title:
Nanoscale multifunctional sensor formed by a Ni nanotube and a scanning
  Nb nanoSQUID

abstract:
  Nanoscale magnets might form the building blocks of next generation memories.
To explore their functionality, magnetic sensing at the nanoscale is key. We
present a multifunctional combination of a scanning nanometer-sized
superconducting quantum interference device (nanoSQUID) and a Ni nanotube
attached to an ultrasoft cantilever as a magnetic tip. We map out and analyze
the magnetic coupling between the Ni tube and the Nb nanoSQUID, demonstrate
imaging of an Abrikosov vortex trapped in the SQUID structure - which is
important in ruling out spurious magnetic signals - and reveal the high
potential of the nanoSQUID as an ultrasensitive displacement detector. Our
results open a new avenue for fundamental studies of nanoscale magnetism and
superconductivity.


title: Optical readout: a tool for studying gas-avalanche processes

abstract:
  Optical recording of avalanche-induced photons is an interesting tool for
studying basic physics processes in gaseous detectors. In this work we
demonstrate the potential of optical readout in avalanche-propagation
investigations in Thick Gas Electron Multipliers (THGEMs) operated with Ne/CF4
(95/5). We present the results of direct measurements, with single- and
cascaded-THGEM detectors irradiated with soft x-rays, of the hole-multiplicity
and avalanche asymmetry within holes, as a function of detector parameters.
Further study directions are discussed.


title: Coherent Destruction of Tunneling and Dark Floquet State

abstract:
  We study a system of three coherently coupled states, where one state is
shifted periodically against the other two. We discover such a system possesses
a dark Floquet state at zero quasienergy and always with negligible population
at the intermediate state. This dark Floquet state manifests itself dynamically
in terms of the suppression of inter-state tunneling, a phenomenon known as
coherent destruction of tunneling. We suggest to call it dark coherent
destruction of tunneling (DCDT). At high frequency limit for the periodic
driving, this Floquet state reduces to the well-known dark state widely used
for STIRAP. Our results can be generalized to systems with more states and can
be verified with easily implemented experiments within current technologies.


title: Quantum Monte Carlo study of the two-dimensional ferromagnet

abstract:
  We present Quantum Monte Carlo calculations that probe the
paramagnet-ferromagnet phase transition in a two-dimensional Stoner
Hamiltonian. With a screened Coulomb interaction we observe a first order
ferromagnetic transition for short screening lengths, and a second order
transition with a longer screening length, accompanied by a rising critical
interaction strength. Finally, we discuss the consequences of our results for
an ultracold atomic gas with finite ranged interactions.


title: How to find real-world applications for compressive sensing

abstract:
  The potential of compressive sensing (CS) has spurred great interest in the
research community and is a fast growing area of research. However, research
translating CS theory into practical hardware and demonstrating clear and
significant benefits with this hardware over current, conventional imaging
techniques has been limited. This article helps researchers to find those niche
applications where the CS approach provides substantial gain over conventional
approaches by articulating lessons learned in finding one such application; sea
skimming missile detection. As a proof of concept, it is demonstrated that a
simplified CS missile detection architecture and algorithm provides comparable
results to the conventional imaging approach but using a smaller FPA. The
primary message is that all of the excitement surrounding CS is necessary and
appropriate for encouraging our creativity but we all must also take off our
"rose colored glasses" and critically judge our ideas, methods and results
relative to conventional imaging approaches.


title: On a Problem in Diophantine Approximation

abstract:
  We prove new results, related to the Littlewood and Mixed Littlewood
conjectures in Diophantine approximation.


title: Effects of stoichiometric doping in superconducting Bi-O-S compounds

abstract:
  Newly discovered Bi-O-S compounds remain an enigma in attempts to understand
their electronic properties. A recent study of Bi$_{4}$O$_{4}$S$_{3}$ has shown
it to be a mixture of two phases, Bi$_{2}$OS$_{2}$ and Bi$_{3}$O$_{2}$S$_{3}$,
the latter being superconducting [W. A. Phelan et al., J. Am. Chem. Soc. 135,
5372 (2013)]. Using density functional theory, we explore the electronic
structure of both the phases and the effect of the introduction of stacking
faults. Our results demonstrate that the S$_{2}$ layers dope the
bismuth-sulphur bands. The bands at the Fermi level are of clear
two-dimensional character. One band manifold is confined to the two adjacent,
square-lattice bismuth-sulphur planes, a second manifold is confined to the
square lattice of sulphur dimers. We show that the introduction of defects in
the stacking does not influence the electronic structure. Finally, we also show
that spin-orbit coupling does not have any significant effect on the states
close to the Fermi level at the energy scale considered.


title:
Trees under attack: a Ray-Knight representation of Feller's branching
  diffusion with logistic growth

abstract:
  We obtain a representation of Feller's branching diffusion with logistic
growth in terms of the local times of a reflected Brownian motion $H$ with a
drift that is affine linear in the local time accumulated by $H$ at its current
level. As in the classical Ray-Knight representation, the excursions of $H$ are
the exploration paths of the trees of descendants of the ancestors at time
$t=0$, and the local time of $H$ at height $t$ measures the population size at
time $t$ (see e.g. \cite{LG4}). We cope with the dependence in the reproduction
by introducing a pecking order of individuals: an individual explored at time
$s$ and living at time $t=H_s$ is prone to be killed by any of its
contemporaneans that have been explored so far. The proof of our main result
relies on approximating $H$ with a sequence of Harris paths $H^N$ which figure
in a Ray-Knight representation of the total mass of a branching particle
system. We obtain a suitable joint convergence of $H^N$ together with its local
times {\em and} with the Girsanov densities that introduce the dependence in
the reproduction.


title:
The first passage time problem over a moving boundary for asymptotically
  stable L\'evy processes

abstract:
  We study the asymptotic tail behaviour of the first-passage time over a
moving boundary for asymptotically $\alpha$-stable L\'evy processes with
$\alpha<1$.
  Our main result states that if the left tail of the L\'evy measure is
regularly varying with index $- \alpha$ and the moving boundary is equal to $1
- t^{\gamma}$ for some $\gamma<1/\alpha$, then the probability that the process
stays below the moving boundary has the same asymptotic polynomial order as in
the case of a constant boundary. The same is true for the increasing boundary
$1 + t^{\gamma}$ with $\gamma<1/\alpha$ under the assumption of a regularly
varying right tail with index $- \alpha$.


title: The interplanetary magnetic field: radial and latitudinal dependences

abstract:
  Results of the analysis of spacecraft measurements at 1-5.4 AU are presented
within the scope of the large-scale interplanetary magnetic field (IMF)
structure investigation. The work is focused on revealing of the radial IMF
component (Br) variations with heliocentric distance and latitude as seen by
Ulysses. It was found out that |Br| decreases as ~r^-5/3 in the ecliptic plane
vicinity (10 deg. of latitude). This is consistent with the previous results
obtained on the basis of five spacecraft in-ecliptic measurements (Khabarova,
Obridko, 2012). The difference between the experimentally found (r^-5/3) and
commonly used (r^-2) radial dependence of Br may lead to mistakes in the IMF
recalculations from point to point in the heliosphere. This can be one of the
main sources of the 'magnetic flux excess' effect, which is exceeding of the
distantly measured magnetic flux over the values obtained through the
measurements at the Earth orbit. It is shown that the radial IMF component can
be considered as independent of heliolatitude in a rough approximation only.
More detailed analysis demonstrates an expressed |Br| (as well as the IMF
strength) increase in the latitudinal vicinity of 30 deg. relative to the
ecliptic plane. Also, a slight increase of the both parameters is observed in
the polar solar wind. The analysis of the latitudinal and radial dependences of
the Br distribution's bimodality is performed. The investigation has not
revealed any dependence between Br and the solar wind speed V. Meanwhile, the
two-peak distribution of the solar wind speed as measured by Ulysses is a
consequence of a strong latitudinal and solar cycle dependence of V. It is
shown that the solar wind speed in high latitudes (above 40 deg.)
anti-correlates with a solar activity: V is maximal during the solar cycle
minima, and it has a minimum at the maximum of solar activity.


title:
PDRF: A General Dispersion Relation Solver for Magnetized Multi-Fluid
  Plasma

abstract:
  A general dispersion-relation solver that numerically evaluates the full
propagation properties of all the waves in fluid plasmas is presented. The
effects of anisotropic pressure, external magnetic fields and beams,
relativistic dynamics, as well as local plasma inhomogeneity are included.
[Computer Physics Communications, (2013); doi: 10.1016/j.cpc.2013.10.012; code:
http://cpc.cs.qub.ac.uk/summaries/AERF\_v1\_0.html]

categories: physics.plasm-ph astro-ph.SR physics.comp-ph physics.space-ph


title: A Contrario Selection of Optimal Partitions for Image Segmentation

abstract:
  We present a novel segmentation algorithm based on a hierarchical
representation of images. The main contribution of this work is to explore the
capabilities of the A Contrario reasoning when applied to the segmentation
problem, and to overcome the limitations of current algorithms within that
framework. This exploratory approach has three main goals.
  Our first goal is to extend the search space of greedy merging algorithms to
the set of all partitions spanned by a certain hierarchy, and to cast the
segmentation as a selection problem within this space. In this way we increase
the number of tested partitions and thus we potentially improve the
segmentation results. In addition, this space is considerably smaller than the
space of all possible partitions, thus we still keep the complexity controlled.
  Our second goal aims to improve the locality of region merging algorithms,
which usually merge pairs of neighboring regions. In this work, we overcome
this limitation by introducing a validation procedure for complete partitions,
rather than for pairs of regions.
  The third goal is to perform an exhaustive experimental evaluation
methodology in order to provide reproducible results.
  Finally, we embed the selection process on a statistical A Contrario
framework which allows us to have only one free parameter related to the
desired scale.


title:
From Brownian motion with a local time drift to Feller's branching
  diffusion with logistic growth

abstract:
  We give a new proof for a Ray-Knight representation of Feller's branching
diffusion with logistic growth in terms of the local times of a reflected
Brownian motion $H$ with a drift that is affine linear in the local time
accumulated by $H$ at its current level. In \cite{LPW}, such a representation
was obtained by an approximation through Harris paths that code the genealogies
of particle systems. The present proof is purely in terms of stochastic
analysis, and is inspired by previous work of Norris, Rogers and Williams
\cite{NRW}.


title: Binary trees, exploration processes, and an extented Ray--Knight Theorem

abstract:
  We study the bijection between binary Galton--Watson trees in continuous time
and their exploration process, both in the sub- and in the supercritical cases.
We then take the limit over renormalized quantities, as the size of the
population tends to infinity. We thus deduce Delmas' generalization of the
second Ray--Knight theorem.


title:
Dynamic Correlators of Fermi-Pasta-Ulam Chains and Nonlinear Fluctuating
  Hydrodynamics

abstract:
  We study the equilibrium time correlations for the conserved fields of
classical anharmonic chains and argue that their dynamic correlator can be
predicted on the basis of nonlinear fluctuating hydrodynamics. In fact our
scheme is more general and would cover also other one-dimensional hamiltonian
systems, for example classical and quantum fluids. Fluctuating hydrodynamics is
a nonlinear system of conservation laws with noise. For a single mode it is
equivalent to the noisy Burgers equation, for which explicit solutions are
available. Our focus is the case of several modes. No exact solutions have been
found so far and we rely on a one-loop approximation. The resulting
mode-coupling equations have a quadratic memory kernel and describe the time
evolving 3 x 3 correlator matrix of the locally conserved fields. Long time
asymptotics is computed analytically and finite time properties are obtained
through a numerical simulation of the mode-coupling equations.


title: Bose-Einstein condensation of photons in an ideal atomic gas

abstract:
  We study peculiarities of Bose-Einstein condensation of photons that are in
thermodynamic equilibrium with atoms of noninteracting gases. General equations
of the thermodynamic equilibrium of the system under study are obtained. We
examine solutions of these equations in the case of high temperatures, when the
atomic components of the system can be considered as nondegenerated ideal gases
of atoms, and the photonic component can form a state with the Bose condensate.
Transcendental equation for transition temperature and expression for the
density of condensed photons in the considered system are derived. We also
obtain analytical solutions of the equation for the critical temperature in a
number of particular cases. The existence of two regimes of Bose condensation
of photons, which differ significantly in nature of transition temperature
dependence on the total density of photons pumped into the system, is revealed.
In one case, this dependence is a traditional fractional-power law, and in
another one it is the logarithmic law. Applying numerical methods, we determine
boundaries of existence and implementation conditions for different regimes of
condensation depending on the physical parameters of the system under study. We
also show that for a large range of physical systems that are in equilibrium
with photons (from ultracold gases of alkali metals to certain types of ideal
plasma), the condensation of photons should occur according to the logarithmic
regime.


title: Homogenization of a periodic semilinear elliptic degenerate PDE

abstract:
  In this paper a semilinear elliptic PDE with rapidly oscillating coefficients
is homogenized. The novetly of our result lies in the fact that we allow the
second order part of the differential operator to be degenerate in some portion
of $\R^d$.\\ Our fully probabilistic method is based on the connection between
PDEs and BSDEs with random terminal time and the weak convergence of a class of
diffusion processes.


title: Statistical Analysis of Metric Graph Reconstruction

abstract:
  A metric graph is a 1-dimensional stratified metric space consisting of
vertices and edges or loops glued together. Metric graphs can be naturally used
to represent and model data that take the form of noisy filamentary structures,
such as street maps, neurons, networks of rivers and galaxies. We consider the
statistical problem of reconstructing the topology of a metric graph embedded
in R^D from a random sample. We derive lower and upper bounds on the minimax
risk for the noiseless case and tubular noise case. The upper bound is based on
the reconstruction algorithm given in Aanjaneya et al. (2012).


title: Systematic study of (p,\gamma) reactions on Ni isotopes

abstract:
  A systematic study of the radiative proton capture reaction for all stable
nickel isotopes is presented. The results were obtained using 2.0 - 6.0 MeV
protons from the 11 MV tandem Van de Graaff accelerator at the University of
Notre Dame. The \gamma-rays were detected by the NSCL SuN detector utilising
the \gamma-summing technique. The results are compared to a compilation of
earlier measurements and discrepancies between the previous data are resolved.
The experimental results are also compared to the theoretical predictions
obtained using the NON-SMOKER and SMARAGD codes. Based on these comparisons an
improved set of astrophysical reaction rates is proposed for the (p,\gamma)
reactions on the stable nickel isotopes as well as for the 56Ni(p,\gamma)57Cu
reaction.


title:
Astrophysical evidence for an extra dimension: phenomenology of a Kaluza
  Klein theory

abstract:
  In this brief review we discuss the viability of a multidimensional
geometrical theory with one compactified dimension. We discuss the case of a
Kaluza Klein fifth dimensional theory, addressing the problem by an overview of
the astrophysical phenomenology associated with this five dimensional theory.
By comparing the predictions of our model with the features of the ordinary
(four dimensional) Relativistic Astrophysics, we highlight some small but
finite discrepancies, expectably detectible from the observations. We consider
a class of static, vacuum solutions of free electromagnetic Kaluza Klein
equations with three dimensional spherical symmetry. We explore the stability
of the particle dynamics in these spacetimes, the construction of self
gravitating stellar models and the emission spectrum generated by a charged
particle falling on this stellar object. The matter dynamics in these
geometries has been treated by a multipole approach adapted to the geometric
theory with a compactified dimension.


title: How fast do polynomials grow on semialgebraic sets?

abstract:
  We study the growth of polynomials on semialgebraic sets. For this purpose we
associate a graded algebra to the set, and address all kinds of questions about
finite generation. We show that for a certain class of sets, the algebra is
finitely generated. This implies that the total degree of a polynomial
determines its growth on the set, at least modulo bounded polynomials. We
however also provide several counterexamples, where there is no connection
between total degree and growth. In the plane, we give a complete answer to our
questions for certain simple sets, and we provide a systematic construction for
examples and counterexamples. Some of our counterexamples are of particular
interest for the study of moment problems, since none of the existing methods
seems to be able to decide the problem there. We finally also provide new
three-dimensional sets, for which the algebra of bounded polynomials is not
finitely generated.


title:
An insight into the importance of national university rankings in an
  international context: The case of the I-UGR Rankings of Spanish universities

abstract:
  The great importance international rankings have achieved in the research
policy arena warns against many threats consequence of the flaws and
shortcomings these tools present. One of them has to do with the inability to
accurately represent national university systems as their original purpose is
only to rank world-class universities. Another one has to do with the lack of
representativeness of universities' disciplinary profiles as they usually
provide a unique table. Although some rankings offer a great coverage and
others offer league tables by fields, no international ranking does both. In
order to surpass such limitation from a research policy viewpoint, this paper
analyzes the possibility of using national rankings in order to complement
international rankings. For this, we analyze the Spanish university system as a
study case presenting the I-UGR Rankings for Spanish universities by fields and
subfields. Then, we compare their results with those obtained by the Shanghai
Ranking, the QS Ranking, the Leiden Ranking and the NTU Ranking, as they all
have basic common grounds which allow such comparison. We conclude that it is
advisable to use national rankings in order to complement international
rankings, however we observe that this must be done with certain caution as
they differ on the methodology employed as well as on the construction of the
fields.


title:
On the equal time two-point distribution of the one-dimensional KPZ
  equation by replica

abstract:
  In a recent contribution, Dotsenko establishes a Fredholm determinant formula
for the two-point distribution of the KPZ equation in the long time limit and
starting from narrow wedge initial conditions. We establish that his expression
is identical to the Fredholm determinant resulting from the Airy$_2$ process.


title:
Guided Neuronal Growth on Arrays of Biofunctionalized GaAs/InGaAs
  Semiconductor Microtubes

abstract:
  We demonstrate embedded growth of cortical mouse neurons in dense arrays of
semiconductor microtubes. The microtubes, fabricated from a strained
GaAs/InGaAs heterostructure, guide axon growth through them and enable
electrical and optical probing of propagating action potentials. The coaxial
nature of the microtubes -- similar to myelin -- is expected to enhance the
signal transduction along the axon. We present a technique of suppressing
arsenic toxicity and prove the success of this technique by overgrowing
neuronal mouse cells.


title: Unique decomposition for a polynomial of low rank

abstract:
  Let $F$ be a homogeneous polynomial of degree $d$ in $m+1$ variables defined
over an algebraically closed field of characteristic 0 and suppose that $F$
belongs to the $s$-th secant variety of the $d$-uple Veronese embedding of
$\mathbb{P}^m$ into $ \PP {{m+d\choose d}-1}$ but that its minimal
decomposition as a sum of $d$-th powers of linear forms requires more than $s$
addenda. We show that if $s\leq d$ then $F$ can be uniquely written as
$F=M_1^d+\cdots + M_t^d+Q$, where $M_1, \ldots, M_t$ are linear forms with
$t\leq (d-1)/2$, and $Q$ a binary form such that $Q=\sum_{i=1}^q
l_i^{d-d_i}m_i$ with $l_i$'s linear forms and $m_i$'s forms of degree $d_i$
such that $\sum (d_i+1)=s-t$.


title: What Should be the Role of Field Energy in Introductory Physics Courses?

abstract:
  A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and
Core Ideas gives the concept of field energy a prominent role in the physical
sciences sections of its recommendations for K-12 science education. I examine
what A Framework suggests for the role of field energy and point out that,
given the ambiguities and complexities associated with field energy, a
traditional approach focusing on potential (configuration) energy is more
appropriate for introductory physics in secondary schools, colleges, and
universities.


title: Construction of two SD Codes

abstract:
  SD codes are erasure codes that address the mixed failure mode of current
RAID systems. Rather than dedicate entire disks to erasure coding, as done in
RAID-5, RAID-6 and Reed-Solomon coding, an SD code dedicates entire disks, plus
individual sectors to erasure coding. The code then tolerates combinations of
disk and sector errors, rather than solely disk errors. It is been an open
problem to construct general codes that have the SD property, and previous work
has relied on Monte Carlo searches. In this paper, we present two general
constructions that address the cases with one disk and two sectors, and two
disks and two sectors. Additionally, we make an observation about shortening SD
codes that allows us to prune Monte Carlo searches.


title: A Note on (Parallel) Depth- and Breadth-First Search by Arc Elimination

abstract:
  This note recapitulates an algorithmic observation for ordered Depth-First
Search (DFS) in directed graphs that immediately leads to a parallel algorithm
with linear speed-up for a range of processors for non-sparse graphs. The note
extends the approach to ordered Breadth-First Search (BFS). With $p$
processors, both DFS and BFS algorithms run in $O(m/p+n)$ time steps on a
shared-memory parallel machine allowing concurrent reading of locations, e.g.,
a CREW PRAM, and have linear speed-up for $p\leq m/n$. Both algorithms need $n$
synchronization steps.


title:
B physics and Extended Higgs sectors (Tauonic B decays and two Higgs
  doublet models)

abstract:
  Recent experimental results on exclusive semi-tauonic B meson decays show
sizable deviations from the standard model prediction, while the recent result
on pure-tauonic decay reduces the deviation from the prediction. These results
suggest an indirect evidence of new physics in which the structure of the
relevant weak charged interaction may differ from that of the standard model.
We study these tauonic B decays in the context of extensions of the Higgs
sector. As a result, we find that two Higgs doublet models without tree-level
FCNC are unlikely to explain the present experimental data while those allowing
FCNC are consistent with the data.


title: Stimulation of static deconfined medium by multiple hard partons

abstract:
  We investigate the response of non-expanding deconfined hot matter to energy
and momentum deposition from a pair of partons moving with high energies.
Several situations are examined with partons moving so that the generated wakes
in the medium interact. The resulting energy and flow profiles are studied.
Such cases are relevant for nuclear collisions at the LHC where several hard
partons are produced in a single collision and their contribution to collective
expansion of the fireball may be important.


title:
How substance-based ontologies for gravity can be productive: A case
  study

abstract:
  Many science education researchers have argued that learners' commitment to a
substance (matter-based) ontology impedes the learning of scientific concepts
that scientists typically conceptualize as processes or interactions, such as
such as force, electric current, and heat. By this account, students' tendency
to classify these entities as substances or properties of substances leads to
robust misconceptions, and instruction should steer novices away from
substance-based reasoning. We argue that substance-based reasoning, when it
supports learners' sense-making, can form the seeds for sophisticated
understanding of these very same physics concepts. We present a case study of a
group of elementary school science teachers in our professional development
program. The teachers build a sophisticated explanation for why objects of
different masses have the same acceleration due to gravity, starting from
substance-based metaphors for gravity. We argue that, for conceptual,
epistemological, and affective reasons, instructional interventions should
focus on tapping these productive matter-based resources rather than attempting
to replace them.


title:
Ground state of three qubits coupled to a harmonic oscillator with
  ultrastrong coupling

abstract:
  We study the Rabi model composed of three qubits coupled to a harmonic
oscillator without involving the rotating-wave approximation. We show that the
ground state of the three-qubit Rabi model can be analytically treated by using
the transformation method, and the transformed ground state agrees well with
the exactly numerical simulation under a wide range of qubit-oscillator
coupling strengths for different detunings. We use the pairwise entanglement to
characterize the ground-state entanglement between any two qubits and show that
it has an approximately quadratic dependence on the qubit-oscillator coupling
strength. Interestingly, we find that there is no qubit-qubit entanglement for
the ground state if the qubit-oscillator coupling strength is large enough.


title: Bredon cohomological dimensions for proper actions and Mackey functors

abstract:
  For groups with a uniform bound on the length of chains of finite subgroups,
we study the relationship between the Bredon cohomological dimension for proper
actions and the notions of cohomological dimension one obtains by restricting
the coefficients of Bredon cohomology to (cohomological) Mackey functors or
fixed point functors. We also investigate the closure properties of the class
of groups with finite Bredon cohomological dimension for Mackey functors.


title: Periodic lattice with defects

abstract:
  The discrete periodic lattice of masses and springs with line and point
defects is considered. The dispersion equations for propagative, guided and
localised waves are obtained. The detailed analysis of example with three
masses is provided.


title:
Central limit theorems for pre-averaging covariance estimators under
  endogenous sampling times

abstract:
  We consider two continuous It\^o semimartingales observed with noise and
sampled at stopping times in a nonsynchronous manner. In this article we
establish a central limit theorem for the pre-averaged Hayashi-Yoshida
estimator of their integrated covariance in a general endogenous time setting.
In particular, we show that the time endogeneity has no impact on the
asymptotic distribution of the pre-averaged Hayashi-Yoshida estimator, which
contrasts the case for the realized volatility in a pure diffusion setting. We
also establish a central limit theorem for the modulated realized covariance,
which is another pre-averaging based integrated covariance estimator, and
demonstrate the above property seems to be a special feature of the
pre-averaging technique.


title: Rate Distortion Function for a Class of Relative Entropy Sources

abstract:
  This paper deals with rate distortion or source coding with fidelity
criterion, in measure spaces, for a class of source distributions. The class of
source distributions is described by a relative entropy constraint set between
the true and a nominal distribution. The rate distortion problem for the class
is thus formulated and solved using minimax strategies, which result in robust
source coding with fidelity criterion. It is shown that minimax and maxmin
strategies can be computed explicitly, and they are generalizations of the
classical solution. Finally, for discrete memoryless uncertain sources, the
rate distortion theorem is stated for the class omitting the derivations while
the converse is derived.


title: Optimality of Moore neighborhoods in protein contact maps

abstract:
  A protein contact map is a binary symmetric adjacency matrix capturing the
distance relationship between atoms of a protein. Each cell (i, j) of a protein
contact map states whether the atoms (nodes) i and j are within some Euclidean
distance from each other. We examined the radius one Moore neighborhood
surrounding each cell (i, j) where j > (i + 2) in complete protein contact maps
by mutating them one at a time. We found that the particular configuration of a
neighborhood is generally (97%) optimal in the sense that no other
configuration could maintain or improve upon existing local and global
efficiencies of the nodes residing in a neighborhood. Local efficiency of a
node is directly related to its clustering measure. Global efficiency of a node
is inversely related to its distance to other nodes in the network. This
feature of the Moore neighborhood in complete protein contact maps may explain
how protein residue networks are able to form long-range links to reduce
average path length while maintaining a high level of clustering throughout the
process of small-world formation, and could suggest new approaches to protein
contact map prediction. Effectively, the problem of protein contact map
prediction is transformed to one of maximizing the number of optimal
neighborhoods. By comparison, Moore neighborhoods in protein contact maps with
randomized long-range links are less optimal.


title:
Bayesian Modeling and MCMC Computation in Linear Logistic Regression for
  Presence-only Data

abstract:
  Presence-only data are referred to situations in which, given a censoring
mechanism, a binary response can be observed only with respect to on outcome,
usually called \textit{presence}. In this work we present a Bayesian approach
to the problem of presence-only data based on a two levels scheme. A
probability law and a case-control design are combined to handle the double
source of uncertainty: one due to the censoring and one due to the sampling. We
propose a new formalization for the logistic model with presence-only data that
allows further insight into inferential issues related to the model. We
concentrate on the case of the linear logistic regression and, in order to make
inference on the parameters of interest, we present a Markov Chain Monte Carlo
algorithm with data augmentation that does not require the a priori knowledge
of the population prevalence. A simulation study concerning 24,000 simulated
datasets related to different scenarios is presented comparing our proposal to
optimal benchmarks.


title: Reflection couplings and contraction rates for diffusions

abstract:
  We consider contractivity for diffusion semigroups w.r.t. Kantorovich ($L^1$
Wasserstein) distances based on appropriately chosen concave functions. These
distances are inbetween total variation and usual Wasserstein distances. It is
shown that by appropriate explicit choices of the underlying distance,
contractivity with rates of close to optimal order can be obtained in several
fundamental classes of examples where contractivity w.r.t. standard Wasserstein
distances fails. Applications include overdamped Langevin diffusions with
locally non-convex potentials, products of these processes, and systems of
weakly interacting diffusions, both of mean-field and nearest neighbour type.


title: Semileptonic $B_s$ decays at Belle, Babar, and D0

abstract:
  Studies of semileptonic $B_s$ decays by the Belle, Babar and D0 experiments
are reported. In particular measurements of inclusive semileptonic $B_s$ decays
by Belle and Babar and the exclusive excited charm mode $B_s \to D_{s1} \mu
\nu$ from D0 are presented. An outlook on further semileptonic $B_s$
measurements with $\Upsilon(5S)$ data at Belle and Belle II is also given.


title: Tree-level metastability bounds in two-Higgs doublet models

abstract:
  The two Higgs doublet model has a rich vacuum structure, including the
possibility of existence of two Standard Model-like minima at tree-level. It is
therefore possible that the universe's vacuum is metastable, and a deeper
minimum exists. We present the analytical conditions one must demand of the
potential's parameters to prevent that possibility, and analyse what the
current LHC data tells us about the eventual existence of that second minimum.


title: Simulating quantum magnets with symmetric top molecules

abstract:
  We establish a correspondence between the electric dipole matrix elements of
a polyatomic symmetric top molecule in a state with nonzero projection of the
total angular momentum on the symmetry axis of the molecule and the magnetic
dipole matrix elements of a magnetic dipole associated with an elemental spin
$F$. It is shown that this correspondence makes it possible to perform quantum
simulation of the single-particle spectrum and the dipole-dipole interactions
of magnetic dipoles in a static external magnetic field $\bf{B}$ with symmetric
top molecules subject to a static external electric field
$\bf{E}_{\mathrm{DC}}$. We further show that no such correspondence exists for
$^1\Sigma$ molecules in static fields, such as the alkali metal dimers. The
effective spin angular momentum of the simulated magnetic dipole corresponds to
the rotational angular momentum of the symmetric top molecule, and so quantum
simulation of arbitrarily large integer spins is possible. Further, taking the
molecule CH$_3$F as an example, we show that the characteristic dipole-dipole
interaction energies of the simulated magnetic dipole are a factor of 620, 600,
and 310 larger than for the highly magnetic atoms Chromium, Erbium, and
Dysprosium, respectively. We present several applications of our correspondence
for many-body physics, including long-range and anisotropic spin models with
arbitrary integer spin $S$ using symmetric top molecules in optical lattices,
quantum simulation of molecular magnets, and spontaneous demagnetization of
Bose-Einstein condensates due to dipole-dipole interactions. Our results are
expected to be relevant as cold symmetric top molecules reach quantum
degeneracy through Stark deceleration and opto-electrical cooling.


title:
The weak bound state with the non-zero charge density as the LHC 126.5
  GeV state

abstract:
  The self-consistent model of classical field interactions formulated as the
counterpart of the quantum electroweak model leads to homogeneous boson ground
state solutions in presence of non-zero extended fermionic charge density
fluctuations. Two different types of electroweak configurations of fields are
analyzed. The first one has non-zero electric and weak charge fluctuations. The
second one is electrically uncharged but weakly charged. Both types of
configurations have two physically interesting solutions which possess masses
equal to 126.67 GeV at the value of the scalar fluctuation potential parameter
$\lambda$ equal to ~ 0.0652. The spin zero electrically uncharged droplet
formed as a result of the decay of the charged one is interpreted as the ~
126.5 GeV state found in the Large Hadron Collider (LHC) experiment. (The other
two configurations correspond to solutions with masses equal to 123.7 GeV and
$\lambda$ equal to ~ 0.0498 and thus the algebraic mean of the masses of two
central solutions, i.e., 126.67 GeV and 123.7 GeV, is equal to 125.185 GeV.)
The problem of a mass of this kind of droplets will be considered on the basis
of the phenomenon of the screening of the fluctuation of charges. Their masses
are found in the thin wall approximation.


title:
Bernstein modes and giant microwave response of two-dimensional electron
  system

abstract:
  We report on a new contribution to the microwave response of a
two-dimensional electron system in magnetic field which originates from
excitation of virtual Bernstein modes. These collective modes emerge as a
result of interaction between usual magnetoplasmon mode and cyclotron resonance
harmonics. The electrons are found to experience a strongly enhanced radiation
field when its frequency falls in a gap of the Bernstein modes spectrum. This
field can give rise to nonlinear effects, one of which, the parametric
cyclotron resonance, is discussed. We argue that this resonance leads to a
plasma instability in the ultraclean system. The instability-induced heating is
responsible for the giant photoresistivity spike recently observed in the
vicinity of the 2nd cyclotron resonance harmonic.


title:
Universal behavior of the Shannon mutual information of critical quantum
  chains

abstract:
  We consider the Shannon mutual information of subsystems of critical quantum
chains in their ground states. Our results indicate a universal leading
behavior for large subsystem sizes. Moreover, as happens with the entanglement
entropy, its finite-size behavior yields the conformal anomaly $c$ of the
underlying conformal field theory governing the long distance physics of the
quantum chain. We studied analytically a chain of coupled harmonic oscillators
and numerically the Q-state Potts models ($Q = 2$; 3 and 4), the XXZ quantum
chain and the spin-1 Fateev-Zamolodchikov model. The Shannon mutual information
is a quantity easily computed, and our results indicate that for relatively
small lattice sizes its finite-size behavior already detects the universality
class of quantum critical behavior.


title: Minimal entropy approximation for cellular automata

abstract:
  We present a method for construction of approximate orbits of measures under
the action of cellular automata which is complementary to the local structure
theory. The local structure theory is based on the idea of Bayesian extension,
that is, construction of a probability measure consistent with given block
probabilities and maximizing entropy. If instead of maximizing entropy one
minimizes it, one can develop another method for construction of approximate
orbits, at the heart of which is the iteration of finitely-dimensional maps,
called minimal entropy maps. We present numerical evidence that minimal entropy
approximation sometimes spectacularly outperforms the local structure theory in
characterizing properties of cellular automata. Density response curve for
elementary CA rule 26 is used to illustrate this claim.


title: Topological zero modes at nonzero chemical potential

abstract:
  We give analytical and numerical solutions for the zero modes of the Dirac
operator in topological SU(2) gauge backgrounds at nonzero chemical potential.
Continuation from imaginary to real chemical potential is used to
systematically derive analytical zero modes for calorons at arbitrary holonomy
and, in particular limits, for instantons and dyons (magnetic monopoles). For
the latter a spherical ansatz is explored as well. All the zero mode exhibit
stronger peaks at the core and negative regions in their densities. We discuss
the structure of the corresponding overlap matrix elements. For discretized
calorons on the lattice we consider the staggered operator and show that it
does possess (quartet quasi-)zero modes, whose eigenmodes agree very well with
the continuum profiles, also for nonzero chemical potential.


title: The origin of the spectral intensities of cosmic-ray positrons

abstract:
  AMS instrument aboard the International Space Station is a high precision
instrument capable of collecting large statistics on cosmic ray intensities and
as such has started making highly significant contributions to Astroparticle
Physics. In order to fully benefit from these observations, the positron
fraction in cosmic rays in their recent publication and other results that will
follow, the models to interpret the results have to be equally good. We enlarge
on this remark by citing examples from the currently popular model and one of
our own fitting the observed spectra of positrons, extending it to higher
energies. We also show what one might expect to observe from a mono-energetic
source, such as the annihilation of dark matter.


title: On Patterson's Conjecture: Sums of Quartic Exponential Sums

abstract:
  We give more evidence for Patterson's conjecture on sums of exponential sums,
by getting an asymptotic for a sum of quartic exponential sums over $\Q[i].$
Previously, the strongest evidence of Patterson's conjecture over a number
field is the paper of Livn\'{e} and Patterson \cite{LP} on sums of cubic
exponential sums over $\Q[\omega], \omega^3=1.$
  The key ideas in getting such an asymptotic are a Kuznetsov-like trace
formula for metaplectic forms over a quartic cover of $GL_2,$ and an identity
on exponential sums relating Kloosterman sums and quartic exponential sums. To
synthesize the spectral theory and the exponential sum identity, there is need
for a good amount of analytic number theory.
  An unexpected aspect of the asymptotic of the sums of exponential sums is
that there can be a secondary main term additional to the main term which is
not predicted in Patterson's original paper \cite{P}.


title: Evidence of several dipolar quasi-invariants in Liquid Crystals

abstract:
  In a closed quantum system of N coupled spins with magnetic quantum number I,
there are about (2I + 1)^N constants of motion. However, the possibility of
observing such quasi-invariant (QI) states in solid-like spin systems in
Nuclear Magnetic Resonance (NMR) is not a strictly exact prediction. The aim of
this work is to provide experimental evidence of several QI, in the proton NMR
of small spin clusters, besides those already known Zeeman, and dipolar orders
(strong and weak). We explore the spin states prepared with the
Jeener-Broekaert pulse sequence by analyzing the time-domain signals yielded by
this sequence as a function of the preparation times, in a variety of dipolar
networks. We observe that the signals can be explained with two dipolar QIs
only within a range of short preparation times. At longer times the time-domain
signals have an echo-like behaviour. We study their multiple quantum coherence
content on a basis orthogonal to the z-basis and see that such states involve a
significant number of correlated spins. Then we show that the whole preparation
time-scale can only be reconstructed by assuming the occurrence of multiple QI
which we isolate experimentally.


title: Equivariant symplectic homology and multiple closed Reeb orbits

abstract:
  We study the existence of multiple closed Reeb orbits on some contact
manifolds by means of $S^1$-equivariant symplectic homology and the index
iteration formula. It is proved that a certain class of contact manifolds which
admit displaceable exact contact embeddings, a certain class of prequantization
bundles, and Brieskorn spheres have multiple closed Reeb orbits.


title: Anti-selfdual Connections On The Quantum Projective Plane: Instantons

abstract:
  We study one-instantons, that is anti-selfdual connections with instanton
number 1, on the quantum projective plane with orientation which is reversed
with respect to the usual one. The orientation is fixed by a suitable choice of
a basis element for the rank 1 free bimodule of top forms. The noncommutative
family of solutions is foliated, each non-singular leaves being isomorphic to
the quantum projective plane itself.


title: No-Scale Supergravity Realization of the Starobinsky Model of Inflation

abstract:
  We present a model for cosmological inflation based on a no-scale
supergravity sector with an SU(2,1)/U(1) Kahler potential, a single modulus T
and an inflaton superfield Phi described by a Wess-Zumino model with
superpotential parameters (mu, lambda). This model yields a scalar spectral
index n_s and a tensor-to-scalar ratio r that are compatible with the Planck
measurements for values of lambda simeq mu/3M_P. For the specific choice lambda
= mu/3M_P, the model is a no-scale supergravity realization of the R+R^2
Starobinsky model.


title: An entropy-driven cosmic expansion

abstract:
  We examine the evolution of the Friedmann Universe within our recent model of
space-time identified with an elastic continuous medium whose deformations are
described by a vector field constrained to obey a generalized four-dimensional
version of the equilibrium equations of standard elasticity. It is found that
the demand that the entropy associated with such elastic deformations be always
extremal during the expansion of such a Universe turns these equilibrium
equations into a single differential equation governing the evolution of the
Hubble parameter H. The solution to the resulting dynamics admits both a
power-law expansion, analogous to the one induced by an inflaton field, as well
as a power-law expansion analogous to the one induced by a phantom field.
Analyzing both types of expansions via the induced elastic energy and pressure
permits to assign the former to the early Universe and the latter to its
late-time expansion. We discuss the possible way for the dynamics to avoid the
Big Rip singularity that would otherwise result. We succinctly discuss the
possible way to avoid also the Big Bang singularity and how to obtain the large
scale structure of the Universe from the present model.


title: Fractional Standard Map: Riemann-Liouville vs. Caputo

abstract:
  Properties of the phase space of the standard maps with memory obtained from
the differential equations with the Riemann-Liouville and Caputo derivatives
are considered. Properties of the attractors which these fractional dynamical
systems demonstrate are different from properties of the regular and chaotic
attractors of systems without memory: they exist in the asymptotic sense,
different types of trajectories may lead to the same attracting points,
trajectories may intersect, and chaotic attractors may overlap. Two maps have
significant differences in the types of attractors they demonstrate and
convergence of trajectories to the attracting points and trajectories. Still
existence of the the most remarkable new type of attractors, "cascade of
bifurcation type trajectories", is a common feature of both maps.


title:
YNOGK: A new public code for calculating null geodesics in the Kerr
  spacetime

abstract:
  Following \cite{dexagol2009} we present a new public code for the fast
calculation of null geodesics in the Kerr spacetime. Using Weierstrass' and
Jacobi's elliptic functions, we express all coordinates and affine parameters
as analytical and numerical functions of a parameter $p$, which is an integral
value along the geodesic. This is a main difference of our code compares with
previous similar ones. The advantage of this treatment is that the information
about the turning points do not need to be specified in advance by the user,
and many applications such as imaging, the calculation of line profiles or the
observer-emitter problem, etc become root finding problems. All elliptic
integrations are computed by Carlson's elliptic integral method as
\cite{dexagol2009} did, which guarantees the fast computational speed of our
code. The formulae to compute the constants of motion given by
\cite{cunnbard1973} have been extended, which allow one readily to handle the
situations, in which the emitter or the observer has arbitrary distance and
motion state with respect to the central compact object. The validation of the
code has been extensively tested by its application to toy problems from the
literature. The source FORTRAN code is freely available for download on the
web.


title:
Revealing a topological connection between stabilities of Fermi surfaces
  and topological insulators/superconductors

abstract:
  A topology-intrinsic connection between the stabilities of Fermi surfaces
(FSs) and topological insulators/superconductors (TIs/TSCs) is revealed. In
particular, a one-to-one relation between the topological types of FSs and
TIs/TSCs is rigorously derived; combining it with a well-established
topological theory of FSs, we produce a complete table illustrating precisely
topological types of all TIs/TSCs, while a valid part of it was postulated
before. Moreover, we propose and prove a general index theorem that relates the
topological charge of FSs on the natural boundary of a strong TI/TSC to its
bulk topological number. Implications of the general index theorem on the
boundary quasi-particles are also addressed.


title:
Effects of interband transitions on Faraday rotation in metallic
  nanoparticles

abstract:
  The Faraday rotation in metallic nanoparticles is considered based on a
quantum model for the dielectric function \epsilon(\omega) in the presence of a
DC magnetic field B. We focus on effects in \epsilon(\omega) due to interband
transitions (IBTs), which are important in the blue and ultraviolet for noble
metals used in plasmonics. The dielectric function is found using the
perturbation of the electron density matrix due to the optical field of
incident electromagnetic radiation. The calculation is applied to transitions
between two bands (d and p, for example) separated by a gap, as one finds in
gold at the L-point of the Fermi surface. The result of the DC magnetic field
is a shift in the effective optical frequency causing IBTs by $\pm \mu_B B /
\hbar$, where opposite signs are associated with left/right circular
polarizations. Faraday rotation for a dilute solution of 17 nm diameter gold
nanoparticles is measured and compared with both the IBT theory and a simpler
Drude model for the bound electron response. Effects of the plasmon resonance
mode on Faraday rotation in nanoparticles are also discussed.


title:
Brownian motion and the hydrodynamic friction tensor for colloidal
  particles of complex shape

abstract:
  We synthesize colloidal particles with various anisotropic shapes and track
their orientationally resolved Brownian trajectories using confocal microscopy.
An analysis of appropriate short-time correlation functions provides direct
access to the hydrodynamic friction tensor of the particles revealing
nontrivial couplings between the translational and rotational degrees of
freedom. The results are consistent with calculations of the hydrodynamic
friction tensor in the low-Reynolds-number regime for the experimentally
determined particle shapes.


title:
Effects of Planck Scale Physics on Neutrino Mixing Parameters in
  Left-Right Symmetric Models

abstract:
  Left right symmetric models (LRSM) are extensions of the standard model by an
enlarged gauge group $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ where automatic
inclusion of right handed fermions as $SU(2)_R$ doublets guarantees a natural
seesaw origin of neutrino masses. Apart from the extended gauge symmetry, LRSM
also has an in-built global discrete symmetry, called D-parity which ensures
equal gauge couplings for left and right sectors. Motivated by the fact that
global symmetries are expected to be explicitly broken by theories of quantum
gravity, here we study the effects of such gravity or Planck scale physics on
neutrino masses and mixings by introducing explict D-parity breaking Planck
scale suppressed higher dimensional operators. Although such Planck scale
suppressd operators have dimension at least six in generic LRSM, dimension five
operators can also arise in the presence of additional scalar fields which can
be naturally accommodated within SO(10) grand unified theory (GUT) multiplets.
We show that, such corrections can give rise to significant changes in the
predictions for neutrino mixing parameters from the ones predicted by tree
level seesaw formula if the left right symmetry breaking scale is lower than
$10^{14}$ GeV.


title:
How Does the Niagara Whirlpool Get Involved in Niagara River
  Self-Purification?

abstract:
  The Niagara River self-purification through the natural formation of froth at
a site of the Niagara Whirlpool basin has been investigated. It is shown that
the naturally formed froth on the water surface of the Niagara Whirlpool
contains a greater concentration of nutrients, trace metals and phenol in
comparison to subsurface water. The natural pollutants removal process is
explained in detail. As a result, the Niagara River at the Niagara Whirlpool
basin possesses its own natural capacity to self-purify through the natural
formation of froth. We can conclude that the Niagara Whirlpool is a natural
source of Niagara River self-purification. The necessity for the long-term
research on the sites of Niagara River for developing the remediation
strategies is pointed out.


title:
A Convex Functional for Image Denoising based on Patches with
  Constrained Overlaps and its vectorial application to Low Dose Differential
  Phase Tomography

abstract:
  We solve the image denoising problem with a dictionary learning technique by
writing a convex functional of a new form. This functional contains beside the
usual sparsity inducing term and fidelity term, a new term which induces
similarity between overlapping patches in the overlap regions. The functional
depends on two free regularization parameters: a coefficient multiplying the
sparsity-inducing $L_{1}$ norm of the patch basis functions coefficients, and a
coefficient multiplying the $L_{2}$ norm of the differences between patches in
the overlapping regions. The solution is found by applying the iterative
proximal gradient descent method with FISTA acceleration. In the case of
tomography reconstruction we calculate the gradient by applying projection of
the solution and its error backprojection at each iterative step. We study the
quality of the solution, as a function of the regularization parameters and
noise, on synthetic datas for which the solution is a-priori known. We apply
the method on experimental data in the case of Differential Phase Tomography.
For this case we use an original approach which consists in using vectorial
patches, each patch having two components: one per each gradient component. The
resulting algorithm, implemented in the ESRF tomography reconstruction code
PyHST, results to be robust, efficient, and well adapted to strongly reduce the
required dose and the number of projections in medical tomography.


title: On the probability that self-avoiding walk ends at a given point

abstract:
  We prove two results on the delocalization of the endpoint of a uniform
self-avoiding walk on Z^d for d>1. We show that the probability that a walk of
length n ends at a point x tends to 0 as n tends to infinity, uniformly in x.
Also, for any fixed x in Z^d, this probability decreases faster than n^{-1/4 +
epsilon} for any epsilon >0. When |x|= 1, we thus obtain a bound on the
probability that self-avoiding walk is a polygon.


title:
Search for anomalous quartic WW{\gamma}{\gamma} couplings in dielectron
  and missing energy final states in ppbar collisions at sqrt(s) = 1.96 TeV

abstract:
  We present a search for anomalous components of the quartic gauge boson
coupling WW{\gamma}{\gamma} in events with an electron, a positron and missing
transverse energy. The analyzed data correspond to 9.7 fb^-1 of integrated
luminosity collected by the D0 detector in ppbar collisions at sqrt(s) = 1.96
TeV. The presence of anomalous quartic gauge couplings would manifest itself as
an excess of boosted WW events. No such excess is found in the data, and we set
the most stringent limits to date on the anomalous coupling parameters a_0^W
and a_C^W. When a form factor with Lambda_cutoff = 0.5 TeV is used, the
observed upper limits at 95 % C.L. are |a_0^W/Lambda^2|< 0.0025 GeV^-2 and
|a_C^W/Lambda^2| < 0.0092 GeV^-2.


title:
Design and Implementation of a Wireless Sensor and Actuator Network for
  Energy Measurement and Control at Home

abstract:
  This paper describes the design, implementation, and testing of a wireless
sensor and actuator network for monitoring the energy use of electric
appliances in a home environment. The network includes energy measurement nodes
and a central server, where the nodes read the energy use of connected
appliance, and wirelessly report their readings to the central server for
processing. The server displays the readings from these nodes via a user visual
interface in real time. Through this system, users can easily understand their
electricity usage patterns and adapt their behavior to reduce their energy
consumption and costs. Moreover, users are able to remotely power on/off
individual devices to actively control the power use of certain appliances. The
system allows for inexpensive monitoring of home energy use and illustrates a
practical way to control the energy consumption through user interaction.


title: Units in $FD_{2p}$

abstract:
  In this paper, we present the structure of the group of *-unitary units in
the group algebra $FD_{2p}$, where $F$ is a finite field of characteristic $p >
2$, $D_{2p}$ is the dihedral group of order $2p$, and * is the canonical
involution of the group algebra $FD_{2p}$. We also provide the structure of the
maximal $p$-subgroup of the unit group $\mathscr{U}(FD_{2p})$ and compute a
basis of its center.


title:
High energy emission of GRB 130427A: evidence for inverse Compton
  radiation

abstract:
  A nearby super-luminous burst GRB 130427A was simultaneously detected by six
$\gamma$-ray space telescopes ({\it Swift}, Fermi-GBM/LAT, Konus-Wind,
SPI-ACS/INTEGRAL, AGILE and RHESSI) and by three RAPTOR full-sky persistent
monitors. The isotropic $\gamma-$ray energy release is of $\sim 10^{54}$ erg,
rendering it the most powerful explosion among the GRBs with a redshift $z\leq
0.5$. The emission above 100 MeV lasted about one day and four photons are at
energies greater than 40 GeV. We show that the count rate of 100 MeV-100 GeV
emission may be mainly accounted for by the forward shock synchrotron radiation
and the inverse Compton radiation likely dominates at GeV-TeV energies. In
particular, an inverse Compton radiation origin is established for the $\sim
(95.3,~47.3,~41.4,~38.5,~32)$ GeV photons arriving at $t\sim
(243,~256.3,~610.6,~3409.8,~34366.2)$ s after the trigger of Fermi-GBM.
Interestingly, the external-inverse-Compton-scattering of the prompt emission
(the second episode, i.e., $t\sim 120-260$ s) by the forward-shock-accelerated
electrons is expected to produce a few $\gamma-$rays at energies above 10 GeV,
while five were detected in the same time interval. A possible unified model
for the prompt soft $\gamma-$ray, optical and GeV emission of GRB 130427A, GRB
080319B and GRB 090902B is outlined. Implication of the null detection of $>1$
TeV neutrinos from GRB 130427A by IceCube is discussed.


title:
Weakening the Born Rule - Towards a Stateless Formulation of Quantum
  Mechanics

abstract:
  The notion of state vector is, in quantum mechanics, as central as it is
problematic, as illustrates the wealth of publications about the sub- jects,
including in particular the many attempts to obtain an acceptable
interpretation of quantum mechanics. In this article, we propose a different
approach, and initiate the study of a formulation of quantum mechanics, where
the notion of state is entirely replaced by assertions about measurement
outcomes. We define a notion of "verification" which represents the knowledge
that one may have about the possible outcomes of the measurements performed on
a quantum system, and express a set of logical rules which allow to reason
about quantum systems using verification assertions only, and thus making no
reference to the problematic notion of state.


title:
Bipolar jets launched from accretion disks. II. Formation of symmetric
  and asymmetric jets and counter jets

abstract:
  We investigate the jet launching process from accretion disks extending our
recent study (paper I) to a truly bipolar setup. We perform axisymmetric MHD
simulations of the disk-jet interaction on a computational domain covering both
hemispheres, in particular addressing the question of an intrinsically
asymmetric origin of jet / counter jet systems. Treating both hemispheres
simultaneously, we overcome the equatorial plane symmetry boundary condition
used in most previous studies which naturally fosters a symmetric evolution.
For the magnetic diffusivity prescription we apply an alpha-parametrisation,
considering both, globally models of diffusivity, and local models. We first
approve the quality of our numerical setup by generating perfectly symmetric
jets, lasting over a 1000s of dynamical time scales. We then disturb the
hemispheric symmetry in the disk, and investigate the subsequent evolution of
the outflow. The evolution first leads to a substantial disk warping with
electric currents intersecting the equatorial plane. We investigate two models,
i) a disk with (initially) different thermal scale height in both hemispheres,
and ii) a symmetric disk into which a local disturbance is injected in one
hemisphere. In both cases the disk asymmetry results in asymmetric outflows
with mass fluxes differing by 10-20%. We find up to 30% difference in mass flux
between jet and counter jet for this setup, lasting over 1000s of dynamical
time scales (i.e. lasting for the whole simulation). In summary, our results
suggest that the jet asymmetries in protostellar and extragalactic jets can
indeed be generated intrinsically and maintained over long time by disk
asymmetries and the standard jet launching mechanism.


title:
Transformation Property of the Caputo Fractional Differential Operator
  in Two Dimensional Space

abstract:
  The transformation property of the Caputo fractional derivative operator of a
scalar function under rotation in two dimensional space is derived. The study
of the transformation property is essential for the formulation of fractional
calculus in multi-dimensional space. The inclusion of fractional calculus in
the Lagrangian and Hamiltonian dynamics relies on such transformation. An
illustrative example is given.


title:
Moriwaki divisors and the augmented base loci of divisors on the moduli
  space of curves

abstract:
  We study the cone of Moriwaki divisors on \bar{M}_g by means of augmented
base loci. Using a result of Moriwaki, we prove that an R-divisor D satisfies
the strict Moriwaki inequalities if and only if the augmented base locus of D
is contained in the boundary of \bar{M}_g. Then we draw some interesting
consequences on the Zariski decomposition of divisors on \bar{M}_g, on the
minimal model program of \bar{M}_g and on the log canonical models
\bar{M}_g(\alpha).


title:
Global existence and blow-up of solutions to some quasilinear wave
  equation in one space dimension

abstract:
  We consider the global existence and blow up of solutions of the Cauchy
problem of the quasilinear wave equation: $\partial_{t}^2 u = \partial_x(c(u)^2
\partial_x u)$, which has richly physical backgrounds. Under the assumption
that $c(u(0,x))\geq \delta$ for some $\delta>0$, we give sufficient conditions
for the existence of global smooth solutions and the occurrence of two types of
blow-up respectively. One of the two types is that $L^{\infty}$-norm of
$\partial_t u$ or $\partial_x u$ goes up to the infinity. The other type is
that $c(u)$ vanishes, that is, the equation degenerates.


title: Healthy sweet inhibitor of Plasmodium falciparum aquaglyceroporin

abstract:
  Plasmodium falciparum aquaglyceroporin (PfAQP) is a multifunctional channel
protein in the plasma membrane of the malarial parasite that causes the most
severe form of malaria infecting more than a million people a year. Finding a
novel way to inhibit PfAQP, I conducted 3+ microseconds in silico experiments
of an atomistic model of the PfAQP-membrane system and computed the
chemical-potential profiles of six permeants (erythritol, water, glycerol,
urea, ammonia, and ammonium) that can be efficiently transported across P.
falciparum's plasma membrane through PfAQP's conducting pore. The profiles show
that, with all the existent in vitro data being supportive, erythritol, a
permeant of PfAQP itself having a deep ditch in its permeation passageway,
strongly inhibits PfAQP's functions of transporting water, glycerol, urea,
ammonia, and ammonium (The IC50 is in the range of high nanomolars). This
suggests the possibility that erythritol, a sweetener generally considered
safe, may be the drug needed to kill the malarial parasite in vivo without
causing serious side effects.


title: A Contraction Analysis of the Convergence of Risk-Sensitive Filters

abstract:
  A contraction analysis of risk-sensitive Riccati equations is proposed. When
the state-space model is reachable and observable, a block-update
implementation of the risk-sensitive filter is used to show that the N-fold
composition of the Riccati map is strictly contractive with respect to the
Riemannian metric of positive definite matrices, when N is larger than the
number of states. The range of values of the risk-sensitivity parameter for
which the map remains contractive can be estimated a priori. It is also found
that a second condition must be imposed on the risk-sensitivity parameter and
on the initial error variance to ensure that the solution of the risk-sensitive
Riccati equation remains positive definite at all times. The two conditions
obtained can be viewed as extending to the multivariable case an earlier
analysis of Whittle for the scalar case.


title:
A transformative superconducting magnet technology for fields well above
  30 T using isotropic round wire multifilament Bi2Sr2CaCu2O8-x conductor

abstract:
  We report here that magnetic fields of almost 34 T, far above the upper 24 T
limit of Nb3Sn, can be generated using a multifilament round wire conductor
made of the high temperature cuprate superconductor Bi2Sr2CaCu2O8-x (Bi-2212).
A remarkable attribute of this Bi-2212 conductor is that it does not exhibit
macroscopic texture and contains many high angle grain boundaries but
nevertheless attains very high superconducting critical current densities Jc of
2500 A/mm2 at 20 T and 4.2 K. This Bi-2212 conductor does not possess the
extreme texture that high Jc coated conductors of REBa2Cu3O7-x (REBCO) require,
avoiding also its high aspect ratio, large superconducting anisotropy and the
inherent sensitivity to defects of a single filament conductor. Bi-2212 wires
can be wound or cabled into almost any type of superconducting magnet and will
be especially valuable for very high field NMR magnets beyond the present 1 GHz
proton resonance limit of Nb3Sn technology. This demonstration that grain
boundary limits to high Jc can be practically overcome suggests the huge value
of a renewed focus on grain boundary properties in non-ideal geometries,
especially with the goal of translating the lessons of this Bi-2212 conductor
into fabrication of multifilament round wire REBCO or Fe-based superconductors.


title:
An Encryption Scheme with DNA Technology and JPEG Zigzag Coding for
  Secure Transmission of Images

abstract:
  The Internet is a ubiquitous and affordable communications network suited for
e-commerce and medical image communications. Security has become a major issue
as data communication channels can be intruded by intruders during
transmission. Though, different methods have been proposed and used to protect
the transmission of data from illegal and unauthorized access, code breakers
have come up with various methods to crack them. DNA based Cryptography brings
forward a new hope for unbreakable algorithms. This paper outlines an
encryption scheme with DNA technology and JPEG Zigzag Coding for Secure
Transmission of Images.


title:
Halo Coupling and Cleaning by a Space Charge Resonance in High Intensity
  Beams

abstract:
  We show that the difference resonance driven by the space charge
pseudo-octupole of high-intensity beams not only couples the beam core
emittances; it can also lead to emittance exchange in the beam halo, which is
of relevance for beam loss in high intensity accelerators. With reference to
linear accelerators the "main resonance" kz/kxy =1 (corresponding to the
Montague resonance 2Qx-2Qy=0 in circular accelerators) may lead to such a
coupling and transfer of halo between planes. Coupling of transverse halo into
the longitudinal plane - or vice versa - can occur even if the core (rms)
emittances are exactly or nearly equal. This halo argument justifies additional
caution in linac design including consideration of avoiding an equipartitioned
design. At the same time, however, this mechanism may also qualify as active
dynamical halo cleaning scheme by coupling a halo from the longitudinal plane
into the transverse plane, where local scraping is accessible. We present
semi-analytical emittance coupling rates and show that previously developed
linac stability charts for the core can be extended - using the longitudinal to
transverse halo emittance ratio - to indicate additional regions where halo
coupling could be of importance.


title:
Computational investigation of plastic deformation in face-centered
  cubic materials

abstract:
  A mathematical model of plastic deformation in face-centered cubic (FCC)
materials based on a balance model taking into account fundamental properties
of deformation defects of a crystal lattice was developed. This model is based
on a system of ordinary differential equations (ODE) accounting for various
mechanisms of generation and annihilation of deformation defects for different
external conditions. In-house developed software, SPFCC (Slip Plasticity of
Face-Centered Cubic), was employed to solve the system of ordinary differential
equations. The implemented code solves efficiently the stiff ODE system and
provides a user-friendly interface for investigation of various features of
plastic deformation in FCC materials. Simulation of plastic deformation in the
FCC metals was performed for the case of constant strain rate. The modelling
results were validated by comparing experimental data and simulation results
(stress-strain curves) and good agreement was obtained.


title: The Calderon problem in transversally anisotropic geometries

abstract:
  We consider the anisotropic Calderon problem of recovering a conductivity
matrix or a Riemannian metric from electrical boundary measurements in three
and higher dimensions. In the earlier work \cite{DKSaU}, it was shown that a
metric in a fixed conformal class is uniquely determined by boundary
measurements under two conditions: (1) the metric is conformally transversally
anisotropic (CTA), and (2) the transversal manifold is simple. In this paper we
will consider geometries satisfying (1) but not (2). The first main result
states that the boundary measurements uniquely determine a mixed Fourier
transform / attenuated geodesic ray transform (or integral against a more
general semiclassical limit measure) of an unknown coefficient. In particular,
one obtains uniqueness results whenever the geodesic ray transform on the
transversal manifold is injective. The second result shows that the boundary
measurements in an infinite cylinder uniquely determine the transversal metric.
The first result is proved by using complex geometrical optics solutions
involving Gaussian beam quasimodes, and the second result follows from a
connection between the Calderon problem and Gel'fand's inverse problem for the
wave equation and the boundary control method.


title:
Liquid-like correlations in single crystalline Y2Mo2O7: an
  unconventional spin glass

abstract:
  The spin glass behavior of Y2Mo2O7 has puzzled physicists for nearly three
decades. Free of bulk disorder within the resolution of powder diffraction
methods, it is thought that this material is a rare realization of a spin glass
resulting from weak disorder such as bond disorder or local lattice
distortions. Here, we report on the single crystal growth of Y2Mo2O7. Using
neutron scattering, we present unique isotropic magnetic diffuse scattering
arising beneath the spin glass transition despite having a well-ordered
structure at the bulk level. Despite our attempts to model the diffuse
scattering using a computationally exhaustive search of a class of simple spin
Hamiltonians, we were unable to replicate the experimentally observed
energy-integrated (diffuse) neutron scattering. A T^2-temperature dependence in
the heat capacity and density functional theory calculations hint at
significant frozen degeneracy in both the spin and orbital degrees of freedom
resulting from spin-orbital coupling (Kugel-Khomskii type) and random
fluctuations in the Mo environment at the local level.


title: The most complete and detailed X-ray view of the SNR Puppis A

abstract:
  With the purpose of producing the first detailed full view of Puppis A in
X-rays, we carried out new XMM-Newton observations covering the missing regions
in the southern half of the supernova remnant (SNR) and combined them with
existing XMM-Newton and Chandra data. The new images were produced in the
0.3-0.7, 0.7-1.0 and 1.0-8.0 energy bands. We investigated the SNR morphology
in detail, carried out a multi-wavelength analysis and estimated the flux
density and luminosity of the whole SNR. The complex structure observed across
the remnant confirms that Puppis A evolves in an inhomogeneous, probably knotty
interstellar medium. The southwestern corner includes filaments that perfectly
correlate with radio features suggested to be associated with shock/cloud
interaction. In the northern half of Puppis A the comparison with Spitzer
infrared images shows an excellent correspondence between X-rays and 24 and 70
microns emission features, while to the south there are some matched and other
unmatched features. X-ray flux densities of 12.6 X 10^-9, 6.2 X 10^-9, and 2.8
X 10^-9 erg cm^-2 s^-1 were derived for the 0.3-0.7, 0.7-1.0 and 1.0-8.0 keV
bands, respectively. At the assumed distance of 2.2 kpc, the total X-ray
luminosity between 0.3 and 8.0 keV is 1.2 X 10^37 erg s^-1. We also collected
and updated the broad-band data of Puppis A between radio and GeV gamma-ray
range, producing its spectral energy distribution. To provide constraints to
the high-energy emission models, we re-analyzed radio data, estimating the
energy content in accelerated particles to be Umin=4.8 X 10^49 erg and the
magnetic field strength B=26 muG.


title:
An Infinite-Dimensional Variational Inequality Formulation and Existence
  Result for Dynamic User Equilibrium with Elastic Demands

abstract:
  This paper is concerned with dynamic user equilibrium (DUE) with elastic
travel demand (E-DUE). We present and prove a variational inequality (VI)
formulation of E-DUE using measure-theoretic argument. Moreover, existence of
the E-DUE is formally established with a version of Brouwer's fixed point
theorem in a properly defined Hilbert space. The existence proof requires the
effective delay operator to be continuous, a regularity condition also needed
to ensure the existence of DUE with fixed demand (Han et al., 2013c). Our proof
does not invoke the a priori upper bound of the departure rates (path flows).


title: Higher Spin Resolution of a Toy Big Bang

abstract:
  Diffeomorphisms preserve spacetime singularities, whereas higher spin
symmetries need not. Since three dimensional de Sitter space has quotients that
have big-bang/big-crunch singularities and since dS_3-gravity can be written as
an SL(2,C) Chern-Simons theory, we investigate SL(3,C) Chern-Simons theory as a
higher-spin context in which these singularities might get resolved. As in the
case of higher spin black holes in AdS_3, the solutions are invariantly
characterized by their holonomies. We show that the dS_3 quotient singularity
can be de-singularized by an SL(3,C) gauge transformation that preserves the
holonomy: this is a higher spin resolution the cosmological singularity. Our
work deals exclusively with the bulk theory, and is independent of the
subtleties involved in defining a CFT_2 dual to dS_3 in the sense of dS/CFT.


title: Quantisation of the effective string with TBA

abstract:
  In presence of a static pair of sources, the spectrum of low-lying states of
whatever confining gauge theory in D space-time dimensions is described, at
large source separations, by an effective string theory. In the far infrared
the latter flows, in the static gauge, to a two-dimensional massless free-field
theory. It is known that the Lorentz invariance of the gauge theory fixes
uniquely the first few subleading corrections of this free-field limit. We
point out that the first allowed correction - a quartic polynomial in the field
derivatives - is exactly the composite field $T\bar{T}$, built with the chiral
components, $T$ and $\bar{T}$, of the energy-momentum tensor. This irrelevant
perturbation is quantum integrable and yields, through the thermodynamic Bethe
Ansatz (TBA),the energy levels of the string which exactly coincide with the
Nambu-Goto spectrum. We obtain this way the results recently found by Dubovsky,
Flauger and Gorbenko. This procedure easily generalizes to any two-dimensional
CFT. It is known that the leading deviation of the Nambu-Goto spectrum comes
from the boundary terms of the string action. We solve the TBA equations on an
infinite strip, identify the relevant boundary parameter and verify that it
modifies the string spectrum as expected.


title:
Weak-coupling analysis of the single-site large-N gauge theory coupled
  to adjoint fermions

abstract:
  We consider the leading-order expression at weak-coupling for a single-site
large-N gauge theory coupled to adjoint fermions. We study the case of overlap
and wilson fermions. We extend the theory to real values of the number of
fermion flavors and restrict ourselves to asymptotically free theories. Using a
four-dimensional density function for the distribution of the eigenvalues of
the link variables, we show that it is possible to recover the infinite-volume
continuum limit for a certain range of fermion flavors if we use fermions with
a bare mass of zero. Our use of the four-dimensional density function is
supported by a direct analysis of the lattice action.


title: The Pilot-Wave Perspective on Spin

abstract:
  The alternative pilot-wave theory of quantum phenomena -- associated
especially with Louis de Broglie, David Bohm, and John Bell -- reproduces the
statistical predictions of ordinary quantum mechanics, but without recourse to
special \emph{ad hoc} axioms pertaining to measurement. That (and how) it does
so is relatively straightforward to understand in the case of position
measurements and, more generally, measurements whose outcome is ultimately
registered by the position of a pointer. Despite a widespread belief to the
contrary among physicists, the theory can also account successfully for
phenomena involving spin. The main goal of the paper is to explain how the
pilot-wave theory's account of spin works. Along the way, we provide
illuminating comparisons between the orthodox and pilot-wave accounts of spin
and address some puzzles about how the pilot-wave theory relates to the
important theorems of Kochen and Specker and Bell.


title: Breaking so(4) symmetry without degeneracy lift

abstract:
  We argue that in the quantum motion of a scalar particle of mass "m" on S^3_R
perturbed by the trigonometric Scarf potential (Scarf I) with one internal
quantized dimensionless parameter, \ell, the 3D orbital angular momentum, and
another, an external scale introducing continuous parameter, B, a loss of the
geometric hyper-spherical so(4) symmetry of the free motion can occur that
leaves intact the unperturbed {\mathcal N}^2-fold degeneracy patterns, with
{\mathcal N}=(\ell +n+1) and n denoting the nodes number of the wave function.
Our point is that although the number of degenerate states for any {\mathcal N}
matches dimensionality of an irreducible so(4) representation space, the
corresponding set of wave functions do not transform irreducibly under any
so(4). Indeed, in expanding the Scarf I wave functions in the basis of properly
identified so(4) representation functions, we find power series in the
perturbation parameter, B, where 4D angular momenta K\in [\ell , {\mathcal
N}-1] contribute up to the order \left(\frac{2mR^2B}{\hbar^2}\right)^{{\mathcal
N}-1-K}. In this fashion, we work out an explicit example on a symmetry
breakdown by external scales that retains the degeneracy. The scheme extends to
so(d+2) for any d.


title: Anisotropy of Interfacial Energy in Five Dimensions

abstract:
  Anisotropy of interfacial energy is the principal driving force for material
microstructure evolution yet its origins remain uncertain and a quantitative
description lacking. We present and justify a concise hypothesis on the
topography and topology of the functional space of grain boundary energies and,
based on this hypothesis, construct a closed-form function that quantitatively
describes energy variations in the entire 5-space of macroscopic parameters
defining grain boundary geometry. The new function is found to be universal for
the crystallography class of face-centered cubic metals.


title:
An analytic solution to the equations governing the motion of a point
  mass with quadratic resistance and generalizations

abstract:
  The paper is devoted to the motion of a body in a fluid under the influence
of gravity and drag. Depending on the regime considered, the drag force can
exhibit a linear, quadratic or even more general dependence on the velocity of
the body relative to the fluid. The case of quadratic drag is substantially
more complex than the linear case, as it nonlinearly couples both components of
the momentum equation. Careful screening of the literature on this classical
topic showed that, unexpectedly, the solutions reported do not directly provide
the particle velocity as a function of time but use auxiliary quantities or
apply to special cases only. No explicit solution using elementary operations
on analytical expressions is known for a general trajectory. After a detailed
account of the literature, the paper provides such a solution in form of a
ratio of two series expansions. This result is discussed in detail and related
to previous approaches. In particular, it is shown to yield, as limiting cases,
certain approximate solutions proposed in the literature. The solution
technique employs a strategy to reduce systems of ordinary differential
equations with a triangular dependence of the right-hand side on the vector of
unknowns to a single equation in an auxiliary variable. For the particular case
of quadratic drag, the auxiliary variable allows an interpretation in terms of
canonical coordinates of motion within the framework of Hamiltonian mechanics.
Another result of the paper is the extension of the solution technique to more
general drag laws, such as general power laws or power laws with an additional
linear contribution. Furthermore, generalization to variable velocity of the
surrounding fluid is addressed by considering a linear velocity profile for
which a solution is provided as well. Throughout, the results obtained are
illustrated by numerical examples.


title:
Solving the continuous nonlinear resource allocation problem with an
  interior point method

abstract:
  Resource allocation problems are usually solved with specialized methods
exploiting their general sparsity and problem-specific algebraic structure. We
show that the sparsity structure alone yields a closed-form Newton search
direction for the generic primal-dual interior point method. Computational
tests show that the interior point method consistently outperforms the best
specialized methods when no additional algebraic structure is available.


title:
Casimir Force for Arbitrary Objects Using the Argument Principle and
  Boundary Element Methods

abstract:
  Recent progress in the simulation of Casimir forces between various objects
has allowed traditional computational electromagnetic solvers to be used to
find Casimir forces in arbitrary three-dimensional objects. The underlying
theory to these approaches requires knowledge and manipulation of quantum field
theory and statistical physics. We present a calculation of the Casimir force
using the method of moments via the argument principle. This simplified
derivation allows greater freedom in the moment matrix where the argument
principle can be used to calculate Casimir forces for arbitrary geometries and
materials with the use of various computational electromagnetic techniques.


title:
KRAS mutation testing in colorectal cancer as an example of the
  pathologist's role in personalized targeted therapy: a practical approach

abstract:
  Identifying targets for personalized targeted therapy is the pathologist's
domain and a treasure. For decades, pathologists have had to learn, understand,
adopt and implement many new laboratory techniques as they arrived on the
scene. Pathologists successfully integrate the results of those tests into
final pathology reports that were, and still are, the basis of clinical
therapeutic decisions. The molecular methods are different but no more
difficult to comprehend in the era of "kit procedures". Pathologists have the
knowledge and expertise to identify particular gene mutations using the
appropriate molecular tests currently available. This review focuses on the
most important recent developments in KRAS mutation testing in metastatic
colorectal cancer (CRC), and shows that a pathologist is involved in 10 stages
of this procedure. Recent studies have shown that highly sensitive, simple,
reliable and rapid assays may significantly improve the identification of CRC
patients resistant to anti-EGFR therapy. Thus, direct sequencing does not seem
to be an optimal procedure of KRAS testing for clinical purposes. Twelve
currently available high-sensitivity diagnostic assays (with the CE-IVD mark)
for KRAS mutation testing are briefly described and compared. The suggested
pathology report content for somatic mutation tests is described. In
conclusion, evidence is presented that sending away paraffin blocks with tumor
tissue for KRAS mutation testing may not be in the best interest of patients.
Instead, an evidence-based approach indicates that KRAS mutation testing should
be performed in pathology departments, only with the use of CE-IVD/FDA-approved
KRAS tests, and with the obligatory, periodic participation in the KRAS EQA
scheme organized by the European Society of Pathology as an independent
international body.


title: Coisotropic rigidity and C^0-symplectic geometry

abstract:
  We prove that symplectic homeomorphisms, in the sense of the celebrated
Gromov-Eliashberg Theorem, preserve coisotropic submanifolds and their
characteristic foliations. This result generalizes the Gromov-Eliashberg
Theorem and demonstrates that previous rigidity results (on Lagrangians by
Laudenbach-Sikorav, and on characteristics of hypersurfaces by Opshtein) are
manifestations of a single rigidity phenomenon. To prove the above, we
establish a C^0-dynamical property of coisotropic submanifolds which
generalizes a foundational theorem in C^0-Hamiltonian dynamics: Uniqueness of
generators for continuous analogs of Hamiltonian flows.


title:
Decelerated invasion and waning moon patterns in public goods games with
  delayed distribution

abstract:
  We study the evolution of cooperation in the spatial public goods game,
focusing on the effects that are brought about by the delayed distribution of
goods that accumulate in groups due to the continuous investments of
cooperators. We find that intermediate delays enhance network reciprocity
because of a decelerated invasion of defectors, who are unable to reap the same
high short-term benefits as they do in the absence of delayed distribution.
Long delays, however, introduce a risk because the large accumulated wealth
might fall into the wrong hands. Indeed, as soon as the curvature of a
cooperative cluster turns negative, the engulfed defectors can collect the
heritage of many generations of cooperators, and by doing so start a waning
moon pattern that nullifies the benefits of decelerated invasion. Accidental
meeting points of growing cooperative clusters may also act as triggers for the
waning moon effect, thus linking the success of cooperators with their
propensity to fail in a rather bizarre way. Our results highlight that
"investing into the future" is a good idea only if that future is sufficiently
near and not likely to be burdened by inflation.

categories: physics.soc-ph cond-mat.stat-mech cs.SI q-bio.PE


title:
The Moment Generating function for ray lengths in the Half Gilbert Model
  with Rectangular Cells

abstract:
  In the full rectangular version of Gilbert's tessellation lines extend either
horizontally (with east- and west--growing rays) or vertically (north- and
south--growing rays) from seed points which form a Poisson point process, each
ray stopping when another ray is met. In the half rectangular version, east and
south growing rays do not interact with west and north rays. Using techniques
developed in our previous paper, we derive an exact expression for the moment
generating function for the ray length distribution in the half rectangular
model.


title: Topological order in a correlated Chern insulator

abstract:
  We study the effect of electron-electron interactions in a spinful Chern
insulator. For weak on-site repulsive interactions at half-filling, the system
is a weakly correlated Chern insulator adiabatically connected to the
noninteracting ground state, while in the limit of infinitely strong repulsion
the system is described by an effective spin model recently predicted to
exhibit a chiral spin liquid ground state. In the regime of large but finite
repulsion, we find an exotic gapped phase with characteristics partaking of
both the noninteracting Chern insulator and the chiral spin liquid. This phase
has an integer quantized Hall conductivity $2e^2/h$ and quasiparticles with
electric charges that are integer multiples of the electron charge $e$, but the
ground state on the torus is four-fold degenerate and quasiparticles have
fractional statistics. We discuss how these unusual properties affect the
outcome of a charge pumping experiment and, by deriving the topological field
theory, elucidate that the topological order is of the exotic $\mathbb{Z}_2$
double-semion type.


title: Mathematical structure of unit systems

abstract:
  We investigate the mathematical structure of unit systems and the relations
between them. Looking over the entire set of unit systems, we can find a
mathematical structure that is called preorder (or quasi-order). For some pair
of unit systems, there exists a relation of preorder such that one unit system
is transferable to the other unit system. The transfer (or conversion) is
possible only when all of the quantities distinguishable in the latter system
are always distinguishable in the former system. By utilizing this structure,
we can systematically compare the representations in different unit systems.
Especially, the equivalence class of unit systems (EUS) plays an important role
because the representations of physical quantities and equations are of the
same form in unit systems belonging to an EUS. The dimension of quantities is
uniquely defined in each EUS. The EUS's form a partially ordered set. Using
these mathematical structures, unit systems and EUS's are systematically
classified and organized as a hierarchical tree.


title:
A well-posedness result for hyperbolic operators with Zygmund
  coefficients

abstract:
  In this paper we prove an energy estimate with no loss of derivatives for a
strictly hyperbolic operator with Zygmund continuous second order coefficients
both in time and in space. In particular, this estimate implies the
well-posedness for the related Cauchy problem. On the one hand, this result is
quite surprising, because it allows to consider coefficients which are not
Lipschitz continuous in time. On the other hand, it holds true only in the very
special case of initial data in $H^{1/2}\times H^{-1/2}$. Paradifferential
calculus with parameters is the main ingredient to the proof.


title: Parallel Chen-Han (PCH) Algorithm for Discrete Geodesics

abstract:
  In many graphics applications, the computation of exact geodesic distance is
very important. However, the high computational cost of the existing geodesic
algorithms means that they are not practical for large-scale models or
time-critical applications. To tackle this challenge, we propose the parallel
Chen-Han (or PCH) algorithm, which extends the classic Chen-Han (CH) discrete
geodesic algorithm to the parallel setting. The original CH algorithm and its
variant both lack a parallel solution because the windows (a key data structure
that carries the shortest distance in the wavefront propagation) are maintained
in a strict order or a tightly coupled manner, which means that only one window
is processed at a time. We propose dividing the CH's sequential algorithm into
four phases, window selection, window propagation, data organization, and
events processing so that there is no data dependence or conflicts in each
phase and the operations within each phase can be carried out in parallel. The
proposed PCH algorithm is able to propagate a large number of windows
simultaneously and independently. We also adopt a simple yet effective strategy
to control the total number of windows. We implement the PCH algorithm on
modern GPUs (such as Nvidia GTX 580) and analyze the performance in detail. The
performance improvement (compared to the sequential algorithms) is highly
consistent with GPU double-precision performance (GFLOPS). Extensive
experiments on real-world models demonstrate an order of magnitude improvement
in execution time compared to the state-of-the-art.


title: Topological Superconductors in Correlated Chern Insulators

abstract:
  In this paper, we realize a topological superconductor (TSC) in correlated
topological insulator - the interacting spinful Haldane model. We consider the
electrons on the Haldane model with on-site negative-U interaction and then
study its properties by mean field theory and random-phase-approximation (RPA)
approach. We found that in the intermediate interaction region, the ground
state becomes a TSC with the Chern number 2. We also study its edge states and
the zero modes of the pi-flux.


title:
Tight Lower Bounds for Greedy Routing in Higher-Dimensional Small-World
  Grids

abstract:
  We consider Kleinberg's celebrated small world graph model (Kleinberg, 2000),
in which a D-dimensional grid {0,...,n-1}^D is augmented with a constant number
of additional unidirectional edges leaving each node. These long range edges
are determined at random according to a probability distribution (the
augmenting distribution), which is the same for each node. Kleinberg suggested
using the inverse D-th power distribution, in which node v is the long range
contact of node u with a probability proportional to ||u-v||^(-D). He showed
that such an augmenting distribution allows to route a message efficiently in
the resulting random graph: The greedy algorithm, where in each intermediate
node the message travels over a link that brings the message closest to the
target w.r.t. the Manhattan distance, finds a path of expected length O(log^2
n) between any two nodes. In this paper we prove that greedy routing does not
perform asymptotically better for any uniform and isotropic augmenting
distribution, i.e., the probability that node u has a particular long range
contact v is independent of the labels of u and v and only a function of
||u-v||.
  In order to obtain the result, we introduce a novel proof technique: We
define a budget game, in which a token travels over a game board, while the
player manages a "probability budget". In each round, the player bets part of
her remaining probability budget on step sizes. A step size is chosen at random
according to a probability distribution of the player's bet. The token then
makes progress as determined by the chosen step size, while some of the
player's bet is removed from her probability budget. We prove a tight lower
bound for such a budget game, and then obtain a lower bound for greedy routing
in the D-dimensional grid by a reduction.