title: The Kaon Bag Parameter at Physical Mass

abstract:
  We present preliminary results for the calculation of the Kaon Bag parameter
$B_K$ in $N_f=2+1$ lattice QCD, using M\"obius Domain Wall Fermion ensembles
generated by the RBC-UKQCD collaboration. This computation is done directly at
physical meson masses, so that we do not have to rely on chiral perturbation
theory or any other mass extrapolation. In parallel, the four-quark operator is
renormalised through the Rome-Southampton technique. Finally, we compare our
value with previous results and draw some conclusions about the remaining
dominant contributions in our error budget.


title:
Novel text categorization by amalgamation of augmented k-nearest
  neighborhood classification and k-medoids clustering

abstract:
  Machine learning for text classification is the underpinning of document
cataloging, news filtering, document steering and exemplification. In text
mining realm, effective feature selection is significant to make the learning
task more accurate and competent. One of the traditional lazy text classifier
k-Nearest Neighborhood (kNN) has a major pitfall in calculating the similarity
between all the objects in training and testing sets, there by leads to
exaggeration of both computational complexity of the algorithm and massive
consumption of main memory. To diminish these shortcomings in viewpoint of a
data-mining practitioner an amalgamative technique is proposed in this paper
using a novel restructured version of kNN called AugmentedkNN(AkNN) and
k-Medoids(kMdd) clustering.The proposed work comprises preprocesses on the
initial training set by imposing attribute feature selection for reduction of
high dimensionality, also it detects and excludes the high-fliers samples in
the initial training set and restructures a constrictedtraining set. The kMdd
clustering algorithm generates the cluster centers (as interior objects) for
each category and restructures the constricted training set with centroids.
This technique is amalgamated with AkNNclassifier that was prearranged with
text mining similarity measures. Eventually, significantweights and ranks were
assigned to each object in the new training set based upon their accessory
towards the object in testing set. Experiments conducted on Reuters-21578 a UCI
benchmark text mining data set, and comparisons with traditional kNNclassifier
designates the referredmethod yieldspreeminentrecitalin both clustering and
classification.


title: Observation of Kondo Effect in a Quadruple Quantum Dots

abstract:
  We investigate the Kondo effect in a quadruple quantum dot device of
coupled-double quantum dots (DQDs), which simultaneously contains intra-DQDs
and inter-DQDs coupling. A variety of novel behaviors are observed. The
differential conductance dI/dV is measured in the upper DQDs as a function of
source drain bias. It is found to exhibit multiple peaks, including a zero-bias
peak, where the number of peaks exceeds five. Alternatively, tuning the lower
DQDs yielded regions of four peaks. In addition, a Kondo-effect switcher is
demonstrated, using the lower DQDs as the controller.


title: Relativistic stellar jets: dynamics and non-thermal radiation

abstract:
  Relativistic stellar jets, produced in binary systems called microquasars,
propagate through media with different spatial scales releasing their energy in
the form of work and radiation from radio to gamma rays. There are several
medium-interaction scenarios that these jets can face. In particular, in
relativistic stellar jets the presence of a star is an unavoidable element
whose importance deserves to be studied. In the case of high-mass stars, their
powerful winds are likely to interact dynamically with the jet, but also
low-mass stars in the post-main sequence phase can present dense winds that
will act as an obstacle for the jet propagation. In this work, we present a
semi-qualitative discussion on the importance of the star for the evolution of
relativistic stellar jets.


title:
Unsupervised classification of uncertain data objects in spatial
  databases using computational geometry and indexing techniques

abstract:
  Unsupervised classification called clustering is a process of organizing
objects into groups whose members are similar in some way. Clustering of
uncertain data objects is a challenge in spatial data bases. In this paper we
use Probability Density Functions (PDF) to represent these uncertain data
objects, and apply Uncertain K-Means algorithm to generate the clusters. This
clustering algorithm uses the Expected Distance (ED) to compute the distance
between objects and cluster representatives. To further improve the performance
of UK-Means we propose a novel technique called Voronoi Diagrams from
Computational Geometry to prune the number of computations of ED. This
technique works efficiently but results pruning overheads. In order to reduce
these in pruning overhead we introduce R*-tree indexing over these uncertain
data objects, so that it reduces the computational cost and pruning overheads.
Our novel approach of integrating UK-Means with voronoi diagrams and R* Tree
applied over uncertain data objects generates imposing outcome when compared
with the accessible methods.


title: A year in the life of the low-mass X-ray transient Aql X-1

abstract:
  The Swift satellite monitored the quiescence of the low-mass X-ray binary
transient Aql X-1 on a weekly basis during the March-November 2012 interval. A
total of 42 observations were carried out in the soft X-ray (0.3-10 keV) band
with the X-ray Telescope on board Swift. We investigated the X-ray variability
properties of Aql X-1 during quiescence by tracking luminosity variations and
characterising them with a detailed spectral analysis. The source is highly
variable in this phase and two bright flares were detected, with peak
luminosities of ~4x10^{34} erg s^{-1} (0.3-10 keV). Quiescent X-ray spectra
require both a soft thermal component below ~2 keV and a hard component (a
power law tail) above ~2 keV. Changes in the power law normalisation alone can
account for the overall observed variability. Therefore, based on our data set,
the quiescent X-ray emission of Aql X-1 is consistent with the cooling of the
neutron star core and with mechanisms involving the accretion of matter onto
the neutron star surface or magnetosphere.


title: Existence theory for stochastic power law fluids

abstract:
  We consider the equations of motion for an incompressible Non-Newtonian fluid
in a bounded Lipschitz domain $G\subset\mathbb R^d$ during the time intervall
$(0,T)$ together with a stochastic perturbation driven by a Brownian motion
$W$. The balance of momentum reads as $$dv=\mathrm{div}\, S\,dt-(\nabla
v)v\,dt+\nabla\pi \,dt+f\,dt+\Phi(v)\,dW_t,$$ where $v$ is the velocity, $\pi$
the pressure and $f$ an external volume force. We assume the common power law
model $S(\varepsilon(v))=\big(1+|\varepsilon(v)|\big)^{p-2} \varepsilon(v)$ and
show the existence of weak (martingale) solutions provided
$p>\tfrac{2d+2}{d+2}$. Our approach is based on the $L^\infty$-truncation and a
harmonic pressure decomposition which are adapted to the stochastic setting.


title: A Note on the Longest Common Compatible Prefix Problem for Partial Words

abstract:
  For a partial word $w$ the longest common compatible prefix of two positions
$i,j$, denoted $lccp(i,j)$, is the largest $k$ such that $w[i,i+k-1]\uparrow
w[j,j+k-1]$, where $\uparrow$ is the compatibility relation of partial words
(it is not an equivalence relation). The LCCP problem is to preprocess a
partial word in such a way that any query $lccp(i,j)$ about this word can be
answered in $O(1)$ time. It is a natural generalization of the longest common
prefix (LCP) problem for regular words, for which an $O(n)$ preprocessing time
and $O(1)$ query time solution exists.
  Recently an efficient algorithm for this problem has been given by F.
Blanchet-Sadri and J. Lazarow (LATA 2013). The preprocessing time was
$O(nh+n)$, where $h$ is the number of "holes" in $w$. The algorithm was
designed for partial words over a constant alphabet and was quite involved.
  We present a simple solution to this problem with slightly better runtime
that works for any linearly-sortable alphabet. Our preprocessing is in time
$O(n\mu+n)$, where $\mu$ is the number of blocks of holes in $w$. Our algorithm
uses ideas from alignment algorithms and dynamic programming.


title: Bridges and random truncations of random matrices

abstract:
  We continue to study the squared Frobenius norm of a submatrix of a $n \times
n$ random unitary matrix. When the choice of the submatrix is deterministic and
its size is $[ns] \times [nt]$, we proved in a previous paper that, after
centering and without any rescaling, the two-parameter process converges in
distribution to a bivariate Brownian bridge. Here, we consider Bernoulli
independent choices of rows and columns with respective parameters $s$ and $t$.
We prove by subordination that after centering and rescaling by $n^{-1/2}$, the
process converges to another Gaussian process.


title:
On the Performance of Filters for Reduction of Speckle Noise in SAR
  Images off the Coast of the Gulf of Guinea

abstract:
  Synthetic Aperture Radar (SAR) imagery to monitor oil spills are some methods
that have been proposed for the West African sub-region. With the increase in
the number of oil exploration companies in Ghana (and her neighbors) and the
rise in the coastal activities in the sub-region, there is the need for proper
monitoring of the environmental impact of these socio-economic activities on
the environment. Detection and near real-time information about oil spills are
fundamental in reducing oil spill environmental impact. SAR images are prone to
some noise, which is predominantly speckle noise around the coastal areas. This
paper evaluates the performance of the mean and median filters used in the
preprocessing filtering to reduce speckle noise in SAR images for most image
processing algorithms.


title: Hard-photon production with b jets at hadron colliders

abstract:
  We present total and differential cross sections for the production of a hard
photon with up to two b jets at both the Tevatron with center-of-mass energy
1.96 TeV and the Large Hadron Collider with center-of-mass energy 8 TeV,
including Next-to-Leading Order (NLO) QCD corrections and full b-quark mass
effects. We study the theoretical uncertainty due to the residual
renormalization- and factorization-scale dependence and explain its origin on
the basis of the different subprocesses contributing to the NLO cross section.
We specifically address the case of the production of a hard photon with at
least one b jet and compare the NLO QCD predictions in both the Four- and
Five-Flavor-Number Schemes to the experimental measurements obtained by CDF and
D0.


title:
Magnetic Bianchi type II string cosmological model in loop quantum
  cosmology

abstract:
  The loop quantum cosmology of the Bianchi type II string cosmological model
in the presence of a homogeneous magnetic field is studied. We present the
effective equations which provide modifications to the classical equations of
motion due to quantum effects. The numerical simulations confirm that the big
bang singularity is resolved by quantum gravity effects.


title: Probabilistic Graphical Model Representation in Phylogenetics

abstract:
  Recent years have seen a rapid expansion of the model space explored in
statistical phylogenetics, emphasizing the need for new approaches to
statistical model representation and software development. Clear communication
and representation of the chosen model is crucial for: (1) reproducibility of
an analysis, (2) model development and (3) software design. Moreover, a
unified, clear and understandable framework for model representation lowers the
barrier for beginners and non-specialists to grasp complex phylogenetic models,
including their assumptions and parameter/variable dependencies.
  Graphical modeling is a unifying framework that has gained in popularity in
the statistical literature in recent years. The core idea is to break complex
models into conditionally independent distributions. The strength lies in the
comprehensibility, flexibility, and adaptability of this formalism, and the
large body of computational work based on it. Graphical models are well-suited
to teach statistical models, to facilitate communication among phylogeneticists
and in the development of generic software for simulation and statistical
inference.
  Here, we provide an introduction to graphical models for phylogeneticists and
extend the standard graphical model representation to the realm of
phylogenetics. We introduce a new graphical model component, tree plates, to
capture the changing structure of the subgraph corresponding to a phylogenetic
tree. We describe a range of phylogenetic models using the graphical model
framework and introduce modules to simplify the representation of standard
components in large and complex models. Phylogenetic model graphs can be
readily used in simulation, maximum likelihood inference, and Bayesian
inference using, for example, Metropolis-Hastings or Gibbs sampling of the
posterior distribution.


title:
Shells without drilling rotations: a representation theorem in the
  framework of the geometrically nonlinear 6-parameter resultant shell theory

abstract:
  In the framework of the geometrically nonlinear 6-parameter resultant shell
theory we give a characterization of the shells without drilling rotations.
These are shells for which the strain energy function $W$ is invariant under
the superposition of drilling rotations, i.e. $W$ is insensible to the
arbitrary local rotations about the third director $\boldsymbol{d}_3\,$. For
this type of shells we show that the strain energy density $W$ can be
represented as a function of certain combinations of the shell deformation
gradient $\boldsymbol{F}$ and the surface gradient of $\boldsymbol{d}_3\,$,
namely $W\big(\boldsymbol{F}^{ T}\boldsymbol{F} , \,
  \boldsymbol{F}^T \boldsymbol{d}_3 \,, \,
\boldsymbol{F}^T\mathrm{Grad}_s\boldsymbol{d}_3 \big)$. For the case of
isotropic shells we present explicit forms of the strain energy function $W$
having this property.


title: Second-order accurate finite volume method for well-driven flows

abstract:
  We consider a finite volume method for a well-driven fluid flow in a porous
medium. Due to the singularity of the well, modeling in the near-well region
with standard numerical schemes results in a completely wrong total well flux
and an inaccurate hydraulic head. Local grid refinement can help, but it comes
at computational cost. In this article we propose two methods to address well
singularity. In the first method the flux through well faces is corrected using
a logarithmic function, in a way related to the Peaceman correction. Coupling
this correction with a second-order accurate two-point scheme gives a greatly
improved total well flux, but the resulting scheme is still not even first
order accurate on coarse grids. In the second method fluxes in the near-well
region are corrected by representing the hydraulic head as a sum of a
logarithmic and a linear function. This scheme is second-order accurate.


title: New holographic dark energy and the modified Bekenstein-Hawking entropy

abstract:
  We show that in the standard derivation of the holographic dark energy some
conceptual issues are present. In particular, the formula used in the
literature to avoid black holes is not suitable in expanding universes. A more
suitable expression for a holographic motivated dark energy must contain the
energy density of the remaining matter content of the universe. However, we
show that under some reasonable hypothesis, we can obtain a new physically
motivated expression for the holographic dark energy. By considering an
appropriate time-dependence of the saturation-level parameter, a de Sitter
phase arises. Moreover, by adopting an argument similar to the original
Bekenstein one, our approach justifies a correction of the Bekenstein-Hawking
entropy for non-static isotropic expanding universes. Finally, we write down
the equation of state of a black hole embedded in Friedmann spacetimes.


title: Stochastic Stability of Event-triggered Anytime Control

abstract:
  We investigate control of a non-linear process when communication and
processing capabilities are limited. The sensor communicates with a controller
node through an erasure channel which introduces i.i.d. packet dropouts.
Processor availability for control is random and, at times, insufficient to
calculate plant inputs. To make efficient use of communication and processing
resources, the sensor only transmits when the plant state lies outside a
bounded target set. Control calculations are triggered by the received data. If
a plant state measurement is successfully received and while the processor is
available for control, the algorithm recursively calculates a sequence of
tentative plant inputs, which are stored in a buffer for potential future use.
This safeguards for time-steps when the processor is unavailable for control.
We derive sufficient conditions on system parameters for stochastic stability
of the closed loop and illustrate performance gains through numerical studies.


title:
Search for top-quark partners with charge 5/3 in the same-sign dilepton
  final state

abstract:
  A search for the production of heavy partners of the top quark with charge
5/3 is performed in events with a pair of same-sign leptons. The data sample
corresponds to an integrated luminosity of 19.5 inverse femtobarns and was
collected at sqrt(s) = 8 TeV by the CMS experiment. No significant excess is
observed in the data above the expected background and the existence of
top-quark partners with masses below 800 GeV is excluded at a 95% confidence
level, assuming they decay exclusively to tW. This is the first limit on these
particles from the LHC, and it is significantly more restrictive than previous
limits.


title:
The time-dependent reconstructed evolutionary process with a key-role
  for mass-extinction events

abstract:
  The homogeneous reconstructed evolutionary process is a birth-death process
without observed extinct lineages. Each species evolves independently with the
same diversification rates (speciation rate $\lambda(t)$ and extinction rate
$\mu(t)$) that may change over time. The process is commonly applied to model
species diversification where the data are reconstructed phylogenies, e.g.,
trees reconstructed from present-day molecular data, and used to infer
diversification rates.
  In the present paper I develop the general probability density of a
reconstructed tree under any time-dependent birth-death process. I elaborate on
how to adapt this probability density if conditioned on survival of one or two
initial lineages, or having sampled $n$ species and show how to transform
between the probability density of a reconstructed and the probability density
of the speciation times.
  I demonstrate the use of the general time-dependent probability density
functions by deriving the probability density of a reconstructed tree under a
birth-death-shift model with explicit mass-extinction events. I enrich this
compendium by providing and discussing several special cases, including: the
pure birth process, the pure death process, the birth-death process and the
critical branching process. Thus, I provide here most of the commonly used
birth-death models in a unified framework (e.g., same condition and same data)
with common notation.


title:
A dynamic probabilistic principal components model for the analysis of
  longitudinal metabolomic data

abstract:
  In a longitudinal metabolomics study, multiple metabolites are measured from
several observations at many time points. Interest lies in reducing the
dimensionality of such data and in highlighting influential metabolites which
change over time. A dynamic probabilistic principal components analysis (DPPCA)
model is proposed to achieve dimension reduction while appropriately modelling
the correlation due to repeated measurements. This is achieved by assuming an
autoregressive model for some of the model parameters. Linear mixed models are
subsequently used to identify influential metabolites which change over time.
The proposed model is used to analyse data from a longitudinal metabolomics
animal study.


title:
Nanoscale nuclear magnetic resonance with a 1.9-nm-deep nitrogen-vacancy
  sensor

abstract:
  We present nanoscale NMR measurements performed with nitrogen-vacancy (NV)
centers located down to about 2 nm from the diamond surface. NV centers were
created by shallow ion implantation followed by a slow, nanometer-by-nanometer
removal of diamond material using oxidative etching in air. The close proximity
of NV centers to the surface yielded large 1H NMR signals of up to 3.4 uT-rms,
corresponding to ~330 statistically polarized or ~10 fully polarized proton
spins in a ~(1.8 nm)^3 detection volume.


title:
On the effective radius of convergence for a given truncated power
  series expansion

abstract:
  An effective radius of convergence is defined and computed for any truncated
Taylor series. Applications to well known series are performed and is shown
that a range of good coincidence for actual and approximative plot can always
be found. For sufficient large degree of approximation the effective radius is
also an estimation of the true non-infinite radius of convergence.


title: Chern band insulators in magnetic field

abstract:
  The effect of a magnetic field on a two-dimensional Chern band insulator is
discussed. It is shown that, unlike the trivial insulator, an anomalous Hall
insulator with Chern number $C$ becomes a metal when a magnetic field is
applied at constant particle density, for any $C>0$. For a time reversal
invariant topological insulator with a spin Chern resolved number, $C_\uparrow=
- C_\downarrow=C$, the magnetic field induces a spin polarized spin Hall
insulator. We consider also the effect of a superlattice potential and extend
previous results for the quantization of the Hall conductance of filled
Hofstadter bands to this problem.


title: Higgs CAT

abstract:
  Higgs Computed Axial Tomography, an excerpt. Taking a closer look at the
camel-shaped tail of the light Higgs boson resonance and looking to the
transformation of the (camel-shaped) signal into a square-root--shaped signal +
interference with particular emphasis on residual theoretical uncertainties.


title:
Explicit invariant measures for infinite dimensional SDE driven by
  L\'evy noise with dissipative nonlinear drift I

abstract:
  We stu\dd y a class of nonlinear stochastic partial differential equations
with dissipative nonlinear drift, driven by L\'evy noise. Our work is divided
in two parts. In the present part I we first define a Hilbert-Banach setting in
which we can prove existence and uniqueness of solutions under general
assumptions on the drift and the L\'evy noise. We then prove a decomposition of
the solution process in a stationary component and a component which vanishes
asymptotically for large times in the $L^p-$sense, $p\geq1$. The law of the
stationary component is identified with the unique invariant probability
measure of the process.
  In part II we will exhibit the invariant measure as the limit of explicit
invariant measures for finite dimensional approximants.


title: An HI study of NGC 3521 - a galaxy with a slow-rotating halo

abstract:
  A study is presented of HI line observations of the nearby spiral galaxy NGC
3521 observed with the VLA as part of The HI Nearby Galaxy Survey. Clearly
evident in the HI data cube is the presence of an anomalous HI component that
is both diffuse and slow-rotating. The data cube is dynamically decomposed into
regular and anomalous HI components. A mass of M_HI=1.5 x 10^9 Msun is
estimated for the anomalous HI - 20 per cent of the total HI mass. Standard HI
data products and rotation curves are produced for each dynamical component. In
terms of circular rotation speed, the anomalous HI is found to lag the regular
HI by ~25 - 125 km/s. Three-dimensional models are generated and used to
determine the possible location of the anomalous HI. The results strongly
suggest it to be distributed in a thick disc with a scale-height of a few kpc
(~3.5 kpc). It is concluded that the anomalous HI in NGC 3521 constitutes a
slow-rotating halo gas component, consistent with similar findings for other
nearby galaxies. A study of the radial distribution of the anomalous HI shows
it to be spatially coincident with the inner regions of the stellar disc where
the star formation rate is highest. It is most likely a galactic fountain that
has deposited gas from the disc of the galaxy into the halo.


title: Plasmon-phonon coupling in large-area graphene dot and antidot arrays

abstract:
  Nanostructured graphene on SiO2 substrates pave the way for enhanced
light-matter interactions and explorations of strong plasmon-phonon
hybridization in the mid-infrared regime. Unprecedented large-area graphene
nanodot and antidot optical arrays are fabricated by nanosphere lithography,
with structural control down to the sub-100 nanometer regime. The interaction
between graphene plasmon modes and the substrate phonons is experimentally
demonstrated and structural control is used to map out the hybridization of
plasmons and phonons, showing coupling energies of the order 20 meV. Our
findings are further supported by theoretical calculations and numerical
simulations.


title:
Full susceptibility tensor for localized spin models with S=1, 3/2, 2,
  5/2 and with rhombic anisotropy

abstract:
  A general discussion of the simulation procedure of the full susceptibility
tensor and isothermal magnetization pseudovector for compounds comprising
weakly-interacting magnetic centers is presented. A single-crystal-sample as
well as a powder-sample case are considered. The procedure is used to obtain
explicit expressions for the full susceptibility tensor for spins S=1, 3/2, 2,
and 5/2 for non-vanishing rhombic local anisotropy and any form of
spectroscopic tensor.


title: A class of representations of Hecke algebras II

abstract:
  Let $W$ be a Coxeter group whose proper parabolic subgroups are finite.
According to Theorem~1.12 of [1], if the module of a finite $W$-digraph
$\Gamma$ is isomorphic to the module of a $W$-graph over $Q$, then $\Gamma$ is
acyclic. We extend this result to Coxeter groups with finite dihedral parabolic
subgroups and $W$-graphs over arbitrary fields $F$ of $C$. Also, an example is
provided showing the converse of this theorem is false. That is, there is an
example of a finite, acyclic $W$-digraph whose module does not afford a
$W$-graph.


title: How to take the interstellar weather with you in pulsar timing analysis

abstract:
  Here we present a Bayesian method of including discrete measurements of
dispersion measure due to the interstellar medium in the direction of a pulsar
as prior information in the analysis of that pulsar. We use a simple simulation
to show the efficacy of this method, where the inclusion of the additional
measurements results in both a significant increase in the precision with which
the timing model parameters can be obtained, and an improved upper limit on the
amplitude of any red noise in the dataset. We show that this method can be
applied where no multi-frequency data exists across much of the dataset, and
where there is no simultaneous multi-frequency data for any given observing
epoch. Including such information in the analysis of upcoming International
Pulsar Timing Array (IPTA) and European Pulsar Timing Array (EPTA) data
releases could therefore prove invaluable in obtaining the most constraining
limits on gravitational wave signals within those datasets.


title:
MetSizeR: selecting the optimal sample size for metabolomic studies
  using an analysis based approach

abstract:
  Background: Determining sample sizes for metabolomic experiments is important
but due to the complexity of these experiments, there are currently no standard
methods for sample size estimation in metabolomics. Since pilot studies are
rarely done in metabolomics, currently existing sample size estimation
approaches which rely on pilot data can not be applied.
  Results: In this article, an analysis based approach called MetSizeR is
developed to estimate sample size for metabolomic experiments even when
experimental pilot data are not available. The key motivation for MetSizeR is
that it considers the type of analysis the researcher intends to use for data
analysis when estimating sample size. MetSizeR uses information about the data
analysis technique and prior expert knowledge of the metabolomic experiment to
simulate pilot data from a statistical model. Permutation based techniques are
then applied to the simulated pilot data to estimate the required sample size.
  Conclusions: The MetSizeR methodology, and a publicly available software
package which implements the approach, are illustrated through real metabolomic
applications. Sample size estimates, informed by the intended statistical
analysis technique, and the associated uncertainty are provided.


title: Detection of coherent structures in photospheric turbulent flows

abstract:
  We study coherent structures in solar photospheric flows in a plage in the
vicinity of the active region AR 10930 using the horizontal velocity data
derived from Hinode/SOT magnetograms. Eulerian and Lagrangian coherent
structures are detected by computing the Q-criterion and the finite-time
Lyapunov exponents of the velocity field, respectively. Our analysis indicates
that, on average, the deformation Eulerian coherent structures dominate over
the vortical Eulerian coherent structures in the plage region. We demonstrate
the correspondence of the network of high magnetic flux concentration to the
attracting Lagrangian coherent structures (a-LCS) in the photospheric velocity
based on both observations and numerical simulations. In addition, the
computation of a-LCS provides a measure of the local rate of
contraction/expansion of the flow.


title:
The adoption and challenges of electronic voting technologies within the
  South African context

abstract:
  Literature has shown that countries such as Brazil and India have
successfully implemented electronic voting systems and other countries are at
various piloting stages to address many challenges associated with manual paper
based system such ascosts of physical ballot paper and other overheads,
electoral delays, distribution of electoral materials, and general lack of
confidence in the electoral process. It is in this context that this study
explores how South African can leverage the opportunities that e-voting
presents. Manual voting is often tedious, non-secure, and time-consuming, which
leads us to think about using electronic facilities to make the process more
efficient. This study proposes that the adoption of electronic voting
technologies could perhaps mitigate some of these issues and challengesin the
process improving the electoral process. The study used an on-line
questionnaire which was administered to a broader group of voters and an
in-depth semi-structured interview with the Independent Electoral Commission
officials. The analysis is based on thematic analysis and diffusion of
innovations theory is adopted as a theoretical lens of analysis. The findings
reveal that relative advantage, compatibility and complexity would determine
the intentions of South African voters and the Electoral Management Bodies
(IEC) to adopt e-voting technologies. Moreover, the findings also reveal
several other factorsthat could influence the adoption process. The study is
limited to only voters in Cape Town and these voters were expected to have some
access to the internet. The sample size limits the generalizability of the
findings of this study.


title:
Dynamical Casimir-Polder interaction between an atom and surface
  plasmons

abstract:
  We investigate the time-dependent Casimir-Polder potential of a polarizable
two-level atom placed near a surface of arbitrary material, after a sudden
change in the parameters of the system. Different initial conditions are taken
into account. For an initially bare ground-state atom, the time-dependent
Casimir-Polder energy reveals how the atom is "being dressed" by virtual,
matter-assisted photons. We also study the transient behavior of the
Casimir-Polder interaction between the atom and the surface starting from a
partially dressed state, after an externally induced change in the atomic level
structure or transition dipoles. The Heisenberg equations are solved through an
iterative technique for both atomic and field operators in the medium-assisted
electromagnetic field quantization scheme. We analyze in particular how the
time evolution of the interaction energy depends on the optical properties of
the surface, in particular on the dispersion relationof surface plasmon
polaritons. The physical significance and the limits of validity of the
obtained results are discussed in detail.


title:
A minimal mechanism leading to discontinuous phase transitions for
  short-range systems with absorbing states

abstract:
  Motivated by recent findings, we discuss the existence of a direct and robust
mechanism providing discontinuous absorbing transitions in short range systems
with single species, with no extra symmetries or conservation laws. We consider
variants of the contact process, in which at least two adjacent particles
(instead of one, as commonly assumed) are required to create a new species.
Many interaction rules are analyzed, including distinct cluster annihilations
and a modified version of the original pair contact process (PCP). Through
detailed time dependent numerical simulations we find that for our modified
models, the phase transitions are of first-order, hence contrasting with their
corresponding usual formulations in the literature, which are of second-order.
By calculating the order-parameter distributions, the obtained bimodal shapes
as well as the finite scale analysis reinforce coexisting phases, so a
discontinuous transition. These findings strongly suggest that above particle
creation requirements constitute a minimum and fundamental mechanism
determining the phase coexistence in short-range contact processes.


title:
Spin-orbit torque opposing the Oersted torque in ultrathin Co/Pt
  bilayers

abstract:
  Current-induced torques in ultrathin Co/Pt bilayers were investigated using
an electrically driven FMR technique. The angle dependence of the resonances,
detected by a rectification effect as a voltage, were analysed to determine the
symmetries and relative magnitudes of the spin-orbit torques. Both anti-damping
(Slonczewski) and field-like torques were observed. As the ferromagnet
thickness was reduced from 3 to 1 nm, the sign of the field-like torque
reversed. This observation is consistent with the emergence of a Rashba spin
orbit torque in ultra-thin bilayers.


title: Cross Section to Multiplicity Ratios at Very High Energy

abstract:
  Recent data from the LHC makes it possible to examine an old speculation that
at very high energy the total multiplicity and the cross section in elementary
particle interactions vary in parallel with energy. Using fits incorporating
the new data, it appears that the ratios of the total, elastic, and inelastic
cross sections to the average multiplicity N can in fact approach constants at
very high energy. The approach to the limit is however quite slow for the total
and inelastic cross sections and is not yet reached at LHC energies. The
elastic ratio sigma^{el}/N at 7 TeV, however, is not far from its asymptotic
value.


title: Human blood genotypes dynamics

abstract:
  We give a complete closed form description of the evolution of human blood
genotypes frequencies (in the ABO and Rh classification) after any (finite or
infinite) number of generations and for any initial distribution.


title: Thomas precession, persistent spin currents and quantum forces

abstract:
  We consider T-invariant spin currents induced by spin-orbit interactions
which originate from the confined motion of spin carriers in nanostructures.
The resulting Thomas spin precession is a fundamental and purely kinematic
relativistic effect occurring when the acceleration of carriers is not parallel
to their velocity. In the case, where the carriers (e.g. electrons) have
magnetic moment the forces due to the electric field of the spin current can,
in certain conditions, exceed the van der Waals-Casimir forces by several
orders of magnitude. We also discuss a possible experimental set-up tailored to
use these forces for checking the existence of a nonzero anomalous magnetic
moment of the photon.


title: Likelihood analysis for a class of beta mixed models

abstract:
  Beta regression models are a suitable choice for continuous response
variables on the unity interval. Random effects add further flexibility to the
models and accommodate data structures such as hierarchical, repeated measures
and longitudinal, which typically induce extra variability and/or dependence.
Closed expressions cannot be obtained for parameter estimation and numerical
methods are required and possibly combined with sampling algorithms. We focus
on likelihood inference and related algorithms for the analysis of beta mixed
models motivated by two real problems with grouped data structures. The first
is a study on a life quality index of industry workers with data collected
according to an hierarchical sampling scheme. The second is a study with a
nested and longitudinal data structure assessing the impact of hydroelectric
power plants upon measures of water quality indexes up, downstream and at the
reservoirs of the dammed rivers. Relevant scientific hypothesis are
investigated by comparing alternative models. The analysis uses different
algorithms including data-cloning, an alternative to numerical approximations
which also assess identifiability. Confidence intervals based on profiled
likelihoods are compared to those obtained by asymptotic quadratic
approximations, showing relevant differences for parameters related to the
random effects.


title:
Porosity measurements of interstellar ice mixtures using optical laser
  interference and extended effective medium approximations

abstract:
  Aims. This article aims to provide an alternative method of measuring the
porosity of multi-phase composite ices from their refractive indices and of
characterising how the abundance of a premixed contaminant (e.g., CO2) affects
the porosity of water-rich ice mixtures during omni-directional deposition.
Methods. We combine optical laser interference and extended effective medium
approximations (EMAs) to measure the porosity of three astrophysically relevant
ice mixtures: H2O:CO2=10:1, 4:1, and 2:1. Infrared spectroscopy is used as a
benchmarking test of this new laboratory-based method. Results. By
independently monitoring the O-H dangling modes of the different water-rich ice
mixtures, we confirm the porosities predicted by the extended EMAs. We also
demonstrate that CO2 premixed with water in the gas phase does not
significantly affect the ice morphology during omni-directional deposition, as
long as the physical conditions favourable to segregation are not reached. We
propose a mechanism in which CO2 molecules diffuse on the surface of the
growing ice sample prior to being incorporated into the bulk and then fill the
pores partly or completely, depending on the relative abundance and the growth
temperature.


title:
CheMPS2: a free open-source spin-adapted implementation of the density
  matrix renormalization group for ab initio quantum chemistry

abstract:
  The density matrix renormalization group (DMRG) has become an indispensable
numerical tool to find exact eigenstates of finite-size quantum systems with
strong correlation. In the fields of condensed matter, nuclear structure and
molecular electronic structure, it has significantly extended the system sizes
that can be handled compared to full configuration interaction, without losing
numerical accuracy. For quantum chemistry (QC), the most efficient
implementations of DMRG require the incorporation of particle number, spin and
point group symmetries in the underlying matrix product state (MPS) ansatz, as
well as the use of so-called complementary operators. The symmetries introduce
a sparse block structure in the MPS ansatz and in the intermediary contracted
tensors. If a symmetry is non-abelian, the Wigner-Eckart theorem allows to
factorize a tensor into a Clebsch-Gordan coefficient and a reduced tensor. In
addition, the fermion signs have to be carefully tracked. Because of these
challenges, implementing DMRG efficiently for QC is not straightforward.
Efficient and freely available implementations are therefore highly desired. In
this work we present CheMPS2, our free open-source spin-adapted implementation
of DMRG for ab initio QC. Around CheMPS2, we have implemented the augmented
Hessian Newton-Raphson complete active space self-consistent field method, with
exact Hessian. The bond dissociation curves of the 12 lowest states of the
carbon dimer were obtained at the DMRG(28 orbitals, 12 electrons,
D$_{\mathsf{SU(2)}}$=2500)/cc-pVDZ level of theory. The contribution of $1s$
core correlation to the $X^1\Sigma_g^+$ bond dissociation curve of the carbon
dimer was estimated by comparing energies at the DMRG(36o, 12e,
D$_{\mathsf{SU(2)}}$=2500)/cc-pCVDZ and DMRG-SCF(34o, 8e,
D$_{\mathsf{SU(2)}}$=2500)/cc-pCVDZ levels of theory.


title: Large-scale structure in superfluid Chaplygin gas cosmology

abstract:
  We investigate the growth of large-scale structure in the superfluid
Chaplygin gas (SCG) model. Both linear and non-linear growth, such as
$\sigma_8$ and the skewness $S_3$, are discussed. We find the growth factor of
SCG reduces to the EdS case at early times while differs from the $\Lambda$CDM
case in the large $a$ limit. We also find there will be much stricture growth
on large scales in the SCG scenario than in $\Lambda$CDM and the variations of
$\sigma_{8}$ and $S_3$ between SCG and $\Lambda$CDM can not be discriminated.


title:
Massive Star-Forming Host Galaxies of Quasars on Sloan Digital Sky
  Survey Stripe 82

abstract:
  The stellar properties of about 800 galaxies hosting optically luminous,
unobscured quasars at z < 0.6 are analyzed. Deep co-added Sloan Digital Sky
Survey (SDSS) images of the quasars on Stripe 82 are decomposed into nucleus
and host galaxy using point spread function and Sersic models. The systematic
errors in the measured galaxy absolute magnitudes and colors are estimated to
be less than 0.5 mag and 0.1 mag, respectively, with simulated quasar images.
The effect of quasar light scattered by the interstellar medium is also
carefully addressed. The measured quasar-to-galaxy ratio in total flux
decreases toward longer wavelengths, from ~8 in the u band to ~1 in the i and z
bands. We find that the SDSS quasars are hosted exclusively by massive galaxies
(stellar mass Mstar > 10^{10} Msun), which is consistent with previous results
for less luminous narrow-line (obscured) active galactic nuclei (AGNs). The
quasar hosts are very blue and almost absent on the red sequence, showing stark
contrast to the color-magnitude distribution of normal galaxies. The fact that
more powerful AGNs reside in galaxies with higher star-formation efficiency may
indicate that negative AGN feedback, if it exists, is not concurrent with the
most luminous phase of AGNs. We also find positive correlation between the mass
of supermassive black holes (SMBHs; Mbh) and host stellar mass, but the Mbh -
Mstar relation is offset toward large Mbh or small Mstar compared to the local
relation. While this could indicate that SMBHs grow earlier than do their host
galaxies, such an argument is not conclusive, as the effect may be dominated by
observational biases.


title:
Existence and higher arity iteration for total asymptotically
  nonexpansive mappings in uniformly convex hyperbolic spaces

abstract:
  This paper provides a fixed point theorem and iterative construction of a
common fixed point for a general class of nonlinear mappings in the setup of
uniformly convex hyperbolic spaces. We translate a multi-step iteration,
essentially due to Chidume and Ofoedu [4] in such setting for the approximation
of common fixed points of a finite family of total asymptotically nonexpansive
mappings. As a consequence, we establish strong and del-convergence results
which extend and generalize various corresponding results announced in the
current literature.


title:
Wave-packet dynamics of an atomic ion in a Paul trap: approximations and
  stability

abstract:
  Using numerical simulations of the time-dependent Schr\"odinger equation, we
study the full quantum dynamics of the motion of an atomic ion in a linear Paul
trap. Such a trap is based on a time-varying, periodic electric field, and
hence corresponds to a time-dependent potential for the ion, which we model
exactly. We compare the center of mass motion with that obtained from classical
equations of motion, as well as to results based on a time-independent
effective potential. We also study the oscillations of the width of the ion's
wave packet, including close to the border between stable (bounded) and
unstable (unbounded) trajectories. Our results confirm that the center-of-mass
motion always follow the classical trajectory, that the width of the wave
packet is bounded for trapping within the stability region, and therefore that
the classical trapping criterion are fully applicable to quantum motion.


title:
A frustrated spin-1 $J_{1}$--$J_{2}$ Heisenberg antiferromagnet: An
  anisotropic planar pyrochlore model

abstract:
  The zero-temperature ground-state (GS) properties and phase diagram of a
frustrated spin-1 $J_{1}$--$J_{2}$ Heisenberg model on the checkerboard square
lattice are studied, using the coupled cluster method. We consider the case
where the nearest-neighbour exchange bonds have strength $J_{1}>0$ and the
next-nearest-neighbour exchange bonds present (viz., in the checkerboard
pattern of the planar pyrochlore) have strength $J_{2} \equiv \kappa J_{1}>0$.
We find significant differences from both the spin-1/2 and classical versions
of the model. We find that the spin-1 model has a first phase transition at
$\kappa_{c_{1}} \approx 1.00 \pm 0.01$ (as does the classical model at
$\kappa_{{\rm cl}}=1$) between two antiferromagnetic phases, viz., a
quasiclassical N\'{e}el phase (for $\kappa < \kappa_{c_{1}}$) and one of the
infinitely degenerate family of quasiclassical phases (for $\kappa >
\kappa_{c_{1}}$) that exists in the classical model for $\kappa > \kappa_{{\rm
cl}}$, which is now chosen by the {\it order by disorder} mechanism as
(probably) the "doubled N\'{e}el" (or N\'{e}el$^{\ast}$) state. By contrast,
none of this family survives quantum fluctuations to form a stable GS phase in
the spin-1/2 case. We also find evidence for a second quantum critical point at
$\kappa_{c_{2}} \approx 2.0 \pm 0.5$ in the spin-1 model, such that for $\kappa
> \kappa_{c_{2}}$ the quasiclassical (N\'{e}el$^{\ast}$) ordering melts and a
nonclassical phase appears, which, on the basis of preliminary evidence,
appears unlikely to have crossed-dimer valence-bond crystalline (CDVBC)
ordering, as in the spin-1/2 case. Unlike in the spin-1/2 case, where the
N\'{e}el and CDVBC phases are separated by a phase with plaquette valence-bond
crystalline (PVBC) ordering, we find very preliminary evidence for such a PVBC
state in the spin-1 model for all $\kappa > \kappa_{c_{2}}$.


title: SU(3) magnet: finite-gap integration on the lowest genus curve

abstract:
  We consider the integrable system of isotropic SU(3) Landau-Lifshits equation
as a Hamiltonian system on a coadjoint orbit of the SU(3) loop group. We
connect the mentioned equation with an isotropic SU(3) magnet because it
describes the mean fields of magnetic and quadrupole moments in a spin-1
lattice. For the system of isotropic SU(3) Landau-Lifshits equation we perform
separation of variables in Sklyanin's manner, and integrate in the lowest
finite gap where the spectral curve is elliptic.


title:
HCO+ and radio continuum emission from the star forming region
  G75.78+0.34

abstract:
  We present 1.3 and 3.6cm radio continuum images and a HCO+ spectrum of the
massive star forming region G75.78+0.34 obtained with the Very Large Array
(VLA) and with the Berkley Illinois Maryland Association (BIMA) interferometer.
Three structures were detected in the continuum emission: one associated to the
well known cometary HII region, plus two more compact structures located at 6"
east and at 2" south of cometary HII region. Using the total flux and intensity
peak we estimated an electron density of ~1.5x10^4 cm^{-3}, an emission measure
of ~6x10^{7} cm^{-6} pc, a mass of ionized gas of ~3 M_Sun and a diameter of
0.05 pc for the cometary HII region, being typical values for an ultracompact
HII region. The HCO^+ emission is probably originated from the molecular
outflows previously observed in HCN and CO.


title:
The Gamma-count distribution in the analysis of experimental
  underdispersed data

abstract:
  Event counts are response variables with non-negative integer values
representing the number of times that an event occurs within a fixed domain
such as a time interval, a geographical area or a cell of a contingency table.
Analysis of counts by Gaussian regression models ignores the discreteness,
asymmetry and heterocedasticity and is inefficient, providing unrealistic
standard errors or possibily negative predictions of the expected number of
events. The Poisson regression is the standard model for count data with
underlying assumptions on the generating process which may be implausible in
many applications. Statisticians have long recognized the limitation of
imposing equidispersion under the Poisson regression model. A typical situation
is when the conditional variance exceeds the conditional mean, in which case
models allowing for overdispersion are routinely used. Less reported is the
case of underdispersion with fewer modelling alternatives and assessments
available in the literature. One of such alternatives, the Gamma-count model,
is adopted here in the analysis of an agronomic experiment designed to
investigate the effect of levels of defoliation on different phenological
states upon the number of cotton bolls. Results show improvements over the
Poisson model and the semiparametric quasi-Poisson model in capturing the
observed variability in the data. Estimating rather than assuming the
underlying variance process lead to important insights into the process.


title:
Collisionless microinstabilities in stellarators III - the
  ion-temperature-gradient mode

abstract:
  We investigate the linear theory of the ion-temperature-gradient (ITG) mode,
with the goal of developing a general understanding that may be applied to
stellarators. We highlight the Wendelstein 7X (W7-X) device. Simple fluid and
kinetic models that follow closely from existing literature are reviewed and
two new first-principle models are presented and compared with results from
direct numerical simulation. One model investigates the effect of regions of
strong localized shear, which are generic to stellarator equilibria. These
"shear spikes" are found to have a potentially significant stabilizing affect
on the mode; however, the effect is strongest at short wavelengths
perpendicular to the magnetic field, and it is found to be significant only for
the fastest growing modes in W7-X. A second model investigates the
long-wavelength limit for the case of negligible global magnetic shear. The
analytic calculation reveals that the effect of the curvature drive enters at
second order in the drift frequency, confirming conventional wisdom that the
ITG mode is slab-like at long wavelengths. Using flux tube simulations of a
zero-shear W7-X configuration, we observe a close relationship to an
axisymmetric configuration at a similar parameter point. It is concluded that
scale lengths of the equilibrium gradients constitute a good parameter space to
characterize the ITG mode. Thus, to optimize the magnetic geometry for ITG mode
stability, it may be fruitful to focus on local parameters, such as the
magnitude of bad curvature, connection length, and local shear at locations of
bad curvature (where the ITG mode amplitude peaks).


title:
Matrix methods for radial Schr\"{o}dinger eigenproblems defined on a
  semi-infinite domain

abstract:
  In this paper, we discuss numerical approximation of the eigenvalues of the
one-dimensional radial Schr\"{o}dinger equation posed on a semi-infinite
interval. The original problem is first transformed to one defined on a finite
domain by applying suitable change of the independent variable. The eigenvalue
problem for the resulting differential operator is then approximated by a
generalized algebraic eigenvalue problem arising after discretization of the
analytical problem by the matrix method based on high order finite difference
schemes. Numerical experiments illustrate the performance of the approach.


title:
Reply to "Comment on "Aharonov-Casher and Scalar Aharonov-Bohm
  Topological Effects""

abstract:
  In this Reply we argue that (i) the Hamiltonian, Eq. (17) in our paper (Phys.
Rev. Lett. 108, 070405 (2012)), is definitely Lorentz invariant; (ii) the
conditions of generating topological Aharonov-Casher(AC) and Scalar
Aharonov-Bohm (SAB) effects are essential and physically meaningful; (iii) the
Hamiltonians both in Phys. Rev. Lett. 74, 2847 (1995) and arXiv:1311.4011 are
not suitable to describe the polarized spinor particles.


title: Four remarks on spin coherent states

abstract:
  We discuss how to recognize the constellations seen in the Majorana
representation of quantum states. Then we give explicit formulas for the metric
and symplectic form on SU(2) orbits containing general number states. Their
metric and symplectic areas differ unless the states are coherent. Finally we
discuss some patterns that arise from the Lieb-Solovej map, and for dimensions
up to nine we find the location of those states that maximize the Wehrl-Lieb
entropy.


title:
Giant Photogalvanic Effect in Metamaterials Containing
  Non-Centrosymmetric Plasmonic Nanoparticles

abstract:
  Photoelectric properties of metamaterials containing non-centrosymmetric,
similarly oriented metallic nanoparticles embedded in a homogeneous
semiconductor matrix are theoretically studied. Due to the asymmetric shape of
the nanoparticle boundary, photoelectron emission acquires a preferred
direction, resulting in a photocurrent flow in that direction when
nanoparticles are uniformly illuminated by a homogeneous plane wave. This
effect is a direct analogy of the photogalvanic (or bulk photovoltaic) effect
known to exist in media with non-centrosymmetric crystal structure, such as
doped lithium niobate or bismuth ferrite, but is several orders of magnitude
stronger. Termed the giant plasmonic photogalvanic effect, the reported
phenomenon is valuable for characterizing photoemission and photoconductive
properties of plasmonic nanostructures, and can find many uses for
photodetection and photovoltaic applications.


title: Semiclassical treatment of pair creation in de Sitter space

abstract:
  We study a massive scalar field theory in de Sitter space. Using worldline
instanton approach, we calculate probability of pair production in weak-field
limit. In addition to exponential factor we derive pre-exponential factor.
Within this approach the vanishing probability for odd-dimensional de Sitter
space gets a clear geometrical interpretation. We find leading contribution to
imaginary part of two point correlator in $\phi^3$-theory.


title:
Two-loop fermion self-energy in reduced quantum electrodynamics and
  application to the ultra-relativistic limit of graphene

abstract:
  We compute the two-loop fermion self-energy in massless reduced quantum
electrodynamics for an arbitrary gauge using the method of integration by
parts. Focusing on the limit where the photon field is four-dimensional, our
formula involves only recursively one-loop integrals and can therefore be
evaluated exactly. From this formula, we deduce the anomalous scaling dimension
of the fermion field as well as the renormalized fermion propagator up to two
loops. The results are then applied to the ultra-relativistic limit of graphene
and compared with similar results obtained for four-dimensional and
three-dimensional quantum electrodynamics.


title: The hot spot in HT Cas during its Superoutburst

abstract:
  We present the analysis of eclipses observed in dwarf nova HT Cas during its
superoutburst in November 2010. Detection of hot spot was confirmed.


title:
Thresholds and expectation-thresholds of monotone properties with small
  minterms

abstract:
  Let $N$ be a finite set, let $p \in (0,1)$, and let $N_p$ denote a random
binomial subset of $N$ where every element of $N$ is taken to belong to the
subset independently with probability $p$ . This defines a product measure
$\mu_p$ on the power set of $N$, where for $\mathcal{A} \subseteq 2^N$
$\mu_p(\mathcal{A}) := Pr[N_p \in \mathcal{A}]$.
  In this paper we study upward-closed families $\mathcal{A}$ for which all
minimal sets in $\mathcal{A}$ have size at most $k$, for some positive integer
$k$. We prove that for such a family $\mu_p(\mathcal{A}) / p^k $ is a
decreasing function, which implies a uniform bound on the coarseness of the
thresholds of such families.
  We also prove a structure theorem which enables to identify in $\mathcal{A}$
either a substantial subfamily $\mathcal{A}_0$ for which the first moment
method gives a good approximation of its measure, or a subfamily which can be
well approximated by a family with all minimal sets of size strictly smaller
than $k$.
  Finally, we relate the (fractional) expectation threshold and the probability
threshold of such a family, using duality of linear programming. This is
related to the threshold conjecture of Kahn and Kalai.


title: Arbitrages in a Progressive Enlargement Setting

abstract:
  This paper completes the analysis of Choulli et al. Non-Arbitrage up to
Random Horizons and after Honest Times for Semimartingale Models and contains
two principal contributions. The first contribution consists in providing and
analysing many practical examples of market models that admit classical
arbitrages while they preserve the No Unbounded Profit with Bounded Risk (NUPBR
hereafter) under random horizon and when an honest time is incorporated for
particular cases of models. For these markets, we calculate explicitly the
arbitrage opportunities. The second contribution lies in providing simple
proofs for the stability of the No Unbounded Profit with Bounded Risk under
random horizon and after honest time satisfying additional important condition
for particular cases of models.


title:
The relativistic Feynman-Metropolis-Teller treatment at finite
  temperatures

abstract:
  The Feynman-Metropolis-Teller treatment of compressed atoms has been recently
generalized to relativistic regimes and applied to the description of static
and rotating white dwarfs in general relativity. We present here the extension
of this treatment to the case of finite temperatures and construct the
corresponding equation of state (EOS) of the system; applicable in a wide
regime of densities that includes both white dwarfs and neutron star outer
crusts. We construct the mass-radius relation of white dwarfs at finite
temperatures obeying this new EOS and apply it to the analysis of ultra
low-mass white dwarfs with $M\lesssim 0.2 M_\odot$. In particular, we analyze
the case of the white dwarf companion of PSR J1738+0333. The formulation is
then extrapolated to compressed nuclear matter cores of stellar dimensions,
systems with mass numbers $A\approx (m_{\rm Planck}/m_n)^3$ or mass $M_{\rm
core}\approx M_{\odot}$, where $m_{\rm Planck}$ and $m_n$ are the Planck and
the nucleon mass. For $T \ll m_e c^2/k_B \approx 5.9\times 10^9$ K, a family of
equilibrium configurations can be obtained with analytic solutions of the
ultra-relativistic Thomas-Fermi equation at finite temperatures. Such
configurations fulfill global but not local charge neutrality and have strong
electric fields on the core surface. We find that the maximum electric field at
the core surface is enhanced at finite temperatures with respect to the
degenerate case.


title: Quantum many-body models with cold atoms coupled to photonic crystals

abstract:
  Using cold atoms to simulate strongly interacting quantum systems represents
an exciting frontier of physics. However, as atoms are nominally neutral point
particles, this limits the types of interactions that can be produced. We
propose to use the powerful new platform of cold atoms trapped near
nanophotonic systems to extend these limits, enabling a novel quantum material
in which atomic spin degrees of freedom, motion, and photons strongly couple
over long distances. In this system, an atom trapped near a photonic crystal
seeds a localized, tunable cavity mode around the atomic position. We find that
this effective cavity facilitates interactions with other atoms within the
cavity length, in a way that can be made robust against realistic
imperfections. Finally, we show that such phenomena should be accessible using
one-dimensional photonic crystal waveguides in which coupling to atoms has
already been experimentally demonstrated.


title:
Non equilibrium phase transition with gravitational-like interaction in
  a cloud of cold atoms

abstract:
  We propose to use a cloud of laser cooled atoms in a quasi two dimensional
trap to investigate a non equilibrium collapse phase transition in presence of
gravitational-like interaction. Using theoretical arguments and numerical
simulations, we show that, like in two dimensional gravity, a transition to a
collapsed state occurs below a critical temperature. In addition and as a
signature of the non equilibrium nature of the system, persistent particles
currents, dramatically increasing close to the phase transition, are observed.


title: Effects of electron inertia in collisionless magnetic reconnection

abstract:
  We present a study of collisionless magnetic reconnection within the
framework of full two-fluid MHD for a completely ionized hydrogen plasma,
retaining the effects of the Hall current, electron pressure and electron
inertia. We performed 2.5D simulations using a pseudo-spectral code with no
dissipative effects. We check that the ideal invariants of the problem are
conserved down to round-off errors. Our results show that the change in the
topology of the magnetic field lines is exclusively due to the presence of
electron inertia. The computed reconnection rates remain a fair fraction of the
Alfv\'en velocity, which therefore qualifies as fast reconnection.


title:
Pseudofermion ferromagnetism in the Kondo lattices: a mean-field
  approach

abstract:
  Ground state ferromagnetism of the Kondo lattices is investigated within
slave fermion approach by Coleman and Andrei within a mean-field approximation
in the effective hybridization model. Conditions for formation of both
saturated (half-metallic) and non-saturated magnetic state are obtained for
various lattices. A description in terms of universal functions which depend
only on bare electron density of states (DOS) is presented. A crucial role of
the energy dependence of the bare DOS (especially, of DOS peaks) for the
small-moment ferromagnetism formation is demonstrated.


title: The variable ionized absorber in the Seyfert 2 Mrk 348

abstract:
  We present the results of the analysis of the X-ray spectrum of the Seyfert 2
Mrk 348, observed by Suzaku and XMM-Newton. The overall spectrum of Mrk 348 can
be described by a primary power law continuum seen through three layers of
absorption, of which one is neutral and two are ionised. Comparing Suzaku
(2008) and XMM-Newton (2002) observations we find variability of the X-ray
spectral curvature. We suggest that the variability can be explained through
the change of column density of both the neutral and one of the ionised
absorbers, together with a variation of the ionisation level of the same
absorber. We thus confirm one of the main features presented in past works,
where intrinsic column density variability up to $\sim 10^{23}$~cm$^{-2}$ was
observed on time scales of months. We also find that the photon index of the
underlying power law continuum ($\Gamma \sim 1.8$) is in agreement with the
previous observations of this Seyfert 2.


title: tmf Is Not a Ring Spectrum Quotient of String Bordism

abstract:
  This paper shows that $\mathrm{tmf}[1/6]$ is not a ring spectrum quotient of
$\mathrm{MO}\langle8\rangle[1/6]$. In fact, for any prime $p>3$ and any
sequence $X$ of homogeneous elements of $\pi_*\mathrm{MO}\langle8\rangle$, the
$\pi_*\mathrm{MO}\langle8\rangle$-module
$$\pi_*\big(\mathrm{MO}\langle8\rangle_{(p)}/X\big)$$ is not (even abstractly)
isomorphic to $\pi_*\mathrm{tmf}_{(p)}$.
  It does so by showing that, for any commutative ring spectrum $R$ and any
sequence $X$ of homogeneous elements of $\pi_*(R)$, there is an isomorphism of
graded $\mathbf{Q}$-vector spaces $$\pi_*(R/X)\otimes\mathbf{Q} \cong
\mathrm{H}_*(\mathrm{Tot}(\mathrm{K}(X)))\otimes\mathbf{Q},$$ where the
right-hand side is the rational homology of the (total) Koszul complex of $X$,
which is strictly bigger than $\pi_*(R)/(X)\otimes\mathbf{Q}$ unless $X$ is a
$\pi_*(R)\otimes\mathbf{Q}$-quasi-regular sequence. The result then follows
from the fact that the kernel of the $p$-local Witten genus cannot be generated
by a $\pi_*\mathrm{MO}\langle8\rangle\otimes\mathbf{Q}$-quasi-regular sequence.


title: Weyl-type laws for fractional p-eigenvalue problems

abstract:
  We prove an asymptotic estimate for the growth of variational eigenvalues of
fractional p-Laplacian eigenvalue problems on a smooth bounded domain.


title: Noncommutative ordered spaces : examples and counterexamples

abstract:
  In order to introduce the notion of causality in noncommutative geometry it
is necessary to extend Gelfand theory to the context of ordered spaces. In a
previous work we have already given an algebraic caracterization of the set of
non-decreasing continuous functions on an certain class of topological ordered
spaces. Such a set is called an isocone, and there exist at least two versions
of them (strong and weak) which coincide in the commutative case. In this paper
we introduce yet another breed of isocones, ultraweak isocones, which has a
simpler definition with a clear physical meaning. We show that ultraweak and
weak isocones are in fact the same, and completely classify those which live in
a finite dimensional $C^*$-algebra, hence corresponding to finite
noncommutative ordered spaces. We also give some examples in infinite
dimension.


title:
The growth of Temperley-Lieb type algebras with orthogonal and
  commutative relations associated with 2-colored edges graphs

abstract:
  It was studied the growth of Temperley-Lieb type algebras with orthogonal and
commutative relations associated with 2-colored edges graphs. Depending on the
structure of the graphs they can be finite-dimensional or to have linear or
exponential growth.


title:
Quantitative results for the Fleming-Viot Particle system and
  quasi-stationary distributions in discrete space

abstract:
  We show, for a class of discrete Fleming-Viot (or Moran) type particle
systems, that the convergence to the equilibrium is exponential for a suitable
Wassertein coupling distance. The approach provides an explicit quantitative
estimate on the rate of convergence. As a consequence, we show that the
conditioned process converges exponentially fast to a unique quasi-stationary
distribution. Moreover, by estimating the two-particle correlations, we prove
that the Fleming-Viot process converges, uniformly in time, to the conditioned
process with an explicit rate of convergence. We illustrate our results on the
examples of the complete graph and of N particles jumping on two points.


title:
The Implicit Function Theorem when the matrix $\frac{\partial
  F}{\partial y}(x,y)$ is only continuous at the base point

abstract:
  This article presents an elementary proof of the Implicit Function Theorem
for differentiable maps F(x,y), defined on a finite-dimensional Euclidean
space, with $\frac{\partial F}{\partial y}(x,y)$ only continuous at the base
point. In the case of a single scalar equation this continuity hypothesis is
not required. The Inverse Function Theorem is also shown. The proofs rely on
the mean-value and the intermediate-value theorems and Darboux's property (the
intermediate-value property for derivatives). These proofs avoid compactness
arguments, fixed-point theorems, and integration theory.


title:
Extension of the correlated Gaussian hyperspherical method to more
  particles and dimensions

abstract:
  The solution of the hyperangular Schr\"odinger equation for few-body systems
using a basis of explicitly correlated Gaussians remains numerically
challenging. This is in part due to the number of basis functions needed as the
system size grows, but also due to the fact that the number of numerical
integrations increases with the number of hyperangular degrees of freedom. This
paper shows that the latter challenge is no more. Using a delta function to fix
the hyperradius $R$, all matrix element calculations are reduced to a single
numerical integration regardless of system size $n$ or number of dimensions
$d$. In the special case of $d$ an even number, the matrix elements of the
noninteracting system are fully analytical. We demonstrate the use of the new
matrix elements for the 3-, 4-, and 5-body electron-positron systems with zero
total angular momentum $L$, positive parity $\pi$, and varied spins $S_+$ and
$S_-$.


title: Typologies of Computation and Computational Models

abstract:
  We need much better understanding of information processing and computation
as its primary form. Future progress of new computational devices capable of
dealing with problems of big data, internet of things, semantic web, cognitive
robotics and neuroinformatics depends on the adequate models of computation. In
this article we first present the current state of the art through
systematization of existing models and mechanisms, and outline basic structural
framework of computation. We argue that defining computation as information
processing, and given that there is no information without (physical)
representation, the dynamics of information on the fundamental level is
physical/ intrinsic/ natural computation. As a special case, intrinsic
computation is used for designed computation in computing machinery. Intrinsic
natural computation occurs on variety of levels of physical processes,
containing the levels of computation of living organisms (including highly
intelligent animals) as well as designed computational devices. The present
article offers a typology of current models of computation and indicates future
paths for the advancement of the field; both by the development of new
computational models and by learning from nature how to better compute using
different mechanisms of intrinsic computation.


title: Summing Large-N Towers in Colour Flow Evolution

abstract:
  We consider soft gluon evolution in the colour flow basis. We give explicit
expressions for the colour structure of the (one-loop) soft anomalous dimension
matrix for an arbitrary number of partons, and show how the successive
exponentiation of classes of large-N contributions can be achieved to provide a
systematic expansion of the evolution in terms of colour supressed
contributions.


title:
Study of EUV Emission and Properties of a Coronal Streamer from
  PROBA2/SWAP, Hinode/EIS and Mauna Loa Mk4 Observations

abstract:
  Wide-field EUV telescopes imaging in spectral bands sensitive to 1 MK plasma
on the Sun often observe extended ray-like coronal structures stretching
radially from active regions to distances of 1.5-2Rsun, which represent the EUV
counterparts of white-light streamers. To explain this phenomenon, we
investigated the properties of a streamer observed on October 20-21, 2010 by
the PROBA2/SWAP EUV telescope together with the Hinode/EIS spectrometer (HOP
165) and the Mauna Loa Mk4 white-light coronagraph. In the SWAP 174 A band
comprising the Fe ix - Fe xi lines, the streamer was detected to a distance of
2Rsun. We assume that the EUV emission is dominated by collisional excitation
and resonant scattering of monochromatic radiation coming from the underlying
corona. Below 1.2Rsun, the plasma density and temperature were derived from the
Hinode/EIS data by a line-ratio method. Plasma conditions in the streamer and
in the background corona above 1.2Rsun from disk center were determined by
forward-modeling the emission that best fit the observational data in both EUV
and white light. It was found that plasma in the streamer above 1.2Rsun is
nearly isothermal, with a temperature T=1.43+-0.08 MK. The hydrostatic
scale-height temperature determined from the evaluated density distribution was
significantly higher (1.72+-0.08 MK), which suggests the existence of outward
plasma flow along the streamer. We conclude that, inside the streamer,
collisional excitation provided more than 90% of the observed EUV emission;
whereas, in the background corona, the contribution of resonance scattering
became comparable with that of collisions at R > 2Rsun.


title: Using a model for telluric absorption in full-spectrum fits

abstract:
  The typical approach for removing telluric absorption lines from a science
spectrum is to divide it by the spectrum of a standard star of spectral type A
or B observed close in time and airmass. We present a new method, where we use
a model for the transmission of the Earth's atmosphere in a full-spectrum fit,
which determines the parameters for the stellar and Earth's atmosphere
simultaneously. This eliminates the need of a standard star completely.


title: CEAI: CCM based Email Authorship Identification Model

abstract:
  In this paper we present a model for email authorship identification (EAI) by
employing a Cluster-based Classification (CCM) technique. Traditionally,
stylometric features have been successfully employed in various authorship
analysis tasks; we extend the traditional feature-set to include some more
interesting and effective features for email authorship identification (e.g.
the last punctuation mark used in an email, the tendency of an author to use
capitalization at the start of an email, or the punctuation after a greeting or
farewell). We also included Info Gain feature selection based content features.
It is observed that the use of such features in the authorship identification
process has a positive impact on the accuracy of the authorship identification
task. We performed experiments to justify our arguments and compared the
results with other base line models. Experimental results reveal that the
proposed CCM-based email authorship identification model, along with the
proposed feature set, outperforms the state-of-the-art support vector machine
(SVM)-based models, as well as the models proposed by Iqbal et al. [1, 2]. The
proposed model attains an accuracy rate of 94% for 10 authors, 89% for 25
authors, and 81% for 50 authors, respectively on Enron dataset, while 89.5%
accuracy has been achieved on authors' constructed real email dataset. The
results on Enron dataset have been achieved on quite a large number of authors
as compared to the models proposed by Iqbal et al. [1, 2].


title: The degeneration of convex RP^2 structures on surfaces

abstract:
  Let M be a compact surface of negative Euler characteristic and let C(M) be
the deformation space of convex real projective structures on M. For every
choice of pants decomposition for M, there is a well known parameterization of
C(M) known as the Goldman parameterization. In this paper, we study how some
geometric properties of the real projective structure on M degenerates as we
deform it so that the internal parameters of the Goldman parameterization leave
every compact set while the boundary invariants remain bounded away from zero
and infinity.


title: The feedback of massive stars on interstellar astrochemical processes

abstract:
  Astrochemistry is a discipline that studies physico-chemical processes in
astrophysical environments. Such environments are characterized by conditions
that are substantially different from those existing in usual chemical
laboratories. Models which aim to explain the formation of molecular species in
interstellar environments must take into account various factors, including
many that are directly, or indirectly related to the populations of massive
stars in galaxies. The aim of this paper is to review the influence of massive
stars, whatever their evolution stage, on the physico-chemical processes at
work in interstellar environments. These influences include the ultraviolet
radiation field, the production of high energy particles, the synthesis of
radionuclides and the formation of shocks that permeate the interstellar
medium.


title: Broadband nanoelectromechanical phase shifting of light on a chip

abstract:
  We demonstrate an optomechanical phase shifter. By electrostatically
deflecting the nanofabricated mechanical structure, the effective index of a
nearby waveguide is changed and the resulting phase shift is measured using an
integrated Mach-Zehnder interferometer. Comparing to thermo-optical phase
shifters, our device does not consume power in static operation and also it can
operate over large frequency, wavelength, and power ranges. Operation in the
MHz range and sub-$\mu$s pulses are demonstrated.


title: Ionization rates in the heliosheath and in astrosheaths

abstract:
  In the heliosphere, especially in the inner heliosheath, mass-, momentum-,
and energy loading induced by the ionization of neutral interstellar species
plays an important, but for some species, especially Helium, an underestimated
role. We discuss the implementation of charge exchange and electron impact
processes for interstellar neutral Hydrogen and Helium and their implications
for further modeling. Especially, we emphasize the importance of electron
impact and a more sophisticated numerical treatment of the charge exchange
reactions. Moreover, we discuss the non-resonant charge exchange effects. The
rate coefficients are discussed and the influence of the cross-sections in the
(M)HD equations for different reactions are revised as well as their
representation in the collision integrals. Electron impact is in some regions
of the heliosphere, particularly in the heliotail, more effective than charge
exchange, and the ionization of neutral interstellar Helium contributes about
40% to the mass- and momentum loading in the inner heliosheath. The charge
exchange cross-sections need to be modeled with higher accuracy, especially in
view of the latest developments in their description. The ionization of Helium
and electron impact ionization of Hydrogen needs to be taken into account for
the modeling of the heliosheath and, in general, astrosheaths. Moreover, the
charge exchange cross-sections need to be handled in a more sophisticated way,
either by developing better analytic approximations or by solving the collision
integrals numerically.


title: PBW deformations of Koszul algebras over a nonsemisimple ring

abstract:
  Let $B$ be a generalized Koszul algebra over a finite dimensional algebra
$S$. We construct a bimodule Koszul resolution of $B$ when the projective
dimension of $S_B$ equals 2. Using this we prove a Poincar\'e-Birkhoff-Witt
(PBW) type theorem for a deformation of a generalized Koszul algebra. When the
projective dimension of $S_B$ is greater than 2, we construct bimodule Koszul
resolutions for generalized smash product algebras obtained from braidings
between finite dimensional algebras and Koszul algebras, and then prove the PBW
type theorem. The results obtained can be applied to standard Koszul
Artin-Schelter Gorenstein algebras in the sense of Minamoto and Mori.


title:
Compressed Quantitative MRI: Bloch Response Recovery through Iterated
  Projection

abstract:
  Inspired by the recently proposed Magnetic Resonance Fingerprinting
technique, we develop a principled compressed sensing framework for
quantitative MRI. The three key components are: a random pulse excitation
sequence following the MRF technique; a random EPI subsampling strategy and an
iterative projection algorithm that imposes consistency with the Bloch
equations. We show that, as long as the excitation sequence possesses an
appropriate form of persistent excitation, we are able to achieve accurate
recovery of the proton density, $T_1$, $T_2$ and off-resonance maps
simultaneously from a limited number of samples.


title:
Magnification of Photometric LRGs by Foreground LRGs and Clusters in
  SDSS

abstract:
  The magnification effect of gravitational lensing is a powerful probe of the
distribution of matter in the universe, yet it is frequently overlooked due to
the fact that its signal to noise is smaller than that of lensing shear.
Because its systematic errors are quite different from those of shear,
magnification is nevertheless an important approach with which to study the
distribution of large scale structure. We present lensing mass profiles of
spectroscopic luminous red galaxies (LRGs) and galaxy clusters determined
through measurements of the weak lensing magnification of photometric LRGs in
their background. We measure the change in detected galaxy counts as well as
the increased average galaxy flux behind the lenses. In addition, we examine
the average change in source color due to extinction by dust in the lenses. By
simultaneously fitting these three probes we constrain the mass profiles and
dust-to-mass ratios of the lenses in six bins of lens richness. For each
richness bin we fit an NFW halo mass, brightest cluster galaxy (BCG) mass,
second halo term, and dust-to-mass ratio. The resulting mass-richness relation
is consistent with previous analyses of the catalogs, and limits on the
dust-to-mass ratio in the lenses are in agreement with expectations. We explore
the effects of including the (low signal-to-noise) flux magnification and
reddening measurements in the analysis compared to using only the counts
magnification data; the additional probes significantly improve the agreement
between our measured mass-richness relation and previous results.


title: Distance Closures on Complex Networks

abstract:
  To expand the toolbox available to network science, we study the isomorphism
between distance and Fuzzy (proximity or strength) graphs. Distinct transitive
closures in Fuzzy graphs lead to closures of their isomorphic distance graphs
with widely different structural properties. For instance, the All Pairs
Shortest Paths (APSP) problem, based on the Dijkstra algorithm, is equivalent
to a metric closure, which is only one of the possible ways to calculate
shortest paths. Understanding and mapping this isomorphism is necessary to
analyse models of complex networks based on weighted graphs. Any conclusions
derived from such models should take into account the distortions imposed on
graph topology when converting proximity/strength into distance graphs, to
subsequently compute path length and shortest path measures. We characterise
the isomorphism using the max-min and Dombi disjunction/conjunction pairs. This
allows us to: (1) study alternative distance closures, such as those based on
diffusion, metric, and ultra-metric distances; (2) identify the operators
closest to the metric closure of distance graphs (the APSP), but which are
logically consistent; and (3) propose a simple method to compute alternative
distance closures using existing algorithms for the APSP. In particular, we
show that a specific diffusion distance is promising for community detection in
complex networks, and is based on desirable axioms for logical inference or
approximate reasoning on networks; it also provides a simple algebraic means to
compute diffusion processes on networks. Based on these results, we argue that
choosing different distance closures can lead to different conclusions about
indirect associations on network data, as well as the structure of complex
networks, and are thus important to consider.

categories: cs.SI cond-mat.dis-nn cs.IR nlin.CG physics.soc-ph


title:
Nuclear aspects of neutral current non-standard $\nu$-nucleus reactions
  and the role of the exotic $\mu^-\to e^{-}$ transitions experimental limits

abstract:
  The nuclear aspects of flavour changing neutral current (FCNC) processes,
predicted by various new-physics models to occur in the presence of nuclei, are
examined by computing the relevant nuclear matrix elements within the context
of the quasi-particle RPA using realistic strong two-body forces. One of our
aims is to explore the role of the non-standard interactions (NSI) in the
leptonic sector and specifically: (i) in lepton flavour violating (LFV)
processes involving the neutral particles $\nu_\ell$ and $\tilde{\nu}_\ell$,
$\ell = e,\mu,\tau$ and (ii) in charged lepton flavour violating (cLFV)
processes involving the charged leptons $\ell^-$ or $\ell^+$. As concrete
nuclear systems we have chosen the stopping targets of $\mu^-\rightarrow e^-$
conversion experiments, i.e. the $^{48}\mathrm{Ti}$ nucleus of the PRIME/PRISM
experiment at J-PARC and the $^{27}\mathrm{Al}$ of the COMET at J-PARC as well
as of the Mu2e at Fermilab. These experiments have been designed to reduce the
single event sensitivity down to $10^{-16}$--$10^{-18}$ in searching for
charged lepton mixing events. Our goal is, by taking advantage of our detailed
nuclear structure calculations and using the present limits or the sensitivity
of the aforementioned exotic $\mu^- \rightarrow e^-$ experiments, to put
stringent constraints on the parameters of NSI Lagrangians.


title:
Bounded weak solutions to matrix drift-diffusion model for spin-coherent
  electron transport in semiconductors

abstract:
  The global-in-time existence and uniqueness of bounded weak solutions to a
spinorial matrix drift-diffusion model for semiconductors is proved. Developing
the electron density matrix in the Pauli basis, the coefficients (charge
density and spin-vector density) satisfy a parabolic $4\times 4$
cross-diffusion system. The key idea of the existence proof is to work with
different variables: the spin-up and spin-down densities as well as the
parallel and perpendicular components of the spin-vector density with respect
to the magnetization. In these variables, the diffusion matrix becomes
diagonal. The proofs of the $L^\infty$ estimates are based on Stampacchia
truncation as well as Moser- and Alikakos-type iteration arguments. The
monotonicity of the entropy (or free energy) is also proved. Numerical
experiments in one space dimension using a finite-volume discretization
indicate that the entropy decays exponentially fast to the equilibrium state.


title:
Constraints on the CMB Temperature Evolution using Multi-Band
  Measurements of the Sunyaev Zel'dovich Effect with the South Pole Telescope

abstract:
  The adiabatic evolution of the temperature of the cosmic microwave background
(CMB) is a key prediction of standard cosmology. We study deviations from the
expected adiabatic evolution of the CMB temperature of the form $T(z)
=T_0(1+z)^{1-\alpha}$ using measurements of the spectrum of the Sunyaev
Zel'dovich Effect with the South Pole Telescope (SPT). We present a method for
using the ratio of the Sunyaev Zel'dovich signal measured at 95 and 150 GHz in
the SPT data to constrain the temperature of the CMB. We demonstrate that this
approach provides unbiased results using mock observations of clusters from a
new set of hydrodynamical simulations. We apply this method to a sample of 158
SPT-selected clusters, spanning the redshift range $0.05 < z < 1.35$, and
measure $\alpha = 0.017^{+0.030}_{-0.028}$, consistent with the standard model
prediction of $\alpha=0$. In combination with other published results, we
constrain $\alpha = 0.011 \pm 0.016$, an improvement of $\sim 20\%$ over
published constraints. This measurement also provides a strong constraint on
the effective equation of state in models of decaying dark energy
$w_\mathrm{eff} = -0.987^{+0.016}_{-0.017}$.


title:
Unique continuation for magnetic Schr\"odinger operator with singular
  potentials

abstract:
  In this paper we study unique continuation theorems for magnetic
Schr\"odinger equation via Carleman estimates. We use integration by parts
techniques in order to show these estimates. We consider electric and magnetic
potentials with strong singularities at the origin and some decay at infinity.


title: Stellar Spectral Signatures in High-Redshift Galaxies

abstract:
  Stellar emission and absorption lines are routinely observed in galaxies at
redshifts up to 5 with spectrographs on 8-10m class telescopes. While the
overall spectra are well understood and have been successfully modeled using
empirical and theoretical libraries, some challenges remain. Three issues are
discussed: determining abundances using stellar and interstellar spectral
lines, understanding the origin of the strong, stellar He II 1640 line, and
gauging the influence of stellar Lyman-alpha on the combined stellar+nebular
profile. All three issues can be tackled with recently created theoretical
stellar libraries for hot stars which take into account the
radiation-hydrodynamics of stellar winds.


title: A Compressed Sensing Framework for Magnetic Resonance Fingerprinting

abstract:
  Inspired by the recently proposed Magnetic Resonance Fingerprinting (MRF)
technique, we develop a principled compressed sensing framework for
quantitative MRI. The three key components are: a random pulse excitation
sequence following the MRF technique; a random EPI subsampling strategy and an
iterative projection algorithm that imposes consistency with the Bloch
equations. We show that theoretically, as long as the excitation sequence
possesses an appropriate form of persistent excitation, we are able to
accurately recover the proton density, T1, T2 and off-resonance maps
simultaneously from a limited number of samples. These results are further
supported through extensive simulations using a brain phantom.


title: An Analog Baseband Approach for Designing Full-Duplex Radios

abstract:
  Recent wireless testbed implementations have proven that full-duplex
communication is in fact possible and can outperform half-duplex systems. Many
of these implementations modify existing half-duplex systems to operate in
full-duplex. To realize the full potential of full-duplex, radios need to be
designed with self-interference in mind. In our work, we use an experimental
setup with a patch antenna prototype to characterize the self-interference
channel between two radios. In doing so, we form an analytical model to design
analog baseband cancellation techniques. We show that our cancellation scheme
can provide up to 10 dB improved signal strength, 2.5 bps/Hz increase in rate,
and a 10,000 improvement in BER as compared to the RF only cancellation
provided by the patch antenna.


title:
A Z-prime interpretation of Bd->K*mu+mu- data and consequences for high
  energy colliders

abstract:
  In this note, I examine the possible consequences for high energy colliders
of a Z-prime interpretation of the LHCb anomaly observed in the K*mu+mu- final
state. Two examples are elaborated in the framework of the so-called 331 model.
In the first one it is shown that LEP2 provides the tightest lower mass limit
for the Z-prime boson, above 8 TeV, while in the second one the lower mass
limit is set by ATLAS/CMS to about 3 TeV. It is then shown that precision
measurements at ILC 500 GeV can fully explore the underlying structure of the
model by measuring the fermion final states separately: leptons, charm, beauty
and top final states. Z-prime-Z mixing can also be substantial, thus leading to
possible effects almost observable at LEP1 and which can be precisely measured
at GigaZ. Discovery prospects for heavy bosons and heavy fermions at LHC are
also discussed .


title: Projected Gromov-Witten varieties in cominuscule spaces

abstract:
  A projected Gromov-Witten variety is the union of all rational curves of
fixed degree that meet two opposite Schubert varieties in a homogeneous space X
= G/P. When X is cominuscule we prove that the map from a related Gromov-Witten
variety is cohomologically trivial. This implies that all (3 point, genus zero)
K-theoretic Gromov-Witten invariants of X are determined by the projected
Gromov-Witten varieties, which extends an earlier result of Knutson, Lam, and
Speyer. Our proof uses that any projected Gromov-Witten variety in a
cominuscule space is also a projected Richardson variety.


title:
Algebraic actions of the discrete Heisenberg group: Expansiveness and
  homoclinic points

abstract:
  We survey some of the known criteria for expansiveness of principal algebraic
actions of countably infinite discrete groups. In the special case of the
discrete Heisenberg group we propose a new approach to this problem based on
Allan's local principle.
  Furthermore, we present a first example of an absolutely summable homoclinic
point for a nonexpansive action of the discrete Heisenberg group and use it to
construct an equal-entropy symbolic cover of the system.


title: Dynamical and radiative simulations of $\gamma$-ray jets in microquasars

abstract:
  The emission of $\gamma$-rays in jets emanating from the vicinity of
collapsed stellar remnants, in binary systems known as microquasars, is
investigated using a three dimensional relativistic hydrocode (PLUTO), in
combination with two in-house radiative transfer codes. Even though a great
number of stellar systems may be addressed by such models, we restrict
ourselves to the concrete example of the SS433 X-ray binary, the only
microquasar with a definite hadronic content in its jets, as verified from
spectral line observations. A variety of system configurations have been
examined, by employing a hadron-based emission mechanism. The dependence of the
$\gamma$-ray emissions on certain dynamical source properties, such as the
hydrodynamic parameters of the mass-flow density, the gas-pressure and the
temperature of the ejected matter, is simulated. Radiative properties,
especially the assumed high energy proton population inside the jet plasma, and
its effect on the calculated emission, are also examined. Two sets of initial
conditions of the chosen microquasar are employed, in order to cover different
scenarios pertaining to the system under consideration.


title:
Partitions of 4d Transition Metal Nuclei and Related Correlations Using
  the Core Cluster Model

abstract:
  In the present work we attempt to study the cluster model in the transition
metal region. The spectrum fitting method is studied for the selected nuclei
(88,90,92^Sr, 92,94^Zr, 98,100^Mo, 100,102,104, 106^Ru, 108,110^Pd and
112,114,116,118^Cd) with proton number (38 < ZT< 48) and mass number (88 < AT <
118). The core cluster charge products are correlated with the transition
probability B(E2 2+ -> 0+), the excitation energies and the product of valence
nucleon numbers of the parent nuclei.


title: Globally generated vector bundles on a smooth quadric surface

abstract:
  We give the classification of globally generated vector bundles of rank $2$
on a smooth quadric surface with $c_1\le (2,2)$ in terms of the indices of the
bundles, and extend the result to arbitrary higher rank case. We also
investigate their indecomposability and give the sufficient and necessary
condition on numeric data of vector bundles for indecomposability.


title:
Study of a high spatial resolution 10B-based thermal neutron detector
  for application in neutron reflectometry: the Multi-Blade prototype

abstract:
  Although for large area detectors it is crucial to find an alternative to
detect thermal neutrons because of the 3He shortage, this is not the case for
small area detectors. Neutron scattering science is still growing its
instruments' power and the neutron flux a detector must tolerate is increasing.
For small area detectors the main effort is to expand the detectors'
performances. At Institut Laue-Langevin (ILL) we developed the Multi-Blade
detector which wants to increase the spatial resolution of 3He-based detectors
for high flux applications. We developed a high spatial resolution prototype
suitable for neutron reflectometry instruments. It exploits solid 10B-films
employed in a proportional gas chamber. Two prototypes have been constructed at
ILL and the results obtained on our monochromatic test beam line are presented
here.


title: Computing the abelian heap of unpointed stable homotopy classes of maps

abstract:
  An algorithmic computation of the set of unpointed stable homotopy classes of
equivariant fibrewise maps was described in a recent paper of the author and
his collaborators. In the present paper, we describe a simplification of this
computation that uses an abelian heap structure on this set that was observed
in another paper of the author. A heap is essentially a group without a choice
of its neutral element; in addition, we allow it to be empty.


title: Comparison of bidirectional pedestrian flows by experiments

abstract:
  Intersections of pedestrian flows feature multiple types, varying in the
numbers of flow directions as well as intersecting angles. In this article
results from diverse bidirectional flow experiments with different intersecting
angles are compared. To analyze the transport capabilities the Voronoi method
is used to resolve the fine structure of the resulting velocity-density
relations and spatial dependence of the measurements. The fundamental diagrams
of various flow types are compared and show no apparent difference with respect
to the intersecting angle. This result indicates that head-on conflicts of
different types of flow have the same influence on the transport properties of
the system, which demonstrates the high self-organization capabilities of
pedestrians.


title:
P-adic Elliptic Quadratic Forms, Parabolic-Type Pseudodifferential
  Equations With Variable Coefficients, and Markov Processes

abstract:
  In this article we study the Cauchy problem for a new class of parabolic-type
pseudodifferential equations with variable coefficients for which the
fundamental solutions are transition density functions of Markov processes in
the four dimensional vector space over the field of p-adic numbers.