title:
On a link between kernel mean maps and Fraunhofer diffraction, with an
  application to super-resolution beyond the diffraction limit

abstract:
  We establish a link between Fourier optics and a recent construction from the
machine learning community termed the kernel mean map. Using the Fraunhofer
approximation, it identifies the kernel with the squared Fourier transform of
the aperture. This allows us to use results about the invertibility of the
kernel mean map to provide a statement about the invertibility of Fraunhofer
diffraction, showing that imaging processes with arbitrarily small apertures
can in principle be invertible, i.e., do not lose information, provided the
objects to be imaged satisfy a generic condition. A real world experiment shows
that we can super-resolve beyond the Rayleigh limit.


title: Randomized Low-Memory Singular Value Projection

abstract:
  Affine rank minimization algorithms typically rely on calculating the
gradient of a data error followed by a singular value decomposition at every
iteration. Because these two steps are expensive, heuristic approximations are
often used to reduce computational burden. To this end, we propose a recovery
scheme that merges the two steps with randomized approximations, and as a
result, operates on space proportional to the degrees of freedom in the
problem. We theoretically establish the estimation guarantees of the algorithm
as a function of approximation tolerance. While the theoretical approximation
requirements are overly pessimistic, we demonstrate that in practice the
algorithm performs well on the quantum tomography recovery problem.


title:
Implications of Higgs boson search data on the two-Higgs doublet models
  with a softly broken $Z_2$ symmetry

abstract:
  Based on current data of the Higgs boson search at the Large Hadron Collider,
we constrain the parameter space of the two-Higgs doublet models where a softly
broken $Z_2$ symmetry is employed to avoid flavor-changing neutral currents at
tree level. There are four types of Yukawa interactions under the $Z_2$ charge
assignments of the standard model fermions. We find that the model with type-II
Yukawa interactions can better explain the experimental data among all. In this
scenario, the couplings of the light CP-even Higgs boson $h$ with weak gauge
bosons are almost standard model-like or only slightly different in a small
range of $\tan\beta$. In particular, we scrutinize a well-constrained region
previously ignored by other analyses and study the phenomenology of the extra
Higgs bosons at the Large Hadron Collider.


title: Applicability of 0-1 Test for Strange Nonchaotic Attractors

abstract:
  We show that the recently introduced 0-1 test can successfully distinguish
between strange nonchaotic attractors(SNAs) and periodic/quasiperiodic/chaotic
attractors, by suitably choosing the arbitrary parameter associated with the
translation variables in terms of the golden mean number which avoids resonance
with the quasiperiodic force. We further characterize the transition from
quasiperiodic to chaotic motion via SNAs interms of the 0-1 test. We
demonstrate that the test helps to detect different dynamical transitions to
SNAs from quasiperiodic attractor or the transitions from SNAs to chaos. We
illustrate the performance of the 0-1 test in detecting transitions to SNAs in
quasiperiodically forced logistic map, cubic map, and Duffing oscillator.


title: Equidistribution in supersingular Hecke orbits

abstract:
  We prove an equidistribution result for Hecke operators acting on the basic
stratum of certain Shimura varieties. We relate the rate of convergence to the
bounds from the Ramanujan conjecture of certain cuspidal automorphic
representations on Gl_n for which this conjecture is known, and therefore we
obtain optimal estimates on the rate of convergence.


title: A new approach to the equivariant topological complexity

abstract:
  We present a new approach to equivariant version of the topological
complexity, called a symmetric topological complexity. It seems that the
presented approach is more adequate for the analysis of an impact of symmetry
on the the motion planning algoritm than the one introduced and studied by
Colman and Grant. We show many bounds for the symmetric topological complexity
comparing it with already known invariants and prove that in the case of a free
action it is equal to the Farber's topological complexity of the orbit space.
We define the Whitehead version of it.


title:
Ideal hydrodynamic scaling relations for a stagnated imploding spherical
  plasma liner formed by an array of merging plasma jets

abstract:
  This work presents scaling relations for the peak thermal pressure and
stagnation time (over which peak pressure is sustained) for an imploding
spherical plasma liner formed by an array of merging plasma jets. Results were
derived from three-dimensional (3D) ideal hydrodynamic simulation results
obtained using the smoothed particle hydrodynamics code SPHC. The 3D results
were compared to equivalent one-dimensional (1D) simulation results. It is
found that peak thermal pressure scales linearly with the number of jets and
initial jet density and Mach number, quadratically with initial jet radius and
velocity, and inversely with the initial jet length and the square of the
chamber wall radius. The stagnation time scales approximately as the initial
jet length divided by the initial jet velocity. Differences between the 3D and
1D results are attributed to the inclusion of thermal transport, ionization,
and perfect symmetry in the 1D simulations. A subset of the results reported
here formed the initial design basis for the Plasma Liner Experiment [S. C. Hsu
et al., Phys. Plasmas 19, 123514 (2012)].


title: Entanglement detection by Bragg scattering

abstract:
  We show how to measure the structural witnesses proposed in [P. Krammer et
al., Phys. Rev. Lett. 103, 100502 (2009)] for detecting entanglement in a spin
chain using photon scattering. The procedure, moreover, allows one to measure
the two-point correlation function of the spin array. This proposal could be
performed in existing experimental platforms realizing ion chains in Paul traps
or atomic arrays in optical lattices.


title:
MG13 Proceedings: A lattice Universe as a toy-model for inhomogeneous
  cosmology

abstract:
  We briefly report on a previously found new, approximate, solution to
Einstein field equations, describing a cubic lattice of spherical masses. This
model mimics in a satisfactory way a Universe which can be strongly
inhomogeneous at small scales, but quite homogeneous at large ones. As a
consequence of field equations, the lattice Universe is found to expand or
contract in the same way as the solution of a Friedmann Universe filled with
dust having the same average density. The study of observables indicates
however the possible existence of a fitting problem, i.e. the fact that the
Friedmann model obtained from past-lightcone observables does not match with
the one obtained by smoothing the matter content of the Universe.


title:
Understanding the like-sign dimuon charge asymmetry in $p \bar{p}$
  collisions

abstract:
  The D\O\ collaboration has measured the like-sign dimuon charge asymmetry in
$p \bar{p}$ collisions at the Fermilab Tevatron collider. The result is
significantly different from the standard model expectation of CP violation in
mixing. In this paper we consider the possible causes of this asymmetry and
identify one standard model source not considered before. It decreases the
discrepancy of the like-sign dimuon charge asymmetry with the standard model
prediction, although does not eliminate it completely.


title:
On universal norms and the first layers of Z_p-extensions of a number
  field

abstract:
  For an odd prime p and a number field F containing a primitive p-th root of
unity, we describe the Kummer radical A_F of the first layers of all the
Z_p-extensions of F in terms of universal norms of p-units along the cyclotomic
tower of F . We also study "twisted" radicals related to AF .


title:
A new bright eclipsing hot subdwarf binary from the ASAS and SuperWASP
  surveys

abstract:
  We report the discovery of a bright (V=11.6 mag) eclipsing hot subdwarf
binary of spectral type B with a late main sequence companion from the All Sky
Automated Survey (ASAS 102322-3737.0). Such systems are called HW Vir stars
after the prototype. The lightcurve shows a grazing eclipse and a strong
reflection effect. An orbital period of P=0.13927 d, an inclination of
i=65.86{\deg}, a mass ratio q=0.34, a radial velocity semiamplitude K_1=81.0
kms^-1, and other parameters are derived from a combined spectroscopic and
photometric analysis. The short period can only be explained by a common
envelope origin of the system. The atmospheric parameters (T_eff=28400 K, log
g=5.60) are consistent with a core helium-burning star located on the extreme
horizontal branch. In agreement with that we derived the most likely sdB mass
to be M_sdB=0.46M_sun, close to the canonical mass of such objects. The
companion is a late M-dwarf with a mass of M_comp=0.16 M_sun. ASAS
102322-3737.0 is the third brightest of only 12 known HW Virginis systems,
which makes it an ideal target for detailed spectroscopic studies and long term
photometric monitoring to search for period variations, e.g. caused by a
substellar companion.


title: Quantum Stabilization of a Closed Nielsen-Olesen String

abstract:
  We revisit the classical instability of closed strings in the Abelian Higgs
model. The instability is expressed by a vanishing energy as the torus-like
configuration shrinks to zero size. We treat the radius of the torus as a
collective coordinate and demonstrate that a quantum mechanical treatment of
this coordinate leads to a stabilization of the closed string at small radii.


title:
Magnetic tornadoes and chromospheric swirls -- Definition and
  classification

abstract:
  Chromospheric swirls are the observational signatures of rotating magnetic
field structures in the solar atmosphere, also known as magnetic tornadoes.
Swirls appear as dark rotating features in the core of the spectral line of
singly ionized calcium at a wavelength of 854.2 nm. This signature can be very
subtle and difficult to detect given the dynamic changes in the solar
chromosphere. Important steps towards a systematic and objective detection
method are the compilation and characterization of a statistically significant
sample of observed and simulated chromospheric swirls. Here, we provide a more
exact definition of the chromospheric swirl phenomenon and also present a first
morphological classification of swirls with three types: (I) Ring, (II) Split,
(III) Spiral. We also discuss the nature of the magnetic field structures
connected to tornadoes and the influence of limited spatial resolution on the
appearance of their photospheric footpoints.


title: A Simple Method for One-Loop Renormalization in Curved Space-Time

abstract:
  We present a simple method for deriving the renormalization counterterms from
the components of the energy-momentum tensor in curved space-time. This method
allows full control over the finite parts of the counterterms and provides
explicit expressions for each term separately. As an example, the method is
used for the self-interacting scalar field in a Friedmann-Robertson-Walker
metric in the adiabatic approximation, where we calculate the renormalized
equation of motion for the field and the renormalized components of the
energy-momentum tensor to fourth adiabatic order while including interactions
to one-loop order. Within this formalism the trace anomaly, including
contributions from interactions, is shown to have a simple derivation. We
compare our results to those obtained by two standard methods, finding
agreement with the Schwinger-DeWitt expansion but disagreement with adiabatic
subtractions for interacting theories.


title: Three Classes of Newtonian Three-Body Planar Periodic Orbits

abstract:
  We present the results of a numerical search for periodic orbits of three
equal masses moving in a plane under the influence of Newtonian gravity, with
zero angular momentum. A topological method is used to classify periodic
three-body orbits into families, which fall into four classes, with all three
previously known families belonging to one class. The classes are defined by
the orbits geometric and algebraic symmetries. In each class we present a few
orbits initial conditions, 15 in all; 13 of these correspond to distinct
orbits.


title: Killing vector field of the metric II+III on Tangent Bundle

abstract:
  The main purpose of the paper is to investigate Killing vector field on the
tangent bundle T(M_{n}) of the Riemannian manifold with respect to the
Levi-Civita connection of the metric II+III .


title: Successful strategies for competing networks

abstract:
  Competitive interactions represent one of the driving forces behind evolution
and natural selection in biological and sociological systems. For example,
animals in an ecosystem may vie for food or mates; in a market economy, firms
may compete over the same group of customers; sensory stimuli may compete for
limited neural resources in order to enter the focus of attention. Here, we
derive rules based on the spectral properties of the network governing the
competitive interactions between groups of agents organized in networks. In the
scenario studied here the winner of the competition, and the time needed to
prevail, essentially depend on the way a given network connects to its
competitors and on its internal structure. Our results allow assessing the
extent to which real networks optimize the outcome of their interaction, but
also provide strategies through which competing networks can improve on their
situation. The proposed approach is applicable to a wide range of systems that
can be modeled as networks.

categories: physics.soc-ph cs.SI nlin.AO q-bio.MN q-bio.PE


title: Residual entropy of spin-s triangular Ising antiferromagnet

abstract:
  We employ a thermodynamic integration method (TIM) to establish the values of
the residual entropy for the geometrically frustrated spin-s triangular Ising
antiferromagnet, with the spin values s = 1/2, 1, 3/2, 2 and 5/2. The case of s
= 1/2, for which the exact value is known, is used to assess the TIM
performance. We also obtain an analytical formula for the lower bound in a
general spin-s model and conjecture that it should reasonably approximate the
true residual entropy for sufficiently large $s$. Implications of the present
results in relation to reliability of the TIM as an indirect method for
calculating global thermodynamic quantities, such as the free energy and the
entropy, in similar systems involving frustration and/or higher spin values by
standard Monte Carlo sampling are briefly discussed.


title:
Unconventional Fano effect and off-resonance field enhancement in
  plasmonic coated spheres

abstract:
  We investigate light scattering by coated spheres composed of a dispersive
plasmonic core and a dielectric shell. By writing the absorption cross-section
in terms of the internal electromagnetic fields, we demonstrate it is an
observable sensitive to interferences that ultimately lead to the Fano effect.
Specially, we show that unconventional Fano resonances, recently discovered for
homogeneous spheres with large dielectric permittivities, can also occur for
metallic spheres coated with single dielectric layers. These resonances arise
from the interference between two electromagnetic modes with the same multipole
moment inside the shell and not from interactions between various plasmon modes
of different layers of the particle. In contrast to the case of homogeneous
spheres, unconventional Fano resonances in coated spheres exist even in the
Rayleigh limit. These resonances can induce an off-resonance field enhancement,
which is approximately one order of magnitude larger than the one achieved with
conventional Fano resonances. We find that unconventional and conventional Fano
resonances can occur at the same input frequency provided the dispersive core
has a negative refraction index. This leads to an optimal field enhancement
inside the particle, a result that could be useful for potential applications
in plasmonics.


title: On cascade decays of squarks at the LHC in NLO QCD

abstract:
  In this paper we present an analysis at NLO of the contribution from
squark-squark production to the experimental signature 2j + 2l + missing E_T
(+X) with opposite-sign same flavor leptons, taking into account decays and
experimental cuts. We consider the case in which one squark decays directly
into the lightest neutralino chi^0_1 and the other one into the second lightest
neutralino and subsequently into l^+l^-chi^0_1 via an intermediate slepton. On
one hand we study effects of the NLO corrections on invariant mass
distributions which can be used for future parameter determination. On the
other hand we analyze the impact on predictions for cut-and-count searches
using this experimental signature.


title:
The universal Associative envelope of the anti-Jordan triple system of
  $n \times n$ matrices

abstract:
  We show that the universal associative enveloping algebra of the simple
anti-Jordan triple system of all $n \times n$ matrices $(n \ge 2)$ over an
algebraically closed field of characteristic 0 is finite dimensional. We
investigate the structure of the universal envelope and focus on the monomial
basis, the structure constants, and the center. We explicitly determine the
decomposition of the universal envelope into matrix algebras. We classify all
finite dimensional irreducible representations of the simple anti-Jordan triple
system, and show that the universal envelope is semisimple. We also provide an
example to show that the universal enveloping algebras of anti-Jordan triple
systems are not necessary to be finite-dimensional.


title: Quasi-likelihood for Spatial Point Processes

abstract:
  Fitting regression models for intensity functions of spatial point processes
is of great interest in ecological and epidemiological studies of association
between spatially referenced events and geographical or environmental
covariates. When Cox or cluster process models are used to accommodate
clustering not accounted for by the available covariates, likelihood based
inference becomes computationally cumbersome due to the complicated nature of
the likelihood function and the associated score function. It is therefore of
interest to consider alternative more easily computable estimating functions.
We derive the optimal estimating function in a class of first-order estimating
functions. The optimal estimating function depends on the solution of a certain
Fredholm integral equation which in practice is solved numerically. The
approximate solution is equivalent to a quasi-likelihood for binary spatial
data and we therefore use the term quasi-likelihood for our optimal estimating
function approach. We demonstrate in a simulation study and a data example that
our quasi-likelihood method for spatial point processes is both statistically
and computationally efficient.


title: A statistical study of SDSS radio-emitters

abstract:
  The cross-correlation of the Sloan Digital Sky Survey Data Release 7 with the
Faint Images of the Radio Sky at Twenty-Centimeters survey allows for a
multiwavelength statistical study of radio-optical galaxy properties on a very
large number of sources. The correlation we find between $L_{[20
cm]}/L_{[H\alpha]}$ and optical emission line ratios suggests that the origin
of the emission in powerful radio-galaxies is of nuclear rather than of stellar
origin. In particular, the spectroscopic classification in Seyferts, Low
Ionization Narrow Emission Regions (LINERs) and star-forming galaxies provided
by emission-line diagnostic diagrams peaks on the AGN region for higher $L_{[20
cm]}/L_{[H\alpha]}$ values. The trend differs from Seyferts to LINERs. The
[NII]/H$\alpha$ vs. equivalent width of the H$\alpha$ line diagram confirms the
LINER classification for most of those that have been identified with the
traditional diagnostic diagrams. A small fraction of sources seem to be powered
by post-AGB stars instead.


title: The dynamic quasiperpendicular shock: Cluster discoveries

abstract:
  The physics of collisionless shocks is a very broad topic which has been
studied for more than five decades. However, there are a number of important
issues which remain unresolved. The energy repartition amongst particle
populations in quasiperpendicular shocks is a multi-scale process related to
the spatial and temporal structure of the electromagnetic fields within the
shock layer. The most important processes take place in the close vicinity of
the major magnetic transition or ramp region. The distribution of
electromagnetic fields in this region determines the characteristics of ion
reflection and thus defines the conditions for ion heating and energy
dissipation for supercritical shocks and also the region where an important
part of electron heating takes place. All of these processes are crucially
dependent upon the characteristic spatial scales of the ramp and foot region
provided that the shock is stationary. The earliest studies of collisionless
shocks identified nonlinearity, dissipation, and dispersion as the processes
that arrest the steepening of the shock transition. Their relative role
determines the scales of electric and magnetic fields, and so control the
characteristics of processes such as of ion reflection, electron heating and
particle acceleration. The purpose of this review is to address a subset of
unresolved problems in collisionless shock physics from experimental point of
view making use multi-point observations onboard Cluster satellites. The
problems we address are determination of scales of fields and of a scale of
electron heating, identification of energy source of precursor wave train, an
estimate of the role of anomalous resistivity in energy dissipation process by
means of measuring short scale wave fields, and direct observation of
reformation process during one single shock front crossing.


title:
A Directional Gradient-Curvature Method for Gap Filling of Gridded
  Environmental Spatial Data with Potentially Anisotropic Correlations

abstract:
  We introduce the Directional Gradient-Curvature (DGC) method, a novel
approach for filling gaps in gridded environmental data. DGC is based on an
objective function that measures the distance between the directionally
segregated normalized squared gradient and curvature energies of the sample and
entire domain data. DGC employs data-conditioned simulations, which sample the
local minima configuration space of the objective function instead of the full
conditional probability density function. Anisotropy and non-stationarity can
be captured by the local constraints and the direction-dependent global
constraints. DGC is computationally efficient and requires minimal user input,
making it suitable for automated processing of large (e.g., remotely sensed)
spatial data sets. Various effects are investigated on synthetic data. The
gap-filling performance of DGC is assessed in comparison with established
classification and interpolation methods using synthetic and real satellite
data, including a skewed distribution of daily column ozone values. It is shown
that DGC is competitive in terms of cross validation performance.


title: Narrow-line HI and cold structures in the ISM

abstract:
  Context. In the HI line profiles in the Leiden-Argentina-Bonn (LAB) all-sky
database, we have found a population of very cold HI clouds. So far, the role
of these clouds in the interstellar medium (ISM) has remained unclear. Aims. In
this paper, we attempt to confirm the existence of the narrow-line HI emission
(NHIE) clouds by using the data from the Parkes Galactic all-sky survey (GASS)
and try to find their place among other coldest constituents of the ISM.
Methods. We repeat the search of NHIE with the GASS data and derive or compile
some preliminary estimates for the distribution, temperatures, distances,
linear sizes, column and number densities, masses, and the composition of NHIE
clouds, and compare these data with corresponding estimates for HI
self-absorption (HISA) features, the Planck cold clumps (CC), and infrared dark
clouds (IRDC). Results. We demonstrate that from LAB and GASS we can separate
comparable NHIE complexes, and the properties of the obtained NHIE clouds are
very similar to those of HISA features, but both of these types of clouds are
somewhat warmer and more extended and have lower densities than the cores in
the Planck CC and IRDC. Conclusions. We conclude that NHIE may be the same type
of clouds as HISA, but in different observing conditions, in the same way as
the Planck CC and IRDC are most likely similar ISM structures in different
observing conditions and probably in slightly different evolutionary stages.
Both NHIE and HISA may be an intermediate phase between the diffuse cold
neutral medium and star-forming molecular clumps represented by the Planck CC
and IRDC.


title: Reverse dynamical evolution of Eta Chamaeleontis

abstract:
  In the scope of the star formation process, it is unclear how the environment
shapes the initial mass function (IMF). While observations of open clusters
propose a universal picture for the IMF from the substellar domain up to a few
solar masses, the young association eta Chamaeleontis presents an apparent lack
of low mass objects (m<0.1 Msun). Another unusual feature of this cluster is
the absence of wide binaries with a separation > 50 AU. We aim to test whether
dynamical evolution alone can reproduce the peculiar properties of the
association assuming a universal IMF. We use a pure N-body code to simulate the
dynamical evolution of the cluster for 10 Myr, and compare the results with
observations. A wide range of values for the initial parameters are tested in
order to identify the initial state that would most likely lead to
observations. In this context we also investigate the influence of the initial
binary population on the dynamics and the possibility of having a discontinuous
single IMF near the transition to the brown dwarf regime. We consider as an
extreme case an IMF with no low mass systems (m<0.1 Msun). The initial
configurations cover a wide range of initial density, from 10^2 to 10^8
stars/pc^3, in virialized, hot and cold dynamical state. We do not find any
initial state that would evolve from a universal single IMF to fit the
observations. Only when starting with a truncated IMF without any very low mass
systems and no wide binaries, can we reproduce the cluster core properties with
a success rate of 10% at best. Pure dynamical evolution alone cannot explain
the observed properties of eta Cha from universal initial conditions. The lack
of brown dwarfs and very low mass stars, and the peculiar binary properties
(low binary fraction and lack of wide binaries), are probably the result of the
star formation process in this association. (abridged)


title:
Statefinder hierarchy of bimetric and galileon models for concordance
  cosmology

abstract:
  In this paper, we use Statefinder hierarchy method to distinguish between
bimetric theory of massive gravity, galileon modified gravity and DGP models
applied to late time expansion of the universe. We also carry out comparison
between bimetric and DGP models using Statefinder pairs {r, s} and {r, q}. We
show that statefinder diagnostic can differentiate between {\Lambda}CDM and
above mentioned cosmological models of dark energy, and finally show that
Statefinder S2 is an excellent discriminant of {\Lambda}CDM and modified
gravity models.


title: Living in Curved Momentum Space

abstract:
  In this paper we review some aspects of relativistic particles' mechanics in
the case of a non-trivial geometry of momentum space. We start with showing how
the curved momentum space arises in the theory of gravity in 2+1 dimensions
coupled to particles, when (topological) degrees of freedom of gravity are
solved for. We argue that there might exist a similar topological phase of
quantum gravity in 3+1 dimensions. Then we characterize the main properties of
the theory of interacting particles with curved momentum space and the
symmetries of the action. We discuss the spacetime picture and the emergence of
the principle of relative locality, according to which locality of events is
not absolute but becomes observer dependent, in the controllable, relativistic
way. We conclude with the detailed review of the most studied kappa-Poincare
framework, which corresponds to the de Sitter momentum space.


title: Inhomogeneous Universe in Loop Quantum Gravity

abstract:
  It is discussed a truncation of the kinematical Hilbert space of Loop Quantum
Gravity, which describes the dynamical system associated with an inhomogeneous
cosmological model.


title: Deformations and quasiparticle spectra of nuclei in the nobelium region

abstract:
  We have performed self-consistent Skyrme Hartree-Fock-Bogolyubov calculations
for nuclei close to $^{254}$No. Self-consistent deformations, including
$\beta_{2,4,6,8}$ as functions of the rotational frequency, were determined for
even-even nuclei $^{246,248,250}$Fm, $^{252,254}$No, and $^{256}$Rf. The
quasiparticle spectra for N=151 isotones and Z=99 isotopes were calculated and
compared with experimental data and the results of Woods-Saxon calculations. We
found that our calculations give high-order deformations similar to those
obtained for the Woods-Saxon potential, and that the experimental quasiparticle
energies are reasonably well reproduced.


title:
On sparse sensing and sparse sampling of coded signals at sub-Landau
  rates

abstract:
  Advances of information-theoretic understanding of sparse sampling of
continuous uncoded signals at sampling rates exceeding the Landau rate were
reported in recent works. This work examines sparse sampling of coded signals
at sub-Landau sampling rates. It is shown that with coded signals the Landau
condition may be relaxed and the sampling rate required for signal
reconstruction and for support detection can be lower than the effective
bandwidth. Equivalently, the number of measurements in the corresponding sparse
sensing problem can be smaller than the support size. Tight bounds on
information rates and on signal and support detection performance are derived
for the Gaussian sparsely sampled channel and for the frequency-sparse channel
using the context of state dependent channels. Support detection results are
verified by a simulation. When the system is high-dimensional the required SNR
is shown to be finite but high and rising with decreasing sampling rate, in
some practical applications it can be lowered by reducing the a-priory
uncertainty about the support e.g. by concentrating the frequency support into
a finite number of subbands.


title: Products of twists, geodesic-lengths and Thurston shears

abstract:
  Thurston introduced shear deformations (cataclysms) on geodesic laminations -
deformations including left and right displacements along geodesics. For
hyperbolic surfaces with cusps, we consider shear deformations on disjoint
unions of ideal geodesics. The length of a balanced weighted sum of ideal
geodesics is defined and the Weil-Petersson (WP) duality of shears and the
defined length is established. The Poisson bracket of a pair of balanced weight
systems on a set of disjoint ideal geodesics is given in terms of an elementary
2-form. The symplectic geometry of balanced weight systems on ideal geodesics
is developed. Equality of the Fock shear coordinate algebra and the WP Poisson
algebra is established. The formula for the WP Riemannian pairing of shears is
also presented.


title:
Non-relativistic pair annihilation of nearly mass degenerate neutralinos
  and charginos II. P-wave and next-to-next-to-leading order S-wave
  coefficients

abstract:
  This paper is a continuation of an earlier work (arXiv:1210.7928) which
computed analytically the tree-level annihilation rates of a collection of
non-relativistic neutralino and chargino two-particle states in the general
MSSM. Here we extend the results by providing the next-to-next-to-leading order
corrections to the rates in the non-relativistic expansion in momenta and mass
differences, which include leading P-wave effects, in analytic form. The
results are a necessary input for the calculation of the Sommerfeld-enhanced
dark matter annihilation rates including short-distance corrections at
next-to-next-to-leading order in the non-relativistic expansion in the general
MSSM with neutralino LSP.


title:
Ultrasound-induced acoustophoretic motion of microparticles in three
  dimensions

abstract:
  We derive analytical expressions for the three-dimensional (3D)
acoustophoretic motion of spherical microparticles in rectangular
microchannels. The motion is generated by the acoustic radiation force and the
acoustic streaming-induced drag force. In contrast to the classical theory of
Rayleigh streaming in shallow, infinite, parallel-plate channels, our theory
does include the effect of the microchannel side walls. The resulting
predictions agree well with numerics and experimental measurements of the
acoustophoretic motion of polystyrene spheres with nominal diameters of 0.537
um and 5.33 um. The 3D particle motion was recorded using astigmatism particle
tracking velocimetry under controlled thermal and acoustic conditions in a
long, straight, rectangular microchannel actuated in one of its transverse
standing ultrasound-wave resonance modes with one or two half-wavelengths. The
acoustic energy density is calibrated in situ based on measurements of the
radiation dominated motion of large 5-um-diam particles, allowing for
quantitative comparison between theoretical predictions and measurements of the
streaming induced motion of small 0.5-um-diam particles.


title:
Symmetry-Protected Majorana Fermions in Topological Crystalline
  Superconductors: Theory and Application to Sr2RuO4

abstract:
  Crystal point group symmetry is shown to protect Majorana fermions (MFs) in
spinfull superconductors (SCs). We elucidate the condition necessary to obtain
MFs protected by the point group symmetry. We argue that superconductivity in
Sr2RuO4 hosts a topological phase transition to a topological crystalline SC,
which accompanies a d-vector rotation under a magnetic field along the c-axis.
Taking all three bands and spin-orbit interactions into account,
symmetry-protected MFs in the topological crystalline SC are identified.
Detection of such MFs provides evidence of the d-vector rotation in Sr2RuO4
expected from Knight shift measurements but not yet verified.


title: Apollonian Equilateral Triangles

abstract:
  Given an equilateral triangle with $a$ the square of its side length and a
point in its plane with $b$, $c$, $d$ the squares of the distances from the
point to the vertices of the triangle, it can be computed that $a$, $b$, $c$,
$d$ satisfy $3(a^2+b^2+c^2+d^2)=(a+b+c+d)^2$. This paper derives properties of
quadruples of nonnegative integers $(a,\, b,\, c,\, d)$, called triangle
quadruples, satisfying this equation. It is easy to verify that the operation
generating $(a,\, b,\, c,\, a+b+c-d)$ from $(a,\, b,\, c,\, d)$ preserves this
feature and that it and analogous ones for the other elements can be
represented by four matrices. We examine in detail the triangle group, the
group with these operations as generators, and completely classify the orbits
of quadruples with respect to the triangle group action. We also compute the
number of triangle quadruples generated after a certain number of operations
and approximate the number of quadruples bounded by characteristics such as the
maximal element. Finally, we prove that the triangle group is a hyperbolic
Coxeter group and derive information about the elements of triangle quadruples
by invoking Lie groups. We also generalize the problem to higher dimensions.


title: Turbulent Dissipation Challenge: A community Driven Effort

abstract:
  The goal of the present document is to present the idea of, and convince the
community to participate in, Turbulent Dissipation Challenge. The idea was
discussed in Solar Heliospheric and Interplanetary ENvironment (SHINE) 2012
meeting. The proponents of the idea Tulasi Parashar and Chadi Salem have
prepared this document to circulate the idea in the community.
  The Turbulent Dissipation Challenge idea is to bring the community together
and simulate the same set of problems and try to come to a common set of
conclusions about the relative strengths of two different kinds of dissipative
processes (current sheets/ reconnection sites vs. wave particle interactions).
To take the challenge further, the simulators will provide artificial
spacecraft data from the simulations for the observers to analyze.


title:
Dispersive Casimir Pressure Effect from Surface Plasmon Quanta by Quasi
  1D Metal Wires in Ferrite Disks and The Josephson Frequencies and Currents

abstract:
  Ferrites are distinct material for electromagnetic applications due to its
unique spin precession. In this paper, Casimir pressure effect by deploying
magnetically tunable surface plasmon quanta in stratified structure of using
ferrite and metal wires is presented. Previously, oscillating surface plasmon
quanta were successfully included to modify first reflection and first
transmission characteristics. The oscillating surface plasmon quanta in the
modified reflection in such a system, not only does resolve in a typical matter
in metamaterial, but also provide new applications such as creating Casimir
pressure effects through the metamaterial composite shown in this paper. The
Casimir pressure flips from attractive state to repulsive state is referred to
cause mechanism of radiation from surface plasmon quanta. Both Casimir force
analysis and the measured data of radiations indicate us the system develops
quantized states by electric flux induced by ferromagnetic resonance. Quantum
analysis is used to understand the discrete radiations spectra for our
experimental measurement. The discrete radiations are reproduced by using time
dependent Schr\"odinger representation. As a result, we find the Josephson
frequency and Josephson current representations at room temperature and we used
them for extrapolating voltage induced in excited ferrites. Josephson frequency
at X-band is able to differentiate micron volt differences and it allows us to
report the data for voltage induced by ferromagnetic resonance in ferrite at
room temperature. It is understood that the radiation intensity depends on
density of final states and excitation probability when we come to think the
energy matter. It seems possible to create as high as 20mW microwave power
inside waveguide at X-band.


title:
Ultrafast and selective coherent population transfer in four-level atoms
  by a single frequency chirped few-cycle pulse

abstract:
  We report and propose a simple scheme to achieve the ultrafast and selective
population transfer in four-level atoms by utilizing a single frequency chirped
few-cycle pulse. It is demonstrated that the almost complete population may be
transferred to the preselected state of atoms just by manipulating the so
called chirp offset parameter. The robustness of the scheme against the
variation of laser pulse parameters is also investigated. The proposed scheme
may also be useful for the selective population transfer in molecules.


title: Conditions for two-photon interference with coherent pulses

abstract:
  We study the conditions for two-photon classical interference with coherent
pulses. We find that the temporal overlap between optical pulses is not
required for interference However, coherence within the same inputs is found to
be essential for the interference.


title:
Associated Production Evidence against Higgs Impostors and Anomalous
  Couplings

abstract:
  There is still no proof that the new particle $X$ recently discovered by the
ATLAS and CMS Collaborations indeed has spin zero and positive parity, as
confidently expected. We show here that the energy dependence of associated
$W/Z + X$ production would be much less for a $J^P = 0^+$ boson with minimal
couplings, such as the Higgs boson of the Standard Model, than for a spin-two
particle with graviton-like couplings or a spin-zero boson with non-minimal
couplings. The $W/Z + (X \to {\bar b}b)$ signal apparently observed by the CDF
and D0 Collaborations can be used to predict the cross section for the same
signal at the LHC that should be measured under the spin-two and different
spin-zero hypotheses. The spin-two prediction exceeds by an order of magnitude
the upper limits established by the ATLAS and CMS Collaborations, which are
consistent with the minimal $0^+$ prediction, thereby providing {\it secunda
facie} evidence against spin-two Higgs impostors. Similar analyses of energy
dependences provide evidence against $0^-$ impostors, non-minimal scalar boson
couplings, including the best LHC limits on dimension-six operators. Comparing
the LHC vector boson fusion cross sections at 7 and 8 TeV in the centre of mass
provides additional but weaker evidence in favour of the identification of the
$X$ particle as a $J^P = 0^+$ boson with minimal couplings.


title:
Evidence for Cooper Pair Diffraction on the Vortex Lattice of
  Superconducting Niobium

abstract:
  We investigated the Abrikosov vortex lattice (VL) of a pure Niobium single
crystal with the muon spin rotation (\mu SR) technique. Analysis of the \mu SR
data in the framework of the BCS-Gor'kov theory allowed us to determine
microscopic parameters and the limitations of the theory. With decreasing
temperature the field variation around the vortex cores deviates substantially
from the predictions of the Ginzburg-Landau theory and adopts a pronounced
conical shape. This is evidence of partial diffraction of Cooper pairs on the
VL predicted by Delrieu for clean superconductors.


title:
Direct Proof of Security of Wegman-Carter Authentication with Partially
  Known Key

abstract:
  Information-theoretically secure (ITS) authentication is needed in Quantum
Key Distribution (QKD). In this paper, we study security of an ITS
authentication scheme proposed by Wegman & Carter, in the case of partially
known authentication key. This scheme uses a new authentication key in each
authentication attempt, to select a hash function from an Almost Strongly
Universal$_2$ hash function family. The partial knowledge of the attacker is
measured as the trace distance between the authentication key distribution and
the uniform distribution; this is the usual measure in QKD. We provide direct
proofs of security of the scheme, when using partially known key, first in the
information-theoretic setting and then in terms of witness indistinguishability
as used in the Universal Composability (UC) framework. We find that if the
authentication procedure has a failure probability $\epsilon$ and the
authentication key has an $\epsilon'$ trace distance to the uniform, then under
ITS, the adversary's success probability conditioned on an authentic
message-tag pair is only bounded by $\epsilon+|\mT|\epsilon'$, where $|\mT|$ is
the size of the set of tags. Furthermore, the trace distance between the
authentication key distribution and the uniform increases to $|\mT|\epsilon'$
after having seen an authentic message-tag pair. Despite this, we are able to
prove directly that the authenticated channel is indistinguishable from an
(ideal) authentic channel (the desired functionality), except with probability
less than $\epsilon+\epsilon'$. This proves that the scheme is
($\epsilon+\epsilon'$)-UC-secure, without using the composability theorem.


title:
Spontaneous and resonant lifting of the spin blockade in nanowire
  quantum dots

abstract:
  A complete numerical description of the charge and spin dynamics of a
two-electron system confined in narrow nanowire quantum dots under oscillating
electric field is presented in the context of recent electric dipole spin
resonance experiments. We find that the spin-orbit coupling results in lifting
the spin blockade by phonon mediated relaxation provided that the initially
occupied state is close in energy to the ground state. This leads to
suppression of the blockade from the triplet state with spins polarized
parallel to the external magnetic field B. At higher B, after singlet-triplet
ground-state transition a new channel for lifting the Pauli blockade opens
which results in an appearance of additional resonance lines. The calculated
signatures of this transition are consistent with recent experimental results
[S. M. Frolov et al., Phys. Rev. Lett. 109, 236805 (2012)].


title: Phoebe's orbit from ground-based and space-based observations

abstract:
  The ephemeris of Phoebe, the ninth satellite of Saturn, is not very accurate.
Previous dynamical models were usually too simplified, the astrometry is
heterogeneous and, the Saturn's ephemeris itself is an additionnal source of
error. The aim is to improve Phoebe's ephemeris by using a large set of
observations, correcting some systematic errors and updating the dynamical
model. The dynamical model makes use of the most recent ephemeris of planets
and Saturnian satellites. The astrometry of Phoebe is improved by using a
compilation of ground-based and space-based observations and by correcting the
bias in stellar catalogues used for the reduction. We present an accurate
ephemeris of Phoebe with residuals of 0.45 arcsec and with an estimated
accuracy of Phoebe's position of less that 100 km on 1990-2020 period.


title: The Semantic Web takes Wing: Programming Ontologies with Tawny-OWL

abstract:
  The Tawny-OWL library provides a fully-programmatic environment for ontology
building; it enables the use of a rich set of tools for ontology development,
by recasting development as a form of programming. It is built in Clojure - a
modern Lisp dialect, and is backed by the OWL API. Used simply, it has a
similar syntax to OWL Manchester syntax, but it provides arbitrary
extensibility and abstraction. It builds on existing facilities for Clojure,
which provides a rich and modern programming tool chain, for versioning,
distributed development, build, testing and continuous integration. In this
paper, we describe the library, this environment and the its potential
implications for the ontology development process.


title:
Unary FA-presentable binary relations: transitivity and classification
  results

abstract:
  Automatic presentations, also called FA-presentations, were introduced to
extend finite model theory to infinite structures whilst retaining the
solubility of fundamental decision problems. A particular focus of research has
been the classification of those structures of some species that admit
FA-presentations. Whilst some successes have been obtained, this appears to be
a difficult problem in general. A restricted problem, also of significant
interest, is to ask this question for unary FA-presentations: that is,
FA-presentations over a one-letter alphabet. This paper studies unary
FA-presentable binary relations.
  It is proven that transitive closure of a unary FA-presentable binary
relation is itself unary FA-presentable. Characterizations are then given of
unary FA-presentable binary relations, quasi-orders, partial orders,
tournaments, directed trees and forests, undirected trees and forests, and the
orbit structures of unary FA-presentable partial and complete mappings,
injections, surjections, and bijections.


title: Explicit algebraic classification of Kundt geometries in any dimension

abstract:
  We present an algebraic classification, based on the null alignment
properties of the Weyl tensor, of the general Kundt class of spacetimes in
arbitrary dimension for which the non-expanding, non-twisting, shear-free null
direction \boldk is a (multiple) Weyl aligned null direction (WAND). No field
equations are used, so that the results apply not only to Einstein's gravity
and its direct extension to higher dimensions, but also to any metric theory of
gravity which admits the Kundt spacetimes. By an explicit evaluation of the
Weyl tensor in a natural null frame we demonstrate that all Kundt geometries
are of type I(b) or more special, and we derive simple necessary and sufficient
conditions under which \boldk becomes a double, triple or quadruple WAND. All
possible algebraically special types, including the refinement to subtypes, are
identified, namely II(a), II(b), II(c), II(d), III(a), III(b), N, O, II_i,
III_i, D(a), D(b), D(c) and D(d). The corresponding conditions are surprisingly
clear and expressed in an invariant geometric form. Some of them are always
satisfied in four dimensions. To illustrate our classification scheme, we apply
it to the most important subfamilies of the Kundt class, namely the pp-waves,
the VSI spacetimes, and generalization of the Bertotti-Robinson, Nariai, and
Plebanski-Hacyan direct-product spacetimes of any dimension.


Extensive divergence of transcription factor binding in Drosophila
  embryos with highly conserved gene expression


title: A stochastic diffusion process for the Dirichlet distribution

abstract:
  The method of potential solutions of Fokker-Planck equations is used to
develop a transport equation for the joint probability of N coupled stochastic
variables with the Dirichlet distribution as its asymptotic solution. To ensure
a bounded sample space, a coupled nonlinear diffusion process is required: the
Wiener-processes in the equivalent system of stochastic differential equations
are multiplicative with coefficients dependent on all the stochastic variables.
Individual samples of a discrete ensemble, obtained from the stochastic
process, satisfy a unit-sum constraint at all times. The process may be used to
represent realizations of a fluctuating ensemble of N variables subject to a
conservation principle. Similar to the multivariate Wright-Fisher process,
whose invariant is also Dirichlet, the univariate case yields a process whose
invariant is the beta distribution. As a test of the results, Monte-Carlo
simulations are used to evolve numerical ensembles toward the invariant
Dirichlet distribution.


title:
Gyrogroups, the Grouplike Loops in the Service of Hyperbolic Geometry
  and Einstein's Special Theory of Relativity

abstract:
  In this era of an increased interest in loop theory, the Einstein velocity
addition law has fresh resonance. One of the most fascinating aspects of recent
work in Einstein's special theory of relativity is the emergence of special
grouplike loops. The special grouplike loops, known as gyrocommutative
gyrogroups, have thrust the Einstein velocity addition law, which previously
has operated mostly in the shadows, into the spotlight.


title: The Distribution of AGN Covering Factors

abstract:
  We review our knowledge of the most basic properties of the AGN obscuring
region - its location, scale, symmetry, and mean covering factor - and discuss
new evidence on the distribution of covering factors in a sample of ~9000
quasars with WISE, UKIDSS, and SDSS photometry. The obscuring regions of AGN
may be in some ways more complex than we thought - multi-scale, not symmetric,
chaotic - and in some ways simpler - with no dependence on luminosity, and a
covering factor distribution that may be determined by the simplest of
considerations - e.g. random misalignments.


title: Proposed Graphene Nanospaser

abstract:
  We show that graphene monolayer coupled to multi-quantum well system can form
a graphene spaser, which is a coherent quantum generator of surface plasmons in
graphene. The active element of graphene spaser is a multi-quantum well system
with a design similar to the design of an active element of quantum cascade
laser. Under realistic parameters of the multi-quantum well system, the spasing
in graphene monolayer can be achieved at a finite doping of graphene and at a
plasmon frequency, 0.15 eV, close to the typical frequency of intersubband
transitions in multi-quantum well systems.


title: Branes, Weights and Central Charges

abstract:
  We study the properties of half-supersymmetric branes in string theory with
32 supercharges from a purely group-theoretical point of view using the
U-duality symmetry of maximal supergravity and the R-symmetry of the
corresponding supersymmetry algebra. In particular, we show that
half-supersymmetric branes are always associated to the longest weights of the
U-duality representation of the potentials coupling to them. We compare the
features of branes with three or more transverse directions (that we call
"standard" branes) to those with two or less transverse directions (that we
denominate "non-standard" branes). We show why the BPS condition of the
non-standard branes is in general degenerate and for each case we calculate
this degeneracy. We furthermore show how the orbits of multi-charge
configurations of non-standard branes can be calculated and give the U-duality
invariants describing these orbits. We show that different orbits of
non-standard branes can have the same BPS condition.


title: A Pattern Recognition Approach To Secure Cipher Documents

abstract:
  Natural phenomena show that many creatures form large social groups and move
in regular patterns. Previous In this paper, we first propose an efficient
distributed mining algorithm to jointly identify a group of moving objects and
discover their movement patterns in wireless sensor networks. Afterward, we
propose a compression algorithm, called 2P2D, which exploits the obtained group
movement patterns to reduce the amount of delivered data. The compression
algorithm includes a sequence merge and an entropy reduction phases. we
formulate a Hit Item Replacement (HIR) problem and propose a Replace algorithm
that obtains the optimal solution. Moreover, we devise three replacement rules
and derive the maximum compression ratio.


title:
Characterisation and mitigation of beam-induced backgrounds observed in
  the ATLAS detector during the 2011 proton-proton run

abstract:
  This paper presents a summary of beam-induced backgrounds observed in the
ATLAS detector and discusses methods to tag and remove background contaminated
events in data. Trigger-rate based monitoring of beam-related backgrounds is
presented. The correlations of backgrounds with machine conditions, such as
residual pressure in the beam-pipe, are discussed. Results from dedicated
beam-background simulations are shown, and their qualitative agreement with
data is evaluated. Data taken during the passage of unpaired, i.e.
non-colliding, proton bunches is used to obtain background-enriched data
samples. These are used to identify characteristic features of beam-induced
backgrounds, which then are exploited to develop dedicated background tagging
tools. These tools, based on observables in the Pixel detector, the muon
spectrometer and the calorimeters, are described in detail and their
efficiencies are evaluated. Finally an example of an application of these
techniques to a monojet analysis is given, which demonstrates the importance of
such event cleaning techniques for some new physics searches.


title: Superconductivity of topological insulator Bi2Se3 at high pressures

abstract:
  The pressure induced superconductivity and structural evolution for Bi2Se3
single crystal have been studied. The emergence of superconductivity with onset
transition temperature (Tc) about 4.4K is observed around 12GPa. Tc increases
rapidly to the highest 8.5K at 16GPa, decreases to 6.5K at 21GPa, then keep
almost constant. It is found that Tc versus pressure is closely related to the
carrier density which increases by more than two orders of magnitude from 2GPa
to 23GPa. High pressure synchrotron radiation measurements reveal structure
transitions occur around 12GPa, 20GPa, and above 29GPa, respectively. A phase
diagram of superconductivity versus pressure is obtained.


title:
Parallel pumping of magnetic vortex gyrations in spin-torque
  nano-oscillators

abstract:
  We experimentally demonstrate that large magnetic vortex oscillations can be
parametrically excited in a magnetic tunnel junction by the injection of
radio-frequency (rf) currents at twice the natural frequency of the gyrotropic
vortex core motion. The mechanism of excitation is based on the parallel
pumping of vortex motion by the rf orthoradial field generated by the injected
current. Theoretical analysis shows that experimental results can be
interpreted as the manifestation of parametric amplification when rf current is
small, and of parametric instability when rf current is above a certain
threshold. By taking into account the energy nonlinearities, we succeed to
describe the amplitude saturation of vortex oscillations as well as the
coexistence of stable regimes.


title:
Performance of the Hamamatsu R11410 Photomultiplier Tube in cryogenic
  Xenon Environments

abstract:
  The Hamamatsu R11410 photomultiplier, a tube of 3" diameter and with a very
low intrinsic radioactivity, is an interesting light sensor candidate for
future experiments using liquid xenon (LXe) as target for direct dark matter
searches. We have performed several experiments with the R11410 with the goal
of testing its performance in environments similar to a dark matter detector
setup. In particular, we examined its long-term behavior and stability in LXe
and its response in various electric field configurations.


title: All Six Planets Known to Orbit Kepler-11 Have Low Densities

abstract:
  The Kepler-11 planetary system contains six transiting planets ranging in
size from 1.8 to 4.2 times the radius of Earth. Five of these planets orbit in
a tightly-packed configuration with periods between 10 and 47 days. We perform
a dynamical analysis of the system based upon transit timing variations
observed in more than three years of \ik photometric data. Stellar parameters
are derived using a combination of spectral classification and constraints on
the star's density derived from transit profiles together with planetary
eccentricity vectors provided by our dynamical study. Combining masses of the
planets relative to the star from our dynamical study and radii of the planets
relative to the star from transit depths together with deduced stellar
properties yields measurements of the radii of all six planets, masses of the
five inner planets, and an upper bound to the mass of the outermost planet,
whose orbital period is 118 days. We find mass-radius combinations for all six
planets that imply that substantial fractions of their volumes are occupied by
constituents that are less dense than rock. The Kepler-11 system contains the
lowest mass exoplanets for which both mass and radius have been measured.


title: Surveying Extended GMSB Models with mh=125 GeV

abstract:
  In order to achieve maximal stop mixing and m_h=125 GeV, we consider
extensions of minimal GMSB that include marginal MSSM-messenger superpotential
interactions. Using a new approach to analytic continuation in superspace, we
derive general formulas for the soft masses in the presence of such
interactions, correctly taking into account the role of MSSM-messenger mixing
in a general framework for the first time. We classify and catalog all possible
such interactions consistent with perturbative SU(5) unification, and we survey
the impact of turning on one interaction at a time, from the point of view of
fine tuning, spectrum and phenomenology. We find that the best models are
fine-tuned to the sub-percent level and are accessible at the 14 TeV LHC. We
highlight potential search strategies that can probe the characteristic spectra
of these models.


title: Wireless Network-Coded Multi-Way Relaying Using Latin Hyper-Cubes

abstract:
  Physical layer network-coding for the $n$-way wireless relaying scenario is
dealt with, where each of the $n$ user nodes $X_1,$ $X_2,...,X_n$ wishes to
communicate its messages to all the other $(n-1)$ nodes with the help of the
relay node R. The given scheme, based on the denoise-and-forward scheme
proposed for two-way relaying by Popovski et al. in \cite{PoY1}, employs two
phases: Multiple Access (MA) phase and Broadcast (BC) phase with each phase
utilizing one channel use and hence totally two channel uses. Physical layer
network-coding using the denoise-and-forward scheme was done for the two-way
relaying scenario in\cite{KPT}, for three-way relaying scenario in \cite{SVR},
and for four-way relaying scenario in \cite{ShR}. This paper employs
denoise-and-forward scheme for physical layer network coding of the $n$-way
relaying scenario illustrating with the help of the case $n = 5$ not dealt with
so far. It is observed that adaptively changing the network coding map used at
the relay according to the channel conditions reduces the impact of multiple
access interference which occurs at the relay during the MA phase. These
network coding maps are chosen so that they satisfy a requirement called
\textit{exclusive law}. We show that when the $n$ users transmit points from
the same $M$-PSK $(M=2^{\lambda})$ constellation, every such network coding map
that satisfies the exclusive law can be represented by a $n$-fold Latin
Hyper-Cube of side $M$. The singular fade subspaces resulting from the scheme
are described and enumerated for general values of $n$ and $M$ and are
classified based on their removability in the given scenario. A network code
map to be used by the relay for the BC phase aiming at reducing the effect of
interference at the MA stage is obtained.


title:
Thermodynamics and phase transition of the O(N) model from the two-loop
  Phi-derivable approximation

abstract:
  We discuss the thermodynamics of the O(N) model across the corresponding
phase transition using the two-loop Phi-derivable approximation of the
effective potential and compare our results to those obtained in the literature
within the Hartree-Fock approximation. In particular, we find that in the
chiral limit the transition is of the second order, whereas it was found to be
of the first order in the Hartree-Fock case. These features are manifest at the
level of the thermodynamical observables. We also compute the thermal sigma and
pion masses from the curvature of the effective potential. In the chiral limit,
this guarantees that the Goldstone's theorem is obeyed in the broken phase. A
realistic parametrization of the model in the N=4 case, based on the vacuum
values of the curvature masses, shows that a sigma mass of around 450 MeV can
be obtained. The equations are renormalized after extending our previous
results for the N=1 case by means of the general procedure described in [J.
Berges et al., Annals Phys. 320, 344-398 (2005)]. When restricted to the
Hartree-Fock approximation, our approach reveals that certain problems raised
in the literature concerning the renormalization are completely lifted.
Finally, we introduce a new type of Phi-derivable approximation in which the
gap equation is not solved at the same level of accuracy as the accuracy at
which the potential is computed. We discuss the consistency and applicability
of these types of "hybrid" approximations and illustrate them in the two-loop
case by showing that the corresponding effective potential is renormalizable
and that the transition remains of the second order.


title: Network Transfer Entropy and Metric Space for Causality Inference

abstract:
  A measure is derived to quantify directed information transfer between pairs
of vertices in a weighted network, over paths of a specified maximal length.
Our approach employs a general, probabilistic model of network traffic, from
which the informational distance between dynamics on two weighted networks can
be naturally expressed as a Jensen Shannon Divergence (JSD). Our network
transfer entropy measure is shown to be able to distinguish and quantify causal
relationships between network elements, in applications to simple synthetic
networks and a biological signalling network. We conclude with a theoretical
extension of our framework, in which the square root of the JSD induces a
metric on the space of dynamics on weighted networks. We prove a convergence
criterion, demonstrating that a form of convergence in the structure of
weighted networks in a family of matrix metric spaces implies convergence of
their dynamics with respect to the square root JSD metric.


title:
A first-order secular theory for the post-Newtonian two-body problem
  with spin -- I: The restricted case

abstract:
  We revisit the relativistic restricted two-body problem with spin employing a
perturbation scheme based on Lie series. Starting from a post-Newtonian
expansion of the field equations, we develop a first-order secular theory that
reproduces well-known relativistic effects such as the precession of the
pericentre and the Lense-Thirring and geodetic effects. Additionally, our
theory takes into full account the complex interplay between the various
relativistic effects, and provides a new explicit solution of the averaged
equations of motion in terms of elliptic functions. Our analysis reveals the
presence of particular configurations for which non-periodical behaviour can
arise. The application of our results to real astrodynamical systems (such as
Mercury-like and pulsar planets) highlights the contribution of relativistic
effects to the long-term evolution of the spin and orbit of the secondary body.


title:
Generation of 'Super-Ponderomotive' Electrons due to a non-Wakefield
  interaction between a Laser Pulse and a Longitudinal Electric Field

abstract:
  It is shown that electrons with momenta exceeding the `free electron' limit
of $m_eca_0^2/2$ can be produced when a laser pulse and a longitudinal electric
field interact with an electron via a non-wakefield mechanism. The mechanism
consists of two stages: the reduction of the electron dephasing rate
$\gamma-p_x/m_ec$ by an accelerating region of electric field and electron
acceleration by the laser via the Lorentz force. This mechanism can, in
principle, produce electrons that have longtudinal momenta that is a
significant multiple of $m_eca_0^2/2$. 2D PIC simulations of a relatively
simple laser-plasma interaction indicate that the generation of
super-ponderomotive electrons is strongly affected by this `anti-dephasing'
mechanism.


title: Equidistribution of values of linear forms on quadratic surfaces

abstract:
  In this paper we investigate the distribution of the set of values of a
linear map at integer points on a quadratic surface. In particular, it is shown
that subject to certain algebraic conditions, this set is equidistributed. This
can be thought of as a quantitative version of the main result from
[2011arXiv1111.4428S]. The methods used are based on those developed by A.
Eskin, S. Mozes and G. Margulis in [MR1609447]. Specifically, they rely on
equidistribution properties of unipotent flows.


title: Common fixed points for Banach-Caristi contractive pairs

abstract:
  Further extensions are given for the common fixed point statement in Dien [J.
Math. Anal. Appl., 187 (1994), 76-90], involving Banach-Caristi contractive
pairs.


title: Charmonium production in antiproton-nucleus reactions at low energies

abstract:
  The J/\Psi(1S) and \Psi'(2S) production near threshold in antiproton-nucleus
reactions is calculated on the basis of the Glauber model. The model takes into
account the antiproton (pre)absorption, proton Fermi motion, and charmonium
formation length. We confirm earlier prediction that the charmonium production
in $\bar pA$ collisions at $p_{lab}=3-10$ GeV/c is not influenced by formation
length effects and is very well suited to determine the genuine
charmonium-nucleon dissociation cross sections. The comparison is performed
with the J/\Psi photoproduction at high energies, where formation length
effects play a very important role. However, we demonstrate that the detailed
structure of the proton and neutron density profiles has to be taken into
account, if one wants to extract information on the J/\Psi N dissociation cross
section from J/\Psi transparency ratios. These studies are relevant for the
upcoming PANDA experiment at FAIR.


title: Optimal investment and price dependence in a semi-static market

abstract:
  This paper studies the problem of maximizing expected utility from terminal
wealth in a semi-static market composed of derivative securities, which we
assume can be traded only at time zero, and of stocks, which can be traded
continuously in time and are modeled as locally-bounded semi-martingales.
  Using a general utility function defined on the positive real line, we first
study existence and uniqueness of the solution, and then we consider the
dependence of the outputs of the utility maximization problem on the price of
the derivatives, investigating not only stability but also differentiability,
monotonicity, convexity and limiting properties.


title:
Relative fixed-width stopping rules for Markov chain Monte Carlo
  simulations

abstract:
  Markov chain Monte Carlo (MCMC) simulations are commonly employed for
estimating features of a target distribution, particularly for Bayesian
inference. A fundamental challenge is determining when these simulations should
stop. We consider a sequential stopping rule that terminates the simulation
when the width of a confidence interval is sufficiently small relative to the
size of the target parameter. Specifically, we propose relative magnitude and
relative standard deviation stopping rules in the context of MCMC. In each
setting, we develop sufficient conditions for asymptotic validity, that is
conditions to ensure the simulation will terminate with probability one and the
resulting confidence intervals will have the proper coverage probability. Our
results are applicable in a wide variety of MCMC estimation settings, such as
expectation, quantile, or simultaneous multivariate estimation. Finally, we
investigate the finite sample properties through a variety of examples and
provide some recommendations to practitioners.


title: Growth in groups: ideas and perspectives

abstract:
  This is a survey of methods developed in the last few years to prove results
on growth in non-commutative groups. These techniques have their roots in both
additive combinatorics and group theory, as well as other fields. We discuss
linear algebraic groups, with SL_2(Z/pZ) as the basic example, as well as
permutation groups. The emphasis lies on the ideas behind the methods.


title: The Subelliptic $\infty$-Laplace System on Carnot-Carath\'eodory Spaces

abstract:
  Given a Carnot-Carath\'eodory space $\Om \sub \R^n$ with associated vector
fields $X=\{X_1,...,X_m\}$, we derive the subelliptic $\infty$-Laplace system
for mappings $u : \Om \larrow \R^N$, which reads \[ \label{1} \De^X_\infty u \,
:=\, \Big(Xu \ot Xu + \|Xu\|^2 [Xu]^\bot \ot I \Big) : XX u\, = \, 0 \tag{1} \]
in the limit of the subelliptic $p$-Laplacian as $p\ri \infty$. Here $Xu$ is
the horizontal gradient and $[Xu]^\bot$ is the projection on its nullspace.
Next, we identify the Variational Principle characterizing \eqref{1}, which is
the "Euler-Lagrange PDE" of the supremal functional \[ \label{2}
E_\infty(u,\Om)\ := \ \|Xu\|_{L^\infty(\Om)} \tag{2} \] for an appropriately
defined notion of \emph{Horizontally $\infty$-Minimal Mappings}. We also
establish a maximum principle for $\|Xu\|$ for solutions to \eqref{1}. These
results extend previous work of the author \cite{K1, K2} on vector-valued
Calculus of Variations in $L^\infty$ from the Euclidean to the subelliptic
setting.


title:
The canonical trace and the noncommutative residue on the noncommutative
  torus

abstract:
  Using a global symbol calculus for pseudodifferential operators on tori, we
build a canonical trace on classical pseudodifferential operators on
noncommutative tori in terms of a canonical discrete sum on the underlying
toroidal symbols. We characterise the canonical trace on operators on the
noncommutative torus as well as its underlying canonical discrete sum on
symbols of fixed (resp.\ any) non--integer order. On the grounds of this
uniqueness result, we prove that in the commutative setup, this canonical trace
on the noncommutative torus reduces to Kontsevich and Vishik's canonical trace
which is thereby identified with a discrete sum. A similar characterisation for
the noncommutative residue on noncommutative tori as the unique trace which
vanishes on trace--class operators generalises Fathizadeh and Wong's
characterisation in so far as it includes the case of operators of fixed
integer order. By means of the canonical trace, we derive defect formulae for
regularized traces. The conformal invariance of the $\zeta$--function at zero
of the Laplacian on the noncommutative torus is then a straightforward
consequence.


title: Large Tensor-to-Scalar Ratio in Small-Field Inflation

abstract:
  We show that density perturbations seeded by the inflaton can be suppressed
when having additional light degrees of freedom contributing to the production
of perturbations. The inflaton fluctuations affect the light field dynamics by
modulating the length of the inflationary period, hence produce additional
density perturbations in the post-inflationary era. Such perturbations can
cancel those generated during inflation as both originate from the same
inflaton fluctuations. This allows production of large gravitational waves from
small-field inflation, which is normally forbidden by the Lyth bound on the
inflaton field excursion. We also find that the field bound is taken over by
the light scalar when the inflaton-induced perturbations are suppressed, thus
present a generalized form of the Lyth bound that applies to the total field
space.


title: Thermocapillary motion

abstract:
  When the liquid has a free interface and is heated nonuniformly then besides
the gravitational convection a different motion appears. This kind of a motion
is originated because of a gradient of the surface tension over the liquid
interface. It is suggested to call it a thermocapillary motion in analogy with
an electrocapillary motion. The present paper develops a theory of
thermocapillary motion for two distinct geometries: a liquid layer and a liquid
drop suspended in another viscous medium. For both geometries, assuming the
non-deformable interfaces, the velocity profiles are found and feasibility of
the assumptions made is discussed. To our knowledge, this is a first ether
attempt of theoretical consideration of the thermocapillary motion (KM & SB).


title:
Observation of electronic inhomogeneity and charge density wave in a
  bilayer La$_{1.36}$Sr$_{1.64}$Mn$_2$O$_7$ single crystal

abstract:
  We employed a scanning tunneling microscope to image the (001) surface
topography and local density of states (LDOS) in
La$_{2-2x}$Sr$_{1+2x}$Mn$_2$O$_7$ (x=0.32, LSMO) single crystals below the
Curie temperature (T$_C$ = 120 K). The LDOS maps revealed a stripe-like
modulation propagating along the tetragonal a axis with a wavelength of about
1.6 \AA, which is indicative of a charge density wave (CDW). The observed CDW
in the x=0.32 sample is far from the Fermi surface nesting instability as
compared with the data of angle resolved photoemission spectroscopy in an
x=0.40 sample. The stripe model developed previously for cuprates can explain
the observed CDW in our LSMO sample, indicating that competing interactions
between localized and itinerant phases are the origin of the spatial
modulations present intrinsically in cuprates and manganites.


title:
Temperature dependent polarization of the thermal radiation emitted by
  thin, hot tungsten wires

abstract:
  We report measurements of the temperature $T $ dependence of the linear
polarization $\langle P\rangle $ of the thermal radiation emitted by thin,
incandescent tungsten wires. We investigated an interval ranging from a little
above room temperature up to melting, $T_m\approx 3700\,$K. These are the first
measurements in such wide a range. We found that $\langle P\rangle $ decreases
with increasing $T.$ We obtained a satisfactory agreement with the theoretical
predictions based on the Kirchhoff's law by using a Drude-type formula for the
optical properties of tungsten. The validity of such formula is assessed in
literature for $T\leq 2400 \,$K and for wavelengths in the range from visible
up to $\lambda\approx 2.6\,\mu$m. We have extended the range of validity of
this formula for $T$ up to $T_m$ and for $\lambda$ up to $\approx 12\,\mu$m.


title:
Divergent Precursors of the Mott-Hubbard Transition at the Two-Particle
  Level

abstract:
  Identifying the fingerprints of the Mott-Hubbard metal-insulator transition
may be quite elusive in correlated metallic systems if the analysis is limited
to the single particle level. However, our dynamical mean-field calculations
demonstrate that the situation changes completely if the frequency dependence
of the two-particle vertex functions is considered: The first non-perturbative
precursors of the Mott physics are unambiguously identified well inside the
metallic regime by the divergence of the local Bethe-Salpeter equation in the
charge channel. At low temperatures this occurs in the region where incoherent
high-energy features emerge in the spectral function, while at high
temperatures it is traceable up to the atomic-limit.


title: A Coding-Theoretic Application of Baranyai's Theorem

abstract:
  Baranyai's theorem is a well-known theorem in the theory of hypergraphs. A
corollary of this theorem says that one can partition the family of all
$u$-subsets of an $n$-element set into ${n-1\choose u-1}$ sub-families such
that each sub-family form a partition of the $n$-element set, where $n$ is
divisible by $u$. In this paper, we present a coding-theoretic application of
Baranyai's theorem (or equivalently, the corollary). More precisely, we propose
the first purely combinatorial construction of locally decodable codes. Locally
decodable codes are error-correcting codes that allow the recovery of any
message bit by looking at only a few bits of the codeword. Such codes have
attracted a lot of attention in recent years. We stress that our construction
does not improve the parameters of known constructions. What makes it
interesting is the underlying combinatorial techniques and their potential in
future applications.


title:
Testing the rotating hot spot model using X-ray burst oscillations from
  4U 1636-536

abstract:
  Precise and accurate measurements of neutron star masses and radii would
provide valuable information about the still uncertain properties of cold
matter at supranuclear densities. One promising approach to making such
measurements involves analysis of the X-ray flux oscillations often seen during
thermonuclear (type 1) X-ray bursts. These oscillations are almost certainly
produced by emission from hotter regions on the stellar surface modulated by
the rotation of the star. One consequence of the rotation is that the
oscillation should appear earlier at higher photon energies than at lower
energies. Ford (1999) found compelling evidence for such a hard lead in the
tail oscillations of one type 1 burst from Aql X-1. We have therefore analyzed
individually the oscillations observed in the tails of the four type 1 bursts
from 4U 1636-536 that, when averaged, provided the strongest evidence for a
soft lead in the analysis by Muno et al. (2003). We have also analyzed the
oscillation observed during the superburst from this star. We find that the
data from these five bursts, treated both individually and jointly, are fully
consistent with a rotating hot spot model. Unfortunately, the uncertainties in
these data are too large to provide interesting constraints on the mass and
radius of this star.


title:
Galactic Spiral Arms: Structure and Dynamics Given by an Equation of
  Motion

abstract:
  Using an equation of motion for a self-gravitating filament, we show how
galactic spiral arms might be created and sustained. We find that the
combination of differential rotation of the galactic disk and the self-gravity
of the arm (as given by the equation) leads to a rotating spiral structure.
Moreover, using this analysis, we then find a second differential equation that
explicitly relates this spiral structure to the rotation curve of the galaxy --
it connects several factors, including spiral shape and pattern speed. We also
describe a simple many-body numerical experiment that supports our approach.
The findings are with consistent with observational evidence concerning arm
structure and rotation curves, including leading arm structures.


title: Frames of multi-windowed exponentials on subsets of ${\mathbb R}^d$

abstract:
  Given discrete subsets $\Lambda_j\subset {\Bbb R}^d$, $j=1,...,q$, consider
the set of windowed exponentials $\bigcup_{j=1}^{q}\{g_j(x)e^{2\pi i
<\lambda,x>}: \lambda\in\Lambda_j\}$ on $L^2(\Omega)$. We show that a necessary
and sufficient condition for the windows $g_j$ to form a frame of windowed
exponentials for $L^2(\Omega)$ with some $\Lambda_j$ is that $m\leq \max_{j\in
J}|g_j|\leq M$ almost everywhere on $\Omega$ for some subset $J$ of $\{1,...,
q\}$. If $\Omega$ is unbounded, we show that there is no frame of windowed
exponentials if the Lebesgue measure of $\Omega$ is infinite. If $\Omega$ is
unbounded but of finite measure, we give a sufficient condition for the
existence of Fourier frames on $L^2(\Omega)$. At the same time, we also
construct examples of unbounded sets with finite measure that have no tight
exponential frame.


title: Non-geometric fluxes versus (non)-geometry

abstract:
  Non-geometry has been introduced when considering a new type of string
backgrounds, for which stringy symmetries serve as transition functions between
patches of the target space. Then, some terms in the potential of
four-dimensional gauged supergravities, generated by so-called non-geometric
fluxes, have been argued to find a higher-dimensional origin in these
backgrounds, even if a standard compactification on those cannot be made. We
present here recent results clarifying the relation between these two settings.
Thanks to a field redefinition, we reformulate the NSNS Lagrangian in such a
way that the non-geometric fluxes appear in ten dimensions. In addition, if an
NSNS field configuration is non-geometric, its reformulation in terms of the
new fields can restore a standard geometry. A dimensional reduction is then
possible, and leads to the non-geometric terms in the four-dimensional
potential. Reformulating similarly doubled field theory, we get a better
understanding of the role of the non-geometric fluxes, and rewrite the
Lagrangian in a manifestly diffeomorphism-covariant manner. We finally discuss
the relevance of the field redefinition and the non-geometric fluxes when
studying the non-commutativity of string coordinates.


title: Quotients of non-classical flag domains are not algebraic

abstract:
  A flag domain D = G/V for G a simple real non-compact group G with compact
Cartan subgroup is non-classical if it does not fiber holomorphically or
anti-holomorphically over a Hermitian symmetric space. We prove that any two
points in a non-classical domain D can be joined by a finite chain of compact
subvarieties of D. Then we prove that for F an infinite, finitely generated
discrete subgroup of G, the analytic space F\D does not have an algebraic
structure.


title: Flexibility of Schubert classes

abstract:
  In this note, we discuss the flexibility of Schubert classes in homogeneous
varieties. We give several constructions for representing multiples of a
Schubert class by irreducible subvarieties. We sharpen [R, Theorem 3.1] by
proving that every positive multiple of an obstructed class in a cominuscule
homogeneous variety can be represented by an irreducible subvariety.


title: WASP-80b: a gas giant transiting a cool dwarf

abstract:
  We report the discovery of a planet transiting the star WASP-80 (1SWASP
J201240.26-020838.2; 2MASS J20124017-0208391; TYC 5165-481-1; BPM 80815;
V=11.9, K=8.4). Our analysis shows this is a 0.55 +/- 0.04 Mjup, 0.95 +/- 0.03
Rjup gas giant on a circular 3.07 day orbit around a star with a spectral type
between K7V and M0V. This system produces one of the largest transit depths so
far reported, making it a worthwhile target for transmission spectroscopy. We
find a large discrepancy between the v sin i inferred from stellar line
broadening and the observed amplitude of the Rossiter-McLaughlin effect. This
can be understood either by an orbital plane nearly perpendicular to the
stellar spin or by an additional, unaccounted for source of broadening.


title:
Measuring Transit Signal Recovery in the Kepler Pipeline I: Individual
  Events

abstract:
  The Kepler Mission was designed to measure the frequency of Earth-size
planets in the habitable zone of Sun-like stars. A crucial component for
recovering the underlying planet population from a sample of detected planets
is understanding the completeness of that sample - what fraction of the planets
that could have been discovered in a given data set were actually detected.
Here we outline the information required to determine the sample completeness,
and describe an experiment to address a specific aspect of that question, which
is the issue of transit signal recovery. We investigate the extent to which the
Kepler pipeline preserves individual transit signals by injecting simulated
transits into the pixel-level data, processing the modified pixels through the
pipeline, and comparing the measured transit signal-to-noise ratio (SNR) to
that expected without perturbation by the pipeline. We inject simulated transit
signals across the full focal plane for a set of observations of length 89
days. On average, we find that the SNR of the injected signal is recovered at
MS = 0.9973(+/-0.0012)xBS-0.0151(+/-0.0049), where MS is the measured SNR and
BS is the baseline, or expected, SNR. The 1{\sigma} width of the distribution
around this correlation is +/-2.64%. We discuss the pipeline processes that
cause the measured SNR to deviate significantly from the baseline SNR; these
are primarily the handling of data adjacent to spacecraft re-pointings and the
removal of harmonics prior to the measurement of the SNR. Finally we outline
the further work required to characterise the completeness of the Kepler
pipeline.


title: A Brief History of Excitable Map-Based Neurons and Neural Networks

abstract:
  This review gives a short historical account of the excitable maps approach
for modeling neurons and neuronal networks. Some early models, due to Pasemann
(1993), Chialvo (1995) and Kinouchi and Tragtenberg (1996), are compared with
more recent proposals by Rulkov (2002) and Izhikevich (2003). We also review
map-based schemes for electrical and chemical synapses and some recent findings
as critical avalanches in map-based neural networks. We conclude with
suggestions for further work in this area like more efficient maps,
compartmental modeling and close dynamical comparison with conductance-based
models.


title:
Blow-up scenarios for 3D NSE exhibiting sub-criticality with respect to
  the scaling of one-dimensional local sparseness

abstract:
  It is shown that, if the vorticity magnitude associated with a (presumed
singular) three-dimensional incompressible Navier-Stokes flow blows-up in a
manner exhibiting certain {\em time dependent local structure}, then {\em time
independent} estimates on the $L^1$ norm of $|\omega|\log\sqrt{1+ |\omega|^2}$
follow. The implication is that the volume of the region of high vorticity
decays at a rate of greater order than a rate connected to the critical scaling
of one-dimensional local sparseness and, consequently, the solution becomes
sub-critical.


title: Rapid diffusion of electrons in GaMnAs

abstract:
  We report ultrafast transient-grating measurements, above and below the Curie
temperature, of the dilute ferromagnetic semiconductor (Ga,Mn)As containing 6%
Mn. At 80 K (15 K), we observe that photoexcited electrons in the conduction
band have a lifetime of 8 ps (5 ps) and diffuse at about 70 cm2/s (60 cm2/s).
Such rapid diffusion requires either an electronic mobility exceeding 7,700
cm2/Vs or a conduction-band effective mass less than half the GaAs value. Our
data suggest that neither the scattering rate nor the effective mass of the
(Ga,Mn)As conduction band differs significantly from that of GaAs.


title:
Linear-scaling time-dependent density-functional theory in the linear
  response formalism

abstract:
  We present an implementation of time-dependent density-functional theory
(TDDFT) in the linear response formalism enabling the calculation of low energy
optical absorption spectra for large molecules and nanostructures. The method
avoids any explicit reference to canonical representations of either occupied
or virtual Kohn-Sham states and thus achieves linear-scaling computational
effort with system size. In contrast to conventional localised orbital
formulations, where a single set of localised functions is used to span the
occupied and unoccupied state manifold, we make use of two sets of in situ
optimised localised orbitals, one for the occupied and one for the unoccupied
space. This double representation approach avoids known problems of spanning
the space of unoccupied Kohn-Sham states with a minimal set of localised
orbitals optimised for the occupied space, while the in situ optimisation
procedure allows for efficient calculations with a minimal number of functions.
The method is applied to a number of medium sized organic molecules and a good
agreement with traditional TDDFT methods is observed. Furthermore, linear
scaling of computational cost with system size is demonstrated on a system of
carbon nanotubes.


title: On the Granular Stress-Geometry Equation

abstract:
  Using discrete calculus, we derive the missing stress-geometry equation for
rigid granular materials in two dimensions, in the mean-field approximation. We
show that (i) the equation imposes that the voids cannot carry stress, (ii)
stress transmission is generically elliptic and has a quantitative relation to
anisotropic elasticity, and (iii) the packing fabric plays an essential role.


title: Diffusion of degenerate minority carriers in a p-type semiconductor

abstract:
  We report ultrafast transient-grating experiments on heavily p-type InP at 15
K. Our measurement reveals the dynamics and diffusion of photoexcited electrons
and holes as a function of their density n in the range 2E16 to 6E17 cm-3.
After the first few picoseconds the grating decays primarily due to ambipolar
diffusion. While at low density we observe a regime in which the ambipolar
diffusion is electron-dominated and increases rapidly with n, at high n it
appears to saturate at 34 cm2/s. We present a simple calculation that
reproduces the main results of our measurements as well as of previously
published measurements that had shown diffusion to be a flat or decreasing
function of n. By accounting for effect of density on charge susceptibility we
show that, in p-type semiconductors, the regime we observe of increasing
ambipolar diffusion is unique to heavy doping and low temperature, where both
the holes and electrons are degenerate; in this regime the electronic and
ambipolar diffusion are nearly equal. The saturation is identified as a
crossover to ambipolar diffusion dominated by the majority carriers, the holes.
At short times the transient-grating signal rises gradually. This rise reveals
cooling of hot electrons and, at high photocarrier density, allows us to
measure ambipolar diffusion of 110 cm2/s in the hot-carrier regime.


title: Covering Paths for Planar Point Sets

abstract:
  Given $n$ points in the plane, a \emph{covering path} is a polygonal path
that visits all the points. If no three points are collinear, every covering
path requires at least $n/2$ segments, and $n-1$ straight line segments
obviously suffice even if the covering path is required to be noncrossing. We
show that every set of $n$ points in the plane admits a (possibly self-crossi
ng) covering path consisting of $n/2 +O(n/\log{n})$ straight line segments. If
the path is required to be noncrossing, we prove that $(1-\eps)n$ straight line
segments suffice for a small constant $\eps>0$, and we exhibit $n$-element
point sets that require at least $5n/9 -O(1)$ segments in every such path.
Further, the analogous question for noncrossing \emph{covering trees} is
considered and similar bounds are obtained. Finally, it is shown that computing
a noncrossing covering path for $n$ points in the plane requires $\Omega(n
\log{n})$ time in the worst case.


title: Local and global dynamics of warped astrophysical discs

abstract:
  Astrophysical discs are warped whenever a misalignment is present in the
system, or when a flat disc is made unstable by external forces. The evolution
of the shape and mass distribution of a warped disc is driven not only by
external influences but also by an internal torque, which transports angular
momentum through the disc. This torque depends on internal flows driven by the
oscillating pressure gradient associated with the warp, and on physical
processes operating on smaller scales, which may include instability and
turbulence. We introduce a local model for the detailed study of warped discs.
Starting from the shearing sheet of Goldreich & Lynden-Bell, we impose the
oscillating geometry of the orbital plane by means of a coordinate
transformation. This warped shearing sheet (or box) is suitable for analytical
and computational treatments of fluid dynamics, magnetohydrodynamics, etc., and
it can be used to compute the internal torque that drives the large-scale
evolution of the disc. The simplest hydrodynamic states in the local model are
horizontally uniform laminar flows that oscillate at the orbital frequency.
These correspond to the nonlinear solutions for warped discs found in previous
work by Ogilvie, and we present an alternative derivation and generalization of
that theory. In a companion paper we show that these laminar flows are often
linearly unstable, especially if the disc is nearly Keplerian and of low
viscosity. The local model can be used in future work to determine the
nonlinear outcome of the hydrodynamic instability of warped discs, and its
interaction with others such as the magnetorotational instability.


title: Hydrodynamic instability in warped astrophysical discs

abstract:
  Warped astrophysical discs are usually treated as laminar viscous flows,
which have anomalous properties when the disc is nearly Keplerian and the
viscosity is small: fast horizontal shearing motions and large torques are
generated, which cause the warp to evolve rapidly, in some cases at a rate that
is inversely proportional to the viscosity. However, these flows are often
subject to a linear hydrodynamic instability, which may produce small-scale
turbulence and modify the large-scale dynamics of the disc. We use a warped
shearing sheet to compute the oscillatory laminar flows in a warped disc and to
analyse their linear stability by the Floquet method. We find widespread
hydrodynamic instability deriving from the parametric resonance of inertial
waves. Even very small, unobservable warps in nearly Keplerian discs of low
viscosity can be expected to generate hydrodynamic turbulence, or at least wave
activity, by this mechanism.


title: A two-dimensional mixing length theory of convective transport

abstract:
  The helioseismic observations of the internal rotation profile of the Sun
raise questions about the two-dimensional (2D) nature of the transport of
angular momentum in stars. Here we derive a convective prescription for
axisymmetric (2D) stellar evolution models. We describe the small scale motions
by a spectrum of unstable linear modes in a Boussinesq fluid. Our saturation
prescription makes use of the angular dependence of the linear dispersion
relation to estimate the anisotropy of convective velocities. We are then able
to provide closed form expressions for the thermal and angular momentum fluxes
with only one free parameter, the mixing length.
  We illustrate our prescription for slow rotation, to first order in the
rotation rate. In this limit, the thermodynamical variables are spherically
symetric, while the angular momentum depends both on radius and latitude. We
obtain a closed set of equations for stellar evolution, with a self-consistent
description for the transport of angular momentum in convective regions. We
derive the linear coefficients which link the angular momentum flux to the
rotation rate ($\Lambda$- effect) and its gradient ($\alpha$-effect). We
compare our results to former relevant numerical work.


title: Elimination for generic sparse polynomial systems

abstract:
  We present a new probabilistic symbolic algorithm that, given a variety
defined in an n-dimensional affine space by a generic sparse system with fixed
supports, computes the Zariski closure of its projection to an l-dimensional
coordinate affine space with l < n. The complexity of the algorithm depends
polynomially on combinatorial invariants associated to the supports.


title: Compact fuzzy soft spaces

abstract:
  In this article, by using basic properties of fuzzy soft topology we defined
fuzzy soft compactness. We also introduced some basic definitions and theorems
of the concept.


title:
Maximal Information Divergence from Statistical Models defined by Neural
  Networks

abstract:
  We review recent results about the maximal values of the Kullback-Leibler
information divergence from statistical models defined by neural networks,
including naive Bayes models, restricted Boltzmann machines, deep belief
networks, and various classes of exponential families. We illustrate approaches
to compute the maximal divergence from a given model starting from simple sub-
or super-models. We give a new result for deep and narrow belief networks with
finite-valued units.