title:
On deformations of multidimensional Poisson brackets of hydrodynamic
  type

abstract:
  The theory of Poisson Vertex Algebras (PVAs) is a good framework to treat
Hamiltonian partial differential equations. A PVA consists of a pair
$(\mathcal{A},\{\cdot_\lambda\cdot\})$ of a differential algebra $\mathcal{A}$
and a bilinear operation called the $\lambda$-bracket. We extend the definition
to the class of algebras $\mathcal{A}$ endowed with $d\geq1$ commuting
derivations. We call this structure a \emph{multidimensional PVA}: it is a
suitable setting to study Hamiltonian PDEs with $d$ spatial dimensions. We
apply this theory to the study of deformations of the Poisson brackets of
hydrodynamic type for $d=2$.


title:
The association between sunspot magnetic fields and superpenumbral
  fibrils

abstract:
  Spectropolarimetric observations of a sunspot were carried out with the
Tenerife Infrared Polarimeter at Observatorio del Teide, Tenerife, Spain. Maps
of the physical parameters were obtained from an inversion of the Stokes
profiles observed in the infrared Fe i line at 15648 angstrom. The regular
sunspot consisted of a light bridge which separated the two umbral cores of the
same polarity. One of the arms of the light bridge formed an extension of a
penumbral filament which comprised weak and highly inclined magnetic fields. In
addition, the Stokes V profiles in this filament had an opposite sign as the
sunspot and some resembled Stokes Q or U. This penumbral filament terminated
abruptly into another at the edge of the sunspot, where the latter was
relatively vertical by about 30 degrees. Chromospheric H-alpha and He 304
angstrom filtergrams revealed three superpenumbral fibrils on the limb-side of
the sunspot, in which one fibril extended into the sunspot and was oriented
along the highly inclined penumbral counterpart of the light bridge. An
intense, elongated brightening was observed along this fibril that was
co-spatial with the intersecting penumbral filaments in the photosphere. Our
results suggest that the disruption in the sunspot magnetic field at the
location of the light bridge could be the source of reconnection that led to
the intense chromospheric brightening and facilitated the supply of cool
material in maintaining the overlying superpenumbral fibrils.


title: Path coverings with prescribed ends in faulty hypercubes

abstract:
  We discuss the existence of vertex disjoint path coverings with prescribed
ends for the $n$-dimensional hypercube with or without deleted vertices.
Depending on the type of the set of deleted vertices and desired properties of
the path coverings we establish the minimal integer $m$ such that for every $n
\ge m$ such path coverings exist. Using some of these results, for $k \le 4$,
we prove Locke's conjecture that a hypercube with $k$ deleted vertices of each
parity is Hamiltonian if $n \ge k +2.$ Some of our lemmas substantially
generalize known results of I. Havel and T. Dvo\v{r}\'{a}k. At the end of the
paper we formulate some conjectures supported by our results.


title:
Systematic Physics Constrained Parameter Estimation of Stochastic
  Differential Equations

abstract:
  A systematic Bayesian framework is developed for physics constrained
parameter inference ofstochastic differential equations (SDE) from partial
observations. The physical constraints arederived for stochastic climate models
but are applicable for many fluid systems. A condition isderived for global
stability of stochastic climate models based on energy conservation.
Stochasticclimate models are globally stable when a quadratic form, which is
related to the cubic nonlinearoperator, is negative definite. A new algorithm
for the efficient sampling of such negative definite matrices is developed and
also for imputing unobserved data which improve the accuracy of theparameter
estimates. The performance of this framework is evaluated on two conceptual
climatemodels.


title: Shannon Sampling and Parseval Frames on Compact Manifolds

abstract:
  Our article is a summary of some results for Riemannian manifolds that were
obtained in \cite{gpes}-\cite{Pesssubm}. To the best of our knowledge these are
the pioneering papers which contain the most general results about frames,
Shannon sampling, and cubature formulas on compact and non-compact Riemannian
manifolds. In particular, the paper \cite{gpes} gives an "end point"
construction of tight localized frames on homogeneous compact manifolds. The
paper \cite{Pessubm} is the first systematic development of localized frames on
compact domains in Euclidean spaces.


title:
Model for tumour growth with treatment by continuous and pulsed
  chemotherapy

abstract:
  In this work we investigate a mathematical model describing tumour growth
under a treatment by chemotherapy that incorporates time-delay related to the
conversion from resting to hunting cells. We study the model using values for
the parameters according to experimental results and vary some parameters
relevant to the treatment of cancer. We find that our model exhibits a
dynamical behaviour associated with the suppression of cancer cells, when
either continuous or pulsed chemotherapy is applied according to clinical
protocols, for a large range of relevant parameters. When the chemotherapy is
successful, the predation coefficient of the chemotherapic agent acting on
cancer cells varies with the infusion rate of chemotherapy according to an
inverse relation. Finally, our model was able to reproduce the experimental
results obtained by Michor and collaborators [Nature, 435, 1267 (2005)] about
the exponential decline of cancer cells when patients are treated with the drug
glivec.


title: A new empirical metallicity calibration for Vilnius photometry

abstract:
  We present a new calibration of the seven-color Vilnius system in terms of
[Fe/H], applicable to F-M stars in the metallicity range -2.8<[Fe/H]<+0.5. We
employ a purely empirical approach, based on ~1000 calibrating stars with
high-resolution spectroscopic abundance determinations. It is shown that the
color index P-Y is the best choice for a most accurate and sensitive abundance
indicator for both dwarf and giant stars. Using it, [Fe/H] values can be
determined with an accuracy of $\pm$0.12 dex for stars of solar and mildly
sub-solar metallicity and $\pm$0.17 dex for stars with [Fe/H]<-1. The new
calibration is a significant improvement over the previous one used to date.


title:
Planning the electron traffic in semiconductor networks: A mesoscopic
  analog of the Braess paradox encountered in road networks

abstract:
  By combining quantum simulations of electron transport and scanning-gate
microscopy, we have shown that the current transmitted through a semiconductor
two-path rectangular network in the ballistic and coherent regimes of transport
can be paradoxically degraded by adding a third path to the network. This is
analogous to the Braess paradox occurring in classical networks. Simulations
reported here enlighten the role played by congestion in the network.


title: On the role of the chaotic velocity in relativistic kinetic theory

abstract:
  In this paper we revisit the concept of chaotic velocity within the context
of relativistic kinetic theory. Its importance as the key ingredient which
allows to clearly distinguish convective and dissipative effects is discussed
to some detail. Also, by addressing the case of the two component mixture, the
relevance of the barycentric comoving frame is established and thus the
convenience for the introduction of peculiar velocities for each species. The
fact that the decomposition of molecular velocity in systematic and peculiar
components does not alter the covariance of the theory is emphasized. Moreover,
we show that within an equivalent decomposition into space-like and time-like
tensors, based on a generalization of the relative velocity concept, the
Lorentz factor for the chaotic velocity can be expressed explicitly as an
invariant quantity. This idea, based on Ellis' theorem, allows to foresee a
natural generalization to the general relativistic case.


title: Constraints on the search space of argumentation

abstract:
  Drawing from research on computational models of argumentation (particularly
the Carneades Argumentation System), we explore the graphical representation of
arguments in a dispute; then, comparing two different traditions on the limits
of the justification of decisions, and devising an intermediate, semi-formal,
model, we also show that it can shed light on the theory of dispute resolution.
  We conclude our paper with an observation on the usefulness of highly
constrained reasoning for Online Dispute Resolution systems. Restricting the
search space of arguments exclusively to reasons proposed by the parties
(vetoing the introduction of new arguments by the human or artificial
arbitrator) is the only way to introduce some kind of decidability -- together
with foreseeability -- in the argumentation system.


title:
Quantum Optics With Single Nanodiamonds Flying Over Gold Films: Towards
  A Robust Quantum Plasmonics

abstract:
  A nanodiamond (ND) hosting nitrogen-vacancy (NV) color centers is attached on
the apex of an optical tip for near-field microscopy. Its fluorescence is used
to launch surface plasmon-polaritons (SPPs) in a thin polycrystalline gold
film. It is shown that the quantum nature of the initial source of light is
preserved after conversion to SPPs. This opens the way to a deterministic
quantum plasmonics, where single SPPs can be injected at well-defined positions
in a plasmonic device produced by top-down approaches.


title:
FELFCNCA: Fast & Efficient Log File Compression Using Non Linear
  Cellular Automata Classifier

abstract:
  Log Files are created for Traffic Analysis, Maintenance, Software debugging,
customer management at multiple places like System Services, User Monitoring
Applications, Network servers, database management systems which must be kept
for long periods of time. These Log files may grow to huge sizes in this
complex systems and environments. For storage and convenience log files must be
compressed. Most of the existing algorithms do not take temporal redundancy
specific Log Files into consideration. We propose a Non Linear based Classifier
which introduces a multidimensional log file compression scheme described in
eight variants, differing in complexity and attained compression ratios. The
FELFCNCA scheme introduces a transformation for log file whose compressible
output is far better than general purpose algorithms. This proposed method was
found lossless and fully automatic. It does not impose any constraint on the
size of log file


title:
Influence of hydrodynamic instabilities on the propagation mechanism of
  fast flames

abstract:
  The present work investigates the structure of fast supersonic turbulent
flames typically observed as precursors to the onset of detonation. These high
speed deflagrations are obtained after the interaction of a detonation wave
with cylindrical obstacles. Two mixtures having the same propensity for local
hot spot formation were considered, namely hydrogen-oxygen and methane-oxygen.
It was shown that the methane mixture sustained turbulent fast flames, while
the hydrogen mixture did not. Detailed high speed visualizations of nearly
two-dimensional flow fields permitted to identify the key mechanism involved.
The strong vorticity generation associated with shock reflections in methane
permitted to drive jets. These provided local enhancement of mixing rates,
sustenance of pressure waves, organization of the front in stronger fewer modes
and eventually the transition to detonation. In the hydrogen system, for
similar thermo-chemical parameters, the absence of these jets did not permit to
establish such fast flames. This jetting slip line instability in shock
reflections (and lack thereof in hydrogen) was correlated with the value of the
isentropic exponent and its control of Mach shock jetting instability (Mach &
Radulescu).


title:
Exploring the early dust-obscured phase of galaxy formation with blind
  mid-/far-IR spectroscopic surveys

abstract:
  While continuum imaging data at far-infrared to sub-millimeter wavelengths
have provided tight constraints on the population properties of dusty star
forming galaxies up to high redshifts, future space missions like the Space
Infra-Red Telescope for Cosmology and Astrophysics (SPICA) and ground based
facilities like the Cerro Chajnantor Atacama Telescope (CCAT) will allow
detailed investigations of their physical properties via their
mid-/far-infrared line emission. We present updated predictions for the number
counts and the redshift distributions of star forming galaxies
spectroscopically detectable by these future missions. These predictions
exploit a recent upgrade of evolutionary models, that include the effect of
strong gravitational lensing, in the light of the most recent Herschel and
South Pole Telescope data. Moreover the relations between line and continuum
infrared luminosity are re-assessed, considering also differences among source
populations, with the support of extensive simulations that take into account
dust obscuration. The derived line luminosity functions are found to be highly
sensitive to the spread of the line to continuum luminosity ratios. Estimates
of the expected numbers of detections per spectral line by SPICA/SAFARI and by
CCAT surveys for different integration times per field of view at fixed total
observing time are presented. Comparing with the earlier estimates by Spinoglio
et al. (2012) we find, in the case of SPICA/SAFARI, differences within a factor
of two in most cases, but occasionally much larger. More substantial
differences are found for CCAT.


title:
Theory of extreme correlations using canonical Fermions and path
  integrals

abstract:
  The t-J model is studied using a novel and rigorous mapping of the Gutzwiller
projected electrons, in terms of canonical electrons. The mapping has
considerable similarity to the Dyson-Maleev transformation relating spin
operators to canonical Bosons. This representation gives rise to a non
Hermitean quantum theory, characterized by minimal redundancies. A path
integral representation of the canonical theory is given. Using it, the salient
results of the extremely correlated Fermi liquid (ECFL) theory, including the
previously found Schwinger equations of motion, are easily rederived. Further a
transparent physical interpretation of the previously introduced auxiliary
Greens functions and the caparison factor is obtained.
  The low energy electron spectral function in this theory with a strong
intrinsic asymmetry, is summarized in terms of a few expansion coefficients.
These include an important emergent energy scale $\Delta_0$ that shrinks to
zero on approaching the insulating state, thereby making it difficult to access
the underlying low energy Fermi liquid behavior. The scaled low frequency ECFL
spectral function is related simply to the Fano line shape. The resulting
energy dispersion (EDC or MDC) is a hybrid of a massive and a massless Dirac
spectrum $ E^*_Q\sim \gamma\, Q- \sqrt{\Gamma_0^2 + Q^2} $, where the vanishing
of $Q$, a momentum like variable, locates the kink. Therefore the quasiparticle
velocity interpolates between $(\gamma \mp 1)$ over a width $\Gamma_0$ on the
two sides of $Q=0$. The resulting kink strongly resembles a prominent low
energy feature seen in angle resolved photoemission spectra (ARPES) of cuprate
materials. We also propose novel ways of analyzing the ARPES data to isolate
the predicted asymmetry between particle and hole excitations.


title: On the hyperbolic orbital counting problem in conjugacy classes

abstract:
  Given a discrete group $\Gamma$ of isometries of a negatively curved manifold
$\widetilde M$, a nontrivial conjugacy class $\mathfrak K$ in $\Gamma$ and
$x_0\in\widetilde M$, we give asymptotic counting results, as $t\to +\infty$,
on the number of orbit points $\gamma x_0$ at distance at most $t$ from $x_0$,
when $\gamma$ is restricted to be in $\mathfrak K$, as well as related
equidistribution results. These results generalise and extend work of Huber on
cocompact hyperbolic lattices in dimension $2$. We also study the growth of
given conjugacy classes in finitely generated groups endowed with a word
metric.


title:
A reversible mesoscopic model of diffusion in liquids: from giant
  fluctuations to Fick's law

abstract:
  We study diffusive mixing in the presence of thermal fluctuations under the
assumption of large Schmidt number. In this regime we obtain a limiting
equation that contains a diffusive thermal drift term with diffusion
coefficient obeying a Stokes-Einstein relation, in addition to the expected
advection by a random velocity. The overdamped limit correctly reproduces both
the enhanced diffusion in the ensemble-averaged mean and the long-range
correlated giant fluctuations in individual realizations of the mixing process,
and is amenable to efficient numerical solution. Through a combination of
Eulerian and Lagrangian numerical methods we demonstrate that diffusion in
liquids is not most fundamentally described by Fick's irreversible law; rather,
diffusion is better modeled as reversible random advection by thermal velocity
fluctuations. We find that the diffusion coefficient is effectively
renormalized to a value that depends on the scale of observation. Our work
reveals somewhat unexpected connections between flows at small scales,
dominated by thermal fluctuations, and flows at large scales, dominated by
turbulent fluctuations.


title:
Efficient Metropolis-Hastings Proposal Mechanisms for Bayesian
  Regression Tree Models

abstract:
  Bayesian regression trees are flexible non-parametric models that are well
suited to many modern statistical regression problems. Many such tree models
have been proposed, from the simple single- tree model to more complex tree
ensembles. Their non-parametric formulation allows for effective and efficient
modeling of datasets exhibiting complex non-linear relationships between the
model pre- dictors and observations. However, the mixing behavior of the Markov
Chain Monte Carlo (MCMC) sampler is sometimes poor. This is because the
proposals in the sampler are typically local alterations of the tree structure,
such as the birth/death of leaf nodes, which does not allow for efficient
traversal of the model space. This poor mixing can lead to inferential
problems, such as under-representing uncertainty. In this paper, we develop
novel proposal mechanisms for efficient sampling. The first is a rule
perturbation proposal while the second we call tree rotation. The perturbation
proposal can be seen as an efficient variation of the change proposal found in
existing literature. The novel tree rotation proposal is simple to implement as
it only requires local changes to the regression tree structure, yet it
efficiently traverses disparate regions of the model space along contours of
equal probability. When combined with the classical birth/death proposal, the
resulting MCMC sampler exhibits good acceptance rates and properly represents
model uncertainty in the posterior samples. We implement this sampling
algorithm in the Bayesian Additive Regression Tree (BART) model and demonstrate
its effectiveness on a prediction problem from computer experiments and a test
function where structural tree variability is needed to fully explore the
posterior.


title:
Serre duality and H\"ormander's solution of the $\bar \partial $
  -equation

abstract:
  We use duality in the manner of Serre to generalize a theorem of Hedenmalm on
solution of the $\bar \partial $ equation with inverse of the weight in
H\"ormander $\displaystyle L^{2}$ estimates.\


title: Bootstrapped Grouping of Results to Ambiguous Person Name Queries

abstract:
  Some of the main ranking features of today's search engines reflect result
popularity and are based on ranking models, such as PageRank, implicit feedback
aggregation, and more. While such features yield satisfactory results for a
wide range of queries, they aggravate the problem of search for ambiguous
entities: Searching for a person yields satisfactory results only if the person
we are looking for is represented by a high-ranked Web page and all required
information are contained in this page. Otherwise, the user has to either
reformulate/refine the query or manually inspect low-ranked results to find the
person in question. A possible approach to solve this problem is to cluster the
results, so that each cluster represents one of the persons occurring in the
answer set. However clustering search results has proven to be a difficult
endeavor by itself, where the clusters are typically of moderate quality.
  A wealth of useful information about persons occurs in Web 2.0 platforms,
such as LinkedIn, Wikipedia, Facebook, etc. Being human-generated, the
information on these platforms is clean, focused, and already disambiguated. We
show that when searching for ambiguous person names the information from such
platforms can be bootstrapped to group the results according to the individuals
occurring in them. We have evaluated our methods on a hand-labeled dataset of
around 5,000 Web pages retrieved from Google queries on 50 ambiguous person
names.


title:
Cosmologically probing ultra-light particle dark matter using 21 cm
  signals

abstract:
  There can arise ubiquitous ultra-light scalar fields in the Universe, such as
the pseudo-Goldstone bosons from the spontaneous breaking of an approximate
symmetry, which can make a partial contribution to the dark matter and affect
the large scale structure of the Universe. While the properties of those
ultra-light dark matter are heavily model dependent and can vary in a wide
range, we develop a model-independent analysis to forecast the constraints on
their mass and abundance using futuristic but realistic 21 cm observables as
well as CMB fluctuations, including CMB lensing measurements. Avoiding the
highly nonlinear regime, the 21 cm emission line spectra are most sensitive to
the ultra-light dark matter with mass m ~10^{-26} eV for which the precision
attainable on mass and abundance bounds can be of order of a few percent.


title: Protostar mass functions in young clusters

abstract:
  In an improved model of protostar mass functions (PMFs), protostars gain mass
from isothermal cores in turbulent clumps. Their mass accretion rate is similar
to Shu accretion at low mass, and to reduced Bondi accretion at high mass.
Accretion durations follow a simple expression in which higher-mass protostars
accrete for longer times. These times are set by ejections, stellar feedback,
and gravitational competition, which terminate accretion and reduce its
efficiency. The mass scale is the mass of a critically stable isothermal core.
In steady state, the PMF approaches a power law at high mass due to competition
between clump accretion and accretion stopping. The power law exponent is the
ratio of the time scales of accretion and accretion stopping. The luminosity
function (PLF) peaks near 1 L_Sun, due to inefficient accretion of core gas.
Models fit observed PLFs in four large embedded clusters. These indicate that
their underlying PMFs may be top-heavy compared to the IMF, depending on the
model of protostar radius.


title: High-dimensional change-point detection with sparse alternatives

abstract:
  We consider the problem of detecting a change in mean in a sequence of
Gaussian vectors. Under the alternative hypothesis, the change occurs only in
some subset of the components of the vector. We propose a test of the presence
of a change-point that is adaptive to the number of changing components. Under
the assumption that the vector dimension tends to infinity and the length of
the sequence grows slower than the dimension of the signal, we obtain the
detection boundary for this problem and prove its rate-optimality.


title: Spectral Bounds for Polydiagonal Jacobi Matrix Operators

abstract:
  The research on spectral inequalities for discrete Schrodinger Operators has
proved fruitful in the last decade. Indeed, several authors analysed the
operator's canonical relation to a tridiagonal Jacobi matrix operator. In this
paper, we consider a generalisation of this relation with regards to connecting
higher order Schrodinger-type operators with symmetric matrix operators with
arbitrarily many non-zero diagonals above and below the main diagonal. We thus
obtain spectral bounds for such matrices, similar in nature to the
Lieb{Thirring inequalities.


title:
Relativistic two-particle equations with superposition of delta-shell
  potentials: scattering and bound states

abstract:
  Exact solutions of two-particle relativistic equations of quantum field
theory describing the scattering $s$-states and the bound $s$-states are found
in the cases of delta-shell potential and superposition of delta-shell
potentials. Some properties of obtained relativistic wave functions, scattering
amplitudes and quantization conditions are investigated. The resonance
character of scattering processes is demonstrated by the behavior of
amplitudes. It is shown that the non-relativistic limits of these relativistic
values coincide with respective non-relativistic ones obtained from the
Schr\"{o}dinger equation.


title:
A sequential reduction method for inference in generalized linear mixed
  models

abstract:
  The likelihood for the parameters of a generalized linear mixed model
involves an integral which may be of very high dimension. Because of this
intractability, many approximations to the likelihood have been proposed, but
all can fail when the model is sparse, in that there is only a small amount of
information available on each random effect. The sequential reduction method
described in this paper exploits the dependence structure of the posterior
distribution of the random effects to reduce substantially the cost of finding
an accurate approximation to the likelihood in models with sparse structure.


title:
The PageRank Problem, Multi-Agent Consensus and Web Aggregation -- A
  Systems and Control Viewpoint

abstract:
  PageRank is an algorithm introduced in 1998 and used by the Google Internet
search engine. It assigns a numerical value to each element of a set of
hyperlinked documents (that is, web pages) within the World Wide Web with the
purpose of measuring the relative importance of the page. The key idea in the
algorithm is to give a higher PageRank value to web pages which are visited
often by web surfers. On its website, Google describes PageRank as follows:
``PageRank reflects our view of the importance of web pages by considering more
than 500 million variables and 2 billion terms. Pages that are considered
important receive a higher PageRank and are more likely to appear at the top of
the search results." Today PageRank is a paradigmatic problem of great interest
in various areas, such as information technology, bibliometrics, biology, and
e-commerce, where objects are often ranked in order of importance. This article
considers a distributed randomized approach based on techniques from the area
of Markov chains using a graph representation consisting of nodes and links. We
also outline connections with other problems of current interest to the systems
and control community, which include ranking of control journals, consensus of
multi-agent systems, and aggregation-based techniques.


title: Molecules in the Circumnuclear Disk of the Galactic Center

abstract:
  Within a few parsecs around the central Black Hole Sgr A*, chemistry in the
dense molecular cloud material of the circumnuclear disk (CND) can be affected
by many energetic phenomena such as high UV-flux from the massive central star
cluster, X-rays from Sgr A*, shock waves, and an enhanced cosmic-ray flux.
Recently, spectroscopic surveys with the IRAM 30 meter and the APEX 12 meter
telescopes of substantial parts of the 80--500 GHz frequency range were made
toward selected positions in and near the CND. These datasets contain lines
from the molecules HCN, HCO$^+$, HNC, CS, SO, SiO, CN, H$_2$CO, HC$_3$N,
N$_2$H$^+$, H$_3$O$^+$ and others. We conduct Large Velocity Gradient analyses
to obtain column densities and total hydrogen densities, $n$, for each species
in molecular clouds located in the southwest lobe of CND. The data for the
above mentioned molecules indicate 10$^5\,$cm$^{-3} \lesssim n
<10^6\,$cm$^{-3}$, which shows that the CND is tidally unstable. The derived
chemical composition is compared with a chemical model calculated using the
UCL\_CHEM code that includes gas and grain reactions, and the effects of shock
waves. Models are run for varying shock velocities, cosmic-ray ionization
rates, and number densities. The resulting chemical composition is fitted best
to an extremely high value of cosmic-ray ionization rate $\zeta \sim
10^{-14}\,$s$^{-1}$, 3 orders of magnitude higher than the value in regular
Galactic molecular clouds, if the pre-shock density is $n=10^5\,$cm$^{-3}$.


title: The smoothing of $m$-subharmonic functions

abstract:
  We prove Richberg type theorem for $m$-subharmonic function. The main tool is
the complex Hessian equation for which we obtain the existence of the unique
smooth solution in strictly pseudoconvex domains.


title: New Constants in Discrete Lieb-Thirring Inequalities for Jacobi Matrices

abstract:
  This paper is essentially derived from the observation that some results used
for improving constants in the Lieb-Thirring inequalities for Schrodinger
operators in L2(-\infty,\infty) can be translated to the discrete Schrodinger
op- erators and more generally to Jacobi matrices. Some results were previ-
ously proved by D. Hundertmark and B. Simon and the aim of this article is to
improve the constants obtained in their article [7].


title: Optical Properties of Relativistic Plasma Mirrors

abstract:
  The advent of ultrahigh-power femtosecond lasers creates a need for optical
components suitable to handle ultrahigh light intensities. Due to the
unavoidable laser-induced ionization of matter, these components will have to
be based on a plasma medium. An archetype of such optical elements is a plasma
mirror, created when an intense femtosecond laser pulse impinges on a solid
target. It consists of a dense plasma, formed by the laser field itself, which
specularly reflects the main part of the pulse. Plasma mirrors have major
potential applications as active optical elements to manipulate the temporal
and spatial properties of intense laser beams, in particular for the generation
of intense attosecond pulses of light. We investigate the basic physics
involved in the deformation of a plasma mirror resulting from the light
pressure exerted by the ultraintense laser during reflection, by deriving a
simple model of this fundamental process, which we validate both numerically
and experimentally. The understanding of this deformation is essential for all
future applications of plasma mirrors, especially for the generation of
collimated attosecond beams. We show how its effect on the attosecond beam
divergence can be mitigated by using the laser phase, thus providing crucial
control for future applications in attosecond science.


title: From Maxout to Channel-Out: Encoding Information on Sparse Pathways

abstract:
  Motivated by an important insight from neural science, we propose a new
framework for understanding the success of the recently proposed "maxout"
networks. The framework is based on encoding information on sparse pathways and
recognizing the correct pathway at inference time. Elaborating further on this
insight, we propose a novel deep network architecture, called "channel-out"
network, which takes a much better advantage of sparse pathway encoding. In
channel-out networks, pathways are not only formed a posteriori, but they are
also actively selected according to the inference outputs from the lower
layers. From a mathematical perspective, channel-out networks can represent a
wider class of piece-wise continuous functions, thereby endowing the network
with more expressive power than that of maxout networks. We test our
channel-out networks on several well-known image classification benchmarks,
setting new state-of-the-art performance on CIFAR-100 and STL-10, which
represent some of the "harder" image classification benchmarks.


title:
Super-high-efficiency approximate calculation of series sum and discrete
  Fourier transform

abstract:
  We present a super-high-efficiency approximate computing scheme for series
sum and discrete Fourier transform. The summation of a series sum or a discrete
Fourier transform is approximated by summing over part of the terms multiplied
by corresponding weights. The calculation is valid for the function under the
transform being piecewise smooth in the continuum variable. The scheme reduces
significantly the requirement for computer memory storage and enhances the
numerical computation efficiency without losing accuracy. By comparing with the
known results of examples, we show the accuracy and the efficiency of the
scheme. The efficiency can be higher than $10^6$ for the examples.


title:
Stepping and crowding of molecular motors: statistical kinetics from an
  exclusion process perspective

abstract:
  Motor enzymes are remarkable molecular machines that use the energy derived
from the hydrolysis of a nucleoside triphosphate to generate mechanical
movement, achieved through different steps that constitute their kinetic cycle.
These macromolecules, nowadays investigated with advanced experimental
techniques to unveil their molecular mechanisms and the properties of their
kinetic cycles, are implicated in many biological processes, ranging from
biopolymerisation (e.g. RNA polymerases and ribosomes) to intracellular
transport (motor proteins such as kinesins or dyneins). Although the kinetics
of individual motors is well studied on both theoretical and experimental
grounds, the repercussions of their stepping cycle on the collective dynamics
still remains unclear. Advances in this direction will improve our
comprehension of transport process in the natural intracellular medium, where
processive motor enzymes might operate in crowded conditions. In this work, we
therefore extend the current statistical kinetic analysis to study collective
transport phenomena of motors in terms of lattice gas models belonging to the
exclusion process class. Via numerical simulations, we show how to interpret
and use the randomness calculated from single particle trajectories in crowded
conditions. Importantly, we also show that time fluctuations and non-Poissonian
behavior are intrinsically related to spatial correlations and the emergence of
large, but finite, clusters of co-moving motors. The properties unveiled by our
analysis have important biological implications on the collective transport
characteristics of processive motor enzymes in crowded conditions.


title: On the superradiance-tidal friction correspondence

abstract:
  Since the work of Hartle in the 1970s, and the subsequent development of the
the Membrane Paradigm approach to black hole physics it has been widely
accepted that superradiant scattering of gravitational waves bears strong
similarities with the phenomenon of ``tidal friction'' (well-known from
Newtonian gravity) operating in binary systems of viscous material bodies. In
this paper we revisit the superradiance-tidal friction analogy within the
context of ultracompact relativistic bodies. We advocate that as long as these
bodies have non-zero viscosity they should undergo tidal friction that can be
construed as a kind of superradiant scattering from the point of view of the
dynamics of an orbiting test-body. In addition we consider the presence of
anisotropic matter, which is required for at least some ultracompact bodies, if
they are to sustain a radius very close to the gravitational radius. We find
that the tidal friction/superradiance output is enhanced with increasing
anisotropy and that strongly anisotropic systems exhibit an unconventional
response to tidal and centrifugal forces. Finally, we make contact with the
artificial system comprising a black hole with its horizon replaced by a mirror
(sometimes used as a proxy for ultracompact material bodies) and discuss
superradiance and tidal friction in relation to it.


title:
Adapting Binary Information Retrieval Evaluation Metrics for
  Segment-based Retrieval Tasks

abstract:
  This report describes metrics for the evaluation of the effectiveness of
segment-based retrieval based on existing binary information retrieval metrics.
This metrics are described in the context of a task for the hyperlinking of
video segments. This evaluation approach re-uses existing evaluation measures
from the standard Cranfield evaluation paradigm. Our adaptation approach can in
principle be used with any kind of effectiveness measure that uses binary
relevance, and for other segment-baed retrieval tasks. In our video
hyperlinking setting, we use precision at a cut-off rank n and mean average
precision.


title:
Landau gauge gluon and ghost propagators from two-flavor lattice QCD at
  T > 0

abstract:
  In this contribution we extend our unquenched computation of the Landau gauge
gluon and ghost propagators in lattice QCD at non-zero temperature. The study
was aimed at providing input for investigations employing continuum functional
methods. We show data which correspond to pion mass values between 300 and 500
MeV and are obtained for a lattice size 32**3 x 12. The longitudinal and
transversal components of the gluon propagator turn out to change smoothly
through the crossover region, while the ghost propagator exhibits only a very
weak temperature dependence. For a pion mass of around 400 MeV and the
intermediate temperature value of approx. 240 MeV we compare our results with
additional data obtained on a lattice with smaller Euclidean time extent N_t =
8, 10 and find a reasonable scaling behavior.


title: Long-Lived Distributed Relative Localization of Robot Swarms

abstract:
  This paper studies the problem of having mobile robots in a multi-robot
system maintain an estimate of the relative position and relative orientation
of near-by robots in the environment. This problem is studied in the context of
large swarms of simple robots which are capable of measuring only the distance
to near-by robots.
  We present two distributed localization algorithms with different trade-offs
between their computational complexity and their coordination requirements. The
first algorithm does not require the robots to coordinate their motion. It
relies on a non-linear least squares based strategy to allow robots to compute
the relative pose of near-by robots. The second algorithm borrows tools from
distributed computing theory to coordinate which robots must remain stationary
and which robots are allowed to move. This coordination allows the robots to
use standard trilateration techniques to compute the relative pose of near-by
robots. Both algorithms are analyzed theoretically and validated through
simulations.


title: All Weather Calibration of Wide Field Optical and NIR Surveys

abstract:
  The science goals for ground-based large-area surveys, such as the Dark
Energy Survey, Pan-STARRS, and the Large Synoptic Survey Telescope, require
calibration of broadband photometry that is stable in time and uniform over the
sky to precisions of a per cent or better. This performance will need to be
achieved with data taken over the course of many years, and often in less than
ideal conditions. This paper describes a strategy to achieve precise internal
calibration of imaging survey data taken in less than photometric conditions,
and reports results of an observational study of the techniques needed to
implement this strategy. We find that images of celestial fields used in this
case study with stellar densities of order one per arcmin-squared and taken
through cloudless skies can be calibrated with relative precision of 0.5 per
cent (reproducibility). We report measurements of spatial structure functions
of cloud absorption observed over a range of atmospheric conditions, and find
it possible to achieve photometric measurements that are reproducible to 1 per
cent in images that were taken through cloud layers that transmit as little as
25 per cent of the incident optical flux (1.5 magnitudes of extinction). We
find, however, that photometric precision below 1 per cent is impeded by the
thinnest detectable cloud layers. We comment on implications of these results
for the observing strategies of future surveys.


title: On truncation of irreducible representations of Chevalley groups II

abstract:
  We determine the growth of the dimension of the slope subspaces of the
cohomology of arithmetic subgroups in reductive algebraic groups as a function
of the slope.


title: Cut-Set Bounds for Networks with Zero-Delay Nodes

abstract:
  In a network, a node is said to incur a delay if its encoding of each
transmitted symbol involves only its received symbols obtained before the time
slot in which the transmitted symbol is sent (hence the transmitted symbol sent
in a time slot cannot depend on the received symbol obtained in the same time
slot). A node is said to incur no delay if its received symbol obtained in a
time slot is available for encoding its transmitted symbol sent in the same
time slot. Under the classical model, every node in a discrete memoryless
network (DMN) incurs a unit delay, and the capacity region of the DMN satisfies
the well-known cut-set outer bound. In this paper, we propose a generalized
model for the DMN where some nodes may incur no delay. Under our generalized
model, we obtain a new cut-set outer bound, which is proved to be tight for
some two-node DMN and is shown to subsume an existing cut-set bound for the
causal relay network. In addition, we establish under the generalized model
another cut-set outer bound on the positive-delay region -- the set of
achievable rate tuples under the constraint that every node incurs a delay. We
use the cut-set bound on the positive-delay region to show that for some
two-node DMN under the generalized model, the positive-delay region is strictly
smaller than the capacity region.


title:
Moufang semidirect products of loops with groups and inverse property
  extensions

abstract:
  We investigate Moufang loops which can be written as the semidirect product
of a loop and a group. We also examine a particular class of loop extensions
which arise as a result of a finite cyclic group acting as a group of
semiautomorphisms on an inverse property loop. A question posed by Gagola III
related to such extensions is partially answered, and we give several examples
which illustrate that, in general, these extensions are not well-behaved.


title: HarborNet: A Real-World Testbed for Vehicular Networks

abstract:
  We present a real-world testbed for research and development in vehicular
networking that has been deployed successfully in the sea port of Leix\~oes in
Portugal. The testbed allows for cloud-based code deployment, remote network
control and distributed data collection from moving container trucks, cranes,
tow boats, patrol vessels and roadside units, thereby enabling a wide range of
experiments and performance analyses. After describing the testbed architecture
and its various modes of operation, we give concrete examples of its use and
offer insights on how to build effective testbeds for wireless networking with
moving vehicles.


title:
Ab initio simulations of hydrogen-bonded ferroelectrics: collective
  tunneling and the origin of geometrical isotope effects

abstract:
  Ab initio simulations that account for nuclear quantum effects have been used
to examine the order-disorder transition in squaric acid, a prototypical
H-bonded antiferroelectric crystal. Our simulations reproduce the >100 K
difference in transition temperature observed upon deuteration as well as the
strong geometrical isotope effect observed on intermolecular separations within
the crystal. We find that collective transfer of protons along the H-bonding
chains - facilitated by quantum mechanical tunneling - is critical to the
order-disorder transition and the geometrical isotope effect. This sheds light
on the origin of isotope effects and the importance of tunneling in squaric
acid which likely extends to other H-bonded ferroelectrics.


title:
An Interpretation of Flare-Induced and Decayless Coronal-Loop
  Oscillations as Interference Patterns

abstract:
  We present an alternative model of coronal-loop oscillations which considers
that the waves are trapped in a 2D waveguide formed by the entire arcade of
field lines. This differs from the standard 1D model which treats the waves as
the resonant oscillations of just the visible bundle of field lines. Within the
framework of our 2D model, the two types of oscillations that have been
observationally identified, flare-induced waves and "decayless" oscillations,
can both be attributed to MHD fast waves. The two components of the signal
differ only because of the duration and spatial extent of the source that
creates them. The flare-induced waves are generated by strong localized sources
of short duration, while the decayless background can be excited by a
continuous, stochastic source. Further, the oscillatory signal arising from a
localized, short-duration source can be interpreted as a pattern of
interference fringes produced by waves that have traveled diverse routes of
various pathlengths through the waveguide. The resulting amplitude of the
fringes slowly decays in time with an inverse square root dependence. The
details of the interference pattern depend on the shape of the arcade and the
spatial variation of the Alfv\'en speed. The rapid decay of this wave
component, which has previously been attributed to physical damping mechanisms
that remove energy from resonant oscillations, occurs as a natural consequence
of the interference process without the need for local dissipation.


title: (A)symmetries of weak decays at and near the kinematic endpoint

abstract:
  At the kinematic endpoint of zero recoil physical momenta are parallel which
leads to symmetries in the decay distributions. We implement this observation
for decays of the type $A \to (B_1 B_2) C$ by extending the helicity formalism
to include an unphysical timelike polarisation. The symmetries of the helicity
amplitudes are worked out for a generic dimension six Hamiltonian for a $B \to
V \ell \ell$ decay type. We obtain \emph{exact} predictions for angular
observables, e.g.,for the fraction of longitudinally polarized vector mesons,
$F_L = 1/3$, which may be used to guide experimental analyses. We investigate
the vicinity of the endpoint through an expansion in the three momentum of the
vector meson. New physics can be searched for in the slope of the observables
near the endpoint. Current experimental data on $B \to K^* \ell \ell$ decays
are found to be in agreement with our predictions within uncertainties.
Application to other semileptonic $B$ and $D$ decays, including $B \to V \ell^+
\ell^-$, $V=K^*,\phi, \rho$ and $B \to V \ell \nu$, $V=\rho,D^*$ is
straightforward. For hadronic modes of the types $B \to V p \bar p, V \Lambda
\bar \Lambda, ..$ and $B \to V \pi \pi, V \pi K, .. $ endpoint relations apply
as long as they are not overwhelmed by sizeable final state interactions
between the $V$ and the hadron pair.


title:
Electronic Hong-Ou-Mandel interferometry in two-dimensional topological
  insulators

abstract:
  The edge states of a two-dimensional topological insulator are characterized
by their helicity, a very remarkable property which is related to the
time-reversal symmetry and the topology of the underlying system. We
theoretically investigate a Hong-Ou-Mandel like setup as a tool to probe it.
Collisions of two electrons with the same spin show a Pauli dip, analogous to
the one obtained in the integer quantum Hall case. Moreover, the collisions
between electrons of opposite spin also lead to a dip, known as
$\mathbb{Z}_{2}$ dip, which is a direct consequence of the constraints imposed
by time-reversal symmetry. In contrast to the integer quantum Hall case, the
visibility of these dips is reduced by the presence of the additional edge
channels, and crucially depends on the properties of the quantum point contact.
As a unique feature of this system, we show the possibility of three-electron
interference, which leads to a total suppression of the noise independently of
the point contact configuration. This is assured by the peculiar interplay
between Fermi statistics and topology. This work intends to extend the domain
of applicability of electron quantum optics.


title: Vacuum Stability Bounds On Higgs Mass With Gravitational Contributions

abstract:
  We calculate the gravitational contributions to $\phi^4$ theory with general
$R_\xi$ gauge-fixing choice and find that the result is gauge independent.
Based on weak coupling expansion of gravity and ignoring the possible higher
dimensional operators from "integrating out" the impact of gravity, we study
the impacts of gravitational effects on vacuum stability. New contributions to
the beta function of scalar quartic coupling $\la$ by gravitational effects can
modify the RGE running of $\la$ near the Planck scale. Numerical calculations
show that the lower bound of higgs mass requiring absolutely vacuum stability
can be relaxed for almost 0.6 to 0.8 GeV depending on the choice of top quark
mass.


title:
Quantized Thermal Conductance of Nanowires at Room Temperature due to
  Surface Phonon-Polaritons

abstract:
  Based on the Landauer formalism, we demonstrate that the thermal conductance
due to the propagation of surface phonon-polaritons along a polar nanowire is
independent of the material characteristics and is given by Pi^2kB^2T/3h. The
giant propagation length of these energy carriers establishes that this
quantization holds not only for a temperature much smaller than 1 K, as is the
case of electrons and phonons, but also for temperatures comparable to room
temperature, which can significantly facilitate its observation and application
in the thermal management of nanoscale electronics and photonics.


title:
New inversion, convolution and Titchmarsh's theorems for the
  half-Hilbert transform

abstract:
  While exploiting the generalized Parseval equality for the Mellin transform,
we derive the reciprocal inverse operator in the weighted L_2-space related to
the Hilbert transform on the nonnegative half-axis. Moreover, employing the
convolution method, which is based on the Mellin-Barnes integrals, we prove the
corresponding convolution and Titchmarsh's theorems for the half-Hilbert
transform. Some applications to the solvability of a new class of singular
integral equations are demonstrated. Our technique does not require the use of
methods of the Riemann-Hilbert boundary value problems for analytic functions.
The same approach will be applied in the forthcoming research to invert the
half-Hartley transform and to establish its convolution theorem.


title:
Dynamic electrophysical characterization of rubidium polytungstate
  ceramics under fast humidity impact

abstract:
  The electrophysical reaction of rubidium polytungstate Rb4W11O35 ceramics
(RPTC) on fast humidity impact has been investigated by studying the influence
of wet air pulse of 1-3 s of duration on the peculiarities of dynamic
current-voltage (I-V-) and charge-voltage (Q-V-) loops and transient
current-time (I-t-) curves. The revealed peculiarities of I-V- and Q-V-loops
and I-t-curves for RPTC subjected to humidity impact were compared with similar
ones observed for water damaged hydrogen-bounded ferroelectric triglicyne
sulphate (TGS) crystals. The obtained data indicate at least two possible
scenarios of polar reaction on the humidity impact, namely protonic/ionic space
charge transfer and ferroelectric-like reversible polarization in surface
conglomerate of RPTC disturbed by dipolar H2O adsorbate. Due to a high surface
activity the RPTC can be considered as promising materials for creating
humidity sensitive elements of environment monitoring systems. Direct
humidity-to-frequency (time) conversion was realized by inserting
metal-RPTC-metal humidity sensitive element in LC resonance or RC-relaxation
frequency control circuits of generating units.


title:
Simple expressions for second order density perturbations in standard
  cosmology

abstract:
  In this paper we present four simple expressions for the relativistic first
and second order fractional density perturbations for $\Lambda$CDM cosmologies
in different gauges: the Poisson, uniform curvature, total matter and
synchronous gauges. A distinctive feature of our approach is the use of a
canonical set of quadratic differential expressions involving an arbitrary
spatial function, the so-called comoving curvature perturbation, to describe
the spatial dependence, which enables us to unify, simplify and extend previous
seemingly disparate results. The simple structure of the expressions makes the
evolution of the density perturbations completely transparent and clearly
displays the effect of the cosmological constant on the dynamics, namely that
it stabilizes the perturbations. We expect that the results will be useful in
applications, for example, studying the effects of primordial non-Gaussianity
on the large scale structure of the universe.


title: Zeros of the weight two Eisenstein Series

abstract:
  We develop some of the finer details of the location of the zeros of the
weight two Eisenstein series. These zeros are the same as the zeros of the
derivative of the Ramanujan delta function.


title:
Multi-frame denoising of high speed optical coherence tomography data
  using inter-frame and intra-frame priors

abstract:
  Optical coherence tomography (OCT) is an important interferometric diagnostic
technique which provides cross-sectional views of the subsurface microstructure
of biological tissues. However, the imaging quality of high-speed OCT is
limited due to the large speckle noise. To address this problem, this paper
proposes a multi-frame algorithmic method to denoise OCT volume.
Mathematically, we build an optimization model which forces the temporally
registered frames to be low rank, and the gradient in each frame to be sparse,
under logarithmic image formation and noise variance constraints. Besides, a
convex optimization algorithm based on the augmented Lagrangian method is
derived to solve the above model. The results reveal that our approach
outperforms the other methods in terms of both speckle noise suppression and
crucial detail preservation.


title:
Kinetic and potential components of the exact time-dependent correlation
  potential

abstract:
  The exact exchange-correlation (xc) potential of time-dependent density
functional theory has been shown to have striking features. For example, step
and peak features are generically found when the system is far from its
ground-state, and these depend nonlocally on the density in space and time. We
analyze the xc potential by decomposing it into kinetic and interaction
potential components, and comparing each with their exact-adiabatic
counterparts, for a range of dynamical situations in model one-dimensional (1D)
two-electron systems. We find that often, but not always, the kinetic contri-
bution is mostly responsible for these features, that are missed by the
adiabatic approximation. The adiabatic approximation often makes a smaller
error for the potential contribution, which we write in two parts, one being
the Coulomb potential due to the time-dependent xc hole. These observations
also held in non-equilibrium cases we studied where there are large features in
the correlation po- tential although no step structure. In ground-state
situations, step and peak structures arise in cases of static correlation, when
more than one determinant is essential to describe the interacting state. We
investigate the time-dependent natural orbital occupation numbers and find the
corresponding relation between these and the dynamical step is more complex
than for the ground-state case.


title:
Bifurcation structures and transient chaos in a four-dimensional Chua
  model

abstract:
  A four-dimensional four-parameter Chua model with cubic nonlinearity is
studied applying numerical continuation and numerical solutions methods.
Regarding numerical solution methods, its dynamics is characterized on Lyapunov
and isoperiodic diagrams and regarding numerical continuation method, the
bifurcation curves are obtained. Combining both methods the bifurcation
structures of the model were obtained with the possibility to describe the {\it
shrimp}-shaped domains and their endoskeletons. We study the effect of a
parameter that controls the dimension of the system leading the model to
present transient chaos with its corresponding basin of attraction being
riddled.


title: Twist spinning of knots and metabolizers of Blanchfield pairings

abstract:
  In a classic paper Zeeman introduced the k-twist spin of a knot K and showed
that the exterior of a twist spin fibers over S^1. In particular this result
shows that the knot K # -K is doubly slice. In this paper we give a quick proof
of Zeeman's result. The k-twist spin of K also gives rise to two metabolizers
for K # -K and we determine these two metabolizers precisely.


title:
Light sfermion interplay in the 125 GeV MSSM Higgs production and decay
  at the LHC

abstract:
  We study the effects from light sfermions on the lightest Higgs boson
production and decay at the Large Hadron Collider (LHC) within the Minimal
Supersymmetric Standard Model (MSSM). We find that the scenario with light
coloured sfermions -- stops or sbottoms -- has the potential to explain a
non-universal alteration, as hinted by LHC data, of the gluon-gluon Fusion
($\mu_{ggF}$) with respect to the Vector Boson Fusion ($\mu_{VBF}$) event rates
and, in particular, can predict $\frac{\mu_{VBF}}{\mu_{ggF}}>1$ for all Higgs
boson decay channels in large areas of the parameter space.
  We also find that the scenario with a light stop/sbottom can be complemented
by the scenario in which the total Higgs width, $\Gamma_{\rm tot}$, is reduced
due to a suppressed Yukawa coupling $Y_b$. In this case, the reduction of the
Higgs production rates in the $ggF$ process which occurs in the maximal mixing
scenario is compensated by the reduction of the $H\to b\bar{b}$ partial decay
width, the largest component of $\Gamma_{\rm tot}$.
  Furthermore, we highlight the fact that, in the light stop/sbottom scenario,
event rates with the Higgs boson decaying to a $b\bar{b}$ final state are
predicted to be essentially below unity. Therefore, during the future LHC runs,
the measurement of $h\to b\bar{b}$ final states is a matter of special
importance.
  Amongst all viable MSSM configurations that we study (including revisiting a
light stau solution), we emphasise most the scenario with a light stop, as the
latter is also motivated by Dark Matter and Electro-Weak baryogenesis. We also
perform fits of the MSSM against the LHC data, emphasising the fact that in
most cases these are better than for the SM.


title:
The Schneiderman-Teichner invariant applied to immersions arising from
  link maps in $S^4$

abstract:
  It is shown that Schneiderman and Teichner's invariant $\tau$ detects the
example due to Kirk of a link map $f:S^2_+\cup S^2_-\to S^4$ for which the
restricted map $f|S^2_+:S^2_+\to S^4-f(S^2_-)$ has vanishing Wall
self-intersection but is not homotopic to an embedding.


title:
Interacting photon-baryon fluid, warm dark matter and the first acoustic
  peak

abstract:
  The Reduced Relativistic Gas (RRG) model was introduced by A. Sakharov in
1965 for deriving the cosmic microwave background (CMB) spectrum. It was
recently reinvented by some of us to achieve an interpolation between the
radiation and dust epochs in the evolution of the Universe. This model
circumvents the complicated structure of the Boltzmann-Einstein system of
equations and admits a transparent description of warm-dark-matter effects. It
is extended here to include, on a phenomenological basis, an out-of-equilibrium
interaction between radiation and baryons which is supposed to account for
relevant aspects of pre-recombination physics in a simplified manner.
Furthermore, we use the tight-coupling approximation to explore the influence
of both this interaction and of the RRG warmness parameter on the anisotropy
spectrum of the CMB. The predictions of the model are very similar to those of
the {\Lambda}CDM model if both the interaction and the dark-matter warmness
parameters are of the order of $10^{-4}$ or smaller. As far as the warmness
parameter is concerned, this is in good agreement with previous estimations on
the basis of results from structure formation.


title: Projective stochastic equations and nonlinear long memory

abstract:
  A projective moving average $\{X_t, t \in \mathbb{Z}\}$ is a Bernoulli shift
written as a backward martingale transform of the innovation sequence. We
introduce a new class of nonlinear stochastic equations for projective moving
averages, termed projective equations, involving a (nonlinear) kernel $Q$ and a
linear combination of projections of $X_t$ on "intermediate" lagged innovation
subspaces with given coefficients $\alpha_i, \beta_{i,j}$. The class of such
equations include usual moving-average processes and the Volterra series of the
LARCH model. Solvability of projective equations is studied, including a nested
Volterra series representation of the solution $X_t$. We show that under
natural conditions on $Q, \alpha_i, \beta_{i,j}$, this solution exhibits
covariance and distributional long memory, with fractional Brownian motion as
the limit of the corresponding partial sums process.


title: On Gumbel limit for the length of reactive paths

abstract:
  We give a new proof of the vanishing noise limit theorem for exit times of
1-dimensional diffusions conditioned on exiting through a point separated from
the starting point by a potential wall. We also prove a scaling limit for exit
location in a model 2-dimensional situation.


title: Testing randomness with photons

abstract:
  Generating and characterising randomness is fundamentally important in both
classical and quantum information science. Here we report the experimental
demonstration of ensembles of pseudorandom optical processes comprising what
are known as t-designs. We show that in practical scenarios, certain finite
ensembles of two-mode transformations---1- and 2-designs---are
indistinguishable from truly random operations for 1- and 2-photon quantum
interference, but they fail to mimic randomness for 2- and 3-photon cases,
respectively. This provides a novel optical test of pseudo randomness. We make
use of the fact that t-photon behaviour is governed by degree-2t polynomials in
the parameters of the optical process to experimentally verify the ensembles'
behaviour for complete bases of polynomials. This ensures that outputs will be
uniform for arbitrary configurations, satisfying the strict definition of
pseudorandomness implicit in the mathematical definition.


title: Discrete second order constrained Lagrangian systems: first results

abstract:
  We briefly review the notion of second order constrained (continuous) system
(SOCS) and then propose a discrete time counterpart of it, which we naturally
call discrete second order constrained system (DSOCS). To illustrate and test
numerically our model, we construct certain integrators that simulate the
evolution of two mechanical systems: a particle moving in the plane with
prescribed signed curvature, and the inertia wheel pendulum with a Lyapunov
constraint. In addition, we prove a local existence and uniqueness result for
trajectories of DSOCSs. As a first comparison of the underlying geometric
structures, we study the symplectic behavior of both SOCSs and DSOCSs.


title:
Zeeman splitting of light hole in quantum wells: comparison of theory
  and experiments

abstract:
  The theory for light-hole Zeeman splitting developed in [Physica E 44, 797
(2012)] is compared with experimental data found in literature for GaAs/AlGaAs,
InGaAs/InP and CdTe/CdMgTe quantum wells. It is shown that the description of
experiments is possible with account for excitonic effects and peculiarities of
the hole energy spectrum in a quantum well including complex structure of the
valence band and the interface mixing of light and heavy holes. It is
demonstrated that the absolute values and the sign of the light-hole $g$-factor
are extremely sensitive to the parametrization of the Luttinger Hamiltonian.


title:
Weak harmonic Maass forms of weight 5/2 and a mock modular form for the
  partition function

abstract:
  We construct a natural basis for the space of weak harmonic Maass forms of
weight 5/2 on the full modular group. The non-holomorphic part of the first
element of this basis encodes the values of the ordinary partition function
p(n). We obtain a formula for the coefficients of the mock modular forms of
weight 5/2 in terms of regularized inner products of weakly holomorphic modular
forms of weight -1/2, and we obtain Hecke-type relations among these mock
modular forms.


title: Short-range force between two Higgs bosons

abstract:
  The $S$-wave scattering length and the effective range of the Higgs boson in
Standard Model are studied using effective-field-theory approach. After
incorporating the first-order electroweak correction, the short-range force
between two Higgs bosons remains weakly attractive for $M_H=126$ GeV. It is
interesting to find that the force range is about two order-of-magnitude larger
than the Compton wavelength of the Higgs boson, almost comparable with the
typical length scale of the strong interaction.


title:
Manifestation of a spin-splitting field in a thermally-biased Josephson
  junction

abstract:
  We investigate the behavior of a Josephson junction consisting of a
ferromagnetic insulator-superconductor (FI-S) bilayer tunnel-coupled to a
superconducting electrode. We show that the Josephson coupling in the structure
is strenghtened by the presence of the spin-splitting field induced in the FI-S
bilayer. Such strenghtening manifests itself as an increase of the critical
current $I_c$ with the amplitude of the exchange field. Furthermore, the effect
can be strongly enhanced if the junction is taken out of equilibrium by a
temperature bias. We propose a realistic setup to assess experimentally the
magnitude of the induced exchange field, and predict a drastic deviation of the
$I_c(T)$ curve ($T$ is the temperature) with respect to equilibrium.


title: Locality of percolation for abelian Cayley graphs

abstract:
  We prove that the value of the critical probability for percolation on an
abelian Cayley graph is determined by its local structure. This is a partial
positive answer to a conjecture of Schramm: the function pc defined on the set
of Cayley graphs of abelian groups of rank at least 2 is continuous for the
Benjamini-Schramm topology. The proof involves group-theoretic tools and a new
block argument.


title: Thermal escape from extrasolar giant planets

abstract:
  The detection of hot atomic hydrogen and heavy atoms and ions at high
altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b
imply that these planets have hot and rapidly escaping atmospheres that extend
to several planetary radii. These characteristics, however, cannot be
generalized to all close-in EGPs. The thermal escape mechanism and mass loss
rate from EGPs depend on a complex interplay between photochemistry and
radiative transfer driven by the stellar UV radiation. In this work we explore
how these processes change under different levels of irradiation on giant
planets with different characteristics. We confirm that there are two distinct
regimes of thermal escape from EGPs, and that the transition between these
regimes is relatively sharp. Our results have implications on thermal mass loss
rates from different EGPs that we discuss in the context of currently known
planets and the detectability of their upper atmospheres.


title: Scale-Free Percolation in Continuum Space

abstract:
  The study of real-life network modeling has become very popular in recent
years. An attractive model is the scale-free percolation model on the lattice
$\mathbb{Z}^d$, $d\ge1$, because it fulfills several stylized facts observed in
large real-life networks. We adopt this model to continuum space which leads to
a heterogeneous random-connection model on $\mathbb{R}^d$: particles are
generated by a homogeneous marked Poisson point process on $\mathbb{R}^d$, and
the probability of an edge between two particles is determined by their marks
and their distance. In this model we study several properties such as the
degree distributions, percolation properties and graph distances.


title: Critical behaviour in the QCD Anderson transition

abstract:
  We study the Anderson-type localisation-delocalisation transition found
previously in the QCD Dirac spectrum at high temperature. Using high statistics
QCD simulations with $N_f=2+1$ flavours of staggered quarks, we discuss how the
change in the spectral statistics depends on the volume, the temperature and
the lattice spacing, and we speculate on the possible universality of the
transition from Poisson to Wigner-Dyson in the spectral statistics. Moreover,
we show that the transition is a genuine phase transition: at the mobility
edge, separating localised and delocalised modes, quantities characterising the
spectral statistics become non-analytic in the thermodynamic limit. Using
finite size scaling we also determine the critical exponent of the correlation
length, and we speculate on possible extensions of the universality of Anderson
transitions.


title:
Multiplicity of Galactic Cepheids from long-baseline interferometry. II.
  The Companion of AX Circini revealed with VLTI/PIONIER

abstract:
  Aims: We aim at detecting and characterizing the main-sequence companion of
the Cepheid AX Cir ($P_\mathrm{orb} \sim $ 18 yrs). The long-term objective is
to estimate the mass of both components and the distance to the system.
Methods: We used the PIONIER combiner at the VLT Interferometer to obtain the
first interferometric measurements of the short-period Cepheid AX Cir and its
orbiting component. Results: The companion is resolved by PIONIER at a
projected separation $\rho = 29.2 \pm 0.2$ mas and projection angle $PA = 167.6
\pm 0.3^{\circ}$. We measured $H$-band flux ratios between the companion and
the Cepheid of $0.90 \pm 0.10$ % and $0.75 \pm 0.17$ %, respectively at a
pulsation phase for the Cepheid $\phi = 0.24$ and 0.48. The lower contrast at
$\phi = 0.48$ is due to increased brightness of the Cepheid compared to the
$\phi = 0.24$. This gives an average apparent magnitude $m\mathrm{_H (comp)} =
9.06 \pm 0.24$ mag. The limb-darkened angular diameter of the Cepheid at the
two pulsation phases was measured to be $\theta_\mathrm{LD} = 0.839 \pm 0.023$
mas and $\theta_\mathrm{LD} = 0.742 \pm 0.020$ mas, respectively at $\phi =
0.24$ and 0.48. A lower limit on the total mass of the system was also derived
based on our measured separation, we found $M_\mathrm{T} \geq 9.7 \pm 0.6
M_\odot$.


title:
Forbidden Minors For 3-Connected Graphs With No Non-Splitting
  5-Configurations

abstract:
  For a set of five edges, a graph splits if one of the associated Dodgson
polynomials is equal to zero. A graph G splitting for every set of five edges
is a minor-closed property. As such there is a finite set of forbidden minors F
such that if a graph H does not contain a minor isomorphic to any graph in F,
then H splits. In this paper we prove that if a graph G is simple, 3-connected,
and splits, then G must not contain any minors isomorphic to K5, K3,3, the
octahedron, the cube, or a graph that is a single delta-Y transformation away
from the cube. As such this is the set of all simple 3-connected forbidden
minors. The complete set of 2-connected or non-simple forbidden minors remains
unresolved, though a number have been found.


title:
Finding high-order analytic post-Newtonian parameters from a
  high-precision numerical self-force calculation

abstract:
  We present a novel analytic extraction of high-order post-Newtonian (pN)
parameters that govern quasi-circular binary systems. Coefficients in the pN
expansion of the energy of a binary system can be found from corresponding
coefficients in an extreme-mass-ratio inspiral (EMRI) computation of the change
$\Delta U$ in the redshift factor of a circular orbit at fixed angular
velocity. Remarkably, by computing this essentially gauge-invariant quantity to
accuracy greater than one part in $10^{225}$, and by assuming that a subset of
pN coefficients are rational numbers or products of $\pi$ and a rational, we
obtain the exact analytic coefficients. We find the previously unexpected
result that the post-Newtonian expansion of $\Delta U$ (and of the change
$\Delta\Omega$ in the angular velocity at fixed redshift factor) have
conservative terms at half-integral pN order beginning with a 5.5 pN term. This
implies the existence of a corresponding 5.5 pN term in the expansion of the
energy of a binary system.
  Coefficients in the pN series that do not belong to the subset just described
are obtained to accuracy better than 1 part in $10^{265-23n}$ at $n$th pN
order. We work in a radiation gauge, finding the radiative part of the metric
perturbation from the gauge-invariant Weyl scalar $\psi_0$ via a Hertz
potential. We use mode-sum renormalization, and find high-order renormalization
coefficients by matching a series in $L=\ell+1/2$ to the large-$L$ behavior of
the expression for $\Delta U$. The non-radiative parts of the perturbed metric
associated with changes in mass and angular momentum are calculated in the
Schwarzschild gauge.


title:
Conditions for building a community of practice in an advanced physics
  laboratory

abstract:
  In this paper we explore the theory of communities of practice in the context
of a physics college course and in particular the classroom environment of an
advanced laboratory. We introduce the idea of elements of a classroom community
being able to provide students with the opportunity to have an accelerated
trajectory towards being a more central participant of the community of
practice of physicists. This opportunity is a result of structural features of
the course and a primary instructional choice which result in the development
of a learning community with several elements that encourage students to engage
in more authentic practices of a physicist. A jump in accountable disciplinary
knowledge is also explored as a motivation for enculturation into the community
of practice of physicists. In the advanced laboratory what students are being
assessed on as counting as physics is significantly different and so they need
to assimilate in order to succeed.


title: Efficient basis for the Dicke Model I: theory and convergence in energy

abstract:
  An extended bosonic coherent basis has been shown by Chen to provide
numerically exact solutions of the finite-size Dicke model. The advantages in
employing this basis, as compared with the photon number (Fock) basis, are
exhibited to be valid for a large region of the Hamiltonian parameter space by
analyzing the converged values of the ground state energy.


title: Optimal Provision-After-Wait in Healthcare

abstract:
  We investigate computational and mechanism design aspects of scarce resource
allocation, where the primary rationing mechanism is through waiting times.
Specifically we consider allocating medical treatments to a population of
patients. Each patient needs exactly one treatment, and can choose from $k$
hospitals. Hospitals have different costs, which are fully paid by a third
party ---the "payer". The payer has a fixed budget $B$, and each hospital will
have its own waiting time. At equilibrium, each patient will choose his most
preferred hospital given his intrinsic preferences and the waiting times. The
payer thus computes the waiting times so that at equilibrium the budget
constraint is satisfied and the social welfare is maximized.
  We first show that the optimization problem is NP-hard, yet if the budget can
be relaxed to $(1+\epsilon)B$ for an arbitrarily small $\epsilon$, then the
optimum under budget $B$ can be approximated efficiently. Next, we study the
endogenous emergence of waiting time from the dynamics between hospitals and
patients, and show that there is no need for the payer to explicitly enforce
the optimal waiting times. Under certain conditions, all he need is to enforce
the amount of money he wants to pay to each hospital. The dynamics will always
converge to the desired waiting times in finite time.
  We then go beyond equilibrium solutions and investigate the optimization
problem over a much larger class of mechanisms containing the equilibrium ones
as special cases. With two hospitals, we show that under a natural assumption
on the patients' preference profiles, optimal welfare is in fact attained by
the randomized assignment mechanism, which allocates patients to hospitals at
random subject to the budget constraint, but avoids waiting times.
  Finally, we discuss potential policy implications of our results, as well as
follow-up directions and open problems.


title:
Search for a multi-Higgs-boson cascade in WWbb events with the ATLAS
  detector in pp collisions at sqrt(s) = 8 TeV

abstract:
  A search is presented for new particles in an extension to the Standard Model
that includes a heavy Higgs boson H0, an intermediate charged Higgs boson pair
H+-, and a light Higgs boson h0. The analysis searches for events involving the
production of a single heavy neutral Higgs boson which decays to the charged
Higgs boson and a W boson, where the charged Higgs boson subsequently decays
into a W boson and the lightest neutral Higgs boson decaying to a
bottom--antibottom-quark pair. Such a cascade results in a W-boson pair and a
bottom--antibottom-quark pair in the final state. Events with exactly one
lepton, missing transverse momentum, and at least four jets are selected from a
data sample corresponding to an integrated luminosity of 20.3/fb, collected by
the ATLAS detector in proton--proton collisions at sort(s)=8 TeV at the LHC.
The data are found to be consistent with Standard Model predictions, and 95%
confidence-level upper limits are set on the product of cross section and
branching ratio. These limits range from 0.065 pb to 43 pb as a function of H0
and H+- masses, with m(h0) fixed at 125 GeV.


title:
Uplink Interference Analysis for Two-tier Cellular Networks with Diverse
  Users under Random Spatial Patterns

abstract:
  Multi-tier architecture improves the spatial reuse of radio spectrum in
cellular networks, but it introduces complicated heterogeneity in the spatial
distribution of transmitters, which brings new challenges in interference
analysis. In this work, we present a stochastic geometric model to evaluate the
uplink interference in a two-tier network considering multi-type users and base
stations. Each type of tier-1 users and tier-2 base stations are modeled as
independent homogeneous Poisson point processes, and tier-2 users are modeled
as locally non-homogeneous clustered Poisson point processes centered at tier-2
base stations. By applying a superposition-aggregation-superposition approach,
we quantify the interference at both tiers. Our model is also able to capture
the impact of two types of exclusion regions, where either tier-2 base stations
or tier-2 users are restricted in order to avoid cross-tier interference. As an
important application of this analytical model, an intensity planning scenario
is investigated, in which we aim to maximize the total income of the network
operator with respect to the intensities of tier-2 cells, under constraints on
the outage probabilities of tier-1 and tier-2 users. The result of our
interference analysis suggests that this maximization can be converted to a
standard convex optimization problem. Finally, numerical studies further
demonstrate the correctness of our analysis.


title:
Efficient basis for the Dicke Model II: wave function convergence and
  excited states

abstract:
  An extended bosonic coherent basis has been shown by Chen et al to provide
numerically exact solutions of the finite-size Dicke model. The advantages in
employing this basis, as compared with the photon number (Fock) basis, are
exhibited to be valid for a large region of the Hamiltonian parameter space and
many excited states by analyzing the convergence in the wave functions.


title: Antineutrino reactor safeguards - a case study

abstract:
  Antineutrinos have been proposed as a means of reactor safeguards for more
than 30 years and there has been impressive experimental progress in neutrino
detection. In this paper we conduct, for the first time, a case study of the
application of antineutrino safeguards to a real-world scenario - the North
Korean nuclear crisis in 1994. We derive detection limits to a partial or full
core discharge in 1989 based on actual IAEA safeguards access and find that two
independent methods would have yielded positive evidence for a second core with
very high confidence. To generalize our results, we provide detailed estimates
for the sensitivity to the plutonium content of various types of reactors,
including most types of plutonium production reactors, based on detailed
reactor simulations. A key finding of this study is that a wide class of
reactors with a thermal power of less than 0.1-1 GWth can be safeguarded
achieving IAEA goals for quantitative sensitivity and timeliness with detectors
right outside the reactor building. This type of safeguards does not rely on
the continuity of knowledge and provides information about core inventory and
power status in real-time.


title: A generalization of Lazard's elimination theorem

abstract:
  Using the classical Lazard's elimination theorem, we obtain a decomposition
theorem for Lie algebras defined by generators and relations of a certain type.
This is a preprint version of the paper appearing in Communications in Algebra
Volume 32, Issue 10, 2004.


title:
A Distributed Algorithm for Constructing a Minimum Diameter Spanning
  Tree

abstract:
  We present a new algorithm, which solves the problem of distributively
finding a minimum diameter spanning tree of any (non-negatively) real-weighted
graph $G = (V,E,\omega)$. As an intermediate step, we use a new, fast,
linear-time all-pairs shortest paths distributed algorithm to find an absolute
center of $G$. The resulting distributed algorithm is asynchronous, it works
for named asynchronous arbitrary networks and achieves $\mathcal{O}(|V|)$ time
complexity and $\mathcal{O}\left(|V|\,|E|\right)$


title:
Optical response of highly excited particles in a strongly correlated
  system

abstract:
  We present a linear-response formalism for a system of correlated electrons
out of equilibrium, as relevant for the probe optical absorption in pump-probe
experiments. We consider the time dependent optical conductivity
$\sigma(\omega,t)$ and its nonequilibrium properties. As an application we
numerically study a single highly excited charged particle in the spin
background, as described within the two-dimensional $t$-$J$ model. Our results
show that the optical sum rule approaches the equilibrium-like one very fast,
however, the time evolution and the final asymptotic behavior of the absorption
spectra in the finite systems considered still reveal dependence on the type of
initial pump perturbation. This is observed in the evolution of its main
features: the mid-infrared peak and the Drude weight.


title: Fidelity, susceptibility and critical exponents in the Dicke model

abstract:
  We calculate numerically the fidelity and its susceptibility for the ground
state of the Dicke model. A minimum in the fidelity identifies the critical
value of the interaction where a quantum phase crossover, the precursor of a
phase transition for finite number of atoms N, takes place. The evolution of
these observables is studied as a function of N, and their critical exponents
evaluated. Using the critical exponents the universal curve for the specific
susceptibility is recovered. An estimate to the precision to which the ground
state wave function is numerically calculated is given, and found to have its
lowest value, for a fixed truncation, in a vicinity of the critical coupling.


title: Stability of periodic waves in Hamiltonian PDEs

abstract:
  Partial differential equations endowed with a Hamiltonian structure, like the
Korteweg--de Vries equation and many other more or less classical models, are
known to admit rich families of periodic travelling waves. The stability theory
for these waves is still in its infancy though. The issue has been tackled by
various means. Of course, it is always possible to address stability from the
spectral point of view. However, the link with nonlinear stability -in fact,
\emph{orbital} stability, since we are dealing with space-invariant problems-,
is far from being straightforward when the best spectral stability we can
expect is a \emph{neutral} one. Indeed, because of the Hamiltonian structure,
the spectrum of the linearized equations cannot be bounded away from the
imaginary axis, even if we manage to deal with the point zero, which is always
present because of space invariance. Some other means make a crucial use of the
underlying structure. This is clearly the case for the variational approach,
which basically uses the Hamiltonian -or more precisely, a constrained
functional associated with the Hamiltonian and with other conserved quantities-
as a Lyapunov function. When it works, it is very powerful, since it gives a
straight path to orbital stability. An alternative is the modulational
approach, following the ideas developed by Whitham almost fifty years ago. The
main purpose here is to point out a few results, for KdV-like equations and
systems, that make the connection between these three approaches: spectral,
variational, and modulational.


title:
Kahler metric on the space of convex real projective structures on
  surface

abstract:
  We prove that the space of convex real projective structures on a surface of
genus $g\ge 2$ admits a mapping class group invariant
  K\"ahler metric where Teichm\"uller space with Weil-Petersson metric is a
totally geodesic complex submanifold.


title:
Generalised Geometrical CP Violation in a $T^{\prime}$ Lepton Flavour
  Model

abstract:
  We analyse the interplay of generalised CP transformations and the
non-Abelian discrete group $T^{\prime}$ and use the semi-direct product $G_f=
T^{\prime}\rtimes H_{\text{CP}}$, as family symmetry acting in the lepton
sector. The family symmetry is shown to be spontaneously broken in a
geometrical manner. In the resulting flavour model, naturally small Majorana
neutrino masses for the light active neutrinos are obtained through the type I
see-saw mechanism. The known masses of the charged leptons, lepton mixing
angles and the two neutrino mass squared differences are reproduced by the
model with a good accuracy. The model allows for two neutrino mass spectra with
normal ordering (NO) and one with inverted ordering (IO). For each of the three
spectra the absolute scale of neutrino masses is predicted with relatively
small uncertainty. The value of the Dirac CP violation (CPV) phase $\delta$ in
the lepton mixing matrix is predicted to be $\delta \cong \pi/2~{\rm or}~
3\pi/2$. Thus, the CP violating effects in neutrino oscillations are predicted
to be maximal (given the values of the neutrino mixing angles) and
experimentally observable. We present also predictions for the sum of the
neutrino masses, for the Majorana CPV phases and for the effective Majorana
mass in neutrinoless double beta decay. The predictions of the model can be
tested in a variety of ongoing and future planned neutrino experiments.


title:
Calibrated configurations for Frenkel-Kontorova type models in
  almost-periodic environments

abstract:
  The Frenkel-Kontorova model describes how an infinite chain of atoms
minimizes the total energy of the system when the energy takes into account the
interaction of nearest neighbors as well as the interaction with an exterior
environment. An almost-periodic environment leads to consider a family of
interaction energies which is stationary with respect to a minimal topological
dynamical system. We introduce, in this context, the notion of calibrated
configuration (stronger than the standard minimizing condition) and, for
continuous superlinear interaction energies, we show the existence of these
configurations for some environment of the dynamical system. Furthermore, in
one dimension, we give sufficient conditions on the family of interaction
energies to ensure, for any environment, the existence of calibrated
configurations when the underlying dynamics is uniquely ergodic. The main
mathematical tools for this study are developed in the frameworks of discrete
weak KAM theory, Aubry-Mather theory and spaces of Delone sets


title:
Koppe's Work of 1948: A fundamental for non-equilibrium rate of particle
  production

abstract:
  In 1948, Koppe formulated an almost complete recipe for statistical-thermal
models including particle production, formation and decay of resonances,
temporal and thermal evolution of the interacting system, statistical
approaches and equilibrium condition in final state of the nuclear interaction.
As the rate of particle production was one of the basic assumptions, recalling
Koppe's work would be an essential input to be involved in the statistical
prediction of non-equilibrium particle production in recent and future
ultra-relativistic collisions.


title: PSN: Portfolio Social Network

abstract:
  In this paper we present a web-based information system which is a portfolio
social network (PSN) that provides solutions to recruiters and job seekers. The
proposed system enables users to create portfolios so that he/she can add his
specializations with piece of code, if any, specifically for software
engineers, which is accessible online. The unique feature of the system is to
enable the recruiters to quickly view the prominent skills of the users. A
comparative analysis of the proposed system with the state of the art systems
is presented. The comparative study reveals that the proposed system has
advanced functionalities.


title:
An Algorithmic Theory of Dependent Regularizers, Part 1: Submodular
  Structure

abstract:
  We present an exploration of the rich theoretical connections between several
classes of regularized models, network flows, and recent results in submodular
function theory. This work unifies key aspects of these problems under a common
theory, leading to novel methods for working with several important models of
interest in statistics, machine learning and computer vision.
  In Part 1, we review the concepts of network flows and submodular function
optimization theory foundational to our results. We then examine the
connections between network flows and the minimum-norm algorithm from
submodular optimization, extending and improving several current results. This
leads to a concise representation of the structure of a large class of pairwise
regularized models important in machine learning, statistics and computer
vision.
  In Part 2, we describe the full regularization path of a class of penalized
regression problems with dependent variables that includes the graph-guided
LASSO and total variation constrained models. This description also motivates a
practical algorithm. This allows us to efficiently find the regularization path
of the discretized version of TV penalized models. Ultimately, our new
algorithms scale up to high-dimensional problems with millions of variables.


title: Modeling Suspicious Email Detection using Enhanced Feature Selection

abstract:
  The paper presents a suspicious email detection model which incorporates
enhanced feature selection. In the paper we proposed the use of feature
selection strategies along with classification technique for terrorists email
detection. The presented model focuses on the evaluation of machine learning
algorithms such as decision tree (ID3), logistic regression, Na\"ive Bayes
(NB), and Support Vector Machine (SVM) for detecting emails containing
suspicious content. In the literature, various algorithms achieved good
accuracy for the desired task. However, the results achieved by those
algorithms can be further improved by using appropriate feature selection
mechanisms. We have identified the use of a specific feature selection scheme
that improves the performance of the existing algorithms.


title: Quantum Chaos in Ultracold Collisions of Erbium

abstract:
  Atomic and molecular samples reduced to temperatures below 1 microkelvin, yet
still in the gas phase, afford unprecedented energy resolution in probing and
manipulating how their constituent particles interact with one another. For
simple atoms, such as alkalis, scattering resonances are extremely
well-characterized. However, ultracold physics is now poised to enter a new
regime, where far more complex species can be cooled and studied, including
magnetic lanthanide atoms and even molecules. For molecules, it has been
speculated that a dense forest of resonances in ultracold collision cross
sections will likely express essentially random fluctuations, much as the
observed energy spectra of nuclear scattering do. According to the
Bohigas-Giannoni-Schmit conjecture, these fluctuations would imply chaotic
dynamics of the underlying classical motion driving the collision. This would
provide a paradigm shift in ultracold atomic and molecular physics,
necessitating new ways of looking at the fundamental interactions of atoms in
this regime, as well as perhaps new chaos-driven states of ultracold matter. In
this report we provide the first experimental demonstration that random spectra
are indeed found at ultralow temperatures. In the experiment, an ultracold gas
of erbium atoms is shown to exhibit many Fano-Feshbach resonances, for bosons
on the order of 3 per gauss. Analysis of their statistics verifies that their
distribution of nearest-neighbor spacings is what one would expect from random
matrix theory. The density and statistics of these resonances are explained by
fully-quantum mechanical scattering calculations that locate their origin in
the anisotropy of the atoms' potential energy surface. Our results therefore
reveal for the first time chaotic behavior in the native interaction between
ultracold atoms.


title:
Not Always Sparse: Flooding Time in Partially Connected Mobile Ad Hoc
  Networks

abstract:
  In this paper we study mobile ad hoc wireless networks using the notion of
evolving connectivity graphs. In such systems, the connectivity changes over
time due to the intermittent contacts of mobile terminals. In particular, we
are interested in studying the expected flooding time when full connectivity
cannot be ensured at each point in time. Even in this case, due to finite
contact times durations, connected components may appear in the connectivity
graph. Hence, this represents the intermediate case between extreme cases of
fully mobile ad hoc networks and fully static ad hoc networks. By using a
generalization of edge-Markovian graphs, we extend the existing models based on
sparse scenarios to this intermediate case and calculate the expected flooding
time. We also propose bounds that have reduced computational complexity.
Finally, numerical results validate our models.


title: Analytical models of X-shape magnetic fields in galactic halos

abstract:
  External spiral galaxies seen edge-on exhibit X-shape magnetic fields in
their halos. Whether the halo of our own Galaxy also hosts an X-shape magnetic
field is still an open question. We would like to provide the necessary
analytical tools to test the hypothesis of an X-shape magnetic field in the
Galactic halo. We propose a general method to derive analytical models of
divergence-free magnetic fields whose field lines are assigned a specific
shape. We then utilize our method to obtain four particular models of X-shape
magnetic fields in galactic halos. In passing, we also derive two particular
models of predominantly horizontal magnetic fields in galactic disks. All our
field models have spiraling field lines with spatially varying pitch angle. Our
four halo field models do indeed lead to X patterns in synthetic synchrotron
polarization maps. Their precise topologies can all be explained by the action
of a wind blowing outward from the galactic disk or from the galactic center.
In practice, our field models may be used for fitting purposes or as inputs to
various theoretical problems.


title:
Orbit Approach to Separation of Variables in sl(3)-Related Integrable
  Systems

abstract:
  Using the orbit method we attempt to reveal geometric and algebraic meaning
of separation of variables for the integrable systems on coadjoint orbits in an
$\mathfrak{sl}(3)$ loop algebra. We consider two types of generic orbits
embedded into a common manifold, endowed with two nonsingular Lie-Poisson
brackets. We prove that separation of variables on orbits of both types is
realized by the same variables of separation. We also construct the integrable
systems on these orbits: a coupled 3-component nonlinear Schr\"{o}dinger
equation and an isotropic SU(3) Landau-Lifshitz equation.


title:
Characterization of the gradient blow-up of the solution to the
  conductivity equation in the presence of adjacent circular inclusions

abstract:
  We consider the conductivity problem in the presence of adjacent circular
inclusions having arbitrary constant conductivity. When two inclusions get
closer and their conductivities degenerate to zero or infinity, the gradient of
the solution can be arbitrary large. We characterize the gradient blow-up by
deriving an explicit formula for the singular term of the solution in terms of
the Lerch transcendent function. This derivation is valid for inclusions having
arbitrary constant conductivity. We illustrate our results with numerical
calculations.


title: Few-hole double quantum dot in an undoped GaAs/AlGaAs heterostructure

abstract:
  We demonstrate a hole double quantum dot in an undoped GaAs/AlGaAs
heterostructure. The interdot coupling can be tuned over a wide range, from
formation of a large single dot to two well-isolated quantum dots. Using charge
sensing, we show the ability to completely empty the dot of holes and control
the charge occupation in the few-hole regime. The device should allow for
control of individual hole spins in single and double quantum dots in GaAs.