title: Geometrization of $N$-Extended $1$-Dimensional Supersymmetry Algebras II

abstract:
  The problem of classifying off-shell representations of the $N$ -extended
one-dimensional super Poincar\'e algebra is closely related to the study of a
class of decorated $N$-regular, $N$-edge colored bipartite graphs known as
Adinkras. In previous work we canonically embedded these graphs into explicitly
uniformized Riemann surfaces via the "dessins d'enfant" construction of
Grothendieck. The Adinkra graphs carry two additional structures: a selection
of dashed edges and an assignment of integral helghts to the vertices. In this
paper, we complete the passage from algebra, through discrete structures, to
geometry. We show that the dashings correspond to special spin structures on
the Riemann surface, defining thereby super Riemann surfaces. Height
assignments determine discrete Morse functions, from which we produce a set of
Morse divisors which capture the topological properties of the height
assignments.


title: Submodular Optimization over Sliding Windows

abstract:
  Maximizing submodular functions under cardinality constraints lies at the
core of numerous data mining and machine learning applications, including data
diversification, data summarization, and coverage problems. In this work, we
study this question in the context of data streams, where elements arrive one
at a time, and we want to design low-memory and fast update-time algorithms
that maintain a good solution. Specifically, we focus on the sliding window
model, where we are asked to maintain a solution that considers only the last
$W$ items.
  In this context, we provide the first non-trivial algorithm that maintains a
provable approximation of the optimum using space sublinear in the size of the
window. In particular we give a $\frac{1}{3} - \epsilon$ approximation
algorithm that uses space polylogarithmic in the spread of the values of the
elements, $\Phi$, and linear in the solution size $k$ for any constant
$\epsilon > 0$ . At the same time, processing each element only requires a
polylogarithmic number of evaluations of the function itself. When a better
approximation is desired, we show a different algorithm that, at the cost of
using more memory, provides a $\frac{1}{2} - \epsilon$ approximation and allows
a tunable trade-off between average update time and space. This algorithm
matches the best known approximation guarantees for submodular optimization in
insertion-only streams, a less general formulation of the problem.
  We demonstrate the efficacy of the algorithms on a number of real world
datasets, showing that their practical performance far exceeds the theoretical
bounds. The algorithms preserve high quality solutions in streams with millions
of items, while storing a negligible fraction of them.


title: Physical Basis of Large Microtubule Aster Growth

abstract:
  Microtubule asters - radial arrays of microtubules organized by centrosomes -
play a fundamental role in the spatial coordination of animal cells. The
standard model of aster growth assumes a fixed number of microtubules
originating from the centrosomes. However, aster morphology in this model does
not scale with cell size, and we recently found evidence for non-centrosomal
microtubule nucleation. Here, we combine autocatalytic nucleation and
polymerization dynamics to develop a biophysical model of aster growth. Our
model predicts that asters expand as traveling waves and recapitulates all
major aspects of aster growth. As the nucleation rate increases, the model
predicts an explosive transition from stationary to growing asters with a
discontinuous jump of the growth velocity to a nonzero value. Experiments in
frog egg extract confirm the main theoretical predictions. Our results suggest
that asters observed in large frog and amphibian eggs are a meshwork of short,
unstable microtubules maintained by autocatalytic nucleation and provide a
paradigm for the assembly of robust and evolvable polymer networks.


title: Miniaturized lab system for future cold atom experiments in microgravity

abstract:
  We present the technical realization of a compact system for performing
experiments with cold $^{87}{\text{Rb}}$ and $^{39}{\text{K}}$ atoms in
microgravity in the future. The whole system fits into a capsule to be used in
the drop tower Bremen. One of the advantages of a microgravity environment is
long time evolution of atomic clouds which yields higher sensitivities in atom
interferometer measurements. We give a full description of the system
containing an experimental chamber with ultra-high vacuum conditions,
miniaturized laser systems, a high-power thulium-doped fiber laser, the
electronics and the power management. In a two-stage magneto-optical trap atoms
should be cooled to the low $\mu$K regime. The thulium-doped fiber laser will
create an optical dipole trap which will allow further cooling to sub-$\mu$K
temperatures. The presented system fulfills the demanding requirements on size
and power management for cold atom experiments on a microgravity platform,
especially with respect to the use of an optical dipole trap. A first test in
microgravity, including the creation of a cold Rb ensemble, shows the
functionality of the system.


title:
Conditions of smoothness of moduli spaces of flat connections and of
  character varieties

abstract:
  We use gauge theoretic and algebraic methods to examine sufficient conditions
for smooth points on the moduli space of flat connections on a compact manifold
and on the character variety of a finitely generated and presented group. We
give a complete proof of the slice theorem for the action of the group of gauge
transformations on the space of flat connections. Consequently, the slice is
smooth if the second cohomology of the manifold with coefficients in the
semisimple part of the adjoint bundle vanishes. On the other hand, we find that
the smoothness of the slice for the character variety of a finitely generated
and presented group depends not only on the second group cohomology but also on
the relation module of the presentation. However, when there is a single
relator or if there is no relation among the relators in the presentation, our
condition reduces to the minimality of the second group cohomology. This is
also verified using Fox calculus. Finally, we compare the conditions of
smoothness in the two approaches.


title: Selecting the Best Quadrilateral Mesh for Given Planar Shape

abstract:
  The problem of mesh matching is addressed in this work. For a given n-sided
planar region bounded by one loop of n polylines we are selecting optimal
quadrilateral mesh from existing catalogue of meshes. The formulation of
matching between planar shape and quadrilateral mesh from the catalogue is
based on the problem of finding longest common subsequence (LCS). Theoretical
foundation of mesh matching method is provided. Suggested method represents a
viable technique for selecting best mesh for planar region and stepping stone
for further parametrization of the region.


title: Gradient flow running coupling in SU(2) Nf=6 flavors

abstract:
  We present preliminary results of the running of the coupling in SU(2) gauge
theory with 6 massless fundamental representation fermion flavors. We measure
the coupling using the gradient flow method with Schr\"odinger functional
boundary conditions. The results are consistent with the perturbation theory in
the weak coupling and we see an indication of an infrared fixed point at strong
coupling.


title:
Integration of continuous-time dynamics in a spiking neural network
  simulator

abstract:
  Contemporary modeling approaches to the dynamics of neural networks consider
two main classes of models: biologically grounded spiking neurons and
functionally inspired rate-based units. The unified simulation framework
presented here supports the combination of the two for multi-scale modeling
approaches, the quantitative validation of mean-field approaches by spiking
network simulations, and an increase in reliability by usage of the same
simulation code and the same network model specifications for both model
classes. While most efficient spiking simulations rely on the communication of
discrete events, rate models require time-continuous interactions between
neurons. Exploiting the conceptual similarity to the inclusion of gap junctions
in spiking network simulations, we arrive at a reference implementation of
instantaneous and delayed interactions between rate-based models in a spiking
network simulator. The separation of rate dynamics from the general connection
and communication infrastructure ensures flexibility of the framework. We
further demonstrate the broad applicability of the framework by considering
various examples from the literature ranging from random networks to neural
field models. The study provides the prerequisite for interactions between
rate-based and spiking models in a joint simulation.


title:
Parallel adaptive integration in high-performance functional
  Renormalization Group computations

abstract:
  The conceptual framework provided by the functional Renormalization Group
(fRG) has become a formidable tool to study correlated electron systems on
lattices which, in turn, provided great insights to our understanding of
complex many-body phenomena, such as high- temperature superconductivity or
topological states of matter. In this work we present one of the latest
realizations of fRG which makes use of an adaptive numerical quadrature scheme
specifically tailored to the described fRG scheme. The final result is an
increase in performance thanks to improved parallelism and scalability.


title:
Deconfliction and Surface Generation from Bathymetry Data Using LR
  B-splines

abstract:
  A set of bathymetry point clouds acquired by different measurement techniques
at different times, having different accuracy and varying patterns of points,
are approximated by an LR B-spline surface. The aim is to represent the sea
bottom with good accuracy and at the same time reduce the data size
considerably. In this process the point clouds must be cleaned by selecting the
"best" points for surface generation. This cleaning process is called
deconfliction, and we use a rough approximation of the combined point clouds as
a reference surface to select a consistent set of points. The reference surface
is updated with the selected points to create an accurate approximation. LR
B-splines is the selected surface format due to its suitability for adaptive
refinement and approximation, and its ability to represent local detail without
a global increase in the data size of the surface


title: Rank Restricted Semidefinite Matrices and Image Closedness

abstract:
  We study the closure of the projection of the (nonconvex) cone of rank
restricted positive semidefinite matrices onto subsets of the matrix entries.
This defines the feasible sets for semidefinite completion problems with
restrictions on the ranks. Applications include conditions for low-rank
completions using the nuclear norm heuristic.


title:
Do fragmentation functions in factorization theorems correctly treat
  non-perturbative effects?

abstract:
  Current all-orders proofs of factorization of hard processes are made by
extracting the leading power behavior of Feynman graphs, i.e., by extracting
asymptotics strictly order-by-order in perturbation theory. The resulting
parton densities and fragmentation functions include non-perturbative effects.
I show how there are missing elements in the proofs; these are related to and
exemplified by string and cluster models of hadronization. The proofs rely on
large rapidity differences between different parts of graphs for the process;
but in reality large rapidity gaps are filled in


title: Generating Sentiment Lexicons for German Twitter

abstract:
  Despite a substantial progress made in developing new sentiment lexicon
generation (SLG) methods for English, the task of transferring these approaches
to other languages and domains in a sound way still remains open. In this
paper, we contribute to the solution of this problem by systematically
comparing semi-automatic translations of common English polarity lists with the
results of the original automatic SLG algorithms, which were applied directly
to German data. We evaluate these lexicons on a corpus of 7,992 manually
annotated tweets. In addition to that, we also collate the results of
dictionary- and corpus-based SLG methods in order to find out which of these
paradigms is better suited for the inherently noisy domain of social media. Our
experiments show that semi-automatic translations notably outperform automatic
systems (reaching a macro-averaged F1-score of 0.589), and that
dictionary-based techniques produce much better polarity lists as compared to
corpus-based approaches (whose best F1-scores run up to 0.479 and 0.419
respectively) even for the non-standard Twitter genre.


title: End-to-End Answer Chunk Extraction and Ranking for Reading Comprehension

abstract:
  This paper proposes dynamic chunk reader (DCR), an end-to-end neural reading
comprehension (RC) model that is able to extract and rank a set of answer
candidates from a given document to answer questions. DCR is able to predict
answers of variable lengths, whereas previous neural RC models primarily
focused on predicting single tokens or entities. DCR encodes a document and an
input question with recurrent neural networks, and then applies a word-by-word
attention mechanism to acquire question-aware representations for the document,
followed by the generation of chunk representations and a ranking module to
propose the top-ranked chunk as the answer. Experimental results show that DCR
achieves state-of-the-art exact match and F1 scores on the SQuAD dataset.


title: Smooth ergodic theory of $\mathbb{Z}^d$-actions

abstract:
  In the first part of this paper, we formulate a general setting in which to
study the ergodic theory of differentiable $\mathbb{Z}^d$-actions preserving a
Borel probability measure. This framework includes actions by
$C^{1+\text{H\"older}}$ diffeomorphisms of compact manifolds. We construct
intermediate and coarse unstable manifolds for the action and establish
controls on their local geometry.
  In the second part we consider the relationship between entropy, Lyapunov
exponents, and the geometry of conditional measures for rank-1 systems given by
a number of generalizations of the Ledrappier--Young entropy formula. In the
third part, for a smooth action of $\mathbb{Z}^d$ preserving a Borel
probability measure, we show that entropy satisfies a certain "product
structure" along coarse unstable manifolds. Moreover, given two smooth
$\mathbb{Z}^d$-actions---one of which is a measurable factor of the other---we
show that all coarse Lyapunov exponents contributing to the entropy of the
factor system are coarse Lyapunov exponents of the total system. As a
consequence, we derive an Abramov--Rohlin formula for entropy subordinated to
coarse unstable manifolds.


title:
Upper bounds on Liouville first passage percolation and Watabiki's
  prediction

abstract:
  Given a planar continuum Gaussian free field $h^{\mathcal U}$ in a domain
$\mathcal U$ with Dirichlet boundary condition and any $\delta>0$, we let
$\{h_\delta^{\mathcal U}(v): v\in \mathcal U\}$ be a real-valued smooth
Gaussian process where $h_\delta^{\mathcal U}(v)$ is the average of
$h^{\mathcal U}$ along a circle of radius $\delta$ with center $v$. For $\gamma
> 0$, we study the Liouville first passage percolation (in scale $\delta$),
i.e., the shortest path distance in $\mathcal U$ where the weight of each path
$P$ is given by $\int_P \mathrm{e}^{\gamma h_\delta^{\mathcal U}(z)} |dz|$. We
show that the distance between two typical points is $O(\delta^{c^*
\gamma^{4/3}/\log \gamma^{-1}})$ for all sufficiently small but fixed
$\gamma>0$ and some constant $c^* > 0$. In addition, we obtain similar upper
bounds on the Liouville first passage percolation for discrete Gaussian free
fields, as well as the Liouville graph distance which roughly speaking is the
minimal number of Euclidean balls with comparable Liouville quantum gravity
measure whose union contains a continuous path between two endpoints. Our
results contradict with some reasonable interpretations of Watabiki's
prediction (1993) on the random distance of Liouville quantum gravity at high
temperatures.


title: Flexible resources for quantum metrology

abstract:
  Quantum metrology offers a quadratic advantage over classical approaches to
parameter estimation problems by utilizing entanglement and nonclassicality.
However, the hurdle of actually implementing the necessary quantum probe states
and measurements, which vary drastically for different metrological scenarios,
is usually not taken into account. We show that for a wide range of tasks in
metrology, 2D cluster states (a particular family of states useful for
measurement-based quantum computation) can serve as flexible resources that
allow one to efficiently prepare any required state for sensing, and perform
appropriate (entangled) measurements using only single qubit operations.
Crucially, the overhead in the number of qubits is less than quadratic, thus
preserving the quantum scaling advantage. This is ensured by using a
compression to a logarithmically sized space that contains all relevant
information for sensing. We specifically demonstrate how our method can be used
to obtain optimal scaling for phase and frequency estimation in local
estimation problems, as well as for the Bayesian equivalents with Gaussian
priors of varying widths. Furthermore, we show that in the paradigmatic case of
local phase estimation 1D cluster states are sufficient for optimal state
preparation and measurement.


title: Numerical Facet Range Partition: Evaluation Metric and Methods

abstract:
  Faceted navigation is a very useful component in today's search engines. It
is especially useful when user has an exploratory information need or prefer
certain attribute values than others. Existing work has tried to optimize
faceted systems in many aspects, but little work has been done on optimizing
numerical facet ranges (e.g., price ranges of product). In this paper, we
introduce for the first time the research problem on numerical facet range
partition and formally frame it as an optimization problem. To enable
quantitative evaluation of a partition algorithm, we propose an evaluation
metric to be applied to search engine logs. We further propose two range
partition algorithms that computationally optimize the defined metric.
Experimental results on a two-month search log from a major e-Commerce engine
show that our proposed method can significantly outperform baseline.


title: Off the Beaten Path: Let's Replace Term-Based Retrieval with k-NN Search

abstract:
  Retrieval pipelines commonly rely on a term-based search to obtain candidate
records, which are subsequently re-ranked. Some candidates are missed by this
approach, e.g., due to a vocabulary mismatch. We address this issue by
replacing the term-based search with a generic k-NN retrieval algorithm, where
a similarity function can take into account subtle term associations. While an
exact brute-force k-NN search using this similarity function is slow, we
demonstrate that an approximate algorithm can be nearly two orders of magnitude
faster at the expense of only a small loss in accuracy. A retrieval pipeline
using an approximate k-NN search can be more effective and efficient than the
term-based pipeline. This opens up new possibilities for designing effective
retrieval pipelines. Our software (including data-generating code) and
derivative data based on the Stack Overflow collection is available online.


title: Graph Homomorphisms via Vector Colorings

abstract:
  In this paper we study the existence of homomorphisms $G\to H$ using
semidefinite programming. Specifically, we use the vector chromatic number of a
graph, defined as the smallest real number $t \ge 2$ for which there exists an
assignment of unit vectors $i\mapsto p_i$ to its vertices such that $\langle
p_i, p_j\rangle\le -1/(t-1),$ when $i\sim j$. Our approach allows to reprove,
without using the Erd\H{o}s-Ko-Rado Theorem, that for $n>2r$ the Kneser graph
$K_{n:r}$ and the $q$-Kneser graph $qK_{n:r}$ are cores, and furthermore, that
for $n/r = n'/r'$ there exists a homomorphism $K_{n:r}\to K_{n':r'}$ if and
only if $n$ divides $n'$. In terms of new applications, we show that the
even-weight component of the distance $k$-graph of the $n$-cube $H_{n,k}$ is a
core and also, that non-bipartite Taylor graphs are cores. Additionally, we
give a necessary and sufficient condition for the existence of homomorphisms
$H_{n,k}\to H_{n',k'}$ when $n/k = n'/k'$. Lastly, we show that if a
2-walk-regular graph (which is non-bipartite and not complete multipartite) has
a unique optimal vector coloring, it is a core. Based on this sufficient
condition we conducted a computational study on Ted Spence's list of strongly
regular graphs and found that at least 84% are cores.


title:
Study of the very high energy gamma-ray spectrum from the Galactic
  Center and future prospects

abstract:
  Ground-based gamma ray observations of the Galactic Center region have
revealed a high energy gamma ray source spatially coincident with the
gravitational centroid of our Galaxy. The pointlike emission detected by
H.E.S.S. exhibits an energy cut-off at about 10 TeV. We identify the parameters
of the best fit of the exponential and the super-exponential cutoff models to
the spectrum of the pointlike source and find that super-exponential one
provides a similar quality of the fit to the spectrum of the pointlike source
as the best-fit exponential cutoff model, while a dark matter interpretation
does not provide as good a fit in the whole energy range of the signal. Based
on the magnitude of the flux we derive constraints in the plane of the slope of
the density profile $\gamma$ and the critical radius, below which the density
is assumed to be constant, $r_c$. Motivated by recent results on the spectrum
and morphology from H.E.S.S. and by the possible observation of a
super-exponential cutoff, we forecast the observations of super-exponential
versus exponential cut-offs by the upcoming Cherenkov Telescope Array (CTA). We
derive a formula for $J$-factor in the small angle approximation and propose
approximate morphological constraints on the central source.


title: Nonperturbative beta function of twelve-flavor SU(3) gauge theory

abstract:
  We study the discrete beta function of SU(3) gauge theory with Nf=12 massless
fermions in the fundamental representation. Using an nHYP-smeared staggered
lattice action and an improved gradient flow running coupling $\tilde g_c^2(L)$
we determine the continuum-extrapolated discrete beta function up to $g_c^2
\approx 8.2$. We observe an IR fixed point at $g_{\star}^2 =
7.3\left(_{-2}^{+8}\right)$ in the $c = \sqrt{8t} / L = 0.25$ scheme, and
$g_{\star}^2 = 7.3\left(_{-3}^{+6}\right)$ with c=0.3, combining statistical
and systematic uncertainties in quadrature. The systematic effects we
investigate include the stability of the $(a / L) \to 0$ extrapolations, the
interpolation of $\tilde g_c^2(L)$ as a function of the bare coupling, the
improvement of the gradient flow running coupling, and the discretization of
the energy density. In an appendix we observe that the resulting systematic
errors increase dramatically upon combining smaller $c \lesssim 0.2$ with
smaller $L \leq 12$, leading to an IR fixed point at $g_{\star}^2 = 5.9(1.9)$
in the c=0.2 scheme, which resolves to $g_{\star}^2 =
6.9\left(_{-1}^{+6}\right)$ upon considering only $L \geq 16$. At the IR fixed
point we measure the leading irrelevant critical exponent to be
$\gamma_g^{\star} = 0.26(2)$, comparable to perturbative estimates.


title: Metric spaces and SDG

abstract:
  We explore how the synthetic theory of metric spaces (Busemann) can coexist
with synthetic differential geometry in the sense based on nilpotent elements
in the number line.


title:
Beam test results for the upgraded LHCb RICH optoelectronic readout
  system

abstract:
  Starting from 2018, the LHCb detector will be upgraded to operate at higher
luminosity and extend its potential for new discoveries. The Ring Imaging
Cherenkov (RICH) detectors are one of the key components for particle
identification of the LHCb detector and the upgraded specifications will
require a redesign of the optoelectronic readout chain. In the present work, we
describe the experimental setup and the results of the tests carried out with a
particle beam to assess and validate the performance of the optoelectronic
readout system.


title: Driven energy transfer between coupled modes in spin-torque oscillators

abstract:
  The mutual interaction between the different eigenmodes of a spin-torque
oscillator can lead to a large variety of physical mechanisms from mode hopping
to multi-mode generation, that usually reduce their performances as
radio-frequency devices. To tackle this issue for the future applications, we
investigate the properties of a model spin-torque oscillator that is composed
of two coupled vortices with one vortex in each of the two magnetic layers of
the oscillator. In such double-vortex system, the remarkable properties of
energy transfer between the coupled modes, one being excited by spin transfer
torque while the second one being damped, result into an alteration of the
damping parameters. As a consequence, the oscillator nonlinear behavior is
concomitantly drastically impacted. This efficient coupling mechanism, driven
mainly by the dynamic dipolar field generated by the spin transfer torque
induced motion of the vortices, gives rise to an unexpected dynamical regime of
self-resonance excitation. These results show that mode coupling can be
leveraged for controlling the synchronization process as well as the frequency
tunability of spin-torque oscillators.


title:
How CSMA/CA With Deferral Affects Performance and Dynamics in Power-Line
  Communications

abstract:
  Power-line communications (PLC) are becoming a key component in home
networking, because they provide easy and high-throughput connectivity. The
dominant MAC protocol for high data-rate PLC, the IEEE 1901, employs a CSMA/CA
mechanism similar to the backoff process of 802.11. Existing performance
evaluation studies of this protocol assume that the backoff processes of the
stations are independent (the so-called decoupling assumption). However, in
contrast to 802.11, 1901 stations can change their state after sensing the
medium busy, which is regulated by the so-called deferral counter. This
mechanism introduces strong coupling between the stations and, as a result,
makes existing analyses inaccurate. In this paper, we propose a performance
model for 1901, which does not rely on the decoupling assumption. We prove that
our model admits a unique solution for a wide range of configurations and
confirm the accuracy of the model using simulations. Our results show that we
outperform current models based on the decoupling assumption. In addition to
evaluating the performance in steady state, we further study the transient
dynamics of 1901, which is also affected by the deferral counter.


title:
Distributional fractional powers of similar operators. Applications to
  the Bessel operators

abstract:
  This paper provides a method to study the non-negativity of certain linear
operators, from other operators with similar spectral properties. If these new
operators are formally self-adjoint and non-negative, we can study the complex
powers using an appropriate locally convex space. In this case, the initial
operator also will be non-negative and we will be able to study their powers.
In particular, we have applied this method to Bessel-type operators.


title: Chaotically driven sigmoidal maps

abstract:
  We consider skew product dynamical systems
$f:\Theta\times\mathbb{R}\to\Theta\times\mathbb{R},
f(\theta,y)=(T\theta,f_\theta(y))$ with a (generalized) baker transformation
$T$ at the base and uniformly bounded increasing $C^3$ fibre maps $f_\theta$
with negative Schwarzian derivative. Under a partial hyperbolicity assumption
that ensures the existence of strong stable fibres for $f$ we prove that the
presence of these fibres restricts considerably the possible structures of
invariant measures - both topologically and measure theoretically, and that
this finally allows to provide a "thermodynamic formula" for the Hausdorff
dimension of set of those base points over which the dynamics are synchronized,
i.e. over which the global attractor consists of just one point.


title:
Out-of-equilibrium fluctuation-dissipation relations verified by the
  electrical and thermoelectrical ac-conductances in a quantum dot

abstract:
  The electrical and heat currents flowing through a quantum dot are calculated
in the presence of a time-modulated gate voltage with the help of the
out-of-equilibrium Green function technique. From the first harmonics of the
currents, we extract the electrical and thermoelectrical trans-admittances and
ac-conductances. Next, by a careful comparison of the ac-conductances with the
finite-frequency electrical and mixed electrical-heat noises, we establish the
fluctuation-dissipation relations linking these quantities, which are thus
generalized out-of-equilibrium for a quantum system. It is shown that the
electrical ac-conductance associated to the displacement current is directly
linked to the electrical noise summed over reservoirs, whereas the relation
between the thermoelectrical ac-conductance and the mixed noise contains an
additional term proportional to the energy step that the electrons must
overcome when traveling through the junction. A numerical study reveals however
that a fluctuation-dissipation relation involving a single reservoir applies
for both electrical and thermoelectrical ac-conductances when the frequency
dominates over the other characteristic energies.


title:
Magnetism of epitaxial Tb films on W(110) studied by spin-polarized
  low-energy electron microscopy

abstract:
  Thin epitaxial films of Tb metal were grown on a clean W(110) substrate in
ultra-high vacuum and studied in-situ by low-energy electron microscopy.
Annealed films present magnetic contrast in spin-polarized low-energy electron
microscopy. The energy dependence of the electron reflectivity was determined
and a maximum value of its spin asymmetry of about 1\% was measured. The
magnetization direction of the Tb films is in-plane. Upon raising the
temperature, no change in the domain distribution is observed, while the
asymmetry in the electron reflectivity decreases when approaching the critical
temperature, following a power law $ \sim (1 - T/T_C)^\beta$ with a critical
exponent $\beta$ of 0.39.


title: Perspectives on opportunities in experimental soft-matter science

abstract:
  Soft materials consist of basic units that are significantly larger than an
atom but much smaller than the overall dimensions of the sample. The label
"soft condensed matter" emphasizes that the large basic building blocks of
these materials produce low elastic moduli that govern a material's ability to
withstand deformations. Aside from softness, there are many other properties
that are also caused by the large size of the constituent building blocks. Soft
matter is dissipative, disordered, far-from-equilibrium, non-linear, thermal
and entropic, slow, observable, gravity-affected, patterned, non-local,
interfacially elastic and active. This is only a partial list of how matter
created from large component particles is distinct from "hard matter" composed
of constituents at an atomic scale. Issues inherent in soft matter raise
problems that are broadly important in diverse areas of science and require
multiple modes of attack. For example, far-from-equilibrium behavior is
confronted in biology, chemistry, geophysics, astrophysics and nuclear physics.
Similarly, issues dealing with disorder appear broadly throughout many branches
of inquiry wherever rugged landscapes are invoked. This article reviews the
discussions that occurred during a workshop held on January 30-31, 2016 in
which opportunities in soft-matter experiment were surveyed. Soft matter has
had an exciting history of discovery and continues to be a fertile ground for
future research.


title:
Stochastic economic model predictive control for Markovian switching
  systems

abstract:
  The optimization of process economics within the model predictive control
(MPC) formulation has given rise to a new control paradigm known as economic
MPC (EMPC). Several authors have discussed the closed-loop properties of
EMPC-controlled deterministic systems, however, little have uncertain systems
been studied. In this paper we propose EMPC formulations for nonlinear
Markovian switching systems which guarantee recursive feasibility, asymptotic
performance bounds and constrained mean square (MS) stability.


title:
Incommensurate short-range multipolar order parameter of phase II in
  Ce3Pd20Si6

abstract:
  The clathrate compound Ce3Pd20Si6 is a heavy-fermion metal that exhibits
magnetically hidden order at low temperatures. Reputedly, this exotic type of
magnetic ground state, known as "phase II", could be associated with the
ordering of Ce 4f quadrupolar moments. In contrast to conventional (dipolar)
order, it has vanishing Bragg intensity in zero magnetic field and, as a
result, has escaped direct observation by neutron scattering until now. Here we
report the observation of diffuse magnetic neutron scattering induced by an
application of magnetic field along either the [110] or the [001] direction
within phase II. The broad elastic magnetic signal that surrounds the (111)
structural Bragg peak can be attributed to a short-range G-type
antiferromagnetic arrangement of field-induced dipoles modulated by the
underlying multipolar order on the simple-cubic sublattice of Ce ions occupying
the 8c Wyckoff site. In addition, for magnetic fields applied along the [001]
direction, the diffuse magnetic peaks in Ce3Pd20Si6 become incommensurate,
suggesting a more complex modulated structure of the underlying multipolar
order that can be continuously tuned by a magnetic field.


title: From N-body problem to Euler equations

abstract:
  This paper contains a rigorous mathematical example of direct derivation of
the system of Euler hydrodynamic equations from Hamiltonian equations for N
point particle system as N tends to infinity. Direct means that the following
standard tools are not used in the proof: stochastic dynamics, thermodynamics,
Boltzmann kinetic equations, correlation functions approach by N. N.
Bogolyubov.


title:
The Iwasawa Main Conjecture for elliptic curves at odd supersingular
  primes

abstract:
  In this paper, we prove the Iwasawa main conjecture for elliptic curves at an
odd supersingular prime p. Some consequences are the p-parts of the leading
term formulas in the Birch and Swinnerton-Dyer conjectures for analytic rank 0
or 1.


title:
The box-crossing property for critical two-dimensional oriented
  percolation

abstract:
  We consider critical oriented Bernoulli percolation on the square lattice
$\mathbb{Z}^2$. We prove a Russo-Seymour-Welsh type result which allows us to
derive several new results concerning the critical behavior:
  - We establish that the probability that the origin is connected to distance
$n$ decays polynomially fast in $n$.
  - We prove that the critical cluster of the origin conditioned to survive to
distance $n$ has a typical width $w_n$ satisfying $\epsilon n^{2/5} < w_n <
n^{1-\epsilon}$ for some $\epsilon > 0$. The sub-linear polynomial fluctuations
contrast with the supercritical regime where $w_n$ is known to behave linearly
in $n$. It is also different from the critical picture obtained for
non-oriented Bernoulli percolation, in which the scaling limit is
non-degenerate in both directions. All our results extend to the graphical
representation of the one-dimensional contact process.


title: The Double n-Space Property for Contractible n-Manifolds

abstract:
  Motivated by a recent paper of Gabai on the Whitehead contractible
3-manifold, we investigate contractible manifolds $M^n$ which decompose or
split as $M^n = A \cup_C B$ where $A,B,C \approx \mathbb{R}^n$ or $A,B,C
\approx \mathbb{B}^n$. Of particular interest to us is the case $n=4.$ Our main
results exhibit large collections of $4$-manifolds that split in this manner.


title:
Automorphic congruences and torsion in the cohomology of a simple
  unitary Shimura variety

abstract:
  We first give a relative flexible process to construct torsion cohomology
classes for Shimura varieties of Kottwitz-Harris-Taylor type with coefficient
in a non too regular local system. We then prove that associated to each
torsion cohomology class, there exists a infinity of irreducible automorphic
representations in characteristic zero, which are pairwise non isomorphic and
weakly congruent.


title: Computed Flow and Fluorescence Over the Ocular Surface

abstract:
  Fluorescein is perhaps the most commonly used substance to visualize tear
film thickness and dynamics; better understanding of this process aids
understanding of dry eye syndrome which afflicts millions of people. We study a
mathematical model for tear film flow, evaporation, solutal transport and
fluorescence over the exposed ocular surface during the interblink. Transport
of the fluorescein ion by fluid flow in the tear film affects the intensity of
fluorescence via changes in concentration and tear film thickness. Evaporation
causes increased osmolarity and potential irritation over the ocular surface;
it also alters fluorescein concentration and thus fluorescence. Using thinning
rates from in vivo measurements together with thin film equations for flow and
transport of multiple solutes, we compute dynamic results for tear film
quantities of interest. We compare our computed intensity distributions with in
vivo observations. A number of experimental features are recovered by the
model.


title:
A Primal-Dual Homotopy Algorithm for $\ell_{1}$-Minimization with
  $\ell_{\infty}$-Constraints

abstract:
  In this paper we propose a primal-dual homotopy method for
$\ell_1$-minimization problems with infinity norm constraints in the context of
sparse reconstruction. The natural homotopy parameter is the value of the bound
for the constraints and we show that there exists a piecewise linear solution
path with finitely many break points for the primal problem and a respective
piecewise constant path for the dual problem. We show that by solving a small
linear program, one can jump to the next primal break point and then, solving
another small linear program, a new optimal dual solution is calculated which
enables the next such jump in the subsequent iteration. Using a theorem of the
alternative, we show that the method never gets stuck and indeed calculates the
whole path in a finite number of steps.
  Numerical experiments demonstrate the effectiveness of our algorithm. In many
cases, our method significantly outperforms commercial LP solvers; this is
possible since our approach employs a sequence of considerably simpler
auxiliary linear programs that can be solved efficiently with specialized
active-set strategies.


title: Quasi-Prufer extensions of rings

abstract:
  We introduce quasi-Prufer extensions of rings in order to relativize the
notion of quasi-Prufer domains and to take into account some contexts recently
introduced in the literature. We also introduce almost-Prufer ring extensions.
Characterizations and properties are given. In particular, we examine the
relationship with the finite fibers property.


title: Helicity and topology of a small region of quantum vorticity

abstract:
  We numerically study the evolution of a small turbulent region of quantised
vorticity in superfluid helium, a regime which can be realised in the
laboratory. We show that the turbulence achieves a fluctuating steady-state in
terms of dynamics (energy), geometry (length, writhing) and topology (linking).
After defining the knot spectrum, we show that, at any instant, the turbulence
consists of many unknots and few large loops of great geometrical and
topological complexity.

categories: cond-mat.other cond-mat.quant-gas physics.flu-dyn quant-ph


title: Function Driven Diffusion for Personalized Counterfactual Inference

abstract:
  We consider the problem of constructing diffusion operators high dimensional
data $X$ to address counterfactual functions $F$, such as individualized
treatment effectiveness. We propose and construct a new diffusion metric $K_F$
that captures both the local geometry of $X$ and the directions of variance of
$F$. The resulting diffusion metric is then used to define a localized
filtration of $F$ and answer counterfactual questions pointwise, particularly
in situations such as drug trials where an individual patient's outcomes cannot
be studied long term both taking and not taking a medication. We validate the
model on synthetic and real world clinical trials, and create individualized
notions of benefit from treatment.


title:
Equilibrium and non-equilibrium concentration fluctuations in a critical
  binary mixture

abstract:
  When a macroscopic concentration gradient is present across a binary mixture,
long-ranged non-equilibrium concentration fluctuations (NCF) appear as a
consequence of the coupling between the gradient and spontaneous equilibrium
velocity fluctuations. Long-ranged equilibrium concentration fluctuations (ECF)
may be also observed when the mixture is close to a critical point. Here we
study the interplay between NCF and critical ECF in a near critical mixture
aniline/cyclohexane in the presence of a vertical concentration gradient. To
this aim, we exploit a commercial optical microscope and a simple, custom-made,
temperature-controlled cell to obtain simultaneous static and dynamic
scattering information on the fluctuations. We first characterise the critical
ECF at fixed temperature $T$ above the upper critical solution temperature
$T_{c}$, in the wide temperature range $T-T_{c}\in[0.1,30]$ $^{o}$C. In this
range, we observe the expected critical scaling behaviour for both the
scattering intensity and the mass diffusion coefficient and we determine the
critical exponents $\gamma$, $\nu$ and $\eta$, which are found in agreement
with the 3D Ising values. We then study the system in the two-phase region
($T<T_{c}$). In particular, we characterise the interplay between ECF and NCF
when the mixture, initially at a temperature $T_{i}$, is rapidly brought to a
temperature $T_{f}>T_{i}$. During the transient, a vertical diffusive mass flux
is present that causes the onset of NCF, whose amplitude vanishes with time, as
the flux goes to zero. We also study the time dependence of the equilibrium
scattering intensity $I_{eq}$, of the crossover wave-vector $q_{co}$ and of the
diffusion coefficient $D$ during diffusion and find that all these quantities
exhibit an exponential relaxation enslaved to the diffusive kinetics.


title:
A density functional theory investigation of charge mobility in
  titanyl-phthalocyanines and their tailored peripherally substituted complexes

abstract:
  Titanyl-phthalocyanines catalytic ability towards oxygen reduction is
demonstrated in experimental literature. Our recent theoretical simulations
revealed electronic structure origin of catalytic ability in peripherally and
axially substituted triplet and singlet titanyl-phthalocyanines. However, the
origin of high electron transfer ability to spontaneously reduce peroxide in
chlorine substituted singlet complex and triplet state Ti(II)Pc complexes
remain elusive. Thus, we performed density functional theory calculations to
study Ti(IV)Pc and their tailored peripheral substituted complexes as
representative compounds of titanyl-phthalocyanines for charge mobilities,
reorganization energies and electronic couplings. In addition,
oxo(phthalocyaninato)titanium(IV) (TiOPc) convex and concave compounds were
investigated to benchmark the method. Based on the results, Reorganization
energies of triplet state Ti(II)Pc and their tailored peripheral substituted
complexes are compared with Ti(IV)Pc singlet complexes in order to understand
the charge mobility. Chlorine substituted complex demonstrates higher electron
hopping rate due to higher electronic coupling in comparison to other halogens.
Similarly, weak electron-donating methyl group increases the electron transport
rate. Moreover, halogen substituted Ti(II)Pc complexes elucidate lower
reorganization energies. The lowest reorganization energy is predicted for
chlorine substituted Ti(II)Pc complex, which is 0.09 eV. Therefore, higher
electronic coupling and lower reorganization energies can be considered as the
origin of higher electron transfer ability of these complexes. Furthermore,
increase electron hopping rate due to weak electron-donating substituents
provide a method to produce efficient n-channel organic field-effect
transistors with higher electron mobility.


title: Refiltering hypothesis tests to control sign error

abstract:
  A common, though not recommended statistical practice is to report confidence
intervals if and only if they exclude a null value of 0. The resulting filtered
confidence intervals generally do not have their nominal confidence level. More
worryingly, in low power settings their center points will be much farther from
zero than the true parameter is and they will frequently lie on the wrong side
of zero. Many confidence intervals are constructed using an asymptotically
Gaussian parameter estimate accompanied by a weakly consistent estimate of its
variance. In these cases, we can subject the given confidence interval(s) to a
second filtering step such that the probability of a sign error is controled.
This refiltering step retains only those confidence intervals that are
sufficiently well separated from the origin. It requires no assumptions on the
dependencies among the test statistics.


title: Meta-CTA Trading Strategies based on the Kelly Criterion

abstract:
  The influence of Commodity Trading Advisors (CTA) on the price process is
explored with the help of a simple model. CTA managers are taken to be Kelly
optimisers, which invest a fixed proportion of their assets in the risky asset
and the remainder in a riskless asset. This requires regular adjustment of the
portfolio weights as prices evolve. The CTA trading activity impacts the price
change in the form of a power law. These two rules governing investment ratios
and price impact are combined and lead through updating at fixed time intervals
to a deterministic price dynamic. For different choices of the model parameters
one gets qualitatively different dynamics. The result can be expressed as a
phase diagram. Meta-CTA strategies can be devised to exploit the predictability
inherent in the model dynamics by avoiding critical areas of the phase diagram
or by taking a contrarian position at an opportune time.


title:
Traces of random operators associated with self-affine Delone sets and
  Shubin's formula

abstract:
  We study operators defined on a Hilbert space defined by a self-affine Delone
set $\Lambda$ and show that the usual trace of a restriction of the operator to
finite-dimensional subspaces satisfies a certain $\limsup$ law controlled by
traces on a certain subalgebra. The asymptotic traces are defined through
asymptotic cycles, or $\mathbb{R}^d$-invariant distributions of a dynamical
system defined by $\Lambda$. We use this to refine Shubin's trace formula for
self-adjoint operators and show that the errors of convergence in Shubin's
formula are given by these traces.


title:
Tracking Infection Diffusion in Social Networks: Filtering Algorithms
  and Threshold Bounds

abstract:
  This paper deals with the statistical signal pro- cessing over graphs for
tracking infection diffusion in social networks. Infection (or Information)
diffusion is modeled using the Susceptible-Infected-Susceptible (SIS) model.
Mean field approximation is employed to approximate the discrete valued
infected degree distribution evolution by a deterministic ordinary differential
equation for obtaining a generative model for the infection diffusion. The
infected degree distribution is shown to follow polynomial dynamics and is
estimated using an exact non- linear Bayesian filter. We compute posterior
Cramer-Rao bounds to obtain the fundamental limits of the filter which depend
on the structure of the network. Considering the time-varying nature of the
real world networks, the relationship between the diffusion thresholds and the
degree distribution is investigated using generative models for real world
networks. In addition, we validate the efficacy of our method with the
diffusion data from a real-world online social system, Twitter. We find that
SIS model is a good fit for the information diffusion and the non-linear filter
effectively tracks the information diffusion.


title: Handle decompositions of rational balls and Casson-Gordon invariants

abstract:
  Given a rational homology sphere which bounds rational homology balls, we
investigate the complexity of these balls as measured by the number of
1-handles in a handle decomposition. We use Casson-Gordon invariants to obtain
lower bounds which also lead to lower bounds on the fusion number of ribbon
knots. We use Levine-Tristram signatures to compute these bounds and produce
explicit examples.


title: A Detailed Rubric for Motion Segmentation

abstract:
  Motion segmentation is currently an active area of research in computer
Vision. The task of comparing different methods of motion segmentation is
complicated by the fact that researchers may use subtly different definitions
of the problem. Questions such as "Which objects are moving?", "What is
background?", and "How can we use motion of the camera to segment objects,
whether they are static or moving?" are clearly related to each other, but lead
to different algorithms, and imply different versions of the ground truth. This
report has two goals. The first is to offer a precise definition of motion
segmentation so that the intent of an algorithm is as well-defined as possible.
The second is to report on new versions of three previously existing data sets
that are compatible with this definition. We hope that this more detailed
definition, and the three data sets that go with it, will allow more meaningful
comparisons of certain motion segmentation methods.


title:
Holographic QCD predictions for production and decay of pseudoscalar
  glueballs

abstract:
  The top-down holographic Witten-Sakai-Sugimoto model for low-energy QCD,
augmented by finite quark masses, has recently been found to be able to
reproduce the decay pattern of the scalar glueball candidate f0(1710) on a
quantitative level. In this Letter we show that this model predicts a narrow
pseudoscalar glueball heavier than the scalar glueball and with a very
restricted decay pattern involving eta or eta' mesons. Production should be
either in pairs or in association with eta(') mesons. We discuss the prospect
of discovery in high-energy hadron collider experiments through central
exclusive production by comparing with eta' pair production.


title:
Balance of microtubule stiffness and cortical tension determines the
  size of blood cells with marginal band across species

abstract:
  The fast blood stream of animals is associated with large shear stresses.
Consequently, blood cells have evolved a special morphology and a specific
internal architecture allowing them to maintain their integrity over several
weeks. For instance, non-mammalian red blood cells, mammalian erythroblasts and
platelets have a peripheral ring of microtubules, called the marginal band,
that flattens the overall cell morphology by pushing on the cell cortex. In
this article, we model how the shape of these cells stems from the balance
between marginal band elasticity and cortical tension. We predict that the
diameter of the cell scales with the total microtubule polymer, and verify the
predicted law across a wide range of species. Our analysis also shows that the
combination of the marginal band rigidity and cortical tension increases the
ability of the cell to withstand forces without deformation. Finally, we model
the marginal band coiling that occurs during the disc-to-sphere transition
observed for instance at the onset of blood platelet activation. We show that
when cortical tension increases faster than crosslinkers can unbind, the
marginal band will coil, whereas if the tension increases slower, the marginal
band may shorten as microtubules slide relative to each other.


title: Particle-in-cell simulations of the twisted magnetospheres of magnetars

abstract:
  The magnetospheres of magnetars are believed to be filled with
electron-positron plasma generated by electric discharge. We present a first
direct numerical experiment showing how the plasma is created in an
axisymmetric closed magnetosphere. The $e^\pm$ discharge occurs in response to
twisting of the magnetic field lines by a shear deformation of the magnetar
surface, which launches electric currents into the magnetosphere. The
simulation shows the formation of an electric "gap" with unscreened electric
field ($\mathbf{E}\cdot \mathbf{B}\neq 0$) that continually accelerates
particles along the magnetic field lines and sustains pair creation. The
accelerating voltage is self-regulated to the threshold of the $e^\pm$
discharge. It controls the rate of energy release and the lifetime of the
magnetic twist. The simulation follows the global evolution of the twisted
magnetosphere over a long time and demonstrates its gradual resistive
untwisting. A vacuum cavity forms near the star and expands, gradually erasing
magnetospheric electric currents $j$. The active j-bundle shrinks with time and
its footprints form shrinking hot spots on the magnetar surface bombarded by
the created particles.


title: Inflating Kahler Moduli and Primordial Magnetic Fields

abstract:
  We study the production of primordial magnetic fields in inflationary models
in type IIB string theory where the role of the inflaton is played by a Kahler
modulus. We consider various possibilities to realise the Standard Model
degrees of freedom in this setting and explicitly determine the time dependence
of the inflaton coupling to the Maxwell term in the models. Using this we
determine the strength and scale dependence of the magnetic fields generated
during inflation. The usual "strong coupling problem" for primordial
magnetogesis manifests itself by cycle sizes approaching the string scale, this
appears in a certain class of fibre inflation models where the standard model
is realised by wrapping D7-branes on cycles in the geometric regime.


title:
Introduction to the physics of the total cross-section at LHC: A Review
  of Data and Models

abstract:
  This review describes the development of the physics of hadronic cross
sections up to recent LHC results and cosmic ray experiments. We present here a
comprehensive review - written with a historical perspective - about total
cross-sections from medium to the highest energies explored experimentally and
studied through a variety of methods and theoretical models for over sixty
years. We begin by recalling the analytic properties of the elastic amplitude
and the theorems about the asymptotic behavior of the total cross-section. A
discussion of how proton-proton cross-sections are extracted from cosmic rays
at higher than accelerator energies and help the study of these asymptotic
limits, is presented. This is followed by a description of the advent of
particle colliders, through which high energies and unmatched experimental
precisions have been attained. Thus the measured hadronic elastic and total
cross-sections have become crucial instruments to probe the so called soft part
of QCD physics, where quarks and gluons are confined, and have led to test and
refine Regge behavior and a number of diffractive models. As the c.m. energy
increases, the total cross-section also probes the transition into hard
scattering describable with perturbative QCD, the so-called mini-jet region.
Further tests are provided by cross-section measurements of gamma p, gamma*p
and gamma* gamma* for models based on vector meson dominance, scaling limits of
virtual photons at high Q^2 and the BFKL formalism. Models interpolating from
virtual to real photons are also tested.


title: Inversion of the radiative transfer equation for polarized light

abstract:
  Since the early 1970s, inversion techniques have become the most useful tool
for inferring the magnetic, dynamic, and thermodynamic properties of the solar
atmosphere. The intrinsic model dependence makes it necessary to formulate
specific means that include the physics in a properly quantitative way. The
core of this physics lies in the radiative transfer equation (RTE), where the
properties of the atmosphere are assumed to be known while the unknowns are the
four Stokes profiles. The solution of the (differential) RTE is known as the
direct or forward problem. From an observational point of view, the problem is
rather the opposite: the data are made up of the observed Stokes profiles and
the unknowns are the solar physical quantities. Inverting the RTE is therefore
mandatory. Indeed, the formal solution of this equation can be considered an
integral equation. The solution of such an integral equation is called the
inverse problem. Inversion techniques are automated codes aimed at solving the
inverse problem.
  The foundations of inversion techniques are critically revisited with an
emphasis on making explicit the many assumptions underlying each of them. An
incremental complexity procedure is advised for the implementation in practice.
Coarse details of the profiles or coarsely sam- pled profiles should be
reproduced first with simple model atmospheres (with, for example, a few
physical quantities that are constant with optical depth). If the Stokes
profiles are well sampled and differences between synthetic and observed ones
are greater than the noise, then the inversion should proceed by using more
complex models (that is, models where physical quantities vary with depth or,
eventually, with more than one component). Significant im- provements are
expected as well from the use of new inversion techniques that take the spatial
degradation by the instruments into account.


title:
A Spatial Modeling Approach for Linguistic Object Data: Analysing
  dialect sound variations across Great Britain

abstract:
  Dialect variation is of considerable interest in linguistics and other social
sciences. However, traditionally it has been studied using proxies
(transcriptions) rather than acoustic recordings directly. We introduce novel
statistical techniques to analyse geolocalised speech recordings and to explore
the spatial variation of pronunciations continuously over the region of
interest, as opposed to traditional isoglosses, which provide a discrete
partition of the region. Data of this type require an explicit modeling of the
variation in the mean and the covariance. Usual Euclidean metrics are not
appropriate, and we therefore introduce the concept of $d$-covariance, which
allows consistent estimation both in space and at individual locations. We then
propose spatial smoothing for these objects which accounts for the possibly non
convex geometry of the domain of interest. We apply the proposed method to data
from the spoken part of the British National Corpus, deposited at the British
Library, London, and we produce maps of the dialect variation over Great
Britain. In addition, the methods allow for acoustic reconstruction across the
domain of interest, allowing researchers to listen to the statistical analysis.


title:
Competence building framework requirements for information technology
  for educational management

abstract:
  Progressive efforts have been evolving continuously for the betterment of the
services of the Information Technology for Educational Management(ITEM). These
services require data intensive and communication intensive applications. Due
to the massive growth of information, situation becomes difficult to manage
these services. Here the role of the Information and Communication Technology
(ICT) infrastructure particularly data centre with communication components
becomes important to facilitate these services. The present paper discusses the
related issues such as competent staff, appropriate ICT infrastructure, ICT
acceptance level etc. required for ITEM competence building framework
considering the earlier approach for core competences for ITEM. It this
connection, it is also necessary to consider the procurement of standard and
appropriate ICT facilities. This will help in the integration of these
facilities for the future expansion. This will also enable to create and
foresee the impact of the pairing the management with information, technology,
and education components individually and combined. These efforts will
establish a strong coupling between the ITEM activities and resource management
for effective implementation of the framework.


title: ConfocalGN : a minimalistic confocal image simulator

abstract:
  SUMMARY : We developed a user-friendly software to generate synthetic
confocal microscopy images from a ground truth specified as a 3D bitmap with
pixels of arbitrary size. The software can analyze a real confocal stack to
derivate noise parameters and will use them directly to generate new images
with similar noise characteristics. Such synthetic images can then be used to
assert the quality and robustness of an image analysis pipeline, as well as be
used to train machine-learning image analysis procedures. We illustrate the
approach with closed curves corresponding to the microtubule ring present in
blood platelet. AVAILABILITY AND IMPLEMENTATION: ConfocalGN is written in
Matlab but does not require any toolbox. The source code is distributed under
the GPL 3.0 licence on https://github.com/SergeDmi/ConfocalGN.


title:
Infinity categories with duality and hermitian multiplicative infinite
  loop space machines

abstract:
  We show that any preadditive infinity category with duality gives rise to a
direct sum hermitian K-theory spectrum. This assignment is lax symmetric
monoidal, thereby producing E-infinity ring spectra from preadditive symmetric
monoidal infinity categories with duality. To have examples of preadditive
symmetric monoidal infinity categories with duality we show that any
preadditive symmetric monoidal infinity category, in which every object admits
a dual, carries a canonical duality. Moreover we classify and twist the
dualities in various ways and apply our definitions for example to finitely
generated projective modules over E-infinity ring spectra.


title: A Grothendieck-Witt space for stable infinity categories with duality

abstract:
  We construct a Grothendieck-Witt space for any stable infinity category with
duality. If we apply our construction to perfect complexes over a commutative
ring in which 2 is invertible we recover the classical Grothendieck-Witt space.
Our Grothendieck-Witt space is a grouplike E-infinity space which is part of a
genuine C_2-spectrum, the connective real K-theory spectrum.


title: Isotope effect in superconducting n-doped SrTiO$_3$

abstract:
  We report the influence on the superconducting critical temperature $T_c$ in
doped SrTiO$_3$ of the substitution of the natural $^{16}$O atoms by the
heavier isotope $^{18}$O. We observe that for a wide range of doping this
substitution causes a strong ($\sim 50 \%$) enhancement of $T_c$. Also the
magnetic critical field $H_{c2}$ is increased by a factor $\sim 2$. Such a
strong impact on $T_c$ and $H_{c2}$, with a sign opposite to conventional
superconductors, is unprecedented. The observed effect could be the consequence
of strong coupling of the doped electrons to lattice vibrations (phonons), a
notion which finds support in numerous optical and photo-emission studies. The
unusually large size of the observed isotope effect supports a recent model for
superconductivity in these materials based on strong coupling to the
ferroelectric soft modes of SrTiO$_{3}$.


title: A quest for new physics inside the neutron

abstract:
  The lecture presents an overview of the quest for the new physics in low
energy neutron phenomena. In addition to the traditional topics the quantum
damping of $n$ $\bar{n}$ oscillations is discussed.


title:
Multi-particle collision simulations of 2D one-component plasmas:
  anomalous transport and dimensional crossovers

abstract:
  By means of hybrid multi-particle collsion--particle-in-cell (MPC-PIC)
simulations we study the dynamical scaling of energy and density correlations
at equilibrium in moderately coupled 2D and quasi 1D plasmas. We find that the
predictions of Nonlinear Fluctuating Hydrodynamics for the structure factors of
density and energy fluctuations in 1D systems with three global conservation
laws hold true also for two dimensional systems that are more extended along
one of the two spatial dimensions. Moreover, from the analysis of the
equilibrium energy correlators and density structure factors of both 1D and 2D
neutral plasmas, we find that neglecting the contribution of the fluctuations
of the vanishing self-consistent electrostatic fields overestimates the
interval of frequencies over which the anomalous transport is observed. Such
violations of the expected scaling in the currents correlation are found in
different regimes, hindering the observation of the asymptotic scaling
predicted by the theory.


title:
Bi-modal First Impressions Recognition using Temporally Ordered Deep
  Audio and Stochastic Visual Features

abstract:
  We propose a novel approach for First Impressions Recognition in terms of the
Big Five personality-traits from short videos. The Big Five personality traits
is a model to describe human personality using five broad categories:
Extraversion, Agreeableness, Conscientiousness, Neuroticism and Openness. We
train two bi-modal end-to-end deep neural network architectures using
temporally ordered audio and novel stochastic visual features from few frames,
without over-fitting. We empirically show that the trained models perform
exceptionally well, even after training from a small sub-portions of inputs.
Our method is evaluated in ChaLearn LAP 2016 Apparent Personality Analysis
(APA) competition using ChaLearn LAP APA2016 dataset and achieved excellent
performance.


title:
How gauge covariance of the fermion and boson propagators in QED
  constrain the effective fermion-boson vertex

abstract:
  We derive the gauge covariance requirement imposed on the QED fermion-photon
three-point function within the framework of a spectral representation for
fermion propagators. When satisfied, such requirement ensures solutions to the
fermion propagator Schwinger-Dyson equation (SDE) in any covariant gauge with
arbitrary numbers of spacetime dimensions to be consistent with the
Landau-Khalatnikov-Fradkin transformation (LKFT). The general result has been
verified by the special cases of three and four dimensions. Additionally, we
present the condition that ensures the vacuum polarization is independent of
the gauge parameter. As an illustration, we show how the Gauge Technique
dimensionally regularized in 4D does not satisfy the covariance requirement.


title: The Paths to Choreography Extraction

abstract:
  Choreographies are global descriptions of interactions among concurrent
components, most notably used in the settings of verification (e.g., Multiparty
Session Types) and synthesis of correct-by-construction software (Choreographic
Programming). They require a top-down approach: programmers first write
choreographies, and then use them to verify or synthesize their programs.
However, most existing software does not come with choreographies yet, which
prevents their application.
  To attack this problem, we propose a novel methodology (called choreography
extraction) that, given a set of programs or protocol specifications,
automatically constructs a choreography that describes their behavior. The key
to our extraction is identifying a set of paths in a graph that represents the
symbolic execution of the programs of interest. Our method improves on previous
work in several directions: we can now deal with programs that are equipped
with a state and internal computation capabilities; time complexity is
dramatically better; we capture programs that are correct but not necessarily
synchronizable, i.e., they work because they exploit asynchronous
communication.


title: Cosmological constraints on exotic injection of electromagnetic energy

abstract:
  We compute cosmic microwave background (CMB) anisotropy constraints on exotic
forms of energy injection in electromagnetic (e.m.) channels over a large range
of timescales. These constraints are very powerful around or just after
recombination, although CMB keeps some sensitivity e.g. to decaying species
with lifetimes as long as $10^{25}\,$s. We review here complementary with CMB
spectral distortions and primordial nucleosynthesis bounds, which dominate at
earlier timescales. For the first time, we describe the effects of the e.m.
energy injection on the CMB power spectra as a function of the injection epoch,
using the lifetime of a decaying particle as proxy. We identify a suitable
on-the-spot approximation. Our results are of interest not only for early
universe relics constituting (a fraction of) the dark matter, but also for
other exotic injection of e.m. radiation. For illustration, we apply our
formalism to: i) Primordial black holes of mass $\in [10^{13.5},10^{16.8}]$ g,
showing that the constraints are comparable to the ones obtained from gamma-ray
background studies and even dominate below $\sim 10^{14}$g. ii) To a peculiar
mass-mixing range in the sterile neutrino parameter space, complementary to
other astrophysical and laboratory probes. iii) Finally, we provide a first
estimate of the room for improvement left for forthcoming 21 cm experiments,
comparing it with the reach of proposed CMB spectral distortion (PiXiE) and CMB
angular power spectrum (CORE) missions. We show that the best and most
realistic opportunity to look for this signal (or to improve over current
constraints) in the 21 cm probe is to focus on the Cosmic Dawn epoch,
$15\lesssim z\lesssim30$, where the qualitatively unambiguous signature of a
spectrum in emission can be expected for models that evade all current
constraints.


title: Microscopic densities and Fock-Sobolev spaces

abstract:
  We study two-dimensional eigenvalue ensembles close to certain types of
singular points in the bulk of the droplet. We prove existence of a microscopic
density which quickly approaches the classical equilibrium density, as the
distance from the singularity increases beyond the microscopic scale. As a
consequence we obtain asymptotics for the Bergman function of certain
Fock-Sobolev spaces of entire functions.


title: Benchmarking the Multi-dimensional Stellar Implicit Code MUSIC

abstract:
  We present the results of a numerical benchmark study for the
MUlti-dimensional Stellar Implicit Code (MUSIC) based on widely applicable two-
and three-dimensional compressible hydrodynamics problems relevant to stellar
interiors. MUSIC is an implicit large eddy simulation code that uses implicit
time integration, implemented as a Jacobian-free Newton Krylov method. A
physics based preconditioning technique which can be adjusted to target varying
physics is used to improve the performance of the solver. The problems used for
this benchmark study include the Rayleigh-Taylor and Kelvin-Helmholtz
instabilities, and the decay of the Taylor-Green vortex. Additionally we show a
test of hydrostatic equilibrium, in a stellar environment which is dominated by
radiative effects. In this setting the flexibility of the preconditioning
technique is demonstrated. This work aims to bridge the gap between the
hydrodynamic test problems typically used during development of numerical
methods and the complex flows of stellar interiors. A series of
multi-dimensional tests are performed and analysed. Each of these test cases is
analysed with a simple, scalar diagnostic, with the aim of enabling direct code
comparisons. As the tests performed do not have analytic solutions we verify
MUSIC by comparing to established codes including ATHENA and the PENCIL code.
MUSIC is able to both reproduce behaviour from established and widely-used
codes as well as results expected from theoretical predictions. This
benchmarking study concludes a series of papers describing the development of
the MUSIC code and provides confidence in the future applications.


title: Chromium analogues of Iron-based superconductors

abstract:
  We theoretically investigate the $d^4$ (Cr$^{2+}$) compound BaCr$_2$As$_2$
and show that, despite non-negligible differences in the electronic structure,
its many-body physics mirrors that of BaFe$_2$As$_2$, which has instead a $d^6$
(Fe$^{2+}$) configuration. This reflects a symmetry of the electron correlation
effects around the half-filled $d^5$ Mott insulating state. The experimentally
known metallic antiferromagnetic phase is correctly modeled by dynamical
mean-field theory, and for realistic values of the interaction it shows a
moderate mass enhancement of order $\sim$2. This value decreases if the ordered
moment grows as a result of a stronger interaction. The antiferromagnetic phase
diagram for this $d^4$ shows similarities with that calculated for the $d^6$
systems. Correspondingly, in the paramagnetic phase the influence of the
half-filled Mott insulator shows up as a crossover from a weakly correlated to
an orbitally differentiated "Hund's metal" phase which reflects an analogous
phenomenon in $d^6$ iron compounds including a strong enhancement of the
compressibility in a zone just inside the frontier between the normal and the
Hund's metal. The experimental evidence and our theoretical description place
BaCr$_2$As$_2$ at interaction strength slightly below the crossover which
implies that negative pressures and/or electron doping (e.g. Cr $\rightarrow$
Mn,Fe or Ba $\rightarrow$ Sc,Y,La) might strongly enhance the compressibility,
thereby possibly inducing a pairing instability in this non-superconducting
compound.


title: Phenomenological predictions of 3+1d anisotropic hydrodynamics

abstract:
  We make phenomenological predictions for particle spectra and elliptic flow
in heavy-ion collisions using 3+1d anisotropic hydrodynamics (aHydro) including
the effects of both shear and bulk viscosities. The dynamical equations
necessary are derived by taking moments of the Boltzmann equation allowing for
three distinct (diagonal) momentum-space anisotropy parameters. The formulation
is based on relaxation-time approximation for the collisional kernel and a
lattice-QCD-based equation of state. Evolving the system to late times, we
calculate particle production using THERMINATOR 2, modified to account for an
ellipsoidal distribution function. We obtain particle spectra for different
particle species such as pions, kaons, and protons, and elliptic flow $v_2$ as
a function of centrality, transverse momentum, and rapidity. In our model, we
have four free parameters, i.e. freeze-out temperature, initial central energy
density, initial momentum-space anisotropies, and shear viscosity to entropy
density ratio. Using a multidimensional fit to LHC experimental data, we make a
preliminary extraction of these parameters. We find reasonable agreement
between 3+1d aHydro and available experimental data for $\eta/s\sim 0.23$.


title:
On Regulatory and Organizational Constraints in Visualization Design and
  Evaluation

abstract:
  Problem-based visualization research provides explicit guidance toward
identifying and designing for the needs of users, but absent is more concrete
guidance toward factors external to a user's needs that also have implications
for visualization design and evaluation. This lack of more explicit guidance
can leave visualization researchers and practitioners vulnerable to unforeseen
constraints beyond the user's needs that can affect the validity of
evaluations, or even lead to the premature termination of a project. Here we
explore two types of external constraints in depth, regulatory and
organizational constraints, and describe how these constraints impact
visualization design and evaluation. By borrowing from techniques in software
development, project management, and visualization research we recommend
strategies for identifying, mitigating, and evaluating these external
constraints through a design study methodology. Finally, we present an
application of those recommendations in a healthcare case study. We argue that
by explicitly incorporating external constraints into visualization design and
evaluation, researchers and practitioners can improve the utility and validity
of their visualization solution and improve the likelihood of successful
collaborations with industries where external constraints are more present.


title: Hydropower optimization: an industrial approach

abstract:
  Nowadays hydroelectric energy is one of the best energy sources: it is
cleaner, safer and more programmable than other sources. For this reason, its
manage could not be done in an approssimative way, but advance mathematical
models must be use. In this article we consider an overview of the problem: we
introduce the problem, then we show its simplest but quite exaustive
mathematical formulation and in the end we produce numerical results under the
ipothesis that all input are deterministic.


title: Truncation In Unions of Hahn Fields with a Derivation

abstract:
  Truncation in Generalized Series fields is a robust notion, in the sense that
it is preserved under various algebraic and some transcendental extensions. In
this paper, we study conditions that ensure that a truncation closed set
extends naturally to a truncation closed differential ring, and a truncation
closed differential field has a truncation closed Liouville closure. In
particular, we introduce the Notion of IL-closedness in Unions of Hahn fields
in order to determine that this condition is sufficient to preserve truncation
in those two settings for constructions such as the field of
logarithmic-exponential transseries.


title:
Field measurements demonstrate distinct initiation and cessation
  thresholds governing aeolian sediment transport flux

abstract:
  Wind-blown sand and dust models depend sensitively on the threshold wind
stress. However, laboratory and numerical experiments suggest the coexistence
of distinct "fluid" and "impact" thresholds for the initiation and cessation of
aeolian saltation, respectively. Because aeolian transport models typically use
only the fluid threshold, existence of a separate lower impact threshold
complicates the prediction of wind-driven transport. Here, we derive the first
field-based estimates of distinct fluid and impact thresholds from
high-frequency saltation measurements at three field sites. Our measurements
show that, when saltation is mostly inactive, its instantaneous occurrence is
governed primarily by wind exceedance of the fluid threshold. As saltation
activity increases, so too does the relative importance of the impact
threshold, until it dominates under near-continuous transport conditions.
Although both thresholds are thus important for high-frequency saltation
prediction, we find that the time-averaged saltation flux is primarily governed
by impact threshold.


title:
Optimization for Large-Scale Machine Learning with Distributed Features
  and Observations

abstract:
  As the size of modern data sets exceeds the disk and memory capacities of a
single computer, machine learning practitioners have resorted to parallel and
distributed computing. Given that optimization is one of the pillars of machine
learning and predictive modeling, distributed optimization methods have
recently garnered ample attention in the literature. Although previous research
has mostly focused on settings where either the observations, or features of
the problem at hand are stored in distributed fashion, the situation where both
are partitioned across the nodes of a computer cluster (doubly distributed) has
barely been studied. In this work we propose two doubly distributed
optimization algorithms. The first one falls under the umbrella of distributed
dual coordinate ascent methods, while the second one belongs to the class of
stochastic gradient/coordinate descent hybrid methods. We conduct numerical
experiments in Spark using real-world and simulated data sets and study the
scaling properties of our methods. Our empirical evaluation of the proposed
algorithms demonstrates the out-performance of a block distributed ADMM method,
which, to the best of our knowledge is the only other existing doubly
distributed optimization algorithm.


title: A GPU-Based Genetic Algorithm for the P-Median Problem

abstract:
  The p-median problem is a well-known NP-hard problem. Many heuristics have
been proposed in the literature for this problem. In this paper, we exploit a
GPGPU parallel computing platform to present a new genetic algorithm
implemented in Cuda and based on a Pseudo Boolean formulation of the p-median
problem. We have tested the effectiveness of our algorithm using a Tesla K40
(2880 Cuda cores) on 290 different benchmark instances obtained from
OR-Library, discrete location problems benchmark library, and benchmarks
introduced in recent publications. The algorithm succeeded in finding optimal
solutions for all instances except for two OR-library instances, namely pmed30
and pmed40, where better than 99.9\% approximations were obtained.


title: Regularized Laplacian determinants of self-similar fractals

abstract:
  We study the spectral zeta functions of the Laplacian on fractal sets which
are locally self-similar fractafolds, in the sense of Strichartz. These
functions are known to meromorphically extend to the entire complex plane, and
the locations of their poles, sometimes referred to as complex dimensions, are
of special interest. We give examples of self-similar sets such that their
complex dimensions are not on the imaginary axis, which allows us to interpret
their Laplacian determinant as the regularized product of their eigenvalues. We
then investigate a connection between the logarithm of the determinant of the
discrete graph Laplacian and the regularized one.


title:
High Performance Inverted Organic Photovoltaics Without Hole Selective
  Contact

abstract:
  A detailed investigation of the functionality of inverted organic
photovoltaics (OPVs) using bare Ag contacts as top electrode is presented. The
inverted OPVs without hole transporting layer (HTL) exhibit a significant gain
in hole carrier selectivity and power conversion efficiency (PCE) after
exposure in ambient conditions. Inverted OPVs comprised of
ITO/ZnO/poly(3-hexylthiophene-2,5-diyl):phenyl-C61-butyric acid methyl ester
(P3HT:PCBM)/Ag demonstrate over 3.5% power conversion efficiency only if the
devices are exposed in air for over 4 days. As concluded through a series of
measurements, the oxygen presence is essential to obtain fully operational
solar cell devices without HTL. Moreover, accelerated stability tests under
damp heat conditions (RH=85% and T=65oC) performed to non-encapsulated OPVs
demonstrate that HTL-free inverted OPVs exhibit comparable stability to the
reference inverted OPVs. Importantly, it is shown that bare Ag top electrodes
can be efficiently used in inverted OPVs using various high performance
polymer:fullerene bulk heterojunction material systems demonstrating 6.5% power
conversion efficiencies.


title:
The Case for Temporal Transparency: Detecting Policy Change Events in
  Black-Box Decision Making Systems

abstract:
  Bringing transparency to black-box decision making systems (DMS) has been a
topic of increasing research interest in recent years. Traditional active and
passive approaches to make these systems transparent are often limited by
scalability and/or feasibility issues. In this paper, we propose a new notion
of black-box DMS transparency, named, temporal transparency, whose goal is to
detect if/when the DMS policy changes over time, and is mostly invariant to the
drawbacks of traditional approaches. We map our notion of temporal transparency
to time series changepoint detection methods, and develop a framework to detect
policy changes in real-world DMS's. Experiments on New York
Stop-question-and-frisk dataset reveal a number of publicly announced and
unannounced policy changes, highlighting the utility of our framework.


title:
Experimentally simulating the dynamics of quantum light and matter at
  ultrastrong coupling

abstract:
  The quantum Rabi model describing the fundamental interaction between light
and matter is a cornerstone of quantum physics. It predicts exotic phenomena
like quantum phase transitions and ground-state entanglement in the
ultrastrong-coupling (USC) regime, where coupling strengths are comparable to
subsystem energies. Despite progress in many experimental platforms, the few
experiments reaching USC have been limited to spectroscopy: demonstrating USC
dynamics remains an outstanding challenge. Here, we employ a circuit QED chip
with moderate coupling between a resonator and transmon qubit to realise
accurate digital quantum simulation of USC dynamics. We advance the state of
the art in solid-state digital quantum simulation by using up to 90
second-order Trotter steps and probing both subsystems in a combined Hilbert
space dimension $\sim80$, demonstrating the Schr\"odinger-cat like entanglement
and build-up of large photon numbers characteristic of deep USC. This work
opens the door to exploring extreme USC regimes, quantum phase transitions and
many-body effects in the Dicke model.


title:
The fragmentation and stability of hierarchical structure in Serpens
  South

abstract:
  Filamentary structures are ubiquitous in molecular clouds, and have been
recently argued to play an important role in regulating the size and mass of
embedded clumps through fragmentation and mass accretion. Here, we reveal the
dynamical state and fragmentation of filamentary molecular gas associated with
the Serpens South protocluster through analysis of wide (~4 x 4 pc)
observations of NH3 (1,1) and (2,2) inversion transitions with the Green Bank
Telescope. Detailed modeling of the NH3 lines reveals that the kinematics of
the cluster and surrounding filaments are complex. We identify hierarchical
structure using a dendrogram analysis of the NH3 emission. The distance between
neighbour structures that are embedded within the same parent structure is
generally greater than expected from a spherical Jeans analysis, and is in
better agreement with cylindrical fragmentation models. The NH3 line width-size
relation is flat, and average gas motions are sub- or trans-sonic over all
physical scales observed. Subsonic regions extend far beyond the typical 0.1 pc
scale previously identified in star-forming cores. As a result, we find a
strong trend of decreasing virial parameter with increasing structure mass in
Serpens South. Extremely low virial parameters on the largest scales probed by
our data suggest that the previously observed, ordered magnetic field is
insufficient to support the region against collapse, in agreement with large
radial infall motions previously measured toward some of the filaments. A more
complex magnetic field configuration in the dense gas, however, may be able to
support the filaments.


title: Vital Signs: Seismology of ocean worlds

abstract:
  Ice-covered ocean worlds possess diverse energy sources and associated
mechanisms that are capable of driving significant seismic activity, but to
date no measurements of their seismic activity have been obtained. Such
investigations could probe their transport properties and radial structures,
with possibilities for locating and characterizing trapped liquids that may
host life and yielding critical constraints on redox fluxes, and thus on
habitability. Modeling efforts have examined seismic sources from tectonic
fracturing and impacts. Here, we describe other possible seismic sources, their
associations with science questions constraining habitability, and the
feasibility of implementing such investigations. We argue, by analogy with the
Moon, that detectable seismic activity on tidally flexed ocean worlds should
occur frequently. Their ices fracture more easily than rocks, and dissipate
more tidal energy than the <1 GW of the Moon and Mars. Icy ocean worlds also
should create less thermal noise for a due to their greater distance and
consequently smaller diurnal temperature variations. They also lack substantial
atmospheres (except in the case of Titan) that would create additional noise.
Thus, seismic experiments could be less complex and less susceptible to noise
than prior or planned planetary seismology investigations of the Moon or Mars.


title: Dark matter from one-flavor SU(2) gauge theory

abstract:
  SU(2) gauge theory with a single fermion in the fundamental representation is
a minimal non-Abelian candidate for the dark matter sector, which is presently
missing from the standard model. Having only a single flavor provides a natural
mechanism for stabilizing dark matter on cosmological timescales. Preliminary
lattice results are presented and discussed in the context of dark matter
phenomenology.


title: The Muon g-2 Experiment Overview and Status as of June 2016

abstract:
  The Muon g-2 Experiment at Fermilab will measure the anomalous magnetic
moment of the muon to a precision of 140 parts per billion, which is a factor
of four improvement over the previous E821 measurement at Brookhaven. The
experiment will also extend the search for the electric dipole moment (EDM) of
the muon by approximately two orders of magnitude, with a sensitivity down to
$10^{-21}$ e.cm. Both of these measurements are made by combining a precise
measurement of the 1.45T storage ring magnetic field with an analysis of the
modulation of the decay rate of higher-energy positrons (from anti-muons),
recorded by 24 calorimeters and 3 straw tracking detectors. The recent progress
in the alignment of the electrostatic quadrapole plates and the trolley rails
inside the vacuum chambers, and in establishing the uniform storage ring
magnetic field will be described.


title: Chiral Extrapolation of the Sigma Resonance

abstract:
  We analyze recent results on isoscalar $\pi\pi$ scattering from a $N_f=2+1$
lattice simulation by the HadronSpectrum collaboration by re-summing the
two-flavor chiral scattering amplitude of the next-to-leading order in the
so-called inverse amplitude method. The lattice data can be well extrapolated
to the physical pion mass. We also find that both $I=0$ and $I=1$ lattice data
can be described simultaneously for pion masses up to $M_{\pi}=236$ MeV.


title:
Langmuir wave filamentation in the kinetic regime. II. Weak and Strong
  Pumping of Nonlinear Electron Plasma Waves as the Route to Filamentation

abstract:
  We consider two kinds of pumped Langmuir waves (LWs) in the kinetic regime,
$k\lambda_D\gtrsim0.2,$ where $k$ is the LW wavenumber and $\lambda_D$ is the
Debye length. They are driven to finite amplitude by a coherent external
potential whose amplitude is either weak or strong. These dynamically prepared
nonlinear LWs develop a transverse (filamentation) instability whose nonlinear
evolution destroys the LW's transverse coherence. Instability growth rates in
the weakly pumped regime are the same as those of BGK modes considered in Part
I, while strongly pumped LWs have higher filamentation grow rates.


title:
Gas expulsion vs gas retention: what process dominates in young massive
  clusters?

abstract:
  The ability of young stellar clusters to expel or retain the gas left over
after a first episode of star formation is a central issue in all models aiming
to explain multiple stellar populations and the peculiar light element
abundance patterns in globular clusters. Recent attempts to detect the gas left
over from star formation in present day clusters with masses similar to those
of globular clusters did not reveal a significant amount of gas in the majority
of them, which strongly restricts the scenarios of multiple stellar population
formation. Here the conditions required to retain the gas left over from star
formation within the natal star forming cloud are revised. It is shown that the
usually accepted concept regarding the thermalization of the star cluster
kinetic energy due to nearby stellar winds and SNe ejecta collisions must be
taken with care in the case of very compact and dense star forming clouds where
three star formation regimes are possible if one considers different star
formation efficiencies and mass concentrations. The three possible regimes are
well separated in the half-mass radius and in the natal gas central density vs
pre-stellar cloud mass parameter space. The two gas free clusters in the
Antennae galaxies and the gas rich cluster with a similar mass and age in the
galaxy NGC 5253 appear in different zones in these diagrams. The critical lines
obtained for clusters with a solar and a primordial gas metallicity are
compared.


title: Holder Regularity for Nondivergence nonlocal parabolic equations

abstract:
  This paper proves H\"older continuity of viscosity solutions to certain
nonlocal parabolic equations that involve a generalized fractional time
derivative of Marchaud or Caputo type. As a necessary and preliminary result,
this paper first shows that viscosity solutions to certain nonlinear ordinary
differential equations involving the generalized fractional time derivative are
H\"older continuous.


title: Adjoint SU(2) with Four Fermion Interactions

abstract:
  Four fermion interactions appear in many models of Beyond Standard Model
physics. In Technicolour and composite Higgs models Standard Model fermion
masses can be generated by four fermion terms. They are also expected to modify
the dynamics of the new strongly interacting sector. In particular in
technicolour models it has been suggested that they can be used to break
infrared conformality and produce a walking theory with a large mass anomalous
dimension. We study the SU(2) gauge theory with 2 adjoint fermions and a
chirally symmetric four fermion term. We demonstrate chiral symmetry breaking
at large four fermion coupling and study the phase diagram of the model.


title: Spin Topological Field Theory and Fermionic Matrix Product States

abstract:
  We study state-sum constructions of G-equivariant spin-TQFTs and their
relationship to Matrix Product States. We show that in the Neveu-Schwarz,
Ramond, and twisted sectors, the states of the theory are generalized Matrix
Product States. We apply our results to revisit the classification of fermionic
Short-Range-Entangled phases with a unitary symmetry G and determine the group
law on the set of such phases. Interesting subtleties appear when the total
symmetry group is a nontrivial extension of G by fermion parity.


title: Burghelea conjecture and asymptotic dimension of groups

abstract:
  We review the Burghelea conjecture, which constitutes a full computation of
the periodic cyclic homology of complex group rings, and its relation to the
algebraic Baum-Connes conjecture. The Burghelea conjecture implies the Bass
conjecture.
  We state two conjectures about groups of finite asymptotic dimension, which
together imply the Burghelea conjecture for such groups. We prove both
conjectures for many classes of groups.
  It is known that the Burghelea conjecture does not hold for all groups,
although no finitely presentable counter-example was known. We construct a
finitely presentable (even type $F_\infty$) counter-example based on Thompson's
group F. We construct as well a finitely generated counter-example with finite
decomposition complexity.


title: The radical of an n-absorbing ideal

abstract:
  In this note we show that in a commutative ring $R$ with unity, for any $n >
0$, if $I$ is an $n$-absorbing ideal of $R$, then $(\sqrt{I})^{n} \subseteq I$.


title: Optimal retirement income tontines

abstract:
  Tontines were once a popular type of mortality-linked investment pool. They
promised enormous rewards to the last survivors at the expense of those died
early. And, while this design appealed to the gambling instinc}, it is a
suboptimal way to generate retirement income. Indeed, actuarially-fair life
annuities making constant payments -- where the insurance company is exposed to
longevity risk -- induce greater lifetime utility. However, tontines do not
have to be structured the historical way, i.e. with a constant cash flow shared
amongst a shrinking group of survivors. Moreover, insurance companies do not
sell actuarially-fair life annuities, in part due to aggregate longevity risk.
  We derive the tontine structure that maximizes lifetime utility. Technically
speaking we solve the Euler-Lagrange equation and examine its sensitivity to
(i.) the size of the tontine pool $n$, and (ii.) individual longevity risk
aversion $\gamma$. We examine how the optimal tontine varies with $\gamma$ and
$n$, and prove some qualitative theorems about the optimal payout.
Interestingly, Lorenzo de Tonti's original structure is optimal in the limit as
longevity risk aversion $\gamma \to \infty$. We define the natural tontine as
the function for which the payout declines in exact proportion to the survival
probabilities, which we show is near-optimal for all $\gamma$ and $n$. We
conclude by comparing the utility of optimal tontines to the utility of loaded
life annuities under reasonable demographic and economic conditions and find
that the life annuity's advantage over the optimal tontine is minimal.
  In sum, this paper's contribution is to (i.) rekindle a discussion about a
retirement income product that has been long neglected, and (ii.) leverage
economic theory as well as tools from mathematical finance to design the next
generation of tontine annuities.


title:
Bounded Model Checking of State-Space Digital Systems: The Impact of
  Finite Word-Length Effects on the Implementation of Fixed-Point Digital
  Controllers Based on State-Space Modeling

abstract:
  The extensive use of digital controllers demands a growing effort to prevent
design errors that appear due to finite-word length (FWL) effects. However,
there is still a gap, regarding verification tools and methodologies to check
implementation aspects of control systems. Thus, the present paper describes an
approach, which employs bounded model checking (BMC) techniques, to verify
fixed-point digital controllers represented by state-space equations. The
experimental results demonstrate the sensitivity of such systems to FWL effects
and the effectiveness of the proposed approach to detect them. To the best of
my knowledge, this is the first contribution tackling formal verification
through BMC of fixed-point state-space digital controllers.