title: Discovery of eight lensing clusters of galaxies

abstract:
  Clusters of galaxies have a huge mass which can act as gravitational lenses.
Galaxies behind clusters can be distorted to form arcs in images by the lenses.
Herein a search was done for giant lensed arcs by galaxy clusters using the
SDSS data. By visually inspecting SDSS images of newly identified clusters in
the SDSS DR8 and Stripe 82 data, we discover 8 strong lensing clusters together
with additional 3 probable and 6 possible cases. The lensed arcs show bluer
colors than the member galaxies of clusters. The masses and optical
luminosities of galaxy clusters interior to the arcs are calculated, and the
mass-to-light ratios are found to be in the range of a few tens of
M_Solar/L_Solar, consistent with the distribution of previously known lensing
clusters.


title: Disk entanglement entropy for a Maxwell field

abstract:
  In three dimensions, the pure Maxwell theory with compact U(1) gauge group is
dual to a free compact scalar, and flows from the Maxwell theory with
non-compact gauge group in the ultraviolet to a non-compact free massless
scalar theory in the infrared. We compute the vacuum disk entanglement entropy
all along this flow, and show that the renormalized entropy F(r) decreases
monotonically with the radius r as predicted by the F-theorem, interpolating
between a logarithmic growth for small r (matching the behavior of the S^3 free
energy) and a constant at large r (equal to the free energy of the conformal
scalar). The calculation is carried out by the replica trick, employing the
scalar formulation of the theory. The Renyi entropies for n>1 are given by a
sum over winding sectors, leading to a Riemann-Siegel theta function. The
extrapolation to n=1, to obtain the von Neumann entropy, is done by analytic
continuation in the large- and small-r limits and by a numerical extrapolation
method at intermediate values. We also compute the leading contribution to the
renormalized entanglement entropy of the compact free scalar in higher
dimensions. Finally, we point out some interesting features of the reduced
density matrix for the compact scalar, and its relation to that for the
non-compact theory.


title: Variable selection for BART: An application to gene regulation

abstract:
  We consider the task of discovering gene regulatory networks, which are
defined as sets of genes and the corresponding transcription factors which
regulate their expression levels. This can be viewed as a variable selection
problem, potentially with high dimensionality. Variable selection is especially
challenging in high-dimensional settings, where it is difficult to detect
subtle individual effects and interactions between predictors. Bayesian
Additive Regression Trees [BART, Ann. Appl. Stat. 4 (2010) 266-298] provides a
novel nonparametric alternative to parametric regression approaches, such as
the lasso or stepwise regression, especially when the number of relevant
predictors is sparse relative to the total number of available predictors and
the fundamental relationships are nonlinear. We develop a principled
permutation-based inferential approach for determining when the effect of a
selected predictor is likely to be real. Going further, we adapt the BART
procedure to incorporate informed prior information about variable importance.
We present simulations demonstrating that our method compares favorably to
existing parametric and nonparametric procedures in a variety of data settings.
To demonstrate the potential of our approach in a biological context, we apply
it to the task of inferring the gene regulatory network in yeast (Saccharomyces
cerevisiae). We find that our BART-based procedure is best able to recover the
subset of covariates with the largest signal compared to other variable
selection methods. The methods developed in this work are readily available in
the R package bartMachine.


title:
Contribution of Halides in CsX (X=Cl, Br and I) Thin Films on the
  formation of SPR peaks

abstract:
  This manuscript describes the evolution of grain structures in Cesium Halide
films which results in appearance of Surface Plasmon Resonance (SPR) peaks in
UV-visible absorption spectra. Thin films of Cesium Halide grown by thermal
evaporation are polycrystalline in nature with large irregular tightly packed
grains with sharp grain boundaries. With time these grain boundaries recede to
become smaller and spherical in shape in order to minimize the free surface
energy of the system. The process is also assisted by the presence of point
defects/color centers in Cesium Halide films. These defects which appear due to
the absence of massive halide atoms from the lattice results in residual
tensile stress within the lattice which results in defect diffusion. The
defects migrate outwards towards the grain surface giving rise to Cesium metal
clusters. The lattice mismatch appearing between the lattices at the grain
boundary and the bulk giving rise to Core-shell structure further contributes
to grain division. Along with this volume diffusion, a surface diffusion of
Cesium takes place towards sites of faceted grain boundaries resulting in a
necking phenomenon, appearing like bridges between the daughter Cesium Halide
grains (grains appearing due to division of a single grain). Breaking away of
the daughter Cesium Halide grains results in nano-rods that contribute to the
SPR peak seen.


title:
A study of transport suppression in an undoped AlGaAs/GaAs quantum dot
  single-electron transistor

abstract:
  We report a study of transport blockade features in a quantum dot
single-electron transistor, based on an undoped AlGaAs/GaAs heterostructure. We
observe suppression of transport through the ground state of the dot, as well
as negative differential conductance at finite source-drain bias. The
temperature and magnetic field dependence of these features indicate the
couplings between the leads and the quantum dot states are suppressed. We
attribute this to two possible mechanisms: spin effects which determine whether
a particular charge transition is allowed based on the change in total spin,
and the interference effects that arise from coherent tunneling of electrons in
the dot.


title: Electromagnetic wave propagation in random waveguides

abstract:
  We study long range propagation of electromagnetic waves in random waveguides
with rectangular cross-section and perfectly conducting boundaries. The
waveguide is filled with an isotropic linear dielectric material, with randomly
fluctuating electric permittivity. The fluctuations are weak, but they cause
significant cumulative scattering over long distances of propagation of the
waves. We decompose the wave field in propagating and evanescent transverse
electric and magnetic modes with random amplitudes that encode the cumulative
scattering effects. They satisfy a coupled system of stochastic differential
equations driven by the random fluctuations of the electric permittivity. We
analyze the solution of this system with the diffusion approximation theorem,
under the assumption that the fluctuations decorrelate rapidly in the range
direction. The result is a detailed characterization of the transport of energy
in the waveguide, the loss of coherence of the modes and the depolarization of
the waves due to cumulative scattering.


title:
Dictionary Learning and Sparse Coding on Grassmann Manifolds: An
  Extrinsic Solution

abstract:
  Recent advances in computer vision and machine learning suggest that a wide
range of problems can be addressed more appropriately by considering
non-Euclidean geometry. In this paper we explore sparse dictionary learning
over the space of linear subspaces, which form Riemannian structures known as
Grassmann manifolds. To this end, we propose to embed Grassmann manifolds into
the space of symmetric matrices by an isometric mapping, which enables us to
devise a closed-form solution for updating a Grassmann dictionary, atom by
atom. Furthermore, to handle non-linearity in data, we propose a kernelised
version of the dictionary learning algorithm. Experiments on several
classification tasks (face recognition, action recognition, dynamic texture
classification) show that the proposed approach achieves considerable
improvements in discrimination accuracy, in comparison to state-of-the-art
methods such as kernelised Affine Hull Method and graph-embedding Grassmann
discriminant analysis.


title:
Embeddings of $P(\omega)/{\rm Fin}$ into Borel Equivalence Relations
  between $\ell_p$ and $\ell_q$

abstract:
  We prove that, for $1 \le p<q<\infty$, the partially ordered set
$P(\omega)/{\rm Fin}$ can be embedded into Borel equivalence relations between
$\mathbb{R}^\omega/\ell_p$ and $\mathbb{R}^\omega/\ell_q$. Since there is an
antichain of size continuum in $P(\omega)/{\rm Fin}$, therefore there are
continuum many incomparable Borel equivalence relations between
$\mathbb{R}^\omega/\ell_p$ and $\mathbb{R}^\omega/\ell_q$.


title: A possible connection between Fast Radio Bursts and Gamma-Ray Bursts

abstract:
  The physical nature of Fast Radio Bursts (FRBs), a new type of cosmological
transients discovered recently, is not known. It has been suggested that FRBs
can be produced when a spinning supra-massive neutron star loses centrifugal
support and collapses to a black hole. Here we suggest that such implosions can
happen in supra-massive neutron stars shortly (hundreds to thousands of
seconds) after their births, and an observational signature of such implosions
may have been observed in the X-ray afterglows of some long and short gamma-ray
bursts (GRBs). Within this picture, a small fraction of FRBs would be
physically connected to GRBs. We discuss possible multi-wavelength
electromagnetic signals and gravitational wave signals that might be associated
with FRBs, and propose an observational campaign to unveil the physical nature
of FRBs. In particular, we strongly encourage a rapid radio follow-up
observation of GRBs starting from 100 s after GRB triggers.


title: Traffic Control for Network Protection Against Spreading Processes

abstract:
  Epidemic outbreaks in human populations are facilitated by the underlying
transportation network. We consider strategies for containing a viral spreading
process by optimally allocating a limited budget to three types of protection
resources: (i) Traffic control resources, (ii), preventative resources and
(iii) corrective resources. Traffic control resources are employed to impose
restrictions on the traffic flowing across directed edges in the transportation
network. Preventative resources are allocated to nodes to reduce the
probability of infection at that node (e.g. vaccines), and corrective resources
are allocated to nodes to increase the recovery rate at that node (e.g.
antidotes). We assume these resources have monetary costs associated with them,
from which we formalize an optimal budget allocation problem which maximizes
containment of the infection. We present a polynomial time solution to the
optimal budget allocation problem using Geometric Programming (GP) for an
arbitrary weighted and directed contact network and a large class of resource
cost functions. We illustrate our approach by designing optimal traffic control
strategies to contain an epidemic outbreak that propagates through a real-world
air transportation network.


title:
Many-body effects on electron spin dynamics in semiconductors from a
  geometrical viewpoint

abstract:
  Many body effects on spin dynamics in semiconductors have attracted a lot of
attentions in recent years. In this paper, we show why and how the many body
effects have to be considered by a simple Bloch sphere geometry approach. The
micro dynamics here are viewed as a time dependent sequence of unitary group
action on the spin density matrix. Based on this physical picture, we give the
explicit unitary group for conventional spin dynamics mechanism such as DP, EY,
and BAP using pure density matrix. And we also show the various scattering
processes how influence the spin system via mixed density matrix and Feynman
diagrams.


title:
A unified characterization of generalized information and certainty
  measures

abstract:
  In this paper we consider the axiomatic characterization of information and
certainty measures in a unified way. We present the general axiomatic system
which captures the common properties of a large number of the measures
previously considered by numerous authors. We provide the corresponding
characterization theorems and define a new generalized measure called the
Inforcer, which is the quasi-linear mean of the function associated to the
event probability following the general composition law. In particular, we pay
attention to the polynomial composition and the corresponding polynomially
composable Inforcer measure. The most common measures appearing in literature
can be obtained by specific choice of parameters appearing in our generic
measures and they are listed in tables.


title: Nonlinear Integrated Microwave Photonics

abstract:
  Harnessing nonlinear optical effects in a photonic chip scale has been proven
useful for a number of key applications in optical communications. Microwave
photonics can also benefit from the adoption of such a technology, creating a
new concept of nonlinear integrated microwave photonics. Here, we discuss the
potential of on-chip nonlinear processing towards the creation of robust and
multifunctional microwave photonic (MWP) processors. We also highlight key
recent results in the field, including frequency agile MWP filters and
ultra-wideband signal generators.


title: Symbolic Toolkit for Chaos Explorations

abstract:
  New computational technique based on the symbolic description utilizing
kneading invariants is used for explorations of parametric chaos in a two
exemplary systems with the Lorenz attractor: a normal model from mathematics,
and a laser model from nonlinear optics. The technique allows for uncovering
the stunning complexity and universality of the patterns discovered in the
bi-parametric scans of the given models and detects their organizing centers --
codimension-two T-points and separating saddles.


title: Laplacian Spectral Properties of Graphs from Random Local Samples

abstract:
  The Laplacian eigenvalues of a network play an important role in the analysis
of many structural and dynamical network problems. In this paper, we study the
relationship between the eigenvalue spectrum of the normalized Laplacian matrix
and the structure of `local' subgraphs of the network. We call a subgraph
\emph{local} when it is induced by the set of nodes obtained from a
breath-first search (BFS) of radius $r$ around a node. In this paper, we
propose techniques to estimate spectral properties of the normalized Laplacian
matrix from a random collection of induced local subgraphs. In particular, we
provide an algorithm to estimate the spectral moments of the normalized
Laplacian matrix (the power-sums of its eigenvalues). Moreover, we propose a
technique, based on convex optimization, to compute upper and lower bounds on
the spectral radius of the normalized Laplacian matrix from local subgraphs. We
illustrate our results studying the normalized Laplacian spectrum of a
large-scale online social network.


title:
GV-Index:Scientific Contribution Rating Index That Takes into Account
  the Growth Degree of Research Area and Variance Values of the Publication
  Year of Cited Paper

abstract:
  There are a wide variety of scientific contribution rating indices including
the impact factor and h-index. These are used for quantitative analyses on
research papers published in the past, and therefore unable to incorporate in
the assessment the growth, or deterioration, of the research area: whether the
research area of a particular paper is in decline or conversely in a growing
trend. Other hand, the use of the conventional rating indices may result in
higher rates for papers that are hardly referenced nowadays in other papers
although frequently cited in the past. This study proposes a new type of
scientific contribution ranking index, "Growing Degree of Research Area and
Variance Values Index (GV-Index)". The GV-Index is computed by a principal
component analysis based on an estimated value obtained by PageRank Algorithm,
which takes into account the growing degree of the research area and its
variance. We also propose visualization system of a scientist's network using
the GV-Index.


title:
Making and identifying optical superposition of very high orbital
  angular momenta

abstract:
  We report the experimental preparation of optical superpositions of high
orbital angular momenta(OAM). Our method is based on the use of spatial light
modulator to modify the standard Laguerre-Gaussian beams to bear excessive
phase helices. We demonstrate the surprising performance of a traditional
Mach-Zehnder interferometer with one inserted Dove prism to identify these
superposed twisted lights, where the high OAM numbers as well as their possible
superpositions can be inferred directly from the interfered bright multiring
lattices. The possibility of present scheme working at photon-count level is
also shown using an electron multiplier CCD camera. Our results hold promise in
high-dimensional quantum information applications when high quanta are
beneficial.


title:
Experimental study of a low-order wavefront sensor for a high-contrast
  coronagraphic imager at 1.2 lambda/D

abstract:
  High-contrast imaging will be a challenge for future ELTs, because their
vibrations create low-order aberrations - mostly tip/tilt - that reduce
coronagraphic performances at 1.2 lambda/D and above. A Low-Order WaveFront
Sensor (LOWFS) is essential to measure and control those aberrations. An
experiment simulating a starlight suppression system is currently developed at
NASA Ames Research Center, and includes a LOWFS controlling tip/tilt modes in
real-time at 500 Hz. The LOWFS allowed us to reduce the tip/tilt disturbances
to 1e-3 lambda/D rms, enhancing the previous contrast by a decade, to 8e-7
between 1.2 and 2 lambda/D. A Linear Quadratic Gaussian (LQG) controller is
currently implemented to improve even more that result by reducing residual
vibrations. This testbed is developed for the mission EXCEDE (EXoplanetary
Circumstellar Environments and Disk Explorer), selected by NASA for technology
development, and designed to study the formation, evolution and architectures
of exoplanetary systems and characterize circumstellar environments into
stellar habitable zones. It is composed of a 0.7 m telescope equipped with a
Phase-Induced Amplitude Apodization Coronagraph (PIAA-C) and a 2000-element
MEMS deformable mirror, capable of raw contrasts of 1e-6 at 1.2 lambda/D and
1e-7 above 2 lambda/D. Although the testbed simulates space conditions, its
LOWFS has the same design than on the SCExAO instrument at Subaru telescope,
with whom it shares the same kind of problematic. Experimental results show
that a good knowledge of the low-order disturbances is a key asset for high
contrast imaging, whether for real-time control or for post processing, both in
space and on ground telescopes.


title: A Lichnerowicz vanishing theorem for proper cocompact actions

abstract:
  We establish a Lichnerowicz type vanishing theorem for non-compact spin
manifolds admiting proper cocompact actions, when the action group is
unimodular.


title:
Dynamic Extraction of Key Paper from the Cluster Using Variance Values
  of Cited Literature

abstract:
  When looking into recent research trends in the field of academic landscape,
citation network analysis is common and automated clustering of many academic
papers has been achieved by making good use of various techniques. However,
specifying the features of each area identified by automated clustering or
dynamically extracted key papers in each research area has not yet been
achieved. In this study, therefore, we propose a method for dynamically
specifying the key papers in each area identified by clustering. We will
investigate variance values of the publication year of the cited literature and
calculate each cited paper's importance by applying the variance values to the
PageRank algorithm.


title: Polygonal Complexes and Graphs for Crystallographic Groups

abstract:
  The paper surveys highlights of the ongoing program to classify discrete
polyhedral structures in Euclidean 3-space by distinguished transitivity
properties of their symmetry groups, focussing in particular on various aspects
of the classification of regular polygonal complexes, chiral polyhedra, and
more generally, two-orbit polyhedra.


title: Distributed Queuing in Dynamic Networks

abstract:
  We consider the problem of forming a distributed queue in the adversarial
dynamic network model of Kuhn, Lynch, and Oshman (STOC 2010) in which the
network topology changes from round to round but the network stays connected.
This is a synchronous model in which network nodes are assumed to be fixed, the
communication links for each round are chosen by an adversary, and nodes do not
know who their neighbors are for the current round before they broadcast their
messages. Queue requests may arrive over rounds at arbitrary nodes and the goal
is to eventually enqueue them in a distributed queue. We present two algorithms
that give a total distributed ordering of queue requests in this model. We
measure the performance of our algorithms through round complexity, which is
the total number of rounds needed to solve the distributed queuing problem. We
show that in 1-interval connected graphs, where the communication links change
arbitrarily between every round, it is possible to solve the distributed
queueing problem in O(nk) rounds using O(log n) size messages, where n is the
number of nodes in the network and k <= n is the number of queue requests.
Further, we show that for more stable graphs, e.g. T-interval connected graphs
where the communication links change in every T rounds, the distributed queuing
problem can be solved in O(n+ (nk/min(alpha,T))) rounds using the same O(log n)
size messages, where alpha > 0 is the concurrency level parameter that captures
the minimum number of active queue requests in the system in any round. These
results hold in any arbitrary (sequential, one-shot concurrent, or dynamic)
arrival of k queue requests in the system. Moreover, our algorithms ensure
correctness in the sense that each queue request is eventually enqueued in the
distributed queue after it is issued and each queue request is enqueued exactly
once. We also provide an impossibility result for this distributed queuing
problem in this model. To the best of our knowledge, these are the first
solutions to the distributed queuing problem in adversarial dynamic networks.


title: Message and time efficient multi-broadcast schemes

abstract:
  We consider message and time efficient broadcasting and multi-broadcasting in
wireless ad-hoc networks, where a subset of nodes, each with a unique rumor,
wish to broadcast their rumors to all destinations while minimizing the total
number of transmissions and total time until all rumors arrive to their
destination. Under centralized settings, we introduce a novel approximation
algorithm that provides almost optimal results with respect to the number of
transmissions and total time, separately. Later on, we show how to efficiently
implement this algorithm under distributed settings, where the nodes have only
local information about their surroundings. In addition, we show multiple
approximation techniques based on the network collision detection capabilities
and explain how to calibrate the algorithms' parameters to produce optimal
results for time and messages.


title: Robust Leader Election in a Fast-Changing World

abstract:
  We consider the problem of electing a leader among nodes in a highly dynamic
network where the adversary has unbounded capacity to insert and remove nodes
(including the leader) from the network and change connectivity at will. We
present a randomized Las Vegas algorithm that (re)elects a leader in O(D\log n)
rounds with high probability, where D is a bound on the dynamic diameter of the
network and n is the maximum number of nodes in the network at any point in
time. We assume a model of broadcast-based communication where a node can send
only 1 message of O(\log n) bits per round and is not aware of the receivers in
advance. Thus, our results also apply to mobile wireless ad-hoc networks,
improving over the optimal (for deterministic algorithms) O(Dn) solution
presented at FOMC 2011. We show that our algorithm is optimal by proving that
any randomized Las Vegas algorithm takes at least omega(D\log n) rounds to
elect a leader with high probability, which shows that our algorithm yields the
best possible (up to constants) termination time.


title: Text Classification For Authorship Attribution Analysis

abstract:
  Authorship attribution mainly deals with undecided authorship of literary
texts. Authorship attribution is useful in resolving issues like uncertain
authorship, recognize authorship of unknown texts, spot plagiarism so on.
Statistical methods can be used to set apart the approach of an author
numerically. The basic methodologies that are made use in computational
stylometry are word length, sentence length, vocabulary affluence, frequencies
etc. Each author has an inborn style of writing, which is particular to
himself. Statistical quantitative techniques can be used to differentiate the
approach of an author in a numerical way. The problem can be broken down into
three sub problems as author identification, author characterization and
similarity detection. The steps involved are pre-processing, extracting
features, classification and author identification. For this different
classifiers can be used. Here fuzzy learning classifier and SVM are used. After
author identification the SVM was found to have more accuracy than Fuzzy
classifier. Later combined the classifiers to obtain a better accuracy when
compared to individual SVM and fuzzy classifier.


title:
The Pattern of CN, O, and Na Inhomogeneities on the Red Giant Branch of
  Messier 5

abstract:
  Data from the literature are used to explore the relation between
$\lambda$3883 CN band strength and the sodium and oxygen abundances of red
giants in the globular cluster Messier 5. Although there is a broad tendency
for CN-strong giants in this cluster to have higher sodium abundances and lower
oxygen abundances than CN-weak giants of comparable absolute magnitude there
are some secondary features in these relations. The oxygen abundance [O/Fe]
shows a greater range (0.6-0.7 dex) among the CN-strong giants than the CN-weak
giants (approximately 0.3 dex). By contrast [Na/Fe] shows a 0.6-0.7 dex range
among the CN-weak giants, but a more limited range of 0.3-0.4 dex among the
CN-strong giants. The $\lambda$3883 CN band anticorrelates in strength with
[O/Fe] among the CN-strong giants, but there is little, if any, such trend
among the CN-weak giants. In contrast, the CN band strength may show a modest
correlation with [Na/Fe] among the CN-weak giants, but there is little evidence
for such among the CN-strong giants. Neither oxygen or sodium abundance define
a continuous relation with CN band strength. Instead, the CN-strong and CN-weak
giants overlap in their sodium and possibly their oxygen abundances. At oxygen
abundances of [O/Fe] = 0.20 +/- 0.05 it is possible to have both CN-weak and
CN-strong giants, although there may be a discontinuity in [O/Fe] between these
two groups of stars that has been smeared out by observational errors. Both
CN-weak and CN-strong giants populate the sodium abundance range 0.4 <= [Na/Fe]
<= 0.6. Messier 5 may be displaying the results of spatially heterogeneous
chemical self-enrichment.


title:
Critical Binder cumulant and universality: Fortuin-Kasteleyn clusters
  and order-parameter fluctuations

abstract:
  We investigate the dependence of the critical Binder cumulant of the
magnetization and the largest Fortuin-Kasteleyn cluster on the boundary
conditions and aspect ratio of the underlying square Ising lattices. By means
of the Swendsen-Wang algorithm, we generate numerical data for large system
sizes and we perform a detailed finite-size scaling analysis for several values
of the aspect ratio $r$, for both periodic and free boundary conditions. We
estimate the universal probability density functions of the largest
Fortuin-Kasteleyn cluster and we compare it to those of the magnetization at
criticality. It is shown that these probability density functions follow
similar scaling laws, and it is found that the values of the critical Binder
cumulant of the largest Fortuin-Kasteleyn cluster are upper bounds to the
values of the respective order-parameter's cumulant, with a splitting behavior
for large values of the aspect ratio. We also investigate the dependence of the
amplitudes of the magnetization and the largest Fortuin-Kasteleyn cluster on
the aspect ratio and boundary conditions. We find that the associated
exponents, describing the aspect ratio dependencies, are different for the
magnetization and the largest Fortuin-Kasteleyn cluster, but in each case are
independent of boundary conditions.


title:
Localization of Shear in Saturated Granular Media: Insights from a
  Multi-Scaled Granular-Fluid Model

abstract:
  The coupled mechanics of fluid-filled granular media controls the behavior of
many natural systems such as saturated soils, fault gouge, and landslides. The
grain motion and the fluid pressure influence each other: It is well
established that when the fluid pressure rises, the shear resistance of
fluid-filled granular systems decreases, and as a result catastrophic events
such as soil liquefaction, earthquakes, and accelerating landslides may be
triggered. Alternatively, when the pore pressure drops, the shear resistance of
these systems increases. Despite the great importance of the coupled mechanics
of grains-fluid systems, the basic physics that controls this coupling is far
from understood. We developed a new multi-scaled model based on the discrete
element method, coupled with a continuum model of fluid pressure, to explore
this dynamical system. The model was shown recently to capture essential
feedbacks between porosity changes arising from rearrangement of grains, and
local pressure variations due to changing pore configurations. We report here
new results from numerical experiments of a continuously shearing layer of
circular two-dimensional grains, trapped between two parallel rough boundaries.
The experiments use a fixed confining stress on the boundary walls, and a
constant velocity applied to one of the boundaries, as if this system was the
interior of a sliding geological fault filled with 'fault gouge'. In addition,
we control the layer permeability and the drainage boundary conditions. This
paper presents modeling results showing that the localization of shear (into a
narrow shear band within the shearing layer) is strongly affected by the
presence of fluids. While in dry granular layers there is no preferred position
for the onset of localization, drained systems tend to localize shear on their
boundary. We propose a scaling argument to describe the pressure deviations in
a shear band, and use that to predict the allowable positions of shear
localizations as a function of the fault and gouge properties.


title:
Origin of spectral purity and tuning sensitivity in a vortex-based spin
  transfer nano-oscillator

abstract:
  We investigate the microwave characteristics of a spin transfer
nano-oscillator (STNO) based on coupled vortices as a function of the
perpendicular magnetic field $H_\perp$. While the generation linewidth displays
strong variations on $H_\perp$ (from 40 kHz to 1 MHz), the frequency tunability
in current remains almost constant (~7 MHz/mA). We demonstrate that our
vortex-based oscillator is quasi-isochronous independently of $H_\perp$, so
that the severe nonlinear broadening usually observed in STNOs does not exist.
Interestingly, this does not imply a loss of frequency tunability, which is
here governed by the current induced Oersted field. Nevertheless this is not
sufficient to achieve the highest spectral purity in the full range of
$H_\perp$ either: we show that the observed linewidth broadenings are due to
the excited mode interacting with a lower energy overdamped mode, which occurs
at the successive crossings between harmonics of these two modes. These
findings open new possibilities for the design of STNOs and the optimization of
their performance.


title: Activity date estimation in timestamped interaction networks

abstract:
  We propose in this paper a new generative model for graphs that uses a latent
space approach to explain timestamped interactions. The model is designed to
provide global estimates of activity dates in historical networks where only
the interaction dates between agents are known with reasonable precision.
Experimental results show that the model provides better results than local
averages in dense enough networks


title: Fitting ideals and multiple-points of surface parameterizations

abstract:
  Given a birational parameterization of an algebraic surface S in the
projective space, the purpose of this paper is to investigate the sets of
points on S whose preimage consists in k or more points, counting
multiplicities. They are described explicitly in terms of Fitting ideals of
some graded parts of the symmetric algebra associated to this parameterization.


title:
Solar Transients disturbing the Terrestrial Magnetic Environment at
  Higher Latitudes

abstract:
  Geomagnetic field variations during five major Solar Energetic Particle (SEP)
events of solar cycle 23 have been investigated in the present study. The SEP
events of 01 oct 2001, 04 Nov 2001, 21 Apr 2002 and 14 May 2005 have been
selected to study the geomagnetic field variations at two high-latitude
stations, Thule and Resolute Bay of the northern polar cap. We have used the
GOES protn flux in seven different energy channels. All the proton events were
associated with geoeffective or Earth directed CMEs that caused intense
geomagnetic storms in response to geospace. We have taken high-latitude
indices, AE and PC, under consideration and found fairly good correlation of
thees with the ground magnetic field records during the five proton events. The
departure of H component during the events were calculated from the quietest
day of the month for each event. The correspondence of spectral index, inferred
from event integrated spectra, with ground magnetic signatures along with Dst
and PC indices have been brought out. From the correlation analysis we found
very strong correlation to exist between the geomagnetic field variations and
high latitude indices AE and PC. To find the association of geomagnetic storm
intensity with proton and geomagnetic field variations along with the Dst and
AE index. We found a strong correlation (0.88) to exist between the spectral
indices and magnetic field deviations and also between spectral indices and AE
and PC.


title: Pullback Attractors for Generalized Evolutionary Systems

abstract:
  We give an abstract framework for studying nonautonomous PDEs, called a
generalized evolutionary system. In this setting, we define the notion of a
pullback attractor. Moreover, we show that the pullback attractor, in the weak
sense, must always exist. We then study the structure of these attractors and
the existence of a strong pullback attractor. We then apply our framework to
both autonomous and nonautonomous evolutionary systems as they first appeared
in earlier works by Cheskidov, Foias, and Lu. In this context, we compare the
pullback attractor to both the global attractor (in the autonomous case) and
the uniform attractor (in the nonautonomous case). Finally, we apply our
results to the nonautonomous 3D Navier-Stokes equations on a periodic domain
with a translationally bounded force. We show that the Leray-Hopf weak
solutions form a generalized evolutionary system and must then have a weak
pullback attractor.


title:
A Three-Dimensional Optical Lattice of Ytterbium and Lithium Atomic
  Mixture

abstract:
  We develop an optical lattice system for an ultracold atomic gas mixture of
ytterbium (174Yb) and lithium (6Li), which is an ideal system to study disorder
and impurity problems. We load a Bose-Einstein condensate of 174Yb into a
three-dimensional optical lattice and observe the interference patterns in
time-of-flight (TOF) images. Furthermore, we perform a laser spectroscopy of
174Yb in an optical lattice using the ultra-narrow optical transition 1S0-3P2
in both cases with and without 6Li. Due to the weak interspecies interaction,
we do not observe the clear influences of 6Li in the obtained interference
patterns and the excitation spectra. However, this is an important first step
of optical control of atomic impurity in ultracold fermions. We also measure
the polarizabilities of the 3P2 state of 174Yb atoms in an optical trap with a
wavelength of 1070 nm. We reveal that the polarizability can be tuned to
positive, zero, or the same as the ground state, which are useful for certain
applications.


title:
Reducing Failure Probability of cloud storage services using
  Multi-Clouds

abstract:
  Any information is valuable as long as it has related data. If related data
are not put together, the information is meaningless as unrelated data has no
value. The mapped information is required only by authenticated users. So there
is no necessity to store related information together. If the relations of a
database are fragmented into chunks and these chunks are stored at different
cloud service providers, it could prevent from any privacy breach and the data
stored will be secure. It would also reduce the data transfer costs as the
entire data is not always required, for e.g. during updates. Also, instead of
storage of chunks at a single CSP, if each chunk or fragment is stored at
multiple CSPs it ensures availability and also permits concurrent access.
Additionally, it would prevent financial loss during cloud outages and also
prevent data lock-in. Replicating data chunks at multiple clouds situated at
geographically different locations would also have an additional decrease in
response time. The work attempts to select multiple cloud service providers
within a given budget so as to ensure maximum availability of data. The entire
data can be stored at each of the data centers selected depending on the budget
when there is no security or privacy issue. Data can also be stored in chunks
by replicating each data chunk at two or more cloud service providers.
Different chunks can be replicated at different service providers. The work
also attempts to select various cloud service providers to ensure maximum valid
data chunks within a given budget.


title:
Raman evidence for coupling of superconducting quasi-particles with a
  phonon and crystal field excitation in superconductor Ce0.6Y0.4FeAsO0.8F0.2

abstract:
  We report inelastic light scattering experiments on superconductor
Ce0.6Y0.4FeAsO0.8F0.2 from 4K to 300K covering the superconducting transition
temperature Tc ~ 48.6K. A strong evidence of the superconductivity induced
phonon renormalization for the A1g phonon mode near 150 cm-1 associated with
the Ce/Y vibrations is observed as reflected in the anomalous red-shift and
decrease in the linewidth below Tc. Invoking the coupling of this mode with the
superconducting gap, the superconducting gap (2) at zero temperature is
estimated to be ~ 20 meV i.e the ratio is ~ 5, suggesting Ce0.6Y0.4FeAsO0.8F0.2
to belong to the class of strong coupling superconductors. In addition, the
mode near 430 cm-1 associated with Ce3+ crystal field excitation also shows
anomalous increase in its linewidth below Tc suggesting strong coupling between
crystal field excitation and the superconducting quasi-particles. Our
observations of two high frequency modes (S9 and S10) evidence the
non-degenerate nature of Fe2+ dxz/yz orbitals suggesting the electronic
nematicity in these systems.


title:
Numerical and experimental study of the interaction between two marine
  current turbines

abstract:
  The understanding of interaction effects between marine energy converters
represents the next step in the research process that should eventually lead to
the deployment of such devices. Although some a priori considerations have been
suggested recently, very few real condition studies have been carried out
concerning this issue. Trials were run on 1/30th scale models of three-bladed
marine current turbine prototypes in a flume tank. The present work focuses on
the case where a turbine is placed at different locations in the wake of a
first one. The interaction effects in terms of performance and wake of the
second turbine are examined and compared to the results obtained on the case of
one single turbine. Besides, a three-dimensional software, based on a vortex
method is currently being developed, and will be used in the near future to
model more complex layouts. The experimental study shows that the second
turbine is deeply affected by the presence of an upstream device and that a
compromise between individual device performance and inter-device spacing is
necessary. Numerical results show good agreement with the experiment and are
promising for the future modelling of turbine farms.


title: Quantum Hashing

abstract:
  We present a version of quantum hash function based on non-binary discrete
functions. The proposed quantum procedure is "classical-quantum", that is, it
takes a classical bit string as an input and produces a quantum state. The
resulting function has the property of a one-way function (pre-image
resistance), in addition it has the properties analogous to classical
cryptographic hash second pre-image resistance and collision resistance. This
function can be naturally used in a quantum digital signature protocol.


title:
Gate-modulated thermopower in disordered nanowires: I. Low temperature
  coherent regime

abstract:
  Using a one-dimensional tight-binding Anderson model, we study a disordered
nanowire in the presence of an external gate which can be used for depleting
its carrier density (field effect transistor device configuration). In this
first paper, we consider the low temperature coherent regime where the electron
transmission through the nanowire remains elastic. In the limit where the
nanowire length exceeds the electron localization length, we derive three
analytical expressions for the typical value of the thermopower as a function
of the gate potential, in the cases where the electron transport takes place
(i) inside the impurity band of the nanowire, (ii) around its band edges and
eventually (iii) outside its band. We obtain a very large enhancement of the
typical thermopower at the band edges, while the sample to sample fluctuations
around the typical value exhibit a sharp crossover from a Lorentzian
distribution inside the impurity band towards a Gaussian distribution as the
band edges are approached.


title: Solar neutrinos, helicity effects and new affine gravity with torsion

abstract:
  New f(R,T) model of gravitation, introduced previously by the author, is
considered. It is based on an affine geometrical construction in which the
torsion is a dynamical field, the coupling is minimal and the theory is Lorentz
invariant by construction. It was shown that the Dirac equation emerges from
the same space time and acquires a modification (coupling-like) of the form
{\gamma}^{{\alpha}}j((1-d)/d){\gamma}h_{{\alpha}}, with h_{{\alpha}} the
torsion axial vector, j a parameter of pure geometrical nature and d, the
spacetime dimension. In the present work it is shown that this interaction
produces a mechanism of spin (helicity) flipping, with its consequent weak
symmetry violation. The cross section of this process is explicitly calculated
and a logaritmical energy dependence (even at high energies) is found. This
behavior is reminiscent of similar computations made by Hans Bethe in the
context of neutrino astrophysics. These results are applied to the solar
neutrino case and compared with similar results coming from a gravitational
model with torsion of string theory type and within the standard model context
respectively.


title:
Halo/Galaxy Bispectrum with Primordial non-Gaussianity from integrated
  Perturbation Theory (iPT)

abstract:
  We derive a formula for the halo/galaxy bispectrum on the basis of the
integrated Perturbation Theory (iPT). In addition to the gravity-induced
non-Gaussianity, we consider the non-Gaussianity of the primordial curvature
perturbations, and investigate in detail the effect of such primordial
non-Gaussianity on the large-scale halo/galaxy bispectrum. In iPT, the effects
of primordial non-Gaussianity are wholly encapsulated in the linear
(primordial) polyspectra, and we systematically calculate the contributions to
the large-scale behaviors arising from the three types of primordial bispectrum
(local-, equilateral-, and orthogonal-types), and primordial trispectrum of the
local-type non-Gaussianity. We find that the equilateral- and orthogonal-type
non-Gaussianities show distinct scale-dependent behaviors which can dominate
the gravity-induced non-Gaussianity at very large scales. For the local-type
non-Gaussianity, higher-order loop corrections are found to give a
significantly large contribution to the halo/galaxy bispectrum of the squeezed
shape, and eventually dominate over the other contributions on large scales. A
diagrammatic approach based on the iPT helps us to systematically investigate
an impact of such higher-order contributions to the large-scale halo/galaxy
bispectrum.


title: Abstract Phase-space Networks Describing Reactive Dynamics

abstract:
  An abstract network approach is proposed for the description of the dynamics
in reactive processes. The phase space of the variables (concentrations in
reactive systems) is partitioned into a finite number of segments, which
constitute the nodes of the abstract network. Transitions between the nodes are
dictated by the dynamics of the reactive process and provide the links between
the nodes. These are weighted networks, since each link weight reflects the
transition rate between the corresponding states-nodes. With this construction
the network properties mirror the dynamics of the underlying process and one
can investigate the system properties by studying the corresponding abstract
network. As a working example the Lattice Limit Cycle (LLC) model is used. Its
corresponding abstract network is constructed and the transition matrix
elements are computed via Kinetic (Dynamic) Monte Carlo simulations. For this
model it is shown that the degree distribution follows a power law with
exponent -1, while the average clustering coefficient $c(N)$ scales with the
network size (number of nodes) $N$ as $c(N)\sim N^{-\nu}, \nu \simeq 1.46$. The
computed exponents classify the LLC abstract reactive network into the
scale-free networks. This conclusion corroborates earlier investigations
demonstrating the formation of fractal spatial patterns in LLC reactive
dynamics due to stochasticity and to the clustering of homologous species. The
present construction of abstract networks (based on the partition of the phase
space) is generic and can be implemented with appropriate adjustments in many
dynamical systems and in time series analysis.


title:
New solutions with peakon creation in the Camassa-Holm and Novikov
  equations

abstract:
  In this article we study a new kind of unbounded solutions to the Novikov
equation, found via a Lie symmetry analysis. These solutions exhibit peakon
creation, i.e., these solutions are smooth up until a certain finite time, at
which a peak is created. We show that the functions are still weak solutions
for those times where the peak lives. We also find similar unbounded solutions
with peakon creation in the related Camassa-Holm equation, by making an ansatz
inspired by the Novikov solutions. Finally, we see that the same ansatz for the
Degasperis-Procesi equation yields unbounded solutions where a peakon is
present for all times.


title:
The confirmation and revision on the orbital period change of the
  possible type Ia supernova progenitor V617 Sagittarii

abstract:
  This work reports new photometric results of eclipsing cataclysmic variable
V617 Sagittarii (V617 Sgr). We analyzed the orbital period change of V617 Sgr,
by employing three new CCD eclipse timings since 2010 along with all the
available data from the literature. It was found that the orbital period of
V617 Sgr undergoes an obvious long-term increase, which confirms the result
revealed by Steiner et al. (2006). The rate of orbital period increase was
calculated to be ${\dot{P}}$ = +2.14(0.05) $\times$ 10$^{-7}$ day/year. This
suggests the lifetime of the secondary star will attain to the end in a
timescale of 0.97 $\times$ 10$^6$ years faster than that predicted previously.
In particular, a cyclic variation with a period of 4.5 year and an amplitude of
2.3 minutes may present in the O-C diagram. Dominated by the wind-accretion
mechanism, high mass transfer from the low mass secondary to the white dwarf is
expected to sustain in the V Sge-type star V617 Sgr during its long-term
evolution. The mass transfer rate $|\dot{M}_{tr}|$ was estimated to be in the
range of about 2.2 $\times$ 10$^{-7}$ to 5.2 $\times$ 10$^{-7}$ M$_{\odot}$
yr$^{-1}$. Accordingly, the already massive ($\geq$ 1.2 M$_{\odot}$) white
dwarf primary will process stable nuclear burning, accrete a fraction of mass
from its companion to reach the standard Chandrasekhar mass limit ($\simeq$
1.38 M$_{\odot}$), and ultimately produce a type Ia supernova (SN Ia) within
about 4 $\sim$ 8 $\times$ 10$^{5}$ years or earlier.


title: The orthogonal gamma-ray burst model

abstract:
  We explore the analogy between a rotating magnetized black hole and an
axisymmetric pulsar and derive its electromagnetic spindown after its formation
in the core collapse of a supermassive star. The spindown shows two
characteristic phases, an early Blandford-Znajek phase that lasts a few hundred
seconds, and a late pulsar-like afterglow phase that lasts much longer. During
the first phase, the spindown luminosity decreases almost exponentially,
whereas during the afterglow phase it decreases as t^{-a} with 1<a<1,5. We
associate our findings with long duration gamma-ray bursts (GRB) and compare
with observations.


title:
Elementary excitations of antiferromagnetic spin-1 bosons in an optical
  lattice

abstract:
  We study elementary excitations of spin-1 bosons with antiferromagnetic
interaction in an optical lattice by applying the Gutzwiller approximation to
the spin-1 Bose-Hubbard model. There appear various excitations associated with
spin degrees of freedom in the Mott-insulator (MI) phase as well as in the
superfluid (SF) phase. In this system, the ground state in the MI phase is
known to exhibit a remarkable effect of even-odd parity of particle filling, in
which even fillings stabilize the MI state due to formation of spin-singlet
pairs. We find that excitation spectra in the MI phase exhibit characteristic
features that reflect the even-odd parity effect of the ground state. We
clarify evolution of elementary excitations across the quantum critical point
of the SF-MI transition.


title: A new standard pulsar magnetosphere

abstract:
  In view of recent efforts to probe the physical conditions in the pulsar
current sheet, we revisit the standard solution that describes the main
elements of the ideal force-free pulsar magnetosphere. The simple physical
requirement that the electric current contained in the current layer consists
of the local electric charge moving outward at close to the speed of light,
yields a new standard solution for the pulsar magnetosphere everywhere ideal
force-free except in the current layer. The main elements of the new solution
are a) the pulsar spindown rate of the aligned rotator is 23% times larger than
that of the orthogonal vacuum rotator, b) only 60% of the magnetic flux that
crosses the light cylinder opens up to infinity, c) the electric current closes
along the other 40% which gradually converges to the equator, d) this transfers
40% of the total pulsar spindown energy flux in the equatorial current sheet
which is then dissipated in the acceleration of particles and in high-energy
electromagnetic radiation, e) there is no separatrix current layer. Our
solution is a minimum free-parameter solution in that the equatorial current
layer is electrostatically supported against collapse and thus does not require
a thermal particle population. In that respect, it is one more step toward the
development of a new standard solution. We discuss the implications for
intermittent pulsars and long duration gamma-ray bursts. We conclude that the
physical conditions in the equatorial current layer determine the global
structure of the pulsar magnetosphere.


title: Chemo-dynamical simulations of dwarf galaxy evolution

abstract:
  In this review I give a summary of the state-of-the-art for what concerns the
chemo-dynamical numerical modelling of galaxies in general and of dwarf
galaxies in particular. In particular, I focus my attention on (i) initial
conditions; (ii) the equations to solve; (iii) the star formation process in
galaxies; (iv) the initial mass function; (v) the chemical feedback; (vi) the
mechanical feedback; (vii) the environmental effects. Moreover, some key
results concerning the development of galactic winds in galaxies and the fate
of heavy elements, freshly synthesised after an episode of star formation, have
been reported. At the end of this review, I summarise the topics and physical
processes, relevant for the evolution of galaxies, that in my opinion are not
properly treated in modern computer simulations of galaxies and that deserve
more attention in the future.


title:
Thermodynamics from field equations for black holes with multiple
  horizons

abstract:
  The first law of black hole thermodynamics can be read off from the field
equations at the horizon. Until now, for black holes with multiple horizons the
field equations only at the outer horizon were employed with a particular
constraint. In this paper, however, we suggest that for a black hole with
multiple horizons the field equations at the inner horizon as well as the outer
horizon should be needed in order to obtain the first law of black hole
thermodynamics in general.


title: Inhomogeneity Effects in Topological Superconductors

abstract:
  We have constructed a quasiclassical framework on superconductors with strong
spin-orbit couplings, applicable to CuxBi2Se3[Y. Nagai, H. Nakamura, and M.
Machida: arXiv:1305.3025]. The notable point is that in this framework the
Bogoliubov-de Gennes Hamiltonians with suggested odd-parity pairing states turn
to quasiclassical ones with usual spin-triplet Cooper pairs. Using this
quasiclassical theory, we can investigate inhomogeneity effects such as the
phenomena with vortices and surfaces in this superconductors and shed light on
the pairing state of topological superconductors. In this paper, we apply the
quasiclassical framework to the surface bound states with the Dirac-cone energy
dispersion originated from the topological invariant in the parent compound
Bi2Se3 in order to investigate the robustness of these bound states under the
superconducting order parameter. The odd-parity gap functions can not open on
the Dirac-cone-dispersion band in the Cu-doped Bi$_{2}$Se$_{3}$ superconductor.
We show that the massless Dirac quasiparticles originated from the normal-state
topological invariant and the Majorana quasiparticles coexist with each other
on the surface in the odd-parity topological superconductivity. Inhomogeneity
effects can be easily investigated with the use of our quasiclassical framework
in topological superconductors.


title: Online Packet Scheduling under Adversarial Jamming

abstract:
  We consider the problem of scheduling packets of different lengths via a
directed communication link prone to jamming errors. Dynamic packet arrivals
and errors are modelled by an adversary. We focus on estimating relative
throughput of online scheduling algorithms, that is, the ratio between the
throughputs achieved by the algorithm and the best scheduling for the same
arrival and error patterns. This framework allows more accurate analysis of
performance of online scheduling algorithms, even in worst-case arrival and
error scenarios. We design an online algorithm for scheduling packets of
arbitrary lengths, achieving optimal relative throughput in the range (1/3,1/2]
(the exact value depends on packet lengths). In other words, for any arrival
and jamming patterns, our solution gives throughput which is no more than c
times worse than the best possible scheduling for these patters, where c in [2;
3) is the inverse of relative throughput. Another algorithm we design makes use
of additional resources in order to achieve relative throughput 1, that is, it
achieves at least as high throughput as the best schedule without such
resources, for any arrival and jamming patterns. More precisely, we show that
if the algorithm can run with double speed, i.e., with twice higher frequency,
then its relative throughput is 1. This demonstrates that throughput of the
best online scheduling algorithms scales well with resource augmentation.
  Keywords: Packet scheduling, Dynamic packet arrivals, Adversarial jamming,
Online algorithms, Relative throughput, Resource augmentation.


title:
Stochastic stellar cluster IMFs: Models and impact on integrated cluster
  parameter determination

abstract:
  Stellar clusters are regularly used to study the evolution of their host
galaxy. Except for a few nearby galaxies, these studies rely on the
interpretation of integrated cluster properties, especially integrated
photometry observed using multiple filters (i.e. the Spectral Energy
Distribution SED). To allow interpretation of such observations, we present a
large set of GALEV cluster models using the realistic approach of adopting
stochastically-sampled stellar IMFs. We provide models for a wide range of
cluster masses (10^3 - 2 * 10^5$ Msun), metallicities (-2.3 <= [Fe/H] <= +0.18
dex), foreground extinction, and 184 regularly used filters. We analyze various
sets of stochastic cluster SEDs by fitting them with non-stochastic models,
which is the procedure commonly used in this field. We identify caveats and
quantify the fitting uncertainties associated with this standard procedure. We
show that this can yield highly unreliable fitting results, especially for
low-mass clusters.


title:
Mn$^{2+}$/Mn$^{3+}$ state of La$_{0.7}$Ce$_{0.3}$MnO$_3$ by oxygen
  reduction and photodoping

abstract:
  Films of cerium-doped LaMnO$_3$, which has been intensively discussed as an
electron-doped counterpart to hole-doped mixed-valence lanthanum manganites
during the past decade, were analyzed by x-ray photoemission spectroscopy with
respect to their manganese valence under photoexcitation. The comparative
analysis of the Mn 3s exchange splitting of La$_{0.7}$Ce$_{0.3}$MnO$_3$ (LCeMO)
films in the dark and under illumination clearly shows that both oxygen
reduction and illumination are able to decrease the Mn valence towards a mixed
2$+$/3$+$ state, independently of the film thickness and the degree of CeO$_2$
segregation. Charge injection from the photoconductive SrTiO$_3$ substrate into
the Mn e$_g$ band with carrier lifetimes in the range of tens of seconds and
intrinsic generation of electron-hole pairs within the films are discussed as
two possible sources of the Mn valence shift and the subsequent electron
doping.


title:
A Logic-based Approach for Recognizing Textual Entailment Supported by
  Ontological Background Knowledge

abstract:
  We present the architecture and the evaluation of a new system for
recognizing textual entailment (RTE). In RTE we want to identify automatically
the type of a logical relation between two input texts. In particular, we are
interested in proving the existence of an entailment between them. We conceive
our system as a modular environment allowing for a high-coverage syntactic and
semantic text analysis combined with logical inference. For the syntactic and
semantic analysis we combine a deep semantic analysis with a shallow one
supported by statistical models in order to increase the quality and the
accuracy of results. For RTE we use logical inference of first-order employing
model-theoretic techniques and automated reasoning tools. The inference is
supported with problem-relevant background knowledge extracted automatically
and on demand from external sources like, e.g., WordNet, YAGO, and OpenCyc, or
other, more experimental sources with, e.g., manually defined presupposition
resolutions, or with axiomatized general and common sense knowledge. The
results show that fine-grained and consistent knowledge coming from diverse
sources is a necessary condition determining the correctness and traceability
of results.


title:
Asymptotically optimal decision rules for joint detection and source
  coding

abstract:
  The problem of joint detection and lossless source coding is considered. We
derive asymptotically optimal decision rules for deciding whether or not a
sequence of observations has emerged from a desired information source, and to
compress it if has. In particular, our decision rules asymptotically minimize
the cost of compression in the case that the data has been classified as
`desirable', subject to given constraints on the two kinds of the probability
of error. In another version of this performance criterion, the constraint on
the false alarm probability is replaced by the a constraint on the cost of
compression in the false alarm event. We then analyze the asymptotic
performance of these decision rules and demonstrate that they may exhibit
certain phase transitions. We also derive universal decision rules for the case
where the underlying sources (under either hypothesis or both) are unknown, and
training sequences from each source may or may not be available. Finally, we
discuss how our framework can be extended in several directions.


title:
The Potential for Detecting Gamma-Ray Burst Afterglows from Population
  III Stars with the Next Generation of Infrared Telescopes

abstract:
  We investigate the detectability of a proposed population of Gamma-Ray Bursts
(GRBs) from the collapse of Population III (Pop III) stars. The James Webb
Space Telescope (JWST) and Space Infrared telescope for Cosmology and
Astrophysics (SPICA) will be able to observe the late time infrared afterglows.
We have developed a new method to calculate their detectability, which takes
into account the fundamental initial mass function (IMF) and formation rates of
Pop III stars, from which we find the temporal variability of the afterglows
and ultimately the length of time JWST and SPICA can detect them. In the range
of plausible Pop III GRB parameters, the afterglows are always detectable by
these instruments during the isotropic emission, for a minimum of 55 days and a
maximum of 3.7 years. The average number of detectable afterglows will be
2.96$\times 10^{-5}$ per SPICA field of view (FOV) and 2.78$\times 10^{-6}$ per
JWST FOV. These are lower limits, using a pessimistic estimate of Pop III star
formation. An optimal observing strategy with SPICA could identify a candidate
orphan afterglow in $\sim 1.3$ years, with a 90 percent probability of
confirmation with further detailed observations. A beamed GRB will align with
the FOV of the planned GRB detector Energetic X-ray Imaging Survey Telescope
once every 9 years. Pop III GRBs will be more easily detected by their
isotropic emissions (i.e. orphan afterglows) rather than by their prompt
emissions.


title: Duality for local fields and sheaves on the category of fields

abstract:
  Duality for complete discrete valuation fields with perfect residue field
with coefficients in (possibly p-torsion) finite flat group schemes was
obtained by Begueri, Bester and Kato. In this paper, we give another
formulation and proof of this result. We use the category of fields and a
Grothendieck topology on it. This simplifies the formulation and proof and
reduces the duality to classical results on Galois cohomology. A key point is
that the resulting site correctly captures extension groups between algebraic
groups.


title: On a non-linear $p$-adic dynamical system

abstract:
  We investigate the behavior of trajectories of a $(3,2)$-rational $p$-adic
dynamical system in the complex $p$-adic filed ${\mathbb C}_p$, when there
exists a unique fixed point $x_0$. We study this $p$-adic dynamical system by
dynamics of real radiuses of balls (with the center at the fixed point $x_0$).
We show that there exists a radius $r$ depending on parameters of the rational
function such that: when $x_0$ is an attracting point then the trajectory of an
inner point from the ball $U_r(x_0)$ goes to $x_0$ and each sphere with a
radius $>r$ (with the center at $x_0$) is invariant; When $x_0$ is a repeller
point then the trajectory of an inner point from a ball $U_r(x_0)$ goes forward
to the sphere $S_r(x_0)$. Once the trajectory reaches the sphere, in the next
step it either goes back to the interior of $U_r(x_0)$ or stays in $S_r(x_0)$
for some time and then goes back to the interior of the ball. As soon as the
trajectory goes outside of $U_r(x_0)$ it will stay (for all the rest of time)
in the sphere (outside of $U_r(x_0)$) that it reached first.


title: N-continuous OFDM: System Optimization and Performance Analysis

abstract:
  N-continuous orthogonal frequency division multiplexing (NC-OFDM) is a
promising technique to achieve significant sidelobe suppression of baseband
OFDM signals. However, the high complexity limits its application. Based on
conventional NC-OFDM, in this paper, a new technique, called time-domain
N-continuous OFDM (TD-NC-OFDM), is proposed to transfer the original
frequency-domain processing to the time domain, by the linear combination of a
novel basis set to smooth the consecutive OFDM symbols and their high-order
derivatives. We prove that TD-NC-OFDM is an equivalent to conventional one
while consuming much lower complexity. Furthermore, via the time-domain
structure, a closed-form spectral expression of NC-OFDM signals is derived and
a compact upper bound of sidelobe decaying is derived. This paper also
investigates the impact of the TD-NC-OFDM technique on received
signal-to-interference-plus-noise ratio (SINR) and provides a closed-form
analytical expression. Theoretical analyses and simulation results show that
TD-NC-OFDM can prohibitively suppress the sidelobe with much lower complexity.


title: Are Ultra-long Gamma-Ray Bursts different?

abstract:
  The discovery of a number of gamma-ray bursts with duration exceeding 1,000
seconds, in particular the exceptional case of GRB 111209A with a duration of
about 25,000 seconds, has opened the question on whether these bursts form a
new class of sources, the so called {\em ultra-long} GRBs, or if they are
rather the tail of the distribution of the standard long GRB duration. In this
Letter, using the long GRB sample detected by {\em Swift}, we investigate on
the statistical properties of ultra-long GRBs and compare them with the overall
long burst population. We discuss also on the differences observed in their
spectral properties. We find that ultra-long GRBs are statistically different
from the standard long GRBs with typical burst duration less than 100-500
seconds, for which a Wolf Rayet star progenitor is usually invoked. We
interpret this result as an indication that an alternative scenario has to be
found in order to explain the ultra-long GRB extreme energetics, as well as the
mass reservoir and its size that can feed the central engine for such a long
time.


title: A novel sparsity and clustering regularization

abstract:
  We propose a novel SPARsity and Clustering (SPARC) regularizer, which is a
modified version of the previous octagonal shrinkage and clustering algorithm
for regression (OSCAR), where, the proposed regularizer consists of a
$K$-sparse constraint and a pair-wise $\ell_{\infty}$ norm restricted on the
$K$ largest components in magnitude. The proposed regularizer is able to
separably enforce $K$-sparsity and encourage the non-zeros to be equal in
magnitude. Moreover, it can accurately group the features without shrinking
their magnitude. In fact, SPARC is closely related to OSCAR, so that the
proximity operator of the former can be efficiently computed based on that of
the latter, allowing using proximal splitting algorithms to solve problems with
SPARC regularization. Experiments on synthetic data and with benchmark breast
cancer data show that SPARC is a competitive group-sparsity inducing
regularizer for regression and classification.


title:
Local dynamic stability of treadmill walking: intrasession and
  week-to-week repeatability

abstract:
  Repetitive falls degrade the quality of life of elderly people and of
patients suffering of various neurological disorders. In order to prevent falls
while walking, one should rely on relevant early indicators of impaired dynamic
balance. The local dynamic stability (LDS) represents the sensitivity of gait
to small perturbations: divergence exponents (maximal Lyapunov exponents)
assess how fast a dynamical system diverges from neighbor points. Although
numerous findings attest the validity of LDS as a fall risk index, reliability
results are still sparse. The present study explores the intrasession and
intersession repeatability of gait LDS using intraclass correlation
coefficients (ICC) and standard error of measurement (SEM). Ninety-five healthy
individuals performed 5min. treadmill walking in two sessions separated by 9
days. Trunk acceleration was measured with a 3D accelerometer. Three time
scales were used to estimate LDS: over 4 to 10 strides ({\lambda}4-10), over
one stride ({\lambda}1) and over one step ({\lambda}0.5). The intrasession
repeatability was assessed from three repetitions of either 35 strides or 70
strides taken within the 5min tests. The intersession repeatability compared
the two sessions, which totalized 210 strides. The intrasession ICCs
(70-strides estimates/35-strides estimates) were 0.52/0.18 for {\lambda}4-10
and 0.84/0.77 for {\lambda}1 and {\lambda}0.5. The intersession ICCs were
around 0.60. The SEM results revealed that {\lambda}0.5 measured in
medio-lateral direction exhibited the best reliability, sufficient to detect
moderate changes at individual level (20%). However, due to the low
intersession repeatability, one should average several measurements taken on
different days in order to better approximate the true LDS.


title:
Infinitesimal algebraic skeletons for a (2+1)-dimensional Toda type
  system

abstract:
  A tower for a (2+1)-dimensional Toda type system is constructed in terms of a
series expansion of operators which can be interpreted as generalized Bessel
coefficients; the result is formulated as an analog of the
Baker-Campbell-Hausdorff formula. We tackle the problem of the construction of
infinitesimal algebraic skeletons for such a tower and discuss some open
problems arising along our approach. In particular, we realize the prolongation
skeleton as a Kac-Moody algebra.


title:
Calculation of Fayet-Iliopoulos D-term in type I string theory
  revisited: T^6/Z_3 orbifold case

abstract: This paper has been withdrawn by the author due to a crucial error.


title:
Global mibility and handover management for heterogeneous network in
  VANET

abstract:
  Now a days Vehicular Ad hoc Network is an emerging technology. Mobility
management is one of the most challenging research issues for Vehicular Ad hoc
Network to support variety of intelligent transportation system applications.
Vehicular Ad hoc Networks are getting importance for inter-vehicle
communication, because they allow the communication among vehicles without any
infrastructure, configuration effort, and without the high costs of cellular
networks. Besides local data exchange, vehicular applications may be used to
accessing Internet services. The access is provided by Internet gateways
located on the site of roadside. However, the Internet integration requires a
respective mobility support of the vehicular ad hoc network. In this paper we
will study about the network mobility approach in vehicular ad hoc network; the
model will describe the movement of vehicles from one network to other network.
The proposed handover scheme reduces the handover latency, packet loss
signaling overhead.


title:
The FMOS-Cosmos Survey of Star-Forming Galaxies at z~1.6 II. The
  Mass-Metallicity Relation and the Dependence on Star Formation Rate and Dust
  Extinction

abstract:
  We investigate the relationships between stellar mass, gas-phase oxygen
abundance (metallicity), star formation rate, and dust content of star-forming
galaxies at z$\sim$1.6 using Subaru/FMOS spectroscopy in the COSMOS field. The
mass-metallicity relation at $z\sim1.6$ is steeper than the relation observed
in the local Universe. The steeper MZ relation at $z\sim1.6$ is mainly due to
evolution in the stellar mass where the MZ relation begins to turnover and
flatten. This turnover mass is 1.2 dex larger at $z\sim1.6$. The most massive
galaxies at $z\sim1.6$ ($\sim 10^{11}M_\odot$) are enriched to the level
observed in massive galaxies in the local Universe. The mass-metallicity
relation we measure at $z\sim1.6$ supports the suggestion of an empirical upper
metallicity limit that does not significantly evolve with redshift. We find an
anti-correlation between metallicity and star formation rate for galaxies at a
fixed stellar mass at $z\sim1.6$ which is similar to trends observed in the
local Universe. We do not find a relation between stellar mass, metallicity and
star formation rate that is independent of redshift; our data suggest that
there is redshift evolution in this relation. We examine the relation between
stellar mass, metallicity and dust extinction. We find that at a fixed stellar
mass dustier galaxies tend to be more metal rich. From examination of the
stellar masses, metallicities, SFRs and dust extinctions we conclude that
stellar mass is most closely related to dust extinction.


title:
Coupled jet-disk model for Sgr A*: explaining the flat-spectrum radio
  core with GRMHD simulations of jets

abstract:
  The supermassive black hole in the center of the Milky Way, Sgr A*, displays
a nearly flat radio spectrum that is typical for jets in active galactic
nuclei. Indeed, time-dependent magnetized models of radiatively inefficient
accretion flows (RIAFs), which are commonly used to explain the millimeter,
near-infrared, and X-ray emission of Sgr A*, often also produce jet-like
outflows. However, the emission from these models has so far failed to
reproduce the flat radio spectrum. Aims: We investigate whether current
accretion simulations can produce the compact flat spectrum emission by simply
using a different prescription for the heating of the radiating particles in
the jet. Methods: We studied the radiative properties of accretion flows onto a
black hole produced in time-dependent general-relativistic magnetohydrodynamic
(GRMHD) simulations. A crucial free parameter in these models has always been
the electron temperature, and here we allowed for variations in the
proton-to-electron temperature ratios in the jet and disk. Results: We found
that the flat spectrum is readily reproduced by a standard GRMHD model if one
has an almost isothermal jet coupled to a two-temperature accretion flow. The
low-frequency radio mission comes from the outflowing sheath of matter
surrounding the strongly magnetized nearly empty jet. The model is consistent
with the radio sizes and spectrum of Sgr A*. Conclusions: Hence, GRMHD models
of accreting black holes can in principle naturally reproduce jets that match
observed characteristics. For Sgr A* the model fit to the spectrum predicts
higher mass-accretion rates when a jet is included than without a jet. Hence,
the impact of the recently discovered G2 cloud that is expected to be accreted
onto Sgr A* might be less severe than currently thought.


title: Structures and Numerical Ranges of Power Partial Isometries

abstract:
  We derive a matrix model, under unitary similarity, of an $n$-by-$n$ matrix
$A$ such that $A, A^2, \ldots, A^k$ ($k\ge 1$) are all partial isometries,
which generalizes the known fact that if $A$ is a partial isometry, then it is
unitarily similar to a matrix of the form ${\scriptsize\left[\begin{array}{cc}
0 & B 0 & C\end{array}\right]}$ with $B^*B+C^*C=I$. Using this model, we show
that if $A$ has ascent $k$ and $A, A^2, \ldots, A^{k-1}$ are partial
isometries, then the numerical range $W(A)$ of $A$ is a circular disc centered
at the origin if and only if $A$ is unitarily similar to a direct sum of Jordan
blocks whose largest size is $k$. As an application, this yields that, for any
$S_n$-matrix $A$, $W(A)$ (resp., $W(A\otimes A)$) is a circular disc centered
at the origin if and only if $A$ is unitarily similar to the Jordan block
$J_n$. Finally, examples are given to show that the conditions that $W(A)$ and
$W(A\otimes A)$ are circular discs at 0 are independent of each other for a
general matrix $A$.


title:
Policy iteration for perfect information stochastic mean payoff games
  with bounded first return times is strongly polynomial

abstract:
  Recent results of Ye and Hansen, Miltersen and Zwick show that policy
iteration for one or two player (perfect information) zero-sum stochastic
games, restricted to instances with a fixed discount rate, is strongly
polynomial. We show that policy iteration for mean-payoff zero-sum stochastic
games is also strongly polynomial when restricted to instances with bounded
first mean return time to a given state. The proof is based on methods of
nonlinear Perron-Frobenius theory, allowing us to reduce the mean-payoff
problem to a discounted problem with state dependent discount rate. Our
analysis also shows that policy iteration remains strongly polynomial for
discounted problems in which the discount rate can be state dependent (and even
negative) at certain states, provided that the spectral radii of the
nonnegative matrices associated to all strategies are bounded from above by a
fixed constant strictly less than 1.


title: Compressed Vertical Partitioning for Full-In-Memory RDF Management

abstract:
  The Web of Data has been gaining momentum and this leads to increasingly
publish more semi-structured datasets following the RDF model, based on atomic
triple units of subject, predicate, and object. Although it is a simple model,
compression methods become necessary because datasets are increasingly larger
and various scalability issues arise around their organization and storage.
This requirement is more restrictive in RDF stores because efficient SPARQL
resolution on the compressed RDF datasets is also required.
  This article introduces a novel RDF indexing technique (called k2-triples)
supporting efficient SPARQL resolution in compressed space. k2-triples, uses
the predicate to vertically partition the dataset into disjoint subsets of
pairs (subject, object), one per predicate. These subsets are represented as
binary matrices in which 1-bits mean that the corresponding triple exists in
the dataset. This model results in very sparse matrices, which are efficiently
compressed using k2-trees. We enhance this model with two compact indexes
listing the predicates related to each different subject and object, in order
to address the specific weaknesses of vertically partitioned representations.
The resulting technique not only achieves by far the most compressed
representations, but also the best overall performance for RDF retrieval in our
experiments. Our approach uses up to 10 times less space than a state of the
art baseline, and outperforms its performance by several order of magnitude on
the most basic query patterns. In addition, we optimize traditional join
algorithms on k2-triples and define a novel one leveraging its specific
features. Our experimental results show that our technique overcomes
traditional vertical partitioning for join resolution, reporting the best
numbers for joins in which the non-joined nodes are provided, and being
competitive in the majority of the cases.


title:
On exponential functionals, harmonic potential measures and undershoots
  of subordinators

abstract:
  We establish a link between the distribution of an exponential functional I
and the undershoots of a subordinator, which is given in terms of the
associated harmonic potential measure. This allows us to give a necessary and
sufficient condition in terms of the L\'evy measure for the exponential
functional to be multiplicative infinitely divisible. We then provide a formula
for the moment generating function of an exponential functional $I$ and the so
called remainder random variable $R$ associated to it. We provide a realization
of the remainder random variable $R$ as an infinite product involving
independent last position random variables of the subordinator. Some properties
of harmonic measures are obtained and some examples are provided.


title:
On the Uncertainty of the Ordering of Nonlocal Wavefunction Collapse
  when Relativity is Considered

abstract:
  The temporal measurement order and therefore the originator of the
instantaneous collapse of the wavefunction of a spatiality entangled particle
pair can change depending on the reference frame of an observer. This can lead
to a paradox in which its seems that both measurements collapsed the
wavefunction before the other. We resolve this paradox by demonstrating how
attempting to determine the order of measurement of the entangled pair
introduces uncertainty which makes the measurement order impossible to know.


title: Nonlocality in string theory

abstract:
  We discuss an aspect of string theory which has been tackled from many
different perspectives, but incompletely: the role of nonlocality in the theory
and its relation to the geometric shape of the string. In particular, we will
describe in quantitative terms how one can zoom out from an extended object
such as the string in such a way that, at sufficiently large scales, it appears
structureless. Since there are no free parameters in free-string theory, the
notion of large scales will be unambiguously determined. In other words, we
will be able to answer the question: How and at which scale can the string be
seen as a particle? In doing so, we will employ the concept of spectral
dimension in a new way with respect to its usual applications in quantum
gravity. The operational notions of worldsheet and target spacetime dimension
in string theory are also clarified and found to be in mutual agreement.


title: K pi scattering in moving frames

abstract:
  We extend our study of the $K\pi$ system to moving frames and present an
exploratory extraction of the masses and widths for the $K^*$ resonances by
simulating $K\pi$ scattering in p-wave with $I=1/2$ on the lattice. Using
$K\pi$ systems with non-vanishing total momenta allows the extraction of phase
shifts at several values of $K\pi$ relative momenta. A Breit-Wigner fit of the
phase renders a $K^*(892)$ resonance mass and $K^*\to K \pi $ coupling
compatible with the experimental numbers. We also determine the $K^*(1410)$
mass assuming the experimental $K^*(1410)$ width. We contrast the resonant
$I=1/2$ channel with the repulsive non-resonant $I=3/2$ channel, where the
phase is found to be negative and small, in agreement with experiment.


title: Quantum-enhanced metrology for multiple phase estimation with noise

abstract:
  We present a general framework to study the simultaneous estimation of
multiple phases in the presence of noise as a discretized model for phase
imaging. This approach can lead to nontrivial bounds of the precision for
multiphase estimation. Our results show that simultaneous estimation (SE) of
multiple phases is always better than individual estimation (IE) of each phase
even in noisy environment. However with $d$ being the number of phases, the
$O(d)$ advantage in the variance of the estimation, with which SE outperforms
IE schemes for noiseless processes, may disappear asymptotically. When noise is
low, those bounds recover the Heisenberg scale with the $O(d)$ advantage. The
utility of the bound of multiple phase estimation for photon loss channels is
exemplified.


title:
Quark-hadron phase transition in a three flavor PNJL model for
  interacting quarks

abstract:
  We extend our previous study of the quark-hadron phase transition at finite
temperatures with zero net baryon density by two flavor Nambu-Jona-Lasinio
model with Polyakov loop to the three flavor case in a scheme which
incorporates flavor nonet pseudo scalar and scalar mesonic correlations on
equal footing. The role of the axial U(1) breaking Kobayashi-Maskawa-'t Hooft
interaction on the low-lying thermal excitations is examined. At low
temperatures, only mesonic correlations, mainly due to low mass mesonic
collective excitations, pions and kaons, dominate the pressure while thermal
excitations of quarks are suppressed by the Polyakov loop. As temperature
increases, kaons and pions melt into the continuum of quark and anti-quark
excitations successively so that hadronic phase changes continuously to the
quark phase where quark excitations dominate pressure together with gluon
pressure coming from the effective potential for the Polyakov loop. Since we
introduce mesons as not elementary fields but auxiliary fields made from
quarks, we can describe the phase transition between hadronic phase and quark
phase in a unified fashion.


title:
Phase diagram of spin-$\frac 12$ quantum Heisenberg $J_1-J_2$
  antiferromagnet on the body-centered-cubic lattice in random phase
  approximation

abstract:
  Magnetic properties of spin $\frac 12$ $J_1-J_2$ Heisenberg antiferromagnet
on body centered cubic lattice are investigated. By using two-time temperature
Green's functions, sublattice magnetization and critical temperature depending
on the frustration ratio $p=J_2/J_1$ are obtained in both stripe and N\'eel
phase. The analysis of ground state sublattice magnetization and phase diagram
indicates the critical end point at $J_2/J_1 =0.714$, in agreement with
previous studies.


title: A New Dynamic Pricing Model based on Convex Hull Pricing

abstract:
  This paper presents a new dynamic pricing model (a.k.a. real-time pricing)
that reflects startup costs of generators. Dynamic pricing, which is a method
to control demand by pricing electricity at hourly (or more often) intervals,
has been studied by many researchers. They assume that the cost functions of
suppliers are convex, although they may be nonconvex because of the startup
costs of generators in practice. We provide a dynamic pricing model that takes
into account such cost functions within the settings of unit commitment
problems (UCPs). Our model gives convex hull price (CHP), which has not been
used in the context of dynamic pricing, though it is known that the CHP
minimizes the uplift payment which is disadvantageous to suppliers for a given
demand. In addition, we apply an iterative algorithm based on the subgradient
method to solve our model. Numerical experiments show the efficiency of our
model on reducing uplift payments. The prices determined by our algorithm give
sufficiently small uplift payments in a realistic computational time.


title: Casimir Friction for Media of Finite Density

abstract:
  This work is a continuation of our papers from the last couple of years on
the Casimir friction for a pair of particles at low relative velocity. The new
element in the present analysis is to allow the media to be dense. Then the
situation becomes more complex due to induced dipolar correlations, both within
the two planes, and between the planes. We show that the structure of the
problem can be simplified by regarding the two plates to be a generalized
version of a pair of particles. The force is predicted to be very small, far
beyond what is practically measurable.


title:
GHz Operation of Nanometer-Scale Metallic Memristors: Highly Transparent
  Conductance Channels in Ag$_{2}$S Devices

abstract:
  The nonlinear transport properties of nanometer-scale junctions formed
between an inert metallic tip and an Ag film covered by a thin Ag$_{2}$S layer
are investigated. Suitably prepared samples exhibit memristive behavior with
technologically optimal ON and OFF state resistances yielding to resistive
switching on the nanosecond time scale. Utilizing point contact Andreev
reflection spectroscopy we studied the nature of electron transport in the
active volume of the memristive junctions showing that both the ON and OFF
states correspond to truly nanometer scale, highly transparent metallic
channels. Our results demonstrate the merits of Ag$_{2}$S nanojunctions as
nanometer-scale memory cells with GHz operation frequencies.


title:
Determining the Higgs spin and parity in the di-photon decay channel
  using gluon polarization

abstract:
  Gluons inside an unpolarized proton are in general linearly polarized. This
polarization can, in principle, be used to determine the spin and parity of the
newly found Higgs-like boson at the LHC. We focus here on the calculation of
the degree of polarization.


title:
Journal Maps, Interactive Overlays, and the Measurement of
  Interdisciplinarity on the Basis of Scopus Data (1996-2012)

abstract:
  Using Scopus data, we construct a global map of science based on aggregated
journal-journal citations from 1996-2012 (N of journals = 20,554). This base
map enables users to overlay downloads from Scopus interactively. Using a
single year (e.g., 2012), results can be compared with mappings based on the
Journal Citation Reports at the Web-of-Science (N = 10,936). The Scopus maps
are more detailed at both the local and global levels because of their greater
coverage, including, for example, the arts and humanities. The base maps can be
interactively overlaid with journal distributions in sets downloaded from
Scopus, for example, for the purpose of portfolio analysis. Rao-Stirling
diversity can be used as a measure of interdisciplinarity in the sets under
study. Maps at the global and the local level, however, can be very different
because of the different levels of aggregation involved. Two journals, for
example, can both belong to the humanities in the global map, but participate
in different specialty structures locally. The base map and interactive tools
are available online (with instructions) at
http://www.leydesdorff.net/scopus_ovl.


title:
Bloch oscillations and quench dynamics of interacting bosons in an
  optical lattice

abstract:
  We study the dynamics of interacting superfluid bosons in a one dimensional
vertical optical lattice after a sudden increase of the lattice potential
depth. We show that this system can be exploited to investigate the effects of
strong interactions on Bloch oscillations. We perform theoretical modelling of
this system, identify experimental challenges and explore a new regime of Bloch
oscillations characterized by interaction-induced matter-wave collapse and
revivals which modify the Bloch oscillations dynamics. In addition, we study
three dephasing mechanisms: effective three-body interactions, finite value of
tunneling, and a background harmonic potential. We also find that the center of
mass motion in the presence of finite tunneling goes through collapse and
revivals, giving an example of quantum transport where interaction induced
revivals are important. We quantify the effects of residual harmonic trapping
on the momentum distribution dynamics and show the occurrence of
interaction-modified temporal Talbot effect. Finally, we analyze the prospects
and challenges of exploiting Bloch oscillations of cold atoms in the strongly
interacting regime for precision measurement of the gravitational acceleration
$g$.


title:
The radio remnant of Supernova 1987A at high frequencies and high
  resolution

abstract:
  As the remnant of Supernova (SN) 1987A has been getting brighter over time,
new observations at high frequencies have allowed imaging of the radio emission
at unprecedented detail. We present a new radio image at 44 GHz of the
supernova remnant (SNR), derived from observations performed with the Australia
Telescope Compact Array (ATCA) in 2011. The diffraction-limited image has a
resolution of $349\times225$ mas, which is the highest achieved to date in
high-dynamic range images of the SNR. We also present a new image at 18 GHz,
also derived from ATCA observations performed in 2011, which is super-resolved
to $0./!/!^{\prime\prime}25$. The new 44 and 18 GHz images yield the first
high-resolution spectral index map of the remnant. The comparison of the 44 GHz
image with contemporaneous X-ray and H$\alpha$ observations allows further
investigations of the nature of the remnant asymmetry and sheds more light into
the progenitor hypotheses and SN explosion. In light of simple free-free
absorption models, we discuss the likelihood of detecting at 44 GHz the
possible emission originating from a pulsar wind nebula (PWN) or a compact
source in the centre of the remnant.


title:
NMR study of electronic correlations in Mn-doped Ba(Fe1-xCox)2As2 and
  BaFe(As1-xPx)2

abstract:
  We probe the real space electronic response to a local magnetic impurity in
isovalent and heterovalent doped BaFe2As2 (122) using Nuclear Magnetic
Resonance (NMR). The local moments carried by Mn impurities doped into
Ba(Fe1-xCox)2As2(Co-122) and BaFe(As1-xPx)2(P-122) at optimal doping induce a
spin polarization in the vicinity of the impurity. The amplitude, shape and
extension of this polarisation is given by the real part of the susceptibility
chi'(r) of FeAs layers, and is consequently related to the nature and strength
of the electronic correlations present in the system. We study this
polarisation using 75As NMR in Co-122 and both 75As and 31P NMR in P-122. The
NMR spectra of Mn-doped materials is made of two essential features. First is a
satellite line associated with nuclei located as nearest neighbor of Mn
impurities. The analysis of the temperature dependence of the shift of this
satellite line shows that Mn local moments behave as isolated Curie moments.
The second feature is a temperature dependent broadening of the central line.
We show that the broadening of the central line follows the susceptibility of
Mn local moments, as expected from typical RKKY-like interactions. This
demonstrates that the susceptibility chi'(r) of FeAs layers does not make
significant contribution to the temperature dependent broadening of the central
line. chi'(r) is consequently only weakly temperature dependent in optimally
doped Co-122 and P-122. This behaviour is in contrast with that of strongly
correlated materials such as underdoped cuprate high-Tc superconductors where
the central line broadens faster than the impurity susceptibility grows,
because of the development of strong magnetic correlations when T is lowered.
Moreover, the FeAs layer susceptibility is found quantitatively similar in both
heterovalent doped and isolvalent doped BaFe2As2.


title: A temporal steering inequality

abstract:
  Quantum steering is the ability to remotely prepare different quantum states
by using entangled pairs as a resource. Very recently, the concept of steering
has been quantified with the use of inequalities, leading to substantial
applications in quantum information and communication science. Here, we
highlight that there exists a natural temporal analogue of the steering
inequality when considering measurements on a single object at different times.
We give non-trivial operational meaning to violations of this temporal
inequality by showing that it is connected to the security bound in the BB84
protocol and thus may have applications in quantum communication.


title:
Optimal rigidity estimates for nearly umbilical surfaces in arbitrary
  codimension

abstract:
  In [dLMu05], DeLellis and M\"uller proved a quantitative version of Codazzi's
theorem, namely for a smooth embedded surface $\ \Sigma \subseteq \mathbb{R}^3\
$ with area normalized to $\ {\cal H}^2(\Sigma) = 4 \pi\ $, it was shown that
$\ \parallel A_\Sigma - id \parallel_{L^2(\Sigma)} \leq C \parallel A^0_\Sigma
\parallel_{L^2(\Sigma)}\ $, and building on this, closeness of $\ \Sigma\ $ to
a round sphere in $\ W^{2,2}\ $ was established, when $\ \parallel A^0_\Sigma
\parallel_{L^2(\Sigma)}\ $ is small. This was supplemented in [dLMu06] by
giving a conformal parametrization $\ S^2 \stackrel{\approx}{\longrightarrow}
\Sigma\ $ with small conformal factor in $\ L^\infty\ $, again when $\
\parallel A^0_\Sigma \parallel_{L^2(\Sigma)}\ $ is small. In this article, we
extend these results to arbitrary codimension. In contrast to [dLMu05], our
argument is not based on the equation of Mainardi-Codazzi, but instead uses the
monotonicity formula for varifolds.


title:
Point spread function of SDO/HMI and the effects of stray light
  correction on the apparent properties of solar surface phenomena

abstract:
  We present a PSF for SDO/HMI and discuss the effects of its removal on the
apparent properties of solar surface phenomena in HMI data. The PSF was
retrieved from observations of Venus in transit by matching it to the
convolution of a model of the venusian disc and solar background with a guess
PSF. Observations recorded near in time to the transit of Venus were corrected
for instrumental scattered light by the deconvolution with the PSF. Granulation
contrast in restored HMI data is greatly enhanced relative to the original data
and exhibit reasonable agreement with numerical simulations. Image restoration
enhanced the apparent intensity and pixel averaged magnetic field strength of
photospheric magnetic features significantly. For small-scale magnetic
features, restoration enhanced intensity contrast in the continuum and core of
the Fe I 617.3 nm line by a factor of 1.3, and the magnetogram signal by a
factor of 1.7. For sunspots and pores, the enhancement varied strongly within
and between features, being more acute for smaller features. Magnetic features
are also rendered smaller, as signal smeared onto the surrounding quiet Sun is
recovered. Image restoration increased the apparent amount of magnetic flux
above the noise floor by a factor of about 1.2, most of the gain coming from
the quiet Sun. Line-of-sight velocity due to granulation and supergranulation
is enhanced by a factor of 1.4 to 2.1, depending on position on the solar disc.
There are indications that the PSF varies across the FOV, with time and between
the two CCDs. However, all these variations were found to be relatively small,
such that the derived PSF can be applied to HMI data from both CCDs, over the
period examined without introducing significant error. Image restoration
affects the measured radiant, magnetic and dynamic properties of solar surface
phenomena sufficiently to significantly impact interpretation.