title: Computation of Time-Periodic Solutions of the Benjamin-Ono Equation

abstract:
  We present a spectrally accurate numerical method for finding non-trivial
time-periodic solutions of non-linear partial differential equations. The
method is based on minimizing a functional (of the initial condition and the
period) that is positive unless the solution is periodic, in which case it is
zero. We solve an adjoint PDE to compute the gradient of this functional with
respect to the initial condition. We include additional terms in the functional
to specify the free parameters, which, in the case of the Benjamin-Ono
equation, are the mean, a spatial phase, a temporal phase and the real part of
one of the Fourier modes at $t=0$.
  We use our method to study global paths of non-trivial time-periodic
solutions connecting stationary and traveling waves of the Benjamin-Ono
equation. As a starting guess for each path, we compute periodic solutions of
the linearized problem by solving an infinite dimensional eigenvalue problem in
closed form. We then use our numerical method to continue these solutions
beyond the realm of linear theory until another traveling wave is reached. By
experimentation with data fitting, we identify the analytical form of the
solutions on the path connecting the one-hump stationary solution to the
two-hump traveling wave. We then derive exact formulas for these solutions by
explicitly solving the system of ODE's governing the evolution of solitons
using the ansatz suggested by the numerical simulations.


title: Heegaard Floer homology and genus one, one boundary component open books

abstract:
  We compute the Heegaard Floer homology of any rational homology 3-sphere with
an open book decomposition of the form (T,\phi), where T is a genus one surface
with one boundary component. In addition, we compute the Heegaard Floer
homology of any T^2-bundle over S^1 with first Betti number equal to one, and
we compare our results with those of Lebow on the embedded contact homology of
such torus bundles. We use these computations to place restrictions on
Stein-filllings of the contact structures compatible with such open books, to
narrow down somewhat the class of 3-braid knots with finite concordance order,
and to identify all quasi-alternating links with braid index at most 3.


title: Giant Carrier Mobility in Single Crystals of FeSb2

abstract:
  We report the giant carrier mobility in single crystals of FeSb2. Nonlinear
field dependence of Hall resistivity is well described with the two-carrier
model. Maximum mobility values in high mobility band reach ~10^5 cm^2/Vs at 8
K, and are ~10^2 cm^2/Vs at the room temperature. Our results point to a class
of materials with promising potential for applications in solid state
electronics.


title:
XMM-Newton observations of the TeV BL Lac object PKS 2155--304 in 2006:
  signature of inverse Compton X-ray emission?

abstract:
  This paper reports the first discovery of possible inverse Compoton (IC)
X-ray emission below 10 keV in the typical high-energy peaked BL Lac object
(HBL) PKS 2155--304. Two XMM-Newton observations performed in 2006 reveal that
the 0.6--10 keV X-ray spectra of the source harden ($\Delta\Gamma \sim$
0.1--0.3) at break energies of about 4 keV. The concave X-ray spectra of the
source could be easily interpretated by a mixture of a steep component (i.e.,
the high energy tail of the synchrotron emission) and a flat one (i.e., the low
energy side of the IC emission). However, the steep spectra ($\Gamma \sim$ 2.3)
in the hard X-rays indicate that the synchrotron emission still domiantes over
the IC one, while the latter is effectively present and perceived as flattening
the synchrotron spectrum in this energy range. The quasi-simultaneous
optical-UV-X-ray spectral energy distributions (SEDs) obtained with XMM-Newton
suggest that the concave X-ray spectra of the source could be the result of
down-ward shift of the synchrotron peak frequency to the optical band, incuring
the IC emisssion to become more important in the hard ($\sim 4$--10 keV) X-ray
band with respective to other cases in which the synchrotron emission peaks in
the UV-soft-X-ray range. This discovery provides a new clue for a smooth
transition between HBLs and the low-energy peaked BL Lac objects (LBLs).


title: The Physical Range of Majorana Neutrino Mixing Parameters

abstract:
  If neutrinos are Majorana fermions, the lepton mixing parameter space
consists of six mixing parameters: three mixing angles and three CP-odd phases.
A related issue concerns the physical range of the mixing parameters. What
values should these take so that all physically distinguishable mixing
scenarios are realized? We present a detailed discussion of the lepton mixing
parameter space in the case of two and three active neutrinos, and in the case
of three active and N sterile neutrinos. We emphasize that this question, which
has been a source of confusion even among "neutrino" physicists, is connected
to an unambiguous definition of the neutrino mass eigenstates. We find that all
Majorana phases can always be constrained to lie between 0 and pi, and that all
mixing angles can be chosen positive and at most less than or equal to pi/2
provided the Dirac phases are allowed to vary between -pi and pi. We illustrate
our results with several examples. Finally, we point out that, in the case of
new flavor-changing neutrino interactions, the lepton mixing parameter space
may need to be enlarged. We properly qualify this statement, and offer concrete
examples.


title:
Consensus Problems in Networks of Agents under Nonlinear Protocols with
  Directed Interaction Topology

abstract:
  The purpose of this short paper is to provide a theoretical analysis for the
consensus problem under nonlinear protocols. A main contribution of this work
is to generalize the previous consensus problems under nonlinear protocols for
networks with undirected graphs to directed graphs (information flow). Our
theoretical result is that if the directed graph is strongly connected and the
nonlinear protocol is strictly increasing, then consensus can be realized. Some
simple examples are also provided to demonstrate the validity of our
theoretical result.


title: M5 from M2

abstract:
  Recently an action based on Lie 3-algebras was proposed to describe
M2-branes. We study the case of infinite dimensional Lie 3-algebras based on
the Nambu-Poisson structure of three dimensional manifolds. We show that the
model contains self-dual 2-form gauge fields in 6 dimensions, and the result
may be interpreted as the M5-brane world-volume action.


title: Ratcheting Heat Flux against a Thermal Bias

abstract:
  Merely rocking the temperature in one heat bath can direct a steady heat flux
from cold to hot against a non-zero thermal bias in stylized nonlinear lattice
junctions that are sandwiched between two heat baths. Likewise, for an average
zero-temperature difference between the two contacts a net, ratchet-like heat
flux emerges. Computer simulations show that this very heat flux can be
controlled and reversed by suitably tailoring the frequency ($\lesssim$ 100
MHz) of the alternating temperature field.


title: Virasoro constraints and descendant Hurwitz-Hodge Integrals

abstract:
  Virasoro constraints are applied to degree zero Gromov-Witten theory of
weighted projective stacks $\mathbb{P}(1,N)$ and $\mathbb{P}(1,1,N)$ to obtain
formulas of descendant cyclic Hurwitz-Hodge integrals in higher genera.


title:
Spitzer Observations of Star Formation in the Extreme Outer Disk of M83
  (NGC5236)

abstract:
  Spitzer IRAC observations of two fields in the XUV-disk of M83 have been
recently obtained,3R_{HII} away from the center of the galaxy (R_{HII)=6.6
kpc).GALEX UV images have shown the two fields to host in-situ recent star
formation.The IRAC images are used in conjunction with GALEX data and new HI
imaging from THINGS to constrain stellar masses and ages of the UV clumps in
the fields,and to relate the local recent star formation to the reservoir of
available gas. multi wavelength photometry in the UV and mid-IR bands of 136 UV
clumps(spatial resolution >220pc) identified in the two target fields, together
with model fitting of the stellar UV-MIR SED,suggest that the clumps cover a
range of ages between a few Myr and >1Gyr with a median value around
<100Myr,and have masses in the range 10^3-3*10^6M, with a peak ~10^4.7M.The
range of observed ages,for which only a small fraction of the mass in stars
appears to have formed in the past ~10Myr, agrees with the dearth of Ha
emission observed in these outer fiel ds. At the location of our IRAC fields,
the HI map shows localized enhancement and clumping of atomic gas. A comparison
of the observed star formation with the gas reservoir shows that the UV clumps
follow the Schmidt--Kennicutt scaling law of star formation,and that star
formation is occurring in regions with gas dens ities at approximately (within
a factor of a few) the critical density value de -rived according to the Toomre
Q gravitational stability criterion. The signifi cant 8 micron excess in
several of the clumps (16% of the total by number accou nting for ~67% of the 8
micron flux)) provides evidence for the existence of dust in these remote
fields, in agreement with results for other galaxies. Furt hermore, we observe
a relatively small excess of emission at 4.5 micron in the clumps...


title: Separating twists and the Magnus representation of the Torelli group

abstract:
  The Magnus representation of the Torelli subgroup of the mapping class group
of a surface is a homomorphism r: I_{g,1} -> GL_{2g}(Z[H]). Here H is the first
homology group of the surface. This representation is not faithful; in
particular, Suzuki previously described precisely when the commutator of two
Dehn twists about separating curves is in the kernel of r. Using the trace of
the Magnus representation, we apply a new method of showing that two
endomorphisms generate a free group to prove that the images of two positive
separating multitwists under the Magnus representation either commute or
generate a free group, and we characterize when each case occurs.


title:
The White Mountain Polarimeter Telescope and an Upper Limit on CMB
  Polarization

abstract:
  The White Mountain Polarimeter (WMPol) is a dedicated ground-based microwave
telescope and receiver system for observing polarization of the Cosmic
Microwave Background. WMPol is located at an altitude of 3880 meters on a
plateau in the White Mountains of Eastern California, USA, at the Barcroft
Facility of the University of California White Mountain Research Station.
Presented here is a description of the instrument and the data collected during
April through October 2004. We set an upper limit on $E$-mode polarization of
14 $\mu\mathrm{K}$ (95% confidence limit) in the multipole range
$170<\ell<240$. This result was obtained with 422 hours of observations of a 3
$\mathrm{deg}^2$ sky area about the North Celestial Pole, using a 42 GHz
polarimeter. This upper limit is consistent with $EE$ polarization predicted
from a standard $\Lambda$-CDM concordance model.


title:
Dangerous Liouville Wave -- exactly marginal but non-conformal
  deformation

abstract:
  We give a non-trivially interacting field theory example of scale invariant
but non-conformal field theory. The model is based on the exactly solvable
Liouville field theory coupled with free scalars deformed by an exactly
marginal operator. We show non-vanishing of the trace of the energy-momentum
tensor by using the quantum Schwinger-Dyson equation for the Liouville field
theory, which is a sophistication of the quantum higher equations of motion for
the Liouville field theory introduced by Alyosha Zamolodchikov. Possibly
dangerous implications for the super-critical string theory will be discussed.


title: Overlapping Community Detection in Bipartite Networks

abstract:
  Recent researches have discovered that rich interactions among entities in
nature and society bring about complex networks with community structures.
Although the investigation of the community structures has promoted the
development of many successful algorithms, most of them only find separated
communities, while for the vast majority of real-world networks, communities
actually overlap to some extent. Moreover, the vertices of networks can often
belong to different domains as well. Therefore, in this paper, we propose a
novel algorithm BiTector Bi-community De-tector) to efficiently mine
overlapping communities in large-scale sparse bipartite networks. It only
depends on the network topology, and does not require any priori knowledge
about the number or the original partition of the network. We apply the
algorithm to real-world data from different domains, showing that BiTector can
successfully identifies the overlapping community structures of the bipartite
networks.


title: Alkanethiol-Based Single-Molecule Transistors

abstract:
  The transport properties of unsubstituted and amino-substituted butanethiol
molecules sandwiched between Au electrodes are investigated by using
first-principles approaches. New states are observed around the Fermi levels
when -NH2 is substituted for -H in the bridging butanethiol. The
amino-substituted states lead to a sharp increase of the current which is
credited to the resonant tunneling in the junction. We observe a novel
conductance peak at VSD = 0.1 V and negative differential resistance (NDR) in a
certain range of source-drain bias. In addition to the I-VSD characteristics,
we also investigate the current as a function of gate voltage (I-VG) and find
that, for a fixed source-drain bias (VSD = 0.01 V), the gate voltage can
modulate the conductance by up to 30 times in the amino-substituted butanethiol
junction. These I-VG characteristics suggest that the amino-substituted
butanethiol molecular junction may be a promising candidate for field-effect
transistors.


title: New hook length formulas for binary trees

abstract:
  We find two new hook length formulas for binary trees. The particularity of
our formulas is that the hook length $h_v$ appears as an exponent.


title:
On the Log-Concavity of Hilbert Series of Veronese Subrings and Ehrhart
  Series

abstract:
  For every positive integer $n$, consider the linear operator $\U_{n}$ on
polynomials of degree at most $d$ with integer coefficients defined as follows:
if we write $\frac{h(t)}{(1 - t)^{d + 1}} = \sum_{m \geq 0} g(m) t^{m}$, for
some polynomial $g(m)$ with rational coefficients, then $\frac{\U_{n}h(t)}{(1-
t)^{d + 1}} = \sum_{m \geq 0} g(nm) t^{m}$. We show that there exists a
positive integer $n_{d}$, depending only on $d$, such that if $h(t)$ is a
polynomial of degree at most $d$ with nonnegative integer coefficients and
$h(0) \geq 1$, then for $n \geq n_{d}$, $\U_{n}h(t)$ has simple, real, strictly
negative roots and positive, strictly log concave and strictly unimodal
coefficients. Applications are given to Ehrhart $\delta$-polynomials and
unimodular triangulations of dilations of lattice polytopes, as well as Hilbert
series of Veronese subrings of Cohen--MacCauley graded rings.


title: Super edge-graceful paths

abstract:
  A graph $G(V,E)$ of order $|V|=p$ and size $|E|=q$ is called super
edge-graceful if there is a bijection $f$ from $E$ to $\{0,\pm 1,\pm 2,...,\pm
\frac{q-1}{2}\}$ when $q$ is odd and from $E$ to $\{\pm 1,\pm 2,...,\pm
\frac{q}{2}\}$ when $q$ is even such that the induced vertex labeling $f^*$
defined by $f^*(x) = \sum_{xy\in E(G)}f(xy)$ over all edges $xy$ is a bijection
from $V$ to $\{0,\pm 1,\pm 2...,\pm \frac{p-1}{2}\}$ when $p$ is odd and from
$V$ to $\{\pm 1,\pm 2,...,\pm \frac{p}{2}\}$ when $p$ is even. \indent We prove
that all paths $P_n$ except $P_2$ and $P_4$ are super edge-graceful.


title:
Size induced change-over from first to second order magnetic phase
  transition in La0.67Ca0.33MnO3 nanoparticles

abstract:
  In this report we show that in the perovskite manganite La_{1-x}Ca_{x}MnO_3
for a fixed x \approx 0.33, the magnetic transition changes over from first
order to second order on reducing the particle size to nearly few tens of a
nanometer. The change-over is brought about only by reducing the size and with
no change in the stoichiometry. The size reduction to an average size of about
15 nm retains the ferromagnetic state albeit with somewhat smaller saturation
magnetization and the ferromagnetic transition temperature T_{C} is suppressed
by a small amount (4%). The magnetization of the nanoparticles near T_{C}
follow the scaling equation $M/|\epsilon|^\beta =
f_\pm(H/|\epsilon|^{\gamma+\beta})$, where, $\epsilon = |T-T_C|/T_C$. The
critical exponents, associated with the transition have been obtained from
modified Arrott plots and they are found to be $\beta=0.47\pm 0.01$ and
$\gamma=1.06\pm 0.03$. From a plot of M vs H at T_{C} we find the exponent
$\delta=3.10 \pm 0.13$. All the exponents are close to the mean field values.
The change-over of the order of the transition has been attributed to a
lowering of the value of the derivative dT_{C}/dP due to an increased pressure
in the nanoparticles arising due to size reduction. This effect acts in tandem
with the rounding off effect due to random strain in the nanoparticles.


title:
Specific heat of the iron-based high-$T_c$ superconductor
  SmO$_{1-x}$F$_x$FeAs

abstract:
  The specific heat $C(T)$ of new iron-based high-$T_c$ superconductor
SmO$_{1-x}$F$_x$FeAs ($0 \leq x \leq 0.2$) was systematically studied. For
undoped $x$ = 0 sample, a specific heat jump was observed at 130 K. This is
attributed to the structural or spin-density-wave (SDW) transition, which also
manifests on resistivity as a rapid drop. However, this jump disappears with
slight F doping in $x$ = 0.05 sample, although the resistivity drop still
exists. The specific heat $C/T$ shows clear anomaly near $T_c$ for $x$ = 0.15
and 0.20 superconducting samples. Such anomaly has been absent in
LaO$_{1-x}$F$_x$FeAs. For the parent compound SmOFeAs, $C(T)$ shows a sharp
peak at 4.6 K, and with electron doping in $x$ = 0.15 sample, this peak shifts
to 3.7 K. It is interpreted that such a sharp peak results from the
antiferromagnetic ordering of Sm$^{3+}$ ions in this system, which mimics the
electron-doped high-$T_c$ cuprate Sm$_{2-x}$Ce$_x$CuO$_{4-\delta}$.


title:
Fine-grained parallelization of similarity search between protein
  sequences

abstract:
  This report presents the implementation of a protein sequence comparison
algorithm specifically designed for speeding up time consuming part on parallel
hardware such as SSE instructions, multicore architectures or graphic boards.
Three programs have been developed: PLAST-P, TPLAST-N and PLAST-X. They provide
equivalent results compared to the NCBI BLAST family programs (BLAST-P,
TBLAST-N and BLAST-X) with a speed-up factor ranging from 5 to 10.


title:
The role of metallic impurities in oxide semiconductors:
  first-principles calculations and PAC experiments

abstract:
  We report an ab-initio comparative study of the electric-field-gradient
tensor (EFG) and structural relaxations introduced by acceptor (Cd) and donor
(Ta) impurities when they replace cations in a series of binary oxides: TiO2,
SnO2, and In2O3. Calculations were performed with the Full-Potential
Linearized-Augmented Plane Waves method that allows us to treat the electronic
structure and the atomic relaxations in a fully self-consistent way. We
considered different charge states for each impurity and studied the dependence
on these charge states of the electronic properties and the structural
relaxations. Our results are compared with available data coming from PAC
experiments and previous calculations, allowing us to obtain a new insight on
the role that metal impurities play in oxide semiconductors. It is clear from
our results that simple models can not describe the measured EFGs at impurities
in oxides even approximately.


title: The diffeomorphism groups of the real line are pairwise bihomeomorphic

abstract:
  We prove that the group D^r(R) of C^r diffeomorphisms of the real line,
endowed with the compact-open and Whitney C^r topologies, is bihomeomorphic to
the group H(R) of homeomorphisms of the real line endowed with the compact-open
and Whitney topologies. This implies that the diffeomorphism group D^r(R)
endowed with the Whitney C^r topology is homeomorphic to the countable
box-power of the separable Hilbert space.


title:
Ab initio study of ferromagnetism induced by magnetic impurities in
  rutile TiO2

abstract:
  Using the first-principles density-functional approach, magnetic properties
of Mn-, Fe-, Co-, and Ni-doped rutile TiO2 were investigated for two different
impurity concentrations (25% and 6.25%). Calculations were performed with the
Full-Potential Linearized-Augmented Plane Waves (FLAPW) method, assuming that
the magnetic impurities substitutionally replace the Ti ions. Our results show
that the systems (with the exception of Ni-doped TiO2) are ferromagnetic. We
also found that polarization mainly occurs at the impurity sites, and the
magnetic moments of the impurities are independent of the impurity
concentration.


title:
On The Behavior of Subgradient Projections Methods for Convex
  Feasibility Problems in Euclidean Spaces

abstract:
  We study some methods of subgradient projections for solving a convex
feasibility problem with general (not necessarily hyperplanes or half-spaces)
convex sets in the inconsistent case and propose a strategy that controls the
relaxation parameters in a specific self-adapting manner. This strategy leaves
enough user-flexibility but gives a mathematical guarantee for the algorithm's
behavior in the inconsistent case. We present numerical results of
computational experiments that illustrate the computational advantage of the
new method.


title: Pressure-induced commensurate magnetic order in multiferroic $HoMn_2O_5$

abstract:
  The pressure ($p$) -- temperature ($T$) phase diagram for microscopic
magnetism in the multiferroic compound HoMn$_{2}$O$_{5}$ was established using
neutron diffraction measurements under a hydrostatic pressure up to 1.25 GPa.
At ambient pressure, incommensurate--commensurate--incommensurate magnetic
phase transitions occur successively with decreasing temperature. Upon applying
pressure, the incommensurate phase at the lowest temperature almost decreases
and the commensurate phase appears. The $p$ -- $T$ phase diagram established
shows excellent agreement with the recently reported $p$ -- $T$ dielectric
phase diagram, where ferroelectricity is induced by applying pressure. We also
found that the $p$ -- $T$ magnetic phase diagram is quite similar to the
previously obtained magnetic field-temperature phase diagram.


title: Magnetic monopoles on manifolds with boundary

abstract:
  Kapustin and Witten associate a Hecke modification of a holomorphic bundle
over a Riemann surface to a singular monopole on a Riemannian surface times an
interval satisfying prescribed boundary conditions. We prove existence and
uniqueness of singular monopoles satisfying prescribed boundary conditions for
any given Hecke modification data confirming the underlying geometric invariant
theory principle.


title: On generic frequency decomposition. Part 1: vectorial decomposition

abstract:
  The famous Fourier theorem states that, under some restrictions, any periodic
function (or real world signal) can be obtained as a sum of sinusoids, and
hence, a technique exists for decomposing a signal into its sinusoidal
components. From this theory an entire branch of research has flourished: from
the Short-Time or Windowed Fourier Transform to the Wavelets, the Frames, and
lately the Generic Frequency Analysis. The aim of this paper is to take the
Frequency Analysis a step further. It will be shown that keeping the same
reconstruction algorithm as the Fourier Theorem but changing to a new computing
method for the analysis phase allows the generalization of the Fourier Theorem
to a large class of nonorthogonal bases. New methods and algorithms can be
employed in function decomposition on such generic bases. It will be shown that
these algorithms are a generalization of the Fourier analysis, i.e. they are
reduced to the familiar Fourier tools when using orthogonal bases. The
differences between this tool and the wavelets and frames theories will be
discussed. Examples of analysis and reconstruction of functions using the given
algorithms and nonorthogonal bases will be given. In this first part the focus
will be on vectorial decomposition, while the second part will be on phased
decomposition. The phased decomposition thanks to a single function basis has
many interesting consequences and applications.


title: Monodromy Filtrations and the Topology of Tropical Varieties

abstract:
  We find restrictions on the topology of tropical varieties that arise from a
certain natural class of varieties. We develop a theory of tropical
degenerations that is a nonconstant coefficient analogue of Tevelev's theory of
tropical compactifications, and use it to construct normal crossings
degenerations of a subvariety X of a torus, under mild hypotheses on X. These
degenerations allow us to construct a natural, "multiplicity-free"
parameterization of Trop(X) by a topological space \Gamma_X. We give a
geometric interpretation of the cohomology of \Gamma_X in terms of the action
of a monodromy operator on the cohomology of X. This gives bounds on the Betti
numbers of $\Gamma_X$ in terms of the Betti numbers of $X$. When $X$ is a
sufficiently general complete intersection, this allows us to show that the
cohomology of Trop(X) vanishes in degree less than dim(X). In addition, we give
a description for the top power of the monodromy operator acting on middle
cohomology in terms of the volume pairing on $\Gamma_X$.


title: Symplectic Dirac Operators on Hermitian Symmetric Spaces

abstract:
  We describe the shape of the symplectic Dirac operators on Hermitian
symmetric spaces. For this, we consider these operators as families of
operators that can be handled more easily than the original ones.


title: Two-field K\"ahler moduli inflation on large volume moduli stabilization

abstract:
  In this paper we present a two-field inflation model, which distinguishes
itself with a non-canonical kinetic lagrangian and comes from the large volume
approach to the moduli stabilization in flux compactification of type IIB
superstring on a Calabi-Yau orientifold of $h^{(1,2)} > h^{(1,1)}\geq 4$. The
K\"ahler moduli are classified as volume modulus, heavy moduli and two light
moduli. The axion-dilaton, complex structure moduli and all heavy K\"ahler
moduli including the volume modulus are frozen by nonperturbatively corrected
flux superpotential and the $\alpha^\prime$-corrected K\"ahler potential in the
large volume limit. The minimum of the scalar potential at which the heavy
moduli are stabilized provides the dominant potential energy for the survived
light K\"ahler moduli. We consider a simplified case where the axionic
components in the light K\"ahler moduli are further stabilized at the potential
minimum and only the geometrical components are taken as the scalar fields to
drive an assisted-like inflation. For a certain range of moduli stabilization
parameters and inflation initial conditions, we obtain a nearly flat power
spectrum of the curvature perturbation, with $n_s\approx 0.96$ at Hubble-exit,
and an inflationary energy scale of $3 \times 10^{14}$ GeV. In our model,
significant correlation exists between the curvature and isocurvature
perturbations on super-Hubble scales so that at the end of inflation a great
deal of the curvature power spectrum originates from this correlation.


title:
Performance of a Lattice Quantum Chromodynamics Kernel on the Cell
  Processor

abstract:
  The implementation of a proof-of-concept Lattice Quantum Chromodynamics
kernel on the Cell processor is described in detail, illustrating issues
encountered in the porting process. The resulting code performs up to 45GFlop/s
per socket, indicating that the Cell processor is likely to be a good platform
for future Lattice QCD calculations.


title:
Reexamination for the calculation of elliptic flow and other fourier
  harmonics

abstract:
  We have argued that the azimuthal symmetry and asymmetry components in
fourier expansion of particle momentum azimuthal distribution, $v_n$ (n=0, 1,
2, ...), should be calculated as an average of $cos(n\phi)$ first over
particles in an event and then over events (event-wise average) rather than "an
average over all particles in all events" (particle-wise average). In case of
large centrality (multiplicity) bin the particle-wise average is not accurate
because the influence (fluctuation) of particle multiplicity was not taken into
account.


title: Search for $B \to \pi \ell^+\ell^-$ Decays at Belle

abstract:
  We present a search for the B-> pi e^+ e^- and B-> pi \mu^+ \mu^- decays,
with a data sample of 657 million BBbar pairs collected with the Belle detector
at the KEKB $e^+e^-$ collider. Signal events are reconstructed from a charged
or a neutral pion candidate and a pair of oppositely charged electrons or
muons. No significant signal is observed and we set the upper limit on the
isospin-averaged branching fraction BF(B -> \pi \ell^+\ell^-) < 6.2x10^-8 at
the 90% confidence level.


title: Conjugacy Classes of Centralizers in $G_2$

abstract:
  Let $G$ be an algebraic group of type $G_2$ over a field $k$ of
characteristic $\neq 2,3$. In this paper we calculate centralizers of
semisimple elements in anisotropic $G_2$. Using these, we show explicitly that
there are six conjugacy classes of centralizers in the compact real form of
$G_2$.


title: The Problem of Modelling of Economic Dynamics in Differential Form

abstract:
  Traditional models of macroeconomic dynamics are fundamentally incorrect. The
reason lies in a misunderstanding of peculiarities of the analysis of
infinitesimal quantities. However, even those types of solutions that are
envisaged by the above-mentioned models are nonrepresentative in the sense of
the reflection of realities. It became obvious that the techniques of the
theory of linear differential equations were insufficient here. Accordingly,
the scientists' attention switched to the theory of nonlinear differential
equations. At the same time, balance and, accordingly, the model with matrix
properties are objectively inherent in the economic system. For the reduction
of this model to a differential form, there exist rather elementary means that
proved to be unclaimed. Macroeconomic rhetoric - the power of the accelerator,
a lag on the part of demand, etc. - accompanied by the use of a lot of abstract
coefficients prevailed. However, there is no organic interrelation between
matrix and nonlinear differential equations. On the contrary, it can be said
that linear theory of integral equations originated in matrix analysis. The
Fredholm linear integral equation of the second kind with a parameter-dependent
kernel proves to be rather representative with regard to the class of possible
solutions. It seems that it can be used for the description of any zigzags of
the economy. The price one has to pay for this is the nontriviality of existing
theory.


title:
Detection of mesogranulation at the upper chromosphere from SOHO/SUMER
  observations

abstract:
  We have analyzed a time series of spectra in the hydrogen Lyman lines and the
Lyman continuum obtained by the Solar Ultraviolet Measurements of Emitted
Radiation (SUMER) spectrometer on the SOlar Heliospheric Observatory (SOHO).
The time series of about 2 hours and 22 minutes was obtained on 1999 March 9 in
a quiet region near the center of the solar disk. For our analysis, we have
selected a Lyman continuum window around 907 A, and the five Lyman lines: Ly5
(937.8 A), Ly7 (926.2 A), Ly9 (920.9 A), Ly11 (918.1 A), and Ly15 (915.3 A). A
Fast Fourier analysis has been performed in the spatial domain, all along the
slit length used, for all the spectra and for the total duration of the
observations. We have detected a significant periodic spatial variations with
Fourier transform power peaks around 9-10 arcsec and at 4 arcsec. They
correspond to the scale of the mesogranulation structure and the width of the
supergranular boundary, respectively. For the first time, this provides
evidence for the existence of a meso-scale in the upper chromosphere, of the
same size as observed in the photosphere and lower chromosphere by earlier
studies. We find from the analysis that there seems to be no signature of any
temporal evolution associated with the mesogranules, at least not during our
observing period. This result suggests that the life time of mesogranules will
be several hours or more, which confirms the earlier findings. In addition, we
notice that the size (9-10 arcsec) of the mesocells appears to be the same in
all Lyman lines and in the continuum, which are formed at different depths in
the chromosphere.


title: Efficient scheme for atomic entangled states with cavity QED system

abstract:
  A protocol is proposed to generate atomic entangled states in a cavity QED
system. It utilizes Raman transitions or stimulated Raman adiabatic passages
between two systems to entangle the ground states of two three-state
$\Lambda$-type atoms trapped in a single mode cavity. It does not need the
measurements on cavity field nor atomic detection and can be implemented in a
deterministic fashion. Since the present protocol is insensitive to both cavity
decay and atomic spontaneous emission, the produced entangled states may have
some interesting applications in quantum information processing.


title: Semi-shifted hybrid inflation with B-L cosmic strings

abstract:
  We discuss a new inflationary scenario which is realized within the extended
supersymmetric Pati-Salam model which yields an acceptable b-quark mass for
universal boundary conditions and mu>0 by modestly violating Yukawa unification
and leads to new shifted, new smooth, or standard-smooth hybrid inflation.
Inflation takes place along a "semi-shifted" classically flat direction on
which the U(1)_{B-L} gauge group remains unbroken. After the end of inflation,
U(1)_{B-L} breaks spontaneously and a network of local cosmic strings, which
contribute a small amount to the curvature perturbation, is produced. We show
that, in minimal supergravity, this "semi-shifted" inflationary scenario is
compatible with a recent fit to data which uses field-theory simulations of a
local string network. Taking into account the requirement of gauge unification,
we find that, for spectral index n_s=1, the predicted fractional contribution
f_{10} of strings to the temperature power spectrum at multipole l=10 is about
0.039. Also, for f_{10}=0.10, which is the best-fit value, we obtain that n_s
is about 1.0254. Spectral indices lower than about 0.98 are excluded and blue
spectra are slightly favored. Magnetic monopoles are not formed at the end of
semi-shifted hybrid inflation.


title: Jensen Shannon divergence as a measure of the degree of entanglement

abstract:
  The notion of distance in Hilbert space is relevant in many scenarios. In
particular, distances between quantum states play a central role in quantum
information theory. An appropriate measure of distance is the quantum Jensen
Shannon divergence (QJSD) between quantum states. Here we study this distance
as a geometrical measure of entanglement and apply it to different families of
states.


title: Hybridization Effects in Ni-Mn based Shape Memory Alloys: XAFS Study

abstract:
  Martensitic and magnetic properties of ferromagnetic shape memory alloys are
known to depend up on structural modulations and associated changes in the
Fermi surface. These modulations although periodic and spanning over multiple
unit cells, involve movement of atoms typically of the order of 0.01A.
Therefore X-ray Absorption Fine Structure (XAFS) is an ideal tool to map both,
local atomic movements and changes in density of states (DOS) due to changing
hybridization as the system transforms from austenitic to martensitic phase.
This paper presents a compilation of our XAFS studies on the Ni-Mn based shape
memory alloys. A complete description of the changes in local structure around
the constituent metal ions in the following alloy compositions: Ni2+xMn1-xGa,
Ni2Mn1.4Sn0.6 and Ni2Mn1.4In0.6 in the austenitic and martensitic phases have
been obtained. The results give the new experimental evidence for the crucial
hybridization component that influences and leads to structural transition in
these Ni-Mn based Heusler alloys.


title:
Search for ttbar resonances in the lepton plus jets final state in ppbar
  collisions at sqrt{s}=1.96TeV

abstract:
  We present a search for a narrow-width heavy resonance decaying into top
quark pairs X->ttbar in ppbar collisions at sqrt{s}=1.96TeV using approximately
0.9fb^-1 of data collected with the D0 detector at the Fermilab Tevatron
Collider. This analysis considers ttbar candidate events in the lepton plus
jets channel with at least one identified b jet and uses the ttbar invariant
mass distribution to search for evidence of resonant production. We find no
evidence for a narrow resonance X decaying to ttbar. Therefore, we set upper
limits on sigma*B(X->ttbar) for different hypothesized resonance masses using a
Bayesian approach. For a Topcolor-assisted technicolor model, the existence of
a leptophobic Z' boson with mass M_Z'<700GeV and width Gamma_Z'=0.012 M_Z' can
be excluded at the 95% C.L.


title: Asymptotic Positivity of Hurwitz Product Traces

abstract:
  Consider the polynomial $tr (A + tB)^m$ in $t$ for positive hermitian
matrices $A$ and $B$ with $m \in \N$. The Bessis-Moussa-Villani conjecture (in
the equivalent form of Lieb and Seiringer) states that this polynomial has
nonnegative coefficients only. We prove that they are at least asymptotically
positive, for the nontrivial case of $AB \neq 0$. More precisely, we show that
the $k$-th coefficient is positive for all integer $m \geq m_0$, where $m_0$
depends on $A$, $B$ and $k$.


title: Applications of information theory in plant disease management

abstract:
  Information theory is a branch of probability and statistics involving the
analysis of communications. Information theory enables us to analyze and
quantify the information content of predictions made in the context of plant
disease management and related disciplines. In this article, some applications
of information theory in plant disease management are outlined.


title:
Cayley decompositions of lattice polytopes and upper bounds for
  h^*-polynomials

abstract:
  We give an effective upper bound on the h^*-polynomial of a lattice polytope
in terms of its degree and leading coefficient, confirming a conjecture of
Batyrev. We deduce this bound as a consequence of a strong Cayley decomposition
theorem which says, roughly speaking, that any lattice polytope with a large
multiple that has no interior lattice points has a nontrivial decomposition as
a Cayley sum of polytopes of smaller dimension. In an appendix, we interpret
this result in terms of adjunction theory for toric varieties.


title: $S$ Parameter in the Holographic Walking/Conformal Technicolor

abstract:
  We explicitly calculate the $S$ parameter in entire parameter space of the
holographic walking/conformal technicolor (W/C TC), based on the deformation of
the holographic QCD by varying the anomalous dimension from $\gamma_m \simeq 0$
through $\gamma_m \simeq 1$ continuously. The $S$ parameter is given as a
positive monotonic function of $\xi$ which is fairly insensitive to $\gamma_m$
and continuously vanishes as $S \sim \xi^2 \to 0$ when $\xi \to 0$, where $\xi$
is the vacuum expectation value of the bulk scalar field at the infrared
boundary of the 5th dimension $z=z_m$ and is related to the mass of (techni-)
$\rho$ meson ($M_\rho$) and the decay constant ($f_\pi$) as $\xi \sim f_\pi z_m
\sim f_\pi/M_\rho$ for $\xi \ll 1$. However, although $\xi$ is related to the
techni-fermion condensate $\condense$, we find no particular suppression of
$\xi$ and hence of $S$ due to large $\gamma_m$, based on the correct
identification of the renormalization-point dependence of $\condense$ in
contrast to the literature. Then we argue possible behaviors of $f_\pi/M_\rho$
as $\condense \to 0$ near the conformal window characterized by the Banks-Zaks
infrared fixed point in more explicit dynamics with $\gamma_m \simeq 1$. It is
a curious coincidence that the result from ladder Schwinger-Dyson and
Bethe-Salpeter equations well fits in the parameter space obtained in this
paper. When $f_\pi/M_\rho \to 0$ is realized, the holography suggests a novel
possibility that $f_\pi$ vanishes much faster than the dynamical mass $m$ does.


title:
Origin of Plateau and Species dependence of Laser-Induced High-Energy
  Photoelectron Spectra

abstract:
  We analyzed the energy and momentum distributions of laser-induced
high-energy photoelectrons of alkali and rare gas atoms. For the plateau
electrons with energies above $4U_p$, ($U_p$ is the ponderomotive energy), in
the tunneling ionization regime, we showed that they originate from the
backscattering of laser-induced returning electrons. Using the differential
elastic scattering cross sections between the target ion with \emph{free}
electrons, we explain experimental observations of whether the plateau electron
spectra is flat or steeply descending, and their dependence on species and
laser intensity. This quantitative rescattering theory can be used to obtain
energy and momentum distributions of plateau electrons without the need of
solving the time-dependent Schr\"{o}dinger equation, but with similar accuracy.


title:
Comment on "Guiding, Focusing, and Sensing on the Subwavelength Scale
  Using Metallic Wire Arrays"

abstract:
  This is a comment on "Guiding, Focusing, and Sensing on the Subwavelength
Scale Using Metallic Wire Arrays" by G. Shvets, S. Trendafilov, J. B. Pendry
and A. Sarychev published in Phys. Rev. Lett. 99, 053903 (2007), which
demonstrates that the endoscope proposed in the letter does not demonstrate
satisfactory subwavelength imaging performance.


title: Constructions for Clumps Statistics

abstract:
  We consider a component of the word statistics known as clump; starting from
a finite set of words, clumps are maximal overlapping sets of these
occurrences. This parameter has first been studied by Schbath with the aim of
counting the number of occurrences of words in random texts. Later work with
similar probabilistic approach used the Chen-Stein approximation for a compound
Poisson distribution, where the number of clumps follows a law close to
Poisson. Presently there is no combinatorial counterpart to this approach, and
we fill the gap here. We emphasize the fact that, in contrast with the
probabilistic approach which only provides asymptotic results, the
combinatorial approach provides exact results that are useful when considering
short sequences.


title:
Phase Transition in the 1d Random Field ising model with long range
  interaction

abstract:
  We study the one dimensional Ising model with ferromagnetic, long range
interaction which decays as |i-j|^{-2+a}, 1/2< a<1, in the presence of an
external random filed. we assume that the random field is given by a collection
of independent identically distributed random variables, subgaussian with mean
zero. We show that for temperature and strength of the randomness (variance)
small enough with P=1 with respect to the distribution of the random fields
there are at least two distinct extremal Gibbs measures.


title: Landau levels on the 2D torus: a numerical approach

abstract:
  A numerical method is presented which allows to compute the spectrum of the
Schroedinger operator for a particle constrained on a two dimensional flat
torus under the combined action of a transverse magnetic field and any
conservative force. The method employs a fast Fourier transform to accurately
represent the momentum variables and takes into account the twisted boundary
conditions required by the presence of the magnetic field. An accuracy of
twelve digits is attained even with coarse grids. Landau levels are reproduced
in the case of a uniform field satisfying Dirac's condition. A new fine
structure of levels within the single Landau level is formed when the field has
a sinusoidal component with period commensurable to the integer magnetic
charge.


title: Entanglement production with Bose atoms in optical lattices

abstract:
  A method of entanglement production is suggested, based on the resonant
generation of topological modes in systems with Bose-Einstein condensates
trapped in optical or magnetic lattices. The method makes it possible to
regulate the strength of entanglement production as well as to govern its time
variation. This method can serve as a practical tool for quantum information
processing and quantum computing.


title: Near-horizon brane-scan revived

abstract:
  In 1987 two versions of the brane-scan of D-dimensional super p-branes were
put forward. The first pinpointed those (p,D) slots consistent with
kappa-symmetric Green-Schwarz type actions; the second generalized the
"membrane at the end of the universe" idea to all those superconformal groups
describing p-branes on the boundary of AdS_{p+2} x S^{D-p-2}. Although the
second version predicted D3 and M5 branes in addition to those of the first, it
came unstuck because the 1/2 BPS solitonic branes failed to exhibit the
required symmetry enhancement in the near-horizon limit, except in the
non-dilatonic cases (p=2,D=11), (p=3,D=10) and (p=5,D=11). Just recently,
however, it has been argued that the fundamental D=10 heterotic string does
indeed display a near-horizon enhancement to OSp(8|2) as predicted by the
brane-scan, provided alpha' corrections are taken into account. If this logic
could be extended to the other strings and branes, it would resolve this
21-year-old paradox and provide new AdS/CFT dualities, which we tabulate.


title: Geometric dynamics of Vlasov kinetic theory and its moments

abstract:
  The Vlasov equation of kinetic theory is introduced and the Hamiltonian
structure of its moments is presented. Then we focus on the geodesic evolution
of the Vlasov moments. As a first step, these moment equations generalize the
Camassa-Holm equation to its multi-component version. Subsequently, adding
electrostatic forces to the geodesic moment equations relates them to the
Benney equations and to the equations for beam dynamics in particle
accelerators. Next, we develop a kinetic theory for self assembly in
nano-particles. Darcy's law is introduced as a general principle for
aggregation dynamics in friction dominated systems (at different scales). Then,
a kinetic equation is introduced for the dissipative motion of isotropic
nano-particles. The zeroth-moment dynamics of this equation recovers the
classical Darcy's law at the macroscopic level. A kinetic-theory description
for oriented nano-particles is also presented. At the macroscopic level, the
zeroth moments of this kinetic equation recover the magnetization dynamics of
the Landau-Lifshitz-Gilbert equation. The moment equations exhibit the
spontaneous emergence of singular solutions (clumpons) that finally merge in
one singularity. This behaviour represents aggregation and alignment of
oriented nano-particles. Finally, the Smoluchowski description is derived from
the dissipative Vlasov equation for anisotropic interactions. Various levels of
approximate Smoluchowski descriptions are proposed as special cases of the
general treatment. As a result, the macroscopic momentum emerges as an
additional dynamical variable that in general cannot be neglected.


title:
Hyperbolic attractor of Smale-Williams type in a system of two coupled
  non-autonomous amplitude equations

abstract:
  Recently, a system with uniformly hyperbolic attractor of Smale-Williams type
has been suggested [Kuznetsov, Phys. Rev. Lett., 95, 144101, 2005]. This system
consists of two coupled non-autonomous van der Pol oscillators and admits
simple physical realization. In present paper we introduce amplitude equations
for this system and prove that the attractor of the system of amplitude
equations is also uniformly hyperbolic. Also we represent qualitative
illustrations as well as quantitative characteristics of a chaotic dynamics on
this attractor.


title: Causal inference using the algorithmic Markov condition

abstract:
  Inferring the causal structure that links n observables is usually based upon
detecting statistical dependences and choosing simple graphs that make the
joint measure Markovian. Here we argue why causal inference is also possible
when only single observations are present.
  We develop a theory how to generate causal graphs explaining similarities
between single objects. To this end, we replace the notion of conditional
stochastic independence in the causal Markov condition with the vanishing of
conditional algorithmic mutual information and describe the corresponding
causal inference rules.
  We explain why a consistent reformulation of causal inference in terms of
algorithmic complexity implies a new inference principle that takes into
account also the complexity of conditional probability densities, making it
possible to select among Markov equivalent causal graphs. This insight provides
a theoretical foundation of a heuristic principle proposed in earlier work.
  We also discuss how to replace Kolmogorov complexity with decidable
complexity criteria. This can be seen as an algorithmic analog of replacing the
empirically undecidable question of statistical independence with practical
independence tests that are based on implicit or explicit assumptions on the
underlying distribution.


title: Photon-tagged jet measurements in Pb+Pb collisions with the CMS detector

abstract:
  Presented are the results of a detailed study for a complete simulation of
the CMS detectors at the LHC in view of the expected modification of jet
fragmentation functions in central Pb+Pb collisions at (s_NN)**0.5=5.5 TeV
compared to the vacuum (p+p) case. The study is based on photon-jet events,
using the correlation between isolated high-transverse energy (E_T>70 GeV)
photons and fully reconstructed jets, based on the information provided by the
CMS calorimeters and silicon tracker.


title: Word-Based Text Compression

abstract:
  Today there are many universal compression algorithms, but in most cases is
for specific data better using specific algorithm - JPEG for images, MPEG for
movies, etc. For textual documents there are special methods based on PPM
algorithm or methods with non-character access, e.g. word-based compression. In
the past, several papers describing variants of word-based compression using
Huffman encoding or LZW method were published. The subject of this paper is the
description of a word-based compression variant based on the LZ77 algorithm.
The LZ77 algorithm and its modifications are described in this paper. Moreover,
various ways of sliding window implementation and various possibilities of
output encoding are described, as well. This paper also includes the
implementation of an experimental application, testing of its efficiency and
finding the best combination of all parts of the LZ77 coder. This is done to
achieve the best compression ratio. In conclusion there is comparison of this
implemented application with other word-based compression programs and with
other commonly used compression programs.


title: Entropic particle transport in periodic channels

abstract:
  The dynamics of Brownian motion has widespread applications extending from
transport in designed micro-channels up to its prominent role for inducing
transport in molecular motors and Brownian motors. Here, Brownian transport is
studied in micro-sized, two dimensional periodic channels, exhibiting
periodically varying cross sections. The particles in addition are subjected to
an external force acting alongside the direction of the longitudinal channel
axis. For a fixed channel geometry, the dynamics of the two dimensional problem
is characterized by a single dimensionless parameter which is proportional to
the ratio of the applied force and the temperature of the particle environment.
In such structures entropic effects may play a dominant role. Under certain
conditions the two dimensional dynamics can be approximated by an effective one
dimensional motion of the particle in the longitudinal direction. The Langevin
equation describing this reduced, one dimensional process is of the type of the
Fick-Jacobs equation. It contains an entropic potential determined by the
varying extension of the eliminated channel direction, and a correction to the
diffusion constant that introduces a space dependent diffusion. Different forms
of this correction term have been suggested before, which we here compare for a
particular class of models. We analyze the regime of validity of the
Fick-Jacobs equation, both by means of analytical estimates and the comparisons
with numerical results for the full two dimensional stochastic dynamics. For
the nonlinear mobility we find a temperature dependence which is opposite to
that known for particle transport in periodic potentials. The influence of
entropic effects is discussed for both, the nonlinear mobility and the
effective diffusion constant.


title:
Exact Exponent of Remainder Term of Gelfond's Digit Theorem in Binary
  Case

abstract:
  We give a simple formula for the exact exponent in the remainder term of the
main Gelfond's digit theorem in the binary case.


title:
An additive and operational entanglement measure: conditional
  entanglement of mutual information

abstract:
  Based on the monogamy of entanglement, we develop the technique of quantum
conditioning to build an {\it additive} entanglement measure: the conditional
entanglement of mutual information. Its {\it operational} meaning is elaborated
to be the minimal net "flow of qubits" in the process of partial state merging.
The result and conclusion can also be generalized to multipartite entanglement
cases.


title: Some spectral equivalences between Schrodinger operators

abstract:
  Spectral equivalences of the quasi-exactly solvable sectors of two classes of
Schrodinger operators are established, using Gaudin-type Bethe ansatz
equations. In some instances the results can be extended leading to full
isospectrality. In this manner we obtain equivalences between PT-symmetric
problems and Hermitian problems. We also find equivalences between some classes
of Hermitian operators.


title: The Berry-Tabor conjecture for spin chains of Haldane-Shastry type

abstract:
  According to a long-standing conjecture of Berry and Tabor, the distribution
of the spacings between consecutive levels of a "generic'' integrable model
should follow Poisson's law. In contrast, the spacings distribution of chaotic
systems typically follows Wigner's law. An important exception to the
Berry-Tabor conjecture is the integrable spin chain with long-range
interactions introduced by Haldane and Shastry in 1988, whose spacings
distribution is neither Poissonian nor of Wigner's type. In this letter we
argue that the cumulative spacings distribution of this chain should follow the
"square root of a logarithm'' law recently proposed by us as a characteristic
feature of all spin chains of Haldane-Shastry type. We also show in detail that
the latter law is valid for the rational counterpart of the Haldane-Shastry
chain introduced by Polychronakos.

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


title:
Hidden variable models for entanglements can or cannot have a local
  component?

abstract:
  A recent article of Colbeck and Renner tackled the problem whether
entanglements may be explained by combined models of local and non-local hidden
variables. To the difference from previous works they considered models in
which each pair of entangled particles behaves in the same way, and the
particles in the pair are equivalent, i.e. each of them produces its response
to a measurement according to both local and non-local hidden variables. Their
article aimed at proving that the local hidden variable component in such
models has no effect on the measurement results, i.e. only the non-local
variables are relevant. However, their proof deals with a very restrictive case
and assumes questionable constraints on the hidden variables. The present text
studies the Colbeck and Renner class of models on a less restrictive case and
under no constraints on the hidden variables. It is shown again that the local
component cannot have any influence on the results. However, the Colbeck and
Renner class of models is not the only one possible. A different class is
described, and it admits local hidden variables by the side of the non-local
influence. This class presents a couple of advantages.


title: Tailoring wave nonlinearity through spatial composites

abstract:
  We propose and demonstrate theoretically a method to achieve and design
optical nonlinear responses through a light-mediated spatial hybridization of
different standard nonlinearities. The mechanism is based on the fact that
optical propagation through a spatial composite of different nonlinear media is
governed by an effective nonlinear response if the spatial scale of the
sequence is much smaller than the light diffraction length. We apply our
general approach to the significant case of centrosymmetric photorefractive
crystal biased by a periodically modulated external voltage to predict strictly
bending-free miniaturized soliton propagation.


title: Disc wind in the HH 30 binary models

abstract:
  Recent interferometric observations of the young stellar object(YSO) HH 30
have revealed a low velocity outflow in the $^{12}$CO J=1-2 molecule line (Pety
et al. 2006). We present here two models of the low velocity disc winds with
the aim of investigating an origin of this molecular outflow. Following Andlada
et al. (2006) we treated HH 30 as a binary system. Two cases have been
considered: i) the orbital period $P$ = 53 yrs and ii) $P \le$ 1 yr.
Calculations showed that in the first case the outflow cone had a spiral-like
structure due to summing the velocities of the orbital motion and the disc
wind. Such a structure contradicts the observations. In the second case, the
outflow cone demonstrates a symmetry relatively to the system axis and agrees
well with the observations.


title: A new approach to the quantized electrical conductance

abstract:
  The quanta of electrical conductance is derived for a one-dimensional
electron gas both by making use of the quasi-classical motion of a quantum
fluid and by using arguments related to the uncertainty principle. The result
is extended to a nanowire of finite cross-section area and to electrons in
magnetic field, and the quantization of the electrical conductance is shown. An
additional application is made to the two-dimensional electron gas.


title: Distinct Distances in Graph Drawings

abstract:
  The \emph{distance-number} of a graph $G$ is the minimum number of distinct
edge-lengths over all straight-line drawings of $G$ in the plane. This
definition generalises many well-known concepts in combinatorial geometry. We
consider the distance-number of trees, graphs with no $K^-_4$-minor, complete
bipartite graphs, complete graphs, and cartesian products. Our main results
concern the distance-number of graphs with bounded degree. We prove that
$n$-vertex graphs with bounded maximum degree and bounded treewidth have
distance-number in $\mathcal{O}(\log n)$. To conclude such a logarithmic upper
bound, both the degree and the treewidth need to be bounded. In particular, we
construct graphs with treewidth 2 and polynomial distance-number. Similarly, we
prove that there exist graphs with maximum degree 5 and arbitrarily large
distance-number. Moreover, as $\Delta$ increases the existential lower bound on
the distance-number of $\Delta$-regular graphs tends to $\Omega(n^{0.864138})$.


title: Lack of monotonicity in spin glass correlation functions

abstract:
  We study the response of a spin glass system with respect to the rescaling of
its interaction random variables and investigate numerically the behaviour of
the correlation functions with respect to the volume. While for a ferromagnet
the local energy correlation functions increase monotonically with the scale
and, by consequence, with respect to the volume of the system we find that in a
general spin glass model those monotonicities are violated.


title:
Violation of the Equipartition Theorem for Thermally Insulated Clusters
  of Atoms with Different Masses

abstract:
  An expression is derived for calculating microcanonical-ensemble averages of
the kinetic energies of atoms of different types in clusters isolated from the
environment. This expression is a natural generalization of the solution to the
problem of hard spheres with different masses to a system with a many-particle
interatomic interaction potential. The dynamics of a C8H8 cubane is simulated
numerically. The data on the numerical simulation confirm the validity of the
results obtained.


title:
Isotropization in the approach to big rip singularities for Cardassian
  models

abstract:
  Cardassian models are an alternative to general relativity which have been
proposed as an approach to explaining accelerated cosmic expansion while
avoiding directly introducing dark energy. They are generally formulated only
in the homogeneous and isotropic case. In this paper an extension of the usual
formulation to general spatially homogeneous geometries is given. A
characteristic feature of many classes of Cardassian models is the occurrence
of big rip singularities where the scale factor tends to infinity after a
finite time. It is shown that big rip singularities are also widespread in more
general homogeneous cases. It is also shown that there is isotropization in the
approach to a big rip singularity which bears a strong resemblance to the
late-time isotropization observed in cosmological spacetimes which accelerate
forever in the future.


title:
Negative modes of Schwarzschild black hole in Einstein-Gauss-Bonnet
  Theory

abstract:
  We study non conformal negative modes of Schwarzschild black holes in the
five dimensional Einstein-Gauss-Bonnet gravity theory with a zero or negative
cosmological constant, in the context of the semiclassical quantum gravity
formulated by the path integral. We find an unique negative mode when the black
hole has a negative heat capacity which is the same in Einstein theory. On the
other hand, we still find negative modes inside a parameter region where a
small black hole has a positive heat capacity. The number is one/two for the
case of zero/negative cosmological constant respectively. In the rest of the
parameter region where the heat capacity is positive, we find no negative
modes. We discuss the possible physical understanding of having one or two
negative modes.


title: Interpretation of K+K0bar pair production in pp collisions

abstract:
  A combined analysis of the published data on the pp -> dK+K0bar reaction at
excess energies of 47.4 MeV and 104.7 MeV is presented. Evidence is found for
both the production of the a0+(980)scalar resonance and for a strong K0bar:d
final state interaction.


title: Slicing surfaces and Fourier restriction conjecture

abstract:
  We deal with the restriction phenomenon for the Fourier transform. We prove
that each of the restriction conjectures for the sphere, the paraboloid, the
elliptic hyperboloid in $\mathbb{R}^n$ implies that for the cone in
$\mathbb{R}^{n+1}$. We also prove a new restriction estimate for any surface in
$\mathbb{R}^3$ locally isometric to the plane and of finite type.


title:
AC magnetization transport and power absorption in non-itinerant spin
  chains

abstract:
  We investigate the ac transport of magnetization in non-itinerant quantum
systems such as spin chains described by the XXZ Hamiltonian. Using linear
response theory, we calculate the ac magnetization current and the power
absorption of such magnetic systems. Remarkably, the difference in the exchange
interaction of the spin chain itself and the bulk magnets (i.e. the
magnetization reservoirs), to which the spin chain is coupled, strongly
influences the absorbed power of the system. This feature can be used in future
spintronic devices to control power dissipation. Our analysis allows to make
quantitative predictions about the power absorption and we show that magnetic
systems are superior to their electronic counter parts.


title: Subdwarf O Stars from SDSS and SPY

abstract:
  We present the results of quantitative spectral analysis of sdOs from the
SDSS database. Fitting the Balmer, HeI and HeII lines to non-LTE model spectra,
we derived their effective temperatures, surface gravities and helium
abundances. We find the helium-enriched sdO stars to rally in a small intervall
of Teff = 40,000K to 50,000K and log(g) = 5.5 to 6.0. We conclude, that the sdB
stars are linked with the helium-deficient sdO stars, i.e. the sdBs are
predecessors for the helium-deficient sdOs. To explain the helium-enriched sdO
stars in their entirety, we regard two scenarios as most promising: The merging
of two helium-core white dwarfs and the late hot flashers.


title: An original constraint on the Hubble constant: h>0.74

abstract:
  The Hubble parameter H0 still not very well measured. Although the Hubble Key
Project, Chandra and WMAP gave good estimates, the uncertainties remain quite
large. In this brief report, we suggest an original and independent method to
derive a lower limit on H0 using the absorption of very high energy gamma-rays
by the cosmic infrared background. With conservative hypothesis, we obtain
H0>74 km/s/Mpc at the 68% confidence level, which favors the upper end of the
intervals allowed by dedicated experiments.


title:
Three Dimensional Magnetohydrodynamical Simulations of Core Collapse
  Supernova

abstract:
  We show three-dimensional magnetohydrodynamical simulations of core collapse
supernova in which the progenitor has magnetic fields inclined to the rotation
axis. The simulations employed a simple empirical equation of state in which
the pressure of degenerate gas is approximated by piecewise polytropes for
simplicity. Neither energy loss due to neutrino is taken into account for
simplicity. The simulations start from the stage of dynamical collapse of an
iron core. The dynamical collapse halts at $ t $ = 189 ms by the pressure of
high density gas and a proto-neutron star (PNS) forms. The evolution of PNS was
followed about 40 milli-seconds in typical models. When the initial rotation is
mildly fast and the initial magnetic fields are mildly strong, bipolar jets are
launched from an upper atmosphere ($ r \sim 60 {\rm km} $) of the PNS. The jets
are accelerated to $ \sim 3 \times 10 ^4 $ km s$^{-1}$, which is comparable to
the escape velocity at the foot point. The jets are parallel to the initial
rotation axis. Before the launch of the jets, magnetic fields are twisted by
rotation of the PNS. The twisted magnetic fields form torus-shape multi-layers
in which the azimuthal component changes alternately. The formation of magnetic
multi-layers is due to the initial condition in which the magnetic fields are
inclined with respect to the rotation axis. The energy of the jet depends only
weakly on the initial magnetic field assumed. When the initial magnetic fields
are weaker, the time lag is longer between the PNS formation and jet ejection.
It is also shown that the time lag is related to the Alfv\'en transit time.
Although the nearly spherical prompt shock propagates outward in our
simulations, it is ...


title: Some results on non-self-adjoint operators, a survey

abstract:
  This text is a survey of recent results obtained by the author and
collaborators on different problems for non-self-adjoint operators. The topics
are: Kramers-Fokker-Planck type operators, spectral asymptotics in two
dimensions and Weyl asymptotics for the eigenvalues of non-self-adjoint
operators with small random perturbations. In the introduction we also review
the notion of pseudo-spectrum and its relation to non-self-adjoint spectral
problems.


title:
Dilepton production in heavy-ion collisions with in-medium spectral
  functions of vector mesons

abstract:
  The in-medium spectral functions of $\rho$ and $\omega$ mesons and the
broadening of the nucleon resonances at finite baryon density are calculated
self-consistently by combining a resonance dominance model for the vector meson
production with an extended vector meson dominance model. The influence of the
in-medium modifications of the vector meson properties on the dilepton spectrum
in heavy-ion collisions is investigated. The dilepton spectrum is generated for
the C+C reaction at 2.0$A$ GeV and compared with recent HADES Collaboration
data. The collision dynamics is then described by the T\"ubingen relativistic
quantum molecular dynamics transport model. We find that an iterative
calculation of the vector meson spectral functions that takes into account the
broadening of the nucleon resonances due to their increased in-medium decay
branchings is convergent and provides a reasonable description of the
experimental data in the mass region $0.45\leq M \leq 0.75$ GeV. On the other
side, the theoretical calculations slightly underestimate the region $m_\pi\leq
M \leq 0.4$ GeV. Popular in-medium scenarios such as a schematic collisional
broadening and dropping vector mesons masses are discussed as well.


title: Penetrable Square-Well fluids: Exact results in one dimension

abstract:
  We introduce a model of attractive penetrable spheres by adding a short range
attractive square well outside a penetrable core, and we provide a detailed
analysis of structural and thermodynamical properties in one dimension using
the exact impenetrable counterpart as a starting point. The model is expected
to describe star polymers in regimes of good and moderate solvent under dilute
conditions. We derive the exact coefficients of a low density expansion up to
second order for the radial distribution function and up to fourth order in the
virial expansion. These exact results are used as a benchmark to test the
reliability of approximate theories (Percus-Yevick and hypernetted chain).
Notwithstanding the lack of an exact solution for arbitrary densities, our
results are expected to be rather precise within a wide range of temperatures
and densities. A detailed analysis of some limiting cases is carried out. In
particular we provide a complete solution of the sticky penetrable-sphere model
in one dimension up to the same order in density. The issue of Ruelle's
thermodynamics stability is analyzed and the region of a well defined
thermodynamic limit is identified.


title: Dynamical heterogeneity in a glass forming ideal gas

abstract:
  We conduct a numerical study of the dynamical behavior of a system of
three-dimensional crosses, particles that consist of three mutually
perpendicular line segments rigidly joined at their midpoints. In an earlier
study [W. van Ketel et al., Phys. Rev. Lett. 94, 135703 (2005)] we showed that
this model has the structural properties of an ideal gas, yet the dynamical
properties of a strong glass former. In the present paper we report an
extensive study of the dynamical heterogeneities that appear in this system in
the regime where glassy behavior sets in. On the one hand, we find that the
propensity of a particle to diffuse is determined by the structure of its local
environment. The local density around mobile particles is significantly less
than the average density, but there is little clustering of mobile particles,
and the clusters observed tend to be small. On the other hand, dynamical
susceptibility results indicate that a large dynamical length scale develops
even at moderate densities. This suggests that propensity and other mobility
measures are an incomplete measure of dynamical length scales in this system.


title:
Quantum phase transition and critical fluctuations of an attractive Bose
  gas in a double well potential

abstract:
  We consider a Bose gas with an attractive interaction in a symmetric double
well potential. In the Hartree approximation, the ground state solution
spontaneously breaks the symmetry of the trapping potential above certain value
of the interaction strength. We demonstrate how the Landau-Ginzburg scheme of
the second order phase transition emerges from the quantum model and show its
link to the spontaneous symmetry breaking mentioned above. We identify the
order parameter, the critical point and analyze quantum fluctuations around it.


title: Investigation of Electroweak Production of the Top Quark at the LHC

abstract:
  This thesis presents a study of the prospects of measuring electroweak
production of the top quark at the LHC. The study of the top quark is a highly
topical subject as we expect significant numbers of top quarks at the LHC which
will enable us to conduct precision measurements of the properties of the top.
The t-channel "single top" is a relatively rare mode of top production but with
it we can probe the spin structure of the Wtb vertex in the weak interaction at
an unprecedented energy scale through the measurement of the top polarisation.
  Analysis strategies and computing tools were developed and tested
extensively. The study was performed using the signal and background events
modelled with Monte Carlo generators, many of which have been newly developed
for the LHC analyses. Full and fast simulation of the ATLAS detector was
performed to obtain realistic estimates of the sensitivity of the measurements.
A new fully fledged analysis framework, "EventView" was developed for the ATLAS
collaboration to process these data at the first level of analysis.
Parameterised vertex tagging was developed to estimate the level of background
for this analysis and a maximum likelihood fit was used for the precise
extraction of the top polarisation.
  In the high energy hadronic environment at the LHC, the estimation of
possible systematic errors, both experimental and theoretical, needs to be
carefully considered. Important elements of the systematic errors were
investigated and the main contributions were evaluated.


title: U(1) Problem Revisited

abstract:
  In the anomaly equation for the singlet axial current the chiral limit of the
quark mass term does not vanish but comprises contribution from fermion zero
modes whose integral exactly cancels the topological charge arising from the
Adler-Bell-Jackiw anomaly. This signals chiral symmetry and opens a window for
restoring the status of Goldstone boson for the singlet $\eta^\prime$ without
having to invoke the large $N_c$ limit in the underlying QCD. We construct the
anomaly term in the effective action that incorporates the chiral symmetry
property and yet accounts for the excess mass of $\eta^\prime$ only when chiral
symmetry is broken explicitly by the quark masses. The anomaly term in the
present scenario thus plays the role of a catalytic agent that enhances the
mass of $\eta^\prime$ so that the singlet axial current obeys the popular PCAC
condition.


title: Effective Hamiltonian for piecewise flat potentials and masses

abstract:
  We consider a class of Hermitian Hamiltonians with position-dependent mass
$H=((m^alpha)p(m^beta)p(m^alpha))/2+\V$ with $2(alpha)+\beta=-1$. We apply
these Hamiltonians to different piecewise flat potentials and masses (step,
barrier, well and multibarrier). To raise the ordering ambiguity we impose that
the transmission coefficient tends to the unity as the energy increases
indefinitely. We arrive at the conclusion that the form
$H_flat=(m^(-1/4)pm^(-1/2)pm^(-1/4))/2+\V$ of the effective Hamiltonian is the
most adequate to describe such flat potentials and masses systems.


title: Phonons in magnon superfluid and symmetry breaking field

abstract:
  Recent experiments [1],[2] which measured the spectrum of the Goldstone
collective mode of coherently precessing state in 3He-B are discussed using the
presentation of the coherent spin precession in terms of the Bose-Einstein
condensation of magnons. The mass in the spectrum of the Goldstone boson --
phonon in the superfluid magnon liquid -- is induced by the symmetry breaking
field, which is played by the RF magnetic field


title:
Ultralong quantum optical storage using reversible inhomogeneous spin
  ensembles with an optical locking method

abstract:
  A novel method of multi-bit quantum optical data storage is presented, where
the storage time can be lengthened far beyond the spin phase-decay time in a
reversible spin inhomogeneous system excited by consecutive resonant Raman
optical data pulses. The ultralong storage time is obtained by an optical
population locking mechanism of modified rephasing process. This gives
potentials to quantum repeaters utilizing quantum memories for long distance
quantum communications, in which ultralong storage time plays a major role.


title: Sum rules for higher twist sl(2)operators in N=4 SYM

abstract:
  The spectrum of anomalous dimensions of twist sl(2) operators in N=4 SYM has
an intriguing feature in low twist 2 or 3. The anomalous dimension of the
lowest state, dual a folded string on AdS_5 X S^5, can be computed by Bethe
Ansatz at 3, 4 loops respectively as a simple closed function of the Lorentz
spin. This feature is apparently lost at higher twist. We propose sum rules for
the excited anomalous dimensions where closed expressions can still be
provided, even at higher twist. We present several explicit three loop
examples. Many structural regularities can be observed leading to closed
expressions which depend parametrically both on the spin and the twist. They
allow to compute the subleading term in the logarithmic large spin expansion of
the sum rules as a compact simple function of the twist, in analogy with the
recent results by Freyhult, Rej and Staudacher in arXiv:0712.2743 [hep-th].


title:
The Alpha Centauri Binary System: Atmospheric Parameters and Element
  Abundances

abstract:
  The alpha Centauri binary system, owing to its duplicity, proximity and
brightness, and its components' likeness to the Sun, is a fundamental
calibrating object for the theory of stellar structure and evolution and the
determination of stellar atmospheric parameters. This role, however, is
hindered by a considerable disagreement in the published analyses of its
atmospheric parameters and abundances. We report a new spectroscopic analysis
of both components of the alpha Centauri binary system and compare published
analyses of the system. The analysis is differential with respect to the Sun,
based on high-quality spectra, and employed spectroscopic and photometric
methods to obtain as many independent Teff determinations as possible. The
atmospheric parameters are also checked for consistency against the results of
the dynamical analysis and the positions of the components in a theoretical HR
diagram. We discuss possible origins of discrepancies, concluding that the
presence of NLTE effects is a probable candidate, but we note that there is as
yet no consensus on the existence and cause of an offset between the
spectroscopic and photometric Teff scales of cool dwarfs. The spectroscopic
surface gravities also agree with those derived from directly measured masses
and radii. The abundance pattern can be deemed normal in the context of recent
data on metal-rich stars. The position of alpha Cen A in an up-to-date
theoretical evolutionary diagrams yields a good match of the evolutionary mass
and age with those from the dynamical solution and seismology.


title:
Size dependence of the bulk and surface phonon modes of gallium arsenide
  nanowires as measured by Raman Spectroscopy

abstract:
  Gallium arsenide nanowires were synthesized by gallium-assisted molecular
beam epitaxy. By varying the growth time, nanowires with diameters ranging from
30 to 160 nm were obtained. Raman spectra of the nanowires ensembles were
measured. The small line width of the optical phonon modes agree with an
excellent crystalline quality. A surface phonon mode was also revealed, as a
shoulder at lower frequencies of the longitudinal optical mode. In agreement
with the theory, the surface mode shifts to lower wave numbers when the
diameter of the nanowires is decreased or the environment dielectric constant
increased.


title:
Radiative decays of pseudoscalar (P) and vector (V) mesons and the
  process e^+e^- \to \eta' \rho

abstract:
  Radiative decays of pseudoscalar and vector mesons are calculated in the
framework of the chiral Nambu-Jona-Lasinio (NJL) model. We use the amplitude
for triangle quark loops of anomalous type. In evaluating these loop integrals
we use two methods. In the first one, we neglect the dependence of external
momenta by reproducing the Wess-Zumino-Witten terms of effective chiral meson
Lagrangian. In the second method, we take into account the momentum dependence
of loop integrals omitting their imaginary part. This makes it possible to
allow for quark confinement. As applied both the methods is in qualitative
agreement with each other and with experimental data. The second method allows
us to describe the electron-positron annihilation with production of $\eta'$
and $\rho$ mesons in the center of mass energy range from 1.6 to 3.5$\GeV$. The
comparison with the recent experimental data is presented.


title:
Maximum pseudolikelihood estimator for exponential family models of
  marked Gibbs point processes

abstract:
  This paper is devoted to the estimation of a vector $\bm {\theta}$
parametrizing an energy function of a Gibbs point process, via the maximum
pseudolikelihood method. Strong consistency and asymptotic normality results of
this estimator depending on a single realization are presented. In the
framework of exponential family models, sufficient conditions are expressed in
terms of the local energy function and are verified on a wide variety of
examples.


title: On the Collatz Problem

abstract:
  Taking a new approach towards analyzing the Collatz Problem, or, 3x+1
conjecture. Introducing some new functions, the Collatz-2 and Collatz-3
sequences, as well as deducing results related to Collatz-2 and Collatz-3
sequences.


title: Emergence of exponentially small reflected waves

abstract:
  We study the time-dependent scattering of a quantum mechanical wave packet at
a barrier for energies larger than the barrier height, in the semi-classical
regime. More precisely, we are interested in the leading order of the
exponentially small scattered part of the wave packet in the semiclassical
parameter when the energy density of the incident wave is sharply peaked around
some value. We prove that this reflected part has, to leading order, a Gaussian
shape centered on the classical trajectory for all times soon after its birth
time. We give explicit formulas and rigorous error bounds for the reflected
wave for all of these times.


title:
Amplitude of Coulomb scattering for charged scalar field in de Sitter
  spacetime

abstract:
  The scattering of a charged scalar field on Coulomb potential is studied
using solutions of the Klein-Gordon equation which have a definite momentum.
One obtains that in contrast with what happens on Minkowski case the modulus of
momentum is not conserved in the scattering process on de Sitter space.


title: Direct High-Power Laser Acceleration of Ions for Medical Applications

abstract:
  Theoretical investigations show that linearly and radially polarized
multiterawatt and petawatt laser beams, focused to subwavelength waist radii,
can directly accelerate protons and carbon nuclei, over micron-size distances,
to the energies required for hadron cancer therapy. Ions accelerated by
radially polarized lasers have generally a more favorable energy spread than
those accelerated by linearly polarized lasers of the same intensity.


title:
Detection methods of binary stars with low- and intermediate-mass
  components

abstract:
  This paper reviews methods which can be used to detect binaries involving
low- and intermediate-mass stars, with special emphasis on evolved systems.
Besides the traditional methods involving radial-velocity or photometric
monitoring, the paper discusses as well less known methods involving astrometry
or maser (non-)detection. An extensive list of internet resources (mostly
catalogues/databases of orbits and individual measurements) for the study of
binary stars is provided at the end of the paper.


title: F(R) gravity equation of state

abstract:
  The ${\bf f}(R)$ gravity field equations are derived as an equation of state
of local space-time thermodynamics. Jacobson's arguments are non-trivially
extended, by means of a more general definition of local entropy, for which
Wald's definition of dynamic black hole entropy is used, as well as the concept
of an effective Newton constant for graviton exchange, recently appeared in the
literature.

categories: hep-th astro-ph gr-qc math-ph math.MP quant-ph


title: The f_LT Response Function of D(e,e'p)n at Q^2=0.33(GeV/c)^2

abstract:
  The interference response function f_LT (R_LT) of the D(e,e'p)n reaction has
been determined at squared four-momentum transfer Q^2 = 0.33 (GeV/c)^2 and for
missing momenta up to p_miss= 0.29 (GeV/c). The results have been compared to
calculations that reproduce f_LT quite well but overestimate the cross sections
by 10 - 20% for missing momenta between 0.1 (GeV/c) and 0.2 (GeV/c) .


title:
Coherent backscattering of Bose-Einstein condensates in two-dimensional
  disorder potentials

abstract:
  We study quantum transport of an interacting Bose-Einstein condensate in a
two-dimensional disorder potential. In the limit of vanishing atom-atom
interaction, a sharp cone in the angle-resolved density of the scattered matter
wave is observed, arising from constructive interference between amplitudes
propagating along reversed scattering paths. Weak interaction transforms this
coherent backscattering peak into a pronounced dip, indicating destructive
instead of constructive interference. We reproduce this result, obtained from
the numerical integration of the Gross-Pitaevskii equation, by a diagrammatic
theory of weak localization in presence of a nonlinearity.


title:
Genericity of nondegenerate critical points and Morse geodesic
  functionals

abstract:
  We consider a family of variational problems on a Hilbert manifold
parameterized by an open subset of a Banach manifold, and we discuss the
genericity of the nondegeneracy condition for the critical points. Based on an
idea of B. White, we prove an abstract genericity result that employs the
infinite dimensional Sard--Smale theorem. Applications are given by proving the
genericity of metrics without degenerate geodesics between fixed endpoints in
general (non compact) semi-Riemannian manifolds, in orthogonally split
semi-Riemannian manifolds and in globally hyperbolic Lorentzian manifolds. We
discuss the genericity property also in stationary Lorentzian manifolds.


title: Superconductivity at 41.0 K in the F-doped LaFeAsO1-xFx

abstract:
  Here we report the superconductivity in the LaFeAsO1-xFx system prepared by
high pressure synthesis. The highest onset superconducting transition
temperature (Tc) in this La-based system is 41.0 K with the nominal composition
of LaFeAsO1-xFx (x = 0.6), which is higher than that reported previously by
ambient pressure synthesis. The increase of Tc can be attributed to the further
shrinkage of crystal lattice that causes the stronger chemical pressure on the
Fe-As plane, which is induced by the increased F-doping level under high
pressure synthesis.


title: Quantum Geometry and Quantum Gravity

abstract:
  The purpose of this contribution is to give an introduction to quantum
geometry and loop quantum gravity for a wide audience of both physicists and
mathematicians. From a physical point of view the emphasis will be on
conceptual issues concerning the relationship of the formalism with other more
traditional approaches inspired in the treatment of the fundamental
interactions in the standard model. Mathematically I will pay special attention
to functional analytic issues, the construction of the relevant Hilbert spaces
and the definition and properties of geometric operators: areas and volumes.


title: Superconductivity at 53.5 K in GdFeAsO1-delta

abstract:
  Here we report the fabrication and superconductivity of the iron-based
arsenic-oxide GdFeAsO1-delta compound with oxygen-deficiency, which has an
onset resistivity transition temperature at 53.5 K. This material has a same
crystal structure as the newly discovered high-Tc ReFeAsO1-delta family (Re =
rare earth metal) and a further reduced crystal lattice, while the Tc starts to
decrease compared with the SmFeAsO1-delta system.


title: Introduction to Quantum Mechanics

abstract:
  The purpose of this contribution is to give a very brief introduction to
Quantum Mechanics for an audience of mathematicians. I will follow Segal's
approach to Quantum Mechanics paying special attention to algebraic issues. The
usual representation of Quantum Mechanics on Hilbert spaces is also discussed.


title: Homogeneous Metrics with nonnegative curvature

abstract:
  Given compact Lie groups H\subset G, we study the space of G-invariant
metrics on G/H with nonnegative sectional curvature. For an intermediate
subgroup K between H and G, we derive conditions under which enlarging the Lie
algebra of K maintains nonnegative curvature on G/H. Such an enlarging is
possible if (K,H) is a symmetric pair, which yields many new examples of
nonnegatively curved homogeneous metrics. We provide other examples of spaces
G/H with unexpectedly large families of nonnegatively curved homogeneous
metrics.


title:
Constraints from F and D supersymmetry breaking in general supergravity
  theories

abstract:
  We study the conditions under which a generic supergravity model involving
chiral and vector multiplets can admit vacua with spontaneously broken
supersymmetry and realistic cosmological constant. We find that the existence
of such viable vacua implies some constraints involving the curvature tensor of
the scalar geometry and the charge and mass matrices of the vector fields, and
also that the vector of F and D auxiliary fields defining the Goldstino
direction is constrained to lie within a certain domain. We illustrate the
relevance of these results through some examples and also discuss the
implications of our general results on the dynamics of moduli fields in string
models. This contribution is based on [1,2,3].


title: Hierarchical Markovian algorithm in QCD evolution

abstract:
  A general formalism was introduced for reorganization of QCD evolution
equations and derivation of hierarchical solution to DGLAP equation. The
hierarchical solution separates two types of parton emissions: the flavour
changing emissions and the diagonal ones (bremsstrahlung). It has been shown
that both of the achieved processes are of the Markovian type, what gives a
nice possibility of Monte Carlo implementation. Hierarchical algorithm has been
implemented and crosschecked with standard Markovian algorithm implemented in
program EvolFMC.


title:
Ion acoustic waves in the plasma with the power-law q-distribution in
  nonextensive statistics

abstract:
  We investigate the dispersion relation and Landau damping of ion acoustic
waves in the collisionless magnetic-field-free plasma if it is described by the
nonextensive q-distributions of Tsallis statistics. We show that the increased
numbers of superthermal particles and low velocity particles can explain the
strengthened and weakened modes of Landau damping, respectively, with the
q-distribution. When the ion temperature is equal to the electron temperature,
the weakly damped waves are found to be the distributions with small values of
q.


title:
Stability analysis of the classical ideal gas in nonextensive statistics
  and the negative specific heat

abstract:
  We present a stability analysis of the classical ideal gas in a new theory of
nonextensive statistics and use the theory to understand the phenomena of
negative specific heat in some self-gravitating systems. The stability analysis
is made on the basis of the second variation of Tsallis entropy. It is shown
that the system is thermodynamically unstable if the nonextensive parameter is
q>5/3, which is exactly equivalent to the condition of appearance of the
negative specific heat.


title: Synchronization of oscillators coupled through an environment

abstract:
  We study synchronization of oscillators that are indirectly coupled through
their interaction with an environment. We give criteria for the stability or
instability of a synchronized oscillation. Using these criteria we investigate
synchronization of systems of oscillators which are weakly coupled, in the
sense that the influence of the oscillators on the environment is weak. We
prove that arbitrarily weak coupling will synchronize the oscillators, provided
that this coupling is of the 'right' sign. We illustrate our general results by
applications to a model of coupled GnRH neuron oscillators proposed by Khadra
and Li, and to indirectly weakly-coupled lambda-omega oscillators


title: Energy fluctuations and the ensemble equivalence in Tsallis statistics

abstract:
  We investigate the general property of the energy fluctuation for the
canonical ensemble in Tsallis statistics and the ensemble equivalence. By
taking the ideal gas and the non-interacting harmonic oscillators as examples,
we show that, when the particle number N is large enough, the relative
fluctuation of the energy is proportional to 1/N in the new statistics, instead
of square root of 1/N in Boltzmann-Gibbs statistics. Thus the equivalence
between the microcanonical and the canonical ensemble still holds in Tsallis
statistics.


title:
On search for eV hidden sector photons in Super-Kamiokande and CAST
  experiments

abstract:
  If light hidden sector photons exist, they could be produced through kinetic
mixing with solar photons in the eV energy range. We propose to search for this
hypothetical hidden photon flux with the Super-Kamiokande and/or upgraded CAST
detectors. The proposed experiments are sensitive to mixing strengths as small
as 10^-9 for hidden photon masses in the sub eV region and, in the case of
non-observation, would improve limits recently obtained from photon
regeneration laser experiments in this mass region.


title:
Combinatorial and model-theoretical principles related to regularity of
  ultrafilters and compactness of topological spaces. III

abstract:
  We generalize the results from "P. Lipparini, Productive
$[\lambda,\mu]$-compactness and regular ultrafilters, Topology Proceedings, 21
(1996), 161--171"; in particular the present results apply to singular
cardinals, too.


title: Superconductivity of powder-in-tube LaO0.9F0.1FeAs wires

abstract:
  We demonstrate that Fe sheathed LaO0.9F0.1FeAs wires with Ti as a buffer
layer were successfully fabricated by the powder-in-tube (PIT) method.
Comparing to the common two-step vacuum quartz tube synthesis method, the PIT
method is more convenient and safe for synthesizing the novel iron-based
layered superconductors. Structural analysis by mean of x-ray diffraction shows
that the main phase of LaO0.9F0.1FeAs was obtained by this synthesis method.
The transition temperature of the LaO0.9F0.1FeAs wire is around 25 K. The
micrograph shows a homogeneous microstructure with a grain size of 1-3
micrometers. The results suggest that the PIT process is promising in preparing
high-quality iron-based layered superconductor wires.


title: A class of matrix-valued polynomials generalizing Jacobi Polynomials

abstract:
  A hierarchy of matrix-valued polynomials which generalize the Jacobi
polynomials is found. Defined by a Rodrigues formula, they are also products of
a sequence of differential operators. Each class of polynomials is complete,
satisfies a two-step recurrence relation, integral inter-relations, and
quasi-orthogonality relations.


title: Influence of Z' boson on top quark spin correlations at the LHC

abstract:
  We study top-antitop pair production and top spin correlations in a model
with an electrically neutral massive gauge boson, Z', at the Large Hadron
Collider. In addition to the Standard Model processes, the Z' contributes to
the top-antitop pair production process in the s-channel. Choosing a
kinematical region of top invariant mass around the Z' resonance pole, we find
sizable deviations of the top-antitop pair production cross section and the top
spin correlations from those of the Standard Model.


title:
Localization and advectional spreading of convective currents under
  parametric disorder

abstract:
  We address a problem which is mathematically reminiscent of the one of
Anderson localization, although it is related to a strongly dissipative
dynamics. Specifically, we study thermal convection in a horizontal porous
layer heated from below in the presence of a parametric disorder; physical
parameters of the layer are time-independent and randomly inhomogeneous in one
of the horizontal directions. Under such a frozen parametric disorder,
spatially localized flow patterns appear. We focus our study on their
localization properties and the effect of an imposed advection along the layer
on these properties. Our interpretation of the results of the linear theory is
underpinned by numerical simulation for the nonlinear problem. Weak advection
is found to lead to an upstream delocalization of localized current patterns.
Due to this delocalization, the transition from a set of localized patterns to
an almost everywhere intense "global" flow can be observed under conditions
where the disorder-free system would be not far below the instability
threshold. The results presented are derived for a physical system which is
mathematically described by a modified Kuramoto-Sivashinsky equation and
therefore they are expected to be relevant for a broad variety of dissipative
media where pattern selection occurs.