title:
State refinements and coarse graining in a full theory embedding of loop
  quantum cosmology

abstract:
  Bridging between descriptions involving few large and many small quantum
numbers is the main open problem in loop quantum gravity. In other words, one
would like to be able to represent the same physical system in terms of a few
"coarse"' quantum numbers, while the effective dynamics at the coarse level
should agree with the one induced by a description involving many small quantum
numbers. Efforts to understand this relationship face the problem of the
enormous computational complexity involved in evolving a generic state
containing many quanta. In a cosmological context however, certain symmetry
assumptions on the quantum states allow to simplify the problem. In this paper,
we will show how quantum states describing a spatially flat homogeneous and
isotropic universe can be refined and coarse grained. Invariance of the
dynamics of the coarse observables is shown to require a certain scaling
property (familiar from loop quantum cosmology) of the quantum states if no
running of parameters is taken into account. The involved states are solutions
to the Hamiltonian constraint when terms coming from spatial derivatives are
neglected, i.e. one works in the approximation of non-interacting FRW patches.
The technical means to arrive at this result are a version of loop quantum
gravity based on variables inspired by loop quantum cosmology, as well as an
exact solution to the quantum dynamics of loop quantum cosmology which extends
to the full theory in the chosen approximation.


title:
Properties of the outer regions of spiral disks: abundances, colors and
  ages

abstract:
  We summarize the results obtained from our suite of chemical evolution models
for spiral disks, computed for different total masses and star formation
efficiencies. Once the gas, stars and star formation radial distributions are
reproduced, we analyze the Oxygen abundances radial profiles for gas and stars,
in addition to stellar averaged ages and global metallicity. We examine
scenarios for the potential origin of the apparent flattening of abundance
gradients in the outskirts of disk galaxies, in particular the role of
molecular gas formation prescriptions.


title:
Buchdahl-Vaidya-Tikekar model for stellar interior in pure Lovelock
  gravity - II

abstract:
  For a given Lovelock order $N$, it turns out that static fluid solutions of
the pure Lovelock equation for a star interior have the universal behavior in
all $n\geq 2N+2$ dimensions relative to an appropriately defined variable and
the Vaidya-Tikekar parameter $K$, indicating deviation from sphericity of
$3$-space geometry. We employ the Buchdahl metric ansatz which encompasses
almost all the known physically acceptable models including in particular the
Vaidya-Tikekar and Finch-Skea. Further for a given star radius, the constant
density star, always described by the Schwarzschild interior solution, defines
the most compact state of distribution while the other end is marked by the
Finch-Skea model, and all the other physically tenable models lie in between
these two limiting distributions.


title: One-sided $(b, c)$-inverses in rings

abstract:
  In this paper we introduce a new generalized inverse in a ring -- one-sided
$(b, c)$-inverse, derived as an extension of $(b, c)$-inverse. This inverse
also generalizes one-sided inverse along an element, which was recently
introduced by H. H. Zhu et al. [H. H. Zhu, J. L. Chen, P. Patr\'{i}cio, Further
results on the inverse along an element in semigroups and rings, Linear
Multilinear Algebra, 64 (3) (2016) 393-403]. Also, here we present one-sided
annihilator $(b, c)$-inverse, which is an extension of the annihilator $(b,
c)$-inverse. Necessary and sufficient conditions for the existence of these new
generalized inverses are obtained. Furthermore, we investigate conditions for
the existence of one-sided $(b, c)$-inverse of a product of three elements and
we consider some properties of one-sided $(b, c)$-inverses.


title: Green Cloud Radio Access Networks

abstract:
  Cloud radio access networks (C-RAN) are a promising technology to enable the
ambitious vision of the fifth generation (5G) communication networks. In spite
of the potential benefits of C-RAN, the operational costs are still a
challenging issue, mainly due to the centralized processing scheme and the
large number of operating remote radio head (RRH) connecting to the cloud. In
this work we consider a setup in which a CRAN is powered partially with a set
of renewable energy sources (RESs), our aim is to minimize the
processing/backhauling costs at the cloud centre as well as the transmission
power at the RRHs, while satisfying some user quality of service (QoS). This
problem is first formulated as a mixed integer non linear program (MINLP) with
a large number of optimization variables. The underlying NLP is non-convex,
though we address this issue through reformulating the problem using the mean
squared error (MSE)-rate relation. To account to the large-scale of the
problem, we introduce slack variables to decompose the reformulated (MINLP) and
enable the application of a distributed optimization framework by using the
alternating direction method of multipliers (ADMM) algorithm.


title: A neurofeedback system to promote learner engagement

abstract:
  This report describes a series of experiments that track novice programmer's
engagement during two attention based tasks. The tasks required participants to
watch a tutorial video on introductory programming and to attend to a simple
maze game whilst wearing an electroencephalogram (EEG)device called the Emotiv
EPOC. The EPOC's proprietary software includes a system which tracks emotional
state (specifically: engagement, excitement, meditation, frustration, valence
and long-term excitement). Using this data, a software application written in
the Processing language was developed to track user's engagement levels and
implement a neurofeedback based intervention when engagement fell below an
acceptable level. The aim of the intervention was to prompt learners who
disengaged with the task to re-engage. The intervention used during the video
tutorial was to pause the video if a participant disengaged significantly.
However other interventions such as slowing the video down, playing a noise or
darkening/brightening the screen could also be used. For the maze game, the
caterpillar moving through the maze slowed in line with disengagement and moved
more quickly once the learner re-engaged. The approach worked very well and
successfully re-engaged participants, although a number of improvements could
be made. A number of interesting findings on the comparative engagement levels
of different groups e.g. by gender and by age etc. were identified and provide
useful pointers for future research studies.


title: Coherent State Transforms and the Weyl Equation in Clifford Analysis

abstract:
  We study a transform, inspired by coherent state transforms, from the Hilbert
space of Clifford algebra valued square integrable functions $L^2({\mathbb
R}^m,dx)\otimes {\mathbb C}_{m}$ to a Hilbert space of solutions of the Weyl
equation on ${\mathbb R}^{m+1}= {\mathbb R} \times {\mathbb R}^m$, namely to
the Hilbert space ${\mathcal M}L^2({\mathbb R}^{m+1},d\mu)$ of ${\mathbb
C}_m$-valued monogenic functions on ${\mathbb R}^{m+1}$ which are $L^2$ with
respect to an appropriate measure $d\mu$. We prove that this transform is a
unitary isomorphism of Hilbert spaces and that it is therefore an analog of the
Segal-Bargmann transform for Clifford analysis. As a corollary we obtain an
orthonormal basis of monogenic functions on ${\mathbb R}^{m+1}$. We also study
the case when ${\mathbb R}^m$ is replaced by the $m$-torus ${\mathbb T}^m.$
Quantum mechanically, this extension establishes the unitary equivalence of the
Schr\"odinger representation on $M$, for $M={\mathbb R}^m$ and $M={\mathbb
T}^m$, with a representation on the Hilbert space ${\mathcal M}L^2({\mathbb R}
\times M,d\mu)$ of solutions of the Weyl equation on the space-time ${\mathbb
R}\times M$.


title:
Modified top quark condensation model with the extra heavy fermion, the
  $125$ GeV Pseudo - Goldstone boson, and the additional heavy scalar bosons

abstract:
  We discuss the modified top quark condensation model proposed in
\cite{VZ2015}. This construction was inspired by the top - seesaw scenario, in
which the extra heavy fermion $\chi$ is added that may be paired with the top
quark. Besides, this model incorporates the ideas of the Little Higgs scenario,
in which the $125$ GeV scalar particle appears as a Pseudo - Goldstone boson.
This model admits (in addition to the $125$ GeV scalar boson $H$) the heavier
scalar excitation $H^\prime$. We consider the region of parameters, where its
mass is $M_{H^\prime} \sim 1$ TeV, the width of $H^\prime$ is
$\Gamma_{H^\prime} \sim 0.3 M_{H^\prime}$, while the mass of the heavy fermion
is $m_\chi \sim 1$ TeV. We find that in this model the value of the cross -
section $\sigma_{pp \to H^\prime + X \to \gamma+\gamma + X}$ for $\sqrt{s}=13$
TeV is essentially smaller than the present experimental upper bound. Besides,
we find, that for the chosen values of parameters there should exist the CP -
even scalar boson with mass $\approx 2 m_\chi$ and very small width. In
addition, the model predicts the existence of the extra neutral CP even scalar
boson and the charged scalar boson with masses of the order of $1$ TeV.


title: Haze Visibility Enhancement: A Survey and Quantitative Benchmarking

abstract:
  This paper provides a comprehensive survey of methods dealing with visibility
enhancement of images taken in hazy or foggy scenes. The survey begins with
discussing the optical models of atmospheric scattering media and image
formation. This is followed by a survey of existing methods, which are grouped
to multiple image methods, polarizing filters based methods, methods with known
depth, and single-image methods. We also provide a benchmark of a number of
well known single-image methods, based on a recent dataset provided by Fattal
and our newly generated scattering media dataset that contains ground truth
images for quantitative evaluation. To our knowledge, this is the first
benchmark using numerical metrics to evaluate dehazing techniques. This
benchmark allows us to objectively compare the results of existing methods and
to better identify the strengths and limitations of each method.


title:
Current-dependent exchange-correlation potential for non-local
  absorption in quantum hydrodynamic theory

abstract:
  The quantum hydrodynamic theory is a promising method for describing
microscopic details of macroscopic systems. The hydrodynamic equation can be
directly obtained from a single particle Kohn-Sham equation that includes the
contribution of an external vector potential. This derivation allows to
straightforwardly incorporate in the hydrodynamic equation an
exchange-correlation viscoelastic term, so that broadening of collective
excitation can be taken into account, as well as a correction to the plasmon
dispersion. The result is an accurate self-consistent and computationally
efficient hydrodynamic description of the free electron gas. A very accurate
agreement with full quantum calculations is shown.


title: Orbital diamagnetic susceptibility in excitonic condensation phase

abstract:
  We study the orbital diamagnetic susceptibility in excitonic condensation
phase using the meanfield approximation for a two-band model defined on a
square lattice. We find that, in semiconductors, the excitonic condensation
acquires a finite diamagnetic susceptibility due to spontaneous hybridization
between the valence and the conduction bands, whereas in semimetals, the
diamagnetic susceptibility in the normal phase is suppressed by the excitonic
condensation. We also study the orbital diamagnetic and Pauli paramagnetic
susceptibilities of Ta2NiSe5 using a two-dimensional three-band model and find
that the calculated temperature dependence of the magnetic susceptibility is in
qualitative agreement with experiment.


title: Product of generalized $p-$K\"ahler manifolds

abstract:
  A product of K\"ahler manifolds also carries a K\"ahler metric. In this short
note we would like to study the product of generalized $p-$K\"ahler manifolds,
compact or not. The results we get extend the known results (balanced, SKT, sG
manifolds), and are optimal in the compact case. Hence we can give new
non-trivial examples of generalized $p-$K\"ahler manifolds.


title:
High-energy gamma-ray observations of the accreting black hole V404
  Cygni during its June 2015 outburst

abstract:
  We report on Fermi/Large Area Telescope observations of the accreting black
hole low-mass X-ray binary V404 Cygni during its outburst in June-July 2015.
Detailed analyses reveal a possible excess of $\gamma$-ray emission on 26 June
2015, with a very soft spectrum above $100$ MeV, at a position consistent with
the direction of V404 Cyg (within the $95\%$ confidence region and a chance
probability of $4 \times 10^{-4}$). This emission cannot be associated with any
previously-known Fermi source. Its temporal coincidence with the brightest
radio and hard X-ray flare in the lightcurve of V404 Cyg, at the end of the
main active phase of its outburst, strengthens the association with V404 Cyg.
If the $\gamma$-ray emission is associated with V404 Cyg, the simultaneous
detection of $511\,$keV annihilation emission by INTEGRAL requires that the
high-energy $\gamma$ rays originate away from the corona, possibly in a
Blandford-Znajek jet. The data give support to models involving a
magnetically-arrested disk where a bright $\gamma$-ray jet can re-form after
the occurrence of a major transient ejection seen in the radio.


title:
Hybrid Entropy Stable HLL-Type Riemann Solvers for Hyperbolic
  Conservation Laws

abstract:
  It is known that HLL-type schemes are more dissipative than schemes based on
characteristic decompositions. However, HLL-type methods offer greater
flexibility to large systems of hyperbolic conservation laws because the
eigenstructure of the flux Jacobian is not needed. We demonstrate in the
present work that several HLL-type Riemann solvers are provably entropy stable.
Further, we provide convex combinations of standard dissipation terms to create
hybrid HLL-type methods that have less dissipation while retaining entropy
stability. The decrease in dissipation is demonstrated for the ideal MHD
equations with a numerical example.


title: Loewy lengths of centers of blocks

abstract:
  Let B be a block of a finite group with respect to an algebraically closed
field F of characteristic p>0. In a recent paper, Otokita gave an upper bound
for the Loewy length LL(ZB) of the center ZB of B in terms of a defect group D
of B. We refine his methods in order to prove the optimal bound LL(ZB)\le
LL(FD) whenever D is abelian. We also improve Otokita's bound for non-abelian
defect groups. As an application we classify the blocks B such that LL(ZB)\ge
|D|/2.


title:
Observed and Simulated Power Spectra of Kinetic and Magnetic Energy
  retrieved with 2D inversions

abstract:
  We try to retrieve the power spectra with certainty to the highest spatial
frequencies allowed by current instrumentation. For this, we use 2D inversion
code that were able to recover information up to the instrumental diffraction
limit. The retrieved power spectra have shallow slopes extending further down
to much smaller scales than found before. They seem not to show any power law.
The observed slopes at subgranular scales agree with those obtained from recent
local dynamo simulations. Small differences are found for vertical component of
kinetic energy that suggest that observations suffer from an instrumental
effect that is not taken into account.


title: Solution of QCD$\otimes$QED coupled DGLAP equations at NLO

abstract:
  In this work, we present an analytical solution for QCD$\otimes$QED coupled
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations at the
leading order (LO) accuracy in QED and next-to-leading order (NLO) accuracy in
perturbative QCD using double Laplace transform. This technique is applied to
obtain the singlet, gluon and photon distribution functions and also the proton
structure function. We also obtain contribution of photon in proton at LO and
NLO at high energy and successfully compare the proton structure function with
HERA data \cite{12} and APFEL results \cite{7}. Some comparisons also have been
done for the singlet and gluon distribution functions with the MSTW
results\cite{9}. In addition, the contribution of photon distribution function
inside the proton has been compared with results of MRST \cite{11} and with the
contribution of sea quark distribution functions which obtained by MSTW
\cite{9} and CTEQ6M \cite{14}.


title:
The Morse-Bott inequalities, orientations, and the Thom isomorphism in
  Morse homology

abstract:
  The Morse-Bott inequalities relate the topology of a closed manifold to the
topology of the critical point set of a Morse-Bott function defined on it. The
Morse-Bott inequalities are sometimes stated under incorrect orientation
assumptions. We show that these assumptions are insufficient with an explicit
counterexample and clarify the origin of the mistake.


title:
A physical scenario for the high and low X-ray luminosity states in the
  transitional pulsar PSR J1023+0038

abstract:
  PSR J1023+0038 (J1023) is a binary system hosting a neutron star and a low
mass companion. J1023 is the best studied transitional pulsar, alternating a
faint eclipsing millisecond radio pulsar state to a brighter X-ray active
state. At variance with other Low Mass X-ray binaries, this active state
reaches luminosities of only ~$10^{34}$ erg s$^{-1}$, showing strong, fast
variability. In the active state, J1023 displays: i) a high state
($L_X\sim7\times10^{33}$ erg s$^{-1}$, 0.3-80 keV) occurring ~80% of the time
and during which X-ray pulsations at the neutron star spin period are detected
(pulsed fraction ~8%); ii) a low state ($L_X~10^{33}$ erg s$^{-1}$) during
which pulsations are not detected (~<3%); and iii) a flaring state during which
sporadic flares occur in excess of ~$10^{34}$ erg s$^{-1}$, with no pulsation
too. The transition between the high and the low states is very rapid, on a ~10
s timescale. Here we put forward a plausible physical interpretation of the
high and low states based on the (fast) transition among the propeller state
and the radio pulsar state. We modelled the XMM-Newton spectra of the high, low
and radio pulsar states, finding a good agreement with this physical picture.


title:
$L^2$ well-posedness of boundary value problems for parabolic systems
  with measurable coefficients

abstract:
  We prove the first positive results concerning boundary value problems in the
upper half-space of second order parabolic systems only assuming measurability
and some transversal regularity in the coefficients of the elliptic part. To do
so, we introduce and develop a first order strategy by means of a parabolic
Dirac operator at the boundary to obtain, in particular, Green's representation
for solutions in natural classes involving square functions and non-tangential
maximal functions, well-posedness results with data in $L^2$-Sobolev spaces
together with invertibility of layer potentials, and perturbation results. In
the way, we solve the Kato square root problem for parabolic operators with
coefficients of the elliptic part depending measurably on all variables. The
major new challenge, compared to the earlier results by one of us under time
and transversally independence of the coefficients, is to handle non-local
half-order derivatives in time which are unavoidable in our situation.


title: Effects of Sea Level Rise on Economy of the United States

abstract:
  We report the first ex post study of the economic impact of sea level rise.
We apply two econometric approaches to estimate the past effects of sea level
rise on the economy of the USA, viz. Barro type growth regressions adjusted for
spatial patterns and a matching estimator. Unit of analysis is 3063 counties of
the USA. We fit growth regressions for 13 time periods and we estimated
numerous varieties and robustness tests for both growth regressions and
matching estimator. Although there is some evidence that sea level rise has a
positive effect on economic growth, in most specifications the estimated
effects are insignificant. We therefore conclude that there is no stable,
significant effect of sea level rise on economic growth. This finding
contradicts previous ex ante studies.


title: Aggregation Dynamics Using Phase Wave Signals and Branching Patterns

abstract:
  The aggregation dynamics of slime mold is studied using coupled equations of
phase \phi and cell concentration n. Phase waves work as tactic signals for
aggregation. Branching structures appear during the aggregation. A stationary
branching pattern appears like a river network, if cells are uniformly supplied
into the system.


title:
Radiative transfer of acoustic waves in continuous complex media: Beyond
  the Helmholtz equation

abstract:
  Heterogeneity can be accounted for by a random potential in the wave
equation. For acoustic waves in a fluid with fluctuations of both density and
compressibility (as well as for electromagnetic waves in a medium with
fluctuation of both permittivity and permeability) the random potential entails
a scalar and an operator contribution. For simplicity, the latter is usually
overlooked in multiple scattering theory: whatever the type of waves, this
simplification amounts to considering the Helmholtz equation with a sound speed
$c$ depending on position $\mathbf{r}$. In this work, a radiative transfer
equation is derived from the wave equation, in order to study energy transport
through a multiple scattering medium. In particular, the influence of the
operator term on various transport parameters is studied, based on the
diagrammatic approach of multiple scattering. Analytical results are obtained
for fundamental quantities of transport theory such as the transport mean-free
path $\ell^*$, scattering phase function $f$ and anisotropy factor $g$.
Discarding the operator term in the wave equation is shown to have a
significant impact on $f$ and $g$, yet limited to the low-frequency regime
i.e., when the correlation length of the disorder $\ell_c$ is smaller than or
comparable to the wavelength $\lambda$. More surprisingly, discarding the
operator part has a significant impact on the transport mean-free path $\ell^*$
whatever the frequency regime. When the scalar and operator terms have
identical amplitudes, the discrepancy on the transport mean-free path is around
$300\,\%$ in the low-frequency regime, and still above $30\,\%$ for
$\ell_c/\lambda=10^3$ no matter how weak fluctuations of the disorder are.
Analytical results are supported by numerical simulations of the wave equation
and Monte Carlo simulations.


title:
Dynamic Pose-Robust Facial Expression Recognition by Multi-View Pairwise
  Conditional Random Forests

abstract:
  Automatic facial expression classification (FER) from videos is a critical
problem for the development of intelligent human-computer interaction systems.
Still, it is a challenging problem that involves capturing high-dimensional
spatio-temporal patterns describing the variation of one's appearance over
time. Such representation undergoes great variability of the facial morphology
and environmental factors as well as head pose variations. In this paper, we
use Conditional Random Forests to capture low-level expression transition
patterns. More specifically, heterogeneous derivative features (e.g. feature
point movements or texture variations) are evaluated upon pairs of images. When
testing on a video frame, pairs are created between this current frame and
previous ones and predictions for each previous frame are used to draw trees
from Pairwise Conditional Random Forests (PCRF) whose pairwise outputs are
averaged over time to produce robust estimates. Moreover, PCRF collections can
also be conditioned on head pose estimation for multi-view dynamic FER. As
such, our approach appears as a natural extension of Random Forests for
learning spatio-temporal patterns, potentially from multiple viewpoints.
Experiments on popular datasets show that our method leads to significant
improvements over standard Random Forests as well as state-of-the-art
approaches on several scenarios, including a novel multi-view video corpus
generated from a publicly available database.


title: Next generation neural mass models

abstract:
  Neural mass models have been actively used since the 1970s to model the
coarse grained activity of large populations of neurons and synapses. They have
proven especially useful in understanding brain rhythms. However, although
motivated by neurobiological considerations they are phenomenological in
nature, and cannot hope to recreate some of the rich repertoire of responses
seen in real neuronal tissue. In this chapter we consider the $\theta$-neuron
model that has recently been shown to admit to an exact mean-field description
for instantaneous pulsatile interactions. We show that the inclusion of a more
realistic synapse model leads to a mean-field model that has many of the
features of a neural mass model coupled to a further dynamical equation that
describes the evolution of network synchrony. A bifurcation analysis is used to
uncover the primary mechanism for generating oscillations at the single and two
population level. Numerical simulations also show that the phenomena of event
related synchronisation and desynchronisation are easily realised. Importantly
unlike its phenomenological counterpart this \textit{next generation neural
mass model} is an exact macroscopic description of an underlying microscopic
spiking neurodynamics, and is a natural candidate for use in future large scale
human brain simulations.


title:
Strong solutions to the 3D primitive equations with only horizontal
  dissipation: near $H^1$ initial data

abstract:
  In this paper, we consider the initial-boundary value problem of the
three-dimensional primitive equations for oceanic and atmospheric dynamics with
only horizontal viscosity and horizontal diffusivity. We establish the local,
in time, well-posedness of strong solutions, for any initial data $(v_0,
T_0)\in H^1$, by using the local, in space, type energy estimate. We also
establish the global well-posedness of strong solutions for this system, with
any initial data $(v_0, T_0)\in H^1\cap L^\infty$, such that $\partial_zv_0\in
L^m$, for some $m\in(2,\infty)$, by using the logarithmic type anisotropic
Sobolev inequality and a logarithmic type Gronwall inequality. This paper
improves the previous results obtained in [Cao, C.; Li, J.; Titi, E.S.: Global
well-posedness of the 3D primitive equations with only horizontal viscosity and
diffusivity, Comm. Pure Appl.Math., Vol. 69 (2016), 1492-1531.], where the
initial data $(v_0, T_0)$ was assumed to have $H^2$ regularity.

categories: math.AP physics.ao-ph physics.flu-dyn physics.geo-ph


title: Composite Circumstellar Dust Grains

abstract:
  We calculate the absorption efficiencies of composite silicate grains with
inclusions of graphite and silicon carbide in the spectral range 5--25$\rm \mu
m$. We study the variation in absorption profiles with volume fractions of
inclusions. In particular we study the variation in the wavelength of peak
absorption at 10 and 18$\rm \mu m$. We also study the variation of the
absorption of porous silicate grains. We use the absorption efficiencies to
calculate the infrared flux at various dust temperatures and compare with the
observed infrared emission flux from the circumstellar dust around some M-Type
\& AGB stars obtained from IRAS and a few stars from Spitzer satellite. We
interpret the observed data in terms of the circumstellar dust grain sizes;
shape; composition and dust temperature.


title:
Exponential ergodicity of an affine two-factor model based on the
  $\alpha$-root process

abstract:
  We study an affine two-factor model introduced by Barczy et al. (2014). One
component of this two-dimensional model is the so-called $\alpha$-root process,
which generalizes the well known CIR process. In this paper, we show that this
affine two-factor model is exponentially ergodic when $\alpha\in(1,2)$.


title: Jamming in the Internet of Things: A Game-Theoretic Perspective

abstract:
  Due to its scale and largely interconnected nature, the Internet of Things
(IoT) will be vulnerable to a number of security threats that range from
physical layer attacks to network layer attacks. In this paper, a novel
anti-jamming strategy for OFDM-based IoT systems is proposed which enables an
IoT controller to protect the IoT devices against a malicious radio jammer. The
interaction between the controller node and the jammer is modeled as a Colonel
Blotto game with continuous and asymmetric resources in which the IoT
controller, acting as defender, seeks to thwart the jamming attack by
distributing its power among the subcarries in a smart way to decrease the
aggregate bit error rate (BER) caused by the jammer. The jammer, on the other
hand, aims at disrupting the system performance by allocating jamming power to
different frequency bands. To solve the game, an evolutionary algorithm is
proposed which can find a mixed-strategy Nash equilibrium of the Blotto game.
Simulation results show that the proposed algorithm enables the IoT controller
to maintain the BER above an acceptable threshold, thereby preserving the IoT
network performance in the presence of malicious jamming.


title:
The influence of weak lensing on measurements of the Hubble constant
  with quad-image gravitational lenses

abstract:
  We investigate the influence of matter along the line of sight and in the
strong lens vicinity on the properties of quad image configurations and on the
measurements of the Hubble constant (H0). We use simulations of light
propagation in a nonuniform universe model with the distribution of matter in
space based on the data from Millennium Simulation. For a given strong lens and
haloes in its environment we model the matter distribution along the line of
sight many times, using different combinations of precomputed deflection maps
representing subsequent layers of matter on the path of rays. We fit the
simulated quad image configurations with time delays using nonsingular
isothermal ellipsoids (NSIE) with external shear as lens models, treating the
Hubble constant as a free parameter. We get a large artificial catalog of
lenses with derived values of the Hubble constant, Hfit. The average and median
of Hfit differ from the true value used in simulations by < 0.5 km/s/Mpc which
includes the influence of matter along the line of sight and in the lens
vicinity, and uncertainty in lens parameters, except the slope of the matter
distribution, which is fixed. The characteristic uncertainty of Hfit is ~3
km/s/Mpc. Substituting the lens shear parameters with values estimated from the
simulations reduces the uncertainty to ~2 km/s/Mpc.


title: Asymptotical flatness and cone structure at infinity

abstract:
  We investigate asymptotically flat manifolds with cone structure at infinity.
We show that any such manifold M has a finite number of ends. For simply
connected ends we classify all possible cones at infinity, except for the
4-dimensional case where it remains open if one of the theoretically possible
cones can actually arise.
  This result yields in particular a complete classification of asymptotically
flat manifolds with nonnegative curvature: The universal covering of an
asymptotically flat manifold with nonnegative sectional curvature is isometric
to a product of Euclidean space and an asymptotically flat surface.


title: On Composition and Implementation of Sequential Consistency

abstract:
  To implement a linearizable shared memory in synchronous message-passing
systems it is necessary to wait for a time linear to the uncertainty in the
latency of the network for both read and write operations. Waiting only for one
of them suffices for sequential consistency. This paper extends this result to
crash-prone asynchronous systems, proposing a distributed algorithm building a
sequentially consistent shared snapshot memory on top of an asynchronous
message-passing system where less than half of the processes may crash. We
prove that waiting is needed only when a process invokes a read/snapshot right
after a write. We also show that sequential consistency is composable in some
cases commonly encountered: 1) objects that would be linearizable if they were
implemented on top of a linearizable memory become sequentially consistent when
implemented on top of a sequential memory while remaining composable and 2) in
round-based algorithms, where each object is only accessed within one round.


title: N(N)LO event files: applications and prospects

abstract:
  In this contribution we comment on the use of NLO n-Tuples and consider their
extension to NNLO. As an application of n-Tuples we present preliminary results
of a strong coupling extraction from a measurement of the production of Z + 2,
3, 4 jets at the LHC at 7 TeV.


title:
2016 Google Scholar Metrics released: a matter of languages... and
  something else

abstract:
  The 2016 edition of Google Scholar Metrics was released on July 15th 2016.
There haven't been any structural changes respect to previous versions, which
means that most of its limitations still persist. The biggest changes are the
addition of five new language rankings (Russian, Korean, Polish, Ukrainian, and
Indonesian) and elimination of two other language rankings (Italian and Dutch).
In addition, for reasons still unknown, this new edition doesn't include as
many working paper and discussion paper series as previous editions.


title: Conformal scalar and torsion do not go together

abstract:
  We investigate the conformal transformation of vierbein-Einstein-Palatini
(VEP) action in terms of tetrads $e^I_\mu$ and spin connection $A^{IJ}_\mu$.
The transformation of the spin connection is indeterminate off-shell unless
equations of motion are satisfied. We construct the conformally invariant
scalar field in the torsion-free VEP formalism. In presence of fermionic
matter, torsion does not vanish, and shows up in the dynamics of conformal
scalar, affecting the invariance. It is not possible to maintain conformal
invariance of the scalar field equation when fermions are present.


title: Comparison of dark energy models after Planck 2015

abstract:
  We make a comparison for ten typical, popular dark energy models according to
their capabilities of fitting the current observational data. The observational
data we use in this work include the JLA sample of type Ia supernovae
observation, the Planck 2015 distance priors of cosmic microwave background
observation, the baryon acoustic oscillations measurements, and the direct
measurement of the Hubble constant. Since the models have different numbers of
parameters, in order to make a fair comparison, we employ the Akaike and
Bayesian information criteria to assess the worth of the models. The analysis
results show that, according to the capability of explaining observations, the
cosmological constant model is still the best one among all the dark energy
models. The generalized Chaplygin gas model, the constant $w$ model, and the
$\alpha$ dark energy model are worse than the cosmological constant model, but
still are good models compared to others. The holographic dark energy model,
the new generalized Chaplygin gas model, and the Chevalliear-Polarski-Linder
model can still fit the current observations well, but from an economically
feasible perspective, they are not so good. The new agegraphic dark energy
model, the Dvali-Gabadadze-Porrati model, and the Ricci dark energy model are
excluded by the current observations.


title:
Cited References and Medical Subject Headings (MeSH) as Two Different
  Knowledge Representations: Clustering and Mappings at the Paper Level

abstract:
  For the biomedical sciences, the Medical Subject Headings (MeSH) make
available a rich feature which cannot currently be merged properly with widely
used citing/cited data. Here, we provide methods and routines that make MeSH
terms amenable to broader usage in the study of science indicators: using
Web-of-Science (WoS) data, one can generate the matrix of citing versus cited
documents; using PubMed/MEDLINE data, a matrix of the citing documents versus
MeSH terms can be generated analogously. The two matrices can also be
reorganized into a 2-mode matrix of MeSH terms versus cited references. Using
the abbreviated journal names in the references, one can, for example, address
the question whether MeSH terms can be used as an alternative to WoS Subject
Categories for the purpose of normalizing citation data. We explore the
applicability of the routines in the case of a research program about the
amyloid cascade hypothesis in Alzheimer's disease (AD). One conclusion is that
referenced journals provide archival structures, whereas MeSH terms indicate
mainly variation (including novelty) at the research front. Furthermore, we
explore the option of using the citing/cited matrix for main-path analysis as a
by-product of the software.


title: Left/Right Hand Segmentation in Egocentric Videos

abstract:
  Wearable cameras allow people to record their daily activities from a
user-centered (First Person Vision) perspective. Due to their favorable
location, wearable cameras frequently capture the hands of the user, and may
thus represent a promising user-machine interaction tool for different
applications. Existent First Person Vision methods handle hand segmentation as
a background-foreground problem, ignoring two important facts: i) hands are not
a single "skin-like" moving element, but a pair of interacting cooperative
entities, ii) close hand interactions may lead to hand-to-hand occlusions and,
as a consequence, create a single hand-like segment. These facts complicate a
proper understanding of hand movements and interactions. Our approach extends
traditional background-foreground strategies, by including a
hand-identification step (left-right) based on a Maxwell distribution of angle
and position. Hand-to-hand occlusions are addressed by exploiting temporal
superpixels. The experimental results show that, in addition to a reliable
left/right hand-segmentation, our approach considerably improves the
traditional background-foreground hand-segmentation.


title:
The first CO+ image: Probing the HI/H2 layer around the ultracompact HII
  region Mon R2

abstract:
  The CO+ reactive ion is thought to be a tracer of the boundary between a HII
region and the hot molecular gas. In this study, we present the spatial
distribution of the CO+ rotational emission toward the Mon R2 star-forming
region. The CO+ emission presents a clumpy ring-like morphology, arising from a
narrow dense layer around the HII region. We compare the CO+ distribution with
other species present in photon-dominated regions (PDR), such as [CII] 158 mm,
H2 S(3) rotational line at 9.3 mm, polycyclic aromatic hydrocarbons (PAHs) and
HCO+. We find that the CO+ emission is spatially coincident with the PAHs and
[CII] emission. This confirms that the CO+ emission arises from a narrow dense
layer of the HI/H2 interface. We have determined the CO+ fractional abundance,
relative to C+ toward three positions. The abundances range from 0.1 to
1.9x10^(-10) and are in good agreement with previous chemical model, which
predicts that the production of CO+ in PDRs only occurs in dense regions with
high UV fields. The CO+ linewidth is larger than those found in molecular gas
tracers, and their central velocity are blue-shifted with respect to the
molecular gas velocity. We interpret this as a hint that the CO+ is probing
photo-evaporating clump surfaces.


title:
A Liouvile-type theorems for some classes of complete Riemannian almost
  product manifolds and for special mappings of complete Riemannian manifolds

abstract:
  In the present paper we prove Liouville-type theorems: non-existence theorems
for some complete Riemannian almost product manifolds and special mappings of
complete Riemannian manifolds which generalize similar results for compact
manifolds.


title: Fourier frames for singular measures and pure type phenomena

abstract:
  Let $\mu$ be a positive measure on $R^d$. It is known that if the space
$L^2(\mu)$ has a frame of exponentials then the measure $\mu$ must be of "pure
type": it is either discrete, absolutely continuous or singular continuous. It
has been conjectured that a similar phenomenon should be true within the class
of singular continuous measures, in the sense that $\mu$ cannot admit an
exponential frame if it has components of different dimensions. We prove that
this is not the case by showing that the sum of an arc length measure and a
surface measure can have a frame of exponentials. On the other hand we prove
that a measure of this form cannot have a frame of exponentials if the surface
has a point of non-zero Gaussian curvature. This is in spite of the fact that
each "pure" component of the measure separately may admit such a frame.


title: Learning Nominal Automata

abstract:
  We present an Angluin-style algorithm to learn nominal automata, which are
acceptors of languages over infinite (structured) alphabets. The abstract
approach we take allows us to seamlessly extend known variations of the
algorithm to this new setting. In particular we can learn a subclass of nominal
non-deterministic automata. An implementation using a recently developed
Haskell library for nominal computation is provided for preliminary
experiments.


title:
A Survey on Load Balancing Algorithms for VM Placement in Cloud
  Computing

abstract:
  The emergence of cloud computing based on virtualization technologies brings
huge opportunities to host virtual resource at low cost without the need of
owning any infrastructure. Virtualization technologies enable users to acquire,
configure and be charged on pay-per-use basis. However, Cloud data centers
mostly comprise heterogeneous commodity servers hosting multiple virtual
machines (VMs) with potential various specifications and fluctuating resource
usages, which may cause imbalanced resource utilization within servers that may
lead to performance degradation and service level agreements (SLAs) violations.
To achieve efficient scheduling, these challenges should be addressed and
solved by using load balancing strategies, which have been proved to be NP-hard
problem. From multiple perspectives, this work identifies the challenges and
analyzes existing algorithms for allocating VMs to PMs in infrastructure
Clouds, especially focuses on load balancing. A detailed classification
targeting load balancing algorithms for VM placement in cloud data centers is
investigated and the surveyed algorithms are classified according to the
classification. The goal of this paper is to provide a comprehensive and
comparative understanding of existing literature and aid researchers by
providing an insight for potential future enhancements.


title: Lonely points in $\omega^*$

abstract:
  Inspired by the work of J. van Mill we define a new topological type ---
lonely points. We show that the question of whether these points exist in
$\omega^*$ is equivalent to finding a countable OHI, extremally disconnected,
zerodimensional space with a remote weak P-point. We also present methods which
allow us to find lonely points in a large subspace of $\omega^*$ and show why
known methods do not allow us to construct them in all of $\omega^*$.


title:
Interfacing superconducting qubits and single optical photons using
  molecules in waveguides

abstract:
  We propose an efficient light-matter interface at optical frequencies between
a single photon and a superconducting qubit. The desired interface is based on
a hybrid architecture composed of an organic molecule embedded inside an
optical waveguide and electrically coupled to a superconducting qubit placed
near the outside surface of the waveguide. We show that high fidelity,
photon-mediated, entanglement between distant superconducting qubits can be
achieved with incident pulses at the single photon level. Such a low light
level is highly desirable for achieving a coherent optical interface with
superconducting qubit, since it minimizes decoherence arising from the
absorption of light.


title: Flexible focal plane arrays for UVOIR wide field instrumentation

abstract:
  LAM and CEA-LETI are developing the technology of deformable detectors, for
UV, VIS or NIR applications. Such breakthrough devices will be a revolution for
future wide field imagers and spectrographs, firstly by improving the image
quality with better off-axis sharpness, resolution, brightness while scaling
down the optical system, secondly by overcoming the manufacturing issues
identified so far and by offering a flexibility and versatility in optical
design. The technology of curved detectors can benefit of the developments of
active and deformable structures, to provide a flexibility and a fine tuning of
the detectors curvature by thinning down the substrate without modifying the
fabrication process of the active pixels. We present studies done so far on
optical design improvements, the technological demonstrators we developed and
their performances as well as the future five-years roadmap for these
developments.


title: Lonely points revisited

abstract:
  In our previous paper, Lonely points, we introduced the notion of a lonely
point, due to P. Simon. A point $p\in X$ is lonely if it is a limit point of a
countable dense-in-itself set, not a limit point a countable discrete set and
all countable sets whose limit point it is, form a filter. We use the space
${\mathcal G}_\omega$ from a paper of A. Dow, A.V. Gubbi and A. Szyma\'nski
(Rigid Stone spaces within ZFC, Proc. Amer. Math. Soc. 102 (1988), no. 3,
745--748) to construct lonely points in $\omega^*$. This answers the question
of P. Simon posed in our paper Lonely points (Lonely points in $\omega^*$,
Topology Appl. 155 (2008), no. 16, 1766--1771).


title: Topological Data Analysis with Bregman Divergences

abstract:
  Given a finite set in a metric space, the topological analysis generalizes
hierarchical clustering using a 1-parameter family of homology groups to
quantify connectivity in all dimensions. The connectivity is compactly
described by the persistence diagram. One limitation of the current framework
is the reliance on metric distances, whereas in many practical applications
objects are compared by non-metric dissimilarity measures. Examples are the
Kullback-Leibler divergence, which is commonly used for comparing text and
images, and the Itakura-Saito divergence, popular for speech and sound. These
are two members of the broad family of dissimilarities called Bregman
divergences.
  We show that the framework of topological data analysis can be extended to
general Bregman divergences, widening the scope of possible applications. In
particular, we prove that appropriately generalized Cech and Delaunay (alpha)
complexes capture the correct homotopy type, namely that of the corresponding
union of Bregman balls. Consequently, their filtrations give the correct
persistence diagram, namely the one generated by the uniformly growing Bregman
balls. Moreover, we show that unlike the metric setting, the filtration of
Vietoris-Rips complexes may fail to approximate the persistence diagram. We
propose algorithms to compute the thus generalized Cech, Vietoris-Rips and
Delaunay complexes and experimentally test their efficiency. Lastly, we explain
their surprisingly good performance by making a connection with discrete Morse
theory.


title:
Dataset and Neural Recurrent Sequence Labeling Model for Open-Domain
  Factoid Question Answering

abstract:
  While question answering (QA) with neural network, i.e. neural QA, has
achieved promising results in recent years, lacking of large scale real-word QA
dataset is still a challenge for developing and evaluating neural QA system. To
alleviate this problem, we propose a large scale human annotated real-world QA
dataset WebQA with more than 42k questions and 556k evidences. As existing
neural QA methods resolve QA either as sequence generation or
classification/ranking problem, they face challenges of expensive softmax
computation, unseen answers handling or separate candidate answer generation
component. In this work, we cast neural QA as a sequence labeling problem and
propose an end-to-end sequence labeling model, which overcomes all the above
challenges. Experimental results on WebQA show that our model outperforms the
baselines significantly with an F1 score of 74.69% with word-based input, and
the performance drops only 3.72 F1 points with more challenging character-based
input.


title:
Conduction in quasi-periodic and quasi-random lattices: Fibonacci,
  Riemann, and Anderson models

abstract:
  We study the ground state conduction properties of noninteracting electrons
in aperiodic but non-random one-dimensional models with chiral symmetry, and
make comparisons against Anderson models with non-deterministic disorder. The
first model we consider is the Fibonacci lattice, which is a paradigmatic model
of quasicrystals; the second is the Riemann lattice, which we define inspired
by Dyson's proposal on the possible connection between the Riemann hypothesis
and a suitably defined quasicrystal. Our analysis is based on Kohn's
many-particle localization tensor defined within the modern theory of the
insulating state. In the Fibonacci quasicrystal, where all single-particle
eigenstates are critical (i.e., intermediate between ergodic and localized),
the noninteracting electron gas is found to be a conductor at most electron
densities, including the half-filled case; however, at various specific
fillings $\rho$, including the values $\rho = 1/g^n$, where $g$ is the golden
ratio and $n$ is any integer, the gas turns into an insulator due to spectral
gaps. Metallic behaviour is found at half-filling in the Riemann lattice as
well; however, in contrast to the Fibonacci quasicrystal, the Riemann lattice
is generically an insulator due to single-particle eigenstate localization,
likely at all other fillings. Its behaviour turns out to be alike that of the
off-diagonal Anderson model, albeit with different system-size scaling of the
band-centre anomalies. The advantages of analysing the Kohn's localization
tensor instead of other measures of localization familiar from the theory of
Anderson insulators (such as the participation ratio or the Lyapunov exponent)
are highlighted.


title: Strain-gradient mapping of semiconductor quantum dots

abstract:
  In the context of fast developing quantum technologies, locating single
quantum objects embedded in solid or fluid environment while keeping their
properties unchanged is a crucial requirement as well as a challenge. Such
"quantum microscopes" have been demonstrated already for NV-centers embedded in
diamond [1], and for single atoms within an ultracold gas [2]. In this work, we
demonstrate a new method to determine non-destructively the position of
randomly distributed semiconductor quantum dots (QDs) deeply embedded in a
solid photonic waveguide. By setting the wire in an oscillating motion, we
generate large stress gradients across the QDs plane. We then exploit the fact
that the QDs emission frequency is highly sensitive to the local material
stress [3-5] to infer their positions with an accuracy ranging from +/- 35 nm
down to +/-1 nm for close-to-axis QDs.


title:
Solutions in the generalized Proca theory with the nonminimal coupling
  to the Einstein tensor

abstract:
  We investigate the static and spherically symmetric solutions in a class of
the generalized Proca theory with the nonminimal coupling to the Einstein
tensor. First, we show that the solutions in the scalar-tensor theory with the
nonminimal derivative coupling to the Einstein tensor can be those in the
generalized Proca theory with the vanishing field strength. We then show that
when the field strength takes the nonzero value the static and spherically
symmetric solutions can be found only for the specific value of the nonminimal
coupling constant. Second, we investigate the first-order slow-rotation
corrections to the static and spherically symmetric background. We find that
for the background with the vanishing electric field strength the slowly
rotating solution is identical to the Kerr- (anti-) de Sitter solutions in
general relativity. On the other hand, for the background with the nonvanishing
electric field strength the stealth property can realized at the first order in
the slow-rotation approximation.


title: Estimating the index of summability of pairs of Banach spaces

abstract:
  Let $E_{1},...,E_{m},F$ be Banach spaces. The index of summability of
$\left(E_{1}\times\cdots\times E_{m},F\right) $ is a kind of measure of how far
the $m$-linear operators $T:E_{1}\times\cdots\times E_{m}\rightarrow F$ are
from being multiple summing. In this paper we estimate the index of summability
of several pairs of Banach spaces$.$


title: Explaining Classification Models Built on High-Dimensional Sparse Data

abstract:
  Predictive modeling applications increasingly use data representing people's
behavior, opinions, and interactions. Fine-grained behavior data often has
different structure from traditional data, being very high-dimensional and
sparse. Models built from these data are quite difficult to interpret, since
they contain many thousands or even many millions of features. Listing features
with large model coefficients is not sufficient, because the model coefficients
do not incorporate information on feature presence, which is key when analysing
sparse data. In this paper we introduce two alternatives for explaining
predictive models by listing important features. We evaluate these alternatives
in terms of explanation "bang for the buck,", i.e., how many examples'
inferences are explained for a given number of features listed. The bottom
line: (i) The proposed alternatives have double the bang-for-the-buck as
compared to just listing the high-coefficient features, and (ii) interestingly,
although they come from different sources and motivations, the two new
alternatives provide strikingly similar rankings of important features.


title: Isometry groups and mapping class groups of spherical 3-orbifolds

abstract:
  We study the isometry groups of compact spherical orientable $3$-orbifolds
$S^3/G$, where $G$ is a finite subgroup of $\mathrm{SO}(4)$, by determining
their isomorphism type. Moreover, we prove that the inclusion of
$\mbox{Isom}(S^3/G)$ into $\mbox{Diff}(S^3/G)$ induces an isomorphism of the
$\pi_0$ groups, thus proving the $\pi_0$-part of the natural generalization of
the Smale Conjecture to spherical $3$-orbifolds.


title: Simulating the Impact of X-ray Heating during the Cosmic Dawn

abstract:
  Upcoming observations of the 21-cm signal from the Epoch of Reionization will
soon provide the first direct detection of this era. This signal is influenced
by many astrophysical effects, including long range X-ray heating of the
intergalactic gas. During the preceding Cosmic Dawn era the impact of this
heating on the 21-cm signal is particularly prominent, especially before spin
temperature saturation. We present the largest-volume (349\,Mpc
comoving=244~$h^{-1}$Mpc) full numerical radiative transfer simulations to date
of this epoch that include the effects of helium and multi-frequency heating,
both with and without X-ray sources. We show that X-ray sources contribute
significantly to early heating of the neutral intergalactic medium and, hence,
to the corresponding 21-cm signal. The inclusion of hard, energetic radiation
yields an earlier, extended transition from absorption to emission compared to
the stellar-only case. The presence of X-ray sources decreases the absolute
value of the mean 21-cm differential brightness temperature. These hard sources
also significantly increase the 21-cm fluctuations compared the common
assumption of temperature saturation. The 21-cm differential brightness
temperature power spectrum is initially boosted on large scales, before
decreasing on all scales. Compared to the case of the cold, unheated
intergalactic medium, the signal has lower rms fluctuations and increased
non-Gaussianity, as measured by the skewness and kurtosis of the 21-cm
probability distribution functions. Images of the 21-cm signal with resolution
around 11~arcmin still show fluctuations well above the expected noise for deep
integrations with the SKA1-Low, indicating that direct imaging of the X-ray
heating epoch could be feasible.


title:
Real-Time Intensity-Image Reconstruction for Event Cameras Using
  Manifold Regularisation

abstract:
  Event cameras or neuromorphic cameras mimic the human perception system as
they measure the per-pixel intensity change rather than the actual intensity
level. In contrast to traditional cameras, such cameras capture new information
about the scene at MHz frequency in the form of sparse events. The high
temporal resolution comes at the cost of losing the familiar per-pixel
intensity information. In this work we propose a variational model that
accurately models the behaviour of event cameras, enabling reconstruction of
intensity images with arbitrary frame rate in real-time. Our method is
formulated on a per-event-basis, where we explicitly incorporate information
about the asynchronous nature of events via an event manifold induced by the
relative timestamps of events. In our experiments we verify that solving the
variational model on the manifold produces high-quality images without
explicitly estimating optical flow.


title:
On the Dirichlet to Neumann Problem for the 1-dimensional Cubic NLS
  equation on the Half-Line; Non-zero Initial Data

abstract:
  Initial-boundary value problems for 1-dimensional `completely integrable'
equations can be solved via an extension of the inverse scattering method,
which is due to Fokas and his collaborators. A crucial feature of this method
is that it requires the values of more boundary data than given for a
well-posed problem. In the case of cubic NLS, knowledge of the Dirichet data
suffices to make the problem well-posed but the Fokas method also requires
knowledge of the values of Neumann data. The study of the Dirichlet to Neumann
map is thus necessary before the application of the `Fokas transform'. In this
paper, we provide a rigorous study of this map for a large class of decaying
Dirichlet data. We show that the Neumann data are also sufficiently decaying
and hence that the Fokas method can be applied.
  This is an addendum to a previous paper. We consider the case of non-zero
initial data, thus completing the discussion of the previous paper.


title: Do branch lengths help to locate a tree in a phylogenetic network?

abstract:
  Phylogenetic networks are increasingly used in evolutionary biology to
represent the history of species that have undergone reticulate events such as
horizontal gene transfer, hybrid speciation and recombination. One of the most
fundamental questions that arise in this context is whether the evolution of a
gene with one copy in all species can be explained by a given network. In
mathematical terms, this is often translated in the following way: is a given
phylogenetic tree contained in a given phylogenetic network? Recently this tree
containment problem has been widely investigated from a computational
perspective, but most studies have only focused on the topology of the phylo-
genies, ignoring a piece of information that, in the case of phylogenetic
trees, is routinely inferred by evolutionary analyses: branch lengths. These
measure the amount of change (e.g., nucleotide substitutions) that has occurred
along each branch of the phylogeny. Here, we study a number of versions of the
tree containment problem that explicitly account for branch lengths. We show
that, although length information has the potential to locate more precisely a
tree within a network, the problem is computationally hard in its most general
form. On a positive note, for a number of special cases of biological
relevance, we provide algorithms that solve this problem efficiently. This
includes the case of networks of limited complexity, for which it is possible
to recover, among the trees contained by the network with the same topology as
the input tree, the closest one in terms of branch lengths.


title:
On the Dirichlet to Neumann Problem for the 1-dimensional Cubic NLS
  equation on the Half-Line; Zero Initial Data

abstract:
  Initial-boundary value problems for 1-dimensional `completely integrable'
equations can be solved via an extension of the inverse scattering method,
which is due to Fokas and his collaborators. A crucial feature of this method
is that it requires the values of more boundary data than given for a
well-posed problem. In the case of cubic NLS, knowledge of the Dirichet data
suffices to make the problem well-posed but the Fokas method also requires
knowledge of the values of Neumann data. The study of the Dirichlet to Neumann
map is thus necessary before the application of the `Fokas transform'. In this
paper, we provide a rigorous study of this map for a large class of decaying
Dirichlet data. We show that the Neumann data are also sufficiently decaying
and hence that the Fokas method can be applied.
  For simplicity we considered here the case of zero initial data. An addendum
will follow, discussing the case of non-zero initial data.


title:
Sun-to-Earth Characteristics of the 2012 July 12 Coronal Mass Ejection
  and Associated Geo-effectiveness

abstract:
  We analyze multi-spacecraft observations associated with the 2012 July 12
Coronal Mass Ejection (CME), covering the source region on the Sun from SDO,
stereoscopic imaging observations from STEREO, magnetic field characteristics
at MESSENGER, and type II radio burst and in situ measurements from Wind. A
triangulation method based on STEREO stereoscopic observations is employed to
determine the kinematics of the CME, and the outcome is compared with the
result derived from the type II radio burst with a solar wind electron density
model. A Grad-Shafranov technique is applied to Wind in situ data to
reconstruct the flux-rope structure and compare it with the observation of the
solar source region, which helps understand the geo-effectiveness associated
with the CME structure. Conclusions are as follows: (1) the CME undergoes an
impulsive acceleration, a rapid deceleration before reaching MESSENGER, and
then a gradual deceleration out to 1 AU, which should be noticed in CME
kinematics models; (2) the type II radio burst was probably produced from a
high-density interaction region between the CME-driven shock and a nearby
streamer or from the shock flank with lower heights, which implies
uncertainties in the determination of CME kinematics using solely type II radio
bursts; (3) the flux-rope orientation and chirality deduced from in situ
reconstruction at Wind agree with those obtained from solar source
observations; (4) the prolonged southward magnetic field near the Earth is
mainly from the axial component of the largely southward inclined flux rope,
which indicates the importance of predicting both the flux-rope orientation and
magnetic field components in geomagnetic activity forecasting.


title:
Point patterns occurring on complex structures in space and space-time:
  An alternative network approach

abstract:
  This paper presents an alternative approach of analyzing possibly multitype
point patterns in space and space-time that occur on network structures, and
introduces several different graph-related intensity measures. The proposed
formalism allows to control for processes on undirected, directional as well as
partially directed network structures and is not restricted to linearity or
circularity.


title: The Noisy Oscillator : Random Mass and Random Damping

abstract:
  The problem of a linear damped noisy oscillator is treated in the presence of
two multiplicative sources of noise which imply a random mass and random
damping. The additive noise and the noise in the damping are responsible for an
influx of energy to the oscillator and its dissipation to the surrounding
environment. A random mass implies that the surrounding molecules not only
collide with the oscillator but may also adhere to it, thereby changing its
mass. We present general formulas for the first two moments and address the
question of mean and energetic stabilities. The phenomenon of stochastic
resonance, i.e. the expansion due to the noise of a system response to an
external periodic signal, is considered for separate and joint action of two
sources of noise and their characteristics.


title:
Confidence-Weighted Local Expression Predictions for Occlusion Handling
  in Expression Recognition and Action Unit detection

abstract:
  Fully-Automatic Facial Expression Recognition (FER) from still images is a
challenging task as it involves handling large interpersonal morphological
differences, and as partial occlusions can occasionally happen. Furthermore,
labelling expressions is a time-consuming process that is prone to
subjectivity, thus the variability may not be fully covered by the training
data. In this work, we propose to train Random Forests upon spatially defined
local subspaces of the face. The output local predictions form a categorical
expression-driven high-level representation that we call Local Expression
Predictions (LEPs). LEPs can be combined to describe categorical facial
expressions as well as Action Units (AUs). Furthermore, LEPs can be weighted by
confidence scores provided by an autoencoder network. Such network is trained
to locally capture the manifold of the non-occluded training data in a
hierarchical way. Extensive experiments show that the proposed LEP
representation yields high descriptive power for categorical expressions and AU
occurrence prediction, and leads to interesting perspectives towards the design
of occlusion-robust and confidence-aware FER systems.


title: Matroids from hypersimplex splits

abstract:
  A class of matroids is introduced which is very large as it strictly contains
all paving matroids as special cases. As their key feature these split matroids
can be studied via techniques from polyhedral geometry. It turns out that the
structural properties of the split matroids can be exploited to obtain new
results in tropical geometry, especially on the rays of the tropical
Grassmannians.


title: The muon magnetic moment in the 2HDM: complete two-loop result

abstract:
  We study the ${\text{2HDM}}$ contribution to the muon anomalous magnetic
moment $a_\mu$ and present the complete two-loop result, particularly for the
bosonic contribution. We focus on the Aligned ${\text{2HDM}}$, which has
general Yukawa couplings and contains the type I, II, X, Y models as special
cases. The result is expressed with physical parameters: three Higgs boson
masses, Yukawa couplings, two mixing angles, and one quartic potential
parameter. We show that the result can be split into several parts, each of
which has a simple parameter dependence, and we document their general
behavior. Taking into account constraints on parameters, we find that the full
${\text{2HDM}}$ contribution to $a_\mu$ can accommodate the current
experimental value, and the complete two-loop bosonic contribution can amount
to $(2\cdots 4)\times 10^{-10}$, more than the future experimental uncertainty.


title:
Spin-charge transformation of lattice fermion models: duality approach
  for diagrammatic simulation of strongly correlated systems

abstract:
  I derive a dual description of lattice fermions, specifically focusing on the
t-J and Hubbard models, that allow diagrammatic techniques to be employed
efficiently in the strongly correlated regime, as well as for systems with a
restricted Hilbert space. These constructions are based on spin-charge
transformation, where the lattice fermions of the original model are mapped
onto spins and spin-less fermions. This mapping can then be combined with
Popov-Fedotov fermionisation, where the spins are mapped onto lattice fermions
with imaginary chemical potential. The resulting models do not contain any
large expansion parameters, even for strongly correlated systems. Also, they
exhibit dramatically smaller corrections to the density matrix from nonlinear
terms in the Hamiltonian. The combination of these two properties means that
they can be addressed with diagrammatic methods, including simulation
techniques based on stochastic sampling of diagrammatic expansions.


title: Hierarchical Clustering of Asymmetric Networks

abstract:
  This paper considers networks where relationships between nodes are
represented by directed dissimilarities. The goal is to study methods that,
based on the dissimilarity structure, output hierarchical clusters, i.e., a
family of nested partitions indexed by a connectivity parameter. Our
construction of hierarchical clustering methods is built around the concept of
admissible methods, which are those that abide by the axioms of value - nodes
in a network with two nodes are clustered together at the maximum of the two
dissimilarities between them - and transformation - when dissimilarities are
reduced, the network may become more clustered but not less. Two particular
methods, termed reciprocal and nonreciprocal clustering, are shown to provide
upper and lower bounds in the space of admissible methods. Furthermore,
alternative clustering methodologies and axioms are considered. In particular,
modifying the axiom of value such that clustering in two-node networks occurs
at the minimum of the two dissimilarities entails the existence of a unique
admissible clustering method.


title:
Localization phenomena in interacting Rydberg lattice gases with
  position disorder

abstract:
  Disordered systems provide paradigmatic instances of ergodicity breaking and
localization phenomena. Here we explore the dynamics of excitations in a system
of Rydberg atoms held in optical tweezers. The finite temperature produces an
intrinsic uncertainty in the atomic positions, which translates into quenched
correlated disorder in the interatomic interaction strengths. In a simple
approach, the dynamics in the many-body Hilbert space can be understood in
terms of a one-dimensional Anderson-like model with disorder on every other
site, featuring both localized and delocalized states. We conduct an experiment
on an eight-atom chain and observe a clear suppression of excitation transfer.
Our experiment accesses a regime which is described by a two-dimensional
Anderson model on a "trimmed" square lattice. Our results thus provide a
concrete example in which the absence of excitation propagation in a many-body
system is directly related to Anderson-like localization in the Hilbert space,
which is believed to be the mechanism underlying many-body localization.

categories: cond-mat.quant-gas cond-mat.dis-nn cond-mat.str-el physics.atom-ph quant-ph


title: Cosmological Tests with the FSRQ Gamma-ray Luminosity Function

abstract:
  The extensive catalog of $\gamma$-ray selected flat-spectrum radio quasars
(FSRQs) produced by \emph{Fermi} during a four-year survey has generated
considerable interest in determining their $\gamma$-ray luminosity function
(GLF) and its evolution with cosmic time. In this paper, we introduce the novel
idea of using this extensive database to test the differential volume expansion
rate predicted by two specific models, the concordance $\Lambda$CDM and $R_{\rm
h}=ct$ cosmologies. For this purpose, we use two well-studied formulations of
the GLF, one based on pure luminosity evolution (PLE) and the other on a
luminosity-dependent density evolution (LDDE). Using a Kolmogorov-Smirnov test
on one-parameter cumulative distributions (in luminosity, redshift, photon
index and source count), we confirm the results of earlier works showing that
these data somewhat favour LDDE over PLE; we show that this is the case for
both $\Lambda$CDM and $R_{\rm h}=ct$. Regardless of which GLF one chooses,
however, we also show that model selection tools very strongly favour $R_{\rm
h}=ct$ over $\Lambda$CDM. We suggest that such population studies, though
featuring a strong evolution in redshift, may nonetheless be used as a valuable
independent check of other model comparisons based solely on geometric
considerations.


title: Global regularity properties of steady shear thinning flows

abstract:
  In this paper we study the regularity of weak solutions to systems of
p-Stokes type, describing the motion of some shear thinning fluids in certain
steady regimes. In particular we address the problem of regularity up to the
boundary improving previous results especially in terms of the allowed range
for the parameter p.


title: Solar system dynamics in general relativity

abstract:
  Recent work in the literature has advocated using the Earth-Moon-planetoid
Lagrangian points as observables, in order to test general relativity and
effective field theories of gravity in the solar system. However, since the
three-body problem of classical celestial mechanics is just an approximation of
a much more complicated setting, where all celestial bodies in the solar system
are subject to their mutual gravitational interactions, while solar radiation
pressure and other sources of nongravitational perturbations also affect the
dynamics, it is conceptually desirable to improve the current understanding of
solar system dynamics in general relativity, as a first step towards a more
accurate theoretical study of orbital motion in the weak-gravity regime. For
this purpose, starting from the Einstein equations in the de Donder-Lanczos
gauge, this paper arrives first at the Levi-Civita Lagrangian for the geodesic
motion of celestial bodies, showing in detail under which conditions the
effects of internal structure and finite extension get cancelled in general
relativity to first post-Newtonian order. The resulting nonlinear ordinary
differential equations for the motion of planets and satellites are solved for
the Earth's orbit about the Sun, written down in detail for the Sun-Earth-Moon
system, and investigated for the case of planar motion of a body immersed in
the gravitational field produced by the other bodies (e.g. planets with their
satellites). At this stage, we prove an exact property, according to which the
fourth-order time derivative of the original system leads to a linear system of
ordinary differential equations. This opens an interesting perspective on
forthcoming research on planetary motions in general relativity within the
solar system, although the resulting equations remain a challenge for numerical
and qualitative studies.


title: Opinion Mining in Online Reviews About Distance Education Programs

abstract:
  The popularity of distance education programs is increasing at a fast pace.
En par with this development, online communication in fora, social media and
reviewing platforms between students is increasing as well. Exploiting this
information to support fellow students or institutions requires to extract the
relevant opinions in order to automatically generate reports providing an
overview of pros and cons of different distance education programs. We report
on an experiment involving distance education experts with the goal to develop
a dataset of reviews annotated with relevant categories and aspects in each
category discussed in the specific review together with an indication of the
sentiment.
  Based on this experiment, we present an approach to extract general
categories and specific aspects under discussion in a review together with
their sentiment. We frame this task as a multi-label hierarchical text
classification problem and empirically investigate the performance of different
classification architectures to couple the prediction of a category with the
prediction of particular aspects in this category. We evaluate different
architectures and show that a hierarchical approach leads to superior results
in comparison to a flat model which makes decisions independently.


title:
Teichm\"uller space of circle diffeomorphisms with H\"older continuous
  derivatives

abstract:
  Based on the quasiconformal theory of the universal Teichm\"uller space, we
introduce the Teichm\"uller space of diffeomorphisms of the unit circle with
$\alpha$-H\"older continuous derivatives as a subspace of the universal
Teichm\"uller space. We characterize such a diffeomorphism quantitatively in
terms of the complex dilatation of its quasiconformal extension and the
Schwarzian derivative given by the Bers embedding. Then, we provide a complex
Banach manifold structure for it and prove that its topology coincides with the
one induced by local $C^{1+\alpha}$-topology at the base point.


title: Benjamin-Feir instabilities on directed networks

abstract:
  The Complex Ginzburg-Landau equation is studied assuming a directed network
of coupled oscillators. The asymmetry makes the spectrum of the Laplacian
operator complex, and it is ultimately responsible for the onset of a
generalized class of topological instability, reminiscent of the Benjamin-Feir
type. The analysis is initially carried out for a specific class of networks,
characterized by a circulant adjacency matrix. This allows us to delineate
analytically the domain in the parameter space for which the generalized
instability occurs. We then move forward to considering the family of non
linear oscillators coupled via a generic direct, though balanced, graph. The
characteristics of the emerging patterns are discussed within a self-consistent
theoretical framework.


title: Random Beamforming in Millimeter-Wave NOMA Networks

abstract:
  This paper investigates the coexistence between two key enabling technologies
for the fifth generation (5G) mobile networks, non-orthogonal multiple access
(NOMA) and millimeter-wave (mmWave) communications. Particularly, the
application of random beamforming to the addressed mmWave-NOMA scenario is
considered in this paper, in order to avoid the requirement that the base
station knows all the users' channel state information. Stochastic geometry is
used to characterize the performance of the proposed mmWave-NOMA transmission
scheme, by using the key features of mmWave systems, e.g., mmWave transmission
is highly directional and potential blockages will thin the user distribution.
Two random beamforming approaches which can further reduce the system overhead
are also proposed to the addressed mmWave-NOMA communication scenario, where
their performance is studied by developing analytical results about sum rates
and outage probabilities. Simulation results are also provided to demonstrate
the performance of the proposed mmWave-NOMA transmission schemes and verify the
accuracy of the developed analytical results.


title:
High-Performance Algorithms for Computing the Sign Function of
  Triangular Matrices

abstract:
  Algorithms and implementations for computing the sign function of a
triangular matrix are fundamental building blocks in algorithms for computing
the sign of arbitrary square real or complex matrices. We present novel
recursive and cache efficient algorithms that are based on Higham's stabilized
specialization of Parlett's substitution algorithm for computing the sign of a
triangular matrix. We show that the new recursive algorithms are asymptotically
optimal in terms of the number of cache misses that they generate. One of the
novel algorithms that we present performs more arithmetic than the
non-recursive version, but this allows it to benefit from calling
highly-optimized matrix-multiplication routines; the other performs the same
number of operations as the non-recursive version, but it uses custom
computational kernels instead. We present implementations of both, as well as a
cache-efficient implementation of a block version of Parlett's algorithm. Our
experiments show that the blocked and recursive versions are much faster than
the previous algorithms, and that the inertia strongly influences their
relative performance, as predicted by our analysis.


title:
Dynamical formation of a Reissner-Nordstr\"om black hole with scalar
  hair in a cavity

abstract:
  In a recent letter, we presented numerical relativity simulations, solving
the full Einstein--Maxwell--Klein-Gordon equations, of superradiantly unstable
Reissner-Nordstr\"om black holes (BHs), enclosed in a cavity. Low frequency,
spherical perturbations of a charged scalar field, trigger this instability.
The system's evolution was followed into the non-linear regime, until it
relaxed into an equilibrium configuration, found to be a $\textit{hairy}$ BH: a
charged horizon in equilibrium with a scalar field condensate, whose phase is
oscillating at the (final) critical frequency. Here, we investigate the impact
of adding self-interactions to the scalar field. In particular, we find
sufficiently large self-interactions suppress the exponential growth phase,
known from linear theory, and promote a non-monotonic behaviour of the scalar
field energy. Furthermore, we discuss in detail the influence of the various
parameters in this model: the initial BH charge, the initial scalar
perturbation, the scalar field charge, mass, and the position of the cavity's
boundary (mirror). We also investigate the "explosive" non-linear regime
previously reported to be akin to a bosenova. A mode analysis shows that the
"explosions" can be interpreted as the decay into the BH of modes that exit the
superradiant regime.


title:
Measurement of polarization observables of the associated strangeness
  production in proton proton interactions

abstract:
  The Lambda polarization, the analyzing power, and the Lambda spin transfer
coefficient of the reaction pp -> p K+ Lambda were measured at beam momenta of
2.70 GeV/c and 2.95 GeV/c, corresponding to excess energies of 122 MeV and 204
MeV. While the analyzing power and the spin transfer coefficient do not change
significantly with the excess energy, the Lambda polarization varies strongly
and changes its sign. As this is the first measurement of polarization
observables below an excess energy of 200 MeV, the change of the sign of the
Lambda polarization was not observed before. The high statistics of the data
(~200 k events for each momentum) enables detailed studies of the dependence of
the Lambda polarization and the analyzing power on the center of mass momentum
of the particles. The results of the spin transfer coefficient are in
qualitative agreement with the DISTO experiment. The Lambda polarization data
of 2.95 GeV/c are only conform with the DISTO experiment, while both the 2.70
GeV/c and 2.95 GeV/c data differ strongly from all previous measurements,
whether exclusive or inclusive.


title: Complex interpolation of $\mathbb{R}$-norms, duality and foliations

abstract:
  The complex method of interpolation, going back to Calder\'on and Coifman et
al., on the one hand, and the Alexander-Wermer-Slodkowski theorem on polynomial
hulls with convex fibers, on the other hand, are generalized to a method of
interpolation of real (finite-dimensional) Banach spaces and of convex
functions. The underlying duality in this method is given by the Legendre
transform. Our results can also be interpreted as new properties of solutions
of the homogeneous complex Monge-Amp\`ere equation.


title:
Estimating the unobservable moose - converting index to population size
  using a Bayesian Hierarchical state space model

abstract:
  Indirect information on population size, like pellet counts or volunteer
counts, is the main source of information in most ecological studies and
applied population management situations. Often, such observations are treaded
as if they were actual measurements of population size. This assumption results
in incorrect conclusions about a population's size and its dynamics. We propose
a model with a temporal varying link, denoted countability, between indirect
observations and actual population size. We show that, when indirect
measurement has high precision (for instance many observation hours) the
assumption of temporal varying countability can have a crucial effect on the
estimated population dynamic. We apply the model on two local moose populations
in Sweden. The estimated population dynamics is found to explain 30-50 percent
of the total variability in the observation data; thus, countability accounts
for most of the variation. This unreliability of the estimated dynamics has a
substantial negative impact on the ability to manage populations; for example,
reducing (increasing) the number of animals that needs to be harvested in order
to sustain the population above (below) a fixed level. Finally, large
difference in countability between two study areas implies a substantial
spatial variation in the countability; this variation in itself is highly
worthy of study.


title: Time-Dependent Tomographic Reconstruction of the Solar Corona

abstract:
  Solar rotational tomography (SRT) applied to white-light coronal images
observed at multiple aspect angles has been the preferred approach for
determining the three-dimensional (3D) electron density structure of the solar
corona. However, it is seriously hampered by the restrictive assumption that
the corona is time-invariant which introduces significant errors in the
reconstruction. We first explore several methods to mitigate the temporal
variation of the corona by decoupling the "fast-varying" inner corona from the
"slow-moving" outer corona using multiple masking (either by juxtaposition or
recursive combination) and radial weighting. Weighting with a radial
exponential profile provides some improvement over a classical reconstruction
but only beyond 3 Rsun. We next consider a full time-dependent tomographic
reconstruction involving spatio-temporal regularization and further introduce a
co-rotating regularization aimed at preventing concentration of reconstructed
density in the plane of the sky. Crucial to testing our procedure and properly
tuning the regularization parameters is the introduction of a time-dependent
MHD model of the corona based on observed magnetograms to build a time-series
of synthetic images of the corona. Our procedure, which successfully reproduces
the time-varying model corona, is finally applied to a set of of 53 LASCO-C2 pB
images roughly evenly spaced in time from 15 to 29 March 2009. Our procedure
paves the way to a time-dependent tomographic reconstruction of the coronal
electron density to the whole set of LASCO-C2 images presently spanning 20
years.


title:
The 2016 outburst of the unique symbiotic star MWC 560 (= V694 Mon), its
  long-term BVRI evolution and a marked 331 days periodicity

abstract:
  After 26 years from the major event of 1990, in early 2016 the puzzling
symbiotic binary MWC 560 has gone into a new and even brighter outburst. We
present our tight BVRI photometric monitoring of MWC 560 (451 independent runs
distributed over 357 different nights), covering the 2005-2016 interval, and
the current outburst in particoular. A stricking feature of the 2016 outburst
has been the suppression of the short term chaotic variability during the rise
toward maximum brightness, and its dominance afterward with an amplitude in
excess of 0.5 mag. Similar to the 1990 event when the object remained around
maximum brightness for ~6 months, at the time Solar conjunction prevented
further observations of the current outburst, MWC 560 was still around maximum,
three months past reaching it. We place our observations into a long term
contex by combining with literature data to provide a complete 1928-2016
lightcurve. Some strong periodicities are found to modulate the optical
photometry of MWC 560. A period of 1860 days regulate the occourence of bright
phases at BVR bands (with exactly 5.0 cycles separating the 1990 and 2016
outbursts), while the peak brightness attained during bright phases seems to
vary with a ~9570 days cycle. A clean 331 day periodicity modulate the I-band
lightcurve, where the emission from the M giant dominates, with a lightcurve
strongly reminiscent of an ellipsoidal distortion plus irradiation from the hot
companion. Pros and cons of 1860 and 331 days as the system orbital period are
reviewed, waiting for a spectroscopic radial velocity orbit of the M giant to
settle the question (provided the orbit is not oriented face-on).


title:
Continuity of the barycentric extension of circle diffeomorphisms of
  H\"older continuous derivatives

abstract:
  The barycentric extension due to Douady and Earle gives a conformally natural
extension of a quasisymmetric automorphism of the circle to a quasiconformal
automorphism of the unit disk. We consider such extensions for circle
diffeomorphisms of H\"older continuous derivatives and show that this operation
is continuous with respect to an appropriate topology for the space of the
corresponding Beltrami coefficients.


title: Positivity and unitarity constraints on dipole gluon distributions

abstract:
  In the high-energy domain, gluon transverse-momentum dependent distributions
in nuclei obey constraints coming from positivity and unitarity of the
colorless QCD dipole distributions through Fourier-Bessel transformations.
Using mathematical properties of Fourier-positive functions, we investigate the
nature of these constraints which apply to dipole model building and
formulation


title:
Historical light-curve and the 2016 outburst of the symbiotic star StHa
  169

abstract:
  Accurate BVRI optical photometry of StHa 169 has been collected during the
period 2005-2016. It reveals two outbursts, in 2009 and 2016, both peaking at
B=13.6. The mean brightness in quiescence was B=15.29. In response to the 2016
outburst, the integrated absolute flux of the emission lines increased by a
factor of 7 for Balmer, 9 for HeI lines, and 4.5 for HeII 4686, the Balmer
continuum turned into strong emission, and [NeV] 3526 and OVI Raman 6825 Ang
emissions disappeared. We have reconstructed the 1897-1951 B-band lightcurve of
StHa 169 from Harvard historical plates. On top of a slow decline from a large
outburst, ending in 1916, several brightenings are visible. Two fast-evolving
outbursts, separated by 510 days, occurred in 1934 and 1935, peaking at B=13.7.
The brightness in quiescence was the same as we measured in 2005-2016


title: On Optimal Heterogeneous Regenerating Codes

abstract:
  Heterogeneous Distributed Storage Systems (DSSs) are close to the real world
applications for data storage. Each node of the considered DSS, may store
different number of packets and each having different repair bandwidth with
uniform repair traffic. For such heterogeneous DSS, a failed node can be
repaired with the help of some specific nodes. In this work, a family of codes
based on graph theory, is constructed which achieves the fundamental bound on
file size for the particular heterogeneous DSS.


title: Measurement of the $B_{s}^{0} \rightarrow J/\psi \eta$ lifetime

abstract:
  Using a data set corresponding to an integrated luminosity of $3 fb^{-1}$,
collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies
of 7 and 8 TeV, the effective lifetime in the $B^0_s \rightarrow J/\psi \eta$
decay mode, $\tau_{\textrm{eff}}$, is measured to be $\tau_{\textrm{eff}} =
1.479 \pm 0.034~\textrm{(stat)} \pm 0.011 ~\textrm{(syst)}$ ps. Assuming $CP$
conservation, $\tau_{\textrm{eff}}$ corresponds to the lifetime of the light
$B_s^0$ mass eigenstate. This is the first measurement of the effective
lifetime in this decay mode.


title: On the exact decomposition threshold for even cycles

abstract:
  A graph $G$ has a $C_k$-decomposition if its edge set can be partitioned into
cycles of length $k$. We show that if $\delta(G)\geq 2|G|/3-1$, then $G$ has a
$C_4$-decomposition, and if $\delta(G)\geq |G|/2$, then $G$ has a
$C_{2k}$-decomposition, where $k\in \mathbb{N}$ and $k\geq 4$ (we assume $G$ is
large and satisfies necessary divisibility conditions). These minimum degree
bounds are best possible and provide exact versions of asymptotic results
obtained by Barber, K\"uhn, Lo and Osthus. In the process, we obtain asymptotic
versions of these results when $G$ is bipartite or satisfies certain expansion
properties.


title: Rigidity of groups of circle diffeomorphisms and Teichm\"uller spaces

abstract:
  We consider deformations of a group of circle diffeomorphisms with H\"older
continuous derivatives in the framework of quasiconformal Teichm\"uller theory
and show certain rigidity under conjugation by symmetric homeomorphisms of the
circle. As an application, we give a condition for such a diffeomorphism group
to be conjugate to a M\"obius group by a diffeomorphism of the same regularity.
The strategy is to find a fixed point of the group which acts isometrically on
the integrable Teichm\"uller space with the Weil-Petersson metric.


title:
A Multi-cut Formulation for Joint Segmentation and Tracking of Multiple
  Objects

abstract:
  Recently, Minimum Cost Multicut Formulations have been proposed and proven to
be successful in both motion trajectory segmentation and multi-target tracking
scenarios. Both tasks benefit from decomposing a graphical model into an
optimal number of connected components based on attractive and repulsive
pairwise terms. The two tasks are formulated on different levels of granularity
and, accordingly, leverage mostly local information for motion segmentation and
mostly high-level information for multi-target tracking. In this paper we argue
that point trajectories and their local relationships can contribute to the
high-level task of multi-target tracking and also argue that high-level cues
from object detection and tracking are helpful to solve motion segmentation. We
propose a joint graphical model for point trajectories and object detections
whose Multicuts are solutions to motion segmentation {\it and} multi-target
tracking problems at once. Results on the FBMS59 motion segmentation benchmark
as well as on pedestrian tracking sequences from the 2D MOT 2015 benchmark
demonstrate the promise of this joint approach.


title:
Hierarchical Manifold Clustering on Diffusion Maps for Connectomics (MIT
  18.S096 final project)

abstract:
  In this paper, we introduce a novel algorithm for segmentation of imperfect
boundary probability maps (BPM) in connectomics. Our algorithm can be a
considered as an extension of spectral clustering. Instead of clustering the
diffusion maps with traditional clustering algorithms, we learn the manifold
and compute an estimate of the minimum normalized cut. We proceed by divide and
conquer. We also introduce a novel criterion for determining if further splits
are necessary in a component based on it's topological properties. Our
algorithm complements the currently popular agglomeration approaches in
connectomics, which overlook the geometrical aspects of this segmentation
problem.


title: Continuous-time sparse domination

abstract:
  We develop the self similarity argument known as sparse domination in an
abstract martingale setting, using a continuous time parameter. With this
method, we prove a sharp weighted L^p estimate for the maximal operator Y^* of
Y with respect to X. Here Y and X are uniformly integrable c\`adll\`ag Hilbert
space valued martingales and Y differentially subordinate to X via the square
bracket process. We also present a second, very simple proof of the special
case Y=X. In this generality, notably including processes with jumps, the
special case Y = X addresses a question raised in the late 70s by
Bonami--L\'epingle.


title:
Scattering coefficients and bound states for high-energy transparent
  $\delta-\delta^{\prime}$ interactions

abstract:
  We propose a model for energy-dependent $\delta-\delta^{\prime}$ interactions
which yields scattering coefficients exhibiting full transmission for
high-energy incident particles, also computing the bound solutions in
one-dimension nonrelativistic quantum mechanics.


title:
Casimir force between $\delta-\delta^{\prime}$ mirrors transparent at
  high frequencies

abstract:
  We investigate, in the context of a real massless scalar field in $1+1$
dimensions, models of partially reflecting mirrors simulated by Dirac
$\delta-\delta^{\prime}$ point interactions. In the literature, these models do
not exhibit full transparency at high frequencies. In order to provide a more
realistic feature for these models, we propose a modified
$\delta-\delta^{\prime}$ point interaction that enables full transparency in
the limit of high frequencies. Taking this modified $\delta-\delta^{\prime}$
model into account, we investigate the Casimir force, comparing our results
with those found in the literature.


title: Long-Term Photometry of IC 348 with the YETI Network

abstract:
  We present long-term photometric observations of the young open cluster IC
348 with a baseline time-scale of 2.4 yr. Our study was conducted with several
telescopes from the Young Exoplanet Transit Initiative (YETI) network in the
Bessel $R$ band to find periodic variability of young stars. We identified 87
stars in IC 348 to be periodically variable; 33 of them were unreported before.
Additionally, we detected 61 periodic non-members of which 41 are new
discoveries. Our wide field of view was the key to those numerous newly found
variable stars. The distribution of rotation periods in IC 348 has always been
of special interest. We investigate it further with our newly detected periods
but we cannot find a statistically significant bimodality. We also report the
detection of a close eclipsing binary in IC 348 composed of a low-mass stellar
component ($M \gtrsim 0.09\,\mathrm{M}_{\odot}$) and a K0 pre-main sequence
star ($M \approx 2.7\,\mathrm{M}_{\odot}$). Furthermore, we discovered three
detached binaries among the background stars in our field of view and confirmed
the period of a fourth one.


title:
Classical Nonminimal Lagrangians and Kinematic Tests of Special
  Relativity

abstract:
  This article gives a brief summary on recently obtained classical lagrangians
for the nonminimal fermion sector of the Standard-Model Extension (SME). Such
lagrangians are adequate descriptions of classical particles that are subject
to a Lorentz-violating background field based on the SME. Explicitly,
lagrangians were obtained for the leading nonminimal contributions of the m, a,
c, e, and f coefficients. These results were then used to interpret classical,
kinematic tests of Special Relativity in the framework of the nonminimal SME.
This led to new constraints on certain nonminimal controlling coefficients.
Although the experiments were very sophisticated in the era when they were
carried out, their sensitivities for detecting Lorentz violation were still far
away from the Planck scale. Obtaining the novel constraints can be considered
as a proof-of-principle demonstrating the applicability of the classical
lagrangians computed.