title:
The maximal order of semidiscrete schemes for quasilinear first order
  partial differential equations

abstract:
  We prove that a semidiscrete $(2r+1)$-point scheme for quasilinear first
order PDE cannot attain an order higher than $2r$. Moreover, if the forward
Euler fully discrete scheme obtained from the linearization about any constant
state of the semidiscrete scheme is stable, then the upper bound for the order
of the scheme is $2r-1$. This bound is attained for a wide range of schemes and
equations.


title: Spherical Harmonic Signal Covariance and Sound Field Diffuseness

abstract:
  Characterizing sound field diffuseness has many practical applications, from
room acoustics analysis to speech enhancement and sound field reproduction. In
this paper we investigate how spherical microphone arrays (SMAs) can be used to
characterize diffuseness. Due to their specific geometry, SMAs are particularly
well suited for analyzing the spatial properties of sound fields. In
particular, the signals recorded by an SMA can be analyzed in the spherical
harmonic (SH) domain, which has special and desirable mathematical properties
when it comes to analyzing diffuse sound fields. We present a new measure of
diffuseness, the COMEDIE diffuseness estimate, which is based on the analysis
of the SH signal covariance matrix. This algorithm is suited for the estimation
of diffuseness arising either from the presence of multiple sources distributed
around the SMA or from the presence of a diffuse noise background. As well, we
introduce the concept of a diffuseness profile, which consists in measuring the
diffuseness for several SH orders simultaneously. Experimental results indicate
that diffuseness profiles better describe the properties of the sound field
than a single diffuseness measurement.


title: Cosmological constraints from $\mu E$ cross-correlations

abstract:
  We derive general expressions of the $C^{\mu X}_l$, the cross correlation
function between the cosmic microwave background spectral $\mu$ distortion and
the linear perturbations in the cosmic microwave background such as the
temperature perturbations and the polarizations. The cross correlations are
known as new tests for the extremely squeezed shape of primordial
non-Gaussianity, which is inaccessible through the direct observations of the
temperature 3-point functions. Our formulae are applicable to the arbitrary
combinations of the scalar and the tensor perturbations, and we discuss the
potential for detecting these quantities. We provide signal-to-noise ratio of
the $\mu E$ as well as $\mu T$, based on an experiment like the Primordial
Inflation Explorer. We also find the signal-to-noise ratio from the scale
dependent nonlinearity. For instance, we show that $f^{\rm loc}_{\rm
NL}(k_1,k_2,k_3)=\left(k_1k_2k_3\right)^{1/3}k_0^{-1}F_0$ with $k_0=0.05{\rm
Mpc}^{-1}$ can be detectable at 1$\sigma$ level even for $F_0 \sim \mathcal
O(1)$.


title:
Hourglass Fermion Surface States in Stacked Topological Insulators with
  Nonsymmorphic Symmetry

abstract:
  Recently a nonsymmorphic topological insulator was predicted, where the
characteristic feature is the emergence of a "hourglass fermion" surface state
protected by the nonsymmorphic symmetry. Such a state has already been observed
experimentally. We propose a simple model possessing the hourglass fermion
surface state. The model is constructing by stacking the quantum-spin-Hall
insulators with the interlayer coupling introduced so as to preserve the
nonsymmorphic symmetry and the time reversal symmetry. The Dirac theory is also
derived, whose analytical results reproduce the hourglass fermion surface state
remarkably well. Furthermore, we discuss how the hourglass state is destroyed
by introducing perturbations based on the symmetry analysis. Our results show
that the hourglass fermion surface state is universal in the helical edge
system with the nonsymmorphic symmetry.


title: Casimir energies of self-similar plate configurations

abstract:
  We construct various self-similar configurations using parallel
$\delta$-function plates and show that it is possible to evaluate the Casimir
interaction energy of these configurations using the idea of self-similarity
alone. We restrict our analysis to interactions mediated by a scalar field, but
the extension to electromagnetic field is immediate. Our work unveils an easy
and powerful method that can be easily employed to calculate the Casimir
energies of a class of self-similar configurations. As a highlight, in an
example, we determine the Casimir interaction energy of a stack of parallel
plates constructed by positioning $\delta$-function plates at the points
constituting the Cantor set, a prototype of a fractal. This, to our knowledge,
is the first time that the Casimir energy of a fractal configuration has been
reported. Remarkably, the Casimir energy of some of the configurations we
consider turn out to be positive, and a few even have zero Casimir energy. For
the case of positive Casimir energy that is monotonically decreasing as the
stacking parameter increases the interpretation is that the pressure of vacuum
tends to inflate the infinite stack of plates. We further support our results,
derived using the idea of self-similarity alone, by rederiving them using the
Green's function formalism. These expositions gives us insight into the
connections between the regularization methods used in quantum field theories
and regularized sums of divergent series in number theory.


title:
Why is Posterior Sampling Better than Optimism for Reinforcement
  Learning?

abstract:
  Computational results demonstrate that posterior sampling for reinforcement
learning (PSRL) dramatically outperforms algorithms driven by optimism, such as
UCRL2. We provide insight into the extent of this performance boost and the
phenomenon that drives it. We leverage this insight to establish an
$\tilde{O}(H\sqrt{SAT})$ Bayesian expected regret bound for PSRL in
finite-horizon episodic Markov decision processes, where $H$ is the horizon,
$S$ is the number of states, $A$ is the number of actions and $T$ is the time
elapsed. This improves upon the best previous bound of $\tilde{O}(H S
\sqrt{AT})$ for any reinforcement learning algorithm.


title: Serre-type equations in deep water

abstract:
  This manuscript is devoted to the modelling of water waves in the deep water
regime with some emphasis on the underlying variational structures. The present
article should be considered as a review of some existing models and modelling
approaches even if new results are presented as well. Namely, we derive the
deep water analogue of the celebrated Serre-Green-Naghdi equations which have
become the standard model in shallow water environments. The relation to
existing models is discussed. Moreover, the multi-symplectic structure of these
equations is reported as well. The results of this work can be used to develop
various types of robust structure-preserving variational integrators in deep
water. The methodology of constructing approximate models presented in this
study can be naturally extrapolated to other physical flow regimes as well.


title: Climatologies at high resolution for the earth's land surface areas

abstract:
  High resolution information on climatic conditions is essential to many
applications in environmental and ecological sciences. Here we present the
CHELSA Climatologies at high resolution for the earths land surface areas data
of downscaled model output temperature and precipitation estimates of the ERA
Interim climatic reanalysis to a high resolution of 30 arc seconds. The
temperature algorithm is based on statistical downscaling of atmospheric
temperatures. The precipitation algorithm incorporates orographic predictors
including wind fields, valley exposition, and boundary layer height with a
subsequent bias correction. The resulting data consist of a monthly temperature
and precipitation climatology for the years 1979 to 2013. We compare the data
derived from the CHELSA algorithm with other standard gridded products and
station data from the Global Historical Climate Network. We compare the
performance of the new climatologies in species distribution modelling and show
that we can increase the accuracy of species range predictions. We further show
that CHELSA climatological data has a similar accuracy as other products for
temperature but that its predictions of precipitation patterns are better.


title: Hydrodynamic spectrum of a superfluid in an elongated trap

abstract:
  --In this article we study the hydrodynamic spectrum of a superfluid confined
in a cylindrical trap. We show that the dispersion relation $\omega$(q) of the
phonon branch scales like $\sqrt$ q at large q, leading to a vanishingly small
superfluid critical velocity. In practice the critical velocity is set by the
breakdown of the hydrodynamic approximation. For a broad class of superfluids,
this entails a reduction of the critical velocity by a factor ($\omega$ $\perp$
/\"i1/2c) 1/3 with respect to the free-space prediction (here $\omega$ $\perp$
is the trapping frequency and \"i1/2c the chemical potential of the cloud).


title:
The design and basic performance of a Spiral Fiber Tracker for the
  J-PARC E36 experiment

abstract:
  A spiral fiber tracker (SFT) has been designed and produced for the J-PARC
E36 experiment as an element of the tracking system for conducting a
high-resolution momentum measurement of charge particles from kaon decays. A
novel technique to wind the pre-made fiber ribbons spirally was employed for
the configuration with four detector layers made of 1 mm diameter plastic
scintillating fibers. Good position alignment and sufficiently high detection
efficiency for charged particles with minimum ionizing energy were confirmed in
cosmic ray test. The tracker was successfully used in the E36 experiment.


title:
Steady photo-darkening of thulium alumino-silicate fibers pumped at
  $1.07~\mu m$: Quantitative effect of lanthanum, cerium and thulium

abstract:
  By pumping thulium-doped silica-based fibers at 1.07~\mu m, rapid generation
of absorbing centers leads to photo-induced attenuation (PIA). This detrimental
effect prevents exploiting laser emissions in the visible and near infrared. We
report on the characterization of the PIA versus the fiber core composition,
particularly the concentration of thulium (Tm), lanthanum (La) and cerium (Ce)
ions. We show that UV emision induced by Tm-Tm energy transfers is the source
of photo-darkening, and that lanthanum and cerium are efficient hardeners
against PIA.


title: Magnetic Properties of (La0.56Ce0.14)Sr0.30MnO3 Perovskite

abstract:
  We investigate in this paper magnetic properties of the perovskite compound
(La0.56Ce0.14)Sr0.30MnO3. The method we use here is Monte Carlo simulation, in
which we take into account different kinds of interactions between nearest and
between next-nearest magnetic ions Mn 3+ (S = 2) , Mn 4+ (S = 3/2) and Ce 3+ (S
= 1/2). Using a classical spin model, we have calculated the internal energy,
the magnetization per ion type and their corresponding magnetic susceptibility,
as well as the Edwards-Anderson order parameter for each ion kind. We also
studied the applied-field effect on the system magnetization. Our results show
a good agreement with experiments.


title:
Path integral description of combined Hamiltonian and non-Hamiltonian
  dynamics in quantum dissipative system

abstract:
  We present a numerical path-integral iteration scheme for the low dimensional
reduced density matrix of a time-dependent quantum dissipative system. Our
approach simultaneously accounts for the combined action of a microscopically
modelled pure-dephasing type coupling to a continuum of harmonic oscillators
representing, e.g., phonons, and further environmental interactions inducing
non-Hamiltonian dynamics in the inner system represented, e.g., by Lindblad
type dissipation or relaxation. Our formulation of the path-integral method
allows for a numerically exact treatment of the coupling to the oscillator
modes and moreover is general enough to provide a natural way to include
Markovian processes that are sufficiently described by rate equations. We apply
this new formalism to a model of a single semiconductor quantum dot which
includes the coupling to longitudinal acoustic phonons for two cases: a)
external laser excitation taking into account a phenomenological radiative
decay of the excited dot state and b) a coupling of the quantum dot to a single
mode of an optical cavity taking into account cavity photon losses.


title: Memory Based Collaborative Filtering with Lucene

abstract:
  Memory Based Collaborative Filtering is a widely used approach to provide
recommendations. It exploits similarities between ratings across a population
of users by forming a weighted vote to predict unobserved ratings. Bespoke
solutions are frequently adopted to deal with the problem of high quality
recommendations on large data sets. A disadvantage of this approach, however,
is the loss of generality and flexibility of the general collaborative
filtering systems. In this paper, we have developed a methodology that allows
one to build a scalable and effective collaborative filtering system on top of
a conventional full-text search engine such as Apache Lucene.


title:
Fabrication and optical characterization of long-range
  surface-plasmon-polariton waveguides in the NIR

abstract:
  We experimentally demonstrate the propagation of long-range surface
plasmon-polaritons in a nobel metal stripe waveguide at an optical wavelength
of 780 nm. To minimize propagation damping the lithographically structured
waveguide is produced from a thin gold stripe embedded in a dielectric polymer.
Our waveguide geometry supports a symmetric fundamental and anti-symmetric
first order mode. For the fundamental mode we measure a propagation loss of
$(6.12^{+0.66} _{-0.54})$ dB/mm, in good agreement with numerical simulations
using a vectorial eigenmode solver. Our results are a promising starting point
for coupling fluorescence of individual solid state quantum emitters to
integrated plasmonic waveguide structures.


title: Evaluating Unsupervised Dutch Word Embeddings as a Linguistic Resource

abstract:
  Word embeddings have recently seen a strong increase in interest as a result
of strong performance gains on a variety of tasks. However, most of this
research also underlined the importance of benchmark datasets, and the
difficulty of constructing these for a variety of language-specific tasks.
Still, many of the datasets used in these tasks could prove to be fruitful
linguistic resources, allowing for unique observations into language use and
variability. In this paper we demonstrate the performance of multiple types of
embeddings, created with both count and prediction-based architectures on a
variety of corpora, in two language-specific tasks: relation evaluation, and
dialect identification. For the latter, we compare unsupervised methods with a
traditional, hand-crafted dictionary. With this research, we provide the
embeddings themselves, the relation evaluation task benchmark for use in
further research, and demonstrate how the benchmarked embeddings prove a useful
unsupervised linguistic resource, effectively used in a downstream task.


title:
Millimeter-Wave Human Blockage at 73 GHz with a Simple Double Knife-Edge
  Diffraction Model and Extension for Directional Antennas

abstract:
  This paper presents 73 GHz human blockage measurements for a point-to-point
link with a 5 m transmitter-receiver separation distance in an indoor
environment, with a human that walked at a speed of approximately 1 m/s at a
perpendicular orientation to the line between the transmitter and receiver, at
various distances between them. The experiment measures the shadowing effect of
a moving human body when using directional antennas at the transmitter and
receiver for millimeter-wave radio communications. The measurements were
conducted using a 500 Megachips-per-second wideband correlator channel sounder
with a 1 GHz first null-to-null RF bandwidth. Results indicate high shadowing
attenuation is not just due to the human blocker but also is due to the static
directional nature of the antennas used, leading to the need for phased-array
antennas to switch beam directions in the presence of obstructions and
blockages at millimeter-waves. A simple model for human blockage is provided
based on the double knife-edge diffraction (DKED) model where humans are
approximated by a rectangular screen with infinite vertical height, similar to
the human blockage model given by the METIS project.


title: Many-body localization due to random interactions

abstract:
  The possibility of observing many body localization of ultracold atoms in a
one dimensional optical lattice is discussed for random interactions. In the
non-interacting limit, such a system reduces to single-particle physics in the
absence of disorder, i.e. to extended states. In effect the observed
localization is inherently due to interactions and is thus a genuine many-body
effect. In the system studied, many-body localization manifests itself in a
lack of thermalization visible in temporal propagation of a specially prepared
initial state, in transport properties, in the logarithmic growth of
entanglement entropy as well as in statistical properties of energy levels.


title: The appearance of non-spherical systems. Application to LMXB

abstract:
  We study the appearance of the neutron star - accretion disk system as seen
by a distant observer in the UV/X-ray domain. The observed intensity spectra
are computed assuming non-spherical geometry of the whole system, in which
outgoing spectrum is not represented by the flux spectrum, the latter being
valid for spherically symmetric objects. Intensity spectra of our model display
double bumps in UV/X-ray energy domains. Such structure is caused by the fact
that the the source is not spherically symmetric, and the proper integration of
intensity over emitted area is needed to reproduce observed spectral shape.
Relative normalization of double bump is self consistently computed by our
model. X-ray spectra of such a type were often observed in LMXB with accretion
disk, ultra luminous X-ray sources, and accreting black hole systems with hot
inner compact corona. Our model naturally explains high energy broadening of
the disk spectrum observed in some binaries. We attempted to fit our model to
X-ray data of XTE~J1709-267 from {\it XMM-Newton}. Unfortunately, the double
intensity bump predicted by our model for LMXB is located in soft X-ray domain,
uncovered by existing data for this source.


title:
Dynamical strong coupling and parametric amplification in mechanical
  modes of graphene drums

abstract:
  Mechanical resonators are ubiquitous in modern information technology. With
the ability to couple them to electromagnetic and plasmonic modes, they hold
the promise to be the key building blocks in future quantum information
technology. Graphene based resonators are of interest for technological
applications due to their high resonant frequencies, multiple mechanical modes,
and low mass. The tension mediated non-linear coupling between various modes of
the resonator can be excited in a controllable manner. Here, we engineer a
graphene resonator to have large frequency tunability at low temperatures
resulting in large intermodal coupling strength. We observe the emergence of
new eigenmodes and amplification of the coupled modes using red and blue
parametric excitation respectively. We demonstrate that the dynamical
intermodal coupling is tunable. A cooperativity of 60 between two resonant
modes of ~100 MHz is achieved in the strong coupling regime. The ability to
dynamically control the coupling between high frequency eigenmodes of a
mechanical system opens up possibility for quantum mechanical experiments at
low temperatures.


title:
The role of interstitial binding in radiation induced segregation in
  W-Re alloys

abstract:
  Due to their high strength and advantageous high-temperature properties,
tungsten-based alloys are being considered as plasma-facing candidate materials
in fusion devices. Under neutron irradiation, rhenium, which is produced by
nuclear transmutation, has been found to precipitate in elongated precipitates
forming thermodynamic intermetallic phases at concentrations well below the
solubility limit. Recent measurements have shown that Re precipitation can lead
to substantial hardening, which may have a detrimental effect on the fracture
toughness of W alloys. This puzzle of sub-solubility precipitation points to
the role played by irradiation induced defects, specifically mixed solute-W
interstitials. Here, using first-principles calculations based on density
functional theory, we study the energetics of mixed interstitial defects in
W-Re, W-V, and W-Ti alloys, as well as the heat of mixing for each
substitutional solute. We find that mixed interstitials in all systems are
strongly attracted to each other with binding energies of -2.4 to -3.2 eV and
form interstitial pairs that are aligned along parallel first-neighbor <111>
strings. Low barriers for defect translation and rotation enable defect
agglomeration and alignment even at moderate temperatures. We propose that
these elongated agglomerates of mixed-interstitials may act as precursors for
the formation of needle-shaped intermetallic precipitates. This
interstitial-based mechanism is not limited to radiation induced segregation
and precipitation in W-Re alloys but is also applicable to other body-centered
cubic alloys.


title:
Exchange couplings for Mn ions in CdTe: validity of spin models for
  dilute magnetic II-VI semiconductors

abstract:
  We employ density-functional theory (DFT) in the generalized gradient
approximation (GGA) and its extensions GGA+$U$ and GGA+Gutzwiller to calculate
the magnetic exchange couplings between pairs of Mn ions substituting Cd in a
CdTe crystal at very small doping. DFT(GGA) overestimates the exchange
couplings by a factor of three because it underestimates the charge-transfer
gap in Mn-doped II-VI semiconductors. Fixing the nearest-neighbor coupling
$J_1$ to its experimental value in GGA+$U$, in GGA+Gutzwiller, or by a simple
scaling of the DFT(GGA) results provides acceptable values for the exchange
couplings at 2nd, 3rd, and 4th neighbor distances in Cd(Mn)Te, Zn(Mn)Te,
Zn(Mn)Se, and Zn(Mn)S. In particular, we recover the experimentally observed
relation $J_4>J_2,J_3$. The filling of the Mn 3$d$-shell is not integer which
puts the underlying Heisenberg description into question. However, using a
few-ion toy model the picture of a slightly extended local moment emerges so
that an integer $3d$-shell filling is not a prerequisite for equidistant
magnetization plateaus, as seen in experiment.


title: Irreducible Ginzburg-Landau fields in dimension 2

abstract:
  Ginzburg-Landau fields are the solutions of the Ginzburg-Landau equations
which depend on two positive parameters, $\alpha$ and $\beta$. We give
conditions on $\alpha$ and $\beta$ for the existence of irreducible solutions
of these equations. Our results hold for arbitrary compact, oriented,
Riemannian 2-manifolds (for example, bounded domains in $\mathbb{R}^2$,
spheres, tori, etc.) with de Gennes-Neumann boundary conditions. We also prove
that, for each such manifold and all positive $\alpha$ and $\beta$, the
Ginzburg-Landau free energy is a Palais-Smale function on the space of gauge
equivalence classes, Ginzburg-Landau fields exist for only a finite set of
energy values, and the moduli space of Ginzburg-Landau fields is compact.


title: CALET Upper Limits on X-ray and Gamma-ray Counterparts of GW 151226

abstract:
  We present upper limits in the hard X-ray and gamma-ray bands at the time of
the LIGO gravitational-wave event GW 151226 derived from the CALorimetric
Electron Telescope (CALET) observation. The main instrument of CALET,
CALorimeter (CAL), observes gamma-rays from ~1 GeV up to 10 TeV with a field of
view of ~2 sr. The CALET gamma-ray burst monitor (CGBM) views ~3 sr and ~2pi sr
of the sky in the 7 keV - 1 MeV and the 40 keV - 20 MeV bands, respectively, by
using two different scintillator-based instruments. The CGBM covered 32.5% and
49.1% of the GW 151226 sky localization probability in the 7 keV - 1 MeV and 40
keV - 20 MeV bands respectively. We place a 90% upper limit of 2 x 10^{-7} erg
cm-2 s-1 in the 1 - 100 GeV band where CAL reaches 15% of the integrated LIGO
probability (~1.1 sr). The CGBM 7 sigma upper limits are 1.0 x 10^{-6} erg cm-2
s-1 (7-500 keV) and 1.8 x 10^{-6} erg cm-2 s-1 (50-1000 keV) for one second
exposure. Those upper limits correspond to the luminosity of 3-5 x 10^{49} erg
s-1 which is significantly lower than typical short GRBs.


title:
Neutrosophic Overset, Neutrosophic Underset, and Neutrosophic Offset.
  Similarly for Neutrosophic Over-/Under-/Off- Logic, Probability, and
  Statistics

abstract:
  Neutrosophic Over-/Under-/Off-Set and -Logic were defined by the author in
1995 and published for the first time in 2007. We extended the neutrosophic set
respectively to Neutrosophic Overset {when some neutrosophic component is over
1}, Neutrosophic Underset {when some neutrosophic component is below 0}, and to
Neutrosophic Offset {when some neutrosophic components are off the interval [0,
1], i.e. some neutrosophic component over 1 and other neutrosophic component
below 0}. This is no surprise with respect to the classical fuzzy set/logic,
intuitionistic fuzzy set/logic, or classical/imprecise probability, where the
values are not allowed outside the interval [0, 1], since our real-world has
numerous examples and applications of over-/under-/off-neutrosophic components.
For example, person working overtime deserves a membership degree over 1, while
a person producing more damage than benefit to a company deserves a membership
below 0. Then, similarly, the Neutrosophic Logic/Measure/Probability/Statistics
etc. were extended to respectively Neutrosophic Over-/Under-/Off-Logic,
-Measure, -Probability, -Statistics etc. [Smarandache, 2007].


title: PIR Array Codes with Optimal Virtual Server Rate

abstract:
  There has been much recent interest in Private information Retrieval (PIR) in
models where a database is stored across several servers using coding
techniques from distributed storage, rather than being simply replicated. In
particular, a recent breakthrough result of Fazelli, Vardy and Yaakobi
introduces the notion of a PIR code and a PIR array code, and uses this notion
to produce efficient PIR protocols.
  In this paper we are interested in designing PIR array codes. We consider the
case when we have $m$ servers, with each server storing a fraction $(1/s)$ of
the bits of the database; here $s$ is a fixed rational number with $s > 1$. A
PIR array code with the $k$-PIR property enables a $k$-server PIR protocol
(with $k\leq m$) to be emulated on $m$ servers, with the overall storage
requirements of the protocol being reduced. The communication complexity of a
PIR protocol reduces as $k$ grows, so the virtual server rate, defined to be
$k/m$, is an important parameter. We study the maximum virtual server rate of a
PIR array code with the $k$-PIR property. We present upper bounds on the
achievable virtual server rate, some constructions, and ideas how to obtain PIR
array codes with the highest possible virtual server rate. In particular, we
present constructions that asymptotically meet our upper bounds, and the exact
largest virtual server rate is obtained when $1 < s \leq 2$.
  A $k$-PIR code (and similarly a $k$-PIR array code) is also a locally
repairable code with symbol availability $k-1$. Such a code ensures $k$
parallel reads for each information symbol. So the virtual server rate is very
closely related to the symbol availability of the code when used as a locally
repairable code. The results of this paper are discussed also in this context,
where subspace codes also have an important role.


title: The a-function in three dimensions: beyond leading order

abstract:
  Recently, evidence was provided for the existence of an $a$-function for
renormalisable quantum field theories in three dimensions. An explicit
expression was given at lowest order for general theories involving scalars and
fermions, and shown to be related to the beta-functions by a gradient flow
equation with positive-definite metric as in four dimensions. Here, we extend
this lowest-order calculation to a general abelian Chern-Simons gauge theory
coupled to fermions and scalars, and derive a prediction for part of the
four-loop Yukawa beta-function. We also compute the complete four-loop Yukawa
beta-function for the scalar-fermion theory and show that it is entirely
consistent with the gradient flow equations at next-to-leading order.


title: Bell violation in the Sky

abstract:
  In this work, we have studied the possibility of setting up Bell's inequality
violating experiment in the context of cosmology, based on the basic principles
of quantum mechanics. First we start with the physical motivation of
implementing the Bell's inequality violation in the context of cosmology. Then
to set up the cosmological Bell violating test experiment we introduce a model
independent theoretical framework using which we have studied the creation of
new massive particles by implementing the WKB approximation method for the
scalar fluctuations in presence of additional time dependent mass contribution.
Next using the background scalar fluctuation in presence of new time dependent
mass contribution, we explicitly compute the expression for the one point and
two point correlation functions. Furthermore, using the results for one point
function we introduce a new theoretical cosmological parameter which can be
expressed in terms of the other known inflationary observables and can also be
treated as a future theoretical probe to break the degeneracy amongst various
models of inflation. Additionally, we also fix the scale of inflation in a
model independent way without any prior knowledge of primordial gravitational
waves. Next, we also comment on the technicalities of measurements from isospin
breaking interactions and the future prospects of newly introduced massive
particles in cosmological Bell violating test experiment. Further, we cite a
precise example of this set up applicable in the context of string theory
motivated axion monodromy model. Then we comment on the explicit role of
decoherence effect and high spin on cosmological Bell violating test
experiment. In fine, we provide a theoretical bound on the heavy particle mass
parameter for scalar fields, graviton and other high spin fields from our
proposed setup.

categories: hep-th astro-ph.CO gr-qc hep-ph quant-ph


title:
Forward production of Drell-Yan dileptons at high energies and low
  dilepton invariant masses in a $k_t$-factorization approach: Do we see onset
  of saturation?

abstract:
  We discuss Drell-Yan production of dileptons at high energies in forward
rapidity region in a hybrid high-energy approach. This approach uses
unintegrated gluon distributions in one proton and collinear quark/antiquark
distributions in the second proton. Corresponding momentum-space formula for
the differential cross sections in high-energy approximation has been derived.
The relation to the commonly used dipole approach is discussed. We conclude and
illustrate that some results of the dipole approaches are too approximate, as
far as kinemtics is considered, and in fact cannot be used for real
experiments. We find that the dipole formula is valid only in very
forward/backward rapidity regions ($|y| >$ 5). Some differential cross sections
for low-mass dilepton production are shown and compared to the LHCb and ATLAS
experimental data. In distinction to dipole approaches, we include four
Drell-Yan structure functions (the impact of interference structure functions
is rather small for typical experimental cuts). We find that both side
contributions ($g q/\bar q$ and $q/\bar q g$) have to be included even for the
LHCb rapidity coverage which is in contradiction with what is usually done in
the dipole approach. We present results for different unintegrated gluon
distributions from the literature (some of them include saturation effects). We
see no clear hints of saturation even at small $M_{ll}$.


title:
Acoustic Prism for Continuous Beam Steering Based on Piezoelectric
  Metamaterial

abstract:
  This paper investigates an acoustic prism for continuous acoustic beam
steering by a simple frequency sweep. This idea takes advantages of acoustic
wave velocity shifting in metamaterials in the vicinity of local resonance. We
apply this concept into the piezoelectric metamaterial consisting of host
medium and piezoelectric LC shunt. Theoretical modeling and FEM simulations are
carried out. It is shown that the phase velocity of acoustic wave changes
dramatically in the vicinity of local resonance. The directions of acoustic
wave can be adjusted continuously between 2 to 16 degrees by a simple sweep of
the excitation frequency. Such an electro-mechanical coupling system has a
feature of adjusting local resonance without altering the mechanical part of
the system.


title: Single- and many-particle description of scanning tunneling spectroscopy

abstract:
  Scanning tunneling spectroscopy measures how a single electron with definite
energy propagates between a sample surface and the tip of a scanning tunneling
microscope. In the simplest description, the differential conductance measured
is interpreted as the local density of states of the sample at the tip
position. This picture, however, is insufficient in some cases, since
especially smaller molecules weakly coupled with the substrate tend to have
strong Coulomb interactions when an electron is inserted or removed at the
molecule. We present theoretical approaches to go from the non-interacting and
single-particle picture to the correlated many-body regime. The methodology is
used to understand recent experiments on finite armchair graphene nanoribbons
and phthalocyanines. We also theoretically discuss the strongly-correlated
model system of fractional quantum Hall droplets.


title:
Empirically extending the range of validity of parameter-space metrics
  for all-sky searches for gravitational-wave pulsars

abstract:
  All-sky searches for gravitational-wave pulsars are generally limited in
sensitivity by the finite availability of computing resources. Semicoherent
searches are a common method of maximizing search sensitivity given a fixed
computing budget. The work of Wette and Prix [Phys. Rev. D 88, 123005 (2013)]
and Wette [Phys. Rev. D 92, 082003 (2015)] developed a semicoherent search
method which uses metrics to construct the banks of pulsar signal templates
needed to search the parameter space of interest. In this work we extend the
range of validity of the parameter-space metrics using an empirically-derived
relationship between the resolution (or mismatch) of the template banks and the
mismatch of the overall search. This work has important consequences for the
optimization of metric-based semicoherent searches at fixed computing cost.


title:
A linear lower bound for incrementing a space-optimal integer
  representation in the bit-probe model

abstract:
  We present the first linear lower bound for the number of bits required to be
accessed in the worst case to increment an integer in an arbitrary space-
optimal binary representation. The best previously known lower bound was
logarithmic. It is known that a logarithmic number of read bits in the worst
case is enough to increment some of the integer representations that use one
bit of redundancy, therefore we show an exponential gap between space-optimal
and redundant counters.
  Our proof is based on considering the increment procedure for a space optimal
counter as a permutation and calculating its parity. For every space optimal
counter, the permutation must be odd, and implementing an odd permutation
requires reading at least half the bits in the worst case. The combination of
these two observations explains why the worst-case space-optimal problem is
substantially different from both average-case approach with constant expected
number of reads and almost space optimal representations with logarithmic
number of reads in the worst case.


title: On the maximum of the C$\beta$E field

abstract:
  In this paper, we investigate the extremal values of (the logarithm of) the
characteristic polynomial of a random unitary matrix whose spectrum is
distributed according the Circular Beta Ensemble (C$\beta$E). More precisely,
if $X_n$ is this characteristic polynomial and $\mathbb{U}$ the unit circle, we
prove that: $$\sup_{z \in \mathbb{U} } \Re \log X_n(z) =
  \sqrt{\frac{2}{\beta}}
  \left(\log n - \frac{3}{4} \log \log n + \mathcal{O}(1) \right)\ ,$$ as well
as an analogous statement for the imaginary part. The notation $\mathcal{O}(1)$
means that the corresponding family of random variables, indexed by $n$, is
tight. This answers a conjecture of Fyodorov, Hiary and Keating, originally
formulated for the case where $\beta$ equals to $2$, which corresponds to the
CUE field.


title:
Light Sterile Neutrino and Dark Matter in Left-Right Symmetric Models
  Without Higgs Bidoublet

abstract:
  We present a class of left-right symmetric models where Dirac as well as
Majorana mass terms of neutrinos can arise at one-loop level in a scotogenic
fashion: with dark matter particles going inside the loop. We show the
possibility of naturally light right handed neutrinos that can have interesting
implications at neutrinoless double beta decay experiments as well as
cosmology. Apart from a stable dark matter candidate stabilised by a remnant
$Z_2$ symmetry, one can also have a long lived keV sterile neutrino dark matter
in these models. This class of models can have very different collider
signatures compared to the conventional left-right models.


title: Symmetric Polynomials in Tropical Algebra Semirings

abstract:
  The growth of tropical geometry has generated significant interest in the
tropical semiring in the past decade. However, there are other semirings in
tropical algebra that provide more information, such as the symmetrized (max,
+), Izhakian-Rowen's extended and supertropical semirings. In this paper we
identify in which of these upper-bound semirings we can express symmetric
polynomials in terms of elementary ones. This allows us to determine the
tropical algebra semirings where an analogue of the Fundamental Theorem of
Symmetric Polynomials holds and to what extent.


title: Simple Left-Right Theory: Lepton Number Violation at the LHC

abstract:
  We propose a simple left-right symmetric theory where the neutrino masses are
generated at the quantum level. In this context the neutrinos are Majorana
fermions and the model has the minimal degrees of freedom in the scalar sector
needed for symmetry breaking and mass generation. We discuss the lepton number
violating signatures with two charged leptons of different flavor and missing
energy at the Large Hadron Collider in order to understand the testability of
the theory.


title: EuCo2P2: A Model Molecular-Field Helical Heisenberg Antiferromagnet

abstract:
  The metallic compound EuCo2P2 with the body-centered tetragonal ThCr2Si2
structure containing Eu spins 7/2 was previously shown from single-crystal
neutron diffraction measurements to exhibit a helical antiferromagnetic (AFM)
structure below TN = 66.5 K with the helix axis along the c axis and with the
ordered moments aligned within the ab-plane. Here we report crystallography,
electrical resistivity, heat capacity, magnetization and magnetic
susceptibility measurements on single crystals of this compound. We demonstrate
that EuCo2P2 is a model molecular-field helical Heisenberg antiferromagnet from
comparisons of the anisotropic magnetic susceptibility chi, high-field
magnetization and magnetic heat capacity of EuCo2P2 single crystals at
temperature T < TN with the predictions of our recent formulation of molecular
field theory. Values of the Heisenberg exchange interactions between the Eu
spins are derived from the data. The low-T magnetic heat capacity ~ T^3 arising
from spin-wave excitations with no anisotropy gap is calculated and found to be
comparable to the lattice heat capacity. The density of states at the Fermi
energy of EuCo2P2 and the related compound BaCo2P2 are found from the heat
capacity data to be large, 10 and 16 states/eV per formula unit for EuCo2P2 and
BaCo2P2, respectively. These values are enhanced by a factor of ~2.5 above
those found from DFT electronic structure calculations for the two compounds.
The calculations also find ferromagnetic Eu-Eu exchange interactions within the
ab-plane and AFM interactions between nearest- and next-nearest planes, in
agreement with the MFT analysis of chi{ab}(T < TN).


title: Dominating sequences in grid-like and toroidal graphs

abstract:
  A longest sequence $S$ of distinct vertices of a graph $G$ such that each
vertex of $S$ dominates some vertex that is not dominated by its preceding
vertices, is called a Grundy dominating sequence; the length of $S$ is the
Grundy domination number of $G$. In this paper we study the Grundy domination
number in the four standard graph products: the Cartesian, the lexicographic,
the direct, and the strong product. For each of the products we present a lower
bound for the Grundy domination number which turns out to be exact for the
lexicographic product and is conjectured to be exact for the strong product. In
most of the cases exact Grundy domination numbers are determined for products
of paths and/or cycles.


title: Distributed Nonconvex Multiagent Optimization Over Time-Varying Networks

abstract:
  We study nonconvex distributed optimization in multiagent networks where the
communications between nodes is modeled as a time-varying sequence of arbitrary
digraphs. We introduce a novel broadcast-based distributed algorithmic
framework for the (constrained) minimization of the sum of a smooth (possibly
nonconvex and nonseparable) function, i.e., the agents' sum-utility, plus a
convex (possibly nonsmooth and nonseparable) regularizer. The latter is usually
employed to enforce some structure in the solution, typically sparsity. The
proposed method hinges on Successive Convex Approximation (SCA) techniques
coupled with i) a tracking mechanism instrumental to locally estimate the
gradients of agents' cost functions; and ii) a novel broadcast protocol to
disseminate information and distribute the computation among the agents.
Asymptotic convergence to stationary solutions is established. A key feature of
the proposed algorithm is that it neither requires the double-stochasticity of
the consensus matrices (but only column stochasticity) nor the knowledge of the
graph sequence to implement. To the best of our knowledge, the proposed
framework is the first broadcast-based distributed algorithm for convex and
nonconvex constrained optimization over arbitrary, time-varying digraphs.
Numerical results show that our algorithm outperforms current schemes on both
convex and nonconvex problems.


title:
Large-$N$ expansion for the time-delay matrix of ballistic chaotic
  cavities

abstract:
  We consider the $1/N$-expansion of the moments of the proper delay times for
a ballistic chaotic cavity supporting $N$ scattering channels. In the random
matrix approach, these moments correspond to traces of negative powers of
Wishart matrices. For systems with and without broken time reversal symmetry
(Dyson indices $\beta=1$ and $\beta=2$) we obtain a recursion relation, which
efficiently generates the coefficients of the $1/N$-expansion of the moments.
The integrality of these coefficients and their possible diagrammatic
interpretation is discussed.

categories: math-ph cond-mat.mes-hall cond-mat.stat-mech math.MP


title:
Improved Ab Initio Molecular Dynamics by Minimal Biasing with
  Experimental Data

abstract:
  Accounting for electrons and nuclei simultaneously is a powerful capability
of ab initio molecular dynamics (AIMD). However, AIMD is often unable to
accurately reproduce properties of systems such as water due to inaccuracies in
the underlying electronic density functionals. This shortcoming is often
addressed by added empirical corrections and/or increasing the simulation
temperature. We present here a maximum-entropy approach to directly incorporate
limited experimental data via a minimal bias. Biased AIMD simulations of water
and an excess proton in water are shown to give significantly improved
properties both for observables which were biased to match experimental data
and for unbiased observables. This approach also yields new physical insight
into inaccuracies in the underlying density functional theory as utilized in
the unbiased AIMD.


title:
Out of equilibrium stationary states, percolation, and sub-critical
  instabilities in a fully non conservative system

abstract:
  The exploration of the phase diagram of a minimal model for barchan fields
leads to the description of three distinct phases for the system: stationary,
percolable and unstable. In the stationary phase the system always reaches an
out of equilibrium, fluctuating, stationary state, independent of its initial
conditions. This state has a large and continuous range of dynamics, from
dilute -- where dunes do not interact -- to dense, where the system exhibits
both spatial structuring and collective behavior leading to the selection of a
particular size for the dunes. In the percolable phase, the system presents a
percolation threshold when the initial density increases. This percolation is
unusual, as it happens on a continuous space for moving, interacting, finite
lifetime dunes. For extreme parameters, the system exhibits a sub-critical
instability, where some of the dunes in the field grow without bound. We
discuss the nature of the asymptotic states and their relations to well-known
models of statistical physics.


title:
An implicit ODE-based numerical solver for the simulation of the
  Heisenberg-Euler equations in 3+1 dimensions

abstract:
  With the advent of ultra-high power lasers the nonlinear nature of the vacuum
of quantum electrodynamics (QED) can be probed. Due to the highly nonlinear
structure of the underlying equations new numerical algorithms are required. A
numerical scheme for simulating the nonlinear optical effects of the QED vacuum
in up to 3 spatial dimensions plus time is derived. Its properties are
discussed. The validity of the numerical approach is verified with the help of
known analytic results. The algorithm is used to explore nonlinear all optical
effects of the nonlinear vacuum for which analytic methods are inefficient or
impossible.


title:
Non-autonomous right and left multiplicative perturbations and maximal
  regularity

abstract:
  We consider the problem of maximal regularity for non-autonomous Cauchy
problems $u'(t) + B(t)A(t)u(t) + P(t)u(t) = f(t), u(0) = u_0$ and $u'(t) +
A(t)B(t)u(t) + P(t)u(t) = f (t), u(0) = u_0$. In both cases, the time dependent
operators $A(t)$ are associated with a family of sesquilinear forms and the
multiplicative left or right perturbations $B(t)$ as well as the additive
perturbation $P(t)$ are families of bounded operators on the considered Hilbert
space. We prove maximal $L_p$-regularity results and other regularity
properties for the solutions of the previous problems under minimal regularity
assumptions on the forms and perturbations.


title: Weighted Inner Products for GMRES and GMRES-DR

abstract:
  The convergence of the restarted GMRES method can be significantly improved,
for some problems, by using a weighted inner product that changes at each
restart. How does this weighting affect convergence, and when is it useful? We
show that weighted inner products can help in two distinct ways: when the
coefficient matrix has localized eigenvectors, weighting can allow restarted
GMRES to focus on eigenvalues that otherwise slow convergence; for general
problems, weighting can break the cyclic convergence pattern into which
restarted GMRES often settles. The eigenvectors of matrices derived from
differential equations are often not localized, thus limiting the impact of
weighting. For such problems, incorporating the discrete cosine transform into
the inner product can significantly improve GMRES convergence, giving a method
we call W-GMRES-DCT. Integrating weighting with eigenvalue deflation via
GMRES-DR also can give effective solutions.


title:
Orientational dynamics of colloidal ribbons self-assembled from
  microscopic magnetic ellipsoids

abstract:
  We combine experiments and theory to investigate the orientational dynamics
of dipolar ellipsoids, which self-assemble into elongated ribbon-like
structures due to the presence in each particle of a permanent magnetic moment
perpendicular to the long axis. Monodisperse hematite ellipsoids are
synthesized via sol-gel technique, and arrange into ribbons in presence of
static or time-dependent magnetic fields. We find that under an oscillating
field, the ribbons reorient perpendicular to the field direction, in contrast
with the behaviour observed under a static field. This observation is explained
theoretically by treating a chain of interacting ellipsoids as a single
particle with an orientational and demagnetizing field energy. The model allows
describing the orientational behaviour of the chain and captures well its
dynamics at different strengths of the actuating field. The understanding of
the complex dynamics and assembly of anisotropic magnetic colloids is a
necessary step towards controlling the structure formation which has direct
applications in different fluid-based microscale technologies.


title: The strong metric dimension of the power graph of a finite group

abstract:
  We characterize the strong metric dimension of the power graph of a finite
group. As applications, we compute the strong metric dimension of the power
graph of a cyclic group, an abelian group, a dihedral group or a generalized
quaternion group.


title:
Nonlinear Analysis of Chaotic Flow in a Three-Dimensional Closed-Loop
  Pulsating Heat Pipe

abstract:
  Numerical simulation has been conducted for the chaotic flow in a 3D
closed-loop pulsating heat pipe (PHP). Heat flux and constant temperature
boundary conditions were applied for evaporator and condenser sections,
respectively. Water and ethanol were used as working fluids. Volume of Fluid
(VOF) method has been employed for two-phase flow simulation. Spectral analysis
of temperature time series was carried out using Power Spectrum Density (PSD)
method. Existence of dominant peak in PSD diagram indicated periodic or
quasi-periodic behavior in temperature oscillations at particular frequencies.
Correlation dimension values for ethanol as working fluid was found to be
higher than that for water under the same operating conditions. Similar range
of Lyapunov exponent values for the PHP with water and ethanol as working
fluids indicated strong dependency of Lyapunov exponent to the structure and
dimensions of the PHP. An O-ring structure pattern was obtained for
reconstructed 3D attractor at periodic or quasi-periodic behavior of
temperature oscillations. Minimum thermal resistance of 0.85 degree/W and 0.88
degree/W were obtained for PHP with water and ethanol, respectively. Simulation
results showed good agreement with experimental results from other work under
the same operating conditions.


title: Lower Bounds for Alternating Online State Complexity

abstract:
  The notion of Online State Complexity, introduced by Karp in 1967, quantifies
the amount of states required to solve a given problem using an online
algorithm, which is represented by a deterministic machine scanning the input
from left to right in one pass. In this paper, we extend the setting to
alternating machines as introduced by Chandra, Kozen and Stockmeyer in 1976:
such machines run independent passes scanning the input from left to right and
gather their answers through boolean combinations. We devise a lower bound
technique relying on boundedly generated lattices of languages, and give two
applications of this technique. The first is a hierarchy theorem , stating that
the polynomial hierarchy of alternating online state complexity is infinite,
and the second is a linear lower bound on the alternating online state
complexity of the prime numbers written in binary. This second result
strengthens a result of Hartmanis and Shank from 1968, which implies an
exponentially worse lower bound for the same model.


title:
Size-dependence of nanosecond-scale spin-torque switching in
  perpendicularly magnetized tunnel junctions

abstract:
  We time-resolve the spin-transfer-torque-induced switching in perpendicularly
magnetized tunnel junctions of diameters from 50 to 250 nm in the thermally
activated regime. When the field and the spin-torque concur to favor the P to
AP transition, the reversal yields monotonic resistance ramps that can be
interpreted as a domain wall propagation through the device at velocities of 17
to 30 nm/ns; smaller cells switch hence faster. When the field hinders the P to
AP transition, the switching is preceded by repetitive switching attempts,
during which the resistance transiently increases until successful reversal
occurs. At 50 nm, the P to AP switching proceeds reproducibly in 3 ns, with a
monotonic increase of the device resistance. In the reverse transition (AP to
P), several reversal paths are possible even in the smallest junctions.
Besides, the non uniform nature of the response seems still present at
nanoscale, with sometimes electrical signatures of strong disorder during the
reversal. The AP to P transition is preceded by a strong instability of the AP
state in devices above 100 nm. The resistance becomes extremely agitated before
switching to P in a path yielding a slow (20-50 ns) irregular increase of the
conductance with variability. Unreversed bubbles of 60 nm can persist a few
microseconds in the largest junctions. The complexity of the AP to P switching
is reduced but not suppressed when the junctions are downsized below 60 nm. The
instability of the initial AP state is no longer detected but the other
features remain. In the smallest junctions (50 nm) we occasionally observe much
faster (sub-1 ns) switching events. We discuss the origin of the switching
asymmetry and its size dependence, with an emphasis on the role of the non
uniformities of the stray field emanating from the reference layers, which
affects the zones in which nucleation is favored.


title:
Noise and Disturbance of Qubit Measurements: An Information-Theoretic
  Characterisation

abstract:
  Information-theoretic definitions for the noise associated with a quantum
measurement and the corresponding disturbance to the state of the system have
recently been introduced [F. Buscemi et al., Phys. Rev. Lett. 112, 050401
(2014)]. These definitions are invariant under relabelling of measurement
outcomes, and lend themselves readily to the formulation of state-independent
uncertainty relations both for the joint estimate of observables (noise-noise
relations) and the noise-disturbance tradeoff. Here we derive such relations
for incompatible qubit observables, which we prove to be tight in the case of
joint estimates, and present progress towards fully characterising the
noise-disturbance tradeoff. In doing so, we show that the set of obtainable
noise-noise values for such observables is convex, whereas the conjectured form
for the set of obtainable noise-disturbance values is not. Furthermore,
projective measurements are not optimal with respect to the joint-measurement
noise or noise-disturbance tradeoffs. Interestingly, it seems that four-outcome
measurements are needed in the former case, whereas three-outcome measurements
are optimal in the latter.


title:
Integration by parts and its applications of a new nonlocal fractional
  derivative with Mittag-Leffler nonsingular kernel

abstract:
  In this manuscript we define the right fractional derivative and its
corresponding right fractional integral for the recently introduced nonlocal
fractional derivative with Mittag-Leffler kernel. Then, we obtain the related
integration by parts formula. We use the $Q-$operator to confirm our results.
The corresponding Euler-Lagrange equations are obtained and one illustrative
example is discussed.


title: Relative Entropy and Torsion Coupling

abstract:
  We evaluate the relative entropy on a ball region near the UV fixed point of
a holographic conformal field theory deformed by a fermionic operator of
nonzero vacuum expectation value. The positivity of the relative entropy
considered here is implied by the expected monotonicity of decrease of quantum
entanglement under RG flow. The calculations are done in the perturbative
framework of Einstein-Cartan gravity in four-dimensional asymptotic anti-de
Sitter space with a postulated standard bilinear coupling between axial fermion
current and torsion. By requiring positivity of relative entropy, our result
yields a constraint on axial current-torsion coupling, fermion mass and
equation of state.


title: Validity proof of Lazard's method for CAD construction

abstract:
  In 1994 Lazard proposed an improved method for cylindrical algebraic
decomposition (CAD). The method comprised a simplified projection operation
together with a generalized cell lifting (that is, stack construction)
technique. For the proof of the method's validity Lazard introduced a new
notion of valuation of a multivariate polynomial at a point. However a gap in
one of the key supporting results for his proof was subsequently noticed. In
the present paper we provide a complete validity proof of Lazard's method. Our
proof is based on the classical parametrized version of Puiseux's theorem and
basic properties of Lazard's valuation. This result is significant because
Lazard's method can be applied to any finite family of polynomials, without any
assumption on the system of coordinates. It therefore has wider applicability
and may be more efficient than other projection and lifting schemes for CAD.


title: On the nature of quiescent light curves demonstrated by WZ Sge stars

abstract:
  We present the results of simultaneous spectroscopic and photometric
observations of the cataclysmic variable star (hereafter CVs) V455 Andromedae,
belonging to the WZ Sge sub-class, in quiescence. Using the spectroscopic data
we computed time-resolved Doppler tomograms of the system demonstrating its
behavior at different orbital phases. In the tomograms one can see the periodic
brightening of different regions within one orbital cycle. We interpret this
brightening as being due to the interaction of four phase-locked shock waves in
the disk with a specific internal precessing density wave that develops inside
the disk, because of the tidal influence of the secondary star, and this
density wave propagates up to the disk's outer regions. When the outer part of
the density wave in its precessional motion reaches a shock wave the local
density grows, which amplifies the shock (by increasing $\rho V^{2}/2$). This
results in an additional energy release in the shock and can be observed as a
brightening. Analysis of the tomographic results and the photometric data shows
that two main sources contribute to the light curves of the system: the
radiation of the "hot line" and the bow-shock gives us two major orbital humps,
located approximately at the orbital phases $\phi=0.25$ and $\phi=0.75$; the
amplification of the four shock waves may give us up to four "superhumps"
shifting over the light curve with the precessional period. These two effects,
when overlapping, change the shape of the light curves, shift the hump maxima,
and they sometimes produce more than two humps in the light curve. We should
emphasize that when saying "superhumps" we imply an effect that is observed in
quiescent light curves of WZ Sge stars, as opposed to "classical" superhumps
usually observed in outbursts.


title: The Art of DNA Strings: Sixteen Years of DNA Coding Theory

abstract:
  The idea of computing with DNA was given by Tom Head in 1987, however in 1994
in a seminal paper, the actual successful experiment for DNA computing was
performed by Adleman. The heart of the DNA computing is the DNA hybridization,
however, it is also the source of errors. Thus the success of the DNA computing
depends on the error control techniques. The classical coding theory techniques
have provided foundation for the current information and communication
technology (ICT). Thus it is natural to expect that coding theory will be the
foundational subject for the DNA computing paradigm. For the successful
experiments with DNA computing usually we design DNA strings which are
sufficiently dissimilar. This leads to the construction of a large set of DNA
strings which satisfy certain combinatorial and thermodynamic constraints. Over
the last 16 years, many approaches such as combinatorial, algebraic,
computational have been used to construct such DNA strings. In this work, we
survey this interesting area of DNA coding theory by providing key ideas of the
area and current known results.


title:
Automated 5-year Mortality Prediction using Deep Learning and Radiomics
  Features from Chest Computed Tomography

abstract:
  We propose new methods for the prediction of 5-year mortality in elderly
individuals using chest computed tomography (CT). The methods consist of a
classifier that performs this prediction using a set of features extracted from
the CT image and segmentation maps of multiple anatomic structures. We explore
two approaches: 1) a unified framework based on deep learning, where features
and classifier are automatically learned in a single optimisation process; and
2) a multi-stage framework based on the design and selection/extraction of
hand-crafted radiomics features, followed by the classifier learning process.
Experimental results, based on a dataset of 48 annotated chest CTs, show that
the deep learning model produces a mean 5-year mortality prediction accuracy of
68.5%, while radiomics produces a mean accuracy that varies between 56% to 66%
(depending on the feature selection/extraction method and classifier). The
successful development of the proposed models has the potential to make a
profound impact in preventive and personalised healthcare.


title: Well-posedness for mean-field evolutions arising in superconductivity

abstract:
  We establish the existence of a global solution for a new family of
fluid-like equations, which are obtained in a joint work with Serfaty in
certain regimes as the mean-field evolution of the supercurrent density in a
(2D section of a) type-II superconductor with pinning and with imposed electric
current. We also consider general vortex-sheet initial data, and investigate
the uniqueness and regularity properties of the solution. For some choice of
parameters, the equation under investigation coincides with the so-called lake
equation from 2D shallow water fluid dynamics, and our analysis then leads to a
new existence result for rough initial data.


title:
Does Your DNS Recursion Really Time Out as Intended? A Timeout
  Vulnerability of DNS Recursive Servers

abstract:
  Parallelization is featured by DNS recursive servers to do time-consuming
recursions on behalf on clients. As common DNS configurations, recursive
servers should allow a reasonable timeout for each recursion which may take as
long as several seconds. However, it is proposed in this paper that recursion
parallelization may be exploited by attackers to compromise the recursion
timeout mechanism for the purpose of DoS or DDoS attacks. Attackers can have
recursive servers drop early existing recursions in service by saturating
recursion parallelization. The key of the proposed attack model is to reliably
prolong service times for any attacking queries. As means of prolong service
times, serval techniques are proposed to effectively avoiding cache hit and
prolonging overall latency of external DNS lookups respectively. The impacts of
saturated recursion parallelization on timeout are analytically provided. The
testing on BIND servers demonstrates that with carefully crafted queries, an
attacker can use a low or moderate level of query load to successfully
overwhelm a target recursive server from serving the legitimate clients.


title:
Constraining the dark energy equation of state using Bayes theorem and
  the Kullback-Leibler divergence

abstract:
  Data-driven model-independent reconstructions of the dark energy equation of
state $w(z)$ are presented using Planck 2015 era CMB, BAO, SNIa and
Lyman-$\alpha$ data. These reconstructions identify the $w(z)$ behaviour
supported by the data and show a bifurcation of the equation of state posterior
in the range $1.5{<}z{<}3$. Although the concordance $\Lambda$CDM model is
consistent with the data at all redshifts in one of the bifurcated spaces, in
the other a supernegative equation of state (also known as `phantom dark
energy') is identified within the $1.5 \sigma$ confidence intervals of the
posterior distribution. To identify the power of different datasets in
constraining the dark energy equation of state, we use a novel formulation of
the Kullback--Leibler divergence. This formalism quantifies the information the
data add when moving from priors to posteriors for each possible dataset
combination. The SNIa and BAO datasets are shown to provide much more
constraining power in comparison to the Lyman-$\alpha$ datasets. Further, SNIa
and BAO constrain most strongly around redshift range $0.1-0.5$, whilst the
Lyman-$\alpha$ data constrains weakly over a broader range. We do not attribute
the supernegative favouring to any particular dataset, and note that the
$\Lambda$CDM model was favoured at more than $2$ log-units in Bayes factors
over all the models tested despite the weakly preferred $w(z)$ structure in the
data.


title:
A cluster realization of $U_q(\mathfrak{sl_n})$ from quantum character
  varieties

abstract:
  We construct an injective algebra homomorphism of the quantum group
$U_q(\mathfrak{sl}_{n+1})$ into a quantum cluster algebra $\mathbf{L}_n$
associated to the moduli space of framed $PGL_{n+1}$-local systems on a marked
punctured disk. We obtain a description of the coproduct of
$U_q(\mathfrak{sl}_{n+1})$ in terms of the corresponding quantum cluster
algebra associated to the marked twice punctured disk, and express the action
of the $R$-matrix in terms of a mapping class group element corresponding to
the half-Dehn twist rotating one puncture about the other. As a consequence, we
realize the algebra automorphism of $U_q(\mathfrak{sl}_{n+1})^{\otimes 2}$
given by conjugation by the $R$-matrix as an explicit sequence of cluster
mutations, and derive a refined factorization of the $R$-matrix into quantum
dilogarithms of cluster monomials.


title:
Connections between centrifugal, stratorotational and radiative
  instabilities in viscous Taylor-Couette flow

abstract:
  The `Rayleigh line' $\mu=\eta^2$, where $\mu=\Omega_o/\Omega_i$ and
$\eta=r_i/r_o$ are respectively the rotation and radius ratios between inner
(subscript `i') and outer (subscript `o') cylinders, is regarded as marking the
limit of centrifugal instability (CI) in unstratified inviscid Taylor-Couette
flow, for both axisymmetric and non-axisymmetric modes. Non-axisymmetric
stratorotational instability (SRI) is known to set in for anticyclonic rotation
ratios beyond that line, i.e. $\eta^2<\mu<1$ for axially stably-stratified
Taylor-Couette flow, but the competition between CI and SRI in the range
$\mu<\eta^2$ has not yet been addressed. In this paper, we establish continuous
connections between the two instabilities at finite Reynolds number Re, as
previously suggested by M. Le Bars & P. Le Gal, Phys. Rev. Lett. 99, 064502
(2007), making them indistinguishable at onset. Both instabilities are also
continuously connected to the radiative instability at finite Re. These results
demonstrate the complex impact viscosity has on the linear stability properties
of this flow. Several other qualitative differences with inviscid theory were
found, among which the instability of a non-axisymmetric mode localized at the
outer cylinder without stratification, and the instability of a mode
propagating against the inner cylinder rotation with stratification. The
combination of viscosity and stratification can also lead to a `collision'
between (axisymmetric) Taylor vortex branches, causing the axisymmetric
oscillatory state already observed in past experiments. Perhaps more surprising
is the instability of a centrifugal-like helical mode beyond the Rayleigh line,
caused by the joint effects of stratification and viscosity. The threshold
$\mu=\eta^2$ seems to remain, however, an impassable instability limit for
axisymmetric modes, regardless of stratification, viscosity, and even
disturbance amplitude.


title: Noise Models in Feature-based Stereo Visual Odometry

abstract:
  Feature-based visual structure and motion reconstruction pipelines, common in
visual odometry and large-scale reconstruction from photos, use the location of
corresponding features in different images to determine the 3D structure of the
scene, as well as the camera parameters associated with each image. The noise
model, which defines the likelihood of the location of each feature in each
image, is a key factor in the accuracy of such pipelines, alongside
optimization strategy. Many different noise models have been proposed in the
literature; in this paper we investigate the performance of several. We
evaluate these models specifically w.r.t. stereo visual odometry, as this task
is both simple (camera intrinsics are constant and known; geometry can be
initialized reliably) and has datasets with ground truth readily available
(KITTI Odometry and New Tsukuba Stereo Dataset). Our evaluation shows that
noise models which are more adaptable to the varying nature of noise generally
perform better.


title:
A new analytical approach to consistency and overfitting in regularized
  empirical risk minimization

abstract:
  This work considers the problem of binary classification: given training data
$x_1, \dots, x_n$ from a certain population, together with associated labels
$y_1,\dots, y_n \in \left\{0,1 \right\}$, determine the best label for an
element $x$ not among the training data. More specifically, this work considers
a variant of the regularized empirical risk functional which is defined
intrinsically to the observed data and does not depend on the underlying
population. Tools from modern analysis are used to obtain a concise proof of
asymptotic consistency as regularization parameters are taken to zero at rates
related to the size of the sample. These analytical tools give a new framework
for understanding overfitting and underfitting, and rigorously connect the
notion of overfitting with a loss of compactness.


title: The Sivers asymmetry in $J/\Psi$ and lepton pair production at COMPASS

abstract:
  The abundant production of lepton pairs via $J/\Psi$ creation at COMPASS,
$\pi ^\pm \, p^\uparrow \to J/\Psi \, X \to \ell^+ \ell^- X$, allows a
measurement of the transverse Single Spin Asymmetry generated by the Sivers
effect. The crucial issue of the sign change of the Sivers function in lepton
pair production, with respect to Semi Inclusive Deep Inelastic Scattering
processes, can be solved. Predictions for the expected magnitude of the Single
Spin Asymmetry, which turns out to be large, are given.


title: Analysis of Chromosome 20 - A Study

abstract:
  Since the arrival of next-generation sequencing technologies the amount of
genetic sequencing data has increased dramatically. This has has fueled an
increase in human genetics research. At the same time, with the recent advent
of technologies in processing large data sets, lot of these technologies are
proving valuable and efficient in analyzing these huge datasets. In this paper
we use some of these technologies to analyze genetic sequencing data of 1000
Genomes Project,produce and evaluate a framework to process the sequencing data
thereof and look into structural variations with respect to population groups.


title: Wavefront Sensing in Space from the PICTURE-B Sounding Rocket

abstract:
  A NASA sounding rocket for high contrast imaging with a visible nulling
coronagraph, the Planet Imaging Coronagraphic Technology Using a Reconfigurable
Experimental Base (PICTURE-B) payload has made two suborbital attempts to
observe the warm dust disk inferred around Epsilon Eridani. We present results
from the November 2015 launch demonstrating active wavefront sensing in space
with a piezoelectric mirror stage and a micromachine deformable mirror along
with precision pointing and lightweight optics in space.


title: Obstructing Visibilities with One Obstacle

abstract:
  Obstacle representations of graphs have been investigated quite intensely
over the last few years. We focus on graphs that can be represented by a single
obstacle. Given a (topologically open) polygon $C$ and a finite set $P$ of
points in general position in the complement of $C$, the visibility graph
$G_C(P)$ has a vertex for each point in $P$ and an edge $pq$ for any two points
$p$ and $q$ in $P$ that can see each other, that is, $\overline{pq} \cap
C=\emptyset$. We draw $G_C(P)$ straight-line. Given a graph $G$, we want to
compute an obstacle representation of $G$, that is, an obstacle $C$ and a set
of points $P$ such that $G=G_C(P)$. The complexity of this problem is open,
even for the case that the points are exactly the vertices of a simple polygon
and the obstacle is the complement of the polygon-the simple-polygon visibility
graph problem. There are two types of obstacles; an inside obstacle lies in a
bounded component of the complement of the visibility drawing, whereas an
outside obstacle lies in the unbounded component.
  We show that the class of graphs with an inside-obstacle representation is
incomparable with the class of graphs that have an outside-obstacle
representation. We further show that any graph with at most seven vertices or
circumference at most 6 has an outside-obstacle representation, which does not
hold for a specific graph with 8 vertices and circumference 8. Finally, we
consider the outside-obstacle graph sandwich problem: given graphs $G$ and $H$
on the same vertex set, is there a graph $K$ such that $G \subseteq K \subseteq
H$ and $K$ has an outside-obstacle representation? We show that this problem is
NP-hard even for co-bipartite graphs. With slight modifications, our proof also
shows that the inside-obstacle graph sandwich problem, the single-obstacle
graph sandwich problem, and the simple-polygon visibility graph sandwich
problem are all NP-hard.


title:
Meaningful Models: Utilizing Conceptual Structure to Improve Machine
  Learning Interpretability

abstract:
  The last decade has seen huge progress in the development of advanced machine
learning models; however, those models are powerless unless human users can
interpret them. Here we show how the mind's construction of concepts and
meaning can be used to create more interpretable machine learning models. By
proposing a novel method of classifying concepts, in terms of 'form' and
'function', we elucidate the nature of meaning and offer proposals to improve
model understandability. As machine learning begins to permeate daily life,
interpretable models may serve as a bridge between domain-expert authors and
non-expert users.


title: Solution of deformed Einstein equations and quantum black holes

abstract:
  Recently one and two-parameter deformed Einstein equations have been studied
for extremal quantum black holes which have been proposed to obey deformed
statistics by Strominger. In this study, we give a deeper insight to the
deformed Einstein equations and consider the solutions of these equations for
the extremal quantum black holes. We then represent the implications of the
solutions, such that the deformation parameters lead the charged black holes to
have a smaller mass than the usual Reissner-Nordstr\"om black holes. This
reduction in mass of a usual black hole can be considered as a transition from
classical to quantum black hole regime.


title: The System of Molecular Clouds in the Gould Belt

abstract:
  Based on high-latitude molecular clouds with highly accurate distance
estimates taken from the literature, we have redetermined the parameters of
their spatial orientation. This system can be approximated by a 350x235x140 pc
ellipsoid inclined by the angle i=17+/-2 degrees to the Galactic plane with the
longitude of the ascending node l{\Omega}=337+/-1 degrees. Based on the radial
velocities of the clouds, we have found their group velocity relative to the
Sun to be (u0,v0,w0) = (10.6,18.2,6.8)+/-(0.9,1.7,1.5) km/s. The trajectory of
the center of the molecular cloud system in the past in a time interval of ~60
Myr has been constructed. Using data on masers associated with low-mass
protostars, we have calculated the space velocities of the molecular complexes
in Orion, Taurus, Perseus, and Ophiuchus. Their motion in the past is shown to
be not random.


title: Clues on the Majorana scale from scalar resonances at the LHC

abstract:
  In order to address the observation of the neutrino oscillations and the
metastability of the Standard Model, we extend the fermion sector with two
right-handed (i.e. sterile) neutrinos, and the scalar sector of the SM with a
real scalar, the Hill field. The latter takes the role of a Majoron and
generates the Majorana masses for the neutrino sector, such that the particle
spectrum features two CP-even scalars $h_1$ and $h_2$, and also two heavy, mass
degenerate neutrinos. When the $h_1$ is identified with the scalar resonance at
~125 GeV and the condition is imposed that the $h_1$ self coupling and its
running vanish at the Planck scale, the scalar mixing and the vacuum
expectation value of the Hill field are fixed by the $h_2$ mass. The $h_2$ can
be searched for at the LHC, and it has prospects of being discovered for the
target integrated luminosities of the HL-LHC and the Future Circular hadron
Collider (FCC-hh) when its mass is on the weak scale. The knowledge of the
$h_2$ mass and its decay properties can yield an insight into its coupling to
the heavy neutrinos, and thus also on the heavy neutrino mass scale. This
yields an interesting connection between potentially detectable heavy scalars
in high-energy proton collisions and the mass scale of the heavy neutrinos that
is testable at the LHC and at future colliders.


title: Excited-state quantum phase transition in the Rabi model

abstract:
  The Rabi model, a two-level atom coupled to a harmonic oscillator, can
undergo a second-order quantum phase transition (QPT) [M. -J. Hwang et al,
Phys. Rev. Lett. 115, 180404 (2015)]. Here we show that the Rabi QPT
accompanies critical behavior in the higher energy excited states, i.e., the
excited-state QPT (ESQPT). We derive analytic expressions for the semiclassical
density of states, which shows a logarithmic divergence at a critical energy
eigenvalue in the broken symmetry (superradiant) phase. Moreover, we find that
the logarithmic singularities in the density of states leads to singularities
in the relevant observables in the system such as photon number and atomic
polarization. We corroborate our analytical semiclassical prediction of the
ESQPT in the Rabi model with its numerically exact quantum mechanical solution.


title:
Frustrated double and single ionization in a two-electron triatomic
  molecule H$^+_3$

abstract:
  Using a semi-classical model, we study the formation of highly excited
neutral fragments during the fragmentation of $\mathrm{H_3^+}$, a two-electron
triatomic molecule, driven by an intense near-IR laser field. To do so, we
first formulate a microcanonical distribution for arbitrary one-electron
triatomic molecules. We then study frustrated double and single ionization in
strongly-driven $\mathrm{H_3^+}$ and compute the kinetic energy release of the
nuclei for these two processes. Moreover, we investigate the dependence of
frustrated ionization on the strength of the laser field as well as on the
geometry of the initial molecular state.


title:
Liquid-grain mixing suppresses droplet spreading and splashing during
  impact

abstract:
  Would a raindrop impacting on a coarse beach behave differently from that
impacting on a desert of fine sand? We study this question by a series of model
experiments, where the packing density of the granular target, the wettability
of individual grains, the grain size, the impacting liquid, and the impact
speed are varied. We find that by increasing the grain size and/or the
wettability of individual grains the maximum droplet spreading undergoes a
transition from a capillary regime towards a viscous regime, and splashing is
suppressed. The liquid-grain mixing is discovered to be the underlying
mechanism. An effective viscosity is defined accordingly to quantitatively
explain the observations.


title:
Quantile Graphical Models: Prediction and Conditional Independence with
  Applications to Systemic Risk

abstract:
  We propose two types of Quantile Graphical Models (QGMs) --- Conditional
Independence Quantile Graphical Models (CIQGMs) and Prediction Quantile
Graphical Models (PQGMs). CIQGMs characterize the conditional independence of
distributions by evaluating the distributional dependence structure at each
quantile index. As such, CIQGMs can be used for validation of the graph
structure in the causal graphical models (\cite{pearl2009causality,
robins1986new, heckman2015causal}). One main advantage of these models is that
we can apply them to large collections of variables driven by non-Gaussian and
non-separable shocks. PQGMs characterize the statistical dependencies through
the graphs of the best linear predictors under asymmetric loss functions. PQGMs
make weaker assumptions than CIQGMs as they allow for misspecification. Because
of QGMs' ability to handle large collections of variables and focus on specific
parts of the distributions, we could apply them to quantify tail
interdependence. The resulting tail risk network can be used for measuring
systemic risk contributions that help make inroads in understanding
international financial contagion and dependence structures of returns under
downside market movements.
  We develop estimation and inference methods for QGMs focusing on the
high-dimensional case, where the number of variables in the graph is large
compared to the number of observations. For CIQGMs, these methods and results
include valid simultaneous choices of penalty functions, uniform rates of
convergence, and confidence regions that are simultaneously valid. We also
derive analogous results for PQGMs, which include new results for penalized
quantile regressions in high-dimensional settings to handle misspecification,
many controls, and a continuum of additional conditioning events.


title:
Pauli Blockade in a Few-Hole PMOS Double Quantum Dot limited by
  Spin-Orbit Interaction

abstract:
  We report on hole compact double quantum dots fabricated using conventional
CMOS technology. We provide evidence of Pauli spin blockade in the few hole
regime which is relevant to spin qubit implementations.
  A current dip is observed around zero magnetic field, in agreement with the
expected behavior for the case of strong spin-orbit. We deduce an intradot spin
relaxation rate $\approx$120\,kHz for the first holes, an important step
towards a robust hole spin-orbit qubit.


title:
Evolution of the dust-to-metals ratio in high-redshift galaxies probed
  by GRB-DLAs

abstract:
  Context. Several issues regarding the nature of dust at high redshift remain
unresolved: its composition, its production and growth mechanisms, and its
effect on background sources. Aims. We provide a more accurate relation between
dust depletion levels and dust-to-metals ratio (DTM), and to use the DTM to
investigate the origin and evolution of dust in the high-redshift Universe via
Gamma-ray burst damped Lyman-alpha absorbers (GRB-DLAs). Methods. We use
absorption-line measured metal column densities for a total of 19 GRB-DLAs,
including five new GRB afterglow spectra from VLT/X-shooter. We use the latest
linear models to calculate the dust depletion strength factor in each DLA.
Using these values we calculate total dust and metal column densities to
determine a DTM. We explore the evolution of DTM with metallicity, and compare
it to previous trends in DTM measured with different methods. Results. We find
significant dust depletion in 16 of our 19 GRB-DLAs, yet 18 of the 19 have a
DTM significantly lower than the Milky Way. We find that DTM is positively
correlated with metallicity, which supports a dominant ISM grain-growth mode of
dust formation. We find a substantial discrepancy between the dust content
measured from depletion and that derived from the total V-band extinction,
$A_V$ , measured by fitting the afterglow SED. We advise against using a
measurement from one method to estimate that from the other until the
discrepancy can be resolved.


title:
Degenerating Hermitian metrics and spectral geometry of the canonical
  bundle

abstract:
  Let $(X,h)$ be a compact and irreducible Hermitian complex space of complex
dimension $m$. In this paper we are interested in the Dolbeault operator acting
on the space of $L^2$ sections of the canonical bundle of $reg(X)$, the regular
part of $X$. More precisely let
$\overline{\mathfrak{d}}_{m,0}:L^2\Omega^{m,0}(reg(X),h)\rightarrow
L^2\Omega^{m,1}(reg(X),h)$ be an arbitrarily fixed closed extension of
$\overline{\partial}_{m,0}:L^2\Omega^{m,0}(reg(X),h)\rightarrow
L^2\Omega^{m,1}(reg(X),h)$ where the domain of the latter operator is
$\Omega_c^{m,0}(reg(X))$. We establish various properties such as closed range
of $\overline{\mathfrak{d}}_{m,0}$, compactness of the inclusion
$\mathcal{D}(\overline{\mathfrak{d}}_{m,0})\hookrightarrow
L^2\Omega^{m,0}(reg(X),h)$ where $\mathcal{D}(\overline{\mathfrak{d}}_{m,0})$,
the domain of $\overline{\mathfrak{d}}_{m,0}$, is endowed with the
corresponding graph norm, and discreteness of the spectrum of the associated
Hodge-Kodaira Laplacian $\overline{\mathfrak{d}}_{m,0}^*\circ
\overline{\mathfrak{d}}_{m,0}$ with an estimate for the growth of its
eigenvalues. Several corollaries such as trace class property for the heat
operator associated to $\overline{\mathfrak{d}}_{m,0}^*\circ
\overline{\mathfrak{d}}_{m,0}$, with an estimate for its trace, are derived.
Finally in the last part we provide several applications to the Hodge-Kodaira
Laplacian in the setting of both compact irreducible Hermitian complex spaces
with isolated singularities and complex projective surfaces.


title: Implications of gamma-ray observations on proton models of UHECR

abstract:
  The origin of ultra high energy cosmic rays (UHECR) is still unknown.
However, great progress has been achieved in past years due to the good quality
and large statistics in experimental data collected by the current
observatories. The data of the Pierre Auger Observatory show that the
composition of the UHECRs becomes progressively lighter starting from $10^{17}$
eV up to $\sim 10^{18.3}$ eV and then, beyond that energy, it becomes
increasingly heavier. These analyses are subject to important systematic
uncertainties due to the use of hadronic interaction models that extrapolate
lower energy accelerator data to the highest energies. Although proton models
of UHECRs are disfavored by these results, they cannot be completely ruled out.
It is well known that the energy spectra of gamma rays and neutrinos, produced
during propagation of these very energetic particles through the intergalactic
medium, are a useful tool to constrain the spectrum models. In particular, it
has recently been shown that the neutrino upper limits obtained by IceCube
challenge the proton models at 95% CL. In this work we study the constraints
imposed by the extragalactic gamma-ray background, measured by Fermi-LAT, on
proton models of UHECRs. In particular, we make use of the extragalactic
gamma-ray background flux, integrated from 50 GeV to 2 TeV, that originates in
point sources, which has recently been obtained by the Fermi-LAT collaboration,
in combination with the neutrino upper limits, to constrain the emission of
UHECRs at high redshits ($z>1$), in the context of the proton models.


title: High-Performance Tensor Contraction without Transposition

abstract:
  Tensor computations--in particular tensor contraction (TC)--are important
kernels in many scientific computing applications. Due to the fundamental
similarity of TC to matrix multiplication (MM) and to the availability of
optimized implementations such as the BLAS, tensor operations have
traditionally been implemented in terms of BLAS operations, incurring both a
performance and a storage overhead. Instead, we implement TC using the flexible
BLIS framework, which allows for transposition (reshaping) of the tensor to be
fused with internal partitioning and packing operations, requiring no explicit
transposition operations or additional workspace. This implementation, TBLIS,
achieves performance approaching that of MM, and in some cases considerably
higher than that of traditional TC. Our implementation supports multithreading
using an approach identical to that used for MM in BLIS, with similar
performance characteristics. The complexity of managing tensor-to-matrix
transformations is also handled automatically in our approach, greatly
simplifying its use in scientific applications.


title: Bayes factor consistency

abstract:
  Good large sample performance is typically a minimum requirement of any model
selection criterion. This article focuses on the consistency property of the
Bayes factor, a commonly used model comparison tool, which has experienced a
recent surge of attention in the literature. We thoroughly review existing
results. As there exists such a wide variety of settings to be considered, e.g.
parametric vs. nonparametric, nested vs. non-nested, etc., we adopt the view
that a unified framework has didactic value. Using the basic marginal
likelihood identity of Chib (1995), we study Bayes factor asymptotics by
decomposing the natural logarithm of the ratio of marginal likelihoods into
three components. These are, respectively, log ratios of likelihoods, prior
densities, and posterior densities. This yields an interpretation of the log
ratio of posteriors as a penalty term, and emphasizes that to understand Bayes
factor consistency, the prior support conditions driving posterior consistency
in each respective model under comparison should be contrasted in terms of the
rates of posterior contraction they imply.


title: Neutrino oscillations at DUNE with improved energy reconstruction

abstract:
  We study the physics reach of the long-baseline oscillation analysis of the
DUNE experiment when realistic simulations are used to estimate its neutrino
energy reconstruction capabilities. Our studies indicate that significant
improvements in energy resolution compared to what is customarily assumed are
plausible. This improved energy resolution can increase the sensitivity to
leptonic CP violation in two ways. On the one hand, the CP-violating term in
the oscillation probability has a characteristic energy dependence that can be
better reproduced. On the other hand, the second oscillation maximum,
especially sensitive to $\delta_{CP}$, is better reconstructed. These effects
lead to a significant improvement in the fraction of values of $\delta_{CP}$
for which a $5 \sigma$ discovery of leptonic CP-violation would be possible.
The precision of the $\delta_{CP}$ measurement could also be greatly enhanced,
with a reduction of the maximum uncertainties from $26^\circ$ to $18^\circ$ for
a 300~MW$\cdot$kt$\cdot$yr exposure. We therefore believe that this potential
gain in physics reach merits further investigations of the detector performance
achievable in DUNE.


title: Testing Lorentz symmetry with Lunar Laser Ranging

abstract:
  Lorentz symmetry violations can be parametrized by an effective field theory
framework that contains both general relativity and the standard model of
particle physics called the standard-model extension (SME). We present new
constraints on pure gravity SME coefficients obtained by analyzing lunar laser
ranging (LLR) observations. We use a new numerical lunar ephemeris computed in
the SME framework and we perform a LLR data analysis using a set of 20721
normal points covering the period of August, 1969 to December, 2013. We
emphasize that linear combination of SME coefficients to which LLR data are
sensitive and not the same as those fitted in previous postfit residuals
analysis using LLR observations and based on theoretical grounds. We found no
evidence for Lorentz violation at the level of $10^{-8}$ for $\bar{s}^{TX}$,
$10^{-12}$ for $\bar{s}^{XY}$ and $\bar{s}^{XZ}$, $10^{-11}$ for
$\bar{s}^{XX}-\bar{s}^{YY}$ and
$\bar{s}^{XX}+\bar{s}^{YY}-2\bar{s}^{ZZ}-4.5\bar{s}^{YZ}$ and $10^{-9}$ for
$\bar{s}^{TY}+0.43\bar{s}^{TZ}$. We improve previous constraints on SME
coefficient by a factor up to 5 and 800 compared to postfit residuals analysis
of respectively binary pulsars and LLR observations.


title:
Studies on charge production from Cs2Te photocathodes in the PITZ L-band
  normal conducting radio frequency photo injector

abstract:
  This paper discusses the behavior of electron bunch charge produced in an
L-band normal conducting radio frequency cavity (RF gun) from Cs2Te
photocathodes illuminated with ps-long UV laser pulses when the laser
transverse distribution consists of a flat-top core with Gaussian-like decaying
halo. The produced charge shows a linear dependence at low laser pulse energies
as expected in the quantum efficiency limited emission regime, while its
dependence on laser pulse energy is observed to be much weaker for higher
values, due to space charge limited emission. However, direct plug-in of
experimental parameters into the space charge tracking code ASTRA yields lower
output charge in the space charge limited regime compared to measured values.
The rate of increase of the produced charge at high laser pulse energies close
to the space charge limited emission regime seems to be proportional to the
amount of halo present in the radial laser profile since the charge from the
core has saturated already. By utilizing core + halo particle distributions
based on measured radial laser profiles, ASTRA simulations and semi-analytical
emission models reproduce the behavior of the measured charge for a wide range
of RF gun and laser operational parameters within the measurement
uncertainties.


title:
Charge-exchange, ionization and excitation in low-energy Li$^{+}-$ Ar,
  K$^{+}-$ Ar, and Na$^{+}-$He collisions

abstract:
  Absolute cross sections are measured for charge-exchange, ionization, and
excitation within the same experimental setup for the Li$^{+}-$Ar, K$^{+}-$ Ar,
and Na$^{+}-$ He collisions in the ion energy range $0.5-10$ keV. Results of
our measurements along with existing experimental data and the schematic
correlation diagrams are used to analyze and determine the mechanisms for these
processes. The experimental results show that the charge-exchange processes are
realized with high probabilities and electrons are predominately captured in
ground states. The cross section ratio for charge exchange, ionization and
excitation processes roughly attains the value $10:2:1$, respectively. The
contributions of various partial inelastic channels to the total ionization
cross sections are estimated and a primary mechanism for the process is
defined. The energy-loss spectrum, in addition, is applied to estimate the
relative contribution of different inelastic channels and to determine the
mechanisms for the ionization and for some excitation processes of Ar resonance
lines for the K$^{+}-$Ar collision system. The excitation function for the
helium, as well as for the sodium doublet lines for the Na$^{+}-$He collision
system, reveals some unexpected features and a mechanism to explain this
observation is suggested.


title: Characterizing Corson and Valdivia compact spaces

abstract:
  We give a new characterization of Valdivia compact spaces: A compact space is
Valdivia if and only if it has a dense commutatively monotonically retractable
subspace. This result solves Problem 5.12 from \cite{sal-rey}. Besides, we
introduce the notion of full $c$-skeleton and prove that a compact space is
Corson if and only if it has a full $c$-skeleton.


title: CLEX: Yet Another Supercomputer Architecture?

abstract:
  We propose the CLEX supercomputer topology and routing scheme. We prove that
CLEX can utilize a constant fraction of the total bandwidth for point-to-point
communication, at delays proportional to the sum of the number of intermediate
hops and the maximum physical distance between any two nodes. Moreover, %
applying an asymmetric bandwidth assignment to the links, all-to-all
communication can be realized $(1+o(1))$-optimally both with regard to
bandwidth and delays. This is achieved at node degrees of $n^{\varepsilon}$,
for an arbitrary small constant $\varepsilon\in (0,1]$. In contrast, these
results are impossible in any network featuring constant or polylogarithmic
node degrees. Through simulation, we assess the benefits of an implementation
of the proposed communication strategy. Our results indicate that, for a
million processors, CLEX can increase bandwidth utilization and reduce average
routing path length by at least factors $10$ respectively $5$ in comparison to
a torus network. Furthermore, the CLEX communication scheme features several
other properties, such as deadlock-freedom, inherent fault-tolerance, and
canonical partition into smaller subsystems.


title: Review of lattice results concerning low-energy particle physics

abstract:
  We review lattice results related to pion, kaon, D- and B-meson physics with
the aim of making them easily accessible to the particle physics community.
More specifically, we report on the determination of the light-quark masses,
the form factor f+(0), arising in the semileptonic K -> pi transition at zero
momentum transfer, as well as the decay constant ratio fK/fpi and its
consequences for the CKM matrix elements Vus and Vud. Furthermore, we describe
the results obtained on the lattice for some of the low-energy constants of
SU(2)LxSU(2)R and SU(3)LxSU(3)R Chiral Perturbation Theory. We review the
determination of the BK parameter of neutral kaon mixing as well as the
additional four B parameters that arise in theories of physics beyond the
Standard Model. The latter quantities are an addition compared to the previous
review. For the heavy-quark sector, we provide results for mc and mb (also new
compared to the previous review), as well as those for D- and B-meson decay
constants, form factors, and mixing parameters. These are the heavy-quark
quantities most relevant for the determination of CKM matrix elements and the
global CKM unitarity-triangle fit. Finally, we review the status of lattice
determinations of the strong coupling constant alpha_s.