title:
The Cosmic Large-Scale Structure in X-rays (CLASSIX) Cluster Survey I:
  Probing galaxy cluster magnetic fields with line of sight rotation measures

abstract:
  To search for a signature of an intracluster magnetic field, we compare
measurements of Faraday rotation of polarised extragalactic radio sources in
the line of sight of galaxy clusters with those outside. We correlated a
catalogue of 1383 rotation measures (RM) of extragalactic polarised radio
sources with X-ray luminous galaxy clusters from the CLASSIX survey (combining
REFLEX II and NORAS II). We compared the RM in the line of sight of clusters
within their projected radii of r_500 with those outside and found a
significant excess of the dispersion of the RM in the cluster regions. Since
the observed RM is the result of Faraday rotation in several presumably
uncorrelated magnetised cells of the intracluster medium, the observations
correspond to quantities averaged over several magnetic field directions and
strengths. Therefore the interesting quantity is the standard deviation of the
RM for an ensemble of clusters. We found a standard deviation of the RM inside
r_500 of about 120 +- 21 rad m^-2. This compares to about 56 +- 8 rad m^-2
outside. We show that the most X-ray luminous and thus most massive clusters
contribute most to the observed excess RM. Modelling the electron density
distribution in the intracluster medium with a self-similar model, we found
that the dispersion of the RM increases with the column density, and we deduce
a magnetic field value of about 2 - 6 (l/10kpc)^-1/2 microG assuming a constant
magnetic field strength, where l is the size of the coherently magnetised
intracluster medium cells. This magnetic field energy density amounts to a few
percent of the average thermal energy density in clusters. When we assumed the
magnetic energy density to be a constant fraction of the thermal energy
density, we deduced a slightly lower value for this fraction of 3 - 10
(l/10kpc)^-1/2 per mille.


title: Extremes of multidimensional stationary Gaussian random fields

abstract:
  Let $\{X(\mathbf{t}):\mathbf{t}=(t_1, t_2, \ldots, t_d)\in[0,\infty)^d\}$ be
a centered stationary Gaussian field with almost surely continuous sample
paths, unit variance and correlation function $r$ satisfying conditions
$r(\mathbf{t})<1$ for every $\mathbf{t}\neq \mathbf{0}$ and
$r(\mathbf{t})=1-\sum_{i=1}^d |t_i|^{\alpha_i} + o(\sum_{i=1}^d
|t_i|^{\alpha_i})$, as $\mathbf{t}\to\mathbf{0}$, with constants $\alpha_1,
\alpha_2, \ldots, \alpha_d \in(0,2]$. The main result of this contribution is
the description of the asymptotic behaviour of $P(\sup\{X(\mathbf{t}):
\mathbf{t}\in\mathcal{J}^{\mathbf{x}}_{\mathbf{m}} \}\leqslant u)$, as
$u\to\infty$, for some Jordan-measurable sets
$\mathcal{J}^{\mathbf{x}}_{\mathbf{m}}$ of volume proportional to
$P(\sup\{X(\mathbf{t}):\mathbf{t}\in[0,1]^d\}>u)^{-1}(1+o(1))$.


title: Linear convergence of the Randomized Sparse Kaczmarz Method

abstract:
  The randomized version of the Kaczmarz method for the solution of linear
systems is known to converge linearly in expectation. In this work we extend
this result and show that the recently proposed Randomized Sparse Kaczmarz
method for recovery of sparse solutions, as well as many variants, also
converges linearly in expectation. The result is achieved in the framework of
split feasibility problems and their solution by randomized Bregman projections
with respect to strongly convex functions. To obtain the expected convergence
rates we prove extensions of error bounds for projections. The convergence
result is shown to hold in more general settings involving smooth convex
functions, piecewise linear-quadratic functions and also the regularized
nuclear norm, which is used in the area of low rank matrix problems. Numerical
experiments indicate that the Randomized Sparse Kaczmarz method provides
advantages over both the non-randomized and the non-sparse Kaczmarz methods for
the solution of over- and under-determined linear systems.


title: On Butterfly effect in Higher Derivative Gravities

abstract:
  We study butterfly effect in $D$-dimensional gravitational theories
containing terms quadratic in Ricci scalar and Ricci tensor. One observes that
due to higher order derivatives in the corresponding equations of motion there
are two butterfly velocities. The velocities are determined by the dimension of
operators whose sources are provided by the metric. The three dimensional TMG
model is also studied where we get two butterfly velocities at generic point of
the moduli space of parameters. At critical point two velocities coincide.


title: Personalizing a Dialogue System with Transfer Reinforcement Learning

abstract:
  It is difficult to train a personalized task-oriented dialogue system because
the data collected from each individual is often insufficient. Personalized
dialogue systems trained on a small dataset can overfit and make it difficult
to adapt to different user needs. One way to solve this problem is to consider
a collection of multiple users' data as a source domain and an individual
user's data as a target domain, and to perform a transfer learning from the
source to the target domain. By following this idea, we propose
"PETAL"(PErsonalized Task-oriented diALogue), a transfer-learning framework
based on POMDP to learn a personalized dialogue system. The system first learns
common dialogue knowledge from the source domain and then adapts this knowledge
to the target user. This framework can avoid the negative transfer problem by
considering differences between source and target users. The policy in the
personalized POMDP can learn to choose different actions appropriately for
different users. Experimental results on a real-world coffee-shopping data and
simulation data show that our personalized dialogue system can choose different
optimal actions for different users, and thus effectively improve the dialogue
quality under the personalized setting.


title:
Noether identities in gravity theories with nondynamical backgrounds and
  explicit spacetime symmetry breaking

abstract:
  Gravitational effective field theories with nondynamical backgrounds
explicitly break diffeomorphism and local Lorentz invariance. At the same time,
to maintain observer independence the action describing these theories is
required to be mathematically invariant under general coordinate
transformations and changes of local Lorentz bases. These opposing effects of
having broken spacetime symmetries but invariance under mathematical observer
transformations can result in theoretical inconsistency unless certain
conditions hold. The consistency constraints that must hold originate from
Noether identities associated with the mathematical observer invariances in the
action. These identities are examined in detail and are used to investigate
gravity theories with nondynamical backgrounds, including when a St\"uckelberg
approach is used. Specific examples include gravity theories with fixed scalar
or tensor backgrounds, Einstein-Maxwell theory with a fixed external current,
and massive gravity.


title:
Cosmological solutions with gravitational particle production and
  non-zero curvature

abstract:
  In a homogeneous and isotropic universe with non-zero spatial curvature we
consider the effects of gravitational particle production in the dynamics of
the universe. We show that the dynamics of the universe in such a background is
characterized by a single nonlinear differential equation which is
significantly dependent on the rate of particle creation and whose solutions
can be dominated by the curvature effects at early times. For different
particle creation rates we apply the singularity test in order to find the
analytic solutions of the background dynamics. We describe the behavior of the
cosmological solutions for both open and closed universes. We also show how the
effects of curvature can be produced by the presence of a second perfect fluid
with an appropriate equation of state. By combining that results with the
analysis of the critical points we find that our consideration can be related
with the pre-inflationary era. Specifically we find that for negative spatial
curvature small changes of the Milne spacetime leads to a de Sitter universe.


title:
Speedup of lexicographic optimization by superiorization and its
  applications to cancer radiotherapy treatment

abstract:
  Multicriteria optimization problems occur in many real life applications, for
example in cancer radiotherapy treatment and in particular in intensity
modulated radiation therapy (IMRT). In this work we focus on optimization
problems with multiple objectives that are ranked according to their
importance. We solve these problems numerically by combining lexicographic
optimization with our recently proposed level set scheme, which yields a
sequence of auxiliary convex feasibility problems; solved here via projection
methods. The projection enables us to combine the newly introduced
superiorization methodology with multicriteria optimization methods to speed up
computation while guaranteeing convergence of the optimization. We demonstrate
our scheme with a simple 2D academic example (used in the literature) and also
present results from calculations on four real head neck cases in IMRT
(Radiation Oncology of the Ludwig-Maximilians University, Munich, Germany) for
two different choices of superiorization parameter sets suited to yield fast
convergence for each case individually or robust behavior for all four cases.


title: A Novel Collaborative Cognitive Dynamic Network Architecture

abstract:
  Increasing mobile data demands in current cellular networks and proliferation
of advanced handheld devices have given rise to a new generation of dynamic
network architectures (DNAs). In a DNA, users share their connectivities and
act as access points providing Internet connections for others without
additional network infrastructure cost. A large number of users and their
dynamic connections make DNA highly adaptive to variations in the network and
suitable for low cost ubiquitous Internet connectivity. In this article, we
propose a novel collaborative cognitive dynamic network architecture (CDNA)
which incorporates cognitive capabilities to exploit underutilized spectrum in
a more flexible and intelligent way. The design principles of CDNA are
perfectly aligned to the functionality requirements of future 5G wireless
networks such as energy and spectrum efficiency, scalability, dynamic
reconfigurability, support for multi-hop communications, infrastructure
sharing, and multi-operator cooperation. A case study with a new resource
allocation problem enabled by CDNA is conducted using matching theory with
pricing to illustrate the potential benefits of CDNA for users and operators,
tackle user associations for data and spectrum trading with low complexity, and
enable self-organizing capabilities. Finally, possible challenges and future
research directions are given.


title: Inequalities for two systems of subspaces with prescribed intersections

abstract:
  Let $W$ denote a linear space over a fixed field ${\mathbb F}$. We define the
notions of weak $ISP$-system and weak $(u,v)$-system $\cal S=\{(U_i,V_i):~
1\leq i\leq m\}$ of subspaces of $W$. We give upper bounds for the size of weak
$ISP$-systems and weak $(u,v)$-systems.


title: Taming intermittent plasticity at small scales

abstract:
  The extreme miniaturization in modern technology calls for deeper insights
into the non-conventional, fluctuation dominated mechanics of materials at
micro- to nano-scales. Both experiments and simulations show that sub-micron
face-centered-cubic (FCC) crystals exhibit high yield strength, which is,
however, compromised by intermittent, power law distributed strain
fluctuations, typical of wild plasticity. At macro-scales, the same bulk
materials show mild plasticity characterized by bounded, uncorrelated
fluctuations. Both anomalous strength and intermittency appear therefore as
size effects. While the former is highly desirable, the latter is detrimental
because stochastic dislocation avalanches interfere with forming processes and
endanger structural stability. In this paper we show that defectiveness, which
is used in classical metallurgy to harden materials, can be used at sub-micron
scales to suppress intermittent fluctuations. We quantify the coexistence of
wild and mild fluctuations in compressed Al alloys micro-pillars, demonstrate
that the statistical nature of fluctuations is determined by sample size, and
propose quantitative strategies allowing one to temper plastic intermittency by
artificially tailored disorder. Our experimental results are rationalized using
a theoretical framework which quantifies the competition between external (size
related) and internal (disorder related) length scales.


title: Energy Identity for Stationary Yang Mills

abstract:
  Given a principal bundle $P\to M$ over a Riemannian manifold with compact
structure group $G$, let us consider a stationary Yang-Mills connection $A$
with energy $\int_M |F_A|^2\le \Lambda$. If we consider a sequence of such
connections $A_i$, then it is understood that up to subsequence we can converge
$A_i\to A$ to a singular limit connection such that the energy measures
converge $|F_{A_i}|^2 dv_g\to |F_A|^2dv_g +\nu$, where $\nu=e(x)d\lambda^{n-4}$
is the $n-4$ rectifiable defect measure. Our main result is to show, without
additional assumptions, that for $n-4$ a.e. point the energy density $e(x)$ may
be computed explicitly as the sum of the bubble energies arising from blow ups
at $x$. Each of these bubbles may be realized as a Yang Mills connection over
$S^4$ itself.
  Our second main theorem is to show this hessian bound holds automatically.
Precisely, given a connection $A$ as above we have the apriori estimate $\int_M
|\nabla^2 F_A| < C(\Lambda,\dim G,M)$ for the curvature. It is important to
note this result is proved in tandem with the energy quantization, and not
before it. Indeed, we will in fact prove an effective version of the energy
identity, and it is this effective version which will lead to both the $L^1$
hessian bound and the classical energy quantization results. In the course of
the proof we will provide a quantitative version of the bubble tree
decomposition which hold in all dimensions with effective estimates for a fixed
stationary connections. To produce to strongest estimates in the paper we
introduce an $\epsilon$-gauge condition, which generalizes the usual Coulomb
gauge and which will exist, with effective control, even over singular regions.
On these $\epsilon$-gauges we will provide a new superconvexity estimate which
will be a key tool in analyzing higher dimensional annular regions.


title: The Medium Size Telescopes of the Cherenkov Telescope Array

abstract:
  The Cherenkov Telescope Array (CTA) is the planned next-generation instrument
for ground-based gamma-ray astronomy, covering a photon energy range of ~20 GeV
to above 100 TeV. CTA will consist of the order of 100 telescopes of three
sizes, installed at two sites in the Northern and Southern Hemisphere. This
contribution deals with the 12 meter Medium Size Telescopes (MST) having a
single mirror (modified Davies-Cotton, DC) design. In the baseline design of
the CTA arrays, 25 MSTs in the South and 15 MSTs in the North provide the
necessary sensitivity for CTA in the core energy range of 100 GeV to 10 TeV.
DC-MSTs will be equipped with photomultiplier (PMT)-based cameras. Two options
are available for these focal plane instruments, that will be provided by the
FlashCam and the NectarCAM sub-consortia. In this contribution, a short
introduction to the projects and their status is given.


title: Prediction Law of fractional Brownian Motion

abstract:
  We calculate the regular conditional future law of the fractional Brownian
motion with index $H\in(0,1)$ conditioned on its past. We show that the
conditional law is continuous with respect to the conditioning path. We
investigate the path properties of the conditional process and the asymptotic
behavior of the conditional covariance.


title: Quantum groups, Verma modules and $q$-oscillators: General linear case

abstract:
  The Verma modules over the quantum groups $\mathrm U_q(\mathfrak{gl}_{l +
1})$ for arbitrary values of $l$ are analysed. The explicit expressions for the
action of the generators on the elements of the natural basis are obtained. The
corresponding representations of the quantum loop algebras $\mathrm
U_q(\mathcal L(\mathfrak{sl}_{l + 1}))$ are constructed via Jimbo's
homomorphism. This allows us to find certain representations of the positive
Borel subalgebras of $\mathrm U_q(\mathcal L(\mathfrak{sl}_{l + 1}))$ as
degenerations of the shifted representations. The latter are the
representations used in the construction of the so-called $Q$-operators in the
theory of quantum integrable systems. The interpretation of the corresponding
simple quotient modules in terms of representations of the $q$-deformed
oscillator algebra is given.


title:
Content Based Image Retrieval (CBIR) in Remote Clinical Diagnosis and
  Healthcare

abstract:
  Content-Based Image Retrieval (CBIR) locates, retrieves and displays images
alike to one given as a query, using a set of features. It demands accessible
data in medical archives and from medical equipment, to infer meaning after
some processing. A problem similar in some sense to the target image can aid
clinicians. CBIR complements text-based retrieval and improves evidence-based
diagnosis, administration, teaching, and research in healthcare. It facilitates
visual/automatic diagnosis and decision-making in real-time remote
consultation/screening, store-and-forward tests, home care assistance and
overall patient surveillance. Metrics help comparing visual data and improve
diagnostic. Specially designed architectures can benefit from the application
scenario. CBIR use calls for file storage standardization, querying procedures,
efficient image transmission, realistic databases, global availability, access
simplicity, and Internet-based structures. This chapter recommends important
and complex aspects required to handle visual content in healthcare.


title:
Linear Quadratic Optimal Control Problems for Mean-Field Backward
  Stochastic Differential Equations

abstract:
  This paper is concerned with linear quadratic optimal control problems for
mean-field backward stochastic differential equations (MF-BSDEs, for short)
with deterministic coefficients. The optimality system, which is a linear
mean-field forward-backward stochastic differential equation with constraint,
is obtained by a variational method. By decoupling the optimality system, two
coupled Riccati equations and an MF-BSDE are derived. It turns out that the
coupled two Riccati equations are uniquely solvable. Then a complete and
explicit representation is obtained for the optimal control.


title: Extending Chiral Perturbation Theory with an Isosinglet Scalar

abstract:
  We augment the chiral Lagrangian by an isosinglet scalar and compute the
one-loop radiative corrections to the pion mass and decay constant, as well as
the scalar mass. The calculations are carried out for different patterns of
chiral symmetry breaking of immediate relevance for phenomenology and lattice
investigations. By construction our results encompass several interesting
limits, ranging from the dilaton to the linear sigma model.


title: Dual virtual element method for discrete fractures networks

abstract:
  Discrete fracture networks is a key ingredient in the simulation of physical
processes which involve fluid flow in the underground, when the surrounding
rock matrix is considered impervious. In this paper we present two different
models to compute the pressure field and Darcy velocity in the system. The
first allows a normal flow out of a fracture at the intersections, while the
second grants also a tangential flow along the intersections. For the numerical
discretization, we use the mixed virtual finite element method as it is known
to handle grid elements of, almost, any arbitrary shape. The flexibility of the
discretization allows us to loosen the requirements on grid construction, and
thus significantly simplify the flow discretization compared to traditional
discrete fracture network models. A coarsening algorithm, from the algebraic
multigrid literature, is also considered to further speed up the computation.
The performance of the method is validated by numerical experiments.


title: A General Framework for Content-enhanced Network Representation Learning

abstract:
  This paper investigates the problem of network embedding, which aims at
learning low-dimensional vector representation of nodes in networks. Most
existing network embedding methods rely solely on the network structure, i.e.,
the linkage relationships between nodes, but ignore the rich content
information associated with it, which is common in real world networks and
beneficial to describing the characteristics of a node. In this paper, we
propose content-enhanced network embedding (CENE), which is capable of jointly
leveraging the network structure and the content information. Our approach
integrates text modeling and structure modeling in a general framework by
treating the content information as a special kind of node. Experiments on
several real world net- works with application to node classification show that
our models outperform all existing network embedding methods, demonstrating the
merits of content information and joint learning.


title:
The stratorotational instability of Taylor-Couette flows of moderate
  Reynolds numbers

abstract:
  In view of new experimental data the instability against adiabatic
nonaxisymmetric perturbations of a Taylor-Couette flow with an axial density
stratification is considered in dependence of the Reynolds number Re of
rotation and the Brunt-V\"ais\"al\"a number Rn of the stratification. The flows
at and beyond the Rayleigh limit become unstable between a lower and an upper
Reynolds number (for fixed Rn). The rotation can thus be too slow or too fast
for the stratorotational instability. The upper Reynolds number above which the
instability decays, has its maximum value for the potential flow (driven by
cylinders rotating according to the Rayleigh limit) and decreases strongly for
flatter rotation profiles finally leaving only isolated islands of instability
in the (Rn/Re) map. The maximal possible rotation ratio $\mu_{\rm max}$ only
slightly exceeds the shear value of the quasi-uniform flow with
$U_\phi\simeq$const.
  Along and between the lines of neutral stability the wave numbers of the
instability patterns for all rotation laws beyond the Rayleigh limit are mainly
determined by the Froude number Fr which is defined by the ratio between Re and
Rn. The cells are highly prolate for Fr>1 so that measurements for too high
Reynolds numbers become difficult for axially bounded containers. The
instability patterns migrate azimuthally slightly faster than the outer
cylinder rotates.


title:
Fundamental difference between superblockers and superspreaders in
  networks

abstract:
  Two very important problems regarding spreading phenomena in complex
topologies are the optimal selection of node sets either to minimize or
maximize the extent of outbreaks. Both problems are nontrivial when a small
fraction of the nodes in the network can be used to achieve the desired goal.
The minimization problem is equivalent to a structural optimization. The
"superblockers", i.e., the nodes that should be removed from the network to
minimize the size of outbreaks, are those nodes that make connected components
as small as possible. "Superspreaders" are instead the nodes such that, if
chosen as initiators, they maximize the average size of outbreaks. The identity
of superspreaders is expected to depend not just on the topology, but also on
the specific dynamics considered. Recently, it has been conjectured that the
two optimization problems might be equivalent, in the sense that superblockers
act also as superspreaders. In spite of its potential groundbreaking
importance, no empirical study has been performed to validate this conjecture.
In this paper, we perform an extensive analysis over a large set of real-world
networks to test the similarity between sets of superblockers and of
superspreaders. We show that the two optimization problems are not equivalent:
superblockers do not act as optimal spreaders.


title:
Achievable Rate and Energy Efficiency of Hybrid and Digital Beamforming
  Receivers with Low Resolution ADC

abstract:
  For 5G it will be important to leverage the available millimeter wave
spectrum. To achieve an approximately omni- directional coverage with a similar
effective antenna aperture compared to state of the art cellular systems, an
antenna array is required at both the mobile and basestation. Due to the large
bandwidth and inefficient amplifiers available in CMOS for mmWave, the analog
front-end of the receiver with a large number of antennas becomes especially
power hungry. Two main solutions exist to reduce the power consumption: Hybrid
BeamForming (HBF) and Digital BeamForming (DBF) with low resolution ADC. Hybrid
beamforming can also be combined with low resolution ADCs. This paper compares
the spectral and energy efficiency based on the chosen RF-frontend
configuration. A channel with multipath propagation is used. In contrast to
previous publication, we take the spatial correlation of the quantization noise
into account. We show that the low resolution ADC are robust to small Automatic
Gain Control (AGC) imperfections. We showed that in the low SNR regime the
performance of DBF even with 1-2 bit resolution outperforms HBF. If we consider
the relationship of spectral and energy efficiency then DBF with 3-5 bits
resolution achieves the best ratio of spectral efficiency per power consumption
of the RF receiver frontend over a very wide SNR region. The power consumption
model is based on components reported in literature.


title:
Determining the value of the fine-structure constant from a current
  balance: getting acquainted with some upcoming changes to the SI

abstract:
  The revised International System of Units (SI), expected to be approved late
in 2018, has implications for physics pedagogy; the ampere definition which
dates from 1948 will be replaced by a definition that fixes the numerical value
of the elementary charge, e, in coulombs. The kilogram definition which dates
from 1889 will be replaced by a definition that fixes the numerical value of
the Planck constant, h, in joule seconds. Existing SI equations are completely
unaffected. However, there will be a largely-negligible, but nevertheless
necessary, change to published numerical factors relating SI electrical units
to their corresponding units in the Gaussian and other CGS systems of units.
The implications of the revised SI for electrical metrology are neatly
illustrated by considering the interpretation of results obtained from a
current balance in the present SI and in the revised SI.


title:
Structural origins of the boson peak in metals: From high-entropy alloys
  to metallic glasses

abstract:
  The boson peak appears in all amorphous solids and is an excess of
vibrational states at low frequencies compared to the phonon spectrum of the
corresponding crystal. Until recently, the consensus was that it originated
from "defects" in the glass. The nature of these defects is still under
discussion, but the picture of regions with locally disturbed short-range order
and/or decreased elastic constants has gained some traction. Recently, a
different theory was proposed: The boson peak was attributed to the first van
Hove singularity of crystal lattices which is only smeared out by the disorder.
This new viewpoint assumes that the van Hove singularity is simply shifted by
the decreased density of the amorphous state and is therefore not a
glass-specific anomaly. In order to resolve this issue, we use computer models
of a four-component alloy, alternatively with chemical disorder (high-entropy
alloy), structural disorder, and reduced density. Comparison to a reference
glass of the same composition reveals that the boson peak consists of
additional vibrational modes which can be induced solely by structural
disorder. While chemical disorder introduces fluctuations of the elastic
constants, we find that those do not lead to sufficient local softening to
induce these modes. A boson peak due to a reduction of density could be
excluded for the present metallic system.


title:
Propinquity of current and vortex structures: effects on collisionless
  plasma heating

abstract:
  Intermittency of heating in weakly collisional plasma turbulence is an active
subject of research, with significant potential impact on understanding of the
solar wind, solar corona and astrophysical plasmas. Recent studies suggest a
role of vorticity in plasma heating. In magnetohydrodynamics small scale
vorticity is generated near current sheets and this effect persists in kinetic
plasma, as demonstrated here with hybrid and fully kinetic Particle-In-Cell
(PIC) simulations. Furthermore, vorticity enhances local kinetic effects, with
a generalized resonance condition selecting sign-dependent enhancements or
reductions of proton heating and thermal anisotropy. In such plasmas heating is
correlated with vorticity and current density, but more strongly with
vorticity. These results help explain several prior results that find kinetic
effects and energization near to, but not centered on, current sheets.
Evidently intermittency in kinetic plasma involves multiple physical
quantities, and the associated coherent structures and nonthermal effects are
closely related.


title:
Building Medium Size Telescope Structures for the Cherenkov Telescope
  Array

abstract:
  The Cherenkov Telescope Array (CTA) is the future instrument in ground-based
gamma-ray astronomy in the energy range from 20 GeV to 300 TeV. Its sensitivity
will surpass that of current generation experiments by a factor $\sim$10,
facilitated by telescopes of three sizes. The performance in the core energy
regime will be dominated by Medium Size Telescopes (MST) with a reflector of 12
m diameter. A full-size mechanical prototype of the telescope structure has
been constructed in Berlin. The performance of the prototype is being evaluated
and optimisations, among others, facilitating the assembly procedure and mass
production possibilities are being implemented. We present the current status
of the developments from prototyping towards pre-production telescopes, which
will be deployed at the final site.


title: Symmetric Wilson Loops beyond leading order

abstract:
  We study the circular Wilson loop in the symmetric representation of U(N) in
$\mathcal{N} = 4$ super-Yang-Mills (SYM). In the large N limit, we computed the
exponentially-suppressed corrections for strong coupling, which suggests
non-perturbative physics in the dual holographic theory. We also computed the
next-to-leading order term in 1/N, and the result matches with the exact result
from the k-fundamental representation.


title: Deep Pyramidal Residual Networks

abstract:
  Deep convolutional neural networks (DCNNs) have shown remarkable performance
in image classification tasks in recent years. Generally, deep neural network
architectures are stacks consisting of a large number of convolutional layers,
and they perform downsampling along the spatial dimension via pooling to reduce
memory usage. Concurrently, the feature map dimension (i.e., the number of
channels) is sharply increased at downsampling locations, which is essential to
ensure effective performance because it increases the diversity of high-level
attributes. This also applies to residual networks and is very closely related
to their performance. In this research, instead of sharply increasing the
feature map dimension at units that perform downsampling, we gradually increase
the feature map dimension at all units to involve as many locations as
possible. This design, which is discussed in depth together with our new
insights, has proven to be an effective means of improving generalization
ability. Furthermore, we propose a novel residual unit capable of further
improving the classification accuracy with our new network architecture.
Experiments on benchmark CIFAR-10, CIFAR-100, and ImageNet datasets have shown
that our network architecture has superior generalization ability compared to
the original residual networks. Code is available at
https://github.com/jhkim89/PyramidNet}


title:
Building an Inclusive AAS - The Critical Role of Diversity and Inclusion
  Training for AAS Council and Astronomy Leadership

abstract:
  Diversity, equity and inclusion are the science leadership issues of our
time. As our nation and the field of astronomy grow more diverse, we find
ourselves in a position of enormous potential and opportunity: a multitude of
studies show how groups of diverse individuals with differing viewpoints
outperform homogenous groups to find solutions that are more innovative,
creative, and responsive to complex problems, and promote higher-order thinking
amongst the group. Research specifically into publications also shows that
diverse author groups publish in higher quality journals and receive higher
citation rates. As we welcome more diverse individuals into astronomy, we
therefore find ourselves in a position of potential never before seen in the
history of science, with the best minds and most diverse perspectives our field
has ever seen. Despite this enormous growing potential, and the proven power of
diversity, the demographics of our field are not keeping pace with the changing
demographics of the nation, and astronomers of colour, women, LGBT individuals,
people with disabilities, and those with more than one of these identities
still face "chilly" or "hostile" work environments in the sciences. If we are
to fully support all astronomers and students in reaching their full scientific
potential, we must recognize that most of us tend to overestimate our ability
to support our minoritized students and colleagues, that our formal education
system fails to prepare us for working in a multicultural environment, and that
most of us need some kind of training to help us know what we don't know and
fill those gaps in our education. To that end, diversity and inclusion training
for AAS council and leadership, heads of astronomy departments, and faculty
search committees should be a basic requirement throughout our field.

categories: astro-ph.IM astro-ph.CO astro-ph.EP astro-ph.GA astro-ph.HE astro-ph.SR physics.soc-ph


title:
Weight decompositions of Thom spaces of vector bundles in rational
  homotopy theory

abstract:
  Motivated by the theory of representability classes by submanifolds, we study
the rational homotopy theory of Thom spaces of vector bundles. We first give a
Thom isomorphism at the level of rational homotopy, extending work of
Felix-Oprea-Tanr\'e by removing hypothesis of nilpotency of the base and
orientability of the bundle. Then, we use the theory of weight decompositions
in rational homotopy to give a criterion of representability of classes by
submanifolds, generalising results of Papadima. Along the way, we study issues
of formality and give formulas for Massey products of Thom spaces. Lastly, we
link the theory of weight decompositions with mixed Hodge theory and apply our
results to motivic Thom spaces.


title:
Phase transitions and optimal algorithms in high-dimensional Gaussian
  mixture clustering

abstract:
  We consider the problem of Gaussian mixture clustering in the
high-dimensional limit where the data consists of $m$ points in $n$ dimensions,
$n,m \rightarrow \infty$ and $\alpha = m/n$ stays finite. Using exact but
non-rigorous methods from statistical physics, we determine the critical value
of $\alpha$ and the distance between the clusters at which it becomes
information-theoretically possible to reconstruct the membership into clusters
better than chance. We also determine the accuracy achievable by the
Bayes-optimal estimation algorithm. In particular, we find that when the number
of clusters is sufficiently large, $r > 4 + 2 \sqrt{\alpha}$, there is a gap
between the threshold for information-theoretically optimal performance and the
threshold at which known algorithms succeed.


title: Analysis of Downlink and Uplink Decoupling in Dense Cellular Networks

abstract:
  Decoupling uplink (UL) and downlink (DL) is a new architectural paradigm
where DL and UL are not constrained to be associated to the same base station
(BS). Building upon this paradigm, the goal of the present paper is to provide
lower, albeit tight bounds for the ergodic UL capacity of a decoupled cellular
network. The analysis is performed for a scenario consisting of a macro BS and
a set of small cells (SCs) whose positions are selected randomly according to a
Poisson point process of a given spatial density. Based on this analysis simple
bounds in closed form expressions are defined. The devised bounds are employed
to compare the performance of the decoupled case versus a set of benchmark
cases, namely the coupled case, and the situations of having either a single
macro BS or only SCs. This comparison provides valuable insights regarding the
behavior and performance of such networks, providing simpler expressions for
the ergodic UL capacity as a function of the distances to the macro BS and the
density of SCs. These expressions constitute a simple guide to the minimum
degree of densification that guarantees the Quality of Service (QoS) objectives
of the network, thus, providing a valuable tool to the network operator of
significant practical and commercial value.


title: Generative Adversarial Nets from a Density Ratio Estimation Perspective

abstract:
  Generative adversarial networks (GANs) are successful deep generative models.
GANs are based on a two-player minimax game. However, the objective function
derived in the original motivation is changed to obtain stronger gradients when
learning the generator. We propose a novel algorithm that repeats the density
ratio estimation and f-divergence minimization. Our algorithm offers a new
perspective toward the understanding of GANs and is able to make use of
multiple viewpoints obtained in the research of density ratio estimation, e.g.
what divergence is stable and relative density ratio is useful.


title:
Systematic effects in the low-energy behavior of the current SAID
  solution for the pion-nucleon system

abstract:
  We investigate the description of the pion-nucleon experimental data at low
energy (i.e., below pion laboratory kinetic energy of $100$ MeV) on the basis
of the current SAID solution (WI08). We demonstrate that, in a self-consistent
analysis scheme, the scale factors of the fits based on the Arndt-Roper formula
come out independent of the beam energy and `cluster' around the expectation
value of $1$. We report systematic effects in the low-energy behavior of the
WI08 solution. These effects indicate that at least one of the three following
assumptions, underlying the WI08 analysis, does \emph{not} hold, namely that:
a) the bulk of the data is reliable, b) the electromagnetic effects are
correctly accounted for, and c) the isospin invariance in the strong
interactions of the $\pi N$ system is valid.


title: Towards an Ontology-Driven Blockchain Design for Supply Chain Provenance

abstract:
  An interesting research problem in our age of Big Data is that of determining
provenance. Granular evaluation of provenance of physical goods--e.g. tracking
ingredients of a pharmaceutical or demonstrating authenticity of luxury
goods--has often not been possible with today's items that are produced and
transported in complex, inter-organizational, often internationally-spanning
supply chains. Recent adoption of Internet of Things and Blockchain
technologies give promise at better supply chain provenance. We are
particularly interested in the blockchain as many favoured use cases of
blockchain are for provenance tracking. We are also interested in applying
ontologies as there has been some work done on knowledge provenance,
traceability, and food provenance using ontologies. In this paper, we make a
case for why ontologies can contribute to blockchain design. To support this
case, we analyze a traceability ontology and translate some of its
representations to smart contracts that execute a provenance trace and enforce
traceability constraints on the Ethereum blockchain platform.


title: EM-Based Mixture Models Applied to Video Event Detection

abstract:
  Surveillance system (SS) development requires hi-tech support to prevail over
the shortcomings related to the massive quantity of visual information from
SSs. Anything but reduced human monitoring became impossible by means of its
physical and economic implications, and an advance towards an automated
surveillance becomes the only way out. When it comes to a computer vision
system, automatic video event comprehension is a challenging task due to motion
clutter, event understanding under complex scenes, multilevel semantic event
inference, contextualization of events and views obtained from multiple
cameras, unevenness of motion scales, shape changes, occlusions and object
interactions among lots of other impairments. In recent years, state-of-the-art
models for video event classification and recognition include modeling events
to discern context, detecting incidents with only one camera, low-level feature
extraction and description, high-level semantic event classification, and
recognition. Even so, it is still very burdensome to recuperate or label a
specific video part relying solely on its content. Principal component analysis
(PCA) has been widely known and used, but when combined with other techniques
such as the expectation-maximization (EM) algorithm its computation becomes
more efficient. This chapter introduces advances associated with the concept of
Probabilistic PCA (PPCA) analysis of video event and it also aims at looking
closely to ways and metrics to evaluate these less intensive EM implementations
of PCA and KPCA.


title:
The role of meson exchange currents in charged current
  (anti)neutrino-nucleus scattering

abstract:
  We present our recent progress in the description of neutrino-nucleus
interaction in the GeV region, of interest for ongoing and future oscillation
experiments. In particular, we discuss the weak excitation of
two-particle-two-hole states induced by meson exchange currents in a fully
relativistic framework. We compare the results of our model with recent
measurements of neutrino scattering cross sections, showing the crucial role
played by two-nucleon knockout in the interpretation of the data.


title:
Vector boson production in proton-lead and lead-lead collisions at the
  LHC and its impact on nCTEQ15 PDFs

abstract:
  We provide a comprehensive comparison of W/Z vector boson production data in
proton-lead and lead-lead collisions at the LHC with predictions obtained using
the nCTEQ15 PDFs. We identify the measurements which have the largest potential
impact on the PDFs, and estimate the effect of including these data using a
Monte Carlo reweighting method. We find this data set can provide information
about both the nuclear corrections and the heavy flavor (strange) PDF
components. As the proton flavor determination is dependent on nuclear
corrections (from heavy target DIS, for example), this information can also
help improve the proton PDFs.


title:
Parametric frequency mixing in the magneto-elastically driven
  FMR-oscillator

abstract:
  We demonstrate the nonlinear frequency conversion of ferromagnetic resonance
(FMR) frequency by optically excited elastic waves in a thin metallic film on
dielectric substrates. Time-resolved probing of the magnetization directly
witnesses magneto-elastically driven second harmonic generation, sum- and
difference frequency mixing from two distinct frequencies, as well as
parametric downconversion of each individual drive frequency. Starting from the
Landau-Lifshitz-Gilbert equations, we derive an analytical equation of an
elastically driven nonlinear parametric oscillator and show that frequency
mixing is dominated by the parametric modulation of FMR frequency.


title:
The Role of Interaction in the Pairing of Two Spin-orbit Coupled
  Fermions

abstract:
  We investigate the role of a repulsive s-wave interaction in the two-body
problem in the presence of spin orbit couplings, motivated by current interests
in exploring exotic superfluid phases in spin-orbit coupled Fermi gases. For
weak spin orbit coupling where the density of states is not significantly
altered, we analytically show that the high-energy states become more important
in determining the binding energy when the interaction strength decreases.
Consequently, tuning the interaction gives rise to a rich ground state
behavior, including a zigzag of the ground state momentum or inducing
transitions among the meta-stable states. By exactly solving the two-body
problem for a spin-orbit coupled Fermi mixture, we demonstrate that our
analysis can also apply to the case when the density of states is significantly
modified by the spin-orbit coupling. Our findings pave the way for
understanding and controlling the paring of fermions in the presence of spin
orbit couplings.


title:
Reply to the Comment on "Theoretical study of thorium monoxide for the
  electron electric dipole moment search: Electronic properties of
  $H^3\Delta_1$ in ThO"

abstract:
  We reply to the comment [M. Denis, T. Fleig, arXiv:1605.03091v1 (2016)] on
paper [L.V. Skripnikov and A.V. Titov, J. Chem. Phys. 142, 024301 (2015)].


title:
Engineering Quantum Confinement in Semiconducting van der Waals
  Heterostructure

abstract:
  Spatial confinement and manipulation of charged carriers in semiconducting
nanostructures are essential for realizing quantum electronic devices.
Gate-defined nanostructures made of two-dimensional (2D) semiconducting
transition metal dichalcogenides (TMDCs) have the potential to add a unique
additional control of quantum degrees of freedom owing to valley-spin locking
of confined carriers near the band edges. However, due to prevailing
inhomogeneities in the conducting channels, it has been difficult to realize
quantum confinement in 2D TMDCs with well-controlled tunnel-coupling strength.
Here we demonstrate quantum transport in lateral gate-defined 2D electron
quantum dots formed in atomically thin TMDC heterostructures. Utilizing
micro-fabricated local contact gates, encapsulation in 2D dielectrics and light
illumination at low temperatures, we show that the quality of TMDC 2D electron
gases (2DEGs) can be improved, rendering them suitable for mesoscopic quantum
transport measurements. We observe quantized conductance in quantum point
contact (QPC) channels controlled by gate-tunable confinement. We also
demonstrate single electron transport in TMDC quantum dots (QD) with tunable
tunnel-coupling. Our observation holds promise for the quantum manipulation of
spin and valley degrees of freedom in engineered TMDC nanostructures, enabling
versatile 2D quantum electronic devices.


title:
Gluing and grazing bifurcations in periodically forced 2-dimensional
  integrate-and-fire models

abstract:
  In this work we consider a general class of $2$-dimensional hybrid systems.
Assuming that the system possesses an attracting equilibrium point, we show
that, when periodically driven with a square-wave pulse, the system possesses a
periodic orbit which may undergo smooth and nonsmooth grazing bifurcations. We
perform a semi-rigorous study of the existence of periodic orbits for a
particular model consisting of a leaky integrate-and-fire model with a dynamic
threshold. We use the stroboscopic map, which in this context is a
$2$-dimensional piecewise-smooth discontinuous map. For some parameter values
we are able to show that the map is a quasi-contraction possessing a (locally)
unique maximin periodic orbit. We complement our analysis using advanced
numerical techniques to provide a complete portrait of the dynamics as
parameters are varied. We find that for some regions of the parameter space the
model undergoes a cascade of gluing bifurcations, while for others the model
shows multistability between orbits of different periods.


title: Multi-Message Broadcast in Dynamic Radio Networks

abstract:
  We continue the recent line of research studying information dissemination
problems in adversarial dynamic radio networks. We give two generic algorithms
which allow to transform generalized version of single-message broadcast
algorithms into multi-message broadcast algorithms. Based on these generic
algorithms, we obtain multi-message broadcast algorithms for dynamic radio
networks for a number of different dynamic network settings. For one of the
modeling assumptions, our algorithms are complemented by a lower bound which
shows that the upper bound is close to optimal.


title: Ricci curvature and Orientability

abstract:
  In this paper we define an orientation of a measured Gromov-Hausdorff limit
space of Riemannian manifolds with uniform Ricci bounds from below. This is the
first observation of orientability for metric measure spaces. Our orientability
has two fundamental properties. One of them is the stability with respect to
noncollapsed sequences. As a corollary we see that if the cross section of a
tangent cone of a noncollapsed limit space of orientable Riemannian manifolds
is smooth, then it is also orientable in the ordinary sense, which can be
regarded as a new obstruction for a given manifold to be the cross section of a
tangent cone. The other one is that there are only two choices for orientations
on a limit space. We also discuss relationships between $L^2$-convergence of
orientations and convergence of currents in metric spaces. In particular for a
noncollapsed sequence, we prove a compatibility between the intrinsic flat
convergence by Sormani-Wenger, the pointed flat convergence by Lang-Wenger, and
the Gromov-Hausdorff convergence, which is a generalization of a recent work by
Matveev-Portegies to the noncompact case. Moreover combining this compatibility
with the second property of our orientation gives an explicit formula for the
limit integral current by using an orientation on a limit space. Finally
dualities between de Rham cohomologies on an oriented limit space are proven.


title: Models and Methods for Three External Ballistics Inverse Problems

abstract:
  We consider three problems of selecting optimal gun barrel direction (or
those of selecting optimal semiaxis position) when firing an unguided artillery
projectile on the assumption that the gun barrel semiaxis can move in a
connected nonconvex cone having a non-smooth lateral surface and modelling
visibility zone restrictions. In the first problem, the target is in the true
horizon plane of the gun, the second and the third problems deal with some
region of 3D space. A distinctive feature of the models is that the objective
functions are $\varepsilon$-Lipschitz ones. We have constructed a unified
numerical method to solve these problems based on an algorithm of projecting a
point onto $\varepsilon$-Lipschitz level function set. A computer program has
been based on it. A series of numerical experiments on each problem has been
carried out. App. 1.


title: Transfinite mutations in the completed infinity-gon

abstract:
  We introduce mutation along infinite admissible sequences for infinitely
marked surfaces, that is surfaces with infinitely many marked points on the
boundary. We show that mutation along such admissible sequences produces a
preorder on the set of triangulations of a fixed infinitely marked surface. We
provide a complete classification of the strong mutation equivalence classes of
triangulations of the infinity- gon and the completed infinity-gon
respectively, where strong mutation equivalence is the equivalence relation
induced by this preorder. Finally, we introduce the notion of transfinite
mutations in the completed infinity-gon and show that all its triangulations
are transfinitely mutation equivalent, that is we can reach any triangulation
of the completed infinity-gon from any other triangulation via a transfinite
mutation.


title: Evidences for higher nocturnal seismic activity at the Mt. Vesuvius

abstract:
  We analyze hourly seismic data measured at the Osservatorio Vesuviano Ovest
(OVO, 1972-2014) and at the Bunker Est (BKE, 1999-2014) stations on the Mt.
Vesuvius. The OVO record is complete for seismic events with magnitude M > 1.9.
We demonstrate that before 1996 this record presents a daily oscillation that
nearly vanishes afterwards. To determine whether a daily oscillation exists in
the seismic activity of the Mt. Vesuvius, we use the higher quality BKE record
that is complete for seismic events with magnitude M > 0.2. We demonstrate that
BKE confirms that the seismic activity at the Mt. Vesuvius is higher during
nighttime than during day-time. The amplitude of the daily oscillation is
enhanced during summer and damped during winter. We speculate possible links
with the cooling/warming diurnal cycle of the volcanic edifice, with external
geomagnetic field and with magnetostriction that should also stress the rocks.
We find that the amplitude of the seismic daily cycle changes in time and has
been increasing since 2008. Finally, we propose a seismic activity index to
monitor the 24-hour oscillation that could be used to complement other
methodologies currently adopted to determine the seismic status of the volcano
and to prevent the relative hazard.


title:
Quark Propagator with electroweak interactions in the Dyson-Schwinger
  approach

abstract:
  Motivated by the non-negligible dynamical backcoupling of the electroweak
interactions with the strong interaction during neutron star mergers, we study
the effects of the explicit breaking of C, P and flavor symmetry on the strong
sector. The quark propagator is the simplest object which encodes the
consequences of these breakings. To asses the impact, we study the influence of
especially parity violation on the propagator for various masses. For this
purpose the functional methods in form of Dyson-Schwinger-Equations are
employed. We find that explicit isospin breaking leads to a qualitative change
of behavior even for a slight explicit breaking, which is in contrast to the
expectations from perturbation theory. Our results thus suggest that
non-perturbative backcoupling effects could be larger than expected.


title:
Influence of synoptic and local atmospheric patterns on PM10 air
  pollution levels: a model application to Naples (Italy)

abstract:
  We investigate the relationship between synoptic/local meteorological
patterns and PM10 air pollution levels in the metropolitan area of Naples,
Italy. We found that severe air pollution crises occurred when the 850 and 500
hpa geopotential heights and their relative temperatures present maximum values
above the city. The most relevant synoptic parameter was the 850 hPa
geopotential height, which is located about 1500 m of altitude. We compared
local meteorological conditions (specifically wind stress, rain amount and
thermal inversion) against the urban air pollution levels from 2009 to 2013. We
found several empirical criteria for forecasting high daily PM10 air pollution
levels in Naples. Pollution crises occurred when (a) the wind stress was
between 1 and 2 m/s, (b) the thermal inversion between two strategic locations
was at least 3{\deg}C/200m and (c) it did not significantly rain for at least 7
days. Beside these meteorological conditions, severe pollution crises occurred
also during festivals when fireworks and bonfires are lighted, and during
anomalous breeze conditions and severe fire accidents. Finally, we propose a
basic model to predict PM10 concentration levels from local meteorological
conditions that can be easily forecast a few days in advance. The synthetic
PM10 record predicted by the model was found to correlate with the PM10
observations with a correlation coefficient close to 0.80 with a confidence
greater than 99%. The proposed model is expected to provide reliable
information to city officials to carry out practical strategies to mitigate air
pollution effects. Although the proposed model equation is calibrated on the
topographical and meteorological conditions of Naples, it should be easily
adaptable to alternative locations.


title: Quantum spin transistor with a Heisenberg spin chain

abstract:
  We propose and analyze a scheme for conditional state transfer in a
Heisenberg $XXZ$ spin chain which realizes a quantum spin transistor. In our
scheme, the absence or presence of a control spin excitation in the central
gate part of the spin chain results in either perfect transfer of an arbitrary
state of a target spin between the weakly coupled input and output ports, or
its complete blockade at the input port. We also present a possible realization
of the corresponding spin chain with a one-dimensional ensemble of cold atoms
with strong contact interactions.


title: Stochastic energy sink in a low-dimensional Hamiltonian system

abstract:
  A few-degrees-of-freedom Hamiltonian model exhibiting one-directional
long-term trends in energy exchange flows is introduced. The model includes a
massive potential well - a container with one or few relatively light
non-interacting particles \ - attached to a linearly elastic spring. No
phenomenological dissipation is imposed, nevertheless, due to a similarity of
the container shapes to typical stochastic soft-wall billiards, the energy is
transferred from the container (donor) to the inner particles (acceptor) in
almost irreversible way during physically reasonable time intervals. The
potential well is introduced in such a way that, in the rigid-body limit, it
resembles either Sinai billiards or the so-called Buminovich stadiums as the
main geometrical parameter of the well switches its sign. In particular, using
the nonlinear normal mode stability concept reveals conditions of stochasticity
and determines the analogy with the dynamic properties of billiards. Possible
applications to the design of macro-level energy absorbers, harvesters, and
energy absorbing materials are discussed.


title: Constrained Optimal Transport

abstract:
  The classical duality theory of Kantorovich and Kellerer for the classical
optimal transport is generalized to an abstract framework and a
characterization of the dual elements is provided. This abstract generalization
is set in a Banach lattice $\cal{X}$ with a order unit. The primal problem is
given as the supremum over a convex subset of the positive unit sphere of the
topological dual of $\cal{X}$ and the dual problem is defined on the bi-dual of
$\cal{X}$. These results are then applied to several extensions of the
classical optimal transport.


title:
GMRT 610-MHz observations of the faint radio source population - and
  what these tell us about the higher-radio-frequency sky

abstract:
  We present 610-MHz Giant Metrewave Radio Telescope observations of 0.84
deg$^2$ of the AMI001 field (centred on $00^{\rm h} 23^{\rm m} 10^{\rm s}$,
$+31^{\circ} 53'$) with an r.m.s. noise of 18 $\mu$Jy beam$^{-1}$ in the centre
of the field. 955 sources are detected, and 814 are included in the source
count analysis. The source counts from these observations are consistent with
previous work. We have used these data to study the spectral index distribution
of a sample of sources selected at 15.7 GHz from the recent deep extension to
the Tenth Cambridge (10C) survey. The median spectral index, $\alpha$, (where
$S \propto \nu^{-\alpha}$) between $0.08 < S_{15.7~\rm GHz} / \rm mJy < 0.2$ is
$0.32 \pm 0.14$, showing that star-forming galaxies, which have much steeper
spectra, are not contributing significantly to this population. This is in
contrast to several models, but in agreement with the results from the 10C
ultra-deep source counts; the high-frequency sky therefore continues to be
dominated by radio galaxies down to $S_{15.7~\rm GHz} = 0.1$ mJy.


title:
The crystalline structure of orthorhombic SrRuO$_3$: Application of
  hybrid scheme to the density functionals revised for solids

abstract:
  The crystalline structure of ground-state orthorhombic SrRuO$_3$ is
reproduced by applying hybrid density functional theory scheme to the
functionals based on the revised generalized-gradient approximations for
solid-state calculations. The amount of Hartree-Fock (HF) exchange energy is
varied in the range of $5-20\%$ in order to systematically ascertain the
optimum value of HF mixing which in turn ensures the best correspondence to the
experimental measurements. Such investigation allows to expand the set of tools
that could be used for the efficient theoretical modelling of, for example,
only recently stabilized phases of SrRuO$_3$.


title:
Diffusion LMS for Multitask Problems with Local Linear Equality
  Constraints

abstract:
  We consider distributed multitask learning problems over a network of agents
where each agent is interested in estimating its own parameter vector, also
called task, and where the tasks at neighboring agents are related according to
a set of linear equality constraints. Each agent possesses its own convex cost
function of its parameter vector and a set of linear equality constraints
involving its own parameter vector and the parameter vectors of its neighboring
agents. We propose an adaptive stochastic algorithm based on the projection
gradient method and diffusion strategies in order to allow the network to
optimize the individual costs subject to all constraints. Although the
derivation is carried out for linear equality constraints, the technique can be
applied to other forms of convex constraints. We conduct a detailed
mean-square-error analysis of the proposed algorithm and derive closed-form
expressions to predict its learning behavior. We provide simulations to
illustrate the theoretical findings. Finally, the algorithm is employed for
solving two problems in a distributed manner: a minimum-cost flow problem over
a network and a space-time varying field reconstruction problem.


title: Coronal Dynamic Activities in the Declining Phase of a Solar Cycle

abstract:
  It has been known that some solar activity indicators show a double-peak
feature in their evolution through a solar cycle, which is not conspicuous in
sunspot number. In this letter, we investigate the high solar dynamic activity
in the declining phase of the sunspot cycle by examining the evolution of polar
and low latitude coronal hole areas and the statistics of splitting and merging
events of coronal holes and coronal mass ejections detected by SOHO/LASCO C3 in
solar cycle 23. Although the total coronal hole area is at its maximum near the
sunspot minimum, in which polar coronal holes prevail, it shows a comparable
second maximum in the declining phase of the cycle, in which low latitude
coronal holes are dominant. The events of coronal hole splitting or merging,
which are attributed to surface motions of magnetic fluxes, are also mostly
populated in the declining phase of the cycle. The far-reaching C3 coronal mass
ejections are also over-populated in the declining phase of the cycle. From
these results we suggest that solar dynamic activities due to the horizontal
motions of magnetic fluxes extend far in the declining phase of the sunspot
cycle.


title: Multilayer diffusion in a composite medium with imperfect contact

abstract:
  The problem of heat conduction in one-dimensional piecewise homogeneous
composite materials is examined by providing an explicit solution of the
one-dimensional heat equation in each domain. The location of the interfaces is
known, but neither temperature nor heat flux are prescribed there. We find a
solution using the Unified Transform Method, due to Fokas and collaborators,
applied to interface problems and compute solutions numerically.


title:
Variation in energy stored and dissipated in type-II superconductor in
  applied ac magnetic field with relative phase of two sinusoidal components of
  the field

abstract:
  We show that both the energy stored and dissipated by a system with
hysteretic nonlinearity in an applied field varies with the relative phase of
the sinusoidal components of the field, even if the magnitude of these
components, and thus an effective value of the field, are kept constant. The
explored system is a type-II superconductor in the critical state subjected to
a time varying applied magnetic field. Complete analytical expressions for
hysteresis loops, determined from basic physical phenomena, are known for this
system. A theoretically predicted variation in the energy is in good agreement
with our experimental measurements.


title:
End-to-end Concept Word Detection for Video Captioning, Retrieval, and
  Question Answering

abstract:
  We propose a high-level concept word detector that can be integrated with any
video-to-language models. It takes a video as input and generates a list of
concept words as useful semantic priors for language generation models. The
proposed word detector has two important properties. First, it does not require
any external knowledge sources for training. Second, the proposed word detector
is trainable in an end-to-end manner jointly with any video-to-language models.
To maximize the values of detected words, we also develop a semantic attention
mechanism that selectively focuses on the detected concept words and fuse them
with the word encoding and decoding in the language model. In order to
demonstrate that the proposed approach indeed improves the performance of
multiple video-to-language tasks, we participate in four tasks of LSMDC 2016.
Our approach achieves the best accuracies in three of them, including
fill-in-the-blank, multiple-choice test, and movie retrieval. We also attain
comparable performance for the other task, movie description.


title:
A Framework for the Upscaling of the Electrical Conductivity in the
  Quasi-static Maxwell's Equations

abstract:
  Electromagnetic simulations of complex geologic settings are computationally
expensive. One reason for this is the fact that a fine mesh is required to
accurately discretize the electrical conductivity model of a given setting.
This conductivity model may vary over several orders of magnitude and these
variations can occur over a large range of length scales. Using a very fine
mesh for the discretization of this setting leads to the necessity to solve a
large system of equations that is often difficult to deal with. To keep the
simulations computationally tractable, coarse meshes are often employed for the
discretization of the model. Such coarse meshes typically fail to capture the
fine-scale variations in the conductivity model resulting in inaccuracies in
the predicted data. In this work, we introduce a framework for constructing a
coarse-mesh or upscaled conductivity model based on a prescribed fine-mesh
model. Rather than using analytical expressions, we opt to pose upscaling as a
parameter estimation problem. By solving an optimization problem, we obtain a
coarse-mesh conductivity model. The optimization criterion can be tailored to
the survey setting in order to produce coarse models that accurately reproduce
the predicted data generated on the fine mesh. This allows us to upscale
arbitrary conductivity structures, as well as to better understand the meaning
of the upscaled quantity. We use 1D and 3D examples to demonstrate that the
proposed framework is able to emulate the behavior of the heterogeneity in the
fine-mesh conductivity model, and to produce an accurate description of the
desired predicted data obtained by using a coarse mesh in the simulation
process.


title:
Cluster dynamics modelling of materials: a new hybrid
  deterministic/stochastic coupling approach

abstract:
  Deterministic simulations of the rate equations governing cluster dynamics in
materials are limited by the number of equations to integrate. Stochastic
simulations are limited by the high frequency of certain events. We propose a
coupling method combining deterministic and stochastic approaches. It allows
handling different time scale phenomena for cluster dynamics. This method,
based on a splitting of the dynamics, is generic and we highlight two different
hybrid deterministic/stochastic methods. These coupling schemes are highly
parallelizable and specifically designed to treat large size cluster problems.
The proof of concept is made on a simple model of vacancy clustering under
thermal ageing.


title: Cumulative pion production via successive collisions in nuclear medium

abstract:
  Production of pions in proton-nucleus (p+A) reactions outside of a
kinematical boundary of proton-nucleon collisions, the so-called cumulative
effect, is studied. The kinematical restrictions on pions emitted in backward
direction in the target rest frame are analyzed. It is shown that cumulative
pion production requires a presence of massive baryonic resonances that are
produced during successive collisions of projectile with nuclear nucleons.
After each successive collision the mass of created resonance may increase and,
simultaneously, its longitudinal velocity decreases. Simulations within Ultra
relativistic Quantum Molecular Dynamics model reveals that successive
collisions of baryonic resonances with nuclear nucleons plays the dominant role
in cumulative pion production in p+A reactions.


title: Conformal mapping of the Misner-Sharp mass from gravitational collapse

abstract:
  The conformal transformation of the Misner-Sharp mass is reexamined. It has
recently been found that this mass does not transform like usual masses do
under conformal mappings of spacetime. We show that when it comes to conformal
transformations, the widely used geometric definition of the Misner-Sharp mass
is fundamentally different from the original conception of the latter. Indeed,
when working within the full hydrodynamic setup that gave rise to that mass,
i.e. the physics of gravitational collapse, the familiar conformal
transformation of a usual mass is recovered. The case of scalar-tensor theories
of gravity is also examined.


title: Incrementally Closing Octagons

abstract:
  The octagon abstract domain is a widely used numeric abstract domain
expressing relational information between variables whilst being both
computationally efficient and simple to implement. Each element of the domain
is a system of constraints where each constraint takes the restricted form $\pm
x_i \pm x_j \leq d$. A key family of operations for the octagon domain are
closure algorithms, which check satisfiability and provide a normal form for
octagonal constraint systems. We present new quadratic incremental algorithms
for closure, strong closure and integer closure and proofs of their
correctness. We highlight the benefits and measure the performance of these new
algorithms.


title: Comments on Dumitrescu's "A Selectable Sloppy Heap"

abstract:
  Dumitrescu [arXiv:1607.07673] describes a data structure referred to as a
Selectable Sloppy Heap. We present a simplified approach, and also point out
aspects of Dumitrescu's exposition that require scrutiny.


title:
Classical and Quantum Part of the Environment for Quantum Langevin
  Equations

abstract:
  Among quantum Langevin equations describing the unitary time evolution of a
quantum system in contact with a quantum bath, we completely characterize those
equations which are actually driven by classical noises. The characterization
is purely algebraic, in terms of the coefficients of the equation. In a second
part, we consider general quantum Langevin equations and we prove that they can
always be split into a maximal part driven by classical noises and a purely
quantum one.

categories: math-ph math.MP math.OA math.PR quant-ph


title:
A two player zerosum game where only one player observes a Brownian
  motion

abstract:
  We study a two-player zero-sum game in continuous time, where the payoff-a
running cost-depends on a Brownian motion. This Brownian motion is observed in
real time by one of the players. The other one observes only the actions of his
opponent. We prove that the game has a value and characterize it as the largest
convex subsolution of a Hamilton-Jacobi equation on the space of probability
measures.


title: The Integrated Bispectrum in Modified Gravity Theories

abstract:
  Gravity-induced non-Gaussianity can provide important clues to Modified
Gravity (MG) Theories. Several recent studies have suggested using the {\it
Integrated Bispectrum} (IB) as a probe for squeezed configuration of
bispectrum. Extending previous studies on the IB, we include redshift-space
distortions to study a class of (parametrised) MG theories that include the
string-inspired Dvali, Gabadadze \& Porrati (DGP) model. Various contributions
from redshift-space distortions are derived in a transparent manner, and
squeezed contributions from these terms are derived separately. Results are
obtained using the Zel'dovich Approximation (ZA). Results are also presented
for projected surveys (2D). We use the Press-Schechter (PS) and Sheth-Torman
(ST) mass functions to compute the IB for collapsed objects that can readily be
extended to peak-theory based approaches. The {\em cumulant correlators} (CCs)
generalise the ordinary {\em cumulants} and are known to probe collapsed
configurations of higher order correlation functions. We generalise the concept
of CCs to halos of different masses. We also introduce a generating function
based approach to analyse more general non-local biasing models. The Fourier
representations of the CCs, the skew-spectrum, or the kurt-spctra are discussed
in this context. The results are relevant for the study of the Minkowski
Functionals (MF) of collapsed tracers in redshift-space.} \keywords {Cosmology,
Large Scale Structure, Modified Theories of Gravity


title: On the Spectra of Symmetric Cylindrical Constructs

abstract:
  In this article, following [A.~Daneshgar, M.~Hejrati, M.~Madani, {\it On
cylindrical graph construction and its applications}, EJC, 23(1) p1.29, 45,
2016] we study the spectra of symmetric cylindrical constructs, generalizing
some well-known results on the spectra of a variety of graph products, graph
subdivisions by V.~B.~Mnuhin (1980) and the spectra of GI-graphs (see
[M.~Conder, T.~Pisanski, and A.~{\v{Z}}itnik, {\it GI-graphs: a new class of
graphs with many symmetries}, 40, 209--231 (2014)] and references therein). In
particular, we show that for bsymmetric cylinders with no internal vertex the
spectra is actually equal to the eigenvalues of a perturbation of the base, and
using this, we study the spectra of sparsifications of complete graphs by
tree-cylinders. We also, show that a specific version of this construction
gives rise to a class of highly symmetric graphs as a generalization of
Petersen and Coxeter graphs.


title: Projective dimension and regularity of the path ideal of the line graph

abstract:
  By generalizing the notion of the path ideal of a graph, we study some
algebraic properties of some path ideals associated to a line graph. We show
that the quotient ring of these ideals are always sequentially Cohen-Macaulay
and also provide some exact formulas for the projective dimension and the
regularity of these ideals. As some consequences, we give some exact formulas
for the depth of these ideals.


title: X-ray tomographic intervention guidance: Towards real-time 4D imaging

abstract:
  Implementation of real-time, continuous, and three-dimensional imaging (4D
intervention guidance) would be a quantum leap for minimally-invasive medicine.
It allows guidance during interventions by assessing the spatial position of
instruments continuously in respect to their surroundings. Recent research
showed that it is feasible using X-ray and novel tomographic reconstruction
approaches. Radiation dose stays within reasonable limits. This article
provides abstractions and background information together with an outlook on
these prospects. There are explanations of how situational awareness during
interventions is generated today and how they will be in future. The
differences between fluoroscopically and CT-guided interventions are eluted to
within the context of these developments. The exploration of uncharted terrain
between these current methods is worth pursuing. Necessary image quality of 4D
intervention guidance varies relevantly from that of standard computed
tomography. Means to analyze the risk-benefit ratio of 4D intervention guidance
are provided and arguments for gantry-based setups vs C-arm based setups are
given. Due to the lack of moving organs, neuro-interventions might be the first
field in which 4D intervention guidance might become available, however,
registration and fusion algorithms might make it applicable in complex
whole-body interventions such as aortic valve replacement soon thereafter.


title:
Search for high-mass Z-gamma resonances in e+e-gamma and mu+mu-gamma
  final states in proton-proton collisions at sqrt(s) = 8 and 13 TeV

abstract:
  This paper describes the search for a high-mass narrow-width scalar particle
decaying into a Z boson and a photon. The analysis is performed using
proton-proton collision data recorded with the CMS detector at the LHC at
center-of-mass energies of 8 and 13 TeV, corresponding to integrated
luminosities of 19.7 and 2.7 inverse femtobarns, respectively. The Z bosons are
reconstructed from opposite-sign electron or muon pairs. No statistically
significant deviation from the standard model predictions has been found in the
200-2000 GeV mass range. Upper limits at 95% confidence level have been derived
on the product of the scalar particle production cross section and the
branching fraction of the Z decaying into electrons or muons, which range from
280 to 20 fb for resonance masses between 200 and 2000 GeV.


title: General aspects of effective field theories and few-body applications

abstract:
  Effective field theory provides a powerful framework to exploit a separation
of scales in physical systems. In these lectures, we discuss some general
aspects of effective field theories and their application to few-body physics.
In particular, we consider an effective field theory for non-relativistic
particles with resonant short-range interactions where certain parts of the
interaction need to be treated nonperturbatively. As an application, we discuss
the so-called pionless effective field theory for low-energy nuclear physics.
The extension to include long-range interactions mediated by photon and
pion-exchange is also addressed.


title: Low-Rank Dynamic Mode Decomposition: An Exact and Tractable Solution

abstract:
  This work studies the linear approximation of high-dimensional dynamical
systems using low-rank dynamic mode decomposition (DMD). Searching this
approximation in a data-driven approach is formalised as attempting to solve a
low-rank constrained optimisation problem. This problem is non-convex and
state-of-the-art algorithms are all sub-optimal. This paper shows that there
exists a closed-form solution, which is computed in polynomial time, and
characterises the l2-norm of the optimal approximation error. The paper also
proposes low-complexity algorithms building reduced models from this optimal
solution, based on singular value decomposition or eigen value decomposition.
The algorithms are evaluated by numerical simulations using synthetic and
physical data benchmarks.


title:
Aspects of the low-energy constants in the chiral Lagrangian for charmed
  mesons

abstract:
  We investigate the numerical values of the low-energy constants in the chiral
effective Lagrangian for the interactions between the charmed mesons and the
lightest pseudoscalar mesons, the Goldstone bosons of the spontaneous breaking
of chiral symmetry for QCD. This problem is tackled from two sides: estimates
using the resonance exchange model, and positivity constraints from the general
properties of the $S$-matrix including analyticity, crossing symmetry and
unitarity. These estimates and constraints are compared with the values
determined from fits to lattice data of the scattering lengths. Tensions are
found, and possible reasons are discussed. We conclude that more data from
lattice calculations and experiments are necessary to fix these constants
better. As a by-product, we also estimate the coupling constant $g_{DDa_2}$,
with $a_2$ the light tensor meson, via the QCD sum rule approach.


title:
Observational constraints on the formation and evolution of the Milky
  Way nuclear star cluster with Keck and Gemini

abstract:
  Due to its proximity, the Milky Way nuclear star cluster provides us with a
wealth of data not available in other galactic nuclei. In particular, with
adaptive optics, we can observe the detailed properties of individual stars,
which can offer insight into the origin and evolution of the cluster. We
summarize work on the central parsec of the Galactic center based on imaging
and spectroscopic observations at the Keck and Gemini telescopes. These
observations include stellar positions in two dimension and the velocity in
three dimensions. Spectroscopic observations also enable measurements of the
physical properties of individual stars, such as the spectral type and in some
cases the effective temperature, metallicity, and surface gravity. We present a
review of our latest measurements of the density profiles and luminosity
functions of the young and old stars in this region. These observations show a
complex stellar population with a young (4-6 Myr) compact star cluster in the
central 0.5 pc embedded in an older and much more massive nuclear star cluster.
Surprisingly, the old late-type giants do not show a cusp profile as long been
expected from theoretical work. The solution to the missing cusp problem may
offer us insight into the dynamical evolution of the cluster. Finally, we also
discuss recent work on the metallicity of stars in this region and how they
might be used to trace their origin. The nuclear star cluster shows a large
variation in metallicity ([M/Fe]). The majority of the stars have higher than
solar metallicity, with about 6\% having [M/Fe] $< -0.5$. These observations
indicate that the NSC was not built from the globular clusters that we see
today. The formation of the nuclear star cluster is more likely from the inward
migration of gas originating in the disk of the Milky Way.


title: A q-analog of Schl\"afli and Gould identities on Stirling numbers

abstract:
  Stirling numbers of both kinds are linked to each other via two combinatorial
identities due to Schl\"afli and Gould. Using q-analogs of Stirling numbers
defined as inversion generating functions, we provide q-analogs of the two
identities. The proof is computational and we leave open the problem of finding
a more combinatorial one.


title:
Auslander-Gorenstein algebras, standardly stratified algebras and
  dominant dimensions

abstract:
  We give new properties of algebras with finite Gorenstein dimension
coinciding with the dominant dimension $\geq 2$, which are called
Auslander-Gorenstein algebras in the recent work of Iyama and Solberg, see
\cite{IyaSol}. In particular, when those algebras are standardly stratified, we
give criteria when the category of (properly) (co)standardly filtered modules
has a nice homological description using tools from the theory of dominant
dimensions and Gorenstein homological algebra. We give some examples of
standardly stratified algebras having dominant dimension equal to the
Gorenstein dimension, including examples having an arbitrary natural number as
Gorenstein dimension and blocks of finite representation-type of Schur
algebras.


title: Distributed Convex Optimization with Many Convex Constraints

abstract:
  We address the problem of solving convex optimization problems with many
convex constraints in a distributed setting. Our approach is based on an
extension of the alternating direction method of multipliers (ADMM) that
recently gained a lot of attention in the Big Data context. Although it has
been invented decades ago, ADMM so far can be applied only to unconstrained
problems and problems with linear equality or inequality constraints. Our
extension can handle arbitrary inequality constraints directly. It combines the
ability of ADMM to solve convex optimization problems in a distributed setting
with the ability of the Augmented Lagrangian method to solve constrained
optimization problems, and as we show, it inherits the convergence guarantees
of ADMM and the Augmented Lagrangian method.


title: Ideograms for Physics and Chemistry

abstract:
  Ideograms (symbols that represent a word or idea) have great communicative
value. They refer to concepts in a simple manner, easing the understanding of
related ideas. Moreover, ideograms can simplify the often cumbersome notation
used in the fields of Physics and physical Chemistry. Nonetheless only a few
specific ideograms for these fields have been defined to date. In this work we
propose that the scientific community follows the example of Mathematics -as
well as that of oriental languages- and bestows a more important role upon
ideograms. To support this thesis we propose ideograms for essential concepts
in Physics and Chemistry. They are designed to be intuitive, and their goal is
to make equations easier to read and understand. Our symbols are included in a
publicly available Latex package (svrsymbols).


title: Flare differentially rotates sunspot on Sun's surface

abstract:
  Sunspots are concentrations of magnetic field visible on the solar surface
(photosphere). It was considered implausible that solar flares, as resulted
from magnetic reconnection in the tenuous corona, would cause a direct
perturbation of the dense photosphere involving bulk motion. Here we report the
sudden flare-induced rotation of a sunspot using the unprecedented
spatiotemporal resolution of the 1.6 m New Solar Telescope, supplemented by
magnetic data from the Solar Dynamics Observatory. It is clearly observed that
the rotation is non-uniform over the sunspot: as the flare ribbon sweeps
across, its different portions accelerate (up to 50 deg per hr) at different
times corresponding to peaks of flare hard X-ray emission. The rotation may be
driven by the surface Lorentz-force change due to the back reaction of coronal
magnetic restructuring and is accompanied by a downward Poynting flux. These
results have direct consequences for our understanding of energy and momentum
transportation in the flare-related phenomena.


title: Compact localized states and flatband generators in one dimension

abstract:
  Flat bands (FB) are strictly dispersionless bands in the Bloch spectrum of a
periodic lattice Hamiltonian, recently observed in a variety of photonic and
dissipative condensate networks. FB Hamiltonians are finetuned networks, still
lacking a comprehensive generating principle. We introduce a FB generator based
on local network properties. We classify FB networks through the properties of
compact localized states (CLS) which are exact FB eigenstates and occupy $U$
unit cells. We obtain the complete two-parameter FB family of two-band $d=1$
networks with nearest unit cell interaction and $U=2$. We discover a novel high
symmetry sawtooth chain with identical hoppings in a transverse dc field,
easily accessible in experiments. Our results pave the way towards a complete
description of FBs in networks with more bands and in higher dimensions.


title: Some conjectures on the asymptotic behavior of Gromov-Witten invariants

abstract:
  The purpose of this note is to share some observations and speculations
concerning the asymptotic behavior of Gromov-Witten invariants. They may be
indicative of some deep phenomena in symplectic topology that in full
generality are outside of the reach of current techniques. On the other hand,
many interesting cases can perhaps be treated via combinatorial techniques.


title: Parametric Instability Rates in Periodically-Driven Band Systems

abstract:
  This work analyses the dynamical properties of periodically-driven band
models. Focusing on the case of Bose-Einstein condensates, and using a
meanfield approach to treat inter-particle collisions, we identify the origin
of dynamical instabilities arising due to the interplay between the external
drive and interactions. We present a widely-applicable generic numerical method
to extract instability rates, and link parametric instabilities to uncontrolled
energy absorption at short times. Based on the existence of parametric
resonances, we then develop an analytical approach within Bogoliubov theory,
which quantitatively captures the instability rates of the system, and provides
an intuitive picture of the relevant physical processes, including an
understanding of how transverse modes affect the formation of parametric
instabilities. Importantly, our calculations demonstrate an agreement between
the instability rates determined from numerical simulations, and those
predicted by theory. To determine the validity regime of the meanfield
analysis, we compare the latter to the weakly-coupled conserving approximation.
The tools developed and the results obtained in this work are directly relevant
to present-day ultracold-atom experiments based on shaken optical lattices, and
are expected to provide an insightful guidance in the quest for Floquet
engineering.


title: Particle production in a gravitational wave background

abstract:
  We study the possibility that massless particles, such as photons, are
produced by a gravitational wave. That such a process should occur is implied
by tree-level, Feynman diagrams such as two gravitons turning into two photons
i.e. $g + g \rightarrow \gamma + \gamma$. Here we calculate the rate at which a
gravitational wave creates a massless, scalar field. This is done by placing
the scalar field in the background of a plane gravitational wave and
calculating the 4-current of the scalar field. Even in the vacuum limit of the
scalar field it has a non-zero vacuum expectation value (similar to what occurs
in the Higgs mechanism) and a non-zero current. We associate this with the
production of scalar field quanta by the gravitational field. This effect has
potential consequences for the attenuation of gravitational waves since the
massless field is being produced at the expense of the gravitational field.
This is related to the time-dependent Schwinger effect, but with the electric
field replaced by the the gravitational wave background and the
electron/positron field quanta replaced by massless scalar "photons". Since the
produced scalar quanta are massless there is no exponential suppression as
occurs in the Schwinger effect due to the electron mass.


title:
Implementation of transmission functions for an optimized three-terminal
  quantum dot heat engine

abstract:
  We consider two modifications of a recently proposed three-terminal quantum
dot heat engine. First, we investigate the necessity of the thermalization
assumption, namely that electrons are always thermalized by inelastic processes
when traveling across the cavity where the heat is supplied. Second, we analyze
various arrangements of tunneling-coupled quantum dots in order to implement a
transmission function that is superior to the Lorentzian transmission function
of a single quantum dot. We show that the maximum power of the heat engine can
be improved by about a factor of two, even for a small number of dots, by
choosing an optimal structure.


title: Conformal blocks, Verlinde formula and diagram automorphisms

abstract:
  The Verlinde formula computes the dimension of conformal blocks associated to
simple Lie algebras and stable pointed curves. If a simply-laced simple Lie
algebra admits a nontrivial diagram automorphism, then this automorphism acts
on the space of conformal blocks naturally. We prove an analogue of Verlinde
formula for the trace of the diagram automorphism on the space of conformal
blocks. Along the way, we get an analogue of Kac-Walton formula for the trace
of the diagram automorphism. We also get a twining type formula between the
conformal blocks for the pair $(sl(2n+1),sp(2n))$.


title: Manifest and Subtle Cyclic Behavior in Nonequilibrium Steady States

abstract:
  Many interesting phenomena in nature are described by stochastic processes
with irreversible dynamics. To model these phenomena, we focus on a master
equation or a Fokker-Planck equation with rates which violate detailed balance.
When the system settles in a stationary state, it will be a nonequilibrium
steady state (NESS), with time independent probability distribution as well as
persistent probability current loops. The observable consequences of the latter
are explored. In particular, cyclic behavior of some form must be present: some
are prominent and manifest, while others are more obscure and subtle. We
present a theoretical framework to analyze such properties, introducing the
notion of "probability angular momentum" and its distribution. Using several
examples, we illustrate the manifest and subtle categories and how best to
distinguish between them. These techniques can be applied to reveal the NESS
nature of a wide range of systems in a large variety of areas. We illustrate
with one application: variability of ocean heat content in our climate system.


title: Two-particle interferometry in quantum Hall edge channels

abstract:
  Since pioneering works of Hanbury-Brown and Twiss, intensity-intensity
correlations have been widely used in astronomical systems, for example to
detect binary stars. They reveal statistics effects and two-particle
interference, and offer a decoherence-free probe of the coherence properties of
light sources. In the quantum Hall edge channels, the concept of quantum optics
can transposed to electrons, and an analogous two-particle interferometry can
be developed, in order to characterize single-electron states. We review in
this article the recent experimental and theoretical progress on this topic.


title: Number of points on a family of curves over a finite field

abstract:
  In this paper we study a family of curves obtained by fibre products of
hyperelliptic curves. We then exploit this family to construct examples of
curves of given genus g over a finite field Fq with many rational points. The
results obtained improve the known bounds for a few pairs (q, g).


title: Biased random walk on the interlacement set

abstract:
  We study a biased random walk on the interlacement set of $\mathbb{Z}^d$ for
$d\geq 3$. Although the walk is always transient, we can show, in the case
$d=3$, that for any value of the bias the walk has a zero limiting speed and
actually moves slower than any power.


title:
Optical elastic scattering for early label-free identification of
  clinical pathogens

abstract:
  We report here on the ability of elastic light scattering in discriminating
Gram+, Gram-and yeasts at an early stage of growth (6h). Our technique is
non-invasive, low cost and does require neither skilled operators nor reagents.
Therefore it is compatible with automation. It is based on the analysis of the
scattering pattern (scatterogram) generated by a bacterial microcolony growing
on agar, when placed in the path of a laser beam. Measurements are directly
performed on closed Petri dishes. The characteristic features of a given
scatterogram are first computed by projecting the pattern onto the Zernike
orthogonal basis. Then the obtained data are compared to a database so that
machine learning can yield identification result. A 10-fold cross-validation
was performed on a database over 8 species (15 strains, 1906 scatterograms), at
6h of incubation. It yielded a 94% correct classification rate between Gram+,
Gram-and yeasts. Results can be improved by using a more relevant function
basis for projections, such as Fourier-Bessel functions. A fully integrated
instrument has been installed at the Grenoble hospital's laboratory of
bacteriology and a validation campaign has been started for the early screening
of SA and MRSA (Staphylococcus aureus, methicillin-resistant S. aureus)
carriers. Up to now, all the published studies about elastic scattering were
performed in a forward mode, which is restricted to transparent media. However,
in clinical diagnostics, most of media are opaque, such as blood-supplemented
agar. That is why we propose a novel scheme capable of collecting
back-scattered light which provides comparable results.


title:
Radiation-hydrodynamical modelling of underluminous type II plateau
  Supernovae

abstract:
  With the aim of improving our knowledge about the nature of the progenitors
of low-luminosity Type II plateau supernovae (LL SNe IIP), we made
radiation-hydrodynamical models of the well-sampled LL SNe IIP 2003Z, 2008bk
and 2009md. For these three SNe we infer explosion energies of $0.16$-$0.18$
foe, radii at explosion of $1.8$-$3.5 \times 10^{13}$ cm, and ejected masses of
$10$-$11.3$\Msun. The estimated progenitor mass on the main sequence is in the
range $\sim 13.2$-$15.1$\Msun\, for SN 2003Z and $\sim 11.4$-$12.9$\Msun\, for
SNe 2008bk and 2009md, in agreement with estimates from observations of the
progenitors. These results together with those for other LL SNe IIP modelled in
the same way, enable us also to conduct a comparative study on this SN
sub-group. The results suggest that: a) the progenitors of faint SNe IIP are
slightly less massive and have less energetic explosions than those of
intermediate-luminosity SNe IIP, b) both faint and intermediate-luminosity SNe
IIP originate from low-energy explosions of red (or yellow) supergiant stars of
low-to-intermediate mass, c) some faint objects may also be explained as
electron-capture SNe from massive super-asymptotic giant branch stars, and d)
LL SNe IIP form the underluminous tail of the SNe IIP family, where the main
parameter "guiding" the distribution seems to be the ratio of the total
explosion energy to the ejected mass. Further hydrodynamical studies should be
performed and compared to a more extended sample of LL SNe IIP before drawing
any conclusion on the relevance of fall-back to this class of events.


title: Minimal factorizations of a cycle: a multivariate generating function

abstract:
  It is known that the number of minimal factorizations of the long cycle in
the symmetric group into a product of $k$ cycles of given lengths has a very
simple formula: it is $n^{k-1}$ where $n$ is the rank of the underlying
symmetric group and $k$ is the number of factors. In particular, this is
$n^{n-2}$ for transposition factorizations. The goal of this work is to prove a
multivariate generalization of this result. As a byproduct, we get a
multivariate analog of Postnikov's hook length formula for trees, and a refined
enumeration of final chains of noncrossing partitions.