title:
Nb nano superconducting quantum interference devices with high spin
  sensitivity for operation in magnetic fields up to 0.5\,T

abstract:
  We investigate electric transport and noise properties of microstrip-type
submicron direct current superconducting quantum interference devices (dc
SQUIDs) based on Nb thin films and overdamped Josephson junctions with a HfTi
barrier. The SQUIDs were designed for optimal spin sensitivity $S_\mu^{1/2}$
upon operation in intermediate magnetic fields $B$ (tens of mT), applied
perpendicular to the substrate plane. Our so far best SQUID can be continuously
operated in fields up to $B\approx\pm50\,\rm{mT}$ with rms flux noise
$S_{\Phi,\rm w}^{1/2}\leq250\,\rm{n\Phi_0/Hz^{1/2}}$ in the white noise regime
and spin sensitivity $S_{\mu}^{1/2}\leq29\,\rm{\mu_B/Hz^{1/2}}$. Furthermore,
we demonstrate operation in $B=0.5\,\rm{T}$ with high sensitivity in flux
$S_{\Phi,\rm w}^{1/2}\approx680\,\rm{n\Phi_0/Hz^{1/2}}$ and in electron spin
$S_{\mu}^{1/2}\approx79\,\rm{\mu_B/Hz^{1/2}}$. We discuss strategies to further
improve the nanoSQUID performance.


title: A categorification of the ribbon element in quantum sl(2)

abstract:
  We define a bicomplex whose Euler characteristic is the idempotented version
of the ribbon element of quantum sl(2). We show that properties of this
bicomplex descend to the centrality, invertibility and symmetries of the ribbon
element after decategorification.


title:
Revisiting Fizeaus Observations: Spectral study of Na source using
  Newtons rings

abstract:
  Conventional Newtons rings is generally used in undergraduate laboratory to
determine the average wavelength of Na doublet. A minor modification of this
setup enables us to view simultaneously Newtons rings both in reflected as well
as transmitted light. A movable glass plate with respect to the plano-convex
lens allows us to observe the variation of contrast/visibility of these fringes
and thus allows us to determine the separation of the yellow doublet.


title: Roots of the Ehrhart polynomial of hypersimplices

abstract:
  The Ehrhart polynomial of the $d$-th hypersimplex $\Delta(d,n)$ of order $n$
is studied. By computational experiments and a known result for $d=2$, we
conjecture that the real part of every roots of the Ehrhart polynomial of
$\Delta(d,n)$ is negative and larger than $- \frac{n}{d}$ if $n \geq 2d$. In
this paper, we show that the conjecture is true when $d=3$ and that every root
$a$ of the Ehrhart polynomial of $\Delta(d,n)$ satisfies $-\frac{n}{d} < {\rm
Re} (a) < 1$ if $4 \leq d \ll n$.


title: On the incenters of triangular orbits in elliptic billiard

abstract:
  We consider 3-periodic orbits in an elliptic billiard. Numerical experiments
conducted by Dan Reznik have shown that the locus of the centers of inscribed
circles of the corresponding triangles is an ellipse. We prove this fact by the
complexification of the problem coupled with the complex law or rfelection.


title: Limit shapes of bumping routes in the Robinson-Schensted correspondence

abstract:
  We prove a limit shape theorem describing the asymptotic shape of bumping
routes when the Robinson-Schensted algorithm is applied to a finite sequence of
independent, identically distributed random variables with the uniform
distribution $U[0,1]$ on the unit interval, followed by an insertion of a
deterministic number $\alpha$. The bumping route converges after scaling, in
the limit as the length of the sequence tends to infinity, to an explicit,
deterministic curve depending only on $\alpha$. This extends our previous
result on the asymptotic determinism of Robinson-Schensted insertion, and
answers a question posed by Moore in 2006.


title: Revisiting Timed Specification Theory II : Realisability

abstract:
  In this paper we present an assume-guarantee specification theory (aka
interface theory from [14]) for modular synthesis and verification of real-time
systems with critical timing constraints. It is a further step of our earlier
work [10] which achieved an elegant algebraic specification theory for
real-time systems endowed with the capability to freeze time. In this paper we
relinquish such (unrealisable) capability and target more realistic systems
without the ability to stop time.
  Our theory, in a combined process-algebraic and reactive-synthesis style,
provides the operations of parallel composition for system integration, logical
conjunction/disjunction for viewpoint fusion and independent development, and
quotient for incremental synthesis.
  We show that a substitutive refinement preorder, which is a coarsening of the
pre-congruence in [10], constitutes the weakest pre-congruence preserving
freedom of incompatibility errors. The coarsening requires a shift in the focus
of our theory to a more game-theoretical treatment, where the coarsening
constitutes a reactive synthesis game named normalisation and is efficiently
implementable by a novel local bot-backpropagation algorithm.
  Previously, timed concurrent games have been studied in [1,14,13], where one
of the key concern is the removal of time-blocking strategies by applying blame
assignment [13]. Our timed games also have the issue of time-blocking
strategies, which may arise through the composition of specifications. However,
due to our distinctively different formulation of timed games, we have
discovered another elegant solution to the problem without blame assignment.
Our solution utilises a second reactive synthesis game called realisation,
which is dual to normalisation and implementable by the dual local
top-backpropagation algorithm.


title:
Parity nonconservation in Fr-like actinide and Cs-like rare-earth-metal
  ions

abstract:
  Parity nonconservation amplitudes are calculated for the 7s-6d transitions of
the francium isoelectronic sequence (Fr, Ra +, Ac 2+, Th 3+, Pa 4+, U 5+ and Np
6+) and for the 6s-5d transitions of the cesium isoelectronic sequence (Cs, Ba
+, La 2+, Ce 3+ and Pr 4+). We show in particular that isotopes of La 2+, Ac 2+
and Th 3+ ions have strong potential in the search for new physics beyond the
standard model - the PNC amplitudes are large, the calculations are accurate
and the nuclei are practically stable. In addition, 232-Th 3+ ions have
recently been trapped and cooled [C. J. Campbell et al., Phys. Rev. Lett. 102,
233004 (2009)]. We also extend previous works by calculating the s-s PNC
transitions in Ra + and Ba +, and provide new calculations of several energy
levels, and electric dipole and quadrupole transition amplitudes for the
Fr-like actinide ions.


title:
Completely flat bands and fully localized states on surfaces of
  anisotropic diamond-lattice models

abstract:
  We discuss flat-band surface states on the (111) surface in the tight-binding
model with nearest-neighbor hopping on the diamond lattice, in analogy to the
flat-band edge states in graphene with a zigzag edge. The bulk band is gapless,
and the gap closes along a loop in the Brillouin zone. The verge of the
flat-band surface states is identical with this gap-closing loop projected onto
the surface plane. When anisotropies in the hopping integrals increase, the
bulk gap-closing points move and the distribution of the flat-band states
expands in the Brillouin zone. Then when the anisotropy is sufficiently large,
the surface flat bands cover the whole Brillouin zone. Because of the
completely flat bands, we can construct surface-state wavefunctions which are
localized in all the three directions.


title:
A maximum-entropy approach to the adiabatic freezing of a supercooled
  liquid

abstract:
  I employ the van der Waals theory of Baus and coworkers to analyze the fast,
adiabatic decay of a supercooled liquid in a closed vessel with which the
solidification process usually starts. By imposing a further constraint on
either the system volume or pressure, I use the maximum-entropy method to
quantify the fraction of liquid that is transformed into solid as a function of
undercooling and of the amount of a foreign gas that could possibly be also
present in the test tube. Upon looking at the implications of thermal and
mechanical insulation for the energy cost of forming a solid droplet within the
liquid, I identify one situation where the onset of solidification inevitably
occurs near the wall in contact with the bath.


title:
Polarimetric Properties of Flux-Ropes and Sheared Arcades in Coronal
  Prominence Cavities

abstract:
  The coronal magnetic field is the primary driver of solar dynamic events.
Linear and circular polarization signals of certain infrared coronal emission
lines contain information about the magnetic field, and to access this
information, either a forward or an inversion method must be used. We study
three coronal magnetic configurations that are applicable to polar-crown
filament cavities by doing forward calculations to produce synthetic
polarization data. We analyze these forward data to determine the
distinguishing characteristics of each model. We conclude that it is possible
to distinguish between cylindrical flux ropes, spheromak flux ropes, and
sheared arcades using coronal polarization measurements. If one of these models
is found to be consistent with observational measurements, it will mean
positive identification of the magnetic morphology that surrounds certain
quiescent filaments, which will lead to a greater understanding of how they
form and why they erupt.


title: Diagnosing the Prominence-Cavity Connection

abstract:
  Prominences and cavities are ubiquitously observed together, but the physical
link between these disparate structures has not been established. We address
this issue by using dynamic emission in the extreme ultraviolet (EUV) to probe
the connections of these structures. The SDO/AIA observations show that the
cavity exhibits excessive emission variability compared to the surrounding
quiet-sun streamer, particularly in the 171\AA bandpass. We find that this
dynamic emission takes the form of coherent loop-like brightening structures
which emanate from the prominence into the central cavity. The geometry of
these structures, dubbed prominence horns, generally mimics the curvature of
the cavity boundary. We use a space-time statistical analysis of two cavities
in multiple AIA bandpasses to constrain the energetic properties of 45 horns.
In general, we find there is a positive correlation between the light curves of
the horns in the 171\AA and 193\AA bandpasses, however the 193\AA emission is a
factor of 5 weaker. There is also a strong correlation between structural
changes to the prominence as viewed in the He II 304\AA bandpass and the
enhanced 171\AA emission. In that bandpass, the prominence appears to extend
several megameters along the 171\AA horn where we observe co-spatial,
co-temporal 304\AA and 171\AA emission dynamics. We present these observations
as evidence of the magnetic and energetic connection between the prominence and
the cavity. Further modeling work is necessary to explain the physical source
and consequences of these events, particularly in the context of the
traditional paradigm: the cavity is under dense because it supplies mass to the
over dense prominence.


title:
Properties of BaTiO3/BaZrO3 ferroelectric superlattices with competing
  instabilities

abstract:
  Properties of (BaTiO$_3$)$_1$/(BaZrO$_3$)$_n$ ferroelectric superlattices
(SLs) with $n = {}$1--7 grown in the [001] direction are calculated from first
principles within the density functional theory. It is revealed that the
quasi-two-dimensional ferroelectricity occurs in these SLs in the barium
titanate layers with a thickness of one unit cell; the polarization is oriented
in the layer plane and weakly interacts with the polarization in neighboring
layers. The ferroelectric ordering energy and the height of the barrier
separating different orientational states of polarization in these SLs are
sufficiently large to provide the formation of an array of independent
polarized planes at 300 K. The effect of the structural instability on the
properties of SLs is considered. It is shown that the ground state is a result
of simultaneous condensation of the $\Gamma_{15}$ polar phonon and phonons at
the $M$ point (for SLs with even period) or at the $A$ point (for SLs with odd
period); it is a polar structure with out-of-phase rotations of the octahedra
in neighboring layers, in which highly polarized layers are spatially separated
from the layers with strong rotations. The competition between the
ferroelectric and structural instabilities in biaxially compressed SLs
manifests itself in that the switching on of the octahedra rotations leads to
an abrupt change of the polarization direction and can cause an improper
ferroelectric phase transition to occur. It was shown that the experimentally
observed $z$-component of polarization in the SLs can appear only as a result
of the mechanical stress relaxation.


title: Gravity Asymptotics with Topological Parameters

abstract:
  In four dimensional gravity theory, the Barbero-Immirzi parameter has a
topological origin, and can be identified as the coefficient multiplying the
Nieh-Yan topological density in the gravity Lagrangian, as proposed by Date et
al.[1]. Based on this fact, a first order action formulation for spacetimes
with boundaries is introduced. The bulk Lagrangian, containing the Nieh-Yan
density, needs to be supplemented with suitable boundary terms so that it leads
to a well-defined variational principle. Within this general framework, we
analyse spacetimes with and without a cosmological constant.
  For locally Anti de Sitter (or de Sitter) asymptotia, the action principle
has non-trivial implications. It admits an extremum for all such solutions
provided the SO(3,1) Pontryagin and Euler topological densities are added to it
with fixed coefficients. The resulting Lagrangian, while containing all three
topological densities, has only one independent topological coupling constant,
namely, the Barbero-Immirzi parameter. In the final analysis, it emerges as a
coefficient of the SO(3,2) (or SO(4,1)) Pontryagin density, and is present in
the action only for manifolds for which the corresponding topological index is
non-zero.


title: Photon Emission from a Medium-Modified Shower Evolution

abstract:
  Photons from the interaction of a highly energetic jet with a thermal medium
are an important contribution to the total photon yield measured in
ultrarelativistic heavy-ion collisions and also an important probe to study the
medium degrees of freedom. Previously this contribution has often been computed
in the context of a leading parton energy loss approximation. In this work,
jet-medium interaction photons are instead estimated using a medium-modified
shower evolution model, where the energy degradation due to vacuum radiation
prior to medium formation, the virtuality evolution of intermediate states and
the photon emission from subleading shower partons is taken into account
consistently. The results indicate that the leading parton energy loss
approximation does not appear to work well for photon emission from jet-medium
interaction.


title:
Expectation Values of Local Fields in an Integrable Theory after a
  Quantum Quench

abstract:
  The expectation values of local fields of any interacting quantum theory
after a quench process are key quantities for matching theoretical and
experimental results. For quantum integrable field theories, we argue that they
can be obtained by a generalization of the Leclair-Mussardo formula and a Bethe
Ansatz result of Caux and Konik. Specializing to the Sinh-Gordon model and
taking the non-relativistic limit, one can recover the results of Kormos et al.
for the Lieb-Liniger model.


title: C++11 - okre\'slanie typ\'ow

abstract:
  This paper presents a review of some new futures introduced to C++ language
by ISO/IEC 14882:2011 standard (known as C++11). It describes new language
elements which allow to easier expressed of types of variables: auto and
decltype keywords, new function declaration syntax, and tools which are
included in type_traits header.
  -----
  Niniejszy artyku{\l} jest jednym z serii artyku{\l}\'ow w kt\'orych zawarto
przegl{\ka}d nowych element\'ow j{\ke}zyka C++ wprowadzonych przez standard
ISO/IEC 14882:2011, znany pod nazw{\ka} C++11. W artykule przedstawiono nowe
mo\.zliwo\'sci zwi{\ka}zane ze wskazywaniem typ\'ow zmiennych. Opisano s{\l}owa
kluczowe auto i decltype, now{\ka} sk{\l}adnie deklarowania funkcji/metod oraz
narz{\ke}dzia zawarte w pliku nag{\l}\'owkowym <type_traits>.


title: Uniform tail entropy for real analytic maps

abstract:
  Let $M$ be a compact real analytic manifold of finite dimension. There is a
function $a: (0,+\infty)\to [0,+\infty)$ with $\lim_{t\to0}a(t)=0$ such that,
the tail entropy $h^{*}(f,\varepsilon)$ of any real analytic map $f$ on $M$ is
uniformly bounded above by the scale $a(\varepsilon)$.


title:
Bethe Vectors of Quantum Integrable Models with GL(3) Trigonometric
  $R$-Matrix

abstract:
  We study quantum integrable models with GL(3) trigonometric $R$-matrix and
solvable by the nested algebraic Bethe ansatz. Using the presentation of the
universal Bethe vectors in terms of projections of products of the currents of
the quantum affine algebra $U_q(\hat{\mathfrak{gl}}_3)$ onto intersections of
different types of Borel subalgebras, we prove that the set of the nested Bethe
vectors is closed under the action of the elements of the monodromy matrix.


title: Cylindrical Algebraic Decompositions for Boolean Combinations

abstract:
  This article makes the key observation that when using cylindrical algebraic
decomposition (CAD) to solve a problem with respect to a set of polynomials, it
is not always the signs of those polynomials that are of paramount importance
but rather the truth values of certain quantifier free formulae involving them.
This motivates our definition of a Truth Table Invariant CAD (TTICAD). We
generalise the theory of equational constraints to design an algorithm which
will efficiently construct a TTICAD for a wide class of problems, producing
stronger results than when using equational constraints alone. The algorithm is
implemented fully in Maple and we present promising results from
experimentation.


title: Combining Binary Search Trees

abstract:
  We present a general transformation for combining a constant number of binary
search tree data structures (BSTs) into a single BST whose running time is
within a constant factor of the minimum of any "well-behaved" bound on the
running time of the given BSTs, for any online access sequence.
  (A BST has a well behaved bound with $f(n)$ overhead if it spends at most
\bigoh{f(n)} time per access and its bound satisfies a weak sense of closure
under subsequences.) In particular, we obtain a BST data structure that is
\bigoh{\log\log n} competitive, satisfies the working set bound (and thus
satisfies the static finger bound and the static optimality bound), satisfies
the dynamic finger bound, satisfies the unified bound with an additive
\bigoh{\log\log n} factor, and performs each access in worst-case \bigoh{\log
n} time.


title:
Identifying Participants in the Personal Genome Project by Name (A
  Re-identification Experiment)

abstract:
  We linked names and contact information to publicly available profiles in the
Personal Genome Project. These profiles contain medical and genomic
information, including details about medications, procedures and diseases, and
demographic information, such as date of birth, gender, and postal code. By
linking demographics to public records such as voter lists, and mining for
names hidden in attached documents, we correctly identified 84 to 97 percent of
the profiles for which we provided names. Our ability to learn their names is
based on their demographics, not their DNA, thereby revisiting an old
vulnerability that could be easily thwarted with minimal loss of research
value. So, we propose technical remedies for people to learn about their
demographics to make better decisions.


title: Leptonic commutators and clean T violation in neutrino oscillations

abstract:
  A realistic medium- or long-baseline neutrino experiment may suffer from
terrestrial matter effects which are likely to contaminate the genuine
T-violating asymmetry between \nu_\alpha \to \nu_\beta and \nu_\beta \to
\nu_\alpha oscillations. With the help of the commutators of lepton mass
matrices in matter, we show that this kind of contamination is negligible for a
variety of experiments provided the neutrino beam energy E and the baseline
length L satisfy the condition 10^{-7} (L/km)^2 (GeV/E) << 1. The same
observation is true for the CP-violating term of the asymmetry between
\nu_\alpha \to \nu_\beta and \bar{\nu}_\alpha \to \bar{\nu}_\beta oscillations
in matter.


title:
A Discrete State Transition Algorithm for Generalized Traveling Salesman
  Problem

abstract:
  Generalized traveling salesman problem (GTSP) is an extension of classical
traveling salesman problem (TSP), which is a combinatorial optimization problem
and an NP-hard problem. In this paper, an efficient discrete state transition
algorithm (DSTA) for GTSP is proposed, where a new local search operator named
\textit{K-circle}, directed by neighborhood information in space, has been
introduced to DSTA to shrink search space and strengthen search ability. A
novel robust update mechanism, restore in probability and risk in probability
(Double R-Probability), is used in our work to escape from local minima. The
proposed algorithm is tested on a set of GTSP instances. Compared with other
heuristics, experimental results have demonstrated the effectiveness and strong
adaptability of DSTA and also show that DSTA has better search ability than its
competitors.


title: The equality of the homogeneous and the Gabor wave front set

abstract:
  We prove that H\"ormander's global wave front set and Nakamura's homogeneous
wave front set of a tempered distribution coincide. In addition we construct a
tempered distribution with a given wave front set, and we develop a
pseudodifferential calculus adapted to Nakamura's homogeneous wave front set.


title: Quantum metrology: why entanglement?

abstract:
  We show why and when entanglement is needed for quantum-enhanced precision
measurements, and which type of entanglement is useful. We give a simple,
intuitive construction that shows how entanglement transforms parallel
estimation strategies into sequential ones of same precision. We employ this
argument to generalize conventional quantum metrology, to identify a class of
noise whose effects can be easily managed, and to treat the case of
indistinguishable probes (such as interferometry with light).


title: Pre-Explosive Observational Properties of Type Ia Supernovae

abstract:
  The evolutionary path of rotating CO WDs directly accreting CO-rich matter is
followed up to few seconds before the explosive breakout in the framework of
the Double Degenerate rotationally-driven accretion scenario.
  We find that the evolutionary properties depend only on the actual mass of
the accreting WD and not on the previous history. We determine the expected
frequency and amplitude of the gravitational wave emission, which occurs during
the mass transfer process and acts as a self-tuning mechanism of the accretion
process itself. The gravitational signal related to Galactic sources can be
easily detected with the next generation of space-born interferometers and can
provide notable constraints to the progenitor model. The expected statistical
distribution of pre-explosive objects in the Galaxy is provided also in the
effective temperature-apparent bolometric magnitude diagrams which can be used
to identify merged DD systems via UV surveys.
  We emphasize that the thermonuclear explosion occurs owing to the decay of
physical conditions keeping over-stable the structure above the classical
Chandrasekhar limit and not by a steady increase of the WD mass up to this
limit. This conclusion is independent of the evolutionary scenario for the
progenitors, but it is a direct consequence of the stabilizing effect of
rotation. Such an occurrence is epistemological change of the perspective in
defining the ignition process in accreting WDs. Moreover, this requires a long
evolutionary period (several million years) to attain the explosion after the
above mentioned conditions cease to keep stable the WD. Therefore it is
practically impossible to detect the trace of the exploding WD companion in
recent pre-explosion frames of even very near SN Ia.


title:
Tunable Band Topology Reflected by Fractional Quantum Hall States in
  Two-Dimensional Lattices

abstract:
  Two-dimensional lattice models subjected to an external effective magnetic
field can form nontrivial band topologies characterized by nonzero integer band
Chern numbers. In this Letter, we investigate such a lattice model originating
from the Hofstadter model and demonstrate that the band topology transitions
can be realized by simply introducing tunable longer-range hopping. The rich
phase diagram of band Chern numbers is obtained for the simple rational flux
density and a classification of phases is presented. In the presence of
interactions, the existence of fractional quantum Hall states in both |C|=1 and
|C|>1 bands is confirmed, which can reflect the band topologies in different
phases. In contrast, when our model reduces to a one-dimensional lattice, the
ground states are crucially different from fractional quantum Hall states. Our
results may provide insights into the study of new fractional quantum Hall
states and experimental realizations of various topological phases in optical
lattices.


title: Mind the Resonances: Final stages of accretion into bumpy black holes

abstract:
  In this article we discuss a possible way of testing the Kerr black hole
hypothesis by taking advantage of phenomena correlated with chaotic motion in
the final stages of an accretion disk around a bumpy black hole. We anticipate
that these phenomena should have an imprint in the electromagnetic spectrum
coming from the accretion disk.


title: Information directionality in coupled time series using transcripts

abstract:
  In ordinal symbolic dynamics, transcripts describe the algebraic relationship
between ordinal patterns. Using the concept of transcript, we exploit the
mathematical structure of the group of permutations to derive properties and
relations among information measures of the symbolic representations of time
series. These theoretical results are then applied for the assessment of
coupling directionality in dynamical systems, where suitable coupling
directionality measures are introduced depending only on transcripts. These
novel measures estimate information flow in lower space dimension and reduce to
well-established coupling directionality quantifiers when some general
conditions are satisfied. Furthermore, by generalizing the definition of
transcript to ordinal patterns of different lengths, several of the commonly
used information directionality measures can be encompassed within the same
framework.


title:
Asymptotic Bounds for Quantitative Verification of Perturbed
  Probabilistic Systems

abstract:
  The majority of existing probabilistic model checking case studies are based
on well understood theoretical models and distributions. However, real-life
probabilistic systems usually involve distribution parameters whose values are
obtained by empirical measurements and thus are subject to small perturbations.
In this paper, we consider perturbation analysis of reachability in the
parametric models of these systems (i.e., parametric Markov chains) equipped
with the norm of absolute distance. Our main contribution is a method to
compute the asymptotic bounds in the form of condition numbers for constrained
reachability probabilities against perturbations of the distribution parameters
of the system. The adequacy of the method is demonstrated through experiments
with the Zeroconf protocol and the hopping frog problem.


title: MDMP: Managed Data Message Passing

abstract:
  MDMP is a new parallel programming approach that aims to provide users with
an easy way to add parallelism to programs, optimise the message passing costs
of traditional scientific simulation algorithms, and enable existing MPI-based
parallel programs to be optimised and extended without requiring the whole code
to be re-written from scratch. MDMP utilises a directives based approach to
enable users to specify what communications should take place in the code, and
then implements those communications for the user in an optimal manner using
both the information provided by the user and data collected from instrumenting
the code and gathering information on the data to be communicated. This work
will present the basic concepts and functionality of MDMP and discuss the
performance that can be achieved using our prototype implementation of MDMP on
some model scientific simulation applications.


title: Equivalence of Two Approaches to Yang-Mills on Non-commutative Torus

abstract:
  There are two notions of Yang-Mills action functional in noncommutative
geometry. We show that for noncommutative n-torus both these notions agree. We
also prove a structure theorem on the Hermitian structure of a finitely
generated projective modules over spectrally invariant subalgebras of
$C^*$-algebras.


title: Yang- Mills on Quantum Heisenberg Manifolds

abstract:
  In the noncommutative geometry program of Connes there are two variations of
the concept of Yang-Mills action functional. We show that for the quantum
Heisenberg manifolds they agree.


title: On the size of linear superpositions in molecular nanomagnets

abstract:
  Molecular nanomagnets are zero-dimensional spin systems, that exhibit quantum
mechanical behavior at low temperatures. Exploiting quantum-information
theoretic measures, we quantify here the size of linear superpositions that can
be generated within the ground multiplet of high- and low-spin nanomagnets.
Amongst the former class of systems, we mainly focus on Mn12 and Fe8. General
criteria for further increasing such sizes are also outlined, and illustrated
in the case of spin rings. The actual character (micro or macroscopic) of
linear superpositions in low-spin systems is inherently ill-defined. Here, this
issue is addressed with specific reference to the Cr7Ni and V15 molecules,
characterized by an S=1/2 ground state. In both cases, the measures we obtain
are larger than those of a single s=1/2 spin, but not proportionate to the
number and value of the constituent spins.


title:
Going beyond the double well: complex mode dynamics of effective coupled
  oscillators in infinite dimensional systems

abstract:
  In this work we explore how nonlinear modes described by a dispersive wave
equation (in our example, the nonlinear Schrodinger equation) and localized in
a few wells of a periodic potential can act analogously to a chain of coupled
mechanical oscillators. We identify the small-amplitude oscillation modes of
these `coupled wave oscillators' and find that they can be extended into the
large amplitude regime, where some can `ring' for long times. We also identify
prototypical case examples of more complex dynamical behaviour that can arise
in such systems beyond the double well paradigm, including the breakdown of
Josephson-like oscillations and of internal modes more generally, the transfer
of energy out of/destabilization of fundamental oscillation modes and the
emergence of chaotic oscillations for large amplitude excitations. We provide
details of the phase perturbations required for experimental observations of
such dynamics, and show that the oscillator formalism can be extended to
predict large amplitude excitations in genuinely two-dimensional
configurations.


title:
On Evolutionary Equations with Material Laws Containing Fractional
  Integrals

abstract:
  A well-posedness result for a time-shift invariant class of evolutionary
operator equations involving material laws with fractional time-integrals of
order $\alpha\in]0,1[$ is considered and exemplified by an application to a
Kelvin-Voigt type model.


title:
Zeros of densities and decomposition problem for multidimensional entire
  characteristic functions of order 2

abstract:
  We consider the entire characteristic functions of order 2 and we prove some
decomposition theorems in a multidimensional case. We show that the lack of
zeros of the density function is a necessary but not a sufficient (as in the
one-dimensional case) condition for a characteristic function to be
decomposable. We also find some simple sufficient conditions.


title:
Optimal Design of Water Distribution Networks by Discrete State
  Transition Algorithm

abstract:
  Optimal design of water distribution networks, which are governed by a series
of linear and nonlinear equations, has been extensively studied in the past
decades. Due to their NP-hardness, methods to solve the optimization problem
have changed from traditional mathematical programming to modern intelligent
optimization techniques. In this study, with respect to the model formulation,
we have demonstrated that the network system can be reduced to the
dimensionality of the number of closed simple loops or required independent
paths, and the reduced nonlinear system can be solved efficiently by the
Newton-Raphson method. Regarding the optimization technique, a discrete state
transition algorithm (STA) is introduced to solve several cases of water
distribution networks. In discrete STA, there exist four basic intelligent
operators, namely, swap, shift, symmetry and substitute as well as the "risk
and restore in probability" strategy. Firstly, we focus on a parametric study
of the restore probability $p_1$ and risk probability $p_2$. To effectively
deal with the head pressure constraints, we then investigate the effect of
penalty coefficient and search enforcement on the performance of the algorithm.
Based on the experience gained from the training of the Two-Loop network
problem, the discrete STA has successfully achieved the best known solutions
for the Hanoi and New York problems. A detailed comparison of our results with
those gained by other algorithms is also presented.


title: Contextuality and probability representation of quantum states

abstract:
  The contextuality and noncontextuality notions are considered in framework of
probability representation of quantum states. Example of qutrit states and
violation of the noncontextuality inequalities are presented by using the spin
tomogram and tomographic symbols of the observables.


title:
Approximation faible et principe de Hasse pour des espaces homog\`enes
  \`a stabilisateur fini r\'esoluble (Weak Approximation and Hasse Principle
  for homogeneous spaces with finite solvable stabilizer)

abstract:
  Soit $K$ un corps global et $G$ un $K$-groupe fini r\'esoluble. Sous
certaines hypoth\`eses sur une extension d\'eployant $G$, on d\'emontre que
l'espace homog\`ene $V:=G'/G$ avec $G'$ un $K$-groupe semi-simple simplement
connexe v\'erifie l'approximation faible. On utilise une version plus pr\'ecise
de ce r\'esultat pour d\'emontrer le principe de Hasse pour des espaces
homog\`enes $X$ sous un $K$-groupe $G'$ semi-simple simplement connexe \`a
stabilisateur g\'eom\'etrique $\bar G$ fini et r\'esoluble, sous certaines
hypoth\`eses sur le $K$-lien $(\bar G,\kappa)$ d\'efini par $X$.
  -----
  Let $K$ be a global field and $G$ a finite solvable $K$-group. Under certain
hypotheses concerning the extension splitting $G$, we show that the homogeneous
space $V=G'/G$ with $G'$ a semi-simple simply connected $K$-group has weak
approximation. We use a more precise version of this result to prove the Hasse
principle for homogeneous spaces $X$ under a semi-simple simply connected
$K$-group $G'$ with finite solvable geometric stabilizer $\bar G$, under
certain hypotheses concerning the $K$-kernel (or $K$-lien) $(\bar G,\kappa)$
defined by $X$.


title: Renewal theory for random walks on surface groups

abstract:
  We construct a renewal structure for random walks on surface groups. The
renewal times are defined as times when the random walks enters a particular
type of a cone and never leaves it again. As a consequence, the trajectory of
the random walk can be expressed as an "aligned union" of i.i.d. trajectories
between the renewal times. Once having established this renewal structure, we
prove a central limit theorem for the distance to the origin under exponential
moment conditions. Analyticity of the speed and of the asymptotic variance are
natural consequences of our approach. Furthermore, our method applies to groups
with infinitely many ends and therefore generalizes classic results on central
limit theorems on free groups.


title:
Stability of a Random Multiple Access Channel with "Success-Failure"
  Feedback

abstract:
  We consider a model of a decentralized multiple access system with a
non-standard binary feedback where the empty and collision situations cannot be
distinguished. We show that, like in the case of a ternary feedback, for any
input rate \lambda < 1/e, there exists a "doubly randomized" adaptive
transmission protocol which stabilizes the behavior of the system. We discuss
also a number of related problems and formulate some hypotheses.


title: Amplitudes and Cross Sections at the LHC

abstract:
  We describe the elements of the GLM model that successfully describes soft
hadronic interactions at energies from ISR to LHC. This model is based on a
single Pomeron with a large intercept $\Delta_{\pom}$ = 0.23 and slope
$\alpha_{\pom}'$ = 0, and so provides a natural matching with perturbative QCD.
We analyze the elastic, single diffractive and double diffractive amplitudes,
and compare the behaviour of the GLM amplitudes to those of other
parameterizations.
  We summarize the main features and results of competing models for soft
interactions at LHC energies.


title: On 2D NLS on non-trapping exterior domains

abstract:
  Global existence and scattering for the nonlinear defocusing Schr\"odinger
equation in 2 dimensions are known for domains exterior to star-shaped
obstacles and for nonlinearities that grow at least as the quintic power. In
this paper, we extend the global existence result for all non-trapping
obstacles and for nonlinearities with power strictly greater than quartic. For
such nonlinearities, we also prove scattering for a class of so-called almost
star-shaped obstacles.


title: Unidentified Infrared Emission bands: PAHs or MAONs?

abstract:
  We suggest that the carrier of the unidentified infrared emission (UIE) bands
is an amorphous carbonaceous solid with mixed aromatic/aliphatic structures,
rather than free-flying polycyclic aromatic hydrocarbon (PAH) molecules.
Through spectral fittings of the astronomical spectra of the UIE bands, we show
that a significant amount of the energy is emitted by the aliphatic component,
implying that aliphatic groups are an essential part of the chemical structure.
Arguments in favor of an amorphous, solid-state structure rather than a
gas-phase molecule as a carrier of the UIE are also presented.


title: Predictive description of Planck-scale-induced spacetime fuzziness

abstract:
  Several approaches to the quantum-gravity problem predict that spacetime
should be "fuzzy", but have been so far unable to provide a crisp physical
characterization of this notion. An intuitive picture of spacetime fuzziness
has been proposed on the basis of semi-heuristic arguments, and in particular
involves an irreducible Planck-scale contribution to the uncertainty of the
energy of a particle. These arguments also inspired a rather active
phenomenological programme looking for blurring of images of distant
astrophysical sources that would result from such energy uncertainties. We here
report the first ever physical characterization of spacetime fuzziness derived
constructively within a quantum picture of spacetime, the one provided by
spacetime noncommutativity. Our results confirm earlier heuristic arguments
suggesting that spacetime fuzziness, while irrelevantly small on terrestrial
scales, could be observably large for propagation of particles over
cosmological distances. However, we find no Planck-scale-induced lower bound on
the uncertainty of the energy of particles, and we observe that this changes
how we should picture a quantum spacetime and also imposes a reanalysis of the
associated phenomenology.


title:
Composite-particles (Boson, Fermion) Theory of Fractional Quantum Hall
  Effect

abstract:
  A quantum statistical theory is developed for a fractional quantum Hall
effects in terms of composite bosons (fermions) each of which contains a
conduction electron and an odd (even) number of fluxons. The cause of the QHE
is by assumption the phonon exchange attraction between the conduction electron
("electron", "hole") and fluxons (quanta of magnetic fluxes). We postulate that
c-fermions with \emph{any} even number of fluxons have an effective charge
(magnitude) equal to the electron charge $e$. The density of c-fermions with
$m$ fluxons, $n_\phi^{(m)}$, is connected with the electron density $n_{\mathrm
e}$ by $n_\phi^{(m)}=n_{\mathrm e}/m$, which implies a more difficult formation
for higher $m$, generating correct values $me^2/h$ for the Hall conductivity
$\sigma_{\mathrm H}\equiv j/E_{\mathrm H}$. For condensed c-bosons the density
of c-bosons-with-$m$ fluxons, $n_\phi^{(m)}$, is connected with the boson
density $n_0$ by $n_\phi^{(m)}=n_0/m$. This yields $\sigma_{\mathrm
H}=m\,e^2/h$ for the magnetoconductivity, the value observed of the QHE at
filling factor $\nu=1/m$ ($m=$odd numbers). Laughlin's theory and results about
the fractional charge are not borrowed in the present work.


title: Counting small cuts in a graph

abstract:
  We study the minimum cut problem in the presence of uncertainty and show how
to apply a novel robust optimization approach, which aims to exploit the
similarity in subsequent graph measurements or similar graph instances, without
posing any assumptions on the way they have been obtained. With experiments we
show that the approach works well when compared to other approaches that are
also oblivious towards the relationship between the input datasets.


title:
Molecular dynamics studies on the NMR and X-ray structures of rabbit
  prion protein wild-type and mutants

abstract:
  Prion diseases are invariably fatal and highly infectious neurodegenerative
diseases that affect a wide variety of mammalian species such as sheep, goats,
mice, humans, chimpanzees, hamsters, cattle, elks, deer, minks, cats, chicken,
pigs, turtles, etc. These neurodegenerative diseases are caused by the
conversion from a soluble normal cellular protein into insoluble abnormally
folded infectious prions and the conversion is believed to involve
conformational change from a predominantly alpha-helical protein to one rich in
beta-sheet structure. Such conformational changes may be amenable to study by
molecular dynamics (MD) techniques. For rabbits, classical studies show they
have a low susceptibility to be infected, but in 2012 it was reported that
rabbit prion can be generated (though not directly) and the rabbit prion is
infectious and transmissible (Proceedings of the National Academy of Sciences
USA 109(13): 5080-5). This paper studies the NMR and X-ray molecular structures
of rabbit prion protein wild-type and mutants by MD techniques, in order to
understand the specific mechanism of rabbit prion protein and rabbit prions.


title: Spectroscopy with glueballs and the role of f_0(1370)

abstract:
  The existence of glueballs, bound states of gluons, is one of the basic
predictions of QCD; the lightest state is expected to be a scalar. The
experimental situation, however, is still ambiguous. The existence of f_0(1370)
would point to a supernumerous state within the nonet classification of scalars
and would therefore provide a hint towards a glueball. In this talk we
summarize some arguments in favour and against the existence of f_0(1370) and
discuss schemes with and without this state included.


title:
The 2011 October Draconids outburst. I. Orbital elements, meteoroid
  fluxes and 21P/Giacobini-Zinner delivered mass to Earth

abstract:
  On October 8th, 2011 the Earth crossed the dust trails left by comet
21P/Giacobini-Zinner during its XIX and XX century perihelion approaches with
the comet being close to perihelion. The geometric circumstances of that
encounter were thus favorable to produce a meteor storm, but the trails were
much older than in the 1933 and 1946 historical encounters. As a consequence
the 2011 October Draconid display exhibited several activity peaks with
Zenithal Hourly Rates of about 400 meteors per hour. In fact, if the display
had been not forecasted, it could have passed almost unnoticed as was strongly
attenuated for visual observers due to the Moon. This suggests that most meteor
storms of a similar nature could have passed historically unnoticed under
unfavorable weather and Moon observing conditions. The possibility of obtaining
information on the physical properties of cometary meteoroids penetrating the
atmosphere under low-geocentric velocity encounter circumstances motivated us
to set up a special observing campaign. Added to the Spanish Fireball Network
wide-field all-sky and CCD video monitoring, other high-sensitivity 1/2" black
and white CCD video cameras were attached to modified medium-field lenses for
obtaining high resolution orbital information. The trajectory, radiant, and
orbital data of 16 October Draconid meteors observed at multiple stations are
presented. The results show that the meteors appeared from a geocentric radiant
located at R.A.=263.0+-0.4 deg. and Dec.=+55.3+-0.3 deg. that is in close
agreement with the radiant predicted for the 1873-1894 and the 1900 dust
trails. The estimated mass of material from 21P/Giacobini-Zinner delivered to
Earth during the six-hours outburst was around 950+-150 kg.


title:
Bose glass transition and spin-wave localization for 2D bosons in a
  random potential

abstract:
  A spin-wave approach of the zero temperature superfluid-insulator transition
for two-dimensional hard-core bosons in a random potential $\mu=\pm$ W is
developed. While at the classical level there is no intervening phase between
the Bose-condensed superfluid (SF) and the gapped disordered insulator, the
introduction of quantum fluctuations leads to a much richer physics. Upon
increasing the disorder strength W, the Bose-condensed fraction disappears
first, before the SF. Then a gapless Bose-glass phase emerges over a finite
region until the insulator appears. Furthermore, in the strongly disordered SF
regime, a mobility edge in the spin-wave excitation spectrum is found at a
finite frequency $\Omega_c$ decreasing with W, and presumably vanishing in the
Bose-glass phase.

categories: cond-mat.str-el cond-mat.dis-nn cond-mat.quant-gas cond-mat.supr-con


title: Markov tail chains

abstract:
  The extremes of a univariate Markov chain with regulary varying stationary
marginal distribution and asymptotically linear behavior are known to exhibit a
multiplicative random walk structure called the tail chain. In this paper, we
extend this fact to Markov chains with multivariate regularly varying marginal
distribution in R^d. We analyze both the forward and the backward tail process
and show that they mutually determine each other through a kind of adjoint
relation. In a broader setting, it will be seen that even for non-Markovian
underlying processes a Markovian forward tail chain always implies that the
backward tail chain is Markovian as well. We analyze the resulting class of
limiting processes in detail. Applications of the theory yield the asymptotic
distribution of both the past and the future of univariate and multivariate
stochastic difference equations conditioned on an extreme event.


title: Lobby index as a network centrality measure

abstract:
  We study the lobby index (l-index for short) as a local node centrality
measure for complex networks. The l-inde is compared with degree (a local
measure), betweenness and Eigenvector centralities (two global measures) in the
case of biological network (Yeast interaction protein-protein network) and a
linguistic network (Moby Thesaurus II). In both networks, the l-index has poor
correlation with betweenness but correlates with degree and Eigenvector. Being
a local measure, one can take advantage by using the l-index because it carries
more information about its neighbors when compared with degree centrality,
indeed it requires less time to compute when compared with Eigenvector
centrality. Results suggests that l-index produces better results than degree
and Eigenvector measures for ranking purposes, becoming suitable as a tool to
perform this task.


title: Multiple $\mathbb{S}^{1}$-orbits for the Schr\"odinger-Newton system

abstract:
  We prove existence and multiplicity of symmetric solutions for the
\emph{Schr\"odinger-Newton system} in three dimensional space using equivariant
Morse theory.


title: Thermodynamic equilibrium conditions of graphene films on SiC

abstract:
  First-principles surface phase diagrams reveal that epitaxial monolayer
graphene films on the Si side of 3C-SiC(111) can exist as thermodynamically
stable phases in a narrow range of experimentally controllable conditions,
defining a path to the highest-quality graphene films. Our calculations are
based on a van der Waals corrected density functional. The full, experimentally
observed (6 sqrt(3)x 6 sqrt(3))-R30 supercells for zero- to trilayer graphene
are essential to describe the correct interface geometries and the relative
stability of surface phases and possible defects.


title:
Numerical results for the Edwards-Anderson spin-glass model at low
  temperature

abstract:
  We have simulated Edwards-Anderson (EA) as well as Sherrington-Kirkpatrick
systems of L^3 spins. After averaging over large sets of EA system samples of 3
=< L =< 10, we obtain accurate numbers for distributions p(q) of the overlap
parameter q at very low temperature T. We find p(0)/T --> 0.233(4) as T --> 0.
This is in contrast with the droplet scenario of spin glasses. We also study
the number of mismatched links --between replica pairs-- that come with large
scale excitations. Contributions from small scale excitations are discarded. We
thus obtain for the fractal dimension of outer surfaces of q~0 excitations in
the EA model d_s --> 2.59(3) as T tends to 0. This is in contrast with d_s -->
3 as T --> 0 that is predicted by mean field theory for the macroscopic limit.


title: Ranking and Tradeoffs in Sponsored Search Auctions

abstract:
  In a sponsored search auction, decisions about how to rank ads impose
tradeoffs between objectives such as revenue and welfare. In this paper, we
examine how these tradeoffs should be made. We begin by arguing that the most
natural solution concept to evaluate these tradeoffs is the lowest symmetric
Nash equilibrium (SNE). As part of this argument, we generalise the well known
connection between the lowest SNE and the VCG outcome. We then propose a new
ranking algorithm, loosely based on the revenue-optimal auction, that uses a
reserve price to order the ads (not just to filter them) and give conditions
under which it raises more revenue than simply applying that reserve price.
Finally, we conduct extensive simulations examining the tradeoffs enabled by
different ranking algorithms and show that our proposed algorithm enables
superior operating points by a variety of metrics.


title: Galois theory for H-extensions

abstract:
  We show that there exists a Galois correspondence between subalgebras of an
H-comodule algebra A over a base ring R and generalised quotients of a Hopf
algebra H if both A and H are flat Mittag--Leffler modules. We also provide new
criteria for subalgebras and generalised quotients to be closed elements of the
Galois connection constructed. We generalise the Schauenburg theory of
admissible objects to this more general context. Then we consider coextensions
of H-module coalgebras. We construct a Galois connection for them and we prove
that H-Galois coextensions are closed. We apply the results obtained to the
Hopf algebra itself and we give a simple proof that there is a bijective
correspondence between right ideal coideals of H and its left coideal
subalgebras when H is finite dimensional. Furthermore, we formulate a necessary
and sufficient condition for a bijective Galois correspondence for A=H. We also
consider crossed product algebras.


title:
A nonextensive approach to the stellar rotational evolution I. F and G
  type stars

abstract:
  The pioneering study by Skumanich (1972) showed that the rotational velocity
of G-type Main-Sequence (MS) stars decreases with stellar age according to $<v
\sin i>$ $\propto$ $t^{-1/2}$. This relationship is consistent with simple
theories of angular momentum loss from rotating stars, where an ionized wind is
coupled to the star by a magnetic field. The present study introduces a new
approach to the study of stellar rotational braking in unsaturated F and G type
stars limited in age and mass, connecting angular momentum loss by magnetic
stellar wind with Tsallis nonextensive statistical mechanics. As a result, we
show that the rotation-age relationship can be well reproduced using a
nonextensive approach from Tsallis nonextensive models. Here, the index $q$,
which is related to the degree of nonextensivity, can be associated to the
dynamo process and to magnetic field geometry, offering relevant information on
the level of stellar magnetic braking for F- and G-type Main-Sequence stars.


title:
Test of two new parameterizations of the Generalized Parton Distribution
  $H$

abstract:
  In 2011 Radyushkin outlined the practical implementation of the One-Component
Double Distribution formalism in realistic Generalized Parton Distribution
models. We compare the One-Component Double Distribution framework to the
standard one and compute Deeply Virtual Compton Scattering observables for
both. In particular the new implementation is more flexible, offering a greater
range of variation of the real and imaginary parts of the associated Compton
Form Factor while still allowing to recover results similar to the classical
approach. Moreover the polynomiality property is satisfied up to the highest
order. Although the comparison to experimental data may be improved, the
One-Component Double Distribution modeling is thus an attractive alternative.


title: Nonextensive triplet in geological faults system

abstract:
  The San Andreas fault (SAF) in the USA is one of the most investigated
self-organizing systems in nature. In this paper, we studied some geophysical
properties of the SAF system in order to analyze the behavior of earthquakes in
the context of Tsallis's $q$--Triplet. To that end, we considered 134,573
earthquake events in magnitude interval $2\leq m<8$, taken from the Southern
Earthquake Data Center (SCEDC, 1932 - 2012). The values obtained
("$q$--Triplet"$\equiv$$\{$$q$$_{stat}$,$q$$_{sen}$,$q$$_{rel}$$\}$) reveal
that the $q_{stat}$--Gaussian behavior of the aforementioned data exhibit
long-range temporal correlations. Moreover, $q_{sen}$ exhibits
quasi-monofractal behavior with a Hurst exponent of 0.87.


title:
Parity: from strong CP problem to dark matter, neutrino masses and
  baryon asymmetry

abstract:
  We show that in an SU(3)_c\times [SU(2)_L\times U(1)_Y]\times [SU(2)'_R\times
U(1)'_Y] framework, the parity symmetry motivated by solving the strong CP
problem without resorting to an axion can predict a dark matter particle with a
mass around 302 GeV. This dark matter candidate can be directly detected in the
presence of a U(1)_Y\times U(1)'_Y kinetic mixing. Furthermore, our model can
accommodate a natural way to simultaneously realize an inverse-linear seesaw
for neutrino masses and a resonant leptogenesis for baryon asymmetry.


title:
Separating the bulk and surface n- to p-type transition in the
  topological insulator GeBi(4-x)SbxTe7

abstract:
  We identify the multi-layered compound GeBi4Te7 to be a topological insulator
with a freestanding Dirac point, slightly above the valence band maximum, using
angle-resolved photoemission spectroscopy (ARPES) measurements. The spin
polarization satisffies the time reversal symmetry of the surface states,
visible in spin-resolved ARPES. For increasing Sb content in GeBi(4-x)SbxTe7 we
observe a transition from n- to p-type in bulk sensitive Seebeck coefficient
measurements at a doping of x = 0.6. In surface sensitive ARPES measurements a
rigid band shift is observed with Sb doping, accompanied by a movement of the
Dirac point towards the Fermi level. Between x = 0.8 and x = 1 the Fermi level
crosses the band gap, changing the surface transport regime. This difference of
the n- to p-type transition between the surface region and the bulk is caused
by band bending effects which are also responsible for a non-coexistence of
insulating phases in the bulk and in the near surface region.


title:
Serre weights for locally reducible two-dimensional Galois
  representations

abstract:
  Let F be a totally real field, and v a place of F dividing an odd prime p. We
study the weight part of Serre's conjecture for continuous, totally odd,
two-dimensional mod p representations rhobar of the absolute Galois group of F
that are reducible locally at v. Let W be the set of predicted Serre weights
for the semisimplification of rhobar restricted to the decomposition group at
v. We prove that when the local representation is generic, the Serre weights in
W for which rhobar is modular are exactly the ones that are predicted (assuming
that rhobar is modular). We also determine precisely which subsets of W arise
as predicted weights when the local representation varies with fixed generic
semisimplification.


title:
The 2011 October Draconids Outburst. II. Meteoroid Chemical Abundances
  from Fireball Spectroscopy

abstract:
  On October 8, 2011 the Earth crossed dust trails ejected from comet
21P/Giacobini-Zinner in the late 19th and early 20th Century. This gave rise to
an outburst in the activity of the October Draconid meteor shower, and an
international team was organized to analyze this event. The SPanish Meteor
Network (SPMN) joined this initiative and recorded the October Draconids by
means of low light level CCD cameras. In addition, spectroscopic observations
were carried out. Tens of multi-station meteor trails were recorded, including
an extraordinarily bright October Draconid fireball (absolute mag. -10.5) that
was simultaneously imaged from three SPMN meteor ob-serving stations located in
Andalusia. Its spectrum was obtained, showing a clear evolution in the relative
intensity of emission lines as the fireball penetrated deeper into the
atmosphere. Here we focus on the analysis of this remarkable spectrum, but also
discuss the atmospheric trajectory, atmospheric penetration, and orbital data
computed for this bolide which was probably released during
21P/Giacobini-Zinner return to perihelion in 1907. The spectrum is discussed
together with the tensile strength for the October Draconid meteoroids. The
chemical profile evolution of the main rocky elements for this extremely bright
bolide is compared with the elemental abundances obtained for 5 October
Draconid fireballs also recorded during our spectroscopic campaign but observed
only at a single station. Significant chemical heterogeneity between the small
meteoroids is found as we should expect for cometary aggregates being formed by
diverse dust components.


title: On asymptotically hereditarily aspherical groups

abstract:
  We undertake a systematic study of asymptotically hereditarily aspherical
(AHA) groups - the class of groups introduced by Tadeusz Januszkiewicz and the
second author as a tool for exhibiting exotic properties of systolic groups. We
provide many new examples of AHA groups, also in high dimensions. We relate AHA
property with the topology at infinity of a group, and deduce in this way some
new properties of (weakly) systolic groups. We also exhibit an interesting
property of boundary at infinity for few classes of AHA groups.


title: Axion cooling of white dwarfs

abstract:
  The evolution of white dwarfs is a simple gravothermal process. This process
can be tested in two ways, through the luminosity function of these stars and
through the secular variation of the period of pulsation of those stars that
are variable. Here we show how the mass of the axion can be constrained using
the white dwarf luminosity function.


title:
Usage History of Scientific Literature: Nature Metrics and Metrics of
  Nature Publications

abstract:
  In this study, we analyze the dynamic usage history of Nature publications
over time using Nature metrics data. We conduct analysis from two perspectives.
On the one hand, we examine how long it takes before the articles' downloads
reach 50%/80% of the total; on the other hand, we compare the percentage of
total downloads in 7 days, 30 days, and 100 days after publication. In general,
papers are downloaded most frequently within a short time period right after
their publication. And we find that compared with Non-Open Access papers,
readers' attention on Open Access publications are more enduring. Based on the
usage data of a newly published paper, regression analysis could predict the
future expected total usage counts.


title:
Optimised hybrid parallelisation of a CFD code on Many Core
  architectures

abstract:
  COSA is a novel CFD system based on the compressible Navier-Stokes model for
unsteady aerodynamics and aeroelasticity of fixed structures, rotary wings and
turbomachinery blades. It includes a steady, time domain, and harmonic balance
flow solver.
  COSA has primarily been parallelised using MPI, but there is also a hybrid
parallelisation that adds OpenMP functionality to the MPI parallelisation to
enable larger number of cores to be utilised for a given simulation as the MPI
parallelisation is limited to the number of geometric partitions (or blocks) in
the simulation, or to exploit multi-threaded hardware where appropriate. This
paper outlines the work undertaken to optimise these two parallelisation
strategies, improving the efficiency of both and therefore reducing the
computational time required to compute simulations. We also analyse the power
consumption of the code on a range of leading HPC systems to further understand
the performance of the code.


title: Isometric Surfaces and the Third Laplace-Beltrami

abstract:
  In this paper, classical isometric helicoidal and rotational surfaces are
studied, and generalized by Bour's theorem in three dimensional Euclidean
space. Moreover, the third Laplace-Beltrami operators of two classical surfaces
are obtained.


title: The Influence of Global Self-Heating on the Yarkovsky and YORP Effects

abstract:
  We present an adaptation of the ATPM to simultaneously predict the Yarkovsky
and YORP effects in the presence of global self-heating that occurs within the
large concavities of irregularly shaped asteroids, which has been neglected or
dismissed in all previous models. It is also combined with rough surface
thermal-infrared beaming effects, which have been previously shown to enhance
the Yarkovsky-orbital-drift and dampen on average the
YORP-rotational-acceleration by orders of several tens of per cent. Tests on
all published concave shape models of near-Earth asteroids, and also on one
hundred Gaussian-random-spheres, show that the Yarkovsky effect is sensitive to
shadowing and global self-heating effects at the few per cent level or less.
For simplicity, Yarkovsky models can neglect these effects if the level of
accuracy desired is of this order. Unlike the Yarkovsky effect, the YORP effect
can be very sensitive to shadowing and global self-heating effects. Its
sensitivity increases with decreasing relative strength of the
YORP-rotational-acceleration, and doesn't appear to depend greatly on the
degree of asteroid concavity. Global self-heating tends to produce a vertical
offset in an asteroid's YORP-rotational-acceleration versus obliquity curve
which is in opposite direction to that produced by shadowing effects. It also
ensures that at least one critical obliquity angle exists at which zero
YORP-rotational-acceleration occurs. Global self-heating must be included for
accurate predictions of the YORP effect if an asteroid exhibits a large
shadowing effect. If global self-heating effects are not included then it is
found in ~75 per cent of cases that better predictions are produced when
shadowing is also not included. Furthermore, global self-heating has
implications for reducing the sensitivity of the YORP effect predictions to
detailed variations in an asteroid's shape model.


title:
(T,L)-type rotational surface in three dimensional Lorentz-Minkowski
  space

abstract:
  We study the third Laplace-Beltrami operator of timelike rotational surface
of (T,L)-type in three dimensional Lorentz-Minkowski space.


title:
Cumulative physical uncertainty in modern stellar models. II. The
  dependence on the chemical composition

abstract:
  We extend our work on the effects of the uncertainties on the main input
physics for the evolution of low-mass stars. We analyse the dependence of the
cumulative physical uncertainty affecting stellar tracks on the chemical
composition. We calculated more than 6000 stellar tracks and isochrones, with
metallicity ranging from Z = 0.0001 to 0.02, by changing the following physical
inputs within their current range of uncertainty: 1H(p,nu e+)2H,
14N(p,gamma)15O and triple-alpha reaction rates, radiative and conductive
opacities, neutrino energy losses, and microscopic diffusion velocities. The
analysis was performed using a latin hypercube sampling design. We examine in a
statistical way the dependence on the variation of the physical inputs of the
turn-off (TO) luminosity, the central hydrogen exhaustion time (t_H), the
luminosity and the helium core mass at the red-giant branch (RGB) tip, and the
zero age horizontal branch (ZAHB) luminosity in the RR Lyrae region. For the
stellar tracks, an increase from Z = 0.0001 to Z = 0.02 produces a cumulative
physical uncertainty in TO luminosity from 0.028 dex to 0.017 dex, while the
global uncertainty on t_H increases from 0.42 Gyr to 1.08 Gyr. For the RGB tip,
the cumulative uncertainty on the luminosity is almost constant at 0.03 dex,
whereas the one the helium core mass decreases from 0.0055 M_sun to 0.0035
M_sun. The dependence of the ZAHB luminosity error is not monotonic with Z, and
it varies from a minimum of 0.036 dex at Z = 0.0005 to a maximum of 0.047 dex
at Z = 0.0001. Regarding stellar isochrones of 12 Gyr, the cumulative physical
uncertainty on the predicted TO luminosity and mass increases respectively from
0.012 dex to 0.014 dex and from 0.0136 M_sun to 0.0186 M_sun. Consequently, for
ages typical of galactic globular clusters, the uncertainty on the age inferred
from the TO luminosity increases from 325 Myr to 415 Myr.


title: On the Coble quartic and Fourier-Jacobi expansion of theta relations

abstract:
  In the paper "The universal Kummer threefold", Q. Ren, S. Sam, G. Schrader,
and B. Sturmfels (arXiv:1208.1229), conjectured equations for the universal
Kummer variety in genus 3 case. Though, most of these equations are obtained
from the Fourier-Jacobi expansion of relations among theta constants in genus
4, the more prominent one, Coble's quartic was obtained differently. The aim of
the current paper is to show that Coble's quartic can be obtained as
Fourier-Jacobi expansion of a relation among theta-constants in genus 4. We get
also one more relation that could be in the ideal described in "The universal
Kummer threefold".


title: Supersymmetric Wilson loops with general contours in ABJM theory

abstract:
  We consider general supersymmetric Wilson loops in ABJM model, i.e.
Chern-Simons-matter theory in 2+1 dimensions with N=6 supersymmetry. They are
so-called Zarembo-type: the Wilson loops of our interest have generic contours
in spacetime, but the scalar field coupling is arranged accordingly so that
there are unbroken supersymmetries. Based on the supermatrix formulation of
Wilson loops by Drukker and Trancanelli, we construct explicitly 1/6-BPS Wilson
loops and check that their expectation value is protected using perturbation up
to two loops. We also study the dual string configuration in AdS4 x CP3
background and check the supersymmetry.


title: Bilayer Graphene Quantum Dot Defined by Topgates

abstract:
  We investigate the application of nanoscale topgates on exfoliated bilayer
graphene to define quantum dot devices. At temperatures below 500 mK the
conductance underneath the grounded gates is suppressed, which we attribute to
nearest neighbour hopping and strain-induced piezoelectric fields. The
gate-layout can thus be used to define resistive regions by tuning into the
corresponding temperature range. We use this method to define a quantum dot
structure in bilayer graphene showing Coulomb blockade oscillations consistent
with the gate layout.


title:
On the LAMN property for continuous observations of some diffusion
  processes with jumps

abstract:
  In this paper, we consider a diffusion process with jumps whose drift and
jump coefficient depend on an unknown parameter. We then give a self-contained
proof of the local asymptotic mixed normality (LAMN) property when the process
is observed continuously in a time interval $[0; T]$ as $T\to\infty$, and
derive, as a consequence, the local asymptotic normality (LAN) property in the
ergodic case. For this, we give a proof of a Girsanov's theorem and a Central
Limit theorem for a pure jump martingale. Our results could be viewed as a
consequence of the LAMN property for semimartingales proved by Luschgy [15],
using the Girsanov's theorem for semimartingales obtained in Jacod and Shiryaev
[9], and the Central Limit theorem for semimartingales established by
S{\o}rensen [21] and Feigin [3]. The aim of this paper is to present a proof of
these results without using this abstract semimartingale theory but integral
equations with respect to Poisson random measures.


title: Picard-Vessiot theory of differentially simple rings

abstract:
  In Picard-Vessiot theory, the Galois theory for linear differential
equations, the Picard-Vessiot ring plays an important role, since it is the
Picard-Vessiot ring which is a torsor (principal homogeneous space) for the
Galois group (scheme). Like fields are simple rings having only (0) and (1) as
ideals, the Picard-Vessiot ring is a differentially simple ring, i.e. a
differential ring having only (0) and (1) as differential ideals. Having in
mind that the classical Galois theory is a theory of extensions of fields, i.e.
of simple rings, it is quite natural to ask whether one can also set up a
Picard-Vessiot theory where the base is not a differential field, but more
general a differentially simple ring. It is the aim of this article to give a
positive answer to this question, i.e. to set up such a differential Galois
theory.


title:
Chip-level and multi-node analysis of energy-optimized lattice-Boltzmann
  CFD simulations

abstract:
  Memory-bound algorithms show complex performance and energy consumption
behavior on multicore processors. We choose the lattice-Boltzmann method (LBM)
on an Intel Sandy Bridge cluster as a prototype scenario to investigate if and
how single-chip performance and power characteristics can be generalized to the
highly parallel case. First we perform an analysis of a sparse-lattice LBM
implementation for complex geometries. Using a single-core performance model,
we predict the intra-chip saturation characteristics and the optimal operating
point in terms of energy to solution as a function of implementation details,
clock frequency, vectorization, and number of active cores per chip. We show
that high single-core performance and a correct choice of the number of active
cores per chip are the essential optimizations for lowest energy to solution at
minimal performance degradation. Then we extrapolate to the MPI-parallel level
and quantify the energy-saving potential of various optimizations and execution
modes, where we find these guidelines to be even more important, especially
when communication overhead is non-negligible. In our setup we could achieve
energy savings of 35% in this case, compared to a naive approach. We also
demonstrate that a simple non-reflective reduction of the clock speed leaves
most of the energy saving potential unused.


title:
Proofs of the Technical Results Justifying an Algorithm for Collision
  Avoidance in Dynamic Environments with Moving and Deforming Obstacles

abstract:
  This text presents the proofs of the technical facts underlying theoretical
justification of the convergence and performance of the novel algorithm for
reactive navigation of differential drive wheeled robots in dynamic uncertain
environments. The algorithm restricts neither the natures nor the motions of
the obstacles, they need not be rigid but conversely may deform. It does not
consume data about the velocities, shapes, sizes, or orientations of the
obstacles, and does not need a map of the environment or recognition of
individual obstacles. The only information about the scene is the current
distance to the nearest obstacle.


title:
Mapping the core mass function onto the stellar IMF: multiplicity
  matters

abstract:
  Observations indicate that the central portions of the Present-Day Prestellar
Core Mass Function (CMF) and the Stellar Initial Mass Function (IMF) both have
approximately log-normal shapes, but that the CMF is displaced to higher mass
than the IMF by a factor F = 4+/-1. This has lead to suggestions that the shape
of the IMF is directly inherited from the shape of the CMF - and therefore, by
implication, that there is a self-similar mapping from the CMF onto the IMF. If
we assume a self-similar mapping, it follows (i) that F = N0/eta, where eta is
the mean fraction of a core's mass that ends up in stars, and N0 is the mean
number of stars spawned by a single core; and (ii) that the stars spawned by a
single core must have an approximately log-normal distribution of relative
masses, with universal standard deviation sigma0. Observations can be expected
to deliver ever more accurate estimates of F, but this still leaves a
degeneracy between eta and N0; and sigma0 is also unconstrained by observation.
Here we show that these parameters can be estimated by invoking binary
statistics. Specifically, if (a) each core spawns one long-lived binary system,
and (b) the probability that a star of mass M is part of this long-lived binary
is proportional to M^alpha, current observations of the binary frequency as a
function of primary mass and the distribution of mass ratios strongly favour
eta = 1.0 +/- 0.3, N0 = 4.3 +/- 0.4, sigma0 = 0.3 +/- 0.03 and alpha = 0.9 +/-
0.6. The mapping from CMF to IMF is not necessarily self-similar - there are
many possible motivations for a non self-similar mapping - but if it is not,
then the shape of the IMF cannot be inherited from the CMF. Given the limited
observational constraints currently available and the ability of a self-similar
mapping to satisfy them, the possibility that the shape of the IMF is inherited
from the CMF cannot be ruled out at this juncture.


title: Magneto-Josephson effects and Majorana bound states in quantum wires

abstract:
  A prominent signature of Majorana bound states is the exotic Josephson
effects they produce, the classic example being a fractional Josephson current
with 4\pi periodicity in the phase difference across the junction. Recent work
established that topological insulator edges support a novel `magneto-Josephson
effect', whereby a dissipationless current exhibits 4\pi-periodic dependence
also on the relative orientation of the Zeeman fields in the two banks of the
junction. Here, we explore the magneto-Josephson effect in junctions based on
spin-orbit coupled quantum wires. In contrast to the topological insulator
case, the periodicities of the magneto-Josephson effect no longer follow from
an exact superconductor-magnetism duality of the Hamiltonian. We employ
numerical calculations as well as analytical arguments to identify the domain
configurations that display exotic Josephson physics for quantum-wire
junctions, and elucidate the characteristic differences with the corresponding
setups for topological insulators edges. To provide guidance to experiments, we
also estimate the magnitude of the magneto-Josephson effects in realistic
parameter regimes, and compare the Majorana-related contribution to the
coexisting 2\pi-periodic effects emerging from non-Majorana states.


title: Adaptive estimation under single-index constraint in a regression model

abstract:
  The problem of adaptive multivariate function estimation in the single-index
regression model with random design and weak assumptions on the noise is
investigated. A novel estimation procedure that adapts simultaneously to the
unknown index vector and the smoothness of the link function by selecting from
a family of specific kernel estimators is proposed. We establish a pointwise
oracle inequality which, in its turn, is used to judge the quality of
estimating the entire function (``global'' oracle inequality). Both the results
are applied to the problems of pointwise and global adaptive estimation over a
collection of H\"{o}lder and Nikol'skii functional classes, respectively.


title:
The Classification of Rational Subtangle Replacements between Rational
  Tangles

abstract:
  A natural generalization of a crossing change is a rational subtangle
replacement (RSR). We characterize the fundamental situation of the rational
tangles obtained from a given rational tangle via RSR, building on work of
Berge and Gabai, and determine the sites where these RSR may occur. In addition
we also determine the sites for RSR distance at least two between 2-bridge
links. These proofs depend on the geometry of the branched double cover.
Furthermore, we classify all knots in lens spaces whose exteriors are
generalized Seifert fibered spaces and their lens space surgeries, extending
work of Darcy-Sumners. This work is in part motivated by the common biological
situation of proteins cutting, rearranging and resealing DNA segments --
effectively performing RSR on DNA `tangles'.


title: Positive selection drives faster-Z evolution in silkmoths

abstract:
  Genes linked to X or Z chromosomes, which are hemizygous in the heterogametic
sex, are predicted to evolve at different rates than those on autosomes. This
faster-X effect can arise either as a consequence of hemizygosity, which leads
to more efficient selection for recessive beneficial mutations in the
heterogametic sex, or as a consequence of reduced effective population size of
the hemizygous chromosome, which leads to increased fixation of weakly
deleterious mutations due to random genetic drift. Empirical results to date
have suggested that, while the overall pattern across taxa is complicated, in
general systems with male-heterogamy show a faster-X effect primarily
attributable to more efficient selection while the only female-heterogamy taxon
studied to date (birds) shows a faster-Z effect primarily attributable to
increased drift. In order to test the generality of the faster-Z pattern seen
in birds, we sequenced the genome of the Lepidopteran insect Bombyx huttoni, a
close outgroup of the domesticated silkmoth Bombyx mori. We show that silkmoths
experience faster-Z evolution, but unlike in birds, the faster-Z effect appears
to be attributable to more efficient positive selection in females. These
results suggest that female-heterogamy alone is unlikely to be sufficient to
explain the reduced efficacy of selection on the bird Z chromosome. Instead, it
is likely that a combination of patterns of dosage compensation and overall
effective population size, among other factors, influence patterns of faster-Z
evolution.


title: Low-Reynolds number swimming in a capillary tube

abstract:
  We use the boundary element method to study the low-Reynolds number
locomotion of a spherical model microorganism in a circular tube. The swimmer
propels itself by tangen- tial or normal surface motion in a tube whose radius
is on the order of the swimmer size. Hydrodynamic interactions with the tube
walls significantly affect the average swimming speed and power consumption of
the model microorganism. In the case of swimming parallel to the tube axis, the
locomotion speed is always reduced (resp. increased) for swimmers with
tangential (resp. normal) deformation. In all cases, the rate of work nec-
essary for swimming is increased by confinement. Swimmers with no force-dipoles
in the far field generally follow helical trajectories, solely induced by
hydrodynamic interactions with the tube walls, and in qualitative agreement
with recent experimental observations for Paramecium. Swimmers of the puller
type always display stable locomotion at a lo- cation which depends on the
strength of their force dipoles: swimmers with weak dipoles (small {\alpha})
swim in the centre of the tube while those with strong dipoles (large {\alpha})
swim near the walls. In contrast, pusher swimmers and those employing normal
deformation are unstable and end up crashing into the walls of the tube.
Similar dynamics is observed for swimming into a curved tube. These results
could be relevant for the future design of artificial microswimmers in confined
geometries.


title: Polarization operator for plane-wave background fields

abstract:
  We derive an alternative representation of the leading-order contribution to
the polarization operator in strong-field quantum electrodynamics with a
plane-wave electromagnetic background field, which is manifestly symmetric with
respect to the external photon momenta. Our derivation is based on a direct
evaluation of the corresponding Feynman diagram, using the Volkov
representation of the dressed fermion propagator. Furthermore, the validity of
the Ward-Takahashi identity is shown for general loop diagrams in an external
plane-wave background field.


title: Gravitino dark matter production at finite temperature

abstract:
  The production and the final abundance of gravitino dark matter appear to
depend crucially on the restoration of the global U(1) $R$-symmetry of GMSB
sectors in a threefold way. An $R$-symmetric phase effectively suppresses the
production of goldstinos from scatterings with the supersymmetric Standard
Model particles and it generically initiates the goldstino production from the
thermalized messenger particles. In addition, the GMSB spurion gets displaced
from the zero temperature minimum and under certain conditions it dominates the
energy density of the universe producing late entropy. We show that it is
possible to have high enough reheating temperatures that thermal leptogenesis
and thermal vacuum selection can be realized without gravitino overproduction.
The gravitino dark matter can be produced either thermally or non-thermally. In
the former case the messenger scale has to be less than about $10^6$ GeV with
the gravitino relatively heavy, $m_{3/2}\geq {\cal O}(10)$ GeV. In the later
case, the gravitino is generically produced by the decay of the GMSB spurion
field a process that always takes place for large messenger scales. A
connection of our results with current collider and observational data is
performed.


title:
The prospects of forming ultracold molecules in $^2\Sigma$ states by
  magnetoassociation of alkali-metal atoms with Yb

abstract:
  We explore the feasibility of producing ultracold diatomic molecules with
nonzero electric and magnetic dipole moments by magnetically associating two
atoms, one with zero electron spin and one with nonzero spin. Feshbach
resonances arise through the dependence of the hyperfine coupling on
internuclear distance. We survey the Feshbach resonances in diatomic systems
combining the nine stable alkali-metal isotopes with those of Yb, focussing on
the illustrative examples of RbYb and CsYb. We show that the resonance widths
may expressed as a product of physically comprehensible terms in the framework
of Fermi's Golden Rule. The resonance widths depend strongly on the background
scattering length, which may be adjusted by selecting the Yb isotope, and on
the hyperfine coupling constant and the magnetic field. In favorable cases the
resonances may be over 100 mG wide.


title: Green functions, Segre numbers, and King's formula

abstract:
  Let $\mathcal J$ be a coherent ideal sheaf on a complex manifold $X$ with
zero set $Z$, and let $G$ be a plurisubharmonic function such that
$G=\log|f|+\mathcal O(1)$ locally at $Z$, where $f$ is a tuple of holomorphic
functions that defines $\mathcal J$. We give a meaning to the Monge-Amp\`{e}re
products $(dd^c G)^k$ for $k=0,1,2,...$, and prove that the Lelong numbers of
the currents $M_k^{\mathcal J}:=\mathbf 1_Z(dd^c G)^k$ at $x$ coincide with the
so-called Segre numbers of $\mathcal J$ at $x$, introduced independently by
Tworzewski, Gaffney-Gassler, and Achilles-Manaresi. More generally, we show
that $M_k^{\mathcal J}$ satisfy a certain generalization of the classical King
formula.


title:
Competition between three-sublattice order and superfluidity in the
  quantum 3-state Potts model of ultracold bosons and fermions on a square
  optical lattice

abstract:
  We study a quantum version of the three-state Potts model that includes as
special cases the effective models of bosons and fermions on the square lattice
in the Mott insulating limit. It can be viewed as a model of quantum
permutations with amplitudes J_parallel and J_perp for identical and different
colors, respectively. For J_parallel=J_perp>0, it is equivalent to the SU(3)
Heisenberg model, which describes the Mott insulating phase of 3-color
fermions, while the parameter range J_perp<min(0,-J_parallel) can be realized
in the Mott insulating phase of 3-color bosonic atoms. Using linear flavor wave
theory, infinite projected entangled-pair states (iPEPS), and continuous-time
quantum Monte-Carlo simulations, we construct the full T=0 phase diagram, and
we explore the T>0 properties for J_perp<0. For dominant antiferromagnetic
J_parallel interactions, a three-sublattice long-range ordered stripe state is
selected out of the ground state manifold of the antiferromagnetic Potts model
by quantum fluctuations. Upon increasing |J_perp|, this state is replaced by a
uniform superfluid for J_perp<0, and by an exotic three-sublattice superfluid
followed by a two-sublattice superfluid for J_perp>0. The transition out of the
uniform superfluid (that can be realized with bosons) is shown to be a peculiar
type of Kosterlitz-Thouless transition with three types of elementary vortices.


title: Radiative pT-broadening of high-energy quarks and gluons in QCD matter

abstract:
  We study radiative $p_{\perp}$-broadening of high energy quarks passing
through hot and cold QCD matter. With $L$ the length of the matter and $l_{0}$
the size of constituents of the matter we find $\avg{p_{\perp}^{2}}$ has both
double logarithmic terms, $\ln^{2}(L/l_{0})$, and single logarithmic terms,
$\ln(L/l_{0})$, coming from gluon radiation induced by the matter. We use a
(slight) extension of a formalism developed by B. Zakharov for studying energy
loss, a formalism which, for much of our calculation, reduces to a simple
dipole scattering analysis. We estimate the radiative contribution to be a
sizable correction to the nonradiative value of $\avg{p_{\perp}^{2}}$. We also
carry out a resummation of the double logarithmic terms that we find, and we
briefly discuss running coupling effects which appear here in a rather unusual
way.


title:
Large and moderate deviation principles for averaged stochastic
  approximation method for the estimation of a regression function

abstract:
  In this paper we prove large deviations principles for the averaged
stochastic approximation method for the estimation of a regression function
introduced by A. Mokkadem et al. [Revisiting R\'ev\'esz's stochastic
approximation method for the estimation of a regression function, ALEA Lat.
Amm. J. Probab. Math. Stat. 6 (2009), 63-114]. We show that the averaged
stochastic approximation algorithm constructed using the weight sequence which
minimize the asymptotic variance gives the same pointwise LDP as the
Nadaraya-Watson kernel estimator. Moreover, we give a moderate deviations
principle for these estimators. It turns out that the rate function obtained in
the moderate d\'eviations principle for the averaged stochastic approximation
algorithm constructed using the weight sequence which minimize the asymptotic
variance is larger than the one obtained for the Nadaraya-Watson estimator and
the one obtained for the semi-recursive estimator.


title:
Towards a general theory for coupling functions allowing persistent
  synchronization

abstract:
  We study synchronisation properties of networks of coupled dynamical systems
with interaction akin to diffusion. We assume that the isolated node dynamics
possesses a forward invariant set on which it has a bounded Jacobian, then we
characterise a class of coupling functions that allows for uniformly stable
synchronisation in connected complex networks --- in the sense that there is an
open neighbourhood of the initial conditions that is uniformly attracted
towards synchronisation. Moreover, this stable synchronisation persists under
perturbations to non-identical node dynamics. We illustrate the theory with
numerical examples and conclude with a discussion on embedding these results in
a more general framework of spectral dichotomies.


title:
Influence of surface centers on the effective surface recombination rate
  and the parameters of silicon solar cells

abstract:
  The results of our researches of the influence of exponentially distributed
surface centers on the effective surface recombination rate and the parameters
of silicon solar cells (SCs) are reported. In our calculations, we assumed the
acceptor and donor surface states to lie in the upper and lower, respectively,
parts of the bandgap. The model also supposed a discrete surface level to exist
in the middle of the energy gap. In the case where the integrated concentration
of continuously distributed centers is comparable with that of deep surface
levels, those centers can affect the SC parameters only due to the
recombination. If the concentration of continuously distributed centers is
comparable or higher than the concentration characterizing a charge built-in
into the insulator, those centers directly affect the surface band bending and
the photo-induced electromotive force. With the help of a computer simulation,
the conditions for the rate of surface recombination through continuously
distributed surface centers to exceed that through the deep discrete level are
determined. A decrease of the open-circuit voltage in inverted silicon SCs
associated with the recombination through continuously distributed centers is
calculated. The obtained theoretical results are compared with the experimental
data.


title:
Reconstructing the projected gravitational potential of galaxy clusters
  from galaxy kinematics

abstract:
  We develop a method for reconstructing the two-dimensional, projected
gravitational potential of galaxy clusters from observed line-of-sight velocity
dispersions of cluster galaxies. It is the third of an intended series of
papers aiming at a unique reconstruction method for cluster potentials
combining lensing, X-ray, Sunyaev-Zel'dovich and kinematic data. The observed
galaxy velocity dispersions are deprojected using the Richardson-Lucy
algorithm. The obtained radial velocity dispersions are then related to the
gravitational potential by using the tested assumption of a polytropic relation
between the effective galaxy pressure and the density. Once the gravitational
potential is obtained in three dimensions, projection along the line-of-sight
yields the two-dimensional potential. For simplicity we adopt spherical
symmetry and a known profile for the anisotropy parameter of the galaxy
velocity dispersions. We test the method with a numerically simulated galaxy
cluster and galaxies identified therein. We extract a projected
velocity-dispersion profile from the simulated cluster and pass it through our
algorithm, showing that the deviation between the true and the reconstructed
gravitational potential is less then 10% within approximately 1.2 Mpc/h from
the cluster centre.


title: Quantum Energy Inequality for the Massive Ising Model

abstract:
  A Quantum Energy Inequality (QEI) is derived for the massive Ising model,
giving a state-independent lower bound on suitable averages of the energy
density; the first QEI to be established for an interacting quantum field
theory with nontrivial S-matrix. It is shown that the Ising model has
one-particle states with locally negative energy densities, and that the energy
density operator is not additive with respect to combination of one-particle
states into multi-particle configurations.


title:
Close Stellar Encounters in Young, Substructured, Dissolving Star
  Clusters: Statistics and Effects on Planetary Systems

abstract:
  Both simulations and observations indicate that stars form in filamentary,
hierarchically clustered associations, most of which disperse into their
galactic field once feedback destroys their parent clouds. However, during
their early evolution in these substructured environments, stars can undergo
close encounters with one another that might have significant impacts on their
protoplanetary disks or young planetary systems. We perform N-body simulations
of the early evolution of dissolving, substructured clusters with a wide range
of properties, with the aim of quantifying the expected number and orbital
element distributions of encounters as a function of cluster properties. We
show that the presence of substructure both boosts the encounter rate and
modifies the distribution of encounter velocities compared to what would be
expected for a dynamically relaxed cluster. However, the boost only lasts for a
dynamical time, and as a result the overall number of encounters expected
remains low enough that gravitational stripping is unlikely to be a significant
effect for the vast majority of star-forming environments in the Galaxy. We
briefly discuss the implications of this result for models of the origin of the
Solar System, and of free-floating planets. We also provide tabulated encounter
rates and orbital element distributions suitable for inclusion in population
synthesis models of planet formation in a clustered environment.


title:
Large-scale nuclear structure calculations for spin-dependent WIMP
  scattering with chiral effective field theory currents

abstract:
  We perform state-of-the-art large-scale shell-model calculations of the
structure factors for elastic spin-dependent WIMP scattering off 129,131Xe,
127I, 73Ge, 19F, 23Na, 27Al, and 29Si. This comprehensive survey covers the
non-zero-spin nuclei relevant to direct dark matter detection. We include a
pedagogical presentation of the formalism necessary to describe elastic and
inelastic WIMP-nucleus scattering. The valence spaces and nuclear interactions
employed have been previously used in nuclear structure calculations for these
mass regions and yield a good spectroscopic description of these isotopes. We
use spin-dependent WIMP-nucleus currents based on chiral effective field theory
(EFT) at the one-body level and including the leading long-range two-body
currents due to pion exchange, which are predicted in chiral EFT. Results for
all structure factors are provided with theoretical error bands due to the
nuclear uncertainties of WIMP currents in nuclei.


title: Recurrence of Products of Linear Recursive Functions

abstract:
  We study the recurrence of the product of n functions, each of which
satisfies the same recurrence relation.


title: A quantum gravitational inflationary scenario in Bianchi-I spacetime

abstract:
  We investigate the $\phi^2$ inflationary model in the Bianchi-I spacetime
using effective spacetime description of loop quantum cosmology to understand
the issues of the resolution of initial singularity, isotropization, effect of
anisotropies on amount of inflation, and the phase space attractors in the
presence of non-perturbative quantum gravitational modifications. A comparative
analysis with the classical theory by including more general initial conditions
than the ones previously considered in the latter is also performed. We show
that, in general, the classical singularity is replaced by a bounce of the mean
scale factor in loop quantum cosmology. Due to the underlying quantum geometric
effects, the energy density of the inflaton and the anisotropic shear remain
bounded throughout the non-singular evolution. Starting from arbitrary
anisotropic initial conditions, a loop quantum universe isotropizes either
before or soon after the onset of slow-roll inflation. We find a double
attractor behavior in the phase space dynamics of loop quantum cosmology,
similar to the one in classical theory, but with some additional subtle
features. Quantum modifications to the dynamical equations are such that,
unlike the classical theory, the amount of inflation does not monotonically
depend on the initial anisotropy in loop quantum cosmology. Our results suggest
that a viable non-singular inflationary model can be constructed from highly
anisotropic initial conditions in the Planck regime.


title:
A Nonmonotone Analysis with the Primal-Dual Approach: online routing of
  virtual circuits with unknown durations

abstract:
  We address the question of whether the primal-dual approach for the design
and analysis of online algorithms can be applied to nonmonotone problems. We
provide a positive answer by presenting a primal-dual analysis to the online
algorithm of Awerbuch et al.[AAPW01] for routing virtual circuits with unknown
durations.


title:
Antiphase Synchronization in a Flagellar-Dominance Mutant of
  Chlamydomonas

abstract:
  Groups of beating flagella or cilia often synchronize so that neighboring
filaments have identical frequencies and phases. A prime example is provided by
the unicellular biflagellate Chlamydomonas reinhardtii, which typically
displays synchronous in-phase beating in a low-Reynolds number version of
breaststroke swimming. We report here the discovery that ptx1, a flagellar
dominance mutant of C. reinhardtii, can exhibit synchronization in precise
antiphase, as in the freestyle swimming stroke. Long-duration high-speed
imaging shows that ptx1 flagella switch stochastically between in-phase and
antiphase states, and that the latter has a distinct waveform and significantly
higher frequency, both of which are strikingly similar to those found during
phase slips that stochastically interrupt in-phase beating of the wildtype.
Possible mechanisms underlying these observations are discussed.

categories: physics.bio-ph cond-mat.soft physics.flu-dyn q-bio.CB