title:
Photoionization of hydrogen atom by coherent intense high-frequency
  short laser pulses: Direct propagation of electron wave packets on large
  spatial grids

abstract:
  The time-dependent Schr\"{o}dinger equation for the hydrogen atom and its
interaction with coherent intense high-frequency short laser pulses is solved
numerically exactly by propagating the single-electron wave packets. Thereby,
the wavefunction is followed in space and time for times longer than the pulse
duration. Results are explicitly shown for 3 and 10 fs pulses. Particular
attention is paid to identifying the effect of dynamic interference of
photoelectrons emitted with the same kinetic energy at different times during
the rising and falling sides of the pulse predicted in [\emph{Ph.V. Demekhin
and L.S. Cederbaum}, Phys. Rev. Lett. \textbf{108}, 253001 (2012)]. In order to
be able to see the dynamic interference pattern in the computed electron
spectra, the photoelectron wave packet has to be propagated over long
distances. Clearly, complex absorption potentials often employed to compute
spectra of emitted particles cannot be used to detect dynamic interference. For
the considered high-frequency pulses of 3 and 10 fs durations, this requires
enormously large spatial grids. The presently computed photoionization and
above-threshold ionization spectra are found to exhibit pronounced dynamic
interference patterns. Where available, the patterns are in very good agreement
with previously published results on the photoionization spectra which have
been computed using a completely different method, thus supporting the
previously made assumption that the above-threshold ionization processes are
very weak for the considered pulse intensities and high carrier frequency. The
quiver motion in space and time of a free electron in strong laser pulses is
also investigated numerically. Finally, a discussion is presented of how fast
the atom is ionized by an intense pulse.


title: Simplifying Multiple Sums in Difference Fields

abstract:
  In this survey article we present difference field algorithms for symbolic
summation. Special emphasize is put on new aspects in how the summation
problems are rephrased in terms of difference fields, how the problems are
solved there, and how the derived results in the given difference field can be
reinterpreted as solutions of the input problem. The algorithms are illustrated
with the Mathematica package \SigmaP\ by discovering and proving new harmonic
number identities extending those from (Paule and Schneider, 2003). In
addition, the newly developed package \texttt{EvaluateMultiSums} is introduced
that combines the presented tools. In this way, large scale summation problems
for the evaluation of Feynman diagrams in QCD (Quantum ChromoDynamics) can be
solved completely automatically.


title: Nondispersive decay for the cubic wave equation

abstract:
  We consider the hyperboloidal initial value problem for the cubic focusing
wave equation. Without symmetry assumptions, we prove the existence of a
co-dimension 4 Lipschitz manifold of initial data that lead to global solutions
in forward time which do not scatter to free waves.


title:
Frustrated quantum Heisenberg antiferromagnets at high magnetic fields:
  Beyond the flat-band scenario

abstract:
  We consider the spin-1/2 antiferromagnetic Heisenberg model on three
frustrated lattices (the diamond chain, the dimer-plaquette chain and the
two-dimensional square-kagome lattice) with almost dispersionless lowest magnon
band. Eliminating high-energy degrees of freedom at high magnetic fields, we
construct low-energy effective Hamiltonians which are much simpler than the
initial ones. These effective Hamiltonians allow a more extended analytical and
numerical analysis. In addition to the standard strong-coupling perturbation
theory we also use a localized-magnon based approach leading to a substantial
improvement of the strong-coupling approximation. We perform extensive exact
diagonalization calculations to check the quality of different effective
Hamiltonians by comparison with the initial models. Based on the
effective-model description we examine the low-temperature properties of the
considered frustrated quantum Heisenberg antiferromagnets in the high-field
regime. We also apply our approach to explore thermodynamic properties for a
generalized diamond spin chain model suitable to describe azurite at high
magnetic fields. Interesting features of these highly frustrated spin models
consist in a steep increase of the entropy at very small temperatures and a
characteristic extra low-temperature peak in the specific heat. The most
prominent effect is the existence of a magnetic-field driven
Berezinskii-Kosterlitz-Thouless phase transition occurring in the
two-dimensional model.


title: Group Evolution Discovery in Social Networks

abstract:
  Group extraction and their evolution are among the topics which arouse the
greatest interest in the domain of social network analysis. However, while the
grouping methods in social networks are developed very dynamically, the methods
of group evolution discovery and analysis are still uncharted territory on the
social network analysis map. Therefore the new method for the group evolution
discovery called GED is proposed in this paper. Additionally, the results of
the first experiments on the email based social network together with
comparison with two other methods of group evolution discovery are presented.


title:
Equivalence between Born-Infeld tachyon and effective real scalar field
  theories for brane structures in warped geometry

abstract:
  An equivalence between Born-Infeld and effective real scalar field theories
for brane structures is built in some specific warped space-time scenarios.
Once the equations of motion for tachyon fields related to the Born-Infeld
action are written as first-order equations, a simple analytical connection
with a particular class of real scalar field superpotentials can be found. This
equivalence leads to the conclusion that, for a certain class of
superpotentials, both systems can support identical thick brane solutions as
well as brane structures described through localized energy densities,
$T_{00}(y)$, in the $5^{th}$ dimension, $y$. Our results indicate that thick
brane solutions realized by the Born-Infeld cosmology can be connected to real
scalar field brane scenarios which can be used to effectively map the tachyon
condensation mechanism.


title:
Near-field focusing of dielectric microspheres: Super-resolution and
  field-invariant parameter scaling

abstract:
  Optical near-fields of small dielectric particles are of particular
importance and interests for nanoscale optical engineering such as field
localization, fabrication, characterization, sensing and imaging. This paper
represents a systematic investigation on the focusing characteristics (focal
length, field enhancement, spot size) for a given refractive-index microsphere
(n=1.6) with a varying size parameter across the range of pi<q0<20*pi.
Conditions for super-resolution foci were analysised in details. Particularly
strong super-resolution foci with spot size falling at least 50% below the
diffraction limit were identified and possible new applications were suggested.
To understand how the super-resolution conditions could be scaled to other
refractive-index particles or background medium, principles of field-invariant
parameters scaling (size, wavelength, and refractive index) were revealed and
demonstrated with example cases. It offers the new freedom to choose particles
and background medium to gain super-resolution at any frequency across the
whole electromagnetic spectrum.


title: Compact Operators in Regular LCQ Groups

abstract:
  We show that a regular locally compact quantum group $\mathbb{G}$ is discrete
if and only if $L^\infty(\mathbb{G})$ contains non-zero compact operators on
$L^2(\mathbb{G})$. As a corollary we classify all discrete quantum groups among
regular locally compact quantum groups $\mathbb{G}$ where $L^1(\mathbb{G})$ has
the Radon--Nikodym property.


title:
Exclusion of exotic top-like quarks with -4/3 electric charge using
  jet-charge tagging in single-lepton ttbar events at CDF

abstract:
  We report on a measurement of the top-quark electric charge in ttbar events
in which one W boson originating from the top-quark pair decays into leptons
and the other into hadrons. The event sample was collected by the CDF II
detector in sqrt(s)=1.96 TeV proton-antiproton collisions and corresponds to
5.6 fb^(-1). We find the data to be consistent with the standard model and
exclude the existence of an exotic quark with -4/3 electric charge and mass of
the conventional top quark at the 99% confidence level.


title:
Representation of left centralizers for actions of locally compact
  quantum groups

abstract:
  We generalize the representation theorem of Junge, Neufang and Ruan [A
representation theorem for locally compact quantum groups, Internat. J. Math.
20(3) (2009) 377-400], and some of the important results which were used in its
proof, to the case of actions of locally compact quantum groups on von Neumann
algebras.


title:
Chemical compass model for avian magnetoreception as a quantum coherent
  device

abstract:
  It is known that more than 50 species use the Earth's magnetic field for
orientation and navigation. Intensive studies particularly behavior experiments
with birds, provide support for a chemical compass based on magnetically
sensitive free radical reactions as a source of this sense. However, the
fundamental question of how quantum coherence plays an essential role in such a
chemical compass model of avian magnetoreception yet remains controversial.
Here, we show that the essence of the chemical compass model can be understood
in analogy to a quantum interferometer exploiting global quantum coherence
rather than any subsystem coherence. Within the framework of quantum metrology,
we quantify global quantum coherence and correlate it with the function of
chemical magnetoreception. Our results allow us to understand and predict how
various factors can affect the performance of a chemical compass from the
unique perspective of quantum coherence assisted metrology. This represents a
crucial step to affirm a direct connection between quantum coherence and the
function of a chemical compass.


title:
Multiperiodicity, modulations and flip-flops in variable star light
  curves II. Analysis of II Peg photometry during 1979-2010

abstract:
  According to earlier Doppler images of the magnetically active primary giant
component of the RS CVn binary II Peg, the surface of the star was dominated by
one single active longitude that was clearly drifting in the rotational frame
of the binary system during 1994-2002; later imaging for 2004-2010, however,
showed decreased and chaotic spot activity, with no signs of the drift pattern.
Here we set out to investigate from a more extensive photometric dataset
whether such a drift is a persistent phenomenon, in which case it could be due
to either an azimuthal dynamo wave or an indication of the binary system
orbital synchronization still being incomplete. We analyse the datasets using
the Carrier Fit method (hereafter CF), especially suitable for analyzing time
series in which a fast clocking frequency (such as the rotation of the star) is
modulated with a slower process (such as the stellar activity cycle). We
combine all collected photometric data into one single data set, and analyze it
with the CF method. As a result, we confirm the earlier results of the spot
activity having been dominated by one primary spotted region almost through the
entire data set, and the existence of a persistent, nearly linear drift.
Disruptions of the linear trend and complicated phase behavior are also seen,
but the period analysis reveals a rather stable periodicity with
P(spot)=6.71054d plus/minus 0.00005d. After the linear trend is removed from
the data, we identify several abrupt phase jumps, three of which are analyzed
in more detail with the CF method. These phase jumps closely resemble what is
called flip-flop event, but the new spot configurations do not, in most cases,
persist for longer than a few months.


title: The Strauss conjecture on Kerr black hole backgrounds

abstract:
  We examine solutions to semilinear wave equations on black hole backgrounds
and give a proof of an analog of the Strauss conjecture on the Schwarzschild
and Kerr, with small angular momentum, black hole backgrounds. The key
estimates are a class of weighted Strichartz estimates, which are used near
infinity where the metrics can be viewed as small perturbations of the
Minkowski metric, and a localized energy estimate on the black hole background,
which handles the behavior in the remaining compact set.


title: Critical scaling in random-field systems: 2 or 3 independent exponents?

abstract:
  We show that the critical scaling behavior of random-field systems with
short-range interactions and disorder correlations cannot be described in
general by only two independent exponents, contrary to previous claims. This
conclusion is based on a theoretical description of the whole (d,N) domain of
the d-dimensional random-field O(N) model and points to the role of rare events
that are overlooked by the proposed derivations of two-exponent scaling. Quite
strikingly, however, the numerical estimates of the critical exponents of the
random field Ising model are extremely close to the predictions of the
two-exponent scaling, so that the issue cannot be decided on the basis of
numerical simulations.


title: Convexity is a local property in $CAT(\kappa)$ spaces

abstract:
  In this note we show that a connected, closed and locally convex subset (with
an extra assumption on the diameter with respect to the induced length metric
if $\kappa>0$) of a $CAT(\kappa)$ space is convex.


title: On the Tidal Dissipation of Obliquity

abstract:
  We investigate tidal dissipation of obliquity in hot Jupiters. Assuming an
initial random orientation of obliquity and parameters relevant to the observed
population, the obliquity of hot Jupiters does not evolve to purely aligned
systems. In fact, the obliquity evolves to either prograde, retrograde or
90^{o} orbits where the torque due to tidal perturbations vanishes. This
distribution is incompatible with observations which show that hot jupiters
around cool stars are generally aligned. This calls into question the viability
of tidal dissipation as the mechanism for obliquity alignment of hot Jupiters
around cool stars.


title: Bloch oscillations of a soliton in a molecular chain

abstract:
  The paper presents results of numerical experiments simulating Bloch
oscillations of solitons in a deformable molecular chain in a constant electric
field. By the example of a homogeneous polynucleotide chain it is shown that
the system under consideration can demonstrate complicated dynamical regimes
when at the field intensities less than a certain critical value, a soliton as
a whole exhibits oscillations, while at the field intensities exceeding the
threshold, a soliton turns to a breather which oscillates. It is shown that the
motion of a charge in a deformable chain is infinite as contrasted to that in a
rigid chain.


title: Graph Logics with Rational Relations

abstract:
  We investigate some basic questions about the interaction of regular and
rational relations on words. The primary motivation comes from the study of
logics for querying graph topology, which have recently found numerous
applications. Such logics use conditions on paths expressed by regular
languages and relations, but they often need to be extended by rational
relations such as subword or subsequence. Evaluating formulae in such extended
graph logics boils down to checking nonemptiness of the intersection of
rational relations with regular or recognizable relations (or, more generally,
to the generalized intersection problem, asking whether some projections of a
regular relation have a nonempty intersection with a given rational relation).
  We prove that for several basic and commonly used rational relations, the
intersection problem with regular relations is either undecidable (e.g., for
subword or suffix, and some generalizations), or decidable with
non-primitive-recursive complexity (e.g., for subsequence and its
generalizations). These results are used to rule out many classes of graph
logics that freely combine regular and rational relations, as well as to
provide the simplest problem related to verifying lossy channel systems that
has non-primitive-recursive complexity. We then prove a dichotomy result for
logics combining regular conditions on individual paths and rational relations
on paths, by showing that the syntactic form of formulae classifies them into
either efficiently checkable or undecidable cases. We also give examples of
rational relations for which such logics are decidable even without syntactic
restrictions.


title:
Graphical Methods for Defense Against False-data Injection Attacks on
  Power System State Estimation

abstract:
  The normal operation of power system relies on accurate state estimation that
faithfully reflects the physical aspects of the electrical power grids.
However, recent research shows that carefully synthesized false-data injection
attacks can bypass the security system and introduce arbitrary errors to state
estimates. In this paper, we use graphical methods to study defending
mechanisms against false-data injection attacks on power system state
estimation. By securing carefully selected meter measurements, no false data
injection attack can be launched to compromise any set of state variables. We
characterize the optimal protection problem, which protects the state variables
with minimum number of measurements, as a variant Steiner tree problem in a
graph. Based on the graphical characterization, we propose both exact and
reduced-complexity approximation algorithms. In particular, we show that the
proposed tree-pruning based approximation algorithm significantly reduces
computational complexity, while yielding negligible performance degradation
compared with the optimal algorithms. The advantageous performance of the
proposed defending mechanisms is verified in IEEE standard power system
testcases.


title:
Tensor models from the viewpoint of matrix models: the case of loop
  models on random surfaces

abstract:
  We study a connection between random tensors and random matrices through
$U(\tau)$ matrix models which generate fully packed, oriented loops on random
surfaces. The latter are found to be in bijection with a set of regular
edge-colored graphs typically found in tensor models. It is shown that the
expansion in the number of loops is organized like the 1/N expansion of
rank-three tensor models. Recent results on tensor models are reviewed and
applied in this context. For example, configurations which maximize the number
of loops are precisely the melonic graphs of tensor models and a scaling limit
which projects onto the melonic sector is found. We also reinterpret the double
scaling limit of tensor models from the point of view of loops on random
surfaces. This approach is eventually generalized to higher-rank tensor models,
which generate loops with fugacity $\tau$ on triangulations in dimension $d-1$.

categories: hep-th cond-mat.stat-mech math-ph math.MP


title: The First Fermi-LAT Catalog of Sources Above 10 GeV

abstract:
  We present a catalog of gamma-ray sources at energies above 10 GeV based on
data from the Large Area Telescope (LAT) accumulated during the first 3 years
of the Fermi Gamma-ray Space Telescope mission. This catalog complements the
Second Fermi-LAT Catalog, which was based on 2 years of data extending down to
100 MeV and so included many sources with softer spectra below 10 GeV. The
First Fermi-LAT Catalog of >10 GeV sources (1FHL) has 514 sources, and includes
their locations, spectra, a measure of their variability, and associations with
cataloged sources at other wavelengths. We found that 449 (87%) could be
associated with known sources, of which 393 (76% of the 1FHL sources) are
active galactic nuclei. We also highlight the subset of the 1FHL sources that
are the best candidates for detection at energies above 50 GeV with
ground-based gamma-ray observatories.


title:
A hard thermal loop benchmark for the extraction of the nonperturbative
  $Q\bar{Q}$ potential

abstract:
  The extraction of the finite temperature heavy quark potential from lattice
QCD relies on a spectral analysis of the Wilson loop. General arguments tell us
that the lowest lying spectral peak encodes, through its position and shape,
the real and imaginary part of this complex potential. Here we benchmark this
extraction strategy using leading order hard-thermal loop (HTL) calculations.
I.e. we analytically calculate the Wilson loop and determine the corresponding
spectrum. By fitting its lowest lying peak we obtain the real- and imaginary
part and confirm that the knowledge of the lowest peak alone is sufficient for
obtaining the potential. Access to the full spectrum allows an investigation of
spectral features that do not contribute to the potential but can pose a
challenge to numerical attempts of an analytic continuation from imaginary time
data. Differences in these contributions between the Wilson loop and gauge
fixed Wilson line correlators are discussed. To better understand the
difficulties in a numerical extraction we deploy the Maximum Entropy method
with extended search space to HTL correlators in Euclidean time and observe how
well the known spectral function and values for the real and imaginary part are
reproduced. Possible venues for improvement of the extraction strategy are
discussed.


title: Signatures of nonlinear cavity optomechanics in the weak coupling regime

abstract:
  We identify signatures of the intrinsic nonlinear interaction between light
and mechanical motion in cavity optomechanical systems. These signatures are
observable even when the cavity linewidth exceeds the optomechanical coupling
rate. A strong laser drive red-detuned by twice the mechanical frequency from
the cavity resonance frequency makes two-phonon processes resonant, which leads
to a nonlinear version of optomechanically induced transparency. This effect
provides a new method of measuring the average phonon number of the mechanical
oscillator. Furthermore, we show that if the strong laser drive is detuned by
half the mechanical frequency, optomechanically induced transparency also
occurs due to resonant two-photon processes. The cavity response to a second
probe drive is in this case nonlinear in the probe power. These effects should
be observable with optomechanical coupling strengths that have already been
realized in experiments.


title:
Non-parametric resampling of random walks for spectral network
  clustering

abstract:
  Parametric resampling schemes have been recently introduced in complex
network analysis with the aim of assessing the statistical significance of
graph clustering and the robustness of community partitions. We propose here a
method to replicate structural features of complex networks based on the
non-parametric resampling of the transition matrix associated with an unbiased
random walk on the graph. We test this bootstrapping technique on synthetic and
real-world modular networks and we show that the ensemble of replicates
obtained through resampling can be used to improve the performance of standard
spectral algorithms for community detection.


title: Atomistic modeling of dynamical quantum transport

abstract:
  We present dynamical transport calculations based on a tight-binding
approximation to adiabatic time-dependent density functional theory (TD-DFTB).
The reduced device density matrix is propagated through the Liouville-von
Neumann equation. For the model system, 1,4-benzenediol coupled to aluminum
leads, we are able to confirm the equality of the steady state current
resulting from a time-dependent calculation to a static calculation in the
conventional Landauer framework. We also investigate the response of the
junction subjected to alternating bias voltages with frequencies up to the
optical regime. Here we can clearly identify capacitive behaviour of the
molecular device and a significant resonant enhancement of the conductance. The
results are interpreted using an analytical single level model comparing the
device transmission and admittance. In order to aid future calculations under
alternating bias, we shortly review the use of Fourier transform techniques to
obtain the full frequency response of the device from a single current trace.


title: Hydrodynamic Correlations slow down Crystallization of Soft Colloids

abstract:
  Crystallization is often assumed to be a quasi-static process that is
unaffected by details of particle transport other than the bulk diffusion
coefficient. Therefore colloidal suspensions are frequently argued to be an
ideal toy model for experimentally more difficult systems such as metal melts.
In this letter, we want to challenge this assumption. To this aim, we have
considered molecular dynamics simulations of the crystallization in a
suspension of Yukawa-type colloids. In order to investigate the role of
hydrodynamic interactions (HIs) mediated by the solvent, we modeled the solvent
both implicitly and explicitly, using Langevin dynamics and the fluctuating
Lattice Boltzmann method, respectively. Our simulations show a dramatic
reduction of the crystal growth velocity due to HIs even at moderate
hydrodynamic coupling. A detailed analysis shows that this slowdown is due to
the wall-like properties of the crystal surface, which reduces the colloidal
diffusion towards the crystal surface by hydrodynamic screening.
Crystallization in suspensions therefore differs strongly from pure melts,
making them less useful as a toy model than previously thought.


title: Abstract machines for game semantics, revisited

abstract:
  We define new abstract machines for game semantics which correspond to
networks of conventional computers, and can be used as an intermediate
representation for compilation targeting distributed systems. This is achieved
in two steps. First we introduce the HRAM, a Heap and Register Abstract
Machine, an abstraction of a conventional computer, which can be structured
into HRAM nets, an abstract point-to-point network model. HRAMs are
multi-threaded and subsume communication by tokens (cf. IAM) or jumps. Game
Abstract Machines (GAM), are HRAMs with additional structure at the interface
level, but no special operational capabilities. We show that GAMs cannot be
naively composed, but composition must be mediated using appropriate HRAM
combinators. HRAMs are flexible enough to allow the representation of game
models for languages with state (non-innocent games) or concurrency
(non-alternating games). We illustrate the potential of this technique by
implementing a toy distributed compiler for ICA, a higher-order programming
language with shared state concurrency, thus significantly extending our
previous distributed PCF compiler. We show that compilation is sound and
memory-safe, i.e. no (distributed or local) garbage collection is necessary.


title:
Universal Renyi mutual information in classical systems: the case of
  kagome ice

abstract:
  We study the Renyi mutual information of classical systems characterized by a
transfer matrix. We first establish a general relationship between the Renyi
mutual information of such classical mixtures of configuration states, and the
Renyi entropy of a corresponding Rokhsar-Kivelson--type quantum superposition.
We then focus on chiral and nonchiral kagome-ice systems, classical spin
liquids on the kagome lattice, which respectively have critical and short-range
correlations. Through a mapping of the chiral kagome ice to the quantum
Liftshitz critical field theory, we predict a universal subleading term in the
Renyi mutual information of this classical spin liquid, which can be realized
in the pyrochlore spin ice in a magnetic field. We verify our prediction with
direct numerical transfer-matrix computations, and further demonstrate that the
nonchiral kagome ice (and the corresponding quantum Rokhsar-Kivelson
superposition) is a topologically trivial phase. Finally, we argue that the
universal term in the mutual information of the chiral kagome ice is fragile
against the presence of defects.


title: Compressed Sensing Matrices: Binary vs. Ternary

abstract:
  Binary matrix and ternary matrix are two types of popular sensing matrices in
compressed sensing for their competitive performance and low computation.
However, to the best of our knowledge, there seems no literature aiming at
evaluating their performances if they hold the same sparisty, though it is of
practical importance. Based on both RIP analysis and numerical simulations,
this paper, for the first time, discloses that {0, 1} binary matrix holds
better overall performance over {0, +1, -1} ternary matrix, if they share the
same distribution on nonzero positions.


title: Greedy Approach for Low-Rank Matrix Recovery

abstract:
  We describe the Simple Greedy Matrix Completion Algorithm providing an
efficient method for restoration of low-rank matrices from incomplete corrupted
entries.
  We provide numerical evidences that, even in the simplest implementation, the
greedy approach may increase the recovery capability of existing algorithms
significantly.


title:
Soft X-ray Fluxes of Major Flares Far Behind the Limb as Estimated Using
  STEREO EUV Images

abstract:
  With increasing solar activity since 2010, many flares from the backside of
the Sun have been observed by the Extreme Ultraviolet Imager (EUVI) on either
of the twin STEREO spacecraft. Our objective is to estimate their X-ray peak
fluxes from EUVI data by finding a relation of the EUVI with GOES X-ray fluxes.
Because of the presence of the Fe xxiv line at 192 A, the response of the EUVI
195 A channel has a secondary broad peak around 15 MK, and its fluxes closely
trace X-ray fluxes during the rise phase of flares. If the flare plasma is
isothermal, the EUVI flux should be directly proportional to the GOES flux. In
reality, the multithermal nature of the flare and other factors complicate the
estimation of the X-ray fluxes from EUVI observations. We discuss the uncer-
tainties, by comparing GOES fluxes with the high cadence EUV data from the
Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory
(SDO). We conclude that the EUVI 195 A data can provide estimates of the X-ray
peak fluxes of intense flares (e.g., above M4 in the GOES scale) with
uncertainties of a factor of a few. Lastly we show examples of intense flares
from regions far behind the limb, some of which show eruptive signatures in AIA
images.


title: Axiomatizing first-order consequences in independence logic

abstract:
  Independence logic cannot be effectively axiomatized. However, first-order
consequences of independence logic sentences can be axiomatized. In this
article we give an explicit axiomatization and prove that it is complete in
this sense. The proof is a generalization of the similar result for dependence
logic.


title:
Bounds of cavitation inception in a creeping flow between eccentric
  cylinders rotating with a small minimum gap

abstract:
  Bounds of cavitation inception are experimentally determined in a creeping
flow between eccentric cylinders, the inner one being static and the outer
rotating at a constant angular velocity, {\Omega}. The geometric configuration
is additionally specified by a small minimum gap between cylinders, H, as
compared with the radii of the inner and outer cylinders. For some values H and
{\Omega}, cavitation bubbles are observed, which are collected on the surface
of the inner cylinder and equally distributed over the line parallel to its
axis near the downstream minimum gap position. Cavitation occurs for the
parameters {H,{\Omega}} within a region bounded on the right by the cavitation
inception curve that passes through the plane origin and cannot exceed the
asymptotic threshold value of the minimum gap, Ha, in whose vicinity cavitation
may occur at H<Ha only for high angular rotation velocities.


title: Boson Stars in AdS

abstract:
  We construct boson stars in global Anti de Sitter (AdS) space and study their
stability. Linear perturbation results suggest that the ground state along with
the first three excited state boson stars are stable. We evolve some of these
solutions and study their nonlinear stability in light of recent work
\cite{Bizon:2011gg} arguing that a weakly turbulent instability drives scalar
perturbations of AdS to black hole formation. However evolutions suggest that
boson stars are nonlinearly stable and immune to the instability for
sufficiently small perturbation. Furthermore, these studies find other families
of initial data which similarly avoid the instability for sufficiently weak
parameters. Heuristically, we argue that initial data families with widely
distributed mass-energy distort the spacetime sufficiently to oppose the
coherent amplification favored by the instability. From the dual CFT
perspective our findings suggest that there exist families of rather generic
initial conditions in strongly coupled CFT (with large number of degrees of
freedom) that do not thermalize in the infinite future.


title: Intrinsic periodicity: the forgotten lesson of quantum mechanics

abstract:
  Wave-particle duality, together with the concept of elementary particles, was
introduced by de Broglie in terms of intrinsically "periodic phenomena".
However, after nearly 90 years, the physical origin of such undulatory
mechanics remains unrevealed. We propose a natural realization of the de
Broglie "periodic phenomenon" in terms of harmonic vibrational modes associated
to space-time periodicities. In this way we find that, similarly to a vibrating
string or a particle in a box, the intrinsic recurrence imposed as a constraint
to elementary particles represents a fully consistent quantization condition.
The resulting classical cyclic dynamics formally match ordinary relativistic
Quantum Mechanics in both the canonical and Feynman formulations. Interactions
are introduced in a geometrodynamical way, similarly to general relativity, by
simply considering that variations of kinematical state can be equivalently
described in terms of modulations of space-time recurrences, as known from
undulatory mechanics. We present this novel quantization prescription from a
historical prospective.


title: Probing Curvature Effects in the Fermi GRB 110920

abstract:
  Curvature effects in Gamma-ray bursts (GRBs) have long been a source of
considerable interest. In a collimated relativistic GRB jet, photons that are
off-axis relative to the observer arrive at later times than on-axis photons
and are also expected to be spectrally softer. In this work, we invoke a
relatively simple kinematic two-shell collision model for a uniform jet profile
and compare its predictions to GRB prompt-emission data for observations that
have been attributed to curvature effects such as the peak-flux--peak-frequency
relation, i.e., the relation between the $\nu$F$_\nu$ flux and the spectral
peak, E$_{pk}$ in the decay phase of a GRB pulse, and spectral lags. In
addition, we explore the behavior of pulse widths with energy. We present the
case of the single-pulse Fermi GRB 110920, as a test for the predictions of the
model against observations.


title:
Law of Large Numbers for Semi-Markov inhomogeneous Random Evolutions on
  Banach spaces

abstract:
  Using backward propagators, we construct inhomogeneous Random Evolutions on
Banach spaces driven by (uniformly ergodic) Semi-Markov processes. After
studying some of their properties (measurability, continuity, integral
representation), we establish a Law of Large Numbers for such inhomogeneous
Random Evolutions, and more precisely their weak convergence - in the Skorohod
space $D$ - to an inhomogeneous semigroup. A martingale characterization of
these inhomogeneous Random Evolutions is also obtained. Finally, we present
applications to inhomogeneous L\'{e}vy Random Evolutions.


title: Vibrational resonance in groundwater-dependent plant ecosystems

abstract:
  We report the phenomenon of vibrational resonance in a single species and a
two species models of groundwater-dependent plant ecosystems with a biharmonic
oscillation (with two widely different frequencies \omega and \Omega, \Omega >>
\omega) of the water table depth. In these two systems, the response amplitude
of the species biomass shows multiple resonances with different mechanisms. The
resonance occurs at both low- and high-frequencies of the biharmonic force. In
the single species bistable system, the resonance occurs at discrete values of
the amplitude g of the high-frequency component of the water table.
Furthermore, the best synchronization of biomass and its carrying capacity with
the biharmonic force occurs at the resonance. In the two species excitable and
time-delay model, the response amplitude (Q) profile shows several plateau
regions of resonance, where the period of evolution of the species biomass
remains the same and the value of Q is inversely proportional to it. The
response amplitude is highly sensitive to the time-delay parameter \tau and
shows two distinct sequences of resonance intervals with a decreasing amplitude
with \tau.


title:
High-Cadence and High-Resolution Halpha Imaging Spectroscopy of a
  Circular Flare's Remote Ribbon with IBIS

abstract:
  We present an unprecedented high-resolution \ha\ imaging spectroscopic
observation of a C4.1 flare taken with IBIS on 2011 October 22. The flare
consists of a main circular ribbon that occurred in a parasitic magnetic
configuration and a remote ribbon that was observed by the IBIS. Such a
circular-ribbon flare with a remote brightening is predicted in 3D fan-spine
reconnection but so far has been rarely observed. During the flare impulsive
phase, we define "core" and "halo" structures in the observed ribbon. Examining
the \ha\ emission spectra averaged in the flare core and halo areas, we find
that only those from the flare cores show typical nonthermal electron beam
heating characteristics. These characteristics include: broad and centrally
reversed emission spectra, excess emission in the red wing with regard to the
blue wing (i.e., red asymmetry), and redshifted bisectors of the emission
spectra. We also observe rather quick timescales for the heating (30 s) and
cooling (14--33 s) in the flare core locations. Therefore, we suggest that the
flare cores revealed by IBIS track the sites of electron beam precipitation
with exceptional spatial and temporal resolution. The flare cores show
two-stage motion (a parallel motion along the ribbon followed by an expansion
motion perpendicular to the ribbon) during the two impulsive phases of the
flare. Some cores jump quickly (30 \kms) between discrete magnetic elements
implying reconnection involving different flux tubes. We observe a very high
temporal correlation ($\gtrsim0.9$) between the integrated \ha\ and HXR
emission during the flare impulsive phase. A short time delay (4.6 s) is also
found in the \ha\ emission spikes relative to HXR bursts. The ionization
timescale of the cool chromosphere and the extra time taken for the electrons
to travel to the remote ribbon site may contribute to this delay.


title: Quasar lensing

abstract:
  I review the observations of gravitationally lensed quasars. These systems
are important because they allow us to probe the properties of the lensing
galaxies at various scales, and they also allow insights into the structures of
the quasars themselves. Samples of quasar lenses also have the potential to act
as cosmographic probes. These areas are described, together with observational
and scientific prospects for the future.


title: On isolated log canonical centers

abstract:
  In this paper, we show that the depth of an isolated log canonical center is
determined by the cohomology of the -1 discrepancy diviors over it. A similar
result also holds for normal isolated Du Bois singularities.


title:
Growth, characterization, and magnetic properties of a Li(Mn,Ni)PO4
  single crystal

abstract:
  Ni-doped LiMn0.95Ni0.05PO4 single crystals have been grown for the first time
by the travelling-solvent floating-zone method at low Argon pressure. The grown
sample exhibits large single crystalline grains as revealed by means of
polarization microscopy and X-ray Laue back scattering. The composition of the
crystal was determined by Energy-dispersive X-ray spectroscopy.
LiMn0.95Ni0.05PO4 orders in an orthorhombic olivine-like structure as expected
and phase purity was confirmed by powder X-ray diffraction. An oriented cuboid
with size of 2.4 x 2.5 x 2.7 mm3 along a, b, and c crystalline directions,
respectively, was used for anisotropic magnetic measurements.


title: Abnormal lithium abundance in several Ap-Bp stars

abstract:
  Using observations of rapidly rotating roAp star HD 12098, obtained with 6m
telescope of SAO RAS in 2005-2008 in nine rotational phases (0.001-0.817), and
code V. Tsymbal ROTATE we identified 3 lithium spots on the surface of star,
one of them coincided with the position of one magnetic pole and two others are
located near the other pole, symmetrically with respect to it. Perhaps magnetic
field of the star has a more complex structure than the dipole (Shavrina 2008).
Lithium abundance in the spots is greater than cosmic one. It can be explained
by diffusion of lithium in the presence of a magnetic field or by production of
lithium in the reactions of "spallation" on the surface of star near the
magnetic poles (see, for example, Goriely 2007). Enhanced lithium abundances
was also determined for other two slowly rotating Ap stars HR 465 and HD 965.
The analysis is performed using a synthetic spectrum method taking into account
magnetic splitting of lines by the SYNTHM code of Khan (2004).


title:
Indication for an intermediate-mass black hole in the globular cluster
  NGC 5286 from kinematics

abstract:
  Intermediate-mass black holes (IMBHs, 10^2-10^5 M_sun) fill the gap between
stellar-mass black holes and supermassive black holes (SMBHs). Simulations have
shown that IMBHs may form in dense star clusters, and therefore may still be
present in these smaller stellar systems. We investigate the Galactic globular
cluster NGC 5286 for indications of a central IMBH using spectroscopic data
from VLT/FLAMES, velocity measurements from the Rutgers Fabry Perot at CTIO,
and photometric data from HST. We run analytic spherical and axisymmetric Jeans
models with different central black-hole masses, anisotropy, mass-to-light
ratio, and inclination. Further, we compare the data to a grid of N-body
simulations without tidal field. Additionally, we use one N-body simulation to
check the results of the spherical Jeans models for the total cluster mass.
Both the Jeans models and the N-body simulations favor the presence of a
central black hole in NGC 5286 and our detection is at the 1- to 1.5-sigma
level. From the spherical Jeans models we obtain a best fit with black-hole
mass M_BH=(1.5+-1.0)x10^3 M_sun. The error is the 68% confidence limit from
Monte Carlo simulations. Axisymmetric models give a consistent result. The best
fitting N-body model is found with a black hole of 0.9% of the total cluster
mass (4.38+-0.18)x10^5 M_sun, which results in an IMBH mass of
M_BH=(3.9+-2.0)x10^3 M_sun. Jeans models give lower values for the total
cluster mass. Our test of the Jeans models with N-body simulation data shows
that this discrepancy has two reasons: The influence of a radially varying M/L
profile, and underestimation of the velocity dispersion as the measurements are
limited to bright stars. We conclude that detection of IMBHs in Galactic
globular clusters remains a challenging task unless their mass fractions are
above those found for SMBHs in nearby galaxies. [abridged]


title: Shift-invariance for FK-DLR states of a 2D quantum bose-gas

abstract:
  This paper continues the work Y. Suhov, M. Kelbert. FK-DLR states of a
quantum bose-gas, arXiv:1304.0782 [math-ph], and focuses on infinite-volume
bosonic states for a quantum system (a quantum gas) in a plane. We work under
similar assumptions upon the form of local Hamiltonians and the type of the
(pair) interaction potential as in the reference above. The result of the paper
is that any infinite-volume FK-DLR functional corresponding to the Hamiltonians
is shift-invariant, regardless of whether this functional is unique or not.


title:
Unique Continuation for Quasimodes on Surfaces of Revolution:
  Rotationally invariant Neighbourhoods

abstract:
  We prove a strong conditional unique continuation estimate for irreducible
quasimodes in rotationally invariant neighbourhoods on compact surfaces of
revolution. The estimate states that Laplace quasimodes which cannot be
decomposed as a sum of other quasimodes have $L^2$ mass bounded below by
$C_\epsilon \lambda^{-1 - \epsilon}$ for any $\epsilon>0$ on any open
rotationally invariant neighbourhood which meets the semiclassical wavefront
set of the quasimode. For an analytic manifold, we conclude the same estimate
with a lower bound of $C_\delta \lambda^{-1 + \delta}$ for some fixed
$\delta>0$.


title:
On hypersurfaces of positive reach, alternating Steiner formulae and
  Hadwiger's Problem

abstract:
  We give new characterisations of sets of positive reach and show that a
closed hypersurface has positive reach if and only if it is of class $C^{1,1}$.
These results are then used to prove new alternating Steiner formul{\ae} for
hypersurfaces of positive reach. Furthermore, it will turn out that every
hypersurface that satisfies an alternating Steiner formula has positive reach.
Finally, we provide a new solution to a problem by Hadwiger on convex sets and
prove long time existence for the gradient flow of mean breadth.


title:
The lumpability property for a family of Markov chains on poset block
  structures

abstract:
  We construct different classes of lumpings for a family of Markov chain
products which reflect the structure of a given finite poset. We use
essentially combinatorial methods. We prove that, for such a product, every
lumping can be obtained from the action of a suitable subgroup of the
generalized wreath product of symmetric groups, acting on the underlying poset
block structure, if and only if the poset defining the Markov process is
totally ordered, and one takes the uniform Markov operator in each factor state
space. Finally we show that, when the state space is a homogeneous space
associated with a Gelfand pair, the spectral analysis of the corresponding
lumped Markov chain is completely determined by the decomposition of the group
action into irreducible submodules.


title:
Rate-Distortion-Based Physical Layer Secrecy with Applications to
  Multimode Fiber

abstract:
  Optical networks are vulnerable to physical layer attacks; wiretappers can
improperly receive messages intended for legitimate recipients. Our work
considers an aspect of this security problem within the domain of multimode
fiber (MMF) transmission. MMF transmission can be modeled via a broadcast
channel in which both the legitimate receiver's and wiretapper's channels are
multiple-input-multiple-output complex Gaussian channels. Source-channel coding
analyses based on the use of distortion as the metric for secrecy are
developed. Alice has a source sequence to be encoded and transmitted over this
broadcast channel so that the legitimate user Bob can reliably decode while
forcing the distortion of wiretapper, or eavesdropper, Eve's estimate as high
as possible. Tradeoffs between transmission rate and distortion under two
extreme scenarios are examined: the best case where Eve has only her channel
output and the worst case where she also knows the past realization of the
source. It is shown that under the best case, an operationally separate
source-channel coding scheme guarantees maximum distortion at the same rate as
needed for reliable transmission. Theoretical bounds are given, and
particularized for MMF. Numerical results showing the rate distortion tradeoff
are presented and compared with corresponding results for the perfect secrecy
case.


title:
Proceedings of the First Conference on Uncertainty in Artificial
  Intelligence (1985)

abstract:
  This is the Proceedings of the First Conference on Uncertainty in Artificial
Intelligence, which was held in Los Angeles, CA, July 10-12, 1985


title: On the colour of thermal noise in fluids

abstract:
  In the paper by Franosch et al., Nature 478, 85 (2011), the positional
fluctuations of Brownian microspheres in fluids were studied by confining the
particles in an optical trap. Experimental access to short timescales has
revealed a resonance peak in the spectrum of these fluctuations, in contrast to
the commonly assumed overdamped motion. This work is also interesting as the
first measurement of the "colour" of thermal noise driving the Brownian
particles through collisions with the fluid molecules. The obtained results are
described by the hydrodynamic theory of the Brownian motion in harmonic
potentials. In the present work we show that the correlation properties of the
thermal noise significantly differ from those determined in the discussed work.


title:
Bidirectional Growth based Mining and Cyclic Behaviour Analysis of Web
  Sequential Patterns

abstract:
  Web sequential patterns are important for analyzing and understanding users
behaviour to improve the quality of service offered by the World Wide Web. Web
Prefetching is one such technique that utilizes prefetching rules derived
through Cyclic Model Analysis of the mined Web sequential patterns. The more
accurate the prediction and more satisfying the results of prefetching if we
use a highly efficient and scalable mining technique such as the Bidirectional
Growth based Directed Acyclic Graph. In this paper, we propose a novel
algorithm called Bidirectional Growth based mining Cyclic behavior Analysis of
web sequential Patterns (BGCAP) that effectively combines these strategies to
generate prefetching rules in the form of 2-sequence patterns with Periodicity
and threshold of Cyclic Behaviour that can be utilized to effectively prefetch
Web pages, thus reducing the users perceived latency. As BGCAP is based on
Bidirectional pattern growth, it performs only (log n+1) levels of recursion
for mining n Web sequential patterns. Our experimental results show that
prefetching rules generated using BGCAP is 5-10 percent faster for different
data sizes and 10-15% faster for a fixed data size than TD-Mine. In addition,
BGCAP generates about 5-15 percent more prefetching rules than TD-Mine.


title: Energy Density Bounds in Cubic Quasi-Topological Cosmology

abstract:
  We investigate the thermodynamical and causal consistency of cosmological
models of the cubic Quasi-Topological Gravity (QTG) in four dimensions, as well
as their phenomenological consequences. Specific restrictions on the maximal
values of the matter densities are derived by requiring the apparent horizon's
entropy to be a non-negative, non-decreasing function of time. The QTG
counterpart of the Einstein-Hilbert (EH) gravity model of linear equation of
state is studied in detail. An important feature of this particular QTG
cosmological model is the new early-time acceleration period of the evolution
of the Universe, together with the standard late-time acceleration present in
the original EH model. The QTG correction to the causal diamond's volume is
also calculated.


title: Spreading of wave packets for neutrino oscillations in vacuum

abstract:
  The effects originated in dispersion with time on spreading of wave packets
for the time-integrated two-flavor neutrino oscillation probabilities in vacuum
are studied in the context of a field theory treatment. The neutrino flavor
states are written as superpositions of neutrino mass eigenstates which are
described by localized wave packets. This study is performed for the limit of
nearly degenerate masses and considering an expansion of the energy until third
order in the momentum. We obtain that the time-integrated neutrino oscillation
probabilities are suppressed by a factor $1/L^2$ for the transversal and
longitudinal dispersion regimes, where $L$ is the distance between the neutrino
source and the detector.


title: The Webdamlog System Managing Distributed Knowledge on the Web

abstract:
  We study the use of WebdamLog, a declarative high-level lan- guage in the
style of datalog, to support the distribution of both data and knowledge (i.e.,
programs) over a network of au- tonomous peers. The main novelty of WebdamLog
compared to datalog is its use of delegation, that is, the ability for a peer
to communicate a program to another peer. We present results of a user study,
showing that users can write WebdamLog programs quickly and correctly, and with
a minimal amount of training. We present an implementation of the WebdamLog
inference engine relying on the Bud dat- alog engine. We describe an
experimental evaluation of the WebdamLog engine, demonstrating that WebdamLog
can be im- plemented efficiently. We conclude with a discussion of ongoing and
future work.


title:
Statistical analysis of the figure of merit of a two-level
  thermoelectric system: a random matrix approach

abstract:
  Using the tools of random matrix theory we develop a statistical analysis of
the transport properties of thermoelectric low-dimensional systems made of two
electron reservoirs set at different temperatures and chemical potentials, and
connected through a low-density-of-states two-level quantum dot that acts as a
conducting chaotic cavity. Our exact treatment of the chaotic behavior in such
devices lies on the scattering matrix formalism and yields analytical
expressions for the joint probability distribution functions of the Seebeck
coefficient and the transmission profile, as well as the marginal
distributions, at arbitrary Fermi energy. The scattering matrices belong to
circular ensembles which we sample to numerically compute the transmission
function, the Seebeck coefficient, and their relationship. The exact transport
coefficients probability distributions are found to be highly non-Gaussian for
small numbers of conduction modes, and the analytical and numerical results are
in excellent agreement. The system performance is also studied, and we find
that the optimum performance is obtained for half-transparent quantum dots;
further, this optimum may be enhanced for systems with few conduction modes.


title: Flexible bundles over rigid affine surfaces

abstract:
  We construct a smooth rational affine surface S with finite automorphism
group but with the property that the group of automorphisms of the cylinder
SxA^2 acts infinitely transitively on the complement of a closed subset of
codimension at least two. Such a surface S is in particular rigid but not
stably rigid with respect to the Makar-Limanov invariant.


title: "Information Paradox" and Schwarzschildian geodesics

abstract:
  We show that the "Information Paradox" follows from inappropriate
considerations on the geodesics of a Schwarzschildian manifold created by a
gravitating point-mass. In particular, we demonstrate that the geometric
differential equation which gives the radial coordinate as a function of the
angular coordinate of the geodesics does not represent fully all the
consequences following from the metric tensor. We remark that: i) it does not
yield the conditions characterizing the circular orbits; (this fact has been
ignored in the previous literature); ii) it "neglects" the space region in
which the radial coordinate is minor or equal to twice the mass of the
gravitating point (in suitable units of measure).


title:
Correcting Errors in Linear Measurements and Compressed Sensing of
  Multiple Sources

abstract:
  We present an algorithm for finding sparse solutions of the system of linear
equations $\Phi\mathbf{x}=\mathbf{y}$ with rectangular matrices $\Phi$ of size
$n\times N$, where $n<N$, when measurement vector $\mathbf{y}$ is corrupted by
a sparse vector of errors $\mathbf e$. We call our algorithm the
$\ell^1$-greedy-generous (LGGA) since it combines both greedy and generous
strategies in decoding. Main advantage of LGGA over traditional error
correcting methods consists in its ability to work efficiently directly on
linear data measurements. It uses the natural residual redundancy of the
measurements and does not require any additional redundant channel encoding. We
show how to use this algorithm for encoding-decoding multichannel sources. This
algorithm has a significant advantage over existing straightforward decoders
when the encoded sources have different density/sparsity of the information
content. That nice property can be used for very efficient blockwise encoding
of the sets of data with a non-uniform distribution of the information. The
images are the most typical example of such sources. The important feature of
LGGA is its separation from the encoder. The decoder does not need any
additional side information from the encoder except for linear measurements and
the knowledge that those measurements created as a linear combination of
different sources.


title:
Multi-reference symmetry-projected variational approaches for ground and
  excited states of the one-dimensional Hubbard model

abstract:
  We present a multi-reference configuration mixing scheme for describing
ground and excited states, with well defined spin and space group symmetry
quantum numbers, of the one-dimensional Hubbard model with nearest-neighbor
hopping and periodic boundary conditions. Within this scheme, each state is
expanded in terms of non-orthogonal and variationally determined
symmetry-projected configurations. The results for lattices up to 30 and 50
sites compare well with the exact Lieb-Wu solutions as well as with results
from other state-of-the-art approximations. In addition to spin-spin
correlation functions in real space and magnetic structure factors, we present
results for spectral functions and density of states computed with an ansatz
whose quality can be well-controlled by the number of symmetry-projected
configurations used to approximate the systems with $N_{e}$ and $N_{e} \pm 1$
electrons. The intrinsic symmetry-broken determinants resulting from the
variational calculations have rich structures in terms of defects that can be
regarded as basic units of quantum fluctuations. Given the quality of the
results here reported, as well as the parallelization properties of the
considered scheme, we believe that symmetry-projection techniques, which have
found ample applications in nuclear structure physics, deserve further
attention in the study of low-dimensional correlated many-electron systems.


title: Binary Tetrahedral Flavor Symmetry

abstract:
  A study of the T' Model and its variants utilizing Binary Tetrahedral Flavor
Symmetry. We begin with a description of the historical context and motivations
for this theory, together with some conceptual background for added clarity,
and an account of our theory's inception in previous works. Our model endeavors
to bridge two categories of particles, leptons and quarks, a unification made
possible by the inclusion of additional Higgs particles, shared between the two
fermion sectors and creating a single coherent system. This is achieved through
the use of the Binary Tetrahedral symmetry group and an investigation of the
Tribimaximal symmetry evidenced by neutrinos. Our work details perturbations
and extensions of this T' Model as we apply our framework to neutrino mixing,
quark mixing, unification, and dark matter. Where possible, we evaluate model
predictions against experimental results and find excellent matching with the
atmospheric and reactor neutrino mixing angles, an accurate prediction of the
Cabibbo angle, and a dark matter candidate that remains outside the limits of
current tests. Additionally, we include mention of a number of unanswered
questions and remaining areas of interest for future study. Taken together, we
believe these results speak to the promising potential of finite groups and
flavor symmetries to act as an approximation of nature.


title:
Study of Standard Model Scalar Production in Bosonic Decay Channels in
  CMS

abstract:
  The status of the Standard Model Scalar Boson search in the bosonic decay
channels at the CMS experiment at the LHC is presented. The results are based
on proton-proton collisions data corresponding to integrated luminosities of up
to 5.1 fb-1 at sqrt{s} = 7 TeV and 19.6 fb-1 at sqrt{s} = 8 TeV. The
observation of a new boson at a mass near 126 GeV is confirmed by the analysis
of the new data and first measurements of the boson properties are shown.


title:
Field dependence of the Spin State and Spectroscopic Modes of
  Multiferroic BiFeO$_3$

abstract:
  The spectroscopic modes of multiferroic BiFeO$_3$ provide detailed
information about the very small anisotropy and Dzyaloshinskii-Moriya (DM)
interactions responsible for the long-wavelength, distorted cycloid below $\TN
= 640$ K. A microscopic model that includes two DM interactions and easy-axis
anisotropy predicts both the zero-field spectroscopic modes as well as their
splitting and evolution in a magnetic field applied along a cubic axis. While
only six modes are optically active in zero field, all modes at the cycloidal
wavevector are activated by a magnetic field. The three magnetic domains of the
cycloid are degenerate in zero field but one domain has lower energy than the
other two in nonzero field. Measurements imply that the higher-energy domains
are depopulated above about 6 T and have a maximum critical field of 16 T,
below the critical field of 19 T for the lowest-energy domain. Despite the
excellent agreement with the measured spectroscopic frequencies, some
discrepancies with the measured spectroscopic intensities suggest that other
weak interactions may be missing from the model.


title:
Correcting for Bias of Molecular Confinement Parameters Induced by Small
  Time Series Sample Sizes in Single-Molecule Trajectories Containing
  Measurement Noise

abstract:
  Several single-molecule studies aim to reliably extract parameters
characterizing molecular confinement or transient kinetic trapping from
experimental observations. Pioneering works from single particle tracking in
membrane diffusion studies [Kusumi et al., Biophysical J., 1993] appealed to
Mean Square Displacement tools for extracting diffusivity and other parameters
quantifying the degree of confinement. More recently, the practical utility of
systematically treating multiple noise sources (including noise induced by
random photon counts) through likelihood techniques have been more broadly
realized in the SPT community. However, bias induced by finite time series
sample sizes has not received great attention. Mitigating parameter bias
induced by finite sampling is important to any scientific endeavor aiming for
high accuracy, but correcting for bias is also often an important step in the
construction of optimal parameter estimates. In this article, it is
demonstrated how a popular model of confinement can be corrected for finite
sample bias in situations where the underlying data exhibits Brownian diffusion
and observations are measured with non-negligible experimental noise (e.g.,
noise induced by finite photon counts). The work of Tang and Chen [J.
Econometrics, 2009] is extended to correct for bias in the estimated corral
radius (a parameter commonly used to quantify confinement in SPT studies) in
the presence of measurement noise. It is shown that the approach presented is
capable of reliably extracting the corral radius using only hundreds of
discretely sampled observations in situations where other methods (including
MSD and Bayesian techniques) would encounter serious difficulties. The ability
to accurately statistically characterize transient confinement suggests new
techniques for quantifying confined and/or hop diffusion in complex
environments.


title: Nonlinear interaction effects in a strongly driven optomechanical cavity

abstract:
  We consider how nonlinear interaction effects can manifest themselves and
even be enhanced in a strongly driven optomechanical system. Using a Keldysh
Green's function approach, we calculate modifications to the cavity density of
states due to both linear and nonlinear optomechanical interactions, showing
that strong modifications can arise even for a weak nonlinear interaction. We
show how this quantity can be directly probed in an optomechanically-induced
transparency type experiment. We also show how the enhanced interaction can
lead to nonclassical behaviour, as evidenced by the behaviour of g_2
correlation functions.


title: Quasiconformal Extensions to Space of Weierstrass-Enneper Lifts

abstract:
  We derive a quasiconformal extension to 3-space of the Weierstrass-Enneper
lifts of a class of harmonic mappings defined in the unit disk. The extension
is based on fibrations of space by circles in domain and image that correspond
to each other in a natural way. Convexity plays an essential role in the
analysis. As a corollary we derive a sufficient condition for the underlying
harmonic mapping to be univalent in the disk, with an explicit quasiconformal
extension to the extended plane that generalizes the well known formula by
Ahlfors-Weill.


title: Green Power Control in Cognitive Wireless Networks

abstract:
  A decentralized network of cognitive and non-cognitive transmitters where
each transmitter aims at maximizing his energy-efficiency is considered. The
cognitive transmitters are assumed to be able to sense the transmit power of
their non-cognitive counterparts and the former have a cost for sensing. The
Stackelberg equilibrium analysis of this $2-$level hierarchical game is
conducted, which allows us to better understand the effects of cognition on
energy-efficiency. In particular, it is proven that the network
energy-efficiency is maximized when only a given fraction of terminals are
cognitive. Then, we study a sensing game where all the transmitters are assumed
to take the decision whether to sense (namely to be cognitive) or not. This
game is shown to be a weighted potential game and its set of equilibria is
studied. Playing the sensing game in a first phase (e.g., of a time-slot) and
then playing the power control game is shown to be more efficient individually
for all transmitters than playing a game where a transmitter would jointly
optimize whether to sense and his power level, showing the existence of a kind
of Braess paradox. The derived results are illustrated by numerical results and
provide some insights on how to deploy cognitive radios in heterogeneous
networks in terms of sensing capabilities. Keywords: Power Control, Stackelberg
Equilibrium, Energy-Efficiency.


title: Efficiency and Structure in Multinomial Inverse Regression

abstract:
  This is the rejoinder for discussion of "Multinomial Inverse Regression for
Text Analysis", Journal of the American Statistical Association 108, 2013.


title:
Reward and adversity processing circuits, their competition and
  interactions with dopamine and serotonin signaling

abstract:
  We propose that dACC, AI and caudolateral OFC(clOFC) project to lateral
habenula (LHb) and D2 loop of ventral striatum (VS), forming a functional
adversity processing circuit, directed towards inhibitory avoidance and
self-control. This circuit learns what is bad or harmful to us and predicts
risks, to stop us from going/moving for bad or suboptimal choices that decrease
our well-being and survival chances. Proposed dACC role is to generate a
WARNING signal when things are going (or might end) bad or wrong to prevent
negative consequences: pain, harm, loss or failure. The AI signals about bad
low aversive qualities, which make us sick or cause discomfort. These cortical
inputs activate directly and indirectly (via D2 loop of VS) the LHb, which
inhibits dopamine and serotonin release (and is reciprocally inhibited by VTA,
DRN) to avoid choosing and doing things leading to harm or loss, but also to
make us feel worse, down when overstimulated. We propose that dopamine
attenuates the output of the adversity processing circuit, thus decreasing
inhibitory avoidance and self-control, while serotonin attenuates dACC, AI,
clOFC, D1 loop of VS, LHb, amygdala and pain pathway. Thus, by reciprocal
inhibition, by causing dopamine and serotonin suppression - and by being
suppressed by them, the adversity processing circuit competes with reward
processing circuit for control of choice behaviour and affective states. We
propose stimulating effect of dopamine and calming inhibitory effect of
serotonin on the active avoidance circuit involving amygdala, linked to threat
processing, anger, fear, self-defense and violences. We describe causes and
roles of dopamine and serotonin signaling, and mental dysfunctions. We add new
idea on vACC role in signaling that we are doing well and in inducing
serotonin, when we gain/reach safety, comfort, valuable resources,
social/biological rewards, affection or goals.


title: Effective double-beta-decay operator for 76Ge and 82Se

abstract:
  We use diagrammatic many-body perturbation theory in combination with
low-momentum interactions derived from chiral effective field theory to
construct effective shell-model transition operators for the neutrinoless
double-beta decay of 76Ge and 82Se. We include all unfolded diagrams to first-
and second-order in the interaction and all singly folded diagrams that can be
constructed from them. The resulting effective operator, which accounts for
physics outside the shell-model space, increases the nuclear matrix element by
about 20% in 76Ge and 30% in 82Se.


title:
Non-dipolar magnetic field at the polar cap of neutron stars and the
  physics of pulsar radiation

abstract:
  Despite the fact that pulsars have been observed for almost half a century,
many questions have remained unanswered. We use the analysis of X-ray
observations in order to study the polar cap region of radio pulsars. The size
of the hot spots implies that the magnetic field configuration just above the
stellar surface differs significantly from a purely dipole one. We can estimate
the surface magnetic field as of the order of $10^{14}\,{\rm G}$. On the other
hand, the temperature of the hot spots is about a few million Kelvins. Based on
these two facts the Partially Screened Gap (PSG) model was proposed to describe
the Inner Acceleration Region (IAR). The PSG model assumes that the temperature
of the actual polar cap is equal to the so-called critical value, i.e. the
temperature at which the outflow of thermal ions from the surface screens the
gap completely.
  We have found that, depending on the conditions above the polar cap, the
generation of high energetic photons in IAR can be caused either by Curvature
Radiation (CR) or by Inverse Compton Scattering (ICS). This results in two
different scenarios of breaking the acceleration gap: the so-called PSG-off
mode for CR-dominated gaps and the PSG-on mode ICS-dominated gaps. The
existence of two different mechanisms of gap breakdown naturally explains the
mode-changing and the pulse nulling. Furthermore, the mode changes of the IAR
may explain the anti-correlation of radio and X-ray emission in very recent
observations of PSR B0943+10 (Hermsen et al., 2013).
  Simultaneous analysis of X-ray and radio properties have allowed to develop a
model which explains the drifting subpulse phenomenon. According to this model
the drift takes place when the charge density in IAR differs from the
Goldreich-Julian co-rotational density. The proposed model allows to verify
both the radio drift parameters and X-ray efficiency of the observed pulsars.


title: A Distribution of Large Particles in the Coma of Comet 103P/Hartley 2

abstract:
  The coma of comet 103P/Hartley 2 has a significant population of large
particles observed as point sources in images taken by the Deep Impact
spacecraft. We measure their spatial and flux distributions, and attempt to
constrain their composition. The flux distribution of these particles implies a
very steep size distribution with power-law slopes ranging from -6.6 to -4.7.
The radii of the particles extend up to 20 cm, and perhaps up to 2 m, but their
exact sizes depend on their unknown light scattering properties. We consider
two cases: bright icy material, and dark dusty material. The icy case better
describes the particles if water sublimation from the particles causes a
significant rocket force, which we propose as the best method to account for
the observed spatial distribution. Solar radiation is a plausible alternative,
but only if the particles are very low density aggregates. If we treat the
particles as mini-nuclei, we estimate they account for <16-80% of the comet's
total water production rate (within 20.6 km). Dark dusty particles, however,
are not favored based on mass arguments. The water production rate from bright
icy particles is constrained with an upper limit of 0.1 to 0.5% of the total
water production rate of the comet. If indeed icy with a high albedo, these
particles do not appear to account for the comet's large water production rate.
production rate.
  Erratum: We have corrected the radii and masses of the large particles of
comet 103P/Hartley 2 and present revised conclusions in the attached erratum.


title:
Predicting Reactor Antineutrino Emissions Using New Precision Beta
  Spectroscopy

abstract:
  A conceptual experimental method for providing a new measurement of the
underlying beta decay spectra from fission products is presented. The goal is
to provide additional information related to the prediction of the antineutrino
emission spectra from fission reactors and assist evaluation of the reactor
neutrino anomaly.


title:
Inefficiency of classically simulating linear optical quantum computing
  with Fock-state inputs

abstract:
  Aaronson and Arkhipov recently used computational complexity theory to argue
that classical computers very likely cannot efficiently simulate linear,
multimode, quantum-optical interferometers with arbitrary Fock-state inputs
[Aaronson and Arkhipov, Theory Comput. 9, 143 (2013)]. Here we present an
elementary argument that utilizes only techniques from quantum optics. We
explicitly construct the Hilbert space for such an interferometer and show that
its dimension scales exponentially with all the physical resources. We also
show in a simple example just how the Schr\"odinger and Heisenberg pictures of
quantum theory, while mathematically equivalent, are not in general
computationally equivalent. Finally, we conclude our argument by comparing the
symmetry requirements of multiparticle bosonic to fermionic interferometers
and, using simple physical reasoning, connect the nonsimulatability of the
bosonic device to the complexity of computing the permanent of a large matrix.


title:
The planar directed k-Vertex-Disjoint Paths problem is fixed-parameter
  tractable

abstract:
  Given a graph G and k pairs of vertices (s_1,t_1), ..., (s_k,t_k), the
k-Vertex-Disjoint Paths problem asks for pairwise vertex-disjoint paths P_1,
..., P_k such that P_i goes from s_i to t_i. Schrijver [SICOMP'94] proved that
the k-Vertex-Disjoint Paths problem on planar directed graphs can be solved in
time n^{O(k)}. We give an algorithm with running time 2^{2^{O(k^2)}} n^{O(1)}
for the problem, that is, we show the fixed-parameter tractability of the
problem.


title: On Chip Manipulation of Single Photons from a Diamond Defect

abstract:
  Operating reconfigurable quantum circuits with single photon sources is a key
goal of photonic quantum information science and technology. We use an
integrated waveguide device comprising of directional couplers and a
reconfigurable thermal phase controller to manipulate single photons emitted
from a chromium related colour centre in diamond. Observation of both a
wave-like interference pattern and particle-like sub-Poissionian
autocorrelation functions demonstrates coherent manipulation of single photons
emitted from the chromium related centre and verifies wave particle duality.


title:
Comparison of metrics from retarded integrals and transverse traceless
  subgauge

abstract:
  The time-varying gravitational field produced by a Weber bar is used to
explore mathematical features of the linearized Einstein equation. We present a
self-contained formal framework for the treatment of the linear field, which is
applicable to several situations where the standard quadrupolar formulas are
not adequate. The expressions for retarded integrals reveal a singularity
associated with boundary conditions. Results from the transverse traceless
subgauge are compared with the radiation calculated from retarded integrals.
Lienard-Wiechert potentials are used in a treatment of the Weber bar as a
collection of point particles and further possible applications are outlined.
The Riemann tensor clarifies the transition from near-field geodesic forces to
tidal forces in the far field.


title: Dimension of zero weight space: An algebro-geometric approach

abstract:
  Let G be a connected, adjoint, simple algebraic group over the complex
numbers with a maximal torus T and a Borel subgroup B containing T. The study
of zero weight spaces in irreducible representations of G has been a topic of
considerable interest; there are many works which study the zero weight space
as a representation space for the Weyl group. In this paper, we study the
variation on the dimension of the zero weight space as the irreducible
representation varies over the set of dominant integral weights for T which are
lattice points in a certain polyhedral cone. The theorem proved here asserts
that the zero weight spaces have dimensions which are piecewise polynomial
functions on the polyhedral cone of dominant integral weights.


title: Graphs with two trivial critical ideals

abstract:
  The critical ideals of a graph are the determinantal ideals of the
generalized Laplacian matrix associated to a graph. A basic property of the
critical ideals of graphs asserts that the graphs with at most k trivial
critical ideals, $\Gamma_{\leq k}$, are closed under induced subgraphs. In this
article we find the set of minimal forbidden subgraphs for $\Gamma_{\leq 2}$,
and we use this forbidden subgraphs to get a classification of the graphs in
$\Gamma_{\leq 2}$. As a consequence we give a classification of the simple
graphs whose critical group has two invariant factors equal to one. At the end
of this article we give two infinite families of forbidden subgraphs.


title: Drag force scaling for penetration into granular media

abstract:
  Impact dynamics is measured for spherical and cylindrical projectiles of many
different densities dropped onto a variety non-cohesive granular media. The
results are analyzed in terms of the material-dependent scaling of the inertial
and frictional drag contributions to the total stopping force. The inertial
drag force scales similar to that in fluids, except that it depends on the
internal friction coefficient. The frictional drag force scales as the
square-root of the density of granular medium and projectile, and hence cannot
be explained by the combination of granular hydrostatic pressure and Coulomb
friction law. The combined results provide an explanation for the
previously-observed penetration depth scaling.


title:
Sinc-based method for an efficient solution in the direct space of
  quantum wave equations with periodic boundary conditions

abstract:
  The solution of differential problems, and in particular of quantum wave
equations, can in general be performed both in the direct and in the reciprocal
space. However, to achieve the same accuracy, direct-space finite-difference
approaches usually involve handling larger algebraic problems with respect to
the approaches based on the Fourier transform in reciprocal space. This is the
result of the errors that direct-space discretization formulas introduce into
the treatment of derivatives. Here, we propose an approach, relying on a set of
sinc-based functions, that allows us to achieve an exact representation of the
derivatives in the direct space and that is equivalent to the solution in the
reciprocal space. We apply this method to the numerical solution of the Dirac
equation in an armchair graphene nanoribbon with a potential varying only in
the transverse direction.


title: Neutron Scattering and Its Application to Strongly Correlated Systems

abstract:
  Neutron scattering is a powerful probe of strongly correlated systems. It can
directly detect common phenomena such as magnetic order, and can be used to
determine the coupling between magnetic moments through measurements of the
spin-wave dispersions. In the absence of magnetic order, one can detect diffuse
scattering and dynamic correlations. Neutrons are also sensitive to the
arrangement of atoms in a solid (crystal structure) and lattice dynamics
(phonons). In this chapter, we provide an introduction to neutrons and neutron
sources. The neutron scattering cross section is described and formulas are
given for nuclear diffraction, phonon scattering, magnetic diffraction, and
magnon scattering. As an experimental example, we describe measurements of
antiferromagnetic order, spin dynamics, and their evolution in the
La(2-x)Ba(x)CuO(4) family of high-temperature superconductors.


title:
Volatile Transport inside Super-Earths by Entrapment in the Water Ice
  Matrix

abstract:
  Whether volatiles can be entrapped in a background matrix composing planetary
envelopes and be dragged via convection to the surface is a key question in
understanding atmospheric fluxes, cycles and composition. In this paper we
consider super-Earths with an extensive water mantle (i.e. water planets), and
the possibility of entrapment of methane in their extensive water ice
envelopes. We adopt the theory developed by van der Waals & Platteeuw (1959)
for modelling solid solutions, often used for modelling clathrate hydrates, and
modify it in order to estimate the thermodynamic stability field of a new
phase, called methane filled ice Ih. We find that in comparison to water ice
VII the filled ice Ih structure may be stable not only at the high pressures
but also at the high temperatures expected at the core-water mantle transition
boundary of water planets.


title: A Coarse-Grained Model for Predicting RNA Folding Thermodynamics

abstract:
  We present a thermodynamically robust coarse-grained model to simulate
folding of RNA in monovalent salt solutions. The model includes stacking,
hydrogen bond and electrostatic interactions as fundamental components in
describing the stability of RNA structures. The stacking interactions are
parametrized using a set of nucleotide-specific parameters, which were
calibrated against the thermodynamic measurements for single-base stacks and
base-pair stacks. All hydrogen bonds are assumed to have the same strength,
regardless of their context in the RNA structure. The ionic buffer is modeled
implicitly, using the concept of counterion condensation and the Debye-H\"uckel
theory. The three adjustable parameters in the model were determined by fitting
the experimental data for two RNA hairpins and a pseudoknot. A single set of
parameters provides good agreement with thermodynamic data for the three RNA
molecules over a wide range of temperatures and salt concentrations. In the
process of calibrating the model, we establish the extent of counterion
condensation onto the single-stranded RNA backbone. The reduced backbone charge
is independent of the ionic strength and is 60% of the RNA bare charge at 37
degrees Celsius. Our model can be used to predict the folding thermodynamics
for any RNA molecule in the presence of monovalent ions.


title: Optical sum-frequency generation in whispering gallery mode resonators

abstract:
  We demonstrate sum-frequency generation in a nonlinear whispering gallery
mode resonator between a telecom wavelength and the Rb D2 line, achieved
through natural phase matching. Due to the strong optical field confinement and
ultra high Q of the cavity, we achieve a 1000-fold enhancement in the
conversion efficiency compared to existing waveguide-based devices. The
experimental data are in agreement with the nonlinear dynamics and phase
matching theory in the spherical geometry employed. The experimental and
theoretical results point to a new platform to manipulate the color and quantum
states of light waves toward applications such as atomic memory based quantum
networking and logic operations with optical signals.


title: Multigeometric sequences and Cantorvals

abstract:
  For a sequence $x \in l_1 \setminus c_{00}$, one can consider the achievement
set $E(x)$ of all subsums of series $\sum_{n=1}^{\infty} x(n)$. It is known
that $E(x)$ is one of the following types of sets:
  * finite union of closed intervals,
  * homeomorphic to the Cantor set,
  * homeomorphic to the set $T$ of subsums of $\sum_{n=1}^{\infty} c(n)$ where
$c(2n-1)=\frac{3}{4^n}$ and $c(2n)=\frac{2}{4^n}$ (Cantorval).
  Based on ideas of Jones and Velleman, and Guthrie and Nymann we describe
families of sequences which contain, according to our knowledge, all known
examples of $x$'s with $E(x)$ being Cantorvals.


title: Light Higgs and Vector-like Quarks without Prejudice

abstract:
  Light vector-like quarks with non-renormalizable couplings to the Higgs are a
common feature of models trying to address the electroweak (EW) hierarchy
problem by treating the Higgs as a pseudo-goldstone boson of a global
(approximate) symmetry. We systematically investigate the implications of the
leading dimension five operators on Higgs phenomenology in presence of
dynamical up- and down-type weak singlet as well as weak doublet vector-like
quarks. After taking into account constraints from precision EW and flavour
observables we show that contrary to the renormalizable models, significant
modifications of Higgs properties are still possible and could shed light on
the role of vector-like quarks in solutions to the EW hierarchy problem. We
also briefly discuss implications of higher dimensional operators for direct
vector-like quark searches at the LHC.


title:
Critical Casimir torques and forces acting on needles in two spatial
  dimensions

abstract:
  We investigate the universal orientation-dependent interactions between
non-spherical colloidal particles immersed in a critical solvent by studying
the instructive paradigm of a needle embedded in bounded two-dimensional Ising
models at bulk criticality. For a needle in an Ising strip the interaction on
mesoscopic scales depends on the width of the strip and the length, position,
and orientation of the needle. By lattice Monte Carlo simulations we evaluate
the free energy difference between needle configurations being parallel and
perpendicular to the strip. We concentrate on small but nonetheless mesoscopic
needle lengths for which analytic predictions are available for comparison. All
combinations of boundary conditions for the needles and boundaries are
considered which belong to either the "normal" or the "ordinary" surface
universality class, i.e., which induce local order or disorder, respectively.
We also derive exact results for needles of arbitrary mesoscopic length, in
particular for needles embedded in a half plane and oriented perpendicular to
the corresponding boundary as well as for needles embedded at the center line
of a symmetric strip with parallel orientation.


title:
Electron-vibration energy exchange models in nitrogen-containing plasma
  flows

abstract:
  The physics of vibrational kinetics in nitrogen-containing plasma produced by
collisions with electrons is studied on the basis of recently derived cross
sections and rate coefficients for the resonant vibrational-excitation by
electron-impact. The temporal relaxation of the vibrational energy and of the
vibrational distribution function is analyzed in a state-to-state approach. The
electron and vibrational temperature are varied in the range of [0,50000] K.
Conclusions are drawn with respect to the derivation of reduced models and to
the accuracy of a relaxation time formalism. A analytical fit of the
vibrational relaxation time is given.


title: A Web-based Adaptive and Intelligent Tutor by Expert Systems

abstract:
  Todays, Intelligent and web-based E-learning is one of regarded topics. So
researchers are trying to optimize and expand its application in the field of
education. The aim of this paper is developing of E-learning software which is
customizable, dynamic, intelligent and adaptive with Pedagogy view for learners
in intelligent schools. This system is an integration of adaptive web-based
E-learning with expert systems as well. Learning process in this system is as
follows. First intelligent tutor determines learning style and characteristics
of learner by a questionnaire and then makes his model. After that the expert
system simulator plans a pre-test and then calculates his score. If the learner
gets the required score, the concept will be trained. Finally the learner will
be evaluated by a post-test. The proposed system can improves the education
efficiency highly as well as de-creases the costs and problems of an expert
tutor. As a result, every time and eve-rywhere (ETEW) learning would be
provided via web in this system. Moreover the learners can enjoy a cheap remote
learning even at home in a virtual simulated physical class. So they can learn
thousands courses very simple and fast.


title:
A Web-based Multilingual Intelligent Tutor System based on Jackson's
  Learning Styles Profiler and Expert Systems

abstract:
  Nowadays, Intelligent Tutoring Systems (ITSs) are so regarded in order to
improve education quality via new technologies in this area. One of the
problems is that the language of ITSs is different from the learner's. It
forces the learners to learn the system language. This paper tries to remove
this necessity by using an Automatic Translator Component in system structure
like Google Translate API. This system carry out a pre-test and post-test by
using Expert System and Jackson Model before and after of training a concept.
It constantly updates learner model to save all changes in learning process. So
this paper offers an E-Learning system which is web-based, intelligent,
adaptive, multilingual and remotely accessible where tutors and learners can
have non-identical language. It is also applicable Every Time and Every Where
(ETEW). Furthermore, it trains the concepts in the best method with any
language and low cost.


title:
Delayed feedback control of unstable steady states with high-frequency
  modulation of the delay

abstract:
  We analyze the stabilization of unstable steady states by delayed feedback
control with a periodic time-varying delay in the regime of a high-frequency
modulation of the delay. The average effect of the delayed feedback term in the
control force is equivalent to a distributed delay in the interval of the
modulation, and the obtained distribution depends on the type of the
modulation. In our analysis we use a simple generic normal form of an unstable
focus, and investigate the effects of phase-dependent coupling and the
influence of the control loop latency on the controllability. In addition, we
have explored the influence of the modulation of the delays in multiple delay
feedback schemes consisting of two independent delay lines of Pyragas type. A
main advantage of the variable delay is the considerably larger domain of
stabilization in parameter space.


title:
The group of automorphisms of the Lie algebra of derivations of a field
  of rational functions

abstract:
  We prove that the group of automorphisms of the Lie algebra $\Der_K (Q_n)$ of
derivations of the field of rational functions $Q_n=K(x_1,..., x_n)$ over a
field of characteristic zero is canonically isomorphic to the group of
automorphisms of the $K$-algebra $Q_n$.


title:
Integrated Perturbation Theory and One-loop Power Spectra of Biased
  Tracers

abstract:
  General and explicit predictions from the integrated perturbation theory
(iPT) for power spectra and correlation functions of biased tracers are derived
and presented in the one-loop approximation. The iPT is a general framework of
the nonlinear perturbation theory of cosmological density fields in presence of
nonlocal bias, redshift-space distortions, and primordial non-Gaussianity.
Analytic formulas of auto and cross power spectra of nonlocally biased tracers
in both real and redshift spaces are derived and the results are
comprehensively summarized. The main difference from previous formulas derived
by the present author is to include effects of generally nonlocal Lagrangian
bias and primordial non-Gaussianity, and the derivation method of the new
formula is fundamentally different from the previous one. Relations to recent
work on improved methods of nonlinear perturbation theory in literature are
clarified and discussed.


title: Discovery of Lyman Break Galaxies at z~7 from the ZFOURGE Survey

abstract:
  Star-forming galaxies at redshifts z>6 are likely responsible for the
reionization of the universe, and it is important to study the nature of these
galaxies. We present three candidates for z~7 Lyman-break galaxies (LBGs) from
a 155 arcmin^2 area in the CANDELS/COSMOS field imaged by the deep FourStar
Galaxy Evolution (zFourGE) survey. The FourStar medium-band filters provide the
equivalent of R~10 spectroscopy, which cleanly distinguishes between z~7 LBGs
and brown dwarf stars. The distinction between stars and galaxies based on an
object's angular size can become unreliable even when using HST imaging; there
exists at least one very compact z~7 candidate (FWHM~0.5-1 kpc) that is
indistinguishable from a point source. The medium-band filters provide narrower
redshift distributions compared with broad-band-derived redshifts. The UV
luminosity function derived using the three z~7 candidates is consistent with
previous studies, suggesting an evolution at the bright end (MUV -21.6 mag)
from z~7 to z~5. Fitting the galaxies' spectral energy distributions, we
predict Lyman-alpha equivalent widths for the two brightest LBGs, and find that
the presence of a Lyman-alpha line affects the medium-band flux thereby
changing the constraints on stellar masses and UV spectral slopes. This
illustrates the limitations of deriving LBG properties using only broad-band
photometry. The derived specific star-formation rates for the bright LBGs are
~13 per Gyr, slightly higher than the lower-luminosity LBGs, implying that the
star-formation rate increases with stellar mass for these galaxies.


title:
Nonlinear stochastic biasing of halos: Analysis of cosmological N-body
  simulations and perturbation theories

abstract:
  It is crucial to understand and model a behavior of galaxy biasing for future
ambitious galaxy redshift surveys. Using 40 large cosmological N-body
simulations for a standard LambdaCDM cosmology, we study the cross-correlation
coefficient between matter and the halo density field, which is an indicator of
the stochasticity of bias, over a wide redshift range 0\le z \le 3. The
cross-correlation coefficient is important to extract information on the matter
density field, e.g., by combining galaxy clustering and galaxy-galaxy lensing
measurements. We compare the simulation results with integrated perturbation
theory (iPT) proposed by one of the present authors and standard perturbation
theory (SPT) combined with a phenomenological model of local bias. The
cross-correlation coefficient derived from the iPT agrees with N-body
simulation results down to r~15 (10) h^{-1}Mpc within 0.5 (1.0) % for all
redshifts and halo masses we consider. The SPT with local bias does not explain
complicated behaviors on quasilinear scales at low redshifts, while roughly
reproduces the general behavior of the cross-correlation coefficient on fully
nonlinear scales. The iPT is powerful to predict the cross-correlation
coefficient down to quasilinear regimes with a high precision.


title:
Overcoming real-world obstacles in 21 cm power spectrum estimation: A
  method demonstration and results from early Murchison Widefield Array data

abstract:
  We present techniques for bridging the gap between idealized inverse
covariance weighted quadratic estimation of 21 cm power spectra and the
real-world challenges presented universally by interferometric observation. By
carefully evaluating various estimators and adapting our techniques for large
but incomplete data sets, we develop a robust power spectrum estimation
framework that preserves the so-called "EoR window" and keeps track of
estimator errors and covariances. We apply our method to observations from the
32-tile prototype of the Murchinson Widefield Array to demonstrate the
importance of a judicious analysis technique. Lastly, we apply our method to
investigate the dependence of the clean EoR window on frequency--especially the
frequency dependence of the so-called "wedge" feature--and establish upper
limits on the power spectrum from z = 6.2 to z = 11.7. Our lowest limit is
Delta(k) < 0.3 Kelvin at 95% confidence at a comoving scale k = 0.046 Mpc^-1
and z = 9.5.


title:
Proton Stability, Gauge Coupling Unification and a Light $Z^\prime$ in
  Heterotic-string Models

abstract:
  We explore the phenomenological viability of a light Z' in heterotic-string
models, whose existence has been motivated by proton stability arguments. A
class of quasi-realistic string models that produce such a viable Z' are the
Left-Right Symmetric (LRS) heterotic-string models in the free fermionic
formulation. A key feature of these models is that the matter charges under
U(1)_Z' do not admit an E6 embedding. The light Z' in the LRS heterotic-string
models forbids baryon number violating operators, while allowing lepton number
violating operators, hence suppressing proton decay yet allowing for
sufficiently small neutrino masses via a seesaw mechanism. We show that the
constraints imposed by the gauge coupling data and heterotic-string coupling
unification nullify the viability of a light Z' in these models. We further
argue that agreement with the gauge coupling data necessitates that the U(1)_Z'
charges admit an E6 embedding. We discuss how viable string models with this
property may be constructed.