title: On the Ultraviolet to Infrared Evolution of Chiral Gauge Theories

abstract:
  We discuss the ultraviolet (UV) to infrared (IR) evolution of asymptotically
free chiral gauge theories. Various types of IR behavior are considered,
including confinement without spontaneous chiral symmetry breaking, and
formation of bilinear fermion condensates that preserve or dynamically break
the chiral gauge invariance. We compare different schemes for the study of this
evolution and the resultant IR structure of the theories, including a
conjectured inequality based on the counting of degrees of freedom. We note
some new patterns of UV to IR evolution.


title:
Cryptic Genetic Variation Can Make Irreducible Complexity a Common Mode
  of Adaptation

abstract:
  The existence of complex (multiple-step) genetic adaptations that are
"irreducible" (i.e., all partial combinations are less fit than the original
genotype) is one of the longest standing problems in evolutionary biology. In
standard genetics parlance, these adaptations require the crossing of a wide
adaptive valley of deleterious intermediate stages. Here we demonstrate, using
a simple model, that evolution can cross wide valleys to produce "irreducibly
complex" adaptations by making use of previously cryptic mutations. When
revealed by an evolutionary capacitor, previously cryptic mutants have higher
initial frequencies than do new mutations, bringing them closer to a
valley-crossing saddle in allele frequency space. Moreover, simple
combinatorics imply an enormous number of candidate combinations exist within
available cryptic genetic variation. We model the dynamics of crossing of a
wide adaptive valley after a capacitance event using both numerical simulations
and analytical approximations. Although individual valley crossing events
become less likely as valleys widen, by taking the combinatorics of genotype
space into account, we see that revealing cryptic variation can cause the
frequent evolution of complex adaptations. This finding also effectively
dismantles "irreducible complexity" as an argument against evolution by
providing a general mechanism for crossing wide adaptive valleys.


title:
On the internalisation, intraplasmodial carriage and excretion of
  metallic nanoparticles in the slime mould Physarum polycephalum

abstract:
  The plasmodium of Physarum polycephalum is a large single cell visible with
the naked eye. When inoculated on a substrate with attractants and repellents
the plasmodium develops optimal networks of protoplasmic tubes which span sites
of attractants (i.e. nutrients) yet avoid domains with a high nutrient
concentration. It should therefore be possible to program the plasmodium
towards deterministic adaptive transformation of internalised nano- and
micro-scale materials. In laboratory experiments with magnetite nanoparticles
and glass micro-spheres coated with silver metal we demonstrate that the
plasmodium of P. polycephalum can propagate the nano-scale objects using a
number of distinct mechanisms including endocytosis, transcytosis and dragging.
The results of our experiments could be used in the development of novel
techniques targeted towards the growth of metallised biological wires and
hybrid nano- and micro-circuits.


title: Synchrosqueezed Curvelet Transform for 2D Mode Decomposition

abstract:
  This paper introduces the synchrosqueezed curvelet transform as an optimal
tool for 2D mode decomposition of wavefronts or banded wave-like components.
The synchrosqueezed curvelet transform consists of a generalized curvelet
transform with application dependent geometric scaling parameters, and a
synchrosqueezing technique for a sharpened phase space representation. In the
case of a superposition of banded wave-like components with well-separated
wave-vectors, it is proved that the synchrosqueezed curvelet transform is
capable of recognizing each component and precisely estimating local
wave-vectors. A discrete analogue of the continuous transform and several
clustering models for decomposition are proposed in detail. Some numerical
examples with synthetic and real data are provided to demonstrate the above
properties of the proposed transform.


title: The effect of pump depletion on reversible photodegradation

abstract:
  We model the effect of pump depletion on reversible photodegradation using
the extended domain model[Anderson and Kuzyk, arXiv:1309.5176v1, 2013] and the
Beer-Lambert law. We find that neglecting pump absorption in the analysis of
the linear optical transmittance leads to an underestimate of the degree and
rate of photodegradation. The model is used to accurately measure the molecular
absorbance cross sections of the three species involved in photodegradation of
disperse orange 11 dye in (poly)methyl-methacralate polymer (DO11/PMMA).
Finally we find that the processing history of a dye-doped polymer affects
reversible photodegradation, with polymerized monomer solutions of DO11 being
more photostable than those prepared from solvent evaporated dye-polymer
solutions.


title: Rigidity of time-flat surfaces in the Minkowski spacetime

abstract:
  A time-flat condition on spacelike 2-surfaces in spacetime is considered
here. This condition is analogous to constant torsion condition for curves in
three dimensional space and has been studied in [2, 4, 5, 12, 13]. In
particular, any 2-surface in a static slice of a static spacetime is time-flat.
In this article, we address the question in the title and prove several local
and global rigidity theorems for such surfaces in the Minkowski spacetime.


title: DYNAMO I: A Sample of Ha-Luminous Galaxies with Resolved Kinematics

abstract:
  (abridged) DYNAMO is a multi-wavelength, spatially-resolved survey of local
($z \sim 0.1$) star-forming galaxies designed to study evolution through
comparison with samples at z~2. Half of the sample has integrated H-alpha
luminosities of >$10^{42}$ erg/s, the typical lower limit for resolved
spectroscopy at z~2. The sample covers a range in stellar mass
($10^9$-$10^{11}$ Msun) and star-formation rate (0.2-100 Msun/yr). In this
first paper of a series, we present integral-field spectroscopy of H-alpha
emission for the sample of 67 galaxies. We infer gas fractions in our sample as
high as ~0.8, higher than typical for local galaxies. Gas fraction correlates
with stellar mass in galaxies with star-formation rates below 10 Msun/yr, as
found by COLDGASS, but galaxies with higher star-formation rates have higher
than expected gas fractions. There is only a weak correlation, if any, between
gas fraction and gas velocity dispersion. Galaxies in the sample visually
classified as disc-like are offset from the local stellar-mass Tully-Fisher
relation to higher circular velocities, but this offset vanishes when both gas
and stars are included in the baryonic Tully-Fisher relation. The mean gas
velocity dispersion of the sample is ~50 km/s, and V/sigma ranges from 2 to 10
for most of the discs, similar to 'turbulent' galaxies at high redshift. Half
of our sample show disc-like rotation, while ~20 percent show no signs of
rotation. The division between rotating and non-rotating is approximately...


title: Extensions of Poisson Structures on Singular Hypersurfaces

abstract:
  Fix a codimension-1 affine Poisson variety $(X,\pi_X)$ in $\mathbb{C}^n$ with
an isolated singularity at the origin. We characterize possible extensions of
$\pi_X$ to $\mathbb{C}^n$ using the Koszul complex of the Jacobian ideal of
$X$. In the particular case of a singular surface, we show that there always
exists an extension of $\pi_X$ to $\mathbb{C}^n$.


title: Monotone Grid Drawings of Planar Graphs

abstract:
  A monotone drawing of a planar graph $G$ is a planar straight-line drawing of
$G$ where a monotone path exists between every pair of vertices of $G$ in some
direction. Recently monotone drawings of planar graphs have been proposed as a
new standard for visualizing graphs. A monotone drawing of a planar graph is a
monotone grid drawing if every vertex in the drawing is drawn on a grid point.
In this paper we study monotone grid drawings of planar graphs in a variable
embedding setting. We show that every connected planar graph of $n$ vertices
has a monotone grid drawing on a grid of size $O(n)\times O(n^2)$, and such a
drawing can be found in O(n) time.


title:
Nitrogen-Doped Graphene Sheets Grown by Chemical Vapor Deposition:
  Synthesis and Influence of Nitrogen Impurities on Carrier Transport

abstract:
  A significant advance toward achieving practical applications of graphene as
a two-dimensional material in nanoelectronics would be provided by successful
synthesis of both n-type and p-type doped graphene. However reliable doping and
a thorough understanding of carrier transport in the presence of charged
impurities governed by ionized donors or acceptors in the graphene lattice are
still lacking. Here we report experimental realization of few-layer
nitrogen-doped (N-doped) graphene sheets by chemical vapor deposition of
organic molecule 1, 3, 5-triazine on Cu metal catalyst. By reducing the growth
temperature, the atomic percentage of nitrogen doping is raised from 2.1 % to
5.6 %. With increasing doping concentration, N-doped graphene sheet exhibits a
crossover from p-type to n-type behavior accompanied by a strong enhancement of
electron-hole transport asymmetry, manifesting the influence of incorporated
nitrogen impurities. In addition, by analyzing the data of X-ray photoelectron
spectroscopy, Raman spectroscopy, and electrical measurements, we show that
pyridinic and pyrrolic N impurities play an important role in determining the
transport behavior of carriers in N-doped graphene sheets.


title: Non-Ohmic behavior of carrier transport in highly disordered graphene

abstract:
  We report measurements of disordered graphene probed by both a high electric
field and a high magnetic field. By apply a high source-drain voltage Vsd, we
are able to study the current-voltage relation I-Vsd of our device. With
increasing Vsd, a crossover from the linear I-Vsd regime to the non-linear one,
and eventually to activationless-hopping transport occurs. In the
activationless-hopping regime, the importance of Coulomb interactions between
charged carriers is demonstrated. Moreover, we show that delocalization of
carriers which are strongly localized at low T and at small Vsd occurs with the
presence of high electric field and perpendicular magnetic field..

categories: cond-mat.mes-hall cond-mat.dis-nn cond-mat.mtrl-sci cond-mat.str-el


title:
Report of the Snowmass 2013 Computing Frontier working group on Lattice
  Field Theory -- Lattice field theory for the energy and intensity frontiers:
  Scientific goals and computing needs

abstract:
  This is the report of the Computing Frontier working group on Lattice Field
Theory prepared for the proceedings of the 2013 Community Summer Study
("Snowmass"). We present the future computing needs and plans of the U.S.
lattice gauge theory community and argue that continued support of the U.S.
(and worldwide) lattice-QCD effort is essential to fully capitalize on the
enormous investment in the high-energy physics experimental program. We first
summarize the dramatic progress of numerical lattice-QCD simulations in the
past decade, with some emphasis on calculations carried out under the auspices
of the U.S. Lattice-QCD Collaboration, and describe a broad program of
lattice-QCD calculations that will be relevant for future experiments at the
intensity and energy frontiers. We then present details of the computational
hardware and software resources needed to undertake these calculations.


title: Twisted period relations for Lauricella's hypergeometric function F_A

abstract:
  We study Lauricella's hypergeometric function $F_A$ of $m$-variables and the
system $E_A$ of differential equations annihilating $F_A$, by using twisted
(co)homology groups. We construct twisted cycles with respect to an integral
representation of Euler type of $F_A$. These cycles correspond to $2^m$
linearly independent solutions to $E_A$, which are expressed by hypergeometric
series $F_A$. Using intersection forms of twisted (co)homology groups, we
obtain twisted period relations which give quadratic relations for Lauricella's
$F_A$.


title:
Experimental constraints on anti-gravity and antimatter, in the context
  of dark energy

abstract:
  In a paper by Villata (2011), the possibility of a repulsive gravitational
interaction between antimatter and ordinary matter was discussed. The author
argued that this anti-gravity can be regarded as a prediction of general
relativity, under the assumption of CPT symmetry. Stringent experimental
constraints have been established against such a suggestion. The measurement of
free-fall accelerations of various nuclei by the Eot-Wash group and searches
for equivalence principle violation through the gravitational splitting in kaon
physics consistently establish null results on any difference between the
gravitational behaviour of antimatter and ordinary matter. The original
arguments against antigravity were questioned by Nieto & Goldman (1991). In the
light of new experiments as well as theoretical developments in the past 20
years, some of Nieto & Goldman's concerns have been addressed. While a precise
measurement of the free-fall acceleration of antihydrogen will eventually lay
this issue to rest, the purpose of this short letter is to argue that the
substitution of dark energy with anti-gravity by antimatter, as suggested by
Villata, is highly unlikely.


title: NLO corrections in the initial-state parton shower Monte Carlo

abstract:
  The decade-old technique of combining NLO-corrected hard process with
LO-level parton shower Monte Carlo is now mature and used in practice of the
QCD calculations in the LHC data analysis. The next step, its extension to an
NNLO-corrected hard process combined with the NLO-level parton shower Monte
Carlo, will require development of the latter component. It does not exist yet
in a complete form. In this note we describe recent progress in developing the
NLO parton shower for the initial-state hadron beams. The technique of adding
NLO corrections in the fully exclusive form (defined in recent years) is now
simplified and tested numerically, albeit for a limited set of NLO diagrams in
the evolution kernels.


title: Weak Integer Additive Set-Indexers of Certain Graph Operations

abstract:
  An integer additive set-indexer is defined as an injective function
$f:V(G)\rightarrow 2^{\mathbb{N}_0}$ such that the induced function $g_f:E(G)
\rightarrow 2^{\mathbb{N}_0}$ defined by $g_f (uv) = f(u)+ f(v)$ is also
injective, where $f(u)+f(v)$ is the sum set of $f(u)$ and $f(v)$ and
$\mathbb{N}_0$ is the set of all non-negative integers. If $g_f(uv)=k \forall
uv\in E(G)$, then $f$ is said to be a $k$-uniform integer additive
set-indexers. An integer additive set-indexer $f$ is said to be a weak integer
additive set-indexer if $|g_f(uv)|=max(|f(u)|,|f(v)|) \forall uv\in E(G)$. A
weak integer additive set-indexer $f$ is called a weakly $k$-uniform integer
additive set-indexer if $g_f(e)=k \forall e\in E(G)$. We have some
characteristics of the graphs which admit weak and weakly uniform integer
additive set-indexers. In this paper, we study the admissibility of weak
integer additive set-indexer by certain graphs and finite graph operations.


title:
A Ray-based Approach for Boundary Estimation of Fiber Bundles Derived
  from Diffusion Tensor Imaging

abstract:
  Diffusion Tensor Imaging (DTI) is a non-invasive imaging technique that
allows estimation of the location of white matter tracts in-vivo, based on the
measurement of water diffusion properties. For each voxel, a second-order
tensor can be calculated by using diffusion-weighted sequences (DWI) that are
sensitive to the random motion of water molecules. Given at least 6
diffusion-weighted images with different gradients and one unweighted image,
the coefficients of the symmetric diffusion tensor matrix can be calculated.
Deriving the eigensystem of the tensor, the eigenvectors and eigenvalues can be
calculated to describe the three main directions of diffusion and its
magnitude. Using DTI data, fiber bundles can be determined, to gain information
about eloquent brain structures. Especially in neurosurgery, information about
location and dimension of eloquent structures like the corticospinal tract or
the visual pathways is of major interest. Therefore, the fiber bundle boundary
has to be determined. In this paper, a novel ray-based approach for boundary
estimation of tubular structures is presented.


title: Constraining UHECR source models by the TA SD energy spectrum

abstract:
  We have published the energy spectrum of ultra-high energy cosmic rays
(UHECRs) for E > 10^18.2 eV from our first 5-year observation with the surface
detectors of Telescope Array. We found two breaking points in the power-law
spectrum, a flattening known as the "ankle" or "dip" at E = 10^18.66 eV, and a
steepening at E = 10^19.72 eV. The spectral features must be related to
distribution of cosmic ray sources, injection spectrum, and energy loss
processes during propagation in inter-galactic space. We constructed a model of
source distribution of UHECRs and energy loss processes in the CMB photon field
to calculate energy spectrum to be observed at the Earth. The model includes
injection energy spectra at the sources, energy loss processes, and evolution
of cosmic ray fluxes with red shift. We consider two cases that the UHECR
sources are distributed uniformly, or same as galaxies in the local universe.
We found that the spectrum can be well fitted with the model. We discuss to
give a constraint to the model parameters, e.g. the injection power indices and
cosmological evolution from the observed data.


title:
Effective thermal conductivity of helium II: from Landau to
  Gorter-Mellink regimes

abstract:
  The size-dependent and flux-dependent effective thermal conductivity of
narrow channels filled with He II is analyzed. The classical Landau evaluation
of the effective thermal conductivity of quiescent He II is extended to
describe the transition to fully turbulent regime, where the heat flux is
proportional to the cubic root of the temperature gradient (Gorter-Mellink
regime). To do so we use an expression for the quantum vortex line density $L$
in terms of the heat flux considering the influence of the walls. From it, and
taking into account the friction force of normal component against the
vortices, we compute the effective thermal conductivity.


title: A Rotating Black Hole Solution for Shape Dynamics

abstract:
  Shape dynamics is a classical theory of gravity which agrees with general
relativity in many important aspects, but which possesses different gauge
symmetries and can present some fundamental global differences with respect to
Einstein spacetimes. Here, we present a general procedure for (locally) mapping
stationary, axisymmetric general relativity solutions onto their shape dynamic
counterparts. We focus in particular on the rotating black hole solution for
shape dynamics and show that many of the properties of the spherically
symmetric solution are preserved in the extension to the axisymmetric case: it
is also free of physical singularities, it does not form a space-time at the
horizon, and it possesses an inversion symmetry about the horizon which leads
to us to interpret the solution as a wormhole.


title:
The Concept of Heterogeneous Scattering Coefficients and Its Application
  in Inverse Medium Scattering

abstract:
  This work investigates the scattering coefficients for inverse medium
scattering problems. It shows some fundamental properties of the coefficients
such as symmetry and tensorial properties. The relationship between the
scattering coefficients and the far-field pattern is also derived. Furthermore,
the sensitivity of the scattering coefficients with respect to changes in the
permittivity and permeability distributions is investigated. In the linearized
case, explicit formulas for reconstructing permittivity and permeability
distributions from the scattering coefficients is proposed. They relate the
exponentially ill-posed character of the inverse medium scattering problem at a
fixed frequency to the exponential decay of the scattering coefficients.
Moreover, they show the stability of the reconstruction from multifrequency
measurements. This provides a new direction for solving inverse medium
scattering problems.


title:
Electron Correlations and Two-Photon States in Polycyclic Aromatic
  Hydrocarbon Molecules: A Peculiar Role of Geometry

abstract:
  We present numerical studies of one- and two-photon excited states ordering
in a number of polycyclic aromatic hydrocarbon molecules: coronene,
hexa-peri-hexabenzocoronene and circumcoronene, all possessing $D_{6h}$ point
group symmetry versus ovalene with $D_{2h}$ symmetry, within the
Pariser-Parr-Pople model of interacting $\pi$-electrons. The calculated
energies of the two-photon states as well as their relative two-photon
absorption cross-sections within the interacting model are qualitatively
different from single-particle descriptions. More remarkably, a peculiar role
of molecular geometry is found. The consequence of electron correlations is far
stronger for ovalene, where the lowest spin-singlet two-photon state is a
quantum superposition of pairs of lowest spin triplet states, as in the linear
polyenes. The same is not true for $D_{6h}$ group hydrocarbons. Our work
indicates significant covalent character, in valence bond language, of the
ground state, the lowest spin triplet state and a few of the lowest two-photon
states in $D_{2h}$ ovalene but not in those with $D_{6h}$ symmetry.


title: Optimal Shape Design by Partial Spectral Data

abstract:
  In this paper, we are concerned with a shape design problem, in which our
target is to design, up to rigid transformations and scaling, the shape of an
object given either its polarization tensor at multiple contrasts or the
partial eigenvalues of its Neumann-Poincar\'e operator, which are known as the
Fredholm eigenvalues. We begin by proposing to recover the eigenvalues of the
Neumann-Poincar\'e operator from the polarization tensor by means of the
holomorphic functional calculus. Then we develop a regularized Gauss-Newton
optimization method for the shape reconstruction process. We present numerical
results to demonstrate the effectiveness of the proposed methods and to
illustrate important properties of the Fredholm eigenvalues and their
associated eigenfunctions. Our results are expected to have important
applications in the design of plasmon resonances in nanoparticles as well as in
the multifrequency or pulsed imaging of small anomalies.


title:
Search for the $\eta_c(2S)/h_c\to p\bar{p}$ decays and measurements of
  the $\chi_{cJ}\to p\bar{p}$ branching fractions

abstract:
  Using a sample of $1.06\times10^{8}~\psi(3686)$ events collected with the
BESIII detector at BEPCII, the decays $\eta_{c}(2S)\to p\bar{p}$ and $h_{c}\to
p\bar{p}$ are searched for, where $\eta_c(2S)$ and $h_c$ are reconstructed in
the decay chains $\psi(3686)\to\gamma\eta_{c}(2S)$, $\eta_{c}(2S)\to p\bar{p}$
and $\psi(3686)\to\pi^{0}h_{c}$, $h_{c}\to p\bar{p}$, respectively. No
significant signals are observed. The upper limits of the product branching
fractions are determined to be
$\mathcal{B}(\psi(3686)\to\gamma\eta_c(2S))\times\mathcal{B}(\eta_{c}(2S)\to
p\bar{p})<1.4\times10^{-6}$ and
$\mathcal{B}(\psi(3686)\to\pi^0h_c)\times\mathcal{B}(h_{c}\to
p\bar{p})<1.3\times10^{-7}$ at the 90% C.L.. The branching fractions for
$\chi_{cJ}\to p\bar{p}$ $(J=0,~1,~2)$ are also measured to be
$(24.5\pm0.8\pm1.3,~8.6\pm0.5\pm0.5,~8.4\pm0.5\pm0.5)\times10^{-5}$, which are
the world's most precise measurements.


title: Topological spaces associated to higher-rank graphs

abstract:
  We investigate which topological spaces can be constructed as topological
realisations of higher-rank graphs. We describe equivalence relations on
higher-rank graphs for which the quotient is again a higher-rank graph, and
show that identifying isomorphic co-hereditary subgraphs in a disjoint union of
two rank-$k$ graphs gives rise to pullbacks of the associated $C^*$-algebras.
We describe a combinatorial version of the connected-sum operation and apply it
to the rank-2-graph realisations of the four basic surfaces to deduce that
every compact 2-manifold is the topological realisation of a rank-2 graph. We
also show how to construct $k$-spheres and wedges of $k$-spheres as topological
realisations of rank-$k$ graphs.


title:
Analytic treatment of the charged black-hole-mirror bomb in the highly
  explosive regime

abstract:
  A charged scalar field impinging upon a charged Reissner-Nordstrom black hole
can be amplified as it scatters off the hole, a phenomenon known as
superradiant scattering. This scattering process in the superradiant regime
w<qQ/r_+ (here w, q, Q, and r_{+-} are the conserved frequency of the wave, the
charge coupling constant of the field, the electric charge of the black hole,
and the horizon radii of the black hole, respectively) results in the
extraction of Coulomb energy and electric charge from the charged black hole.
The black-hole-field system can be made unstable by placing a reflecting mirror
around the black hole which prevents the amplified field from escaping to
infinity. This charged black-hole-mirror system is the spherically symmetric
analogue of the rotating black-hole-mirror bomb of Press and Teukolsky. In the
present paper we study analytically the charged black-hole-mirror bomb in the
asymptotic regime qQ>>1 and for mirror radii r_m in the near-horizon region
x_m=(r_m-r_+)/r_+<<tau, where tau=(r_+-r_-)/r_+ is the dimensionless
temperature of the black hole. In particular, we derive analytic expressions
for the oscillation frequencies w_R and the instability growth timescales 1/w_I
of the superradiant confined fields. Remarkably, we find a simple linear
scaling w_I \propto qQ/r_+ for the imaginary part of the resonances in the
asymptotic qQ>>(tau/x_m)^2>>1 regime, which implies that the instability
timescale 1/w_I of the system can be made arbitrarily short in the
qQ-->infinity limit. The short instability timescale found in the linear regime
along with the spherical symmetry of the system, make the charged bomb a
convenient toy model for future numerical studies aimed to investigate the
non-linear end-state of superradiant instabilities.


title:
Field-induced inhomogeneous ground states of antiferromagnetic ANNNI
  chains

abstract:
  Finite-size effects are studied in ground states of antiferromagnetic (AF)
ANNNI chains in a field. It is shown that field can induce a variety of
inhomogeneous states in finite chains. They are composed of two shifted AF
states with the kink at their junction and are highly degenerate with respect
to the kink position. The phase diagram field-exchange ratio for finite chains
is presented.


title:
Dynamics of two atoms undergoing light-assisted collisions in an optical
  microtrap

abstract:
  We study the dynamics of atoms in optical traps when exposed to laser cooling
light that induces light-assisted collisions. We experimentally prepare
individual atom pairs and observe their evolution. Due to the simplicity of the
system (just two atoms in a microtrap) we can directly simulate the pair's
dynamics, thereby revealing detailed insight into it. We find that often only
one of the collision partners gets expelled, similar to when using blue detuned
light for inducing the collisions. This enhances schemes for using
light-assisted collisions to prepare individual atoms and affects other
applications as well.


title:
Search for $^6_\Lambda$H hypernucleus by the $^6$Li$(\pi^-,K^+)$
  reaction at $p_{\pi^-}$ = 1.2 GeV/$c$

abstract:
  We have carried out an experiment to search for a neutron-rich hypernucleus,
$^6_{\Lambda}$H, by the $^6$Li($\pi^-,K^+$) reaction at $p_{\pi^-}$ =1.2
GeV/$c$. The obtained missing mass spectrum with an estimated energy resolution
of 3.2 MeV (FWHM) showed no peak structure corresponding to the $^6_{\Lambda}$H
hypernucleus neither below nor above the $^4_{\Lambda}$H$+2n$ particle decay
threshold. An upper limit of the production cross section for the bound
$^6_{\Lambda}$H hypernucleus was estimated to be 1.2 nb/sr at 90% confidence
level.


title: Singlet Mott State Simulating the Bosonic Laughlin Wave Function

abstract:
  We study properties of a class of spin singlet Mott states for arbitrary spin
S bosons on a lattice, with particle number per cite n=S/l+1, where l is a
positive integer. We show that such a singlet Mott state can be mapped to a
bosonic Laughlin wave function on the sphere with a finite number of particles
at filling {\nu}=1/2l. Spin, particle and hole excitations in the Mott state
are discussed, among which the hole excitation can be mapped to the quasi-hole
of the bosonic Laughlin wave function. We show that this singlet Mott state can
be realized in a cold atom system on optical lattice, and can be identified
using Bragg spectroscopy and Stern-Gerlach techniques. This class of singlet
Mott states may be generalized to simulate bosonic Laughlin states with filling
{\nu}=q/2l.


title: A generalization of Hilbert's inequality

abstract:
  In a generalization of the classical Hilbert inequality by Hardy, Littlewood
and P\'{o}lya, the best constant for an inequality is determined provided that
the generating function for the corresponding matrix satisfies certain
monotonicity condition. In this paper, we determine the best constant for a
class of inequalities when the monotonicity condition is no longer satisfied.


title: Asymptotic properties of zeta functions over finite fields

abstract:
  In this paper we study asymptotic properties of families of zeta and
$L$-functions over finite fields. We do it in the context of three main
problems: the basic inequality, the Brauer--Siegel type results and the results
on distribution of zeroes. We generalize to this abstract setting the results
of Tsfasman, Vl\u{a}du\c{t} and Lachaud, who studied similar problems for
curves and (in some cases) for varieties over finite fields. In the classical
case of zeta functions of curves we extend a result of Ihara on the limit
behaviour of the Euler--Kronecker constant. Our results also apply to
$L$-functions of elliptic surfaces over finite fields, where we approach the
Brauer--Siegel type conjectures recently made by Kunyavskii, Tsfasman and
Hindry.


title:
Exchange-dominated Standing Spin Wave Excitations under microwave
  irradiation in Ni80Fe20 Thin Films

abstract:
  We investigated the microwave-assisted DC voltages of ferromagnetic
resonances and exchangedominated standing spin wave excitations in two
different in-plane magnetized permalloy thin films via homodyne detection. The
line shapes of ferromagnetic resonance spectra and the dispersion curves of
ferromagnetic resonance and standing spin wave are in agreement of previous
studies, while further investigations of DC voltage spectra for these two
excitations reveal that 1. unlike ferromagnetic resonance signals, the
anti-symmetrical line shapes of standing spin wave excitations are not depend
on the electromagnetic relative phase of assisted microwave, and 2. linewidths
of their DC voltage spectra are distinct. The complicated spin dynamics of
standing spin wave is consequently discussed by applying
Landau-Lifshitz-Gilbert equation in term of exchange interaction.


title:
Exploring the evolution of color-luminosity parameter $\beta$ and its
  effects on parameter estimation

abstract:
  It has been found in previous studies that, for the Supernova Legacy Survey
three-year (SNLS3) data, there is strong evidence for the redshift-evolution of
color-luminosity parameter $\beta$. In this paper, using three simplest dark
energy models ($\Lambda$CDM, $w$CDM, and CPL), we further explore the evolution
of $\beta$ and its effects on parameter estimation. In addition to the SNLS3
data, we also take into account the Planck distance priors data, as well as the
latest galaxy clustering (GC) data extracted from SDSS DR7 and BOSS. We find
that, for all the models, adding a parameter of $\beta$ can reduce
$\chi^2_{min}$ by $\sim$ 36, indicating that $\beta_1 = 0$ is ruled out at
6$\sigma$ confidence levels. In other words, $\beta$ deviates from a constant
at 6$\sigma$ confidence levels. This conclusion is insensitive to the dark
energy models considered, showing the importance of considering the evolution
of $\beta$ in the cosmology-fits. Furthermore, it is found that varying $\beta$
can significantly change the fitting results of various cosmological
parameters: using the SNLS3 data alone, varying $\beta$ yields a larger
$\Omega_m$ for the $\Lambda$CDM model; using the SNLS3+CMB+GC data, varying
$\beta$ yields a larger $\Omega_m$ and a smaller $h$ for all the models.
Moreover, we find that these results are much closer to those given by the
CMB+GC data, compared to the cases of treating $\beta$ as a constant. This
indicates that considering the evolution of $\beta$ is very helpful for
reducing the tension between supernova and other cosmological observations.


title: A two-step model and the algorithm for recalling in recommender systems

abstract:
  When a user finds an interesting recommendation in a recommender system, the
user may want to recall related items recommended in the past to reconsider or
to enjoy them again. If the system can pick up such "recalled" items at each
user's request, it must deepen the user experience.
  We propose a model and the algorithm for such personalized "recalling" in
conventional recommender systems, which is an application of neural networks
for associative memory. In our model, the "recalled" items can reflect each
user's personality beyond naive similarities between items.


title: The Future of U.S. Particle Theory: Report of the DPF Theory Panel

abstract:
  This report summarizes the findings of the DPF Theory Panel which was formed
with a goal of understanding the scientific problems and opportunities of the
next decade, as well as the challenges involved in sustaining a first-class
program in theoretical particle physics research in the United States.


title:
Two-Qubit Gate Operation on Selected Nearest-Neighbor Neutral Atom
  Qubits

abstract:
  We have previously discussed the design of a neutral atom quantum computer
with an on-demand interaction [E. Hosseini Lapasar, et al., J. Phys. Soc. Jpn.
80, 114003 (2011)]. In this contribution, we propose an experimental method to
demonstrate a selective two-qubit gate operation that is less demanding than
our original proposal, although the gate operation is limited to act between
two neighboring atoms. We evaluate numerically the process of a two-qubit gate
operation that is applied to a selected pair of nearest-neighbor, trapped atoms
and we estimate the upper bound of the gate operation time and corresponding
gate fidelity. The proposed scheme is scalable and, though challenging, is
feasible with current experimental capabilities.


title:
Enumeration of weighted games with minimum and an analysis of voting
  power for bipartite complete games with minimum

abstract:
  This paper is a twofold contribution. First, it contributes to the problem of
enumerating some classes of simple games and in particular provides the number
of weighted games with minimum and the number of weighted games for the dual
class as well. Second, we focus on the special case of bipartite complete games
with minimum, and we compare and rank these games according to the behavior of
some efficient power indices of players of type 1 (or of type 2). The main
result of this second part establishes all allowable rankings of these games
when the Shapley-Shubik power index is used on players of type 1.


title:
New Sum Rule Determination of the Mass and Strangeness Content of the
  Nucleon

abstract:
  A new QCD calculation of the mass of the nucleon is presented. It makes use
of a polynomial kernel in the dispersion integrals tailored to practically
eliminate the contribution of the unknown 1=2+ and 1=2- continuum. This
approach avoids the arbitrariness and instability attached to the Borel kernel
used in previous sum rules calculations. Our method yields stable results for
the nucleon mass and coupling. For standard values of the condensates, the
prediction of the nucleon mass in the chiral limit is mN = (830+/-50)MeV. With
the pion-nucleon sigma-term given by chiral perturbation theory and the strange
sigma-term estimated by the Zweig rule we get mN = (990+/-50)MeV.


title: Tunneling in Nanoscale Devices

abstract:
  Theoretical treatments of tunneling in electronic devices are often based on
one-dimensional (1D) approximations. Here we show that for many nanoscale
devices, such as widely studied semiconductor gate-defined quantum dots, 1D
approximations yield an incorrect functional dependence on the tunneling
parameters (e.g., lead width and barrier length) and an incorrect magnitude for
the transport conductance. Remarkably, the physics of tunneling in 2D or 3D
also yields transport behavior that appears classical (like Ohm's law), even
deep in the quantum regime.


title:
Stationary random metrics on hierarchical graphs via $(\min,+)$-type
  recursive distributional equations

abstract:
  This paper is inspired by the problem of understanding in a mathematical
sense the Liouville quantum gravity on surfaces. Here we show how to define a
stationary random metric on self-similar spaces which are the limit of nice
finite graphs: these are the so-called hierarchical graphs. They possess a
well-defined level structure and any level is built using a simple recursion.
Stopping the construction at any finite level, we have a discrete random metric
space when we set the edges to have random length (using a multiplicative
cascade with fixed law $m$). We introduce a tool, the cut-off process, by means
of which one finds that renormalizing the sequence of metrics by an exponential
factor, they converge in law to a non-trivial metric on the limit space. Such
limit law is stationary, in the sense that glueing together a certain number of
copies of the random limit space, according to the combinatorics of the brick
graph, the obtained random metric has the same law when rescaled by a random
factor of law $m$. In other words, the stationary random metric is the solution
of a distributional equation. When the measure $m$ has continuous positive
density on $\mathbf{R}_+$, the stationary law is unique up to rescaling and any
other distribution tends to a rescaled stationary law under the iterations of
the hierarchical transformation. We also investigate topological and geometric
properties of the random space when $m$ is $\log$-normal, detecting a phase
transition influenced by the branching random walk associated to the
multiplicative cascade.


title:
Magnetization Characteristic of Ferromagnetic Thin Strip by Measuring
  Anisotropic Magnetoresistance and Ferromagnetic Resonance

abstract:
  The magnetization characteristic in a permalloy thin strip is investigated by
electrically measuring the anisotropic magnetoresistance and ferromagnetic
resonance in in-plane and out-of-plane configurations. Our results indicate
that the magnetization vector can rotate in the film plane as well as out of
the film plane by changing the intensity of external magnetic field of certain
direction. The magnetization characteristic can be explained by considering
demagnetization and magnetic anisotropy. Our method can be used to obtain the
demagnetization factor, saturated magnetic moment and the magnetic anisotropy.


title:
Charge Number Dependence of the Dephasing Rates of a Graphene Double
  Quantum Dot in a Circuit QED Architecture

abstract:
  We use an on-chip superconducting resonator as a sensitive meter to probe the
properties of graphene double quantum dots at microwave frequencies.
Specifically, we investigate the charge dephasing rates in a circuit quantum
electrodynamics architecture. The dephasing rates strongly depend on the number
of charges in the dots, and the variation has a period of four charges, over an
extended range of charge numbers. Although the exact mechanism of this fourfold
periodicity in dephasing rates is an open problem, our observations hint at the
fourfold degeneracy expected in graphene from its spin and valley degrees of
freedom.


title: Asynchronous Rumour Spreading in Social and Signed Topologies

abstract:
  In this paper, we present an experimental analysis of the asynchronous push &
pull rumour spreading protocol. This protocol is, to date, the best-performing
rumour spreading protocol for simple, scalable, and robust information
dissemination in distributed systems. We analyse the effect that multiple
parameters have on the protocol's performance, such as using memory to avoid
contacting the same neighbor twice in a row, varying the stopping criteria used
by nodes to decide when to stop spreading the rumour, employing more
sophisticated neighbor selection policies instead of the standard uniform
random choice, and others. Prior work has focused on either providing
theoretical upper bounds regarding the number of rounds needed to spread the
rumour to all nodes, or, proposes improvements by adjusting isolated
parameters. To our knowledge, our work is the first to study how multiple
parameters affect system behaviour both in isolation and combination and under
a wide range of values. Our analysis is based on experimental simulations using
real-world social network datasets, thus complementing prior theoretical work
to shed light on how the protocol behaves in practical, real-world systems. We
also study the behaviour of the protocol on a special type of social graph,
called signed networks (e.g., Slashdot and Epinions), whose links indicate
stronger trust relationships. Finally, through our detailed analysis, we
demonstrate how a few simple additions to the protocol can improve the total
time required to inform 100% of the nodes by a maximum of 99.69% and an average
of 82.37%.


title:
Correlation between Trion and Hole in Fermi Distribution in Process of
  Trion Photo-excitation in Doped QWs

abstract:
  The problem of correlation between a trion and a hole in the electron Fermi
distribution created in the process of trion photo-excitation in doped quantum
wells is under consideration. The hole in the Fermi distribution appears in the
trion creation process consisting of picking of the Fermi Sea electron up by
the exciton created in virtual state due to photon absorption. It is
demonstrated that the interaction results in formation of a correlated state of
the trion and the hole in the Fermi Sea. The state has excitation energy which
is less then trion energy minus Fermi energy that can be obtained as a lower
edge of trion excitation band using the simple energy conservation low in the
picture of independent trion and electrons. The wave function of the correlated
state is real and decreases with increase of distance between the trion and the
Fermi Sea hole, r, as 1/r^3/2. The wave function can be normalized to unity and
it corresponds to correlated state of the trion and Fermi Sea hole. In contrast
to this state, the states with excitation energies in the absorption band
between the trion energy and the trion energy minus Fermi energy have complex
wave functions that decrease as 1/r^1/2. These states correspond to the trion
and the Fermi Sea hole that is running away from the trion. The correlated
state described above is supposed to be responsible for the narrow trion
absorption line that was observed experimentally.


title:
Some non monotone schemes for time dependent Hamilton-Jacobi-Bellman
  equations in stochastic control

abstract:
  We introduce some approximation schemes for linear and fully non-linear
diffusion equations of Bellman-Isaacs type. Although they are not monotone one
can prove their convergence to the viscosity solution of the problem. Effective
implementation of these scheme is discussed and they are extensively tested.


title: About the role of scalars in a gauge theory

abstract:
  We consider a new effective symmetry that acts on a gauge invariant
Lagrangian. We show that the standard model after spontaneous symmetry
breakdown is invariant under this symmetry which identifies up to a scale
factor the gauge parameter with the elementary or composite scalars in the
theory. We discuss some of the consequences of this symmetry in the abelian and
non-abelian sectors of the standard model.


title: Physical conditions in star forming regions around S235

abstract:
  Gas density and temperature in star forming regions around Sh2-235 are
derived from ammonia line observations. This information is used to evaluate
formation scenarios and to determine evolutionary stages of the young embedded
clusters S235 East1, S235 East2, and S235 Central. We also estimate the gas
mass in the embedded clusters and its ratio to the stellar mass. S235 East1
appears to be less evolved than S235 East2 and S235 Central. In S235 East1 the
molecular gas mass exceeds that in the other clusters. Also, this cluster is
more embedded in the parent gas cloud than the other two. Comparison with a
theoretical model shows that the formation of these three clusters could have
been stimulated by the expansion of the Sh2-235 HII region (hereafter S235) via
a collect-and-collapse process, provided the density in the surrounding gas
exceeds $3\cdot10^3$ cm$^{-3}$, or via collapse of pre-existing clumps. The
expansion of S235 cannot be responsible for star formation in the southern S235
A-B region. However, formation of the massive stars in this region might have
been triggered by a large-scale supernova shock. Thus, triggered star formation
in the studied region may come in three varieties, namely collect-and-collapse
and collapse of pre-existing clumps, both initiated by expansion of the local
HII regions, and triggering by an external large-scale shock. We argue that the
C235 A HII region expands into a highly non-uniform medium with increasing
density. It is too young to trigger star formation in its vicinity by a
collect-and-collapse process. There is an age spread inside the S235 A-B
region. Massive stars in the S235 A-B region are considerably younger than
lower mass stars in the same area. This follows from the estimates of their
ages and the ages of associated HII regions.


title: Temporal mesonic correlators at NLO for any quark mass

abstract:
  We present NLO results for thermal imaginary-time correlators in the vector
and scalar channels as a function of the quark mass. The range of quark masses
for which a non-relativistic approximation works in the temperature range
considered is estimated, and charm quarks turn out to be a borderline case.
Comparing with simulation data from fine lattices, we find good agreement in
the vector channel but a substantial discrepancy in the scalar one. An
explanation for the discrepancy is suggested in terms of physics of the
quark-antiquark threshold region. Perturbative predictions for the bottom
scalar spectral function around the threshold are also briefly reviewed.


title: Single polymer gating of channels under a solvent gradient

abstract:
  We study the effect of a gradient of solvent quality on the coil-globule
transition for a polymer in a narrow pore. A simple self-attracting
self-avoiding walk model of a polymer in solution shows that the variation in
the strength of interaction across the pore leads the system to go from one
regime (good solvent) to the other (poor solvent) across the channel. This may
be thought analogous to thermophoresis, where the polymer goes from the hot
region to the cold region under the temperature gradient. The behavior of short
chains is studied using exact enumeration whilst the behavior of long chains is
studied using transfer matrix techniques. The distribution of the monomer
density across the layer suggests that a gate-like effect can be created, with
potential applications as a sensor.


title: The regularity of binomial edge ideals of graphs

abstract:
  We prove two recent conjectures on some upper bounds for the
Castelnuovo-Mumford regularity of the binomial edge ideals of some different
classes of graphs. We prove the conjecture of Matsuda and Murai for graphs
which has a cut edge or a simplicial vertex, and hence for chordal graphs. We
determine the regularity of the binomial edge ideal of the join of graphs in
terms of the regularity of the original graphs, and consequently prove the
conjecture of Matsuda and Murai for such a graph, and hence for complete
$t$-partite graphs. We also generalize some results of Schenzel and Zafar about
complete $t$-partite graphs. We also prove the conjecture due to the authors
for a class of chordal graphs.


title: A Couped-Qubit Tavis Cummings Scheme for Prolonging Quantum Coherence

abstract:
  Qubit-qubit interactions can significantly boost quantum coherence times for
Bell states. The coherence-time-enhancements are however not monotonic and
there exists a phase where further increasing the interaction is unhelpful. A
resonator in a suggested circuit QED type implementation of the
Tavis-Cummings(Dicke) model, is shown to shift this transition point depending
on the number of loaded photons. This allows the resonator to amplify the
coherence enhancements in certain regimes. The interactions also induce unusual
collapse and revival type behavior for the entanglement dynamics. A new and
exact open quantum systems formalism -- the quasi-Hamiltonians for the Dicke
model thus reveals how a Bell state in a resonator can be protected against
$1/f$ noise from randomly fluctuating two level systems. Simple circuit level
details are given for flux qubits.

categories: cond-mat.mes-hall cond-mat.supr-con physics.atm-clus physics.optics quant-ph


title:
Exponential growth of the vorticity gradient for the Euler equation on
  the torus

abstract:
  We prove that there are solutions to the Euler equation on the torus with
$C^{1,\alpha}$ vorticity and smooth except at one point such that the vorticity
gradient grows in $L^\infty$ at least exponentially as $t\to\infty$. The same
result is shown to hold for the vorticity Hessian and smooth solutions. Our
proofs use a version of a recent result by Kiselev and Sverak.


title:
A New Insight into Land Use Classification Based on Aggregated Mobile
  Phone Data

abstract:
  Land use classification is essential for urban planning. Urban land use types
can be differentiated either by their physical characteristics (such as
reflectivity and texture) or social functions. Remote sensing techniques have
been recognized as a vital method for urban land use classification because of
their ability to capture the physical characteristics of land use. Although
significant progress has been achieved in remote sensing methods designed for
urban land use classification, most techniques focus on physical
characteristics, whereas knowledge of social functions is not adequately used.
Owing to the wide usage of mobile phones, the activities of residents, which
can be retrieved from the mobile phone data, can be determined in order to
indicate the social function of land use. This could bring about the
opportunity to derive land use information from mobile phone data. To verify
the application of this new data source to urban land use classification, we
first construct a time series of aggregated mobile phone data to characterize
land use types. This time series is composed of two aspects: the hourly
relative pattern, and the total call volume. A semi-supervised fuzzy c-means
clustering approach is then applied to infer the land use types. The method is
validated using mobile phone data collected in Singapore. Land use is
determined with a detection rate of 58.03%. An analysis of the land use
classification results shows that the accuracy decreases as the heterogeneity
of land use increases, and increases as the density of cell phone towers
increases.


title:
Magnetic properties and electronic structure of Mn-Ni-Ga magnetic shape
  memory alloys

abstract:
  Influence of disorder, antisite defects, martensite transition and
compositional variation on the magnetic properties and electronic structure of
Mn$_2$NiGa and Mn$_{1+x}$Ni$_{2-x}$Ga magnetic shape memory alloys have been
studied by using full potential spin-polarized scalar relativistic
Korringa-Kohn-Rostocker (FP-SPRKKR) method. Mn$_2$NiGa is ferrimagnetic and its
total spin moment increases when disorder in the occupancy of Mn$_{\rm Ni}$ (Mn
atom in Ni position) is considered. The moment further increases when Mn-Ga
antisite defect[1] is included in the calculation. A reasonable estimate of
$T_C$ for Mn$_2$NiGa is obtained from the exchange parameters for the
disordered structure. Disorder influences the electronic structure of
Mn$_2$NiGa through overall broadening of the density of states and a decrease
in the exchange splitting. Inclusion of antisite defects marginally broaden the
minority spin partial DOS (PDOS), while the majority spin PDOS is hardly
affected. For Mn$_{1+x}$Ni$_{2-x}$Ga where 1$\geq$$x$$\geq$0, as $x$ decreases,
Mn$_{\rm Mn}$ moment increases while Mn$_{\rm Ni}$ moment decreases in both
austenite and martensite phases. For $x$$\geq$ 0.25, the total moment of the
martensite phase is smaller compared to the austenite phase, which indicates
possible occurrence of inverse magnetocaloric effect. We find that the
redistribution of Ni 3$d$- Mn$_{\rm Ni}$ 3$d$ minority spin electron states
close to the Fermi level is primarily responsible for the stability of the
martensite phase in Mn-Ni-Ga.


title:
Index map, $\sigma$-connections, and Connes-Chern character in the
  setting of twisted spectral triples

abstract:
  Twisted spectral triples are a twisting of the notion of spectral triple
aiming at dealing with some type III geometric situations. In the first part of
the paper, we give a geometric construction of the index map of a twisted
spectral triple in terms of $\sigma$-connections on finitely generated
projective modules. This makes it more transparent the analogy with the indices
of Dirac operators with coefficients in vector bundles. In the second part, we
give a direct construction of the Connes-Chern character of a twisted spectral,
both in the invertible and non-invertible cases. Combining these two parts we
obtain an analogue the Atiyah-Singer index formula for twisted spectral
triples.


title: Time varying ISI model for nonlinear interference noise

abstract:
  We show that the effect of nonlinear interference in WDM systems is
equivalent to slowly varying inter-symbol-interference (ISI), and hence its
cancellation can be carried out by means of adaptive linear filtering. We
characterize the ISI coefficients and discuss the potential gain following from
their cancellation.


title:
Very local interstellar spectra for galactic electrons, protons and
  helium

abstract:
  The local interstellar spectra (LIS) for cosmic rays at energies below about
30 GeV/nuc are increasingly obscured from view at Earth by solar modulation,
the lower the energy. These charged particles encounter significant changes in
the heliosphere, over an 11-year cycle, which include processes such as
convection, diffusion, adiabatic energy losses and gradient, curvature and
current sheet drifts. Particle drifts cause chargesign dependent modulation and
a 22-year cycle, adding complexity to determining the respective very LIS from
observations only at Earth. However, with measurements now made by the Voyager
1 spacecraft in the vicinity of the heliopause, it is possible to determine a
very LIS for galactic electrons between about 5 MeV and about 120 MeV. At these
low energies also galactic protons observed in the outer heliosphere had been
completely obscured by the so-call anomalous component which is accelerated
inside the heliosheath. Since August 2012, these anomalous cosmic rays are
substantially depleted at Voyager 1 so that also for cosmic ray ions it is now
possible to obtain a lower limit to their very LIS. Combining numerical
modelling of solar modulation with the accurate measurements by the PAMELA
mission and with Voyager observations, the lower limit of the very LIS for
electrons, protons and helium, and other ions, can be determined from about 5
MeV and above. These spectra are called heliopause spectra, considered to be
the lowest possible very LIS. Also from an astrophysics point of view, the
determination of what can be called a very LIS, not just an averaged galactic
spectrum, is encouraging. The mentioned aspects are discussed, focussing on a
comparison of recent heliospheric observations and corresponding solar
modulation modelling.


title:
A simple method to characterize the electrical and mechanical properties
  of micro-fibers

abstract:
  A procedure to characterize the electrical and mechanical properties of
micro-fibers is presented here. As the required equipment can be found in many
teaching laboratories, it can be carried out by physics and
mechanical/electrical engineering students. The electrical resistivity, mass
density and Young's modulus of carbon micro-fibers have been determined using
this procedure, obtaining values in very good agreement with the reference
values. The Young's modulus has been obtained by measuring the resonance
frequency of carbon fiber based cantilevers. In this way, one can avoid common
approaches based on tensile or bending tests which are difficult to implement
for microscale materials. Despite the simplicity of the experiments proposed
here, they can be used to trigger in the students interest on the electrical
and mechanical properties of microscale materials.


title: Molecular Weight Dependence of Excluded Volume Effects

abstract:
  Molecular weight dependence of excluded volume effects is examined. The
swollen-to-unperturbed coil transition point shifts to lower concentration
range with increasing molecular weight (Mw). It is shown that in the limit of
the infinite molecular weight, the excluded volume effects should vanish in all
concentration range, except for the only one point, Co = 0. Quite in contrast,
for short chains, the excluded volume effects never disappear even at the melt
state.


title:
Critical Magnetic Field Strength for Suppression of the
  Richtmyer-Meshkov Instability in Plasmas

abstract:
  The critical strength of a magnetic field required for the suppression of the
Richtmyer-Meshkov instability (RMI) is investigated numerically by using a
two-dimensional single-mode analysis. For the cases of MHD parallel shocks, the
RMI can be stabilized as a result of the extraction of vorticity from the
interface. A useful formula describing a critical condition for MHD RMI has
been introduced, and which is successfully confirmed by the direct numerical
simulations. The critical field strength is found to be largely depending on
the Mach number of the incident shock. If the shock is strong enough, even
low-$\beta$ plasmas can be subject to the growth of the RMI.


title: Accumulation of nonlinear interference noise in fiber-optic systems

abstract:
  Through a series of extensive system simulations we show that all of the
previously not understood discrepancies between the Gaussian noise (GN) model
and simulations can be attributed to the omission of an important, recently
reported, fourth-order noise (FON) term, that accounts for the statistical
dependencies within the spectrum of the interfering channel. We examine the
importance of the FON term as well as the dependence of NLIN on modulation
format with respect to link-length and number of spans. A computationally
efficient method for evaluating the FON contribution, as well as the overall
NLIN power is provided.


title:
Noncommutative Geometry and Conformal Geometry. III. Vafa-Witten
  Inequality and Poincar\'e Duality

abstract:
  This paper is the the third part of a series of paper whose aim is to use of
the framework of \emph{twisted spectral triples} to study conformal geometry
from a noncommutive geometric viewpoint. In this paper we reformulate the
inequality of Vafa-Witten \cite{VW:CMP84} in the setting of twisted spectral
triples. This involves a notion of Poincar\'e duality for twisted spectral
triples. Our main results have various consequences. In particular, we obtain a
version in conformal geometry of the original inequality of Vafa-Witten, in the
sense of an explicit control of the Vafa-Witten bound under conformal changes
of metric. This result has several noncommutative manifestations for conformal
deformations of ordinary spectral triples, spectral triples associated to
conformal weights on noncommutative tori, and spectral triples associated to
duals of torsion-free discrete cocompact subgroups satisfying the Baum-Connes
conjecture.


title: Practical Full Duplex Physical Layer Network Coding

abstract:
  We propose a practical network code for the wireless two-way relay channel
where all nodes communicate in full duplex (FD) mode. The physical layer
network coding (PNC) operation is applied with the FD operating nodes, reducing
the transmission time to a single time slot, hence doubling the spectral
efficiency when compared to classical PNC systems. In our system model, binary
phase shift keying modulated signals are transmitted over Rayleigh fading
channels. We derive the theoretical error rates at relay and end nodes
according to the maximum likelihood detection rule, in case of non-ideal
self-interference cancellation. Theoretical results are also verified via
simulations.


title: Dynamics of the Dicke model close to the classical limit

abstract:
  We study the dynamical properties of the Dicke model for increasing spin
length, as the system approaches the limit of a classical spin. First, we
describe the emergence of collective excitations above the groundstate that
converge to the coupled spin-oscillator oscillations found in the classical
limit. The corresponding Green functions reveal quantum dynamical signatures
close to the superradiant quantum phase transition. Second, we identify
signatures of classical quasi-periodic orbits in the quantum time evolution
using numerical time-propagation of the wave function. The resulting phase
space plots are compared to the classical trajectories. We complete our study
with the analysis of individual eigenstates close to the quasi-periodic orbits.


title:
Mode interference in quantum joint probabilities for multimode
  Bose-condensed systems

abstract:
  The method of defining quantum joint probabilities of two events is applied
to a multimode system of trapped Bose-condensed atoms. The coherent modes are
generated by modulating the trapping potential with an alternating field with a
frequency in resonance with a transition frequency between two coherent modes.
The system is subjected to nondestructive measurements randomly influencing the
phase difference of the modes. The joint probability of observing two events,
corresponding to the observation of two states, is calculated by employing the
channel-state duality. The interference term in the joint probability can arise
when the composite events form an entangled prospect and the system state is
also entangled. This interference is due to the uncertainty induced by
nondestructive measurements.


title: D^0-\bar{D}^0 Mixing and CP Violation in D^0-->K_{S}hh measurements

abstract:
  In these proceedings, we give a summary of the experimental results from
CLEO, Belle, BaBar and CDF collaboration about $D^0-\bar{D}^0$ mixing and CP
violation in self-conjugated-three-body decays $D^0\rightarrow K_S^0hh$ (where
$h$ can be $\pi$ or $K$). We report preliminary results of measurement of
$D^0-\bar{D}^0$ mixing and indirect CP violation in $D^0\rightarrow
K_S^0\pi^+\pi^-$ decays using full data sample collected by Belle detector at
KEKB asymmetric-energy $e^+e^-$ collider: give values for
$x=(0.56\pm0.19^{+0.03+0.06}_{-0.09-0.09})%$,
$y=(0.30\pm0.15^{+0.04+0.03}_{-0.05-0.06})%$,
$|q/p|=0.90^{+0.16+0.05+0.06}_{-0.15-0.04-0.05}$ and
$\arg(q/p)=-6\pm11^{+3+3}_{-3-4}(^o)$. We also report results of recent
measurement searching for CP violation in $D^0\rightarrow K_S^0\pi^+\pi^-$
decays by CDF collaboration using $6.0 fb^{-1}$ of data collected in $p\bar{p}$
collisions at Tevatron. The phase-space-integrated CP asymmetry is measured to
be $A_{CP}=(-0.05\pm0.57\pm0.54)%$ and the CP symmetry is also found to be
conserved in all individual intermediate contributions.


title: Atomistic spin model simulations of magnetic nanomaterials

abstract:
  Atomistic modelling of magnetic materials provides unprecedented detail about
the underlying physical processes that govern their macroscopic properties, and
allows the simulation of complex effects such as surface anisotropy, ultrafast
laser-induced spin dynamics, exchange bias, and mi- crostructural effects. Here
we present the key methods used in atomistic spin models which are then applied
to a range of magnetic problems. We detail the parallelisation strategies used
which enable the routine simulation of extended systems with full atomistic
resolution.


title: Step energies and equilibrium shape of strained monolayer islands

abstract:
  Using a simple atomistic model of anharmonic nearest-neighbors interaction,
we have calculated the step energies of strained hexagonal monolayer islands.
These have been found to decrease with the absolute value of the misfit due to
the strain relaxation at steps. The effect is significantly more pronounced in
the case of positive misfit owing to the stronger repulsive interatomic forces.
Furthermore, (111)-faceted steps are favored at positive misfit (compressed
islands) and, to a lesser extent, (100)-faceted steps at negative misfits
(tensile islands). The result is rationalized in terms of the different bonding
geometries at step edges and a comparison with experiments is included. Thus,
the equilibrium shape transforms from regular hexagons at zero misfit to
threefold symmetric hexagons with increasing misfit.


title: Testing a Dilaton Gravity Model using Nucleosynthesis

abstract:
  Big Bang Nucleosynthesis (BBN) offers one of the most strict evidences for
the Lambda-CDM cosmology at present, as well as the Cosmic Microwave Background
(CMB) radiation. In this work, our main aim is to present the outcomes of our
calculations related to primordial abundances of light elements, in the context
of higher dimensional steady-state universe model in the dilaton gravity. Our
results show that abundances of light elements (primordial D, 3He, 4He, T, 7Li)
are significantly different for some cases, and a comparison is given between a
particular dilaton gravity model and Lambda-CDM in the light of the
astrophysical observations.


title:
Rooted Tree Analysis for Order Conditions of Stochastic Runge-Kutta
  Methods for the Weak Approximation of Stochastic Differential Equations

abstract:
  A general class of stochastic Runge-Kutta methods for the weak approximation
of It\^o and Stratonovich stochastic differential equations with a
multi-dimensional Wiener process is introduced. Colored rooted trees are used
to derive an expansion of the solution process and of the approximation process
calculated with the stochastic Runge-Kutta method. A theorem on general order
conditions for the coefficients and the random variables of the stochastic
Runge-Kutta method is proved by rooted tree analysis. This theorem can be
applied for the derivation of stochastic Runge-Kutta methods converging with an
arbitrarily high order.


title: Studies of Charm Mixing and CPV

abstract:
  LHCb has collected the world's largest sample of charmed hadrons. This sample
is used to search for direct and indirect CP violation in charm and to measure
$D^0$ mixing parameters. Preliminary measurements from several decay modes are
presented, with complementary time-dependent and time-integrated analyses.


title: A dearth of dark matter in strong gravitational lenses

abstract:
  I show that the lensing masses of the SLACS sample of strong gravitational
lenses are consistent with the stellar masses determined from population
synthesis models using the Salpeter IMF. This is true in the context of both
General Relativity and modified Newtonian dynamics, and is in agreement with
the expectation of MOND that there should be little classical discrepancy
within the high surface brightness regions probed by strong gravitational
lensing. There is also dynamical evidence from this sample supporting the claim
that the mass-to-light ratio of the stellar component increases with the
velocity dispersion.


title: Anisotropic optical trapping of ultracold erbium atoms

abstract:
  Ultracold atoms confined in a dipole trap are submitted to a potential whose
depth is proportional to the real part of their dynamic dipole polarizability.
The atoms also experience photon scattering whose rate is proportional to the
imaginary part of their dynamic dipole polarizability. In this article we
calculate the complex dynamic dipole polarizability of ground-state erbium, a
rare-earth atom that was recently Bose-condensed. The polarizability is
calculated with the sum-over-state formula inherent to second-order
perturbation theory. The summation is performed on transition energies and
transition dipole moments from ground-state erbium, which are computed using
the Racah-Slater least-square fitting procedure provided by the Cowan codes.
This allows us to predict 9 unobserved odd-parity energy levels of total
angular momentum J=5, 6 and 7, in the range 25000-31000 cm-1 above the ground
state. Regarding the trapping potential, we find that ground-state erbium
essentially behaves like a spherically-symmetric atom, in spite of its large
electronic angular momentum. We also find a mostly isotropic van der Waals
interaction between two ground-state erbium atoms, characterized by a
coefficient C_6^{iso}=1760 a.u.. On the contrary, the photon-scattering rate
shows a pronounced anisotropy, since it strongly depends on the polarization of
the trapping light.


title:
Variational Bayes model averaging for graphon functions and motif
  frequencies inference in W-graph models

abstract:
  W-graph refers to a general class of random graph models that can be seen as
a random graph limit. It is characterized by both its graphon function and its
motif frequencies. In this paper, relying on an existing variational Bayes
algorithm for the stochastic block models along with the corresponding weights
for model averaging, we derive an estimate of the graphon function as an
average of stochastic block models with increasing number of blocks. In the
same framework, we derive the variational posterior frequency of any motif. A
simulation study and an illustration on a social network complete our work.


title:
An upper bound for the number of eigenvalues of non-selfadjoint
  Schr\"odinger operator

abstract:
  Estimates for the total multiplicity of eigenvalues for Schr\"odinger
operator are established in the case of compactly supported or exponentially
decreasing complex-valued potential.


title: Distance spectral radius of a tree with given diameter

abstract:
  For a connected graph, the distance spectral radius is the largest eigenvalue
of its distance matrix. In this paper, of all trees with both given order and
fixed diameter, the trees with the minimal distance spectral radius are
completely characterized.


title:
Shape-Preserving Accelerating Electromagnetic Wavepackets in Curved
  Space

abstract:
  We present shape-preserving spatially accelerating electromagnetic
wavepackets in curved space: wavepackets propagating along non-geodesic
trajectories while recovering their structure periodically. These wavepackets
are solutions to the paraxial and non-paraxial wave equation in curved space.
We analyze the dynamics of such beams propagating on surfaces of revolution,
and find solutions that carry finite power. These solutions propagate along a
variety of non-geodesic trajectories, reflecting the interplay between the
curvature of space and interference effects, with their intensity profile
becoming narrower (or broader) in a scaled self-similar fashion Finally, we
extend this concept to nonlinear accelerating beams in curved space supported
by the Kerr nonlinearity. Our study concentrates on optical settings, but the
underlying concepts directly relate to General Relativity.


title:
Generation of microwave radiation by nonlinear interaction of a
  high-power, high-repetition rate, 1064-nm laser in KTP crystals

abstract:
  We report measurements of microwave (RF) generation in the centimeter band
accomplished by irradiating a nonlinear KTiOPO$_4$ (KTP) crystal with a
home-made, infrared laser at $1064\,$nm as a result of optical rectification
(OR). The laser delivers pulse trains of duration up to $1\,\mu$s. Each train
consists of several high-intensity pulses at an adjustable repetition rate of
approximately $ 4.6\,$GHz. The duration of the generated RF pulses is
determined by that of the pulse trains. We have investigated both microwave-
and second harmonic (SHG) generation as a function of the laser intensity and
of the orientation of the laser polarization with respect to the
crystallographic axes of KTP.


title:
Markov dynamics on the dual object to the infinite-dimensional unitary
  group

abstract:
  These are notes for a mini-course of 3 lectures given at the St. Petersburg
School in Probability and Statistical Physics (June 2012). My aim was to
explain, on the example of a particular model, how ideas from the
representation theory of big groups can be applied in probabilistic problems.
  The material is based on the joint paper arXiv:1009.2029 by Alexei Borodin
and myself; a broader range of topics is surveyed in the lecture notes by
Alexei Borodin and Vadim Gorin arXiv:1212.3351.


title:
A few remarks on the octopus inequality and Aldous' spectral gap
  conjecture

abstract:
  A conjecture by D. Aldous, which can be formulated as a statement about the
first nontrivial eigenvalue of the Laplacian of certain Cayley graphs on the
symmetric group generated by transpositions, has been recently proven by
Caputo, Liggett and Richthammer. Their proof is a subtle combination of two
ingredients: a nonlinear mapping in the group algebra of the symmetric groups
which permits a proof by induction, and a quite hard estimate named the octopus
inequality. In this paper we present a simpler and more transparent proof of
the octopus inequality, which emerges naturally when looking at the Aldous'
conjecture from an algebraic perspective. We also show that the analogous of
the Aldous' conjecture, where the spectral gap is replaced by the Kazhdan
constant, does not hold in general.


title:
Modeling self-organization of nano-size vacancy clusters in stochastic
  systems subjected to irradiation

abstract:
  A study of the self-organization of vacancy clusters in irradiated materials
is presented. Using a continuum stochastic model we take into account dynamics
of point defects and their sinks with elastic interactions of vacancies.
Dynamics of vacancy clusters formation is studied analytically and numerically
under conditions related to irradiation in both reactors and accelerators. We
have shown a difference in patterning dynamics and studied the external noise
influence related to fluctuation in a defect production rate. Applying our
approach to pure nickel irradiated under different conditions we have shown
that vacancy clusters having a linear size 6 nm can arrange in statistical
periodic structure with nano-meter range. We have found that linear size of
vacancy clusters at accelerator conditions decreases down to 20%, whereas a
period of vacancy clusters reduces to 6.5%.


title: Cubic polynomials represented by norm forms

abstract:
  We show that for an irreducible cubic $f\in\mathbb Z[x]$ and a full norm form
$\mathbf N(x_1,\ldots,x_k)$ for a number field $K/\mathbb Q$ satisfying certain
hypotheses the variety $f(t)=\mathbf N(x_1,\ldots,x_k)\ne 0$ satisfies the
Hasse principle. Our proof uses sieve methods.


title: NLO WWZ production at the LHC

abstract:
  The tri-boson production is one of the key processes for the study of quartic
gauge couplings. Next-to-leading order (NLO) corrections are mandatory to
reduce theoretical uncertainties. In this study, the most up-to-date
predictions including NLO QCD and NLO EW corrections to the total cross section
and distributions of the WWZ production at the LHC are presented. We show that
the QCD correction is about 100% and the EW correction is of a few percent at
the total cross section level. The EW correction however becomes significant in
the high energy regime of the gauge boson transverse momentum distributions.


title:
Physics of non-steady state diffusion of lightweight atoms in a heavy
  atom matrix. Introducing an open-source tool for simulated-experiments in
  fluid mechanics

abstract:
  The practice-based learning methodologies offer to undergraduate professors
different ways to illustrate certain general physic principles. Traditional
experimental workbenches have been extensively used during decades for academic
lessons in order to complete theoretical dissertations or lectures, aiming at
assuring an adequate understanding. The high cost of materials and laboratory
equipment, the excessive preparation time, and the difficulty for carrying out
offsite-campus replications by students, are disadvantages that can discourage
of trying new kinds of experimental tasks. This paper gives insight of
simulated experiment possibilities through an open-source-based computational
suite in teaching fluid mechanics. Physics underlying diffusion of a light
specie in a heavier atom matrix, as function of time and position, were
explained to students as an example to teach them the Fick's Second Law
expression. We present a docent step-by-step programme, scheduled in three
sessions. The expected solution is firstly explained and then compared both to
a real case, by published results, and to the virtual-classroom experiment, by
resolving a differential equation with numerical schemes. Students were able to
make their own hypothesis, change input parameters, and contrasting their
initial assumptions.


title: Post-Planck Dark Energy Constraints

abstract:
  We constrain plausible dark energy models, parametrized by multiple candidate
equation of state, using the recently published Cosmic Microwave Background
(CMB) temperature anisotropy data from Planck together with the WMAP-9
low-$\ell$ polarization data and data from low redshift surveys. To circumvent
the limitations of any particular equation of state towards describing all
existing dark energy models, we work with three different equation of state
covering a broader class of dark energy models and, hence, provide more robust
and generic constraints on the dark energy properties. We show that a clear
tension exists between dark energy constraints from CMB and non-CMB
observations when one allows for dark energy models having both phantom and
non-phantom behavior; while CMB is more favorable to phantom models, the low-z
data prefers model with behavior close to a Cosmological Constant. Further, we
reconstruct the equation of state of dark energy as a function of redshift
using the results from combined CMB and non-CMB data and find that Cosmological
Constant lies outside the 1$\sigma$ band for multiple dark energy models
allowing phantom behavior. A considerable fine tuning is needed to keep models
with strict non-phantom history inside 2$\sigma$ allowed range. This result
might motivate one to construct phantom models of dark energy,which is
achievable in the presence of higher derivative operators as in string theory.
However, disallowing phantom behavior, based only on strong theoretical prior,
leads to both CMB and non-CMB datasets agree on the nature of dark energy, with
the mean equation of state being very close to the Cosmological Constant.
Finally, to illustrate the impact of additional dark energy parameters on other
cosmological parameters, we provide the cosmological parameter constraints for
different dark energy models.


title: Google Scholar Metrics evolution: an analysis according to languages

abstract:
  In November 2012 the Google Scholar Metrics (GSM) journal rankings were
updated, making it possible to compare bibliometric indicators in the 10
languages indexed and their stability with the April 2012 version. The h-index
and h 5 median of 1000 journals were analysed, comparing their averages,
maximum and minimum values and the correlation coefficient within rankings. The
bibliometric figures grew significantly. In just seven and a half months the h
index of the journals increased by 15% and the median h-index by 17%. This
growth was observed for all the bibliometric indicators analysed and for
practically every journal. However, we found significant differences in growth
rates depending on the language in which the journal is published. Moreover,
the journal rankings seem to be stable between April and November, reinforcing
the credibility of the data held by Google Scholar and the reliability of the
GSM journal rankings, despite the uncontrolled growth of Google Scholar. Based
on the findings of this study we suggest, firstly, that Google should upgrade
its rankings at least semiannually and, secondly, that the results should be
displayed in each ranking proportionally to the number of journals indexed by
language


title: Worldsheet Description of Exotic Five-brane with Two Gauged Isometries

abstract:
  We study the string worldsheet description of the background geometry of the
exotic $5^2_2$-brane where two isometries are gauged. This is an extension of
the gauged linear sigma model (GLSM) for the exotic $5^2_2$-brane with a single
gauged isometry. The new GLSM with two gauged isometries has only ${\mathcal
N}=(2,2)$ supersymmetry rather than ${\mathcal N}=(4,4)$ supersymmetry of the
original GLSM. This is caused by a conflict between two different $SU(2)_R$
associated with the two gauge symmetries. However, if we take a certain limit,
we can find the genuine string sigma model of the background geometry of the
exotic $5^2_2$-brane with ${\mathcal N}=(4,4)$ supersymmetry. We also
investigate the worldsheet instanton corrections to the background geometry of
the exotic $5^2_2$-brane. The worldsheet instanton corrections to the string
sigma model can be traced in terms of the two gauge fields in the new GLSM.
This new GLSM gives rise to a different feature of the quantum corrections from
the one in the GLSM with the single gauged isometry.


title:
Bright gamma-rays from betatron resonance acceleration in near critical
  density plasma

abstract:
  We show that electron betatron resonance acceleration by an ultra-intense
ultra-short laser pulse in a near critical density plasma works as a
high-brightness gamma-ray source. Compared with laser plasma X-ray sources in
under-dense plasma, near critical density plasma provides three benefits for
electron radiation: more radiation electrons, larger transverse amplitude, and
higher betatron oscillation frequency. Three-dimensional particle-in-cell
simulations show that, by using a 7.4J laser pulse, 8.3mJ radiation with
critical photon energy 1MeV is emitted. The critical photon energy $E_c$
increases with the incident laser energy %faster than a linear relation. $W_I$
as $E_c \propto W_I^{1.5}$, and the corresponding photon number is proportional
to $W_I$. A simple analytical synchrotron-like radiation model is built, which
can explain the simulation results.


title:
Unusual magneto-transport of YBa2Cu3O7-d films due to the interplay of
  anisotropy, random disorder and nanoscale periodic pinning

abstract:
  We study the general problem of a manifold of interacting elastic lines whose
spatial correlations are strongly affected by the competition between random
and ordered pinning. This is done through magneto-transport experiments with
YBa2Cu3O7-d thin films that contain a periodic vortex pinning array created via
masked ion irradiation, in addition to the native random pinning. The strong
field-matching effects we observe suggest the prevalence of periodic pinning,
and indicate that at the matching field each vortex line is bound to an
artificial pinning site. However, the vortex-glass transition dimensionality,
quasi-2D instead of the usual 3D, evidences reduced vortex-glass correlations
along the vortex line. This is also supported by an unusual angular dependence
of the magneto-resistance, which greatly differs from that of Bose-glass
systems. A quantitative analysis of the angular magnetoresistance allows us to
link this behaviour to the enhancement of the system anisotropy, a collateral
effect of the ion irradiation.


title:
The dichotomy spectrum for random dynamical systems and pitchfork
  bifurcations with additive noise

abstract:
  We develop the dichotomy spectrum for random dynamical system and demonstrate
its use in the characterization of pitchfork bifurcations for random dynamical
systems with additive noise.
  Crauel and Flandoli had shown earlier that adding noise to a system with a
deterministic pitchfork bifurcation yields a unique attracting random fixed
point with negative Lyapunov exponent throughout, thus "destroying" this
bifurcation. Indeed, we show that in this example the dynamics before and after
the underlying deterministic bifurcation point are topologically equivalent.
  However, in apparent paradox, we show that there is after all a qualitative
change in the random dynamics at the underlying deterministic bifurcation
point, characterized by the transition from a hyperbolic to a non-hyperbolic
dichotomy spectrum. This breakdown manifests itself also in the loss of uniform
attractivity, a loss of experimental observability of the Lyapunov exponent,
and a loss of equivalence under uniformly continuous topological conjugacies.


title: The Monge-Amp\`ere equation and its link to optimal transportation

abstract:
  We survey the (old and new) regularity theory for the Monge-Amp\`ere
equation, show its connection to optimal transportation, and describe the
regularity properties of a general class of Monge-Amp\`ere type equations
arising in that context.


title: The super-critical contact process has a spectral gap

abstract:
  We consider the super-critical contact process on $\mathbb{Z}^d$. It is known
that measures which dominate the upper invariant measure $\mu$ converge
exponentially fast to $\mu$. However, the same is not true for measures which
are below $\mu$, as the time to infect a large empty region is related to its
diameter. The result of this paper is the existence of a spectral gap in
$L^2(\mu)$, that is, the spectrum of the generator is empty inside an open
strip $\{z\in\mathbb{C}: -\lambda<\Im(z)<0\}$ of the complex plane. This is
equivalent to the fact that the variance of the semi-group of the contact
process decays exponentially fast. It is perhaps surprising that the existence
of the spectral gap has not been proven before. One of the reasons is that the
contact process is non-reversible, and hence many methods from spectral theory
are not applicable.


title:
Stochastic Taylor expansions for the expectation of functionals of
  diffusion processes

abstract:
  Stochastic Taylor expansions of the expectation of functionals applied to
diffusion processes which are solutions of stochastic differential equation
systems are introduced. Taylor formulas w.r.t. increments of the time are
presented for both, It\^o and Stratonovich stochastic differential equation
systems with multi-dimensional Wiener processes. Due to the very complex
formulas arising for higher order expansions, an advantageous graphical
representation by coloured trees is developed. The convergence of truncated
formulas is analyzed and estimates for the truncation error are calculated.
Finally, the stochastic Taylor formulas based on coloured trees turn out to be
a generalization of the deterministic Taylor formulas using plain trees as
recommended by Butcher for the solutions of ordinary differential equations.


title:
A Nystrom method for a boundary integral equation related to the
  Dirichlet problem on domains with corners

abstract:
  The authors consider the interior Dirichlet problem for Laplace's equation on
planar domains with corners. In order to approximate the solution of the
corresponding double layer boundary integral equation, they propose a numerical
method of Nystrom type, based on a Lobatto quadrature rule.The convergence and
stability of the method are proved and some numerical tests are included.


title:
Improving Mobile Video Streaming with Mobility Prediction and
  Prefetching in Integrated Cellular-WiFi Networks

abstract:
  We present and evaluate a procedure that utilizes mobility and throughput
prediction to prefetch video streaming data in integrated cellular and WiFi
networks. The effective integration of such heterogeneous wireless technologies
will be significant for supporting high performance and energy efficient video
streaming in ubiquitous networking environments. Our evaluation is based on
trace-driven simulation considering empirical measurements and shows how
various system parameters influence the performance, in terms of the number of
paused video frames and the energy consumption; these parameters include the
number of video streams, the mobile, WiFi, and ADSL backhaul throughput, and
the number of WiFi hotspots. Also, we assess the procedure's robustness to time
and throughput variability. Finally, we present our initial prototype that
implements the proposed approach.


title: Partial Probability and Kleene Logic

abstract:
  There are two main approach to probability, one of set-theoretic character
where probability is the measure of a set, and another one of linguistic
character where probability is the degree of confidence in a proposition. In
this work we give an unified algebraic treatment of these approaches through
the concept of valued lattice, obtaining as a by-product a translation between
them. Then we introduce the concept of partial valuation for DMF-algebras (De
Morgan algebras with a single fixed point for negation), giving an algebraic
setting for probability of partial events. We introduce the concept of partial
probability for propositions, substituting classical logic with Kleene's logic.
In this case too we give a translation between set-theoretic and linguistic
probability. Finally, we introduce the concept of conditional partial
probability and prove a weak form of Bayes's Theorem.


title:
Self-Organizing Mobility Robustness Optimization in LTE Networks with
  eICIC

abstract:
  We address the problem of Mobility Robustness Optimization (MRO) and describe
centralized Self Organizing Network (SON) solutions that can optimize
connected-mode mobility Key Performance Indicators (KPIs). Our solution extends
the earlier work of eICIC parameter optimization [7], to heterogeneous networks
with mobility, and outline methods of progressive complexity that optimize the
Retaining/Offloading Bias which are macro/pico views of Cell Individual Offset
parameters. Simulation results under real LTE network deployment assumptions of
a US metropolitan area demonstrate the effects of such solutions on the
mobility KPIs. To our knowledge, this solution is the first that demonstrates
the joint optimization of eICIC and MRO.


title:
Tunable electromagnetic chirality induced by graphene inclusions in
  multi-layered metamaterials

abstract:
  We theoretically investigate the electromagnetic response of a novel class of
multi-layered metamaterials obtained by alternating graphene sheets and
dielectric layers, the whole structure not exhibiting a plane of reflection
symmetry along the stacking direction. We show that the electromagnetic
response of the structure is characterized by a magneto-electric coupling
described by an effective chiral parameter. Exploiting the intrinsic tunability
of the graphene-light coupling, we prove that one can tune both the dielectric
and the chiral electromagnetic response by varying the graphene chemical
potential through external voltage gating.


title: Spherical collapse and halo mass function in the symmetron model

abstract:
  We study the gravitational clustering of spherically symmetric overdensities
and the statistics of the resulting dark matter halos in the "symmetron model",
in which a new long range force is mediated by a $Z_2$ symmetric scalar field.
Depending on the initial radius of the overdensity, we identify two distinct
regimes: for small initial radii the symmetron mediated force affects the
spherical collapse at all redshifts; for initial radii larger than some
critical size this force vanishes before collapse because of the symmetron
screening mechanism. In both cases overdensities collapse earlier than in the
$\Lambda$CDM and statistically tend to form more massive dark matter halos.
Regarding the halo-mass function of these objects, we observe order one
departures from standard $\Lambda$CDM predictions. The formalism developed here
can be easily applied to other models where fifth-forces participate to the
dynamics of the gravitational collapse.


title: Using higher-order contracts to model session types

abstract:
  Session types are used to describe and structure interactions between
independent processes in distributed systems. Higher-order types are needed in
order to properly structure delegation of responsibility between processes.
  In this paper we show that higher-order web-service contracts can be used to
provide a fully-abstract model of recursive higher-order session types. The
model is set-theoretic, in the sense that the meaning of a contract is given in
terms of the set of contracts with which it complies.
  The proof of full-abstraction depends on a novel notion of the complement of
a contract. This in turn gives rise to an alternative to the type duality
commonly used in systems for type-checking session types. We believe that the
notion of complement captures more faithfully the behavioural intuition
underlying type duality.


title:
Semi-analytical description of clumping factor and CMB free-free
  distortions from reionization

abstract:
  The density contrast of the Universe, parametrized in terms of the matter
power spectrum and its variance, can amplify the signal of the free-free
process in the plasma. The damping of fluctuations on scales smaller than the
DM particle free streaming scale corresponds to a suppression of the total
matter power spectrum on large wave numbers k. We derive the time evolution of
the variance of the matter power spectrum for various cosmological models and
parameters by numerically computing the power spectrum with a modified version
of the Boltzmann code CAMB, for different values of the cut-off parameter kmax.
Suitable analytical approximations of the numerical results are presented. We
then characterize the CMB free-free spectral distortion accounting for the
amplification effect coming from clumping factor. Indeed, the clumpiness,
associated to the density contrast of the intergalactic medium, increases at
decreasing redshift. The analysis is carried out for selected astrophysical and
phenomenological cosmological reionization histories, for which we evaluate the
impact of the clumping factor on the free-free distortion and discuss the
wavelength dependence of the predicted signal. Finally, we address a comparison
with other classes of unavoidable CMB spectral distortions and future
observational perspectives. While Comptonization from reionization is dominant
at high frequencies, the free-free signal predicted in the considered models
contributes to the distortion at a level of few (few tens) per cent at
frequencies below about 25 GHz (10 GHz) and represents the main signature below
about 4 GHz. The cosmological signal from the HI 21-cm background is found to
prevail over the free-free distortion in a restricted, model dependent
frequency window between about 0.1 and 0.2 GHz.


title: Precision Calculations in Supersymmetric Theories

abstract:
  In this review article we report on the newest developments in precision
calculations in supersymmetric theories. An important issue related to this
topic is the construction of a regularization scheme preserving simultaneously
gauge invariance and supersymmetry. In this context, we discuss in detail
dimensional reduction in component field formalism as it is currently the
preferred framework employed in the literature. Furthermore, we set special
emphasis on the application of multi-loop calculations to the analysis of gauge
coupling unification, the prediction of thelightest Higgs boson mass and the
computation of the hadronic Higgs production and decay rates in supersymmetric
models. Such precise theoretical calculations up to the fourth order in
perturbation theory are required in order to cope with the expected
experimental accuracy on the one hand, and to enable us to distinguish between
the predictions of the Standard Model and those of supersymmetric theories on
the other hand.


title: Null controllability of the heat equation using flatness

abstract:
  We derive in a direct and rather straightforward way the null controllability
of the N-dimensional heat equation in a bounded cylinder with boundary control
at one end of the cylinder. We use the so-called flatness approach, which
consists in parameterizing the solution and the control by the derivatives of a
"flat output". This yields an explicit control law achieving the exact steering
to zero. Replacing the involved series by partial sums we obtain a simple
numerical scheme for which we give explicit error bounds. Numerical experiments
demonstrate the relevance of the approach.


title:
On the numerical solution of a boundary integral equation for the
  exterior Neumann problem on domains with corners

abstract:
  The authors propose a Nystrom method to approximate the solution of a
boundary integral equation connected with the exterior Neumann problem for
Laplace's equation on planar domains with corners. They prove the convergence
and the stability of the method and show some numerical tests.


title: Stochastic Taylor Expansions for Functionals of Diffusion Processes

abstract:
  In the present paper, a stochastic Taylor expansion of some functional
applied to the solution process of an It\^o or Stratonovich stochastic
differential equation with a multi-dimensional driving Wiener process is given.
Therefore, the multi-colored rooted tree analysis is applied in order to obtain
a transparent representation of the expansion which is similar to the B-series
expansion for solutions of ordinary differential equations in the deterministic
setting. Further, some estimates for the mean--square and the mean truncation
errors are given.