title:
Prospects and pitfalls of gravitational lensing in large supernova
  surveys

abstract:
  To investigate the effect of gravitational lensing of supernovae in large
ongoing surveys, we simulate the effect of gravitational lensing magnification
on individual supernovae using observational data input from two large
supernova surveys. To estimate the magnification due to matter in the
foreground, we simulate galaxy catalogs and compute the magnification along
individual lines of sight using the multiple lens plane algorithm. The dark
matter haloes of the galaxies are modelled as gravitational lenses using
singular isothermal sphere or Navarro-Frenk-White profiles. Scaling laws
between luminosity and mass, provided by Faber-Jackson and Tully-Fisher
relations, are used to estimate the masses of the haloes.
  While our simulations show that the SDSSII supernova survey is marginally
affected by gravitational lensing, we find that the effect will be measurable
in the SNLS survey that probes higher redshifts. Our simulations show that the
probability to measure a significant (3 sigma) correlation between the Hubble
diagram residuals and the calculated lensing magnification is ~95% in the SNLS
data. Moreover, with this data it should be possible to constrain the
normalisation of the masses of the lensing galaxy haloes at the 1 sigma and 2
sigma confidence level with ~30% and ~60% accuracy, respectively.


title:
Radial thermal expansion of single-walled carbon nanotube bundles at low
  temperatures

abstract:
  The linear coefficient of the radial thermal expansion has been measured on a
system of SWNT bundles in an interval of 2.2 - 120K. The measurement was
performed using a dilatometer with a sensitivity of 2*10-9 cm. The cylindrical
sample 7 mm high and 10 mm in diameter was obtained by compressing powder. The
resulting bundles of the nanotubes were oriented perpendicular to the sample
axis. The starting powder contained over 90% of SWNTs with the outer diameter
1.1 nm, the length varying within 5-30 um.


title:
Implications of the anomalous top quark couplings in $B_s-\bar{B}_s$
  mixing, $B \to X_s \gamma$ and top quark decays

abstract:
  Combined analysis of recent measured $\bs$ mixing and $B \to X_s \gamma$
decays provides constraints on the anomalous $\bar{t}sW$ couplings. We discuss
the perspectives to examine the anomalous $\bar{t}sW$ couplings through
CKM-suppressed $ t \to s W$ decays at the LHC.


title:
On the non-existence of some Steiner $t$-$(v,k)$ trades of certain
  volumes

abstract:
  Mahmoodian and Soltankhah $\cite{MMS}$ conjectured that there does not exist
any $t$-$(v,k)$ trade of volume $s_{i}< s <s_{i+1}$, where
$s_{i}=2^{t+1}-2^{t-i}, i=0,1,..., t-1$. Also they showed that the conjecture
is true for $i=0$. In this paper we prove the correctness of this conjecture
for Steiner trades.


title: Thin shell wormhole due to dyadosphere of a charged black hole

abstract:
  To explain Gamma Ray Bursts, Ruffini argued that the event horizon of a
charged black hole is surrounded by a special region called, the Dyadosphere
where electric field exceeds the critical value for $e^+$ $e^-$ pair
production. In the present work, we construct a thin shell wormhole by
performing a thought surgery between two dadospheres. Several physical
properties of this thin shell wormhole have been analyzed.


title: Real-time synchronization feedbacks for single-atom frequency standards

abstract:
  Simple feedback loops, inspired from extremum-seeking, are proposed to lock a
probe-frequency to the transition frequency of a single quantum system
following quantum Monte-Carlo trajectories. Two specific quantum systems are
addressed, a 2-level one and a 3-level one that appears in coherence population
trapping and optical pumping. For both systems, the feedback algorithm is shown
to be convergent in the following sense: the probe frequency converges in
average towards the system-transition one and its standard deviation can be
made arbitrarily small. Closed-loop simulations illustrate robustness versus
jump-detection efficiency and modeling errors.


abstract:
  For general non-symmetric operators $A$, we prove that the moment of order
$\gamma \ge 1$ of negative real-parts of its eigenvalues is bounded by the
moment of order $\gamma$ of negative eigenvalues of its symmetric part $H =
{1/2} [A + A^*].$ As an application, we obtain Lieb-Thirring estimates for non
self-adjoint Schr\"odinger operators. In particular, we recover recent results
by Frank, Laptev, Lieb and Seiringer \cite{FLLS}. We also discuss moment of
resonances of Schr\"odinger self-adjoint operators.


title:
NLO QCD corrections to the production of a weak boson pair associated by
  a hard jet

abstract:
  In this talk we discuss recent progress concerning precise predictions for
the LHC. We give a status report of an application of the GOLEM method to deal
with multi-leg one-loop amplitudes, namely the next-to-leading order QCD
corrections to the process pp to V V + jet, where V is a weak boson W,Z.


title: Constructing regular graphs with smallest defining number

abstract:
  In a given graph $G$, a set $S$ of vertices with an assignment of colors is a
{\sf defining set of the vertex coloring of $G$}, if there exists a unique
extension of the colors of $S$ to a $\Cchi(G)$-coloring of the vertices of $G$.
A defining set with minimum cardinality is called a {\sf smallest defining set}
(of vertex coloring) and its cardinality, the {\sf defining number}, is denoted
by $d(G, \Cchi)$. Let $ d(n, r, \Cchi = k)$ be the smallest defining number of
all $r$-regular $k$-chromatic graphs with $n$ vertices. Mahmoodian et. al
\cite{rkgraph} proved that, for a given $k$ and for all $n \geq 3k$, if $r \geq
2(k-1)$ then $d(n, r, \Cchi = k)=k-1$. In this paper we show that for a given
$k$ and for all $n < 3k$ and $r\geq 2(k-1)$, $d(n, r, \Cchi=k)=k-1$.


title:
Black objects in the Einstein-Gauss-Bonnet theory with negative
  cosmological constant and the boundary counterterm method

abstract:
  We propose to compute the action and global charges of the asymptotically
anti-de Sitter solutions in Einstein-Gauss-Bonnet theory by adding boundary
counterterms to the gravitational action. The general expression of the
counterterms and the boundary stress tensor is presented for spacetimes of
dimension $d\leq 9$. We apply this tehnique for several different types of
black objects. Apart from static and rotating black holes, we consider also
Einstein-Gauss-Bonnet black string solutions with negative cosmological
constant.


title: The Improvement of the Bound on Hash Family

abstract:
  In this paper, we study the bound on three kinds of hash family using the
Singleton bound. To $\epsilon-U(N; n, m)$ hash family, in the caes of $n>m^2>1$
and $1\geq\epsilon\geq \epsilon_1(n, m)$, we get that the new bound is better.
To $\epsilon-\bigtriangleup U(N; n, m)$ hash family, in the case of $n>m>1$ and
$1\geq\epsilon\geq\epsilon_3(n,m)$, the new bound is better. To $\epsilon-SU(N;
n, m)$ hash family, in the case of $n>2^m>2$ and $1\geq\epsilon\geq
\epsilon_4(n, m)$, we get that the new bound is better.


title:
Some Divisibility Properties in Ring of Polynomials over a Unique
  Factorization Domain

abstract:
  Using polynomial evaluation, we give some useful criteria to answer questions
about divisibility of polynomials. This allows us to develop interesting
results concerning the prime elements in the domain of coefficients. In
particular, it is possible to prove that under certain conditions, the domain
of coefficients must have infinitely many prime elements. We give alternative
characterizations for D-rings and present various examples.


title: Viscous Dark Cosmology with Account of Quantum Effects

abstract:
  The analytic properties of the energy density rho(t) of the cosmic fluid, and
the Hubble parameter H(t), are investigated near to the future singularity
t=t_s assuming different forms for the equation of state. First, it is shown
that the inclusion of quantum effects coming from the conformal anomaly
modifies the singularity. Thereafter, we consider the effect coming from a bulk
viscosity in the fluid. The viscosity tends to reduce the magnitude of t_s, but
does not alter the singularity itself (the exponent). Main emphasis is laid on
the simple case when the equation of state is p=w*rho, with w a constant.


title: Supercooled Liquid Dynamics Studied via Shear-Mechanical Spectroscopy

abstract:
  We report dynamical shear-modulus measurements for five glass-forming liquids
(pentaphenyl trimethyl trisiloxane, diethyl phthalate, dibutyl phthalate,
1,2-propanediol, and m-touluidine). The shear-mechanical spectra are obtained
by the piezoelectric shear-modulus gauge (PSG) method. This technique allows
one to measure the shear modulus ($10^{5} -10^{10}$ Pa) of the liquid within a
frequency range from 1 mHz to 10 kHz. We analyze the frequency-dependent
response functions to investigate whether time-temperature superposition (TTS)
is obeyed. We also study the shear-modulus loss-peak position and its
high-frequency part. It has been suggested that when TTS applies, the
high-frequency side of the imaginary part of the dielectric response decreases
like a power law of the frequency with an exponent -1/2. This conjecture is
analyzed on the basis of the shear mechanical data. We find that TTS is obeyed
for pentaphenyl trimethyl trisiloxane and in 1,2-propanediol while in the
remaining liquids evidence of a mechanical $\beta$ process is found. Although
the the high-frequency power law behavior $\omega^{-\alpha}$ of the shear-loss
may approach a limiting value of $\alpha=0.5$ when lowering the temperature, we
find that the exponent lies systematically above this value (around 0.4). For
the two liquids without beta relaxation (pentaphenyl trimethyl trisiloxane and
1,2-propanediol) we also test the shoving model prediction, according to which
the the relaxation-time activation energy is proportional to the instantaneous
shear modulus. We find that the data are well described by this model.


title: A remark on the rational cohomology of $\bar{S}_{1,n}$

abstract:
  We focus on the rational cohomology of Cornalba's moduli space of spin curves
of genus 1 with $n$ marked points. In particular, we show that both its first
and its third cohomology group vanish and the second cohomology group is
generated by boundary classes.


title: Synchronization of coupled anizochronous oscillators

abstract:
  The particular properties of synchronization are discussed for the system of
coupled van der Pol - Duffing oscillators. The arrangement of synchronization
tongues and the particular properties of their internal structure in the
parameter space are revealed. The features of attractors in the phase space and
in the Poincare section are considered.


title: New Upper Bound for the Edge Folkman Number Fe(3,5;13)

abstract:
  In this paper we prove that the edge Folkman number Fe(3,5;13) is not greater
than 21.


title: Imprinting bias stress in functional composites

abstract:
  We propose a simple yet effective method which allows one to attain large
reversible shape changes in shape memory bimetallic composites without training
procedure. It is based on the conservation of strongly anisotropic martensite
microstructure artificially created in the shape memory layer. This procedure
results in appearance of stress field when the shape memory layer is
transformed to the austenitic state which brings about two-way shape memory
effect. Utilization of this method for preparation of TiNi-based composite with
a thickness of 60 \mu m allowed us to achieve 0.9% reversible bending
deformation. It is also suggested that the implementation of this method during
preparation of piezoelectric or magnetostrictive composites permits to imprint
bias stress and thus to improve their characteristics without use of an
external load.


title:
The complementary polynomials and the Rodrigues operator. A
  distributional study

abstract:
  We can write the polynomial solution of the second order linear differential
equation of hypergeometric-type $$ \phi(x)y''+\psi(x)y'+\lambda y=0, $$ where
$\phi$ and $\psi$ are polynomials, $\deg \phi\le 2$, $\deg \psi=1$ and
$\lambda$ is a constant, among others, by using the Rodrigues operator
$R_k(\phi,{\bf u})$ (see \cite{coma2}) where $\bf u$ is certain linear operator
which satisfies the distributional equation \begin{equation} \label{1}
\frac{d}{dx}[\phi {\bf u}]=\psi {\bf u}, \end{equation} as $$ P_n(x)=B_n
R_n(\phi,{\bf u})[1], \qquad B_n\ne 0,\quad n=0, 1, 2, ... $$ Taking this into
account we construct the complementary polynomials. Among the key results is a
generating functional function in closed form leading to derivations of
recursion relations and addition theorem. The complementary polynomials satisfy
a hypergeometric-type differential equation themselves, have a three-term
recursion among others and Rodrigues formulas.


title: Ram pressure stripping in a viscous intracluster medium

abstract:
  In the recent literature there is circumstantial evidence that the viscosity
of the intracluster medium may not be too far from the Spitzer value. In this
letter, we present two-dimensional hydrodynamical simulations of ram pressure
stripping of disc galaxies in a viscous intracluster medium. The values of
viscosity explored range between 0.1 and 1.0 times the Spitzer value. We find
that viscosity affects the appearance and the dimensions of the galactic wakes
but has very little effect on the evolution of the gas mass of the galaxy.


title: Graphene/Ni(111) System: Spin- and Angle-Resolved Photoemission Studies

abstract:
  Here we report spin- and angle-resolved photoemission studies of the inert
graphene layer formed on the surface of a ferromagnetic material, Ni(111).
X-ray photoemission and spin-resolved spectroscopy of secondary electrons
reveal that graphene behaves like a protection layer on the Ni(111) surface
preventing its reaction with adsorbed oxygen. Angle-resolved photoelectron
spectroscopy of $\pi$ states of graphene on Ni(111) shows a strong dependence
of binding energy of these states on the direction of magnetization of the
sample. We conclude that the observed extraordinary high "splitting" up to 225
meV of the $\pi$ band in the graphene layer is a manifes-tation of the Rashba
effect which provides a direct possibility to a flexible control of an electron
spin in a graphene-based spin-FET.


title:
Equivalent Definitions for Uniform Exponential Trichotomy of Evolution
  Operators in Banach Spaces

abstract:
  The aim of this paper is to give necessary and sufficient conditions for the
uniform exponential trichotomy property of nonlinear evolution operators in
Banach spaces. The obtained results are generalizations for
infinite-dimensional case of some well-known results of Elaydi and Hajek on
exponential trichotomy of differential systems.


title: Nonuniform Behaviors for Skew-Evolution Semiflows in Banach Spaces

abstract:
  The paper emphasizes some asymptotic behaviors for skew-evolution semiflows
in Banach spaces. These are defined by means of evolution semiflows and
evolution cocycles. Some characterizations which generalize classical results
are also provided. The approach is from nonuniform point of view.


title: Directed update for the Stochastic Green Function algorithm

abstract:
  In a recent publication (Phys. Rev E 77, 056705 (2008)),we have presented the
stochastic Green function (SGF) algorithm, which has the properties of being
general and easy to apply to any lattice Hamiltonian of the form H=V-T, where V
is diagonal in the chosen occupation number basis and T has only positive
matrix elements. We propose here a modified version of the update scheme that
keeps the simplicity and generality of the original SGF algorithm, and enhances
significantly its efficiency.


title: Ab initio study of bilateral doping within the MoS2-NbS2 system

abstract:
  We present a systematic study on the stability and the structural and
electronic properties of mixed molybdenum-niobium disulphides. Using density
functional theory we investigate bilateral doping with up to 25 % of MoS2
(NbS2) by Nb (Mo) atoms, focusing on the precise arrangement of dopants within
the host lattices. We find that over the whole range of considered
concentrations, Nb doping of MoS2 occurs through a substitutional mechanism.
For Mo in NbS2 both interstitial and substitutional doping can co-exist,
depending upon the particular synthesis conditions. The analysis of the
structural and electronic modifications of the perfect bulk systems due to the
doping is presented. We show that substitutional Nb atoms introduce electron
holes to the MoS2, leading to a semiconductor-metal transition. On the other
hand, the Mo doping of Nb2, does not alter the metallic behavior of the initial
system. The results of the present study are compared with available
experimental data on mixed MoS2-NbS2 (bulk and nanoparticles).


title:
Hydration-induced anisotropic spin fluctuations in
  Na_{x}CoO_{2}\cdot1.3H_{2}O superconductor

abstract:
  We report ^{59}Co NMR studies in single crystals of cobalt oxide
superconductor Na_{0.42}CoO_{2}\cdot1.3H_{2}O (T_c=4.25K) and its parent
compound Na_{0.42}CoO_{2}. We find that both the magnitude and the temperature
(T) dependence of the Knight shifts are identical in the two compounds above
T_c. The spin-lattice relaxation rate (1/T_1) is also identical above T_0
\sim60 K for both compounds. Below T_0, the unhydrated sample is found to be a
non-correlated metal that well conforms to Fermi liquid theory, while spin
fluctuations develop in the superconductor. These results indicate that water
intercalation does not change the density of states but its primary role is to
bring about spin fluctuations. Our result shows that, in the hydrated
superconducting compound, the in-plane spin fluctuation around finite wave
vector is much stronger than that along the c-axis, which indicates that the
spin correlation is quasi-two-dimensional.


title: Topological Complexity of Context-Free omega-Languages: A Survey

abstract:
  We survey recent results on the topological complexity of context-free
omega-languages which form the second level of the Chomsky hierarchy of
languages of infinite words. In particular, we consider the Borel hierarchy and
the Wadge hierarchy of non-deterministic or deterministic context-free
omega-languages. We study also decision problems, the links with the notions of
ambiguity and of degrees of ambiguity, and the special case of omega-powers.


title: Absolute frequency measurement of the 40Ca+ S1/2 - D5/2 clock transition

abstract:
  We report on the first absolute transition frequency measurement at the
10^{-15} level with a single, laser-cooled 40Ca+ ion in a linear Paul trap. For
this measurement, a frequency comb is referenced to the transportable Cs atomic
fountain clock of LNE-SYRTE and is used to measure the S1/2-D5/2
electric-quadrupole transition frequency. After the correction of systematic
shifts, the clock transition frequency f_Ca+ = 411 042 129 776 393.2 (1.0) Hz
is obtained, which corresponds to a fractional uncertainty within a factor of
three of the Cs standard. Future improvements are expected to lead to an
uncertainty surpassing the best Cs fountain clocks. In addition, we determine
the Lande g-factor of the D5/2 level to be gD5/2=1.2003340(3).


title:
TRIS I: Absolute Measurements of the Sky Brightness Temperature at 0.6,
  0.82 and 2.5 GHz

abstract:
  At frequencies close to 1 GHz the sky diffuse radiation is a superposition of
radiation of Galactic origin, the 3 K Relic or Cosmic Microwave Background
Radiation, and the signal produced by unresolved extragalactic sources. Because
of their different origin and space distribution the relative importance of the
three components varies with frequency and depends on the direction of
observation. With the aim of disentangling the components we built TRIS, a
system of three radiometers, and studied the temperature of the sky at $\nu
=0.6$, $\nu = 0.82$ and $\nu = 2.5$ GHz using geometrically scaled antennas
with identical beams (HPBW = $18^{\circ} \times 23^{\circ}$). Observations
included drift scans along a circle at constant declination
$\delta=+42^{\circ}$ which provided the dependence of the sky signal on the
Right Ascension, and absolute measurement of the sky temperature at selected
points along the same scan circle. TRIS was installed at Campo Imperatore (lat.
= $42^{\circ}~26'$ N, long.= $13^{\circ}~33'$, elevation = 2000 m a.s.l.) in
Central Italy, close to the Gran Sasso Laboratory.


title: Highway Hull Revisited

abstract:
  A highway H is a line in the plane on which one can travel at a greater speed
than in the remaining plane. One can choose to enter and exit H at any point.
The highway time distance between a pair of points is the minimum time required
to move from one point to the other, with optional use of H.
  The highway hull HH(S,H) of a point set S is the minimal set containing S as
well as the shortest paths between all pairs of points in HH(S,H), using the
highway time distance.
  We provide a Theta(n log n) worst-case time algorithm to find the highway
hull under the L_1 metric, as well as an O(n log^2 n) time algorithm for the
L_2 metric which improves the best known result of O(n^2).
  We also define and construct the useful region of the plane: the region that
a highway must intersect in order that the shortest path between at least one
pair of points uses the highway.


title: The Relative Capacity

abstract:
  The purpose of this article is to introduce the relative $p$-capacity
$\Cap_{p,\Omega}$ with respect to an open set $\Omega$ in $\IR^N$. It is a
Choquet capacity on the closure of $\Omega$ and extends the classical
$p$-capacity $\Cap_p$ in the sense that $\Cap_{p,\Omega}=\Cap_p$ if
$\Omega=\IR^N$. The importance of the relative $p$-capacity stems from the fact
that a large class of Sobolev functions defined on a 'bad domain' admit a trace
on the boundary $\partial\Omega$ which is then unique up to
$\Cap_{p,\Omega}$-polar set. As an application we prove a characterization of
$W^{1,p}_0(\Omega)$ for open sets $\Omega\subset\IR^N$.


title: Magneto-Acoustic Wave Oscillations in Solar Spicules

abstract:
  Some observations suggest that solar spicules show small amplitude and high
frequency oscillations of magneto-acoustic waves, which arise from photospheric
granular forcing. We apply the method of MHD seismology to determine the period
of kink waves. For this purposes, the oscillations of a magnetic cylinder
embedded in a field-free environment is investigated. Finally, diagnostic
diagrams displaying the oscillatory period in terms of some equilibrium
parameters are provided to allow a comparison between theoretical results and
those coming from observations.


title: Time-resolved optical photometry of the ultra-compact binary 4U0614+091

abstract:
  We present a detailed optical study of the ultra-compact X-ray binary
4U0614+091. We have used 63 hrs of time-resolved optical photometry taken with
three different telescopes (IAC80, NOT and SPM) to search for optical
modulations. The power spectra of each dataset reveals sinusoidal modulations
with different periods, which are not always present. The strongest modulation
has a period of 51.3 mins, a semi-amplitude of 4.6 mmags, and is present in the
IAC80 data. The SPM and NOT data show periods of 42 mins and 64 mins
respectively, but with much weaker amplitudes, 2.6 mags and 1.3 mmags
respectively. These modulations arise from either X-ray irradiation of the
inner face of the secondary star and/or a superhump modulation from the
accretion disc, or quasi-periodic modulations in the accretion disc. It is
unclear whether these periods/quasi-periodic modulations are related to the
orbital period, however, the strongest period of 51.3 mins is close to earlier
tentative orbital periods. Further observations taken over a long base-line are
encouraged.


title: Holographic Supergravity Dual to Three Dimensional N=2 Gauge Theory

abstract:
  By examining the previously known holographic N=2 supersymmetric
renormalization group flow solution in four dimensions, we describe the
mass-deformed Bagger-Lambert theory, that has SU(3)_I x U(1)_R symmetry, by the
addition of mass term for one of the four adjoint chiral superfields as its
dual theory. A further detailed correspondence between fields of AdS_4
supergravity and composite operators of the infrared field theory is obtained.


title:
Broadband method for precise microwave spectroscopy of superconducting
  thin films near the critical temperature

abstract:
  We present a high-resolution microwave spectrometer to measure the
frequency-dependent complex conductivity of a superconducting thin film near
the critical temperature. The instrument is based on a broadband measurement of
the complex reflection coefficient, $S_{\rm 11}$, of a coaxial transmission
line, which is terminated to a thin film sample with the electrodes in a
Corbino disk shape. In the vicinity of the critical temperature, the standard
calibration technique using three known standards fails to extract the strong
frequency dependence of the complex conductivity induced by the superconducting
fluctuations. This is because a small unexpected difference between the phase
parts of $S_{\rm 11}$ for a short and load standards gives rise to a large
error in the detailed frequency dependence of the complex conductivity near the
superconducting transition. We demonstrate that a new calibration procedure
using the normal-state conductivity of a sample as a load standard resolves
this difficulty. The high quality performance of this spectrometer, which
covers the frequency range between 0.1 GHz and 10 GHz, the temperature range
down to 10 K, and the magnetic field range up to 1 T, is illustrated by the
experimental results on several thin films of both conventional and high
temperature superconductors.


title:
The classical field created in early stages of high energy
  nucleus-nucleus collisions

abstract:
  We show that a special choice of light-cone gauge can greatly simplify the
calculation of the classical color field created in the initial stages of
nucleus-nucleus collisions. Within this gauge, we can in particular construct
explicitly the conserved color current and calculate exactly the gauge field
immediately after the collision. This field is used as a boundary condition in
an iterative solution of the Yang-Mills equations in the forward light-cone. In
leading order, which corresponds to a linearization of the Yang-Mills equation
in the forward light-cone, we obtain a simple formula for the spectrum of
gluons produced in nucleus-nucleus collisions. This formula reproduces exactly
the known formula for proton-nucleus collisions, where $k_t-$factorization is
recovered, while the latter property apparently breaks down in the case of
nucleus-nucleus collisions.


title: Quasi-co-Frobenius corings as Galois comodules

abstract:
  We compare several quasi-Frobenius-type properties for corings that appeared
recently in literature and provide several new characterizations for each of
these properties. By applying the theory of Galois comodules with a firm
coinvariant ring, we can characterize a locally quasi-Frobenius
(quasi-co-Frobenius) coring as a locally projective generator in its category
of comodules.


title: Smooth Structures and Einstein Metrics on $CP^2#5,6,7\bar{CP^2}$

abstract:
  We show that each of the topological 4-manifolds $CP^2#k\bar{CP^2}, for $k =
6, 7$ admits a smooth structure which has an Einstein metric of scalar
curvature $s > 0$, a smooth structure which has an Einstein metric with $s < 0$
and infinitely many non-diffeomorphic smooth structures which do not admit
Einstein metrics. We show that there are infinitely many manifolds homeomorphic
non-diffeomorphic to $CP^2#5\bar{CP^2}$ which do not admit an Einstein metric.
We also exhibit new higher dimensional examples of manifolds carrying Einstein
metrics of both positive and negative scalar curvature. The main ingredients
are recent constructions of exotic symplectic or complex manifolds with small
topological numbers.


title:
Elemental depth profiling of fluoridated hydroxyapatite by X-ray
  photoelectron spectroscopy

abstract:
  Structural and chemical changes that arise from a fluoridation of synthetic
hydroxyapatite in neutral and acidic fluoridation agents are investigated. For
synthetic hydroxyapatite (Ca5(PO4)3OH = HAp), the elemental depth profiles were
determined by X-ray photoelectron spectroscopy (XPS) to reveal the effect of
fluoridation in nearly neutral (pH = 6.2) and acidic agents (pH = 4.2). Due to
the high surface sensitivity of the technique, the depth profiles have a
resolution on the nm scale. With respect to the chemical composition and the
crystal structure XPS depth profiling revealed very different effects of the
two treatments. In both cases, however, the fluoridation affects the surface
only on the nm scale which is in contrast to recent literature, where a
penetration depth up to several microns was reported. Moreover, evidence is
given that the actual fluoridation depth depends on the pH value. Recently, a
qualitative three layer model was proposed for the fluoridation of HAp in an
acidic agent. In addition to the elemental depth profile, as presented also by
various other authors, we present a quantitative depth profile of the compounds
CaF2, Ca(OH)2 and fluorapatite (FAp) that are predicted by the three layer
model. The analysis of our experimental data exactly reproduces the structural
order of the model, however, on a scale that differs by nearly two orders of
magnitude from previous predictions. Our results also reveal that the amount of
Ca(OH)2 and FAp is small as compared to that of CaF2. Therefore, it has to be
questioned whether such narrow Ca(OH)2 and FAp layers really can act as
protective layers for the enamel.


title: Asymptotically Flat Radiating Solutions in Third Order Lovelock Gravity

abstract:
  In this paper, we present an exact spherically symmetric solution of third
order Lovelock gravity in $n$ dimensions which describes the gravitational
collapse of a null dust fluid. This solution is asymptotically (anti-)de Sitter
or flat depending on the choice of the cosmological constant. Using the
asymptotically flat solution for $n \geq 7$ with a power-law form of the mass
as a function of the null coordinate, we present a model for a gravitational
collapse in which a null dust fluid radially injects into an initially flat and
empty region. It is found that a naked singularity is inevitably formed whose
strength is different for the $n = 7$ and $n \geq 8$ cases. In the $n=7$ case,
the limiting focusing condition for the strength of curvature singularity is
satisfied. But for $n \geq 8$, the strength of curvature singularity depends on
the rate of increase of mass of the spacetime. These considerations show that
the third order Lovelock term weakens the strength of the curvature
singularity.


title: SPH simulations of grain growth in protoplanetary disks

abstract:
  Aims: In order to understand the first stages of planet formation, when tiny
grains aggregate to form planetesimals, one needs to simultaneously model grain
growth, vertical settling and radial migration of dust in protoplanetary disks.
In this study, we implement an analytical prescription for grain growth into a
3D two-phase hydrodynamics code to understand its effects on the dust
distribution in disks. Methods: Following the analytic derivation of Stepinski
& Valageas (1997), which assumes that grains stick perfectly upon collision, we
implement a convenient and fast method of following grain growth in our 3D,
two-phase (gas+dust) SPH code. We then follow the evolution of the size and
spatial distribution of a dust population in a classical T Tauri star disk.
Results: We find that the grains go through various stages of growth due to the
complex interplay between gas drag, dust dynamics, and growth. Grains initially
grow rapidly as they settle to the mid-plane, then experience a fast radial
migration with little growth through the bulk of the disk, and finally pile-up
in the inner disk where they grow more efficiently. This results in a bimodal
distribution of grain sizes. Using this simple prescription of grain growth, we
find that grains reach decimetric sizes in 10^5 years in the inner disk and
survive the fast migration phase.


title: Domains of uniqueness for $C_0$-semigroups on the dual of a Banach space

abstract:
  Let $({\cal X},\|\:.\:\|)$ be a Banach space. In general, for a
$C_0$-semigroup \semi on $({\cal X},\|\:.\:\|)$, its adjoint semigroup \semia
is no longer strongly continuous on the dual space $({\cal
X}^{*},\|\:.\:\|^{*})$. Consider on ${\cal X}^{*}$ the topology of uniform
convergence on compact subsets of $({\cal X},\|\:.\:\|)$ denoted by ${\cal
C}({\cal X}^{*},{\cal X})$, for which the usual semigroups in literature
becomes $C_0$-semigroups. The main purpose of this paper is to prove that only
a core can be the domain of uniqueness for a $C_0$-semigroup on $({\cal
X}^{*},{\cal C}({\cal X}^{*},{\cal X}))$. As application, we show that the
generalized Schr\"odinger operator ${\cal A}^Vf={1/2}\Delta f+b\cdot\nabla
f-Vf$, $f\in C_0^\infty(\R^d)$, is $L^\infty(\R^d,dx)$-unique. Moreover, we
prove the $L^1(\R^d,dx)$-uniqueness of weak solution for the Fokker-Planck
equation associated with ${\cal A}^V$.


title: Magnetic Branes in Third Order Lovelock-Born-Infeld Gravity

abstract:
  Considering both the nonlinear invariant terms constructed by the
electromagnetic field and the Riemann tensor in gravity action, we obtain a new
class of $(n+1)$-dimensional magnetic brane solutions in third order
Lovelock-Born-Infeld gravity. This class of solutions yields a spacetime with a
longitudinal nonlinear magnetic field generated by a static source. These
solutions have no curvature singularity and no horizons but have a conic
geometry with a deficit angle $\delta$. We find that, as the Born-Infeld
parameter decreases, which is a measure of the increase of the nonlinearity of
the electromagnetic field, the deficit angle increases. We generalize this
class of solutions to the case of spinning magnetic solutions and find that,
when one or more rotation parameters are nonzero, the brane has a net electric
charge which is proportional to the magnitude of the rotation parameters.
Finally, we use the counterterm method in third order Lovelock gravity and
compute the conserved quantities of these spacetimes. We found that the
conserved quantities do not depend on the Born-Infeld parameter, which is
evident from the fact that the effects of the nonlinearity of the
electromagnetic fields on the boundary at infinity are wiped away. We also find
that the properties of our solution, such as deficit angle, are independent of
Lovelock coefficients.


title: Early-type objects in NGC6611 and Eagle Nebula

abstract:
  An important question about Be stars is whether Be stars are born as Be stars
or not. It is necessary to observe young clusters to answer this question.
Observations of stars in NGC6611 and the star-formation region of Eagle Nebula
have been carried out with the ESO-WFI in slitless spectroscopic mode and at
the VLT-GIRAFFE. The targets for the GIRAFFE observations were pre-selected
from the literature and our catalogue of emission-line stars (ELS) based on the
WFI study. GIRAFFE observations allowed us to study accurately the population
of the early-type stars with and without emission lines. For this study, we
determined the fundamental parameters of OBA stars. We also studied the status
of the objects (main sequence or pre-main sequence stars) by using IR data,
membership probabilities, and location in HR diagrams. The nature of the
early-type ELS in M16 is derived. The slitless observations with the WFI
clearly indicate a small number of ELS in M16. We observed with GIRAFFE 101 OBA
stars, among them 9 are ELS with circumstellar emission in Halpha. We found
that: W080 could be a new He-strong star, like W601. W301 is a possible
classical Be star, W503 is a mass-transfer eclipsing binary with an accretion
disk, and the other ones are possible Herbig Ae/Be stars. We also found that
the rotational velocities of main sequence B stars are 18% lower than those of
pre-main sequence B stars, in good agreement with theory about the evolution of
rotational velocities. Combining different indications and technics, we found
that 27% of the B-type stars are binaries. We also redetermined the age of
NGC6611 found equal to 1.2--1.8 Myears in good agreement with the most recent
determinations.


title: A prediction of string theory testable at low energies

abstract:
  Superstring theory involves a single unifying superstring current for bosons
and fermions that in the low-energy limit generalizes the Klein-Gordon (not the
Dirac) current. By adopting a relativistic-covariant probabilistic
interpretation of the current, the low-energy limit implies electron
interference patterns that, under certain conditions, differ from those
predicted by the Dirac current.


title:
Non-LTE Spectral Analysis of Extremely Hot Post-AGB Stars: Constraints
  for Evolutionary Theory

abstract:
  Spectral analysis by means of Non-LTE model-atmosphere techniques has arrived
at a high level of sophistication: fully line-blanketed model atmospheres which
consider opacities of all elements from H to Ni allow the reliable
determination of photospheric parameters of hot, compact stars. Such models
provide a crucial test of stellar evolutionary theory: recent abundance
determinations of trace elements like, e.g., F, Ne, Mg, P, S, Ar, Fe, and Ni
are suited to investigate on AGB nucleosynthesis. E.g., the strong Fe depletion
found in hydrogen-deficient post-AGB stars is a clear indication of an
efficient s-process on the AGB where Fe is transformed into Ni or even heavier
trans iron-group elements. We present results of recent spectral analyses based
on high-resolution UV observations of hot stars.


title:
Squark anti-squark pair production at the LHC: the electroweak
  contribution

abstract:
  We present the complete NLO electroweak contribution of
$\mathcal{O}(\alpha^2_s \alpha)$ to the production of diagonal
squark--anti-squark pairs in proton--proton collisions. Compared to the
lowest-order $\mathcal{O}(\alpha_s\alpha + \alpha^2)$ electroweak terms, the
NLO contributions are also significant. We discuss the LO and NLO electroweak
effects in cross sections and distributions at the LHC for the production of
squarks different from top squarks, in various supersymmetric benchmark
scenarios.


title: Optical to Near-IR Spectrum of a Massive Evolved Galaxy at z = 1.26

abstract:
  We present the optical to near-infrared (IR) spectrum of the galaxy TSPS
J1329-0957, a red and bright member of the class of extremely red objects
(EROs) at z = 1.26. This galaxy was found in the course of the Tokyo-Stromlo
Photometry Survey (TSPS) which we are conducting in the southern sky. The
spectroscopic observations were carried out with the Gemini Multi-Object
Spectrograph (GMOS) and the Gemini Near Infra-Red Spectrograph (GNIRS) mounted
on the Gemini-South telescope. The wide wavelength coverage of 0.6 - 2.3 um
provides useful clues as to the nature of EROs while most published spectra are
limited to a narrower spectral range which is dictated by the need for
efficient redshift determination in a large survey. We compare our spectrum
with several optical composite spectra obtained in recent large surveys, and
with stellar population synthesis models. The effectiveness of using near-IR
broad-band data, instead of the spectral data, in deriving the galaxy
properties are also investigated. We find that TSPS J1329-0957 formed when the
universe was 2 - 3 Gyr old, and subsequently evolved passively to become one of
the most massive galaxies found in the z = 1 - 2 universe. Its early type and
estimated stellar mass of M* = 10^{11.5} Msun clearly point to this galaxy
being a direct ancestor of the brightest elliptical and spheroidal galaxies in
the local universe.


title: An extension problem for convex functions

abstract:
  We give a statement on extension with estimates of convex functions defined
on a linear subspace, inspired by similar extension results concerning metrics
on positive line bundles


title: On invariants for Legendrian knots

abstract:
  Suppose that L is a null--homologous Legendrian knot in a contact
3--manifold. We determine the connection between the sutured invariant of the
complement of L and the Legendrian invariant defined by Lisca, Ozsvath,
Stipsicz and Szabo. In particular, we derive a vanishing theorem for the
Legendrian invariant in the presence of Giroux torsion in the complement of the
knot, and reprove several known properties of the Legendrian invariant from
this perspective.


title:
Third-Order Density Perturbation and One-Loop Power Spectrum in
  Dark-Energy-Dominated Universe

abstract:
  We investigate the third-order density perturbation and the one-loop
correction to the linear power spectrum in the dark-energy cosmological model.
Our main interest is to understand the dark-energy effect on baryon acoustic
oscillations in a quasi-nonlinear regime ($k \approx 0.1h$/Mpc). Analytical
solutions and simple fitting formulae are presented for the dark-energy model
with the general time-varying equation of state $w(a)$. It turns out that the
power spectrum coincides with the approximate result based on the EdS (Einstein
de-Sitter) model within 1% for $k<0.4h/$Mpc at $z=0$ in the WMAP (Wilkinson
Microwave Anisotropy Probe) 5yr best-fitting cosmological model, which suggests
that the cosmological dependence is very small.


title: On Mean Distance and Girth

abstract:
  We bound the mean distance in a connected graph which is not a tree in
function of its order $n$ and its girth $g$. On one hand, we show that mean
distance is at most $\frac{n+1}{3}-\frac{g(g^2-4)}{12n(n-1)}$ if $g$ is even
and at most $\frac{n+1}{3}-\frac{g(g^2-1)}{12n(n-1)}$ if $g$ is odd. On the
other hand, we prove that mean distance is at least $\frac{ng}{4(n-1)}$ unless
$G$ is an odd cycle.


title: Dynamic Network of Concepts from Web-Publications

abstract:
  The network, the nodes of which are concepts (people's names, companies'
names, etc.), extracted from web-publications, is considered. A working
algorithm of extracting such concepts is presented. Edges of the network under
consideration refer to the reference frequency which depends on the fact how
many times the concepts, which correspond to the nodes, are mentioned in the
same documents. Web-documents being published within a period of time together
form an information flow, which defines the dynamics of the network studied.
The phenomenon of its structure stability, when the number of web-publications,
constituting its formation bases, increases, is discussed


title: On the extendability of elliptic surfaces of rank two and higher

abstract:
  We study threefolds X in a projective space having as hyperplane section a
smooth surface with an elliptic fibration. We first give a general theorem
about the possible embeddings of such surfaces with Picard number two. More
precise results are then proved for Weierstrass fibrations, both of rank two
and higher. In particular we prove that a Weierstrass fibration of rank two
that is not a K3 surface is not hyperplane section of a locally complete
intersection threefold and we give some conditions, for many embeddings of
Weierstrass fibrations of any rank, under which every such threefold must be a
cone.


title:
Current noise of a superconducting single electron transistor coupled to
  a resonator

abstract:
  We analyze the current and zero-frequency current noise properties of a
superconducting single electron resonator (SSET) coupled to a resonator,
focusing on the regime where the SSET is operated in the vicinity of the
Josephson quasiparticle resonance. We consider a range of coupling strengths
and resonator frequencies to reflect the fact that in practice the system can
be tuned to quite a high degree with the resonator formed either by a
nanomechanical oscillator or a superconducting stripline fabricated in close
proximity to the SSET. For very weak couplings the SSET acts on the resonator
like an effective thermal bath. In this regime the current characteristics of
the SSET are only weakly modified by the resonator. Using a mean field
approach, we show that the current noise is nevertheless very sensitive to the
correlations between the resonator and the SSET charge. For stronger couplings,
the SSET can drive the resonator into limit cycle states where self-sustained
oscillation occurs and we find that regions of well-defined bistability exist.
Dynamical transitions into and out of the limit cycle state are marked by
strong fluctuations in the resonator energy, but these fluctuations are
suppressed within the limit cycle state. We find that the current noise of the
SSET is strongly influenced by the fluctuations in the resonator energy and
hence should provide a useful indicator of the resonator's dynamics.


title: The Alexander-Orbach conjecture holds in high dimensions

abstract:
  We examine the incipient infinite cluster (IIC) of critical percolation in
regimes where mean-field behavior has been established, namely when the
dimension d is large enough or when d>6 and the lattice is sufficiently spread
out. We find that random walk on the IIC exhibits anomalous diffusion with the
spectral dimension d_s=4/3, that is, p_t(x,x)= t^{-2/3+o(1)}. This establishes
a conjecture of Alexander and Orbach. En route we calculate the one-arm
exponent with respect to the intrinsic distance.


title:
Upper critical field, penetration depth, and depinning frequency of the
  novel high-temperature superconductor LaFeAsO$_{0.9}$F$_{0.1}$ studied by
  microwave surface impedance

abstract:
  Temperature and magnetic field dependent measurements of the microwave
surface impedance of superconducting LaFeAsO$_{0.9}$F$_{0.1}$ (\Tc $\approx$
26K) reveal a very large upper critical field ($B_{\rm c2} \approx 56$T) and a
large value of the depinning frequency ($f_{0}\approx 6$GHz); together with an
upper limit for the effective London penetration depth, $\lambda_{\rm eff} \le
200 \rm nm$, our results indicate a strong similarity between this system and
the high-$T_{\rm c}$ superconducting cuprates.


title: Light Propagation in Linear Arrays of Spherical Particles

abstract:
  A propagation of dipolar radiation in a finite length linear chain of
identical dielectric spheres is investigated using the multisphere Mie
scattering formalism (MSMS). A frequency pass band is shown to be formed near
every Mie resonances inherent in the spheres. The manifestation of the pass
band depends on the polarization of the travelling radiation. To prove this
effect, a point dipole placed by the end of the chain is used as an external
source of radiation. It is found that, if this dipole is directed parallel to
the to the chain axis, the frequency pass bands exist if the refractive index
of dielectric spheres is sufficiently large. For the dipole normal to the chain
axis, the pass band can always be formed if the chain is sufficiently long.
Such a distinction is due to different behavior of the far-field dipolar
interaction between the spheres induced by the external source. The edges of
the pass bands are defined by the guiding wave criterion based on the
light-cone constraint. The criterion of creation of the pass bands correlate
with condition of formation of high quality factor modes in these systems found
in our previous papers. A comparison with the results available for infinite
chains is made. In particular, we clarify the nature of braking down the band
structure for small enough wavevectors.


title:
Radial metallicity profiles for a large sample of galaxy clusters
  observed with XMM-Newton

abstract:
  Aims. We measured radial metallicity profiles for a sample of ~50 hot,
intermediate redshift galaxy clusters, selected from the XMM-Newton archive.
  Methods. As in our previous paper, we used background modeling rather than
background subtraction, and the Cash statistic rather than the chi square. This
method requires a careful characterization of all background components. We
also performed montecarlo simulations to assess systematic effects.
  Results. The mean metallicity profile shows a peak in the center, and gently
declines out to 0.2 R_{180}. Beyond 0.2 R_{180} the metallicity is roughly 0.2
solar and, at variance with recently published expectations based on
simulations, consistent with being flat. We find no evidence of profile
evolution from z=0.1 to z=0.3. When comparing our mean profile to those
obtained by recent works with BeppoSAX and Chandra, we find remarkable
agreement over the entire radial range.


title: Fast Wavelet-Based Visual Classification

abstract:
  We investigate a biologically motivated approach to fast visual
classification, directly inspired by the recent work of Serre et al.
Specifically, trading-off biological accuracy for computational efficiency, we
explore using wavelet and grouplet-like transforms to parallel the tuning of
visual cortex V1 and V2 cells, alternated with max operations to achieve scale
and translation invariance. A feature selection procedure is applied during
learning to accelerate recognition. We introduce a simple attention-like
feedback mechanism, significantly improving recognition and robustness in
multiple-object scenes. In experiments, the proposed algorithm achieves or
exceeds state-of-the-art success rate on object recognition, texture and
satellite image classification, language identification and sound
classification.


title:
One-loop gg->bb(bar) effects in the main irreducible background to
  exclusive H->bb(bar) production at the LHC

abstract:
  We calculate the amplitude of gg->bb(bar) production for the colour singlet,
J_z=0 di-gluon state at O(\alpha_S^2) order. We consider the cancellation, and
a realistic cutoff, of the infrared divergent terms. We show that the one-loop
radiative QCD contributions effectively reduce the Born level result for the
central exclusive bb(bar) cross section at the LHC. This process is essentially
the only irreducible QCD background to the exclusive H->bb(bar) signal.


title:
Non-Markovian band-edge effect and entanglement generation of quantum
  dot excitons coupled to nanowire surface plasmons

abstract:
  The radiative decay of quantum dot (QD) excitons into surface plasmons in a
cylindrical nanowire is investigated theoretically. Maxwell's equations with
appropriate boundary conditions are solved numerically to obtain the dispersion
relations of surface plasmons. The radiative decay rate of QD excitons is found
to be greatly enhanced at certain values of the exciton bandgap. Analogous to
the decay of a two-level atom in the photonic crystal, we first point out that
such an enhanced phenomenon allows one to examine the non-Markovian dynamics of
the QD exciton. Besides, due to the one dimensional propagating feature of
nanowire surface plasmons, remote entangled states can be generated via
super-radiance and may be useful in future quantum information processing.


title: The Neutrino Flux prediction at MiniBooNE

abstract:
  The Booster Neutrino Experiment (MiniBooNE) searches for numu-to-nue
oscillations using the O(1 GeV) neutrino beam produced by the Booster
synchrotron at the Fermi National Accelerator Laboratory (FNAL). The Booster
delivers protons with 8 GeV kinetic energy (8.89 GeV/c momentum) to a beryllium
target, producing neutrinos from the decay of secondary particles in the beam
line. We describe the Monte Carlo simulation methods used to estimate the flux
of neutrinos from the beamline incident on the MiniBooNE detector for both
polarities of the focussing horn. The simulation uses the Geant4 framework for
propagating particles, accounting for electromagnetic processes and hadronic
interactions in the beamline materials, as well as the decay of particles. The
absolute double differential cross sections of pion and kaon production in the
simulation have been tuned to match external measurements, as have the hadronic
cross sections for nucleons and pions. The statistical precision of the flux
predictions is enhanced through reweighting and resampling techniques.
Systematic errors in the flux estimation have been determined by varying
parameters within their uncertainties, accounting for correlations where
appropriate.


title:
Influence of the Nd3+ Moments on the Magnetic Behaviour of the
  Oxypnictides superconductors NdFeAsO1-xFx

abstract:
  This paper has been withdrawn by the authors as the available data were not
sufficient to support the conclusions


abstract:
  As the title ``Generalized regularity and solution concepts for differential
equations'' suggests, the main topic of my thesis is the investigation of
generalized solution concepts for differential equations, in particular first
order hyperbolic partial differential equations with real-valued, non-smooth
coefficients and their characteristic system of ordinary differential
equations.
  In Colombeau theory there have been developed existence results that yield
solutions for ordinary and partial differential equations beyond the scope of
classical approaches. Nevertheless this comes at the price of sacrificing
regularity (in general a Colombeau solution may even lack a distributional
shadow). It is prevailing in the Colombeau setting that the question of mere
existence of solutions is much easier to answer than to determine their
regularity properties (i.e. if a distributional shadow exists and how regular
it is). In order order to address these regularity question and encouraged by
the fact that the solution of a (homogeneous) first order partial differential
equation can be written as a pullback of the initial condition by the
characteristic backward flow, a main topic of my thesis deals with the
microlocal analysis of pullbacks of c-bounded Colombeau generalized functions.
  Another topic is the comparsion of Colombeau techniques for solving ordinary
and partial differential equations to other generalized solution concepts,
which has led to a joint article with G\"unther H\"ormann. A useful tool for
this purpose is the concept of a generalized graph, which has been developed in
the thesis.


title: Discontinuities in Scalar Perturbations of Topological Black Holes

abstract:
  We study the perturbative behaviour of topological black holes. We calculate
both analytically and numerically the quasi-normal modes of scalar
perturbations. In the case of small black holes we find discontinuities of the
quasi-normal modes spectrum at the critical temperature and we argue that this
is evidence of a second-order phase transition.


title: A counter example on nontangential convergence for oscillatory integrals

abstract:
  Consider the solution of the time-dependent Schr{\"o}dinger equation with
initial data $f$. It is shown in \cite{artikel} that there exists $f$ in the
Sobolev space $H^s(\RR), s=n/2$ such that tangential convergence can not be
widened to convergence regions. In this paper we show that the corresponding
result holds when $-\Delta_x$ is replaced by an operator $\phi(D)$, with
special conditions on $\phi$.


title: Quark-Model Identification of Baryon Ground and Resonant States

abstract:
  We present a new classification scheme of baryon ground states and resonances
into SU(3) flavor multiplets. The scheme is worked out along a covariant
formalism with relativistic constituent quark models and it relies on detailed
investigations of the baryon spectra, the spin-flavor structure of the baryon
eigenstates, the behaviour of their probability density distributions as well
as covariant predictions for mesonic decay widths. The results are found to be
quite independent of the specific types of relativistic constituent quark
models employed. It turns out that a consistent classification requires to
include also resonances that are presently reported from experiment with only
two-star status.


title:
Evidence for coupling between collective state and phonons in
  two-dimensional charge-density-wave systems

abstract:
  We report on a Raman scattering investigation of the charge-density-wave
(CDW), quasi two-dimensional rare-earth tri-tellurides $R$Te$_3$ ($R$= La, Ce,
Pr, Nd, Sm, Gd and Dy) at ambient pressure, and of LaTe$_3$ and CeTe$_3$ under
externally applied pressure. The observed phonon peaks can be ascribed to the
Raman active modes for both the undistorted as well as the distorted lattice in
the CDW state by means of a first principles calculation. The latter also
predicts the Kohn anomaly in the phonon dispersion, driving the CDW transition.
The integrated intensity of the two most prominent modes scales as a
characteristic power of the CDW-gap amplitude upon compressing the lattice,
which provides clear evidence for the tight coupling between the CDW condensate
and the vibrational modes.


title:
Competition of multiband superconducting and magnetic order in ErNi2B2C
  observed by Andreev reflection

abstract:
  Point contacts (PC) Andreev reflection dV/dI spectra for the
antiferromagnetic (T_N =6K) superconductor (Tc=11K) ErNi2B2C have been measured
for the two main crystallographic directions. Observed retention of the Andreev
reflection minima in dV/dI up to Tc directly points to unusual superconducting
order parameter (OP) vanishing at Tc. Temperature dependence of OP was obtained
from dV/dI using recent theory of Andreev reflection including pair-breaking
effect. For the first time existence of a two superconducting OPs in ErNi2B2C
is shown. A distinct decrease of both OPs as temperature is lowered below T_N
is observed.


title: Sharp bounds for symmetric and asymmetric Diophantine approximation

abstract:
  In 2004, J.C. Tong found bounds for the approximation quality of a regular
continued fraction convergent of a rational number, expressed in bounds for
both the previous and next approximation. We sharpen his results with a
geometric method and give both sharp upper and lower bounds. We also calculate
the asymptotic frequency that these bounds occur.


title: Creep motion of a granular pile induced by thermal cycling

abstract:
  We report a time-resolved study of the dynamics associated with the slow
compaction of a granular column submitted to thermal cycles. The column height
displays a complex behavior: for a large amplitude of the temperature cycles,
the granular column settles continuously, experiencing a small settling at each
cycle; By contrast, for small-enough amplitude, the column exhibits a
discontinuous and intermittent activity: successive collapses are separated by
quiescent periods whose duration is exponentially distributed. We then discuss
potential mechanisms which would account for both the compaction and the
transition at finite amplitude.


title:
Transport properties and superconductivity in $Ba_{1-x}M_xFe_2As_2$
  (M=La and K) with double FeAs layers

abstract:
  We synthesized the samples $Ba_{1-x}M_xFe_2As_2$ (M=La and K) with
$ThCr_2Si_2$-type structure. These samples were systematically characterized by
resistivity, thermoelectic power (TEP) and Hall coefficient ($R_H$).
$BaFe_2As_2$ shows an anomaly in resistivity at about 140 K. Substitution of La
for Ba leads to a shift of the anomaly to low temperature, but no
superconducting transition is observed. Potassium doping leads to suppression
of the anomaly in resistivity and induces superconductivity at 38 K as reported
by Rotter et al.\cite{rotter}. The Hall coefficient and TEP measurements
indicate that the TEP is negative for $BaFe_2As_2$ and La-doped $BaFe_2As_2$,
indicating n-type carrier; while potassium doping leads to change of the sign
in $R_H$ and TEP. It definitely indicates p-type carrier in superconducting
$Ba_{1-x}K_xFe_2As_2$ with double FeAs layers, being in contrast to the case of
$LnO_{1-x}F_xFeAs$ with single FeAs layer. A similar superconductivity is also
observed in the sample with nominal composition $Ba_{1-x}K_xOFe_2As_2$.


title: The Early Expansion of Cluster Cores

abstract:
  The observed properties of young star clusters, such as the core radius and
luminosity profile, change rapidly during the early evolution of the clusters.
Here we present observations of 6 young clusters in M51 where we derive their
sizes using HST imaging and ages using deep Gemini-North spectroscopy. We find
evidence for a rapid expansion of the cluster cores during the first 20 Myr of
their evolution. We confirm this trend by including data from the literature of
both Galactic and extra-galactic embedded and young clusters, and possible
mechanisms (rapid gas removal, stellar evolutionary mass-loss, and internal
dynamical heating) are discussed. We explore the implications of this result,
focussing on the fact that clusters were more concentrated in the past,
implying that their stellar densities were much higher and relaxation times
correspondingly shorter. Thus, when estimating if a particular cluster is
dynamically relaxed, (i.e. when determining if a cluster's mass segregation is
due to primordial or dynamical processes), the current relaxation time is only
an upper-limit, with the relaxation time likely being significantly shorter in
the past.


title:
Generalized Thomas hyperplane sections and relations between vanishing
  cycles

abstract:
  As is remarked by B. Totaro, R. Thomas essentially proved that the Hodge
conjecture is inductively equivalent to the existence of a hyperplane section,
called a generalized Thomas hyperplane section, such that the restriction to it
of a given primitive Hodge class does not vanish. We study the relations
between the vanishing cycles in the cohomology of a general fiber, and show
that each relation between the vanishing cycles of type (0,0) with unipotent
monodromy around a singular hyperplane section defines a primitive Hodge class
such that this singular hyperplane section is a generalized Thomas hyperplane
section if and only if the pairing between a given primitive Hodge class and
some of the constructed primitive Hodge classes does not vanish. This is a
generalization of a construction by P. Griffiths.


title: RESIK observations of He-like Ar X-ray line emission in solar flares

abstract:
  The Ar XVII X-ray line group principally due to transitions 1s2 - 1s2l (l=s,
p) near 4 Anstroms was observed in numerous flares by the RESIK bent crystal
spectrometer aboard CORONAS-F between 2001 and 2003. The three line features
include the Ar XVII w (resonance line), a blend of x and y (intercombination
lines), and z (forbidden line), all of which are blended with Ar XVI
dielectronic satellites. The ratio G, equal to [I(x+y) + I(z)]/I(w), varies
with electron temperature Te mostly because of unresolved dielectronic
satellites. With temperatures estimated from GOES X-ray emission, the observed
G ratios agree fairly well with those calculated from CHIANTI and other data.
With a two-component emission measure, better agreement is achieved. Some S XV
and S XVI lines blend with the Ar lines, the effect of which occurs at
temperatures greater than 8MK, allowing the S/Ar abundance ratio to be
determined. This is found to agree with coronal values. A nonthermal
contribution is indicated for some spectra in the repeating-pulse flare of 2003
February 6.


title:
Features of Propagation of Light in the Linear Array of Dielectric
  Spheres

abstract:
  A finite length linear chain of dielectric loss-less identical spheres is
considered. A propagation of dipole radiation in the chain of particles induced
by the point dipole source placed near one end of the chain is investigated. It
is found that at sufficiently large refractive index there exist frequency pass
bands around every low frequency Mie resonance. In particular, if the dipole
oscillates across the chain axis, one can reveal a longitudinal mode frequency
pass band if refractive index of the spheres exceeds 1.9. Then, if the dipole
oscillates transversely to the chain axis, the transverse frequencies pass
bands show up depending on the chain length. In this case, the pass band is
formed if the length chain is large enough. Three dielectric materials ZnO,
rutile and GaAs are considered. It is found that the top of the frequency pass
band corresponds to the top of the Brillouin band edge in the quasi-momentum
space. On the order hand, the bottom of the frequency pass band corresponds to
the guiding wave criterion. This explains the remarkable feature of the band
picture established for infinite chain: the band structure breaks down as the
wavevector becomes small enough. The multisphere Mie scattering formalism is
used to calculate how the amplitude of the radiation changes along the chain.


title: Stellar Disruption and the Quasar Radio Dichotomy

abstract:
  The origin of the dichotomy of radio loudness among quasars can be explained
using recent findings that the mass of the central supermassive black hole
(SMBH) in extended radio-loud quasars is systematically a few times that of
their counterparts in radio-quiet quasars. This sensitive dependence of radio
jet ejection upon SMBH mass probably arises from the blockage of jets by the
presence of substantial quantities of gas tidally stripped from stars by the
central BH. This disruptive gas, however, will only be available around BHs
with masses less than $M_c ~\gtrsim ~10^8\Msun$, for which the tidal disruption
radius lies outside the SMBH's event horizon. Consequently, we find that AGN
with $M_{BH} > M_c$ can successfully launch jets with a wide range of powers,
thus producing radio-loud quasars. The great majority of jets launched by less
massive BHs, however, will be truncated in the vicinity of the SMBH due to mass
loading from this stellar debris. This scenario also can naturally explain the
remarkable dearth of extended radio structures in quasars showing broad
absorption line spectra.


title: Aspects of Purely Transmitting Defects in Integrable Field Theories

abstract:
  Some classical and quantum aspects of integrable defects are reviewed with
particular emphasis on the behaviour of solitons in the sine-Gordon model.


title: Quantum Painlev\'e Equations: from Continuous to Discrete

abstract:
  We examine quantum extensions of the continuous Painlev\'e equations,
expressed as systems of first-order differential equations for non-commuting
objects. We focus on the Painlev\'e equations II, IV and V. From their
auto-B\"acklund transformations we derive the contiguity relations which we
interpret as the quantum analogues of the discrete Painlev\'e equations.


title: Hadron and Photon Production in the Forward Region at RHIC and LHC

abstract:
  In this paper we investigate the hadron and photon production at forward
rapidities in $pp$ and $pA$ collisions considering two phenomenological models
based on the Color Glass Condensate formalism. The predictions of these models
for the hadron spectra are compared with the dAu and pp RHIC data and the
nuclear modification factor $R_{hA}$ is estimated. Our results demonstrate that
the analysis of the transverse momentum dependence of this factor allows to
discriminate between the phenomenological models. Furthermore, we predict
$R_{hA}$ for photon production at forward rapidities at RHIC and LHC energies
and study the $p_T$ dependence of the photon to pion production ratio.


title: Carbon Nanotube Electron Windmills: A Novel Design for Nanomotors

abstract:
  We propose a new drive mechanism for carbon nanotube (CNT) motors, based upon
the torque generated by a flux of electrons passing through a chiral nanotube.
The structure of interest comprises a double-walled CNT, formed from, for
example, an achiral outer tube encompassing a chiral inner tube. Through a
detailed analysis of electrons passing through such a "windmill", we find that
the current due to a potential difference applied to the outer CNT generates
sufficient torque to overcome the static and dynamic frictional forces that
exists between the inner and outer walls, thereby causing the inner tube to
rotate.


title:
Effect of correlated disorder on the temperature of unconventional
  Cooper pairing (3He in aerogel)

abstract:
  Using liquid 3He in aerogel as an example, it is shown that correlations in
positions of impurities affect the temperature $T_c$ of transition of Fermi
liquid in an unconventional superfluid or superconductive state. The effect is
significant if the correlation length for impurities is greater than the
coherence length in the superfluid or superconductive state $\xi_0$. For 3He in
aerogel the suppression of $T_c$ is expressed in terms of the structure factor
of aerogel. With the account of the fractal structure of aerogel a simple
expression is obtained for the decrease of $T_c$ from its clean value. This
expression is in a satisfactory agreement with experimental data.


title: Non-linear effects in electrolytes at large applied voltage

abstract:
  The steady state of ions diffusion in polymer electrolytes at arbitrary
applied voltage is analyzed in the framework of the Nernst-Planck-Poisson
equation (NPP). The exact solution of the set of equations is found without the
assumption of low ions concentration. The solution is independent of the
kinetic properties of the system. At constant voltage there is a master curve
for concentration in terms of the initial concentration. Enhancing the voltage
causes an increase of the ion concentration gradient and consequently the
applicability of the NPP is violated for high voltages. The analytical finding
is estimated by using experimental data from recent measurements (P. Kohn et al
Phys. Rev. Left. 99, 086104 (2007)). As the result we find an upper bound for
the validity of the NPP. Above this voltage higher order gradient terms become
relevant.


title: Status report of the Tokyo axion helioscope experiment

abstract:
  We have searched for solar axions with a detector which consists of a 4T x
2.3m superconducting magnet, PIN-photodiode X-ray detectors, and an altazimuth
mount to track the sun. The conversion region is filled with cold helium gas
which modifies the axion mass at which coherent conversion occurs. In the past
measurements, axion mass from 0 to 0.27eV have been scanned. Since no positive
evidence was seen, an upper limit to the axion-photon coupling constant was set
to be g < 6-10E-10/GeV (95%CL) depending on the axion masses. We are now
actively preparing for a new stage of the experiment aiming at one to a few eV
solar axions. In this mass region, our detector might be able to check
parameter regions which are preferable to the axion models.


title: Vector-like quarks in a composite Higgs model

abstract:
  Vector-like quarks are a common feature of "composite" Higgs models, where
they intervene in cutting off the top-loop contribution to the Higgs boson mass
and may, at the same time, affect the Electroweak Precision Tests (EWPT). A
model based on SO(5)/SO(4) is here analyzed. In a specific non minimal version,
vector-like quarks of mass as low as 300-500 GeV are allowed in a thin region
of its parameter space. Other models fail to be consistent with the EWPT.


title:
Analysis of Metric Distances and Volumes of Hippocampi Indicates
  Different Morphometric Changes over Time in Dementia of Alzheimer Type and
  Nondemented Subjects

abstract:
  In this article, we analyze the morphometry of hippocampus in subjects with
very mild dementia of Alzheimer's type (DAT) and nondemented controls and how
it changes over a two-year period. Morphometric differences with respect to a
template hippocampus were measured by the metric distance obtained from the
Large Deformation Diffeomorphic Metric Mapping (LDDMM) algorithm which was
previously used to calculate dense one-to-one correspondence vector fields
between the shapes. LDDMM assigns metric distances on the space of anatomical
images thereby allowing for the direct comparison and quantization of
morphometric changes. We use various statistical methods to compare the metric
distances in a cross-sectional and longitudinal manner. At baseline, the metric
distances for demented subjects are found not to be significantly different
from those for nondemented subjects. At follow-up, the metric distances for
demented subjects were significantly larger compared to nondemented subjects.
The metric distances for demented subjects increased significantly from
baseline to follow-up but not for nondemented subjects. We also use the metric
distances in logistic regression for diagnostic discrimination of subjects. We
compare metric distances with the volumes and obtain similar results. In
classification, the model that uses volume, metric distance, and volume loss
over time together performs better in detecting DAT. Thus, metric distances
with respect to a template computed via LDDMM can be a powerful tool in
detecting differences in shape in cross-sectional as well as longitudinal
studies.


title: Embedding quantum and random optics in a larger field theory

abstract:
  Introducing creation and annihilation operators for negative frequency
components extends the algebra of smeared local observables of quantum optics
to include an associated classical random field optics.


title: Tunable Graphene Single Electron Transistor

abstract:
  We report electronic transport experiments on a graphene single electron
transistor. The device consists of a graphene island connected to source and
drain electrodes via two narrow graphene constrictions. It is electrostatically
tunable by three lateral graphene gates and an additional back gate. The
tunneling coupling is a strongly nonmonotonic function of gate voltage
indicating the presence of localized states in the barriers. We investigate
energy scales for the tunneling gap, the resonances in the constrictions and
for the Coulomb blockade resonances. From Coulomb diamond measurements in
different device configurations (i.e. barrier configurations) we extract a
charging energy of 3.4 meV and estimate a characteristic energy scale for the
constriction resonances of 10 meV.


title: On the opposite of the category of rings

abstract:
  We define a faithful contravariant functor NCSpec from the category of rings
to the category of ringed spaces, and show that if R is a commutative ring then
NCSpec(R) may be viewed as a completion of Spec(R) in an appropriate sense. We
then explain how the spaces NCSpec(R) may be glued, and study quasicoherent
sheaves on them. As an example, we compute the category of quasicoherent
sheaves on a space constructed from a skew-polynomial ring R by an analogue of
the Proj construction.


title: N=2 Einstein-Yang-Mills's BPS solutions

abstract:
  We find the general form of all the supersymmetric configurations and
solutions of N=2,d=4 Einstein-Yang-Mills theories. In the timelike case, which
we study in great detail, giving many examples, the solutions to the full
supergravity equations can be constructed from known flat spacetime solutions
of the Bogomol'nyi equations. This allows the regular supersymmetric embedding
in supergravity of regular monopole solutions ('t Hooft-Poyakov's, Weinberg's,
Wilkinson and Bais's) but also embeddings of irregular solutions to the
Bogomol'nyi equations which turn out to be regular black holes with different
forms of non-Abelian hair once the non-triviality of the spacetime metric is
taken into account. The attractor mechanism is realized in a gauge-covariant
way. In the null case we determine the general equations that supersymmetric
configurations and solutions must satisfy but we do not find relevant new
supersymmetric solutions.


title: WASP-14b: 7.3 Mj transiting planet in an eccentric orbit

abstract:
  We report the discovery of a 7.3 Mjup exoplanet WASP-14b, one of the most
massive transiting exoplanets observed to date. The planet orbits the
tenth-magnitude F5V star USNO-B1 11118-0262485 with a period of 2.243752 days
and orbital eccentricity e = 0.09. A simultaneous fit of the transit light
curve and radial velocity measurements yields a planetary mass of 7.3+/-0.5
Mjup and a radius of 1.28+/-0.08 Rjup. This leads to a mean density of about
4.6 g/cm^3 making it densest transiting exoplanets yet found at an orbital
period less than 3 days. We estimate this system to be at a distance of
160+/-20 pc. Spectral analysis of the host star reveals a temperature of
6475+/-100 K, log g = 4.07 cm/s^2 and vsin i = 4.9+/-1.0 km/s, and also a high
lithium abundance, log N(Li} = 2.84+/-0.05. The stellar density, effective
temperature and rotation rate suggest an age for the system of about 0.5-1.0
Gyr.


title: Exciton BCS or BEC state in a semiconductor bilayer system?

abstract:
  We calculate the off-diagonal long range order (ODLRO) terms of the
exciton--exciton correlation function of a semiconductor bilayer system with
Coulomb interaction and a transverse magnetic field. We show that the formation
of a BEC state is very sensitive to the width of the interaction in momentum
space. This dependence is analytically derived and represents the key physical
ingredient for the formation (or not) of an exciton condensate state.


title:
On the number of matrices and a random matrix with prescribed row and
  column sums and 0-1 entries

abstract:
  We consider the set Sigma(R,C) of all mxn matrices having 0-1 entries and
prescribed row sums R=(r_1, ..., r_m) and column sums C=(c_1, ..., c_n). We
prove an asymptotic estimate for the cardinality |Sigma(R, C)| via the solution
to a convex optimization problem. We show that if Sigma(R, C) is sufficiently
large, then a random matrix D in Sigma(R, C) sampled from the uniform
probability measure in Sigma(R,C) with high probability is close to a
particular matrix Z=Z(R,C) that maximizes the sum of entropies of entries among
all matrices with row sums R, column sums C and entries between 0 and 1.
Similar results are obtained for 0-1 matrices with prescribed row and column
sums and assigned zeros in some positions.


title:
Relaxation Time and Relaxation Function of Quark-Gluon Plasma with
  Lattice QCD

abstract:
  We propose a method which enables a QCD-based calculation of a relaxation
time for a dissipative current in the causal and dissipative hydrodynamic
equation derived by Israel and Stewart. We point out that the Israel-Stewart
equation is not unique as a causal and dissipative hydrodynamic equation, and
the form of the causal and dissipative hydrodynamic equation is determined by
the shape of a spectral function reflecting the properties of elementary
excitations in the system we consider. Our method utilizes a relaxation
function, which can be calculated from QCD using the linear response theory. We
show that the relaxation function can be derived from a spectral function for a
microscopic representation of the dissipative current. We also show that the
Israel-Stewart equation is acceptable only as long as the calculated relaxation
function is approximated well by a exponentially damping function, and the
relaxation time can be obtained as its damping time constant. Taking a
baryon-number dissipative current of a plasma consisting of charm quarks and
gluons as a simple example, we present the first calculation of the relaxation
function with use of the spectral function derived employing the quenched
lattice QCD together with the maximum entropy method. The calculated relaxation
function shows a strongly-oscillation damping behaviour due to the charmed
vector hadron $J/\Psi$ surviving above the deconfinement phase transition
temperature in QCD. This result suggests that the applicability of the
Israel-Stewart equation to the baryon-number dissipative current of the charm
quark-gluon plasma is quite doubtful. We present an idea for the improvement of
the Israel-Stewart equation by deriving the hydrodynamic equation consistent
with the strongly-oscillation damping relaxation function.


title: WASP-10b: a 3M_J, gas-giant planet transiting a late-type K star

abstract:
  We report the discovery of WASP-10b, a new transiting extrasolar planet (ESP)
discovered by the WASP Consortium and confirmed using NOT FIES and SOPHIE
radial velocity data. A 3.09 day period, 29 mmag transit depth, and 2.36 hour
duration are derived for WASP-10b using WASP and high precision photometric
observations. Simultaneous fitting to the photometric and radial velocity data
using a Markov-chain Monte Carlo procedure leads to a planet radius of 1.28R_J,
a mass of 2.96M_J and eccentricity of ~0.06. WASP-10b is one of the more
massive transiting ESPs, and we compare its characteristics to the current
sample of transiting ESP, where there is currently little information for
masses greater than ~2M_J and non-zero eccentricities. WASP-10's host star, GSC
2752-00114 (USNO-B1.0 1214-0586164) is among the fainter stars in the WASP
sample, with V=12.7 and a spectral type of K5. This result shows promise for
future late-type dwarf star surveys.


title:
Matching the frequency spectrum of PMS stars by means of standard and
  rotating models

abstract:
  We applied the ATON code to the computation of detailed grids of standard
(non--rotating) and rotating Pre--Main Sequence (PMS) models and computed their
adiabatic oscillation spectra,with the aim of exploring the seismic properties
of young stars. We adopt a method similar to the matching mode method by
Guenther and Brown making use, when necessary, also of our rotating
evolutionary code to compute the models for PMS stars. The method is described
by a preliminary application to the frequency spectrum of two PMS stars (85 and
278) in the young open cluster NGC 6530. For the Star 85 we confirm, with
self--consistent rotating models, previous interpretation of the data,
attributing three close frequencies to the mode n=4, l=1 and m=0,+1,--1. For
the Star 278 we find a different fit for the frequencies, corresponding to a
model within the original error box of the star, and dispute the possibility
thatthis star has an effective temperature much cooler that the red boundary of
the radial instability strip.


title: DIS on a Large Nucleus in AdS/CFT

abstract:
  We calculate the total cross section for deep inelastic scattering (DIS) on a
nucleus at high energy for a strongly coupled N=4 super Yang-Mills theory using
AdS/CFT correspondence. In analogy to the small coupling case we argue that at
high energy the total DIS cross section is related to the expectation value of
the Wilson loop formed by the quark-antiquark dipole. We model the nucleus by a
metric of a shock wave in AdS_5. We then calculate the expectation value of the
Wilson loop by finding the extrema of the Nambu-Goto action for an open string
attached to the quark and antiquark lines of the loop in the background of an
AdS_5 shock wave. We find three extrema of the Nambu-Goto action: the string
coordinates at the extrema are complex-valued and are given by three different
branches of the solution of a cubic equation. The physically meaningful
solutions for the total DIS cross section are given either by the only branch
with a purely imaginary string coordinate in the bulk or by a superposition of
the two other branches. For both solutions we obtain the forward scattering
amplitude N for the quark dipole-nucleus scattering. We study the onset of
unitarity with increasing center-of-mass energy and transverse size of the
dipole: we observe that for both solutions the saturation scale, while
energy-dependent at lower energies, at very high energy becomes independent of
energy/Bjorken-x. The saturation scale depends very strongly on the atomic
number of the nucleus as Q_s ~ A^{1/3}.


title: Growth of Diamond Films from Tequila

abstract:
  Diamond thin films were growth using Tequila as precursor by Pulsed Liquid
Injection Chemical Vapor Deposition (PLI-CVD) onto both silicon (100) and
stainless steel 304 at 850 C. The diamond films were characterized by Scanning
Electron Microscopy (SEM) and Raman spectroscopy. The spherical crystallites
(100 to 400 nm) show the characteristic 1332 cm-1 Raman band of diamond.


title:
Effect of Polymerization on the Boson Peak, from the Liquid to Glassy
  Phase

abstract:
  Raman scattering measurements are used to follow the modification of the
vibrational density of states in a reactive epoxy{amine mixture during
isothermal polymerization. Combining with Brillouin light and inelastic x-ray
scattering measurements, we analyze the variations of the boson peak and of the
Debye level while the system passes from the uid to a glassy phase upon
increasing the number of covalent bonds among the constituent molecules. We
find that the shift and the intensity decrease of the boson peak are fully
explained by the modification of the elastic medium throughout the reaction.
Surprisingly, bond-induced modifications of the structure do not affect the
relative excess of states over the Debye level.


title:
Simulations and cosmological inference: A statistical model for power
  spectra means and covariances

abstract:
  We describe an approximate statistical model for the sample variance
distribution of the non-linear matter power spectrum that can be calibrated
from limited numbers of simulations. Our model retains the common assumption of
a multivariate Normal distribution for the power spectrum band powers, but
takes full account of the (parameter dependent) power spectrum covariance. The
model is calibrated using an extension of the framework in Habib et al. (2007)
to train Gaussian processes for the power spectrum mean and covariance given a
set of simulation runs over a hypercube in parameter space. We demonstrate the
performance of this machinery by estimating the parameters of a power-law model
for the power spectrum. Within this framework, our calibrated sample variance
distribution is robust to errors in the estimated covariance and shows rapid
convergence of the posterior parameter constraints with the number of training
simulations.


title: Polytopal complexes: maps, chain complexes and... necklaces

abstract:
  The notion of polytopal map between two polytopal complexes is defined.
Surprisingly, this definition is quite simple and extends naturally those of
simplicial and cubical maps. It is then possible to define an induced chain map
between the associated chain complexes. Finally, we use this new tool to give
the first combinatorial proof of the splitting necklace theorem of Alon. The
paper ends with open questions, such as the existence of Sperner's lemma for a
polytopal complex or the existence of a cubical approximation theorem.


title:
Impact of Si nanocrystals in a-SiOx<Er> in C-Band emission for
  applications in resonators structures

abstract:
  Si nanocrystals (Si-NC) in a-SiOx<Er> were created by high temperature
annealing. Si-NC samples have large emission in a broadband region, 700nm to
1000nm. Annealing temperature, annealing time, substrate type, and erbium
concentration is studied to allow emission at 1550 nm forsamples with erbium.
Emission in the C-Band region is largely reduced by the presence of Si-NC. This
reduction may be due to less efficient energy transfer processes from the
nanocrystals than from the amorphous matrix to the Er3+ ions, perhaps due to
the formation of more centro-symmetric Er3+ sites at the nanocrystal surfaces
or to very different optimal erbium concentrations between amorphous and
crystallized samples.


title: Study of Nonthermal Emission from SNR RX J1713.7-3946 with Suzaku

abstract:
  We present results obtained from a series of observations of the supernova
remnant RX J1713.7-3946 by the Suzaku satellite. The observations cover about
two-thirds of the remnant surface. We successfully detected hard X-rays up to ~
40 keV from each pointing. The hard X-ray spectra are described by power-law
functions with photon indices of ~ 3.0, which are larger than those in the
energy region below 10 keV. Connection of the spatially-integrated XIS and HXD
spectra clearly reveals a spectral cutoff in the 0.4--40 keV X-ray spectrum.
This cutoff is interpreted to correspond to the maximum acceleration energy of
electrons emitting synchrotron radiation. The wide-band coverage of Suzaku for
the first time allows us to derive the parent electron spectrum in the cutoff
region, which shows good agreement with theoretical predictions. The inferred
cutoff energy in the spatially-integrated X-ray spectrum indicates that
particle acceleration in the remnant is so efficient that it is almost at the
theoretical limit, the so-called Bohm limit. Based on the Suzaku data, we
present results of multi-wavelength studies from spectral and morphological
points of view. The spectral energy distribution favors the hadronic scenario
rather than the leptonic scenario. For the morphology studies, we compare the
surface brightness maps from the Suzaku XIS and the H.E.S.S. telescope. We
confirm the strong correlation between X-ray and TeV gamma-ray emission. In
addition to the correlation, we found that in the bright western rim regions
the X-ray emission is brighter than expected from the general X-ray to
gamma-ray correlation.


title: N-point functions in rolling tachyon background

abstract:
  We study n-point boundary correlation functions in Timelike Boundary
Liouville theory, relevant for open string multiproduction by a decaying
unstable D-brane. We give an exact result for the one-point function of the
tachyon vertex operator and show that it is consistent with a previously
proposed relation to a conserved charge in string theory. We also discuss when
the one-point amplitude vanishes. Using a straightforward perturbative
expansion, we find an explicit expression for a tachyon n-point amplitude for
all n, however the result is still a toy model. The calculation uses a new
asymptotic approximation for Toeplitz determinants, derived by relating the
system to a Dyson gas at finite temperature.

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


title: Electromagnetism and geometry

abstract:
  This work is an introduction to modern mathematical physics. We begin with
Maxwell laws and vector calculus, pass next to consider the action and the
Feynman integral in quantum mechanics, next relativity and differential
geometry to formulate the electromagnetic laws in intrinsic form. Next we see
gravitation to study the covariant derivative. We end with the electromagnetic
bundle U(1). It contains the know-how + the know-why. The text is written in
Spanish. 340 pps.


title: Big-Bang Nucleosynthesis and WIMP dark matter in modified gravity

abstract:
  In the present work the primordial Big-Bang Nucleosynthesis (BBN) and weakly
interacting massive particle (WIMP) dark matter are discussed in a certain
class of modified gravitational theories, namely $f(R) \sim R^n$ gravity. The
new gravitational model is characterized by a single parameter $n$. First we
determine the conditions under which the theoretical predictions for the
$^{4}$He abundance are in agreement with the observations. More precisely,
during BBN the physics is known and all the parameters are known. The only free
parameter to be constrained is the power $n$ related to the new gravitational
model. After that, for cold dark matter we use the value of $n$ determined from
the BBN considerations and determine how the mass of the dark matter particle
is related to the annihilation cross section in order for the cold dark matter
constraint to be satisfied.


title:
Posets and Permutations in the Duplication-Loss Model: Minimal
  Permutations with d Descents

abstract:
  In this paper, we are interested in the combinatorial analysis of the whole
genome duplication - random loss model of genome rearrangement initiated in a
paper of Chaudhuri, Chen, Mihaescu, and Rao in SODA 2006 and continued by
Bouvel and Rossin in 2007. In this model, genomes composed of n genes are
modeled by permutations of the set of integers [1..n], that can evolve through
duplication-loss steps. It was previously shown that the class of permutations
obtained in this model after a given number p of steps is a class of
pattern-avoiding permutations of finite basis. The excluded patterns were
described as the minimal permutations with d=2^p descents, minimal being
intended in the sense of the pattern-involvement relation on permutations.
Here, we give a local and simpler characterization of the set B_d of minimal
permutations with d descents. We also provide a more detailed analysis -
characterization, bijection and enumeration - of two particular subsets of B_d,
namely the patterns in B_d of size d+2 and 2d.


title: On the NLO QCD corrections to Higgs production and decay in the MSSM

abstract:
  We present explicit analytic results for the two-loop top/stop/gluino
contributions to the cross section for the production of CP-even Higgs bosons
via gluon fusion in the MSSM, under the approximation of neglecting the Higgs
boson mass with respect to the masses of the particles circulating in the
loops. The results are obtained employing the low-energy theorem for Higgs
interactions adapted to the case of particle mixing. We discuss the validity of
the approximation used by computing the first-order correction in an expansion
in powers of the Higgs boson mass. We find that, for the lightest CP-even Higgs
boson, the gluino contribution is very well approximated by the result obtained
in the limit of vanishing Higgs mass. As a byproduct of our calculation, we
provide results for the two-loop QCD contributions to the photonic Higgs decay.


title:
Further extensions of the high-temperature expansions for the
  two-dimensional classical XY model on the triangular and the square lattices

abstract:
  The high-temperature expansions for the spin-spin correlation function of the
two-dimensional classical XY (planar rotator) model are extended by two terms,
from order 24 through order 26, in the case of the square lattice, and by five
terms, from order 15 through order 20, in the case of the triangular lattice.
The data are analyzed to improve the current estimates of the critical
parameters of the models.


title: Photometric Oscillations of Low Luminosity Red Giant Stars

abstract:
  I present details of the variations of several hundred red giant stars on
time scales of a few hours to a few days from Hubble Space Telescope (HST)
observations of a low-extinction galactic bulge sample from an intensive seven
day campaign. Variations in the red giants are shown to be a strong function of
position within the color-magnitude diagram (CMD) in accord with general
expectations from theory. Amplitudes are greater for stars with larger radii,
whether this results from higher luminosity at the same effective temperature
or lower temperature at a fixed apparent magnitude. Likewise, characteristic
time scales for the variations increase to the upper right in a CMD as does the
ratio of amplitudes measured at 606 nm compared to 814 nm. Characteristic
variation time scales are well matched by low-order radial pulsation modes. The
effective sample discussed here extends from about two magnitudes above the
bulge turnoff at which red giant radii are ~7 R/R_{\odot} at 5,000 K with
typical amplitudes of ~0.5 mmag to ~40 R/R_{\odot} at 4,000 K with amplitudes
of ~3.5 mmag. Variability characteristics are quite similar at any given
position in the CMD, and at levels in the CMD where oscillations are easily
detected nearly all red giants show such. If these variations represent
oscillations with sufficient lifetimes to derive accurate mode frequencies more
extensive observations, e.g. as should soon be provided by the Kepler Mission},
would provide a rich asteroseismic return.


title:
b anti-b Higgs production at the LHC: Yukawa corrections and the leading
  Landau singularity

abstract:
  At tree-level Higgs production in association with a b-quark pair proceeds
through the small Yukawa bottom coupling in the Standard Model. Even in the
limit where this coupling vanishes, electroweak one-loop effects, through the
top-Higgs Yukawa coupling in particular, can still trigger this reaction. This
contribution is small for Higgs masses around 120GeV but it quickly picks up
for higher Higgs masses especially because the one-loop amplitude develops a
leading Landau singularity and new thresholds open up. These effects can be
viewed as the production of a pair of top quarks which rescatter to give rise
to Higgs production through WW fusion. We study the leading Landau singularity
in detail. Since this singularity is not integrable when the one-loop amplitude
is squared, we regulate the cross section by taking into account the width of
the internal top and W particles. This requires that we extend the usual box
one-loop function to the case of imaginary masses. We show how this can be
implemented analytically in our case. We study in some detail the cross section
at the LHC as a function of the Higgs mass and show how some distributions can
be drastically affected compared to the tree-level result.


title: Jet reconstruction in hadronic collisions by Gaussian filtering

abstract:
  A new algorithm for jet finding in hadronic collisions is presented. The
algorithm, based on a Gaussian filter in $(\eta,\phi)$, is specifically
intended for use in heavy ion collisions and/or for detectors with limited
acceptance. The performance of the algorithm is compared to two conventional
algorithms, a seedless cone algorithm and a $k_\perp$ algorithm, for Pythia
simulated di-jet events in $\sqrt{s} = 200 \mathrm{GeV}$ $p + p$ collisions
with $4 \mathrm{GeV}/c \le \sqrt{Q^2} \le 16 \mathrm{GeV}/c$. The Gaussian
filter is found to perform as well as, and in some instances better than, the
conventional algorithms.


title: The M\"{o}bius Function of a Restricted Composition Poset

abstract:
  We study a poset of compositions restricted by part size under a partial
ordering introduced by Bj\"{o}rner and Stanley. We show that our composition
poset $C_{d+1}$ is isomorphic to the poset of words $A_d^*$. This allows us to
use techniques developed by Bj\"{o}rner to study the M\"{o}bius function of
$C_{d+1}$. We use counting arguments and shellability as avenues for proving
that the M\"{o}bius function is $\mu(u,w)=(-1)^{|u|+|w|}{w\choose u}_{dn}$,
where ${w\choose u}_{dn}$ is the number of $d$-normal embeddings of $u$ in $w$.
We then prove that the formal power series whose coefficients are given by the
zeta and the M\"{o}bius functions are both rational. Following in the footsteps
of Bj\"{o}rner and Reutenauer and Bj\"{o}rner and Sagan, we rely on definitions
to prove rationality in one case, and in another case we use finite-state
automata.


title: Two components of dark matter in the DAMA data

abstract:
  It is shown that the DAMA data indicate two dark matter components, one that
circulates around the galactic center (GC) and another that is emitted from the
GC. From the location of the maximum yearly variation, one can compute the
ratio of the two components.