title:
One-dimensional Dirac operators with zero-range interactions: Spectral,
  scattering, and topological results

abstract:
  The spectral and scattering theory for 1-dimensional Dirac operators with
mass $m$ and with zero-range interactions are fully investigated. Explicit
expressions for the wave operators and for the scattering operator are
provided. These new formulae take place in a representation which links, in a
suitable way, the energies $-\infty$ and $+\infty$, and which emphasizes the
role of $\pm m$. Finally, a topological version of Levinson's theorem is
deduced, with the threshold effects at $\pm m$ automatically taken into
account.


title:
Reduction of critical field for magnetic and orbital-ordering phase
  transition in impurity-substituted Nd$_{0.45}$Sr$_{0.55}$MnO$_3$ crystal

abstract:
  We have investigated the Mn-site substitution effect in
Nd$_{0.45}$Sr$_{0.55}$MnO$_3$ single crystal, which has an $A$-type layered
antiferromagnetic ($A$-AFM) phase with the 3$d_{x^2-y^2}$-type orbital-order.
Substitution of Fe or Ga for Mn-site suppresses both the $A$-AFM order and
competing ferromagnetic (FM) correlation whereas Cr substitution suppresses
only the $A$-AFM order but reactivates the underlying FM correlation via
double-exchange mechanism along the AFM coupled $c$-direction. In
Nd$_{0.45}$Sr$_{0.55}$Mn$_{0.95}$Cr$_{0.05}$O$_3$, the $A$-AFM state with the
orbital-order is changed into the orbital-disordered three-dimensional FM
metallic state by applying magnetic field of $\mu_0 H = 12$ T, which is much
smaller than that of the parent compound Nd$_{0.45}$Sr$_{0.55}$MnO$_3$.


title: Separability of drag and thrust in undulatory animals and machines

abstract:
  For nearly a century, researchers have tried to understand the swimming of
aquatic animals in terms of a balance between the forward thrust from swimming
movements and drag on the body. Prior approaches have failed to provide a
separation of these two forces for undulatory swimmers such as lamprey and
eels, where most parts of the body are simultaneously generating drag and
thrust. We nonetheless show that this separation is possible, and delineate its
fundamental basis in undulatory swimmers. Our approach unifies a vast diversity
of undulatory aquatic animals (anguilliform, sub-carangiform, gymnotiform, bal-
istiform, rajiform) and provides design principles for highly agile bioinspired
underwater vehicles. This approach has practical utility within biology as well
as engineering. It is a predictive tool for use in understanding the role of
the mechanics of movement in the evolutionary emergence of morphological
features relating to locomotion. For example, we demonstrate that the
drag-thrust separation framework helps to predict the observed height of the
ribbon fin of electric knifefish, a diverse group of neotropical fishes which
are an important model system in sensory neurobiology. We also show how
drag-thrust separation leads to models that can predict the swimming velocity
of an organism or a robotic vehicle.


title:
The Tactical Optimal Strategy Game (TOSG) Protocol Cockpit Software
  Control For Massive Ordnance Penetrator Release

abstract:
  The Massive Ordnance Penetrator(MOP) has been developed to destroy deeply
buried nuclear components by controlled release from a B2 or B52 airplane. This
type of release must be cockpit software controlled by the Tactical Optimal
Strategy Game(TOSG) Protocol to optimally determine the war game aspects of the
dueling from other countries' MOP releases, and the depth at which the MOP
explosions can occur for maximal safety and risk concerns. The TOSG Protocol
characteristics of games of strategy, games of optimal strategy and tactical
games are defined initially by the game of strategy as a certain series of
events, each of which must have a finite number of distinct results. The
outcome of a game of strategy, in some cases, depends on chance. All other
events depend on the free decision of the players. A game has a solution if
there exist two strategies, which become optimal strategies when each
mathematically attains the value of the game. The TOSG Protocol war game
tactical problem for a class of games can be mathematically modeled as a combat
between two airplanes, each carrying a MOP as the specification of the accuracy
of the firing machinery and the total amount of ammunition that each plane
carries. This silent duel occurs, because each MOP bomber is unable to
determine the number of times its opponent has missed. The TOSG Protocol
realizes a game theory solution of the tactical optimal strategy game utilizing
the theory of games of timing, games of pursuit, games of time lag, games of
sequence, games of maneuvering, games of search, games of positioning and games
of aiming and evasion.


title: PRESS: A Novel Framework of Trajectory Compression in Road Networks

abstract:
  Location data becomes more and more important. In this paper, we focus on the
trajectory data, and propose a new framework, namely PRESS (Paralleled
Road-Network-Based Trajectory Compression), to effectively compress trajectory
data under road network constraints. Different from existing work, PRESS
proposes a novel representation for trajectories to separate the spatial
representation of a trajectory from the temporal representation, and proposes a
Hybrid Spatial Compression (HSC) algorithm and error Bounded Temporal
Compression (BTC) algorithm to compress the spatial and temporal information of
trajectories respectively. PRESS also supports common spatial-temporal queries
without fully decompressing the data. Through an extensive experimental study
on real trajectory dataset, PRESS significantly outperforms existing approaches
in terms of saving storage cost of trajectory data with bounded errors.


title: Feedback induced phase transitions in active porous media

abstract:
  Flow through passive porous media is typically described in terms of a linear
theory relating current fluxes and driving forces, in the presence of a
prescribed heterogeneous permeability. However, many porous systems such as
glacial drainage networks, erosional river bed networks, vascular networks,
social insect swarms and animal architectures such as termite mounds are
continuously remodeled by the flow and thence modify the flow, i.e. they are
active. Here we consider a minimal model for an active porous medium where flow
and resistance are coupled to each other. Using numerical simulations, we show
that this results in both channelization and wall-building transitions
depending on the form of the feedback. A continuum model allows us to
understand the qualitative features of the resulting phase diagram, and
suggests ways to realize complex architectures using simple rules in engineered
systems.


title:
Measuring Noise Temperatures of Phased-Array Antennas for Astronomy at
  CSIRO

abstract:
  We describe the development of a noise-temperature testing capability for
phased-array antennas operating in receive mode from 0.7 GHz to 1.8 GHz.
Sampled voltages from each array port were recorded digitally as the
zenith-pointing array under test was presented with three scenes: (1) a large
microwave absorber at ambient temperature, (2) the unobstructed radio sky, and
(3) broadband noise transmitted from a reference antenna centred over and
pointed at the array under test. The recorded voltages were processed in
software to calculate the beam equivalent noise temperature for a maximum
signal-to-noise ratio beam steered at the zenith. We introduced the
reference-antenna measurement to make noise measurements with reproducible,
well-defined beams directed at the zenith and thereby at the centre of the
absorber target. We applied a detailed model of cosmic and atmospheric
contributions to the radio sky emission that we used as a noise-temperature
reference. We also present a comprehensive analysis of measurement uncertainty
including random and systematic effects. The key systematic effect was due to
uncertainty in the beamformed antenna pattern and how efficiently it
illuminates the absorber load. We achieved a combined uncertainty as low as 4 K
for a 40 K measurement of beam equivalent noise temperature. The measurement
and analysis techniques described in this paper were pursued to support
noise-performance verification of prototype phased-array feeds for the
Australian Square Kilometre Array Pathfinder telescope.


title: The Interstellar Reddening Law within 3kpc from the Sun

abstract:
  We have investigated the interstellar reddening law of young open clusters
within 3kpc from the Sun using optical, near-IR 2MASS, and Spitzer IRAC data.
The total-to-selective extinction ratio Rv of 162 young open clusters (log
t{age} <= 7.3) listed in the open cluster database WEBDA is determined from the
color excess ratios. The young open clusters in the Sgr-Car arm show a
relatively higher $R_V$, those in the Per arm and in the Cygnus region of the
local arm show a relatively smaller value, and those in the Mon-CMa region of
the local arm show a normal value (Rv ~ 3.1).


title:
Double parton interactions in photon + 3 jet and photon + b/c jet + 2
  jet events in ppbar collisions at sqrt{s}=1.96 TeV

abstract:
  We determine the fraction of events with double parton (DP) scattering in a
single ppbar collision at sqrt{s}=1.96 TeV in samples of photon + 3 jet and
photon + b/c jet + 2 jet events collected with the D0 detector and
corresponding to an integrated luminosity of about 8.7 fb^{-1}. The DP
fractions and effective cross sections (sigma_eff) are measured for both event
samples using the same kinematic selections. The measured DP fractions range
from 0.21 to 0.17, with effective cross sections in the photon + 3 jet and
photon + b/c jet + 2 jet samples of sigma_eff^incl = 12.7 +- 0.2 (stat) +- 1.3
(syst) mb and sigma_eff^HF = 14.6 +- 0.6 (stat) +- 3.2 (syst) mb, respectively.


title: Bursting emission from B0611+22

abstract:
  Over the past decade it has become apparent that a class of `bursting
pulsars' exist with the discovery of PSR J1752+2359 and PSR J1938+2213. In
these pulsars, a sharp increase in the emission is observed that then tends to
systematically drop-off from pulse-to-pulse. In this paper we describe the
discovery of such a relationship in high-sensitivity observations of the young
(characteristic age of 90,000 yrs) 0.33 s pulsar B0611+22 at both 327 MHz and
1400 MHz with the Arecibo radio telescope. While Nowakowski previously showed
that B0611+22 has mode-switching properties, the data presented here show, for
the first time, that this pulsar emits bursts with characteristic time-scales
of several hundred seconds. At 327 MHz, the pulsar shows steady behaviour in
one emission mode which is enhanced by bursting emission slightly offset in
pulse phase from this steady emission. Contrastingly at 1400 MHz, the two modes
appear to behave in a competing operation while still offset in phase. Using a
fluctuation spectrum analysis, we also investigate each mode independently for
sub-pulse drifting. Neither emission mode (i.e. during bursts or persistent
emission) shows the presence of the drifting sub-pulse phenomenon. The bursting
phenomena seen here appears to be a hybrid between bursting seen in other
pulsars and the bistable profile illumination behaviour reported in two other
pulsars by Rankin et al. Further examples of this cross-frequency behaviour are
required, as this phenomenon may be quite common among the pulsar population.


title: Correlation and Network Topologies in Global and Local Stock Indices

abstract:
  This study examined how the correlation and network structure of 30 global
indices and 145 local Korean indices belonging to the KOSPI 200 have changed
during the 13-year period, 2000-2012. The correlations among the indices were
calculated. The results showed that although the average correlations of the
global indices increased with time, the local indices showed a decreasing trend
except for drastic changes during crises. The average correlation of the local
indices exceeded the global indices during the crises from 2000-2002, implying
a strong correlation structure among the local indices during this period due
to the detrimental effect of the dot-com bubble. The threshold networks (TN)
were constructed in the observation time window by assigning a threshold value
and determining the network topologies. A significant change in the network
topologies was observed due to the financial crises in both markets. The
Jaccard similarities were also determined using the common links of TNs. The
TNs of the financial network were not consistent with the evolution of the
time, and the successive TNs of the global indices were more similar than those
of the successive local indices. Finally, the Jaccard similarities identified
the change in the market state due to a crisis in both markets.


title: On the Maximum Parsimony distance between phylogenetic trees

abstract:
  Within the field of phylogenetics there is great interest in distance
measures to quantify the dissimilarity of two trees. Here, based on an idea of
Bruen and Bryant, we propose and analyze a new distance measure: the Maximum
Parsimony (MP) distance. This is based on the difference of the parsimony
scores of a single character on both trees under consideration, and the goal is
to find the character which maximizes this difference. In this article we show
that this new distance is a metric and provides a lower bound to the well-known
Subtree Prune and Regraft (SPR) distance. We also show that to compute the MP
distance it is sufficient to consider only characters that are convex on one of
the trees, and prove several additional structural properties of the distance.
On the complexity side, we prove that calculating the MP distance is in general
NP-hard, and identify an interesting island of tractability in which the
distance can be calculated in polynomial time.


title: Option Pricing for Symmetric L\'evy Returns with Applications

abstract:
  This paper considers options pricing when the assumption of normality is
replaced with that of the symmetry of the underlying distribution. Such a
market affords many equivalent martingale measures (EMM). However we argue (as
in the discrete-time setting of Klebaner and Landsman, 2007) that an EMM that
keeps distributions within the same family is a "natural" choice. We obtain
Black-Scholes type option pricing formulae for symmetric Variance-Gamma and
symmetric Normal Inverse Gaussian models.


abstract:
  An experimental model of reflection and transmission of ocean waves by an ice
floe is presented. Evolution of mechanically-generated, regular waves is
monitored in front and in the lee of a solitary, square floe, made of a
synthetic material. Results confirm dependence of reflection and transmission
on the period of the incident wave. Results also indicate that wave overwash on
the floe affects reflection and transmission.


title: Nonlocal energy density functionals for low-energy nuclear structure

abstract:
  We introduce a finite-range pseudopotential built as an expansion in
derivatives up to next-to-next-to-next-to-leading order (N$^3$LO) and we
calculate the corresponding nonlocal energy density functional (EDF). The
coupling constants of the nonlocal EDF, for both finite nuclei and infinite
nuclear matter, are expressed through the parameters of the pseudopotential.
All central, spin-orbit, and tensor terms of the pseudopotential are derived
both in the spherical-tensor and Cartesian representation. At next-to-leading
order (NLO), we also derive relations between the nonlocal EDF expressed in the
spherical-tensor and Cartesian formalism. Finally, a simplified version of the
finite-range pseudopotential is considered, which generates the EDF identical
to that generated by a local potential.


title:
The Performance of Successive Interference Cancellation in Random
  Wireless Networks

abstract:
  This paper provides a unified framework to study the performance of
successive interference cancellation (SIC) in wireless networks with arbitrary
fading distribution and power-law path loss. An analytical characterization of
the performance of SIC is given as a function of different system parameters.
The results suggest that the marginal benefit of enabling the receiver to
successively decode k users diminishes very fast with k, especially in networks
of high dimensions and small path loss exponent. On the other hand, SIC is
highly beneficial when the users are clustered around the receiver and/or very
low-rate codes are used. Also, with multiple packet reception, a lower per-user
information rate always results in higher aggregate throughput in
interference-limited networks. In contrast, there exists a positive optimal
per-user rate that maximizes the aggregate throughput in noisy networks.
  The analytical results serve as useful tools to understand the potential gain
of SIC in heterogeneous cellular networks (HCNs). Using these tools, this paper
quantifies the gain of SIC on the coverage probability in HCNs with
non-accessible base stations. An interesting observation is that, for
contemporary narrow-band systems (e.g., LTE and WiFi), most of the gain of SIC
is achieved by canceling a single interferer.


title:
Beam energy dependence of moments of the net-charge multiplicity
  distributions in Au+Au collisions at RHIC

abstract:
  We report the first measurements of the moments -- mean ($M$), variance
($\sigma^{2}$), skewness ($S$) and kurtosis ($\kappa$) -- of the net-charge
multiplicity distributions at mid-rapidity in Au+Au collisions at seven
energies, ranging from $\sqrt {{s_{\rm NN}}}$= 7.7 to 200 GeV, as a part of the
Beam Energy Scan program at RHIC. The moments are related to the thermodynamic
susceptibilities of net-charge, and are sensitive to the proximity of the QCD
critical point. We compare the products of the moments, $\sigma^{2}/M$,
$S\sigma$ and $\kappa\sigma^{2}$ with the expectations from Poisson and
negative binomial distributions (NBD). The $S\sigma$ values deviate from
Poisson and are close to NBD baseline, while the $\kappa\sigma^{2}$ values tend
to lie between the two. Within the present uncertainties, our data do not show
non-monotonic behavior as a function of collision energy. These measurements
provide a distinct way of determining the freeze-out parameters in heavy-ion
collisions by comparing with theoretical models.


title:
Distributed Control Subject to Delays Satisfying an $\mathcal{H}_\infty$
  Norm Bound

abstract:
  This paper presents a characterization of distributed controllers subject to
delay constraints induced by a strongly connected communication graph that
achieve a prescribed closed loop $\mathcal{H}_\infty$ norm. Inspired by the
solution to the $\mathcal{H}_2$ problem subject to delays, we exploit the fact
that the communication graph is strongly connected to decompose the controller
into a local finite impulse response component and a global but delayed
infinite impulse response component. This allows us to reduce the control
synthesis problem to a linear matrix inequality feasibility test.


title:
A temperature dependent formation time approach for \Upsilon suppression
  at LHC

abstract:
  We present here a model to describe the bottomonium suppression in Pb$+$Pb
collisions at Large Hadron Collider (LHC), at $\sqrt{s_{NN}}=2.76$ TeV by using
the quasi-particle model (QPM) equation of state (EOS) for the Quark-Gluon
Plasma (QGP) expanding under Bjorken's hydrodynamical expansion. The current
model includes the modification of the formation time based on the temperature
of QGP, color screening during bottomonium production, gluon induced
dissociation and collisional damping. The cold nuclear matter (CNM) effects and
decay of higher resonances of bottomonium have also been included in the
present work. The final suppression of the bottomonium states, at mid rapidity
is calculated as a function of centrality. The results compare closely with the
recent data at Large hadron Collider (LHC) in the mid rapidity region for
various centrality bins. {\nd \it Keywords } : Color screening, Gluonic
dissociation, Collisional damping, Survival probability, CNM effects\\ {\nd \it
PACS numbers } : 12.38.Mh, 12.38.Gc, 25.75.Nq, 24.10.Pa


title:
Adaptive, Anisotropic and Hierarchical cones of Discrete Convex
  functions

abstract:
  We address the discretization of optimization problems posed on the cone of
convex functions, motivated in particular by the principal agent problem in
economics, which models the impact of monopoly on product quality. Consider a
two dimensional domain, sampled on a grid of N points. We show that the cone of
restrictions to the grid of convex functions is in general characterized by N^2
linear inequalities; a direct computational use of this description therefore
has a prohibitive complexity. We thus introduce a hierarchy of sub-cones of
discrete convex functions, associated to stencils which can be adaptively,
locally, and anisotropically refined. Numerical experiments optimize the
accuracy/complexity tradeoff through the use of a-posteriori stencil refinement
strategies.


title:
3/4 Fractional superdiffusion of energy in a system of harmonic
  oscillators perturbed by a conservative noise

abstract:
  We consider a harmonic chain perturbed by an energy conserving noise and show
that after a space-time rescaling the energy-energy correlation function is
given by the solution of a skew-fractional heat equation with exponent 3/4.


title:
Towards a Multi-criteria Development Distribution Model: An Analysis of
  Existing Task Distribution Approaches

abstract:
  Distributing development tasks in the context of global software development
bears both many risks and many opportunities. Nowadays, distributed development
is often driven by only a few factors or even just a single factor such as
workforce costs. Risks and other relevant factors such as workforce
capabilities, the innovation potential of different regions, or cultural
factors are often not recognized sufficiently. This could be improved by using
empirically-based multi-criteria distribution models. Currently, there is a
lack of such decision models for distributing software development work. This
article focuses on mechanisms for such decision support. First, requirements
for a distribution model are formulated based on needs identified from
practice. Then, distribution models from different domains are surveyed,
compared, and analyzed in terms of suitability. Finally, research questions and
directions for future work are given.


title:
Framed 4-valent Graph Minor Theory I: Intoduction. A Planarity Criterion
  and Linkless Embeddability

abstract:
  The present paper is the first one in the sequence of papers about a simple
class of {\em framed $4$-graphs}; the goal of the present paper is to collect
some well-known results on planarity and to reformulate them in the language of
{\em minors}.
  The goal of the whole sequence is to prove analogues of the
Robertson-Seymour-Thomas theorems for framed $4$-graphs: namely, we shall prove
that many minor-closed properties are classified by finitely many excluded
graphs.
  From many points of view, framed $4$-graphs are easier to consider than
general graphs; on the other hand, framed $4$-graphs are closely related to
many problems in graph theory.


title: Multiple Ionization of Neon under soft x-rays: Theory vs Experiment

abstract:
  We present a rather elaborate theoretical model describing the dynamics of
Neon under radiation of photon energies $\sim 93$ eV and pulse duration in the
range of 15 fs, within the framework of Lowest non-vanishing Order of
Perturbation Theory (LOPT), cast in terms of rate equations. Our model includes
sequential as well as direct multiple ionization channels from the 2s and 2p
atomic shells, including aspects of fine structure, whereas the stochastic
nature of SASE-FEL light pulses is also taken into account. Our predictions for
the ionization yields of the different ionic species are in excellent agreement
with the related experimental observations at FLASH.


title: Gaussian Analytic functions in the unit ball

abstract:
  We study some properties of hyperbolic Gaussian analytic functions of
intensity $L$ in the unit ball of $\mathbb C^n$. First we deal with the
asymptotics of fluctuations of linear statistics as $L\to\infty$. Then we
estimate the probability of large deviations (with respect to the expected
value) of such linear statistics and use this estimate to prove a hole theorem.


title:
Generation and Transfer of Polarized Radiation in Hydrodynamical Models
  of the Solar Chromosphere

abstract:
  The main goal of this thesis has been to investigate the effects that the
macroscopic vertical velocity fields have on the scattering polarization
signals formed in the solar chromosphere. Until now, the impact of macroscopic
motions had never been considered in the treatment of the polarization signals
produced by scattering processes and the Hanle effect. This is especially
important in the quiet solar chromosphere, given its strong dynamism and
reduced magnetic field intensity. Our investigation focused in the solution of
the multilevel, non-LTE radiative problem of the generation and transfer of
polarized radiation in increasingly realistic atmosphere models
(Milne-Eddington and two-level atom atmospheres, semi-empirical models with
ad-hoc velocities, hydrodynamical time-dependent models and a snapshot of a 3D
MHD simulation) for the Ca II IR triplet lines (at 8498, 8542 and 8662 A). As a
particular result, we obtained the first synthetic tomography of a model quiet
chromosphere that includes maps of linear polarization dominated by the Hanle
effect and of circular polarization dominated by the Zeeman effect. We also
studied the relevance of dynamic and thermodynamic in the inference of the
chromospheric magnetic field orientation taking into account the 90{\deg} and
180{\deg} ambiguities and showing how velocity and temperature gradients can
affect the diagnostic process. We show that Solar-C and the European Solar
Telescope should be able to capture the dynamic effects simulated in this
thesis for the Ca II IR triplet lines. Namely, the vertical velocity gradients
are able to modulate the resulting scattering polarization amplitudes,
specially in the presence of shock waves.


title:
Jet-Triggered Photons from Back-Scattering Kinematics for Quark Gluon
  Plasma Tomography

abstract:
  High energy photons created from back-scattering of jets in quark gluon
plasma are a valuable probe of the temperature of the plasma, and of the energy
loss mechanism of quarks in the plasma. An unambiguous identification of these
photons through single inclusive photon measurements and photon azimuthal
anisotropies has so far been elusive. We estimate the spectra of
back-scattering photons in coincidence with trigger jets for typical kinematic
situations at the Large Hadron Collider and the BNL Relativistic Heavy Ion
Collider. We find that the separation of back-scattering photons from other
photon sources using trigger jets depends crucially on our ability to reliably
estimate the initial trigger jet energy. We estimate that jet reconstruction
techniques in heavy ion experiments need to be able to get to jet
$R_{AA}\gtrsim 0.7$ in central collisions for viable back-scattering signals.


title: On Certain Wronskians of Multiple Orthogonal Polynomials

abstract:
  We consider determinants of Wronskian type whose entries are multiple
orthogonal polynomials associated with a path connecting two multi-indices. By
assuming that the weight functions form an algebraic Chebyshev (AT) system, we
show that the polynomials represented by the Wronskians keep a constant sign in
some cases, while in some other cases oscillatory behavior appears, which
generalizes classical results for orthogonal polynomials due to Karlin and
Szeg\H{o}. There are two applications of our results. The first application
arises from the observation that the $m$-th moment of the average
characteristic polynomials for multiple orthogonal polynomial ensembles can be
expressed as a Wronskian of the type II multiple orthogonal polynomials. Hence,
it is straightforward to obtain the distinct behavior of the moments for odd
and even $m$ in a special multiple orthogonal ensemble - the AT ensemble. As
the second application, we derive some Tur\'an type inequalities for multiple
Hermite and multiple Laguerre polynomials (of two kinds). Finally, we study
numerically the geometric configuration of zeros for the Wronskians of these
multiple orthogonal polynomials. We observe that the zeros have regular
configurations in the complex plane, which might be of independent interest.


title: Arcs intersecting at most once

abstract:
  We prove that on a punctured oriented surface with Euler characteristic chi <
0, the maximal cardinality of a set of essential simple arcs that are pairwise
non-homotopic and intersecting at most once is 2|chi|(|chi|+1). This gives a
cubic estimate in |chi| for a set of curves pairwise intersecting at most once
on a closed surface. We also give polynomial estimates in |chi| for sets of
arcs and curves pairwise intersecting a uniformly bounded number of times.
Finally, we prove that on a punctured sphere the maximal cardinality of a set
of arcs starting and ending at specified punctures and pairwise intersecting at
most once is 1/2|chi|(|chi|+1).


title:
On the complex branch points in $\pi N$ scattering amplitude and the
  multiple poles feature of resonances

abstract:
  A simple heuristic argument to understand the existence of complex branch
points in the $\pi N$ scattering amplitude is presented.
  It is based on a hypothesis that the singularity structure of the $\pi N$
scattering amplitude is a smooth varying function of the pion mass. We then
show that the two-pole structure found to correspond to the Roper resonance
could just a simple direct mathematical consequence of including additional
Riemann surface in the analysis. Our study indicates that it is always possible
to have multiple poles, either two or four etc., in different Riemann sheet, to
be associated with a resonance. The poles in all Riemann sheets should be
looked for to determine whether the two-pole feature of the Roper resonance
$N^*(1440)$ is a manifestation of the "exact degeneracy" discussed here but
masked by numerical indeterminacy, or an "accidental" one. The determination of
the multiplicity of a pole could provide some information of the analytical
structure of the numerator of the pole term, as the numerator of the pole term
is related to resonance form factor.


title:
New Outer Bounds for the Interference Channel with Unilateral Source
  Cooperation

abstract:
  This paper studies the two-user interference channel with unilateral source
cooperation, which consists of two source-destination pairs that share the same
channel and where one full-duplex source can overhear the other source through
a noisy in-band link. Novel outer bounds of the type 2Rp+Rc/Rp+2Rc are
developed for the class of injective semi-deterministic channels with
independent noises at the different source-destination pairs. The bounds are
then specialized to the Gaussian noise case. Interesting insights are provided
about when these types of bounds are active, or in other words, when unilateral
cooperation is too weak and leaves "holes" in the system resources.


title: New Identities for small hyperbolic surfaces

abstract:
  Luo and Tan gave a new identity for hyperbolic surfaces with/without geodesic
boundary in terms of dilogarithms of the lengths of simple closed geodesics on
embedded three-holed spheres or one-holed tori. However, the identity was
trivial for a hyperbolic one-holed torus with geodesic boundary. In this paper
we adapt the argument from Luo and Tan to give an identity for hyperbolic tori
with one geodesic boundary or cusp in terms of dilogarithm functions on the set
of lengths of simple closed geodesics on the torus. As a corollary, we are also
able to express the Luo-Tan identity as a sum over all immersed three-holed
spheres $P$ which are embeddings when restricted to the interior of $P$.


title: Klein-Gordon-Maxwell equations in high dimensions

abstract:
  We prove the existence of a mountain-pass solution and the a priori bound
property for the electrostatic Klein-Gordon-Maxwell equations in high
dimension.


title: Positronium contribution to the electron g-2

abstract:
  The contribution of positronium to the electron $g$-2 ($a_e$) has been
computed in Ref. [1] and found to be of the same order of $\alpha$ as that of
five-loop perturbative QED. We confirm this result and correct a few errors in
its first derivation. As recently calculated in Ref. [2], a continuum
nonperturbative contribution to $a_e$ cancels one-half of the positronium one.
We show by explicit calculation that the remaining half is already included in
the five-loop perturbative result. We also show that it arises from the class
I(i) of five-loop diagrams containing only one closed electron loop.


title:
Quantum Monte Carlo calculations of neutron matter with non-local chiral
  interactions

abstract:
  We present fully non-perturbative quantum Monte Carlo calculations with
non-local chiral effective field theory (EFT) interactions for the ground state
properties of neutron matter. The equation of state, the nucleon chemical
potentials and the momentum distribution in pure neutron matter up to one and a
half times the nuclear saturation density are computed with a newly optimized
chiral EFT interaction at next-to-next-to-leading order. This work opens the
way to systematic order by order benchmarking of chiral EFT interactions, and
\emph{ab initio} prediction of nuclear properties while respecting the
symmetries of quantum chromodynamics.

categories: nucl-th astro-ph.SR cond-mat.quant-gas hep-ph


title:
Probing Radio Emission in Seyfert Galaxies on Parsec- and
  Kiloparsec-scales

abstract:
  Seyfert galaxies have traditionally been classified as radio-quiet active
galactic nuclei. A proper consideration of the nuclear optical emission however
proves that a majority of Seyferts are radio-loud. Kpc-scale radio
lobes/bubbles are in fact revealed in sensitive observations at low radio
frequencies of several Seyferts. Through the use of very long baseline
interferometry, we have been able to determine the direction of the
parsec-scale jets in some of these Seyfert galaxies. The misalignment between
the parsec-scale jets and the kpc-scale lobes that is typically observed, is
either suggestive of no connection between the two, or the presence of curved
jets that power the radio lobes. In this context, we briefly discuss our new
low radio frequency GMRT observations of two Seyfert galaxies with lobes.


title:
Consistent inference of a general model using the pseudo-likelihood
  method

abstract:
  Recently maximum pseudo-likelihood (MPL) inference method has been
successfully applied to statistical physics models with intractable
likelihoods. We use information theory to derive a relation between the
pseudo-likelihood and likelihood functions. We use this relation to show
consistency of the pseudo-likelihood method for a general model.


title:
Discrete dynamical systems from mutation-periodic quivers: examples and
  reduction

abstract:
  Several new mutation-periodic quivers of period higher than 1 are introduced
as well as the associated discrete dynamical systems. The reduction of these
systems is developed using either a presymplectic or a Poisson approach. The
presymplectic approach leads to a reduced system whose iteration map is
symplectic with respect to a log symplectic form. In the Poisson approach we
build a Poisson structure invariant under the iteration map, leading to a
reduced system whose variables are the Casimirs of such structure.


title:
Relationships Between Atomic Diffusion Mechanisms and Ensemble Transport
  Coefficients in Crystalline Polymorphs

abstract:
  Ionic transport in conventional ionic solids is generally considered to
proceed via independent diffusion events or "hops''. This assumption leads to
well-known Arrhenius expressions for transport coefficients, and is equivalent
to assuming diffusion is a Poisson process. Using molecular dynamics
simulations of the low-temperature B1, B3, and B4 AgI polymorphs, we have
compared rates of ion-hopping with corresponding Poisson distributions to test
the assumption of independent hopping in these common structure-types. In all
cases diffusion is a non-Poisson process, and hopping is strongly correlated in
time. In B1 the diffusion coefficient can be approximated by an Arrhenius
expression, though the physical significance of the parameters differs from
that commonly assumed. In low temperature B3 and B4 diffusion is characterised
by concerted motion of multiple ions in short closed loops. Diffusion
coefficients can not be expressed in a simple Arrhenius form dependent on
single-ion free-energies, and intrinsic diffusion must be considered a
many-body process.


title:
Mean-field theory is exact for the random-field model with long-range
  interactions

abstract:
  We study the random-field Ising model with long-range interactions and show
the exactness of the mean-field theory under certain mild conditions. This is a
generalization of the result of Mori for the non-random and spin-glass cases.
To treat random fields, we evoke the self-averaging property of a function of
random fields, without recourse to the replica method. The result is that the
mean-field theory gives the exact expression of the canonical free energy for
systems with power-decaying interactions if the power is smaller than or equal
to the spatial dimension.


title: Description of spectra of quadratic Pisot units

abstract:
  The spectrum of a real number $\beta>1$ is the set $X^{m}(\beta)$ of
$p(\beta)$ where $p$ ranges over all polynomials with coefficients restricted
to ${\mathcal A}=\{0,1,\dots,m\}$. For a quadratic Pisot unit $\beta$, we
determine the values of all distances between consecutive points and their
corresponding frequencies, by recasting the spectra in the frame of the
cut-and-project scheme. We also show that shifting the set ${\mathcal A}$ of
digits so that it contains at least one negative element, or considering
negative base $-\beta$ instead of $\beta$, the gap sequence of the generalized
spectrum is a coding of an exchange of three intervals.


title:
Statistical dynamics of continuous systems: perturbative and
  approximative approaches

abstract:
  We discuss general concept of Markov statistical dynamics in the continuum.
For a class of spatial birth-and-death models, we develop a perturbative
technique for the construction of statistical dynamics. Particular examples of
such systems are considered. For the case of Glauber type dynamics in the
continuum we describe a Markov chain approximation approach that gives more
detailed information about statistical evolution in this model.


title:
New constraints on the formation and settling of dust in the atmospheres
  of young M and L dwarfs

abstract:
  We obtained medium-resolution near-infrared spectra of seven young M9.5-L3
dwarfs classified in the optical. We aim to confirm the low surface gravity of
the objects in the NIR. We also test whether atmospheric models correctly
represent the formation and the settling of dust clouds in the atmosphere of
young late-M and L dwarfs. We used ISAAC at VLT to obtain the spectra of the
targets. We compared them to those of mature and young BD, and young late-type
companions to nearby stars with known ages, in order to identify and study
gravity-sensitive features. We computed spectral indices weakly sensitive to
the surface gravity to derive near-infrared spectral types. Finally, we found
the best fit between each spectrum and synthetic spectra from the BT-Settl 2010
and 2013 models. Using the best fit, we derived the atmospheric parameters of
the objects and identify which spectral characteristics the models do not
reproduce. We confirmed that our objects are young BD and we found NIR spectral
types in agreement with the ones determined at optical wavelengths. The
spectrum of the L2-gamma dwarf 2MASSJ2322-6151 reproduces well the spectrum of
the planetary mass companion 1RXS J1609-2105b. BT-Settl models fit the spectra
and the 1-5 $\mu$m SED of the L0-L3 dwarfs for temperatures between 1600-2000
K. But the models fail to reproduce the shape of the H band, and the NIR slope
of some of our targets. This fact, and the best fit solutions found with
super-solar metallicity are indicative of a lack of dust, in particular at high
altitude, in the cloud models. The modeling of the vertical mixing and of the
grain growth will be revised in the next version of the BT-Settl models. These
revisions may suppress the remaining non-reproducibilities.


title: Eisenstein series identities based on partial fraction decomposition

abstract:
  From the theory of modular forms, there are exactly $[(k-2)/6]$ linear
relations among the Eisenstein series $E_k$ and its products $E_{2i}E_{k-2i}\
(2\le i \le [k/4])$. We present explicit formulas among these modular forms
based on the partial fraction decomposition, and use them to determining a
basis of the space of modular forms of weight $k$ on ${\rm SL}_2({\mathbb Z})$.


title:
Characterization of the numbers which satisfy the height reducing
  property

abstract:
  Let $\alpha$ be a complex number. We show that there is a finite subset $F$
of the ring of the rational integers $\mathbb{Z}$, such that $F\left[
\alpha\right] =\mathbb{Z}\left[ \alpha\right]$, if and only if $\alpha$ is an
algebraic number whose conjugates, over the field of the rationals, are all of
modulus one, or all of modulus greater than one. This completes the answer to a
question, on the numbers satisfying the height reducing property, posed in [3].


title: Independent Set Reconfiguration in Cographs

abstract:
  We study the following independent set reconfiguration problem, called
TAR-Reachability: given two independent sets $I$ and $J$ of a graph $G$, both
of size at least $k$, is it possible to transform $I$ into $J$ by adding and
removing vertices one-by-one, while maintaining an independent set of size at
least $k$ throughout? This problem is known to be PSPACE-hard in general. For
the case that $G$ is a cograph (i.e. $P_4$-free graph) on $n$ vertices, we show
that it can be solved in time $O(n^2)$, and that the length of a shortest
reconfiguration sequence from $I$ to $J$ is bounded by $4n-2k$, if such a
sequence exists.
  More generally, we show that if $X$ is a graph class for which (i)
TAR-Reachability can be solved efficiently, (ii) maximum independent sets can
be computed efficiently, and which satisfies a certain additional property,
then the problem can be solved efficiently for any graph that can be obtained
from a collection of graphs in $X$ using disjoint union and complete join
operations. Chordal graphs are given as an example of such a class $X$.


title:
Gorenstein categories, singular equivalences and finite generation of
  cohomology rings in recollements

abstract:
  Given an artin algebra $\Lambda$ with an idempotent element $a$ we compare
the algebras $\Lambda$ and $a\Lambda a$ with respect to Gorensteinness,
singularity categories and the finite generation condition Fg for the
Hochschild cohomology. In particular, we identify assumptions on the idempotent
element $a$ which ensure that $\Lambda$ is Gorenstein if and only if $a\Lambda
a$ is Gorenstein, that the singularity categories of $\Lambda$ and $a\Lambda a$
are equivalent and that Fg holds for $\Lambda$ if and only if Fg holds for
$a\Lambda a$. We approach the problem by using recollements of abelian
categories and we prove the results concerning Gorensteinness and singularity
categories in this general setting. The results are applied to stable
categories of Cohen-Macaulay modules and classes of triangular matrix algebras
and quotients of path algebras.


title: Compact spaces, lattices, and absoluteness: a survey

abstract:
  Given a compact space in a fixed universe of set theory, one can naturally
define its interpretation in any ZFC extension of the universe. We investigate
the stability of some classes of compact spaces with respect to extensions of
this sort. We show that the class of Eberlein/Gul'ko compacta is stable (=
absolute). On the other hand, there are examples of Corson compacta which are
no longer Corson in some forcing extensions.
  All the material comes from the author's notes written between 2004 -- 2006.


title:
The Coherent Forward Scattering Amplitude in Transmission and Grazing
  Incidence M\"ossbauer Spectroscopy

abstract:
  The theory of both transmission and grazing incidence M\"ossbauer
spectroscopy is re-analyzed. Starting with the nuclear susceptibility tensor a
common concise first order perturbation formulation is given by introducing the
forward scattering amplitude into an anisotropic optical scheme. Formulae of
Blume and Kistner as well as those of Andreeva are re-derived for the forward
scattering and grazing incidence geometries, respectively. Limitations of
several previously intuitively introduced approximations are pointed out. The
grazing incidence integral propagation matrices are written in a form built up
from 2x2 matrix exponentials which is particularly suitable for numerical
calculations and practical fitting of both energy domain (conventional source
experiment) and time domain (synchrotron radiation experiment) M\"ossbauer
spectra.


title: Recent progress in smoothing estimates for evolution equations

abstract:
  This paper is a survey article of results and arguments from several of
authors' papers, and it describes a new approach to global smoothing problems
for dispersive and non-dispersive evolution equations based on ideas of
comparison principle and canonical transforms. For operators $a(D_x)$ of order
$m$ satisfying the dispersiveness condition $\nabla a(\xi)\neq0$, a range of
smoothing estimates is established. Especially, time-global smoothing estimates
for the operator $a(D_x)$ with lower order terms are the benefit of our new
method. These estimates are known to fail for general non-dispersive operators.
For the case when the dispersiveness breaks, we suggest a modification of the
smoothing estimate. It is equivalent to the usual estimate in the dispersive
case and is also invariant under canonical transformations for the operator
$a(D_x)$. Moreover, it does continue to hold for a variety of non-dispersive
operators $a(D_x)$, where $\nabla a(\xi)$ may become zero on some set. It is
interesting that this method allows us to carry out a global microlocal
reduction of equations to the translation invariance property of the Lebesgue
measure.


title:
Goethe's Faust and the Minimal Action Principle: a possible Universal
  message

abstract:
  This short note is devoted to non-proficient in physics. Its purpose is that
of proposing a possible universal connection between the definition of Action
given by Goethe in his ``Faust'' tragic play and the Hamilton's Principle of
the Minimal Action. This Principle is one of the most general ways of
formulating the dynamics of a physical system both in classical and in quantum
physics. The recent discovery of the long time searched Higgs particle may be
seen as the most spectacular successful confirmation of the Standard Model
formalism based on the Minimal Action Principle. Supported by this experimental
confirmation, we propose a possible general meaning of the Principle, inspired
by the Goethe's ``Faust'' tragic play.


title: The Near Earth Asteroid associations

abstract:
  We have made an extensive search for grouping amongst the near Earth
asteroids (NEAs). We used two D- functions and rigorous cluster analysis
approach. We have found sev- eral new groups (associations) among the NEAs: the
objects moving on similar orbits with small minimum orbital intersection
distances (MOID) with the Earth trajectory. Reliability of some of these groups
is quite high.


title: Glitch Statistics of Radio Pulsars : Multiple populations

abstract:
  There appears to be more than one statistically different populations in the
energy distribution of glitches, strongly indicative of different mechanisms
accessing different energy ranges responsible for them.


title: Stream and sporadic meteoroids associated with Near Earth Objects

abstract:
  NEOs come close to the Earth's orbit so that any dust ejected from them,
might be seen as a meteor shower. Orbits evolve rapidly, so that a similarity
of orbits at one given time is not suffcient to prove a relationship, orbital
evolution over a long time interval also has to be similar. Sporadic meteoroids
can not be associated with a single parent body, they can only be classified as
cometary or asteroidal. However, by considering one parameter criteria, many
sporadics are not classified properly therefore two parameter approach was
proposed.


title: The Krull-Gabriel dimension of discrete derived categories

abstract:
  We compute the Krull-Gabriel dimension of the category of perfect complexes
for finite dimensional algebras which are derived discrete.


title:
Dirichlet problem associated with Dunkl Laplacian on $W$-invariant open
  sets

abstract:
  Combining probabilistic and analytic tools from potential theory, we
investigate Dirichlet problems associated with the Dunkl Laplacian $\Delta_k$.
We establish, under some conditions on the open set $D\subset\R^d$, the
existence of a unique continuous function $h$ in the closure of $D$, twice
differentiable in $D$, such that $$ \Delta_kh=0
\quad\textrm{in}\;D\quad\textrm{and}\quad h=f\quad\textrm{on}\; \partial D. $$
We also give a probabilistic formula characterizing the solution $h$. The
function $f$ is assumed to be continuous on the Euclidean boundary $\partial D$
of $D$.


title: Majorana neutrinos and non minimal lepton mass textures

abstract:
  In the light of the recent measurement of the leptonic mixing angle
$\theta_{13}$, implications of the latest mixing data have been investigated
for non-minimal textures of lepton mass matrices assuming the neutrinos to be
Majorana like. Large number of possible texture specific lepton mass matrices
have been examined for their compatibility with the lepton mixing data in the
case of normal hierarchy, inverted hierarchy and degenerate scenario of
neutrino masses. Specifically, apart from other phenomenological quantities the
implications of the lepton mixing angle $\theta_{13}$ have been investigated on
the lightest neutrino mass as well as the effective Majorana mass $<m_{ee}>$.


title:
Nonuniform dichotomy spectrum and reducibility for nonautonomous
  difference equations

abstract:
  For nonautonomous linear difference equations, we introduce the notion of the
so-called nonuniform dichotomy spectrum and prove a spectral theorem. Moreover,
we introduce the notion of weak kinematical similarity and prove a reducibility
result by the spectral theorem.


title:
A Search for Time Dependent Neutrino Emission from Microquasars with the
  ANTARES Telescope

abstract:
  Results are presented on a search for neutrino emission from a sample of six
microquasars, based on the data collected by the ANTARES neutrino telescope
between 2007 and 2010. By means of appropriate time cuts, the neutrino search
has been restricted to the periods when the acceleration of relativistic jets
was taking place at the microquasars under study. The time cuts have been
chosen using the information from the X-ray telescopes RXTE/ASM and Swift/BAT,
and, in one case, the gamma-ray telescope Fermi/LAT. Since none of the searches
has produced a statistically significant signal, upper limits on the neutrino
fluences are derived and compared to the predictions from theoretical models.


title: Evolution of superconductivity in PrFe1-xCoxAsO with x = 0.0 to 1.0

abstract:
  We report the synthesis and physical property characterization of
PrFe1-xCoxAsO with x = 0.0 to 1.0. The studied samples are synthesized by solid
state reaction route via vacuum encapsulation method. The pristine compound
PrFeAsO does not show superconductivity, but rather exhibits a metallic step
like transition due to spin density wave ordering of Fe moments below 150 K,
followed by another upward step due to anomalous ordering of Pr moments at 12
K. Both the Fe-SDW and Pr-TN temperatures decrease monotonically with Co
substitution at Fe site. Superconductivity appears in a narrow range of x from
0.07 to 0.25 with maximum Tc at 11.12 K for x = 0.15. Samples, with x = 0.25
exhibit metallic behavior right from 300 K down to 2 K, without any Fe-SDW or
Pr-TN steps in resistivity. In fact, though Fe-SDW decreases monotonically, the
Pr-TN is disappeared even with x = 0.02. The magneto transport measurements
below 14 Tesla on superconducting polycrystalline Co doped PrFeAsO lead to
extrapolated values of the upper critical fields [Hc2(0)] of up to 60 Tesla.


title: Temperature evolution of magnetic flux rope in a failed solar eruption

abstract:
  In this presentation, we report for the first time the detailed temperature
evolution process of the magnetic flux rope in a failed solar eruption.
Occurred on January 05, 2013, the flux rope was impulsively accelerated to a
speed of ~ 400 km/s in the first minute, then decelerated and came to a
complete stop in two minutes. The failed eruption resulted in a large-size
high-lying (~ 100 Mm above the surface) high-temperature "fire ball" sitting in
the corona for more than two hours. The time evolution of the thermal structure
of the flux rope was revealed through the differential emission measure
analysis technique, which produced temperature maps using observations of the
Atmospheric Imaging Assembly on board Solar Dynamic Observatory. The average
temperature of the flux rope steadily increased from ~ 5 MK to ~ 10 MK during
the first nine minutes of the evolution, which was much longer than the rise
time (about three minutes) of the associated soft X-ray flare. We suggest that
the flux rope be heated by the energy release of the continuing magnetic
reconnection, different from the heating of the low-lying flare loops, which is
mainly produced by the chromospheric plasma evaporation. The loop arcade
overlying the flux rope was pushed up by ~ 10 Mm during the attempted eruption.
The pattern of the velocity variation of the loop arcade strongly suggests that
the failure of the eruption be caused by the strapping effect of the overlying
loop arcade.


title: A route to thermalization in the $\alpha$-Fermi-Pasta-Ulam system

abstract:
  We study the original $\alpha$-Fermi-Pasta-Ulam (FPU) system with $N=16,32$
and $64$ masses connected by a nonlinear quadratic spring. Our approach is
based on resonant wave-wave interaction theory, i.e. we assume that, in the
weakly nonlinear regime (the one in which Fermi was originally interested), the
large time dynamics is ruled by exact resonances. After a detailed analysis of
the $\alpha$-FPU equation of motion, we find that the first non trivial
resonances correspond to six-wave interactions. Those are precisely the
interactions responsible for the thermalization of the energy in the spectrum.
We predict that for small amplitude random waves the time scale of such
interactions is extremely large and it is of the order of $1/\epsilon^8$, where
$\epsilon$ is the small parameter in the system. The wave-wave interaction
theory is not based on any threshold: equipartition is predicted for arbitrary
small nonlinearity. Our results are supported by extensive numerical
simulations. A key role in our finding is played by the {\it Umklapp} (flip
over) resonant interactions, typical of discrete systems. The thermodynamic
limit is also briefly discussed.

categories: nlin.CD cond-mat.stat-mech math-ph math.MP nlin.SI physics.class-ph


title: Balance equations-based properties of the Rabi Hamiltonian

abstract:
  A stationary physical system satisfies peculiar balance conditions involving
mean values of appropriate observables. In this paper we show how to deduce
such quantitative links, named balance equations, demonstrating as well their
usefulness in bringing to light physical properties of the system without
solving the Schrodinger equation. The knowledge of such properties in the case
of Rabi Hamiltonian is exploit to provide arguments to make easier the
variational engineering of the ground state of this model.


title: Fast Numerical Nonlinear Fourier Transforms

abstract:
  The nonlinear Fourier transform, which is also known as the forward
scattering transform, decomposes a periodic signal into nonlinearly interacting
waves. In contrast to the common Fourier transform, these waves no longer have
to be sinusoidal. Physically relevant waveforms are often available for the
analysis instead. The details of the transform depend on the waveforms
underlying the analysis, which in turn are specified through the implicit
assumption that the signal is governed by a certain evolution equation. For
example, water waves generated by the Korteweg-de Vries equation can be
expressed in terms of cnoidal waves. Light waves in optical fiber governed by
the nonlinear Schr\"odinger equation (NSE) are another example. Nonlinear
analogs of classic problems such as spectral analysis and filtering arise in
many applications, with information transmission in optical fiber, as proposed
by Yousefi and Kschischang, being a very recent one. The nonlinear Fourier
transform is eminently suited to address them -- at least from a theoretical
point of view. Although numerical algorithms are available for computing the
transform, a "fast" nonlinear Fourier transform that is similarly effective as
the fast Fourier transform is for computing the common Fourier transform has
not been available so far. The goal of this paper is to address this problem.
Two fast numerical methods for computing the nonlinear Fourier transform with
respect to the NSE are presented. The first method achieves a runtime of
$O(D^2)$ floating point operations, where $D$ is the number of sample points.
The second method applies only to the case where the NSE is defocusing, but it
achieves an $O(D\log^2D)$ runtime. Extensions of the results to other evolution
equations are discussed as well.

categories: cs.IT math.IT math.NA nlin.SI physics.comp-ph


title:
Double inclusive cross-sections for gluon production in collision of two
  projectiles on two targets in the BFKL approach

abstract:
  Double inclusive cross-sections for gluon production in collision of two
nucleons with two nucleons are studied in the BFKL approach. Various
contributions include emission from the pomerons attached to the participants,
from the BFKL interactions between these pomerons and from the intermediate BKP
state. The last contribution may be observable provided the growth with energy
of the pomeron contribution is tamed in accordance with unitarity. Possibility
of long-range azimuthal correlations due to the BKP state are discussed.


title: Generalized Signal Alignment For MIMO Two-Way X Relay Channels

abstract:
  We study the degrees of freedom (DoF) of MIMO two-way X relay channels.
Previous work studied the case $N < 2M$, where $N$ and $M$ denote the number of
antennas at the relay and each source, respectively, and showed that the
maximum DoF of $2N$ is achievable when $N \leq \lfloor\frac{8M}{5}\rfloor$ by
applying signal alignment (SA) for network coding and interference cancelation.
This work considers the case $N>2M$ where the performance is limited by the
number of antennas at each source node and conventional SA is not feasible. We
propose a \textit{generalized signal alignment} (GSA) based transmission
scheme. The key is to let the signals to be exchanged between every source node
align in a transformed subspace, rather than the direct subspace, at the relay
so as to form network-coded signals. This is realized by jointly designing the
precoding matrices at all source nodes and the processing matrix at the relay.
Moreover, the aligned subspaces are orthogonal to each other. By applying the
GSA, we show that the DoF upper bound $4M$ is achievable when $M \leq
\lfloor\frac{2N}{5}\rfloor$ ($M$ is even) or $M \leq
\lfloor\frac{2N-1}{5}\rfloor$ ($M$ is odd). Numerical results also demonstrate
that our proposed transmission scheme is feasible and effective.


title: A comparison of Monte Carlo generators

abstract:
  A comparison of GENIE, NEUT, NUANCE, and NuWro Monte Carlo neutrino event
generators is presented using a set of four observables: protons multiplicity,
total visible energy, most energetic proton momentum, and $\pi^+$
two-dimensional energy vs cosine distribution.


title:
Heavy fermion and Kondo lattice behavior in the itinerant ferromagnet
  CeCrGe3

abstract:
  Physical properties of polycrystalline CeCrGe$_{3}$ and LaCrGe$_{3}$ have
been investigated by x-ray absorption spectroscopy, magnetic susceptibility
$\chi(T)$, isothermal magnetization M(H), electrical resistivity $\rho(T)$,
specific heat C($T$) and thermoelectric power S($T$) measurements. These
compounds are found to crystallize in the hexagonal perovskite structure (space
group \textit{P6$_{3}$/mmc}), as previously reported. The $\rho(T)$, $\chi(T)$
and C($T$) data confirm the bulk ferromagnetic ordering of itinerant Cr moments
in LaCrGe$_{3}$ and CeCrGe$_{3}$ with $T_{C}$ = 90 K and 70 K respectively. In
addition a weak anomaly is also observed near 3 K in the C($T$) data of
CeCrGe$_{3}$. The T dependences of $\rho$ and finite values of Sommerfeld
coefficient $\gamma$ obtained from the specific heat measurements confirm that
both the compounds are of metallic character. Further, the $T$ dependence of
$\rho$ of CeCrGe$_{3}$ reflects a Kondo lattice behavior. An enhanced $\gamma$
of 130 mJ/mol\,K$^{2}$ together with the Kondo lattice behavior inferred from
the $\rho(T)$ establish CeCrGe$_{3}$ as a moderate heavy fermion compound with
a quasi-particle mass renormalization factor of $\sim$ 45.


title:
An Extended H\"uckel Study of the Electronic Properties of III-V
  Compounds and Their Alloys

abstract:
  In this work, we performed tight binding calculations of the electronic
structure of III-V semiconductors compounds and their alloys based on the
Extended H\"uckel Theory (EHT), where the H\"uckel parameters for the binary
compounds were generated following a simulated annealing procedure. In
particular, this article is focused on the dependency between band gap and the
applied pressure and also the alloy composition.


title:
Nuclear effects in neutrino and antineutrino CCQE scattering at MINERvA
  kinematics

abstract:
  We compare the charged-current quasielastic neutrino and antineutrino
observables obtained in two different nuclear models, the phenomenological
SuperScaling Approximation and the Relativistic Mean Field approach, with the
recent data published by the MINERvA Collaboration. Both models provide a good
description of the data without the need of an ad hoc increase in the mass
parameter in the axial-vector dipole form factor. Comparisons are also made
with the MiniBooNE results where different conclusions are reached.


title:
On Jordan type bounds for finite groups of diffeomorphisms of
  3-manifolds and Euclidean spaces

abstract:
  By a classical result of Jordan, each finite subgroup G of a complex linear
group GL_n(C) has an abelian subgroup whose index in G is bounded by a constant
depending only on n. We consider the problem if this remains true for finite
subgroups G of the diffeomorphism group of a smooth manifold, and show that it
is true for all compact 3-manifolds as well as for Euclidean spaces of
dimension n < 7. The question remains open at present e.g. for odd-dimensional
spheres of dimension greater or equal to five, and for Euclidean spaces of
dimension greater or equal to seven.


title:
Relative entropy minimizing noisy non-linear neural network to
  approximate stochastic processes

abstract:
  A method is provided for designing and training noise-driven recurrent neural
networks as models of stochastic processes. The method unifies and generalizes
two known separate modeling approaches, Echo State Networks (ESN) and Linear
Inverse Modeling (LIM), under the common principle of relative entropy
minimization. The power of the new method is demonstrated on a stochastic
approximation of the El Nino phenomenon studied in climate research.


title:
New LDPC Codes Using Permutation Matrices with Higher Girth than QC-LDPC
  Codes Constructed by Fossorier

abstract:
  In the literatures, it is well-known that Fossorier code has the girth among
LDPC codes. In this paper, we introduce a new class of low-density parity-check
(LDPC) codes, with higher girth than other previous constructed codes.
Especially we proposed a new method to construct LDPC codes using non fixed
shift permutation matrices and full based matrices with higher girth than codes
constructed by Fossorier.


title:
Energy of Ni/Ni$_{3}$Al Interface: a Temperature-Dependent Theoretical
  Study

abstract:
  Using plane wave {\textit{ab-initio}} and Monte Carlo techniques, the
Ni/Ni$_{3}$Al interfacial energy is studied and the results from the different
techniques are critically compared. Two issues deserved special attention: the
dependency of the interface energy with the supercell size, for the
{\textit{ab-initio}} calculations, and the temperature dependence of the
interface energy. The calculations show that from 0K up to 1000 K that energy
decreases by 1 mJ/m$^2$.


title:
A note on 'Exact and approximate methods for a one-dimensional minimax
  bin-packing problem' [Annals of Operations Research (2013) 206:611-626]

abstract:
  In a recent paper, Brusco, K\"ohn and Steinley [Ann. Oper. Res. 206:611-626
(2013)] conjecture that the 2 bins special case of the one-dimensional minimax
bin-packing problem with bin size constraints might be solvable in polynomial
time. In this note, we show that this problem is NP-hard for the special case
and that it is strongly NP-hard for the general problem. We also propose a
pseudo-polynomial algorithm for the special case and a constructive heuristic
for the general problem.


title: Asynchronous Transmission over Single-User State-Dependent Channels

abstract:
  Several channels with asynchronous side information are introduced. We first
consider single-user state-dependent channels with asynchronous side
information at the transmitter. It is assumed that the state information
sequence is a possibly delayed version of the state sequence, and that the
encoder and the decoder are aware of the fact that the state information might
be delayed. It is additionally assumed that an upper bound on the delay is
known to both encoder and decoder, but other than that, they are ignorant of
the actual delay. We consider both the causal and the noncausal cases and
present achievable rates for these channels, and the corresponding coding
schemes. We find the capacity of the asynchronous Gel'fand-Pinsker channel with
feedback. Finally, we consider a memoryless state dependent channel with
asynchronous side information at both the transmitter and receiver, and
establish a single-letter expression for its capacity.


title: Small product sets in compact groups

abstract:
  We show in this paper that a sub-critical pair $(A,B)$ of sufficiently
"spread-out" Borel sets in a compact and second countable group $K$ with an
\emph{abelian} identity component, must reduce to a Sturmian pair in either
$\bT$ or $\bT \rtimes \{-1,1\}$. This extends a classical result of Kneser.


title: A local Echo State Property through the largest Lyapunov exponent

abstract:
  Echo State Networks are efficient time-series predictors, which highly depend
on the value of the spectral radius of the reservoir connectivity matrix. Based
on recent results on the mean field theory of driven random recurrent neural
networks, enabling the computation of the largest Lyapunov exponent of an ESN,
we develop a cheap algorithm to establish a local and operational version of
the Echo State Property.


title: The role of potassium orbitals in the metallic behavior of K3picene

abstract:
  Detailed electronic structure calculations of picene clusters doped by
potassium modeling the crystalline K3picene structure show that while two
electrons are completely transferred from potassium atoms to the LUMO of
pristine picene, the third one remains closely attached to both material
components. Multiconfigurational analysis is necessary to show that many
structures of almost degenerate total energies compete to define the cluster
ground state. Our results prove that the 4s orbital of potassium should be
included in any interaction model describing the material. We propose a quarter
filled two orbital model as the most simple model capable of describing the
electronic structure of K-intercalated picene. Precise solutions obtained by a
development of Lanczos method show low energy electronic excitations involving
orbitals located at different positions. Consequently, metallic transport is
possible in spite of the clear dominance of interaction over hopping.


title: CaCu3Ti4O12 (CCTO) ceramics for capacitor applications

abstract:
  CaCu3Ti4O12 (CCTO) ceramics are potential candidates for capacitor
applications due to their large dielectric permittivity (e') values of up to
300 000. The underlying mechanism for the high e' is an internal barrier layer
capacitor (IBLC) structure of insulating grain boundaries (GB) and conducting
grain interiors (bulk). This behaviour is reviewed and discussed in detail. The
origin of the IBLC structure is attributed to a small Cu non-stoichiometry in
nominally insulating CaCu3Ti4O12, which varies between the GBs and bulk. Such
non-stoichiometry effects are studied in detail by analyzing bulk ceramics of
different composition within the ternary CaO-CuO-TiO2 phase diagram using X-ray
diffraction (XRD), scanning electron microscopy (SEM) and impedance
spectroscopy (IS). At least two defect mechanisms are suggested to exist. It is
further shown that the development of the defect mechanisms in CCTO and the
concomitant formation of the IBLC structure strongly depend on the processing
conditions of CCTO ceramic pellets such as the sintering temperature. Nominally
stoichiometric CCTO bulk ceramics sintered at different temperatures are
analyzed using XRD, SEM and IS. The performance of CCTO ceramics for IBLC
applications is controlled by subtle modifications in the compound
stoichiometry that is strongly dependent on the ceramic sintering temperature.


title: Loop exponent in DNA bubble dynamics

abstract:
  Dynamics of DNA bubbles are of interest for both statistical physics and
biology. We present exact solutions to the Fokker-Planck equation governing
bubble dynamics in the presence of a long-range entropic interaction. The
complete meeting time and meeting position probability distributions are
derived from the solutions. Probability distribution functions reflect the
value of the loop exponent of the entropic interaction. Our results extend
previous results which concentrated mainly on the tails of the probability
distribution functions and open a way to determining the strength of the
entropic interaction experimentally which has been a matter of recent
discussions. Using numerical integration, we also discuss the influence of the
finite size of a DNA chain on the bubble dynamics. Analogous results are
obtained also for the case of subdiffusive dynamics of a DNA bubble in a
heteropolymer, revealing highly universal asymptotics of meeting time and
position probability functions.


title:
An iterative method for the construction of N-body galaxy models in
  collisionless equilibrium

abstract:
  (Abridged) We describe a new iterative approach for the realization of
equilibrium N-body systems for given density distributions. Our method uses
elements of Schwarzschild's technique and of the made-to-measure method, but is
based on a different principle. Starting with some initial assignment of
particle velocities, we calculate their orbits using a flexible tree-based
force algorithm in the stationary potential of the target density distribution.
The difference of the time-averaged density response produced by these orbits
with respect to the initial density configuration is characterized through a
merit function, and a stationary solution of the collisionless Boltzmann
equation is found by minimizing this merit function directly by iteratively
adjusting the initial velocities. Because the distribution function is in
general not unique for a given density structure, we augment the merit function
with additional constraints that single out a desired target solution. We do
this for broad classes of axisymmetric density distributions by numerically
solving the Jeans equations to obtain the second velocity moments, which are
then imposed as further constraints in the optimization process. The velocity
adjustment is carried out with a stochastic process in which new velocities are
randomly drawn from an approximate solution of the distribution function, but
are kept only when they improve the fit. Our method converges rapidly and is
flexible enough to allow the construction of solutions with third integrals of
motion, including disk galaxies with realistic velocity distributions. We
demonstrate that the new method reproduces analytic distribution functions
where they are known (such as the Hernquist sphere), and that it yields very
stable N-body realizations for a variety of examples of compound galaxy models,
considerably improving on widely used moment-based approaches.


title: Using Twitter to Model the EUR/USD Exchange Rate

abstract:
  Fast, global, and sensitively reacting to political, economic and social
events of any kind, these are attributes that social media like Twitter share
with foreign exchange markets. The leading assumption of this paper is that
information which can be distilled from public debates on Twitter has
predictive content for exchange rate movements. This assumption prompted a
Twitter-based exchange rate model that harnesses regARIMA analyses for
short-term out-of-sample ex post forecasts of the daily closing prices of
EUR/USD spot exchange rates. The analyses used Tweet counts collected from
January 1, 2012 - September 27, 2013. To identify concepts mentioned on Twitter
with a predictive potential the analysis followed a 2-step selection. Firstly,
a heuristic qualitative analysis assembled a long list of 594 concepts, e.g.,
Merkel, Greece, Cyprus, crisis, chaos, growth, unemployment expected to covary
with the ups and downs of the EUR/USD exchange rate. Secondly, cross-validation
using window averaging with a fixed-sized rolling origin was deployed to select
concepts and corresponding univariate time series that had error scores below
chance level as defined by the random walk model. With regard to a short list
of 17 concepts (covariates), in particular SP (Standard & Poor's) and risk, the
out-of-sample predictive accuracy of the Twitter-based regARIMA model was found
to be repeatedly better than that obtained from both the random walk model and
a random noise covariate in 1-step ahead forecasts of the EUR/USD exchange
rate. This advantage was evident on the level of forecast error metrics (MSFE,
MAE) when a majority vote over different estimation windows was conducted. The
results challenge the semi-strong form of the efficient market hypothesis
(Fama, 1970, 1991) which when applied to the FX market maintains that all
publicly available information is already integrated into exchange rates.


title: Rack homology and conjectural Leibniz homology

abstract:
  This article presents results being consistent with conjectures of J.-L.
Loday about the existence and properties of a Leibniz homology for groups.
Introducing L-sets we prove that (pointed) rack homology has properties this
conjectural Leibniz homology should satisfy, namely the existence of a
coZinbiel coalgebra structure on rack homology and the existence of a non
trivial natural cocommutative coalgebra morphism from the rack homology of a
group to its Eilenberg-MacLane homology. The end of the paper treats the
particular cases of the linear group and of abelian groups. We prove the
existence of a connected coZinbiel-associative bialgebra structure on their
rack homology.


title: Confinement and Mayer cluster expansions

abstract:
  In these notes, we study a class of grand-canonical partition functions with
a kernel depending on a small parameter $\epsilon$. This class is directly
relevant to Nekrasov partition functions of $\mathcal{N}=2$ SUSY gauge theories
on the 4d $\Omega$-background, for which $\epsilon$ is identified with one of
the equivariant deformation parameter. In the Nekrasov-Shatashvili limit
$\epsilon\to0$, we show that the free energy is given by an on-shell effective
action. The equations of motion take the form of a TBA equation. The free
energy is identified with the Yang-Yang functional of the corresponding system
of Bethe roots. We further study the associated canonical model that takes the
form of a generalized matrix model. Confinement of the eigenvalues by the
short-range potential is observed. In the limit where this confining potential
becomes weak, the collective field theory formulation is recovered. Finally, we
discuss the connection with the alternative expression of instanton partition
functions as sums over Young tableaux.

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


title:
Signatures of superconducting and pseudogap phases in ultrafast
  transient reflectivity of Ca(Fe0.927Co0.073)2As2

abstract:
  We present femtosecond time-resolved pump-probe spectroscopic studies of a
pseudogap (PG) along with the superconducting (SC) gap in an overdoped iron
pnictide Ca(Fe0.927Co0.073)2As2. It is seen that the temperature evolution of
the photoexcited quasiparticle (QP) relaxation dynamics, coherently excited
A1g-symmetric optical phonon and two acoustic phonon dynamics behave
anomalously in the vicinity of the superconducting transition temperature Tc. A
continuous change in the sign of the experimentally measured transient
differential reflectivity Delta_R/R signal at the zero time-delay between the
pump and probe pulses at a temperature of ~200 K is inferred as an evidence of
the emergence of the PG phase around that temperature. This behavior is
independent of the pump photon energy and occurs for crystals without the spin
density wave phase transition.


title:
Driven colloidal suspensions in confinement and density functional
  theory: Microstructure and wall-slip

abstract:
  We theoretically investigate general properties of driven (sheared) colloidal
suspensions in confinement, based on methods of classical density functional
theory. In the absence of an exact closed (Smoluchowski-) equation for the
one-particle density under shear, we formulate a set of general conditions for
approximations, and show that a simple closure fulfills them. The exact
microscopic stress tensor is identified. Exemplifying the situation near a wall
(oriented parallel to the direction of shear), we note that the microscopic
shear stress is not necessarily homogeneous. Formulating a second equation
additional to the Smoluchowski equation, we achieve a homogeneous shear stress,
and thereby compute the local flow velocity near the wall. This finally leads
to a slip length of the complex fluid at the wall.


title:
Discrete-time gradient flows and law of large numbers in Alexandrov
  spaces

abstract:
  We develop the theory of discrete-time gradient flows for convex functions on
Alexandrov spaces with arbitrary upper or lower curvature bounds. We employ
different resolvent maps in the upper and lower curvature bound cases to
construct such a flow, and show its convergence to a minimizer of the potential
function. We also prove a stochastic version, a generalized law of large
numbers for convex function valued random variables, which not only extends
Sturm's law of large numbers on nonpositively curved spaces to arbitrary lower
or upper curvature bounds, but this version seems new even in the Euclidean
setting. These results generalize those in nonpositively curved spaces (partly
for squared distance functions) due to Ba\v{c}\'ak, Jost, Sturm and others, and
the lower curvature bound case seems entirely new.


title: A quark-meson coupling model based on Bogoliubov's model of the nucleon

abstract:
  The quark-meson coupling model due to Guichon is formulated on the basis of
the independent quark model of the nucleon proposed by Bogoliubov and is
applied to a phenomenological description of symmetric nuclear matter. The
model predicts, at saturation density, the compressibility $K=249$ MeV and the
quark effective mass $m_q^*= 249.1$ MeV, {the effective nucleon mass being
$M^*=747.3$ MeV}. The predicted nucleon mass radius is $r=0.93$ fm.


title:
Selecting superluminous supernovae in faint galaxies from the first year
  of the Pan-STARRS1 Medium Deep Survey

abstract:
  The Pan-STARRS1 (PS1) survey has obtained imaging in 5 bands (grizy_P1) over
10 Medium Deep Survey (MDS) fields covering a total of 70 square degrees. This
paper describes the search for apparently hostless supernovae (SNe) within the
first year of PS1 MDS data with an aim of discovering new superluminous
supernovae (SLSNe). A total of 249 hostless transients were discovered down to
a limiting magnitude of M_AB ~ 23.5, of which 76 were classified as Type Ia
SNe. There were 57 SNe with complete light curves that are likely core-collapse
SNe (CCSNe) or SLSNe and 12 of these have had spectra taken. Of these 12
hostless, non-Type Ia SNe, 7 were SLSNe of Type Ic at redshifts between
0.5-1.4. This illustrates that the discovery rate of Type Ic SLSNe can be
maximised by concentrating on hostless transients and removing normal SNe Ia.
We present data for two new possible SLSNe; PS1-10pm (z = 1.206) and PS1-10ahf
(z = 1.1), and estimate the rate of SLSNe-Ic to be between 3^{+3}_{-2} *
10^{-5} and 8^{+2}_{-1} * 10^{-5} of the CCSNe rate within 0.3 <= z <= 1.4 by
applying a Monte-Carlo technique. The rate of slowly evolving, SN2007bi-like
explosions is estimated as a factor of 10 lower than this range.


title: Singular Moduli that are Algebraic Units

abstract:
  We prove that only finitely many $j$-invariants of elliptic curves with
complex multiplication are algebraic units. A rephrased and generalized version
of this result resembles Siegel's Theorem on integral points of algebraic
curves.


title: Suzaku Discovery of Fe K-Shell Line from the O-Rich SNR G292.0+1.8

abstract:
  We report the Suzaku/XIS results of the Galactic oxygen-rich supernova
remnant (SNR), G292.0+1.8, a remnant of a core-collapse supernova. The X-ray
spectrum of G292.0+1.8 consists of two type plasmas, one is in collisional
ionization equilibrium (CIE) and the other is in non-equilibrium ionization
(NEI). The CIE plasma has nearly solar abundances, and hence would be
originated from the circumstellar and interstellar mediums. The NEI plasma has
super-solar abundances, and the abundance pattern indicates that the plasma
originates from the supernova ejecta with a main sequence of 30-35 Msolar. Iron
K-shell line at energy of 6.6 keV is detected for the first time in the NEI
plasma.


title:
Exotic quantum holonomy and higher-order exceptional points in quantum
  kicked tops

abstract:
  The correspondence between exotic quantum holonomy that occurs in families of
Hermitian cycles, and exceptional points (EPs) for non-Hermitian quantum theory
is examined in quantum kicked tops. Under a suitable condition, an explicit
expressions of the adiabatic parameter dependencies of quasienergies and
stationary states, which exhibit anholonomies, are obtained. It is also shown
that the quantum kicked tops with the complexified adiabatic parameter have a
higher order EP, which is broken into lower order EPs with the application of
small perturbations. The stability of exotic holonomy against such bifurcation
is demonstrated.


title: Product Evaluation In Elliptical Helical Pipe Bending

abstract:
  This research proposes a computation approach to address the evaluation of
end product machining accuracy in elliptical surfaced helical pipe bending
using 6dof parallel manipulator as a pipe bender. The target end product is
wearable metal muscle supporters used in build-to-order welfare product
manufacturing. This paper proposes a product testing model that mainly corrects
the surface direction estimation errors of existing least squares ellipse
fittings, followed by arc length and central angle evaluations. This
post-machining modelling requires combination of reverse rotations and
translations to a specific location before accuracy evaluation takes place,
i.e. the reverse comparing to pre-machining product modelling. This specific
location not only allows us to compute surface direction but also the amount of
excessive surface twisting as a rotation angle about a specified axis, i.e.
quantification of surface torsion. At first we experimented three ellipse
fitting methods such as, two least-squares fitting methods with Bookstein
constraint and Trace constraint, and one non- linear least squares method using
Gauss-Newton algorithm. From fitting results, we found that using Trace
constraint is more reliable and designed a correction filter for surface
torsion observation. Finally we apply 2D total least squares line fitting
method with a rectification filter for surface direction detection.


title:
Numerical solving the boundary value problem for fractional powers of
  elliptic operators

abstract:
  A boundary value problem for a fractional power of the second-order elliptic
operator is considered. It is solved numerically using a time-dependent problem
for a pseudo-parabolic equation. For the auxiliary Cauchy problem, the standard
two-level schemes with weights are applied. Stability conditions are obtained
for the fully discrete schemes under the consideration. The numerical results
are presented for a model two-dimensional boundary value problem wit a
fractional power of an elliptic operator. The dependence of accuracy on grids
in time and in space is studied.


title: Vertical Clustering of 3D Elliptical Helical Data

abstract:
  This research proposes an effective vertical clustering strategy of 3D data
in an elliptical helical shape based on 2D geometry. The clustering object is
an elliptical cross-sectioned metal pipe which is been bended in to an
elliptical helical shape which is used in wearable muscle support designing for
welfare industry. The aim of this proposed method is to maximize the vertical
clustering (vertical partitioning) ability of surface data in order to run the
product evaluation process addressed in research [2]. The experiment results
prove that the proposed method outperforms the existing threshold no of
clusters that preserves the vertical shape than applying the conventional 3D
data. This research also proposes a new product testing strategy that provides
the flexibility in computer aided testing by not restricting the sequence
depending measurements which apply weight on measuring process. The clustering
algorithms used for the experiments in this research are self-organizing map
(SOM) and K-medoids.


title: On Schwinger's formula for pair production

abstract:
  We present some comments on Schwinger's calculation of electron-positron
production in a prescribed constant electric field. The range of validity of 2
Im \mathcal{L}^(1)(E) is discussed thoroughly and limiting cases are provided.


title: The spotty donor star in the X-ray transient Cen X-4

abstract:
  We accurately determine the fundamental system parameters of the neutron-star
X-ray transient Cen X-4 solely using phase-resolved high-resolution UVES
spectroscopy. We first determine the radial-velocity curve of the secondary
star and then model the shape of the phase-resolved absorption line profiles
using an X-ray binary model. The model computes the exact rotationally
broadened phase-resolved spectrum and does not depend on assumptions about the
rotation profile, limb-darkening coefficients and the effects of contamination
from an accretion disk. We determine the secondary star-to-neutron star binary
mass ratio to be 0.1755+/-0.0025, which is an order of magnitude more accurate
than previous estimates. We also constrain the inclination angle to be 32 (+8;
-2) degrees, Combining these values with the results of the radial velocity
study gives a neutron star mass of 1.94 (+0.37; -0.85) Msun consistent with
previous estimates. Finally, we perform the first Roche tomography
reconstruction of the secondary star in an X-ray binary. The tomogram reveals
surface inhomogeneities that are due to the presence of cool starspots. A large
cool polar spot, similar to that seen in Doppler images of rapidly-rotating
isolated stars is present on the Northern hemisphere of the K7 secondary star
and we estimate that about 4 per cent of the total surface area of the donor
star is covered with spots. This evidence for starspots supports the idea that
magnetic braking plays an important role in the evolution of low-mass X-ray
binaries.


title:
A characterization of almost universal ternary quadratic polynomials
  with odd prime power conductor

abstract:
  An integral quadratic polynomial (with positive definite quadratic part) is
called almost universal if it represents all but finitely many positive
integers. In this paper, we introduce the conductor of a quadratic polynomial,
and give an effective characterization of almost universal ternary quadratic
polynomials with odd prime power conductor.


title:
Complements of hypersurfaces, variation maps and minimal models of
  arrangements

abstract:
  We prove the minimality of the CW-complex structure for complements of
hyperplane arrangements in $\mathbb C^n$ by using the theory of Lefschetz
pencils and results on the variation maps within a pencil of hyperplanes. This
also provides a method to compute the Betti numbers of complements of
arrangements via global polar invariants.


title: Links with small lattice stick numbers

abstract:
  Knots and links have been considered to be useful models for structural
analysis of molecular chains such as DNA and proteins. One quantity that we are
interested on molecular links is the minimum number of monomers necessary to
realize them. In this paper we consider every link in the cubic lattice.
Lattice stick number $s_L(L)$ of a link $L$ is defined to be the minimal number
of sticks required to construct a polygonal representation of the link in the
cubic lattice. Huh and Oh found all knots whose lattice stick numbers are at
most 14. They proved that only the trefoil knot $3_1$ and the figure-8 knot
$4_1$ have lattice stick numbers 12 and 14, respectively. In this paper we find
all links with more than one component whose lattice stick numbers are at most
14. Indeed we prove combinatorically that $s_L(2^2_1)=8$, $s_L(2^2_1 \sharp
2^2_1)=s_L(6^3_2)=s_L(6^3_3)=12$, $s_L(4^2_1)=13$, $s_L(5^2_1)=14$ and any
other non-split links have stick numbers at least 15.


title:
Fermi sea term in the relativistic linear muffin-tin-orbital transport
  theory for random alloys

abstract:
  We present a formulation of the so-called Fermi sea contribution to the
conductivity tensor of spin-polarized random alloys within the fully
relativistic tight-binding linear muffin-tin-orbital (TB-LMTO) method and the
coherent potential approximation (CPA). We show that the configuration
averaging of this contribution leads to the CPA-vertex corrections that are
solely due to the energy dependence of the average single-particle propagators.
Moreover, we prove that this contribution is indispensable for the invariance
of the anomalous Hall conductivities with respect to the particular LMTO
representation used in numerical implementation. Ab initio calculations for
cubic ferromagnetic 3d transition metals (Fe, Co, Ni) and their random binary
alloys (Ni-Fe, Fe-Si) indicate that the Fermi sea term is small against the
dominating Fermi surface term. However, for more complicated structures and
systems, such as hexagonal cobalt and selected ordered and disordered Co-based
Heusler alloys, the Fermi sea term plays a significant role in the quantitative
theory of the anomalous Hall effect.


title: Surface patterns in drying films of silica colloidal dispersions

abstract:
  We report an experimental study on the drying of silica colloidal
dispersions. Here we focus on a surface instability occurring in a drying paste
phase before crack formation which affects the final film quality. Observations
at macroscopic and microscopic scales reveal the occurrence of the instability,
and the morphology of the film surface. Furthermore, we show that the addition
of adsorbing polymers on silica particles can be used to suppress the
instability under particular conditions of molecular weight and concentration.
We relate this suppression to the increase of the paste elastic modulus.


title: 11Be(beta-p), a quasi-free neutron decay?

abstract:
  We have observed beta-delayed proton emission from the neutron-rich nucleus
11Be by analysing a sample collected at the ISOLDE facility at CERN with
accelerator mass spectrometry (AMS). With a branching ratio of (8.4 +- 0.6)
10^{-6} the strength of this decay mode, as measured by the B(GT)-value, is
unexpectedly high. The result is discussed within a simple single-particle
model and could be interpreted as a quasi-free decay of the 11Be halo neutron
into a single-proton state.


title:
Detecting scattered light from low-mass molecular cores at 3.6 $\mu$m -
  Impact of global effects on the observation of coreshine

abstract:
  Recently discovered scattered light at 3-5 $\mu$m from low-mass cores
(so-called "coreshine") reveals the presence of grains around 1 $\mu$m, which
is larger than the grains found in the low-density interstellar medium. But
only about half of the 100+ cores investigated so far show the effect. This
prompts further studies on the origin of this detection rate. From the 3D
continuum radiative transfer equation, we derive the expected scattered light
intensity from a core placed in an arbitrary direction seen from Earth. We use
the approximation of single scattering, consider extinction up to 2nd-order
Taylor approximation, and neglect spatial gradients in the dust size
distribution. The impact of the directional characteristics of the scattering
on the detection of scattered light from cores is calculated for a given grain
size distribution, and local effects like additional radiation field components
are discussed. The surface brightness profiles of a core with a 1D density
profile are calculated for various Galactic locations, and the results are
compared to the approximate detection limits. We find that for optically thin
radiation and a constant size distribution, a simple limit for detecting
scattered light from a low-mass core can be derived that holds for grains with
sizes smaller than 0.5 $\mu$m. The extinction by the core prohibits detection
in bright parts of the Galactic plane, especially near the Galactic center. For
scattered light received from low-mass cores with grain sizes beyond 0.5
$\mu$m, the directional characteristics of the scattering favors the detection
of scattered light above and below the Galactic center, and to some extent near
the Galactic anti-center. We identify the local incident radiation field as the
major unknown causing deviations from this simple scheme.


title:
Parton energy loss in high energy hard forward processes in
  proton-nucleus collisions

abstract:
  We calculate the spectrum of energy loss differences due to gluon radiation
in high energy hard forward processes in proton-nucleus collisions as compared
to proton-proton collisions. We find that the nuclear induced energy loss
scales linearly with the beam energy. We evaluate the spectrum and "typical"
energy losses in a logarithmic and large $N_{c}$ approximation. The energy
losses found appear large enough to be phenomenologically important.


title:
Spectral Expansions of Homogeneous and Isotropic Tensor-Valued Random
  Fields

abstract:
  We establish spectral expansions of homogeneous and isotropic random fields
taking values in the $3$-dimensional Euclidean space $E^3$ and in the space
$\mathsf{S}^2(E^3)$ of symmetric rank $2$ tensors over $E^3$. The former is a
model of turbulent fluid velocity, while the latter is a model for the random
stress tensor or the random conductivity tensor. We found a link between the
theory of random fields and the theory of finite-dimensional convex compacta.


title:
Variable Selection and Estimation for Partially Linear Single-index
  Models with Longitudinal Data

abstract:
  In this paper, we consider the partially linear single-index models with
longitudinal data. To deal with the variable selection problem in this context,
we propose a penalized procedure combined with two bias correction methods,
resulting in the bias-corrected generalized estimating equation (GEE) and the
bias-corrected quadratic inference function (QIF), which can take into account
the correlations. Asymptotic properties of these methods are demonstrated. We
also evaluate the finite sample performance of the proposed methods via Monte
Carlo simulation studies and a real data analysis.


title:
A contactless microwave-based diagnostic tool for high repetition rate
  laser systems

abstract:
  We report on a novel electro-optic device for the diagnostics of high
repetition rate laser systems. It is composed of a microwave receiver and of a
second order nonlinear crystal, whose irradiation with a train of short laser
pulses produces a time-dependent polarization in the crystal itself as a
consequence of optical rectification. This process gives rise to the emission
of microwave radiation that is detected by a receiver and is analyzed to infer
the repetition rate and intensity of the pulses.
  We believe that this new method may overcome some of the limitations of
photodetection techniques.


title: Spherical functors on the Kummer surface

abstract:
  We find two natural spherical functors associated to the Kummer surface and
analyse how their induced twists fit with Bridgeland's conjecture on the
derived autoequivalence group of a complex algebraic K3 surface.