title: Physics of quantum light emitters in disordered photonic nanostructures

abstract:
  Nanophotonics focuses on the control of light and the interaction with matter
by the aid of intricate nanostructures. Typically, a photonic nanostructure is
carefully designed for a specific application and any imperfections may reduce
its performance, i.e., a thorough investigation of the role of unavoidable
fabrication imperfections is essential for any application. However, another
approach to nanophotonic applications exists where fabrication disorder is used
to induce functionalities by enhancing light-matter interaction. Disorder leads
to multiple scattering of light, which is the realm of statistical optics where
light propagation requires a statistical description. We review here the recent
progress on disordered photonic nanostructures and the potential implications
for quantum photonics devices.


title:
Disentangling the ISM phases of the dwarf galaxy NGC 4214 using [CII]
  SOFIA/GREAT observations

abstract:
  The [CII] 158 um fine structure line is one of the dominant cooling lines in
the interstellar medium (ISM) and is an important tracer of star formation.
Recent velocity-resolved studies with Herschel/HIFI and SOFIA/GREAT showed that
the [CII] line can constrain the properties of the ISM phases in star-forming
regions. The [CII] line as a tracer of star formation is particularly important
in low-metallicity environments where CO emission is weak because of the
presence of large amounts of CO-dark gas. The nearby irregular dwarf galaxy NGC
4214 offers an excellent opportunity to study an actively star-forming ISM at
low metallicity. We analyzed the spectrally resolved [CII] line profiles in
three distinct regions at different evolutionary stages of NGC 4214 with
respect to ancillary HI and CO data in order to study the origin of the [CII]
line. We used SOFIA/GREAT [CII] 158 um observations, HI data from THINGS, and
CO(2-1) data from HERACLES to decompose the spectrally resolved [CII] line
profiles into components associated with neutral atomic and molecular gas. We
use this decomposition to infer gas masses traced by [CII] under different ISM
conditions. Averaged over all regions, we associate about 46% of the [CII]
emission with the HI emission. However, we can assign only around 9% of the
total [CII] emission to the cold neutral medium (CNM). We found that about 79%
of the total molecular hydrogen mass is not traced by CO emission. On average,
the fraction of CO-dark gas dominates the molecular gas mass budget. The
fraction seems to depend on the evolutionary stage of the regions: it is
highest in the region covering a super star cluster in NGC 4214, while it is
lower in a more compact, more metal-rich region.


title: Interrogating surface length spectra and quantifying isospectrality

abstract:
  This article is about inverse spectral problems for hyperbolic surfaces and
in particular how length spectra relate to the geometry of the underlying
surface. A quantitative answer is given to the following: how many questions do
you need to ask a length spectrum to determine it completely? In answering
this, a quantitative upper bound is given on the number of isospectral but
non-isometric surfaces of a given genus.


title:
Does Distributionally Robust Supervised Learning Give Robust
  Classifiers?

abstract:
  Distributionally Robust Supervised Learning (DRSL) is necessary for building
reliable machine learning systems. When machine learning is deployed in the
real world, its performance can be significantly degraded because test data may
follow a different distribution from training data. DRSL with f-divergences
explicitly considers the worst-case distribution shift by minimizing the
adversarially reweighted training loss. In this paper, we analyze this DRSL,
focusing on the classification scenario. Since the DRSL is explicitly
formulated for a distribution shift scenario, we naturally expect it to give a
robust classifier that can aggressively handle shifted distributions. However,
surprisingly, we prove that the DRSL just ends up giving a classifier that
exactly fits the given training distribution, which is too pessimistic. This
pessimism comes from two sources: the particular losses used in classification
and the fact that the variety of distributions to which the DRSL tries to be
robust is too wide. Motivated by our analysis, we propose simple DRSL that
overcomes this pessimism and empirically demonstrate its effectiveness.


title: On Maximum Induced Matching Numbers of Special Grids

abstract:
  A subset $M$ of the edge set of a graph $G$ is an induced matching of $G$ if
given any two $e_1,e_2 \in M$, none of the vertices on $e_1$ is adjacent to any
of the vertices on $e_2$. Suppose that $MIM_G$, a positive integer, is the
largest possible size of $M$ in $G$, then, $M$ is the maximum induced matching,
$MIM$, of $G$ and $MIM_G$ is the maximum induced matching number of $G$. We
obtain some upper bounds for the maximum induced matching numbers of some
specific grids.


title: Inverse counting statistics based on generalized factorial cumulants

abstract:
  We propose a procedure to reconstruct characteristic features of an unknown
stochastic system from the long-time full counting statistics of some of the
system's transitions that are monitored by a detector. The full counting
statistics is conveniently parametrized by so-called generalized factorial
cumulants. Taking only a few of them as input information is sufficient to
reconstruct important features such as the lower bound of the system dimension
and the full spectrum of relaxation rates. The use of generalized factorial
cumulants reveals system dimensions and rates that are hidden for ordinary
cumulants. We illustrate the inverse counting-statistics procedure for two
model systems: a single-level quantum dot in a Zeeman field and a
single-electron box subjected to sequential and Andreev tunneling.


title: Gravimetric estimation of the E\"otv\"os components

abstract:
  The elements of the E\"otv\"os matrix are useful for various geodetic
applications, such as the interpolation of the elements of the deflection of
the vertical, the determination of gravity anomalies and the determination of
geoid heights. A torsion balance instrument is customarily used for the
determination of the E\"otv\"os components. In this work, we show that it is
possible to estimate the E\"otv\"os components, at a point on the physical
surface of the Earth, using gravity measurements at three nearby points,
comprising a very small network. In the first part, we present the method in
detail, while in the second part we demonstrate a numerical example. We
conclude that this method is able to estimate the elements of the E\"otv\"os
matrix with satisfactory accuracy.


title:
Efficient spectral computation of the stationary states of rotating
  Bose-Einstein condensates by the preconditioned nonlinear conjugate gradient
  method

abstract:
  We propose a preconditioned nonlinear conjugate gradient method coupled with
a spectral spatial dis-cretization scheme for computing the ground states (GS)
of rotating Bose-Einstein condensates (BEC), modeled by the Gross-Pitaevskii
Equation (GPE). We first start by reviewing the classical gradient flow (also
known as imaginary time (IMT)) method which considers the problem from the PDE
standpoint, leading to numerically solve a dissipative equation. Based on this
IMT equation, we analyze the forward Euler (FE), Crank-Nicolson (CN) and the
classical backward Euler (BE) schemes for linear problems and recognize
classical power iterations, allowing us to derive convergence rates. By
considering the alternative point of view of minimization problems, we propose
the preconditioned gradient (PG) and conjugate gradient (PCG) methods for the
GS computation of the GPE. We investigate the choice of the preconditioner,
which plays a key role in the acceleration of the convergence process. The
performance of the new algorithms is tested in 1D, 2D and 3D. We conclude that
the PCG method outperforms all the previous methods, most particularly for 2D
and 3D fast rotating BECs, while being simple to implement.


title:
Total correlations of the diagonal ensemble as a generic indicator for
  ergodicity breaking in quantum systems

abstract:
  The diagonal ensemble is the infinite time average of a quantum state
following unitary dynamics. In analogy to the time average of a classical phase
space dynamics, it is intimately related to the ergodic properties of the
quantum system giving information on the spreading of the initial state in the
eigenstates of the Hamiltonian. In this work we apply a concept from quantum
information, known as total correlations, to the diagonal ensemble. Forming an
upper-bound on the multipartite entanglement, it quantifies the combination of
both classical and quantum correlations in a mixed state. We generalize the
total correlations of the diagonal ensemble to more general $\alpha$-Renyi
entropies and focus on the the cases $\alpha=1$ and $\alpha=2$ with further
numerical extensions in mind. Here we show that the total correlations of the
diagonal ensemble is a generic indicator of ergodicity breaking, displaying a
sub-extensive behaviour when the system is ergodic. We demonstrate this by
investigating its scaling in a range of spin chain models focusing not only on
the cases of integrability breaking but also emphasize its role in
understanding the transition from an ergodic to a many body localized phase in
systems with disorder or quasi-periodicity.


title:
Reinforcement Learning Approach for Parallelization in Filters
  Aggregation Based Feature Selection Algorithms

abstract:
  One of the classical problems in machine learning and data mining is feature
selection. A feature selection algorithm is expected to be quick, and at the
same time it should show high performance. MeLiF algorithm effectively solves
this problem using ensembles of ranking filters. This article describes two
different ways to improve MeLiF algorithm performance with parallelization.
Experiments show that proposed schemes significantly improves algorithm
performance and increase feature selection quality.


title: On a limit behavior of a random walk with modifications at zero

abstract:
  We consider the limit behavior of a one-dimensional random walk with unit
jumps whose transition probabilities are modified every time the walk hits
zero. The invariance principle is proved in the scheme of series where the size
of modifications depends on the number of series. For the natural scaling of
time and space arguments the limit process is (i) a Brownian motion if
modifications are "small", (ii) a linear motion with a random slope if
modifications are "large", and (iii) the limit process satisfies an SDE with a
local time of unknown process in a drift if modifications are "moderate".


title: Low-effort place recognition with WiFi fingerprints using deep learning

abstract:
  Using WiFi signals for indoor localization is the main localization modality
of the existing personal indoor localization systems operating on mobile
devices. WiFi fingerprinting is also used for mobile robots, as WiFi signals
are usually available indoors and can provide rough initial position estimate
or can be used together with other positioning systems. Currently, the best
solutions rely on filtering, manual data analysis, and time-consuming parameter
tuning to achieve reliable and accurate localization. In this work, we propose
to use deep neural networks to significantly lower the work-force burden of the
localization system design, while still achieving satisfactory results.
Assuming the state-of-the-art hierarchical approach, we employ the DNN system
for building/floor classification. We show that stacked autoencoders allow to
efficiently reduce the feature space in order to achieve robust and precise
classification. The proposed architecture is verified on the publicly available
UJIIndoorLoc dataset and the results are compared with other solutions.


title: Worst-case Prediction Performance Analysis of the Kalman Filter

abstract:
  In this paper, we study the prediction performance of the Kalman filter (KF)
in a worst-case, minimax setting as studied in online machine learning,
information - and game theory. The aim is to predict the sequence of
observations almost as well as the best reference predictor (comparator)
sequence in a comparison class. We prove worst-case bounds on the cumulative
squared prediction errors using a priori knowledge about the complexity of
reference predictor sequence. In fact, the performance of the KF is derived as
a function of the performance of the best reference predictor and the total
amount of drift occurs in the schedule of the best comparator.


title:
Linear absorption coefficient of in-plane graphene on a silicon
  microring resonator

abstract:
  We demonstrate that linear absorption coefficient (LAC) of a graphene-silicon
hybrid waveguide (GSHW) is determined by the optical transmission spectra of a
graphene coated symmetrically coupled add-drop silicon microring resonator
(SC-ADSMR), of which the value is around 0.23 dB/um. In contrast to the
traditional cut-back method, the measured results are not dependent on the
coupling efficiency of the fiber tip and the waveguide. Moreover, precision
evaluation of graphene coated silicon microring resonator (SMR) is crucial for
the optoelectronic devices targeting for compact footprint and low power
consumption.


title:
Supervisory Output Prediction for Bilinear Systems by Reinforcement
  Learning

abstract:
  Online output prediction is an indispensable part of any model predictive
control implementation, especially when simplifications of the underlying
physical model have been considered and/or the operating conditions change
quite often. Furthermore, the selection of an output prediction model is
strongly related to the data available, while designing/altering the data
collection process may not be an option. Thus, in several scenarios, selecting
the most appropriate prediction model needs to be performed during runtime. To
this end, this paper introduces a supervisory output prediction scheme,
tailored specifically for input-output stable bilinear systems, that intends on
automating the process of selecting the most appropriate prediction model
during runtime. The selection process is based upon a reinforcement-learning
scheme, where prediction models are selected according to their prior
prediction performance. An additional selection process is concerned with
appropriately partitioning the control-inputs' domain in order to also allow
for switched-system approximations of the original bilinear dynamics. We show
analytically that the proposed scheme converges (in probability) to the best
model and partition. We finally demonstrate these properties through
simulations of temperature prediction in residential buildings.


title:
Reinforcement-based Simultaneous Algorithm and its Hyperparameters
  Selection

abstract:
  Many algorithms for data analysis exist, especially for classification
problems. To solve a data analysis problem, a proper algorithm should be
chosen, and also its hyperparameters should be selected. In this paper, we
present a new method for the simultaneous selection of an algorithm and its
hyperparameters. In order to do so, we reduced this problem to the multi-armed
bandit problem. We consider an algorithm as an arm and algorithm
hyperparameters search during a fixed time as the corresponding arm play. We
also suggest a problem-specific reward function. We performed the experiments
on 10 real datasets and compare the suggested method with the existing one
implemented in Auto-WEKA. The results show that our method is significantly
better in most of the cases and never worse than the Auto-WEKA.


title:
Adopting the FAB-MAP algorithm for indoor localization with WiFi
  fingerprints

abstract:
  Personal indoor localization is usually accomplished by fusing information
from various sensors. A common choice is to use the WiFi adapter that provides
information about Access Points that can be found in the vicinity.
Unfortunately, state-of-the-art approaches to WiFi-based localization often
employ very dense maps of the WiFi signal distribution, and require a
time-consuming process of parameter selection. On the other hand, camera images
are commonly used for visual place recognition, detecting whenever the user
observes a scene similar to the one already recorded in a database. Visual
place recognition algorithms can work with sparse databases of recorded scenes
and are in general simple to parametrize. Therefore, we propose a WiFi-based
global localization method employing the structure of the well-known FAB-MAP
visual place recognition algorithm. Similarly to FAB-MAP our method uses
Chow-Liu trees to estimate a joint probability distribution of re-observation
of a place given a set of features extracted at places visited so far. However,
we are the first who apply this idea to recorded WiFi scans instead of visual
words. The new method is evaluated on the UJIIndoorLoc dataset used in the
EvAAL competition, allowing fair comparison with other solutions.


title:
The hot Jupiter of the magnetically-active weak-line T Tauri star V830
  Tau

abstract:
  We report results of an extended spectropolarimetric and photometric
monitoring of the weak-line T Tauri star V830 Tau and its recently-detected
newborn close-in giant planet. Our observations, carried out within the MaTYSSE
programme, were spread over 91d, and involved the ESPaDOnS and Narval
spectropolarimeters linked to the 3.6m Canada-France-Hawaii, the 2m Bernard
Lyot and the 8-m Gemini-North Telescopes. Using Zeeman-Doppler Imaging, we
characterize the surface brightness distributions, magnetic topologies and
surface differential rotation of V830 Tau at the time of our observations, and
demonstrate that both distributions evolve with time beyond what is expected
from differential rotation. We also report that near the end of our
observations, V830 Tau triggered one major flare and two weaker precursors,
showing up as enhanced red-shifted emission in multiple spectral activity
proxies. With 3 different filtering techniques, we model the radial velocity
(RV) activity jitter (of semi-amplitude 1.2km/s) that V830 Tau generates,
successfully retrieve the 68m/s RV planet signal hiding behind the jitter,
further confirm the existence of V830 Tau b and better characterize its orbital
parameters. We find that the method based on Gaussian-process regression
performs best thanks to its higher ability at modelling not only the activity
jitter, but also its temporal evolution over the course of our observations,
and succeeds at reproducing our RV data down to a rms precision of 35m/s. Our
result provides new observational constraints on scenarios of star / planet
formation and demonstrates the scientific potential of large-scale searches for
close-in giant planets around T Tauri stars.


title:
Existence and concentration of solution for a non-local regional
  Schr\"odinger equation with competing potentials

abstract:
  In this paper, we study the existence and concentration phenomena of
solutions for the following non-local regional Schr\"odinger equation $$
\left\{ \begin{array}{l} \epsilon^{2\alpha}(-\Delta)_\rho^{\alpha} u + Q(x)u =
K(x)|u|^{p-1}u,\;\;\mbox{in}\;\; \mathbb{R}^n,\\ u\in H^{\alpha}(\mathbb{R}^n)
\end{array} \right. $$ where $\epsilon$ is a positive parameter, $0< \alpha <
1$, $1<p<\frac{n+2\alpha}{n-2\alpha}$, $n>2\alpha$; $(-\Delta)_{\rho}^{\alpha}$
is a variational version of the regional fractional Laplacian, whose range of
scope is a ball with radius $\rho (x)>0$, $\rho, Q, K$ are competing functions.
We study the existence of ground state and we analyze the behavior of
semi-classical solutions as $\epsilon \to 0$.


title: Theoretical photo-disintegration of $^{16}$O

abstract:
  The photodisintegration of $^{16}$O is predicted to be dominated by $E$2
excitation in the vicinity of the $\alpha$-particle threshold.
  The reaction rates of $^{12}$C($\alpha$,$\gamma$)$^{16}$O are expected to be
determined from this reaction.


title:
Existence and multiplicity of solutions for a nonlinear Schr\"odinger
  equation with non-local regional diffusion

abstract:
  In this article we are interested in the following non-linear Schr\"odinger
equation with non-local regional diffusion $$
(-\Delta)_{\rho_\epsilon}^{\alpha}u + u = f(u) \hbox{ in } \mathbb{R}^n, \quad
u \in H^\alpha(\mathbb{R}^n), \qquad\qquad(P_\epsilon) $$ where $\epsilon >0$,
$0< \alpha < 1$, $(-\Delta)_{\rho_\epsilon}^{\alpha}$ is a variational version
of the regional laplacian, whose range of scope is a ball with radius
$\rho_\epsilon(x)=\rho(\epsilon x)>0$, where $\rho$ is a continuous function.
We give general conditions on $\rho$ and $f$ which assure the existence and
multiplicity of solution for $(P_\epsilon)$.


title: Domain walls and ferroelectric reversal in corundum derivatives

abstract:
  Domain walls are the topological defects that mediate polarization reversal
in ferroelectrics, and they may exhibit quite different geometric and
electronic structures compared to the bulk. Therefore, a detailed atomic-scale
understanding of the static and dynamic properties of domain walls is of
pressing interest. In this work, we use first-principles methods to study the
structures of $180^{\circ}$ domain walls, both in their relaxed state and along
the ferroelectric reversal pathway, in ferroelectrics belonging to the family
of corundum derivatives. Our calculations predict their orientation, formation
energy, and migration energy, and also identify important couplings between
polarization, magnetization, and chirality at the domain walls. Finally, we
point out a strong empirical correlation between the height of the domain-wall
mediated polarization reversal barrier and the local bonding environment of the
mobile $A$ cations as measured by bond valence sums. Our results thus provide
both theoretical and empirical guidance to future searches for ferroelectric
candidates in materials of the corundum derivative family.


title: On the perfection of schemes

abstract:
  This is a chiefly expository paper on the subject of the title which, in our
view, has not received a detailed treatment in the literature which is
commensurate with its importance. We expect the results presented here to be
useful in a number of contexts. For example, several of them will be applied in
a forthcoming paper by the authors.


title:
Real-Time Visual Place Recognition for Personal Localization on a Mobile
  Device

abstract:
  The paper presents an approach to indoor personal localization on a mobile
device based on visual place recognition. We implemented on a smartphone two
state-of-the-art algorithms that are representative to two different approaches
to visual place recognition: FAB-MAP that recognizes places using individual
images, and ABLE-M that utilizes sequences of images. These algorithms are
evaluated in environments of different structure, focusing on problems commonly
encountered when a mobile device camera is used. The conclusions drawn from
this evaluation are guidelines to design the FastABLE system, which is based on
the ABLE-M algorithm, but introduces major modifications to the concept of
image matching. The improvements radically cut down the processing time and
improve scalability, making it possible to localize the user in long image
sequences with the limited computing power of a mobile device. The resulting
place recognition system compares favorably to both the ABLE-M and the FAB-MAP
solutions in the context of real-time personal localization.


title:
Private Information Retrieval from Coded Databases with Colluding
  Servers

abstract:
  We present a general framework for Private Information Retrieval (PIR) from
arbitrary coded databases, that allows one to adjust the rate of the scheme
according to the suspected number of colluding servers. If the storage code is
a generalized Reed-Solomon code of length n and dimension k, we design PIR
schemes which simultaneously protect against t colluding servers and provide
PIR rate 1-(k+t-1)/n, for all t between 1 and n-k. This interpolates between
the previously studied cases of t=1 and k=1 and asymptotically achieves the
known capacity bounds in both of these cases, as the size of the database
grows.


title:
A note on Reed's Conjecture about $\omega$, $\Delta$ and $\chi$ with
  respect to vertices of high degree

abstract:
  Reed conjectured that for every graph, $\chi \leq \left \lceil \frac{\Delta +
\omega + 1}{2} \right \rceil$ holds, where $\chi$, $\omega$ and $\Delta$ denote
the chromatic number, clique number and maximum degree of the graph,
respectively. We develop an algorithm which takes a hypothetical counterexample
as input. The output discloses some hidden structures closely related to high
vertex degrees. Consequently, we deduce two graph classes where Reed's
Conjecture holds: One contains all graphs in which the vertices of degree at
least $5$ form a stable set. The other contains all graphs in which every
induced cycle of odd length contains a vertex of at most degree 3.


title:
A Fully Convolutional Neural Network based Structured Prediction
  Approach Towards the Retinal Vessel Segmentation

abstract:
  Automatic segmentation of retinal blood vessels from fundus images plays an
important role in the computer aided diagnosis of retinal diseases. The task of
blood vessel segmentation is challenging due to the extreme variations in
morphology of the vessels against noisy background. In this paper, we formulate
the segmentation task as a multi-label inference task and utilize the implicit
advantages of the combination of convolutional neural networks and structured
prediction. Our proposed convolutional neural network based model achieves
strong performance and significantly outperforms the state-of-the-art for
automatic retinal blood vessel segmentation on DRIVE dataset with 95.33%
accuracy and 0.974 AUC score.


title: Caratheodory-Tchakaloff Subsampling

abstract:
  We present a brief survey on the compression of discrete measures by
Caratheodory-Tchakaloff Subsampling, its implementation by Linear or Quadratic
Programming and the application to multivariate polynomial Least Squares. We
also give an algorithm that computes the corresponding Caratheodory-Tchakaloff
(CATCH) points and weights for polynomial spaces on compact sets and manifolds
in 2D and 3D.


title: Unifying left-right symmetry and 331 electroweak theories

abstract:
  We propose a realistic theory based on the $\mathrm{SU(3)_c \otimes SU(3)_L
\otimes SU(3)_R \otimes U(1)_{X}}$ gauge group which requires the number of
families to match the number of colors. In the simplest realization neutrino
masses arise from the canonical seesaw mechanism and their smallness correlates
with the observed V-A nature of the weak force. Depending on the symmetry
breaking path to the Standard Model one recovers either a left-right symmetric
theory or one based on the $\mathrm{SU(3)_c \otimes SU(3)_L \otimes U(1)}$
symmetry as the "next" step towards new physics.


title: Singular Riemannian foliations and their quadratic basic polynomials

abstract:
  We present a new link between the Invariant Theory of infinitesimal singular
Riemannian foliations and Jordan algebras. This, together with an inhomogeneous
version of Weyl's First Fundamental Theorems, provides a characterization of
the recently discovered Clifford foliations in terms of basic polynomials. This
link also yields new structural results about infinitesimal foliations, such as
the existence of non-trivial symmetries.


title: A practical method for computing with piecewise Chebyshevian splines

abstract:
  A piecewise Chebyshevian spline space is good for design when it possesses a
B-spline basis and this property is preserved under knot insertion. The
interest in such kind of spaces is justified by the fact that, similarly as for
polynomial splines, the related parametric curves exhibit the desired
properties of convex hull inclusion, variation diminution and intuitive
relation between the curve shape and the location of the control points. For a
good-for-design space, in this paper we construct a set of functions, called
transition functions, which allow for efficient computation of the B-spline
basis, even in the case of nonuniform and multiple knots. Moreover, we show how
the spline coefficients of the representations associated with a refined knot
partition and with a raised order can conveniently be expressed by means of
transition functions. This result allows us to provide effective procedures
that generalize the classical knot insertion and degree raising algorithms for
polynomial splines. We further discuss how the approach can straightforwardly
be generalized to deal with geometrically continuous piecewise Chebyshevian
splines as well as with splines having section spaces of different dimensions.
From a numerical point of view, we show that the proposed evaluation method is
easier to implement and has higher accuracy than other existing algorithms.


title: Cohomological dimensions of universal cosovereign Hopf algebras

abstract:
  We compute the Hochschild and Gerstenhaber-Schack cohomological dimensions of
the universal cosovereign Hopf algebras, when the matrix of parameters is a
generic asymmetry. Our main tools are considerations on the cohomologies of
free product of Hopf algebras, and on the invariance of the cohomological
dimensions under graded twisting by a finite abelian group.


title:
On the graded dual numbers, arcs, and non-crossing partitions of the
  integers

abstract:
  We give a combinatorial model for the bounded derived category of graded
modules over the dual numbers in terms of arcs on the integer line with a point
at infinity. Using this model we describe the lattice of thick subcategories of
the bounded derived category, and of the perfect complexes, in terms of
non-crossing partitions. We also make some comments on the symmetries of these
lattices, exceptional collections, and the analogous problem for the unbounded
derived category.


title: Continuous Hands-off Control by CLOT Norm Minimization

abstract:
  In this paper, we consider hands-off control via minimization of the CLOT
(Combined L-One and Two) norm. The maximum hands-off control is the L0-optimal
(or the sparsest) control among all feasible controls that are bounded by a
specified value and transfer the state from a given initial state to the origin
within a fixed time duration. In general, the maximum hands-off control is a
bang-off-bang control taking values of +1, -1, and 0. For many real
applications, such discontinuity in the control is not desirable. To obtain a
continuous but still relatively sparse control, we propose to use the CLOT
norm, a convex combination of L1 and L2 norms. We show by numerical simulation
that the CLOT control is continuous and much sparser (i.e. has longer time
duration on which the control takes 0) than the conventional EN (elastic net)
control, which is a convex combination of L1 and squared L2 norms.


title: Data-driven Structured Realization

abstract:
  We present a framework for constructing structured realizations of linear
dynamical systems having transfer functions of the form $C(\sum_{k=1}^K
h_k(s)A_k)^{-1}B$ where $h_1,h_2,\ldots,h_K$ are prescribed functions that
specify the surmised structure of the model. Our construction is data-driven in
the sense that an interpolant is derived entirely from measurements of a
transfer function. Our approach extends the Loewner realization framework to
more general system structure that includes second-order (and higher) systems
as well as systems with internal delays. Numerical examples demonstrate the
advantages of this approach.


title:
Electroweak baryogenesis and gravitational waves from a real scalar
  singlet

abstract:
  We consider a real scalar singlet field which provides a strong first-order
electroweak phase transition via its coupling to the Higgs boson, and gives a
$CP$ violating contribution on the top quark mass via a dimension-6 operator.
We study the correlation between the baryon-to-entropy ratio produced by
electroweak baryogenesis, and the gravitational wave signal from the
electroweak phase transition. We show that future gravitational wave
experiments can test, in particular, the region of the model parameter space
where the observed baryon-to-entropy ratio can be obtained even if the new
physics scale, which is explicit in the dimension-6 operator, is high.


title:
Oscillation Maps in the Broadband Radio Spectrum of the 1 August 2010
  Event

abstract:
  We search for indications of waves in the 25-2000 MHz radio spectrum of the 1
August 2010 event (SOL2010-08-01T08:57:00L075C013), where fast propagating
waves in the solar corona with the periods of 181, 69, and 40 seconds were
detected in UV observations. Using the wavelet technique we construct a new
type of map of oscillations for selected periods in the whole domain of the
radio spectrum. While the oscillation with the period of 181 seconds was
recognized in the whole 25-2000 MHz radio spectrum, oscillations with periods
of 69 and 40 seconds were confirmed only in the 250-870 MHz frequency range. In
the 800-2000 MHz range we found periods of 50 and 80 seconds. Moreover, in the
250-870 MHz frequency range, the oscillation with the period of about 420
seconds was detected. We also made maps of phases of the 181-second
oscillations in order to analyze their frequency drift. At the beginning of the
radio event, in the 2000-500 MHz frequency range the phase of the 181-second
oscillation drifts towards lower frequencies. On the other hand, at frequencies
25-500 MHz we found that the phase is nearly synchronous. While the phase drift
at higher frequencies can be interpreted as being caused by the UV wave, the
synchronization of the phase on lower frequencies is explained by the
fast-electron beams, whose acceleration is modulated by the UV wave. Owing to
this modulation, the electron beams are accelerated with the period of the UV
wave (181 seconds). These beams propagate upwards through the solar corona and
generate the 25-500 MHz radio emission with the 181-second period. Due to high
beam velocity (~c/3, where c is the light speed) the 25-500 MHz radio emission,
corresponding to a large interval of heights in the solar corona, is nearly
synchronous.


title: Quantum-disentangled liquid in the half-filled Hubbard model

abstract:
  We investigate the existence of quantum disentangled liquid (QDL) states in
the half-filled Hubbard model on bipartite lattices. In the one dimensional
case we employ a combination of integrability and strong coupling expansion
methods to argue that there are indeed finite energy-density eigenstates that
exhibit QDL behaviour in the sense of J. Stat. Mech. P10010 (2014). The states
exhibiting the QDL property are atypical in the sense that while their entropy
density is non-zero, it is smaller than that of thermal states at the same
energy density. We argue that for U >> t these latter thermal states exhibit a
weaker form of the QDL property, which carries over to the higher dimensional
case.


title:
The inductive entanglement classification yields ten rather than eight
  classes of four-qubit entangled states

abstract:
  Lamata et al. use an inductive approach to classify the entangled pure states
of four qubits under stochastic local operations and classical communication
(SLOCC) [PRA 75(2), 022318 (2007)]. The inductive method yields a priori ten
different entanglement superclasses, of which they discard three as empty. One
of the remaining superclasses is split in two, resulting in eight superclasses
of genuine four-qubit entanglement.
  Here, we show that two of the three discarded superclasses are in fact
non-empty and should have been retained. We give explicit expressions for the
canonical states for those superclasses, up to SLOCC and qubit permutations.
Furthermore, we confirm that the third discarded superclass is indeed empty,
yielding a total of ten superclasses of genuine four-qubit entanglement under
the inductive classification scheme.


title:
Higher order moments, cumulants, and spectra of continuous quantum noise
  measurements

abstract:
  We present general quantum mechanical expressions for higher order moments,
cumulants, and spectra of continuously measured quantum systems with
applications in spin noise spectroscopy, quantum transport, and measurement
theory in general. Starting from the so-called stochastic master equation of
continuous measurement theory, we find that the leading orders of the
fluctuating detector output $z(t)$ with respect to the measurement strength
$\beta$ are a white shot noise background, a constant measurement offset, and
the leading order quantum noise of the measured operator $A$. Starting from
quantum expressions for the multi-time moments $\langle z(t_n)\cdots z(t_1)
\rangle$ we derive three- and four-time cumulants that are valid in all orders
of $\beta$ covering the full regime between the weak and strong measurement
limit (Zeno-limit). Intriguingly, quantum expressions for the cumulants were
found that exhibit the same simple structure as those for the moments after
introduction of only a slightly modified system propagator. Very compact
expressions for the cumulant-based third and fourth order spectra (bispectrum
and trispectrum) follow naturally. We illustrate the usefulness of higher order
spectra by treating a real world two-spin system with strong hyperfine
interaction.Moreover, spin noise spectroscopy is shown to have the potential
for investigating the transition from weak measurements to the famous quantum
Zeno regime for realistic probe laser intensities.


title: Nuclear Physics

abstract:
  Lattice QCD is making good progress toward calculating the structure and
properties of light nuclei and the forces between nucleons. These calculations
will ultimately refine the nuclear forces, particularly in the three- and
four-nucleon sector and the short-distance interactions of nucleons with
electroweak currents, and allow for a reduction of uncertainties in nuclear
many-body calculations of nuclei and their reactions. After highlighting their
importance, particularly to the Nuclear Physics and High-Energy Physics
experimental programs, I discuss the progress that has been made toward
achieving these goals and the challenges that remain.


title: Current noise generated by spin imbalance in presence of spin relaxation

abstract:
  We calculate current (shot) noise in a metallic diffusive conductor generated
by spin imbalance in the absence of a net electric current. This situation is
modeled in an idealized three-terminal setup with two biased ferromagnetic
leads (F-leads) and one normal lead (N-lead). Parallel magnetization of the
F-leads gives rise in spin-imbalance and finite shot noise at the N-lead.
Finite spin relaxation results in an increase of the shot noise, which depends
on the ratio of the length of the conductor ($L$) and the spin relaxation
length ($l_s$). For $L\gg l_s$ the shot noise increases by a factor of two and
coincides with the case of the anti-parallel magnetization of the F-leads.


title:
Optical spin noise spectroscopy: application for study of gyrotropy
  spatial correlations

abstract:
  The single scattering theory is applied to spin noise spectroscopy (SNS). The
case of two Gaussian probe beams tilted with respect to each other is analysed.
It is shown that SNS signal in this case carry information about spatial
correlations of studied gyrotropic medium.


title:
In-medium bound-state formation and inhomogeneous condensation in Fermi
  gases in a hard-wall box

abstract:
  The formation of bosonic bound states underlies the formation of a superfluid
ground state in the many-body phase diagram of ultracold Fermi gases. We study
bound-state formation in a spin- and mass-imbalanced ultracold Fermi gas
confined in a box with hard-wall boundary conditions. Because of the presence
of finite Fermi spheres, the center-of-mass momentum of the potentially formed
bound states can be finite, depending on the parameters controlling mass and
spin imbalance as well as the coupling strength. We exploit this observation to
estimate the potential location of inhomogeneous phases in the many-body phase
diagram as a function of spin- and mass imbalance as well as the box size. Our
results suggest that a hard-wall box does not alter substantially the many-body
phase diagram calculated in the thermodynamic limit. Therefore, such a box may
serve as an ideal trap potential to bring experiment and theory closely
together and facilitate the search for exotic inhomogeneous ground states.


title:
Mirabolic group, ramified Newton stratification and cohomology of
  Lubin-Tate spaces

abstract:
  In my 2009 paper at Inventiones, we determine the cohomology of Lubin-Tate
spaces globally using the comparison theorem of Berkovich by computing the
fibers at supersingular points of the perverse sheaf of vanishing cycle $\Psi$
of some Shimura variety of Kottwitz-Harris-Taylor type. The most difficult
argument deals with the control of maps of the spectral sequences computing the
sheaf cohomology of both Harris-Taylor perverse sheaves and those of $\Psi$. In
this paper, we bypass these difficulties using the classical theory of
representations of the mirabolic group and a simple geometric argument.


title:
Perturbative treatment of the non-linear q-Schr\"odinger and
  q-Klein-Gordon equations

abstract:
  Interesting nonlinear generalization of both Schr\"odinger's and
Klein-Gordon's equations have been recently advanced by Tsallis, Rego-Monteiro,
and Tsallis (NRT) in [Phys. Rev. Lett. {\bf 106}, 140601 (2011)]. There is much
current activity going on in this area. The non-linearity is governed by a real
parameter $q$. It is a fact that the ensuing non linear q-Schr\"odinger and
q-Klein-Gordon equations are natural manifestations of very high energy
phenomena, as verified by LHC-experiments. This happens for $q-$values close to
unity [Nucl. Phys. A {\bf 955}, 16 (2016), Nucl. Phys. A {\bf 948}, 19 (2016)].
It is also well known that q-exponential behavior is found in quite different
settings. An explanation for such phenomenon was given in [Physica A {\bf 388},
601 (2009)] with reference to empirical scenarios in which data are collected
via set-ups that effect a normalization plus data's pre-processing. Precisely,
the ensuing normalized output was there shown to be q-exponentially distributed
if the input data display elliptical symmetry, generalization of spherical
symmetry, a frequent situation. This makes it difficult, for q-values close to
unity, to ascertain whether one is dealing with solutions to the ordinary
Schr\"odinger equation (whose free particle solutions are exponentials, and for
which $q=1$) or with its NRT nonlinear q-generalizations, whose free particle
solutions are q-exponentials. In this work we provide a careful analysis of the
$q \sim 1$ instance via a perturbative analysis of the NRT equations.

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


title: Almost full entropy subshifts uncorrelated to the M\"obius function

abstract:
  We show that if $y=(y_n)_{n\ge 1}$ is a bounded sequence with zero average
along every infinite arithmetic progression then for every $N\ge 2$ there exist
(unilateral or bilateral) subshifts $\Sigma$ over $N$ symbols, with entropy
arbitrarily close to $\log N$, uncorrelated to $y$. In particular, for $y=\mu$
being the M\"obius function, we get that there exist subshifts as above which
satisfy the assertion of Sarnak's conjecture. The existence of positive entropy
systems uncorrelated to the M\"obius function is claimed in Sarnak's survey
\cite{sarnak} (and attributed to Bourgain), however, to our knowledge no
examples have ever been published. We fill in this gap and by the way we show
that this has nothing to do with more advanced algebraic properties (for
instance multiplicativity) of the considered sequence.


title:
First test of a high voltage feedthrough for liquid Argon TPCs connected
  to a 300 kV power supply

abstract:
  Voltages above a hundred kilo-volt will be required to generate the drift
field of future very large liquid Argon Time Projection Chambers. The most
delicate component is the feedthrough whose role is to safely deliver the very
high voltage to the cathode through the thick insulating walls of the cryostat
without compromising the purity of the argon inside. This requires a
feedthrough that is typically meters long and carefully designed to be vacuum
tight and have small heat input. Furthermore, all materials should be carefully
chosen to allow operation in cryogenic conditions. In addition, electric fields
in liquid argon should be kept below a threshold to reduce risks of discharges.
The combination of all above requirements represents significant challenges
from the design and manufacturing perspective. In this paper, we report on the
successful operation of a feedthrough satisfying all the above requirements.
The details of the feedthrough design and its manufacturing steps are provided.
Very high voltages up to unprecedented voltages of -300 kV could be applied
during long periods repeatedly. A source of instability was observed, which was
specific to the setup configuration which was used for the test and not due to
the feedthrough itself.


title:
Improved estimates of the pion-photon transition form factor in the
  $(\mathbf{1\leq Q^2\leq5})$~GeV$^\mathbf{2}$ range and their theoretical
  uncertainties

abstract:
  We consider the pion-photon transition form factor at low to intermediate
spacelike momenta within the theoretical framework of light-cone sum rules. We
derive predictions which take into account all currently known contributions
stemming from QCD perturbation theory up to the next-to-next-to-leading order
(NNLO) and by including all twist terms up to order six. In order to enable a
more detailed comparison with forthcoming high-precision data, we also estimate
the main systematic theoretical uncertainties, stemming from various sources,
and discuss their influence on the calculations --- in particular the dominant
one related to the still uncalculated part of the NNLO contribution. The
analysis addresses, in broad terms, also the role of the twist-two pion
distribution amplitude derived with different approaches.


title: The Space of Stability Conditions on the Projective Plane

abstract:
  The space of Bridgeland stability conditions on the bounded derived category
of coherent sheaves on P2 has a principle connected component Stab^\dag(P2). We
show that Stab^\dag(P2) is the union of geometric and algebraic stability
conditions. As a consequence, we give a cell decomposition for Stab^\dag (P2)
and show that Stab^\dag(P2) is contractible.


title:
A magnetostatic energy formula arising from the $L^2$-orthogonal
  decomposition of the stray field

abstract:
  A formula for the magnetostatic energy of a finite magnet is proven. In
contrast to common approaches, the new energy identity does not rely on
evaluation of a nonlocal boundary integral inside the magnet or the solution of
an equivalent Dirichlet problem. The formula is therefore computationally
efficient, which is also shown numerically. Algorithms for the simulation of
magnetic materials could benefit from incorporating the presented
representation of the energy. In addition, a natural analogue for the energy
via the magnetic induction is given. Proofs are carried out within a setting
which is suitable for common discretizations in computational micromagnetics.


title:
Lattices in almost abelian Lie groups with locally conformal K\"ahler or
  symplectic structures

abstract:
  We study the existence of lattices in almost abelian Lie groups that admit
left invariant locally conformal K\"ahler or locally conformal symplectic
structures in order to obtain compact solvmanifolds equipped with these
geometric structures. In the former case, we show that such lattices exist only
in dimension $4$, while in the latter case we provide examples of such Lie
groups admitting lattices in any even dimension.


title: Twitter Sentiment around the Earnings Announcement Events

abstract:
  We investigate the relationship between social media, Twitter in particular,
and stock market. We provide an in-depth analysis of the Twitter volume and
sentiment about the 30 companies in the Dow Jones Industrial Average index,
over a period of three years. We focus on Earnings Announcements and show that
there is a considerable difference with respect to when the announcements are
made: before the market opens or after the market closes. The two different
timings of the Earnings Announcements were already investigated in the
financial literature, but not yet in the social media. We analyze the
differences in terms of the Twitter volumes, cumulative abnormal returns, trade
returns, and earnings surprises.
  We report mixed results. On the one hand, we show that the Twitter sentiment
(the collective opinion of the users) on the day of the announcement very well
reflects the stock moves on the same day. We demonstrate this by applying the
event study methodology, where the polarity of the Earnings Announcements is
computed from the Twitter sentiment. Cumulative abnormal returns are high
(2--4\%) and statistically significant. On the other hand, we find only weak
predictive power of the Twitter sentiment one day in advance. It turns out that
it is important how to account for the announcements made after the market
closes. These after-hours announcements draw high Twitter activity immediately,
but volume and price changes in trading are observed only on the next day. On
the day before the announcements, the Twitter volume is low, and the sentiment
has very weak predictive power. A useful lesson learned is the importance of
the proper alignment between the announcements, trading and Twitter data.


title:
Building a comprehensive syntactic and semantic corpus of Chinese
  clinical texts

abstract:
  Objective: To build a comprehensive corpus covering syntactic and semantic
annotations of Chinese clinical texts with corresponding annotation guidelines
and methods as well as to develop tools trained on the annotated corpus, which
supplies baselines for research on Chinese texts in the clinical domain.
  Materials and methods: An iterative annotation method was proposed to train
annotators and to develop annotation guidelines. Then, by using annotation
quality assurance measures, a comprehensive corpus was built, containing
annotations of part-of-speech (POS) tags, syntactic tags, entities, assertions,
and relations. Inter-annotator agreement (IAA) was calculated to evaluate the
annotation quality and a Chinese clinical text processing and information
extraction system (CCTPIES) was developed based on our annotated corpus.
  Results: The syntactic corpus consists of 138 Chinese clinical documents with
47,424 tokens and 2553 full parsing trees, while the semantic corpus includes
992 documents that annotated 39,511 entities with their assertions and 7695
relations. IAA evaluation shows that this comprehensive corpus is of good
quality, and the system modules are effective.
  Discussion: The annotated corpus makes a considerable contribution to natural
language processing (NLP) research into Chinese texts in the clinical domain.
However, this corpus has a number of limitations. Some additional types of
clinical text should be introduced to improve corpus coverage and active
learning methods should be utilized to promote annotation efficiency.
  Conclusions: In this study, several annotation guidelines and an annotation
method for Chinese clinical texts were proposed, and a comprehensive corpus
with its NLP modules were constructed, providing a foundation for further study
of applying NLP techniques to Chinese texts in the clinical domain.


title: Extendability of automorphisms of K3 surfaces

abstract:
  A K3 surface $X$ over a $p$-adic field $K$ is said to have good reduction if
it admits a proper smooth model over the ring of integers of $K$. Assuming
this, we say that a subgroup $G$ of $\mathrm{Aut}(X)$ is extendable if $X$
admits a proper smooth model equipped with $G$-action (compatible with the
action on $X$). We show that $G$ is extendable if it is of finite order prime
to $p$ and acts symplectically (that is, preserves the global $2$-form on $X$).
The proof relies on birational geometry of models of K3 surfaces, and
equivariant simultaneous resolutions of certain singularities. We also give
some examples of non-extendable actions.


title: Perfect state transfer on graphs with a potential

abstract:
  In this paper we study quantum state transfer (also called quantum tunneling)
on graphs when there is a potential function on the vertex set. We present two
main results. First, we show that for paths of length greater than three, there
is no potential on the vertices of the path for which perfect state transfer
between the endpoints can occur. In particular, this answers a question raised
by Godsil in Section 20 of [8]. Second, we show that if a graph has two
vertices that share a common neighborhood, then there is a potential on the
vertex set for which perfect state transfer will occur between those two
vertices. This gives numerous examples where perfect state transfer does not
occur without the potential, but adding a potential makes perfect state
transfer possible. In addition, we investigate perfect state transfer on graph
products, which gives further examples where perfect state transfer can occur.


title:
Extending two Higgs doublet models for two-loop neutrino mass generation
  and one-loop neutrinoless double beta decay

abstract:
  We extend some two Higgs doublet models, where the Yukawa couplings for the
charged fermion mass generation only involve one Higgs doublet, by two singlet
scalars respectively carrying a singly electric charge and a doubly electric
charge. The doublet and singlet scalars together can mediate a two-loop diagram
to generate a tiny Majorana mass matrix of the standard model neutrinos.
Remarkably, the structure of the neutrino mass matrix is fully determined by
the symmetric Yukawa couplings of the doubly charged scalar to the right-handed
leptons. Meanwhile, a one-loop induced neutrinoless double beta decay can
arrive at a testable level even if the electron neutrino has an extremely small
Majorana mass. We also study other experimental constraints and implications
including some rare processes and Higgs phenomenology.


title:
Quantitative stability for hypersurfaces with almost constant mean
  curvature in the hyperbolic space

abstract:
  We provide sharp stability estimates for the Alexandrov Soap Bubble Theorem
in the hyperbolic space. The closeness to a single sphere is quantified in
terms of the dimension, the measure of the hypersurface and the radius of the
touching ball condition. As consequence we obtain a new pinching result for
hypersurfaces in the hyperbolic space.
  Our approach is based on the method of moving planes. In this context we
carefully review the method and we provide the first quantitative study in the
hyperbolic space.


title: Schwinger mechanism in linear covariant gauges

abstract:
  In this work we explore the applicability of a special gluon mass generating
mechanism in the context of the linear covariant gauges. In particular, the
implementation of the Schwinger mechanism in pure Yang-Mills theories hinges
crucially on the inclusion of massless bound-state excitations in the
fundamental nonperturbative vertices of the theory. The dynamical formation of
such excitations is controlled by a homogeneous linear Bethe-Salpeter equation,
whose nontrivial solutions have been studied only in the Landau gauge. Here,
the form of this integral equation is derived for general values of the
gauge-fixing parameter, under a number of simplifying assumptions that reduce
the degree of technical complexity. The kernel of this equation consists of
fully-dressed gluon propagators, for which recent lattice data are used as
input, and of three-gluon vertices dressed by a single form factor, which is
modelled by means of certain physically motivated Ans\"atze. The
gauge-dependent terms contributing to this kernel impose considerable
restrictions on the infrared behavior of the vertex form factor; specifically,
only infrared finite Ans\"atze are compatible with the existence of nontrivial
solutions. When such Ans\"atze are employed, the numerical study of the
integral equation reveals a continuity in the type of solutions as one varies
the gauge-fixing parameter, indicating a smooth departure from the Landau
gauge. Instead, the logarithmically divergent form factor displaying the
characteristic "zero crossing", while perfectly consistent in the Landau gauge,
has to undergo a dramatic qualitative transformation away from it, in order to
yield acceptable solutions. The possible implications of these results are
briefly discussed.


title: Upstream modulation in photoreflectance

abstract:
  Photoreflectance is used for the characterisation of semiconductor samples,
usually by sweeping the monochromatized probe beam within the energy range
comprised between the highest value set by the pump beam and the lowest
absorption threshold of the sample. There is, however, no fundamental upper
limit for the probe beam other than the limited spectral content of the source
and the responsivity of the detector. As long as the modulation mechanism
behind photoreflectance does affect the complete electronic structure of the
material under study, sweeping the probe beam upstream towards higher energies
from that of the pump source is equally effective in order to probe high energy
critical points. This fact, up to now largely overseen, is shown experimentally
in this work. E1 and E0+{\Delta}0 critical points of bulk GaAs are
unambiguously resolved using pump light of lower energy. Upstream modulation
may widen further applications of the technique.


title:
The Complex VHE And Multiwavelength Flaring Activity Of The FSRQ PKS
  1510-089 In May 2015

abstract:
  The blazar PKS 1510-089 was the first of the flat spectrum radio quasar type,
which had been detected simultaneously by a ground based Cherenkov telescope
(H.E.S.S.) and the LAT instrument on board the Fermi satellite. Given the
strong broad line region emission defining this blazar class, and the resulting
high optical depth for VHE ($E>100\,$GeV) $\gamma$-rays, it was surprising to
detect VHE emission from such an object. In May 2015, PKS 1510-089 exhibited
high states throughout the electromagnetic spectrum. Target of Opportunity
observations with the H.E.S.S. experiment revealed strong and unprecedented
variability of this source. Comparison with the lightcurves obtained with the
\textit{Fermi}-LAT in HE $\gamma$-rays ($100\,$MeV$<E<100\,$GeV) and ATOM in
the optical band shows a complex relationship between these energy bands. This
points to a complex structure of the emission region, since the one-zone model
has difficulties to reproduce the source behavior even when taking into account
absorption by ambient soft photon fields. It will be shown that the presented
results have important consequences for the explanation of FSRQ spectra and
lightcurves, since the emission region cannot be located deep inside the broad
line region as is typically assumed. Additionally, acceleration and cooling
processes must be strongly time-dependent in order to account for the observed
variability patterns.


title: Hereditary quasirandomness without regularity

abstract:
  A result of Simonovits and S\'os states that for any fixed graph $H$ and any
$\epsilon > 0$ there exists $\delta > 0$ such that if $G$ is an $n$-vertex
graph with the property that every $S \subseteq V(G)$ contains $p^{e(H)}
|S|^{v(H)} \pm \delta n^{v(H)}$ labeled copies of $H$, then $G$ is quasirandom
in the sense that every $S \subseteq V(G)$ contains $\frac{1}{2} p |S|^2 \pm
\epsilon n^2$ edges. The original proof of this result makes heavy use of the
regularity lemma, resulting in a bound on $\delta^{-1}$ which is a tower of
twos of height polynomial in $\epsilon^{-1}$. We give an alternative proof of
this theorem which avoids the regularity lemma and shows that $\delta$ may be
taken to be linear in $\epsilon$ when $H$ is a clique and polynomial in
$\epsilon$ for general $H$. This answers a problem raised by Simonovits and
S\'os.


title: CPT Symmetry Without Hermiticity

abstract:
  In the literature the $CPT$ theorem has only been established for
Hamiltonians that are Hermitian. Here we extend the $CPT$ theorem to quantum
field theories with non-Hermitian Hamiltonians. Our derivation is a quite
minimal one as it requires only the time independent evolution of scalar
products and invariance under complex Lorentz transformations. The first of
these requirements does not force the Hamiltonian to be Hermitian. Rather, it
forces its eigenvalues to either be real or to appear in complex conjugate
pairs, forces the eigenvectors of such conjugate pairs to be conjugates of each
other, and forces the Hamiltonian to admit of an antilinear symmetry. The
latter requirement then forces this antilinear symmetry to be $CPT$, with
Hermiticity of a Hamiltonian thus only being a sufficient condition for $CPT$
symmetry and not a necessary one. $CPT$ symmetry thus has primacy over
Hermiticity, and it rather than Hermiticity should be taken as a guiding
principle for constructing quantum theories. With conformal gravity being a
non-Hermitian theory, our approach allows us to construct a positive,
ghost-free norm for the theory, to thereby establish the unitarity of conformal
gravity. Since our approach allows for complex energies and decays, our work
justifies the use of the $CPT$ theorem in establishing the equality of the
lifetimes of unstable particles that are charge conjugates of each other. In
the quantum-mechanical limit where charge conjugation is separately conserved,
the key results of the $PT$ symmetry program of Bender and collaborators are
recovered.


title:
Distributed Coordinate Descent for Generalized Linear Models with
  Regularization

abstract:
  Generalized linear model with $L_1$ and $L_2$ regularization is a widely used
technique for solving classification, class probability estimation and
regression problems. With the numbers of both features and examples growing
rapidly in the fields like text mining and clickstream data analysis
parallelization and the use of cluster architectures becomes important. We
present a novel algorithm for fitting regularized generalized linear models in
the distributed environment. The algorithm splits data between nodes by
features, uses coordinate descent on each node and line search to merge results
globally. Convergence proof is provided. A modifications of the algorithm
addresses slow node problem. For an important particular case of logistic
regression we empirically compare our program with several state-of-the art
approaches that rely on different algorithmic and data spitting methods.
Experiments demonstrate that our approach is scalable and superior when
training on large and sparse datasets.


title:
Texture and Color-based Image Retrieval Using the Local Extrema Features
  and Riemannian Distance

abstract:
  A novel efficient method for content-based image retrieval (CBIR) is
developed in this paper using both texture and color features. Our motivation
is to represent and characterize an input image by a set of local descriptors
extracted at characteristic points (i.e. keypoints) within the image. Then,
dissimilarity measure between images is calculated based on the geometric
distance between the topological feature spaces (i.e. manifolds) formed by the
sets of local descriptors generated from these images. In this work, we propose
to extract and use the local extrema pixels as our feature points. Then, the
so-called local extrema-based descriptor (LED) is generated for each keypoint
by integrating all color, spatial as well as gradient information captured by a
set of its nearest local extrema. Hence, each image is encoded by a LED feature
point cloud and riemannian distances between these point clouds enable us to
tackle CBIR. Experiments performed on Vistex, Stex and colored Brodatz texture
databases using the proposed approach provide very efficient and competitive
results compared to the state-of-the-art methods.


title:
The Extended Jet In AP Librae As The Source Of The VHE $\gamma$-ray
  Emission

abstract:
  Most modeling attempts of blazars use a small emission zone located close to
the central black hole in order to explain the broad-band spectral energy
distribution. Here we present a case where additionally to the small region a
$>$kpc-scale jet is required to successfully reproduce the spectrum and
especially the TeV emission, namely the low-frequeny peaked BL Lac object AP
Librae detected in the TeV domain by the H.E.S.S. experiment. Given that other
parts of the spectral energy distribution follow the characteristics implied by
the source classification, the inverse Compton component spans 10 orders of
magnitude, which cannot be reproduced by the one-zone model. Additionally,
observational constraints in both the synchrotron and inverse Compton
compoenent strongly constrain the parameters of a self-consistent model ruling
out the possibility of TeV photon production in the vicinity of the galactic
center. We discuss the possibility that the TeV radiation is emitted by highly
energetic particles in the extended, arcsec-scale jet, which has been detected
at radio and X-ray energies. The slope of the jet X-ray spectrum indicates an
inverse Compton origin, and an extrapolation to higher energies coincides with
a break feature in the $\gamma$-ray band. Modeling the jet emission with
inverse Compton scattering of the cosmic microwave background results in an
excellent fit of the radio, X-ray and TeV emission. Implications will be
discussed, such as properties of the jet, acceleration scenarios, and
observations to test the model. If confirmed, large scale jets are able to
efficiently accelerate particles and to keep relativistic speeds up to
distances of several 100kpc.


title:
The mise en scene of memristive networks: effective memory, dynamics and
  learning

abstract:
  We discuss the properties of the dynamics of purely memristive circuits using
a recently derived consistent equation for the internal memory variables of the
involved memristors. In particular, we show that the number of independent
memory states in a memristive circuit is constrained by the circuit
conservation laws, and that the dynamics preserves these symmetries by means of
a projection on the physical subspace. Moreover, we discuss other symmetries of
the dynamics under various transformations of the internal memory, and study
the linearized and strongly non-linear regimes of the dynamics. In the strongly
non-linear regime, we derive a conservation law for the internal memory
variables. We also provide a condition on the reality of the eigenvalues of
Lyapunov matrices describing the linearized dynamics close to a fixed point. We
show that the eigenvalues ca be imaginary only for mixtures of passive and
active components. Our last result concerns the weak non-linear regime. We show
that the internal memory dynamics can be interpreted as a constrained gradient
descent, and provide the functional being minimized. This latter result
provides another direct connection between memristors and learning.


title:
Singularity-free model of electrically charged fermionic particles and
  gauged Q-balls

abstract:
  We propose a model of an electrically charged fermion as a regular localized
solution of electromagnetic and spinor fields interacting with a physical
vacuum, which is phenomenologically described as a logarithmic superfluid. We
analytically study the asymptotic behavior of the solution, while obtaining its
form by numerical methods. The solution has physically plausible properties,
such as finite size, self-energy, total charge and mass. In the case of
spherical symmetry, its electric field obeys the Coulomb asymptotics at large
distances from its core. It is shown that the observable rest mass of the
fermion arises as a result of interaction of the fields with the physical
vacuum. The spinor and scalar field components of the solution decay
exponentially outside the core; therefore they can be regarded as internal
degrees of freedom which can only be probed at sufficiently large scales of
energy and momentum. Apart from conventional Fermi particles, our model can
find applications in a theory of exotic localized objects, such as U(1) gauged
Q-balls with half-integer spin.


title:
Mixed Inert Scalar Triplet Dark Matter, Radiative Neutrino Masses and
  Leptogenesis

abstract:
  The neutral component of an inert scalar multiplet with hypercharge can
provide a stable dark matter particle when its real and imaginary parts have a
splitting mass spectrum. Otherwise, a tree-level dark matter-nucleon scattering
mediated by the $Z$ boson will be much above the experimental limit. In this
paper we focus on a mixed inert scalar triplet dark matter scenario where a
complex scalar triplet with hypercharge can mix with another real scalar
triplet without hypercharge through their renormalizable coupling to the
standard model Higgs doublet. We consider three specified cases that carry most
of the relevant features of the full parameter space: (i) the neutral component
of the real triplet dominates the dark matter particle, (ii) the neutral
component of the complex triplet dominates the dark matter particle; and (iii)
the neutral components of the real and complex triplets equally constitute the
dark matter particle. Subject to the dark matter relic abundance and direct
detection constraint, we perform a systematic study on the allowed parameter
space with particular emphasis on the interplay among triplet-doublet terms and
gauge interactions. In the presence of these mixed inert scalar triplets, some
heavy Dirac fermions composed of inert fermion doublets can be utilized to
generate a tiny Majorana neutrino mass term at one-loop level and realize a
successful leptogenesis for explaining the cosmic baryon asymmetry.


title: When Canonical Quantization Fails, Here is How to Fix It

abstract:
  Following Dirac, the rules of canonical quantization include classical and
quantum contact transformations of classical and quantum phase space variables.
While arbitrary classical canonical coordinate transformations exist that is
not the case for some analogous quantum canonical coordinate transformations.
This failure is due to the rigid connection of quantum variables arising by
promoting the corresponding classical variable from a $c$-number to a
$q$-number. A different relationship of $c$-numbers and $q$-numbers in the
procedures of Enhanced Quantization shows the compatibility of all quantum
operators with all classical canonical coordinate transformations.


title:
Cubical Type Theory: a constructive interpretation of the univalence
  axiom

abstract:
  This paper presents a type theory in which it is possible to directly
manipulate $n$-dimensional cubes (points, lines, squares, cubes, etc.) based on
an interpretation of dependent type theory in a cubical set model. This enables
new ways to reason about identity types, for instance, function extensionality
is directly provable in the system. Further, Voevodsky's univalence axiom is
provable in this system. We also explain an extension with some higher
inductive types like the circle and propositional truncation. Finally we
provide semantics for this cubical type theory in a constructive meta-theory.


title: Differentiable Programs with Neural Libraries

abstract:
  We develop a framework for combining differentiable programming languages
with neural networks. Using this framework we create end-to-end trainable
systems that learn to write interpretable algorithms with perceptual
components. We explore the benefits of inductive biases for strong
generalization and modularity that come from the program-like structure of our
models. In particular, modularity allows us to learn a library of (neural)
functions which grows and improves as more tasks are solved. Empirically, we
show that this leads to lifelong learning systems that transfer knowledge to
new tasks more effectively than baselines.


title: Compact Vortices

abstract:
  We study a family of Maxwell-Higgs models, described by the inclusion of a
function of the scalar field that represent generalized magnetic permeability.
We search for vortex configurations which obey first-order differential
equations that solve the equations of motion. We first deal with the asymptotic
behavior of the field configurations, and then implement a numerical study of
the solutions, the energy density and the magnetic field. We work with the
generalized permeability having distinct profiles, giving rise to new models,
and we investigate how the vortices behave, compared with the solutions of the
corresponding standard models. In particular, we show how to build compact
vortices, that is, vortex solutions with the energy density and magnetic field
vanishing outside a compact region of the plane.


title: Igusa local zeta functions of a class of hybrid polynomials

abstract:
  In this paper, we study the Igusa's local zeta functions of a class of hybrid
polynomials with coefficients in a non-archimedean local field of positive
characteristic. Such class of hybrid polynomial was first introduced by Hauser
in 2003 to study the resolution of singularities in positive characteristic. We
prove the rationality of these local zeta functions and describe explicitly
their poles. The proof is based on Igusa's stationary phase formula.


title: Extending Two-Variable Logic on Trees

abstract:
  The finite satisfiability problem for the two-variable fragment of
first-order logic interpreted over trees was recently shown to be
ExpSpace-complete. We consider two extensions of this logic. We show that
adding either additional binary symbols or counting quantifiers to the logic
does not affect the complexity of the finite satisfiability problem. However,
combining the two extensions and adding both binary symbols and counting
quantifiers leads to an explosion of this complexity.
  We also compare the expressive power of the two-variable fragment over trees
with its extension with counting quantifiers. It turns out that the two logics
are equally expressive, although counting quantifiers do add expressive power
in the restricted case of unordered trees.


title: Direct Dark Matter Search with the CRESST II Experiment

abstract:
  The quest for the particle nature of dark matter is one of the big open
questions of modern physics. A well motivated candidate for dark matter is the
so-called WIMP - a weakly interacting massive particle. Recently several
theoretically well-motivated models with dark matter candidates in a mass
region below the WIMP mass-scale gained also a lot of interest, theoretically
and experimentally. The CRESST II experiment located at the Gran Sasso
laboratory in Italy is optimised for the detection of the elastic scattering of
these low-mass dark matter particles with ordinary matter. We show the results
obtained with an improved detector setup with increased radio purity and
enhanced background rejection and the results obtained with a dedicated
low-threshold analysis of a single conventional detector module. The limit
achieved is the most stringent limit achieved for direct dark matter
experiments in the mass region below 1.8 GeV/$c^{2}$. We will discuss the
expected performance for new small CRESST-type detectors to be used during the
next data taking phase. We conclude with an outlook of the future potential for
direct dark matter detection using further improved CRESST CaWO$_{4}$ cryogenic
detectors.


title:
ADI type preconditioners for the steady state inhomogeneous Vlasov
  equation

abstract:
  The purpose of the current work is to find numerical solutions of the steady
state inhomogeneous Vlasov equation. This problem has a wide range of
applications in the kinetic simulation of non-thermal plasmas. However, the
direct application of either time stepping schemes or iterative methods (such
as Krylov based methods like GMRES or relexation schemes) is computationally
expensive. In the former case the slowest timescale in the system forces us to
perform a long time integration while in the latter case a large number of
iterations is required. In this paper we propose a preconditioner based on an
ADI type splitting method. This preconditioner is then combined with both GMRES
and Richardson iteration. The resulting numerical schemes scale almost ideally
(i.e. the computational effort is proportional to the number of grid points).
Numerical simulations conducted show that this can result in a speedup of close
to two orders of magnitude (even for intermediate grid sizes) with respect to
the not preconditioned case. In addition, we discuss the characteristics of
these numerical methods and show the results for a number of numerical
simulations.


title:
On weakly singular and fully nonlinear travelling shallow
  capillary-gravity waves in the critical regime

abstract:
  In this Letter we consider long capillary-gravity waves described by a fully
nonlinear weakly dispersive model. First, using the phase space analysis
methods we describe all possible types of localized travelling waves. Then, we
especially focus on the critical regime, where the surface tension is exactly
balanced by the gravity force. We show that our long wave model with a critical
Bond number admits stable travelling wave solutions with a singular crest.
These solutions are usually referred to in the literature as peakons or peaked
solitary waves. They satisfy the usual speed-amplitude relation, which
coincides with Scott-Russel's empirical formula for solitary waves, while their
decay rate is the same regardless their amplitude. Moreover, they can be of
depression or elevation type independent of their speed. The dynamics of these
solutions are studied as well.


title:
Velocity integration in a multilayer neural field model of spatial
  working memory

abstract:
  We analyze a multilayer neural field model of spatial working memory,
focusing on the impact of interlaminar connectivity, spatial heterogeneity, and
velocity inputs. Models of spatial working memory typically employ networks
that generate persistent activity via a combination of local excitation and
lateral inhibition. Our model is comprised of a multilayer set of equations
that describes connectivity between neurons in the same and different layers
using an integral term. The kernel of this integral term then captures the
impact of different interlaminar connection strengths, spatial heterogeneity,
and velocity input. We begin our analysis by focusing on how interlaminar
connectivity shapes the form and stability of (persistent) bump attractor
solutions to the model. Subsequently, we derive a low-dimensional approximation
that describes how spatial heterogeneity, velocity input, and noise combine to
determine the position of bump solutions. The main impact of spatial
heterogeneity is to break the translation symmetry of the network, so bumps
prefer to reside at one of a finite number of local attractors in the domain.
With the reduced model in hand, we can then approximate the dynamics of the
bump position using a continuous time Markov chain model that describes bump
motion between local attractors. While heterogeneity reduces the effective
diffusion of the bumps, it also disrupts the processing of velocity inputs by
slowing the velocity-induced propagation of bumps. However, we demonstrate that
noise can play a constructive role by promoting bump motion transitions,
restoring a mean bump velocity that is close to the input velocity.


title: The Bufferbloat Problem over Intermittent Multi-Gbps mmWave Links

abstract:
  Due to massive available spectrum in the millimeter wave (mmWave) bands,
cellular systems in these frequencies may provides orders of magnitude greater
capacity than networks in conventional lower frequency bands. However, due to
high susceptibility to blocking, mmWave links can be extremely intermittent in
quality. This combination of high peak throughputs and intermittency can cause
significant challenges in end-to-end transport-layer mechanisms such as TCP.
This paper studies the particularly challenging problem of bufferbloat.
Specifically, with current buffering and congestion control mechanisms, high
throughput-high variable links can lead to excessive buffers incurring long
latency. In this paper, we capture the performance trends obtained while
adopting two potential solutions that have been proposed in the literature:
Active queue management (AQM) and dynamic receive window. We show that, over
mmWave links, AQM mitigates the latency but cannot deliver high throughput. The
main reason relies on the fact that the current congestion control was not
designed to cope with high data rates with sudden change. Conversely, the
dynamic receive window approach is more responsive and therefore supports
higher channel utilization while mitigating the delay, thus representing a
viable solution.


title: OpenTED Browser: Insights into European Public Spendings

abstract:
  We present the OpenTED browser, a Web application allowing to interactively
browse public spending data related to public procurements in the European
Union. The application relies on Open Data recently published by the European
Commission and the Publications Office of the European Union, from which we
imported a curated dataset of 4.2 million contract award notices spanning the
period 2006-2015. The application is designed to easily filter notices and
visualise relationships between public contracting authorities and private
contractors. The simple design allows for example to quickly find information
about who the biggest suppliers of local governments are, and the nature of the
contracted goods and services. We believe the tool, which we make Open Source,
is a valuable source of information for journalists, NGOs, analysts and
citizens for getting information on public procurement data, from large scale
trends to local municipal developments.


title:
EpistAid: Interactive Interface for Document Filtering in Evidence-based
  Health Care

abstract:
  Evidence-based health care (EBHC) is an important practice of medicine which
attempts to provide systematic scientific evidence to answer clinical
questions. In this context, Epistemonikos (www.epistemonikos.org) is one of the
first and most important online systems in the field, providing an interface
that supports users on searching and filtering scientific articles for
practicing EBHC. The system nowadays requires a large amount of expert human
effort, where close to 500 physicians manually curate articles to be utilized
in the platform. In order to scale up the large and continuous amount of data
to keep the system updated, we introduce EpistAid, an interactive intelligent
interface which supports clinicians in the process of curating documents for
Epistemonikos within lists of papers called evidence matrices. We introduce the
characteristics, design and algorithms of our solution, as well as a prototype
implementation and a case study to show how our solution addresses the
information overload problem in this area.


title:
Neural Networks Designing Neural Networks: Multi-Objective
  Hyper-Parameter Optimization

abstract:
  Artificial neural networks have gone through a recent rise in popularity,
achieving state-of-the-art results in various fields, including image
classification, speech recognition, and automated control. Both the performance
and computational complexity of such models are heavily dependant on the design
of characteristic hyper-parameters (e.g., number of hidden layers, nodes per
layer, or choice of activation functions), which have traditionally been
optimized manually. With machine learning penetrating low-power mobile and
embedded areas, the need to optimize not only for performance (accuracy), but
also for implementation complexity, becomes paramount. In this work, we present
a multi-objective design space exploration method that reduces the number of
solution networks trained and evaluated through response surface modelling.
Given spaces which can easily exceed 1020 solutions, manually designing a
near-optimal architecture is unlikely as opportunities to reduce network
complexity, while maintaining performance, may be overlooked. This problem is
exacerbated by the fact that hyper-parameters which perform well on specific
datasets may yield sub-par results on others, and must therefore be designed on
a per-application basis. In our work, machine learning is leveraged by training
an artificial neural network to predict the performance of future candidate
networks. The method is evaluated on the MNIST and CIFAR-10 image datasets,
optimizing for both recognition accuracy and computational complexity.
Experimental results demonstrate that the proposed method can closely
approximate the Pareto-optimal front, while only exploring a small fraction of
the design space.


title: Superelliptic Josephson Tunnel Junctions

abstract:
  The most important practical characteristic of a Josephson junction is its
critical current. The shape of the junction determines the specific form of the
magnetic-field dependence of the its Josephson current. Here we address the
magnetic diffraction patterns of specially shaped planar Josephson tunnel
junctions. We focus on a wide ensemble of generalized ellipses, called
superellipses, which retain the second order symmetry. We analyze the
implications of this type of isometry and derive the explicit expressions for
the threshold curves of superelliptic Josephson junctions. A detailed study is
made of their magnetic patterns with emphasis on the rate of decay of the
sidelobes amplitudes for large field amplitudes.


title: A super-Earth orbiting the nearby M-dwarf GJ 536

abstract:
  We report the discovery of a super-Earth orbiting the star GJ 536 based on
the analysis of the radial-velocity time series from the HARPS and HARPS-N
spectrographs. GJ 536 b is a planet with a minimum mass M sin $i$ of 5.36 +-
0.69 Me with an orbital period of 8.7076 +- 0.0025 days at a distance of
0.066610(13) AU, and an orbit that is consistent with circular. The host star
is the moderately quiet M1 V star GJ 536, located at 10 pc from the Sun. We
find the presence of a second signal at 43 days that we relate to stellar
rotation after analysing the time series of Ca II H&K and H alpha spectroscopic
indicators and photometric data from the ASAS archive. We find no evidence
linking the short period signal to any activity proxy. We also tentatively
derived a stellar magnetic cycle of less than 3 years.


title:
The effect of active fluctuations on the dynamics of particles, motors
  and hairpins

abstract:
  Inspired by recent experiments on the dynamics of particles and polymers in
artificial cytoskeletons and in cells, we introduce a modified Langevin
equation for a particle in an environment that is a viscoelastic medium and
that is brought out of equilibrium by the action of active fluctuations caused
by molecular motors. We show that within such a model, the motion of a free
particle crosses over from superdiffusive to subdiffusive as observed for
tracer particles in an {\it in vitro} cytoskeleton or in a cell. We investigate
the dynamics of a particle confined by a harmonic potential as a simple model
for the motion of the tethered head of kinesin-1. We find that the probability
that the head is close to its binding site on the microtubule can be enhanced
by a factor of two due to active forces. Finally, we study the dynamics of a
particle in a double well potential as a model for the dynamics of
DNA-hairpins. We show that the active forces effectively lower the potential
barrier between the two minima and study the impact of this phenomenon on the
zipping/unzipping rate.


title: Inflation in non-minimal matter-curvature coupling theories

abstract:
  We study inflationary scenarios driven by a scalar field in the presence of a
non-minimal coupling between matter and curvature. We show that the Friedmann
equation can be significantly modified when the energy density during inflation
exceeds a critical value determined by the non-minimal coupling, which in turn
may considerably modify the spectrum of primordial perturbations and the
inflationary dynamics. In particular, we show that these models are
characterised by a consistency relation between the tensor-to-scalar ratio and
the tensor spectral index that can differ significantly from the predictions of
general relativity. We also give examples of observational predictions for some
of the most commonly considered potentials and use the results of the Planck
collaboration to set limits on the scale of the non-minimal coupling.


title:
Existence of solutions to degenerate parabolic problems with two weights
  via the Hardy inequality

abstract:
  The paper concentrates on the application of the following Hardy inequality
\begin{equation*} \int_\Omega \ |\xi(x)|^p \omega_{1 }(x)dx\le \int_\Omega
|\nabla \xi(x)|^p\omega_{2 }(x)dx, \end{equation*} to the proof of existence of
weak solutions to degenerate parabolic problems of the type \begin{equation*}
\left\{\begin{array}{ll}
  u_t-div(\omega_2(x)|\nabla u|^{p-2} \nabla u )= \lambda W(x) |u|^{p-2}u&
x\in\Omega,
  u(x,0)=f(x)& x\in\Omega,
  u(x,t)=0& x\in\partial\Omega,\ t>0,\\ \end{array}\right. \end{equation*} on
an open subset $\Omega\subseteq\mathbb{R}^n$, not necessarily bounded, where
\[W(x)\leq \min\{m,\omega_1(x)\},\qquad m\in\mathbb{R}_+.\]


title: Dependence and Relevance: A probabilistic view

abstract:
  We examine three probabilistic concepts related to the sentence "two
variables have no bearing on each other". We explore the relationships between
these three concepts and establish their relevance to the process of
constructing similarity networks---a tool for acquiring probabilistic knowledge
from human experts. We also establish a precise relationship between
connectedness in Bayesian networks and relevance in probability.


title:
Using CO line ratios to trace the physical properties of molecular
  clouds

abstract:
  The carbon monoxide (CO) rotational transition lines are the most common
tracers of molecular gas within giant molecular clouds (MCs). We study the
ratio ($R_{2-1/1-0}$) between CO's first two emission lines and examine what
information it provides about the physical properties of the cloud. To study
$R_{2-1/1-0}$ we perform smooth particle hydrodynamic simulations with time
dependent chemistry (using GADGET-2), along with post-process radiative
transfer calculations on an adaptive grid (using RADMC-3D) to create synthetic
emission maps of a MC. $R_{2-1/1-0}$ has a bimodal distribution that is a
consequence of the excitation properties of each line, given that $J=1$ reaches
local thermal equilibrium (LTE) while $J=2$ is still sub-thermally excited in
the considered clouds. The bimodality of $R_{2-1/1-0}$ serves as a tracer of
the physical properties of different regions of the cloud and it helps
constrain local temperatures, densities and opacities. Additionally this
bimodal structure shows an important portion of the CO emission comes from
diffuse regions of the cloud, suggesting that the commonly used conversion
factor of $R_{2-1/1-0}\sim 0.7$ between both lines may need to be studied
further.


title: A Kirwan blow-up and trees of vector bundles

abstract:
  In the paper [MTT] a conceptuel description of compactifications of moduli
spaces of stable vector bundles on surfaces has been given, whose boundaries
consist of vector bundles on trees of sufaces. In this article a typical basic
case for the projective plane is described explicitly including the constrution
of a relevant Kirwan blow up.


title:
Optical properties (uv-vis and ftir) of gamma irradiated polymethyl
  methacrylate (pmma)

abstract:
  The effect of gamma irradiation on the UV-Vis and FTIR spectroscopy of
polymethyl methacrylate (PMMA) foils has been studied. A new absorption band is
observed in the visible spectral range due to color centers induced in the
gamma irradiated PMMA. This band shows maximum absorption (low transmission)
for 10 kGy irradiation, which decreases and saturates after 50 kGy followed by
a further increase at 500 kGy. The FTIR peaks show an increased absorption up
to ~100 kGy irradiation, which reverses for higher doses. Broad band absorption
is observed in FTIR spectra around 1600 and 3600 cm-1 due to absorption of
moisture in the irradiated samples. The reduction in the absorption intensity
at 1718 cm-1 in the irradiated PMMA (> 100 kGy) is found associated with the
demerization of the carbonyl groups. An initial increase in the absorption of
FTIR peaks with increase in the doses of irradiation is due to increased cross
linking in the PMMA structure that is induced by the absorption of moisture.
The demerization of carbonyl groups becomes dominant at higher doses of
irradiation (~500 kGy).


title:
An embedding of the universal Askey-Wilson algebra into
  $U_q(\mathfrak{sl}_2)\otimes U_q(\mathfrak{sl}_2)\otimes
  U_q(\mathfrak{sl}_2)$

abstract:
  The Askey--Wilson algebras were used to interpret the algebraic structure
hidden in the Racah--Wigner coefficients of the quantum algebra
$U_q(\mathfrak{sl}_2)$. In this paper, we display an injection of a universal
analog $\triangle_q$ of Askey--Wilson algebras into
$U_q(\mathfrak{sl}_2)\otimes U_q(\mathfrak{sl}_2)\otimes U_q(\mathfrak{sl}_2)$
behind the application. Moreover we formulate the decomposition rules for
$3$-fold tensor products of irreducible Verma $U_q(\mathfrak{sl}_2)$-modules
and of finite-dimensional irreducible $U_q(\mathfrak{sl}_2)$-modules into the
direct sums of finite-dimensional irreducible $\triangle_q$-modules.


title:
Multiscale response of ionic systems to a spatially varying electric
  field

abstract:
  In this paper the response of ionic systems subjected to a spatially varying
electric field is studied. Following the Nernst-Planck equation, two forces
driving the mass flux are present, namely, the concentration gradient and the
electric potential gradient. The mass flux due to the concentration gradient is
modelled through Fick's law, and a new constitutive relation for the mass flux
due to the potential gradient is proposed. In the regime of low screening the
response function due to the potential gradient is closely related to the ionic
conductivity. In the large screening regime, on the other hand, the response
function is governed by the charge-charge structure. Molecular dynamics
simulations are conducted and the two wave vector dependent response functions
are evaluated for models of a molten salt and an ionic liquid. In the low
screening regime the response functions show same wave vector dependency,
indicating that it is the same underlying physical processes that govern the
response. In the screening regime the wave vector dependency is very different
and, thus, the overall response is determined by different processes. This is
in agreement with the observed failure of the Nernst-Einstein relation.


title:
Signatures of Flux Tube Fragmentation and Strangeness Correlations in pp
  Collisions

abstract:
  In the fragmentation of a color flux tube in high-energy $pp$ collisions or
$e^+$-$e^-$ annihilations, the production of $q$-$\bar q$ pairs along a color
flux tube precedes the fragmentation of the tube. The local conservation laws
in the production of these $q$-$\bar q$ pairs will lead to the correlations of
adjacently produced hadrons. As a consequence, the fragmentation of a flux tube
will yield a many-hadron correlation in the form of a chain of hadrons ordered
in rapidity, with adjacent hadrons correlated in charges, flavor contents, and
azimuthal angles. It will also lead to a two-hadron angular correlation between
two hadrons with opposite charges or strangeness that is suppressed at $\Delta
\phi\sim 0$ but enhanced at $\Delta \phi\sim \pi$, within a rapidity window
$\Delta y $$\sim$$1/(dN/dy)$.


title:
Stability constants of the weak$^*$ fixed point property for the space
  $\ell_1$

abstract:
  The main aim of the paper is to study some quantitative aspects of the
stability of the weak$^*$ fixed point property for nonexpansive maps in
$\ell_1$ (shortly, $w^*$-fpp). We focus on two complementary approaches to this
topic. First, given a predual $X$ of $\ell_1$ such that the
$\sigma(\ell_1,X)$-fpp holds, we precisely establish how far, with respect to
the Banach-Mazur distance, we can move from $X$ without losing the $w^*$-fpp.
The interesting point to note here is that our estimate depends only on the
smallest radius of the ball in $\ell_1$ containing all
$\sigma(\ell_1,X)$-cluster points of the extreme points of the unit ball.
Second, we pass to consider the stability of the $w^*$-fpp in the restricted
framework of preduals of $\ell_1$. Namely, we show that every predual $X$ of
$\ell_1$ with a distance from $c_0$ strictly less than $3$, induces a weak$^*$
topology on $\ell_1$ such that the $\sigma(\ell_1,X)$-fpp holds.


title: Discovery of Orbital-Selective Cooper Pairing in FeSe

abstract:
  The superconductor FeSe is of intense interest thanks to its unusual
non-magnetic nematic state and potential for high temperature
superconductivity. But its Cooper pairing mechanism has not been determined.
Here we use Bogoliubov quasiparticle interference imaging to determine the
Fermi surface geometry of the bands surrounding the $\Gamma = (0,0)$ and
$X=(\pi / a_{Fe}, 0)$ points of FeSe, and to measure the corresponding
superconducting energy gaps. We show that both gaps are extremely anisotropic
but nodeless, and exhibit gap maxima oriented orthogonally in momentum space.
Moreover, by implementing a novel technique we demonstrate that these gaps have
opposite sign with respect to each other. This complex gap configuration
reveals the existence of orbital-selective Cooper pairing which, in FeSe, is
based preferentially on electrons from the $d_{yz}$ orbitals of the iron atoms.