title:
A New Family of Divergences Originating from Model Adequacy Tests and
  Application to Robust Statistical Inference

abstract:
  Minimum divergence methods are popular tools in a variety of statistical
applications. We consider tubular model adequacy tests, and demonstrate that
the new divergences that are generated in the process are very useful in robust
statistical inference. In particular we show that the family of $S$-divergences
can be alternatively developed using the tubular model adequacy tests; a
further application of the paradigm generates a larger superfamily of
divergences. We describe the properties of this larger class and its potential
applications in robust inference. Along the way, the failure of the first order
influence function analysis in capturing the robustness of these procedures is
also established.


title:
Joint Energy-Bandwidth Allocation for Multi-User Channels with
  Cooperating Hybrid Energy Nodes

abstract:
  In this paper, we consider the energy-bandwidth allocation for a network of
multiple users, where the transmitters each powered by both an energy harvester
and conventional grid, access the network orthogonally on the assigned
frequency band. We assume that the energy harvesting state and channel gain of
each transmitter can be predicted for $K$ time slots a priori. The different
transmitters can cooperate by donating energy to each other. The tradeoff among
the weighted sum throughput, the use of grid energy, and the amount of energy
cooperation is studied through an optimization objective which is a linear
combination of these quantities. This leads to an optimization problem with
O($N^2K$) constraints, where $N$ is the total number of transmitter-receiver
pairs, and the optimization is over seven sets of variables that denote energy
and bandwidth allocation, grid energy utilization, and energy cooperation. To
solve the problem efficiently, an iterative algorithm is proposed using the
Proximal Jacobian ADMM. The optimization sub-problems corresponding to Proximal
Jacobian ADMM steps are solved in closed form. We show that this algorithm
converges to the optimal solution with an overall complexity of O($N^2K^2$).
Numerical results show that the proposed algorithms can make efficient use of
the harvested energy, grid energy, energy cooperation, and the available
bandwidth.


title: Soft symmetry improvement of two particle irreducible effective actions

abstract:
  Two particle irreducible effective actions (2PIEAs) are valuable
non-perturbative techniques in quantum field theory; however, finite
truncations of them violate the Ward identities (WIs) of theories with
spontaneously broken symmetries. The symmetry improvement (SI) method of
Pilaftsis and Teresi attempts to overcome this by imposing the WIs as
constraints on the solution; however the method suffers from the non-existence
of solutions in linear response theory and in certain truncations in
equilibrium. Motivated by this, we introduce a new method called soft symmetry
improvement (SSI) which relaxes the constraint. Violations of WIs are allowed
but punished in a least-squares implementation of the symmetry improvement
idea. A new parameter $\xi$ controls the strength of the constraint. The method
interpolates between the unimproved ($\xi \to \infty$) and SI ($\xi \to 0$)
cases and the hope is that practically useful solutions can be found for finite
$\xi$. We study the SSI-2PIEA for a scalar O(N) model in the Hartree-Fock
approximation. We find that the method is IR sensitive: the system must be
formulated in finite volume $V$ and temperature $T=\beta^{-1}$ and the $V\beta
\to \infty$ limit taken carefully. Three distinct limits exist. Two are
equivalent to the unimproved 2PIEA and SI-2PIEA respectively, and the third is
a new limit where the WI is satisfied but the phase transition is strongly
first order and solutions can fail to exist depending on $\xi$. Further, these
limits are disconnected from each other; there is no smooth way to interpolate
from one to another. These results suggest that any potential advantages of SSI
methods, and indeed any application of (S)SI methods out of equilibrium, must
occur in finite volume.


title:
Low frequency observations of transient quasi-periodic radio emission
  from the solar atmosphere

abstract:
  We report low frequency observations of the quasi-periodic, circularly
polarized, harmonic type III radio bursts whose associated sunspot active
regions were located close to the solar limb. The measured periodicity of the
bursts at 80 MHz was $\approx$ 5.2 s and their average degree of circular
polarization ($dcp$) was $\approx 0.12$. We calculated the associated magnetic
field $B$ : (1) using the empirical relationship between the $dcp$ and $B$ for
the harmonic type III emission, and (2) from the observed quasi-periodicity of
the bursts. Both the methods result in $B \approx$ 4.2 G at the location of the
80 MHz plasma level (radial distance $r \approx 1.3~\rm R_{\odot}$) in the
active region corona.


title: Development of Radiation Hard Scintillators

abstract:
  Modern high-energy physics experiments are in ever increasing need for
radiation hard scintillators and detectors. In this regard, we have studied
various radiation-hard scintillating materials such as Polyethylene Naphthalate
(PEN), Polyethylene Terephthalate (PET), our prototype material Scintillator X
(SX) and Eljen (EJ). Scintillation and transmission properties of these
scintillators are studied using stimulated emission from a 334 nm wavelength UV
laser with PMT before and after certain amount of radiation exposure. Recovery
from radiation damage is studied over time. While the primary goal of this
study is geared for LHC detector upgrades, these new technologies could easily
be used for future experiments such as the FCC and ILC. Here we discuss the
physics motivation, recent developments and laboratory measurements of these
materials.


title: Dynamical normal modes for time-dependent Hamiltonians in two dimensions

abstract:
  We present the theory of time-dependent point transformations to find
independent dynamical normal modes for 2D systems subjected to time-dependent
control in the limit of small oscillations. The condition that determines if
the independent modes can indeed be defined is identified, and a geometrical
analogy is put forward. The results explain and unify recent work to design
fast operations on trapped ions, needed to implement a scalable
quantum-information architecture: transport, expansions, and the separation of
two ions, two-ion phase gates, as well as the rotation of an anisotropic trap
for an ion are treated and shown to be analogous to a mechanical system of two
masses connected by springs with time dependent stiffness.


title: Towards Laser Control of Open Quantum Systems: Memory Effects

abstract:
  Laser control of Open Quantum Systems (OQS) is a challenging issue as
compared to its counterpart in isolated small size molecules, basically due to
very large numbers of degrees of freedom to be accounted for. Such a control
aims at appropriately optimizing decoherence processes of a central two-level
system (a given vibrational mode, for instance) towards its environmental bath
(including, for instance, all other normal modes). A variety of applications
could potentially be envisioned, either to preserve the central system from
decaying (long duration molecular alignment or orientation, qubit decoherence
protection) or, to speed up the information flow towards the bath (efficient
charge or proton transfers in long chain organic compounds). Achieving such
controls require some quantitative measures of decoherence in relation with
memory effects in the bath response, actually given by the degree of
non-Markovianity. Characteristic decoherence rates of a Spin-Boson model are
calculated using a Nakajima-Zwanzig type master equation with converged HEOM
expansion for the memory kernel. It is shown that, by adequately tuning the
two-level transition frequency through a controlled Stark shift produced by an
external laser field, non-Markovianity can be enhanced in a continuous way
leading to a first attempt towards the control of OQS.


title: Sequent Calculi for Semi-De Morgan and De Morgan Algebras

abstract:
  A contraction-free and cut-free sequent calculus $\msf{G3SDM}$ for semi-De
Morgan algebras, and a structural-rule-free and single-succedent sequent
calculus $\msf{G3DM}$ for De Morgan algebras are developed. The cut rule is
admissible in both sequent calculi. Both calculi enjoy the decidability and
Craig interpolation. The sequent calculi are applied to prove some embedding
theorems: $\msf{G3DM}$ is embedded into $\msf{G3SDM}$ via G\"odel-Gentzen
translation. $\msf{G3DM}$ is embedded into a sequent calculus for classical
propositional logic. $\msf{G3SDM}$ is embedded into the sequent calculus
$\msf{G3ip}$ for intuitionistic propositional logic.


title:
Commissioning of CMS Forward Hadron Calorimeters with Upgraded
  Multi-anode PMTs and {\mu}TCA Readout

abstract:
  The high flux of charged particles interacting with the CMS Forward Hadron
Calorimeter PMT windows introduced a significant background for the trigger and
offline data analysis. During Long Shutdown 1, all of the original PMTs were
replaced with multi-anode, thin window photomultiplier tubes. At the same time,
the back-end electronic readout system was upgraded to {\mu}TCA readout. The
experience with commissioning and calibration of the Forward Hadron Calorimeter
is described as well as the {\mu}TCA system. The upgrade was successful and
provided quality data for Run 2 data-analysis at 13 TeV.


title:
Study of plasmonic slot waveguides with a nonlinear metamaterial core:
  semi-analytical and numerical methods

abstract:
  Two distinct models are developed to investigate the transverse magnetic
stationary solutions propagating in one-dimensional anisotropic nonlinear
plasmonic structures made from a nonlinear metamaterial core of Kerr-type
embedded between two semi-infinite metal claddings. The first model is
semi-analytical, in which we assumed that the anisotropic nonlinearity depends
only on the transverse component of the electric field and that the nonlinear
refractive index modification is small compared to the linear one. This method
allows us to derive analytically the field profiles and the nonlinear
dispersion relations in terms of the Jacobi elliptical functions. The second
model is fully numerical, it is based on the finite-element method in which all
the components of the electric field are considered in the Kerr-type
nonlinearity with no presumptions on the nonlinear refractive index change. Our
finite-element based model is valid beyond weak nonlinearity regime and
generalize the well-known single-component fixed power algorithm that is
usually used. Examples of the main cases are investigated including ones with
strong spatial nonlinear effects at low powers. Loss issues are reduced through
the use of gain medium in the nonlinear metamaterial core.


title:
Two-dimensional materials from high-throughput computational exfoliation
  of experimentally known compounds

abstract:
  We search for novel two-dimensional materials that can be easily exfoliated
from their parent compounds. Starting from 108423 unique, experimentally known
three-dimensional compounds we identify a subset of 5619 that appear layered
according to robust geometric and bonding criteria. High-throughput
calculations using van-der-Waals density-functional theory, validated against
experimental structural data and calculated random-phase-approximation binding
energies, allow to identify 1825 compounds that are either easily or
potentially exfoliable, including all that are commonly exfoliated
experimentally. In particular, the subset of 1036 easily exfoliable
cases---layered materials held together mostly by dispersion interactions and
with binding energies up to $30-35$ meV$\cdot\text{\AA}^{-2}$---provides a
wealth of novel structural prototypes and simple ternary compounds, and a large
portfolio to search materials for optimal properties. For the 258 compounds
with up to 6 atoms per primitive cell we comprehensively explore vibrational,
electronic, magnetic, and topological properties, identifying in particular 56
ferromagnetic and antiferromagnetic systems, including half-metals and
half-semiconductors.


title:
Understanding looping kinetics of a long polymer molecule in solution.
  Exact solution for delta function sink model

abstract:
  A diffusion theory for intramolecular reactions of polymer chain in dilute
solution is formulated. We give a detailed analytical expression for
calculation of rate of polymer looping in solution. The physical problem of
looping can be modeled mathematically with the use of a Smoluchowski like
equation with a Dirac delta function sink of finite strength. The solution of
this equation is expressed in terms of Laplace Transform of the Greens function
for end to end motion of the polymer in absence of the sink. We have defined
two different rate constants, the long term rate constant and the short term
rate constant. The short term rate constant and long term rate constant varies
with several parameters such as length of the polymer, bond length and the
relaxation time. The long term rate constant is independent of the initial
probability distribution.


title: Anisotropic magnetotransport in Dirac-Weyl magnetic junctions

abstract:
  We theoretically study the anisotropic magnetotransport in Dirac-Weyl
magnetic junctions where a doped ferromagnetic Weyl semimetal is sandwiched
between doped Dirac semimetals. We calculate the conductance using the Landauer
formula and find that the system exhibits extraordinarily large anisotropic
magnetoresistance (AMR). The AMR depends on the ratio of the Fermi energy and
the strength of the exchange interaction. The origin of the AMR is the shift of
the Fermi surface in the Weyl semimetal and the mechanism is completely
different from the conventional AMR originating from the spin dependent
scattering and the spin-orbit interaction.


title: Infinite and finite dimensional generalized Hilbert tensors

abstract:
  In this paper, we introduce the concept of an $m$-order $n$-dimensional
generalized Hilbert tensor $\mathcal{H}_{n}=(\mathcal{H}_{i_{1}i_{2}\cdots
i_{m}})$, $$ \mathcal{H}_{i_{1}i_{2}\cdots i_{m}}=\frac{1}{i_{1}+i_{2}+\cdots
i_{m}-m+a},\ a\in \mathbb{R}\setminus\mathbb{Z}^-;\
i_{1},i_{2},\cdots,i_{m}=1,2,\cdots,n, $$ and show that its $H$-spectral radius
and its $Z$-spectral radius are smaller than or equal to $M(a)n^{m-1}$ and
$M(a)n^{\frac{m}{2}}$, respectively, here $M(a)$ is a constant only dependent
on $a$. Moreover, both infinite and finite dimensional generalized Hilbert
tensors are positive definite for $a\geq1$. For an $m$-order infinite
dimensional generalized Hilbert tensor $\mathcal{H}_{\infty}$ with $a>0$, we
prove that $\mathcal{H}_{\infty}$ defines a bounded and positively
$(m-1)$-homogeneous operator from $l^{1}$ into $l^{p}\ (1<p<\infty)$. The upper
bounds of norm of corresponding positively homogeneous operators are obtained.


title: Overflow of a dipolar exciton trap at high magnetic fields

abstract:
  We study laterally trapped dipolar exciton ensembles in coupled GaAs quantum
wells at high magnetic fields in the Faraday configuration. In
photoluminescence experiments, we identify three magnetic field regimes. At low
fields, the exciton density is increased by a reduced charge carrier escape
from the trap, and additionally, the excitons' emission energy is corrected by
a positive diamagnetic shift. At intermediate fields, magnetic field dependent
correction terms apply which follow the characteristics of a neutral
magnetoexciton. Due to a combined effect of an increasing binding energy and
lifetime, the exciton density is roughly doubled from zero to about seven
Tesla. At the latter high field value, the charge carriers occupy only the
lowest Landau level. In this situation, the exciton trap can overflow
independently from the electrostatic depth of the trapping potential, and the
energy shift of the excitons caused by the so-called quantum confined Stark
effect is effectively compensated. Instead, the exciton energetics seem to be
driven by the magnetic field dependent renormalization of the many-body
interaction terms. In this regime, the impact of parasitic in-plane fields at
the edge of trapping potential is eliminated.


title:
How to do lexical quality estimation of a large OCRed historical Finnish
  newspaper collection with scarce resources

abstract:
  The National Library of Finland has digitized the historical newspapers
published in Finland between 1771 and 1910. This collection contains
approximately 1.95 million pages in Finnish and Swedish. Finnish part of the
collection consists of about 2.40 billion words. The National Library's Digital
Collections are offered via the digi.kansalliskirjasto.fi web service, also
known as Digi. Part of the newspaper material (from 1771 to 1874) is also
available freely downloadable in The Language Bank of Finland provided by the
FINCLARIN consortium. The collection can also be accessed through the Korp
environment that has been developed by Spr{\aa}kbanken at the University of
Gothenburg and extended by FINCLARIN team at the University of Helsinki to
provide concordances of text resources. A Cranfield style information retrieval
test collection has also been produced out of a small part of the Digi
newspaper material at the University of Tampere.
  Quality of OCRed collections is an important topic in digital humanities, as
it affects general usability and searchability of collections. There is no
single available method to assess quality of large collections, but different
methods can be used to approximate quality. This paper discusses different
corpus analysis style methods to approximate overall lexical quality of the
Finnish part of the Digi collection. Methods include usage of parallel samples
and word error rates, usage of morphological analyzers, frequency analysis of
words and comparisons to comparable edited lexical data. Our aim in the quality
analysis is twofold: firstly to analyze the present state of the lexical data
and secondly, to establish a set of assessment methods that build up a compact
procedure for quality assessment after e.g. new OCRing or post correction of
the material. In the discussion part of the paper we shall synthesize results
of our different analyses.


title: Quantum Fields and Probability

abstract:
  I review some recent work where ideas and methods from Quantum Field Theory
have proved useful in probability and vice versa. The topics discussed include
the use of Renormalization Group theory in Stochastic Partial Differential
Equations driven by space-time white noise and the use of the theory of
Gaussian Multiplicative Chaos in the study of two dimensional Liouville
Conformal Field theory.


title: A Combinatorial Solution to Non-Rigid 3D Shape-to-Image Matching

abstract:
  We propose a combinatorial solution for the problem of non-rigidly matching a
3D shape to 3D image data. To this end, we model the shape as a triangular mesh
and allow each triangle of this mesh to be rigidly transformed to achieve a
suitable matching to the image. By penalising the distance and the relative
rotation between neighbouring triangles our matching compromises between image
and shape information. In this paper, we resolve two major challenges: Firstly,
we address the resulting large and NP-hard combinatorial problem with a
suitable graph-theoretic approach. Secondly, we propose an efficient
discretisation of the unbounded 6-dimensional Lie group SE(3). To our knowledge
this is the first combinatorial formulation for non-rigid 3D shape-to-image
matching. In contrast to existing local (gradient descent) optimisation
methods, we obtain solutions that do not require a good initialisation and that
are within a bound of the optimal solution. We evaluate the proposed method on
the two problems of non-rigid 3D shape-to-shape and non-rigid 3D shape-to-image
registration and demonstrate that it provides promising results.


title:
Incompressible hydrodynamic approximation with viscous heating to the
  Boltzmann equation

abstract:
  The incompressible Navier-Stokes-Fourier system with viscous heating was
first derived from the Boltzmann equation in the form of the diffusive scaling
by Bardos-Levermore-Ukai-Yang (2008). The purpose of this paper is to justify
such an incompressible hydrodynamic approximation to the Boltzmann equation in
$L^2\cap L^\infty$ setting in a periodic box. Based on an odd-even expansion of
the solution with respect to the microscopic velocity, the diffusive
coefficients are determined by the incompressible Navier-Stokes-Fourier system
with viscous heating and the super Burnett functions. More importantly, the
remainder of the expansion is proven to decay exponentially in time via an
$L^2-L^\infty$ approach on the condition that the initial data satisfies the
mass, momentum and energy conversation laws.


title: Constructive Liouville Conformal Field Theory

abstract:
  These lectures give an introduction to a probabilistic approach to Liouville
Quantum Field Theory developed in a joint work with F. David, R. Rhodes and V.
Vargas.


title: Deep Transfer Learning for Person Re-identification

abstract:
  Person re-identification (Re-ID) poses a unique challenge to deep learning:
how to learn a deep model with millions of parameters on a small training set
of few or no labels. In this paper, a number of deep transfer learning models
are proposed to address the data sparsity problem. First, a deep network
architecture is designed which differs from existing deep Re-ID models in that
(a) it is more suitable for transferring representations learned from large
image classification datasets, and (b) classification loss and verification
loss are combined, each of which adopts a different dropout strategy. Second, a
two-stepped fine-tuning strategy is developed to transfer knowledge from
auxiliary datasets. Third, given an unlabelled Re-ID dataset, a novel
unsupervised deep transfer learning model is developed based on co-training.
The proposed models outperform the state-of-the-art deep Re-ID models by large
margins: we achieve Rank-1 accuracy of 85.4\%, 83.7\% and 56.3\% on CUHK03,
Market1501, and VIPeR respectively, whilst on VIPeR, our unsupervised model
(45.1\%) beats most supervised models.


title: Status of Experiment NEUTRINO-4 Search for Sterile Neutrino

abstract:
  In order to carry out research in the field of possible existence of a
sterile neutrino the laboratory based on SM-3 reactor (Dimitrovgrad, Russia)
was created to search for oscillations of reactor antineutrino. The prototype
of a multi-section neutrino detector with liquid scintillator volume of 350 l
was installed in the middle of 2015. It is a moveable inside the passive
shielding detector, which can be set at distance range from 6 to 11 meters from
the reactor core. Measurements of antineutrino flux at such short distances
from the reactor core are carried out with moveable detector for the first
time. The measurements with full-scale detector with liquid scintillator volume
of 3 m^3 (5x10 sections) was started only in June, 2016. The today available
data is presented in the article.


title:
Performance of Solution Processed Carbon Nanotube Field Effect
  Transistors with Graphene Electrodes

abstract:
  This work evaluates the performance of carbon nanotube field effect
transistors (CNTFET) using few layer graphene as the contact electrode
material. We present the experimental results obtained on the barrier height at
CNT graphene junction using temperature dependent IV measurements. The
estimated barrier height in our devices for both holes and electrons is close
to zero or slightly negative indicating the Ohmic contact of graphene with the
valence and conduction bands of CNTs. In addition, we also report that there is
no correlation between the barrier height and thickness of graphene.


title: A new method to index and store spatio-temporal data

abstract:
  We propose a data structure that stores, in a compressed way, object
trajectories, which at the same time, allow to efficiently response queries
without the need to decompress the data. We use a data structure, called
$k^{2}$-tree, to store the full position of all objects at regular time
intervals. For storing the positions of objects between two time instants
represented with $k^{2}$-trees, we only encode the relative movements. In order
to save space, those relative moments are encoded with only one integer,
instead of two (x,y)-coordinates. Moreover, the resulting integers are further
compressed with a technique that allows us to manipulate those movements
directly in compressed form. In this paper, we show an experimental evaluation
of this structure, which shows important savings in space and good response
times.


title:
Incremental and Fully Dynamic Subgraph Connectivity For Emergency
  Planning

abstract:
  During the last 10 years it has become popular to study dynamic graph
problems in a emergency planning or sensitivity setting: Instead of considering
the general fully dynamic problem, we only have to process a single batch
update of size $d$; after the update we have to answer queries.
  In this paper, we consider the dynamic subgraph connectivity problem with
sensitivity $d$: We are given a graph of which some vertices are activated and
some are deactivated. After that we get a single update in which the states of
up to d vertices are changed. Then we get a sequence of connectivity queries in
the subgraph of activated vertices.
  We present the first fully dynamic algorithm for this problem which has an
update and query time only slightly worse than the best decremental algorithm.
In addition, we present the first incremental algorithm which is tight with
respect to the best known conditional lower bound; moreover, the algorithm is
simple and we believe it is implementable and efficient in practice.


title:
An estimate of the magnetic field strength associated with a solar
  coronal mass ejection from low frequency radio observations

abstract:
  We report ground based, low frequency heliograph (80 MHz), spectral (85-35
MHz) and polarimeter (80 and 40 MHz) observations of drifting, non-thermal
radio continuum associated with the `halo' coronal mass ejection (CME) that
occurred in the solar atmosphere on 2013 March 15. The magnetic field strengths
($B$) near the radio source were estimated to be $B \approx 2.2 \pm 0.4$ G at
80 MHz and $B \approx 1.4 \pm 0.2$ G at 40 MHz. The corresponding radial
distances ($r$) are $r \approx 1.9~R_{\odot}$ (80 MHz) and $r \approx
2.2~R_{\odot}$ (40 MHz).


title:
Real-Time Video Super-Resolution with Spatio-Temporal Networks and
  Motion Compensation

abstract:
  Convolutional neural networks have enabled accurate image super-resolution in
real-time. However, recent attempts to benefit from temporal correlations in
video super-resolution have been limited to naive or inefficient architectures.
In this paper, we introduce spatio-temporal sub-pixel convolution networks that
effectively exploit temporal redundancies and improve reconstruction accuracy
while maintaining real-time speed. Specifically, we discuss the use of early
fusion, slow fusion and 3D convolutions for the joint processing of multiple
consecutive video frames. We also propose a novel joint motion compensation and
video super-resolution algorithm that is orders of magnitude more efficient
than competing methods, relying on a fast multi-resolution spatial transformer
module that is end-to-end trainable. These contributions provide both higher
accuracy and temporally more consistent videos, which we confirm qualitatively
and quantitatively. Relative to single-frame models, spatio-temporal networks
can either reduce the computational cost by 30% whilst maintaining the same
quality or provide a 0.2dB gain for a similar computational cost. Results on
publicly available datasets demonstrate that the proposed algorithms surpass
current state-of-the-art performance in both accuracy and efficiency.


title: Expanders with superquadratic growth

abstract:
  We will prove several expanders with exponent strictly greater than $2$. For
any finite set $A \subset \mathbb R$, we prove the following six-variable
expander results: \begin{align*} |(A-A)(A-A)(A-A)| &\gg
\frac{|A|^{2+\frac{1}{8}}}{\log^{\frac{17}{16}}|A|}, \\
\left|\frac{A+A}{A+A}+\frac{A}{A}\right| &\gg
\frac{|A|^{2+\frac{2}{17}}}{\log^{\frac{16}{17}}|A|}, \\
\left|\frac{AA+AA}{A+A}\right| &\gg \frac{|A|^{2+\frac{1}{8}}}{\log |A|}, \\
\left|\frac{AA+A}{AA+A}\right| &\gg \frac{|A|^{2+\frac{1}{8}}}{\log |A|}.
\end{align*}


title: Some elementary observations on Narayana polynomials and related topics

abstract:
  We give an elementary account of generalized Fibonacci and Lucas polynomials
whose moments are Narayana polynomials of type A and type B.


title:
Strict upper and lower bounds for quantities of interest in static
  response sensitivity analysis

abstract:
  In this paper, a goal-oriented error estimation technique for static response
sensitivity analysis is proposed based on the constitutive relation error (CRE)
estimation for finite element analysis (FEA). Strict upper and lower bounds of
various quantities of interest (QoI) that are associated with the response
sensitivity derivative fields are acquired. Numerical results are presented to
assess the strict bounding properties of the proposed technique.


title: Satellite Infall and Mass Deposition on the Galactic Centre

abstract:
  We model the infall of a 2e5 Msun satellite galaxy on to the inner 200 parsec
of our Galaxy, to test whether the satellite could perturb the gas previously
on stable orbits in the central molecular zone (CMZ), as proposed by Lang et
al. (2013). This process would have driven a large gas inflow around 10 Myr
ago, necessary to explain the past high accretion rate onto the super-massive
black hole, and the presence of young stars in the inner parsecs of the Galaxy.
Our hydrodynamical simulations show a much smaller inflow of gas, not
sufficient to produce the aforementioned effects.


title:
Light matter interaction in transition metal dichalcogenides and their
  heterostructures

abstract:
  The investigation of 2D van der Waals (vdW) materials is a vibrant, fast
moving and still growing interdisciplinary area of research. 2D vdW materials
are truly 2D crystals with strong covalent in-plane bonds and weak van der
Waals interaction between the layers with a variety of different electronic,
optical and mechanical properties. A very prominent class of 2D materials are
transition metal dichalcogenides (TMDs) and amongst them particularly the
semiconducting subclass. Their properties include bandgaps in the near-infrared
to the visible range, decent charge carrier mobility together with high
(photo-)catalytic and mechanical stability and exotic many body phenomena.
These characteristics make the materials highly attractive for both fundamental
research as well as innovative device applications. Furthermore, the materials
exhibit a strong light matter interaction providing a high sun light absorbance
of up to 15% in the monolayer limit, strong scattering cross section in Raman
experiments and access to excitonic phenomena in vdW heterostructures. This
review focuses on the light matter interaction in MoS2, WS2, MoSe2, and WSe2
that is dictated by the materials complex dielectric functions and on the
multiplicity of studying the first order phonon modes by Raman spectroscopy to
gain access to several material properties such as doping, strain, defects and
temperature. 2D materials provide an interesting platform to stack them into
vdW heterostructures without the limitation of lattice mismatch resulting in
novel devices for application but also to study exotic many body interaction
phenomena such as interlayer excitons. Future perspectives of semiconducting
TMDs and their heterostructures for applications in optoelectronic devices will
be examined and routes to study emergent fundamental problems and many-body
quantum phenomena under excitations with photons will be discussed.


title:
Some elementary observations on Narayana polynomials and related topics
  II: q-Narayana polynomials

abstract:
  We show that q-Catalan numbers, q- central binomial coefficients and q-
Narayana polynomials are moments of q-analogues of Fibonacci and Lucas
polynomials and related polynomials.


title: Mating quadratic maps with the modular group II

abstract:
  In 1994 S. Bullett and C. Penrose introduced the one complex parameter family
of $(2:2)$ holomorphic correspondences $\mathcal{F}_a$:
$$\left(\frac{aw-1}{w-1}\right)^2+\left(\frac{aw-1}{w-1}\right)\left(\frac{az+1}{z+1}\right)
+\left(\frac{az+1}{z+1}\right)^2=3$$ and proved that for every value of $a \in
[4,7] \subset \mathbb{R}$ the correspondence $\mathcal{F}_a$ is a mating
between a quadratic polynomial $Q_c(z)=z^2+c,\,\,c \in \mathbb{R}$ and the
modular group $\Gamma=PSL(2,\mathbb{Z})$. They conjectured that this is the
case for every member of the family $\mathcal{F}_a$ which has $a$ in the
connectedness locus.
  We prove here that every member of the family $\mathcal{F}_a$ which has $a$
in the connectedness locus is a mating between the modular group and an element
of the parabolic quadratic family $Per_1(1)$.


title: Elliptic curves in isogeny classes

abstract:
  We show that the distribution of elliptic curves in isogeny classes of curves
with a given value of the Frobenius trace $t$ becomes close to uniform even
when $t$ is averaged over very short intervals inside the Hasse-Weil interval.


title:
New ATCA, ALMA and VISIR observations of the candidate LBV SK-67266
  (S61): the nebular mass from modelling 3D density distributions

abstract:
  We present new observations of the nebula around the Magellanic candidate
Luminous Blue Variable S61. These comprise high-resolution data acquired with
the Australia Telescope Compact Array (ATCA), the Atacama Large
Millimetre/Submillimetre Array (ALMA), and VISIR at the Very Large Telescope
(VLT). The nebula was detected only in the radio, up to 17 GHz. The 17 GHz ATCA
map, with 0.8 arcsec resolution, allowed a morphological comparison with the
H$\alpha$ Hubble Space Telescope image. The radio nebula resembles a spherical
shell, as in the optical. The spectral index map indicates that the radio
emission is due to free-free transitions in the ionised, optically thin gas,
but there are hints of inhomogeneities. We present our new public code RHOCUBE
to model 3D density distributions, and determine via Bayesian inference the
nebula's geometric parameters. We applied the code to model the electron
density distribution in the S61 nebula. We found that different distributions
fit the data, but all of them converge to the same ionised mass, ~0.1 $\rm
M\odot$, which is an order of magnitude smaller than previous estimates. We
show how the nebula models can be used to derive the mass-loss history with
high-temporal resolution. The nebula was probably formed through stellar winds,
rather than eruptions. From the ALMA and VISIR non-detections, plus the derived
extinction map, we deduce that the infrared emission observed by space
telescopes must arise from extended, diffuse dust within the ionised region.


title: A search for non-hidden broad-line region Seyfert 2 galaxies

abstract:
  According to the unified model of active galactic nuclei, Seyfert 2 galaxies
are physically the same as Seyfert 1 objects and they possess a broad-line
region (BLR), but it is hidden from the observer due to their orientation. In
the past few years, various authors reported that not all Seyfert 2 galaxies
harbor a BLR. We compiled a sample of 38 Seyfert 2 galaxies to find non-hidden
broad-line region (non-HBLR) objects. Using the theory of Nicastro et al. which
suggests the existence of a critical value of the Eddington ratio below which
BLR can't be formed, we found 26 non-HBLR Seyfert 2 candidates. We found also
that 5 of these 26 non-HBLR objects could be low-ionization nuclear
emission-line regions (LINERs).


title: Isoperimetric characterization of upper curvature bounds

abstract:
  We prove that a proper geodesic metric space has non-positive curvature in
the sense of Alexandrov if and only if it satisfies the Euclidean isoperimetric
inequality for curves. Our result extends to non-geodesic spaces and non-zero
curvature bounds.


title: Structures arising in the asymptotic dynamics of the Bianchi IX model

abstract:
  We present the analyses of the asymptotic evolution of the general Bianchi IX
spacetime using Hamiltonian formulation. The dynamics reveals the existence of
special structures, which we call wiggles, in the physical phase space. The
wiggles are different from the spikes known in the context of evolution of some
spacetime models towards gravitational singularities. Our results may be used
as starting point in the examination of wiggles at the quantum level.


title: Tian's invariant of the Grassmann manifold

abstract:
  We prove that Tian's invariant on the complex Grassmann manifold $G_{p,
q}(\mathbb{C})$ is equal to $1/(p+q)$.


title: Coclosed $G_2$-structures inducing nilsolitons

abstract:
  We show obstructions to the existence of a coclosed $G_2$-structure on a Lie
algebra $\mathfrak g$ of dimension seven with non-trivial center. In
particular, we prove that if there exist a Lie algebra epimorphism from
$\mathfrak g$ to a six-dimensional Lie algebra $\mathfrak h$, with kernel
contained in the center of $\mathfrak g$, then any coclosed $G_2$-structure on
$\mathfrak g$ induces a closed and stable three form on $\mathfrak h$ that
defines an almost complex structure on $\mathfrak h$. As a consequence, we
obtain a classification of the 2-step nilpotent Lie algebras which carry
coclosed $G_2$-structures. We also prove that each one of these Lie algebras
has a coclosed $G_2$-structure inducing a nilsoliton metric, but this is not
true for 3-step nilpotent Lie algebras with coclosed $G_2$-structures. The
existence of contact metric structures is also studied.


title: Superposition operators, Hardy spaces, and Dirichlet type spaces

abstract:
  For $0<p<\infty $ and $\alpha >-1$ the space of Dirichlet type $\mathcal
D^p_\alpha $ consists of those functions $f$ which are analytic in the unit
disc $\mathbb D$ and satisfy $\int_{\mathbb D}(1-| z| )^\alpha| f^\prime (z)|
^p\,dA(z)<\infty $. The space $\Dp$ is the closest one to the Hardy space $H^p$
among all the $\mathcal D^p_\alpha $. Our main object in this paper is studying
similarities and differences between the spaces $H^p$ and $\Dp$ ($0<p<\infty $)
regarding superposition operators. Namely, for $0<p<\infty $ and $0<s<\infty $,
we characterize the entire functions $\varphi $ such that the superposition
operator $S_\varphi $ with symbol $\varphi $ maps the conformally invariant
space $Q_s$ into the space $\Dp$, and, also, those which map $\Dp$ into $Q_s$
and we compare these results with the corresponding ones with $H^p$ in the
place of $\Dp$. We also study the more general question of characterizing the
superposition operators mapping $\mathcal D^p_\alpha $ into $Q_s$ and $Q_s$
into $\mathcal D^p_\alpha $, for any admissible triplet of numbers $(p, \alpha
, s)$.


title:
Coarsening in a 1-D system of Orienting Arrowheads: Persistence with
  $A+B \rightarrow$ 0

abstract:
  We demonstrate the large scale effects of the interplay between shape and
hard core interactions in a system with left- and right-pointing arrowheads
~$\textless ~~ \textgreater$~ on a line, with reorientation dynamics. This
interplay leads to the formation of two types of domain wall, diffusive ($A$)
and static ($B$). The correlation length in the equilibrium state diverges
exponentially with increasing arrowhead density, with an ordered state of like
orientations arising in the limit. In time, the approach to the ordered state
is described by a coarsening process governed by the kinetics of domain wall
annihilation $A+B\rightarrow 0$, quite different from $A+A \rightarrow 0$
kinetics pertinent to the Glauber-Ising model. The survival probability of a
finite set of walls is shown to decay exponentially in time, in contrast to the
power law decay known for $A+A \rightarrow 0$. In the thermodynamic limit with
a finite density of walls, coarsening as a function of time $t$ is studied by
simulation. While the number of walls falls as $t^{-\frac{1}{2}}$, the fraction
of persistent arrowheads decays as $t^{-\theta}$ where $\theta$ is close to
$\frac{1}{4}$, quite different from the Ising value. The global persistence too
has $\theta=\frac{1}{4}$, as follows from a heuristic argument. In a
generalization where the $B$ walls diffuse slowly, $\theta$ varies
continuously, increasing with increasing diffusion constant.


title: Temporal Convolutional Networks for Action Segmentation and Detection

abstract:
  The ability to identify and temporally segment fine-grained human actions
throughout a video is crucial for robotics, surveillance, education, and
beyond. Typical approaches decouple this problem by first extracting local
spatiotemporal features from video frames and then feeding them into a temporal
classifier that captures high-level temporal patterns. We introduce a new class
of temporal models, which we call Temporal Convolutional Networks (TCNs), that
use a hierarchy of temporal convolutions to perform fine-grained action
segmentation or detection. Our Encoder-Decoder TCN uses pooling and upsampling
to efficiently capture long-range temporal patterns whereas our Dilated TCN
uses dilated convolutions. We show that TCNs are capable of capturing action
compositions, segment durations, and long-range dependencies, and are over a
magnitude faster to train than competing LSTM-based Recurrent Neural Networks.
We apply these models to three challenging fine-grained datasets and show large
improvements over the state of the art.


title:
Optimising the multiplex factor of the frequency domain multiplexed
  readout of the TES-based microcalorimeter imaging array for the X-IFU
  instrument on the Athena Xray observatory

abstract:
  Athena is a space-based X-ray observatory intended for exploration of the hot
and energetic universe. One of the science instruments on Athena will be the
X-ray Integrated Field Unit (X-IFU), which is a cryogenic X-ray spectrometer,
based on a large cryogenic imaging array of Transition Edge Sensors (TES) based
microcalorimeters operating at a temperature of 100mK. The imaging array
consists of 3800 pixels providing 2.5 eV spectral resolution, and covers a
field of view with a diameter of of 5 arc minutes. Multiplexed readout of the
cryogenic microcalorimeter array is essential to comply with the cooling power
and complexity constraints on a space craft. Frequency domain multiplexing has
been under development for the readout of TES-based detectors for this purpose,
not only for the X-IFU detector arrays but also for TES-based bolometer arrays
for the Safari instrument of the Japanese SPICA observatory. This paper
discusses the design considerations which are applicable to optimise the
multiplex factor within the boundary conditions as set by the space craft. More
specifically, the interplay between the science requirements such as pixel
dynamic range, pixel speed, and cross talk, and the space craft requirements
such as the power dissipation budget, available bandwidth, and electromagnetic
compatibility will be discussed.


title:
Hilbert Transform, Analytic Signal, and Modulation Analysis for Graph
  Signal Processing

abstract:
  We propose Hilbert transform (HT) and analytic signal (AS) construction for
signals over graphs. This is motivated by the popularity of HT, AS, and
modulation analysis in conventional signal processing, and the observation that
complementary insight is often obtained by viewing conventional signals in the
graph setting. Our definitions of HT and AS use a conjugate-symmetry-like
property exhibited by the graph Fourier transform (GFT). We show that a real
graph signal (GS) can be represented using smaller number of GFT coefficients
than the signal length. We show that the graph HT (GHT) and graph AS (GAS)
operations are linear and shift-invariant over graphs. Using the GAS, we define
the amplitude, phase, and frequency modulations for a graph signal (GS).
Further, we use convex optimization to develop an alternative definition of
envelope for a GS. We illustrate the proposed concepts by showing applications
to synthesized and real-world signals. For example, we show that the GHT is
suitable for anomaly detection/analysis over networks and that GAS reveals
complementary information in speech signals.


title: Light Stops and Fine-Tuning in MSSM

abstract:
  We discuss the fine-tuning issue within the MSSM framework. Following the
idea that the fine-tuning can measure effects of some missing mechanism, we
impose non-universal gaugino masses at the GUT scalem and explore the low scale
implications. We realize that the fine-tuning parametrized with Delta_EW can be
as low as zero. We consider the stop mass with a special importance and focus
on the mass scales as m_stop <=700 GeV, which are excluded by current
experiments when the stop decays into a neutralino along with a top quark or a
chargino along with a b quark. We find that the stop mass can be as low as
about 200 GeV with Delta_EW ~ 50. We find that the solutions in this region can
be exluded only up to 60% when stop decays into a neutralino-top quark, and 50%
when it decays into a chargino-b quark pair. Setting 65% CL to be potential
exclusion and 95% to be pure exclusion limit such solutions will be tested in
near future experiments, which are conducted with higher luminosity. In
addition to stop, the region with low fine-tuning and light stops predicts
masses for the other supersymmetric particles such as m_sbottom >~ 600 GeV,
m_stau >~ 1 TeV, m_chargino >~ 120 GeV. The details for the mass scales and
decay rates are also provided by tables of benchmark points.


title: DeMeshNet: Blind Face Inpainting for Deep MeshFace Verification

abstract:
  MeshFace photos have been widely used in many Chinese business organizations
to protect ID face photos from being misused. The occlusions incurred by random
meshes severely degenerate the performance of face verification systems, which
raises the MeshFace verification problem between MeshFace and daily photos.
Previous methods cast this problem as a typical low-level vision problem, i.e.
blind inpainting. They recover perceptually pleasing clear ID photos from
MeshFaces by enforcing pixel level similarity between the recovered ID images
and the ground-truth clear ID images and then perform face verification on
them. Essentially, face verification is conducted on a compact feature space
rather than the image pixel space. Therefore, this paper argues that pixel
level similarity and feature level similarity jointly offer the key to improve
the verification performance. Based on this insight, we offer a novel feature
oriented blind face inpainting framework. Specifically, we implement this by
establishing a novel DeMeshNet, which consists of three parts. The first part
addresses blind inpainting of the MeshFaces by implicitly exploiting extra
supervision from the occlusion position to enforce pixel level similarity. The
second part explicitly enforces a feature level similarity in the compact
feature space, which can explore informative supervision from the feature space
to produce better inpainting results for verification. The last part copes with
face alignment within the net via a customized spatial transformer module when
extracting deep facial features. All the three parts are implemented within an
end-to-end network that facilitates efficient optimization. Extensive
experiments on two MeshFace datasets demonstrate the effectiveness of the
proposed DeMeshNet as well as the insight of this paper.


title:
Algorithmic aspects of multigrid methods for optimization in shape
  spaces

abstract:
  We examine the interaction of multigrid methods and shape optimization in
appropriate shape spaces. Our aim is a scalable algorithm for application on
supercomputers, which can only be achieved by mesh-independent convergence. The
impact of discrete approximations of geometrical quantities, like the mean
curvature, on a multigrid shape optimization algorithm with quasi-Newton
updates is investigated. For the purpose of illustration, we consider a complex
model for the identification of cellular structures in biology with minimal
compliance in terms of elasticity and diffusion equations.


title:
Blow-up problem for semilinear heat equation with nonlinear nonlocal
  Neumann boundary condition

abstract:
  In this paper, we consider a semilinear parabolic equation with nonlinear
nonlocal Neumann boundary condition and nonnegative initial datum. We first
prove global existence results. We then give some criteria on this problem
which determine whether the solutions blow up in finite time for large or for
all nontrivial initial data. Finally, we show that under certain conditions
blow-up occurs only on the boundary.


title: Test of CP Violation in $b\bar{b}$ pairs from top quark decay

abstract:
  Top pair events provide a source of $b\bar{b}$ pairs, which can be used to
probe CP violation in heavy-flavour mixing and decay. In events where one of
the $W$ bosons decays leptonically to an electron or muon, the charge of the
$W$ boson can be used to determine unambiguously the charge of the accompanying
$b$-quark at the time of its production. In cases where the $b$-quark also
decays semileptonically to a muon, this sample allows to probe two charge
asymmetries constructed with the charge signs of the $W$ and the soft muon. The
first measurement of the charge asymmetries in $b\bar{b}$ from top pair decays
is hence presented using the data collected with the ATLAS detector during the
8 TeV run of the LHC.


title: Limit theorems for weighted and regular Multilevel estimators

abstract:
  We aim at analyzing in terms of a.s. convergence and weak rate the
performances of the Multilevel Monte Carlo estimator (MLMC) introduced in
[Gil08] and of its weighted version, the Multilevel Richardson Romberg
estimator (ML2R), introduced in [LP14]. These two estimators permit to compute
a very accurate approximation of $I_0 = \mathbb{E}[Y_0]$ by a Monte Carlo type
estimator when the (non-degenerate) random variable $Y_0 \in L^2(\mathbb{P})$
cannot be simulated (exactly) at a reasonable computational cost whereas a
family of simulatable approximations $(Y_h)_{h \in \mathcal{H}}$ is available.
We will carry out these investigations in an abstract framework before applying
our results, mainly a Strong Law of Large Numbers and a Central Limit Theorem,
to some typical fields of applications: discretization schemes of diffusions
and nested Monte Carlo.


title: Fuzzballs in general relativity: a missed opportunity

abstract:
  Recently some 4d asymptotically $AdS_2 \times S^2$ regular bubbling solutions
written in terms of an arbitrary profile function has appeared in literature.
We discuss the possibility of extending these solutions to asymptotically flat
spaces, therefore building a model for an horizonless and singularity-free
fuzzball with the same asymptotic charges of the associated black hole,
directly in general relativity. A negative conclusion is reached within an
axial-symmetric ansatz inside the IWP family.


title:
A differential equation for the flow rate during silo discharge: Beyond
  the Beverloo rule

abstract:
  We present a differential equation for the flow rate of granular materials
during the discharge of a silo. This is based in the energy balance of the
variable mass system in contrast with the traditional derivations based on
heuristic postulates such as the free fall arch. We show that this new equation
is consistent with the well known Beverloo rule, providing an independent
estimate for the universal Beverloo prefactor. We also find an analytic
expression for the pressure under discharging conditions.


title:
A priori Estimates for the Compressible Euler Equations for a Liquid
  with Free Surface Boundary and the Incompressible Limit

abstract:
  In this paper, we prove a new type of energy estimates for the compressible
Euler's equation with free boundary, with a boundary part and an interior part.
These can be thought of as a generalization of the energies in Christodoulou
and Lindblad [CL] to the compressible case and do not require the fluid to be
irrotational. In addition, we show that our estimates are in fact uniform in
the sound speed. As a consequence, we obtain convergence of solutions of
compressible Euler equations with a free boundary to solutions of the
incompressible equations, generalizing the result of Ebin [Eb] to when you have
a free boundary. In the incompressible case our energies reduces to those in
[CL] and our proof in particular gives a simplified proof of the estimates in
[CL] with improved error estimates. Since for an incompressible irrotational
liquid with free surface there are small data global existence results our
result leaves open the possibility of long time existence also for slightly
compressible liquids with a free surface.


title:
Design and performance of a low frequency cross-polarized log-periodic
  dipole antenna

abstract:
  We report the design and performance of a cross-polarized log-periodic dipole
(CLPD) antenna for observations of polarized radio emission from the solar
corona at low frequencies. The measured isolation between the two mutually
orthogonal log periodic dipole antennas was as low as $\approx$ -43 dBm in the
65-95 MHz range. We carried out observations of the solar corona at 80 MHz with
the above CLPD and successfully recorded circularly polarized emission.


title: Toward Economics as a New Complex System

abstract:
  The 2015 Nobel Prize in Economic Sciences was awarded to Eugene Fama, Lars
Peter Hansen and Robert Shiller for their contributions to the empirical
analysis of asset prices. Eugene Fama [1] is an advocate of the efficient
market hypothesis. The efficient market hypothesis assumes that asset price is
determined by using all available information and only reacts to new
information not incorporated into the fundamentals. Thus, the movement of stock
prices is unpredictable. Robert Shiller [2] has been studying the existence of
irrational bubbles, which are defined as the long term deviations of asset
price from the fundamentals. This drives us to the unsettled question of how
the market actually works.
  In this paper, I look back at the development of economics and consider the
direction in which we should move in order to truly understand the workings of
an economic society.


title: The Standard Model Coupled to Quantum Gravitodynamics

abstract:
  We show that the renormalizable SO(4) X U (1) X SU (2) X SU (3) Yang Mills
coupled to matter and the Higgs field fits all the experimentally observed
differential cross sections known in nature. This extended Standard Model
reproduces the experimental gravitational differential cross sections without
resorting to the graviton field and instead by exchanging SO(4) gauge fields.
By construction, each SO(4) generator in quantum gravitodynamics does not
commute with the Dirac gamma matrices. This produces additional interactions
absent to non-Abelian gauge fields in the Standard Model. The contributions
from these new terms yield differential cross sections consistent with the
Newtonian and post Newtonian interactions derived from General Relativity.
Dimensional analysis of the Lagrangian shows that all its terms have total
dimensionality four or less and therefore that all physical quantities in the
theory renormalize by finite amounts. These properties make QGD the only
renormalizable 4-dimensional theory describing gravitational interactions.


title: Nonlinear Rheology in a Model Biological Tissue

abstract:
  Mechanical signaling plays a key role in biological processes like embryo
development and cancer growth. One prominent way to probe mechanical properties
of tissues is to study their response to externally applied forces. Using a
particle-based model featuring random apoptosis and environment-dependent
division rates, we evidence a crossover from linear flow to a shear-thinning
regime with increasing shear rate. To rationalize this non-linear flow we
derive a theoretical mean-field scenario that accounts for the interplay of
mechanical and active noise in local stresses. These noises are respectively
generated by the elastic response of the cell matrix to cell rearrangements and
by the internal activity.

categories: cond-mat.soft cond-mat.other cond-mat.stat-mech physics.bio-ph


title: Operational Experience with the ALICE Pixel detector

abstract:
  The Silicon Pixel Detector (SPD) constitutes the two innermost layers of the
Inner Tracking System of the ALICE experiment and it is the closest detector to
the interaction point. As a vertex detector, it has the unique feature of
generating a trigger signal that contributes to the L0 trigger of the ALICE
experiment. The SPD started collecting data since the very first pp collisions
at LHC in 2009 and since then it has taken part in all pp, Pb-Pb and p-Pb data
taking campaigns. This contribution will present the main features of the SPD,
the detector performance and the operational experience, including calibration
and optimization activities from Run 1 to Run 2.


title: Rectifiability of planes and Alberti representations

abstract:
  We study metric measure spaces that have quantitative topological control, as
well as a weak form of differentiable structure. In particular, let $X$ be a
pointwise doubling metric measure space. Let $U$ be a Borel subset on which the
blowups of $X$ are topological planes. We show that $U$ can admit at most $2$
independent Alberti representations. Furthermore, if $U$ admits $2$ Alberti
representations, then the restriction of the measure to $U$ is $2$-rectifiable.
This is a partial answer to the case $n=2$ of a question of the second author
and Schioppa.


title:
Connection formulas for the Ablowitz-Segur solutions of the
  inhomogeneous Painlev\'e II equation

abstract:
  We consider the second Painlev\'e equation $$ u"(x)=2u^3(x)+xu(x)-\alpha, $$
where $\alpha $ is a nonzero constant. Using the Deift-Zhou nonlinear steepest
descent method for Riemann-Hilbert problems, we rigorously prove the
asymptotics as $x \to \pm \infty$ for both the real and purely imaginary
Ablowitz-Segur solutions, as well as the corresponding connection formulas. We
also show that the real Ablowitz-Segur solutions have no real poles when
$\alpha \in (-1/2, 1/2)$.


title: Theory overview on amplitude analyses with charm decays

abstract:
  This contribution about amplitude analyses in multibody hadronic charm decays
deals with some attempts to introduce theoretical constraints. Different
effective hadronic formalism approaches are mentioned. A recent work, based on
a basic weak interaction process and a Chiral unitary model to account for the
final state interaction, is described in details for the $f_0(980)$ production
in $D_s^+ \to \pi^+ \pi^+ \pi^-$ and $D_s^+ \to \pi^+ K^+ K^- $ decays. Within
the framework of the diagrammatic approach and flavor symmetry, a global
analysis of two-body $D$ decays into a vector meson and a pseudoscalar meson is
presented. A quasi-two-body QCD factorization model for $D$ decays into three
mesons and its recent application to $D^0 \to K_S^0 \pi^+ \pi^-$ is outlined.
For processes with final-state pions and kaons and as an alternative to the sum
of Breit-Wigner amplitudes, often used in experimental Dalitz-plot analyses,
amplitude parametrizations, in term of unitary $\pi \pi$, $\pi K$ and $K \bar
K$ form factors, are proposed. These parametrizations are derived from
quasi-two-body factorization models.


title: Ionic liquid gating of ultra-thinYBa$_2$Cu$_3$O$_{7-x}$ films

abstract:
  In this paper, we present a detailed investigation of the self-field
transport properties of an ionic liquid gated ultra-thin YBa$_2$Cu$_3$O$_{7-x}$
film. From the high temperature dynamic of the resistivity ($> 220 \textrm{
K}$) different scenarios pertaining to the interaction between the liquid and
the thin film are proposed. From the low temperature evolution of
$J_{\textrm{c}}$ and $T_{\textrm{c}}$ a comparison between the behavior of our
system and the standard properties of YBCO is drawn.


title:
Analysis of Price and Income Elasticities of Energy Demand in Ecuador: A
  Dynamic OLS Approach

abstract:
  Energy consumption in Ecuador has increased significantly during the last
decades, affecting negatively the financial position of the country since large
energy consumption subsidies are provided in its internal market and Ecuador is
mostly a crude oil exporter and oil derivatives importer country. This research
seeks to state the long run price and income elasticities of energy demand in
Ecuador, by analyzing information spanning the period from 1970 to 2015. A
cointegration analysis and an estimation by using a Dynamic Ordinary Least
Squares approach considering structural breaks is carried out. Results obtained
are robust and suggest that in the long run energy demand in Ecuador is highly
income elastic, has no relationship with its price and has an almost unitary
but inverse relationship with the industrial production level. Conclusions and
economic policy suggestions are also provided.


title: SpatialPack: Computing the Association Between Two Spatial Processes

abstract:
  An R package SpatialPack that implements routines to compute point estimators
and perform hypothesis testing of the spatial association between two
stochastic sequences is introduced. These methods address the spatial
association between two processes that have been observed over the same spatial
locations. We briefly review the methodologies for which the routines are
developed. The core routines have been implemented in C and linked to R to
ensure a reasonable computational speed. Three examples are presented to
illustrate the use of the package with both simulated and real data. The
particular case of computing the association between two time series is also
considered. Besides elementary plots and outputs we also provide a plot to
visualize the spatial correlation in all directions using a new graphical tool
called codispersion map. The potential extensions of SpatialPack are also
discussed.


title:
The original nucleation and migration of the basal/prismatic interfaces
  in Mg single crystals

abstract:
  The formation of basal/prismatic (BP) interfaces accompanying with the
nucleation and growth of a reoriented crystal in Mg single-crystals under
c-axis tension is investigated by molecular dynamics simulations. The BP
interfaces nucleate by shuffling mechanism via local rearrangements of atoms.
Both two-layer disconnections and one-layer disconnections contribute to the
migration of BP interfaces. In a three-dimensional view, the BP interfaces
relatively tend to migrate towards the [1-210] direction rather than the
[-1010]/[0001] direction since the misfit disconnection or misfit dislocation
caused by the accumulation of mismatch along the [-1010] /[0001] direction
impedes the disconnection movement. The BP interfaces can transform to the
{10-12} twin boundary (TB) and vice versa. While the process from BP interface
to TB is described as the linear pile-up of interface disconnections, the versa
transformation is proposed as the upright pile-up process. Both BP
transformation and {10-12} twinning can efficiently accommodate the strain
along the c-axis, and the conjugate BP interfaces and {10-12} TBs account for
the large deviations of twin interfaces from the {10-12} twin plane.


title:
Open Wilson chains for quantum impurity models: Keeping track of all
  bath modes

abstract:
  When constructing a Wilson chain to represent a quantum impurity model, the
effects of truncated bath modes are neglected. We show that their influence can
be kept track of systematically by constructing an "open Wilson chain" in which
each site is coupled to a separate effective bath of its own. As a first
application, we use the method to cure the so-called mass-flow problem that can
arise when using standard Wilson chains to treat impurity models with
asymmetric bath spectral functions at finite temperature. We demonstrate this
for the strongly sub-Ohmic spin-boson model at quantum criticality where we
directly observe the flow towards a Gaussian critical fixed point.


title: Shelah-Villaveces revisited

abstract:
  We study uniqueness of limit models in abstract elementary classes (AECs)
with no maximal models. We prove (assuming instances of diamonds) that
categoricity in a cardinal of the form $\mu^{+(n + 1)}$ implies the uniqueness
of limit models of cardinality $\mu^{+}, \mu^{++}, \ldots, \mu^{+n}$. This
sheds light on a paper of Shelah and Villaveces, who were the first to consider
uniqueness of limit models in this context. We also prove that (again assuming
instances of diamonds) in an AEC with no maximal models, tameness (a locality
property for types) together with categoricity in a proper class of cardinals
imply categoricity on a tail of cardinals. This is the first categoricity
transfer theorem in that setup and answers a question of Baldwin.


title: A Parallelized Vlasov-Fokker-Planck-Solver for Desktop PCs

abstract:
  The numerical solution of the Vlasov-Fokker-Planck equation is a well
established method to simulate the dynamics, including the self-interaction
with its own wake field, of an electron bunch in a storage ring. In this paper
we present Inovesa, a modularly extensible program that uses OpenCL to
massively parallelize the computation. It allows a standard desktop PC to work
with appropriate accuracy and yield reliable results within minutes. We provide
numerical stability-studies over a wide parameter range and compare our
numerical findings to known results. Simulation results for the case of
coherent synchrotron radiation will be compared to measurements that probe the
effects of the micro-bunching instability occurring in the short bunch
operation at ANKA. It will be shown that the impedance model based on the
shielding effect of two parallel plates can not only describe the instability
threshold, but also the presence of multiple regimes that show differences in
the emission of coherent synchrotron radiation.


title:
First experience with classical-statistical real-time simulations of
  anomalous transport with overlap fermions

abstract:
  We present first results of classical-statistical real-time simulations of
anomalous transport phenomena with overlap fermions. We find that even on small
lattices overlap fermions reproduce the real-time anomaly equation with much
better precision than Wilson-Dirac fermions on an order of magnitude larger
lattices. The difference becomes much more pronounced for quickly changing
electromagnetic fields, especially if one takes into account the back-reaction
of fermions on electromagnetism. As test cases, we consider chirality pumping
in parallel electric and magnetic fields and mixing between the plasmon and the
Chiral Magnetic Wave.


title:
Anamorphic Quasiperiodic Universes in Modified and Einstein Gravity with
  Loop Quantum Gravity Corrections

abstract:
  The goal of this work is to elaborate on new geometric methods of
constructing exact and parametric quasiperiodic solutions for anamorphic
cosmology models in modified gravity theories, MGTs, and general relativity,
GR. There exist previously studied generic off-diagonal and diagonalizable
cosmological metrics encoding gravitational and matter fields with quasicrystal
like structures, QC, and holonomy corrections from loop quantum gravity, LQG.
We apply the anholonomic frame deformation method, AFDM, in order to decouple
the (modified) gravitational and matter field equations in general form. This
allows us to find integral varieties of cosmological solutions determined by
generating functions, effective sources, integration functions and constants.
The coefficients of metrics and connections for such cosmological
configurations depend, in general, on all spacetime coordinates and can be
chosen to generate observable (quasi)-periodic/ aperiodic/ fractal / stochastic
/ (super) cluster / filament / polymer like (continuous, stochastic, fractal
and/or discrete structures) in MGTs and/or GR. In this work, we study new
classes of solutions for anamorphic cosmology with LQG holonomy corrections.
Such solutions are characterized by nonlinear symmetries of generating
functions for generic off--diagonal cosmological metrics and generalized
connections, with possible nonholonomic constraints to Levi-Civita
configurations and diagonalizable metrics depending only on a time like
coordinate. We argue that anamorphic quasiperiodic cosmological models
integrate the concept of quantum discrete spacetime, with certain gravitational
QC-like vacuum and nonvacuum structures. And, that of a contracting universe
that homogenizes, isotropizes and flattens without introducing initial
conditions or multiverse problems.


title:
Maximal function, Littlewood--Paley theory, Riesz transform and atomic
  decomposition in the multi-parameter flag setting

abstract:
  In this paper, we develop via real variable methods various characterisations
of the Hardy spaces in the multi-parameter flag setting. These
characterisations include those via, the non-tangential and radial maximal
function, the Littlewood--Paley square function and area integral, Riesz
transforms and the atomic decomposition in the multi-parameter flag setting.
The novel ingredients in this paper include (1) establishing appropriate
discrete Calder\'on reproducing formulae in the flag setting and a version of
the Plancherel--P\'olya inequalities for flag quadratic forms; (2) introducing
the maximal function and area function via flag Poisson kernels and flag
version of harmonic functions; (3) developing an atomic decomposition via the
finite speed propagation and area function in terms of flag heat semigroups. As
a consequence of these real variable methods, we obtain the full
characterisations of the multi-parameter Hardy space with the flag structure.


title:
The Masterclass of particle physics and scientific careers from the
  point of view of male and female students

abstract:
  With this study we tried to investigate if male and female students have a
different perception of scientific careers. At the end, we would like to be
able to provide hints on how to intervene to correct the path that seems to
naturally bring male students towards STEM disciplines (science, technology,
engineering, and math) and reject female students from them.


title:
Finite sets of operations sufficient to construct any fullerene from
  $C_{20}$

abstract:
  We study the well-known problem of combinatorial classification of
fullerenes. By a (mathematical) fullerene we mean a convex simple three
dimensional polytope with all facets pentagons and hexagons. We analyse
approaches of construction of arbitrary fullerene from the dodecahedron (a
fullerene $C_{20}$). A growth operation is a combinatorial operation that
substitutes the patch with more facets and the same boundary for the patch on
the surface of a simple polytope to produce a new simple polytope. It is known
that an infinite set of different growth operations transforming fullerenes
into fullerenes is needed to construct any fullerene from the dodecahedron. We
prove that if we allow a polytope to contain one exceptional facet, which is a
quadrangle or a heptagon, then a finite set of growth operation is sufficient.
We analyze pairs of objects: a finite set of operations, and a family of
acceptable polytopes containing fullerenes such that any polytope of the family
can be obtained from the dodecahedron by a sequence of operations from the
corresponding set. We describe explicitly three such pairs. First two pairs
contain seven operations, and the last -- eleven operations. Each of these
operations corresponds to a finite set of growth operations and is a
composition of edge- and two edges-truncations.


title:
Observation of Rydberg-atom macrodimers: micrometer-sized diatomic
  molecules

abstract:
  Long-range metastable molecules consisting of two cesium atoms in high
Rydberg states have been observed in an ultracold gas. A sequential
three-photon two-color photoassociation scheme was employed to form these
molecules in states which correlate to $np(n+1)s$ dissociation asymptotes.
Spectral signatures of bound molecular states are clearly resolved at the
positions of avoided crossings between long-range van der Waals potential
curves. The experimental results are in agreement with simulations based on a
detailed model of the long-range multipole-multipole interactions of
Rydberg-atom pair states. We show that a full model is required to accurately
predict the occurrence of bound Rydberg macrodimers. The macrodimers are
distinguished from repulsive molecular states by their behavior with respect to
spontaneous ionization and possible decay channels are discussed.


title: Weak solutions for the $\alpha$-Euler equations and convergence to Euler

abstract:
  We consider the limit $\alpha\to0$ for the $\alpha$-Euler equations in a
two-dimensional bounded domain with Dirichlet boundary conditions. Assuming
that the vorticity is bounded in $L^p$, we prove the existence of a global
solution and we show the convergence towards a solution of the incompressible
Euler equation with $L^p$ vorticity. The domain can be multiply-connected. We
also discuss the case of the second grade fluid when both $\alpha$ and $\nu$ go
to 0.


title:
Generalisation and Sharing in Triplet Convnets for Sketch based Visual
  Search

abstract:
  We propose and evaluate several triplet CNN architectures for measuring the
similarity between sketches and photographs, within the context of the sketch
based image retrieval (SBIR) task. In contrast to recent fine-grained SBIR
work, we study the ability of our networks to generalise across diverse object
categories from limited training data, and explore in detail strategies for
weight sharing, pre-processing, data augmentation and dimensionality reduction.
We exceed the performance of pre-existing techniques on both the Flickr15k
category level SBIR benchmark by $18\%$, and the TU-Berlin SBIR benchmark by
$\sim10 \mathcal{T}_b$, when trained on the 250 category TU-Berlin
classification dataset augmented with 25k corresponding photographs harvested
from the Internet.


title:
A composite likelihood ratio approach to the analysis of correlated
  binary data in genetic association studies

abstract:
  The likelihood function represents statistical evidence in the context of
data and a probability model. Considerable theory has demonstrated that
evidence strength for different parameter values can be interpreted from the
ratio of likelihoods at different points on the likelihood curve. The
likelihood function can, however, be unknown or difficult to compute; e.g. for
genetic association studies with a binary outcome in large multi-generational
families. Composite likelihood is a convenient alternative to using the real
likelihood and here we show composite likelihoods have valid evidential
interpretation. We show that composite likelihoods, with a robust adjustment,
have two large sample performance properties that enable reliable evaluation of
relative evidence for different values on the likelihood curve: (1) The
composite likelihood function will support the true value over the false value
by an arbitrarily large factor; and (2) the probability of favouring a false
value over a true value with high probability is small and bounded. Using an
extensive simulation study, and in a genetic association analysis of reading
disability in large complex pedigrees, we show that the composite approach
yields valid statistical inference. Results are compared to analyses using
generalized estimating equations and show similar inference is obtained,
although the composite approach results in a full likelihood solution that
provides additional complementary information.


title: Octonacci Photonic Crystals with Negative Refraction Index Materials

abstract:
  We investigate the optical transmission spectra for $s$-polarized (TE) and
$p$-polarized (TM) waves in one-dimensional photonic quasicrystals on a
quasiperiodic multilayer structure made up by alternate layers of SiO$_{2}$ and
\textit{metamaterials}, organized by following the Octonacci sequence.
Maxwell's equations and the transfer-matrix technique are used to derive the
transmission spectra for the propagation of normaly and obliquely incident
optical fields. We assume Drude-Lorentz-type dispersive response for the
dielectric permittivity and magnetic permeability of the metamaterials. For
normally incident waves, we observe that the spectra does not have self-similar
behavior or mirror symmetry and it also features the absence of optical band
gap. Also for normally incident waves, we show regions of full transmittance
when the incident angle $\theta_{C} = 0^{\circ}$ in a particular frequency
range.


title:
Physical reality of electromagnetic potentials and the classical limit
  of the Aharonov-Bohm effect

abstract:
  Recent literature on the Aharonov-Bohm effect has raised fundamental
questions on the classical correspondence of this effect and the physical
reality of the electromagnetic potentials in quantum mechanics. Reappraisal on
Feynman's approach to the classical limit of AB effect is presented. The
critique throws light on the significance of quantum interference and quantum
phase shifts in any such classical correspondence. Detailed analysis shows that
Feynman arguments are untenable on physical grounds and the claim made in the
original AB paper that this effect had no classical analog seems valid. The
importance of nonintegrable phase factor distinct from the AB phase factor,
here termed as Fock-London-Weyl phase factor for the historical reasons, is
underlined in connection with the classical aspects/limits. A topological
approach incorporating the physical significance of the interaction field
momentum is proposed. A new idea emerges from this approach that attributes the
origin of the AB effect to the exchange of modular angular momentum.


title:
Hyperspherical Slater determinant approach to few-body fractional
  quantum Hall states

abstract:
  In a recent study[Phys. Rev. B 92 (2015) 125427], a hyperspherical approach
has been developed to study of few-body fractional quantum Hall states. This
method has been successfully applied to the exploration of few boson and
fermion problems in the quantum Hall region, as well as the study of
inter-Landau level collective excitations. However, the hyperspherical method
as it is normally implemented requires a subsidiary (anti-)symmetrization
process, which limits its computational effectiveness. The present work
overcomes these difficulties and extends the power of this method by
implementing a represen- tation of the hyperspherical many-body basis space in
terms of Slater determinants of single particle eigenfunctions. A clear
connection between the hyperspherical representation and the conventional
single particle picture is presented, along with a compact operator
representation of the theoretical framework.


title:
Thermal and hydrodynamic studies for micro-channel cooling for large
  area silicon sensors in high energy physics experiments

abstract:
  Micro-channel cooling initially aiming at small-sized high-power integrated
circuits is being transferred to the field of high energy physics. Today`s
prospects of micro-fabricating silicon opens a door to a more direct cooling of
detector modules. The challenge in high energy physics is to save material in
the detector construction and to cool large areas. In this paper, we are
investigating micro-channel cooling as a candidate for a future cooling system
for silicon detectors in a generic research and development approach. The work
presented in this paper includes the production and the hydrodynamic and
thermal testing of a micro-channel equipped prototype optimized to achieve a
homogeneous flow distribution. Furthermore, the device was simulated using
finite element methods.


title: A traffic model with an absorbing-state phase transition

abstract:
  We consider a modified Nagel-Schreckenberg (NS) model in which drivers do not
decelerate if their speed is smaller than the headway (number of empty sites to
the car ahead). (In the original NS model, such a reduction in speed occurs
with probability $p$, independent of the headway, as long as the current speed
is greater than zero.) In the modified model the free-flow state (with all
vehicles traveling at the maximum speed, $v_{max}$) is {\it absorbing} for
densities $\rho$ smaller than a critical value $\rho_c = 1/(v_{max} + 2)$. The
phase diagram in the $\rho - p$ plane is reentrant: for densities in the range
$\rho_{c,<} < \rho < \rho_c$, both small and large values of $p$ favor free
flow, while for intermediate values, a nonzero fraction of vehicles have speeds
$< v_{max}$. In addition to representing a more realistic description of
driving behavior, this change leads to a better understanding of the phase
transition in the original model. Our results suggest an unexpected connection
between traffic models and stochastic sandpiles.


title: Solar ALMA predictions: tutorial

abstract:
  I have proposed that long Halpha fibrils are caused by heating events of
which the tracks are afterwards outlined by contrails of cooling gas with
extraordinary Halpha opacity and yet larger opacity at the ALMA wavelengths.
Here I detail the radiative transfer background.


title: A lower bound for the gonality conjecture

abstract:
  For every integer $k \geq 3$ we construct a $k$-gonal curve $C$ along with a
very ample divisor of degree $2g + k - 1$ (where $g$ is the genus of $C$) to
which the vanishing statement from the Green-Lazarsfeld gonality conjecture
does not apply.


title: Numerical Modeling of MEMS Resonators

abstract:
  Microelectromechanical systems (MEMS) resonators serve as frequency selective
components in applications ranging from biology to communications. In this
paper, the dynamic behavior of an RF MEMS disk resonator is formulated using an
analytical method.


title: On graphs with three or four distinct normalized Laplacian eigenvalues

abstract:
  In this paper, we characterize all connected graphs with exactly three
distinct normalized Laplacian eigenvalues of which one is equal to $1$,
determine all connected bipartite graphs with at least one vertex of degree $1$
having exactly four distinct normalized Laplacian eigenvalues, and find all
unicyclic graphs with three or four distinct normalized Laplacian eigenvalues.


title:
Euler-like vector fields, deformation spaces and manifolds with filtered
  structure

abstract:
  The first purpose of this note is to comment on a recent article of Bursztyn,
Lima and Meinrenken, in which it is proved that if M is a smooth submanifold of
a manifold V, then there is a bijection between germs of tubular neighborhoods
of M and germs of "Euler-like" vector fields on V. We shall explain how to
approach this bijection through the deformation to the normal cone that is
associated to the embedding of M into V. The second purpose is to study
generalizations to smooth manifolds equipped with Lie filtrations. Following in
the footsteps of several others, we shall define a deformation to the normal
cone that is appropriate to this context, and relate it to Euler-like vector
fields and tubular neighborhood embeddings.


title:
"What is The SI?" A Proposal for an Educational Adjunct to the SI
  Redefinition

abstract:
  We discuss how the likely 2018 redefinition of the SI system of units might
affect the ability of students to understand the link between the units and the
new system. The likely redefinition will no longer define a set of base units,
but rather a set of constants of nature, such as the speed of light c and a
particular hyperfine splitting in Cs $\Delta\nu(^{133}$Cs)$_{hfs}$. We point
out that this list of constants need not be the only way to introduce students
to the subject, either in class or in textbooks. We suggest an alternative way
to introduce high school and undergraduate students to the redefined SI, by
suggesting a list of experiments for some units; this list would be completely
compatible with the redefined SI, and would have all of the same scientific and
technological advantages. We demonstrate by questionnaire results that this
alternative is more appealing to students. We hope to spur a discussion amongst
teachers regarding this important topic for high school and undergraduate
physics courses.


title: On a special class of general permutahedra

abstract:
  Minkowski sums of simplices in ${\mathbb{R}}^n$ form an interesting class of
polytopes that seem to emerge in various situations. In this paper we discuss
the Minkowski sum of the simplices $\Delta_{k-1}$ in ${\mathbb{R}}^n$ where $k$
and $n$ are fixed, their flags and some of their face lattice structure. In
particular, we derive a closed formula for their {\em exponential generating
flag function}. These polytopes are simple, include both the simplex
$\Delta_{n-1}$ and the permutahedron $\Pi_{n-1}$, and form a Minkowski basis
for more general permutahedra.


title: General Covariance from the Quantum Renormalization Group

abstract:
  The Quantum renormalization group (QRG) is a realisation of holography
through a coarse graining prescription that maps the beta functions of a
quantum field theory thought to live on the `boundary' of some space to
holographic actions in the `bulk' of this space. A consistency condition will
be proposed that translates into general covariance of the gravitational theory
in the $D + 1$ dimensional bulk. This emerges from the application of the QRG
on a planar matrix field theory living on the $D$ dimensional boundary. This
will be a particular form of the Wess--Zumino consistency condition that the
generating functional of the boundary theory needs to satisfy. In the bulk,
this condition forces the Poisson bracket algebra of the scalar and vector
constraints of the dual gravitational theory to close in a very specific
manner, namely, the manner in which the corresponding constraints of general
relativity do. A number of features of the gravitational theory will be fixed
as a consequence of this form of the Poisson bracket algebra. In particular, it
will require the metric beta function to be of gradient form.


title:
Quark confinement due to creation of micro AdS black holes in quarkonium
  model

abstract:
  We use the solution of the Dirac equation for quarkonium atom in the 4D Anti
de sitter (AdS$_{4}$) space to investigate the effect of the large negative
cosmological constant on the phenomenon of quark confinement. We do the
required calculations in the AdS$_{4}$ space to indicate that large
cosmological constant can describe the quark confinement. In fact using the
coulomb potential in Dirac equation while we employ the AdS metric will
additionally lead us to a linear potential in the quark-antiquark interaction
which can be considered to explain the quark confinement. This confining term
is arising essentially from the geometrical features of the space. On the other
hand the origin of the large cosmological constant can be justified by assuming
the appearance of micro black holes in the recent hadronic collision process
which is now current, for instance, at the LHC project.


title: A Learning Scheme for Microgrid Islanding and Reconnection

abstract:
  This paper introduces a potential learning scheme that can dynamically
predict the stability of the reconnection of sub-networks to a main grid. As
the future electrical power systems tend towards smarter and greener
technology, the deployment of self sufficient networks, or microgrids, becomes
more likely. Microgrids may operate on their own or synchronized with the main
grid, thus control methods need to take into account islanding and reconnecting
of said networks. The ability to optimally and safely reconnect a portion of
the grid is not well understood and, as of now, limited to raw synchronization
between interconnection points. A support vector machine (SVM) leveraging
real-time data from phasor measurement units (PMUs) is proposed to predict in
real time whether the reconnection of a sub-network to the main grid would lead
to stability or instability. A dynamics simulator fed with pre-acquired system
parameters is used to create training data for the SVM in various operating
states. The classifier was tested on a variety of cases and operating points to
ensure diversity. Accuracies of approximately 85% were observed throughout most
conditions when making dynamic predictions of a given network.


title: A Darcy-Brinkman Model of Fractures in Porous Media

abstract:
  For a fully-coupled Darcy-Stokes system describing the exchange of fluid and
stress balance across the interface between a saturated porous medium and an
open very narrow channel, the limiting problem is characterized as the width of
the channel converges to zero. It is proven that the limit problem is a
fully-coupled system of Darcy flow in the porous medium with Brinkman flow in
tangential coordinates of the lower dimensional interface.


title:
Guidefill: GPU Accelerated, Artist Guided Geometric Inpainting for 3D
  Conversion

abstract:
  The conversion of traditional film into stereo 3D has become an important
problem in the past decade. One of the main bottlenecks is a disocclusion step,
which in commercial 3D conversion is usually done by teams of artists armed
with a toolbox of inpainting algorithms. A current difficulty in this is that
most available algorithms are either too slow for interactive use, or provide
no intuitive means for users to tweak the output. In this paper we present a
new fast inpainting algorithm based on transporting along automatically
detected splines, which the user may edit. Our algorithm is implemented on the
GPU and fills the inpainting domain in successive shells that adapt their shape
on the fly. In order to allocate GPU resources as efficiently as possible, we
propose a parallel algorithm to track the inpainting interface as it evolves,
ensuring that no resources are wasted on pixels that are not currently being
worked on. Theoretical analysis of the time and processor complexiy of our
algorithm without and with tracking (as well as numerous numerical experiments)
demonstrate the merits of the latter. Our transport mechanism is similar to the
one used in coherence transport, but improves upon it by corrected a "kinking"
phenomena whereby extrapolated isophotes may bend at the boundary of the
inpainting domain. Theoretical results explaining this phenomena and its
resolution are presented. Although our method ignores texture, in many cases
this is not a problem due to the thin inpainting domains in 3D conversion.
Experimental results show that our method can achieve a visual quality that is
competitive with the state-of-the-art while maintaining interactive speeds and
providing the user with an intuitive interface to tweak the results.


title:
Toric Mutations in the dP$_2$ Quiver and Subgraphs of the dP$_2$ Brane
  Tiling

abstract:
  Brane tilings are infinite, bipartite, periodic, planar graphs that are dual
to quivers. In this paper, we examine the del Pezzo 2 (dP$_2$) quiver and its
brane tiling, which arise from the physics literature, in terms of toric
mutations on its corresponding cluster. Specifically, we give explicit formulas
for all cluster variables generated by toric mutation sequences. Moreover, for
each such variable, we associate a subgraph of the dP$_2$ brane tiling to it
such that its weight matches the variable.


title: A Semi-supervised Framework for Image Captioning

abstract:
  State-of-the-art approaches for image captioning require supervised training
data consisting of captions with paired image data. These methods are typically
unable to use unsupervised data such as textual data with no corresponding
images, which is a much more abundant commodity. We here propose a novel way of
using such textual data by artificially generating missing visual information.
We evaluate this learning approach on a newly designed model that detects
visual concepts present in an image and feed them to a reviewer-decoder
architecture with an attention mechanism. Unlike previous approaches that
encode visual concepts using word embeddings, we instead suggest using regional
image features which capture more intrinsic information. The main benefit of
this architecture is that it synthesizes meaningful thought vectors that
capture salient image properties and then applies a soft attentive decoder to
decode the thought vectors and generate image captions. We evaluate our model
on both Microsoft COCO and Flickr30K datasets and demonstrate that this model
combined with our semi-supervised learning method can largely improve
performance and help the model to generate more accurate and diverse captions.


title:
Approximate Capacity Region of the Two-User Gaussian Interference
  Channel with Noisy Channel-Output Feedback

abstract:
  In this paper, the capacity region of the linear deterministic interference
channel with noisy channel-output feedback (LD-IC-NF) is fully characterized.
The proof of achievability is based on random coding arguments and rate
splitting; block-Markov superposition coding; and backward decoding. The proof
of converse reuses some of the existing outer bounds and includes new ones
obtained using genie-aided models. Following the insight gained from the
analysis of the LD-IC-NF, an achievability region and a converse region for the
two-user Gaussian interference channel with noisy channel-output feedback
(GIC-NF) are presented. Finally, the achievability region and the converse
region are proven to approximate the capacity region of the G-IC-NF to within
4.4 bits.


title: A Brief Note on Anomalous Effects in 2D Crystals

abstract:
  In this brief note we point out that in the case of two dimensional crystals
like graaphene, there is an interesting anomalous behaviour of Fermions. This
could potentially be useful.


title:
Dynamics of the universe with disformal coupling between the dark
  sectors

abstract:
  We use the dynamical analysis to study the evolution of the universe at late
time for the model in which the interaction between dark energy and dark matter
is inspired by disformal transformation. We extend the analysis in the existing
literature by supposing that the disformal coefficient depends both on the
scalar field and its kinetic terms. We find that the dependence of the
disformal coefficient on the kinetic term of scalar field leads to two classes
of the scaling fixed points that can describe the acceleration of the universe
at late time. The first class exists only for the case where the disformal
coefficient depends on the kinetic terms. The fixed points in this class are
saddle points unless the slope of the conformal coefficient is sufficiently
large. The second class can be viewed as the generalization of the fixed points
studied in the literature. According to the stability analysis of these fixed
points, we find that the stable fixed point can take two different physically
relevant values for the same value of the parameters of the model. These
different values of the fixed points can be reached for different initial
conditions for the equation of state parameter of dark energy. We also discuss
the situations in which this feature disappears.


title: Transition probability spaces in loop quantum gravity

abstract:
  We study the (generalized) transition probability spaces, in the sense of
Mielnik and Cantoni, for spacetime quantum states in loop quantum gravity.
First, we show that loop quantum gravity admits the structures of transition
probability spaces. This is exemplified by first checking such structures in
covariant quantum mechanics, and then identify the transition probability
spaces in spin foam models via a simplified discrete version of general
boundary formulation. The transition probability space thus defined gives a
simple way to reconstruct the discrete analog of the Hilbert space of the
canonical theory and the relevant quantum logical structures. Second, we show
that the transition probability space and in particular the spin foam model are
2-categories. Then we discuss how to realize in spin foam models two proposals
by Crane about the mathematical structures of quantum gravity, namely the
quantum topos and causal sites. We conclude that transition probability spaces
provide us with an alternative framework to understand various foundational
questions of loop quantum gravity.


title: An exponential correction to Starobinsky's inflationary model

abstract:
  We analyse $f(R)$ theories of gravity from a dynamical system perspective,
showing how the $R^2$ correction in Starobinsky's model plays a crucial role
from the viewpoint of the inflationary paradigm. Then, we propose a
modification of Starobinsky's model by adding an exponential term in the $f(R)$
Lagrangian. We show how this modification could allow to test the robustness of
the model by means of the predictions on the scalar spectral index $n_s$.