title:
Using Non-invertible Data Transformations to Build Adversarial-Robust
  Neural Networks

abstract:
  Deep neural networks have proven to be quite effective in a wide variety of
machine learning tasks, ranging from improved speech recognition systems to
advancing the development of autonomous vehicles. However, despite their
superior performance in many applications, these models have been recently
shown to be susceptible to a particular type of attack possible through the
generation of particular synthetic examples referred to as adversarial samples.
These samples are constructed by manipulating real examples from the training
data distribution in order to "fool" the original neural model, resulting in
misclassification (with high confidence) of previously correctly classified
samples. Addressing this weakness is of utmost importance if deep neural
architectures are to be applied to critical applications, such as those in the
domain of cybersecurity. In this paper, we present an analysis of this
fundamental flaw lurking in all neural architectures to uncover limitations of
previously proposed defense mechanisms. More importantly, we present a unifying
framework for protecting deep neural models using a non-invertible data
transformation--developing two adversary-resilient architectures utilizing both
linear and nonlinear dimensionality reduction. Empirical results indicate that
our framework provides better robustness compared to state-of-art solutions
while having negligible degradation in accuracy.


title:
Sequence-based Sleep Stage Classification using Conditional Neural
  Fields

abstract:
  Sleep signals from a polysomnographic database are sequences in nature.
Commonly employed analysis and classification methods, however, ignored this
fact and treated the sleep signals as non-sequence data. Treating the sleep
signals as sequences, this paper compared two powerful unsupervised feature
extractors and three sequence-based classifiers regarding accuracy and
computational (training and testing) time after 10-folds cross-validation. The
compared feature extractors are Deep Belief Networks (DBN) and Fuzzy C-Means
(FCM) clustering. Whereas the compared sequence-based classifiers are Hidden
Markov Models (HMM), Conditional Random Fields (CRF) and its variants, i.e.,
Hidden-state CRF (HCRF) and Latent-Dynamic CRF (LDCRF); and Conditional Neural
Fields (CNF) and its variant (LDCNF). In this study, we use two datasets. The
first dataset is an open (public) polysomnographic dataset downloadable from
the Internet, while the second dataset is our polysomnographic dataset (also
available for download). For the first dataset, the combination of FCM and CNF
gives the highest accuracy (96.75\%) with relatively short training time (0.33
hours). For the second dataset, the combination of DBN and CRF gives the
accuracy of 99.96\% but with 1.02 hours training time, whereas the combination
of DBN and CNF gives slightly less accuracy (99.69\%) but also less computation
time (0.89 hours).


title:
New Solar Irradiance Measurements from the Miniature X-Ray Solar
  Spectrometer CubeSat

abstract:
  The goal of the Miniature X-ray Solar Spectrometer (MinXSS) CubeSat is to
explore the energy distribution of soft X-ray (SXR) emissions from the
quiescent Sun, active regions, and during solar flares, and to model the impact
on Earth's ionosphere and thermosphere. The energy emitted in the SXR range
(0.1 --10 keV) can vary by more than a factor of 100, yet we have limited
spectral measurements in the SXRs to accurately quantify the spectral
dependence of this variability. The MinXSS primary science instrument is an
Amptek, Inc. X123 X-ray spectrometer that has an energy range of 0.5--30 keV
with a nominal 0.15 keV energy resolution. Two flight models have been built.
The first, MinXSS-1, has been making science observations since 2016 June 9,
and has observed numerous flares, including more than 40 C-class and 7 M-class
flares. These SXR spectral measurements have advantages over broadband SXR
observations, such as providing the capability to derive multiple-temperature
components and elemental abundances of coronal plasma, improved irradiance
accuracy, and higher resolution spectral irradiance as input to planetary
ionosphere simulations. MinXSS spectra obtained during the M5.0 flare on 2016
July 23 highlight these advantages, and indicate how the elemental abundance
appears to change from primarily coronal to more photospheric during the flare.
MinXSS-1 observations are compared to the Geostationary Operational
Environmental Satellite (GOES) X-Ray Sensor (XRS) measurements of SXR
irradiance and estimated corona temperature. Additionally, a suggested
improvement to the calibration of the GOES XRS data is presented.

categories: astro-ph.SR astro-ph.HE astro-ph.IM physics.space-ph


title:
Trading against disorderly liquidation of a large position under
  asymmetric information and market impact

abstract:
  We consider trading against a hedge fund or large trader that must liquidate
a large position in a risky asset if the market price of the asset crosses a
certain threshold. Liquidation occurs in a disorderly manner and negatively
impacts the market price of the asset. We consider the perspective of small
investors whose trades do not induce market impact and who possess different
levels of information about the liquidation trigger mechanism and the market
impact. We classify these market participants into three types: fully informed,
partially informed and uninformed investors. We consider the portfolio
optimization problems and compare the optimal trading and wealth processes for
the three classes of investors theoretically and by numerical illustrations.


title: Absence of percolation for Poisson outdegree-one graphs

abstract:
  A Poisson outdegree-one graph is an oriented graph based on a Poisson point
process such that each vertex has only one outgoing edge. The paper focuses on
the absence of percolation for such graphs. Our main result is based on two
assumptions. The Shield assumption ensures that the graph is locally determined
with possible random horizons. The Loop assumption ensures that any forward
branch of the graph merges on a loop provided that the Poisson point process is
augmented with a finite collection of well-chosen points. Several models
satisfy these general assumptions and inherit in consequence the absence of
percolation. In particular, we solve a conjecture by Daley et al. on the
absence of percolation for the line-segment model. In this planar model, a
segment is growing from any point of the Poisson process and stops its growth
whenever it hits another segment. The random directions are picked
independently and uniformly on the unit sphere. Another model of geometric
navigation is presented and also fulfills the Shield and Loop assumptions.


title:
Localization Properties of the XY Spin Chain. A review of mathematical
  results with an eye toward Many-Body Localization

abstract:
  We review several aspects of Many-Body Localization-like properties exhibited
by the disordered XY chains: localization properties of the energy eigenstates
and thermal states, propagation bounds of Lieb-Robinson type, decay of
correlation functions, absence of particle transport, bounds on the bipartite
entanglement, and bounded entanglement growth under the dynamics. We also prove
new results on the absence of energy transport and Fock space localization. All
these properties are made accessible to mathematical analysis due to the exact
mapping of the XY chain to a system of quasi-free fermions given by the
Jordan-Wigner transformation. Motivated by these results we discuss conjectured
properties of more general disordered quantum spin and other systems as
possible directions for future mathematical research.


title: Schwinger-Keldysh formalism I: BRST symmetries and superspace

abstract:
  We review the Schwinger-Keldysh, or in-in, formalism for studying quantum
dynamics of systems out-of-equilibrium. The main motivation is to rephrase well
known facts in the subject in a mathematically elegant setting, by exhibiting a
set of BRST symmetries inherent in the construction. We show how these
fundamental symmetries can be made manifest by working in a superspace
formalism. We argue that this rephrasing is extremely efficacious in
understanding low energy dynamics following the usual renormalization group
approach, for the BRST symmetries are robust under integrating out degrees of
freedom. In addition we discuss potential generalizations of the formalism that
allow us to compute out-of-time-order correlation functions that have been the
focus of recent attention in the context of chaos and scrambling. We also
outline a set of problems ranging from stochastic dynamics, hydrodynamics,
dynamics of entanglement in QFTs, and the physics of black holes and cosmology,
where we believe this framework could play a crucial role in demystifying
various confusions. Our companion paper arXiv:1610.01941 describes in greater
detail the mathematical framework embodying the topological symmetries we
uncover here.

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


title: Schwinger-Keldysh formalism II: Thermal equivariant cohomology

abstract:
  Causally ordered correlation functions of local operators in near-thermal
quantum systems computed using the Schwinger-Keldysh formalism obey a set of
Ward identities. These can be understood rather simply as the consequence of a
topological (BRST) algebra, called the universal Schwinger-Keldysh
superalgebra, as explained in our companion paper arXiv:1610.01940. In the
present paper we provide a mathematical discussion of this topological algebra.
In particular, we argue that the structures can be understood in the language
of extended equivariant cohomology. To keep the discussion self-contained, we
provide a basic review of the algebraic construction of equivariant cohomology
and explain how it can be understood in familiar terms as a superspace gauge
algebra. We demonstrate how the Schwinger-Keldysh construction can be
succinctly encoded in terms a thermal equivariant cohomology algebra which
naturally acts on the operator (super)-algebra of the quantum system. The main
rationale behind this exploration is to extract symmetry statements which are
robust under renormalization group flow and can hence be used to understand
low-energy effective field theory of near-thermal physics. To illustrate the
general principles, we focus on Langevin dynamics of a Brownian particle,
rephrasing some known results in terms of thermal equivariant cohomology. As
described elsewhere, the general framework enables construction of effective
actions for dissipative hydrodynamics and could potentially illumine our
understanding of black holes.


title:
Calculation of Stark resonance parameters for valence orbitals of the
  water molecule

abstract:
  An exterior complex scaling technique is applied to compute Stark resonance
parameters for two molecular orbitals ($1b_{1}$ and $1b_{2}$) represented in
the field-free limit in a single-center expansion. For electric DC field
configurations that guarantee azimuthal symmetry of the solution the
calculation is carried out by solving a two-dimensional partial differential
equation in spherical polar coordinates using a finite-element method. The
resonance positions and widths as a function of electric field strengths are
shown for field strengths starting in the tunnelling ionization regime, and
extending well into the over-barrier ionization region.


title: A Lower Bound For Biases Amongst Products Of Two Primes

abstract:
  We establish a conjectured result of Dummit, Granville and Kisilevsky for the
maximum bias in P2 races, which compare the number of P2's $\leq x$ whose prime
factors, evaluated at a given quadratic character, take specifc values.


title: PetroSurf3D - A Dataset for high-resolution 3D Surface Segmentation

abstract:
  The development of powerful 3D scanning hardware and reconstruction
algorithms has strongly promoted the generation of 3D surface reconstructions
in different domains. An area of special interest for such 3D reconstructions
is the cultural heritage domain, where surface reconstructions are generated to
digitally preserve historical artifacts. While reconstruction quality nowadays
is sufficient in many cases, the robust analysis (e.g. segmentation, matching,
and classification) of reconstructed 3D data is still an open topic. In this
paper, we target the automatic and interactive segmentation of high-resolution
3D surface reconstructions from the archaeological domain. To foster research
in this field, we introduce a fully annotated and publicly available
large-scale 3D surface dataset including high-resolution meshes, depth maps and
point clouds as a novel benchmark dataset to the community. We provide baseline
results for our existing random forest-based approach and for the first time
investigate segmentation with convolutional neural networks (CNNs) on the data.
Results show that both approaches have complementary strengths and weaknesses
and that the provided dataset represents a challenge for future research.


title: Connecting Generative Adversarial Networks and Actor-Critic Methods

abstract:
  Both generative adversarial networks (GAN) in unsupervised learning and
actor-critic methods in reinforcement learning (RL) have gained a reputation
for being difficult to optimize. Practitioners in both fields have amassed a
large number of strategies to mitigate these instabilities and improve
training. Here we show that GANs can be viewed as actor-critic methods in an
environment where the actor cannot affect the reward. We review the strategies
for stabilizing training for each class of models, both those that generalize
between the two and those that are particular to that model. We also review a
number of extensions to GANs and RL algorithms with even more complicated
information flow. We hope that by highlighting this formal connection we will
encourage both GAN and RL communities to develop general, scalable, and stable
algorithms for multilevel optimization with deep networks, and to draw
inspiration across communities.


title: Efficient Valuation of SCR via a Neural Network Approach

abstract:
  As part of the new regulatory framework of Solvency II, introduced by the
European Union, insurance companies are required to monitor their solvency by
computing a key risk metric called the Solvency Capital Requirement (SCR). The
official description of the SCR is not rigorous and has lead researchers to
develop their own mathematical frameworks for calculation of the SCR. These
frameworks are complex and are difficult to implement. Recently, Bauer et al.
suggested a nested Monte Carlo (MC) simulation framework to calculate the SCR.
But the proposed MC framework is computationally expensive even for a simple
insurance product. In this paper, we propose incorporating a neural network
approach into the nested simulation framework to significantly reduce the
computational complexity in the calculation. We study the performance of our
neural network approach in estimating the SCR for a large portfolio of an
important class of insurance products called Variable Annuities (VAs). Our
experiments show that the proposed neural network approach is both efficient
and accurate.


title:
Commissioning of the new multi-layer integration prototype of the CALICE
  tile hadron calorimeter

abstract:
  The basic prototype of a tile hadron calorimeter (HCAL) for the International
Linear Collider (ILC) has been realised and extensively tested. A major aspect
of the proposed concept is the improvement of the jet energy resolution by
measuring details of the shower development and combining them with the data of
the tracking system (particle flow). The prototype utilises scintillating tiles
that are read out by novel Silicon Photomultipliers (SiPMs) and takes into
account all design aspects that are demanded by the intended operation at the
ILC. Currently, a new 12 layer prototype with about 3400 detector channels is
under development. Alternative architectures for the scintillating tiles with
and without wavelength-shifting fibres and tiles with individual wrapping with
reflector foil is tested as well as different types of SiPMs. The new prototype
was used for the first time at the CERN Proton Synchrotron test facility in
fall 2014. Additionally, detector modules for the CALICE scintillator-based
Electromagnetic Calorimeter (Sc-ECAL), that follow the proposed HCAL
electronics architecture, were part of this new prototype. A new multi-layer
Data Acquisition System (DAQ) was used for the detector configuration and
operation.


title: Quantum Anomalous Hall State in Ferromagnetic SrRuO$_3$ (111) Bilayers

abstract:
  SrRuO$_3$ heterostructures grown in the (111) direction are a rare example of
thin film ferromagnets. By means of density functional theory plus dynamical
mean field theory we show that the half-metallic ferromagnetic state with an
ordered magnetic moment of 2$\mu_{B}$/Ru survives the ultimate dimensional
confinement down to a bilayer, even at elevated temperatures of 500$\,$K. In
the minority channel, the spin-orbit coupling opens a gap at the linear band
crossing corresponding to $\frac34$ filling of the $t_{2g}$ shell. We
demonstrate that the respective state is Haldane's quantum anomalous Hall state
with Chern number $C$=1, without an external magnetic field or magnetic
impurities.


title:
Understanding the role of transport velocity in biomotor-powered
  microtubule spool assembly

abstract:
  We examined the sensitivity of microtubule spools to transport velocity.
Perhaps surprisingly, we determined that the steady-state number and size of
spools remained constant over a seven-fold range of velocities. Our data on the
kinetics of spool assembly further suggest that the main mechanisms underlying
spool growth vary during assembly.


title: Global viscosity solutions of generalized Kahler-Ricci flow

abstract:
  We apply ideas from viscosity theory to establish the existence of a unique
global weak solution to the generalized Kahler-Ricci flow in the setting of
commuting complex structures. Our results are restricted to the case of a
smooth manifold with smooth background data. We discuss the possibility of
extending these results to more singular settings, pointing out a key error in
the existing literature on viscosity solutions to complex Monge-Ampere
equations/Kahler-Ricci flow.


title: The time evolution of HH~2 from four epochs of HST images

abstract:
  We have analyzed four epochs of H$\alpha$ and [S~II] HST images of the HH~1/2
outflow (covering a time interval from 1994 to 2014) to determine proper
motions and emission line fluxes of the knots of HH~2. We find that our new
proper motions agree surprisingly well with the motions measured by Herbig \&
Jones (1981), although there is partial evidence for a slight deceleration of
the motion of the HH~2 knots from 1945 to 2014. We also measure the
time-variability of the H$\alpha$ intensities and the [S~II]/H$\alpha$ line
ratios, and find that knots H and A have the largest intensity variabilities
(in $1994\to 2014$). Knot H (which now dominates the HH~2 emission) has
strengthened substantially, while keeping an approximately constant
[S~II]/H$\alpha$ ratio. Knot A has dramatically faded, and at the same time has
had a substantial increase in its [S~II]/H$\alpha$ ratio. Possible
interpretations of these results are discussed.


title:
A Machine Learning Approach to Optimal Tikhonov Regularisation I: Affine
  Manifolds

abstract:
  Despite a variety of available techniques the issue of the proper
regularization parameter choice for inverse problems still remains one of the
biggest challenges. The main difficulty lies in constructing a rule, allowing
to compute the parameter from given noisy data without relying either on a
priori knowledge of the solution or on the noise level. In this paper we
propose a novel method based on supervised machine learning to approximate the
high-dimensional function, mapping noisy data into a good approximation to the
optimal Tikhonov regularization parameter. Our assumptions are that solutions
of the inverse problem are statistically distributed in a concentrated manner
on (lower-dimensional) linear subspaces and the noise is sub-gaussian. One of
the surprising facts is that the number of previously observed examples for the
supervised learning of the optimal parameter mapping scales at most linearly
with the dimension of the solution subspace. We also provide explicit error
bounds on the accuracy of the approximated parameter and the corresponding
regularization solution. Even though the results are more of theoretical
nature, we present a recipe for the practical implementation of the approach
and provide numerical experiments confirming the theoretical results. We also
outline interesting directions for future research with some preliminary
results, confirming their feasibility.


title: The Future Internet of Things and Security of its Control Systems

abstract:
  We consider the future cyber security of industrial control systems. As best
as we can see, much of this future unfolds in the context of the Internet of
Things (IoT). In fact, we envision that all industrial and infrastructure
environments, and cyber-physical systems in general, will take the form
reminiscent of what today is referred to as the IoT. IoT is envisioned as
multitude of heterogeneous devices densely interconnected and communicating
with the objective of accomplishing a diverse range of objectives, often
collaboratively. One can argue that in the relatively near future, the IoT
construct will subsume industrial plants, infrastructures, housing and other
systems that today are controlled by ICS and SCADA systems. In the IoT
environments, cybersecurity will derive largely from system agility,
moving-target defenses, cybermaneuvering, and other autonomous or
semi-autonomous behaviors. Cyber security of IoT may also benefit from new
design methods for mixed-trusted systems; and from big data analytics --
predictive and autonomous.


title: Derivatives characterization of Bergman-Orlicz spaces and applications

abstract:
  It is well known that a function is in a Bergman space of the unit ball if
and only if it satisfies some Hardy-type inequalities. We extend this fact to
Bergman-Orlicz spaces. As applications, we obtain Gustavsson-Peetre
interpolation of two Bergman-Orlicz spaces and we completely characterize
symbols of bounded or compact Ces\`aro-type operators on Bergman-Orlicz spaces,
extending known results for classical weighted Bergman spaces.


title: MoveSteg: A Method of Network Steganography Detection

abstract:
  This article presents a new method for detecting a source point of time based
network steganography - MoveSteg. A steganography carrier could be an example
of multimedia stream made with packets. These packets are then delayed
intentionally to send hidden information using time based steganography
methods. The presented analysis describes a method that allows finding the
source of steganography stream in network that is under our management.


title:
Static configurations and evolution of higher dimensional brane-dilaton
  black hole system

abstract:
  Static configurations and a dynamical evolution of the system composed of a
higher-dimensional spherically symmetric dilaton black hole and the
Dirac-Goto-Nambu brane were investigated. The studies were conducted for three
values of the dilaton coupling constant, describing the uncoupled case, the
low-energy limit of the string theory and dimensionally reduced Klein-Kaluza
theories. When the black hole is nonextremal, two types of static
configurations are observed, a brane which intersects the black hole horizon
and a brane not having any common points with the accompanying black hole. As
the number of spacetime dimensions increases, the brane bend in the vicinity of
the black hole disappears closer to its horizon. Dynamical evolution of the
system results in an expulsion of the black hole from the brane. It proceeds
faster for bigger values of the bulk spacetime dimension and thicker branes.
The value of the dilatonic coupling constant does not influence neither the
static configurations nor the dynamical behavior of the examined nonextremal
system. In the extremal dilaton black hole case one obtains expulsion of the
brane which is independent on the spacetime dimensionality and the value of the
coupling constant. Dynamical studies of the configurations in the extremal case
reveal that the course of evolution of the system is similar to the nonextremal
one, except for a slightly earlier expulsion of the black hole from the brane.


title: Polymeric quantum mechanics and the zeros of the Riemann zeta function

abstract:
  We analize the Berry-Keating model and the Sierra and Rodr\'iguez-Laguna
Hamiltonian within the polymeric quantization formalism. By using the polymer
representation, we obtain for both models, the associated polymeric quantum
Hamiltonians and the corresponding stationary wave functions. The
self-adjointness condition provide a proper domain for the Hamiltonian operator
and the energy spectrum, which turned out to be dependent on an introduced
scale parameter. By performing a counting of semiclassical states, we prove
that the polymer representation reproduces the smooth part of the Riemann-von
Mangoldt formula, and introduces a correction depending on the energy and the
scale parameter, which resembles the fluctuation behavior of the Riemann zeros.


title: Uniform sparse domination of singular integrals via dyadic shifts

abstract:
  Using the Calder\'on-Zygmund decomposition, we give a novel and simple proof
that $L^2$ bounded dyadic shifts admit a domination by positive sparse forms
with linear growth in the complexity of the shift. Our estimate, coupled with
Hyt\"onen's dyadic representation theorem, upgrades to a positive sparse
domination of the class $\mathcal U$ of singular integrals satisfying the
assumptions of the classical $T(1)$-theorem of David and Journ\'e, with
logarithmic-Dini type smoothness of the integral kernel. Furthermore, our proof
extends rather easily to the $\mathbb R^n$-valued case, yielding as a corollary
the operator norm bound on the matrix weighted space $L^2(W; \mathbb R^n),$
  \[
  \left\|T\otimes \mathrm{Id}_{\mathbb R^n}\right\|_{L^2(W; \mathbb
R^n)\rightarrow L^2(W; \mathbb R^n)} \lesssim [W]_{A_2}^{\frac32}
  \] uniformly over $T\in \mathcal U$, which is the currently best known
dependence.


title: Efficient L1-Norm Principal-Component Analysis via Bit Flipping

abstract:
  It was shown recently that the $K$ L1-norm principal components (L1-PCs) of a
real-valued data matrix $\mathbf X \in \mathbb R^{D \times N}$ ($N$ data
samples of $D$ dimensions) can be exactly calculated with cost
$\mathcal{O}(2^{NK})$ or, when advantageous, $\mathcal{O}(N^{dK - K + 1})$
where $d=\mathrm{rank}(\mathbf X)$, $K<d$ [1],[2]. In applications where
$\mathbf X$ is large (e.g., "big" data of large $N$ and/or "heavy" data of
large $d$), these costs are prohibitive. In this work, we present a novel
suboptimal algorithm for the calculation of the $K < d$ L1-PCs of $\mathbf X$
of cost $\mathcal O(ND \mathrm{min} \{ N,D\} + N^2(K^4 + dK^2) + dNK^3)$, which
is comparable to that of standard (L2-norm) PC analysis. Our theoretical and
experimental studies show that the proposed algorithm calculates the exact
optimal L1-PCs with high frequency and achieves higher value in the L1-PC
optimization metric than any known alternative algorithm of comparable
computational cost. The superiority of the calculated L1-PCs over standard
L2-PCs (singular vectors) in characterizing potentially faulty
data/measurements is demonstrated with experiments on data dimensionality
reduction and disease diagnosis from genomic data.


title:
Nonlinear interplay of Alfven instabilities and energetic particles in
  tokamaks

abstract:
  The confinement of energetic particles (EP) is crucial for an efficient
heating of tokamak plasmas. Plasma instabilities such as Alfven Eigenmodes (AE)
can redistribute the EP population making the plasma heating less effective,
and leading to additional loads on the walls. The nonlinear dynamics of
toroidicity induced AE (TAE) is investigated by means of the global gyrokinetic
particle-in-cell code ORB5, within the NEMORB project. The nonperturbative
nonlinear interplay of TAEs and EP due to the wave-particle nonlinearity is
studied. In particular, we focus on the nonlinear modification of the
frequency, growth rate and radial structure of the TAE, depending on the
evolution of the EP distribution in phase space. For the ITPA benchmark case,
we find that the frequency increases when the growth rate decreases, and the
mode shrinks radially. This nonlinear evolution is found to be correctly
reproduced by means of a quasilinear model, namely a model where the linear
effects of the nonlinearly modified EP distribution function are retained.


title: Fast Hierarchy Construction for Dense Subgraphs

abstract:
  Discovering dense subgraphs and understanding the relations among them is a
fundamental problem in graph mining. We want to not only identify dense
subgraphs, but also build a hierarchy among them (e.g., larger but sparser
subgraphs formed by two smaller dense subgraphs). Peeling algorithms (k-core,
k-truss, and nucleus decomposition) have been effective to locate many dense
subgraphs. However, constructing a hierarchical representation of density
structure, even correctly computing the connected k-cores and k-trusses, have
been mostly overlooked. Keeping track of connected components during peeling
requires an additional traversal operation, which is as expensive as the
peeling process. In this paper, we start with a thorough survey and point to
nuances in problem formulations that lead to significant differences in
runtimes. We then propose efficient and generic algorithms to construct the
hierarchy of dense subgraphs for k-core, k-truss, or any nucleus decomposition.
Our algorithms leverage the disjoint-set forest data structure to efficiently
construct the hierarchy during traversal. Furthermore, we introduce a new idea
to avoid traversal. We construct the subgraphs while visiting neighborhoods in
the peeling process, and build the relations to previously constructed
subgraphs. We also consider an existing idea to find the k-core hierarchy and
adapt for our objectives efficiently. Experiments on different types of large
scale real-world networks show significant speedups over naive algorithms and
existing alternatives. Our algorithms also outperform the hypothetical limits
of any possible traversal-based solution.


title: The Julia-Caratheodory theorem on the bidisk revisited

abstract:
  The Julia quotient measures the ratio of the distance of a function value
from the boundary to the distance from the boundary. The Julia-Carath\'eodory
theorem on the bidisk states that if the Julia quotient is bounded along some
sequence of nontangential approach to some point in the torus, the function
must have directional derivatives in all directions pointing into the bidisk.
The directional derivative, however, need not be a linear function of the
direction in that case. In this note, we show that if the Julia quotient is
uniformly bounded along every sequence of nontangential approach, the function
must have a linear directional derivative. Additionally, we analyze a weaker
condition, corresponding to being Lipschitz near the boundary, which implies
the existence of a linear directional derivative for rational functions.


title:
Constraints on tachyon inflationary models with an AdS/CFT
  correspondence

abstract:
  In order to study the effect of the anti de Sitter/ conformal field theory
correspondence (AdS/CFT) on the primordial inflationary era, we consider a
universe filled with a tachyon field in a slow-roll regime. In this context,
the background and perturbative parameters characterising the inflationary era
are related to the standard one by correction terms. We show a clear agreement
between the theoretical prediction and the observational data for the above
mentioned model. The main results of our work are illustrated for an
exponential potential. We show that, for a suitable conformal anomaly
coefficient, AdS/CFT correspondence might leave its imprints on the spectrum of
the gravitational waves amplitude with a tensor to scalar ratio, $r$, of the
perturbations compatible with Planck data.


title: Integrality estimates in orbits over function fields

abstract:
  We prove a version of Silverman's dynamical integral point theorem for a
large class of rational functions defined over global function fields.


title: Nevanlinna-Pick Kernels and Localization

abstract:
  We describe those reproducing kernel Hilbert spaces of holomorphic functions
on domains in ${\Bbb C}^d$ for which an analogue of the Nevanlinna-Pick theorem
holds, in other words when the existence of a (possibly matrix-valued) function
in the unit ball of the multiplier algebra with specified values on a finite
set of points is equivalent to the positvity of a related matrix. Our
description is in terms of a certain localization property of the kernel.


title:
Tunable metasurfaces via subwavelength phase shifters with uniform
  amplitude

abstract:
  Metasurfaces with tunable spatial phase functions could benefit numerous
applications. Currently, most approaches to tuning rely on mechanical
stretching which cannot control phase locally, or by modulating the refractive
index to exploit rapid phase changes with the drawback of also modulating
amplitude. Here, we propose a method to realize phase modulation at
subwavelength length scales while maintaining unity amplitude. Our device is
inspired by an asymmetric Fabry-Perot resonator, with pixels comprising a
scattering nanopost on top of a distributed Bragg reflector, capable of
providing a nearly 2{\pi} nonlinear phase shift with less than 2% refractive
index modulation. Using the designed pixels, we simulate a tunable metasurface
composed of an array of moderately coupled nanopost resonators, realizing
axicons, vortex beam generators, and aspherical lenses with both variable focal
length and in-plane scanning capability, achieving nearly diffraction-limited
performance. The experimental feasibility of the proposed method is also
discussed.


title: High-Pressure Hydrogen Sulfide by Diffusion Quantum Monte Carlo

abstract:
  We use the diffusion quantum Monte Carlo to revisit the enthalpy-pressure
phase diagram of the various products from the different proposed
decompositions of H$_2$S at pressures above 150~GPa. Our results entails a
revision of the ground-state enthalpy-pressure phase diagram. Specifically, we
find that the C2/c HS$_2$ structure is persistent up to 440~GPa before
undergoing a phase transition into the C2/m phase. Contrary to density
functional theory, our calculations suggest that the C2/m phase of HS is more
stable than the I4$_1$/amd HS structure over the whole pressure range from 150
to 400 GPa. Moreover, we predict that the Im-3m phase is the most likely
candidate for H$_3$S, which is consistent with recent experimental x-ray
diffraction measurements.


title: Four principles for quantum gravity

abstract:
  Four principles are proposed to underlie the quantum theory of gravity. We
show that these suffice to recover the Einstein equations. We also suggest that
MOND results from a modification of the classical equivalence principle, due to
quantum gravity effects.


title: DeepDGA: Adversarially-Tuned Domain Generation and Detection

abstract:
  Many malware families utilize domain generation algorithms (DGAs) to
establish command and control (C&C) connections. While there are many methods
to pseudorandomly generate domains, we focus in this paper on detecting (and
generating) domains on a per-domain basis which provides a simple and flexible
means to detect known DGA families. Recent machine learning approaches to DGA
detection have been successful on fairly simplistic DGAs, many of which produce
names of fixed length. However, models trained on limited datasets are somewhat
blind to new DGA variants.
  In this paper, we leverage the concept of generative adversarial networks to
construct a deep learning based DGA that is designed to intentionally bypass a
deep learning based detector. In a series of adversarial rounds, the generator
learns to generate domain names that are increasingly more difficult to detect.
In turn, a detector model updates its parameters to compensate for the
adversarially generated domains. We test the hypothesis of whether
adversarially generated domains may be used to augment training sets in order
to harden other machine learning models against yet-to-be-observed DGAs. We
detail solutions to several challenges in training this character-based
generative adversarial network (GAN). In particular, our deep learning
architecture begins as a domain name auto-encoder (encoder + decoder) trained
on domains in the Alexa one million. Then the encoder and decoder are
reassembled competitively in a generative adversarial network (detector +
generator), with novel neural architectures and training strategies to improve
convergence.


title: Adaptive Sequential Stochastic Optimization

abstract:
  A framework is introduced for sequentially solving convex stochastic
minimization problems, where the objective functions change slowly, in the
sense that the distance between successive minimizers is bounded. The
minimization problems are solved by sequentially applying a selected
optimization algorithm, such as stochastic gradient descent (SGD), based on
drawing a number of samples in order to carry the iterations. Two tracking
criteria are introduced to evaluate approximate minimizer quality: one based on
being accurate with respect to the mean trajectory, and the other based on
being accurate in high probability (IHP). An estimate of a bound on the
minimizers' change, combined with properties of the chosen optimization
algorithm, is used to select the number of samples needed to meet the desired
tracking criterion. A technique to estimate the change in minimizers is
provided along with analysis to show that eventually the estimate upper bounds
the change in minimizers. This estimate of the change in minimizers provides
sample size selection rules that guarantee that the tracking criterion is met
for sufficiently large number of time steps. Simulations are used to confirm
that the estimation approach provides the desired tracking accuracy in
practice, while being efficient in terms of number of samples used in each time
step.


title: Safe Human-Inspired Mesoscopic Hybrid Automaton for Autonomous Vehicles

abstract:
  In this paper a mesoscopic hybrid model, i.e. a microscopic hybrid model that
takes into account macroscopic parameters, is introduced for designing a
human-inspired Adaptive Cruise Control. A control law is proposed with the
design goal of replacing and imitating the behaviour of a human driver in a
car-following situation where lane changes are possible. First, a microscopic
hybrid automaton model is presented, based on human psycho-physical behavior,
for both longitudinal and lateral vehicle control. Then a rule for changing
time headway on the basis of macroscopic quantities is used to describe the
interaction among next vehicles and their impact on driver performance.
Simulation results show the advantages of the mesoscopic model. A feasibility
analysis of the needed communication network is also presented.


title:
Managing Information in Queues: The Impact of Giving Delayed Information
  to Customers

abstract:
  Delay or queue length information has the potential to influence the decision
of a customer to use a service system. Thus, it is imperative for service
system managers to understand how the information that they provide will affect
the performance of the system. To this end, we construct and analyze two
two-dimensional deterministic fluid models that incorporate customer choice
behavior based on delayed queue length information. In the first fluid model,
customers join each queue according to a Multinomial Logit Model, however, the
queue length information the customer receives is delayed by a constant
$\Delta$. We show that the delay can cause oscillations or asynchronous
behavior in the model based on the value of $\Delta$. In the second model,
customers receive information about the queue length through a moving average
of the queue length. Although it has been shown empirically that giving
patients moving average information causes oscillations and asynchronous
behavior to occur in U.S. hospitals in the work of Dong et al., we analytically
and mathematically show for the first time that the moving average fluid model
can exhibit oscillations and determine their dependence on the moving average
window. Thus, our analysis provides new insight on how managers of service
systems information systems should report queue length information to customers
and how delayed information can produce unwanted behavior.


title: Battery Capacity of Deferrable Energy Demand

abstract:
  We investigate the ability of a homogeneous collection of deferrable energy
loads to behave as a battery; that is, to absorb and release energy in a
controllable fashion up to fixed and predetermined limits on volume, charge
rate and discharge rate. We derive bounds on the battery capacity that can be
realized and show that there are fundamental trade-offs between battery
parameters. By characterizing the state trajectories under scheduling policies
that emulate two illustrative batteries, we show that the trade-offs occur
because the states that allow the loads to absorb and release energy at high
aggregate rates are conflicting.


title:
Correlations between critical parameters and bulk properties of nuclear
  matter

abstract:
  The present work starts by providing a clear identification of correlations
between critical parameters ($T_c$, $P_c$, $\rho_c$) and bulk quantities at
zero temperature of relativistic mean-field models (RMF) presenting third and
fourth order self-interactions in the scalar field $\sigma$. Motivated by the
nonrelativistic version of this RMF model, we show that effective nucleon mass
($M^*$) and incompressibility ($K_o$), at the saturation density, are
correlated with $T_c$, $P_c$, and $\rho_c$, as well as, binding energy and
saturation density itself. We verify agreement of results with previous
theoretical ones regarding different hadronic models. Concerning recent
experimental data of the symmetric nuclear matter critical parameters, our
study allows a prediction of $T_c$, $P_c$ and $\rho_c$ compatible with such
values, by combining them, through the correlations found, with previous
constraints related to $M^*$ and $K_o$. An improved RMF parametrization, that
better agrees with experimental values for $T_c$, is also indicated.


title: Schwarz lemma for conical K\"ahler metrics with general cone angles

abstract:
  The Schwarz--Pick lemma is a fundamental result in complex analysis. It is
well-known that Yau generalized it to the higher dimensional manifolds by
applying his maximum principle for complete Riemannian manifolds. Jeffres
obtained Schwarz lemma for volume forms of conical K\"ahler metrics, based on a
barrier function and the maximum principle argument. In this note, we
generalize Jeffres' result to general cone angles including the case when the
pullback of the metric would blows up along the divisors.


title:
K\"ahler manifolds with negative holomorphic sectional curvature,
  K\"ahler-Ricci flow approach

abstract:
  Recently, Wu-Yau and Tosatti-Yang established the connection between the
negativity of holomorphic sectional curvatures and the positivity of canonical
bundles for compact K\"ahler manifolds. In this short note, we give anothe
proof of their theorems by using the K\"ahler-Ricci flow.


title: Long-Lived Dust Asymmetries at Dead Zone Edges in Protoplanetary Disks

abstract:
  A number of transition disks exhibit significant azimuthal asymmetries in
thermal dust emission. One possible origin for these asymmetries is dust
trapping in vortices formed at the edges of dead zones. We carry out
high-resolution, two-dimensional hydrodynamic simulations of this scenario,
including the effects of dust feedback. We find that, although feedback weakens
the vortices and slows down the process of dust accumulation, the dust
distribution in the disk can nonetheless remain asymmetric for many thousands
of orbits. We show that even after $10^4$ orbits, or $2.5$ Myr when scaled to
the parameters of Oph IRS 48 (a significant fraction of its age), the dust is
not dispersed into an axisymmetric ring, in contrast to the case of a vortex
formed by a planet. This is because accumulation of mass at the dead zone edge
constantly replenishes the vortex, preventing it from being fully destroyed. We
produce synthetic dust emission images using our simulation results. We find
that multiple small clumps of dust may be distributed azimuthally. These
clumps, if not resolved from one another, appear as a single large feature. A
defining characteristic of a disk with a dead zone edge is that an asymmetric
feature is accompanied by a ring of dust located about twice as far from the
central star.


title:
Automorphisms and the fundamental operators associated with the
  symmetrized tridisc

abstract:
  The automorphisms of the symmetrized polydisc $\mathbb G_n$ are well-known
and are given in the coordinates of the polydisc in \cite{E:Z}. We find an
explicit formula for the automorphisms of $\mathbb G_n$ in its own coordinates.
If $\tau$ is an automorphism of $\mathbb G_n$, then $\tau(S_1,\dots,S_{n-1},P)$
is a $\Gamma_n$-contraction, where a $\Gamma_n$-contraction is a commuting
$n$-tuple of Hilbert space operators for which the closed symmetrized polydisc
$\Gamma_n$ is a spectral set. Corresponding to every $\Gamma_n$-contraction
$(S_1,\dots,S_{n-1},P)$, there exist $n-1$ unique operators $A_1,\dots,A_{n-1}$
such that \[ S_i-S_{n-i}^*P=D_PA_iD_P\,, \quad D_P=(I-P^*P)^{1/2}\,, \] for
$i=1,\dots, n-1$. This unique $(n-1)$-tuple $(A_1,\dots,A_{n-1})$, which is
called the fundamental operator tuple or $\mathcal F_O$-tuple of
$(S_1,\dots,S_{n-1},P)$ in literature, plays central role in every section of
operator theory on $\Gamma_n$. We find an explicit form of the $\mathcal
F_O$-tuple of $\tau (S_1,\dots,S_{n-1},P)$ when $n=3$. We show by an example
that a $\Gamma_n$-contraction may not have commuting $\mathcal F_O$-tuple.
Also, we obtain a necessary and sufficient condition under which two
$\Gamma_n$-contractions are unitarily equivalent.


title: A remark about critical sets in $R^3$

abstract:
  We give a necessary condition for a closed subset of $R^3$ to be the set of
critical points of some smooth function. In particular we obtain that for
example neither the Whitehead continuum nor the p-adic solenoid are such a
critical sets.


title: Polynomial-time Tensor Decompositions with Sum-of-Squares

abstract:
  We give new algorithms based on the sum-of-squares method for tensor
decomposition. Our results improve the best known running times from
quasi-polynomial to polynomial for several problems, including decomposing
random overcomplete 3-tensors and learning overcomplete dictionaries with
constant relative sparsity. We also give the first robust analysis for
decomposing overcomplete 4-tensors in the smoothed analysis model. A key
ingredient of our analysis is to establish small spectral gaps in moment
matrices derived from solutions to sum-of-squares relaxations. To enable this
analysis we augment sum-of-squares relaxations with spectral analogs of maximum
entropy constraints.


title: An Exposition of White's Characterization of Empty Lattice Tetrahedra

abstract:
  We give an exposition of White's characterization of empty lattice
tetrahedra. In particular, we describe the second author's proof of White's
theorem that appeared in her doctoral thesis.


title:
Quantum Game Theory for Beam Alignment in Millimeter Wave
  Device-to-Device Communications

abstract:
  In this paper, the problem of optimized beam alignment for wearable
device-to-device (D2D) communications over millimeter wave (mmW) frequencies is
studied. In particular, a noncooperative game is formulated between wearable
communication pairs that engage in D2D communications. In this game, wearable
devices acting as transmitters autonomously select the directions of their
beams so as to maximize the data rate to their receivers. To solve the game, an
algorithm based on best response dynamics is proposed that allows the
transmitters to reach a Nash equilibrium in a distributed manner. To further
improve the performance of mmW D2D communications, a novel quantum game model
is formulated to enable the wearable devices to exploit new quantum directions
during their beam alignment so as to further enhance their data rate.
Simulation results show that the proposed game-theoretic approach improves the
performance, in terms of data rate, of about 75% compared to a uniform beam
alignment. The results also show that the quantum game model can further yield
up to 20% improvement in data rates, relative to the classical game approach.


title:
Driving in the Matrix: Can Virtual Worlds Replace Human-Generated
  Annotations for Real World Tasks?

abstract:
  Deep learning has rapidly transformed the state of the art algorithms used to
address a variety of problems in computer vision and robotics. These
breakthroughs have relied upon massive amounts of human annotated training
data. This time consuming process has begun impeding the progress of these deep
learning efforts. This paper describes a method to incorporate photo-realistic
computer images from a simulation engine to rapidly generate annotated data
that can be used for the training of machine learning algorithms. We
demonstrate that a state of the art architecture, which is trained only using
these synthetic annotations, performs better than the identical architecture
trained on human annotated real-world data, when tested on the KITTI data set
for vehicle detection. By training machine learning algorithms on a rich
virtual world, real objects in real scenes can be learned and classified using
synthetic data. This approach offers the possibility of accelerating deep
learning's application to sensor-based classification problems like those that
appear in self-driving cars. The source code and data to train and validate the
networks described in this paper are made available for researchers.


title:
Orbits, Distance, and Stellar Masses of the Massive Triple Star Sigma
  Orionis

abstract:
  We present interferometric observations of the sigma Orionis triple system
using the CHARA Array, NPOI, and VLTI. Using these measurements, we spatially
resolve the orbit of the close spectroscopic binary (Aa,Ab) for the first time
and present a revised orbit for the wide pair (A,B). Combining the visual
orbits with previously published radial velocity measurements and new radial
velocities measured at CTIO, we derive dynamical masses for the three massive
stars in the system of M_Aa = 16.99 +/- 0.20 Msun, M_Ab = 12.81 +/- 0.18 Msun,
and M_B = 11.5 +/- 1.2 Msun. The inner and outer orbits in the triple are not
coplanar, with a relative inclination of 120-127 deg. The orbital parallax
provides a precise distance of 387.5 +/- 1.3 pc to the system. This is a
significant improvement over previous estimates of the distance to the young
sigma Orionis cluster.


title:
Hyperluminal Signatures in the Afterglows of Gamma-Ray Bursts 980425 and
  030329

abstract:
  The late-time high-resolution X-ray and radio observations of
GRB980425/SN1998bw, the closest known gamma ray burst (GRB) associated with a
supernova (SN) explosion, may have actually resolved the hyperluminal source
that produced the GRB and its afterglow. Its hyperluminal speed ~350c is
consistent with that expected in the cannonball (CB) model of GRBs. The
observed superluminal expansion of the late-time radio image of
GRB030329/SN2003dh, the GRB with the brightest and longest followed up radio
afterglow to date, is also consistent with that expected in the CB model of
GRBs and extrapolates to an apparent early-time hyperluminal expansion.


title: Active exploration in parameterized reinforcement learning

abstract:
  Online model-free reinforcement learning (RL) methods with continuous actions
are playing a prominent role when dealing with real-world applications such as
Robotics. However, when confronted to non-stationary environments, these
methods crucially rely on an exploration-exploitation trade-off which is rarely
dynamically and automatically adjusted to changes in the environment. Here we
propose an active exploration algorithm for RL in structured (parameterized)
continuous action space. This framework deals with a set of discrete actions,
each of which is parameterized with continuous variables. Discrete exploration
is controlled through a Boltzmann softmax function with an inverse temperature
$\beta$ parameter. In parallel, a Gaussian exploration is applied to the
continuous action parameters. We apply a meta-learning algorithm based on the
comparison between variations of short-term and long-term reward running
averages to simultaneously tune $\beta$ and the width of the Gaussian
distribution from which continuous action parameters are drawn. When applied to
a simple virtual human-robot interaction task, we show that this algorithm
outperforms continuous parameterized RL both without active exploration and
with active exploration based on uncertainty variations measured by a
Kalman-Q-learning algorithm.


title: Forbidden Patterns and the Alternating Derangement Sequence

abstract:
  In this note we count linear arrangements that avoid certain patterns and
show their connection to the derangement numbers. We discuss the sequence Dn,
which counts linear arrangements that avoid patterns 12, 23, ..., (n-1)n, n1,
and show that this sequence almost follows the derangement sequence itself
since the number of its odd terms is one more than the derangement numbers
while the number of its even terms is one less. We also express the derangement
numbers in terms of these and other arrangements.


title:
Fundamental properties of solutions to utility maximization problems in
  wireless networks

abstract:
  We introduce a unified framework for the study of the utility and the energy
efficiency of solutions to a large class of weighted max-min utility
maximization problems in interference-coupled wireless networks. In more
detail, given a network utility maximization problem parameterized by a maximum
power budget $\bar{p}$ available to network elements, we define two functions
that map the power budget $\bar{p}$ to the energy efficiency and to the utility
achieved by the solution. Among many interesting properties, we prove that
these functions are continuous and monotonic. In addition, we derive bounds
revealing that the solutions to utility maximization problems are characterized
by a low and a high power regime. In the low power regime, the energy
efficiency of the solution can decrease slowly as the power budget increases,
and the network utility grows linearly at best. In contrast, in the high power
regime, the energy efficiency typically scales as $\Theta(1/\bar{p})$ as
$\bar{p}\to\infty$, and the network utility scales as $\Theta(1)$. We apply the
theoretical findings to a novel weighted rate maximization problem involving
the joint optimization of the uplink power and the base station assignment.


title:
Regularized Dynamic Boltzmann Machine with Delay Pruning for
  Unsupervised Learning of Temporal Sequences

abstract:
  We introduce Delay Pruning, a simple yet powerful technique to regularize
dynamic Boltzmann machines (DyBM). The recently introduced DyBM provides a
particularly structured Boltzmann machine, as a generative model of a
multi-dimensional time-series. This Boltzmann machine can have infinitely many
layers of units but allows exact inference and learning based on its
biologically motivated structure. DyBM uses the idea of conduction delays in
the form of fixed length first-in first-out (FIFO) queues, with a neuron
connected to another via this FIFO queue, and spikes from a pre-synaptic neuron
travel along the queue to the post-synaptic neuron with a constant period of
delay. Here, we present Delay Pruning as a mechanism to prune the lengths of
the FIFO queues (making them zero) by setting some delay lengths to one with a
fixed probability, and finally selecting the best performing model with fixed
delays. The uniqueness of structure and a non-sampling based learning rule in
DyBM, make the application of previously proposed regularization techniques
like Dropout or DropConnect difficult, leading to poor generalization. First,
we evaluate the performance of Delay Pruning to let DyBM learn a
multidimensional temporal sequence generated by a Markov chain. Finally, we
show the effectiveness of delay pruning in learning high dimensional sequences
using the moving MNIST dataset, and compare it with Dropout and DropConnect
methods.


title:
Photon Detection Efficiency Measurements of the VERITAS Cherenkov
  Telescope Photomultipliers after four Years of Operation

abstract:
  The photon detection efficiency of two sets of R10560-100-20 superbialkali
photomultiplier tubes from Hamamatsu were measured between 200 nm and 750 nm to
quantify a possible degradation of the photocathode sensitivity after four
years of operation in the cameras of the VERITAS Cherenkov telescopes. A sample
of 20 photomultiplier tubes, which was removed from the telescopes was compared
with a sample of 20 spare photomultiplier tubes, which had been kept in
storage. It is found that the average photocathode sensitivity marginally
increased below 300 nm and dropped by 10% to 30% above 500 nm. The average
photocathode sensitivity folded with the Cherenkov spectrum emitted by
particles in air showers, however, reveals a consistent detection yield of
18.9+/-0.2% and 19.1+/-0.2% for the sample removed from the telescope and the
spare sample, respectively.


title:
How are galaxies assigned to halos? Searching for assembly bias in the
  SDSS galaxy clustering

abstract:
  Clustering of dark matter halos has been shown to depend on halo properties
beyond mass such as halo concentration, a phenomenon referred to as halo
assembly bias. Standard halo occupation models (HOD) in large scale structure
studies assume that halo mass alone is sufficient in characterizing the
connection between galaxies and halos. Modeling of galaxy clustering can face
systematic effects if the number of galaxies within a halo is correlated with
other halo properties. Using the Small MultiDark-Planck high resolution
$N$-body simulation and the clustering measurements of the Sloan Digital Sky
Survey (SDSS) DR7 main galaxy sample, we investigate the extent to which the
concentration-dependence of halo occupation can be constrained. Furthermore, we
study how allowing for the concentration dependence can improve our modeling of
galaxy clustering.
  Our constraints on HOD with assembly bias suggest that satellite population
is not correlated with halo concentration at fixed halo mass. At fixed halo
mass, our constraints favor lack of correlation between the occupation of
centrals and halo concentration in the most luminous samples ($M_{\rm
r}<-21.5,-21$), and modest correlation in the $M_{\rm r}<-20.5,-20, -19.5$
samples. We show that in comparison with abundance-matching mock catalogs, our
findings suggest qualitatively similar but modest levels of the impact of halo
assembly bias on galaxy clustering. The effect is only present in the central
occupation and becomes less significant in brighter galaxy samples.
Furthermore, by performing model comparison based on information criteria, we
find that in most cases, the standard mass-only HOD model is still favored by
the observations.


title: Tethered membranes do not remain flat for strong structural asymmetry

abstract:
  We set up the statistical mechanics for a nearly flat, thermally equilibrated
fluid membrane, attached to an elastic network through one of its sides. We
predict that the resulting structural (inversion) asymmetry of the membrane,
notably due to the elastic network attached to one of its sides, can generate a
local spontaneous curvature $C_0$, that may in turn destabilize the otherwise
flat membrane. As $C_0$ rises above a threshold at a fixed temperature, a flat
tethered membrane in the thermodynamic limit becomes structurally unstable,
signaling {\em crumpling} of the flat membrane. In-vitro experiments on red
blood cell membranes after depletion of adenosine-tri-phosphate molecules and
artificial deposition of spectrin filaments on lipid bilayers may be used to
verify our results.


title:
Partner selection supported by opaque reputation promotes cooperative
  behavior

abstract:
  Reputation plays a major role in human societies, and it has been proposed as
an explanation for the evolution of cooperation. While the majority of previous
studies equates reputation with a transparent and complete history of players'
past decisions, in real life, reputations are often ambiguous and opaque. Using
web-based experiments, we explore the extent to which opaque reputation works
in isolating defectors, with and without partner selection opportunities. Our
results show that low reputation works as a signal of untrustworthiness,
whereas medium or high reputation are not taken into account by participants
for orienting their choices. We also find that reputation without partner
selection does not promote cooperative behavior; that is, defectors do not turn
into cooperators only for the sake of getting a positive reputation. Finally,
in a third study, we find that, when reputation is pivotal to selection, then a
substantial proportion of would-be-defectors turn into cooperators. Taken
together, these results provide insights on the characteristics of reputation
and on the way in which humans make use of it when selecting partners but also
when knowing that they will be selected.


title: The ATLAS Insertable B-Layer: from construction to operation

abstract:
  The ATLAS Insertable B-Layer (IBL) is the innermost layer of pixel detectors,
and was installed in May 2014 at a radius of 3.3 cm from the beam axis, between
the existing Pixel detector and a new smaller radius beam-pipe. The new
detector, built to cope with high radiation and occupancy, is the first large
scale application of 3D sensors and CMOS 130 nm technology. The IBL detector
construction was completed within about two years (2012-2014), and the key
features and challenges met during the IBL project are presented, as well as
its commissioning and operational experience at the LHC.


title:
The molybdenum-titanium phase diagram evaluated from ab-initio
  calculations

abstract:
  The design of next generation \beta-type titanium implants requires detailed
knowledge of the relevant stable and metastable phases at temperatures where
metallurgical heat treatments can be performed. Recently, a standard
specification for surgical implant applications was established for Mo-Ti
alloys. However, the thermodynamic properties of this binary system are not
well known and two conflicting descriptions of the \beta-phase stability have
been presented in the literature. In this study, we use ab-initio calculations
to investigate the Mo-Ti phase diagram. These calculations predict that the
\beta-phase is stable over a wide concentration range, in qualitative agreement
with one of the reported phase diagrams. In addition, they predict
stoichiometric compounds, stable at temperatures below 3000C, which have not
yet been detected by experiments. The resulting solvus, which defines the
transition to the \beta-phase solid solution, therefore occurs at lower
temperatures and is more complex than previously anticipated.


title: Baryogenesis and Dark Matter in $U(1)$ Extensions

abstract:
  A brief review is given of some recent works where baryogenesis and dark
matter have a common origin within the $U(1)$ extensions of the standard model
and of the minimal supersymmetric standard model. The models considered
generate the desired baryon asymmetry and the dark matter to baryon ratio. In
one model all of the fundamental interactions do not violate lepton number, and
the total $B-L$ in the Universe vanishes. In addition, one may also generate a
normal hierarchy of neutrino masses and mixings in conformity with the current
data. Specifically one can accommodate $\theta_{13}\sim 9^{\circ}$ consistent
with the data from Daya Bay reactor neutrino experiment.


title: Complete Nevanlinna-Pick kernels

abstract:
  We give a new treatment of Quiggin's and McCullough's characterization of
complete Nevanlinna-Pick kernels. We show that a kernel has the matrix-valued
Nevanlinna-Pick property if and only if it has the vector-valued
Nevanlinna-Pick property. We give a representation of all complete
Nevanlinna-Pick kernels, and show that they are all restrictions of a universal
complete Nevanlinna-Pick kernel.


title:
Round Complexity in the Local Transformations of Quantum and Classical
  States

abstract:
  A natural operational paradigm for distributed quantum and classical
information processing involves local operations coordinated by multiple rounds
of public communication. In this paper we consider the minimum number of
communication rounds needed to perform the locality-constrained task of
entanglement transformation and the analogous classical task of secrecy
manipulation. Specifically we address whether bipartite mixed entanglement can
always be converted into pure entanglement or whether unsecure classical
correlations can always be transformed into secret shared randomness using
local operations and a bounded number of communication exchanges. Our main
contribution in this paper is an explicit construction of quantum and classical
state transformations which, for any given $r$, can be achieved using $r$
rounds of classical communication exchanges but no fewer. Our results reveal
that highly complex communication protocols are indeed necessary to fully
harness the information-theoretic resources contained in general quantum and
classical states. The major technical contribution of this manuscript lies in
proving lower bounds for the required number of communication exchanges using
the notion of common information and various lemmas built upon it. We propose a
classical analog to the Schmidt rank of a bipartite quantum state which we call
the secrecy rank, and we show that it is a monotone under stochastic local
classical operations.


title:
A global solution curve for a class of periodic problems, including the
  relativistic pendulum

abstract:
  Using continuation methods, we study the global solution structure of
periodic solutions for a class of periodically forced equations, generalizing
the case of relativistic pendulum. We obtain results on the existence and
multiplicity of periodic solutions. Our approach is suitable for numerical
computations, and in fact we present some numerically computed bifurcation
diagrams illustrating our results.


title: Analytic properties of the Virasoro modular kernel

abstract:
  On the space of generic conformal blocks the modular transformation of the
underlying surface is realized as a linear integral transformation. We show
that the analytic properties of conformal block implied by Zamolodchikov's
formula are shared by the kernel of the modular transformation and illustrate
this by explicit computation in the case of the one-point toric conformal
block.


title: Magnetic Purcell effect in nanophotonics

abstract:
  Tailoring of electromagnetic spontaneous emission predicted by E. M. Purcell
more than 50 years ago has undoubtedly proven to be one of the most important
effects in the rich areas of quantum optics and nanophotonics. Although during
the past decades the research in this field has been focused on electric dipole
emission, the recent progress in nanofabrication and study of magnetic quantum
emitters, such as rare-earth ions, has stimulated the investigation of the
magnetic side of spontaneous emission. Here, we review the state-of-the-art
advances in the field of spontaneous emission enhancement of magnetic dipole
quantum emitters with the use of various nanophotonics systems. We provide the
general theory describing the Purcell effect of magnetic emitters, overview
realizations of specific nanophotonics structures allowing for the enhanced
magnetic dipole spontaneous emission, and give an outlook on the challenges in
this field, which remain open to future research.


title: Anomalous oscillations of dark solitons in trapped dipolar condensates

abstract:
  Thanks to their immense purity and controllability, dipolar Bose-Einstein
condensates are an exemplar for studying fundamental non-local nonlinear
physics. Here we show that a family of fundamental nonlinear waves - the dark
solitons - are supported in trapped quasi-one-dimensional dipolar condensates
and within reach of current experiments. Remarkably, the oscillation frequency
of the soliton is strongly dependent on the atomic interactions, in stark
contrast to the non-dipolar case. The failure of a particle analogy, so
successful for dark solitons in general, to account for this behaviour implies
that these structures are inherently extended and non-particle-like. These
highly-sensitive waves may act as mesoscopic probes of the underlying quantum
matter field.


title: Scalable Machine Translation in Memory Constrained Environments

abstract:
  Machine translation is the discipline concerned with developing automated
tools for translating from one human language to another. Statistical machine
translation (SMT) is the dominant paradigm in this field. In SMT, translations
are generated by means of statistical models whose parameters are learned from
bilingual data. Scalability is a key concern in SMT, as one would like to make
use of as much data as possible to train better translation systems.
  In recent years, mobile devices with adequate computing power have become
widely available. Despite being very successful, mobile applications relying on
NLP systems continue to follow a client-server architecture, which is of
limited use because access to internet is often limited and expensive. The goal
of this dissertation is to show how to construct a scalable machine translation
system that can operate with the limited resources available on a mobile
device.
  The main challenge for porting translation systems on mobile devices is
memory usage. The amount of memory available on a mobile device is far less
than what is typically available on the server side of a client-server
application. In this thesis, we investigate alternatives for the two components
which prevent standard translation systems from working on mobile devices due
to high memory usage. We show that once these standard components are replaced
with our proposed alternatives, we obtain a scalable translation system that
can work on a device with limited memory.


title: Variable stars with the Kepler space telescope

abstract:
  The Kepler space telescope has revolutionised our knowledge about exoplanets
and stars and is continuing to do so in the K2 mission. The exquisite
photometric precision, together with the long, uninterrupted observations
opened up a new way to investigate the structure and evolution of stars.
Asteroseismology, the study of stellar oscillations, allowed us to investigate
solar-like stars and to peer into the insides of red giants and massive stars.
But many discoveries have been made about classical variable stars too, ranging
from pulsators like Cepheids and RR Lyraes to eclipsing binary stars and
cataclysmic variables, and even supernovae. In this review, which is far from
an exhaustive summary of all results obtained with Kepler, we collected some of
the most interesting discoveries, and ponder on the role for amateur observers
in this golden era of stellar astrophysics.


title:
Automated Phase Mapping with AgileFD and its Application to Light
  Absorber Discovery in the V-Mn-Nb Oxide System

abstract:
  Rapid construction of phase diagrams is a central tenet of combinatorial
materials science with accelerated materials discovery efforts often hampered
by challenges in interpreting combinatorial x-ray diffraction datasets, which
we address by developing AgileFD, an artificial intelligence algorithm that
enables rapid phase mapping from a combinatorial library of x-ray diffraction
patterns. AgileFD models alloying-based peak shifting through a novel expansion
of convolutional nonnegative matrix factorization, which not only improves the
identification of constituent phases but also maps their concentration and
lattice parameter as a function of composition. By incorporating Gibbs phase
rule into the algorithm, physically meaningful phase maps are obtained with
unsupervised operation, and more refined solutions are attained by injecting
expert knowledge of the system. The algorithm is demonstrated through
investigation of the V-Mn-Nb oxide system where decomposition of eight oxide
phases, including two with substantial alloying, provides the first phase map
for this pseudo-ternary system. This phase map enables interpretation of
high-throughput band gap data, leading to the discovery of new solar light
absorbers and the alloying-based tuning of the direct-allowed band-gap energy
of MnV2O6. The open-source family of AgileFD algorithms can be implemented into
a broad range of high throughput workflows to accelerate materials discovery.


title:
The Galois action and cohomology of a relative homology group of Fermat
  Curves

abstract:
  For an odd prime $p$ satisfying Vandiver's conjecture, we give explicit
formulae for the action of the absolute Galois group $G_{\mathbb{Q}(\zeta_p)}$
on the homology of the degree $p$ Fermat curve, building on work of Anderson.
Further, we study the invariants and the first Galois cohomology group which
are associated with obstructions to rational points on the Fermat curve.


title: Self-aligning concave relativistic plasma mirror with adjustable focus

abstract:
  We report an experimental-computational study of the optical properties of
plasma mirrors (PMs) at the incident laser frequency when irradiated directly
at relativistic intensity (1e18 < I_0 < 1e19 W/cm^2) by near-normally incident
(4 degree), high-contrast, 30 fs, 800 nm laser pulses. We find that such
relativistic PMs are highly reflective (0.6 to 0.8), and focus a significant
fraction of reflected light to intensity as large as 10I_0 at distance f as
small 25 microns from the PM, provided that pre-pulses do not exceed 1e14
W/cm^2 prior to 20 ps before arrival of the main pulse peak. Particle-in-cell
simulations show that focusing results from denting of the reflecting surface
by light pressure combined with relativistic transparency, and that
reflectivity and f can be adjusted by controlling pre-plasma length L over the
range 0.5 < L < 3 microns. Pump-probe reflectivity measurements show the PM's
focusing properties evolve on a ps time scale.


title:
CMV biorthogonal Laurent polynomials: Christoffel formulas for
  Christoffel and Geronimus perturbations

abstract:
  Quasidefinite sesquilinear forms for Laurent polynomials in the complex plane
and corresponding CMV biorthogonal Laurent polynomial families are studied.
Bivariate linear functionals encompass large families of orthogonalities like
Sobolev and discrete Sobolev types. Two possible Christoffel transformations of
these linear functionals are discussed. Either the linear functionals are
multiplied by a Laurent polynomial, or are multiplied by the complex conjugate
of a Laurent polynomial. For the Geronimus transformation, the linear
functional is perturbed in two possible manners as well, by a division by a
Laurent polynomial or by a complex conjugate of a Laurent polynomial, in both
cases the addition of appropriate masses (linear functionals supported on the
zeros of the perturbing Laurent polynomial) is considered. The connection
formulas for the CMV biorthogonal Laurent polynomials, its norms, and
Christoffel-Darboux kernels, in all the four cases, are given. For the
Geronimus transformation, the connection formulas for the second kind functions
and mixed Christoffel-Darboux kernels are also given in the two possible cases.
For prepared Laurent polynomials, i.e. of the form
$L(z)=L_nz^n+\cdots+L_{-n}z^{-n}$, $L_nL_{-n}\neq 0$, these connection formulas
lead to quasideterminantal (quotient of determinants) Christoffel formulas for
all the four transformations, expressing an arbitrary degree perturbed
biorthogonal Laurent polynomial in terms of $2n$ unperturbed biorthogonal
Laurent polynomials, their second kind functions or Christoffel-Darboux kernels
and its mixed versions. The unit circle case, given its exceptional properties,
is discussed in more detail.


title: Killing tensors on tori

abstract:
  We show that Killing tensors on conformally flat $n$-dimensional tori whose
conformal factor only depends on one variable, are polynomials in the metric
and in the Killing vector fields. In other words, every first integral of the
geodesic flow polynomial in the momenta on the sphere bundle of such a torus is
linear in the momenta.


title: Stable laws and cosmic ray physics

abstract:
  In the new precision era for cosmic ray astrophysics, theoretical predictions
cannot content themselves with average trends, but need to correctly take into
account intrinsic uncertainties. The space-time discreteness of the cosmic ray
sources, together with a substantial ignorance of their precise epochs and
locations (with the possible exception of the most recent and close ones) play
an important role in this sense. We elaborate a statistical theory to deal with
this problem, relating the composite probability P({\Psi}) to obtain a flux
{\Psi} at the Earth and the single-source probability p({\psi}) to contribute
with a flux {\psi}. The main difficulty arises from the fact that p({\psi}) is
a fat tail distribution, characterized by power-law or broken power-law
behavior up to very large fluxes for which central limit theorem does not hold,
and leading to well-known stable laws as opposed Gaussian. We find that
relatively simple recipes provide a satisfactory description of the probability
P({\Psi}). We also find that a naive Gaussian fit to simulation results would
underestimate the probability of very large fluxes, that is, several times
above the average, while overestimating the probability of relatively milder
excursions. At large energies, large flux fluctuations are prevented by causal
considerations, while at low energies a partial knowledge on the recent and
nearby population of sources plays an important role. A few proposal have been
discussed in the literature to account for spectral breaks recently reported in
cosmic ray data in terms of local contributions. We apply our newly developed
theory to assess their probabilities, finding that they are relatively small.


title:
Cherenkov and Scintillation Light Separation in Organic Liquid
  Scintillators

abstract:
  The CHErenkov / Scintillation Separation experiment (CHESS) has been used to
demonstrate the separation of Cherenkov and scintillation light in both linear
alkylbenzene (LAB) and LAB with 2g/L of PPO as a fluor (LAB/PPO). This is the
first such demonstration for the more challenging LAB/PPO cocktail and improves
on previous results for LAB. A time resolution of 338 +/- 12 ps FWHM results in
an efficiency for identifying Cherenkov photons in LAB/PPO of 70 +/- 3% and 63
+/- 8% for time- and charge-based separation, respectively, with scintillation
contamination of 36 +/- 5% and 38 +/- 4%. LAB/PPO data is consistent with a
rise time of 0.75 +/- 0.25 ns.


title: Fano q-reversal in topological insulator Bi2Se3

abstract:
  We studied magneto-optical response of a canonical topological insulator
Bi$_2$Se$_3$ with the goal of addressing a controversial issue of
electron-phonon coupling. Magnetic-field induced modifications of reflectance
are very pronounced in the infrared part of the spectrum, indicating strong
electron-phonon coupling. This coupling causes an asymmetric line-shape of the
60 cm$^{-1}$ phonon mode, and is analyzed within the Fano formalism. The
analysis reveals that the Fano asymmetry parameter (q) changes sign when the
cyclotron resonance is degenerate with the phonon mode. To the best of our
knowledge this is the first example of magnetic field driven q-reversal.


title:
A minimal, "hydrogen atom" version of an inversion-breaking Weyl
  semimetal

abstract:
  The recent explosion of research interest in Weyl semimetals has led to many
proposed Weyl semimetal candidates and a few experimental observations of a
Weyl semimetal in real materials. Through this experience, we have come to
appreciate that typical Weyl semimetals host many Weyl points. For instance,
the first Weyl semimetal observed in experiment, TaAs, hosts 24 Weyl points.
Similarly, the Mo$_x$W$_{1-x}$Te$_2$ series, recently under study as the first
Type II Weyl semimetal, has eight Weyl points. However, it is well-understood
that for a Weyl semimetal without inversion symmetry but with time-reversal
symmetry, the minimum number of Weyl points is four. Realizing such a minimal
Weyl semimetal is fundamentally relevant because it would offer the simplest
"hydrogen atom" example of an inversion-breaking Weyl semimetal. At the same
time, transport experiments and device applications may be simpler in a system
with as few Weyl points as possible. Recently, TaIrTe$_4$ has been predicted to
be a minimal, inversion-breaking Weyl semimetal. However, crucially, the Weyl
points and Fermi arcs live entirely above the Fermi level, making them
inaccessible to conventional angle-resolved photoemission spectroscopy (ARPES).
Here we use pump-probe ARPES to directly access the band structure above the
Fermi level in TaIrTe$_4$. We directly observe Weyl points and topological
Fermi arcs, showing that TaIrTe$_4$ is a Weyl semimetal. We find that, in
total, TaIrTe$_4$ has four Weyl points, providing the first example of a
minimal inversion-breaking Weyl semimetal. Our results hold promise for
accessing exotic transport phenomena arising in Weyl semimetals in a real
material.


title:
Approximating the XY model on a random graph with a $q$-state clock
  model

abstract:
  Numerical simulations of spin glass models with continuous variables set the
problem of a reliable but efficient discretization of such variables. In
particular, the main question is how fast physical observables computed in the
discretized model converge toward the ones of the continuous model when the
number of states of the discretized model increases. We answer this question
for the XY model and its discretization, the $q$-state clock model, in the
mean-field setting provided by random graphs. It is found that the convergence
of physical observables is exponentially fast in the number $q$ of states of
the clock model, so allowing a very reliable approximation of the XY model by
using a rather small number of states. Furthermore, such an exponential
convergence is found to be independent from the disorder distribution used.
Only at $T=0$ the convergence is slightly slower (stretched exponential).
Thanks to the analytical solution to the $q$-state clock model, we compute
accurate phase diagrams in the temperature versus disorder strength plane. We
find that, at zero temperature, spontaneous replica symmetry breaking takes
place for any amount of disorder, even an infinitesimal one. We also study the
one step of replica symmetry breaking (1RSB) solution in the low-temperature
spin glass phase.


title:
Cross-correlation between X-ray and optical/near-infrared background
  intensity fluctuations

abstract:
  Angular power spectra of optical and infrared background anisotropies at
wavelengths between 0.5 to 5 $\mu$m are a useful probe of faint sources present
during reionization, in addition to faint galaxies and diffuse signals at low
redshift. The cross-correlation of these fluctuations with backgrounds at other
wavelengths can be used to separate some of these signals. A previous study on
the cross-correlation between X-ray and $Spitzer$ fluctuations at 3.6 $\mu$m
and 4.5 $\mu$m has been interpreted as evidence for direct collapse blackholes
(DCBHs) present at $z > 12$. Here we return to this cross-correlation and study
its wavelength dependence from 0.5 to 4.5 $\mu$m using $Hubble$ and $Spitzer$
data in combination with a subset of the 4 Ms $Chandra$ observations in
GOODS-S/ECDFS. Our study involves five $Hubble$ bands at 0.6, 0.7, 0.85, 1.25
and 1.6 $\mu$m, and two $Spitzer$-IRAC bands at 3.6 $\mu$m and 4.5 $\mu$m. We
confirm the previously seen cross-correlation between 3.6 $\mu$m (4.5 $\mu$m)
and X-rays with 3.7$\sigma$ (4.2$\sigma$) and 2.7$\sigma$ (3.7$\sigma$)
detections in the soft [0.5-2] keV and hard [2-8] keV X-ray bands,
respectively, at angular scales above 20 arcseconds. The cross-correlation of
X-rays with $Hubble$ is largely anticorrelated, ranging between the levels of
1.4$-$3.5$\sigma$ for all the $Hubble$ and X-ray bands. This lack of
correlation in the shorter optical/NIR bands implies the sources responsible
for the cosmic infrared background at 3.6 and 4.5~$\mu$m are at least partly
dissimilar to those at 1.6 $\mu$m and shorter.


title:
The braingraph.org Database of High Resolution Structural Connectomes
  and the Brain Graph Tools

abstract:
  Based on the data of the NIH-funded Human Connectome Project, we have
computed structural connectomes of 426 human subjects in five different
resolutions of 83, 129, 234, 463 and 1015 nodes and several edge weights. The
graphs are given in anatomically annotated GraphML format that facilitates
better further processing and visualization. For 96 subjects, the anatomically
classified sub-graphs can also be accessed, formed from the vertices
corresponding to distinct lobes or even smaller regions of interests of the
brain. For example, one can easily download and study the connectomes,
restricted to the frontal lobes or just to the left precuneus of 96 subjects
using the data. Partially directed connectomes of 423 subjects are also
available for download. We also present a GitHub-deposited set of tools, called
the Brain Graph Tools, for several processing tasks of the connectomes on the
site \url{http://braingraph.org}.


title: Vinogradov's theorem with almost equal summands

abstract:
  Let $\theta > 11/20$. We prove that every sufficiently large odd integer $n$
can be written as a sum of three primes $n = p_1 + p_2 + p_3$ with $|p_i - n/3|
\leq n^{\theta}$ for $i\in\{1,2,3\}$.


title:
Role of exact exchange in thermally-assisted-occupation density
  functional theory: A proposal of new hybrid schemes

abstract:
  We propose hybrid schemes incorporating exact exchange into
thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai,
J. Chem. Phys. 136, 154104 (2012)] for an improved description of nonlocal
exchange effects. With a few simple modifications, global and range-separated
hybrid functionals in Kohn-Sham density functional theory (KS-DFT) can be
combined seamlessly with TAO-DFT. In comparison with global hybrid functionals
in KS-DFT, the resulting global hybrid functionals in TAO-DFT yield promising
performance for systems with strong static correlation effects (e.g., the
dissociation of H2 and N2, twisted ethylene, and electronic properties of
linear acenes), while maintaining similar performance for systems without
strong static correlation effects. Besides, a reasonably accurate description
of noncovalent interactions can be efficiently achieved through the inclusion
of dispersion corrections in hybrid TAO-DFT. Relative to semilocal density
functionals in TAO-DFT, global hybrid functionals in TAO-DFT are generally
superior in performance for a wide range of applications, such as
thermochemistry, kinetics, reaction energies, and optimized geometries.

categories: physics.chem-ph cond-mat.mtrl-sci physics.comp-ph quant-ph


title: Dynamical phase diagram of spin chains with long-range interactions

abstract:
  Using an infinite Matrix Product State (iMPS) technique based on the
time-dependent variational principle (TDVP), we study two major types of
dynamical phase transitions (DPT) in the one-dimensional transverse-field Ising
model (TFIM) with long-range power-law ($\propto1/r^{\alpha}$ with $r$
inter-spin distance) interactions out of equilibrium in the thermodynamic limit
-- \textit{DPT-I}: based on an order parameter in a (quasi-)steady state, and
\textit{DPT-II}: based on non-analyticities (cusps) in the Loschmidt-echo
return rate. We construct the corresponding rich dynamical phase diagram,
whilst considering different quench initial conditions. We find a nontrivial
connection between both types of DPT based on their critical lines. Moreover,
and very interestingly, we detect a new DPT-II dynamical phase in a certain
range of interaction exponent $\alpha$, characterized by what we call
\textit{anomalous cusps} that are distinct from the \textit{regular cusps}
usually associated with DPT-II. Our results provide the characterization of
experimentally accessible signatures of the dynamical phases studied in this
work.


title: $BF$ gravity

abstract:
  $BF$ gravity comprises all the formulations of gravity that are based on
deformations of $BF$ theory. Such deformations consist of either constraints or
potential terms added to the topological $BF$ action that turn some of the
gauge degrees of freedom into physical ones, particularly giving rise to
general relativity. The $BF$ formulations have provided new and deep insights
into many classical and quantum aspects of the gravitational field, setting the
foundations for the approach to quantum gravity known as spinfoam models. In
this review, we present a self-contained and unified treatment of the $BF$
formulations of $D$-dimensional general relativity and other related models,
focusing on the classical aspects of them and including some new results.


title: Ultra-low material pixel layers for the Mu3e experiment

abstract:
  The upcoming Mu3e experiment will search for the charged lepton flavour
violating decay of a muon at rest into three electrons. The maximal energy of
the electrons is 53 MeV, hence a low material budget is a key performance
requirement for the tracking detector. In this paper we summarize our approach
to meet the requirement of about 0.1 % of a radiation length per pixel detector
layer. This includes the choice of thinned active monolithic pixel sensors in
HV-CMOS technology, ultra-thin flexible printed circuits, and helium gas
cooling.


title:
Geometric decoding of subspace codes with explicit Schubert calculus
  applied to spread codes

abstract:
  This article is about a decoding algorithm for error-correcting subspace
codes. A version of this algorithm was previously described by Rosenthal,
Silberstein and Trautmann. The decoding algorithm requires the code to be
defined as the intersection of the Pl\"ucker embedding of the Grassmannian and
an algebraic variety. We call such codes \emph{geometric subspace codes}.
Complexity is substantially improved compared to the algorithm by Rosenthal,
Silberstein and Trautmann and connections to finite geometry are given. The
decoding algorithm is applied to Desarguesian spread codes, which are known to
be defined as the intersection of the Pl\"ucker embedding of the Grassmannian
with a linear space.


title: Holography, Hydrodynamization and Heavy-Ion Collisions

abstract:
  In the course of the past several years holography has emerged as an ab
initio tool in exploring strongly-time-dependent phenomena in gauge theories.
These lecture notes overview recent developments in this area driven by
phenomenological questions concerning applicability of hydrodynamics
(hydrodynamization) under extreme conditions occurring in ultrarelativistic
heavy-ion collisions at RHIC and LHC. The topics include hydrodynamization time
scale, holographic collisions, as well as hydrodynamization from the point of
view of the asymptotic character of the hydrodynamic gradient expansion. The
emphasis is put on concepts rather than calculational techniques and a
particular attention is devoted to present these developments in the context of
the most recent advances and some of the open problems.


title:
Competing Spin Liquid Phases in the S=$\frac{1}{2}$ Heisenberg Model on
  the Kagome Lattice

abstract:
  The properties of ground state of spin-$\frac{1}{2}$ kagome antiferromagnetic
Heisenberg (KAFH) model have attracted considerable interest in the past few
decades, and recent numerical simulations reported a spin liquid phase. The
nature of the spin liquid phase remains unclear. For instance, the interplay
between symmetries and $Z_2$ topological order leads to different types of
$Z_2$ spin liquid phases. In this paper, we develop a numerical simulation
method based on symmetric projected entangled-pair states (PEPS), which is
generally applicable to strongly correlated model systems in two spatial
dimensions. We then apply this method to study the nature of the ground state
of the KAFH model. Our results are consistent with that the ground state is a
$U(1)$ Dirac spin liquid rather than a $Z_2$ spin liquid.


title: Phenomenology of relaxion-Higgs mixing

abstract:
  We show that the relaxion generically stops its rolling at a point that
breaks CP leading to relaxion-Higgs mixing. This opens the door to a variety of
observational probes since the possible relaxion mass spans a broad range from
sub-eV to the GeV scale. We derive constraints from current experiments (fifth
force, astrophysical and cosmological probes, beam dump, flavour, LEP and LHC)
and present projections from future experiments such as NA62, SHiP and PIXIE.
We find that a large region of the parameter space is already under the
experimental scrutiny. All the experimental constraints we derive are equally
applicable for general Higgs portal models. In addition, we show that simple
multiaxion (clockwork) UV completions suffer from a mild fine tuning problem,
which increases with the number of sites. These results favour a cut-off scale
lower than the existing theoretical bounds.


title:
Two NIRCam channels are Better than One: How JWST Can Do More Science
  with NIRCam's Short-Wavelength Dispersed Hartmann Sensor

abstract:
  The James Webb Space Telescope (JWST) offers unprecedented sensitivity,
stability, and wavelength coverage for transiting exoplanet studies, opening up
new avenues for measuring atmospheric abundances, structure, and temperature
profiles. Taking full advantage of JWST spectroscopy of planets from 0.6um to
28um, however, will require many observations with a combination of the NIRISS,
NIRCam, NIRSpec, and MIRI instruments. In this white paper, we discuss a new
NIRCam mode (not yet approved or implemented) that can reduce the number of
necessary observations to cover the 1.0um to 5.0um wavelength range. Even
though NIRCam was designed primarily as an imager, it also includes several
grisms for phasing and aligning JWST's 18 hexagonal mirror segments. NIRCam's
long-wavelength channel includes grisms that cover 2.4um to 5.0um with a
resolving power of R = 1200 - 1550 using two separate configurations. The
long-wavelength grisms have already been approved for science operations,
including wide field and single object (time series) slitless spectroscopy. We
propose a new mode that will simultaneously measure spectra for science targets
in the 1.0um to 2.0um range using NIRCam's short-wavelength channel. This mode,
if approved, would take advantage of NIRCam's Dispersed Hartmann Sensor (DHS),
which produces 10 spatially separated spectra per source at R ~ 300. We discuss
the added benefit of the DHS in constraining abundances in exoplanet
atmospheres as well as its ability to observe the brightest systems. The DHS
essentially comes for free (at no time cost) with any NIRCam long-wavelength
grism observation, but the detector integration parameters have to be selected
to ensure that the long-wavelength grism observations do not saturate and that
JWST data volume downlink constraints are not violated.


title:
Drift-compensated Low-noise Frequency Synthesis Based on a cryoCSO for
  the KRISS-F1

abstract:
  In this paper we report on the implementation and stability analysis of a
drift-compensated frequency synthesizer from a cryogenic sapphire oscillator
(CSO) designed for a Cs/Rb atomic fountain clock. The synthesizer has two
microwave outputs of 7 GHz and 9 GHz for Rb and Cs atom interrogation,
respectively. The short-term stability of these microwave signals, measured
using an optical frequency comb locked to an ultra-stable laser, is better than
$5\times10^{-15}$ at an averaging time of 1 s. We demonstrate that the
short-term stability of the synthesizer is lower than the quantum projection
noise limit of the Cs fountain clock, KRISS-F1(Cs) by measuring the short-term
stability of the fountain with varying trapped atom number. The stability of
the fountain at 1-s averaging time reaches $2.5\times10^{-14}$ at the highest
atom number in the experiment when the synthesizer is used as an interrogation
oscillator of the fountain. In order to compensate the frequency drift of the
CSO, the output frequency of a waveform generator in the synthesis chain is
ramped linearly. By doing this, the stability of the synthesizer at an average
time of one hour reaches a level of $10^{-16}$ which is measured with the
fountain clock.


title: Viscosity of a net-baryon fluid near the QCD critical point

abstract:
  In the dynamics of the QCD critical point, the net-baryon fluid, linked to
the slow component of the order parameter, relaxes to a 3d Ising system in
equilibrium. An analytical study of shear and bulk viscosity, with constraints
imposed by the dynamics of the critical net-baryon fluid, the universality
property and the requirements of a class of strong coupling theories, is
performed in the neighbourhood of the critical point. It is found that the
shear viscosity of the net-baryon fluid is restricted in the domain $1.6\leq
4\pi\frac{\eta}{s}\leq 3.7$ for $T_c < T \leq 2T_c$ whereas the bulk viscosity
is small, $4\pi\frac{\zeta}{s} < 0.05$ (for $T>1.27 T_c$) but rising towards
the singularity at $T=T_c$.