title: The NNbar Experiment at the European Spallation Source

abstract:
  The observation of neutron to antineutron oscillation would be the first
experimental evidence to show that baryon number is not a conserved quantity.
It also provides an answer to the hypothesized post-sphaleron baryogenesis
mechanism shortly after the Big Bang. The free oscillation time
{\tau_{n\rightarrow\bar{n}} has a lower limit at 8.7 x 10^7 seconds determined
at ILL in 1994. Current beyond Standard Model theories of this oscillation time
estimate the value to be on the order of 10^{10} seconds. A new experiment is
proposed at the European Spallation Source that has 1000 times the sensitivity
of the previous experiment, and would confirm the viability of those beyond
Standard Model theories.


title: A Hypothesis on Upper Bound of Goldbach Counting Function

abstract:
  I define Goldbach counting function with N > 0 and square-free P > 0.
Decomposition of this function is discovered and deduction formula is found. I
propose a hypothesis on upper bound of Goldbach counting function and prove
that Goldbach conjecture is true under this hypothesis. Also, I propose a
second hypothesis on upper bound of Goldbach counting function and prove that
the twin prime conjecture is true under this hypothesis


title:
Modulation of circular current and associated magnetic field in a
  molecular junction: A new approach

abstract:
  A new proposal is given to control local magnetic field in a molecular
junction. In presence of finite bias a net circular current is established in
the molecular ring which induces a magnetic field at its centre. Allowing a
direct coupling between two electrodes, due to their close proximity, and
changing its strength we can regulate circular current as well as magnetic
field for a wide range, without disturbing any other physical parameters. We
strongly believe that our proposal is quite robust compared to existing
approaches of controlling local magnetic field and can be verified
experimentally.


title:
Damping of parametrically excited magnons in the presence of the
  longitudinal spin Seebeck effect

abstract:
  The impact of the longitudinal spin Seebeck effect (LSSE) on the magnon
damping in magnetic-insulator/nonmagnetic-metal bilayers was recently discussed
in several reports. However, results of those experiments can be blurred by
multimode excitation within the measured linewidth. In order to avoid possible
intermodal interference, we investigated the damping of a single magnon group
in a platinum covered Yttrium Iron Garnet (YIG) film by measurement of the
threshold of its parametric excitation. Both dipolar and exchange spin-wave
branches were probed. It turned out that the LSSE-related modification of
spin-wave damping in a micrometer-thick YIG film is too weak to be observed in
the entire range of experimentally accessible wavevectors. At the same time,
the change in the mean temperature of the YIG layer, which can appear by
applying a temperature gradient, strongly modifies the damping value.


title: Two-particle interference of electron pairs on a molecular level

abstract:
  We investigate the photo-doubleionization of $H_2$ molecules with 400 eV
photons. We find that the emitted electrons do not show any sign of two-center
interference fringes in their angular emission distributions if considered
separately. In contrast, the quasi-particle consisting of both electrons (i.e.
the "dielectron") does. The work highlights the fact that non-local effects are
embedded everywhere in nature where many-particle processes are involved.


title: The quantum group fixing a sequence of finite subsets

abstract:
  Motivated by generalizing Szemer\'edi's theorem, we the elements in a
discrete quantum group fixing a sequence of finite subsets and prove that the
set of these elements is a quantum subgroup. Using this we obtain a version of
mean ergodic theorem for discrete quantum groups.


title: Minimal model for spontaneous quantum synchronization

abstract:
  We show the emergence of spontaneous synchronization between a pair of
detuned quantum oscillators within a harmonic network. Our model does not
involve any nonlinearity, driving, or external dissipation, thus providing the
simplest scenario for the occurrence of local coherent dynamics in an extended
harmonic system. A sufficient condition for synchronization is established by
building upon the Rayleigh normal mode approach to vibrational systems. Our
results show that mechanisms favoring synchronization, even between oscillators
that are not directly coupled to each other, are transient energy depletion and
crosstalk. We also address the possible buildup of quantum correlations during
synchronization and show that indeed entanglement may be generated in detuned
systems, starting from uncorrelated states and without any direct coupling
between the two oscillators.


title:
Semi-phenomenological classification models of the genetic code(s) using
  q-deformed numbers

abstract:
  The mathematical concept of q-deformations, in particular the one of
qnumbers, is used to study the genetic code(s). After considering two kinds of
q-numbers, for comparison, a phenomenological classification scheme of the
genetic code together with its numerous minor variants is, first, established.
Next, numbers describing the presence of additional amino acids, such as
Selenocysteine or/and Pyrrolysine, are also produced. Finally, a minimal number
of amino acids, which could fit the small number of them which are thought to
have been involved, at the origin of life on Earth, is found. All together,
these results constitute our final semi-phenomenological model.


title:
Forward problem for Love and quasi-Rayleigh waves: Exact dispersion
  relations and their sensitivities

abstract:
  We examine two types of guided waves: the Love and the quasi-Rayleigh waves.
Both waves propagate in the same model of an elastic isotropic layer above an
elastic isotropic halfspace. From their dispersion relations, we calculate
their speeds as functions of the elasticity parameters, mass densities,
frequency and layer thickness. We examine the sensitivity of these relations to
the model and wave properties.


title:
Looijenga's weighted projective space, Tate's algorithm and Mordell-Weil
  Lattice in F-theory and heterotic string theory

abstract:
  It is now well known that the moduli space of a vector bundle for heterotic
string compactifications to four dimensions is parameterized by a set of
sections of a weighted projective space bundle of a particular kind, known as
Looijenga's weighted projective space bundle. We show that the requisite
weighted projective spaces and the Weierstrass equations describing the
spectral covers for gauge groups E_N (N=4,...,8) and SU(n+1) (n=1,2,3) can be
obtained systematically by a series of blowing-up procedures according to
Tate's algorithm, thereby the sections of correct line bundles claimed to arise
by Looijenga's theorem can be automatically obtained. They are nothing but the
four-dimensional analogue of the set of independent polynomials in the
six-dimensional F-theory parameterizing the complex structure, which is further
confirmed in the constructions of D_4, A_5, D_6, E_3 and SU(2) x SU(2) bundles.
We also explain why we can obtain them in this way by using the structure
theorem of the Mordell-Weil lattice, which is also useful for understanding the
relation between the singularity and the occurrence of chiral matter in
F-theory.


title:
Measurement of top quark pair differential cross-sections in the
  dilepton channel in $pp$ collisions at $\sqrt{s}$ = 7 and 8 TeV with ATLAS

abstract:
  Measurements of normalized differential cross-sections of top quark pair
($t\bar t$) production are presented as a function of the mass, the transverse
momentum and the rapidity of the $t\bar t$ system in proton-proton collisions
at center-of-mass energies of $\sqrt{s}$ = 7 TeV and 8 TeV. The dataset
corresponds to an integrated luminosity of 4.6 fb$^{-1}$ at 7 TeV and 20.2
fb$^{-1}$ at 8 TeV, recorded with the ATLAS detector at the Large Hadron
Collider. Events with top quark pair signatures are selected in the dilepton
final state, requiring exactly two charged leptons and at least two jets with
at least one of the jets identified as likely to contain a $b$-hadron. The
measured distributions are corrected for detector effects and selection
efficiency to cross-sections at the parton level. The differential
cross-sections are compared with different Monte Carlo generators and
theoretical calculations of $t\bar t$ production. The results are consistent
with the majority of predictions in a wide kinematic range.


title: On the convergence of minimizers of singular perturbation functionals

abstract:
  The study of singular perturbations of the Dirichlet energy is at the core of
the phenomenological-description paradigm in soft condensed matter. Being able
to pass to the limit plays a crucial role in the understanding of the
geometric-driven profile of ground states. In this work we study, under very
general assumptions, the convergence of minimizers towards harmonic maps. We
show that the convergence is locally uniform up to the boundary, away from the
lower dimensional singular set. Our results generalize related findings, most
notably in the theory of liquid-crystals, to all dimensions $n\geq 3$, and to
general nonlinearities. Our proof follows a well-known scheme, relying on small
energy estimate and monotonicity formula. It departs substantially from
previous studies in the treatment of the small energy estimate at the boundary,
since we do not rely on the specific form of the potential. In particular this
extends existing results in 3-dimensional settings. In higher dimensions we
also deal with additional difficulties concerning the boundary monotonicity
formula.


title:
A minimum principle for potentials with application to Chebyshev
  constants

abstract:
  For "Riesz-like" kernels $K(x,y)=f(|x-y|)$ on $A\times A$, where $A$ is a
compact $d$-regular set $A\subset \mathbb{R}^p$, we prove a minimum principle
for potentials $U_K^\mu=\int K(x,y)d\mu(x)$, where $\mu$ is a Borel measure
supported on $A$. Setting $P_K(\mu)=\inf_{y\in A}U^\mu(y)$, the
$K$-polarization of $\mu$, the principle is used to show that if $\{\nu_N\}$ is
a sequence of measures on $A$ that converges in the weak-star sense to the
measure $\nu$, then $P_K(\nu_N)\to P_K(\nu)$ as $N\to \infty$. The continuous
Chebyshev (polarization) problem concerns maximizing $P_K(\mu)$ over all
probability measures $\mu$ supported on $A$, while the $N$-point discrete
Chebyshev problem maximizes $P_K(\mu)$ only over normalized counting measures
for $N$-point multisets on $A$. We prove for such kernels and sets $A$, that if
$\{\nu_N\}$ is a sequence of $N$-point measures solving the discrete problem,
then every weak-star limit measure of $\nu_N$ as $N \to \infty$ is a solution
to the continuous problem.


title:
Students' patterns of interaction with a mathematics intelligent tutor:
  Learning analytics application

abstract:
  The purpose of this paper is to determine potential identifiers of students'
academic success in foundation mathematics course from the data logs of an
intelligent tutor. A cross-sectional study design was used. A sample of 58
records was extracted from the data-logs of an intelligent tutor, Assessment
for Learning using Knowledge Spaces (ALEKS). This data was triangulated with
the data collected from surveys. Two-step clustering, regression analysis,
paired-sample t-tests were applied to address the research questions. The
data-logs of ALEKS include information about number of topics practiced and
number of topics mastered. A derived attribute, which is the ratio of number of
topics mastered to number of topics practiced is found to be a predictor of
final marks. Students' prior knowledge and this derived attribute are
predictors of final grades with R square=42%. Students were asked to report
their preferred way of selecting topics as either sequential or random. Results
of paired sample t-test demonstrated that the students who selected topics in
sequential manner were able to retain their mastery of learning after the
summative assessment whereas the students who chose topics randomly were not
able to retain their mastery of learning.


title:
A general forcefield for accurate phonon properties of metal-organic
  frameworks

abstract:
  We report the development of a forcefield capable of reproducing accurate
lattice dynamics of metal-organic frameworks. Phonon spectra, thermodynamic and
mechanical properties, such as free energies, heat capacities and bulk moduli,
are calculated using the quasi-harmonic approximation to account for anharmonic
behaviour due to thermal expansion. Comparison to density functional theory
calculations of properties such as Gr$\mathrm{\ddot{u}}$neisen parameters, bulk
moduli and thermal expansion supports the accuracy of the derived forcefield
model. Material properties are also reported in a full analysis of the lattice
dynamics of an initial subset of structures including: MOF-5, IRMOF-10, UiO-66,
UiO-67, NOTT-300, MIL-125, MOF-74 and MOF-650.


title: Session Types for Link Failures (Technical Report)

abstract:
  We strive to use session type technology to prove behavioural properties of
fault-tolerant distributed algorithms. Session types are designed to abstractly
capture the structure of (even multi-party) communication protocols. The goal
of session types is the analysis and verification of the protocols' behavioural
properties. One important such property is progress, i.e., the absence of
(unintended) deadlock. Distributed algorithms often resemble (compositions of)
multi-party communication protocols. In contrast to protocols that are
typically studied with session types, they are often designed to cope with
system failures. An essential behavioural property is (successful) termination,
despite failures, but it is often elaborate to prove for distributed
algorithms.
  We extend multi-party session types (and multi-party session types with
nested sessions) by optional blocks that cover a limited class of link and
crash failures. This allows us to automatically derive termination of
distributed algorithms that come within these limits. To illustrate our
approach, we prove termination for an implementation of the *rotating
coordinator* Consensus algorithm.


title: Jarzynski equality in the context of maximum path entropy

abstract:
  In the global framework of finding an axiomatic derivation of nonequilibrium
Statistical Mechanics from fundamental principles, such as the maximum path
entropy -- also known as Maximum Caliber principle -- , this work proposes an
alternative derivation of the well-known Jarzynski equality, a nonequilibrium
identity of great importance today due to its applications to irreversible
processes: biological systems (protein folding), mechanical systems, among
others. This equality relates the free energy differences between two
equilibrium thermodynamic states with the work performed when going between
those states, through an average over a path ensemble.
  In this work the analysis of Jarzynski's equality will be performed using the
formalism of inference over path space. This derivation highlights the wide
generality of Jarzynski's original result, which could even be used in
non-thermodynamical settings such as social systems, financial and ecological
systems.


title: Validation of Information Fusion

abstract:
  We motivate and offer a formal definition of validation as it applies to
information fusion systems. Common definitions of validation compare the actual
state of the world with that derived by the fusion process. This definition
conflates properties of the fusion system with properties of systems that
intervene between the world and the fusion system. We propose an alternative
definition where validation of an information fusion system references a
standard fusion device, such as recognized human experts. We illustrate the
approach by describing the validation process implemented in RAID, a program
conducted by DARPA and focused on information fusion in adversarial, deceptive
environments.


title: Angular dynamics of small crystals in viscous flow

abstract:
  The angular dynamics of a very small ellipsoidal particle in a viscous flow
decouples from its translational dynamics, and the particle angular velocity is
given by Jeffery's theory. It is known that cuboid particles share these
properties. In the literature a special case is most frequently discussed,
namely that of axisymmetric particles with a continuous rotation symmetry. Here
we compute the angular dynamics of crystals that possess a discrete rotation
symmetry and certain mirror symmetries, but that do not have a continuous
rotation symmetry. We give examples of such particles that nevertheless obey
Jeffery's theory. But there are other examples where the angular dynamics is
determined by a more general equation of motion.


title: Scaling Description of Non-Local Rheology

abstract:
  Non-locality is crucial to understand the plastic flow of an amorphous
material, and has been successfully described by the fluidity, along with a
cooperativity length scale {\xi}. We demonstrate, by applying the scaling
hypothesis to the yielding transition, that non-local effects in non-uniform
stress configurations can be explained within the framework of critical
phenomena. From the scaling description, scaling relations between different
exponents are derived, and collapses of strain rate profiles are made both in
shear driven and pressure driven flow. We find that the cooperative length in
non-local flow is governed by the same correlation length in finite dimensional
homogeneous flow, excluding the mean field exponents. We also show that
non-locality also affects the finite size scaling of the yield stress,
especially the large finite size effects observed in pressure driven flow. Our
theoretical results are nicely verified by the elasto-plastic model, and
experimental data.


title: Noetherian Quasi-Polish Spaces

abstract:
  In the presence of suitable power spaces, compactness of $\mathbf{X}$ can be
characterized as the singleton $\{X\}$ being open in the space
$\mathcal{O}(\mathbf{X})$ of open subsets of $\mathbf{X}$. Equivalently, this
means that universal quantification over a compact space preserves open
predicates.
  Using the language of represented spaces, one can make sense of notions such
as a $\Sigma^0_2$-subset of the space of $\Sigma^0_2$-subsets of a given space.
This suggests higher-order analogues to compactness: We can, e.g.~, investigate
the spaces $\mathbf{X}$ where $\{X\}$ is a $\Delta^0_2$-subset of the space of
$\Delta^0_2$-subsets of $\mathbf{X}$. Call this notion $\nabla$-compactness. As
$\Delta^0_2$ is self-dual, we find that both universal and existential
quantifier over $\nabla$-compact spaces preserve $\Delta^0_2$ predicates.
  Recall that a space is called Noetherian iff every subset is compact. Within
the setting of Quasi-Polish spaces, we can fully characterize the
$\nabla$-compact spaces: A Quasi-Polish space is Noetherian iff it is
$\nabla$-compact. Note that the restriction to Quasi-Polish spaces is
sufficiently general to include plenty of examples.


title:
On accurate differential measurements with electrochemical impedance
  spectroscopy

abstract:
  This paper describes the impedance spectroscopy adapted for analysis of small
electrochemical changes in fluids. To increase accuracy of measurements the
differential approach with temperature stabilization of fluid samples and
electronics is used. The impedance analysis is performed by the single point
DFT, signal correlation, calculation of RMS amplitudes and interference phase
shift. For test purposes the samples of liquids and colloids are treated by
fully shielded electromagnetic generators and passive cone-shaped structures.
Fluidic samples collected from different geological locations are also
analysed. In all tested cases we obtained different results for impacted and
non-impacted samples, moreover, a degradation of electrochemical stability
after treatment is observed. This method is used in laboratory analysis of weak
emissions and ensures a high repeatability of results.


title: Searches for exotic interactions with the nEDM experiment

abstract:
  Ultracold neutrons were used to search for signals indicating the violation
of Lorentz and CPT invariance or the existence of dark matter using the
spectrometer to search for an electric dipole moment of the neutron.


title: The fate of alpha dynamos at large $Rm$

abstract:
  At the heart of today's solar magnetic field evolution models lies the alpha
dynamo description. In this work, we investigate the fate of alpha-dynamos as
the magnetic Reynolds number $Rm$ is increased. Using Floquet theory, we are
able to precisely quantify mean field effects like the alpha and beta effect
(i) by rigorously distinguishing dynamo modes that involve large scale
components from the ones that only involve small scales, and by (ii) providing
a way to investigate arbitrary large scale separations with minimal
computational cost. We apply this framework to helical and non-helical flows as
well as to random flows with short correlation time. Our results determine that
the alpha-description is valid for $Rm$ smaller than a critical value $Rm_c$ at
which small scale dynamo instability starts. When $Rm$ is above $Rm_c$ the
dynamo ceases to follow the mean field description and the growth rate of the
large scale modes becomes independent of the scale separation while the energy
in the large scale modes is inversely proportional to the square of the scale
separation. The results in this second regime do not depend on the presence of
helicity. Thus alpha-type modeling for solar and stellar models needs to be
reevaluated and new directions for mean field modeling are proposed.


title: Learning Aligned Cross-Modal Representations from Weakly Aligned Data

abstract:
  People can recognize scenes across many different modalities beyond natural
images. In this paper, we investigate how to learn cross-modal scene
representations that transfer across modalities. To study this problem, we
introduce a new cross-modal scene dataset. While convolutional neural networks
can categorize cross-modal scenes well, they also learn an intermediate
representation not aligned across modalities, which is undesirable for
cross-modal transfer applications. We present methods to regularize cross-modal
convolutional neural networks so that they have a shared representation that is
agnostic of the modality. Our experiments suggest that our scene representation
can help transfer representations across modalities for retrieval. Moreover,
our visualizations suggest that units emerge in the shared representation that
tend to activate on consistent concepts independently of the modality.


title: Matter density perturbation and power spectrum in running vacuum model

abstract:
  We investigate the matter density perturbation $\delta_m$ and power spectrum
$P(k)$ in the running vacuum model (RVM) with the cosmological constant being a
function of the Hubble parameter, given by $\Lambda = \Lambda_0 + 6 \sigma H
H_0+ 3\nu H^2$, in which the linear and quadratic terms of $H$ would originate
from the QCD vacuum condensation and cosmological renormalization group,
respectively. Taking the dark energy perturbation into consideration, we derive
the evolution equation for $\delta_m$ and find a specific scale $d_{cr}=2
\pi/k_{cr}$, which divides the evolution of the universe into the sub and
super-interaction regimes, corresponding to $k \ll k_{cr}$ and $k \gg k_{cr}$,
respectively. For the former, the evolution of $\delta_m$ has the same behavior
as that in the $\Lambda$CDM model, while for the latter, the growth of
$\delta_m$ is frozen (greatly enhanced) when $\nu + \sigma >(<)0$ due to the
couplings between radiation, matter and dark energy. It is clear that the
observational data rule out the cases with $\nu<0$ and $\nu + \sigma <0$, while
the allowed window for the model parameters is extremely narrow with $\nu,
|\sigma| \lesssim \mathcal{O}(10^{-7})$.


title:
Automated quantification of one-dimensional nanostructure alignment on
  surfaces

abstract:
  A method for automated quantification of the alignment of one-dimensional
nanostructures from microscopy imaging is presented. Nanostructure alignment
metrics are formulated and shown to able to rigorously quantify the
orientational order of nanostructures within a two-dimensional domain
(surface). A complementary image processing method is also presented which
enables robust processing of microscopy images where overlapping nanostructures
might be present. Scanning electron microscopy (SEM) images of nanowire-covered
surfaces are analyzed using the presented methods and it is shown that past
single parameter alignment metrics are insufficient for highly aligned domains.
Through the use of multiple parameter alignment metrics, automated quantitative
analysis of SEM images is shown to be possible and the alignment
characteristics of different samples are able to be rigorously compared using a
similarity metric. The results of this work provide researchers in nanoscience
and nanotechnology with a rigorous method for the determination of
structure/property relationships where alignment of one-dimensional
nanostructures is significant.


title:
Smart Charging for Electric Vehicles: A Survey From the Algorithmic
  Perspective

abstract:
  Smart interactions among the smart grid, aggregators and EVs can bring
various benefits to all parties involved, e.g., improved reliability and safety
for the smart gird, increased profits for the aggregators, as well as enhanced
self benefit for EV customers. This survey focus on viewing this smart
interactions from an algorithmic perspective. In particular, important
dominating factors for coordinated charging from three different perspectives
are studied, in terms of smart grid oriented, aggregator oriented and customer
oriented smart charging. Firstly, for smart grid oriented EV charging, we
summarize various formulations proposed for load flattening, frequency
regulation and voltage regulation, then explore the nature and substantial
similarity among them. Secondly, for aggregator oriented EV charging, we
categorize the algorithmic approaches proposed by research works sharing this
perspective as direct and indirect coordinated control, and investigate these
approaches in detail. Thirdly, for customer oriented EV charging, based on a
commonly shared objective of reducing charging cost, we generalize different
formulations proposed by studied research works. Moreover, various uncertainty
issues, e.g., EV fleet uncertainty, electricity price uncertainty, regulation
demand uncertainty, etc., have been discussed according to the three
perspectives classified. At last, we discuss challenging issues that are
commonly confronted during modeling the smart interactions, and outline some
future research topics in this exciting area.


title: BaTMAn: Bayesian Technique for Multi-image Analysis

abstract:
  This paper describes the Bayesian Technique for Multi-image Analysis
(BaTMAn), a novel image-segmentation technique based on Bayesian statistics
that characterizes any astronomical dataset containing spatial information and
performs a tessellation based on the measurements and errors provided as input.
The algorithm iteratively merges spatial elements as long as they are
statistically consistent with carrying the same information (i.e. identical
signal within the errors). We illustrate its operation and performance with a
set of test cases including both synthetic and real Integral-Field
Spectroscopic data. The output segmentations adapt to the underlying spatial
structure, regardless of its morphology and/or the statistical properties of
the noise. The quality of the recovered signal represents an improvement with
respect to the input, especially in regions with low signal-to-noise ratio.
However, the algorithm may be sensitive to small-scale random fluctuations, and
its performance in presence of spatial gradients is limited. Due to these
effects, errors may be underestimated by as much as a factor of two. Our
analysis reveals that the algorithm prioritizes conservation of all the
statistically-significant information over noise reduction, and that the
precise choice of the input data has a crucial impact on the results. Hence,
the philosophy of BaTMAn is not to be used as a `black box' to improve the
signal-to-noise ratio, but as a new approach to characterize spatially-resolved
data prior to its analysis. The source code is publicly available at
http://astro.ft.uam.es/SELGIFS/BaTMAn .


title:
Quantum Transport in Graphene in Presence of Strain-Induced
  Pseudo-Landau Levels

abstract:
  We report on mesoscopic transport fingerprints in disordered graphene caused
by strain-field induced pseudomagnetic Landau levels (pLLs). Efficient
numerical real space calculations of the Kubo formula are performed for an
ordered network of nanobubbles in graphene, creating pseudomagnetic fields up
to several hundreds of Tesla, values inaccessible by real magnetic fields.
Strain-induced pLLs yield enhanced scattering effects across the energy
spectrum resulting in lower mean free path and enhanced localization effects.
In the vicinity of the zeroth order pLL, we demonstrate an anomalous transport
regime, where the mean free paths increases with disorder. We attribute this
puzzling behavior to the low-energy sub-lattice polarization induced by the
zeroth order pLL, which is unique to pseudomagnetic fields preserving
time-reversal symmetry. These results, combined with the experimental
feasibility of reversible deformation fields, open the way to tailor a
metal-insulator transition driven by pseudomagnetic fields.


title: Softness, Polynomial Boundedness and Amplitudes' Positivity

abstract:
  In this note, we study the connections between infrared (IR) and ultraviolet
(UV) behaviors of scattering amplitudes of massless channels by exploiting
dispersion relations and positivity bounds. Given forward scattering
amplitudes, which scale as $\mathcal{A}(s)\sim s^M$ in the IR ($s\to0$) and
could be embedded into UV completions satisfying unitarity, analyticity,
crossing symmetry and polynomial boundedness $|\mathcal{A}(s)|< c\, |s|^N$
($|s|\to\infty$), with $M$ and $N$ integers, we show that the inequality
$2\ceil*{\frac{N}{2}}\ge M \ge \ceil*{\frac{N}{2}}$ must hold, where
$\ceil*{x}$ is the smallest integer greater than or equal to $x$. One immediate
consequence of the above inequality is the bound on the UV growth of scattering
amplitudes in terms of their IR behaviors. Our results could be useful in
studies of massless higher spin particles, as well as the program of UV
improvement and weakly-coupled UV completion.


title: Melnikov's method in String Theory

abstract:
  Melnikov's method is an analytical way to show the existence of classical
chaos generated by a Smale horseshoe. It is a powerful technique, though its
applicability is somewhat limited. In this paper, we present a solution of type
IIB supergravity to which Melnikov's method is applicable. This is a brane-wave
type deformation of the AdS$_5\times$S$^5$ background. By employing two
reduction ans\"atze, we study two types of coupled pendulum-oscillator systems.
Then the Melnikov function is computed for each of the systems by following the
standard way of Holmes and Marsden and the existence of chaos is shown
analytically.


title: Universality of Makespan in Flowshop Scheduling Problem

abstract:
  Makespan, which is defined as the time difference between the starting time
and the terminate time of a sequence of jobs or tasks, as the time to traverse
a belt conveyor system, is well known as one of the most important criteria in
scheduling problems. It is often used by manufacturing firms in practice in
order to improve the operational efficiency with respect to the order of job
processing to be performed. It is known that the performance of a machine
depends on the particular timing of the job processing even if the job
processing order is fixed. That is, the performance of a system with respect to
flowshop processing depends on the procedure of scheduling. In this present
work, we first discuss the relationship between makespan and several scheduling
procedures in detail by using a small example and provide an algorithm for
deriving the makespan. Using our proposed algorithm, several numerical
experiments are examined so as to reveal the relationship between the typical
behavior of makespan and the position of the fiducial machine, with respect to
several distinguished distributions of the processing time. We also discuss the
behavior of makespan by using the properties of the shape functions used in the
context of percolation theory. Our contributions are firstly giving a detail
discussion on the universality of makespan in flowshop problems and obtaining
several novel properties of makespan, as follows: (1) makespan possesses
universality in the sense of being little affected by a change in the
probability distribution of the processing time, (2) makespan can be decomposed
into the sum of two shape functions, and (3) makespan is less affected by the
dispatching rule than by the scheduling procedure.


title: Tracking with multi-level features

abstract:
  We present a novel formulation of the multiple object tracking problem which
integrates low and mid-level features. In particular, we formulate the tracking
problem as a quadratic program coupling detections and dense point
trajectories. Due to the computational complexity of the initial QP, we propose
an approximation by two auxiliary problems, a temporal and spatial association,
where the temporal subproblem can be efficiently solved by a linear program and
the spatial association by a clustering algorithm. The objective function of
the QP is used in order to find the optimal number of clusters, where each
cluster ideally represents one person. Evaluation is provided for multiple
scenarios, showing the superiority of our method with respect to classic
tracking-by-detection methods and also other methods that greedily integrate
low-level features.


title: Szego\H o-Widom asymptotics of Chebyshev Polynomials on Circular Arcs

abstract:
  Thiran and Detaille give an explicit formula for the asymptotics of the
sup-norm of the Chebyshev polynomials on a circular arc. We give the so-called
$\textrm{Szeg\H o}$-Widom asymptotics for this domain, i.e., explicit
expressions for the asymptotics of the corresponding extremal polynomials.
Moreover, we solve a similar problem with respect to the upper envelope of a
family of polynomials uniformly bounded on this arc. That is, we give explicit
formulas for the asymptotics of the error of approximation as well as of the
extremal functions. Our computations show that in the proper normalization the
limit of the upper envelope represents the diagonal of a reproducing kernel of
a certain Hilbert space of analytic functions. Due to Garabedian the analytic
capacity in an arbitrary domain is the diagonal of the corresponding
$\textrm{Szeg\H o}$ kernel. We don't know any result of this kind with respect
to upper envelopes of polynomials. If this is a general fact or a specific
property of the given domain, we rise as an open question.


title:
The Costs and Benefits of Sharing: Sequential Individual Rationality and
  Sequential Fairness

abstract:
  In designing dynamic shared service systems that incentivize customers to opt
for shared rather than exclusive service, the traditional notion of individual
rationality may be insufficient, as a customer's estimated utility could
fluctuate arbitrarily during their time in the shared system, as long as their
realized utility at service completion is not worse than that for exclusive
service. In this work, within a model that explicitly considers the
"inconvenience costs" incurred by customers due to sharing, we introduce the
notion of sequential individual rationality (SIR) that requires that the
disutility of existing customers is nonincreasing as the system state changes
due to new customer arrivals. Next, under SIR, we observe that cost sharing can
also be viewed as benefit sharing, which inspires a natural definition of
sequential fairness (SF) - the total incremental benefit due to a new customer
is shared among existing customers in proportion to the incremental
inconvenience suffered.
  We demonstrate the effectiveness of these notions by applying them to a
ridesharing system, where unexpected detours to pick up subsequent passengers
inconvenience the existing passengers. Imposing SIR and SF reveals interesting
and surprising results, including: (a) natural limits on the incremental
detours permissible, (b) exact characterization of "SIR-feasible" routes, which
boast sublinear upper and lower bounds on the fractional detours, (c) exact
characterization of sequentially fair cost sharing schemes, which includes a
strong requirement that passengers must compensate each other for the detour
inconveniences that they cause, and (d) new algorithmic problems related to and
motivated by SIR.


title:
Pair approximation for the q-voter model with independence on complex
  networks

abstract:
  We investigate the q-voter model with stochastic noise arising from
independence on complex networks. Using the pair approximation, we provide a
comprehensive, mathematical description of its behavior and derive a formula
for the critical point. The analytical results are validated by carrying out
Monte Carlo experiments. The pair approximation prediction exhibits substantial
agreement with simulations, especially for networks with weak clustering and
large average degree. Nonetheless, for the average degree close to q, some
discrepancies originate. It is the first time we are aware of that the
presented approach has been applied to the nonlinear voter dynamics with noise.
Up till now, the analytical results have been obtained only for a complete
graph. We show that in the limiting case the prediction of pair approximation
coincides with the known solution on a fully connected network.


title:
Constraints on the Broad Line Region Properties and Extinction in Local
  Seyferts

abstract:
  We use high spectral resolution (R > 8000) data covering 3800-13000\r{A} to
study the physical conditions of the broad line region (BLR) of nine nearby
Seyfert 1 galaxies. Up to six broad HI lines are present in each spectrum. A
comparison - for the first time using simultaneous optical to near-infrared
observations - to photoionisation calculations with our devised simple scheme
yields the extinction to the BLR at the same time as determining the density
and photon flux, and hence distance from the nucleus, of the emitting gas. This
points to a typical density for the HI emitting gas of 10$^{11}$cm$^{-3}$ and
shows that a significant amount of this gas lies at regions near the dust
sublimation radius, consistent with theoretical predictions. We also confirm
that in many objects the line ratios are far from case B, the best-fit
intrinsic broad-line H$\alpha$/H$\beta$ ratios being in the range 2.5-6.6 as
derived with our photoionization modeling scheme. The extinction to the BLR,
based on independent estimates from HI and HeII lines, is A$_V$ $\le$ 3 for
Seyfert 1-1.5s, while Seyfert 1.8-1.9s have A$_V$ in the range 4-8. A
comparison of the extinction towards the BLR and narrow line region (NLR)
indicates that the structure obscuring the BLR exists on scales smaller than
the NLR. This could be the dusty torus, but dusty nuclear spirals or filaments
could also be responsible. The ratios between the X-ray absorbing column N$_H$
and the extinction to the BLR are consistent with the Galactic gas-to-dust
ratio if N$_H$ variations are considered.


title:
Renormalization Group Evolution of Dimension-seven Baryon- and
  Lepton-number-violating Operators

abstract:
  We study dimension-seven operators in standard model effective field theory.
These operators are classified into two sets, one violating lepton number but
preserving baryon number ($\Delta L=\pm 2$, $\Delta B=0$) and the other
violating both but preserving their sum ($-\Delta L=\Delta B=\pm 1$). It has
been found in the previous literature that there are respectively 13 and 7 such
independent operators. We show that one operator is redundant in each set so
that the complete list contains only 12 and 6 operators respectively. We
accomplish this by using standard model equations of motion and various Fierz
identities. We calculate the one-loop anomalous dimension matrix for the 6
operators in the second set, and illustrate its possible phenomenological
implications by working out renormalization group running of the Wilson
coefficients that could contribute to the type of proton decays with $-\Delta
L=\Delta B=\pm 1$, such as $p\to\nu\pi^+$.


title: Optically enhanced production of metastable xenon

abstract:
  Metastable states of noble gas atoms are typically produced by electrical
discharge techniques or "all-optical" excitation methods. Here we combine
electrical discharges with optical pumping to demonstrate "optically enhanced"
production of metastable xenon (Xe*). We experimentally measure large increases
in Xe* density with relatively small optical control field powers. This
technique may have applications in systems where large metastable state
densities are desirable.


title: Estimating Activity at Multiple Scales using Spatial Abstractions

abstract:
  Autonomous robots operating in dynamic environments must maintain beliefs
over a hypothesis space that is rich enough to represent the activities of
interest at different scales. This is important both in order to accommodate
the availability of evidence at varying degrees of coarseness, such as when
interpreting and assimilating natural instructions, but also in order to make
subsequent reactive planning more efficient. We present an algorithm that
combines a topology-based trajectory clustering procedure that generates
hierarchically-structured spatial abstractions with a bank of particle filters
at each of these abstraction levels so as to produce probability estimates over
an agent's navigation activity that is kept consistent across the hierarchy. We
study the performance of the proposed method using a synthetic trajectory
dataset in 2D, as well as a dataset taken from AIS-based tracking of ships in
an extended harbour area. We show that, in comparison to a baseline which is a
particle filter that estimates activity without exploiting such structure, our
method achieves a better normalised error in predicting the trajectory as well
as better time to convergence to a true class when compared against ground
truth.


title: Conformal Anomalies and Gravitational Waves

abstract:
  We argue that the presence of conformal anomalies in gravitational theories
can lead to observable modifications to Einstein's equations via the induced
anomalous effective actions, whose non-localities can overwhelm the smallness
of the Planck scale. The fact that no such effects have been seen in recent
cosmological or gravitational wave observations therefore imposes strong
restrictions on the field content of possible extensions of Einstein's theory:
all viable theories should have vanishing conformal anomalies. We then show
that a complete cancellation of conformal anomalies in D=4 for both the $C^2$
invariant and the Euler (Gauss-Bonnet) invariant can only be achieved for
N-extended supergravities with $N \geq 5$, as well as for M theory compactified
to four dimensions.


title: A new labeling construction from the $\otimes_h$-product

abstract:
  The $\otimes_h$-product that refers the title was introduced in 2008 as a
generalization of the Kronecker product of digraphs. Many relations among
labelings have been obtained since then, always using as a second factor a
family of super edge-magic graphs with equal order and size. In this paper, we
introduce a new labeling construction by changing the role of the factors.
Using this new construction the range of applications grows up considerably. In
particular, we can increase the information about magic sums of cycles and
crowns.


title:
Experimental demonstration of robust entanglement distribution over
  reciprocal noisy channels assisted by a counter-propagating classical
  reference light

abstract:
  We experimentally demonstrate a proposal [Phys. Rev. A 87, 052325 (2013)] of
a scheme for robust distribution of polarization entangled photon pairs over
collective noisy channels having the reciprocity. Although the scheme employs
the robustness of two qubit decoherence-free subspace, by utilizing the forward
propagation of one half of the entangled photons and the backward propagation
of a classical reference light, it achieves an entanglement-sharing rate
proportional to the transmittance of the quantum channel for the signal photon.
We experimentally observed the efficient sharing rate while keeping a highly
entangled state after the transmission. We also show that the protection method
is applicable to transmission of arbitrary polarization state of a single
photon.


title: The chaotic dynamics of large-scale structures in a turbulent wake

abstract:
  The dynamics of a 3D bimodal turbulent wake downstream a square-back Ahmed
body are experimentally studied in a wind-tunnel through high-frequency wall
pressure probes mapping the rear of the model and a horizontal 2D velocity
field. The barycenters of the pressure distribution over the rear part of the
model and the intensity recirculation are found highly correlated. Both
described the most energetic large-scale structures dynamics, confirming the
relation between the large-scale recirculation bubble and its wall pressure
foot-print. Focusing on the pressure, its barycenter trajectory has a
stochastic behavior but its low frequencies dynamics exhibit the same
characteristics as a weak strange chaotic attractor system, with two well
defined attractors. The low frequencies dynamics associated to the large-scale
structures are then analyzed. The largest Lyapunov exponent is first estimated,
leading to a low positive value characteristic of strange attractors and weak
chaotic systems. Afterwards, analyzing the autocorrelation function of the
time-series, we compute the correlation dimension, larger than two. The signal
is finally transformed and analyzed as a telegraph signal showing that its
dynamics correspond to a quasi-random telegraph signal. This is the first
demonstration that the low frequencies dynamics of a turbulent 3D wake are not
a purely stochastic process but rather a weak chaotic process exhibiting
strange attractors. From the flow-control point of view, it also opens the path
to more simple closed-loop flow control strategies aiming at the stabilization
of the wake and the control of the dynamics of the wake barycenter.


title: Electroweak Baryogenesis with Lepton Flavor Violation

abstract:
  We investigate the feasibility of electroweak baryogenesis in a two-Higgs
doublet model with lepton flavor violation. By scrutinizing the heavy Higgs
boson mass spectrum, regions satisfying both strong first-order electroweak
phase transition and the muon $g-2$ anomaly are identified. We also estimate
the baryon number density by exploiting extra Yukawa couplings in the
$\mu$-$\tau$ sector. It is found that a CP-violating source term can be
enhanced by the $\mu$-$\tau$ flavor-violating coupling together with the extra
$\tau$ coupling. With $\mathcal{O}(1)$ Yukawa couplings and CP-violating
phases, the observed baryon number density is marginally produced under a
generous assumption for the bubble wall profile.


title:
Stellar mass distribution of S$^4$G disk galaxies and signatures of
  bar-induced secular evolution

abstract:
  We use 3.6 $\mu$m photometry from the Spitzer Survey of Stellar Structure in
Galaxies (S$^{4}$G) to trace the stellar distribution in nearby disk galaxies
($z\approx0$) with total stellar masses $10^{8.5}\lesssim
M_{\ast}/M_{\odot}\lesssim10^{11}$ and mid-IR Hubble types $-3 \le T \le 10$,
and to provide observational constraints for galaxy formation models to be
checked against. For 1154 galaxies with disk inclinations lower than
$65^{\circ}$, we Fourier decompose and rescale their images to a common frame
determined (i) by the size in physical units, (ii) by their disk scalelength,
and for 748 barred galaxies (iii) by both the length and orientation of their
bars. We stack the resized density profiles and images to obtain statistically
representative average stellar disks and bars in bins of $M_{\ast}$ and $T$. We
also calculate the mean stellar contribution to the circular velocity. We infer
the gravitational potentials from the synthetic bars to obtain the
tangential-to-radial force ratio ($Q_{\rm T}$) and $A_2$ profiles in the
different bins. We provide observational evidence for bar-induced secular
evolution of disk galaxies. For $M_{\ast} \ge 10^{9}M_{\odot}$, we find a
significant difference in the stellar density profiles of barred and non-barred
systems: (i) disks in barred galaxies show larger scalelengths ($h_{\rm R}$)
and fainter extrapolated central surface brightnesses ($\Sigma_{0}$), (ii) the
mean surface brightness profiles ($\Sigma_{\ast}$) of barred and non-barred
galaxies intersect each other slightly beyond the mean bar length, most likely
at the bar corotation, and (iii) the central mass concentration of barred
galaxies is larger (by almost a factor 2 when $T\le5$) than in their non-barred
counterparts. We also show that bars hosted by early-type galaxies are more
centrally concentrated and have larger density amplitudes than their late-type
counterparts (Abridged).


title: Forcer: a FORM program for 4-loop massless propagators

abstract:
  We present a new FORM program for analytically evaluating four-loop massless
propagator-type Feynman integrals in an efficient way. Our program Forcer
implements parametric reductions of the aforementioned class of Feynman
integrals into a set of master integrals and can be considered as a four-loop
extension of the three-loop Mincer program. Since the program structure at the
four-loop level is highly complicated and the equations easily become lengthy,
most of the code was generated in an automatic way or with computer-assisted
derivations. We have checked correctness of the program by recomputing
already-known quantities in the literature.


title: CWENO: uniformly accurate reconstructions for balance laws

abstract:
  In this paper we introduce a general framework for defining and studying
essentially non-oscillatory reconstruction procedures of arbitrarily high order
accuracy, interpolating data in a central stencil around a given computational
cell ($\CWENO$). This technique relies on the same selection mechanism of
smooth stencils adopted in $\WENO$, but here the pool of candidates for the
selection includes polynomials of different degrees. This seemingly minor
difference allows to compute an analytic expression of a polynomial
interpolant, approximating the unknown function uniformly within a cell,
instead of only at one point at a time. For this reason this technique is
particularly suited for balance laws for finite volume schemes, when averages
of source terms require high order quadrature rules based on several points; in
the computation of local averages, during refinement in h-adaptive schemes; or
in the transfer of the solution between grids in moving mesh techniques, and in
general when a globally defined reconstruction is needed. Previously, these
needs have been satisfied mostly by ENO reconstruction techniques, which,
however, require a much wider stencil then the $\CWENO$ reconstruction studied
here, for the same accuracy.


title:
Modeling the Excitation of Graphene Plasmons in Periodic Grids of
  Graphene Ribbons: An Analytical Approach

abstract:
  We study electromagnetic scattering and subsequent plasmonic excitations in
periodic grids of graphene ribbons. To address this problem, we develop an
analytical method to describe the plasmon-assisted absorption of
electromagnetic radiation by a periodic structure of graphene ribbons forming a
diffraction grating for THz and mid-IR light. The major advantage of this
method lies in its ability to accurately describe the excitation of graphene
surface plasmons (GSPs) in one-dimensional (1D) graphene gratings without the
use of both time-consuming, and computationally-demanding full-wave numerical
simulations. We thus provide analytical expressions for the reflectance,
transmittance and plasmon-enhanced absorbance spectra, which can be readily
evaluated in any personal laptop with little-to-none programming. We also
introduce a semi-analytical method to benchmark our previous results and
further compare the theoretical data with spectra taken from experiments, to
which we observe a very good agreement. These theoretical tools may therefore
be applied to design new experiments and cutting-edge nanophotonic devices
based on graphene plasmonics.


title:
Non-bolometric bottleneck in electron-phonon relaxation in ultra-thin
  WSi film

abstract:
  We developed the model of the internal phonon bottleneck to describe the
energy exchange between the acoustically soft ultrathin metal film and
acoustically rigid substrate. Discriminating phonons in the film into two
groups, escaping and nonescaping, we show that electrons and nonescaping
phonons may form a unified subsystem, which is cooled down only due to
interactions with escaping phonons, either due to direct phonon conversion or
indirect sequential interaction with an electronic system. Using an
amplitude-modulated absorption of the sub-THz radiation technique, we studied
electron-phonon relaxation in ultrathin disordered films of tungsten silicide.
We found an experimental proof of the internal phonon bottleneck. The
experiment and simulation based on the proposed model agree well, resulting in
tau_{e-ph} = 140-190 ps at T_C = 3.4 K, supporting the results of earlier
measurements by independent techniques.


title:
Generalized Schr\"odinger-Newton system in dimension $N\ge 3$: critical
  case

abstract:
  In this paper we study a system which is equivalent to a nonlocal version of
the well known Brezis Nirenberg problem. The difficulties related with the lack
of compactness are here emphasized by the nonlocal nature of the critical
nonlinear term. We prove existence and nonexistence results of positive
solutions when $N=3$ and existence of solutions in both the resonance and the
nonresonance case for higher dimensions.


title:
MHD simulations of three-dimensional Resistive Reconnection in a
  cylindrical plasma column

abstract:
  Magnetic reconnection is a plasma phenomenon where a topological
rearrangement of magnetic field lines with opposite polarity results in
dissipation of magnetic energy into heat, kinetic energy and particle
acceleration. Such a phenomenon is considered as an efficient mechanism for
energy release in laboratory and astrophysical plasmas. An important question
is how to make the process fast enough to account for observed explosive energy
releases. The classical model for steady state magnetic reconnection predicts
reconnection times scaling as $S^{1/2}$ (where $S$ is the Lundquist number) and
yields times scales several order of magnitude larger than the observed ones.
Earlier two-dimensional MHD simulations showed that for large Lundquist number
the reconnection time becomes independent of $S$ ("fast reconnection" regime)
due to the presence of the secondary tearing instability that takes place for
$S \gtrsim 1 \times 10^4$. We report on our 3D MHD simulations of magnetic
reconnection in a magnetically confined cylindrical plasma column under either
a pressure balanced or a force-free equilibrium and compare the results with 2D
simulations of a circular current sheet. We find that the 3D instabilities
acting on these configurations result in a fragmentation of the initial current
sheet in small filaments, leading to enhanced dissipation rate that becomes
independent of the Lundquist number already at $S \simeq 1\times 10^3$.


title: Results and Prospects from the Daya Bay Reactor Neutrino Experiment

abstract:
  The Daya Bay reactor experiment has reported the most precise measurement of
sin$^{2}2\theta_{13}$ and $\Delta m^{2}_{ee}$ by using a data set with the
fully constructed design of 8 antineutrino detectors (ADs). We also report on a
new independent measurement of sin$^{2}2\theta_{13}$ from neutron capture on
hydrogen, which confirms the results using gadolinium caputres. Several other
analyses are also performed, including a measurements on the absolute reactor
antineutrino flux and a search for light sterile neutrinos. Prospects for new
analyses such as searching for CPT/LI violation at Daya Bay are ongoing.


title:
The local black hole mass function derived from the M_{BH}-P and the
  M_{BH}-n relations

abstract:
  We present a determination of the supermassive black hole (SMBH) mass
function for early- and late-type galaxies in the nearby universe (z<0.0057),
established from a volume-limited sample consisting of a statistically complete
collection of the brightest spiral galaxies in the southern hemisphere. The
sample is defined by limiting luminosity (redshift-independent) distance,
D_L=25.4 Mpc, and a limiting absolute B-band magnitude, M_B=-19.12. These
limits define a sample of 140 spiral, 30 elliptical (E), and 38 lenticular (S0)
galaxies. We established the Sersic index distribution for early-type (E/S0)
galaxies in our sample. Davis et al. (2014) established the pitch angle
distribution for their sample, which is identical to our late-type (spiral)
galaxy sample. We then used the pitch angle and the Sersic index distributions
in order to estimate the SMBH mass function for our volume-limited sample. The
observational simplicity of our approach relies on the empirical relation
between the mass of the central (SMBH) and the Sersic index (Graham et al.
2007) for an early-type galaxy or the logarithmic spiral arm pitch angle
(Berrier et al. 2013) for a spiral galaxy. Our SMBH mass function agrees well
at the high-mass end with previous values in the literature. At the low-mass
end, while inconsistencies exist in previous works that still need to be
resolved, our work is more in line with expectations based on modeling of black
hole evolution.


title:
Meta-Prod2Vec - Product Embeddings Using Side-Information for
  Recommendation

abstract:
  We propose Meta-Prod2vec, a novel method to compute item similarities for
recommendation that leverages existing item metadata. Such scenarios are
frequently encountered in applications such as content recommendation, ad
targeting and web search. Our method leverages past user interactions with
items and their attributes to compute low-dimensional embeddings of items.
Specifically, the item metadata is in- jected into the model as side
information to regularize the item embeddings. We show that the new item
representa- tions lead to better performance on recommendation tasks on an open
music dataset.


title: Search for light scalar Dark Matter candidate with AURIGA detector

abstract:
  A search for a new scalar field, called moduli, has been performed using the
cryogenic resonant-mass AURIGA detector. Predicted by string theory, moduli may
provide a significant contribution to the dark matter (DM) component of our
universe. If this is the case, the interaction of ordinary matter with the
local DM moduli, forming the Galaxy halo, will cause an oscillation of solid
bodies with a frequency corresponding to the mass of moduli. In the sensitive
band of AURIGA, some $100\,\mathrm{Hz}$ at around $1\,\mathrm{kHz}$, the
expected signal, with a $Q=\tfrac{\triangle f}{f}\sim10^{6}$, is a narrow peak,
$\triangle f\sim1\,\mathrm{mHz}$. Here the detector strain sensitivity is
$h_{s}\sim2\times10^{-21}\,\mathrm{Hz^{-1/2}}$, within a factor of $2$. These
numbers translate to upper limits at $95\%\,C.L.$ on the moduli coupling to
ordinary matter $d_{e}\lesssim10^{-5}$ around masses
$m_{\phi}=3.6\cdot10^{-12}\,\mathrm{eV}$, for the standard DM halo model with
$\rho_{DM}=0.3\,\mathrm{GeV/cm^{3}}$.


title: Decaying dark matter search with NuSTAR deep sky observations

abstract:
  We present the results of the search for decaying dark matter with particle
mass in the 6-40 keV range with NuSTAR deep observations of COSMOS and ECDFS
empty sky fields. We show that main contribution to the decaying dark matter
signal from the Milky Way galaxy comes through the aperture of the NuSTAR
detector, rather than through the focusing optics. High sensitivity of the
NuSTAR detector, combined with the large aperture and large exposure times of
the two observation fields allow us to improve previously existing constraints
on the dark matter decay time by up to an order of magnitude in the mass range
10-30 keV. In the particular case of the nuMSM sterile neutrino dark matter,
our constraints impose an upper bound m<20 keV on the dark matter particle
mass. We report detection of four unidentified spectral lines in our data set.
These line detections are either due to the systematic effects (uncertainties
of calibrations of the NuSTAR detectors) or have an astrophysical origin. We
discuss different possibilities for testing the nature of the detected lines.


title: Accelerating Stochastic Composition Optimization

abstract:
  Consider the stochastic composition optimization problem where the objective
is a composition of two expected-value functions. We propose a new stochastic
first-order method, namely the accelerated stochastic compositional proximal
gradient (ASC-PG) method, which updates based on queries to the sampling oracle
using two different timescales. The ASC-PG is the first proximal gradient
method for the stochastic composition problem that can deal with nonsmooth
regularization penalty. We show that the ASC-PG exhibits faster convergence
than the best known algorithms, and that it achieves the optimal sample-error
complexity in several important special cases. We further demonstrate the
application of ASC-PG to reinforcement learning and conduct numerical
experiments.


title:
Evaluating Link Prediction Accuracy on Dynamic Networks with Added and
  Removed Edges

abstract:
  The task of predicting future relationships in a social network, known as
link prediction, has been studied extensively in the literature. Many link
prediction methods have been proposed, ranging from common neighbors to
probabilistic models. Recent work by Yang et al. has highlighted several
challenges in evaluating link prediction accuracy. In dynamic networks where
edges are both added and removed over time, the link prediction problem is more
complex and involves predicting both newly added and newly removed edges. This
results in new challenges in the evaluation of dynamic link prediction methods,
and the recommendations provided by Yang et al. are no longer applicable,
because they do not address edge removal. In this paper, we investigate several
metrics currently used for evaluating accuracies of dynamic link prediction
methods and demonstrate why they can be misleading in many cases. We provide
several recommendations on evaluating dynamic link prediction accuracy,
including separation into two categories of evaluation. Finally we propose a
unified metric to characterize link prediction accuracy effectively using a
single number.


title:
Uncertainty relations for incompatible observables: Newer results versus
  modified strategies

abstract:
  Two special situations where the standard uncertainty product inequality
appears to be useless are modified. One such case is noted to also trivialize
the recently-introduced alternatives [Phys. Rev. Lett. 113, 260401 (2014); Sci.
Rep. 6, 23201 (2016)] involving sums of variances. A careful discussion is
presented on the experimental justifications of some of the relations [Phys.
Rev. A 93, 052108 (2016)] using qutrit and qubit states. Alternative bypass
routes are put forward to tackle this situation, with and without involving any
auxiliary state. This latter strategy is noted to be vital in an entirely
different context concerned with the quality of approximate stationary states.
The other case is more frustrating, but an effective method is advanced. En
route, the recent alternatives are also simplified to easily accommodate even
the cases of more than two observables. In favorable circumstances, an easy
option in function space is obtained by virtue of symmetry that does not
involve any auxiliary state. Pilot calculations reveal the advantages of our
endeavor.


title:
Improving the phase super-sensitivity of squeezing-assisted
  interferometers by squeeze factor unbalancing

abstract:
  The sensitivity properties of an SU(1,1) interferometer made of two cascaded
parametric amplifiers, as well as of an ordinary SU(2) interferometer preceded
by a squeezer and followed by an anti-squeezer, are theoretically investigated.
Several possible experimental configurations are considered, such as the
absence or presence of a seed beam, direct or homodyne detection scheme. In all
cases we formulate the optimal conditions to achieve phase super-sensitivity,
meaning a sensitivity overcoming the shot-noise limit. We show that for a given
gain of the first parametric amplifier, unbalancing the interferometer by
increasing the gain of the second amplifier improves the interferometer
properties. In particular, a broader super-sensitivity phase range and a better
overall sensitivity can be achieved by gain unbalancing.


title:
Influence of a second satellite on the rotational dynamics of an oblate
  moon

abstract:
  The gravitational influence of a second satellite on the rotation of an
oblate moon is numerically examined. A simplified model, assuming the axis of
rotation perpendicular to the (Keplerian) orbit plane, is derived. The
differences between the two models, i.e. in the absence and presence of the
second satellite, are investigated via bifurcation diagrams and by evolving
compact sets of initial conditions in the phase space. It turns out that the
presence of another satellite causes some trajectories, that were regular in
its absence, to become chaotic. Moreover, the highly structured picture
revealed by the bifurcation diagrams in dependence on the eccentricity of the
oblate body's orbit is destroyed when the gravitational influence is included,
and the periodicities and critical curves are destroyed as well. For
demonstrative purposes, focus is laid on parameters of the
Saturn-Titan-Hyperion system, and on oblate satellites on low-eccentric orbits,
i.e. $e\approx 0.005$.


title: Exploring Perturbative Conformal Field Theory in Mellin space

abstract:
  We explore the Mellin representation of correlation functions in conformal
field theories in the weak coupling regime. We provide a complete proof for a
set of Feynman rules to write the Mellin amplitude for a general tree level
Feynman diagram involving only scalar operators. We find a factorised form
involving beta functions associated to the propagators, similar to tree level
Feynman rules in momentum space for ordinary QFTs. We also briefly consider the
case where a generic scalar perturbation of the free CFT breaks conformal
invariance. Mellin space still has some utility and one can consider
non-conformal Mellin representations. In this context, we find that the beta
function corresponding to conformal propagator uplifts to a hypergeometric
function.


title:
An Explicit, Coupled-Layer Construction of a High-Rate MSR Code with Low
  Sub-Packetization Level, Small Field Size and All-Node Repair

abstract:
  This paper presents an explicit construction for an $((n,k,d=n-1),
(\alpha,\beta))$ regenerating code over a field $\mathbb{F}_Q$ operating at the
Minimum Storage Regeneration (MSR) point. The MSR code can be constructed to
have rate $k/n$ as close to $1$ as desired, sub-packetization given by
$r^{\frac{n}{r}}$, for $r=(n-k)$, field size no larger than $n$ and where all
code symbols can be repaired with the same minimum data download. The
construction modifies a prior construction by Sasidharan et. al. which required
far larger field-size. A building block appearing in the construction is a
scalar MDS code of block length $n$. The code has a simple layered structure
with coupling across layers, that allows both node repair and data recovery to
be carried out by making multiple calls to a decoder for the scalar MDS code.
While this work was carried out independently, there is considerable overlap
with a prior construction by Ye and Barg.
  It is shown here that essentially the same architecture can be employed to
construct MSR codes using vector binary MDS codes as building blocks in place
of scalar MDS codes. The advantage here is that computations can now be carried
out over a field of smaller size potentially even over the binary field as we
demonstrate in an example. Further, we show how the construction can be
extended to handle the case of $d<(n-1)$ under a mild restriction on the choice
of helper nodes.


title:
Spin-orbit-coupling-induced magnetic heterostructure in the bilayer
  Bose-Hubbard system

abstract:
  We investigate magnetic phase in the bilayer system of ultra-cold bosons in
an optical lattice, which is involved with Raman-induced spin-orbit (SO)
coupling and laser-assisted interlayer tunneling. It is shown that there exit a
rich of spin textures such as hetero ferromagnet, heterochiral magnet, chiral
magnet with interlayer antiferromagnet. In particular, heterochiral magnet
induced by SO coupling occurs extremely rarely in real solid-state materials.
We present detailed experimental setup of realizing such a model in cold atom
system.


title:
Autonomous absolute calibration of an ICCD camera in single-photon
  detection regime

abstract:
  Intensified charge coupled device (ICCD) cameras are widely used in various
applications such as microscopy, astronomy, spectroscopy. Often they are used
as single-photon detectors, with thresholding being an essential part of the
readout. In this paper, we measure the quantum efficiency of an ICCD camera in
the single-photon detection mode using the Klyshko absolute calibration
technique. The quantum efficiency is obtained as a function of the threshold
value and of the wavelength of the detected light. In addition, we study the
homogeneity of the photon sensitivity over the camera chip area. The experiment
is performed in the autonomous regime, without using any additional detectors.
We therefore demonstrate the self-calibration of an ICCD camera.


title: Nano-Scale `Dark State' Optical Potentials for Cold Atoms

abstract:
  We discuss generation of subwavelength optical barriers on the scale of tens
of nanometers, as conservative optical potentials for cold atoms. These arise
from non-adiabatic corrections to Born-Oppenheimer potentials from dressed
`dark states' in atomic $\Lambda$-configurations. We illustrate the concepts
with a double layer potential for atoms obtained from inserting an optical
subwavelength barrier into a well generated by an off-resonant optical lattice,
and discuss bound states of pairs of atoms interacting via magnetic dipolar
interactions. The subwavelength optical barriers represent an optical
`Kronig-Penney' potential. We present a detailed study of the bandstructure in
optical `Kronig-Penney' potentials, including decoherence from spontaneous
emission and atom loss to open `bright' channels.


title: Chaotic and Topological Properties of Continued Fractions

abstract:
  We prove that there exists a scrambled set for the Gauss map with full
Hausdorff dimension. Meanwhile, we also investigate the topological properties
of the sets of points with dense or non-dense orbits.


title:
Developing and testing the density of states FFA method in the SU(3)
  spin model

abstract:
  The Density of States Functional Fit Approach (DoS FFA) is a recently
proposed modern density of states technique suitable for calculations in
lattice field theories with a complex action problem. In this article we
present an exploratory implementation of DoS FFA for the SU(3) spin system at
finite chemical potential $\mu$ - an effective theory for the Polyakov loop.
This model has a complex action problem similar to the one of QCD but also
allows for a dual simulation in terms of worldlines where the complex action
problem is solved. Thus we can compare the DoS FFA results to the reference
data from the dual simulation and assess the performance of the new approach.
We find that the method reproduces the observables from the dual simulation for
a large range of $\mu$ values, including also phase transitions, illustrating
that DoS FFA is an interesting approach for exploring phase diagrams of lattice
field theories with a complex action problem.


title:
On the Explanation of the Paramagnetic Meissner Effect in
  Superconductor/Ferromagnet Heterostructures

abstract:
  An increase of the magnetic moment in superconductor/ferromagnet (S/F)
bilayers V(40nm)/F [F$=$Fe(1,3nm), Co(3nm), Ni(3nm)] was observed using SQUID
magnetometry upon cooling below the superconducting transition temperature Tc
in magnetic fields of 10 Oe to 50 Oe applied parallel to the sample surface. A
similar increase, often called the paramagnetic Meissner effect (PME), was
observed before in various superconductors and superconductor/ferromagnet
systems. To explain the PME effect in the presented S/F bilayers a model based
on a row of vortices located at the S/F interface is proposed. According to the
model the magnetic moment induced below Tc consists of the paramagnetic
contribution of the vortex cores and the diamagnetic contribution of the
vortex-free region of the S layer. Since the thickness of the S layer is found
to be 3-4 times less than the magnetic field penetration depth, this latter
diamagnetic contribution is negligible. The model correctly accounts for the
sign, the approximate magnitude and the field dependence of the paramagnetic
and the Meissner contributions of the induced magnetic moment upon passing the
superconducting transition of a ferromagnet/superconductor bilayer.


title: Packing trees of unbounded degrees in random graphs

abstract:
  In this paper, we address the problem of packing large trees in $G_{n,p}$. In
particular, we prove the following result. Suppose that $T_1, \dotsc, T_N$ are
$n$-vertex trees, each of which has maximum degree at most $(np)^{1/6} / (\log
n)^6$. Then with high probability, one can find edge-disjoint copies of all the
$T_i$ in the random graph $G_{n,p}$, provided that $p \geq (\log n)^{36}/n$ and
$N \le (1-\varepsilon)np/2$ for a positive constant $\varepsilon$. Moreover, if
each $T_i$ has at most $(1-\alpha)n$ vertices, for some positive $\alpha$, then
the same result holds under the much weaker assumptions that $p \geq (\log
n)^2/(cn)$ and $\Delta(T_i) \leq c np / \log n$ for some~$c$ that depends only
on $\alpha$ and $\varepsilon$. Our assumptions on maximum degrees of the trees
are significantly weaker than those in all previously known approximate packing
results.


title: Gaussian processes and Bayesian moment estimation

abstract:
  Given a set of moment restrictions (MRs) that overidentify a parameter
$\theta$, we investigate a semiparametric Bayesian approach for inference on
$\theta$ that does not restrict the data distribution $F$ apart from the MRs.
As main contribution, we construct a degenerate Gaussian process prior that,
conditionally on $\theta$, restricts the $F$ generated by this prior to satisfy
the MRs with probability one. Our prior works even in the more involved case
where the number of MRs is larger than the dimension of $\theta$. We
demonstrate that the corresponding posterior for $\theta$ is computationally
convenient. Moreover, we show that there exists a link between our procedure,
the Generalized Empirical Likelihood with quadratic criterion and the limited
information likelihood-based procedures. We provide a frequentist validation of
our procedure by showing consistency and asymptotic normality of the posterior
distribution of $\theta$. The finite sample properties of our method are
illustrated through Monte Carlo experiments and we provide an application to
demand estimation in the airline market.


title: Newton and Bouligand derivatives of the scalar play and stop operator

abstract:
  We prove that the play and the stop operator possess Newton and Bouligand
derivatives, and exhibit formulas for those derivatives. The remainder estimate
is given in a strenghtened form, and a corresponding chain rule is developed.
The construction of the Newton derivative ensures that the mappings involved
are measurable.


title: Theory of disguised-groups

abstract:
  In this paper we define a new algebraic object: the disguised-groups. We show
the main properties of the disguised-groups and, as a consequence, we will see
that disguised-groups coincide with regular semigroups. We prove many of the
results of the theory of groups adapted to this case and some unknown results
in the theory of groups and regular semigroups.


title:
Using invariant manifolds to construct symbolic dynamics for
  three-dimensional volume-preserving maps

abstract:
  Topological techniques are powerful tools for characterizing the complexity
of many dynamical systems, including the commonly studied area-preserving maps
of the plane. However, the extension of many topological techniques to higher
dimensions is filled with roadblocks preventing their application. This article
shows how to extend the homotopic lobe dynamics (HLD) technique, previously
developed for 2D maps, to volume-preserving maps of a three-dimensional phase
space. Such maps are physically relevant to particle transport by
incompressible fluid flows or by magnetic field lines. Specifically, this
manuscript shows how to utilize two-dimensional stable and unstable invariant
manifolds, intersecting in a heteroclinic tangle, to construct a symbolic
representation of the topological dynamics of the map. This symbolic
representation can be used to classify system trajectories and to compute
topological entropy. We illustrate the salient ideas through a series of
examples with increasing complexity. These examples highlight new features of
the HLD technique in 3D. Ultimately, in the final example, our technique
detects a difference between the 2D stretching rate of surfaces and the 1D
stretching rate of curves, illustrating the truly 3D nature of our approach.


title:
Cosmological dynamics of spatially flat Einstein-Gauss-Bonnet models in
  various dimensions: Low-dimensional $\Lambda$-term case

abstract:
  In this paper we perform a systematic study of spatially flat
[(3+D)+1]-dimensional Einstein-Gauss-Bonnet cosmological models with
$\Lambda$-term. We consider models that topologically are the product of two
flat isotropic subspaces with different scale factors. One of these subspaces
is three-dimensional and represents our space and the other is D-dimensional
and represents extra dimensions. We consider no {\it Ansatz} on the scale
factors, which makes our results quite general. With both Einstein-Hilbert and
Gauss-Bonnet contributions in play, the cases with $D=1$ and $D=2$ have
different dynamics due to the different structure of the equations of motion.
We analytically study equations of motion in both cases and describe all
possible regimes. It is demonstrated that $D=1$ case does not have physically
viable regimes while $D=2$ has smooth transition from high-energy Kasner to
anisotropic exponential regime. This transition occurs for two ranges of
$\alpha$ and $\Lambda$: $\alpha > 0$, $\Lambda > 0$ with $\alpha \Lambda
\leqslant 1/2$ and $\alpha < 0$, $\Lambda > 0$ with $\alpha\Lambda < -3/2$. For
the latter case if $\alpha\Lambda = -3/2$, extra dimensional part has $h\to 0$
and so the size of extra dimensions (in the sense of the scale factor) is
reaching constant value. We report substantial differences between $D=1$ and
$D=2$ cases and between these cases and their vacuum counterparts, describe
features of the cases under study and discuss the origin of the differences.


title: Spark Parameter Tuning via Trial-and-Error

abstract:
  Spark has been established as an attractive platform for big data analysis,
since it manages to hide most of the complexities related to parallelism, fault
tolerance and cluster setting from developers. However, this comes at the
expense of having over 150 configurable parameters, the impact of which cannot
be exhaustively examined due to the exponential amount of their combinations.
The default values allow developers to quickly deploy their applications but
leave the question as to whether performance can be improved open. In this
work, we investigate the impact of the most important of the tunable Spark
parameters on the application performance and guide developers on how to
proceed to changes to the default values. We conduct a series of experiments
with known benchmarks on the MareNostrum petascale supercomputer to test the
performance sensitivity. More importantly, we offer a trial-and-error
methodology for tuning parameters in arbitrary applications based on evidence
from a very small number of experimental runs. We test our methodology in three
case studies, where we manage to achieve speedups of more than 10 times.


title:
Integral representations for Horn's $H_2$ function and Olsson's $F_P$
  function

abstract:
  We derive some Euler type double integral representations for hypergeometric
functions in two variables. In the first part of this paper we deal with Horn's
$H_2$ function, in the second part with Olsson's $F_P$ function. Our double
integral representing the $F_P$ function is compared with the formula for the
same integral representing an $H_2$ function by M. Yoshida (Hiroshima Math. J.
10 (1980), 329-335 and M. Kita (Japan. J. Math. 18 (1992), 25-74). As specified
by Kita, their integral is defined by a homological approach. We present a
classical double integral version of Kita's integral, with outer integral over
a Pochhammer double loop, which we can evaluate as $H_2$ just as Kita did for
his integral. Then we show that shrinking of the double loop yields a sum of
two double integrals for $F_P$.


title: Corruption and botnet defense: a mean field game approach

abstract:
  Recently developed toy models for the mean-field games of corruption and
botnet defence in cyber-security with three or four states of agents are
extended to a more general mean-field-game model with $2d$ states, $d\in \N$.
  In order to tackle new technical difficulties arising from a larger
state-space we introduce new asymptotic regimes, namely small discount and
small interaction asymptotics. Moreover, the link between stationary and
time-dependent solutions is established rigorously leading to a performance of
the turnpike theory in a mean-field-game setting.


title: Higgs bundles on Sasakian manifolds

abstract:
  We extend the Donaldson-Corlette-Hitchin-Simpson correspondence between Higgs
bundles and flat connections on compact K\"ahler manifolds to compact
quasi-regular Sasakian manifolds. A particular consequence is the translation
of restrictions on K\"ahler groups proved using the
Donaldson-Corlette-Hitchin-Simpson correspondence to fundamental groups of
compact Sasakian manifolds.


title: Gauge-independent $\overline{MS}$ renormalization in the 2HDM

abstract:
  We present a consistent renormalization scheme for the CP-conserving
Two-Higgs-Doublet Model based on $\overline{MS}$ renormalization of the mixing
angles and the soft-$Z_2$-symmetry-breaking scale $M_{sb}$ in the Higgs sector.
This scheme requires to treat tadpoles fully consistently in all steps of the
calculation in order to provide gauge-independent $S$-matrix elements. We show
how bare physical parameters have to be defined and verify the gauge
independence of physical quantities by explicit calculations in a general
$R_{\xi}$-gauge. The procedure is straightforward and applicable to other
models with extended Higgs sectors. In contrast to the proposed scheme, the
$\overline{MS}$ renormalization of the mixing angles combined with popular
on-shell renormalization schemes gives rise to gauge-dependent results already
at the one-loop level. We present explicit results for electroweak NLO
corrections to selected processes in the appropriately renormalized
Two-Higgs-Doublet Model and in particular discuss their scale dependence.


title: Anderson Localisation for periodically driven systems

abstract:
  We study the persistence of localization for a strongly disordered
tight-binding Anderson model on the lattice $\mathbb{Z}^d$, periodically driven
on each site. Under two different sets of conditions, we show that Anderson
localization survives if the driving frequency is higher than some threshold
value that we determine. We discuss the implication of our results for recent
development in condensed matter physics, we compare them with the predictions
issuing from adiabatic theory, and we comment on the connexion with Mott's law,
derived within the linear response formalism.


title:
Second-Order Self-Adjoint Differential Equations Using a Conformable
  Proportional Derivative

abstract:
  In this study, linear second-order conformable differential equations using a
proportional derivative are shown to be formally self-adjoint equations with
respect to a certain inner product and the associated self-adjoint boundary
conditions. Defining a Wronskian, we establish a Lagrange identity and Abel's
formula. Several reduction-of-order theorems are given. Solutions of the
conformable second-order self-adjoint equation are then shown to be related to
corresponding solutions of a first-order Riccati equation and a related
quadratic functional and a conformable Picone identity. The first part of the
study is concluded with a comprehensive roundabout theorem relating key
equivalences among all these results. Subsequently, we establish a Lyapunov
inequality, factorizations of the second-order equation, and conclude with a
section on boundary value problems and Green's functions.


title: Self-bound droplets of a dilute magnetic quantum liquid

abstract:
  Self-bound many-body systems are formed through a balance of attractive and
repulsive forces and occur in many physical scenarios. Liquid droplets are an
example of a self-bound system, formed by a balance of the mutual attractive
and repulsive forces that derive from different components of the
inter-particle potential. It has been suggested that self-bound ensembles of
ultracold atoms should exist for atom number densities that are 10^8 times
lower than in a helium droplet, which is formed from a dense quantum liquid.
However, such ensembles have been elusive up to now because they require forces
other than the usual zero-range contact interaction, which is either attractive
or repulsive but never both. On the basis of the recent finding that an
unstable bosonic dipolar gas can be stabilized by a repulsive many-body term,
it was predicted that three-dimensional self-bound quantum droplets of magnetic
atoms should exist. Here we report the observation of such droplets in a
trap-free levitation field. We find that this dilute magnetic quantum liquid
requires a minimum, critical number of atoms, below which the liquid evaporates
into an expanding gas as a result of the quantum pressure of the individual
constituents. Consequently, around this critical atom number we observe an
interaction-driven phase transition between a gas and a self-bound liquid in
the quantum degenerate regime with ultracold atoms. These droplets are the
dilute counterpart of strongly correlated self-bound systems such as atomic
nuclei and helium droplets.


title:
The influence of the elementary charge on the canonical quantization of
  LC -circuits

abstract:
  In this paper one deals with the quantization of mesoscopic LC-circuits under
the influence of an external time dependent voltage. The canonically conjugated
variables, such as given by the electric charge and the magnetic flux, get
established by resorting to the hamiltonian equations of motion provided by
both Faraday and Kirchhoff laws . This time the discretization of the electric
charge is accounted for, so that magnetic flux operators one looks for should
proceed in terms of discrete derivatives. However, the flux operators one deals
witg are not Hermitian, which means that subsequent symmetrizations are in
order. The eigenvalues characterizing such operators cab be readily established
in terms of twisted boundary conditions. Besides the discrete Schrodinger
equation with nearest-neighbor hoppings, a nontrivial next nearest neighbor
generalization has also been established. Such issues open the way to the
derivation of persistent currents in terms of effective k-dependent
Hamiltonians. Handling the time dependent voltage within the nearest neighbor
description leadsto the derivation of dynamic localization effects in L-ring
configurations, such as discussed before by Dunlap and Kenkre The onset of the
magnetic flux quantum has also been discussed in some more detail.


title: Constructing entanglement measures for fermions

abstract:
  In this paper we describe a method for finding polynomial invariants under
Stochastic Local Operations and Classical Communication (SLOCC), for a system
of delocalized fermions shared between different parties, with global particle
number conservation as the only constraint. These invariants can be used to
construct entanglement measures for different types of entanglement in such a
system. It is shown that the invariants, and the measures constructed from
them, take a nonzero value only if the state of the system allows for the
observation of Bell-nonlocal correlations. Invariants of this kind are
constructed for systems of two and three spin-1/2 fermions and examples of
maximally entangled states are given that illustrate the different types of
entanglement distinguished by the invariants. A general condition for the
existence of SLOCC invariants and their associated measures is given as a
relation between the number of fermions, their spin, and the number of spatial
modes of the system. In addition, the effect of further constraints on the
system, including the localization of a subset of the fermions, is discussed.
Finally, a hybrid Ising-Hubbard Hamiltonian is constructed for which the
groundstate of a three site chain exhibits a high degree of entanglement at the
transition between a regime dominated by on-site interaction and a regime
dominated by Ising-interaction. This entanglement is well described by a
measure constructed by the introduced method.


title: Stabilizing effects of resistivity on low-n edge localized modes in NSTX

abstract:
  The stabilizing effects of enhanced edge resistivity on the low-n edge
localized modes (ELMs) are reported for the first time in the context of ELM
suppression in H-mode discharge due to Lithium-conditioning in the National
Spherical Torus Experiment (NSTX). Here n is the toroidal mode number. Linear
stability analysis of the corresponding experimental equilibrium suggests that
the change in the equilibrium plasma density profile alone due to
Lithium-conditioning may be insufficient for a complete suppression of ELMs.
The enhanced resistivity due to the increased effective electric charge number
Z eff after Lithium-conditioning can account for additional stabi- lization
effect necessary for full ELM suppression. Remarkably, such a stabilizing
effect of enhanced edge resistivity on the low-n ELMs only exists when
two-fluid effects are considered in the MHD model.


title:
An Empirical Biomarker-based Calculator for Autosomal Recessive
  Polycystic Kidney Disease - The Nieto-Narayan Formula

abstract:
  Autosomal polycystic kidney disease (ARPKD) is associated with progressive
enlargement of the kidneys fuelled by the formation and expansion of
fluid-filled cysts. The disease is congenital and children that do not succumb
to it during the neonatal period will, by age 10 years, more often than not,
require nephrectomy+renal replacement therapy for management of both pain and
renal insufficiency. Since increasing cystic index (CI; percent of kidney
occupied by cysts) drives both renal expansion and organ dysfunction,
management of these patients, including decisions such as elective nephrectomy
and prioritization on the transplant waitlist, could clearly benefit from
serial determination of CI. So also, clinical trials in ARPKD evaluating the
efficacy of novel drug candidates could benefit from serial determination of
CI. Although ultrasound is currently the imaging modality of choice for
diagnosis of ARPKD, its utilization for assessing disease progression is highly
limited. Magnetic resonance imaging or computed tomography, although more
reliable for determination of CI, are expensive, time-consuming and somewhat
impractical in the pediatric population. Using a well-established mammalian
model of ARPKD, we undertook a big data-like analysis of minimally- or
non-invasive serum and urine biomarkers of renal injury/dysfunction to derive a
family of equations for estimating CI. We then applied a signal averaging
protocol to distill these equations to a single empirical formula for
calculation of CI. Such a formula will eventually find use in identifying and
monitoring patients at high risk for progressing to end-stage renal disease and
aid in the conduct of clinical trials.


title: A cohesive granular material with tunable elasticity

abstract:
  By mixing glass beads with a curable polymer we create a well-defined
cohesive granular medium, held together by solidified, and hence elastic,
capillary bridges. This material has a geometry similar to a wet packing of
beads, but with an additional control over the elasticity of the bonds holding
the particles together. We show that its mechanical response can be varied over
several orders of magnitude by adjusting the size and stiffness of the bridges,
and the size of the particles. We also investigate its mechanism of failure
under unconfined uniaxial compression in combination with in situ x-ray
microtomography. We show that a broad linear-elastic regime ends at a limiting
strain of about 8%, whatever the stiffness of the agglomerate, which
corresponds to the beginning of shear failure. The possibility to finely tune
the stiffness, size and shape of this simple material makes it an ideal model
system for investigations on, for example, fracturing of porous rocks,
seismology, or root growth in cohesive porous media.


title: Phase Stability of TiO$_2$ Polymorphs from Diffusion Quantum Monte Carlo

abstract:
  Titanium dioxide, TiO$_2$, has multiple applications in catalysis, energy
conversion and memristive devices because of its electronic structure. Most of
these applications utilize the naturally existing phases: rutile, anatase and
brookite. Despite the simple form of TiO$_2$ and its wide uses, there is
long-standing disagreement between theory and experiment on the energetic
ordering of these phases that has never been resolved. We present the first
analysis of phase stability at zero temperature using the highly accurate
many-body fixed node diffusion Quantum Monte Carlo (QMC) method. We also
include the effects of temperature by calculating the Helmholtz free energy
including both internal energy and vibrational contributions from density
functional perturbation theory based quasi harmonic phonon calculations. Our
QMC calculations find that anatase is the most stable phase at zero
temperature, consistent with many previous mean-field calculations. However, at
elevated temperatures, rutile becomes the most stable phase. For all finite
temperatures, brookite is always the least stable phase.


title:
Quasi-dynamic Load and Battery Sizing and Scheduling for Stand-Alone
  Solar System Using Mixed-integer Linear Programming

abstract:
  Considering the intermittency of renewable energy systems, a sizing and
scheduling model is proposed for a finite number of static electric loads. The
model objective is to maximize solar energy utilization with and without
storage. For the application of optimal load size selection, the energy
production of a solar photovoltaic is assumed to be consumed by a finite number
of discrete loads in an off-grid system using mixed-integer linear programming.
Additional constraints are battery charge and discharge limitations and minimum
uptime and downtime for each unit. For a certain solar power profile the model
outputs optimal unit size as well as the optimal scheduling for both units and
battery charge and discharge (if applicable). The impact of different solar
power profiles and minimum up and down time constraints on the optimal unit and
battery sizes are studied. The battery size required to achieve full solar
energy utilization decreases with the number of units and with increased
flexibility of the units (shorter on and off-time). A novel formulation is
introduced to model quasi-dynamic units that gradually start and stop and the
quasi-dynamic units increase solar energy utilization. The model can also be
applied to search for the optimal number of units for a given cost function.


title: On some Lie groups containing spin group in Clifford algebra

abstract:
  In this paper we consider some Lie groups in complexified Clifford algebras.
Using relations between operations of conjugation in Clifford algebras and
matrix operations we prove isomorphisms between these groups and classical
matrix groups (symplectic, orthogonal, linear, unitary) in the cases of
arbitrary dimension and arbitrary signature. Also we obtain isomorphisms of
corresponding Lie algebras which are direct sums of subspaces of quaternion
types. Spin group is a subgroup of all considered groups and it coincides with
one of them in the cases $n\leq 5$. We present classical matrix Lie groups that
contain spin group in the case of arbitrary dimension.


title: Sliding k-Transmitters: Hardness and Approximation

abstract:
  A sliding k-transmitter in an orthogonal polygon P is a mobile guard that
travels back and forth along an orthogonal line segment s inside P. It can see
a point p in P if the perpendicular from p onto s intersects the boundary of P
at most k times. We show that guarding an orthogonal polygon P with the minimum
number of k-transmitters is NP-hard, for any fixed k>0, even if P is simple and
monotone. Moreover, we give an O(1)-approximation algorithm for this problem.