title:
Rheology and dynamical heterogeneity in frictionless beads at jamming
  density

abstract:
  We investigate the rheological properties of an assembly of inelastic (but
frictionless) particles close to the jamming density using numerical
simulation, in which uniform steady states with a constant shear rate
$\dot\gamma$ is realized. The system behaves as a power-law fluid and the
relevant exponents are estimated; e.g., the shear stress is proportional to
$\dot\gamma^{1/\delta_S}$, where $1/\delta_S=0.64(2)$. It is also found that
the relaxation time $\tau$ and the correlation length $\xi$ of the velocity
increase obeying power laws: $\tau\sim\dot\gamma^{-\beta}$ and
$\xi\sim\dot\gamma^{-\alpha}$, where $\beta=0.27(3)$ and $\alpha=0.23(3)$.


title: On the Mullineux involution for Ariki-Koike algebras

abstract:
  This note is concerned with a natural generalization of the Mullineux
involution for Ariki-Koike algebras. Using a result of Fayers together with
previous results by the authors, we give an efficient algorithm for computing
this generalized Mullineux involution. Our algorithm notably does not involve
the determination of paths in affine crystals.


title:
Charge dynamics of doped holes in high Tc cuprates - A clue from optical
  conductivity

abstract:
  The charge dynamics in weakly hole doped high temperature superconductors is
studied in terms of the accurate numerical solution to a model of a single hole
interacting with a quantum lattice in an antiferromagnetic background, and
accurate far-infrared ellipsometry measurements. The experimentally observed
two electronic bands in the infrared spectrum can be identified in terms of the
interplay between the electron correlation and electron-phonon interaction
resolving the long standing mystery of the mid-infrared band.


title:
A New 100-GHz Band Front-End System with a Waveguide-Type
  Dual-Polarization Sideband-Separating SIS Receiver for the NRO 45-m Radio
  Telescope

abstract:
  We developed a waveguide-type dual-polarization sideband-separating SIS
receiver system of the 100-GHz band for the 45-m radio telescope at the
Nobeyama Radio Observatory, Japan. This receiver is composed of an ortho-mode
transducer and two sideband-separating SIS mixers, which are both based on the
waveguide technique. The receiver has four intermediate frequency bands of
4.0--8.0 GHz. Over the radio frequency range of 80--120 GHz, the
single-sideband receiver noise temperatures are 50--100 K and the image
rejection ratios are greater than 10 dB. We developed new matching optics for
the telescope beam as well as new IF chains for the four IF signals. The new
receiver system was installed in the telescope, and we successfully observed
the 12CO, 13CO and C18O emission lines simultaneously toward the Sagittarius B2
region to confirm the performance of the receiver system. The SSB noise
temperature of the system, including the atmosphere, became approximately half
of that of the previous receiver system. The Image Rejection Ratios (IRRs) of
the two 2SB mixers were calculated from the 12CO and HCO+ spectra from the W51
giant molecular cloud, resulting in > 20 dB for one polarization and > 12 dB
for the other polarization.


title: Dimension expanders

abstract:
  We show that there exists $k \in \bbn$ and $0 < \e \in\bbr$ such that for
every field $F$ of characteristic zero and for every $n \in \bbn$, there exists
explicitly given linear transformations $T_1,..., T_k: F^n \to F^n$ satisfying
the following:
  For every subspace $W$ of $F^n$ of dimension less or equal $\frac n2$, $
\dim(W+\suml^k_{i=1} T_iW) \ge (1+\e) \dim W$. This answers a question of Avi
Wigderson [W]. The case of fields of positive characteristic (and in particular
finite fields) is left open.


title: An introduction to L\'{e}vy processes with applications in finance

abstract:
  These lectures notes aim at introducing L\'{e}vy processes in an informal and
intuitive way, accessible to non-specialists in the field. In the first part,
we focus on the theory of L\'{e}vy processes. We analyze a `toy' example of a
L\'{e}vy process, viz. a L\'{e}vy jump-diffusion, which yet offers significant
insight into the distributional and path structure of a L\'{e}vy process. Then,
we present several important results about L\'{e}vy processes, such as infinite
divisibility and the L\'{e}vy-Khintchine formula, the L\'{e}vy-It\^{o}
decomposition, the It\^{o} formula for L\'{e}vy processes and Girsanov's
transformation. Some (sketches of) proofs are presented, still the majority of
proofs is omitted and the reader is referred to textbooks instead. In the
second part, we turn our attention to the applications of L\'{e}vy processes in
financial modeling and option pricing. We discuss how the price process of an
asset can be modeled using L\'{e}vy processes and give a brief account of
market incompleteness. Popular models in the literature are presented and
revisited from the point of view of L\'{e}vy processes, and we also discuss
three methods for pricing financial derivatives. Finally, some indicative
evidence from applications to market data is presented.


title:
Explicit demonstration of nonabelian anyon, braiding matrix and fusion
  rules in the Kitaev-type spin honeycomb lattice models

abstract:
  The exact solubility of the Kitaev-type spin honeycomb lattice model was
proved by means of a Majorana fermion representation or a Jordan-Wigner
transformation while the explicit form of the anyon in terms of Pauli matrices
became not transparent. The nonabelian statistics of anyons and the fusion
rules can only be expressed in indirect ways to Pauli matrices. We convert the
ground state and anyonic excitations back to the forms of Pauli matrices and
explicitly demonstrate the nonabelian anyonic statistics as well as the fusion
rules. These results may instruct the experimental realization of the
nonabelian anyons. We suggest a proof-in-principle experiment to verify the
existence of the nonabelian anyons in nature.


title:
Charge fluctuations and feedback effect in shot noise in a Y-terminal
  system

abstract:
  We investigate a dynamical Coulomb blockade effect and its role in the
enhancement of current-current correlations in a three-terminal device with a
multilevel splitter, as well as with two quantum dots. Spectral decomposition
analysis shows that in the Y-terminal system with a two level ideal splitter,
charge fluctuations at a level with a lowest outgoing tunneling rate are
responsible for a super-Poissonian shot noise and positive cross-correlations.
Interestingly, for larger source-drain voltages, electrons are transferred as
independent particles, when three levels participate in transport, and double
occupancy is allowed. We can explain compensation of the current correlations
as the interplay between different bunching and antibunching processes by
performing a spectral decomposition of the correlation functions for partial
currents flowing through various levels. In the system with two quantum dots
acting as a splitter, a long range feedback effect of fluctuating potentials
leads to the dynamical Coulomb blockade and an enhancement of shot noise.


title: Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11

abstract:
  The ongoing search for new superconductors has recently yielded a new family
of oxypnictides composed of alternating La_2O_{2-x}F_x and Fe_2As_2 layers
[1-4] with transition temperatures T_c of 25-28 K, which can be raised to 40-43
K by replacing La with Ce [5] or Sm [6] or to 52 K by replacing La with Nd and
Pr [7, 8]. Recent experiments and band structure calculations have suggested an
unconventional multiband superconductivity in the layers of paramagnetic Fe
ions, which would normally destroy superconductivity in the traditional
mechanism of the s-wave Cooper pairing. Here we report very high-field
resistance measurements up to 45T, which show a remarkable enhancement of the
upper critical fields B_c2 at low temperatures, as compared to those expected
from the already high slopes of dB_c2/dT ~ 2T/K near T_c . The deduced B_c2(0)
~ 63-65 T exceeds the paramagnetic limit, consistent with strong coupling and
important two-band effects in LaFeAsO_0.89F_0.11. We argue that oxypnictides
are emerging as a new class of high-field superconductors surpassing the B_c2
of Nb_3Sn, MgB_2, and the Chevrel phases and perhaps approaching the 100T field
benchmark of the high-T_c cuprates.


title: The False Dilemma: Bayesian vs. Frequentist

abstract:
  There are two main opposing schools of statistical reasoning, Frequentist and
Bayesian approaches. Until recent days, the frequentist or classical approach
has dominated the scientific research, but Bayesianism has reappeared with a
strong impulse that is starting to change the situation. Recently the
controversy about the primacy of one of the two approaches seems to be
unfinished at a philosophical level, but scientific practices are giving an
increasingly important position to the Bayesian approach. This paper eludes
philosophical debate to focus on the pragmatic point of view of scientists'
day-to-day practices, in which Bayesian methodology is very useful. Several
facts and operational values are described as the core-set for understanding
the change.


title:
Self Similar Renormalization Group Applied to Diffusion in non-Gaussian
  Potentials

abstract:
  We study the problem of the computation of the effective diffusion constant
of a Brownian particle diffusing in a random potential which is given by a
function $V(\phi)$ of a Gaussian field $\phi$. A self similar renormalization
group analysis is applied to a mathematically related problem of the effective
permeability of a random porous medium from which the diffusion constant of the
random potential problem can be extracted. This renormalization group approach
reproduces practically all known exact results in one and two dimensions. The
results are confronted with numerical simulations and we find that their
accuracy is good up to points well beyond the expected perturbative regime. The
results obtained are also tentatively applied to interacting particle systems
without disorder and we obtain expressions for the self-diffusion constant in
terms of the excess thermodynamic entropy. This result is of a form that has
commonly been used to fit the self diffusion constant in molecular dynamics
simulations.


title: Extrema de valeurs propres dans une classe conforme

abstract:
  Survey about extremum of eigenvalues of geometric operators within a
conformal class of a compact riemannian manifold.


title: Modular differential equations and null vectors

abstract:
  We show that every modular differential equation of a rational conformal
field theory comes from a null vector in the vacuum Verma module. We also
comment on the implications of this result for the consistency of the extremal
self-dual conformal field theories at c=24 k.


title: Photon plus Jet Cross Sections at the Tevatron

abstract:
  Photon plus jet production has been studied by the D0 and CDF experiments in
Run II of the Fermilab Tevatron Collider at a center of mass energy of
sqrt{s}=1.96 TeV. Measurements of the inclusive photon plus jet, di-photon and
photon plus b jet cross section are presented. They are based on integrated
luminosities between 0.2 fb^-1 and 1.1 fb^-1. The results are compared to
perturbative QCD calculations in various approximations.


title: 3D hydrodynamical simulations of the large scale structure of W50-SS433

abstract:
  We present 3D hydrodynamical simulations of a precessing jet propagating
inside a supernova remnant (SNR) shell, particularly applied to the W50-SS433
system in a search for the origin of its peculiar elongated morphology. Several
runs were carried out with different values for the mass loss rate of the jet,
the initial radius of the SNR, and the opening angle of the precession cone. We
found that our models successfully reproduce the scale and morphology of W50
when the opening angle of the jets is set to 10$\degr$ or if this angle
linearly varies with time. For these models, more realistic runs were made
considering that the remnant is expanding into an interstellar medium (ISM)
with an exponential density profile (as HI observations suggest). Taking into
account all these ingredients, the large scale morphology of the W50-SS 433
system, including the asymmetry between the lobes (formed by the jet-SNR
interaction), is well reproduced.


title: LISA parameter estimation of supermassive black holes

abstract:
  We study parameter estimation of supermassive black holes in the range
$10^5-10^8\Ms$ by LISA using the inspiral full post-Newtonian gravitational
waveforms, and we compare the results with those arising from the commonly used
restricted post-Newtonian approximation. The analysis shows that for
observations of the last year before merger, the inclusion of the higher
harmonics clearly improves the parameter estimation. We pay special attention
to the source location errors and we study the improvement on the percentage of
sources for which we could potentially identify electromagnetic counterparts.
We also show how the additional harmonics can help to mitigate the impact of
losing laser links during the mission.


title: Properly discontinuous actions on bounded domains

abstract:
  We give sufficient conditions for the quotient of a free, properly
discontinuous action on a bounded domain of holomorphy to be a Stein manifold
in terms of Poincar\'e series or limit sets for orbits. An immediate
consequence is that the quotient of any cyclic, free, properly discontinuous
action on the unit ball or the bidisc is Stein.


title:
Stability of superfluid and supersolid phases of dipolar bosons in
  optical lattices

abstract:
  We perform a stability analysis of superfluid (SF) and supersolid (SS) phases
of polarized dipolar bosons in two-dimensional optical lattices at high filling
factors and zero temperature, and obtain the phase boundaries between SF,
checkerboard SS (CSS), striped SS (SSS), and collapse. We show that the phase
diagram can be explored through the application of an external field and the
tuning of its direction with respect to the optical lattice plane. In
particular, we find a transition between the CSS and SSS phases.


title: Understanding the Unique Structural and Electronic Properties of SrFeO2

abstract:
  We report a first-principles study of SrFeO$_2$, an infinite-layer oxide with
Fe atoms in a perfect square-planar coordination down to essentially 0 K. Our
results reveal this striking behavior relies on the double occupation of the
3$d_{z^2}$ orbitals of high-spin Fe$^{2+}$. Such an electronic state results
from the hybridization of iron's 3$d_{z^2}$ and 4$s$ orbitals, which enables a
large reduction of the intra-atomic exchange splitting of the $z^2$ electrons.
The generality of the phenomenon is discussed.


title: Quantization of quasi-Lie bialgebras

abstract:
  We construct quantization functors of quasi-Lie bialgebras. We establish a
bijection between this set of quantization functors, modulo equivalence and
twist equivalence, and the set of quantization functors of Lie bialgebras,
modulo equivalence. This is based on the acyclicity of the kernel of the
natural morphism from the universal deformation complex of quasi-Lie bialgebras
to that of Lie bialgebras. The proof of this acyclicity consists in several
steps, ending up in the acyclicity of a complex related to free Lie algebras,
namely, the universal version of the Lie algebra cohomology complex of a Lie
algebra in its enveloping algebra, viewed as the left regular module. Using the
same arguments, we also prove the compatibility of quantization functors of
quasi-Lie bialgebras with twists, which allows us to recover our earlier
results on compatibility of quantization functors with twists in the case of
Lie bialgebras.


title:
Multistable Solitons in Higher-Dimensional Cubic-Quintic Nonlinear
  Schroedinger Lattices

abstract:
  We study the existence, stability, and mobility of fundamental discrete
solitons in two- and three-dimensional nonlinear Schroedinger lattices with a
combination of cubic self-focusing and quintic self-defocusing onsite
nonlinearities. Several species of stationary solutions are constructed, and
bifurcations linking their families are investigated using parameter
continuation starting from the anti-continuum limit, and also with the help of
a variational approximation. In particular, a species of hybrid solitons,
intermediate between the site- and bond-centered types of the localized states
(with no counterpart in the 1D model), is analyzed in 2D and 3D lattices. We
also discuss the mobility of multi-dimensional discrete solitons that can be
set in motion by lending them kinetic energy exceeding the appropriately
crafted Peierls-Nabarro barrier; however, they eventually come to a halt, due
to radiation loss.


title:
Revised bolometric corrections and interstellar extinction coefficients
  for the ACS and WFPC2 photometric systems

abstract:
  We present extensive tables of bolometric corrections and interstellar
extinction coefficients for the WFPC2 and ACS (both WFC and HRC) photometric
systems. They are derived from synthetic photometry applied to a database of
spectral energy distributions covering a large range of effective temperatures,
surface gravity, and metal content. Carbon stars are also considered. The
zero-points take into consideration the new high-accuracy Vega fluxes from
Bohlin. These tables are employed to transform Padova isochrones into WFPC2 and
ACS photometric systems using interstellar extinction coefficients on a
star-to-star basis. All data are available either in tabular form or via an
interactive web interface in the case of the isochrones. Preliminary tables for
the WFC3 camera are also included in the database.


title: Fingerprint for Network Topologies

abstract:
  A network's topology information can be given as an adjacency matrix. The
bitmap of sorted adjacency matrix(BOSAM) is a network visualisation tool which
can emphasise different network structures by just looking at reordered
adjacent matrixes. A BOSAM picture resembles the shape of a flower and is
characterised by a series of 'leaves'. Here we show and mathematically prove
that for most networks, there is a self-similar relation between the envelope
of the BOSAM leaves. This self-similar property allows us to use a single
envelope to predict all other envelopes and therefore reconstruct the outline
of a network's BOSAM picture. We analogise the BOSAM envelope to human's
fingerprint as they share a number of common features, e.g. both are simple,
easy to obtain, and strongly characteristic encoding essential information for
identification.


title:
Pressure-temperature Phase Diagram of Polycrystalline UCoGe Studied by
  Resistivity Measurement

abstract:
  Recently, coexistence of ferromagnetism (T_Curie = 2.8K) and
superconductivity (T_sc = 0.8K) has been reported in UCoGe, a compound close to
a ferromagnetic instability at ambient pressure P. Here we present resistivity
measurements under pressure on a UCoGe polycrystal. The phase diagram obtained
from resistivity measurements on a polycrystalline sample is found to be
qualitatively different to those of all other ferromagnetic superconductors. By
applying high pressure, ferromagnetism is suppressed at a rate of 1.4 K/GPa. No
indication of ferromagnetic order has been observed above P ~ 1GPa. The
resistive superconducting transition is, however, quite stable in temperature
and persists up to the highest measured pressure of about 2.4GPa.
Superconductivity would therefore appear also in the paramagnetic phase.
However, the appearance of superconductivity seems to change at a
characteristic pressure P* ~ 0.8GPa. Close to a ferromagnetic instability, the
homogeneity of the sample can influence strongly the electronic and magnetic
properties and therefore bulk phase transitions may differ from the
determination by resistivity measurements.


title:
Bohmian approach to spin-dependent time of arrival for particles in a
  uniform field and for particles passing through a barrier

abstract:
  It is known that Lorentz covariance fixes uniquely the current and the
associated guidance law in the trajectory interpretation of quantum mechanics
for spin-1/2 particles. In the nonrelativistic domain this implies a guidance
law for electrons which differs by an additional spin-dependent term from the
one originally proposed by de Broglie and Bohm. Although the additional term in
the guidance equation may not be detectable in the quantum measurements derived
solely from the probability density $\rho$, it plays a role in the case of
arrival-time measurements. In this paper we compute the arrival time
distribution and the mean arrival time at a given location, with and without
the spin contribution, for two problems: 1) a symmetrical Gaussian packet in a
uniform field and 2) a symmetrical Gaussian packet passing through a 1D
barrier. Using the Runge-Kutta method for integration of the guidance law,
Bohmian paths of these problems are also computed.


title: Clustering environment of BL Lac object RGB 1745+398

abstract:
  The BL Lac object RGB 1745+398 lies in an environment that makes it possible
to study the cluster around it more deeply than the environments of other BL
Lac objects. The cluster centered on the BL Lac works as a strong gravitational
lens, forming a large arc around itself. The aim of this paper is to study the
environment and characteristics of this object more accurately than the
environments of other BL Lac objects have been before.We measured the redshifts
of galaxies in the cluster from the absorption lines in their spectra. The
velocity dispersion was then obtained from the redshifts. The gravitational
lensing was used for measuring the mass at the center of the cluster. The mass
of the whole cluster could then be estimated using the softened isothermal
sphere mass distribution. Finally, the richness of the cluster was determined
by counting the number of galaxies near the BL Lac object and obtaining the
galaxy-BL Lac spatial covariance function, $B_{gb}$. The redshifts of nine
galaxies in the field were measured to be near the redshift of the BL Lac
object, confirming the presence of a cluster. The average redshift of the
cluster is 0.268, and the velocity dispersion $(470^{+190}_{-110})$ km
s$^{-1}$. The mass of the cluster is $M_{500}=(4^{+3}_{-2})\times10^{14}
M_{\sun}$ which implies a rather massive cluster. The richness measurement also
suggests that this is a rich cluster: the result for covariance function is
$B_{gb}=(600\pm200)$ Mpc$^{1.77}$, which corresponds to Abell richness class 1
and which is consistent with the mass and velocity dispersion of the cluster.


title:
The Weak Coupling Spectrum around Isolated Vacua in N=4 Super Yang-Mills
  on T^3 with any Gauge Group

abstract:
  The moduli space of flat connections for maximally supersymmetric Yang-Mills
theories, in a space-time of the form T^3xR, contains isolated points,
corresponding to normalizable zero energy states, for certain simple gauge
groups G. We consider the low energy effective field theories in the weak
coupling limit supported on such isolated points and find that when quantized
they consist of an infinite set of harmonic oscillators whose angular
frequencies are completely determined by the Lie algebra of G. We then proceed
to find the isolated flat connections for all simple G and subsequently specify
the corresponding effective field theories.


title:
Spin dependent impurity effects in the 2D frustrated magnetism of
  NiGa$_2$S$_4$

abstract:
  Impurity effects on the triangular antiferromagnets Ni$_{1-x}M_x$Ga$_2$S$_4$
($M=$ Mn, Fe, Co and Zn) are studied. The 2D frozen spin-disordered state of
NiGa$_2$S$_4$ is stable against the substitution of Zn$^{2+}$ ($S=0$) and
Heisenberg Fe$^{2+}$ ($S=2$) spins, and exhibits a $T^2$-dependent magnetic
specific heat, scaled by the Weiss temperature. In contrast, the substitutions
with Co$^{2+}$ ($S=3/2$) spin with Ising-like anisotropy and Heisenberg
Mn$^{2+}$ ($S=5/2$) spin induce a conventional spin glass phase. From these
comparisons, it is suggested that integer size of Heisenberg spins is important
to stabilize the 2D coherent behavior observed in the frozen spin-disordered
state.


title:
Interaction of a two-level atom with a classical field in the context of
  Bohmian mechanics

abstract:
  We discuss Bohmian paths of the two-level atoms moving in a waveguide through
an external resonance-producing field, perpendicular to the waveguide, and
localized in a region of finite diameter. The time spent by a particle in a
potential region is not well-defined in the standard quantum mechanics, but it
is well-defined in the Bohmian mechanics. Bohm's theory is used for calculating
the average time spent by a transmitted particle inside the field region and
the arrival-time distributions at the edges of the field region. Using the
Runge-Kutta method for the integration of the guidance law, some Bohmian
trajectories were also calculated. Numerical results are presented for the
special case of a Gaussian wave packet.


title:
Distributed Consensus over Wireless Sensor Networks Affected by
  Multipath Fading

abstract:
  The design of sensor networks capable of reaching a consensus on a globally
optimal decision test, without the need for a fusion center, is a problem that
has received considerable attention in the last years. Many consensus
algorithms have been proposed, with convergence conditions depending on the
graph describing the interaction among the nodes. In most works, the graph is
undirected and there are no propagation delays. Only recently, the analysis has
been extended to consensus algorithms incorporating propagation delays. In this
work, we propose a consensus algorithm able to converge to a globally optimal
decision statistic, using a wideband wireless network, governed by a fairly
simple MAC mechanism, where each link is a multipath, frequency-selective,
channel. The main contribution of the paper is to derive necessary and
sufficient conditions on the network topology and sufficient conditions on the
channel transfer functions guaranteeing the exponential convergence of the
consensus algorithm to a globally optimal decision value, for any bounded delay
condition.


title: Extreme Horizontal Branch Stars

abstract:
  A review is presented on the properties, origin and evolutionary links of hot
subluminous stars which are generally believed to be extreme Horizontal Branch
stars or closely related objects. Amongst the field stars a large fraction of
sdBs are found to reside in close binaries. The companions are predominantly
white dwarfs, or low mass main sequence stars. Systems with sufficiently
massive WD companions may qualify as SN Ia progenitors. Recently evidence has
been found that the masses of some unseen companions might exceed the
Chandrasekhar mass, hence they must be neutron stars or black holes. Even a
planet has recently been detected orbiting the pulsating sdB star V391 Peg.
Quite to the opposite, in globular clusters, only very few sdB binaries are
found indicating that the dominant sdB formation processes is different in a
dense environment. Binary population synthesis models identify three formation
channels, (i) stable Roche lobe overflow, (ii) one or two common envelope
ejection phases and (iii) the merger of two helium white dwarfs. The latter
channel may explain the properties of the He-enriched sdO stars because their
binary fraction is lower than that of the sdBs by a factor of ten or more.
Pulsating subluminous B (sdB) stars play an important role for asteroseismology
as this technique has already led to mass determinations for a handful of
stars. A unique hyper-velocity sdO star moving so fast that it is unbound to
the Galaxy has probably been ejected by the super-massive black hole in the
Galactic centre. (abridged)


title:
Experimental demonstration of frequency-degenerate bright EPR beams with
  a self-phase-locked optical parametric oscillator

abstract:
  We report the first experimental observation of bright EPR beams produced by
a type-II optical parametric oscillator operating above threshold at frequency
degeneracy. The degenerate operation is obtained by introducing a birefringent
plate inside the cavity resulting in phase locking. After filtering the pump
noise, which plays a critical role, continuous-variable EPR correlations
between the orthogonally polarized signal and idler beams are demonstrated.


title:
Parity-violating nucleon-nucleon interactions: what can we learn from
  nuclear anapole moments?

abstract:
  Knowledge about parity-violating effects both from theory and experiment is
reviewed. Further information that could be obtained from measurements of
nuclear anapole moments is discussed.


title: Nonparametric Statistical Inference for Ergodic Processes

abstract:
  In this work a method for statistical analysis of time series is proposed,
which is used to obtain solutions to some classical problems of mathematical
statistics under the only assumption that the process generating the data is
stationary ergodic. Namely, three problems are considered: goodness-of-fit (or
identity) testing, process classification, and the change point problem. For
each of the problems a test is constructed that is asymptotically accurate for
the case when the data is generated by stationary ergodic processes. The tests
are based on empirical estimates of distributional distance.


title: Multi-mode bosonic Gaussian channels

abstract:
  A complete analysis of multi-mode bosonic Gaussian channels is proposed. We
clarify the structure of unitary dilations of general Gaussian channels
involving any number of bosonic modes and present a normal form. The maximum
number of auxiliary modes that is needed is identified, including all rank
deficient cases, and the specific role of additive classical noise is
highlighted. By using this analysis, we derive a canonical matrix form of the
noisy evolution of n-mode bosonic Gaussian channels and of their weak
complementary counterparts, based on a recent generalization of the normal mode
decomposition for non-symmetric or locality constrained situations. It allows
us to simplify the weak-degradability classification. Moreover, we investigate
the structure of some singular multi-mode channels, like the additive classical
noise channel that can be used to decompose a noisy channel in terms of a less
noisy one in order to find new sets of maps with zero quantum capacity.
Finally, the two-mode case is analyzed in detail. By exploiting the composition
rules of two-mode maps and the fact that anti-degradable channels cannot be
used to transfer quantum information, we identify sets of two-mode bosonic
channels with zero capacity.


title: Remarks on Superstring amplitudes in higher genus

abstract:
  Very recently, Grushevsky continued D'Hoker and Phong's program of finding
the chiral superstring measure from first principles by constructing modular
forms satisfying certain factorization constraints. He has proposed an ansatz
in genus 4 and conjectured a possible formula for the superstring measure in
any genus, subject to the condition that certain modular forms admit
holomorphic roots. In this note we want to give some evidence that Grushevsky's
approach seems to be very fruitful.


title: Two-point functions with an invariant Planck scale and thermal effects

abstract:
  Nonlinear deformations of relativistic symmetries at the Planck scale are
usually addressed in terms of modified dispersion relations. We explore here an
alternative route by directly deforming the two-point functions of an
underlying field theory. The proposed deformations depend on a length parameter
(Planck length) and preserve the basic symmetries of the corresponding theory.
We also study the physical consequences implied by these modifications at the
Planck scale by analyzing the response function of an accelerated detector in
Minkowski space, an inertial one in de Sitter space, and also in a black hole
spacetime.


title: The Ionization of Accretion Flows in High Mass Star Formation: W51e2

abstract:
  Previous observations show that the hypercompact HII region W51e2 is
surrounded by a massive molecular accretion flow centered on the HII region.
New observations of the H53alpha radio recombination line made with the VLA at
0.45 arc second angular resolution show a velocity gradient in the ionized gas
within the HII region of > 500 kms-1 pc-1 comparable to the velocity gradient
seen in the molecular accretion flow. New CO line observations made with the
SMA at arc second angular resolution detect a molecular bipolar outflow
immediately around the W51e2 HII region and extending along the axis of
rotation of the molecular flow. These observations are consistent with an
evolutionary phase for high mass star formation in which a newly formed massive
star first begins to ionize its surroundings including its own accretion flow.


title: Flexoelectricity and competition of time scales in electroconvection

abstract:
  Novel behavior in electroconvection (EC) has been detected in nematic liquid
crystals (NLCs) under the condition of comparable timescales of the director
relaxation and the period of the driving ac voltage. The studied NLCs exhibit
standard EC (s-EC) at the onset of the instability, except one compound in
which nonstandard EC (ns-EC) has been detected. In the relevant frequency
region, the threshold voltage for conductive s-EC bends down considerably,
while for dielectric s-EC it bends up strongly with the decrease of the driving
frequency. We show that inclusion of the flexoelectric effect into the
theoretical description of conductive s-EC leads to quantitative agreement,
while for dielectric s-EC a qualitative agreement is achieved. The frequency
dependence of the threshold voltage for ns-EC strongly resembles that of the
dielectric s-EC.


title: Chemical trees minimizing energy and Hosoya index

abstract:
  The energy of a molecular graph is a popular parameter that is defined as the
sum of the absolute values of a graph's eigenvalues. It is well known that the
energy is related to the matching polynomial and thus also to the Hosoya index
via a certain Coulson integral. Trees minimizing the energy under various
additional conditions have been determined in the past, e.g., trees with a
given diameter or trees with a perfect matching. However, it is quite a natural
problem to minimize the energy of trees with bounded maximum degree--clearly,
the case of maximum degree 4 (so-called chemical trees) is the most important
one. We will show that the trees with given maximum degree that minimize the
energy are the same that have been shown previously to minimize the Hosoya
index and maximize the Merrifield-Simmons index, thus also proving a conjecture
due to Fischermann et al. Finally, we show that the minimal energy grows
linearly with the size of the trees, with explicitly computable growth
constants that only depend on the maximum degree.


title: Singular integrals on Sierpinski gaskets

abstract:
  We construct a class of singular integral operators associated with
homogeneous Calder\'{o}n-Zygmund standard kernels on $d$-dimensional, $d <1$,
Sierpinski gaskets $E_d$. These operators are bounded in $L^2(\mu_d)$ and their
principal values diverge $\mu_d$ almost everywhere, where $\mu_d$ is the
natural (d-dimensional) measure on $E_d$.


title:
Directed porosity on conformal iterated function systems and weak
  convergence of singular integrals

abstract:
  The aim of the present paper is twofold. We study directed porosity in
connection with conformal iterated function systems (CIFS) and with singular
integrals. We prove that limit sets of finite CIFS are porous in a stronger
sense than already known. Furthermore we use directed porosity to establish
that truncated singular integral operators, with respect to general Radon
measures $\mu$ and kernels $K$, converge weakly in some dense subspaces of
$L^2(\mu)$ when the support of $\mu$ belongs to a broad family of sets. This
class contains many fractal sets like CIFS's limit sets.


title:
Analytical Approach to the One-Dimensional Disordered Exclusion Process
  with Open Boundaries and Random Sequential Dynamics

abstract:
  A one dimensional disordered particle hopping rate asymmetric exclusion
process (ASEP) with open boundaries and a random sequential dynamics is studied
analytically. Combining the exact results of the steady states in the pure case
with a perturbative mean field-like approach the broken particle-hole symmetry
is highlighted and the phase diagram is studied in the parameter space
$(\alpha,\beta)$, where $\alpha$ and $\beta$ represent respectively the
injection rate and the extraction rate of particles. The model displays, as in
the pure case, high-density, low-density and maximum-current phases. All
critical lines are determined analytically showing that the high-density
low-density first order phase transition occurs at $\alpha \neq \beta$. We show
that the maximum-current phase extends its stability region as the disorder is
increased and the usual $1/\sqrt{\ell}$-decay of the density profile in this
phase is universal. Assuming that some exact results for the disordered model
on a ring hold for a system with open boundaries, we derive some analytical
results for platoon phase transition within the low-density phase and we give
an analytical expression of its corresponding critical injection rate
$\alpha^*$. As it was observed numerically$^{(19)}$, we show that the quenched
disorder induces a cusp in the current-density relation at maximum flow in a
certain region of parameter space and determine the analytical expression of
its slope. The results of numerical simulations we develop agree with the
analytical ones.


title: Quantum MERA Channels

abstract:
  Tensor networks representations of many-body quantum systems can be described
in terms of quantum channels. We focus on channels associated with the
Multi-scale Entanglement Renormalization Ansatz (MERA) tensor network that has
been recently introduced to efficiently describe critical systems. Our approach
allows us to compute the MERA correspondent to the thermodynamic limit of a
critical system introducing a transfer matrix formalism, and to relate the
system critical exponents to the convergence rates of the associated channels.


title: The incidence of mid-infrared excesses in G and K giants

abstract:
  Using photometric data from the 2MASS and GLIMPSE catalogues, I investigate
the incidence of mid-infrared excesses (~10 microns) of G and K stars of
luminosity class III. In order to obtain a large sample size, stars are
selected using a near-IR colour-magnitude diagram. Sources which are candidates
for showing mid-IR excess are carefully examined and modelled to determined
whether they are likely to be G/K giants. It is found that mid-IR excesses are
present at a level of (1.8 +/- 0.4) x 10^-3. While the origin of these excesses
remains uncertain, it is plausible that they arise from debris discs around
these stars. I note that the measured incidence is consistent with a scenario
in which dust lifetimes in debris discs are determined by Poynting-Robertson
drag rather than by collisions.


title: Schwinger-Fronsdal Theory of Abelian Tensor Gauge Fields

abstract:
  This review is devoted to the Schwinger and Fronsdal theory of Abelian tensor
gauge fields. The theory describes the propagation of free massless gauge
bosons of integer helicities and their interaction with external currents.
Self-consistency of its equations requires only the traceless part of the
current divergence to vanish. The essence of the theory is given by the fact
that this weaker current conservation is enough to guarantee the unitarity of
the theory. Physically this means that only waves with transverse polarizations
are propagating very far from the sources. The question whether such currents
exist should be answered by a fully interacting theory. We also suggest an
equivalent representation of the corresponding action.


title: Interaction-free measurements with superconducting qubits

abstract:
  An interaction-free measurement protocol is described for a quantum circuit
consisting of a superconducting qubit and a read-out Josephson junction. By
measuring the state of the qubit one can ascertain the presence of a current
pulse through the circuit at a previous time without any energy exchange
between the qubit and the pulse.


title: Bayesian Optimisation Algorithm for Nurse Scheduling

abstract:
  Our research has shown that schedules can be built mimicking a human
scheduler by using a set of rules that involve domain knowledge. This chapter
presents a Bayesian Optimization Algorithm (BOA) for the nurse scheduling
problem that chooses such suitable scheduling rules from a set for each nurses
assignment. Based on the idea of using probabilistic models, the BOA builds a
Bayesian network for the set of promising solutions and samples these networks
to generate new candidate solutions. Computational results from 52 real data
instances demonstrate the success of this approach. It is also suggested that
the learning mechanism in the proposed algorithm may be suitable for other
scheduling problems.


title: A special case of the $\Gamma_{00}$ conjecture

abstract:
  In this paper we prove the $\Gamma_{00}$ conjecture of van Geemen and van der
Geer, under the additional assumption that the matrix of coefficients of the
tangent has rank at most 2. This assumption is satisfied by Jacobians, and thus
our result gives a characterization of the locus of Jacobians among all
principally polarized abelian varieties.
  The proof is by reduction to the (stronger version of the) characterization
of Jacobians by semidegenerate trisecants, i.e. by the existence of lines
tangent to the Kummer variety at one point and intersecting it in another,
proven by Krichever in the course of his proof of the Welters' trisecant
conjecture.


title: Partial Translation Algebras for Trees

abstract:
  In arXiv:math/0603621 we introduced the notion of a partial translation
$C^*$-algebra for a discrete metric space. Here we demonstrate that several
important classical $C^*$-algebras and extensions arise naturally by
considering partial translation algebras associated with subspaces of trees.


title:
Harmonic Inpainting of the Cosmic Microwave Background Sky: Formulation
  and Error Estimate

abstract:
  We develop a new interpolation scheme, based on harmonic inpainting, for
reconstructing the cosmic microwave background temperature data within the
Galaxy mask from the data outside the mask. We find that, for scale-invariant
isotropic random Gaussian fluctuations, the developed algorithm reduces the
errors in the reconstructed map for the odd-parity modes significantly for
azimuthally symmetric masks with constant galactic latitudes. For a more
realistic Galaxy mask, we find a modest improvement in the even-parity modes as
well.


title: Application of Rough Set Theory to Analysis of Hydrocyclone Operation

abstract:
  This paper describes application of rough set theory, on the analysis of
hydrocyclone operation. In this manner, using Self Organizing Map (SOM) as
preprocessing step, best crisp granules of data are obtained. Then, using a
combining of SOM and rough set theory (RST)-called SORST-, the dominant rules
on the information table, obtained from laboratory tests, are extracted. Based
on these rules, an approximate estimation on decision attribute is fulfilled.
Finally, a brief comparison of this method with the SOM-NFIS system (briefly
SONFIS) is highlighted.


title: Extensions of the quantum Fano inequality

abstract:
  Quantum Fano inequality (QFI) in quantum information theory provides an upper
bound to the entropy exchange by a function of the entanglement fidelity. We
give various Fano-like upper bounds to the entropy exchange and QFI is a
special case of these bounds. These bounds also give an alternate derivation of
the QFI.


title: Approximation of center-valued Betti-numbers

abstract:
  In this paper we generalize the approximation theorem for L^2-Betti numbers
to an approximation theorem for center-valued Betti-numbers.


title:
Contribution of the second Landau level to the exchange energy of the
  three-dimensional electron gas in a high magnetic field

abstract:
  We derive a closed analytical expression for the exchange energy of the
three-dimensional interacting electron gas in strong magnetic fields, which
goes beyond the quantum limit (L=0) by explicitly including the effect of the
second, L=1, Landau level and arbitrary spin polarization. The inclusion of the
L=1 level brings the fields to which the formula applies closer to the
laboratory range, as compared to previous expressions, valid only for L=0 and
complete spin polarization. We identify, and explain, two distinct regimes,
separated by a critical density $n_c$. Below $n_c$, the per-particle exchange
energy is lowered by the contribution of L=1, whereas above $n_c$ it is
increased. As special cases of our general equation we recover various known,
more limited, results for higher fields, and identify and correct a few
inconsistencies in some of these earlier expressions.


title:
In situ Ramsey Interferometry and Diffraction Echo with an Ultracold
  Fermi Gas

abstract:
  We report on the first observation of Bragg scattering of an ultracold $^6$Li
Fermi gas. We demonstrate a Ramsey-type matter-wave interferometer based on
Bragg diffraction and find robust signatures of persistent matter wave
coherences using an echo pulse sequence. Because of the Pauli principle, the
diffracted fermions oscillate nearly unperturbed in the trapping potential for
long times beyond 2 s. This suggests extremely long coherence times. On these
timescales, only the presence of a $^{87}$Rb cloud seems sufficient to induce
noticeable perturbations.


title:
Rotation curve bifurcations as indicators of close recent galaxy
  encounters

abstract:
  Rotation curves of interacting galaxies often show that velocities are either
rising or falling in the direction of the companion galaxy. We seek to
reproduce and analyse these features in the rotation curves of simulated
equal-mass galaxies suffering a one-to-one encounter, as possible indicators of
close encounters. Using simulations of major mergers in 3D, we study the time
evolution of these asymmetries in a pair of galaxies, during the first passage.
Our main results are: (a) the rotation curve asymmetries appear right at
pericentre of the first passage, (b) the significant disturbed rotation
velocities occur within a small time interval, of ~ 0.5 Gyr h^-1, and therefore
the presence of bifurcation in the velocity curve could be used as an indicator
of the pericentre occurrence. These results are in qualitative agreement with
previous findings for minor mergers and fly-byes.


title: Convergence Properties of Kemp's q-Binomial Distribution

abstract:
  We consider Kemp's q-analogue of the binomial distribution. Several
convergence results involving the classical binomial, the Heine, the discrete
normal, and the Poisson distribution are established. Some of them are
q-analogues of classical convergence properties. Besides elementary estimates,
we apply Mellin transform asymptotics.


title:
Phonon density of states, anharmonicity, electron-phonon coupling and
  possible multigap superconductivity in the clathrate superconductors Ba8Si46
  and Ba24Si100: Why is Tc different in these two compounds?

abstract:
  We report a detailed study of specific heat, electrical resistivity and
thermal expansion in combination with inelastic neutron and inelastic X-ray
scattering to investigate the origin of superconductivity in the two silicon
clathrate superconductors Ba8Si46 and Ba24Si100. Both compounds have a similar
structure based on encaged barium atoms in oversized silicon cages. However,
the transition temperatures are rather different: 8 K and 1.5 K respectively.
By extracting the superconducting properties, phonon density of states,
electron-phonon coupling function and phonon anharmonicity from these
measurements we discuss the important factors governing Tc and explain the
difference between the two compounds.


title:
Orbital Degeneracy and the Microscopic Model of the FeAs Plane in the
  Iron-Based Superconductors

abstract:
  A microscopic model for the FeAs plane in the newly discovered Iron-based
superconductors is proposed with the emphasis on the role of the orbital
degeneracy between the Fe $3d_{xz}$ and $3d_{yz}$ orbital in the crystal field
environment. The model predicts commensurate antiferromagnetic ordered ground
state for the parent compounds and a d-wave superconducting ground state at
finite doping. Inter-orbital couplings plays an interesting role in enhancing
both orders. Correlated variational wave functions are proposed for both
ordered phases.


title: Fidelity approach to Gaussian transitions

abstract:
  The fidelity approach to the Gaussian transitions in spin-one XXZ spin chains
with three different values of Ising-like anisotropy lambda is analyzed by
means of the density matrix renormalization group (DMRG) technique for systems
of large sizes. We find that, despite the success in the cases of lambda=2.59
and 1, the fidelity susceptibility fails to detect the Gaussian transition for
lambda=0.5. Thus our results demonstrate the limitation of the fidelity
susceptibility in characterizing quantum phase transitions, which was proposed
recently in general frameworks.


title: Molar volume of solid isotopic helium mixtures

abstract:
  Solid isotopic helium mixtures have been studied by path-integral Monte Carlo
simulations in the isothermal-isobaric ensemble. This method allowed us to
study the molar volume as a function of temperature, pressure, and isotopic
composition. At 25 K and 0.2 GPa, the relative difference between molar volumes
of isotopically-pure crystals of 3He and 4He is found to be about 3%. This
difference decreases under pressure, and for 12 GPa it is smaller than 1%. For
isotopically-mixed crystals, a linear relation between lattice parameters and
concentrations of helium isotopes is found, in agreement with Vegard's law. The
virtual crystal approximation, valid for isotopic mixtures of heavier atoms,
does not give reliable results for solid solutions of helium isotopes.


title: Irregular turbo code design for the binary erasure channel

abstract:
  In this paper, the design of irregular turbo codes for the binary erasure
channel is investigated. An analytic expression of the erasure probability of
punctured recursive systematic convolutional codes is derived. This exact
expression will be used to track the density evolution of turbo codes over the
erasure channel, that will allow for the design of capacity-approaching
irregular turbo codes. Next, we propose a graph-optimal interleaver for
irregular turbo codes. Simulation results for different coding rates is shown
at the end.


title:
The statistical investigation of type Ib/c and II supernovae and their
  host galaxies

abstract:
  This is a statistical study of the properties of type Ib/c and II supernovae
and of the integral parameters of their spiral host galaxies. The methods of
one-dimensional and multivariate statistics were applied to the data sample. It
was found that the Ib/c supernovae are more concentrated radially toward the
centers of the galaxies than those of type II. The distributions of the radial
distances R(SN)/R(25) for the type Ib/c and II supernovae in active galaxies
are more concentrated toward the center than in normal galaxies. This effect is
stronger for type Ib/c than for type II supernovae.


title: Electric force lines of the double Reissner-Nordstrom exact solution

abstract:
  Recently, Alekseev and Belinski have presented a new exact solution of the
Einstein-Maxwell equations which describes two Reissner-Nordstrom (RN) sources
in reciprocal equilibrium (no struts nor strings); one source is a naked
singularity, the other is a black hole: this is the only possible configuration
for separable object, apart from the well-known extreme case ($m_i=e_i$).
  In the present paper, after a brief summary of this solution, we study in
some detail the coordinate systems used and the main features of the
gravitational and electric fields. In particular we graph the plots of the
electric force lines in three qualitatively different situations: equal-signed
charges, opposite charges and the case of a naked singularity near a neutral
black hole.


title:
The integral representation of solutions to a boundary value problem on
  the half-line for a system of linear ODEs with singularity of first kind

abstract:
  We consider a problem of finding vanishing at infinity
$C^1([0,\oo))$-solutions to non-homogeneous system of linear ODEs which has the
pole of first order at $x=0$. The resonant case where the corresponding
homogeneous problem has nontrivial solutions is of main interest. Under the
conditions that the homogeneous system is exponentially dichotomic on $[1,\oo)$
and the residue of system's operator at $x=0$ does not have eigenvalues with
real part 1, we construct the so called generalized Green function. We also
establish conditions under which the main non-homogeneous problem can be
reduced to the Noetherian one with nonzero index.


title:
The Initial Mass Function of the Stellar Association NGC 602 in the
  Small Magellanic Cloud with Hubble Space Telescope ACS Observations

abstract:
  We present our photometric study of the stellar association NGC 602 in the
wing of the Small Magellanic Cloud (SMC). The data were taken in the filters
F555W and F814W using the Advanced Camera for Surveys (ACS) on-board the Hubble
Space Telescope (HST). Photometry was performed using the ACS module of the
stellar photometry package DOLPHOT. We detected more than 5,500 stars with a
magnitude range of 14 \lsim m_{555} \lsim 28 mag. Three prominent stellar
concentrations are identified with star counts in the observed field, the
association NGC 602 itself, and two clusters, one of them not being currently
in any known catalog. The Color-Magnitude Diagrams (CMDs) of both clusters show
features typical for young open clusters, while that of the association reveals
bright main sequence (MS) and faint pre-main sequence (PMS) stars as the
members of the system. We construct the initial mass spectrum (IMS) of the
association by applying an age-independent method of counting the PMS stars
within evolutionary tracks, while for the bright MS stars we transform their
magnitudes to masses with the use of mass-luminosity relations. The IMS of NGC
602 is found to be well represented by a single-power law, corresponding to an
Initial Mass Function (IMF) of slope \Gamma\approx -1.2 for 1 \lsim M/M{\solar}
\lsim 45. This indicates that the shape of the IMF of a star forming system in
the SMC for stars with masses higher than 1 M{\solar} seems to be quite similar
to the field IMF in the solar neighborhood.


title:
Oscillations and interactions of dark and dark-bright solitons in
  Bose-Einstein condensates

abstract:
  Solitons are among the most distinguishing fundamental excitations in a wide
range of non-linear systems such as water in narrow channels, high speed
optical communication, molecular biology and astrophysics. Stabilized by a
balance between spreading and focusing, solitons are wavepackets, which share
some exceptional generic features like form-stability and particle-like
properties. Ultra-cold quantum gases represent very pure and well-controlled
non-linear systems, therefore offering unique possibilities to study soliton
dynamics. Here we report on the first observation of long-lived dark and
dark-bright solitons with lifetimes of up to several seconds as well as their
dynamics in highly stable optically trapped $^{87}$Rb Bose-Einstein
condensates. In particular, our detailed studies of dark and dark-bright
soliton oscillations reveal the particle-like nature of these collective
excitations for the first time. In addition, we discuss the collision between
these two types of solitary excitations in Bose-Einstein condensates.


title: Numerical study of the Coulomb blockade in an open quantum dot

abstract:
  The Coulomb blockade in an open quantum dot connected to a bulk lead by a
single mode point contact is studied numerically using the path-integral Monte
Carlo method. The Coulomb oscillation of the average charge and capacitance of
the dot is investigated, and is compared with the analytic expression for
strong tunneling. At the degeneracy point, we observe logarithmic divergence of
the capacitance for strong backscattering at the point contact. This
observation supports the conjecture that the nature of the present system at
the degeneracy point is described by the two-channel Kondo problem for an
arbitrary strength of tunneling.


title:
The structure of unicellular maps, and a connection between maps of
  positive genus and planar labelled trees

abstract:
  A unicellular map is a map which has only one face. We give a bijection
between a dominant subset of rooted unicellular maps of fixed genus and a set
of rooted plane trees with distinguished vertices. The bijection applies as
well to the case of labelled unicellular maps, which are related to all rooted
maps by Marcus and Schaeffer's bijection.
  This gives an immediate derivation of the asymptotic number of unicellular
maps of given genus, and a simple bijective proof of a formula of Lehman and
Walsh on the number of triangulations with one vertex. From the labelled case,
we deduce an expression of the asymptotic number of maps of genus g with n
edges involving the ISE random measure, and an explicit characterization of the
limiting profile and radius of random bipartite quadrangulations of genus g in
terms of the ISE.


title:
Semistablity of syzygy bundles on projective spaces in positive
  characteristics

abstract:
  In char $k = p >0$, A. Langer proved a strong restriction theorem (in the
style of H. Flenner) for semistable sheaves to a very general hypersurface of
degree $d$, on certain varieties, with the condition that `char $k > d$'. He
remarked that to remove this condition, it is enough to answer either of the
following questions affirmatively: {\it For the syzygy bundle $\sV_d$ of
${\mathcal O}(d)$, is $\sV_d$ semistable for arbitrary $n, d$ and $p = {char}
k$?, or is there a good estimate on $\mu_{max}(\sV_d^*)$?}
  Here we prove that (1) the bundle $\sV_d$ is semistable, for a certain
infinite set of integers $d\geq 0$, and (2) for arbitrary $d$, there is a good
enough estimate on $\mu_{max}(\sV_d^*)$ in terms of $d$ and $n$.
  In particular one obtains Langer's theorem, in arbitrary characeristic.


title: Radio Detection of Ultra-High Energy Cosmic Rays

abstract:
  The radio technique for the detection of cosmic particles has seen a major
revival in recent years. New and planned experiments in the lab and the field,
such as GLUE, Anita, LUNASKA, Codalema, LOPES as well as sophisticated Monte
Carlo experiments have produced a wealth of new information and I review here
briefly some of the main results with the main focus on air showers. Radio
emission of ultra-high energy cosmic particles offers a number of interesting
advantages. Since radio waves suffer no attenuation, radio measurements allow
the detection of very distant or highly inclined showers, can be used day and
night, and provide a bolometric measure of the leptonic shower component. The
LOPES experiment has detected the radio emission from cosmic rays, confirmed
the geosynchrotron effect for extensive air showers, and provided a good
calibration fomula to convert the radio signal into primary particle energy.
Moreover, Monte Carlo simulations suggest that also the shower maximum and the
particle composition can be measured. Future steps will be the installation of
radio antennas at the Auger experiment to measure the composition of ultra-high
energy cosmic rays and the usage of the LOFAR radio telescope (and later the
SKA) as a cosmic ray detector. Here an intriguing additional application is the
search for low-frequency radio emission from neutrinos and cosmic rays
interacting with the lunar regolith. This promises the best detection limits
for particles above 10^21 eV and allows one to go significantly beyond current
ground-based detectors.


title: CP violation in the chargino/neutralino sector of the MSSM

abstract:
  The CP-violating effects in the neutralino sector of the MSSM can be observed
in event-counting type experiments, i.e. without the need of exploiting
variables sensitive to beam or neutralino polarization. On the other hand, such
CP-odd effects in the chargino sector can be generated only at the loop level.
We contrast the two sectors and present results of full one-loop analysis of
the CP-odd asymmetry in the non-diagonal chargino pair production in e+e-
collisions.


title:
Matrix product state approach for a two-lead, multi-level Anderson
  impurity model

abstract:
  We exploit the common mathematical structure of the numerical renormalization
group and the density matrix renormalization group, namely, matrix product
states, to implement an efficient numerical treatment of a two-lead,
multi-level Anderson impurity model. By adopting a star-like geometry, where
each species (spin and lead) of conduction electrons is described by its own
Wilson chain, instead of using a single Wilson chain for all species together,
we achieve a very significant reduction in the numerical resources required to
obtain reliable results. We illustrate the power of this approach by
calculating ground state properties of a four-level quantum dot coupled to two
leads. The success of this proof-of-principle calculation suggests that the
star geometry constitutes a promising strategy for future calculations the
ground state properties of multi-band, multi-level quantum impurity models.
Moreover, we show that it is possible to find an "optimal" chain basis,
obtained via a unitary transformation (acting only on the index distinguishing
different Wilson chains), in which degrees of freedom on different Wilson
chains become effectively decoupled from each other further out on the Wilson
chains. This basis turns out to also diagonalize the model's chain-to-chain
scattering matrix. We demonstrate this for a spinless two-lead model,
presenting DMRG-results for the mutual information between two sites located
far apart on different Wilson chains, and NRG results with respect to the
scattering matrix.


title: Statistical performance of support vector machines

abstract:
  The support vector machine (SVM) algorithm is well known to the computer
learning community for its very good practical results. The goal of the present
paper is to study this algorithm from a statistical perspective, using tools of
concentration theory and empirical processes. Our main result builds on the
observation made by other authors that the SVM can be viewed as a statistical
regularization procedure. From this point of view, it can also be interpreted
as a model selection principle using a penalized criterion. It is then possible
to adapt general methods related to model selection in this framework to study
two important points: (1) what is the minimum penalty and how does it compare
to the penalty actually used in the SVM algorithm; (2) is it possible to obtain
``oracle inequalities'' in that setting, for the specific loss function used in
the SVM algorithm? We show that the answer to the latter question is positive
and provides relevant insight to the former. Our result shows that it is
possible to obtain fast rates of convergence for SVMs.


title: The fuzzball proposal for black holes

abstract:
  The fuzzball proposal states that associated with a black hole of entropy S
there are exp S horizon-free non-singular solutions that asymptotically look
like the black hole but generically differ from the black hole up to the
horizon scale. These solutions, the fuzzballs, are considered to be the black
hole microstates while the original black hole represents the average
description of the system. The purpose of this report is to review current
evidence for the fuzzball proposal, emphasizing the use of AdS/CFT methods in
developing and testing the proposal. In particular, we discuss the status of
the proposal for 2 and 3 charge black holes in the D1-D5 system, presenting new
derivations and streamlining the discussion of their properties. Results to
date support the fuzzball proposal but further progress is likely to require
going beyond the supergravity approximation and sharpening the definition of a
"stringy fuzzball". We outline how the fuzzball proposal could resolve
longstanding issues in black hole physics, such as Hawking radiation and
information loss. Our emphasis throughout is on connecting different
developments and identifying open problems and directions for future research.


title: Non-minimally Coupled Quintom Model Inspired by String Theory

abstract:
  In this paper we consider a quintom model of dark energy with a single scalar
field $T$ given by a Lagrangian which inspired by tachyonic Lagrangian in
string theory. We consider non-minimal coupling of tachyon field to the scalar
curvature, then we obtain the equation of state (EoS), and the condition
required for the model parameters when $\omega$ crosses over -1.


title:
Searching for Neutrinos from WIMP Annihilations in the Galactic Stellar
  Disk

abstract:
  Weakly interacting massive particles (WIMPs) are a viable candidate for the
relic abundance of dark matter (DM) produced in the early universe. So far
WIMPs have eluded direct detection through interactions with baryonic matter.
Neutrino emission from accumulated WIMP annihilations in the solar core has
been proposed as a signature of DM, but has not yet been detected. These null
results may be due to small scale DM density fluctuations in the halo with the
density of our local region being lower than the average (around 0.3 GeV/cm^3
). However, the accumulated neutrino signal from WIMP annihilations in the
Galactic stellar disk would be insensitive to local density variations. Inside
the disk, dark matter can be captured by stars causing an enhanced annihilation
rate and therefore a potentially higher neutrino flux than what would be
observed from elsewhere in the halo. We estimate a neutrino flux from the WIMP
annihilations in the stellar disk to be enhanced by more than an order of
magnitude compared to the neutrino fluxes from the halo. We offer a
conservative estimate for this enhanced flux, based on the WIMP-nucleon
cross-sections obtained from direct-detection experiments by assuming a density
of around 0.3 GeV/cm^3 for the local DM. We also compare the detectability of
these fluxes with a signal of diffuse high energy neutrinos produced in the
Milky Way by the interaction of cosmic rays (CRs) with the interstellar medium
(ISM). These comparative signals should be observable by large neutrino
detectors.


title: M{\o}ller's energy of the Kerr-NUT Metric

abstract:
  The energy distribution of the Kerr-NUT space-time is calculated using M\o
ller's energy-momentum complex within the framework of the Riemannian geometry.


title:
RubberEdge: Reducing Clutching by Combining Position and Rate Control
  with Elastic Feedback

abstract:
  Position control devices enable precise selection, but significant clutching
degrades performance. Clutching can be reduced with high control-display gain
or pointer acceleration, but there are human and device limits. Elastic rate
control eliminates clutching completely, but can make precise selection
difficult. We show that hybrid position-rate control can outperform position
control by 20% when there is significant clutching, even when using pointer
acceleration. Unlike previous work, our RubberEdge technique eliminates
trajectory and velocity discontinuities. We derive predictive models for
position control with clutching and hybrid control, and present a prototype
RubberEdge position-rate control device including initial user feedback.


title:
Gauge theoretical methods in the classification of non-Kaehlerian
  surfaces

abstract:
  The classification of class VII surfaces is a very difficult classical
problem in complex geometry. It is considered by experts to be the most
important gap in the Enriques-Kodaira classification table for complex
surfaces. The standard conjecture concerning this problem states that any
minimal class VII surface with $b_2>0$ has $b_2$ curves. By the results of
Kato, Nakamura and Dloussky/Oeljeklaus/Toma, this conjecture (if true) would
solve this classification problem completely. We explain a new approach (based
on techniques from Donaldson theory) to prove existence of curves on class VII
surfaces, and we present recent results obtained using this approach.


title: Agent-Based Perception of an Environment in an Emergency Situation

abstract:
  We are interested in the problem of multiagent systems development for risk
detecting and emergency response in an uncertain and partially perceived
environment. The evaluation of the current situation passes by three stages
inside the multiagent system. In a first time, the situation is represented in
a dynamic way. The second step, consists to characterise the situation and
finally, it is compared with other similar known situations. In this paper, we
present an information modelling of an observed environment, that we have
applied on the RoboCupRescue Simulation System. Information coming from the
environment are formatted according to a taxonomy and using semantic features.
The latter are defined thanks to a fine ontology of the domain and are managed
by factual agents that aim to represent dynamically the current situation.


title: Neutron-Mirror-Neutron Oscillations in a Trap

abstract:
  We calculate the rate of neutron-mirror-neutron oscillations for ultracold
neutrons trapped in a storage vessel. Recent experimental bounds on the
oscillation time are discussed.


title:
High order relaxed schemes for nonlinear reaction diffusion problems in
  nonconservative form

abstract:
  Different relaxation approximations to partial differential equations,
including conservation laws, Hamilton-Jacobi equations, convection-diffusion
problems, gas dynamics problems, have been recently proposed. The present paper
focuses onto diffusive relaxed schemes for the numerical approximation of
nonlinear reaction diffusion equations. We choose here a nonstandard relaxation
scheme that allow the treatment of diffusion equations in their nonconservative
form. A comparison with the traditional approach in the case of conservative
equations is also included.
  High order methods are obtained by coupling ENO and WENO schemes for space
discretization with IMEX schemes for time integration, where the implicit part
can be explicitly solved at a linear cost. To illustrate the high accuracy and
good properties of the proposed numerical schemes, also in the degenerate case,
we consider various examples in one and two dimensions: the Fisher-Kolmogoroff
equation, the porous-Fisher equation and the porous medium equation with strong
absorption. Moreover we show a test on a system of PDEs that describe an
ecological model for the dispersal and settling of animal populations.


title:
Realistic Haptic Rendering of Interacting Deformable Objects in Virtual
  Environments

abstract:
  A new computer haptics algorithm to be used in general interactive
manipulations of deformable virtual objects is presented. In multimodal
interactive simulations, haptic feedback computation often comes from contact
forces. Subsequently, the fidelity of haptic rendering depends significantly on
contact space modeling. Contact and friction laws between deformable models are
often simplified in up to date methods. They do not allow a "realistic"
rendering of the subtleties of contact space physical phenomena (such as slip
and stick effects due to friction or mechanical coupling between contacts). In
this paper, we use Signorini's contact law and Coulomb's friction law as a
computer haptics basis. Real-time performance is made possible thanks to a
linearization of the behavior in the contact space, formulated as the so-called
Delassus operator, and iteratively solved by a Gauss-Seidel type algorithm.
Dynamic deformation uses corotational global formulation to obtain the Delassus
operator in which the mass and stiffness ratio are dissociated from the
simulation time step. This last point is crucial to keep stable haptic
feedback. This global approach has been packaged, implemented, and tested.
Stable and realistic 6D haptic feedback is demonstrated through a clipping task
experiment.


title:
Density-functional description of superconducting and magnetic proximity
  effects across a tunneling barrier

abstract:
  A density-functional formalism for superconductivity {\em and} magnetism is
presented. The resulting relations unify previously derived Kohn-Sham equations
for superconductors and for non-collinear magnetism. The formalism, which
discriminates Cooper pair singlets from triplets, is applied to two quantum
liquids coupled by tunneling through a barrier. An exact expression is derived,
relating the eigenstates and eigenvalues of the Kohn-Sham equations,
unperturbed by tunneling, on one side of the barrier to the proximity-induced
ordering potential on the other.


title: Homogenization of variational problems in manifold valued BV-spaces

abstract:
  This paper extends the result of \cite{BM} on the homogenization of integral
functionals with linear growth defined for Sobolev maps taking values in a
given manifold. Through a $\Gamma$-convergence analysis, we identify the
homogenized energy in the space of functions of bounded variation. It turns out
to be finite for $BV$-maps with values in the manifold. The bulk and Cantor
parts of the energy involve the tangential homogenized density introduced in
\cite{BM}, while the jump part involves an homogenized surface density given by
a geodesic type problem on the manifold.


title: Gibbs Ensembles of Nonintersecting Paths

abstract:
  We consider a family of determinantal random point processes on the
two-dimensional lattice and prove that members of our family can be interpreted
as a kind of Gibbs ensembles of nonintersecting paths. Examples include
probability measures on lozenge and domino tilings of the plane, some of which
are non-translation-invariant.
  The correlation kernels of our processes can be viewed as extensions of the
discrete sine kernel, and we show that the Gibbs property is a consequence of
simple linear relations satisfied by these kernels. The processes depend on
infinitely many parameters, which are closely related to parametrization of
totally positive Toeplitz matrices.


title: Nonstandard Hulls of Locally Exponential Lie Algebras

abstract:
  We show how to construct the nonstandard hull of certain infinite-dimensional
Lie algebras in order to generalize a theorem of Pestov on the enlargeability
of Banach-Lie algebras. In the process, we consider a nonstandard smoothness
condition on functions between locally convex spaces to ensure that the induced
function between the nonstandard hulls is smooth. We also discuss some
conditions on a function between locally convex spaces which guarantee that its
nonstandard extension maps finite points to finite points.


title: Kinetic transport in the two-dimensional periodic Lorentz gas

abstract:
  The periodic Lorentz gas describes an ensemble of non-interacting point
particles in a periodic array of spherical scatterers. We have recently shown
that, in the limit of small scatterer density (Boltzmann-Grad limit), the
macroscopic dynamics converges to a stochastic process, whose kinetic transport
equation is not the linear Boltzmann equation--in contrast to the Lorentz gas
with a disordered scatterer configuration. The present paper focuses on the
two-dimensional set-up, and reports an explicit, elementary formula for the
collision kernel of the transport equation.


title:
Ionisation of hydrogen molecule in intense ultrashort laser pulses:
  parallel versus perpendicular orientation

abstract:
  A theoretical comparison of the electronic excitation and ionisation
behaviour of molecular hydrogen oriented either parallel or perpendicular to a
linear polarised laser pulse is performed. The investigation is based on a
non-perturbative treatment that solves the full time-dependent Schr\"odinger
equation of both correlated electrons within the fixed-nuclei approximation and
the dipole. Results are shown for two different laser pulse lengths and
intensities as well as for a large variety of photon frequencies starting in
the 1- and reaching into the 6-photon regime. In order to investigate the
influence of the intrinsic diatomic two-center problem even further, two values
of the internuclear separation and a newly developed atomic model are
considered.


title:
Index theorem in spontaneously symmetry-broken gauge theories on a fuzzy
  2-sphere

abstract:
  We consider a gauge-Higgs system on a fuzzy 2-sphere and study the
topological structure of gauge configurations, when the U(2) gauge symmetry is
spontaneously broken to U(1) times U(1) by the vev of the Higgs field. The
topology is classified by the index of the Dirac operator satisfying the
Ginsparg-Wilson relation, which turns out to be a noncommutative analog of the
topological charge introduced by 't Hooft. It can be rewritten as a form whose
commutative limit becomes the winding number of the Higgs field. We also study
conditions which assure the validity of the formulation, and give a
generalization of the admissibility condition. Finally we explicitly calculate
the topological charge of a one-parameter family of configurations.


title: Dynamics of perturbations in disordered chaotic systems

abstract:
  We study the time evolution of perturbations in spatially extended chaotic
systems in the presence of quenched disorder. We find that initially random
perturbations tend to exponentially localize in space around static pinning
centers that are selected by the particular configuration of disorder. The
spatial structure of typical perturbations, $\delta u(x,t)$, is analyzed in
terms of the Hopf-Cole transform, $h(x,t) \equiv\ln|\delta u(x,t)|$. Our
analysis shows that the associated surface $h(x,t)$ self-organizes into a
faceted structure with scale-invariant correlations. Scaling analysis of
critical roughening exponents reveals that there are three different
universality classes for error propagation in disordered chaotic systems that
correspond to different symmetries of the underlying disorder. Our conclusions
are based on numerical simulations of disordered lattices of coupled chaotic
elements and equations for diffusion in random potentials. We propose a
phenomenological stochastic field theory that gives some insights on the path
for a generalization of these results for a broad class of disordered extended
systems exhibiting space-time chaos.


title: A Parameterized Perspective on $P_2$-Packings

abstract:
  }We study (vertex-disjoint) $P_2$-packings in graphs under a parameterized
perspective. Starting from a maximal $P_2$-packing $\p$ of size $j$ we use
extremal arguments for determining how many vertices of $\p$ appear in some
$P_2$-packing of size $(j+1)$. We basically can 'reuse' $2.5j$ vertices. We
also present a kernelization algorithm that gives a kernel of size bounded by
$7k$. With these two results we build an algorithm which constructs a
$P_2$-packing of size $k$ in time $\Oh^*(2.482^{3k})$.


title:
Loschmidt echo for local perturbations: non-monotonous cross-over from
  the Fermi-golden-rule to the escape-rate regime

abstract:
  We address the sensitivity of quantum mechanical time evolution by
considering the time decay of the Loschmidt echo (LE) (or fidelity) for local
perturbations of the Hamiltonian. Within a semiclassical approach we derive
analytical expressions for the LE decay for chaotic systems for the whole range
from weak to strong local perturbations and identify different decay regimes
which complement those known for the case of global perturbations. For weak
perturbations a Fermi-golden-rule (FGR) type behavior is recovered. For strong
perturbations the escape-rate regime is reached, where the LE decays
exponentially with a rate independent of the perturbation strength. The
transition between the FGR regime and the escape-rate regime is non-monotonic,
i.e. the rate of the exponential time-decay of the LE oscillates as a function
of the perturbation strength. We further perform extensive quantum mechanical
calculations of the LE based on numerical wave packet evolution which strongly
support our semiclassical theory. Finally, we discuss in some detail possible
experimental realizations for observing the predicted behavior of the LE.


title:
On the coupling between spinning particles and cosmological
  gravitational waves

abstract:
  The influence of spin in a system of classical particles on the propagation
of gravitational waves is analyzed in the cosmological context of primordial
thermal equilibrium. On a flat Friedmann-Robertson-Walker metric, when the
precession is neglected, there is no contribution due to the spin to the
distribution function of the particles. Adding a small tensor perturbation to
the background metric, we study if a coupling between gravitational waves and
spin exists that can modify the evolution of the distribution function, leading
to new terms in the anisotropic stress, and then to a new source for
gravitational waves. In the chosen gauge, the final result is that, in the
absence of other kind of perturbations, there is no coupling between spin and
gravitational waves.


title: An Artificial Immune System as a Recommender System for Web Sites

abstract:
  Artificial Immune Systems have been used successfully to build recommender
systems for film databases. In this research, an attempt is made to extend this
idea to web site recommendation. A collection of more than 1000 individuals web
profiles (alternatively called preferences / favourites / bookmarks file) will
be used. URLs will be classified using the DMOZ (Directory Mozilla) database of
the Open Directory Project as our ontology. This will then be used as the data
for the Artificial Immune Systems rather than the actual addresses. The first
attempt will involve using a simple classification code number coupled with the
number of pages within that classification code. However, this implementation
does not make use of the hierarchical tree-like structure of DMOZ.
Consideration will then be given to the construction of a similarity measure
for web profiles that makes use of this hierarchical information to build a
better-informed Artificial Immune System.


title:
Revisiting non-Gaussianity of multiple-field inflation from the field
  equation

abstract:
  In the present paper, we study the non-Gaussianity of multiple-field
inflation model using the method of the field equation. We start from reviewing
the background and the perturbation theory of multiple-field inflation, and
then derive the Klein-Gorden equation for the perturbations at second order.
Afterward, we calculate the tree-level bispectrum of the fields' perturbations
and finally give the corresponding parameter $f_{NL}$ for the curvature
perturbation $\zeta$ in virtue of the $\delta N$ formalism. We also compare our
result with the one already obtained from the Lagrangian formalism, and find
they are consistent. This work may help us understand perturbation theory of
inflation more deeply.


title: Improving resolution by means of ghost imaging

abstract:
  As one of important analysis tools, microscopes with high spatial resolution
are indispensable for scientific research and medical diagnosis, and much
attention is always focused on the improvement of resolution. Over the past
decade, a novel technique called ghost imaging has been developed that may
provide a new approach toward increasing the resolution of an imaging system.
In this paper, we introduce this technique into microscopes for the first time
and report a proof-of-principle experimental demonstration of a microscope
scheme based on ghost imaging.


title: Cauchy-Kowaleskaya-Kashiwara theorem with growth conditions

abstract:
  We prove the Cauchy-Kowaleskaya-Kashiwara theorem for holomorphic functions
with growth conditions.


title: Decentralized Search with Random Costs

abstract:
  A decentralized search algorithm is a method of routing on a random graph
that uses only limited, local, information about the realization of the graph.
In some random graph models it is possible to define such algorithms which
produce short paths when routing from any vertex to any other, while for others
it is not.
  We consider random graphs with random costs assigned to the edges. In this
situation, we use the methods of stochastic dynamic programming to create a
decentralized search method which attempts to minimize the total cost, rather
than the number of steps, of each path. We show that it succeeds in doing so
among all decentralized search algorithms which monotonically approach the
destination. Our algorithm depends on knowing the expected cost of routing from
every vertex to any other, but we show that this may be calculated iteratively,
and in practice can be easily estimated from the cost of previous routes and
compressed into a small routing table. The methods applied here can also be
applied directly in other situations, such as efficient searching in graphs
with varying vertex degrees.


title: Characteristic polynomials of automorphisms of hyperelliptic curves

abstract:
  Let alpha be an automorphism of a hyperelliptic curve C of genus g, and let
alpha' be the automorphism of P^1 induced by alpha. Let n be the order of alpha
and let n' be the order of alpha'. We show that the triple (g,n,n') completely
determines the characteristic polynomial of the automorphism alpha^* of the
Jacobian of C, unless n is even, n=n', and (2g+2)/n is even, in which case
there are two possibilities. We give explicit formulas for the characteristic
polynomial in all cases.


title: Tropical Hurwitz Numbers

abstract:
  Hurwitz numbers count genus g, degree d covers of the projective line with
fixed branch locus. This equals the degree of a natural branch map defined on
the Hurwitz space. In tropical geometry, algebraic curves are replaced by
certain piece-wise linear objects called tropical curves. This paper develops a
tropical counterpart of the branch map and shows that its degree recovers
classical Hurwitz numbers.


title: Explicit Learning: an Effort towards Human Scheduling Algorithms

abstract:
  Scheduling problems are generally NP-hard combinatorial problems, and a lot
of research has been done to solve these problems heuristically. However, most
of the previous approaches are problem-specific and research into the
development of a general scheduling algorithm is still in its infancy.
  Mimicking the natural evolutionary process of the survival of the fittest,
Genetic Algorithms (GAs) have attracted much attention in solving difficult
scheduling problems in recent years. Some obstacles exist when using GAs: there
is no canonical mechanism to deal with constraints, which are commonly met in
most real-world scheduling problems, and small changes to a solution are
difficult. To overcome both difficulties, indirect approaches have been
presented (in [1] and [2]) for nurse scheduling and driver scheduling, where
GAs are used by mapping the solution space, and separate decoding routines then
build solutions to the original problem.


title:
Computing a Finite Size Representation of the Set of Approximate
  Solutions of an MOP

abstract:
  Recently, a framework for the approximation of the entire set of
$\epsilon$-efficient solutions (denote by $E_\epsilon$) of a multi-objective
optimization problem with stochastic search algorithms has been proposed. It
was proven that such an algorithm produces -- under mild assumptions on the
process to generate new candidate solutions --a sequence of archives which
converges to $E_{\epsilon}$ in the limit and in the probabilistic sense. The
result, though satisfactory for most discrete MOPs, is at least from the
practical viewpoint not sufficient for continuous models: in this case, the set
of approximate solutions typically forms an $n$-dimensional object, where $n$
denotes the dimension of the parameter space, and thus, it may come to
perfomance problems since in practise one has to cope with a finite archive.
Here we focus on obtaining finite and tight approximations of $E_\epsilon$, the
latter measured by the Hausdorff distance. We propose and investigate a novel
archiving strategy theoretically and empirically. For this, we analyze the
convergence behavior of the algorithm, yielding bounds on the obtained
approximation quality as well as on the cardinality of the resulting
approximation, and present some numerical results.


title: Finite Temperature Theory of Metastable Anharmonic Potentials

abstract:
  The decay rate for a particle in a metastable cubic potential is investigated
in the quantum regime by the Euclidean path integral method in semiclassical
approximation. The imaginary time formalism allows one to monitor the system as
a function of temperature. The family of classical paths, saddle points for the
action, is derived in terms of Jacobian elliptic functions whose periodicity
sets the energy-temperature correspondence. The period of the classical
oscillations varies monotonically with the energy up to the sphaleron, pointing
to a smooth crossover from the quantum to the activated regime. The softening
of the quantum fluctuation spectrum is evaluated analytically by the theory of
the functional determinants and computed at low $T$ up to the crossover. In
particular, the negative eigenvalue, causing an imaginary contribution to the
partition function, is studied in detail by solving the Lam\`{e} equation which
governs the fluctuation spectrum. For a heavvy particle mass, the decay rate
shows a remarkable temperature dependence mainly ascribable to a low lying soft
mode and, approaching the crossover, it increases by a factor five over the
predictions of the zero temperature theory. Just beyond the peak value, the
classical Arrhenius behavior takes over. A similar trend is found studying the
quartic metastable potential but the lifetime of the latter is longer by a
factor ten than in a cubic potential with same parameters. Some formal
analogies with noise-induced transitions in classically activated metastable
systems are discussed.


title: Mazur intersection property for Asplund spaces

abstract:
  The main result of the present note states that it is consistent with the ZFC
axioms of set theory (relying on Martin's Maximum MM axiom), that every Asplund
space of density character $\omega_1$ has a renorming with the Mazur
intersection property. Combined with the previous result of Jim\' enez and
Moreno (based upon the work of Kunen under the continuum hypothesis) we obtain
that the MIP normability of Asplund spaces of density $\omega_1$ is undecidable
in ZFC.


title: "Black Universe" epoch in String Cosmology

abstract:
  String theory compactification involves manifolds with multiple warp factors.
For cosmological applications, one often introduces a short, high-energy
inflationary throat, and a long,low-energy Standard Model throat. It is assumed
that at the end of inflation,the excited Kaluza-Klein modes from the
Inflationary throat tunnel to the SM throat and reheat Standard Model degrees
of freedom, which are attached to probe brane(s). However, the huge hierarchy
of energy scales can result in a highly dynamic transition of the throat
geometry. We point out that in such a cosmological scenario the Standard Model
throat (together with SM brane) will be cloaked by a Schwarzschild horizon,
produced by the Kaluza-Klein modes tunneling from the short throat. The Black
Brane formation is dual to the first order chiral phase transition of the
cascading gauge theory. We calculate the critical energy density corresponding
the formation of the the BH horizon in the long throat. We discuss the duality
between "Black Universe" cosmology and an expanding universe driven by the hot
gauge theory radiation. We address the new problem of the hierarchical
multiple-throat scenarios: SM brane disappearance after the decay of the BH
horizon.


title:
Surface solitons at interfaces of arrays with spatially-modulated
  nonlinearity

abstract:
  We address the properties of two-dimensional surface solitons supported by
the interface of a waveguide array whose nonlinearity is periodically
modulated. When the nonlinearity strength reaches its minima at the points
where the linear refractive index attains its maxima, we found that nonlinear
surface waves exist and can be made stable only within a limited band of input
energy flows, and for lattice depths exceeding a lower threshold.


title: Fractional Heisenberg Equation

abstract:
  Fractional derivative can be defined as a fractional power of derivative. The
commutator (i/h)[H, ], which is used in the Heisenberg equation, is a
derivation on a set of observables. A derivation is a map that satisfies the
Leibnitz rule. In this paper, we consider a fractional derivative on a set of
quantum observables as a fractional power of the commutator (i/h)[H, ]. As a
result, we obtain a fractional generalization of the Heisenberg equation. The
fractional Heisenberg equation is exactly solved for the Hamiltonians of free
particle and harmonic oscillator. The suggested Heisenberg equation generalize
a notion of quantum Hamiltonian systems to describe quantum dissipative
processes.


title: Optimal eavesdropping on noisy states in quantum key distribution

abstract:
  We study eavesdropping in quantum key distribution with the six state
protocol,when the signal states are mixed with white noise. This situation may
arise either when Alice deliberately adds noise to the signal states before
they leave her lab, or in a realistic scenario where Eve cannot replace the
noisy quantum channel by a noiseless one. We find Eve's optimal mutual
information with Alice, for individual attacks, as a function of the qubit
error rate. Our result is that added quantum noise can make quantum key
distribution more robust against eavesdropping.


title: Potential level-lowering for GSp(4)

abstract:
  In this preprint, we explore a beautiful idea of Skinner and Wiles in the
context of GSp(4) over a totally real field. The main result provides
congruences between automorphic forms which are Iwahori-spherical at a certain
place w, and forms with a tamely ramified principal series at w. Thus, after
base change to a totally real finite solvable extension, one can often lower
the level at w. For the proof, we first establish an analogue of the
Jacquet-Langlands correspondence, using the stable trace formula. The
congruences are then obtained on inner forms, which are compact at infinity mod
center, and split at all finite places. The crucial ingredient allowing us to
do so, is an important result of Roche on types for principal series
representations of split reductive groups.


title:
Comment on 'Discreteness Effects in Lambda Cold Dark Matter Simulations:
  A Wavelet-Statistical View' by Romeo et al

abstract:
  Essential equivalence of the conclusions of Romeo et al. (arXiv:0804.0294v1)
with earlier work is pointed out. A possible general explanation for these
conclusions is suggested.


title: Minimal links and a result of Gaeta

abstract:
  If $V$ is an equidimensional codimension $c$ subscheme of an $n$-dimensional
projective space, and $V$ is linked to $V'$ by a complete intersection $X$,
then we say that $V$ is {\em minimally linked} to $V'$ if $X$ is a codimension
$c$ complete intersection of smallest degree containing $V$. Gaeta showed that
if $V$ is any arithmetically Cohen-Macaulay (ACM) subscheme of codimension two
then there is a finite sequence of minimal links beginning with $V$ and
arriving at a complete intersection. We extend this work in the following ways:
1) In the codimension 2 non-ACM case, we show that for any $n \geq 3$ there are
examples of subschemes that are not minimal in their even liaison class, and
cannot be minimally linked in any number of steps to a minimal subscheme. 2)
Nevertheless, there are examples of non-ACM liaison classes of curves in
projective 3-space where all elements are minimally linked in a finite number
of steps to a minimal curve. 3) Extending previous work of the authors with
Huneke and Ulrich (about the licci case), we show that also in the non-ACM case
in any higher codimension there are non-minimal subschemes that are not
minimally linked to a minimal subscheme in the even liaison class. 4) J.
Watanabe had shown many years ago that codimension 3 graded Gorenstein ideals
of any dimension are licci. Here we show that any such ideal is minimally
linked in a finite number of steps to a complete intersection, and that it
admits a sequence of strictly decreasing CI-biliaisons down to a complete
intersection, extending work of Hartshorne, Sabadini and Schlesinger.


title:
Multiple Andreev reflections in a quantum dot coupled to
  superconductors: Effects of spin-orbit coupling

abstract:
  We study the out-of-equilibrium current through a multilevel quantum dot
contacted to two superconducting leads and in the presence of Rashba and
Dresselhaus spin-orbit couplings, in the regime of strong dot-lead coupling.
The multiple Andreev reflection (MAR) subgap peaks in the current voltage
characteristics are found to be modified (but not suppressed) by the spin-orbit
interaction, in a way that strongly depends on the shape of the dot confining
potential. In a perfectly isotropic dot the MAR peaks are enhanced when the
strength $\alpha_R$ and $\alpha_D$ of Rashba and Dresselhaus terms are equal.
When the anisotropy of the dot confining potential increases the dependence of
the subgap structure on the spin-orbit angle
$\theta=\arctan(\alpha_D/\alpha_R)$ decreases. Furthermore, when an in-plane
magnetic field is applied to a strongly anisotropic dot, the peaks of the
non-linear conductance oscillate as a function of the magnetic field angle, and
the location of the maxima and minima allows for a straightforward read-out of
the spin-orbit angle $\theta$.


title:
Deflected Mirage Mediation: A Framework for Generalized Supersymmetry
  Breaking

abstract:
  We present a general phenomenological framework for dialing between gravity
mediation, gauge mediation, and anomaly mediation. The approach is motivated
from recent developments in moduli stabilization, which suggest that gravity
mediated terms can be effectively loop suppressed and thus comparable to gauge
and anomaly mediated terms. The gauginos exhibit a mirage unification behavior
at a "deflected" scale, and gluinos are often the lightest colored sparticles.
The approach provides a rich setting in which to explore generalized
supersymmetry breaking at the LHC.