title:
The genomic impacts of drift and selection for hybrid performance in
  maize

abstract:
  Modern maize breeding relies upon selection in inbreeding populations to
improve the performance of cross-population hybrids. The United States
Department of Agriculture - Agricultural Research Service reciprocal recurrent
selection experiment between the Iowa Stiff Stalk Synthetic (BSSS) and the Iowa
Corn Borer Synthetic No. 1 (BSCB1) populations represents one of the longest
standing models of selection for hybrid performance. To investigate the genomic
impact of this selection program, we used the Illumina MaizeSNP50 high-density
SNP array to determine genotypes of progenitor lines and over 600 individuals
across multiple cycles of selection. Consistent with previous research (Messmer
et al., 1991; Labate et al., 1997; Hagdorn et al., 2003; Hinze et al., 2005),
we found that genetic diversity within each population steadily decreases, with
a corresponding increase in population structure. High marker density also
enabled the first view of haplotype ancestry, fixation and recombination within
this historic maize experiment. Extensive regions of haplotype fixation within
each population are visible in the pericentromeric regions, where large blocks
trace back to single founder inbreds. Simulation attributes most of the
observed reduction in genetic diversity to genetic drift. Signatures of
selection were difficult to observe in the background of this strong genetic
drift, but heterozygosity in each population has fallen more than expected.
Regions of haplotype fixation represent the most likely targets of selection,
but as observed in other germplasm selected for hybrid performance (Feng et
al., 2006), there is no overlap between the most likely targets of selection in
the two populations. We discuss how this pattern is likely to occur during
selection for hybrid performance, and how it poses challenges for dissecting
the impacts of modern breeding and selection on the maize genome.


title: Semisimplicity and rigidity of the Kontsevich-Zorich cocycle

abstract:
  We prove that invariant subbundles of the Kontsevich-Zorich cocycle respect
the Hodge structure. In particular, we establish a version of Deligne
semisimplicity in this context. This implies that invariant subbundles must
vary polynomially on affine manifolds. All results apply to tensor powers of
the cocycle and this implies that the measurable and real-analytic algebraic
hulls coincide.
  We also prove that affine manifolds parametrize Jacobians with non-trivial
endomorphisms. Typically a factor has real multiplication.
  The tools involve curvature properties of the Hodge bundles and estimates
from random walks. In the appendix, we explain how methods from ergodic theory
imply some of the global consequences of Schmid's work on variations of Hodge
structures. We also derive the Kontsevich-Forni formula using differential
geometry.


title:
Scalar, Electromagnetic and Gravitational Perturbations of Kerr-Newman
  Black Holes in the Slow-Rotation Limit

abstract:
  In Einstein-Maxwell theory, according to classic uniqueness theorems, the
most general stationary black-hole solution is the axisymmetric Kerr-Newman
metric, which is defined by three parameters: mass, spin and electric charge.
The radial and angular dependence of gravitational and electromagnetic
perturbations in the Kerr-Newman geometry do not seem to be separable. In this
paper we circumvent this problem by studying scalar, electromagnetic and
gravitational perturbations of Kerr-Newman black holes in the slow-rotation
limit. We extend (and provide details of) the analysis presented in a recent
Letter [arXiv:1304.1160]. Working at linear order in the spin, we present the
first detailed derivation of the axial and polar perturbation equations in the
gravito-electromagnetic case, and we compute the corresponding quasinormal
modes for any value of the electric charge. Our study is the first
self-consistent stability analysis of the Kerr-Newman metric, and in principle
it can be extended to any order in the small rotation parameter. We find
numerical evidence that the axial and polar sectors are isospectral at first
order in the spin, and speculate on the possible implications of this result.


title:
Global weak solution for a coupled compressible Navier-Stokes and
  Q-tensor system

abstract:
  In this paper, we study a coupled compressible Navier-Stokes/Q-tensor system
modeling the nematic liquid crystal flow in a three-dimensional bounded spatial
domain. The existence and long time dynamics of globally defined weak solutions
for the coupled system are established, using weak convergence methods,
compactness and interpolation arguments. The symmetry and traceless properties
of the Q-tensor play key roles in this process.


title: The transitive algebra problem has an affirmative answer

abstract:
  All the spaces considered are over $\bbc$. $Z$ represents any Banach space,
$L(Z)$ the space of all the bounded operators on $Z$, and $H$ any Hilbert
space. We will prove that for any unital proper weakly closed subalgebra
(upwcsa) $R\subsetneq L(Z)$, the algebra $R^\p=\{A^* \st A\in R\}$ has
nontrivial invariant subspaces (ntinvss). This solves in \lb particular, the
three most famous long standing open problems in operator theory, (1) the
transitive algebra problem, (2) the hyperinvariant subspace problem, and (3)
the invariant subspace problem. The transitive algebra problem was raised by R.
V. Kadison in 1955 and it asks if every upwcsa of $L(H)$ has ntinvss. This
proves also a conjecture of P. Enflo, that every operator on a reflexive space
has ntinvss and a conjecture of V. I. Lomonosov, that the adjoint of any Banach
space operator has ntinvss.


title:
Secure quantum bit commitment against empty promises. II. The density
  matrix

abstract:
  We further study the security of the quantum bit commitment (QBC) protocol we
previously proposed [Phys. Rev. A 74, 022332 (2006).], by analyzing the reduced
density matrix \rho_{b}^{B} which describes the quantum state at Bob's side
corresponding to Alice's committed bit b. It is shown that Alice will find
\rho_{0}^{B}\perp \rho_{1}^{B} while the protocol remains concealing to Bob. On
the contrary, the existing no-go theorem of unconditionally secure QBC is based
on the condition \rho_{0}^{B}\simeq \rho_{1}^{B}. Thus the specific cheating
strategy proposed in the no-go theorem does not necessarily applies to our
protocol.


title: Symmetry considerations on radiation damping

abstract:
  It is well known that a direct Lagrangian description of radiation damping is
still missing. In this paper we will use a specific approach of this problem
which is the standard way to treat the radiation damping problem. The
objectives here are to construct: a N=2 supersymmetric extension for the model
describing the radiation damping on the noncommutative plane with electric and
magnetic interactions; a dualization analysis of the original action; the
supercharge algebra and the total Hamiltonian for the system.


title:
On Schr\"odinger equations with periodic potentials and with nonperiodic
  nonlinearities

abstract:
  We consider the Schr\"{o}dinger equation $-\Delta u +V(x)u=f(x, u)$, where
$V$ is periodic and $f$ is non-periodic, 0 is a boundary point of the
continuous spectrum of $A:=-\Delta +V(x)$. We use M. Willem and W. M. Zou's
linking theorem and M. Schechter's method to establish an existence result for
this problem in weak superlinear cases. In a sense, we enrich a recent result
of M. Willem and W.M. Zou [M. Willem and W.M. Zou, On a Schr\"{o}dinger
Equation with Periodic Potential and Spectrum Point Zero,Indiana Univ. Math. J.
2003].


title:
Zeeman coupling and screening corrections to skyrmion excitations in
  graphene

abstract:
  At half filling of the fourfold degenerate Landau levels |n| \geq 1 in
graphene, the ground states are spin polarized quantum Hall states that support
spin skyrmion excitations for |n| =1,2,3. Working in the Hartree-Fock
approximation, we compute the excitation energy of an unbound spin
skyrmion-antiskyrmion excitation as a function of the Zeeman coupling strength
for these Landau levels. We find for both the bare and screened Coulomb
interactions that the spin skyrmion-antiskyrmion excitation energy is lower
than the excitation energy of an unbound spin 1/2 electron-hole pair in a
finite range of Zeeman coupling in Landau levels |n| =1,2,3. This range
decreases rapidly for increasing Landau level index and is extremely small for
|n| =3. For valley skyrmions which should be present at 1/4 and 3/4 fillings of
the Landau levels |n| =1,2,3, we show that screening corrections are more
important in the latter case. It follows that an unbound valley
skyrmion-antiskyrmion excitation has lower energy at 3/4 filling than at 1/4.
We compare our results with recent experiments on spin and valley skyrmion
excitations in graphene.


title:
Complexity of Manipulation, Bribery, and Campaign Management in Bucklin
  and Fallback Voting

abstract:
  A central theme in computational social choice is to study the extent to
which voting systems computationally resist manipulative attacks seeking to
influence the outcome of elections, such as manipulation (i.e., strategic
voting), control, and bribery. Bucklin and fallback voting are among the voting
systems with the broadest resistance (i.e., NP-hardness) to control attacks.
However, only little is known about their behavior regarding manipulation and
bribery attacks. We comprehensively investigate the computational resistance of
Bucklin and fallback voting for many of the common manipulation and bribery
scenarios; we also complement our discussion by considering several campaign
management problems for Bucklin and fallback.


title:
Hyperoctahedral Eulerian Idempotents, Hodge Decompositions, and Signed
  Graph Coloring Complexes

abstract:
  Phil Hanlon proved that the coefficients of the chromatic polynomial of a
graph G are equal (up to sign) to the dimensions of the summands in a
Hodge-type decomposition of the top homology of the coloring complex for G. We
prove a type B analogue of this result for chromatic polynomials of signed
graphs using hyperoctahedral Eulerian idempotents.


title:
Branching Rule Decomposition of Irreducible Level-1 E_6^(1)-modules with
  respect to F_4^(1)

abstract:
  It is well known that using the weight lattice of type $E_6$, $P$, and the
lattice construction for vertex operator algebras one can obtain all three
level 1 irreducible $\tilde{g}$-modules with $V_P = V^{\Lamba_0} \oplus
V^{\Lamba_1} \oplus V^{\Lamba_6}$. The Dynkin diagram of type $E_6$ has an
order 2 automorphism, $\tau$, which can be lifted to $\tilde{{\tau}}$, a Lie
algebra automorphism of $\tilde{g}$ of type $E_6^(1)$. The fixed points of
$\tilde{{\tau}}$ are a subalgebra $\tilde{a}$ of type $F_4^(1)$. The
automorphism $\tau$ lifts further to $\hat{{\tau}}$ a vertex operator algebra
automorphism of $V_P$.
  We investigate the branching rules, how these three modules for the affine
Lie algebra $\tilde{g}$ decompose as a direct sum of irreducible
$\tilde{a}$-modules. To complete the decomposition we use the Godard-Kent-Olive
coset construction which gives a $c = \frac{4}{5}$ module for the Virasoro
algebra on $V_P$ which commutes with $\tilde{a}$. We use the irreducible
modules for this coset Virasoro to give the space of highest weight vectors for
$\tilde{a}$ in each $V^{\Lamba_i}$. The character theory related to this
decomposition is examined and we make a connection to one of the famous
Ramanujan identities. This dissertation constructs coset Virasoro operators
$Y(\omg,z)$ by explicitly determining the generator $\omg$. We also give the
explicit highest weight vectors for each $Vir \otimes F_4^(1)$-module in the
decomposition of each $V^{\Lamba_i}$. This explicit work on determining highest
weight vectors gives some insight into the relationship to the Zamolodchikov
$W_3$-algebra.


title: Totally geodesic submanifolds of symmetric spaces, III

abstract:
  One purpose of this article is to establish a general method to determine
stability of totally geodesic submanifolds of symmetric spaces. The method is
used to determine the stability of the basic totally geodesic submanifolds
$M_+,M_-$ introduced and studied by Chen and Nagano in [Totally geodesic
submanifolds of symmetric spaces, II, Duke Math. J. 45 (1978), 405--425] as
minimal submanifolds. The other purpose is to establish a stability theorem for
minimal totally real submanifolds of K\"ahlerian manifolds.


title:
Improving Data Forwarding in Mobile Social Networks with Infrastructure
  Support: A Space-Crossing Community Approach

abstract:
  In this paper, we study two tightly coupled issues: space-crossing community
detection and its influence on data forwarding in Mobile Social Networks (MSNs)
by taking the hybrid underlying networks with infrastructure support into
consideration. The hybrid underlying network is composed of large numbers of
mobile users and a small portion of Access Points (APs). Because APs can
facilitate the communication among long-distance nodes, the concept of physical
proximity community can be extended to be one across the geographical space. In
this work, we first investigate a space-crossing community detection method for
MSNs. Based on the detection results, we design a novel data forwarding
algorithm SAAS (Social Attraction and AP Spreading), and show how to exploit
the space-crossing communities to improve the data forwarding efficiency. We
evaluate our SAAS algorithm on real-life data from MIT Reality Mining and UIM.
Results show that space-crossing community plays a positive role in data
forwarding in MSNs in terms of deliver ratio and delay. Based on this new type
of community, SAAS achieves a better performance than existing social
community-based data forwarding algorithms in practice, including Bubble Rap
and Nguyen's Routing algorithms.


title: Solar Sail: Materials and Space Environmental Effects

abstract:
  Theoretical aspects of a solar sail material degradation are presented when
the solar electromagnetic and corpuscular forms of radiation were considered as
sources of degradation. The analysis of the interaction of two components of
solar radiation, the electromagnetic radiation and radiation of low- and
high-energy electrons, protons, and helium ions emitted by the Sun with the
solar-sail materials is discussed. The physical processes of the interactions
of photons, electrons, protons and alpha-particles with sail material atoms and
nuclei, leading to the degradation and ionization of solar sail materials are
analyzed. The dependence of reflectivity and absorption for solar sail
materials on temperature and on wavelength of the electromagnetic spectrum of
solar radiation is investigated. It is shown that the temperature of a solar
sail increases approximately as T r^(-2/5), with the decrease of the
heliocentric distance r, when are taking into account the temperature
dependence of optical parameters of the solar sail material.


title:
Data Warehouse Success and Strategic Oriented Business Intelligence: A
  Theoretical Framework

abstract:
  With the proliferation of the data warehouses as supportive decision making
tools, organizations are increasingly looking forward for a complete data
warehouse success model that would manage the enormous amounts of growing data.
It is therefore important to measure the success of these massive projects.
While general IS success models have received great deals of attention, few
research has been conducted to assess the success of data warehouses for
strategic business intelligence purposes. The framework developed in this study
consists of the following nine measures: Vendors and Consultants, Management
Actions, System Quality, Information Quality, Data Warehouse Usage, Perceived
utility, Individual Decision Making Impact, Organizational Decision Making
Impact, and Corporate Strategic Goals Attainment.


title: Under-the-barrier electron-ion interaction during tunnel ionization

abstract:
  We consider tunnel ionization of an atom or molecule in a strong field within
an analytical treatment of the R-matrix method, in which an imaginary boundary
is set up inside the classically forbidden region that acts as a source of
ionized electrons. These electrons are then propagated in the semiclassical
approximation, and relying on a numerical solution of the inner region, which
is accessible using quantum chemical techniques, we describe the subsequent
evolution of the ionized electron and the ionic core.
  Importantly, we show that correlation interactions between the ionized
electrons and those left behind in the core can play a role during ionization,
and that interactions can occur while the electron is still inside the
classically forbidden region that enable tunnelling from channels normally
subject to far greater exponential suppression since they are subject to higher
and wider tunnelling barriers.
  This interaction can be described analytically using saddle-point methods
that find the dominant contributions to the temporal, spatial and momentum
integrals that make up the expressions for the ionization yield. However, these
methods yield results for the angular distributions of the ionized electron
that do not necessarily match experiment and which yield physically
unsatisfactory solutions.
  In this report we develop a formalism to evaluate these integrals exactly,
which yields more precise calculations of the angular distributions while at
the same time providing the language, in terms of exchange of angular momentum,
with which to understand their origins and their differences from previous
cases, thus giving an insight into the fundamental physics of the correlation
interaction process.


title: Optimizing the search for transiting planets in long time series

abstract:
  Context: Transit surveys, both ground- and space- based, have already
accumulated a large number of light curves that span several years. Aims: The
search for transiting planets in these long time series is computationally
intensive. We wish to optimize the search for both detection and computational
efficiencies. Methods: We assume that the searched systems can be well
described by Keplerian orbits. We then propagate the effects of different
system parameters to the detection parameters. Results: We show that the
frequency information content of the light curve is primarily determined by the
duty cycle of the transit signal, and thus the optimal frequency sampling is
found to be cubic and not linear. Further optimization is achieved by
considering duty-cycle dependent binning of the phased light curve. By using
the (standard) BLS one is either rather insensitive to long-period planets, or
less sensitive to short-period planets and computationally slower by a
significant factor of ~330 (for a 3yr long dataset). We also show how the
physical system parameters, such as the host star's size and mass, directly
affect transit detection. This understanding can then be used to optimize the
search for every star individually. Conclusions: By considering Keplerian
dynamics explicitly rather than implicitly one can optimally search the BLS
parameter space. The presented Optimal BLS enhances the detectability of both
very short and very long period planets while allowing such searches to be done
with much reduced resources and time. The Matlab/Octave source code for Optimal
BLS is made available.


title: How far does scientific community look back?

abstract:
  How does the published scientific literature used by scientific community?
Many previous studies make analysis on the static usage data. In this research,
we propose the concept of dynamic usage data. Based on the platform of
realtime.springer.com, we have been monitoring and recording the dynamic usage
data of Scientometrics articles round the clock. Our analysis find that papers
published in recent four years have many more downloads than papers published
four years ago. According to our quantitative calculation, papers down-loaded
on one day have an average lifetime of 4.1 years approximately. Classic papers
are still being downloaded frequently even long after their publication.
Additionally, we find that social media may reboot the attention of old
scientific literature in a short time.


title:
Multicategory Crowdsourcing Accounting for Plurality in Worker Skill and
  Intention, Task Difficulty, and Task Heterogeneity

abstract:
  Crowdsourcing allows to instantly recruit workers on the web to annotate
image, web page, or document databases. However, worker unreliability prevents
taking a workers responses at face value. Thus, responses from multiple workers
are typically aggregated to more reliably infer ground-truth answers. We study
two approaches for crowd aggregation on multicategory answer spaces stochastic
modeling based and deterministic objective function based. Our stochastic model
for answer generation plausibly captures the interplay between worker skills,
intentions, and task difficulties and allows us to model a broad range of
worker types. Our deterministic objective based approach does not assume a
model for worker response generation. Instead, it aims to maximize the average
aggregate confidence of weighted plurality crowd decision making. In both
approaches, we explicitly model the skill and intention of individual workers,
which is exploited for improved crowd aggregation. Our methods are applicable
in both unsupervised and semisupervised settings, and also when the batch of
tasks is heterogeneous. As observed experimentally, the proposed methods can
defeat tyranny of the masses, they are especially advantageous when there is a
minority of skilled workers amongst a large crowd of unskilled and malicious
workers.


title: M-Tensors and Nonsingular M-Tensors

abstract:
  The M-matrix is an important concept in matrix theory, and has many
applications. Recently, this concept has been extended to higher order tensors
[18]. In this paper, we establish some important properties of M-tensors and
nonsingular M-tensors. An M-tensor is a Z-tensor. We show that a Z-tensor is a
nonsingular M-tensor if and only if it is semi-positive. Thus, a nonsingular
M-tensor has all positive diagonal entries; and an M-tensor, regarding as the
limitation of a series of nonsingular M-tensors, has all nonnegative diagonal
entries. We introduce even-order monotone tensors and present their spectral
properties. In matrix theory, a Z-matrix is a nonsingular M-matrix if and only
if it is monotone. This is no longer true in the case of higher order tensors.
We show that an even-order monotone Z-tensor is an even-order nonsingular
M-tensor but not vice versa. An example of an even-order nontrivial monotone
Z-tensor is also given.


title:
A class of iterative methods for solving nonlinear equation with
  fourth-order convergence

abstract:
  In this paper we established a class of optimal fourth-order methods which is
obtained by existing third-order method for solving nonlinear equations for
simple roots by using weight functions. Some physical examples are given to
illustrate the efficiency and performance of our method.


title:
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries
  of the Universe

abstract:
  The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.

categories: hep-ex hep-ph physics.acc-ph physics.ins-det


title: Uniform extensions of layered semifields

abstract:
  In this paper we introduce a canonical method of constructing simple uniform
semifield extensions of uniform layered semifields introduced by Izhakian
Knebusch and Rowen in the paper 'Layered tropical mathematics'. Our
construction includes a decomposition of a uniform extension of a uniformly
layered (uniform) semifield to the bipotent semifield extension of its
$\nu$-values semifield and a cancellative semifields extension of its layers
(sorting) semifield. We give a characterization of these two types of
semifields extensions in the first two sections of the paper. The third section
glues the pieces together to form a theory for a uniform extension of a
uniformly layered semifield.


title: Bundling in brushes of directed and semiflexible polymers

abstract:
  We explore the effect of an attractive interaction between parallel-aligned
polymers, which are perpendicularly grafted on a substrate. Such an attractive
interaction could be due to, e.g., reversible cross-links. The competition
between permanent grafting favoring a homogeneous state of the polymer brush
and the attraction, which tends to induce in-plane collapse of the aligned
polymers, gives rise to an instability of the homogeneous phase to a bundled
state. In this latter state the in-plane translational symmetry is
spontaneously broken and the density is modulated with a finite wavelength,
which is set by the length scale of transverse fluctuations of the grafted
polymers. We analyze the instability for two models of aligned polymers:
directed polymers with a line tension and weakly bending chains with a bending
stiffness.


title: Saturable absorption in multi-core fiber couplers

abstract:
  The saturable absorption characteristics of two-, three-, and five-core
one-dimensional fiber coupler arrays and the seven-core hexagonal fiber coupler
array are investigated. It is shown that the performance of all these saturable
absorbers are comparable and not much is gained, if anything, by going from a
two-core nonlinear coupler geometry to a higher number of cores. This
observation is supported by the similarity of the saturable absorption curves,
as well as comparable pulse characteristics obtained from the simulation of a
generic mode-locked fiber laser cavity.


title: Uniquely Strongly Clean Triangular Matrix Rings

abstract:
  A ring $R$ is uniquely (strongly) clean provided that for any $a\in R$ there
exists a unique idempotent $e\in R \big(\in comm(a)\big)$ such that $a-e\in
U(R)$. Let $R$ be a uniquely bleached ring. We prove, in this note, that $R$ is
uniquely clean if and only if $R$ is abelian, and $T_n(R)$ is uniquely strongly
clean for all $n\geq 1$, if and only if $R$ is abelian, $T_n(R)$ is uniquely
strongly clean for some $n\geq 1$. In the commutative case, the more explicit
results are obtained. These also generalize the main theorems in [6] and [7],
and provide many new class of such rings.


title:
PRINCE: Privacy-Preserving Mechanisms for Influence Diffusion in Online
  Social Networks

abstract:
  This paper has been withdrawn by the author due to a crucial sign error in
equation 1. With the advance of online social networks, there has been
extensive research on how to spread influence in online social networks, and
many algorithms and models have been proposed. However, many fundamental
problems have also been overlooked. Among those, the most important problems
are the incentive aspect and the privacy aspect (eg, nodes' relationships) of
the influence propagation in online social networks. Bearing these defects in
mind, and incorporating the powerful tool from differential privacy, we propose
PRINCE, which is a series of \underline{PR}ivacy preserving mechanisms for
\underline{IN}fluen\underline{CE} diffusion in online social networks to solve
the problems. We not only theoretically prove many elegant properties of
PRINCE, but also implement PRINCE to evaluate its performance extensively. The
evaluation results show that PRINCE achieves good performances. To the best of
our knowledge, PRINCE is the first differentially private mechanism for
influence diffusion in online social networks.


title: Additive actions on projective hypersurfaces

abstract:
  By an additive action on a hypersurface H in the projective space P^{n+1} we
mean an effective action of a commutative unipotent group on P^{n+1} which
leaves H invariant and acts on H with an open orbit. Brendan Hassett and Yuri
Tschinkel have shown that actions of commutative unipotent groups on projective
spaces can be described in terms of local algebras with some additional data.
We prove that additive actions on projective hypersurfaces correspond to
invariant multilinear symmetric forms on local algebras. It allows us to obtain
explicit classification results for non-degenerate quadrics and quadrics of
corank one.


title:
Multi-command Chest Tactile Brain Computer Interface for Small Vehicle
  Robot Navigation

abstract:
  The presented study explores the extent to which tactile stimuli delivered to
five chest positions of a healthy user can serve as a platform for a brain
computer interface (BCI) that could be used in an interactive application such
as robotic vehicle operation. The five chest locations are used to evoke
tactile brain potential responses, thus defining a tactile brain computer
interface (tBCI). Experimental results with five subjects performing online
tBCI provide a validation of the chest location tBCI paradigm, while the
feasibility of the concept is illuminated through information-transfer rates.
Additionally an offline classification improvement with a linear SVM classifier
is presented through the case study.


title: Molten salts database for energy applications

abstract:
  The growing interest in energy applications of molten salts is justified by
several of their properties. Their possibilities of usage as a coolant, heat
transfer fluid or heat storage substrate, require thermo-hydrodynamic refined
calculations. Many researchers are using simulation techniques, such as
Computational Fluid Dynamics (CFD) for their projects or conceptual designs.
The aim of this work is providing a review of basic properties (density,
viscosity, thermal conductivity and heat capacity) of the most common and
referred salt mixtures. After checking data, tabulated and graphical outputs
are given in order to offer the most suitable available values to be used as
input parameters for other calculations or simulations. The reviewed values
show a general scattering in characterization, mainly in thermal properties.
This disagreement suggests that, in several cases, new studies must be started
(and even new measurement techniques should be developed) to obtain accurate
values.


title: ASTRI SST-2M Data Handling and Archiving System

abstract:
  The ASTRI project is the INAF (Italian National Institute for Astrophysics)
flagship project developed in the context of the Cherenkov Telescope Array
(CTA) international project. ASTRI is dedicated to the realization of the
prototype of a Cherenkov small-size dual-mirror telescope (SST-2M) and then to
the realization of a mini-array composed of a few of these units. The prototype
and all the necessary hardware devices are foreseen to be installed at the
Serra La Nave Observing Station (Catania, Italy) in 2014. The upcoming data
flow will be properly reduced by dedicated (online and offline) analysis
pipelines aimed at providing robust and reliable scientific results (signal
detection, sky maps, spectra and light curves) from the ASTRI silicon
photo-multipliers camera raw data. Furthermore, a flexible archiving system has
being conceived for the storage of all the acquired ASTRI (scientific,
calibration, housekeeping) data at different steps of the data reduction up to
the final scientific products. In this contribution we present the data
acquisition, the analysis pipeline and the archive architecture that will be in
use for the ASTRI SST prototype. In addition, the generalization of the data
management system to the case of a mini-array of ASTRI telescopes will be
discussed.


title:
A novel method based on the Tikhonov functional for non-negative
  solution of a system of linear equations with non-negative coefficients

abstract:
  We propose a novel method for a solution of a system of linear equations with
the non-negativity condition. The method is based on the Tikhonov functional
and has better accuracy and stability than other well-known algorithms.


title: QM theory of the thermal electron gyroradius

abstract:
  The average (thermal) gyroradius of charged particles is re-examined from a
quantum-mechanical point of view. The straight quantum-mechanical calculation
clearly reproduces its conventionally used random-mean-square (rms) expectation
value. The quasi-classical approach reproduces its mean expectation value as
well thus confirming the purely classical calculation. It shows that the
fluctuations in the gyroradius amount to 21.5% of its rms value. This
fluctuation is, however, within the usual $\sqrt{2}$-"freedom" range of choice
in the definition of the rms gyroradius respectively the mean thermal speed on
which the rms value is based, its correct (nonrelativistic) value $v_t^2=
2T_\perp/m_e$ and its simplified version $v_t^2=T_\perp/m_e$.


title: Topological Phase Transition without Gap Closing

abstract:
  Topological phase transition is accompanied with a change of topological
numbers. It has been believed that the gap closing and the breakdown of the
adiabaticity at the transition point is necessary in general. However, the gap
closing is not always needed to make the topological index ill-defined. In this
paper, we show that the states with different topological numbers can be
continuously connected \textit{without} gap closing in some cases, where the
symmetry of the system changes during the process. Here we propose the generic
principles how this is possible (impossible) by demonstrating various examples
such as 1D polyacetylene with the charge-density-wave order, 2D silicene with
the antiferromagnetic order, 2D silicene or quantum well made of HgTe with
superconducting proximity effects and 3D superconductor Cu doped
Bi$_{2}$Se$_{3}$. It is argued that such an unusual phenomenon can occur when
we detour around the gap closing point provided the connection of the
topological indices is lost along the detour path.


title: The absolute continuous spectrum of skew products of compact Lie groups

abstract:
  Let $X$ and $G$ be compact Lie groups, $F_1:X\to X$ the time-one map of a
$C^\infty$ measure-preserving flow, $\phi:X\to G$ a continuous function and
$\pi$ a finite-dimensional irreducible unitary representation of $G$. Then, we
prove that the skew products $$ T_\phi:X\times G\to X\times
G,\quad(x,g)\mapsto\big(F_1(x),g\;\phi(x)\big), $$ have purely absolutely
continuous spectrum in the subspace associated to $\pi$ if $\pi\circ\phi$ has a
Dini-continuous Lie derivative along the flow and if a matrix multiplication
operator related to the topological degree of $\pi\circ\phi$ has nonzero
determinant. This result provides a simple, but general, criterion for the
presence of an absolutely continuous component in the spectrum of skew products
of compact Lie groups. As an illustration, we consider the cases where $F_1$ is
an ergodic translation on $\T^d$ and $X\times G=\T^d\times\T^{d'}$, $X\times
G=\T^d\times\SU(2)$ and $X\times G=\T^d\times\U(2)$. Our proofs rely on recent
results on positive commutator methods for unitary operators.


title:
Bipolaronic blockade effect in quantum dots with negative charging
  energy

abstract:
  We investigate single-electron transport through quantum dots with negative
charging energy induced by a polaronic energy shift. For weak dot-lead tunnel
couplings, we demonstrate a bipolaronic blockade effect at low biases which
suppresses the oscillating linear conductance, while the conductance resonances
under large biases are enhanced. Novel conductance plateau develops when the
coupling asymmetry is introduced, with its height and width tuned by the
coupling strength and external magnetic field. It is further shown that the
amplitude ratio of magnetic-split conductance peaks changes from 3 to 1for
increasing coupling asymmetry. Though we demonstrate all these transport
phenomena in the low-order single-electron tunneling regime, they are already
strikingly different from the usual Coulomb blockade physics and are easy to
observe experimentally.


title:
A remark on the Donaldson-Futaki invariant for sequences of test
  configurations

abstract:
  In this note, we consider a sequence of test configurations compatible with a
Kaehler metric in $c_1(L)$ on a polarized algebraic manifold $(X,L)$. Then an
explicit formula for the Donaldson-Futaki invariant $F_1$ for the sequence will
be given.


title: Knowledge Representation for Robots through Human-Robot Interaction

abstract:
  The representation of the knowledge needed by a robot to perform complex
tasks is restricted by the limitations of perception. One possible way of
overcoming this situation and designing "knowledgeable" robots is to rely on
the interaction with the user. We propose a multi-modal interaction framework
that allows to effectively acquire knowledge about the environment where the
robot operates. In particular, in this paper we present a rich representation
framework that can be automatically built from the metric map annotated with
the indications provided by the user. Such a representation, allows then the
robot to ground complex referential expressions for motion commands and to
devise topological navigation plans to achieve the target locations.


title:
Persistence, permanence and global stability for an n-dimensional
  Nicholson system

abstract:
  For a Nicholson's blowflies system with patch structure and multiple discrete
delays, we analyze several features of the global asymptotic behavior of its
solutions. It is shown that if the spectral bound of the community matrix is
non-positive, then the population becomes extinct on each patch, whereas the
total population uniformly persists if the spectral bound is positive. Explicit
uniform lower and upper bounds for the asymptotic behavior of solutions are
also given. When the population uniformly persists, the existence of a unique
positive equilibrium is established, as well as a sharp criterion for its
absolute global asymptotic stability, improving results in the recent
literature. While our system is not cooperative, several sharp threshold-type
results about its dynamics are proven, even when the community matrix is
reducible, a case usually not treated in the literature.


title:
Quantum Fisher information of entangled coherent state in the presence
  of photon losses: exact solution

abstract:
  We investigate the performance of entangled coherent state for quantum
enhanced phase estimation. An exact analytical expression of quantum Fisher
information is derived to show the role of photon losses on the ultimate phase
sensitivity. We find a transition of the sensitivity from the Heisenberg
scaling to the classical scaling due to quantum decoherence of the photon
state. This quantum-classical transition is uniquely determined by the number
of photons being lost, instead of the number of incident photons or the photon
loss rate alone. Our results also reveal that a crossover of the sensitivity
between the entangled coherent state and the NOON state can occur even for very
small photon loss rate.

categories: quant-ph cond-mat.quant-gas physics.atom-ph physics.optics


title: Optical measurement of a fundamental constant with the dimension of time

abstract:
  We consider the concept of a rotating reference frame with the axis of
rotation at each point and the applicability of this concept to different areas
of physics. The transformation for the transition from the resting to rotating
frame is assumed to be non-Galilean. This transformation must contain a
constant with dimension of time. We analyze different possibilities of
experimental testing this constant in optics, as most suitable field for
measurements presently, and also in general relativity and quantum mechanics


title:
Effects of Compton Cooling on outflows in a Two Component Accretion Flow
  around a Black Hole: Results of a Coupled Monte Carlo-TVD Simulation

abstract:
  The effect of cooling on the outflow rate from an accretion disk around a
black hole is investigated using a coupled Monte Carlo Total Variation
Diminishing code. A correlation between the spectral states and the outflow
rates is found as a consequence.


title:
Evolution of the force distributions in jammed packings of soft
  particles

abstract:
  The evolution of the force distributions during the isotropic compression of
two dimensional packings of soft frictional particles is investigated
numerically. Regardless of the applied deformation, the normal contact force
distribution can be fitted by the product of a power-law, and a stretched
exponential, while the tangential force distribution is fitted well by a
Gaussian. With increasing strain, the asymptotic behavior at large forces does
not change, but both normal and tangential distributions exhibit a broadening,
even though, when scaled with the average forces, their widths decrease.
Furthermore, the distribution of friction mobilization is a decreasing function
of the mobilization, except for an increased probability of fully mobilized
contacts. The excess coordination number of the packings increases with the
applied strain, indicating that the more a packing is compressed the more
stable it becomes.


title: Unobstructed Hilbert modular deformation problems

abstract:
  Consider the semisimple mod p reduction of the Galois representation
associated to a Hilbert newform f by Carayol and Taylor. This paper discusses
how, under certain conditions on f, the universal ring for deformations of this
residual representation with fixed determinant is unobstructed for almost all
primes. We follow the approach of Weston, who carried out a similar program for
classical modular forms in 2004. As such, the problem essentially comes down to
verifying that various local invariants vanish at all places dividing p or the
level of the newform. We conclude with an explicit example illustrating how one
can in principle find a lower bound on p such that the universal ring for
deformations of the residual representation attached to f with fixed
determinant is unobstructed for all primes over p.


title:
Strong thermal fluctuations in cuprate superconductors in magnetic field
  above Tc

abstract:
  Recent measurements of fluctuation diamagnetism in high temperature
superconductors show distinct features above and below Tc, which can not be
explained by simple gaussian fluctuation theory. Self consistent calculation of
magnetization in layered high temperature superconductors, based on the
Ginzburg-Landau-Lawrence-Doniach model and including all Landau levels is
presented. The results agree well with the experimental data in wide region
around Tc, including both the vortex liquid below Tc and the normal state above
Tc. The gaussian fluctuation theory significantly over estimates the
diamagnetism for strong fluctuations. It is demonstrated that the intersection
point of magnetization curves appears in the region where the lowest Landau
level contribution dominates.


title: Bandlimited Lipschitz functions

abstract:
  We study the space of bandlimited Lipschitz functions in one variable. In
particular we provide a geometrical description of the natural interpolating
and sampling sequences for this space. We also find a description of the trace
of such functions to sequences of critical density in terms of a cancellation
condition.


title: Generalized matrix coefficients of Unitary Representations

abstract:
  This is an introductory note concerning the distribution vectors in a unitary
representation of a Lie group. We discuss the definition of matrix coefficients
associated with a pair of distributions and how one can compute them. Most of
the results are known to some expert, but missing in the literature.


title:
Measurement of the neutron electric to magnetic form factor ratio at Q2
  = 1.58 GeV2 using the reaction 3He(e,e'n)pp

abstract:
  A measurement of beam helicity asymmetries in the reaction 3He(e,e'n)pp has
been performed at the Mainz Microtron in quasielastic kinematics in order to
determine the electric to magnetic form factor ratio of the neutron, GEn/GMn,
at a four momentum transfer Q2 = 1.58 GeV2. Longitudinally polarized electrons
were scattered on a highly polarized 3He gas target. The scattered electrons
were detected with a high-resolution magnetic spectrometer, and the ejected
neutrons with a dedicated neutron detector composed of scintillator bars. To
reduce systematic errors data were taken for four different target polarization
orientations allowing the determination of GEn/GMn from a double ratio. We find
mu_n GEn/GMn = 0.250 +/- 0.058(stat.) +/- 0.017 (sys.).


title:
Nontrivial solutions for semilinear elliptic systems via Orlicz-Sobolev
  theory

abstract:
  In this paper, the semilinear elliptic systems with Dirichlet boundary value
are considered \begin{align} \left\{\begin{array}{ll}
  -\Delta v=f(u) & \mathrm{in}\ \Omega,
  -\Delta u=g(v) & \mathrm{in}\ \Omega, u=0, \ v=0 & \mathrm{on}\
\partial\Omega, \end{array} \right. \end{align}
  We extend the notion of subcritical growth from polynomial growth to
N-function growth. Under N-function growth, nontrivial solutions are obtained
via Orlicz-Sobolev spaces and variational methods. It's also noteworthy that
the nonlinear term $g(v)$ does not have to satisfy the usual
Ambrosetti-Rabinowitz condition. So, in a sense, we enrich recent results of D.
~G. de Figueiredo, J. ~M. do {\'O} and B. ~Ruf [D. ~G. de Figueiredo, J.M. do
{\'O}, B. ~Ruf, An {O}rlicz-space approach to superlinear elliptic systems, J.
Funct. Anal. 224 (2005) 471--496].


title: Hypergraphs with Zero Chromatic Threshold

abstract:
  Let F be an r-uniform hypergraph. The chromatic threshold of the family of
F-free, r-uniform hypergraphs is the infimum of all non-negative reals c such
that the subfamily of F-free, r-uniform hypergraphs H with minimum degree at
least $c \binom{|V(H)|}{r-1}$ has bounded chromatic number. The study of
chromatic thresholds of various graphs has a long history, beginning with the
early work of Erd\H{o}s-Simonovits. One interesting question, first proposed by
\L{}uczak-Thomass\'{e} and then solved by
Allen-B\"{o}ttcher-Griffiths-Kohayakawa-Morris, is the characterization of
graphs having zero chromatic threshold, in particular the fact that there are
graphs with non-zero Tur\'{a}n density that have zero chromatic threshold. In
this paper, we make progress on this problem for r-uniform hypergraphs, showing
that a large class of hypergraphs have zero chromatic threshold in addition to
exhibiting a family of constructions showing another large class of hypergraphs
have non-zero chromatic threshold. Our construction is based on a special
product of the Bollob\'as-Erd\H{o}s graph defined earlier by the authors.


title: On active and passive testing

abstract:
  Given a property of Boolean functions, what is the minimum number of queries
required to determine with high probability if an input function satisfies this
property or is "far" from satisfying it? This is a fundamental question in
Property Testing, where traditionally the testing algorithm is allowed to pick
its queries among the entire set of inputs. Balcan, Blais, Blum and Yang have
recently suggested to restrict the tester to take its queries from a smaller
random subset of polynomial size of the inputs. This model is called active
testing, and in the extreme case when the size of the set we can query from is
exactly the number of queries performed it is known as passive testing.
  We prove that passive or active testing of k-linear functions (that is, sums
of k variables among n over Z_2) requires Theta(k*log n) queries, assuming k is
not too large. This extends the case k=1, (that is, dictator functions),
analyzed by Balcan et. al.
  We also consider other classes of functions including low degree polynomials,
juntas, and partially symmetric functions. Our methods combine algebraic,
combinatorial, and probabilistic techniques, including the Talagrand
concentration inequality and the Erdos--Rado theorem on Delta-systems.


title: A Bit of Secrecy for Gaussian Source Compression

abstract:
  In this paper, the compression of an independent and identically distributed
Gaussian source sequence is studied in an unsecure network. Within a game
theoretic setting for a three-party noiseless communication network (sender
Alice, legitimate receiver Bob, and eavesdropper Eve), the problem of how to
efficiently compress a Gaussian source with limited secret key in order to
guarantee that Bob can reconstruct with high fidelity while preventing Eve from
estimating an accurate reconstruction is investigated. It is assumed that Alice
and Bob share a secret key with limited rate. Three scenarios are studied, in
which the eavesdropper ranges from weak to strong in terms of the causal side
information she has. It is shown that one bit of secret key per source symbol
is enough to achieve perfect secrecy performance in the Gaussian squared error
setting, and the information theoretic region is not optimized by joint
Gaussian random variables.


title:
Understanding coil-to-globule transition of polymers with the aid of a
  novel cluster analysis technique

abstract:
  In this article, a novel cluster analysis algorithm was employed in the study
of polymer coil to globule transition via single chain Monte Carlo simulations.
The algorithm, which has been recently applied in Molecular Dynamics
simulations of atomistic systems that tend to phase separate [arXiv: 1307.7366
[cond-mat.soft]], provides us with a convenient means to map out the dynamics
of "pearls" formation along the backbone chain together with extracting
meaningful quantitative information about their shape and size distribution.
Preliminary findings tend to favour a two-stage model of collapse kinetics,
although a more complicated picture emerges when looking at the details of
cluster formation along the chain.


title: Continuous-mode multi-photon filtering

abstract:
  The purpose of this paper is to derive filters for an arbitrary open quantum
system driven by a light wavepacket prepared in a continuous-mode multi-photon
state. A continuous-mode multi-photon state is a state of a travelling light
wavepacket that contains a definite number of photons and is characterised by a
temporal (or equivalently spectral) profile. After the interaction with the
system, the outgoing light can be monitored by means of homodyne detection or
photodetection. Filters for both measurement schemes are derived in this paper.
Unlike the vacuum or the coherent state case, the annihilation operator of the
light field acting on a multi-photon state changes the state by annihilating a
photon, and this makes the traditional filtering techniques inapplicable. To
circumvent this difficulty, we adopt a non-Markovian embedding technique
proposed in \cite{gough:2013} for the study of the single-photon filtering
problem. However, the multi-photon nature of the problem addressed in this
paper makes the study much more mathematically involved. Moreover, as
demonstrated by an example --- a two-level system driven by a continuous-mode
two-photon state, multi-photon filters can reveal interesting strong nonlinear
optical phenomena absent in both the single-photon state case and the
continuous-mode Fock state case.


title:
Universal scaling at non-thermal fixed points of a two-component Bose
  gas

abstract:
  Quasi-stationary far-from-equilibrium critical states of a two-component Bose
gas are studied in two spatial dimensions. After the system has undergone an
initial dynamical instability it approaches a non-thermal fixed point. At this
critical point the structure of the gas is characterised by ensembles of
(quasi-)topological defects such as vortices, skyrmions and solitons which give
rise to universal power-law behaviour of momentum correlation functions. The
resulting power-law spectra can be interpreted in terms of
strong-wave-turbulence cascades driven by particle transport into
long-wave-length excitations. Scaling exponents are determined on both sides of
the miscible-immiscible transition controlled by the ratio of the intra-species
to inter-species couplings. Making use of quantum turbulence methods, we
explain the specific values of the exponents from the presence of transient
(quasi-)topological defects.

categories: cond-mat.quant-gas cond-mat.stat-mech hep-ph physics.flu-dyn quant-ph


title: Optimal stabilization of a cycle in nonlinear discrete systems

abstract:
  A method of stabilizing 2-cycles in discrete dynamic systems by Delayed
Feedback Control is developed by using classic Harmonic Analysis.


title: Congruences for sequences analogous to Euler numbers

abstract:
  For a given real number $a$ we define the sequence $\{E_{n,a}\}$ by
$E_{0,a}=1$ and $E_{n,a}=-a\sum_{k=1}^{[n/2]}
  \binom n{2k}E_{n-2k,a}$ $(n\ge 1)$, where $[x]$ is the greatest integer not
exceeding $x$. Since $E_{n,1}=E_n$ is the n-th Euler number, $E_{n,a}$ can be
viewed as a natural generalization of Euler numbers. In this paper we deduce
some identities and an inversion formula involving $\{E_{n,a}\}$, and establish
congruences for $E_{2n,a}\mod{2^{{\rm ord}_2n+8}}$, $E_{2n,a}\pmod{3^{{\rm
ord}_3n+5}}$ and $E_{2n,a}\pmod{5^{{\rm ord}_5n+4}}$ provided that $a$ is a
nonzero integer, where ${\rm ord}_pn$ is the least nonnegative integer $\alpha$
such that $p^{\a}\mid n$ but $p^{\a+1}\nmid n$.


title: The impact of disorder on Dirac plasmon losses

abstract:
  Recent scattering-type scanning near-field optical spectroscopy (s-SNOM)
experiments on single-layer graphene have reported Dirac plasmon lifetimes that
are substantially shorter than the dc transport scattering time \tau_{tr}. We
highlight that the plasmon lifetime is fundamentally different from \tau_{tr}
since it is controlled by the imaginary part of the current-current linear
response function at finite momentum and frequency. We first present the
minimal theory of the extrinsic lifetime of Dirac plasmons due to scattering
against impurities. We then show that a very reasonable concentration of
charged impurities yields a plasmon damping rate which is in good agreement
with s-SNOM experimental results.


title:
Linking electromagnetic and gravitational radiation in coalescing binary
  neutron stars

abstract:
  We expand on our study of the gravitational and electromagnetic emissions
from the late stage of an inspiraling neutron star binary as presented in Ref.
\cite{Palenzuela:2013hu}. Interactions between the stellar magnetospheres,
driven by the extreme dynamics of the merger, can yield considerable outflows.
We study the gravitational and electromagnetic waves produced during the
inspiral and merger of a binary neutron star system using a full relativistic,
resistive MHD evolution code. We show that the interaction between the stellar
magnetospheres extracts kinetic energy from the system and powers radiative
Poynting flux and heat dissipation. These features depend strongly on the
configuration of the initial stellar magnetic moments. Our results indicate
that this power can strongly outshine pulsars in binaries and have a
distinctive angular and time-dependent pattern. Our discussion provides more
detail than Ref. \cite{Palenzuela:2013hu}, showing clear evidence of the
different effects taking place during the inspiral. Our simulations include a
few milliseconds after the actual merger and study the dynamics of the magnetic
fields during the formation of the hypermassive neutron star. We also briefly
discuss the possibility of observing such emissions.


title:
Single-reference high-precision mass measurement with a multi-reflection
  time-of-flight mass spectrograph

abstract:
  A multi-reflection time-of-flight mass spectrograph, competitive with Penning
trap mass spectrometers, has been built at RIKEN. We have performed a first
online mass measurement, using 8Li+ (T1/2 = 838 ms). A new analysis method has
been realized, with which, using only 12C+ references, the mass excess of 8Li
was accurately determined to be 20947.6(15)(34) keV (dm/m = 6.6 x 10-7). The
speed, precision and accuracy of this first online measurement exemplifies the
potential for using this new type of mass spectrograph for precision
measurements of short-lived nuclei.


title: Probing terahertz surface plasmon waves in graphene structures

abstract:
  Epitaxial graphene mesas and ribbons are investigated using terahertz (THz)
nearfield microscopy to probe surface plasmon excitation and THz transmission
properties on the sub-wavelength scale. The THz near-field images show
variation of graphene properties on a scale smaller than the wavelength, and
excitation of THz surface waves occurring at graphene edges, similar to that
observed at metallic edges. The Fresnel reflection at the substrate SiC/air
interface is also found to be altered by the presence of graphene ribbon
arrays, leading to either reduced or enhanced transmission of the THz wave
depending on the wave polarization and the ribbon width.


title: Flow-level performance of random wireless networks

abstract:
  We study the flow-level performance of random wireless networks. The
locations of base stations (BSs) follow a Poisson point process. The number and
positions of active users are dynamic. We associate a queue to each BS. The
performance and stability of a BS depend on its load. In some cases, the full
distribution of the load can be derived. Otherwise we derive formulas for the
first and second moments. Networks on the line and on the plane are considered.
Our model is generic enough to include features of recent wireless networks
such as 4G (LTE) networks. In dense networks, we show that the inter-cell
interference power becomes normally distributed, simplifying many computations.
Numerical experiments demonstrate that in cases of practical interest, the
loads distribution can be well approximated by a gamma distribution with known
mean and variance.


title: Multiversality

abstract:
  Valid ideas that physical reality is vastly larger than human perception of
it, and that the perceived part may not be representative of the whole, exist
on many levels and have a long history. After a brief general inventory of
those ideas and their implications, I consider the cosmological "multiverse"
much discussed in recent scientific literature. I review its theoretical and
(broadly) empirical motivations, and its disruptive implications for the
traditional program of fundamental physics. I discuss the inflationary axion
cosmology, which provides an example where firmly rooted, plausible ideas from
microphysics lead to a well-characterized "mini-multiverse" scenario, with
testable phenomenological consequences.

categories: hep-ph astro-ph.CO hep-th physics.hist-ph


title: Basic nets in the projective plane

abstract:
  The notion of basic net (called also basic polyhedron) on $S^2$ plays a
central role in Conway's approach to enumeration of knots and links in $S^3$.
Drobotukhina applied this approach for links in $RP^3$ using basic nets on
$RP^2$. By a result of Nakamoto, all basic nets on $S^2$ can be obtained from a
very explicit family of minimal basic nets (the nets $(2\times n)^*$, $n\ge3$,
in Conway's notation) by two local transformations. We prove a similar result
for basic nets in $RP^2$.
  We prove also that a graph on $RP^2$ is uniquely determined by its pull-back
on $S^3$ (the proof is based on Lefschetz fix point theorem).


title:
High Temperature Raman analysis of Hydrogen Phase IV from Molecular
  Dynamics

abstract:
  We extend our previous studies on phase IV of solid hydrogen by employing
larger cells and k-sampling. We show that uncorrelated hexagonal rotations in
the weakly bounded G"-layers are needed to account for the experimentally
measured Raman spectrum. In large simulations we find no evidence of proton
diffusion or layer fluctuations, which we believe are the result of finite size
effects. In calculations at higher pressures (above 400 GPa) we identify a new
possible candidate for phase IV. We, finally, proposed a revised phase diagram
based on our previous and present results.


title:
Dispersion and attenuation for an acoustic wave equation consistent with
  viscoelasticity

abstract:
  An acoustic wave equation for pressure accounting for viscoelastic
attenuation is derived from viscoelastic equations of motion. It differs
significantly from the equations proposed by Szabo. Dispersion and attenuation
associated with the viscoelastic wave equation is examined. The theory is
applied to three classes of viscoelastic models and to the linear attenuation
model.


title: Jacobi polynomials and SU(2,2)

abstract:
  A ladder structure of operators is presented for the Jacobi polynomials,
J_n^(a,b)(x), with parameters n, a and b integers, showing that they are
related to the unitary irreducible representation of SU(2,2) with quadratic
Casimir C_SU(2,2)=-3/2. As they determine also a base of square-integrable
functions, the universal enveloping algebra of su(2,2) is homomorphic to the
space of linear operators acting on the L^2 functions defined on (-1,+1) x Z x
Z/2.


title: Koszul property of diagonal subalgebras

abstract:
  Let S=K[x_1,...,x_n] be a polynomial ring over a field K and I a homogeneous
ideal in S generated by a regular sequence f_1,f_2,...,f_k of homogeneous forms
of degree d. We study a generalization of a result of Conca, Herzog, Trung, and
Valla [9] concerning Koszul property of the diagonal subalgebras associated to
I. Each such subalgebra has the form K[(I^e)_{ed+c}], where c and e are
positive integers. For k=3, we extend [9, Corollary 6.10] by proving that
K-algebra K[(I^e)_{ed+c}] is Koszul as soon as c >= d/2. We also extend [9,
Corollary 6.10] in another direction by replacing the polynomial ring with a
Koszul ring.


title: Learning Frames from Text with an Unsupervised Latent Variable Model

abstract:
  We develop a probabilistic latent-variable model to discover semantic
frames---types of events and their participants---from corpora. We present a
Dirichlet-multinomial model in which frames are latent categories that explain
the linking of verb-subject-object triples, given document-level sparsity. We
analyze what the model learns, and compare it to FrameNet, noting it learns
some novel and interesting frames. This document also contains a discussion of
inference issues, including concentration parameter learning; and a small-scale
error analysis of syntactic parsing accuracy.


title:
Measures of dependence between random vectors and tests of independence.
  Literature review

abstract:
  Simple correlation coefficients between two variables have been generalized
to measure association between two matrices in many ways. Coefficients such as
the RV coefficient, the distance covariance (dCov) coefficient and kernel based
coefficients have been adopted by different research communities. Scientists
use these coefficients to test whether two random vectors are linked. If they
are, it is important to uncover what patterns exist in these associations.
  We discuss the topic of measures of dependence between random vectors and
tests of independence and show links between different approaches. We document
some of the interesting rediscoveries and lack of interconnection between
bodies of literature. After providing definitions of the coefficients and
associated tests, we present the recent improvements that enhance their
statistical properties and ease of interpretation. We summarize multi-table
approaches and provide scenarii where the indices can provide useful summaries
of heterogeneous multi-block data.
  We illustrate these different strategies on several examples of real data and
suggest directions for future research.


title: Origin of Rashba-splitting in the quantized subbands at Bi2Se3 surface

abstract:
  We study the band structure of the $\text{Bi}_2\text{Se}_3$ topological
insulator (111) surface using angle-resolved photoemission spectroscopy. We
examine the situation where two sets of quantized subbands exhibiting different
Rashba spin-splitting are created via bending of the conduction (CB) and the
valence (VB) bands at the surface. While the CB subbands are strongly Rashba
spin-split, the VB subbands do not exhibit clear spin-splitting. We find that
CB and VB experience similar band bending magnitudes, which means, a
spin-splitting discrepancy due to different surface potential gradients can be
excluded. On the other hand, by comparing the experimental band structure to
first principles LMTO band structure calculations, we find that the strongly
spin-orbit coupled Bi 6$p$ orbitals dominate the orbital character of CB,
whereas their admixture to VB is rather small. The spin-splitting discrepancy
is, therefore, traced back to the difference in spin-orbit coupling between CB
and VB in the respective subbands' regions.


title: Some Perspectives on Network Modeling in Therapeutic Target Prediction

abstract:
  Drug target identification is of significant commercial interest to
pharmaceutical companies, and there is a vast amount of research done related
to the topic of therapeutic target identification. Interdisciplinary research
in this area involves both the biological network community and the graph
algorithms community. Key steps of a typical therapeutic target identification
problem include synthesizing or inferring the complex network of interactions
relevant to the disease, connecting this network to the disease-specific
behavior, and predicting which components are key mediators of the behavior.
All of these steps involve graph theoretical or graph algorithmic aspects. In
this perspective, we provide modelling and algorithmic perspectives for
therapeutic target identification and highlight a number of algorithmic
advances, which have gotten relatively little attention so far, with the hope
of strengthening the ties between these two research communities.


title:
Pore pressure development in small-strain undrained loading of soils
  according to a simple model

abstract:
  This note discusses a simple equation that may be useful in the study of pore
pressures generated in the undrained loading of soils. The equation is employed
to describe the pore pressure development accompanying a small stress increment
in the undrained triaxial compression test and in the undrained simple shear
test. The cases of incompressible and compressible pore fluids are examined.


title: The large cardinals between supercompact and almost-huge

abstract:
  I analyze the hierarchy of large cardinals between a supercompact cardinal
and an almost-huge cardinal. Many of these cardinals are defined by modifying
the definition of a high-jump cardinal. A high-jump cardinal is defined as the
critical point of an elementary embedding $j: V \to M$ such that $M$ is closed
under sequences of length $\sup\set{j(f)(\kappa) \st f: \kappa \to \kappa}$.
Some of the other cardinals analyzed include the super-high-jump cardinals,
almost-high-jump cardinals, Shelah-for-supercompactness cardinals,
Woodin-for-supercompactness cardinals, \Vopenka\ cardinals, hypercompact
cardinals, and enhanced supercompact cardinals. I organize these cardinals in
terms of consistency strength and implicational strength. I also analyze the
superstrong cardinals, which are weaker than supercompact cardinals but are
related to high-jump cardinals. Two of my most important results are as
follows. \begin{itemize} \item \Vopenka\ cardinals are the same as
Woodin-for-supercompactness cardinals. \item There are no excessively
hypercompact cardinals. \end{itemize} Furthermore, I prove some results
relating high-jump cardinals to forcing, as well as analyzing Laver functions
for super-high-jump cardinals. \keywords{high-jump cardinals \and \Vopenka\
cardinals \and Woodin-for-supercompactness cardinals \and hypercompact
cardinals \and forcing and large cardinals \and Laver functions}


title: Up- and Down-Quark Contributions to the Nucleon Form Factors

abstract:
  Recent measurements of the neutron's electric to magnetic form factors ratio,
R_n= \mu_n G_E^n/G_M^n, up to 3.4 (GeV/c)^2 combined with existing R_p= \mu_p
G_E^p/G_M^p measurements in the same Q^2 range allowed, for the first time, a
separation of the up- and down-quark contributions to the form factors at high
Q^2, as presented by Cates, et al. Our analysis expands on the original work by
including additional form factor data, applying two-photon exchange (TPE)
corrections, and accounting for the uncertainties associated with all of the
form factor measurements


title:
Complex scale-free networks with tunable power-law exponent and
  clustering

abstract:
  We introduce a network evolution process motivated by the network of
citations in the scientific literature. In each iteration of the process a node
is born and directed links are created from the new node to a set of target
nodes already in the network. This set includes $m$ "ambassador" nodes and $l$
of each ambassador's descendants where $m$ and $l$ are random variables
selected from any choice of distributions $p_{l}$ and $q_{m}$. The process
mimics the tendency of authors to cite varying numbers of papers included in
the bibliographies of the other papers they cite. We show that the degree
distributions of the networks generated after a large number of iterations are
scale-free and derive an expression for the power-law exponent. In a particular
case of the model where the number of ambassadors is always the constant $m$
and the number of selected descendants from each ambassador is the constant
$l$, the power-law exponent is $(2l+1)/l$. For this example we derive
expressions for the degree distribution and clustering coefficient in terms of
$l$ and $m$. We conclude that the proposed model can be tuned to have the same
power law exponent and clustering coefficient of a broad range of the
scale-free distributions that have been studied empirically.


title: Congruence successions in compositions

abstract:
  A \emph{composition} is a sequence of positive integers, called \emph{parts},
having a fixed sum. By an \emph{$m$-congruence succession}, we will mean a pair
of adjacent parts $x$ and $y$ within a composition such that $x\equiv
y(\text{mod} m)$. Here, we consider the problem of counting the compositions of
size $n$ according to the number of $m$-congruence successions, extending
recent results concerning successions on subsets and permutations. A general
formula is obtained, which reduces in the limiting case to the known generating
function formula for the number of Carlitz compositions. Special attention is
paid to the case $m=2$, where further enumerative results may be obtained by
means of combinatorial arguments. Finally, an asymptotic estimate is provided
for the number of compositions of size $n$ having no $m$-congruence
successions.


title:
Constraint damping of the conformal and covariant formulation of the Z4
  system in simulations of binary neutron stars

abstract:
  Following previous work in vacuum spacetimes, we investigate the
constraint-damping properties in the presence of matter of the recently
developed traceless, conformal and covariant Z4 (CCZ4) formulation of the
Einstein equations. First, we evolve an isolated neutron star with an ideal gas
equation of state and subject to a constraint-violating perturbation. We
compare the evolution of the constraints using the CCZ4 and
Baumgarte-Shibata-Shapiro-Nakamura-Oohara-Kojima (BSSNOK) systems. Second, we
study the collapse of an unstable spherical star to a black hole. Finally, we
evolve binary neutron star systems over several orbits until the merger, the
formation of a black hole, and up to the ringdown. We show that the CCZ4
formulation is stable in the presence of matter and that the constraint
violations are one or more orders of magnitude smaller than for the BSSNOK
formulation. Furthermore, by comparing the CCZ4 and the BSSNOK formulations
also for neutron star binaries with large initial constraint violations, we
investigate their influence on the errors on physical quantities. We also give
a new, simple and robust prescription for the damping parameter that removes
the instabilities found when using the fully covariant version of CCZ4 in the
evolution of black holes. Overall, we find that at essentially the same
computational costs the CCZ4 formulation provides solutions that are stable and
with a considerably smaller violation of the Hamiltonian constraint than the
BSSNOK formulation. We also find that the performance of the CCZ4 formulation
is very similar to another conformal and traceless, but noncovariant
formulation of the Z4 system, i.e. the Z4c formulation.


title: Analysis on Surreal Numbers

abstract:
  The class $\mathbf{No}$ of surreal numbers, which John Conway discovered
while studying combinatorial games, possesses a rich numerical structure and
shares many arithmetic and algebraic properties with the real numbers. Some
work has also been done to develop analysis on $\mathbf{No}$. In this paper, we
extend this work with a treatment of functions, limits, derivatives, power
series, and integrals.
  We propose surreal definitions of the arctangent and logarithm functions
using truncations of Maclaurin series. Using a new representation of surreals,
we present a formula for the limit of a sequence, and we use this formula to
provide a complete characterization of convergent sequences and to evaluate
certain series and infinite Riemann sums via extrapolation. A similar formula
allows us to evaluates limits (and hence derivatives) of functions.
  By defining a new topology on $\mathbf{No}$, we obtain the Intermediate Value
Theorem even though $\mathbf{No}$ is not Cauchy complete, and we prove that the
Fundamental Theorem of Calculus would hold for surreals if a consistent
definition of integration exists. Extending our study to defining other
analytic functions, evaluating power series in generality, finding a consistent
definition of integration, proving Stokes' Theorem to generalize surreal
integration, and studying differential equations remains open.


title: Stabilization of abstract thermo-elastic semigroup

abstract:
  In this paper we characterize the stabilization for some thermo-elastic type
system with Cattaneo law and we prove that the exponential or polynomial
stability of this system implies a polynomial stability of the correspond
thermoelastic system with the Fourier law. The proof of the main results uses,
respectively, the methodology introduced in Ammari and Tucsnak, where the
exponential stability for the closed loop problem is reduced to an
observability estimate for the corresponding uncontrolled system and a
characterization, of the polynomial stability for C0-semigroup in Hilbert space
by a polynomial estimation of the associated resolvante of the generator of
this semigroup, obtained by Borichev-Tomilov.


title: Optimal Rellich-Sobolev constants and their extremals

abstract:
  We prove that extremals for second order Rellich-Sobolev inequalities have
constant sign. Then we show that the optimal constants in Rellich-Sobolev
inequalities on a bounded domain {\Omega} and under Navier boundary conditions
do not depend on {\Omega}


title: A soothing invisible hand: moderation potentials in optimal control

abstract:
  A moderation incentive is a continuously differentiable control-dependent
cost term that is identically zero on the boundary of the admissible control
region, and is subtracted from the `do or die' cost function to reward
sub-maximal control utilization in optimal control systems. A moderation
potential is a function on the cotangent bundle of the state space such that
the solutions of Hamilton's equations satisfying appropriate boundary
conditions are solutions of the synthesis problem - the control-parametrized
Hamiltonian system central to Pontryagin's Maximum Principle. A multi-parameter
family of moderation incentives for affinely controlled systems with quadratic
control constraints possesses simple, readily calculated moderation potentials.
One member of this family is a shifted version of the kinetic energy-style
control cost term frequently used in geometric optimal control. The controls
determined by this family approach those determined by a logarithmic penalty
function as one of the parameters approaches zero, while the cost term itself
is bounded.


title: New Cataclysmic Variable 1RXS J161659.5+620014 in Draco

abstract:
  We report the discovery of a new cataclysmic variable MASTER OT
J161700.81+620024.9 which is identical to the faint ROSAT X-ray source 1RXS
J161659.5+620014. The object was observed in outbursts to 14.4m on 2012 Sep. 11
by MASTER-Tunka and to 14.3m on 2013 Jan. 21/22 by MASTER-Kislovodsk, but was
not detected by the routine search procedures. Analysis of the archival MASTER
data and CRTS light curve shows the variability from 17.8m at quiescence to
14.3m in outbursts, confirming that the new variable is a dwarf nova. SDSS
colors suggest a small contribution from the secondary component and are
telling in favor of the short orbital period.


title: Crystalline Geometries from Fermionic Vortex Lattice

abstract:
  We study charged Dirac fermions on an AdS$_2\times R^2$ background with a
non-zero magnetic field. Under certain boundary conditions, we show that the
charged fermion can make the background unstable, resulting in spontaneously
formation of a vortex lattice. We observe that an electric field emerges in the
back-reacted solution due to the vortex lattice constructed from spin polarized
fermions. This electric field may be extended to the UV boundary which leads to
a finite charge density. We also discuss corrections to the thermodynamic
functions due to the lattice formation.


title: ROSoClingo: A ROS package for ASP-based robot control

abstract:
  Knowledge representation and reasoning capacities are vital to cognitive
robotics because they provide higher level cognitive functions for reasoning
about actions, environments, goals, perception, etc. Although Answer Set
Programming (ASP) is well suited for modelling such functions, there was so far
no seamless way to use ASP in a robotic environment. We address this
shortcoming and show how a recently developed reactive ASP system can be
harnessed to provide appropriate reasoning capacities within a robotic system.
To be more precise, we furnish a package integrating the reactive ASP solver
oClingo with the popular open-source robotic middleware ROS. The resulting
system, ROSoClingo, provides a generic way by which an ASP program can be used
to control the behaviour of a robot and to respond to the results of the
robot's actions.


title: Nonflat time-variable dark energy cosmology

abstract:
  We generalize the time-variable dark energy scalar field $\Phi$ model
($\Phi$CDM) to nonflat space. We show that even in the
space-curvature-dominated epoch the scalar field solution is a time-dependent
fixed point or attractor, with scalar field energy density that grows relative
to the energy density in spatial curvature. This is the first example of a
physically consistent and complete model of dynamical dark energy in a nonflat
geometry.


title: Mollow triplet for cavity-mediated laser cooling

abstract:
  Here we analyse cavity-mediated laser cooling for an experimental setup with
an external trap which strongly confines the motion of a particle in the
direction of the cavity axis. It is shown that the stationary state phonon
number exhibits three sharp minima as a function of the atom-cavity detuning
due to a direct atom-phonon-photon coupling term in the system Hamiltonian.
These resonances have the same origin as the Mollow triplet in the resonance
fluorescence of a laser-driven atomic system. It is shown that a laser-Rabi
frequency-dependent atom-cavity detuning yields the lowest stationary state
phonon number for a wide range of experimental parameters.


title:
Properties of nonlinear noise in long, dispersion-uncompensated fiber
  links

abstract:
  We study the properties of nonlinear interference noise (NLIN) in fiber-optic
communications systems with large accumulated dispersion. Our focus is on
settling the discrepancy between the results of the Gaussian noise (GN) model
(according to which NLIN is additive Gaussian) and a recently published
time-domain analysis, which attributes drastically different properties to the
NLIN. Upon reviewing the two approaches we identify several unjustified
assumptions that are key in the derivation of the GN model, and that are
responsible for the discrepancy. We derive the true NLIN power and verify that
the NLIN is not additive Gaussian, but rather it depends strongly on the data
transmitted in the channel of interest. In addition we validate the time-domain
model numerically and demonstrate the strong dependence of the NLIN on the
interfering channels' modulation format.


title:
Novel multiferroics with ferromagnetic phase induced in paraelectric
  antiferromagnets by electric field application

abstract:
  The phase diagram of a quantum paraelectric antiferromagnet EuTiO3 under an
external electric field was calculated using Landau-Ginzburg-Devonshire theory.
It was shown that the application of an external electric field E leads to the
appearance of a ferromagnetic phase due to the magnetoelectric coupling. In
particular, electric field application decreases the transition temperature
TAFM to antiferromagnetic (AFM) phase and induces ferromagnetic (FM) phase, so
that at some E field larger than the critical field (Ecr), TFM becomes higher
than TAFM and the FM phase appears. Note that Ecr increases and magnetization
decreases as the temperature increases. The value of the critical field Ecr =
0.40*10^6 V/cm we calculated appeared close to the value Ecr = 0.5*10^6 V/cm
obtained recently by Ryan et al. with the help of density functional theory for
EuTiO3 film under a compressive strain produced by substrate. At the fields E
>0.83*10^6 V/cm, AFM disappears for all considered temperatures and so FM
becomes the only stable magnetic phase. We find that ferromagnetic phase can be
induced by an E-field in other paraelectric antiferromagnet oxides with a
positive AFM-type magnetoelectric (ME) coupling coefficient and negative
FM-type ME coupling coefficient. In particular, the critical E-field was
estimated for another paraelectric antiferromagnet Sr0.7Ba0.3MnO3 as
0.2x10^5V/cm at 0 K. Analysis of the dependence of magnetization and
antimagnetization on the external electric field and the polarization induced
by the field, which yields the magnetoelectric coupling, is reported. The
results show the possibility to control multiferroicity, including the FM and
AFM phases, with help of an electric field application.


title: NLO corrections to WWZ production at the LHC

abstract:
  The production of WWZ at the LHC is an important process to test the quartic
gauge couplings of the Standard Model as well as an important background for
new physics searches. A good theoretical understanding at next-to-leading order
(NLO) is therefore valuable. In this paper, we present the calculation of the
NLO electroweak (EW) correction to this channel with on-shell gauge bosons in
the final state. It is then combined with the NLO QCD correction to get the
most up-to-date prediction. We study the impact of these corrections on the
total cross section and some distributions. The NLO EW correction is small for
the total cross section but becomes important in the high energy regime for the
gauge boson transverse momentum distributions.


title: On the multiplicity of isometry-invariant geodesics on product manifolds

abstract:
  We prove that on any closed Riemannian manifold $(M_1\times M_2,g)$, with
$\rank\Hom_1(M_1)\neq0$ and $\dim(M_2)\geq2$, every isometry homotopic to the
identity admits infinitely many isometry-invariant geodesics.


title:
Reasoning for Moving Blocks Problem: Formal Representation and
  Implementation

abstract:
  The combined approach of the Qualitative Reasoning and Probabilistic
Functions for the knowledge representation is proposed. The method aims at
represent uncertain, qualitative knowledge that is essential for the moving
blocks task's execution. The attempt to formalize the commonsense knowledge is
performed with the Situation Calculus language for reasoning and robot's
beliefs representation. The method is implemented in the Prolog programming
language and tested for a specific simulated scenario. In most cases the
implementation enables us to solve a given task, i.e., move blocks to desired
positions. The example of robot's reasoning and main parts of the implemented
program's code are presented.


title:
A Second Detector Focusing on the Second Oscillation Maximum at an
  Off-axis Location to Enhance the Mass Hierarchy Discovery Potential in LBNE10

abstract:
  The Long Baseline Neutrino Oscillation Experiment (LBNE) is proposed to
determine the neutrino mass hierarchy and measure the CP phase in the leptonic
sector. The current design of LBNE Phase I consists of a 10 kt liquid argon
time projection chamber (LBNE10). The neutrino-antineutrino asymmetry in the
electron-neutrino appearance probability has contributions from both the CP
phase and the matter effect. For this reason, experimental sensitivity to the
mass hierarchy depends both on the true value of the CP phase and the true mass
hierarchy; LBNE10 will determine the mass hierarchy at high levels of
significance for half of CP phase space. We propose placing a second detector
at an off-axis location. Such a detector will share the same beamline as the
primary LBNE detector. The detector location is chosen such that this detector
focuses on a measurement of electron (anti-)neutrino appearance at the second
oscillation maximum. We will show that this configuration will enhance the
ability of LBNE to determine the mass hierarchy and to discover CP violation in
the leptonic sector.


title: First hyperbolic times for intermittent maps with unbounded derivative

abstract:
  We establish some statistical properties of the hyperbolic times for a class
of nonuniformly expanding dynamical systems. The maps arise as factors of area
preserving maps of the unit square via a geometric Baker's map type
construction, exhibit intermittent dynamics, and have unbounded derivatives.
The geometric approach captures various examples from the literature over the
last thirty years. The statistics of these maps are controlled by the order of
tangency that a certain "cut function" makes with the boundary of the square.
Using a large deviations result of Melbourne and Nicol we obtain sharp
estimates on the distribution of first hyperbolic times. As shown by Alves,
Viana and others, knowledge of the tail of the distribution of first hyperbolic
times leads to estimates on the rate of decay of correlations and derivation of
a CLT. For our family of maps, we compare the estimates on correlation decay
rate and CLT derived via hyperbolic times with those derived by a direct Young
tower construction. The latter estimates are known to be sharp.


title:
De Branges-Rovnyak realizations of operator-valued Schur functions on
  the complex right half-plane

abstract:
  We give a controllable energy-preserving and an observable
co-energy-preserving de Branges-Rovnyak functional model realization of an
arbitrary given operator Schur function defined on the complex right-half
plane. We work the theory out fully in the right-half plane, without using
results for the disk case, in order to expose the technical details of
continuous-time systems theory. At the end of the article, we make explicit the
connection to the corresponding classical de Branges-Rovnyak realizations for
Schur functions on the complex unit disk.


title: New Mira Variables from the MACHO Galactic Bulge Fields, part II

abstract:
  We present a new sample of 525 Mira variables in the direction of the
Galactic Bulge, expanding on previous samples of 69 and 500 objects,
respectively, and thereby concluding our search for new Mira variables in the
MACHO Galactic Bulge fields. 364 Miras of the present sample are reported as
variable stars for the first time. We have cross-correlated our sample with the
sample of Mira stars from the OGLE-III Catalog of Long-Period Variables (LPVs)
in the Galactic Bulge and found 146 matches; MACHO and OGLE periods are in very
good overall agreement. We present summary data for all stars of the present
sample and give a statistical overview, comparing the properties of the MACHO
and OGLE samples and enlarging on the analyses in our previous paper.
Lightcurves, folded lightcurves and further details are available via the AAVSO
International Variable Star Index (http://www.aavso.org/vsx/). Data of the
complete sample of Mira variables from the MACHO Galactic Bulge fields, as
presented in our papers (Bernhard, 2011; Huemmerich and Bernhard, 2012 and the
present paper), can be found in the appendix.


title:
Tridiagonal pairs of $q$-Racah type, the double lowering operator
  $\psi$, and the quantum algebra $U_q(\mathfrak{sl}_2)$

abstract:
  Let \K denote an algebraically closed field and let V denote a vector space
over \K with finite positive dimension. We consider an ordered pair of linear
transformations A:V\to V,A*:V \to V that satisfy the following
conditions:(i)Each of A,A* is diagonalizable;(ii)there exists an ordering
{V_i}_{i=0}^d of the eigenspaces of A such that A*V_i\subseteq
V_{i-1}+V_i+V_{i+1} for 0\leq i\leq d, where V_{-1}=0 and V_{d+1}=0;(iii)there
exists an ordering {V*_i}_{i=0}^\delta of the eigenspaces of A* such that A
V*_i\subseteq V*_{i-1}+V*_i+V*_{i+1} for 0\leq i\leq\delta, where V*_{-1}=0 and
V*_{\delta+1}=0;(iv)there does not exist a subspace W of V such that
AW\subseteq W,A*W\subseteq W,W\neq 0,W\neq V. We call such a pair a tridiagonal
pair on V. It is known that d=\delta; to avoid trivialities assume d\geq 1. We
assume that A,A* belongs to a family of tridiagonal pairs said to have q-Racah
type. This is the most general type of tridiagonal pair. Let {U_i}_{i=0}^d and
{U_i^\Downarrow}_{i=0}^d denote the first and second split decompositions of V.
In an earlier paper we introduced the double lowering operator \psi:V\to V. One
feature of \psi is that both \psi U_i\subseteq U_{i-1} and \psi
U_i^\Downarrow\subseteq U_{i-1}^\Downarrow for 0\leq i\leq d. Define linear
transformations K:V\to V and B:V\to V such that (K-q^{d-2i}I)U_i=0 and
(B-q^{d-2i}I)U_i^\Downarrow=0 for 0\leq i\leq d. Our results are summarized as
follows. Using \psi,K,B we obtain two actions of Uq(sl2) on V. For each of
these Uq(sl2)-module structures, the Chevalley generator e acts as a scalar
multiple of \psi. For each of the Uq(sl2)-module structures, we compute the
action of the Casimir element on V. We show that these two actions agree. Using
this fact, we express \psi as a rational function of K^{\pm 1},B^{\pm 1} in
several ways. Eliminating \psi from these equations we find that K,B are
related by a quadratic equation.


title:
Towards an Efficient Discovery of the Topological Representative
  Subgraphs

abstract:
  With the emergence of graph databases, the task of frequent subgraph
discovery has been extensively addressed. Although the proposed approaches in
the literature have made this task feasible, the number of discovered frequent
subgraphs is still very high to be efficiently used in any further exploration.
Feature selection for graph data is a way to reduce the high number of frequent
subgraphs based on exact or approximate structural similarity. However, current
structural similarity strategies are not efficient enough in many real-world
applications, besides, the combinatorial nature of graphs makes it
computationally very costly. In order to select a smaller yet structurally
irredundant set of subgraphs, we propose a novel approach that mines the top-k
topological representative subgraphs among the frequent ones. Our approach
allows detecting hidden structural similarities that existing approaches are
unable to detect such as the density or the diameter of the subgraph. In
addition, it can be easily extended using any user defined structural or
topological attributes depending on the sought properties. Empirical studies on
real and synthetic graph datasets show that our approach is fast and scalable.


title: On continuing codes

abstract:
  We investigate what happens when we try to work with continuing block codes
(i.e. left or right continuing factor maps) between shift spaces that may not
be shifts of finite type. For example, we demonstrate that continuing block
codes on strictly sofic shifts do not behave as well as those on shifts of
finite type; a continuing block code on a sofic shift need not have a uniformly
bounded retract, unlike one on a shift of finite type. A right eresolving code
on a sofic shift can display any behavior arbitrary block codes can have. We
also show that a right continuing factor of a shift of finite type is always a
shift of finite type.


title: Real Time Electrical Detection of Coherent Spin Oscillations

abstract:
  We demonstrate that the bandwidth of pulsed electrically detected magnetic
resonance can be increased to at least 80 MHz using a radio
frequency-reflectometry detection scheme. Using this technique, we measure
coherent spin oscillations in real time during a resonant microwave pulse. We
find that the observed signal is in quantitative agreement with simulations
based on rate equations modeling the recombination dynamics of the spin system
under study. The increased bandwidth opens the way to electrically study faster
spin-dependent recombination processes, e.g., in direct semiconductors which so
far have almost exclusively been studied by optically detected magnetic
resonance.


title:
Covering Ideals of Morphisms and Module Representations of the quiver
  $\mathbb{A}_2$

abstract:
  Sufficient conditions for an ideal $\mathcal I$ in $R\Mod$ to be covering are
proved. This allows to obtain an alternative proof of the existence of phantom
covers of modules. Our approach is inspired by an extension of the standard
deconstructibility techniques used in Approximation Theory.


title: Optimal architecture for a non-deterministic noiseless linear amplifier

abstract:
  Non-deterministic quantum noiseless linear amplifiers are a new technology
with interest in both fundamental understanding and new applications. With a
noiseless linear amplifier it is possible to perform tasks such as improving
the performance of quantum key distribution and purifying lossy channels.
Previous designs for noiseless linear amplifiers involving linear optics and
photon counting are non-optimal because they have a probability of success
lower than the theoretical bound given by the theory of generalised quantum
measurement. This paper develops a theoretical model which reaches this limit.
We calculate the fidelity and probability of success of this new model for
coherent states and Einstein-Podolsky-Rosen (EPR) entangled states.


title: DiFS: Distributed Flow Scheduling for Data Center Networks

abstract:
  Data center networks leverage multiple parallel paths connecting end host
pairs to offer high bisection bandwidth for cluster computing applications.
However, state of the art distributed multi-pathing protocols such as Equal
Cost Multipath (ECMP) use static flow-to-link assignment, which is
load-oblivious. They may cause bandwidth loss due to \emph{flow collisions} on
a same link. Recently proposed centralized scheduling algorithm or host-based
multi-pathing may suffer from scalability problems.
  In this paper, we present Distributed Flow Scheduling (DiFS) for data center
networks, which is a switch-only distributed solution. DiFS allows switches
cooperate to avoid over-utilized links and find available paths without
centralized control. DiFS is scalable and can react quickly to dynamic traffic,
because it is independently executed on switches and requires no
synchronization. Extensive experiments show that the aggregate bisection
bandwidth of DiFS using various traffic patterns is much better than that of
ECMP, and is similar to or higher than that of a recent proposed centralized
scheduling algorithm.


title:
Equational characterization for two-valued states in orthomodular
  quantum systems

abstract:
  In this paper we develop an algebraic framework in which several classes of
two-valued states over orthomodular lattices may be equationally characterized.
The class of two-valued states and the subclass of Jauch-Piron two-valued
states are among the classes which we study.


title: BEC-BCS Crossover and the EoS of Strongly Interacting Systems

abstract:
  We show that at sufficiently strong coupling, quarks form a BEC system that
does not collapse into a pressureless gas at zero temperature only if the
diquark-diquark repulsion is self-consistently taken into account. It is found
that there is a critical value of the coupling constant of the diquark-diquark
interaction beyond which the tendency at zero temperature of the strongly
interacting diquark gas to condense into the system ground state with zero
momentum is compensated by the repulsion between diquarks so keeping a positive
pressure with no significant variation along the whole strongly interacting
region. We discuss possible implications of the diquark-diquark interaction for
the astrophysics of compact stars. Also we analyze the effect of a strong
magnetic field for the BEC-BCS crossover.