title: Comparison of Cross-Validation Methods for Stochastic Block Models

abstract:
  We introduce a novel cross-validation method that we call latinCV and we
compare this method to other model selection methods using data generated from
a stochastic block model. Comparing latinCV to other cross-validation methods,
we show that latinCV performs similarly to a method described in
\cite{hoff2008modeling} and that latinCV has a significantly larger true model
recovery accuracy than the NCV method of \cite{chen2014network}. We also show
that the reason for this discrepancy is related to the larger variance of the
NCV estimate. Comparing latinCV to alternative model selection methods, we show
that latinCV performs better than information criteria AIC and BIC, as well as
the community detection method infomap and a routine that attempts to maximize
modularity. The simulation study in this paper includes a range of network
sizes and generative parameters for the stochastic block model that allow us to
examine the relationship between model selection accuracy and the size and
complexity of the model. Overall, latinCV performs more accurate model
selection, and avoids overfitting better than any of the other model selection
methods considered.


title: Approximation and Kernelization for Chordal Vertex Deletion

abstract:
  The Chordal Vertex Deletion (ChVD) problem asks to delete a minimum number of
vertices from an input graph to obtain a chordal graph. In this paper we
develop a polynomial kernel for ChVD under the parameterization by the solution
size, as well as poly(opt) approximation algorithm. The first result answers an
open problem of Marx from 2006 [WG 2006, LNCS 4271, 37-48].


title: Edge states as mediators of bypass transition in boundary-layer flows

abstract:
  The concept of edge state is investigated in the asymptotic suction boundary
layer in relation with the receptivity process to noisy perturbations and the
nucleation of turbulent spots. Edge tracking is first performed numerically,
without imposing any discrete symmetry, in a large computational domain
allowing for full spatial localisation of the perturbation velocity. The edge
state is a three-dimensional localised structure recurrently characterised by a
single low-speed streak that experiences erratic bursts and planar shifts. This
recurrent streaky structure is then compared with predecessors of individual
spot nucleation events, triggered by non-localised initial noise. The present
results suggest a nonlinear picture, rooted in dynamical systems theory, of the
nucleation process of turbulent spots in boundary-layer flows, in which the
localised edge state play the role of state-space mediator.


title:
Diagonalization and Many-Body Localization for a Disordered Quantum Spin
  Chain

abstract:
  We consider a weakly interacting quantum spin chain with random local
interactions. We prove that many-body localization follows from a physically
reasonable assumption that limits the extent of level attraction in the
statistics of eigenvalues. In a KAM-style construction, a sequence of local
unitary transformations is used to diagonalize the Hamiltonian by deforming the
initial tensor product basis into a complete set of exact many-body
eigenfunctions.


title:
MUST-CNN: A Multilayer Shift-and-Stitch Deep Convolutional Architecture
  for Sequence-based Protein Structure Prediction

abstract:
  Predicting protein properties such as solvent accessibility and secondary
structure from its primary amino acid sequence is an important task in
bioinformatics. Recently, a few deep learning models have surpassed the
traditional window based multilayer perceptron. Taking inspiration from the
image classification domain we propose a deep convolutional neural network
architecture, MUST-CNN, to predict protein properties. This architecture uses a
novel multilayer shift-and-stitch (MUST) technique to generate fully dense
per-position predictions on protein sequences. Our model is significantly
simpler than the state-of-the-art, yet achieves better results. By combining
MUST and the efficient convolution operation, we can consider far more
parameters while retaining very fast prediction speeds. We beat the
state-of-the-art performance on two large protein property prediction datasets.


title: Shaping neural circuits by high order synaptic interactions

abstract:
  Spike timing dependent plasticity (STDP) is believed to play an important
role in shaping the structure of neural circuits. Here we show that STDP
generates effective interactions between synapses of different neurons, which
were neglected in previous theoretical treatments, and can be described as a
sum over contributions from structural motifs. These interactions can have a
pivotal influence on the connectivity patterns that emerge under the influence
of STDP. In particular, we consider two highly ordered forms of structure: wide
synfire chains, in which groups of neurons project to each other sequentially,
and self connected assemblies. We show that high order synaptic interactions
can enable the formation of both structures, depending on the form of the STDP
function and the time course of synaptic currents. Furthermore, within a
certain regime of biophysical parameters, emergence of the ordered connectivity
occurs robustly and autonomously in a stochastic network of spiking neurons,
without a need to expose the neural network to structured inputs during
learning.


title: Variational optimization with infinite projected entangled-pair states

abstract:
  We present a scheme to perform an iterative variational optimization with
infinite projected entangled-pair states (iPEPS), a tensor network ansatz for a
two-dimensional wave function in the thermodynamic limit, to compute the ground
state of a local Hamiltonian. The method is based on a systematic summation of
Hamiltonian contributions using the corner transfer-matrix method. Benchmark
results for challenging problems are presented, including the 2D Heisenberg
model, the Shastry-Sutherland model, and the t-J model, which show that the
variational scheme yields considerably more accurate results than the
previously best imaginary time evolution algorithm, with a similar
computational cost and with a faster convergence towards the ground state.


title: Osmosis and thermodynamics explained by solute blocking

abstract:
  A solute-blocking model is presented that provides a kinetic explanation of
osmosis and ideal solution thermodynamics. It validates a diffusive model of
osmosis that is distinct from the traditional convective flow model of osmosis.
Osmotic equilibrium occurs when the fraction of water molecules in solution
matches the fraction of pure water molecules that have enough energy to
overcome the pressure difference. Solute-blocking also provides a kinetic
explanation for why Raoult's law and the other colligative properties depend on
the mole fraction (but not the size) of the solute particles, resulting in a
novel kinetic explanation for the entropy of mixing and chemical potential of
ideal solutions. Some of its novel predictions have been confirmed, others can
be tested experimentally or by simulation.


title:
Glass and Jamming Transitions: From Exact Results to Finite-Dimensional
  Descriptions

abstract:
  Despite decades of work, gaining a first-principle understanding of amorphous
materials remains an extremely challenging problem. However, recent theoretical
breakthroughs have led to the formulation of an exact solution in the
mean-field limit of infinite spatial dimension, and numerical simulations have
remarkably confirmed the dimensional robustness of some of the predictions.
This review describes these latest advances. More specifically, we consider the
dynamical and thermodynamic descriptions of hard spheres around the dynamical,
Gardner and jamming transitions. Comparing mean-field predictions with the
finite-dimensional simulations, we identify robust aspects of the description
and uncover its more sensitive features. We conclude with a brief overview of
ongoing research.


title: Consciousness is Pattern Recognition

abstract:
  This is a proof of the strong AI hypothesis, i.e. that machines can be
conscious. It is a phenomenological proof that pattern-recognition and
subjective consciousness are the same activity in different terms. Therefore,
it proves that essential subjective processes of consciousness are computable,
and identifies significant traits and requirements of a conscious system. Since
Husserl, many philosophers have accepted that consciousness consists of
memories of logical connections between an ego and external objects. These
connections are called "intentions." Pattern recognition systems are achievable
technical artifacts. The proof links this respected introspective philosophical
theory of consciousness with technical art. The proof therefore endorses the
strong AI hypothesis and may therefore also enable a theoretically-grounded
form of artificial intelligence called a "synthetic intentionality," able to
synthesize, generalize, select and repeat intentions. If the pattern
recognition is reflexive, able to operate on the set of intentions, and
flexible, with several methods of synthesizing intentions, an SI may be a
particularly strong form of AI. Similarities and possible applications to
several AI paradigms are discussed. The article then addresses some problems:
The proof's limitations, reflexive cognition, Searles' Chinese room, and how an
SI could "understand" "meanings" and "be creative."


title: Near-threshold production of heavy quarks with QQbar_threshold

abstract:
  We describe the QQbar_threshold library for computing the production cross
section of heavy quark-antiquark pairs near threshold at electron-positron
colliders. The prediction includes all presently known QCD, electroweak, Higgs,
and nonresonant corrections in the combined nonrelativistic and weak-coupling
expansion.


title:
Computing bulk and shear viscosities from simulations of fluids with
  dissipative and stochastic interactions

abstract:
  Exact values for bulk and shear viscosity are important to characterize a
fluid and they are a necessary input for a continuum description. Here we
present two novel methods to compute bulk viscosities by non-equilibrium
molecular dynamics (NEMD) simulations of steady-state systems with periodic
boundary conditions -- one based on frequent particle displacements and one
based on the application of external bulk forces with an inhomogeneous force
profile.
  In equilibrium simulations, viscosities can be determined from the stress
tensor fluctuations via Green-Kubo relations; however, the correct
incorporation of random and dissipative forces is not obvious. We discuss
different expressions proposed in the literature and test them at the example
of a dissipative particle dynamics (DPD) fluid.


title:
Automatic 3D liver location and segmentation via convolutional neural
  networks and graph cut

abstract:
  Purpose Segmentation of the liver from abdominal computed tomography (CT)
image is an essential step in some computer assisted clinical interventions,
such as surgery planning for living donor liver transplant (LDLT), radiotherapy
and volume measurement. In this work, we develop a deep learning algorithm with
graph cut refinement to automatically segment liver in CT scans. Methods The
proposed method consists of two main steps: (i) simultaneously liver detection
and probabilistic segmentation using 3D convolutional neural networks (CNNs);
(ii) accuracy refinement of initial segmentation with graph cut and the
previously learned probability map. Results The proposed approach was validated
on forty CT volumes taken from two public databases MICCAI-Sliver07 and
3Dircadb. For the MICCAI-Sliver07 test set, the calculated mean ratios of
volumetric overlap error (VOE), relative volume difference (RVD), average
symmetric surface distance (ASD), root mean square symmetric surface distance
(RMSD) and maximum symmetric surface distance (MSD) are 5.9%, 2.7%, 0.91%, 1.88
mm, and 18.94 mm, respectively. In the case of 20 3Dircadb data, the calculated
mean ratios of VOE, RVD, ASD, RMSD and MSD are 9.36%, 0.97%, 1.89%, 4.15 mm and
33.14 mm, respectively. Conclusion The proposed method is fully automatic
without any user interaction. Quantitative results reveal that the proposed
approach is efficient and accurate for hepatic volume estimation in a clinical
setup. The high correlation between the automatic and manual references shows
that the proposed method can be good enough to replace the time-consuming and
non-reproducible manual segmentation method.


title:
Statistical mechanics approach to the electric polarization and
  dielectric constant of band insulators

abstract:
  We develop a theory for the analytic computation of the free energy of band
insulators in the presence of a uniform and constant electric field. The two
key ingredients are a perturbation-like expression of the Wannier-Stark energy
spectrum of electrons and a modified statistical mechanics approach involving a
local chemical potential in order to deal with the unbounded spectrum and
impose the physically relevant electronic filling. At first order in the field,
we recover the result of King-Smith, Vanderbilt and Resta for the electric
polarization in terms of a Zak phase - albeit at finite temperature - and, at
second order, deduce a general formula for the electric susceptibility, or
equivalently for the dielectric constant. Advantages of our method are the
validity of the formalism both at zero and finite temperature and the easy
computation of higher order derivatives of the free energy. We verify our
findings on two different one-dimensional tight-binding models.


title:
Ultramassive dense early-type galaxies: velocity dispersions and number
  density evolution since z=1.6

abstract:
  In this paper we investigate the mass assembly history of ultramassive (Mstar
> 10^11Msun) dense (Sigma = Mstar/(2*pi*Re^2) > 2500 Msun/pc^2) early-type
galaxies (ETGs) over the last 9 Gyr. We have traced the evolution of the number
density rho of ultramassive dense ETGs and have compared their structural
(effective radius Re and stellar mass Mstar) and dynamical (velocity dispersion
sigma_e) parameters over the redshift range 0 < z < 1.6. We have derived the
number density at 1.6 < z < 1 from the MUNICS and GOODS-South surveys, while we
have used the COSMOS and SDSS spectroscopic surveys to probe the intermediate
and local redshift range. For the comparison of the dynamical and structural
parameters, we have collected the ultramassive dense ETGs at 1.2 < z < 1.6 for
which velocity dispersion measurements are available (11 ETGs). For 4 of them
we present unpublished estimates of sigma_e. We probe the intermediate redshift
range, and the local universe using the samples of ETGs by Saglia et al.
(2010), Zahid et al. (2015), and by Thomas et al. (2010). We find that the
number density of ultramassive dense ETGs evolves as rho(z) = K*(1 +
z)^(0.3\pm0.8) implying a decrease of ~ 25% of the population since z = 1.6. By
comparing the values of Re, Mstar, and sigma_e of ultramassive dense ETGs over
the range 0 < z < 1.6 we find that all the high-z ETGs have a counterpart in
the local universe. This implies either that the majority (~70%) of
ultramassive dense ETGs has already completed its assembly and its shaping at
<z> = 1.4, or that, if a significant fraction of them evolves in size, new
ultramassive dense ETGs must form at z < 1.5 to maintain their number density
almost constant. The difficulty into identify good progenitors for these new
dense ETGs at z < 1.5, and the stellar populations properties of local
ultramassive dense ETGs point toward the first hypothesis.


title: Una tentazione affascinante

abstract: We discuss several aspects of infinity in the history of mathematics.


title:
Applications of the KKM property to coincidence theorems, equilibrium
  problems, minimax inequalities and variational relation problems

abstract:
  In this paper, we establish coincidence-like results in the case when the
values of the correspondences are not convex. In order to do this, we define a
new type of correspondences, namely properly quasi-convex-like. Further, we
apply the obtained theorems to solve equilibrium problems and to establish a
minimax inequality. In the last part of the paper, we study the existence of
solutions for generalized vector variational relation problems. Our analysis is
based on the applications of the KKM principle. We establish existence theorems
involving new hypothesis and we improve the results of some recent papers.


title:
Marginalized Particle Filtering and Related Filtering Techniques as
  Message Passing

abstract:
  In this manuscript a factor graph approach is employed to investigate the
recursive filtering problem for a mixed linear/nonlinear state-space model,
i.e. for a model whose state vector can be partitioned in a linear state
variable (characterized by conditionally linear dynamics) and a non linear
state variable. Our approach allows us to show that: a) the factor graph
characterizing the considered filtering problem is not cycle free; b) in the
case of conditionally linear Gaussian systems, applying the sum-product rule,
together with different scheduling procedures for message passing, to this
graph results in both known and novel filtering techniques. In particular, it
is proved that, on the one hand, adopting a specific message scheduling for
forward only message passing leads to marginalized particle filtering in a
natural fashion; on the other hand, if iterative strategies for message passing
are employed, novel filtering methods, dubbed turbo filters for their
conceptual resemblance to the turbo decoding methods devised for concatenated
channel codes, can be developed.


title: Non-additivity of pair interactions in charged colloids

abstract:
  It is general wisdom that the pair potential of charged colloids in a liquid
may be closely approximated by a Yukawa interaction, as predicted by the
classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. We experimentally
determine the effective forces in a binary mixture of like-charged particles,
of species 1 and 2, with blinking optical tweezers. The measured forces are
consistent with a Yukawa pair potential but the (12) cross-interaction is not
equal to the geometric mean of the (11) and (22) like-interactions, as expected
from DLVO. The deviation is a function of the electrostatic screening length
and the size ratio, with the cross-interaction measured being consistently
weaker than DLVO predictions. The corresponding non-additivity parameter is
negative and grows in magnitude with increased size asymmetry.


title:
Tight Sum-of-Squares lower bounds for binary polynomial optimization
  problems

abstract:
  We give two results concerning the power of the Sum-of-Squares(SoS)/Lasserre
hierarchy. For binary polynomial optimization problems of degree $2d$ and an
odd number of variables $n$, we prove that $\frac{n+2d-1}{2}$ levels of the
SoS/Lasserre hierarchy are necessary to provide the exact optimal value. This
matches the recent upper bound result by Sakaue, Takeda, Kim and Ito.
  Additionally, we study a conjecture by Laurent, who considered the linear
representation of a set with no integral points. She showed that the
Sherali-Adams hierarchy requires $n$ levels to detect the empty integer hull,
and conjectured that the SoS/Lasserre rank for the same problem is $n-1$. We
disprove this conjecture and derive lower and upper bounds for the rank.


title: $C^{1,0}$ Foliation Theory

abstract:
  Transverse one dimensional foliations play an important role in the study of
codimension one foliations. In \cite{KR2}, the authors introduced the notion of
flow box decomposition of a 3-manifold $M$. This is a decomposition of $M$ that
reflects both the structure of a given codimension one foliation and that of a
given transverse flow.
  In this paper, flow box decompositions are used to extend some classical
foliation results to foliations that are not $C^2$. Enhancements of well-known
results of Calegari on smoothing leaves, Dippolito on Denjoy blowup of leaves,
and Tischler on approximations by fibrations are obtained. The methods
developed are not intrinsically 3-dimensional techniques, and should generalize
to prove corresponding results for codimension one foliations in
$n$-dimensional manifolds.


title:
Interplay of bias-driven charging and the vibrational Stark effect in
  molecular junctions

abstract:
  We observe large, reversible, bias driven changes in the vibrational energies
of PCBM, based on simultaneous transport and surface-enhanced Raman
spectroscopy (SERS) measurements on PCBM-gold junctions. A combination of
linear and quadratic shifts in vibrational energies with voltage is analyzed
and compared with similar measurements involving C60-gold junctions. A
theoretical model based on density functional theory (DFT) calculations
suggests that both a vibrational Stark effect and bias-induced charging of the
junction contribute to the shifts in vibrational energies. In the PCBM case, a
linear vibrational Stark effect is observed due to the permanent electric
dipole moment of PCBM. The vibrational Stark shifts shown here for PCBM
junctions are comparable to or larger than the charging effects that dominate
in C60 junctions.


title:
Development of HPLC-Orbitrap method for identification of N-bearing
  molecules in complex organic material relevant to planetary environments

abstract:
  Although the Cassini Spacecraft and the Huygens lander provided numerous
information about Titan atmospheric chemistry and the formation of its
aerosols, the exact composition of these aerosols still remains unknown. A
fruitful proxy to investigate these aerosols is the use of laboratory
experiments that allow producing and studying analogs of Titan aerosol, the
so35 called tholins. Even when produced in the laboratory, unveiling the exact
composition of the aerosol remains problematic due to the high complexity of
the material. Numerous advances have been recently made using high-resolution
mass spectrometry (HRMS) (Pernot et al. 2010, Somogyi et al. 2012, Gautier et
al. 2014) that allowed the separation of isobaric compounds and a robust
identification of chemical species composing tholins regarding their molecular
formulae. Nevertheless isomeric species cannot be resolved by a simple mass
measurement. We propose here an analysis of tholins by high performance liquid
chromatography (HPLC) coupled to HRMS to unveil this isomeric ambiguity for
some of the major tholins compounds. By comparing chromatograms obtained when
analyzing tholins and chemical standards, we strictly identified seven
molecules in our tholins samples: melamine, cyanoguanidine,
6-methyl-1,3,5-triazine-2,4-diamine, 2,4,6-triaminopyrimidine, 3-amino-
1,2,4-triazole, 3,5-Dimethyl-1,2,4-triazole and 2,4-diamino-1,3,5-triazine.
Several molecules, including hexamethylenetriamine (HMT) were not present at
detectable levels in our sample. The use for the first time of a coupled
HPLC-HRMS technique applied to tholins study demonstrated the interest of such
a technique compared to single high-resolution mass spectrometry for the study
of tholins composition.


title: Quantum weak values and logic, an uneasy couple

abstract:
  Quantum mechanical weak values of projection operators have been used to
answer which-way questions, e.g. to trace which arms in a multiple Mach-Zehnder
setup a particle may have traversed from a given initial to a prescribed final
state. I show that this procedure might lead to logical inconsistencies in the
sense that different methods used to answer composite questions, like Has the
particle traversed the way X or the way Y? , may result in different answers
depending on which methods are used to find the answer. I illustrate the
problem by considering some examples: the quantum pigeonhole framework of
Aharonov et al, the three-box problem, and Hardys paradox. To prepare the
ground for my main conclusion on the incompatibility in certain cases of weak
values and logic, I study the corresponding situation for strong/projective
measurements. In this case, no logical inconsistencies occur provided one is
always careful in specifying exactly to which ensemble or sample space one
refers. My results cast doubts on the utility of quantum weak values in
treating cases like the examples mentioned.


title: Homotopic properties of K\"ahler orbifolds

abstract:
  We prove the formality and the evenness of odd-degree Betti numbers for
compact K\"ahler orbifolds, by adapting the classical proofs for K\"ahler
manifolds. As a consequence, we obtain examples of symplectic orbifolds not
admitting any K\"ahler orbifold structure. We also review the known examples of
non-formal simply connected Sasakian manifolds, and produce an example of a
non-formal quasi-regular Sasakian manifold with Betti numbers $b_1=0$ and
$b_2\,> 1$.


title: Temperature chaos is a non-local effect

abstract:
  Temperature chaos plays a role in important effects, like for example memory
and rejuvenation, in spin glasses, colloids, polymers. We numerically
investigate temperature chaos in spin glasses, exploiting its recent
characterization as a rare-event driven phenomenon. The peculiarities of the
transformation from periodic to anti-periodic boundary conditions in spin
glasses allow us to conclude that temperature chaos is non-local: no bounded
region of the system causes it. We precise the statistical relationship between
temperature chaos and the free-energy changes upon varying boundary conditions.


title: Magnetic fields of young solar twins

abstract:
  The goal of this work is to study the magnetic fields of six young
solar-analogue stars both individually, and collectively, to search for
possible magnetic field trends with age. If such trends are found, they can be
used to understand magnetism in the context of stellar evolution of solar-like
stars and, the past of the Sun and the solar system. This is also important for
the atmospheric evolution of the inner planets, Earth in particular. We used
Stokes IV data from two different spectropolarimeters, NARVAL and HARPSpol. The
least-squares deconvolution multi-line technique was used to increase the
signal-to-noise ratio of the data. We then applied a modern Zeeman-Doppler
imaging code in order to reconstruct the magnetic topology of all stars and the
brightness distribution of one of our studied stars. Our results show a
significant decrease in the magnetic field strength and energy as the stellar
age increases from 100Myr to 250Myr while there is no significant age
dependence of the mean magnetic field strength for stars with ages 250-650Myr.
The spread in the mean field strength between different stars is comparable to
the scatter between different observations of individual stars. The meridional
field component has the weakest strength compared to the radial and azimuthal
field components in 15 out of the 16 magnetic maps. It turns out that 89-97% of
the magnetic field energy is contained in l=1-3. There is also no clear trend
with age and distribution of field energy into poloidal/toroidal and
axisymmetric/non-axisymmetric components within the sample. The two oldest
stars in this study do show a twice as strong octupole component compared to
the quadrupole component. This is only seen in one out of 13 maps of the
younger stars. One star, chi1 Ori displays two field polarity switches during
almost 5 years of observations suggesting a magnetic cycle length of either 2,
6 or 8 years.


title: Destination Prediction by Trajectory Distribution Based Model

abstract:
  In this paper we propose a new method to predict the final destination of
vehicle trips based on their initial partial trajectories. We first review how
we obtained clustering of trajectories that describes user behaviour. Then, we
explain how we model main traffic flow patterns by a mixture of 2d Gaussian
distributions. This yielded a density based clustering of locations, which
produces a data driven grid of similar points within each pattern. We present
how this model can be used to predict the final destination of a new trajectory
based on their first locations using a two step procedure: We first assign the
new trajectory to the clusters it mot likely belongs. Secondly, we use
characteristics from trajectories inside these clusters to predict the final
destination. Finally, we present experimental results of our methods for
classification of trajectories and final destination prediction on datasets of
timestamped GPS-Location of taxi trips. We test our methods on two different
datasets, to assess the capacity of our method to adapt automatically to
different subsets.


title: Demonstration of a self-pulsing photonic crystal Fano laser

abstract:
  Semiconductor lasers in use today rely on mirrors based on the reflection at
a cleaved facet or Bragg reflection from a periodic stack of layers. Here, we
demonstrate an ultra-small laser with a mirror based on the Fano resonance
between a continuum of waveguide modes and the discrete resonance of a
nanocavity. The Fano resonance leads to unique laser characteristics. Since the
Fano mirror is very narrow-band compared to conventional lasers, the laser is
single-mode and in particular, it can be modulated via the mirror. We show,
experimentally and theoretically, that nonlinearities in the mirror may even
promote the generation of a self-sustained train of pulses at gigahertz
frequencies, an effect that was previously only observed in macroscopic lasers.
Such a source is of interest for a number of applications within integrated
photonics.


title:
On stable rationality of some conic bundles and moduli spaces of Prym
  curves

abstract:
  We prove that a very general hypersurface of bidegree (2, n) in P^2 x P^2 for
n bigger than or equal to 2 is not stably rational, using Voisin's method of
integral Chow-theoretic decompositions of the diagonal and their preservation
under mild degenerations. At the same time, we also analyse possible ways to
degenerate Prym curves, and the way how various loci inside the moduli space of
stable Prym curves are nested. No deformation theory of stacks or sheaves of
Azumaya algebras like in recent work of Hasset-Kresch-Tschinkel is used, rather
we employ a more elementary and explicit approach via Koszul complexes, which
is enough to treat this special case.


title:
Asymptotic behavior of the growth-fragmentation equation with bounded
  fragmentation rate

abstract:
  We are interested in the large time behavior of the solutions to the
growth-fragmentation equation. We work in the space of integrable functions
weighted with the principal dual eigenfunction of the growth-fragmentation
operator. This space is the largest one in which we can expect convergence to
the steady size distribution. Although this convergence is known to occur under
fairly general conditions on the coefficients of the equation, we prove that it
does not happen uniformly with respect to the initial data when the
fragmentation rate in bounded. First we get the result for fragmentation
kernels which do not form arbitrarily small fragments by taking advantage of
the Dyson-Phillips series. Then we extend it to general kernels by using the
notion of quasi-compactness and the fact that it is a topological invariant.


title: Mapping the functional connectome traits of levels of consciousness

abstract:
  Examining task-free functional connectivity (FC) in the human brain offers
insights on how spontaneous integration and segregation of information relate
to human cognition, and how this organization may be altered in different
conditions, and neurological disorders. This is particularly relevant for
patients in disorders of consciousness (DOC) following severe acquired brain
damage and coma, one of the most devastating conditions in modern medical care.
We present a novel data-driven methodology, connICA, which implements
Independent Component Analysis (ICA) for the extraction of robust independent
FC patterns (FC-traits) from a set of individual functional connectomes,
without imposing any a priori data stratification into groups. We here apply
connICA to investigate associations between network traits derived from
task-free FC and cognitive/clinical features that define levels of
consciousness. Three main independent FC-traits were identified and linked to
consciousness-related clinical features. The first one represents the
functional configuration it is associated to a sedative (sevoflurane), the
overall effect of the pathology and the level of arousal. The second FC-trait
reflects the disconnection of the visual and sensory-motor connectivity
patterns. It also relates to the time since the insult and to the ability of
communicating with the external environment. The third FC-trait isolates the
connectivity pattern encompassing the fronto-parietal and the default-mode
network areas as well as the interaction between left and right hemispheres,
which are also associated to the awareness of the self and its surroundings.
Each FC-trait represents a distinct functional process with a role in the
degradation of conscious states of functional brain networks, shedding further
light on the functional subcircuits that get disrupted in severe brain-damage.


title:
Contactless Remote Induction of Shear Waves in Soft Tissues Using a
  Transcranial Magnetic Stimulation Device

abstract:
  This study presents the first observation of shear wave induced remotely
within soft tissues. It was performed through the combination of a transcranial
magnetic stimulation device and a permanent magnet. A physical model based on
Maxwell and Navier equations was developed. Experiments were performed on a
cryogel phantom and a chicken breast sample. Using an ultrafast ultrasound
scanner, shear waves of respective amplitude of 5 and 0.5 micrometers were
observed. Experimental and numerical results were in good agreement. This study
constitutes the framework of an alternative shear wave elastography method.


title: Effect of Electrical Filtering on Level Dependent ASE Noise

abstract:
  We derive an analytical model describing the effect of filtering on amplified
spontaneous emission noise during or after opto-electronic conversion. In
particular, we show that electrical filtering results in a further reduction of
the signal quality factor associated with an effective increase of the noise
levels and can lead to counter-intuitive dependencies of the measured signal
quality on the characteristics of the test setup. Closed form equations are
compared with numerical models and experiments, showing excellent agreement.


title: On Splits of Computably enumerable sets

abstract:
  Our focus will be on the computably enumerable (c.e.) sets and trivial,
non-trivial, Friedberg, and non-Friedberg splits of the c.e. sets. Every
non-computable set has a non-trivial Friedberg split. Moreover, this theorem is
uniform. V. Yu. Shavrukov recently answered the question which c.e. sets have a
non-trivial non-Friedberg splitting and we provide a different proof of his
result. We end by showing there is no uniform splitting of all c.e. sets such
that all non-computable sets are non-trivially split and, in addition, all sets
with a non-trivial non-Friedberg split are split accordingly.


title: Context-Aware Adaptive Framework for e-Health Monitoring

abstract:
  For improving e-health services, we propose a context-aware framework to
monitor the activities of daily living of dependent persons. We define a
strategy for generating long-term realistic scenarios and a framework
containing an adaptive monitoring algorithm based on three approaches for
optimizing resource usage. The used approaches provide a deep knowledge about
the person's context by considering: the person's profile, the activities and
the relationships between activities. We evaluate the performances of our
framework and show its adaptability and significant reduction in network,
energy and processing usage over a traditional monitoring implementation.


title: 3LP: a linear 3D-walking model including torso and swing dynamics

abstract:
  In this paper, we present a new model of biped locomotion which is composed
of three linear pendulums (one per leg and one for the whole upper body) to
describe stance, swing and torso dynamics. In addition to double support, this
model has different actuation possibilities in the swing hip and stance ankle
which could be widely used to produce different walking gaits. Without the need
for numerical time-integration, closed-form solutions help finding periodic
gaits which could be simply scaled in certain dimensions to modulate the motion
online. Thanks to linearity properties, the proposed model can provide a
computationally fast platform for model predictive controllers to predict the
future and consider meaningful inequality constraints to ensure feasibility of
the motion. Such property is coming from describing dynamics with joint torques
directly and therefore, reflecting hardware limitations more precisely, even in
the very abstract high level template space. The proposed model produces
human-like torque and ground reaction force profiles and thus, compared to
point-mass models, it is more promising for precise control of humanoid robots.
Despite being linear and lacking many other features of human walking like CoM
excursion, knee flexion and ground clearance, we show that the proposed model
can predict one of the main optimality trends in human walking, i.e. nonlinear
speed-frequency relationship. In this paper, we mainly focus on describing the
model and its capabilities, comparing it with human data and calculating
optimal human gait variables. Setting up control problems and advanced
biomechanical analysis still remain for future works.


title:
Application of USNO-B1.0 towards selecting objects with displaced blue
  and red components

abstract:
  We have conducted a feasibility study to determine the effectiveness of using
USNO-B1.0 data to preferentially detect objects with displaced red and blue
components. A procedure was developed to search catalogue entries for such
objects, which include M dwarfs paired with white dwarfs or with earlier
main-sequence stars, and galaxies with asymmetric colour distributions.
Residual differences between red and blue and infrared and blue scanned
emulsion images define vectors, which, when appropriately aligned and of
sufficient length, signal potential candidates. Test sample sets were analysed
to evaluate the effective discrimination of the technique. Over 91,000
USNO-B1.0 catalogue entries at points throughout the celestial sphere were then
filtered for acceptable combinations of entry observations and magnitudes and
the resulting total of about 17,000 entries was winnowed down to a little more
than 200 objects of interest. These were screened by visual examination of
photo images to a final total of 146 candidates. About one quarter of these
candidates coincide with SDSS data. Those constituents fall into two groups,
single and paired objects. SDSS identified several galaxies in the first group.
Regarding the second group, at least half of its members were tentatively
identified as main-sequence pairs, the greater portion being of widely
separated spectral types. Two white dwarf--main-sequence pairs were also
identified. Most importantly, the vectors formed from USNO-B1.0 residuals were
in alignment with corresponding SDSS pair position angles, thereby supporting
this work`s central thesis.


title:
The Perspectives of Democratic Decision-Making in the Information
  Society

abstract:
  In order to structure the debate on the democratic potentials of digital
information technology Hubertus Buchstein in 1996 created three ideal types,
net optimism, net pessimism and net neutrality. In this study the viability of
these positions is put under scrutiny from a current viewpoint.


title:
A new time-projecting controller based on 3LP model to recover
  intermittent pushes

abstract:
  In this paper, we present a new walking controller based on 3LP model. Taking
advantage of linear equations and closed-form solutions of 3LP, the proposed
controller can project the state of the robot at any time during the phase back
to a certain event for which, a discrete LQR controller is designed. After the
projection, a proper control policy is generated by the expert discrete
controller and used online. This projecting architecture reacts to disturbances
with minimal delay and compared to discrete controllers, it provides superior
performance in recovering intermittent external pushes. Further analysis of
closed-loop eigenvalues and disturbance rejection shows that the proposed
time-projecting controller has strong stabilization properties. Controllable
regions also show that the projecting architecture covers most of the maximal
controllable set of states. It is computationally much faster than model
predictive controllers, but still optimal.


title: A note on the statistical view of matrix completion

abstract:
  A very simple interpretation of matrix completion problem is introduced based
on statistical models. Combined with the well-known results from missing data
analysis, such interpretation indicates that matrix completion is still a valid
and principled estimation procedure even without the missing completely at
random (MCAR) assumption, which almost all of the current theoretical studies
of matrix completion assume.


title:
Entanglement, excitations and correlation effects in narrow zigzag
  graphene nanoribbons

abstract:
  We investigate the low-lying excitation spectrum and ground-state properties
of narrow graphene nanoribbons with zigzag edge configurations. Nanoribbons of
comparable widths have been synthesized very recently [P. Ruffieux, \emph{et
al.} Nature \textbf{531}, 489 (2016)], and their descriptions require more
sophisticated methods since in this regime conventional methods, like
mean-field or density-functional theory with local density approximation, fail
to capture the enhanced quantum fluctuations. Using the unbiased density-matrix
renormalization group algorithm we calculate the charge gaps with high accuracy
for different widths and interaction strengths and compare them with mean-field
results. It turns out that the gaps are much smaller in the former case due to
the proper treatment of quantum fluctuations. Applying the elements of quantum
information theory we also reveal the entanglement structure inside a ribbon
and examine the spectrum of subsystem density matrices to understand the origin
of entanglement. We examine the possibility of magnetic ordering and the effect
of magnetic field. Our findings are relevant for understanding the gap values
in different recent experiments and the deviations between them.


title: Schatten properties, nuclearity and minimality of shift invariant spaces

abstract:
  We extend Feichtinger's minimality property on smallest non-trivial
time-frequency shift invariant Banach spaces, to the quasi-Banach case.
Analogous properties are deduced for certain matrix classes.
  We use these results to prove that $\operatorname{Op}(a)$ is a Schatten-$q$
operator from $M^\infty$ to $M^p$ and $r$-nuclear operator from $M^\infty$ to
$M^r$ when $a\in M^r$ for suitable $p$, $q$ and $r$ in $(0,\infty ]$.


title: Unique reconstruction threshold for random jigsaw puzzles

abstract:
  A random jigsaw puzzle is constructed by arranging $n^2$ square pieces into
an $n \times n$ grid and assigning to each edge of a piece one of $q$ available
colours uniformly at random, with the restriction that touching edges receive
the same colour. We show that if $q = o(n)$ then with high probability such a
puzzle does not have a unique solution, while if $q \ge n^{1 + \varepsilon}$
for any constant $\varepsilon > 0$ then the solution is unique. This solves a
conjecture of Mossel and Ross (Shotgun assembly of labeled graphs,
arXiv:1504.07682).


title:
Structures of not-finitely graded Lie superalgebras related to
  generalized super-Virasoro algebras

abstract:
  This paper is devoted to investigating the structure theory of a class of
not-finitely graded Lie superalgebras related to generalized super-Virasoro
algebras. In particular, we completely determine the derivation algebras, the
automorphism groups and the second cohomology groups of these Lie
superalgebras.


title: Definability equals recognizability for graphs of bounded treewidth

abstract:
  We prove a conjecture of Courcelle, which states that a graph property is
definable in MSO with modular counting predicates on graphs of constant
treewidth if, and only if it is recognizable in the following sense:
constant-width tree decompositions of graphs satisfying the property can be
recognized by tree automata. While the forward implication is a classic fact
known as Courcelle's theorem, the converse direction remained open


title:
A half-normal distribution scheme for generating functions and the
  unexpected behavior of Motzkin paths

abstract:
  We present an extension of a theorem by Michael Drmota and Mich\`ele Soria
[Images and Preimages in Random Mappings, 1997] that can be used to identify
the limiting distribution for a class of combinatorial schemata. This is
achieved by determining analytical and algebraic properties of the associated
bivariate generating function. We give sufficient conditions implying a
half-normal limiting distribution, extending the known conditions leading to
either a Rayleigh, a Gaussian, or a convolution of the last two distributions.
We conclude with three natural appearances of such a limiting distribution in
the domain of Motzkin paths.


title: BigFCM: Fast, Precise and Scalable FCM on Hadoop

abstract:
  Clustering plays an important role in mining big data both as a modeling
technique and a preprocessing step in many data mining process implementations.
Fuzzy clustering provides more flexibility than non-fuzzy methods by allowing
each data record to belong to more than one cluster to some degree. However, a
serious challenge in fuzzy clustering is the lack of scalability. Massive
datasets in emerging fields such as geosciences, biology and networking do
require parallel and distributed computations with high performance to solve
real-world problems. Although some clustering methods are already improved to
execute on big data platforms, but their execution time is highly increased for
large datasets. In this paper, a scalable Fuzzy C-Means (FCM) clustering named
BigFCM is proposed and designed for the Hadoop distributed data platform. Based
on the map-reduce programming model, it exploits several mechanisms including
an efficient caching design to achieve several orders of magnitude reduction in
execution time. Extensive evaluation over multi-gigabyte datasets shows that
BigFCM is scalable while it preserves the quality of clustering.


title:
Weak mixing properties of interval exchange transformations and
  translation flows

abstract:
  Let $d >1$. In this paper we show that for an irreducible permutation $\pi$
which is not a rotation, the set of $[\lambda]\in \mathbb{P}_+^{d-1}$ such that
the interval exchange transformation $f([\lambda],\pi)$ is not weakly mixing
does not have full Hausdorff dimension. We also obtain an analogous statement
for translation flows. In particular, it strengthens the result of almost sure
weak mixing proved by G. Forni and the first author. We adapt here the
probabilistic argument developed in their paper in order to get some large
deviation results. We then show how the latter can be converted into estimates
on the Hausdorff dimension of the set of "bad" parameters in the context of
fast decaying cocycles, following a strategy developed by V. Delecroix and the
first author.


title:
CNO behaviour in planet-harbouring stars. I Nitrogen abundances in stars
  with planets

abstract:
  Carbon, nitrogen, and oxygen (CNO) are key elements in stellar formation and
evolution, and their abundances should also have a significant impact on
planetary formation and evolution. We present a detailed spectroscopic analysis
of 74 solar-type stars, 42 of which are known to harbour planets. We determine
the nitrogen abundances of these stars and investigate a possible connection
between N and the presence of planetary companions. We used VLT/UVES to obtain
high-resolution near-UV spectra of our targets. Spectral synthesis of the NH
band at 3360A was performed with the spectral synthesis codes MOOG and FITTING.
We identify several spectral windows from which accurate N abundance can be
obtained. Nitrogen distributions for stars with and without planets show that
planet hosts are nitrogen-rich when compared to single stars. However, given
the linear trend between [N/Fe] vs [Fe/H], this fact can be explained as being
due to the metal-rich nature of planet hosts. We conclude that reliable N
abundances can be derived for metal-rich solar type stars from the near UV
molecular band at 3360A. We confirm a linear trend between [N/Fe] and
metallicity expected from standard models of Galactic chemical evolution.


title:
Evidence for a correlation between mass accretion rates onto young stars
  and the mass of their protoplanetary disks

abstract:
  A relation between the mass accretion rate onto the central young star and
the mass of the surrounding protoplanetary disk has long been theoretically
predicted and observationally sought. For the first time, we have accurately
and homogeneously determined the photospheric parameters, mass accretion rate,
and disk mass for an essentially complete sample of young stars with disks in
the Lupus clouds. Our work combines the results of surveys conducted with
VLT/X-Shooter and ALMA. With this dataset we are able to test a basic
prediction of viscous accretion theory, the existence of a linear relation
between the mass accretion rate onto the central star and the total disk mass.
We find a correlation between the mass accretion rate and the disk dust mass,
with a ratio that is roughly consistent with the expected viscous timescale
when assuming an interstellar medium (ISM) gas-to-dust ratio. This confirms
that mass accretion rates are related to the properties of the outer disk. We
find no correlation between mass accretion rates and the disk mass measured by
CO isotopologues emission lines, possibly owing to the small number of measured
disk gas masses. This suggests that the mm-sized dust mass better traces the
total disk mass and that masses derived from CO may be underestimated, at least
in some cases.


title:
Generalized Vector Quasi-Equilibrium Problems Involving Relaxed
  Continuity of the Set-Valued Maps

abstract:
  In this paper, we study the existence of solutions for generalized vector
quasi-equilibrium problems. Firstly, we prove that in the case of Banach
spaces, the assumptions of continuity over correspondences can be weakened. The
theoretical analysis is based on fixed-point theorems. Secondly, we establish
new equilibrium theorems as applications of the KKM principle.


title:
Solvable structures for evolution PDEs admitting differential
  constraints

abstract:
  Solvable structures are exploited in order to find families of explicit
solutions to evolution PDEs admitting suitable differential constraints. The
effectiveness of the method is verified on several explicit examples.


title:
Constraining spatial variations of the fine structure constant using
  clusters of galaxies and Planck data

abstract:
  We propose an improved methodology to constrain spatial variations of the
fine structure constant using clusters of galaxies. We use the {\it Planck}
2013 data to measure the thermal Sunyaev-Zeldovich effect at the location of
618 X-ray selected clusters. We then use a Monte Carlo Markov Chain algorithm
to obtain the temperature of the Cosmic Microwave Background at the location of
each galaxy cluster. When fitting three different phenomenological
parameterizations allowing for monopole and dipole amplitudes in the value of
the fine structure constant we improve the results of earlier analysis
involving clusters and the CMB power spectrum, and we also found that the
best-fit direction of a hypothetical dipole is compatible with the direction of
other known anomalies. Although the constraining power of our current datasets
do not allow us to test the indications of a fine-structure constant dipole
obtained though high-resolution optical/UV spectroscopy, our results do
highlight that clusters of galaxies will be a very powerful tool to probe
fundamental physics at low redshift.


title: Dust depletion of Ca and Ti in QSO absorption line systems

abstract:
  To explore the role of titanium- and calcium-dust depletion in gas in and
around galaxies we systematically study Ti/Ca abundance ratios in intervening
absorption-line systems at low and high redshift. We investigate
high-resolution optical spectra obtained by the UVES instrument at the Very
Large Telescope and spectroscopically analyze 34 absorption-line systems at
z<=0.5 to measure column densities (or limits) for CaII and TiII. We complement
our UVES data set with previously published absorption-line data on Ti/Ca for
redshifts up to z~3.8. Our absorber sample contains 110 absorbers (DLAs,
sub-DLAs & LLSs). We compare our Ti/Ca findings with results from the Milky Way
and the Magellanic Clouds and discuss the properties of Ti/Ca absorbers in the
general context of quasar absorption-line systems.Our analysis indicates that
there are two distinct populations of absorbers with either high or low Ti/Ca
ratios with a separation at [Ti/Ca}]~1. While the calcium dust depletion in
most of the absorbers appears to be severe, the titanium depletions are mild in
systems with high Ti/Ca ratios. The derived trend indicates that absorbers with
high Ti/Ca ratios have dust-to-gas ratios that are substantially lower than in
the Milky Way. We characterize the overall nature of the absorbers by
correlating Ti/Ca with other observables (e.g., metallicity, velocity-component
structure) and by modeling the ionization properties of singly-ionized Ca and
Ti in different environments. We conclude that CaII and TiII bearing
absorption-line systems trace predominantly neutral gas in the disks and inner
halo regions of galaxies, where the abundance of Ca and Ti reflects the local
metal and dust content of the gas. Our study suggests that the Ti/Ca ratio
represents a useful measure for the gas-to-dust ratio and overall metallicity
in intervening absorption-line systems.


title:
IRAS 16253-2429: the First Proto-Brown Dwarf Binary Candidate Identified
  through Dynamics of Jets

abstract:
  The formation mechanism of brown dwarfs (BDs) is one of the long-standing
problems in star formation because the typical Jeans mass in molecular clouds
is too large to form these substellar objects. To answer this question, it is
crucial to study a BD at the embedded phase. IRAS 16253-2429 is classified as a
very low luminosity object (VeLLO) with internal luminosity 0.1 Lsun. VeLLOs
are believed to be very low-mass protostars or even proto-BDs. We observed the
jet/outflow driven by IRAS 16253-2429 in CO (2-1), (6-5), and (7-6) using the
IRAM 30 m and APEX telescopes and the SMA in order to study its dynamical
features and physical properties. Our SMA map reveals two protostellar jets,
indicating the existence of a proto-binary system as implied by the precessing
jet detected in H2 emission. We detect a wiggling pattern in the
position-velocity diagrams along the jet axes, which is likely due to the
binary orbital motion. Based on this, we derive the current mass of the binary
as ~0.032 Msun. Given the low envelope mass, IRAS 16253-2429 will form a binary
that probably consist of one or two BDs. Furthermore, we found that the outflow
force as well as the mass accretion rate are very low based on the
multi-transition CO observations, which suggests that the final masses of the
binary components are at the stellar/substellar boundary. Since IRAS 16253 is
located in an isolated environment, we suggest that BDs can form through
fragmentation and collapse like low-mass stars.


title:
The SM extensions with additional light scalar singlet,
  nonrenormalizable Yukawa interactions and $(g-2)_{\mu}$

abstract:
  We consider the SM extension with additional light real singlet scalar,
right-handed neutrino and nonrenormalizable Yukawa interaction for the first
two generations. We show that the proposed model can explain the observed $(g -
2)$ muon anomaly. Phenomenological consequences as flavour violating decays
$\tau \rightarrow \mu\mu\mu, \mu \mu e,
  \mu e e $ are briefly discussed. We also propose the $U_R(1)$ gauge
generalization of the SM with complex scalar singlet and nonzero right-handed
charges for the first two generations.


title: Analytic approach for reflected Brownian motion in the quadrant

abstract:
  Random walks in the quarter plane are an important object both of
combinatorics and probability theory. Of particular interest for their study,
there is an analytic approach initiated by Fayolle, Iasnogorodski and Malyshev,
and further developed by the last two authors of this note. The outcomes of
this method are explicit expressions for the generating functions of interest,
asymptotic analysis of their coefficients, etc. Although there is an important
literature on reflected Brownian motion in the quarter plane (the continuous
counterpart of quadrant random walks), an analogue of the analytic approach has
not been fully developed to that context. The aim of this note is twofold: it
is first an extended abstract of two recent articles of the authors of this
paper, which propose such an approach; we further compare various aspects of
the discrete and continuous analytic approaches.


title: Fluids, Elasticity, Geometry, and the Existence of Wrinkled Solutions

abstract:
  We are concerned with underlying connections between fluids, elasticity,
isometric embedding of Riemannian manifolds, and the existence of wrinkled
solutions of the associated nonlinear partial differential equations. In this
paper, we develop such connections for the case of two spatial dimensions, and
demonstrate that the continuum mechanical equations can be mapped into a
corresponding geometric framework and the inherent direct application of the
theory of isometric embeddings and the Gauss-Codazzi equations through examples
for the Euler equations for fluids and the Euler-Lagrange equations for elastic
solids. These results show that the geometric theory provides an avenue for
addressing the admissibility criteria for nonlinear conservation laws in
continuum mechanics.


title: Core congestion is inherent in hyperbolic networks

abstract:
  We investigate the impact the negative curvature has on the traffic
congestion in large-scale networks. We prove that every Gromov hyperbolic
network $G$ admits a core, thus answering in the positive a conjecture by
Jonckheere, Lou, Bonahon, and Baryshnikov, Internet Mathematics, 7 (2011) which
is based on the experimental observation by Narayan and Saniee, Physical Review
E, 84 (2011) that real-world networks with small hyperbolicity have a core
congestion. Namely, we prove that for every subset $X$ of vertices of a
$\delta$-hyperbolic graph $G$ there exists a vertex $m$ of $G$ such that the
disk $D(m,4 \delta)$ of radius $4 \delta$ centered at $m$ intercepts at least
one half of the total flow between all pairs of vertices of $X$, where the flow
between two vertices $x,y\in X$ is carried by geodesic (or quasi-geodesic)
$(x,y)$-paths. A set $S$ intercepts the flow between two nodes $x$ and $y$ if
$S$ intersect every shortest path between $x$ and $y$. Differently from what
was conjectured by Jonckheere et al., we show that $m$ is not (and cannot be)
the center of mass of $X$ but is a node close to the median of $X$ in the
so-called injective hull of $X$. In case of non-uniform traffic between nodes
of $X$ (in this case, the unit flow exists only between certain pairs of nodes
of $X$ defined by a commodity graph $R$), we prove a primal-dual result showing
that for any $\rho>5\delta$ the size of a $\rho$-multi-core (i.e., the number
of disks of radius $\rho$) intercepting all pairs of $R$ is upper bounded by
the maximum number of pairwise $(\rho-3\delta)$-apart pairs of $R$.


title: A Passage-of-time Model of the Cerebellar Purkinje Cell

abstract:
  The cerebellar Purkinje cell controlling eyeblinks can learn, remember and
reproduce the interstimulus interval in a classical conditioning paradigm.
Given temporally separated inputs, the cerebellar Purkinje cell learns to pause
its tonic inhibition of a motor pathway with high temporal precision so that an
overt blink occurs at the right time. Most models relegate the Purkinje cell's
passage-of-time representation to afferent granule cells, a subpopulation of
which is supposedly selected for synaptic depression in order to make the
Purkinje cell pause. However, granule cell models have recently faced two
crucial challenges: 1) bypassing granule cells and directly stimulating the
Purkinje cell's pre-synaptic fibers during training still produces a well-timed
pause, and 2) the Purkinje cell can reproduce the learned pause, invariant to
the temporal structure of probe stimulation. Here, we present a passage-of-time
model which is internal to the Purkinje cell and is invariant to probe
structure. The model accurately simulates the Purkinje cell learning mechanism
and makes testable electrophysiological predictions. Importantly, the model is
a numerical proof-of-principle for a biological learning mechanism which does
not rely on changes of synaptic strength.


title:
Complete Study of Hadroproduction of a $\Upsilon$ Meson Associated with
  a Prompt $J/\psi$

abstract:
  We present the first complete study of $\Upsilon$ and prompt $J/\psi$
production from single-parton scattering, including the complete
$\mathcal{O}(\alpha_S^6)$ color-singlet contribution, the
$\mathcal{O}(\alpha_S^2\alpha^2)$ electroweak contribution, the complete
nonrelativistic S-wave and P-wave color-octet contribution as well as the
feeddown contribution. Our study was motivated by the recent evidence reported
by D0 Collaboration of prompt $J/\psi$ and $\Upsilon$ simultaneous production
at the Tevatron. With our complete evaluation, we are able to refine the
determination of the double parton scattering contribution made by D0
Collaboration. We find that the effective cross section characterizing the
importance of double-parton scatterings is $\sigma_{\rm eff}\le 8.2$ mb at
$68\%$ confidence level from the D0 measurement.


title:
A Critical Experimental Test of Synchrotron Radiation Theory with 3rd
  Generation Light Source

abstract:
  A recent "beam splitting" experiment at LCLS apparently demonstrated that
after a microbunched electron beam is kicked on a large angle compared to the
divergence of the FEL radiation, the microbunching wave front is readjusted
along the new direction of motion of the kicked beam. Therefore, coherent
radiation from an undulator placed after the kicker is emitted along the kicked
direction without suppression. This strong emission of coherent undulator
radiation in the kicked direction cannot be explained in the framework of
conventional synchrotron radiation theory. In a previous paper we explained
this puzzle. We demonstrated that, in accelerator physics, the coupling of
fields and particles is based, on the one hand, on the use of results from
particle dynamics treated according to the absolute time convention and, on the
other hand, on the use of Maxwell equations treated according to the standard
(Einstein) synchronization convention. Here lies the misconception which led to
the strong qualitative disagreement between theory and experiment. After the
"beam splitting" experiment at LCLS, it became clear that the conventional
theory of synchrotron radiation cannot ensure the correct description of
coherent and spontaneous emission from a kicked electron beam, nor the emission
from a beam with finite angular divergence, in an undulator or a bending
magnet. However, this result requires further experimental confirmation. In
this publication we propose an uncomplicated and inexpensive experiment to test
synchrotron radiation theory at 3rd generation light sources.


title: This House Proves that Debating is Harder than Soccer

abstract:
  During the last twenty years, a lot of research was conducted on the sport
elimination problem: Given a sports league and its remaining matches, we have
to decide whether a given team can still possibly win the competition, i.e.,
place first in the league at the end. Previously, the computational complexity
of this problem was investigated only for games with two participating teams
per game. In this paper we consider Debating Tournaments and Debating Leagues
in the British Parliamentary format, where four teams are participating in each
game. We prove that it is NP-hard to decide whether a given team can win a
Debating League, even if at most two matches are remaining for each team. This
contrasts settings like football where two teams play in each game since there
this case is still polynomial time solvable. We prove our result even for a
fictitious restricted setting with only three teams per game. On the other
hand, for the common setting of Debating Tournaments we show that this problem
is fixed parameter tractable if the parameter is the number of remaining rounds
$k$. This also holds for the practically very important question of whether a
team can still qualify for the knock-out phase of the tournament and the
combined parameter $k + b$ where $b$ denotes the threshold rank for qualifying.
Finally, we show that the latter problem is polynomial time solvable for any
constant $k$ and arbitrary values $b$ that are part of the input.


title: Asymptotic behaviour of high Gaussian minima

abstract:
  We investigate what happens when an entire sample path of a smooth Gaussian
process on a compact interval lies above a high level. Specifically, we
determine the precise asymptotic probability of such an event, the extent to
which the high level is exceeded, the conditional shape of the process above
the high level, and the location of the minimum of the process given that the
sample path is above a high level.


title: Appearance of Dusty Filaments at Different Viewing Angles

abstract:
  Context: In the last years, there have been many studies on the omnipresence
and structures of filaments in star-forming regions, as well as their role in
the process of star formation. Those filaments are normally identified as
elongated fibres across the plane of the sky. But how would we detect filaments
that are inclined? Aims: We aim to learn more about whether, and how, total
column density or dust temperature change with respect to the line of sight.
Such variations would enable observers to use dust observations to identify and
study filaments at any inclination and gain more insight on the distribution
and orientations of filaments within the Galactic plane. Methods: As a first
step, we perform numerical calculations on simple cylindrical models to
evaluate the influence of filament geometry on the average flux density. After
that, we apply our three-dimensional Monte Carlo dust radiative transfer code
on two models of star-forming regions and derive maps of effective total column
density and dust temperature at different viewing angles. Results: We see only
slight changes of average flux density for all cylinders we study. For our more
complex models, we find that the effective dust temperature is not sensitive to
viewing angle, while the total column density is strongly influenced, with
differences exceeding an order of magnitude. The variations are not injective
with the viewing angle and depend on the structure of the object. Conclusions:
We conclude that there is no single quantity in our analysis that can uniquely
trace the inclination and three-dimensional structure of a filament based on
dust observations alone. However, observing wide variations in total column
density at a given effective dust temperature is indicative of inclined
filaments.


title:
Damped wave systems on networks: Exponential stability and uniform
  approximations

abstract:
  We consider a damped linear hyperbolic system modelling the propagation of
pressure waves in a network of pipes. Well-posedness is established via
semi-group theory and the existence of a unique steady state is proven in the
absence of driving forces. Under mild assumptions on the network topology and
the model parameters, we show exponential stability and convergence to
equilibrium. This generalizes related results for single pipes and
multi-dimensional domains to the network context. Our proof of the exponential
stability estimate is based on a variational formulation of the problem, some
graph theoretic results, and appropriate energy estimates. The main arguments
are rather generic and can be applied also for the analysis of Galerkin
approximations. Uniform exponential stability can be guaranteed for the
resulting semi-discretizations under mild compatibility conditions on the
approximation spaces. A particular realization by mixed finite elements is
discussed and the theoretical results are illustrated by numerical tests in
which also bounds for the decay rate are investigated.


title: Vortex Nucleation in a Bose-Einstein Condensate: From the Inside Out

abstract:
  We observed a new mechanism for vortex nucleation in Bose-Einstein
condensates (BECs) subject to synthetic magnetic fields. We made use of a
strong synthetic magnetic field initially localized between a pair of merging
BECs to rapidly create vortices in the bulk of the merged condensate. Unlike
previous implementations and in agreement with our Gross-Pitaevskii equation
simulations, our dynamical process rapidly injects vortices into our system's
bulk, and with initial number in excess of the system's equilibrium vortex
number.


title: On Stability and Sojourn Time of Peer-to-Peer Queuing Systems

abstract:
  Recent development of peer-to-peer (P2P) services (e.g. streaming, file
sharing, and storage) systems introduces a new type of queue systems that
receive little attention before, where both job and server arrive and depart
randomly. Current study on these models focuses on the stability condition,
under exponential workload assumption. This paper extends existing result in
two aspects. In the first part of the paper we relax the exponential workload
assumption, and study the stability of systems with general workload
distribution. The second part of the paper focuses on the job sojourn time. An
upper bound and a lower bound for job sojourn time are investigated. We
evaluate tightness of the bounds by numerical analysis.


title:
A pathwise iterative approach to the extinction of branching processes
  with countably many types

abstract:
  We consider the extinction events of Galton-Watson processes with countably
infinitely many types. In particular, we construct truncated and augmented
Galton-Watson processes with finite but increasing sets of types. A pathwise
approach is then used to show that, under some sufficient conditions, the
corresponding sequence of extinction probability vectors converges to the
global extinction probability vector of the Galton-Watson processes with
countably infinitely many types. This gives rise to a number of iterative
methods for the computation of the global extinction probability vector.


title:
Production of the Doubly Charmed Baryons at the SELEX experiment -- The
  double intrinsic charm approach

abstract:
  The high production rate and $\langle x_{F} \rangle > 0.33$ of the doubly
charmed baryons measured by the SELEX experiment is not amenable to
perturbative QCD analysis. In this paper we calculate the production of the
doubly heavy baryons with the double intrinsic charm Fock states whose
existence is rigorously predicted by QCD. The production rate and the
longitudinal momentum distribution are both reproduced. We also show that the
production rates of the doubly charmed baryons and double $J/\psi $ production
observed by NA3 collaboration are comparable. Recent experimental results are
reviewed. The production cross section of the doubly charmed baryons at a
fixed-target experiment at the LHC is presented.


title:
Parameterized Complexity and Approximation Issues for the Colorful
  Components Problems

abstract:
  The quest for colorful components (connected components where each color is
associated with at most one vertex) inside a vertex-colored graph has been
widely considered in the last ten years. Here we consider two variants, Minimum
Colorful Components (MCC) and Maximum Edges in transitive Closure (MEC),
introduced in 2011 in the context of orthology gene identification in
bioinformatics. The input of both MCC and MEC is a vertex-colored graph. MCC
asks for the removal of a subset of edges, so that the resulting graph is
partitioned in the minimum number of colorful connected components; MEC asks
for the removal of a subset of edges, so that the resulting graph is
partitioned in colorful connected components and the number of edges in the
transitive closure of such a graph is maximized. We study the parameterized and
approximation complexity of MCC and MEC, for general and restricted instances.
  For MCC on trees we show that the problem is basically equivalent to Minimum
Cut on Trees, thus MCC is not approximable within factor $1.36 - \varepsilon$,
it is fixed-parameter tractable and it admits a poly-kernel (when the parameter
is the number of colorful components). Moreover, we show that MCC, while it is
polynomial time solvable on paths, it is NP-hard even for graphs with constant
distance to disjoint paths number. Then we consider the parameterized
complexity of MEC when parameterized by the number $k$ of edges in the
transitive closure of a solution (the graph obtained by removing edges so that
it is partitioned in colorful connected components). We give a fixed-parameter
algorithm for MEC paramterized by $k$ and, when the input graph is a tree, we
give a poly-kernel.


title: Semi-Supervised Representation Learning based on Probabilistic Labeling

abstract:
  In this paper, we present a new algorithm for semi-supervised representation
learning. In this algorithm, we first find a vector representation for the
labels of the data points based on their local positions in the space. Then, we
map the data to lower-dimensional space using a linear transformation such that
the dependency between the transformed data and the assigned labels is
maximized. In fact, we try to find a mapping that is as discriminative as
possible. The approach will use Hilber-Schmidt Independence Criterion (HSIC) as
the dependence measure. We also present a kernelized version of the algorithm,
which allows non-linear transformations and provides more flexibility in
finding the appropriate mapping. Use of unlabeled data for learning new
representation is not always beneficial and there is no algorithm that can
deterministically guarantee the improvement of the performance by exploiting
unlabeled data. Therefore, we also propose a bound on the performance of the
algorithm, which can be used to determine the effectiveness of using the
unlabeled data in the algorithm. We demonstrate the ability of the algorithm in
finding the transformation using both toy examples and real-world datasets.


title: Atmospheric Neutrinos

abstract:
  In view of the observation by IceCube of high-energy astrophysical neutrinos,
it is important to quantify the uncertainty in the background of atmospheric
neutrinos. There are two sources of uncertainty, the imperfect knowledge of the
spectrum and composition of the primary cosmic rays that produce the neutrinos
and the limited understanding of hadron production, including charm, at high
energy. This paper is an overview of both aspects.


title: Some variants of Lagrange's four squares theorem

abstract:
  Lagrange's four squares theorem is a classical theorem in number theory.
Recently, Z.-W. Sun found that it can be further refined in various ways. In
this paper we study some conjectures of Sun and obtain various refinements of
Lagrange's theorem. We show that any nonnegative integer can be written as
$x^2+y^2+z^2+w^2$ $(x,y,z,w\in\mathbb Z)$ with $x+y+z+w$ (or $x+y+z+2w$, or
$x+2y+3z+w$) a square (or a cube). Also, every $n=0,1,2,\ldots$ can be
represented by $x^2+y^2+z^2+w^2$ $(x,y,z,w\in\mathbb Z)$ with $x+y+3z$ (or
$x+2y+3z$) a square (or a cube), and each $n=0,1,2,\ldots$ can be written as
$x^2+y^2+z^2+w^2$ $(x,y,z,w\in\mathbb Z)$ with $(10w+5x)^2+(12y+36z)^2$ (or
$x^2y^2+9y^2z^2+9z^2x^2$) a square. We also provide an advance on the 1-3-5
conjecture of Sun. Our main results are proved by a new approach involving
Euler's four-square identity


title: Molecular hydrodynamics from memory kernels

abstract:
  The memory kernel for a tagged particle in a fluid, computed from molecular
dynamics simulations, decays algebraically as $t^{-3/2}$. We show how the
hydrodynamic Basset-Boussinesq force naturally emerges from this long-time tail
and generalize the concept of hydrodynamic added mass. This mass term is
negative in the present case of a molecular solute, at odds with incompressible
hydrodynamics predictions. We finally discuss the various contributions to the
friction, the associated time scales and the cross-over between the molecular
and hydrodynamic regimes upon increasing the solute radius.


title:
A universal mechanism generating clusters of differentiated loci during
  divergence-with-migration

abstract:
  Genome-wide patterns of genetic divergence reveal mechanisms of adaptation
under gene flow. Empirical data show that divergence is mostly concentrated in
narrow genomic regions. This pattern may arise because differentiated loci
protect nearby mutations from gene flow, but recent theory suggests this
mechanism is insufficient to explain the emergence of concentrated
differentiation during biologically realistic timescales. Critically, earlier
theory neglects an inevitable consequence of genetic drift: stochastic loss of
local genomic divergence. Here we demonstrate that the rate of stochastic loss
of weak local differentiation increases with recombination distance to a
strongly diverged locus and, above a critical recombination distance, local
loss is faster than local `gain' of new differentiation. Under high migration
and weak selection this critical recombination distance is much smaller than
the total recombination distance of the genomic region under selection.
Consequently, divergence between populations increases by net gain of new
differentiation within the critical recombination distance, resulting in
tightly-linked clusters of divergence. The mechanism responsible is the balance
between stochastic loss and gain of weak local differentiation, a mechanism
acting universally throughout the genome. Our results will help to explain
empirical observations and lead to novel predictions regarding changes in
genomic architectures during adaptive divergence.


title:
ALMA-resolved salt emission traces the chemical footprint and inner wind
  morphology of VY CMa

abstract:
  (abreviated) We aim to study the inner-wind structure (R<250 Rstar) of the
well-known red supergiant VY CMa. We analyse high spatial resolution
(~0".24x0".13) ALMA Science Verification (SV) data in band 7 in which four
thermal emission lines of gaseous sodium chloride (NaCl) are present at high
signal-to-noise ratio. For the first time, the NaCl emission in the inner wind
region of VY CMa is spatially resolved. The ALMA observations reveal the
contribution of up to four different spatial regions. The NaCl emission pattern
is different compared to the dust continuum and TiO2 emission already analysed
from the ALMA SV data. The emission can be reconciled with an axisymmetric
geometry, where the lower density polar/rotation axis has a position angle of
~50 degrees measured from north to east. However, this picture can not capture
the full morphological diversity, and discrete mass ejection events need to be
invoked to explain localized higher-density regions. The velocity traced by the
gaseous NaCl line profiles is significantly lower than the average wind
terminal velocity, and much slower than some of the fastest mass ejections,
signalling a wide range of characteristic speeds for the mass loss. Gaseous
NaCl is detected far beyond the main dust condensation region. Realising the
refractory nature of this metal halide, this hints at a chemical process
preventing all NaCl from condensing onto dust grains. We show that in the case
of the ratio of the surface binding temperature to the grain temperature being
~50, only some 10% of NaCl remains in gaseous form, while for lower values of
this ratio thermal desorption efficiently evaporates NaCl. Photodesorption by
stellar photons seems not to be a viable explanation for the detection of
gaseous NaCl at 220 Rstar from the central star, and instead, we propose
shock-induced sputtering driven by localized mass ejection events as
alternative.


title:
Inducing an Incipient Terahertz Finite Plasmonic Crystal in Coupled Two
  Dimensional Plasmonic Cavities

abstract:
  We measured a change in the current transport of an antenna-coupled,
multi-gate, GaAs/AlGaAs field-effect transistor when terahertz electromagnetic
waves irradiated the transistor and attribute the change to bolometric heating
of the electrons in the two-dimensional electron channel. The observed
terahertz absorption spectrum indicates coherence between plasmons excited
under adjacent biased device gates. The experimental results agree
quantitatively with a theoretical model we developed that is based on a
generalized plasmonic transmission line formalism and describes an evolution of
the plasmonic spectrum with increasing electron density modulation from
homogeneous to the crystal limit. These results demonstrate an electronically
induced and dynamically tunable plasmonic band structure.


title: A novel clustering algorithm for coverage a large scale in WSN

abstract:
  The applications require coverage of the whole monitored area for long
periods of time. Clustering is a way to reduce communications, minimize energy
consumption and organize messages among the cluster head and their members. The
message exchange of communication and data transmission between the different
sensor nodes must be minimized to keep and extended the lifetime of the network
because of limited energy resources of the sensors. In this paper, we take into
consideration the problem isolated nodes that are away from the cluster head
(CH) and by consequence or CH is not within the reach from these nodes. To
solve this problem, we propose O-LEACH (Orphan Low Energy Adaptive Clustering
Hierarchy) a routing protocol that takes into account the orphan nodes. Indeed,
a cluster member will be able to play the role of a gateway which allows the
joining of orphan nodes. Our contribution is to election a cluster head that
has enough energy for a better now to coordinate with these member nodes and
maintain the full coverage for applications which requires of useful data for
the entire area to be covered. The simulation results show that O-LEACH
performs better than LEACH in terms of connectivity rate, energy, scalability
and coverage.


title: Crystallization of self-propelled hard-discs : a new scenario

abstract:
  We experimentally study the crystallization of a monolayer of vibrated discs
with a built-in polar asymmetry, a model system of active liquids, and contrast
it with that of vibrated isotropic discs. Increasing the packing fraction
$\phi$, the quasi-continuous crystallization reported for isotropic discs is
replaced by a transition, or a crossover towards a "self-melting" crystal.
Increasing the packing fraction from the liquid phase, clusters of dense
hexagonally-ordered packed discs spontaneously form, melt, split and merge
leading to a highly intermittent and heterogeneous dynamics. The resulting
steady state cluster size distribution decreases monotonically. For packing
fraction larger than $\phi^*$, a few large clusters span the system size and
the cluster size distribution becomes non monotonic, the transition being
signed by a power-law. The system is however never dynamically arrested. The
clusters permanently melt from place to place forming droplets of active liquid
which rapidly propagate across the system. This state of affair remains up to
the highest possible packing fraction questioning the stability of the crystal
for active discs, unless at ordered close packing.


title: On the Price of Anarchy of Highly Congested Nonatomic Network Games

abstract:
  We consider nonatomic network games with one source and one destination. We
examine the asymptotic behavior of the price of anarchy as the inflow
increases. In accordance with some empirical observations, we show that, under
suitable conditions, the price of anarchy is asymptotic to one. We show with
some counterexamples that this is not always the case. The counterexamples
occur in very simple parallel graphs.


title: 3-D structures of planetary nebulae

abstract:
  Recent advances in the 3-D reconstruction of planetary nebulae are reviewed.
We include not only results for 3-D reconstructions, but also the current
techniques in terms of general methods and software. In order to obtain more
accurate reconstructions, we suggest to extend the widely used assumption of
homologous nebula expansion to map spectroscopically measured velocity to
position along the line of sight.


title:
Theory of the Robin quantum wall in a linear potential. II.
  Thermodynamic properties

abstract:
  A theoretical analysis of the thermodynamic properties of the Robin wall
characterized by the extrapolation length $\Lambda$ in the electric field
$\mathscr{E}$ that pushes the particle to the surface is presented both in the
canonical and two grand canonical representations and in the whole range of the
Robin distance with the emphasis on its negative values which for the
voltage-free configuration support negative-energy bound state. For the
canonical ensemble, the heat capacity at $\Lambda<0$ exhibits a nonmonotonic
behavior as a function of the temperature $T$ with its pronounced maximum
unrestrictedly increasing for the decreasing fields as $\ln^2\mathscr{E}$ and
its location being proportional to $(-\ln\mathscr{E})^{-1}$. For the
Fermi-Dirac distribution, the specific heat per particle $c_N$ is a
nonmonotonic function of the temperature too with the conspicuous extremum
being preceded on the $T$ axis by the plateau whose magnitude at the vanishing
$\mathscr{E}$ is defined as $3(N-1)/(2N)k_B$, with $N$ being a number of the
particles. The maximum of $c_N$ is the largest for $N=1$ and, similar to the
canonical ensemble, grows to infinity as the field goes to zero. For the
Bose-Einstein ensemble, a formation of the sharp asymmetric feature on the
$c_N$-$T$ dependence with the increase of $N$ is shown to be more prominent at
the lower voltages. This cusp-like dependence of the heat capacity on the
temperature, which for the infinite number of bosons transforms into the
discontinuity of $c_N(T)$, is an indication of the phase transition to the
condensate state. Qualitative and quantitative explanation of these physical
phenomena is based on the variation of the energy spectrum by the electric
field.

categories: quant-ph cond-mat.mes-hall math-ph math.MP


title:
Theory of the Robin quantum wall in a linear potential. I. Energy
  spectrum, polarization and quantum-information measures

abstract:
  Information-theoretical concepts are employed for the analysis of the
interplay between a transverse electric field $\mathscr{E}$ applied to a
one-dimensional surface and Robin boundary condition (BC), which with the help
of the extrapolation length $\Lambda$ zeroes at the interface a linear
combination of the quantum mechanical wave function and its spatial derivative,
and its influence on the properties of the structure. For doing this, exact
analytical solutions of the corresponding Schr\"{o}dinger equation are derived
and used for calculating energies, dipole moments, position $S_x$ and momentum
$S_k$ quantum information entropies and their Fisher information $I_x$ and
$I_k$ and Onicescu information energies $O_x$ and $O_k$ counterparts. It is
shown that the weak (strong) electric field changes the Robin wall into the
Dirichlet, $\Lambda=0$ (Neumann, $\Lambda=\infty$), surface. This
transformation of the energy spectrum and associated waveforms in the growing
field defines an evolution of the quantum-information measures; for example, it
is proved that for the Dirichlet and Neumann BCs the position (momentum)
quantum information entropy varies as a positive (negative) natural logarithm
of the electric intensity what results in their field-independent sum
$S_x+S_k$. Analogously, at $\Lambda=0$ and $\Lambda=\infty$ the position and
momentum Fisher informations (Onicescu energies) depend on the applied voltage
as $\mathscr{E}^{2/3}$ ($\mathscr{E}^{1/3}$) and its inverse, respectively,
leading to the field-independent product $I_xI_k$ ($O_xO_k$). Peculiarities of
their transformations at the finite nonzero $\Lambda$ are discussed and
similarities and differences between the three quantum-information measures in
the electric field are highlighted with the special attention being paid to the
configuration with the negative extrapolation length.


title: Minimax rational approximation of the Fermi-Dirac distribution

abstract:
  Accurate rational approximations of the Fermi-Dirac distribution are a useful
component in many numerical algorithms for electronic structure calculations.
The best known approximations use $O( \log (\beta \Delta) \log
(\epsilon^{-1}))$ poles to achieve an error tolerance $\epsilon$ at temperature
$\beta^{-1}$ over an energy interval $\Delta$. We apply minimax approximation
to reduce the number of poles by a factor of four and replace $\Delta$ with
$\Delta_{\mathrm{occ}}$, the occupied energy interval. This is particularly
beneficial when $\Delta \gg \Delta_{\mathrm{occ}}$, such as in electronic
structure calculations that use a large basis set.


title: Shotgun Assembly of Random Jigsaw Puzzles

abstract:
  In a recent work, Mossel and Ross considered the shotgun assembly problem for
a random jigsaw puzzle. Their model consists of a puzzle - an $n\times n$ grid,
where each vertex is viewed as a center of a piece. They assume that each of
the four edges adjacent to a vertex, is assigned one of $q$ colors
(corresponding to "jigs", or cut shapes) uniformly at random. Mossel and Ross
asked: how large should $q = q(n)$ be so that with high probability the puzzle
can be assembled uniquely given the collection of individual tiles? They showed
that if $q = \omega(n^2)$, then the puzzle can be assembled uniquely with high
probability, while if $q = o(n^{2/3})$, then with high probability the puzzle
cannot be uniquely assembled. Here we improve the upper bound and show that for
any $\eps > 0$, the puzzle can be assembled uniquely with high probability if
$q \geq n^{1+\eps}$. The proof uses an algorithm of $n^{\Theta(1/\eps)}$
running time.


title: Regarding the Radion in Randall-Sundrum Models with Brane Curvature

abstract:
  In Randall-Sundrum models, one typically expects the radion to be the
lightest new "gravity" state, as it is dual to a composite pseudo-Goldstone
boson associated with conformal symmetry breaking in the IR. Here, we
investigate the effects of localized brane curvature on the properties of the
radion in Goldberger-Wise stabilized Randall-Sundrum models. We point out that
both the radion mass and coupling to brane matter are sensitive to the brane
curvature. Radion/Higgs kinetic mixing, via an IR-localized non-minimal
coupling to the Higgs, is also investigated, in relation to the ghost-like
radion that can occur for $\mathcal{O}(10)$ values of the IR curvature (as
required to significantly suppress the first Kaluza-Klein graviton mass). We
also discuss a class of speculative IR localized terms involving the radion.
Basic comments regarding the dual 4D theory are offered.


title:
Analysis of beta-decay data acquired at the Physikalisch-Technische
  Bundesanstalt: evidence of a solar influence

abstract:
  According to an article entitled Disproof of solar influence on the decay
rates of 90Sr/90Y by Kossert and N\"ahle of the Physikalisch-Technische
Bundesanstalt (PTB) [1], the PTB measurements show no evidence of variability.
We show that, on the contrary, those measurements reveal strong evidence of
variability, including an oscillation at 11 year-1 that is suggestive of an
influence of internal solar rotation. An analysis of radon beta-decay data
acquired at the Geological Survey of Israel (GSI) Laboratory for the same time
interval yields strong confirmation of this oscillation.


title: Hydride Vapor Phase Epitaxy of GaN on Silicon Covered by Nanostructures

abstract:
  Several ten $\mu$m GaN have been deposited on a silicon substrate using a
two-step hydride vapor phase epitaxy (HVPE) process. The substrates have been
covered by AlN layers and GaN nanostructures grown by plasma-assisted
molecular-beam epitaxy. During the first low-temperature (low-T) HVPE step,
stacking faults (SF) form, which show distinct luminescence lines and
stripe-like features in cathodoluminescence images of the cross-section of the
layers. These cathodoluminescence features allow for an insight into the growth
process. During a second high-temperature (high-T) step, the SFs disappear, and
the luminescence of this part of the GaN layer is dominated by the donor-bound
exciton. For templates consisting of both a thin AlN buffer and GaN
nanostructures, a silicon incorporation into the GaN grown by HVPE is not
observed. Moreover, the growth mode of the (high-T) HVPE step depends on the
specific structure of the AlN/GaN template, where in a first case, the epitaxy
is dominated by the formation of slowly growing facets, while in a second case,
the epitaxy proceeds directly along the c-axis.


title:
Metabolite transport through glial networks stabilizes the dynamics of
  learning

abstract:
  Learning and memory are acquired through long-lasting changes in synapses. In
the simplest models, such synaptic potentiation typically leads to runaway
excitation, but in reality there must exist processes that robustly preserve
overall stability of the neural system dynamics. How is this accomplished?
Various approaches to this basic question have been considered. Here we propose
a particularly compelling and natural mechanism for preserving stability of
learning neural systems. This mechanism is based on the global processes by
which metabolic resources are distributed to the neurons by glial cells.
Specifically, we introduce and study a model comprised of two interacting
networks: a model neural network interconnected by synapses which undergo
spike-timing dependent plasticity (STDP); and a model glial network
interconnected by gap junctions which diffusively transport metabolic resources
among the glia and, ultimately, to neural synapses where they are consumed. Our
main result is that the biophysical constraints imposed by diffusive transport
of metabolic resources through the glial network can prevent runaway growth of
synaptic strength, both during ongoing activity and during learning. Our
findings suggest a previously unappreciated role for glial transport of
metabolites in the feedback control stabilization of neural network dynamics
during learning.


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

abstract:
  We present an updated EDM effective electric field of $E_{\text{eff}} =
75.2\left[\frac{\rm GV}{\rm cm}\right]$ and the electron-nucleon
scalar-pseudoscalar interaction constant $W_S=107.8$ [kHz] for the
${^3\Delta}_1$ science state of ThO. The criticisms made in reference [J. Chem.
Phys. 142, 024301 (2015)] are addressed and largely found to be unsubstantiated
within the framework of our approach.


title: Large-scale instabilities of helical flows

abstract:
  Large-scale hydrodynamic instabilities of periodic helical flows are
investigated using $3$D Floquet numerical computations. A minimal three-modes
analytical model that reproduce and explains some of the full Floquet results
is derived. The growth-rate $\sigma$ of the most unstable modes (at small
scale, low Reynolds number $Re$ and small wavenumber $q$) is found to scale
differently in the presence or absence of anisotropic kinetic alpha (\AKA{})
effect. When an $AKA$ effect is present the scaling $\sigma \propto q\; Re\,$
predicted by the $AKA$ effect theory [U. Frisch, Z. S. She, and P. L. Sulem,
Physica D: Nonlinear Phenomena 28, 382 (1987)] is recovered for $Re\ll 1$ as
expected (with most of the energy of the unstable mode concentrated in the
large scales). However, as $Re$ increases, the growth-rate is found to saturate
and most of the energy is found at small scales. In the absence of \AKA{}
effect, it is found that flows can still have large-scale instabilities, but
with a negative eddy-viscosity scaling $\sigma \propto \nu(b Re^2-1) q^2$. The
instability appears only above a critical value of the Reynolds number
$Re^{c}$. For values of $Re$ above a second critical value $Re^{c}_{S}$ beyond
which small-scale instabilities are present, the growth-rate becomes
independent of $q$ and the energy of the perturbation at large scales decreases
with scale separation. A simple two-modes model is derived that well describes
the behaviors of energy concentration and growth-rates of various unstable
flows. In the non-linear regime (at moderate values of $Re$) and in the
presence of scale separation, the forcing scale and the largest scales of the
system are found to be the most dominant energetically.


title: Projector operators in clustering

abstract:
  In a recent paper the notion of {\em quantum perceptron} has been introduced
in connection with projection operators. Here we extend this idea, using these
kind of operators to produce a {\em clustering machine}, i.e. a framework which
generates different clusters from a set of input data. Also, we consider what
happens when the orthonormal bases first used in the definition of the
projectors are replaced by frames, and how these can be useful when trying to
connect some noised signal to a given cluster.