title: Diffractive Vector Meson Photoproduction from Dual String Theory

abstract:
  We study diffractive vector meson photoproduction using string theory via
AdS/CFT. The large $s$ behavior of the cross sections for the scattering of the
vector meson $V$ on a proton is dominated by the soft Pomeron, $\sigma_V\sim
s^{2\epsilon-2\alpha'_P/B}$, where from the string theory model of
\cite{nastase2}, $\epsilon$ is approximately 1/7 below 10 GeV, and 1/11 for
higher, but still sub-Froissart, energies. This is due to the production of
black holes in the dual gravity. In $\phi$-photoproduction the mesonic Regge
poles do not contribute, so that we deal with a pure Pomeron contribution. This
allows for an experimental test. At the gauge theory "Planck scale" of about
1-2 GeV, the ratios of the soft Pomeron contributions to the photoproduction
cross-sections of different vector mesons involve not only the obvious quark
model factors, but also the Boltzmann factors $e^{-4 M_V/T_0}$, with $T_0$ the
temperature of the dual black hole. The presence of these factors is confirmed
in the experimental data for $\rho, \omega, \phi, J/\psi,$ and $\psi(2S)$
photoproduction and is compatible with the meager $\Upsilon$ photoproduction
data. Throughout, we use vector meson dominance, and from the data we obtain
$T_0$ of about $1.3 GeV$, i.e. the gauge theory "Planck scale," as expected.
The ratio of the experimental soft Pomeron onset scale $\hat{E}_R\sim 9$ GeV
and of the gauge theory Planck scale, $T_0 \sim 1.3$ GeV conforms to the
theoretical prediction of $N_c^2/N_c^{1/4}$.


title: Timing and Spectral Study of AX J1745.6-2901 with Suzaku

abstract:
  The eclipsing low-mass X-ray binary AX J1745.6-2901 was observed with Suzaku
in its outburst phase. Combining the Chandra observation made 1.5 month earlier
than Suzaku, we determined the orbital period to be 30063.76+/-0.14 s. We found
deep flux dips prior to the eclipse phase of orbit. The X-ray spectrum of the
persistent phase is described with a combination of a direct and a scattered-in
by dust emissions. During the eclipse, the X-ray spectrum becomes only the dust
scattering (scattered-in) component. The optical depth of the dust-scattering
is ~10.5 at 1 keV. The direct component is composed of a blackbody likely from
the neutron star surface and a disk-blackbody. No power-law component is found
in the hard energy band up to 30 keV. A clear edge at ~7.1 keV in the deep dip
spectrum indicates that the major portion of Fe in the absorber is neutral or
at low ionization state. We discovered four narrow absorption lines near the
K-shell transition energies of Fe XXV, Fe XXVI, and Ni XXVII. The absorption
line features are well explained by the solar abundance gas in a bulk motion of
~10^3 km/s.


title:
Lehmann-Symanzik-Zimmermann Reduction Approach to Multi-Photon
  Scattering in Coupled-Resonator Arrays

abstract:
  We present a quantum field theoretical approach based on the
Lehmann-Symanzik-Zimmermann reduction for the multi-photon scattering process
in a nano-architecture consisting of the coupled resonator arrays (CRA), which
are also coupled to some artificial atoms as the controlling quantum node. By
making use of this approach, we find the bound states of single photon for an
elementary unit, the T-type CRA, and explicitly obtain its multi-photon
scattering S-matrix in various situations. We also use this method to calculate
the multi-photon S-matrices for the more complex quantum network constructed
with main T-type CRA's, such as a H-type CRA waveguide.


title:
A massive binary black-hole system in OJ287 and a test of general
  relativity

abstract:
  Tests of Einstein's general theory of relativity have mostly been carried out
in weak gravitational fields where the space-time curvature effects are
first-order deviations from Newton's theory. Binary pulsars provide a means of
probing the strong gravitational field around a neutron star, but strong-field
effects may be best tested in systems containing black holes. Here we report
such a test in a close binary system of two candidate black holes in the quasar
OJ287. This quasar shows quasi-periodic optical outbursts at 12 yr intervals,
with two outburst peaks per interval. The latest outburst occurred in September
2007, within a day of the time predicted by the binary black-hole model and
general relativity. The observations confirm the binary nature of the system
and also provide evidence for the loss of orbital energy in agreement (within
10 per cent) with the emission of gravitational waves from the system. In the
absence of gravitational wave emission the outburst would have happened twenty
days later.


title:
MultiResolution Anomaly Detection Method for Long Range Dependent Time
  Series

abstract:
  Driven by network intrusion detection, we propose a MultiResolution Anomaly
Detection (MRAD) method, which effectively utilizes the multiscale properties
of Internet features and network anomalies. In this paper, several theoretical
properties of the MRAD method are explored. A major new result is the
mathematical formulation of the notion that a two-scaled MRAD method has larger
power than the average power of the detection method based on the given two
scales. Test threshold is also developed. Comparisons between MRAD method and
other classical outlier detectors in time series are reported as well.


title:
Quantum gravity: a solution for current problems in cosmology and
  particle physics

abstract:
  We propose a new phenomenological model for quantum gravity. This is based on
a new interpretation in which quantum gravity is not an interaction, rather it
is just responsible for generation of space-time-matter. Then we show this
model is capable of solving the important problems of cosmology and particle
physics.


title:
High Energy Emission from Rotation-Powered Pulsars: Outer-gap vs.
  Slot-gap Models

abstract:
  We explore particle accelerator electrodynamics in the magnetosphere of a
rapidly rotating neutron star (NS). We address the importance of a
self-consistent treatment of pair production, solving the Poisson equation
describing the acceleration electric field, the Boltzmann equations for
produced electrons and positrons, and the radiative transfer equation
simultaneously. It is demonstrated that the accelerator solution is obtained if
we only specify the NS spin period, magnetic dipole moment, magnetic
inclination angle with respect to the rotation axis, and the NS surface
temperature, and that the solution corresponds to a quantitative extension of
previous outer-gap models. We apply the scheme to the Crab pulsar and show that
the predicted pulse profiles and phase-resolved spectrum are roughly consistent
with observations. Applying the same scheme to the slot-gap model, we show that
this alternative model predicts too small photon flux to reproduce
observations, because the gap trans-field thickness is significantly restricted
by its pair-free condition.


title: Thin accretion disks onto brane world black holes

abstract:
  The braneworld description of our universe entails a large extra dimension
and a fundamental scale of gravity that might be lower by several orders of
magnitude as compared to the Planck scale. An interesting consequence of the
braneworld scenario is in the nature of the vacuum solutions of the brane
gravitational field equations, with properties quite distinct as compared to
the standard black hole solutions of general relativity. One possibility of
observationally discriminating between different types of black holes is the
study of the emission properties of the accretion disks. In the present paper
we obtain the energy flux, the emission spectrum and accretion efficiency from
the accretion disks around several classes of static and rotating brane world
black holes, and we compare them to the general relativistic case. Particular
signatures can appear in the electromagnetic spectrum, thus leading to the
possibility of directly testing extra-dimensional physical models by using
astrophysical observations of the emission spectra from accretion disks.


title: Resonance energy of the barKNN-piYN system

abstract:
  The resonance energies of strange dibaryons are investigated with the use of
the \bar{K}NN-\pi Y N coupled-channels Faddeev equation. It is found that the
pole positions of the predicted three-body amplitudes are significantly
modified when the three-body coupled-channels dynamics is approximated, as is
done in the literature, by the effective two-body \bar{K}N interactions.


title:
Losses in Superconductors under Non-Sinusoidal Currents and Magnetic
  Fields

abstract:
  Study of AC losses in superconducting wires and tapes is usually restricted
by consideration of applied sinusoidal currents and/or magnetic fields.
However, currents in electric power systems contain a wide variety of
harmonics. The currents become strongly non-sinusoidal at the operation of
converters, non-linear reactors, and during transient and overload conditions.
We report the results of the analysis of the influence of higher harmonics of
the current and magnetic field on AC losses in superconducting slabs, strips
and coated conductors. Analytical expressions are obtained in the framework of
Bean's critical state model; the power law voltage-current characteristics are
treated numerically. It is shown that the contribution of higher harmonics to
AC losses in superconducting elements can be tens times larger than in normal
metals and the 5% harmonic can increases the losses by up to 20%.


title: Onsager reciprocity in premelting solids

abstract:
  The diffusive motion of colloidal particles dispersed in a premelting solid
is analyzed within the framework of irreversible thermodynamics. We determine
the mass diffusion coefficient, thermal diffusion coefficient and Soret
coefficient of the particles in the dilute limit, and find good agreement with
experimental data. In contrast to liquid suspensions, the unique nature of
premelting solids allows us to derive an expression for the Dufour coefficient
and independently verify the Onsager reciprocal relation coupling diffusion to
the flow of heat.


title:
Strong uniqueness for a class of singular SDEs for catalytic branching
  diffusions

abstract:
  A new result for the strong uniqueness for catalytic branching diffusions is
established, which improves the work of Dawson, D.A.; Fleischmann, K.; Xiong,
J.[Strong uniqueness for cyclically symbiotic branching diffusions. Statist.
Probab. Lett. 73, no. 3, 251--257 (2005)].


title:
Renormalization group in the infinite-dimensional turbulence:
  third-order results

abstract:
  The field theoretic renormalization group is applied to the stochastic
Navier-Stokes equation with the stirring force correlator of the form
k^(4-d-2\epsilon) in the d-dimensional space, in connection with the problem of
construction of the 1/d expansion for the fully developed fluid turbulence
beyond the scope of the standard epsilon expansion. It is shown that in the
large-d limit the number of the Feynman diagrams for the Green function (linear
response function) decreases drastically, and the technique of their analytical
calculation is developed. The main ingredients of the renormalization group
approach -- the renormalization constant, beta function and the ultraviolet
correction exponent omega, are calculated to order epsilon^3 (three-loop
approximation). The two-point velocity-velocity correlation function, the
Kolmogorov constant C_K in the spectrum of turbulent energy and the
inertial-range skewness factor S are calculated in the large-d limit to third
order of the epsilon expansion. Surprisingly enough, our results for C_K are in
a reasonable agreement with the existing experimental estimates.


title: Generalized Schmidt decomposition based on injective tensor norm

abstract:
  We present a generalized Schmidt decomposition for a pure system with any
number of two-level subsystems. The basis is symmetric under the permutation of
the parties and is derived from the product state defining the injective tensor
norm of the state. The largest coefficient quantifies the quantum correlation
of the state. Other coefficients have a lot of information such as the
unentangled particles as well as the particles whose reduced states are
completely mixed. The decomposition clearly distinguishes the states entangled
in inequivalent ways and have an information on the applicability to the
teleportation and superdense coding when the given quantum state is used as a
quantum channel.


title:
Di-neutron correlation in soft octupole excitations of neutron-rich Ni
  isotopes beyond N=50

abstract:
  We investigate low-lying octupole response of neutron-rich Ni isotopes beyond
the N=50 shell closure using the Skyrme-Hartree-Fock-Bogoliubov mean-fields and
the continuum quasi-particle random phase approximation. Performing detailed
numerical analyses employing the Skyrme parameter set SLy4 and a
density-dependent delta interaction of the mixed type, we show that a neutron
mode emerges above the neutron separation energy as a consequence of the weak
binding of neutrons and it exhibits strong influences of the di-neutron
correlation.


title:
Polarization of the Crab pulsar and nebula as observed by the
  Integral/IBIS telescope

abstract:
  Neutron stars generate powerful winds of relativistic particles that form
bright synchrotron nebulae around them. Polarimetry provides a unique insight
into the geometry and magnetic configuration of the wind, but high-energy
measurements have failed until recently. The Integral-IBIS telescope has been
used in its Compton mode to search for linearly polarized emission for energies
above 200 keV from the Crab nebula. The asymmetries in the instrument response
are small and we obtain evidences for a strongly polarized signal at an angle
parallel to the pulsar rotation axis. This result confirms the detection
recently reported by Dean et al. (2008), and extends the polarization measure
for all the pulsar's phases. The hard X-ray/soft $\gamma$-ray observations
therefore probe the inner jets or equatorial flow of the wind. The achieved
sensitivity opens a new window for polarimetric studies at energies above 200
keV.


title: AC conductivity of a quantum Hall line junction

abstract:
  We present a microscopic model for calculating the AC conductivity of a
finite length line junction made up of two counter or co-propagating single
mode quantum Hall edges with possibly different filling fractions. The effect
of density-density interactions and the tunneling conductance (\sigma), between
the two edges, is considered, and exact expressions are derived for the AC
conductivity as a function of the frequency (\omega), the length of the line
junction and other parameters of the system. We reproduce the results of Phys.
Rev. B 78, 085430 (2008) in the DC limit (\omega \to 0), and generalize those
results for an interacting system. As a function of \omega, the AC conductivity
shows significant oscillations if \sigma is small; the oscillations become less
prominent as \sigma increases. A renormalization group analysis shows that the
system may be in a metallic or an insulating phase depending on the strength of
the interactions. We discuss the experimental implications of this for the
behavior of the AC conductivity at low temperatures.


title: On the TFD treatment of collective vibrations in hot nuclei

abstract:
  The approach in a theory of collective excitations in hot nuclei exploring
the formalism of thermo field dynamics and the model Hamiltonian consisting of
a mean field, the BCS paring interaction and long-range particle-hole effective
forces is reexamined. In contrast with earlier studies it is found that a wave
function of a thermal phonon is depended not only on the Fermi-Dirac thermal
occupation numbers of Bogoliubov quasiparticles consisting the phonon but on
the Bose thermal occupation numbers of the phonon as well. This strongly
affects a thermal phonon couplings due to renormalizing of a phonon-phonon
interaction and enlarging the number of thermal two-phonon configurations
coupled with one-phonon ones. Moreover, it is shown that the formulation of the
double tilde conjugation rule for fermions proposed by I.Ojima is more
appropriate in the context of the present study than the original one by
H.Umezawa and coworkers.


title:
Improvement of the Determination of the WIMP Mass from Direct Dark
  Matter Detection Data

abstract:
  Weakly Interacting Massive Particles (WIMPs) are one of the leading
candidates for Dark Matter. We developed a model-independent method for
determining the WIMP mass by using data (i.e., measured recoil energies) of
direct detection experiments. Our method is independent of the as yet unknown
WIMP density near the Earth, of the form of the WIMP velocity distribution, as
well as of the WIMP-nucleus cross section. It requires however positive signals
from at least two detectors with different target nuclei. At the first phase of
this work we found a systematic deviation of the reconstructed WIMP mass from
the real one for heavy WIMPs. Now we improved this method so that this
deviation can be strongly reduced for even very high WIMP mass. The statistical
error of the reconstructed mass has also been reduced. In a background-free
evironment, a WIMP mass of ~ 50 GeV could in principle be determined with an
error of ~ 35% with only 2 times 50 events.


title:
Interplay between quantum dissipation and an in-plane magnetic field in
  the spin ratchet effect

abstract:
  We investigate the existence of the pure spin ratchet effect in a dissipative
quasi-one-dimensional system with Rashba spin-orbit interaction. The system is
additionally placed into a transverse uniform stationary in-plane magnetic
field. It is shown that the effect exists at low temperatures and pure spin
currents can be generated by applying an unbiased ac driving to the system. An
analytical expression for the ratchet spin current is derived. From this
expression it follows that the spin ratchet effect appears as a result of the
simultaneous presence of the spin-orbit interaction, coupling between the
orbital degrees of freedom and spatial asymmetry. In this paper we consider the
case of a broken spatial symmetry by virtue of asymmetric periodic potentials.
It turns out that an external magnetic field does not have any impact on the
existence of the spin ratchet effect, but it influences its efficiency
enhancing or reducing the magnitude of the spin current.


title:
Response to Comment on "Combined open shell Hartree-Fock theory of
  atomic-molecular and nuclear systems" [I.I.Guseinov, J. Math. Chem., 42
  (2007) 177] by B. N. Plakhutin and E. R. Davidson

abstract:
  This article is a thorough critique to the Plakhutin-Davidson's comments made
to our paper published in the recent year. A detailed critical examination of
the arguments that led to the suggested comments by Plakhutin and Davidson
reveals some serious flaws. It is demonstrated that the principle of the
indistinguishability of identical particles is not taking into account in
Roothaan's open shell theory. This principle leads to the fact that the
orbital-dependent energy functional and, therefore, the Hartree-Fock and
Hartree-Fock-Roothaan equations for open shell systems presented by Roothaan
and others are not, in general, invariant under unitary transformation of the
combined closed-open shells orbitals. From a mathematical point of view this
statement is fundamentally flawless. It is shown that the Plakhutin-Davidson's
personal views about our assumptions concerning the insufficiencies of classic
Roothaan's open-shell theory are undisputedly wrong.


title: Submanifolds with Biharmonic Gauss Map

abstract:
  We generalize the Ruh-Vilms problem by characterizing the submanifolds in
Euclidean spaces with proper biharmonic Gauss map and we construct examples of
such hypersurfaces.


title: Electronic inhomogeneity in EuO: Possibility of magnetic polaron states

abstract:
  We have observed the spatial inhomogeneity of the electronic structure of a
single-crystalline electron-doped EuO thin film with ferromagnetic ordering by
employing infrared magneto-optical imaging with synchrotron radiation. The
uniform paramagnetic electronic structure changes to a uniform ferromagnetic
structure via an inhomogeneous state with decreasing temperature and increasing
magnetic field slightly above the ordering temperature. One possibility of the
origin of the inhomogeneity is the appearance of magnetic polaron states.


title: What makes a good role model

abstract:
  The role model strategy is introduced as a method for designing an estimator
by approaching the output of a superior estimator that has better input
observations. This strategy is shown to yield the optimal Bayesian estimator
when a Markov condition is fulfilled. Two examples involving simple channels
are given to illustrate its use. The strategy is combined with time averaging
to construct a statistical model by numerically solving a convex program. The
role model strategy was developed in the context of low complexity decoder
design for iterative decoding. Potential applications outside the field of
communications are discussed.


title:
NLO Electroweak Corrections to Higgs Boson Production at Hadron
  Colliders

abstract:
  Results for the complete NLO electroweak corrections to Standard Model Higgs
production via gluon fusion are included in the total cross section for
hadronic collisions. Artificially large threshold effects are avoided working
in the complex-mass scheme. The numerical impact at LHC (Tevatron) energies is
explored for Higgs mass values up to 500 GeV (200 GeV). Assuming a complete
factorization of the electroweak corrections, one finds a +5 % shift with
respect to the NNLO QCD cross section for a Higgs mass of 120 GeV both at the
LHC and the Tevatron. Adopting two different factorization schemes for the
electroweak effects, an estimate of the corresponding total theoretical
uncertainty is computed.


title: Two-Loop Threshold Singularities, Unstable Particles and Complex Masses

abstract:
  The effect of threshold singularities induced by unstable particles on
two-loop observables is investigated and it is shown how to cure them working
in the complex-mass scheme. The impact on radiative corrections around
thresholds is thoroughly analyzed and shown to be relevant for two selected LHC
and ILC applications: Higgs production via gluon fusion and decay into two
photons at two loops in the Standard Model. Concerning Higgs production, it is
essential to understand possible sources of large corrections in addition to
the well-known QCD effects. It is shown that NLO electroweak corrections can
incongruently reach a 10 % level around the WW vector-boson threshold without a
complete implementation of the complex-mass scheme in the two-loop calculation.


title:
Current conservation, screening and the magnetic moment of the $\Delta$
  resonance: 2. Formulation with quark degrees of freedom 3. Magnetic moment of
  the $\Delta^o$ and $\Delta^-$ resonances

abstract:
  Our previous paper \cite{MFNEW} is generalized within the field theoretical
formulation with the quark degrees of freedom \cite{HW,H,N,Z}, where pions and
nucleons are treated as the bound systems of quarks. It is shown that relations
generated by current conservation for the on shell $\pi N$ bremsstrahlung
amplitude with composite nucleons and pions have the same form as in the usual
quantum field theory \cite{IZ,BD} without quark degrees of freedom
\cite{MFNEW}. Consequently, the model independent relations for the magnetic
dipole moments of the $\Delta^+$ and $\Delta^{++}$ resonances in \cite{MFNEW}
remain be the same in the quantum field theory with the quark degrees of
freedom. These relations are extended for the magnetic dipole moments of the
$\Delta^o$ and $\Delta^-$ resonances which are determined via the anomalous
magnetic moment of the neutron $\mu_n$ as $\mu_{\Delta^o}={{M_{\Delta}}\over
{m_p}} \mu_n$ and $\mu_{\Delta^{-}}={3\over 2}\mu_{\Delta^o}$.


title:
Boltzmann's H-theorem, its limitations, and the birth of (fully)
  statistical mechanics

abstract:
  A comparison is made of the traditional Loschmidt (reversibility) and Zermelo
(recurrence) objections to Boltzmann's H-theorem, and its simplified variant in
the Ehrenfests' 1912 wind-tree model. The little-cited 1896 (pre-recurrence)
objection of Zermelo (similar to an 1889 argument due to Poincare) is also
analysed. Significant differences between the objections are highlighted, and
several old and modern misconceptions concerning both them and the H-theorem
are clarified. We give particular emphasis to the radical nature of Poincare's
and Zermelo's attack, and the importance of the shift in Boltzmann's thinking
in response to the objections as a whole.


title: Semistar-Krull and Valuative Dimension of Integral Domains

abstract:
  Given a stable semistar operation of finite type $\star$ on an integral
domain $D$, we show that it is possible to define in a canonical way a stable
semistar operation of finite type $\star[X]$ on the polynomial ring $D[X]$,
such that, if $n:=\star$-$\dim(D)$, then $n+1\leq
\star[X]\text{-}\dim(D[X])\leq 2n+1$. We also establish that if $D$ is a
$\star$-Noetherian domain or is a Pr\"{u}fer $\star$-multiplication domain,
then $\star[X]\text{-}\dim(D[X])=\star\text{-}\dim(D)+1$. Moreover we define
the semistar valuative dimension of the domain $D$, denoted by
$\star$-$\dim_v(D)$, to be the maximal rank of the $\star$-valuation overrings
of $D$. We show that $\star$-$\dim_v(D)=n$ if and only if
$\star[X_1,...,X_n]$-$\dim_v(D[X_1,...,X_n])=2n$, and that if
$\star$-$\dim_v(D)<\infty$ then $\star[X]$-$\dim_v(D[X])=\star$-$\dim_v(D)+1$.
In general $\star$-$\dim(D)\leq\star$-$\dim_v(D)$ and equality holds if $D$ is
a $\star$-Noetherian domain or is a Pr\"{u}fer $\star$-multiplication domain.
We define the $\star$-Jaffard domains as domains $D$ such that
$\star$-$\dim(D)<\infty$ and $\star$-$\dim(D)=\star$-$\dim_v(D)$. As an
application, $\star$-quasi-Pr\"{u}fer domains are characterized as domains $D$
such that each $(\star,\star')$-linked overring $T$ of $D$, is a
$\star'$-Jaffard domain, where $\star'$ is a stable semistar operation of
finite type on $T$. As a consequence of this result we obtain that a Krull
domain $D$, must be a $w_D$-Jaffard domain.


title:
Excitonic Instability in the Transition from the Black Phase to the
  Golden Phase of SmS under Pressure Investigated by Infrared Spectroscopy

abstract:
  We report the pressure-dependent optical reflectivity spectra of a strongly
correlated insulator, samarium monosulfide (SmS), in the far- and
middle-infrared regions to investigate the origin of the pressure-induced phase
transition from the black phase to the golden phase. The energy gap becomes
narrow with increasing pressure in the black phase. A valence transition from
Sm2+ in the black phase to mainly Sm3+ in the golden phase accompanied by
spectral change from insulator to metal were observed at the transition
pressure of 0.65 GPa. The black-to-golden phase transition occurs when the
energy gap size of black SmS becomes the same as the binding energy of the
exciton at the indirect energy gap before the gap closes. This result indicates
that the valence transition originates from an excitonic instability.


title: Minimal Prime Ideals and Semistar Operations

abstract:
  Let $R$ be a commutative integral domain and let $\star$ be a semistar
operation of finite type on $R$, and $I$ be a quasi-$\star$-ideal of $R$. We
show that, if every minimal prime ideal of $I$ is the radical of a
$\star$-finite ideal, then the set $\Min(I)$ of minimal prime ideals over $I$
is finite.


title:
Graph-theoretic criteria for injectivity and unique equilibria in
  general chemical reaction systems

abstract:
  In this paper we discuss the question of how to decide when a general
chemical reaction system is incapable of admitting multiple equilibria,
regardless of parameter values such as reaction rate constants, and regardless
of the type of chemical kinetics, such as mass-action kinetics,
Michaelis-Menten kinetics, etc. Our results relate previously described linear
algebraic and graph-theoretic conditions for injectivity of chemical reaction
systems. After developing a translation between the two formalisms, we show
that a graph-theoretic test developed earlier in the context of systems with
mass action kinetics, can be applied to reaction systems with arbitrary
kinetics. The test, which is easy to implement algorithmically, and can often
be decided without the need for any computation, rules out the possibility of
multiple equilibria for the systems in question.


title:
Bernoulli correction to viscous losses. Radial flow between two parallel
  discs

abstract:
  For a massless fluid (density = 0), the steady flow along a duct is governed
exclusively by viscous losses. In this paper, we show that the velocity profile
obtained in this limit can be used to calculate the pressure drop up to the
first order in density. This method has been applied to the particular case of
a duct, defined by two plane-parallel discs. For this case, the first-order
approximation results in a simple analytical solution which has been favorably
checked against numerical simulations. Finally, an experiment has been carried
out with water flowing between the discs. The experimental results show good
agreement with the approximate solution.


title: Well-posedness of the transport equation by stochastic perturbation

abstract:
  We consider the linear transport equation with a globally Holder continuous
and bounded vector field. While this deterministic PDE may not be well-posed,
we prove that a multiplicative stochastic perturbation of Brownian type is
enough to render the equation well-posed. This seems to be the first explicit
example of partial differential equation that become well-posed under the
influece of noise. The key tool is a differentiable stochastic flow constructed
and analysed by means of a special transformation of the drift of Ito-Tanaka
type.


title:
Modified f(R) gravity from scalar-tensor theory and inhomogeneous EoS
  dark energy

abstract:
  The reconstruction of f(R)-gravity is showed by using an auxiliary scalar
field in the context of cosmological evolution, this development provide a way
of reconstruct the form of the function f (R) for a given evolution of the
Hubble parameter. In analogy, f(R)-gravity may be expressed by a perfect fluid
with an inhomogeneous equation of state that depends on the Hubble parameter
and its derivatives. This mathematical equivalence that may confuse about the
origin of the mechanism that produces the current acceleration, and possibly
the whole evolution of the Hubble parameter, is shown here.


title: A class of iterative methods for solving nonlinear operator equations

abstract:
  The article deals with gradient-like iterative methods for solving nonlinear
operator equations on Hilbert and Banach spaces. The authors formulate a
general principle of studying such methods. This principle allows to formulate
simple conditions of convergence of the method under consideration, to estimate
the rate of this convergence and to give effective a priori and aposteriori
error estimates in terms of a scalar function that is constructed on the base
of estimates for properties of invertibility and smoothness of linearizations
of the left-hand side of the equations under study. The principle is applicable
for analysis of such classical methods as method of minimal residuals, method
of steepest descent, method of minimal errors and others. The main results are
obtained for operator equations on Hilbert spaces and Banach spaces with a
special property, that is called Bynum property.


title:
Continuous Time Random Walks with Internal Dynamics and Subdiffusive
  Reaction-Diffusion Equations

abstract:
  We formulate the generalized master equation for a class of continuous time
random walks in the presence of a prescribed deterministic evolution between
successive transitions. This formulation is exemplified by means of an
advection-diffusion and a jump-diffusion scheme. Based on this master equation,
we also derive reaction-diffusion equations for subdiffusive chemical species,
using a mean field approximation.


title:
Muon decays in the Earth's atmosphere, differential aging and the
  paradox of the twins

abstract:
  Observation of the decay of muons produced in the Earth's atmosphere by
cosmic ray interactions provides a graphic illustration of the
counter-intuitive space-time predictions of special relativity theory. Muons at
rest in the atmosphere, decaying simultaneously, are subject to a universal
time-dilatation effect when viewed from a moving frame and so are also observed
to decay simultaneously in all such frames. The analysis of this example
reveals the underlying physics of the differential aging effect in Langevin's
travelling-twin thought experiment.


title: New results on gauge-invariant TMD PDFs in QCD

abstract:
  The renormalization properties of unintegrated (transverse-momentum
dependent) parton distribution functions (TMD PDF's) are used for analyzing
their completely gauge-invariant definition. To this end, the UV anomalous
dimension is calculated at the one-loop order in the light-cone gauge and a
consistent treatment of the extra singularities, which produce undesirable
contributions in the anomalous dimensions, is given. The generalized definition
of a TMD PDF, based on the renormalization procedure for the Wilson
exponentials with obstructions, is proposed. The reduction of the re-defined
TMD PDF to the integrated PDF's, as well as their probabilistic interpretation,
are discussed.


title:
Quantification of the bond-angle dispersion by Raman spectroscopy and
  the strain energy of amorphous silicon

abstract:
  A thorough critical analysis of the theoretical relationships between the
bond-angle dispersion in a-Si and the width of the transverse optical (TO)
Raman peak is presented. It is shown that the discrepancies between them are
drastically reduced when unified definitions for these magnitudes are used.
This reduced dispersion in the predicted values of the bond-angle dispersion
together with the broad agreement with its scarce direct determinations is then
used to analyze the strain energy in partially relaxed pure a-Si. It is
concluded that defect annihilation does not contribute appreciably to reducing
the a-Si energy during structural relaxation. In contrast, it can account for
half of the crystallization energy, which can be as low as 7 kJ/mol in
defect-free a-Si.


title: Quantum spin Hall effect in a transition metal oxide Na2IrO3

abstract:
  We study theoretically the electronic states in a $5d$ transition metal oxide
Na$_2$IrO$_3$, in which both the spin-orbit interaction and the electron
correlation play crucial roles. Tight-binding model analysis together with the
fisrt-principles band structure calculation predicts that this material is a
layered quantum spin Hall system. Due to the electron correlation, an
antiferromagnetic order first develops at the edge, and later inside the bulk
at low temperatures.


title: A Fuzzy Commitment Scheme

abstract:
  This paper attempt has been made to explain a fuzzy commitment scheme. In the
conventional Commitment schemes, both committed string m and valid opening key
are required to enable the sender to prove the commitment. However there could
be many instances where the transmission involves noise or minor errors arising
purely because of the factors over which neither the sender nor the receiver
have any control. The fuzzy commitment scheme presented in this paper is to
accept the opening key that is close to the original one in suitable distance
metric, but not necessarily identical. The concept itself is illustrated with
the help of simple situation.


title:
Totally geodesic submanifolds of the exceptional Riemannian symmetric
  spaces of rank 2

abstract:
  The present article is the final part of a series on the classification of
the totally geodesic submanifolds of the irreducible Riemannian symmetric
spaces of rank 2. After this problem has been solved for the 2-Grassmannians in
my previous papers cited in the present paper as [K1] and [K2], and for the
space SU(3)/SO(3) in [K3], Section 6, we now solve the classification for the
remaining irreducible Riemannian symmetric spaces of rank 2 and compact type:
SU(6)/Sp(3), SO(10)/U(5), E6/(U(1)*Spin(10)), E6/F4, G2/SO(4), SU(3), Sp(2) and
G2.
  Similarly as for the spaces already investigated in the earlier papers, it
turns out that for many of the spaces investigated here, the earlier
classification of the maximal totally geodesic submanifolds of Riemannian
symmetric spaces by Chen and Nagano ([CN], Paragraph 9) is incomplete. In
particular, in the spaces Sp(2), G2/SO(4) and G2, there exist maximal totally
geodesic submanifolds, isometric to 2- or 3-dimensional spheres, which have a
"skew" position in the ambient space in the sense that their geodesic diameter
is strictly larger than the geodesic diameter of the ambient space. They are
all missing from [CN].


title: The eigenspectra of Indian musical drums

abstract:
  In a family of drums used in the Indian subcontinent, the circular drum head
is made of material of non-uniform density. Remarkably, and in contrast to a
circular membrane of uniform density, the low eigenmodes of the non-uniform
membrane are harmonic. In this work we model the drum head by a non-uniform
membrane whose density varies smoothly between two prescribed values. Using a
Fourier-Chebyshev spectral collocation method we obtain the eigenmodes and
eigenvalues of the drum head. For a suitable choice of parameters, which we
find by optimising a cost function, the eigenspectra obtained from our model
are in excellent agreement with experimental values. Our model and the
numerical method should find application in numerical sound synthesis.


title:
Numerical simulations of compressively driven interstellar turbulence:
  I. Isothermal gas

abstract:
  We performed numerical simulations of supersonic isothermal turbulence driven
by mostly compressive large-scale forcing, using both a static grid and
adaptive mesh refinement with an effective resolution N=768^3. After a
transient phase dominated by shocks, turbulence evolves into a steady state
with an RMS Mach number about 2.5, in which cloud-like structures of over-dense
gas are surrounded by highly rarefied gas. The index of the turbulence energy
spectrum function beta = 2.0 in the shock-dominated phase. As the flow
approaches statistical equilibrium, the spectrum flattens, with beta = 1.9. For
the scaling exponent of the root mean square velocity fluctuation, we obtain
gamma = 0.43 from the velocity structure functions of second order. These
results are well within the range of observed scaling properties for the
velocity dispersion in molecular clouds. Calculating structure functions of
order p=1,...,5, we find for all scaling exponents significant deviations from
the Kolmogorov-Burgers model proposed by Boldyrev. Our results are very well
described by a general log-Poisson model with a higher degree of intermittency,
which implies an influence of the forcing on the scaling properties. Contrary
to previous numerical results for isothermal turbulence, we obtain a skewed
probability density function of the mass density fluctuations that is not
consistent with log-normal statistics and entails a substantially higher
fraction of mass in the density peaks than implied by the Padoan-Nordlund
relation between the variance of the density fluctuations and the Mach number.
In conclusion, it seems necessary to account for the production mechanism of
turbulence in the ISM.


title: Are mergers responsible for universal halo properties?

abstract:
  N-body simulations of Cold Dark Matter (CDM) have shown that, in this
hierarchical structure formation model, dark matter halo properties, such as
the density profile, the phase-space density profile, the distribution of axial
ratio, the distribution of spin parameter, and the distribution of internal
specific angular momentum follow `universal' laws or distributions. Here we
study the properties of the first generation of haloes in a Hot Dark Matter
(HDM) dominated universe, as an example of halo formation through monolithic
collapse. We find all these universalities to be present in this case also.
Halo density profiles are very well fit by the Navarro et al (1997) profile
over two orders of magnitude in mass. The concentration parameter depends on
mass as $c \propto M^{0.2}$,reversing the dependence found in a hierarchical
CDM universe. However, the concentration-formation time relation is similar in
the two cases: earlier forming haloes tend to be more concentrated than their
later forming counterparts. Halo formation histories are also characterized by
two phases in the HDM case: an early phase of rapid accretion followed by
slower growth. Furthermore, there is no significant difference between the HDM
and CDM cases concerning the statistics of other halo properties: the
phase-space density profile; the velocity anisotropy profile; the distribution
of shape parameters; the distribution of spin parameter, and the distribution
of internal specific angular momentum are all similar in the two cases. Only
substructure content differs dramatically. These results indicate that mergers
do not play a pivotal role in establishing the universalities, thus
contradicting models which explain them as consequences of mergers.


title: Spontaneous trimerization in two-dimensional Antiferromagnets

abstract:
  In this paper, we propose a novel quantum paramagnetic state in
two-dimensional antiferromagnets: the spontaneously trimer state, which is
constructed by the trimers of spins. Each trimer is a singlet state formed by
three neighboring spins with SU(3) symmetry. A frustrated spin-1 Heisenberg
model in the kagome lattice is investigated. By analogy to the pseudo-potential
approach in the fractional quantum Hall effect (FQHE), we find that the trimer
state provides a perfect description for the exact ground state of this model.
Other interesting properties, such as the local excitations as well as
magnetization plateaus have also been investigated. It is shown that this novel
state would deepen our understanding of the nature of the many-body
entanglement in the two-dimensional strong correlated systems.


title: Generalised bottom-up holography and walking technicolour

abstract:
  In extradimensional holographic approaches the flavour symmetry is gauged in
the bulk, that is, treated as a local symmetry. Imposing such a local symmetry
admits fewer terms coupling the (axial) vectors and (pseudo)scalars than if a
global symmetry is imposed. The latter is the case in standard low-energy
effective Lagrangians. Here we incorporate these additional, a priori only
globally invariant terms into a holographic treatment by means of a
Stueckelberg completion and alternatively by means of a Legendre
transformation. This work was motivated by our investigations concerning
dynamical electroweak symmetry breaking by walking technicolour and we apply
our findings to these theories.


title: Inelastic cotunneling through a long diffusive wire

abstract:
  We show that electron transport through a long multichannel wire, connected
to leads by tunnel junctions, at low temperatures and voltages is dominated by
inelastic cotunnelling. This mechanism results in experimentally observed
power-law dependence of conductance on temperature and voltage, in the
diffusive regime where usual Coulomb anomaly theory leads to exponentially low
conductance. The power-law exponent is proportional to the distance between
contacts.


title: Fast Large-Scale Reionization Simulations

abstract:
  We present an efficient method to generate large simulations of the Epoch of
Reionization (EoR) without the need for a full 3-dimensional radiative transfer
code. Large dark-matter-only simulations are post-processed to produce maps of
the redshifted 21cm emission from neutral hydrogen. Dark matter haloes are
embedded with sources of radiation whose properties are either based on
semi-analytical prescriptions or derived from hydrodynamical simulations. These
sources could either be stars or power-law sources with varying spectral
indices. Assuming spherical symmetry, ionized bubbles are created around these
sources, whose radial ionized fraction and temperature profiles are derived
from a catalogue of 1-D radiative transfer experiments. In case of overlap of
these spheres, photons are conserved by redistributing them around the
connected ionized regions corresponding to the spheres. The efficiency with
which these maps are created allows us to span the large parameter space
typically encountered in reionization simulations. We compare our results with
other, more accurate, 3-D radiative transfer simulations and find excellent
agreement for the redshifts and the spatial scales of interest to upcoming 21cm
experiments. We generate a contiguous observational cube spanning redshift 6 to
12 and use these simulations to study the differences in the reionization
histories between stars and quasars. Finally, the signal is convolved with the
LOFAR beam response and its effects are analyzed and quantified. Statistics
performed on this mock data set shed light on possible observational strategies
for LOFAR.


title:
A critical review of the evidence for M32 being a compact dwarf
  satellite of M31 rather than a more distant normal galaxy

abstract:
  Since Baade's photographic study of M32 in the mid 1940s, it has been
accepted as an established fact that M32 is a compact dwarf satellite of M31.
The purpose of this paper is to report on the findings of our investigation
into the nature of the existing evidence. We find that the case for M32 being a
satellite of M31 rests upon Hubble Space Telescope (HST) based stellar
population studies which have resolved red-giant branch (RGB) and red clump
stars in M32 as well as other nearby galaxies. Taken in isolation, this recent
evidence could be considered to be conclusive in favour of the existing view.
However, the conventional scenario does not explain M32's anomalously high
central velocity dispersion for a dwarf galaxy (several times that of either
NGC 147, NGC 185 or NGC 205) or existing planetary nebula observations (which
suggest that M32 is more than twice as distant as M31) and also requires an
elaborate physical explanation for M32's inferred compactness. Conversely, we
find that the case for M32 being a normal galaxy, of the order of three times
as distant as M31, is supported by: (1) a central velocity dispersion typical
of intermediate galaxies, (2) the published planetary nebula observations, and
(3) known scaling relationships for normal early-type galaxies. However, this
novel scenario cannot account for the high apparent luminosities of the RGB
stars resolved in the M32 direction by HST observations. We are therefore left
with two apparently irreconcilable scenarios, only one of which can be correct,
but both of which suffer from potentially fatal evidence to the contrary. This
suggests that current understanding of some relevant fields is still very far
from adequate.


title: A complete lift for semisprays

abstract:
  In this paper, we define a complete lift for semisprays. If $S$ is a
semispray on a manifold $M$, its complete lift is a new semispray $S^c$ on
$TM$. The motivation for this lift is two-fold: First, geodesics for $S^c$
correspond to the Jacobi fields for $S$, and second, this complete lift
generalizes and unifies previously known complete lifts for Riemannian metrics,
affine connections, and regular Lagrangians. When $S$ is a spray, we prove that
the projective geometry of $S^c$ uniquely determines $S$. We also study how
symmetries and constants of motions for $S$ lift into symmetries and constants
of motions for $S^c$.


title: Plasma induced fermion spin-flip conversion $f_L \to f_R + \gamma$

abstract:
  The fermion spin-flip conversion $f_L \to f_R + \gamma$ is considered, caused
by the difference of the additional energies of the electroweak origin,
acquired by left- and right-handed fermions (neutrino, electron) in medium. An
accurate taking account of the fermion and photon dispersion in medium is shown
to be important.


title:
Low-Complexity Coding and Source-Optimized Clustering for Large-Scale
  Sensor Networks

abstract:
  We consider the distributed source coding problem in which correlated data
picked up by scattered sensors has to be encoded separately and transmitted to
a common receiver, subject to a rate-distortion constraint. Although
near-tooptimal solutions based on Turbo and LDPC codes exist for this problem,
in most cases the proposed techniques do not scale to networks of hundreds of
sensors. We present a scalable solution based on the following key elements:
(a) distortion-optimized index assignments for low-complexity distributed
quantization, (b) source-optimized hierarchical clustering based on the
Kullback-Leibler distance and (c) sum-product decoding on specific factor
graphs exploiting the correlation of the data.


title:
Coherent oscillations in a superconducting tunable flux qubit
  manipulated without microwaves

abstract:
  We experimentally demonstrate the coherent oscillations of a tunable
superconducting flux qubit by manipulating its energy potential with a
nanosecond-long pulse of magnetic flux. The occupation probabilities of two
persistent current states oscillate at a frequency ranging from 6 GHz to 21
GHz, tunable via the amplitude of the flux pulse. The demonstrated operation
mode allows to realize quantum gates which take less than 100 ps time and are
thus much faster compared to other superconducting qubits. An other advantage
of this type of qubit is its insensitivity to both thermal and magnetic field
fluctuations.


title:
Reliability analysis of semicoherent systems through their lattice
  polynomial descriptions

abstract:
  A semicoherent system can be described by its structure function or,
equivalently, by a lattice polynomial function expressing the system lifetime
in terms of the component lifetimes. In this paper we point out the parallelism
between the two descriptions and use the natural connection of lattice
polynomial functions and relevant random events to collect exact formulas for
the system reliability. We also discuss the equivalence between calculating the
reliability of semicoherent systems and calculating the distribution function
of a lattice polynomial function of random variables.


title: Photodesorption of ices I: CO, N2 and CO2

abstract:
  A longstanding problem in astrochemistry is how molecules can be maintained
in the gas phase in dense inter- and circumstellar regions. Photodesorption is
a non-thermal desorption mechanism, which may explain the small amounts of
observed cold gas in cloud cores and disk mid-planes. This paper aims to
determine the UV photodesorption yields and to constrain the photodesorption
mechanisms of three astrochemically relevant ices: CO, N2 and CO2. In addition,
the possibility of co-desorption in mixed and layered CO:N2 ices is explored.
The ice photodesorption is studied experimentally under ultra high vacuum
conditions and at 15-60 K using a hydrogen discharge lamp (7-10.5 eV). The ice
desorption during irradiation is monitored by reflection absorption infrared
spectroscopy of the ice and simultaneous mass spectrometry of the desorbed
molecules. Both the UV photodesorption yields per incident photon and the
photodesorption mechanisms are molecule specific. CO photodesorbs without
dissociation from the surface layer of the ice. N2, which lacks an electronic
transition in this wavelength range, has a photodesorption yield that is more
than an order of magnitude lower. This yield increases significantly due to
co-desorption when N2 is mixed in with or layered on top of CO ice. CO2
photodesorbs through dissociation and subsequent recombination from the top 10
layers of the ice. At low temperatures (15-18 K) the derived photodesorption
yields are 2.7x10^-3 and <2x10^-4 molecules photon-1 for pure CO and N2,
respectively. The CO2 photodesorption yield is 1.2x10^-3x(1-e^(-X/2.9)) +
1.1x10^-3x(1-e^(-X/4.6)) molecules photon-1, where X is the ice thickness in
monolayers and the two parts of the expression represent a CO2 and CO
photodesorption pathway.


title: The warping degree of a knot diagram

abstract:
  For an oriented knot diagram D, the warping degree d(D) is the smallest
number of crossing changes which are needed to obtain the monotone diagram from
D in the usual way. We show that d(D) + d(-D) + 1 is less than or equal to the
crossing number of D. Moreover the equality holds if and only if D is an
alternating diagram.


title: Detection of new states using forward proton tagging at the LHC

abstract:
  This talk summarises the ongoing proposals to upgrade the ATLAS and CMS
detectors by the installation of forward silicon detector systems close to the
beam line at distances of approximately 220 m and 420 m from the respective
Interaction Points. The physics motivation is outlined, with emphasis on
detection of Higgs and Supersymmetric states, and some of the aspects of the
apparatus and its performance are briefly described.


title:
Charge effect and finite 't Hooft coupling correction on drag force and
  Jet Quenching Parameter

abstract:
  The effects of charge and finite 't Hooft coupling correction on drag force
and jet quenching parameter are investigated. To study charge effect and finite
't Hooft coupling correction, we consider Maxwell charge and Gauss-Bonnet
terms, respectively. The background is Reissner-Nordstr\"{o}m-AdS black brane
solution in Gauss-Bonnet gravity. It is shown that these corrections affect
drag force and jet quenching parameter. We find an analytic solution of drag
force in this background which depends on Gauss-Bonnet coupling and charge. We
set Gauss-Bonnet coupling to be zero and find drag force in the case of
Reissner-Nordstr\"{o}m-AdS background. Also we discuss the relaxation time of a
moving heavy quark in this gravity background.


title: Remarques sur un article r'ecent de B. Poonen

abstract:
  B. Poonen recently produced smooth threefolds over a number field which do
not have a rational point but have no Brauer-Manin obstruction even after
descent to a finite 'etale cover. In this note I show that the varieties he
produces have zero-cycles of degree 1.
  -----
  B. Poonen a r'ecemment exhib'e des exemples de vari'et'es projectives et
lisses de dimension 3 sur un corps de nombres qui n'ont pas de point rationnel
et pour lesquelles il n'y a pas d'obstruction de Brauer-Manin apr`es
rev^etement fini 'etale. Dans cette note, je montre que les vari'et'es qu'il
construit poss`edent des z'ero-cycles de degr'e 1.


title:
Renormalization Group and Effective Potential in Classically Conformal
  Theories

abstract:
  We derive a general formula for the RG improved effective (Coleman-Weinberg)
potential for classically conformal models, applying it to several examples of
physical interest, and in particular a model of QCD coupled via quarks to a
colorless scalar field. The closed form expressions allow us to discuss the
range of validity of the effective potential as well as the issue of `large
logarithms' in a way different from previous such analyses. Remarkably, in all
examples considered, convexity of the effective potential is restored by the RG
improvement, or otherwise the potential becomes unstable. In the former case,
symmetry breaking becomes unavoidable due to the appearance of an infrared
barrier $\Lambda_{IR}$, which hints at a so far unsuspected link between
$\Lambda_{QCD}$ and the scale of electroweak symmetry breaking.


title: Nonperturbative aspects of Yang-Mills theory

abstract:
  In this thesis, several aspects of Yang-Mills theory are studied. It begins
with the constrained quantization in the Coulomb gauge, using the Dirac bracket
formalism. A nonperturbative analysis of the infrared asymptotics of
propagators in any spatial dimension follows, and a connection to the Landau
gauge is given. In the Coulomb gauge Hamiltonian approach, a linearly rising
static color Coulomb potential is found, along with an infrared diverging gluon
energy, both signaling confinement. The propagators and vertices in the entire
momentum regime are calculated with the variational principle. In the
ultraviolet, a nonperturbative running coupling constant is studied, and
certain asymptotic forms of the propagators are postulated. Furthermore, the
back reaction of the gauge sector to the inclusion of external charges is
investigated.


title: Relativistic diffusion

abstract:
  We discuss a relativistic diffusion in the proper time in an approach of
Schay and Dudley. We derive (Langevin) stochastic differential equations in
various coordinates.We show that in some coordinates the stochastic
differential equations become linear. We obtain momentum probability
distribution in an explicit form.We discuss a relativistic particle diffusing
in an external electromagnetic field. We solve the Langevin equations in the
case of parallel electric and magnetic fields. We derive a kinetic equation for
the evolution of the probability distribution.We discuss drag terms leading to
an equilibrium distribution.The relativistic analog of the Ornstein-Uhlenbeck
process is not unique. We show that if the drag comes from a diffusion
approximation to the master equation then its form is strongly restricted. The
drag leading to the Tsallis equilibrium distribution satisfies this restriction
whereas the one of the Juettner distribution does not. We show that any
function of the relativistic energy can be the equilibrium distribution for a
particle in a static electric field. A preliminary study of the time evolution
with friction is presented. It is shown that the problem is equivalent to
quantum mechanics of a particle moving on a hyperboloid with a potential
determined by the drag. A relation to diffusions appearing in heavy ion
collisions is briefly discussed.

categories: hep-th hep-ph math-ph math.MP physics.plasm-ph


title:
Can retired galaxies mimic active galaxies? Clues from the Sloan Digital
  Sky Survey

abstract:
  The classification of galaxies as star forming or active is generally done in
the ([O III]/Hbeta, [N II]/Halpha) plane. The Sloan Digital Sky Survey (SDSS)
has revealed that, in this plane, the distribution of galaxies looks like the
two wings of a seagull. Galaxies in the right wing are referred to as
Seyfert/LINERs, leading to the idea that non-stellar activity in galaxies is a
very common phenomenon. Here, we argue that a large fraction of the systems in
the right wing could actually be galaxies which stopped forming stars. The
ionization in these "retired" galaxies would be produced by hot post-AGB stars
and white dwarfs. Our argumentation is based on a stellar population analysis
of the galaxies via our STARLIGHT code and on photoionization models using the
Lyman continuum radiation predicted for this population. The proportion of
LINER galaxies that can be explained in such a way is however uncertain. We
further show how observational selection effects account for the shape of the
right wing. Our study suggests that nuclear activity may not be as common as
thought. If retired galaxies do explain a large part of the seagull's right
wing, some of the work concerning nuclear activity in galaxies, as inferred
from SDSS data, will have to be revised.


title:
Non-sequential recursive pair substitutions and numerical entropy
  estimates in symbolic dynamical systems

abstract:
  We numerically test the method of non-sequential recursive pair substitutions
to estimate the entropy of an ergodic source. We compare its performance with
other classical methods to estimate the entropy (empirical frequencies, return
times, Lyapunov exponent). We considered as a benchmark for the methods several
systems with different statistical properties: renewal processes, dynamical
systems provided and not provided with a Markov partition, slow or fast decay
of correlations. Most experiments are supported by rigorous mathematical
results, which are explained in the paper.

categories: cond-mat.stat-mech math.DS math.ST nlin.CD stat.TH


title: Writhe formulas and antipodal points in plectonemic DNA configurations

abstract:
  The linking and writhing numbers are key quantities when characterizing the
structure of a piece of supercoiled DNA. Defined as double integrals over the
shape of the double-helix, these numbers are not always straightforward to
compute, though a simplified formula exists. We examine the range of
applicability of this widely-used simplified formula, and show that it cannot
be employed for plectonemic DNA. We show that inapplicability is due to a
hypothesis of Fuller theorem that is not met. The hypothesis seems to have been
overlooked in many works.


title:
The Balanced Unicast and Multicast Capacity Regions of Large Wireless
  Networks

abstract:
  We consider the question of determining the scaling of the $n^2$-dimensional
balanced unicast and the $n 2^n$-dimensional balanced multicast capacity
regions of a wireless network with $n$ nodes placed uniformly at random in a
square region of area $n$ and communicating over Gaussian fading channels. We
identify this scaling of both the balanced unicast and multicast capacity
regions in terms of $\Theta(n)$, out of $2^n$ total possible, cuts. These cuts
only depend on the geometry of the locations of the source nodes and their
destination nodes and the traffic demands between them, and thus can be readily
evaluated. Our results are constructive and provide optimal (in the scaling
sense) communication schemes.


title: Escape Rates in a Stochastic Environment with Multiple Scales

abstract:
  We consider a stochastic environment with two time scales and outline a
general theory that compares two methods to reduce the dimension of the
original system. The first method involves the computation of the underlying
deterministic center manifold followed by a naive replacement of the stochastic
term. The second method allows one to more accurately describe the stochastic
effects and involves the derivation of a normal form coordinate transform that
is used to find the stochastic center manifold. The results of both methods are
used along with the path integral formalism of large fluctuation theory to
predict the escape rate from one basin of attraction to another. The general
theory is applied to the example of a surface flow described by a generic,
singularly perturbed, damped, nonlinear oscillator with additive, Gaussian
noise. We show how both nonlinear reduction methods compare in escape rate
scaling. Additionally, the center manifolds are shown to predict high
pre-history probability regions of escape. The theoretical results are
confirmed using numerical computation of the mean escape time and escape
prehistory, and we briefly discuss the extension of the theory to stochastic
control.


title: Semifluxon molecule under control

abstract:
  Josephson junctions with a phase drop pi in the ground state allow to create
vortices of supercurrent carrying only half of the magnetic flux quantum
Phi_0~2.07*10^-15 Wb. Such semifluxons have two-fold degenerate ground states
denoted up (with flux +Phi_0/2 and supercurrent circulating clockwise) and down
(with flux -Phi_0/2 and supercurrent circulating counterclockwise). We
investigate a molecule consisting of two coupled semifluxons in a 0-pi-0 long
Josephson junction. The fluxes (polarities) of semifluxons are measured by two
on-chip SQUIDs. By varying the dc bias current applied to the 0-pi-0 junction,
we demonstrate controllable manipulation and switching between two states,
up-down and down-up, of a semifluxon molecule. These results provide a major
step towards employing semifluxons as bits or qubits for classical and quantum
digital electronics.


title: On the flux of pseudo-Anosov homeomorphisms

abstract:
  We exhibit a pseudo-Anosov homeomorphism of a surface S which acts trivially
on the first homology group of S and whose flux is non zero


title: MBBP for improved iterative channel decoding in 802.16e WiMAX systems

abstract:
  We propose the application of multiple-bases belief-propagation, an optimized
iterative decoding method, to a set of rate-1/2 LDPC codes from the IEEE
802.16e WiMAX standard. The presented approach allows for improved decoding
performance when signaling over the AWGN channel. As all required operations
for this method can be run in parallel, the decoding delay of this method and
standard belief-propagation decoding are equal. The obtained results are
compared to the performance of LDPC codes optimized with the progressive
edge-growth algorithm and to bounds from information theory. It will be shown
that the discussed method mitigates the gap to the well-known random coding
bound by about 20 percent.


title: AEGIS-X: The Chandra Deep Survey of the Extended Groth Strip

abstract:
  We present the AEGIS-X survey, a series of deep Chandra ACIS-I observations
of the Extended Groth Strip. The survey comprises pointings at 8 separate
positions, each with nominal exposure 200ks, covering a total area of
approximately 0.67 deg2 in a strip of length 2 degrees. We describe in detail
an updated version of our data reduction and point source detection algorithms
used to analyze these data. A total of 1325 band-merged sources have been found
to a Poisson probability limit of 4e-6, with limiting fluxes of 5.3e-17
erg/cm2/s in the soft (0.5-2 keV) band and 3.8e-16 erg/cm2/s in the hard (2-10
keV) band. We present simulations verifying the validity of our source
detection procedure and showing a very small, <1.5%, contamination rate from
spurious sources. Optical/NIR counterparts have been identified from the DEEP2,
CFHTLS, and Spitzer/IRAC surveys of the same region. Using a likelihood ratio
method, we find optical counterparts for 76% of our sources, complete to
R(AB)=24.1, and, of the 66% of the sources that have IRAC coverage, 94% have a
counterpart to a limit of 0.9 microJy at 3.6 microns (m(AB)=23.8). After
accounting for (small) positional offsets in the 8 Chandra fields, the
astrometric accuracy of the Chandra positions is found to be 0.8 arcsec RMS,
however this number depends both on the off-axis angle and the number of
detected counts for a given source. All the data products described in this
paper are made available via a public website.


title: Proteus mirabilis swarm-colony development with drift

abstract:
  We prove a global existence result for a model describing the swarming
phenomenon of the bacterium Proteus mirabilis. The model consists of an
ordinary differential equation coupled with an age-structured equation
involving nonlinear degenerate diffusion and an additional drift term.


title:
Background Independent Quantum Mechanics, Classical Geometric Forms and
  Geometric Quantum Mechanics-I

abstract:
  The geometry of the symplectic structures and Fubini-Study metric is
discussed. Discussion in the paper addresses geometry of Quantum Mechanics in
the classical phase space. Also, geometry of Quantum Mechanics in the
projective Hilbert space has been discussed for the chosen Quantum states.
Since the theory of classical gravity is basically geometric in nature and
Quantum Mechanics is in no way devoid of geometry, the explorations pertaining
to more and more geometry in Quantum Mechanics could prove to be valuable for
larger objectives such as understanding of gravity.


title:
Angular momentum transport during X-ray bursts on neutron stars: a
  numerical general relativistic hydrodynamical study

abstract:
  The distribution of angular momentum of the matter during X-ray bursts on
neutron stars is studied by means of 3D axi-symmetric general relativistic
hydrodynamics. The set of fully general relativistic Navier-Stokes equations is
solved implicitly using the implicit solver GR-I-RMHD in combination with a
third order spatial and second order temporal advection scheme. The viscous
operators are formulated using a Kerr-like metric in the fixed background of a
slowly rotating neutron star whose radius coincides with the corresponding last
stable orbit. The importance of these operators and their possible
simplifications are discussed as well. In the rotating case and depending on
the viscosity parameter, $\alpha_\mm{tur}$, it is found that the
viscously-initiated fronts at the center of bursts propagate at much faster
speed than the fluid motion. These fast fronts act to decouple angular momentum
from matter: angular momentum is transported outwards while matter sinks
inwards into the deep gravitational well of the neutron star, thereby enhancing
the compression of matter necessary for initiating ignition, that subsequently
spreads over the whole surface of the neutron star on the viscous time scale.
Based on the numerical simulations, we find that a viscosity parameter
$\alpha_\mm{tur} = \mathcal{O}(0.1)$ is most suitable for fitting observations
of neutron stars during X-ray bursts. It is argued that the spin up observed in
the cooling tails of X-ray bursts is a transient phase, which eventually should
be followed by a spin down phase. This delay can be attributed to a significant
lengthening of the viscous time scale due to rapid cooling of matter in the
outer layers.


title: General Existence Results for Reflected BSDE and BSDE

abstract:
  In this paper, we are concerned with the problem of existence of solutions
for generalized reflected backward stochastic differential equations (GRBSDEs
for short) and generalized backward stochastic differential equations (GBSDEs
for short) when the generator $fds + gdA_s$ is continuous with general growth
with respect to the variable $y$ and stochastic quadratic growth with respect
to the variable $z$. We deal with the case of a bounded terminal condition
$\xi$ and a bounded barrier $L$ as well as the case of unbounded ones. This is
done by using the notion of generalized BSDEs with two reflecting barriers
studied in \cite{EH}. The work is suggested by the interest the results might
have in finance, control and game theory.


title: The evolution of conifolds

abstract:
  We simulate the gravitational dynamics of the conifold geometries (resolved
and deformed) involved in the description of certain compact spacetimes. As the
cycles of the conifold collapse towards a singular geometry we find that a
horizon develops, shielding the external spacetime from the curvature
singularity of the newly formed black hole. The structure of the black hole is
examined for a range of initial conditions, and we find a candidate black-hole
solution for the final state of the collapse.


title: The one-loop gluon amplitude for heavy-quark production at NNLO

abstract:
  We compute the one-loop QCD amplitude for the process gg-->Q\bar{Q} in
dimensional regularization through order \epsilon^2 in the dimensional
regulator and for arbitrary quark mass values. This result is an ingredient of
the NNLO cross-section for heavy quark production at hadron colliders. The
calculation is performed in conventional dimensional regularization, using well
known reduction techniques as well as a method based on recent ideas for the
functional form of one-loop integrands in four dimensions.


title: Hyperbolicity of geometric orbifolds

abstract:
  We study complex hyperbolicity in the setting of geometric orbifolds
introduced by F. Campana. Generalizing classical methods to this context, we
obtain degeneracy statements for entire curves with ramification in situations
where no Second Main Theorem is known from value distribution theory.


title:
Resonant X-ray scattering investigation of the multipolar ordering in
  Ca3Co2O6

abstract:
  We have performed a resonant x-ray scattering (RXS) study near the Co K edge
on a single crystal of Ca3Co2O6. In the magnetically ordered phase a new class
of weak reflections appears at the magnetic propagation vector tau
(1/3,1/3,1/3). These new reflections allow direct access to the
dipolar-quadrupolar E1E2 scattering channel. The theoretical possibility of
observing isolated E1E2 electromagnetic multipoles has attracted a lot of
interest in the recent years. Unfortunately in many system of interest, parity
even and parity odd tensor contributions occur at the same positions in
reciprocal space. We demonstrate that in Ca3Co2O6 it is possible to completely
separate the parity even from the parity odd terms. The possibility of
observing such terms even in globally centrosymmetric systems using RXS has
been investigated theoretically; Ca3Co2O6 allows a symmetry based separation of
this contribution.


title:
Critical thickness and orbital ordering in ultrathin La0.7Sr0.3MnO3
  films

abstract:
  Detailed analysis of transport, magnetism and x-ray absorption spectroscopy
measurements on ultrathin La0.7Sr0.3MnO3 films with thicknesses from 3 to 70
unit cells resulted in the identification of a lower critical thickness for a
non-metallic, non-ferromagnetic layer at the interface with the SrTiO3 (001)
substrate of only 3 unit cells (~12 Angstrom). Furthermore, linear dichroism
measurements demonstrate the presence of a preferred (x2-y2) in-plane orbital
ordering for all layer thicknesses without any orbital reconstruction at the
interface. A crucial requirement for the accurate study of these ultrathin
films is a controlled growth process, offering the coexistence of
layer-by-layer growth and bulk-like magnetic/transport properties.


title:
Electromagnetic pion and kaon form factors in light-cone resummed
  perturbative QCD

abstract:
  We analyze the electromagnetic pion and kaon form factor by including
radiative and higher-twist effects within the framework of resummed pQCD in the
space-like region. We focus on the transition from the perturbative to
non-perturbative behavior in the phenomenological intermediate energy regime.
Using a modified k_T factorization scheme with transverse degrees of freedom,
we evaluate the non-perturbative soft contributions as distinct from the hard
contributions, ensuring no double counting via the Ward identity at Q^2=0. The
soft contributions are obtained via local quark-hadron duality while the hard
contributions rest on the well known collinear factorization theorem using
model wave functions with modified Brodsky-Huang-Lepage type ansatz and
distribution amplitudes derived from light-cone QCD sum rules. Our analysis
shows that the perturbative hard part prevails for large Q^2 beyond 50-100
GeV^2, while for low and moderate momentum transfers below 10-16 GeV^2 the soft
contributions dominate over the hard part. Thus, we demonstrate the importance
of including the soft contributions for explaining the experimental form-factor
data.


title: D4 brane probes in gauge/gravity duality

abstract:
  We propose a DBI vertex brane + $N_c$ fundamental strings configuration for a
probe baryon in the finite-temperature thermal gauge field via AdS/CFT
correspondence. In particular, we investigate properties of this configuration
in QCD_4 and warped AdS_6\times S^4. We find that, in D4-D8 system, a
holographic probe baryon can be described as N_c fundamental strings connecting
through a vertex D4 brane wrapped on S^4. In QCD_4 background, a closed vertex
can exist in confined phase and can not exist in deconfined phase. In the low
temperature region, screening effect still exist in confined phase like meson
and the vertex D4 brane dominates the baryon mass. The lower energy state
corresponds to vertex brane closer to the radial cut off position (r=r_c) and
the higher energy state corresponds to vertex brane a little far away from the
cut off position. The high energy limit of this configuration is just like the
unclosed vertex brane configuration in a higher temperature deconfined phase.
In warped AdS_6\times S^4 background, a closed vertex can exist in deconfined
phase and the vertex contains a spike, while fundamental strings are relatively
short. Screening length should be defined through the distance between top
position of the vertex spike and the boundary.


title: Invariance and first integrals of canonical Hamiltonian equations

abstract:
  In this paper we consider the relation between symmetries and first integrals
of canonical Hamiltonian equations. Based on a newly established identity
(which is an analog of well known Noether's identity for Lagrangian approach),
this approach provides a simple and clear way to construct first integrals with
the help of symmetries of a Hamiltonian. The approach is illustrated by a
number of examples, including equations of the three-dimensional Kepler motion.


title: Observation of excited states in a p-type GaAs quantum dot

abstract:
  A quantum dot fabricated by scanning probe oxidation lithography on a p-type,
C-doped GaAs/AlGaAs heterostructure is investigated by low temperature
electrical conductance measurements. Clear Coulomb blockade oscillations are
observed and analyzed in terms of sequential tunneling through the
single-particle levels of the dot at T_hole = 185 mK. The charging energies as
large as 2 meV evaluated from Coulomb diamond measurements together with the
well resolved single-hole excited state lines in the charge stability diagram
indicate that the dot is operated with a small number of confined particles
close to the ultimate single-hole regime.


title:
Kuelshammer ideals and the scalar problem for blocks with dihedral
  defect groups

abstract:
  In by now classical work, K. Erdmann classified blocks of finite groups with
dihedral defect groups (and more generally algebras of dihedral type) up to
Morita equivalence. In the explicit description by quivers and relations of
such algebras with two simple modules, several subtle problems about scalars
occurring in relations remained unresolved. In particular, for the dihedral
case it is a longstanding open question whether blocks of finite groups can
occur for both possible scalars 0 and 1. In this article, using Kuelshammer
ideals (a.k.a. generalized Reynolds ideals), we provide the first examples of
blocks where the scalar is 1, thus answering the above question to the
affirmative. Our examples are the principal blocks of PGL_2(F_q), the
projective general linear group of 2x2-matrices with entries in the finite
field F_q, where q=p^n\equiv \pm 1 mod 8, with p an odd prime number.


title: Biases on the cosmological parameters and thermal SZ residuals

abstract:
  We examine the biases induced on cosmological parameters when the presence of
secondary anisotropies is not taken into account in Cosmic Microwave Background
analyses. We first develop an exact analytical expression for computing the
biases on parameters when any additive signal is neglected in the analysis. We
then apply it in the context of the forthcoming Planck experiment. For
illustration, we investigate the effect of the sole residual thermal
Sunyaev--Zel'dovich signal that remains after cluster extraction. We find in
particular that analyses neglecting the presence of this contribution introduce
on the cosmological parameters n_s and tau biases, at least 6.5 and 2.9 times
their one sigma confidence intervals. The Omega_b parameter is also biased to a
lesser extent.


title: Some notes on trees and paths

abstract:
  These notes cover background material on trees which are used in the paper
`On uniqueness of the signature of a path of variation and the reduced path
group'.


title: Network Coding Security: Attacks and Countermeasures

abstract:
  By allowing intermediate nodes to perform non-trivial operations on packets,
such as mixing data from multiple streams, network coding breaks with the
ruling store and forward networking paradigm and opens a myriad of challenging
security questions. Following a brief overview of emerging network coding
protocols, we provide a taxonomy of their security vulnerabilities, which
highlights the differences between attack scenarios in which network coding is
particularly vulnerable and other relevant cases in which the intrinsic
properties of network coding allow for stronger and more efficient security
solutions than classical routing. Furthermore, we give practical examples where
network coding can be combined with classical cryptography both for secure
communication and secret key distribution. Throughout the paper we identify a
number of research challenges deemed relevant towards the applicability of
secure network coding in practical networks.


title: Thermodynamics and Stability of Flat Anti-de Sitter Black Strings

abstract:
  We examine the thermodynamics and stability of 5-dimensional flat anti-de
Sitter (AdS) black strings, locally asymptotically anti-de Sitter spacetimes
whose spatial sections are AdS black holes with Ricci flat horizons. We find
that there is a phase transition for the flat AdS black string when the AdS
soliton string is chosen as the thermal background. We find that this bulk
phase transition corresponds to a 4-dimensional flat AdS black hole to AdS
soliton phase transition on the boundary Karch-Randall branes. We compute the
possibility of a phase transition from a flat AdS black string to a
5-dimensional AdS soliton and show that, though possible for certain thin black
strings, the transition to the AdS soliton string is preferred. In contrast to
the case of the Schwarzschild-AdS black string, we find that the specific heat
of the flat AdS black string is always positive; hence it is thermodynamically
stable. We show numerically that both the flat AdS black string and AdS soliton
string are free of a Gregory-Laflamme instability for all values of the mass
parameter. Therefore the Gubser-Mitra conjecture holds for these spacetimes.


title: Spin correlations in spin blockade

abstract:
  We investigate spin currents and spin-current correlations for double quantum
dots in the spin blockade regime. By analysing the time evolution of the
density matrix, we obtain the spin resolved currents and derive from a
generating function an expression for the fluctuations and correlations. Both
the charge current and the spin current turn out to be generally
super-Poissonian. Moreover, we study the influence of ac fields acting upon the
transported electrons. In particular, we focus on fields that cause spin
rotation or photon-assisted tunnelling.


title:
Astrometric suitability of optically-bright ICRF sources for the
  alignment with the future Gaia celestial reference frame

abstract:
  The ICRF, currently based on the position of 717 extragalactic radio sources
observed by VLBI, is the fundamental celestial reference frame adopted by the
IAU in 1997. Within the next 10 years, the European space astrometry mission
Gaia, to be launched by 2011, will permit determination of the extragalactic
reference frame directly in the visible for the first time. Aligning these two
frames with the highest accuracy will therefore be very important in the future
for ensuring consistency between the measured radio and optical positions. This
paper is aimed at evaluating the current astrometric suitability of the
individual ICRF radio sources which are considered appropriate for the
alignment with the future Gaia frame. To this purpose, we cross-identified the
ICRF and the optical catalog V\'eron-Cetty and V\'eron (2006), to identify the
optically-bright ICRF sources that will be positioned with the highest accuracy
with Gaia. Then we investigated the astrometric suitability of these sources by
examining their VLBI brightness distribution. We identified 243 candidate ICRF
sources for the alignment with the Gaia frame (with an optical counterpart
brighter than the apparent magnitude 18), but only 70 of these (10% of the ICRF
sources) are found to have the necessary high astrometric quality (i.e. a
brightness distribution that is compact enough) for this link. Additionally, it
was found that the QSOs that will have the most accurate positions in the Gaia
frame tend to have less-accurate VLBI positions, most probably because of their
physical structures. Altogether, this indicates that identifying other
high-quality VLBI radio sources suitable for the alignment with the future Gaia
frame is mandatory.


title:
Advent of Non-Abelian Vortices and Monopoles-- further thoughts about
  duality and confinement

abstract:
  Recent development on non-Abeliann vortices and monopoles is reviewed with an
emphasis on their relevance on confinement and duality. A very recent
construction of non-Abelian vortices which do not dynamically Abelianize is
crucial in this context.


title: Semiclassical Unimodular Gravity

abstract:
  Classically, unimodular gravity is known to be equivalent to General
Relativity (GR), except for the fact that the effective cosmological constant
$\Lambda$ has the status of an integration constant. Here, we explore various
formulations of unimodular gravity beyond the classical limit. We first
consider the non-generally covariant action formulation in which the
determinant of the metric is held fixed to unity. We argue that the
corresponding quantum theory is also equivalent to General Relativity for
localized perturbative processes which take place in generic backgrounds of
infinite volume (such as asymptotically flat spacetimes). Next, using the same
action, we calculate semiclassical non-perturbative quantities, which we expect
will be dominated by Euclidean instanton solutions. We derive the entropy/area
ratio for cosmological and black hole horizons, finding agreement with GR for
solutions in backgrounds of infinite volume, but disagreement for backgrounds
with finite volume. In deriving the above results, the path integral is taken
over histories with fixed 4-volume. We point out that the results are different
if we allow the 4-volume of the different histories to vary over a continuum
range. In this "generalized" version of unimodular gravity, one recovers the
full set of Einstein's equations in the classical limit, including the trace,
so $\Lambda$ is no longer an integration constant. Finally, we consider the
generally covariant theory due to Henneaux and Teitelboim, which is classically
equivalent to unimodular gravity. In this case, the standard semiclassical GR
results are recovered provided that the boundary term in the Euclidean action
is chosen appropriately.


title: Desperately seeking mathematical truth

abstract:
  This article discusses epistemological problems in the philosophy of
mathematics and issues concerning the reliability of the mathematical
literature.


title:
An Assessment of the Systematic Uncertainty in Present and Future Tests
  of the Lense-Thirring Effect with Satellite Laser Ranging

abstract:
  We deal with the attempts to measure the Lense-Thirring effect with the
Satellite Laser Ranging (SLR) technique applied to the existing LAGEOS and
LAGEOS II terrestrial satellites and to the recently approved LARES
spacecraft.The first issue addressed here is: are the so far published
evaluations of the systematic uncertainty induced by the bad knowledge of the
even zonal harmonic coefficients J_L of the multipolar expansion of the Earth's
geopotential reliable and realistic?
  Our answer is negative. Indeed, if the differences Delta J_L among the even
zonals estimated in different Earth's gravity field global solutions from the
dedicated GRACE mission are assumed for the uncertainties delta J_L instead of
using their covariance sigmas sigma_JL, it turns out that the systematic
uncertainty \delta\mu in the Lense-Thirring test with the nodes Omega of LAGEOS
and LAGEOS II may be up to 3 to 4 times larger than in the evaluations so far
published ($5-10%$) based on the use of the sigmas of one model at a time
separately. The second issue consists of the possibility of using a different
approach in extracting the relativistic signature of interest from the
LAGEOS-type data. The third issue is the possibility of reaching a realistic
total accuracy of 1% with LAGEOS, LAGEOS II and LARES, which should be launched
in November 2009 with a VEGA rocket. While LAGEOS and LAGEOS II fly at
altitudes of about 6000 km, LARES will be likely placed at an altitude of 1450
km. Thus, it will be sensitive to much more even zonals than LAGEOS and LAGEOS
II. Their corrupting impact has been evaluated with the standard Kaula's
approach up to degree L=60 by using Delta J_L and sigma_JL; it turns out that
it may be as large as some tens percent.

categories: gr-qc astro-ph physics.geo-ph physics.space-ph


title:
Vortices which do not Abelianize dynamically: Semi-classical origin of
  non-Abelian monopoles

abstract:
  After briefly reviewing the problems associated with non-Abelian monopoles,
we turn our attention to the development in our understanding of non-Abelian
{\it vortices} in the last several years. In the U(N) model with $N_{f}=N$
flavors in which they were first found, the fluctuations of the orientational
modes along the vortex length and in time become strongly coupled at long
distances. They effectively reduce to Abelian ANO vortices. We discuss then a
very recent work on non-Abelian vortices with $CP^{n-1}\times CP^{r-1}$
orientational moduli, which, unlike the ones so far extensively studied, do not
dynamically Abelianize completely. The surviving vortex orientational moduli,
fluctuating along the vortex length and in time, gets absorbed by the monopoles
at the ends, turning into the dual gauge degrees of freedom for the latter.


title:
Relativistic Nuclear Energy Density Functionals: adjusting parameters to
  binding energies

abstract:
  We study a particular class of relativistic nuclear energy density
functionals in which only nucleon degrees of freedom are explicitly used in the
construction of effective interaction terms. Short-distance (high-momentum)
correlations, as well as intermediate and long-range dynamics, are encoded in
the medium (nucleon density) dependence of the strength functionals of an
effective interaction Lagrangian. Guided by the density dependence of
microscopic nucleon self-energies in nuclear matter, a phenomenological ansatz
for the density-dependent coupling functionals is accurately determined in
self-consistent mean-field calculations of binding energies of a large set of
axially deformed nuclei. The relationship between the nuclear matter volume,
surface and symmetry energies, and the corresponding predictions for nuclear
masses is analyzed in detail. The resulting best-fit parametrization of the
nuclear energy density functional is further tested in calculations of
properties of spherical and deformed medium-heavy and heavy nuclei, including
binding energies, charge radii, deformation parameters, neutron skin thickness,
and excitation energies of giant multipole resonances.


title: Euclidean components for a class of self-injective algebras

abstract:
  We determine the length of composition series of projective modules of
G-transitive algebras with an Auslander-Reiten component of Euclidean tree
class. Furthermore we show that modules with certain length of composition
series are periodic. We apply these results to G-transitive blocks of the
Universal enveloping of restricted p-Lie algebras and prove that G-transitive
principal blocks only allow components with Euclidean tree class if p=2.
Finally we deduce conditions for a smash product of a local basic algebra with
a commutative semi-simple group algebra to have components with Euclidean tree
class, depending on the components of the Auslander-Reiten quiver of the basic
algebra. We also develop some properties of the bilinear form dim Hom_A(-,-)
for the representation ring G(A) of any finite-dimensional algebra A.


title:
Carbon Abundances of Three Carbon-Enhanced Metal-Poor Stars from
  High-Resolution Gemini-S/bHROS Spectra of the 8727A [C I] Line

abstract:
  We present the results from an analysis of the 8727ang forbidden [C I] line
in high-resolution Gemini-S/bHROS spectra of three CEMP stars. We find the
[C/Fe] ratios based on the [C I] abundances of the two most Fe-rich stars in
our sample (HIP 0507-1653: [Fe/H] = -1.42 and HIP 0054-2542: [Fe/H] = -2.66) to
be in good agreement with previously determined CH and C_2 line-based values.
For the most Fe-deficient star in our sample (HIP 1005-1439: [Fe/H] = -3.08),
however, the [C/Fe] ratio is found to be 0.34 dex lower than the published
molecular-based value. We have carried out 3D local thermodynamic equilibrium
(LTE) calculations for [C I], and the resulting corrections are found to be
modest for all three stars, suggesting that the discrepancy between the [C I]
and molecular-based C abundances of HIP 1005-1439 is due to more severe 3D
effects on the molecular lines. Carbon abundances are also derived from C I
high-excitation lines and are found to be 0.45-0.64 dex higher than the [C
I]-based abundances. Previously published non-LTE C I abundance corrections
bring the [C I] and C I abundances into better agreement; however, targeted
NLTE calculations for CEMP stars are clearly needed. We have also derived the
abundances of N, K, and Fe for each star. The Fe abundances agree well with
previously derived values, and the K abundances are similar to those of
C-normal metal-poor stars. Nitrogen abundances have been derived from resolved
lines of the CN red system. The abundances are found to be approximately 0.44
dex larger than literature values, which have been derived from CN blue bands
near 3880 and 4215 ang. We discuss evidence that suggests that analyses of the
CN blue system bands underestimate the N abundances of metal-poor giants.


title: On the Perturbative Approach in the Randall-Sundrum Model

abstract:
  We study a SU(2)_L x U(1)_Y gauge theory in the Randall-Sundrum background,
including electroweak symmetry breaking due to a brane-localized Higgs sector.
We work in the decomposed four dimensional theory and treat the symmetry
breaking effects as a perturbation. Although there is an exact approach, this
method is widely used and quite intuitive. We extend existing studies by giving
explicit analytical expressions in a covariant R_xi gauge, needed for loop
calculations in the decomposed theory. The perturbative approach is also
applied to fermions and a comparison of the gauge boson and fermion spectra
with the exact results is presented, validating the perturbative method used in
the literature.


title:
A Max-Flow Min-Cut Theorem with Applications in Small Worlds and Dual
  Radio Networks

abstract:
  Intrigued by the capacity of random networks, we start by proving a max-flow
min-cut theorem that is applicable to any random graph obeying a suitably
defined independence-in-cut property. We then show that this property is
satisfied by relevant classes, including small world topologies, which are
pervasive in both man-made and natural networks, and wireless networks of dual
devices, which exploit multiple radio interfaces to enhance the connectivity of
the network. In both cases, we are able to apply our theorem and derive
max-flow min-cut bounds for network information flow.


title: Introduction to Vertex Algebras

abstract:
  These lecture notes are intended to give a modest impulse to anyone willing
to start or pursue a journey into the theory of Vertex Algebras by reading one
of Kac's or Lepowsky-Li's books. Therefore, the primary goal is to provide
required tools and help being acquainted with the machinery which the whole
theory is based on. The exposition follows Kac's approach. Fundamental examples
relevant in Theoretical Physics are also discussed. No particular prerequisites
are assumed.


title: Effect of Disorder on the Quantum Coherence in Mesoscopic Wires

abstract:
  We present phase coherence time measurements in quasi-one-dimensional
mesoscopic wires made from high mobility two-dimensional electron gas. By
implanting gallium ions into a GaAs/AlGaAs heterojunction we are able to vary
the diffusion coefficient over 2 orders of magnitude. We show that in the
diffusive limit, the decoherence time follows a power law as a function of
diffusion coefficient as expected by theory. When the disorder is low enough so
that the samples are semi-ballistic, we observe a new and unexpected regime in
which the phase coherence time is independent of disorder. In addition, for all
samples the temperature dependence of the phase coherence time follows a power
law down to the lowest temperatures without any sign of saturation and strongly
suggests that the frequently observed low temperature saturation is not
intrinsic.


title:
Atomic and electronic structure transformations of silver nanoparticles
  under rapid cooling conditions

abstract:
  The structural evolution and dynamics of silver nanodrops Ag${}_{2896}$ (4.4
nm in diameter) during rapid cooling conditions has been studied by means of
molecular dynamics simulations and electronic density of state calculations.
The interaction of silver atoms is modeled by a tight-binding semiempirical
interatomic potential proposed by Cleri and Rosato. The pair correlation
functions and the pair analysis technique is applied to reveal the structural
transition in the process of solidification. It is shown that Ag nanoparticles
evolve into different nanostructures under different cooling processes. At a
cooling rate of $1.5625\times10^{13} Ks^{-1}$ the nanoparticles preserve an
amorphous like structure containing a large amount of 1551 and 1541 pairs which
correspond to the icosahedral symmetry. For a lower cooling rate
($1.5625\times10^{12} Ks^{-1}$), the nanoparticles transform into a
crystal-like structure consisting mainly of 1421 and 1422 pairs which
correspond to the fcc and hcp structures, respectively. The variations of the
electronic density of states for the differently cooled nanoparticles are small
but in correspondence with the structural changes.


title: Interactions of cosmological gravitational waves and magnetic fields

abstract:
  The energy momentum tensor of a magnetic field always contains a spin-2
component in its anisotropic stress and therefore generates gravitational
waves. It has been argued in the literature (Caprini & Durrer \cite{CD}) that
this gravitational wave production can be very strong and that back-reaction
cannot be neglected. On the other hand, a gravitational wave background does
affect the evolution of magnetic fields. It has also been argued (Tsagas et al.
\cite{Tsagas:2001ak},\cite{Tsagas:2005ki}) that this can lead to very strong
amplification of a primordial magnetic field. In this paper we revisit these
claims and study back reaction to second order.