title: Hall measurement of ultra thin vanadium dioxide thin films

abstract:
  In this work, we present the investigation of temperature dependent hall
measurement of the ultra thin VO$_2$ films grown on Si/SiO$_2$ substrate.
Experimental results suggest that electrons are the predominant carrier both in
the semiconducting and metallic phases. The decrease of the resistivity with
increasing temperature is mainly caused by the increase in the number density
of charge carriers. The temperature dependence of the carrier concentration
indicates the VO$_2$ films has a band gap of 0.40$\pm$0.09 $ev$ in the
semiconducting phase. Analysis of hall effect data based on a composite cube
model suggests that the sample has some untransitional phase with a length that
is 1/4 of the grains.


title:
Emergence of Dynamic Cooperativity in the Stochastic Kinetics of
  Fluctuating Enzymes

abstract:
  Dynamic cooperativity in monomeric enzymes is characterized in terms of a
non-Michaelis-Menten kinetic behaviour. The latter is believed to be associated
with mechanisms that include multiple reaction pathways due to enzymatic
conformational fluctuations. Recent advances in single-molecule fluorescence
spectroscopy have provided new fundamental insights on the possible mechanisms
underlying reactions catalyzed by fluctuating enzymes. Here, we present a
bottom-up approach to understand enzyme turnover kinetics at physiologically
relevant mesoscopic concentrations informed by mechanisms extracted from
single-molecule stochastic trajectories. The stochastic approach, presented
here, shows the emergence of dynamic cooperativity in terms of a slowing down
of the Michaelis-Menten (MM) kinetics resulting in negative cooperativity. For
fewer enzymes, dynamic cooperativity emerges due to the combined effects of
enzymatic conformational fluctuations and molecular discreteness. The increase
in the number of enzymes, however, suppresses the effect of enzymatic
conformational fluctuations such that dynamic cooperativity emerges solely due
to the discrete changes in the number of reacting species. These results
confirm that the turnover kinetics of fluctuating enzyme based on the
parallel-pathway MM mechanism switches over to the single-pathway MM mechanism
with the increase in the number of enzymes. For large enzyme numbers,
convergence to the exact MM equation occurs in the limit of very high substrate
concentration as the stochastic kinetics approaches the deterministic
behaviour.


title:
Distributed Association and Relaying with Fairness in Millimeter Wave
  Networks

abstract:
  Millimeter wave (mmWave) systems are emerging as an essential technology to
enable extremely high data rate wireless communications. The main limiting
factors of mmWave systems are blockage (high penetration loss) and deafness
(misalignment between the beams of the transmitter and receiver). To alleviate
these problems, it is imperative to incorporate efficient association and
relaying between terminals and access points. Unfortunately, the existing
association techniques are designed for the traditional interference-limited
networks, and thus are highly suboptimal for mmWave communications due to
narrow-beam operations and the resulting non-negligible interference-free
behavior. This paper introduces a distributed approach that solves the joint
association and relaying problem in mmWave networks considering the load
balancing at access points. The problem is posed as a novel stochastic
optimization problem, which is solved by distributed auction algorithms where
the clients and relays act asynchronously to achieve optimal
client-relay-access point association. It is shown that the algorithms provably
converge to a solution that maximizes the aggregate logarithmic utility within
a desired bound. Numerical results allow to quantify the performance
enhancements introduced by the relays, and the substantial improvements of the
network throughput and fairness among the clients by the proposed association
method as compared to standard approaches. It is concluded that mmWave
communications with proper association and relaying mechanisms can support
extremely high data rates, connection reliability, and fairness among the
clients.


title: I-convergence classes of sequences and nets in topological spaces

abstract:
  In this paper we have used the idea of I-convergence of sequences and nets to
study certain conditions of convergence in a topological space. It has been
shown separately that a class of sequences and a class of nets in a non-empty
set X which are respectively called I-convergence class of sequences and
I-convergence class of nets satisfying these conditions generate a topology on
X. Further we have correlated the classes of I-convergent sequences and nets
with respect to these topologies with the given classes which satisfy these
conditions.


title:
Integers representable as the product of the sum of four integers with
  the sum of their reciprocals

abstract:
  By the theory of elliptic curves, we study the integers representable as the
product of the sum of four integers with the sum of their reciprocals and give
a sufficient condition for the integers with a positive representation.


title: A Comparative Study of Long and Short GRBs. I. Overlapping Properties

abstract:
  Gamma ray bursts (GRBs) are classified into long and short categories based
on their durations. Broad band studies suggest that these two categories of
objects roughly correspond to two different classes of progenitor systems, i.e.
compact star mergers (Type I) vs. massive star core collapse (Type II).
However, the duration criterion sometimes leads to mis-identification of the
progenitor systems. We perform a comprehensive multi-wavelength comparative
study between duration-defined long GRBs and short GRBs as well as the
so-called "consensus" long GRBs and short GRBs (which are believed to be more
closely related to the two types of progenitor systems). The parameters we
study include two parts: the prompt emission properties including duration
($T_{90}$), spectral peak energy ($E_{\rm p}$), low energy photon index
($\alpha$), isotropic $\gamma$-ray energy ($E_{\rm \gamma, iso}$), isotropic
peak luminosity ($L_{\rm p,iso}$), and the amplitude parameters ($f$ and
$f_{\rm eff}$); and the host galaxy properties including stellar mass ($M_*$),
star formation rate (SFR), metallicity ([X/H]), half light radius ($R_{50}$),
angular and physical ($R_{\rm off}$) offset of the afterglow from the center of
the host galaxy, the normalized offset ($r_{\rm off}=R_{\rm off}/R_{50}$), and
the brightness fraction $F_{\rm light}$. For most parameters, we find
interesting overlapping properties between the two populations in both 1D and
2D distribution plots. The three best parameters for the classification purpose
are $T_{90}$, $f_{\rm eff}$, and $F_{\rm light}$. However, no single parameter
alone is good enough to place a particular burst into the right physical
category, suggesting a need of multiple criteria for physical classification.


title: The DFS Fused Lasso: Linear-Time Denoising over General Graphs

abstract:
  The fused lasso, also known as (anisotropic) total variation denoising, is
widely used for piecewise constant signal estimation with respect to a given
undirected graph. The fused lasso estimate is highly nontrivial to compute when
the underlying graph is large and has an arbitrary structure. But for a special
graph structure, namely, the chain graph, the fused lasso---or simply, 1d fused
lasso---can be computed in linear time. In this paper, we establish a
surprising connection between the total variation of a generic signal defined
over an arbitrary graph, and the total variation of this signal over a chain
graph induced by running depth-first search (DFS) over the nodes of the graph.
Specifically, we prove that for any signal, its total variation over the
induced chain graph is no more than twice its total variation over the original
graph. This connection leads to several interesting theoretical and
computational conclusions. Denoting by $m$ and $n$ the number of edges and
nodes, respectively, of the graph in question, our result implies that for an
underlying signal with total variation $t$ over the graph, the fused lasso
achieves a mean squared error rate of \smash{$t^{2/3} n^{-2/3}$}. Moreover,
precisely the same mean squared error rate is achieved by running the 1d fused
lasso on the induced chain graph from running DFS. Importantly, the latter
estimator is simple and computationally cheap, requiring only $O(m)$ operations
for constructing the DFS-induced chain and $O(n)$ operations for computing the
1d fused lasso solution over this chain. Further, for trees that have bounded
max degree, the error rate of \smash{$t^{2/3} n^{-2/3}$} cannot be improved, in
the sense that it is the minimax rate for signals that have total variation $t$
over the tree.


title:
Analytic solutions for the approximated 1-D Kantorovich mass transfer
  problems

abstract:
  This paper mainly investigates the approximation of a global maximizer of the
1-D Monge-Kantorovich mass transfer problem through the approach of nonlinear
differential equations with Dirichlet boundary. Using an approximation
mechanism, the primal maximization problem can be transformed into a sequence
of minimization problems. By applying the canonical duality theory, one is able
to derive a sequence of analytic solutions for the minimization problems. In
the final analysis, the convergence of the sequence to a global maximizer of
the primal Monge-Kantorovich problem will be demonstrated.


title: Gravitino production in a thermal Universe revisited

abstract:
  We study the production of spin 1/2 gravitinos in a thermal Universe. Taking
into account supersymmetry breaking due to the finite thermal energy density of
the Universe, there is a large enhancement in the cross section of production
of these gravitino states. We consider gravitinos with zero temperature masses
of 0.1 eV, 1 keV, 100 GeV and 30 TeV as representative of gauge mediated,
gravity mediated and anomaly mediated supersymmetry breaking scenarios. We find
that the abundance of gravitinos produced in the early Universe is very high
for gravitinos of mass 1 keV and 100 GeV. The gravitino abundances can be
sufficiently suppressed if the reheat temperature is less than 100 GeV and
$4\cdot 10^4$ gev respectively. However such low reheat temperatures will rule
out many models of baryogenesis including those via leptogenesis.


title:
One-dimensional hard-core anyon gas in a harmonic trap at finite
  temperature

abstract:
  We investigate the strongly interacting hard-core anyon gases in a one
dimensional harmonic potential at finite temperature by extending thermal
Bose-Fermi mapping method to thermal anyon-ferimon mapping method. With thermal
anyon-fermion mapping method we obtain the reduced one-body density matrix and
therefore the momentum distribution for different statistical parameters and
temperatures. At low temperature hard-core anyon gases exhibit the similar
properties as those of ground state, which interpolate between Bose-like and
Fermi-like continuously with the evolution of statistical properties. At high
temperature hard-core anyon gases of different statistical properties display
the same reduced one-body density matrix and momentum distribution as those of
spin-polarized fermions. The Tan's contact of hard-core anyon gas at finite
temperature is also evaluated, which take the simple relation with that of
Tonks-Girardeau gas $C_b$ as $C=\frac12(1-cos\chi\pi)C_b$.


title: Magnetic Moments of Octet Baryons in Hot and Dense Nuclear Matter

abstract:
  We have calculated the in-medium magnetic moments of octet baryons in the
presence of hot and dense symmetric nuclear matter. Effective magnetic moments
of baryons have been derived from medium modified quark masses within chiral
SU(3) quark mean field model.
  Further, for better insight of medium modification of baryonic magnetic
moments, we have considered the explicit contributions from the valence quarks,
sea quarks as well as sea orbital angular momentum of sea quarks. These effects
have been successful in giving the description of baryonic magnetic moments in
vacuum.
  The magnetic moments of baryons are found to vary significantly as a function
of density of nuclear medium.


title:
$L^p$-$L^q$ decay estimates for dissipative linear hyperbolic systems in
  1D

abstract:
  Given $A,B\in M_n(\mathbb R)$, we consider the Cauchy problem for partially
dissipative hyperbolic systems having the form \begin{equation*}
  \partial_{t}u+A\partial_{x}u+Bu=0, \end{equation*} with the aim of providing
a detailed description of the large-time behavior. Sharp $L^p$-$L^q$ estimates
are established for the distance between the solution to the system and a
time-asymptotic profile, where the profile is the superposition of diffusion
waves and exponentially decaying waves.


title:
Full-disk Synoptic Observations of the Chromosphere Using H$_{\alpha}$
  Telescope at the Kodaikanal Observatory

abstract:
  This paper reports on the installation and observations of a new solar
telescope installed on 7th October, 2014 at the Kodaikanal Observatory. The
telescope is a refractive type equipped with a tunable Lyot H$_{\alpha}$
filter. A CCD camera of 2k$\times$2k size makes the image of the Sun with a
pixel size of 1.21$^{\prime\prime}$ pixel$^{-1}$ with a full field-of-view of
41$^{\prime}$. The telescope is equipped with a guiding system which keeps the
image of the Sun within a few pixels throughout the observations. The FWHM of
the Lyot filter is 0.4\AA~and the filter is motorized, capable of scanning the
H$_{\alpha}$ line profile at a smaller step size of 0.01\AA. Partial-disk
imaging covering about 10$^{\prime}$, is also possible with the help of a relay
lens kept in front of the CCD camera. In this paper, we report the detailed
specifications of the telescope, filter unit, its installation, observations
and the procedures we have followed to calibrate and align the data. We also
present preliminary results with this new full-disk telescope.


title: Page curves for tripartite systems

abstract:
  We investigate information flow and Page curves for tripartite systems. We
prepare a tripartite system (say, A, B, and C) of a given number of states and
calculate information and entropy contents by assuming random states.
Initially, every particle was in A (this means a black hole), and as time goes
on, particles move to either B (means Hawking radiation) or C (means a broadly
defined remnant, including a non-local transport of information, the last
burst, an interior large volume, or a bubble universe, etc.). If the final
number of states of the remnant is smaller than that of Hawking radiation, then
information will be stored by both of the radiation and the mutual information
between the radiation and the remnant, while the remnant itself does not
contain information. On the other hand, if the final number of states of the
remnant is greater than that of Hawking radiation, then the radiation contains
negligible information, while the remnant and the mutual information between
the radiation and the remnant contain information. Unless the number of states
of the remnant is large enough compared to the entropy of the black hole,
Hawking radiation must contain information; and we meet the menace of black
hole complementarity again. Therefore, this contrasts the tension between
various assumptions and candidates of the resolution of the information loss
problem.


title: Graphs and spherical two-distance sets

abstract:
  Every graph G can be embedded in a Euclidean space as a two-distance set. The
Euclidean representation number of G is the smallest dimension in which G is
representable by such an embedding. We consider spherical and J-spherical
representation numbers of G and give exact formulas for these numbers using
multiplicities of polynomials that are defined by the Caley-Menger determinant.
One of the main results of the paper are explicit formulas for the
representation numbers of the join of graphs which are obtained from W.
Kuperberg's type theorem for two-distance sets.


title:
A penalized method for multivariate concave least squares with
  application to productivity analysis

abstract:
  We propose a penalized method for the least squares estimator of a
multivariate concave regression function. This estimator is formulated as a
quadratic programming (QP) problem with $O(n^2)$ constraints, where n is the
number of observations. Computing such an estimator is a very time-consuming
task, and the computational burden rises dramatically as the number of
observations increases. By introducing a quadratic penalty function, we
reformulate the concave least squares estimator as a QP with only
non-negativity constraints. This reformulation can be adapted for estimating
variants of shape restricted least squares, i.e. the monotonic-concave/convex
least squares. The experimental results and an empirical study show that the
reformulated problem and its dual are solved significantly faster than the
original problem. The Matlab and R codes for implementing the penalized
problems are provided in the paper.


title:
Multiple-parameter bifurcation analysis in a Kuramoto model with time
  delay and distributed shear

abstract:
  In this paper, time delay effect and distributed shear are considered in the
Kuramoto model. On the Ott-Antonsen's manifold, through analyzing the
associated characteristic equation of the reduced functional differential
equation, the stability boundary of the incoherent state is derived in
multiple-parameter space. Moreover, very rich dynamical behavior such as
stability switches inducing synchronization switches can occur in this
equation. With the loss of stability, Hopf bifurcating coherent states arise,
and the criticality of Hopf bifurcations is determined by applying the normal
form theory and the center manifold theorem. On one hand, theoretical analysis
indicates that the width of shear distribution and time delay can both
eliminate the synchronization then lead the Kuramoto model to incoherence. On
the other, time delay can induce several coexisting coherent states. Finally,
some numerical simulations are given to support the obtained results where
several bifurcation diagrams are drawn, and the effect of time delay and shear
is discussed.


title: Topological superconductors: a review

abstract:
  This review elaborates pedagogically on the fundamental concept, basic
theory, expected properties, and materials realizations of topological
superconductors. The relation between topological superconductivity and
Majorana fermions are explained, and the difference between dispersive Majorana
fermions and a localized Majorana zero mode is emphasized. A variety of routes
to topological superconductivity are explained with an emphasis on the roles of
spin-orbit coupling. Present experimental situations and possible signatures of
topological superconductivity are summarized with an emphasis on intrinsic
topological superconductors.


title:
A machine learning method for the large-scale evaluation of urban visual
  environment

abstract:
  Given the size of modern cities in the urbanising age, it is beyond the
perceptual capacity of most people to develop a good knowledge about the beauty
and ugliness of the city at every street corner. Correspondingly, for planners,
it is also difficult to accurately answer questions like 'where are the
worst-looking places in the city that regeneration should give first
consideration', or 'in the fast urbanising cities, how is the city appearance
changing', etc. To address this issue, we here present a computer vision method
for the large-scale and automatic evaluation of the urban visual environment,
by leveraging state-of-the-art machine learning techniques and the
wide-coverage street view images. From the various factors that are at work, we
choose two key features, the visual quality of street facade and the continuity
of street wall, as the starting point of this line of analysis. In order to
test the validity of this method, we further compare the machine ratings with
ratings collected on site from 752 passers-by on fifty-six locations. We show
that the machine learning model can produce a good estimation of people's real
visual experience, and it holds much potential for various tasks in terms of
urban design evaluation, culture identification, etc.


title: Dynamic routing for social information sharing

abstract:
  Today mobile users are intensively interconnected thanks to the emerging
mobile social networks, where they share location-based information with each
other when traveling on different routes and visit different areas of the city.
In our model the information collected is aggregated over all users' trips and
made publicly available as a public good. Due to information overlap, the total
useful content amount increases with the diversity in path choices made by the
users, and it is crucial to motivate selfish users to choose different paths
despite the potentially higher costs associated with their trips. In this paper
we combine the benefits from social information sharing with the fundamental
routing problem where a unit mass of non-atomic selfish users decide their
trips in a non-cooperative game by choosing between a high-cost and a low-cost
path. To remedy the inefficient low-content equilibrium where all users choose
to explore a single path (the low-cost path), we propose and analyse two new
incentive mechanisms that can be used by the social network application, one
based on side payments and the other on restricting access to content for users
that choose the low cost path. We also obtain interesting price of anarchy
results that show some fundamental tradeoffs between achieving path diversity
and maintaining greater user participation, motivating a combined mechanism to
further increase the social welfare. Our model extends classical dynamic
routing in the case of externalities caused from traffic on different paths of
the network.


title: Robust Relativistic Bit Commitment

abstract:
  Relativistic cryptography exploits the fact that no information can travel
faster than the speed of light in order to obtain security guarantees that
cannot be achieved from the laws of quantum mechanics alone. Recently, Lunghi
et al [Phys. Rev. Lett. 2015] presented a bit commitment scheme where each
party uses two agents that exchange classical information in a synchronized
fashion, and that is both hiding and binding. A caveat is that the commitment
time is intrinsically limited by the spatial configuration of the players, and
increasing this time requires the agents to exchange messages during the whole
duration of the protocol. While such a solution remains computationally
attractive, its practicality is severely limited in realistic settings since
all communication must remain perfectly synchronized at all times.
  In this work, we introduce a robust protocol for relativistic bit commitment
that tolerates failures of the classical communication network. This is done by
adding a third agent to both parties. Our scheme provides a quadratic
improvement in terms of expected sustain time compared to the original
protocol, while retaining the same level of security.


title:
Minority spin dynamics in non-homogeneous Ising model: diverging
  timescales and exponents

abstract:
  We investigate the dynamical behaviour of the Ising model under a zero
temperature quench with the initial fraction of up spins $0\leq x\leq 1$. In
one dimension, the known results for persistence probability are verified; it
shows algebraic decay for both up and down spins asymptotically with different
exponents. It is found that the conventional finite size scaling is valid here.
In two dimensions however, the persistence probabilities are no longer
algebraic; in particular for $x\leq 0.5$, persistence for the up (minority)
spins shows the behaviour $P_{min}(t) \sim t^{-\gamma}\exp(-(t/\tau)^{\delta})$
with time $t$, while for the down (majority) spins, $P_{maj}(t)$ approaches a
finite value. We find that the timescale $\tau$ diverges as $(x_c-x)^{-
\lambda}$, where $x_c=0.5$ and $\lambda\simeq2.31$. The exponent $\gamma$
varies as $\theta_{2d}+c_0(x_c-x)^{\beta}$ where $\theta_{2d}\simeq0.215$ is
very close to the persistence exponent in two dimensions; $\beta\simeq1$. The
results in two dimensions can be understood qualitatively by studying the exit
probability, which for different system size is found to have the form $E(x) =
f\big[(\frac{x-x_c}{x_c})L^{1/\nu}\big]$, with $\nu \approx 1.47$. This result
suggests that $\tau \sim L^{\tilde{z}}$, where $\tilde{z} = \frac{\lambda}{\nu}
= 1.57 \pm 0.11$ is an exponent not explored earlier.


title: Mermin pentagrams arising from Veldkamp lines for three qubits

abstract:
  We study the geometry of the space of Mermin pentagrams, objects that are
used to rule out the existence of noncontextual hidden variable theories as
alternatives to quantum theory. It is shown that this space of 12096 possible
pentagrams is organized into 1008 families, with each family containing a
"double six" of pentagrams. The 1008 families are connected to a special set of
Veldkamp lines in the Veldkamp space of three qubits an object well-known to
finite geometers but has only been introduced to physics recently. Due to the
transitive action of the symplectic group on this set of Veldkamp lines it is
enough to study only one "canonical" double six configuration of pentagrams. We
prove that the geometry of this double-six configuration is encapsulated in the
weight diagram of the 20 dimensional irreducible representation of the group
$SU(6)$. As an interesting by-product of our approach we show that Mermin
pentagrams and a class of Mermin squares labelled by three qubit Pauli
operators are inherently related. We conjecture that by studying the
representation theoretic content of other Veldkamp lines of the Veldkamp space
for $N$-qubits makes it possible to find new contextual configurations in a
systematic manner.


title:
Determination of optimal reversed field with maximal electrocaloric
  cooling by a direct entropy analysis

abstract:
  Application of a negative field on a positively poled ferroelectric sample
can enhance the electrocaloric cooling and appears as a promising method to
optimize the electrocaloric cycle. Experimental measurements show that the
maximal cooling does not appear at the zero-polarization point, but around the
shoulder of the P-E loop. This phenomenon cannot be explained by the theory
based on the constant total entropy assumption under adiabatic condition. In
fact, adiabatic condition does not imply constant total entropy when
irreversibility is involved. A direct entropy analysis approach based on work
loss is proposed in this work, which takes the entropy contribution of the
irreversible process into account. The optimal reversed field determined by
this approach agrees with the experimental observations. This study signifies
the importance of considering the irreversible process in the electrocaloric
cycles.


title: Convexity in complex networks

abstract:
  Metric graph properties lie in the heart of the analysis of complex networks,
while in this paper we study their convexity through mathematical definition of
a convex subgraph. A subgraph is convex if every geodesic path between the
nodes of the subgraph lies entirely within the subgraph. According to our
perception of convexity, convex network is such in which every connected subset
of nodes induces a convex subgraph. We show that convexity is an inherent
property of many networks that is not present in a random graph. Most convex
are spatial infrastructure networks and social collaboration graphs due to
their tree-like or clique-like structure, whereas the food web is the only
network studied that is truly non-convex. Core-periphery networks are
regionally convex as they can be divided into a non-convex core surrounded by a
convex periphery. Random graphs, however, are only locally convex meaning that
any connected subgraph of size smaller than the average geodesic distance
between the nodes is almost certainly convex. We present different measures of
network convexity and discuss its applications in the study of networks.


title:
The Effect of the AGN Feedback on the Interstellar Medium of Early-Type
  Galaxies: 2D Hydrodynamical Simulations of the Low-Rotation Case

abstract:
  We present 2D hydrodynamical simulations for the evolution of early-type
galaxies containing central massive black holes (MBHs), starting at age 2 Gyr.
The code contains accurate and physically consistent radiative and mechanical
AGN wind feedback, with parsec-scale central resolution. Mass input comes from
stellar evolution; energy input includes Type Ia and II supernova and stellar
heating; star-formation is included. Realistic, axisymmetric dynamical models
for the galaxies are built solving the Jeans' equations. The lowest mass models
(Mstar = 8 10^{10}Msun) develop global outflows sustained by SNIa's heating,
ending with a significantly lower amount of hot gas and new stars. In more
massive models, nuclear outbursts last to the present epoch, with large and
frequent fluctuations in nuclear emission and from the gas (Lx). Each burst
last ~ 10^{7.5} yr, during which (for r < 2-3 kpc) cold, inflowing, and hot,
outflowing gas phases coexist. The Lx-T relation for the gas matches that of
local galaxies. AGN activity causes positive feedback for star formation.
Roughly half of the total mass loss is recycled into new stars (DeltaMstar),
just ~ 3% of it is accreted on the MBH, the remainder being ejected from the
galaxy. The ratio between the mass of gas expelled to that in to new stars, the
load factor, is ~0.6. Rounder galaxies shapes lead to larger final MBH masses,
DeltaMstar, and Lx. Almost all the time is spent at very low nuclear
luminosities, yet one quarter of the total energy is emitted at an Eddington
ratio > 0.1. The duty-cycle of AGN activity approximates 4% (Abridged).


title:
Topological Weyl semimetals in the chiral antiferromagnetic materials
  Mn3Ge and Mn3Sn

abstract:
  Recent experiments revealed that Mn3Sn and Mn3Ge exhibit a strong anomalous
Hall effect at room temperature, provoking us to explore their electronic
structures for topological properties. By ab initio band structure
calculations, we have observed the existence of multiple Weyl points in the
bulk and corresponding Fermi arcs on the surface, predicting antiferromagnetic
Weyl semimetals in Mn3Ge and Mn3Sn. Here the chiral antiferromagnetism in the
Kagome-type lattice structure is essential to determine the positions and
numbers of Weyl points. Our work further reveals a new guiding principle to
search for magnetic Weyl semimetals among materials that exhibit a strong
anomalous Hall effect.


title: Building ArtBots to Attract Students into STEM Learning

abstract:
  There is an increasing worldwide demand for people educated into science and
technology. Unfortunately, girls and underprivileged students are often
underrepresented in Science, Technology, Engineering and Mathematics (STEM)
education programs. We believe that by inclusion of art in these programs,
educational activities might become more attractive to a broader audience. In
this work we present an example of such an educational activity: an
international robotics and art week for secondary school students. This
educational activity builds up on the project-based and inquiry learning
framework. This article is intended as a brief manual to help others organise
such an activity. It also gives insights in how we led a highly heterogeneous
group of students into learning STEM and becoming science and technology
ambassadors for their peers.


title: Remarks on Xiao's approach of Slope inequalities

abstract:
  We prove the slope inequality for a relative minimal surface fibration in
positive characteristic via Xiao's approach. We also prove a better low bound
for the slope of non-hyperelliptic fibrations.


title: Janus spectra in two-dimensional flows

abstract:
  In theory, large-scale atmospheric flows, soap-film flows and other
two-dimensional flows may host two distinct types of turbulent energy
spectra---in one, $\alpha$, the spectral exponent of velocity fluctuations,
equals $3$ and the fluctuations are dissipated at the small scales, and in the
other, $\alpha=5/3$ and the fluctuations are dissipated at the large
scales---but measurements downstream of obstacles have invariably revealed
$\alpha = 3$. Here we report experiments on soap-film flows where downstream of
obstacles there exists a sizable interval in which $\alpha$ has transitioned
from $3$ to $5/3$ for the streamwise fluctuations but remains equal to $3$ for
the transverse fluctuations, as if two mutually independent turbulent fields of
disparate dynamics were concurrently active within the flow. This species of
turbulent energy spectra, which we term the Janus spectra, has never been
observed or predicted theoretically. Our results may open up new vistas in the
study of turbulence and geophysical flows.


title: The Cadmium Zinc Telluride Imager on AstroSat

abstract:
  The Cadmium Zinc Telluride Imager (CZTI) is a high energy, wide-field imaging
instrument on AstroSat. CZT's namesake Cadmium Zinc Telluride detectors cover
an energy range from 20 keV to > 200 keV, with 11% energy resolution at 60 keV.
The coded aperture mask attains an angular resolution of 17' over a 4.6 deg x
4.6 deg (FWHM) field of view. CZTI functions as an open detector above 100 keV,
continuously sensitive to GRBs and other transients in about 30% of the sky.
The pixellated detectors are sensitive to polarisation above ~100 keV, with
exciting possibilities for polarisation studies of transients and bright
persistent sources. In this paper, we provide details of the complete CZTI
instrument, detectors, coded aperture mask, mechanical and electronic
configuration, as well as data and products.


title: Equation of State in the Presence of Gravity

abstract:
  We investigate how an equation of state for matter is affected when a gravity
is present. For this purpose, we consider a box of ideal gas in the presence of
Newtonian gravity. In addition to the ordinary thermodynamic quantities, a
characteristic variable that represents a weight per unit area relative to the
average pressure is required in order to describe a macroscopic state of the
gas. Although the density and the pressure are not uniform due to the presence
of gravity, the ideal gas law itself is satisfied for the thermodynamic
quantities when averaged over the system. Assuming that the system follows an
adiabatic process further, we obtain a {\it new} relation between the averaged
pressure and density, which differs from the conventional equation of state for
the ideal gas in the absence of gravity. Applying our results to a small volume
in a Newtonian star, however, we find that the conventional one is reliable for
most astrophysical situations when the characteristic scale is small. On the
other hand, gravity effects become significant near the surface of a Newtonian
star.


title: Solving Visual Madlibs with Multiple Cues

abstract:
  This paper focuses on answering fill-in-the-blank style multiple choice
questions from the Visual Madlibs dataset. Previous approaches to Visual
Question Answering (VQA) have mainly used generic image features from networks
trained on the ImageNet dataset, despite the wide scope of questions. In
contrast, our approach employs features derived from networks trained for
specialized tasks of scene classification, person activity prediction, and
person and object attribute prediction. We also present a method for selecting
sub-regions of an image that are relevant for evaluating the appropriateness of
a putative answer. Visual features are computed both from the whole image and
from local regions, while sentences are mapped to a common space using a simple
normalized canonical correlation analysis (CCA) model. Our results show a
significant improvement over the previous state of the art, and indicate that
answering different question types benefits from examining a variety of image
cues and carefully choosing informative image sub-regions.


title: The AMBRE Project: Constraining the lithium evolution in the Milky Way

abstract:
  The chemical evolution of lithium in the Milky Way represents a major problem
in modern astrophysics. Indeed, lithium is, on the one hand, easily destroyed
in stellar interiors, and, on the other hand, produced at some specific stellar
evolutionary stages that are still not well constrained. The goal of this paper
is to investigate the lithium stellar content of Milky Way stars in order to
put constraints on the lithium chemical enrichment in our Galaxy, in particular
in both the thin and thick discs. Thanks to high-resolution spectra from the
ESO archive and high quality atmospheric parameters, we were able to build a
massive and homogeneous catalogue of lithium abundances for 7300 stars derived
with an automatic method coupling, a synthetic spectra grid, and a Gauss-Newton
algorithm. We validated these lithium abundances with literature values,
including those of the Gaia benchmark stars. In terms of lithium galactic
evolution, we show that the interstellar lithium abundance increases with
metallicity by 1 dex from [M/H]=-1 dex to +0.0 dex. Moreover, we find that this
lithium ISM abundance decreases by about 0.5 dex at super-solar metalllicity.
Based on a chemical separation, we also observed that the stellar lithium
content in the thick disc increases rather slightly with metallicity, while the
thin disc shows a steeper increase. The lithium abundance distribution of
alpha-rich, metal-rich stars has a peak at A(Li)~3 dex. We conclude that the
thick disc stars suffered of a low lithium chemical enrichment, showing lithium
abundances rather close to the Spite plateau while the thin disc stars clearly
show an increasing lithium chemical enrichment with the metallicity, probably
thanks to the contribution of low-mass stars.


title:
The space time DoF surface density as a phase-space of accelerating
  reference frames

abstract:
  Padmanabhan found a definition for the surface density of space time degrees
of freedom. We prove that this density can be constructed from a phase space
which is derived with respect to a special space like vector field. This vector
field is the direction of an accelerating vector field. After projecting this
phase space along a velocity vector field, we show that Padmanabhan's surface
density is actually the projected phase space during one period of the
Euclidean time which is expected for a canonical ensemble. This suggests that
Padmanabhan's density should be regarded as a spatial phase space which is
driven by acceleration.


title: Surreal numbers with derivation, Hardy fields and transseries: a survey

abstract:
  The present article surveys surreal numbers with an informal approach, from
their very first definition to their structure of universal real closed
analytic and exponential field. Then we proceed to give an overview of the
recent achievements on equipping them with a derivation, which is done by
proving that surreal numbers can be seen as transseries and by finding the
`simplest' structure of H-field, the abstract version of a Hardy field. All the
latter notions and their context are also addressed, as well as the
universality of the resulting structure for surreal numbers.


title:
Pointwise Multipliers for Sobolev and Besov Spaces of Dominating Mixed
  Smoothness

abstract:
  Under certain restrictions we describe the set of all pointwise multipliers
in case of Sobolev and Besov spaces of dominating mixed smoothness. In addition
we shall give necessary and sufficient conditions for the case that these
spaces form algebras with respect to pointwise multiplication.


title: ARMv8 Shellcodes from 'A' to 'Z'

abstract:
  We describe a methodology to automatically turn arbitrary ARMv8 programs into
alphanumeric executable polymorphic shellcodes. Shellcodes generated in this
way can evade detection and bypass filters, broadening the attack surface of
ARM-powered devices such as smartphones.


title: On fields of definition of components of the Siegel supersingular locus

abstract:
  Recently Ibukiyama proves an explicit formula for the number of certain
non-principal polarizations on a superspecial abelian surface, extending his
earlier work with Katsura for principal polarizations [Compos. Math. 1994]. As
a consequence of Ibukiyama's formula, there exists a geometrically irreducible
component of the Siegel supersingular locus which is defined over the prime
finite field. In this note we give a direct proof of this result.


title: Bird detection in audio: a survey and a challenge

abstract:
  Many biological monitoring projects rely on acoustic detection of birds.
Despite increasingly large datasets, this detection is often manual or
semi-automatic, requiring manual tuning/postprocessing. We review the state of
the art in automatic bird sound detection, and identify a widespread need for
tuning-free and species-agnostic approaches. We introduce new datasets and an
IEEE research challenge to address this need, to make possible the development
of fully automatic algorithms for bird sound detection.


title:
Analytical approach to high harmonics spectrum in the nanobunching
  regime

abstract:
  With the high-order harmonic generation (HHG) from plasma sur- faces it is
possible to turn a laser pulse into a train of attosecond or even zeptosecond
pulses in the backward radiation. These attosecond pulses may have amplitude
several orders of magnitude higher than that of the laser pulse under
appropriate conditions. We study this process in detail, especially the
nanobunching of the plasma electron density. We derive an analytical expression
that describes the electron density pro- file and obtain a good agreement with
particle-in-cell simulation results. We investigate the most efficient case of
HHG at moderate laser intensity (I = 2*10^20 W/cm^2 ) on the over-dense plasma
slab with an exponential profile pre-plasma. Subsequently we calculate the
spectra of a single at- tosecond pulse from the backward radiation using our
expression for the density shape in combination with the equation for the
spectrum of the nanobunch radiation.


title: The Value of the Kac Polynomial at One

abstract:
  We establish a formula for the value of the Kac polynomial at one in terms of
Kac polynomials, evaluated at one, of the universal (abelian) covering quiver
by applying torus localization methods to quiver varieties introduced by
Hausel--Letellier--Rodriguez-Villegas.


title: The GCT camera for the Cherenkov Telescope Array

abstract:
  The Gamma-ray Cherenkov Telescope (GCT) is proposed for the Small-Sized
Telescope component of the Cherenkov Telescope Array (CTA). GCT's dual-mirror
Schwarzschild-Couder (SC) optical system allows the use of a compact camera
with small form-factor photosensors. The GCT camera is ~0.4 m in diameter and
has 2048 pixels; each pixel has a ~0.2 degree angular size, resulting in a wide
field-of-view. The design of the GCT camera is high performance at low cost,
with the camera housing 32 front-end electronics modules providing full
waveform information for all of the camera's 2048 pixels. The first GCT camera
prototype, CHEC-M, was commissioned during 2015, culminating in the first
Cherenkov images recorded by a SC telescope and the first light of a CTA
prototype. In this contribution we give a detailed description of the GCT
camera and present preliminary results from CHEC-M's commissioning.


title: On a Constrained Fractional Stochastic Volatility Model

abstract:
  This paper deals with an extension of the so-called Black-Scholes model in
which the volatility is modeled by a linear combination of the components of
the solution of a differential equation driven by a fractional Brownian motion
of Hurst parameter greater than $1/4$. In order to ensure the positiveness of
the volatility, the coefficients of that equation satisfy a viability
condition. The absence of arbitrages, the completeness of the market and a
pricing formula are established.


title: Chebyshev centers that are not farthest points

abstract:
  In this paper we address the question whether in a given Banach space, a
Chebyshev center of a nonempty bounded subset can be a farthest point of the
set. Our exploration reveals that the answer depends on the convexity
properties of the Banach space. We obtain a characterization of two-dimensional
real strictly convex spaces in terms of Chebyshev center not contributing to
the set of farthest points. We explore the scenario in uniformly convex Banach
spaces and further study the roles played by centerability and M-compactness in
the scheme of things to obtain a step by step characterization of strictly
convex Banach spaces. We also illustrate with examples the optimality of our
results.


title: Regularity principle in sequence spaces and applications

abstract:
  We prove a nonlinear regularity principle in sequence spaces which produces
universal estimates for special series defined therein. Some consequences are
obtained and, in particular, we establish new inclusion theorems for multiple
summing operators. Of independent interest, we settle all Grothendieck's type
$(\ell_{1},\ell_{2})$ theorems for multilinear operators. We further employ the
new regularity principle to solve the classification problem concerning all
pairs of admissible exponents in the anisotropic Hardy--Littlewood inequality.


title: Partial Evaluation of Order-sorted Equational Programs modulo Axioms

abstract:
  Partial evaluation (PE) is a powerful and general program optimization
technique with many successful applications. However, it has never been
investigated in the context of expressive rule-based languages like Maude,
CafeOBJ, OBJ, ASF+SDF, and ELAN, which support: 1) rich type structures with
sorts, subsorts and overloading; 2) equational rewriting modulo axioms such as
commutativity, associativity-commutativity, and
associativity-commutativity-identity. In this extended abstract, we illustrate
the key concepts by showing how they apply to partial evaluation of expressive
rule-based programs written in Maude. Our partial evaluation scheme is based on
an automatic unfolding algorithm that computes term variants and relies on
equational least general generalization for ensuring global termination. We
demonstrate the use of the resulting partial evaluator for program optimization
on several examples where it shows significant speed-ups.


title:
Neural Encoding and Decoding with Deep Learning for Dynamic Natural
  Vision

abstract:
  Convolutional neural network (CNN) driven by image recognition has been shown
to be able to explain cortical responses to static pictures at ventral-stream
areas. Here, we further showed that such CNN could reliably predict and decode
functional magnetic resonance imaging data from humans watching natural movies,
despite its lack of any mechanism to account for temporal dynamics or feedback
processing. Using separate data, encoding and decoding models were developed
and evaluated for describing the bi-directional relationships be-tween the CNN
and the brain. Through the encoding models, the CNN-predicted areas covered not
only the ventral stream, but also the dorsal stream, albe-it to a lesser
degree; single-voxel response was visualized as the specific pixel pattern that
drove the response, revealing the distinct representation of individual
cortical location; cortical activation was synthesized from natural images with
high-throughput to map category representation, con-trast, and selectivity.
Through the decoding models, fMRI signals were directly decoded to estimate the
feature representations in both visual and semantic spaces, for direct visual
reconstruction and seman-tic categorization, respectively. These results
cor-roborate, generalize, and extend previous findings, and highlight the value
of using deep learning, as an all-in-one model of the visual cortex, to
understand and decode natural vision.


title:
Inverse magnetocaloric effect in the spin-1/2 Fisher's super-exchange
  antiferromagnet

abstract:
  The isothermal entropy change and the adiabatic temperature change for the
exactly solved spin-1/2 Fisher's super-exchange antiferromagnet are rigorously
calculated in order to examine magnetocaloric properties of the model in a
vicinity of the second-order phase transition. It is shown that the large
inverse magnetocaloric effect occurs around the temperature interval
$T_c(h\neq0) < T < T_c(h=0)$ for any magnetic-field change $\Delta h: 0 \to h$.
The most pronounced inverse magnetocaloric effect can be found for the
magnetic-field change, which coincides with the critical field of a
zero-temperature phase transition from the antiferromagnetically ordered ground
state to the paramagnetic one.


title:
Electrically charged matter in permanent rotation around magnetized
  black hole: A toy model for self-gravitating fluid tori

abstract:
  We present an analytical approach for the equilibrium of a self-gravitating
charged fluid embedded in a spherical gravitational and dipolar magnetic fields
produced by a central mass. Our scheme is proposed, as a toy-model, in the
context of gaseous/dusty tori surrounding supermassive black holes in galactic
nuclei. While the central black hole dominates the gravitational field and it
remains electrically neutral, the surrounding material has a non-negligible
self-gravitational effect on the torus structure. By charging mechanisms it
also acquires non-zero electric charge density, so the two influences need to
be taken into account to achieve a self-consistent picture. With our approach
we discuss the impact of self-gravity, represented by the term dt (ratio of the
torus total mass to the mass of the central body), on the conditions for
existence of the equilibrium and the morphology and typology of the tori. By
comparison with a previous work without self-gravity, we show that the
conditions can be different. Although the main aim of the present paper is to
discuss a framework for the classification of electrically charged, magnetized,
self-gravitating tori, we also mention potential astrophysical applications to
vertically stratified fluid configurations.


title:
A Gaussian Markov alternative to fractional Brownian motion for pricing
  financial derivatives

abstract:
  Replacing Black-Scholes' driving process, Brownian motion, with fractional
Brownian motion allows for incorporation of a past dependency of stock prices
but faces a few major downfalls, including the occurrence of arbitrage when
implemented in the financial market. We present the development, testing, and
implementation of a simplified alternative to using fractional Brownian motion
for pricing derivatives. By relaxing the assumption of past independence of
Brownian motion but retaining the Markovian property, we are developing a
competing model that retains the mathematical simplicity of the standard
Black-Scholes model but also has the improved accuracy of allowing for past
dependence. This is achieved by replacing Black-Scholes' underlying process,
Brownian motion, with a particular Gaussian Markov process, proposed by
Vladimir Dobri\'{c} and Francisco Ojeda.


title:
Information-Centric Offloading in Cellular Networks with Coordinated
  Device-to-Device Communication

abstract:
  In this paper, we develop a comprehensive analytical framework for cache
enabled cellular networks overlaid with coordinated device-to-device (D2D)
communication. We follow an approach similar to LTE Direct, where the base
station (BS) is responsible for establishing D2D links. We consider that an
arbitrary requesting user is offloaded to D2D mode to communicate with one of
its 'k' closest D2D helpers within the macrocell subject to content
availability and helper selection scheme. We consider two different D2D helper
selection schemes: 1) uniform selection (US), where the D2D helper is selected
uniformly and 2) nearest selection (NS), where the nearest helper possessing
the content is selected. Employing tools from stochastic geometry, we model the
locations of BSs and D2D helpers using independent homogeneous Poisson point
processes (HPPPs). We characterize the D2D mode probability of an arbitrary
user for both the NS and US schemes. The distribution of the distance between
an arbitrary user and its ith neighboring D2D helper within the macrocell is
derived using disk approximation for the Voronoi cell, which is shown to be
reasonably accurate. We fully characterize the overall coverage probability and
the average ergodic rate of an arbitrary user requesting a particular content.
We show that significant performance gains can be achieved compared to
conventional cellular communication under both the NS and US schemes when
popular contents are requested and NS scheme always outperforms the US scheme.
Our analysis reveals an interesting trade off between the performance metrics
and the number of candidate D2D helpers 'k'. We conclude that enhancing D2D
opportunities for the users does not always result in better performance and
the network parameters have to be carefully tuned to harness maximum gains.


title: FreeSense:Indoor Human Identification with WiFi Signals

abstract:
  Human identification plays an important role in human-computer interaction.
There have been numerous methods proposed for human identification (e.g., face
recognition, gait recognition, fingerprint identification, etc.). While these
methods could be very useful under different conditions, they also suffer from
certain shortcomings (e.g., user privacy, sensing coverage range). In this
paper, we propose a novel approach for human identification, which leverages
WIFI signals to enable non-intrusive human identification in domestic
environments. It is based on the observation that each person has specific
influence patterns to the surrounding WIFI signal while moving indoors,
regarding their body shape characteristics and motion patterns. The influence
can be captured by the Channel State Information (CSI) time series of WIFI.
Specifically, a combination of Principal Component Analysis (PCA), Discrete
Wavelet Transform (DWT) and Dynamic Time Warping (DTW) techniques is used for
CSI waveform-based human identification. We implemented the system in a 6m*5m
smart home environment and recruited 9 users for data collection and
evaluation. Experimental results indicate that the identification accuracy is
about 88.9% to 94.5% when the candidate user set changes from 6 to 2, showing
that the proposed human identification method is effective in domestic
environments.


title:
DiskFiltration: Data Exfiltration from Speakerless Air-Gapped Computers
  via Covert Hard Drive Noise

abstract:
  Air-gapped computers are disconnected from the Internet physically and
logically. This measure is taken in order to prevent the leakage of sensitive
data from secured networks. In the past, it has been shown that malware can
exfiltrate data from air-gapped computers by transmitting ultrasonic signals
via the computer's speakers. However, such acoustic communication relies on the
availability of speakers on a computer. In this paper, we present
'DiskFiltration,' a covert channel which facilitates the leakage of data from
an air-gapped compute via acoustic signals emitted from its hard disk drive
(HDD). Our method is unique in that, unlike other acoustic covert channels, it
doesn't require the presence of speakers or audio hardware in the air-gapped
computer. A malware installed on a compromised machine can generate acoustic
emissions at specific audio frequencies by controlling the movements of the
HDD's actuator arm. Digital Information can be modulated over the acoustic
signals and then be picked up by a nearby receiver (e.g., smartphone,
smartwatch, laptop, etc.). We examine the HDD anatomy and analyze its
acoustical characteristics. We also present signal generation and detection,
and data modulation and demodulation algorithms. Based on our proposed method,
we developed a transmitter on a personal computer and a receiver on a
smartphone, and we provide the design and implementation details. We also
evaluate our covert channel on various types of internal and external HDDs in
different computer chassis and at various distances. With DiskFiltration we
were able to covertly transmit data (e.g., passwords, encryption keys, and
keylogging data) between air-gapped computers to a smartphone at an effective
bit rate of 180 bits/minute (10,800 bits/hour) and a distance of up to two
meters (six feet).


title: Phenomenological plasmon broadening and relation to the dispersion

abstract:
  Pragmatic ways of including lifetime broadening of collective modes in the
electron liquid are critically compared. Special focus lies on the impact of
the damping parameter onto the dispersion. It is quantitatively exemplified for
the two-dimensional case, for both, the charge (`sheet'-)plasmon and the
spin-density plasmon. The predicted deviations fall within the resolution
limits of advanced techniques.


title: Evidence for a Strong Topological Insulator Phase in $\mathrm{ZrTe_5}$

abstract:
  The complex electronic properties of $\mathrm{ZrTe_5}$ have recently
stimulated in-depth investigations that assigned this material to either a
topological insulator or a 3D Dirac semimetal phase. Here we report a
comprehensive experimental and theoretical study of both electronic and
structural properties of $\mathrm{ZrTe_5}$, revealing that the bulk material is
a strong topological insulator (STI). By means of angle-resolved photoelectron
spectroscopy, we identify at the top of the valence band both a surface and a
bulk state. The dispersion of these bands is well captured by ab initio
calculations for the STI case, for the specific interlayer distance measured in
our x-ray diffraction study. Furthermore, these findings are supported by
scanning tunneling spectroscopy revealing the metallic character of the sample
surface, thus confirming the strong topological nature of $\mathrm{ZrTe_5}$.


title:
Second-harmonic imaging microscopy for time-resolved investigations of
  transition metal dichalcogenides

abstract:
  Two-dimensional transition metal dichalcogenides (TMDC) have shown promise
for various applications in optoelectronics and so-called valleytronics. Their
operation and performance strongly depend on the stacking of individual layers.
Here, optical second-harmonic generation (SHG) in imaging mode is shown to be a
versatile tool for systematic time-resolved investigations of TMDC monolayers
and heterostructures in consideration of the material's structure. Large sample
areas can be probed without the need of any mapping or scanning. By means of
polarization dependent measurements, the crystalline orientation of monolayers
or the stacking angles of heterostructures can be evaluated for the whole field
of view. Pump-probe experiments then allow to correlate observed transient
changes of the second-harmonic response with the underlying structure. The
corresponding time-resolution is virtually limited by the pulse duration of the
used laser. As an example, polarization dependent and time-resolved
measurements on mono- and multilayer MoS$_2$ flakes grown on a SiO$_2$/Si(001)
substrate are presented.


title: Volume difference inequalities

abstract:
  We prove several inequalities estimating the distance between volumes of two
bodies in terms of the maximal or minimal difference between areas of sections
or projections of these bodies. We also provide extensions in which volume is
replaced by an arbitrary measure.


title:
Nuclear dynamical correlation effects in X-ray spectroscopy from a
  time-domain perspective

abstract:
  To date X-ray spectroscopy has become a routine tool that can reveal highly
local and element-specific information on the electronic structure of atoms in
complex environments. Here, we focus on nuclear dynamical effects in X-ray
spectra and develop a rigorous time-correlation method employing ground state
molecular dynamics simulations. The importance of nuclear correlation phenomena
is demonstrated by comparison against the results from the conventional
sampling approach for gas phase water. In contrast to the first-order
absorption, second-order resonant inelastic scattering spectra exhibit
pronounced fingerprints of nuclear motions. The developed methodology does not
depend on the accompanying electronic structure method in principle as well as
on the spectral range and, thus, can be applied to, e.g., UV and X-ray
photo-electron and Auger spectroscopies.


title: Coherent spaces, Boolean rings and quantum gates

abstract:
  Coherent spaces spanned by a finite number of coherent states, are
introduced. Their coherence properties are studied, using the Dirac contour
representation. It is shown that the corresponding projectors resolve the
identity, and that they transform into projectors of the same type, under
displacement transformations, and also under time evolution. The set of these
spaces, with the logical OR and AND operations is a distributive lattice, and
with the logical XOR and AND operations is a Boolean ring (Stone\rq{}s
formalism). Applications of this Boolean ring into classical CNOT gates with
$n$-ary variables, and also quantum CNOT gates with coherent states, are
discussed.


title: Exact propagation of open quantum systems in a system-reservoir context

abstract:
  A stochastic representation of the dynamics of open quantum systems, suitable
for non-perturbative system-reservoir interaction, non-Markovian effects and
arbitrarily driven systems is presented. It includes the case of driving on
timescales comparable to or shorter than the reservoir correlation time, a
notoriously difficult but relevant case in the context of quantum information
processing and quantum thermodynamics. A previous stochastic approach is
re-formulated for the case of finite reservoir correlation and response times,
resulting in a numerical simulation strategy exceeding previous ones by orders
of magnitude in efficiency. Although the approach is based on a memory
formalism, the dynamical equations propagated in the simulations are
time-local. This leaves a wide range of choices in selecting the system to be
studied and the numerical method used for propagation. For a series of tests,
the dynamics of the spin-boson system is computed in various settings including
strong external driving and Landau-Zener transitions.


title: Finding Large Set Covers Faster via the Representation Method

abstract:
  The worst-case fastest known algorithm for the Set Cover problem on universes
with $n$ elements still essentially is the simple $O^*(2^n)$-time dynamic
programming algorithm, and no non-trivial consequences of an $O^*(1.01^n)$-time
algorithm are known. Motivated by this chasm, we study the following natural
question: Which instances of Set Cover can we solve faster than the simple
dynamic programming algorithm? Specifically, we give a Monte Carlo algorithm
that determines the existence of a set cover of size $\sigma n$ in
$O^*(2^{(1-\Omega(\sigma^4))n})$ time. Our approach is also applicable to Set
Cover instances with exponentially many sets: By reducing the task of finding
the chromatic number $\chi(G)$ of a given $n$-vertex graph $G$ to Set Cover in
the natural way, we show there is an $O^*(2^{(1-\Omega(\sigma^4))n})$-time
randomized algorithm that given integer $s=\sigma n$, outputs NO if $\chi(G) >
s$ and YES with constant probability if $\chi(G)\leq s-1$.
  On a high level, our results are inspired by the `representation method' of
Howgrave-Graham and Joux~[EUROCRYPT'10] and obtained by only evaluating a
randomly sampled subset of the table entries of a dynamic programming
algorithm.


title: Recurrent Neural Networks to Correct Satellite Image Classification Maps

abstract:
  While initially devised for image categorization, convolutional neural
networks (CNNs) are being increasingly used for the pixelwise semantic labeling
of images. However, the proper nature of the most common CNN architectures
makes them good at recognizing but poor at localizing objects precisely. This
problem is magnified in the context of aerial and satellite image labeling,
where a spatially fine object outlining is of paramount importance. Different
iterative enhancement algorithms have been presented in the literature to
progressively improve the coarse CNN outputs, seeking to sharpen object
boundaries around real image edges. However, one must carefully design, choose
and tune such algorithms. Instead, our goal is to directly learn the iterative
process itself. For this, we formulate a generic iterative enhancement process
inspired from partial differential equations, and observe that it can be
expressed as a recurrent neural network (RNN). Consequently, we train such a
network from manually labeled data for our enhancement task. In a series of
experiments we show that our RNN effectively learns an iterative process that
significantly improves the quality of satellite image classification maps.


title: Tidal origin of spiral arms in galaxies orbiting a cluster

abstract:
  One of the scenarios for the formation of grand-design spiral arms in disky
galaxies involves their interactions with a satellite or another galaxy. Here
we consider another possibility, where the perturbation is instead due to the
potential of a galaxy cluster. Using $N$-body simulations we investigate the
formation and evolution of spiral arms in a Milky Way-like galaxy orbiting a
Virgo-like cluster. The galaxy is placed on a few orbits of different size but
similar eccentricity and its evolution is followed for 10 Gyr. The tidally
induced, two-armed, approximately logarithmic spiral structure forms on each of
them during the pericenter passages. The spiral arms dissipate and wind up with
time, to be triggered again at the next pericenter passage. We confirm this
transient and recurrent nature of the arms by analyzing the time evolution of
the pitch angle and the arm strength. We find that the strongest arms are
formed on the tightest orbit, however they wind up rather quickly and are
disturbed by another pericenter passage. The arms on the most extended orbit,
which we analyze in more detail, wind up slowly and survive for the longest
time. Measurements of the pattern speed of the arms indicate that they are
kinematic density waves. We attempt a comparison with observations by selecting
grand-design spiral galaxies in the Virgo cluster. Among those, we find nine
examples bearing no signs of recent interactions or the presence of companions.
For three of them we present close structural analogues among our simulated
spiral galaxies.


title: Analytic continuation of equivariant distributions

abstract:
  We establish a method for constructing equivariant distributions on smooth
real algebraic varieties from equivariant distributions on Zariski open
subsets. This is based on Bernstein's theory of analytic continuation of
holonomic distributions. We use this to construct $H$-equivariant functionals
on principal series representations of $G$, where $G$ is a real reductive group
and $H$ is an algebraic subgroup. We also deduce the existence of generalized
Whittaker models for degenerate principal series representations. As a special
case, this gives short proofs of existence of Whittaker models on principal
series representations, and of analytic continuation of standard intertwining
operators. Finally, we extend our constructions to the $p$-adic case using a
recent result of Hong and Sun.


title:
Optical vortices discern attosecond time delay in electron emission from
  magnetic sublevels

abstract:
  Photoionization from energetically distinct electronic states may have a
relative time delay of tens of attoseconds. Here we demonstrate that pulses of
optical vortices allow measuring such attoseconds delays from magnetic
sublevels, even from a spherically symmetric target. The difference in the time
delay is substantial and exhibits a strong angular dependence. Furthermore, we
find an atomic scale variation in the time delays depending on the target
orbital position in the laser spot. The findings offer thus a qualitatively new
way for a spatio-temporal sensing of the magnetic states from which the
photoelectrons originate, with a spatial resolution way below the diffraction
limit of the vortex beam. Our conclusions follow from analytical considerations
based on symmetry, complemented and confirmed with full numerical simulations
of the quantum dynamics.


title:
Dynamical freeze-out criterion in a hydrodynamical description of Au +
  Au collisions at $\sqrt{s_\mathrm{NN}}=200$ GeV and Pb + Pb collisions at
  $\sqrt{s_\mathrm{NN}}=2760$ GeV

abstract:
  In hydrodynamical modeling of ultrarelativistic heavy-ion collisions, the
freeze-out is typically assumed to take place at a surface of constant
temperature or energy density. A more physical approach is to assume that
freeze-out takes place at a surface of constant Knudsen number. We evaluate the
Knudsen number as a ratio of the expansion rate of the system to the pion
scattering rate, and apply the constant Knudsen number freeze-out criterion to
ideal hydrodynamical description of heavy-ion collisions at RHIC
($\sqrt{s_\mathrm{NN}}=200$ GeV) and the LHC ($\sqrt{s_\mathrm{NN}}=2760$ GeV)
energies. We see that once the numerical values of freeze-out temperature and
freeze-out Knudsen number are chosen to produce similar $p_T$ distributions,
the elliptic and triangular anisotropies are similar too, in both
event-by-event and averaged initial state calculations.


title:
Given Enough Eyeballs, All Bugs Are Shallow? Revisiting Eric Raymond
  with Bug Bounty Programs

abstract:
  Bug bounty programs offer a modern platform for organizations to crowdsource
their software security and for security researchers to be fairly rewarded for
the vulnerabilities they find. Little is known however on the incentives set by
bug bounty programs: How they drive new bug discoveries, and how they
supposedly improve security through the progressive exhaustion of discoverable
vulnerabilities. Here, we recognize that bug bounty programs create tensions,
for organizations running them on the one hand, and for security researchers on
the other hand. At the level of one bug bounty program, security researchers
face a sort of St-Petersburg paradox: The probability of finding additional
bugs decays fast, and thus can hardly be matched with a sufficient increase of
monetary rewards. Furthermore, bug bounty program managers have an incentive to
gather the largest possible crowd to ensure a larger pool of expertise, which
in turn increases competition among security researchers. As a result, we find
that researchers have high incentives to switch to newly launched programs, for
which a reserve of low-hanging fruit vulnerabilities is still available. Our
results inform on the technical and economic mechanisms underlying the dynamics
of bug bounty program contributions, and may in turn help improve the mechanism
design of bug bounty programs that get increasingly adopted by cybersecurity
savvy organizations.


title: Maximum antichains in posets of quiver representations

abstract:
  We study maximum antichains in two posets related to quiver representations.
Firstly, we consider the set of isomorphism classes of indecomposable
representations ordered by inclusion. For various orientations of the Dynkin
diagram of type A we construct a maximum antichain in the poset. Secondly, we
consider the set of subrepresentations of a given quiver representation, again
ordered by inclusion. It is a finite set if we restrict to linear
representations over finite fields or to representations with values in the
category of pointed sets. For particular situations we prove that this poset is
Sperner.


title:
Decay of geodesic acoustic modes due to the combined action of phase
  mixing and Landau damping

abstract:
  Geodesic acoustic modes (GAMs) are oscillations of the electric field whose
importance in tokamak plasmas is due to their role in the regulation of
turbulence. The linear collisionless damping of GAMs is investigated here by
means of analytical theory and numerical simulations with the global
gyrokinetic particle-in-cell code ORB5. The combined effect of the phase mixing
and Landau damping is found to quickly redistribute the GAM energy in
phase-space, due to the synergy of the finite orbit width of the passing ions
and the cascade in wave number given by the phase mixing. When plasma
parameters characteristic of realistic tokamak profiles are considered, the GAM
decay time is found to be an order of magnitude lower than the decay due to the
Landau damping alone, and in some cases of the same order of magnitude of the
characteristic GAM drive time due to the nonlinear interaction with an ITG
mode. In particular, the radial mode structure evolution in time is
investigated here and reproduced quantitatively by means of a dedicated initial
value code and diagnostics.


title: Sex, drugs, and violence

abstract:
  Automatically detecting inappropriate content can be a difficult NLP task,
requiring understanding context and innuendo, not just identifying specific
keywords. Due to the large quantity of online user-generated content, automatic
detection is becoming increasingly necessary. We take a largely unsupervised
approach using a large corpus of narratives from a community-based
self-publishing website and a small segment of crowd-sourced annotations. We
explore topic modelling using latent Dirichlet allocation (and a variation),
and use these to regress appropriateness ratings, effectively automating rating
for suitability. The results suggest that certain topics inferred may be useful
in detecting latent inappropriateness -- yielding recall up to 96% and low
regression errors.


title:
The effect of reactions on the formation and readout of the gradient of
  Bicoid

abstract:
  During early development, the establishment of gradients of transcriptional
factors determines the patterning of cell fates. The case of Bicoid (Bcd) in
{\it Drosophila melanogaster} embryos is well documented and studied. There are
still controversies as to whether {\it SDD} models in which Bcd is {\it
Synthesized} at one end, then {\it Diffuses} and is {\it Degraded} can explain
the gradient formation within the timescale observed experimentally. The Bcd
gradient is observed in embryos that express a Bicoid-eGFP fusion protein
(Bcd-GFP) which cannot differentiate if Bcd is freely diffusing or bound to
immobile sites. In this work we analyze an {\it SDID} model that includes the
{\it Interaction} of Bcd with binding sites. Using previously determined
biophysical parameters we find that this model can explain the gradient
formation within the experimentally observed time. Analyzing the differences
between the free and bound Bcd distributions we observe that the latter spans
over a longer lengthscale. We conclude that deriving the lengthscale from the
distribution of Bcd-GFP can lead to an overestimation of the gradient
lengthscale and of the degree of cooperativity that explains the distribution
of the protein Hunchback whose production is regulated by Bcd.


title: Geometric-Algebra Adaptive Filters

abstract:
  This paper presents a new class of adaptive filters, namely Geometric-Algebra
Adaptive Filters (GAAFs). They are generated by formulating the underlying
minimization problem (a deterministic cost function) from the perspective of
Geometric Algebra (GA), a comprehensive mathematical language well-suited for
the description of geometric transformations. Also, differently from standard
adaptive-filtering theory, Geometric Calculus (the extension of GA to
differential calculus) allows for applying the same derivation techniques
regardless of the type (subalgebra) of the data, i.e., real, complex numbers,
quaternions, etc. Relying on those characteristics (among others), a
deterministic quadratic cost function is posed, from which the GAAFs are
devised, providing a generalization of regular adaptive filters to subalgebras
of GA. From the obtained update rule, it is shown how to recover the following
least-mean squares (LMS) adaptive filter variants: real-entries LMS, complex
LMS, and quaternions LMS. Mean-square analysis and simulations in a system
identification scenario are provided, showing very good agreement for different
levels of measurement noise.


title:
Lebesgue constants for polyhedral sets and polynomial interpolation on
  Lissajous-Chebyshev nodes

abstract:
  To analyze the absolute condition number of multivariate polynomial
interpolation on Lissajous-Chebyshev node points, we derive upper and lower
bounds for the respective Lebesgue constant. The proof is based on a relation
between the Lebesgue constant for the polynomial interpolation problem and the
Lebesgue constant linked to the polyhedral partial sums of Fourier series. The
magnitude of the obtained bounds is determined by a product of logarithms of
the side lengths of the considered polyhedral sets and shows the same behavior
as the magnitude of the Lebesgue constant for polynomial interpolation on the
tensor product Chebyshev grid.


title:
Lower semicontinuity of solution mappings for parametric fixed point
  problems with applications

abstract:
  In this paper, we establish the lower semicontinuity of the solution mapping
and of the approximate solution mapping for parametric fixed point problems
under some suitable conditions. As applications, the lower semicontinuity
result applies to the parametric vector quasi-equilibrium problem, and allows
to prove the existence of solutions for generalized Stackelberg games.


title: Muon Beam at the Fermilab Test Beam Area

abstract:
  The intensities and profiles of the muon beam behind the beam dump of the
Fermilab test beam area when the facility is running in the "pion" beam mode
are measured and summarized in this note. This muon beam with momenta in the
range 10 - 50 GeV/c provides an opportunity to perform various measurements in
parallel with other users of the test beam area.


title:
Proceedings of the 2014 Joint International Accelerator School: Beam
  Loss and Accelerator Protection (JAS 2014), Newport Beach, CA, USA, 5-14 Nov
  2014

abstract:
  Many particle accelerators operate with very high beam power and very high
energy stored in particle beams as well as in magnet systems. In the future,
the beam power in high intensity accelerators will further increase. The
protection of the accelerator equipment from the consequences of uncontrolled
release of the energy is essential. This was the motivation for organizing a
first school on beam losses and accelerator protection (in general referred to
as machine protection). During the school the methods and technologies to
identify, mitigate, monitor and manage the technical risks associated with the
operation of accelerators with high-power beams or subsystems with large stored
energy were presented. At the completion of the school the participants should
have been able to understand the physical phenomena that can damage machine
subsystems or interrupt operations and to analyze an accelerator facility to
produce a register of technical risks and the corresponding risk mitigation and
management strategies.


title:
Does the chemical signature of TYC 8442-1036-1 originate from a rotating
  massive star that died in a faint explosion?

abstract:
  Context. We have recently investigated the origin of chemical signatures
observed in Galactic halo stars by means of a stochastic chemical evolution
model. We have found that rotating massive stars are a promising way to explain
several signatures observed in these fossil stars. Aims. In the present paper
we discuss how the extremely metal-poor halo star TYC 8442-1036-1, for which we
have now obtained detailed abundances from VLT-UVES spectra, fits into the
framework of our previous work. Methods. We apply a standard 1D LTE analysis to
the spectrum of this star. We measure the abundances of 14 chemical elements;
for Na, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni and Zn we compute the abundances
using equivalent widths; for C, Sr and Ba we obtain the abundances by means of
synthetic spectra generated by MOOG. Results. We find an abundance of [Fe/H]=
$-$3.5 $\pm$0.13 dex based on our high resolution spectrum; this points to an
iron content lower by a factor of three (0.5 dex) compared to the one obtained
by a low resolution spectrum. The star has a [C/Fe] = 0.4 dex, and it is not
carbon enhanced like most of the stars at this metallicity. Moreover, this star
lies in the plane [Ba/Fe] vs. [Fe/H] in a relatively unusual position, shared
by a few others galactic halo stars that is only marginally explained by our
past results. Conclusions. The comparison of the model results with the
chemical abundance characteristics of this group of stars can be improved if we
consider in our model the presence of faint supernovae coupled with rotating
massive stars. These results seem to imply that rotating massive stars and
faint supernovae scenarios are complementary to each other, and are both
required in order to match the observed chemistry of the earliest phases of the
chemical enrichment of the Universe.


title:
Entanglement generation through particle detection in systems of
  identical fermions

abstract:
  We investigate the generation of entanglement in systems of identical
fermions through a process involving particle detection, focusing on the
implications that this kind of processes have for the concept of entanglement
between fermionic particles. As a paradigmatic example we discuss in detail a
scheme based on a splitting-plus-detection operation. This scheme generates
states with accessible entanglement starting from an initial pure state of two
indistinguishable fermions exhibiting correlations due purely to
antisymmetrization. It is argued that the proposed extraction of entanglement
does not contravene the notion that entanglement in identical-fermion systems
requires correlations beyond those purely due to their indistinguishability. In
point of fact, it is shown that this concept of entanglement, here referred to
as {\it fermonic entanglement}, actually helps to clarify some essential
aspects of the entanglement generation process. In particular, we prove that
the amount of extracted accessible entanglement equals the amount of fermionic
entanglement created with the detection process. The aforementioned scheme is
generalized for the case of $N$-identical fermion systems of arbitrary
dimension. It transpires from our present discussion that a proper analysis of
entanglement generation during the splitting-plus-detection operation is not
only consistent with the concept of fermonic entanglement, but actually
reinforces this concept.


title: Orbital Picture of Yu-Shiba-Rusinov Multiplets

abstract:
  We investigate the nature of Yu-Shiba-Rusinov (YSR) subgap states induced by
single Manganese (Mn) atoms adsorbed on different surface orientations of
superconducting lead (Pb). Depending on the adsorption site, we detect a
distinct number and characteristic patterns of YSR states around the Mn atoms.
We suggest that the YSR states inherit their properties from the Mn $d$-levels,
which are split by the surrounding crystal field. The periodicity of the
long-range YSR oscillations allows us to identify a dominant coupling of the
d-states to the outer Fermi sheet of the two-band superconductor Pb.


title:
Mixing of photons with light pseudoscalars in time-dependent magnetic
  fields

abstract:
  The effects of an external time-dependent magnetic field in the conversion
probability of photon-to-axion-like particles are studied. Our findings show
that for a certain time regime, the amplitude of the produced axion-like field
can be enlarged with respect to the static case, thus, enhancing the
probability of conversion.


title:
Estimating of the number of integer (natural) solutions of inhomogeneous
  algebraic Diophantine diagonal equations with integer coefficients

abstract:
  This paper investigates the upper bound of the number of integer (natural)
solutions of inhomogeneous algebraic Diophantine diagonal equations with
integer coefficients without a free member via the circle method of Hardy and
Littlewood. Author found the upper bound of the number of natural solutions of
inhomogeneous algebraic Diophantine diagonal equations with explicit variable.
He developed a method in the paper, which allows you to perform the low
estimate of the number of natural (integer) solutions of algebraic Diophantine
equation with integer coefficients. Author obtained a lower estimate (with this
method) of the number of integer (natural) solutions for certain kinds of
inhomogeneous algebraic Diophantine diagonal equations with integer
coefficients with any number of variables (including Thue equation).


title:
Analysis of the strong coupling form factors of $\Sigma_bNB$ and
  $\Sigma_c ND$ in QCD sum rules

abstract:
  In this article, we study the strong interaction of the vertexes $\Sigma_bNB$
and $\Sigma_c ND$ using the three-point QCD sum rules under two different dirac
structures. Considering the contributions of the vacuum condensates up to
dimension $5$ in the operation product expansion, the form factors of these
vertexes are calculated. Then, we fit the form factors into analytical
functions and extrapolate them into time-like regions, which giving the
coupling constant. Our analysis indicates that the coupling constant for these
two vertexes are $G_{\Sigma_bNB}=0.43\pm0.01GeV^{-1}$ and
$G_{\Sigma_cND}=3.76\pm0.05GeV^{-1}$.


title: Black-boxing and cause-effect power

abstract:
  Reductionism assumes that causation in the physical world occurs at the micro
level, excluding the emergence of macro-level causation. We challenge this
reductionist assumption by employing a principled, well-defined measure of
intrinsic cause-effect power - integrated information ({\Phi}), and showing
that, according to this measure, it is possible for a macro level to "beat" the
micro level. Simple systems were evaluated for {\Phi} across different spatial
and temporal scales by systematically considering all possible black boxes.
These are macro elements that consist of one or more micro elements over one or
more micro updates. Cause-effect power was evaluated based on the inputs and
outputs of the black boxes, ignoring the internal micro elements that support
their input-output function. We show how black-box elements can have more
common inputs and outputs than the corresponding micro elements, revealing the
emergence of high-order mechanisms and joint constraints that are not apparent
at the micro level. As a consequence, a macro, black-box system can have higher
{\Phi} than its micro constituents by having more mechanisms (higher
composition) that are more interconnected (higher integration). We also show
that, for a given micro system, one can identify local maxima of {\Phi} across
several spatiotemporal scales. The framework is demonstrated on a simple
biological system, the Boolean network model of the fission-yeast cell-cycle,
for which we identify stable local maxima during the course of its simulated
biological function. These local maxima correspond to macro levels of
organization at which emergent cause-effect properties of physical systems come
into focus, and provide a natural vantage point for scientific inquiries.


title: Multi-View Product Image Search Using Deep ConvNets Representations

abstract:
  Multi-view product image queries can improve retrieval performance over
single view queries significantly. In this paper, we investigated the
performance of deep convolutional neural networks (ConvNets) on multi-view
product image search. First, we trained a VGG-like network to learn deep
ConvNets representations of product images. Then, we computed the deep ConvNets
representations of database and query images and performed single view queries,
and multi-view queries using several early and late fusion approaches.
  We performed extensive experiments on the publicly available Multi-View
Object Image Dataset (MVOD 5K) with both clean background queries from the
Internet and cluttered background queries from a mobile phone. We compared the
performance of ConvNets to the classical bag-of-visual-words (BoWs). We
concluded that (1) multi-view queries with deep ConvNets representations
perform significantly better than single view queries, (2) ConvNets perform
much better than BoWs and have room for further improvement, (3) pre-training
of ConvNets on a different image dataset with background clutter is needed to
obtain good performance on cluttered product image queries obtained with a
mobile phone.


title:
Clique Topology Reveals Intrinsic Geometric Structure in Neural
  Correlations: An Overview

abstract:
  This publication serves as an overview of clique topology -- a novel matrix
analysis technique used to extract structural features from neural activity
data that contains hidden nonlinearities. We highlight work done by Gusti et
al. which introduces clique topology and verifies its applicability to neural
feature extraction by showing that neural correlations in the rat hippocampus
are determined by geometric structure of hippocampal circuits, rather than
being a consequence of positional coding.


title:
A New Statistical Model of Electroencephalogram Noise Spectra for
  Real-time Brain-Computer Interfaces

abstract:
  $Objective$: A characteristic of neurological signal processing is high
levels of noise from sub-cellular ion channels up to whole-brain processes. In
this paper, we propose a new model of electroencephalogram (EEG) background
periodograms, based on a family of functions which we call generalized van der
Ziel--McWhorter (GVZM) power spectral densities (PSDs). To the best of our
knowledge, the GVZM PSD function is the only EEG noise model which has
relatively few parameters, matches recorded EEG PSD's with high accuracy from 0
Hz to over 30 Hz, and has approximately $1/f^\theta$ behavior in the
mid-frequencies without infinities. $Methods$: We validate this model using
three approaches. First, we show how GVZM PSDs can arise in population of ion
channels in maximum entropy equilibrium. Second, we present a class of mixed
autoregressive models, which simulate brain background noise and whose
periodograms are asymptotic to the GVZM PSD. Third, we present two real-time
estimation algorithms for steady-state visual evoked potential (SSVEP)
frequencies, and analyze their performance statistically. $Results$: In
pairwise comparisons, the GVZM-based algorithms showed statistically
significant accuracy improvement over two well-known and widely-used SSVEP
estimators. $Conclusion$: The GVZM noise model can be a useful and reliable
technique for EEG signal processing. $Significance$: Understanding EEG noise is
essential for EEG-based neurology and applications such as real-time
brain-computer interfaces (BCIs), which must make accurate control decisions
from very short data epochs. The GVZM approach represents a successful new
paradigm for understanding and managing this neurological noise.


title: The Future of Data Analysis in the Neurosciences

abstract:
  Neuroscience is undergoing faster changes than ever before. Over 100 years
our field qualitatively described and invasively manipulated single or few
organisms to gain anatomical, physiological, and pharmacological insights. In
the last 10 years neuroscience spawned quantitative big-sample datasets on
microanatomy, synaptic connections, optogenetic brain-behavior assays, and
high-level cognition. While growing data availability and information
granularity have been amply discussed, we direct attention to a routinely
neglected question: How will the unprecedented data richness shape data
analysis practices? Statistical reasoning is becoming more central to distill
neurobiological knowledge from healthy and pathological brain recordings. We
believe that large-scale data analysis will use more models that are
non-parametric, generative, mixing frequentist and Bayesian aspects, and
grounded in different statistical inferences.


title: Phenomenology of additional scalar bosons at the LHC

abstract:
  The confirmation of the Higgs boson in Run I data at the Large Hadron
Collider (LHC) and the excesses in recent Run II data suggest scenarios beyond
the Standard Model (SM). We pursue a study in a minimal model which is an
extension of a scalar doublet in the SM known as two-Higgs doublet model
(THDM). Following earlier suggestions two real scalars $\chi$ and $S$ have been
introduced in the THDM where $\chi$ is treated as a candidate for dark matter.
$\chi$ does not receive any vacuum expectation value ($vev$) in the model
whereas the Higgs-like scalar $S$ acquires $vev$. This allows small mixing
between the $CP$-even scalars of the THDM, $h$, $H$ and $S$. In this study the
mass spectrum of new scalars is taken to be $2 m_h < m_H < 2 m_t$, $m_\chi <
m_h/2$, $m_h \lesssim m_S \lesssim m_H - m_h$, $m_A > 2 m_t$ and $m_H^\pm <
m_A$, where $m_h$ and $m_t$ is masses of the SM Higgs and top-quark
respectively, $m_H, m_A$ and $m_{H^\pm}$ are the masses of the heavy $CP$-even
scalar $H$, $CP$-odd scalar $A$, and charged Higgs $H^\pm$, respectively. A
partial list of potential search channels at the LHC has been provided with
possible phenomenological consequences. The expected phenomenology and
constraints on parameters are also discussed in a model-independent approach .


title:
Synaptic plasticity and neuronal refractory time cause scaling behaviour
  of neuronal avalanches

abstract:
  Neuronal avalanches measured in vitro and in vivo in different cortical
networks consistently exhibit power law behaviour for the size and duration
distributions with exponents typical for a mean field self-organized branching
process. These exponents are also recovered in neuronal network simulations
implementing various neuronal dynamics on different network topologies. They
can therefore be considered a very robust feature of spontaneous neuronal
activity. Interestingly, this scaling behaviour is also observed on regular
lattices in finite dimensions, which raises the question about the origin of
the mean field behaviour observed experimentally. In this study we provide an
answer to this open question by investigating the effect of activity dependent
plasticity in combination with the neuronal refractory time in a neuronal
network. Results show that the refractory time hinders backward avalanches
forcing a directed propagation. Hebbian plastic adaptation plays the role of
sculpting these directed avalanche patterns into the topology of the network
slowly changing it into a branched structure where loops are marginal.


title:
Coherent gamma photon generation in a Bose-Einstein condensate of
  $^{135m}$Cs

abstract:
  We have identified a mechanism of collective nuclear de-excitation in a
Bose-Einstein condensate of $^{135}$Cs atoms in their isomeric states,
$^{135m}$Cs, suitable for the generation of coherent gamma photons. The process
described here does not correspond to single-pass amplification, which cannot
occur in atomic systems due to the large shift between absorption and emission
lines, nor does it require the large densities associated to standard Dicke
super-radiance. It thus overcome the limitations that have been hindering the
generation of coherent gamma rays in many systems. Therefore, we propose an
approach for generation of coherent gamma rays, which relies on a combination
of well established techniques of nuclear and atomic physics, and can be
realized with currently available technology.


title: Chiral interface states in graphene $p$-$n$ junctions

abstract:
  We present a theoretical analysis of unidirectional interface states which
form near $p$-$n$ junctions in a graphene monolayer subject to a homogeneous
magnetic field. The semiclassical limit of these states corresponds to
trajectories propagating along the $p$-$n$ interface by a combined
skipping-snaking motion. Studying the two-dimensional Dirac equation with a
magnetic field and an electrostatic potential step, we provide and discuss the
exact and essentially analytical solution of the quantum-mechanical
eigenproblem for both a straight and a circularly shaped junction. The spectrum
consists of localized Landau-like and unidirectional snaking-skipping interface
states, where we always find at least one chiral interface state. For a
straight junction and at energies near the Dirac point, when increasing the
potential step height, the group velocity of this state interpolates in an
oscillatory manner between the classical drift velocity in a crossed
electromagnetic field and the semiclassical value expected for a purely snaking
motion. Away from the Dirac point, chiral interface states instead resemble the
conventional skipping (edge-type) motion found also in the corresponding
Schr\"odinger case. We also investigate the circular geometry, where chiral
interface states are predicted to induce sizeable equilibrium ring currents.


title:
Toward establishing low-lying $\Lambda$ and $\Sigma$ hyperon resonances
  with the $\bar K + d \to \pi + Y + N$ reaction

abstract:
  A model for the $\bar K d \to \pi Y N$ reactions with $Y=\Lambda, \Sigma$ is
developed, aiming at establishing the low-lying $\Lambda$ and $\Sigma$ hyperon
resonances through analyzing the forthcoming data from the J-PARC E31
experiment. The off-shell amplitudes generated from the dynamical
coupled-channels (DCC) model, which was developed in Kamano et al. [Phys. Rev.
C 90, 065204 (2014)], are used as input to the calculations of the elementary
$\bar K N \to \bar K N$ and $\bar K N \to \pi Y$ subprocesses in the $\bar K d
\to \pi Y N$ reactions. It is shown that the cross sections for the J-PARC E31
experiment with a rather high incoming-$\bar{K}$ momentum, $|\vec p_{\bar K}|=
1$ GeV, can be predicted reliably only when the input $\bar K N \to \bar K N$
amplitudes are generated from a $\bar KN$ model, such as the DCC model used in
this investigation, which describes the data of the $\bar K N$ reactions at
energies far beyond the $\bar K N$ threshold. We find that the data of the
threefold differential cross section $d\sigma/(dM_{\pi\Sigma}d\Omega_{p_n})$
for the $K^- d \to \pi \Sigma n$ reaction below the $\bar K N$ threshold can be
used to test the predictions of the resonance poles associated with
$\Lambda(1405)$. We also find that the momentum dependence of the threefold
differential cross sections for the $K^- d \to \pi^- \Lambda p$ reaction can be
used to examine the existence of a low-lying $J^P=1/2^+$ $\Sigma$ resonance
with a pole mass $M_R = 1457 -i39$ MeV, which was found from analyzing the
$K^-p$ reaction data within the employed DCC model.