title: A note on the problem of proper time in Weyl space-time

abstract:
  We discuss the question of whether or not a general Weyl structure is a
suitable mathematical model of space-time. This is an issue that has been in
debate since Weyl formulated his unified field theory for the first time. We do
not present the discussion from the point of view of a particular unification
theory, but instead from a more general standpoint, in which the viability of
such a structure as a model of space-time is investigated. Our starting point
is the well known axiomatic approach to space-time given by Elhers, Pirani and
Schild (EPS). In this framework, we carry out an exhaustive analysis of what is
required for a consistent definition for proper time and show that such a
definition leads to the prediction of the so-called "second clock effect". We
take the view that if, based on experience, we were to reject space-time models
predicting this effect, this could be incorporated as the last axiom in the EPS
approach. Finally, we provide a proof that, in this case, we are led to a Weyl
integrable space-time (WIST) as the most general structure that would be
suitable to model space-time.


title:
Puffing and micro-explosion behavior in combustion of butanol/Jet A-1
  and acetone-butanol-ethanol (A-B-E)/Jet A-1 fuel droplets

abstract:
  The present investigation deals with the puffing and micro-explosion
characteristics in the combustion of a single droplet comprising butanol/Jet
A-1, acetone-butanol-ethanol (A-B-E)/Jet A-1 blends, and A-B-E. The onset of
nucleation, growth of vapor bubble and subsequent breakup of droplet for
various fuel blends have been analyzed from the high-speed images. Puffing was
observed to be the dominant phenomenon in 30% butanol blend, while
micro-explosion was found to be the dominant one in other fuel blends (blend
with 50% butanol or 30% A-B-E or 50% A-B-E). It was observed that puffing
always preceded the micro-explosion. The probability of micro-explosion in
droplets with A-B-E blends was found to be higher than that of butanol blends.
Although the rate of bubble growth was almost similar for all butanol and A-B-E
blends, the final bubble diameter before the droplet breakup was found to be
higher for 50/50 blends than that of 30/70 blends. The occurrence of
micro-explosion shortened the droplet lifetime, and this effect appeared to be
stronger for droplets with 50/50 composition. Micro-explosion led to the
ejection of both larger and smaller secondary droplets; however, puffing
resulted in relatively smaller secondary droplets compared to micro-explosion.
Puffing/micro-explosion were also observed in the secondary droplets.


title:
On the stability of classical orbits of the hydrogen ground state in
  Stochastic Electrodynamics

abstract:
  de la Pe\~na 1980 and Puthoff 1987 show that circular orbits in the hydrogen
problem of Stochastic Electrodynamics are stable. Though the Cole-Zou 2003
simulations support the stability, our recent numerics always lead to
self-ionisation. Here the de la Pe\~na-Puthoff argument is extended to elliptic
orbits. For very eccentric orbits with energy close to zero and angular
momentum below some not-small value, there is on the average a net gain in
energy for each revolution, which explains the self-ionisation. Next, an
$1/r^2$ potential is added, which could stem from a dipolar deformation of the
nuclear charge by the electron at its moving position. This shape retains the
analytical solvability. When it is enough repulsive, the ground state of this
modified hydrogen problem is predicted to be stable. The same conclusions hold
for positronium.


title:
A study of solar photospheric temperature gradient variation using limb
  darkening measurements

abstract:
  The variation in area of quiet magnetic network measured over the sunspot
cycle should modulate the spatially averaged photospheric temperature gradient,
since temperature declines with optical depth more gradually in magnetic flux
tube atmospheres. Yet, limb darkening measurements show no dependence upon
activity level, even at an rms precision of 0.04%. We study the sensitivity of
limb darkening to changes in area filling factor using a 3D MHD model of the
magnetized photosphere. The limb darkening change expected from the measured 11
yr area variation lies below the level of measured limb darkening variations,
for a reasonable range of magnetic flux in quiet network and internetwork
regions. So the remarkably constant limb darkening observed over the solar
activity cycle is not inconsistent with the measured 11 year change in area of
quiet magnetic network. Our findings offer an independent constraint on
photospheric temperature gradient changes reported from measurements of the
solar spectral irradiance from the Spectral Irradiance Monitor (SIM), and
recently, from wavelength differential spectrophotometry using the Solar
Optical Telescope (SOT) aboard the HINODE spacecraft.


title:
On a multivariate renewal-reward process involving time delays and
  discounting: Applications to IBNR process and infinite server queues

abstract:
  This paper considers a particular renewal-reward process with multivariate
discounted rewards (inputs) where the arrival epochs are adjusted by adding
some random delays. Then this accumulated reward can be regarded as
multivariate discounted Incurred But Not Reported (IBNR) claims in actuarial
science and some important quantities studied in queueing theory such as the
number of customers in G/G/infinity queues with correlated batch arrivals. We
study the long term behavior of this process as well as its moments. Asymptotic
expressions and bounds for the quantities of our interest, and also convergence
result for the distribution of this process after renormalization, are studied,
when interarrival times and time delays are light tailed. Next, assuming
exponentially distributed delays, we derive some explicit and numerically
feasible expressions for the limiting joint moments. In such case, for an
innite server queues with renewal arrival process, we obtain limiting results
on the expectation of the workload, and the covariance of queue size and
workload. Finally, some queueing theoretic applications are providedMSC
classification: 60G50, 60K30, 62P05, 60K25


title:
Reducing bias in nonparametric density estimation via bandwidth
  dependent kernels: $L_1$ view

abstract:
  We define a new bandwidth-dependent kernel density estimator that improves
existing convergence rates for the bias, and preserves that of the variation,
when the error is measured in $L_1$. No additional assumptions are imposed to
the extant literature.


title:
Comparison of Multi Criteria Decision Making Algorithms for Ranking
  Cloud Renderfarm Services

abstract:
  Cloud services that provide a complete environment for the animators to
render their files using the resources in the cloud are called Cloud Renderfarm
Services. The objective of this work is to rank and compare the performance of
these services using two popular Multi Criteria Decision Making (MCDM)
Algorithms namely the Analytical Hierarchical Processing (AHP) and SAW (Simple
Additive Weighting) methods. The performance of three real time cloud
renderfarm services are ranked and compared based on five Quality of Service
(QoS) attributes that are important to these services namely the Render Node
Cost, File Upload Time, Availability, Elasticity and Service Response Time. The
performance of these cloud renderfarm services are ranked in four different
simulations by varying the weights assigned for each QoS attribute and the
ranking obtained are compared. The results show that AHP and SAW assigned
similar ranks to all three cloud renderfarm services for all simulations.


title:
General Analytical Method of Kibble-Zurek Mechanism for Exact Prediction
  of Topological Defects Production

abstract:
  In the field of non-equilibrium phase transitions, the Kibble-Zurek mechanism
(KZM) is undoubtedly an important discovery, pointing out that some universal
scaling rules are applied to a wide range of physical systems from quantum to
the cosmos in complex non-equilibrium continuous phase transitions. However,
except for some scaling relations in specific cases, the algebraic-based KZM
can not provide further details on the topological defect generation laws. In
this work, we propose an analytical-based KZM that can accurately predict
topological defect generation for a given quenching condition. Compared with
the conventional KZM, our theory is more accurate and more widely applicable,
especially in non-linear quenching conditions and inhomogeneous structural
systems, where it has more obvious advantages. Our work reveals a fundamental
and intrinsic mechanism in non-equilibrium phase transitions, blazing a new
trail for accurate description and manipulation of topological defect
generation.


title: Mesons in ultra-intense magnetic field: an evaded collapse

abstract:
  Spectra of $q \bar q$ mesons are investigated in the framework of the
Hamiltonian obtained from the relativistic path integral in external
homogeneous magnetic field. The spectra of all 12 spin-isospin s-wave states
generated by $\pi$- and $\rho$-mesons with different spin projections, are
studied analytically as functions of the field strength. Three types of
behavior with characteristic splittings are found. The results are in agreement
with recent lattice calculations.


title:
Gaia16apd -- a link between fast-and slowly-declining type I
  superluminous supernovae

abstract:
  We present ultraviolet, optical and infrared photometry and optical
spectroscopy of the type Ic superluminous supernova (SLSN) Gaia16apd (= SN
2016eay), covering its evolution from 26 d before the $g$-band peak to 234.1 d
after the peak. Gaia16apd was followed as a part of the NOT Unbiased Transient
Survey (NUTS). It is one of the closest SLSNe known ($z = 0.102\pm0.001$), with
detailed optical and ultraviolet (UV) observations covering the peak. Gaia16apd
is a spectroscopically typical type Ic SLSN, exhibiting the characteristic blue
early spectra with O II absorption, and reaches a peak $M_{g} = -21.8 \pm 0.1$
mag. However, photometrically it exhibits an evolution intermediate between the
fast- and slowly-declining type Ic SLSNe, with an early evolution closer to the
fast-declining events. Together with LSQ12dlf, another SLSN with similar
properties, it demonstrates a possible continuum between fast- and
slowly-declining events. It is unusually UV-bright even for a SLSN, reaching a
non-$K$-corrected $M_{uvm2} \simeq -23.3$ mag, the only other type Ic SLSN with
similar UV brightness being SN 2010gx. Assuming that Gaia16apd was powered by
magnetar spin-down, we derive a period of $P = 1.9\pm0.2$ ms and a magnetic
field of $B = 1.9\pm0.2 \times 10^{14}$ G for the magnetar. The estimated
ejecta mass is between 8 and 16 $\mathrm{M}_{\odot}$ and the kinetic energy
between 1.3 and $2.5 \times 10^{52}$ erg, depending on opacity and assuming
that the entire ejecta is swept up into a thin shell. Despite the early
photometric differences, the spectra at late times are similar to
slowly-declining type Ic SLSNe, implying that the two subclasses originate from
similar progenitors.


title:
Search-and-Fetch with 2 Robots on a Disk: Wireless and Face-to-Face
  Communication Models

abstract:
  We initiate the study of a new problem on searching and fetching in a
distributed environment concerning treasure-evacuation from a unit disk. A
treasure and an exit are located at unknown positions on the perimeter of a
disk and at known arc distance. A team of two robots start from the center of
the disk, and their goal is to fetch the treasure to the exit. At any time the
robots can move anywhere they choose on the disk, independently of each other,
with the same speed. A robot detects an interesting point (treasure or exit)
only if it passes over the exact location of that point. We are interested in
designing distributed algorithms that minimize the worst-case
treasure-evacuation time, i.e. the time it takes for the treasure to be
discovered and brought (fetched) to the exit by any of the robots.
  The communication protocol between the robots is either wireless, where
information is shared at any time, or face-to-face (i.e. non-wireless), where
information can be shared only if the robots meet. For both models we obtain
upper bounds for fetching the treasure to the exit. Our main technical
contribution pertains to the face-to-face model. More specifically, we
demonstrate how robots can exchange information without meeting, effectively
achieving a highly efficient treasure-evacuation protocol which is minimally
affected by the lack of distant communication. Finally, we complement our
positive results above by providing a lower bound in the face-to-face model.


title: An iterative inversion of weighted Radon transforms along hyperplanes

abstract:
  We propose iterative inversion algorithms for weighted Radon transforms $R_W$
along hyperplanes in $R^3$. More precisely, expandingthe weight $W = W (x,
\theta), x \in R^3 , \theta \in S^2$ , into the series of spherical harmonics
in $\theta$ and assuming that the zero order term $w_{0,0}(x)$ is not zero at
any $x \in R^3$ , we reduce the inversion of $R_W$ to solving a linear integral
equation. In addition, under the assumption that the even part of $W$ in
$\theta$ (i.e., $1/2(W (x, \theta) + W (x, -\theta))$) is close to $w_{0,0}$,
the aforementioned linear integral equation can be solved by the method of
successive approximations. Approximate inversions of $R_W$ are also given. Our
results can be considered as an extension to 3D of two-dimensional results of
Kunyansky (1992), Novikov (2014), Guillement, Novikov (2014). In our studies we
are motivated, in particular, by problems of emission tomographies in 3D. In
addition, we generalize our results to the case of dimension $n > 3$.


title: RenderSelect: a Cloud Broker Framework for Cloud Renderfarm Services

abstract:
  In the 3D studios the animation scene files undergo a process called as
rendering, where the 3D wire frame models are converted into 3D photorealistic
images. As the rendering process is both a computationally intensive and a time
consuming task, the cloud services based rendering in cloud render farms is
gaining popularity among the animators. Though cloud render farms offer many
benefits, the animators hesitate to move from their traditional offline
rendering to cloud services based render farms as they lack the knowledge,
expertise and the time to compare the render farm service providers based on
the Quality of Service (QoS) offered by them, negotiate the QoS and monitor
whether the agreed upon QoS is actually offered by the renderfarm service
providers. In this paper we propose a Cloud Service Broker (CSB) framework
called the RenderSelect that helps in the dynamic ranking, selection,
negotiation and monitoring of the cloud based render farm services. The cloud
services based renderfarms are ranked and selected services based on multi
criteria QoS requirements. Analytical Hierarchical Process (AHP), the popular
Multi Criteria Decision Making (MCDM) method is used for ranking and selecting
the cloud services based renderfarms. The AHP method of ranking is illustrated
in detail with an example. It could be verified that AHP method ranks the cloud
services effectively with less time and complexity.


title:
Bandlimited Field Reconstruction from Samples Obtained at Unknown Random
  Locations on a Grid

abstract:
  We study the sampling of spatial fields using sensors that are
location-unaware but deployed according to a known statistical distribution. It
has been shown that uniformly distributed location-unaware sensors cannot infer
bandlimited fields due to the symmetry and shift-invariance of the field.
  This work studies asymmetric (nonuniform) distributions on location-unaware
sensors that will enable bandlimited field inference. For the sake of
analytical tractability, location-unaware sensors are restricted to a discrete
grid. Oversampling followed by clustering of the samples using the probability
distribution that governs sensor placement on the grid is used to infer the
field . Based on this clustering algorithm, the main result of this work is to
find the optimal probability distribution on sensor locations that minimizes
the detection error-probability of the underlying spatial field. The proposed
clustering algorithm is also extended to include the case of signal
reconstruction in the presence of sensor noise by treating the distribution of
the noisy samples as a mixture model and using clustering to estimate the
mixture model parameters.


title: Determinizing Monitors for HML with Recursion

abstract:
  We examine the determinization of monitors for HML with recursion. We
demonstrate that every monitor is equivalent to a deterministic one, which is
at most doubly exponential in size with respect to the original monitor. When
monitors are described as CCS-like processes, this doubly exponential bound is
optimal. When (deterministic) monitors are described as finite automata (as
their LTS), then they can be exponentially more succinct than their CCS process
form.


title: Kappa-Deformations: Historical Developments and Recent Results

abstract:
  I shall recall in historical perspective some results from nineties and show
further how $\kappa$-deformed symmetries and $\kappa$-Minkowski space inspired
DSR (Doubly of Deformed Special Relativity) approach proposed after 2000. As
very recent development I shall show how to describe quantum-covariant
$\kappa$-deformed phase spaces by passing from Hopf algebras to Hopf algebroids
(arXiv:1507.02612) and I will briefly describe the $\kappa$-deformations of
$AdS_5 \times S^5$ superstring target spaces (arXiv:1510.030.83).


title:
Spontaneously Broken Asymptotic Symmetries and an Effective Action for
  Horizon Dynamics

abstract:
  Asymptotic spacetime symmetries have been conjectured to play an important
role in quantum gravity. In this paper we study the breaking of asymptotic
symmetries associated with a null horizon boundary. In two-dimensions, these
symmetries are reparametrizations of the time parameter on the horizon. We show
how this horizon reparametrization symmetry is explicitly and spontaneously
broken in dilaton gravity and construct an effective action for these
pseudo-Goldstone modes using the on-shell gravitational action for a null
boundary. The variation of this action yields the horizon constraint equation.
This action is invariant under a 2 parameter subgroup of $SL(2)$
transformations, whose Noether charges we interpret via the membrane paradigm.
We place these results in the context of recent work on the near $AdS_2$/ near
$CFT_1$ correspondence. In this setting the horizon action characterizes the
infrared regime near the horizon and has a hydrodynamical sigma model form. We
also discuss our construction in General Relativity. In the three-dimensional
case there is a natural generalization of our results. However, in higher
dimensions, the variation of the effective action only yields the Raychaudhuri
equation for small perturbations of the horizon.


title: Unit Commitment using Nearest Neighbor as a Short-Term Proxy

abstract:
  We devise the Unit Commitment Nearest Neighbor (UCNN) algorithm to be used as
a proxy for quickly approximating outcomes of short-term decisions, to make
tractable hierarchical long-term assessment and planning for large power
systems. Experimental results on updated versions of IEEE-RTS79 and IEEE-RTS96
show high accuracy measured on operational cost, achieved in runtimes that are
lower in several orders of magnitude than the traditional approach.


title:
Cyclotomic double affine Hecke algebras (with an appendix by Hiraku
  Nakajima and Daisuke Yamakawa)

abstract:
  We show that the partially spherical cyclotomic rational Cherednik algebra
(obtained from the full rational Cherednik algebra by averaging out the
cyclotomic part of the underlying reflection group) has four other
descriptions: (1) as a subalgebra of the degenerate DAHA of type A given by
generators; (2) as an algebra given by generators and relations; (3) as an
algebra of differential-reflection operators preserving some spaces of
functions; (4) as equivariant Borel-Moore homology of a certain variety. Also,
we define a new $q$-deformation of this algebra, which we call cyclotomic DAHA.
Namely, we give a $q$-deformation of each of the above four descriptions of the
partially spherical rational Cherednik algebra, replacing differential
operators with difference operators, degenerate DAHA with DAHA, and homology
with K-theory, and show that they give the same algebra. In addition, we show
that spherical cyclotomic DAHA are quantizations of certain multiplicative
quiver and bow varieties, which may be interpreted as K-theoretic Coulomb
branches of a framed quiver gauge theory. Finally, we apply cyclotomic DAHA to
prove new flatness results for various kinds of spaces of $q$-deformed
quasiinvariants. In the appendix by H. Nakajima and D. Yamakawa (added in
version 2), the authors explain the relations between multiplicative bow
varieties and (various versions of) multiplicative quiver varieties for a
cyclic quiver.


title: Sizes and Distances in High Energy Physics

abstract:
  This is a critical discussion of physical relevance of some space-time
characteristics which are in current use in high energy physics.


title: Low rank compact operators and Tingley's problem

abstract:
  Let $E$ and $B$ be arbitrary weakly compact JB$^*$-triples whose unit spheres
are denoted by $S(E)$ and $S(B)$, respectively. We prove that every surjective
isometry $f: S(E) \to S(B)$ admits an extension to a surjective real linear
isometry $T: E\to B$. This is a complete solution to Tingley's problem in the
setting of weakly compact JB$^*$-triples. Among the consequences, we show that
if $K(H,K)$ denotes the space of compact operators between arbitrary complex
Hilbert spaces $H$ and $K$, then every surjective isometry $f: S(K(H,K)) \to
S(K(H,K))$ admits an extension to a surjective real linear isometry $T:
K(H,K)\to K(H,K)$.


title:
Theoretical description of effective heat transfer between two viscously
  coupled beads

abstract:
  We analytically study the role of nonconservative forces, namely viscous
couplings, on the statistical properties of the energy flux between two
Brownian particles kept at different temperatures. From the dynamical model
describing the system, we identify an energy flow that satisfies a fluctuation
theorem both in the stationary and in transient states. In particular, for the
specific case of a linear nonconservative interaction, we derive an exact
fluctuation theorem that holds for any measurement time in the transient
regime, and which involves the energy flux alone. Moreover, in this regime the
system presents an interesting asymmetry between the hot and cold particles.
The theoretical predictions are in good agreement with the experimental results
already presented in our previous article [B{\'e}rut et al., Phys. Rev. Lett.
116, 068301 (2016)], where we investigated the thermodynamic properties of two
Brownian particles, trapped with optical tweezers, interacting through a
dissipative hydrodynamic coupling.


title: On the multiplicative order of the roots of $bX^{q^r+1}-aX^{q^r}+dX-c$

abstract:
  In this paper, we find a lower bound for the order of the group $\langle
\theta+\alpha\rangle \subset \overline{\mathbb F_{q}}^*$, where $\alpha\in
\mathbb F_{q}$, $\theta$ is a generic root of the polynomial
$F_{A,r}(X)=bX^{q^r+1}-aX^{q^r}+dX-c\in \mathbb F_{q}[X]$ and $ad-bc\ne0$.


title:
Bandwidth selection for kernel estimators of the spatial intensity
  function

abstract:
  We discuss and compare various approaches to the problem of bandwidth
selection for kernel estimators of intensity functions of spatial point
processes. We also propose a new method based on the Campbell formula applied
to the reciprocal intensity function. The new method is fully non-parametric,
does not require knowledge of the product densities, and is not restricted to a
specific class of point process models.


title:
Constraints from Faraday rotation on the magnetic field structure in the
  Galactic halo

abstract:
  We examine the constraints imposed by Faraday rotation measures of
extragalactic point sources on the structure of the magnetic field in the halo
of our Galaxy. Guided by radio polarization observations of external spiral
galaxies, we look in particular into the possibility that field lines in the
Galactic halo have an X shape. We employ the analytical models of spiraling,
possibly X-shape magnetic fields derived in a previous paper to generate
synthetic all-sky maps of the Galactic Faraday depth, which we fit to an
observational reference map with the help of Markov Chain Monte Carlo
simulations. We find that the magnetic field in the Galactic halo is slightly
more likely to be bisymmetric (azimuthal wavenumber, $m = 1$) than axisymmetric
($m = 0$). If it is indeed bisymmetric, it must appear as X-shaped in radio
polarization maps of our Galaxy seen edge-on from outside, but if it is
actually axisymmetric, it must instead appear as nearly parallel to the
Galactic plane.


title: Constraints on pulsar masses from the maximum observed glitch

abstract:
  Pulsar glitches, sudden jumps in frequency in otherwise steadily spinning
down radio pulsars, offer a unique glimpse into the superfluid interior of
neutron stars. The exact trigger of these events remains, however, elusive and
this has hampered attempts to use glitch observations to constrain fundamental
physics. In this paper we propose a new method to measure the mass of glitching
pulsars, using observations of the maximum glitch recorded in a star, together
with state of the art microphysical models of the pinning interaction between
superfluid vortices and ions in the crust. Studying systematically all the
presently observed large glitchers, we find an inverse correlation between size
of the maximum glitch and the pulsar mass. Our procedure will allow current and
future observations of glitching pulsars to constrain not only the physics of
glitch models but also the equation of state of dense matter in neutron star
interiors.


title:
Modeling of Radiation Damage Effects in Silicon Detectors at High
  Fluences HL-LHC with Sentaurus TCAD

abstract:
  In this work we propose the application of an enhanced radiation damage model
based on the introduction of deep level traps / recombination centers suitable
for device level numerical simulation of silicon detectors at very high
fluences (e.g. 2.0x10E16 1 MeV equivalent neutrons/cm2). We present the
comparison between simulation results and experimental data for p-type
substrate structures in different operating conditions (temperature and biasing
voltages) for fluences up to 2.2x10E16 neutrons/cm2. The good agreement between
simulation findings and experimental measurements fosters the application of
this modeling scheme to the optimization of the next silicon detectors to be
used at HL-LHC.


title:
Effects of distinct ion temperatures on the head-on collision and phase
  shifts of dust acoustic one and multi-solitons in dusty plasmas

abstract:
  The propagation characteristics and interactions between the dust acoustic
(DA) one and multi solitons in an unmagnetized dusty plasmas composing
negatively charged mobile dust, Boltzmann distributed electrons, nonextensive
distributed cold and nonthermal distributed hot ions are studied. The well
known extended Poincar Lighthill Kuo (PLK) method is employed to derive the two
sided Korteweg de Vries (KdV) equations. The solutions of KdV equations are
constructed using the Hirota method both for one and multi solitons. The phase
shifts are determined for the interaction of one, two and three DA solitons.
The effects of plasma parameters on the head on collision of DA one as well as
multi solitons and their corresponding phase shifts are investigated.


title: Nuclear pasta and supernova neutrinos at late times

abstract:
  Nuclear pasta, with nucleons arranged into tubes, sheets, or other complex
shapes, is expected in core collapse supernovae (SNe) at just below nuclear
density. We calculate the additional opacity from neutrino-pasta coherent
scattering using molecular dynamics simulations. We approximately include this
opacity in simulations of SNe. We find that pasta slows neutrino diffusion and
greatly increases the neutrino signal at late times of 10 or more seconds after
stellar core collapse. This signal, for a galactic SN, should be clearly
visible in large detectors such as Super-Kamiokande.


abstract:
  In this article, we initiate the study of Bloch type spaces on the unit ball
of a Hilbert space. As applications, the Hardy-Littlewood theorem in
infinite-dimensional Hilbert spaces and characterizations of some holomorphic
function spaces related to the Bloch type space are presented.


title:
Behavior-Based Machine-Learning: A Hybrid Approach for Predicting Human
  Decision Making

abstract:
  A large body of work in behavioral fields attempts to develop models that
describe the way people, as opposed to rational agents, make decisions. A
recent Choice Prediction Competition (2015) challenged researchers to suggest a
model that captures 14 classic choice biases and can predict human decisions
under risk and ambiguity. The competition focused on simple decision problems,
in which human subjects were asked to repeatedly choose between two gamble
options.
  In this paper we present our approach for predicting human decision behavior:
we suggest to use machine learning algorithms with features that are based on
well-established behavioral theories. The basic idea is that these
psychological features are essential for the representation of the data and are
important for the success of the learning process. We implement a vanilla model
in which we train SVM models using behavioral features that rely on the
psychological properties underlying the competition baseline model. We show
that this basic model captures the 14 choice biases and outperforms all the
other learning-based models in the competition. The preliminary results suggest
that such hybrid models can significantly improve the prediction of human
decision making, and are a promising direction for future research.


title: End-to-End Training of Hybrid CNN-CRF Models for Stereo

abstract:
  We propose a novel and principled hybrid CNN+CRF model for stereo estimation.
Our model allows to exploit the advantages of both, convolutional neural
networks (CNNs) and conditional random fields (CRFs) in an unified approach.
The CNNs compute expressive features for matching and distinctive color edges,
which in turn are used to compute the unary and binary costs of the CRF. For
inference, we apply a recently proposed highly parallel dual block descent
algorithm which only needs a small fixed number of iterations to compute a
high-quality approximate minimizer. As the main contribution of the paper, we
propose a theoretically sound method based on the structured output support
vector machine (SSVM) to train the hybrid CNN+CRF model on large-scale data
end-to-end. Our trained models perform very well despite the fact that we are
using shallow CNNs and do not apply any kind of post-processing to the final
output of the CRF. We evaluate our combined models on challenging stereo
benchmarks such as Middlebury 2014 and Kitti 2015 and also investigate the
performance of each individual component.


title: Burst and Outburst Characteristics of Magnetar 4U 0142+61

abstract:
  We have compiled the most comprehensive burst sample from magnetar 4U
0142+61, comprising 27 bursts from its three burst-active episodes in 2011,
2012 and the latest one in 2015 observed with Swift/BAT and Fermi/GBM. Bursts
from 4U 0142+61 morphologically resemble typical short bursts from other
magnetars. However, 4U 0142+61 bursts are less energetic compared to the bulk
of magnetar bursts. We uncovered an extended tail emission following a burst on
2015 February 28, with a thermal nature, cooling over a time-scale of several
minutes. During this tail emission, we also uncovered pulse peak phase aligned
X-ray bursts , which could originate from the same underlying mechanism as that
of the extended burst tail, or an associated and spatially coincident but
different mechanism.


title:
Android Code Protection via Obfuscation Techniques: Past, Present and
  Future Directions

abstract:
  Mobile devices have become ubiquitous due to centralization of private user
information, contacts, messages and multiple sensors. Google Android, an
open-source mobile Operating System (OS), is currently the market leader.
Android popularity has motivated the malware authors to employ set of cyber
attacks leveraging code obfuscation techniques. Obfuscation is an action that
modifies an application (app) code, preserving the original semantics and
functionality to evade anti-malware. Code obfuscation is a contentious issue.
Theoretical code analysis techniques indicate that, attaining a verifiable and
secure obfuscation is impossible. However, obfuscation tools and techniques are
popular both among malware developers (to evade anti-malware) and commercial
software developers (protect intellectual rights). We conducted a survey to
uncover answers to concrete and relevant questions concerning Android code
obfuscation and protection techniques. The purpose of this paper is to review
code obfuscation and code protection practices, and evaluate efficacy of
existing code de-obfuscation tools. In particular, we discuss Android code
obfuscation methods, custom app protection techniques, and various
de-obfuscation methods. Furthermore, we review and analyse the obfuscation
techniques used by malware authors to evade analysis efforts. We believe that,
there is a need to investigate efficiency of the defense techniques used for
code protection. This survey would be beneficial to the researchers and
practitioners, to understand obfuscation and de-obfuscation techniques to
propose novel solutions on Android.


title:
Existence and stability of spatial plane waves for the incompressible
  Navier-Stokes in $\mathbb{R}^3$

abstract:
  We consider the three-dimensional incompressible Navier-Stokes equation on
the whole space. We observe that this system admits a $L^\infty$ family of
global spatial plane wave solutions, which are connected with the
two-dimensional equation. We then proceed to prove local well-posedness over a
space which includes $L^3(\mathbb{R}^3)$ and these solutions. Finally, we prove
$L^3$-stability of spatial plane waves, with no condition on their size.


title: Logarithmic Picard groups, chip firing, and the combinatorial rank

abstract:
  Illusie has suggested that one should think of the classifying group of
$M_X^{gp}$-torsors on a logarithmically smooth curve $X$ over a standard
logarithmic point as a logarithmic analogue of the Picard group of $X$. This
logarithmic Picard group arises naturally as a quotient of the algebraic Picard
group by lifts of the chip firing relations of the associated dual graph. We
connect this perspective to Baker and Norine's theory of ranks of divisors on a
finite graph, and to Amini and Baker's metrized complexes of curves. Moreover,
we propose a definition of a combinatorial rank for line bundles on $X$ and
prove that an analogue of the Riemann-Roch formula holds for our combinatorial
rank. Our proof proceeds by carefully describing the relationship between the
logarithmic Picard group on a logarithmic curve and the Picard group of the
associated metrized complex. This approach suggests a natural categorical
framework for metrized complexes, namely the category of logarithmic curves.


title: Slice starlike functions over quaternions

abstract:
  In this paper, we initiate the study of the geometric function theory for
slice starlike functions over quaternions and its subclasses. This allows us to
answer negatively some questions about the Bieberbach conjecture, the growth,
distortion, and covering theorems for slice regular functions. Precisely, we
find that the Bieberbach conjecture holds true for slice starlike functions in
contrast to the fact that the Bieberbach conjecture fails for biholomorphic
starlike mappings in higher dimensions. We also establish some sharp versions
of the growth, distortion, and covering theorems for quaternions.


title:
Reconstruction of primary vertices at the ATLAS experiment in Run 1
  proton-proton collisions at the LHC

abstract:
  This paper presents the method and performance of primary vertex
reconstruction in proton-proton collision data recorded by the ATLAS experiment
during Run 1 of the LHC. The studies presented focus on data taken during 2012
at a centre-of-mass energy of $\sqrt{s} = 8$ TeV. The performance has been
measured as a function of the number of interactions per bunch crossing over a
wide range, from one to seventy. The measurement of the position and size of
the luminous region and its use as a constraint to improve the primary vertex
resolution are discussed. A longitudinal vertex position resolution of about 30
micrometers is achieved for events with high multiplicity of reconstructed
tracks. The transverse position resolution is better than 20 micrometers and is
dominated by the precision on the size of the luminous region. An analytical
model is proposed to describe the primary vertex reconstruction efficiency as a
function of the number of interactions per bunch crossing and of the
longitudinal size of the luminous region. Agreement between the data and the
predictions of this model is better than 3% up to seventy interactions per
bunch crossing.


title:
A rare mutation model in a spatial heterogeneous environment: the Hawk
  and Dove game

abstract:
  We propose a stochastic model in evolutionary game theory where individuals
(or subpopulations) can mutate changing their strategies randomly (but rarely)
and explore the external environment. This environment affects the selective
pressure by modifying the payoff arising from the interactions between
strategies. We derive a Fokker-Plank integro-differential equation and provide
Monte-Carlo simulations for the Hawks vs Doves game. In particular we show
that, in some cases, taking into account the external environment favors the
persistence of the low-fitness strategy.


title: Biphoton transmission through non-unitary objects

abstract:
  Losses should be accounted for in a complete description of quantum imaging
systems, and yet they are often treated as undesirable and largely neglected.
In conventional quantum imaging, images are built up by coincidence detection
of spatially entangled photon pairs (biphotons) transmitted through an object.
However, as real objects are non-unitary (absorptive), part of the transmitted
state contains only a single photon, which is overlooked in traditional
coincidence measurements. The single photon part has a drastically different
spatial distribution than the two-photon part. It contains information both
about the object, and, remarkably, the spatial entanglement properties of the
incident biphotons. We image the one- and two-photon parts of the transmitted
state using an electron multiplying CCD array both as a traditional camera and
as a massively parallel coincidence counting apparatus, and demonstrate
agreement with theoretical predictions. This work may prove useful for photon
number imaging and lead to techniques for entanglement characterization that do
not require coincidence measurements.


title:
Finite-temperature conductance of strongly interacting quantum wire with
  a nuclear spin order

abstract:
  We study the temperature dependence of the electrical conductance of a clean
strongly interacting quantum wire in the presence of a helical nuclear spin
order. The nuclear spin helix opens a temperature-dependent partial gap in the
electron spectrum. Using a bosonization framework we describe the gapped
electron modes by sine-Gordon-like kinks. We predict an internal resistivity
caused by an Ohmic-like friction these kinks experience via interacting with
gapless excitations. As a result, the conductance rises from $G=e^2/h$ at
temperatures below the critical temperature when nuclear spins are fully
polarized to $G=2e^2/h$ at higher temperatures when the order is destroyed,
featuring a relatively wide plateau in the intermediate regime. The theoretical
results are compared with the experimental data for GaAs quantum wires obtained
recently by Scheller et al. [Phys. Rev. Lett. 112, 066801 (2014)].


title: Defective 2-colorings of planar graphs without 4-cycles and 5-cycles

abstract:
  Let $G$ be a graph without 4-cycles and 5-cycles. We show that the problem to
determine whether $G$ is $(0,k)$-colorable is NP-complete for each positive
integer $k.$ Moreover, we construct non-$(1,k)$-colorable planar graphs without
4-cycles and 5-cycles for each positive integer $k.$ Finally, we prove that $G$
is $(d_1,d_2)$-colorable where $(d_1,d_2)=(4,4), (3,5),$ and $(2,9).$


title: Quantum State Transfer via Noisy Photonic and Phononic Waveguides

abstract:
  We describe a quantum state transfer protocol, where a quantum state of
photons stored in a first cavity can be faithfully transferred to a second
distant cavity via an infinite 1D waveguide, while being immune to arbitrary
noise (e.g. thermal noise) injected into the waveguide. We extend the model and
protocol to a cavity QED setup, where atomic ensembles, or single atoms
representing quantum memory, are coupled to a cavity mode. We present a
detailed study of sensitivity to imperfections, and develop a quantum error
correction protocol to account for random losses (or additions) of photons in
the waveguide. Our numerical analysis is enabled by Matrix Product State
techniques to simulate the complete quantum circuit, which we generalize to
include thermal input fields. Our discussion applies both to photonic and
phononic quantum networks.


title: Intracity quantum communication via thermal microwave networks

abstract:
  Communication over proven-secure quantum channels is potentially one of the
most wide-ranging applications of currently developed quantum technologies. It
is generally envisioned that in future quantum networks, separated nodes
containing stationary solid-state or atomic qubits are connected via the
exchange of optical photons over large distances. In this work we explore an
intriguing alternative for quantum communication via all-microwave networks. To
make this possible, we describe a general protocol for sending quantum states
through thermal channels, even when the number of thermal photons in the
channel is much larger than one. The protocol can be implemented with
state-of-the-art superconducting circuits and enables the transfer of quantum
states over distances of ~100 m via microwave transmission lines cooled to only
T=4K. This opens up completely new possibilities for quantum communication
within and across buildings, and consequently, for the implementation of
intra-city quantum networks based on microwave technology only.


title: Likelihood-free inference by ratio estimation

abstract:
  We consider the problem of parametric statistical inference when likelihood
computations are prohibitively expensive but sampling from the model is
possible. Several so-called likelihood-free methods have been developed to
perform inference in the absence of a likelihood function. The popular
synthetic likelihood approach infers the parameters by modelling summary
statistics of the data by a Gaussian probability distribution. In another
popular approach called approximate Bayesian computation, the inference is
performed by identifying parameter values for which the summary statistics of
the simulated data are close to those of the observed data. Synthetic
likelihood is easier to use as no measure of `closeness' is required but the
Gaussianity assumption is often limiting. Moreover, both approaches require
judiciously chosen summary statistics. We here present an alternative inference
approach that is as easy to use as synthetic likelihood but not as restricted
in its assumptions, and that, in a natural way, enables automatic selection of
relevant summary statistic from a large set of candidates. The basic idea is to
frame the problem of estimating the posterior as a problem of estimating the
ratio between the data generating distribution and the marginal distribution.
This problem can be solved by logistic regression, and including regularising
penalty terms enables automatic selection of the summary statistics relevant to
the inference task. We illustrate the general theory on canonical examples and
employ it to perform inference for challenging stochastic nonlinear dynamical
systems and high-dimensional summary statistics.


title:
Accurate method of verified computing for solutions of semilinear heat
  equations

abstract:
  We provide an accurate verification method for solutions of heat equations
with a superlinear nonlinearity. The verification method numerically proves the
existence and local uniqueness of the exact solution in a neighborhood of a
numerically computed approximate solution. Our method is based on a fixed-point
formulation using the evolution operator, an iterative numerical verification
scheme to extend a time interval in which the validity of the solution can be
verified, and rearranged error estimates for avoiding the propagation of an
overestimate. As a result, compared with the previous verification method using
the analytic semigroup, our method can enclose the solution for a longer time.
Some numerical examples are presented to illustrate the efficiency of our
verification method.


title:
Hard X-ray Spectral Investigations of Gamma-ray Bursts, 120521C and
  130606A, at High-redshift z~6

abstract:
  This study presents the temporal and spectral analysis of the prompt emission
of two high-redshift gamma-ray bursts (GRBs), 120521C at $z\sim6$ and 130606A
at $z\sim5.91$, which were performed using the Swift-XRT/BAT and the Suzaku-WAM
simultaneously. Based on follow-up XRT observations, the longest durations of
the prompt emissions were approximately $80$ s (120521C) and $360$ s (130606A)
in the rest frame of each GRB, which are categorized as long-duration GRBs, but
are insufficiently long compared with the predicted duration of GRBs that
originate from first-generation stars. Because of the wide bandpass of the
instruments covering the ranges of 15 keV--5 MeV (BAT-WAM) and 0.3 keV--5.0 MeV
(XRT-BAT-WAM), we successfully determined the $\nu F_{\nu}$ peak energies
$E_{\rm peak}^{\rm src}$ of $682^{+845}_{-207}$ keV and $1209^{+553}_{-304}$
keV in the rest frame, and the isotropic-equivalent radiated energies $E_{\rm
iso}$ of $(8.25^{+2.24}_{-1.96})\times10^{52}$ erg and
$(2.82^{+0.17}_{-0.71})\times10^{53}$ erg, respectively. These obtained
characteristic parameters are in accordance with the well-known relation
between $E_{\rm peak}^{\rm src}$ and $E_{\rm iso}$ (Amati relation). In
addition, we examined the relations between $E_{\rm peak}^{\rm src}$ and the
1-s peak luminosity, $L_{\rm p}$, or the geometrical corrected radiated energy,
$E_{\gamma}$, and confirmed the $E_{\rm peak}^{\rm src}$-$L_{\rm p}$ (Yonetoku)
and $E_{\rm peak}^{\rm src}$-$E_{\gamma}$ (Ghirlanda) relations. The results
implied that these high-redshift GRBs at $z\sim6$, expected as having radiated
from the reionization epoch, have similar properties as that of X-ray prompt
emission with low-redshift GRBs.


title:
Swings and roundabouts: Optical Poincar\'e spheres for polarization and
  Gaussian beams

abstract:
  The connection between Poincar\'e spheres for polariz-ation and Gaussian
beams is explored, focusing on the interpretation of elliptic polarization in
terms of the isotropic 2-dimensional harmonic oscillator in Hamiltonian
mechanics, its canonical quantization and semiclassical interpretation. This
leads to the interpretation of structured Gaussian modes, the Hermite-Gaussian,
Laguerre-Gaussian and Generalized Hermite-Laguerre Gaussian modes as
eigenfunctions of operators corresponding to the classical constants of motion
of the 2-dimensional oscillator, which acquire an extra significance as
families of classical ellipses upon semiclassical quantization.


title:
Gaseous abundances in planetary nebulae: What have we learned in the
  past five years?

abstract:
  Nearly 50 years ago, in the proceedings of the first IAU symposium on
planetary nebulae, Lawrence H. Aller and Stanley J. Czyzak said that "the
problem of determination of the chemical compositions of planetary and other
gaseous nebulae constitutes one of the most exasperating problems in
astrophysics". Although the situation has greatly improved over the years, many
important problems are still open and new questions have arrived to the field,
which still is an active field of study. Here I will review some of the main
aspects related to the determination of gaseous abundances in PNe and some
relevant results derived in the last five years, since the last IAU symposium
on PNe.


title: Survival probability in a quenched Majorana chain with an impurity

abstract:
  We investigate the dynamics of a one-dimensional $p$-wave superconductor with
next-nearest-neighbor hopping and superconducting interaction derived from a
three-spin interacting Ising model in transverse field by mapping to Majorana
fermions. The next-nearest-neighbor hopping term leads a new topological phase
containing two zero-energy Majorana modes at each end of an open chain,
compared to a nearest-neighbor $p$-wave superconducting chain. We study the
Majorana survival probability (MSP) of a particular Majorana edge state when
the initial Hamiltonian ($H_i$) is changed to the quantum critical as well as
off-critical final Hamiltonian ($H_f$) which additionally contains an impurity
term ($H_{imp}$) that breaks the time-reversal invariance. For the off-critical
quenching inside the new topological phase with $H_f= H_i +H_{imp}$, and small
impurity strength ($\lambda_d$), we observe a perfect oscillation of the MSP as
a function of time with a single frequency (determined by the impurity strength
$\lambda_d$) that can be analyzed from an equivalent two-level problem. On the
other hand, the MSP shows a beating like structure with time for quenching to
the phase boundary separating the topological phase (with two edge Majoranas at
each edge) and the non-topological phase where the additional frequency is
given by inverse of the system size. We attribute this behavior of the MSP to
the modification of the energy levels of the final Hamiltonian due to the
application of the impurity term.


title: Assessing pattern recognition or labeling in streams of temporal data

abstract:
  In the data deluge context, pattern recognition or labeling in streams is
becoming quite an essential and pressing task as data flows inside always
bigger streams. The assessment of such tasks is not so easy when dealing with
temporal data, namely patterns that have a duration (a beginning and an end
time-stamp). This paper details an approach based on an editing distance to
first align a sequence of labeled temporal segments with a ground truth
sequence, and then, by back-tracing an optimal alignment path, to provide a
confusion matrix at the label level. From this confusion matrix, standard
evaluation measures can easily be derived as well as other measures such as the
"latency" that can be quite important in (early) pattern detection
applications.


title:
Couple stress theories: Theoretical underpinnings and practical aspects
  from a new energy perspective

abstract:
  In this paper, we examine theoretical and practical aspects of several
versions of couple stress theory. This includes indeterminate
Mindlin-Tiersten-Koiter couple stress theory (MTK-CST), indeterminate symmetric
modified couple stress theory (M-CST) and determinate skew-symmetric consistent
couple stress theory (C-CST). We observe that MTK-CST and M-CST not only suffer
from inconsistencies, these theories also cannot describe properly several
elementary deformations, such as pure torsion of a circular bar and pure
bending of a plate. By using an energy method, we also demonstrate another
aspect of the inconsistency of the indeterminate MTK-CST and M-CST for elastic
solids. This is achieved by deriving the governing equilibrium equations for
elastic bodies in MTK-CST, M-CST and C-CST. This development shows that the
direct minimization of the total potential energy for MTK-CST and M-CST
violates the divergence free compatibility condition of the rotation vector
field. On the other hand, the direct minimization of the total potential energy
for C-CST satisfies this compatibility condition automatically. This result
demonstrates another aspect of the inner consistency of C-CST.


title:
Real analyticity of radiation patterns of resonant states on
  asymptotically hyperbolic manifolds

abstract:
  We show that resonant states in scattering on asymptotically hyperbolic
man-ifolds that are analytic near conformal infinity, have analytic radiation
patterns at infinity. On even asymptotically hyperbolic manifolds we also show
that smooth solutions of Vasy operators with analytic coefficients are also
analytic. That answer a question of M.Zworski ([14] Conjecture 2). The proof is
based on previous results of Baouendi-Goulaouic and Bolley-Camus-Hanouzet and
for convenience of the reader we present an outline of the proof of the latter.


title:
Band bending at the interface in Polyethylene-MgO nanocomposite
  dielectric

abstract:
  Polymer nanocomposite dielectrics are promising materials for electrical
insulation in high voltage applications. However, the physics behind their
performance is not yet fully understood. We use density functional theory to
investigate electronic properties of the interfacial area in magnesium
oxide-polyethylene nanocomposite. Our results demonstrate polyethylene
conduction band matching with conduction bands of different surfaces of
magnesium oxide. Such band bending results in long range potential wells of up
to 2.6 eV deep. Furthermore, the fundamental influence of silicon treatment on
magnesium oxide surface properties is assessed. We report a reduction of the
surface-induced states at the silicon-treated interface. The simulations
provide information used to propose a new model for charge trapping in
nanocomposite dielectrics.


title:
SeDMiD for Confusion Detection: Uncovering Mind State from Time Series
  Brain Wave Data

abstract:
  Understanding how brain functions has been an intriguing topic for years.
With the recent progress on collecting massive data and developing advanced
technology, people have become interested in addressing the challenge of
decoding brain wave data into meaningful mind states, with many machine
learning models and algorithms being revisited and developed, especially the
ones that handle time series data because of the nature of brain waves.
However, many of these time series models, like HMM with hidden state in
discrete space or State Space Model with hidden state in continuous space, only
work with one source of data and cannot handle different sources of information
simultaneously. In this paper, we propose an extension of State Space Model to
work with different sources of information together with its learning and
inference algorithms. We apply this model to decode the mind state of students
during lectures based on their brain waves and reach a significant better
results compared to traditional methods.


title:
Learning Radio Resource Management in 5G Networks: Framework,
  Opportunities and Challenges

abstract:
  In the fifth generation (5G) of mobile broadband systems, Radio Resources
Management (RRM) will reach unprecedented levels of complexity. To cope with
the ever more sophisticated RRM functionalities and with the growing variety of
scenarios, while carrying out the prompt decisions required in 5G, this
manuscript presents a lean 5G RRM architecture that capitalizes on recent
advances in the field of machine learning in combination with the large amount
of data readily available in the network from measurements and system
observations. The architecture relies on a single general-purpose learning
framework conceived for RRM directly using the data gathered in the network.
The complexity of RRM is shifted to the design of the framework, whilst the RRM
algorithms derived from this framework are executed in a computationally
efficient distributed manner at the radio access nodes. The potential of this
approach is verified in a pair of pertinent scenarios and future directions on
applications of machine learning to RRM are discussed.


title: The Kac-Wakimoto Equation Is Not Integrable

abstract:
  We study the $(3+1)$-dimensional eight-order nonlinear wave equation
associated with the principal representation of the exceptional affine Lie
algebra $E_6^{(1)}$, which was constructed by Kac and Wakimoto and stated that
$N$-soliton solution of the equation can be formulated. We show that the
equation is not Hirota integrable since it does not have three-soliton
solution, even it has one- and two-soliton solutions.


title: Geometric Monte Carlo and Black Janus Geometries

abstract:
  We describe an application of the Monte Carlo method to the Janus deformation
of the black brane background. We present numerical results for three and five
dimensional black Janus geometries with planar and spherical interfaces. In
particular, we argue that the 5D geometry with a spherical interface has an
application in understanding the finite temperature bag-like QCD model via the
AdS/CFT correspondence. The accuracy and convergence of the algorithm are
evaluated with respect to the grid spacing. The systematic errors of the method
are determined using an exact solution of 3D black Janus. This numerical
approach for solving linear problems is unaffected initial guess of a trial
solution and can handle an arbitrary geometry under various boundary conditions
in the presence of source fields.


title:
Delay-Induced Depinning of Localized Structures in a spatially
  inhomogeneous Swift-Hohenberg Model

abstract:
  We report on the dynamics of localized structures in an inhomogeneous
Swift-Hohenberg model describing pattern formation in the transverse plane of
an optical cavity. This real order parameter equation is valid close to the
second order critical point associated with bistability. The optical cavity is
illuminated by an inhomogeneous spatial gaussian pumping beam, and subjected to
time-delayed feedback. The gaussian injection beam breaks the translational
symmetry of the system by exerting an attracting force on the localized
structure. We show that the localized structure can be pinned to the center of
the inhomogeneity, suppressing the delay-induced drift bifurcation that has
been reported in the particular case where the injection is homogeneous,
assumming a continous wave operation. Under an inhomogeneous spatial pumping
beam, we perform the stability analysis of localized solutions to identify
different instability regimes induced by time-delayed feedback. In particular,
we predict the formation of two-arm spirals, as well as oscillating and
depinning dynamics caused by the interplay of an attracting inhomogeneity and
destabilizing time-delayed feedback. The transition from oscillating to
depinning solutions is investigated by means of numerical continuation
techniques. Analytically, we use two approaches based on either an order
parameter equation, describing the dynamics of the localized structure in the
vicinity of the Hopf bifurcation or an overdamped dynamics of a particle in a
potential well generated by the inhomogeneity. In the later approach, the
time-delayed feedback acts as a driving force.


title: Signal Detection in Singular Value Decomposition

abstract:
  We develop an Iterative version of the Singular Value Decomposition (ISVD)
that jointly analyzes a finite number of data matrices to identify signals that
correlate among the rows of matrices. It will be illustrated how the supervised
analysis of a big data set by another complex, multi-dimensional phenotype
using the ISVD algorithm could lead to signal detection.


title: Reliably Learning the ReLU in Polynomial Time

abstract:
  We give the first dimension-efficient algorithms for learning Rectified
Linear Units (ReLUs), which are functions of the form $\mathbf{x} \mapsto
\max(0, \mathbf{w} \cdot \mathbf{x})$ with $\mathbf{w} \in \mathbb{S}^{n-1}$.
Our algorithm works in the challenging Reliable Agnostic learning model of
Kalai, Kanade, and Mansour (2009) where the learner is given access to a
distribution $\cal{D}$ on labeled examples but the labeling may be arbitrary.
We construct a hypothesis that simultaneously minimizes the false-positive rate
and the loss on inputs given positive labels by $\cal{D}$, for any convex,
bounded, and Lipschitz loss function.
  The algorithm runs in polynomial-time (in $n$) with respect to any
distribution on $\mathbb{S}^{n-1}$ (the unit sphere in $n$ dimensions) and for
any error parameter $\epsilon = \Omega(1/\log n)$ (this yields a PTAS for a
question raised by F. Bach on the complexity of maximizing ReLUs). These
results are in contrast to known efficient algorithms for reliably learning
linear threshold functions, where $\epsilon$ must be $\Omega(1)$ and strong
assumptions are required on the marginal distribution. We can compose our
results to obtain the first set of efficient algorithms for learning
constant-depth networks of ReLUs.
  Our techniques combine kernel methods and polynomial approximations with a
"dual-loss" approach to convex programming. As a byproduct we obtain a number
of applications including the first set of efficient algorithms for "convex
piecewise-linear fitting" and the first efficient algorithms for noisy
polynomial reconstruction of low-weight polynomials on the unit sphere.


title: Oriented Bipartite Graphs and the Goldbach Graph

abstract:
  In this paper, we study oriented bipartite graphs. In particular, we
introduce "bitransitive" graphs. Several characterizations of bitransitive
bitournaments are obtained. We show that bitransitive bitounaments are
equivalent to acyclic bitournaments. As applications, we characterize acyclic
bitournaments with Hamiltonian paths, determine number of non-isomorphic
acyclic bitournaments of a given order, and solve the graph-isomorphism problem
in linear time for acyclic bitournaments. Next, we prove the well-known
Caccetta-H$\ddot{\textrm{a}}$ggkvist Conjecture for oriented bipartite graphs
for some cases for which it is unsolved in general oriented graphs. We also
introduce the concept of undirected as well as oriented "odd-even" graphs. We
characterize bipartite graphs and acyclic oriented bipartite graphs in terms of
them. In fact, we show that any bipartite graph (acyclic oriented bipartite
graph) can be represented by some odd-even graph (oriented odd-even graph). We
obtain some conditions for connectedness of odd-even graphs. This study of
odd-even graphs and their connectedness is motivated by a special family of
odd-even graphs which we call "Goldbach graphs". We show that the famous
Goldbach's conjecture is equivalent to the connectedness of Goldbach graphs.
Several other number theoretic conjectures (e.g., the twin prime conjecture)
are related to various parameters of Goldbach graphs, motivating us to study
the nature of vertex-degrees and independent sets of these graphs. Finally, we
observe Hamiltonian properties of some odd-even graphs related to Goldbach
graphs for small number of vertices.


title:
Global regularity for 2D Boussinesq temperature patches with no
  diffusion

abstract:
  This paper considers the temperature patch problem for the incompressible
Boussinesq system with no diffusion and viscosity in the whole space
$\mathbb{R}^2$. We prove that for initial patches with $W^{2,\infty}$ boundary
the curvature remains bounded for all time. The proof explores new
cancellations that allow us to bound $\nabla^2u$, even for those components
given by time dependent singular integrals with kernels with nonzero mean on
circles. In addition, we give a different proof of the $C^{1+\gamma}$
regularity result in [23], $0<\gamma<1$, using the scale of Sobolev spaces for
the velocity. Furthermore, taking advantage of the new cancellations, we go
beyond to show the persistence of regularity for $C^{2+\gamma}$ patches.


title: Novel Role of Superfluidity in Low-Energy Nuclear Reactions

abstract:
  We demonstrate, within symmetry unrestricted time-dependent density
functional theory, the existence of new effects in low-energy nuclear reactions
which originate from superfluidity. The dynamics of the pairing field induces
solitonic excitations in the colliding nuclear systems, leading to qualitative
changes in the reaction dynamics. The solitonic excitation prevents collective
energy dissipation and effectively suppresses fusion cross section. We
demonstrate how the variations of the total kinetic energy of the fragments can
be traced back to the energy stored in the superfluid junction of colliding
nuclei. Both contact time and scattering angle in non-central collisions are
significantly affected. The modification of the fusion cross section and
possibilities for its experimental detection are discussed.


title: On the Redshifts of the BL Lac 3FGL J0909.0+2310 and its Close Companion

abstract:
  We report on the redshift of the BL Lac object 3FGL J0909.0+2310 based on
observations obtained with the OSIRIS Multi Object Spectrograph (MOS) mounted
on the 10.4-m Gran Telescopio Canarias. A redshift of 0.432+/-0.002 was
obtained by the identification of three absorption features (CaII K&H and
G-band) detected in the spectrum of the BL Lac host galaxy. The closest object
to the BL Lac at an angular separation of 3.8" (~21 kpc at this distance) has a
similar redshift of 0.431+/-0.002. This companion galaxy could be the most
likely cause of the nuclear activity as postulated by studies based on more
extended data sets and cosmological models. MOS allows us to study the object's
neighbourhood within a field of view of approximately 7'x2' and we find two
small groups of galaxies at redshifts 0.28 and 0.39 which are probably not
related to the activity of 3FGL~J0909.0+2310.


title:
GaN Nanowall Network: A new possible route to obtain efficient p-GaN and
  enhanced light extraction

abstract:
  We demonstrate that GaN formed in a Nanowall Network (NwN) morphology can
overcome fundamental limitations in optoelectronic devices, and enable high
light extraction and effective Mg incorporation for efficient p-GaN. We report
the growth of Mg doped GaN Nanowall network (NwN) by plasma assisted molecular
beam epitaxy (PA-MBE) that is characterized by Photoluminescence (PL)
spectroscopy, Raman spectroscopy, high-resolution X-ray diffraction (HR-XRD),
X-ray photoelectron spectroscopy (XPS) and Secondary ion mass spectroscopy
(SIMS). We record a photo-luminescence enhancement ($ \approx $3.2 times) in
lightly doped GaN as compared to that of undoped NwN. Two distinct (and broad)
blue luminescence peaks appears at 2.95 and 2.7 eV for the heavily doped GaN
(Mg $>10^{20}$ atoms $cm^{-3}$), of which the 2.95 eV peak is sensitive to
annealing is observed. XPS and SIMS measurements estimate the incorporated Mg
concentration to be $10^{20}$ atoms $cm^{-3}$ in GaN NwN morphology, while
retaining its band edge emission at $\approx$ 3.4 eV. A higher Mg accumulation
towards the GaN/Al$_2$O$_3$ interface as compared to the surface was observed
from SIMS measurements.


title:
Magnetic field sensing with quantum error detection under the effect of
  energy relaxation

abstract:
  A solid state spin is an attractive system with which to realize an
ultra-sensitive magnetic field sensor. A spin superposition state will acquire
a phase induced by the target field, and we can estimate the field strength
from this phase. Recent studies have aimed at improving sensitivity through the
use of quantum error correction (QEC) to detect and correct any bit-flip errors
that may occur during the sensing period. Here, we investigate the performance
of a two-qubit sensor employing QEC and under the effect of energy relaxation.
Surprisingly, we find that the standard QEC technique to detect and recover
from an error does not improve the sensitivity compared with the single-qubit
sensors. This is a consequence of the fact that the energy relaxation induces
both a phase-flip and a bit-flip noise where the former noise cannot be
distinguished from the relative phase induced from the target fields. However,
we have found that we can improve the sensitivity if we adopt postselection to
discard the state when error is detected. Even when quantum error detection is
moderately noisy, and allowing for the cost of the postselection technique, we
find that this two-qubit system shows an advantage in sensing over a single
qubit in the same conditions.


title: Magnetic field induced criticality in superconducting two-leg ladders

abstract:
  We study critical singularities in the d-wave-like superconducting phase of
the hole-doped Hubbard model of repulsively interacting electrons, defined on a
two-leg ladder, induced by a magnetic field applied parallel to the ladder
plane. We argue that, provided the lowest energy spin excitations in doped
ladders carry as well charge quantum numbers, the low temperature thermodynamic
quantities, such as specific heat coefficient and magnetic susceptibility will
show logarithmic singularities in quantum critical regime. This behavior is in
drastic contrast with the magnetic field induced criticality in undoped Mott
insulator ladders, which is governed by the zero scle-factor universality with
its hallmark square root singularities.


title:
Regularized maximum likelihood estimation of covariance matrices of
  elliptical distributions

abstract:
  The maximum likelihood principle is widely used in statistics, and the
associated estimators often display good properties. indeed maximum likelihood
estimators are guaranteed to be asymptotically efficient under mild conditions.
However in some settings, one has too few samples to get a good estimation. It
then becomes desirable to take into account prior information about the
distribution one wants to estimate. One possible approach is to extend the
maximum likelihood principle in a bayesian context, which then becomes a
maximum a posteriori estimate; however this requires a distribution model on
the distribution parameters. We shall therefore concentrate on the alternative
approach of regularized estimators in this paper; we will show how they can be
naturally introduced in the framework of maximum likelihood estimation, and how
they can be extended to form robust estimators which can reject outliers.


title:
Unconventional fermionic pairing states in a monochromatically tilted
  optical lattice

abstract:
  We study the one-dimensional attractive Fermionic Hubbard model under the
influence of periodic driving with the time-dependent density matrix
renormalization group method. We show that the system can be driven into an
unconventional pairing state characterized by a condensate made of Cooper-pairs
with a finite center-of-mass momentum similar to a Fulde-Ferrell state. We
obtain results both in the laboratory and the rotating reference frames
demonstrating that the momentum of the condensate can be finely tuned by
changing the ratio between the amplitude and the frequency of the driving. In
particular, by quenching this ratio to the value corresponding to suppression
of the tunnelling and the Coulomb interaction strength to zero, we are able to
"freeze" the condensate. We finally study the effects of different initial
conditions, and compare our numerical results to those obtained from a
time-independent Floquet theory in the large frequency regime. Our work offers
the possibility of engineering and controlling unconventional pairing states in
fermionic condensates.


title:
On Equivalence of Binary Asymmetric Channels regarding the Maximum
  Likelihood Decoding

abstract:
  We study the problem of characterizing when two memoryless binary asymmetric
channels, described by their transition probabilities $(p,q)$ and $(p',q')$,
are equivalent from the point of view of maximum likelihood decoding (MLD) when
restricted to $n$-block binary codes. This equivalence of channels induces a
partition (depending on $n$) on the space of parameters $(p,q)$ into regions
associated with the equivalence classes. Explicit expressions for describing
these regions, their number and areas are derived. Some perspectives of
applications of our results to decoding problems are also presented.


title:
Complementing the ground-based CMB Stage-4 experiment on large scales
  with the PIXIE satellite

abstract:
  We present forecasts for cosmological parameters from future Cosmic Microwave
Background (CMB) data measured by the Stage-4 (S4) generation of ground-based
experiments in combination with large-scale anisotropy data from the PIXIE
satellite. We demonstrate the complementarity of the two experiments and focus
on science targets that benefit from their combination. We show that a
cosmic-variance-limited measurement of the optical depth to reionization
provided by PIXIE, with error $\sigma(\tau)=0.002$, is vital for enabling a
5$\sigma$ detection of the sum of the neutrino masses when combined with a
CMB-S4 lensing measurement, and with lower-redshift constraints on the growth
of structure and the distance-redshift relation. Parameters characterizing the
epoch of reionization will also be tightly constrained; PIXIE's $\tau$
constraint converts into $\sigma(\rm{z_{re}})=0.2$ for the mean time of
reionization, and a kinematic Sunyaev-Zel'dovich measurement from S4 gives
$\sigma(\Delta \rm{z_{re}})=0.03$ for the duration of reionization. Both PIXIE
and S4 will put strong constraints on primordial tensor fluctuations, vital for
testing early-universe models, and will do so at distinct angular scales. We
forecast $\sigma(r)\approx 5\times10^{-4}$ for a signal with a tensor-to-scalar
ratio $r=10^{-3}$, after accounting for diffuse foreground removal and
de-lensing. The wide and dense frequency coverage of PIXIE results in an
expected foreground-degradation factor on $r$ of only $\approx$25%. By
measuring large and small scales PIXIE and S4 will together better limit the
energy injection at recombination from dark matter annihilation, with $p_{\rm
ann}<0.09 \times 10^{-6} \ {\rm m^3/s/Kg}$ projected at 95% confidence.
Cosmological parameters measured from the damping tail with S4 will be best
constrained by polarization, which has the advantage of minimal contamination
from extragalactic emission.


title: Maximum a posteriori learning in demand competition games

abstract:
  We consider an inventory competition game between two firms. The question we
address is this: If players do not know the opponent's action and opponent's
utility function can they learn to play the Nash policy in a repeated game by
observing their own sales? In this work it is proven that by means of Maximum A
Posteriori (MAP) estimation, players can learn the Nash policy. It is proven
that players' actions and beliefs do converge to the Nash equilibrium.


title:
Convergence of numerical approximations to non-linear continuity
  equations with rough force fields

abstract:
  We prove quantitative regularity estimates for the solutions to non-linear
continuity equations and their discretized numerical approximations on
Cartesian grids when advected by a rough force field. This allow us to recover
the known optimal regularity for linear transport equations but also to obtain
the convergence of a wide range of numerical schemes. Our proof is based on a
novel commutator estimates, quantifying and extending to the non-linear case
the classical commutator approach of the theory of renormalized solutions.


title: Geant4 simulations of the lead fluoride calorimeter

abstract:
  In this paper we simulate the emission by charged particles in complex
structures with help of Geant4. We take into account Cherenkov radiation,
transition radiation, bremsstrahlung, pair production and other accompanying
processes. As an application we investigate the full size electromagnetic
calorimeter for the muon g-2 experiment at Fermilab. A calorimeter module (24
are expected in the experiment) consists of a Delrin front panel for
installation of the laser calibration system, 54 PbF2 Cherenkov crystals
wrapped by the black Millipore paper, and silicon photo-multiplier sensors. We
report here on a simulation of radiation from positrons passing through the
calorimeter system. We carry out the simulation using Geant4 toolkit, which
provides a complete set of tools for all areas of detector simulation:
geometry, tracking, detector response, run, event and track management, and
visualization. We consider Cherenkov photons expansion when a positron moves
down through the calorimeter at the arbitrary angle of incidence. Both spectral
and angular distributions of Cherenkov optical photons in different parts of
the calorimeter system have been evaluated as well as the transition radiation
and pre-shower distributions from the panel and from the Al vacuum chamber of
the storage ring. (The paper is in progress).


title:
An analytic evaluation of Kane fermion magneto-optics in two and three
  dimensions

abstract:
  We calculate and present an analytic form of the magneto-optical conductivity
for the gapped low-energy Kane model in two and three dimensions separately.
The two-dimensional case maps onto the $\alpha$-$\mathcal{T}_3$ model at a
particular value of $\alpha=1/\sqrt{3}$. In two dimensions, two chiral sectors
exist, between which there are no optically activated transitions. In three
dimensions, the extra dimension of dispersion mixes the two sectors so that
intra- and inter-sector transitions can occur. The latter type of transition
can be separated out via circular polarizations of light and shows a distinct
signature in the transverse conductivity.


title: PDR Emission from the Arched-Filaments and Nearby Positions

abstract:
  We investigate the physical conditions of the gas, atomic and molecular, in
the filaments in the context of Photo-Dissociation Regions (PDRs) using the
KOSMA-PDR mode of clumpy clouds. We also compare the [CII] vs. [NII] integrated
intensity predictions in Abel et al. 2005 for HII regions and adjacent PDRs in
the Galactic disk, and check for their applicability under the extreme physical
conditions present in the GC. Our preliminary results show that observed
integrated intensities are well reproduced by the PDR model. The gas is exposed
to a relatively low Far-UV field between 10^2 - 10^3 Draine fields. The total
volume hydrogen density is well constrained between 10^4 - 10^5 cm^-3. The
hydrogen ionization rate due to cosmic-rays varies between 10^-15 and 4x10^-15
s^-1, with the highest value ~ 10^-14 s^-1 found towards G0.07+0.04. Our
results show that the line-of-sight contribution to the total distance of the
filaments to the Arches Cluster is not negligible. The spatial distribution of
the [CII]/[NII] ratio shows that the integrated intensity ratios are fairly
homogeneously distributed for values below 10 in energy units. Calculations
including variation on the [C/N] abundance ratio show that tight constraints on
this ratio are needed to reproduce the observations.


title:
Refinements of the 2-dimensional Strichartz estimate on the maximum wave
  packet

abstract:
  The Strichartz estimates for Schr\"{o}dinger equations can be improved when
the data is spread out in either physical or frequency space. In this paper we
give refinements of the 2-dimensional homogeneous Strichartz estimate on the
maximum size of a single wave packet. Different approaches are used in the
proofs, including arithmetic approaches, polynomial partitioning, and the $l^2$
Decoupling Theorem, for different cases. We also give examples to show that the
refinements we obtain cannot be further improved when $2 \leq p \leq 4$ and $p
= 6$.


title:
Some Subclasses of Linear Languages based on Nondeterministic Linear
  Automata

abstract:
  In this paper we consider the class of lambda-nondeterministic linear
automata as a model of the class of linear languages. As usual in other
automata models, lambda-moves do not increase the acceptance power. The main
contribution of this paper is to introduce the deterministic linear automata
and even linear automata, i.e. the natural restriction of nondeterministic
linear automata for the deterministic and even linear language classes,
respectively. In particular, there are different, but not equivalents,
proposals for the class of "deterministic" linear languages. We proved here
that the class of languages accepted by the deterministic linear automata are
not contained in any of the these classes and in fact they properly contain
these classes. Another, contribution is the generation of an infinite hierarchy
of formal languages, going from the class of languages accepted by
deterministic linear automata and achieved, in the limit, the class of linear
languages.


title:
Anchored Correlation Explanation: Topic Modeling with Minimal Domain
  Knowledge

abstract:
  While generative models such as Latent Dirichlet Allocation (LDA) have proven
fruitful in topic modeling, they often require detailed assumptions and careful
specification of hyperparameters. Such model complexity issues only compound
when trying to generalize generative models to incorporate human input. We
introduce Correlation Explanation (CorEx), an alternative approach to topic
modeling that does not assume an underlying generative model, and instead
learns maximally informative topics through an information-theoretic framework.
This framework naturally generalizes to hierarchical and semi-supervised
extensions with no additional modeling assumptions. In particular, word-level
domain knowledge can be flexibly incorporated within CorEx through anchor
words, allowing topic separability and representation to be promoted with
minimal human intervention. Across a variety of datasets, metrics, and
experiments, we demonstrate that CorEx produces topics that are comparable in
quality to those produced by unsupervised and semi-supervised variants of LDA.


title: On the Kodaira dimension of maximal orders

abstract:
  Let $\kk$ be an algebraically closed field of characteristic zero and $\KK$ a
finitely generated field over $\kk$. Let $\Sigma$ be a central simple
$\KK$-algebra, $X$ a normal projective model of $\KK$ and $\Lambda$ a sheaf of
maximal $\Osh_X$-orders in $\Sigma$. There is a ramification $\QQ$-divisor
$\Delta$ on $X$, which is related to the canonical bimodule $\omega_\Lambda$ by
an adjunction formula. It only depends on the class of $\Sigma$ in the Brauer
group of $\KK$. When the numerical abundance conjecture holds true, or when
$\Sigma$ is a central simple algebra, we show that the Gelfand-Kirillov
dimension (or GK dimension) of the canonical ring of $\Lambda$ is one more than
the Iitaka dimension (or D-dimension) of the log pair $(X,\Delta)$. In the case
that $\Sigma$ is a division algebra, we further show that this GK dimension is
also one more than the transcendence degree of the division algebra of degree
zero fractions of the canonical ring of $\Lambda$. We prove that these
dimensions are birationally invariant when the b-log pair determined by the
ramification divisor has b-canonical singularities. In that case we refer to
the Iitaka (or D-dimension) of $(X,\Delta)$ as the Kodaira dimension of the
order $\Lambda$. For this, we establish birational invariance of the Kodaira
dimension of b-log pairs with b-canonical singularities. We also show that the
Kodaira dimension can not decrease for an embedding of central simple algebras,
finite dimensional over their centres, which induces a Galois extension of
their centres, and satisfies a condition on the ramification which we call an
effective embedding. For example, this condition holds if the target central
simple algebra has the property that its period equals its index.


title: Blocs de chiffres de taille croissante dans les nombres premiers

abstract:
  In this article, we prove a theorem \`a la Mauduit et Rivat (prime number
theorem, Moebius randomness principle) for functions that count digital blocks
whose length is a growing function tending to infinity. These sequences are not
automatic. To obtain our results, we control sums of type I and II and use an
adapted and refined version of the carry propagation property as well as
standard methods from harmonic analysis.


title: Quantum illumination reveals phase-shift inducing cloaking

abstract:
  In quantum illumination entangled light is employed to enhance the detection
accuracy of an object when compared with the best classical protocol. On the
other hand, cloaking is a stealth technology based on covering a target with a
material deflecting the light around the object to avoid its detection. Here,
we propose a quantum illumination protocol especially adapted to quantum
microwave technology. This protocol seizes the phase-shift induced by some
cloaking techniques, such as scattering reduction, allowing for a $3$ dB
improvement in the detection of a cloaked target. The method can also be
employed for the detection of a phase-shift in bright environments in different
frequency regimes. Finally, we study the minimal efficiency required by the
photocounter for which the quantum illumination protocol still shows a gain
with respect to the classical protocol.


title: Entanglement Entropy in Causal Set Theory

abstract:
  Entanglement entropy is now widely accepted as having deep connections with
quantum gravity. It is therefore desirable to understand it in the context of
causal sets, especially since they provide in a natural manner the UV cutoff
needed to render entanglement entropy finite. Formulating a notion of
entanglement entropy in a causal set is not straightforward because the type of
canonical hypersurface-data on which its definition typically relies is not
available. Instead, we appeal to the more global expression given in
arXiv:1205.2953 which, for a gaussian scalar field, expresses the entropy of a
spacetime region in terms of the field's correlation function within that
region (its "Wightman function" $W(x,x')$). Carrying this formula over to the
causal set, one obtains an entropy which is both finite and of a Lorentz
invariant nature. We evaluate this global entropy-expression numerically for
certain regions (primarily order-intervals or "causal diamonds") within causal
sets of 1+1 dimensions. For the causal-set counterpart of the entanglement
entropy, we obtain, in the first instance, a result that follows a (spacetime)
volume law instead of the expected (spatial) area law. We find, however, that
one obtains an area law if one truncates the commutator function ("Pauli-Jordan
operator") and the Wightman function by projecting out the eigenmodes of the
Pauli-Jordan operator whose eigenvalues are too close to zero according to a
geometrical criterion which we describe more fully below. In connection with
these results and the questions they raise, we also study the "entropy of
coarse-graining" generated by thinning out the causal set, and we compare it
with what one obtains by similarly thinning out a chain of harmonic
oscillators, finding the same, "universal" behaviour in both cases.


title: Hadamard states for quantum Abelian duality

abstract:
  Abelian duality is realized naturally by combining differential cohomology
and locally covariant quantum field theory. This leads to a C$^*$-algebra of
observables, which encompasses the simultaneous discretization of both magnetic
and electric fluxes. We discuss the assignment of physically well-behaved
states to such algebra and the properties of the associated GNS triple. We show
that the algebra of observables factorizes as a suitable tensor product of
three C$^*$-algebras: the first factor encodes dynamical information, while the
other two capture topological data corresponding to electric and magnetic
fluxes. On the former factor we exhibit a state whose two-point correlation
function has the same singular structure of a Hadamard state. Specifying
suitable counterparts also on the topological factors we obtain a state for the
full theory, providing ultimately a unitary implementation of Abelian duality.


title:
Weighted bandits or: How bandits learn distorted values that are not
  expected

abstract:
  Motivated by models of human decision making proposed to explain commonly
observed deviations from conventional expected value preferences, we formulate
two stochastic multi-armed bandit problems with distorted probabilities on the
cost distributions: the classic $K$-armed bandit and the linearly parameterized
bandit. In both settings, we propose algorithms that are inspired by Upper
Confidence Bound (UCB), incorporate cost distortions, and exhibit sublinear
regret assuming \holder continuous weight distortion functions. For the
$K$-armed setting, we show that the algorithm, called W-UCB, achieves
problem-dependent regret $O(L^2 M^2 \log n/ \Delta^{\frac{2}{\alpha}-1})$,
where $n$ is the number of plays, $\Delta$ is the gap in distorted expected
value between the best and next best arm, $L$ and $\alpha$ are the H\"{o}lder
constants for the distortion function, and $M$ is an upper bound on costs, and
a problem-independent regret bound of
$O((KL^2M^2)^{\alpha/2}n^{(2-\alpha)/2})$. We also present a matching lower
bound on the regret, showing that the regret of W-UCB is essentially
unimprovable over the class of H\"{o}lder-continuous weight distortions. For
the linearly parameterized setting, we develop a new algorithm, a variant of
the Optimism in the Face of Uncertainty Linear bandit (OFUL) algorithm called
WOFUL (Weight-distorted OFUL), and show that it has regret $O(d\sqrt{n} \;
\mbox{polylog}(n))$ with high probability, for sub-Gaussian cost distributions.
Finally, numerical examples demonstrate the advantages resulting from using
distortion-aware learning algorithms.


title:
Sedimentation of elongated non-motile prolate spheroids in homogenous
  isotropic turbulence

abstract:
  Phytoplankton are the foundation of aquatic food webs. Through
photosynthesis, phytoplankton draw down CO2 at magnitudes equivalent to forests
and other terrestrial plants and convert it to organic material that is then
consumed by other organisms of phytoplankton in higher trophic levels.
Mechanisms that affect local concentrations and velocities are of primary
significance to many encounter-based processes in the plankton including
prey-predator interactions, fertilization and aggregate formation. We report
results from simulations of sinking phytoplankton, considered as elongated
spheroids, in homogenous isotropic turbulence to answer the question of whether
trajectories and velocities of sinking phytoplankton are altered by turbulence.
We show in particular that settling spheroids with physical characteristics
similar to those of diatoms weakly cluster and preferentially sample regions of
down-welling flow, corresponding to an increase of the mean settling speed with
respect to the mean settling speed in quiescent fluid. We explain how different
parameters can affect the settling speed and what underlying mechanisms might
be involved. Interestingly, we observe that the increase in the aspect ratio of
the prolate spheroids can affect the clustering and the average settling speed
of particles by two mechanisms: first is the effect of aspect ratio on the
rotation rate of the particles, which saturates faster than the second
mechanism of increasing drag anisotropy.


title:
Tensor products and support varieties for some noncocommutative Hopf
  algebras

abstract:
  We explore questions of projectivity and tensor products of modules for
finite dimensional Hopf algebras. We construct many classes of examples in
which tensor powers of nonprojective modules are projective and tensor products
of modules in one order are projective but in the other order are not. Our
examples are smash coproducts with duals of group algebras, some having algebra
and coalgebra structures twisted by a cocycle. We develop a theory of support
varieties for these Hopf algebras to use as a tool in our investigations.


title:
Bose-Einstein condensation of photons and grand-canonical condensate
  fluctuations

abstract:
  We review recent experiments on the Bose-Einstein condensation of photons in
a dye-filled optical microresonator. The most well-known example of a photon
gas, photons in blackbody radiation, does not show Bose-Einstein condensation.
Instead of massively populating the cavity ground mode, photons vanish in the
cavity walls when they are cooled down. The situation is different in an
ultrashort optical cavity imprinting a low-frequency cutoff on the photon
energy spectrum that is well above the thermal energy. The latter allows for a
thermalization process in which both temperature and photon number can be tuned
independently of each other or, correspondingly, for a non-vanishing photon
chemical potential. We here describe experiments demonstrating the
fluorescence-induced thermalization and Bose-Einstein condensation of a
two-dimensional photon gas in the dye microcavity. Moreover, recent
measurements on the photon statistics of the condensate, showing Bose-Einstein
condensation in the grandcanonical ensemble limit, will be reviewed.


title:
The Area-Angular Momentum-Charge Inequality for Black Holes With
  Positive Cosmological Constant

abstract:
  We establish the conjectured area-angular momentum-charge inequality for
stable apparent horizons in the presence of a positive cosmological constant,
and show that it is saturated precisely for extreme Kerr-Newman-de Sitter
horizons. As with previous inequalities of this type, the proof is reduced to
minimizing an `area functional' related to a harmonic map energy; in this case
maps are from the 2-sphere to the complex hyperbolic plane. The proof here is
simplified compared to previous results for less embellished inequalities, due
to the observation that the functional is convex along geodesic deformations in
the target.


title:
Naming the Pain in Requirements Engineering: Contemporary Problems,
  Causes, and Effects in Practice

abstract:
  Requirements Engineering (RE) has received much attention in research and
practice due to its importance to software project success. Its
interdisciplinary nature, the dependency to the customer, and its inherent
uncertainty still render the discipline difficult to investigate. This results
in a lack of empirical data. These are necessary, however, to demonstrate which
practically relevant RE problems exist and to what extent they matter.
Motivated by this situation, we initiated the Naming the Pain in Requirements
Engineering (NaPiRE) initiative which constitutes a globally distributed,
bi-yearly replicated family of surveys on the status quo and problems in
practical RE. In this article, we report on the qualitative analysis of data
obtained from 228 companies working in 10 countries in various domains and we
reveal which contemporary problems practitioners encounter. To this end, we
analyse 21 problems derived from the literature with respect to their relevance
and criticality in dependency to their context, and we complement this picture
with a cause-effect analysis showing the causes and effects surrounding the
most critical problems. Our results give us a better understanding of which
problems exist and how they manifest themselves in practical environments.
Thus, we provide a first step to ground contributions to RE on empirical
observations which, until now, were dominated by conventional wisdom only.


title:
Quasi-invariance of countable products of Cauchy measures under
  non-unitary dilations

abstract:
  Consider an infinite sequence $(U_n)_{n\in\mathbb{N}}$ of independent Cauchy
random variables, defined by a sequence $(\delta_n)_{n\in\mathbb{N}}$ of
location parameters and a sequence $(\gamma_n)_{n\in\mathbb{N}}$ of scale
parameters. Let $(W_n)_{n\in\mathbb{N}}$ be another infinite sequence of
independent Cauchy random variables defined by the same sequence of location
parameters and the sequence $(\sigma_n\gamma_n)_{n\in\mathbb{N}}$ of scale
parameters, with $\sigma_n\neq 0$ for all $n\in\mathbb{N}$. Using a result of
Kakutani on equivalence of countably infinite product measures, we show that
the laws of $(U_n)_{n\in\mathbb{N}}$ and $(W_n)_{n\in\mathbb{N}}$ are
equivalent if and only if the sequence $(\vert
\sigma_n\vert-1)_{n\in\mathbb{N}}$ is square-summable.


title: A Note on Sachdev-Ye-Kitaev Like Model without Random Coupling

abstract:
  We study a description of the large N limit of the Sachdev-Ye-Kitaev (SYK)
model in terms of quantum mechanics without quenched disorder. Instead of
random couplings, we introduce massive scalar fields coupled to fermions, and
study a small mass limit of the theory. We show that, under a certain
condition, the correlation functions of fermions reproduce those of the SYK
model with a temperature dependent coupling constant in the large N limit. We
also discuss a supersymmetric generalization of our quantum mechanical model.
As a byproduct, we develop an efficient way of estimating the large N behavior
of correlators in the SYK model.


title: Ubiquity of non-geometry in heterotic compactifications

abstract:
  We study the effect of quantum corrections on heterotic compactifications on
elliptic fibrations away from the stable degeneration limit, elaborating on a
recent observation by Malmendier and Morrison. We show that already for the
simplest non-trivial elliptic fibration the effect is quite dramatic: the $I_1$
degeneration with trivial gauge background dynamically splits into two T-fects
with monodromy around each T-fect being (conjugate to) T-duality along one of
the legs of the $T^2$. This implies that almost every elliptic heterotic
compactification becomes a non-geometric T-fold away from the stable
degeneration limit. We also point out a subtlety due to this non-geometric
splitting at finite fiber size. It arises when determining, via
heterotic/F-theory duality, the SCFTs associated to a small number of pointlike
instantons probing heterotic ADE singularities. Along the way we resolve
various puzzles in the literature.