title:
Nonlinear Elasticity, Fluctuations and Heterogeneity of Nematic
  Elastomers

abstract:
  Liquid crystal elastomers realize a fascinating new form of soft matter that
is a composite of a conventional crosslinked polymer gel (rubber) and a liquid
crystal. These {\em solid} liquid crystal amalgams, quite similarly to their
(conventional, fluid) liquid crystal counterparts, can spontaneously partially
break translational and/or orientational symmetries, accompanied by novel soft
Goldstone modes. As a consequence, these materials can exhibit unconventional
elasticity characterized by symmetry-enforced vanishing of some elastic moduli.
Thus, a proper description of such solids requires an essential modification of
the classical elasticity theory. In this work, we develop a {\em rotationally
invariant}, {\em nonlinear} theory of elasticity for the nematic phase of ideal
liquid crystal elastomers. We show that it is characterized by soft modes,
corresponding to a combination of long wavelength shear deformations of the
solid network and rotations of the nematic director field. We study thermal
fluctuations of these soft modes in the presence of network heterogeneities and
show that they lead to a large variety of anomalous elastic properties, such as
singular length-scale dependent shear elastic moduli, a divergent elastic
constant for splay distortion of the nematic director, long-scale
incompressibility, universal Poisson ratios and a nonlinear stress-strain
relation fo arbitrary small strains. These long-scale elastic properties are
{\em universal}, controlled by a nontrivial zero-temperature fixed point and
constitute a qualitative breakdown of the classical elasticity theory in
nematic elastomers. Thus, nematic elastomers realize a stable ``critical
phase'', characterized by universal power-law correlations, akin to a critical
point of a continuous phase transition, but extending over an entire phase.


title:
Experimental study on Gaussian-modulated coherent states quantum key
  distribution over standard telecom fiber

abstract:
  In this paper, we present a fully fiber-based one-way Quantum Key
Distribution (QKD) system implementing the Gaussian-Modulated Coherent States
(GMCS) protocol. The system employs a double Mach-Zehnder Interferometer (MZI)
configuration in which the weak quantum signal and the strong Local Oscillator
(LO) go through the same fiber between Alice and Bob, and are separated into
two paths inside Bob's terminal. To suppress the LO leakage into the signal
path, which is an important contribution to the excess noise, we implemented a
novel scheme combining polarization and frequency multiplexing, achieving an
extinction ratio of 70dB. To further minimize the system excess noise due to
phase drift of the double MZI, we propose that, instead of employing phase
feedback control, one simply let Alice remap her data by performing a rotation
operation. We further present noise analysis both theoretically and
experimentally. Our calculation shows that the combined polarization and
frequency multiplexing scheme can achieve better stability in practice than the
time-multiplexing scheme, because it allows one to use matched fiber lengths
for the signal and the LO paths on both sides of the double MZI, greatly
reducing the phase instability caused by unmatched fiber lengths. Our
experimental noise analysis quantifies the three main contributions to the
excess noise, which will be instructive to future studies of the GMCS QKD
systems. Finally, we demonstrate, under the "realistic model" in which Eve
cannot control the system within Bob's terminal, a secure key rate of
0.3bit/pulse over a 5km fiber link. This key rate is about two orders of
magnitude higher than that of a practical BB84 QKD system.


title: Generalized sine-Gordon model and baryons in two-dimensional QCD

abstract:
  We consider the sl(3,C) affine Toda model coupled to matter (Dirac spinor)
(ATM) and through a gauge fixing procedure we obtain the classical version of
the generalized sl(3,C) sine-Gordon model (cGSG) which completely decouples
from the Dirac spinors. The GSG models are multifield extensions of the
ordinary sine-Gordon model. In the spinor sector we are left with Dirac fields
coupled to cGSG fields. Based on the equivalence between the U(1) vector and
topological currents, which holds in the theory, it is shown the confinement of
the spinors inside the solitons and kinks of the cGSG model providing an
extended hadron model for "quark" confinement [JHEP0701(2007)027]. Moreover,
the solitons and kinks of the generalized sine-Gordon (GSG) model are shown to
describe the normal and exotic baryon spectrum of two-dimensional QCD. The GSG
model arises in the low-energy effective action of bosonized QCD2 with unequal
quark mass parameters [JHEP0703(2007)055]. The GSG potential for three flavors
resembles the potential of the effective chiral lagrangian proposed by Witten
to describe low-energy behavior of four dimensional QCD. Among the attractive
features of the GSG model are the variety of soliton and kink type solutions
for QCD2 unequal quark mass parameters. Exotic baryons in QCD2 [ Ellis and
Frishman, JHEP0508(2005)081] are discussed in the context of the GSG model.
Various semi-classical computations are performed improving previous results
and clarifying the role of unequal quark masses. The remarkable double sine
Gordon model also arises as a reduced GSG model bearing a kink(K) type solution
describing a multi-baryon.


title: Fermions on one or fewer Kinks

abstract:
  We find the full spectrum of fermion bound states on a Z_2 kink. In addition
to the zero mode, there are int[2 m_f/m_s] bound states, where m_f is the
fermion and m_s the scalar mass. We also study fermion modes on the background
of a well-separated kink-antikink pair. Using a variational argument, we prove
that there is at least one bound state in this background, and that the energy
of this bound state goes to zero with increasing kink-antikink separation, 2L,
and faster than e^{-a2L} where a = min(m_s, 2 m_f). By numerical evaluation, we
find some of the low lying bound states explicitly.


title: Development of a thermal ionizer as ion catcher

abstract:
  An effective ion catcher is an important part of a radioactive beam facility
that is based on in-flight production. The catcher stops fast radioactive
products and emits them as singly charged slow ions. Current ion catchers are
based on stopping in He and H$_2$ gas. However, with increasing intensity of
the secondary beam the amount of ion-electron pairs created eventually prevents
the electromagnetic extraction of the radioactive ions from the gas cell. In
contrast, such limitations are not present in thermal ionizers used with the
ISOL production technique. Therefore, at least for alkaline and alkaline earth
elements, a thermal ionizer should then be preferred. An important use of the
TRI$\mu$P facility will be for precision measurements using atom traps. Atom
trapping is particularly possible for alkaline and alkaline earth isotopes. The
facility can produce up to 10$^9$ s$^{-1}$ of various Na isotopes with the
in-flight method. Therefore, we have built and tested a thermal ionizer. An
overview of the operation, design, construction, and commissioning of the
thermal ionizer for TRI$\mu$P will be presented along with first results for
$^{20}$Na and $^{21}$Na.


title: Production and trapping of radioactive atoms at the TRI\muP facility

abstract:
  The structures for the TRI$\mu$P facility have been completed and
commissioned. At the facility radioactive nuclides are produced to study
fundamental interactions and symmetries. An important feature is the
possibility to trap radioactive atoms in order to obtain and hold a pure
substrate-free sample for precision measurements. In the TRI$\mu$P facility a
production target is followed by a magnetic separator, where radioactive
isotopes are produced in inverse reaction kinematics. Separation up to 99.95%
could be achieved for $^{21}$Na. A novel transmitting thermal ionizing device
was developed to stop the energetic isotopes. Some 50% of stopped $^{21}$Na
could be extracted and transported as low energy singly charged ions into a
radio frequency quadrupole cooler and buncher with 35% transmission efficiency.
The ions are transported lossless via a drift tube and a low energy
electrostatic beam line into the experimental setup. Such ions can be
neutralized on hot metal foils and the resulting atoms can be stored in a
magneto-optical trap. The functioning of that principle was demonstrated with
stable Na extracted from the thermal ionizer, radioactive beams will follow
next.


title: A fractal approach to the rheology of concentrated cell suspensions

abstract:
  Results on the rheological behavior of novel CHO cell suspensions in a large
range of concentrations are reported. The concentration dependent yield stress
and elastic plateau modulus are formalized in the context of fractal aggregates
under shear, and quite different exponents are found as compared to the case of
red blood cell suspensions. This is explained in terms of intrinsic microscopic
parameters such as the cell-cell adhesion energy and cell elasticity but also
the cell individual dynamic properties, found to correlate well with
viscoelastic data at large concentrations (phi>0.5).


title: Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy

abstract:
  The expansion of the universe appears to be accelerating, and the mysterious
anti-gravity agent of this acceleration has been called ``dark energy''. To
measure the dynamics of dark energy, Baryon Acoustic Oscillations (BAO) can be
used. Previous discussions of the BAO dark energy test have focused on direct
measurements of redshifts of as many as $10^9$ individual galaxies, by
observing the 21cm line or by detecting optical emission. Here we show how the
study of acoustic oscillation in the 21 cm brightness can be accomplished by
economical three dimensional intensity mapping. If our estimates gain
acceptance they may be the starting point for a new class of dark energy
experiments dedicated to large angular scale mapping of the radio sky, shedding
light on dark energy.


title:
Gauss-Green theorem for weakly differentiable vector fields, sets of
  finite perimeter, and balance laws

abstract:
  We analyze a class of weakly differentiable vector fields (\FF \colon \rn \to
\rn) with the property that (\FF\in L^{\infty}) and (\div \FF) is a Radon
measure. The primary focus of our investigation is to introduce a suitable
notion of the normal trace of any divergence-measure field $\FF$ over the
boundary of an arbitrary set of finite perimeter, which ensures the validity of
the Gauss-Green theorem. To achieve this, we establish a fundamental
approximation theorem which states that, given a Radon measure $\mu$ that is
absolutely continuous with respect to $\mathcal{H}^{N-1}$ on $\rn$, any set of
finite perimeter can be approximated by a family of sets with smooth boundary
essentially from the measure-theoretic interior of the set with respect to the
measure $\|\mu\|$. With this approximation theorem, we derive the normal trace
of $\FF$ on the boundary of any set of finite perimeter, (E), as the limit of
the normal traces of $\FF$ on the boundaries of the approximate sets with
smooth boundary, so that the Gauss-Green theorem for $\FF$ holds on (E). With
these results, we analyze the Cauchy fluxes that are bounded by a Radon measure
over any oriented surface (i.e. an $(N-1)$-dimensional surface that is a part
of the boundary of a set of finite perimeter) and thereby develop a general
mathematical formulation of the physical principle of balance law through the
Cauchy flux. Finally, we apply this framework to the derivation of systems of
balance laws with measure-valued source terms from the formulation of balance
law. This framework also allows the recovery of Cauchy entropy fluxes through
the Lax entropy inequality for entropy solutions of hyperbolic conservation
laws.


title:
Implication of Classical Black Hole Evaporation Conjecture to Floating
  Black Holes

abstract:
  In Randall-Sundrum single-brane (RS-II) model, it was conjectured that there
is no static large black hole localized on the brane based on adS/CFT
correspondence. Here we consider the phase diagram of black objects in the
models extended from the RS-II model. We propose a scenario for the phase
diagram consistent with the classical black hole evaporation conjecture. The
proposed scenario indicates the existence of a rich variety of the families of
black objects.


title: Length control of microtubules by depolymerizing motor proteins

abstract:
  In many intracellular processes, the length distribution of microtubules is
controlled by depolymerizing motor proteins. Experiments have shown that,
following non-specific binding to the surface of a microtubule, depolymerizers
are transported to the microtubule tip(s) by diffusion or directed walk and,
then, depolymerize the microtubule from the tip(s) after accumulating there. We
develop a quantitative model to study the depolymerizing action of such a
generic motor protein, and its possible effects on the length distribution of
microtubules. We show that, when the motor protein concentration in solution
exceeds a critical value, a steady state is reached where the length
distribution is, in general, non-monotonic with a single peak. However, for
highly processive motors and large motor densities, this distribution
effectively becomes an exponential decay. Our findings suggest that such motor
proteins may be selectively used by the cell to ensure precise control of MT
lengths. The model is also used to analyze experimental observations of
motor-induced depolymerization.


title: Haagerup's Approximation Property and Relative Amenability

abstract:
  A finite von Neumann algebra $\mathcal{M}$ with a faithful normal trace $%
\tau $ has Haagerup's approximation property (relative to a von Neumann
subalgebra $\mathcal{N}$) if there exists a net $(\phi_{\alpha})_{\alpha\in
\Lambda}$ of normal completely positive ($\mathcal{N}$-bimodular) maps from
$\mathcal{M}$ to $\mathcal{M}$ that satisfy the subtracial condition $% \tau
\circ \phi_{\alpha}\leq \tau $, the extension operators $% T_{\phi_{\alpha}}$
are bounded compact operators (in $<\mathcal{M%},e_{\mathcal{N}}>$), and
pointwise approximate the identity in the trace-norm, i.e.,
$\lim_{\alpha}||\phi_{\alpha}(x)-x||_{2}=0$ for all $% x\in \mathcal{M}$. We
prove that the subtraciality condition can be removed, and provide a
description of Haagerup's approximation property in terms of Connes's theory of
correspondences. We show that if $\mathcal{N}\subseteq \mathcal{M}$ is an
amenable inclusion of finite von Neumann algebras and $% \mathcal{N}$ has
Haagerup's approximation property, then $\mathcal{M}$ also has Haagerup's
approximation property. This work answers two questions of Sorin Popa.


title:
Detailed description of accelerating, simple solutions of relativistic
  perfect fluid hydrodynamics

abstract:
  In this paper we describe in full details a new family of recently found
exact solutions of relativistic, perfect fluid dynamics. With an ansatz, which
generalizes the well-known Hwa-Bjorken solution, we obtain a wide class of new
exact, explicit and simple solutions, which have a remarkable advantage as
compared to presently known exact and explicit solutions: they do not lack
acceleration. They can be utilized for the description of the evolution of the
matter created in high energy heavy ion collisions. Because these solutions are
accelerating, they provide a more realistic picture than the well-known
Hwa-Bjorken solution, and give more insight into the dynamics of the matter. We
exploit this by giving an advanced simple estimation of the initial energy
density of the produced matter in high energy collisions, which takes
acceleration effects (i.e. the work done by the pressure and the modified
change of the volume elements) into account. We also give an advanced
estimation of the life-time of the reaction. Our new solutions can also be used
to test numerical hydrodynamical codes reliably. In the end, we also give an
exact, 1+1 dimensional, relativistic hydrodynamical solution, where the initial
pressure and velocity profile is arbitrary, and we show that this general
solution is stable for perturbations.


title: The spectral dimension of random brushes

abstract:
  We consider a class of random graphs, called random brushes, which are
constructed by adding linear graphs of random lengths to the vertices of Z^d
viewed as a graph. We prove that for d=2 all random brushes have spectral
dimension d_s=2. For d=3 we have {5\over 2}\leq d_s\leq 3 and for d\geq 4 we
have 3\leq d_s\leq d.


title: Constraining the dark energy and smoothness-parameter with supernovae

abstract:
  The presence of inhomogeneities modifies the cosmic distances through the
gravitational lensing effect, and, indirectly, must affect the main
cosmological tests. Assuming that the dark energy is a smooth component, the
simplest way to account for the influence of clustering is to suppose that the
average evolution of the expanding Universe is governed by the total
matter-energy density whereas the focusing of light is only affected by a
fraction of the total matter density quantified by the $\alpha$ Dyer-Roeder
parameter. By using two different samples of SNe type Ia data, the $\Omega_m$
and $\alpha$ parameters are constrained by applying the
Zeldovich-Kantowski-Dyer-Roeder (ZKDR) luminosity distance redshift relation
for a flat ($\Lambda$CDM) model. A $\chi^{2}$-analysis using the 115 SNe Ia
data of Astier {\it et al.} sample (2006) constrains the density parameter to
be $\Omega_m=0.26_{-0.07}^{+0.17}$($2\sigma$) while the $\alpha$ parameter is
weakly limited (all the values $\in [0,1]$ are allowed even at 1$\sigma$).
However, a similar analysis based the 182 SNe Ia data of Riess {\it et al.}
(2007) constrains the pair of parameters to be $\Omega_m= 0.33^{+0.09}_{-0.07}$
and $\alpha\geq 0.42$ ($2\sigma$). Basically, this occurs because the Riess
{\it et al.} sample extends to appreciably higher redshifts. As a general
result, even considering the existence of inhomogeneities as described by the
smoothness $\alpha$ parameter, the Einstein-de Sitter model is ruled out by the
two samples with a high degree of statistical confidence ($11.5\sigma$ and
$9.9\sigma$, respectively). The inhomogeneous Hubble-Sandage diagram discussed
here highlight the necessity of the dark energy, and a transition
deceleration/accelerating phase at $z\sim 0.5$ is also required.


title:
Inequalities that Collectively Completely Characterize the Catalytic
  Majorization Relation

abstract:
  For probability vectors x and y, the catalytic majorization relation x prec_T
y is defined to hold when there exists a probability vector z such that x
otimes z is majorized by y otimes z. In this paper, an infinite family of
functions is given such that, subject to some trivial restrictions, x prec_T y
if and only if f_r(x) < f_r(y) for all functions f_r in the family. An outline
of a proof of this result is provided. The catalytic majorization relation is
known to provide a determination of which transformations of jointly held pure
quantum states are possible using local operations and classical communication
when an additional jointly held state may be specified to facilitate the
transformation without being consumed.


title: Improved transfer matrix method without numerical instability

abstract:
  A new improved transfer matrix method (TMM) is presented. It is shown that
the method not only overcomes the numerical instability found in the original
TMM, but also greatly improves the scalability of computation. The new improved
TMM has no extra cost of computing time as the length of homogeneous scattering
region becomes large. The comparison between the scattering matrix method(SMM)
and our new TMM is given. It clearly shows that our new method is much faster
than SMM.


title: The Vcirc-sigma0 Relation of Galaxies

abstract:
  Courteau et al. (2007a) reported on the dependence of the ratio of a galaxy's
maximum circular velocity, Vcirc, to its central velocity dispersion, sigma0,
on morphology, or equivalently total light concentration. This Vcirc-sigma0
concentration relation, which involves details about the local and global
galaxy physics, poses a fundamental challenge for galaxy structure models.
Furthermore, not only must these models reproduce the Vcirc-sigma0 relation and
its various dependences, they must simultaneously match other fundamental
scaling relations such as the velocity-size-luminosity and color-luminosity
relations of galaxies. We focus here on the interpretation of parameters that
enter the Vcirc-sigma0 relation to enable proper data-model comparisons and
follow-up studies by galaxy modelers and observers.


title:
Comparative study of nonlinear properties of EEG signals of a normal
  person and an epileptic patient

abstract:
  Background: Investigation of the functioning of the brain in living systems
has been a major effort amongst scientists and medical practitioners. Amongst
the various disorder of the brain, epilepsy has drawn the most attention
because this disorder can affect the quality of life of a person. In this paper
we have reinvestigated the EEGs for normal and epileptic patients using
surrogate analysis, probability distribution function and Hurst exponent.
  Results: Using random shuffled surrogate analysis, we have obtained some of
the nonlinear features that was obtained by Andrzejak \textit{et al.} [Phys Rev
E 2001, 64:061907], for the epileptic patients during seizure. Probability
distribution function shows that the activity of an epileptic brain is
nongaussian in nature. Hurst exponent has been shown to be useful to
characterize a normal and an epileptic brain and it shows that the epileptic
brain is long term anticorrelated whereas, the normal brain is more or less
stochastic. Among all the techniques, used here, Hurst exponent is found very
useful for characterization different cases.
  Conclusions: In this article, differences in characteristics for normal
subjects with eyes open and closed, epileptic subjects during seizure and
seizure free intervals have been shown mainly using Hurst exponent. The H shows
that the brain activity of a normal man is uncorrelated in nature whereas,
epileptic brain activity shows long range anticorrelation.


title: Hawking Radiation of Black p-Branes from Gravitational Anomaly

abstract:
  We investigate the Hawking radiation of black $p$-branes of superstring
theories using the method of anomaly cancelation, specially, we use the method
of [S. Iso, H. Umetsu and F. Wilczek, {\sl Phys. Rev. Lett.} {\bf 96}, 151302
(2006); {\sl Phys. Rev. D} {\bf 74}, 044017 (2006)]. The metrics of black
$p$-branes are spherically symmetric, but not the Schwarzschild type. In order
to simplify the calculation, we first make a coordinate transformation to
transform the metric to the Schwarzschild type. Then we calculate its
energy-momentum flux from the method of anomaly cancelation of the above
mentioned references. The obtained energy-momentum flux is equal to a black
body radiation, the thermodynamic temperature of the radiation is equal to its
Hawking temperature. And we find that the results are not changed for the
original non-Schwarzschild type spherically symmetric metric.


title: The Spin Density Matrix II: Application to a system of two quantum dots

abstract:
  This work is a sequel to our work "The Spin Density Matrix I: General Theory
and Exact Master Equations" (eprint arXiv:0708.0644 [cond-mat]). Here we
compare pure- and pseudo-spin dynamics using as an example a system of two
quantum dots, a pair of localized conduction-band electrons in an n-doped GaAs
semiconductor. Pure-spin dynamics is obtained by tracing out the orbital
degrees of freedom, whereas pseudo-spin dynamics retains (as is conventional)
an implicit coordinate dependence. We show that magnetic field inhomogeneity
and spin-orbit interaction result in a non-unitary evolution in pure-spin
dynamics, whereas these interactions contribute to the effective pseudo-spin
Hamiltonian via terms that are asymmetric in spin permutations, in particular,
the Dzyaloshinskii-Moriya (DM) spin-orbit interaction. We numerically
investigate the non-unitary effects in the dynamics of the triplet states
population, purity, and Lamb energy shift, as a function of interdot distance
and magnetic field difference. The spin-orbit interaction is found to produce
effects of roughly four orders of magnitude smaller than those due to magnetic
field difference in the pure-spin model. We estimate the spin-orbit interaction
magnitude in the DM-interaction term. Our estimate gives a smaller value than
that recently obtained by Kavokin [Phys. Rev. B 64, 075305 (2001)], who did not
include double occupancy effects. We show that a necessary and sufficient
condition for obtaining a universal set of quantum logic gates, involving only
two spins, in both pure- and pseudo-spin models is that the magnetic field
inhomogeneity and the Heisenberg interaction are both non-vanishing. We also
briefly analyze pure-spin dynamics in the electron on liquid helium system
recently proposed by Lyon [Phys. Rev. A 74, 052338 (2006)].


title: Curvature estimates for minimal submanifolds of higher codimension

abstract:
  We derive curvature estimates for minimal submanifolds in Euclidean space for
arbitrary dimension and codimension via Gauss map. Thus, Schoen-Simon-Yau's
results and Ecker-Huisken's results are generalized to higher codimension. In
this way we improve Hildebrandt-Jost-Widman's result for the Bernstein type
theorem.


title: Nonlinear Dynamics of the Parker Scenario for Coronal Heating

abstract:
  The Parker or field line tangling model of coronal heating is studied
comprehensively via long-time high-resolution simulations of the dynamics of a
coronal loop in cartesian geometry within the framework of reduced
magnetohydrodynamics (RMHD). Slow photospheric motions induce a Poynting flux
which saturates by driving an anisotropic turbulent cascade dominated by
magnetic energy. In physical space this corresponds to a magnetic topology
where magnetic field lines are barely entangled, nevertheless current sheets
(corresponding to the original tangential discontinuities hypothesized by
Parker) are continuously formed and dissipated.
  Current sheets are the result of the nonlinear cascade that transfers energy
from the scale of convective motions ($\sim 1,000 km$) down to the dissipative
scales, where it is finally converted to heat and/or particle acceleration.
Current sheets constitute the dissipative structure of the system, and the
associated magnetic reconnection gives rise to impulsive ``bursty'' heating
events at the small scales. This picture is consistent with the slender loops
observed by state-of-the-art (E)UV and X-ray imagers which, although apparently
quiescent, shine bright in these wavelengths with little evidence of entangled
features.
  The different regimes of weak and strong MHD turbulence that develop, and
their influence on coronal heating scalings, are shown to depend on the loop
parameters, and this dependence is quantitatively characterized: weak
turbulence regimes and steeper spectra occur in {\it stronger loop fields} and
lead to {\it larger heating rates} than in weak field regions.


title: Some Impacts of Lorentz Violation on Cosmology

abstract:
  The impact of Lorentz violation on the dynamics of a scalar field is
investigated. In particular, we study the dynamics of a scalar field in the
scalar-vector-tensor theory where the vector field is constrained to be unity
and time like. By taking a generic form of the scalar field action, a
generalized dynamical equation for the scalar-vector-tensor theory of gravity
is obtained to describe the cosmological solutions. We present a class of exact
solutions for an ordinary scalar field or phantom field corresponding to a
power law coupling vector and the Hubble parameter. As the results, we find a
constant equation of state in de Sitter space-time and power law expansion with
the quadratic of coupling vector, while a dynamic equation of state is obtained
for $n> 2$. Then, we consider the inflationary scenario based on the Lorentz
violating scalar-vector-tensor theory of gravity with general power-law
coupling vector and two typical potentials: inverse power-law and power-law
potentials. In fact, both the coupling vector and the potential models affect
the dynamics of the inflationary solutions. Finally, we use the dynamical
system formalism to study the attractor behavior of a cosmological model
containing a scalar field endowed with a quadratic coupling vector and a
chaotic potential.


title: Static Deadlock Detection in MPI Synchronization Communication

abstract:
  It is very common to use dynamic methods to detect deadlocks in MPI programs
for the reason that static methods have some restrictions. To guarantee high
reliability of some important MPI-based application software, a model of MPI
synchronization communication is abstracted and a type of static method is
devised to examine deadlocks in such modes. The model has three forms with
different complexity: sequential model, single-loop model and nested-loop
model. Sequential model is a base for all models. Single-loop model must be
treated with a special type of equation group and nested-loop model extends the
methods for the other two models. A standard Java-based software framework
originated from these methods is constructed for determining whether MPI
programs are free from synchronization communication deadlocks. Our practice
shows the software framework is better than those tools using dynamic methods
because it can dig out all synchronization communication deadlocks before an
MPI-based program goes into running.


title: Pioneer anomaly: a drift in the proper time of the spacecraft

abstract:
  A relativistic theory is proposed to explain the anomalous accelerations of
Pioneer 10/11, Galileo and Ulysses spacecrafts. The theory points out at the
limitations of the weak field approximation and proposes a drift in the proper
time of the spacecraft outside the framework of general relativity. The theory
yields a very accurate and precise value for the anomalous acceleration. In
this theory the proper time of a body is associated with the gravitational
frequency shift of the constituent fundamental particles of the body. The
frequency shift changes the energy level of the body which gets reflected in
its relativistic mass and therefore in its motion. This change in energy level
causes the time like geodesics to deviate from that of the standard theoretical
models. We introduce proper time in the line element of a metric theory
according to a fixed set of rules laid down by general relativity for
introducing deviation in the flat Minkowski metric. The frequency shift for
bodies of different composition traversing different trajectories however, is
not the same and this gets reflected in its motion as an unmodeled anomalous
effect. This association of proper time with the gravitational frequency shift
of the body requires the flat Minkowski metric to deviate in different ways for
different two body systems. The solution to Pioneer anomaly given here yields
anomalous acceleration within the limits of observational accuracy.
Gravitational redshift of light, bending of light and perihelic precession of
planets are within the permissible limits. The theory shows that Einstein's
field equations do provide some clue to the Pioneer anomaly but the solution is
not very accurate. The theory can also explain the rotation curves of the
spiral galaxies.


title: Negative reflection in a Faraday chiral medium

abstract:
  The four wavenumbers associated with planewave propagation in a Faraday
chiral medium (FCM) with relatively huge magnetoelectric coupling give rise to
enhanced possibilities for negative-phase-velocity propagation and therefore
negative refraction. They can also give rise to the phenomenon of negative
reflection. In particular, for a nondissipative example, we deduced that an
incident plane wave with positive/negative phase velocity can result in a
negatively reflected plane wave with negative/positive phase velocity, as well
as a positively reflected plane wave with positive/negative phase velocity.


title:
Deadlock Detection in Basic Models of MPI Synchronization Communication
  Programs

abstract:
  A model of MPI synchronization communication programs is presented and its
three basic simplified models are also defined. A series of theorems and
methods for deciding whether deadlocks will occur among the three models are
given and proved strictly. These theories and methods for simple models'
deadlock detection are the necessary base for real MPI program deadlock
detection. The methods are based on a static analysis through programs and with
runtime detection in necessary cases and they are able to determine before
compiling whether it will be deadlocked for two of the three basic models. For
another model, some deadlock cases can be found before compiling and others at
runtime. Our theorems can be used to prove the correctness of currently popular
MPI program deadlock detection algorithms. Our methods may decrease codes that
those algorithms need to change to MPI source or profiling interface and may
detects deadlocks ahead of program execution, thus the overheads can be reduced
greatly.


title:
Algorithm of Static Deadlock Detection in MPI Synchronization
  Communication Sequential Model

abstract:
  Detecting deadlocks in MPI synchronization communication programs is very
difficult and need building program models. All complex models are based on
sequential models. The sequential model is mapped into a set of character
strings and its deadlock detection problem is translated into an equivalent
multi-queue string matching problem. An algorithm is devised and implemented to
statically detect deadlocks in sequential models of MPI synchronization
communication programs. The time and space complexity of the algorithm is O(n)
where n is the amount of message in model. The algorithm is better than usual
circle-detection methods and can adapt well to dynamic message stream.


title: The coupling of dynamics and molecular chemistry in galaxies

abstract:
  While the best tracer of the molecular component and its dynamics in galaxies
is the CO molecule, which excitation is revealed by its isotopic and
(2-1)/(1-0) ratios, the denser gas is revealed by molecules such as HCN, HNC,
HCO+ or CN, which are now widely used to probe star formation regions, or to
quantify the impact of the nuclear activity on the interstellar medium.
  This paper reviews recent observations in nearby galaxies, where these
molecular line ratios serve as diagnostic tools of the physical conditions of
the gas and also of its chemical properties. Those differ significantly
according to the proximity of an AGN or of a starburst. The origin of the
differences is not yet well known and could be due to different densities,
temperatures, chemical abundances or non-collisional excitation of the gas
(e.g. Aalto et al 2007, Krips et al 2007).
  HCN or HNC line enhancements can be caused not only by higher gas
densities/temperatures, but also UV/X-ray radiation, and global IR pumping. The
chemistry can be dominated by PDR regions near a starburst, or X-ray dominated
in a molecular torus surrounding an AGN (XDR regions). The molecular line
ratios expected in those regions vary according to the different models
(Meijerink et al. 2007).


title: Observations of 1ES 0647+250 and 1ES 0806+524 with VERITAS

abstract:
  Observations of the blazars 1ES 0647+250 and 1ES 0806+524 with VERITAS are
reported here. These objects are among the favoured candidate extragalactic
sources in the very high-energy regime due to the presence of high-energy
electrons and adequate seed photons. The presence of high-energy electrons is
established from the location of the synrchrotron peak in the spectral energy
distribution of the blazars. The presence of adequate seed photons is
determined by the flux in the radio-through-optical wavebands. These are the
key ingredients for very high-energy gamma-ray emission in the context of the
synchrotron self-Compton model. The redshift of 1ES 0647+250 has been
tentatively reported as 0.203 and the redshift of 1ES 0806+524 is 0.138, thus
the detection of very high-energy gamma-ray emission from these objects could
make significant contributions to the understanding of the extragalactic
infrared background light. The analysis of these data relies on standard
techniques in very high-energy gamma-ray astronomy, and the results are
compared to previously reported upper limits and to theoretical predictions.


title: DAFNE Status and Upgrade Plans

abstract:
  The Frascati Phi-factory DAFNE has successfully completed experimental runs
for the three main detectors, KLOE, FINUDA and DEAR. The best peak luminosity
achieved so far is 1.6x10^32 cm-2s-1, while the best daily integrated
luminosity is 10 pb-1. At present the DAFNE team is preparing an upgrade of the
collider based on the novel crab waist collision scheme. The upgrade is aimed
at pushing the luminosity towards 10^33 cm-2s-1. In this paper we describe
present collider performance and discuss ongoing preparatory work for the
upgrade.


title: On the harmonic oscillator on the Lobachevsky plane

abstract:
  We introduce the harmonic oscillator on the Lobachevsky plane with the aid of
the potential $V(r)=(a^2\omega^2/4)sinh(r/a)^2$ where $a$ is the curvature
radius and $r$ is the geodesic distance from a fixed center. Thus the potential
is rotationally symmetric and unbounded likewise as in the Euclidean case. The
eigenvalue equation leads to the differential equation of spheroidal functions.
We provide a basic numerical analysis of eigenvalues and eigenfunctions in the
case when the value of the angular momentum, $m$, equals 0.


title: Miscellaneous Applications of Quons

abstract:
  This paper deals with quon algebras or deformed oscillator algebras, for
which the deformation parameter is a root of unity. We show the interest of
such algebras for fractional supersymmetric quantum mechanics, angular momentum
theory and quantum information. More precisely, quon algebras are used for (i)
a realization of a generalized Weyl-Heisenberg algebra from which it is
possible to associate a fractional supersymmetric dynamical system, (ii) a
polar decomposition of SU_2 and (iii) a construction of mutually unbiased bases
in Hilbert spaces of prime dimension. We also briefly discuss (symmetric
informationally complete) positive operator valued measures in the spirit of
(iii).


title: Flatness-based pre-compensation of laser diodes

abstract:
  A physical nonlinear dynamical model of a laser diode is considered. We
propose a feed-forward control scheme based on differential flatness for the
design of input-current modulations to compensate diode distortions. The goal
is to transform without distortion a radio-frequency current modulation into a
light modulation leaving the laser-diode and entering an optic fiber. We prove
that standard physical dynamical models based on dynamical electron and photons
balance are flat systems when the current is considered as control input, the
flat output being the photon number (proportional to the light power). We prove
that input-current is an affine map of the flat output, its logarithm and their
time-derivatives up to order two. When the flat output is an almost harmonic
signal with slowly varying amplitude and phase, these derivatives admit precise
analytic approximations. It is then possible to design simple analogue
electronic circuits to code approximations of the nonlinear computations
required by our flatness-based approach. Simulations with the parameters of a
commercial diode illustrate the practical interest of this pre-compensation
scheme and its robustness versus modelling and analogue implementation errors.


title:
Orientation dependence of the optical spectra in graphene at high
  frequencies

abstract:
  On the basis of the Kubo formula we evaluated the optical conductivity of a
graphene sheet. The full behavior of frequency as well as temperature
dependence of the optical conductivity is presented. We show that the
anisotropy of conductivity can be significantly enhanced at high frequencies.
The photon absorption depends on the field polarization direction. At the
frequency comparable to the maximum separation of upper and lower bands the
photon-induced conduction of electrons is strongly suppressed if the
polarization of field is along the zigzag direction. The corresponding optical
conductivity is several orders of magnitude weaker than that when the light is
polarizing along the armchair direction. We propose that the property of
orientation selection of absorption in the graphene can be used as a basis for
a high-frequency partial polarizer.


title:
Controlled coupling of counterpropagating whispering-gallery modes by a
  single Rayleigh scatterer: a classical problem in a quantum optical light

abstract:
  We present experiments where a single subwavelength scatterer is used to
examine and control the back-scattering induced coupling between
counterpropagating high-Q modes of a microsphere resonator. Our measurements
reveal the standing wave character of the resulting symmetric and antisymmetric
eigenmodes, their unbalanced intensity distributions, and the coherent nature
of their coupling. We discuss our findings and the underlying classical physics
in the framework common to quantum optics and provide a particularly intuitive
explanation of the central processes.


title: The Chow rings of the algebraic groups E_6, E_7, and E_8

abstract:
  We determine the Chow rings of the complex algebraic groups of the
exceptional type E_6, E_7, and E_8, giving the explicit generators represented
by the pull-back images of Schubert varieties of the corresponding flag
varieties. This is a continuation of the work of R. Marlin on the computation
of the Chow rings of SO_n, Spin_n, G_2, and F_4. Our method is based on
Schubert calculus of the corresponding flag varieties, which has its own
interest.


title: Decay Rates for Spherical Scalar Waves in the Schwarzschild Geometry

abstract:
  The Cauchy problem is considered for the scalar wave equation in the
Schwarzschild geometry. Using an integral spectral representation we derive the
exact decay rate for solutions of the Cauchy problem with spherical symmetric
initial data, which is smooth and compactly supported outside the event
horizon.


title:
Multiscale expansion and integrability properties of the lattice
  potential KdV equation

abstract:
  We apply the discrete multiscale expansion to the Lax pair and to the first
few symmetries of the lattice potential Korteweg-de Vries equation. From these
calculations we show that, like the lowest order secularity conditions give a
nonlinear Schroedinger equation, the Lax pair gives at the same order the
Zakharov and Shabat spectral problem and the symmetries the hierarchy of point
and generalized symmetries of the nonlinear Schroedinger equation.


title: First Steps in Tropical Intersection Theory

abstract:
  We establish first parts of a tropical intersection theory. Namely, we define
cycles, Cartier divisors and intersection products between these two (without
passing to rational equivalence) and discuss push-forward and pull-back. We do
this first for fans in R^n and then for "abstract" cycles that are fans
locally. With regard to applications in enumerative geometry, we finally have a
look at rational equivalence and intersection products of cycles and cycle
classes in R^n.


title:
Static friction on the fly: velocity depinning transitions of lubricants
  in motion

abstract:
  The dragging velocity of a model solid lubricant confined between sliding
periodic substrates exhibits a phase transition between two regimes,
respectively with quantized and with continuous lubricant center-of-mass
velocity. The transition, occurring for increasing external driving force F_ext
acting on the lubricant, displays a large hysteresis, and has the features of
depinning transitions in static friction, only taking place on the fly.
Although different in nature, this phenomenon appears isomorphic to a static
Aubry depinning transition in a Frenkel-Kontorova model, the role of particles
now taken by the moving kinks of the lubricant-substrate interface. We suggest
a possible realization in 2D optical lattice experiments.


title: An Invitation to Random Schroedinger operators

abstract:
  This review is an extended version of my mini course at the Etats de la
recherche: Operateurs de Schroedinger aleatoires at the Universite Paris 13 in
June 2002, a summer school organized by Frederic Klopp. These lecture notes try
to give some of the basics of random Schroedinger operators. They are meant for
nonspecialists and require only minor previous knowledge about functional
analysis and probability theory. Nevertheless this survey includes complete
proofs of Lifshitz tails and Anderson localization.


title: B meson excitations with chirally improved light quarks

abstract:
  We present our latest results for the excitations of static-light mesons on
both quenched and unquenched lattices, where the light quarks are simulated
using the chirally improved (CI) lattice Dirac operator.


title: On vortices and solitons in Goldstone and abelian-Higgs models

abstract:
  In the present work we discuss non-linear physics problems such as
Nielsen-Olesen strings, superconducting bosonic straight strings and static
vortex rings. We start with a toy model. We search for antiperiodic solitons of
the Goldstone model on a circle. Such models provide the basis as well as
useful hints for further research on three-dimensional more realistic problems.
We proceed with a full research on a $U(1)$ model which admits stable straight
string solutions in a small, numerically determined area. That model has a
Ginzburg-Landau potential with a cubic term added to it and can be found in
condensed matter problems as well. The next part of our research, has to do
with a $U(1) \times U(1)$ model which is the main subject of our interest.
There, we search for stable axially symmetric solutions which are solitons,
which can represent particles, the mass of which is of the order of TeV. The
confirmation or rejection of the existence of those defects is of great
interest if we consider that LHC will work in the same energy range. In our
study, we find out that due to current quenching, these vortex rings seem to be
unstable. We also extend the model of vortex rings by adding higher derivative
terms which are favorable for stability. After the extensive analysis we
performed, we conclude that these objects donât seem to be stable. The reasons
which brought us to this conclusion are explained.


title:
Bidding Strategy with Forecast Technology Based on Support Vector
  Machine in Electrcity Market

abstract:
  The participants of the electricity market concern very much the market price
evolution. Various technologies have been developed for price forecast. SVM
(Support Vector Machine) has shown its good performance in market price
forecast. Two approaches for forming the market bidding strategies based on SVM
are proposed. One is based on the price forecast accuracy, with which the being
rejected risk is defined. The other takes into account the impact of the
producer's own bid. The risks associated with the bidding are controlled by the
parameters setting. The proposed approaches have been tested on a numerical
example.


title:
Mott-Hubbard versus charge-transfer behavior in LaSrMnO4 studied via
  optical conductivity

abstract:
  Using spectroscopic ellipsometry, we study the optical conductivity
sigma(omega) of insulating LaSrMnO4 in the energy range of 0.75-5.8 eV from 15
to 330 K. The layered structure gives rise to a pronounced anisotropy. A
multipeak structure is observed in sigma_1^a(omega) (2, 3.5, 4.5, 4.9, and 5.5
eV), while only one peak is present at 5.6 eV in sigma_1^c(omega). We employ a
local multiplet calculation and obtain (i) an excellent description of the
optical data, (ii) a detailed peak assignment in terms of the multiplet
splitting of Mott-Hubbard and charge-transfer absorption bands, and (iii)
effective parameters of the electronic structure, e.g., the on-site Coulomb
repulsion U_eff=2.2 eV, the in-plane charge-transfer energy Delta_a=4.5 eV, and
the crystal-field parameters for the d^4 configuration (10 Dq=1.2 eV,
Delta_eg=1.4 eV, and Delta_t2g=0.2 eV). The spectral weight of the lowest
absorption feature (at 1-2 eV) changes by a factor of 2 as a function of
temperature, which can be attributed to the change of the nearest-neighbor
spin-spin correlation function across the Neel temperature. Interpreting
LaSrMnO4 effectively as a Mott-Hubbard insulator naturally explains this strong
temperature dependence, the relative weight of the different absorption peaks,
and the pronounced anisotropy. By means of transmittance measurements, we
determine the onset of the optical gap Delta^a_opt=0.4-0.45 eV at 15 K and
0.1-0.2 eV at 300 K. Our data show that the crystal-field splitting is too
large to explain the anomalous temperature dependence of the c-axis lattice
parameter by thermal occupation of excited crystal-field levels. Alternatively,
we propose that a thermal population of the upper Hubbard band gives rise to
the shrinkage of the c-axis lattice parameter.


title:
Long term hard X-ray variability of the anomalous X-ray pulsar 1RXS
  J170849.0-400910 discovered with INTEGRAL

abstract:
  We report on a multi-band high-energy observing campaign aimed at studying
the long term spectral variability of the Anomalous X-ray Pulsar (AXP) 1RXS
J170849.0-400910, one of the magnetar candidates. We observed 1RXS
J170849.0-400910 in Fall 2006 and Spring 2007 simultaneously with Swift/XRT, in
the 0.1-10 keV energy range, and with INTEGRAL/IBIS, in the 20-200 keV energy
range. Furthermore, we also reanalyzed, using the latest calibration and
software, all the publicly available INTEGRAL data since 2002, and the soft
X-ray data starting from 1999 taken using BeppoSAX, Chandra, XMM, and
Swift/XRT, in order to study the soft and hard X-ray spectral variability of
1RXS J170849.0-400910. We find a long-term variability of the hard X-ray flux,
extending the hardness-intensity correlation proposed for this source over 2
orders of magnitude in energy.


title:
Existence, uniqueness and approximation for stochastic Schrodinger
  equation: the Poisson case

abstract:
  In quantum physics, recent investigations deal with the so-called "quantum
trajectory" theory. Heuristic rules are usually used to give rise to
"stochastic Schrodinger equations" which are stochastic differential equations
of non-usual type describing the physical models. These equations pose tedious
problems in terms of mathematical justification: notion of solution, existence,
uniqueness, justification... In this article, we concentrate on a particular
case: the Poisson case. Random measure theory is used in order to give rigorous
sense to such equations. We prove existence and uniqueness of a solution for
the associated stochastic equation. Furthermore, the stochastic model is
physically justified by proving that the solution can be obtained as a limit of
a concrete discrete time physical model.


title: Quasinormal Modes and Late-Time Tails of Canonical Acoustic Black Holes

abstract:
  In this paper, we investigate the evolution of classical wave propagation in
the canonical acoustic black hole by numerical method and discuss the details
of tail phenomenon. The oscillating frequency and damping time scale both
increase with the angular momentum $l$. For the lower $l$, numerical results
show the lowest WKB approximation gives the most reliable result. We also find
that time scale of the interim region from ringing to tail is not affected
obviously by changing $l$.


title: Criteria for homotopic maps to be so along monotone homotopies

abstract:
  The state spaces of machines admit the structure of time. A homotopy theory
respecting this additional structure can detect machine behavior unseen by
classical homotopy theory. In an attempt to bootstrap classical tools into the
world of abstract spacetime, we identify criteria for classically homotopic,
monotone maps of pospaces to future homotope, or homotope along homotopies
monotone in both coordinates, to a common map. We show that consequently, a
hypercontinuous lattice equipped with its Lawson topology is future
contractible, or contractible along a future homotopy, if its underlying space
has connected CW type.


title:
Numerical Improvement of the Discrete Element Method applied to Shear of
  Granular Media

abstract:
  We present a detailed analysis of the bounds on the integration step in
Discrete Element Method (DEM) for simulating collisions and shearing of
granular assemblies. We show that, in the numerical scheme, the upper limit for
the integration step, usually taken from the average time $t_c$ of one contact,
is in fact not sufficiently small to guarantee numerical convergence of the
system during relaxation. In particular, we study in detail how the kinetic
energy decays during the relaxation stage and compute the correct upper limits
for the integration step, which are significantly smaller than the ones
commonly used. In addition, we introduce an alternative approach, based on
simple relations to compute the frictional forces, that converges even for
integration steps above the upper limit.


title: Fermions with spin 1/2 as global SO(3) vortices

abstract:
  In this paper we show that the nontrivial fundamental group $\pi_1 SO(3)
={\Bbb Z}_2$ for the group SO(3) of global proper rotations of a
four-dimensional Euclidian space (when a spin structure is introduced
preliminarily in that space) implies always fermions as global SO(3) vortices,
while bosons can be reduced to trivial lines (contracted into a point) in the
SO(3) group space.


title:
Electronic correlations and disorder in transport through
  one-dimensional nanoparticle arrays

abstract:
  We analyze and clarify the transport properties of a one-dimensional metallic
nanoparticle array with interaction between charges restricted to charges
placed in the same conductor. We study the threshold voltage, the I-V curves
and the potential drop through the array and their dependence on the array
parameters including the effect of charge and resistance disorder. We show that
very close to threshold the current depends linearly on voltage with a slope
independent on the array size. At intermediate bias voltages, for which a
Coulomb staircase is observed we find that the average potential drop through
the array oscillates with position. At higher voltages I-V curves are linear
but have a finite offset voltage. We show that the slope is given by the
inverse of the resistances added in series and estimate the voltage at which
this linear regime is reached. We also calculate the offset voltage and relate
it to the potential drop through the array.


title:
Implementation of the Random Forest Method for the Imaging Atmospheric
  Cherenkov Telescope MAGIC

abstract:
  The paper describes an application of the tree classification method Random
Forest (RF), as used in the analysis of data from the ground-based gamma
telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to
be discriminated against a dominating background of hadronic cosmic-ray
particles. We describe the application of RF for this gamma/hadron separation.
The RF method often shows superior performance in comparison with traditional
semi-empirical techniques. Critical issues of the method and its implementation
are discussed. An application of the RF method for estimation of a continuous
parameter from related variables, rather than discrete classes, is also
discussed.


title: Magnetoresistance in an all-manganite heterostructure

abstract:
  We study the magnetic and transport properties of all-manganite
heterostructures consisting of ferromagnetic metallic electrodes separated by
an antiferromagnetic barrier. We find that the magnetic ordering in the barrier
is influenced by the relative orientation of the electrodes magnetization
producing a large difference in resistance between the parallel and
antiparallel orientations of the ferromagnetic layers. The external application
of a magnetic field in a parallel configuration also leads to large
magnetoresistance.


title:
Millimeter observations of HCM6A, a gravitationally lensed Lyman alpha
  emitting galaxy at z=6.56

abstract:
  The gravitationally lensed Lyman-alpha emitting galaxy, HCM6A, detected by Hu
et al. (2002) at z=6.56 behind the Abell 370 cluster was observed with the
MAMBO-2 array of bolometers at 1.2mm wavelength. The galaxy was not detected
down to 1.08 mJy (3 sigma), but the depth of the observations and the lens
amplification allow us to improve by approximately one order of magnitude
previously published upper limits on far infrared emission of Lyman-alpha
emitting galaxies at this redshift. The following upper limits are derived from
our observations assuming typical dust parameters: dust mass <5.3x10^7 Msun, IR
luminosity <2.1x10^{11} Lsun, and star formation rate, SFR<35 Msun/yr. The
observed restframe UV--optical--IR spectral energy distribution (SED) of this
galaxy is compatible with that of normal spiral galaxies or blue compact dwarf
galaxies. SEDs of prototypical ULIRGs, such as Arp 220, are clearly excluded.
Finally, we obtain an upper limit of < 2.1x10^{-2} Msun/yr/Mpc^{-3} for the
dust-obscured SFR density of Lyman-alpha selected galaxies at z~6.6.


title:
Substructures in lens galaxies: PG1115+080 and B1555+375, two fold
  configurations

abstract:
  We study the anomalous flux ratio which is observed in some four-image lens
systems, where the source lies close to a fold caustic. In this case two of the
images are close to the critical curve and their flux ratio should be equal to
unity, instead in several cases the observed value differs significantly. The
most plausible solution is to invoke the presence of substructures, as for
instance predicted by the Cold Dark Matter scenario, located near the two
images. In particular, we analyze the two fold lens systems PG1115+080 and
B1555+375, for which there are not yet satisfactory models which explain the
observed anomalous flux ratios. We add to a smooth lens model, which reproduces
well the positions of the images but not the anomalous fluxes, one or two
substructures described as singular isothermal spheres. For PG1115+080 we
consider a smooth model with the influence of the group of galaxies described
by a SIS and a substructure with mass $\sim 10^{5} M_{\odot}$ as well as a
smooth model with an external shear and one substructure with mass $\sim 10^{8}
M_{\odot}$ . For B1555+375 either a strong external shear or two substructures
with mass $\sim 10^{7} M_{\odot}$ reproduce the data quite well.


title: Pulsating travelling fronts: Asymptotics and homogenization regimes

abstract:
  This paper is concerned with some nonlinear propagation phenomena for
reaction-advection-diffusion equations with Kolmogrov-Petrovsky-Piskunov (KPP)
type nonlinearities in general periodic domains or in infinite cylinders with
oscillating boundaries. Having a variational formula for the minimal speed of
propagation involving eigenvalue problems ( proved in Berestycki, Hamel and
Nadirashvili \cite{BHN1}), we consider the minimal speed of propagation as a
function of diffusion factors, reaction factors and periodicity parameters.
There we study the limits, the asymptotic behaviors and the variations of the
considered functions with respect to these parameters. The last section treats
a homogenization problem as an application of the results in the previous
sections in order to find the limit of the minimal speed when the periodicity
cell is very small.


title:
Effect of the long-range interaction in transport through
  one-dimensional nanoparticle arrays

abstract:
  We analyze the effect of the long-range interaction on the transport
properties through ordered and disordered one-dimensional metallic nanoparticle
arrays. We discuss how the threshold voltage, the I-V curves and the voltage
drop through the array are modified as compared to the case in which
interactions are restricted to charges placed on the same island. We show that
some of these modifications are due to finite interactions between charges in
different nanoparticles while other ones are due to interactions between
charges in the islands and those at the electrodes, what produces a
polarization potential drop through the array. We study the screening of the
disorder potential due to charges impurities trapped in the substrate and find
that long-range interactions introduce correlations between the disorder
potentials of neighboring islands.


title:
Tsunami generation by dynamic displacement of sea bed due to dip-slip
  faulting

abstract:
  In classical tsunami-generation techniques, one neglects the dynamic sea bed
displacement resulting from fracturing of a seismic fault. The present study
takes into account these dynamic effects. Earth's crust is assumed to be a
Kelvin-Voigt material. The seismic source is assumed to be a dislocation in a
viscoelastic medium. The fluid motion is described by the classical nonlinear
shallow water equations (NSWE) with time-dependent bathymetry. The
viscoelastodynamic equations are solved by a finite-element method and the NSWE
by a finite-volume scheme. A comparison between static and dynamic
tsunami-generation approaches is performed. The results of the numerical
computations show differences between the two approaches and the dynamic
effects could explain the complicated shapes of tsunami wave trains.

categories: physics.ao-ph physics.comp-ph physics.flu-dyn physics.geo-ph


title: Higgs-Boson Mass Limit within the Randall-Sundrum Model

abstract:
  Perturbative unitarity for $\wlwl$ scattering is discussed within the
Randall-Sundrum model. It is shown that the exchange of massive 4D Kaluza-Klein
gravitons leads to amplitudes growing linearly with the CM energy squared.
Summing over KK gravitons up to a scale $\lbar$ and testing unitarity at
$\rts=\lbar$, one finds that unitarity is violated for $\lbar$ below the 'naive
dimensional analysis' scale, $\lnda$. It is also shown that the exchange of
gravitons can substantially relax the upper limit from unitarity on the mass of
the Standard Model Higgs boson - consistency with unitarity for all $\rts$
below $\lbar$ is possible for $\mh$ as large as $ 1.4\tev$, depending on the
curvature of the background metric. Observation of the mass and width (or cross
section) of one or more KK gravitons at the LHC will directly determine the
curvature and the scale $\lw$ specifying the couplings of matter to the KK
gravitons. With this information and a measurement of the Higgs boson mass it
will be possible to determine the precise $\rts$ value below which unitarity
will remain valid.


title:
Transdet: a matched-filter based algorithm for transit detection -
  application to simulated COROT light curves

abstract:
  We present a matched-filter based algorithm for transit detection and its
application to simulated COROT light curves. This algorithm stems from the work
by Bord\'e, Rouan & L\'eger (2003). We describe the different steps we intend
to take to discriminate between planets and stellar companions using the three
photometric bands provided by COROT. These steps include the search for
secondary transits, the search for ellipsoidal variability, and the study of
transit chromaticity. We also discuss the performance of this approach in the
context of blind tests organized inside the COROT exoplanet consortium.


title: Coherent states and global entanglement in an N qubit system

abstract:
  We consider an $N$ qubit system and show that in the symmetric subspace,
$\mathbb{S}$ a state is not globally entangled, iff it is a coherent state. It
is also proven that in the orthogonal complement $\mathbb{S}_{\bot}$ all states
are globally entangled.


title: Localising the H.E.S.S. Galactic Centre point source

abstract:
  Observations by the H.E.S.S. system of imaging atmospheric Cherenkov
telescopes provide the most sensitive measurements of the Galactic Centre
region in the energy range 150 GeV - 30 TeV. The vicinity of the kinetic centre
of our galaxy harbours numerous objects which could potentially accelerate
particles to very high energies (VHE, > 100 GeV) and thus produce the Gamma-ray
flux observed. Within statistical and systematic errors, the centroid of the
point-like emission measured by H.E.S.S. was found to be in good agreement with
the position of the supermassive black hole Sgr A* and the recently discovered
PWN candidate G359.95-0.04. Given a systematic pointing error of about 30'', a
possible association with the SNR Sgr A East could not be ruled out with the
2004 H.E.S.S. data. In this contribution an update is given on the position of
the H.E.S.S. Galactic Centre source using 2005/2006 data. The systematic
pointing error is reduced to 6'' per axis using guiding telescopes for pointing
corrections, making it possible to exclude with high significance Sgr A East as
the source of the VHE Gamma-Rays.


title: Interaction and ablation of fall-back disks in isolated neutron stars

abstract:
  An analysis of ablation processes is made for a fall-back disk with inner and
outer radii external to the neutron-star light cylinder. The calculated
ablation rate leads, with certain other assumptions, to a simple expression
relating the inner radius and mean mass per unit area of any long-lived
fall-back disk. Expressions for the torque components generated by interaction
with the pulsar wind are obtained. It is not impossible that these could be
responsible for small observable variations in pulse shape and spin-down rate
but they are unlikely to be the source of the periodic changes seen in several
pulsars.


title: The Nature of Running Penumbral Waves Revealed

abstract:
  We seek to clarify the nature of running penumbral (RP) waves: are they
chromospheric trans-sunspot waves or a visual pattern of upward-propagating
waves? Full Stokes spectropolarimetric time series of the photospheric Si I
10827 \AA line and the chromospheric He I 10830 \AA multiplet were inverted
using a Milne-Eddington atmosphere. Spatial pixels were paired between the
outer umbral/inner penumbral photosphere and the penumbral chromosphere using
inclinations retrieved by the inversion and the dual-height pairings of
line-of-sight velocity time series were studied for signatures of wave
propagation using a Fourier phase difference analysis. The dispersion relation
for radiatively cooling acoustic waves, modified to incorporate an inclined
propagation direction, fits well the observed phase differences between the
pairs of photospheric and chromospheric pixels. We have thus demonstrated that
RP waves are in effect low-beta slow-mode waves propagating along the magnetic
field.


title: Compact objects in globular clusters

abstract:
  Globular clusters have long been known to contain large excesses of a variety
of objects formed through dynamical processes. The past few years have seen a
dramatic increase in our knowledge about these systems.


title: The world-sheet description of A and B branes revisited

abstract:
  We give a manifest supersymmetric description of A and B branes on Kahler
manifolds using a completely local N=2 superspace formulation of the
world-sheet nonlinear sigma-model in the presence of a boundary. In particular,
we show that an N=2 superspace description of type A boundaries is possible, at
least when the background is Kahler. This leads to an elegant and concrete
setting for studying coisotropic A branes. Here, apgesan important role is
played by the boundary potential, whose precise physical meaning remains to be
fully understood. Duality transformations relating A and B branes in the
presence of isometries are studied as well.


title:
Hadronic decays of the tau lepton into K K pion modes within Resonance
  Chiral Theory

abstract:
  Tau decays into hadrons have a twofold interest: On the one hand, they are a
clean environment for studying the hadronization of the left-handed current of
QCD, while, on the other side, provide relevant dynamical information of the
resonances that mediate these processes. Within an effective field theory-like
framework, namely Resonance Chiral Theory, we analyse the decays ot the tau
into K K pion modes and compare the results with CLEO and BaBar data. In this
way, we provide bounds on the couplings entering our Lagrangian and predict the
corresponding spectral functions. As a main result -and contrary to the bulk of
theoretical studies and experimental analyses- we find vector current dominance
on these decays.


title: Functorial Cartier duality

abstract:
  In this paper we obtain the Cartier duality for k-schemes of commutative
monoids functorially without providing the vector spaces of functions with a
topology, generalizing a result for finite commutative algebraic groups by M.
Demazure and P. Gabriel.


title:
Construction and analysis of approximate models for electromagnetic
  scattering from imperfectly conducting scatterers

abstract:
  This report is dedicated to the construction and analysis of so-called
Generalized Impedance Boundary Conditions (GIBCs) used in electromagnetic
scattering problems from imperfect conductors as higher order approximations of
a perfect conductor condition. We consider here the 3-D case with Maxwell
equations in a harmonic regime. The construction of GIBCs is based on a scaled
asymptotic expansion with respect to the skin depth. The asymptotic expansion
is theoretically justified at any order and we give explicit expressions till
the third order. These expressions are used to derive the GIBCs. The associated
boundary value problem is analyzed and error estimates are obtained in terms of
the skin depth.


title:
The chemical potential for the inhomogeneous electron liquid in terms of
  its kinetic and potential parts with special consideration of the surface
  pote ntial step and BCS-BEC crossover

abstract:
  The chemical potential $\mu$ of a many-body system is valuable since it
carries fingerprints of phase changes. Here, we summarize results for $\mu$ for
a thre e-dimensional electron liquid in terms of average kinetic and potential
energie s per particle. The difference between $\mu$ and the energy per
particle is fou nd to be exactly the electrostatic potential step at the
surface. We also prese nt calculations for an integrable one-dimensional
many-body system with delta f unction interactions, exhibiting a BCS-BEC
crossover. It is shown that in the B CS regime the chemical potential can be
expressed solely in terms of the ground -state energy per particle. A brief
discussion is also included of the strong c oupling BEC limit.


title: Thermodynamics of Large AdS Black Holes

abstract:
  We consider leading order quantum corrections to the geometry of large AdS
black holes in a spherical reduction of four-dimensional Einstein gravity with
negative cosmological constant. The Hawking temperature grows without bound
with increasing black hole mass, yet the semiclassical back-reaction on the
geometry is relatively mild, indicating that observers in free fall outside a
large AdS black hole never see thermal radiation at the Hawking temperature.
The positive specific heat of large AdS black holes is a statement about the
dual gauge theory rather than an observable property on the gravity side.
Implications for string thermodynamics with an AdS infrared regulator are
briefly discussed.


title: Speckle noise reduction techniques for high-dynamic range imaging

abstract:
  High-dynamic range imaging from space in the visible, aiming in particular at
the detection of terrestrial exoplanets, necessitates not only the use of a
coronagraph, but also of adaptive optics to correct optical defects in real
time. Indeed, these defects scatter light and give birth to speckles in the
image plane. Speckles can be cancelled by driving a deformable mirror to
measure and compensate wavefront aberrations. In a first approach, targeted
speckle nulling, speckles are cancelled iteratively by starting with the
brightest ones. This first method has demonstrated a contrast better than 1e9
in laboratory. In a second approach, zonal speckle nulling, the total energy of
speckles is minimized in a given zone of the image plane. This second method
has the advantage to tackle simultaneously all speckles from the targeted zone,
but it still needs better experimental demonstration.


title: Staggered-Vortex Superfluid of Ultracold Bosons in an Optical Lattice

abstract:
  We show that the dynamics of cold bosonic atoms in a two-dimensional square
optical lattice produced by a bichromatic light-shift potential is described by
a Bose-Hubbard model with an additional effective staggered magnetic field. In
addition to the known uniform superfluid and Mott insulating phases, the
zero-temperature phase diagram exhibits a novel kind of finite-momentum
superfluid phase, characterized by a quantized staggered rotational flux. An
extension for fermionic atoms leads to an anisotropic Dirac spectrum, which is
relevant to graphene and high-$T_c$ superconductors.


title: On O^*-representability and C^*-representability of *-algebras

abstract:
  Characterization of the *-subalgebras in the algebra of bounded operators
acting on Hilbert space is presented. Sufficient conditions for the existence
of a faithful representation in pre-Hilbert space of a *-algebra in terms of
its Groebner basis are given. These conditions are generalization of the
unshrinkability of monomial *-algebras introduced by C. Lance and P. Tapper.
The applications to *-doubles, monomial *-algebras and several other classes of
*-algebras are presented.


title: Leptonic decays of the eta meson with the WASA detector at CELSIUS

abstract:
  Decay channels of the eta meson with at least one lepton pair in the final
state are discussed. Preliminary results on electron-positron pair production
from the pd->He eta reaction from the WASA experiment at CELSIUS are presented.


title:
Slit and integral-field optical spectroscopy of the enigmatic quasar
  HE0450-2958

abstract:
  Interest in the quasar HE0450-2958 arose following the publication of the
non-detection of its expected massive host, leading to various interpretations.
This article investigates the gaseous and stellar contents of the system
through additional VLT/FORS slit spectra and integral field spectroscopy from
VLT/VIMOS. We apply our MCS deconvolution algorithm on slit spectra for the
separation of the QSO and diffuse components, and develop a new method to
remove the point sources in Integral Field Spectra, allowing extraction of
velocity maps, narrow-line images, spatially resolved spectra or ionization
diagrams of the surroundings of HE0450-2958. The whole system is embedded in
gas, mostly ionized by the QSO radiation field and shocks associated with radio
jets. The observed gas and star dynamics are unrelated, revealing a strongly
perturbed system. Despite longer spectroscopic observations, the host galaxy
remains undetected.


title: Combined Electroweak Analysis

abstract:
  Recent developments in the measurement of precision electroweak measurements
are summarised, notably new results on the mass of the top quark and mass and
width of the W boson. Predictions of the Standard Model are compared to the
experimental results which are used to constrain the input parameters of the
Standard Model, in particular the mass of the Higgs boson. The agreement
between measurements and expectations from theory is discussed.
  Invited talk presented at the EPS HEP 2007 conference
  Manchester, England, July 19th to 25th, 2007


title: Remarks on "Resolving isospectral `drums' by counting nodal domains"

abstract:
  In [3] the authors studied the 4-parameter family of isospectral flat 4-tori
T^\pm(a,b,c,d) discovered by Conway and Sloane. With a particular method of
counting nodal domains they were able to distinguish these tori (numerically)
by computing the corresponding nodal sequences relative to a few explicit
tuples (a,b,c,d). In this note we confirm the expectation expressed in [3] by
proving analytically that their nodal count distinguishes any 4-tuple of
distinct positive real numbers.


title: The enigma of the oldest `nova': the central star and nebula of CK Vul

abstract:
  CK Vul is classified as, amongst others, the slowest known nova, a
hibernating nova, or a very late thermal pulse object. Following its eruption
in AD 1670, the star remained visible for 2 years. A 15-arcsec nebula was
discovered in the 1980's, but the star itself has not been detected since the
eruption. We here present radio images which reveal an 0.1-arcsec radio source
with a flux of 1.5 mJy at 5 GHz. Deep Halpha images show a bipolar nebula with
a longest extension of 70 arcsec, with the previously known compact nebula at
its waist. The emission-line ratios show that the gas is shock-ionized, at
velocities >100 km/s. Dust emission yields an envelope mass of ~0.05 Msun.
Echelle spectra indicate outflow velocities up to 360 km/s. From a comparison
of images obtained in 1991 and 2004 we find evidence for expansion of the
nebula, consistent with an origin in the 1670 explosion; the measured expansion
is centred on the radio source. No optical or infrared counterpart is found at
the position of the radio source. The radio emission is interpreted as thermal
free-free emission from gas with Tel ~ 10000 K. The radio source may be due to
a remnant circumbinary disk, similar to those seen in some binary post-AGB
stars. We discuss possible classifications of this unique outburst, including
that of a sub-Chandrasekhar mass supernova, a nova eruption on a cool, low-mass
white dwarf, or a thermal pulse induced by accretion from a circumbinary disk.


title: M31 Transverse Velocity and Local Group Mass from Satellite Kinematics

abstract:
  We present several different statistical methods to determine the transverse
velocity vector of M31. The underlying assumptions are that the M31 satellites
on average follow the motion of M31 through space, and that the galaxies in the
outer parts of the Local Group on average follow the motion of the Local Group
barycenter through space. We apply the methods to the line-of-sight velocities
of 17 M31 satellites, to the proper motions of the 2 satellites M33 and IC 10,
and to the line-of-sight velocities of 5 galaxies near the Local Group turn
around radius, respectively. This yields 4 independent but mutually consistent
determinations of the heliocentric M31 transverse velocities in the West and
North directions, with weighted averages <v_W> = -78+/-41 km/s and <v_N> =
-38+/-34 km/s. The Galactocentric tangential velocity of M31 is 42 km/s, with
1-sigma confidence interval V_tan <= 56 km/s. The implied M31-Milky Way orbit
is bound if the total Local Group mass M exceeds 1.72^{+0.26}_{-0.25}x10^{12}
solar masses. If indeed bound, then the timing argument combined with the known
age of the Universe implies that M = 5.58^{+0.85}_{-0.72}x10^{12} solar masses.
This is on the high end of the allowed mass range suggested by cosmologically
motivated models for the individual structure and dynamics of M31 and the Milky
Way, respectively. It is therefore possible that the timing mass is an
overestimate of the true mass, especially if one takes into account recent
results from the Millennium Simulation that show that there is also a
theoretical uncertainty of 41 percent (Gaussian dispersion) in timing mass
estimates. The M31 transverse velocity implies that M33 is in a tightly bound
orbit around M31. This may have led to some tidal deformation of M33. It will
be worthwhile to search for observational evidence of this.


title:
The nature of hypervelocity stars as inferred from their galactic
  trajectories

abstract:
  We have computed the galactic trajectories of twelve hypervelocity stars
(HVSs) under the assumption that they originated in the Galactic Centre. We
show that eight of these twelve stars are bound to the Galaxy. We consider the
subsequent trajectories of the bound stars to compute their characteristic
orbital period, which is 2 Gyr. All eight bound stars are moving away from the
centre of the Galaxy, which implies that the stars' lifetimes are less than 2
Gyr. We thus infer that the observed HVSs are massive main sequence stars,
rather than blue horizontal branch stars. The observations suggest that blue
HVSs are ejected from the Galactic Centre roughly every 15 Myr. This is
consistent with the observed population of blue stars in extremely tight orbits
round the central super-massive black hole (SMBH), the so-called S-stars, if we
assume that the HVSs are produced by the breakup of binaries. One of the stars
in such a binary is ejected at high velocities to form a HVS; the other remains
bound to the SMBH as an S-star.
  We further show that the one high-velocity system observed to be moving
towards the Galactic Centre, SDSS J172226.55+594155.9, could not have
originated in the Galactic Centre; rather, we identify it as a halo object.


title:
Recent advances in the three flavor Larkin-Ovchinnikov-Fulde-Ferrel
  phase of QCD

abstract:
  We present a summary of the recent advances achieved in the study of three
flavor Larkin-Ovchinnikov-Fulde-Ferrell (LOFF)phase of QCD. We have explored,
using a Ginzburg-Landau expansion of the free energy, the LOFF phase with three
flavors, in the simplest single plane wave structure, using the NJL
four-fermion coupling. We have found that this phase does not suffer the
chromo-magnetic instability problem. A preliminary study of astrophysical
effects of quark matter in the aforementioned phase has been done and we have
evaluated self-consistently the strange quark mass extending the pairing ansatz
to the CubeX and 2Cube45z structure. Finally we have investigated the
possibility of Goldstone bosons condensation in the favored cubic structures of
LOFF phase.


title: Design and Implementation of the New D0 Level-1 Calorimeter Trigger

abstract:
  Increasing luminosity at the Fermilab Tevatron collider has led the D0
collaboration to make improvements to its detector beyond those already in
place for Run IIa, which began in March 2001. One of the cornerstones of this
Run IIb upgrade is a completely redesigned level-1 calorimeter trigger system.
The new system employs novel architecture and algorithms to retain high
efficiency for interesting events while substantially increasing rejection of
background. We describe the design and implementation of the new level-1
calorimeter trigger hardware and discuss its performance during Run IIb data
taking. In addition to strengthening the physics capabilities of D0, this
trigger system will provide valuable insight into the operation of analogous
devices to be used at LHC experiments.


title:
Non-equilibrium hydrogen ionization in 2D simulations of the solar
  atmosphere

abstract:
  The ionization of hydrogen in the solar chromosphere and transition region
does not obey LTE or instantaneous statistical equilibrium because the
timescale is long compared with important hydrodynamical timescales, especially
of magneto-acoustic shocks. We implement an algorithm to compute
non-equilibrium hydrogen ionization and its coupling into the MHD equations
within an existing radiation MHD code, and perform a two-dimensional simulation
of the solar atmosphere from the convection zone to the corona. Analysis of the
simulation results and comparison to a companion simulation assuming LTE shows
that: a) Non-equilibrium computation delivers much smaller variations of the
chromospheric hydrogen ionization than for LTE. The ionization is smaller
within shocks but subsequently remains high in the cool intershock phases. As a
result, the chromospheric temperature variations are much larger than for LTE
because in non-equilibrium, hydrogen ionization is a less effective internal
energy buffer. The actual shock temperatures are therefore higher and the
intershock temperatures lower. b) The chromospheric populations of the hydrogen
n = 2 level, which governs the opacity of Halpha, are coupled to the ion
populations. They are set by the high temperature in shocks and subsequently
remain high in the cool intershock phases. c) The temperature structure and the
hydrogen level populations differ much between the chromosphere above
photospheric magnetic elements and above quiet internetwork. d) The hydrogen n
= 2 population and column density are persistently high in dynamic fibrils,
suggesting that these obtain their visibility from being optically thick in
Halpha also at low temperature.


title:
The Homogeneous Approximation Property and the Comparison Theorem for
  Coherent Frames

abstract:
  We show that the homogeneous approximation property and the comparison
theorem hold for arbitrary coherent frames. This observation answers some
questions about the density of frames that are not covered by the theory of
Balan, Casazza, Heil, and Landau. The proofs are a variation of the method
developed by Ramanathan and Steger.


title: On Real-Time Communication Systems with Noisy Feedback

abstract:
  We consider a real-time communication system with noisy feedback consisting
of a Markov source, a forward and a backward discrete memoryless channels, and
a receiver with finite memory. The objective is to design an optimal
communication strategy (that is, encoding, decoding, and memory update
strategies) to minimize the total expected distortion over a finite horizon. We
present a sequential decomposition for the problem, which results in a set of
nested optimality equations to determine optimal communication strategies. This
provides a systematic methodology to determine globally optimal joint
source-channel encoding and decoding strategies for real-time communication
systems with noisy feedback.


title:
Numerical simulations of type III planetary migration: II. Inward
  migration of massive planets

abstract:
  We present a numerical study of rapid, so called type III migration for
Jupitersized planets embedded in a protoplanetary disc. We limit ourselves to
the case of inward migration, and study in detail its evolution and physics,
concentrating on the structure of the corotation and circumplanetary regions,
and processes for stopping migration. We also consider the dependence of the
migration behaviour on several key parameters. We perform this study using the
results of global, two-dimensional hydrodynamical simulations with adaptive
mesh refinement. The initial conditions are chosen to satisfy the condition for
rapid inward migration. We find that type III migration can be divided into two
regimes, fast and slow. The structure of the coorbital region, mass
accumulation rate, and migration behaviour differ between these two regimes.
All our simulations show a transition from the fast to the slow regime, ending
type III migration well before reaching the star. The stopping radius is found
to be larger for more massive planets and less massive discs. A sharp density
drop is also found to be an efficient stopping mechanism. In the fast migration
limit the migration rate and induced eccentricity are lower for less massive
discs, but almost do not depend on planet mass. Eccentricity is damped on the
migration time scale.


title: An elementary trigonometric equation

abstract:
  A systematic study of the trigonometric equation A tan a + B sin b = C, where
A, B and C^2 are rational numbers. The special case tan Pi/11 + 4 sin 3 Pi/11 =
sqrt[11] appears in the classical literature.


title:
The Time Response of Glass Resistive Plate Chambers to Heavily Ionizing
  Particles

abstract:
  The HARP system of resistive plate chambers (RPCs) was designed to perform
particle identification by the measurement of the difference in the
time-of-flight of different particles. In previous papers an apparent
discrepancy was shown between the response of the RPCs to minimum ionizing
pions and heavily ionizing protons. Using the kinematics of elastic scattering
off a hydrogen target a controlled beam of low momentum recoil protons was
directed onto the chambers. With this method the trajectory and momentum, and
hence the time-of-flight of the protons can be precisely predicted without need
for a measurement of momentum of the protons. It is demonstrated that the
measurement of the time-of-arrival of particles by the thin gas-gap glass RPC
system of the HARP experiment depends on the primary ionization deposited by
the particle in the detector.


title: Spinflation and cycling branes in warped throats

abstract:
  The implications of brane motion in angular directions of Calabi-Yau flux
compactifications are discussed from the point of view of an observer living on
the worldvolume of the brane and from the point of view of an observer living
elsewhere in the three non-compact dimensions. The brane observer can
experience cosmological bounces and cyclic behavior of the scale factor induced
by centrifugal angular momentum barriers. Observers living elsewhere in the
compactification experience marginally prolonged periods of inflation due to
large angular momentum (spinflation). The presence of spinflaton fields (or
other fields with non-standard kinetic terms) during inflation may lead to
interesting observational signatures in the cosmic microwave background
radiation.


title: Brane inflation and the WMAP data: a Bayesian analysis

abstract:
  The Wilkinson Microwave Anisotropy Probe (WMAP) constraints on string
inspired ''brane inflation'' are investigated. Here, the inflaton field is
interpreted as the distance between two branes placed in a flux-enriched
background geometry and has a Dirac-Born-Infeld (DBI) kinetic term. Our method
relies on an exact numerical integration of the inflationary power spectra
coupled to a Markov-Chain Monte-Carlo exploration of the parameter space. This
analysis is valid for any perturbative value of the string coupling constant
and of the string length, and includes a phenomenological modelling of the
reheating era to describe the post-inflationary evolution. It is found that the
data favour a scenario where inflation stops by violation of the slow-roll
conditions well before brane annihilation, rather than by tachyonic
instability. Concerning the background geometry, it is established that log(v)
> -10 at 95% confidence level (CL), where "v" is the dimensionless ratio of the
five-dimensional sub-manifold at the base of the six-dimensional warped
conifold geometry to the volume of the unit five-sphere. The reheating energy
scale remains poorly constrained, Treh > 20 GeV at 95% CL, for an extreme
equation of state (wreh ~ -1/3) only. Assuming the string length is known, the
favoured values of the string coupling and of the Ramond-Ramond total
background charge appear to be correlated. Finally, the stochastic regime
(without and with volume effects) is studied using a perturbative treatment of
the Langevin equation. The validity of such an approximate scheme is discussed
and shown to be too limited for a full characterisation of the quantum effects.


title: Membrane adhesion and domain formation

abstract:
  We review theoretical results for the adhesion-induced phase behavior of
biomembranes. The focus is on models in which the membranes are represented as
discretized elastic sheets with embedded adhesion molecules. We present several
mechanism that lead to the formation of domains during adhesion, and discuss
the time-dependent evolution of domain patterns obtained in Monte-Carlo
simulations. The simulated pattern dynamics has striking similarities to the
pattern evolution observed during T cell adhesion.


title: Ultrahigh energy neutrinos with a mediterranean neutrino telescope

abstract:
  A study of the ultra high energy neutrino detection performances of a km^3
Neutrino Telescope sitting at the three proposed sites for "ANTARES", "NEMO"
and "NESTOR" in the Mediterranean sea is here performed. The detected charged
leptons energy spectra, entangled with their arrival directions, provide an
unique tool to both determine the neutrino flux and the neutrino-nucleon cross
section.


title: NGC 5253 and ESO 269-G058: Dwarf Galaxies with a Past

abstract:
  Deep r' and i' images obtained with GMOS on Gemini South are used to probe
the bright stellar content in the outer regions of NGC 5253 and ESO269-G058.
Red giant branch (RGB) stars are traced out to a distance of 8 kpc along the
major axis of NGC 5253, and 6 kpc in ESO269-G058. The outer regions of both
galaxies are metal-poor; RGB stars located between projected major axis
distances of 2 and 4 kpc in NGC 5253 have [Fe/H] ~ -1, whereas RGB stars in the
corresponding portion of ESO269-G058 have [Fe/H] ~ -1.8. Stars with
metallicities that differ from the mean by more than a few tenths of a dex make
only a modest contribution to the stellar content in the outer regions of both
galaxies. A population of bright asymptotic giant branch (AGB) stars is seen in
both galaxies. Roughly 1 - 10% of the stellar mass of NGC 5253 may have formed
during the past few hundred million years, and it is suggested that the
progenitors of the two recent SN Ia in this galaxy may have formed at this
time. It is argued that the current episodes of star formation in NGC 5253 and
ESO269-G058 may have been triggered up to ~ 1 Gyr in the past. Finally, a
distance modulus is computed for each galaxy based on the brightness of the
RGB-tip, and the results are 27.48 +/- 0.14 for NGC 5253, and 27.93 +/- 0.18
for ESO269-G058.


title:
The ACS Survey of Galactic Globular Clusters. III. The Double Subgiant
  Branch of NGC 1851

abstract:
  Photometry with HST's ACS reveals that the subgiant branch (SGB) of the
globular cluster NGC 1851 splits into two well-defined branches. If the split
is due only to an age effect, the two SGBs would imply two star formation
episodes separated by $\sim$ 1 Gyr. We discuss other anomalies in NGC 1851
which could be interpreted in terms of a double stellar population. Finally, we
compare the case of NGC 1851 with the other two globulars known to host
multiple stellar populations, and show that all three clusters differ in
several important respects.


abstract:
  The MAGIC Project: Contributions to ICRC 2007, Merida, Mexico. Contents pages
for the Contribution on behalf of the MAGIC Collaboration to the 30th ICRC that
took place in July 2007 in Merida, Mexico. The contents are in html form with
clickable links to the papers that exist on the Astrophysics archive. We hope
that this will make it easier to access the output of the conference in a
systematic way. Comments on how useful this is/ how it could be improved should
be sent to michela.demaria@iuav.it.


title: Chen's double sieve, Goldbach's conjecture and the twin prime problem, 2

abstract:
  For every even integer N, denote by D_{1,2}(N) the number of representations
of N as a sum of a prime and an integer having at most two prime factors. In
this paper, we give a new lower bound for D_{1,2}(N).


title: 1953: An unrecognized summit in human genetic linkage analysis

abstract:
  This paper summarizes and discusses the methodological research in human
genetic linkage analysis, leading up to and following from the paper of C. A.
B. Smith presented as a Royal Statistical Society discussion paper in 1953.
This paper was given as the Fisher XXVII Memorial Lecture, in Cambridge,
December 4, 2006.


title: Entanglement detection beyond the cross-norm or realignment criterion

abstract:
  Separability problem, to decide whether a given state is entangled or not, is
a fundamental problem in quantum information theory. We propose a powerful and
computationally simple separability criterion, which allows us to detect the
entanglement of many bound entangled states. The criterion is strictly stronger
than the dV criterion, the computable cross-norm or realignment criterion and
its optimal nonlinear entanglement witnesses. Furthermore, this criterion can
be generalized to an analogue of permutation separability criteria in the
even-partite systems.


title: Consequences of Approximate $S_3$ Symmetry of the Neutrino Mass Matrix

abstract:
  Assuming that the neutrino mass matrix is dominated by a term with the
permutation symmetry $S_{\scriptscriptstyle 3}$ it is possible to explain
neutrino data only if the masses are quasi-degenerate. A sub-dominant term with
an approximate $\mu -\tau$ symmetry leads to an approximate tri-bimaximal form.
Experimental consequences are discussed.


title: Thermalisation by a boson bath in a pure state

abstract:
  We consider a quantum system weakly coupled to a large heat bath of harmonic
oscillators. It is well known that such a boson bath initially at thermal
equilibrium thermalises the system. We show that assuming a priori an
equilibrium state is not necessary to obtain the thermalisation of the system.
We determine the complete Schr\"odinger time evolution of the subsystem of
interest for an initial pure product state of the composite system consisting
of the considered system and the bath. We find that the system relaxes into
canonical equilibrium for almost all initial pure bath states of
macroscopically well-defined energy. The temperature of the system asymptotic
thermal state is determined by the energy of the initial bath state as the
corresponding microcanonical temperature. Moreover, the time evolution of the
system is identical to the one obtained assuming that the boson bath is
initially at thermal equilibrium with this temperature. A significant part of
our approach is applicable to other baths and we identify the bath features
which are requisite for the thermalisation studied.


title:
On the nature of the z=0 X-ray absorbers: II. The contrast between local
  and AGN host galaxy absorption

abstract:
  We search for highly-ionized gas near three AGN host galaxies using the
Chandra low-energy transmission grating spectrograph. Strong absorption lines
from such gas are seen at z=0, most likely from one or more of the following
components: (1) a Galactic corona, (2) the Local Group medium, and (3) an
extended warm-hot intergalactic medium (WHIM) filament passing through our
local overdensity. Since AGNs reside within host galaxies that are also
expected to sit within cosmically overdense regions, similar absorption
resulting from these three components should appear at the AGN redshifts as
well. However, no such absorption is seen. The lack of strong absorption lines
is likely a result of the gas in these host galaxies and surrounding galaxy
clusters being much hotter, and hence more highly ionized, than the gas in the
Local Group+Galaxy system. We conclude that WHIM filaments produce no
measurable absorption lines at the AGN redshifts, and therefore contribute at
most a small fraction of the observed z=0 warm-hot gas.