title:
The M87 Black Hole Mass from Gas-dynamical Models of Space Telescope
  Imaging Spectrograph Observations

abstract:
  The supermassive black hole of M87 is one of the most massive black holes
known and has been the subject of several stellar and gas-dynamical mass
measurements; however the most recent revision to the stellar-dynamical black
hole mass measurement is a factor of about two larger than the previous
gas-dynamical determinations. Here, we apply comprehensive gas-dynamical models
that include the propagation of emission-line profiles through the telescope
and spectrograph optics to new Space Telescope Imaging Spectrograph
observations from the Hubble Space Telescope. Unlike the previous gas-dynamical
studies of M87, we map out the complete kinematic structure of the
emission-line disk within about 40 pc from the nucleus, and find that a small
amount of velocity dispersion internal to the gas disk is required to match the
observed line widths. We examine a scenario in which the intrinsic velocity
dispersion provides dynamical support to the disk, and determine that the
inferred black hole mass increases by only 6%. Incorporating this effect into
the error budget, we ultimately measure a mass of M_BH = (3.5^{+0.9}_{-0.7}) x
10^9 M_sun (68% confidence). Our gas-dynamical black hole mass continues to
differ from the most recent stellar-dynamical mass by a factor of two,
underscoring the need for carrying out more cross-checks between the two main
black hole mass measurement methods.


title: Explicit Hilbert-Kunz functions of 2 x 2 determinantal rings

abstract:
  Let $k[X] = k[x_{i,j}: i = 1,..., m; j = 1,..., n]$ be the polynomial ring in
$m n$ variables $x_{i,j}$ over a field $k$ of arbitrary characteristic. Denote
by $I_2(X)$ the ideal generated by the $2 \times 2$ minors of the generic $m
\times n$ matrix $[x_{i,j}]$. We give a closed formulation for the dimensions
of the $k$-vector space $k[X]/(I_2(X) + (x_{1,1}^q,..., x_{m,n}^q))$ as $q$
varies over all positive integers, i.e., we give a closed form for the
generalized Hilbert-Kunz function of the determinantal ring $k[X]/I_{2}[X]$. We
also give a closed formulation of dimensions of related quotients of
$k[X]/I_{2}[X]$. In the process we establish a formula for the numbers of some
compositions (ordered partitions of integers), and we give a proof of a new
binomial identity.


title: Energy trapping from Hagedorn densities of states

abstract:
  In this note, we construct simple stochastic toy models for holographic gauge
theories in which distributions of energy on a collection of sites evolve by a
master equation with some specified transition rates. We build in only energy
conservation, locality, and the standard thermodynamic requirement that all
states with a given energy are equally likely in equilibrium. In these models,
we investigate the qualitative behavior of the dynamics of the energy
distributions for different choices of the density of states for the individual
sites. For typical field theory densities of states (\log(\rho(E)) ~
E^{\alpha<1}), the model gives diffusive behavior in which initially localized
distributions of energy spread out relatively quickly. For large N gauge
theories with gravitational duals, the density of states for a finite volume of
field theory degrees of freedom typically includes a Hagedorn regime
(\log(\rho(E)) ~ E). We find that this gives rise to a trapping of energy in
subsets of degrees of freedom for parametrically long time scales before the
energy leaks away. We speculate that this Hagedorn trapping may be part of a
holographic explanation for long-lived gravitational bound states (black holes)
in gravitational theories.


title:
High velocity outflows from young star-forming galaxies in the UKIDSS
  Ultra-Deep Survey

abstract:
  We investigate galactic-scale outflows in the redshift range 0.71 < z < 1.63,
using 413 K-band selected galaxies observed in the spectroscopic follow-up of
the UKIDSS Ultra-Deep Survey (UDSz). The galaxies have an average stellar mass
of ~10^9.5 solar masses and span a wide range in rest-frame colours,
representing typical star-forming galaxies at this epoch. We stack the spectra
by various galaxy properties, including stellar mass, [OII] equivalent width,
star-formation rate, specific star-formation rate and rest-frame spectral
indices. We find that outflows are present in virtually all spectral stacks,
with velocities ranging from 100-1000 km s^-1, indicating that large-scale
outflowing winds are a common property at these redshifts. The highest velocity
outflows (>500 km s^-1) are found in galaxies with the highest stellar masses
and the youngest stellar populations. Our findings suggest that high velocity
galactic outflows are mostly driven by star-forming processes rather than AGN,
with implied mass outflow rates comparable to the rates of star formation. Such
behaviour is consistent with models required to reproduce the high-redshift
mass-metallicity relation.


title:
First observational constraints on tensor non-Gaussianity sourced by
  primordial magnetic fields from cosmic microwave background

abstract:
  Primordial magnetic fields (PMFs) create a large squeezed-type
non-Gaussianity in tensor perturbation, which generates non-Gaussian
temperature fluctuations in the cosmic microwave background (CMB). We for the
first time derive an observational constraint on such a tensor non-Gaussianity
from observed CMB maps. Analyzing temperature maps of the WMAP 7-year data, we
find that such a tensor non-Gaussianity is consistent with zero. This gives an
upper bound on PMF strength smoothed on $1 ~ {\rm Mpc}$ as $B_{1 ~ \rm Mpc} <
3.1 ~{\rm nG}$ at $95%$ C.L.


title:
On Adaptive Control with Closed-loop Reference Models: Transients,
  Oscillations, and Peaking

abstract:
  One of the main features of adaptive systems is an oscillatory convergence
that exacerbates with the speed of adaptation. Recently it has been shown that
Closed-loop Reference Models (CRMs) can result in improved transient
performance over their open-loop counterparts in model reference adaptive
control. In this paper, we quantify both the transient performance in the
classical adaptive systems and their improvement with CRMs. In addition to
deriving bounds on L-2 norms of the derivatives of the adaptive parameters
which are shown to be smaller, an optimal design of CRMs is proposed which
minimizes an underlying peaking phenomenon. The analytical tools proposed are
shown to be applicable for a range of adaptive control problems including
direct control and composite control with observer feedback. The presence of
CRMs in adaptive backstepping and adaptive robot control are also discussed.
Simulation results are presented throughout the paper to support the
theoretical derivations.


title:
Fluctuation-Dissipation Theorem in an Isolated System of Quantum Dipolar
  Bosons after a Quench

abstract:
  We examine the validity of fluctuation-dissipation relations in isolated
quantum systems taken out of equilibrium by a sudden quench. We focus on the
dynamics of trapped hard-core bosons in one-dimensional lattices with dipolar
interactions whose strength is changed during the quench. We find that
fluctuation-dissipation relations hold if the system is nonintegrable after the
quench. They also hold if the system is integrable after the quench if the
initial state is an equilibrium state of a nonintegrable Hamiltonian. However,
they fail if the system is integrable both before and after quenching.


title: KAPAO: a MEMS-based natural guide star adaptive optics system

abstract:
  We describe KAPAO, our project to develop and deploy a low-cost,
remote-access, natural guide star adaptive optics (AO) system for the Pomona
College Table Mountain Observatory (TMO) 1-meter telescope. We use a
commercially available 140-actuator BMC MEMS deformable mirror and a version of
the Robo-AO control software developed by Caltech and IUCAA. We have structured
our development around the rapid building and testing of a prototype system,
KAPAO-Alpha, while simultaneously designing our more capable final system,
KAPAO-Prime. The main differences between these systems are the prototype's
reliance on off-the-shelf optics and a single visible-light science camera
versus the final design's improved throughput and capabilities due to the use
of custom optics and dual-band, visible and near-infrared imaging. In this
paper, we present the instrument design and on-sky closed-loop testing of
KAPAO-Alpha as well as our plans for KAPAO-Prime. The primarily
undergraduate-education nature of our partner institutions, both public (Sonoma
State University) and private (Pomona and Harvey Mudd Colleges), has enabled us
to engage physics, astronomy, and engineering undergraduates in all phases of
this project. This material is based upon work supported by the National
Science Foundation under Grant No. 0960343.


title: Calibrating CIV-based black hole mass estimators

abstract:
  We present the single-epoch black hole mass estimators based on the CIV (1549
A) broad emission line, using the updated sample of the reverberation-mapped
AGNs and high-quality UV spectra. By performing multi-component spectral
fitting analysis, we measure the CIV line widths (FWHM_CIV) and line dispersion
(sigma_CIV) and the continuum luminosity at 1350 A (L_1350) to calibrate the
CIV-based mass estimators. By comparing with the Hbeta reverberation-based
masses, we provide new mass estimators with the best-fit relationships, i.e.,
M_BH \propto L_1350 ^ (0.50+-0.07) sigma_CIV ^2 and M_BH \propto L_1350 ^
(0.52+-0.09) FWHM_CIV ^ (0.56+-0.48). The new CIV-based mass estimators show
significant mass-dependent systematic difference compared to the estimators
commonly used in the literature. Using the published Sloan Digital Sky Survey
QSO catalog, we show that the black hole mass of high-redshift QSOs decreases
on average by ~0.25 dex if our recipe is adopted.


title: An Improved Approach for Word Ambiguity Removal

abstract:
  Word ambiguity removal is a task of removing ambiguity from a word, i.e.
correct sense of word is identified from ambiguous sentences. This paper
describes a model that uses Part of Speech tagger and three categories for word
sense disambiguation (WSD). Human Computer Interaction is very needful to
improve interactions between users and computers. For this, the Supervised and
Unsupervised methods are combined. The WSD algorithm is used to find the
efficient and accurate sense of a word based on domain information. The
accuracy of this work is evaluated with the aim of finding best suitable domain
of word.


title: Observations of The High Mass X-ray Binary A0535+26 in Quiescence

abstract:
  We have analyzed 3 observations of the High Mass X-ray Binary A0535+26
performed by the Rossi X-ray Timing Explorer (RXTE) 3, 5, and 6 months after
the last outburst in 2011 February. We detect pulsations only in the second
observation. The 3-20 keV spectra can be fit equally well with either an
absorbed power law or absorbed thermal bremsstrahlung model. Re-analysis of 2
earlier RXTE observations made 4 years after the 1994 outburst, original
BeppoSAX observations 2 years later, re-analysis of 4 EXOSAT observations made
2 years after the last 1984 outburst, and a recent XMM-Newton observation in
2012 reveal a stacked, quiescent flux level decreasing from ~2 to <1 x 10^{-11}
ergs/cm2/s over 6.5 years after outburst. Detection of pulsations during half
of the quiescent observations would imply that accretion onto the magnetic
poles of the neutron star continues despite the fact that the circumstellar
disk may no longer be present. The accretion could come from material built-up
at the corotation radius or from an isotropic stellar wind.


title:
Supervised Heterogeneous Multiview Learning for Joint Association Study
  and Disease Diagnosis

abstract:
  Given genetic variations and various phenotypical traits, such as Magnetic
Resonance Imaging (MRI) features, we consider two important and related tasks
in biomedical research: i)to select genetic and phenotypical markers for
disease diagnosis and ii) to identify associations between genetic and
phenotypical data. These two tasks are tightly coupled because underlying
associations between genetic variations and phenotypical features contain the
biological basis for a disease. While a variety of sparse models have been
applied for disease diagnosis and canonical correlation analysis and its
extensions have bee widely used in association studies (e.g., eQTL analysis),
these two tasks have been treated separately. To unify these two tasks, we
present a new sparse Bayesian approach for joint association study and disease
diagnosis. In this approach, common latent features are extracted from
different data sources based on sparse projection matrices and used to predict
multiple disease severity levels based on Gaussian process ordinal regression;
in return, the disease status is used to guide the discovery of relationships
between the data sources. The sparse projection matrices not only reveal
interactions between data sources but also select groups of biomarkers related
to the disease. To learn the model from data, we develop an efficient
variational expectation maximization algorithm. Simulation results demonstrate
that our approach achieves higher accuracy in both predicting ordinal labels
and discovering associations between data sources than alternative methods. We
apply our approach to an imaging genetics dataset for the study of Alzheimer's
Disease (AD). Our method identifies biologically meaningful relationships
between genetic variations, MRI features, and AD status, and achieves
significantly higher accuracy for predicting ordinal AD stages than the
competing methods.


title:
Traitement approximatif des requ\^etes flexibles avec groupement
  d'attributs et jointure

abstract:
  This paper addresses the problem of approximate processing for flexible
queries in the form SELECT-FROM-WHERE-GROUP BY with join condition. It offers a
flexible framework for online aggregation while promoting response time at the
expense of result accuracy.


title:
Physical Conditions in the Interstellar Medium of High-Redshift
  Galaxies: Mass Budget and Gas Excitation

abstract:
  Following the first pioneering efforts in the 1990s that have focused on the
detection of the molecular interstellar medium in high redshift galaxies,
recent years have brought great advances in our understanding of the actual
physical properties of the gas that set the conditions for star formation.
Observations of the ground-state CO J=1-0 line have furnished crucial
information on the total masses of the gas reservoirs, as well as reliable
dynamical mass and size estimates. Detailed studies of rotational ladders of CO
have provided insight on the temperature and density of the gas. Investigations
of the very dense gas associated with actively star-forming regions in the
interstellar medium, most prominently through HCN and HCO+, have enabled a
better understanding of the nature of the extreme starbursts found in many
high-redshift galaxies, which exceed the star formation rates of their most
active present-day counterparts by an order of magnitude. Key progress in this
area has been made through targeted studies of few, well-selected systems with
current facilities. With the completion of the Karl G. Jansky Very Large Array
and the Atacama Large (sub)Millimeter Array, it will become possible to develop
a more general framework for the interpretation of these investigations based
on unbiased studies of "normal" star-forming galaxies back to the earliest
cosmic epochs.


title:
Zero-one law for directional transience of one dimensional excited
  random walks

abstract:
  The probability that a one dimensional excited random walk in stationary
ergodic and elliptic cookie environment is transient to the right (left) is
either zero or one. This solves a problem posed by Kosygina and Zerner [8].


title: Small black holes in the large D limit

abstract:
  The large D limit of AdS_2 X S^{D-2} solutions in the particular
higher-derivative Lovelock-type theory is analyzed. The theory and the
solutions were originally considered in an attempt to effectively describe
near-horizon behavior of D-dimensional spherically symmetric 2-charge small
extremal black holes which in superstring theory context are assumed to
correspond to configurations in S^1 \times T^{9-D} compactification schemes in
which fundamental string is wound around circle S^1. Though in D -> \infty
limit the action contains infinite number of higher-derivative terms, their
contributions to equations of motion sum into simple exponential form which
allows us to find explicit solutions. A simplicity of this example gives us the
opportunity to study some connections between \alpha' and 1/D expansions. In
the leading order in 1/D the relation between the string parameter \alpha' and
the radius of the horizon r_h (in the string frame) satisfies r_h ~ D
\sqrt{\alpha'}, i.e., we obtain an explicit realization of the relation
inferred by Emparan et al. in the different context of large black holes in the
ordinary Einstein gravity where \alpha' is not manifestly present.


title: TimeML-strict: clarifying temporal annotation

abstract:
  TimeML is an XML-based schema for annotating temporal information over
discourse. The standard has been used to annotate a variety of resources and is
followed by a number of tools, the creation of which constitute hundreds of
thousands of man-hours of research work. However, the current state of
resources is such that many are not valid, or do not produce valid output, or
contain ambiguous or custom additions and removals. Difficulties arising from
these variances were highlighted in the TempEval-3 exercise, which included its
own extra stipulations over conventional TimeML as a response.
  To unify the state of current resources, and to make progress toward easy
adoption of its current incarnation ISO-TimeML, this paper introduces
TimeML-strict: a valid, unambiguous, and easy-to-process subset of TimeML. We
also introduce three resources -- a schema for TimeML-strict; a validator tool
for TimeML-strict, so that one may ensure documents are in the correct form;
and a repair tool that corrects common invalidating errors and adds
disambiguating markup in order to convert documents from the laxer TimeML
standard to TimeML-strict.


title: Dynamical description of Tychonian Universe

abstract:
  Using Mach's principle, we will show that the observed diurnal and annual
motion of the Earth can just as well be accounted as the diurnal rotation and
annual revolution of the Universe around the fixed and centered Earth. This can
be performed by postulating the existence of vector and scalar potentials
caused by the simultaneous motion of the masses in the Universe, including the
distant stars.


title:
Radial and non radial ground states for a class of dilation invariant
  fourth order semilinear elliptic equations on $\mathbb{R}^{n}$

abstract:
  We prove existence of extremal functions for some Rellich-Sobolev type
inequalities involving the $L^{2}$ norm of the Laplacian as a leading term and
the $L^{2}$ norm of the gradient, weighted with a Hardy potential. Moreover we
exhibit a breaking symmetry phenomenon when the nonlinearity has a growth close
to the critical one and the singular potential increases in strength.


title:
Excitation spectra from angular momentum projection of Hartree-Fock
  states and the configuration-interaction shell-model

abstract:
  We make numerical comparison of spectra from angular-momentum projection on
Hartree-Fock states with spectra from configuration-interaction nuclear
shell-model calculations, all carried out in the same model spaces (in this
case the sd, lower pf, and p-sd_5/2 shells) and using the same input
Hamiltonians. We find, unsurprisingly, that the low-lying excitation spectra
for rotational nuclides are well reproduced, but the spectra for vibrational
nuclides, and more generally the complex specta for odd-A and odd-odd nuclides
are less well reproduced in detail.


title:
Symmetries of the Free Schr\"odinger Equation in the Non-Commutative
  Plane

abstract:
  We study all the symmetries of the free Schr\"odinger equation in the
non-commutative plane. These symmetry transformations form an
infinite-dimensional Weyl algebra that appears naturally from a two-dimensional
Heisenberg algebra generated by Galilean boosts and momenta. These infinite
high symmetries could be useful for constructing non-relativistic interacting
higher spin theories. A finite-dimensional subalgebra is given by the
Schr\"odinger algebra which, besides the Galilei generators, contains also the
dilatation and the expansion. We consider the quantization of the symmetry
generators in both the reduced and extended phase spaces, and discuss the
relation between both approaches.


title:
Self Configurable Re-link Establishment using Continuous Neighbor
  Discovery in Asynchronous Sensor Networks

abstract:
  A Sensor network generally has a large number of sensor nodes that are
deployed at some audited site. In most sensor networks the nodes are static.
Nevertheless, node connectivity is subject to changes because of disruptions in
wireless communication, transmission power changes, or loss of synchronization
between neighbouring nodes, so there is a need to maintain synchronization
between the neighbouring nodes in order to have efficient communication. Hence
even after a sensor is aware of its immediate neighbours, it must continuously
maintain its view a process we call continuous neighbour discovery. In this
proposed work we are maintaining synchronization between neighbouring nodes so
that the sensor network will be always active.


title: Landau-Lifshitz theory of the longitudinal spin Seebeck effect

abstract:
  Thermal-bias-induced spin angular momentum transfer between a paramagnetic
metal and ferromagnetic insulator is studied theoretically based on the
stochastic Landau-Lifshitz-Gilbert (LLG) phenomenology. Magnons in the
ferromagnet establish a nonequilibrium steady state by equilibrating with
phonons via bulk Gilbert damping and electrons in the paramagnet via spin
pumping, according to the fluctuation-dissipation theorem. Subthermal magnons
and the associated spin currents are treated classically, while the appropriate
quantum crossover is imposed on high-frequency magnetic fluctuations. We
identify several length scales in the ferromagnet, which govern qualitative
changes in the dependence of the thermally-induced spin current on the magnetic
film thickness.


title: Unimodular triangulations of dilated 3-polytopes

abstract:
  A seminal result in the theory of toric varieties, due to Knudsen, Mumford
and Waterman (1973), asserts that for every lattice polytope $P$ there is a
positive integer $k$ such that the dilated polytope $kP$ has a unimodular
triangulation. In dimension 3, Kantor and Sarkaria (2003) have shown that $k=4$
works for every polytope. But this does not imply that every $k>4$ works as
well. We here study the values of $k$ for which the result holds showing that:
  1. It contains all composite numbers.
  2. It is an additive semigroup.
  These two properties imply that the only values of $k$ that may not work
(besides 1 and 2, which are known not to work) are $k\in\{3,5,7,11\}$. With an
ad-hoc construction we show that $k=7$ and $k=11$ also work, except in this
case the triangulation cannot be guaranteed to be "standard" in the boundary.
All in all, the only open cases are $k=3$ and $k=5$.


title: The explanation of eclipses in Greco-Roman antiquity

abstract:
  The search of a rational explanation of eclipses pervades the beginnings of
philosophical and scientific thought. Within this intellectual frame, the
knowledge of the "saros cycle" (a cycle of 18 years, 10 or 11 days and 1/3 of a
day that separates two successive sun or moon eclipses of similar features),
inherited by the Greeks from the Babylonians, favored important theoretical
developments in the West. The purpose of this paper is to present, briefly and
schematically, a) the ancient theorizations on the causes of eclipses, b) the
range of predictability of eclipses in Antiquity, c) the warnings -transmitted
by some classical writers- to those who want to observe in naked eyes a solar
eclipse, and d) the popular beliefs and social practices upon the occurrence of
unexpected eclipses in ancient times.


title:
Radial distribution function in a diffusion Monte Carlo simulation of a
  Fermion fluid between the ideal gas and the Jellium model

abstract:
  We study, through the diffusion Monte Carlo method, a spin one-half fermion
fluid, in the three dimensional Euclidean space, at zero temperature. The point
particles, immersed in a uniform "neutralizing" background, interact with a
pair-potential which can be continuously changed from zero to the Coulomb
potential depending on a parameter $\mu$. We determine the radial distribution
functions of the system for various values of density, $\mu$, and polarization.
We discuss about the importance, in a computer experiment, of the choice of
suitable estimators to measure a physical quantity. The radial distribution
function is determined through the usual histrogram estimator and through an
estimator determined via the use of the Hellmann and Feynman theorem. In a
diffusion Monte Carlo simulation the latter route introduces a new bias to the
measure of the radial distribution function due to the choice of the auxiliary
function. This bias is independent from the usual one due to the choice of the
trial wave function. A brief account of the results from this study were
presented in a recent communication [R. Fantoni, Solid State Communications,
{\bf 159}, 106 (2013)].

categories: cond-mat.str-el cond-mat.stat-mech physics.chem-ph physics.comp-ph


title:
Control of focusing forces and emittances in plasma-based accelerators
  using near-hollow plasma channels

abstract:
  A near-hollow plasma channel, where the plasma density in the channel is much
less than the plasma density in the walls, is proposed to provide independent
control over the focusing and accelerating forces in a plasma accelerator. In
this geometry the low density in the channel contributes to the focusing
forces, while the accelerating fields are determined by the high density in the
channel walls. The channel also provides guiding for intense laser pulses used
for wakefield excitation. In certain regimes, both electron and positron beams
can be accelerated and focused in a nearly symmetric fashion. Near-hollow
plasma channels can effectively mitigate emittance growth due to Coulomb
scattering for high-energy physics applications.


title:
Coverage and adoption of altmetrics sources in the bibliometric
  community

abstract:
  Altmetrics, indices based on social media platforms and tools, have recently
emerged as alternative means of measuring scholarly impact. Such indices assume
that scholars in fact populate online social environments, and interact with
scholarly products there. We tested this assumption by examining the use and
coverage of social media environments amongst a sample of bibliometricians. As
expected, coverage varied: 82% of articles published by sampled
bibliometricians were included in Mendeley libraries, while only 28% were
included in CiteULike. Mendeley bookmarking was moderately correlated (.45)
with Scopus citation. Over half of respondents asserted that social media tools
were affecting their professional lives, although uptake of online tools varied
widely. 68% of those surveyed had LinkedIn accounts, while Academia.edu,
Mendeley, and ResearchGate each claimed a fifth of respondents. Nearly half of
those responding had Twitter accounts, which they used both personally and
professionally. Surveyed bibliometricians had mixed opinions on altmetrics'
potential; 72% valued download counts, while a third saw potential in tracking
articles' influence in blogs, Wikipedia, reference managers, and social media.
Altogether, these findings suggest that some online tools are seeing
substantial use by bibliometricians, and that they present a potentially
valuable source of impact data.


title: Percolation and disorder-resistance in cellular automata

abstract:
  We rigorously prove a form of disorder-resistance for a class of
one-dimensional cellular automaton rules, including some that arise as boundary
dynamics of two-dimensional solidification rules. Specifically, when started
from a random initial seed on an interval of length $L$, with probability
tending to one as $L\to\infty$, the evolution is a replicator. That is, a
region of space-time of density one is filled with a spatially and temporally
periodic pattern, punctuated by a finite set of other finite patterns repeated
at a fractal set of locations. On the other hand, the same rules exhibit
provably more complex evolution from some seeds, while from other seeds their
behavior is apparently chaotic. A principal tool is a new variant of
percolation theory, in the context of additive cellular automata from random
initial states.


title:
Bogoliubov excitation spectrum of an elongated condensate from
  quasi-one-dimensional to three-dimensional transition

abstract:
  The quasiparticle excitation spectra of a Bose gas trapped in a highly
anisotropic trap is studied with respect to varying total number of particles
by numerically solving the effective one-dimensional (1D) Gross-Pitaevskii (GP)
equation proposed recently by Mateo \textit{et al.}. We obtain the static
properties and Bogoliubov spectra of the system in the high energy domain. This
method is computationally efficient and highly accurate for a condensate system
undergoing a 1D to three-dimensional (3D) cigar-shaped transition, as is shown
through a comparison our results with both those calculated by the 3D-GP
equation and analytical results obtained in limiting cases. We identify the
applicable parameter space for the effective 1D-GP equation and find that this
equation fails to describe a system with large number of atoms. We also
identify that the description of the transition from 1D Bose-Einstein
condensate (BEC) to 3D cigar-shaped BEC using this equation is not smooth,
which highlights the fact that for a finite value of $a_\perp/a_s$ the junction
between the 1D and 3D crossover is not perfect.


title: Matrix Model Fixed Point of Noncommutative Phi-Four

abstract:
  In this article we exhibit explicitly the matrix model ($\theta=\infty$)
fixed point of phi-four theory on noncommutative spacetime with only two
noncommuting directions using the Wilson renormalization group recursion
formula and the 1/N expansion of the zero dimensional reduction and then
calculate the mass critical exponent $\nu$ and the anomalous dimension $\eta$
in various dimensions .

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


title:
All order alpha'-expansion of superstring trees from the Drinfeld
  associator

abstract:
  We derive a recursive formula for the alpha'-expansion of superstring tree
amplitudes involving any number N of massless open string states. String
corrections to Yang-Mills field theory are shown to enter through the Drinfeld
associator, a generating series for multiple zeta values. Our results apply for
any number of spacetime dimensions or supersymmetries and chosen helicity
configurations.


title: Interlayer Thermal Conductivity of Rubrene Measured by ac-Calorimetry

abstract:
  We have measured the interlayer thermal conductivity of crystals of the
organic semiconductor rubrene, using ac-calorimetry. Since ac-calorimetry is
most commonly used for measurements of the heat capacity, we include a
discussion of its extension for measurements of the transverse thermal
conductivity of thin crystals of poor thermal conductors, including the
limitations of the technique. For rubrene, we find that the interlayer thermal
conductivity, 0.7 mW/cm K, is several times smaller than the (previously
measured) in-layer value, but its temperature dependence indicates that the
interlayer mean free path is at least a few layers.


title: Mechanism of self-organization in point vortex system

abstract:
  A mechanism of the self-organization in an unbounded two-dimensional (2D)
point vortex system is discussed. A kinetic equation for the system with
positive and negative vortices is derived using the Klimontovich formalism.
Similar to the Fokker-Planck collision term, the obtained collision term
consists of a diffusion term and a drift term. It is revealed that the
mechanism for the self-organization in the 2D point vortex system at negative
absolute temperature is mainly provided by the drift term. Positive and
negative vortices are driven toward opposite directions respectively by the
drift term. As a result, well-known, two isolated clumps with positive and
negative vortices, respectively, are formed as an equilibrium distribution.
Regardless of the number of species of the vortices, either single- or
double-sign, it is found that the collision term has following physically good
properties: (i) When the system reaches a quasi-stationary state near the
thermal equilibrium state with negative absolute temperature, the sign of $d
\omega / d \psi$ is expected to be positive, where $\omega$ is the vorticity
and $\psi$ is the stream function. In this case, the diffusion term decreases
the mean field energy, while the drift term increases it. As a whole, the total
mean field energy is conserved. (ii) Similarly, the diffusion term increases
the Boltzmann entropy, while the drift term decreases it. As a whole, the total
entropy production rate is positive or zero ($H$ theorem), which ensures that
the system relaxes to the global thermal equilibrium state characterized by the
zero entropy production.


title:
Integral Monsky-Washnitzer cohomology and the overconvergent de
  Rham-Witt complex

abstract:
  In their paper which introduced Monsky-Washnitzer cohomology, Monsky and
Washnitzer described conditions under which the definition can be adapted to
give integral cohomology groups. It seems to be well-known among experts that
their construction always gives well-defined integral cohomology groups, but
this fact also does not appear to be explicitly written down anywhere. In this
paper, we prove that the integral Monsky-Washnitzer cohomology groups are
well-defined, for any nonsingular affine variety over a perfect field of
characteristic p. We then compare these cohomology groups with overconvergent
de Rham-Witt cohomology. It was shown earlier that if the affine variety has
small dimension relative to the characteristic of the ground field, then the
cohomology groups are isomorphic. We extend this result to show that for any
nonsingular affine variety, regardless of dimension, we have an isomorphism
between integral Monsky-Washnitzer cohomology and overconvergent de Rham-Witt
cohomology in degrees which are small relative to the characteristic.


title: Improved Capacity Approximations for Gaussian Relay Networks

abstract:
  Consider a Gaussian relay network where a number of sources communicate to a
destination with the help of several layers of relays. Recent work has shown
that a compress-and-forward based strategy at the relays can achieve the
capacity of this network within an additive gap. In this strategy, the relays
quantize their observations at the noise level and map it to a random Gaussian
codebook. The resultant capacity gap is independent of the SNR's of the
channels in the network but linear in the total number of nodes.
  In this paper, we show that if the relays quantize their signals at a
resolution decreasing with the number of nodes in the network, the additive gap
to capacity can be made logarithmic in the number of nodes for a class of
layered, time-varying wireless relay networks. This suggests that the
rule-of-thumb to quantize the received signals at the noise level used for
compress-and-forward in the current literature can be highly suboptimal.


title: Discord and information deficit in the XX chain

abstract:
  We examine the quantum correlations of spin pairs in the cyclic $XX$ spin 1/2
chain in a transverse field, through the analysis of the quantum discord, the
geometric discord and the information deficit. It is shown that while these
quantities provide the same qualitative information, being non-zero for all
temperatures and separations and exhibiting the same type of asymptotic
behavior for large temperatures or separations, important differences arise in
the minimizing local measurement that defines them. Whereas the quantum discord
prefers a spin measurement perpendicular to the transverse field, the geometric
discord and information deficit exhibit a perpendicular to parallel transition
as the field increases, which subsists at all temperatures and for all
separations. Moreover, it is shown that such transition signals the change from
a Bell state to an aligned separable state of the dominant eigenstate of the
reduced density matrix of the pair. Full exact results for both the
thermodynamic limit and the finite chain are provided, through the
Jordan-Wigner fermionization.


title:
On some class of differential-difference equations admitting Lax
  representation

abstract:
  This note is designed to show some classes of differential-difference
equations admitting Lax representation which generalize evolutionary equations
known in the literature.


title:
Optimal Partitioned-Interval Detection Binary Quantum Receiver with
  Practical Devices

abstract:
  Partitioned-interval detection binary quantum receiver with non-ideal devices
is theoretically analyzed. Using global optimized partition strategy,
relatively large gain over standard quantum limit (SQL) is obtained with small
partition number for certain mean photon number.


title: Symplectic cohomology and duality for the wrapped Fukaya category

abstract:
  Consider the wrapped Fukaya category W of a collection of exact Lagrangians
in a Liouville manifold. Under a non-degeneracy condition implying the
existence of enough Lagrangians, we show that natural geometric maps from the
Hochschild homology of W to symplectic cohomology and from symplectic
cohomology to the Hochschild cohomology of W are isomorphisms, in a manner
compatible with ring and module structures. This is a consequence of a more
general duality for the wrapped Fukaya category, which should be thought of as
a non-compact version of a Calabi-Yau structure. The new ingredients are: (1)
Fourier-Mukai theory for W via a wrapped version of holomorphic quilts, (2) new
geometric operations, coming from discs with two negative punctures and
arbitrary many positive punctures, (3) a generalization of the Cardy condition,
and (4) the use of homotopy units and A-infinity shuffle products to relate
non-degeneracy to a resolution of the diagonal.


title: Improvement of risk estimate on wind turbine tower buckled by hurricane

abstract:
  Wind is one of the important reasonable resources. However, wind turbine
towers are sure to be threatened by hurricanes. In this paper, method to
estimate the number of wind turbine towers that would be buckled by hurricanes
is discussed. Monte Carlo simulations show that our method is much better than
the previous one. Since in our method, the probability density function of the
buckling probability of a single turbine tower in a single hurricane is
obtained accurately but not from one approximated expression. The result in
this paper may be useful to the design and maintenance of wind farms.


title:
Rotation of Triangular Vortex Lattice in the Two-Band Superconductor
  MgB2

abstract:
  To identify the contributions of the multiband nature and the anisotropy of a
microscopic electronic structure to a macroscopic vortex lattice morphology, we
develop a method based on the Eilenberger theory near Hc2 combined with the
first-principles band calculation to estimate the stable vortex lattice
configuration. For a typical two-band superconductor MgB2, successive
transitions of vortex lattice orientation that have been observed recently by
small angle neutron scattering [Das, et al.: Phys. Rev. Lett. 108 (2012)
167001] are explained by the characteristic field-dependence of twoband
superconductivity and the competition of sixfold anisotropy between the sigma-
and pi-bands. The reentrant transition at low temperature reflects the Fermi
velocity anisotropy of the sigma-band.


title:
A Robust and Tunable Add-Drop Filter Using Whispering Gallery Mode
  Microtoroid Resonator

abstract:
  We fabricated and theoretically investigated an add-drop filter using an
on-chip whispering gallery mode (WGM) microtoroid resonator with ultra-high
quality factor (Q) side coupled to two taper fibers, forming the bus and drop
waveguides. The new device design incorporates silica side walls close to the
microresonators which not only enable placing the coupling fibers on the same
plane with respect to the microtoroid resonator but also provides mechanical
stability, leading to an add-drop filter with high drop efficiency and improved
robustness to environmental perturbations. We show that this new device can be
thermally tuned to drop desired wavelengths from the bus without significantly
affecting the drop efficiency, which is around 57%


title:
Suppressing the Errors due to Mode Mismatch for M-ary PSK Quantum
  Receivers by Photon-Number-Resolving Detector

abstract:
  A M-ary phase shift keying (PSK) quantum receiver consisting of displacement
operations, photon counting, and electrical feed-back adaptive measurements is
analyzed with a realistic model considering the effects of the sub-unity
quantum efficiency and the dark counts of single-photon detectors, as well as
the transmittance and the mode mismatch of beam splitters. Among these factors,
the mode mismatch has the greatest impact on the error probability of the
receiver with on-off detectors. The errors due to mode mismatch can be
suppressed effectively by using photon-number-resolving detectors (PNRD)
instead of on-off detectors.


title:
Cosmic opacity: cosmological-model-independent tests and their impacts
  on cosmic acceleration

abstract:
  With assumptions that the violation of the distance-duality (DD) relation
entirely arises from non-conservation of the photon number and the absorption
is frequency independent in the observed frequency range, we perform
cosmological-model-independent tests for the cosmic opacity. The observational
data include the largest Union2.1 SN Ia sample, which is taken for observed
$D_\mathrm{L}$, and galaxy cluster samples compiled by De Filippis {\it et al.}
and Bonamente {\it et al.}, which are responsible for providing observed
$D_\mathrm{A}$. Two parameterizations, $\tau(z)=2\epsilon z$ and
$\tau(z)=(1+z)^{2\epsilon}-1$ are adopted for the optical depth associated to
the cosmic absorption. We find that, an almost transparent universe is favored
by Filippis {\it et al.} sample but it is only marginally accommodated by
Bonomente {\it et al.} samples at 95.4% confidence level (C. L.) (even at 99.7%
C. L. when the $r<100 \mathrm{kpc}$-cut spherical $\beta$ model is considered).
Taking the possible cosmic absorption (in 68.3% C. L. range) constrained from
the model-independent tests into consideration, we correct the distance modulus
of SNe Ia and then use them to study their cosmological implications. The
constraints on the $\Lambda$CDM show that a decelerating expanding universe
with $\Omega_\Lambda=0$ is only allowed at 99.7% C. L. by observations when the
Bonamente {\it et al.} sample is considered. Therefore, our analysis suggests
that an accelerated cosmic expansion is still needed to account for the dimming
of SNe and the standard cosmological scenario remains to be supported by
current observations.


title:
Fast Clustering with Lower Bounds: No Customer too Far, No Shop too
  Small

abstract:
  We study the \LowerBoundedCenter (\lbc) problem, which is a clustering
problem that can be viewed as a variant of the \kCenter problem. In the \lbc
problem, we are given a set of points P in a metric space and a lower bound
\lambda, and the goal is to select a set C \subseteq P of centers and an
assignment that maps each point in P to a center of C such that each center of
C is assigned at least \lambda points. The price of an assignment is the
maximum distance between a point and the center it is assigned to, and the goal
is to find a set of centers and an assignment of minimum price. We give a
constant factor approximation algorithm for the \lbc problem that runs in O(n
\log n) time when the input points lie in the d-dimensional Euclidean space
R^d, where d is a constant. We also prove that this problem cannot be
approximated within a factor of 1.8-\epsilon unless P = \NP even if the input
points are points in the Euclidean plane R^2.


title: Single-qubit peration sharing with Bell and W product states

abstract:
  Two tripartite schemes are put forward with shared entanglements and LOCC for
sharing an operation on a remote target sate. The first scheme uses a Bell and
a symmetric W states as quantum channels, while the second replaces the
symmetric W state by an asymmetric one. Both schemes are treated and compared
from the aspects of quantum resource consumption, operation complexity,
classical resource consumption, success probability and efficiency. It is found
that, the latter scheme is better than the former one. Particularly, the
sharing can be achieved only probabilistically with the first scheme
deterministically with the second one.


title: Shared quantum control via sharing operation on remote single qutrit

abstract:
  Two qubit operation sharing schemes [J. Phys. B 44 (2011) 165508] are
generalized to qutrit ones. Operations to be shared are classified into three
different classes in terms of different probabilities (i.e, 1/3, 2/3 and 1).
For the latter two classes, ten and three restricted sets of operations are
found out, respectively. Moreover, the two generalized schemes are amply
compared from four aspects, namely, quantum and classical resource consumption,
necessaryoperation complexity, success probability and efficiency. It is found
that the second scheme is overall more optimal than the first one as far as
three restricted sets of operations are concerned.


title: Two Symmetric Properties of Mersenne Numbers and Fermat Numbers

abstract:
  Mersenne numbers and Fermat numbers are two hot and difficult issues in
number theory. This paper constructs a special group for every positive odd
number other than 1, and discovers an algorithm for determining the
multiplicative order of 2 modulo q for each positive odd number q. It is worth
mentioning that this paper discovers two symmetric properties of Mersenne
numbers and Fermat numbers.


title:
Quantum motion and level quantization of a skyrmion in a pinning
  potential in chiral magnets

abstract:
  A new topological excitation called skyrmion has been observed experimentally
in chiral magnets without spatial inversion symmetry. The dynamics of a
skyrmion is equivalent to an electron moving in a strong magnetic field. As a
skyrmion involves large number of spins, it is not clear whether there exist
observable quantum effects. In this work, we study the quantum dynamics of a
skyrmion in a pinning potential. Without a pinning potential, the skyrmion
performs cyclotron motion due to the strong emergent magnetic field originating
from the Berry phase of spins, and all skyrmions occupy the lowest Landau
level. Their wave functions are strongly localized in a region with radius less
than $1\ \AA$ when no driving force is applied. Thus in most circumstances, the
quantum effects of a skyrmion are weak. In the presence of a pinning potential,
the lowest Landau level for skyrmions is split into quantized levels,
characterized by the orbital moments. The transition between quantized levels
can be observed experimentally by microwave absorption measurements in low
temperature region. The quantum effects are more prominent for a skyrmion with
a small size, which can be realized in magnets with a large
Dzyaloshinskii-Moriya interaction.


title:
Nanomechanical Inverse Electromagnetically Induced Transparency and
  Confinement of Light in Normal modes

abstract:
  We demonstrate the existence of the phenomenon of the inverse
electromagnetically induced transparency (IEIT) in an opto mechanical system
consisting of a nanomechanical mirror placed in an optical cavity. We show that
two weak counter-propagating identical classical probe fields can be completely
absorbed by the system in the presence of a strong coupling field so that the
output probe fields are zero. The light is completely confined inside the
cavity and the energy of the incoming probe fields is shared between the cavity
field and creation of a coherent phonon and resides primarily in one of the
polariton modes. The energy can be extracted by a perturbation of the external
fields or by suddenly changing the $Q$ of the cavity.


title: Adaptive Software Radio Steganography

abstract:
  This paper presents an adaptable steganography (information hiding) method
for digital radio communication. Many radio steganography methods exist, but
most are defined at higher levels of the protocol stack and are thus protocol
dependent. In contrast, this method is defined at the physical layer, which
makes it widely applicable regardless of the protocols used at higher layers.
This approach is also adaptive; the covertness of the hidden channel is simple
to control via a single continuous parameter either manually or automatically.
Several variations are introduced, each with performance evaluated by
simulation. Results show this to be a feasible method with a reasonable
trade-off between performance and covertness.


title:
Quantum Decoherence of Charge Qubit coupled to Nonlinear Nanomechanical
  Resonator

abstract:
  When the nonlinearity of nanomechanical resonator is not negligible, the
quantum decoherence of charge qubit is studied analytically. Using nonlinear
Jaynes-Cummings model, one explores the possibility of being quantum data bus
for nonlinear nanomechanical resonator, the nonlinearity destroys the dynamical
quantum information-storage and maintains the revival of quantum coherence of
charge qubit. With the calculation of decoherence factor, we demonstrate the
influence of the nonlinearity of nanomechanical resonator on engineered
decoherence of charge qubit.


title: Plane Poiseuille flow through a porous medium - an analytical solution

abstract:
  This paper develops a closed-form, analytical expression for the Darcy
velocity of a Newtonian fluid flowing through a channel filled with a porous
medium, bound by rigid walls and driven by a constant pressure gradient. We
express the Darcy velocity as a Weierstrass elliptic function of the transverse
coordinate. It allows us to get analytical expressions for volume flux and the
rate of dissipation. The Weierstrass elliptic function is a doubly-periodic,
complex-valued function defined over the complex plane. It takes real values
only on certain segments in the complex plane. We show how to align the
transverse coordinate axis along these segments to ensure real values of Darcy
velocity. Lastly, we give an algorithm to generate velocity profile and compute
volume flux given the flow parameters.


title:
On Lagrangian Formulation for Spin (2,1,1) Massive Tensor Field on
  Minkowski Backgrounds

abstract:
  We derive the Lagrangian for a new model of a massive rank-4 tensor field
with generalized spin (2,1,1) in Minkowski spacetime of any dimension d>5, by
using dimensional reduction applied to a reducible gauge model of a massless
rank-4 tensor field with generalized spin (2,1,1) in Minkowski spacetime of
dimension d+1.


title: Three-tier CFTs from Frobenius algebras

abstract:
  These are lecture notes of a course given at the Summer School on Topology
and Field Theories held at the Centre for Mathematics of the University of
Notre Dame, Indiana, from May 29 to June 2, 2012. The idea of extending quantum
field theories to manifolds of lower dimension was first proposed by Dan Freed
in the nineties. In the case of conformal field theory (CFT), we are talking of
an extension of the Atiyah-Segal axioms, where one replaces the bordism
category of Riemann surfaces by a suitable bordism bicategory, whose ob jects
are points, whose morphisms are 1-manifolds, and whose 2-morphisms are pieces
of Riemann surface. There is a beautiful classification of full (rational) CFTs
due to Fuchs, Runkel and Schweigert, which roughly says the following. Fix a
chiral algebra A (= vertex algebra). Then the set of full cfts whose left and
right chiral algebras agree with A is classified by Frobenius algebras internal
to Rep(A). A famous example to which one can successfully apply this is the
case where the chiral algebra A is affine su(2) at level k, for some k in N. In
that case, the Frobenius algebras in Rep (A) are classified by A_n, D_n, E_6,
E_7, E_8, and so are the corresponding CFTs. Recently, Kapustin and Saulina
gave a conceptual interpretation of the FRS classification in terms of
3-dimensional Chern-Simons theory with defects. Those defects are also given by
Frobenius algebra ob ject in Rep(A). Inspired by the proposal of Kapustin and
Saulina, we will (partially) construct the three-tier CFT associated to a
Frobenius algebra object.


title:
Parametric normal forms for Bogdanov--Takens singularity; the
  generalized saddle-node case

abstract:
  We obtain a parametric normal form for any non-degenerate perturbation of the
generalized saddle-node case of Bogdanov--Takens singularity. Explicit formulas
are derived and greatly simplified for an efficient implementation in any
computer algebra system. A Maple program is prepared for an automatic
parametric normal form computation. A section is devoted to present some
practical formulas which avoid technical details of the paper.


title:
Government Solvency, Austerity and Fiscal Consolidation in the OECD: A
  Keynesian Appraisal of Transversality and No Ponzi Game Conditions

abstract:
  This paper investigates the relevance of the No-Ponzi game condition for
public debt (i.e. the public debt growth rate has to be lower than the real
interest rate, a necessary assumption for Ricardian equivalence) and of the
transversality condition for the GDP growth rate (i.e. the GDP growth rate has
to be lower than the real interest rate). First, on the unbalanced panel of 21
countries from 1961 to 2010 available in OECD database, those two conditions
were simultaneously validated only for 29% of the cases under examination.
Second, those two conditions were more frequent in the 1980s and the 1990s when
monetary policies were more restrictive. Third, in tune with the Keynesian
view, when the real interest rate is higher than the GDP growth, it corresponds
to 75% of the cases of the increases of the debt/GDP ratio but to only 43% of
the cases of the decreases of the debt/GDP ratio (fiscal consolidations).


title:
Distinguishing black holes from naked singularities through their
  accretion disk properties

abstract:
  We show that, in principle, a slowly evolving gravitationally collapsing
perfect fluid cloud can asymptotically settle to a static spherically symmetric
equilibrium configuration with a naked singularity at the center. We consider
one such asymptotic final configuration with a finite outer radius, and
construct a toy model in which it is matched to a Schwarzschild exterior
geometry. We examine the properties of circular orbits in this model. We then
investigate observational signatures of a thermal accretion disk in this
spacetime, comparing them with the signatures expected for a disk around a
black hole of the same mass. Several notable differences emerge. A disk around
the naked singularity is much more luminous than one around an equivalent black
hole. Also, the disk around the naked singularity has a spectrum with a high
frequency power law segment that carries a major fraction of the total
luminosity. Thus, at least some naked singularities can, in principle, be
distinguished observationally from black holes of the same mass. We discuss
possible implications of these results.


title: More properties of almost Cohen-Macaulay rings

abstract:
  Some interesting properties of almost Cohen-Macaulay rings are investigated
and a Serre type property connected with this class of rings is studied.


title:
OD-Characterization of Some Linear Groups Over Binary Field and Their
  Automorphism

abstract:
  The Gruenberg-Kegel graph ${\rm GK}(G)=(V_G, E_G)$ of a finite group $G$ is a
simple graph with vertex set $V_G=\pi(G)$, the set of all primes dividing the
order of $G$, and such that two distinct vertices $p$ and $q$ are joined by an
edge, $\{p, q\}\in E_G$, if $G$ contains an element of order $pq$. The degree
${\rm deg}_G(p)$ of a vertex $p\in V_G$ is the number of edges incident on $p$.
In the case when $\pi(G)=\{p_1, p_2,..., p_h\}$ with $p_1< p_2< ... < p_h$, we
consider the $h$-tuple $D(G)=({\rm deg}_G(p_1), {\rm deg}_G(p_2),..., {\rm
deg}_G(p_h))$, which is called the degree pattern of $G$. The group $G$ is
called $k$-fold OD-characterizable if there exist exactly $k$ non-isomorphic
groups $H$ satisfying condition $(|H|, D(H))=(|G|, D(G))$. Especially, a 1-fold
OD-characterizable group is simply called OD-characterizable. In this paper, we
first find the degree pattern of the projevtive special linear groups over
binary field $L_n(2)$ and among other results we prove that the simple groups
$L_{10}(2)$ and $L_{11}(2)$ are OD-characterizable (Theorem \ref{10-11}). It is
also shown that automorphism groups ${\rm Aut}(L_p(2))$ and ${\rm
Aut}(L_{p+1}(2))$, where $2^p-1$ is a Mersenne prime, are OD-characterizable
(Theorem \ref{auto}).


title: Representations and module-extensions of hom 3-Lie algebras

abstract:
  In this paper, we study the representations and module-extensions of hom
3-Lie algebras. We show that a linear map between hom 3-Lie algebras is a
morphism if and only if its graph is a hom 3-Lie subalgebra and show that the
derivations of a hom 3-Lie algebra is a Lie algebra. Derivation extension of
hom 3-Lie algebras are also studied as an application. Moreover, we introduce
the definition of $T_{\theta}$-extensions and $T^{*}_{\theta}$-extensions of
hom 3-Lie sub-algebras in terms of modules, provide the necessary and
sufficient conditions for $2k$-dimensional metric hom 3-Lie algebra to be
isomorphic to a $T^{*}_{\theta}$-extensions.


title: On the cohomology and extensions of first-class $n$-Lie superalgebras

abstract:
  An $n$-Lie superalgebra of parity 0 is called a first-class $n$-Lie
superalgebra. In this paper, we give the representation and cohomology for a
first-class $n$-Lie superalgebra and obtain a relation between extensions of a
first-class $n$-Lie superalgebra $\mathfrak{b}$ by an abelian one
$\mathfrak{a}$ and $Z^1(\mathfrak{b}, \mathfrak{a})_{\bar{0}}$. We also
introduce the notion of $T^*$-extensions of first-class $n$-Lie superalgebras
and prove that every finite-dimensional nilpotent metric first-class $n$-Lie
superalgebra $(\g,< ,>_{\g})$ over an algebraically closed field of
characteristic not 2 is isometric to a suitable $T^*$-extension.


title: Some characterizations of nilpotent $n$-Lie superalgebras

abstract:
  The paper studies nilpotent $n$-Lie superalgebras. More specifically
speaking, we first prove Engel's theorem for $n$-Lie superalgebras. Second, we
research some properties of nilpotent $n$-Lie superalgebras, Finally, we give
several sufficient conditions that an $n$-Lie superalgebra is nilpotent.


title:
Characterization of shift-variant pupil aberrations for wide
  field-of-view microscopy

abstract:
  We describe a simple and robust approach for characterizing the shift-variant
pupil aberrations of wide field-of-view microscopy systems. We derive the
location-dependent pupil transfer functions by first capturing multiple
intensity images at different defocus settings; a generalized pattern search
(GPS) algorithm is then applied to recover the complex pupil functions at ~350
different spatial locations over the entire field-of-view. Parameter fitting
transforms these pupil functions into accurate 2D aberration maps. We
demonstrate shift-variant aberration compensation by using an
information-preserving image deconvolution scheme over the entire
field-of-view. Such automated shift-variant pupil characterization will
facilitate new approaches of aberration correction for future gigapixel imaging
platforms.


title: Hom-Nijienhuis operator and $T$*-extension of Hom-Lie Superalgebras

abstract:
  In this paper, we study hom-Lie superalgebras. We give the definition of
hom-Nijienhuis operators of regualr hom-Lie superalgebras and show that the
deformation generated by a hom-Nijienhuis operator is trivial. Moreover, we
introduce the definition of $T^*$-extensions of Hom-Lie superalgebras and show
that $T^*$-extensions preserve many properties such as nilpotency, solvability
and decomposition in some sense. We also investigate the equivalence of
$T^*$-extensions.


title: Angle-sensitive pixel design for wavefront sensing

abstract:
  Conventional image sensors are only responsive to the intensity variation of
the incoming light wave. By encoding the wavefront information into the
balanced detection scheme, we demonstrate an image sensor pixel design that is
capable to detect both the local intensity and wavefront information
simultaneously. With the full compatibility to the CMOS fabrication process,
the proposed pixel design can benefit a variety of applications, including
phase microscopy, lensless imaging and machine vision.


title: Systems of quotients of Lie triple systems

abstract:
  In this paper, we introduce the notion of system of quotients of Lie triple
systems and investigate some properties which can be lifted from a Lie triple
system to its systems of quotients. We relate the notion of Lie triple system
of Martindale-like quotients with respect to a filter of ideals and the notion
of system of quotients, and prove that the system of quotients of a Lie triple
system is equivalent to the algebra of quotients of a Lie algebra in some
sense, and these allow us to construct the maximal system of quotients for
nondegenerate Lie triple systems.


title:
OD-Characterization of Certain Four Dimensional Linear Groups with
  Related Results Concerning Degree Patterns

abstract:
  The prime graph of a finite group $G$, which is denoted by ${\rm GK}(G)$, is
a simple graph whose vertex set is comprised of the prime divisors of $|G|$ and
two distinct prime divisors $p$ and $q$ are joined by an edge if and only if
there exists an element of order $pq$ in $G$. Let $p_1<p_2<...<p_k$ be all
prime divisors of $|G|$. Then the degree pattern of $G$ is defined as ${\rm
D}(G)=(deg_G(p_1), deg_G(p_2),..., deg_G(p_k))$, where $deg_G(p)$ signifies the
degree of the vertex $p$ in ${\rm GK}(G)$. A finite group $H$ is said to be
OD-characterizable if $G\cong H$ for every finite group $G$ such that $|G|=|H|$
and ${\rm D}(G)={\rm D}(H)$. The purpose of this article is threefold. First,
it finds sharp upper and lower bounds on $\vartheta(G)$, the sum of degrees of
all vertices in ${\rm GK}(G)$, for any finite group $G$ (Theorem 2.1). Second,
it provides the degree of vertices 2 and the characteristic $p$ of the base
field of any finite simple group of Lie type in their prime graphs
(Propositions 3.1-3.7). Third, it proves the linear groups $L_4(19)$,
$L_4(23)$, $L_4(27)$, $L_4(29)$, $L_4(31)$, $L_4(32)$ and $L_4(37)$ are
OD-characterizable (Theorem 4.2).


title:
Multiscale enhanced path sampling based on the Onsager-Machlup action:
  Application to a model polymer

abstract:
  We propose a novel path sampling method based on the Onsager-Machlup (OM)
action by generalizing the multiscale enhanced sampling (MSES) technique
suggested by Moritsugu and coworkers (J. Chem. Phys. 133, 224105 (2010)). The
basic idea of this method is that the system we want to study (for example,
some molecular system described by molecular mechanics) is coupled to a
coarse-grained (CG) system, which can move more quickly and computed more
efficiently than the original system. We simulate this combined system
(original + CG system) using (underdamped) Langevin dynamics where different
heat baths are coupled to the two systems. When the coupling is strong enough,
the original system is guided by the CG system, and able to sample the
configuration and path space more efficiency. We need to correct the bias
caused by the coupling, however, by employing the Hamiltonian replica exchange
where we prepare many path replica with different coupling strengths. As a
result, an unbiased path ensemble for the original system can be found in the
weakest coupling path ensemble. This strategy is easily implemented because a
weight for a path calculated by the OM action is formally the same as the
Boltzmann weight if we properly define the path "Hamiltonian". We apply this
method to a model polymer with Asakura-Oosawa interaction, and compare the
results with the conventional transition path sampling method.


title: Some Quantitative Characterizations of Certain Symplectic Groups

abstract:
  Given a finite group $G$, denote by ${\rm D}(G)$ the degree pattern of $G$
and by ${\rm OC}(G)$ the set of all order components of $G$. Denote by $h_{{\rm
OD}}(G)$ (resp. $h_{{\rm OC}}(G)$) the number of isomorphism classes of finite
groups $H$ satisfying conditions $|H|=|G|$ and ${\rm D}(H)={\rm D}(G)$ (resp.
${\rm OC}(H)={\rm OC}(G)$). A finite group $G$ is called OD-characterizable
(resp. OC-characterizable) if $h_{\rm OD}(G)=1$ (resp. $h_{\rm OC}(G)=1$). Let
$C=C_p(2)$ be a symplectic group over binary field, for which $2^p-1>7$ is a
Mersenne prime. The aim of this article is to prove that $h_{\rm
OD}(C)=1=h_{\rm OC}(C)$.


title: On feedback in Gaussian multi-hop networks

abstract:
  The study of feedback has been mostly limited to single-hop communication
settings. In this paper, we consider Gaussian networks where sources and
destinations can communicate with the help of intermediate relays over multiple
hops. We assume that links in the network can be bidirected providing
opportunities for feedback. We ask the following question: can the information
transfer in both directions of a link be critical to maximizing the end-to-end
communication rates in the network? Equivalently, could one of the directions
in each bidirected link (and more generally at least one of the links forming a
cycle) be shut down and the capacity of the network still be approximately
maintained? We show that in any arbitrary Gaussian network with bidirected
edges and cycles and unicast traffic, we can always identify a directed acyclic
subnetwork that approximately maintains the capacity of the original network.
For Gaussian networks with multiple-access and broadcast traffic, an acyclic
subnetwork is sufficient to achieve every rate point in the capacity region of
the original network, however, there may not be a single acyclic subnetwork
that maintains the whole capacity region. For networks with multicast and
multiple unicast traffic, on the other hand, bidirected information flow across
certain links can be critically needed to maximize the end-to-end capacity
region. These results can be regarded as generalizations of the conclusions
regarding the usefulness of feedback in various single-hop Gaussian settings
and can provide opportunities for simplifying operation in Gaussian multi-hop
networks.


title: SOA Embedded in BPM: A High Level View of Object Oriented Paradigm

abstract:
  The trends of design and development of information systems have undergone a
variety of ongoing phases and stages. These variations have been evolved due to
brisk changes in user requirements and business needs. To meet these
requirements and needs, a flexible and agile business solution was required to
come up with the latest business trends and styles. Another obstacle in agility
of information systems was typically different treatment of same diseases of
two patients: business processes and information services. After the emergence
of information technology, the business processes and information systems have
become counterparts. But these two business halves have been treated under
totally different standards. There is need to streamline the boundaries of
these both pillars that are equally sharing information system's burdens and
liabilities. In last decade, the object orientation has evolved into one of the
major solutions for modern business needs and now, SOA is the solution to shift
business on ranks of electronic platform. BPM is another modern business
solution that assists to regularize optimization of business processes. This
paper discusses how object orientation can be conformed to incorporate or embed
SOA in BPM for improved information systems.


title: SBVR vs OCL: A Comparative Analysis of Standards

abstract:
  In software modelling, the designers have to produce UML visual models with
software constraints. Similarly, in business modelling, designers have to model
business processes using business constraints (business rules). Constraints are
the key components in the skeleton of business or software models. A designer
has to write constraints to semantically compliment business models or UML
models and finally implementing the constraints into business processes or
source code. Business constraints/rules can be written using SBVR (Semantics of
Business Vocabulary and Rules) while OCL (Object Constraint Language) is the
well-known medium for writing software constraints. SBVR and OCL are two
significant standards from OMG. Both standards are principally different as
SBVR is typically used in business domains and OCL is employed to compliment
software models. However, we have identified a few similarities in both
standards that are interesting to study. In this paper, we have performed a
comparative analysis of both standards as we are looking for a mechanism for
automatic transformation of SBVR to OCL. The major emphasis of the study is to
highlight principal features of SBVR and OCL such as similarities, differences
and key parameters on which these both standards can work together.


title: The Metaplectic Group, the Symplectic Spinor and the Gouy Phase

abstract:
  In this paper we discuss a simplified approach to the symplectic Clifford
algebra, the symplectic Clifford group and the symplectic spinor by first
extending the Heisenberg algebra. We do this by adding a new idempotent element
to the algebra. It turns out that this element is the projection operator onto
the Dirac standard ket. When this algebra is transformed into the Fock algebra,
the corresponding idempotent is the projector onto the vacuum. These additional
elements give a very simple way to write down expressions for symplectic
spinors as elements of the symplectic Clifford algebra. When this algebra
structure is applied to an optical system we find a new way to understand the
Gouy effect. It is seen to arise from the covering group, which in this case is
the symplectic Clifford group, also known as the metaplectic group. We relate
our approach to that of Simon and Mukunda who have shown the relation of the
Gouy phase to the Berry phase.


title: Engineering entanglement for metrology with rotating matter waves

abstract:
  Entangled states of rotating, trapped ultracold bosons form a very promising
scenario for quantum metrology. In order to employ such states for metrology,
it is vital to understand their detailed form and the enhanced accuracy with
which they could measure phase, in this case generated through rotation. In
this work we study the rotation of ultracold bosons in an asymmetric trapping
potential beyond the lowest Landau level (LLL) approximation. We demonstrate
that whilst the LLL can identify reasonably the critical frequency for a
quantum phase transition and entangled state generation, it is vital to go
beyond the LLL to identify the details of the state and quantify the quantum
Fisher information (which bounds the accuracy of the phase measurement). We
thus identify a new parameter regime for useful entangled state generation,
amenable to experimental investigation.


title: Rotation Minimizing vector fields and frames in Riemannian manifolds

abstract:
  We prove that a normal vector field along a curve in R3 is rotation
minimizing (RM) if and only if it is parallel respect to the normal connection.
This allows us to generalize all the results of RM vectors and frames to curves
immersed in Riemannian manifolds.


title:
Extreme-value statistics of networks with inhibitory and excitatory
  couplings

abstract:
  Inspired by the importance of inhibitory and excitatory couplings in the
brain, we analyze the largest eigenvalue statistics of random networks
incorporating such features. We find that the largest real part of eigenvalues
of a network, which accounts for the stability of an underlying system,
decreases linearly as a function of inhibitory connection probability up to a
particular threshold value, after which it exhibits rich behaviors with the
distribution manifesting generalized extreme value statistics. Fluctuations in
the largest eigenvalue remain somewhat robust against an increase in system
size but reflect a strong dependence on the number of connections, indicating
that systems having more interactions among its constituents are likely to be
more unstable.


title:
Parabolic Harnack inequality of viscosity solutions on Riemannian
  manifolds

abstract:
  We consider viscosity solutions to nonlinear uniformly parabolic equations in
nondivergence form on a Riemannian manifold $M$, with the sectional curvature
bounded from below by $-\kappa$ for $\kappa\geq 0$. In the elliptic case, Wang
and Zhang \cite{WZ} recently extended the results of \cite{Ca} to nonlinear
elliptic equations in nondivergence form on such $M$, where they obtained the
Harnack inequality for classical solutions. We establish the Harnack inequality
for nonnegative {\it viscosity solutions} to nonlinear uniformly {\it parabolic
equations} in nondivergence form on $M$.
  The Harnack inequality of nonnegative viscosity solutions to the elliptic
equations is also proved.


title:
How to estimate the number of self-avoiding walks over 10^100? Use
  random walks

abstract:
  Counting the number of N-step self-avoiding walks (SAWs) on a lattice is one
of the most difficult problems of enumerative combinatorics. Once we give up
calculating the exact number of them, however, we have a chance to apply
powerful computational methods of statistical mechanics to this problem. In
this paper, we develop a statistical enumeration method for SAWs using the
multicanonical Monte Carlo method. A key part of this method is to expand the
configuration space of SAWs to random walks, the exact number of which is
known. Using this method, we estimate a number of N-step SAWs on a square
lattice, c_N, up to N=256. The value of c_256 is 5.6(1)*10^108 (the number in
the parentheses is the statistical error of the last digit) and this is larger
than one googol (10^100).


title: A note on non-parametric Bayesian estimation for Poisson point processes

abstract:
  We derive the posterior contraction rate for non-parametric Bayesian
estimation of the intensity function of a Poisson point process.


title:
Volterra calculus, local equivariant family index theorem and
  equivariant eta forms

abstract:
  In this paper, we give proofs of the family index formula and the equivariant
family index formula by the Greiner's approach to heat kernel asymptotics. We
compute equivariant family JLO characters. We also define the equivariant eta
form and give a proof of its regularity.


title: Web graph compression with fast access

abstract:
  In recent years studying the content of the World Wide Web became a very
important yet rather difficult task. There is a need for a compression
technique that would allow a web graph representation to be put into the memory
while maintaining random access time competitive to the time needed to access
uncompressed web graph on a hard drive.
  There are already available techniques that accomplish this task, but there
is still room for improvements and this thesis attempts to prove it. It
includes a comparison of two methods contained in state of art of this field
(BV and k2partitioned) to two already implemented algorithms (rewritten,
however, in C++ programming language to maximize speed and resource management
efficiency), which are LM and 2D, and introduces the new variant of the latter
one, called 2D stripes.
  This thesis serves as well as a proof of concept. The final considerations
show positive and negative aspects of all presented methods, expose the
feasibility of the new variant as well as indicate future direction for
development.


title:
Neutron Energy Spectrum Measurements with a Compact Liquid Scintillation
  Detector on EAST

abstract:
  A neutron detector based on EJ301 liquid scintillator has been employed at
EAST to measure the neutron energy spectrum for D-D fusion plasma. The detector
was carefully characterized in different quasi-monoenergetic neutron fields
generated by a 4.5 MV Van de Graaff accelerator. In recent experimental
campaigns, due to the low neutron yield at EAST, a new shielding device was
designed and located as close as possible to the tokamak to enhance the count
rate of the spectrometer. The fluence of neutrons and gamma-rays was measured
with the liquid neutron spectrometer and was consistent with 3He proportional
counter and NaI (Tl) gamma-ray spectrometer measurements. Plasma ion
temperature values were deduced from the neutron spectrum in discharges with
lower hybrid wave injection and ion cyclotron resonance heating. Scattered
neutron spectra were simulated by the Monte Carlo transport Code, and they were
well verified by the pulse height measurements at low energies.


title: Noise of a single-electron emitter

abstract:
  I analyze the correlation function of currents generated by the periodically
driven quantum capacitor emitting single electrons and holes into the chiral
waveguide. I compare adiabatic and non-adiabatic, transient working regimes of
a single-electron emitter and find the striking difference between the
correlation functions in two regimes. Quite generally for the system driven
with frequency $\Omega$ the correlation function depends on two frequencies,
$\omega$ and $\ell \Omega - \omega$, where $\ell$ is an integer. For the
emitter driven non-adiabatically the correlation functions for different $\ell$
are similar and almost symmetric in $\omega$. While in the case of adiabatic
drive the correlation functions for $\ell \ne 0$ are highly asymmetric in
$\omega$ and exceed significantly the one corresponding to $\ell = 0$. Under
optimal operating conditions the correlation function for odd $\ell$ is zero.


title:
The first Hi-GAL observations of the outer Galaxy: a look to star
  formation in the third Galactic quadrant in the longitude range 216.5 < l <
  225.5

abstract:
  We present the first Herschel PACS and SPIRE photometric observations in a
portion of the outer Galaxy ($216.5^{\circ} \lesssim \ell \lesssim
225.5^{\circ}$ and $-2^{\circ} \lesssim b \lesssim 0^{\circ}$) as a part of the
Hi-GAL survey. The maps between 70 and 500 $\mu$m, the derived column density
and temperature maps, and the compact source catalog are presented. NANTEN
CO(1-0) line observations are used to derive cloud kinematics and distances, so
that we can estimate distance-dependent physical parameters of the compact
sources (cores and clumps) having a reliable spectral energy distribution, that
we separate in 255 proto-stellar and 688 starless. Both typologies are found in
association with all the distance components observed in the field, up to $\sim
5.8$ kpc, testifying the presence of star formation beyond the Perseus arm at
these longitudes. Selecting the starless gravitationally bound sources we
identify 590 pre-stellar candidates. Several sources of both proto- and
pre-stellar nature are found to exceed the minimum requirement for being
compatible with massive star formation, based on the mass-radius relation. For
the pre-stellar sources belonging to the Local arm ($d\lesssim1.5$ kpc) we
study the mass function, whose high-mass end shows a power-law $N(\log M)
\propto M^{-1.0 \pm 0.2}$. Finally, we use a luminosity vs mass diagram to
infer the evolutionary status of the sources, finding that most of the
proto-stellar are in the early accretion phase (with some cases compatible with
a Class I stage), while for pre-stellar sources, in general, accretion has not
started yet.


title: Constant conditional entropy and related hypotheses

abstract:
  Constant entropy rate (conditional entropies must remain constant as the
sequence length increases) and uniform information density (conditional
probabilities must remain constant as the sequence length increases) are two
information theoretic principles that are argued to underlie a wide range of
linguistic phenomena. Here we revise the predictions of these principles to the
light of Hilberg's law on the scaling of conditional entropy in language and
related laws. We show that constant entropy rate (CER) and two interpretations
for uniform information density (UID), full UID and strong UID, are
inconsistent with these laws. Strong UID implies CER but the reverse is not
true. Full UID, a particular case of UID, leads to costly uncorrelated
sequences that are totally unrealistic. We conclude that CER and its particular
cases are incomplete hypotheses about the scaling of conditional entropies.

categories: cond-mat.stat-mech cs.CL cs.IT math.IT physics.data-an


title: Geodesics with negative energy in the ergosphere of rotating black holes

abstract:
  It is shown that the geodesics with negative energy for rotating black holes
cannot originate or terminate inside the ergosphere. Their length is always
finite and this leads to conclusion that they must originate and terminate
inside the gravitational radius of the ergosphere.


title:
Superflares on Solar-Type Stars Observed with Kepler II. Photometric
  Variability of Superflare-Generating Stars : A Signature of Stellar Rotation
  and Starspots

abstract:
  We performed simple spot-model calculations for quasi-periodic brightness
variations of solar-type stars showing superflares, by using Kepler photometric
data. Most of superflare stars show quasi-periodic brightness modulations with
the typical period of one to a few tens of days. Our results indicate that
these brightness variations of superflare stars can be explained by the
rotation of the star with fairly large starspots. Using the result of the
period analysis, we investigated the relation between the energy and frequency
of superflares and the rotation period. Stars with relatively slower rotation
rates can still produce flares that are as energetic as those of more rapidly
rotating stars, although the average flare frequency is lower for more slowly
rotating stars. We found that the energy of superflares are related to the
total coverage of starspots. The correlation between the spot coverage and the
flare energy in superflares is similar to that in solar flares. These results
suggest that the energy of superflares can be explained by the magnetic energy
stored around starspots.


title:
Odd-even effect of quantum discord and quantum phase transitions in the
  S=1/2 spin ladder with ring exchange

abstract:
  The singularity of quantum correlations, such as quantum entanglement(QE) and
quantum discord(QD), has been widely regarded as a valuable indicator for
quantum phase transition(QPT) in low-dimensional quantum systems. In this
paper, for a spin ladder system with ring exchange, we find that the
singularity of QD (or QE) could not indicate the critical points of the system.
Instead, the QD shows a novel odd-even effect in some phases, which can be used
to detect the phase boundary points. The size effect is related to the symmetry
breaking of the ladder.


title: Transition radiation from electrons with orbital angular momentum

abstract:
  Several experimental groups have recently obtained the so called vortex
electrons (electrons with orbital angular momentum (OAM) of l = 100h) with
energies of 300 keV. The gyromagnetic ratio of such electrons becomes
proportional to the OAM value, which leads to the corresponding increase of the
electron magnetic moment. In this paper we investigate the transition radiation
from the "charge + magnetic moment" system using the theory of classical
electrodynamics. The circular polarization of optical transition radiation
amounts up to 70%, which allows to use this effect for the independent
measurement of the electron orbital momentum value.

categories: physics.acc-ph hep-ph physics.optics quant-ph


title:
Phase transition in the economically modeled growth of a cellular
  nervous system

abstract:
  Spatially-embedded complex networks, such as nervous systems, the Internet
and transportation networks, generally have non-trivial topological patterns of
connections combined with nearly minimal wiring costs. However the growth rules
shaping these economical trade-offs between cost and topology are not well
understood. Here we study the cellular nervous system of the nematode worm C.
elegans, together with information on the birth times of neurons and on their
spatial locations. We find that the growth of this network undergoes a
transition from an accelerated to a constant increase in the number of links
(synaptic connections) as a function of the number of nodes (neurons). The time
of this phase transition coincides closely with the observed moment of
hatching, when development switches metamorphically from oval to larval stages.
We use graph analysis and generative modelling to show that the transition
between different growth regimes, as well as its coincidence with the moment of
hatching, can be explained by a dynamic economical model which incorporates a
trade-off between topology and cost that is continuously negotiated and
re-negotiated over developmental time. As the body of the animal progressively
elongates, the cost of longer distance connections is increasingly penalised.
This growth process regenerates many aspects of the adult nervous system's
organization, including the neuronal membership of anatomically pre-defined
ganglia. We expect that similar economical principles can be found in the
development of other biological or man-made spatially-embedded complex systems.


title: Large-Area Aiming Synthesis of WSe2 Monolayers

abstract:
  The monolayer transition metal dichalcogenides have recently attracted much
attention owing to their potential in valleytronics, flexible and low-power
electronics and optoelectronic devices. Recent reports have demonstrated the
growth of large-size 2-dimensional MoS2 layers by the sulfurization of
molybdenum oxides. However, the growth of transition metal selenide monolayer
has still been a challenge. Here we report that the introduction of hydrogen in
the reaction chamber helps to activate the selenization of WO3, where
large-size WSe2 monolayer flakes or thin films can be successfully grown.


title:
Asymptotically minimax empirical Bayes estimation of a sparse normal
  mean vector

abstract:
  For the important classical problem of inference on a sparse high-dimensional
normal mean vector, we propose a novel empirical Bayes model that admits a
posterior distribution with desirable properties under mild conditions. In
particular, our empirical Bayes posterior distribution concentrates on balls,
centered at the true mean vector, with squared radius proportional to the
minimax rate, and its posterior mean is an asymptotically minimax estimator. We
also show that, asymptotically, the support of our empirical Bayes posterior
has roughly the same effective dimension as the true sparse mean vector.
Simulation from our empirical Bayes posterior is straightforward, and our
numerical results demonstrate the quality of our method compared to others
having similar large-sample properties.


title: Lambda Determinants

abstract:
  In this paper we prove a homogenous generalization of the lambda determinant
formula of Mills, Robbins and Rumsey. In our formula the parameters depends on
two indices. Our result also extends a recent formula of Di Francesco.


title:
Solution to the measurement problem within linear, unitary, no collapse,
  no particle quantum mechanics

abstract:
  The measurement problem is to explain why a system which is in a linear
combination of states appears, upon measurement, to be in just one of those
states. The solution given here is to first show that if one assumes linear,
unitary, no collapse, no particle quantum mechanics, the different versions of
reality are completely isolated from each other. This then implies only the
eigenstates appropriate to the measurement setup will be perceived. In a
Stern-Gerlach experiment, for example, only spin up or spin down will be
perceived, but never a combination of the two.


title:
Instabilities, solitons, and rogue waves in PT-coupled nonlinear
  waveguides

abstract:
  We considered the modulational instability of continuous-wave backgrounds,
and the related generation and evolution of deterministic rogue waves in the
recently introduced parity-time (PT)-symmetric system of linearly-coupled
nonlinear Schr\"odinger equations, which describes a Kerr-nonlinear optical
coupler with mutually balanced gain and loss in its cores. Besides the linear
coupling, the overlapping cores are coupled through cross-phase-modulation term
too. While the rogue waves, built according to the pattern of the Peregrine
soliton, are (quite naturally) unstable, we demonstrate that the focusing
cross-phase-modulation interaction results in their partial stabilization. For
PT-symmetric and antisymmetric bright solitons, the stability region is found
too, in an exact analytical form, and verified by means of direct simulations.


title:
Timing and Interstellar Scattering of Thirty-five Distant Pulsars
  Discovered in the PALFA Survey

abstract:
  We have made extensive observations of 35 distant slow (non-recycled) pulsars
discovered in the ongoing Arecibo PALFA pulsar survey. Timing observations of
these pulsars over several years at Arecibo Observatory and Jodrell Bank
Observatory have yielded high-precision positions and measurements of rotation
properties. Despite being a relatively distant population, these pulsars have
properties that mirror those of the previously known pulsar population. Many of
the sources exhibit timing noise, and one underwent a small glitch. We have
used multifrequency data to measure the interstellar scattering properties of
these pulsars. We find scattering to be higher than predicted along some lines
of sight, particularly in the Cygnus region. Lastly, we present XMM-Newton and
Chandra observations of the youngest and most energetic of the pulsars,
J1856+0245, which has previously been associated with the GeV-TeV pulsar wind
nebula HESS J1857+026.


title: A one-dimensional tunable magnetic metamaterial

abstract:
  We present experimental data on a one-dimensional superconducting
metamaterial that is tunable over a broad frequency band. The basic building
block of this magnetic thin-film medium is a single-junction (rf-)
superconducting quantum interference device (SQUID). Due to the nonlinear
inductance of such an element, its resonance frequency is tunable in situ by
applying a dc magnetic field. We demonstrate that this results in tunable
effective parameters of our metamaterial consisting of 54 SQUIDs. In order to
obtain the effective magnetic permeability from the measured data, we employ a
technique that uses only the complex transmission coefficient S21.


title:
Balloon-borne hard X-ray astronomy with PoGOLite: Opening a new window
  on the universe

abstract:
  High energy polarization can be an indication of geometry, orientation, and
other physical phenomena for a variety of sources, but has heretofore been a
virtually unmeasured phenomenon. PoGOLite is a balloon-borne instrument
intended to measure the polarization of X-rays between 25 and 100 keV. The
pathfinder version of the instrument is scheduled to be launched from northern
Sweden in summer 2013. The primary targets are the Crab pulsar and nebula and
Cygnus X-1.


title: NP-Hardness of Speed Scaling with a Sleep State

abstract:
  A modern processor can dynamically set it's speed while it's active, and can
make a transition to sleep state when required. When the processor is operating
at a speed $s$, the energy consumed per unit time is given by a convex power
function $P(s)$ having the property that $P(0) > 0$ and $P"(s) > 0$ for all
values of $s$. Moreover, $C > 0$ units of energy is required to make a
transition from the sleep state to the active state. The jobs are specified by
their arrival time, deadline and the processing volume.
  We consider a scheduling problem, called speed scaling with sleep state,
where each job has to be scheduled within their arrival time and deadline, and
the goal is to minimize the total energy consumption required to process these
jobs. Albers et. al. proved the NP-hardness of this problem by reducing an
instance of an NP-hard partition problem to an instance of this scheduling
problem. The instance of this scheduling problem consists of the arrival time,
the deadline and the processing volume for each of the jobs, in addition to $P$
and $C$. Since $P$ and $C$ depend on the instance of the partition problem,
this proof of the NP-hardness of the speed scaling with sleep state problem
doesn't remain valid when $P$ and $C$ are fixed. In this paper, we prove that
the speed scaling with sleep state problem remains NP-hard for any fixed
positive number $C$ and convex $P$ satisfying $P(0) > 0$ and $P"(s) > 0$ for
all values of $s$.


title:
Two Super-Earths Orbiting the Solar Analogue HD41248 on the edge of a
  7:5 Mean Motion Resonance

abstract:
  The number of multi-planet systems known to be orbiting their host stars with
orbital periods that place them in mean motion resonances is growing. For the
most part, these systems are in first-order resonances and dynamical studies
have focused their efforts towards understanding the origin and evolution of
such dynamically resonant commensurabilities. We report here the discovery of
two super-Earths that are close to a second-order dynamical resonance, orbiting
the metal-poor ([Fe/H]=-0.43 dex) and inactive G2V star HD41248. We analysed 62
HARPS archival radial velocities for this star, that until now, had exhibited
no evidence for planetary companions. Using our new Bayesian Doppler signal
detection algorithm, we find two significant signals in the data, with periods
of 18.357 days and 25.648 days, indicating they could be part of a 7:5
second-order mean motion resonance. Both semi-amplitudes are below 3m/s and the
minimum masses of the pair are 12.3 and 8.6Mearth, respectively. Our
simulations found that apsidal alignment stabilizes the system, and even though
libration of the resonant angles was not seen, the system is affected by the
presence of the resonance and could yet occupy the 7:5 commensurability, which
would be the first planetary configuration in such a dynamical resonance. Given
the multitude of low-mass multiplanet systems that will be discovered in the
coming years, we expect more of these second-order resonant configurations will
emerge from the data, highlighting the need for a better understanding of the
dynamical interactions between forming planetesimals.


title:
Asymptotic FRESH Properizer for Block Processing of Improper-Complex
  Second-Order Cyclostationary Random Processes

abstract:
  In this paper, the block processing of a discrete-time (DT) improper-complex
second-order cyclostationary (SOCS) random process is considered. In
particular, it is of interest to find a pre-processing operation that enables
computationally efficient near-optimal post-processing. An invertible
linear-conjugate linear (LCL) operator named the DT FREquency Shift (FRESH)
properizer is first proposed. It is shown that the DT FRESH properizer converts
a DT improper-complex SOCS random process input to an equivalent DT
proper-complex SOCS random process output by utilizing the information only
about the cycle period of the input. An invertible LCL block processing
operator named the asymptotic FRESH properizer is then proposed that mimics the
operation of the DT FRESH properizer but processes a finite number of
consecutive samples of a DT improper-complex SOCS random process. It is shown
that the output of the asymptotic FRESH properizer is not proper but
asymptotically proper and that its frequency-domain covariance matrix converges
to a highly-structured block matrix with diagonal blocks as the block size
tends to infinity. Two representative estimation and detection problems are
presented to demonstrate that asymptotically optimal low-complexity
post-processors can be easily designed by exploiting these asymptotic
second-order properties of the output of the asymptotic FRESH properizer.


title:
Varadhan Estimates for rough differential equations driven by fractional
  Brownian motions

abstract:
  In this work we study rough differential equations driven by a fractional
Brownian motion with Hurst parameter H>1/4 and establish Varadhan's small time
estimates for the density of solutions of such equations under Hormander's type
conditions.


title:
Optimal energy scaling for a shear experiment in single-crystal
  plasticity with cross-hardening

abstract:
  Consideration is given to a non-convex variational model for a shear
experiment in the framework of single-crystal linearised plasticity with
infinite cross-hardening. The rectangular shear sample is clamped at each end,
and is subjected to a prescribed horizontal or diagonal shear, modelled by an
appropriate hard Dirichlet condition. We ask: how much energy is required to
impose such a shear, and how does it depend on the aspect ratio? Assuming that
just two slip systems are active, we show that there is a critical aspect
ratio, above which the energy is strictly positive, and below which it is zero.
Furthermore, in the respective regimes determined by the aspect ratio, we prove
energy scaling bounds, expressed in terms of the amount of prescribed shear.


title: About presentations of braid groups and their generalizations

abstract:
  In the paper we give a survey of rather new notions and results which
generalize classical ones in the theory of braids. Among such notions are
various inverse monoids of partial braids. We also observe presentations
different from standard Artin presentation for generalizations of braids.
Namely, we consider presentations with small number of generators, Sergiescu
graph-presentations and Birman-Ko-Lee presentation. The work of V.V.Chaynikov
on the word and conjugacy problems for the singular braid monoid in
Birman-Ko-Lee generators is described as well.