title: Smooth duality and co-contra correspondence

abstract:
  The aim of this paper is to explain how to get a complex of smooth
representations out of the dual vector space to a smooth representation of a
p-adic Lie group, in natural characteristic. The construction does not depend
on any finiteness/admissibility assumptions. Imposing such an assumption, one
obtains an involutive duality on the derived category of complexes of smooth
modules with admissible cohomology modules. The paper can serve as an
introduction to the results about representations of locally profinite groups
contained in the author's monograph on semi-infinite homological algebra
arXiv:0708.3398.


title:
Lubricated wrinkles: imposed constraints affect the dynamics of wrinkle
  coarsening

abstract:
  We study the dynamic coarsening of wrinkles in an elastic sheet that is
compressed while lying on a thin layer of viscous liquid. When the ends of the
sheet are instantaneously brought together by a small distance, viscous
resistance initially prevents the sheet from adopting a globally buckled shape.
Instead, the sheet accommodates the compression by wrinkling. Previous scaling
arguments suggested that a balance between the sheet's bending stiffness and
viscous effects lead to a wrinkle wavelength $\lambda$ that increases with time
$t$ according to $\lambda\propto t^{1/6}$. We show that taking proper account
of the compression constraint leads to a logarithmic correction of this result,
$\lambda\propto (t/\log t)^{1/6}$. This correction is significant over
experimentally observable time spans, and leads us to reassess previously
published experimental data.


title: A method to deconvolve stellar rotational velocities II

abstract:
  Knowing the distribution of stellar rotational velocities is essential for
the understanding stellar evolution. Because we measure the projected
rotational speed vsini, we need to solve an ill-posed problem given by a
Fredholm integral of the first kind to recover the true rotational velocity
distribution. After discretization of the Fredholm integral, we apply the
Tikhonov regularization method to obtain directly the probability distribution
function for stellar rotational velocities. We propose a simple and
straightforward procedure to determine the Tikhonov parameter. We applied Monte
Carlo simulations to prove that Tikhonov method is a consistent estimator and
asymptotically unbiased. This method is applied to a sample of cluster stars.
We obtain confidences intervals using bootstrap method. Our results are in good
agreement with the one obtained using the Lucy method, in recovering the
probability density distribution of rotational velocities. Furthermore, Lucy
estimation lies inside our confidence interval. Tikhonov regularization is a
very robust method that deconvolve the rotational velocity probability density
function from a sample of vsini data straightforward without needing any
convergence criteria.


title:
When to make a step? Tackling the timing problem in multi-contact
  locomotion by TOPP-MPC

abstract:
  We present a model predictive controller (MPC) for multi-contact locomotion
where predictive optimizations are realized by time-optimal path
parameterization (TOPP). A key feature of this solution is that, contrary to
existing planners where step timings are provided as inputs, here the timing
between contact switches is computed as output of a fast nonlinear
optimization. This is particularly appealing to multi-contact locomotion, where
proper timings depend on terrain topology and suitable heuristics are unknown.
We show how to formulate legged locomotion as a TOPP problem and demonstrate
the behavior of the resulting TOPP-MPC controller in simulations with a model
of the HRP-4 humanoid robot.


title:
Unified formulation and analysis of mixed and primal discontinuous
  skeletal methods on polytopal meshes

abstract:
  We propose in this work a unified formulation of mixed and primal
discretization methods on polyhedral meshes hinging on globally coupled degrees
of freedom that are discontinuous polynomials on the mesh skeleton. To
emphasize this feature, these methods are referred to here as discontinuous
skeletal. As a starting point, we define two families of discretizations
corresponding, respectively, to mixed and primal formulations of discontinuous
skeletal methods. Each family is uniquely identified by prescribing three
polynomial degrees defining the degrees of freedom and a stabilization bilinear
form which has to satisfy two properties of simple verification: stability and
polynomial consistency. Several examples of methods available in the recent
literature are shown to belong to either one of those families. We then prove
new equivalence results that build a bridge between the two families of
methods. Precisely, we show that for any mixed method there exists a
corresponding equivalent primal method, and the converse is true provided that
the gradients are approximated in suitable spaces. A unified convergence
analysis is also carried out delivering optimal error estimates in both energy-
and $L^2$-norms.


title: New MDS or near MDS self-dual codes over finite fields

abstract:
  The study of MDS self-dual codes has attracted lots of attention in recent
years.
  There are many papers on determining existence of $q-$ary MDS self-dual codes
for various lengths.
  There are not existence of $q-$ary MDS self-dual codes of some lengths, even
these lengths $< q$.
  We generalize MDS Euclidean self-dual codes to near MDS Euclidean self-dual
codes and near MDS isodual codes.
  And we obtain many new near MDS isodual codes from extended negacyclic duadic
codes and we obtain many new MDS Euclidean self-dual codes from MDS Euclidean
self-dual codes.
  We generalize MDS Hermitian self-dual codes to near MDS Hermitian self-dual
codes.
  We obtain near MDS Hermitian self-dual codes from extended negacyclic duadic
codes and from MDS Hermitian self-dual codes.


title:
Automating Large-Scale Simulation and Data Analysis with OMNeT++:
  Lession Learned and Future Perspectives

abstract:
  Simulation is widely adopted in the study of modern computer networks. In
this context, OMNeT++ provides a set of very effective tools that span from the
definition of the network, to the automation of simulation execution and quick
result representation. However, as network models become more and more complex
to cope with the evolution of network systems, the amount of simulation
factors, the number of simulated nodes and the size of results grow
consequently, leading to simulations with larger scale. In this work, we
perform a critical analysis of the tools provided by OMNeT++ in case of such
large-scale simulations. We then propose a unified and flexible software
architecture to support simulation automation.


title: WiFi-Direct Simulation for INET in OMNeT++

abstract:
  Wi-Fi Direct is a popular wireless technology which is integrated in most of
today's smartphones and tablets. This technology allows a set of devices to
dynamically negotiate and select a group owner which plays the role access
point. This important feature is the strength of Wi-Fi Direct and makes it more
and more widely used in telecommunications networks. In this paper, we present
the implementation of Wi-Fi Direct in the INET framework of OMNeT++. We have
implemented the main procedures of Wi-Fi Direct such as discovery, negotiation
and group formation. The implementation has been validated by two test
scenarios which show the conformity of the implementation to the protocol
specification.


title: Chiral spiral induced by a strong magnetic field

abstract:
  We study the modification of the chiral phase structure of QCD due to an
external magnetic field. We first demonstrate how the effect of magnetic field
can systematically be incorporated into a generalized Ginzburg-Landau
framework. We then analyze the phase structure in the vicinity of the chiral
critical point. In the chiral limit, the effect is found to be so drastic that
it totally washes the tricritical point out of the phase diagram, bringing the
continent for the chiral spiral. This is the case no matter how small is the
intensity of the magnetic field. On the other hand, the current quark mass
protects the chiral critical point from a weak magnetic field. However the
critical point will eventually be covered by the chiral spiral phase as the
magnetic field grows.


title:
C-Planarity of Overlapping Clusterings Including Unions of Two
  Partitions

abstract:
  We show that clustered planarity with overlapping clusters as introduced by
Didimo et al. can be solved in polynomial time if each cluster induces a
connected subgraph. It can be solved in linear time if the set of clusters is
the union of two partitions of the vertex set such that, for each cluster, both
the cluster and its complement, induce connected subgraphs. Clustered planarity
with overlapping clusters is NP-complete, even if restricted to instances where
the underlying graph is 2-connected, the set of clusters is the union of two
partitions and each cluster contains at most two connected components while
their complements contain at most three connected components.


title: Explicit height bounds and the explicit Mordell-Lang Conjecture

abstract:
  We give an overview of some landmark theorems and recent conjectures in
Diophantine Geometry. In the elliptic case, we prove some new bounds for
torsion anomalous points and we clarify the implications of several height
bounds on the effective Mordell-Lang Conjecture. We also explicitly bound the
Neron-Tate height of the rational points of a family of curves of increasing
genus.


title:
Recursive nearest agglomeration (ReNA): fast clustering for
  approximation of structured signals

abstract:
  In this work, we revisit fast dimension reduction approaches, as with random
projections and random sampling. Our goal is to summarize the data to decrease
computational costs and memory footprint of subsequent analysis. Such dimension
reduction can be very efficient when the signals of interest have a strong
structure, such as with images. We focus on this setting and investigate
feature clustering schemes for data reductions that capture this structure. An
impediment to fast dimension reduction is that good clustering comes with large
algorithmic costs. We address it by contributing a linear-time agglomerative
clustering scheme, Recursive Nearest Agglomeration (ReNA). Unlike existing fast
agglomerative schemes, it avoids the creation of giant clusters. We empirically
validate that it approximates the data as well as traditional
variance-minimizing clustering schemes that have a quadratic complexity. In
addition, we analyze signal approximation with feature clustering and show that
it can remove noise, improving subsequent analysis steps. As a consequence,
data reduction by clustering features with ReNA yields very fast and accurate
models, enabling to process large datasets on budget. Our theoretical analysis
is backed by extensive experiments on publicly-available data that illustrate
the computation efficiency and the denoising properties of the resulting
dimension reduction scheme.


title: Maximal zero product subrings and inner ideals of simple rings

abstract:
  Let Q be a (non-unital) simple ring. A nonempty subset S of Q is said to have
zero product if S^2=0. We classify all maximal zero product subsets of Q. We
also describe the relationship between the maximal zero product subsets of Q
and the maximal inner ideals of its associated Lie algebra.


title: A note on approximation of plurisubharmonic functions

abstract:
  We extend a recent result of Avelin, Hed, and Persson about approximation of
functions $u$ that are plurisubharmonic on a domain $\Omega$ and continuous on
$\bar\Omega$, with functions that are plurisubharmonic on (shrinking)
neighborhoods of $\bar\Omega$. We show that such approximation is possible if
the boundary of $\Omega$ is $C^0$ outside a countable exceptional set
$E\subset\partial \Omega$. In particular, approximation is possible on the
Hartogs triangle. For H\"older continuous $u$, approximation is possible under
less restrictive conditions on $E$. We next give examples of domains where this
kind of approximation is not possible, even when approximation in the H\"older
continuous case is possible.


title:
Generalized Nehari manifold and semilinear Schr\"odinger equation with
  weak monotonicity condition on the nonlinear term

abstract:
  We study the Schr\"odinger equations $-\Delta u + V(x)u = f(x,u)$ in
$\mathbb{R}^N$ and $-\Delta u - \lambda u = f(x,u)$ in a bounded domain
$\Omega\subset\mathbb{R}^N$. We assume that $f$ is superlinear but of
subcritical growth and $u\mapsto f(x,u)/|u|$ is nondecreasing. In
$\mathbb{R}^N$ we also assume that $V$ and $f$ are periodic in
$x_1,\ldots,x_N$. We show that these equations have a ground state and that
there exist infinitely many solutions if $f$ is odd in $u$. Our results
generalize those in \cite{sw1} where $u\mapsto f(x,u)/|u|$ was assumed to be
strictly increasing. This seemingly small change forces us to go beyond methods
of smooth analysis.


title:
An analytical solution in the complex plane for the luminosity distance
  in flat cosmology

abstract:
  We present an analytical solution for the luminosity distance in spatially
flat cosmology with pressureless matter and the cosmological constant. The
complex analytical solution is made of a real part and a negligible imaginary
part. The real part of the luminosity distance allows finding the two
parameters $H_0$ and $\om$. A simple expression for the distance modulus for
SNs of type Ia is reported in the framework of the minimax approximation.


title:
Fluidic vortices generated from optical vortices in a microdroplet
  cavity

abstract:
  We harness the momentum of light resonating inside a micro-droplet cavity, to
experimentally generate micro-flows within the envelope of the drop. We 3D map
these optically induced flows by using fluorescent nanoparticles; which reveals
circular micro-streams. The flows are parametrically studied and, as expected,
exhibit an increase of rotation speed with optical power. The flow is
non-circular only when we intentionally break the axial symmetry of the
droplet. Besides the fundamental interest in light-flow interactions including
in opto-fluidic cavities, the optically controlled flows can serve in bringing
analytes into the maximum-power region of the microcavity.


title:
Quasi-two-body decays $B\to K\rho\to K\pi\pi$ in perturbative QCD
  approach

abstract:
  We analyze the quasi-two-body decays $B\to K\rho\to K\pi\pi$ in the
perturbative QCD (PQCD) approach, in which final-state interactions between the
pions in the resonant regions associated with the $P$-wave states $\rho(770)$
and $\rho^\prime(1450)$ are factorized into two-pion distribution amplitudes.
Adopting experimental inputs for the time-like pion form factors involved in
two-pion distribution amplitudes, we calculate branching ratios and direct $CP$
asymmetries of the $B\to K\rho(770),K\rho^\prime(1450)\to K\pi\pi$ modes. It is
shown that agreement of theoretical results with data can be achieved, through
which Gegenbauer moments of the $P$-wave two-pion distribution amplitudes are
determined. The consistency between the three-body and two-body analyses of the
$B\to K\rho(770)\to K\pi\pi$ decays supports the PQCD factorization framework
for exclusive hadronic $B$ meson decays.


title: An Explicit Manin-Dem'janenko theorem in elliptic curves

abstract:
  Let C be a curve of genus at least 2 imbedded in a product of elliptic
curves. We give an explicit upper bound for the points in the intersection of C
with the union of all algebraic subgroups of a certain codimension. As a
corollary we obtain an explicit upper bound for the height of the rational
points for some families of curves and an explicit version of the
Manin-Dem'janenko method in products of elliptic curves


title:
On resolvent matrix, Dyukarev-Stieltjes parameters and orthogonal matrix
  polynomials via $[0,\infty)$-Stieltjes transformed sequences

abstract:
  By using Schur transformed sequences and Dyukarev-Stieltjes parameters we
obtain a new representation of the resolvent matrix corresponding to the
truncated matricial Stieltjes moment problem. Explicit relations between
orthogonal matrix polynomials and matrix polynomials of the second kind
constructed from consecutive Schur transformed sequences are obtained.
Additionally, a non-negative Hermitian measure for which the matrix polynomials
of the second kind are the orthogonal matrix polynomials is found.


title:
TAUOLA of tau lepton decays-- framework for hadronic currens, matrix
  elements and anomalous decays

abstract:
  We present an update of the Monte Carlo event generator TAUOLA for tau lepton
decays, with substantially increased list of decay channels and new
initialization options. The core of the program remains written in FORTRAN but
necessary arrangements have been made to allow handling of the user-provided
hadronic currents and matrix elements at the execution time. Such solution may
simplify preparation of new hadronic currents and may be useful for fitting to
the experimental data as well.
  We have implemented as default for TAUOLA a set of hadronic currents, which
is compatible with the default initialization used by BaBar collaboration.
Options for currents available in previous releases are still stored in the
code, sometimes left defunct or activated by internal flags only. The new
version of the program, includes also implementation of Lepton Flavour
Violating tau decays.
  Finally, we present, as an example, a set of C++ methods for handling
user-provided currents, matrix elements or complete new decay channels
initialization which can be performed at the program execution time.


title: From H&M to Gap for Lightweight BWT Merging

abstract:
  Recently, Holt and McMillan [Bionformatics 2014, ACM-BCB 2014] have proposed
a simple and elegant algorithm to merge the Burrows-Wheeler transforms of a
family of strings. In this paper we show that the H&M algorithm can be improved
so that, in addition to merging the BWTs, it can also merge the Longest Common
Prefix (LCP) arrays. The new algorithm, called Gap because of how it operates,
has the same asymptotic cost as the H&M algorithm and requires additional space
only for storing the LCP values.


title: Spin pumping and torque statistics in the quantum noise limit

abstract:
  We analyze the statistics of charge and energy currents and spin torque in a
metallic nanomagnet coupled to a large magnetic metal via a tunnel contact. We
derive a Keldysh action for the tunnel barrier, describing the stochastic
currents in the presence of a magnetization precessing with the rate $\Omega$.
In contrast to some earlier approaches, we include the geometric phases that
affect the counting statistics. We illustrate the use of the action by deriving
spintronic fluctuation relations, the quantum limit of pumped current noise,
and consider the fluctuations in two specific cases: the situation with a
stable precession of magnetization driven by spin transfer torque, and the
torque-induced switching between the minima of a magnetic anisotropy. The
quantum corrections are relevant when the precession rate exceeds the
temperature $T$, i.e., for $\hbar \Omega \gtrsim k_B T$.


title: Price impact without order book: A study of the OTC credit index market

abstract:
  We present a study of price impact in the over-the-counter credit index
market, where no limit order book is used. Contracts are traded via dealers,
that compete for the orders of clients. Despite this distinct microstructure,
we successfully apply the propagator technique to estimate the price impact of
individual transactions. Because orders are typically split less than in
multilateral markets, impact is observed to be mainly permanent, in line with
theoretical expectations. A simple method is presented to correct for errors in
our classification of trades between buying and selling. We find a very
significant, temporary increase in order flow correlations during late 2015 and
early 2016, which we attribute to increased order splitting or herding among
investors. We also find indications that orders advertised to less dealers may
have lower price impact. Quantitative results are compatible with earlier
findings in other more classical markets, further supporting the argument that
price impact is a universal phenomenon, to a large degree independent of market
microstructure.


title: Factored Neural Machine Translation

abstract:
  We present a new approach for neural machine translation (NMT) using the
morphological and grammatical decomposition of the words (factors) in the
output side of the neural network. This architecture addresses two main
problems occurring in MT, namely dealing with a large target language
vocabulary and the out of vocabulary (OOV) words. By the means of factors, we
are able to handle larger vocabulary and reduce the training time (for systems
with equivalent target language vocabulary size). In addition, we can produce
new words that are not in the vocabulary. We use a morphological analyser to
get a factored representation of each word (lemmas, Part of Speech tag, tense,
person, gender and number). We have extended the NMT approach with attention
mechanism in order to have two different outputs, one for the lemmas and the
other for the rest of the factors. The final translation is built using some
\textit{a priori} linguistic information. We compare our extension with a
word-based NMT system. The experiments, performed on the IWSLT'15 dataset
translating from English to French, show that while the performance do not
always increase, the system can manage a much larger vocabulary and
consistently reduce the OOV rate. We observe up to 2% BLEU point improvement in
a simulated out of domain translation setup.


title: Algebraic models of homotopy types and the homotopy hypothesis

abstract:
  We introduce and study a notion of cylinder coherator similar to the notion
of Grothendieck coherator which define more flexible notion of weak infinity
groupoids. We show that each such cylinder coherator produces a combinatorial
semi-model category of weak infinity groupoids, whose objects are all fibrant
and which is in a precise sense "freely generated by an object". We show that
all those semi model categories are Quillen equivalent together and Quillen to
the model category of spaces. A general procedure is given to produce such
coherator, and several explicit examples are presented: one which is simplicial
in nature and allows the comparison to the model category for spaces. A second
example can be describe as the category of globular sets endowed with "all the
operations that can be defined within a weak type theory". This second notion
seem to provide a definition of weak infinity groupoids which can be defined
internally within type theory and which is classically equivalent to homotopy
types. Finally, the category of Grothendieck infinity groupoids for a fixed
Grothendieck coherator would be an example of this formalism under a seemingly
simple conjecture whose validity is shown to imply Grothendieck homotopy
hypothesis. This conjecture seem to sum up what needs to be proved at a
technical level to ensure that the theory of Grothendieck weak infinity
groupoid is well behaved.


title:
Distributed Estimation of the Operating State of a Single-Bus DC
  MicroGrid without an External Communication Interface

abstract:
  We propose a decentralized Maximum Likelihood solution for estimating the
stochastic renewable power generation and demand in single bus Direct Current
(DC) MicroGrids (MGs), with high penetration of droop controlled power
electronic converters. The solution relies on the fact that the primary control
parameters are set in accordance with the local power generation status of the
generators. Therefore, the steady state voltage is inherently dependent on the
generation capacities and the load, through a non-linear parametric model,
which can be estimated. To have a well conditioned estimation problem, our
solution avoids the use of an external communication interface and utilizes
controlled voltage disturbances to perform distributed training. Using this
tool, we develop an efficient, decentralized Maximum Likelihood Estimator (MLE)
and formulate the sufficient condition for the existence of the globally
optimal solution. The numerical results illustrate the promising performance of
our MLE algorithm.


title:
Self-consistent mapping: Effect of local environment on formation of
  magnetic moment in alpha-FeSi2

abstract:
  We suggest here the method of the mapping of DFT calculations on the
multiorbital model in a following way: the parameters of the formulated
multiorbital model should be determined from the requirement that the
self-consistent charge and spin densities found from the ab initio and model
calculations have to be as close to each other as possible. The analysis of the
model allows for detailed understanding of the role played by different
parameters of the model in the physics of interest. As an example of the
approach we present the study of the effect of silicon atoms substitution by
the iron atoms and vice versa on the magnetic properties in the iron silicide
alpha-FeSi2. The DFT+GGA calculations are mapped to the model with intraatomic
Coulomb and exchange interactions, hoppings to nearest and next nearest atoms
and exchange of the delocalized electrons between iron atoms; the magnetic
moments on atoms and charge densities of the material are found
self-consistently within the Hartree-Fock approximation. We find that while the
stoichiometric alpha-FeSi2 is nonmagnetic, the substitutions generate different
magnetic structures. For example, the substitution of three Si atoms by the Fe
atoms results in the ferrimagnetic structure whereas the substitution of four
Si atoms by Fe atoms gives rise to either the nonmagnetic or the ferromagnetic
state depending on the type of local enviroment of the substitutional Fe atoms.
Besides, contrary to the commonly accepted statement that the destruction of
the magnetic moment is controlled only by the number of Fe-Si nearest
neighbors, we find that actually it is controlled by the Fe-Fe
next-nearest-neighbors. This finding led us to the counterintuitive conclusion:
an increase of Si concentration in Fe1-xSi2+x ordered alloys may lead to a
ferromagnetism. This conclusion is confirmed by the calculation within
GGA-to-DFT.


title: Quantum synchronization in disordered superconducting metamaterials

abstract:
  I report a theoretical study of collective coherent quantum-mechanical
oscillations in disordered superconducting quantum metamaterials (SQMs), i.e
artificially fabricated arrays of interacting qubits (two-levels system). An
unavoidable disorder in qubits parameters results in a substantial spread of
qubits frequencies, and in the absence of electromagnetic interaction between
qubits these individual quantum-mechanical oscillations of single qubits
manifest themselves by a large number of small resonant drops in the frequency
dependent transmission of electromagnetic waves propagating through disordered
SQM, $D(\omega)$. We show that even a weak electromagnetic interaction between
adjacent qubits can overcome the disorder and establish completely or partially
\emph{synchronized} quantum-mechanical dynamic state in the disordered SQM. In
such a state a large amount of qubits displays the collective quantum
mechanical oscillations, and this collective behavior manifests itself by a few
giant resonant drops in the $D(\omega)$ dependence. The size of a system $r_0$
showing the collective (synchronized) quantum-mechanical behavior is determined
in the one-dimensional SQMs as $r_0 \simeq a [K/\delta \Delta]^2$, where $K$,
$\delta \Delta$, $a$ are the energy of nearest-neighbor interaction, the spread
of qubits energy splitting, and the distance between qubits, accordingly. We
show that this phenomenon has an origin in the Anderson localization of
spinon-type excitations arising in the SQM. Our analysis is also in a good
accord with recent experiments on the electrodynamics of the disordered 1D
SQMs.


title:
The 26 Wilf-equivalence classes of length five quasi-consecutive
  patterns

abstract:
  We present two families of Wilf-equivalences for consecutive and
quasi-consecutive vincular patterns. These give new proofs of the
classification of consecutive patterns of length $4$ and $5$. We then prove
additional equivalences to explicitly classify all quasi-consecutive patterns
of length $5$ into 26 Wilf-equivalence classes.


title:
Non-Abelian fermion parity interferometry of Majorana bound states in a
  Fermi sea

abstract:
  We study the quantum dynamics of Majorana and regular fermion bound states
coupled to a quasi-one-dimensional metallic lead. The dynamics following the
quench in the coupling to the lead exhibits a series of dynamical revivals as
the bound state propagates in the lead and reflects from the boundaries. We
show that the nature of revivals for a single Majorana bound state depends
uniquely on the presence of a resonant level in the lead. When two spatially
separated Majorana modes are coupled to the lead, the revivals depend only on
the phase difference between their host superconductors. Remarkably, the quench
in this case effectively performs a fermion-parity interferometry between
Majorana bound states, revealing their unique non-Abelian braiding. Using both
analytical and numerical techniques, we find the pattern of fermion parity
transfers following the quench, study its evolution in the presence of disorder
and interactions, and thus, ascertain the fate of Majorana bound states in a
Fermi sea.


title: Context Aware Nonnegative Matrix Factorization Clustering

abstract:
  In this article we propose a method to refine the clustering results obtained
with the nonnegative matrix factorization (NMF) technique, imposing consistency
constraints on the final labeling of the data. The research community focused
its effort on the initialization and on the optimization part of this method,
without paying attention to the final cluster assignments. We propose a game
theoretic framework in which each object to be clustered is represented as a
player, which has to choose its cluster membership. The information obtained
with NMF is used to initialize the strategy space of the players and a weighted
graph is used to model the interactions among the players. These interactions
allow the players to choose a cluster which is coherent with the clusters
chosen by similar players, a property which is not guaranteed by NMF, since it
produces a soft clustering of the data. The results on common benchmarks show
that our model is able to improve the performances of many NMF formulations.


title: Institutionalization in Efficient Markets: The Case of Price Bubbles

abstract:
  We seek to deepen understanding of the micro-foundations of
institutionalization while contributing to a sociological theory of markets by
investigating the puzzle of price bubbles in financial markets. We find that
such markets, despite textbook conditions of high efficiency -- perfect
information, atomistic agents, no uncertainty -- quickly develop patterns
consistent with institutionalization processes.


title: Chaos driven by interfering memory

abstract:
  The transmission of information can couple two entities of very different
nature, one of them serving as a memory for the other. Here we study the
situation in which information is stored in a wave field and serves as a memory
that pilots the dynamics of a particle. Such a system can be implemented by a
bouncing drop generating surface waves sustained by a parametric forcing. The
motion of the resulting "walker" when confined in a harmonic potential well is
generally disordered. Here we show that these trajectories correspond to
chaotic regimes characterized by intermittent transitions between a discrete
set of states. At any given time, the system is in one of these states
characterized by a double quantization of size and angular momentum. A low
dimensional intermittency determines their respective probabilities. They thus
form an eigenstate basis of decomposition for what would be observed as a
superposition of states if all measurements were intrusive.


title:
Homogenization of weakly coercive integral functionals in
  three-dimensional elasticity

abstract:
  This paper deals with the homogenization through $\Gamma$-convergence of
weakly coercive integral energies with the oscillating density
$\mathbb{L}(x/\epsilon)\nabla v : \nabla v$ in three-dimensional elasticity.
The energies are weakly coercive in the sense where the classical functional
coercivity satisfied by the periodic tensor L (using smooth test functions v
with compact support in $\mathbb{R}^3$) which reads as $\Lambda(\mathbb{L})
>0$, is replaced by the relaxed condition $\Lambda(\mathbb{L}) \ge 0$.
Surprisingly, we prove that contrary to the two-dimensional case of [2] which
seems a priori more constrained, the homogenized tensor $\mathbb{L}^0$ remains
strongly elliptic, or equivalently $\Lambda(\mathbb{L}^0) >0$, for any tensor
$\mathbb{L} = \mathbb{L}(y_1)$ satisfying $\mathbb{L}(y)M : M + D : {\rm
Cof}(M) \ge 0$, a.e. $y \in \mathbb{R}^3$, $\forall M \in \mathbb{R}^{3\times
3}$, for some matrix $D \in \mathbb{R}^{3\times3}$ (which implies
$\Lambda(\mathbb{L}) \ge 0$), and the periodic functional coercivity (using
smooth test functions $v$ with periodic gradients) which reads as $\Lambda_{\rm
per}(\mathbb{L})>0$. Moreover, we derive the loss of strong ellipticity for the
homogenized tensor using a rank-two lamination, which justifies by
$\Gamma$-convergence the formal procedure of [8].


title:
Modeling the deep drawing of a 3D woven fabric with a second gradient
  model

abstract:
  Experimental testing on dry woven fabrics exhibits a complex set of evidences
that are difficult to be completely described using classical continuum models.
The aim of this paper is to show how the introduction of energy terms related
to the micro-deformation mechanisms of the fabric, in particular to the bending
stiffness of the yarns, helps in the modeling of the mechanical behavior of
this kind of materials. To this aim, a second gradient, hyperelastic, initially
orthotropic continuum theory is proposed to model fibrous composite interlocks
at finite strains. In particular, the present work explores the relationship
between the onset of wrinkling appearing during the simulation of the deep
drawing of a woven fabric and the use of a second gradient model. It is shown
that the introduction of second gradient terms accounting for the description
of in-plane and out-of-plane bending rigidities, decreases the onset of
wrinkles during the simulation of deep-drawing.
  In this work, a quadratic energy, roughly proportional to the square of the
curvature of the fibers, is presented and implemented in the simulations. This
simple constitutive assumption allows to clearly show the effects of the second
gradient energy on both the wrinkling description and the numerical stability
of the model. The results obtained in second gradient simulations are
descriptive of the experimental evidence of deep drawing whose description is
targeted in this work. The present paper provides additional evidence of the
fact that first gradient continuum theories alone cannot be considered fully
descriptive of the behavior of dry woven composite reinforcements. On the other
hand, the proposed second gradient model for fibrous composite reinforcements
opens the way both to the more accurate simulation of complex forming processes
and to the possibility of controlling the onset of wrinkles.


title: The Seebeck coefficient in correlated low dimensional organic metals

abstract:
  We study the influence of inelastic electron-electron scattering on the
temperature variation of the Seebeck coefficient in the normal phase of
quasi-one-dimensional organic superconductors. The theory is based on the
numerical solution of the semi-classical Boltzmann equation for which the
collision integral equation is solved with the aid of the electronic umklapp
scattering vertex calculated by the renormalization group method. We show that
the one-loop renormalization group flow of momentum and temperature dependent
umklapp scattering, in the presence of nesting alterations of the Fermi
surface, introduce electron-hole asymmetry in the energy dependence of the
anisotropic scattering time. This is responsible for the enhancement of the
Seebeck coefficient with respect to the band $T$-linear prediction and even its
sign reversal around the quantum critical point of the phase diagram, namely
where the interplay between antiferromagnetism and superconductivity along with
the strength of spin fluctuations are the strongest. Comparison of the results
with available data on low dimensional organic superconductors is presented and
critically discussed.


title:
Bright hot impacts by erupted fragments falling back on the Sun:
  magnetic channelling

abstract:
  Dense plasma fragments were observed to fall back on the solar surface by the
Solar Dynamics Observatory after an eruption on 7 June 2011, producing strong
EUV brightenings. Previous studies investigated impacts in regions of weak
magnetic field. Here we model the $\sim~300$ km/s impact of fragments
channelled by the magnetic field close to active regions. In the observations,
the magnetic channel brightens before the fragment impact. We use a 3D-MHD
model of spherical blobs downfalling in a magnetized atmosphere. The blob
parameters are constrained from the observation. We run numerical simulations
with different ambient density and magnetic field intensity. We compare the
model emission in the 171\AA~ channel of the Atmospheric Imaging Assembly with
the observed one. We find that a model of downfall channelled in a $\sim~1$MK
coronal loop confined by a magnetic field of $\sim~10-20$G, best explains
qualitatively and quantitatively the observed evolution. The blobs are highly
deformed, further fragmented, when the ram pressure becomes comparable to the
local magnetic pressure and they are deviated to be channelled by the field,
because of the differential stress applied by the perturbed magnetic field.
Ahead of them, in the relatively dense coronal medium, shock fronts propagate,
heat and brighten the channel between the cold falling plasma and the solar
surface. This study shows a new mechanism which brightens downflows channelled
by the magnetic field, such as in accreting young stars, and also works as a
probe of the ambient atmosphere, providing information about the local plasma
density and magnetic field.


title: ET Probes: Looking Here as Well as There

abstract:
  Almost all SETI searches to date have explicitly targeted stars in the hope
of detecting artificial radio or optical transmissions. It is argued that
extra-terrestrials (ET) might regard sending physical probes to our own Solar
System as a more efficient means for sending large amounts of information to
Earth. Probes are more efficient in terms of energy and time expenditures; may
solve for the vexing problem of Drake's L factor term, namely, that the
civilization wishing to send information may not coexist temporally with the
intended recipient; and they alleviate ET's reasonable fear that the intended
recipient might prove hostile. It is argued that probes may be numerous and
easier to find than interstellar beacons.


title:
Human brain parcellation using time courses of instantaneous
  connectivity

abstract:
  Functional neuroimaging studies have lead to understanding the brain as a
collection of spatially segregated functional networks. It is thought that each
of these networks is in turn composed of a set of distinct sub-regions that
together support each network's function. Considering the sub-regions to be an
essential part of the brain's functional architecture, several strategies have
been put forward that aim at identifying the functional sub-units of the brain
by means of functional parcellations. Current parcellation strategies typically
employ a bottom-up strategy, creating a parcellation by clustering smaller
units. We propose a novel top-down parcellation strategy, using time courses of
instantaneous connectivity to subdivide an initial region of interest into
sub-regions. We use split-half reproducibility to choose the optimal number of
sub-regions. We apply our Instantaneous Connectivity Parcellation (ICP)
strategy on high-quality resting-state FMRI data, and demonstrate the ability
to generate parcellations for thalamus, entorhinal cortex, motor cortex, and
subcortex including brainstem and striatum. We evaluate the subdivisions
against available cytoarchitecture maps to show that the our parcellation
strategy recovers biologically valid subdivisions that adhere to known
cytoarchitectural features.


title: Quantitative assessment of increasing complexity

abstract:
  We study the build up of complexity on the example of 1 kg matter in
different forms. We start on the simplest example of ideal gases, and then
continue with more complex chemical, biological, life and social and technical
structures. We assess the complexity of these systems quantitatively, based on
their entropy. We present a method to attribute the same entropy to known
physical systems and to complex organic molecules up to a DNA. The important
steps in this program and the basic obstacles are discussed.


title: Light Will be Thrown: The Emerging Science of Cultural Evolution

abstract:
  Culture evolves, not just in the trivial sense that cultures change over
time, but also in the strong sense that such change is governed by Darwinian
principles. Both biological and cultural evolution are essentially cumulative
selection processes in which information (whether genetic or cultural) is
sieved, retained and then transmitted to the next generation. In both domains
such a process will result in recognizable lineages and tree-like phylogenies
so characteristic of Darwinian evolution. Because a principle of inheritance
(i.e., faithful replication of information) holds in both domains, we may trace
back particular transmission histories and identify the forces that influenced
them. The idea that culture evolves is quite old, but only in recent years
there has been a serious effort to turn this idea into science. This article
offers a concise analysis of how a rudimentary idea gradually evolved into a
thriving research program.


title:
Influence of humidity on the tribo-electric charging and segregation in
  shaken granular media

abstract:
  We study the effect of humidity on the charge accumulation of polymer
granulates shaken vertically in a stainless steel container. The setup allows
to control the humidity level from 5 % to 100 %RH while performing automated
charge measurements in a Faraday cup directly connected to the shaking
container. We find that samples of approximately 2000 polymer spheres become
highly charged at low humidity levels (<30 %RH), but acquire almost no charge
for humidity levels above 80 %RH. The transition between these two regimes does
depend on the material, as does the sign of the charge. For the latter we find
a correlation with the contact angle of the polymer with only very hydrophilic
particles attaining positive charges. We show that this humidity dependence of
tribo-charging can be used to control segregation in shaken binary mixtures.


title:
Statistically validated lead-lag networks and inventory prediction in
  the foreign exchange market

abstract:
  We introduce a method to infer lead-lag networks of agents' actions in
complex systems. These networks open the way to both microscopic and
macroscopic states prediction in such systems. We apply this method to
trader-resolved data in the foreign exchange market. We show that these
networks are remarkably persistent, which explains why and how order flow
prediction is possible from trader-resolved data. In addition, if traders'
actions depend on past prices, the evolution of the average price paid by
traders may also be predictable. Using random forests, we verify that the
predictability of both the sign of order flow and the direction of average
transaction price is strong for retail investors at an hourly time scale, which
is of great relevance to brokers and order matching engines. Finally, we argue
that the existence of trader lead-lag networks explains in a self-referential
way why a given trader becomes active, which is in line with the fact that most
trading activity has an endogenous origin.


title: Spinodal instabilities in polydisperse lyotropic nematics

abstract:
  Many lyotropic liquid crystals are composed of mesogens that display a
considerable spread in size or shape affecting their material properties and
thermodynamics via various demixing and multi-phase coexistence scenarios.
Starting from a generalized Onsager theory we formulate a generic framework
that enables locating spinodal polydispersities as well as identifying the
nature of incipient size fractionation for arbitrary model potentials and size
distributions. We apply our theory to nematic phases of both hard rods and
disks whose main particle dimension is described by a unimodal log-normal
distribution. We find that both rod-based and discotic nematics become unstable
at a critical polydispersity of about 20 %. We also investigate the effect of
doping nematic assemblies with a small fraction of large species and highlight
their effect on the stability of the uniform nematic fluid. We find that while
rod-based are only weakly affected by the presence of large species, doping
discotic nematics with very large platelets leads to a remarkable suppression
of the spinodal instabilities. This could open up routes towards controlling
the mechanical properties of nematic materials by manipulating the local
stability of nematic fluid and its tendency to undergo fractionation-driven
microphase separation.


title: Effective resistances and Kirchhoff Index in subdivision networks

abstract:
  We define a subdivision network $\Gamma^S$ of a given network $\Gamma,$ by
inserting a new vertex in every edge, so that each edge is replaced by two new
edges with conductances that fulfill electrical conditions on the new network.
In this work, we firstly obtain an expression for the Green kernel of the
subdivision network in terms of the Green kernel of the base network. Moreover,
we also obtain the effective resistance and the Kirchhoff index of the
subdivision network in terms of the corresponding parameters on the base
network. Finally, as an example, we carry out the computations in the case of a
wheel.


title:
Terahertz-driven Luminescence and Colossal Stark Effect in CdSe:CdS
  Colloidal Quantum Dots

abstract:
  Unique optical properties of colloidal semiconductor quantum dots (QDs),
arising from quantum mechanical confinement of charge within these structures,
present a versatile testbed for the study of how high electric fields affect
the electronic structure of nanostructured solids. Earlier studies of quasi-DC
electric field modulation of QD properties have been limited by the
electrostatic breakdown processes under the high externally applied electric
fields, which have restricted the range of modulation of QD properties. In
contrast, in the present work we drive CdSe:CdS core:shell QD films with
high-field THz-frequency electromagnetic pulses whose duration is only a few
picoseconds. Surprisingly, in response to the THz excitation we observe QD
luminescence even in the absence of an external charge source. Our experiments
show that QD luminescence is associated with a remarkably high and rapid
modulation of the QD band-gap, which is changing by more than 0.5 eV
(corresponding to 25% of the unperturbed bandgap energy) within the picosecond
timeframe of THz field profile. We show that these colossal energy shifts can
be consistently explained by the quantum confined Stark effect. Our work
demonstrates a route to extreme modulation of material properties without
configurational changes in material sets or geometries. Additionally, we expect
that this platform can be adapted to a novel compact THz detection scheme where
conversion of THz fields (with meV-scale photon energies) to the
visible/near-IR band (with eV-scale photon energies) can be achieved at room
temperature with high bandwidth and sensitivity.


title: A study of the interrelation between fuzzy topological systems and logic

abstract:
  The major part of this thesis deals with fuzzy geometric logic and fuzzy
geometric logic with graded consequence. The first chapter mainly contains the
concept of topological system introduced by S. Vickers in 1989. In Chapter 2
the notion of fuzzy topological system is introduced and categorical
relationship with fuzzy topology and frame is discussed in detail. Also this
chapter contains some methodology to make new fuzzy topological systems from
the old one.Chapter 3 provides a generalization of fuzzy topological system
which shall be called L topological system and categorical relationships with
appropriate topological space and frame. Furthermore, two ways of constructing
subspaces and subsystems of an L topological space and an L topological system
are respectively provided.Chapter 4 deals with the concept of variable basis
fuzzy topological space on fuzzy sets and contains a new notion of variable
basis fuzzy topological systems whose underlying sets are fuzzy sets. In this
chapter categorical relationship between space and system is established.
Chapter 5 contains a different proof of one kind of generalized stone duality,
which was done directly by Maruyama, introducing a notion of n fuzzy Boolean
system. The last two chapters, Chapter 6 and Chapter 7 deal the ultimate
objective. Chapter 6 deals with the question- From which logic fuzzy topology
can be studied?. To answer this, the notion of fuzzy geometric logic is
invented.


title: From Path Integrals to Tensor Networks for AdS/CFT

abstract:
  In this paper, we discuss tensor network descriptions of AdS/CFT from two
different viewpoints. First, we start with an Euclidean path-integral
computation of ground state wave functions with a UV cut off. We consider its
efficient optimization by making its UV cut off position dependent and define a
quantum state at each length scale. We conjecture that this path-integral
corresponds to a time slice of AdS. Next, we derive a flow of quantum states by
rewriting the action of Killing vectors of AdS3 in terms of the dual 2d CFT.
Both approaches support a correspondence between the hyperbolic time slice H2
in AdS3 and a version of continuous MERA (cMERA). We also give a heuristic
argument why we can expect a sub-AdS scale bulk locality for holographic CFTs.


title: Infinitely many twin primes

abstract:
  In the proposed matrix primes, through which one can readily generate a
sequence of primes. The paper also proposes a number of theorems proved by
which an infinite number of prime numbers twins


title:
Droplet growth during vapor-liquid transition in a 2D Lennard-Jones
  fluid

abstract:
  Results for the kinetics of vapor-liquid phase transition have been presented
from the molecular dynamics simulations of a single component two-dimensional
Lennard-Jones fluid. The phase diagram for the model, primary prerequisite for
this purpose, has been obtained via the Monte Carlo simulations. Our focus is
on the region very close to the vapor branch of the coexistence curve. Quenches
to such region provide morphology that consists of disconnected circular liquid
clusters in the vapor background. We identified that these clusters exhibit
diffusive motion and grow via sticky collisions among them. The growth follows
power-law behavior with time, exponent of which is found to be in nice
agreement with a theoretical prediction.


title: Sequencing Chess

abstract:
  We analyze the structure of the state space of chess by means of transition
path sampling Monte Carlo simulation. Based on the typical number of moves
required to transpose a given configuration of chess pieces into another, we
conclude that the state space consists of several pockets between which
transitions are rare. Skilled players explore an even smaller subset of
positions that populate some of these pockets only very sparsely. These results
suggest that the usual measures to estimate both, the size of the state space
and the size of the tree of legal moves, are not unique indicators of the
complexity of the game, but that topological considerations are equally
important.


title:
Mathematical Imaging Methods for Mitosis Analysis in Live-Cell Phase
  Contrast Microscopy

abstract:
  In this paper we propose a workflow to detect and track mitotic cells in
time-lapse microscopy image sequences. In order to avoid the requirement for
cell lines expressing fluorescent markers and the associated phototoxicity,
phase contrast microscopy is often preferred over fluorescence microscopy in
live-cell imaging. However, common specific image characteristics complicate
image processing and impede use of standard methods. Nevertheless, automated
analysis is desirable due to manual analysis being subjective, biased and
extremely time-consuming for large data sets. Here, we present the following
workflow based on mathematical imaging methods. In the first step, mitosis
detection is performed by means of the circular Hough transform. The obtained
circular contour subsequently serves as an initialisation for the tracking
algorithm based on variational methods. It is sub-divided into two parts: in
order to determine the beginning of the whole mitosis cycle, a backwards
tracking procedure is performed. After that, the cell is tracked forwards in
time until the end of mitosis. As a result, the average of mitosis duration and
ratios of different cell fates (cell death, no division, division into two or
more daughter cells) can be measured and statistics on cell morphologies can be
obtained. All of the tools are featured in the user-friendly
MATLAB$^{\circledR}$ Graphical User Interface MitosisAnalyser.


title: Green's theorem and Gorenstein sequences

abstract:
  We study consequences, for a standard graded algebra, of extremal behavior in
Green's Hyperplane Restriction Theorem. First, we extend his Theorem 4 from the
case of a plane curve to the case of a hypersurface in a linear space. Second,
assuming a certain Lefschetz condition, we give a connection to extremal
behavior in Macaulay's theorem. We apply these results to show that
$(1,19,17,19,1)$ is not a Gorenstein sequence, and as a result we classify the
sequences of the form $(1,a,a-2,a,1)$ that are Gorenstein sequences.


title: Strong Couplings of Three Mesons with Charm(ing) Involvement

abstract:
  We determine the strong couplings of three mesons that involve, at least, one
$\eta_c$ or $J/\psi$ meson, within the framework of a constituent-quark model
by means of relativistic dispersion formulations. For strong couplings of
$J/\psi$ mesons to two charmed mesons, our approach leads to predictions
roughly twice as large as those arising from QCD sum rules.


title:
Conformity in virtual environments: a hybrid neurophysiological and
  psychosocial approach

abstract:
  The main aim of our study was to analyse the effects of a virtual environment
on social conformity, with particular attention to the effects of different
types of task and psychological variables on social influence, on one side, and
to the neural correlates related to conformity, measured by means of an Emotiv
EPOC device on the other. For our purpose, we replicated the famous Asch's
visual task and created two new tasks of increasing ambiguity, assessed through
the calculation of the item's entropy. We also administered five scales in
order to assess different psychological traits. From the experiment, conducted
on 181 university students, emerged that conformity grows according to the
ambiguity of the task, but normative influence is significantly weaker in
virtual environments, if compared to face-to-face experiments. The analysed
psycho-logical traits, however, result not to be relatable to conformity, and
they only affect the subjects' response times. From the ERP (Event-related
potentials) analysis, we detected N200 and P300 components comparing the plots
of conformist and non-conformist subjects, alongside with the detection of
their Late Positive Potential, Readiness Potential, and Error-Related
Negativity, which appear consistently different for the two typologies.


title: Lost and Found: Detecting Small Road Hazards for Self-Driving Vehicles

abstract:
  Detecting small obstacles on the road ahead is a critical part of the driving
task which has to be mastered by fully autonomous cars. In this paper, we
present a method based on stereo vision to reliably detect such obstacles from
a moving vehicle. The proposed algorithm performs statistical hypothesis tests
in disparity space directly on stereo image data, assessing freespace and
obstacle hypotheses on independent local patches. This detection approach does
not depend on a global road model and handles both static and moving obstacles.
For evaluation, we employ a novel lost-cargo image sequence dataset comprising
more than two thousand frames with pixelwise annotations of obstacle and
free-space and provide a thorough comparison to several stereo-based baseline
methods. The dataset will be made available to the community to foster further
research on this important topic. The proposed approach outperforms all
considered baselines in our evaluations on both pixel and object level and runs
at frame rates of up to 20 Hz on 2 mega-pixel stereo imagery. Small obstacles
down to the height of 5 cm can successfully be detected at 20 m distance at low
false positive rates.


title: Fixed points of the equivariant algebraic $K$-theory of spaces

abstract:
  In a recent work Malkiewich and Merling proposed a definition of the
equivariant $K$-theory of spaces for spaces equipped with an action of a finite
group. We show that the fixed points of this spectrum admit a tom Dieck-type
splitting. We also show that this splitting is compatible with the splitting of
the equivariant suspension spectrum. The first of these results has been
obtained independently by John Rognes.


title: Light-Front Higher-Spin Theories in Flat Space

abstract:
  We revisit the problem of interactions of higher-spin fields in flat space.
We argue that all no-go theorems can be avoided by the light-cone approach,
which results in more interaction vertices as compared to the usual covariant
approaches. It is stressed that there exist two-derivative gravitational
couplings of higher-spin fields. We show that some reincarnation of the
equivalence principle still holds for higher-spin fields - the strength of
gravitational interaction does not depend on spin. Moreover, it follows from
the results by Metsaev that there exists a complete chiral higher-spin theory
in four dimensions. We give a simple derivation of this theory and show that
the four-point scattering amplitude vanishes. Also, we reconstruct the quartic
vertex of the scalar field in the unitary higher-spin theory, which turns out
to be perturbatively local.


title:
Collective Awareness Platforms and Digital Social Innovation Mediating
  Consensus Seeking in Problem Situations

abstract:
  In this paper we show the results of our studies carried out in the framework
of the European Project SciCafe2.0 in the area of Participatory Engagement
models. We present a methodological approach built on participative engagements
models and holistic framework for problem situation clarification and solution
impacts assessment. Several online platforms for social engagement have been
analysed to extract the main patterns of participative engagement. We present
our own experiments through the SciCafe2.0 Platform and our insights from
requirements elicitation.


title: Results of a Collective Awareness Platforms Investigation

abstract:
  In this paper we provide two introductory analyses of CAPs, based exclusively
on the analysis of documents found on the Internet. The first analysis allowed
us to investigate the world of CAPs, in particular for what concerned their
status (dead or alive), the scope of those platforms and the typology of users.
In order to develop a more accurate model of CAPs, and to understand more
deeply the motivation of the users and the type of expected payoff, we analysed
those CAPs from the above list that are still alive and we used two models
developed for what concerned the virtual community and the collective
intelligence.


title:
Analyzing Signal Attenuation in PFG Anomalous Diffusion via a Modified
  Gaussian Phase Distribution Approximation Based on Fractal Derivative Model

abstract:
  Pulsed field gradient (PFG) has been increasingly employed to study anomalous
diffusions in Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging
(MRI). However, the analysis of PFG anomalous diffusion is complicated. In this
paper, a fractal derivative model based modified Gaussian phase distribution
method is proposed to describe PFG anomalous diffusion. By using the phase
distribution obtained from the effective phase shift diffusion method based on
fractal derivatives, and employing some of the traditional Gaussian phase
distribution approximation techniques, a general signal attenuation expression
for free fractional diffusion is derived. This expression describes a stretched
exponential function based attenuation, which is distinct from both the
exponential attenuation for normal diffusion obtained from conventional
Gaussian phase distribution approximation, and the Mittag-Leffler function
based attenuation for anomalous diffusion obtained from fractional derivative.
The obtained signal attenuation expression can analyze the finite gradient
pulse width (FGPW) effect. Additionally, it can generally be applied to all
three types of PFG fractional diffusions classified based on time derivative
order alpha and space derivative order beta. These three types of fractional
diffusions include time-fractional diffusion, space-fractional diffusion, and
general fractional diffusion. The results in this paper are consistent with
reported results based on effective phase shift diffusion equation method and
instantaneous signal attenuation method. This method provides a new, convenient
approximation formalism for analyzing PFG anomalous diffusion experiments.


title:
Non-trivial reputation effects on social decision making in virtual
  environment

abstract:
  Reputation systems are currently used, often with success, to ensure the
functioning of online services as well as of e-commerce sites. Despite the
relationship between reputation and material cooperative behaviours is quite
supported, less obvious appears the relationship with informative behaviours,
which are crucial for the transmission of reputational information and
therefore for the maintenance of cooperation among individuals. The purpose of
this study was to verify how reputation affects cooperation dynamics in virtual
environment, within a social dilemma situation (i.e., where there are
incentives to act selfishly). The results confirm that reputation can activate
prosocial conducts, however it highlights also the limitations and distortions
that reputation can create.


title: H$_\alpha$-activity and ages for stars in the SARG survey

abstract:
  Stellar activity influences radial velocity (RV) measurements and can also
mimic the presence of orbiting planets. As part of the search for planets
around the components of wide binaries performed with the SARG High Resolution
Spectrograph at the TNG, it was discovered that HD 200466A shows strong
variation in RV that is well correlated with the activity index based on
H$_\alpha$. We used SARG to study the H$_\alpha$ line variations in each
component of the binaries and a few bright stars to test the capability of the
H$_\alpha$ index of revealing the rotation period or activity cycle. We also
analysed the relations between the average activity level and other physical
properties of the stars. We finally tried to reveal signals in the RVs that are
due to the activity. At least in some cases the variation in the observed RVs
is due to the stellar activity. We confirm that H$_\alpha$ can be used as an
activity indicator for solar-type stars and as an age indicator for stars
younger than 1.5 Gyr.


title:
Compressive Computed Tomography Reconstruction through Denoising
  Approximate Message Passing

abstract:
  X-ray Computed Tomography (CT) reconstruction from a sparse number of views
is a useful way to reduce either the radiation dose or the acquisition time,
for example in fixed-gantry CT systems, however this results in an ill-posed
inverse problem whose solution is typically computationally demanding.
Approximate Message Passing (AMP) techniques represent the state of the art for
solving under-sampling Compressed Sensing problems with random linear
measurements but there are still not clear solutions on how AMP should be
modified and how it performs with real world problems. This paper investigates
the question of whether we can employ an AMP framework for real sparse view CT
imaging? The proposed algorithm for approximate inference in tomographic
reconstruction incorporates a number of advances from within the AMP community,
resulting in the Denoising Generalized Approximate Message Passing CT algorithm
(D-GAMP-CT). Specifically, this exploits the use of sophisticated image
denoisers to regularize the reconstruction. While in order to reduce the
probability of divergence the (Radon) system and Poisson non-linear noise model
are treated separately, exploiting the existence of efficient preconditioners
for the former and the generalized noise modelling in GAMP for the latter.
Experiments with simulated and real CT baggage scans confirm that the
performance of the proposed algorithm outperforms statistical CT optimization
solvers.

categories: cs.DS math.OC physics.comp-ph physics.med-ph


title: Trade-off between speed and cost in shortcuts to adiabaticity

abstract:
  Achieving effectively adiabatic dynamics is a ubiquitous goal in almost all
areas of quantum physics. Here, we study the speed with which a quantum system
can be driven when employing transitionless quantum driving. As a main result,
we establish a rigorous link between this speed, the quantum speed limit, and
the (energetic) cost of implementing such a shortcut to adiabaticity.
Interestingly, this link elucidates a trade-off between speed and cost, namely
that instantaneous manipulation is impossible as it requires an infinite cost.
These findings are illustrated for two experimentally relevant systems - the
parametric oscillator and the Landau-Zener model - which reveal that the
spectral gap governs the quantum speed limit as well as the cost for realizing
the shortcut.


title:
Counter-propagating spontaneous four wave mixing: photon-pair
  factorability and ultra-narrowband single photon

abstract:
  We introduce a new kind of spontaneous four wave mixing process for the
generation of photon pairs, in which the four waves involved counter-propagate
in a guided-wave \chi^{(3)} medium; we refer to this process as
counter-propagating spontaneous four wave mixing (CP-SFWM). We show that for
the simplest CP-SFWM source, in which all waves propagate in the same
polarization and transverse mode and in which self- and cross-phase modulation
effects are negligible, phasematching is attained automatically regardless of
dispersion in the fiber or waveguide. Furthermore, we show that in two distinct
versions of this source (both pumps pulsed, or one pump pulsed and the
remaining one monochromatic), the two-photon state is automatically factorable
provided that the length of the nonlinear medium exceeds a certain threshold,
easily achievable in practice since this threshold length tends to be in the
range of mm to cm. We also show that if one of the pumps approaches the
monochromatic limit, and for a sufficient nonlinear medium length, the
bandwidth of one of the two photons in a given pair may be reduced to the level
of MHz, compatible with electronic transitions for the implementation of
atom-photon interfaces, without the use of optical cavities.


title: Collective Intelligence Heuristic: An Experimental Evidence

abstract:
  The main intreest of this study was to investigate the phenomenon of
collective intelligence in an anonymous virtual environment developed for this
purpose. In particular, we were interested in studiyng how dividing a fixed
community in different group size, which, in different phases of the
experiment, works to solve tasks of different complexity, influences the social
problem solving process. The experiments, which have involved 216 university
students, showed that the cooperative behaviour is stronger in small groups
facing complex tasks: the cooperation probability negatively correlated with
both the group size and easiness of task. Individuals seem to activate a
collective intelligence heuristics when the problem is too complex. Some
psychosocial variables were considered in order to check how they affect the
cooperative behaviour of participants, but they do not seem to have a
significant impact on individual cooperation probability, supporting the idea
that a partial de-individualization operates in virtual environments.


title: Benchmark of GW approaches for the GW100 testset

abstract:
  For the recent GW100 test set of molecular ionization energies, we present a
comprehensive assessment of different GW methodologies: fully self-consistent
GW (scGW), quasiparticle self-consistent GW (qsGW), partially self-consistent
GW0 (scGW0), perturbative GW (G0W0) and optimized G0W0 based on the
minimization of the deviation from the straight-line error (DSLE-minimized GW).
We compare our GW calculations to coupled-cluster singles, doubles, and
perturbative triples [CCSD(T)] reference data for GW100. We find scGW and qsGW
ionization energies in excellent agreement with CCSD(T), with discrepancies
typically smaller than 0.3 eV (scGW) respectively 0.2 eV (qsGW). For scGW0 and
G0W0 the deviation from CCSD(T) is strongly dependent on the starting point. We
further relate the discrepancy between the GW ionization energies and CCSD(T)
to the deviation from straight line error (DSLE). In DSLE-minimized GW
calculations, the DSLE is significantly reduced, yielding a systematic
improvement in the description of the ionization energies.


title:
Passivity-Based Distributed Optimization with Communication Delays Using
  PI Consensus Algorithm

abstract:
  In this paper, we address a class of distributed optimization problems in the
presence of inter-agent communication delays based on passivity. We first focus
on unconstrained distributed optimization and provide a passivity-based
perspective for distributed optimization algorithms. This perspective allows us
to handle communication delays while using scattering transformation. Moreover,
we extend the results to constrained distributed optimization, where it is
shown that the problem is solved by just adding one more feedback loop of a
passive system to the solution of the unconstrained ones. We also show that
delays can be incorporated in the same way as the unconstrained problems.
Finally, the algorithm is applied to a visual human localization problem using
a pedestrian detection algorithm.


title: War-Algorithm Accountability

abstract:
  In this briefing report, we introduce a new concept (war algorithms) that
elevates algorithmically-derived choices and decisions to a, and perhaps the,
central concern regarding technical autonomy in war. We thereby aim to shed
light on and recast the discussion regarding autonomous weapon systems. We
define war algorithm as any algorithm that is expressed in computer code, that
is effectuated through a constructed system, and that is capable of operating
in relation to armed conflict. In introducing this concept, our foundational
technological concern is the capability of a constructed system, without
further human intervention, to help make and effectuate a decision or choice of
a war algorithm. Distilled, the two core ingredients are an algorithm expressed
in computer code and a suitably capable constructed system. Through that lens,
we link international law and related accountability architectures to relevant
technologies. We sketch a three-part (non-exhaustive) approach that highlights
traditional and unconventional accountability avenues. We focus largely on
international law because it is the only normative regime that purports, in key
respects but with important caveats, to be both universal and uniform. By not
limiting our inquiry only to weapon systems, we take an expansive view, showing
how the broad concept of war algorithms might be susceptible to regulation, and
how those algorithms might already fit within the existing regulatory system
established by international law.


title:
Relative energy gap for harmonic maps of Riemann surfaces into real
  analytic Riemannian manifolds

abstract:
  We extend the well-known Sacks-Uhlenbeck energy gap result (1981) for
harmonic maps from closed Riemann surfaces into closed Riemannian manifolds
from the case of maps with small energy (thus near a constant map), to the case
of harmonic maps with high absolute energy but small energy relative to a
reference harmonic map.


title: Scaling in light scattering by sharp conical metal tips

abstract:
  Using the electrostatic approximation, we analyze electromagnetic fields
scattered by sharp conical metal tips, which are illuminated with light
polarized along the tip axis. We establish scaling relations for the scattered
field amplitude and phase, whose validity is verified with numerical
simulations. Analytic expressions for the wavelength, at which the scattered
field near the tip changes its direction, and field decay near the tip
extremity are obtained, relating these characteristics to the cone angle and
metal permittivity. The results obtained have important implications to various
tip-enhanced phenomena, ranging from Raman and scattering near-field imaging to
photoemission spectroscopy and nano-optical trapping.


title: Degree of the Gauss map and curvature integrals for closed hypersurfaces

abstract:
  Given a unit vector field on a closed Euclidean hypersurface, we define a map
from the hypersurface to a sphere in the Euclidean space. This application
allows us to exhibit a list of topological invariants which combines the second
fundamental form of the hypersurface and the vector field itself. We show how
these invariants can be used as obstructions to certain codimension one
foliations.


title:
Direct Search for keV Sterile Neutrino Dark Matter with a Stable
  Dysprosium Target

abstract:
  We investigate a new method to search for keV-scale sterile neutrinos that
could account for Dark Matter. Neutrinos trapped in our galaxy could be
captured on stable $^{163}$Dy if their mass is greater than 2.83 keV. Two
experimental realizations are studied, an integral counting of $^{163}$Ho atoms
in dysprosium-rich ores and a real-time measurement of the emerging electron
spectrum in a dysprosium-based detector. The capture rates are compared to the
solar neutrino and radioactive backgrounds. An integral counting experiment
using several kilograms of $^{163}$Dy could reach a sensitivity for the
sterile-to-active mixing angle $\sin^2\theta_{e4}$ of $10^{-5}$ significantly
exceeding current laboratory limits. Mixing angles as low as $\sin^2\theta_{e4}
\sim 10^{-7}$ / $\rm m_{^{163}\rm Dy}\rm{(ton)}$ could possibly be explored
with a real-time experiment.


title: Analog computing using reflective plasmonic metasurfaces

abstract:
  Motivated by the recent renewed interest in compact analog computing using
light and metasurfaces (Silva, A. et al., Science 2014, 343, 160-163), we
suggest a practical approach to its realization that involves reflective
metasurfaces consisting of arrayed gold nanobricks atop a subwavelength-thin
dielectric spacer and optically-thick gold film, a configuration that supports
gap-surface plasmon resonances. Using well established numerical routines, we
demonstrate that these metasurfaces enable independent control of the light
phase and amplitude, and design differentiator and integrator metasurfaces
featuring realistic system parameters. Proof-of-principle experiments are
reported along with the successful realization of a high-quality poor-man's
integrator metasurface operating at the wavelength of 800 nm.


title:
Poking holes and cutting corners to achieve Clifford gates with the
  surface code

abstract:
  The surface code is currently the leading proposal to achieve fault-tolerant
quantum computation. Among its strengths are the plethora of known ways in
which fault-tolerant Clifford operations can be performed, namely, by deforming
the topology of the surface, by the fusion and splitting of codes and even by
braiding engineered Majorana modes using twist defects. Here we present a
unified framework to describe these methods, which can be used to better
compare different schemes, and to facilitate the design of hybrid schemes. Our
unification includes the identification of twist defects with the corners of
the planar code. This identification enables us to perform single-qubit
Clifford gates by exchanging the corners of the planar code via code
deformation. We analyse ways in which different schemes can be combined, and
propose a new logical encoding. We also show how all of the Clifford gates can
be implemented with the planar code without loss of distance using code
deformations, thus offering an attractive alternative to ancilla-mediated
schemes to complete the Clifford group with lattice surgery.


title:
A Very Bright, Very Hot, and Very Long Flaring Event from the M Dwarf
  Binary System DG CVn

abstract:
  On April 23, 2014, the Swift satellite responded to a hard X-ray transient
detected by its Burst Alert Telescope, which turned out to be a stellar flare
from a nearby, young M dwarf binary DG~CVn. We utilize observations at X-ray,
UV, optical, and radio wavelengths to infer the properties of two large flares.
The X-ray spectrum of the primary outburst can be described over the 0.3-100
keV bandpass by either a single very high temperature plasma or a nonthermal
thick-target bremsstrahlung model, and we rule out the nonthermal model based
on energetic grounds. The temperatures were the highest seen spectroscopically
in a stellar flare, at T$_{X}$ of 290 MK. The first event was followed by a
comparably energetic event almost a day later. We constrain the photospheric
area involved in each of the two flares to be $>$10$^{20}$ cm$^{2}$, and find
evidence from flux ratios in the second event of contributions to the white
light flare emission in addition to the usual hot, T$\sim$10$^{4}$K blackbody
emission seen in the impulsive phase of flares. The radiated energy in X-rays
and white light reveal these events to be the two most energetic X-ray flares
observed from an M dwarf, with X-ray radiated energies in the 0.3-10 keV
bandpass of 4$\times$10$^{35}$ and 9$\times$10$^{35}$ erg, and optical flare
energies at E$_{V}$ of 2.8$\times$10$^{34}$ and 5.2$\times$10$^{34}$ erg,
respectively. The results presented here should be integrated into updated
modelling of the astrophysical impact of large stellar flares on close-in
exoplanetary atmospheres.


title:
On SDP Method for Solving Canonical Dual Problem in Post Buckling of
  Large Deformed Elastic Beam

abstract:
  This paper presents a new methodology and algorithm for solving post buckling
problems of a large deformed elastic beam. The total potential energy of this
beam is a nonconvex functional, which can be used to model both pre- and
post-buckling phenomena. By using a canonical dual finite element method, a new
primal-dual semi-definite programming (PD-SDP) algorithm is presented, which
can be used to obtain all possible post-buckled solutions. Applications are
illustrated by several numerical examples with different boundary conditions.
We find that the global minimum solution of the nonconvex potential leads to a
stable configuration of the buckled beam, the local maximum solution leads to
the unbuckled state, and both of these two solutions are numerically stable.
However, the local minimum solution leads to an unstable buckled state, which
is very sensitive to axial compressive forces, thickness of beam, numerical
precision, and the size of finite elements. The method and algorithm proposed
in this paper can be used for solving general nonconvex variational problems in
engineering and sciences.


title:
Localization, local cohomology, and the b-function of a D-module with
  respect to a polynomial

abstract:
  Given a $D$-module $M$ generated by a single element, and a polynomial $f$,
one can construct several $D$-modules attached to $M$ and $f$ and can define
the notion of the (generalized) $b$-function following M. Kashiwara. These
modules are closely related to the localization and the local cohomology of
$M$. We show that the $b$-function, if it exists, controls these modules and
present general algorithms for computing these modules and the $b$-function (if
it exists) without any further assumptions. For these algorithms, we
reformulate the localization algorithm for $D$-modules.


title: The Pan-STARRS 1 Discoveries of five new Neptune Trojans

abstract:
  In this work we report the detection of seven Neptune Trojans (NTs) in the
Pan-STARRS 1 (PS1) survey. Five of these are new discoveries, consisting of
four L4 Trojans and one L5 Trojan. Our orbital simulations show that the L5
Trojan stably librates for only several million years. This suggests that the
L5 Trojan must be of recent capture origin. On the other hand, all four new L4
Trojans stably occupy the 1:1 resonance with Neptune for more than 1 Gyr. They
can, therefore, be of primordial origin. Our survey simulation results show
that the inclination width of the Neptune Trojan population should be between
$7^{\circ}$ and $27^{\circ}$ at $>$ 95% confidence, and most likely $\sim
11^{\circ}$. In this paper, we describe the PS1 survey, the Outer Solar System
pipeline, the confirming observations, and the orbital/physical properties of
the new Neptune Trojans.


title:
Influence of the Ion Coordination Number on Cation Exchange Reactions
  with Copper Telluride Nanocrystals

abstract:
  Cu2-xTe nanocubes were used as starting seeds to access metal telluride
nanocrystals by cation exchanges at room temperature. The coordination number
of the entering cations was found to play an important role in dictating the
reaction pathways. The exchanges with tetrahedrally coordinated cations (i.e.
with coordination number 4), such as Cd2+ or Hg2+, yielded monocrystalline CdTe
or HgTe nanocrystals with Cu2-xTe/CdTe or Cu2-xTe/HgTe Janus-like
heterostructures as intermediates. The formation of Janus-like architectures
was attributed to the high diffusion rate of the relatively small tetrahedrally
coordinated cations, which could rapidly diffuse in the Cu2-xTe NCs and
nucleate the CdTe (or HgTe) phase in a preferred region of the host structure.
Also, with both Cd2+ and Hg2+ ions the exchange led to wurtzite CdTe and HgTe
phases rather than the more stable zinc-blende ones, indicating that the anion
framework of the starting Cu2- xTe particles could be more easily deformed to
match the anion framework of the metastable wurtzite structures. As hexagonal
HgTe had never been reported to date, this represents another case of
metastable new phases that can only be accessed by cation exchange. On the
other hand, the exchanges involving octahedrally coordinated ions (i.e. with
coordination number 6), such as Pb2+ or Sn2+, yielded rock-salt polycrystalline
PbTe or SnTe nanocrystals with Cu2-xTe@PbTe or Cu2-xTe@SnTe core@shell
architectures at the early stages of the exchange process. In this case, the
octahedrally coordinated ions are probably too large to diffuse easily through
the Cu2-xTe structure: their limited diffusion rate restricts their initial
reaction to the surface of the nanocrystals, where cation exchange is initiated
unselectively, leading to core@shell architectures.


title:
Dimensional reduction in Bose-Einstein condensed clouds of atoms
  confined in tight potentials of any geometry and any interaction strength

abstract:
  Motivated by numerous experiments on Bose-Einstein condensed atoms which have
been performed in tight trapping potentials of various geometries (elongated
and/or toroidal/annular), we develop a general method which allows us to reduce
the corresponding three-dimensional Gross-Pitaevskii equation for the order
parameter into an effectively one-dimensional equation, taking into account the
interactions (i.e., treating the width of the transverse profile variationally)
and the curvature of the trapping potential. As an application of our model we
consider atoms which rotate in a toroidal trapping potential. We evaluate the
state of lowest energy for a fixed value of the angular momentum within various
approximations of the effectively one-dimensional model and compare our results
with the full solution of the three-dimensional problem, thus getting evidence
for the accuracy of our model.

categories: cond-mat.quant-gas nlin.PS physics.atom-ph quant-ph


title: Nonlinear model of ice surface softening during friction

abstract:
  The ice surface softening during friction is shown as a result of spontaneous
appearance of shear strain caused by external supercritical heating. This
transformation is described by the Kelvin-Voigt equation for viscoelastic
medium, by the relaxation equations of Landau-Khalatnikov-type and for heat
conductivity. The study reveals that the above-named equations formally
coincide with the synergetic Lorenz system, where the order parameter is
reduced to shear strain, stress acts as the conjugate field, and temperature
plays the role of a control parameter. Using the adiabatic approximation, the
stationary values of these quantities are derived. The examination of
dependence of the relaxed shear modulus on strain explains the ice surface
softening according to the first-order transition mechanism. The critical
heating rate is proportional to the relaxed value of the ice shear modulus and
inversely proportional to its typical value.


title:
Quantum Emitters near Layered Plasmonic Nanostructures: Decay Rate
  Contributions

abstract:
  We introduce a numerical framework for calculating decay rate contributions
when excited two-level quantum emitters are located near layered plasmonic
nanostructures, particularly emphasizing the case of plasmonic nanostructures
atop metal substrates where three decay channels exist: free space radiation,
Ohmic losses, and excitation of surface plasmon polaritons (SPPs). The
calculation of decay rate contributions is based on Huygen's equivalence
principle together with a near-field to far-field transformation of the local
electric field, thereby allowing us to discern the part of the electromagnetic
field associated with free propagating waves rather than SPPs. The methodology
is applied to the case of an emitter inside and near a gap-plasmon resonator,
emphasizing strong position and orientation dependencies of the total decay
rate, contributions of different decay channels, radiation patterns, and
directivity of SPP excitation.


title:
Modelling spatial heteroskedasticity by volatility modulated moving
  averages

abstract:
  Spatial heteroskedasticity refers to stochastically changing variances and
covariances in space. Such features have been observed in, for example, air
pollution and vegetation data. We study how volatility modulated moving
averages can model this by developing theory, simulation and statistical
inference methods. For illustration, we also apply our procedure to sea surface
temperature anomaly data from the International Research Institute for Climate
and Society.


title: Maximal Repetition and Zero Entropy Rate

abstract:
  Maximal repetition of a string is the maximal length of a repeated substring.
This paper investigates maximal repetition of strings drawn from stochastic
processes. Strengthening previous results, two new bounds for the almost sure
growth rate of maximal repetition are identified: an upper bound in terms of
conditional R\'enyi entropy of order $\gamma>1$ given a sufficiently long past
and a lower bound in terms of unconditional Shannon entropy ($\gamma=1$). Both
the upper and the lower bound can be proved using an inequality for the
distribution of recurrence time. We also supply an alternative proof of the
lower bound which makes use of an inequality for the expectation of subword
complexity. In particular, it is shown that a power-law logarithmic growth of
maximal repetition with respect to the string length, recently observed for
texts in natural language, may hold only if the conditional R\'enyi entropy
rate given a sufficiently long past equals zero. According to this observation,
natural language cannot be faithfully modeled by a typical hidden Markov
process, which is a class of basic language models used in computational
linguistics.


title:
Infrared complex refractive index of astrophysical ices exposed to
  cosmic rays simulated in the laboratory

abstract:
  In dense and cold regions of the interstellar medium (ISM), molecules may be
adsorbed onto dust grains to form the ice mantles. Once formed, they can be
processed by ionizing radiation coming from stellar or interstellar medium
leading to formation of several new molecules in the ice. Among the different
kind of ionizing radiation, cosmic rays play an important role in the
solid-phase chemistry because of the large amount of energy deposited in the
ices. The physicochemical changes induced by the energetic processing of
astrophysical ices are recorded in a intrinsic parameter of the matter called
complex refractive index (CRI). In this paper, we present for the first time a
catalogue containing 39 complex refractive indices (n, k) in the infrared from
2.0 - 16.6 micrometer for 13 different water-containing ices processed in
laboratory by cosmic ray analogs. The calculation was done by using the NKABS
(acronym of determination of N and K from ABSorbance data) code, which employs
the Lambert-Beer and Kramers-Kronig equations to calculate the values of n and
k. The results are also available at the website:
http://www1.univap.br/gaa/nkabs-database/data.htm. As test case, a
H2O:NH3:CO2:CH4 ice was employed in a radiative transfer simulation of a
prototoplanetary disk to show that these data are indispensable to reproduce
the spectrum of YSOs containing ices.


title:
The arithmeticity of a Kodaira Fibration is determined by its universal
  cover

abstract:
  Let $S \to C$ be a Kodaira fibration. Here we show that whether or not the
algebraic surface $S$ is defined over a number field depends only on the
biholomorphic class of its universal cover.


title:
On the Lack of a Radio Afterglow from Some Gamma-ray Bursts - Insight
  into Their Progenitors?

abstract:
  We investigate the intrinsic properties of a sample of bright (E_iso > 10^52
erg) gamma-ray bursts, comparing those with and without radio afterglows. We
find that the sample of bursts with no radio afterglows has a significantly
shorter mean intrinsic duration of the prompt gamma-ray radiation, and the
distribution of this duration is significantly different from those bursts with
a radio afterglow. Although the sample with no radio afterglow has on average
lower isotropic energy, the lack of radio afterglow does not appear to be a
result of simply energetics of the burst, but a reflection of a separate
physical phenomenon likely related to the circumburst density profile. We also
find a weak correlation between the isotropic gamma-ray energy and intrinsic
duration in the sample with no radio afterglow, but not in the sample which
have observed radio afterglows. We give possible explanations for why there may
exist a sample of GRBs with no radio afterglow depending on whether the radio
emission comes from the forward or reverse shock, and why these bursts appear
to have intrinsically shorter prompt emission durations. We discuss how our
results may have implications for progenitor models of GRBs.


title:
Bethe approach study of the mixed spin-1/2 and spin-5/2 Ising system in
  the presence of an applied magnetic field

abstract:
  The mixed spin-1/2 and spin-5/2 Ising model is investigated on the Bethe
lattice in the presence of a magnetic field $h$ via the recursion relations
method. A ground-state phase diagram is constructed which may be needful to
explore important regions of the temperature phase diagrams of a model. The
order-parameters, the corresponding response functions and internal energy are
thoroughly investigated in order to typify the nature of the phase transition
and to get the corresponding temperatures. So, in the absence of the magnetic
field, the temperature phase diagrams are displayed in the case of an equal
crystal-field on the $(k_{\textrm{B}}T/|J|, \,D/|J|)$ plane when $q=3,4$, $5$
and $6$. The model only exhibits the second-order phase transition for
appropriate values of physical parameters of a model.


title: Oscillations Beyond Three-Neutrino Mixing

abstract:
  The current status of the phenomenology of short-baseline neutrino
oscillations induced by light sterile neutrinos in the framework of 3+1 mixing
is reviewed.


title:
Adaptive phase estimation with two-mode squeezed-vacuum and parity
  measurement

abstract:
  A proposed phase-estimation protocol based on measuring the parity of a
two-mode squeezed-vacuum state at the output of a Mach-Zehnder interferometer
shows that the Cram\'{e}r-Rao sensitivity is sub-Heisenberg [Phys.\ Rev.\
Lett.\ {\bf104}, 103602 (2010)]. However, these measurements are problematic,
making it unclear if this sensitivity can be obtained with a finite number of
measurements. This sensitivity is only for phase near zero, and in this region
there is a problem with ambiguity because measurements cannot distinguish the
sign of the phase. Here, we consider a finite number of parity measurements,
and show that an adaptive technique gives a highly accurate phase estimate
regardless of the phase. We show that the Heisenberg limit is reachable, where
the number of trials needed for mean photon number $\bar{n}=1$ is approximately
one hundred. We show that the Cram\'{e}r-Rao sensitivity can be achieved
approximately, and the estimation is unambiguous in the interval ($-\pi/2,
\pi/2$).


title:
Similarity solution for a two-phase one-dimensional Stefan problem with
  a convective boundary condition and a mushy zone model

abstract:
  A two-phase solidification process for a one-dimensional semi-infinite
material is considered. It is assumed that it is ensued from a constant bulk
temperature present in the vicinity of the fixed boundary, which it is modelled
through a convective condition (Robin condition). The interface between the two
phases is idealized as a mushy region and it is represented following the model
of Solomon, Wilson and Alexiades. An exact similarity solution is obtained when
a restriction on data is verified, and it is analysed the relation between the
problem considered here and the problem with a temperature condition at the
fixed boundary. Moreover, it is proved that the solution to the problem with
the convective boundary condition converges to the solution to a problem with a
temperature condition when the heat transfer coefficient at the fixed boundary
goes to infinity, and it is given an estimation of the difference between these
two solutions. Results in this article complete and improve the ones obtained
in Tarzia, Compt. Appl. Math., 9 (1990), 201-211.


title:
Plasmonic metagratings for simultaneous determination of Stokes
  parameters

abstract:
  Measuring light's state of polarization is an inherently difficult problem,
since the phase information between orthogonal polarization states is typically
lost in the detection process. In this work, we bring to the fore the
equivalence between normalized Stokes parameters and diffraction contrasts in
appropriately designed phase-gradient birefringent metasurfaces and introduce a
concept of all-polarization birefringent metagratings. The metagrating, which
consists of three interweaved metasurfaces, allows one to easily analyze an
arbitrary state of light polarization by conducting simultaneous (i.e.,
parallel) measurements of the correspondent diffraction intensities that reveal
immediately the Stokes parameters of the polarization state under examination.
Based on plasmonic metasurfaces operating in reflection at the wavelength of
800 nm, we design and realize phase-gradient birefringent metasurfaces and the
correspondent metagrating, while experimental characterization of the
fabricated components convincingly demonstrates the expected functionalities.
We foresee the use of the metagrating in compact polarimetric setups at any
frequency regime of interest.


title:
A Method for Computing the Edge-Hyper-Wiener Index of Partial Cubes and
  an Algorithm for Benzenoid Systems

abstract:
  The edge-hyper-Wiener index of a connected graph $G$ is defined as $WW_e(G) =
\frac{1}{2}\sum_{\lbrace e,f\rbrace \subseteq E(G)}d(e,f) +
\frac{1}{2}\sum_{\lbrace e,f\rbrace \subseteq E(G)}d(e,f)^2$. We develop a
method for computing the edge-hyper-Wiener index of partial cubes, which
constitute a large class of graphs with a lot of applications. It is also shown
how the method can be applied to trees. Furthermore, an algorithm for computing
the edge-hyper-Wiener index of benzenoid systems is obtained. Finally, the
algorithm is used to correct already known closed formulas for the edge-Wiener
index and the edge-hyper-Wiener index of linear polyacenes.


title: MALL proof nets identify proofs modulo rule commutation

abstract:
  We show that the proof nets introduced in [Hughes & van Glabbeek 2003, 2005]
for MALL (Multiplicative Additive Linear Logic, without units) identify
cut-free proofs modulo rule commutation: two cut-free proofs translate to the
same proof net if and only if one can be obtained from the other by a
succession of rule commutations. This result holds with and without the mix
rule, and we extend it with cut.