title: Moduli and multi-field inflation

abstract:
  Moduli with flat or run-away classical potentials are generic in theories
based on supersymmetry and extra dimensions. They mix between themselves and
with matter fields in kinetic terms and in the nonperturbative superpotentials.
As the result, interesting structure appears in the scalar potential which
helps to stabilise and trap moduli and leads to multi-field inflation. The new
and attractive feature of multi-inflationary setup are isocurvature
perturbations which can modify in an interesting way the final spectrum of
primordial fluctuations resulting from inflation.


title: SGRs and AXPs proposed as ancestors of the Magnificent seven

abstract:
  The recently suggested correlation between the surface temperature and the
magnetic field in isolated neutron stars does not seem to work well for SGRs,
AXPs and X-ray dim isolated neutron stars (XDINs; specifically the Magnificent
Seven or M7). Instead by appealing to a Color-Flavor Locked Quark Star (CFLQS)
we find a more natural explanation. In this picture, the heating is provided by
magnetic flux expulsion from a crust-less superconducting quark star. Combined
with our previous studies concerning the possibility of SGRs, AXPs, and XDINs
as CFLQSs, this provides another piece of evidence that these objects are all
related. Specifically, we propose that XDINs are the descendants of SGRs and
AXPs.


title:
Marginal and density atomic Wehrl entropies for the Jaynes-Cummings
  model

abstract:
  In this paper, we develop the notion of the marginal and density atomic Wehrl
entropies for two-level atom interacting with the single mode field, i.e.
Jaynes-Cummings model. For this system we show that there are relationships
between these quantities and both of the information entropies and the von
Neumann entropy.


title:
Spectral resolved Measurement of the Nitrogen Fluorescence Emissions in
  Air induced by Electrons

abstract:
  For the calorimetric determination of the primary energy of extensive air
showers, measured by fluorescence telescopes, a precise knowledge of the
conversion factor (fluorescence yield) between the deposited energy in the
atmosphere and the number of emitted fluorescence photons is essential. The
fluorescence yield depends on the pressure and the temperature of the air as
well as on the water vapor concentration. Within the scope of this work the
fluorescence yield for the eight strongest nitrogen emission bands between 300
nm and 400 nm has been measured using electrons from a Sr-90 source with
energies between 250 keV and 2000 keV. Measurements have been performed in dry
air, pure nitrogen, and a nitrogen-oxygen mixture at pressures ranging from 2
hPa to 990 hPa. Furthermore the influence of water vapor has been studied. A
new approach for the parametrization of the fluorescence yield was used to
analyze the data, leading to a consistent description of the fluorescence yield
with a minimal set of parameters. The resulting absolute accuracies for the
single nitrogen bands are in the order of 15%. In the investigated energy
range, the fluorescence yield proved to be independent of the energy of the
ionizing electrons.


title:
Thermodynamic restrictions on evolutionary optimization of transcription
  factor proteins

abstract:
  Conformational fluctuations are believed to play an important role in the
process by which transcription factor proteins locate and bind their target
site on the genome of a bacterium. Using a simple model, we show that the
binding time can be minimized, under selective pressure, by adjusting the
spectrum of conformational states so that the fraction of time spent in more
mobile conformations is matched with the target recognition rate. The
associated optimal binding time is then within an order of magnitude of the
limiting binding time imposed by thermodynamics, corresponding to an idealized
protein with instant target recognition. Numerical estimates suggest that
typical bacteria operate in this regime of optimized conformational
fluctuations.


title: Coalescence in low-viscosity liquids

abstract:
  The expected universal dynamics associated with the initial stage of droplet
coalescence are difficult to study visually due to the rapid motion of the
liquid and the awkward viewing geometry. Here we employ an electrical method to
study the coalescence of two inviscid droplets at early times. We measure the
growth dynamics of the bridge connecting the two droplets and observe a new
asymptotic regime inconsistent with previous theoretical predictions. The
measurements are consistent with a model in which the two liquids coalesce with
a slightly deformed interface.


title:
Selection of special orientations in relativistic collisions of deformed
  heavy nuclei

abstract:
  We have studied U+U collisions at $\sqrt{s_{NN}}$ = 200 GeV using Monte Carlo
Glauber, UrQMD and AMPT models. We find that it is possible to separate central
tip-tip events as well as central body-body events on the basis of cuts on
multiplicity and magnitude of the reduced flow vector.


title:
Some remarks on conic degeneration and bending of Poincar\'e-Einstein
  metrics

abstract:
  Let $(M,g)$ be a compact K\"ahler-Einstein manifold with $c_1 > 0$. Denote by
$K\to M$ the canonical line-bundle, with total space $X$, and $X_0$ the
singular space obtained by blowing down $X$ along its zero section. We employ a
construction by Page and Pope and discuss an interesting multi-parameter family
of Poincar\'e--Einstein metrics on $X$. One 1-parameter subfamily
$\{g_t\}_{t>0}$ has the property that as $t\searrow 0$, $g_t$ converges to a PE
metric $g_0$ on $X_0$ with conic singularity, while $t^{-1}g_t$ converges to a
complete Ricci-flat K\"ahler metric $\hat{g}_0$ on $X$. Another 1-parameters
subfamily has an edge singularity along the zero section of $X$, with cone
angle depending on the parameter, but has constant conformal infinity. These
illustrate some unexpected features of the Poincar\'e-Einstein moduli space.


title: Markoff Equation and Nilpotent Matrices

abstract:
  A triple (a,b,c) of positive integers is called a Markoff triple iff it
satisfies the diophantine equation a2 + b2 + c2 = abc .
  Recasting the Markoff tree, whose vertices are Markoff triples, in the
framework of intergral upper triangular 3x3 matrices, it will be shown that the
largest member of such a triple determines the other two uniquely. This answers
a question which has been open for almost 100 years.


title: The Graver Complexity of Integer Programming

abstract:
  In this article we establish an exponential lower bound on the Graver
complexity of integer programs. This provides new type of evidence supporting
the presumable intractability of integer programming. Specifically, we show
that the Graver complexity of the incidence matrix of the complete bipartite
graph $K_{3,m}$ satisfies $g(m)=\Omega(2^m)$, with $g(m)\geq 17\cdot 2^{m-3}-7$
for every $m>3$ .


title:
The Luminous and Carbon-Rich Supernova 2006gz: A Double Degenerate
  Merger?

abstract:
  Spectra and light curves of SN 2006gz show the strongest signature of
unburned carbon and one of the slowest fading light curves ever seen in a type
Ia event (Delta m_15 = 0.69 +/- 0.04). The early-time Si II velocity is low,
implying it was slowed by an envelope of unburned material. Our best estimate
of the luminosity implies M_V = -19.74 and the production of ~ 1.2 M_sun of
56Ni. This suggests a super-Chandrasekhar mass progenitor. A double degenerate
merger is consistent with these observations.


title: Ignition of superconducting vortices by acoustic standing waves

abstract:
  Nucleation of vortices in a superconductor below the first critical field can
be assisted by transverse sound in the GHz frequency range. Vortices will enter
and exist the superconductor at the frequency of the sound. We compute the
threshold parameters of the sound and show that this effect is within
experimental reach.


title:
A Scintillator Purification System for the Borexino Solar Neutrino
  Detector

abstract:
  Purification of the 278 tons of liquid scintillator and 889 tons of buffer
shielding for the Borexino solar neutrino detector was performed with a system
that combined distillation, water extraction, gas stripping and filtration. The
purification of the scintillator achieved unprecedented low backgrounds for the
large scale liquid scintillation detector. This paper describes the principles
of operation, design, construction and commissioning of the purification
system, and reviews the requirements and methods to achieve system cleanliness
and leak-tightness.


title: Maximum Entropy, Time Series and Statistical Inference

abstract:
  A brief discussion is given of the traditional version of the Maximum Entropy
Method, including a review of some of the criticism that has been made in
regard to its use in statistical inference. Motivated by these questions, a
modified version of the method is proposed and applied to a simple problem,
demonstrating its use in inference.


title: The Higgs Decay Width in Multi-Scalar Doublet Models

abstract:
  We show that there are regions of parameter space in multi-scalar doublet
models where, in the first few hundred inverse femtobarns of data, the new
charged and neutral scalars are not directly observable at the LHC and yet the
Higgs decay rate to b bbar is changed significantly from its standard model
value. For a light Higgs with a mass less than 140 GeV, this can cause a large
change in the number of two photon and tau tau Higgs decay events expected at
the LHC compared to the minimal standard model. In the models we consider, the
principle of minimal flavor violation is used to suppress flavor changing
neutral currents. This paper emphasizes the importance of measuring the
properties of the Higgs boson at the LHC; for a range of parameters the model
considered has new physics at the TeV scale that is invisible, in the first few
hundred inverse femtobarns of integrated luminosity at the LHC, except
indirectly through the measurement of Higgs boson properties.


title:
On the asymptotic of likelihood ratios for self-normalized large
  deviations

abstract:
  Motivated by multiple statistical hypothesis testing, we obtain the limit of
likelihood ratio of large deviations for self-normalized random variables,
specifically, the ratio of $P(\sqrt{n}(\bar X +d/n) \ge x_n V)$ to
$P(\sqrt{n}\bar X \ge x_n V)$, as $n\toi$, where $\bar X$ and $V$ are the
sample mean and standard deviation of iid $X_1, ..., X_n$, respectively, $d>0$
is a constant and $x_n \toi$. We show that the limit can have a simple form
$e^{d/z_0}$, where $z_0$ is the unique maximizer of $z f(x)$ with $f$ the
density of $X_i$. The result is applied to derive the minimum sample size per
test in order to control the error rate of multiple testing at a target level,
when real signals are different from noise signals only by a small shift.


title: Surgery description of colored knots

abstract:
  The pair (K,r) consisting of a knot K and a surjective map r from the knot
group onto a dihedral group is said to be a p-colored knot. D. Moskovich
conjectured that for any odd prime p there are exactly p equivalence classes of
p-colored knots up to surgery along unknots in the kernel of the coloring. We
show that there are at most 2p equivalence classes. This is a vast improvement
upon the previous results by Moskovich for p=3, and 5, with no upper bound
given in general. T. Cochran, A. Gerges, and K. Orr, in "Dehn surgery
equivalence relations of 3-manifolds", define invariants of the surgery
equivalence class of a closed 3-manifold M in the context of bordisms. By
taking M to be 0-framed surgery of the 3-sphere along K we may define
Moskovich's colored untying invariant in the same way as the Cochran-Gerges-Orr
invariants. This bordism definition of the colored untying invariant will be
then used to establish the upper bound.


title: The Bizarre Spectral Variability of Central Stars of Planetary Nebulae

abstract:
  A radial velocity (RV) survey to detect central stars in binary systems was
carried out between 2002 and 2004. De Marco et al. (2004) reported that 10 out
of 11 monitored stars exhibited strong RV variability, but periods were not
detected. Since other mechanisms, such as wind variability, can cause apparent
RV variations, we monitored 4 of the 10 RV-variable stars at echelle
resolutions to determine the origin of the variability. Although RV changes are
confirmed for all four stars, none of them can be ascribed to binarity at this
time. However, only for IC4593 is wind variability able to explain most (though
not all) spectral variability. For BD+332642, no wind and no pulsations appear
to be the origin of the RV changes. Finally, M1-77 and M2-54, both known to be
irregular photometric variables, exhibit dramatic RV and line shape variability
of the hydrogen and HeI absorption lines, as well as large RV variability of
weaker lines, which do not change in shape. There is no satisfactory
explanation of this variability, though a combination of wind variability and
pulsations is still the best guess at what makes these stars so variable. We
suggest that luminous central stars are ill suited to detect spectroscopic
binaries, because winds (and possibly pulsations) are pervasive and would mask
even strong periodicities. It it likely that a sample of intrinsically faint
central stars would more readily yield binary information.


title:
On well-posedness of the linear Cauchy problem with the distributional
  right-hand side and discontinuous coefficients

abstract:
  We prove the well-posedness of the Cauchy problem for the linear differential
system of the form $x^{\prime}-A(t)x=f$, where $f$ is a distribution and $A$
possesses at most first-kind discontinuities together with all its derivatives
defined almost everywhere. The left-hand side of this system contains the
product of a distribution and, in general, a discontinuous function, which is
undefined in the classical space of the distributions with the smooth test
functions $\mathcal D'$, so the Cauchy problem has no solution in $\mathcal
D'$. In what follows, we cosider this system in the space of distributions with
the discontinuous test functions, whose elements admit continuous and
associative multiplication by functions possessing at most first-kind
discontinuities (together with all their derivatives defined almost
everywhere), and show that there exists the unique solution of the Cauchy
problem which depends continuously on $f$.


title:
The Most Dark Matter Dominated Galaxies: Predicted Gamma-ray Signals
  from the Faintest Milky Way Dwarfs

abstract:
  We use kinematic data from three new, nearby, extremely low-luminosity Milky
Way dwarf galaxies (Ursa Major II, Willman 1, and Coma Berenices) to constrain
the properties of their dark matter halos, and from these make predictions for
the gamma-ray flux from annihilation of dark matter particles in these halos.
We show that these 10^3 solar luminosity dwarfs are the most dark matter
dominated galaxies in the Universe, with total masses within 100 pc in excess
of 10^6 solar masses. Coupled with their relative proximity, their large masses
imply that they should have mean gamma-ray fluxes comparable to or greater than
any other known satellite galaxy of the Milky Way. Our results are robust to
both variations of the inner slope of the density profile and the effect of
tidal interactions. The fluxes could be boosted by up to two orders of
magnitude if we include the density enhancements caused by surviving dark
matter substructure.


title:
Competition between attractive and repulsive interactions in
  two-component Bose-Einstein condensates trapped in an optical lattice

abstract:
  We consider effects of inter-species attraction on two-component gap solitons
(GSs) in the binary BEC with intra-species repulsion, trapped in the
one-dimensional optical lattice (OL). Systematic simulations of the coupled
Gross-Pitaevskii equations (GPEs) corroborate an assumption that, because the
effective mass of GSs is negative, the inter-species attraction may
\emph{split} the two-component soliton. Two critical values, $\kappa_{1} $ and
$\kappa_{2}$, of the OL strength ($\kappa $) are identified. Two-species GSs
with fully overlapping wave functions are stable in strong lattices ($\kappa
>\kappa_{1}$). In an intermediate region, $\kappa_{1}>\kappa >\kappa_{2}$, the
soliton splits into a double-humped state with separated components. Finally,
in weak lattices ($\kappa <\kappa_{2}$%), the splitting generates a pair of
freely moving single-species GSs. We present and explain the dependence of
$\kappa_{1}$ and $\kappa_{2}$ on thenumber of atoms (total norm), and on the
relative strength of the competing inter-species attraction and intra-species
repulsion. The splitting of asymmetric solitons, with unequal norms of the two
species, is briefly considered too. It is found and explained that the
splitting threshold grows with the increase of the asymmetry.


title:
The effect of the motion of the Sun on the light-time in interplanetary
  relativistic experiments

abstract:
  In 2002 a measurement of the effect of solar gravity upon the phase of
coherent microwave beams passing near the Sun has been carried out with the
Cassini mission, allowing a very accurate measurement of the PPN parameter
$\gamma$. The data have been analyzed with NASA's Orbit Determination Program
(ODP) in the Barycentric Celestial Reference System, in which the Sun moves
around the centre of mass of the solar system with a velocity $v_\odot$ of
about 10 m/sec; the question arises, what correction this implies for the
predicted phase shift. After a review of the way the ODP works, we set the
problem in the framework of Lorentz (and Galilean) transformations and evaluate
the correction; it is several orders of magnitude below our experimental
accuracy. We also discuss a recent paper \cite{kopeikin07}, which claims wrong
and much larger corrections, and clarify the reasons for the discrepancy.


title:
CMB Polarization Systematics Due to Beam Asymmetry: Impact on
  Inflationary Science

abstract:
  CMB polarization provides a unique window into cosmological inflation; the
amplitude of the B-mode polarization from last scattering is uniquely sensitive
to the energetics of inflation. However, numerous systematic effects arising
from optical imperfections can contaminate the observed B-mode power spectrum.
In particular, systematic effects due to the coupling of the underlying
temperature and polarization fields with elliptical or otherwise asymmetric
beams yield spurious systematic signals. This paper presents a non-perturbative
analytic calculation of some of these signals. We show that results previously
derived in real space can be generalized, formally, by including infinitely
many higher-order corrections to the leading order effects. These corrections
can be summed and represented as analytic functions when a fully Fourier-space
approach is adopted from the outset. The formalism and results presented in
this paper were created to determine the susceptibility of CMB polarization
probes of the primary gravitational wave signal but can be easily extended to
the analysis of gravitational lensing of the CMB.


title: On differentiability of the Parisi formula

abstract:
  It was proved by Michel Talagrand in [10] that the Parisi formula for the
free energy in the Sherrington-Kirkpatrick model is differentiable with respect
to inverse temperature parameter. We present a simpler proof of this result by
using approximate solutions in the Parisi formula and give one example of
application of the differentiability to prove non self-averaging of the overlap
outside of the replica symmetric region.


title:
Azumaya-type noncommutative spaces and morphisms therefrom: Polchinski's
  D-branes in string theory from Grothendieck's viewpoint

abstract:
  We explain how Polchinski's work on D-branes re-read from a noncommutative
version of Grothendieck's equivalence of local geometries and function rings
gives rise to an intrinsic prototype definition of D-branes (of B-type) as an
Azumaya-type noncommutative space. Several originally open-string induced
properties of D-branes can be reproduced solely by this intrinsic definition.
We study also the moduli space of D0-branes on a commutative target space in
this setup. Some of its features resembles gas of D0-branes in Vafa's work.


title: On Universal Prediction and Bayesian Confirmation

abstract:
  The Bayesian framework is a well-studied and successful framework for
inductive reasoning, which includes hypothesis testing and confirmation,
parameter estimation, sequence prediction, classification, and regression. But
standard statistical guidelines for choosing the model class and prior are not
always available or fail, in particular in complex situations. Solomonoff
completed the Bayesian framework by providing a rigorous, unique, formal, and
universal choice for the model class and the prior. We discuss in breadth how
and in which sense universal (non-i.i.d.) sequence prediction solves various
(philosophical) problems of traditional Bayesian sequence prediction. We show
that Solomonoff's model possesses many desirable properties: Strong total and
weak instantaneous bounds, and in contrast to most classical continuous prior
densities has no zero p(oste)rior problem, i.e. can confirm universal
hypotheses, is reparametrization and regrouping invariant, and avoids the
old-evidence and updating problem. It even performs well (actually better) in
non-computable environments.

categories: math.ST cs.IT cs.LG math.IT stat.ML stat.TH


title:
Possible theoretical limits on holographic quintessence from weak
  gravity conjecture

abstract:
  The holographic dark energy model is one of the important ways for dealing
with the dark energy problems in the quantum gravity framework. In this model,
the dimensionless parameter $c$ plays an essential role in determining the
evolution of the holographic dark energy. In particular, the holographic dark
energy with $c\geq 1$ can be effectively described by a quintessence
scalar-field. However, according to the requirement of the weak gravity
conjecture the variation of the quintessence scalar-field should be less than
the Planck mass, which would give theoretic constraints on the parameters $c$
and $\Omega_{\mathrm{m0}}$. Therefore, we get the possible theoretical limits
on the parameter $c$ for the holographic quintessence model.


title: Scaling Properties of Fidelity in Spin-one Anisotropic Model

abstract:
  By means of the density matrix renormalization group technique, the scaling
relation of the fidelity susceptibility proposed recently is verified for the
spin-one XXZ spin chain with an on-site anisotropic term. Moreover, from the
results of both the fidelity susceptibility and the entanglement entropy, the
critical points and some of the corresponding critical exponents are determined
through a proper finite-size scaling analysis, and these values agree with the
findings in the literature. Thus our work provides a numerical support of the
use of the fidelity in detecting quantum phase transitions.


title:
Transport properties and magnetic field induced localization in the
  misfit cobaltite
  [Bi$_2$Ba$_{1.3}$K$_{0.6}$Co$_{0.1}$]$^{RS}$[CoO$_2$]$_{1.97}$ single crystal

abstract:
  Resistivity under magnetic field, thermopower and Hall coefficient are
systematically studied for
[Bi$_2$Ba$_{1.3}$K$_{0.6}$Co$_{0.1}$]$^{RS}$[CoO$_2$]$_{1.97}$ single crystal.
In-plane resistivity ($\rho_{ab}$(T)) shows metallic behavior down to 2 K with
a $T^2$ dependence below 30 K; while out-of-plane resistivity ($\rho_{c}(T)$)
shows metallic behavior at high temperature and a thermal activation
semiconducting behavior below about 12 K. Striking feature is that magnetic
field induces a ln(1/$T$) diverging behavior in both $\rho_{ab}$ and
$\rho_{c}(T)$ at low temperature. The positive magnetoresistance (MR) could be
well fitted by the formula based on multi-band electronic structure. The
ln(1/$T$) diverging behavior in $\rho_{ab}$ and $\rho_{c}(T)$ could arise from
the magnetic-field-induced 2D weak localization or spin density wave.


title: Fermions in gravity and gauge backgrounds on a brane world

abstract:
  We solve the fermionic zero modes in gravity and gauge backgrounds on a brane
involving a warped geometry, and study the localization of spin 1/2 fermionic
field on the brane world. The result is that there exist massless spin 1/2
fermions which can be localized on the bulk with the exponentially decreasing
warp factor if including U(1) gauge background. Two special cases of gauge
backgrounds on the extra dimensional manifold are discussed.


title: Ricci Flow with hyperbolic warped product metrics

abstract:
  In this short note, we show that the negative curvature is preserved in the
deformation of hyperbolic warped product metrics under Ricci flow. It is also
showed that the flow converges to a flat metric as time going to infinity.


title:
The BV Master Equation for the Wilson Action in general Yang-Mills Gauge
  Theory

abstract:
  The Wilson effective action for general Yang-Mills gauge theory is shown to
satisfy the usual form of Batalin-Vilkovisky (BV) master equation, despite that
a momentum cutoff apparently breaks the gauge invariance. In the case of
Abelian gauge theory, in particular, it actually deduces the Ward-Takahashi
identity for Wilson action recently derived by Sonoda.


title: String Theory and Quantum Chromodynamics

abstract:
  I review recent progress on the connection between string theory and quantum
chromodynamics in the context of the gauge/gravity duality. Emphasis is placed
on conciseness and conceptual aspects rather than on technical details. Topics
covered include the large-Nc limit of gauge theories, the gravitational
description of gauge theory thermodynamics and hydrodynamics, and
confinement/deconfinement thermal phase transitions.


title: Sfermion Mass Relations in Orbifold Family Unification

abstract:
  We derive relations among sfermion masses based on orbifold family
unification models. Sfermion mass relations are specific to each model and can
be useful for a selection of realistic model.


title: Tensor representations of classical locally finite Lie algebras

abstract:
  We study the structure of tensor representations of the classical
infinite-dimensional locally finite Lie algebras $gl_\infty$, $sl_\infty$,
$sp_\infty$ and $so_\infty$. In contrast with the finite-dimensional case,
these tensor representations are not semisimple. We explicitly describe their
Jordan-Holder constituents, socle filtrations, and indecomposable direct
summands.


title: Jarlskog Invariant of the Neutrino Mapping Matrix

abstract:
  The Jarlskog Invariant $J_{\nu-map}$ of the neutrino mapping matrix is
calculated based on a phenomenological model which relates the smallness of
light lepton masses $m_e$ and $m_1$ (of $\nu_1$) with the smallness of $T$
violation. For small $T$ violating phase $\chi_l$ in the lepton sector,
$J_{\nu-map}$ is proportional to $\chi_l$, but $m_e$ and $m_1$ are proportional
to $\chi_l^2$. This leads to $ J_{\nu-map} \cong
{1/6}\sqrt{\frac{m_e}{m_\mu}}+O \bigg(\sqrt{\frac{m_em_\mu}{m_\tau^2}}\bigg)+O
\bigg(\sqrt{\frac{m_1m_2}{m_3^2}}\bigg)$. Assuming
$\sqrt{\frac{m_1m_2}{m_3^2}}<<\sqrt{\frac{m_e}{m_\mu}}$, we find
$J_{\nu-map}\cong 1.16\times 10^{-2}$, consistent with the present experimental
data.


title:
Origin of Chromatic Features in Multiple Quasars -Variability, Dust, or
  Microlensing -

abstract:
  Aims:In some of the lensed quasars, color differences between multiple images
are observed at optical/near-infrared wavelengths. There are three possible
origins of the color differences: intrinsic variabilities of quasars,
differential dust extinction, and quasar microlensing. We examine how these
three possible scenarios can reproduce the observed chromaticity. Methods:We
evaluate how much color difference between multiple images can be reproduced by
the above three possible scenarios with realistic models; (i) an empirical
relation for intrinsic variabilities of quasars, (ii) empirical relations for
dust extinction and theoretically predicted inhomogeneity in galaxies, or (iii)
a theoretical model for quasar accretion disks and magnification patterns in
the vicinity of caustics. Results:We find that intrinsic variabilities of
quasars cannot be a dominant source responsible for observed chromatic features
in multiple quasars. In contrast, either dust extinction or quasar microlensing
can nicely reproduce the observed color differences between multiple images in
most of the lensed quasars. Taking into account the time interval between
observations at different wavebands in our estimations, quasar microlensing is
a more realistic scenario to reproduce the observed color differences than dust
extinction. All the observed color differences presented in this paper can be
explained by a combination of these two effects, but monitoring observations at
multiple wavebands are necessary to disentangle these.


title:
Multiwavelength Observations of the Powerful Gamma-ray Quasar PKS
  1510-089: Clues on the Jet Composition

abstract:
  We present the results from a multiwavelength campaign of the powerful
Gamma-ray quasar PKS 1510-089. This campaign commenced with a deep Suzaku
observation lasting three days for a total exposure time of 120 ks, and
continued with Swift monitoring over 18 days. Besides Swift observations, the
campaign included ground-based optical and radio data, and yielded a
quasi-simultaneous broad-band spectral energy distribution from 10^9 Hz to
10^{19} Hz. The Suzaku observation provided a high S/N X-ray spectrum, which is
well represented by an extremely hard power-law with photon index Gamma ~ 1.2,
augmented by a soft component apparent below 1 keV, which is well described by
a black-body model with temperature kT ~ 0.2 keV. Monitoring by Suzaku revealed
temporal variability which is different between the low and high energy bands,
again suggesting the presence of a second, variable component in addition to
the primary power-law emission.We model the broadband spectrum of PKS 1510-089
assuming that the high energy spectral component results from Comptonization of
infrared radiation produced by hot dust located in the surrounding molecular
torus. In the adopted internal shock scenario, the derived model parameters
imply that the power of the jet is dominated by protons but with a number of
electrons/positrons exceeding a number of protons by a factor ~10. We also find
that inhomogeneities responsible for the shock formation, prior to the
collision may produce bulk-Compton radiation which can explain the observed
soft X-ray excess and possible excess at ~18 keV. We note, however, that the
bulk-Compton interpretation is not unique, and the observed soft excess could
arise as well via some other processes discussed briefly in the text.


title: The Existence of Pure Free Resolutions

abstract:
  Let d1,...,dn be a strictly increasing sequence of integers. Boij and
S\"oderberg [arXiv:math/0611081] have conjectured the existence of a graded
module M of finite length over any polynomial ring K[x_1,..., x_n], whose
minimal free resolution is pure of type (d1,...,dn), in the sense that its i-th
syzygies are generated in degree di.
  In this paper we prove a stronger statement, in characteristic zero: Such
modules not only exist, but can be taken to be GL(n)-equivariant. In fact, we
give two different equivariant constructions, and we construct pure resolutions
over exterior algebras and Z/2-graded algebras as well.
  The constructions use the combinatorics of Schur functors and Bott's Theorem
on the direct images of equivariant vector bundles on Grassmann varieties.


title:
Application of spectral methods for high-frequency financial data to
  quantifying states of market participants

abstract:
  Empirical analysis of the foreign exchange market is conducted based on
methods to quantify similarities among multi-dimensional time series with
spectral distances introduced in [A.-H. Sato, Physica A, 382 (2007) 258--270].
As a result it is found that the similarities among currency pairs fluctuate
with the rotation of the earth, and that the similarities among best quotation
rates are associated with those among quotation frequencies. Furthermore it is
shown that the Jensen-Shannon spectral divergence is proportional to a mean of
the Kullback-Leibler spectral distance both empirically and numerically. It is
confirmed that these spectral distances are connected with distributions for
behavioral parameters of the market participants from numerical simulation.
This concludes that spectral distances of representative quantities of
financial markets are related into diversification of behavioral parameters of
the market participants.


title: Scaling analysis of FLIC fermion actions

abstract:
  The Fat Link Irrelevant Clover (FLIC) fermion action is a variant of the
$O(a)$-improved Wilson action where the irrelevant operators are constructed
using smeared links. While the use of such smearing allows for the use of
highly improved definitions of the field strength tensor $F_{\mu\nu},$ we show
that the standard 1-loop clover term with a mean field improved coefficient
$c_{\rm sw}$ is sufficient to remove the $O(a)$ errors, avoiding the need for
non-perturbative tuning. This result enables efficient dynamical simulations in
QCD with the FLIC fermion action.


title: Asymptotic Spectroscopy of Rotating Black Holes

abstract:
  We calculate analytically the transmission and reflection amplitudes for
waves incident on a rotating black hole in d=4, analytically continued to
asymptotically large, nearly imaginary frequency. These amplitudes determine
the asymptotic resonant frequencies of the black hole, including quasinormal
modes, total-transmission modes and total-reflection modes. We identify these
modes with semiclassical bound states of a one-dimensional Schrodinger
equation, localized along contours in the complexified r-plane which connect
turning points of corresponding null geodesics. Each family of modes has a
characteristic temperature and chemical potential. The relations between them
provide hints about the microscopic description of the black hole in this
asymptotic regime.


title: Bright continuous-variable entanglement from the quantum optical dimer

abstract:
  We show theoretically that two evanescently coupled $\chi^{(2)}$ second
harmonic generators inside a Fabry-Perot cavity provide a tunable source of
quadrature squeezed light, Einstein-Podolsky-Rosen correlations and quantum
entanglement. Unlike systems using coupled downconverters, second harmonic
generation has no oscillation threshhold, so that the entangled fields become
macroscopically occupied as soon as the pumping fields are turned on. This
system also gives two frequencies at which the entangled fields can have
macroscopic intensity. We show how the entanglement properties can be
controlled by adjusting the pumping, the coupling strengths and the cavity
detunings.


title: Rigidity and percolation of center vortices

abstract:
  Effective action of center vortices in SU(2) lattice gauge theory is
investigated by studying the correlation between the action density on their
worldsheets and their geometric properties. It turns out that center vortices
are rigid, however, their dynamics is more complicated than that of rigid
random surfaces, since some coupling constants have nonstandard scaling
dimensions. As a result, the properties of center vortices are almost
completely determined by curvature-dependent effects. This, in turn, provides a
qualitative explanation of vortex percolation.


title:
Comments on "The Coronal Heating Paradox" by M.J. Aschwanden, A.
  Winebarger, D. Tsiklauri and H. Peter [2007, Astrophys J., 659, 1673]

abstract:
  We point out the priority of our paper (Mahajan et al. 2001, Phys. Plasmas,
8, 1340) over (Aschwanden et al. 2007, Astrophys J., 659, 1673) in introducing
the term "Formation and primary heating of the solar corona" working out
explicit models (theory as well as simulation) for coronal structure formation
and heating. On analyzing the Aschwanden et al. (2007) scenario of coronal
heating process (shifted to the chromospheric heating) we stress, that for
efficient loop formation, the primary upflows of plasma in
chromosphere/transition region should be relatively cold and fast (as opposed
to hot). It is during trapping and accumulation in closed field structures,
that the flows thermalize (due to the dissipation of the short scale flow
energy) leading to a bright and hot coronal structure. The formation and
primary heating of a closed coronal structure (loop at the end) are
simultaneous and a process like the "filling of the empty coronal loop by hot
upflows" is purely speculative and totally unlikely.


title:
Influence of deterministic trend on the estimated parameters of
  GARCH(1,1) model

abstract:
  The log returns of financial time series are usually modeled by means of the
stationary GARCH(1,1) stochastic process or its generalizations which can not
properly describe the nonstationary deterministic components of the original
series. We analyze the influence of deterministic trends on the GARCH(1,1)
parameters using Monte Carlo simulations. The statistical ensembles contain
numerically generated time series composed by GARCH(1,1) noise superposed on
deterministic trends. The GARCH(1,1) parameters characteristic for financial
time series longer than one year are not affected by the detrending errors. We
also show that if the ARCH coefficient is greater than the GARCH coefficient,
then the estimated GARCH(1,1) parameters depend on the number of monotonic
parts of the trend and on the ratio between the trend and the noise amplitudes.


title:
Asymptotic Behaviour of Parameter Ideals in Generalized Cohen-Macaulay
  Modules

abstract:
  The purpose of this paper is to give affirmative answers to two open
questions as follows. Let $(R, \m)$ be a generalized Cohen-Macaulay Noetherian
local ring. Both questions, the first question was raised by M. Rogers \cite
{R} and the second one is due to S. Goto and H. Sakurai \cite {GS1}, ask
whether for every parameter ideal $\q$ contained in a high enough power of the
maximal ideal $\m $ the following statements are true: (1) The index of
reducibility $N_R(\q;R)$ is independent of the choice of $\q$; and (2) $I^2=\q
I$, where $I=\q:_R\m$.


title:
Representing complex data using localized principal components with
  application to astronomical data

abstract:
  Often the relation between the variables constituting a multivariate data
space might be characterized by one or more of the terms: ``nonlinear'',
``branched'', ``disconnected'', ``bended'', ``curved'', ``heterogeneous'', or,
more general, ``complex''. In these cases, simple principal component analysis
(PCA) as a tool for dimension reduction can fail badly. Of the many alternative
approaches proposed so far, local approximations of PCA are among the most
promising. This paper will give a short review of localized versions of PCA,
focusing on local principal curves and local partitioning algorithms.
Furthermore we discuss projections other than the local principal components.
When performing local dimension reduction for regression or classification
problems it is important to focus not only on the manifold structure of the
covariates, but also on the response variable(s). Local principal components
only achieve the former, whereas localized regression approaches concentrate on
the latter. Local projection directions derived from the partial least squares
(PLS) algorithm offer an interesting trade-off between these two objectives. We
apply these methods to several real data sets. In particular, we consider
simulated astrophysical data from the future Galactic survey mission Gaia.


title: The Set of Prime Numbers

abstract:
  In this work we show that the prime distribution is deterministic. Indeed the
set of prime numbers P can be expressed in terms of two subsets of N using
three specific selection rules, acting on two sets of prime candidates. The
prime candidates are obtained in terms of the first perfect number. The
asymptotic behaviour is also considered.
  We obtain for the first time an explicit relation for generating the full set
P of prime numbers smaller than n or equal to n.


title: A dynamic density functional theory for particles in a flowing solvent

abstract:
  We present a dynamic density functional theory (dDFT) which takes into accou
nt the advection of the particles by a flowing solvent. For potential flows we
can use the same closure as in the absence of solvent flow. The structure of
the resulting advected dDFT suggests that it could be used for non-potential
flows as well. We apply this dDFT to Brownian particles (e.g., polymer coils)
in a solvent flowing around a spherical obstacle (e.g., a colloid) and compare
the results with direct simulations of the underlying Brownian dynamics.
  Although numerical limitations do not allow for an accurate quantitative
check of the advected dDFT both show the same qualitative features. In contrast
to previous works which neglected the deformation of the flow by the obstacle,
we find that the bow-wave in the density distribution of particles in front of
the obstacle as well as the wake behind it are reduced dramatically. As a
consequence the friction force exerted by the (polymer) particles on the
colloid can be reduced drastically.


title:
Propagation of high-energy cosmic rays in extragalactic turbulent
  magnetic fields: resulting energy spectrum and composition

abstract:
  We extend previous studies of mixed-composition extragalactic cosmic-ray
source models, by investigating the influence of a non-negligible extragalactic
magnetic field on the propagated cosmic-ray spectrum and composition. We study
the transport of charged particles in turbulent fields and the transition from
a ballistic to a diffusive propagation regime. We introduce a method allowing a
fast integration of the particle trajectories, which allows us to calculate
extragalactic cosmic-ray spectra in the general case, without using either the
diffusive or the rectilinear approximation. We find that the main features of
the mixed-composition models -- regarding the interpretation of the ankle and
the non-monotonous evolution of the average cosmic-ray mass -- remain
essentially unchanged as long as the magnetic field intensity does not exceed a
few nG.


title: Coherent single atom shuttle between two Bose-Einstein condensates

abstract:
  We study an atomic quantum dot representing a single hyperfine "impurity"
atom which is coherently coupled to two well-separated Bose-Einstein
condensates, in the limit when the coupling between the dot and the condensates
dominates the inter-condensate tunneling coupling. It is demonstrated that the
quantum dot by itself can induce large-amplitude Josephson-like oscillations of
the particle imbalance between the condensates, which display a two-frequency
behavior. For noninteracting condensates, we provide an approximate solution to
the coupled nonlinear equations of motion which allows us to obtain these two
frequencies analytically.


title: Kinetic Exchange Models for Income and Wealth Distributions

abstract:
  Increasingly, a huge amount of statistics have been gathered which clearly
indicates that income and wealth distributions in various countries or
societies follow a robust pattern, close to the Gibbs distribution of energy in
an ideal gas in equilibrium. However, it also deviates in the low income and
more significantly for the high income ranges. Application of physics models
provides illuminating ideas and understanding, complementing the observations.

categories: q-fin.GN cond-mat.stat-mech nlin.AO physics.soc-ph


title:
A radiative transfer scheme for cosmological reionization based on a
  local Eddington tensor

abstract:
  A radiative transfer scheme is presented, based on a moment description of
the equation of radiative transfer and the so-called ``M1 closure model'' for
the Eddington tensor. This model features a strictly hyperbolic transport step
for radiation: it has been implemented using standard Godunov--like techniques
in a new code called ATON. Coupled to simple models of ionization chemistry and
photo-heating, ATON is able to reproduce the results of other schemes on a
various set of standard tests such as the expansion of a HII region, the
shielding of the radiation by dense clumps and cosmological ionization by
multiple sources. Being simple yet robust, such a scheme is intended to be
naturally and easily included in grid--based cosmological fluid solvers.


title:
A non-linear dynamical systems approach to source compression for
  constrained sources

abstract:
  We have recently established a strong connection between the Tent map (also
known as Generalized Luroth Series or GLS which is a chaotic, ergodic and
lebesgue measure preserving non-linear dynamical system) and Arithmetic coding
which is a popular source compression algorithm used in international
compression standards such as JPEG2000 and H.264. This was for independent and
identically distributed binary sources. In this paper, we address the problem
of compression of ergodic Markov binary sources with certain words forbidden
from the message space. We shall show that GLS can be modified suitably to
achieve Shannon's entropy rate for these sources.


title: Combinatorics of the Dimer Model on a Strip

abstract:
  In this note, we give a closed formula for the partition function of the
dimer model living on a (2 x n) strip of squares or hexagons on the torus for
arbitrary even n. The result is derived in two ways, by using a Potts model
like description for the dimers, and via a recursion relation that was obtained
from a map to a 1D monomer-dimer system. The problem of finding the number of
perfect matchings can also be translated to the problem of finding a minmal
feedback arc set on the dual graph.


title:
Finite Temperature Large N Gauge Theory with Quarks in an External
  Magnetic Field

abstract:
  Using a ten dimensional dual string background, we study aspects of the
physics of finite temperature large N four dimensional SU(N) gauge theory,
focusing on the dynamics of fundamental quarks in the presence of a background
magnetic field. At vanishing temperature and magnetic field, the theory has N=2
supersymmetry, and the quarks are in hypermultiplet representations. In a
previous study, similar techniques were used to show that the quark dynamics
exhibit spontaneous chiral symmetry breaking. In the present work we begin by
establishing the non-trivial phase structure that results from finite
temperature. We observe, for example, that above the critical value of the
field that generates a chiral condensate spontaneously, the meson melting
transition disappears, leaving only a discrete spectrum of mesons at any
temperature. We also compute several thermodynamic properties of the plasma.


title:
Conductance enhancement due to the resonant tunneling into the subgap
  vortex core states in normal metal/superconductor ballistic junctions

abstract:
  We investigate the low-energy quantum transport in the ballistic normal
metal-insulator -superconductor junction in the presence of magnetic field
creating Abrikosov vortices in the superconductor. Within the Bogolubov- de
Gennes theory we show that the presence of the subgap quasiparticle states
localized within the vortex cores near the junction interface leads to the
strong resonant enhancement of the Andreev reflection probability, and the
normal-to supercurrent conversion. The corresponding increase of the charge
conductance of the junction is determined by the distance from the vortex chain
to the junction interface, which can be controlled by the applied magnetic
field. The effect that we study provides a tool for probing the vortex core
states by the measurements of charge transport across the applied magnetic
field.


title: On the Origin of Rapid Flares in TeV Blazars

abstract:
  The rapid variability of the VHE emission reported for some TeV blazars
implies Doppler factors well in excess of those inferred from superluminal
motions and unification schemes. We propose that those extreme flares may
result from radiative deceleration of blobs on scales where local dissipation
occurs. The minimum jet power estimated from the resolved synchrotron emission
on VLBI scales appears to be consistent with this model. It is shown that if
the energy distribution of nonthermal electrons accelerated locally in the blob
is reasonably flat, then a background radiation field having a luminosity in
the range 10$^{41}-10^{42}$ erg s$^{-1}$ can give rise to a substantial
deceleration of the blob, but still be transparent enough to allow the TeV
$\gamma$-rays thereby produced to escape the system.


title: A particle mechanism for the index of refraction

abstract:
  We propose to go away from the electromagnetic wave description of light and
to explain through a purely corpuscular and neutral approach, the phenomenon of
the slowing down of light in a transparent medium. The quantum predictions and
ours are compared against experimental refractive indices. In our framework the
optical Kerr phenomenon finds a very natural interpretation and its numerical
values are obtained easily


title: AdS/CFT with Flavour in Electric and Magnetic Kalb-Ramond Fields

abstract:
  We investigate gauge/gravity duals with flavour for which pure-gauge
Kalb-Ramond B fields are turned on in the background, into which a D7 brane
probe is embedded. First we consider the case of a magnetic field in two of the
spatial boundary directions. We show that at finite temperature, i.e. in the
AdS-Schwarzschild background, the B field has a stabilizing effect on the
mesons and chiral symmetry breaking occurs for a sufficiently large value of
the B field. Then we turn to the electric case of a B field in the temporal
direction and one spatial boundary direction. In this case, there is a singular
region in which it is necessary to turn on a gauge field on the brane in order
to ensure reality of the brane action. We find that the brane embeddings are
attracted towards this region. Far away from this region, in the weak field
case at zero temperature, we investigate the meson spectrum and find a mass
shift similar to the Stark effect.


title:
Some aspects of infinite range models of spin glasses: theory and
  numerical simulations

abstract:
  These notes give an introduction to the physics of the infinite range version
of the Edwards--Anderson model, the so-called Sherrington--Kirkpatrick model.
In a first part, I motivate and introduce the Edwards--Anderson and
Sherrington--Kirkpatrick models. In the second part, I explain the analytical
solution of the Sherrington--Kirkpatrick model, following Giorgio Parisi. I
next give the physical interpretation of this solution. This is a vast subject,
and I concentrate on the major points and give references for more details. The
third part presents the simulation approach and compare its results to
theoretical expectations: thermodynamics, finite size scaling, determination of
the critical temperature using "parameters" like the "Binder parameter", and
fluctuations. The last part gives a summary of our current understanding of
finite size effects for the free energy and internal energy of the
Sherrington--Kirkpatrick model


title:
Probing Transversity GPDs in Photo and Electroproduction of Two Vector
  Mesons

abstract:
  Electroproduction of two mesons well separated in rapidity allows the first
feasible selective access to chiral-odd transversity GPDs provided one of these
mesons is a transversely polarized vector meson rho_T.


title:
Quarks in an External Electric Field in Finite Temperature Large N Gauge
  Theory

abstract:
  We use a ten dimensional dual string background to aspects of the physics
large N four dimensional SU(N) gauge theory, where its fundamental quarks are
charged under a background electric field. The theory is N=2 supersymmetric for
vanishing temperature and electric field. At zero temperature, we observe that
the electric field induces a phase transition associated with the dissociation
of the mesons into their constituent quarks. This is an analogue of an
insulator-metal transition, since the system goes from being an insulator with
zero current (in the applied field) to a conductor with free charge carriers
(the quarks). At finite temperature this phenomenon persists, with the
dissociation transition become subsumed into the more familiar meson melting
transition. Here, the dissociation phenomenon reduces the critical melting
temperature.


title: Turing structures in dc gas discharges

abstract:
  Self-organized spatial plasma structures exhibit many similarities with
Turing structures obtained in biology and chemistry. Using an analytical
mesoscopic approach it is shown that plasma balls of fire belong to the same
class of Turing structures like the Brusselator. It is also mathematically
proved that the existence of these self-organized plasma structures is related
with a negative differential resistance. There are also established the
mathematical conditions which the negative differential resistance must satisfy
for obtaining a stationary ball of fire at the anode of a plasma diode.


title:
Approximation of complex algebraic numbers by algebraic numbers of
  bounded degree

abstract:
  We investigate how well complex algebraic numbers can be approximated by
algebraic numbers of degree at most n. We also investigate how well complex
algebraic numbers can be approximated by algebraic integers of degree at most
n+1. It follows from our investigations that for every positive integer n there
are complex algebraic numbers of degree larger than n that are better
approximable by algebraic numbers of degree at most n than almost all complex
numbers. As it turns out, these numbers are more badly approximable by
algebraic integers of degree at most n+1 than almost all complex numbers.


title: The Szemeredi property in ergodic W*-dynamical systems

abstract:
  We study weak mixing of all orders for asymptotically abelian weakly mixing
state preserving C*-dynamical systems, where the dynamics is given by the
action of an abelian second countable locally compact group which contains a
Folner sequence satisfying the Tempelman condition. For a smaller class of
groups (which include Z^q and R^q) this is then used to show that an
asymptotically abelian ergodic W*-dynamical system either has the "Szemeredi
property" or contains a nontrivial subsystem (a "compact factor") that does. A
van der Corput lemma for Hilbert space valued functions on the group is one of
our main technical tools.


title: Global phase-locking in finite populations of phase-coupled oscillators

abstract:
  We present new necessary and sufficient conditions for the existence of fixed
points in a finite system of coupled phase oscillators on a complete graph. We
use these conditions to derive bounds on the critical coupling.


title: Koppelman formulas on Grassmannians

abstract:
  We construct Koppelman formulas on Grassmannians for forms with values in any
holomorphic line bundle as well as in the tautological vector bundle and its
dual. As a consequence we obtain some vanishing theorems of the Bott-Borel-Weil
type. We also relate the projection part of our formulas to the Bergman kernels
associated to the line bundles.


title: On two notions of complexity of algebraic numbers

abstract:
  we derive new, improved lower bounds for the block complexity of an
irrational algebraic number and for the number of digit changes in the b-ary
expansion of an irrational algebraic number. To this end, we apply a
quantitative version of the Subspace Theorem due to Evertse and Schlickewei
(2002).


title: Calibration of the galaxy cluster M_500-Y_X relation with XMM-Newton

abstract:
  The quantity Y_ X, the product of the X-ray temperature T_ X and gas mass M_
g, has recently been proposed as a robust low-scatter mass indicator for galaxy
clusters. Using precise measurements from XMM-Newton data of a sample of 10
relaxed nearby clusters, spanning a Y_ X range of 10^13 -10^15 M_sun keV, we
investigate the M_500-Y_ X relation. The M_500 - Y_ X data exhibit a power law
relation with slope alpha=0.548 \pm 0.027, close to the self-similar value
(3/5) and independent of the mass range considered. However, the normalisation
is \sim 20% below the prediction from numerical simulations including cooling
and galaxy feedback. We discuss two effects that could contribute to the
normalisation offset: an underestimate of the true mass due to the HE
assumption used in X-ray mass estimates, and an underestimate of the hot gas
mass fraction in the simulations. A comparison of the functional form and
scatter of the relations between various observables and the mass suggest that
Y_ X may indeed be a better mass proxy than T_ X or M_g,500.


title:
Transport of interacting electrons through a potential barrier:
  nonperturbative RG approach

abstract:
  We calculate the linear response conductance of electrons in a Luttinger
liquid with arbitrary interaction g_2, and subject to a potential barrier of
arbitrary strength, as a function of temperature. We first map the Hamiltonian
in the basis of scattering states into an effective low energy Hamiltonian in
current algebra form. Analyzing the perturbation theory in the fermionic
representation the diagrams contributing to the renormalization group (RG)
\beta-function are identified. A universal part of the \beta-function is given
by a ladder series and summed to all orders in g_2. First non-universal
corrections beyond the ladder series are discussed. The RG-equation for the
temperature dependent conductance is solved analytically. Our result agrees
with known limiting cases.


title:
Blind Multi-Band Signal Reconstruction: Compressed Sensing for Analog
  Signals

abstract:
  We address the problem of reconstructing a multi-band signal from its
sub-Nyquist point-wise samples. To date, all reconstruction methods proposed
for this class of signals assumed knowledge of the band locations. In this
paper, we develop a non-linear blind perfect reconstruction scheme for
multi-band signals which does not require the band locations. Our approach
assumes an existing blind multi-coset sampling method. The sparse structure of
multi-band signals in the continuous frequency domain is used to replace the
continuous reconstruction with a single finite dimensional problem without the
need for discretization. The resulting problem can be formulated within the
framework of compressed sensing, and thus can be solved efficiently using known
tractable algorithms from this emerging area. We also develop a theoretical
lower bound on the average sampling rate required for blind signal
reconstruction, which is twice the minimal rate of known-spectrum recovery. Our
method ensures perfect reconstruction for a wide class of signals sampled at
the minimal rate. Numerical experiments are presented demonstrating blind
sampling and reconstruction with minimal sampling rate.


title: Ab-initio self-energy corrections in systems with metallic screening

abstract:
  The calculation of self-energy corrections to the electron bands of a metal
requires the evaluation of the intraband contribution to the polarizability in
the small-q limit. When neglected, as in standard GW codes for semiconductors
and insulators, a spurious gap opens at the Fermi energy. Systematic methods to
include intraband contributions to the polarizability exist, but require a
computationally intensive Fermi-surface integration. We propose a numerically
cheap and stable method, based on a fit of the power expansion of the
polarizability in the small-q region. We test it on the homogeneous electron
gas and on real metals such as sodium and aluminum.


title: Overpartition pairs and two classes of basic hypergeometric series

abstract:
  We study the combinatorics of two classes of basic hypergeometric series. We
first show that these series are the generating functions for certain
overpartition pairs defined by frequency conditions on the parts. We then show
that when specialized these series are also the generating functions for
overpartition pairs with bounded successive ranks, overpartition pairs with
conditions on their Durfee dissection, as well as certain lattice paths. When
further specialized, the series become infinite products, leading to numerous
identities for partitions, overpartitions, and overpartition pairs.


title: Spin polarized current in a junction of zigzag carbon nanotube

abstract:
  We investigated spin-resolved electronic transport through a junction
composed of a nonmagnetic metal electrode and a zigzag carbon nanotube by means
of self-consistent Green's function method in the tight binding approximation
and the unrestricted Hartree-Fock approximation. Our results show that the
electric current can be spin-polarized if the coupling of the junction is weak.
Further calculations on spin-spin correlation and local density of states
reveal the existence of magnetic edge states in zigzag carbon nanotubes, which
is responsible for the observed spin-polarized current and can be controlled by
applying a gate voltage. We also studied the influence of the nearest-neighbor
Coulomb interaction and the junction coupling strength on the spin-polarization
of the current.


title: Quantum graphs and the integer quantum Hall effect

abstract:
  We study the spectral properties of infinite rectangular quantum graphs in
the presence of a magnetic field. We study how these properties are affected
when three-dimensionality is considered, in particular, the chaological
properties. We then establish the quantization of the Hall transverse
conductivity for these systems. This quantization is obtained by relating the
transverse conductivity to topological invariants. The different integer values
of the Hall conductivity are explicitly computed for an anisotropic diffusion
system which leads to fractal phase diagrams.


title:
Automated Calculation Scheme for alpha^n Contributions of QED to Lepton
  g-2: New Treatment of Infrared Divergence for Diagrams without Lepton Loops

abstract:
  We have developed an efficient algorithm for the subtraction of infrared
divergences that arise in the evaluation of QED corrections to the anomalous
magnetic moment of lepton (g-2). By incorporating this new algorithm, we have
extended the automated code-generating system developed previously to deal with
diagrams without internal lepton loops (called q-type), which produced
convergent integrals when applied to diagrams that have only
ultraviolet-divergent subdiagrams of vertex type. The new system produces
finite integrals for all q-type diagrams, including those that contain
self-energy subdiagrams and thus exhibit infrared-divergent behavior. We have
thus far verified the system for the sixth- and eighth-order cases. We are now
evaluating 6354 vertex diagrams of q-type that contribute to the tenth-order
lepton g-2.


title:
Tridiagonal PT-symmetric N by N Hamiltonians and a fine-tuning of their
  observability domains in the strongly non-Hermitian regime

abstract:
  A generic PT-symmetric Hamiltonian is assumed tridiagonalized and truncated
to N dimensions, and its up-down symmetrized special cases with J=[N/2] real
couplings are considered. In the strongly non-Hermitian regime the secular
equation gets partially factorized at all N. This enables us to reveal a
fine-tuned alignment of the dominant couplings implying an asymptotically
sharply spiked shape of the boundary of the J-dimensional quasi-Hermiticity
domain in which all the spectrum of energies remains real and observable.


title: Reciprocal cyclotomic polynomials

abstract:
  Let $\Psi_n(x)$ be the monic polynomial having precisely all non-primitive
$n$th roots of unity as its simple zeros. One has
$\Psi_n(x)=(x^n-1)/\Phi_n(x)$, with $\Phi_n(x)$ the $n$th cyclotomic
polynomial. The coefficients of $\Psi_n(x)$ are integers that like the
coefficients of $\Phi_n(x)$ tend to be surprisingly small in absolute value,
e.g. for $n<561$ all coefficients of $\Psi_n(x)$ are $\le 1$ in absolute value.
We establish various properties of the coefficients of $\Psi_n(x)$.


title:
High-redshift microlensing and the spatial distribution of dark matter
  in the form of MACHOs

abstract:
  A substantial part of the dark matter of the Universe could be in the form of
compact objects (MACHOs), detectable through gravitational microlensing effects
as they pass through the line of sight to background light sources. So far,
most attempts to model the effects of high-redshift microlensing by a
cosmologically distributed population of MACHOs have assumed the compact
objects to be randomly and uniformly distributed along the line of sight. Here,
we present a more realistic model, in which the MACHOs are assumed to follow
the spatial clustering of cold dark matter. Because of sightline-to-sightline
variations in surface mass density, this scenario leads to substantial scatter
in MACHO optical depths, which we quantify as a function of source redshift. We
find that while optical depth estimates based on a uniform line-of-sight
distribution are reasonable for the highest-redshift light sources, such
estimates can be incorrect by a factor of ~2 for the nearby (z~0.25) Universe.
Hence, attempts to derive the cosmological density of MACHOs from microlensing
observations of only a few independent sightlines can be subject to substantial
uncertainties. We also apply this model to the prediction of
microlensing-induced variability in quasars not subject to macrolensing, and
demonstrate that relaxing the assumption of randomly and uniformly distributed
MACHOs only has a modest impact on the predicted light curve amplitudes. This
implies that the previously reported problems with microlensing as the dominant
mechanism for the observed long-term optical variability of quasars cannot be
solved by taking the large-scale clustering of dark matter into account.


title:
Is mass loss along the red giant branch of globular clusters sharply
  peaked? The case of M3

abstract:
  There is a growing evidence that several globular clusters must contain
multiple stellar generations, differing in helium content. This hypothesis has
helped to interpret peculiar unexplained features in their horizontal branches.
In this framework we model the peaked distribution of the RR Lyr periods in M3,
that has defied explanation until now. At the same time, we try to reproduce
the colour distribution of M3 horizontal branch stars. We find that only a very
small dispersion in mass loss along the red giant branch reproduces with good
accuracy the observational data. The enhanced and variable helium content among
cluster stars is at the origin of the extension in colour of the horizontal
branch, while the sharply peaked mass loss is necessary to reproduce the
sharply peaked period distribution of RR Lyr variables. The dispersion in mass
loss has to be <~ 0.003 Msun, to be compared with the usually assumed values of
~0.02 Msun. This requirement represents a substantial change in the
interpretation of the physical mechanisms regulating the evolution of globular
cluster stars.


title:
Quantum simulation of Anderson and Kondo lattices with superconducting
  qubits

abstract:
  We introduce a mapping between a variety of superconducting circuits and a
family of Hamiltonians describing localized magnetic impurities interacting
with conduction bands. This includes the Anderson model, the single impurity
one- and two-channel Kondo problem, as well as the 1D Kondo lattice. We compare
the requirements for performing quantum simulations using the proposed circuits
to those of universal quantum computation with superconducting qubits, singling
out the specific challenges that will have to be addressed.


title: The Active Mirror Control of the MAGIC Telescope

abstract:
  One of the main design goals of the MAGIC telescopes is the very fast
repositioning in case of Gamma Ray Burst (GRB) alarms, implying a low weight of
the telescope dish. This is accomplished by using a space frame made of carbon
fiber epoxy tubes, resulting in a strong but not very rigid support structure.
Therefore it is necessary to readjust the individual mirror tiles to correct
for deformations of the dish under varying gravitational load while tracking an
object. We present the concept of the Active Mirror Control (AMC) as
implemented in the MAGIC telescopes and the actual performance reached.
Additionally we show that also telescopes using a stiff structure can benefit
from using an AMC.


title: Configurational Temperature Control for Atomic and Molecular Systems

abstract:
  A new configurational temperature thermostat suitable for molecules with
holonomic constraints is derived. This thermostat has a simple set of motion
equations, can generate the canonical ensemble in both position and momentum
space, acts homogeneously through the spatial coordinates, and does not
intrinsically violate the constraints. Our new configurational thermostat is
closely related to the kinetic temperature Nose-Hoover thermostat with feedback
coupled to the position variables via a term proportional to the net molecular
force. We validate the thermostat by comparing equilibrium static and dynamic
quantities for a fluid of n-decane molecules under configurational and kinetic
temperature control. Practical aspects concerning the implementation of the new
thermostat in a molecular dynamics code and the potential applications are
discussed.


title: Groups which are not properly 3-realizable

abstract:
  A group is properly 3-realizable if it is the fundamental group of a compact
polyhedron whose universal covering is proper homotopically equivalent to some
3-manifold. We prove that when such a group is also quasi-simply filtered then
it has {\em pro-(finitely generated free) fundamental group at infinity} and
{\em semi-stable ends}. Conjecturally the quasi-simply filtration assumption is
superfluous. Using these restrictions we provide the first examples of finitely
presented groups which are not properly 3-realizable, for instance large
families of Coxeter groups.


title: Analytic Extension of a maximal surface in $\Bbb L^3$ along its boudary

abstract:
  We prove that a maximal surface in Lorentz-Minkowski space $\Bbb L^3$ can be
extended analytically along its boundary if the boundary lies in a plane
meeting the surface at a constant angle.


title:
Intersection homology D-Modules and Bernstein polynomials associated
  with a complete intersection

abstract:
  Let X be a complex analytic manifold. Given a closed subspace $Y\subset X$ of
pure codimension p>0, we consider the sheaf of local algebraic cohomology
$H^p_{[Y]}({\cal O}_X)$, and ${\cal L}(Y,X)\subset H^p_{[Y]}({\cal O}_X)$ the
intersection homology D_X-Module of Brylinski-Kashiwara. We give here an
algebraic characterization of the spaces Y such that L(Y,X) coincides with
$H^p_{[Y]}({\cal O}_X)$, in terms of Bernstein-Sato functional equations.


title:
Dislocation formation from a surface step in semiconductors: an ab
  initio study

abstract:
  The role of a simple surface defect, such as a step, for relaxing the stress
applied to a semiconductor, has been investigated by means of large scale first
principles calculations. Our results indicate that the step is the privileged
site for initiating plasticity, with the formation and glide of 60$^\circ$
dislocations for both tensile and compressive deformations. We have also
examined the effect of surface and step termination on the plastic mechanisms.


title:
Suzaku Detection of Extended/Diffuse Hard X-Ray Emission from the
  Galactic Center

abstract:
  Five on-plane regions within +/- 0.8deg of the Galactic center were observed
with the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS)
onboard Suzaku. From all regions, significant hard X-ray emission was detected
with HXD-PIN up to 40 keV, in addition to the extended plasma emission which is
dominant in the XIS band. The hard X-ray signals are inferred to come primarily
from a spatially extended source, rather than from a small number of bright
discrete objects. Contributions to the HXD data from catalogued X-ray sources,
typically brighter than 1 mCrab, were estimated and removed using information
from Suzaku and other satellites. Even after this removal, the hard X-ray
signals remained significant, exhibiting a typical 12--40 keV surface
brightness of 4E-10 erg cm-2 s-1 deg-2 and power-law-like spectra with a photon
index of 1.8. Combined fittings to the XIS and HXD-PIN spectra confirm that a
separate hard tail component is superposed onto the hot thermal emission,
confirming a previous report based on the XIS data. Over the 5--40 keV band,
the hard tail is spectrally approximated by a power law of photon index ~2, but
better by those with somewhat convex shapes. Possible origins of the extended
hard X-ray emission are discussed.


title:
Stability of undissociated screw dislocations in zinc-blende covalent
  materials from first principle simulations

abstract:
  The properties of perfect screw dislocations have been investigated for
several zinc-blende materials such as diamond, Si, $\beta$-SiC, Ge and GaAs, by
performing first principles calculations. For almost all elements, a core
configuration belonging to shuffle set planes is favored, in agreement with low
temperature experiments. Only for diamond, a glide configuration has the lowest
defect energy, thanks to an sp$^2$ hybridization in the core.


title: Energy dependence of nuclear effects in hadron-nucleus collisions

abstract:
  The energy dependence of light and heavy particle production in
hadron-nucleus collisions is discussed. Whereas the production mechanism at
lower energies can be understood in the Glauber rescattering picture,
experimental data at RHIC indicate that particles are mostly produced in
coherent processes. The importance of energy-momentum conservation is shown to
be crucial at forward rapidities for the whole energy range. We also discuss
the behaviour of $\alpha (x_F)$ with energy for light particles and $J/\psi$.
Finally, we make predictions for the future LHC experiment.


title:
Surface step effects on Si (100) under uniaxial tensile stress, by
  atomistic calculations

abstract:
  This paper reports a study of the influence of the step at a silicon surface
under an uniaxial tensile stress, using an empirical potential. Our aim was to
find conditions leading to nucleation of dislocations from the step. We
obtained that no dislocations could be generated with such conditions. This
behaviour, different from the one predicted for metals, could be attributed
either to the covalent bonding or to the cubic diamond structure.


title:
Can one control systematic errors of QCD sum rule predictions for bound
  states?

abstract:
  We study the possibility to control systematic errors of the ground-state
parameters obtained by Shifman-Vainshtein-Zakharov (SVZ) sum rules, making use
of the harmonic-oscillator potential model as an example. In this case, one
knows the exact solution for the polarization operator, which allows one to
obtain both the OPE to any order and the parameters (masses and decay
constants) of the bound states. We determine the parameters of the ground state
making use of the standard procedures of the method of QCD sum rules, and
compare the obtained results with the known exact values. We show that in the
situation when the continuum contribution to the polarization operator is not
known and is modelled by an effective continuum, the method of sum rules does
not allow to control the systematic errors of the extracted ground-state
parameters.


title: Ab initio Study of Misfit Dislocations at the SiC/Si(001) Interface

abstract:
  The high lattice mismatched SiC/Si(001) interface was investigated by means
of combined classical and ab initio molecular dynamics. Among the several
configurations analyzed, a dislocation network pinned at the interface was
found to be the most efficient mechanism for strain relief. A detailed
description of the dislocation core is given, and the related electronic
properties are discussed for the most stable geometry: we found interface
states localized in the gap that may be a source of failure of electronic
devices.


title: H\to hh in the Mirror Model at the CERN Large Hadron Collider

abstract:
  The Higgs sector may play an important role in detecting the mirror
particles, which can be the candidates of the dark matter and appear as missing
energy in the detectors at the LHC. In this paper we worked out the Higgs boson
spectrum and the Higgs couplings for the symmetric vacuum, namely $v_1=v_2=v$,
in the mirror model, and investigated the constraints from electro-weak
precision observable (EWPO). Our study showed that the EWPO has already
constrained the Higgs boson sector severely. We then explored the Higgs boson
phenomenology, and focused on the scenario that the heavier Higgs boson $H$ can
decay into a pair of lighter Higgs boson $h$. We proposed to study the
invisible decay of the Higgs boson via the pair production of them, in which
one Higgs boson decays into bottom quarks and the other decays invisibly. Our
detail simulation for signals and backgrounds showed that the observation of
signal can reach $5\sigma$ significance for $m_H=260$ GeV and $m_h=115$ GeV
with $10 fb^{-1}$integrated luminosity at the LHC. Moreover the possible method
to further suppress dominant $Zb\bar{b}$ background was discussed. We also
simulated the signals and backgrounds for $H \to h h \to 4b$. Our results
showed that it is very difficult to isolate the signals from huge QCD continuum
backgrounds.


title:
Theory of single atom manipulation with a scanning probe tip: Force
  signatures, constant-height, and constant-force scans

abstract:
  We report theoretical results predicting the atomic manipulation of a silver
atom on a Si(001) surface by a scanning probe tip, and providing insight into
the manipulation phenomena. A molecular mechanics technique has been used, the
system being described by a quantum chemistry method for the short-range
interactions and an analytical model for the long-range ones. Taking into
account several shapes, orientations, and chemical natures of the scanning tip,
we observed four different ways to manipulate the deposited atom in a
constant-height mode. In particular, the manipulation is predicted to be
possible with a Si(111) tip for different tip shapes and adatom locations on
the silicon surface. The calculation of the forces during the manipulation
revealed that specific variations can be associated with each kind of process.
These force signatures, such as the tip height signatures observed in scanning
tunneling microscope experiments, could be used to deduce the process involved
in an experiment. Finally, we present preliminary results about the
manipulation in constant-force mode.


title:
Undissociated screw dislocations in silicon: calculations of core
  structure and energy

abstract:
  The stability of the perfect screw dislocation in silicon has been
investigated using both classical potentials and first-principles calculations.
Although a recent study by Koizumi et al . stated that the stable screw
dislocation was located in both the 'shuffle' and the 'glide' sets of {111}
planes, it is shown that this result depends on the classical potential used,
and that the most stable configuration belongs to the 'shuffle' set only, in
the centre of one hexagon. We also investigated the stability of an sp 2
hybridization in the core of the dislocation, obtained for one metastable
configuration in the 'glide' set. The core structures are characterized in
several ways, with a description of the three-dimensional structure,
differential displacement maps and derivatives of the disregistry.


title:
American Options under Proportional Transaction Costs: Pricing, Hedging
  and Stopping Algorithms for Long and Short Positions

abstract:
  American options are studied in a general discrete market in the presence of
proportional transaction costs, modelled as bid-ask spreads. Pricing algorithms
and constructions of hedging strategies, stopping times and martingale
representations are presented for short (seller's) and long (buyer's) positions
in an American option with an arbitrary payoff. This general approach extends
the special cases considered in the literature concerned primarily with
computing the prices of American puts under transaction costs by relaxing any
restrictions on the form of the payoff, the magnitude of the transaction costs
or the discrete market model itself. The largely unexplored case of pricing,
hedging and stopping for the American option buyer under transaction costs is
also covered. The pricing algorithms are computationally efficient, growing
only polynomially with the number of time steps in a recombinant tree model.
The stopping times realising the ask (seller's) and bid (buyer's) option prices
can differ from one another. The former is generally a so-called mixed
(randomised) stopping time, whereas the latter is always a pure (ordinary)
stopping time.


title:
Comparison between classical potentials and ab initio for silicon under
  large shear

abstract:
  The homogeneous shear of the {111} planes along the <110> direction of bulk
silicon has been investigated using ab initio techniques, to better understand
the strain properties of both shuffle and glide set planes. Similar
calculations have been done with three empirical potentials, Stillinger-Weber,
Tersoff and EDIP, in order to find the one giving the best results under large
shear strains. The generalized stacking fault energies have also been
calculated with these potentials to complement this study. It turns out that
the Stillinger-Weber potential better reproduces the ab initio results, for the
smoothness and the amplitude of the energy variation as well as the
localization of shear in the shuffle set.


title:
Theoretical investigations of a highly mismatched interface: the case of
  SiC/Si(001)

abstract:
  Using first principles, classical potentials, and elasticity theory, we
investigated the structure of a semiconductor/semiconductor interface with a
high lattice mismatch, SiC/Si(001). Among several tested possible
configurations, a heterostructure with (i) a misfit dislocation network pinned
at the interface and (ii) reconstructed dislocation cores with a carbon
substoichiometry is found to be the most stable one. The importance of the slab
approximation in first-principles calculations is discussed and estimated by
combining classical potential techniques and elasticity theory. For the most
stable configuration, an estimate of the interface energy is given. Finally,
the electronic structure is investigated and discussed in relation with the
dislocation array structure. Interface states, localized in the heterostructure
gap and located on dislocation cores, are identified.


title: Combined Electric and Magnetic Aharonov-Bohm Effects

abstract:
  It is well-known that the electric and magnetic Aharonov-Bohm effects may be
formally described on equal footing using the four-vector potential in a
relativistic framework. We propose an illustrative manifestation of both
effects in a single configuration, in which the specific path of the charged
particle determines the weight of the electric and magnetic acquired relative
phases. The phases can be distinctively obtained in the Coulomb gauge. The
scheme manifests the pedagogical lesson that though each of the relative phases
is gauge-dependent their sum is gauge-invariant.


title:
Theoretical study of dislocation nucleation from simple surface defects
  in semiconductors

abstract:
  Large-scale atomistic calculations, using empirical potentials for modeling
semiconductors, have been performed on a stressed system with linear surface
defects like steps. Although the elastic limits of systems with surface defects
remain close to the theoretical strength, the results show that these defects
weaken the atomic structure, initializing plastic deformations, in particular
dislocations. The character of the dislocation nucleated can be predicted
considering both the resolved shear stress related to the applied stress
orientation and the Peierls stress. At low temperature, only glide events in
the shuffle set planes are observed. Then they progressively disappear and are
replaced by amorphization/melting zones at a temperature higher than 900 K.


title:
Temperature dependent sound velocity in hydrodynamic equations for
  relativistic heavy-ion collisions

abstract:
  We analyze the effects of different forms of the sound-velocity function
cs(T) on the hydrodynamic evolution of matter formed in the central region of
relativistic heavy-ion collisions. At high temperatures (above the critical
temperature Tc) the sound velocity is calculated from the recent lattice
simulations of QCD, while in the low temperature region it is obtained from the
hadron gas model. In the intermediate region we use different interpolations
characterized by the values of the sound velocity at the local maximum (at T =
0.4 Tc) and local minimum (at T = Tc). In all considered cases the temperature
dependent sound velocity functions yield the entropy density, which is
consistent with the lattice QCD simulations at high temperature. Our
calculations show that the presence of a distinct minimum of the sound velocity
leads to a very long (about 20 fm/c) evolution time of the system, which is not
compatible with the recent estimates based on the HBT interferometry. Hence, we
conclude that the hydrodynamic description is favored in the case where the
cross-over phase transition renders the smooth sound velocity function with a
possible shallow minimum at Tc.


title:
When will a One Parameter Family of Unimodal Maps Produce Finite Limit
  Cycles Monotonically with the Parameter?

abstract:
  In this note we consider a collection $\cal{C}$ of one parameter families of
unimodal maps of $[0,1].$ Each family in the collection has the form $\{\mu
f\}$ where $\mu\in [0,1].$ Denoting the kneading sequence of $\mu f$ by $K(\mu
f)$, we will prove that for each member of $\cal{C}$, the map $\mu\mapsto K(\mu
f)$ is monotone. It then follows that for each member of $\cal{C}$ the map
$\mu\mapsto h(\mu f)$ is monotone, where $h(\u{f})$ is the topological entropy
of $\mu f.$ For interest, $\mu f(x)=4\mu x(1-x)$ and $\mu f(x)=\mu\sin(\pi x)$
are shown to belong to $\cal{C}.$ This extends the work of Masato Tsujii [1].


title: The Effects of Partial Crop Harvest on Biological Pest Control

abstract:
  In this paper, the effects of periodic partial harvesting of a continuously
grown crop on augmentative biological control are analyzed. Partial harvesting
can remove a proportion of both pests and biological control agents, so its
influence on the control efficiency cannot be a priori neglected. An impulsive
model consisting of a general predator-prey model in ODE, augmented by a
discrete component to depict releases of biological control agents and the
periodic partial harvesting is used. The periods are taken as integer multiples
of each other. A stability condition for pest eradication is expressed as the
minimal value of the budget per unit time to spend on predators. We consider
the partial harvesting period to be fixed by both the plant's physiology and
market forces so that the only manipulated variable is the release period. It
is shown that varying the release period with respect to the harvest period
influences the minimal budget value when the former is carried out more often
than the latter and has no effect when releases take place as often as or less
frequently than the partial harvests.


title: Analytic continuation of residue currents

abstract:
  Let $X$ be a complex manifold and $f\colon X\to \C^p$ a holomorphic mapping
defining a complete intersection. We prove that the iterated Mellin transform
of the residue integral associated to $f$ has an analytic continuation to a
neighborhood of the origin in $\C^p$.


title: Linear convergence of iterative soft-thresholding

abstract:
  In this article a unified approach to iterative soft-thresholding algorithms
for the solution of linear operator equations in infinite dimensional Hilbert
spaces is presented. We formulate the algorithm in the framework of generalized
gradient methods and present a new convergence analysis. As main result we show
that the algorithm converges with linear rate as soon as the underlying
operator satisfies the so-called finite basis injectivity property or the
minimizer possesses a so-called strict sparsity pattern. Moreover it is shown
that the constants can be calculated explicitly in special cases (i.e. for
compact operators). Furthermore, the techniques also can be used to establish
linear convergence for related methods such as the iterative thresholding
algorithm for joint sparsity and the accelerated gradient projection method.


title:
Experimental Review on Lepton Universality and Lepton Flavour Violation
  tests at the B-factories

abstract:
  Since 1999, the B-factories collaborations BABAR and Belle have accumulated
and studied large samples of tau lepton pairs. The experimental results on
Lepton Universality checks and Lepton Flavour Violation searches are reported.


title:
Relevance of angular momentum conservation in mesoscale hydrodynamics
  simulations

abstract:
  The angular momentum is conserved in fluids with a few exceptions such as
ferrofluids. However it can be violated locally in fluid simulations to reduce
computational costs. The effects of this violation are investigated using a
particle-based simulation method, multi-particle collision dynamics, which can
switch on or off angular-momentum conservation. To this end, we study circular
Couette flows between concentric and eccentric cylinders, where non-physical
torques due to the lack of the angular-momentum conservation are found whereas
the velocity field is not affected. In addition, in simulations of fluids with
different viscosities in contact and star polymers in solvent, incorrect
angular velocities occur. These results quantitatively agree with the
theoretical predictions based on the macroscopic stress tensor.


title:
Temporal evolution of the Evershed flow in sunspots. II. Physical
  properties and nature of Evershed clouds

abstract:
  Context: Evershed clouds (ECs) represent the most conspicuous variation of
the Evershed flow in sunspot penumbrae. Aims: We determine the physical
properties of ECs from high spatial and temporal resolution spectropolarimetric
measurements. Methods: The Stokes profiles of four visible and three infrared
spectral lines are subject to inversions based on simple one-component models
as well as more sophisticated realizations of penumbral flux tubes embedded in
a static ambient field (uncombed models). Results: According to the
one-component inversions, the EC phenomenon can be understood as a perturbation
of the magnetic and dynamic configuration of the penumbral filaments along
which these structures move. The uncombed inversions, on the other hand,
suggest that ECs are the result of enhancements in the visibility of penumbral
flux tubes. We conjecture that the enhancements are caused by a perturbation of
the thermodynamic properties of the tubes, rather than by changes in the vector
magnetic field. The feasibility of this mechanism is investigated performing
numerical experiments of thick penumbral tubes in mechanical equilibrium with a
background field. Conclusions: While the one-component inversions confirm many
of the properties indicated by a simple line parameter analysis (Paper I of
this series), we tend to give more credit to the results of the uncombed
inversions because they take into account, at least in an approximate manner,
the fine structure of the penumbra.


title: Is Communication Complexity Physical?

abstract:
  Recently, Brassard et. al. conjectured that the fact that the maximal
possible correlations between two non-local parties are the quantum-mechanical
ones is linked to a reasonable restriction on communication complexity. We
provide further support for the conjecture in the multipartite case. We show
that any multipartite communication complexity problem could be reduced to
triviality, had Nature been more non-local than quantum-mechanics by a quite
small gap for any number of parties. Intriguingly, the multipartite
nonlocal-box that we use to show the result corresponds to the generalized Bell
inequality that manifests maximal violation in respect to a local
hidden-variable theory.


title: The Nonlinear Essence of Gravitational Waves

abstract:
  A critical review of gravitational wave theory is made. It is pointed out
that the usual linear approach to the gravitational wave theory is neither
conceptually consistent nor mathematically justified. Relying upon that
analysis it is then argued that -- analogously to a Yang-Mills propagating
field, which must be nonlinear to carry its gauge charge -- a gravitational
wave must necessarily be nonlinear to transport its own charge -- that is,
energy-momentum.


title:
First principles determination of the Peierls stress of the shuffle
  screw dislocation in silicon

abstract:
  The Peierls stress of the a/2<110> screw dislocation belonging to the shuffle
set is calculated for silicon using density functional theory. We have checked
the effect of boundary conditions by using two models, the supercell method
where one considers a periodic array of dislocations, and the cluster method
where a single dislocation is embedded in a small cluster. The Peierls stress
is underestimated with the supercell and overestimated with the cluster. These
contributions have been calculated and the Peierls stress is determined in the
range between 2.4 x 10-2 and 2.8 x 10-2 eV {\AA}-3. When moving, the
dislocation follows the {111} plane going through a low energy metastable
configuration and never follows the 100 plane, which includes a higher energy
metastable core configuration.


title:
Ab initio molecular dynamics calculations of threshold displacement
  energies in silicon carbide

abstract:
  Using first principles molecular dynamics simulations, we have determined the
threshold displacement energies and the associated created defects in cubic
silicon carbide. Contrary to previous studies using classical molecular
dynamics, we found values close to the experimental consensus, and also created
defects in good agreement with recent works on interstitials stability in
silicon carbide. We carefully investigated the limits of this approach. Our
work shows that it is possible to calculate displacement energies with first
principles accuracy in silicon carbide, and suggests that it may be also the
case for other covalent materials.


title: Local and global methods in arithmetic (in Russian)

abstract:
  Let $p$ be a prime. We discuss methods of solution of congruences modulo
$p^n$ using $p$-adic numbers; these methods are similar to computations with
real numbers (local methods). Examples of relations between local and global
methods are given producing a passage from congruences to solutions in integers
(global methods). The use of a computer is illistrated for the study of
$p$-adic numbers and algebraic curves.


title: The hyperbolic geometric flow on Riemann surfaces

abstract:
  In this paper the authors study the hyperbolic geometric flow on Riemann
surfaces. This new nonlinear geometric evolution equation was recently
introduced by the first two authors motivated by Einstein equation and
Hamilton's Ricci flow. We prove that, for any given initial metric on
${\mathbb{R}}^{2}$ in certain class of metrics, one can always choose suitable
initial velocity symmetric tensor such that the solution exists for all time,
and the scalar curvature corresponding to the solution metric $g_{ij}$ keeps
uniformly bounded for all time. If the initial velocity tensor does not satisfy
the condition, then the solution blows up at a finite time, and the scalar
curvature $R(t,x)$ goes to positive infinity as $(t,x)$ tends to the blowup
points, and a flow with surgery has to be considered. The authors attempt to
show that, comparing to Ricci flow, the hyperbolic geometric flow has the
following advantage: the surgery technique may be replaced by choosing suitable
initial velocity tensor. Some geometric properties of hyperbolic geometric flow
on general open and closed Riemann surfaces are also discussed.


title: First results on e^+e^- -> 3 jets at NNLO

abstract:
  Precision studies of QCD at $e^+e^-$ colliders are based on measurements of
event shapes and jet rates. To match the high experimental accuracy,
theoretical predictions to next-to-next-to-leading order (NNLO) in QCD are
needed for a reliable interpretation of the data. We report the first
calculation of NNLO corrections (${\cal O}(\alpha_s^3)$) to three-jet
production and related event shapes, and discuss their phenomenological impact.


title:
The surprising external upturn of the Blue Straggler radial distribution
  in M55

abstract:
  By combining high-resolution HST and wide-field ground based observations, in
ultraviolet and optical bands, we study the Blue Straggler Star (BSS)
population of the low density galactic globular cluster M55 (NGC 6809) over its
entire radial extent. The BSS projected radial distribution is found to be
bimodal, with a central peak, a broad minimum at intermediate radii, and an
upturn at large radii. Similar bimodal distributions have been found in other
globular clusters (M3, 47 Tucanae, NGC 6752, M5), but the external upturn in
M55 is the largest found to date. This might indicate a large fraction of
primordial binaries in the outer regions of M55, which seems somehow in
contrast with the relatively low (\sim 10%) binary fraction recently measured
in the core of this cluster.


title: On q-summation and confluence

abstract:
  This paper is divided in two parts. In the first part we consider irregular
singular analytic q-difference equations, with q\in ]0,1[, and we show how the
Borel sum of a divergent solution of a differential equation can be uniformly
approximated on a convenient sector by a meromorphic solution of such a
q-difference equation. In the second part, we work under the assumption q\in
]1,+\infty[. In this case, at least four different q-Borel sums of a divergent
solution of an irregular singular analytic q-difference equations are spread in
the literature: under convenient assumptions we clarify the relations among
them.


title: Modular forms and $p$-adic numbers (in Russian)

abstract:
  Let $p$ be a prime. We discuss $p$-adic properties of various arithmetical
functions related to the coefficients of modular form and generating functions.
Modular forms are considered as a tool of solving arithmetical problems.
Examples of congruences between modular forms modulo $p$ and modulo $p^n$ are
given, and the use of a computer for the study of modular forms is illistrated.