title:
The Hierarchical Nature of the Spin Alignment of Dark Matter Haloes in
  Filaments

abstract:
  Dark matter haloes in cosmological filaments and walls have their spin vector
aligned (in average) with their host structure. While haloes in walls are
aligned with the plane of the wall independently of their mass, haloes in
filaments present a mass dependent two-regime orientation. Here we show that
the transition mass determining the change in the alignment regime (from
parallel to perpendicular) depends on the hierarchical level in which the halo
is located, reflecting the hierarchical nature of the Cosmic Web. By explicitly
exposing this hierarchy we are able to identify the contributions of different
components of the filament network to the spin alignment signal. We discuss a
unifying picture to describe the alignment of haloes in filaments and walls
consistent with previous results and our findings based on a two-phase angular
momentum acquisition, first via tidal torquening and later via anisotropic mass
accretion. The hierarchical identification and characterization of cosmic
structures was done with a new implementation of the Multiscale Morphology
Filter. The MMF-2 (introduced here) represents a significant improvement over
its predecessor in terms of robustness and by explicitly describing the
hierarchical relations between the elements of the Cosmic Web.


title: Alexander Duality for Parametrized Homology

abstract:
  This paper extends Alexander duality to the setting of parametrized homology.
Let X with be a compact subset of R^n x R (n \geq 2) satisfying certain
conditions, let Y be its complement, and let p be the projection onto the
second factor. Both X and Y are parametrized spaces with respect to the
projection. The parametrized homology is a variant of zigzag persistent
homology that measures how the homology of the level sets of the space changes
as we vary the parameter. We show that if (X, p|_X) has a well-defined
parametrized homology, then the pair (Y, p|_Y) has a well-defined reduced
parametrized homology. We also establish a relationship between the
parametrized homology of (X, p|_X) and the reduced parametrized homology of (Y,
p|_Y).


title:
Study on perturbation schemes for achieving the real PMNS matrix from
  various symmetric textures

abstract:
  The PMNS matrix displays an obvious symmetry, but not exact. There are
several textures proposed in literature, which possess various symmetry
patterns and seem to originate from different physics scenarios at high energy
scales. To be consistent with the experimental measurement, all of the
regularities slightly decline, i.e. the symmetry must be broken. Following the
schemes given in literature, we modify the matrices (9 in total) to gain the
real PMNS matrix by perturbative rotations. The transformations may provide
hints about the underlying physics at high energies and the breaking mechanisms
which apply during the evolution to the low energy scale, especially the
results may be useful for the future model builders.


title:
Cosmological model with local symmetry of very special relativity and
  constraints on it from supernovae

abstract:
  Based on Cohen \& Glashow's very special relativity [A. G. Cohen and S. L.
Glashow, Phys. Rev. Lett. {\bf 97} (2006) 021601], we propose an anisotropic
modification to the Friedmann-Robertson-Walker (FRW) line element. An
arbitrarily oriented 1-form is introduced and the FRW spacetime becomes of the
Randers-Finsler type. The 1-form picks out a privileged axis in the universe.
Thus, the cosmological redshift as well as the Hubble diagram of the type Ia
supernovae (SNe Ia) becomes anisotropic. By directly analyzing the Union2
compilation, we obtain the privileged axis pointing to
\((l,b)=({304^\circ}\pm{43^\circ},{-27^\circ}\pm{13^\circ})\)
(\(68\%~\rm{C.L.}\)). This privileged axis is close to those obtained by
comparing the best-fit Hubble diagrams in pairs of hemispheres. It should be
noticed that the result is consistent with isotropy at the \(1\sigma\) level
since the anisotropic magnitude is \(D=0.03\pm 0.03\).


title:
Randomness Effect on the Temperature Dependence of the Finite Field
  Magnetization of a One-Dimensional Spin Gapped System

abstract:
  We investigate the temperature dependence of the finite-field magnetization
of the S=1/2 bond-alternating XY model in the Random magnetic field along the
z-direction having the Lorentzian distribution. The random-averaged free energy
can be exactly calculated, which enables us to obtain the thermodynamical
quantities. The temperature dependence of the finite-field magnetization shows
various behaviors depending on the parameters $\delta$ and $\Gamma$, where
$\delta$ and $\Gamma$ are the bond-alternation parameter and the Lorentzian
distribution parameter, respectively.


title: Simulated Faraday Rotation Measures toward High Galactic Latitudes

abstract:
  We study the Faraday rotation measure (RM) due to the Galactic magnetic field
(GMF) toward high Galactic latitudes. The RM arises from the global, regular
component as well as from the turbulent, random component of the GMF. We model
the former based on observations and the latter using the data of
magnetohydrodynamic turbulence simulations. For a large number of different GMF
models, we produce mock RM maps around the Galactic poles and calculate various
statistical quantities with the RM maps. We find that the observed medians of
RMs toward the north and south Galactic poles, $\sim 0.0\pm 0.5 {\rm rad
m^{-2}}$ and $\sim +6.3\pm 0.5 {\rm rad m^{-2}}$, are difficult to explain with
any of our many alternate GMF models. The standard deviation of observed RMs,
$\sim 9 {\rm rad m^{-2}}$, is clearly larger than that of simulated RMs. The
second-order structure function of observed RMs is substantially larger than
that of simulated RMs, especially at small angular scales. We discuss other
possible contributions to RM toward high Galactic latitudes. Besides
observational errors and the intrinsic RM of background radio sources against
which RM is observed, we suggest that the RM due to the intergalactic magnetic
field may account for a substantial fraction of the observed RM. Finally we
note that reproducing the observed medians may require additional components
or/and structures of the GMF that are not present in our models.


title: Finsler geometric perspective on the bulk flow in the universe

abstract:
  Astronomical observations showed that there may exist a bulk flow with
peculiar velocities in the universe, which contradicts with the (\Lambda)CDM
model. The bulk flow reveals that the observational universe is anisotropic at
large scales. In fact, a more reliable observation on the anisotropy of
spacetime comes from the CMB power spectra. The WMAP and Planck satellites both
show that there is a hemispherical power asymmetry at large-angular scales. In
this paper, we propose a "wind" scenario to the bulk flow (or the anisotropy of
spacetime). Under the influence of the "wind", the spacetime metric could
become a Finsler structure. By resolving the null geodesic equation, we obtain
the modified luminosity distance, which has a dipolar form at the leading
order. Thus, the "wind" describes well the bulk flow. In addition, we perform a
least-(\chi^2) fit to the data of type Ia supernovae (SNe Ia) in the Union2.1
compilation. The peculiar velocity of the bulk flow has an upper limit
(v_{bulk}\lesssim 4000 \rm{km/s}), which is compatible with all the existing
observational values.


title: Concurrent Cyber Physical Systems:Tensor State Space Representation

abstract:
  In this research paper, state space representation of concurrent, linearly
coupled dynamical systems is discussed. It is reasoned that the Tensor State
Space Representation (TSSR) proposed in [Rama1] is directly applicable in such
a problem. Also some discussion on linearly coupled, concurrent systems
evolving on multiple time scales is included. Briefly new ideas related to
distributed signal processing in cyber physical systems are included.


title:
Conditions for Existence of Dual Certificates in Rank-One Semidefinite
  Problems

abstract:
  Several signal recovery tasks can be relaxed into semidefinite programs with
rank-one minimizers. A common technique for proving these programs succeed is
to construct a dual certificate. Unfortunately, dual certificates may not exist
under some formulations of semidefinite programs. In order to put problems into
a form where dual certificate arguments are possible, it is important to
develop conditions under which the certificates exist. In this paper, we
provide an example where dual certificates do not exist. We then present a
completeness condition under which they are guaranteed to exist. For programs
that do not satisfy the completeness condition, we present a completion process
which produces an equivalent program that does satisfy the condition. The
important message of this paper is that dual certificates may not exist for
semidefinite programs that involve orthogonal measurements with respect to
positive-semidefinite matrices. Such measurements can interact with the
positive-semidefinite constraint in a way that implies additional linear
measurements. If these additional measurements are not included in the problem
formulation, then dual certificates may fail to exist. As an illustration, we
present a semidefinite relaxation for the task of finding the sparsest element
in a subspace. One formulation of this program does not admit dual
certificates. The completion process produces an equivalent formulation which
does admit dual certificates.


title:
Efficient learning strategy of Chinese characters based on network
  approach

abstract:
  Based on network analysis of hierarchical structural relations among Chinese
characters, we develop an efficient learning strategy of Chinese characters. We
regard a more efficient learning method if one learns the same number of useful
Chinese characters in less effort or time. We construct a node-weighted network
of Chinese characters, where character usage frequencies are used as node
weights. Using this hierarchical node-weighted network, we propose a new
learning method, the distributed node weight (DNW) strategy, which is based on
a new measure of nodes' importance that takes into account both the weight of
the nodes and the hierarchical structure of the network. Chinese character
learning strategies, particularly their learning order, are analyzed as
dynamical processes over the network. We compare the efficiency of three
theoretical learning methods and two commonly used methods from mainstream
Chinese textbooks, one for Chinese elementary school students and the other for
students learning Chinese as a second language. We find that the DNW method
significantly outperforms the others, implying that the efficiency of current
learning methods of major textbooks can be greatly improved.


title: Numerical Approximation of Stationary Distribution for SPDEs

abstract:
  In this paper, we show that the exponential integrator scheme both in spatial
discretization and time discretization for a class of stochastic partial
differential equations has a unique stationary distribution whenever the
stepsize is sufficiently small, and reveal that the weak limit of the law for
the exponential integrator scheme is in fact the counterpart for the stochastic
partial differential equation considered.


title:
One-dimensional helical transport in topological insulator nanowire
  interferometers

abstract:
  The discovery of three-dimensional (3D) topological insulators opens a
gateway to generate unusual phases and particles made of the helical surface
electrons, proposing new applications using unusual spin nature. Demonstration
of the helical electron transport is a crucial step to both physics and device
applications of topological insulators. Topological insulator nanowires, of
which spin-textured surface electrons form 1D band manipulated by enclosed
magnetic flux, offer a unique nanoscale platform to realize quantum transport
of spin-momentum locking nature. Here, we report an observation of a
topologically protected 1D mode of surface electrons in topological insulator
nanowires existing at only two values of half magnetic quantum flux ($\pm$h/2e)
due to a spin Berry's phase ($\pi$). The helical 1D mode is robust against
disorder but fragile against a perpendicular magnetic field breaking
time-reversal-symmetry. This result demonstrates a device with robust and
easily accessible 1D helical electronic states from 3D topological insulators,
a unique nanoscale electronic system to study topological phenomena.


title:
Transition linewidth of cross-correlations in random intensity
  fluctuations in EIT

abstract:
  It is known that cross-correlation between the random intensity fluctuations
of two lasers forming electromagnetically-induced transparency (EIT) exhibits a
transition from correlation to anticorrelation. We study the linewidth behavior
of this transition and have found the linewidth is below the (effective)
coherence lifetime limit and is only limited by competing noises. We
established a numerical model which reveals the linewidth dependence on laser
linewidth and laser power. Our experiments using lasers with different
linewidth showed results in qualitative agreement with the model. This result
is useful for quantum optics using EIT, and may also have applications in
spectroscopy and precision measurements.


title: Are hadrons simpler than they seem?

abstract:
  I briefly review a systematic approximation scheme of QCD in which the quark
model picture of hadrons emerges at lowest order. A linear A^0 potential arises
if Gauss' law is solved with a non-vanishing boundary condition at spatial
infinity. Similarly to the Dirac case one can describe relativistic states
including any number of particle pairs (sea quarks) using valence wave
functions, whose norms give {\em inclusive} probability densities. Provided
\alpha_s(Q^2) freezes in the infrared, perturbative corrections to the S-matrix
can be calculated in the usual way, but with states bound by the linear
\order{\alpha_s^0} potential instead of plane waves in the in and out states.


title:
On the HI column density - radio source size anti-correlation in compact
  radio sources

abstract:
  Existing studies of the atomic hydrogen gas content in distant galaxies,
through the absorption of the 21-cm line, often infer that the total column
density is anti-correlated with the linear extent of the background radio
source. We investigate this interpretation, by dissecting the various
parameters from which the column density is derived, and find that the
relationship is driven primarily by the observed optical depth, which, for a
given absorber size, is anti-correlated with the linear size. Therefore, the
inferred anti-correlation is merely the consequence of geometry, in conjunction
with the assumption of a common spin temperature/covering factor ratio for each
member of the sample, an assumption for which there is scant observational
justification. While geometry can explain the observed correlation, many radio
sources comprise two radio lobes and so we model the projected area of a two
component emitter intercepted by a foreground absorber. From this, the observed
optical depth/linear size relationship is best reproduced through models which
approximate either of the two Fanaroff & Riley classifications, although the
observed scatter in the sample cannot be duplicated using a single deprojected
radio source size. Furthermore, the trend is best reproduced using an absorber
of diameter ~100 - 1000 pc, which is also the range of values of linear sizes
at which the 21-cm detection rate peaks. This may indicate that this is the
characteristic linear size of the absorbing gas structure.


title:
Phase transitions of the q-state Potts model on multiply-laced
  Sierpinski gaskets

abstract:
  We present an exact solution of the q-state Potts model on a class of
generalized Sierpinski fractal lattices. The model is shown to possess an
ordered phase at low temperatures and a continuous transition to the high
temperature disordered phase at any q>=1. Multicriticality is observed in the
presence of a symmetry-breaking field. Exact renormalization group analysis
yields the phase diagram of the model and a complete set of critical exponents
at various transitions.


title:
Fermi-LAT study of two gamma-ray binaries, HESS J0632+057 and AGL
  J2241+4454

abstract:
  GeV gamma-ray emission from two gamma-ray binary candidates, HESS J0632+057
and AGL J2241+4454, which were recently reported by H.E.S.S. and AGILE,
respectively, have been searched for using the Fermi-LAT archival dataset.
Spatial and temporal distribution of gamma-ray events are studied, but there
was no evidence for GeV gamma-ray signal from either sources.


title:
Complex Magnetic Phase Diagram of a Geometrically Frustrated Sm Lattice:
  SmPd2Al3 case

abstract:
  Magnetism in SmPd2Al3 was investigated on a single crystal by magnetometry
and neutron diffraction. SmPd2Al3 represents a distinctive example of the Sm
magnetism exhibiting complex magnetic behavior at low temperatures with four
consecutive magnetic phase transitions at 3.4, 3.9, 4.3 and 12.5 K. The rich
magnetic phase diagram of this compound reflects the specific features of the
Sm3+ ion, namely the energy nearness of the ground-state multiplet J = 5/2 and
the first excited multiplet J = 7/2 in conjunction with strong crystal field
influence. Consequently, a significantly reduced Sm magnetic moment in
comparison with the theoretical Sm3+ free-ion value is observed. Despite the
strong neutron absorption by natural samarium and the small Sm magnetic moment
(~ 0.2 {\mu}B) we have successfully determined the magnetic k-vector (1/3, 1/3,
0) of the phase existing in the temperature interval 12.5 - 4.3 K. This
observation classifies the SmPd2Al3 compound as a magnetically frustrated
system. The complex magnetic behavior of this material is further illustrated
by kinetic effects of the magnetization inducing rather complicated magnetic
structure with various metastable states.


title:
High-dose high-temperature emission of LiF:Mg,Cu,P: thermally and
  radiation induced loss & recovery of its sensitivity

abstract:
  Highly sensitive LiF:Mg,Cu,P (MCP) detectors enable measurements of radiation
doses from tens of nanograys up to a few kilograys, where the saturation of the
signal of the main dosimetric peak occurs. Thanks to the recently observed
high-dose high-temperature emission of MCP detectors heated to temperatures up
to 600{\deg}C after exposures to radiation doses ranging from 1 kGy to 1 MGy, a
new method of TL measurement of radiation doses has been recently developed at
the Institute of Nuclear Physics (IFJ). This method can measure doses ranging
from micrograys up to a megagray. So far, high dose measurements were performed
on fresh MCP samples and each detector was used only once, because as a result
of these measurements, the detectors lose their sensitivity to a large extent.
In this study, a specific thermal treatment intended to fully restore the loss
of MCPs TL sensitivity was sought. We have investigated several annealing
procedures, applying different temperatures (from 400{\deg}C up to 700{\deg}C)
for different periods of time (10-30 minutes) in argon atmosphere. In this way
we were able to recover MCP sensitivity fully, allowing for reuse of the
samples after high-dose irradiation and high-temperature measurement.


title:
Physical Layer Security in Cellular Networks: A Stochastic Geometry
  Approach

abstract:
  This paper studies the information-theoretic secrecy performance in
large-scale cellular networks based on a stochastic geometry framework. The
locations of both base stations and mobile users are modeled as independent
two-dimensional Poisson point processes. We consider two important features of
cellular networks, namely, information exchange between base stations and cell
association, to characterize their impact on the achievable secrecy rate of an
arbitrary downlink transmission with a certain portion of the mobile users
acting as potential eavesdroppers. In particular, tractable results are
presented under diverse assumptions on the availability of eavesdroppers'
location information at the serving base station, which captures the benefit
from the exchange of the location information between base stations.


title: Power-law of Aggregate-size Spectra in Natural Systems

abstract:
  Patterns of animate and inanimate systems show remarkable similarities in
their aggregation. One similarity is the double-Pareto distribution of the
aggregate-size of system components. Different models have been developed to
predict aggregates of system components. However, not many models have been
developed to describe probabilistically the aggregate-size distribution of any
system regardless of the intrinsic and extrinsic drivers of the aggregation
process. Here we consider natural animate systems, from one of the greatest
mammals - the African elephant (\textit{Loxodonta africana}) - to the
\textit{Escherichia coli} bacteria, and natural inanimate systems in river
basins. Considering aggregates as islands and their perimeter as a curve
mirroring the sculpting network of the system, the probability of exceedence of
the drainage area, and the Hack's law are shown to be the the Kor\v{c}ak's law
and the perimeter-area relationship for river basins. The perimeter-area
relationship, and the probability of exceedence of the aggregate-size provide a
meaningful estimate of the same fractal dimension. Systems aggregate because of
the influence exerted by a physical or processes network within the system
domain. The aggregate-size distribution is accurately derived using the
null-method of box-counting on the occurrences of system components. The
importance of the aggregate-size spectrum relies on its ability to reveal
system form, function, and dynamics also as a function of other coupled
systems. Variations of the fractal dimension and of the aggregate-size
distribution are related to changes of systems that are meaningful to monitor
because potentially critical for these systems.


title: Exactly Solvable BCS-BEC crossover Hamiltonians

abstract:
  We demonstrate a novel approach that allows the determination of very general
classes of exactly solvable Hamiltonians via Bethe ansatz methods. This
approach combines aspects of both the co-ordinate Bethe ansatz and algebraic
Bethe ansatz. The eigenfunctions are formulated as factorisable operators
acting on a suitable reference state. Yet, we require no prior knowledge of
transfer matrices or conserved operators. By taking a variational form for the
Hamiltonian and eigenstates we obtain general exact solvability conditions. The
procedure is conducted in the framework of Hamiltonians describing the
crossover between the low-temperature phenomena of superconductivity, in the
Bardeen-Cooper-Schrieffer (BCS) theory, and Bose-Einstein condensation (BEC).


title:
The effect of a density dependent bag constant on the structure of hot
  neutron star with a quark core

abstract:
  As we go from center toward the surface of a neutron star, the state of
baryonic matter changes from the de-confined quark-gluon to a mixed phase of
quark and hadronic matter, and a thin crust of hadronic matter. For the quark
matter, within MIT bag model, the total energy density of the system is the
kinetic energy for non-interacting quarks plus a bag constant. In this article
first we have considered a density dependent bag constant obtained using the
recent experimental results of CERN SPS on the formation of a quark-gluon
plasma. For calculations of the hadron phase, we use the lowest order
constrained variational method. The equation of state of mixed phase has been
determined using Gibbs conditions. Finally, we have calculated the structure of
a hot neutron star with quark core employing TOV equation. Our results show
that a density dependent bag constant leads to a higher mass and lower radius
for the hot neutron star with respect to the case in which we use a fixed bag
constant.


title:
On parametrical expressibility in the free void-generated diagonalizable
  algebra

abstract:
  In the present paper we show that there are infinitely many classes of term
functions in the free-void generated diagonalizable algebra, which are
precomplete with respect to parametrical expressibility of functions.


title:
Impact of Gd doping on morphology and superconductivity of NbN sputtered
  thin films

abstract:
  We report effect of Gd inclusion in the NbN superconductor thin films. The
films are deposited on single crystalline Silicon (100) by DC reactive
sputtering technique i.e., deposition of Nb and Gd in presence of reactive N2
gas. The fabricated relatively thick films (400 nm) are crystallized in cubic
structure. These films are characterized for their morphology, elemental
analysis and roughness by Scanning Electron Microscopy (SEM), Energy Dispersive
X-ray spectroscopy (EDAX) and Atomic Force Microscopy (AFM) respectively. The
optimized film (maximum Tc) is achieved with gas ratio of Ar:N2 (80:20) for
both pristine and Gd doped films. The optimized NbN film possesses Tc (R=0) in
zero and 140kOe fields are at 14.8K and 8.8K respectively. The Gd doped NbN
film showed Tc (R=0) in zero and 130kOe fields at 11.2K and 6.8 K respectively.
The upper critical field Hc2(0) of the studied superconducting films is
calculated from the magneto-transport [R(T)H] measurements using GL equations.
It is found that Gd doping deteriorated the superconducting performance of NbN.


title: The Prototype GAPS (pGAPS) Experiment

abstract:
  The General Antiparticle Spectrometer (GAPS) experiment is a novel approach
for the detection of cosmic ray antiparticles. A prototype GAPS experiment
(pGAPS) was successfully flown on a high-altitude balloon in June of 2012. The
goals of the pGAPS experiment were: to test the operation of lithium drifted
silicon (Si(Li)) detectors at balloon altitudes, to validate the thermal model
and cooling concept needed for engineering of a full-size GAPS instrument, and
to characterize cosmic ray and X-ray backgrounds. The instrument was launched
from the Japan Aerospace Exploration Agency's (JAXA) Taiki Aerospace Research
Field in Hokkaido, Japan. The flight lasted a total of 6 hours, with over 3
hours at float altitude (~33 km). Over one million cosmic ray triggers were
recorded and all flight goals were met or exceeded.


title:
Universal damping behavior of dipole oscillations of one-dimensional
  ultracold gases induced by quantum phase slips

abstract:
  We study superflow decay via quantum phase slips in trapped one-dimensional
(1D) quantum gases through dipole oscillations induced by sudden displacement
of the trapping potential. We find the relation between the damping rate of the
dipole oscillation $G$ and the phase-slip nucleation rate $\Gamma$ as $G\propto
\Gamma/v$, where $v$ is the flow velocity. This relation allows us to show that
damping of 1D Bose gases in optical lattices, which has been extensively
studied in experiment, is due to quantum phase slips. It is also found that the
damping rate versus the flow velocity obeys the scaling formula for an impurity
potential even in the absence of an explicit impurity. We suggest that the
damping rate at a finite temperature exhibits a universal crossover behavior
upon changing the flow velocity.


title: Proper formulation of viscous dissipation for nonlinear waves in solids

abstract:
  In order to model nonlinear viscous dissipative motions in solids, acoustical
physicists usually add terms linear in dot{E}, the material time derivative of
the Lagrangian strain tensor E, to the elastic stress tensor sigma derived from
the expansion to the third- (sometimes fourth-) order of the strain energy
density e=e(trace(E), trace(E^2), trace(E^3)). Here, it is shown that this
practice, which has been widely used in the past three decades or so, is
physically wrong for at least two reasons, and that it should be corrected. One
reason is that the elastic stress tensor sigma is not symmetric while dot{E) is
symmetric, so that motions for which sigma + sigma^T <> 0 will give rise to
elastic stresses which have no viscous pendant. Another reason is that dot{E}
is frame-invariant, while sigma is not, so that an observer transformation
would alter the elastic part of the total stress differently than it would
alter the dissipative part, thereby violating the fundamental principle of
material frame-indifference. These problems can have serious consequences for
nonlinear shear wave propagation in soft solids, as seen here with an example
of a kink in almost incompressible soft solids.


title: Unified Description of Matrix Mechanics and Wave Mechanics I

abstract:
  In this article, we discard the bra-ket notation and its correlative
definitions, given by Paul Dirac. The quantum states are only described by the
wave functions. The fundamental concepts and definitions in quantum mechanics
is simplified. The operator, wave functions and square matrix are represented
in the same expression which directly corresponds to the system of equations
without additional introduction of the matrix representation of operator. It
can make us to convert the operator relations into the matrix relations.
According to the relations between the matrices, the matrix elements will be
determined. Furthermore, the first order differential equations will be given
to find the solution of equations. As a result, we unified the descriptions of
the matrix mechanics and the wave mechanics.


title: Gamma-ray Burst Theory in the Fermi Era

abstract:
  The Large Area Telescope (LAT) on-board the Fermi satellite detected emission
above 20 MeV only in a small fraction of the long gamma-ray bursts (GRBs)
detected by the Fermi Gamma-ray Burst Monitor (GBM) at 8 keV-40 MeV. Those
bursts that were detected by the LAT were among the brightest GBM bursts. The
emission detected by LAT seerms to be delayed respect to the one detected by
the GBM. In this review I will show the main implications of these LAT
observations on the GRB models and discuss the importance of a synergy between
Fermi and other telescopes.


title:
Reconstruction and constraining of the jerk parameter from OHD and SNe
  Ia observations

abstract:
  Compared with the plentiful researches of the Hubble parameter and
deceleration factor, the third time derivative of the scale factor $a(t)$ in
the FRW cosmology, namely, the jerk parameter $j$ still lacks attention. In
order to study the properties of $j$, we propose several kinds of
parameterizations of $j(z)$ as a function of the redshift $z$. By setting the
standard $\Lambda$CDM model as the fiducial model, we constrain the jerk models
with the observational Hubble parameter data (OHD) and Type Ia Supernovae (SNe)
observations. We find that the perturbation of $j(z)$ favors a value of nearly
zero and the $\Lambda$CDM is well accommodated by the jerk reconstruction. We
also compare the powers of OHD and SNe in constraining the jerk models in
detail, and find that the newly released OHD measurement at $z=2.3$ can improve
the constraint significantly, even tighter than the SNe one. Furthermore, we
analyze the jerk models by calculating the Hubble parameter, equation of state,
the deceleration factor and $Om(z)$ diagnostic. Our results show that the
universe is indeed undergoing an accelerated expansion phase following the
matter-dominated one, which is consistent with the standard model by
observations.


title:
A novel approach to construct numerical methods for stochastic
  differential equations

abstract:
  In this paper we propose a new numerical method for solving stochastic
differential equations (SDEs). As an application of this method we propose an
explicit numerical scheme for a super linear SDE for which the usual Euler
scheme diverges.


title: Focus point gauge mediation in product group unification

abstract:
  In certain models of gauge-mediated supersymmetry breaking with messenger
fields in incomplete GUT multiplets, the radiative corrections to the Higgs
potential cancel out during renormalization group running. This allows for
relatively heavy superpartners and for a 125 GeV Higgs while the fine-tuning
remains modest. In this paper, we show that such gauge mediation models with
"focus point" behaviour can be naturally embedded into a model of SU(5) x U(3)
product group unification.


title:
Unifying Geometric Entanglement and Geometric Phase in a Quantum Phase
  Transition

abstract:
  Geometric measure of entanglement and geometric phase have recently been used
to analyze quantum phase transition in the XY spin chain. We unify these two
approaches by showing that the geometric entanglement and the geometric phase
are respectively the real and imaginary parts of a complex-valued geometric
entanglement, which can be investigated in typical quantum interferometry
experiments. We argue that the singular behavior of the complex-value geometric
entanglement at a quantum critical point is a characteristic of any quantum
phase transition, by showing that the underlying mechanism is the occurrence of
level crossings associated with the underlying Hamiltonian.


title:
On Robust Face Recognition via Sparse Encoding: the Good, the Bad, and
  the Ugly

abstract:
  In the field of face recognition, Sparse Representation (SR) has received
considerable attention during the past few years. Most of the relevant
literature focuses on holistic descriptors in closed-set identification
applications. The underlying assumption in SR-based methods is that each class
in the gallery has sufficient samples and the query lies on the subspace
spanned by the gallery of the same class. Unfortunately, such assumption is
easily violated in the more challenging face verification scenario, where an
algorithm is required to determine if two faces (where one or both have not
been seen before) belong to the same person. In this paper, we first discuss
why previous attempts with SR might not be applicable to verification problems.
We then propose an alternative approach to face verification via SR.
Specifically, we propose to use explicit SR encoding on local image patches
rather than the entire face. The obtained sparse signals are pooled via
averaging to form multiple region descriptors, which are then concatenated to
form an overall face descriptor. Due to the deliberate loss spatial relations
within each region (caused by averaging), the resulting descriptor is robust to
misalignment & various image deformations. Within the proposed framework, we
evaluate several SR encoding techniques: l1-minimisation, Sparse Autoencoder
Neural Network (SANN), and an implicit probabilistic technique based on
Gaussian Mixture Models. Thorough experiments on AR, FERET, exYaleB, BANCA and
ChokePoint datasets show that the proposed local SR approach obtains
considerably better and more robust performance than several previous
state-of-the-art holistic SR methods, in both verification and closed-set
identification problems. The experiments also show that l1-minimisation based
encoding has a considerably higher computational than the other techniques, but
leads to higher recognition rates.


title: Modeling the mechano-chemistry of the \phi 29 DNA translocation motor

abstract:
  We present a study of the DNA translocation of the bacteriophage \phi 29
packaging molecular motor. From the experimental available information we
present a model system based in an stochastic fashing potential, which
reproduces the experimental observations such as: detailed trajectories, steps
and substeps, spatial correlation, and velocity. Moreover the model allows the
evaluation of power and efficiency of this motor. We have found that the
maximum power regime does not correspond with that of the maximum efficiency.
These informations can stimulate further experiments.


title: Forms and Linear Network Codes

abstract:
  We present a general theory to obtain linear network codes utilizing forms
and obtain explicit families of equidimensional vector spaces, in which any
pair of distinct vector spaces intersect in the same small dimension. The
theory is inspired by the methods of the author utilizing the osculating spaces
of Veronese varieties.
  Linear network coding transmits information in terms of a basis of a vector
space and the information is received as a basis of a possibly altered vector
space. Ralf Koetter and Frank R. Kschischang introduced a metric on the set af
vector spaces and showed that a minimal distance decoder for this metric
achieves correct decoding if the dimension of the intersection of the
transmitted and received vector space is sufficiently large.
  The vector spaces in our construction are equidistant in the above metric and
the distance between any pair of vector spaces is large making them suitable
for linear network coding.
  The parameters of the resulting linear network codes are determined.


title: Newtonian Kinetic Theory and the Ergodic-Nonergodic Transition

abstract:
  In a recent work we have discussed how kinetic theory, the statistics of
classical particles obeying Newtonian dynamics, can be formulated as a field
theory. The field theory can be organized to produce a self-consistent
perturbation theory expansion in an effective interaction potential. In the
present work we use this development for investigating ergodic-nonergodic (ENE)
transitions in dense fluids. The theory is developed in terms of a core problem
spanned by the variables $\rho$, the number density, and $B$, a response
density. We set up the perturbation theory expansion for studying the
self-consistent model which gives rise to a ENE transition. Our main result is
that the low-frequency dynamics near the ENE transition is the same for
Smoluchowski and Newtonian dynamics. This is true despite the fact that term by
term in a density expansion the results for the two dynamics are fundamentally
different.


title:
Discovery of TeV gamma-ray emission from PKS 0447-439 and derivation of
  an upper limit on its redshift

abstract:
  Very high-energy gamma-ray emission from PKS 0447-439 was detected with the
H.E.S.S. Cherenkov telescope array in December 2009. This blazar is one of the
brightest extragalactic objects in the Fermi Bright Source List and has a hard
spectrum in the MeV to GeV range. In the TeV range, a photon index of 3.89 +-
0.37 (stat) +- 0.22 (sys) and a flux normalisation at 1 TeV, Phi(1 TeV) = (3.5
+- 1.1 (stat) +- 0.9 (sys)) x 10^{-13} cm^{-2} s^{-1} TeV^{-1}, were found. The
detection with H.E.S.S. triggered observations in the X-ray band with the Swift
and RXTE telescopes. Simultaneous UV and optical data from Swift UVOT and data
from the optical telescopes ATOM and ROTSE are also available. The spectrum and
light curve measured with H.E.S.S. are presented and compared to the
multi-wavelength data at lower energies. A rapid flare is seen in the Swift XRT
and RXTE data, together with a flux variation in the UV band, at a time scale
of the order of one day. A firm upper limit of z < 0.59 on the redshift of PKS
0447-439 is derived from the combined Fermi-LAT and H.E.S.S. data, given the
assumptions that there is no upturn in the intrinsic spectrum above the
Fermi-LAT energy range and that absorption on the Extragalactic Background
Light (EBL) is not weaker than the lower limit provided by current models. The
spectral energy distribution is well described by a simple one-zone Synchrotron
Self-Compton (SSC) scenario, if the redshift of the source is less than z <~
0.4.


title: Red supergiants and stellar evolution

abstract:
  We review the significant role played by red supergiants (RSGs) in stellar
populations, and some challenges and questions they raise for theoretical
stellar evolution. We present how metallicity and rotation modify the way stars
go to the red part of the Hertzsprung- Russell diagram or come back from it,
and how RSGs might keep a trace of their main-sequence evolution. We compare
theoretical popu- lation ratios with observed ones.


title: Chiral spin-wave edge modes in dipolar magnetic thin films

abstract:
  Based on a linearized Landau-Lifshitz equation, we show that two-dimensional
periodic allay of ferromagnetic particles coupled with magnetic dipole-dipole
interactions supports chiral spin-wave edge modes, when subjected under the
magnetic field applied perpendicular to the plane. The mode propagates along a
one-dimensional boundary of the system in a unidirectional way and it always
has a chiral dispersion within a band gap for spin-wave volume modes. Contrary
to the well-known Damon-Eshbach surface mode, the sense of the rotation depends
not only on the direction of the field but also on the strength of the field;
its chiral direction is generally determined by the sum of the so-called Chern
integers defined for spin-wave volume modes below the band gap. Using simple
tight-binding descriptions, we explain how the magnetic dipolar interaction
endows spin-wave volume modes with non-zero Chern integers and how their values
will be changed by the field.


title:
Coarse-grained forms for equations describing the microscopic motion of
  particles in a fluid

abstract:
  Equations of motion for the microscopic number density $\hat{\rho}({\bf
x},t)$ and the momentum density $\hat{\bf g}({\bf x},t)$ of a fluid have been
obtained in the past from the corresponding Langevin equations representing the
dynamics of the fluid particles. In the present work we average these exact
equations of microscopic dynamics over the local equilibrium distribution to
obtain stochastic partial differential equations for the coarse grained
densities with smooth spatial and temporal dependence. In particular, we
consider Dean's exact balance equation for the microscopic density of a system
of interacting Brownian particles to obtain the basic equation of the dynamic
density functional theory. In the thermally averaged equation for the coarse
grained density ${\rho}({\bf x},t)$, the related dependence on the bare
interaction potential in Dean's equation is converted to that on the
corresponding direct correlation functions of the density functional theory.


title: Higgs potential and confinement in Yang-Mills theory on exotic R^4

abstract:
  We show that pure SU(2) Yang-Mills theory formulated on certain exotic R^4
from the radial family shows confinement. The condensation of magnetic
monopoles and the qualitative form of the Higgs potential are derived from the
exotic R^4, e. A relation between the Higgs potential and inflation is
discussed. Then we obtain a formula for the Higgs mass and discuss a particular
smoothness structure so that the Higgs mass agrees with the experimental value.
The singularity in the effective dual U(1) potential has its cause by the
exotic 4-geometry and agrees with the singularity in the maximal abelian gauge
scenario. We will describe the Yang-Mills theory on e in some limit as the
abelian-projected effective gauge theory on the standard R^4. Similar results
can be derived for SU(3) Yang-Mills theory on an exotic R^4 provided dual
diagonal effective gauge bosons propagate in the exotic 4-geometry.


title: Joint power and admission control via p norm minimization deflation

abstract:
  In an interference network, joint power and admission control aims to support
a maximum number of links at their specified signal to interference plus noise
ratio (SINR) targets while using a minimum total transmission power. In our
previous work, we formulated the joint control problem as a sparse
$\ell_0$-minimization problem and relaxed it to a $\ell_1$-minimization
problem. In this work, we propose to approximate the $\ell_0$-optimization
problem to a p norm minimization problem where $0<p<1$, since intuitively p
norm will approximate 0 norm better than 1 norm. We first show that the
$\ell_p$-minimization problem is strongly NP-hard and then derive a
reformulation of it such that the well developed interior-point algorithms can
be applied to solve it. The solution to the $\ell_p$-minimization problem can
efficiently guide the link's removals (deflation). Numerical simulations show
the proposed heuristic outperforms the existing algorithms.


title: Fabry-Perot enhanced Faraday rotation in graphene

abstract:
  We demonstrate that giant Faraday rotation in graphene in the terahertz range
due to the cyclotron resonance is further increased by constructive Fabry-Perot
interference in the supporting substrate. Simultaneously, an enhanced total
transmission is achieved, making this effect doubly advantageous for
graphene-based magneto-optical applications. As an example, we present
far-infrared spectra of epitaxial multilayer graphene grown on the C-face of
6H-SiC, where the interference fringes are spectrally resolved and a Faraday
rotation up to 0.15 radians (9{\deg}) is attained. Further, we discuss and
compare other ways to increase the Faraday rotation using the principle of an
optical cavity.


title: Improving Energy Efficiency in MANETs by Multi-Path Routing

abstract:
  Some multi-path routing algorithm in MANET, simultaneously send information
to the destination through several directions to reduce end-to-end delay. In
all these algorithms, the sent traffic through a path affects the adjacent path
and unintentionally increases the delay due to the use of adjacent paths.
Because, there are repetitive competitions among neighboring nodes, in order to
obtain the joint channel in adjacent paths. The represented algorithm in this
study tries to discover the distinct paths between source and destination nodes
with using Omni directional antennas, to send information through these
simultaneously. For this purpose, the number of active neighbors is counted in
each direction with using a strategy. These criterions are effectively used to
select routes. Proposed algorithm is based on AODV routing algorithm, and in
the end it is compared with AOMDV, AODVM, and IZM-DSR algorithms which are
multi-path routing algorithms based on AODV and DSR. Simulation results show
that using the proposed algorithm creates a significant improvement in energy
efficiency and reducing end-to-end delay.


title:
Arbitrary bending of optical solitonic beam regulated by boundary
  excitations in a doped resonant medium

abstract:
  Bending of a shape-invariant optical beam is achieved so far along parabolic
or circular curves. Borrowing ideas used in nonlinear optical communication, we
propose such a bending along any preassigned curve or surface, controlled by
the boundary population inversion of atoms in an Erbium doped medium. The
optical beam generated in a nonlinear Kerr medium and transmitted through a
doped resonant medium as an accelerating soliton predicted here, should be
realizable experimentally and applicable to nonlinear events in other areas
like plasma or ocean wave.


title:
Proper factorization theorems in high-energy scattering near the
  endpoint

abstract:
  Consistent factorization theorems in high-energy scattering near the
threshold are presented in the framework of the soft-collinear effective
theory. Traditional factorization theorem separates the soft and collinear
parts successfully, but a final step should be supplemented if each part
encounters infrared divergence. We present factorization theorems in which the
infrared divergences appear only in the parton distribution functions and the
infrared divergence is removed by carefully separating and reorganizing
collinear and soft parts. The underlying physical idea is to isolate and remove
the soft contributions systematically from the collinear part in loop
corrections order by order. After this procedure, each factorized term in the
scattering cross sections is free of infrared divergence, and can be safely
computed using perturbation theory. This factorization procedure can be applied
to various high-energy scattering processes. We show factorization theorems in
Drell-Yan processes, deep inelastic scattering and Higgs production near the
endpoint.


title:
Magnetic Field Driven Electronic Singularities through Metamagnetic
  Phenomena: Case of the Heavy Fermion Antiferromagnet Ce(Ru0.92Rh0.08)2Si2

abstract:
  Thermoelectric power measurements on the heavy fermion antiferromagnet
Ce(Ru0.92Rh0.08)2Si2 under magnetic field (H) show clearly that the
antiferromagnetic state below the critical field Hc ~ 2.8T can be fully
decoupled from the pseudo-metamagnetic crossover at Hm ~ 5.8T which occurs when
the magnetization reaches a critical value. By contrast to the weak field
variation of the Sommerfeld coefficient of the specific heat in the field
window from Hc to Hm, two electronic singularities with opposite signs are
detected in the thermoelectric power. The interplay between the magnetic
instability and the topological change of the Fermi surface is discussed and we
argue similarities to other field instabilities in various heavy fermion
compounds.


title: On an integrable discretisation of the Ablowitz-Ladik hierarchy

abstract:
  Following the general results on the relationships about Backlund
transformations (BTs) and exact discretisation given in a previous work [12],
we consider the Ablowitz-Ladik hierarchy and a corresponding family of BTs.
After discussing the boundary conditions, we show how to get explicit
transformations. The Hamiltonian properties of the maps and of the discrete
flows are examined. The conditions on the parameters of the map giving exact
discretisations are discussed. Finally, analytical and numerical examples are
given.


title: Testing Mutual Duality of Planar Graphs

abstract:
  We introduce and study the problem \mpd, which asks for two planar graphs
$G_1$ and $G_2$ whether $G_1$ can be embedded such that its dual is isomorphic
to $G_2$. Our algorithmic main result is an NP-completeness proof for the
general case and a linear-time algorithm for biconnected graphs. To shed light
onto the combinatorial structure of the duals of a planar graph, we consider
the \emph{common dual relation} $\sim$, where $G_1 \sim G_2$ if and only if
they have a common dual. While $\sim$ is generally not transitive, we show that
the restriction to biconnected graphs is an equivalence relation. In this case,
being dual to each other carries over to the equivalence classes, i.e., two
graphs are dual to each other if and only if any two elements of their
respective equivalence classes are dual to each other.
  To achieve the efficient testing algorithm for \mpd on biconnected graphs, we
devise a succinct representation of the equivalence class of a biconnected
planar graph. It is similar to SPQR-trees and represents exactly the graphs
that are contained in the equivalence class. The testing algorithm then works
by testing in linear time whether two such representations are isomorphic. We
note that a special case of \mpd is testing whether a graph $G$ is self-dual.
Our algorithm handles the case where $G$ is biconnected and our NP-hardness
proof extends to testing self-duality of general planar graphs and also to
testing map self-duality, where a graph $G$ is map self-dual if it admits a
planar embedding $\mathcal G$ such that $G^\star$ is isomorphic to $G$, and
additionally the embedding induced by $\mathcal G$ on $G^\star$ is $\mathcal
G$.


title:
The thermodynamic properties of the high-pressure superconducting state
  in the hydrogen-rich compounds

abstract:
  The ab initio calculations suggest that the superconducting state in CaH6
under the pressure at 150 GPa has the highest critical temperature among the
examined hydrogen-rich compounds. For this reason, the relevant thermodynamic
parameters of the superconducting state in CaH6 have been determined; a wide
range of the Coulomb pseudopotential has been assumed:
$\mu^{\star}\in\left<0.1,0.3\right>$. It has been found that: (i) The critical
temperature (Tc) changes in the range from 243 K to 180 K. (ii) The values of
the ratio of the energy gap to the critical temperature ($R_{\Delta}\equiv
2\Delta\left(0\right)/k_{B}T_{C}$) can be found in the range from 5.42 to 5.02.
(iii) The ratio of the specific heat jump ($\Delta C\left(T_{C}\right)$) to the
value of the specific heat in the normal state ($C^{N}\left(T_{C}\right)$),
which has been represented by the symbol Rc, takes the values from 3.30 to
3.18. (iv) The ratio $R_{H}\equiv
T_{C}C^{N}\left(T_{C}\right)/H^{2}_{C}\left(0\right)$, where
$H_{C}\left(0\right)$ denotes the critical thermodynamic field, changes from
0.122 to 0.125.
  The study has brought out the expressions that correctly predict the values
of the thermodynamic parameters for the superconducting state in CaH6 and for
the compounds: SiH4(H2)2, Si2H6, B2H6, SiH4, GeH4, and PtH. Next, in the whole
family of the hydrogen-rich compounds, the possible ranges of the values have
been determined for Tc, $R_{\Delta}$, Rc, and $R_{H}$. It has been found that
the maximum value of the critical temperature can be equal to 764 K, which very
well correlates with Tc for metallic hydrogen (p=2 TPa). Other parameters
($R_{\Delta}$, Rc, and $R_{H}$) should not deviate from the predictions of the
BCS theory more than the analogous parameters for CaH6.


title:
Phase Transitions in Three-Dimensional Bosonic Systems in Optical
  Lattices

abstract:
  We formulate the Collective Quantum Field Theory for three-dimensional
bosonic optical lattices and evaluate its consequences in a mean-field
approximation to two collective fields, proposed by Fred Cooper et al. and in a
lowest-order Variational Perturbation Theory (VPT). It is shown that present
mean-field approximation predicts some essential features of the experimentally
observed dependence of the critical temperature on the coupling strength and a
second - order quantum phase transition.In contrast to a recent prediction for
atomic gases by Fred Cooper et. al., we find no superfluid state with zero
condensate fraction.


title: $d$-COS-R is FPT via Interval Deletion

abstract:
  A binary matrix $M$ has the Consecutive Ones Property (COP) if there exists a
permutation of columns that arranges the ones consecutively in all the rows.
Given a matrix, the $d$-COS-R problem is to determine if there exists a set of
at most $d$ rows whose deletion results in a matrix with COP. We consider the
parameterized complexity of this problem with respect to the number $d$ of rows
to be deleted as the parameter. The closely related Interval Deletion problem
has recently shown to be FPT [Y. Cao and D. Marx, Interval Deletion is
Fixed-Parameter Tractable, arXiv:1211.5933 [cs.DS],2012]. In this work, we
describe a recursive depth-bounded search tree algorithm in which the problems
at the leaf-level are solved as instances of Interval Deletion. The running
time of the algorithm is dominated by the running time of Interval Deletion,
and therefore we show that $d$-COS-R is fixed-parameter tractable and has a
run-time of $O^*(10^d)$.


title:
On the structure of the magnetic field near a black hole in active
  galactic nuclei

abstract:
  Using the Grad-Shafranov equation, we consider a new analytical model of the
black hole magnetosphere based on the assumption that the magnetic field is
radial near the horizon and uniform (cylindrical) in the jet region. Within
this model, we have managed to show that the angular velocity of particles near
the rotation axis of the black hole can be smaller than one half of the black
hole angular velocity. This result is consistent with the latest numerical
simulations.


title:
A Multi-objective Perspective for Operator Scheduling using Fine-grained
  DVS Architecture

abstract:
  The stringent power budget of fine grained power managed digital integrated
circuits have driven chip designers to optimize power at the cost of area and
delay, which were the traditional cost criteria for circuit optimization. The
emerging scenario motivates us to revisit the classical operator scheduling
problem under the availability of DVFS enabled functional units that can
trade-off cycles with power. We study the design space defined due to this
trade-off and present a branch-and-bound(B/B) algorithm to explore this state
space and report the pareto-optimal front with respect to area and power. The
scheduling also aims at maximum resource sharing and is able to attain
sufficient area and power gains for complex benchmarks when timing constraints
are relaxed by sufficient amount. Experimental results show that the algorithm
that operates without any user constraint(area/power) is able to solve the
problem for most available benchmarks, and the use of power budget or area
budget constraints leads to significant performance gain.


title: On the Inefficiency of Standard Multi-Unit Auctions

abstract:
  We study two standard multi-unit auction formats for allocating multiple
units of a single good to multi-demand bidders. The first one is the
Discriminatory Auction, which charges every winner his winning bids. The second
is the Uniform Price Auction, which determines a uniform price to be paid per
unit. Variants of both formats find applications ranging from the allocation of
state bonds to investors, to online sales over the internet, facilitated by
popular online brokers. For these formats, we consider two bidding interfaces:
(i) standard bidding, which is most prevalent in the scientific literature, and
(ii) uniform bidding, which is more popular in practice. In this work, we
evaluate the economic inefficiency of both multi-unit auction formats for both
bidding interfaces, by means of upper and lower bounds on the Price of Anarchy
for pure Nash equilibria and mixed Bayes-Nash equilibria. Our developments
improve significantly upon bounds that have been obtained recently in
[Markakis, Telelis, ToCS 2014] and [Syrgkanis, Tardos, STOC 2013] for
submodular valuation functions. Moreover, we consider for the first time
bidders with subadditive valuation functions for these auction formats. Our
results signify that these auctions are nearly efficient, which provides
further justification for their use in practice.


title:
Relay Selection for Simultaneous Information Transmission and Wireless
  Energy Transfer: A Tradeoff Perspective

abstract:
  In certain applications, relay terminals can be employed to simultaneously
deliver information and energy to a designated receiver and a radio frequency
(RF) energy harvester, respectively. In such scenarios, the relay that is
preferable for information transmission does not necessarily coincide with the
relay with the strongest channel to the energy harvester, since the
corresponding channels fade independently. Relay selection thus entails a
tradeoff between the efficiency of the information transfer to the receiver and
the amount of energy transferred to the energy harvester. The study of this
tradeoff is the subject on which this work mainly focuses. Specifically, we
investigate the behavior of the ergodic capacity and the outage probability of
the information transmission to the receiver, for a given amount of energy
transferred to the RF energy harvester. We propose two relay selection methods
that apply to any number of available relays. Furthermore, for the case of two
relays, we develop the optimal relay selection method in a maximum capacity /
minimum outage probability sense, for a given energy transfer constraint. A
close-to-optimal selection method that is easier to analyze than the optimal
one is also examined. Closed-form expressions for the capacity-energy and the
outage-energy tradeoffs of the developed schemes are provided and corroborated
by simulations. Interesting insights on the aforementioned tradeoffs are
obtained.


title:
Sampling fractional Brownian motion in presence of absorption: a Markov
  Chain method

abstract:
  We study fractional Brownian motion (fBm) characterized by the Hurst exponent
H. Using a Monte Carlo sampling technique, we are able to numerically generate
fBm processes with an absorbing boundary at the origin at discrete times for a
large number of 10^7 time steps even for small values like H=1/4. The results
are compatible with previous analytical results that the distribution of
(rescaled) endpoints y follow a power law P(y) y^\phi with \phi=(1-H)/H, even
for small values of H. Furthermore, for the case H=0.5 we also study
analytically the finite-length corrections to the first order, namely a plateau
of P(y) for y->0 which decreases with increasing process length. These
corrections are compatible with the numerical results.


title:
Giant phase modulation in a Mach-Zehnder exciton-polariton
  interferometer

abstract:
  We report on a new mechanism of giant phase modulation. The phenomenon arises
when a dispersed photonic mode (slow light) strongly couples to an excitonic
resonance. In such a case, even a small amount of optically injected carriers
creates a potential barrier for the propagating exciton-polariton which
provokes a considerable phase shift. We evidence this effect by fabricating an
exciton-polariton Mach-Zehnder interferometer, modulating the output intensity
by constructive or destructive interferences controlled by optical pumping of a
micrometric size area. The figure of merit for a {\pi} phase shift, defined by
the control power times length of the modulated region, is found at least one
order of magnitude smaller than slow light photonic crystal waveguides.


title:
Directional Emission of Dielectric Disks with a Finite Scatterer in the
  THz Regime

abstract:
  In the Terahertz (THz) domain, we investigate both numerically and
experimentally the directional emission of whispering gallery mode resonators
that are perturbed by a small scatterer in the vicinity of the resonators rim.
We determine quality factor degradation, the modal structure and the emission
direction for various geometries. We find that scatterers do allow for
directional emission without destroying the resonator's quality factor. This
finding allows for new geometries and outcoupling scenarios for active
whispering gallery mode structures such as quantum cascade lasers and passive
resonators such as evanescent sensors. The experimental results agree well with
finite difference time domain simulations.


title:
Model-guided Performance Analysis of the Sparse Matrix-Matrix
  Multiplication

abstract:
  Achieving high efficiency with numerical kernels for sparse matrices is of
utmost importance, since they are part of many simulation codes and tend to use
most of the available compute time and resources. In addition, especially in
large scale simulation frameworks the readability and ease of use of
mathematical expressions are essential components for the continuous
maintenance, modification, and extension of software. In this context, the
sparse matrix-matrix multiplication is of special interest. In this paper we
thoroughly analyze the single-core performance of sparse matrix-matrix
multiplication kernels in the Blaze Smart Expression Template (SET) framework.
We develop simple models for estimating the achievable maximum performance, and
use them to assess the efficiency of our implementations. Additionally, we
compare these kernels with several commonly used SET-based C++ libraries,
which, just as Blaze, aim at combining the requirements of high performance
with an elegant user interface. For the different sparse matrix structures
considered here, we show that our implementations are competitive or faster
than those of the other SET libraries for most problem sizes on a current Intel
multicore processor.


title: Hamiltonian Formalism of General Bimetric Gravity

abstract:
  We perform the Hamiltonian analysis of general bimetric gravity. We determine
four first class constraints that are generators of the diagonal
diffeomorphism. We further analyze the remaining constraints and we present an
evidence that these constraints should be the second class constraints in order
to have theory with the Hamiltonian constraint as the first class constraint.
We also discuss the case of the non-linear bimetric gravity and argue that it
is very difficult to eliminate the ghost mode.


title:
K3 surfaces with a non-symplectic automorphism and product-quotient
  surfaces with cyclic groups

abstract:
  We classify all the K3 surfaces which are minimal models of the quotient of
the product of two curves $C_1\times C_2$ by the diagonal action of either the
group $\Z/p\Z$ or the group $\Z/2p\Z$. These K3 surfaces admit a non-symplectic
automorphism of order $p$ induced by an automorphism of one of the curves $C_1$
or $C_2$. We prove that most of the K3 surfaces admitting a non-symplectic
automorphism of order $p$ (and in fact a maximal irreducible component of the
moduli space of K3 surfaces with a non-symplectic automorphism of order $p$)
are obtained in this way.\\ In addition, we show that one can obtain the same
set of K3 surfaces under more restrictive assumptions namely one of the two
curves, say $C_2$, is isomorphic to a rigid hyperelliptic curve with an
automorphism $\delta_p$ of order $p$ and the automorphism of the K3 surface is
induced by $\delta_p$.\\ Finally, we describe the variation of the Hodge
structures of the surfaces constructed and we give an equation for some of
them.


title: A Popov Stability Condition for Uncertain Linear Quantum Systems

abstract:
  This paper considers a Popov type approach to the problem of robust stability
for a class of uncertain linear quantum systems subject to unknown
perturbations in the system Hamiltonian. A general stability result is given
for a general class of perturbations to the system Hamiltonian. Then, the
special case of a nominal linear quantum system is considered with quadratic
perturbations to the system Hamiltonian. In this case, a robust stability
condition is given in terms of a frequency domain condition which is of the
same form as the standard Popov stability condition.


title: Two cases of squares evolving by anisotropic diffusion

abstract:
  We are interested in an anisotropic singular diffusion equation in the plane
and in its regularization. We establish existence, uniqueness and basic
regularity of solutions to both equations. We construct explicit solutions
showing the creation of facets, i.e. flat regions of solutions. By using the
formula for solutions, we rigorously prove that both equations create ruled
surfaces out of convex initial conditions as well as do not admit point (local)
extrema. We present numerical experiments suggesting that the two flows seem
not differ much. Possible applications to image reconstruction is pointed out,
too.


title: Groups with infinitely many ends are not fraction groups

abstract:
  We show that any finitely generated group $F$ with infinitely many ends is
not a group of fractions of any finitely generated proper subsemigroup $P$,
that is $F$ cannot be expressed as a product $P P^{-1}$. In particular this
solves a conjecture of Navas in the positive. As a corollary we obtain a new
proof of the fact that finitely generated free groups do not admit isolated
left-invariant orderings.


title: Percolation of finite clusters and infinite surfaces

abstract:
  Two related issues are explored for bond percolation on the d-dimensional
cubic lattice (with d > 2) and its dual plaquette process. Firstly, for what
values of the parameter p does the complement of the infinite open cluster
possess an infinite component? The corresponding critical point p_fin satisfies
p_fin >= p_c, and strict inequality is proved when either d is sufficiently
large, or d >= 7 and the model is sufficiently spread out. It is not known
whether d >= 3 suffices. Secondly, for what p does there exist an infinite dual
surface of plaquettes? The associated critical point p_surf satisfies p_surf >=
p_fin.


title:
Ultra-Thin Free-Standing Single Crystalline Silicon Membranes With
  Strain Control

abstract:
  We report on fabrication and characterization of ultra-thin suspended single
crystalline flat silicon membranes with thickness down to 6 nm. We have
developed a method to control the strain in the membranes by adding a strain
compensating frame on the silicon membrane perimeter to avoid buckling of the
released membranes. We show that by changing the properties of the frame the
strain of the membrane can be tuned in controlled manner. Consequently, both
the mechanical properties and the band structure can be engineered and the
resulting membranes provide a unique laboratory to study low-dimensional
electronic, photonic and phononic phenomena.


title: Difference Sets with Few Character Values

abstract:
  The known families of difference sets can be subdivided into three classes:
difference sets with Singer parameters, cyclotomic difference sets, and
difference sets with gcd$(v,n)>1$. It is remarkable that all the known
difference sets with gcd$(v,n)>1$ have the so-called character divisibility
property. In 1997, Jungnickel and Schmidt posed the problem of constructing
difference sets with gcd$(v,n)>1$ that do not satisfy this property. In an
attempt to attack this problem, we use difference sets with three nontrivial
character values as candidates, and get some necessary conditions.


title:
On the Aharonov-Casher scattering in a CPT-odd Lorentz-violating
  background

abstract:
  The effects of a Lorentz symmetry violating background vector on the
Aharonov-Casher scattering in the nonrelativistic limit is considered. By using
the self-adjoint extension method we found that there is an additional
scattering for any value of the self-adjoint extension parameter and non-zero
energy bound states for negative values of this parameter. Expressions for the
energy bound states, phase-shift and the scattering matrix are explicitly
determined in terms of the self-adjoint extension parameter. The expression
obtained for the scattering amplitude reveals that the helicity is not
conserved in this scenario.


title: Density of orbits of semigroups of endomorphisms acting on the Adeles

abstract:
  We investigate the question of whether or not the orbit of a point in A/Q,
under the natural action of a subset S of Q, is dense in A/Q. We prove that if
the set S is a multiplicative semigroup which contains at least two
multiplicatively independent elements, one of which is an integer, then the
orbit under S of any point with irrational real coordinate is dense.


title: Cross correlations in mesoscopic charge detection

abstract:
  We study a tunnel contact that acts as charge detector for a single-electron
transistor (SET) focusing on correlations between the detector current and the
current through the SET. This system can be described fully by a Markovian
master equation for the SET, while electron tunneling in the charge monitor
represents a process with a stochastic rate, which can be solved exactly. It
turns out that current monitoring is possible as long as the detector current
correlates with the currents through either SET barrier. By contrast,
correlations with the effective current according to the Ramo-Shockley theorem
are not essential. Moreover, we propose the measurement of the SET barrier
capacitances.


title: Impact Analysis for Risks in Informatics Systems

abstract:
  In this paper are presented methods of impact analysis on informatics system
security accidents, qualitative and quantitative methods, starting with risk
and informational system security definitions. It is presented the relationship
between the risks of exploiting vulnerabilities of security system, security
level of these informatics systems, probability of exploiting the weak points
subject to financial losses of a company, respectively impact of a security
accident on the company. Herewith are presented some examples concerning losses
caused by excesses within informational systems and depicted from the study
carried out by CSI.


title: Reversible Mode Switching in Y coupled Terahertz Lasers

abstract:
  Electrically independent terahertz (THz) quantum cascade lasers (QCLs) are
optically coupled in a Y configuration. Dual frequency, electronically
switchable emission is achieved in one QCL using an aperiodic grating, designed
using computer-generated hologram techniques, incorporated directly into the
QCL waveguide by focussed ion beam milling. Multi-moded emission around 2.9 THz
is inhibited, lasing instead occurring at switchable grating-selected
frequencies of 2.88 and 2.92 THz. This photonic control and switching behaviour
is selectively and reversibly transferred to the second, unmodified QCL via
evanescent mode coupling, without the transfer of the inherent grating losses.


title:
Linear-Response Dynamics from the Time-Dependent Gutzwiller
  Approximation

abstract:
  Within a Lagrangian formalism we derive the time-dependent Gutzwiller
approximation for general multi-band Hubbard models. Our approach explicitly
incorporates the coupling between time-dependent variational parameters and a
time-dependent density matrix from which we obtain dynamical correlation
functions in the linear response regime. Our results are illustrated for the
one-band model where we show that the interacting system can be mapped to an
effective problem of fermionic quasiparticles coupled to "doublon" (double
occupancy) bosonic fluctuations. The latter have an energy on the scale of the
on-site Hubbard repulsion $U$ in the dilute limit but becomes soft at the
Brinkman-Rice transition which is shown to be related to an emerging
conservation law of doublon charge and the associated gauge invariance.
Coupling with the boson mode produces structure in the charge response and we
find that a similar structure appears in dynamical mean-field theory.


title:
Persistence of equilibrium states in an oscillating double-well
  potential

abstract:
  We investigate numerically parametrically driven coupled nonlinear
Schrodinger equations modelling the dynamics of coupled wavefields in a
periodically oscillating double-well potential. The equations describe among
other things two coupled periodically-curved optical waveguides with Kerr
nonlinearity or horizontally shaken Bose-Einstein condensates in a double-well
magnetic trap. In particular, we study the persistence of equilibrium states of
the undriven system due to the presence of the parametric drive. Using
numerical continuations of periodic orbits and calculating the corresponding
Floquet multipliers, we find that the drive can (de)stabilize a continuation of
an equilibrium state indicated by the change of the (in)stability of the orbit.
Hence, we show that parametric drives can provide a powerful control to
nonlinear (optical or matter wave) field tunneling. Analytical approximations
based on an averaging method are presented. Using perturbation theory the
influence of the drive on the symmetry breaking bifurcation point is discussed.

categories: cond-mat.quant-gas nlin.CD physics.optics quant-ph


title:
ALPRS - A New Approach for License Plate Recognition using the Sift
  Algorithm

abstract:
  This paper presents a new approach for the automatic license plate
recognition, which includes the SIFT algorithm in step to locate the plate in
the input image. In this new approach, besides the comparison of the features
obtained with the SIFT algorithm, the correspondence between the spatial
orientations and the positioning associated with the keypoints is also
observed. Afterwards, an algorithm is used for the character recognition of the
plates, very fast, which makes it possible its application in real time. The
results obtained with the proposed approach presented very good success rates,
so much for locating the characters in the input image, as for their
recognition.


title: Permanence criteria for Kolmogorov systems with delays

abstract:
  In this paper, a class of Kolmogorov systems with delays are studied.
Sufficient conditions are provided for a system to have a compact uniform
attractor. Then Jansen's result (J. Math. Biol. Vol. 25 (1987) 411-422) for
autonomous replicator and Lotka-Volterra systems has been extended to delayed
nonautonomous Kolmogorov systems with periodic or autonomous Lotka-Volterra
subsystems. Thus, simple algebraic conditions are obtained for partial
permanence and permanence. An outstanding feature of all these results is that
the conditions are irrelevant of the size and distribution of the delays.


title: Source Integrals for Multipole Moments in Static Spacetimes

abstract:
  We derive source integrals for multipole moments that describe the behavior
of static and axially symmetric spacetimes close to spatial infinity. We assume
that the matter distribution is isolated. We outline also some applications of
these source integrals of the asymptotic multipole moments.


title:
Vus from pi and K decay constants in full lattice QCD with physical u,
  d, s and c quarks

abstract:
  We determine the decay constants of the pi and K mesons on gluon field
configurations from the MILC collaboration including u, d, s and c quarks. We
use three values of the lattice spacing and u/d quark masses going down to the
physical value. We use the w_0 parameter to fix the relative lattice spacing
and f_pi to fix the overall scale. This allows us to obtain a value for
f{K^+}/f{pi^+} = 1.1916(21). Comparing to the ratio of experimental leptonic
decay rates gives |Vus| = 0.22564(28){Br(K^+)}(20){EM}(40){latt}(5){Vud} and
the test of unitarity of the first row of the Cabibbo-Kobayashi-Maskawa matrix:
|Vud|^2+|Vus|^2+|Vub|^2 - 1 = 0.00009(51).


title: Another Disjoint Compression Algorithm for OCT

abstract:
  We describe an elegant O*(2^k) algorithm for the disjoint compression problem
for Odd Cycle Transversal based on a reduction to Above Guarantee Vertex Cover.
We believe that this algorithm refines the understanding of the Odd Cycle
Transversal algorithm by Reed, Smith and Vetta.


title: A new approach for an unitary risk theory

abstract:
  The work deals with the risk assessment theory. An unitary risk algorithm is
elaborated. The algorithm is based on parallel curves. The basic curve of risk
is a hyperbolic curve, obtained as a multiplication between the probability of
occurrence of certain event and its impact. Section 1 contains the problem
formulation. Section 2 contains some specific notations and the mathematical
background of risk algorithm. A numerical application based on risk algorithm
is the content of section 3. Section 4 contains several conclusions.


title: A correction note on "New iterative schemes for nonlinear equations"

abstract:
  In Noor (2007)[Muhammad Aslam Noor, New iterative schemes for nonlinear
equations, Appl. Math. Comput. 187 (2007) 937-943], proposed an algorithm
namely \textbf{Algorithm 2.4} and established a proof to show cubic
convergence. The presented proof is wrong. In this article, we show that
\textbf{Algorithm 2.4} is not cubically convergent.


title:
Groebner basis and singular locus of Lauricella's hypergeometric
  differential equations

abstract:
  We derive Groebner bases for Lauricella's hypergeometric differential
equations $I_A(m), I_B(m), I_C(m)$ with respect to a monomial order. By using
these Groebner bases, we determine characteristic varieties and the singular
loci of $I_A(m), I_B(m), I_C(m)$.


title:
The SW Sex-type star 2MASS J01074282+4845188: an unusual bright
  accretion disk with non-steady emission and a hot white dwarf

abstract:
  We present new photometric and spectral observations of the newly discovered
nova-like eclipsing star 2MASS J01074282+4845188. To obtain a light curve
solution we used model of a nova-like star whose emission sources are a white
dwarf surrounded by an accretion disk, a secondary star filling its Roche lobe,
a hot spot and a hot line. 2MASS J01074282+4845188 shows the deepest permanent
eclipse among the known nova-like stars. It is reproduced by covering the very
bright accretion disk by the secondary component. The luminosity of the disk is
much bigger than that of the rest light sources. The determined high
temperature of the disk is typical for that observed during the outbursts of
CVs. The primary of 2MASS J01074282+4845188 is one of the hottest white dwarfs
in CVs. The temperature of 5090 K of its secondary is also quite high and more
appropriate for a long-period SW Sex star. It might be explained by the intense
heating from the hot white dwarf and the hot accretion disk of the target. The
high mass accretion rate $\dot{M} = 8\times 10^{-9} M_{\sun}$ yr$^{-1}$, the
broad and single-peaked H$\alpha$ emission profile, and the presence of an
S-wave are sure signs for the SW Sex classification of 2MASS J01074282+4845188.
The obtained flat temperature distribution along the disk radius as well as the
deviation of the energy distribution from the black-body law are evidence of
the non-steady emission of the disk. The close values of the disk temperature
and the parameter $\alpha_{g}$ of 2MASS J01074282+4845188 and those of the
cataclysmic stars at eruptions might be considered as an additional argument
for the permanent active state of nova-like stars.


title: Minimal zero-sum sequences of length five over finite cyclic groups

abstract:
  Let $G$ be a finite cyclic group. Every sequence $S$ of length $l$ over $G$
can be written in the form $S=(n_1g)\cdot\ldots\cdot(n_lg)$ where $g\in G$ and
$n_1, \ldots, n_l\in[1, \ord(g)]$, and the index $\ind(S)$ of $S$ is defined to
be the minimum of $(n_1+\cdots+n_l)/\ord(g)$ over all possible $g\in G$ such
that $\langle g \rangle =G$. In this paper, we determine the index of any
minimal zero-sum sequence $S$ of length 5 when $G=\langle g\rangle$ is a cyclic
group of a prime order and $S$ has the form $S=g^2(n_2g)(n_3g)(n_4g)$. It is
shown that if $G=\langle g\rangle$ is a cyclic group of prime order $p \geq
31$, then every minimal zero-sum sequence $S$ of the above mentioned form has
index 1 except in the case that
$S=g^2(\frac{p-1}{2}g)(\frac{p+3}{2}g)((p-3)g)$.


title:
Longitudinal magnetoresistance in Co-doped BaFe2As2 and LiFeAs single
  crystals: Interplay between spin fluctuations and charge transport in
  iron-pnictides

abstract:
  The longitudinal in-plane magnetoresistance (LMR) has been measured in
different Ba(Fe_(1-x)Co_x)2As2 single crystals and in LiFeAs. For all these
compounds, we find a negative LMR in the paramagnetic phase whose magnitude
increases as H^2. We show that this negative LMR can be readily explained in
terms of suppression of the spin fluctuations by the magnetic field. In the
Co-doped samples, the absolute value of the LMR coefficient is found to
decrease with doping content in the paramagnetic phase. The analysis of its T
dependence in an itinerant nearly antiferromagnetic Fermi liquid model
evidences that the LMR displays a qualitative change of T variation with
increasing Co content. The latter occurs at optimal doping for which the
antiferromagnetic ground state is suppressed. The same type of analysis for the
negative LMR measured in LiFeAs suggests that this compound is on the verge of
magnetism.


title:
Reproduction of Exponential Polynomials by Multivariate Non-stationary
  Subdivision Schemes with a General Dilation Matrix

abstract:
  We study scalar multivariate non-stationary subdivision schemes with a
general dilation matrix. We characterize the capability of such schemes to
reproduce exponential polynomials in terms of simple algebraic conditions on
their symbols. These algebraic conditions provide a useful theoretical tool for
checking the reproduction properties of existing schemes and for constructing
new schemes with desired reproduction capabilities and other enhanced
properties. We illustrate our results with several examples.


title:
The Molecule Calculator: A web-server for fast quantum mechanics-based
  estimation of molecular properties

abstract:
  A new web-server called The Molecule Calculator (MolCalc) is presented. The
entry page is a molecular editor (JSmol) for interactive molecule building. The
resulting structure can then be used to estimate molecular properties such as
heats of formation and other thermodynamic properties, vibrational frequencies
and vibrational modes, and molecular orbitals and orbital energies. These
properties are computed using the GAMESS program at either the RHF/STO-3G
(orbitals and orbital energies) or PM3 level of theory (all other properties)
in a matter of seconds or minutes depending on the size of the molecule. The
results, though approximate, can help students develop a "chemical intuition"
about how molecular structure affects molecular properties, without performing
the underlying calculations by hand, a near impossible task for all but the
simplest chemical systems.


title:
Influence of the deposition conditions on the field emission properties
  of patterned nitrogenated carbon nanotube films

abstract:
  The electron field emission of patterned films of nitrogenated carbon
nanotubes is shown to be decisively influenced by the deposition conditions.
The growth was carried out by decomposing methane in a nitrogen/ammonia
atmosphere using hot filament chemical vapor deposition (CVD). The diameter of
the produced tubes depended critically on the distance between substrate and
filament, and the field emission properties applied fields needed for electron
emission, field amplification factor) could be directly correlated to the film
morphology. This demonstrates the possibility of tuning the field emission
properties of such film emitters. For arrays of nanotubes thinner than 50 nm,
the onset of field emission was observed at about 4 V/um, and a current density
of 10 mA/cm2 was obtained for an applied field of 7.2 V/um.


title: Open issues in neutrino astrophysics

abstract:
  Neutrinos of astrophysical origin are messengers produced in stars, in
explosive phenomena like core-collapse supernovae, in the accretion disks
around black holes, or in the Earth's atmosphere. Their fluxes and spectra
encode information on the environments that produce them. Such fluxes are
modified in characteristic ways when neutrinos traverse a medium. Here our
current understanding of neutrino flavour conversion in media is summarized.
The importance of this domain for astrophysical observations is emphasized.
Examples are given of the fundamental properties that astrophysical neutrinos
have uncovered, or might reveal in the future.


title: Minimal zero-sum sequences of length four over finite cyclic groups II

abstract:
  Let $G$ be a finite cyclic group. Every sequence $S$ over $G$ can be written
in the form $S=(n_1g)\cdot\ldots\cdot(n_lg)$ where $g\in G$ and $n_1, \ldots,
n_l\in[1, \ord(g)]$, and the index $\ind(S)$ of $S$ is defined to be the
minimum of $(n_1+\cdots+n_l)/\ord(g)$ over all possible $g\in G$ such that
$\langle g \rangle =G$. An open problem on the index of length four sequences
asks whether or not every minimal zero-sum sequence of length 4 over a finite
cyclic group $G$ with $\gcd(|G|, 6)=1$ has index 1. In this paper, we show that
if $G=\langle g\rangle$ is a cyclic group with order of a product of two prime
powers and $\gcd(|G|, 6)=1$, then every minimal zero-sum sequence $S$ of the
form $S=(g)(n_2g)(n_3g)(n_4g)$ has index 1. In particular, our result confirms
that the above problem has an affirmative answer when the order of $G$ is a
product of two different prime numbers or a prime power, extending a recent
result by the first author, Plyley, Yuan and Zeng.


title: Mode Competition in Dual-Mode Quantum Dots Semiconductor Microlaser

abstract:
  This paper describes the modeling of quantum dots lasers with the aim of
assessing the conditions for stable cw dual-mode operation when the mode
separation lies in the THz range. Several possible models suited for InAs
quantum dots in InP barriers are analytically evaluated, in particular quantum
dots electrically coupled through a direct exchange of excitation by the
wetting layer or quantum dots optically coupled through the homogeneous
broadening of their optical gain. A stable dual-mode regime is shown possible
in all cases when quantum dots are used as active layer whereas a gain medium
of quantum well or bulk type inevitably leads to bistable behavior. The choice
of a quantum dots gain medium perfectly matched the production of dual-mode
lasers devoted to THz generation by photomixing.


title:
Ptolemy diagrams and torsion pairs in the cluster categories of Dynkin
  type D

abstract:
  We give a complete classification of torsion pairs in the cluster category of
Dynkin type D_n, via a bijection to new combinatorial objects called Ptolemy
diagrams of type D. For the latter we give along the way different
combinatorial descriptions. One of these allows us to count the number of
torsion pairs in the cluster category of type D_n by providing their generating
function explicitly.


title: The many faces of the Kempner number

abstract:
  In this survey, we present five different proofs for the transcendence of
Kempner's number, defined by the infinite series $\sum_{n=0}^{\infty}
\frac{1}{2^{2^n}}$. We take the opportunity to mention some interesting ideas
and methods that are used for proving deeper results. We outline proofs for
some of these results and also point out references where the reader can find
all the details.


title: Evolution of the Water Maser Expanding Shell in W75N VLA 2

abstract:
  We present Very Long Baseline Interferometry (VLBI) observations of 22 GHz
H$_2$O masers in the high-mass star-forming region of \objectname{W75N},
carried out with VLBI Exploration of Radio Astrometry (VERA) for three-epochs
in 2007 with an angular resolution of $\sim$ 1 mas. We detected H$_2$O maser
emission toward the radio jet in VLA 1 and the expanding shell-like structure
in VLA 2. We have made elliptical fits to the VLA 2 H$_2$O maser shell-like
structure observed in the different epochs (1999, 2005, and 2007), and found
that the shell is still expanding eight years after its discovery. From the
difference in the size of the semi-major axes of the fitted ellipses in the
epochs 1999 ($\simeq$ 71$\pm$1 mas), 2005 ($\simeq$ 97$\pm$3 mas), and 2007
($\simeq$ 111$\pm$1 mas), we estimate an average expanding velocity of $\sim$ 5
mas yr$^{-1}$, similar to the proper motions measured in the individual H$_2$O
maser features. A kinematic age of $\sim$ 20 yr is derived for this structure.
In addition, our VERA observations indicate an increase in the ellipticity of
the expanding shell around VLA 2 from epochs 1999 to 2007. In fact, the
elliptical fit of the VERA data shows a ratio between the minor and major axes
of $\sim$ 0.6, in contrast with a most circular shape for the shell detected in
1999 and 2005 (b/a $\sim$ 0.9). This suggests that we are probably observing
the formation of a jet-driven H$_2$O maser structure in VLA2, evolving from a
non-collimated pulsed-outflow event during the first stages of evolution of a
massive young stellar object (YSO). This may support predictions made earlier
by other authors on this issue, consistent with recent magnetohydrodynamical
simulations. We discuss possible implications of our results in the study of
the first stages of evolution of massive YSOs.


title: Quantum states of the bouncing universe

abstract:
  In this paper we study quantum dynamics of the bouncing cosmological model.
We focus on the model of the flat Friedman-Robertson-Walker universe with a
free scalar field. The bouncing behavior, which replaces classical singularity,
appears due to the modification of general relativity along the methods of loop
quantum cosmology. We show that there exist a unitary transformation that
enables to describe the system as a free particle with Hamiltonian equal to
canonical momentum. We examine properties of the various quantum states of the
Universe: boxcar state, standard coherent state, and soliton-like state, as
well as Schr{\"o}dinger's cat states constructed from these states.
Characteristics of the states such as quantum moments and Wigner functions are
investigated. We show that each of these states have, for some range of
parameters, a proper semiclassical limit fulfilling the correspondence
principle. Decoherence of the superposition of two universes is described and
possible interpretations in terms of triad orientation and
Belinsky-Khalatnikov-Lifshitz conjecture are given. Some interesting features
regarding the area of the negative part of the Wigner function have emerged.


title:
Precise Measurements of Primordial Power Spectrum with 21 cm
  Fluctuations

abstract:
  We discuss the issue of how precisely we can measure the primordial power
spectrum by using future observations of 21 cm fluctuations and cosmic
microwave background (CMB). For this purpose, we investigate projected
constraints on the quantities characterizing primordial power spectrum: the
spectral index n_s, its running alpha_s and even its higher order running
beta_s. We show that future 21 cm observations in combinations with CMB would
accurately measure above mentioned observables of primordial power spectrum. We
also discuss its implications to some explicit inflationary models.


title:
The period ratio for standing kink and sausage modes in solar structures
  with siphon flow. I. magnetized slabs

abstract:
  In the applications of solar magneto-seismology(SMS), employing the ratio of
the period of the fundamental mode to twice the one of its first overtone,
$P_1/2P_2$, plays an important role. We examine how field-aligned flows affect
the dispersion properties, and hence the period ratios, of standing modes
supported by magnetic slabs in the solar atmosphere. We numerically solve the
dispersion relations and devise a graphic means to construct standing modes.
For coronal slabs, we find that the flow effects are significant, for the fast
kink and sausage modes alike. For the kink ones, they may reduce $P_1/2P_2$ by
up to 23% compared with the static case, and the minimum allowed $P_1/2P_2$ can
fall below the lower limit analytically derived for static slabs. For the
sausage modes, while introducing the flow reduces $P_1/2P_2$ by typically
$\lesssim 5$ % relative to the static case, it significantly increases the
threshold aspect ratio only above which standing sausage modes can be
supported, meaning that their detectability is restricted to even wider slabs.
In the case of photospheric slabs, the flow effect is not as strong. However,
standing modes are distinct from the coronal case in that standing kink modes
show a $P_1/2P_2$ that deviates from unity even for a zero-width slab, while
standing sausage modes no longer suffer from a threshold aspect ratio. We
conclude that transverse structuring in plasma density and flow speed should be
considered in seismological applications of multiple periodicities to solar
atmospheric structures.


title: Coherence and elicitability

abstract:
  The risk of a financial position is usually summarized by a risk measure. As
this risk measure has to be estimated from historical data, it is important to
be able to verify and compare competing estimation procedures. In statistical
decision theory, risk measures for which such verification and comparison is
possible, are called elicitable. It is known that quantile based risk measures
such as value at risk are elicitable. In this paper we show that law-invariant
spectral risk measures such as expected shortfall are not elicitable unless
they reduce to minus the expected value. Hence, it is unclear how to perform
forecast verification or comparison. However, the class of elicitable
law-invariant coherent risk measures does not reduce to minus the expected
value. We show that it consists of certain expectiles.


title:
False-Name Manipulation in Weighted Voting Games is Hard for
  Probabilistic Polynomial Time

abstract:
  False-name manipulation refers to the question of whether a player in a
weighted voting game can increase her power by splitting into several players
and distributing her weight among these false identities. Analogously to this
splitting problem, the beneficial merging problem asks whether a coalition of
players can increase their power in a weighted voting game by merging their
weights. Aziz et al. [ABEP11] analyze the problem of whether merging or
splitting players in weighted voting games is beneficial in terms of the
Shapley-Shubik and the normalized Banzhaf index, and so do Rey and Rothe [RR10]
for the probabilistic Banzhaf index. All these results provide merely
NP-hardness lower bounds for these problems, leaving the question about their
exact complexity open. For the Shapley--Shubik and the probabilistic Banzhaf
index, we raise these lower bounds to hardness for PP, "probabilistic
polynomial time", and provide matching upper bounds for beneficial merging and,
whenever the number of false identities is fixed, also for beneficial
splitting, thus resolving previous conjectures in the affirmative. It follows
from our results that beneficial merging and splitting for these two power
indices cannot be solved in NP, unless the polynomial hierarchy collapses,
which is considered highly unlikely.


title:
Thickness dependence of the degree of spin polarization of the
  electrical current in permalloy thin films

abstract:
  Spin-polarized electrical transport is investigated in $
Al_{2}O_{3}/Ni_{80}Fe_{20}/Al_{2}O_{3}$ thin films for permalloy thickness
between 6 and 20nm. The degree of spin-polarization of the current flowing in
the plane of the film is measured through the current induced spin wave Doppler
shift. We find that it decreases as the film thickness decreases, from 0.72 at
20nm to 0.46 at 6nm. This decrease is attributed to a spin depolarization
induced by the film surfaces. A model is proposed which takes into account the
contributions of the different sources of electron scattering (alloy disorder,
phonons, thermal magnons, grain boundaries, film surfaces) to the measured
spin-dependent resistivities.


title:
Joint Wireless Information and Energy Transfer in a Two-User MIMO
  Interference Channel

abstract:
  This paper investigates joint wireless information and energy transfer in a
two-user MIMO interference channel, in which each receiver either decodes the
incoming information data (information decoding, ID) or harvests the RF energy
(energy harvesting, EH) to operate with a potentially perpetual energy supply.
In the two-user interference channel, we have four different scenarios
according to the receiver mode -- ($ID_1$, $ID_2$), ($EH_1$, $EH_2$), ($EH_1$,
$ID_2$), and ($ID_1$, $EH_2$). While the maximum information bit rate is
unknown and finding the optimal transmission strategy is still open for
($ID_1$, $ID_2$), we have derived the optimal transmission strategy achieving
the maximum harvested energy for ($EH_1$, $EH_2$). For ($EH_1$, $ID_2$), and
($ID_1$, $EH_2$), we find a necessary condition of the optimal transmission
strategy and, accordingly, identify the achievable rate-energy (R-E) tradeoff
region for two transmission strategies that satisfy the necessary condition -
maximum energy beamforming (MEB) and minimum leakage beamforming (MLB).
Furthermore, a new transmission strategy satisfying the necessary condition -
signal-to-leakage-and-energy ratio (SLER) maximization beamforming - is
proposed and shown to exhibit a better R-E region than the MEB and the MLB
strategies. Finally, we propose a mode scheduling method to switch between
($EH_1$, $ID_2$) and ($ID_1$, $EH_2$) based on the SLER.