title:
Violation of Wiedemann-Franz law at the Kondo breakdown quantum critical
  point

abstract:
  We study both the electrical and thermal transport near the heavy-fermion
quantum critical point (QCP), identified with the breakdown of the Kondo effect
as an orbital selective Mott transition. We show that the contribution to the
electrical conductivity comes mainly from conduction electrons while the
thermal conductivity is given by both conduction electrons and localized
fermions (spinons), scattered with dynamical exponent $z = 3$. This scattering
mechanism gives rise to a quasi-linear temperature dependence of the electrical
and thermal resistivity. The characteristic feature of the Kondo breakdown
scenario turns out to be emergence of additional entropy carriers, that is,
spinon excitations. As a result, we find that the Wiedemann-Franz ratio should
be larger than the standard value, a fact which enables to differentiate the
Kondo breakdown scenario from the Hertz-Moriya-Millis framework.


title: Hyperkahler SYZ conjecture and semipositive line bundles

abstract:
  Let $M$ be a compact, holomorphic symplectic Kaehler manifold, and $L$ a
non-trivial line bundle admitting a metric of semi-positive curvature. We show
that some power of $L$ is effective. This result is related to the hyperkaehler
SYZ conjecture, which states that such a manifold admits a holomorphic
Lagrangian fibration, if $L$ is not big.


title:
Period changes in six contact binaries: WZ And, V803 Aql, DF Hya, PY
  Lyr, FZ Ori, and AH Tau

abstract:
  Six contact binaries lacking a period analysis have been chosen to search for
the presence of a third body. The O-C diagrams of these binaries were analyzed
with the least-squares method by using all available times of minima. Ten new
minima times, obtained from our observations, were included in the present
research. The Light-Time Effect was adopted for the first time as the main
cause for the detailed description of the long-term period changes. Third
bodies were found with orbital periods from 49 up to 100 years, and
eccentricities from 0.0 to 0.56 for the selected binaries. In one case (WZ
And), a fourth-body LITE variation was also applied. The mass functions and the
minimal masses of such bodies were also calculated and a possible angular
separation and magnitude differences were discussed for a prospective
interferometric discovery of these bodies.


title:
Giroux correspondence, confoliations, and symplectic structures on S^1 x
  M

abstract:
  Let M be a closed oriented 3-manifold such that S^1 x M admits a symplectic
structure w. The goal of this paper is to show that M is a fiber bundle over
S^1. The basic idea is to use the obvious S^1-action on S^1 x M by rotating the
first factor, and one of the key steps is to show that the S^1-action on S^1 x
M is actually symplectic with respect to a symplectic form cohomologous to w.
We achieve it by crucially using the recent result or its relative version of
Giroux about one-to-one correspondence between open book decompositions of M up
to positive stabilization and co-oriented contact structures on M up to contact
isotopy.


title: AdS/QCD and its Holographic Light-Front Partonic Representation

abstract:
  Starting from the Hamiltonian equation of motion in QCD we find a single
variable light-front equation for QCD which determines the eigenspectrum and
the light-front wavefunctions of hadrons for general spin and orbital angular
momentum. This light-front wave equation is equivalent to the equations of
motion which describe the propagation of spin-$J$ modes on anti-de Sitter (AdS)
space.


title:
An asymptotic theory for randomly forced discrete nonlinear heat
  equations

abstract:
  We study discrete nonlinear parabolic stochastic heat equations of the form,
$u_{n+1}(x)-u_n(x)=(\mathcal {L}u_n)(x)+\sigma(u_n(x))\xi_n(x)$, for $n\in
{\mathbf{Z}}_+$ and $x\in {\mathbf{Z}}^d$, where $\boldsymbol
\xi:=\{\xi_n(x)\}_{n\ge 0,x\in {\mathbf{Z}}^d}$ denotes random forcing and
$\mathcal {L}$ the generator of a random walk on ${\mathbf{Z}}^d$. Under mild
conditions, we prove that the preceding stochastic PDE has a unique solution
that grows at most exponentially in time. And that, under natural conditions,
it is "weakly intermittent." Along the way, we establish a comparison principle
as well as a finite support property.


title: Floer homology for 2-torsion instanton invariants

abstract:
  We construct a variant of Floer homology groups and prove a gluing formula
for a variant of Donaldson invariants. As a corollary, the variant of Donaldson
invariants is non-trivial for connected sums of 4-manifolds which satisfy a
condition for Donaldson invariants. We also show a non-existence result of
compact, spin 4-manifolds with boundary some homology 3-spheres and with
certain intersection forms.


title: Hybrid exotic meson with J^{PC}=1^{-+} in AdS/QCD

abstract:
  We investigate the hybrid exotic meson with $J^{PC}=1^{-+}$ within the
framework of an AdS/QCD model. Introducing a holographic field dual to the
operator for hybrid exotic meson, we obtain the eigen-value equation for its
mass. Fixing all free parameters by QCD observables such as the $\rho$-meson
mass, we predict the masses of the hybrid exotic meson. The results turn out to
be $1476 \mathrm{MeV}$ for the ground state, and $2611 \mathrm{MeV}$ for the
first excited one. Being compared with the existing experimental data for the
$\pi_1(1400)$, which is known to be $m_{\pi_1} = 1351\pm30 \mathrm{MeV}$, the
present result seems to be qualitative in agreement with it. We also predict
the decay constant of $\pi_1$(1400): $F_{\pi_1}= 10.6$ MeV.


title:
Quantum Phase Diagram and Excitations for the One-Dimensional S=1
  Heisenberg Antiferromagnet with Single-Ion Anisotropy

abstract:
  We investigate the zero-temperature phase diagram of the one-dimensional S=1
Heisenberg antiferromagnet with single-ion anisotropy. By employing high-order
series expansions and quantum Monte Carlo simulations we obtain accurate
estimates for the critical points separating different phases in the quantum
phase diagram. Additionally, excitation spectra and gaps are obtained.


title:
Expander graphs based on GRH with an application to elliptic curve
  cryptography

abstract:
  We present a construction of expander graphs obtained from Cayley graphs of
narrow ray class groups, whose eigenvalue bounds follow from the Generalized
Riemann Hypothesis. Our result implies that the Cayley graph of (Z/qZ)* with
respect to small prime generators is an expander. As another application, we
show that the graph of small prime degree isogenies between ordinary elliptic
curves achieves non-negligible eigenvalue separation, and explain the
relationship between the expansion properties of these graphs and the security
of the elliptic curve discrete logarithm problem.


title:
Study of quark distribution amplitudes of 1S and 2S heavy quarkonium
  states

abstract:
  In this paper, the quark distribution amplitudes of 1S and 2S heavy
quarkonium states are studied in terms of Gaussian-type wave functions. The
transverse momenta $p_\perp$ integrals of the formulae for the decay constant
are performed analytically. Then the quark distribution amplitudes are
obtained. In addition, the $\xi$-moments are also calculated. After fixing the
relevant parameters appearing in the quark distribution amplitude, the curves
of the quark distribution amplitude for 1S and 2S heavy quarkonium states are
plotted. Finally, the numerical results of this approach are compared with the
other theoretical predictions.


title: Master Stability Functions for Coupled Near-Identical Dynamical Systems

abstract:
  We derive a master stability function (MSF) for synchronization in networks
of coupled dynamical systems with small but arbitrary parametric variations.
Analogous to the MSF for identical systems, our generalized MSF simultaneously
solves the linear stability problem for near-synchronous states (NSS) for all
possible connectivity structures. We also derive a general sufficient condition
for stable near-synchronization and show that the synchronization error scales
linearly with the magnitude of parameter variations.Our analysis underlines
significant roles played by the Laplacian eigenvectors in the study of network
synchronization of near-identical systems.


title: Springer representations on the Khovanov Springer varieties

abstract:
  Springer varieties are studied because their cohomology carries a natural
action of the symmetric group $S_n$ and their top-dimensional cohomology is
irreducible. In his work on tangle invariants, Khovanov constructed a family of
Springer varieties $X_n$ as subvarieties of the product of spheres $(S^2)^n$.
We show that if $X_n$ is embedded antipodally in $(S^2)^n$ then the natural
$S_n$-action on $(S^2)^n$ induces an $S_n$-representation on the image of
$H_*(X_n)$. This representation is the Springer representation. Our
construction admits an elementary (and geometrically natural) combinatorial
description, which we use to prove that the Springer representation on
$H_*(X_n)$ is irreducible in each degree. We explicitly identify the
Kazhdan-Lusztig basis for the irreducible representation of $S_n$ corresponding
to the partition $(n/2,n/2)$.


title:
Effects of Rotation on Standing Accretion Shock Instability in Nonlinear
  Phase for Core-Collapse Supernovae

abstract:
  We studied the effects of rotation on standing accretion shock instability
(SASI) by performing three-dimensional hydrodynamics simulations. Taking into
account a realistic equation of state and neutrino heating/cooling, we prepared
a spherically symmmetric and steady accretion flow through a standing shock
wave onto a proto-neutron star (PNS). When the SASI entered the nonlinear
phase, we imposed uniform rotation on the flow advecting from the outer
boundary of the iron core, whose specific angular momentum was assumed to agree
with recent stellar evolution models. Using spherical harmonics in space and
Fourier decompositions in time, we performed mode analysis of the nonspherical
deformed shock wave to observe rotational effects on the SASI in the nonlinear
phase. We found that rotation imposed on the axisymmetric SASI did not make any
spiral modes and hardly affected sloshing modes, except for steady l=2, m=0
modes. In contrast, rotation imposed on the non-axisymmetric flow increased the
amplitude of spiral modes so that some spiral flows accreting on the PNS were
more clearly formed inside the shock wave than without rotation. The amplitudes
of spiral modes increased significantly with rotation in the progressive
direction.


title: On the vanishing of negative K-groups

abstract:
  Let k be an infinite perfect field of positive characteristic p and assume
that strong resolution of singularities holds over k. We prove that, if X is a
d-dimensional noetherian scheme whose underlying reduced scheme is essentially
of finite type over the field k, then the negative K-group K_q(X) vanishes for
every q < -d. This partially affirms a conjecture of Weibel.


title: Visualization of flow over a golf ball at Re = 110,000

abstract:
  The drag on a golf ball can be reduced by dimpling the surface. There have
been few studies, primarily experimental, that provide quantitative information
on the details of the drag reduction mechanisms. To illuminate the underlying
mechanisms, Direct Numerical Simulation (DNS) is applied to the flow around a
golf ball using an immersed boundary method. Computations are performed using
up to 500 processors on a range of mesh resolutions from 61 million points to
1.2 billion points. Results are presented from simulations performed at a
Reynolds number of Re = $1.1\times 10^5$ using a grid of 1.2 billion points.
This video shows the development of instabilities in the near-surface flow, as
well as the delay of complete separation due to the development of local shear
layers that lead to local separation and reattachment within individual
dimples.


title:
Mahlburg's work on Crank Functions returns to Ramanujan's work and
  inspiration

abstract:
  Mahlburg (2005) brilliantly showed the importance of crank functions in
partition congruences that were originally guessed by Dyson (1944). Ramanujan's
partition functions are the centre of these works. Not only for the theory on
cranks, but for many other researchers' in India Ramanujan's work inspired for
their career in mathematics. This is an undergraduate expository article.


title:
The Dynamic Behavior of Quantum Statistical Entropy in 5D Ricci-flat
  Black String with Thin-layer Approach

abstract:
  In this paper, the statistical-mechanical entropies of 5D Ricci-flat black
string is calculated through the wave modes of the quantum field with improved
thin-layer brick-wall method. The modes along the fifth dimension are
semi-classically quantized by Randall-Sundrum mass relationship. We use the
two-dimensional area to describe this black string's entropy which, in the
small-mass approximation, is a linear sum of the area of the black hole horizon
and the cosmological horizon. The proportionality coefficients of entropy are
discretized with quantized extra dimensional modes. It should be noted that the
small-mass approximation used in our calculation is naturally justified by the
assumption that the two branes are located far apart.


title:
Effect of gas flow on electronic transport in a DNA-decorated carbon
  nanotube

abstract:
  We calculate the two-time current correlation function using the experimental
data of the current-time characteristics of the Gas-DNA-decorated carbon
nanotube field effect transistor. The pattern of the correlation function is a
measure of the sensitivity and selectivity of the sensors and suggest that
these gas flow sensors may also be used as DNA sequence detectors. The system
is modelled by a one-dimensional tight-binding Hamiltonian and we present
analytical calculations of quantum electronic transport for the system using
the time-dependent nonequilibrium Green's function formalism and the adiabatic
expansion. The zeroth and first order contributions to the current
$I^{(0)}(\bar{t})$ and $I^{(1)}(\bar{t})$ are calculated, where $I^{(0)}
(\bar{t})$ is the Landauer formula. The formula for the time-dependent current
is then used to compare the theoretical results with the experiment.


title:
A metamaterial frequency-selective super-absorber that has absorbing
  cross section significantly bigger than the geometric cross section

abstract:
  Using the idea of transformation optics, we propose a metamaterial device
that serves as a frequency-selective super-absorber, which consists of an
absorbing core material coated with a shell of isotropic double negative
metamaterial. For a fixed volume, the absorption cross section of the
super-absorber can be made arbitrarily large at one frequency. The double
negative shell serves to amplify the evanescent tail of the high order incident
cylindrical waves, which induces strong scattering and absorption. Our
conclusion is supported by both analytical Mie theory and numerical finite
element simulation. Interesting applications of such a device are discussed.


title: Constraints on Scalar Dark Matter from Direct Experimental Searches

abstract:
  The standard model (SM) plus a real gauge-singlet scalar field dubbed darkon
(SM+D) is the simplest model possessing a weakly interacting massive particle
(WIMP) dark-matter candidate. The upper limits for the WIMP-nucleon elastic
cross-section as a function of WIMP mass from the recent XENON10 and CDMS-II
experiments rule out darkon mass ranges from 10 to (50,70,75) GeV for
Higgs-boson masses of (120,200,350) GeV, respectively. This may exclude the
possibility of the darkon providing an explanation for the gamma-ray excess
observed in the EGRET data. We show that by extending the SM+D to a
two-Higgs-doublet model plus a darkon the experimental constraints on the
WIMP-nucleon interactions can be circumvented due to suppression occurring at
some values of the product tan(alpha)tan(beta), with alpha being the
neutral-Higgs mixing angle and tan(beta) the ratio of vacuum expectation values
of the Higgs doublets. We also comment on the implication of the darkon model
for Higgs searches at the LHC.


title:
Estimation of missing data by using the filtering process in a time
  series modeling

abstract:
  This paper proposed a new method to estimate the missing data by using the
filtering process. We used datasets without missing data and randomly missing
data to evaluate the new method of estimation by using the Box - Jenkins
modeling technique to predict monthly average rainfall for site 5504035 Lahar
Ikan Mati at Kepala Batas, P. Pinang station in Malaysia. The rainfall data was
collected from the $1^{st}$ January 1969 to $31^{st}$ December 1997 in the
station. The data used in the development of the model to predict rainfall were
represented by an autoregressive integrated moving - average (ARIMA) model. The
model for both datasets was ARIMA$(1,0,0)(0,1,1)_s$. The result checked with
the Naive test, which is the Thiel's statistic and was found to be equal to
$U=0.72086$ for the complete data and $U=0.726352$ for the missing data, which
mean they were good models.


title:
Resonant charge and spin transport in a t-stub coupled to a
  superconductor

abstract:
  We study transport through a single channel t-stub geometry strongly coupled
to a superconducting reservoir. In contrast to the standard stub geometry which
has both transmission resonances and anti-resonances in the coherent limit, we
find that due to the proximity effect, this geometry shows neither a T=1
resonance (T is the transmission probability for electrons incident on the
t-stub) nor a T=0 anti-resonance as we vary the energy of the incident
electron. Instead, we find that there is only one resonant value at T=1/4,
where charge transport vanishes while the spin transport is perfect.


title:
The Numerical Solution of Scalar Field for Nariai Case in 5D Ricci-flat
  SdS Black String Space with Polynomial Approximation

abstract:
  As one exact candidate of the higher dimensional black hole, the 5D
Ricci-flat Schwarzschild-de Sitter black string space presents something
interesting. In this paper, we give a numerical solution to the real scalar
field around the Nariai black hole by the polynomial approximation. Unlike the
previous tangent approximation, this fitting function makes a perfect match in
the leading intermediate region and gives a good description near both the
event and the cosmological horizons. We can read from our results that the wave
is close to a harmonic one with the tortoise coordinate. Furthermore, with the
actual radial coordinate the waves pile up almost equally near the both
horizons.


title: Asymptotics for Kotz Type III Elliptical Distributions

abstract:
  In this paper we derive the tail asymptotics of a Kotz Type III elliptical
random vector. As an application of our asymptotic expansion we derive an
approximation for the conditional excess distribution. Furthermore, we discuss
the asymptotic dependence of Kotz Type III triangular arrays and provide some
details on the estimation of conditional excess distribution and survivor
function.


title: Complete Adiabatic Quantum Search in Unsorted Databases

abstract:
  We propose a new adiabatic algorithm for the unsorted database search
problem. This algorithm saves two thirds of qubits than Grover's algorithm in
realizations. Meanwhile, we analyze the time complexity of the algorithm by
both perturbative method and numerical simulation. The results show it provides
a better speedup than the previous adiabatic search algorithm.


title: Folding Kinetics of Proteins and Cold Denaturation

abstract:
  Folding kinetics of a lattice model of protein is studied. It uses the Random
Energy Model for the intrachain couplings and a temperature dependent free
energy of solvation derived from a realistic hydration model of apolar solutes.
The folding times are computed using Monte Carlo simulations in the region of
the phase diagram where the chain occurs in the native structure. These folding
times are roughly equals for the temperatures of cold and warm denaturation for
a large range of solvent quality. Between these temperatures, the folding times
reach maxima and thus, at low temperatures, the kinetics of the chain always
speeds up as the temperature is decreased. The study of the conformational
space as function of the temperature permits to elucidate this phenomenon. At
low temperature, it shows that the activation barriers of the system decrease
faster than the temperature as the temperature is decreased. At high
temperature, the rate of the barriers over the temperature decreases as the
temperature is increased because the height of the barrier is almost constant.


title: Dynamical Casimir Effect for a Swinging Cavity

abstract:
  The resonant scalar particle generation for a swinging cavity resonator in
the Casimir vacuum is examined. It is shown that the number of particles grows
exponentially when the cavity rotates at some specific external frequency.


title: Jet quenching and direct photon production

abstract:
  Jet quenching effect has been investigated in the direct photon production,
based on a realistic data-constrained (3+1) dimensional hydrodynamic
description of the expanding hot and dense matter, a reasonable treatment of
the propagation of partons and their energy loss in the fluid, and a systematic
study of the main sources of direct photons. Our resultant $\pt$ spectra agree
with recent PHENIX data in a broad $\pt$ range. Parton energy loss in the
plasma eventually effect significantly direct photon production from
fragmentation and jet photon conversion, similar to hadron suppression in
central heavy ion collisions. But this only causes about 40% decrease in the
total production of direct photons, due to the mixture with other direct photon
sources.


title: A topological charge selection rule for phase singularities

abstract:
  We present an study of the dynamics and decay pattern of phase singularities
due to the action of a system with a discrete rotational symmetry of finite
order. A topological charge conservation rule is identified. The role played by
the underlying symmetry is emphasized. An effective model describing the short
range dynamics of the vortex clusters has been designed. A method to engineer
any desired configuration of clusters of phase singularities is proposed. Its
flexibility to create and control clusters of vortices is discussed.


title: Strong decays of radially excited mesons in a chiral approach

abstract:
  We study radial excitations of pseudoscalar and vector (q bar q) mesons
within a chiral approach. We derive a general form for a chiral Lagrangian
describing processes involving excited pseudoscalar and vector mesons. The
parameters of the chiral Lagrangian are fitted using data and previous
calculations in the framework of the 3P0 model. Finite-width effects are
examined and predictions for mesons previously not discussed are given.
Available experimental data is analyzed whenever possible. Possible hints for
exotic mesons and open interpretation-issues are discussed.


title: Phase behavior and rheology of sticky rod-like particles

abstract:
  We construct colloidal ``sticky'' rods from the semi-flexible filamentous fd
virus and temperature-sensitive polymers poly(N-isopropylacrylamide) (PNIPAM).
The phase diagram of fd-PNIPAM system becomes independent of ionic strength at
high salt concentration and low temperature, i.e. the rods are sterically
stabilized by the polymer. However, the network of sticky rods undergoes a
sol-gel transition as the temperature is raised. The viscoelastic moduli of fd
and fd-PNIPAM suspensions are compared as a function of temperature, and the
effect of ionic strength on the gelling behavior of fd-PNIPAM solution is
measured. For all fluidlike and solidlike samples, the frequency-dependant
linear viscoelastic moduli can be scaled onto universal master curves.


title: Neutron diffraction constraint on spin-dependent short range interaction

abstract:
  The direct constraint on the parameters of short range pseudomagnetic
interaction of free neutron with matter is obtained from the recent test
experiment on a search for neutron EDM by crystal-diffraction method. It is
shown that this constraint on a product of scalar to pseudo-scalar coupling
constants $g_s g_p$ is better than that of any other method for the range
$\lambda < 10^{-5}$cm.


title: All-Optical Formation of Quantum Degenerate Mixtures

abstract:
  We report the realization of quantum degenerate mixed gases of ytterbium (Yb)
isotopes using all-optical methods. We have succeeded in cooling attractively
interacting 176Yb atoms via sympathetic cooling down to below the Bose-Einstein
transition temperature, coexisting with a stable condensate of 174Yb atoms with
a repulsive interaction. We have observed a rapid atom loss in 176Yb atoms
after cooling down below the transition temperature, which indicates the
collapse of a 176Yb condensate. The sympathetic cooling technique has been
applied to cool a 173Yb-174Yb Fermi-Bose mixture to the quantum degenerate
regime.


title:
On the Behrens--Fisher problem: A globally convergent algorithm and a
  finite-sample study of the Wald, LR and LM Tests

abstract:
  In this paper we provide a provably convergent algorithm for the multivariate
Gaussian Maximum Likelihood version of the Behrens--Fisher Problem. Our work
builds upon a formulation of the log-likelihood function proposed by Buot and
Richards \citeBR. Instead of focusing on the first order optimality conditions,
the algorithm aims directly for the maximization of the log-likelihood function
itself to achieve a global solution. Convergence proof and complexity estimates
are provided for the algorithm. Computational experiments illustrate the
applicability of such methods to high-dimensional data. We also discuss how to
extend the proposed methodology to a broader class of problems. We establish a
systematic algebraic relation between the Wald, Likelihood Ratio and Lagrangian
Multiplier Test ($W\geq \mathit{LR}\geq \mathit{LM}$) in the context of the
Behrens--Fisher Problem. Moreover, we use our algorithm to computationally
investigate the finite-sample size and power of the Wald, Likelihood Ratio and
Lagrange Multiplier Tests, which previously were only available through
asymptotic results. The methods developed here are applicable to much higher
dimensional settings than the ones available in the literature. This allows us
to better capture the role of high dimensionality on the actual size and power
of the tests for finite samples.


title: Planet formation in the habitable zone of alpha Centauri B

abstract:
  Recent studies have shown that alpha Centauri B might be, from an
observational point of view, an ideal candidate for the detection of an
Earth-like planet in or near its habitable zone (0.5-0.9AU). We study here if
such habitable planets can form, by numerically investigating the
planet-formation stage which is probably the most sensitive to binarity
effects: the mutual accretion of km-sized planetesimals. Using a
state-of-the-art algorithm for computing the impact velocities within a test
planetesimal population, we find that planetesimal growth is only possible,
although marginally, in the innermost part of the HZ around 0.5AU. Beyond this
point, the combination of secular perturbations by the binary companion and gas
drag drive the mutual velocities beyond the erosion limit. Impact velocities
might later decrease during the gas removal phase, but this probably happens
too late for preventing most km-sized objects to be removed by inward drift,
thus preventing accretion from starting anew. A more promising hypothesis is
that the binary formed in a crowded cluster, where it might have been wider in
its initial stages, when planetary formation was ongoing. We explore this
scenario and find that a starting separation roughly 15 AU wider, or an
eccentricity 2.5 times lower than the present ones are required to have an
accretion-friendly environment in the whole HZ.


title:
Kaehler-Einstein submanifolds of the infinite dimensional projective
  space

abstract:
  This paper consists of two main results. In the first one we describe all
Kaehler immersions of a bounded symmetric domain into the infinite dimensional
complex projective space in terms of the Wallach set of the domain. In the
second one we exhibit an example of complete and non-homogeneous
Kaehler-Einstein metric with negative scalar curvature which admits a Kaehler
immersion into the infinite dimensional complex projective space.


title:
The uncertainties due to quark energy loss on determining nuclear sea
  quark distribution from nuclear Drell-Yan data

abstract:
  By means of two different parametrizations of quark energy loss and the
nuclear parton distributions determined only with lepton-nuclear deep inelastic
scattering experimental data, a leading order phenomenological analysis is
performed on the nuclear Drell-Yan differential cross section ratios as a
function of the quark momentum fraction in the beam proton and target nuclei
for E772 experimental data. It is shown that there is the quark energy loss
effect in nuclear Drell-Yan process apart from the nuclear effects on the
parton distribution as in deep inelastic scattering. The uncertainties due to
quark energy loss effect is quantified on determining nuclear sea quark
distribution by using nuclear Drell-Yan data. It is found that the quark energy
loss effect on nuclear Drell-Yan cross section ratios make greater with the
increase of quark momentum fraction in the target nuclei. The uncertainties
from quark energy loss become bigger as the nucleus A come to be heavier. The
Drell-Yan data on proton incident middle and heavy nuclei versus deuterium
would result in an overestimate for nuclear modifications on sea quark
distribution functions with neglecting the quark energy loss. Our results are
hoped to provide good directional information on the magnitude and form of
nuclear modifications on sea quark distribution functions by means of the
nuclear Drell-Yan experimental data.


title: Transport gap in side-gated graphene constrictions

abstract:
  We present measurements on side gated graphene constrictions of different
geometries. We characterize the transport gap by its width in back gate voltage
and compare this to an analysis based on Coulomb blockade measurements of
localized states. We study the effect of an applied side gate voltage on the
transport gap and show that high side gate voltages lift the suppression of the
conductance. Finally we study the effect of an applied magnetic field and
demonstrate the presence of edge states in the constriction.


title: A simulation of hard spheres gas for educational purposes

abstract:
  We describe an educational simulation of some effects within the gas of hard
spheres. The focus of the presented simulation is on the comprehension of
random character of the velocity of molecules in the gas and of the energy at
fixed temperature. It allows to point out the connection between the
temperature, the energy, and the velocity of the molecules.


title: Probability measures, L\'{e}vy measures and analyticity in time

abstract:
  We investigate the relation of the semigroup probability density of an
infinite activity L\'{e}vy process to the corresponding L\'{e}vy density. For
subordinators, we provide three methods to compute the former from the latter.
The first method is based on approximating compound Poisson distributions, the
second method uses convolution integrals of the upper tail integral of the
L\'{e}vy measure and the third method uses the analytic continuation of the
L\'{e}vy density to a complex cone and contour integration. As a by-product, we
investigate the smoothness of the semigroup density in time. Several concrete
examples illustrate the three methods and our results.


title:
Trigonometric Parallaxes of Massive Star Forming Regions: II. Cep A &
  NGC 7538

abstract:
  We report trigonometric parallaxes for the sources NGC 7538 and Cep A,
corresponding to distances of 2.65 [+0.12/-0.11] kpc and 0.70 [+0.04/-0.04]
kpc, respectively. The distance to NGC 7538 is considerably smaller than its
kinematic distance and places it in the Perseus spiral arm. The distance to Cep
A is also smaller than its kinematic distance and places it in the Local arm or
spur. Combining the distance and proper motions with observed radial velocities
gives the location and full space motion of the star forming regions. We find
significant deviations from circular Galactic orbits for these sources: both
sources show large peculiar motions (> 10 km/s) counter to Galactic rotation
and NGC 7538 has a comparable peculiar motion toward the Galactic center.


title: On (non)commutative products of functions on the sphere

abstract:
  We investigate the commutativity of global products of functions on the
two-sphere from the point of view of a construction started in [RT] and named
the skewed product. We complete the construction of the skewed product of
functions on the sphere and show that it is Z_2 graded commutative and
nontrivial only as a product of functions with correct parity under the
antipodal mapping. These properties are valid for a more general class of
integral products of functions on the sphere, with integral kernel of a special
WKB-type that is natural from semiclassical considerations. We argue that our
construction provides a simple geometrical explanation for an old theorem by
Rieffel [Rf] on equivariant strict deformation quantization of the two-sphere.


title: NLTE abundances of Mn in a sample of metal-poor stars

abstract:
  Following our solar work, we perform NLTE calculations of the Mn abundance
for fourteen stars with [Fe/H] from 0 to -2.5, mainly to show how NLTE affects
Mn abundances in cool stars of different metallicities.The spectrum synthesis
and Mn abundances are based on statistical equilibrium calculations using
various estimates for the influence of hydrogen collisions.The NLTE abundances
of Mn in all studied stars are systematically higher than the LTE abundances.
At low metallicities, the NLTE abundance corrections may run up to 0.5 - 0.7
dex. Instead of a strong depletion of Mn relative to Fe in metal-poor stars as
found by the other authors, we only find slightly subsolar values of [Mn/Fe]
throughout the range of metallicities analyzed here. The [Mn/Fe] trend in
metal-poor stars is inconsistent with the predictions of galactic chemical
evolution models, where Mn is less produced than Fe.


title:
Anisotropic KPZ growth in 2+1 dimensions: fluctuations and covariance
  structure

abstract:
  In [arXiv:0804.3035] we studied an interacting particle system which can be
also interpreted as a stochastic growth model. This model belongs to the
anisotropic KPZ class in 2+1 dimensions. In this paper we present the results
that are relevant from the perspective of stochastic growth models, in
particular: (a) the surface fluctuations are asymptotically Gaussian on a
sqrt(ln(t)) scale and (b) the correlation structure of the surface is
asymptotically given by the massless field.


title: An Algorithmic and a geometric characterization of coarsening at random

abstract:
  We show that the class of conditional distributions satisfying the coarsening
at random (CAR) property for discrete data has a simple and robust algorithmic
description based on randomized uniform multicovers: combinatorial objects
generalizing the notion of partition of a set. However, the complexity of a
given CAR mechanism can be large: the maximal "height" of the needed
multicovers can be exponential in the number of points in the sample space. The
results stem from a geometric interpretation of the set of CAR distributions as
a convex polytope and a characterization of its extreme points. The hierarchy
of CAR models defined in this way could be useful in parsimonious statistical
modeling of CAR mechanisms, though the results also raise doubts in applied
work as to the meaningfulness of the CAR assumption in its full generality.


title:
Short Gamma-Ray Bursts and Gravitational Waves from Dynamically Formed
  Merging Binaries

abstract:
  Merging binary systems consisting of two collapsed objects are among the most
promising sources of high frequency gravitational wave, GW, signals for ground
based interferometers. Double neutron star or black hole/neutron star mergers
are also believed to give rise to short hard bursts, SHBs, a subclass of gamma
ray bursts. SHBs might thus provide a powerful way to infer the merger rate of
two-collapsed object binaries. Under the hypothesis that most SHBs originate
from double neutron star or black hole/neutron star mergers, we outline here a
method to estimate the incidence of merging events from dynamically formed
binaries in globular clusters and infer the corresponding GW event rate that
can be detected with Advanced LIGO/Virgo. In particular a sizeable fraction of
detectable GW events is expected to be coincident with SHBs. The beaming and
redshift distribution of SHBs are reassessed and their luminosity function
constrained by using the results from recent SHBs observations. We confirm that
a substantial fraction of SHBs goes off at low redshifts, where the merging of
systems formed in globular clusters through dynamical interactions is expected.


title:
Josephson current in ballistic heterostructures with spin-active
  interfaces

abstract:
  We develop a general microscopic theory of dc Josephson effect in hybrid SNS
structures with ballistic electrodes and spin-active NS interfaces. We
establish a direct relation between the spectrum of Andreev levels and the
Josephson current which contains complete information about non-trivial
interplay between Andreev reflection and spin-dependent interface scattering.
The system exhibits a rich structure of properties sensitive to spin-dependent
barrier transmissions, spin-mixing angles, relative magnetization orientation
of interfaces and the kinematic phase of scattered electrons. We analyze the
current-phase relations and identify the conditions for the presence of a
pi-junction state in the systems under consideration. We also analyze resonant
enhancement of the supercurrent in gate-voltage-driven nanojunctions. As
compared to the non-magnetic case, this effect can be strongly modified by
spin-dependent scattering at NS interfaces.


title: $L$-approximation of $B$-splines by trigonometric polynomials

abstract:
  This note is a continuation of our papers [1,2], devoted to $L$-approximation
of characteristic function of $(-h, h)$ by trigonometric polynomials. In the
paper [1] the sharp values of the best approximation for the special values of
$h$ were found. In [2] we gave the complete solution of the problem for
arbitrary values of $h$. In general case [2] the situation is more deep and
results are not so simple as in [1]. For applications to the problem of optimal
constants in the Jackson-type inequalities we need, however, results on
$L$-approximation of $B$-splines and linear combinations of $B$-splines. Here
we present some simple results about $L$-approximation of $B$-splines as well
as give the the proof of its sharpness for the special values of $h$.


title: The Brauer Group of a Smooth Orbifold

abstract:
  Let $k$ be a field and $X/k$ be a smooth quasiprojective orbifold. Let $X\to
\underline{X}$ be its coarse moduli space. In this paper we study the Brauer
group of $X$ and compare it with the Brauer group of the smooth locus of
$\underline{X}$.


title:
Choose interelement coupling to preserve self-adjoint dynamics in
  multiscale modelling and computation

abstract:
  Consider the macroscale modelling of microscale spatiotemporal dynamics. Here
we develop a new approach to ensure coarse scale discrete models preserve
important self-adjoint properties of the fine scale dynamics. The first part
explores the discretisation of microscale continuum dynamics. The second
addresses how dynamics on a fine lattice are mapped to lattice a factor of two
coarser (as in multigrids). Such mapping of discrete lattice dynamics may be
iterated to empower us in future research to explore scale dependent emergent
phenomena. The support of dynamical systems, centre manifold, theory ensures
that the coarse scale modelling applies with a finite spectral gap, in a finite
domain, and for all time. The accuracy of the models is limited by the
asymptotic resolution of subgrid coarse scale processes, and is controlled by
the level of truncation. As given examples demonstrate, the novel feature of
the approach developed here is that it ensures the preservation of important
conservation properties of the microscale dynamics.


title:
Deformation of a smooth Deligne-Mumford stack via differential graded
  Lie algebra

abstract:
  For a smooth Deligne-Mumford stack over $\CC$, we define its associated
Kodaira-Spencer differential graded Lie algebra and show that the deformation
functor of the stack is isomorphic to the deformation functor of the
Kodaira-Spencer algebra if the stack is proper over $\CC$.


title: Particles as probes for complex plasmas in front of biased surfaces

abstract:
  An interesting aspect in the research of complex (dusty) plasmas is the
experimental study of the interaction of micro-particles with the surrounding
plasma for diagnostic purposes. Local electric fields can be determined from
the behaviour of particles in the plasma, e.g. particles may serve as
electrostatic probes. Since in many cases of applications in plasma technology
it is of great interest to describe the electric field conditions in front of
floating or biased surfaces, the confinement and behaviour of test particles is
studied in front of floating walls inserted into a plasma as well as in front
of additionally biased surfaces. For the latter case, the behaviour of
particles in front of an adaptive electrode, which allows for an efficient
confinement and manipulation of the grains, has been experimentally studied in
dependence on the discharge parameters and on different bias conditions of the
electrode. The effect of the partially biased surface (dc, rf) on the charged
micro-particles has been investigated by particle falling experiments. In
addition to the experiments we also investigate the particle behaviour
numerically by molecular dynamics, in combination with a fluid and
particle-in-cell description of the plasma.


title:
Sigma-model approaches to exact solutions in higher-dimensional gravity
  and supergravity

abstract:
  Classical gravitating field theories reduced to three dimensions admit
manifest gauge invariances and hidden symmetries, which together make up the
invariance group G of the theory. If this group is large enough, the target
space is a symmetric space G/H. New solutions may be generated by the action of
invariance transformations on a seed solution. Another application is the
construction of multicenter solutions from null geodesics of the target space.
After a general introduction on this sigma-model approach, I will discuss the
case of five-dimensional gravity, with invariace group SL(3,R), and minimal
five-dimensional supergravity, with invariance group G_{2(2)}. I will also
describe recent attempts at the generation of new charged rotating black rings.


title:
X-Ray Spectral Variability of the Seyfert Galaxy NGC 4051 Observed with
  Suzaku

abstract:
  We report results from a Suzaku observation of the narrow-line Seyfert 1 NGC
4051. During our observation, large amplitude rapid variability is seen and the
averaged 2--10 keV flux is 8.1x10^-12 erg s^-1 cm^-2, which is several times
lower than the historical average. The X-ray spectrum hardens when the source
flux becomes lower, confirming the trend of spectral variability known for many
Seyfert 1 galaxies. The broad-band averaged spectrum and spectra in high and
low flux intervals are analyzed. The spectra are first fitted with a model
consisting of a power-law component, a reflection continuum originating in cold
matter, a blackbody component, two zones of ionized absorber, and several
Gaussian emission lines. The amount of reflection is rather large (R ~ 7, where
R=1 corresponds to reflection by an infinite slab), while the equivalent width
of the Fe-K line at 6.4 keV is modest (140 eV) for the averaged spectrum. We
then model the overall spectra by introducing partial covering for the
power-law component and reflection continuum independently. The column density
for the former is 1x10^23 cm^-2, while it is fixed at 1x10^24 cm-2 for the
latter. By comparing the spectra in different flux states, we identify the
causes of spectral variability. (abridged)


title: Estimating the solar meridional circulation by normal mode decomposition

abstract:
  The objective of this article is to use Fourier-Hankel decomposition as
suggested earlier by Braun & Fan (1998) to estimate the integrated horizontal
meridional flow velocity as a function of mode penetration depth, and to find
ways of potentially improve this technique. We use a time series of 43200 (30
days) consecutive full-disk Dopplergrams obtained by the MDI (Michelson Doppler
Imager) instrument aboard the SOHO (Solar Heliospheric Observatory) spacecraft
in April 1999. We find averaged meridional flow estimates of 15 m/s for modes
with a penetration depth in the upper 20 Mm of the solar convection zone. This
reproduces the results of the earlier investigations. Moreover we conclude that
this method has the potential to become a new technique to measure the
meridional circulation in the deep convection zone, if some improvements will
be applied.


title: Energy gaps in etched graphene nanoribbons

abstract:
  Transport measurements on an etched graphene nanoribbon are presented. It is
shown that two distinct voltage scales can be experimentally extracted that
characterize the parameter region of suppressed conductance at low charge
density in the ribbon. One of them is related to the charging energy of
localized states, the other to the strength of the disorder potential. The
lever arms of gates vary by up to 30% for different localized states which must
therefore be spread in position along the ribbon. A single-electron transistor
is used to prove the addition of individual electrons to the localized states.
In our sample the characteristic charging energy is of the order of 10 meV, the
characteristic strength of the disorder potential of the order of 100 meV.


title: Dark resonances for ground state transfer of molecular quantum gases

abstract:
  One possible way to produce ultracold, high-phase-space-density quantum gases
of molecules in the rovibronic ground state is given by molecule association
from quantum-degenerate atomic gases on a Feshbach resonance and subsequent
coherent optical multi-photon transfer into the rovibronic ground state. In
ultracold samples of Cs_2 molecules, we observe two-photon dark resonances that
connect the intermediate rovibrational level |v=73,J=2> with the rovibrational
ground state |v=0,J=0> of the singlet $X^1\Sigma_g^+$ ground state potential.
For precise dark resonance spectroscopy we exploit the fact that it is possible
to efficiently populate the level |v=73,J=2> by two-photon transfer from the
dissociation threshold with the stimulated Raman adiabatic passage (STIRAP)
technique. We find that at least one of the two-photon resonances is
sufficiently strong to allow future implementation of coherent STIRAP transfer
of a molecular quantum gas to the rovibrational ground state |v=0,J=0>.


title: Status of neutrino astronomy

abstract:
  Astrophysical neutrinos can be produced in proton interactions of charged
cosmic rays with ambient photon or baryonic fields. Cosmic rays are observed in
balloon, satellite and air shower experiments every day, from below 1e9 eV up
to macroscopic energies of 1e21 eV. The observation of different photon fields
has been done ever since, today with detections ranging from radio wavelengths
up to very high-energy photons in the TeV range. The leading question for
neutrino astronomers is now which sources provide a combination of efficient
proton acceleration with sufficiently high photon fields or baryonic targets at
the same time in order to produce a neutrino flux that is high enough to exceed
the background of atmospheric neutrinos. There are only two confirmed
astrophysical neutrino sources up to today: the sun and SuperNova 1987A emit
and emitted neutrinos at MeV energies. The aim of large underground Cherenkov
telescopes like IceCube and KM3NeT is the detection of neutrinos at energies
above 100 GeV. In this paper, recent developments of neutrino flux modeling for
the most promising extragalactic sources, gamma ray bursts and active galactic
nuclei, are presented.


title: Residual empirical processes for long and short memory time series

abstract:
  This paper studies the residual empirical process of long- and short-memory
time series regression models and establishes its uniform expansion under a
general framework. The results are applied to the stochastic regression models
and unstable autoregressive models. For the long-memory noise, it is shown that
the limit distribution of the Kolmogorov-Smirnov test statistic studied in Ho
and Hsing [Ann. Statist. 24 (1996) 992-1024] does not hold when the stochastic
regression model includes an unknown intercept or when the characteristic
polynomial of the unstable autoregressive model has a unit root. To this end,
two new statistics are proposed to test for the distribution of the long-memory
noises of stochastic regression models and unstable autoregressive models.
(With Correction.)


title:
MOND vs. Newtonian dynamics in early-type galaxies. The case of NGC 4649
  (M60)

abstract:
  Context: Regarding the significant interest in both dark matter and the
application of MOND to early-type galaxies, we investigate the MOND theory by
comparing its predictions, for models of constant mass-to-light ratio, with
observational data of the early-type galaxy NGC 4649.
  Aims: We study whether measurements for NGC 3379 and NGC 1399 are typical of
early-type systems and we test the assumption of a Newtonian constant M/L ratio
underlying most of the published models.
  Methods: We employ the globular clusters of NGC 4649 as a mass tracer. The
Jeans equation is calculated for both MOND and constant mass-to-light ratio
assumptions. Spherical symmetry is assumed and the calculations are performed
for both isotropic and anisotropic cases.
  Results: We found that both Jeans models with the assumption of a constant
mass-to-light ratio and different MOND models provide good agreement with the
observed values of the velocity dispersion. The most accurate fits of the
velocity dispersion were obtained for the mass-to-light ratio in the B-band,
which was equal to 7, implying that there is no need for significant amounts of
dark matter in the outer parts (beyond 3 effective radii) of this galaxy. We
also found that tangential anisotropies are most likely present in NGC 4649.


title:
A Note on the Inversion Complexity of Boolean Functions in Boolean
  Formulas

abstract:
  In this note, we consider the minimum number of NOT operators in a Boolean
formula representing a Boolean function. In circuit complexity theory, the
minimum number of NOT gates in a Boolean circuit computing a Boolean function
$f$ is called the inversion complexity of $f$. In 1958, Markov determined the
inversion complexity of every Boolean function and particularly proved that
$\lceil \log_2(n+1) \rceil$ NOT gates are sufficient to compute any Boolean
function on $n$ variables. As far as we know, no result is known for inversion
complexity in Boolean formulas, i.e., the minimum number of NOT operators in a
Boolean formula representing a Boolean function. The aim of this note is
showing that we can determine the inversion complexity of every Boolean
function in Boolean formulas by arguments based on the study of circuit
complexity.


title: The total mass of the early-type galaxy NGC 4649 (M60)

abstract:
  In this paper we analyze the problem of the total mass and the total
mass-to-light ratio of the early-type galaxy NGC 4649 (M60). We have used two
independent techniques: the X-ray methodology which is based on the temperature
of the X-ray halo of NGC 4649 and the tracer mass estimator (TME) which uses
globular clusters (GCs) observed in this galaxy. We calculated the mass in
Newtonian and MOdified Newtonian Dynamics (MOND) approaches and found that
interior to 3 effective radii (Re) there is no need for large amounts of dark
matter. Beyond 3Re dark matter starts to play important dynamical role. We also
discuss possible reasons for the discrepancy between the estimates of the total
mass based on X-rays and TME in the outer regions of NGC 4649.


title:
Trigonometric Parallaxes of Massive Star Forming Regions: III. G59.7+0.1
  and W 51 IRS2

abstract:
  We report trigonometric parallaxes for G59.7+0.1 and W 51 IRS2, corresponding
to distances of 2.16^{+0.10}_{-0.09} kpc and 5.1^{+2.9}_{-1.4} kpc,
respectively. The distance to G59.7+0.1 is smaller than its near kinematic
distance and places it between the Carina-Sagittarius and Perseus spiral arms,
probably in the Local (Orion) spur. The distance to W 51 IRS2, while subject to
significant uncertainty, is close to its kinematic distance and places it near
the tangent point of the Carina-Sagittarius arm. It also agrees well with a
recent estimate based on O-type star spectro/photometry. Combining the
distances and proper motions with observed radial velocities gives the full
space motions of the star forming regions. We find modest deviations of 5 to 10
km/s from circular Galactic orbits for these sources, both counter to Galactic
rotation and toward the Galactic center.


title: Multipartite entanglement in qubit systems

abstract:
  We introduce a potential of multipartite entanglement for a system of n
qubits, as the average over all balanced bipartitions of a bipartite
entanglement measure, the purity. We study in detail its expression and look
for its minimizers, the maximally multipartite entangled states. They have a
bipartite entanglement that does not depend on the bipartition and is maximal
for all possible bipartitions. We investigate their structure and consider
several examples for small n.


title:
Measuring Lepton Flavour Violation at LHC with Long-Lived Slepton in the
  Coannihilation Region

abstract:
  When the mass difference between the lightest slepton, the NLSP, and the
lightest neutralino, the LSP, is smaller than the tau mass, the lifetime of the
lightest slepton increases in many orders of magnitude with respect to typical
lifetimes of other supersymmetric particles. These small mass differences are
possible in the MSSM and, for instance, they correspond to the coannihilation
region of the CMSSM for $M_{1/2} \gsim 700$ GeV. In a general gravity-mediated
MSSM, where the lightest supersymmetric particle is the neutralino, the
lifetime of the lightest slepton is inversely proportional to the square of the
intergenerational mixing in the slepton mass matrices. Such a long-lived
slepton would produce a distinctive signature at LHC and a measurement of its
lifetime would be relatively simple. Therefore, the long-lived slepton scenario
offers an excellent opportunity to study lepton flavour violation at ATLAS and
CMS detectors in the LHC and an improvement of the leptonic mass insertion
bounds by more than five orders of magnitude would be possible.


title:
Trigonometric Parallaxes of Massive Star Forming Regions: IV.
  G35.20-0.74 and G35.20-1.74

abstract:
  We report trigonometric parallaxes for the high-mass star forming regions
G35.20-0.74 and G35.20-1.74, corresponding to distances of 2.19 (+0.24 -0.20)
kpc and 3.27 (+0.56 -0.42) kpc, respectively. The distances to both sources are
close to their near kinematic distances and place them in the
Carina-Sagittarius spiral arm. Combining the distances and proper motions with
observed radial velocities gives the locations and full space motions of the
star forming regions. Assuming a standard model of the Galaxy, G35.20-0.74 and
G35.20-1.74 have peculiar motions of ~13 km/s and ~16 km/s counter to Galactic
rotation and ~9 km/s toward the North Galactic Pole.


title: The Design of Sparse Antenna Array

abstract:
  The aim of antenna array synthesis is to achieve a desired radiation pattern
with the minimum number of antenna elements. In this paper the antenna
synthesis problem is studied from a totally new perspective. One of the key
principles of compressive sensing is that the signal to be sensed should be
sparse or compressible. This coincides with the requirement of minimum number
of element in the antenna array synthesis problem. In this paper the antenna
element of the array can be efficiently reduced via compressive sensing, which
shows a great improvement to the existing antenna synthesis method. Moreover,
the desired radiation pattern can be achieved in a very computation time which
is even shorter than the existing method. Numerical examples are presented to
show the high efficiency of the proposed method.


title:
Travelling wave solutions of BBM-like equations by means of
  factorization

abstract:
  In this work, we apply the factorization technique to the
Benjamin-Bona-Mahony like equations, B(m,n), in order to get travelling wave
solutions. We will focus on some special cases for which m is not equal to n,
and we will obtain these solutions in terms of Weierstrass functions.


title: Neutrinos as cosmic messengers

abstract:
  I briefly review the current status of neutrino oscillation parameters and
discuss the role of neutrinos as cosmological probes, that could possibly
induce the baryon asymmetry as well as the dark matter in the Universe. I
comment on the origin of neutrino masses in seesaw-type and low-scale models
and mention some of their laboratory signals.


title: Leptonic $Z$ decays in the littlest $Higgs$ model with T-parity

abstract:
  The littlest $Higgs$ model with T-parity (called the $LHT$ model) predicts
the existence of the T-odd leptons, which can generate contributions to some
leptonic processes at the one-loop level. We calculate their contributions to
the leptonic $Z$ decay processes $Z\to l\bar{l'}$, $Z\to l\bar{l}$, and
$Z\rightarro \nu\bar{\nu}$. We find that the T-odd leptons can give significant
contributions to the branching ratios of these decay processes in most of the
parameter space. The experimental measurement values might generate constraints
on the free parameters of the $LHT$ model.


title: MMOGs as Social Experiments: the Case of Environmental Laws

abstract:
  In this paper we argue that Massively Multiplayer Online Games (MMOGs), also
known as Large Games are an interesting research tool for policy
experimentation. One of the major problems with lawmaking is that testing the
laws is a difficult enterprise. Here we show that the concept of an MMOG can be
used to experiment with environmental laws on a large scale, provided that the
MMOG is a real game, i.e., it is fun, addictive, presents challenges that last,
etc.. We present a detailed game concept as an initial step.


title: On a Lomonaco-Kauffman conjecture

abstract:
  Samuel J. Lomonaco Jr and Louis H. Kauffman conjectured that tame knot theory
and knot mosaic theory are equivalent. We give a proof of the Lomonaco-Kauffman
conjecture.


title: Superconductivity in S-substituted FeTe

abstract:
  We have successfully synthesized a new superconducting phase of FeTe1-xSx
with a PbO-type structure. It has the simplest crystal structure in iron-based
superconductors. Superconducting transition temperature is about 10 K at x =
0.2. The upper critical field Hc2 was estimated to be ~70 T. The coherent
length was calculated to be ~2.2 nm. Because FeTe1-xSx is composed of nontoxic
elements, this material is a candidate for applications and will activate more
and more research on iron-based superconductor.


title: On Virtual Crossing Number Estimates For Virtual Links

abstract:
  We address the question of detecting minimal virtual diagrams with respect to
the number of virtual crossings. This problem is closely connected to the
problem of detecting the minimal number of additional intersection points for a
generic immersion of a singular link in $R^{2}$.
  We tackle this problem by the so-called $\xi$-polynomial whose leading
(lowest) degree naturally estimates the virtual crossing number.
  Several sufficient conditions for minimality together with infinite series of
new examples are given.
  We also state several open questions about $M$-diagrams, which are minimal
according to our sufficient conditions.


title:
Trigonometric Parallaxes of Massive Star Forming Regions: V. G23.01-0.41
  and G23.44-0.18

abstract:
  We report trigonometric parallaxes for the massive star-forming regions
G23.01-0.41 and G23.44-0.18, corresponding to distances of 4.59 [+0.38/-0.33]
kpc and 5.88 [+1.37/-0.93] kpc, respectively. The distance to G23.01-0.41 is
smaller than its near kinematic distance assuming a standard model of the Milky
Way and less than half of its far kinematic distance, which has usually been
assumed. This places it in the Crux-Scutum spiral arm. The distance to
G23.44-0.18 is close to its near kinematic distance and most likely places it
in the Norma spiral arm near the end of the Galactic bar. Combining the
distance and proper motions with observed radial velocities gives the location
and full space motion of the star forming regions. We find large deviations
from circular Galactic orbits for these sources: both sources show peculiar
motions of 20 to 30 km/s counter to Galactic rotation and toward the Galactic
center. These large peculiar motions might be the result of gravitational
perturbations from the Galactic bar.


title:
Exact and approximate relations for the spin-dependence of the exchange
  energy in high magnetic fields

abstract:
  The exchange energy of an arbitrary collinear-spin many-body system in an
external magnetic field is a functional of the spin-resolved charge and current
densities, $E_x[n_{\uparrow},n_{\downarrow},j_{\uparrow},j_{\downarrow}]$.
Within the framework of density-functional theory (DFT), we show that the
dependence of this functional on the four densities can be fully reconstructed
from either of two extreme limits: a fully polarized system or a completely
unpolarized system. Reconstruction from the limit of an unpolarized system
yields a generalization of the Oliver-Perdew spin scaling relations from
spin-DFT to current-DFT. Reconstruction from the limit of a fully polarized
system is used to derive the high-field form of the local-spin-density
approximation to current-DFT and to magnetic-field DFT.


title:
Towards Relativistic Atomic Physics. II. Collective and Relative
  Relativistic Variables for a System of Charged Particles plus the
  Electro-Magnetic Field

abstract:
  In this second paper we complete the classical description of an isolated
system of "charged positive-energy particles, with Grassmann-valued electric
charges and mutual Coulomb interaction, plus a transverse electro-magnetic
field" in the rest-frame instant form of dynamics.
  In particular we show how to determine a collective variable associated with
the internal 3-center of mass on the instantaneous 3-spaces, to be eliminated
with the constraints ${\vec {\cal K}}_{(int)} \approx 0$. Here ${\vec {\cal
K}}_{(int)}$ is the Lorentz boost generator in the unfaithful internal
realization of the Poincare' group and its vanishing is the gauge fixing to the
rest-frame conditions ${\vec {\cal P}}_{(int)} \approx 0$. We show how to find
this collective variable for the following isolated systems: a) charged
particles with a Coulomb plus Darwin mutual interaction; b) transverse
radiation field; c) charged particles with a mutual Coulomb interaction plus a
transverse electro-magnetic field.
  Then we define the Dixon multipolar expansion for the open particle
subsystem. We also define the relativistic electric dipole approximation of
atomic physics in the rest-frame instant form and we find the a possible
relativistic generalization of the electric dipole representation.


title: Multiple Quantum NMR Dynamics in Pseudopure States

abstract:
  We investigate numerically the Multiple Quantum (MQ) NMR dynamics in systems
of nuclear spins 1/2 coupled by the dipole-dipole interactions in the case of
the pseudopure initial state. Simulations of the MQ NMR with the real molecular
structures such as six dipolar-coupled proton spins of a benzene, hydroxyl
proton chains in calcium hydroxyapatite and fluorine chains in calcium
fluorapatite open the way to experimental NMR testing of the obtained results.
It was found that multiple-spin correlations are created faster in such
experiments than in the usual MQ NMR experiments and can be used for the
investigation of many-spin dynamics of nuclear spins in solids


title:
Visualization of association graphs for assisting the interpretation of
  classifications

abstract:
  Given a query on the PASCAL database maintained by the INIST, we design user
interfaces to visualize and browse two types of graphs extracted from
abstracts: 1) the graph of all associations between authors (co-author graph),
2) the graph of strong associations between authors and terms automatically
extracted from abstracts and grouped using linguistic variations. We adapt for
this purpose the TermWatch system that comprises a term extractor, a relation
identifier which yields the terminological network and a clustering module. The
results are output on two interfaces: a graphic one mapping the clusters in a
2D space and a terminological hypertext network allowing the user to
interactively explore results and return to source texts.


title:
The first two transient supersoft X-ray sources in M 31 globular
  clusters and the connection to classical novae

abstract:
  Classical novae (CNe) have been found to represent the major class of
supersoft X-ray sources (SSS) in our neighbour galaxy M 31. We determine
properties and evolution of the two first SSSs ever discovered in the M 31
globular cluster (GC) system. We have used XMM-Newton, Chandra and Swift
observations of the centre region of M 31 to discover both SSS and to determine
their X-ray light curves and spectra. We performed detailed analysis of
XMM-Newton EPIC PN spectra of the source in Bol 111 (SS1) using blackbody and
NLTE white dwarf (WD) atmosphere models. For the SSS in Bol 194 (SS2) we used
optical monitoring data to search for an optical counterpart. Both GC X-ray
sources were classified as SSS. We identify SS1 with the CN M31N 2007-06b
recently discovered in the M 31 GC Bol 111. For SS2 we did not find evidence
for a recent nova outburst and can only provide useful constraints on the time
of the outburst of a hypothetical nova. The only known CN in a M 31 GC can be
identified with the first SSS found in a M31 GC. We discuss the impact of our
observations on the nova rate for the M 31 GC system.


title: Web Usage Analysis: New Science Indicators and Co-usage

abstract:
  A new type of statistical analysis of the science and technical information
(STI) in the Web context is produced. We propose a set of indicators about Web
users, visualized bibliographic records, and e-commercial transactions. In
addition, we introduce two Web usage factors. Finally, we give an overview of
the co-usage analysis. For these tasks, we introduce a computer based system,
called Miri@d, which produces descriptive statistical information about the Web
users' searching behaviour, and what is effectively used from a free access
digital bibliographical database. The system is conceived as a server of
statistical data which are carried out beforehand, and as an interactive server
for online statistical work. The results will be made available to analysts,
who can use this descriptive statistical information as raw data for their
indicator design tasks, and as input for multivariate data analysis, clustering
analysis, and mapping. Managers also can exploit the results in order to
improve management and decision-making.


title: Spin dynamics in high-mobility two-dimensional electron systems

abstract:
  Understanding the spin dynamics in semiconductor heterostructures is highly
important for future semiconductor spintronic devices. In high-mobility
two-dimensional electron systems (2DES), the spin lifetime strongly depends on
the initial degree of spin polarization due to the electron-electron
interaction. The Hartree-Fock (HF) term of the Coulomb interaction acts like an
effective out-of-plane magnetic field and thus reduces the spin-flip rate. By
time-resolved Faraday rotation (TRFR) techniques, we demonstrate that the spin
lifetime is increased by an order of magnitude as the initial spin polarization
degree is raised from the low-polarization limit to several percent. We perform
control experiments to decouple the excitation density in the sample from the
spin polarization degree and investigate the interplay of the internal HF field
and an external perpendicular magnetic field. The lifetime of spins oriented in
the plane of a [001]-grown 2DES is strongly anisotropic if the Rashba and
Dresselhaus spin-orbit fields are of the same order of magnitude. This
anisotropy, which stems from the interference of the Rashba and the Dresselhaus
spin-orbit fields, is highly density-dependent: as the electron density is
increased, the kubic Dresselhaus term becomes dominant and reduces the
anisotropy.


title: How reliable are bound-state parameters obtained from QCD sum rules?

abstract:
  We discuss the extraction of ground-state parameters, such as decay constants
and form factors, from two- and three-point dispersive sum rules, making use of
a quantum-mechanical potential model. This model provides a unique possibility
to probe the reliability and the accuracy of the method of sum rules: one
obtains the bound-state parameters by the standard procedures adopted in sum
rules, and compares these results with the exact values, known in the potential
model. We demonstrate the presence of uncontrollable uncertainties in the
ground-state parameters obtained from sum rules and estimate their magnitude.
The uncontrolled uncertainties in ground-state form factors are shown to be
typically much larger than those in the decay constants. In the example
presented, the uncontrolled systematic error in the extracted form factor is
found to exceed the 10% level.


title: The most energetic cosmic rays and their possible sources

abstract:
  The primary cosmic rays particles with energies above 10**20 eV have been
observed at many extensive air shower arrays since the beginning of
observations over 40 years ago. The validity of measurements of signal s(600)
used as energy estimation parameter at the Yakutsk array has been confirmed.
Our calculations show that the width of the time pulses increases from nearly
100 ns at a distance of 100 m from the shower axis up to 4 - 5 $\mu$s at 1500
m. The calculated estimate of energy of extensive air shower is ~ 1.7 times
smaller than the experimental estimate for the same value s(600). The pointing
directions of extensive air showers observed at the Pierre Auger Observatory
were fitted within +-3.1**o with positions of the nearby active galactic nuclei
from the Veron-Cetty and P. Veron catalog. The cosmic ray luminosity of the
active galactic nuclei which happened to be a source of the particular cosmic
ray event constitutes a fraction ~10**-4 of the optical one if only cosmic ray
particles with energies above 6*10**19 eV are produced. If produced cosmic ray
particles have a spectrum up to ~ 100 GeV then the cosmic ray luminosity of the
active galactic nuclei should be much higher than the optical one.


title: Marginal relevance of disorder for pinning models

abstract:
  The effect of disorder on pinning and wetting models has attracted much
attention in theoretical physics. In particular, it has been predicted on the
basis of the Harris criterion that disorder is relevant (annealed and quenched
model have different critical points and critical exponents) if the return
probability exponent alpha, a positive number that characterizes the model, is
larger than 1/2. Weak disorder has been predicted to be irrelevant (i.e.
coinciding critical points and exponents) if alpha < 1/2. Recent mathematical
work has put these predictions on firm grounds. In renormalization group terms,
the case alpha = 1/2 is a 'marginal case' and there is no agreement in the
literature as to whether one should expect disorder relevance or irrelevance at
marginality. The question is particularly intriguing also because the case
alpha = 1/2 includes the classical models of two-dimensional wetting of a rough
substrate, of pinning of directed polymers on a defect line in dimension (3+1)
or (1+1) and of pinning of an heteropolymer by a point potential in
three-dimensional space. Here we prove disorder relevance both for the general
alpha = 1/2 pinning model and for the hierarchical version of the model
proposed by B. Derrida, V. Hakim and J. Vannimenus (JSP, 1992), in the sense
that we prove a shift of the quenched critical point with respect to the
annealed one. In both cases we work with Gaussian disorder and we show that the
shift is at least of order exp(-1/\beta^4) for beta small, if beta is the
standard deviation of the disorder.


title: Nucleon form factors with dynamical twisted mass fermions

abstract:
  The electromagnetic and axial form factors of the nucleon are evaluated in
twisted mass QCD with two degenerate flavors of light, dynamical quarks. The
axial charge g_A, magnetic moment and the Dirac and Pauli radii are determined
for pion masses in the range 300 MeV to 500 MeV.


title:
Spin resolved energy parametrization of a quasi-one-dimensional electron
  gas

abstract:
  By carrying out extensive lattice regularized diffusion Monte Carlo
calculations, we study the spin and density dependence of the ground state
energy for a quasi-one-dimensional electron gas, with harmonic transverse
confinement and long-range $1/r$ interactions. We present a parametrization of
the exchange-correlation energy suitable for spin density functional
calculations, which fulfills exact low and high density limits.


title: Improved Capacity Scaling in Wireless Networks With Infrastructure

abstract:
  This paper analyzes the impact and benefits of infrastructure support in
improving the throughput scaling in networks of $n$ randomly located wireless
nodes. The infrastructure uses multi-antenna base stations (BSs), in which the
number of BSs and the number of antennas at each BS can scale at arbitrary
rates relative to $n$. Under the model, capacity scaling laws are analyzed for
both dense and extended networks. Two BS-based routing schemes are first
introduced in this study: an infrastructure-supported single-hop (ISH) routing
protocol with multiple-access uplink and broadcast downlink and an
infrastructure-supported multi-hop (IMH) routing protocol. Then, their
achievable throughput scalings are analyzed. These schemes are compared against
two conventional schemes without BSs: the multi-hop (MH) transmission and
hierarchical cooperation (HC) schemes. It is shown that a linear throughput
scaling is achieved in dense networks, as in the case without help of BSs. In
contrast, the proposed BS-based routing schemes can, under realistic network
conditions, improve the throughput scaling significantly in extended networks.
The gain comes from the following advantages of these BS-based protocols.
First, more nodes can transmit simultaneously in the proposed scheme than in
the MH scheme if the number of BSs and the number of antennas are large enough.
Second, by improving the long-distance signal-to-noise ratio (SNR), the
received signal power can be larger than that of the HC, enabling a better
throughput scaling under extended networks. Furthermore, by deriving the
corresponding information-theoretic cut-set upper bounds, it is shown under
extended networks that a combination of four schemes IMH, ISH, MH, and HC is
order-optimal in all operating regimes.


title:
The Impact of Uncertainties in Reaction Q-values on Nucleosynthesis in
  Type I X-Ray Bursts

abstract:
  Nucleosynthesis in Type I X-ray bursts may involve up to several thousand
nuclear processes. The majority of these processes have only been determined
theoretically due to the lack of sufficient experimental information. Accurate
reaction Q-values are essential for reliable theoretical estimates of
reaction-rates. Those reactions with small Q-values (< 1 MeV) are of particular
interest in these environments as they may represent waiting points for a
continuous abundance flow towards heavier-mass nuclei. To explore the nature of
these waiting points, we have performed a comprehensive series of
post-processing calculations which examine the sensitivity of nucleosynthesis
in Type I X-ray bursts to uncertainties in reaction Q-values. We discuss and
list the relatively few critical masses for which measurements could better
constrain the results of our studies. In particular, we stress the importance
of measuring the mass of 65As to obtain an experimental Q-value for the
64Ge(p,gamma)65As reaction.


title: Infinite genus surfaces and irrational polygonal billiards

abstract:
  We prove that the natural invariant surface associated with the billiard game
on an irrational polygonal table is homeomorphic to the Loch Ness monster, that
is, the only orientable infinite genus topological real surface with exactly
one end.


title: Second order hydrodynamic coefficients from kinetic theory

abstract:
  In a relativistic setting, hydrodynamic calculations which include shear
viscosity (which is first order in an expansion in gradients of the flow
velocity) are unstable and acausal unless they also include terms to second
order in gradients. To date such terms have only been computed in
supersymmetric N=4 Super-Yang-Mills theory at infinite coupling. Here we
compute these second-order hydrodynamic coefficients in weakly coupled QCD,
perturbatively to leading order in the QCD coupling, using kinetic theory. We
also compute them in QED and scalar lambda phi^4 theory.


title: Charged black holes on a Kaluza-Klein bubble

abstract:
  We construct a solution of two black holes on a Kaluza-Klein bubble in
Einstein-Maxwell-dilaton theory. We explore the consequences of the presence of
charge for the properties of this solution, and obtain a generalized Smarr
relation and first law.


title: Cognitive OFDM network sensing: a free probability approach

abstract:
  In this paper, a practical power detection scheme for OFDM terminals, based
on recent free probability tools, is proposed. The objective is for the
receiving terminal to determine the transmission power and the number of the
surrounding base stations in the network. However, thesystem dimensions of the
network model turn energy detection into an under-determined problem. The focus
of this paper is then twofold: (i) discuss the maximum amount of information
that an OFDM terminal can gather from the surrounding base stations in the
network, (ii) propose a practical solution for blind cell detection using the
free deconvolution tool. The efficiency of this solution is measured through
simulations, which show better performance than the classical power detection
methods.


title:
Singularity Structures in Coulomb-Type Potentials in Two Body Dirac
  Equations of Constraint Dynamics

abstract:
  Two Body Dirac Equations (TBDE) of Dirac's relativistic constraint dynamics
have been successfully applied to obtain a covariant nonperturbative
description of QED and QCD bound states. Coulomb-type potentials in these
applications lead naively in other approaches to singular relativistic
corrections at short distances that require the introduction of either
perturbative treatments or smoothing parameters. We examine the corresponding
singular structures in the effective potentials of the relativistic
Schroedinger equation obtained from the Pauli reduction of the TBDE. We find
that the relativistic Schroedinger equation lead in fact to well-behaved wave
function solutions when the full potential and couplings of the system are
taken into account. The most unusual case is the coupled triplet system with
S=1 and L={(J-1),(J+1)}. Without the inclusion of the tensor coupling, the
effective S-state potential would become attractively singular. We show how
including the tensor coupling is essential in order that the wave functions be
well-behaved at short distances. For example, the S-state wave function becomes
simply proportional to the D-state wave function and dips sharply to zero at
the origin, unlike the usual S-state wave functions. Furthermore, this behavior
is similar in both QED and QCD, independent of the asymptotic freedom behavior
of the assumed QCD vector potential. Light- and heavy-quark meson states can be
described well by using a simplified linear-plus-Coulomb-type QCD potential
apportioned appropriately between world scalar and vector potentials. We use
this potential to exhibit explicitly the origin of the large pi-rho splitting
and effective chiral symmetry breaking. The TBDE formalism developed here may
be used to study quarkonia in quark-gluon plasma environments.


title: Ferromagnetism and orbital order in the two-orbital Hubbard model

abstract:
  We investigate spin and orbital states of the two-orbital Hubbard model on a
square lattice by using a variational Monte Carlo method at quarter-filling,
i.e., the electron number per site is one. As a variational wave function, we
consider a Gutzwiller projected wave function of a mean-field type wave
function for a staggered spin and/or orbital ordered state. Then, we evaluate
expectation value of energy for the variational wave functions by using the
Monte Carlo method and determine the ground state. In the strong Coulomb
interaction region, the ground state is the perfect ferromagnetic state with
antiferro-orbital (AF-orbital) order. By decreasing the interaction, we find
that the disordered state becomes the ground state. Although we have also
considered the paramagnetic state with AF-orbital order, i.e., purely orbital
ordered state, and partial ferromagnetic states with and without AF-orbital
order, they do not become the ground state.


title: Width of Shape Resonances for Non Globally Analytic Potentials

abstract:
  We consider the semiclassical Schroedinger operator with a "well in an
island" potential, on which we assume smoothness only, except near infinity. We
give the asymptotic expansion of the imaginary part of the shape resonance at
the bottom of the well. This is a generalization of a result by Helffer and
Sjoestrand in the globally analytic case. We use an almost analytic extension
in order to continue the WKB solution coming from the well beyond the caustic
set, and, for the justification of the accuracy of this approximation, we
develop some refined microlocal arguments in h-dependent small regions.


title: First Study of Neutron Tagging with a Water Cherenkov Detector

abstract:
  A first study of neutron tagging is conducted in Super--Kamiokande, a
50,000-ton water Cherenkov detector. The tagging efficiencies of thermal
neutrons are evaluated in a 0.2 % GdCl$_{3}$-water solution and pure water.
They are determined to be, respectively, 66.7 % for events above 3 MeV and 20 %
with corresponding background probabilities of 2 $\times$ 10$^{-4}$ and 3
$\times$ 10$^{-2}$. This newly developed technique may enable water Cherenkov
detectors to identify $\bar \nu_{e}$'s geological or astrophysical sources as
well as those produced by commercial reactors via the delayed coincidence
scheme.


title: Single shot measurement of a silicon single electron transistor

abstract:
  We have fabricated a custom cryogenic Complementary Metal-Oxide-Semiconductor
(CMOS) integrated circuit that has a higher measurement bandwidth compared with
conventional room temperature electronics. This allowed implementing single
shot operations and observe the real-time evolution of the current of a
phosphorous-doped silicon single electron transistor that was irradiated with a
microwave pulse. Relaxation times up to 90 us are observed, suggesting the
presence of well isolated electron excitations within the device. It is
expected that these are associated with long decoherence time and the device
may be suitable for quantum information processing.


title: Decaying Dark Matter Baryons in a Composite Messenger Model

abstract:
  A baryonic bound state with a mass of O(100) TeV, which is composed of
strongly interacting messenger quarks in the low scale gauge mediation, can
naturally be the cold dark matter. Interestingly, we find that such a baryonic
dark matter is generically metastable, and the decay of this dark matter can
naturally explain the anomalous positron flux recently observed by the PAMELA
collaboration.


title: Gamma ray astrophysics: the EGRET results

abstract:
  Cosmic gamma rays provide insight into some of the most dynamic processes in
the Universe. At the dawn of a new generation of gamma-ray telescopes, this
review summarizes results from the Energetic Gamma Ray Experiment Telescope
(EGRET) on the Compton Gamma Ray Observatory, the principal predecessor mission
studying high-energy photons in the 100 MeV energy range. EGRET viewed a
gamma-ray sky dominated by prominent emission from the Milky Way, but featuring
an array of other sources, including quasars, pulsars, gamma-ray bursts, and
many sources that remain unidentified. A central feature of the EGRET results
was the high degree of variability seen in many gamma-ray sources, indicative
of the powerful forces at work in objects visible to gamma-ray telescopes.


title: Dilepton production in nucleon-nucleon collisions reexamined

abstract:
  We present a fully relativistic and gauge invariant framework for calculating
the cross sections of dilepton production in nucleon-nucleon ($NN$) collisions
which is based on the meson-exchange approximation for the $NN$ scattering
amplitudes. Predictions of our model are compared with those of other covariant
models that have been used earlier to describe this reaction. Our results are
also compared with those of the semiclassical models which are employed to get
the input elementary cross sections in the transport model calculations of the
dilepton production in nucleus-nucleus collisions. It is found that cross
sections obtained within the semiclassical and quantum mechanical models differ
noticeably from each other.


title:
The Average Number of Block Interchanges Needed to Sort A Permutation
  and a recent result of Stanley

abstract:
  We use an interesting result of probabilistic flavor concerning the product
of two permutations consisting of one cycle each to find an explicit formula
for the average number of block interchanges needed to sort a permutation of
length $n$.


title: Data Mining-based Fragmentation of XML Data Warehouses

abstract:
  With the multiplication of XML data sources, many XML data warehouse models
have been proposed to handle data heterogeneity and complexity in a way
relational data warehouses fail to achieve. However, XML-native database
systems currently suffer from limited performances, both in terms of manageable
data volume and response time. Fragmentation helps address both these issues.
Derived horizontal fragmentation is typically used in relational data
warehouses and can definitely be adapted to the XML context. However, the
number of fragments produced by classical algorithms is difficult to control.
In this paper, we propose the use of a k-means-based fragmentation approach
that allows to master the number of fragments through its $k$ parameter. We
experimentally compare its efficiency to classical derived horizontal
fragmentation algorithms adapted to XML data warehouses and show its
superiority.


title:
Quantum phase transition in a 1D transport model with boson affected
  hopping: Luttinger liquid versus charge-density-wave behavior

abstract:
  We solve a very general two-channel fermion-boson model describing charge
transport within some background medium by means of a refined pseudo-site
density matrix renormalization group (DMRG) technique. Performing a careful
finite-size scaling analysis, we determine the ground-state phase diagram and
convincingly prove that the model exhibits a metal-insulator quantum phase
transition for the half-filled band case. In order to characterize the metallic
and insulating regimes we calculate besides the local particle densities and
fermion-boson correlation functions, the kinetic energy, the charge structure
factor, the Luttinger liquid charge exponent and the single-particle excitation
gap for a one-dimensional infinite system.


title: Giant cavities, cooling and metallicity substructure in Abell 2204

abstract:
  We present results from deep Chandra and XMM-Newton observations of the
relaxed X-ray luminous galaxy cluster Abell 2204. We detect metallicity
inhomogeneities in the intracluster medium on a variety of distance scales,
from a ~12 kpc enhancement containing a few times 10^7 Msun of iron in the
centre, to a region at 400 kpc radius with an excess of a few times 10^9 Msun.
Subtracting an average surface brightness profile from the X-ray image yields
two surface brightness depressions to the north and south of the cluster. Their
morphology is similar to the cavities observed in cluster cores, but they have
radii of 240 kpc and 160 kpc and have a total enthalpy of 2x10^62 erg. If they
are fossil radio bubbles, their buoyancy timescales imply a total mechanical
heating power of 5x10^46 erg/s, the largest such bubble heating power known.
More likely, they result from the accumulation of many past bubbles.
Energetically this is more feasible, as the enthalpy of these regions could
combat X-ray cooling in this cluster to 500 kpc radius for around 2 Gyr. The
core of the cluster also contains five to seven ~4 kpc radius surface
brightness depressions that are not associated with the observed radio
emission. If they are bubbles generated by the nucleus, they are too small to
balance cooling in the core by an order of magnitude. However if the radio axis
is close to the line of sight, projection effects may mask more normal bubbles.
Using RGS spectra we detect a FeXVII line. Spectral fitting reveals
temperatures down to ~0.7 keV; the cluster therefore shows a range in X-ray
temperature of at least a factor of 15. The quantity of low temperature gas is
consistent with a mass deposition rate of 65 Msun/yr.


title:
Giant electro-thermal conductivity and spin-phonon coupling in an
  antiferromagnetic oxide

abstract:
  The application of weak electric fields (<~ 100 V/cm) is found to
dramatically enhance the lattice thermal conductivity of the antiferromagnetic
(AF) insulator CaMnO(3) over a broad range of temperature about the Neel
ordering point (125 K). The effect is coincident with field-induced de-trapping
of bound electrons, suggesting that phonon scattering associated with short-
and long-ranged AF order is suppressed in the presence of the mobilized charge.
This interplay between bound charge and spin-phonon coupling might allow for
the reversible control of spin fluctuations using weak external fields.


title: Cometary masses derived from non-gravitational forces

abstract:
  We compute masses and densities for ten periodic comets with known sizes:
1P/Halley, 2P/Encke, 6P/d'Arrest, 9P/Tempel 1, 10P/Tempel 2, 19P/Borrelly,
22P/Kopff, 46P/Wirtanen, 67P/Churyumov-Gerasimenko and 81P/Wild 2. The method
follows the one developed by Rickman and colleagues (Rickman 1986, 1989;
Rickman et al. 1987), which is based on the gas production curve and on the
change in the orbital period due to the non-gravitational force. The gas
production curve is inferred from the visual lightcurve. We found that the
computed masses cover more than three orders of magnitude: ~(0.3 - 400)*10^12
kg. The computed densities are in all cases very low (<= 0.8 g cm^-3), with an
average value of 0.4 g cm^-3, in agreement with previous results and models of
the cometary nucleus depicting it as a very porous object. The computed comet
densities turn out to be the lowest among the different populations of solar
system minor bodies, in particular as compared to those of near-Earth asteroids
(NEAs). We conclude that the model applied in this work, in spite of its
simplicity (as compared to more sophisticated thermophysical models applied to
very few comets), is useful for a statistical approach to the mean density of
the cometary nuclei. However, we cannot assess from this simple model if there
is a real dispersion among the bulk densities of comets that could tell us
about differences in physical structure (porosity) and/or chemical composition.


title: Elucidating Jet Energy Loss in Heavy Ion Collisions

abstract:
  Very soon the LHC will provide beams for heavy ion collisions at 5.52
TeV/nucleon. This center-of-mass energy results in a large cross-section for
producing high-$E_T$ ($>$ 50 GeV) jets that are distinct from the soft,
underlying event. This brings with it the possibility of performing full jet
reconstruction to directly study jet energy loss in the medium produced in
heavy ion collisions. In this note, we present the current state of jet
reconstruction performance studies in heavy ion events using the ATLAS
detector. We also discuss the possibilities of energy loss measurements
available with full jet reconstruction: single jet $R_{AA}$ and di-jet and
$\gamma$-jet correlations.


title:
On the dimension of the minimal vertex covers semigroup ring of an
  unmixed bipartite graph

abstract:
  In a paper in 2008, Herzog, Hibi and Ohsugi introduced and studied the
semigroup ring associated to the set of minimal vertex covers of an unmixed
bipartite graph. In this paper we relate the dimension of this semigroup ring
to the rank of the Boolean lattice associated to the graph.


title:
Some equivalences between the auxiliary field method and the envelope
  theory

abstract:
  The auxiliary field method has been recently proposed as an efficient
technique to compute analytical approximate solutions of eigenequations in
quantum mechanics. We show that the auxiliary field method is completely
equivalent to the envelope theory, which is another well-known procedure to
analytically solve eigenequations, although relying on different principles
\textit{a priori}. This equivalence leads to a deeper understanding of both
frameworks.


title:
Echo of the Quantum Phase Transition of CeCu$_{6-x}$Au$_x$ in XPS:
  Breakdown of Kondo Screening

abstract:
  We present an X-ray photoemission study of the heavy-fermion system
CeCu$_{6-x}$Au$_x$ across the magnetic quantum phase transition of this
compound at temperatures above the single-ion Kondo temperature $T_K$. In
dependence of the Au concentration $x$ we observe a sudden change of the
$f$-occupation number $n_f$ and the core-hole potential $U_{df}$ at the
critical concentration $x_c=0.1$. We interpret these findings in the framework
of the single-impurity Anderson model. Our results are in excellent agreement
with findings from earlier UPS measurements %\cite{klein08qpt} and provide
further information about the precursors of quantum criticality at elevated
temperatures.


title:
R-matrix inner-shell electron-impact excitation of Fe$^{15+}$ including
  Auger-plus-radiation damping

abstract:
  We present results for the inner-shell electron-impact excitation of
Fe$^{15+}$ using the intermediate-coupling frame transformation {\it R}-matrix
approach in which Auger-plus-radiation damping has been included. The target
and close-coupling expansions are both taken to be the 134 levels belonging to
the configurations ${\rm 2s^22p^63}l$, ${\rm 2s^22p^53s3}l$, ${\rm
2s^22p^53p^2}$ and ${\rm 2s^22p^53p3d}$. The comparison of Maxwell-averaged
effective collision strengths with and without damping shows that the damping
reduction is about 30-40% for many transitions at low temperatures, but up to
80% for a few transitions. As a consequence, the results of previous Dirac
$R$-matrix calculations (Aggarwal and Keenan, 2008) overestimate the effective
collision strengths due to their omission of Auger-plus-radiation damping.


title: Parabolic subgroups of Garside groups II: ribbons

abstract:
  We introduce and investigate the ribbon groupoid associated with a Garside
group. Under a technical hypothesis, we prove that this category is a Garside
groupoid. We decompose this groupoid into a semi-direct product of two of its
parabolic subgroupoids and provide a groupoid presentation. In order to
established the latter result, we describe quasi-centralizers in Garside
groups. All results hold in the particular case of Artin-Tits groups of
spherical type.


title:
The Pierre Auger Observatory - a new stage in the study of the
  ultra-high energy cosmic rays

abstract:
  This paper presents the highlights from the recent measurements of the energy
spectrum, mass composition, and arrival directions of the ultra-high energy ($>
10^{17}$ eV = 0.1 EeV) cosmic rays (UHECR) by the Pierre Auger Observatory. The
Auger hybrid detector combines fluorescence observations of the longitudinal
profiles of extended air showers, initiated by these extremely energetic
particles, with measures of the shower secondaries at the ground level by its
large array of Cherenkov water tanks. The complementariness of the two
techniques provides important cross-checks at the energies unreachable with
accelerator experiments. The Pierre Auger experiment has observed a strong
steepening of the cosmic ray flux above 40 EeV. A significant anisotropy in the
arrival directions of cosmic rays has been established for events above $\simeq
60$ EeV. These events correlate over angular scales of less than 6$^\circ$ with
the directions towards nearby ($D < 100$ Mpc) active galactic nuclei. Both
observations are consistent with the standard scenarios of the UHECR production
in the extragalactic astrophysical acceleration sites. The derived stringent
upper limits on the photon and neutrino contents in the UHECR are additional
important arguments in support of these scenarios. The measurements of the
variation of the depth of shower maximum with energy, interpreted with the
current hadronic interaction models, favour the mixed cosmic ray composition at
energies above 0.4 EeV. We describe the plans and prospects for the future,
that will further help to solve the 50 years old UHECR puzzle.


title: An elementary approach to extreme values theory

abstract:
  This note presents a rather intuitive approach to extreme value theory. This
approach was devised mostly for pedagogical reason.


title: Images of the Polar maps for Hypersurfaces

abstract:
  For a projective hypersurface $X \subset \P^n$, the images of the polar maps
of degree $k$ are studied. The cohomology class defined by these maps is
calculated and classical results on dual varieties are presented as
applications.