title:
Encounter-driven accretion in young stellar clusters - A connection to
  FUors?

abstract:
  Context: The brightness of FUors increases by several magnitudes within one
to several years. The currently favoured explanation for this brightness boost
is that of dramatically rising accretion from the disc material around a young
star. The mechanism leading to this accretion increase is a point of debate.
Aims: Choosing the Orion Nebula Cluster as representative we simulate accretion
bursts driven by encounters in dense stellar environments. We investigate
whether properties like rise and decay times, event frequency etc. speak for
encounters as a possible cause for FUor phenomena. Method: We combine cluster
simulations performed with the Nbody6++ code with particle simulations that
describe the effect of a fly-by on the disc around a young star to determine
the induced mass accretion. Results: The induced accretion rates, the overall
temporal accretion profile, decay time and possibly the binarity rate we obtain
for encounter-induced accretion agree very well with observations of FUors.
However, the rise-time of one year observed in some FUors is difficult to
achieve in our simulations unless the matter is stored somewhere close to the
star and then released after a certain mass limit is transgressed. The severest
argument against the FUors phenomenon being caused by encounters is that most
FUors are found in environments of low stellar density. We extend the
discussion to eccentric binaries and gravitationally unstable discs and find
that both models have similar problems in achieving the necessary rise-times.
Conclusions: We predict that in dense young clusters these outbursts should
predominantly happen close to the cluster center and with large mass ratios
between the involved stars.(abridged)


title: Goos-H\"{a}nchen and Imbert-Fedorov shifts of polarized vortex beams

abstract:
  We study, analytically and numerically, reflection and transmission of an
arbitrarily polarized vortex beam on an interface separating two dielectric
media and derive general expressions for linear and angular Goos-Hanchen and
Imbert-Fedorov shifts. We predict a novel vortex-induced Goos-Hanchen shift,
and also reveal direct connection between the spin-induced angular shifts and
the vortex-induced linear shifts.


title:
On accuracy of approximation of the spectral radius by the Gelfand
  formula

abstract:
  The famous Gelfand formula $\rho(A)= \limsup_{n\to\infty}\|A^{n}\|^{1/n}$ for
the spectral radius of a matrix is of great importance in various mathematical
constructions. Unfortunately, the range of applicability of this formula is
substantially restricted by a lack of estimates for the rate of convergence of
the quantities $\|A^{n}\|^{1/n}$ to $\rho(A)$. In the paper this deficiency is
made up to some extent. By using the Bochi inequalities we establish explicit
computable estimates for the rate of convergence of the quantities
$\|A^{n}\|^{1/n}$ to $\rho(A)$. The obtained estimates are then extended for
evaluation of the joint spectral radius of matrix sets.


title: Incompleteness of the Landauer Formula for Electronic Transport

abstract:
  We show that the Landauer multi-terminal formula for the conductance of a
nanoscale system is incomplete because it does not take into account many-body
effects which cannot be treated as contributions to the single-particle
transmission probabilities. We show that the physical origin of these effects
is related to the viscous nature of the electron liquid, and develop a
perturbative formalism, based on the time-dependent current-density-functional
theory, for calculating the corrections to the resistance in terms of the
``Kohn-Sham current distribution'' and the exchange-correlation kernel. The
difficulties that still remain in calculating the latter are critically
discussed.


title: Another derivation of the geometrical KPZ relations

abstract:
  We give a physicist's derivation of the geometrical (in the spirit of
Duplantier-Sheffield) KPZ relations, via heat kernel methods. It gives a
covariant way to define neighborhoods of fractals in 2d quantum gravity, and
shows that these relations are in the realm of conformal field theory.

categories: math-ph cond-mat.stat-mech hep-th math.MP


title: Quantum asymmetric cryptography with symmetric keys

abstract:
  Based on quantum encryption, we present a new idea for quantum public-key
cryptography (QPKC) and construct a whole theoretical framework of a QPKC
system. We show that the quantum-mechanical nature renders it feasible and
reasonable to use symmetric keys in such a scheme, which is quite different
from that in conventional public-key cryptography. The security of our scheme
is analyzed and some features are discussed. Furthermore, the state-estimation
attack to a prior QPKC scheme is demonstrated.


title:
The Schrodinger-Chetaev Equation in Bohmian Quantum Mechanics and
  Diffusion Mechanism for Alpha Decay, Cluster Radioactivity and Spontaneous
  Fission

abstract:
  In the framework of Bohmian quantum mechanics supplemented with the Chetaev
theorem on stable trajectories in dynamics in the presence of dissipative
forces we have shown the possibility of the classical (without tunneling)
universal description of radioactive decay of heavy nuclei, in which under
certain conditions so called noise-induced transition is generated or, in other
words, the stochastic channel of alpha decay, cluster radioactivity and
spontaneous fission conditioned by the Kramers diffusion mechanism. Based on
the ENSDF database we have found the parametrized solutions of the Kramers
equation of Langevin type by Alexandrov dynamic auto-regularization method
(FORTRAN program REGN-Dubna). These solutions describe with high-accuracy the
dependence of the half-life (decay probability) of heavy radioactive nuclei on
total kinetic energy of daughter decay products. The verification of inverse
problem solution in the framework of the universal Kramers description of the
alpha decay, cluster radioactivity and spontaneous fission, which was based on
the newest experimental data of alpha-decay of even-even super heavy nuclei
(Z=114, 116, 118) have shown the good coincidence of the experimental and
theoretical half-life depend upon of alpha-decay energy.


title:
A comparison of the notions of optimality in soft constraints and
  graphical games

abstract:
  The notion of optimality naturally arises in many areas of applied
mathematics and computer science concerned with decision making. Here we
consider this notion in the context of two formalisms used for different
purposes and in different research areas: graphical games and soft constraints.
We relate the notion of optimality used in the area of soft constraint
satisfaction problems (SCSPs) to that used in graphical games, showing that for
a large class of SCSPs that includes weighted constraints every optimal
solution corresponds to a Nash equilibrium that is also a Pareto efficient
joint strategy.


title:
Large-Time Behavior of Periodic Entropy Solutions to Anisotropic
  Degenerate Parabolic-Hyperbolic Equations

abstract:
  We are interested in the large-time behavior of periodic entropy solutions in
$L^\infty$ to anisotropic degenerate parabolic-hyperbolic equations of
second-order. Unlike the pure hyperbolic case, the nonlinear equation is no
longer self-similar invariant and the diffusion term in the equation
significantly affects the large-time behavior of solutions; thus the approach
developed earlier based on the self-similar scaling does not directly apply. In
this paper, we develop another approach for establishing the decay of periodic
solutions for anisotropic degenerate parabolic-hyperbolic equations. The proof
is based on the kinetic formulation of entropy solutions. It involves time
translations and a monotonicity-in-time property of entropy solutions, and
employs the advantages of the precise kinetic equation for the solutions in
order to recognize the role of nonlinearity-diffusivity of the equation.


title: Synchronization of Coupled Anizochronous Auto-Oscillating Systems

abstract:
  The particular properties of synchronization are discussed for coupled
auto-oscillating systems, which are characterized by non-quadratic law of
potential dependence on the coordinate. In particular, structure of the
parameter plane (frequency mismatch - coupling value) is considered for coupled
van der Pol - Duffing oscillators. The arrangement of synchronization tongues
and the particular properties of their internal structure in the parameter
space are revealed. The features of attractors in the phase space are
discussed.


title:
Pressure-Driven Metal-Insulator Transition in Hematite from Dynamical
  Mean-Field Theory

abstract:
  The Local Density Approximation combined with Dynamical Mean-Field Theory
(LDA+DMFT method) is applied to the study of the paramagnetic and magnetically
ordered phases of hematite Fe$_2$O$_3$ as a function of volume. As the volume
is decreased, a simultaneous 1st order insulator-metal and high-spin to
low-spin transition occurs close to the experimental value of the critical
volume. The high-spin insulating phase is destroyed by a progressive reduction
of the charge gap with increasing pressure, upon closing of which the high spin
phase becomes unstable. We conclude that the transition in Fe$_2$O$_3$ at
$\approx$50 GPa can be described as an electronically driven volume collapse.


title: Welfare Undominated Groves Mechanisms

abstract:
  A common objective in mechanism design is to choose the outcome (for example,
allocation of resources) that maximizes the sum of the agents' valuations,
without introducing incentives for agents to misreport their preferences. The
class of Groves mechanisms achieves this; however, these mechanisms require the
agents to make payments, thereby reducing the agents' total welfare.
  In this paper we introduce a measure for comparing two mechanisms with
respect to the final welfare they generate. This measure induces a partial
order on mechanisms and we study the question of finding minimal elements with
respect to this partial order. In particular, we say a non-deficit Groves
mechanism is welfare undominated if there exists no other non-deficit Groves
mechanism that always has a smaller or equal sum of payments. We focus on two
domains: (i) auctions with multiple identical units and unit-demand bidders,
and (ii) mechanisms for public project problems. In the first domain we
analytically characterize all welfare undominated Groves mechanisms that are
anonymous and have linear payment functions, by showing that the family of
optimal-in-expectation linear redistribution mechanisms, which were introduced
in [6] and include the Bailey-Cavallo mechanism [1,2], coincides with the
family of welfare undominated Groves mechanisms that are anonymous and linear
in the setting we study. In the second domain we show that the classic VCG
(Clarke) mechanism is welfare undominated for the class of public project
problems with equal participation costs, but is not undominated for a more
general class.


title: Coupling strength estimation for spin chains despite restricted access

abstract:
  Quantum control requires full knowledge of the system many-body Hamiltonian.
In many cases this information is not directly available due to restricted
access to the system. Here we show how to indirectly estimate all the coupling
strengths in a spin chain by measuring one spin at the end of the chain. We
also discuss the efficiency of this "quantum inverse problem" and give a
numerical example.


title: Tractors, Mass and Weyl Invariance

abstract:
  Deser and Nepomechie established a relationship between masslessness and
rigid conformal invariance by coupling to a background metric and demanding
local Weyl invariance, a method which applies neither to massive theories nor
theories which rely upon gauge invariances for masslessness. We extend this
method to describe massive and gauge invariant theories using Weyl invariance.
The key idea is to introduce a new scalar field which is constant when
evaluated at the scale corresponding to the metric of physical interest. This
technique relies on being able to efficiently construct Weyl invariant
theories. This is achieved using tractor calculus--a mathematical machinery
designed for the study of conformal geometry. From a physics standpoint, this
amounts to arranging fields in multiplets with respect to the conformal group
but with novel Weyl transformation laws. Our approach gives a mechanism for
generating masses from Weyl weights. Breitenlohner--Freedman stability bounds
for Anti de Sitter theories arise naturally as do direct derivations of the
novel Weyl invariant theories given by Deser and Nepomechie. In constant
curvature spaces, partially massless theories--which rely on the interplay
between mass and gauge invariance--are also generated by our method. Another
simple consequence is conformal invariance of the maximal depth partially
massless theories. Detailed examples for spins s<=2 are given including tractor
and component actions, on-shell and off-shell approaches and gauge invariances.
For all spins s>=2 we give tractor equations of motion unifying massive,
massless, and partially massless theories.


title:
Higher dimensional bright solitons and their collisions in
  multicomponent long wave-short wave system

abstract:
  Bright plane soliton solutions of an integrable (2+1) dimensional
($n+1$)-wave system are obtained by applying Hirota's bilinearization method.
First, the soliton solutions of a 3-wave system consisting of two short wave
components and one long wave component are found and then the results are
generalized to the corresponding integrable ($n+1$)-wave system with $n$ short
waves and single long wave. It is shown that the solitons in the short wave
components (say $S^{(1)}$ and $S^{(2)}$) can be amplified by merely reducing
the pulse width of the long wave component (say L). The study on the collision
dynamics reveals the interesting behaviour that the solitons which split up in
the short wave components undergo shape changing collisions with intensity
redistribution and amplitude-dependent phase shifts. Even though similar type
of collision is possible in (1+1) dimensional multicomponent integrable
systems, to our knowledge for the first time we report this kind of collisions
in (2+1) dimensions. However, solitons which appear in the long wave component
exhibit only elastic collision though they undergo amplitude-dependent phase
shifts.


title: Integration and commissioning of the ATLAS Muon spectrometer

abstract:
  The ATLAS experiment at the Large Hadron Collider (LHC) at CERN is currently
waiting to record the first collision data in spring 2009. Its muon
spectrometer is designed to achieve a momentum resolution of 10% pT(mu) = 1
TeV/c. The spectrometer consists of a system of three superconducting air-core
toroid magnets and is instrumented with three layers of Monitored Drift Tube
chambers (Cathode Strip Chambers in the extreme forward region) as precision
detectors. Resistive Plate Chambers in the barrel and Thin Gap Chambers in the
endcap regions provide a fast trigger system.
  The spectrometer passed important milestones in the last year. The most
notable milestone was the installation of the inner layer of endcap muon
chambers, which constituted the last big piece of the ATLAS detector to be
lowered in the ATLAS cavern. In addition, during the last two years most of the
muon detectors were commissioned with cosmic rays while being assembled in the
underground experimental cavern. We will report on our experience with the
precision and trigger chambers, the optical spectrometer alignment system, the
level-1 trigger, and the ATLAS data acquisition system. Results of the global
performance of the muon system from data with magnetic field will also be
presented.


title: Interaction of reed and acoustic resonator in clarinetlike systems

abstract:
  Sound emergence in clarinetlike instruments is investigated in terms of
instability of the static regime. Various models of reed-bore coupling are
considered, from the pioneering work of Wilson and Beavers ["Operating modes of
the clarinet", J. Acoust. Soc. Am. 56, 653--658 (1974)] to more recent modeling
including viscothermal bore losses and vena contracta at the reed inlet. The
pressure threshold above which these models may oscillate as well as the
frequency of oscillation at threshold are calculated. In addition to Wilson and
Beavers' previous conclusions concerning the role of the reed damping in the
selection of the register the instrument will play on, the influence of the
reed motion induced flow is also emphasized, particularly its effect on playing
frequencies, contributing to reduce discrepancies between Wilson and Beavers'
experimental results and theory, despite discrepancies still remain concerning
the pressure threshold. Finally, analytical approximations of the oscillating
solution based on Fourier series expansion are obtained in the vicinity of the
threshold of oscillation. This allows to emphasize the conditions which
determine the nature of the bifurcation (direct or inverse) through which the
note may emerge, with therefore important consequences on the musical playing
performances.


title: Measurements and Mathematical Formalism of Quantum Mechanics

abstract:
  A scheme for constructing quantum mechanics is given that does not have
Hilbert space and linear operators as its basic elements. Instead, a version of
algebraic approach is considered. Elements of a noncommutative algebra
(observables) and functionals on this algebra (elementary states) associated
with results of single measurements are used as primary components of the
scheme. On the one hand, it is possible to use within the scheme the formalism
of the standard (Kolmogorov) probability theory, and, on the other hand, it is
possible to reproduce the mathematical formalism of standard quantum mechanics,
and to study the limits of its applicability. A short outline is given of the
necessary material from the theory of algebras and probability theory. It is
described how the mathematical scheme of the paper agrees with the theory of
quantum measurements, and avoids quantum paradoxes.


title: Natural Image Coding in V1: How Much Use is Orientation Selectivity?

abstract:
  Orientation selectivity is the most striking feature of simple cell coding in
V1 which has been shown to emerge from the reduction of higher-order
correlations in natural images in a large variety of statistical image models.
The most parsimonious one among these models is linear Independent Component
Analysis (ICA), whereas second-order decorrelation transformations such as
Principal Component Analysis (PCA) do not yield oriented filters. Because of
this finding it has been suggested that the emergence of orientation
selectivity may be explained by higher-order redundancy reduction. In order to
assess the tenability of this hypothesis, it is an important empirical question
how much more redundancies can be removed with ICA in comparison to PCA, or
other second-order decorrelation methods. This question has not yet been
settled, as over the last ten years contradicting results have been reported
ranging from less than five to more than hundred percent extra gain for ICA.
Here, we aim at resolving this conflict by presenting a very careful and
comprehensive analysis using three evaluation criteria related to redundancy
reduction: In addition to the multi-information and the average log-loss we
compute, for the first time, complete rate-distortion curves for ICA in
comparison with PCA. Without exception, we find that the advantage of the ICA
filters is surprisingly small. Furthermore, we show that a simple spherically
symmetric distribution with only two parameters can fit the data even better
than the probabilistic model underlying ICA. Since spherically symmetric models
are agnostic with respect to the specific filter shapes, we conlude that
orientation selectivity is unlikely to play a critical role for redundancy
reduction.


title:
Scaling and chiral extrapolation of pion mass and decay constant with
  maximally twisted mass QCD

abstract:
  We present an update of the results for pion mass and pion decay constant as
obtained by the ETM collaboration in large scale simulations with maximally
twisted mass fermions and two mass degenerate flavours of light quarks. We
discuss the continuum, chiral and infinite volume extrapolation of these
quantities as well as the extraction of low energy constants, and investigate
possible systematic uncertainties.


title:
A Reconsideration of the b -> s gamma Decay in the Minimal Flavor
  Violating MSSM

abstract:
  We present a MSSM study of the b -> s gamma decay in a Minimal Flavor
Violating (MFV) framework, where the form of the soft SUSY breaking terms is
determined by the Standard Model Yukawa couplings. In particular, we address
the role of gluino contributions, which are set to zero in most studies of the
MFV MSSM.
  Gluino contributions can play an important role in the MFV MSSM whenever mu *
tan(beta) is large. In fact, similarly to chargino contributions, gluino
contributions are tan(beta) enhanced and can easily dominate charged Higgs
contributions for large values of tan(beta). Even though each of the separate
contributions to b -> s gamma can be sizeable by itself, surprisingly no
absolute lower bound can be placed on any of the relevant SUSY masses, since
patterns of partial cancellations among the three competing contributions
(Higgs, chargino and gluino) can occur throughout the MSSM parameter space.


title: Charm spectroscopy beyond the constituent quark model

abstract:
  We study the nature of the new charm and charmonium like states observed in
the last few years, using a constituent quark model with an screened
confinement potential. In the open charm sector we discuss different options
for the $D_{sJ}(2860)$ including tetraquark configurations. In the hidden charm
sector the new Y(4360) and Y(4660) are interpreted as $1^{--}$ states. The
influence in the puzzling 3940 MeV region of multiquark configuration is
discussed.


title: Six bijections between deco polyominoes and permutations

abstract:
  In this paper we establish six bijections between a particular class of
polyominoes, called deco polyominoes, enumerated according to their directed
height by n!, and permutations. Each of these bijections allows us to establish
different correspondences between classical statistics on deco polyominoes and
on permutations.


title:
Sheaves and geometric logic and applications to the modular verification
  of complex systems

abstract:
  In this paper we show that states, transitions and behavior of concurrent
systems can often be modeled as sheaves over a suitable topological space. In
this context, geometric logic can be used to describe which local properties
(i.e. properties of individual systems) are preserved, at a global level, when
interconnecting the systems. The main area of application is to modular
verification of complex systems. We illustrate the ideas by means of an example
involving a family of interacting controllers for trains on a rail track.


title: Initial study on the shape optimisation of the CLIC crab cavity

abstract:
  The compact linear collider (CLIC) requires a crab cavity to align bunches
prior to collision. The bunch structure demands tight amplitude and phase
tolerances of the RF fields inside the cavity, for the minimal luminosity loss.
Beam loading effects require special attention as it is one potential sources
of field errors in the cavity. In order to assist the amplitude and phase
control, we propose a travelling wave (TW) structure with a high group velocity
allowing rapid propagation of errors out of the system. Such a design makes the
cavity structure significantly different from previous ones. This paper will
look at the implications of this on other cavity parameters and the
optimisation of the cavity geometry.


abstract:
  Ground-state electric quadrupole moment of 31Al (I =5/2+, T_1/2 = 644(25) ms)
has been measured by means of the beta-NMR spectroscopy using a spin-polarized
31Al beam produced in the projectile fragmentation reaction. The obtained Q
moment, |Q_exp(31Al)| = 112(32)emb, are in agreement with conventional shell
model calculations within the sd valence space. Previous result on the magnetic
moment also supports the validity of the sd model in this isotope, and thus it
is concluded that 31Al is located outside of the island of inversion.


title: Crab cavities for linear colliders

abstract:
  Crab cavities have been proposed for a wide number of accelerators and
interest in crab cavities has recently increased after the successful operation
of a pair of crab cavities in KEK-B. In particular crab cavities are required
for both the ILC and CLIC linear colliders for bunch alignment. Consideration
of bunch structure and size constraints favour a 3.9 GHz superconducting,
multi-cell cavity as the solution for ILC, whilst bunch structure and
beam-loading considerations suggest an X-band copper travelling wave structure
for CLIC. These two cavity solutions are very different in design but share
complex design issues. Phase stabilisation, beam loading, wakefields and mode
damping are fundamental issues for these crab cavities. Requirements and
potential design solutions will be discussed for both colliders.


title:
A remark on the integrals of motion associated with level $k$
  realization of the elliptic algebra $U_{q,p}(sl_2^)$

abstract:
  We give one parameter deformation of level $k$ free field realization of the
screening current of the elliptic algebra $U_{q,p}(sl_2^)$. By means of these
free field realizations, we construct infinitly many commutative operators,
which we call the nonlocal integrals of motion associated with level $k$
realization of the elliptic algebra $U_{q,p}(sl_2^)$. They are given as
integrals involving a product of the screening current and elliptic theta
functions. This paper give level $k$ generalization of the nonlocal integrals
of motion given in [arXiv:0705.0427].


title:
Bell-inequality test of spatial mode entanglement of a single massive
  particle

abstract:
  Experiments showing the violation of Bell inequalities have formed our belief
that the world at its smallest is genuinely non-local. While many non-locality
experiments use the first quantised picture, the physics of fields of
indistinguishable particles, such as bosonic gases, is captured most
conveniently by second quantisation. This implies the possibility of non-local
correlations, such as entanglement, between modes of the field. In this paper
we propose an experimental scheme that tests the theoretically predicted
entanglement between modes in space occupied by massive bosons. Moreover, the
implementation of the proposed scheme is capable of proving that the particle
number superselection rule is not a fundamental necessity of quantum theory but
a consequence of not possessing a distinguished reference frame.


title: On the exhaustive generation of convex permutominoes

abstract:
  A permutomino of size n is a polyomino determined by a pair of permutations
of size n+1, such that they differ in each position. In this paper, after
recalling some enumerative results about permutominoes, we give a first
algorithm for the exhaustive generation of a particular class of permutominoes,
the convex permutominoes, proving that its cost is proportional to the number
of generated objects.


title:
Deconfinement phase transition in N=4 super Yang-Mills theory on RxS^3
  from supersymmetric matrix quantum mechanics

abstract:
  We test the recent claim that supersymmetric matrix quantum mechanics with
mass deformation preserving maximal supersymmetry can be used to study N=4
super Yang-Mills theory on RxS^3 in the planar limit. When the mass parameter
is large, we can integrate out all the massive fluctuations around a particular
classical solution, which corresponds to RxS^3. The resulting effective theory
for the gauge field moduli at finite temperature is studied both analytically
and numerically, and shown to reproduce the deconfinement phase transition in
N=4 super Yang-Mills theory on RxS^3 at weak coupling. This transition was
speculated to be a continuation of the conjectured phase transition at strong
coupling, which corresponds to the Hawking-Page transition based on the
gauge-gravity duality. By choosing a different classical solution of the same
model, one can also reproduce results for gauge theories on other space-time
such as RxS^3/Z_q and RxS^2. All these theories can be studied at strong
coupling by the new simulation method, which was used successfully for
supersymmetric matrix quantum mechanics without mass deformation.


title:
Discovery of a very highly extinguished supernova in a luminous infrared
  galaxy

abstract:
  We report the discovery of a confirmed supernova (SN) and a
supernova-candidate in near-infrared images from the ALTAIR/NIRI adaptive
optics system on the Gemini-North Telescope and NICMOS on the Hubble Space
Telescope. The Gemini images were obtained as part of a near-infrared K-band
search for highly-obscured SNe in the nuclear regions of luminous infrared
galaxies. SN 2008cs apparent in the Gemini images is the first SN discovered
using laser guide star adaptive optics. It is located at 1500 pc projected
distance from the nucleus of the luminous infrared galaxy IRAS 17138-1017. The
SN luminosity, JHK colors and light curve are consistent with a core-collapse
event suffering from a very high host galaxy extinction of 15.7 +- 0.8
magnitudes in V-band which is to our knowledge the highest yet measured for a
SN. The core-collapse nature of SN 2008cs is confirmed by its radio detection
at 22.4 GHz using our Very Large Array observations 28 days after the SN
discovery, indicating a prominent interaction of the SN ejecta with the
circumstellar medium. An unconfirmed SN apparent in the NICMOS images from 2004
is located in the same galaxy at 660 pc projected distance from the nucleus and
has a lower extinction.


title: Uniqueness of Schrodinger flow via energy inequality

abstract:
  In this short note, we show a uniqueness result of the energy solutions for
the Cauchy problem of Schrodinger flow in the whole space $R^n$ provided there
is a smooth solution in the energy class.


title: 2PI simulations in expanding backgrounds: Doing it anyway!

abstract:
  I set out the 2PI formalism for quantum fields in a
Friedmann-Robertson-Walker Universe. I show how one can solve self-consistently
for the quantum field evolution and the evolution of the cosmological scale
factor, using a renormalised semi-classical Friedmann equation. In a 2PI
coupling expansion truncated at O(lambda^2), I perform sample calculations
demonstrating kinetic and chemical equilibration in this context.


title: CKM-UT Angles: Mixing and CP violation at the $B$ Factories

abstract:
  We review the experimental status of the angles of the Unitarity Triangle of
the CKM matrix, as measured by the BABAR and Belle experiments.


title: Mesoscopic model for colloidal particles, powders and granular solids

abstract:
  A simulation model is presented, comprising elastic spheres with a short
range attraction. Besides conservative forces, radial- and shear friction, and
radial noise are added. The model can be used to simulate colloids, granular
solids and powders, and the parameters may be related to experimental systems
via the range of attraction and the adhesion energy. The model shares the
simplicity and speed of Dissipative Particle Dynamics (DPD), yet the
predictions are rather non-trivial. We demonstrate that the model predicts the
correct scaling relations for fracture of granular solids, and we present a
schematic phase diagram. This shows liquid-vapor coexistence for sufficiently
large interaction range, with a surface tension that follows Ising criticality.
For smaller interaction range only solid-vapor coexistence is found, but for
very small attractive interaction range stable liquid-vapor coexistence
reappears due to pathological stability of the solid phase. At very low
temperature the model forms a glassy state.


title: Stein's method and stochastic analysis of Rademacher functionals

abstract:
  We compute explicit bounds in the Gaussian approximation of functionals of
infinite Rademacher sequences. Our tools involve Stein's method, as well as the
use of appropriate discrete Malliavin operators. Although our approach does not
require the classical use of exchangeable pairs, we employ a chaos expansion in
order to construct an explicit exchangeable pair vector for any random variable
which depends on a finite set of Rademacher variables. Among several examples,
which include random variables which depend on infinitely many Rademacher
variables, we provide three main applications: (i) to CLTs for multilinear
forms belonging to a fixed chaos, (ii) to the Gaussian approximation of
weighted infinite 2-runs, and (iii) to the computation of explicit bounds in
CLTs for multiple integrals over sparse sets. This last application provides an
alternate proof (and several refinements) of a recent result by Blei and
Janson.


title: Taming Modal Impredicativity: Superlazy Reduction

abstract:
  Pure, or type-free, Linear Logic proof nets are Turing complete once
cut-elimination is considered as computation. We introduce modal
impredicativity as a new form of impredicativity causing the complexity of
cut-elimination to be problematic from a complexity point of view. Modal
impredicativity occurs when, during reduction, the conclusion of a residual of
a box b interacts with a node that belongs to the proof net inside another
residual of b. Technically speaking, superlazy reduction is a new notion of
reduction that allows to control modal impredicativity. More specifically,
superlazy reduction replicates a box only when all its copies are opened. This
makes the overall cost of reducing a proof net finite and predictable.
Specifically, superlazy reduction applied to any pure proof nets takes
primitive recursive time. Moreover, any primitive recursive function can be
computed by a pure proof net via superlazy reduction.


title:
Spin-dependent electron-impurity scattering in two-dimensional electron
  systems

abstract:
  We present a theoretical study of elastic spin-dependent electron scattering
caused by a charged impurity in the vicinity of a two-dimensional electron gas.
We find that the symmetry properties of the spin-dependent differential
scattering cross section are different for an impurity located in the plane of
the electron gas and for one at a finite distance from the plane. We show that
in the latter case asymmetric (`skew') scattering can arise if the polarization
of the incident electron has a finite projection on the plane spanned by the
normal vector of the two-dimensional electron gas and the initial propagation
direction. In specially preparated samples this scattering mechanism may give
rise to a Hall-like effect in the presence of an in-plane magnetic field.


title:
Gamma-ray burst afterglows : luminosity clustering at infrared
  wavelengths?

abstract:
  Clustering in the luminosity of the afterglows of gamma-ray burst has been
reported in the optical and X-ray. We investigate the possibility that a
clustering in the luminosity of the afterglows of gamma-ray burst exists in
near infrared (J, H, K bands). We use observations of events occurring from
1997 to the end of 2007. We correct the gamma-ray burst afterglow light curve
for distance effect and time dilation, and replace all light curves to a common
distance of z=1. We used only observations of signal emitted in the near
infrared (in the burst frame). We observe a clustering identical to the one
observed in optical and similar to the one observed in X-ray. We thus confirm
the previous works made in optical. We set a constraint on the total energy of
the fireball.


title: Projection-operator formalism and coarse-graining

abstract:
  A careful derivation of the generalized Langevin equation using "Zwanzig
flavor" projection operator formalism is presented. We provide arguments why
this formalism has better properties compared to alternative
projection-operator formalisms for deriving non-equilibrium,
non-thermodynamic-limit, equations. The two main ingredients in the derivation
are Liouville's theorem and optimal prediction theory.
  As a result we find that equations for non-equilibrium thermodynamics are
dictated by the formalism once the choice of coarse-grained variables is made.
This includes a microcanonical entropy definition dependent on the
coarse-grained variables. Based on this framework we provide a methodology for
succesive coarse-graining. As two special cases, the case of linear
coefficients and coarse-graining in the thermodynamic limit are treated in
detail. In the linear limit the formulas found are equivalent with those of
homogenization theory.
  In this framework there are no restrictions with respect to the
thermodynamic-limit or nearness to equilibrium. We believe the presented
approach is very suitable for the development of computational methods by means
of coarse-graining from a more detailed level of description.


title: At infinity of finite-dimensional CAT(0) spaces

abstract:
  We show that any filtering family of closed convex subsets of a
finite-dimensional CAT(0) space $X$ has a non-empty intersection in the visual
bordification $ \bar{X} = X \cup \partial X$. Using this fact, several results
known for proper CAT(0) spaces may be extended to finite-dimensional spaces,
including the existence of canonical fixed points at infinity for parabolic
isometries, algebraic and geometric restrictions on amenable group actions, and
geometric superrigidity for non-elementary actions of irreducible uniform
lattices in products of locally compact groups.


title: Model of interacting dark energy in five-dimensional brane cosmology

abstract:
  We here investigate the model of interacting dark energy in the context of
five dimensional brane cosmology. The effective equations of state of dark
energy are evaluated for various choices of the variable time dependent
cosmological constant. We have found that the interacting dark energy obeys the
phantom divide/crossing scenario in this generalized model. It is also shown
that interacting dark energy in this generalized model also resolves the cosmic
coincidence problem.


title:
Dust Extinction in High-z Galaxies with GRB Afterglow Spectroscopy - The
  2175{\AA} Feature at z=2.45

abstract:
  We report the clear detection of the 2175A dust absorption feature in the
optical afterglow spectrum of the gamma-ray burst (GRB) GRB070802 at a redshift
of z=2.45. This is the highest redshift for a detected 2175A dust bump to date,
and it is the first clear detection of the 2175A bump in a GRB host galaxy,
while several tens of optical afterglow spectra without the bump have been
recorded in the past decade. The derived extinction curve gives A_V=0.8-1.5
depending on the assumed intrinsic slope. Of the three local extinction laws,
an LMC type extinction gives the best fit to the extinction curve of the host
of GRB070802. Besides the 2175A bump we find that the spectrum of GRB070802 is
characterized by unusually strong low-ionization metal lines and possibly a
high metallicity for a GRB sightline ([Si/H]=-0.46+/-0.38,
[Zn/H]=-0.50+/-0.68). In particular, the spectrum of GRB070802 is unique for a
GRB spectrum in that it shows clear CI absorption features, leading us to
propose a correlation between the presence of the bump and CI. The gas to dust
ratio for the host galaxy is found to be significantly lower than that of other
GRB hosts with N(HI)/A_V=(2.4+/-1.0)x10^21 cm^-2 mag^-1, which lies between
typical MW and LMC values. Our results are in agreement with the tentative
conclusion reached by Gordon et al. 2003 that the shape of the extinction
curve, in particular the presence of the bump, is affected by the UV flux
density in the environment of the dust.


title:
Hyperfine Level Splitting for Hydrogen-Like Ions due to Rotation-Spin
  Coupling

abstract:
  The theoretical aspects of spin-rotation coupling are presented. The approach
is based on the general covariance principle. It is shown that the
gyrogravitational ratio of the bare spin-1/2 and the spin-1 particles is equal
unity. That is why spin couples with rotation as an ordinary angular momentum.
This result is the rigorous substantiation of the cranking model. To observe
the phenomenon, the experiment with hydrogen-like ions in a storage ring is
suggested. It is found that the splitting of the $1 ^2!S_{1/2}, F=1/2$
hyperfine state of the $^{140}{\rm Pr}^{58+}$ and $^{142}{\rm Pm}^{60+}$ ions
circulating in the storage ring ESR in Darmstadt along a helical trajectory is
about 4.5 MHz. We argue that such splitting can be experimentally determined by
means of the ionic interferometry.


title:
HHSMT Observations of the Venusian Mesospheric Temperature, Winds, and
  CO abundance around the MESSENGER Flyby

abstract:
  We present submillimeter observations of 12CO J=3-2 and J=2-1, and 13CO J =
2-1 lines of the Venusian mesosphere and lower thermosphere with the Heinrich
Hertz Submillimeter Telescope (HHSMT) taken around the second MESSENGER flyby
of Venus on 5 June 2007. The observations cover a range of Venus solar
elongations with different fractional disk illuminations. Preliminary results
like temperature and CO abundance profiles are presented.These data are part of
a coordinated observational campaign in support of the ESA Venus Express
mission. Furthermore, this study attempts to contribute to cross-calibrate
space- and ground-based observations, to constrain radiative transfer and
retrieval algorithms for planetary atmospheres, and to a more thorough
understanding of the global patters of circulation of the Venusian atmosphere.


title:
Density matrix renormalization group study of a quantum impurity model
  with Landau-Zener time-dependent Hamiltonian

abstract:
  We use the adaptive time-dependent density matrix renormalization group
method (t-DMRG) to study the nonequilibrium dynamics of a benchmark quantum
impurity system which has a time-dependent Hamiltonian. This model is a
resonant-level model, obtained by a mapping from a certain Ohmic spin-boson
model describing the dissipative Landau-Zener transition. We map the
resonant-level model onto a Wilson chain, then calculate the time-dependent
occupation $n_d(t)$ of the resonant level. We compare t-DMRG results with exact
results at zero temperature and find very good agreement. We also give a
physical interpretation of the numerical results.


title: Correlations and Synchrony in Threshold Neuron Models

abstract:
  We study how threshold model neurons transfer temporal and interneuronal
input correlations to correlations of spikes. We find that the low common input
regime is governed by firing rate dependent spike correlations which are
sensitive to the detailed structure of input correlation functions. In the high
common input regime the spike correlations are insensitive to the firing rate
and exhibit a universal peak shape independent of input correlations. Rate
heterogeneous pairs driven by common inputs in general exhibit asymmetric spike
correlations. All predictions are confirmed in in vitro experiments with
cortical neurons driven by synthesized fluctuating input currents.


title: Forward Physics at the LHC; Elastic Scattering

abstract:
  The following effects in the nearly forward ("soft") region of the LHC are
proposed to be investigated: 1) At small |t| the fine structure of the cone
(Pomeron) shouldbe scrutinized: a) a break of the cone near $t\approx - 0.1 ~
GeV$^2, due to the two-pion threshold, and required by t-channel unitarity, is
expected, and b) possible small-period oscillations between $t=0$ and the dip
region. 2) In measuring the elastic $pp$ scattering and total $pp$ cross
section at the LHC, the experimentalists are urged to treat the total cross
section $\sigma_t,$ the ratio $\rho$, the forward slope $B$ and the luminosity
${\cal L}$ as free arameters, and to publish model-independent results on
${dN/{dt}}.$ 3) Of extreme interest are the details of the expected diffraction
minimum in the differential cross section. Its position, expected in the
interval $0.4<-t<1$ GeV$^2$ at the level of about $10^{-2} {\rm mb} \cdot$
GeV$^{-2}\div 10^{-1} {\rm mb}\cdot$ GeV$^{-2}$, cannot be predicted
unambiguously, and its depth, i.e. the ratio of $d\sigma/dt$ at the minimum to
that at the subsequent maximum (about $-t=5 $GeV$^2$, which is about 5 is of
great importance. 4) The expected slow-down with increasing $|t|$ of the
shrinkage of the second cone (beyond the dip-bump), together with the
transition from an exponential to a power decrease in $-t$, will be indicative
of the transition from "soft" to "hard" physics. Explicit models are proposed
to help in quantifying this transition. 5) In a number of papers a limiting
behavior, or saturation of the black disc limit (BDL) was predicted. This
controversial phenomenon shows that the BDL may not be the ultimate limit.


title: Ambient metrics for $n$-dimensional $pp$-waves

abstract:
  We provide an explicit formula for the Fefferman-Graham-ambient metric of an
$n$-dimensional conformal $pp$-wave in those cases where it exists. In even
dimensions we calculate the obstruction explicitly. Furthermore, we describe
all 4-dimensional $pp$-waves that are Bach-flat, and give a large class of
Bach-flat examples which are conformally Cotton-flat, but not conformally
Einstein. Finally, as an application, we use the obtained ambient metric to
show that even-dimensional $pp$-waves have vanishing critical $Q$-curvature.


title:
Impact parameter method calculations for fully differential ionization
  cross sections

abstract:
  In this work our previous fully differential ionization cross section
calculations using the semiclassical, impact parameter method are improved by a
new method suitable to calculate impact parameter values corresponding to
different momentum transfers. This goal is achieved by two successive steps.
First, using the transverse momentum balance different projectile scattering
angles are calculated for the binary and recoil peak regions as a function of
the transferred momentum. Then, by treating the projectile scattering as a
classical potential scattering problem, impact parameters are assigned to these
scattering angles. The new method, which no longer contains empirical
considerations, is tested calculating by fully differential ionization cross
sections for single ionization of helium produced by fast C$^{6+}$ ions.


title: Light and heavy baryon masses: the 1/N_c expansion and the quark model

abstract:
  We establish a connection between the quark model and the 1/N_c expansion
mass formulas used in the description of baryon resonances. We show that a
remarkable compatibility exists between the two methods in the light and heavy
baryon sectors. In particular, the band number used to classify baryons in the
1/N_c expansion is explained by the quark model and the mass formulas for both
approaches are consistent.


title: Screening of light mesons and charmonia at high temperature

abstract:
  We present lattice QCD results for the screening masses of light mesons and
charmonia. The lattice computations were performed with 2+1 flavors of improved
staggered quarks using quark masses which correspond to realistic pion and kaon
masses at zero temperature. For the light quark sector we have found that the
screening masses in the pseudo-scalar and the isovector scalar channels do not
become degenerate at the chiral crossover temperature indicating an effective
non-restoration of the axial symmetry. Also the splitting between the vector
and the pseudo-scalar screening masses persists even in the limit of zero
lattice spacing and at a moderately high temperature around 420 MeV. In the
charmonium sector our investigation shows that the screening masses of the
pseudo-scalar and the vector charmonia are almost (within a few percent) equal
to their zero temperature masses for temperatures less than 300 MeV. We also
present results for the charmonium screening masses using periodic boundary
conditions along the temporal direction and discuss their implications.


title: Dynamics of DNA translocation through an attractive nanopore

abstract:
  We investigate the dynamics of DNA translocation through a nanopore driven by
an external force using Langevin dynamics simulations in two dimensions (2D) to
study how the translocation dynamics depend on the details of the DNA
sequences. We consider a coarse-grained model of DNA built from two bases $A$
and $C$, having different base-pore interactions, {\textit e.g.}, a strong
(weak) attractive force between the pore and the base $A$ ($C$) inside the
pore. From a series of studies on hetero-DNAs with repeat units $A_mC_n$, we
find that the translocation time decreases exponentially as a function of the
volume fraction $f_C$ of the base $C$. %($\epsilon_{pC} < \epsilon_{pA}$). For
longer $A$ sequences with $f_C \le 0.5$, the translocation time strongly
depends on the orientation of DNA, namely which base enters the pore first. Our
studies clearly demonstrate that for a DNA of certain length $N$ with repeat
units $A_mC_n$, the pattern exhibited by the waiting times of the individual
bases and their periodicity can unambiguously determine the values of $m$, $n$
and $N$ respectively. Therefore, a prospective experimental realization of this
phenomenon may lead to fast and efficient sequence detection technic.


title: Magnetic ordering above room temperature in the sigma-phase of Fe66V34

abstract:
  Magnetic properties of four sigma-phase Fe_(100-x)V_x samples with
34.4<x<55.1 were investigated by Mossbauer spectroscopy and magnetic
measurements in the temperature interval 5-300 K. Four magnetic quantities viz.
hyperfine field, Curie temperature, magnetic moment and susceptibility were
determined. The sample containing 34.4 at% V was revealed to exhibit the
largest values found up to now for the sigma-phase for average hyperfine field,
B = 12.1 T, average magnetic moment per Fe atom, m = 0.89 mB, and Curie
temperature, TC = 315.5 K. The quantities were shown to be strongly correlated
with each other. In particular, TC is linearly correlated with m with a slope
of 406.5 K/mB, as well as B is so correlated with m yielding 14.3 T/mB for the
hyperfine coupling constant.


title: Commissioning of the ATLAS Pixel Detector

abstract:
  The ATLAS pixel detector is a high precision silicon tracking device located
closest to the LHC interaction point. It belongs to the first generation of its
kind in a hadron collider experiment. It will provide crucial pattern
recognition information and will largely determine the ability of ATLAS to
precisely track particle trajectories and find secondary vertices. It was the
last detector to be installed in ATLAS in June 2007, has been fully connected
and tested in-situ during spring and summer 2008. It is currently in a
commissioning phase using cosmic-ray events. We present the highlights of the
past and future commissioning activities of the ATLAS pixel system.


title:
The quest for the ideal photodetector for the next generation
  deep-underwater neutrino telescopes

abstract:
  We review photodetectors used in present running neutrino telescopes. After a
brief historical discourse, the photodetector requirements for the next
generation deep underwater neutrino telescopes are discussed. It is shown that
large area vacuum hybrid phototubes are the closest to the ideal photodetector
for such kind of applications when compared with other vacuum phototubes.


title: Topological quantum numbers and curvature -- examples and applications

abstract:
  Using the idea of the degree of a smooth mapping between two manifolds of the
same dimension we present here the topological (homotopical) classification of
the mappings between spheres of the same dimension, vector fields, monopole and
instanton solutions. Starting with a review of the elements of Riemannian
geometry we also present an original elementary proof of the Gauss-Bonnet
theorem and the Poincar\'{e}-Hopf theorem.


title:
Entanglement, Berry Phases, and Level Crossings for the Atomic
  Breit-Rabi Hamiltonian

abstract:
  The relation between level crossings, entanglement, and Berry phases is
investigated for the Breit-Rabi Hamiltonian of hydrogen and sodium atoms,
describing a hyperfine interaction of electron and nuclear spins in a magnetic
field. It is shown that the entanglement between nuclear and electron spins is
maximum at avoided crossings. An entangled state encircling avoided crossings
acquires a marginal Berry phase of a subsystem like an instantaneous eigenstate
moving around real crossings accumulates a Berry phase. Especially, the nodal
points of a marginal Berry phase correspond to the avoided crossing points.


title: Effective Hamiltonian Approach to Open Systems and Its Applications

abstract:
  By using the effective Hamiltonian approach, we present a self-consistent
framework for the analysis of geometric phases and dynamically stable
decoherence-free subspaces in open systems. Comparisons to the earlier works
are made. This effective Hamiltonian approach is then extended to a
non-Markovian case with the generalized Lindblad master equation. Based on this
extended effective Hamiltonian approach, the non-Markovian master equation
describing a dissipative two-level system is solved, an adiabatic evolution is
defined and the corresponding adiabatic condition is given.


title: Vector Boson + Heavy Flavor Jets Production at the Tevatron

abstract:
  Recent measurements on the vector boson plus heavy-flavor jets production by
the CDF and D0 experiments are presented in comparisons with recent theoretical
predictions. Good understanding of such processes is important to improve our
understanding of QCD and also to enhance the potential to search for
yet-to-be-discovered new physics phenomena which lead to similar final states.


title: Localization and Superconductivity in Doped Semiconductors

abstract:
  Motivated by the discovery of superconductivity in boron-doped (B-doped)
diamond, we investigate the localization and superconductivity in heavily doped
semiconductors. The competition between Anderson localization and s-wave
superconductivity is investigated from the microscopic point of view. The
effect of microscopic inhomogeneity and the thermal fluctuation in
superconductivity are taken into account using the self-consistent 1-loop-order
theory with respect to superconducting fluctuation. The crossover from
superconductivity in the host band to that in the impurity band is described on
the basis of the disordered three-dimensional attractive Hubbard model for
binary alloys. We show that superconductor-insulator transition (SIT)
accompanies the crossover. We point out an enhancement of Cooper pairing in the
crossover regime. Further localization of the electron wave function gives rise
to incoherent Cooper pairs and the pseudogap above T_c. A global phase diagram
is drawn for host band superconductivity, impurity band superconductivity,
Anderson localization, Fermi liquid state, and pseudogap state. A theoretical
interpretation is proposed for superconductivity in the doped diamond, SiC, and
Si.


title: Tableaux Combinatorics for the Asymmetric Exclusion Process II

abstract:
  The results of this paper have been subsumed by those of our new paper
arXiv:0910.1858


title: On Sums of Indicator Functions in Dynamical Systems

abstract:
  In this paper, we are interested in the limit theorem question for sums of
indicator functions. We show that in every aperiodic dynamical system, for
every increasing sequence $(a_n)_{n\in\N}\subset\R_+$ such that
$a_n\nearrow\infty$ and $\frac{a_n}{n}\to 0$ as $n\to\infty$, there exists a
measurable set $A$ such that the sequence of the distributions of the partial
sums $\frac{1}{a_n}\sum_{i=0}^{n-1}(\ind_A-\mu(A))\circ T^i$ is dense in the
set of the probability measures on $\R$. Further, in the ergodic case, we prove
that there exists a dense $G_\delta$ of such sets.


title:
Spectroscopy of Superradiant scattering from an array of Bose-Einstein
  Condensates

abstract:
  We theoretically study the superradiant gain and the direction of this
coherent radiant for an array of Bose-Einstein condensates in an optical
lattice. We find that the density grating is formed to amplify the scattering
light within the phase match condition. The scattering spectroscopy in the
momentum space can provide a method for measuring the overlap of wavefunction
between the neighboring sites, which is related to their inner-site and
inter-site coherence.


title: Properties of weight posets for weight multiplicity free representations

abstract:
  We study weight posets of weight multiplicity free (=wmf) representations $R$
of reductive Lie algebras. Specifically, we are interested in relations between
$\dim R$ and the number of edges in the Hasse diagram of the corresponding
weight poset, $# E(R)$. We compute the number of edges and upper covering
polynomials for the weight posets of all wmf-representations. We also point out
non-trivial isomorphisms between weight posets of different irreducible
wmf-representations.
  Our main results concern wmf-representations associated with periodic
gradings or Z-gradings of simple Lie algebras. For Z-gradings, we prove that
$0< 2dim R-# E(R) < h$, where $h$ is the Coxeter number of $\mathfrak g$. For
periodic gradings, we prove that $0\le 2dim R-# E(R)$.


title:
Topologically protected qubits as minimal Josephson junction arrays with
  non trivial boundary conditions: a proposal

abstract:
  Recently a one-dimensional closed ladder of Josephson junctions has been
studied (G. Cristofano et al., Phys. Lett. A 372 (2008) 2464) within a twisted
conformal field theory (CFT) approach (G. Cristofano et al., Mod. Phys. Lett. A
15 (2000) 1679; Nucl. Phys. B 641 (2002) 547) and shown to develop the
phenomenon of flux fractionalization (G. Cristofano et al., Eur. Phys. J. B 49
(2006) 83). That led us to predict the emergence of a topological order in such
a system (G. Cristofano et al., JSTAT (2005) P03006). In this letter we analyze
the ground states and the topological properties of fully frustrated Josephson
junction arrays (JJA) arranged in a Corbino disk geometry for a variety of
boundary conditions. In particular minimal configurations of fully frustrated
JJA are considered and shown to exhibit the properties needed in order to build
up a solid state qubit, protected from decoherence. The stability and
transformation properties of the ground states of the JJA under adiabatic
magnetic flux changes are analyzed in detail in order to provide a tool for the
manipulation of the proposed qubit.


title: NNLO corrections to B --> X_u l nu and the determination of |V_ub|

abstract:
  The calculation of partial decay rates in B --> X_u l nu decays at
next-to-next-to-leading order (NNLO) in alpha_s and to leading order in 1/m_b
is described. New results for the hard function are combined with known results
for the jet function and shape-function moments in a numerical analysis which
explores the impact of the NNLO corrections on partial decay rates and the
determination of |V_{ub}|.


title:
Renormalization in theories with modified dispersion relations: weak
  gravitational fields

abstract:
  We consider a free quantum scalar field satisfying modified dispersion
relations in curved spacetimes, within the framework of Einstein-Aether theory.
Using a power counting analysis, we study the divergences in the adiabatic
expansion of <\phi^2> and <T_{\mu\nu}>, working in the weak field
approximation. We show that for dispersion relations containing up to $2s$
powers of the spatial momentum, the subtraction necessary to renormalize these
two quantities on general backgrounds depends on $s$ in a qualitatively
different way: while <\phi^2> becomes convergent for a sufficiently large value
of $s$, the number of divergent terms in the adiabatic expansion of
<T_{\mu\nu}> increases with $s$. This property was not apparent in previous
results for spatially homogeneous backgrounds.


title: Galactic and Extragalactic Magnetic Fields

abstract:
  The strength of the total magnetic field in our Milky Way from radio Zeeman
and synchrotron measurements is about 6 muG near the Sun and several mG in
dense clouds, pulsar wind nebulae, and filaments near the Galactic Center.
Diffuse polarized radio emission and Faraday rotation of the polarized emission
from pulsars and background sources show many small-scale magnetic features,
but the overall field structure in our Galaxy is still under debate. -- Radio
synchrotron observations of nearby galaxies reveal dynamically important
magnetic fields of 10-30 muG total strength in the spiral arms. Fields with
random orientations are concentrated in spiral arms, while ordered fields
(observed in radio polarization) are strongest in interarm regions and follow
the orientation of the adjacent gas spiral arms. Faraday rotation of the
diffuse polarized radio emission from the disks of spiral galaxies sometimes
reveals large-scale patterns which are signatures of coherent fields generated
by dynamos, but in most galaxies the field structure is more complicated. --
Strong magnetic fields are also observed in radio halos around edge-on
galaxies, out to large distances from the plane. The synchrotron scaleheight of
radio halos allows to measure the mean outflow velocity of the cosmic-ray
electrons. The ordered halo fields mostly form an X-shaped pattern, but no
large-scale pattern is seen in the Faraday rotation data. Diffuse polarized
radio emission in the outer disks and halos is an excellent tracer of galaxy
interactions and ram pressure by the intergalactic medium. -- Intracluster gas
can also be significantly magnetized and highly polarized due to shocks or
cluster mergers.


title:
BER and Outage Probability Approximations for LMMSE Detectors on
  Correlated MIMO Channels

abstract:
  This paper is devoted to the study of the performance of the Linear Minimum
Mean-Square Error receiver for (receive) correlated Multiple-Input
Multiple-Output systems. By the random matrix theory, it is well-known that the
Signal-to-Noise Ratio (SNR) at the output of this receiver behaves
asymptotically like a Gaussian random variable as the number of receive and
transmit antennas converge to +$\infty$ at the same rate. However, this
approximation being inaccurate for the estimation of some performance metrics
such as the Bit Error Rate and the outage probability, especially for small
system dimensions, Li et al. proposed convincingly to assume that the SNR
follows a generalized Gamma distribution which parameters are tuned by
computing the first three asymptotic moments of the SNR. In this article, this
technique is generalized to (receive) correlated channels, and closed-form
expressions for the first three asymptotic moments of the SNR are provided. To
obtain these results, a random matrix theory technique adapted to matrices with
Gaussian elements is used. This technique is believed to be simple, efficient,
and of broad interest in wireless communications. Simulations are provided, and
show that the proposed technique yields in general a good accuracy, even for
small system dimensions.


title: Non-K\"ahler Expanding Ricci Solitons

abstract:
  We produce new examples of non-K\"ahler complete expanding gradient Ricci
solitons on trivial vector bundles over a product of Einstein manifolds with
positive scalar curvature.


title:
Lie-Rinehart cohomology and integrable connections on modules of rank
  one

abstract:
  Let $k$ be an algebraically closed field of characteristic 0, let $R$ be a
commutative $k$-algebra, and let $M$ be a torsion free $R$-module of rank one
with a connection $\nabla$. We consider the Lie-Rinehart cohomology with values
in $End_{R}(M)$ with its induced connection, and give an interpretation of this
cohomology in terms of the integrable connections on $M$. When $R$ is an
isolated singularity of dimension $d\geq2$, we relate the Lie-Rinehart
cohomology to the topological cohomology of the link of the singularity, and
when $R$ is a quasi-homogenous hypersurface of dimension two, we give a
complete computation of the cohomology.


title: Quantum random walks and thermalisation

abstract:
  It is shown how to construct quantum random walks with particles in an
arbitrary faithful normal state. A convergence theorem is obtained for such
walks, which demonstrates a thermalisation effect: the limit cocycle obeys a
quantum stochastic differential equation without gauge terms. Examples are
presented which generalise that of Attal and Joye (2007, J. Funct. Anal. 247,
253-288).


title:
Early Discoveries of New Gauge Bosons W' and Z' in Leptonic Decay
  Channels at ATLAS

abstract:
  We present the potential of the ATLAS detector to discover new massive gauge
bosons in their leptonic decay channels: W' -> l nu_l and Z' -> l+ l-. Emphasis
is placed on early data-taking at the LHC with low luminosity (up to 1 fb^-1).


title:
Intermediate range chemical ordering of cations in simple molten alkali
  halides

abstract:
  The presence of first sharp diffraction peaks in the partial structure
factors is investigated in computer simulations of molten mixtures of alkali
halides. An intermediate range ordering appears for the Li+ ions only, which is
associated with clustering of this species and is not reflected in the
arrangement of other ions. This ordering is surprising in view of the
simplicity of the interionic interactions in alkali halides. The clustering
reflects an incomplete mixing of the various species on a local length scale,
which can be demonstrated by studying the complementary sub-space of cations in
the corresponding pure alkali halides by means of a void analysis.


title:
Explicit formulas for Laplace transforms of certain functionals of some
  time inhomogeneous diffusions

abstract:
  We consider a process $(X_t)_{t\in[0,T)}$ given by the SDE $dX_t = \alpha
b(t)X_t dt + \sigma(t) dB_t$, $t\in[0,T)$, with initial condition $X_0=0$,
where $T\in(0,\infty]$, $\alpha\in R$, $(B_t)_{t\in[0,T)}$ is a standard Wiener
process, $b:[0,T)\to R\setminus\{0\}$ and $\sigma:[0,T)\to(0,\infty)$ are
continuously differentiable functions. Assuming that $b$ and $\sigma$ satisfy a
certain differential equation we derive an explicit formula for the joint
Laplace transform of $\int_0^t\frac{b(s)^2}{\sigma(s)^2}(X_s)^2 ds$ and
$(X_t)^2$ for all $t\in[0,T)$. As an application, we study asymptotic behavior
of the maximum likelihood estimator of $\alpha$ for $\sign(\alpha-K)=\sign(K)$,
$K\ne0$, and for $\alpha=K$, $K\ne0$. As an example, we examine the so-called
$\alpha$-Wiener bridges given by SDE $dX_t = -\frac{\alpha}{T-t}X_t dt + dB_t$,
$t\in[0,T)$, with initial condition $X_0=0$.


title:
Evolution of very low mass pre-main sequence stars and young brown
  dwarfs under accretion: A phenomenological approach

abstract:
  In the poster presented in Cool Star 15, we analyzed the effect of disk
accretion on the evolution of very low mass pre-main sequence stars and young
brown dwarfs and the resulting uncertainties on the determination of masses and
ages. We use the Lyon evolutionary 1-D code assuming a magnetospheric accretion
process, i.e., the material falls covering a small area of the radiative
surface, and we take into account the internal energy added from the accreted
material as a free parameter $\epsilon$. Even if the approach to this problem
is phenomenological, our formalism provides important hints about
characteristics of disk accretion, which are useful for improved stellar
interior calculations. Using the accretion rates derived from observations our
results show that accretion does not affect considerably the position of
theoretical isochrones as well as the luminosity compared with standard
non-accreting models. See more discussions in a forthcoming paper by Gallardo,
Baraffe and Chabrier (2008).


title:
Prompt GeV Emission from Residual Collisions in GRB Outflows: Evidence
  from Fermi Observations of GRB 080916c

abstract:
  The gamma-rays from gamma-ray bursts (GRBs) are believed to be produced by
internal shocks driven by small timescale, ~1 ms, variation in the GRB
outflows, and a pair-production spectral cutoff is generally expected around
the GeV range. However, the observed optical flashes accompanying GRBs suggest
that the delayed residual collisions due to large timescale variation continue
to accelerate electrons. We show here that the inverse-Compton (IC) scattering
of the prompt gamma-rays by these residual internal shock electrons leads to a
high energy emission beyond the previously thought spectral cutoff, in
agreement with the previous detections of GeV photons by EGRET in several GRBs
in conjunction with MeV emission. We expect a spectral break due to the
transition from the primary to residual internal shock emission at the
previously thought spectral cutoff, and expect systematic time delays of high
energy photons relative to MeV emission, the discovery of which would provide
stringent constraint on the outflow properties, but requires large enough
collection of high energy photons by, e.g., Fermi and AGILE satellites.
  The recent Fermi-detected bright GRB 080916c unambiguously shows the shifting
of the prompt emission toward later times as the photon energy increases, as
predicted in the residual collision model. The detected prompt, highest energy
photon (about 70 GeV in the rest frame of the GRB) may not be produced by
primary internal shocks but by IC emission in residual collisions. With the
method involving time delays of high energy emission, the bulk Lorentz factor
of GRB 080916c is determined to be \Gamma ~ 300.


title:
Study of moments of event shapes and a determination of \as using \epem
  annihilation data from \Jade

abstract:
  Data from \epem annihilation into hadrons, collected by the \Jade experiment
at centre-of-mass energies between 14 GeV and 44 GeV, are used to study moments
of event shape distributions. Models with hadronisation parameters tuned to the
LEP 1 precision data provide an adequate description of the low energy data
studied here. The NLO QCD calculations, however, show systematic deficiencies
for some of the moments. The strong coupling measured from the moments which
are reasonably described by NLO QCD,
\asmz=0.1287\pm0.0007\stat\pm0.0011\expt\pm0.0022\had\pm0.0075\theo is
consistent with the world average.


title:
Implementing invariant mass cuts and finite lifetime effects in
  top-antitop production at threshold

abstract:
  The effects of the finite top quark width in the top pair production cross
section close to the threshold are discussed in this talk. We introduce a
$t\bar{t}$ cross section with a cut on the invariant masses of the top and
antitop that can be calculated theoretically with effective field theory (EFT)
methods. The matching procedure to implement the physical phase-space
boundaries in the NRQCD framework (``phase-space matching'') is briefly
outlined.


title: Quantum entanglement of space domains occupied by interacting electrons

abstract:
  Spin-entanglement of two electrons occupying two spatial regions -- domains
-- is expressed in a compact form in terms of spin-spin correlation functions.
The power of the formalism is demonstrated on several examples ranging from
generation of entanglement by scattering of two electrons to the entanglement
of a pair of qubits represented by a double quantum dot coupled to leads. In
the latter case the collapse of entanglement due to the Kondo effect is
analyzed.


title:
Manipulating sudden death of entanglement of two-qubit X-states in
  thermal reservoirs

abstract:
  Manipulation of sudden death of entanglement (ESD) of two qubits interacting
with statistically uncorrelated thermal reservoirs is investigated. It is shown
that for initially prepared X-states of the two qubits a simple (necessary and
sufficient) criterion for ESD can be derived with the help of the
Peres-Horodecki criterion. This criterion implies that, in contrast to the
zero-temperature case, at finite temperature of at least one of the reservoirs
all initially prepared two-qubit X-states exhibit ESD. General conditions are
derived under which ESD can be hastened, delayed, or averted.


title: Quantum Random Access Codes with Shared Randomness

abstract:
  We consider a communication method, where the sender encodes n classical bits
into 1 qubit and sends it to the receiver who performs a certain measurement
depending on which of the initial bits must be recovered. This procedure is
called (n,1,p) quantum random access code (QRAC) where p > 1/2 is its success
probability. It is known that (2,1,0.85) and (3,1,0.79) QRACs (with no
classical counterparts) exist and that (4,1,p) QRAC with p > 1/2 is not
possible.
  We extend this model with shared randomness (SR) that is accessible to both
parties. Then (n,1,p) QRAC with SR and p > 1/2 exists for any n > 0. We give an
upper bound on its success probability (the known (2,1,0.85) and (3,1,0.79)
QRACs match this upper bound). We discuss some particular constructions for
several small values of n.
  We also study the classical counterpart of this model where n bits are
encoded into 1 bit instead of 1 qubit and SR is used. We give an optimal
construction for such codes and find their success probability exactly--it is
less than in the quantum case.
  Interactive 3D quantum random access codes are available on-line at
http://home.lanet.lv/~sd20008/racs .


title: Feedback and Rate Asymmetry of the Josephson Junction Noise Detector

abstract:
  The Josephson junction noise detector measures the skewness of non-Gaussian
noise via the asymmetry of the rate of escape from the zero-voltage state upon
reversal of the bias current. The feedback of this detector on the noise
generating device is investigated in detail. Concise predictions are made for a
second Josephson junction as noise generating device. The strong nonlinearity
of this component implies particularly strong feedback effects, including a
change of sign of the rate asymmetry as the applied voltage approaches twice
the superconducting gap.


title:
Power laws in elementary and heavy-ion collisions - A story of
  fluctuations and nonextensivity?

abstract:
  We review from the point of view of nonextensive statistics the ubiquitous
presence in elementary and heavy-ion collisions of power-law distributions.
Special emphasis is placed on the conjecture that this is just a reflection of
some intrinsic fluctuations existing in the hadronic systems considered. These
systems summarily described by a single parameter q playing the role of a
nonextensivity measure in the nonextensive statistical models based on Tsallis
entropy.


title:
Dipolar interactions and thermal stability of two-dimensional
  nanoparticle arrays

abstract:
  We show results of Monte Carlo simulations of an array of monodispersed
magnetic monodomain particles, in a square lattice with dipolar interactions
and perpendicular uniaxial anisotropy. We first show the equilibrium phase
diagram of the system, which shows three phases, superparamagnetic (SP),
out-of-plane antiferromagnetic and in-plane antiferromagnetic with a
reorientation transition between the last two. We then employ a recently
introduced time quantified Monte Carlo method to study the relaxation of
autocorrelations of the particle array for different ratios of dipolar to
anisotropy energies. In the non-interacting case we show that relaxation is
exponential in time with characteristic times obeying a classic result by
Brown. When dipolar interactions are switched on, the relaxation is very well
described by stretched exponential forms in the whole time window and in both
the SP and ordered phases. Relaxation times still obey a nearly Arrhenius
behaviour, with a single effective energy barrier that decreases as the dipolar
interaction increases, a result that must be interpreted within the dynamics
protocol. No signs of glassy behaviour were found, in agreement with the
absence of disorder in the model system.


title:
The Dynamical Behaviour of Test Particles in a Quasi-Spherical Spacetime
  and the Physical Meaning of Superenergy

abstract:
  We calculate the instantaneous proper radial acceleration of test particles
(as measured by a locally defined Lorentzian observer) in a Weyl spacetime,
close to the horizon. As expected from the Israel theorem, there appear some
bifurcations with respect to the spherically symmetric case (Schwarzschild),
which are explained in terms of the behaviour of the superenergy, bringing out
the physical relevance of this quantity in the study of general relativistic
systems.


title:
Magnetic susceptibility of YbRh2Si2 and YbIr2Si2 on the basis of a
  localized 4f electron approach

abstract:
  We consider the local properties of the Yb3+ ion in the crystal electric
field in the Kondo lattice compounds YbRh2Si2 and YbIr2Si2. On this basis we
have calculated the magnetic susceptibility taking into account the Kondo
interaction in the simplest molecular field approximation. The resulting
Curie-Weiss law and Van Vleck susceptibilities could be excellently fitted to
experimental results in a wide temperature interval where thermodynamic and
transport properties show non-Fermi-liquid behaviour for these materials.


title: Adaptive quantum teleportation

abstract:
  We consider multiple teleportation in the Knill-Laflamme-Milburn (KLM)
scheme. We introduce adaptive teleportation, i.e., such that the choice of
entangled state used in the next teleportation depends on the results of the
measurements performed during the previous teleportations. We show that
adaptive teleportation enables an increase in the probability of faithful
multiple teleportation in the KLM scheme. In particular if a qubit is to be
teleported more than once then it is better to use nonmaximally entangled
states than maximally entangled ones in order to achieve the highest
probability of faithful teleportation.


title: Stochastic dynamics of a sheared granular medium

abstract:
  We experimentally investigate the response of a sheared granular medium in a
Couette geometry. The apparatus exhibits the expected stick-slip motion and we
probe it in the very intermittent regime resulting from low driving.
Statistical analysis of the dynamic fluctuations reveals notable regularities.
We observe a possible stability property for the torque distribution,
reminiscent of the stability of Gaussian independent variables. In this case,
however, the variables are correlated and the distribution is skewed. Moreover,
the whole dynamical intermittent regime can be described with a simple
stochastic model, finding good quantitative agreement with the experimental
data. Interestingly, a similar model has been previously introduced in the
study of magnetic domain wall motion, a source of Barkhausen noise. Our study
suggests interesting connections between different complex phenomena and
reveals some unexpected features that remain to be explained.


title:
Self-correspondences of K3 surfaces via moduli of sheaves and arithmetic
  hyperbolic reflection groups

abstract:
  An integral hyperbolic lattice is called reflective if its automorphism group
is generated by reflections, up to finite index. Since 1981, it is known that
their number is essentially finite.
  We show that K3 surfaces over C with reflective Picard lattices can be
characterized in terms of compositions of their self-correspondences via moduli
of sheaves with primitive isotropic Mukai vector: Their self-correspondences
with integral action on the Picard lattice are numerically equivalent to
compositions of a finite number of especially simple self-correspondences via
moduli of sheaves.
  This relates two topics: Self-correspondences of K3 surfaces via moduli of
sheaves and Arithmetic hyperbolic reflection groups. It also raises several
natural unsolved related problems.


title: Gene-gene cooperativity in small networks

abstract:
  We show how to construct a reduced description of interacting genes in noisy,
small regulatory networks using coupled binary "spin" variables. Treating both
the protein number and gene expression state variables stochastically and on
equal footing we propose a mapping which connects the molecular level
description of networks to the binary representation. We construct a phase
diagram indicating when genes can be considered to be independent and when the
coupling between them cannot be neglected leading to synchrony or correlations.
We find that an appropriately mapped boolean description reproduces the
probabilities of gene expression states of the full stochastic system very well
and can be transfered to examples of self-regulatory systems with a larger
number of gene copies.


title: PBG properties of three-component 2D photonic crystals

abstract:
  In this paper we analyze theoretically how the introduction of the third
component into the two-dimensional photonic crystal influences the photonic
band structure and the density-of-states of the system. We consider the
periodic array of cylindrical air rods in a dielectric, and the third medium is
introduced as a ring-shaped intermediate layer between the air pores and the
dielectric background. Using the plane wave method, we have obtained the band
structures for the 2D triangular lattice photonic crystals. The dependencies of
TE and TM band gaps' widths and gaps' edges position on the interlayer
dielectric constant and interlayer thickness were analyzed. In the framework of
this approach, we have estimated the influence of the surface oxide layer on
the band structure of macroporous silicon. We observed the shift of the gaps'
edges to the higher or lower frequencies, depending on the interlayer thickness
and dielectric constant. We have shown that the existence of a native oxide
surface layer should be taken into consideration to understand the optical
properties of 2D photonic crystals, particularly in macroporous silicon
structures.


title: The Double Chooz Experiment

abstract:
  The Double Chooz experiment returns to the site of the Chooz experiment with
a pair of detectors for a differential neutrino flux measurement, providing
sensitivity to sin^2(2theta13) > 0.03. Reaching this goal requires significant
improvements in systematic uncertainties, based on the experience with previous
reactor neutrino experiments.


title: Peres lattices in nuclear structure

abstract:
  A method by Peres is used to draw spectra of the interacting boson model as
lattices in the plane of energy versus an arbitrary observable average (or
variance). Ordered (disordered) lattices are signatures of regularity (chaos)
in both quantum and classical dynamics. The method is also apt to disclose
exact or approximate dynamical symmetry.


title:
Amplification of magnetic fields by dynamo action in Gaussian-correlated
  helical turbulence

abstract:
  We investigate the growth and structure of magnetic fields amplified by
kinematic dynamo action in turbulence with non-zero kinetic helicity. We assume
a simple Gaussian velocity correlation tensor, which allows us to consider very
large magnetic Reynolds numbers, up to one trillion. We use the kinematic
Kazantsev-Kraichnan model of dynamo and find a complete numerical solution for
the correlation functions of growing magnetic fields.


title: Non-extremal fuzzballs and ergoregion emission

abstract:
  In the traditional picture of black holes Hawking radiation is created by
pair creation from the vacuum at the horizon. In the fuzzball proposal,
individual microstates do not have a horizon with the `vacuum' state in its
vicinity. For a special family of non-extremal microstates it was recently
found that emission occurs due to pair creation in an ergoregion, rather than
at a horizon. In this paper we extend this result to a slightly larger class of
microstates, again finding exact agreement between the emission in the gravity
picture and the CFT dual. We write down an expression for emission from
geometries with ergoregions, in terms of the leading falloff behavior of the
wavefunctions in the fuzzball region. Finally, we describe another family of
nonextremal microstates and find their ergoregion.


title:
Energy-momentum tensor for a scalar Casimir apparatus in a weak
  gravitational field: Neumann conditions

abstract:
  We consider a Casimir apparatus consisting of two perfectly conducting
parallel plates, subject to the weak gravitational field of the Earth. The aim
of this paper is the calculation of the energy-momentum tensor of this system
for a free, real massless scalar field satisfying Neumann boundary conditions
on the plates. The small gravity acceleration (here considered as not varying
between the two plates) allows us to perform all calculations to first order in
this parameter. Some interesting results are found: a correction, depending on
the gravity acceleration, to the well-known Casimir energy and pressure on the
plates. Moreover, this scheme predicts a tiny force in the upwards direction
acting on the apparatus. These results are supported by two consistency checks:
the covariant conservation of the energy-momentum tensor and the vanishing of
its regularized trace, when the scalar field is conformally coupled to gravity.


title: On Power Control and Frequency Reuse in the Two User Cognitive Channel

abstract:
  This paper considers the generalized cognitive radio channel where the
secondary user is allowed to reuse the frequency during both the idle and
active periods of the primary user, as long as the primary rate remains the
same. In this setting, the optimal power allocation policy with single-input
single-output (SISO) primary and secondary channels is explored. Interestingly,
the offered gain resulting from the frequency reuse during the active periods
of the spectrum is shown to disappear in both the low and high signal-to-noise
ratio (SNR) regimes. We then argue that this drawback in the high SNR region
can be avoided by equipping both the primary and secondary transmitters with
multiple antennas. Finally, the scenario consisting of SISO primary and
multi-input multi-output (MIMO) secondary channels is investigated. Here, a
simple Zero-Forcing approach is shown to significantly outperform the
celebrated Decoding-Forwarding-Dirty Paper Coding strategy (especially in the
high SNR regime).


title: Quasispecies Theory for Horizontal Gene Transfer and Recombination

abstract:
  We introduce a generalization of the parallel, or Crow-Kimura, and Eigen
models of molecular evolution to represent the exchange of genetic information
between individuals in a population. We study the effect of different schemes
of genetic recombination on the steady-state mean fitness and distribution of
individuals in the population, through an analytic field theoretic mapping. We
investigate both horizontal gene transfer from a population and recombination
between pairs of individuals. Somewhat surprisingly, these nonlinear
generalizations of quasi-species theory to modern biology are analytically
solvable. For two-parent recombination, we find two selected phases, one of
which is spectrally rigid. We present exact analytical formulas for the
equilibrium mean fitness of the population, in terms of a maximum principle,
which are generally applicable to any permutation invariant replication rate
function. For smooth fitness landscapes, we show that when positive epistatic
interactions are present, recombination or horizontal gene transfer introduces
a mild load against selection. Conversely, if the fitness landscape exhibits
negative epistasis, horizontal gene transfer or recombination introduce an
advantage by enhancing selection towards the fittest genotypes. These results
prove that the mutational deterministic hypothesis holds for quasi-species
models. For the discontinuous single sharp peak fitness landscape, we show that
horizontal gene transfer has no effect on the fitness, while recombination
decreases the fitness, for both the parallel and the Eigen models. We present
numerical and analytical results as well as phase diagrams for the different
cases.


title:
Lagrangian Structure Functions in Turbulence: Scaling Exponents and
  Universality

abstract:
  In this paper, the approach for investigation of asymptotic ($Re\to \infty$)
scaling exponents of Eulerian structure functions (J. Schumacher et al, New. J.
of Physics {\bf 9}, 89 (2007)) is generalized to studies of Lagrangian
structure functions in turbulence. The novel "bridging relation" based on the
derived expression for the fluctuating, moment-order - dependent dissipation
time $\tau_{\eta,n}$ enabled us to calculate scaling exponents ($\kappa_{n}$)
of the moments of Lagrangian velocity differences
$S_{n,L}(\tau)=\bar{(u(t+\tau)-u(t))^{n}}\propto \tau^{\kappa_{n}}$ in a good
agreement with experimental and numerical data.


title:
A liquid Xenon Positron Emission Tomograph for small animal imaging :
  first experimental results of a prototype cell

abstract:
  A detector using liquid Xenon (LXe) in the scintillation mode is studied for
Positron Emission Tomography (PET) of small animals. Its specific design aims
at taking full advantage of the Liquid Xenon scintillation properties. This
paper reports on energy, time and spatial resolution capabilities of the first
LXe prototype module equipped with a Position Sensitive Photo- Multiplier tube
(PSPMT) operating in the VUV range (178 nm) and at 165 K. The experimental
results show that such a LXe PET configuration might be a promising solution
insensitive to any parallax effect.


title: Mid-Infrared Properties of Disk Averaged Observations of Earth with AIRS

abstract:
  We have investigated mid-infrared spectra of Earth obtained by the
Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to
explore the characteristics that may someday be observed in extrasolar
terrestrial planets. We have used the AIRS infrared (R ~ 1200; 3.75-15.4
microns) spectra to construct directly-observed high-resolution spectra of the
only known life bearing planet, Earth. The AIRS spectra are the first such
spectra that span the seasons. We investigate the rotational and seasonal
spectral variations that would arise due to varying cloud amount and viewing
geometry and we explore what signatures may be observable in the mid-infrared
by the next generation of telescopes capable of observing extrasolar
terrestrial planets.


title:
Competition between Anderson localization and antiferromagnetism in
  correlated lattice fermion systems with disorder

abstract:
  The magnetic ground state phase diagram of the disordered Hubbard model at
half-filling is computed in dynamical mean-field theory supplemented with the
spin resolved, typical local density of states. The competition between
many-body correlations and disorder is found to stabilize paramagnetic and
antiferromagnetic metallic phases at weak interactions. Strong disorder leads
to Anderson localization of the electrons and suppresses the antiferromagnetic
long-range order. Slater and Heisenberg antiferromagnets respond
characteristically different to disorder. The results can be tested with cold
fermionic atoms loaded into optical lattices.


title: Diquark correlations in baryon spectroscopy and holographic QCD

abstract:
  We introduce an improved mass formula for the nucleon and delta resonances
and show how it emerges from AdS/QCD in a straightforward extension of the
'metric soft wall' gravity dual. The resulting spectrum depends on just one
adjustable parameter, characterizing confinement-induced IR deformations of the
anti-de Sitter (AdS) metric, and on the fraction of 'good' (i.e. maximally
attractive) diquarks in the baryon's quark model wave function. Despite its
simplicity, the predicted spectrum describes the masses of all 48 observed
light-quark baryon states and their linear trajectory structure with
unprecedented accuracy.


title:
Observation of collective excitation of two individual atoms in the
  Rydberg blockade regime

abstract:
  The dipole blockade between Rydberg atoms has been proposed as a basic tool
in quantum information processing with neutral atoms. Here we demonstrate
experimentally the Rydberg blockade of two individual atoms separated by 4
$\mu$m. Moreover, we show that, in this regime, the single atom excitation is
enhanced by a collective two-atom behavior associated with the excitation of an
entangled state. This observation is a crucial step towards the deterministic
manipulation of entanglement of two or more atoms using the Rydberg dipole
interaction.


title:
Deceleration of arbitrarily magnetized GRB ejecta: the complete
  evolution

abstract:
  (Abridged) We aim to quantitatively understand the dynamical effect and
observational signatures of magnetization of the GRB ejecta on the onset of the
afterglow. We perform ultrahigh-resolution one-dimensional relativistic MHD
simulations of the interaction of a radially expanding, magnetized ejecta with
the interstellar medium. The need of ultrahigh numerical resolution derives
from the extreme jump conditions in the region of interaction between the
ejecta and the circumburst medium. We study the evolution of an
ultrarelativistic shell all the way to a the self-similar asymptotic phase. Our
simulations show that the complete evolution can be characterized in terms of
two parameters, namely, the \xi parameter introduced by Sari & Piran (1995) and
the magnetization \sigma_0. We exploit this property by producing numerical
models where the shell Lorentz factor is \gamma_0 ~ tens and rescaling the
results to arbitrarily large \gamma_0. We find that the reverse shock is
typically very weak or absent for ejecta characterized by \sigma_0 >~ 1. The
onset of the forward shock emission is strongly affected by the magnetization.
On the other hand, the magnetic energy of the shell is transfered to the
external medium on a short timescale (~several times the duration of the
burst). The later forward shock emission does not contain information for the
initial magnetization of the flow. The asymptotic evolution of strongly
magnetized shells, after they have suffred a substantial deceleration,
resembles that of hydrodynamic shells, i.e., they fully enter in the
Blandford-McKee self-similar regime.


title: Electron tunneling into a quantum wire in the Fabry-Perot regime

abstract:
  We study a gated quantum wire contacted to source and drain electrodes in the
Fabry-Perot regime. The wire is also coupled to a third terminal (tip), and we
allow for an asymmetry of the tip tunneling amplitudes of right and left moving
electrons. We analyze configurations where the tip acts as an electron injector
or as a voltage-probe, and show that the transport properties of this
three-terminal set-up exhibit very rich physical behavior. For a
non-interacting wire we find that a tip in the voltage-probe configuration
affects the source-drain transport in different ways, namely by suppressing the
conductance, by modulating the Fabry-Perot oscillations, and by reducing their
visibility. The combined effect of electron electron interaction and finite
length of the wire, accounted for by the inhomogeneous Luttinger liquid model,
leads to significantly modified predictions as compared to models based on
infinite wires. We show that when the tip injects electrons asymmetrically the
charge fractionalization induced by interaction cannot be inferred from the
asymmetry of the currents flowing in source and drain. Nevertheless interaction
effects are visible as oscillations in the non-linear tip-source and tip-drain
conductances. Important differences with respect to a two-terminal set-up
emerge, suggesting new strategies for the experimental investigation of
Luttinger liquid behavior.


title:
Revisiting the theoretical DBV (V777 Her) instability strip: the MLT
  theory of convection

abstract:
  We reexamine the theoretical instability domain of pulsating DB white dwarfs
(DBV or V777 Her variables). We performed an extensive $g$-mode nonadiabatic
pulsation analysis of DB evolutionary models considering a wide range of
stellar masses, for which the complete evolutionary stages of their progenitors
from the ZAMS, through the thermally pulsing AGB and born-again phases, the
domain of the PG1159 stars, the hot phase of DO white dwarfs, and then the DB
white dwarf stage have been considered. We explicitly account for the evolution
of the chemical abundance distribution due to time-dependent chemical diffusion
processes. We examine the impact of the different prescriptions of the MLT
theory of convection and the effects of small amounts of H in the almost
He-pure atmospheres of DB stars on the precise location of the theoretical blue
edge of the DBV instability strip.


title: One-Loop Gluonic Amplitudes from Single Unitarity Cuts

abstract:
  We show that one-loop amplitudes in massless gauge theories can be determined
from single cuts. By cutting a single propagator and putting it on-shell, the
integrand of an n-point one-loop integral is transformed into an (n+2)-particle
tree level amplitude. The single-cut approach described here is complementary
to the double or multiple unitarity cut approaches commonly used in the
literature. In common with these approaches, if the cut is taken in four
dimensions, one finds only the cut-constructible parts of the amplitude, while
if the cut is in D=4-2 epsilon dimensions, both rational and cut-constructible
parts are obtained. We test our method by reproducing the known results for the
fully rational all-plus and mostly-plus QCD amplitudes
A^{(1)}_4(1^+,2^+,3^+,4^+) and A^{(1)}_5(1^+,2^+,3^+,4^+,5^+). We also rederive
expressions for the scalar loop contribution to the four-gluon MHV amplitude,
A_4^{(1,N=0)}(-,-,+,+) which has both cut-constructible and rational
contributions, and the fully cut-constructible n-gluon MHV amplitude in N=4
Supersymetric Yang-Mills, A_4^{(1,N=4)}(-,-,+,...,+).


title: The absolutely continuous spectrum of the almost Mathieu operator

abstract:
  We prove that the spectrum of the almost Mathieu operator is absolutely
continuous if and only if the coupling is subcritical. This settles Problem 6
of Barry Simon's list of Schr\"odinger operator problems for the twenty-first
century.


title: CP Violation in Hadronic Penguins at BABAR

abstract:
  We present preliminary measurements of time-dependent CP-violation parameters
in the decays B0->omegaK0S, B0->eta'K0, B0->pi0K0S, B0->phiK0Spi0, and
B0->K+K-K0S, which includes the resonant final states phiK0S and f0(980)K0S.
The data sample corresponds to the full BABAAR dataset of 467 million BBbar
pairs produced at the PEP-II asymmetric-energy e+e- collider at the Stanford
Linear Accelerator Center.