-occurrences. The heterogeneous network is further embedded into a
low-dimensional space through a principled network embedding approach, through
which we are able to obtain the embeddings of words and the embeddings of word
identities. We study three different types of word identities including topics,
sentiments and categories. Experimental results on real-world data sets show
that the identity-sensitive word embeddings learned by our approach indeed
capture different meanings of words and outperforms competitive methods on
tasks including text classification and word similarity computation.


title:
The $Z$ decay width in the SMEFT: $y_t$ and $\lambda$ corrections at one
  loop

abstract:
  We calculate one loop $y_t$ and $\lambda$ dependent corrections to
$\bar{\Gamma}_Z,\bar{R}_f^0$ and the partial $Z$ widths due to dimension six
operators in the Standard Model Effective Field Theory (SMEFT), including
finite terms. We assume $\rm CP$ symmetry and a $\rm U(3)^5$ symmetry in the UV
matching onto the dimension six operators, dominantly broken by the Standard
Model Yukawa matrices. Corrections to these observables are predicted using the
input parameters $\{\hat{\alpha}_{ew}, \hat{M}_Z, \hat{G}_F, \hat{m}_t,
\hat{m}_h\}$ extracted with one loop corrections in the same limit. We show
that at one loop the number of SMEFT parameters contributing to the precise
LEPI pseudo-observables exceeds the number of measurements. As a result the
SMEFT parameters contributing to LEP data are formally unbounded when the size
of loop corrections are reached until other data is considered in a global
analysis. The size of these loop effects is generically a correction of order
$\sim\%$ to leading effects in the SMEFT, but we find multiple large numerical
coefficients in our calculation at this order. We use a $\rm \overline{MS}$
scheme, modified for the SMEFT, for renormalization. Some subtleties involving
novel evanescent scheme dependence present in this result are explained.


title: Kodaira-Saito vanishing via Higgs bundles in positive characteristic

abstract:
  The goal of this paper is to give a new proof of a special case of the
Kodaira-Saito vanishing theorem for a variation of Hodge structure on the
complement of a divisor with normal crossings. The proof does not use the
theory of mixed Hodge modules, but instead reduces it to a more general
vanishing theorem for semistable nilpotent Higgs bundles, which is then proved
by using some facts about Higgs bundles in positive characteristic.


title:
Control Strategy for Anaesthetic Drug Dosage with Interaction Among
  Human Physiological Organs Using Optimal Fractional Order PID Controller

abstract:
  In this paper, an efficient control strategy for physiological interaction
based anaesthetic drug infusion model is explored using the fractional order
(FO) proportional integral derivative (PID) controllers. The dynamic model is
composed of several human organs by considering the brain response to the
anaesthetic drug as output and the drug infusion rate as the control input.
Particle Swarm Optimisation (PSO) is employed to obtain the optimal set of
parameters for PID/FOPID controller structures. With the proposed FOPID control
scheme much less amount of drug-infusion system can be designed to attain a
specific anaesthetic target and also shows high robustness for +/-50%
parametric uncertainty in the patient's brain model.


title:
On Global attraction to solitary waves for Klein-Gordon equation with
  concentrated nonlinearity

abstract:
  The global attraction is proved for the nonlinear 3D Klein-Gordon equation
with a nonlinearity concentrated at one point. Our main result is the
convergence of each "finite energy solution" to the manifold of all solitary
waves as $t\to\pm\infty$. This global attraction is caused by the nonlinear
energy transfer from lower harmonics to the continuous spectrum and subsequent
dispersion radiation.
  We justify this mechanism by the following strategy based on inflation of
spectrum by the nonlinearity. We show that any omega-limit trajectory has the
time-spectrum in the spectral gap $[-m,m]$ and satisfies the original equation.
Then the application of the Titchmarsh Convolution Theorem reduces the spectrum
of each omega-limit trajectory to a single frequency $\omega\in[-m,m]$.


title:
The quantum vacuum in electromagnetic fields: From the Heisenberg-Euler
  effective action to vacuum birefringence

abstract:
  The focus of these lectures is on the quantum vacuum subjected to classical
electromagnetic fields. To this end we explicitly derive the renowned
Heisenberg-Euler effective action in constant electromagnetic fields in a
rather pedagogical and easy to conceive way. As an application, we use it to
study vacuum birefringence constituting one of the most promising optical
signatures of quantum vacuum nonlinearity.


title: All $(4,1)$: Sigma Models with $(4,q)$ Off-Shell Supersymmetry

abstract:
  Off-shell $(4,q)$ supermultiplets in 2-dimensions are constructed for
$q=1,2,4$. These are used to construct sigma models whose target spaces are
hyperk\"ahler with torsion. The off-shell supersymmetry implies the three
complex structures are simultaneously integrable and allows us to construct
actions using extended superspace and projective superspace, giving an explicit
construction of the target space geometries.


title:
The direct cooling tail method for X-ray burst analysis to constrain
  neutron star masses and radii

abstract:
  Determining neutron star (NS) radii and masses can help to understand the
properties of matter at supra-nuclear densities. Thermal emission during
thermonuclear X-ray bursts from NSs in low-mass X-ray binaries provides a
unique opportunity to study NS parameters, because of the high fluxes, large
luminosity variations and the related changes in the spectral properties. The
standard cooling tail method uses hot NS atmosphere models to convert the
observed spectral evolution during cooling stages of X-ray bursts to the
Eddington flux F_Edd and the stellar angular size \Omega. These are then
translated to the constraints on the NS mass M and radius R. Here we present
the improved, direct cooling tail method that generalises the standard
approach. First, we adjust the cooling tail method to account for the
bolometric correction to the flux. Then, we fit the observed dependence of the
blackbody normalization on flux with a theoretical model directly on the M-R
plane by interpolating theoretical dependences to a given gravity, hence
ensuring only weakly informative priors for M and R instead of F_Edd and
\Omega.
  The direct cooling method is demonstrated using a photospheric radius
expansion burst from SAX J1810.8--2609, which has happened when the system was
in the hard state. Comparing to the standard cooling tail method, the
confidence regions are shifted by 1 sigma towards larger radii, giving
R=11.5-13.0 km at M=1.3-1.8 M_sun for this NS.


title:
HST/COS Observations of Ionized Gas Accretion at the Disk-halo Interface
  of M33

abstract:
  We report the detection of accreting ionized gas at the disk-halo interface
of the nearby galaxy M33. We analyze HST/COS absorption-line spectra of seven
ultraviolet-bright stars evenly distributed across the disk of M33. We find Si
IV absorption components consistently redshifted relative to the bulk M33's ISM
absorption along all the sightlines. The Si IV detection indicates an enriched,
disk-wide, ionized gas inflow toward the disk. This inflow is most likely
multi-phase as the redshifted components can also be observed in ions with
lower ionization states (e.g., S II, P II, Fe II, Si II). Kinematic modeling of
the inflow is consistent with an accreting layer at the disk-halo interface of
M33, which has an accretion velocity of 110$^{+15}_{-20}$ km s$^{-1}$ at a
distance of 1.5$^{+1.0}_{-1.0}$ kiloparsec above the disk. The modeling
indicates a total mass of $\sim3.9\times10^7$ M$_{\odot}$ for the accreting
material at the disk-halo interface on the near side of the M33 disk , with an
accretion rate of $\sim2.9$ M$_{\odot}$ yr$^{-1}$. The high accretion rate and
the level of metal-enrichment suggest the inflow is likely to be the fall back
of M33 gas from a galactic fountain and/or the gas pulled loosed during a close
interaction between M31 and M33. Our study of M33 is the first to unambiguously
reveal the existence of a disk-wide, ionized gas inflow beyond the Milky Way,
providing a better understanding of gas accretion in the vicinity of a galaxy
disk.


title: A Bott periodicity proof for real graded $C^\ast$-algebras

abstract:
  We give a proof of Bott periodicity for real graded $C^\ast$-algebras in
terms of K- theory and E-theory. Guentner and Higson proved a similar result in
the complex graded case but we extend this to cover all graded
$C^\ast$-algebras. We obtain the 8-fold periodicity in E-theory by constructing
two maps that are inverse to each other.


title:
Existence of Millisecond-order Stable States in Time-Varying Phase
  Synchronization Measure in EEG Signals

abstract:
  In this paper, we have developed a new measure of understanding the temporal
evolution of phase synchronization for EEG signals using cross-electrode
information. From this measure it is found that there exists a small number of
well-defined phase-synchronized states, each of which is stable for few
milliseconds during the execution of a face perception task. We termed these
quasi-stable states as synchrostates. We used k-means clustering algorithms to
estimate the optimal number of synchrostates from 100 trials of EEG signals
over 128 channels. Our results show that these synchrostates exist consistently
in all the different trials. It is also found that from the onset of the
stimulus, switching between these synchrostates results in well-behaved
temporal sequence with repeatability which may be indicative of the dynamics of
the cognitive process underlying that task. Therefore these synchrostates and
their temporal switching sequences may be used as a new measure of the
stability of phase synchrony and information exchange between different regions
of a human brain.


title: On the asymptotic formula in Waring's problem with shifts

abstract:
  We show that for integers $k\geq 4$ and $s\geq k^2+(3k-1)/4$, we have an
asymptotic formula for the number of solutions, in positive integers $x_i$, to
the inequality
$\left|(x_1-\theta_1)^k+\dotsc+(x_s-\theta_s)^k-\tau\right|<\eta$, where
$\theta_i\in(0,1)$ with $\theta_1$ irrational, $\eta\in(0,1]$, and $\tau>0$ is
sufficiently large. We use Freeman's variant of the Davenport--Heilbronn
method, along with a new estimate on the Hardy--Littlewood minor arcs, to
obtain this improvement on the original result of Chow.


title: An Affine-Invariant Bayesian Cluster Process

abstract:
  In order to identify clusters of objects with features transformed by unknown
affine transformations, we develop a Bayesian cluster process which is
invariant with respect to certain linear transformations of the feature space
and able to cluster data without knowing the number of clusters in advance.
Specifically, our proposed method can identify clusters invariant to orthogonal
transformations under model I, invariant to scaling-coordinate orthogonal
transformations under model II, or invariant to arbitrary non-singular linear
transformations under model III. The proposed split-merge algorithm leads to an
irreducible and aperiodic Markov chain, which is also efficient at identifying
clusters reasonably well for various applications. We illustrate the
applications of our approach to both synthetic and real data such as leukemia
gene expression data for model I; wine data and two half-moons benchmark data
for model II; three-dimensional Denmark road geographic coordinate system data
and an arbitrary non-singular transformed two half-moons data for model III.
These examples show that the proposed method could be widely applied in many
fields, especially for finding the number of clusters and identifying clusters
of samples of interest in aerial photography and genomic data.


title:
Using Brain Connectivity Measure of EEG Synchrostates for Discriminating
  Typical and Autism Spectrum Disorder

abstract:
  In this paper we utilized the concept of stable phase synchronization
topography - synchrostates - over the scalp derived from EEG recording for
formulating brain connectivity network in Autism Spectrum Disorder (ASD) and
typically-growing children. A synchronization index is adapted for forming the
edges of the connectivity graph capturing the stability of each of the
synchrostates. Such network is formed for 11 ASD and 12 control group children.
Comparative analyses of these networks using graph theoretic measures show that
children with autism have a different modularity of such networks from typical
children. This result could pave the way to a new modality for possible
identification of ASD from non-invasively recorded EEG data.


title:
A Computationally Efficient Approach for Calculating Galaxy Two-Point
  Correlations

abstract:
  We developed a modification to the calculation of the two-point correlation
function commonly used in the analysis of large scale structure in cosmology.
An estimator of the two-point correlation function is constructed by
contrasting the observed distribution of galaxies with that of a uniformly
populated random catalog. Using the assumption that the distribution of random
galaxies in redshift is independent of angular position allows us to replace
pairwise combinatorics with fast integration over probability maps. The new
method significantly reduces the computation time while simultaneously
increasing the precision of the calculation. It also allows to introduce
cosmological parameters only at the last and least computationally expensive
stage, which is helpful when exploring various choices for these parameters.


title:
Exploring the Uncharted Export: an Analysis of Tourism-Related Foreign
  Expenditure with International Spend Data

abstract:
  Tourism is one of the most important economic activities in the world: for
many countries it represents the single largest product in their export basket.
However, it is a product difficult to chart: "exporters" of tourism do not ship
it abroad, but they welcome importers inside the country. Current research uses
social accounting matrices and general equilibrium models, but the standard
industry classifications they use make it hard to identify which domestic
industries cater to foreign visitors. In this paper, we make use of open source
data and of anonymized and aggregated transaction data giving us insights about
the spend behavior of foreigners inside two countries, Colombia and the
Netherlands, to inform our research. With this data, we are able to describe
what constitutes the tourism sector, and to map the most attractive
destinations for visitors. In particular, we find that countries might observe
different geographical tourists' patterns -- concentration versus
decentralization --; we show the importance of distance, a country's reported
wealth and cultural affinity in informing tourism; and we show the potential of
combining open source data and anonymized and aggregated transaction data on
foreign spend patterns in gaining insight as to the evolution of tourism from
one year to another.


title:
Exploration for Multi-task Reinforcement Learning with Deep Generative
  Models

abstract:
  Exploration in multi-task reinforcement learning is critical in training
agents to deduce the underlying MDP. Many of the existing exploration
frameworks such as $E^3$, $R_{max}$, Thompson sampling assume a single
stationary MDP and are not suitable for system identification in the multi-task
setting. We present a novel method to facilitate exploration in multi-task
reinforcement learning using deep generative models. We supplement our method
with a low dimensional energy model to learn the underlying MDP distribution
and provide a resilient and adaptive exploration signal to the agent. We
evaluate our method on a new set of environments and provide intuitive
interpretation of our results.


title:
Cluster superconductivity in the magnetoelectric Pb(Fe1/2Sb1/2)O3
  ceramics

abstract:
  We report the observation of cluster (local) superconductivity in the
magnetoelectric Pb(Fe1/2Sb1/2)O3 ceramics prepared at a hydrostatic pressure of
6 GPa and temperatures 1200-1800 K to stabilize the perovskite phase. The
superconductivity is manifested by an abrupt drop of the magnetic
susceptibility at the critical temperature TC 7 K. Both the magnitude of this
drop and TC decrease with magnetic field increase. Similarly, the low-field
paramagnetic absorption measured by EPR spectrometer drops significantly below
TC as well. The observed effects and their critical magnetic field dependence
are interpreted as manifestation of the superconductivity and Meissner effect
in metallic Pb nanoclusters existing in the ceramics. Their volume fraction and
average size were estimated as 0.1-0.2% and 140-150 nm, respectively. The
superconductivity related effects disappear after oxidizing annealing of the
ceramics.


title:
Mode Characterization for Planar and Corrugated Multilayer Structures
  via Scattering Matrix Analysis

abstract:
  The construction of the unconditionally stable planar rank 2 scattering
matrix for stratified systems is detailed from Fresnel equations. Several
matrix decompositions and numerical calculations performed on the planar S
matrix allow for the expedient characterization of purely absorbing, brewster,
surface plasmon, and wave-guide modes. A figure of merit is presented from the
decompositions of the scattering matrix constructed from the Chandezon method
for corrugated surfaces. This figure of merit represents the hyper-area of the
scattering matrix transform and allows for rapid distinguishability between
lossy absorption phenomena, and surface plasmons. Some extension of this
technique is possible for surface plasmon polaritons in the infrared region.


title:
Autism Spectrum Disorder Classification using Graph Kernels on
  Multidimensional Time Series

abstract:
  We present an approach to model time series data from resting state fMRI for
autism spectrum disorder (ASD) severity classification. We propose to adopt
kernel machines and employ graph kernels that define a kernel dot product
between two graphs. This enables us to take advantage of spatio-temporal
information to capture the dynamics of the brain network, as opposed to
aggregating them in the spatial or temporal dimension. In addition to the
conventional similarity graphs, we explore the use of L1 graph using sparse
coding, and the persistent homology of time delay embeddings, in the proposed
pipeline for ASD classification. In our experiments on two datasets from the
ABIDE collection, we demonstrate a consistent and significant advantage in
using graph kernels over traditional linear or non linear kernels for a variety
of time series features.


title: On k-sparse numerical semigroups

abstract:
  Given a positive integer k, we investigate the class of numerical semigroups
verifying the property that every two subsequent non gaps, smaller than the
conductor, are spaced by at least k. These semigroups will be called k-sparse
and generalize the concept of sparse numerical semigroups.


title:
Magnetoelectric effect in antiferromagnetic multiferroic
  Pb(Fe1/2Nb1/2)O3 and its solid solutions with PbTiO3

abstract:
  Antiferromagnets (AFMs) are presently considered as promising materials for
applications in spintronics and random access memories due to the robustness of
information stored in AFM state against perturbing magnetic fields (P. Wadley
et al., Science 351, 587 (2016)). In this respect, AFM multiferroics maybe
attractive alternatives for conventional AFMs as the coupling of magnetism with
ferroelectricity (magnetoelectric effect) offers an elegant possibility of
electric field control and switching of AFM domains. Here we report the results
of comprehensive experimental and theoretical investigations of the quadratic
magnetoelectric (ME) effect in single crystals and high-resistive ceramics of
Pb(Fe1/2Nb1/2)O3 (PFN) and (1- x)Pb(Fe1/2Nb1/2)O3xPbTiO3 (PFNxPT). We are
interested primarily in the temperature range of multiferroic phase, T < 150 K,
where the ME coupling coefficient is extremely large (as compared to well-known
multiferroic BiFeO3) and shows sign reversal at
paramagnetic-to-antiferromagnetic phase transition. Moreover, we observe strong
ME response nonlinearity in the AFM phase in the magnetic fields of only few
kOe. To describe the temperature and magnetic field dependencies of the above
unusual features of ME effect in PFN and PFN-xPT, we use simple
phenomenological Landau approach which explains experimental data surprisingly
well. Our ME measurements demonstrate that the electric field of only 20-25
kV/cm is able to switch the AFM domains and align them with ferroelectric ones
even in PFN ceramic samples.


title: Context-aware Natural Language Generation with Recurrent Neural Networks

abstract:
  This paper studied generating natural languages at particular contexts or
situations. We proposed two novel approaches which encode the contexts into a
continuous semantic representation and then decode the semantic representation
into text sequences with recurrent neural networks. During decoding, the
context information are attended through a gating mechanism, addressing the
problem of long-range dependency caused by lengthy sequences. We evaluate the
effectiveness of the proposed approaches on user review data, in which rich
contexts are available and two informative contexts, sentiments and products,
are selected for evaluation. Experiments show that the fake reviews generated
by our approaches are very natural. Results of fake review detection with human
judges show that more than 50\% of the fake reviews are misclassified as the
real reviews, and more than 90\% are misclassified by existing state-of-the-art
fake review detection algorithm.


title:
Rotations of small, inertialess triaxial ellipsoids in isotropic
  turbulence

abstract:
  The statistics of rotational motion of small, inertialess triaxial ellipsoids
are computed along Lagrangian trajectories extracted from direct numerical
simulations of homogeneous isotropic turbulence. The particle angular velocity
and its components along the three principal axes of the particle are
considered, expanding on the results presented by \citet{ChevillardMeneveau13}.
The variance of the particle angular velocity, referred to as the particle
enstrophy, is found to increase for particles with elongated shapes. This trend
is explained by considering the contributions of vorticity and strain-rate to
particle rotation. It is found that the majority of particle enstrophy is due
to fluid vorticity. Strain-rate-induced rotations, which are sensitive to
shape, are mostly cancelled by strain-vorticity interactions. The remainder of
the strain-rate-induced rotations are responsible for weak variations in
particle enstrophy. For particles of all shapes, the majority of the enstrophy
is in rotations about the longest axis, which is due to alignment between the
longest axis and fluid vorticity. The integral timescale for particle angular
velocities about each axis reveals that rotations are most persistent about the
longest axis, but that a full revolution is rare.


title: A nonlocal concave-convex problem with nonlocal mixed boundary data

abstract:
  The aim of this paper is to study a nonlocal problem with a mixed
Dirichlet-Neumann exterior condition. We prove existence, nonexistence and
multiplicity of positive energy solutions and describe the interaction between
the concave-convex nonlinearity and the Dirichlet-Neumann data.


title: Pulsed entanglement of two optomechanical oscillators

abstract:
  A strategy for generating entanglement in two separated optomechanical
oscillators is analysed, using entangled radiation produced from downconversion
and stored in an initiating cavity. We show that the use of pulsed entanglement
with optimally shaped temporal modes can efficiently transfer quantum
entanglement into a mechanical mode, then remove it after a fixed waiting time
for measurement. This protocol could provide new avenues to test for bounds on
decoherence in massive systems that are spatially separated, as originally
suggested by Wendell Furry [1] not long after the discussion by
Einstein-Podolsky-Rosen (EPR) and Schrodinger of entanglement.


title:
C-RNN-GAN: Continuous recurrent neural networks with adversarial
  training

abstract:
  Generative adversarial networks have been proposed as a way of efficiently
training deep generative neural networks. We propose a generative adversarial
model that works on continuous sequential data, and apply it by training it on
a collection of classical music. We conclude that it generates music that
sounds better and better as the model is trained, report statistics on
generated music, and let the reader judge the quality by downloading the
generated songs.