title: The Stratified Structure of Spaces of Smooth Orbifold Mappings

abstract:
  We consider four notions of maps between smooth C^r orbifolds O, P with O
compact (without boundary). We show that one of these notions is natural and
necessary in order to uniquely define the notion of orbibundle pullback. For
the notion of complete orbifold map, we show that the corresponding set of C^r
maps between O and P with the C^r topology carries the structure of a smooth
C^\infty Banach (r finite)/Frechet (r=infty) manifold. For the notion of
complete reduced orbifold map, the corresponding set of C^r maps between O and
P with the C^r topology carries the structure of a smooth C^\infty Banach (r
finite)/Frechet (r=infty) orbifold. The remaining two notions carry a
stratified structure: The C^r orbifold maps between O and P is locally a
stratified space with strata modeled on smooth C^\infty Banach (r
finite)/Frechet (r=infty) manifolds while the set of C^r reduced orbifold maps
between O and P locally has the structure of a stratified space with strata
modeled on smooth C^\infty Banach (r finite)/Frechet (r=infty) orbifolds.
Furthermore, we give the explicit relationship between these notions of
orbifold map. Applying our results to the special case of orbifold
diffeomorphism groups, we show they inherit the structure of C^\infty Banach (r
finite)/Frechet (r=infty) manifolds. In fact, for r finite they are topological
groups, and for r=infty they are convenient Frechet Lie groups.


title: Dynamics of a self-gravitating magnetized neutron source

abstract:
  The dynamics of a self-gravitating neutron gas in presence of a magnetic
field is being studied taking the equation of state of a magnetized neutron gas
obtained in a previous study [2]. We work in a Bianchi I spacetime
characterized by a Kasner metric, this metric allow us to take into account the
anisotropy that introduces the magnetic field. The set of Einstein-Maxwell
field equations for this gas becomes a dynamical system in a 4-dimensional
phase space. We get numerical solutions of the system. In particular there is a
unique point like solution for different initial conditions. Physically this
singular solution may be associated with the collapse of a local volume of
neutron material within a neutron star.


title: Nonextensive Entropy, Prior PDFs and Spontaneous Symmetry Breaking

abstract:
  We show that using nonextensive entropy can lead to spontaneous symmetry
breaking when a parameter changes its value from that applicable for a
symmetric domain, as in field theory. We give the physical reasons and also
show that even for symmetric Dirichlet priors, such a defnition of the entropy
and the parameter value can lead to asymmetry when entropy is maximized.


title: Searches for exotic X,Y, and Z- states with BABAR

abstract:
  Recently, several charmonium-like states above $D\bar{D}$ threshold have been
discovered at the BELLE and BABAR $B$-factories. Some of these states are
produced via Initial State Radiation ({\it e.g.} Y(4260) and Y(4350)) and some
are observed in $B$ meson decays ({\it{e.g.}} X(3872), Y(3940)). The BELLE
observation of the enhancement in the $\psi(2S)\pi^-$, {\it {i.e.}} the
$Z(4430)^-$ state, has generated a great deal of interest, because such a state
must have minimum quark content ($c\bar{c}d\bar{u}$), so that it would
represent the unequivocal manifestation of a four-quark meson state. Here we
report recent BABAR results on the Y(4260), X(3872), Y(3940), and a search for
the $Z(4430)^-$.


title: Tachyon-Chaplygin inflation on the brane

abstract:
  Tachyon-Brane inflationary universe model in the context of a Chaplygin gas
equation of state is studied. General conditions for this model to be
realizable are discussed. In the high-energy limit and by using an exponential
potential we describe in great details the characteristic of this model. Recent
observational data from the Wilkinson Microwave Anisotropy Probe experiment are
employed to restrict the parameters of the model.


title:
Comments on Baryon-like Operators in N=6 Chern-Simons-matter theory of
  ABJM

abstract:
  We show that baryon-like operators exist in the N=6 superconformal
Chern-Simons-matter theory constructed by Aharony, Bergman, Jafferis and
Maldacena (ABJM). This involves the introduction of Wilson(or 't Hooft) lines
ending on baryon-like operators and we show that the presence of such lines
cannot be detected by the fields in the theory. The same construction can be
used to make magnetic monopoles charged under the diagonal U(1) gauge group
with arbitrary non-integral charge. If we do not include such monopole
configurations in the path integral, the moduli space is known to be given by
the symmetric N copies of C^4/Z_k. However, if we allow for such monopole
configurations, the flux quantization conditions change so that we do not have
a discrete gauge symmetry and effectively the (SU(N)xSU(N))/Z_N gauge theory
remains. We discuss the possibility of the level-rank duality of the theory.


title: Proof of the Julia-Zee Theorem

abstract:
  It is a well accepted principle that finite-energy static solutions in the
classical relativistic gauge field theory over the $(2+1)$-dimensional
Minkowski spacetime must be electrically neutral. We call such a statement the
Julia--Zee theorem. In this paper, we present a mathematical proof of this
fundamental structural property.


title: Holographic Superconductors with Various Condensates

abstract:
  We extend earlier treatments of holographic superconductors by studying cases
where operators of different dimension condense in both 2+1 and 3+1
superconductors. We also compute a correlation length. We find surprising
regularities in quantities such as $\omega_g/T_c$ where $\omega_g$ is the gap
in the frequency dependent conductivity. In special cases, new bound states
arise corresponding to vector normal modes of the dual near-extremal black
holes.


title: Strongly correlated electrons on frustrated lattices

abstract:
  We give an overview of recent work on charge degrees of freedom of strongly
correlated electrons on geometrically frustrated lattices. Special attention is
paid to the checkerboard lattice, i.e., the two-dimensional version of a
pyrochlore lattice and to the kagome lattice. For the checkerboard lattice it
is shown that at half filling when spin degrees of freedom are neglected and
quarter filling when they are included excitations with fractional charges
$\pm$e/2 may exist. The same holds true for the three-dimensional pyrochlore
lattice. In the former case the fractional charges are confined. The origin of
the weak constant confining force is discussed and some similarities to quarks
and to string theory are pointed out. For the checkerboard lattice a
formulation in terms of a compact U(1) gauge theory is described. Furthermore a
new kinetic mechanism for ferromagnetism at special fillings of a kagome
lattice is discussed.


title: Multi-meson States in Lattice QCD

abstract:
  In this contribution, I summarise the studies of the properties of
Bose-Einstein condensed systems composed of up to twelve pions or kaons carried
out by the NPLQCD collaboration. These investigations have provided precise
determination the I=2 pi-pi and I=1 K-K scattering lengths and the first
determination of three-hadron interactions from QCD, finding a repulsive
three-pion interaction of size consistent with naive dimensional analysis and a
three kaon interaction consistent with zero. We have also determined the
isospin (strangeness) density dependence of the isospin (strangeness) chemical
potential, finding results in surprisingly good agreement with chiral
perturbation theory.


title: The Discovery of Diffuse Radio Polarization Structures in the NVSS

abstract:
  We have developed a method for recovering polarization structures from the
NRAO Very Large Array Sky Survey (NVSS) on larger angular scales than the
nominal 15 arc minute survey limit. The technique depends on the existence of
smaller scale fluctuations in polarization angle, to which the interferometer
is sensitive, while the undetected total intensity of the structures can be
arbitrarily large. We recover the large scale structure of the polarized Milky
Way, as seen in single dish surveys, as well as a wide variety of smaller scale
galactic and extragalactic features. We present a brief discussion of the
uncertainties and limitations of the reprocessed NVSS polarization survey, a
comparison of single-dish and NVSS results, and a sampling of the new
polarization structures. We show a companion feature 1.8 Mpc outside of Abell
cluster 3744, apparent Mpc-scale extensions to the tailed radio galaxy 3C31, a
possible new giant galactic loop,and a new bright polarized patch in supernova
remnant CTA1. We note that there is little quantitative information from these
detections, and followup investigations would be necessary to measure reliable
polarized fluxes and position angles. Some of the new features discovered in
this NVSS reanalysis could provide a foreground for CMB polarization studies,
but the internal foreground modeling for the next generation of experiments
should have no difficulty accounting for them.


title: Initial guesses for multi-shift solvers

abstract:
  I will present a method for providing initial guesses to a linear solver for
systems with multiple shifts. This can also be extended to the case of multiple
sources each with a different shift.


title:
General Relativistic Magnetohydrodynamic Simulations of the Hard State
  as a Magnetically-Dominated Accretion Flow

abstract:
  (Abridged) We present one of the first physically-motivated two-dimensional
general relativistic magnetohydrodynamic (GRMHD) numerical simulations of a
radiatively-cooled black-hole accretion disk. The fiducial simulation combines
a total-energy-conserving formulation with a radiative cooling function, which
includes bremsstrahlung, synchrotron, and Compton effects. By comparison with
other simulations we show that in optically thin advection-dominated accretion
flows, radiative cooling can significantly affect the structure, without
necessarily leading to an optically thick, geometrically thin accretion disk.
We further compare the results of our radiatively-cooled simulation to the
predictions of a previously developed analytic model for such flows. For the
very low stress parameter and accretion rate found in our simulated disk, we
closely match a state called the "transition" solution between an outer
advection-dominated accretion flow and what would be a magnetically-dominated
accretion flow (MDAF) in the interior. The qualitative and quantitative
agreement between the numerical and analytic models is quite good, with only a
few well-understood exceptions. According to the analytic model then, at
significantly higher stress or accretion, we would expect a full MDAF to form.
The collection of simulations in this work also provide important data for
interpreting other numerical results in the literature, as they span the most
common treatments of thermodynamics, including simulations evolving: 1) the
internal energy only; 2) the internal energy plus an explicit cooling function;
3) the total energy without cooling; and 4) total energy including cooling. We
find that the total energy formulation is a necessary prerequisite for proper
treatment of radiative cooling in MRI accretion flows.


title: Shearing Expansion-free Spherical Anisotropic Fluid Evolution

abstract:
  Spherically symmetric expansionfree distributions are systematically studied.
The whole set of field equations and junction conditions are presented for a
general distribution of dissipative anisotropic fluid (principal stresses
unequal), and the expansionfree condition is integrated. In order to understand
the physical meaning of expansionfree motion, two different definitions for the
radial velocity of a fluid element are discussed. It is shown that the
appearance of a cavity is inevitable in the expansionfree evolution. The
nondissipative case is considered in detail and the Skripkin model is
recovered.


title:
Distinguishing Newly Born Strange Stars from Neutron Stars with g-Mode
  Oscillations

abstract:
  The gravity-mode (g-mode) eigenfrequencies of newly born strange quark stars
(SQSs) and neutron stars (NSs) are studied. It is found that the
eigenfrequencies in SQSs are much lower than those in NSs by almost one order
of magnitude, since the components of a SQS are all extremely relativistic
particles while nucleons in a NS are non-relativistic. We therefore propose
that newly born SQSs can be distinguished from the NSs by detecting the
eigenfrequencies of the g-mode pulsations of supernovae cores through
gravitational radiation by LIGO-class detectors.


title: Computing topological invariants with one and two-matrix models

abstract:
  A generalization of the Kontsevich Airy-model allows one to compute the
intersection numbers of the moduli space of p-spin curves. These models are
deduced from averages of characteristic polynomials over Gaussian ensembles of
random matrices in an external matrix source. After use of a duality, and of an
appropriate tuning of the source, we obtain in a double scaling limit these
intersection numbers as polynomials in p. One can then take the limit p to -1
which yields a matrix model for orbifold Euler characteristics. The
generalization to a time-dependent matrix model, which is equivalent to a
two-matrix model, may be treated along the same lines ; it also yields a
logarithmic potential with additional vertices for general p.


title: A gap principle for dynamics

abstract:
  Let $f_1,...,f_g\in {\mathbb C}(z)$ be rational functions, let
$\Phi=(f_1,...,f_g)$ denote their coordinatewise action on $({\mathbb P}^1)^g$,
let $V\subset ({\mathbb P}^1)^g$ be a proper subvariety, and let
$P=(x_1,...,x_g)\in ({\mathbb P}^1)^g({\mathbb C})$ be a nonpreperiodic point
for $\Phi$. We show that if $V$ does not contain any periodic subvarieties of
positive dimension, then the set of $n$ such that $\Phi^n(P) \in V({\mathbb
C})$ must be very sparse. In particular, for any $k$ and any sufficiently large
$N$, the number of $n \leq N$ such that $\Phi^n(P) \in V({\mathbb C})$ is less
than $\log^k N$, where $\log^k$ denotes the $k$-th iterate of the $\log$
function. This can be interpreted as an analog of the gap principle of
Davenport-Roth and Mumford.


title:
Stochastic spreading processes on a network model based on regular
  graphs

abstract:
  The dynamic behaviour of stochastic spreading processes on a network model
based on k-regular graphs is investigated. The contact process and the
susceptible-infected-susceptible model for the spread of epidemics are
considered as prototype stochastic spreading processes. We study these on a
network consisting of a mixture of 2- and 3-fold oordinated randomly-connected
nodes of concentration p and 1-p, respectively, with p varying between 0 and 1.
Varying the parameter p from p=0 (3-regular graph of infinite dimension) to p=1
(2-regular graph - 1D chain) allows us to investigate their behaviour under
such structural changes. Both processes are expected to exhibit mean-field
features for p=0 and features typical of the directed percolation universality
class for p=1. The analysis is undertaken by means of Monte Carlo simulations
and the application of mean-field theory. The quasi-stationary simulation
method is used to obtain the phase diagram for the processes in this
environment along with critical exponents. Predictions for critical exponents
obtained from mean-field theory are found to agree with simulation results over
a large range of values for p up to a value of p=0.95, where the system is
found to sharply cross over to the one-dimensional case. Estimates of critical
thresholds given by mean-field theory are found to underestimate the
corresponding critical rates obtained numerically for all values of p.


title:
On the Slope of Hyperelliptic Lefschetz Fibrations and the Number of
  Separating Vanishing Cycles

abstract:
  In this article we find an upper and lower bound for the slope of genus g
hyperelliptic Lefschetz fibrations, which is sharp when g = 2, and demonstrate
the strong connection, in general, between the slope of hyperelliptic genus g
Lefschetz fibrations and the number of separating vanishing cycles.
Specifically, we show that the slope is greater than 4-4/g if and only if the
fibration contains separating vanishing cycles. We also improve the existing
bound on s/n, the ratio of number of separating vanishing cycles to the number
of non-separating vanishing cycles, for hyperelliptic Lefschetz fibrations of
genus g>1. In particular we show that s<=n for such fibrations when g>5.


title:
Prior Emission Model for X-ray Plateau Phase of Gamma-Ray Burst
  Afterglows

abstract:
  The two-component emission model to explain the plateau phase of the X-ray
afterglows of gamma-ray bursts (GRBs) is proposed. One component, which is
responsible for the plateau and subsequent normal decay phase of the X-ray
afterglow, is the prior emission via outflow ejected from the central engine
before the main burst. The other is the main outflow, which causes the prompt
GRB emission and the initial steep decay phase of the X-ray afterglow. In this
model, the transition from the plateau to the subsequent normal decay phase is
an artifact of the choice of the zero of time. For events with distinct plateau
phase, the central engine is active 10^3-10^4 sec before the launch of the main
outflow. According to this model, a prior emission in the X-ray and/or optical
bands 10^3-10^4 sec before the prompt GRB emission is possibly seen, which will
be tested by near-future instruments such as Monitor of All-sky X-ray Image
(MAXI), WIDe-field telescope for GRB Early Timing (WIDGET), and so on.


title: LCDM Satellites and HI Companions - The Arecibo ALFA Survey of NGC 2903

abstract:
  We have conducted a deep, complete HI survey, using Arecibo/ALFA, of a field
centered on the nearby, isolated galaxy, NGC 2903, which is similar to the
Milky Way in its properties. The field size was 150 kpc x 260 kpc and the final
velocity range spanned from 100 to 1133 km/s. The ALFA beams have been mapped
as a function of azimuth and cleaned from each azimuth-specific cube prior to
forming final cubes. The final HI data are sensitive down to an HI mass of 2 x
10^5 Mo and column density of 2 x 10^{17} cm^{-2} at the 3sigma x 2deltaV
level, where sigma is the rms noise level and deltaV is the velocity
resolution. NGC 2903 is found to have an HI envelope that is larger than
previously known, extending to at least 3 times the optical diameter of the
galaxy. Our search for companions yields one new discovery with an HI mass of
2.6 x 10^6 Mo. The companion is 64 kpc from NGC 2903 in projection, is likely
associated with a small optical galaxy of similar total stellar mass, and is
dark matter dominated, with a total mass >10^8 Mo. In the region surveyed,
there are now two known companions: our new discovery and a previously known
system that is likely a dwarf spheroidal, lacking HI content. If HI constitutes
1% of the total mass in all possible companions, then we should have detected
230 companions, according to LCDM predictions. Consequently, if this number of
dark matter clumps are indeed present, then they contain less than 1% HI
content, possibly existing as very faint dwarf spheroidals or as starless,
gasless dark matter clumps.


title: David George Kendall, a biographical account

abstract:
  This biographical account of the life and work of David Kendall includes
details of his personal and professional activities. Kendall is probably best
known for his work in applied probability, especially queueing theory, and in
stochastic analysis and spatial statistics.


title: A microlensing study of the accretion disc in the quasar MG 0414+0534

abstract:
  Observations of gravitational microlensing in multiply imaged quasars
currently provide the only direct probe of quasar emission region structure on
sub-microarcsecond scales. Analyses of microlensing variability are
observationally expensive, requiring long-term monitoring of lensed systems.
Here we demonstrate a technique for constraining the size of the quasar
continuum emission region as a function of wavelength using single-epoch
multi-band imaging. We have obtained images of the lensed quasar MG 0414+0534
in five wavelength bands using the Magellan 6.5-metre Baade telescope at Las
Campanas Observatory, Chile. These data, in combination with two existing
epochs of Hubble Space Telescope data, are used to model the size of the
continuum emission region $\sigma$ as a power-law in wavelength,
$\sigma\propto\lambda^\nu$. We place an upper limit on the Gaussian width of
the $r^\prime$-band emission region of $1.80 \times 10^{16} h_{70}^{-1/2}
(<M>/\rmn{M}_{\odot})^{1/2}$cm, and constrain the power-law index to
$0.77\leq\nu\leq2.67$ (95 per cent confidence range). These results can be used
to constrain models of quasar accretion discs. As a example, we find that the
accretion disc in MG 0414+0534 is statistically consistent with a
Shakura-Sunyaev thin disc model.


title: On the Distribution of the Euler Function of Shifted Smooth Numbers

abstract:
  We give asymptotic formulas for some average values of the Euler function on
shifted smooth numbers. The result is based on various estimates on the
distribution of smooth numbers in arithmetic progressions which are due to A.
Granville and \'E. Fouvry & G. Tenenbaum.


title: Thermodynamic properties of the itinerant-boson ferromagnet

abstract:
  Thermodynamics of a spin-1 Bose gas with ferromagnetic interactions are
investigated via the mean-field theory. It is apparently shown in the specific
heat curve that the system undergoes two phase transitions, the ferromagnetic
transition and the Bose-Einstein condensation, with the Curie point above the
condensation temperature. Above the Curie point, the susceptibility fits the
Curie-Weiss law perfectly. At a fixed temperature, the reciprocal
susceptibility is also in a good linear relationship with the ferromagnetic
interaction.


title: Mass Supply to Galactic Center due to Nested Bars in the Galaxy

abstract:
  We investigate rapid mass supply process by nested bars in the Galaxy by
numerical simulation. We simulate gas flow in the whole galaxy disk with nested
bars, which are the outer bar and the inner bar, especially with highly spatial
resolution in the galactic central region. We assume two cases of inner bar
size which are a smaller one and a larger one than the radius of the 200 pc gas
ring which is corresponds to the Central Molecular Zone. From our numerical
results, in the large size bar cases, the inner bars with large elongation
induce sufficient mass inflow and destroy the 200 pc gas ring. On the other
hand, in the small size bar cases, the inner bars with large elongation induce
large mass inflow and do not destroy the 200 pc gas ring. This mass inflow is
caused by straight shocks excited by the inner bar. In this case, nuclear gas
disks of ~ 15 pc radius are formed. The nuclear gas disks are
self-gravitationally unstable and we expect formation of compact star clusters
under strong tidal force in the nuclear gas disks. We discuss evolution of the
nuclear gas disk.


title: Casimir Energy and Brane Stability

abstract:
  We investigate the role of Casimir energy as a mechanism for brane stability
in five-dimensional models with the fifth dimension compactified on an S^1\Z_2
orbifold, which includes the Randall-Sundrum two brane model (RS1). We employ a
zeta-function regularization technique utilizing the Schwinger proper time
method and the Jacobi theta function identity to calculate the one-loop
effective potential. We show that the combination of the Casimir energies of a
scalar Higgs field, the three generations of Standard Model fermions and one
additional massive non-SM scalar in the bulk produce a non-trivial minimum of
the potential. In particular, we consider a scalar field with a coupling in the
bulk to a Lorentz violating vector particle localized to the compactified
dimension. Such a scalar may provide a natural means of the fine-tuning needed
for stabilization of the brane spearation. Lastly, we briefly review the
possibility that Casimir energy plays a role in generating the currently
observed epoch of cosmological inflation by examining a simple five-dimensional
anisotropic metric.


title:
Simulation of Laser Beam Propagation With a Paraxial Model in a Tilted
  Frame

abstract:
  We study the Schr\"odinger equation which comes from the paraxial
approximation of the Helmholtz equation in the case where the direction of
propagation is tilted with respect to the boundary of the domain. In a first
part, a mathematical analysis is made which leads to an analytical formula of
the solution in the simple case where the refraction index and the absorption
coefficients are constant. Afterwards, we propose a numerical method for
solving the initial problem which uses the previous analytical expression.
Numerical results are presented. We also sketch an extension to a time
dependant model which is relevant for laser plasma interaction.


title:
Constraints on the time variation of the fine structure constant by the
  5-year WMAP data

abstract:
  The constraints on the time variation of the fine structure constant at
recombination epoch relative to its present value, $\Delta\alpha/\alpha \equiv
(\alpha_{\mathrm{rec}} - \alpha_{\mathrm{now}})/\alpha_{\mathrm{now}}$, are
obtained from the analysis of the 5-year WMAP cosmic microwave background data.
As a result of Markov-Chain Monte-Carlo analysis, it is found that, contrary to
the analysis based on the previous WMAP data, the mean value of
$\Delta\alpha/\alpha=-0.0009$ does not change significantly whether we use the
Hubble Space Telescope (HST) measurement of the Hubble parameter as a prior or
not. The resultant 95% confidence ranges of $\Delta\alpha/\alpha$ are $-0.028 <
\Delta\alpha/\alpha < 0.026$ with HST prior and $-0.050 < \Delta\alpha/\alpha <
0.042$ without HST prior.


title:
Dynamics and thermodynamics of a nonlocal Polyakov--Nambu--Jona-Lasinio
  model with running coupling

abstract:
  A nonlocal covariant extension of the two-flavor Nambu and Jona-Lasinio (NJL)
model is constructed, with built-in constraints from the running coupling of
QCD at high-momentum and instanton physics at low-momentum scales. Chiral
low-energy theorems and basic current algebra relations involving pion
properties are shown to be reproduced. The momentum-dependent dynamical quark
mass derived from this approach is in agreement with results from
Dyson-Schwinger equations and lattice QCD. At finite temperature, inclusion of
the Polyakov loop and its gauge invariant coupling to quarks reproduces the
dynamical entanglement of the chiral and deconfinement crossover transitions as
in the (local) PNJL model, but now without the requirement of introducing an
artificial momentum cutoff. Steps beyond the mean-field approximation are made
including mesonic correlations through quark-antiquark ring summations. Various
quantities of interest (pressure, energy density, speed of sound etc.) are
calculated and discussed in comparison with lattice QCD thermodynamics at zero
chemical potential. The extension to finite quark chemical potential and the
phase diagram in the $(T,\mu)$-plane are also discussed.


title: Leonard Euler: addition theorems and superintegrable systems

abstract:
  We consider the Euler approach to construction and to investigation of the
superintegrable systems related to the addition theorems. As an example we
reconstruct Drach systems and get some new two-dimensional superintegrable
Stackel systems.


title: Optical tornadoes in photonic crystals

abstract:
  Based on an optical analogy of spintronics, the generation of optical
tornadoes is theoretically investigated in two-dimensional photonic crystals
without space-inversion symmetry. We address its close relation to the Berry
curvature in crystal momentum space, which represents the non-trivial geometric
property of a Bloch state. It is shown that the Berry curvature is easily
controlled by tuning two types of dielectric rods in a honeycomb photonic
crystal. Then, Bloch states with large Berry curvatures appear as optical
tornadoes in real space. The radiation force of such a configuration is
analyzed, and its possible application is also discussed.


title:
Orientational effect of uniaxially deformed aerogel on the order
  parameter of superfluid $^3He$

abstract:
  Effect of uniaxially-deformed aerogel on orientation of the order parameter
of superfluid $^3He$ is considered. Approach used takes into account
correlations in positions of particles forming aerogel. Calculations show that
for the case of the B-like phase in the uniaxially-stretched aerogel
deformation on the order of $10^{-2}\div10^{-4}$ is already strong enough to
achieve orientation of the order parameter which is different from that
required by magnetic field in bulk liquid. For the A-like phase in
uniaxially-squeezed aerogel the order of magnitude of the orientational effect
is estimated. It is shown that the correlations in positions of particles
forming aerogel has stronger effect on the orientation of the order parameter
than on the transition temperature.


title:
Channel and Multiuser Diversities in Wireless Systems: Delay-Energy
  Tradeoff

abstract:
  We consider a communication system with multi-access fading channel. Each
user in the system requires certain rate guarantee. Our main contribution is to
devise a scheduling scheme called "Opportunistic Super-position Coding" that
satisfies the users' rate requirements. Using mean-field analysis, i.e., when
the number of users go to infinity, we analytically show that the energy
required to guarantee the required user rate can be made as small as required
at the cost of a higher delay ("delay-energy tradeoff"). We explicitly compute
the delay under the proposed scheduling policy and discuss how delay
differentiation can be achieved. We extend the results to multi-band
multi-access channel. Finally, all the results can be generalized in a
straightforward fashion to broadcast channel due to the AWGN
multiaccess-broadcast duality.


title:
Determining the heavy seesaw neutrino mass matrix from low-energy
  parameters

abstract:
  We explore how the seesaw sector in neutrino mass models may be constrained
through symmetries to be completely determined in terms of low-energy mass,
mixing angle and CP-violating phase observables. The key ingredients are
intra-family symmetries to determine the neutrino Dirac mass matrix in terms of
the charged-lepton or quark mass matrices, together with inter-family or flavor
symmetries to determine diagonalization matrices. Implications for leptogenesis
and collider detection of heavy neutral leptons are discussed. We show that
leptogenesis can succeed in small regions of parameter space for the case where
the neutrino Dirac mass matrix equals the up-quark mass matrix. The model where
the neutrino Dirac mass matrix equals the charged-lepton mass matrix can yield
a heavy neutral lepton as light as about 1 TeV, but detecting such a particle
will be difficult.


title:
Low-Density Parity-Check Codes Which Can Correct Three Errors Under
  Iterative Decoding

abstract:
  In this paper, we give necessary and sufficient conditions for low-density
parity-check (LDPC) codes with column-weight three to correct three errors when
decoded using hard-decision message-passing decoding. Additionally, we give
necessary and sufficient conditions for column-weight-four codes to correct
three errors in four iterations of hard-decision message-passing decoding. We
then give a construction technique which results in codes satisfying these
conditions. We also provide numerical assessment of code performance via
simulation results.


title: On the expressiveness of single-pass instruction sequences

abstract:
  We perceive programs as single-pass instruction sequences. A single-pass
instruction sequence under execution is considered to produce a behaviour to be
controlled by some execution environment. Threads as considered in basic thread
algebra model such behaviours. We show that all regular threads, i.e. threads
that can only be in a finite number of states, can be produced by single-pass
instruction sequences without jump instructions if use can be made of Boolean
registers. We also show that, in the case where goto instructions are used
instead of jump instructions, a bound to the number of labels restricts the
expressiveness.


title:
Vanishing hardness-flux correlation in Cygnus X-1: signs of the disc
  moving out

abstract:
  Aims. We investigate observations of the X-ray binary Cygnus X-1 with
unusually high hardness and low flux. In particular, we study the
characteristic frequencies seen in the PDS and the hardness-flux correlation
within and between these observations.
  Methods. We analyse observations of Cyg X-1 during periods when the source
reaches its highest hardness levels (> 1 for the 9-20 keV over 2-4 keV RXTE/PCA
count ratios, corresponding to Gamma < 1.6). Using the relativistic precession
model to interpret the PDS we estimate a value for the inner radius of the
accretion disc. We also study the hardness-flux correlation.
  Results. In the selected observations, the characteristic frequencies seen in
the power spectrum are shifted to the lowest end of their frequency range.
Within a single observation, the hardness-flux correlation is very weak,
contrary to the negative correlation normally observed in the hard state. We
suggest that this could be interpreted as the inner disc boundary being at
large radii (> 50 Rg), thereby requiring more time to adjust to a changing
accretion rate than allowed by a single RXTE observation, and compare our
findings to estimates of the viscous time scale responsible for small scale
variability in the system.


title: On the Mathematics of the Law of Mass Action

abstract:
  In 1864,Waage and Guldberg formulated the "law of mass action." Since that
time, chemists, chemical engineers, physicists and mathematicians have amassed
a great deal of knowledge on the topic. In our view, sufficient understanding
has been acquired to warrant a formal mathematical consolidation. A major goal
of this consolidation is to solidify the mathematical foundations of mass
action chemistry -- to provide precise definitions, elucidate what can now be
proved, and indicate what is only conjectured. In addition, we believe that the
law of mass action is of intrinsic mathematical interest and should be made
available in a form that might transcend its application to chemistry alone. We
present the law of mass action in the context of a dynamical theory of sets of
binomials over the complex numbers.


title:
Characterization of Fault Roughness at Various Scales: Implications of
  Three-Dimensional High Resolution Topography Measurements

abstract:
  Accurate description of the topography of active faults surfaces represents
an important geophysical issue because this topography is strongly related to
the stress distribution along fault planes, and therefore to processes
implicated in earthquake nucleation, propagation, and arrest. With the recent
development of Light Detection And Ranging (LIDAR) apparatus, it is now
possible to measure accurately the 3D topography of rough surfaces with a
comparable resolution in all directions, both at field and laboratory scales.
In the present study, we have investigated the scaling properties including
possible anisotropy properties of several outcrops of two natural fault
surfaces (Vuache strike-slip fault, France, and Magnola normal fault, Italy) in
limestones.


title:
Auto-oscillation threshold and line narrowing in MgO-based spin-torque
  oscillators

abstract:
  We present an experimental study of the power spectrum of current-driven
magnetization oscillations in MgO tunnel junctions under low bias. We find the
existence of narrow spectral lines, down to 8 MHz in width at a frequency of
10.7 GHz, for small applied fields with clear evidence of an auto-oscillation
threshold. Micromagnetics simulations indicate that the excited mode
corresponds to an edge mode of the synthetic antiferromagnet.


title: Fluid Flower : Microliquid Patterning via Drop Impact

abstract:
  In microfluidic technologies, direct patterning of liquid without resorting
to micromachined solid structures has various advantages including reduction of
the frictional dissipation and the fabrication cost. This fluid dynamics video
illustrates the method to micropattern a liquid on a solid surface with drop
impact. We experimentally show that a water drop impacting with the
wettability-patterned solid retracts fast on the hydrophobic regions while
being arrested on the hydrophilic areas.


title:
How to compute the thermal quarkonium spectral function from first
  principles?

abstract:
  In the limit of a high temperature T and a large quark-mass M, implying a
small gauge coupling g, the heavy quark contribution to the spectral function
of the electromagnetic current can be computed systematically in the
weak-coupling expansion. We argue that the scale hierarchy relevant for
addressing the disappearance ("melting") of the resonance peak from the
spectral function reads M >> T > g^2 M > gT >> g^4 M, and review how the heavy
scales can be integrated out one-by-one, to construct a set of effective field
theories describing the low-energy dynamics. The parametric behaviour of the
melting temperature in the weak-coupling limit is specified.


title: Fluctuation Theorem in a Quantum-Dot Aharonov-Bohm Interferometer

abstract:
  In the present study, we investigate the full counting statistics in a
two-terminal Aharonov-Bohm interferometer embedded with an interacting quantum
dot. We introduce a novel saddle-point solution for a cumulant-generating
function, which satisfies the fluctuation theorem and accounts for the
interaction in the mean-field level approximation. Nonlinear transport
coefficients satisfy universal relations imposed by microscopic reversibility,
though the scattering matrix itself is not reversible. The skewness can be
finite even in equilibrium, owing to the interaction and is proportional to the
asymmetric component of nonlinear conductance.


title: Noncommutative coordinate algebras

abstract:
  We discuss the noncommutative generalizations of polynomial algebras which
after appropriate completions can be used as coordinate algebras in various
noncommutative settings, (noncommutative differential geometry, noncommutative
algebraic geometry, etc.). These algebras have finite presentations and are
completely characterized and classified by their (noncommutative) volume forms.

categories: math.QA gr-qc hep-th math-ph math.MP math.RA


title: Three-quark systems in MA and MC projected QCD

abstract:
  We study three quark systems in Maximally Abelian (MA) and Maximal Center
(MC) projected QCD on quenched SU(3) lattice, and also in the monopole/photon
part, where only the color-electric/magnetic current exists, using the Hodge
decomposition. First, we perform the quantitative study of the three-quark (3Q)
potential V_{3Q} and the string tension \sigma_{3Q} in baryons. For MA
projected QCD, the monopole part and MC projected QCD, we find that the
confinement potential in V_{3Q} obeys the Y-Ansatz and the string tension
\sigma_{3Q} is approximately equal to that in SU(3) QCD. The universality of
the string tension, \sigma_{3Q} \simeq \sigma_{Q\bar Q}, is also found between
the 3Q and the Q\bar Q potentials. We find a strong similarity of the
inter-quark potential between the monopole part and MC projected QCD. In
contrast, almost no confinement force is found in the inter-quark potential in
the photon part. Next, we study the spectrum of light hadrons in MA projected
QCD and the monopole/photon part, paying attention to the N-\Delta mass
splitting. We find that the N-\Delta mass splitting is significantly reduced in
MA projected QCD and the monopole part, where the one-gluon-exchange effect or
the Coulomb-potential part is largely reduced due to the Abelianization or the
Hodge decomposition. This fact seems to indicate that the main origin of the
mass splitting is one-gluon exchange.


title: Starburst triggered by compressive tides in galaxy mergers

abstract:
  The tidal field of galaxies is known generally to be disruptive. However, in
the case of galaxy mergers, a compressive mode of tidal wave may develop and
last long enough to cocoon the formation of star clusters. Using an N-body
simulation of the Antennae galaxies, we derive the positions of these
compressive regions and the statistics of their duration. Excellent agreement
between the spatial distribution of tides and observed young clusters is found,
while the characteristic e-folding times of 10 to 30 Myrs derived for the tidal
field compare well with cluster formation time-scales.


title:
Multicanonical Algorithm, Simulated Tempering, Replica-Exchange Method,
  and All That

abstract:
  We discuss multi-dimensional generalizations of multicanonical algorithm,
simulated tempering, and replica-exchange method. We generalize the original
potential energy function $E_0$ by adding any physical quantity $V$ of interest
as a new energy term with a coupling constant $\lambda$. We then perform a
multi-dimensional multicanonical simulation where a random walk in $E_0$ and
$V$ space is realized. We can alternately perform a multi-dimensional simulated
tempering simulation where a random walk in temperature $T$ and parameter
$\lambda$ is realized. The results of the multi-dimensional replica-exchange
simulations can be used to determine the weight factors for these
multi-dimensional multicanonical and simulated tempering simulations.


title:
Interstellar Plasma Turbulence Spectrum Toward the Pulsars PSR B0809+74
  and B0950+08

abstract:
  Interstellar scintillations of pulsars PSR B0809+74 and B0950+08 have been
studied using observations at low frequencies (41, 62, 89, and 112 MHz).
Characteristic temporal and frequency scales of diffractive scintillations at
these frequencies have been determined. The comprehensive analysis of the
frequency and temporal structure functions reduced to the same frequency has
shown that the spectrum of interstellar plasma inhomogeneities toward both
pulsars is described by a power law. The exponent of the spectrum of
fluctuations of interstellar plasma inhomogeneities toward PSR B0950+08 (n =
3.00 +- 0.05) appreciably differs from the Kolmogorov exponent. Toward PSR
B0809+74 the spectrum is a power law with an exponent n = 3.7 +- 0.1. A strong
angular refraction has been detected toward PSR B0950+08. The distribution of
inhomogeneities along the line of sight has been analyzed; it has been shown
that the scintillations of PSR B0950+08 take place on a turbulent layer with
enhanced electron density, which is localized at approximately 10 pc from the
observer. For PSR B0809+74 the distribution of inhomogeneities is
quasi-uniform. Mean-square fluctuations of electron density on inhomogeneities
with a characteristic scale rho_0 = 10^7 m toward four pulsars have been
estimated. On this scale the local turbulence level in the 10-pc layer is 20
times higher than in an extended region responsible for the scintillations of
PSR B0809+74.


title:
Gaussian Belief Propagation for Solving Systems of Linear Equations:
  Theory and Application

abstract:
  The canonical problem of solving a system of linear equations arises in
numerous contexts in information theory, communication theory, and related
fields. In this contribution, we develop a solution based upon Gaussian belief
propagation (GaBP) that does not involve direct matrix inversion. The iterative
nature of our approach allows for a distributed message-passing implementation
of the solution algorithm. We address the properties of the GaBP solver,
including convergence, exactness, computational complexity, message-passing
efficiency and its relation to classical solution methods. We use numerical
examples and applications, like linear detection, to illustrate these
properties through the use of computer simulations. This empirical study
demonstrates the attractiveness (e.g., faster convergence rate) of the proposed
GaBP solver in comparison to conventional linear-algebraic iterative solution
methods.


title:
Quasi-local variables and inhomogeneous cosmological sources with
  spherical symmetry

abstract:
  We examine a large class of inhomogeneous spherically symmetric spacetimes
that generalize the Lemaitre-Tolman-Bondi dust solutions to nonzero pressure
("LTB spacetimes"). Local covariant LTB objects can be expressed as
perturbations of covariant quasi-local (QL) scalars that satisfy evolution
equations of equivalent Friedman-Lemaitre-Robertson-Walker (FLRW) scalars.
Thus, the dynamics of these spacetimes can be rigorously described as
non-linear, gauge invariant and covariant perturbations on a formal FLRW
background given by the QL scalars. Since LTB spacetimes are compatible with a
wide variety of "equations of state" and theoretical assumptions, they provide
an ideal framework for numerical models of cosmological sources under idealized
but fully non-linear conditions. As an illustrative example, we briefly examine
the formation of a black hole in an expanding Chaplygin gas universe.


title: The synchronization transition in correlated oscillator populations

abstract:
  The synchronization transition of correlated ensembles of coupled Kuramoto
oscillators on sparse random networks is investigated. Extensive numerical
simulations show that correlations between the native frequencies of adjacent
oscillators on the network systematically shift the critical point as well as
the critical exponents characterizing the transition. Negative correlations
imply an onset of synchronization for smaller coupling, whereas positive
correlations shift the critical coupling towards larger interaction strengths.
For negatively correlated oscillators the transition still exhibits critical
behaviour similar to the all-to-all coupled Kuramoto system, while positive
correlations change the universality class of the transition depending on the
correlation strength. Crucially, the paper demonstrates that the
synchronization behaviour is not only determined by the coupling architecture,
but is also strongly influenced by the oscillator placement on the coupling
network.


title: Zeros of Systems of ${\mathfrak p}$-adic Quadratic Forms

abstract:
  It is shown that a system of $r$ quadratic forms over a ${\mathfrak p}$-adic
field has a non-trivial common zero as soon as the number of variables exceeds
$4r$, providing that the residue class field has cardinality at least $(2r)^r$.


title: Volume entropy of Hilbert Geometries

abstract:
  It is shown that the volume entropy of a Hilbert geometry associated to an
$n$-dimensional convex body of class $C^{1,1}$ equals $n-1$. To achieve this
result, a new projective invariant of convex bodies, similar to the
centro-affine area, is constructed. In the case $n=2$, and without any
assumption on the boundary, it is shown that the entropy is bounded above by
$\frac{2}{3-d} \leq 1$, where $d$ is the Minkowski dimension of the extremal
set of $K$. An example of a plane Hilbert geometry with entropy strictly
between 0 and 1 is constructed.


title:
Near-threshold $\phi$ meson production in proton-nucleus reactions and
  $\phi$ width in finite nuclei

abstract:
  In the framework of the nuclear spectral function approach for incoherent
primary proton-nucleon and secondary pion-nucleon production processes we study
the inclusive $\phi$ meson production in the interaction of 2.83 GeV protons
with nuclei. In particular, the A- and momentum-dependences of the absolute and
relative phi meson yields are investigated within the different scenarios for
its in-medium width. Our model calculations take into account the acceptance
window of the ANKE facility used in a recent experiment performed at COSY. They
show that the pion-nucleon production channel contributes distinctly to the
"low-momentum" $\phi$ creation in heavy nuclei in the chosen kinematics and,
hence, has to be taken into consideration on close examination of the
dependences of the phi meson yields on the target mass number with the aim to
get information on its width in the medium.


title:
Water-wave gap solitons: An approximate theory and accurate numerical
  experiments

abstract:
  It is demonstrated that a standard coupled-mode theory can successfully
describe weakly-nonlinear gravity water waves in Bragg resonance with a
periodic one-dimensional topography. Analytical solutions for gap solitons
provided by this theory are in a reasonable agreement with accurate numerical
simulations of exact equations of motion for ideal planar potential
free-surface flows, even for strongly nonlinear waves. In numerical
experiments, self-localized groups of nearly standing water waves can exist up
to hundreds of wave periods. Generalizations of the model to the
three-dimensional case are also derived.


title: Spectra of Ruelle transfer operators for Axiom A flows (Revised)

abstract:
  For Axiom A flows on basic sets satisfying certain additional conditions we
prove strong spectral estimates for Ruelle transfer operators similar to these
of Dolgopyat (1998) for geodesic flows on compact surfaces (for general
potentials)and transitive Anosov flows on compact manifolds with C^1 jointly
non-integrable horocycle foliations (for the Sinai-Bowen-Ruelle potential).
Here we deal with general potentials. As is now well known, such results have
deep implications in some related areas, e.g. in studying analytic properties
of Ruelle zeta functions and partial differential operators, closed orbit
counting functions, decay of correlations for H\"older continuous potentials.


title:
A robust spectral method for finding lumpings and meta stable states of
  non-reversible Markov chains

abstract:
  A spectral method for identifying lumping in large Markov chains is
presented. Identification of meta stable states is treated as a special case.
The method is based on spectral analysis of a self-adjoint matrix that is a
function of the original transition matrix. It is demonstrated that the
technique is more robust than existing methods when applied to noisy
non-reversible Markov chains.


title: Ground state solutions for the nonlinear Klein-Gordon-Maxwell equations

abstract:
  In this paper we prove the existence of a ground state solution for the
nonlinear Klein-Gordon-Maxwell equations in the electrostatic case.


title:
Lattice simulation of a center symmetric three-dimensional effective
  theory for SU(2) Yang-Mills

abstract:
  We perform simulations of an effective theory of SU(2) Wilson lines in three
dimensions. Our action includes a kinetic term, the one-loop perturbative
potential for the Wilson line, a non-perturbative "fuzzy-bag" contribution and
spatial gauge fields. We determine the phase diagram of the theory and confirm
that, at moderately weak coupling, the non-perturbative term leads to
eigenvalue repulsion in a finite region above the deconfining phase transition.


title: (G,m)-multiparking functions

abstract:
  The conceptions of $G$-parking functions and $G$-multiparking functions were
introduced in [15] and [12] respectively. In this paper, let $G$ be a connected
graph with vertex set $\{1,2,...,n\}$ and $m\in V(G)$. We give the definition
of $(G,m)$-multiparking function. This definition unifies the conceptions of
$G$-parking function and $G$-multiparking function. We construct bijections
between the set of $(G,m)$-multiparking functions and the set of
$\mathcal{F}_{G,m}$ of spanning color $m$-forests of $G$. Furthermore we define
the $(G,m)$-multiparking complement function, give the reciprocity theorem for
$(G,m)$-multiparking function and extend the results [25,12] to
$(G,m)$-multiparking function. Finally, we use a combinatorial methods to give
a recursion of the generating function of the sum $\sum\limits_{i=1}^na_i$ of
$G$-parking functions $(a_1,...,a_n)$.


title: Block renormalization group transformations and overlap fermions

abstract:
  In this preliminary work, I provide the outline of an argument (leaving the
full proof to a future publication) that there exists a valid renormalization
group blocking transformation which converts the continuum fermion action into
a Ginsparg-Wilson lattice action. I construct the blocking for the massless
overlap operator as a specific example, indicating how other Ginsparg-Wilson
lattice Dirac operators can be derived in a similar fashion. This
renormalization group transformation modifies the gauge action and adds a
number of irrelevant terms to the lattice action. The procedure is not valid
for lattice Dirac operators which do not exactly satisfy the Ginsparg-Wilson
relation, for example the Wilson operator.


title:
Maximally Radio-Disjoint Multipath Routing for Wireless Multimedia
  Sensor Networks

abstract:
  In wireless sensor networks, bandwidth is one of precious resources to
multimedia applications. To get more bandwidth, multipath routing is one
appropriate solution provided that inter-path interferences are minimized. In
this paper, we address the problem of interfering paths in the context of
wireless multimedia sensor networks and consider both intra-session as well as
inter-session interferences. Our main objective is to provide necessary
bandwidth to multimedia applications through non-interfering paths while
increasing the network lifetime. To do so, we adopt an incremental approach
where for a given session, only one path is built at once. Additional paths are
built when required, typically in case of congestion or bandwidth shortage.
Interference awareness and energy saving are achieved by switching a subset of
sensor nodes in a {\em passive state} in which they do not take part in the
routing process. Despite the routing overhead introduced by the incremental
approach we adopt, our simulations show that this can be compensated by the
overall achieved throughput and the amount of consumed energy per correctly
received packet especially for relatively long sessions such as multimedia
ones. This is mainly due to the fact that a small number of non-interfering
paths allows for better performances than a large number of interfering ones.


title: Quarkonium Production Studies in CMS

abstract:
  When the LHC starts its operation, CMS will have a unique opportunity to
study q uarkonium production in pp collisions and later in PbPb collisions.
Here we report on the methods and plans for measuring the differential pT
Jpsi->mu+mu- production cross section, using data to be collected in the first
LHC run by the CMS detector. Furthermore we discuss the performance of the CMS
detector for quarkonium measurements in PbPb collisions.


title: Precise dispersive data analysis of the f0(600) pole

abstract:
  We review how the use of recent precise data on kaon decays together with
forward dispersion relations (FDR) and Roy's equations allow us to determine
the sigma resonance pole position very precisely, by using only experimental
input. In addition, we present preliminary results for a modified set of
Roy-like equations with only one subtraction, that show a remarkable
improvement in the precision around the sigma region. We also improve the
matching between the parametrizations at low and intermediate energy of the S0
wave, and show that the effect of this on the sigma pole position is
negligible.


title: Compatible Complex Structures on Twistor Spaces

abstract:
  Let (M,g) be a Riemannian 4-manifold. The twistor space Z->M is a CP1-bundle
whose total space Z admits a natural metric h. The aim of this article is to
study properties of complex structures on (Z,h) which are compatible with the
CP1-fibration and the metric h. The results obtained enable us to translate
some metric properties on M in terms of complex properties on its twistor space
Z.


title: Colloidal stability of tannins: astringency, wine tasting and beyond

abstract:
  Tannin-tannin and tannin-protein interactions in water-ethanol solvent
mixtures are studied in the context of red wine tasting. While tannin
self-aggregation is relevant for visual aspect of wine tasting (limpidity and
related colloidal phenomena), tannin affinities for salivary proline-rich
proteins is fundamental for a wide spectrum of organoleptic properties related
to astringency. Tannin-tannin interactions are analyzed in water-ethanol
wine-like solvents and the precipitation map is constructed for a typical grape
tannin. The interaction between tannins and human salivary proline-rich
proteins (PRP) are investigated in the framework of the shell model for
micellization, known for describing tannin-induced aggregation of beta-casein.
Tannin-assisted micellization and compaction of proteins observed by SAXS are
described quantitatively and discussed in the case of astringency.


title: Ionization Quenching Factor Measurement of Helium 4

abstract:
  The ionization quenching factor (IQF) is defined as the fraction of energy
released by a recoil in a medium through ionization compared with its total
kinetic energy. At low energies, in the range of a few keV, the ionization
produced in a medium falls rapidly and systematic measurements are needed. We
report measurements carried out at such low energies as a function of the
pressure in He4 at 350, 700, 1000 and 1300 mbar. In order to produce a nucleus
moving with a controlled energy in the detection volume, we have developed an
Electron Cyclotron Resonance Ion Source (ECRIS) coupled to an ionization
chamber by a differential pumping. The quenching factor of He4 has been
measured for the first time down to 1 keV recoil energies. An important
deviation with respect to the phenomenological calculations has been found
allowing an estimation of the scintillation produced in He4 as a function of
pressure. The variation of the IQF as a function of the percentage of
isobutane, used as quencher, is also presented.


title:
Hadronic Production of Colored SUSY Particles with Electroweak NLO
  Contributions

abstract:
  We consider the production of squarks and gluinos at hadronic colliders. An
overview over the class of processes is given. We investigate in detail the
tree-level and higher order EW contributions to the cross sections. Special
care has to be taken to obtain infrared finite observables. We study
numerically stop--anti-stop and squark--gluino production at the LHC.


title:
Load Repartition for Congestion Control in Multimedia Wireless Sensor
  Networks with Multipath Routing

abstract:
  Wireless sensor networks hold a great potential in the deployment of several
applications of a paramount importance in our daily life. Video sensors are
able to improve a number of these applications where new approaches adapted to
both wireless sensor networks and video transport specific characteristics are
required. The aim of this work is to provide the necessary bandwidth and to
alleviate the congestion problem to video streaming. In this paper, we
investigate various load repartition strategies for congestion control
mechanism on top of a multipath routing feature. Simulations are performed in
order to get insight into the performances of our proposals.


title:
A 42.3-43.6 GHz spectral survey of Orion BN/KL: First detection of the
  v=0 J=1-0 line from the isotopologues 29SiO and 30SiO

abstract:
  We have surveyed molecular line emission from Orion BN/KL from 42.3 to 43.6
GHz with the Green Bank Telescope. Sixty-seven lines were identified and
ascribed to 13 different molecular species. The spectrum at 7 mm is dominated
by SiO, SO2, CH3OCH3, and C2H5CN. Five transitions have been detected from the
SiO isotopologues 28SiO, 29SiO, and 30SiO.
  We report here for the first time the spectra of the 29SiO and 30SiO v=0
J=1-0 emission in Orion BN/KL, and we show that they have double-peaked
profiles with velocity extents similar to the main isotopologue. The main
motivation for the survey was the search of high-velocity (100-1000 km/s)
outflows in the BN/KL region as traced by SiO Doppler components. Some of the
unidentified lines in principle could be high-velocity SiO features, but
without imaging data their location cannot be established.
  Wings of emission are present in the v=0 28SiO, 29SiO and 30SiO profiles, and
we suggest that the v=0 emission from the three isotopologues might trace a
moderately high-velocity (~30-50 km/s) component of the flows around the
high-mass protostar Source I in the Orion BN/KL region.
  We also confirm the 7 mm detection of a complex oxygen-bearing species,
acetone (CH3COCH3), which has been recently observed towards the hot core at 3
mm, and we have found further indications of the presence of long cyanopolyynes
(HC5N and HC7N) in the quiescent cold gas of the extended ridge.


title:
Multiwavelength spectral and high time resolution observations of SWIFT
  J1753.5-0127: new activity?

abstract:
  We have conducted an extensive observational campaign of SWIFT J1753.5-0127
during June 2007 after its bright outburst episode in 2005. We have performed
multi-band optical photometry, optical spectroscopy, X-ray spectroscopy and
timing and ULTRACAM optical photometry simultaneously in three bands. Both the
optical spectrum and the X-ray spectrum, along with enhanced brightness in
broad-band photometry point to recent increased activity. We analyze the
different spectral regions, finding a smooth optical continuum with a
remarkable lack of lines and a very blue component modulated with a period of
3.2hr and a hard power-law X-ray spectrum. Both the X-ray and optical power
spectra are flat at low frequencies up to the 0.1 Hz (10 s) range, then
decreasing roughly as a power law consistent with flickering. Furthermore, the
optical data show quasi-periodic oscillations (QPOs) near 0.08 Hz (13 s).
Together with a dynamical and auto-correlation analysis of the light curves we
attempt to construct a complete physical picture of this intriguing system.


title: Electroweak Sphalerons with Spin and Charge

abstract:
  We show that, at finite weak mixing angle the sphaleron solution of
Weinberg-Salam theory can be endowed with angular momentum proportional to the
electric charge. Carrying baryon number 1/2 these sphalerons with spin and
charge may contribute to baryon number violating processes.


title:
Backward asymmetry measurements in the elastic pion-proton scattering at
  resonance energies

abstract:
  The asymmetry parameter P was measured for the elastic pion-proton scattering
in the very backward angular region of theta_cm ~ 150-170^o at several pion
beam energies in the invariant mass range containing most of the pion-proton
resonances.
  The general goal of the experimental program was to provide new data for
partial wave analyses in order to resolve their uncertainties in the baryon
resonance region to allow the unambiguous baryon spectrum reconstructions.
Until recently the parameter P was not measured in the examined domain that
might be explained by the extremely low cross section. At the same time the
predictions of various partial wave analyses are far from agreement in some
kinematic areas and specifically those areas were chosen for the measurements
where the disagreement is most pronouncing.
  The experiment was performed at the ITEP U-10 proton synchrotron, Moscow, by
the ITEP-PNPI collaboration in the latest 5 years.


title: B -> pi, B(s) -> K form factors and Vub determination

abstract:
  We present a QCD light-cone sum rule (LCSR) estimation of the B -> pi, B ->
K, and Bs -> K form factors calculating gluon radiative corrections at
next-to-leading order. The MS-bar b-quark mass is used, instead of the one-loop
pole mass employed in the previous analyses. For B -> K and Bs -> K form
factors the SU(3)-symmetry breaking corrections are included, both in the
hard-scattering kernels and in the distribution amplitudes (DAs). By combining
the predicted value for f^+_{Bpi}(0) with the product |Vub f^+_{Bpi}| extracted
from the B -> pi l nu measurement, we obtain the LCSR prediction for Vub CKM
matrix element.


title: Lee Wick Dark Energy

abstract:
  We consider the cosmological application of Lee-Wick theory where a field has
a higher derivative kinetic operators. The higher derivative term can be
eliminated by introducing a set of auxiliary fields. We investigate the
cosmological evolutions of these fields as a candidate of dark energy. This
model has the same structure as so called ``quintom' model except the form of
potentials and the sign of the slope of the potentials. This model can give the
stable late time phantom dominated scaling solution ($\omega_{\DE} < -1$) or
tracking attractors ($\omega_{\DE} = 0$) depending on the choice of the slopes
of the potential. In order to be a viable dark energy candidate, the present
energy density contrast of dark energy ($\Omega_{\DE}^{(0)}$) should be close
to an observed value (0.73) at the same time. However, a simple toy model of
the theory can not satisfy both $\omega_{\DE}^{(0)} \simeq -1$ and
$\Omega_{\DE}^{(0)} = 0.73$. If we include the self interaction term of Lee
Wick field, then we are able to produce the observed values of those
quantities. However, in this case we are not be able to have the stable
solutions and we need to suffer from the fine tuning of its mass.


title:
Analysis of a class of non linear subdivision schemes and associated
  multi-resolution transforms

abstract:
  This paper is devoted to the convergence and stability analysis of a class of
nonlinear subdivision schemes and associated multi-resolution transforms. These
schemes are defined as a perturbation of a linear subdivision scheme. Assuming
a contractivity property, stability and convergence are derived. These results
are then applied to various schemes such as uncentered interpolatory linear
scheme, WENO scheme [13], Power-P scheme [16] and a non linear scheme using
local spherical coordinates [18].


title: $p$-Adic multiresolution analyses

abstract:
  We study $p$-adic multiresolution analyses (MRAs). A complete
characterisation of test functions generating a MRA (scaling functions) is
given. We prove that only 1-periodic test functions may be taken as orthogonal
scaling functions and that all such scaling functions generate Haar MRA. We
also suggest a method of constructing sets of wavelet functions and prove that
any set of wavelet functions generates a $p$-adic wavelet frame.


title: Cox rings, semigroups and automorphisms of affine algebraic varieties

abstract:
  We study the Cox realization of an affine variety, i.e., a canonical
representation of a normal affine variety with finitely generated divisor class
group as a quotient of a factorially graded affine variety by an action of the
Neron-Severi quasitorus. The realization is described explicitly for the
quotient space of a linear action of a finite group. A universal property of
this realization is proved, and some results on the divisor theory of an
abstract semigroup emerging in this context are given. We show that each
automorphism of an affine variety can be lifted to an automorphism of the Cox
ring normalizing the grading. It follows that the automorphism group of a
non-degenerate affine toric variety of dimension $\geq 2$ has infinite
dimension. We obtain a wild automorphism of the three-dimensional quadratic
cone that rises to Anick's automorphism of the polynomial algebra in four
variables.


title:
Photometric/spectroscopic analyses and magnetic activity in young
  late-type stars

abstract:
  We present the work in progress of a study based on photometric and
spectroscopic observations of young Weak-line T Tauri and Post T Tauri stars
just attiving on the Zero Age Main Sequence. This study is part of a project
based on high-resolution spectra obtained with FOCES@CAHA (Spain) and SARG@TNG
(Spain) and contemporaneous photometry performed at Catania (Italy) and Ege
(Turkey) observatories. The main aim is to investigate the topology of magnetic
active regions at photospheric and chromospheric levels in young single stars.
Since our targets are slow rotators (vsini < 25 km/s), corresponding to
rotation periods larger than about 2 days, we are able to apply the
spectroscopic technique based on line-depth ratio for the measure of the
photospheric temperature modulation. These stars, possible members of Stellar
Kinematic Groups, display emission cores in the CaII H&K and IRT lines, as well
as a conspicuous filling-in of the Halpha core. Moreover, we detect absorption
of the HeI-D3 line, coming from the upper chromospheric layers, derive the
lithium abundance (age indicator), and measure the rotational and radial
velocities. We find a clear rotational modulation, due to photospheric spots,
both in the light and the temperature curves. The Halpha and the CaII-IRT
emissions display a fair variation correlated with the rotation. Finally, we
are developing a spot/plage model to reproduce the data and derive the spot
parameters (namely, filling factor and temperature) and to recover information
about the chromospheric inhomogeneities (flux contrast and filling factor).
This study is very important to explore the correlations between global stellar
parameters (e.g., surface gravity, effective temperature) and spot/plage
characteristics in stars with different activity level and evolutionary stage.


title: Inference for the limiting cluster size distribution of extreme values

abstract:
  Any limiting point process for the time normalized exceedances of high levels
by a stationary sequence is necessarily compound Poisson under appropriate long
range dependence conditions. Typically exceedances appear in clusters. The
underlying Poisson points represent the cluster positions and the
multiplicities correspond to the cluster sizes. In the present paper we
introduce estimators of the limiting cluster size probabilities, which are
constructed through a recursive algorithm. We derive estimators of the extremal
index which plays a key role in determining the intensity of cluster positions.
We study the asymptotic properties of the estimators and investigate their
finite sample behavior on simulated data.


title: Periodic Single-Pass Instruction Sequences

abstract:
  A program is a finite piece of data that produces a (possibly infinite)
sequence of primitive instructions. From scratch we develop a linear notation
for sequential, imperative programs, using a familiar class of primitive
instructions and so-called repeat instructions, a particular type of control
instructions. The resulting mathematical structure is a semigroup. We relate
this set of programs to program algebra (PGA) and show that a particular
subsemigroup is a carrier for PGA by providing axioms for single-pass
congruence, structural congruence, and thread extraction. This subsemigroup
characterizes periodic single-pass instruction sequences and provides a direct
basis for PGA's toolset.


title: The charm quark mass from non-relativistic sum rules

abstract:
  We present an analysis to determine the charm quark mass from
non-relativistic sum rules, using a combined approach taking into account
fixed-order and effective-theory calculations. Non-perturbative corrections as
well as higher-order perturbative corrections are under control. For the PS
mass we find m_{PS}(0.7 GeV) = 1.50\pm 0.04 GeV, which translates into a MS-bar
mass of m = 1.25\pm 0.04 GeV.


title: Superconductivity under high pressure in LaFeAsO

abstract:
  Electrical resistivity measurements under high pressures up to 29 GPa were
performed for oxypnictide compound LaFeAsO. We found a pressure-induced
superconductivity in LaFeAsO. The maximum value of Tc is 21 K at ~12 GPa. The
pressure dependence of the Tc is similar to those of LaFeAsO1-xFx series
reported previously.


title: A note on zeros of Eisenstein series for genus zero Fuchsian groups

abstract:
  Let $\Gamma \subseteq \text{SL}_2(\mathbb{R})$ be a genus zero Fuchsian group
of the first kind having $\infty$ as a cusp, and let $E_{2 k}^{\Gamma}$ be the
holomorphic Eisenstein series associated with $\Gamma$ for the $\infty$ cusp
that does not vanish at $\infty$ but vanishes at all the other cusps. In the
paper "On zeros of Eisenstein series for genus zero Fuchsian groups", under
assumptions on $\Gamma$, and on a certain fundamental domain $\mathcal{F}$, H.
Hahn proved that all but at most $c(\Gamma, \mathcal{F})$ (a constant) of the
zeros of $E_{2 k}^{\Gamma}$ lie on a certain subset of $\{z \in \mathfrak{H}
  : j_{\Gamma}(z) \in \mathbb{R}\}$.
  In this note, we consider a small generalization of Hahn's result on the
domain locating the zeros of $E_{2 k}^{\Gamma}$. We can prove most of the zeros
of $E_{2 k}^{\Gamma}$ in $\mathcal{F}$ lie on its lower arcs under the same
assumption.


title: Electroweak corrections to squark pair production at the LHC

abstract:
  Presented are the complete NLO electroweak contributions to the production of
diagonal squark--anti-squark pairs at the LHC. We discuss their effects for the
production of squarks of the first two generations, in different SUSY
scenarios.


title:
A strong uniform convergence rate of a kernel conditional quantile
  estimator under random left-truncation and dependent data

abstract:
  In this paper we study some asymptotic properties of the kernel conditional
quantile estimator with randomly left-truncated data which exhibit some kind of
dependence. We extend the result obtained by Lemdani, Ould-Sa\"id and Poulin
[16] in the iid case. The uniform strong convergence rate of the estimator
under strong mixing hypothesis is obtained.


title:
Proposed all-versus-nothing violation of local realism in the Kitaev
  spin-lattice model

abstract:
  We investigate the nonlocal property of the fractional statistics in Kitaev's
toric code model. To this end, we construct the Greenberger-Horne-Zeilinger
paradox which builds a direct conflict between the statistics and local
realism. It turns out that the fractional statistics in the model is purely a
quantum effect and independent of any classical theory.We also discuss a
feasible experimental scheme using anyonic interferometry to test this
contradiction.


title: (SUSY) Higgs Search at the LHC

abstract:
  The discovery of the Standard Model (SM) or supersymmetric (SUSY) Higgs
bosons belongs to the main endeavors of the Large Hadron Collider (LHC). In
this article the status of the signal and background calculations for Higgs
boson production at the LHC is reviewed.


title:
Exactly solvable effective mass D-dimensional Schrodinger equation for
  pseudoharmonic and modified Kratzer problems

abstract:
  We employ the point canonical transformation (PCT) to solve the D-dimensional
Schr\"{o}dinger equation with position-dependent effective mass (PDEM) function
for two molecular pseudoharmonic and modified Kratzer (Mie-type) potentials. In
mapping the transformed exactly solvable D-dimensional ($D\geq 2$)
Schr\"{o}dinger equation with constant mass into the effective mass equation by
employing a proper transformation, the exact bound state solutions including
the energy eigenvalues and corresponding wave functions are derived. The
well-known pseudoharmonic and modified Kratzer exact eigenstates of various
dimensionality is manifested.


title: Quasi-Lie schemes: theory and applications

abstract:
  A powerful method for solving non-linear first-order ordinary differential
equations, which is based on geometrical understanding of the corresponding
dynamics of the so called Lie systems, is developed. This method allows us not
only to solve some of these equations, but also gives a geometrical
explanations for some, already known, ad hoc methods of dealing with such
problems.


title: Towards a three dimensional solution for 3N bound states with 3NFs

abstract:
  After a brief discussion about the necessity of using the 3D approach, we
present the non PW formalism for 3N bound state with the inclusion of 3N force
(3NF). As an example the evaluation of 3NF matrix elements, which appear in the
obtained coupled three dimensional integral equations, for $2\pi$-exchange
Tucson-Melbourne 3NF show how would be this formalism efficient and less
cumbersome in comparison with the PW formalism.


title: A remark on double cosets

abstract:
  If a soluble group $G$ contains two finitely generated abelian subgroups
$A,B$ such that the number of double cosets $AgB$ is finite, then $G$ is shown
to be virtually polycyclic.


title:
Generalised linear mixed model analysis via sequential Monte Carlo
  sampling

abstract:
  We present a sequential Monte Carlo sampler algorithm for the Bayesian
analysis of generalised linear mixed models (GLMMs). These models support a
variety of interesting regression-type analyses, but performing inference is
often extremely difficult, even when using the Bayesian approach combined with
Markov chain Monte Carlo (MCMC). The Sequential Monte Carlo sampler (SMC) is a
new and general method for producing samples from posterior distributions. In
this article we demonstrate use of the SMC method for performing inference for
GLMMs. We demonstrate the effectiveness of the method on both simulated and
real data, and find that sequential Monte Carlo is a competitive alternative to
the available MCMC techniques.


title: Estimating the multivariate extremal index function

abstract:
  The multivariate extremal index function relates the asymptotic distribution
of the vector of pointwise maxima of a multivariate stationary sequence to that
of the independent sequence from the same stationary distribution. It also
measures the degree of clustering of extremes in the multivariate process. In
this paper, we construct nonparametric estimators of this function and prove
their asymptotic normality under long-range dependence and moment conditions.
The results are illustrated by means of a simulation study.


title:
Generating highly squeezed Hybrid Laguerre-Gauss modes in
  large-Fresnel-number Degenerate Optical Parametric Oscillators

abstract:
  We theoretically describe the quantum properties of a large Fresnel number
degenerate optical parametric oscillator with spherical mirrors that is pumped
by a Gaussian beam. The resonator is tuned so that the resonance frequency of a
given transverse mode family coincides with the down-converted frequency. After
demonstrating that only the lower orbital angular momentum (OAM) Laguerre-Gauss
modes are amplified above threshold, we focus on the quantum properties of the
rest of (classically empty) modes. We find that combinations of opposite OAM
(Hybrid Laguerre-Gauss modes) can exhibit arbitrary large quadrature squeezing
for the lower OAM non amplified modes.


title:
Worldline Casting of the Stochastic Vacuum Model and Non-Perturbative
  Properties of QCD: General Formalism and Applications

abstract:
  The Stochastic Vacuum Model for QCD, proposed by Dosch and Simonov, is fused
with a Worldline casting of the underlying theory, i.e. QCD. Important,
non-perturbative features of the model are studied. In particular,
contributions associated with the spin-field interaction are calculated and
both the validity of the loop equations and of the Bianchi identity are
explicitly demonstrated. As an application, a simulated meson-meson scattering
problem is studied in the Regge kinematical regime. The process is modeled in
terms of the "helicoidal" Wilson contour along the lines introduced by Janik
and Peschanski in a related study based on a AdS/CFT-type approach. Working
strictly in the framework of the Stochastic Vacuum Model and in a semiclassical
approximation scheme the Regge behavior for the Scattering amplitude is
demonstrated. Going beyond this approximation, the contribution resulting from
boundary fluctuation of the Wilson loop contour is also estimated.


title:
Breakdown of the impulse approximation and its consequences: the low-Q^2
  problem

abstract:
  Neutrino scattering data and the standard calculations of the cross section
show a discrepancy in the low-Q^2 (four-momentum transfer squared) region. The
calculations rely on the assumption, called the impulse approximation, that the
nucleus the neutrino scatters off can be described as a collection of
independent nucleons and therefore only one nucleon takes part in the
interaction. It is known from electron scattering that such picture is valid
only when transferred momentum |q|>400 MeV/c. For lower |q|'s, the nucleus is
probed with a lower spatial resolution and a few nucleons are involved in the
scattering, so the use of the impulse approximation is unjustified. It means
that the standard calculations of the cross sections are unreliable for |q|<400
MeV/c. I show that the contribution of low-momentum interactions to the
quasielastic neutrino cross section cannot be reduced below ~19% by any
selection of the beam energy in the few-GeV region. Moreover, low-Q^2 neutrino
events happen only when transferred momentum is low too. Hence the discrepancy
in the low-Q^2 region is caused by the inappropriate description of low-|q|
interactions in the models commonly used in Monte Carlo simulations.


title: The efficiency of the molecular motors

abstract:
  Molecular motors convert chemical energy into mechanical work while operating
in an environment dominated by Brownian motion. The aim of this paper is to
explore the flow of energy between the molecular motors and its surroundings,
in particular, its efficiency. Based on the Fokker-Planck equation with either
$N$ or infinite chemical states, we find that the energy efficiency of the
molecular motors, whether the Stokes efficiency or the usual thermodynamic
efficiency, is strictly bounded by 1, because of the dissipation of the energy
in both the overdamped surroundings and in the process of the chemical
reaction.


title:
CHSH type Bell inequalities involving a party with two or three local
  binary settings

abstract:
  We construct a simple algorithm to generate any CHSH type Bell inequality
involving a party with two local binary measurements from two CHSH type
inequalities without this party. The algorithm readily generalizes to
situations, where the additional observer uses three measurement settings.
There, each inequality involving the additional party is constructed from three
inequalities with this party excluded. With this generalization at hand, we
construct and analyze new symmetric inequalities for four observers and three
experimental settings per observer.


title: Huge anisotropic magneto-resistance in iridium atomic chains

abstract:
  We analyze in this article the magneto-resistance ratio of finite and
infinite iridium and platinum chains. Our calculations, that are based on a
combination of non equilibrium Green function techniques and density functional
theory, include a fully self-consistent treatment of non-collinear magnetism
and of the spin-orbit interaction. They indicate that, in addition to having an
extremely large magnetic anisotropy that may overcome the super-paramagnetic
limit, infinite and also realistic finite-length iridium chains show sizeable
anisotropic magnetoresistance ratios. We therefore propose iridium
nanostructures as promising candidates for nanospintronics logic devices.


title:
Non-Perturbative Regge Exchange in Meson-Meson Scattering: An Analysis
  Based on the Stochastic Vacuum Model

abstract:
  Employing the Worldline casting of the Dosch-Simonov Stochastic Vacuum
Model(SVM) for QCD, a simulated meson-meson scattering is studied in the Regge
kinematical regime. The process is modelled in terms of the "helicoidal" Wilson
contour first introduced by Janic and Peschanski in a related study based on an
AdS/CFT-type approach. Using lattice supported estimations for the behavior of
a two-point, field strength correlation function, as defined in the framework
of the SVM, the reggeon slope and intercept are calculated in a semiclassical
approximation. The resulting values are in good agreement with the accepted
phenomenological ones. Going beyond this approximation, the contribution
resulting from boundary fluctuations of the Wilson loop contour is also
estimated.


title: Electromagnetic Lorenz Fields

abstract:
  Gauge transformations are potential transformations that leave only specific
Maxwell fields invariant. To reveal more, I develop Lorenz field equations with
full Maxwell form for nongauge, sans gauge function, transformations yielding
mixed, superposed retarded and outgoing, potentials. The form invariant Lorenz
condition is then a charge conservation equivalent. This allows me to define
three transformation classes that screen for Lorenz relevance. The nongauge
Lorentz conditions add polarization fields which support emergent, light-like
rays that convey energy on charge conserving phase points. These localized rays
escape discovery in modern Maxwell fields where the polarizations are
suppressed by gauge transformations.


title:
Adaptive asymptotically efficient estimation in heteroscedastic
  nonparametric regression via model selection

abstract:
  The paper deals with asymptotic properties of the adaptive procedure proposed
in the author paper, 2007, for estimating a unknown nonparametric regression.
We prove that this procedure is asymptotically efficient for a quadratic risk,
i.e. the asymptotic quadratic risk for this procedure coincides with the
Pinsker constant which gives a sharp lower bound for the quadratic risk over
all possible estimators.


title: Analysis of a Population Model Structured by the Cells Molecular Content

abstract:
  We study the mathematical properties of a general model of cell division
structured with several internal variables. We begin with a simpler and
specific model with two variables, we solve the eigenvalue problem with strong
or weak assumptions, and deduce from it the long-time convergence. The main
difficulty comes from natural degeneracy of birth terms that we overcome with a
regularization technique. We then extend the results to the case with several
parameters and recall the link between this simplified model and the one
presented in \cite{CBBP1}; an application to the non-linear problem is also
given, leading to robust subpolynomial growth of the total population.


title: Monogamy of Bell's inequality violations in non-signaling theories

abstract:
  We derive monogamy relations (tradeoffs) between strengths of violations of
Bell's inequalities from the non-signaling condition. Our result applies to
general Bell inequalities with an arbitrary large number of partners, outcomes
and measurement settings. The method is simple, efficient and does not require
linear programming. The results are used to derive optimal fidelity for
asymmetric cloning in nonsignaling theories.


title:
A group with three real irreducible characters: answering a question of
  Moreto and Navarro

abstract:
  In this paper, we construct a group with three real irreducible characters
whose Sylow 2-subgroup is an iterated central extension of a Suzuki 2-group.
This answers a question raised by Moreto and Navarro who asked whether such a
group exists.


title: Circular Orbits in Einstein-Gauss-Bonnet Gravity

abstract:
  The stability under radial and vertical perturbations of circular orbits
associated to particles orbiting a spherically symmetric center of attraction
is study in the context of the n-dimensional: Newtonian theory of gravitation,
Einstein's general relativity, and Einstein-Gauss-Bonnet theory of gravitation.
The presence of a cosmological constant is also considered. We find that this
constant as well as the Gauss-Bonnet coupling constant are crucial to have
stability for $n>4$.


title: Prospects for Discovering Supersymmetry at the LHC

abstract:
  Supersymmetry is one of the best-motivated candidates for physics beyond the
Standard Model that might be discovered at the LHC. There are many reasons to
expect that it may appear at the TeV scale, in particular because it provides a
natural cold dark matter candidate. The apparent discrepancy between the
experimental measurement of g_mu - 2 and the Standard model value calculated
using low-energy e+ e- data favours relatively light sparticles accessible to
the LHC. A global likelihood analysis including this, other electroweak
precision observables and B-decay observables suggests that the LHC might be
able to discover supersymmetry with 1/fb or less of integrated luminosity. The
LHC should be able to discover supersymmetry via the classic missing-energy
signature, or in alternative phenomenological scenarios. The prospects for
discovering supersymmetry at the LHC look very good.


title:
Investigation of astrophysical phenomena in short time scales with "Pi
  of the Sky" apparatus

abstract:
  In this thesis the data analysis designed by author for the "Pi of the Sky"
experiment is presented. The data analysis consists of data reduction and
specific algorithms for identification of short time scale astrophysical
processes. The algorithms have been tested and their efficiency has been
determined and described. The "Pi of the Sky" prototype is collecting data
since June 2004 and algorithms could be intensively studied and improved during
over 700 nights. A few events of confirmed astrophysical origin and above 100
events in 10s time scale of unknown nature have been discovered. During the
data collection period 3 Gamma Ray Bursts (out of 231) occurred in the field of
view of the telescope, but no optical counterpart has been found. The upper
limits for brightness of the optical counterpart have been determined. The
continuous monitoring of the sky and own trigger for optical flashes allowed to
determine limits on the number of GRBs without corresponding gamma-ray
detection. This allowed determining limits on the ratio of emission collimation
in optical and gamma bands, which is R >= 4.4. The perspectives of the full "Pi
of the Sky" system has been studied and number of positive detections has been
estimated on the level of ~ 2.5 events per year.


title:
Multiple flaring activity in the supergiant fast X-ray transient IGR
  J08408-4503 observed with Swift

abstract:
  IGR J08408-4503 is a supergiant fast X-ray transient discovered in 2006 with
a confirmed association with a O8.5Ib(f) supergiant star, HD 74194. We report
on the analysis of two outbursts caught by Swift/BAT on 2006 October 4 and 2008
July 5, and followed up at softer energies with Swift/XRT. The 2008 XRT light
curve shows a multiple-peaked structure with an initial bright flare that
reached a flux of ~1E-9 erg/cm2/s (2-10 keV), followed by two equally bright
flares within 75 ks. The spectral characteristics of the flares differ
dramatically, with most of the difference, as derived via time-resolved
spectroscopy, being due to absorbing column variations. We observe a gradual
decrease of the NH, derived with a fit using absorbed power law model, as time
passes. We interpret these NH variations as due to an ionization effect
produced by the first flare, resulting in a significant decrease in the
measured column density towards the source. The durations of the flares, as
well as the times of the outbursts suggest that the orbital period is ~35 days,
if the flaring activity is interpreted within the framework of the Sidoli et al
2007 model with the outbursts triggered by the neutron star passage inside an
equatorial wind inclined with respect to the orbital plane.


title:
Domain wall of the totally asymmetric exclusion process without particle
  number conservation

abstract:
  In this research, the totally asymmetric exclusion process without particle
number conservation is discussed. Based on the mean field approximation and the
Rankine-Hugoniot condition, the necessary and sufficient conditions of the
existence of the domain wall have been obtained. Moreover, the properties of
the domain wall, including the location and height, have been studied
theoretically. All the theoretical results are demonstrated by the computer
simulations.


title:
A network approach for the scientific collaboration in the European
  Framework Programs

abstract:
  We construct the networks of collaboration between partners for projects
carried out with the support of European Commission Framework Programs FP5 and
FP6. We analyze in detail these networks, not only in terms of total number of
projects, but also for the different tools employed, the different geographical
partitions, and the different thematic areas. For all cases we find a scale
free behavior, as expected for such social networks, and also reported in the
literature. In comparing FP5 to FP6, we show that despite a decrease in the
number of signed contracts, and the total number of unique partners, there is
an increase in the average number of collaborative partners per institution.
Furthermore, we establish a measure for the central role (hub) for each
country, by using the Minimum Spanning Tree (MST), which we construct in detail
for each thematic area (e.g. Informatics, Nanoscience, Life Sciences, etc.).
The importance of these network hubs is highlighted, as this information can be
used by policy planners in designing future research plans regarding the
distribution of available funds.


title: Orthogonal Evolution and Anticipation

abstract:
  Quantum states evolving at equidistant steps into a set of mutually
orthogonal states of finite or infinite cardinality p exhibit an interesting
physical effect. The analysis of the amplitudes of the state at half the step
time with the elements of this set (the anticipation amplitudes) shows, that
for randomly chosen states measurements of the state at half-step time reveal
information about the states at full step time, anticipating future states and
reflecting past states with significant probability. For fixed N and p to
infinity, the probability to measure a state which is N steps apart in future
or past exceeds a constant lower bound. We characterize the spectrum, establish
an analog to Plack's relation, define a random sampling scheme, analyze the
resulting distribution of the anticipation probabilities and point out
applications.


title: Dynamics of continuous-time quantum walks in restricted geometries

abstract:
  We study quantum transport on finite discrete structures and we model the
process by means of continuous-time quantum walks. A direct and effective
comparison between quantum and classical walks can be attained based on the
average displacement of the walker as a function of time. Indeed, a fast growth
of the average displacement can be advantageously exploited to build up
efficient search algorithms. By means of analytical and numerical
investigations, we show that the finiteness and the inhomogeneity of the
substrate jointly weaken the quantum walk performance. We further highlight the
interplay between the quantum-walk dynamics and the underlying topology by
studying the temporal evolution of the transfer probability distribution and
the lower bound of long time averages.


title:
Structure of hybrid polymer by numerical simulation: example of
  $(Si(CH_3)_2)_n(OSiO)_p(OH)_q$

abstract:
  The structure depends on the mechanism of hydrolyse and polycondensation in
the case sol-gel process used to obtain hybrid polymers containing uniquely
covalent bonds. We computed by a tight binding calculation taking into account
hybridization, the total electronic energy of different structures (amorphous,
fractal and linear) of $(Si-(CH_3)_2)_n-(OSiO)_p(OH)_q$. We found that the
total electronic energy of the amorphous structure was the smallest as a
function of the number of atoms contained by the structure. As the total
electronic energy is linked to the toughness of the structure, we may say that
the structure of such hybrid polymer has the highest toughness for the
amorphous structure.


title: On-the-fly Macros

abstract:
  We present a domain-independent algorithm that computes macros in a novel
way. Our algorithm computes macros "on-the-fly" for a given set of states and
does not require previously learned or inferred information, nor prior domain
knowledge. The algorithm is used to define new domain-independent tractable
classes of classical planning that are proved to include \emph{Blocksworld-arm}
and \emph{Towers of Hanoi}.


title: Interference Alignment for Secrecy

abstract:
  This paper studies the frequency/time selective $K$-user Gaussian
interference channel with secrecy constraints. Two distinct models, namely the
interference channel with confidential messages and the one with an external
eavesdropper, are analyzed. The key difference between the two models is the
lack of channel state information (CSI) about the external eavesdropper. Using
interference alignment along with secrecy pre-coding, it is shown that each
user can achieve non-zero secure Degrees of Freedom (DoF) for both cases. More
precisely, the proposed coding scheme achieves $\frac{K-2}{2K-2}$ secure DoF
{\em with probability one} per user in the confidential messages model. For the
external eavesdropper scenario, on the other hand, it is shown that each user
can achieve $\frac{K-2}{2K}$ secure DoF {\em in the ergodic setting}.
Remarkably, these results establish the {\em positive impact} of interference
on the secrecy capacity region of wireless networks.


title: Knot Based Large Scale Structure Code (complete paper)

abstract:
  In the Dimension Embedded in Unified Symmetry (Adrian Sabin Popescu, D.E.U.S.
(Dimension Embedded in Unified Symmetry), p. 221-247, Ed. Cartea Universitara,
Bucuresti, ISBN 978-973-731-519-9 (arXiv:0704.2670) (2007)) book we made a
qualitative description of the way in which we can construct the Large Scale
Structure of the Universe from the knot-particle equivalence. Even that we are
limited by the lack of computational power implemented on a nonlinear
computational architecture needed to conduct this study to its finish, we are
still able to give the algorithm to be used in a future simulation, on a, let
say, quantum computer.


title: Self-similarity degree of deformed statistical ensembles

abstract:
  We consider self-similar statistical ensembles with the phase space whose
volume is invariant under the deformation that squeezes (expands) the
coordinate and expands (squeezes) the momentum. Related probability
distribution function is shown to possess a discrete symmetry with respect to
manifold action of the Jackson derivative to be a homogeneous function with a
self-similarity degree $q$ fixed by the condition of invariance under
$(n+1)$-fold action of the dilatation operator related. In slightly deformed
phase space, we find the homogeneous function is defined with the linear
dependence at $n=0$, whereas the self-similarity degree equals the gold mean at
$n=1$, and $q\to n$ in the limit $n\to\infty$. Dilatation of the homogeneous
function is shown to decrease the self-similarity degree $q$ at $n>0$.