title: Two-Loop Master Integrals for $q \bar{q} \to V V$: the Planar Topologies

abstract:
  The two-loop QCD corrections to vector boson pair production at hadron
colliders involve a new class of Feynman integrals: two-loop four-point
functions with two off-shell external legs. We describe their reduction to a
small set of master integrals by solving linear relations among them. We then
use differential equations in the external invariants to compute all master
integrals that are relevant to planar Feynman amplitudes. Our results are
expressed analytically in terms of generalised harmonic polylogarithms. The
calculation relies heavily on techniques that exploit the algebraic structure
of these functions, which we describe in detail.


title: Local Temperature of Out-of-Equilibrium Quantum Electron Systems

abstract:
  We show how the local temperature of out-of-equilibrium, quantum electron
systems can be consistently defined with the help of an external voltage and
temperature probe. We determine sufficient conditions under which the
temperature measured by the probe (i) is independent of details of the
system-probe coupling, (ii) is equal to the temperature obtained from an
independent current-noise measurement, (iii) satisfies the transitivity
condition expressed by the zeroth law of thermodynamics, and (iv) is consistent
with Carnot's theorem. This local temperature therefore characterizes the
system in the common sense of equilibrium thermodynamics, but remains well
defined even in out-of-equilibrium situations with no local equilibrium.


title: Higgs Discovery: Impact on Composite Dynamics [Thinking Fast and Slow]

abstract:
  I discuss the impact of the discovery of a Higgs-like state on composite
dynamics starting by critically examining the reasons in favour of either an
elementary or composite nature of this state. Accepting the standard model
interpretation I re-address the standard model vacuum stability within a
Weyl-consistent computation.
  I will carefully examine the fundamental reasons why what has been discovered
might not be the standard model Higgs. Dynamical electroweak breaking naturally
addresses a number of the fundamental issues unsolved by the standard model
interpretation. However this paradigm has been challenged by the discovery of a
not-so-heavy Higgs-like state. I will therefore review the recent discovery
\cite{Foadi:2012bb} that the standard model top-induced radiative corrections
naturally reduce the intrinsic non-perturbative mass of the composite Higgs
state towards the desired experimental value. Not only we have a natural and
testable working framework but we have also suggested specific gauge theories
that can realise, at the fundamental level, these minimal models of dynamical
electroweak symmetry breaking. These strongly coupled gauge theories are now
being heavily investigated via first principle lattice simulations with
encouraging results.
  The new findings show that the recent naive claims made about new strong
dynamics at the electroweak scale being disfavoured by the discovery of a
not-so-heavy composite Higgs are unwarranted.
  I will then introduce the more speculative idea of extreme compositeness
according to which not only the Higgs sector of the standard model is composite
but also quarks and leptons, and provide a toy example in the form of
gauge-gauge duality.


title: From Alternating Sign Matrices to the Gaussian Unitary Ensemble

abstract:
  The aim of this note is to prove that fluctuations of uniformly random
alternating sign matrices (equivalently, configurations of the six-vertex model
with domain wall boundary conditions) near the boundary are described by the
Gaussian Unitary Ensemble and the GUE-corners process.


title: Cross helicity and related dynamo

abstract:
  The turbulent cross helicity is directly related to the coupling coefficients
for the mean vorticity in the electromotive force and for the mean
magnetic-field strain in the Reynolds stress tensor. This suggests that the
cross-helicity effects are important in the cases where global inhomogeneous
flow and magnetic-field structures are present. Since such large-scale
structures are ubiquitous in geo/astrophysical phenomena, the cross-helicity
effect is expected to play an important role in geo/astrophysical flows. In the
presence of turbulent cross helicity, the mean vortical motion contributes to
the turbulent electromotive force. Magnetic-field generation due to this effect
is called the cross-helicity dynamo. Several features of the cross-helicity
dynamo are introduced. Unlike the case in the helicity or $\alpha$ effect,
where ${\bf{J}}$ is aligned with ${\bf{B}}$ in the turbulent electromotive
force, we in general have a finite mean-field Lorentz force ${\bf{J}} \times
{\bf{B}}$ in the cross-helicity dynamo. This gives a distinguished feature of
the cross-helicity effect. By considering the effects of cross helicity in the
momentum equation, we see several interesting consequences of the effect.
Turbulent cross helicity coupled with the mean magnetic shear reduces the
effect of turbulent or eddy viscosity. Flow induction is an important
consequence of this effect. One key issue in the cross-helicity dynamo is to
examine how and how much cross helicity can be present in turbulence. On the
basis of the cross-helicity transport equation, its production mechanisms are
discussed. Some recent developments in numerical validation of the basic notion
of the cross-helicity dynamo are also presented.


title: Clipping the Cosmos II: Cosmological information from non-linear scales

abstract:
  We present a method for suppressing contributions from higher-order terms in
perturbation theory, greatly increasing the amount of information which may be
extracted from the matter power spectrum. In an evolved cosmological density
field the highest density regions are responsible for the bulk of the nonlinear
power. By suitably down-weighting these problematic regions we find that the
one- and two-loop terms are typically reduced in amplitude by ~70 per cent and
~95 per cent respectively, relative to the linear power spectrum. This greatly
facilitates modelling the shape of the galaxy power spectrum, potentially
increasing the number of useful Fourier modes by more than two orders of
magnitude. We provide a demonstration of how this technique allows the galaxy
bias and the amplitude of linear matter perturbations sigma_8 to be determined
from the power spectrum on conventionally nonlinear scales, 0.1<k<0.7 h/Mpc.


title:
Are there missing bond paths in Trimethylenemethane-Iron-tri-carbonyl
  [(CO)3Fe-(C4H6)] complex?

abstract:
  In a recent paper [J. Organomet. Chem. (2013) doi: 10.1016 /j.jorganchem.
2013.03.047] analyzing the bonding mode of Trimethylenemethane (TMM) with some
metal carbonyls, Mousavi and Frenking have declared the absence of bond paths,
the so-called missed bond paths, between metal atoms and terminal carbon atoms
in several complexes. In this communication, it is first demonstrated that the
presupposition of the equivalence of a bond path and a chemical bond within the
context of the quantum theory of atoms in molecules (QTAIM) is superficial and
basically flawed which is not only against with the recent strict declaration
on the contrary [R.F.W. Bader, J. Phys. Chem. A 113 (2009) 10396], but also in
odd with the foundations of the QTAIM. Then, it is demonstrated that the
so-called missed bond paths indeed appear in molecular graphs of some
non-equilibrium geometries that are energetically quite accessible at room
temperatures. To emphasize on the importance of this observation the term
passionate neighbors is coined referring to the atomic basins that do not share
an inter-atomic surface at the equilibrium geometry but are neighbors, share an
inter-atomic surface, at non-equilibrium geometries accessible by nuclear
vibrations. Using the delocalization index as well as other evidence from
previous literature it is demonstrated that the QTAIM analysis is indeed
compatible with the presence of chemical bonds between iron metal and terminal
carbons in (CO)3Fe-TMM complex. Finally, some general discussions are done to
unravel the delicate relationship between the QTAIM proposed concepts, e.g.
bond paths and molecular graphs, and some orthodox concepts of chemistry, e.g.
chemical bonds and chemical structures, emphasizing that there is no one-to-one
relationship between these two categorizes.


title:
The Monitor Project: Stellar rotation at 13~Myr: I. A photometric
  monitoring survey of the young open cluster h~Per

abstract:
  We aim at constraining the angular momentum evolution of low mass stars by
measuring their rotation rates when they begin to evolve freely towards the
ZAMS, i.e. after the disk accretion phase has stopped. We conducted a
multi-site photometric monitoring of the young open cluster h Persei that has
an age of ~13 Myr. The observations were done in the I-band using 4 different
telescopes and the variability study is sensitive to periods from less than 0.2
day to 20 days. Rotation periods are derived for 586 candidate cluster members
over the mass range 0.4<=M/Msun<=1.4. The rotation period distribution
indicates a sligthly higher fraction of fast rotators for the lower mass
objects, although the lower and upper envelopes of the rotation period
distribution, located respectively at ~0.2-0.3d and ~10d, are remarkably flat
over the whole mass range. We combine this period distribution with previous
results obtained in younger and older clusters to model the angular momentum
evolution of low mass stars during the PMS. The h Per cluster provides the
first statistically robust estimate of the rotational period distribution of
solar-type and lower mass stars at the end of the PMS accretion phase (>10
Myr). The results are consistent with models that assume significant
core-envelope decoupling during the angular momentum evolution to the ZAMS.


title:
The International Linear Collider Technical Design Report - Volume 2:
  Physics

abstract:
  The International Linear Collider Technical Design Report (TDR) describes in
four volumes the physics case and the design of a 500 GeV centre-of-mass energy
linear electron-positron collider based on superconducting radio-frequency
technology using Niobium cavities as the accelerating structures. The
accelerator can be extended to 1 TeV and also run as a Higgs factory at around
250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator
is give, together with associated uncertainties. It is shown that no
significant technical issues remain to be solved. Once a site is selected and
the necessary site-dependent engineering is carried out, construction can begin
immediately. The TDR also gives baseline documentation for two high-performance
detectors that can share the ILC luminosity by being moved into and out of the
beam line in a "push-pull" configuration. These detectors, ILD and SiD, are
described in detail. They form the basis for a world-class experimental
programme that promises to increase significantly our understanding of the
fundamental processes that govern the evolution of the Universe.


title:
The International Linear Collider Technical Design Report - Volume 3.I:
  Accelerator R&D in the Technical Design Phase


title: Induced Electroweak Symmetry Breaking and Supersymmetric Naturalness

abstract:
  In this paper we study a new class of supersymmetric models that can explain
a 125 GeV Higgs without fine-tuning. These models contain additional `auxiliary
Higgs' fields with large tree-level quartic interaction terms but no Yukawa
couplings. These have electroweak-breaking vacuum expectation values, and
contribute to the VEVs of the MSSM Higgs fields either through an induced
quartic or through an induced tadpole. The quartic interactions for the
auxiliary Higgs fields can arise from either D-terms or F-terms. The tadpole
mechanism has been previously studied in strongly-coupled models with large
D-terms, referred to as `superconformal technicolor.' The perturbative models
studied here preserve gauge coupling unification in the simplest possible way,
namely that all new fields are in complete SU(5) multiplets. The models are
consistent with the observed properties of the 125 GeV Higgs-like boson as well
as precision electroweak constraints, and predict a rich phenomenology of new
Higgs states at the weak scale. The tuning is less than 10% in almost all of
the phenomenologically allowed parameter space. If electroweak symmetry is
broken by an induced tadpole, the cubic and quartic Higgs self-couplings are
significantly smaller than in the standard model.


title: The Lusin theorem and horizontal graphs in the Heisenberg group

abstract:
  In this paper we prove that every collection of measurable functions
$f_\alpha$, $|\alpha|=m$ coincides a.e. with $m$th order derivatives of a
function $g\in C^{m-1}$ whose derivatives of order $m-1$ may have any modulus
of continuity weaker than that of a Lipschitz function. This is a stronger
version of earlier results of Lusin, Moonens-Pfeffer and Francos. As an
application we construct surfaces in the Heisenberg group with tangent spaces
being horizontal a.e.


title: Mechanical spin control of nitrogen-vacancy centers in diamond

abstract:
  As spin-based quantum technology evolves, the ability to manipulate spin with
non-magnetic fields is critical - both for the development of hybrid quantum
systems and for compatibility with conventional technology. Particularly useful
examples are electric fields, optical fields, and mechanical lattice
vibrations. The last of these represents direct spin-phonon coupling, which has
garnered fundamental interest as a potential mediator of spin-spin
interactions, but could also find applications in high-stability inertial
sensing. In this Letter, we demonstrate direct coupling between phonons and
nitrogen-vacancy (NV) center spins in diamond by inducing spin transitions with
mechanically-driven harmonic strain. The ability to control NV spins
mechanically can enhance NV-based quantum metrology, grant access to all
transitions within the spin-1 quantum state of the NV center, and provide a
platform to study spin-phonon interactions at the level of a few interacting
spins.


title: Exploring the complex world of two-dimensional ordering with three modes

abstract:
  The world of two-dimensional crystals is of great significance for the design
and study of structural and functional materials with novel properties. The
world of two-dimensional crystals is of great significance for the design and
study of structural and functional materials with novel properties. Here we
examine the mechanisms governing the formation and dynamics of these
crystalline or polycrystalline states and their elastic and plastic properties
by constructing a generic multi-mode phase field crystal model. Our results
demonstrate that a system with three competing length scales can order into all
five Bravais lattices, and other more complex structures including honeycomb,
kagome and other hybrid phases. In addition, non-equilibrium phase transitions
are examined to illustrate the complex phase behavior described by the model.
This model provides a systematic path to predict the influence of lattice
symmetry on both structure and dynamics of crystalline and defected systems.


title:
Maximal potentials, maximal singular integrals, and the spherical
  maximal function

abstract:
  We introduce a notion of maximal potentials and we prove that they form
bounded operators from $L^p$ to the homogeneous Sobolev space $\dot{W}^{1,p}$
for all $n/(n-1)<p<n$. We apply this result to the problem of boundedness of
the spherical maximal operator in Sobolev spaces.


title:
Quantum synchronization of quantum van der Pol oscillators with trapped
  ions

abstract:
  Van der Pol oscillators are prototypical self-sustaining oscillators which
have been used to model nonlinear processes in biological and other classical
processes. In this work, we investigate how quantum fluctuations affect
phase-locking in one or many van der Pol oscillators. We find that
phase-locking is much more robust in the quantum model than in the equivalent
classical model. Trapped-ion experiments are ideally suited to simulate van der
Pol oscillators in the quantum regime via sideband heating and cooling of
motional modes. We provide realistic experimental parameters for
${}^{171}\text{Yb}^+$ achievable with current technology.


title:
Particle-particle and quasiparticle random phase approximations:
  Connections to coupled cluster theory

abstract:
  We establish a formal connection between the particle-particle (pp) random
phase approximation (RPA) and the ladder channel of the coupled cluster doubles
(CCD) equations. The relationship between RPA and CCD is best understood within
a Bogoliubov quasiparticle (qp) RPA formalism. This work is a follow-up to our
previous formal proof on the connection between particle-hole (ph) RPA and
ring-CCD. Whereas RPA is a quasibosonic approximation, CC theory is a correct
bosonization in the sense that the wavefunction and Hilbert space are exactly
fermionic. Coupled cluster theory achieves this goal by interacting the ph
(ring) and pp (ladder) diagrams via a third channel that we here call
"crossed-ring" whose presence allows for full fermionic antisymmetry.
Additionally, coupled cluster incorporates what we call "mosaic" terms which
can be absorbed into defining a new effective one-body Hamiltonian. The
inclusion of these mosaic terms seems to be quite important. The pp-RPA an d
qp-RPA equations are textbook material in nuclear structure physics but are
largely unknown in quantum chemistry, where particle number fluctuations and
Bogoliubov determinants are rarely used. We believe that the ideas and
connections discussed in this paper may help design improved ways of
incorporating RPA correlation into density functionals based on a CC
perspective.


title: Fractional Maps as Maps with Power-Law Memory

abstract:
  The study of systems with memory requires methods which are different from
the methods used in regular dynamics. Systems with power-law memory in many
cases can be described by fractional differential equations, which are
integro-differential equations. To study the general properties of nonlinear
fractional dynamical systems we use fractional maps, which are discrete
nonlinear systems with power-law memory derived from fractional differential
equations. To study fractional maps we use the notion of $\alpha$-families of
maps depending on a single parameter $\alpha > 0$ which is the order of the
fractional derivative in a nonlinear fractional differential equation
describing a system experiencing periodic kicks. $\alpha$-families of maps
represent a very general form of multi-dimensional nonlinear maps with
power-law memory, in which the weight of the previous state at time $t_i$ in
defining the present state at time $t$ is proportional to
$(t-{t_i})^{\alpha-1}$. They may be applicable to studying some systems with
memory such as viscoelastic materials, electromagnetic fields in dielectric
media, Hamiltonian systems, adaptation in biological systems, human memory,
etc. Using the fractional logistic and standard $\alpha$-families of maps as
examples we demonstrate that the phase space of nonlinear fractional dynamical
systems may contain periodic sinks, attracting slow diverging trajectories,
attracting accelerator mode trajectories, chaotic attractors, and cascade of
bifurcations type trajectories %with some new properties. whose properties are
different from properties of attractors in regular dynamical systems.


title: Zeros of L-functions outside the critical strip

abstract:
  For a wide class of Dirichlet series associated to automorphic forms, we show
that those without Euler products must have zeros within the region of absolute
convergence. For instance, we prove that if f is a classical holomorphic
modular form whose L-function does not vanish for Re(s) > (k+1)/2, then f is a
Hecke eigenform. Our proof adapts and extends work of Saias and Weingartner,
who proved a similar result for degree 1 L-functions.


title:
Spin dynamics in p-doped semiconductor nanostructures subject to a
  magnetic field tilted from the Voigt geometry

abstract:
  We develop a theoretical description of the spin dynamics of resident holes
in a p-doped semiconductor quantum well (QW) subject to a magnetic field tilted
from the Voigt geometry. We find the expressions for the signals measured in
time-resolved Faraday rotation (TRFR) and resonant spin amplification (RSA)
experiments and study their behavior for a range of system parameters. We find
that an inversion of the RSA peaks can occur for long hole spin dephasing times
and tilted magnetic fields. We verify the validity of our theoretical findings
by performing a series of TRFR and RSA experiments on a p-modulation doped
GaAs/Al_{0.3}Ga_{0.7}As single QW and showing that our model can reproduce
experimentally observed signals.


title:
Comments on the report "Indications of anomalous heat energy production
  in a reactor device containing hydrogen loaded nickel powder"
  [arXiv:1305.3913] by G.Levi, E.Foschi, T.Hartman, B.H\"oistad, R.Pettersson,
  L.Tegn\'er, H.Ess\'en

abstract:
  In a recent report titled "Indications of anomalous heat energy production in
a reactor device containing hydrogen loaded nickel powder" and published on
arXiv, G. Levi and co-workers put forth several claims concerning the
operations and performance of the so-called E-Cat of inventor Andrea Rossi. We
note first of all that the circumstances and people involved in the test make
it far from being an independent one. We examine the claims put forth by the
authors and note that in many cases they are not supported by the facts given
in the report. We present results from thermal calculations showing that
alternative explanations are possible were the authors seem to jump to
conclusions fitting pre-conceived ideas. In general we find that much attention
is drawn to trivialities, while important pieces of information and
investigation are lacking and seem not to have been conducted or considered. We
also note that the proposed claims would require new physics in not only one
but several areas. Besides a cold-fusion like process without production of any
radiation also extreme new material properties would be needed to explain what
rather seems to be a problem of correct measurement. Therefore, it is clear to
us that a truly independent and scientific investigation of the so called E-Cat
device, convincingly demonstrating an "anomalous heat energy production" has
not been presented in the arXiv report and is thus, to-date, still lacking.


title: Minding's Theorem for Low Degrees of Differentiability

abstract:
  We prove Minding's Theorem for $C^2$-immersions with constant negative Gauss
curvature. As a Corollary we also prove Minding's Theorem for
$C^{1M}$-immersions in the sense of \cite{DS}.


title: A simple construction of integrable Whitham type hierarchies

abstract:
  A simple construction of Whitham type hierarchies in all genera is suggested.
Potentials of these hierarchies are written as integrals of hypergeometric
type. Possible generalization for universal moduli space is also briefly
discussed.


title:
On Legendrian foliations in contact manifold I: Singularities and
  neighborhood theorems

abstract:
  In this note we study several aspects of coisotropic submanifolds of a
contact manifold. In particular we give a structure theorem for the singularity
of the characteristic foliation of a coisotropic submanifold. Moreover we
establish the existence and uniqueness results of germs of contact structures
near Legendrian foliations, which is a special case of coisotropic submanifold.
This note can be thought of as an attempt to generalize the study of surfaces
in three-dimensional contact geometry to higher dimensions.


title:
Morphology transition at depinning in a solvable model of interface
  growth in a random medium

abstract:
  We propose a simple, exactly solvable, model of interface growth in a random
medium that is a variant of the zero-temperature random-field Ising model on
the Cayley tree. This model is shown to have a phase diagram (critical
depinning field versus disorder strength) qualitatively similar to that
obtained numerically on the cubic lattice. We then introduce a specifically
tailored random graph that allows an exact asymptotic analysis of the height
and width of the interface. We characterize the change of morphology of the
interface as a function of the disorder strength, a change that is found to
take place at a multicritical point along the depinning-transition line.


title: Groups with some arithmetic conditions on real class sizes

abstract:
  Let G be a finite group. An element x in G is a real element if x is
conjugate to its inverse in G. For x in G, the conjugacy class x^G is said to
be a real conjugacy class if every element of x^G is real. We show that if 4
divides no real conjugacy class size of a finite group G, then G is solvable.
We also study the structure of such groups in detail. This generalizes several
results in the literature.


title: Social Ranking Techniques for the Web

abstract:
  The proliferation of social media has the potential for changing the
structure and organization of the web. In the past, scientists have looked at
the web as a large connected component to understand how the topology of
hyperlinks correlates with the quality of information contained in the page and
they proposed techniques to rank information contained in web pages. We argue
that information from web pages and network data on social relationships can be
combined to create a personalized and socially connected web. In this paper, we
look at the web as a composition of two networks, one consisting of information
in web pages and the other of personal data shared on social media web sites.
Together, they allow us to analyze how social media tunnels the flow of
information from person to person and how to use the structure of the social
network to rank, deliver, and organize information specifically for each
individual user. We validate our social ranking concepts through a ranking
experiment conducted on web pages that users shared on Google Buzz and Twitter.


title: Bernard Yarnton Mills 1920-2011

abstract:
  Bernie Mills is remembered globally as an influential pioneer in the evolving
field of radio astronomy. His contributions with the 'Mills Cross' at the CSIRO
Division of Radiophysics and later at the University of Sydney's School of
Physics and the development of the Molonglo Observatory Synthesis Telescope
(MOST) were widely recognised as astronomy evolved in the years 1948-1985 and
radio astronomy changed the viewpoint of the astronomer as a host of new
objects were discovered.


title:
Linearizing neutrino evolution equations including neutrino-antineutrino
  pairing correlations

abstract:
  We linearize the neutrino mean-field evolution equations describing the
neutrino propagation in a background of matter and of neutrinos, using
techniques from many-body microscopic approaches. The procedure leads to an
eigenvalue equation that allows to identify instabilities in the evolution,
associated with a change of the curvature of the neutrino energy-density
surface. Our result includes all contributions from the neutrino Hamiltonian
and is generalizable to linearize the equations of motion at an arbitrary point
of the evolution. We then consider the extended equations that comprise the
normal mean field as well as the abnormal mean field that is associated with
neutrino-antineutrino pairing correlations. We first re-derive the extended
neutrino Hamiltonian and show that such a Hamiltonian can be diagonalized by
introducing a generalized Bogoliubov-Valatin transformation with quasi-particle
operators that mix neutrinos and antineutrinos. We give the eigenvalue
equations that determine the energies of the quasi-particles eigenstates.
Finally we derive the eigenvalue equation of the extended equations of motion,
valid in the small amplitude approximation. Our results apply to an arbitrary
number of neutrino families.


title: Strong noise sensitivity and random graphs

abstract:
  The noise sensitivity of a Boolean function describes its likelihood to flip
under small perturbations of its input. Introduced in the seminal work of
Benjamini, Kalai and Schramm [Inst. Hautes \'{E}tudes Sci. Publ. Math. 90
(1999) 5-43], it was there shown to be governed by the first level of Fourier
coefficients in the central case of monotone functions at a constant critical
probability $p_c$. Here we study noise sensitivity and a natural stronger
version of it, addressing the effect of noise given a specific witness in the
original input. Our main context is the Erd\H{o}s-R\'{e}nyi random graph, where
already the property of containing a given graph is sufficiently rich to
separate these notions. In particular, our analysis implies (strong) noise
sensitivity in settings where the BKS criterion involving the first Fourier
level does not apply, for example, when $p_c\to0$ polynomially fast in the
number of variables.


title:
Comments on "An Update of the HLS Estimate of the Muon g-2"by M.Benayoun
  {\it et al.}, arXiv:1210.7184v3

abstract:
  In a recent paper \cite{benayoun} M.Benayoun {\it et al.} use a specific
model to compare results on the existing data for the cross section of the
process $e^+e^-\rightarrow \pi^+\pi^-$ and state conclusions about the
inconsistency of the BABAR results with those from the other experiments. We
show that a direct model-independent comparison of the data at hand contradicts
this claim. Clear discrepancies with the results of Ref. \cite{benayoun} are
pointed out. As a consequence we do not believe that the lower value and the
smaller uncertainty obtained for the prediction of the muon magnetic anomaly
are reliable results.


title: Metaheuristics in Flood Disaster Management and Risk Assessment

abstract:
  A conceptual area is divided into units or barangays, each was allowed to
evolve under a physical constraint. A risk assessment method was then used to
identify the flood risk in each community using the following risk factors: the
area's urbanized area ratio, literacy rate, mortality rate, poverty incidence,
radio/TV penetration, and state of structural and non-structural measures.
Vulnerability is defined as a weighted-sum of these components. A penalty was
imposed for reduced vulnerability. Optimization comparison was done with
MatLab's Genetic Algorithms and Simulated Annealing; results showed 'extreme'
solutions and realistic designs, for simulated annealing and genetic algorithm,
respectively.


title: Gaming the Attention Economy

abstract:
  The future of human computation (HC) benefits from examining tasks that
agents already perform and designing environments to give those tasks
computational significance. We call this natural human computation (NHC). We
consider the possible future of NHC through the lens of Swarm!, an application
under development for Google Glass. Swarm! motivates users to compute the
solutions to a class of economic optimization problems by engaging the
attention dynamics of crowds. We argue that anticipating and managing economies
of attention provides one of the most tantalizing future applications for NHC.


title: Effective interaction in an unbalanced Fermion mixture

abstract:
  A one dimensional Fermi mixture with delta--interaction is investigated in
the limit of extreme imbalance. In particular we consider the cases of only one
or two minority Fermions which interact with the Fermi-sea of the majority
Fermions. We calculate dispersion relation and polaron mass for the minority
Fermions as well as equal time density-density correlators. Within a cluster
expansion we derive an expression for the effective interaction potential
between minority Fermions. For our calculations we use a reformulation of the
exact wave functions, originally obtained by Yang and Gaudin by a nested Bethe
ansatz, in terms of determinants.


title:
Robust Reduced-Rank Adaptive Processing Based on Parallel Subgradient
  Projection and Krylov Subspace Techniques

abstract:
  In this paper, we propose a novel reduced-rank adaptive filtering algorithm
by blending the idea of the Krylov subspace methods with the set-theoretic
adaptive filtering framework. Unlike the existing Krylov-subspace-based
reduced-rank methods, the proposed algorithm tracks the optimal point in the
sense of minimizing the \sinq{true} mean square error (MSE) in the Krylov
subspace, even when the estimated statistics become erroneous (e.g., due to
sudden changes of environments). Therefore, compared with those existing
methods, the proposed algorithm is more suited to adaptive filtering
applications. The algorithm is analyzed based on a modified version of the
adaptive projected subgradient method (APSM). Numerical examples demonstrate
that the proposed algorithm enjoys better tracking performance than the
existing methods for the interference suppression problem in code-division
multiple-access (CDMA) systems as well as for simple system identification
problems.


title: Near-Infrared Imaging Polarimetry of HD142527

abstract:
  HD 142527 is a pre-transition disk with strong evidence for on-going planet
formation. Recent observations show a disrupted disk with spiral arms, a
dust-depleted inner cavity and the possible presence of gas streams driving gas
from the outer disk towards the central star. We aim to derive the morphology
of the disk, as well as the distribution and properties of the dust at its
surface. We have obtained polarized differential images of HD 142527 at $H$ and
$Ks$ bands with NaCo at the VLT. Combining these images with classical
PSF-subtraction, we are able to derive the polarization degree of this disk. At
$H$ band the polarization degree of the disk varies between 10% and 25%. This
result cannot be reproduced by dust distributions containing highly porous
material. The polarization is better matched by distributions of compact
particles, with maximum sizes at least up to a few microns, in agreement with
previous observations. We also observe two regions of low emission (nulls) in
total and in polarized intensity. In particular, one of these nulls is at
roughly the same position as the maximum of the horse-shoe shape observed in
sub-millimeter continuum emission ALMA Band-7 (345 GHz) observations. We
discuss the possible link between both features.


title: Quantum tunneling from three-dimensional black holes

abstract:
  We study Hawking radiation from three-dimensional black holes. For this
purpose the emission of charged scalar and charged fermionic particles is
investigated from charged BTZ black holes, with and without rotation. We use
the quantum tunneling approach incorporating WKB approximation and spacetime
symmetries. Another class of black hole which is asymptotic to a Sol
three-manifold has also been investigated. This procedure gives us the
tunneling probability of outgoing particles, and we compute the temperature of
the radiation for these black holes. We also consider the quantum tunneling of
particles from black hole asymptotic to Sol geometry.


title: Comment on Ashtekar: Generalization of Wigner's Principle

abstract:
  Ashtekar (2013) has illustrated that two of the available roads to testing
for time asymmetry can be generalized beyond the structure of quantum theory,
to much more general formulations of mechanics. The purpose of this note is to
show that a third road to T-violation, which I have called "Wigner's
Principle," can be generalized in this way as well.


title: Three Merry Roads to T-Violation

abstract:
  This paper is a tour of how the laws of nature can distinguish between the
past and the future, or be T-violating. I argue that, in terms of the basic
argumentative structure, there are really just three approaches currently being
explored. I show how each is characterized by a symmetry principle, which
provides a template for detecting T-violating laws even without knowing the
laws of physics themselves. Each approach is illustrated with an example, and
the prospects of each are considered in extensions of particle physics beyond
the standard model.


title:
The MOG weak field approximation and observational test of galaxy
  rotation curves

abstract:
  As an alternative to dark matter models, MOdified Gravity (MOG) theory can
compensate for dark matter by a covariant modification of Einstein gravity. The
theory introduces two additional scalar fields and one vector field. The aim is
to explain the dynamics of astronomical systems based only on their baryonic
matter. The effect of the vector field in the theory resembles a Lorentz force
where each mass has a charge proportional to the inertial mass. In this work,
we obtain the weak field approximation of MOG by perturbing the metric and the
fields around Minkowski space-time. We derive an effective gravitational
potential which yields the Newtonian attractive force plus a repulsive Yukawa
force. This potential, in addition to the Newtonian gravitational constant,
$G_N$, has two additional constant parameters $\alpha$ and $\mu$. We use the
THINGS catalog of galaxies and fix the two parameters $\alpha$ and $\mu$ of the
theory to be $\alpha =8.89 \pm 0.34$ and $\mu =0.04 \pm 0.004 {\rm kpc}^{-1}$.
We then apply the effective potential with the fixed universal parameters to
the Ursa-Major catalog of galaxies and obtain good fits to galaxy rotation
curve data with an average value of $\bar{\chi^2} = 1.07 $. In the fitting
process, only the stellar mass-to-light ratio $(M/L)$ of the galaxies is a free
parameter. As predictions of MOG, our derived $M/L$ is shown to be correlated
with the color of galaxies, and we fit the Tully-Fisher relation for galaxies.
As an alternative to dark matter, introducing an effective weak field potential
for MOG opens a new window to the astrophysical applications of the theory.


title:
Physical properties, transmission and emission spectra of the WASP-19
  planetary system from multi-colour photometry

abstract:
  We present new ground-based, multi-colour, broad-band photometric
measurements of the physical parameters, transmission and emission spectra of
the transiting extrasolar planet WASP-19b. The measurements are based on
observations of 8 transits and four occultations using the 1.5m Danish
Telescope, 14 transits at the PEST observatory, and 1 transit observed
simultaneously through four optical and three near-infrared filters, using the
GROND instrument on the ESO 2.2m telescope. We use these new data to measure
refined physical parameters for the system. We find the planet to be more
bloated and the system to be twice as old as initially thought. We also used
published and archived datasets to study the transit timings, which do not
depart from a linear ephemeris. We detected an anomaly in the GROND transit
light curve which is compatible with a spot on the photosphere of the parent
star. The starspot position, size, spot contrast and temperature were
established. Using our new and published measurements, we assembled the
planet's transmission spectrum over the 370-2350 nm wavelength range and its
emission spectrum over the 750-8000 nm range. By comparing these data to
theoretical models we investigated the theoretically-predicted variation of the
apparent radius of WASP-19b as a function of wavelength and studied the
composition and thermal structure of its atmosphere. We conclude that: there is
no evidence for strong optical absorbers at low pressure, supporting the common
idea that the planet's atmosphere lacks a dayside inversion; the temperature of
the planet is not homogenized, because the high warming of its dayside causes
the planet to be more efficient in re-radiating than redistributing energy to
the night side; the planet seems to be outside of any current classification
scheme.


title: Nonnegative solutions to stochastic heat equation with nonlinear drift

abstract:
  We consider one-dimensional stochastic heat equation with nonlinear drift,
$\displaystyle \partial_t u=\frac{1}{2}\Delta u+b(u)u+\sigma(u)\dot{W}(t,x)$,
where $b:\mathbb{R}_{+}\to \mathbb{R}$ is a continuous function and
$\sigma:\mathbb{R}_{+}\to \mathbb{R}$ is a continuous function with suitable
property. We will construct nonnegative solutions to such SPDEs.


title: An invariance principle for Brownian motion in random scenery

abstract:
  We prove an invariance principle for Brownian motion in Gaussian or
Poissonian random scenery by the method of characteristic functions. Annealed
asymptotic limits are derived in all dimensions, with a focus on the case of
dimension $d=2$, which is the main new contribution of the paper.


title:
Geometric phase effects in dynamics near conical intersections: Symmetry
  breaking and spatial localization

abstract:
  We show that finite systems with conical intersections can exhibit
spontaneous symmetry breaking which manifests itself in spatial localization of
eigenstates. This localization has a geometric phase origin and is robust
against variation of model parameters. The transition between localized and
delocalized eigenstate regimes resembles a continuous phase transition. The
localization slows down the low-energy quantum nuclear dynamics at zero and low
temperatures.


title: The Diffusion Approximation in Turbulent Two-Particle Dispersion

abstract:
  We solve an inverse problem for fluid particle pair-statistics: we show that
a time sequence of probability density functions (PDF's) of separations can be
exactly reproduced by solving the diffusion equation with a suitable
time-dependent diffusivity. The diffusivity tensor is given by a time-integral
of a conditional Lagrangian velocity structure-function, weighted by a ratio of
PDF's. Physical hypotheses for hydrodynamic turbulence (sweeping, short memory,
mean-field) yield simpler integral formulas, including one of Kraichnan and
Lundgren. We evaluate the latter using a spacetime database from a numerical
Navier-Stokes solution for driven turbulence. This diffusion theory reproduces
PDF's well at rms separations, but growth rate of mean-square dispersion is
overpredicted due to neglect of memory effects. More general applications of
our approach are sketched.


title: Hard hexagon partition function for complex fugacity

abstract:
  We study the analyticity of the partition function of the hard hexagon model
in the complex fugacity plane by computing zeros and transfer matrix
eigenvalues for large finite size systems. We find that the partition function
per site computed by Baxter in the thermodynamic limit for positive real values
of the fugacity is not sufficient to describe the analyticity in the full
complex fugacity plane. We also obtain a new algebraic equation for the low
density partition function per site.


title: Construction of class fields over imaginary biquadratic fields

abstract:
  Let $K$ be an imaginary biquadratic field and $K_1$, $K_2$ be its imaginary
quadratic subfields. For integers $N>0$, $\mu\geq 0$ and an odd prime $p$ with
$\gcd(N,p)=1$, let $K_{(Np^\mu)}$ and $(K_i)_{(Np^\mu)}$ for $i=1,2$ be the ray
class fields of $K$ and $K_i$, respectively, modulo $Np^\mu$. We first present
certain class fields $\widetilde{K_{N,p,\mu}^{1,2}}$ of $K$, in the sense of
Hilbert, which are generated by Siegel-Ramachandra invariants of
$(K_i)_{(Np^{\mu+1})}$ for $i=1,2$ over $K_{(Np^\mu)}$ and show that
$K_{(Np^{\mu+1})}=\widetilde{K_{N,p,\mu}^{1,2}}$ for almost all $\mu$.


title: The $C^{1+\alpha}$ hypothesis in Pesin theory revisited

abstract:
  We show that for every compact 3-manifold $M$ there exists an open subset of
$\diff ^1(M)$ in which every generic diffeomorphism admits uncountably many
ergodic probability measures which are hyperbolic while their supports are
disjoint and admit a basis of attracting neighborhoods and a basis of repelling
neighborhoods. As a consequence, the points in the support of these measures
have no stable and no unstable manifolds. This contrasts with the higher
regularity case, where Pesin theory gives us the stable and the unstable
manifolds with complementary dimensions at almost every point. We also give
such an example in dimension two, without local genericity.


title: The Plancherel Formula for Minimal Parabolic Subgroups

abstract:
  In a recent paper we found conditions for a nilpotent Lie group to be
foliated into subgroups that have square integrable unitary representations
that fit together to form a filtration by normal subgroups. That resulted in
explicit character formulae, Plancherel formulae and multiplicity formulae. We
also showed that nilradicals $N$ of minimal parabolic subgroups $P = MAN$ enjoy
that "stepwise square integrable" property. Here we extend those results from
$N$ to $P$. The Pfaffian polynomials, which give orthogonality relations and
Plancherel density for $N$, also give a semiinvariant differential operator
that compensates lack of unimodularity for $P$. The result is a completely
explicit Plancherel formula for $P$.


title: Layered compounds AFBiS2: superior birefringent crystals

abstract:
  Stimulated by the discovery of the giant birefringence (GBF) in LaOBiS2 (H.
Wang, arxiv: 1304.5032), we check SrFBiS2 and find a superior birefringence up
to 1.28. Naturally, AF layer (i.e., SrF) is considered to be of important and
is demonstrated by the further study on AFBiS2 (A=Mg, Ca, Ba). Interestingly,
MgFBiS2 shows the largest birefringence of 1.65. Furthermore, the origin of GBF
is discussed in detail.


title: Dilepton Production in Heavy-Ion Collisions

abstract:
  The properties of electromagnetic radiation from hot fireballs as created in
ultra-relativistic heavy-ion collisions are reviewed. We first outline how the
medium effects in the electromagnetic spectral function, which governs thermal
production rates, relate to the (partial) restoration of chiral symmetry. In
particular, we show how chiral and QCD sum rules, together with constraints
from lattice QCD, can render these relations quantitative. Turning to dilepton
data, we elaborate on updates in the space-time evolution and quark-gluon
plasma emission rates from lattice-QCD calculations. With a now available
excitation function in dilepton spectra from the RHIC beam-energy scan
connecting down to SPS energies, we argue that a consistent interpretation of
dilepton data emerges. Combining well-constrained space-time evolutions with
state-of-the-art emission rates identifies most of the radiation to emanate
from around the pseudo-critical temperature, and thus confirms resonance
melting as the prevalent mechanism in this regime, compatible with chiral
restoration. Recent measurements of a relatively soft slope and large elliptic
flow in direct-photon spectra at RHIC and LHC lend further support to this
picture.


title:
Evaluation of imaging protocol for ECT based on CS image reconstruction
  algorithm

abstract:
  SPECT (Single-photon Emission Computerized Tomography) and PET (Positron
Emission Tomography) are essential medical imaging tools, for which the
sampling angle number, scan time should be chosen carefully to compromise
between image quality and the radiopharmaceutical dose. In this study, the
image quality of different acquisition protocol was evaluated via varied angle
number and count number per angle with Monte Carlo simulation data. It was
shown that when similar imaging counts were used, the factor of acquisition
counts was more important than that of the sampling number in ECT (Emission
Computerized Tomography). To further reduce the activity requirement and the
scan duration, an iterative image reconstruction algorithm for limited-view and
low-dose tomography based on compressed sensing theory has been developed. The
total variation regulation was added in the reconstruction process to improve
SNR (Signal to Noise Ratio) and reduce the artifacts caused by the limited
angle sampling. Maximization of maximum likelihood of the estimated image and
the measured data and minimization of the total variation of the image are
alternative implemented. By using this advanced algorithm, the reconstruction
process is able to achieve image quality matching or exceeding that of normal
scan with only half of the injection radiopharmaceutical dose.


title: Charge transport by holographic Fermi surfaces

abstract:
  We compute the contribution to the conductivity from holographic Fermi
surfaces obtained from probe fermions in an AdS charged black hole. This
requires calculating a certain part of the one-loop correction to a vector
propagator on the charged black hole geometry. We find that the current
dissipation is as efficient as possible and the transport lifetime coincides
with the single-particle lifetime. In particular, in the case where the
spectral density is that of a marginal Fermi liquid, the resistivity is linear
in temperature.


title: Query Centric CPS (QCPS) Approach for Multiple Heterogeneous Systems

abstract:
  In modern scenario we need to have mechanisms which can provide better
interaction with physical world by an efficient and more effective
communication and computation approach for multiple heterogeneous sensor
networks. Previous work provides efficient communication approach between
sensor nodes and a query centric approach for multiple collaborative
heterogeneous sensor networks. Even there is energy issues involved in wireless
sensor network operation. In this paper we have proposed Query centric Cyber
Physical System (QCPS)model to implement query centric user request using Cyber
Physical System (CPS). CPS takes both communication and computation in parallel
to provide better interaction with physical world. This feature of CPS reduces
system cost and makes it more energy efficient. This paper provides an
efficient query processing approach for multiple heterogeneous sensor networks
using cyber physical system.This approach results in reduction of communication
and computation cost as sensor network communicates using centroid of
respective grids which reduces cost of communication while involvement of CPS
reduces the computation cost.


title:
Non-local approximation of continuous functions using scattered
  translates of the general multiquadric $(x^2+c^2)^{k-1/2}$

abstract:
  This article shows that on a closed interval $[a,b]$ a continuous function
may be approximated to an arbitrary degree of accuracy using scattered
translates of the general multiquadric $(x^2+c^2)^{k-1/2}$.


title:
A null space analysis of the L1 synthesis method in dictionary-based
  compressed sensing

abstract:
  An interesting topic in compressed sensing aims to recover signals with
sparse representations in a dictionary. Recently the performance of the
L1-analysis method has been a focus, while some fundamental problems for the
L1-synthesis method are still unsolved. For example, what are the conditions
for it to stably recover compressible signals under noise? Whether coherent
dictionaries allow the existence of sensing matrices that guarantee good
performances of the L1-synthesis method? To answer these questions, we build up
a framework for the L1-synthesis method. In particular, we propose a
dictionary-based null space property DNSP which, to the best of our knowledge,
is the first sufficient and necessary condition for the success of L1-synthesis
without measurement noise. With this new property, we show that when the
dictionary D is full spark, it cannot be too coherent otherwise the method
fails for all sensing matrices. We also prove that in the real case, DNSP is
equivalent to the stability of L1-synthesis under noise.


title:
Size-dependent intersubband optical properties of dome-shaped InAs/GaAs
  quantum dots with wetting layer

abstract:
  In this work, the effect of size and wetting layer on subband electronic
envelop functions, eigenenergies, linear and nonlinear absorption coefficients
and refractive indices of a dome-shaped InAs/GaAs quantum dot were
investigated. In our model, a dome of InAs quantum dot with its wetting layer
embedded in a GaAs matrix was considered. A finite height barrier potential at
the InAs/GaAs interface was assumed. To calculate envelop functions and
eigenenergies, the effective one electronic band Hamiltonian and electron
effective mass approximation were used. The linear and nonlinear optical
properties were calculated by the density matrix formalism.


title:
Screening the fifth force in the Horndeski's most general scalar-tensor
  theories

abstract:
  We study how the Vainshtein mechanism operates in the most general
scalar-tensor theories with second-order equations of motion. The field
equations of motion, which can be also applicable to most of other screening
scenarios proposed in literature, are generally derived in a spherically
symmetric space-time with a matter source. In the presence of a field coupling
to the Ricci scalar, we clarify conditions under which the Vainshtein mechanism
is at work in a weak gravitational background. We also obtain the solutions of
the field equation inside a spherically symmetric body and show how they can be
connected to exterior solutions that accommodate the Vainshtein mechanism. We
apply our general results to a number of concrete models such as the
covariant/extended Galileons and the DBI Galileons with Gauss-Bonnet and other
terms. In these models the fifth force can be suppressed to be compatible with
solar-system constraints, provided that non-linear field kinetic terms coupled
to the Einstein tensor do not dominate over other non-linear field
self-interactions.


title: On Modeling Economic Default Time: A Reduced-Form Model Approach

abstract:
  In the aftermath of the global financial crisis, much attention has been paid
to investigating the appropriateness of the current practice of default risk
modeling in banking, finance and insurance industries. A recent empirical study
by Guo et al.(2008) shows that the time difference between the economic and
recorded default dates has a significant impact on recovery rate estimates. Guo
et al.(2011) develop a theoretical structural firm asset value model for a firm
default process that embeds the distinction of these two default times. To be
more consistent with the practice, in this paper, we assume the market
participants cannot observe the firm asset value directly and developed a
reduced-form model to characterize the economic and recorded default times. We
derive the probability distribution of these two default times. The numerical
study on the difference between these two shows that our proposed model can
both capture the features and fit the empirical data.


title:
Thermal Hawking Broadening and Statistical Entropy of Black Hole Wave
  Packet

abstract:
  The quantum mechanical structure of Schwarzschild black hole is probed, in
the mini super spacetime, by means of a non-singular minimal uncertainty
Hartle-Hawking wave packet. The Compton width of the microstate probability
distribution is translated into a thermal Hawking broadening of the mass
spectrum. The statistical entropy is analytically calculated using the Fowler
prescription. While the exact Bekenstein-Hawking entropy is recovered at the
semi classical limit, the accompanying logarithmic tail gives rise to a Planck
size minimal entropy black wave packet.


title:
Beat the Rayleigh limit: OAM based super-resolution diffraction
  tomography

abstract:
  This letter is the first to report that a super-resolution imaging beyond the
Rayleigh limit can be achieved by using classical diffraction tomography (DT)
extended with orbital angular momentum (OAM), termed as OAM based diffraction
tomography (OAM-DT). It is well accepted that the orbital angular momentum
(OAM) provides additional electromagnetic degrees of freedom. This concept has
been widely applied in science and technology. In this letter we revisit the DT
problem extended with OAM, demonstrate theoretically and numerically that there
is no physical limits on imaging resolution in principle by the OAM-DT. This
super-resolution OAM-DT imaging paradigm, has no requirement for evanescent
fields, subtle focusing lens, complicated post-processing, etc., thus provides
a new approach to realize the wavefield imaging of universal objects with
sub-wavelength resolution.


title: Coulomb-oscillator origin of superconductivity in p-doped copper oxides

abstract:
  Emergence, development and cessation of superconductivity in three
representative compounds of copper oxide families---cation doped
Ca_2-xNa_xCuO2Cl2 and La_2-xAe_xCuO4 (Ae = Ba, Sr), as well as oxygen enriched
YBa2Cu3O_6+x ---are explained with the Coulomb-oscillator model of
superconductivity. By the model, non-resistive current is carried by axial
Coulomb oscillations of s electrons through neighbor nuclei---here excited 3s
electrons from O^2- ions through next-nearest neighbor oxygen nuclei---if their
accompanying lateral oscillation is sufficiently confined to prevent lateral
overswing. Cation doping gives rise to a superlattice in the layers that
sandwich each CuO2 plane. In Ca_2-xNa_xCuO2Cl2, having one CuO2 plane per unit
cell, superconductivity emerges when laterally confined Coulomb oscillators
start connecting along 6 x 6 superlattice domains (in units of planar lattice
constants) and it peaks at 4 x 4 domains when, at doping x = 1/8, the
superlattice is completed. With further doping a new, off-set superlattice
grows. Its frustrating effect gradually reduces superconductivity to cessation.
The same mechanism holds for La_2-xAe_xCuO4 which has two, staggered CuO2
planes per unit cell. The staggering causes superconducting frustration or
boost between adjacent layer sandwiches. This results in a double hump of the
transition temperature Tc(x), instead of a dome, with a deep furrow or dip at x
= 1/8 for Ae = Ba or Sr, respectively. Oxygen enrichment of YBa2Cu3O_6+x
indirectly leads to effective doping in the CuO2 planes themselves (Cu^2+ -->
Cu^3+). The ionization of copper ions at the corners of planar unit cells
determines whether lateral oscillations between next-nearest neighbor O^2- ions
overswing (Tc = 0) or are confined to wide or narrow electron tracks. Their
percolating connectivity gives rise to respective plateaus of Tc = 57 K and Tc
= 90 K, and intermediate ramps.


title:
Aristotle's Logic Computed by Parametric Probability and Linear
  Optimization

abstract:
  A new computational method is presented to implement the system of deductive
logic described by Aristotle in Prior Analytics. Each Aristotelian problem is
interpreted as a parametric probability network in which the premises give
constraints on probabilities relating the problem's categorical terms (major,
minor, and middle). Each probability expression from this network is evaluated
to yield a linear function of the parameters in the probability model. By this
approach the constraints specified as premises translate into linear equalities
and inequalities involving a few real-valued variables. The problem's figure
(schema) describes which specific probabilities are constrained, relative to
those that are queried. Using linear optimization methods, the minimum and
maximum feasible values of certain queried probabilities are computed, subject
to the constraints given as premises. These computed solutions determine
precisely which conclusions are necessary consequences of the premises. In this
way, Aristotle's logical deductions can be accomplished by means of numerical
computation.


title:
A Cross-correlation Analysis of AGN and Galaxies using Virtual
  Observatory: Dependence on Virial Mass of Super-Massive Black Hole

abstract:
  We present results of the cross-correlation analysis between active galactic
nuclei (AGNs) and galaxies at redshift 0.1-1. We obtain data of ~10,000 SDSS
AGNs in which their virial masses with a super-massive black hole (SMBH) were
estimated. The UKIDSS galaxy samples around the AGNs were obtained using the
virtual observatory. The scale length of AGN-galaxy cross-correlation for all
of the samples is measured to be r_0= 5.8+0.8-0.6 h^-1Mpc (for the fixed slope
parameter \gamma=1.8). We also derived a dependence of r_0 on the BH mass,
M_BH, and found an indication of an increasing trend of r_0 at M_BH > 10^8
Msun. It is suggested that the growth of SMBH is mainly driven by interactions
with the surrounding environment for M_BH > 10^8 Msun. On the other hand, at
M_BH <~10^8 Msun, we did not find the BH mass dependence. This would imply
that, for less massive BHs, the mass growth process can be different from that
for massive BHs.


title:
Using interpolation to reduce computing time for analysis of large but
  simple data sets with application to design of epidemiological studies

abstract:
  One way to investigate the precision of estimates likely to result from
planned experiments and planned epidemiological studies is to simulate a large
number of possible outcomes and analyse the sets of possible results. This
appears to be computationally expensive for some multi-stage designs, so choice
of designs is instead based on theoretical derivation of expected information.
This paper shows that for some types of studies the analysis of large numbers
of simulated outcomes can be achieved more rapidly by making use of
interpolation.


title: Bicircular signed-graphic matroids

abstract:
  Several matroids can be defined on the edge set of a graph. Although
historically the cycle matroid has been the most studied, in recent times, the
bicircular matroid has cropped up in several places. A theorem of Matthews from
late 1970s gives a characterization of graphs whose bicircular matroids are
graphic. We give a characterization of graphs whose bicircular matroids are
signed-graphic.


title:
Monetary Cost Optimizations for Hosting Workflow-as-a-Service in IaaS
  Clouds

abstract:
  Recently, we have witnessed workflows from science and other data-intensive
applications emerging on Infrastructure-asa-Service (IaaS) clouds, and many
workflow service providers offering workflow as a service (WaaS). The major
concern of WaaS providers is to minimize the monetary cost of executing
workflows in the IaaS cloud. While there have been previous studies on this
concern, most of them assume static task execution time and static pricing
scheme, and have the QoS notion of satisfying a deterministic deadline.
However, cloud environment is dynamic, with performance dynamics caused by the
interference from concurrent executions and price dynamics like spot prices
offered by Amazon EC2. Therefore, we argue that WaaS providers should have the
notion of offering probabilistic performance guarantees for individual
workflows on IaaS clouds. We develop a probabilistic scheduling framework
called Dyna to minimize the monetary cost while offering probabilistic deadline
guarantees. The framework includes an A*-based instance configuration method
for performance dynamics, and a hybrid instance configuration refinement for
utilizing spot instances. Experimental results with three real-world scientific
workflow applications on Amazon EC2 demonstrate (1) the accuracy of our
framework on satisfying the probabilistic deadline guarantees required by the
users; (2) the effectiveness of our framework on reducing monetary cost in
comparison with the existing approaches.


title: Well-posedness and Ill-posedness for the Nonlinear Beam Equation

abstract:
  We investigate Strichartz estimates for the nonlinear beam equation with
initial data $f\in\dot{H}^s, g\in\dot{H}^{s-2}$ and $f\in H^s, g\in H^{s-2}$.
We extend results of H. Lindblad and C. D.Sogge [10] and T. Cazenave and F. B.
Weissler [4] to nonlinear beam equations to determine the minimal regularity
that is needed to prove well-posedness and scattering results with low
regularity data. Finally, we also use small dispersion analysis of M. Christ,
J. Colliander and T. Tao [2] to prove the nonlinear beam equation is ill-posed
in defocusing case $\omega=-1$ when $ 0<s<s_c=\frac{n}{2}-\frac{4}{\kappa-1}$.


title: Decision Taking versus Promise Issuing

abstract:
  An alignment is developed between the terminology of outcome oriented
decision taking and a terminology for promise issuing. Differences and
correspondences are investigated between the concepts of decision and promise.
  For decision taking, two forms are distinguished: the external outcome
delivering form and internalized decision taking. Internalized decision taking
is brought in connection with Marc Slors' theory of self-programming.
  Examples are produced for decisions and promises in four different several
settings each connected with software technology: instruction sequence
effectuation, informational money transfer, budget announcement, and division
by zero.


title:
Forecasting and Event Detection in Internet Resource Dynamics using Time
  Series Models

abstract:
  At present Internet has emerged as a country's predominant and viable data
communication infrastructure. The Autonomous System (AS) resources which are
building blocks of the Internet are AS numbers, IPv4 and IPv6 Prefixes. AS
number growth is one of Internet infrastructure development indicators. Hence
understanding on long term trend and stochastic variation behaviour are
essential to detect significant events during the growth. In this work, time
series based approximation is considered for mathematical modelling and
forecast the yearly AS growth. The AS data of five countries namely India,
China, Japan, South Korea and Taiwan are extracted from APNIC archive. ARIMA
models with different Auto Regressive and Moving Average parameters are
identified for forecasting. Model validation, parameter estimation, point
forecast and prediction intervals with 95 % confidence levels for the five
countries are reported in the paper. The significant level change in
variations, positive growth percentage in Inter Annual Absolute Variations
(IAAV) and higher percentage of advertised ASes when compared to other
countries indicate India's fast growth and wider global reachability of
Internet infrastructure from 2007 onwards. The correlation between IAAV change
point and GDP growth period indicates that service sector industry growth is
the driving force behind significant yearly changes.


title: A lasing mechanism based on absorption boundary of gain materials

abstract:
  A new kind of mechanism of lasing is investigated experimentally. It is quite
different from the traditional laser with cavity and the random laser with
random scattering. In this mechanism, the intensity-dependent refractive index
effect and thermal lensing effects of the pump beam induce a large gradient of
the refractive index in the gain material, which forms a passive equivalent
boundary that provides the feedback in the lasing system. A real lasing system,
a liquid disk laser, is performed, it achieves 2-D omnidirectional radiation
with a high efficiency of 28%, its radiation spectral property can be explained
by resonant Raman scattering.


title:
On the Fisher information matrix for multivariate elliptically contoured
  distributions

abstract:
  The Slepian-Bangs formula provides a very convenient way to compute the
Fisher information matrix (FIM) for Gaussian distributed data. The aim of this
letter is to extend it to a larger family of distributions, namely elliptically
contoured (EC) distributions. More precisely, we derive a closed-form
expression of the FIM in this case. This new expression involves the usual term
of the Gaussian FIM plus some corrective factors that depend only on the
expectations of some functions of the so-called modular variate. Hence, for
most distributions in the EC family, derivation of the FIM from its Gaussian
counterpart involves slight additional derivations. We show that the new
formula reduces to the Slepian-Bangs formula in the Gaussian case and we
provide an illustrative example with Student distributions on how it can be
used.


title:
The optical counterpart to the X-ray transient IGR J18245-2452 in the
  globular cluster M28

abstract:
  We report on the identification of the optical counterpart to the recently
detected INTEGRAL transient IGR J18245-2452 in the Galactic globular cluster
M28. From the analysis of a multi epoch HST dataset we have identified a
strongly variable star positionally coincident with the radio and Chandra X-ray
sources associated to the INTEGRAL transient. The star has been detected during
both a quiescent and an outburst state. In the former case it appears as a
faint, unperturbed main sequence star, while in the latter state it is about
two magnitudes brighter and slightly bluer than main sequence stars. We also
detected Halpha excess during the outburst state, suggestive of active
accretion processes by the neutron star.


title:
The Galactic O-Star Spectroscopic Catalog (GOSC) and Survey (GOSSS):
  first whole-sky results and further updates

abstract:
  The Galactic O-Star Spectroscopic Survey (GOSSS) is obtaining high quality
R~2500 blue-violet spectroscopy of all Galactic stars ever classified as of O
type with B < 12 and a significant fraction of those with B = 12-14. As of June
2013, we have obtained, processed, and classified 2653 spectra of 1593 stars,
including all of the sample with B < 8 and most of the sample with B = 8-10,
making GOSSS already the largest collection of high quality O-star optical
spectra ever assembled by a factor of 3. We discuss the fraction of false
positives (stars classified as O in previous works that do not belong to that
class) and the implications of the observed magnitude distribution for the
spatial distribution of massive stars and dust within a few kpc of the Sun. We
also present new spectrograms for some of the interesting objects in the sample
and show applications of GOSSS data to the study of the intervening ISM.
Finally, we present the new version of the Galactic O-Star Catalog (GOSC),
which incorporates the data in GOSSS-DR1, and we discuss our plans for MGB, an
interactive spectral classification tool for OB stars.


title:
From Fractional Exclusion Statistics Back to Bose and Fermi
  Distributions

abstract:
  Fractional exclusion statistics (FES) is a generalization of the Bose and
Fermi statistics. Typically, systems of interacting particles are described as
ideal FES systems and the properties of the FES systems are calculated from the
properties of the interacting systems. In this paper I reverse the process and
I show that a FES system may be described in general as a gas of quasiparticles
which obey Bose or Fermi distributions; the energies of the newly defined
quasiparticles are calculated starting from the FES equations for the
equilibrium particle distribution. In the end I use a system in the effective
mass approximation as an example to show how the procedure works.


title:
Convergence of the Lasserre Hierarchy of SDP Relaxations for Convex
  Polynomial Programs without Compactness

abstract:
  The Lasserre hierarchy of semidefinite programming (SDP) relaxations is an
effective scheme for finding computationally feasible SDP approximations of
polynomial optimization over compact semi-algebraic sets. In this paper, we
show that, for convex polynomial optimization, the Lasserre hierarchy with a
slightly extended quadratic module always converges asymptotically even in the
face of non-compact semi-algebraic feasible sets. We do this by exploiting a
coercivity property of convex polynomials that are bounded below. We further
establish that the positive definiteness of the Hessian of the associated
Lagrangian at a saddle-point (rather than the objective function at each
minimizer) guarantees finite convergence of the hierarchy. We obtain finite
convergence by first establishing a new sum-of-squares polynomial
representation of convex polynomials over convex semi-algebraic sets under a
saddle-point condition. We finally prove that the existence of a saddle-point
of the Lagrangian for a convex polynomial program is also necessary for the
hierarchy to have finite convergence.


title: SUSY Phenomenology today

abstract:
  The review of the SUSY phenomenology today is given with the emphasis on
generic properties of SUSY models, SUSY searches at the LHC and in
astrophysics. Due to the absence of any definite SUSY signal at accelerators
and other experiments, we describe the allowed regions in the MSSM and NMSSM
parameter space and discuss the possibilities of SUSY manifestation in the near
future.


title:
Asymptotics for Laguerre-Sobolev type ortogonal polynomials modified
  within their oscillatory regime

abstract:
  In this paper we consider sequences of polynomials orthogonal with respect to
certain discrete Laguerre-Sobolev inner product, with two perturbations
(involving derivatives) located inside the oscillatory region for the classical
Laguerre polynomials. We focus our attention on the representation of these
polynomials in terms of the classical Laguerre polynomials and deduce the
coefficients of their corresponding five-term recurrence relation, as well as
the asymptotic behavior of these coefficients when the degree of the
polynomials tends to infinity. Also, the outer relative asymptotics of
orthogonal polynomials with respect to this discrete Sobolev inner product is
analyzed.


title:
Master equation approach to conductivity of bosonic and fermionic
  carriers in one- and two-dimensional lattices

abstract:
  We discuss the master equation approach to diffusive current of bosonic or
fermionic carriers in one- and two-dimensional lattices. This approach is shown
to reproduce all known results of the linear response theory, including the
integer quantum Hall effect for fermionic carriers. The main advantage of the
approach is that it allows to calculate the current beyond the linear response
regime where new effects are found. In particular, we show that the Hall
current can be inverted by changing orientation of the static force (electric
field) relative to the primary axes of the lattice.


title:
Exploring the Systematic Uncertainties of Type Ia Supernovae as
  Cosmological Probes

abstract:
  We explore the systematic uncertainties of using Type Ia supernovae (SNe Ia)
as cosmological probes, using the Supernova Legacy Survey Three Year data
(SNLS3). We focus on studying the possible evolution of the stretch-luminosity
parameter $\alpha$ and the color-luminosity parameter $\beta$, by allowing
$\alpha$ and $\beta$ to be function of redshift, $z$. We find no evidence for
the redshift evolution of $\alpha$. We find that without flux-averaging SNe,
$\beta$ is consistent with being a constant when only statistical uncertainties
are included, but it increases significantly with $z$ when systematic
uncertainties are also included. The evolution of $\beta$ becomes marginal when
all the SNe are flux-averaged, and $\beta$ is consistent with being a constant
when only SNe at $z\ge 0.04$ are flux-averaged. Our results are insensitive to
the lightcurve fitter used to derive the SNLS3 sample, or the functional form
of $\alpha(z)$ and $\beta(z)$ assumed. It is likely that the apparent evolution
of $\beta$ with $z$ for SNe without flux-averaging is a consequence of unknown
systematic effects; flux-averaging reduces the impact of these effects by
averaging them within each redshift bin. Assuming constant $\alpha$ and
$\beta$, we find that the flux-averaging of SNe has a significant impact on the
distance-redshift relation.


title: Second numbers in arithmetic progressions

abstract: We present an arithmetic progression of second numbers of length 28.


title: High temperature collective spin-photon coupling in a microwave cavity

abstract:
  An ensemble of N identical noninteracting spins being in thermal equilibrium
and coupled to the resonant mode of a lossless microwave cavity is studied at
arbitrary temperature T. Near T = 0 the system is known to be in a coupled
spin-photon state that manifests itself by the splitting of the cavity mode
(vacuum Rabi splitting). The cavity emission spectrum is simulated for
arbitrary T. It is shown that the spin-photon coherence can be partially
preserved for T < w sqrt{N}/2, where w is the spin excitation energy, even in
case when the spins are randomly directed. The calculations corroborate recent
room-temperature observations of the collective coupling between the microwave
cavity mode and the electron spin ensemble (NV centers in diamond, DPPH, Fe8
nanomagnets). At higher T, as a consequence of thermal excitations within the
spin ensemble, the two lines of the emission spectrum merge into a narrow line
with broad wings.


title:
Review: progress in NLTE calculations and their application to large
  data-sets

abstract:
  One of the major tasks in interpretation of data from large-scale stellar
surveys is to determine the fundamental atmospheric parameters such as
effective temperature, surface gravity, and metallicity. In most on-going and
upcoming projects, they are derived spectroscopically, with relying on
classical one-dimensional (1D) model atmospheres and the assumption of LTE.
This review discusses the present achievements and problems of non-local
thermodynamic equilibrium (NLTE) line-formation calculations for FGK-type
stars. The topics that are addressed include (i) the construction of
comprehensive model atoms for the chemical elements with complex term system,
(ii) possible systematic errors inherent in classical LTE spectroscopic
determinations of stellar parameters and chemical abundances, (iii) the
uncertainties in final NLTE results caused by the uncertainties in atomic data,
and (iv) applications of the NLTE line-formation calculations coupled to the
spatial and temporal average <3D> models to spectroscopic analyses.


title: Is global asymptotic cloning state estimation?

abstract:
  We pose the question whether the asymptotic equivalence between quantum
cloning and quantum state estimation, valid at single-copy level, still holds
when all the copies are examined jointly. For an N-to-M cloner, we consider the
overall fidelity between the state of the M output systems and the state of M
ideal copies, and we ask whether the optimal fidelity is attained by a
measure-and- prepare protocol in the limit of large M. In order to gain
intuition into the general problem, we analyze two concrete examples: i)
cloning qubit states on the equator of the Bloch sphere and ii) cloning
two-qubit maximally entangled states. In the first case, we show that the
optimal measure-and- prepare fidelity converges to the fidelity of the optimal
cloner in the limit of large M. In the second case, we restrict our attention
to economical covariant cloners, and again, we exhibit a measure- and-prepare
protocol that achieves asymptotically the optimal fidelity. Quite
counterintuitively, in both cases the optimal states that have to be prepared
in order to maximize the overall fidelity are not product states corresponding
to M identical copies, but instead suitable M-partite entangled states: the
simple protocol where one estimates the input state and re-prepares M identical
copies of the estimated state is strictly suboptimal, even in the asymptotic
limit.


title:
Internet Control Plane Event Identification using Model Based Change
  Point Detection Techniques

abstract:
  In the raise of many global organizations deploying their data centers and
content services in India, the prefix reachability performance study from
global destinations garners our attention. The events such as failures and
attacks occurring in the Internet topology have impact on Autonomous System
(AS) paths announced in the control plane and reachability of prefixes from
spatially distributed ASes. As a consequence the customer reachability to the
services in terms of increased latency and outages for a short or long time are
experienced. The challenge in control plane event detection is when the data
plane traffic is able to reach the intended destinations correctly. However
detection of such events are crucial for the operations of content and data
center industries. By monitoring the spatially distributed routing table
features like AS path length distributions, spatial prefix reachability
distribution and covering to overlap route ratio, we can detect the control
plane events. In our work, we study prefix AS paths from the publicly available
route-view data and analyze the global reachability as well as reachability to
Indian AS topology. To capture the spatial events in a single temporal pattern,
we propose a counting based measure using prefixes announced by x % of spatial
peers. Employing statistical characteristics change point detection and
temporal aberration algorithm on the time series of the proposed measure, we
identify the occurrence of long and stochastic control plane events. The impact
and duration of the events are also quantified. We validate the mechanisms over
the proposed measure using the SEA-Me-We4 cable cut event manifestations in the
control plane of Indian AS topology. The cable cut events occurred on 6th June
2012 (long term event) and 17th April 2012 (stochastic event) are considered
for validation.


title: The anisotropy of a three- and a one-form

abstract:
  We calculate the anisotropic signal associated with the coupling of a
three-form with an Abelian vector gauge field. In the simplest examples of
three-form inflation the amplification of the vector fluctuations is
exponential; this makes it almost certain that a large anisotropy will develop,
severely constraining the viability of the coupling.


title: A General Framework for Updating Belief Distributions

abstract:
  We propose a framework for general Bayesian inference. We argue that a valid
update of a prior belief distribution to a posterior can be made for parameters
which are connected to observations through a loss function rather than the
traditional likelihood function, which is recovered under the special case of
using self information loss. Modern application areas make it is increasingly
challenging for Bayesians to attempt to model the true data generating
mechanism. Moreover, when the object of interest is low dimensional, such as a
mean or median, it is cumbersome to have to achieve this via a complete model
for the whole data distribution. More importantly, there are settings where the
parameter of interest does not directly index a family of density functions and
thus the Bayesian approach to learning about such parameters is currently
regarded as problematic. Our proposed framework uses loss-functions to connect
information in the data to functionals of interest. The updating of beliefs
then follows from a decision theoretic approach involving cumulative loss
functions. Importantly, the procedure coincides with Bayesian updating when a
true likelihood is known, yet provides coherent subjective inference in much
more general settings. Connections to other inference frameworks are
highlighted.


title: Quantum state estimation with unknown measurements

abstract:
  Improved measurement techniques are central to technological development and
foundational scientific exploration. Quantum optics relies upon detectors
sensitive to non-classical features of light, enabling precise tests of
physical laws and quantum-enhanced technologies such as precision measurement
and secure communications. Accurate detector response calibration for
quantum-scale inputs is key to future research and development in these cognate
areas. To address this requirement quantum detector tomography (QDT) has been
recently introduced. However, the QDT approach becomes increasingly challenging
as the complexity of the detector response and input space grows. Here we
present the first experimental implementation of a versatile alternative
characterization technique to address many-outcome quantum detectors by
limiting the input calibration region. To demonstrate the applicability of this
approach the calibrated detector is subsequently used to estimate non-classical
photon number states.


title: On the essential dimension of coherent sheaves

abstract:
  We characterize all fields of definition for a given coherent sheaf over a
projective scheme in terms of projective modules over a finite-dimensional
endomorphism algebra. This yields general results on the essential dimension of
such sheaves. Applying them to vector bundles over a smooth projective curve C,
we obtain an upper bound for the essential dimension of their moduli stack. The
upper bound is sharp if the conjecture of Colliot-Th\'el\`ene, Karpenko and
Merkurjev holds. We find that the genericity property proved for
Deligne-Mumford stacks by Brosnan, Reichstein and Vistoli still holds for this
Artin stack, unless the curve C is elliptic.


title:
Changes in the self-energy and d-wave pairing strength with doping in
  overdoped La(2-x)Sr(x)CuO4

abstract:
  Angle resolved photoemission spectroscopy (ARPES) studies of the overdoped
cuprate superconductor La$_{2-x}$Sr$_x$CuO$_4$ find only small changes in the
near nodal electron self energy over a spectral range of several hundred meV as
the doping increases from x=0.2 to x=0.3 and the superconducting transition
temperature T_c decreases from 32K to 0K. These measurements put constraints on
the structure of the electron-electron interaction. Here we show that a
spin-fluctuation interaction leads to behavior which is consistent with these
experimental results.


title:
Characterization of singular numbers of products of operators in matrix
  algebras and finite von Neumann algebras

abstract:
  We characterize in terms of inequalities the possible generalized singular
numbers of a product AB of operators A and B having given generalized singular
numbers, in an arbitrary finite von Neumann algebra. We also solve the
analogous problem in matrix algebras M_n(C), which seems to be new insofar as
we do not require A and B to be invertible.


title: Excited-State Quantum Phase Transitions in Dicke Superradiance Models

abstract:
  We derive analytical results for various quantities related to the
excited-state quantum phase transitions in a class of Dicke superradiance
models in the semiclassical limit. Based on a calculation of a partition sum
restricted to Dicke states, we discuss the singular behavior of the derivative
of the density of states and find observables like the mean (atomic) inversion
and the boson (photon) number and its fluctuations at arbitrary energies.
Criticality depends on energy and a parameter that quantifies the relative
weight of rotating versus counter-rotating terms, and we find a close analogy
to the logarithmic and jump-type non-analyticities known from the
Lipkin-Meshkov-Glick model.


title: Graph Derangements

abstract:
  We introduce the notion of a graph derangement, which naturally interpolates
between perfect matchings and Hamiltonian cycles. We give a necessary and
sufficient condition for the existence of graph derangements on a locally
finite graph. This result was first proved by W.T. Tutte in 1953 by applying
some deeper results on digraphs. We give a new, simple proof which amounts to a
reduction to the (Menger-Egervary-Konig-)Hall(-Hall) Theorem on transversals of
set systems. Finally, we consider the problem of classifying all cycle types of
graph derangements on m x n checkerboard graphs. Our presentation does not
assume any prior knowledge in graph theory or combinatorics: all definitions
and proofs of needed theorems are given.


title:
Large Scale Cosmic Perturbation from Evaporation of Primordial Black
  Holes

abstract:
  We present a novel mechanism to generate the cosmic perturbation from
evaporation of primordial black holes. A mass of a field is fluctuated if it is
given by a vacuum expectation value of a light scalar field because of the
quantum fluctuation during inflation. The fluctuated mass causes variations of
the evaporation time of the primordial black holes. Therefore provided the
primordial black holes dominate the universe when they evaporate, primordial
cosmic perturbations are generated. We find that the amplitude of the large
scale curvature perturbation generated in this scenario can be consistent with
the observed value. Interestingly, our mechanism works even if all fields which
are responsible for inflation and the generation of the cosmic perturbation are
decoupled from the visible sector except for the gravitational interaction. An
implication to the running spectral index is also discussed.


title: Group testing algorithms: bounds and simulations

abstract:
  We consider the problem of non-adaptive noiseless group testing of $N$ items
of which $K$ are defective. We describe four detection algorithms: the COMP
algorithm of Chan et al.; two new algorithms, DD and SCOMP, which require
stronger evidence to declare an item defective; and an essentially optimal but
computationally difficult algorithm called SSS. By considering the asymptotic
rate of these algorithms with Bernoulli designs we see that DD outperforms
COMP, that DD is essentially optimal in regimes where $K \geq \sqrt N$, and
that no algorithm with a nonadaptive Bernoulli design can perform as well as
the best non-random adaptive designs when $K > N^{0.35}$. In simulations, we
see that DD and SCOMP far outperform COMP, with SCOMP very close to the optimal
SSS, especially in cases with larger $K$.


title: The tridendriform structure of a Magnus expansion

abstract:
  The notion of trees plays an important role in Butcher's B-series. More
recently, a refined understanding of algebraic and combinatorial structures
underlying the Magnus expansion has emerged thanks to the use of rooted trees.
We follow these ideas by further developing the observation that the logarithm
of the solution of a lihear first-order finite-difference equation can be
written in terms of the Magnus expansion taking place in a pre-Lie algebra. By
using basic combinatorics on planar reduced trees we derive a closed formula
for the Magnus expansion in the context of free tridendriform algebra. The
tridendriform algebra structure on word quasi-symmetric functions permits us to
derive a discrete analogue of the Mielnik-Plebanski-Strichartz formula for this
logarithm.


title: Rashbon condensation in a Bose gas with Rashba spin-orbit coupling

abstract:
  We show that in a two-component Bose gas with Rashba spin-orbit coupling
(SOC) two atoms can form bound states (Rashbons) with any intra-species
scattering length. At zero center-of-mass momentum there are two degenerate
Rashbons due to time-reversal symmetry, but the degeneracy is lifted at finite
in-plane momentum with two different effective masses. A stable Rashbon
condensation can be created in a dilute system with weakly attractive
intra-species and repulsive inter-species interactions. The critical
temperature of Rashbon condensation is about six times smaller than the BEC
transition temperature of an ideal Bose gas. Due Rashba SOC, excitations in the
Rashbon condensation phase are anisotropic in momentum space.


title: Pure Gravitational Back-Reaction Observables

abstract:
  After discussing the various issues regarding and requirements on pure
quantum gravitational observables in homogeneous-isotropic conditions, we
construct a composite operator observable satisfying most of them. We also
expand it to first order in the loop counting parameter and suggest it as a
physical quantifier of gravitational back-reaction in an initially inflating
cosmology.


title: The Stark problem in the Weierstrassian formalism

abstract:
  We present a new general, complete closed-form solution of the Stark problem
in terms of Weierstrass elliptic and related functions. With respect to
previous treatments of the problem, our analysis is exact and valid for all
values of the external force field, and it is expressed via unique formul\ae{}
valid for all initial conditions and parameters of the system. The simple form
of the solution allows us to perform a thorough investigation of the properties
of the dynamical system, including the identification of quasi-periodic and
periodic orbits, the formulation of a simple analytical criterion to determine
the boundness of the trajectory, and the characterisation of the equilibrium
points.

categories: math-ph astro-ph.EP math.MP physics.class-ph physics.space-ph


title:
Swift/XRT orbital monitoring of the candidate supergiant fast X-ray
  transient IGR J17354-3255

abstract:
  We report on the Swift/X-ray Telescope (XRT) monitoring of the field of view
around the candidate supergiant fast X-ray transient (SFXT) IGR J17354-3255,
which is positionally associated with the AGILE/GRID gamma-ray transient AGL
J1734-3310. Our observations, which cover 11 days for a total on-source
exposure of about 24 ks, span 1.2 orbital periods (P_orb=8.4474 d) and are the
first sensitive monitoring of this source in the soft X-rays. These new data
allow us to exploit the timing variability properties of the sources in the
field to unambiguously identify the soft X-ray counterpart of IGR J17354-3255.
The soft X-ray light curve shows a moderate orbital modulation and a dip. We
investigated the nature of the dip by comparing the X-ray light curve with the
prediction of the Bondi-Hoyle-Lyttleton accretion theory, assuming both
spherical and nonspherical symmetry of the outflow from the donor star. We
found that the dip cannot be explained with the X-ray orbital modulation. We
propose that an eclipse or the onset of a gated mechanism is the most likely
explanation for the observed light curve.


title:
A symmetric generalization of Sturm-Liouville problems in $q$-difference
  spaces

abstract:
  Classical Sturm-Liouville problems of $q$-difference variables are extended
for symmetric discrete functions such that the corresponding solutions preserve
the orthogonality property. Some illustrative examples are given in this sense.


title:
Achieving tunable surface tension in the pseudopotential lattice
  Boltzmann modeling of multiphase flows

abstract:
  In this paper, we aim to address an important issue about the pseudopotential
lattice Boltzmann (LB) model, which has attracted much attention as a
mesoscopic model for simulating interfacial dynamics of complex fluids, but
suffers from the problem that the surface tension cannot be tuned independently
of the density ratio. In the literature, a multi-range potential was devised to
adjust the surface tension [Sbragaglia et al., Phys. Rev. E 75, 026702 (2007)].
However, it was recently found that the density ratio of the system will be
changed when the multi-range potential is employed to adjust the surface
tension. A new approach is therefore proposed in the present work. The basic
strategy is to add a source term to the LB equation so as to tune the surface
tension of the pseudopotential LB model. The proposed approach can guarantee
that the adjustment of the surface tension does not affect the mechanical
stability condition of the pseudopotential LB model, and thus provides a
separate control of the surface tension and the density ratio. Meanwhile, it
still retains the mesoscopic feature and the computational simplicity of the
pseudopotential LB model. Numerical simulations are carried out for stationary
droplets, capillary waves, and droplet splashing on a thin liquid film. The
numerical results demonstrate that the proposed approach is capable of
achieving a tunable surface tension over a very wide range and can keep the
density ratio unchanged when adjusting the surface tension.


title: Rigid rational homotopy types

abstract:
  In this paper we define a rigid rational homotopy type, associated to any
variety $X$ over a perfect field $k$ of positive characteristic. We prove
comparison theorems with previous definitions in the smooth and proper, and
log-smooth and proper case. Using these, we can show that if $k$ is a finite
field, then the Frobenius structure on the higher rational homotopy groups is
mixed. We also define a relative rigid rational homotopy type, and use it to
define a homotopy obstruction for the existence of sections.


title:
Influence of the magnetic material on tunneling magnetoresistance and
  spin-transfer torque in tunnel junctions: Ab initio studies

abstract:
  The dependence of tunneling magnetoresistance and spin-transfer torque in
FeCo/MgO/FeCo tunnel junctions on the Co concentration and the bias voltage are
investigated ab initio. We find that the tunneling magnetoresistance decreases
with the Co concentration in contradiction with previous calculations but in
agreement with recent experiments. This dependence is explained from bulk
properties of the alloys. By using a realistic description of the disorder in
the alloys we can show that even small amounts of disorder lead to a drastic
drop in the tunneling magnetoresistance. This provides a quantitative
explanation of the difference between calculated and measured values.
  The spin-transfer torque shows a linear voltage dependence for the in-plane
component and a quadratic for the out-of-plane component for all concentrations
at small bias voltages. In particular, the linear slope of the in-plane torque
is independent of the concentration. For high bias voltages the in-plane torque
shows a strong nonlinear deviation from the linear slope for high Co
concentrations. This is explained from the same effects which govern the
tunneling magnetoresistance.


title: Explicit Solution to the Constant Radial Acceleration Problem

abstract:
  While the constant radial acceleration problem is known to be integrable and
has received some recent attention in an orbital mechanics context, a closed
form explicit solution, relating the state variables to a time parameter, has
eluded all researchers so far. It is here shown how such a solution exists and
is elegantly expressed in terms of the Weierstrass elliptic and related
functions. Previously known facts can be derived from the new explicit solution
and new insights are revealed.


title: Melting of Wigner-like Lattice of Parallel Polarized Dipoles

abstract:
  We show that a triangular lattice consisting of dipolar molecules pointing
orthogonal to the plane undergoes a first-order defect melting transition.


title: On non-dissipative and dissipative qubit manifolds

abstract:
  The trajectories of a qubit dynamics over the two-sphere are shown to be
geodesics of certain Riemannian or physically-sound Lorentzian manifolds, both
in the non-dissipative and dissipative formalisms, when using action-angle
variables. Several aspects of the geometry and topology of these manifolds
(qubit manifolds) have been studied for some special physical cases.