title: Comment on "Phase Reduction of Stochastic Limit Cycle Oscillators"

abstract:
  This is a comment on a recent paper by Yoshimura and Arai [Phys. Rev. Lett.
101, 154101 (2008)] on phase reduction of noisy limit-cycle oscillators, in
which the authors claimed that the conventional phase stochastic differential
equation used in previous studies does not give a proper approximation and
proposed a modified phase equation. Here we point out that both phase equations
are valid depending on the situation. We argue that the relative size of
amplitude relaxation time and noise correlation time determines which of the
two equations is appropriate in the white-noise limit. The conventional phase
equation is also a proper approximation to noisy limit cycles with sufficiently
fast amplitude relaxation, which can be used as a starting point for further
analysis.


title:
Non-perturbative renormalization of Nf=2+1 QCD with Schroedinger
  functional scheme

abstract:
  We present a preliminary result of Nf=2+1 QCD running coupling in
Schroedinger functional scheme. We adopted Iwasaki gauge action and
non-perturbatively improved Wilson fermion action with clover term. We use
seven renormalization scales to cover from low energy to high energy
perturbative region and three lattice spacings to take the continuum limit at
each scale.
  A scaling behabior of the step scaling function is discussed together with
its renoralization group flow in the continuum. We argue on introduction of the
physical scale through the Sommer scale r0.


title:
Halfway Up To the Mathematical Infinity: On the Ontological and
  Epistemic Sustainability of Georg Cantor's Transfinite Design

abstract:
  Georg Cantor was the genuine discoverer of the Mathematical Infinity, and
whatever he claimed, suggested, or even surmised should be taken seriously --
albeit not necessary at its face value. Because alongside his exquisite in
beauty ordinal construction and his fundamental powerset description of the
continuum, Cantor has also left to us his obsessive presumption that the
universe of sets should be subjected to laws similar to those governing the set
of natural numbers, including the universal principles of cardinal
comparability and well-ordering -- and implying an ordinal re-creation of the
continuum. During the last hundred years, the mainstream set-theoretical
research -- all insights and adjustments due to Kurt G\"odel's revolutionary
insights and discoveries notwithstanding -- has compliantly centered its
efforts on \emph{ad hoc} axiomatizations of Cantor's intuitive transfinite
design. We demonstrate here that the ontological and epistemic
\emph{sustainability} of this design has been irremediably compromised by the
underlying it peremptory, Reductionist mindset of the XIXth century's ideology
of science.


title: Time and Space Varying Copulas

abstract:
  In this article we review existing literature on dynamic copulas and then
propose an n-copula which varies in time and space. Our approach makes use of
stochastic differential equations, and gives rise to a dynamic copula which is
able to capture the dependence between multiple Markov diffusion processes.
This model is suitable for pricing basket derivatives in finance and may also
be applicable to other areas such as bioinformatics and environmental science.


title:
Constraints on accelerating universe using ESSENCE and Gold supernovae
  data combined with other cosmological probes

abstract:
  We use recently observed data: the 192 ESSENCE type Ia supernovae (SNe Ia),
the 182 Gold SNe Ia, the 3-year WMAP, the SDSS baryon acoustic peak, the X-ray
gas mass fraction in clusters and the observational $H(z)$ data to constrain
models of the accelerating universe. Combining the 192 ESSENCE data with the
observational $H(z)$ data to constrain a parameterized deceleration parameter,
we obtain the best fit values of transition redshift and current deceleration
parameter $z_{T}=0.632^{+0.256}_{-0.127}$, $q_{0}=-0.788^{+0.182}_{-0.182}$.
Furthermore, using $\Lambda$CDM model and two model-independent equation of
state of dark energy, we find that the combined constraint from the 192 ESSENCE
data and other four cosmological observations gives smaller values of
$\Omega_{0m}$ and $q_{0}$, but a larger value of $z_{T}$ than the combined
constraint from the 182 Gold data with other four observations. Finally,
according to the Akaike information criterion it is shown that the recently
observed data equally supports three dark energy models: $\Lambda$CDM,
$w_{de}(z)=w_{0}$ and $w_{de}(z)=w_{0}+w_{1}\ln(1+z)$.


title:
Sensitivity coefficients to $\alpha$-variation for fine-structure
  transitions in Carbon-like ions

abstract:
  We calculate sensitivity coefficients to $\alpha$-variation for the
fine-structure transitions (1,0) and (2,1) within $^3P_J[2s^2 2p^2]$ multiplet
of the Carbon-like ions C I, N II, O III, Na VI, Mg VII, and Si IX. These
transitions lie in the far infrared region and are in principle observable in
astrophysics for high redshifts z~10. This makes them very promising candidates
for the search for possible $\alpha$-variation on a cosmological timescale. In
such studies one of the most dangerous sources of systematic errors is
associated with isotope shifts. We calculate isotope shifts with the help of
relativistic mass shift operator and show that it may be significant for C I,
but rapidly decreases along the isoelectronic sequence and becomes very small
for Mg VII and Si IX.


title:
Field-free molecular alignment induced by elliptically polarized laser
  pulses: non invasive 3 dimensional characterization

abstract:
  An investigation of field-free molecular alignment produced by elliptically
polarized laser pulses is reported. Experiments are conducted in CO$_2$ at room
temperature. A non invasive all-optical technique, based on the cross
defocusing of a probe pulse, is used to measure the alignment along two
orthogonal directions that is sufficient to provide a 3 dimensional
characterization. The field-free molecular alignment produced by a laser of
elliptical polarization is in good agreement in terms of amplitude and shape
with theoretical predictions. It turns out to be almost equivalent to the
superposition of the effects that one would obtain with two individual
cross-polarized pulses. The investigation highlights notably the occurrence of
field-free two-direction alignment alternation for a suitably chosen degree of
ellipticity. The analogy between this specific ellipticity and the well known
"magic angle" used in time resolved spectroscopy to prevent rotational
contributions is discussed.


title: Ground state energy of N Frenkel excitons

abstract:
  By using the composite many-body theory for Frenkel excitons we have recently
developed, we here derive the ground state energy of $N$ Frenkel excitons in
the Born approximation through the Hamiltonian mean value in a state made of
$N$ identical $\mathbf{Q=0}$ excitons. While this quantity reads as a density
expansion in the case of Wannier excitons, due to many-body effects induced by
fermion exchanges between $N$ composite particles, we show that the Hamiltonian
mean value for $N$ Frenkel excitons only contains a first order term in
density, just as for elementary bosons. Such a simple result comes from a
subtle balance, difficult to guess a priori, between fermion exchanges for two
or more Frenkel excitons appearing in Coulomb term and the ones appearing in
the $N$ exciton normalization factor - the cancellation being exact within
terms in $1/N_{s}$ where $N_{s}$ is the number of atomic sites in the sample.
This result could make us naively believe that, due to the tight binding
approximation on which Frenkel excitons are based, these excitons are just bare
elementary bosons while their composite nature definitely appears at various
stages in the precise calculation of the Hamiltonian mean value.


title: Metastable supersymmetry breaking and multitrace deformations of SQCD

abstract:
  Metastable vacua in supersymmetric QCD in the presence of single and
multitrace deformations of the superpotential are explored, with the aim of
obtaining an acceptable phenomenology. The metastable vacua appear at one loop,
have a broken R-symmetry, and a magnetic gauge group that is completely
Higgsed. With only a single trace deformation, the adjoint fermions from the
meson superfield are approximately massless at one loop, even though they are
massive at tree level and R-symmetry is broken. Consequently, if charged under
the standard model, they are unacceptably light. A multitrace quadratic
deformation generates fermion masses proportional to the deformation parameter.
Phenomenologically viable models of direct gauge mediation can then be
obtained, and some of their features are discussed.


title:
Two conjectures such that the proof of any one of them will lead to the
  proof that P = NP

abstract:
  In this paper we define a construct called a time-graph. A complete
time-graph of order n is the cartesian product of a complete graph with n
vertices and a linear graph with n vertices. A time-graph of order n is given
by a subset of the set of edges E(n) of such a graph. The notion of a
hamiltonian time-graph is defined in a natural way and we define the
Hamiltonian time-graph problem (HAMTG) as : Given a time-graph is it
hamiltonian ? We show that the Hamiltonian path problem (HAMP) can be
transformed to HAMTG in polynomial time. We then define certain vector spaces
of functions from E(n) and E(n)xE(n) to B = {0,1}, the field of two elements
and derive certain properties of these spaces. We give two conjectures about
these spaces and prove that if any one of these conjectures is true, we get a
polynomial time algorithm for the Hamiltonian path problem. Since the
Hamiltonian path problem is NP-complete we obtain the proof of P = NP provided
any one of the two conjectures is true.


title:
MC-TESTER v. 1.23: a universal tool for comparisons of Monte Carlo
  predictions for particle decays in high energy physics

abstract:
  Theoretical predictions in high energy physics are routinely provided in the
form of Monte Carlo generators. Comparisons of predictions from different
programs and/or different initialization set-ups are often necessary. MC-TESTER
can be used for such tests of decays of intermediate states (particles or
resonances) in a semi-automated way.
  Since 2002 new functionalities were introduced into the package. In
particular, it now works with the HepMC event record, the standard for C++
programs. The complete set-up for benchmarking the interfaces, such as
interface between tau-lepton production and decay, including QED bremsstrahlung
effects is shown. The example is chosen to illustrate the new options
introduced into the program. From the technical perspective, our paper
documents software updates and supplements previous documentation.
  As in the past, our test consists of two steps. Distinct Monte Carlo programs
are run separately; events with decays of a chosen particle are searched, and
information is stored by MC-TESTER. Then, at the analysis step, information
from a pair of runs may be compared and represented in the form of tables and
plots.
  Updates introduced in the progam up to version 1.24.3 are also documented. In
particular, new configuration scripts or script to combine results from
multitude of runs into single information file to be used in analysis step are
explained.


title: On Hofmann's bilinear estimate

abstract:
  Using the framework of a previous article joint with Axelsson and McIntosh,
we extend to systems two results of S. Hofmann for real symmetric equations and
their perturbations going back to a work of B. Dahlberg for Laplace's equation
on Lipschitz domains, The first one is a certain bilinear estimate for a class
of weak solutions and the second is a criterion which allows to identify the
domain of the generator of the semi-group yielding such solutions.


title:
New form of the Boltzmann constant from search for a permanent electric
  dipole moment of K, Rb or Cs atom

abstract:
  Using special capacitors our experiments discovered that the ground state K,
Rb or Cs atom is polar atom with a large permanent electric dipole moment (EDM)
of the order of eao (ao is Bohr radius) as excited state of hydrogen atom. But
we can not calculate the EDM of an atom using Boltzmann constant. The mechanism
of polar atoms by which orientation polarization arises completely differs from
polar molecules. The orientation polarization of polar molecule, such as HCl or
H2O etc, is a molecule as a whole turned toward the direction of an external
field. Unlike polar molecules, the orientation polarization of polar atom, such
as K, Rb or Cs atom, is only the valence electron in the outermost shell, along
a highly elliptical orbit, turned toward the direction of the field, but the
rest of the atom does not move! The article derived the new form of Boltzmann
constant. When it was applied to orientation polarization of polar atoms, its
value k is far less than 1.38*10-23 J/K(for example, k=7.14*10-29 J/K for Cs
atom) . When it was applied to any molecule, non-polar atom or translation and
vibration of polar atom, its value k=1.38*10-23J/K. The reason is that the
nucleus moves together with the rest of the molecule or atom. (see
arXiv:0809.4767; arXiv:0810.0770; arXiv:0810.2026)


title: Soft-wall model of AdS/QCD: The case of light scalar mesons

abstract:
  We study light scalar mesons in the AdS/QCD soft-wall model with a background
dilaton field, to investigate the features of this approach in describing QCD
properties in the strong coupling regime. We find that the masses and decay
constants are compatible with experiment and QCD determinations if $a_0(980)$
and $f_0(980)$ are identified as the lightest scalar mesons; moreover, the
states are organized in linear Regge trajectories with the same slope of vector
mesons. Strong couplings of scalar states to pairs of light pseudoscalar mesons
turn out to be small, at odds with experiment and QCD estimates: this
discrepancy is related to the description of chiral symmetry breaking in this
holographic model.


title: A pilot survey of stellar tidal streams in nearby spiral galaxies

abstract:
  Within the hierarchical framework for galaxy formation, merging and tidal
interactions are expected to shape large galaxies to this day. While major
mergers are quite rare at present, minor mergers and satellite disruptions -
which result in stellar streams - should be common, and are indeed seen in both
the Milky Way and the Andromeda Galaxy. As a pilot study, we have carried out
ultra-deep, wide-field imaging of some spiral galaxies in the Local Volume,
which has revealed external views of such stellar tidal streams at
unprecedented detail, with data taken at small robotic telescopes
(0.1-0.5-meter) that provide exquisite surface brightness sensitivity. The goal
of this project is to undertake the first systematic and comprehensive imaging
survey of stellar tidal streams, from a sample of ~50 nearby Milky-Way-like
spiral galaxies within 15 Mpc, that features a surface brightness sensitivity
of ~ 30 mag/arcsec^2 The survey will result in estimates of the incidence,
size/geometry and stellar luminosity/mass distribution of such streams. This
will not only put our Milky Way and M31 in context but, for the first time,
also provide an extensive statistical basis for comparison with
state-of-the-art, self-consistent cosmological simulations of this phenomenon.


title:
Transverse momentum spectra of D and B mesons in hadron collisions at
  high energies

abstract:
  Transverse momentum spectra of charmed and beauty mesons produced in
proton-proton and proton-antiproton collisions at high energies are analyzed
within the modified quark-gluon string model (QGSM) including the internal
motion of quarks in colliding hadrons. It is shown that this approach can
describe rather satisfactorily the experimental data at not large values of the
transverse momentum where the NLO QCD calculation has a big uncertainty. We
also show that using both the QGSM and the NLO QCD one can describe these data
in a wide region of transverse momenta and give some predictions for the future
LHC experiments.


title:
Upper bounds on Rubinstein distances on configuration spaces and
  applications

abstract:
  In this paper, we provide upper bounds on several Rubinstein-type distances
on the configuration space equipped with the Poisson measure. Our inequalities
involve the two well-known gradients, in the sense of Malliavin calculus, which
can be defined on this space. Actually, we show that depending on the distance
between configurations which is considered, it is one gradient or the other
which is the most effective. Some applications to distance estimates between
Poisson and other more sophisticated processes are also provided, and an
application of our results to tail and isoperimetric estimates completes this
work.


title: The elliptic threefold y^2=x^3+16s^6+16t^6-32(t^3s^3+t^3+s^3)+16

abstract:
  We present a method to calculate the rank of $E(\oQ(s,t))$ for the elliptic
curve mentioned in the title. This method uses a generalization of a method
from Van Geemen and Werner to calculate $h^4(Y)$ for nodal hypersurfaces $Y$.


title:
Ultra-sensitive in-beam gamma-ray spectroscopy for nuclear astrophysics
  at LUNA

abstract:
  Ultra-sensitive in-beam gamma-ray spectroscopy studies for nuclear
astrophysics are performed at the LUNA (Laboratory for Underground Nuclear
Astrophysics) 400 kV accelerator, deep underground in Italy's Gran Sasso
laboratory. By virtue of a specially constructed passive shield, the laboratory
gamma-ray background for E_\gamma < 3 MeV at LUNA has been reduced to levels
comparable to those experienced in dedicated offline underground gamma-counting
setups. The gamma-ray background induced by an incident alpha-beam has been
studied. The data are used to evaluate the feasibility of sensitive in-beam
experiments at LUNA and, by extension, at similar proposed facilities.


title:
Local effects in astrometric binary orbits: perspective transformation
  and light-travel time

abstract:
  In order to get astrometric parameters achieving the precision permitted by
the the forthcoming generation of astrometri cmeasurements, it will be
necessary to take into account effects that were neglected until the present
time. Two effects concerning the orbital elements of binary stars are
considered hereafter: the former is the local perspective (LP) effect, which is
due to the variation of the distance and of the orientation of the orbital
plane during the observation time span. The latter effect is the light--travel
time (LTT), which is also related to the orientation of the orbital plane.
Taking these effects into account would allow to find the ascending nodes of
the orbits, and lead to orbital elements more accurate than when they are
ignored. It is derived from simulations that, at a distance of 5 pc, and
assuming velocities typical of Pop.I stars, the position of the right ascending
node could be derived for a few simulated unresolved binaries when the
astrometric measurements have errors around 1 microas. For the resolved brown
dwarf binary 2MASS J07464256 +2000321, it appears that ignoring the LP effect
would result in underestimating the masses of the components by 14 per cent of
the errors as soon as the astrometric errors are around 20 microas for each
measurement. However, a `degenerate LP solution', taking into account the
variation of the semi-major axis when the distance is varying, should provide
reliable masses when the measurement errors are larger than 1 or 2 microas. A
few binaries in the Gaia program could deserve a degenerate LP solution,
whereas a the complete LP+LTT solution could be justified for resolved binaries
observed with SIM.


title: Heavy Quarkonia beyond Deconfinement and Real Time Lattice Simulations

abstract:
  Since the initial investigation by Matsui and Satz heavy quark bound states
at finite temperature have been subject to numerous studies. The derivation of
a finite-temperature potential from first principles was attempted only
recently however, by generalising the Schroedinger equation which is
successfully employed for the description of quarkonia at zero temperature to a
thermal setting. In this note the finite-temperature static potential is
derived to leading order using resummed perturbation theory. The modification
of the heavy quarkonium spectral function by an imaginary part of the potential
appearing at finite temperature is discussed. Additionally, the extent of
possible corrections due to non-perturbative processes is assessed by employing
real-time lattice techniques based on kinetic theory.


title:
BiopSym: a simulator for enhanced learning of ultrasound-guided prostate
  biopsy

abstract:
  This paper describes a simulator of ultrasound-guided prostate biopsies for
cancer diagnosis. When performing biopsy series, the clinician has to move the
ultrasound probe and to mentally integrate the real-time bi-dimensional images
into a three-dimensional (3D) representation of the anatomical environment.
Such a 3D representation is necessary to sample regularly the prostate in order
to maximize the probability of detecting a cancer if any. To make the training
of young physicians easier and faster we developed a simulator that combines
images computed from three-dimensional ultrasound recorded data to haptic
feedback. The paper presents the first version of this simulator.


title: Filtering of complex systems using overlapping tree networks

abstract:
  We introduce a technique that is capable to filter out information from
complex systems, by mapping them to networks, and extracting a subgraph with
the strongest links. This idea is based on the Minimum Spanning Tree, and it
can be applied to sets of graphs that have as links different sets of
interactions among the system's elements, which are described as network nodes.
It can also be applied to correlation-based graphs, where the links are
weighted and represent the correlation strength between all pairs of nodes. We
applied this method to the European scientific collaboration network, which is
composed of all the projects supported by the European Framework Program FP6,
and also to the correlation-based network of the 100 highest capitalized stocks
traded in the NYSE. For both cases we identified meaningful structures, such as
a strongly interconnected community of countries that play important role in
the collaboration network, and clusters of stocks belonging to different
sectors of economic activity, which gives significant information about the
investigated systems.


title: Edge Universality for Orthogonal Ensembles of Random Matrices

abstract:
  We prove edge universality of local eigenvalue statistics for orthogonal
invariant matrix models with real analytic potentials and one interval limiting
spectrum. Our starting point is the result of \cite{S:08} on the representation
of the reproducing matrix kernels of orthogonal ensembles in terms of scalar
reproducing kernel of corresponding unitary ensemble.


title:
Variational RVB wave function for the spin-1/2 Heisenberg Model on
  honeycomb lattice

abstract:
  In this work, a long-range resonating valence bond state is proposed as a
variational wave function for the ground state of the $S=1/2$ antiferromagnetic
Heisenberg model on the honeycomb lattice. Employing Variational Monte Carlo
(VMC) method, we show that the ground state energy obtained from such RVB wave
function, lies well below the energy of the N\'eel state and compares very well
to the energies evaluated from spin-wave theory and series expansion method. We
also obtain the spin-spin correlation function along zig-zag and armchair
directions and find that the two correlations are different, which indicates
the anisotropic nature of the system. We compare our results with the square
lattice and we show that although the quantum fluctuations on honeycomb lattice
are much stronger, but do not completely destroy the magnetic order.


title: Accuracy of the cluster-approximation method in a nonequilibrium model

abstract:
  We examine a model in which a nonequilibrium phase transition from an active
to an extinct state is observed. The order of this phase transition has been
shown to be either continuous or first-order, depending on the parameter values
and the dimension of the system. Using increasingly large clusters, we use the
cluster approximation method to obtain estimates for the critical points in 1+1
dimensions. For the continuous phase transitions only, extrapolations of these
approximations show excellent agreement with simulation results. Further, the
approximations suggest that, consistent with simulation results, in 1+1
dimensions no first-order phase transitions are observed.


title: Relevement de formes modulaires de Siegel

abstract:
  Dans cette note, nous montrons que certaines formes modulaires de Siegel de
caract\'eristique p et de genre 2 ou 3 se rel\`event en caract\'eristique 0. Ce
r\'esultat g\'en\'eralise un th\'eor\`eme classique obtenu par Katz pour les
formes de genre 1. Nous utilisons des r\'esultats de Shepherd-Barron et de
Hulek et Sankaran, ainsi que des th\'eor\`emes d'annulation de la cohomologie
coh\'erente d\^us \`a Deligne, Illusie et Raynaud et \`a Esnault et Viehweg.
  -----
  In this note, we show that cuspidal Siegel modular forms of characteristic p
and genus 2 or 3 can be lifted to characteristic 0. This result extends a
classical theorem proved by Katz for genus 1 modular forms. We use ampleness
results due to Shepherd-Barron, Hulek and Sankaran, and vanishing theorems due
to Deligne, Illusie, Raynaud, Esnault and Viehweg.


title: Maximum Sum-Rate of MIMO Multiuser Scheduling with Linear Receivers

abstract:
  We analyze scheduling algorithms for multiuser communication systems with
users having multiple antennas and linear receivers. When there is no feedback
of channel information, we consider a common round robin scheduling algorithm,
and derive new exact and high signal-to-noise ratio (SNR) maximum sum-rate
results for the maximum ratio combining (MRC) and minimum mean squared error
(MMSE) receivers. We also present new analysis of MRC, zero forcing (ZF) and
MMSE receivers in the low SNR regime. When there are limited feedback
capabilities in the system, we consider a common practical scheduling scheme
based on signal-to-interference-and-noise ratio (SINR) feedback at the
transmitter. We derive new accurate approximations for the maximum sum-rate,
for the cases of MRC, ZF and MMSE receivers. We also derive maximum sum-rate
scaling laws, which reveal that the maximum sum-rate of all three linear
receivers converge to the same value for a large number of users, but at
different rates.


title: On the nonexistence of ternary extremal self-dual codes

abstract:
  In this note, we give a new nonexistence result of ternary extremal self-dual
codes.


title: Bifurcation and pattern changing with two real scalar fields

abstract:
  This work deals with bifurcation and pattern changing in models described by
two real scalar fields. We consider generic models with quartic potentials and
show that the number of independent polynomial coefficients affecting the
ratios between the various domain wall tensions can be reduced to 4 if the
model has a superpotential. We then study specific one-parameter families of
models and compute the wall tensions associated with both BPS and non-BPS
sectors. We show how bifurcation can be associated to modification of the
patterns of domain wall networks and illustrate this with some examples which
may be relevant to describe realistic situations of current interest in high
energy physics. In particular, we discuss a simple solution to the cosmological
domain wall problem.


title: Non thermal emission from microquasar/ISM interaction

abstract:
  The interaction of microquasar jets with their environment can produce
non-thermal radiation as is the case for extragalactic outflows impacting on
their surroundings. We have developed an analytical model based on those
successfully applied to extragalactic sources. The jet is taken to be a
supersonic and mildly relativistic hydrodynamical outflow. We focus on the
jet/shocked medium structure when being in its adiabatic phase, and assume that
it grows in a self-similar way. We calculate the fluxes and spectra of the
radiation produced via synchrotron, Inverse Compton and relativistic
Bremsstrahlung processes by electrons accelerated in strong shocks. A
hydrodynamical simulation is also performed to further investigate the jet
interaction with the environment and check the physical parameters used in the
analytical model. We conclude that microquasar jet termination regions could be
detectable at radio wavelengths for current instruments sensitive to arcminute
scales while at X-rays the expected luminosities are moderate, although the
emitter is more compact than the radio one. The radiation at gamma-ray energies
may be within the detection limits of the next generation of satellite and
ground-based instruments.


title: On the Siegel-Weil Theorem for Loop Groups (I)

abstract:
  We proved a new Siegel-Weil formula for orthogonal and symplectic groups,
which will be used later to prove a generalization of Siegel-Weil formula for
loop groups.


title:
The Structures of Distant Galaxies - III: The Merger History of over
  20,000 Massive Galaxies at z < 1.2

abstract:
  Utilizing deep Hubble Space Telescope imaging from the two largest field
galaxy surveys, the Extended Groth Strip (EGS) and the COSMOS survey, we
examine the structural properties, and derive the merger history for 21,902
galaxies with M_*>10^{10} M_0 at z<1.2. We examine the structural CAS
parameters of these galaxies, deriving merger fractions, at 0.2<z<1.2, based on
the asymmetry and clumpiness values of these systems. We find that the merger
fraction between z=0.2 and z=1.2 increases from roughly f_m=0.04+/-0.01 to
f_m=0.13+/-0.01. We explore several fitting formalisms for parameterising the
merger fraction, and compare our results to other structural studies and pair
methods within the DEEP2, VVDS, and COSMOS fields. We also re-examine our
method for selecting mergers, and the inherent error budget and systematics
associated with identifying mergers using structure. For galaxies selected by
M_*>10^{10} M_0, the merger fraction can be parameterised by f_m = f_0*(1+z)^m
with the power-law slope m=2.3+/-0.4. By using the best available z = 0 prior
the slope increases to m=3.8+/-0.2, showing how critical the measurement of
local merger properties are for deriving the evolution of the merger fraction.
We furthermore show that the merger fraction derived through structure is
roughly a factor of 3-6 higher than pair fractions. Based on the latest
cosmological simulations of mergers we show that this ratio is predicted, and
that both methods are likely tracing the merger fraction and rate properly. We
calculate, utilising merger time scales from simulations, and previously
published merger fractions that the merger rate of galaxies with M_*>10^{10}
M_0 increases linearly between z = 0.7 and z = 3, and that a typical
M_*>10^{10} M_0 galaxy undergoes between 1-2 major mergers at z<1.2.


title: Subleading-N_c corrections in non-linear small-x evolution

abstract:
  We explore the subleading-N_c corrections to the large-N_c Balitsky-Kovchegov
(BK) evolution equation by comparing its solution to that of the all-N_c
Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK) equation. In
earlier simulations it was observed that the difference between the solutions
of JIMWLK and BK is unusually small for a quark dipole scattering amplitude, of
the order of 0.1%, which is two orders of magnitude smaller than the naively
expected 1/N_c^2 or 11%. In this paper we argue that this smallness is not
accidental. We show that saturation effects and correlator coincidence limits
fixed by group theory constraints conspire with the particular structure of the
dipole kernel to suppress subleading-N_c corrections reducing the difference
between the solutions of JIMWLK and BK to 0.1%. We solve the JIMWLK equation
with improved numerical accuracy and verify that the remaining 1/N_c
corrections, while small, still manage to slow down the rapidity-dependence of
JIMWLK evolution compared to that of BK. We demonstrate that a truncation of
JIMWLK evolution in the form of a minimal Gaussian generalization of the BK
equation captures some of the remaining 1/N_c contributions leading to an even
better agreement with JIMWLK evolution. As the 1/N_c corrections to BK include
multi-reggeon exchanges one may conclude that the net effect of multi-reggeon
exchanges on the dipole amplitude is rather small.


title: Vorton construction and dynamics

abstract:
  Vortons are closed loops of superconducting cosmic strings carrying current
and charge. In this paper we present the first numerical construction of
vortons in the global version of Witten's U(1)xU(1) theory. An energy
minimization procedure is used to compute stationary vortons for a range of
charges and currents, and the associated vorton radius is calculated. It is
found that the standard analysis based on infinite straight cosmic strings does
not provide a good description of the vorton cross-section. The computed
solutions are used as initial conditions in an axially symmetric time evolution
code, which verifies that the solutions are indeed stationary, and are stable
to axially symmetric perturbations. Perturbations which preserve the axial
symmetry excite oscillatory modes and produce an evolution which eventually
returns to a stationary vorton. Finally, the constructed vorton solutions are
used as initial conditions in a full (3+1)-dimensional simulation and an
instability to non-axial perturbations is found. The instability produces a
pinching and bending of the vorton which results in its destruction.


title: WASP-12b: The hottest transiting planet yet discovered

abstract:
  We report on the discovery of WASP-12b, a new transiting extrasolar planet
with $R_{\rm pl}=1.79 \pm 0.09 R_J$ and $M_{\rm pl}=1.41 \pm 0.1 M_J$. The
planet and host star properties were derived from a Monte Carlo Markov Chain
analysis of the transit photometry and radial velocity data. Furthermore, by
comparing the stellar spectrum with theoretical spectra and stellar evolution
models, we determined that the host star is a super-solar metallicity
([M/H]$=0.3^{+0.05}_{-0.15}$), late-F (T$_{\rm eff}=6300^{+200}_{-100}$ K) star
which is evolving off the zero age main sequence. The planet has an equilibrium
temperature of T$_{\rm eq}$=2516 K caused by its very short period orbit
($P=1.09$ days) around the hot, 12th magnitude host star. WASP-12b has the
largest radius of any transiting planet yet detected. It is also the most
heavily irradiated and the shortest period planet in the literature.


title:
Active Absorbing State Phase Transition Beyond Directed Percolation : A
  Class of Exactly Solvable Models

abstract:
  We introduce and solve a model of hardcore particles on a one dimensional
periodic lattice which undergoes an active-absorbing state phase transition at
finite density. In this model an occupied site is defined to be active if its
left neighbour is occupied and the right neighbour is vacant. Particles from
such active sites hop stochastically to their right. We show that, both the
density of active sites and the survival probability vanish as the particle
density is decreased below half. The critical exponents and spatial
correlations of the model are calculated exactly using the matrix product
ansatz. Exact analytical study of several variations of the model reveals that
these non-equilibrium phase transitions belong to a new universality class
different from the generic active-absorbing-state phase transition, namely
directed percolation.


title: Shear stress in lattice Boltzmann simulations

abstract:
  A thorough study of shear stress within the lattice Boltzmann method is
provided. Via standard multiscale Chapman-Enskog expansion we investigate the
dependence of the error in shear stress on grid resolution showing that the
shear stress obtained by the lattice Boltzmann method is second order accurate.
This convergence, however, is usually spoiled by the boundary conditions. It is
also investigated which value of the relaxation parameter minimizes the error.
Furthermore, for simulations using velocity boundary conditions, an artificial
mass increase is often observed. This is a consequence of the compressibility
of the lattice Boltzmann fluid. We investigate this issue and derive an
analytic expression for the time-dependence of the fluid density in terms of
the Reynolds number, Mach number and a geometric factor for the case of a
Poiseuille flow through a rectangular channel in three dimensions. Comparison
of the analytic expression with results of lattice Boltzmann simulations shows
excellent agreement.


title:
Dynamical stability of systems with long-range interactions: application
  of the Nyquist method to the HMF model

abstract:
  We apply the Nyquist method to the Hamiltonian Mean Field (HMF) model in
order to settle the linear dynamical stability of a spatially homogeneous
distribution function with respect to the Vlasov equation. We consider the case
of Maxwell (isothermal) and Tsallis (polytropic) distributions and show that
the system is stable above a critical kinetic temperature T_c and unstable
below it. Then, we consider a symmetric double-humped distribution, made of the
superposition of two decentered Maxwellians, and show the existence of a
re-entrant phase in the stability diagram. When we consider an asymmetric
double-humped distribution, the re-entrant phase disappears above a critical
value of the asymmetry factor Delta>1.09. We also consider the HMF model with a
repulsive interaction. In that case, single-humped distributions are always
stable. For asymmetric double-humped distributions, there is a re-entrant phase
for 1<Delta<25.6, a double re-entrant phase for 25.6<Delta<43.9 and no
re-entrant phase for Delta>43.9. Finally, we extend our results to arbitrary
potentials of interaction and mention the connexion between the HMF model,
Coulombian plasmas and gravitational systems. We discuss the relation between
linear dynamical stability and formal nonlinear dynamical stability and show
their equivalence for spatially homogeneous distributions. We also provide a
criterion of dynamical stability for inhomogeneous systems.


title:
Cooperation in spatial Prisoner's Dilemma with two types of players for
  increasing number of neighbors

abstract:
  We study a spatial two-strategy (cooperation and defection) Prisoner's
Dilemma game with two types ($A$ and $B$) of players located on the sites of a
square lattice. The evolution of strategy distribution is governed by iterated
strategy adoption from a randomly selected neighbor with a probability
depending on the payoff difference and also on the type of the neighbor. The
strategy adoption probability is reduced by a pre-factor ($w < 1$) from the
players of type $B$. We consider the competition between two opposite effects
when increasing the number of neighbors ($k=4$, 8, and 24). Within a range of
the portion of influential players (type $A$) the inhomogeneous activity in
strategy transfer yields a relevant increase (dependent on $w$) in the density
of cooperators. The noise-dependence of this phenomenon is also discussed by
evaluating phase diagrams.


abstract:
  In this paper, Whittaker modules for the Schr\"odinger-Virasoro algebra
$\mathfrak{sv}$ are defined. The Whittaker vectors and the irreducibility of
the Whittaker modules are studied. $\mathfrak{sv}$ has a triangular
decomposition according to the Cartan algebra $\mathfrak{h}:$
$$\mathfrak{sv}=\mathfrak{sv}^{-}\oplus\mathfrak{h}\oplus\mathfrak{sv}^{+}.$$
For any Lie algebra homomorphism $\psi:\mathfrak{sv}^{+}\to\mathbb{C}$, we can
define Whittaker modules of type $\psi.$ When $\psi$ is nonsingular, the
Whittaker vectors, the irreducibility and the classification of Whittaker
modules are completely determined. When $\psi$ is singular, by constructing
some special Whittaker vectors, we find that the Whittaker modules are all
reducible. Moreover, we get some more precise results for special $\psi$.


title:
The pretzelosity distribution function and intrinsic motion of the
  constituents in nucleon

abstract:
  The pretzelosity distribution function $h_{1T}^\perp$ is studied in a
covariant the quark-parton model which describes the structure of the nucleon
in terms of 3D quark intrinsic motion. This relativistic model framework
supports the relation between helicity, transversity and pretzelosity observed
in other relativistic models {\sl without} assuming SU(6) spin-flavor symmetry.
Numerical results and predictions for SIDIS experiments are presented.


title:
A geometric-probabilistic method for counting low-lying states in the
  Bousso-Polchinski Landscape

abstract:
  We propose an accurate method for counting states of close to zero and
positive cosmological constant in the Bousso-Polchinski Landscape. This method
is based on simple geometrical considerations on the high-dimensional lattice
of quantized fluxes and on a probabilistic model (the "random hyperplane"
model) that provides a distribution of the values of the cosmological constant.
Justification of the assumptions made in this model are given by means of
numerical experiments.


title: Search for strange quark matter and Q-balls with the SLIM experiment

abstract:
  We report on the search for Strange Quark Matter (SQM) and charged Q-balls
with the SLIM experiment at the Chacaltaya High Altitude Laboratory (5230 m
a.s.l.) from 2001 to 2005. The SLIM experiment was a 427 m$^{2}$ array of
Nuclear Track Detectors (NTDs) arranged in modules of $24 \times 24$ cm$^{2}$
area. SLIM NTDs were exposed to the cosmic radiation for 4.22 years after which
they were brought back to the Bologna Laboratory where they were etched and
analyzed. We estimate the properties and energy losses in matter of nuclearites
(large SQM nuggets), strangelets (small charged SQM nuggets) and Q-balls; and
discuss their detection with the SLIM experiment. The flux upper limits in the
CR of such downgoing particles are at the level of $1.3 10^{-15}$/cm$^{2}$/s/sr
(90% CL).


title: Chain-Based Representations for Solid and Physical Modeling

abstract:
  In this paper we show that the (co)chain complex associated with a
decomposition of the computational domain, commonly called a mesh in
computational science and engineering, can be represented by a block-bidiagonal
matrix that we call the Hasse matrix. Moreover, we show that
topology-preserving mesh refinements, produced by the action of (the simplest)
Euler operators, can be reduced to multilinear transformations of the Hasse
matrix representing the complex. Our main result is a new representation of the
(co)chain complex underlying field computations, a representation that provides
new insights into the transformations induced by local mesh refinements. Our
approach is based on first principles and is general in that it applies to most
representational domains that can be characterized as cell complexes, without
any restrictions on their type, dimension, codimension, orientability,
manifoldness, connectedness.


title: Dynamical parton distribution functions

abstract:
  Recent measurements for F_2(x,Q^2) have been analyzed in terms of the
`dynamical' and `standard' parton model approach at NLO and NNLO of
perturbative QCD. Having fixed the relevant NLO and NNLO parton distributions,
the implications and predictions for the longitudinal structure function
F_L(x,Q^2) are presented. It is shown that the previously noted extreme
perturbative NNLO/NLO instability of F_L(x,Q^2) is an artifact of the commonly
utilized `standard' gluon distributions. In particular it is demonstrated that
using the appropriate -- dynamically generated -- parton distributions at NLO
and NNLO, F_L(x,Q^2) turns out to be perturbatively rather stable already for
Q^2 \geq O(2-3 GeV^2).


title:
Spectroscopic properties and lattice dynamics of ferroelectric and
  related functional oxide ceramics

abstract:
  Dielectric response as a function of frequency for high-permittivity
dielectric and ferroelectric materials is discussed emphasizing the dynamic
behaviour in the microwave and infrared range. After introducing the usual
modelling of the polar phonon response and anharmonic hopping in locally
dynamically disordered solids, including discussion of displacive and
order-disorder ferroelectric phase transitions, we summarised the experimental
data for selected ferroelectric, incipient ferroelectric and antiferroelectric
perovskite ceramics (STO, BTO, BST, PZO), discussing the dielectric grain size
effect due to a low-permittivity (dead) grain-boundary layer. Other important
structural types of ferroelectrics (Aurivillius compounds SBT, pyrochlores CNO,
PMN) are mentioned, as well. Attention is then paid to relaxor ferroelectrics
(PLZT, PMN, PMT, PST, NBT of perovskite structure and SBN and a novel BLNTN
solid solution system and SLTN of tungsten-bronze structure) and their
extremely broad and complex dielectric dispersion. Then some new results on
magnetoelectric multiferroics (BiFeO3, BiFe_(1/2)Cr_(1/2)O3, EuTiO3) are
summarised and finally our results on microwave ceramics (used for microwave
applications) are noted, discussing mainly the problem of extrapolating the
microwave dielectric properties from the infrared and THz range. A glossary is
added, briefly explaining the meaning of several concepts which might not be
quite familiar for the reader.


title:
Non parametric estimation of the structural expectation of a stochastic
  increasing function

abstract:
  This article introduces a non parametric warping model for functional data.
When the outcome of an experiment is a sample of curves, data can be seen as
realizations of a stochastic process, which takes into account the small
variations between the different observed curves. The aim of this work is to
define a mean pattern which represents the main behaviour of the set of all the
realizations. So we define the structural expectation of the underlying
stochastic function. Then we provide empirical estimators of this structural
expectation and of each individual warping function. Consistency and asymptotic
normality for such estimators are proved.


title: Estimation of the distribution of random shifts deformation

abstract:
  Consider discrete values of functions shifted by unobserved translation
effects, which are independent realizations of a random variable with unknown
distribution $\mu$, modeling the variability in the response of each
individual. Our aim is to construct a nonparametric estimator of the density of
these random translation deformations using semiparametric preliminary
estimates of the shifts. Building on results of Dalalyan et al. (2006),
semiparametric estimators are obtained in our discrete framework and their
performance studied. From these estimates we construct a nonparametric
estimator of the target density. Both rates of convergence and an algorithm to
construct the estimator are provided.


title: Kernel Inverse Regression for spatial random fields

abstract:
  In this paper, we propose a dimension reduction model for spatially dependent
variables. Namely, we investigate an extension of the \emph{inverse regression}
method under strong mixing condition. This method is based on estimation of the
matrix of covariance of the expectation of the explanatory given the dependent
variable, called the \emph{inverse regression}. Then, we study, under strong
mixing condition, the weak and strong consistency of this estimate, using a
kernel estimate of the \emph{inverse regression}. We provide the asymptotic
behaviour of this estimate. A spatial predictor based on this dimension
reduction approach is also proposed. This latter appears as an alternative to
the spatial non-parametric predictor.


title: Local transformation of two EPR photon pairs into a three-photon W state

abstract:
  We propose and experimentally demonstrate a transformation of two EPR photon
pairs distributed among three parties into a three-photon W state using local
operations and classical communication. We then characterize the final state
using quantum state tomography on the three-photon state and on its marginal
bipartite states. The fidelity of the final state to the ideal W state is
$0.778\pm 0.043$ and the expectation value for its witness operator is
$-0.111\pm 0.043$ implying the success of the proposed local transformation.


title:
Realistic sterile neutrino dark matter with keV mass does not contradict
  cosmological bounds

abstract:
  Previous fits of sterile neutrino dark matter models to cosmological data
assumed a peculiar production mechanism, which is not representative of the
best-motivated particle physics models given current data on neutrino
oscillations. These analyses ruled out sterile neutrino masses smaller than
8-10 keV. Here we focus on sterile neutrinos produced resonantly. We show that
their cosmological signature can be approximated by that of mixed Cold plus
Warm Dark Matter (CWDM). We use recent results on LambdaCWDM models to show
that for each mass greater than or equal to 2 keV, there exists at least one
model of sterile neutrino accounting for the totality of dark matter, and
consistent with Lyman-alpha and other cosmological data. Resonant production
occurs in the framework of the nuMSM (the extension of the Standard Model with
three right-handed neutrinos). The models we checked to be allowed correspond
to parameter values consistent with neutrino oscillation data, baryogenesis and
all other dark matter bounds.


title:
Triangular quasi-Hopf algebra structures on certain non-semisimple
  quantum groups

abstract:
  One way to obtain Quantized Universal Enveloping Algebras (QUEAs) of
non-semisimple Lie algebras is by contracting QUEAs of semisimple Lie algebras.
We prove that every contracted QUEA in a certain class is a cochain twist of
the corresponding undeformed universal envelope. Consequently, these contracted
QUEAs possess a triangular quasi-Hopf algebra structure. As examples, we
consider kappa-Poincare in 3 and 4 spacetime dimensions.


title: Plane sextics via dessins d'enfants

abstract:
  We develop a geometric approach to the study of plane sextics with a triple
singular point. As an application, we give an explicit geometric description of
all irreducible maximal sextics with a type $\bold E_7$ singular point and
compute their fundamental groups. All groups found are finite; one of them is
nonabelian.


title:
Approximate conditional distributions of distances between nodes in a
  two-dimensional sensor network

abstract:
  When we represent a network of sensors in Euclidean space by a graph, there
are two distances between any two nodes that we may consider. One of them is
the Euclidean distance. The other is the distance between the two nodes in the
graph, defined to be the number of edges on a shortest path between them. In
this paper, we consider a network of sensors placed uniformly at random in a
two-dimensional region and study two conditional distributions related to these
distances. The first is the probability distribution of distances in the graph,
conditioned on Euclidean distances; the other is the probability density
function associated with Euclidean distances, conditioned on distances in the
graph. We study these distributions both analytically (when feasible) and by
means of simulations. To the best of our knowledge, our results constitute the
first of their kind and open up the possibility of discovering improved
solutions to certain sensor-network problems, as for example sensor
localization.


title:
Persistent fluctuations in the distribution of galaxies from the Two
  degree Field Galaxy Redshift Survey

abstract:
  We apply the scale-length method to several three dimensional samples of the
Two degree Field Galaxy Redshift Survey. This method allows us to map in a
quantitative and powerful way large scale structures in the distribution of
galaxies controlling systematic effects. By determining the probability density
function of conditional fluctuations we show that large scale structures are
quite typical and correspond to large fluctuations in the galaxy density field.
We do not find a convergence to homogeneity up to the samples sizes, i.e. ~ 75
Mpc/h. We then measure, at scales r <~ 40 Mpc/h, a well defined and
statistically stable power-law behavior of the average number of galaxies in
spheres, with fractal dimension D=2.2 +- 0.2. We point out that standard models
of structure formation are unable to explain the existence of the large
fluctuations in the galaxy density field detected in these samples. This
conclusion is reached in two ways: by considering the scale, determined by the
linear perturbation analysis of a self-gravitating fluid, below which large
fluctuations are expected in standard models and through the determination of
statistical properties of mock galaxy catalogs generated from cosmological
N-body simulations of the Millenium consortitum.


title:
Infrared behavior and infinite-volume limit of gluon and ghost
  propagators in Yang-Mills theories

abstract:
  Lattice studies of the infrared behavior of gluon and ghost propagators are a
key probe of confinement scenarios in Yang-Mills theories. However,
finite-volume effects become an important issue as the infrared limit is
approached. By considering general quantities -- namely an associated
susceptibility in the gluon case and properties of the lowest-lying eigenmode
of the Faddeev-Popov matrix in the ghost case -- one can derive rigorous upper
and lower bounds for the propagators. The bounds allow a better control over
the extrapolation of lattice results to the infinite-volume limit. In the case
of the gluon propagator, an intuitive statistical argument suggests a precise
volume dependence for the bounds. This dependence is nicely confirmed by the
lattice data, leading to a finite gluon propagator at zero momentum. At the
same time, an enhancement of the ghost propagator in the infrared limit seems
unlikely. Our analysis is applied to the case of Landau gauge and SU(2) gauge
group, using the largest lattice sizes to date.


title: Flavor Changing Fermion-Graviton Vertices

abstract:
  We study the flavor-changing quark-graviton vertex that is induced at the
one-loop level when gravitational interactions are coupled to the standard
model. Because of the conservation of the energy-momentum tensor the
corresponding form factors turn out to be finite and gauge-invariant.
Analytical expressions of the form factors are provided at leading order in the
external masses. We show that flavor-changing interactions in gravity are local
if the graviton is strictly massless while if the graviton has a small mass
long-range interactions inducing a flavor-changing contribution in the Newton
potential appear. Flavor-changing processes with massive spin-2 particles are
also briefly discussed. These results can be generalized to the case of the
lepton-graviton coupling.


title: Optical M\"{o}bius Singularities

abstract:
  M\"{o}bius strips with one, two, three, and four, half-twists are shown to be
generic features of three-dimensional (nonparaxial) elliptically polarized
light. The geometry and topology of these unusual singularities is described
and the multitude of winding numbers that characterize their structures is
enumerated; probabilities for the appearance of different configurations are
presented.


title:
Dynamic and static density-density correlations in the one-dimensional
  Bose gas: exact results and approximations

abstract:
  We discuss approximate formulas for the dynamic structure factor of the
one-dimensional Bose gas in the Lieb-Liniger model that appear to be applicable
over a wide range of the relevant parameters such as the interaction strength,
frequency, and wavenumber. The suggested approximations are consistent with the
exact results known in limiting cases. In particular, we encompass exact edge
exponents as well as Luttinger liquid and perturbation theoretic results. We
further discuss derived approximations for the static structure factor and the
pair distribution function g(x). The approximate expressions show excellent
agreement with numerical results based on the algebraic Bethe ansatz.


title:
How Interstellar Chemistry (and Astrochemistry More Generally) Became
  Useful

abstract:
  In 1986 Alex Dalgarno published a paper entitled "Is Interstellar Chemistry
Useful?" By the middle 1970s, and perhaps even earlier, Alex had hoped that
astronomical molecules would prove to: possess significant diagnostic utility;
control many of the environments in which they exist; stimulate a wide variety
of physicists and chemists who are at least as fascinated by the mechanisms
forming and removing the molecules as by astronomy. His own research efforts
have contributed greatly to the realization of that hope. This paper contains a
few examples of: how molecules are used to diagnose large-scale dynamics in
astronomical sources including star forming regions and supernovae; the ways in
which molecular processes control the evolution of astronomical objects such as
dense cores destined to become stars and very evolved giant stars; theoretical
and laboratory investigations that elucidate the processes producing and
removing astronomical molecules and allow their detection.


title:
A short answer to critics of our article "Eppur si espande"
  [arXiv:astro-ph/0612155]

abstract:
  Recently [arXiv:astro-ph/0612155] we presented a formal mathematical proof
that, contrary to a widespread misconception, cosmological expansion cannot be
understood as the motion of galaxies in non-expanding space. We showed that the
cosmological redshift must be physically interpreted as the expansion of space.
Although our proof was generally accepted, a few authors disagreed. We rebut
their criticism in this Note.


title: Strongly coupled matter near phase transition

abstract:
  In the Hartree approximation of Cornwall-Jackiw-Tomboulis (CJT) formalism of
the real scalar field theory, we show that for the strongly coupled scalar
system near phase transition, the shear viscosity over entropy density is
small, however, the bulk viscosity over entropy density is large. The large
bulk viscosity is related to the highly nonconformal equation of state. It is
found that the square of the sound velocity near phase transition is much
smaller than the conformal value 1/3, and the trace anomaly at phase transition
deviates far away from 0. These results agree well with the lattice results of
the complex QCD system near phase transition.


title: The strong-coupling limit of lattice Landau gauge

abstract:
  We report on our recent study of the gluon and ghost propagators of pure
SU(2) minimal lattice Landau gauge in the strong-coupling limit. In this limit,
we find evidence of the conformal infrared behaviour of these propagators as
predicted by functional continuum methods. However, in the strong-coupling
limit this happens for lattice momenta with a^2q^2>1, in units of the lattice
spacing a. Deviations from conformal scaling for a^2q^2<1 are well
parameterised by a transverse gluon mass. A comparison of various lattice
definitions of gauge potentials, all equivalent in the continuum limit, shows
that (a) both the critical exponent and coupling can be extracted unambiguously
from the high-momentum data in the strong-coupling limit, in good agreement
with the continuum predictions; but that on the other hand (b) the massive
branch depends on the definition of lattice gluon fields and is thus not
unambiguously defined. We demonstrate that this ambiguity is also present in
the low-momentum region for commonly used values of the lattice coupling in
SU(2).


title: Shear dynamo problem: Quasilinear kinematic theory

abstract:
  Large-scale dynamo action due to turbulence in the presence of a linear shear
flow is studied. Our treatment is quasilinear and kinematic but is non
perturbative in the shear strength. We derive the integro-differential equation
for the evolution of the mean magnetic field, by systematic use of the shearing
coordinate transformation and the Galilean invariance of the linear shear flow.
For non helical turbulence the time evolution of the cross-shear components of
the mean field do not depend on any other components excepting themselves. This
is valid for any Galilean-invariant velocity field, independent of its
dynamics. Hence the shear-current assisted dynamo is essentially absent,
although large-scale non helical dynamo action is not ruled out.


title: Quark mass dependence of the pion vector form factor

abstract:
  We examine the quark mass dependence of the pion vector form factor,
particularly the curvature (mean quartic radius). We focus our study on the
consequences of assuming that the coupling constant of the rho to pions is
largely independent of the quark mass while the quark mass dependence of the
rho--mass is given by recent lattice data. By employing the Omnes
representation we can provide a very clean estimate for a certain combination
of the curvature and the square radius, whose quark mass dependence could be
determined from lattice computations. This study provides an independent access
to the quark mass dependence of the rho-pi-pi coupling and in this way a
non-trivial check of the systematics of chiral extrapolations. We also provide
an improved value for the curvature for physical values for the quark masses,
namely <r^4> = 0.73 +- 0.09 fm^4 or equivalently c_V=4.00\pm 0.50 GeV^{-4}.


title:
Photometric Studies of a WZ Sge-Type Dwarf Nova Candidate,
  ASAS160048-4846.2

abstract:
  We report on our time-resolved CCD photometry during the 2005 June
superoutburst of a WZ Sge-type dwarf nova candidate, ASAS 160048-4846.2. The
ordinary superhumps underwent a complex evolution during the superoutburst. The
superhump amplitude experienced a regrowth, and had two peaks. The superhump
period decreased when the superhump amplitude reached to the first maximum,
successively gradually increased until the second maximum of the amplitude, and
finally decreased again. Investigating other SU UMa-type dwarf novae which show
an increase of the superhump period, we found the same trend of the superhump
evolution in superoutbursts of them. We speculate that the superhump regrowth
in the amplitude has a close relation to the increase of the superhump period,
and all of SU UMa-type dwarf novae with a superhump regrowth follow the same
evolution of the ordinary superhumps as that of ASAS 160048-4846.2.


title:
Evolution of dwarf early-type galaxies I. Spatially resolved stellar
  populations and internal kinematics of Virgo cluster dE/dS0 galaxies

abstract:
  Understanding the origin and evolution of dwarf early-type galaxies remains
an important open issue in modern astrophysics. Internal kinematics of a galaxy
contains signatures of violent phenomena which may have occurred, e.g. mergers
or tidal interactions, while stellar population keeps a fossil record of the
star formation history, therefore studying connection between them becomes
crucial for understanding galaxy evolution. Here, in the first paper of the
series, we present the data on spatially resolved stellar populations and
internal kinematics for a large sample of dwarf elliptical (dE) and lenticular
(dS0) galaxies in the Virgo cluster. We obtained radial velocities, velocity
dispersions, stellar ages and metallicities out to 1--2 half-light radii by
re-analysing already published long-slit and integral-field spectroscopic
datasets using the {\sc NBursts} full spectral fitting technique. Surprisingly,
bright representatives of the dE/dS0 class ($M_B = -18.0 ... -16.0$ mag) look
very similar to intermediate-mass and giant lenticulars and ellipticals: (1)
their nuclear regions often harbour young metal-rich stellar populations always
associated with the drops in the velocity dispersion profiles; (2) metallicity
gradients in the main discs/spheroids vary significantly from nearly flat
profiles to -0.9 dex $r_e^{-1}$, i.e. somewhat 3 times steeper than for typical
bulges; (3) kinematically decoupled cores were discovered in 4 galaxies,
including two with very little, if any, large scale rotation. These results
suggest similarities in the evolutionary paths of dwarf and giant early-type
galaxies and call for reconsidering the role of major mergers in the dE/dS0
evolution.


title: Chemical Potential in the Gravity Dual of a 2+1 Dimensional System

abstract:
  We study probe D5 branes in D3 brane AdS_5 and AdS_5-Schwarzschild
backgrounds as a prototype dual description of strongly coupled 2+1 dimensional
quasi-particles. We introduce a chemical potential through the U(1)_R symmetry
group, U(1) baryon number and a U(1) of isospin in the multi-flavour case. We
find the appropriate D5 embeddings in each case - the embeddings do not exhibit
the spontaneous symmetry breaking that would be needed for a superconductor.
The isospin chemical potential does induce the condensation of charged meson
states.


title: Mass transport of impurities in a moderately dense granular gas

abstract:
  Transport coefficients associated with the mass flux of impurities immersed
in a moderately dense granular gas of hard disks or spheres described by the
inelastic Enskog equation are obtained by means of the Chapman-Enskog
expansion. The transport coefficients are determined as the solutions of a set
of coupled linear integral equations recently derived for polydisperse granular
mixtures [V. Garz\'o, J. W. Dufty and C. M. Hrenya, Phys. Rev. E {\bf 76},
031304 (2007)]. With the objective of obtaining theoretical expressions for the
transport coefficients that are sufficiently accurate for highly inelastic
collisions, we solve the above integral equations by using the second Sonine
approximation. As a complementary route, we numerically solve by means of the
direct simulation Monte Carlo method (DSMC) the inelastic Enskog equation to
get the kinetic diffusion coefficient $D_0$ for two and three dimensions. We
have observed in all our simulations that the disagreement, for arbitrarily
large inelasticity, in the values of both solutions (DSMC and second Sonine
approximation) is less than 4%. Moreover, we show that the second Sonine
approximation to $D_0$ yields a dramatic improvement (up to 50%) over the first
Sonine approximation for impurity particles lighter than the surrounding gas
and in the range of large inelasticity. The results reported in this paper are
of direct application in important problems in granular flows, such as
segregation driven by gravity and a thermal gradient. We analyze here the
segregation criteria that result from our theoretical expressions of the
transport coefficients.


title: Tensor Valued Colombeau Functions on Manifolds

abstract:
  Extending the construction of the (intrinsically defined) full algebra of
scalar valued Colombeau functions on a smooth manifold M (Grosser et al., Adv.
Math. 166 (2002), 179-206) we present a suitable basic space for eventually
obtaining tensor valued generalized functions on M, via the usual quotient
construction. This basic space canonically contains the tensor valued
distributions and permits a natural extension of the classical Lie derivative.
Its members are smooth functions depending - via a third slot - on so-called
transport operators, in addition to slots one (smooth n-forms on M) and two
(points of M) from the scalar case.


title: Delayed coupling theory of vertebrate segmentation

abstract:
  Rhythmic and sequential subdivision of the elongating vertebrate embryonic
body axis into morphological somites is controlled by an oscillating
multicellular genetic network termed the segmentation clock. This clock
operates in the presomitic mesoderm (PSM), generating dynamic stripe patterns
of oscillatory gene-expression across the field of PSM cells. How these spatial
patterns, the clock's collective period, and the underlying cellular-level
interactions are related is not understood. A theory encompassing temporal and
spatial domains of local and collective aspects of the system is essential to
tackle these questions. Our delayed coupling theory achieves this by
representing the PSM as an array of phase oscillators, combining four key
elements: a frequency profile of oscillators slowing across the PSM; coupling
between neighboring oscillators; delay in coupling; and a moving boundary
describing embryonic axis elongation. This theory predicts that the
segmentation clock's collective period depends on delayed coupling. We derive
an expression for pattern wavelength across the PSM and show how this can be
used to fit dynamic wildtype gene-expression patterns, revealing the
quantitative values of parameters controlling spatial and temporal organization
of the oscillators in the system. Our theory can be used to analyze
experimental perturbations, thereby identifying roles of genes involved in
segmentation.

categories: q-bio.MN nlin.AO physics.bio-ph q-bio.TO


title: Gamma Ray Bursts Cook Book I: Formulation

abstract:
  Since the suggestion of relativistic shocks as the origin of gamma-ray bursts
(GRBs) in early 90's, the mathematical formulation of this process has stayed
at phenomenological level. One of the reasons for the slow development of
theoretical works in this domain has been the simple power-law behaviour of the
afterglows hours or days after the prompt gamma-ray emission. Nowadays with the
launch of the Swift satellite, gamma-ray bursts can be observed in
multi-wavelength from a few tens of seconds after trigger onward. These
observations have leaded to the discovery of features unexplainable by the
simple formulation of the shocks and emission processes used up to now. But
"devil is in details" and some of these features may be explained with a more
detailed formulation of phenomena and without adhoc addition of new processes.
Such a formulation is the goal of this work. We present a consistent
formulation of the collision between two spherical relativistic shells. The
model can be applied to both internal and external shocks. Notably, we propose
two phenomenological models for the evolution of the emitting region during the
collision. One of these models is more suitable for the internal shocks and the
other for the external collisions. We calculate radiation flux, lags, and
hardness ratios. One of our aims has been a formulation enough complex to
include the essential processes, but enough simple such that the data can be
directly compared with the theory to extract the value and evolution of
physical quantities. To accomplish this goal, we also suggest a procedure for
extracting parameters of the model from data. In a following paper we
numerically calculate the evolution of some simulated models and compare their
features with the properties of the observed gamma-ray bursts.(abbreviated)


title: A Clebsch-Gordan formula for SL_3 and applications to rationality

abstract:
  If R, S, T are irreducible SL_3-representations, we give an easy and explicit
description of a basis of the space of equivariant maps from R tensor S to T.
We apply this method to the rationality problem for invariant function fields.
In particular, we prove the rationality of the moduli space of plane curves of
degree 34. This uses a criterion which ensures the stable rationality of some
quotients of Grassmannians by an SL-action.


title: Gamma Ray Bursts Cook Book II: Simulation

abstract:
  In Paper I we presented a detailed formulation of the relativistic shocks and
synchrotron emission in the context of Gamma-Ray Burst (GRB) physics. To see
how well this model reproduces the observed characteristics of the GRBs and
their afterglows, here we present the results of some simulations based on this
model. They are meant to reproduce the prompt and afterglow emission in some
intervals of time during a burst. We show that this goal is achieved for both
short and long GRBs and their afterglows, at least for part of the parameter
space. Moreover, these results are the evidence of the physical relevance of
the two phenomenological models we have suggested in Paper I for the evolution
of the {\it active region}, the synchrotron emitting region in a shock. The
dynamical active region model seems to reproduce the observed characteristics
of prompt emissions and late afterglow better than the quasi-steady model which
is more suitable for the onset of afterglows. Therefore these simulations
confirm the arguments presented in Paper I about the behaviour of these models
based on their physical properties.


title: Unveiling the dominant gas heating mechanism in local LIRGs and ULIRGs

abstract:
  We show preliminary results from a sample of Luminous and Ultra-Luminous
Infrared Galaxies (LIRGs and ULIRGs, respectively) in the local universe,
obtained from observations using the Very Large Array (VLA), the Multi-Element
Radio Link Interferometer Network (MERLIN), and the European VLBI Network
(EVN). The main goal of our high-resolution, high-sensitivity radio
observations is to unveil the dominant gas heating mechanism in the central
regions of local (U)LIRGs. The main tracer of recent star-formation in (U)LIRGs
is the explosion of core-collapse supernovae (CCSNe), which are the endproducts
of the explosion of massive stars and yield bright radio events. Therefore, our
observations will not only allow us to answer the question of the dominant
heating mechanism in (U)LIRGs, but will yield also the CCSN rate and the
star-formation rate (SFR) for the galaxies of the sample.


title: A numerical algorithm for zero counting II: Randomization and Condition

abstract: This paper was witdrawn by the authors.


title:
Clarifying the covariant formalism for the SZ effect due to relativistic
  non-thermal electrons

abstract:
  We derive the covariant formalism associated with the relativistic
Sunyaev-Zel'dovich effect due to a non-thermal population of high energy
electrons in clusters of galaxies. More precisely, we show that the formalism
proposed by Wright in 1979, based on an empirical approach (and widely used in
the literature) to compute the inverse Compton scattering of a population of
relativistic electrons on CMB photons, can actually be re-interpreted as a
Boltzmann-like equation, in the single scattering approximation.


title: Pointlike Baryons?

abstract:
  A peculiar feature, observed in the BaBar data on e+e- -> baryon-antibaryon
cross sections, is the non-vanishing cross section at threshold for all these
processes. This is the expectation due to the Coulomb enhancement factor acting
on a charged fermion pair. Remarkably, in the case of e+e- -> p-pbar it is
found that Coulomb final state interactions largely dominate the cross section
at threshold and it turns out a form factor |G(4Mp^2)|~1, as a point-like
fermion. Also in the case of e+e- -> Lambda_c-antiLambda_c, as recently
measured by Belle for the first time, a point-like behavior is suggested for
the charmed charged baryon, being the Lambda_c form factor at threshold |G|~1,
even if within a large error. In the case of neutral strange baryons the
non-vanishing cross section at threshold is interpreted as a remnant of quark
pair Coulomb interaction before the hadronization, taking into account the
asymmetry between attractive and repulsive Coulomb factors. Besides strange
baryon cross sections are successfully compared to U-spin invariance
relationships.


title: Compact Q-balls and Q-shells in a scalar electrodynamics

abstract:
  We investigate spherically symmetric non topological solitons in
electrodynamics with a scalar field self interaction U ~|\psi| taken from the
complex signum-Gordon model. We find Q-balls for small absolute values of the
total electric charge Q, and Q-shells when |Q| is large enough. In both cases
the charge density exactly vanishes outside certain compact region in the three
dimensional space. The dependence of the total energy E of small Q-balls on the
total electric charge has the form E ~ |Q|^(5/6), while in the case of very
large Q-shells E ~ |Q|^(7/6).


title: On Successive Refinement for the Kaspi/Heegard-Berger Problem

abstract:
  Consider a source that produces independent copies of a triplet of jointly
distributed random variables, $\{X_{i},Y_{i},Z_{i}\}_{i=1}^{\infty}$. The
process $\{X_{i}\}$ is observed at the encoder, and is supposed to be
reproduced at two decoders, where $\{Y_{i}\}$ and $\{Z_{i}\}$ are observed, in
either a causal or non-causal manner. The communication between the encoder and
the decoders is carried in two successive stages. In the first stage, the
transmission is available to both decoders and the source is reconstructed
according to the received bit-stream and the individual side information (SI).
In the second stage, additional information is sent to both decoders and the
source reconstructions are refined according to the transmissions at both
stages and the available SI. It is desired to find the necessary and sufficient
conditions on the communication rates between the encoder and decoders, so that
the distortions incurred (at each stage) will not exceed given thresholds. For
the case of non-degraded causal SI at the decoders, an exact single-letter
characterization of the achievable region is derived for the case of pure
source-coding. Then, for the case of communication carried over independent
DMS's with random states known causally/non-causally at the encoder and with
causal SI about the source at the decoders, a single-letter characterization of
all achievable distortion in both stages is provided and it is shown that the
separation theorem holds. Finally, for non-causal degraded SI, inner and outer
bounds to the achievable rate-distortion region are derived. These bounds are
shown to be tight for certain cases of reconstruction requirements at the
decoders, thereby shading some light on the problem of successive refinement
with non-degraded SI at the decoders.


title: Symmetric quasi-hereditary envelopes

abstract:
  We show how any finite-dimensional algebra can be realized as an idempotent
subquotient of some symmetric quasi-hereditary algebra. In the special case of
rigid symmetric algebras we show that they can be realized as centralizer
subalgebras of symmetric quasi-hereditary algebras. We also show that the
infinite-dimensional symmetric quasi-hereditary algebras we construct admit
quasi-hereditary structure with respect to two opposite orders, that they have
strong exact Borel and $\Delta$-subalgebras and the corresponding triangular
decompositions.


title:
Observation of interspecies Feshbach resonances in an ultracold Rb-Cs
  mixture

abstract:
  We report on the observation of interspecies Feshbach resonances in an
ultracold, optically trapped mixture of Rb and Cs atoms. In a magnetic field
range up to 300 G we find 23 interspecies Feshbach resonances in the lowest
spin channel and 2 resonances in a higher channel of the mixture. The
extraordinarily rich Feshbach spectrum suggests the importance of different
partial waves in both the open and closed channels of the scattering problem
along with higher-order coupling mechanisms. Our results provide, on one hand,
fundamental experimental input to characterize the Rb-Cs scattering properties
and, on the other hand, identify possible starting points for the association
of ultracold heteronuclear RbCs molecules.


title:
Evolution by mean curvature in sub-Riemannian geometries: A stochastic
  approach

abstract:
  We study the phenomenon of evolution by horizontal mean curvature flow in
sub-Riemannian geometries. We use a stochastic approach to prove the existence
of a generalized evolution in these spaces. In particular we show that the
value function of suitable family of stochastic control problems solves in the
viscosity sense the level set equation for the evolution by horizontal mean
curvature flow.


title: Supersymmetry breaking in noncommutative quantum mechanics

abstract:
  Supersymmetric quantum mechanics is formulated on a two dimensional
noncommutative plane and applied to the supersymmetric harmonic oscillator. We
find that the ordinary commutative supersymmetry is partially broken and only
half of the number of supercharges are conserved. It is argued that this
breaking is closely related to the breaking of time reversal symmetry arising
from noncommutativity.


title: The Hard X-ray Spectral Evolution in XRBs, AGNs and ULXs

abstract:
  We explore the relationship between the hard X-ray photon index $\Gamma$ and
the Eddington ratio (\xi=L_{X}(0.5-25 keV)/L_{Edd}) in six XRBs. We find that
different XRBs follow different anti-correlations between $\Gamma$ and $\xi$
when $\xi$ is less than a critical value, while they follow the same positive
correlation when $\xi$ is larger than the critical value. This anti-correlation
and positive correlation are also found in LLAGNs and QSOs respectively, and
the anti-correlation and positive correlation of different XRBs roughly
converge to the same point ($\log \xi=-2.1, \Gamma=1.5$), which may correspond
to the accretion mode transition, since that the anti-correlation and positive
correlation are consistent with the prediction of ADAFs and standard
disk/corona system respectively. The traditional low/hard state are divided
into two parts by the cross point $\log \xi\sim-2.1$, i.e., faint-hard state in
the anti-correlation part and bright-hard state in the positive correlation
part. The accretion process in the bright-hard state may be still the standard
accretion disk as that in the high/soft state, which is consistent with that
both the cold disk component and broad Fe K emission line are observed in some
bright-hard state of XRBs. The ADAF is only important in the faint-hard state
XRBs. Motivated by the similarities of the state transition and timing
properties of the ULXs to that of XRBs, we then constrain the BH masses for
seven luminous ULXs assuming that their X-ray spectral evolution is similar to
that of XRBs. We find that the BH masses of these seven ULXs are around
$10^{4}M_sun$, which are typical intermediate mass BHs (IMBHs). Our results are
roughly consistent with the BH masses constrained from the model fitting with a
multi-color disk and/or the timing properties(e.g., QPO and break frequency).


title: Towers of hybrid mesons

abstract:
  A hybrid meson is a quark-antiquark pair in which, contrary to ordinary
mesons, the gluon field is in an excited state. In the framework of constituent
models, the interaction potential is assumed to be the energy of an excited
string. An approximate, but accurate, analytical solution of the
Schr\"{o}dinger equation with such a potential is presented. When applied to
hybrid charmonia and bottomonia, towers of states are predicted in which the
masses are a linear function of a harmonic oscillator band number for the
quark-antiquark pair. Such a formula could be a reliable guide for the
experimental detection of heavy hybrid mesons.


title: Field test of a continuous-variable quantum key distribution prototype

abstract:
  We have designed and realized a prototype that implements a
continuous-variable quantum key distribution protocol based on coherent states
and reverse reconciliation. The system uses time and polarization multiplexing
for optimal transmission and detection of the signal and phase reference, and
employs sophisticated error-correction codes for reconciliation. The security
of the system is guaranteed against general coherent eavesdropping attacks. The
performance of the prototype was tested over preinstalled optical fibres as
part of a quantum cryptography network combining different quantum key
distribution technologies. The stable and automatic operation of the prototype
over 57 hours yielded an average secret key distribution rate of 8 kbit/s over
a 3 dB loss optical fibre, including the key extraction process and all quantum
and classical communication. This system is therefore ideal for securing
communications in metropolitan size networks with high speed requirements.


title:
Matrix product solution of the multispecies partially asymmetric
  exclusion process

abstract:
  We find the exact solution for the stationary state measure of the partially
asymmetric exclusion process on a ring with multiple species of particles. The
solution is in the form of a matrix product representation where the matrices
for a system of N species are defined recursively in terms of the matrices for
a system of N-1 species. A complete proof is given, based on the quadratic
relations verified by these matrices. This matrix product construction is
interpreted in terms of the action of a transfer matrix.


title: Statistical effect in the parton distribution functions of the nucleon

abstract:
  A new and simple statistical approach is performed to calculate the parton
distribution functions (PDFs) of the nucleon in terms of light-front kinematic
variables. We do not put in any extra arbitrary parameter or corrected term by
hand, which guarantees the stringency of our approach. Analytic expressions of
the $x$-dependent PDFs are obtained in the whole $x$ region [0,1], and some
features, especially the low-$x$ rise, are more agreeable with experimental
data than those in some previous instant-form statistical models in the
infinite-momentum frame (IMF). Discussions on heavy-flavored PDFs are also
presented.


title:
Phase-Sensitive measurements on the corner junction of iron-based
  superconductor BaFe1.8Co0.2As2

abstract:
  We have made a phase-sensitive measurement on the corner junction of the
iron-based superconductor BaFe1.8Co0.2As2, and observed the typical
Fraunhofer-like diffraction pattern. The result suggests that there is no phase
shift between the a-c face and b-c face of a crystal, which indicates that the
superconducting wavefunction of the iron based superconductor is different from
that of a cuprate superconductor.


title:
Einstein-Gauss-Bonnet black holes in de Sitter spacetime and the
  quasilocal formalism

abstract:
  We propose to compute the action and global charges of the asymptotically de
Sitter solutions in Einstein-Gauss-Bonnet theory by using the counterterms
method in conjunction with the quasilocal formalism. The general expression of
the counterterms and the boundary stress tensor is presented for spacetimes of
dimension $d\leq 7$. We apply this tehnique for several different solutions in
Einstein-Gauss-Bonnet theory with a positive cosmological constant. Apart from
known solutions, we consider also $d=5$ vacuum rotating black holes with equal
magnitude angular momenta.


title: The POWHEG method applied to top pair production and decays at the ILC

abstract:
  We study the effects of gluon radiation in top pair production and their
decays for e+e- annihilation at the ILC. To achieve this we apply the POWHEG
method and interface our results to the Monte Carlo event generator Herwig++.
We consider a center-of-mass energy of 500GeV and compare decay correlations
and bottom quark distributions before hadronization.


title: Unityped algebras

abstract:
  The paper is essentially a continuation of B.Plotkin, G.Zhitomirski, "Some
logical invariants of algebras and logical relations between algebras",
St.Peterburg Math. J., {19:5}, (2008) 859 -- 879, whose main notion is that of
logic-geometrical equivalence of algebras (LG-equivalence of algebras). This
equivalence of algebras is more strict than elementary equivalence. In the
paper we introduce the notion of unityped algebras and relate it to
LG-equivalence. We show that these notions coincide. The idea of the type is
one of the central ideas in M odel Theory. The correspondence introduced in the
paper stimulates a bunch of problems which connect universal algebraic geometry
and Model Theory. The paper consists of five sections: 1. General view 2.
Logical noetherianity 3. Unitypeness and isomorphism 4. Logically perfect
algebras 5. Some facts from algebraic logic. We provide a new general view on
the subject, arising "on the territory" of universal algebraic geometry, which
yield applications of algebraic logic and universal geometry in Model Theory.


title:
Markovian Monte Carlo program EvolFMC v.2 for solving QCD evolution
  equations

abstract:
  We present the program EvolFMC v.2 that solves the evolution equations in QCD
for the parton momentum distributions by means of the Monte Carlo technique
based on the Markovian process. The program solves the DGLAP-type evolution as
well as modified-DGLAP ones. In both cases the evolution can be performed in
the LO or NLO approximation. The quarks are treated as massless. The overall
technical precision of the code has been established at 0.05% precision level.
This way, for the first time ever, we demonstrate that with the Monte Carlo
method one can solve the evolution equations with precision comparable to the
other numerical methods.


title: Shear banding, aging and noise dynamics in soft glassy materials

abstract:
  The `soft glassy rheology' (SGR) model gives an appealing account of the flow
of nonergodic soft materials in terms of the local yield dynamics of mesoscopic
elements. Newtonian, power-law, and yield-stress fluid regimes arise on varying
a `noise temperature', x. Here we extend the model, to capture the idea that
the noise is largely caused by yield itself. The extended model can account for
the viscosity-bifurcation and shear-banding effects reported recently in a wide
range of soft materials. A variant model may shed light on shear banding and
strain-rate hysteresis seen in glassy star polymer solutions.


title:
Grain Size Influence on Dynamics of Polar Nanoclusters in PMN-35%PT
  Ceramics: Broadband Dielectric and Infrared Spectra

abstract:
  Dielectric response e*(f,T) and polar phonon spectra of coarse grain (grain
size ~ 4 mkm) and fine grain (grain size ~ 150 nm) ceramics of
PbMg_(1/3)Nb_(2/3)O3-35%PbTiO3 were investigated at temperatures 10 - 900 K.
e*(f,T) in coarse-grain ceramics exhibits relaxor behavior at high temperatures
and a sharp anomaly at the ferroelectric phase transition. The fine-grain
ceramics exhibit mainly relaxor ferroelectric behavior with a smaller
dielectric constant. The difference is explained by different relaxational
dynamics of polar nanoclusters, which appear to be more stabilized at high
temperatures in the fine-grain ceramics by pinning at grain boundaries. Below
Tc, the growth of ferroelectric domains is suppressed in fine-grain ceramics as
supported also by a second harmonic generation. On the other hand, polar phonon
frequencies and their temperature dependences are almost independent of the
grain size, but the selection rules for the cubic symmetry are not obeyed and
all phonons are split due to a locally broken symmetry by polar nanoregions and
chemical disorder. The lowest-frequency polar phonon undergoes partial
softening down to ~ 0.1 THz near Tc = 440 K in both ceramics, but the
dielectric anomaly is caused predominantly by flipping and breathing of polar
nanoclusters. Due to contribution of both the soft phonon mode and dielectric
relaxations into the dielectric constant, the ferroelectric phase transition,
which corresponds to the percolation threshold of the polar nanoregions into
macroscopic domains, can be considered as a special case of crossover between
the displacive and order-disorder type.


title:
Adiabatic-connection fluctuation-dissipation density-functional theory
  based on range separation

abstract:
  An adiabatic-connection fluctuation-dissipation theorem approach based on a
range separation of electron-electron interactions is proposed. It involves a
rigorous combination of short-range density functional and long-range random
phase approximations. This method corrects several shortcomings of the standard
random phase approximation and it is particularly well suited for describing
weakly-bound van der Waals systems, as demonstrated on the challenging cases of
the dimers Be$_2$ and Ne$_2$.


title: Wetting failure and contact line dynamics in a Couette flow

abstract:
  Liquid-liquid wetting failure is investigated in a two-dimensional Couette
system with two immiscible fluids of arbitrary viscosity. The problem is solved
exactly using a sharp interface treatment of hydrodynamics (lubrication theory)
as a function of the capillary number, viscous ratio and separation of scale,
i.e. slip length versus macroscopic scale of the system. The existence of
critical velocities, above which no stationary solutions are found, is analyzed
in detail in terms of the relevant parameters of the system. Comparisons with
existing analysis for other geometries are also carried out. A numerical method
of analysis is also presented, based on diffuse interface models obtained from
multiphase extensions of the lattice Boltzmann equation (LBE). Sharp interface
and diffuse interface models are quantitatively compared face to face
indicating the correct limit of applicability of the diffuse interface models.


title: Far-from-equilibrium state in a weakly dissipative model

abstract:
  We address, on the example of a simple solvable model, the issue of whether
the stationary state of dissipative systems converges to an equilibrium state
in the low dissipation limit. We study a driven dissipative Zero Range Process
on a tree, in which particles are interpreted as finite amounts of energy
exchanged between degrees of freedom. The tree structure mimicks the hierarchy
of length scales; energy is injected at the top of the tree ('large scales'),
transferred through the tree and dissipated mostly in the deepest branches of
the tree ('small scales'). Varying a parameter characterizing the transfer
dynamics, a transition is observed, in the low dissipation limit, between a
quasi-equilibrated regime and a far-from-equilibrium one, where the dissipated
flux does not vanish.


title:
Evanescent channels and scattering in cylindrical nanowire
  heterostructures

abstract:
  We investigate the scattering phenomena produced by a general finite-range
nonseparable potential in a multi-channel two-probe cylindrical nanowire
heterostructure. The multi-channel current scattering matrix is efficiently
computed using the R-matrix formalism extended for cylindrical coordinates.
Considering the contribution of the evanescent channels to the scattering
matrix, we are able to put in evidence the specific dips in the tunneling
coefficient in the case of an attractive potential. The cylindrical symmetry
cancels the "selection rules" known for Cartesian coordinates. If the
attractive potential is superposed over a non-uniform potential along the
nanowire, then resonant transmission peaks appear. We can characterize them
quantitatively through the poles of the current scattering matrix. Detailed
maps of the localization probability density sustain the physical
interpretation of the resonances (dips and peaks). Our formalism is applied to
a variety of model systems like a quantum dot, a core/shell quantum ring or a
double-barrier, embedded into the nanocylinder.


title: Worst-Case Optimal Adaptive Prefix Coding

abstract:
  A common complaint about adaptive prefix coding is that it is much slower
than static prefix coding. Karpinski and Nekrich recently took an important
step towards resolving this: they gave an adaptive Shannon coding algorithm
that encodes each character in (O (1)) amortized time and decodes it in (O
(\log H)) amortized time, where $H$ is the empirical entropy of the input
string $s$. For comparison, Gagie's adaptive Shannon coder and both Knuth's and
Vitter's adaptive Huffman coders all use (\Theta (H)) amortized time for each
character. In this paper we give an adaptive Shannon coder that both encodes
and decodes each character in (O (1)) worst-case time. As with both previous
adaptive Shannon coders, we store $s$ in at most ((H + 1) |s| + o (|s|)) bits.
We also show that this encoding length is worst-case optimal up to the lower
order term.


title:
Higher-loop gluon and ghost propagators in Landau gauge from numerical
  stochastic perturbation theory

abstract:
  We present higher loop results for the gluon and ghost propagator in Landau
gauge on the lattice calculated in numerical stochastic perturbation theory. We
make predictions for the perturbative content of those propagators as function
of the lattice momenta for finite lattices. To find out their nonperturbative
contributions, the logarithmic definition of the gauge fields and the
corresponding Faddeev-Popov operator have to be implemented in the Monte Carlo
simulations.


title:
Ferroelectric and Incipient Ferroelectric Properties of a Novel
  Sr_(9-x)PbxCe2Ti2O36 (x=0-9) Ceramic System

abstract:
  Sr_(9-x)PbxCe2Ti12O36 system is derived from the perovskite SrTiO3 and its
chemical formula can be written as (Sr_(1-y)Pby)0.75Ce0.167TiO3. We
investigated dielectric response of Sr_(9-x)PbxCe2Ti12O36 ceramics (x = 0-9)
between 100 Hz and 100 THz at temperatures from 10 to 700 K using low- and
high-frequency dielectric, microwave (MW), THz and infrared spectroscopy. We
revealed that Sr9Ce2Ti12O36 is an incipient ferroelectric with the R-3c
trigonal structure whose relative permittivity e' increases from 167 at 300 K
and saturates near 240 below 30 K. The subsequent substitution of Sr by Pb
enhances e' to several thousands and induces a ferroelectric phase transition
to monoclinic Cc phase for x>=3. Its critical temperature Tc linearly depends
on the Pb concentration and reaches 550 K for x=9. The phase transition is of
displacive type. The soft mode frequency follows the Barrett formula in samples
with x<=2 (typical for quantum paraelectrics) and the Cochran formula for x>=3.
The MW dispersion is lacking and quality factor Q is high in samples with low
Pb concentration, although the permittivity is very high in some cases.
However, due to the lattice softening, the temperature coefficient of the
permittivity is rather high. The best MW quality factor was observed for x=1:
Q*f=5800 GHz and e'=250. Concluding, the dielectric properties of Sr_(9-
x)PbxCe2Ti12O36 are similar to those of Ba_(1-x)SrxTiO3 so that this system can
be presumably used as an alternative for MW devices or capacitors.


title: Evolution of Quantum Criticality in CeNi_{9-x}Cu_xGe_4

abstract:
  Crystal structure, specific heat, thermal expansion, magnetic susceptibility
and electrical resistivity studies of the heavy fermion system
CeNi_{9-x}Cu_xGe_4 (0 <= x <= 1) reveal a continuous tuning of the ground state
by Ni/Cu substitution from an effectively fourfold degenerate non-magnetic
Kondo ground state of CeNi_9Ge_4 (with pronounced non-Fermi-liquid features)
towards a magnetically ordered, effectively twofold degenerate ground state in
CeNi_8CuGe_4 with T_N = 175 +- 5 mK. Quantum critical behavior, C/T ~ \chi ~
-ln(T), is observed for x about 0.4. Hitherto, CeNi_{9-x}Cu_xGe_4 represents
the first system where a substitution-driven quantum phase transition is
connected not only with changes of the relative strength of Kondo effect and
RKKY interaction, but also with a reduction of the effective crystal field
ground state degeneracy.