title: Rumsfeld Hadrons

abstract:
  Donald Rumsfeld, in attempting to excuse the inexcusable, once (in)famously
said that ``there are things that we know we know; there are things that we
know we don't know; and then there are things that we don't know that we don't
know". Recent discoveries about hadrons with heavy flavours fall into those
categories. It is of course the third category that is the most tantalising,
but lessons from the first two may help resolve the third.


title:
Compulsory Deep Mixing of 3He and CNO Isotopes in the Envelopes of
  low-mass Red Giants

abstract:
  Three-dimensional stellar modeling has enabled us to identify a deep-mixing
mechanism that must operate in all low mass giants. This mixing process is not
optional, and is driven by a molecular weight inversion created by the
3He(3He,2p)4He reaction. In this paper we characterize the behavior of this
mixing, and study its impact on the envelope abundances. It not only eliminates
the problem of 3He overproduction, reconciling stellar and big bang
nucleosynthesis with observations, but solves the discrepancy between observed
and calculated CNO isotope ratios in low mass giants, a problem of more than 3
decades' standing. This mixing mechanism, which we call `$\delta\mu$-mixing',
operates rapidly (relative to the nuclear timescale of overall evolution, ~
10^8 yrs) once the hydrogen burning shell approaches the material homogenized
by the surface convection zone. In agreement with observations, Pop I stars
between 0.8 and 2.0$\Msun$ develop 12C/13C ratios of 14.5 +/- 1.5, while Pop II
stars process the carbon to ratios of 4.0 +/- 0.5. In stars less than
1.25$\Msun$, this mechanism also destroys 90% to 95% of the 3He produced on the
main sequence.


title: On the Descent Algebra of Type $D$

abstract:
  Here we give a combinatorial interpretation of Solomon's rule for
multiplication in the descent algebra of Weyl groups of type $D$, $\Sigma D_n$.
  From here we show that $\Sigma D_n$ is a homomorphic image of the descent
algebra of the hyperoctahedral group, $\Sigma B_{n-2}$.


title:
Morphological Dependence of MIR Properties of SDSS Galaxies in the
  Spitzer SWIRE Survey

abstract:
  We explore the correlation between morphological types and mid-infrared (MIR)
properties of an optically flux-limited sample of 154 galaxies from the Forth
Data Release (DR4) of Sloan Digital Sky Survey (SDSS), cross-correlated with
Spitzer SWIRE (Spitzer Wide-Area InfraRed Extragalactic Survey) fields of
ELAIS-N1, ELAIS-N2 and Lockman Hole. Aperture photometry is performed on the
SDSS and Spitzer images to obtain optical and MIR properties. The morphological
classifications are given based on both visual inspection and bulge-disk
decomposition on SDSS g- and r-band images. The average bulge-to-total ratio
(B/T) is a smooth function over different morphological types. Both the
8um(dust) and 24um(dust) luminosities and their relative luminosity ratios to
3.6um (MIR dust-to-star ratios) present obvious correlations with both the
Hubble T-type and B/T. The early-type galaxies notably differ from the
late-types in the MIR properties, especially in the MIR dust-to-star ratios. It
is suggested that the MIR dust-to-star ratio is an effective way to separate
the early-type galaxies from the late-type ones. Based on the tight correlation
between the stellar mass and the 3.6um luminosity, we have derived a formula to
calculate the stellar mass from the latter. We have also investigated the MIR
properties of both edge-on galaxies and barred galaxies in our sample. Since
they present similar MIR properties to the other sample galaxies, they do not
influence the MIR properties obtained for the entire sample.


title: Contraction groups in complete Kac-Moody groups

abstract:
  Let $G$ be an abstract Kac-Moody group over a finite field and $\bar{G}$ be
the closure of the image of $G$ in the automorphism group of its positive
building. We show that if the Dynkin diagram associated to $G$ is irreducible
and neither of spherical nor of affine type, then the contraction groups of
elements in $\bar{G}$ which are not topologically periodic are not closed. (In
those groups there always exist elements which are not topologically periodic.)


title: A Proof of Solomon's Rule

abstract:
  We put forward a proof of Solomon's rule, in terms of matrices, for
multiplication in the descent algebra of the symmetric group. Our proof
exploits the graphs that we can obtain from all the subsets of the set of
transpositions, $\{(i,i+1)\}_{i=1}^{n-1}$.


title: Holographic trace anomaly at finite temperature

abstract:
  We find an exact coordinate transformation rule from the $AdS_5$
Schwarzschild black hole in the Poincare and the global patch to the
Fefferman-Graham coordinate system. Using these results, we evaluate the
corresponding holographic stress tensor and trace anomaly of the boundary
theory as a function of the radial coordinate. Following the AdS/CFT
correspondence, we reinterpret the radial coordinate dependence of the trace
anomaly as the Wilsonian renormalization group(RG) flow of the boundary theory.


title: Fusion algebra of critical percolation

abstract:
  We present an explicit conjecture for the chiral fusion algebra of critical
percolation considering Virasoro representations with no enlarged or extended
symmetry algebra. The representations we take to generate fusion are countably
infinite in number. The ensuing fusion rules are quasi-rational in the sense
that the fusion of a finite number of these representations decomposes into a
finite direct sum of these representations. The fusion rules are commutative,
associative and exhibit an sl(2) structure. They involve representations which
we call Kac representations of which some are reducible yet indecomposable
representations of rank 1. In particular, the identity of the fusion algebra is
a reducible yet indecomposable Kac representation of rank 1. We make detailed
comparisons of our fusion rules with the recent results of Eberle-Flohr and
Read-Saleur. Notably, in agreement with Eberle-Flohr, we find the appearance of
indecomposable representations of rank 3. Our fusion rules are supported by
extensive numerical studies of an integrable lattice model of critical
percolation. Details of our lattice findings and numerical results will be
presented elsewhere.

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


title: Newton's 2nd Law and the Physics of Dance

abstract:
  In teaching the physical sciences, a significant challenge lies in the
student's tendency to consider the scientific world and the "real" world as
separate. For example, Newton's 1st Law of Motion states that an object in
motion remains in motion in a straight line unless acted on by an external
force. However, our experience tells us that most objects keep moving only as
long as someone or something pushes on them. One key to understanding physics
is the ability to abstract the "law" from a reality which also includes
friction and other effects. In this article we describe a college course for
non-science majors, The Physics of Dance. The central theme of this course is
the personalization of the physics of motion by making each student the object.
With this approach we give students not only scientific tools to measure and
understand but personal involvement to experience forces and motion. This
combination provides a bridge that connects the science to reality.


title: Universally defined representations of Lie conformal superalgebras

abstract:
  We distinguish a class of irreducible finite representations of conformal Lie
(super)algebras. These representations (called universally defined) are the
simplest ones from the computational point of view: a universally defined
representation of a conformal Lie (super)algebra $L$ is completely determined
by commutation relations of $L$ and by the requirement of associative locality
of generators. We describe such representations for conformal superalgebras
$W_n$, $n\ge 0$, with respect to a natural set of generators. We also consider
the problem for superalgebras $K_n$. In particular, we find a universally
defined representation for the Neveu--Schwartz conformal superalgebra $K_1$ and
show that the analogues of this representation for $n\ge 2$ are not universally
defined.


title: Do All Integrable Evolution Equations Have the Painlev\'e Property?

abstract:
  We examine whether the Painleve property is necessary for the integrability
of partial differential equations (PDEs). We show that in analogy to what
happens in the case of ordinary differential equations (ODEs) there exists a
class of PDEs, integrable through linearisation, which do not possess the
Painleve property. The same question is addressed in a discrete setting where
we show that there exist linearisable lattice equations which do not possess
the singularity confinement property (again in analogy to the one-dimensional
case).


title: Small Deviation Probability via Chaining

abstract:
  We obtain several extensions of Talagrand's lower bound for the small
deviation probability using metric entropy. For Gaussian processes, our
investigations are focused on processes with sub-polynomial and, respectively,
exponential behaviour of covering numbers. The corresponding results are also
proved for non-Gaussian symmetric stable processes, both for the cases of
critically small and critically large entropy. The results extensively use the
classical chaining technique; at the same time they are meant to explore the
limits of this method.


title: Associative algebras related to conformal algebras

abstract:
  In this note, we introduce a class of algebras that are in some sense related
to conformal algebras. This class (called TC-algebras) includes Weyl algebras
and some of their (associative and Lie) subalgebras. By a conformal algebra we
generally mean what is known as $H$-pseudo-algebra over the polynomial Hopf
algebra $H=\Bbbk[T_1,..., T_n]$. Some recent results in structure theory of
conformal algebras are applied to get a description of TC-algebras.


title: Three-jet event-shapes: first NLO+NLL+1/Q results

abstract:
  Three-jet event-shape distributions can be exploited to investigate the
dependence of hadronisation effects on the colour and the geometry of the
underlying hard event. We present here the first comparison of data in e+e-
annihilation and state-of-the-art theoretical predictions, including
resummation of large logarithms at next-to-leading logarithmic accuracy matched
to exact next-to-leading order and leading non-perturbative power corrections.


title:
Mass segregation in very young open clusters -- A case study of NGC 2244
  and NGC 6530

abstract:
  We derive the proper motions, membership probabilities, and velocity
dispersions of stars in the regions of the young (about 2-4 Myr-old) open
clusters NGC 2244 (the central cluster in the Monoceros R2 association) and NGC
6530 (the dominant cluster in the Sgr OB1 association) from photographic plate
material obtained at Shanghai Astronomical Observatory, with time baselines of
34 and 87 years, respectively. Both clusters show clear evidence of mass
segregation, but they do not exhibit any significant velocity-mass (or,
equivalently, a velocity-luminosity) dependence. This provides strong support
for the suggestion that the observed mass segregation is -- at least partially
-- due to the way in which star formation has proceeded in these complex
star-forming regions (``primordial'' mass segregation). Based on arguments
related to the clusters' published initial mass functions, in conjunction with
our new measurements of their internal velocity dispersions (35 and 8 km/s for
NGC 2244 and NGC 6530, respectively), we provide strong arguments in favor of
the dissolution of NGC 2244 on very short time-scales, while we speculate that
NGC 6530 may be more stable against the effects of internal two-body
relaxation. However, this latter object may well be destroyed by the strong
tidal field prevalent at its location in the Galactic plane in the direction of
the Galactic Center.


title:
A search for ultra-compact dwarf galaxies in the Centaurus galaxy
  cluster

abstract:
  Aim: To extend the investigations of ultra-compact dwarf galaxies (UCDs)
beyond the well studied Fornax and Virgo clusters. Methods: We measured
spectroscopic redshifts of about 400 compact object candidates with 19.2 < V <
22.4 mag in the central region of the Centaurus galaxy cluster (d=43Mpc), using
VIMOS@VLT. The luminosity range of the candidates covers that of bright
globular clusters (GCs) and of UCDs in Fornax and Virgo. Results: We confirm
the cluster membership of 27 compact objects, covering an absolute magnitude
range -12.2 < M_V < -10.9 mag. We do not find counterparts to the two very
large and bright UCDs in Fornax and Virgo with M_V=-13.5 mag, possibly due to
survey incompleteness. The compact objects' distribution in magnitude and space
is consistent with that of the GC population. Their kinematics and spatial
distribution associate them to the central galaxies rather than to the overall
cluster potential. The compact objects have a mean metallicity consistent with
that of the metal-rich globular cluster sub-population. Compact objects with
high S/N spectra exhibit solar [alpha/Fe] abundances, consistent with typical
dwarf elliptical galaxy values and unlike galactic bulge globular clusters. HST
based size estimates for a sub-sample of eight compact objects reveal the
existence of one very large object with half-light radius r_h around 30 pc,
having M_V=-11.6 mag (~10^7 M_sun). This source shows super-solar [alpha/Fe]
abundances. Seven further sources are only marginally larger than typical GCs
with r_h in the range 4 to 10 pc. Conclusions: We consider the largest compact
object found to be the only bona-fide UCD detected in our study. In order to
improve our understanding of UCDs in Centaurus, a significant increase of our
survey completeness is necessary.


title: The Complexity of Determining Existence a Hamiltonian Cycle is $O(n^3)$

abstract:
  The Hamiltonian cycle problem in digraph is mapped into a matching cover
bipartite graph. Based on this mapping, it is proved that determining existence
a Hamiltonian cycle in graph is $O(n^3)$.


title:
Probing the Role of the Barrier Layer in Magnetic Tunnel Junction
  Transport

abstract:
  Magnetic tunnel junctions with a ferrimagnetic barrier layer have been
studied to understand the role of the barrier layer in the tunneling process -
a factor that has been largely overlooked until recently. Epitaxial oxide
junctions of highly spin polarized La0.7Sr0.3MnO3 and Fe3O4 electrodes with
magnetic NiMn2O4 (NMO) insulating barrier layers provide a magnetic tunnel
junction system in which we can probe the effect of the barrier by comparing
junction behavior above and below the Curie temperature of the barrier layer.
When the barrier is paramagnetic, the spin polarized transport is dominated by
interface scattering and surface spin waves; however, when the barrier is
ferrimagnetic, spin flip scattering due to spin waves within the NMO barrier
dominates the transport.


title: Truly naked spherically-symmetric and distorted black holes

abstract:
  We demonstrate the existence of spherically-symmetric truly naked black holes
(TNBH) for which the Kretschmann scalar is finite on the horizon but some
curvature components including those responsible for tidal forces as well as
the energy density $\bar{\rho}$ measured by a free-falling observer are
infinite. We choose a rather generic power-like asymptotics for the metric
functions and analyze possible types of a horizon depending on the behavior of
curvature components in the free-falling frame. It is also shown in a general
case of distorted black holes that $\bar{\rho}$ and tidal forces are either
both finite or both infinite. The general approach developed in the article
includes previously found examples and, in particular, TNBHs with an infinite
area of a horizon. The fact that the detection of singularity depends on a
frame may be relevant for a more accurate definition of the cosmic censorship
conjecture. TNBHs may be considered as a new example of so-called non-scalar
singularities for which the scalar curvature invariants are finite but some
components of the Riemann tensor may diverge in certain frames.


title: Jet Areas, and What They are Good For

abstract:
  We introduce the concept of the area of a jet, and show how it can be used to
perform the subtraction of even a large amount of diffuse noise from hard jets.


title:
Polarization dependence of emission spectra of multiexcitons in
  self-assembled quantum dots

abstract:
  We have investigated the polarization dependence of the emission spectra of
p-shell multiexcitons of a quantum dot when the single particle level spacing
is larger than the characteristic energy of the Coulomb interactions. We find
that there are many degenerate multiexciton states. The emission intensities
depend on the number of degenerate initial and final states of the optical
transitions. However, unlike the transition energies, they are essentially
independent of the strength of the Coulomb interactions. In the presence of
electron-hole symmetry the independence is exact.


title:
Charge Exchange Spin-Dipole Excitations of 90Zr and 208Pb and Neutron
  Matter Equation of State

abstract:
  Charge exchange spin-dipole (SD) excitations of $^{90}$Zr and $^{208}$Pb are
studied by using a Skyrme
  Hartree-Fock(HF) + Random Phase approximation (RPA). The calculated
spin-dipole strength distributions are compared with experimental data obtained
by $^{90}$Zr (p,n) $^{90}$Nb and $^{90}$Zr (n,p) $^{90}$ Nb reactions. The
model-independent SD sum rule values of various Skyrme interactions are studied
in comparison with the experimental values in order to determine the neutron
skin thickness of $^{90}$Zr. The pressure of the neutron matter equation of
state (EOS) and the nuclear matter symmetry energy are discussed in terms of
the neutron skin thickness and peak energies of SD strength distributions.


title:
On the behavior of Castelnuovo-Mumford regularity with respect to some
  functors

abstract:
  We investigate the behavior of Castelnuovo-Mumford regularity with respect to
some classical functors : Tor, the Frobenius functor in positive
characteristic, taking a power or a product (on ideals). These generalizes and
refines previous results on these issues by several authors. As an application
we provide results on the regularity of an intersection of subschemes of a
projective scheme, under appropriate geometric hypotheses. Results on the
rigidity of multiple Tor modules and on the characterization of their vanishing
are given, motivated by geometric applications.


title: A Design Methodology for Space-Time Adapter

abstract:
  This paper presents a solution to efficiently explore the design space of
communication adapters. In most digital signal processing (DSP) applications,
the overall architecture of the system is significantly affected by
communication architecture, so the designers need specifically optimized
adapters. By explicitly modeling these communications within an effective
graph-theoretic model and analysis framework, we automatically generate an
optimized architecture, named Space-Time AdapteR (STAR). Our design flow inputs
a C description of Input/Output data scheduling, and user requirements
(throughput, latency, parallelism...), and formalizes communication constraints
through a Resource Constraints Graph (RCG). The RCG properties enable an
efficient architecture space exploration in order to synthesize a STAR
component. The proposed approach has been tested to design an industrial data
mixing block example: an Ultra-Wideband interleaver.


title: Ultrasoft contribution to quarkonium production and annihilation

abstract:
  We compute the third-order correction to electromagnetic
  S-wave quarkonium production and annihilation rates due to the emission and
absorption of an ultrasoft gluon. Our result completes the analysis of the
non-relativistic quarkonium bound-state dynamics in the
next-to-next-to-next-to-leading order. The impact of the ultrasoft correction
on the Upsilon(1S) leptonic width and the top quark-antiquark threshold
production cross section is estimated.


title: Towards a realistic neutrino mass formula: part two

abstract:
  A two-parameter neutrino mass formula is described, giving a moderately
hierarchical spectrum m_1 < m_2 < m_3 consistent with the experimental
estimates of Delta m^2_{21} and Delta m^2_{32}. The formula follows from a
three-parameter empirical neutrino mass formula through imposing a parameter
constraint and leads to a very simple neutrino mass sum rule m_3 = 18 m_2 - 48
m_1. Some alternative parameter constraints, used tentatively to eliminate one
of three parameters, are compared.


title: Sums of $L$-functions over the rational function field

abstract:
  Friedberg, Hoffstein and Lieman have constructed two related multiple
Dirichlet series from quadratic and higher-order $L$-functions and Gauss sums.
We compute these multiple Dirichlet series explicitly in the case of the
rational function field. This is done by utilizing the functional equation of
the $L$-functions and the functional equation relating the two multiple
Dirichlet series. We also point out a very simple correspondence between these
series and their $p$-parts.


title: Topological gravitation on graph manifolds

abstract:
  A model of topological field theory is presented in which the vacuum coupling
constants are topological invariants of the four-dimensional spacetime. Thus
the coupling constants are theoretically computable, and they indicate the
topological structure of our universe.


title: Constraints on the DGP Universe Using Observational Hubble parameter

abstract:
  In this work, we use observations of the Hubble parameter from the
differential ages of passively evolving galaxies and the recent detection of
the Baryon Acoustic Oscillations (BAO) at $z_1=0.35$ to constrain the
Dvali-Gabadadze-Porrati (DGP) universe. For the case with a curvature term, we
set a prior $h=0.73\pm0.03$ and the best-fit values suggest a spatially closed
Universe. For a flat Universe, we set $h$ free and we get consistent results
with other recent analyses.


title:
Two-Loop Massive Operator Matrix Elements for Polarized and Unpolarized
  Deep-Inelastic Scattering

abstract:
  The $O(\alpha_s^2)$ massive operator matrix elements for unpolarized and
polarized heavy flavor production at asymptotic values $Q^2 >> m^2$ are
calculated in Mellin space without applying the integration-by-parts method. We
confirm previous results given in Refs. \cite{BU1,BU2}, however, obtain much
more compact representations.


title: Measuring the Balmer Jump and Effective Gravity in FGK Stars

abstract:
  It is difficult to accurately measure the effective gravity (log g) in
late-type stars using broadband (eg. UBV or SDSS) or intermediate-band (uvby)
photometric systems, especially when the stars can cover a range of
metallicities and reddenings. However, simple spectroscopic observational and
data reduction techniques can yield accurate values for log g through
comparison of the Balmer jumps of low-resolution spectra with recent grids of
synthetic flux spectra.


title: Mapping Class Groups and Interpolating Complexes: Rank

abstract:
  A family of interpolating graphs $\calC (S, \xi)$ of complexity $\xi$ is
constructed for a surface $S$ and $-2 \leq \xi \leq \xi (S)$. For $\xi = -2,
-1, \xi (S) -1$ these specialise to graphs quasi-isometric to the marking
graph, the pants graph and the curve graph respectively. We generalise Theorems
of Brock-Farb and Behrstock-Minsky to show that the rank of $\calC (S, \xi)$ is
$r_\xi$, the largest number of disjoint copies of subsurfaces of complexity
greater than $\xi $ that may be embedded in $S$. The interpolating graphs
$\calC (S, \xi)$ interpolate between the pants graph and the curve graph.


title: Study of Triple-Gauge-Boson Couplings ZZZ, ZZgam and Zgamgam at LEP

abstract:
  Neutral triple-gauge-boson couplings ZZZ, ZZgam and Zgamgam have been studied
with the DELPHI detector using data at energies between 183 and 208 GeV. Limits
are derived on these couplings from an analysis of the reactions e+e- -> Zgam,
using data from the final states gamma f fbar, with f = q or neutrino, from
e+e- -> ZZ, using data from the four-fermion final states q qbar q qbar, q qbar
mu+ mu-, q qbar e+ e-, q qbar nu nubar, mu+ mu- nu nubar and e+ e- nu nubar,
and from e+e- -> Zgam*, in which the final state gamma is off mass-shell, using
data from the four-fermion final states q qbar e+ e- and q qbar mu+ mu-. No
evidence for the presence of such couplings is observed, in agreement with the
predictions of the Standard Model.


title: Closed String Tachyons on AdS Orbifolds and Dual Yang-Mills Instantons

abstract:
  We study the condensation of localized closed string tachyons on AdS
orbifolds both from the bulk and boundary theory viewpoints. We first extend
the known results for AdS_5/Z_k to AdS_3/Z_k case, and we proposed that the
AdS_3/Z_k decays into AdS_3/Z_k' with k' < k. From the bulk viewpoint, we
obtain a time-dependent gravity solution describing the decay of AdS orbifold
numerically. From the dual gauge theory viewpoint, we calculated the Casimir
energies of gauge theory vacua and it is found that their values are exactly
the same as the masses of dual geometries, even though they are in different
parameter regimes of 't Hooft coupling. We also consider AdS_5 orbifold. The
decay of AdS_5/Z_k is dual to the transition between the dual gauge theory
vacua on R_t x S^3/Z_k, parametrized by different holonomies along the
orbifolded spatial cycle. We constructed the instanton solutions describing the
transitions by making use of instanton solutions on R_t x S^2.


title: Obtaining New Dividing Formulas n|Q(n) From the Known Ones

abstract:
  In this note, we present a few methods (Theorems 1, 2, and 3) from discrete
dynamical systems theory of obtaining new functions Q(n) from the known ones so
that the dividing formulas n|Q(n) hold.


title:
Dynamical instabilities of Bose-Einstein condensates at the band-edge in
  one-dimensional optical lattices

abstract:
  We report on experiments that demonstrate dynamical instability in a
Bose-Einstein condensate at the band-edge of a one-dimensional optical lattice.
The instability manifests as rapid depletion of the condensate and conversion
to a thermal cloud. We consider the collisional processes that can occur in
such a system, and perform numerical modeling of the experiments using both a
mean-field and beyond mean-field approach. We compare our numerical results to
the experimental data, and find that the Gross-Pitaevskii equation is not able
to describe this experiment. Our beyond mean-field approach, known as the
truncated Wigner method, allows us to make quantitative predictions for the
processes of parametric growth and thermalization that are observed in the
laboratory, and we find good agreement with the experimental results.


title:
Hubble Space Telescope Imaging of the Expanding Nebular Remnant of the
  Recurrent Nova RS Ophiuchi (2006)

abstract:
  We report Hubble Space Telescope imaging obtained 155 days after the 2006
outburst of RS Ophiuchi. We detect extended emission in both [O III] and [Ne V]
lines. In both lines, the remnant has a double ring structure. The E-W
orientation and total extent of these structures (580+-50 AU at d=1.6kpc) is
consistent with that expected due to expansion of emitting regions imaged
earlier in the outburst at radio wavelengths. Expansion at high velocity
appears to have been roughly constant in the E-W direction (v_{exp} = 3200+-300
km/s in the plane of the sky), with tentative evidence of deceleration N-S. We
present a bipolar model of the remnant whose inclination is consistent with
that of the central binary. The true expansion velocities of the polar
components are then v = 5600+-1100 km/s. We suggest that the bipolar morphology
of the remnant results from interaction of the outburst ejecta with a
circumstellar medium that is significantly denser in the equatorial regions of
the binary than at the poles. This is also consistent with observations of
shock evolution in the X-ray and the possible presence of dust in the infrared.
Furthermore, it is in line with models of the shaping of planetary nebulae with
close binary central systems, and also with recent observations relating to the
progenitors of Type Ia supernovae, for which recurrent novae are a proposed
candidate. Our observations also reveal more extended structures to the S and E
of the remnant whose possible origin is briefly discussed.


title: Abstract Storage Devices

abstract:
  A quantum storage device differs radically from a conventional physical
storage device. Its state can be set to any value in a certain (infinite) state
space, but in general every possible read operation yields only partial
information about the stored state.
  The purpose of this paper is to initiate the study of a combinatorial
abstraction, called abstract storage device (ASD), which models deterministic
storage devices with the property that only partial information about the state
can be read, but that there is a degree of freedom as to which partial
information should be retrieved.
  This concept leads to a number of interesting problems which we address, like
the reduction of one device to another device, the equivalence of devices,
direct products of devices, as well as the factorization of a device into
primitive devices. We prove that every ASD has an equivalent ASD with minimal
number of states and of possible read operations. Also, we prove that the
reducibility problem for ASD's is NP-complete, that the equivalence problem is
at least as hard as the graph isomorphism problem, and that the factorization
into binary-output devices (if it exists) is unique.


title: Cosmic strings and Natural Inflation

abstract:
  In the present work we discuss cosmic strings in natural inflation. Our
analysis is based entirely on the CMB quadrupole temperature anisotropy and on
the existing upper bound on the cosmic string tension. Our results show that
the allowed range for both parameters of the inflationary model is very
different from the range obtained recently if cosmic strings are formed at the
same time with inflation, while if strings are formed after inflation we find
that the parameters of the inflationary model are similar to the ones obtained
recently.


title: A Survey of Unix Init Schemes

abstract:
  In most modern operating systems, init (as in "initialization") is the
program launched by the kernel at boot time. It runs as a daemon and typically
has PID 1. Init is responsible for spawning all other processes and scavenging
zombies. It is also responsible for reboot and shutdown operations. This
document describes existing solutions that implement the init process and/or
init scripts in Unix-like systems. These solutions range from the legacy and
still-in-use BSD and SystemV schemes, to recent and promising schemes from
Ubuntu, Apple, Sun and independent developers. Our goal is to highlight their
focus and compare their sets of features.


title:
Black holes thermodynamics to all orders in the Planck length in extra
  dimensions

abstract:
  We investigate the effects to all orders in the Planck length, from a
generalized uncertainty principle, on the thermodynamic parameters of radiating
Schwarzschild black holes in a scenario with large extra dimesions. We show
that black holes in this framework are hotter, decay faster and are less
classical objects. Particularly, we show that the final stage of the radiation
process is a black hole remnant with zero entropy, zero heat capacity and non
zero finite temperature. We finally compare our results with the ones obtained
in the standard Hawking picture and with the generalized uncertainty principle
to leading order in the Planck length.


title: Absorption Lengths in the Holographic Plasma

abstract:
  We consider the effect of a periodic perturbation with frequency $\omega$ on
the holographic N=4 plasma represented by the planar AdS black hole. The
response of the system is given by exponentially decaying waves. The
corresponding complex wave numbers can be found by solving wave equations in
the AdS black hole background with infalling boundary conditions on the horizon
in an analogous way as in the calculation of quasinormal modes. The complex
momentum eigenvalues have an interpretation as poles of the retarded Green's
functions, where the inverse of the imaginary part gives an absorption length
$\lambda$. At zero frequency we obtain the screening length for a static field.
These are directly related to the glueball masses in the dimensionally reduced
theory. We also point out that the longest screening length corresponds to an
operator with non-vanishing R-charge and thus does not have an interpretation
as a QCD3 glueball.


title:
From Feynman Proof of Maxwell Equations to Noncommutative Quantum
  Mechanics

abstract:
  In 1990, Dyson published a proof due to Feynman of the Maxwell equations
assuming only the commutation relations between position and velocity. With
this minimal assumption, Feynman never supposed the existence of Hamiltonian or
Lagrangian formalism. In the present communication, we review the study of a
relativistic particle using ``Feynman brackets.'' We show that Poincar\'e's
magnetic angular momentum and Dirac magnetic monopole are the consequences of
the structure of the Lorentz Lie algebra defined by the Feynman's brackets.
Then, we extend these ideas to the dual momentum space by considering
noncommutative quantum mechanics. In this context, we show that the
noncommutativity of the coordinates is responsible for a new effect called the
spin Hall effect. We also show its relation with the Berry phase notion. As a
practical application, we found an unusual spin-orbit contribution of a
nonrelativistic particle that could be experimentally tested. Another practical
application is the Berry phase effect on the propagation of light in
inhomogeneous media.


title: Film transitions of receding contact lines

abstract:
  When a solid plate is withdrawn from a liquid bath, a receding contact line
is formed where solid, liquid, and gas meet. Above a critical speed $U_{cr}$, a
stationary contact line can no longer exist and the solid will eventually be
covered completely by a liquid film. Here we show that the bifurcation diagram
of this coating transition changes qualitatively, from discontinuous to
continuous, when decreasing the inclination angle of the plate. We show that
this effect is governed by the presence of capillary waves, illustrating that
the large scale flow strongly effects the maximum speed of dewetting.


title: Implications of right-handed neutrinos with electroweak-scale masses

abstract:
  The possibility of constructing a model in which right-handed neutrinos have
electroweak-scale masses as well as being {\em non-sterile} was espoused in
Ref. 1. In this talk, I will review the ideas and results of Ref. 1 and discuss
its implications for colliders such as the Tevatron, LHC and ILC.


title:
Detecting mode entanglement: The role of coherent states, superselection
  rules and particle statistics

abstract:
  We discuss the possibility of observing quantum nonlocality using the
so-called mode entanglement, analyzing the differences between different types
of particles in this context. We first discuss the role of coherent states in
such experiments, and we comment on the existence of coherent states in nature.
The discussion of coherent states naturally raises questions about the role of
particle statistics in this problem. Although the Pauli exclusion principle
precludes coherent states with a large number of fermionic particles, we find
that a large number of fermionic coherent states, each containing at most one
particle, can be used to achieve the same effect as a bosonic coherent state
for the purposes of this problem. The discussion of superselection rules arises
naturally in this context, because their applicability to a given situation
prohibits the use of coherent states. This limitation particularly affects the
scenario that we propose for detecting the mode entanglement of fermionic
particles.


title:
On certain bounds for first-crossing-time probabilities of a
  jump-diffusion process

abstract:
  We consider the first-crossing-time problem through a constant boundary for a
Wiener process perturbed by random jumps driven by a counting process. On the
base of a sample-path analysis of the jump-diffusion process we obtain explicit
lower bounds for the first-crossing-time density and for the
first-crossing-time distribution function. In the case of the distribution
function, the bound is improved by use of processes comparison based on the
usual stochastic order. The special case of constant jumps driven by a Poisson
process is thoroughly discussed.


title: Electronic properties of graphene with a topological defect

abstract:
  Various types of topological defects in graphene are considered in the
framework of the continuum model for long-wavelength electronic excitations,
which is based on the Dirac--Weyl equation. The condition for the electronic
wave function is specified, and we show that a topological defect can be
presented as a pseudomagnetic vortex at the apex of a graphitic nanocone; the
flux of the vortex is related to the deficit angle of the cone. The cases of
all possible types of pentagonal defects, as well as several types of
heptagonal defects (with the numbers of heptagons up to three, and six), are
analyzed. The density of states and the ground state charge are determined.

categories: cond-mat.str-el cond-mat.mtrl-sci hep-th math-ph math.MP


title: Controlled dynamics of qubits in the presence of decoherence

abstract:
  An exactly solvable model for the decoherence of one and two-qubit states
interacting with a spin-bath, in the presence of a time-dependent magnetic
field is studied. The magnetic field is static along $\hat{z}$ direction and
oscillatory in the transverse plane. The transition probability and Rabi
oscillations between the spin-states of a single qubit is shown to depend on
the size of bath, the distribution of qubit-bath couplings and the initial bath
polarization. In contrast to the fast Gaussian decay for short times, the
polarization of the qubit shows an oscillatory power-law decay for long times.
The loss of entanglement for the maximally entangled two-qubit states, can be
controlled by tuning the frequency of the rotating field. The decay rates of
entanglement and purity for all the Bell-states are same when the qubits are
non-interacting, and different when they are interacting.


title: Scaled entropy of filtrations of $\sigma$-fields

abstract:
  We study the notion of the scaled entropy of a filtration of $\sigma$-fields
(= decreasing sequence of $\sigma$-fields) introduced by the first author
({V4}). We suggest a method for computing this entropy for the sequence of
$\sigma$-fields of pasts of a Markov process determined by a random walk over
the trajectories of a Bernoulli action of a commutative or nilpotent countable
group (Theorems~5,~6). Since the scaled entropy is a metric invariant of the
filtration, it follows that the sequences of $\sigma$-fields of pasts of random
walks over the trajectories of Bernoulli actions of lattices (groups ${\Bbb
Z}^d$) are metrically nonisomorphic for different dimensions $d$, and for the
same $d$ but different values of the entropy of the Bernoulli scheme. We give a
brief survey of the metric theory of filtrations, in particular, formulate the
standardness criterion and describe its connections with the scaled entropy and
the notion of a tower of measures.


title: Molecular gas in nearby low-luminosity QSO host galaxies

abstract:
  This paper addresses the global molecular gas properties of a representative
sample of galaxies hosting low-luminosity quasistellar objects. An abundant
supply of gas is necessary to fuel both the active galactic nucleus and any
circum-nuclear starburst activity of QSOs.
  We selected a sample of nearby low-luminosity QSO host galaxies that is free
of infrared excess biases. All objects are drawn from the Hamburg-ESO survey
for bright UV-excess QSOs, have DEC>-30 degrees and redshifts that do not
exceed z=0.06. The IRAM 30m telescope was used to measure the CO(1-0) and
CO(2-1) transition in parallel.
  27 out of 39 galaxies in the sample have been detected. The molecular gas
masses of the detected sources range from 0.4E9 M_sun to 9.7E9 M_sun. We can
confirm that the majority of galaxies hosting low-luminosity QSOs are rich in
molecular gas. The properties of galaxies hosting brighter type I AGN and
circumnuclear starformation regions differ from the properties of galaxies with
fainter central regions. The overall supply of molecular gas and the spread of
the line width distribution is larger. When comparing the far-infrared with the
CO luminosities, the distribution can be separated into two different
power-laws: one describing the lower activity Seyfert I population and the
second describing the luminous QSO population. The separation in the
L_FIR/L'_CO behavior may be explainable with differing degrees of compactness
of the emission regions. We provide a simple model to describe the two
power-laws. The sample studied in this paper is located in a transition region
between the two populations.


title:
Dynamics and thermalization of the nuclear spin bath in the
  single-molecule magnet Mn12-ac: test for the theory of spin tunneling

abstract:
  The description of the tunneling of a macroscopic variable in the presence of
a bath of localized spins is a subject of great fundamental and practical
interest, and is relevant for many solid-state qubit designs. Instead of
focusing on the the "central spin" (as is most often done), here we present a
detailed study of the dynamics of the nuclear spin bath in the Mn12-ac
single-molecule magnet, probed by NMR experiments down to very low temperatures
(T = 20 mK). We find that the longitudinal relaxation rate of the 55Mn nuclei
in Mn12-ac becomes roughly T-independent below T = 0.8 K, and can be strongly
suppressed with a longitudinal magnetic field. This is consistent with the
nuclear relaxation being caused by quantum tunneling of the molecular spin, and
we attribute the tunneling fluctuations to the minority of fast-relaxing
molecules present in the sample. The transverse nuclear relaxation is also
T-independent for T < 0.8 K, and can be explained qualitatively and
quantitatively by the dipolar coupling between like nuclei in neighboring
molecules. We also show that the isotopic substitution of 1H by 2H leads to a
slower nuclear longitudinal relaxation, consistent with the decreased tunneling
probability of the molecular spin. Finally, we demonstrate that, even at the
lowest temperatures, the nuclear spins remain in thermal equilibrium with the
lattice phonons, and we investigate the timescale for their thermal
equilibration. After a review of the theory of macroscopic spin tunneling in
the presence of a spin bath, we argue that most of our experimental results are
consistent with that theory, but the thermalization of the nuclear spins is
not.


title: Spin current and rectification in Luttinger liquids

abstract:
  We demonstrate that spin current can be generated by an ac voltage in a
one-channel quantum wire with strong repulsive electron interactions in the
presence of a non-magnetic impurity and uniform static magnetic field. In a
certain range of voltages, the spin current can exhibit a power dependence on
the ac voltage bias with a negative exponent. The spin current expressed in
units of $\hbar/2$ per second can become much larger than the charge current in
units of the electron charge per second. The spin current generation requires
neither spin-polarized particle injection nor time-dependent magnetic fields.


title: Contact mechanics: relation between interfacial separation and load

abstract:
  I study the contact between a rigid solid with a randomly rough surface and
an elastic block with a flat surface. I derive a relation between the (average)
interfacial separation $u$ and the applied normal squeezing pressure $p$. I
show that for non-adhesive inte raction and small applied pressure, p is
proportional to exp (-u/u_0), in good agreement with recent experimental
observation.


title:
Electronic instabilities of a Hubbard model approached as a large array
  of coupled chains: competition between d-wave superconductivity and pseudogap
  phase

abstract:
  We study the electronic instabilities in a 2D Hubbard model where one of the
dimensions has a finite width, so that it can be considered as a large array of
coupled chains. The finite transverse size of the system gives rise to a
discrete string of Fermi points, with respective electron fields that, due to
their mutual interaction, acquire anomalous scaling dimensions depending on the
point of the string. Using bosonization methods, we show that the anomalous
scaling dimensions vanish when the number of coupled chains goes to infinity,
implying the Fermi liquid behavior of a 2D system in that limit. However, when
the Fermi level is at the Van Hove singularity arising from the saddle points
of the 2D dispersion, backscattering and Cooper-pair scattering lead to the
breakdown of the metallic behavior at low energies. These interactions are
taken into account through their renormalization group scaling, studying in
turn their influence on the nonperturbative bosonization of the model. We show
that, at a certain low-energy scale, the anomalous electron dimension diverges
at the Fermi points closer to the saddle points of the 2D dispersion. The
d-wave superconducting correlations become also large at low energies, but
their growth is cut off as the suppression of fermion excitations takes place
first, extending progressively along the Fermi points towards the diagonals of
the 2D Brillouin zone. We stress that this effect arises from the vanishing of
the charge stiffness at the Fermi points, characterizing a critical behavior
that is well captured within our nonperturbative approach.


title:
Self-consistent calculations within the Extended Theory of Finite Fermi
  Systems

abstract:
  The Extended Theory of Finite Fermi Systems(ETFFS) describes nuclear
excitations considering phonons and pairing degrees of freedom, using
experimental single particle energies and the effective Landau-Migdal
interaction. Here we use the Skyrme interactions in order to extend the range
of applicability of the ETFFS to experimentally not yet investigated
short-lived isotopes. We find that Skyrme interactions which reproduce at the
mean field level both ground state properties and nuclear excitations are able
to describe the spreading widths of the giant resonances in the new approach,
but produce shifts of the centroid energies. A renormalization of the Skyrme
interactions is required for approaches going beyond the mean field level.


title: Detecting entanglement of random states with an entanglement witness

abstract:
  The entanglement content of high-dimensional random pure states is almost
maximal, nevertheless, we show that, due to the complexity of such states, the
detection of their entanglement using witness operators is rather difficult. We
discuss the case of unknown random states, and the case of known random states
for which we can optimize the entanglement witness. Moreover, we show that
coarse graining, modeled by considering mixtures of m random states instead of
pure ones, leads to a decay in the entanglement detection probability
exponential with m. Our results also allow to explain the emergence of
classicality in coarse grained quantum chaotic dynamics.


title: Notes on a SQCD-like plasma dual and holographic renormalization

abstract:
  We study the thermodynamics and the jet quenching parameter of a black hole
solution dual to a SQCD-like plasma which includes the backreaction of
fundamental flavors. The free energy is calculated in several ways, including
some recently proposed holographic renormalization prescriptions. The validity
of the latter is confirmed by the consistency with the other methods. The
resulting thermodynamic properties are similar to the Little String Theory
ones: the temperature is fixed at the Hagedorn value and the free energy is
vanishing. Finally, an accurate analysis of the relevant string configurations
shows that the jet quenching parameter is zero in this model, in agreement with
previous findings.


title: Unruh's detector in the presence of Lorentz symmetry breaking

abstract:
  We investigate the quantum field theory of a Lorentz non-invariant model with
a massive nonlinear dispersion relation in Minkowski space. The model involves
some non-causal signals in the form of wave packets propagating with
super-luminal group velocities. To avoid the problems with causality we
characterize the causal sector of the theory by a cutoff condition excluding
all super-luminal group velocities. It is argued that in the causal theory
satisfying the energy positivity condition an Unruh's detector moving with a
constant velocity with respect to the preferred frame does not detect any
particle. But in a causal theory violating energy positivity, detection of a
field quanta occurs. We comment on the origin of this particle creation.


title:
Towards a Holistic View of the Heating and Cooling of the Intracluster
  Medium

abstract:
  (Abridged) X-ray clusters are conventionally divided into two classes: "cool
core" (CC) clusters and "non-cool core" (NCC) clusters. Yet relatively little
attention has been given to the origins of this dichotomy and, in particular,
to the energetics and thermal histories of the two classes. We develop a model
for the entropy profiles of clusters starting from the configuration
established by gravitational shock heating and radiative cooling. At large
radii, gravitational heating accounts for the observed profiles and their
scalings well. However, at small and intermediate radii, radiative cooling and
gravitational heating cannot be combined to explain the observed profiles of
either type of cluster. The inferred entropy profiles of NCC clusters require
that material is preheated prior to cluster collapse in order to explain the
absence of low entropy (cool) material in these systems. We show that a similar
modification is also required in CC clusters in order to match their properties
at intermediate radii. In CC clusters, this modification is unstable, and an
additional process is required to prevent cooling below a temperature of a few
keV. We show that this can be achieved by adding a self-consistent AGN feedback
loop in which the lowest-entropy, most rapidly cooling material is heated so
that it rises buoyantly to mix with material at larger radii. The resulting
model does not require fine tuning and is in excellent agreement with a wide
variety of observational data. Some of the other implications of this model are
briefly discussed.


title:
Spin gap and string order parameter in the ferromagnetic Spiral
  Staircase Heisenberg Ladder: a quantum Monte Carlo study

abstract:
  We consider a spin-1/2 ladder with a ferromagnetic rung coupling J_\perp and
inequivalent chains. This model is obtained by a twist (\theta) deformation of
the ladder and interpolates between the isotropic ladder (\theta=0) and the
SU(2) ferromagnetic Kondo necklace model (\theta=\pi). We show that the ground
state in the (\theta,J_\perp) plane has a finite string order parameter
characterising the Haldane phase. Twisting the chain introduces a new energy
scale, which we interpret in terms of a Suhl-Nakamura interaction. As a
consequence we observe a crossover in the scaling of the spin gap at weak
coupling from \Delta/J_\| \propto J_\perp/J_\| for \theta < \theta_c \simeq
8\pi/9 to \Delta/J_\| \propto (J_\perp/J_\|)^2 for \theta > \theta_c. Those
results are obtained on the basis of large scale Quantum Monte Carlo
calculations.


title:
Inter-individual variability in sensory weighting of a plantar
  pressure-based, tongue-placed tactile biofeedback for controlling posture

abstract:
  The purpose of the present experiment was to investigate whether the sensory
weighting of a plantar pressure-based, tongue-placed tactile biofeedback for
controlling posture could be subject to inter-individual variability. To
achieve this goal, 60 young healthy adults were asked to stand as immobile as
possible with their eyes closed in two conditions of No-biofeedback and
Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a
force platform. Overall, results showed reduced CoP displacements in the
Biofeedback relative to the No-biofeedback condition, evidencing the ability of
the central nervous system to efficiently integrate an artificial
plantar-based, tongue-placed tactile biofeedback for controlling posture during
quiet standing. Results further showed a significant positive correlation
between the CoP displacements measured in the No-biofeedback condition and the
decrease in the CoP displacements induced by the use of the biofeedback. In
other words, the degree of postural stabilization appeared to depend on each
subject's balance control capabilities, the biofeedback yielding a greater
stabilizing effect in subjects exhibiting the largest CoP displacements when
standing in the No-biofeedback condition. On the whole, by evidencing a
significant inter-individual variability in sensory weighting of an additional
tactile information related to foot sole pressure distribution for controlling
posture, the present findings underscore the need and the necessity to address
the issue of inter-individual variability in the field of neuroscience.


title: Status of art of reaction models for projectiles far from stability

abstract:
  This talk will review the status of art of nuclear and Coulomb breakup
theories and their relation to optical models of elastic scattering of exotic
projectiles. The effect of the final state interactions between the breakup
particle and the core and target nuclei will be clarified and some typical
numerical calculations for the relevant observables will be presented and
compared to experimental data. Finally new results will be shown to demonstrate
the feasibility of a novel type of experiment involving heavy projectiles far
from stability on heavy targets.


title: Embedding Theorems and Boundary-value Problems for cusp domains

abstract:
  We study the Robin boundary-value problem for bounded domains with isolated
singularities. Because for such domains trace spaces of space $H^1(D)$ on its
boundaries are weighted Sobolev spaces $L^{2, \xi}(\partial D)$ existence and
uniqueness of corresponding Robin boundary-value problems depends on properties
of embedding operators $I_1: H^{1}(D)\to L^{2}(D)$ and $I_{2}:H^{1}(D)\to
L^{2,\xi}(\partial D)$ i.e. on type of singularities. We obtain an exact
description of the weights $\xi$ for bounded domains with 'outside peaks' on
its boundaries. This result allows us to formulate correctly the corresponding
Robin boundary-value problems for elliptic operators.


title: Near-homeomorphisms of Nobeling manifolds

abstract:
  We characterize maps between $n$-dimensional N\"obeling manifolds that can be
approximated by homeomorphisms.


title: Tunneling into low-dimensional and strongly correlated conductors

abstract:
  A general nonperturbative theory of the low-energy electron propagator is
developed and used to calculate the single-particle density of states in a
variety of systems. This method involves the decoupling of the
electron-electron interaction through a Hubbard-Stratonovich transformation,
followed by a saddle-point approximation of the remaining functional integral.
The final expression is found to be the tunneling analog of the infrared
catastrophe that occurs in the x-ray edge problem; here, the host system
responds to the potential produced by the abrupt addition of an electron during
a tunneling event. This response can lead to a suppression in the tunneling
density of states near the Fermi energy. This method is adaptable to lattice or
continuum models of any dimensionality, with or without translational
invariance. When applied, the exact density of states is obtained for the
Tomonaga-Luttinger model, and the pseudogap of a fractional quantum Hall fluid
is recovered.


title: Spin alignment of dark matter haloes in the shells of the largest voids

abstract:
  Using the high resolution cosmological N-body simulation MareNostrum Universe
we study the orientation of shape and angular momentum of galaxy-size dark
matter haloes around large voids. We find that haloes located on the shells of
the largest cosmic voids have angular momenta that tend to be preferentially
perpendicular to the direction that joins the centre of the halo and the centre
of the void. This alignment has been found in spiral galaxies around voids
using galaxy redshift surveys. We measure for the first time the strength of
this alignment, showing how it falls off with increasing distance to the centre
of the void. We also confirm the correlation between the intensity of this
alignment and the halo mass. The analysis of the orientation of the halo main
axes confirms the results of previous works. Moreover, we find a similar
alignment for the baryonic matter inside dark matter haloes, which is much
stronger in their inner parts.


title:
Tunneling spectroscopy of persistent currents in superconducting
  microrings

abstract:
  It is shown that in a structure consisting of a superconducting ring-shaped
electrode overlapped by a normal metal contact through a thin oxide barrier,
measurements of the tunnel current in magnetic field can probe persistent
currents in the ring. The effect manifests itself as periodic oscillations of
the tunnel current through the junction at a fixed bias voltage as function of
perpendicular magnetic field. The magnitude of oscillations depends on bias
point. It reaches maximum at energy eV which is close to the superconducting
gap and decreases with increase of temperature. The period of oscillations dF
in units of magnetic flux is equal neither to h/e nor to h/2e, but
significantly exceeds these values for larger loop circumferences. The
phenomenon is explained by formation of metastable states with large vorticity.
The pairing potential and the superconducting density of states are
periodically modulated by the persistent currents at sub-critical values
resulting in corresponding variations of the measured tunnel current.


title: The Ricci iteration and its applications

abstract:
  In this Note we introduce and study dynamical systems related to the Ricci
operator on the space of Kahler metrics as discretizations of certain geometric
flows. We pose a conjecture on their convergence towards canonical Kahler
metrics and study the case where the first Chern class is negative, zero or
positive. This construction has several applications in Kahler geometry, among
them an answer to a question of Nadel and a construction of multiplier ideal
sheaves.


title: Chains in the noncrossing partition lattice

abstract:
  We establish recursions counting various classes of chains in the noncrossing
partition lattice of a finite Coxeter group. The recursions specialize a
general relation which is proven uniformly (i.e. without appealing to the
classification of finite Coxeter groups) using basic facts about noncrossing
partitions. We solve these recursions for each finite Coxeter group in the
classification. Among other results, we obtain a simpler proof of a known
uniform formula for the number of maximal chains of noncrossing partitions and
a new uniform formula for the number of edges in the noncrossing partition
lattice. All of our results extend to the m-divisible noncrossing partition
lattice.


title:
Resistive state of quasi-one-dimensional superconductors: fluctuations
  vs. sample inhomogeneity

abstract:
  The shape of experimentally observed R(T) transition of thin superconducting
wires is analyzed. Broadening of the transition in quasi-1-dimensional
superconducting channels is typically associated with phase slip mechanism
provided by thermal or quantum fluctuations. It is shown that consideration of
inevitable geometrical inhomogeneity and finite dimensions of real samples
studied in experiments is of primary importance for interpretation of results.
The analysis is based on experimental fact that for many superconducting
materials the critical temperature is a function of characteristic dimension of
a low-dimensional system: film thickness or wire cross section


title:
The chemical abundance of the very metal rich old Open Clusters NGC 6253
  and NGC 6791

abstract:
  In the framework of a project aiming at deriving in a homogeneous way the
properties (age, distance, reddening and detailed chemical abundances) of a
large sample of old open clusters, we present here the metal abundance and the
abundance ratios of light (C, N, O, Na, Mg, Al, Si, Ca, Ti) and heavier (Cr,
Mn, Ni, Ba, Eu) elements in the galactic open clusters NGC 6253 and NGC 6791.
We performed spectrum synthesis of selected lines on high resolution spectra of
four red clump stars in NGC 6253, taken with the UVES and FEROS spectrographs.
We also determined abundances of the same elements for four red clump stars in
NGC 6791, observed with SARG, for which we had derived the atmospheric
parameters and the iron, carbon and oxygen abundances in a previous paper
(Gratton et al. 2006). The average metallicity of NGC 6253 is [Fe/H]=+0.46 (rms
= 0.03 dex, systematic error = 0.08 dex), obtained by extensive spectral
synthesis of Fe lines. This intermediate age cluster closely resembles the old
open cluster NGC 6791, as far as the chemical composition is concerned. C, N, O
do not show any significant abundance scatter; they are underabundant with
respect to the solar values both in NGC 6253 and NGC 6791. We also find no
evident star-to-star scatter in any of the elements measured in both clusters,
with the possible exception of Na in NGC 6791. The two clusters show very
similar abundances, except for Mg, overabundant in NGC 6791 and not in NGC
6253. Both have solar scaled alpha-elements abundances. We have compared our
abundance ratios with literature values for disk giants and dwarfs and bulge
giants, finding a general good agreement with the run of elemental ratios with
[Fe/H] of disk objects.


title: Degenerate Bose-Bose mixture in a three-dimensional optical lattice

abstract:
  We produce a heteronuclear quantum degenerate mixture of two bosonic species,
$^{87}$Rb and $^{41}$K, in a three-dimensional optical lattice. On raising the
lattice barriers, we observe the disapperance of the inference pattern of the
heavier $^{87}$Rb, shifting toward shallower lattice depths in the presence of
a minor fraction of $^{41}$K. This effect is sizable and requires only a
marginal overlap between the two species. We compare our results with similar
findings reported for Fermi-Bose mixtures and discuss the interpretation
scenarios proposed to date, arguing that the explanation may be linked to the
increased effective mass due to the interspecies interactions.


title:
Extremal subsets of {1,...,n} avoiding solutions to linear equations in
  three variables

abstract:
  We refine previous results to provide examples, and in some cases precise
classifications, of extremal subsets of {1,...,n} containing no solutions to a
wide class of non-invariant, homogeneous linear equations in three variables,
i.e.: equations of the form ax+by=cz with a+b \neq c.


title: Intracluster Short Gamma-Ray Bursts by Compact Binary Mergers

abstract:
  One of the possible origins of short gamma-ray bursts (SGRBs) is merging of
compact binaries, and the effect of large kick velocity is a signature that can
be used as an observational test for this hypothesis. Intracluster SGRBs that
escaped from a host galaxy in a galaxy cluster are interesting in this context,
since they would escape more easily by cluster tidal force, and would have
brighter afterglow luminosity by dense intracluster gas, than those in general
field galaxies. Here we calculate the escape fraction of compact binaries from
their host galaxies in a galaxy cluster, and discuss some observational
implications. We found that the escape fraction strongly depends on the nature
of dark matter subhalos associated with member galaxies. If the amount of dark
matter around member galaxies is not large and the gravitational potential for
an escaping binary is determined mostly by stellar mass, most of SGRBs should
escape and be observed as hostless, which is a much higher fraction than those
in the field. Hence, statistics of intracluster SGRBs could give important
information about the dark matter distribution in galaxy clusters, as well as
hints for the origin of SGRBs.


title:
BeppoSAX observation of 4U 1705-44: detection of hard X-ray emission in
  the soft state

abstract:
  4U 1705-44 is one of the best studied type I X-ray burster and atoll sources.
Since it covers a wide range in luminosity (from a few to 50 x 10^{36} erg
s^{-1}) and shows clear spectral state transitions, it represents a good
laboratory to test the accretion models proposed for atoll sources. We analysed
the energy spectrum accumulated with BeppoSAX observations (43.5 ksec) in
August 2000 when the source was in a soft spectral state. The continuum of the
wide band energy spectrum is well described by the sum of a blackbody
(kT_{bb}~0.56 keV) and a Comptonized component (seed-photon temperature kT_W~1
keV, electron temperature kT_e~2.7 keV, and optical depth ~11). A hard tail was
detected at energies above ~25 keV. The latter can be modeled by a power law
having a photon index ~2.9 which contributes ~11% of the total flux in the
range 0.1-200 keV. A broad emission line, possibly from a relativistic
accretion disk, models the feature in the Fe K line region of the spectrum.
This is the first time that a high energy tail has been observed during a soft
state of the source.


title: Metastable supergravity vacua with F and D supersymmetry breaking

abstract:
  We study the conditions under which a generic supergravity model involving
chiral and vector multiplets can admit viable metastable vacua with
spontaneously broken supersymmetry and realistic cosmological constant. To do
so, we impose that on the vacuum the scalar potential and all its first
derivatives vanish, and derive a necessary condition for the matrix of its
second derivatives to be positive definite. We study then the constraints set
by the combination of the flatness condition needed for the tuning of the
cosmological constant and the stability condition that is necessary to avoid
unstable modes. We find that the existence of such a viable vacuum implies a
condition involving the curvature tensor for the scalar geometry and the charge
and mass matrices for the vector fields. Moreover, for given curvature, charges
and masses satisfying this constraint, the vector of F and D auxiliary fields
defining the Goldstino direction is constrained to lie within a certain domain.
The effect of vector multiplets relative to chiral multiplets is maximal when
the masses of the vector fields are comparable to the gravitino mass. When the
masses are instead much larger or much smaller than the gravitino mass, the
effect becomes small and translates into a correction to the effective
curvature. We finally apply our results to some simple classes of examples, to
illustrate their relevance.


title: Measurements of the CKM angle phi_3/gamma

abstract:
  We present a review on the measurements of the CKM angle gamma (phi_3) as
performed by the BABAR and Belle experiments at the asymmetric-energy e+e- B
factories colliders PEP-II and KEKB.


title:
Higher Dimensional Multiparameter Unitary and Nonunitary Braid Matrices:
  Even Dimensions

abstract:
  A class of $(2n)^2\times(2n)^2$ multiparameter braid matrices are presented
for all $n$ $(n\geq 1)$. Apart from the spectral parameter $\theta$, they
depend on $2n^2$ free parameters $m_{ij}^{(\pm)}$, $i,j=1,...,n$. For real
parameters the matrices $R(\theta)$ are nonunitary. For purely imaginary
parameters they became unitary. Thus a unification is achieved with odd
dimensional multiparameter solutions presented before.


title: A Cosmic Watershed: the WVF Void Detection Technique

abstract:
  On megaparsec scales the Universe is permeated by an intricate filigree of
clusters, filaments, sheets and voids, the Cosmic Web. For the understanding of
its dynamical and hierarchical history it is crucial to identify objectively
its complex morphological components. One of the most characteristic aspects is
that of the dominant underdense Voids, the product of a hierarchical process
driven by the collapse of minor voids in addition to the merging of large ones.
In this study we present an objective void finder technique which involves a
minimum of assumptions about the scale, structure and shape of voids. Our void
finding method, the Watershed Void Finder (WVF), is based upon the Watershed
Transform, a well-known technique for the segmentation of images. Importantly,
the technique has the potential to trace the existing manifestations of a void
hierarchy. The basic watershed transform is augmented by a variety of
correction procedures to remove spurious structure resulting from sampling
noise. This study contains a detailed description of the WVF. We demonstrate
how it is able to trace and identify, relatively parameter free, voids and
their surrounding (filamentary and planar) boundaries. We test the technique on
a set of Kinematic Voronoi models, heuristic spatial models for a cellular
distribution of matter. Comparison of the WVF segmentations of low noise and
high noise Voronoi models with the quantitatively known spatial characteristics
of the intrinsic Voronoi tessellation shows that the size and shape of the
voids are succesfully retrieved. WVF manages to even reproduce the full void
size distribution function.


title:
Singular lagrangian systems and variational constrained mechanics on Lie
  algebroids

abstract:
  The purpose of this paper is describe Lagrangian Mechanics for constrained
systems on Lie algebroids, a natural framework which covers a wide range of
situations (systems on Lie groups, quotients by the action of a Lie group,
standard tangent bundles...). In particular, we are interested in two cases:
singular Lagrangian systems and vakonomic mechanics (variational constrained
mechanics). Several examples illustrate the interest of these developments.


title: Filling inequalities do not depend on topology

abstract:
  Gromov's universal filling inequalities relate the filling radius and the
filling volume of a Riemannian manifold to its volume. The main result of the
present article is that in dimensions at least three the optimal constants in
the filling inequalities depend only on dimension and orientability, not on the
manifold itself. This contrasts with the analogous situation for the optimal
systolic inequality, which does depend on the manifold.


title: Composition of quantum states and dynamical subadditivity

abstract:
  We introduce a composition of quantum states of a bipartite system which is
based on the reshuffling of density matrices. This non-Abelian product is
associative and stems from the composition of quantum maps acting on a simple
quantum system. It induces a semi-group in the subset of states with maximally
mixed partial traces. Subadditivity of the von Neumann entropy with respect to
this product is proved. It is equivalent to subadditivity of the entropy of
bistochastic maps with respect to their composition, where the entropy of a map
is the entropy of the corresponding state under the Jamiolkowski isomorphism.
Strong dynamical subadditivity of a concatenation of three bistochastic maps is
established. Analogous bounds for the entropy of a composition are derived for
general stochastic maps. In the classical case they lead to new bounds for the
entropy of a product of two stochastic matrices.


title:
Practical quantum key distribution over 60 hours at an optical fiber
  distance of 20km using weak and vacuum decoy pulses for enhanced security

abstract:
  Experimental one-way decoy pulse quantum key distribution running
continuously for 60 hours is demonstrated over a fiber distance of 20km. We
employ a decoy protocol which involves one weak decoy pulse and a vacuum pulse.
The obtained secret key rate is on average over 10kbps. This is the highest
rate reported using this decoy protocol over this fiber distance and duration.


title: Local Approximations for Effective Scalar Field Equations of Motion

abstract:
  Fluctuation and dissipation dynamics is examined at all temperature ranges
for the general case of a background time evolving scalar field coupled to
heavy intermediate quantum fields which in turn are coupled to light quantum
fields. The evolution of the background field induces particle production from
the light fields through the action of the intermediate catalyzing heavy
fields. Such field configurations are generically present in most particle
physics models, including Grand Unified and Supersymmetry theories, with
application of this mechanism possible in inflation, heavy ion collision and
phase transition dynamics. The effective evolution equation for the background
field is obtained and a fluctuation-dissipation theorem is derived for this
system. The effective evolution in general is nonlocal in time. Appropriate
conditions are found for when these time nonlocal effects can be approximated
by local terms. Here careful distinction is made between a local expansion and
the special case of a derivative expansion to all orders, which requires
analytic behavior of the evolution equation in Fourier space.


title: Synthesis and magnetic properties of NiFe_{2-x}Al_{x}O_{4} nanoparticles

abstract:
  Nanocrystalline Al-doped nickel ferrite powders have been synthesized by
sol-gel auto-ignition method and the effect of non-magnetic aluminum content on
the structural and magnetic properties has been studied. The X-ray diffraction
(XRD) revealed that the powders obtained are single phase with inverse spinel
structure. The calculated grain sizes from XRD data have been verified using
transmission electron microscopy (TEM). TEM photographs show that the powders
consist of nanometer-sized grains. It was observed that the characteristic
grain size decreases from 29 to 6 nm as the non-magnetic Al content increases,
which was attributed to the influence of non-magnetic Al concentration on the
grain size. Magnetic hysteresis loops were measured at room temperature with a
maximum applied magnetic field of 1T. As aluminum content increases, the
measured magnetic hysteresis curves become more and more narrow and the
saturation magnetization and remanent magnetization both decreased. The
reduction of agnetization compared to bulk is a consequence of spin
non-collinearity. Further reduction of magnetization with increase of aluminum
content is caused by non-magnetic Al^{3+} ions and weakened interaction between
sublattices. This, as well as the decrease in hysteresis was understood in
terms of the decrease in particle size.


title:
Dirty-paper Coding without Channel Information at the Transmitter and
  Imperfect Estimation at the Receiver

abstract:
  In this paper, we examine the effects of imperfect channel estimation at the
receiver and no channel knowledge at the transmitter on the capacity of the
fading Costa's channel with channel state information non-causally known at the
transmitter. We derive the optimal Dirty-paper coding (DPC) scheme and its
corresponding achievable rates with the assumption of Gaussian inputs. Our
results, for uncorrelated Rayleigh fading, provide intuitive insights on the
impact of the channel estimate and the channel characteristics (e.g. SNR,
fading process, channel training) on the achievable rates. These are useful in
practical scenarios of multiuser wireless communications (e.g. Broadcast
Channels) and information embedding applications (e.g. robust watermarking). We
also studied optimal training design adapted to each application. We provide
numerical results for a single-user fading Costa's channel with
maximum-likehood (ML) channel estimation. These illustrate an interesting
practical trade-off between the amount of training and its impact to the
interference cancellation performance using DPC scheme.


title:
Single Target-Spin Asymmetry in Semi-Inclusive Deep Inelastic Scattering
  on Transversely Polarized Nucleon Target

abstract:
  We use a new set of Collins functions to update a previous prediction on the
azimuthal asymmetries of pion productions in semi-inclusive deep inelastic
scattering (SIDIS) process on a transversely polarized nucleon target. We find
that the calculated results can give a good explanation to the HERMES
experiment with the new parametrization, and this can enrich our knowledge of
the fragmentation process. Furthermore, with two different approaches of
distribution and fragmentation functions, we present a prediction on the
azimuthal asymmetries of pion and kaon productions at the kinematics region of
the experiments E06010 and E06011 planned at Jefferson Lab (JLab). It is shown
that the results are insensitive to the models for the pion case. However, the
results for kaon production are sensitive to different approaches of
distribution and fragmentation functions. This is helpful to clarify some
points in the study of the azimuthal spin asymmetries and fragmentation
functions in hadronization processes.


title: Extraction d'entit\'es dans des collections \'evolutives

abstract:
  The goal of our work is to use a set of reports and extract named entities,
in our case the names of Industrial or Academic partners. Starting with an
initial list of entities, we use a first set of documents to identify syntactic
patterns that are then validated in a supervised learning phase on a set of
annotated documents. The complete collection is then explored. This approach is
similar to the ones used in data extraction from semi-structured documents
(wrappers) and do not need any linguistic resources neither a large set for
training. As our collection of documents would evolve over years, we hope that
the performance of the extraction would improve with the increased size of the
training set.


title: Rate effects on layering of a confined linear alkane

abstract:
  We perform drainage experiments of a linear alkane fluid (n-hexadecane) down
to molecular thicknesses, and focus on the role played by the confinement rate.
We show that molecular layering is strongly influenced by the velocity at which
the confining walls are approached: under high enough shear rates, the confined
medium behaves as a structureless liquid of enhanced viscosity for film
thickness below $\sim$10 nm. Our results also lead us to conclude that a
rapidly confined film can be quenched in a metastable disordered state, which
might be related with recent intriguing results on the shear properties of
confined films produced at different rates [Zhu and Granick, Phys. Rev. Lett.
{\bf 93}, 096101 (2004)].


title: Gaussian localizable entanglement

abstract:
  We investigate localization of entanglement of multimode Gaussian states into
a pair of modes by local Gaussian measurements on the remaining modes and
classical communication. We find that for pure states and for mixed symmetric
states maximum entanglement between two modes can be localized by local
homodyne detections, i.e. projections onto infinitely squeezed states. We also
show that non-Gaussian measurements allow to localize more entanglement than
Gaussian ones.


title:
Anisotropic small-scale constraints on energy in rotating stratified
  turbulence

abstract:
  Rapidly rotating, stably stratified three-dimensional inviscid flows conserve
both energy and potential enstrophy. We show that in such flows, the forward
cascade of potential enstrophy imposes anisotropic constraints on the
wavenumber distribution of kinetic and potential energy. The horizontal kinetic
energy is suppressed in the large, nearly horizontal wave modes, and should
decay with the horizontal wavenumber as $k_h^{-3}$. The potential energy is
suppressed in the large, nearly vertical wave modes, and should decay with the
vertical wavenumber as $k_z^{-3}$. These results augment the only other exact
prediction for the scaling of energy spectra due to constraints by potential
enstrophy obtained by Charney (J. Atmos. Sci. 28, 1087 (1971)), who showed that
in the quasi-geostrophic approximation for rotating stratified flows, the
energy spectra must scale isotropically with total wavenumber as $k^{-3}$. We
test our predicted scaling estimates using resolved numerical simulations of
the Boussinesq equations in the relevant parameter regimes, and find reasonable
agreement.


title:
Evidence for Growth of Eccentricity and Mass Clearing in a Disc Interior
  to a Planet

abstract:
  We present computational results showing eccentricity growth in the inner
portions of a protoplanetary disc. We attribute this to the evolving surface
density of the disc. The planet creates a gap, which adjusts the balance
between the 3:1 (eccentricity exciting) and 2:1 (eccentricity damping)
resonances. The eccentricity of the inner disc can rise as high as 0.3, which
is sufficient to cause it to be accreted onto the star. This offers an
alternative mechanism for producing the large holes observed in the discs of
CoKu Tau/4, GM Aur and DM Tau.


title: Simple pairs potential-density for flat rings

abstract:
  Pairs potential-density in terms of elementary functions that represents flat
rings structures are presented. We study structures representing one or several
concentric flat rings. Also disks surrounded by concentric flat rings are
exhibited. The stability of concentrically circular orbits of particles moving
on a flat ring structure is analyzed for radial perturbations.


title: Bound states in N = 4 SYM on T^3: Spin(2n) and the exceptional groups

abstract:
  The low energy spectrum of (3+1)-dimensional N=4 supersymmetric Yang-Mills
theory on a spatial three-torus contains a certain number of bound states,
characterized by their discrete abelian magnetic and electric 't Hooft fluxes.
At weak coupling, the wave-functions of these states are supported near points
in the moduli space of flat connections where the unbroken gauge group is
semi-simple. The number of such states is related to the number of normalizable
bound states at threshold in the supersymmetric matrix quantum mechanics with
16 supercharges based on this unbroken group. Mathematically, the determination
of the spectrum relies on the classification of almost commuting triples with
semi-simple centralizers. We complete the work begun in a previous paper, by
computing the spectrum of bound states in theories based on the
even-dimensional spin groups and the exceptional groups. The results satisfy
the constraints of S-duality in a rather non-trivial way.


title: Hot Topics from CLEO-c

abstract: I briefly review some of the results obtained using the CLEO-c detector


title: Semileptonic bc to cc Baryon Decay and Heavy Quark Spin Symmetry

abstract:
  We study the semileptonic decays of the lowest-lying bc baryons to the
lowest-lying cc baryons (Xi_{bc}^{(\prime*)}--> Xi_{cc}^{(*)} and
Omega_{bc}^{(\prime*)}--> Omega_{cc}^{(*)}), in the limit m_b, m_c >>
Lambda_{QCD} and close to the zero recoil point. The separate heavy quark spin
symmetries make it possible to describe all these decays using a single form
factor. We recover results derived previously by White and Savage in a manner
which we think is more straightforward and parallels the method applied later
to study Bc semileptonic decays. We further discuss the resemblance between the
bc baryon decays and those of Bc mesons to eta_c and J/\psi mesons and comment
on the relation between the slopes of the single functions describing each set
of decays. Our results can straightforwardly be applied to the decays of bb
baryons to bc baryons.


title: A Characterization of the Morse Minimal Set up to Topological Conjugacy

abstract:
  We establish necessary and sufficient conditions for a dynamical system to be
topologically conjugate to the Morse minimal set, the shift orbit closure of
the Morse sequence, and conditions for topological conjugacy to the closely
related Teoplitz minimal set.


title:
On the constant in the Mertens product for arithmetic progressions. I.
  Identities

abstract:
  The aim of the paper is the proof of new identities for the constant in the
Mertens product for arithmetic progressions. We deal with the problem of the
numerical computation of these constants in another paper.


title:
Asymptotics of the allele frequency spectrum associated with the
  Bolthausen-Sznitman coalescent

abstract:
  We work in the context of the infinitely many alleles model. The allelic
partition associated with a coalescent process started from n individuals is
obtained by placing mutations along the skeleton of the coalescent tree; for
each individual, we trace back to the most recent mutation affecting it and
group together individuals whose most recent mutations are the same. The number
of blocks of each of the different possible sizes in this partition is the
allele frequency spectrum. The celebrated Ewens sampling formula gives precise
probabilities for the allele frequency spectrum associated with Kingman's
coalescent. This (and the degenerate star-shaped coalescent) are the only
Lambda coalescents for which explicit probabilities are known, although they
are known to satisfy a recursion due to Moehle. Recently, Berestycki,
Berestycki and Schweinsberg have proved asymptotic results for the allele
frequency spectra of the Beta(2-alpha,alpha) coalescents with alpha in (1,2).
In this paper, we prove full asymptotics for the case of the
Bolthausen-Sznitman coalescent.


title:
On the Outage Capacity of a Practical Decoder Using Channel Estimation
  Accuracy

abstract:
  The optimal decoder achieving the outage capacity under imperfect channel
estimation is investigated. First, by searching into the family of nearest
neighbor decoders, which can be easily implemented on most practical coded
modulation systems, we derive a decoding metric that minimizes the average of
the transmission error probability over all channel estimation errors. This
metric, for arbitrary memoryless channels, achieves the capacity of a composite
(more noisy) channel. Next, according to the notion of estimation-induced
outage capacity (EIO capacity) introduced in our previous work, we characterize
maximal achievable information rates associated to the proposed decoder. The
performance of the proposed decoding metric over uncorrelated Rayleigh fading
MIMO channels is compared to both the classical mismatched maximum-likelihood
(ML) decoder and the theoretical limits given by the EIO capacity (i.e. the
best decoder in presence of channel estimation errors). Numerical results show
that the derived metric provides significant gains, in terms of achievable
information rates and bit error rate (BER), in a bit interleaved coded
modulation (BICM) framework, without introducing any additional decoding
complexity.


title: Quarkonium production in coherent pp/AA collisions and small-x physics

abstract:
  In this contribution we study the photoproduction of quarkonium in coherent
proton-proton and nucleus-nucleus interactions at the LHC. The integrated cross
sections and rapidity distributions are estimated using the Color Glass
Condensate (CGC) formalism, which takes into account the parton saturation
effects at high energies. Nuclear shadowing effects are also taken into
account.


title: Lindemann Criterion and the Anomalous Melting Curve of Sodium

abstract:
  Recent reports of the melting curve of sodium at high pressure have shown
that it has a very steep descent after a maximum of around 1000K at 31 GPa.
This is not due to a phase transition. According to the Lindemann criterion,
this behaviour should be apparent in the evolution of the Debye temperature
with pressure. In this work, we have performed an "ab-initio" analysis of the
behaviour of both the Debye temperature and the elastic constants up to 102
GPa, and find a clear trend at high pressure that should cause a noticeable
effect on the melting curve.


title:
Ultra High Energy Cosmic ray and gamma-ray signatures of inductive
  acceleration in AGN jets

abstract:
  The highest energy cosmic rays could be produced by drifts in magnetized,
cylindrically collimated, sheared jets of powerful active galaxies (i.e. FR II
radiogalaxies; radio loud quasars and high power BL Lacs). We show that in such
scenarios proton synchrotron radiation can give rise to detectable photon
fluxes at energies ranging from hundreds of keV to tens of MeV.


title:
Measurement of the Total Hadronic Cross Section in e+e- Annihilations
  below 10.56 GeV

abstract:
  Using the CLEO III detector, we measure absolute cross sections for e+e- -->
hadrons at seven center-of-mass energies between 6.964 and 10.538 GeV. The
values of R, the ratio of hadronic and muon pair production cross sections, are
determined within 2% total r.m.s. uncertainty.


title: On the tautological ring of a Jacobian modulo rational equivalence

abstract:
  We consider the Chow ring with rational coefficients of the Jacobian of a
curve. Assume D is a divisor in a base point free g^r_d of the curve such that
the canonical divisor K is a multiple of the divisor D. We find relations
between tautological cycles. We give applications for curves having a degree d
covering of P^1 whose ramification points are all of order d, and then for
hyperelliptic curves.


title: On Hyperon Decays Involving Two Charged Leptons

abstract:
  The hyperon decays with 2 negative charged leptons in the final states can be
of interest as possible tests for the Majorana netrinos. The study of these
decays are complementary to the double beta decays of heavy nuclei.


title: Ehlers symmetry at the next derivative order

abstract:
  We analyse four-dimensional gravity in the presence of general curvature
squared corrections and show that Ehlers' SL(2,R) symmetry, which appears in
the reduction of standard gravity to three dimensions, is preserved by the
correction terms. The mechanism allowing this is a correction of the SL(2,R)
transformation laws which resolves problems with the different scaling
behaviour of various terms occurring in the reduction.


title: The angel wins

abstract:
  The angel-devil game is played on an infinite two-dimensional ``chessboard''.
The squares of the board are all white at the beginning. The players called
angel and devil take turns in their steps. When it is the devil's turn, he can
turn a square black. The angel always stays on a white square, and when it is
her turn she can fly at a distance of at most J steps (each of which can be
horizontal, vertical or diagonal) to a new white square. Here J is a constant.
The devil wins if the angel does not find any more white squares to land on.
The result of the paper is that if J is sufficiently large then the angel has a
strategy such that the devil will never capture her. This deceptively
easy-sounding result has been a conjecture, surprisingly, for about thirty
years. Several other independent solutions have appeared simultaneously, some
of them prove that J=2 is sufficient (see the Wikipedia on the angel problem).
Still, it is hoped that the hierarchical solution presented here may prove
useful for some generalizations.


title: Protein mechanical unfolding: a model with binary variables

abstract:
  A simple lattice model, recently introduced as a generalization of the
Wako--Sait\^o model of protein folding, is used to investigate the properties
of widely studied molecules under external forces. The equilibrium properties
of the model proteins, together with their energy landscape, are studied on the
basis of the exact solution of the model. Afterwards, the kinetic response of
the molecules to a force is considered, discussing both force clamp and dynamic
loading protocols and showing that theoretical expectations are verified. The
kinetic parameters characterizing the protein unfolding are evaluated by using
computer simulations and agree nicely with experimental results, when these are
available. Finally, the extended Jarzynski equality is exploited to investigate
the possibility of reconstructing the free energy landscape of proteins with
pulling experiments.


title:
Approximate calculation of operator semigroups by perturbation of
  generators

abstract:
  Let $\Omega$ be an operator semigroup with generator $A$ in a sequentially
complete locally convex topological vector space $E$. For a semigroup with
generator $A+D$, where $D$ is a bounded linear operator on $E$, two integral
equations are derived. A theorem on continuous dependence of a semigroup on its
generator is proved. An application to random walk on $\mathbb{Z}$ is given.


title: The wall shear rate distribution for flow in random sphere packings

abstract:
  The wall shear rate distribution P(gamma) is investigated for pressure-driven
Stokes flow through random arrangements of spheres at packing fractions 0.1 <=
phi <= 0.64. For dense packings, P(gamma) is monotonic and approximately
exponential. As phi --> 0.1, P(gamma) picks up additional structure which
corresponds to the flow around isolated spheres, for which an exact result can
be obtained. A simple expression for the mean wall shear rate is presented,
based on a force-balance argument.


title:
Black Hole Entropy Constraints on Variation of the Gravitational
  Constant

abstract:
  Here we apply the Generalized Second Law of Thermodynamics (GSL) to black
holes accreting and emitting in the present Universe and derive upper limits on
the variation in the gravitational constant G. The limits depend on how the
gravitational mass M varies with G. Parameterizing M goes as G^n, if n > -1/2
(including n = 0), the GSL applied to the full range of black holes
theoretically allowed in the present Universe does not constrain an increase in
G but any decrease must be less than about |(1/G) dG/dt| = 10^-52 per second.
If n < -1/2, the GSL does not constrain a decrease in G but any increase must
be less than about |(1/G) dG/dt| = 10^-52 per second. At earlier redshifts,
these constraints weaken as z^3. If n = -1/2, the GSL does not constrain a
decrease but any increase must be less than about |(1/G) dG/dt| = (1/t). If the
mass range is restricted to those black holes which have been astronomically
observed, the present constraints on n > -1/2 and n < -1/2 are only weakened by
a factor of about 10^8 with the tightest constraints coming from stellar mass
black holes and the n = -1/2 bound does not change. The stellar mass black hole
limits should constrain the variation of G in Standard Model physics and all
extension models which approximate classical physics on astronomical scales.


title: Quantum-Hall activation gaps in graphene

abstract:
  We have measured the quantum-Hall activation gaps in graphene at filling
factors $\nu=2$ and $\nu=6$ for magnetic fields up to 32 T and temperatures
from 4 K to 300 K. The $\nu =6$ gap can be described by thermal excitation to
broadened Landau levels with a width of 400 K. In contrast, the gap measured at
$\nu=2$ is strongly temperature and field dependent and approaches the expected
value for sharp Landau levels for fields $B > 20$ T and temperatures $T > 100$
K. We explain this surprising behavior by a narrowing of the lowest Landau
level.


title:
Non-thermal recombination - a neglected source of flare hard X-rays and
  fast electron diagnostic

abstract:
  Context. Flare Hard X-Rays (HXRs) from non-thermal electrons are commonly
treated as solely bremsstrahlung (f-f), recombination (f-b) being neglected.
This assumption is shown to be substantially in error, especially in hot
sources, mainly due to recombination onto Fe ions.
  Aims. We analyse the effects on HXR spectra and electron diagnostics by
including non-thermal recombination onto heavy elements in our model.
  Methods. Using Kramers hydrogenic cross sections with effective Z, we
calculate f-f and f-b spectra for power-law electron spectra, in both thin and
thick target limits, and for Maxwellians, with summation over all important
ions.
  Results. We find that non-thermal electron recombination, especially onto Fe,
must, in general, be included together with f-f, for reliable spectral
interpretation, when the HXR source is hot. f-b contribution is greatest when
the electron spectral index is large, and any low energy cut-off small. f-b
spectra recombination edges mean a cut-off in F(E) appears as a HXR feature at
Photon energy = Ec + Vz, offering an Ec diagnostic. Including f-b lowers,
greatly in some cases, the F(E) needed for prescribed HXR fluxes and, even when
small, seriously distorts F(E) as inferred by inversion or forward fitting
based on f-f alone.
  Conclusions. f-b recombination from non-thermal electrons can be an important
contributor to HXR spectra and should be included in spectral analyses,
especially for hot sources. Accurate results will require use of better cross
sections than ours and consideration of source ionisation structure.


title:
M\'ethodologie de mod\'elisation et d'impl\'ementation d'adaptateurs
  spatio-temporels

abstract:
  The re-use of pre-designed blocks is a well-known concept of the software
development. This technique has been applied to System-on-Chip (SoC) design
whose complexity and heterogeneity are growing. The re-use is made thanks to
high level components, called virtual components (IP), available in more or
less flexible forms. These components are dedicated blocks: digital signal
processing (DCT, FFT), telecommunications (Viterbi, TurboCodes),... These
blocks rest on a model of fixed architecture with very few degrees of
personalization. This rigidity is particularly true for the communication
interface whose orders of acquisition and production of data, the temporal
behavior and protocols of exchanges are fixed. The successful integration of
such an IP requires that the designer (1) synchronizes the components (2)
converts the protocols between "incompatible" blocks (3) temporizes the data to
guarantee the temporal constraints and the order of the data. This phase
remains however very manual and source of errors. Our approach proposes a
formal modeling, based on an original Ressource Compatibility Graph. The
synthesis flow is based on a set of transformations of the initial graph to
lead to an interface architecture allowing the space-time adaptation of the
data exchanges between several components.