title: Hurwitz spaces and liftings to the Valentiner group

abstract:
  We study the components of the Hurwitz scheme of ramified coverings of
$\mathbb{P}^1$ with monodromy given by the alternating group $A_6$ and elements
in the conjugacy class of product of two disjoint cycles. In order to detect
the connected components of the Hurwitz scheme, inspired by the case of the
spin structures studied by Fried for the $3$-cycles, we use as invariant the
lifting to the Valentiner group, triple covering of $A_6$. We prove that the
Hurwitz scheme has two irreducible components when the genus of the covering is
greater than zero, in accordance with the asymptotic solution found by
Bogomolov and Kulikov.


title: Quantifying some properties of the stochastic quantum force

abstract:
  We consider for clarity the simple case of the one dimensional
non-relativistic Schr\"{o}dinger equation and regard it as an ensemble mean
representation of the stochastic motion of a single particle in a vacuum,
subject to an undefined stochastic quantum force. By analyzing the Bohm
potential it is found that the imaginary part of the quantum momentum is the
root mean square fluctuation of the particle around its mean velocity, where
the latter is the real part of the quantum momentum. The local mean of the
quantum force is found to be proportional to the third spatial derivative of
the probability density function, and its associated pressure to the second
spatial derivative. The latter is decomposed from the single particle diluted
gas pressure, and this pressure partition allows the interpretation of the
quantum Bohm potential as the energy required to put a particle in a bath of
fluctuating vacuum at constant entropy and volume.
  The stochastic force expectation value is zero and is uncorrelated with the
particle location, thus does not perform work on average. Nonetheless it is
anti-correlated with volume and this anti-correlation leads to a new type of an
Heisenberg like relation. We imply the dynamic Gaussian solution to the
Schr\"{o}dinger equation as a simple example for exploring the mean properties
of this quantum force. Still an interesting remained open task is the
identification of the stochastic law that leads to these obtained mean
properties.


title:
Model reduction of linear time-varying systems with applications for
  moving loads

abstract:
  In this paper we consider different model reduction techniques for systems
with moving loads. Due to the time-dependency of the input and output matrices,
the application of time-varying projection matrices for the reduction offers
new degrees of freedom, which also come along with some challenges. This paper
deals with both simple methods for the reduction of particular linear
time-varying systems, as well as with a more advanced technique considering the
emerging time derivatives.


title:
Cartan subalgebras of tensor products of free quantum group factors with
  arbitrary factors

abstract:
  Let $\mathbb{G}$ be a free (unitary or orthogonal) quantum group. We prove
that for any non-amenable subfactor $N\subset L^\infty(\mathbb{G})$, which is
an image of a faithful normal conditional expectation, and for any
$\sigma$-finite factor $B$, the tensor product $N \otimes B$ has no Cartan
subalgebras. This generalizes our previous work that provides the same result
when $B$ is finite. In the proof, we establish Ozawa--Popa and Popa--Vaes's
weakly compact action on the continuous core of $N \otimes B$ as the one
relative to B, by using an operator valued weight to B and the central weak
amenability of $\mathbb{G}$.


title:
Remarks on endpoint Strichartz estimates for Schr\"odinger equations
  with the critical inverse-square potential

abstract:
  The purpose of this paper is to study the validity of global-in-time
Strichartz estimates for the Schr\"odinger equation on $\mathbb{R}^n$, $n\ge3$,
with the negative inverse-square potential $-\sigma|x|^{-2}$ in the critical
case $\sigma=(n-2)^2/4$. It turns out that the situation is different from the
subcritical case $\sigma<(n-2)^2/4$ in which the full range of Strichartz
estimates is known to be hold. More precisely, splitting the solution into the
radial and non-radial parts, we show that (i) the radial part satisfies a
weak-type endpoint estimate, which can be regarded as an extension to higher
dimensions of the endpoint Strichartz estimate with radial data for the
two-dimensional free Schr\"odinger equation; (ii) other endpoint estimates in
Lorentz spaces for the radial part fail in general; (iii) the non-radial part
satisfies the full range of Strichartz estimates.


title: Affine embeddings of Cantor sets on the line

abstract:
  Let $s\in (0,1)$, and let $F\subset \mathbb{R}$ be a self similar set such
that $0 < \dim_H F \leq s$ . We prove that there exists $\delta= \delta(s) >0$
such that if $F$ admits an affine embedding into a homogeneous self similar set
$E$ and $0 \leq \dim_H E - \dim_H F < \delta$ then (under some mild conditions
on $E$ and $F$) the contraction ratios of $E$ and $F$ are logarithmically
commensurable. This provides more evidence for a Conjecture of Feng, Huang, and
Rao, that states that these contraction ratios are logarithmically
commensurable whenever $F$ admits an affine embedding into $E$ (under some mild
conditions). Our method is a combination of an argument based on the approach
of Feng, Huang, and Rao, with a new result by Hochman, which is related to the
increase of entropy of measures under convolutions.


title: Josephson Quantum Heat Engine

abstract:
  The design of a mesoscopic self-oscillating heat engine that works thanks to
purely quantum effects is presented. The proposed scheme is amenable to
experimental implementation with current state-of-the-art nanotechnology and
materials. One of the main features of the structure is its versatility: The
engine can deliver work to a generic load without galvanic contact. This makes
it a promising building block for low-temperature on-chip energy management
applications. The heat engine consists of a circuit featuring a thermoelectric
element based on a ferromagnetic insulator-superconductor tunnel junction and a
Josephson weak link that realizes a purely quantum DC/AC converter. This
enables contactless transfer of work to the load (a generic RL circuit). The
performance of the heat engine is investigated as a function of the thermal
gradient applied to the thermoelectric junction. Power up to $1$ pW can be
delivered to a load $R_L=10\ \Omega$.

categories: cond-mat.mes-hall cond-mat.stat-mech cond-mat.supr-con quant-ph


title: Microscopic theory of electron absorption by plasma-facing surfaces

abstract:
  We describe a method for calculating the probability with which the wall of a
plasma absorbs an electron at low energy. The method, based on an invariant
embedding principle, expresses the electron absorption probability as the
probability for transmission through the wall's long-range surface potential
times the probability to stay inside the wall despite of internal
backscattering. To illustrate the approach we apply it to a \SiOTwo\ surface.
Besides emission of optical phonons inside the wall we take elastic scattering
at imperfections of the plasma-wall interface into account and obtain
absorption probabilities significantly less than unity in accordance with
available electron-beam scattering data but in disagreement with the widely
used perfect absorber model.


title:
Exact Casimir interaction of perfectly conducting three-spheres in four
  euclidean dimensions

abstract:
  Exploiting conformal symmetry, we derive a simple exact formula for the
classical electromagnetic Casimir interaction of two perfectly conducting
three-spheres, including the sphere-plate geometry as a special case, in four
euclidean dimensions. We verify that the short distance expansion of the
Casimir energy agrees to leading order with the Proximity Force Approximation
(PFA), while the next-to-leading-order is in agreement with a recently proposed
derivative expansion of the Casimir energy. At the next-to-next-to-leading
order we find a non-analytic correction to PFA, which for a sphere-plate system
is of the order of $(d/R)^{3/2} \log(d/R)$, where $d$ is the separation and $R$
the sphere radius.


title: Orbital-dependent charge dynamics in MnP revealed by optical study

abstract:
  Unconventional superconductivity often emerges at the border of long-range
magnetic orders. Understanding the low-energy charge dynamics may provide
crucial information on the formation of superconductivity. Here we report the
unpolarized/polarized optical conductivity study of high quality MnP single
crystals at ambient pressure. Our data reveal two types of charge carriers with
very different lifetimes. In combination with the first-principles
calculations, we show that the short-lifetime carriers have flat Fermi sheets
which become gapped in the helimagnetic phase, causing a dramatic change in the
low-frequency optical spectra, while the long-lifetime carriers are anisotropic
three-dimensional like which are little affected by the magnetic transitions
and provide major contributions to the transport properties. This
orbital-dependent charge dynamics originates from the special crystal structure
of MnP and may have an influence on the unconventional superconductivity and
its interplay with helimagnetism at high pressures.


title:
Spin- and angle-resolved photoemission on the topological Kondo
  Insulator candidate: SmB6

abstract:
  Topological Kondo insulators are a new class of topological insulators in
which metallic surface states protected by topological invariants reside in the
bulk band gap at low temperatures. Unlike other three-dimensional topological
insulators, a truly insulating bulk state, which is critical for potential
applications in next-generation electronic devices, is guaranteed by many-body
effects in the topological Kondo insulator. Furthermore, the system has strong
electron correlations that can serve as a testbed for interacting topological
theories. This topical review focuses on recent advances in the study of SmB6,
the most promising candidate for a topological Kondo insulator, from the
perspective of spin- and angle-resolved photoemission spectroscopy with
highlights of some important transport results.


title: Equidistribution of zeros of random polynomials

abstract:
  We study the asymptotic distribution of zeros for the random polynomials
$P_n(z) = \sum_{k=0}^n A_k B_k(z)$, where $\{A_k\}_{k=0}^{\infty}$ are
non-trivial i.i.d. complex random variables. Polynomials
$\{B_k\}_{k=0}^{\infty}$ are deterministic, and are selected from a standard
basis such as Szeg\H{o}, Bergman, or Faber polynomials associated with a Jordan
domain $G$ bounded by an analytic curve. We show that the zero counting
measures of $P_n$ converge almost surely to the equilibrium measure on the
boundary of $G$ if and only if $\mathbb{E}[\log^+|A_0|]<\infty$.


title: Effect of local environment on moment formation in iron silicides

abstract:
  The effect of local environment on the formation of magnetic moments on Fe
atoms in iron silicides are studied by combination of ab initio and model
calculations. The suggested model includes all Fe d- and Si p-orbitals,
intra-atomic Coulomb interactions, inter-atomic Fe-Fe exchange and hopping of
electrons to nearest and next nearest neighboring atoms and takes into account
all symmetries within the Slater-Koster scheme. The parameters of the model are
found from the requirement that self-consistent moments on atoms and density of
states found from ab initio and model calculations within the Hartree-Fock
approximation are close to each other as much as possible. Contrary to the
commonly accepted statement that an increase of the Si concentration within
nearest environment of Fe atoms in the ordered Fe3Si and FexSi1-x alloys leads
to a decrease of Fe magnetic moment we find that a crucial role in the
formation of magnetic moments is played by second coordination sphere of Fe
atoms. Particularly, the Fe atoms have higher magnetic moments in amorphous
films compared to the epitaxial ones due to decrease in the number of
iron-atoms in the next nearest environment. Both our model and ab initio
calculations confirm existence of known spin crossover with pressure and
predict second crossover at higher pressure


title:
Classifying Variable-Length Audio Files with All-Convolutional Networks
  and Masked Global Pooling

abstract:
  We trained a deep all-convolutional neural network with masked global pooling
to perform single-label classification for acoustic scene classification and
multi-label classification for domestic audio tagging in the DCASE-2016
contest. Our network achieved an average accuracy of 84.5% on the four-fold
cross-validation for acoustic scene recognition, compared to the provided
baseline of 72.5%, and an average equal error rate of 0.17 for domestic audio
tagging, compared to the baseline of 0.21. The network therefore improves the
baselines by a relative amount of 17% and 19%, respectively. The network only
consists of convolutional layers to extract features from the short-time
Fourier transform and one global pooling layer to combine those features. It
particularly possesses neither fully-connected layers, besides the
fully-connected output layer, nor dropout layers.


title:
Incremental Factorization Machines for Persistently Cold-starting Online
  Item Recommendation

abstract:
  Real-world item recommenders commonly suffer from a persistent cold-start
problem which is caused by dynamically changing users and items. In order to
overcome the problem, several context-aware recommendation techniques have been
recently proposed. In terms of both feasibility and performance, factorization
machine (FM) is one of the most promising methods as generalization of the
conventional matrix factorization techniques. However, since online algorithms
are suitable for dynamic data, the static FMs are still inadequate. Thus, this
paper proposes incremental FMs (iFMs), a general online factorization
framework, and specially extends iFMs into an online item recommender. The
proposed framework can be a promising baseline for further development of the
production recommender systems. Evaluation is done empirically both on
synthetic and real-world unstable datasets.


title: Cubic scaling $GW$: towards fast quasiparticle calculations

abstract:
  Within the framework of the full potential projector-augmented wave
methodology, we present a promising low-scaling $GW$ implementation. It allows
for quasiparticle calculations with a scaling that is cubic in the system size
and linear in the number of $k$ points used to sample the Brillouin zone. This
is achieved by calculating the polarizability and self-energy in the real space
and imaginary time domain. The transformation from the imaginary time to the
frequency domain is done by an efficient discrete Fourier transformation with
only a few nonuniform grid points. Fast Fourier transformations are used to go
from real space to reciprocal space and vice versa. The analytic continuation
from the imaginary to the real frequency axis is performed by exploiting
Thiele's reciprocal difference approach. Finally, the method is applied
successfully to predict the quasiparticle energies and spectral functions of
typical semiconductors (Si, GaAs, SiC, and ZnO), insulators (C, BN, MgO, and
LiF), and metals (Cu and SrVO$_3$). The results are compared with conventional
$GW$ calculations. Good agreement is achieved, highlighting the strength of the
present method.


title: A simple laser locking system based on a field-programmable gate array

abstract:
  Frequency stabilization of laser light is crucial in both scientific and
industrial applications. Technological developments now allow analog laser
stabilization systems to be replaced with digital electronics such as
field-programmable gate arrays, which have recently been utilized to develop
such locking systems. We have developed a frequency stabilization system based
on a field-programmable gate array, with emphasis on hardware simplicity, which
offers a user-friendly alternative to commercial and previous home-built
solutions. Frequency modulation, lock-in detection and a
proportional-integral-derivative controller are programmed on the
field-programmable gate array and only minimal additional components are
required to frequency stabilize a laser. The locking system is administered
from a host-computer which provides comprehensive, long-distance control
through a versatile interface. Various measurements were performed to
characterize the system. The linewidth of the locked laser was measured to be
$0.7 \pm 0.1 \; \rm{MHz}$ with a settling time of $10 \; \rm{ms}$. The system
can thus fully match laser systems currently in use for atom trapping and
cooling applications.


title:
A two-sided academic landscape: portrait of highly-cited documents in
  Google Scholar (1950-2013)

abstract:
  The main objective of this paper is to identify the set of highly-cited
documents in Google Scholar and to define their core characteristics (document
types, language, free availability, source providers, and number of versions),
under the hypothesis that the wide coverage of this search engine may provide a
different portrait about this document set respect to that offered by the
traditional bibliographic databases. To do this, a query per year was carried
out from 1950 to 2013 identifying the top 1,000 documents retrieved from Google
Scholar and obtaining a final sample of 64,000 documents, of which 40% provided
a free full-text link. The results obtained show that the average highly-cited
document is a journal article or a book (62% of the top 1% most cited documents
of the sample), written in English (92.5% of all documents) and available
online in PDF format (86.0% of all documents). Yet, the existence of errors
especially when detecting duplicates and linking cites properly must be pointed
out. The fact of managing with highly cited papers, however, minimizes the
effects of these limitations. Given the high presence of books, and to a lesser
extend of other document types (such as proceedings or reports), the research
concludes that Google Scholar data offer an original and different vision of
the most influential academic documents (measured from the perspective of their
citation count), a set composed not only by strictly scientific material
(journal articles) but academic in its broad sense


title: A bifurcation analysis for the Lugiato-Lefever equation

abstract:
  The Lugiato-Lefever equation is a cubic nonlinear Schr\"odinger equation,
including damping, detuning and driving, which arises as a model in nonlinear
optics. We study the existence of stationary waves which are found as solutions
of a four-dimensional reversible dynamical system in which the evolutionary
variable is the space variable. Relying upon tools from bifurcation theory and
normal forms theory, we discuss the codimension 1 bifurcations. We prove the
existence of various types of steady solutions, including spatially localized,
periodic, or quasi-periodic solutions.


title: The denominators of harmonic numbers

abstract:
  The denominators $d_n$ of the harmonic number
$1+\frac12+\frac13+\cdots+\frac1n$ do not increase monotonically with~$n$. It
is conjectured that $d_n=D_n={\rm LCM}(1,2,\ldots,n)$ infinitely often. For an
odd prime $p$, the set $\{n:pd_n|D_n\}$ has a harmonic density and, for
$2<p_1<p_2<\cdots<p_k$, there exists $n$ such that $p_1p_2\cdots p_kd_n|D_n$.


title:
On the Structure of Equilibrium Strategies in Dynamic Gaussian Signaling
  Games

abstract:
  This paper analyzes a finite horizon dynamic signaling game motivated by the
well-known strategic information transmission problems in economics. The
mathematical model involves information transmission between two agents, a
sender who observes two Gaussian processes, state and bias, and a receiver who
takes an action based on the received message from the sender. The players
incur quadratic instantaneous costs as functions of the state, bias and action
variables. Our particular focus is on the Stackelberg equilibrium, which
corresponds to information disclosure and Bayesian persuasion problems in
economics. Prior work solved the static game, and showed that the Stackelberg
equilibrium is achieved by pure strategies that are linear functions of the
state and the bias variables. The main focus of this work is on the dynamic
(multi-stage) setting, where we show that the existence of a pure strategy
Stackelberg equilibrium, within the set of linear strategies, depends on the
problem parameters. Surprisingly, for most problem parameters, a pure linear
strategy does not achieve the Stackelberg equilibrium which implies the
existence of a trade-off between exploiting and revealing information, which
was also encountered in several other asymmetric information games.


title:
Significance of Natural Scene Statistics in Understanding the
  Anisotropies of Perceptual Filling-in at the Blind Spot

abstract:
  Psychophysical experiments reveal our horizontal preference in perceptual
filling-in at the blind spot. On the other hand, vertical preference is
exhibited in the case of tolerance in filling-in. What causes this anisotropy
in our perception? Building upon the general notion, that the functional
properties of the early visual system are shaped by the innate specification as
well as the statistics of the environment, we reasoned that the anisotropy in
filling-in could be understood in terms of anisotropy in orientation
distribution inherent to natural scene statistics. We examined this proposition
by investigating filling-in of bar stimuli on a Hierarchical Predictive Coding
model network. In response to bar stimuli, the model network, trained with
natural images, exhibited anisotropic filling-in performance at the blind spot
similar to reported in psychophysical experiments i.e. horizontal preference in
filling-in and vertical preference in tolerance of filling-in. We suggest that
the over-representation of horizontal contours in the natural scene contribute
to the observed horizontal superiority while the broader distribution of
vertical contours contributes to the observed vertical superiority in
tolerance. These results indicate that natural scene statistics plays a
significant role in determining the filling-in performance at the blind spot
and shaping the associated anisotropies.


title:
A quasi-periodic modulation of the iron line centroid energy in the
  black hole binary H 1743-322

abstract:
  Accreting stellar-mass black holes often show a `Type-C' quasi-periodic
oscillation (QPO) in their X-ray flux, and an iron emission line in their X-ray
spectrum. The iron line is generated through continuum photons reflecting off
the accretion disk, and its shape is distorted by relativistic motion of the
orbiting plasma and the gravitational pull of the black hole. The physical
origin of the QPO has long been debated, but is often attributed to
Lense-Thirring precession, a General Relativistic effect causing the inner flow
to precess as the spinning black hole twists up the surrounding space-time.
This predicts a characteristic rocking of the iron line between red and blue
shift as the receding and approaching sides of the disk are respectively
illuminated. Here we report on XMM-Newton and NuSTAR observations of the black
hole binary H 1743-322 in which the line energy varies systematically over the
~4 s QPO cycle (3.70 sigma significance), as predicted. This provides strong
evidence that the QPO is produced by Lense-Thirring precession, constituting
the first detection of this effect in the strong gravitation regime. There are
however elements of our results harder to explain, with one section of data
behaving differently to all the others. Our result enables the future
application of tomographic techniques to map the inner regions of black hole
accretion disks.


title:
Initial Experiments on Learning-Based Randomized Bin-Picking Allowing
  Finger Contact with Neighboring Objects

abstract:
  This paper proposes a novel method for randomized bin-picking based on
learning. When a two-fingered gripper tries to pick an object from the pile, a
finger often contacts a neighboring object. Even if a finger contacts a
neighboring object, the target object will be successfully picked depending on
the configuration of neighboring objects. In our proposed method, we use the
visual information on neighboring objects to train the discriminator.
Corresponding to a grasping posture of an object, the discriminator predicts
whether or not the pick will be successful even if a finger contacts a
neighboring object. We examine two learning algorithms, the linear support
vector machine (SVM) and the random forest (RF) approaches. By using both
methods, we demonstrate that the picking success rate is significantly higher
than with conventional methods without learning.


title:
Proceedings of the CAS - CERN Accelerator School: Power Converters,
  Baden, Switzerland, 7-14 May 2014

abstract:
  These proceedings collate lectures given at the twenty-eighth specialized
course organised by the CERN Accelerator School (CAS). The course was held at
the Hotel du Parc, Baden, Switzerland from 7 - 14 May 2014, in collaboration
with the Paul Scherrer Institute. Following introductory lectures on
accelerators and the requirements on power converters, the course covered
components and topologies of the different types of power converters needed for
particle accelerators. Issues of design, control and exploitation in a
sometimes-hostile environment were addressed. Site visits to ABB and PSI
provided an insight into state-of-the-art power converter production and
operation, while topical seminars completed the programme.


title:
Some Features of Scattering Problem in a $\kappa$-Deformed Minkowski
  Spacetime

abstract:
  The doubly special relativity (DSR) theories are suggested in order to
incorporate an observer-independent length scale in special theory of
relativity. The Magueijo-Smolin proposal of DSR is realizable through a
particular form of the noncommutative (NC) spacetime (known as
$\kappa$-Minkowski spacetime) in which the Lorentz symmetry is preserved. In
this framework, the NC parameter $\kappa$ provides the origin of natural cutoff
energy scale. Using a nonlinear deformed relativistic dispersion relation along
with the Lorentz transformations, we investigate some phenomenological facets
of two-body collision problem (without creation of new particles) in a
$\kappa$-Minkowski spacetime. By treating an elastic scattering problem, we
study effects of the Planck scale energy cutoff on some relativistic
kinematical properties of this scattering problem. The results are challenging
in the sense that as soon as one turns on the $\kappa$-spacetime extension, the
nature of the two-body collision alters from elastic to inelastic one. It is
shown also that a significant kinematical variable involving in heavy ion
collisions, the rapidity, is not essentially an additive quantity under a
sequence of the nonlinear representation of the Lorentz transformations.


title:
Geomagnetically trapped, albedo and solar energetic particles:
  trajectory analysis and flux reconstruction with PAMELA

abstract:
  The PAMELA satellite experiment is providing comprehensive observations of
the interplanetary and magnetospheric radiation in the near-Earth environment.
Thanks to its identification capabilities and the semi-polar orbit, PAMELA is
able to precisely measure the energetic spectra and the angular distributions
of the different cosmic-ray populations over a wide latitude region, including
geomagnetically trapped and albedo particles. Its observations comprise the
solar energetic particle events between solar cycles 23 and 24, and the
geomagnetic cutoff variations during magnetospheric storms. PAMELA's
measurements are supported by an accurate analysis of particle trajectories in
the Earth's magnetosphere based on a realistic geomagnetic field modeling,
which allows the classification of particle populations of different origin and
the investigation of the asymptotic directions of arrival.


title: Dirac Delta Function of Matrix Argument

abstract:
  Dirac delta function of matrix argument is employed frequently in the
development of diverse fields such as Random Matrix Theory, Quantum Information
Theory, etc. The purpose of the article is pedagogical, it begins by recalling
detailed knowledge about Heaviside unit step function and Dirac delta function.
Then its extensions of Dirac delta function to vector spaces and matrix spaces
are discussed systematically, respectively. The detailed and elementary proofs
of these results are provided. Though we have not seen these results formulated
in the literature, there certainly are predecessors. Applications are also
mentioned.


title: Two rate periodic protocol with dynamics driven through many cycles

abstract:
  We study the long time dynamics in closed quantum systems periodically driven
via time dependent parameters with two frequencies $\omega_1$ and $\omega_2=r
\omega_1$. Tuning of the ratio $r$ there can unleash plenty of dynamical
phenomena to occur. Our study includes integrable models like Ising and XY
models in $d=1$ and Kitaev model in $d=1$ and $2$ and can also be extended to
Dirac fermions in graphene. We witness the wave-function overlap or dynamic
freezing to occur within some small/ intermediate frequency regimes in the
$(\omega_1 ,r)$ plane (with $r\ne0$) when the ground state is evolved through
single cycle of driving. However, evolved states soon become steady with long
driving and the freezing scenario gets rarer. We extend the formalism of
adiabatic-impulse approximation for many cycle driving within our two-rate
protocol and show the near-exact comparisons at small frequencies. An extension
of the rotating wave approximation is also developed to gather an analytical
framework of the dynamics at high frequencies. Finally we compute the
entanglement entropy in the stroboscopically evolved states within the gapped
phases of the system and observe how it gets tuned with the ratio $r$ in our
protocol. The minimally entangled states are found to fall within the regime of
dynamical freezing. In general, the results indicate that the entanglement
entropy in our driven short-ranged integrable systems follow genuine non-area
law of scaling and show a convergence (with a $r$ dependent pace) towards
volume scaling behavior as the driving is continued for long time.


title: Deformations of Legendrian Curves

abstract:
  We construct versal and equimultiple versal deformations of the
parametrization of a Legendrian curve.


title: Mapping Reactive Flow Patterns in Monolithic Nanoporous Catalysts

abstract:
  The development of high-efficiency porous catalyst membranes critically
depends on our understanding of where the majority of the chemical conversions
occur within the porous structure. This requires mapping of chemical reactions
and mass transport inside the complex nano-scale architecture of porous
catalyst membranes which is a multiscale problem in both the temporal and
spatial domain. To address this problem, we developed a multi-scale mass
transport computational framework based on the Lattice Boltzmann Method (LBM)
that allows us to account for catalytic reactions at the gas-solid interface by
introducing a new boundary condition. In good agreement with experiments, the
simulations reveal that most catalytic reactions occur near the gas-flow facing
side of the catalyst membrane if chemical reactions are fast compared to mass
transport within the porous catalyst membrane.

categories: physics.flu-dyn cond-mat.mtrl-sci physics.chem-ph physics.comp-ph


title: Radio-Optical Galaxy Shape Correlations in the COSMOS Field

abstract:
  We investigate the correlations in galaxy shapes between optical and radio
wavelengths using archival observations of the COSMOS field. Cross-correlation
studies between different wavebands will become increasingly important for
precision cosmology as future large surveys may be dominated by systematic
rather than statistical errors. In the case of weak lensing, galaxy shapes must
be measured to extraordinary accuracy (shear systematics of $< 0.01\%$) in
order to achieve good constraints on dark energy parameters. By using shape
information from overlapping surveys in optical and radio bands, robustness to
systematics may be significantly improved without loss of constraining power.
Here we use HST-ACS optical data, VLA radio data, and extensive simulations to
investigate both our ability to make precision measurements of source shapes
from realistic radio data, and to constrain the intrinsic astrophysical scatter
between the shapes of galaxies as measured in the optical and radio wavebands.
By producing a new image from the VLA-COSMOS L-band radio visibility data that
is well suited to galaxy shape measurements, we are able to extract precise
measurements of galaxy position angles. Comparing to corresponding measurements
from the HST optical image, we set a lower limit on the intrinsic astrophysical
scatter in position angles, between the optical and radio bands, of
$\sigma_\alpha > 0.212\pi$ radians (or $38.2^{\circ}$) at a $95\%$ confidence
level.


title: Studying the evolution of AGB stars in the Gaia epoch

abstract:
  We present asymptotic giant branch (AGB) models of solar metallicity, to
allow the interpretation of observations of Galactic AGB stars, whose distances
should be soon available after the first release of the Gaia catalogue. We find
an abrupt change in the AGB physical and chemical properties, occurring at the
threshold mass to ignite hot bottom burning,i.e. $3.5M_{\odot}$. Stars with
mass below $3.5 M_{\odot}$ reach the C-star stage and eject into the
interstellar medium gas enriched in carbon , nitrogen and $^{17}O$. The higher
mass counterparts evolve at large luminosities, between $3\times 10^4
L_{\odot}$ and $10^5 L_{\odot}$. The mass expelled from the massive AGB stars
shows the imprinting of proton-capture nucleosynthesis, with considerable
production of nitrogen and sodium and destruction of $^{12}C$ and $^{18}O$. The
comparison with the most recent results from other research groups are
discussed, to evaluate the robustness of the present findings. Finally, we
compare the models with recent observations of galactic AGB stars, outlining
the possibility offered by Gaia to shed new light on the evolution properties
of this class of objects.


title:
Dynamical symmetry enhancement near N=2, D=4 gauged supergravity
  horizons

abstract:
  We show that all smooth Killing horizons with compact horizon sections of
4-dimensional gauged N=2 supergravity coupled to any number of vector
multiplets preserve $2 c_1({\cal K})+4 \ell$ supersymmetries, where ${\cal K}$
is a pull-back of the Hodge bundle of the special K\"ahler manifold on the
horizon spatial section. We also demonstrate that all such horizons with
$c_1({\cal K})=0$ exhibit an SL(2,R) symmetry and preserve either 4 or 8
supersymmetries. If the orbits of the SL(2,R) symmetry are 2-dimensional, the
horizons are warped products of AdS2 with the horizon spatial section.
Otherwise, the horizon section admits an isometry which preserves all the
fields. The proof of these results is centered on the use of index theorem in
conjunction with an appropriate generalization of the Lichnerowicz theorem for
horizons that preserve at least one supersymmetry. In all $c_1({\cal K})=0$
cases, we specify the local geometry of spatial horizon sections and
demonstrate that the solutions are determined by first order non-linear
ordinary differential equations on some of the fields.


title: A duality theory for non-convex problems in the Calculus of Variations

abstract:
  We present a new duality theory for non-convex variational problems, under
possibly mixed Dirichlet and Neumann boundary conditions. The dual problem
reads nicely as a linear programming problem, and our main result states that
there is no duality gap. Further, we provide necessary and sufficient
optimality conditions, and we show that our duality principle can be
reformulated as a min-max result which is quite useful for numerical
implementations. As an example, we illustrate the application of our method to
a celebrated free boundary problem. The results were announced in \cite{BoFr}.


title: A mathematical evaluation of vote transfer systems

abstract:
  The paper builds a general model of vote transfer systems on the basis of the
current Hungarian electoral rules. It combines single-seat districts and list
mandates with three possible compensation rule for 'wasted' votes in
constituencies: no compensation (direct vote transfer, DVT), compensation for
votes cast for losing party candidates (positive vote transfer, PVT) and
compensation for all votes that are not necessary to win the district (negative
vote transfer, NVT).
  The model is studied in the case of two parties. When the number of votes for
the majority party follows a uniform distribution in each district, DVT results
in the greatest expected seat share, however, application of PVT, and,
especially, NVT increases the probability of winning the election. The
trade-off between vote transfer formulas and the number of list mandates
reveals that the majority party should use an appropriately calibrated NVT
system if it focuses on these two variables.


title:
In Cohen generic extension, every countable OD set of reals belongs to
  the ground model

abstract:
  It is true in the Cohen generic extension of L, the constructible universe,
that every countable ordinal-definable set of reals belongs to L.


title: X-ray spectral and optical properties of a ULX in NGC 4258 (M106)

abstract:
  We study the X-ray and optical properties of the ultraluminous X-ray source
(ULX) X-6 in the nearby galaxy NGC 4258 (M106) based on the archival {\it
XMM-Newton}, {\it Chandra}, {\it Swift}, and {\it Hubble Space Telescope} ({\it
HST}) observations. The source has a peak luminosity of $L_{\mathrm{X}} \sim 2
\times 10^{39}$ erg s$^{-1}$ in the {\it XMM-Newton} observation of 2004 June.
Consideration of the hardness ratios and spectral model parameters shows that
the source seems to exhibit possible spectral variations throughout the X-ray
observations. In the images from the {\it HST}/Advanced Camera for Surveys
(ACS), three optical sources have been identified as counterpart candidates
within the 1$\sigma$ error radius of 0$\arcsec$.3. The brightest one has an
absolute magnitude of $M_{V} \approx$ $-$7.0 and shows extended structure. The
remaining two sources have absolute magnitudes of $M_{V} \approx$ $-$5.8 and
$-$5.3 mag. The possible spectral types of the candidates from brightest to
dimmest were determined as B6$-$A5, B0$-$A7, and B2$-$A3, respectively. The
counterparts of the X-ray source possibly belong to a young star cluster.
Neither the standard disk model nor the slim disk model provides firm evidence
to determine the spectral characteristics of ULX X-6. We argue that the mass of
the compact object lies in the range $10-15M_{\sun}$ indicating that the
compact source is most likely a stellar-mass black hole.


title: Existence of torsional solitons in a beam model of suspension bridge

abstract:
  This paper studies the existence of solitons, namely stable solitary waves,
in a suspension bridge. The bridge is modeled as a degenerate plate, that is, a
central beam with cross sections, and displays two degrees of freedom: the
vertical displacement of the beam and the torsional angles of the cross
sections. Under fairy general assumptions, we prove the existence of solitons.
Under the additional assumption of large tension in the sustaining cables, we
prove that these solitons have a nontrivial torsional component. This appears
relevant for the security since several suspension bridges collapsed due to
torsional oscillations.


title:
Non-Concave Penalization in Linear Mixed-Effects Models and Regularized
  Selection of Fixed Effects

abstract:
  Mixed-effect models are very popular for analyzing data with a hierarchical
structure, e.g. repeated observations within subjects in a longitudinal design,
patients nested within centers in a multicenter design. However, recently, due
to the medical advances, the number of fixed effect covariates collected from
each patient can be quite large, e.g. data on gene expressions of each patient,
and all of these variables are not necessarily important for the outcome. So,
it is very important to choose the relevant covariates correctly for obtaining
the optimal inference for the overall study. On the other hand, the relevant
random effects will often be low-dimensional and pre-specified. In this paper,
we consider regularized selection of important fixed effect variables in linear
mixed-effects models along with maximum penalized likelihood estimation of both
fixed and random effect parameters based on general non-concave penalties.
Asymptotic and variable selection consistency with oracle properties are proved
for low-dimensional cases as well as for high-dimensionality of non-polynomial
order of sample size (number of parameters is much larger than sample size). We
also provide a suitable computationally efficient algorithm for implementation.
Additionally, all the theoretical results are proved for a general non-convex
optimization problem that applies to several important situations well beyond
the mixed model set-up (like finite mixture of regressions etc.) illustrating
the huge range of applicability of our proposal.


title:
RemoveYoung: A tool for the removal of the young stellar component in
  galaxies within an adjustable age cutoff

abstract:
  The optical morphology of galaxies holds the cumulative record of their
assembly history, and techniques for its quantitative characterization offer a
promising avenue toward understanding galaxy formation and evolution. However,
the morphology of star-forming galaxies is generally dictated by the youngest
stellar component, which can readily overshine faint structural/morphological
features in the older underlying stellar background (e.g., relics from recent
minor mergers) that could hold important insights into the galaxy build-up
process. Stripping off galaxy images from the emission from stellar populations
younger than an adjustable age cutoff tcut can, therefore, provide a valuable
tool in extragalactic research. RemoveYoung (RY), a publicly available tool
that is presented here, exploits the combined power of integral field
spectroscopy (IFS) and spectral population synthesis (SPS) toward this goal.
Two-dimensional (2D) post-processing of SPS models to IFS data cubes with RY
permits computation of the spectral energy, surface brightness, and stellar
surface density distribution of stellar populations older than a user-defined
tcut. This suggests a variety of applications of star-forming galaxies, such as
interacting or merging galaxy pairs and lower mass starburst galaxies near and
far; these include blue compact and tidal dwarf galaxies.


title: The Wulff construction for convex integrands

abstract:
  For any given Wulff shape $\mathcal{W}$, we can define the unique continuous
function $S^{n}\to \mathbb{R}_{+}$ called convex integrand, denoted by
$\gamma_{{}_{\mathcal{W}}}$. In this paper, we show that, for any Wulff shapes
$\mathcal{W}_{1}$ and $\mathcal{W}_{2}$, the equality
$d(\gamma_{{}_{\mathcal{W}_{1}}}, \gamma_{{}_{\mathcal{W}_{2}}})=
h(\mathcal{W}_{1}, \mathcal{W}_{2})$ holds, where $d$ is the maximum distance
of the function space consisting of convex integrands and $h$ is the
Pompeiu-Hausdorff distance of the space consisting of Wulff shapes. Moreover,
applications of this result are given.


title:
Reply to Comment on "Tip induced unconventional superconductivity on
  Weyl semimetal TaAs"

abstract:
  Recently, we presented a paper about the tip-induced superconducting phase on
TaAs single crystal (arXiv:1607.00513). A conductance plateau with double
conductance peaks at finite bias, sharp double dips and a zero bias conductance
peak were observed in the point contact spectra (PCS). These three features in
one PCS suggest the possibility of p-wave like superconductivity and Majorana
zero modes in the surface. Soon after our paper posted on arXiv, Gayen el al.
(arXiv:1607.01405) questioned the underlying mechanism of our observations
based on their experimental measurements in conventional superconductors(Pb and
Nb) and conclusively indicated that the superconductivity observed in our TaAs
crystal is conventional. We disagree with their quick conclusion without any
specific study on the TaAs materials. We will explain in the following that for
the clean (Z=0) point contact (PC) in ballistic limit, the superconducting
transition feature in temperature dependence of PC resistance is expected. And
the critical current effect claimed by Gayen el al. cannot explain the observed
PCS in our paper.


title: On the growth of the Kronecker coefficients

abstract:
  We study the rate of growth experienced by the Kronecker coefficients as we
add cells to the rows and columns indexing partitions. We do this by moving to
the setting of the reduced Kronecker coefficients.


title:
Coverings: variations on a result of Rogers and on the Epsilon-net
  theorem of Haussler and Welzl

abstract:
  We consider four problems. Rogers proved that for any convex body $K$, we can
cover ${\mathbb R}^d$ by translates of $K$ of density very roughly $d\ln d$.
First, we extend this result by showing that, if we are given a family of
positive homothets of $K$ of infinite total volume, then we can find
appropriate translation vectors for each given homothet to cover ${\mathbb
R}^d$ with the same (or, in certain cases, smaller) density.
  Second, we extend Rogers' result to multiple coverings of space by translates
of a convex body: we give a non-trivial upper bound on the density of the most
economical covering where each point is covered by at least a certain number of
translates.
  Third, we show that for any sufficiently large $n$, the sphere ${\mathbb
S}^2$ can be covered by $n$ strips of width $20n/\ln n$, where no point is
covered too many times.
  Finally, we give another proof of the previous result based on a
combinatorial observation: an extension of the Epsilon-net Theorem of Haussler
and Welzl. We show that for a hypergraph of bounded Vapnik--Chervonenkis
dimension, in which each edge is of a certain measure, there is a not-too large
transversal set which does not intersect any edge too many times.


title:
Nonlinear embeddings: Applications to analysis, fractals and polynomial
  root finding

abstract:
  We introduce $\mathcal{B}_{\kappa}$-embeddings, nonlinear mathematical
structures that connect, through smooth paths parameterized by $\kappa$, a
finite or denumerable set of objects at $\kappa=0$ (e.g. numbers, functions,
vectors, coefficients of a generating function...) to their ordinary sum at
$\kappa \to \infty$. We show that $\mathcal{B}_{\kappa}$-embeddings can be used
to design nonlinear irreversible processes through this connection. A number of
examples of increasing complexity are worked out to illustrate the
possibilities uncovered by this concept. These include not only smooth
functions but also fractals on the real line and on the complex plane. As an
application, we use $\mathcal{B}_{\kappa}$-embeddings to formulate a robust
method for finding all roots of a univariate polynomial without factorizing or
deflating the polynomial. We illustrate this method by finding all roots of a
polynomial of 19th degree.


title:
Note on three-generation models in heterotic string and F-theory on
  elliptic Calabi-Yau manifolds over Hirzebruch varieties

abstract:
  We give a complete list of a class of three-generation models in E8 x E8
heterotic string theory and its dual F-theory on an elliptic Calabi-Yau over a
(generalized) Hirzebruch variety in which the divisors of the relevant line
bundles needed for a smooth Weierstrass model are effective. The most stringent
constraint on the bound of the eta class comes from the effectiveness of the
divisor of the bundle corresponding to the highest Casimir in Looijenga's
weighted projective space, as well as from the compactness of the toric
variety. Comparison is also made with the list obtained in the literature.


title:
Effects of an induced electric field on \pi^{-}/\pi^{+} ratio in
  heavy-ion collisions

abstract:
  Using an isospin- and momentum-dependent transport model, we examine the
effects of an electric field induced by a variable magnetic field on the
\pi^{-}/\pi^{+} ratio in central to peripheral heavy-ion collisions at beam
energies of 400 and 1500MeV/nucleon. It is shown that while the induced
electric field does not affect the total multiplicities of both $\pi^{-}$ and
$\pi^{+}$ mesons at both the lower beam energy of 400MeV/nucleon and the higher
beam energy of 1500MeV/nucleon, it reduces (enhances) the emission of $\pi^{-}$
($\pi^{+}$) mesons in midrapidity, but enhances (reduces) the emission of
$\pi^{-}$ ($\pi^{+}$) mesons in forward and backward rapidities especially for
the more peripheral collisions at the lower beam energy because of the rapidly
transient variable magnetic field at more peripheral collisions and longer
reaction duration time at the lower beam energy. These findings indicate that
the total \pi^{-}/\pi^{+} ratio is still a precisely reliable probe of symmetry
energy at both the lower and higher beam energies, but one should consider the
induced electric field when using the differential \pi^{-}/\pi^{+} ratio to
probe the symmetry energy especially for the lower beam energy and more
peripheral collisions. Finally, the relative suppression factor based on the
ratio of \pi^{-}/\pi^{+} in different rapidities is proposed to be an effective
probe of the induced electric field generated in heavy-ion collisions due to
its maximizing effects of induced electric fields on the differential
\pi^{-}/\pi^{+} ratio but minimizing effects of some uncertainty factors in
heavy-ion collisions.


title:
Filter-feeding, near-field flows, and the morphologies of colonial
  choanoflagellates

abstract:
  Efficient uptake of nutrients from the environment is an important component
in the fitness of all microorganisms, and its dependence on size may reveal
clues to the origins of evolutionary transitions to multicellularity. Because
potential benefits in uptake rates must be viewed in the context of other costs
and benefits of size, such as varying predation rates and the increased
metabolic costs associated with larger and more complex body plans, the uptake
rate itself is not necessarily that which is optimized by evolution. Uptake
rates can be strongly dependent on local organism geometry and its swimming
speed, providing selective pressure for particular arrangements. Here we
examine these issues for choanoflagellates, filter-feeding microorganisms that
are the closest relatives of the animals. We explore the different
morphological variations of the choanoflagellete $Salpingoeca~rosetta$, which
can exist as a swimming cell, a sessile thecate cell, and as colonies of cells
in various shapes. In the absence of other requirements and in a homogeneously
nutritious environment, we find that the optimal strategy to maximize filter
feeding by the collar of microvilli is to swim fast, which favours swimming
unicells. In large external flows, the sessile thecate cell becomes
advantageous. Effects of prey diffusion are discussed and also found to be to
the advantage of the swimming unicell.


title:
Deterministic Annealing Optimization for Witsenhausen's and Related
  Decentralized Stochastic Control Problems

abstract:
  This note studies the global optimization of controller mappings in
discrete-time stochastic control problems including Witsenhausen's celebrated
1968 counter-example. We propose a generally applicable non-convex numerical
optimization method based on the concept of deterministic annealing-which is
derived from information-theoretic principles and was successfully employed in
several problems including vector quantization, classification, and regression.
We present comparative numerical results for two test problems that show the
strict superiority of the proposed method over prior approaches in the
literature.


title:
A new MC-based method to evaluate the fission fraction uncertainty at
  reactor neutrino experiment

abstract:
  Uncertainties of fission fraction is an important uncertainty source for the
antineutrino flux prediction in a reactor antineutrino experiment. A new
MC-based method of evaluating the covariance coefficients between isotopes was
proposed. It was found that the covariance coefficients will varying with
reactor burnup and which may change from positive to negative because of
fissioning balance effect, for example, the covariance coefficient between
$^{235}$U and $^{239}$Pu changes from 0.15 to -0.13. Using the equation between
fission fraction and atomic density, the consistent of uncertainty of fission
fraction and the covariance matrix were obtained. The antineutrino flux
uncertainty is 0.55\% which does not vary with reactor burnup, and the new
value is about 8.3\% smaller.


title:
Lagrangian Decomposition based Multi Agent Model Predictive Control for
  Electric Vehicles Charging integrating Real Time Pricing

abstract:
  This paper presents a real time distributed control strategy for electric
vehicles charging covering both drivers and grid players' needs. Computation of
the charging load curve is performed by agents working at the level of each
single vehicle, with the information exchanged with grid players being
restricted to the chosen load curve and energy price feedback from the market,
elaborated according to the charging infrastructure congestion. The distributed
control mechanism is based on model predictive control methodology and
Lagrangian decomposition of the optimization control problem at its basis. The
simulation results show the effectiveness of the proposed distributed approach
and the mutual coherence between the computed charging load curves and the
resulting energy price over the time.


title:
Conjugacy properties of time-evolving Dirichlet and gamma random
  measures

abstract:
  We extend classic characterisations of posterior distributions under
Dirichlet process and gamma random measures priors to a dynamic framework. We
consider the problem of learning, from indirect observations, two families of
time-dependent processes of interest in Bayesian nonparametrics: the first is a
dependent Dirichlet process driven by a Fleming-Viot model, and the data are
random samples from the process state at discrete times; the second is a
collection of dependent gamma random measures driven by a Dawson-Watanabe
model, and the data are collected according to a Poisson point process with
intensity given by the process state at discrete times. Both driving processes
are diffusions taking values in the space of discrete measures whose support
varies with time, and are stationary and reversible with respect to Dirichlet
and gamma priors respectively. A common methodology is developed to obtain in
closed form the time-marginal posteriors given past and present data. These are
shown to belong to classes of finite mixtures of Dirichlet processes and gamma
random measures for the two models respectively, yielding conjugacy of these
classes to the type of data we consider. We provide explicit results on the
parameters of the mixture components and on the mixing weights, which are
time-varying and drive the mixtures towards the respective priors in absence of
further data. Explicit algorithms are provided to recursively compute the
parameters of the mixtures. Our results are based on the projective properties
of the signals and on certain duality properties of their projections.


title:
Continuous measurements of real-life bidirectional pedestrian flows on a
  wide walkway

abstract:
  Employing partially overlapping overhead \kinectTMS sensors and automatic
pedestrian tracking algorithms we recorded the crowd traffic in a rectilinear
section of the main walkway of Eindhoven train station on a 24/7 basis. Beside
giving access to the train platforms (it passes underneath the railways), the
walkway plays an important connection role in the city. Several crowding
scenarios occur during the day, including high- and low-density dynamics in
uni- and bi-directional regimes. In this paper we discuss our recording
technique and we illustrate preliminary data analyses. Via fundamental
diagrams-like representations we report pedestrian velocities and fluxes vs.
pedestrian density. Considering the density range $0$ - $1.1\,$ped/m$^2$, we
find that at densities lower than $0.8\,$ped/m$^2$ pedestrians in
unidirectional flows walk faster than in bidirectional regimes. On the
opposite, velocities and fluxes for even bidirectional flows are higher above
$0.8\,$ped/m$^2$.


title:
Phase dependent advection-diffusion in drift wave - zonal flow
  turbulence

abstract:
  In plasma turbulence theory, due to the complexity of the system with many
non-linearly interacting waves, the dynamics of the phases is often disregarded
and the so-called random-phase approximation (RPA) is used assuming the
existence of a Chirikov-like criterion for the onset of wave stochasticity. The
dynamical amplitudes are represented as complex numbers, $\psi = \psi_r +
i\psi_i = ae^{i\theta}$, with the amplitudes slowly varying whereas the phases
are rapidly varying and, in particular, distributed uniformly over the interval
$[0;2\pi)$. However, one could expect that the phase dynamics can play a role
in the self-organisation and the formation of coherent structures. In the same
manner it is also expected that the RPA falls short to take coherent
interaction between phases into account. In this work therefore, we studied the
role of phase dynamics and the coupling of phases between different modes on
the characteristic time evolution of the turbulent. We assume a simple
turbulent system where the so-called stochastic oscillator model can be
employed. The idea of interpreting turbulence by stochastic oscillators. The
stochastic oscillator models can be derived from radical simplifications of the
nonlinear terms in the Navier-Stokes or Gyro-Kinetic equations. In this
particular case we adopt the basic equation for the stochastic oscillator model
with passive advection and random forcing from Ref.


title:
Collapse of the mean curvature flow for certain kind of invariant
  hypersurfaces in a Hilbert space

abstract:
  In this paper, we investigate the regularized mean curvature flow starting
from an invariant hypersurface in a Hilbert space equipped with an isometric
and almost free action of a Hilbert Lie group whose orbits are regularized
minimal. We prove that, if the invariant hypersurface satisfies a certain kind
of horizontally convexity condition, then it collapses to an orbit of the
Hilbert Lie group action along the regularized mean curvature flow.


title:
Reaction and fusion cross sections for the near-symmetric system
  $^{129}Xe+^{nat}Sn$ from $8$ to $35$ $AMeV$

abstract:
  \item[Background]Heavy-ion reactions from barrier up to Fermi energy.
\item[Purpose]Reaction and fusion cross sections determination. Fusion
reactions induced by $^{129}Xe$ projectiles on $^{nat}Sn$ targets for energies
ranging from $8$ A.MeV to $35$ A.MeV were measured with the INDRA
$4\pi$-array.\\ The evaluation of the fusion/incomplete fusion cross sections
for the incident energies from 8 to 35 A.MeV is the main purpose of this paper.
\item[Method] The reaction cross sections are evaluated for each beam energy
thanks to INDRA $4\pi$-array. The events are also sorted in order to focus the
study on a selected sample of events, in such a way that the fusion/fusion
incomplete cross section is estimated. \item[Results] The excitation function
of reaction and fusion cross sections were measured for the heavy and nearly
symmetric system $^{129}Xe + ^{nat}Sn$ from 8 to 35 A.MeV.
  \item[Conclusions] The fusion-like cross-sections evaluated show a good
agrement with a recent systematics for beam energies greater than 20 A.MeV. For
low beam energies the cross-section values are lower than the expected ones. A
probable reason for these low values is in the fusion hindrance at energies
above/close the barrier.


title:
The electronic structure of BSCCO in the presence of a super-current:
  Flux-flow, Doppler shift and quasiparticle pockets

abstract:
  There are several ways to turn a superconductor into a normal conductor:
increase the temperature, apply a high magnetic field, or run a large current.
High-T$_c$ cuprate superconductors are unusual in the sense that experiments
suggest that destroying superconductivity by heating the sample to temperatures
above T$_c$ or by applying a high magnetic field result in different 'normal'
states. Spectroscopic probes show that above T$_c$, in the pseudogap regime,
the Fermi surface is partly gapped and there are no well-defined
quasiparticles. Transport measurements, on the contrary, reveal quantum
oscillations in high magnetic fields and at low temperatures, suggesting a more
usual Fermi liquid state. Studying the electronic structure while suppressing
superconductivity by using current, will hopefully shed new light on this
problem. In type II superconductors, such as the cuprates, the resistive state
created by the current is a result of vortex motion. The large dissipation in
the flux-flow regime makes spectroscopic measurements in the presence of
current challenging. We performed angle-resolved photoemission experiments in
thin films of Bi$_2$Sr$_2$CaCu$_2$O$_y$ while running high-density current
through the samples. Clear evidence was found for non-uniform flux flow,
leaving most of the sample volume free of mobile vortices and dissipation. The
super-current changes the electronic spectrum, creating quasiparticle and
quasihole pockets. The size of these pockets as a function of the current is
found to be doping dependent; it depends both on the superfluid stiffness and
on the strength of interactions.


title: sk_p: a neural program corrector for MOOCs

abstract:
  We present a novel technique for automatic program correction in MOOCs,
capable of fixing both syntactic and semantic errors without manual, problem
specific correction strategies. Given an incorrect student program, it
generates candidate programs from a distribution of likely corrections, and
checks each candidate for correctness against a test suite.
  The key observation is that in MOOCs many programs share similar code
fragments, and the seq2seq neural network model, used in the natural-language
processing task of machine translation, can be modified and trained to recover
these fragments.
  Experiment shows our scheme can correct 29% of all incorrect submissions and
out-performs state of the art approach which requires manual, problem specific
correction strategies.


title:
Magnetorotational dynamo chimeras. The missing link to turbulent
  accretion disk dynamo models?

abstract:
  In Keplerian accretion disks, turbulence and magnetic fields may be jointly
excited through a subcritical dynamo process involving the magnetorotational
instability (MRI). High-resolution simulations exhibit a tendency towards
statistical self-organization of MRI dynamo turbulence into large-scale cyclic
dynamics. Understanding the physical origin of these structures, and whether
they can be sustained and transport angular momentum efficiently in
astrophysical conditions, represents a significant theoretical challenge. The
discovery of simple periodic nonlinear MRI dynamo solutions has recently proven
useful in this respect, and has notably served to highlight the role of
turbulent magnetic diffusion in the seeming decay of the dynamics at low
magnetic Prandtl number Pm (magnetic diffusivity larger than viscosity), a
common regime in accretion disks. The connection between these simple
structures and the statistical organization reported in turbulent simulations
remained elusive, though. Here, we report the numerical discovery in moderate
aspect ratio Keplerian shearing boxes of new periodic, incompressible,
three-dimensional nonlinear MRI dynamo solutions with a larger dynamical
complexity reminiscent of such simulations. These "chimera" cycles are
characterized by multiple MRI-unstable dynamical stages, but their basic
physical principles of self-sustainment are nevertheless identical to those of
simpler cycles found in azimuthally elongated boxes. In particular, we find
that they are not sustained at low Pm either due to subcritical turbulent
magnetic diffusion. These solutions offer a new perspective into the transition
from laminar to turbulent instability-driven dynamos, and may prove useful to
devise improved statistical models of turbulent accretion disk dynamos.


title:
The Vectorization of the Tersoff Multi-Body Potential: An Exercise in
  Performance Portability

abstract:
  Molecular dynamics simulations, an indispensable research tool in
computational chemistry and materials science, consume a significant portion of
the supercomputing cycles around the world. We focus on multi-body potentials
and aim at achieving performance portability. Compared with well-studied pair
potentials, multibody potentials deliver increased simulation accuracy but are
too complex for effective compiler optimization. Because of this, achieving
cross-platform performance remains an open question. By abstracting from target
architecture and computing precision, we develop a vectorization scheme
applicable to both CPUs and accelerators. We present results for the Tersoff
potential within the molecular dynamics code LAMMPS on several architectures,
demonstrating efficiency gains not only for computational kernels, but also for
large-scale simulations. On a cluster of Intel Xeon Phi's, our optimized solver
is between 3 and 5 times faster than the pure MPI reference.


title:
High pressure studies on properties of FeGa3: role of on-site coulomb
  correlation

abstract:
  High pressure X-ray diffraction measurements have been carried out on the
intermetallic semiconductor FeGa$_3$ and the equation of state for FeGa$_3$ has
been determined. First principles based DFT calculations within the GGA
approximation indicate that although the unit cell volume matches well with the
experimentally obtained value at ambient pressure, it is significantly
underestimated at high pressures and the difference between them increases as
pressure increases. GGA + U calculations with increasing values of U$_{Fe(3d)}$
(on-site Coulomb repulsion between the Fe 3d electrons) at high pressures,
correct this discrepancy. Further, the GGA+U calculations also show that along
with U$_{Fe(3d)}$, the Fe 3d band width also increases with pressure and around
a pressure of 4 GPa, a small density of states appear at the Fermi level. High
pressure resistance measurements carried out on FeGa$_3$ also clearly show a
signature of an electronic transition. Beyond the pressure of 19.7 GPa, the
diffraction peaks reduce in intensity and are not observable beyond $\sim$ 26
GPa, leading to an amorphous state.


title: On the amplification of acoustic phonons in carbon nanotube

abstract:
  We present a theoretical study of acoustic phonons amplification in Carbon
Nanotubes (CNT). The phenomenon is via Cerenkov emission (CE) of acoustic
phonons using intraband transitions proposed by Mensah et. al.,~\cite{1} in
Semiconductor Superlattices (SSL) and confirmed in ~\cite{2}. From this, an
asymmetric graph of $\Gamma^{CNT}$ on $\frac{V_d}{V_s}$ and $\Omega\tau$ were
obtained where amplification ($\Gamma_{amp}^{CNT}$) $>>$ absorption
($\Gamma_{abs}^{CNT}$). The ratio, $\frac{\vert
\Gamma_{amp}^{CNT}\vert}{\vert\Gamma_{abs}^{CNT}\vert}\approx 3.5$, at $V_d =
1.02V_s$, $\omega_q = 3.0\ \mathrm{THz}$ and $T = 85\ K$ for scattering angle
$\theta > 0$ . A threshold field at which $\Gamma_{abs}^{CNT}$ switches over to
$\Gamma_{amp}^{CNT}$ was calculated to be $E_{z}^{dc} = 6.2\times 10^3\
\mathrm{V/m}$. This field is far less than that deduced using Bloch-Type
Oscillation (BTO)~\cite{3} which is $E_{BTO}^{dc} = 3.0\times 10^5\
\mathrm{V/m}$. The obtained $\Gamma_{amp}^{CNT}$ would enable the use of CNT
for the production of SASER.


title: On contact and symplectic Lie algebroids

abstract:
  In this paper, we will study compatible triples on Lie algebroids. Using a
suitable decomposition for a Lie algebroid, we construct an integrable
generalized distribution on the base manifold. As a result, the symplectic form
on the Lie algebroid induces a symplectic form on each integral submanifold of
the distribution. The induced Poisson structure on the base manifold can be
represented by means of the induced Poisson structures on the integral
submanifolds. Moreover, for any compatible triple with invariant metric and
admissible almost complex structure, we show that the bracket annihilates on
the kernel of the anchor map.


title:
Josephson plasma oscillations and the Gross-Pitaevskii equation:
  Bogoliubov approach vs two-mode model

abstract:
  We show that the Josephson plasma frequency for a condensate in a double-well
potential, whose dynamics is described by the Gross-Pitaevskii (GP) equation,
can be obtained with great precision by means of the usual Bogoliubov approach,
whereas the two-mode model - commonly constructed by means of a linear
combinations of the low-lying states of the GP equation - generally provides
accurate results only for weak interactions. A proper two-mode model in terms
of the Bogoliubov functions is also discussed, revealing that in general a
two-mode approach is formally justified only for not too large interactions,
even in the limit of very small amplitude oscillations. Here we consider
specifically the case of a one-dimensional system, but the results are expected
to be valid in arbitrary dimensions.


title:
A new class of Fermionic Projectors: M{\o}ller operators and mass
  oscillation properties

abstract:
  Recently, a new functional analytic construction of quasi-free states for a
self-dual CAR algebra has been presented in \cite{Felix2}. This method relies
on the so-called strong mass oscillation property. We provide an example where
this requirement is not satisfied, due to the nonvanishing trace of the
solutions of the Dirac equation on the horizon of Rindler space, and we propose
a modification of the construction in order to weaken this condition. Finally,
a connection between the two approaches is built.


title:
$GL_2$-real analytic Eisenstein series twisted by parameter matrices and
  multiplicative integral quasi-characters

abstract:
  In this monograph, we study in detail a special class of $GL_2$-real analytic
Eisenstein series.


title:
Computing the atom graph of a graph and the union join graph of a
  hypergraph

abstract:
  The atom graph of a graph is the graph whose vertices are the atoms obtained
by clique minimal separator decomposition of this graph, and whose edges are
the edges of all possible atom trees of this graph. We provide two efficient
algorithms for computing this atom graph, with a complexity in $O(min(n^\alpha
\log n, nm, n(n+\overline{m}))$ time, which is no more than the complexity of
computing the atoms in the general case. %\par We extend our results to
$\alpha$-acyclic hypergraphs. We introduce the notion of union join graph,
which is the union of all possible join trees; we apply our algorithms for atom
graphs to efficiently compute union join graphs.
  Keywords: clique separator decomposition, atom tree, atom graph, clique tree,
clique graph, $\alpha$-acyclic hypergraph.


title:
Probing the spectral density of a dissipative qubit via quantum
  synchronization

abstract:
  The interaction of a quantum system, which is not accessible by direct
measurement, with an external probe can be exploited to infer specific features
of the system itself. We introduce a probing scheme based on the emergence of
spontaneous quantum synchronization between an out-of-equilibrium qubit, in
contact with an external environment, and a probe qubit. Tuning the frequency
of the probe leads to a transition between synchronization in phase and
antiphase. The sharp transition between these two regimes is locally accessible
by monitoring the probe dynamics alone and allows one to reconstruct the shape
of the spectral density of the environment.


title: Acoustic Eaton lens array and its fluid application

abstract:
  A principle of an acoustic Eaton Lens array and its application as a
removable tsunami wall is proposed theoretically. The lenses are made of
expandable rubber pillars or balloons and create a stop-band by the rotating
the incoming tsunami wave and reduce the pressure by canceling each other. The
diameter of each lens is larger than the wavelength of the tsunami near the
coast, that is, order of a kilometer. The impedance matching on the border of
the lenses results in little reflection. Before a tsunami, the balloons are
buried underground in shallow water near the coast in folded or rounded form.
Upon sounding of the tsunami alarm, water and air are pumped into the pillars,
which expand and erect the wall above the sea level within a few hours. After
the tsunami, the water and air are released from the pillars, which are then
buried underground for reuse. Electricity is used to power the entire process.
A numerical simulation with a linear tsunami model was carried out.


title:
Minimum Description Length Principle in Supervised Learning with
  Application to Lasso

abstract:
  The minimum description length (MDL) principle in supervised learning is
studied. One of the most important theories for the MDL principle is Barron and
Cover's theory (BC theory), which gives a mathematical justification of the MDL
principle. The original BC theory, however, can be applied to supervised
learning only approximately and limitedly. Though Barron et al. recently
succeeded in removing a similar approximation in case of unsupervised learning,
their idea cannot be essentially applied to supervised learning in general. To
overcome this issue, an extension of BC theory to supervised learning is
proposed. The derived risk bound has several advantages inherited from the
original BC theory. First, the risk bound holds for finite sample size. Second,
it requires remarkably few assumptions. Third, the risk bound has a form of
redundancy of the two-stage code for the MDL procedure. Hence, the proposed
extension gives a mathematical justification of the MDL principle to supervised
learning like the original BC theory. As an important example of application,
new risk and (probabilistic) regret bounds of lasso with random design are
derived. The derived risk bound holds for any finite sample size $n$ and
feature number $p$ even if $n\ll p$ without boundedness of features in contrast
to the past work. Behavior of the regret bound is investigated by numerical
simulations. We believe that this is the first extension of BC theory to
general supervised learning with random design without approximation.


title:
Interpretation of the historic Yemeni reports of supernova SN 1006:
  early discovery in mid-April 1006 ?

abstract:
  The recently published Yemeni observing report about SN 1006 from al-Yamani
clearly gives AD 1006 Apr $17 \pm 2$ (mid-Rajab 396h) as first observation
date. Since this is about 1.5 weeks earlier than the otherwise earliest reports
(Apr 28 or 30) as discussed so far, we were motivated to investigate an early
sighting in more depth. We searched for additional evidences from other areas
like East Asia and Europe. We found that the date given by al-Yamani is fully
consistent with other evidence, including: (a) SN 1006 "rose several times half
an hour after sunset" (al-Yamani), which is correct for the location of Sana in
Yemen for the time around Apr 17, but it would not be correct for late Apr or
early May; (b) the date (3rd year, 3rd lunar month, 28th day wuzi, Ichidai
Yoki) for an observation of a guest star in Japan is inconsistent (there is no
day wuzi in that lunar month), but may be dated to Apr 16 by reading wuwu date
rather than a wuzi date; (c) there is observational evidence that SN 1006 was
observed in East Asia early or mid April; for the second half of April, a bad
weather (early monsoon) period is not unlikely -- there is a lack of night
reports; (d) the observer in St. Gallen reported to have seen SN 1006 "for
three months", which must have ended at the very latest on AD 1006 Jul 10,
given his northern location, so that his observations probably started in
April. We conclude that the correctly reported details give quite high
confidence in the fully self-consistent report of al-Yamani, so that the early
discovery date should be considered seriously.


title:
Experimental characterization of negative refractive index material NRM
  at Ka band

abstract:
  In this paper, we discuss the experimental characterization of a negative
refractive material NRM at Ka band using LR labyrinth Ring and wire array WA.
We describe in detail the the LR and wire array characterization separately,
and after that the combined experimental results, for NRM are reported. The LRs
analytical and simulation study is not new but design in Ka band and different
experimental procedure for the characterization of the negative refractive
index is the novelty of this paper. For performing a negative refractive index
experiment we made prism of 150 Prism angle . We get enhanced transmittance of
more than 20 dB from background, at a negative angle of refraction. The values
of the negative refractive index in a band of about 1 G Hz around 31 GHz are
retrieved from the experimental data.


title: Stable Matching with Uncertain Linear Preferences

abstract:
  We consider the two-sided stable matching setting in which there may be
uncertainty about the agents' preferences due to limited information or
communication. We consider three models of uncertainty: (1) lottery model ---
in which for each agent, there is a probability distribution over linear
preferences, (2) compact indifference model --- for each agent, a weak
preference order is specified and each linear order compatible with the weak
order is equally likely and (3) joint probability model --- there is a lottery
over preference profiles. For each of the models, we study the computational
complexity of computing the stability probability of a given matching as well
as finding a matching with the highest probability of being stable. We also
examine more restricted problems such as deciding whether a certainly stable
matching exists. We find a rich complexity landscape for these problems,
indicating that the form uncertainty takes is significant.


title:
Multi Weyl Points and the Sign Change of Their Topological Charges in
  Woodpile Photonic Crystals

abstract:
  We show that Weyl points with topological charges 1 and 2 can be found in
very simple chiral woodpile photonic crystals, which can be fabricated using
current techniques down to the nano-scale. The sign of the topological charges
can be tuned by changing the material parameters of the crystal, keeping the
structure and the symmetry unchanged. The underlying physics can be understood
using a tight binding model, which shows that the sign of the charge depends on
the hopping range. Gapless surface states and their back-scattering immune
properties are also demonstrated in these systems.


title:
Towards Real-Time Estimation of Solar Generation From
  Micro-Synchrophasor Measurements

abstract:
  This paper presents a set of methods for estimating the renewable energy
generation downstream of a measurement device using real-world measurements.
First, we present a generation disaggregation scheme where the only information
available for estimation is the micro-synchrophasor measurements obtained at
the substation or feeder head. We then propose two strategies in which we use
measurements from the substation as well as a proxy solar irradiance
measurement. Using these two measurement points, we first propose a multiple
linear regression strategy, in which we estimate a relationship between the
measured reactive power and the load active power consumption, which are then
used in disaggregation. Finally, we expand this strategy to strategically
manage the reconstruction errors in the estimators. We simultaneously
disaggregate the solar generation and load. We show that it is possible to
disaggragate the generation of a 7.5 megawatt photovoltaic site with a
root-mean-squared error of approximately 450 kilowatts.


title:
Wireless Power Transfer in Massive MIMO Aided HetNets with User
  Association

abstract:
  This paper explores the potential of wireless power transfer (WPT) in massive
multiple input multiple output (MIMO) aided heterogeneous networks (HetNets),
where massive MIMO is applied in the macrocells, and users aim to harvest as
much energy as possible and reduce the uplink path loss for enhancing their
information transfer. By addressing the impact of massive MIMO on the user
association, we compare and analyze two user association schemes. We adopt the
linear maximal ratio transmission beam-forming for massive MIMO power transfer
to recharge users. By deriving new statistical properties, we obtain the exact
and asymptotic expressions for the average harvested energy. Then we derive the
average uplink achievable rate under the harvested energy constraint.


title: The $4n^2$-inequality for complete intersection singularities

abstract:
  The famous $4n^2$-inequality is extended to generic complete intersection
singularities: it is shown that the multiplicity of the self-intersection of a
mobile linear system with a maximal singularity is higher than $4n^2\mu$, where
$\mu$ is the multiplicity of the singular point.


title: Characterization and recognition of proper tagged probe interval graphs

abstract:
  Interval graphs were used in the study of genomics by the famous molecular
biologist Benzer. Later on probe interval graphs were introduced by Zhang as a
generalization of interval graphs for the study of cosmid contig mapping of
DNA.
  A tagged probe interval graph (briefly, TPIG) is motivated by similar
applications to genomics, where the set of vertices is partitioned into two
sets, namely, probes and nonprobes and there is an interval on the real line
corresponding to each vertex. The graph has an edge between two probe vertices
if their corresponding intervals intersect, has an edge between a probe vertex
and a nonprobe vertex if the interval corresponding to a nonprobe vertex
contains at least one end point of the interval corresponding to a probe vertex
and the set of non-probe vertices is an independent set. This class of graphs
have been defined nearly two decades ago, but till today there is no known
recognition algorithm for it.
  In this paper, we consider a natural subclass of TPIG, namely, the class of
proper tagged probe interval graphs (in short PTPIG). We present
characterization and a linear time recognition algorithm for PTPIG. To obtain
this characterization theorem we introduce a new concept called canonical
sequence for proper interval graphs, which, we belief, has an independent
interest in the study of proper interval graphs. Also to obtain the recognition
algorithm for PTPIG, we introduce and solve a variation of consecutive $1$'s
problem, namely, oriented consecutive $1$'s problem and some variations of
PQ-tree algorithm. We also discuss the interrelations between the classes of
PTPIG and TPIG with probe interval graphs and probe proper interval graphs.


title:
An optimal transport approach to Monge-Amp\`ere equations on compact
  Hessian manifolds

abstract:
  In this paper we consider Monge-Amp\`ere equations on compact Hessian
manifolds, or equivalently Monge-Amp\`ere equations on certain unbounded convex
domains $\Omega\subseteq \mathbb{R}^n$, with a periodicity constraint given by
the action of an affine group. In the case where the affine group action is
volume-preserving, i.e., when the manifold is special, the solvability of the
corresponding Monge-Amp\`ere equation was established using the continuity
method by Cheng and Yau. In the general case we set up a variational framework
involving certain dual manifolds and a generalization of the classical Legendre
transform. We give existence and uniqueness results, elaborate on connections
to optimal transport and quasi-periodic tilings of convex domains.


title:
Observation of electron excitation into silicon conduction band by
  slow-ion surface neutralization

abstract:
  Bare reverse biased silicon photodiodes were exposed to 3eV He+, Ne+, Ar+,
N2+, N+ and H2O+ ions. In all cases an increase of the reverse current through
the diode was observed. This effect and its dependence on the ionization energy
of the incident ions and on other factors are qualitatively explained in the
framework of Auger-type surface neutralization theory. Amplification of the
ion-induced charge was observed with an avalanche photodiode under high applied
bias. The observed effect can be considered as ion-induced internal potential
electron emission into the conduction band of silicon. To the best of our
knowledge, no experimental evidence of such effect was previously reported.
Possible applications are discussed.


title: Faster Low-rank Approximation using Adaptive Gap-based Preconditioning

abstract:
  We propose a method for rank $k$ approximation to a given input matrix $X \in
\mathbb{R}^{d \times n}$ which runs in time \[ \tilde{O} \left(d ~\cdot~
\min\left\{n + \tilde{sr}(X) \,G^{-2}_{k,p+1}\ ,\ n^{3/4}\, \tilde{sr}(X)^{1/4}
\,G^{-1/2}_{k,p+1} \right\} ~\cdot~ \text{poly}(p)\right) ~, \] where $p>k$,
$\tilde{sr}(X)$ is related to stable rank of $X$, and $G_{k,p+1} =
\frac{\sigma_k-\sigma_p}{\sigma_k}$ is the multiplicative gap between the
$k$-th and the $(p+1)$-th singular values of $X$. In particular, this yields a
linear time algorithm if the gap is at least $1/\sqrt{n}$ and
$k,p,\tilde{sr}(X)$ are constants.


title: Viscoelastic nematodynamics

abstract:
  Nematic liquid crystals exhibit both crystal-like and fluid-like features. In
particular, the propagation of an acoustic wave shows an unexpected occurrence
of some of the solid-like features at the hydrodynamic level, namely, the
frequency-dependent anisotropy of sound velocity and acoustic attenuation. The
non-Newtonian behavior of nematics also emerges from the frequency-dependent
viscosity coefficients. To account for these phenomena, we put forward a
viscoelastic model of nematic liquid crystals, and we extend our previous
theory to fully include the combined effects of compressibility, anisotropic
elasticity and dynamic relaxation, at any shear rate. The low-frequency limit
agrees with the compressible Ericksen-Leslie theory, while at intermediate
frequencies the model correctly captures the relaxation mechanisms underlying
finite shear and bulk elastic moduli. We show that there are only four
relaxation times allowed by the uniaxial symmetry.


title: On the chemistry of typestate-oriented actors

abstract:
  Typestate-oriented programming is an extension of the OO paradigm in which
objects are modeled not just in terms of interfaces but also in terms of their
usage protocols, describing legal sequences of method calls, possibly depending
on the object's internal state. We argue that the Actor Model allows
typestate-OOP in an inherently distributed setting, whereby objects/actors can
be accessed concurrently by several processes, and local entities cooperate to
carry out a communication protocol. In this article we illustrate the approach
by means of a number of examples written in Scala Akka. We show that Scala's
abstractions support clean and natural typestate-oriented actor programming
with the usual asynchronous and non-blocking semantics. We also show that the
standard type system of Scala and a typed wrapping of usual (untyped) Akka's
ActorRef are enough to provide rich forms of type safety so that well-typed
actors respect their intended communication protocols. This approach draws on a
solid theoretical background, consisting of a sound behavioral type system for
the Join Calculus, that is a foundational calculus of distributed asynchronous
processes whose semantics is based on the Chemical Abstract Machine, that
unveiled its strong connections with typestate-oriented programming of both
concurrent objects and actors.


title:
Evidence of Wigner Rotation Phenomena in the Beam Splitting Experiment
  at the LCLS

abstract:
  A result from particle tracking states that, after a microbunched electron
beam is kicked, its trajectory changes while the orientation of the
microbunching wavefront remains as before. Experiments at the LCLS showed that
radiation in the kicked direction is produced practically without suppression.
This could be explained if the orientation of the microbunching wavefront is
readjusted along the kicked direction. In previous papers we showed that when
the evolution of the electron beam modulation is treated according to
relativistic kinematics, the orientation of the microbunching wavefront in the
ultrarelativistic asymptotic is always perpendicular to the electron beam
velocity. There we refrained from using advanced theoretical concepts to
explain or analyze the wavefront rotation. For example, we only hinted to the
relation of this phenomenon with the concept of Wigner rotation. This more
abstract view of wavefront rotation underlines its elementary nature. The
Wigner rotation is known as a fundamental effect in elementary particle
physics. The composition of non collinear boosts does not result in a simple
boost but, rather, in a Lorentz transformation involving a boost and a
rotation, the Wigner rotation. Here we show that during the LCLS experiments, a
Wigner rotation was actually directly recorded for the first time with a
ultrarelativistic, macroscopic object: an ultrarelativistic electron bunch in
an XFEL modulated at nm-scale of the size of about 10 microns. Here we point
out the role of Wigner rotation in the analysis and interpretation of
experiments with ultrarelativistic, microbunched electron beams in FELs. After
the beam splitting experiment at the LCLS it became clear that, in the
ultrarelativistic asymptotic, the projection of the microbunching wave vector
onto the beam velocity is a Lorentz invariant, similar to the helicity in
particle physics.


title:
Quasi-exactly solvable symmetrized quartic and sextic polynomial
  oscillators

abstract:
  The symmetrized quartic polynomial oscillator is shown to admit an sl(2,$\R$)
algebraization. Some simple quasi-exactly solvable (QES) solutions are
exhibited. A new symmetrized sextic polynomial oscillator is introduced and
proved to be QES by explicitly deriving some exact, closed-form solutions by
resorting to the functional Bethe ansatz method. Such polynomial oscillators
include two categories of QES potentials: the first one containing the
well-known analytic sextic potentials as a subset, and the second one of novel
potentials with no counterpart in such a class.


title: QCD at high-luminosity hadron colliders

abstract:
  This talk gives a brief introduction to open questions in jet physics and QCD
which come to the fore in the high-luminosity regime characterizing the
upcoming phase of the Large Hadron Collider and future hadron colliders.


title:
Warm dark matter sterile neutrinos in electron capture and beta decay
  spectra

abstract:
  We briefly review the motivation to search for sterile neutrinos in the keV
mass scale, as dark matter candidates, and the prospects to find them in beta
decay or electron capture spectra, with a global perspective. We describe the
fundamentals of the neutrino flavor-mass eigenstate mismatch that opens the
possibility of detecting sterile neutrinos in such ordinary nuclear processes.
Results are shown and discussed for the effect of heavy neutrino emission in
electron capture in Holmium 163 and in two isotopes of Lead, 202 and 205, as
well as in the beta decay of Tritium. We study the de-excitation spectrum in
the considered cases of electron capture and the charged lepton spectrum in the
case of Tritium beta decay. For each of these cases, we define ratios of
integrated transition rates over different regions of the spectrum under study,
and give new results that may guide and facilitate the analysis of possible
future measurements, paying particular attention to forbidden transitions in
Lead isotopes.


title:
Analyzing new physics in the decays $\bar{B}^0 \to
  D^{(\ast)}\tau^-\bar\nu_{\tau}$ with form factors obtained from the covariant
  quark model

abstract:
  We study possible New Physics (NP) effects in the exclusive decays $\bar{B}^0
\to D^{(\ast)} \tau^- \bar{\nu}_{\tau}$. We extend the Standard Model (SM) by
taking into account right-handed vector (axial), left- and right-handed
(pseudo)scalar, and tensor current contributions. The $\bar{B}^0 \to
D^{(\ast)}$ transition form factors are calculated in the full kinematic $q^2$
range by employing a covariant quark model developed by us. We provide
constraints on NP operators based on measurements of the ratios of branching
fractions $R(D^{(\ast)}) \equiv \mathcal{B}(\bar{B}^0 \to D^{(\ast)} \tau^-
\bar{\nu}_{\tau})/ \mathcal{B}(\bar{B}^0 \to D^{(\ast)} \mu^- \bar{\nu}_{\mu})$
and consider the effects of these operators on physical observables in
different NP scenarios. We also derive the four-fold angular distribution for
the cascade decay $\bar {B}^0\to D^{\ast\,+}(\to D^0\pi^+)\tau^-\bar\nu_\tau$
which allows one to analyze the polarization of the $D^{\ast}$ meson in the
presence of NP effects. We discuss several strategies to distinguish between
various NP contributions.


title:
Distributional and regularized radiation fields of non-uniformly moving
  straight dislocations, and elastodynamic Tamm problem

abstract:
  This work introduces original explicit solutions for the elastic fields
radiated by non-uniformly moving, straight, screw or edge dislocations in an
isotropic medium, in the form of time-integral representations in which
acceleration-dependent contributions are explicitly separated out. These
solutions are obtained by applying an isotropic regularization procedure to
distributional expressions of the elastodynamic fields built on the Green
tensor of the Navier equation. The obtained regularized field expressions are
singularity-free, and depend on the dislocation density rather than on the
plastic eigenstrain. They cover non-uniform motion at arbitrary speeds,
including faster-than-wave ones. A numerical method of computation is
discussed, that rests on discretizing motion along an arbitrary path in the
plane transverse to the dislocation, into a succession of time intervals of
constant velocity vector over which time-integrated contributions can be
obtained in closed form. As a simple illustration, it is applied to the
elastodynamic equivalent of the Tamm problem, where fields induced by a
dislocation accelerated from rest beyond the longitudinal wave speed, and
thereafter put to rest again, are computed. As expected, the proposed
expressions produce Mach cones, the dynamic build-up and decay of which is
illustrated by means of full-field calculations.

categories: physics.class-ph cond-mat.mtrl-sci math-ph math.MP


title: Measurement-enhanced determination of BEC phase transitions

abstract:
  We demonstrate how dispersive atom number measurements during evaporative
cooling can be used for enhanced determination of the parameter dependence of
the transition to a Bose-Einstein condensate (BEC). In this way shot-to-shot
fluctuations in initial conditions are detected and the information extracted
per experimental realization is increased. We furthermore calibrate in-situ
images from dispersive probing of a BEC with corresponding absorption images in
time-of-flight. This allows for the determination of the transition point in a
single experimental realization by applying multiple dispersive measurements.
Finally, we explore the continuous probing of several consecutive phase
transition crossings using the periodic addition of a focused "dimple"
potential.


title: On the Coulomb interaction in superconducting pairing in cuprates

abstract:
  We discuss a reduction of superconducting transition temperature by the
intersite Coulomb repulsion for the d-wave pairing in cuprates. We compare the
results found for the spin-fermion model and the extended Hubbard model. We
argue that in both the models the d-wave superconducting transition temperature
is reduced by the Coulomb repulsion of holes in different unit cells. We also
show that in the strong correlation limit the s-wave superconductivity cannot
occur due to the kinematic restriction of no double occupancy in the Hubbard
subbands.


title: Inference of Haemoglobin Concentration From Stereo RGB

abstract:
  Multispectral imaging (MSI) can provide information about tissue oxygenation,
perfusion and potentially function during surgery. In this paper we present a
novel, near real-time technique for intrinsic measurements of total haemoglobin
(THb) and blood oxygenation (SO2) in tissue using only RGB images from a stereo
laparoscope. The high degree of spectral overlap between channels makes
inference of haemoglobin concentration challenging, non-linear and under
constrained. We decompose the problem into two constrained linear sub-problems
and show that with Tikhonov regularisation the estimation significantly
improves, giving robust estimation of the Thb. We demonstrate by using the
co-registered stereo image data from two cameras it is possible to get robust
SO2 estimation as well. Our method is closed from, providing computational
efficiency even with multiple cameras. The method we present requires only
spectral response calibration of each camera, without modification of existing
laparoscopic imaging hardware. We validate our technique on synthetic data from
Monte Carlo simulation % of light transport through soft tissue containing
submerged blood vessels and further, in vivo, on a multispectral porcine data
set.