title:
The Behavior of Laplace Transform of the Invariant Measure on the
  Hypersphere of High Dimension

abstract:
  We consider the sequence of the hyperspheres $M_{n,r}$ i.e. the homogeneous
transitive spaces - of the Cartan subgroup $SDiag(n,\Bbb R)$ of the group
$SL(n,\Bbb R), n=1 ...$, and studied the normalized limit of the corresponding
sequence of the invariant measures $m_n$ on those spaces. In the case of
compact groups and homogeneous spaces, as example - for classical pairs
$(SO(n), S^{n-1}), n=1 ...$ - the limit of corresponding measures is the
classical infinite dimensional gaussian measure - this is well-known
Maxwell-Poincare lemma. Simultaneously that Gaussian measure is a unique (up to
scalar) invariant measure with respect to the action of infinite orthogonal
group $O(\infty)$. This coincidences means the asymptotic equivalence between
grand and small canonical ensembles for the series of the pairs $(SO(n),
S^{n-1})$. Our main result shows that situation for noncompact groups, for
example for the case $(SDiag(n,\Bbb R),M_{n,r})$ (the definitions see below),
is completely different: the limit of measures $m_n $ does not exist in literal
sense, and we show that only normalized logarithmic limit of the Laplace
transform of those measures does exist. In the same time there exists the
measure which is invariant measure with respect to continuous analogue of
Cartan subgroup of the group $GL(\infty)$ - this is so called infinite
dimensional Lebesgue (see \cite{V}). This difference is an evidence of the
non-equivalence between the grand and small canonical ensembles for the
noncompact case.


title: Fabrication of Graphene p-n-p Junctions with Contactless Top Gates

abstract:
  We developed a multi-level lithography process to fabricate graphene p-n-p
junctions with the novel geometry of contactless, suspended top gates. This
fabrication procedure minimizes damage or doping to the single atomic layer,
which is only exposed to conventional resists and developers. The process does
not require special equipment for depositing gate dielectrics or releasing
sacrificial layers, and is compatible with annealing procedures that improve
device mobility. Using this technique, we fabricate graphene devices with
suspended local top gates, where the creation of high quality graphene p-n-p
junctions is confirmed by transport data at zero and high magnetic fields.


title:
Big bang nucleosynthesis constrains the total annihilation cross section
  of neutralino dark matter

abstract:
  Assuming the lightest neutralino forms dark matter, we study its residual
annihilation after freeze-out at the early universe. If taking place after the
big bang nucleosynthesis (BBN) the annihilation products, especially at the
hadronic modes, may cause nonthermal nuclear reaction and change the prediction
of the primordial abundance of light elements in the standard BBN scenario. We
therefore put constraints on the neutralino annihilation cross section. These
constraints are free of the uncertainties of the dark matter profile today
suffered by direct or indirect detection of dark matter. We find the
constraints by BBN is important, especially when taking large $\tan\beta$. If
the light element abundances can be determined with higher precision in the
future the constraint will become very strong, so that a majority of the
parameter space allowed by the relic density requirement may be excluded.


title: Photon correlation in GaAs self-assembled quantum dots

abstract:
  We report on photon coincidence measurement in a single GaAs self-assembled
quantum dot (QD) using a pulsed excitation light source. At low excitation,
when a neutral exciton line was present in the photoluminescence (PL) spectrum,
we observed nearly perfect single photon emission from an isolated QD at 670 nm
wavelength. For higher excitation, multiple PL lines appeared on the spectra,
reflecting the formation of exciton complexes. Cross-correlation functions
between these lines showed either bunching or antibunching behavior, depending
on whether the relevant emission was from a biexciton cascade or a charged
exciton recombination.


title:
Preparation of a Stable and Maximally Entangled State of Two Distant
  Qutrits Trapped in Separate Cavities

abstract:
  We have proposed a simple scheme to entangle two distant qutrits trapped in
separate optical cavities. The quantum information of each qutrit is skillfully
encoded on the degenerate ground states of a pair of atoms, hence the
entanglement between them is relatively stable against spontaneous emission. In
Lamb-Dicke limits, it is not necessary to require coincidence detections, which
will relax the conditions for the experimental realization. The scheme is
robust against the inefficient detections.


title: Construction of quantized enveloping algebras by cocycle deformation

abstract:
  By using cocycle deformation, we construct a certain class of Hopf algebras,
containing the quantized enveloping algebras and their analogues, from what we
call pre-Nichols algebras. Our construction generalizes in some sense the known
construction by (generalized) quantum doubles, but unlike in the known
situation, it saves us from difficulties in checking complicated defining
relations.


title: Quantum Gravity without General Relativity

abstract:
  The quantum field theory of gravitation is constructed in terms of Lagrangian
density of Dirac fields which couple to the electromagnetic field $A_\mu$ as
well as the gravitational field $\cal G$. The gravity appears in the mass term
as $ m(1+g {\cal G}) \bar{\psi}\psi $ with the coupling constant of $g$. In
addition to the gravitational force between fermions, the electromagnetic field
$A_\mu$ interacts with the gravity as the fourth order effects and its strength
amounts to $\alpha$ times the gravitational force. Therefore, the interaction
of photon with gravity is not originated from Einstein's general relativity
which is entirely dependent on the unphysical assumption of the principle of
equivalence. Further, we present a renormalization scheme for the gravity and
show that the graviton stays massless.


title: Mass-Deformed Bagger-Lambert Theory and its BPS Objects

abstract:
  We find a sixteen supersymmetric mass-deformed Bagger-Lambert theory with
$SO(4)\times SO(4)$ global R-symmetry. The R-charge plays the `non-central'
term in the superalgebra. This theory has one symmetric vacuum and two
in-equivalent broken sectors of vacua. Each sector of the broken symmetry has
the SO(4) geometry. We find the 1/2 BPS domain walls connecting the symmetric
phase and any broken phase, and 1/4 BPS supertube-like objects, which may
appear as anyonic q-balls in the symmetric phase or vortices in the broken
phase. We also discuss mass deformations which reduces the number of
supersymmetries.


title: Topology of Chaotic Mixing Patterns

abstract:
  A stirring device consisting of a periodic motion of rods induces a mapping
of the fluid domain to itself, which can be regarded as a homeomorphism of a
punctured surface. Having the rods undergo a topologically-complex motion
guarantees at least a minimum amount of stretching of material lines, which is
important for chaotic mixing. We use topological considerations to describe the
nature of the injection of unmixed material into a central mixing region, which
takes place at injection cusps. A topological index formula allow us to predict
the possible types of unstable foliations that can arise for a fixed number of
rods.


title: Scalar order: possible candidate for order parameters in skutterudites

abstract:
  Phenomenological Landau analysis shows that the properties of ordered phases
in some skutterudites are consistently accounted for by a scalar order
parameter which preserves the cubic symmetry, even in the ordered phase. A
universal value is found for the anisotropy ratio of the transition temperature
in a magnetic field, homogeneous magnetization, and induced staggered
magnetization. The difference in magnetic behavior between PrFe$_4$P$_{12}$ and
PrRu$_4$P$_{12}$ near their phase transitions is explained within a single
framework. For the low-field phase of PrFe$_4$P$_{12}$, the scalar order with
the $\Gamma_{1g}$ symmetry can explain (i) the absence of field induced dipoles
perpendicular to the magnetic field, (ii) isotropic magnetic susceptibility in
the ordered phase, (iii) the field angle dependence of the transition
temperature, and (iv) the splitting pattern of the $^{31}$P nuclear magnetic
resonance (NMR) spectra. It is proposed how the order parameter in
SmRu$_4$P$_{12}$ is identified by NMR analysis of a single crystal.


title: Statistics, ethics, and probiotica

abstract:
  A randomized clinical trial comparing an experimental new treatment to a
standard therapy for a life-threatening medical condition should be stopped
early on ethical grounds, in either of the following scenarios: (1) it has
become overwhelmingly clear that the new treatment is better than the standard;
(2) it has become overwhelmingly clear that the trial is not going to show that
the new treatment is any better than the standard. The trial is continued in
the third scenario: (3) there is a reasonable chance that the new treatment
will finally turn out to be better than the standard, but we aren't sure yet.
  However, the (blinded) data monitoring committee in the "PROPATRIA" trial of
an experimental probiotica treatment for patients with acute pancreatitis
allowed the trial to continue at the half way interim analysis, in effect
because there was still a good chance of proving that the probiotica treatment
was very harmful to their patients. The committee did not know whether
treatment A was the probiotica treatment or the placebo. In itself this should
not have caused a problem, since it could easily have determined the
appropriate decision under both scenarios. Were the decisions in the two
scenarios different, then the data would have to be de-blinded, in order to
determine the appropriate decision. The committee mis-read the output of SPSS,
which reports the smaller of two one-sided p-values, without informing the user
what it is doing. It seems that about 5 lives were sacrificed to the chance of
getting a significant result that the probiotica treatment was bad for the
patients in the trial.


title:
Phenomenological theory of a scalar electronic order: application to
  skutterudite PrFe4P12

abstract:
  By phenomenological Landau analysis, it is shown that a scalar order
parameter with the point-group symmetry $\Gamma_{1g}$ explains most properties
associated with the phase transition in PrFe$_4$P$_{12}$ at 6.5 K. The
scalar-order model reproduces magnetic and elastic properties in
PrFe$_4$P$_{12}$ consistently such as (i) the anomaly of the magnetic
susceptibility and elastic constant at the transition temperature, (ii)
anisotropy of the magnetic susceptibility in the presence of uniaxial pressure,
and (iii) the anomaly in the elastic constant in magnetic field. An Ehrenfest
relation is derived which relates the anomaly of the magnetic susceptibility to
that of the elastic constant at the transition.


title:
Finite-dimensional representation of the quadratic algebra of a
  generalized coagulation-decoagulation model

abstract:
  The steady-state of a generalized coagulation-decoagulation model on a
one-dimensional lattice with reflecting boundaries is studied using a
matrix-product approach. It is shown that the quadratic algebra of the model
has a four-dimensional representation provided that some constraints on the
microscopic reaction rates are fulfilled. The dynamics of a product shock
measure with two shock fronts, generated by the Hamiltonian of this model, is
also studied. It turns out that the shock fronts move on the lattice as two
simple random walkers which repel each other provided that the same constraints
on the microscopic reaction rates are satisfied.


title:
Dynamic Programming based Time-Delay Estimation (TDE) Technique for
  Analysis of Time-varying Time-delay

abstract:
  A new time-delay estimation (TDE) technique based on dynamic programming is
developed, to measures the time-varying time-delay between two signals. Dynamic
programming based TDE technique provides a frequency response 5 to 10 times
higher than previously known TDE techniques, namely those based on time-lag
cross-correlation or wavelet analysis. Effects of frequency spectrum,
signal-to-noise ratio and amplitude of time-delay on response (represented as
transfer function) of TDE technique is studied using simulated data signals.
Transfer function for the technique decreases with increase in noise in signal;
however it is independent of signal spectrum shape. Dynamic programming based
TDE technique is applied to the Beam-Emission-Spectroscopy (BES) diagnostic
data to measure poloidal velocity fluctuations, which led to the observation of
theoretically predicted zonal flows in high-temperature tokamak plasmas.


title:
MAGIC J0616+225 as delayed TeV emission of cosmic-rays diffusing from
  SNR IC 443

abstract:
  We present a theoretical model that explains the high energy phenomenology of
the neighborhood of SNR IC 443, as observed with the Major Atmospheric Gamma
Imaging Cherenkov (MAGIC) telescope and the Energetic Gamma-Ray Experiment
Telescope (EGRET). We interpret MAGIC J0616+225 as delayed TeV emission of
cosmic-rays diffusing from IC 443 and interacting with a known cloud located at
a distance of about 20 pc in the foreground of the remnant. This scenario
naturally explains the displacement between EGRET and MAGIC sources, their
fluxes, and their spectra. We compare this model with others recently
presented, and discuss how it can be tested with observations by the Gamma-ray
Large Area Telescope (GLAST).


title:
Spin-dependent empirical formula for the lowest excitation energies of
  the natural parity states in even-even nuclei

abstract:
  We present an empirical expression which holds for the lowest excitation
energy of the natural parity states in even-even nuclei throughout the entire
periodic table. This formula contains spin-dependent factors so that it is
applied to different multipole states with the same model parameters in
contrast to the recently proposed empirical expression where the model
parameters had to be fitted for each multipole separately.


title:
Error bounds on the non-normal approximation of Hermite power variations
  of fractional Brownian motion

abstract:
  Let $q\geq 2$ be a positive integer, $B$ be a fractional Brownian motion with
Hurst index $H\in(0,1)$, $Z$ be an Hermite random variable of index $q$, and
$H_q$ denote the Hermite polynomial having degree $q$. For any $n\geq 1$, set
$V_n=\sum_{k=0}^{n-1} H_q(B_{k+1}-B_k)$. The aim of the current paper is to
derive, in the case when the Hurst index verifies $H>1-1/(2q)$, an upper bound
for the total variation distance between the laws $\mathscr{L}(Z_n)$ and
$\mathscr{L}(Z)$, where $Z_n$ stands for the correct renormalization of $V_n$
which converges in distribution towards $Z$. Our results should be compared
with those obtained recently by Nourdin and Peccati (2007) in the case when
$H<1-1/(2q)$, corresponding to the situation where one has normal
approximation.


title:
Suzaku observation of TeV blazar the 1ES 1218+304: clues on particle
  acceleration in an extreme TeV blazar

abstract:
  We observed the TeV blazar 1ES 1218+304 with the X-ray astronomy satellite
Suzaku in May 2006. At the beginning of the two-day continuous observation, we
detected a large flare in which the 5-10 keV flux changed by a factor of ~2 on
a timescale of 5x10^4 s. During the flare, the increase in the hard X-ray flux
clearly lagged behind that observed in the soft X-rays, with the maximum lag of
2.3x10^4 s observed between the 0.3-1 keV and 5-10 keV bands. Furthermore we
discovered that the temporal profile of the flare clearly changes with energy,
being more symmetric at higher energies. From the spectral fitting of
multi-wavelength data assuming a one-zone, homogeneous synchrotron self-Compton
model, we obtain B~0.047 G, emission region size R = 3.0x10^16 cm for an
appropriate beaming with a Doppler factor of delta = 20. This value of B is in
good agreement with an independent estimate through the model fit to the
observed time lag ascribing the energy-dependent variability to differential
acceleration timescale of relativistic electrons provided that the gyro-factor
\xi is 10^5.


title: S-wave \gamma\gamma\to \pi\pi and f_0(980)\to \pi\pi

abstract:
  We report on a dispersion relation for the \gamma\gamma\to (\pi\pi)_I S-wave
in isospin I emphasizing the low energy region. The f_0(980) signal that
emerges in \gamma\gamma\to \pi\pi is also discussed. Our results could be used
to distinguish between different \pi\pi isoscalar S-wave parameterizations. We
also calculate the width of the \sigma resonance to \gamma\gamma and obtain the
value \Gamma(\sigma\to\gamma\gamma)=(1.68\pm 0.15) KeV. Finally, we elaborate
on the size of the f_0(980) coupling to \pi\pi and show that its smallness
compared to the K\bar{K} one is not related to the OZI rule.


title:
Emittance fluctuation of mesoscopic conductors in the presence of
  disorders

abstract:
  We report the investigation of the dynamic conductance fluctuation of
disordered mesoscopic conductors including 1D, 2D and quantum dot systems. Our
numerical results show that in the quasi-ballistic regime the average emittance
is negative indicating the expected inductive-like behavior. However, in the
diffusive and localized regime, the average emittance is still negative. This
disagrees qualitatively with the result obtained from the random matrix theory.
Our analysis suggests that this counter-intuitive result is due to the
appearance of non-diffusive elements in the system, the necklace states (or the
precursor of necklace states in the diffusive regime) whose existence has been
confirmed experimentally in an optical system.


title:
Ultimate-state scaling in a shell model for homogeneous turbulent
  convection

abstract:
  An interesting question in turbulent convection is how the heat transport
depends on the strength of thermal forcing in the limit of very large thermal
forcing. Kraichnan predicted [Phys. Fluids {\bf 5}, 1374 (1962)] that the heat
transport measured by the Nusselt number (Nu) would depend on the strength of
thermal forcing measured by the Rayleigh number (Ra) as Nu $\sim$ Ra$^{1/2}$
with possible logarithmic corrections at very high Ra. This scaling behavior is
taken as a signature of the so-called ultimate state of turbulent convection.
The ultimate state was interpreted in the Grossmann-Lohse (GL) theory [J. Fluid
Mech. {\bf 407}, 27 (2000)] as a bulk-dominated state in which both the kinetic
and thermal dissipation are dominated by contributions from the bulk of the
flow with the boundary layers either broken down or playing no role in the heat
transport. In this paper, we study the dependence of Nu and the Reynolds number
(Re) measuring the root-mean-squared velocity fluctuations on Ra and the
Prandtl number (Pr) using a shell model for homogeneous turbulent convection
where buoyancy is acting directly on most of the scales. We find that Nu$\sim$
Ra$^{1/2}$Pr$^{1/2}$ and Re$\sim$ Ra$^{1/2}$Pr$^{-1/2}$, which resemble the
ultimate-state scaling behavior for fluids with moderate Pr, but the presence
of a drag acting on the large scales is crucial in giving rise to such scaling.
This suggests that if buoyancy acts on most of the scales in the bulk of
turbulent convection at very high Ra, then the ultimate state cannot be a
bulk-dominated state.


title: Dimensions of Biquadratic Spline Spaces over T-meshes

abstract:
  This paper discusses the dimensions of the spline spaces over T-meshes with
lower degree. Two new concepts are proposed: extension of T-meshes and spline
spaces with homogeneous boundary conditions. In the dimension analysis, the key
strategy is linear space embedding with the operator of mixed partial
derivative. The dimension of the original space equals the difference between
the dimension of the image space and the rank of the constraints which ensuring
any element in the image space has a preimage in the original space. Then the
dimension formula and basis function construction of bilinear spline spaces of
smoothness order zero over T-meshes are discussed in detail, and a dimension
lower bound of biquadratic spline spaces over general T-meshes is provided.
Furthermore, using level structure of hierarchical T-meshes, a dimension
formula of biquadratic spline space over hierarchical T-meshes are proved. A
topological explantation of the dimension formula is shown as well.


title: Refined similarity hypotheses in shell models of turbulence

abstract:
  A major challenge in turbulence research is to understand from first
principles the origin of anomalous scaling of the velocity fluctuations in
high-Reynolds-number turbulent flows. One important idea was proposed by
Kolmogorov [J. Fluid Mech. {\bf 13}, 82 (1962)], which attributes the anomaly
to the variations of the locally averaged energy dissipation rate. Kraichnan
later pointed out [J. Fluid Mech. {\bf 62}, 305 (1973)] that the locally
averaged energy dissipation rate is not an inertial-range quantity and a proper
inertial-range quantity would be the local energy transfer rate. As a result,
Kraichnan's idea attributes the anomaly to the variations of the local energy
transfer rate. These ideas, generally known as refined similarity hypotheses,
can also be extended to study the anomalous scaling of fluctuations of an
active scalar, like the temperature in turbulent convection. In this paper, we
examine the validity of these refined similarity hypotheses and their
extensions to an active scalar in shell models of turbulence. We find that
Kraichnan's refined similarity hypothesis and its extension are valid.


title: Short proofs of strong normalization

abstract:
  This paper presents simple, syntactic strong normalization proofs for the
simply-typed lambda-calculus and the polymorphic lambda-calculus (system F)
with the full set of logical connectives, and all the permutative reductions.
The normalization proofs use translations of terms and types to systems, for
which strong normalization property is known.


title: Intermittency and rough-pipe turbulence

abstract:
  Recently, by analyzing the measurement data of Nikuradze, it has been
proposed (N. Goldenfeld, Phys. Rev. Lett. {\bf{96}}, 044503, 2006) that the
friction factor, $f$, of rough pipe flow obeys a scaling law in the turbulent
regime. Here, we provide a phenomenological scaling argument to explain this
law and demonstrate how intermittency modifies the scaling form, thereby
relating $f$ to the intermittency exponent, $\eta$. By statistically analyzing
the measurement data of $f$, we infer a satisfactory estimate for $\eta$
($\approx 0.02$), the inclusion of which is shown to improve the data-collapse
curve. This provides empirical evidence for intermittency other than the direct
measurement of velocity fluctuations.


title:
Ab initio approach of the hydrogen insertion effects on the magnetic
  properties of $ {\bf ScFe_2} $

abstract:
  The electronic and magnetic structures of $ {\rm ScFe_2} $ and of its
dihydride $ {\rm ScFe_2H_2} $ are self-consistently calculated within the
density functional theory (DFT) using the all electron augmented spherical wave
(ASW) method with the local spin density approximation (LSDA) for treating
effects of exchange and correlation. The results of the enhancement of the
magnetization upon hydrogen insertion are assessed within an analysis of the
chemical bonding properties from which we suggest that both hydrogen bond with
iron and cell expansion effects play a role in the change of the magnitude of
magnetization. In agreement with average experimental findings for both the
intermetallic system and its dihydride, the calculated Fermi contact terms
$H_{FC}$ of the $^{57}$Fe M\"ossbauer spectroscopy for hyperfine field, at the
two iron sites, exhibit an original inversion for the order of magnitudes upon
hydriding.


title:
Understanding the different scaling behavior in various shell models
  proposed for turbulent thermal convection

abstract:
  Different scaling behavior has been reported in various shell models proposed
for turbulent thermal convection. In this paper, we show that buoyancy is not
always relevant to the statistical properties of these shell models even though
there is an explicit coupling between velocity and temperature in the equations
of motion. When buoyancy is relevant (irrelevant) to the statistical
properties, the scaling behavior is Bolgiano-Obukhov (Kolmogorov) plus
intermittency corrections. We show that the intermittency corrections of
temperature could be solely attributed to fluctuations in the entropy transfer
rate when buoyancy is relevant but due to fluctuations in both energy and
entropy transfer rates when buoyancy is irrelevant. This difference can be used
as a criterion to distinguish whether temperature is behaving as an active or a
passive scalar.


title: Identifying the outflow driving sources in Orion-KL

abstract:
  The enigmatic outflows of the Orion-KL region have raised discussions about
their potential driving sources for several decades. Here, we present C18O(2-1)
observations combined from the Submillimeter Array and the IRAM30m telescope.
The molecular gas is associated on large scales with the famous
northwest-southeast high-velocity outflow whereas the high-velocity gas on
small spatial scales traces back to the recently identified submm source SMA1.
Therefore, we infer that SMA1 may host the driving source of this outflow.
Based on the previously published thermal and maser SiO data, source I is the
prime candidate to drive the northeast-southwest low-velocity outflow. The
source SMA1 is peculiar because it is only detected in several submm wavelength
bands but neither in the infrared nor cm regime. We discuss that it may be a
very young intermediate- to high-mass protostar. The estimated outflow masses
are high whereas the dynamical time-scale of the outflow is short of the order
10^3yrs.


title: Effective temperature for hopping transport in a Gaussian DOS

abstract:
  For hopping transport in disordered materials, the mobility of charge
carriers is strongly dependent on temperature and the electric field. Our
numerical study shows that both the energy distribution and the mobility of
charge carriers in systems with a Gaussian density of states, such as organic
disordered semiconductors, can be described by a single parameter - effective
temperature, dependent on the magnitude of the electric field. Furthermore,
this effective temperature does not depend on the concentration of charge
carriers, while the mobility does depend on the charge carrier concentration.
The concept of the effective temperature is shown to be valid for systems with
and without space-energy correlations in the distribution of localized states.


title:
Phase space quantization and Loop Quantum Cosmology: A Wigner function
  for the Bohr-compactified real line

abstract:
  We give a definition for the Wigner function for quantum mechanics on the
Bohr compactification of the real line and prove a number of simple
consequences of this definition. We then discuss how this formalism can be
applied to loop quantum cosmology. As an example, we use the Wigner function to
give a new quantization of an important building block of the Hamiltonian
constraint.


title: A supercurrent switch in graphene $\pi$-junctions

abstract:
  We study the supercurrent in a superconductor/ferromagnet/superconductor
graphene junction. In contrast to its metallic counterpart, the oscillating
critical current in our setup decays only weakly upon increasing exchange field
and junction width. We find an unusually large residual value of the
supercurrent at the oscillatory cusps due to a strong deviation from a
sinusoidal current-phase relationship. Our findings suggest a very efficient
device for dissipationless supercurrent switching.


title: On the Numerical Evaluation of Fredholm Determinants

abstract:
  Some significant quantities in mathematics and physics are most naturally
expressed as the Fredholm determinant of an integral operator, most notably
many of the distribution functions in random matrix theory. Though their
numerical values are of interest, there is no systematic numerical treatment of
Fredholm determinants to be found in the literature. Instead, the few numerical
evaluations that are available rely on eigenfunction expansions of the
operator, if expressible in terms of special functions, or on alternative,
numerically more straightforwardly accessible analytic expressions, e.g., in
terms of Painleve transcendents, that have masterfully been derived in some
cases. In this paper we close the gap in the literature by studying projection
methods and, above all, a simple, easily implementable, general method for the
numerical evaluation of Fredholm determinants that is derived from the
classical Nystrom method for the solution of Fredholm equations of the second
kind. Using Gauss-Legendre or Clenshaw-Curtis as the underlying quadrature
rule, we prove that the approximation error essentially behaves like the
quadrature error for the sections of the kernel. In particular, we get
exponential convergence for analytic kernels, which are typical in random
matrix theory. The application of the method to the distribution functions of
the Gaussian unitary ensemble (GUE), in the bulk and the edge scaling limit, is
discussed in detail. After extending the method to systems of integral
operators, we evaluate the two-point correlation functions of the more recently
studied Airy and Airy1 processes for the first time.


title:
Galaxy Distribution as a Probe of the Ringlike Dark Matter Structure in
  the Galaxy Cluster Cl0024+17

abstract:
  In a galaxy cluster, galaxies are mostly collisionless particles in recent
epoches. They resemble collisionless cold dark matter particles in some way.
Therefore, the spatial distributions of dark matter and cluster galaxies might
be expected to possess similar features in the gravitational potential of a
cluster. Here we use the galaxy distribution in cluster Cl0024+17 to probe for
the ringlike dark matter structure recently discovered by means of strong and
weak lensing observations. The galaxies are taken from the catalog of Czoske et
al., which contains 650 objects with measured redshifts, of which ~300 galaxies
have redshifts in the range 0.37<z<0.41 (and are therefore probable cluster
members). We find that, at about the 3-sigma level, the ringlike structure seen
in the dark matter measurement is not observed in the projected two-dimensional
galaxy distribution.


title: On the solubility of Nd3+ in Y3Al5O12

abstract:
  Neodymium doped yttrium aluminum garnet powders (Nd:YAG or
(Y{1-x}Nd{x})3Al5O12, x=0.15, 0.25, or 0.30, respectively) were prepared by a
sol-gel technique. By DTA measurements up to 2000 deg C eutectic and liquidus
temperatures could be determined. Exothermal peaks in the second and subsequent
DTA heating runs indicate that the crystallized DTA samples are not in
equilibrium. The section Y3Al5O12-Nd3Al5O12 of the concentration triangle
Al2O3-Nd2O3-Y2O3 is proposed on the basis of thermodynamic calculations that
allows to explain the experimental results by the balance of metastable phase
states in the previously crystallized DTA samples.


title:
The Interplay of Landau Level Broadening and Temperature on
  Two-Dimensional Electron Systems

abstract:
  This work investigates the influence of low temperature and broadened Landau
levels on the thermodynamic properties of two-dimensional electron systems. The
interplay between these two physical parameters on the magnetic field
dependence of the chemical potential, the specific heat and the magnetization
is calculated. In the absence of a complete theory that explains the Landau
level broadening, experimental and theoretical studies in literature perform
different model calculations of this parameter. Here it is presented that
different broadening parameters of Gaussian-shaped Landau levels cause width
variations in their contributions to interlevel and intralevel excitations.
Below a characteristic temperature, the interlevel excitations become
negligible. Likewise, at this temperature range, the effect of the Landau level
broadening vanishes.


title:
Microlocal smoothing effect for the Schr\"odinger evolution equation in
  a Gevrey class

abstract:
  We discuss the microlocal Gevrey smoothing effect for the Schr\"odinger
equation with variable coefficients via the propagation property of the wave
front set of homogenous type. We apply the microlocal exponential estimates in
a Gevrey case to prove our result.


title:
Role of Frustration and Dimensionality in the Hubbard Model on the
  Stacked Square Lattice: Variational Cluster Approach

abstract:
  Using variational cluster approach, we study influence of frustration and
dimensionality on magnetic properties in the ground state of Hubbard model on a
stacked square lattice in the large $U$ region (U/t=10), by changing the
next-nearest-neighbor hopping, $t^{\prime}$, and the interlayer hopping,
$t_{\perp}$. For small $t_{\perp}<t^{\ast}_{\perp}$ with
$t^{\ast}_{\perp}/t{\approx}0.44$, antiferromagnetic long-range order appears
at small $t^{\prime}<t^{\prime}_{c_{1}}$, and collinear magnetic long-range
order at large $t^{\prime}>t^{\prime}_{c_{2}}$. They are separated by a
paramagnetic Mott insulating state which appears in the parameter region
$t^{\prime}_{c_{1}}<t^{\prime}<t^{\prime}_{c_{2}}$. For large
$t_{\perp}>t^{\ast}_{\perp}$, the paramagnetic Mott insulating state disappears
and a direct transition between antiferromagnetic state and collinear magnetic
state occurs at $t^{\prime}=t^{\prime}_{c_{3}}$. We also find that the
transition from the antiferromagnetic state to the paramagnetic Mott insulating
state is of the second-order and that from the collinear magnetic state to the
paramagnetic Mott insulating or the antiferromagnetic state is of the
first-order.


title:
Simulations of light scalar mesons on the lattice and related
  difficulties

abstract:
  I review the lattice simulations of light scalar mesons with quark-antiquark
and tetraquark interpolating fields. Several difficulties which complicate the
extraction of scalar meson masses from the scalar correlators are pointed out.
One of the major difficulties is the presence of the two-pseudoscalar
scattering states, which often dominate the correlator at light quark masses.
In the simulations with unphysical approximations such scattering contributions
are even more disturbing since they are often large and sometimes negative.
Techniques which allow extraction of scalar meson masses in presence of
scattering states are listed. Preliminary results of various lattice
collaborations are presented.


title: Poisson processes for subsystems of finite type in symbolic dynamics

abstract:
  Let $\Delta\subsetneq\V$ be a proper subset of the vertices $\V$ of the
defining graph of an irreducible and aperiodic shift of finite type
$(\Sigma_{A}^{+},\S)$. Let $\Sigma_{\Delta}$ be the subshift of allowable paths
in the graph of $\Sigma_{A}^{+}$ which only passes through the vertices of
$\Delta$. For a random point $x$ chosen with respect to an equilibrium state
$\mu$ of a H\"older potential $\phi$ on $\Sigma_{A}^{+}$, let $\tau_{n}$ be the
point process defined as the sum of Dirac point masses at the times $k>0$,
suitably rescaled, for which the first $n$-symbols of $\S^k x$ belong to
$\Delta$. We prove that this point process converges in law to a marked Poisson
point process of constant parameter measure. The scale is related to the
pressure of the restriction of $\phi$ to $\Sigma_{\Delta}$ and the parameters
of the limit law are explicitly computed.


title:
On the asymptotic measure of periodic subsystems of finite type in
  symbolic dynamics

abstract:
  Let $\Delta\subsetneq\V$ be a proper subset of the vertices $\V$ of the
defining graph of an aperiodic shift of finite type $(\Sigma_{A}^{+},\S)$. Let
$\Delta_{n}$ be the union of cylinders in $\Sigma_{A}^{+}$ corresponding to the
points $x$ for which the first $n$-symbols of $x$ belong to $\Delta$ and let
$\mu$ be an equilibrium state of a H\"older potential $\phi$ on
$\Sigma_{A}^{+}$. We know that $\mu(\Delta_{n})$ converges to zero as $n$
diverges. We study the asymptotic behaviour of $\mu(\Delta_{n})$ and compare it
with the pressure of the restriction of $\phi$ to $\Sigma_{\Delta}$. The
present paper extends some results in \cite{CCC} to the case when
$\Sigma_{\Delta}$ is irreducible and periodic. We show an explicit example
where the asymptotic behaviour differs from the aperiodic case.


title: Infinitesimal Derived Torelli Theorem for K3 surfaces

abstract:
  We prove that the first order deformations of two smooth projective K3
surfaces are derived equivalent under a Fourier--Mukai transform if and only if
there exists a special isometry of the total cohomology groups of the surfaces
which preserves the Mukai pairing, an infinitesimal weight-2 decomposition and
the orientation of a positive 4-dimensional space. This generalizes the derived
version of the Torelli Theorem. Along the way we show the compatibility of the
actions on Hochschild homology and singular cohomology of any Fourier--Mukai
functor.


title:
Accurate distances to nearby massive stars with the new reduction of the
  Hipparcos raw data

abstract:
  We use the new reduction of the Hipparcos data (van Leeuwen 2007) and a
self-consistent distance determination technique for Lutz-Kelker limited
samples to obtain distances to the massive stars in the solar vicinity. The
distance uncertainties for the nearest massive stars have been substantially
reduced with respect to those derived from the old Hipparcos reduction. In two
cases (gamma2 Vel and theta2 Ori A) we have been able to verify that the new
values are in good agreement with recent determinations with alternative
methods. We also derive new values for the vertical displacement of the Sun
with respect to the Galactic Plane and for the scale height of the thin disk
from the spatial distribution of massive stars around us.


title: Frequency spectrum of the Casimir force: interpretation and a paradox

abstract:
  The frequency spectrum of the Casimir force between two plates separated by
vacuum as it appears in the Lifshitz formalism is reexamined and generalised as
compared to previous works to allow for imperfectly reflecting plates. As
previously reported by Ford [Phys. Rev. A \textbf{48} (1993) 2962], the highly
oscillatory nature of the frequency dependence of the Casimir force points to
possibilities for very large and indeed negative Casimir forces if the
frequency-dependent dielectric response, $\epsilon(\omega)$, of the materials
could be tuned. A paradox occurs, however, because an alternative calculation
of the effect of a perturbation of $\epsilon(\omega)$ involving a Wick rotation
to imaginary frequencies indicate only very modest effects. A recent experiment
appears to convincingly rule out the reality of Ford's optimistic predictions,
although given the enormous technological promise of such frequency effects,
further theoretical and experimental study is called for.


title:
Modeling the interstellar aromatic infrared bands with co-added spectra
  of PAHs

abstract:
  The observed variations in profiles of the interstellar aromatic infrared
bands correlate with the object type and are indicative of PAH populations
existing i n different sources. Spectroscopic studies on PAHs can provide tools
for the int erpretation of variations accompanying the AIBs. As the observed
spectra results from a mix of possible species in the region attempt is made to
model this comp osite spectra by co-adding emissions from PAHs in different
size groups. Theoretical IR data of PAHs having 10 to 96 carbon atoms is used
to obtain emis sion spectra. The models are taken in size groups making up of
small, medium and large PAHs. The models show good profile match with
observations for the 7.7 $\mu m$ complex having sub-features at 7.6 and 7.8
$\mu m$. The 7.6 $\mu m$ sub-feature dominates in the spectra of medium sized
PAH cations matching observations from UV rich interstellar environments. The
7.8 $\mu m$ component is more intense in the spectra of large PAH cations
(model III) correlating with observations from benign astrophysical regions. A
possible interpretation for the observations of $C-H$ out-of-plane bend modes
and the weak outliers on the blue side of the intense 11.2 $\mu m$ band is
proposed. The models provide pointers to possible PAH populations in different
regions.


title: Multi-dimensional numerical simulations of type Ia supernova explosions

abstract:
  The major role type Ia supernovae play in many fields of astrophysics and in
particular in cosmological distance determinations calls for self-consistent
models of these events. Since their mechanism is believed to crucially depend
on phenomena that are inherently three-dimensional, self-consistent numerical
models of type Ia supernovae must be multi-dimensional. This field has recently
seen a rapid development, which is reviewed in this article. The different
modeling approaches are discussed and as an illustration a particular explosion
model -- the deflagration model -- in a specific numerical implementation is
presented in greater detail. On this exemplary case, the procedure of
validating the model on the basis of comparison with observations is discussed
as well as its application to study questions arising from type Ia supernova
cosmology.


title:
Single-band tight-binding parameters for Fe-MgO-Fe magnetic
  heterostructures

abstract:
  We present a computationally efficient transferable single-band tight-binding
model (SBTB) for spin polarized transport in heterostructures with an effort to
capture the band structure effects. As an example, we apply it to study
transport through Fe-MgO-Fe(100) magnetic tunnel junction devices. We propose a
novel approach to extract suitable tight-binding parameters for a material by
using the energy resolved transmission as the benchmark, which inherently has
the bandstructure effects over the two dimensional transverse Brillouin zone.
The SBTB parameters for each of the four symmetry bands for bcc Fe(100) are
first proposed which are complemented with the transferable tight-binding
parameters for the MgO tunnel barrier for the Delta_1 and Delta_5 bands. The
non-equilibrium Green's function formalism is then used to calculate the
transport. Features like I-V characteristics, voltage dependence and the
barrier width dependence of the tunnel magnetoresistance ratio are captured
quantitatively and the trends match well with the ones observed by ab initio
methods.


title: On cohomologically complete intersections

abstract:
  An ideal $I$ of a local Gorenstein ring $(R, \mathfrak m)$ is called
cohomologically complete intersection whenever $H^i_I(R) = 0$ for all $i \not=
\height I.$ Here $H^i_I(R), i \in \mathbb Z,$ denotes the local cohomology of
$R$ with respect to $I.$ For instance, a set-theoretic complete intersection is
a cohomologically complete intersection. Here we study cohomologically complete
intersections from various homological points of view, in particular in terms
of their Bass numbers of $H^c_I(R), c = \height I.$ As a main result it is
shown that the vanishing $H^i_I(R) = 0$ for all $i \not= c$ is completely
encoded in homological properties of $H^c_I(R),$ in particular in its Bass
numbers.


title: Spin degrees and Polarization Observables in Electromagnetic Reactions

abstract:
  After a brief introduction into the general importance of polarization
observables for the analysis of a reaction, the basic density matrix formalism
for the description of polarization phenomena is outlined and illustrated by
explicit examples for spin one-half and one. Then various electromagnetic
processes like photoreactions and electron scattering are discussed in some
detail. Finally, the question of how to determine a complete set of
polarization observables providing the maximum information on a reaction is
considered.


title:
Injection of Oort Cloud Comets: The Fundamental Role of Stellar
  Perturbations

abstract:
  We present Monte Carlo simulations of the dynamical evolution of the Oort
cloud over the age of the Solar System, using an initial sample of one million
test comets without any cloning. Our model includes perturbations due to the
Galactic tide (radial and vertical) and passing stars. We present the first
detailed analysis of the injection mechanism into observable orbits by
comparing the complete model with separate models for tidal and stellar
perturbations alone. We find that a fundamental role for injecting comets from
the region outside the loss cone (perihelion distance q > 15 AU) into
observable orbits (q < 5 AU) is played by stellar perturbations. These act in
synergy with the tide such that the total injection rate is significantly
larger than the sum of the two separate rates. This synergy is as important
during comet showers as during quiescent periods and concerns comets with both
small and large semi-major axes. We propose different dynamical mechanisms to
explain the synergies in the inner and outer parts of the Oort Cloud. We find
that the filling of the observable part of the loss cone under normal
conditions in the present-day Solar System rises from <1 % for a < 20 000 AU to
about 100 % for a >= 100 000 AU.


title:
Max-Plus decomposition of supermartingales and convex order. Application
  to American options and portfolio insurance

abstract:
  We are concerned with a new type of supermartingale decomposition in the
Max-Plus algebra, which essentially consists in expressing any supermartingale
of class $(\mathcal{D})$ as a conditional expectation of some running supremum
process. As an application, we show how the Max-Plus supermartingale
decomposition allows, in particular, to solve the American optimal stopping
problem without having to compute the option price. Some illustrative examples
based on one-dimensional diffusion processes are then provided. Another
interesting application concerns the portfolio insurance. Hence, based on the
``Max-Plus martingale,'' we solve in the paper an optimization problem whose
aim is to find the best martingale dominating a given floor process (on every
intermediate date), w.r.t. the convex order on terminal values.


title: Pressure and Equilibrium States in Ergodic Theory

abstract:
  Our goal is to present the basic results on one-dimensional Gibbs and
equilibrium states viewed as special invariant measures on symbolic dynamical
systems, and then to describe without technicalities a sample of results they
allowed to obtain for certain differentiable dynamical systems. We hope that
this contribution will illustrate the symbiotic relationship between ergodic
theory and statistical mechanics, and also information theory.


title: Does the Chapman-Enskog expansion for viscous granular flows converge?

abstract:
  This paper deals with the convergence/divergence issue of the Chapman-Enskog
series expansion of the shear and normal stresses for a granular gas of
inelastic hard spheres. From the exact solution of a simple kinetic model in
the uniform shear and longitudinal flows, it is shown that (except in the
elastic limit) both series converge and their respective radii of convergence
increase with inelasticity. This paradoxical result can be understood in terms
of the time evolution of the Knudsen number and the existence of a
nonequilibrium steady state.


title:
Painleve IV asymptotics for orthogonal polynomials with respect to a
  modified Laguerre weight

abstract:
  We study polynomials that are orthogonal with respect to the modified
Laguerre weight $z^{-n + \nu} e^{-Nz} (z-1)^{2b}$ in the limit where $n, N \to
\infty$ with $N/n \to 1$ and $\nu$ is a fixed number in $\mathbb{R} \setminus
\mathbb{N}_0$. With the effect of the factor $(z-1)^{2b}$, the local parametrix
near the critical point $z =1$ can be constructed in terms of $\Psi$-functions
associated with the Painleve IV equation. We show that the asymptotics of the
recurrence coefficients of orthogonal polynomials can be described in terms of
specified solution of the Painleve IV equation in the double scaling limit. Our
method is based on the Deift/Zhou steepest decent analysis of the
Riemann-Hilbert problem associated with orthogonal polynomials.


title: Newns-Anderson model of chemicurrents in H/Cu and H/Ag

abstract:
  The excitation of the electronic system induced by the adsorption of a
hydrogen atom on the (111) surfaces of copper and silver is investigated using
the time-dependent, mean-field Newns-Anderson model. Parameters for the model
are obtained by fitting to density functional theory calculations, allowing the
charge and energy transfer between adsorbate and surface to be calculated,
together with the spectrum of electronic excitations. These results are used to
make direct comparisons with experimental measurements of chemicurrents,
yielding good agreement for both the magnitude of the current and the ratio of
the currents for H and D adsorption.


title: Rheological properties of a granular impurity in the Couette flow

abstract:
  We discuss in this work the validity of the theoretical solution of the
nonlinear Couette flow for a granular impurity obtained in a recent work
[preprint arXiv:0802.0526], in the range of large inelasticity and shear rate.
We show there is a good agreement between the theoretical solution and Monte
Carlo simulation data, even under these extreme conditions. We also discuss an
extended theoretical solution that would work for large inelasticities in
ranges of shear rate $a$ not covered by our previous work (i.e., below the
threshold value $a_{th}$ for which uniform shear flow may be obtained) and
compare also with simulation data. Preliminary results in the simulations give
useful insight in order to obtain an exact and general solution of the
nonlinear Couette flow (both for $a\ge a_{th}$ and $a<a_{th}$).


title: An Investigation of 11 previously unstudied open star clusters

abstract:
  The main astrophysical properties of 11 previously unstudied open star
clusters are probed with JHK Near-IR (2MASS) photometry of Cutri et al. [Cutri,
R., et al., 2003. The IRSA 2MASS All-sky Point Source Catalog, NASA/IPAC
Infrared Science Archive] and proper motions (NOMAD) astrometry of Zacharias et
al. [Zacharias, N., Monet, D., Levine, S., Urban, S., Gaume, R., Wycoff, G.,
2004. American Astro. Soc. Meeting 36, 1418]. The fundamental parameters have
been derived for IC (1434, 2156); King (17, 18, 20, 23, 26)}; and Dias (2, 3,
4, 7, 8)}, for which no prior parameters are available in the literature. The
clusters' centers coordinates and angular diameters are re-determined, while
ages, distances, and color excesses for these clusters are estimated here for
the first time.


title:
Secretly Broadcasting Five Qubit Entangled state among three parties
  from W- type states

abstract:
  In this work we investigate the problem of secretly broadcasting five qubit
entangled state between three different partners We implement the protocol
described in ref [16] on three particle W-state shared by three distant
partners Alice,Bob and Charlie. The problem is interesting in the sense it is
the first attempt to broadcast five qubit entangled state between three
parties.


title: Unconditional jetting

abstract:
  Capillary jetting of a fluid dispersed into another immiscible phase is
usually limited by a critical Capillary number, a function of the Reynolds
number and the fluid properties ratios. Critical conditions are set when the
minimum spreading velocity of small perturbations $v^*_-$ along the jet
(marginal stability velocity) is zero. Here we identify and describe
parametrical regions of high technological relevance, where $v^*_- > 0$ and the
jet flow is always supercritical independently of the dispersed liquid flow
rate: within these relatively broad regions, the jet does not undergo the usual
dripping-jetting transition, so that either the jet can be made arbitrarily
thin (yielding droplets of any imaginably small size), or the issued flow rate
can be made arbitrarily small. In this work, we provide illustrative analytical
studies of asymptotic cases for both negligible and dominant inertia forces. In
this latter case, requiring a non-zero jet surface velocity, axisymmetric
perturbation waves ``surf'' downstream for all given wave numbers while the
liquid bulk can remain static. In the former case (implying small Reynolds
flow) we found that the jet profile small slope is limited by a critical value;
different published experiments support our predictions.


title:
Particle linear theory on a self-gravitating perturbed cubic Bravais
  lattice

abstract:
  Discreteness effects are a source of uncontrolled systematic errors of N-body
simulations, which are used to compute the evolution of a self-gravitating
fluid. We have already developed the so-called "Particle Linear Theory" (PLT),
which describes the evolution of the position of self-gravitating particles
located on a perturbed simple cubic lattice. It is the discrete analogue of the
well-known (Lagrangian) linear theory of a self-gravitating fluid. Comparing
both theories permits to quantify precisely discreteness effects in the linear
regime. It is useful to develop the PLT also for other perturbed lattices
because they represent different discretizations of the same continuous system.
In this paper we detail how to implement the PLT for perturbed cubic Bravais
lattices (simple, body and face-centered) in a cubic simulation box. As an
application, we will study the discreteness effects -- in the linear regime --
of N-body simulations for which initial conditions have been set-up using these
different lattices.


title: Optical properties of nanostructured GaSb

abstract:
  Optical measurements of nanostructured GaSb prepared by sputtering is
presented. The optical response is studied by Mueller Matrix Ellipsometry (MME)
in the visible range (430--850nm), and by spectroscopic ellipsometry in the
range 0.6--6.5eV. The nano-structured surfaces reported in this work, consist
of densely packed GaSb cones approximately 50nm high, on bulk GaSb. The
nanostructured surfaces are here shown to considerably modify the optical
response of the surface, hence giving a strong sensitivity to the far field
spectroscopic (Mueller matrix) ellipsometric measurements. The off-specular
scattering and the depolarization is found to be low. The anisotropic response
is particularly emphasized by studying nano-structured GaSb cones approximately
45 degrees tilted with respect to the surface normal. In the latter case, one
observes upon rotating the sample around the surface normal, that the Mueller
matrix elements $m_{13}$ and $m_{14}$ oscillate as a function of the rotation
angle. Finally, Mueller matrix techniques have been applied to the measured
data, in order to analyze the acquired Mueller matrix in terms of physical
realizability and noise.


title: The allelic partition for coalescent point processes

abstract:
  Assume that individuals alive at time $t$ in some population can be ranked in
such a way that the coalescence times between consecutive individuals are
i.i.d. The ranked sequence of these branches is called a coalescent point
process. We have shown in a previous work that splitting trees are important
instances of such populations. Here, individuals are given DNA sequences, and
for a sample of $n$ DNA sequences belonging to distinct individuals, we
consider the number $S_n$ of polymorphic sites (sites at which at least two
sequences differ), and the number $A_n$ of distinct haplotypes (sequences
differing at one site at least). It is standard to assume that mutations arrive
at constant rate (on germ lines), and never hit the same site on the DNA
sequence. We study the mutation pattern associated to coalescent point
processes under this assumption. Here, $S_n$ and $A_n$ grow linearly as $n$
grows, with explicit rate. However, when the branch lengths have infinite
expectation, $S_n$ grows more rapidly, e.g. as $n \ln(n)$ for critical
birth--death processes. Then, we study the frequency spectrum of the sample,
that is, the numbers of polymorphic sites/haplotypes carried by $k$ individuals
in the sample. These numbers are shown to grow also linearly with sample size,
and we provide simple explicit formulae for mutation frequencies and haplotype
frequencies. For critical birth--death processes, mutation frequencies are
given by the harmonic series and haplotype frequencies by Fisher logarithmic
series.


title: The spectrum of scalar-meson nonets in the Resonance-Spectrum Expansion

abstract:
  We argue that the low-lying scalar-meson nonet makes part of a subset of a
family of infinitely many scalar-meson nonets, which in turn makes part of a
family of infinitely many quark-antiquark bound states and resonances. We
outline the properties of this subset.


title:
The standard "static" spherically symmetric ansatz with perfect fluid
  source revisited

abstract:
  Considering the standard "static" spherically symmetric ansatz ds2 = -B(r)
dt2 + A(r) dr2 + r2 dOmega2 for Einstein's Equations with perfect fluid source,
we ask how we can interpret solutions where A(r) and B(r) are not positive, as
they must be for the static matter source interpretation to be valid.
  Noting that the requirement of Lorentzian signature implies A(r) B(r) >0, we
find two possible interpretations:
  (i) The nonzero component of the source four-velocity does not have to be u0.
This provides a connection from the above ansatz to the Kantowski-Sachs (KS)
spacetimes.
  (ii) Regions with negative A(r) and B(r) of "static" solutions in the
literature must be interpreted as corresponding to tachyonic source.
  The combinations of source type and four-velocity direction result in four
possible cases. One is the standard case, one is identical to the KS case, and
two are tachyonic. The dynamic tachyonic case was anticipated in the
literature, but the static tachyonic case seems to be new. We derive
Oppenheimer-Volkoff-like equations for each case, and find some simple
solutions. We conclude that new "simple" black hole solutions of the above
form, supported by a perfect fluid, do not exist.


title: Structural properties of spatially embedded networks

abstract:
  We study the effects of spatial constraints on the structural properties of
networks embedded in one or two dimensional space. When nodes are embedded in
space, they have a well defined Euclidean distance $r$ between any pair. We
assume that nodes at distance $r$ have a link with probability $p(r) \sim r^{-
\delta}$. We study the mean topological distance $l$ and the clustering
coefficient $C$ of these networks and find that they both exhibit phase
transitions for some critical value of the control parameter $\delta$ depending
on the dimensionality $d$ of the embedding space. We have identified three
regimes. When $\delta <d$, the networks are not affected at all by the spatial
constraints. They are ``small-worlds'' $l\sim \log N$ with zero clustering at
the thermodynamic limit. In the intermediate regime $d<\delta<2d$, the networks
are affected by the space and the distance increases and becomes a power of
$\log N$, and have non-zero clustering. When $\delta>2d$ the networks are
``large'' worlds $l \sim N^{1/d}$ with high clustering. Our results indicate
that spatial constrains have a significant impact on the network properties, a
fact that should be taken into account when modeling complex networks.


title:
Interlace Polynomials: Enumeration, Unimodality, and Connections to
  Codes

abstract:
  The interlace polynomial q was introduced by Arratia, Bollobas, and Sorkin.
It encodes many properties of the orbit of a graph under edge local
complementation (ELC). The interlace polynomial Q, introduced by Aigner and van
der Holst, similarly contains information about the orbit of a graph under
local complementation (LC). We have previously classified LC and ELC orbits,
and now give an enumeration of the corresponding interlace polynomials of all
graphs of order up to 12. An enumeration of all circle graphs of order up to 12
is also given. We show that there exist graphs of all orders greater than 9
with interlace polynomials q whose coefficient sequences are non-unimodal,
thereby disproving a conjecture by Arratia et al. We have verified that for
graphs of order up to 12, all polynomials Q have unimodal coefficients. It has
been shown that LC and ELC orbits of graphs correspond to equivalence classes
of certain error-correcting codes and quantum states. We show that the
properties of these codes and quantum states are related to properties of the
associated interlace polynomials.


title: Cold Fermi atomic gases in a pumped optical resonator

abstract:
  We study systems of fully polarized ultracold atomic gases obeying Fermi
statistics. The atomic transition interacts dispersively with a mode of a
standing-wave cavity, which is coherently pumped by a laser. In this setup, the
intensity of the intracavity field is determined by the refractive index of the
atomic medium, and thus by the atomic density distribution. Vice versa, the
density distribution of the atom is determined by the cavity field potential,
whose depth is proportional to the intracavity field amplitude. In this work we
show that this nonlinearity leads to an instability in the intracavity
intensity that differs substantially from dispersive optical bistability, as
this effect is already present in the regime, where the atomic dipole is
proportional to the cavity field. Such instability is driven by the matter
waves fluctuations and exhibits a peculiar dependence on the fluctuations in
the atomic density distribution.


title: On the Index of Congruence Subgroups of Aut(F_n)

abstract:
  For an epimorphism pi of the free group F_n onto a finite group G write
Gamma(G,pi) for the group of all automorphisms f of F_n for which pi*f = pi.
This is called the standard congruence subgroup of Aut(F_n) associated to G and
pi. In the case n = 2 we present formulas for the index of Gamma(G,pi) where G
is abelian or dihedral. Moreover, we show that congruence subgroups associated
to dihedral groups provide a family of subgroups of arbitrary large index in
Aut(F_2) generated by a fixed number of elements. This implies that finite
index subgroups of Aut(F_2) cannot be written as free products.


title: Cosmological Imprint of the Second Law of Thermodynamics

abstract:
  We study the evolution of the universe in the presence of inflaton, matter,
radiation, and holographic dark energy. The time evolution of the scale factor
is obtained by solving the Friedmann equation of the universe with a good
approximation. We present two independent ways which determine the value of the
dark energy constant $d\sim 1$ from the observational data. The two ways are
measuring the deceleration parameter and measuring a universal constant
depending only on $d$. The universal constant is given by a dimensionless
combination of three scale factors at the equipartition times of
radiation-matter, radiation-dark energy, and matter-dark energy. We also
discuss that the second law of thermodynamics determines the point of time when
the dark energy dominated era begins in the universe.


title:
Free expansion of a Lieb-Liniger gas: Asymptotic form of the wave
  functions

abstract:
  The asymptotic form of the wave functions describing a freely expanding
Lieb-Liniger gas is derived by using a Fermi-Bose transformation for
time-dependent states, and the stationary phase approximation. We find that
asymptotically the wave functions approach the Tonks-Girardeau (TG) structure
as they vanish when any two of the particle coordinates coincide. We point out
that the properties of these asymptotic states can significantly differ from
the properties of a TG gas in a ground state of an external potential. The
dependence of the asymptotic wave function on the initial state is discussed.
The analysis encompasses a large class of initial conditions, including the
ground states of a Lieb-Liniger gas in physically realistic external
potentials. It is also demonstrated that the interaction energy asymptotically
decays as a universal power law with time, $E_\mathrm{int}\propto t^{-3}$.


title:
Enhancement of optical switching parameter and third-order optical
  nonlinearities in embedded Si nanocrystals: a theoretical assessment

abstract:
  Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs)
embedded in a wide band-gap matrix representing silica are theoretically
studied using an atomistic pseudopotential approach. Nonlinear refractive
index, two-photon absorption and optical switching parameter are examined from
small clusters to NCs up to a size of 3 nm. Compared to bulk values, Si NCs
show higher third-order optical nonlinearities and much wider two-photon
absorption threshold which gives rise to enhancement in the optical switching
parameter.


title:
Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides
  ReFeAsO1-delta (Re = rare earth metal) without F-Doping

abstract:
  Here we report a new class of superconductors prepared by high pressure
synthesis in the quaternary family ReFeAsO1-delta (Re = Sm, Nd, Pr, Ce, La)
without fluorine doping. The onset superconducting critical temperature (Tc) in
these compounds increases with the reduction of Re atom size, and the highest
Tc obtained so far is 55 K in SmFeAsO1-delta. For the NdFeAsO1-delta system
with different oxygen concentration a dome-shaped phase diagram was found.


title:
Daubechies wavelets as a basis set for density functional
  pseudopotential calculations

abstract:
  Daubechies wavelets are a powerful systematic basis set for electronic
structure calculations because they are orthogonal and localized both in real
and Fourier space. We describe in detail how this basis set can be used to
obtain a highly efficient and accurate method for density functional electronic
structure calculations. An implementation of this method is available in the
ABINIT free software package. This code shows high systematic convergence
properties, very good performances and an excellent efficiency for parallel
calculations.


title: On Greedy Clique Decompositions and Set Representations of Graphs

abstract:
  In 1994 S. McGuinness showed that any greedy clique decompo- sition of an
n-vertex graph has at most $\lfloor n^2/4 \rfloor$ cliques (The greedy clique
decomposition of a graph, J. Graph Theory 18 (1994) 427-430), where a clique
decomposition means a clique partition of the edge set and a greedy clique
decomposition of a graph is obtained by removing maximal cliques from a graph
one by one until the graph is empty. This result solved a conjecture by P.
Winkler. A multifamily set rep- resentation of a simple graph G is a family of
sets, not necessarily distinct, each member of which represents a vertex in G,
and the in- tersection of two sets is non-empty if and only if two
corresponding vertices in G are adjacent. It is well known that for a graph G,
there is a one-to-one correspondence between multifamily set representations
and clique coverings of the edge set. Further for a graph one may have a
one-to-one correspondence between particular multifamily set rep- resentations
with intersection size at most one and clique partitions of the edge set. In
this paper, we study for an n-vertex graph the variant of the set
representations using a family of distinct sets, including the greedy way to
get the corresponding clique partition of the edge set of the graph. Similarly,
in this case, we obtain a result that any greedy clique decomposition of an
n-vertex graph has at most $\lfloor n^2/4 \rfloor$ cliques.


title: On the orthogonal polynomials associated with a L\'evy process

abstract:
  Let $X=\{X_t, t\ge0\}$ be a c\`{a}dl\`{a}g L\'{e}vy process, centered, with
moments of all orders. There are two families of orthogonal polynomials
associated with $X$. On one hand, the Kailath--Segall formula gives the
relationship between the iterated integrals and the variations of order $n$ of
$X$, and defines a family of polynomials $P_1(x_1), P_2(x_1,x_2),...$ that are
orthogonal with respect to the joint law of the variations of $X$. On the other
hand, we can construct a sequence of orthogonal polynomials $p^{\sigma}_n(x)$
with respect to the measure $\sigma^2\delta_0(dx)+x^2 \nu(dx)$, where
$\sigma^2$ is the variance of the Gaussian part of $X$ and $\nu$ its L\'{e}vy
measure. These polynomials are the building blocks of a kind of chaotic
representation of the square functionals of the L\'{e}vy process proved by
Nualart and Schoutens. The main objective of this work is to study the
probabilistic properties and the relationship of the two families of
polynomials. In particular, the L\'{e}vy processes such that the associated
polynomials $P_n(x_1,...,x_n)$ depend on a fixed number of variables are
characterized. Also, we give a sequence of L\'{e}vy processes that converge in
the Skorohod topology to $X$, such that all variations and iterated integrals
of the sequence converge to the variations and iterated integrals of $X$.


title: Spatiotemporal instability of a confined capillary jet

abstract:
  Recent experimental studies on the instability appearance of capillary jets
have revealed the capabilities of linear spatiotemporal instability analysis to
predict the parametrical map where steady jetting or dripping takes place. In
this work, we present an extensive analytical, numerical and experimental
analysis of confined capillary jets extending previous studies. We propose an
extended, accurate analytic model in the limit of low Reynolds flows, and
introduce a numerical scheme to predict the system response when the liquid
inertia is not negligible. Theoretical predictions show a remarkable accuracy
with results from the extensive experimental exploration provided.


title:
Finite Element Simulation of Light Propagation in Non-Periodic Mask
  Patterns

abstract:
  Rigorous electromagnetic field simulations are an essential part for
scatterometry and mask pattern design. Today mainly periodic structures are
considered in simulations. Non-periodic structures are typically modeled by
large, artificially periodified computational domains. For systems with a large
radius of influence this leads to very large computational domains to keep the
error sufficiently small. In this paper we review recent advances in the
rigorous simulation of isolated structures embedded into a surrounding media.
We especially address the situation of a layered surrounding media (mask or
wafer) with additional infinite inhomogeneities such as resist lines. Further
we detail how to extract the far field information needed for the aerial image
computation in the non-periodic setting.


title: Nonstandard limit theorem for infinite variance functionals

abstract:
  We consider functionals of long-range dependent Gaussian sequences with
infinite variance and obtain nonstandard limit theorems. When the long-range
dependence is strong enough, the limit is a Hermite process, while for weaker
long-range dependence, the limit is $\alpha$-stable L\'{e}vy motion. For the
critical value of the long-range dependence parameter, the limit is a sum of a
Hermite process and $\alpha$-stable L\'{e}vy motion.


title:
Option pricing under stochastic volatility: the exponential
  Ornstein-Uhlenbeck model

abstract:
  We study the pricing problem for a European call option when the volatility
of the underlying asset is random and follows the exponential
Ornstein-Uhlenbeck model. The random diffusion model proposed is a
two-dimensional market process that takes a log-Brownian motion to describe
price dynamics and an Ornstein-Uhlenbeck subordinated process describing the
randomness of the log-volatility. We derive an approximate option price that is
valid when (i) the fluctuations of the volatility are larger than its normal
level, (ii) the volatility presents a slow driving force toward its normal
level and, finally, (iii) the market price of risk is a linear function of the
log-volatility. We study the resulting European call price and its implied
volatility for a range of parameters consistent with daily Dow Jones Index
data.


title: Universal cumulants of the current in diffusive systems on a ring

abstract:
  We calculate exactly the first cumulants of the integrated current and of the
activity (which is the total number of changes of configurations) of the
symmetric simple exclusion process (SSEP) on a ring with periodic boundary
conditions. Our results indicate that for large system sizes the large
deviation functions of the current and of the activity take a universal scaling
form, with the same scaling function for both quantities. This scaling function
can be understood either by an analysis of Bethe ansatz equations or in terms
of a theory based on fluctuating hydrodynamics or on the macroscopic
fluctuation theory of Bertini, De Sole, Gabrielli, Jona-Lasinio and Landim.


title: The Calogero-Moser partition for wreath products

abstract:
  This paper has been withdrawn - the results (with updated proofs) now appear
in arXiv:0801.1627.


title: Wall-Crossings in Toric Gromov-Witten Theory II: Local Examples

abstract:
  In this paper we analyze six examples of birational transformations between
toric orbifolds: three crepant resolutions, two crepant partial resolutions,
and a flop. We study the effect of these transformations on genus-zero
Gromov-Witten invariants, proving the Coates-Corti-Iritani-Tseng/Ruan form of
the Crepant Resolution Conjecture in each case. Our results suggest that this
form of the Crepant Resolution Conjecture may also hold for more general
crepant birational transformations. They also suggest that Ruan's original
Crepant Resolution Conjecture should be modified, by including appropriate
"quantum corrections", and that there is no straightforward generalization of
either Ruan's original Conjecture or the Cohomological Crepant Resolution
Conjecture to the case of crepant partial resolutions. Our methods are based on
mirror symmetry for toric orbifolds.


title: A note on Pollard's Theorem

abstract:
  Let $A,B$ be nonempty subsets of a an abelian group $G$. Let $N_i(A,B)$
denote the set of elements of $G$ having $i$ distinct decompositions as a
product of an element of $A$ and an element of $B$. We prove that $$ \sum
_{1\le i \le t} |N_i (A,B)|\ge t(|A|+|B|- t-\alpha+1+w)-w, $$ where $\alpha $
is the largest size of a coset contained in $AB$ and $w=\min (\alpha-1,1)$,
with a strict inequality if $\alpha\ge 3$ and $t\ge 2$, or if $\alpha\ge 2$ and
$t= 2$.
  This result is a local extension of results by Pollard and Green--Ruzsa and
extends also for $t>2$ a recent result of Grynkiewicz, conjectured by
Dicks--Ivanov (for non necessarily abelian groups) in connection to the famous
Hanna Neumann problem in Group Theory.


title:
The smallest free-electron sphere sustaining multipolar surface plasmon
  oscillation

abstract:
  We study the oscillation frequencies and radiative decay rates of surface
plasmon modes of a simple-metal sphere as a function of sphere radius without
any assumptions concerning the sphere size. We re-examine within the framework
of classical electrodynamics the usual expectations for multipolar plasmon
frequency in the so called "low radius limit" of the classical picture.


title: Braneworld black holes

abstract:
  In these lectures, I give an introduction to and overview of braneworlds and
black holes in the context of warped compactifications. I first describe the
general paradigm of braneworlds, and introduce the Randall-Sundrum model. I
discuss braneworld gravity, both using perturbation theory, and also non
perturbative results. I then discuss black holes on the brane, the obstructions
to finding exact solutions, and ways of tackling these difficulties. I describe
some known solutions, and conclude with some open questions and controversies.


title:
Volume preserving subgroups of A and K and singularities in unimodular
  geometry

abstract:
  For a germ of a smooth map f and a subgroup G_V of any of the Mather groups G
for which the source or target diffeomorphisms preserve some given volume form
V in the source or in the target we study the G_V-moduli space of f that
parameterizes the G_V-orbits inside the G-orbit of f. We find, for example,
that this moduli space vanishes for A-equivalence with volume-preserving target
diffeomorphisms and A-stable maps f and for K-equivalence with
volume-preserving source diffeomorphisms and K-simple maps f. On the other
hand, there are A-stable maps f with infinite-dimensional moduli space for
A-equivalence with volume-preserving source diffeomorphisms.


title: NLO BFKL at work: the electroproduction of two light vector mesons

abstract:
  The forward electroproduction of two light vector mesons is the first example
of a collision process between strongly interacting colorless particles for
which the amplitude can be written completely within perturbative QCD in the
Regge limit with next-to-leading accuracy. This amplitude can be written as a
convolution of two impact factors for the virtual photon to light vector meson
transition with the BFKL Green's function. In this lecture we first describe
how the relevant impact factor is calculated, then we perform the convolution
with the BFKL Green's function and illustrate the numerical procedure to obtain
a well-behaved amplitude.


title: Exact results for topological strings on resolved Y(p,q) singularities

abstract:
  We obtain exact results in \alpha' for open and closed A-model topological
string amplitudes on a large class of toric Calabi-Yau threefolds by using
their correspondence with five dimensional gauge theories. The toric
Calabi-Yau's that we analyze are obtained as minimal resolution of cones over
Y(p,q) manifolds and give rise via M-theory compactification to SU(p) gauge
theories on R^4 x S^1. As an application we present a detailed study of the
local F_2 case and compute open and closed genus zero Gromov-Witten invariants
of the C^3/Z_4 orbifold. We also display the modular structure of the
topological wave function and give predictions for higher genus amplitudes.The
mirror curve in this case is the spectral curve of the relativistic A_1 Toda
chain. Our results also indicate the existence of a wider class of relativistic
integrable systems associated to generic Y(p,q) geometries.


title: Photon momentum in surface plasmon

abstract:
  A momentum of the photon in a surface plasmon could be hundreds and even
thousand times higher as compared to a momentum of a photon in a free space.
Such a photon could be scattered on an electron the later being supplied by a
notable momentum. This momentum is approximately of the same value as a
momentum transposed by an X-ray photon. A physical fundamental importance of
the observation is outlined. Various practical applications of the phenomenon
are proposed including an optical nanodevice.


title: Correlation Effects in Ultracold Two-Dimensional Bose Gases

abstract:
  We study various properties of an ultracold two-dimensional (2D) Bose gas
that are beyond a mean-field description. We first derive the effective
interaction for such a system as realized in current experiments, which
requires the use of an energy dependent $T$-matrix. Using this result, we then
solve the mean-field equation of state of the modified Popov theory, and
compare it with the usual Hartree-Fock theory. We show that even though the
former theory does not suffer from infrared divergences in both the normal and
superfluid phases, there is an unphysical density discontinuity close to the
Berezinskii-Kosterlitz-Thouless transition. We then improve upon the mean-field
description by using a renormalization group approach and show how the density
discontinuity is resolved. The flow equations in two dimensions, in particular,
of the symmetry-broken phase, already contain some unique features pertinent to
the 2D XY model, even though vortices have not been included explicitly. We
also compute various many-body correlators, and show that correlation effects
beyond the Hartree-Fock theory are important already in the normal phase as
criticality is approached. We finally extend our results to the inhomogeneous
case of a trapped Bose gas using the local-density approximation and show that
close to criticality, the renormalization group approach is required for the
accurate determination of the density profile.


title:
The status of the KSS bound and its possible violations (How perfect can
  a fluid be?)

abstract:
  In this work we briefly review the Kovtun-Son-Starinet (KSS) computation of
the ratio eta/s for quantum field theories with gravitational dual and the
related conjecture that it is bound from below by 1/(4 pi). We discuss the
validity of the bound and the nature of its possible violations, its relevance
for RHIC, its connection with phase transitions and other related issues.


title: On Pointed Hopf Algebras with Weyl Groups of exceptional type

abstract:
  All -1-type pointed Hopf algebras and central quantum linear spaces with Weyl
groups of exceptional type are found. It is proved that every non -1-type
pointed Hopf algebra with real $G(H)$ is infinite dimensional and every central
quantum linear space over finite group is finite dimensional. It is proved that
except a few cases Nichols algebras of reducible Yetter-Drinfeld modules over
  Weyl groups of exceptional type are infinite dimensional.


title:
Transport Model Simulations of Projectile Fragmentation Reactions at 140
  MeV/nucleon

abstract:
  The collisions in four different reaction systems using $^{40,48}$Ca and
$^{58,64}$Ni isotope beams and a Be target have been simulated using the Heavy
Ion Phase Space Exploration and the Antisymmetrized Molecular Dynamics models.
The present study mainly focuses on the model predictions for the excitation
energies of the hot fragments and the cross sections of the final fragments
produced in these reactions. The effects of various factors influencing the
final fragment cross sections, such as the choice of the statistical decay code
and its parameters have been explored. The predicted fragment cross sections
are compared to the projectile fragmentation cross sections measured with the
A1900 mass separator. At $E/A=140$ MeV, reaction dynamics can significantly
modify the detection efficiencies for the fragments and make them different
from the efficiencies applied to the measured data reported in the previous
work. The effects of efficiency corrections on the validation of event
generator codes are discussed in the context of the two models.


title: Interferometry Basics in Practice: Exercises

abstract:
  The following exercises aim to learn the link between the object intensity
distribution and the corresponding visibility curves of a long-baseline ptical
interferometer. They are also intended to show the additional constraints on
observability that an interferometer has. This practical session is meant to be
carried out with the ASPRO software, from the Jean-Marie Mariotti Center, but
can also be done using other observation preparation software, such as viscalc
from ESO. There are two main parts with series of exercises and the exercises
corrections. The first one aims at understanding the visibility and its
properties by practicing with simple examples, and the second one is about UV
coverage.


title:
Efficient computation of high index Sturm-Liouville eigenvalues for
  problems in physics

abstract:
  Finding the eigenvalues of a Sturm-Liouville problem can be a computationally
challenging task, especially when a large set of eigenvalues is computed, or
just when particularly large eigenvalues are sought. This is a consequence of
the highly oscillatory behaviour of the solutions corresponding to high
eigenvalues, which forces a naive integrator to take increasingly smaller
steps. We will discuss some techniques that yield uniform approximation over
the whole eigenvalue spectrum and can take large steps even for high
eigenvalues. In particular, we will focus on methods based on coefficient
approximation which replace the coefficient functions of the Sturm-Liouville
problem by simpler approximations and then solve the approximating problem. The
use of (modified) Magnus or Neumann integrators allows to extend the
coefficient approximation idea to higher order methods.


title:
Far-infrared signature of the superconducting gap in intercalated
  graphite CaC6

abstract:
  Terahertz reflectance spectra of the Ca-intercalated graphite CaC6 reveal a
superconducting gap below 11K. The gap signature lacks a sharp onset to full
reflectivity at 2Delta, but rather shows a distribution of gap values
consistent with an anisotropic gap. The experimental data were successfully
fitted to the gap distribution obtained from density functional calculations by
Sanna et al. (Phys.Rev. B75, 020511, 2007). The temperature dependence of the
superconducting gap is characteristic for a BCS type superconductor.


title:
Fe and Al Abundances for 180 Red Giants in the Globular Cluster Omega
  Centauri (NGC 5139)

abstract:
  We present radial velocities, Fe, and Al abundances for 180 red giant branch
(RGB) stars in the Galactic globular cluster Omega Centauri ($\omega$ Cen). The
majority of our data lie in the range 11.0$<$V$<$13.5, which covers the RGB
from about 1 mag. above the horizontal branch to the RGB tip. The selection
procedures are biased towards preferentially observing the more metal--poor and
luminous stars of $\omega$ Cen. Abundances were determined using equivalent
width measurements and spectrum synthesis analyses of moderate resolution
spectra (R$\approx$13,000) obtained with the Blanco 4m telescope and Hydra
multifiber spectrograph. Our results are in agreement with previous studies as
we find at least four different metallicity populations with [Fe/H]=--1.75,
--1.45, --1.05, and --0.75, with a full range of --2.20$\la$[Fe/H]$\la$--0.70.
[Al/Fe] ratios exhibit large star--to--star scatter for all populations, with
the more than 1.0 dex range of [Al/Fe] decreasing for stars more metal--rich
than [Fe/H]$\sim$--1.4. The minimum [Al/Fe] abundance observed for all
metallicity populations is [Al/Fe]$\sim$+0.15. The maximum abundance of log
$\epsilon$(Al) is reached for stars with [Fe/H]$\sim$--1.4 and does not
increase further with stellar metallicity. We interpret these results as
evidence for type II SNe providing the minimum [Al/Fe] ratio and a mass
spectrum of intermediate mass asymptotic giant branch stars causing the
majority of the [Al/Fe] scatter. These results seem to fit in the adopted
scheme that star formation occurred in $\omega$ Cen over $>$1 Gyr.


title:
Construction of Local Conservation Laws by Generalized Isometric
  Embeddings of Vector Bundles

abstract:
  This article uses Cartan-K\"ahler theory to construct local conservation laws
from covariantly closed vector valued differential forms, objects that can be
given, for example, by harmonic maps between two Riemannian manifolds. We apply
the article's main result to construct conservation laws for covariant
divergence free energy-momentum tensors. We also generalize the local isometric
embedding of surfaces in the analytic case by applying the main result to
vector bundles of rank two over any surface.


title: Anderson localization of a non-interacting Bose-Einstein condensate

abstract:
  One of the most intriguing phenomena in physics is the localization of waves
in disordered media. This phenomenon was originally predicted by Anderson,
fifty years ago, in the context of transport of electrons in crystals. Anderson
localization is actually a much more general phenomenon, and it has been
observed in a large variety of systems, including light waves. However, it has
never been observed directly for matter waves. Ultracold atoms open a new
scenario for the study of disorder-induced localization, due to high degree of
control of most of the system parameters, including interaction. Here we employ
for the first time a noninteracting Bose-Einstein condensate to study Anderson
localization. The experiment is performed with a onedimensional quasi-periodic
lattice, a system which features a crossover between extended and exponentially
localized states as in the case of purely random disorder in higher dimensions.
Localization is clearly demonstrated by investigating transport properties,
spatial and momentum distributions. We characterize the crossover, finding that
the critical disorder strength scales with the tunnelling energy of the atoms
in the lattice. Since the interaction in the condensate can be controlled at
will, this system might be employed to solve open questions on the interplay of
disorder and interaction and to explore exotic quantum phases.


title: Phase diagram and binding energy of interacting Bose gases

abstract:
  From the many-body T-matrix the condition for a medium-dependent bound state
and its binding energy is derived for a homogeneous interacting Bose gas. This
condition provides the critical line in the phase diagram in terms of the
medium-dependent scattering length. Separating the Bose pole from the
distribution function the influence of a Bose condensate is discussed and a
thermal minimum of the critical scattering length is found.


title: A Maxwell's demon in the generation of an intense and slow guided beam

abstract:
  We analyze quantitatively the generation of a continuous beam of atoms by the
periodic injection of individual packets in a guide, followed by their
overlapping. We show that slowing the packets using a moving mirror before
their overlapping enables an optimal gain on the phase space density of the
generated beam. This is interpreted as a Maxwell's demon type strategy as the
experimentalist exploits the information on the position and velocity of the
center of mass of each packet.


title: SLE local martingales in logarithmic representations

abstract:
  A space of local martingales of SLE type growth processes forms a
representation of Virasoro algebra, but apart from a few simplest cases not
much is known about this representation. The purpose of this article is to
exhibit examples of representations where L_0 is not diagonalizable - a
phenomenon characteristic of logarithmic conformal field theory. Furthermore,
we observe that the local martingales bear a close relation with the fusion
product of the boundary changing fields.
  Our examples reproduce first of all many familiar logarithmic representations
at certain rational values of the central charge. In particular we discuss the
case of SLE(kappa=6) describing the exploration path in critical percolation,
and its relation with the question of operator content of the appropriate
conformal field theory of zero central charge. In this case one encounters
logarithms in a probabilistically transparent way, through conditioning on a
crossing event. But we also observe that some quite natural SLE variants
exhibit logarithmic behavior at all values of kappa, thus at all central
charges and not only at specific rational values.


title:
Refining the predictions of supersymmetric CP-violating models: A
  top-down approach

abstract:
  We explore in detail the consequences of the CP-violating phases residing in
the supersymmetric and soft SUSY breaking parameters in the approximation that
family flavour mixings are ignored. We allow for non-universal boundary
conditions and in such a consideration the model is described by twelve
independent CP-violating phases and one angle which misaligns the vacuum
expectation values (VEVs) of the Higgs scalars. We run two-loop renormalization
group equations (RGEs), for all parameters involved, including phases, and we
properly treat the minimization conditions using the one-loop effective
potential with CP-violating phases included. We show that the two-loop running
of phases may induce sizable effects for the electric dipole moments (EDMs)
that are absent in the one-loop RGE analysis. Also important corrections to the
EDMs are induced by the Higgs VEVs misalignment angle which are sizable in the
large tanb region. Scanning the available parameter space we seek regions
compatible with accelerator and cosmological data with emphasis on rapid
neutralino annihilations through a Higgs resonance. It is shown that large
CP-violating phases, as required in Baryogenesis scenarios, can be tuned to
obtain agreement with WMAP3 cold dark matter constraints, EDMs and all
available accelerator data, in extended regions of the parameter space which
may be accessible to LHC.


title: Augmenting Actual Life Through MUVEs

abstract:
  The necessity of supporting more and more social interaction (and not only
the mere information sharing) in online environments is the disruptive force
upon which phenomena ascribed to the Web2.0 paradigm continuously bud. People
interacting in online socio-technical environments mould technology on their
needs, seamlessly integrating it into their everyday life. MUVEs (Multi User
Virtual Environments) are no exception and, in several cases, represent the new
frontier in this field. In this work we analyze if and how MUVEs can be
considered a mean for augmenting communities (and more in general people) life.
We trace a framework of analysis based on four main observations, and through
these lenses we look at Second Life and at several projects we are currently
developing in that synthetic world.


title:
The role of Kelvin-Helmholtz instability in dusty and partially ionized
  outflows

abstract:
  We investigate the linear theory of Kelvin-Helmholtz instability at the
interface between a partially ionized dusty outflow and the ambient material
analytically. We model the interaction as a multifluid system in a planar
geometry. The unstable modes are independent from the charge polarity of the
dust particles. Although our results show a stabilizing effect for charged dust
particles, the growth time scale of the growing modes gradually becomes
independent of the mass or charge of the dust particles when the magnetic field
strength increases. We show that growth time scale decreases with increasing
the magnetic field. Also, as the mass of the dust particles increases, the
growth time scale of the unstable mode increases.


title:
Shape transition under excess self-intersections for transient random
  walk

abstract:
  We reveal a shape transition for a transient simple random walk forced to
realize an excess $q$-norm of the local times, as the parameter $q$ crosses the
value $q_c(d)=\frac{d}{d-2}$. Also, as an application of our approach, we
establish a central limit theorem for the $q$-norm of the local times in
dimension 4 or more.


title: Type I background fields in terms of type IIB ones

abstract:
  We choose such boundary conditions for open IIB superstring theory which
preserve N=1 SUSY. The explicite solution of the boundary conditions yields
effective theory which is symmetric under world-sheet parity transformation
$\Omega:\sigma\to-\sigma$. We recognize effective theory as closed type I
superstring theory. Its background fields,beside known $\Omega$ even fields of
the initial IIB theory, contain improvements quadratic in $\Omega$ odd ones.


title: Dilepton production as a measure of QGP thermalization time

abstract:
  We discuss dilepton production from a quark-gluon plasma which has a
time-dependent anisotropy in momentum space. A phenomenological model for the
hard momentum scale, p_hard(tau) and the plasma anisotropy parameter, xi(tau),
is presented. The model interpolates between early-time 1+1 free streaming
behavior (tau << tau_iso) and late-time ideal 1+1 hydrodynamical behavior (tau
>> tau_iso). Using this model, we find that the dilepton rate arising from
electromagnetic annihilations of quarks in the kinematic range 3 <p_T< 8 GeV is
sensitive to the assumed isotropization time of the system, tau_iso. Therefore
high-energy dilepton production can be used to probe the degree of
momentum-space isotropy of a quark-gluon plasma produced in relativistic heavy
ion collisions and the time of onset of hydrodynamic expansion of the QGP.


title: Quasiflats in CAT(0) complexes

abstract:
  We show that if X is a piecewise Euclidean 2-complex with a cocompact
isometry group, then every 2-quasiflat in X is at finite Hausdorff distance
from a subset which is locally flat outside a compact set, and asymptotically
conical.


title:
Low and high frequency approximations to eigenvibrations of string with
  double contrasts

abstract:
  We study eigenvibrations for inhomogeneous string consisting of two parts
with strongly contrasting stiffness and mass density. In this work we treat a
critical case for the high frequency approximations, namely the case when the
order of mass density inhomogeneity is the same as the order of stiffness
inhomogeneity, with heavier part being softer. The limit problem for high
frequency approximations depends nonlinearly on the spectral parameter. The
quantization of the spectral semiaxies is applied in order to get a close
approximations of eigenvalues as well as eigenfunctions for the prime problem
under perturbation.


title:
Design and Implementation of a Master of Science in Information and
  Computer Sciences - An Inventory and retrospect for the last four years

abstract:
  This Master of Science in Computer and Information Sciences (MICS) is an
international accredited master program that has been initiated in 2004 and
started in September 2005. MICS is a research-oriented academic study of 4
semesters and a continuation of the Bachelor towards the PhD. It is completely
taught in English, supported by lecturers coming from more than ten different
countries. This report compass a description of its underlying architecture,
describes some implementation details and gives a presentation of diverse
experiences and results. As the program has been designed and implemented right
after the creation of the University, the significance of the program is
moreover a self-discovery of the computer science department, which has finally
led to the creation of the today's research institutes and research axes.


title: The Horizontal Symmetry for Neutrino Mixing

abstract:
  We argue that the best way to determine horizontal symmetry is from neutrino
mixing, and proceed to show that the only finite group capable of yielding the
tri-bimaximal mixing for all Yukawa couplings is $S_4$, or any group containing
it. The method used is largely group theoretical, but it can be implemented by
dynamical schemes in which the Higgs expectation values introduced to break
$S_4$ spontaneously are uniquely determined up to an unknown scale for each.