title:
Optical Absorption Spectra of Ag11 Isomers by First-Principles
  Theoretical Spectroscopy with Time-dependent Density Functional Theory

abstract:
  The optical absorption spectrum of the three most stable isomers of the Ag11
system was calculated using the time-dependent density functional theory, with
the generalized gradient approximation for the exchange and correlation
potential, and a relativistic pseudopotential parametrization for the modelling
of the ion-electron interaction. The computational scheme is based on a real
space code, where the photoabsorption spectrum is calculated by using the
formalism developed by Casida. The significantly different spectra of the three
isomers permit the identification of the ground-state configuration
predominantly present in the laboratory beams in base to a comparison between
the calculated photoabsorption spectrum of the most stable configuration of
Ag11 and the measured spectra of medium-size silver clusters trapped in noble
gas Ar and Ne matrices at different temperatures. This assignment is confirmed
by the fact that this isomer has the lowest calculated energy.


title:
Transport signature of pseudo-Jahn-Teller dynamics in a single-molecule
  transistor

abstract:
  We calculate the electronic transport through a molecular dimer, in which an
excess electron is delocalized over equivalent monomers, which can be locally
distorted. In this system the Born-Oppenheimer approximation breaks down
resulting in quantum entanglement of the mechanical and electronic motion. We
show that pseudo Jahn-Teller (pJT) dynamics of the molecule gives rise to
conductance peaks that indicate this violation. Their magnitude, sign and
position sharply depend on the electro-mechanical properties of the molecule,
which can be varied in recently developed three-terminal junctions with
mechanical control. The predicted effect depends crucially on the degree of
intramolecular delocalization of the excess electron, a parameter which is also
of fundamental importance in physical chemistry.


title: Consistent estimation of the architecture of multilayer perceptrons

abstract:
  We consider regression models involving multilayer perceptrons (MLP) with one
hidden layer and a Gaussian noise. The estimation of the parameters of the MLP
can be done by maximizing the likelihood of the model. In this framework, it is
difficult to determine the true number of hidden units using an information
criterion, like the Bayesian information criteria (BIC), because the
information matrix of Fisher is not invertible if the number of hidden units is
overestimated. Indeed, the classical theoretical justification of information
criteria relies entirely on the invertibility of this matrix. However, using
recent methodology introduced to deal with models with a loss of
identifiability, we prove that suitable information criterion leads to
consistent estimation of the true number of hidden units.


title: An Algebraic Characterization of Security of Cryptographic Protocols

abstract:
  Several of the basic cryptographic constructs have associated algebraic
structures. Formal models proposed by Dolev and Yao to study the
(unconditional) security of public key protocols form a group. The security of
some types of protocols can be neatly formulated in this algebraic setting. We
investigate classes of two-party protocols. We then consider extension of the
formal algebraic framework to private-key protocols. We also discuss concrete
realization of the formal models. In this case, we propose a definition in
terms of pseudo-free groups.


title:
Investigation of the seismicity after the initiation of a Seismic
  Electric Signal activity until the main shock

abstract:
  The behavior of seismicity in the area candidate to suffer a main shock is
investigated after the observation of the Seismic Electric Signal activity
until the impending mainshock. This makes use of the concept of natural time
$\chi$ and reveals that the probability density function of the variance
$\kappa_1(=< \chi^2 > -< \chi > ^2)$ exhibits distinct features before the
occurrence of the mainshock. Examples are presented, which refer to magnitude
class 6.0 earthquakes that occurred in Greece during the first two months in
2008.


title: Near Horizon Analysis of Extremal AdS5 Black Holes

abstract:
  We study the near horizon geometry of extremal black holes in five
dimensional gauged supergravity using Sen's entropy function formalism. Special
attention is paid to the large black hole limit where the near horizon solution
exhibits a universal dependence on the rotation. The physical properties of the
large black hole solution are shown to agree with predictions from fluid
mechanical description of the dual conformal field theory.


title:
A coagulation-fragmentation model for the turbulent growth and
  destruction of preplanetesimals

abstract:
  To treat the problem of growing protoplanetary disc solids across the meter
barrier, we consider a very simplified two-component coagulation-fragmentation
model that consists of macroscopic boulders and smaller dust grains, the latter
being the result of catastrophic collisions between the boulders. Boulders in
turn increase their radii by sweeping up the dust fragments. An analytical
solution to the dynamical equations predicts that growth by
coagulation-fragmentation can be efficient and allow agglomeration of
10-meter-sized objects within the time-scale of the radial drift. These results
are supported by computer simulations of the motion of boulders and fragments
in 3-D time-dependent magnetorotational turbulence. Allowing however the
fragments to diffuse freely out of the sedimentary layer of boulders reduces
the density of both boulders and fragments in the mid-plane, and thus also the
growth of the boulder radius, drastically. The reason is that the turbulent
diffusion time-scale is so much shorter than the collisional time-scale that
dust fragments leak out of the mid-plane layer before they can be swept up by
the boulders there. Our conclusion that coagulation-fragmentation is not an
efficient way to grow across the meter barrier in fully turbulent
protoplanetary discs confirms recent results by Brauer, Dullemond, & Henning
who solved the coagulation equation in a parameterised turbulence model with
collisional fragmentation, cratering, radial drift, and a range of particle
sizes. We find that a relatively small population of boulders in a sedimentary
mid-plane layer can populate the entire vertical extent of the disc with small
grains and that these grains are not first generation dust, but have been
through several agglomeration-destruction cycles during the simulations.


title: Searching for gravitational waves from Cassiopeia A with LIGO

abstract:
  We describe a search underway for periodic gravitational waves from the
central compact object in the supernova remnant Cassiopeia A. The object is the
youngest likely neutron star in the Galaxy. Its position is well known, but the
object does not pulse in any electromagnetic radiation band and thus presents a
challenge in searching the parameter space of frequency and frequency
derivatives. We estimate that a fully coherent search can, with a reasonable
amount of time on a computing cluster, achieve a sensitivity at which it is
theoretically possible (though not likely) to observe a signal even with the
initial LIGO noise spectrum. Cassiopeia A is only the second object after the
Crab pulsar for which this is true. The search method described here can also
obtain interesting results for similar objects with current LIGO sensitivity.


title: Dimensional Regularization and Dimensional Reduction in the Light Cone

abstract:
  We calculate all the 2 to 2 scattering process in Yang-Mills theory in the
Light Cone gauge, with the dimensional regulator as the UV regulator. The IR is
regulated with a cutoff in $q^+$. It supplements our earlier work, where a
Lorentz non-covariant regulator was used and the final results bear some
problems in gauge fixing. Supersymmetry relations among various amplitudes are
checked using the light cone superfields.


title:
The achromatic chessboard, a new concept of phase shifter for Nulling
  Interferometry - I. theory

abstract:
  Direct detection of a planet around a star in the mid-IR, requires a nulling
interferometer featuring an achromatic phase shift of pi on broad range. A new
concept for designing such an achromatic phase shifter is presented here. The
major interest of this solution is that it allows a simple design, with
essentially one device per beam. The heart of the system consists in two
cellular mirrors where each cell has a thickness introducing for the central
wavelength, a phase shift of (2k+1)pi or of 2k pi on the fraction of the wave
it reflects. Each mirror is put in one of the collimated beams of the
interferometer. Because of the odd/even distribution, when recombining the two
beams, a destructive interference is produced on axis for the central
wavelength . If the distribution of cells thickness follows a rather simple
law, based on the Pascal's triangle, then the nulling is also efficient for a
wavelength not too far from the central wavelength. For instance, with two
mirrors of 64x64 cells, one reaches a nulling of 1.e-6 on more than one
complete octave. This could satisfy the specifications of space mission as
Darwin. We also show the way to distribute the cells in the plane of the pupil
for the optimum isolation of the planet image from the residual. We present the
nulling performances of those various configurations.


title: Gravitating Sphaleron-Antisphaleron Systems

abstract:
  We present new classical solutions of Einstein-Yang-Mills-Higgs theory,
representing gravitating sphaleron-antisphaleron pair, chain and vortex ring
solutions. In these static axially symmetric solutions, the Higgs field
vanishes on isolated points on the symmetry axis, or on rings centered around
the symmetry axis. We compare these solutions to gravitating
monopole-antimonopole systems, associating monopole-antimonopole pairs with
sphalerons.


title:
Density hardening plasticity and mechanical aging of silica glass under
  pressure: A Raman spectroscopic study

abstract:
  In addition of a flow, plastic deformation of structural glasses (in
particular amorphous silica) is characterized by a permanent densification.
Raman spectroscopic estimators are shown to give a full account of the plastic
behavior of silica under pressure. While the permanent densification of silica
has been widely discussed in terms of amorphous-amorphous transition, from a
plasticity point of view, the evolution of the residual densification with the
maximum pressure of a pressure cycle can be discussed as a density hardening
phenomenon. In the framework of such a mechanical aging effect, we propose that
the glass structure could be labelled by the maximum pressure experienced by
the glass and that the saturation of densification could be associated with the
densest packing of tetrahedra only linked by their vertices.


title:
Analysis of the exciton-exciton interaction in semiconductor quantum
  wells

abstract:
  The exciton-exciton interaction is investigated for quasi-two-dimensional
quantum structures. A bosonization scheme is applied including the full spin
structure. For generating the effective interaction potentials, the
Hartree-Fock and Heitler-London approaches are improved by a full two-exciton
calculation which includes the van der Waals effect. With these potentials the
biexciton formation in bilayer systems is investigated. For coupled quantum
wells the two-body scattering matrix is calculated and employed to give a
modified relation between exciton density and blue shift. Such a relation is of
central importance for gauging exciton densities in experiments which pave the
way toward Bose-Einstein condensation of excitons.


title:
Uniqueness of the Fock representation of the Gowdy $S^1\times S^2$ and
  $S^3$ models

abstract:
  After a suitable gauge fixing, the local gravitational degrees of freedom of
the Gowdy $S^1\times S^2$ and $S^3$ cosmologies are encoded in an axisymmetric
field on the sphere $S^2$. Recently, it has been shown that a standard field
parametrization of these reduced models admits no Fock quantization with a
unitary dynamics. This lack of unitarity is surpassed by a convenient
redefinition of the field and the choice of an adequate complex structure. The
result is a Fock quantization where both the dynamics and the SO(3)-symmetries
of the field equations are unitarily implemented. The present work proves that
this Fock representation is in fact unique inasmuch as, up to equivalence,
there exists no other possible choice of SO(3)-invariant complex structure
leading to a unitary implementation of the time evolution.


title:
Synchronized and desynchronized phases of coupled non-equilibrium
  exciton-polariton condensates

abstract:
  We theoretically analyze the synchronized and desynchronized phases of
coupled non-equilibrium polariton condensates within mean field theory. An
analytical condition for the existence of a synchronized phase is derived for
two coupled wells. The case of many wells in a 2D disordered geometry is
studied numerically. The relation to recent experiments on polariton
condensation in CdTe microcavities is discussed.


title: A GOES imager-derived microburst product

abstract:
  A new multispectral Geostationary Operational Environmental Satellite (GOES)
imager product has been developed to assess downburst potential over the
western United States employing brightness temperature differences (BTD)
between band 3 (upper level water vapor), band 4 (longwave infrared window),
and split window band 5. Band 3 is intended to indicate mid to upper-level
moisture content and advection while band 5 indicates low-level moisture
content. Large BTDs between bands 3 and 5 imply a large relative humidity
gradient between the mid-troposphere and the surface, a condition favorable for
strong convective downdraft generation due to evaporational cooling of
precipitation in the deep sub-cloud layer. In addition, small BTDs between
bands 4 and 5 indicate a relatively dry surface layer with solar heating in
progress. This paper will outline the development of the GOES-West imager
microburst product and present case studies that feature example images,
outline potential operational use and assess performance of the algorithm.


title:
Constraint-preserving boundary treatment for a harmonic formulation of
  the Einstein equations

abstract:
  We present a set of well-posed constraint-preserving boundary conditions for
a first-order in time, second-order in space, harmonic formulation of the
Einstein equations. The boundary conditions are tested using robust stability,
linear and nonlinear waves, and are found to be both less reflective and
constraint preserving than standard Sommerfeld-type boundary conditions.


title:
Ultra high-Q photonic crystal nanocavity design: The effect of a
  low-epsilon slab material

abstract:
  We analyze the influence of the dielectric constant of the slab on the
quality factor (Q) in slab photonic crystal cavities with a minimized vertical
losses model. The higher value of Q in high-epsilon cavity is attributed to the
lower mode frequency. The Q ratio in a high-epsilon (silicon) vs. low-epsilon
(diamond) slab is examined as a function of mode volume (Vm). The mode volume
compensation technique is discussed. Finally, diamond cavity design is
addressed. The analytical results are compared to 3D FDTD calculations. In a
double heterostructure design, a Q=2.6*10^5 is obtained. The highest Q=1.3*10^6
with Vm=1.77*(lambda/n)^3 in a local width modulation design is derived.


title: Generalized manifolds in products of curves

abstract:
  The intent of this article is to study some special $n$-dimensional continua
lying in products of $n$ curves. (The paper is an improved version of a portion
of \cite{K-K-S}.) We show that if $X$ is a locally connected, so-called, quasi
$n$-manifold lying in a product of $n$ curves then rank of $H^1(X)\ge n$.
Moreover, if $\rank H^1(X)<2n$ then $X$ can be represented as a product of an
$m$-torus and a quasi $(n-m)$-manifold, where $m\ge2n-\rank H^1(X)$. It follows
that certain 2-dimensional contractible polyhedra are not embeddable in
products of two curves. On the other hand, we show that any collapsible
2-dimensional polyhedron can be embedded in a product of two trees. We answer a
question of R. Cauty proving that closed surfaces embeddable in products of two
curves can be also embedded in products of two graphs. On the other hand, we
construct an example of a 2-dimensional polyhedron which can be embedded in a
product of two curves though it is not embeddable in any product of two
graphes. This solves in the negative another problem of Cauty.


title:
Lithographically and electrically controlled strain effects on
  anisotropic magnetoresistance in (Ga,Mn)As

abstract:
  It has been demonstrated that magnetocrystalline anisotropies in (Ga,Mn)As
are sensitive to lattice strains as small as 10^-4 and that strain can be
controlled by lattice parameter engineering during growth, through post growth
lithography, and electrically by bonding the (Ga,Mn)As sample to a
piezoelectric transducer. In this work we show that analogous effects are
observed in crystalline components of the anisotropic magnetoresistance (AMR).
Lithographically or electrically induced strain variations can produce
crystalline AMR components which are larger than the crystalline AMR and a
significant fraction of the total AMR of the unprocessed (Ga,Mn)As material. In
these experiments we also observe new higher order terms in the
phenomenological AMR expressions and find that strain variation effects can
play important role in the micromagnetic and magnetotransport characteristics
of (Ga,Mn)As lateral nanoconstrictions.


title:
Separation of anomalous and synchrotron emissions using WMAP
  polarization data

abstract:
  The main goals of this study is to use the information from both WMAP
intensity and polarization data to do a separation of the Galactic components,
with a focus on the synchrotron and anomalous emissions. Our analysis is made
at 23 GHz where the signal-to-noise ratio is the highest and the estimate of
the CMB map is less critical. Our estimate of the synchrotron intensity is
based on an extrapolation of the Haslam 408 MHz data with a spatially varying
spectral index constrained by the WMAP 23 GHz polarization data and a
bi-symmetrical spiral model of the galactic magnetic field with a turbulent
part following a -5/3 power law spectrum. The 23 GHz polarization data are
found to be compatible with a magnetic field with a pitch angle p=-8.5 degrees
and an amplitude of the turbulent part of the magnetic field 0.57 times the
local value of the field, in agreement with what is found using rotation
measures of pulsars and polarized extinction by dust. The synchrotron spectral
index between 408 MHz and 23 GHz obtained from polarization data and our model
of the magnetic field has a mean value of Beta=-3.00 with a limited spatial
variation with a standard deviation of 0.06. When thermal dust, free-free and
synchrotron are removed from the WMAP intensity data, the residual anomalous
emission is highly correlated with thermal dust emission with a spectrum in
agreement with spinning dust models. Considering a classical model of the large
scale Galactic magnetic field, we show that the polarization data of WMAP are
in favor of a soft synchrotron intensity highly correlated with the 408 MHz
data. Furthermore the combination of the WMAP polarization and intensity data
brings strong evidence for the presence of unpolarized spinning dust emission
in the 20-60 GHz range.


title:
The gravitomagnetic field of a sphere, Gravity Probe B and the LAGEOS
  satellites

abstract:
  The gravitomagnetic field generated by a rotating sphere is usually
calculated from the ideal dipole model. However, for a sphere with a
homogeneous mass density, this model is not generally valid. Trying to obtain a
more accurate value of the gravitomagnetic field inside and outside the sphere,
series expansions for this field are presented in this paper. The calculated
polar gravitomagnetic field of the sphere and that from the ideal dipole model
appear to coincide, but the field in the vicinity of the sphere may deviate.
The deduced field within the sphere strongly deviates from the ideal dipole
result. As an illustration, the gravitomagnetic precession rate (or
frame-dragging effect) of a gyroscope moving in the gravitomagnetic field from
a large rotating sphere is calculated. For the Gravity Probe B experiment the
result may coincide with the prediction from the ideal dipole model and in fair
agreement with observations. In addition, the obtained Lense-Thirring
precession rate for the LAGEOS satellites probably coincides with the standard
prediction. For both experiments alternative predictions are calculated, when
the gravitomagnetic field and the magnetic field from moving charge are
equivalent. Theoretical and observational indications for such an equivalence
are summarized. The obtained series expansions for the gravitomagnetic field of
a sphere can also be applied to the calculation of the magnetic field,
generated by a rotating sphere with a homogeneous charge density. Results for
this case are also discussed.


title: Bosonic reaction-diffusion processes on scale-free networks

abstract:
  Reaction-diffusion processes can be adopted to model a large number of
dynamics on complex networks, such as transport processes or epidemic
outbreaks. In most cases, however, they have been studied from a fermionic
perspective, in which each vertex can be occupied by at most one particle.
While still useful, this approach suffers from some drawbacks, the most
important probably being the difficulty to implement reactions involving more
than two particles simultaneously. Here we introduce a general framework for
the study of bosonic reaction-diffusion processes on complex networks, in which
there is no restriction on the number of interacting particles that a vertex
can host. We describe these processes theoretically by means of continuous time
heterogeneous mean-field theory and divide them into two main classes: steady
state and monotonously decaying processes. We analyze specific examples of both
behaviors within the class of one-species process, comparing the results
(whenever possible) with the corresponding fermionic counterparts. We find that
the time evolution and critical properties of the particle density are
independent of the fermionic or bosonic nature of the process, while
differences exist in the functional form of the density of occupied vertices in
a given degree class k. We implement a continuous time Monte Carlo algorithm,
well suited for general bosonic simulations, which allow us to confirm the
analytical predictions formulated within mean-field theory. Our results, both
at the theoretical and numerical level, can be easily generalized to tackle
more complex, multi-species, reaction-diffusion processes, and open a promising
path for a general study and classification of this kind of dynamical systems
on complex networks.


title:
Transverse momentum spectra of hadrons produced in central heavy-ion
  collisions

abstract:
  In-medium effects of transverse-mass distributions of quarks and gluons are
considered assuming a possible local equilibrium for colorless quark objects
like mesons and baryons created in central A+A collisions. It is shown that the
average square of the transverse momentum for these partons grows and then
saturates when the initial energy increases. Within the quark-gluon string
model it leads to the energy dependence of hadron transverse mass spectra which
is similar to that observed in heavy ion collisions. Comparison with other
scenarios is given.


title:
Bose-Einstein Condensation in the Relativistic Pion Gas: Thermodynamic
  Limit and Finite Size Effects

abstract:
  We consider the Bose-Einstein condensation (BEC) in a relativistic pion gas.
The thermodynamic limit when the system volume $V$ goes to infinity as well as
the role of finite size effects are studied. At $V\to \infty$ the scaled
variance for particle number fluctuations, $\omega=< \Delta N^2>/< N>$,
converges to finite values in the normal phase above the BEC temperature,
$T>T_C$. It diverges as $\omega \propto V^{1/3}$ at the BEC line $T=T_C$, and
$\omega \propto V$ at $T<T_C$ in a phase with the BE condensate. Possible
experimental signals of the pion BEC in finite systems created in high energy
proton-proton collisions are discussed.


title: New Massive Binaries in the Cygnus OB2 Association

abstract:
  As part of an ongoing study to determine the distribution of orbital
parameters for massive binaries in the Cygnus OB2 Association, we present the
orbital solutions for two new single-lined spectroscopic binaries, MT059 (O8V)
& MT258 (O8V), and one double-lined eclipsing binary (Schulte 3). We also
constrain the orbital elements of three additional double-lined systems (MT252,
MT720, MT771). Periods for all systems range from 1.5-19 days and
eccentricities range from 0-0.11. The six new OB binary systems bring the total
number of multiple systems within the core region of Cyg OB2 to 11. The current
sample does not show evidence for a ``twin-heavy'' binary distribution.


title: The computational difficulty of finding MPS ground states

abstract:
  We determine the computational difficulty of finding ground states of
one-dimensional (1D) Hamiltonians which are known to be Matrix Product States
(MPS). To this end, we construct a class of 1D frustration free Hamiltonians
with unique MPS ground states and a polynomial gap above, for which finding the
ground state is at least as hard as factoring. By lifting the requirement of a
unique ground state, we obtain a class for which finding the ground state
solves an NP-complete problem. Therefore, for these Hamiltonians it is not even
possible to certify that the ground state has been found. Our results thus
imply that in order to prove convergence of variational methods over MPS, as
the Density Matrix Renormalization Group, one has to put more requirements than
just MPS ground states and a polynomial spectral gap.


title: Beta-beams

abstract:
  Beta-beams is a new concept for the production of intense and pure neutrino
beams. It is at the basis of a proposed neutrino facility, whose main goal is
to explore the possible existence of CP violation in the lepton sector. Here we
briefly review the original scenario and the low energy beta-beam. This option
would offer a unique opportunity to perform neutrino interaction studies of
interest for particle physics, astrophysics and nuclear physics. Other proposed
scenarios for the search of CP violation are mentioned.


title:
Probing the Ionization Structure of the Narrow Line Region in the
  Seyfert 1 Galaxy NGC 4151

abstract:
  We present a study of the distribution of [O III] $\lambda$5007 and [O II]
$\lambda$3727 emission in the Narrow Line Region (NLR) of the Seyfert 1 galaxy
NGC 4151. While the NLR of NGC 4151 exhibits an overall structure consistent
with the unified model of Seyfert galaxies, narrow-band [O III] and [O II]
images obtained with the Wide Field and Planetary Camera 2 aboard the Hubble
Space Telescope reveal significant emission from outside the the emission-line
bi-cone. The [O III]/[O II] ratios are lower in these regions, consistent with
a weaker ionizing flux. We performed a photoionization modeling analysis of the
emission-line gas within a series of annuli, centered on the the central
continuum source, with inner radii from 13 to 90 pc. The gas is ionized by
radiation that has been attenuated by a relatively highly-ionized absorber
(HABS), which completely covers the central source, and a lower-ionization
absorber (LABS), which has a covering factor ranging from 0 to 1. We found that
the [O III]/[O II] ratios are well fit by assuming that, within each segment of
an annulus, some fraction of the NLR gas is completely within the shadow of
LABS, while the rest is irradiated by the continuum filtered only by HABS. This
suggests that the structure of the NLR is due to filtering of the ionizing
radiation by ionized gas, consistent with disk-wind models. One possible
scenario is that the low-ionization absorbers are dense knots of gas swept up
by a wind.


title: Thermodynamical Signatures of an Excitonic Insulator

abstract:
  In the 1960s speculations arose if a ground state exists in solid state
materials with an electron and a hole bound to a pair with their spins added to
integer values, i.e. excitons. Here we show that electrons and holes in
TmSe0.45Te0.55 do form excitons as the thermodynamical ground state. The
formation of a large number of excitons in an indirect gap semiconductor
requires momentum conservation by means of phonons and, hence, implies a
significant change of the heat capacity of the lattice, as found
experimentally. The thermodynamically derived phase diagram sustains a bosonic
ground state in condensed matter.


title: PVM-Distributed Implementation of the Radiance Code

abstract:
  The Parallel Virtual Machine (PVM) tool has been used for a distributed
implementation of Greg Ward's Radiance code. In order to generate exactly the
same primary rays with both the sequential and the parallel codes, the quincunx
sampling technique used in Radiance for the reduction of the number of primary
rays by interpolation, must be left untouched in the parallel implementation.
The octree of local ambient values used in Radiance for the indirect
illumination has been shared among all the processors. Both static and dynamic
image partitioning techniques which replicate the octree of the complete scene
in all the processors and have load-balancing, have been developed for one
frame rendering. Speedups larger than 7.5 have been achieved in a network of 8
workstations. For animation sequences, a new dynamic partitioning distribution
technique with superlinear speedups has also been developed.


title: A change of variable formula with It\^{o} correction term

abstract:
  We consider the solution $u(x,t)$ to a stochastic heat equation. For fixed
$x$, the process $F(t)=u(x,t)$ has a nontrivial quartic variation. It follows
that $F$ is not a semimartingale, so a stochastic integral with respect to $F$
cannot be defined in the classical It\^{o} sense. We show that for sufficiently
differentiable functions $g(x,t)$, a stochastic integral $\int
g(F(t),t)\,dF(t)$ exists as a limit of discrete, midpoint-style Riemann sums,
where the limit is taken in distribution in the Skorokhod space of cadlag
functions. Moreover, we show that this integral satisfies a change of variable
formula with a correction term that is an ordinary It\^{o} integral with
respect to a Brownian motion that is independent of $F$.


title:
Broadband X-ray Spectra of GX 339-4 and the Geometry of Accreting Black
  Holes in the Hard State

abstract:
  A major question in the study of black hole binaries involves our
understanding of the accretion geometry when the sources are in the hard state.
In this state, the X-ray energy spectrum is dominated by a hard power-law
component and radio observations indicate the presence of a steady and powerful
compact jet. Although the common hard state picture is that the accretion disk
is truncated, perhaps at hundreds of gravitational radii from the black hole,
recent results for the recurrent transient GX 339-4 by Miller and co-workers
show evidence for optically thick material very close to the black hole's
innermost stable circular orbit. That work focused on an observation of GX
339-4 at a luminosity of about 5% of the Eddington limit and used parameters
from a relativistic reflection model and the presence of a soft, thermal
component as diagnostics. In this work, we use similar diagnostics, but extend
the study to lower luminosities (2.3% and 0.8% Ledd) using Swift and RXTE
observations of GX 339-4. We detect a thermal component with an inner disk
temperature of ~0.2 keV at 2.3% Ledd. We detect broad features due to iron
Kalpha that are likely related to reflection of hard X-rays off the optically
thick material. If these features are broadened by relativistic effects, they
indicate that optically thick material resides within 10 Rg down to 0.8% Ledd,
and the measurements are consistent with the inner radius of the disk remaining
at ~4 Rg down to this level. However, we also discuss an alternative model for
the broadening, and we note that the evolution of the thermal component is not
entirely consistent with the constant inner radius interpretation. Finally, we
discuss the results in terms of recent theoretical work on the possibility that
material may condense to maintain an inner optically thick disk.


title:
Hole burning in polycrystalline C60: the final answer to the long
  pseudocoherent tails

abstract:
  New NMR experiments reveal the origin of the "pseudocoherence" that leads to
long tails in some Carr-Purcell-Meiboom-Gill (CPMG) sequences in contrast with
the decay of a standard Hahn echo. We showed in [M.B Franzoni and P.R.
Levstein, Phys. Rev. B 72, 235410 (2005)] that under certain conditions these
CPMG sequences become spoiled by stimulated echoes. The presence of these
echoes evidences that the long tails arise on the storage of magnetization in
the direction of the external magnetic field (z-polarization), involving
spin-lattice relaxation times of several seconds. Hole burning experiments
confirm the presence of a highly inhomogeneous line and show that the flip-flop
processes are able to homogenize the line in times agreeing with those obtained
through a Hahn echo sequence. As expected, the decay of the stimulated echoes
is not sensitive to the quenching of the dipolar interaction through an MREV16
sequence, while the Hahn echo decay increases by a factor of 20. CPMG sequences
with hard pulses and different temporal windows clearly show the relevance of
the dipolar interaction in between the pulses for the generation of the long
tails. In particular, the more time the flip-flop is effective (longer
interpulse separation), the shorter are the characteristic times of the long
tails.


title:
Line tensions, correlation lengths, and critical exponents in lipid
  membranes near critical points

abstract:
  Membranes containing a wide variety of ternary mixtures of high chain-melting
temperature lipids, low chain-melting temperature lipids, and cholesterol
undergo lateral phase separartion into coexisting liquid phases at a
miscibility transition. When membranes are prepared from a ternary lipid
mixture at a critical composition, they pass through a miscibility critical
point at the transition temperature. Since the critical temperature is
typically on the order of room temperature, membranes provide an unusual
opportunity in which to perform a quantitative study of biophysical systems
that exhibit critical phenomena in the two-dimensional Ising universality
class. As a critical point is approached from either high or low temperature,
the scale of fluctuations in lipid composition, set by the correlation length,
diverges. In addition, as a critical point is approached from low temperature,
the line tension between coexisting phases decreases to zero. Here we
quantitatively evaluate the temperature dependence of line tension between
liquid domains and of fluctuation correlation lengths in lipid membranes in
order to extract a critical exponent, nu. We obtain nu=1.2 plus or minus 0.2,
consistent with the Ising model prediction nu=1. We also evaluate the
probability distributions of pixel intensities in fluoresence images of
membranes. From the temperature dependence of these distributions above the
critical temperature, we extract an independent critical exponent beta=0.124
plus or minus 0.03 which is consistent with the Ising prediction of beta=1/8.


title: An abstract setting for hamiltonian actions

abstract:
  In this paper we develop an abstract setup for hamiltonian group actions as
follows: Starting with a continuous 2-cochain $\omega$ on a Lie algebra $h$
with values in an $h$-module $V$, we associate subalgebras $sp(h,\omega) \supeq
ham(h,\omega)$ of symplectic, resp., hamiltonian elements. Then $ham(h,\omega)$
has a natural central extension which in turn is contained in a larger abelian
extension of $sp(h,\omega)$. In this setting, we study linear actions of a Lie
group $G$ on $V$ which are compatible with a homomorphism $g \to
ham(h,\omega)$, i.e. abstract hamiltonian actions, corresponding central and
abelian extensions of $G$ and momentum maps $J : g \to V$.


title: A remark on primality testing and decimal expansions

abstract:
  We show that for any fixed base $a$, a positive proportion of primes have the
property that they become composite after altering any one of their digits in
the base $a$ expansion; the case $a=2$ was already established by
Cohen-Selfridge and Sun, using some covering congruence ideas of Erd\H{o}s. Our
method is slightly different, using a partially covering set of congruences
followed by an application of the Selberg sieve upper bound. As a consequence,
it is not always possible to test whether a number is prime from its base $a$
expansion without reading all of its digits. We also present some slight
generalisations of these results.


title:
Self accelerating solutions in a DGP brane with a scalar field trapped
  on it: the dynamical systems perspective

abstract:
  We apply the dynamical systems tools to study the linear dynamics of a
self-interacting scalar field trapped on a DGP brane. The simplest kinds of
self-interaction potentials are investigated: a) constant potential, and b)
exponential potential. It is shown that the dynamics of DGP models can be very
rich and complex. One of the most interesting results of this study shows that
dynamical screening of the scalar field self-interaction potential, occuring
within the Minkowski cosmological phase of the DGP model and mimetizing 4D
phantom behaviour, is an attractor solution for a constant self-interaction
potential but not for the exponential one. In the latter case gravitational
screening is not even a critical point of the corresponding autonomous system
of ordinary differential equations.


title: Evidence of thin helium envelopes in PG1159 stars

abstract:
  We present evidence that PG1159 stars could harbour He--rich envelopes
substantially thinner than those predicted by current evolutionary models with
current estimates of mass loss, which may be attributable to an extensive
mass--loss episode during the born--again AGB phase. Specifically, we show that
the models with thin He--rich envelopes predict remarkably large magnitudes of
the rates of period change of the trapped and untrapped modes observed in the
pulsating star PG 1159$-$035. This is a consequence of the much shorter
evolutionary timescale of the models with thin He--rich envelopes during the
low--gravity PG1159 regime. Our findings are particularly interesting in view
of the suggestion of an evolutionary link between the helium--deficient PG1159
star H1504+65 and the recently discovered white dwarfs with almost pure carbon
atmospheres.


title:
Evaluation and selection of models for out-of-sample prediction when the
  sample size is small relative to the complexity of the data-generating
  process

abstract:
  In regression with random design, we study the problem of selecting a model
that performs well for out-of-sample prediction. We do not assume that any of
the candidate models under consideration are correct. Our analysis is based on
explicit finite-sample results. Our main findings differ from those of other
analyses that are based on traditional large-sample limit approximations
because we consider a situation where the sample size is small relative to the
complexity of the data-generating process, in the sense that the number of
parameters in a `good' model is of the same order as sample size. Also, we
allow for the case where the number of candidate models is (much) larger than
sample size.


title: Simulation of high-spin Heisenberg models in coupled cavities

abstract:
  We propose a scheme to realize the Heisenberg model of any spin in an
arbitrary array of coupled cavities. Our scheme is based on a fixed number of
atoms confined in each cavity and collectively applied constant laser fields,
and is in a regime where both atomic and cavity excitations are suppressed. It
is shown that as well as optically controlling the effective spin Hamiltonian,
it is also possible to engineer the magnitude of the spin. Our scheme would
open up an unprecedented way to simulate otherwise intractable high-spin
problems in many-body physics.


title: The degeneracy of the genetic code and Hadamard matrices

abstract:
  The matrix form of the presentation of the genetic code is described as the
cognitive form to analyze structures of the genetic code. A similar matrix form
is utilized in the theory of signal processing. The Kronecker family of the
genetic matrices is investigated, which is based on the genetic matrix [C A; U
G], where C, A, U, G are the letters of the genetic alphabet. This matrix in
the third Kronecker power is the (8*8)-matrix, which contains 64 triplets.
Peculiarities of the degeneracy of the vertebrate mitochondria genetic code are
reflected in the symmetrical black-and-white mosaic of this genetic
(8*8)-matrix. This mosaic matrix is connected algorithmically with Hadamard
matrices unexpectedly, which are famous in the theory of signal processing,
spectral analysis, quantum mechanics and quantum computers. A special
decomposition of numeric genetic matrices reveals their close relations with a
family of 8-dimensional hypercomplex numbers (not Cayley's octonions). Some
hypothesis and thoughts are formulated on the basis of these phenomenological
facts.


title: Minijets, soft gluon resummation and photon cross-sections

abstract:
  We compare the high energy behaviour of hadronic photon-photon cross-sections
in different models. We find that the photon-photon cross-section appears to
rise faster than the purely hadronic ones (proton-proton and
proton-antiproton).


title:
A comparison of the s- and r-process element evolution in local dwarf
  spheroidal galaxies and in the Milky Way

abstract:
  We study the nucleosynthesis of several neutron capture elements (barium,
europium, lanthanum, and yttrium) in local group dwarf spheroidal (dSph)
galaxies and in the Milky Way by comparing the evolution of [Ba/Fe], [Eu/Fe],
[La/Fe], [Y/Fe], [Ba/Y], [Ba/Eu], [Y/Eu], and [La/Eu] observed in dSph galaxies
and in our Galaxy with predictions of detailed chemical evolution models. The
models for all dSph galaxies and for the Milky Way are able to reproduce
several observational features of these galaxies, such as a series of abundance
ratios and the stellar metallicities distributions. The Milky Way model adopts
the two-infall scenario, whereas the most important features of the models for
the dSph galaxies are the low star-formation rate and the occurrence of intense
galactic winds. We predict that the [s-r/Fe] ratios in dSphs are generally
different than the corresponding ratios in the Milky Way, at the same [Fe/H]
values. This is interpreted as a consequence of the time-delay model coupled
with different star formation histories. In particular, the star-formation is
less efficient in dSphs than in our Galaxy and it is influenced by strong
galactic winds. Our predictions are in very good agreement with the available
observational data. The time-delay model for the galactic chemical enrichment
coupled with different histories of star formation in different galaxies allow
us to succesfully interpret the observed differences in the abundance ratios of
s- and r- process elements, as well as of $\alpha$-elements in dSphs and in the
Milky Way. These differences strongly suggest that the main stellar populations
of these galaxies could not have had a common origin and, consequently, that
the progenitors of local dSphs might not be the same objects as the building
blocks of our Galaxy.


title: 3D Euler about a 2D Symmetry Plane

abstract:
  Initial results from new calculations of interacting anti-parallel Euler
vortices are presented with the objective of understanding the origins of
singular scaling presented by Kerr (1993) and the lack thereof by Hou and Li
(2006). Core profiles designed to reproduce the two results are presented, new
more robust analysis is proposed, and new criteria for when calculations should
be terminated are introduced and compared with classical resolution studies and
spectral convergence tests. Most of the analysis is on a $512 \times 128 \times
2048$ mesh, with new analysis on a just completed $1024 \times 256 \times 2048$
used to confirm trends. One might hypothesize that there is a finite-time
singularity with enstrophy growth like $\Omega \sim (T_c-t)^{-\gamma_\Omega}$
and vorticity growth like $||\omega||_\infty \sim (T_c-t)^{-\gamma}$. The new
analysis would then support $\gamma_\Omega \approx 1/2$ and $\gamma > 1$. These
represent modifications of the conclusions of Kerr (1993). Issues that might
arise at higher resolution are discussed.


title:
Time-Frequency Analysis of GALLEX and GNO Solar Neutrino Data: Evidence
  Suggestive of Asymmetric and Variable Nuclear Burning

abstract:
  Time-frequency analysis of data from the GALLEX and GNO solar neutrino
experiments shows that some features in power-spectrum analyses of those
datasets are due to aliasing. We normalize data for each of the four
experiments in the GALLEX series, concatenate the resulting normalized data,
and then form time-frequency displays. We also form time-frequency displays of
the two principal modulations found in the data, at 11.87 yr-1 and at 13.63
yr-1, and of the datasets formed by subtracting these modulations from the
actual (normalized) data. The results suggest that the true modulation is that
at 11.87 yr-1, consistent with the results of our earlier analysis of Homestake
solar neutrino data. Comparison with helioseismology data indicates that
modulation is occurring either in the radiative zone just below the tachocline,
presumably by the RSFP (resonant spin-flavor precession) process, or in the
core, presumably due to inhomogeneities and fluctuations in the nuclear-burning
process.


title: Chaotic diffusion in the Solar System

abstract:
  A statistical analysis is performed over more than 1001 different
integrations of the secular equations of the Solar system over 5 Gyr. With this
secular system, the probability of the eccentricity of Mercury to reach 0.6 in
5 Gyr is about 1 to 2 %. In order to compare with (Ito and Tanikawa, 2002), we
have performed the same analysis without general relativity, and obtained even
more orbits of large eccentricity for Mercury. We have performed as well a
direct integration of the planetary orbits, without averaging, for a dynamical
model that do not include the Moon or general relativity with 10 very close
initial conditions over 3 Gyr. The statistics obtained with this reduced set
are comparable to the statistics of the secular equations, and in particular we
obtain two trajectories for which the eccentricity of Mercury increases beyond
0.8 in less than 1.3 Gyr and 2.8 Gyr respectively. These strong instabilities
in the orbital motion of Mecury results from secular resonance beween the
perihelion of Jupiter and Mercury that are facilitated by the absence of
general relativity. The statistical analysis of the 1001 orbits of the secular
equations also provides probability density functions (PDF) for the
eccentricity and inclination of the terrestrial planets.


title: Elliptic surfaces without 1-handles

abstract:
  Harer-Kas-Kirby conjectured that every handle decomposition of the elliptic
surface E(1)_{2,3} requires both 1- and 3-handles. We prove that the elliptic
surface E(n)_{p,q} has a handle decomposition without 1-handles for $n\geq 1$
and (p,q)=(2,3),(2,5),(3,4),(4,5).


title: A-dependence of phi-meson production in p+A collisions

abstract:
  A systematic analysis of the A-dependence of phi-meson production in
proton-nucleus collisions is presented. We apply different formalisms for the
evaluation of the phi-meson distortion in nuclei and discuss the theoretical
uncertainties of the data analysis. The corresponding results are compared to
theoretical predictions. We also discuss the interpretation of the extracted
results with respect to different observables and provide relations between
frequently used definitions. The perspectives of future experiments are
evaluated and estimates based on our systematical study are given.


title:
Iterative real-time path integral approach to nonequilibrium quantum
  transport

abstract:
  We have developed a numerical approach to compute real-time path integral
expressions for quantum transport problems out of equilibrium. The scheme is
based on a deterministic iterative summation of the path integral (ISPI) for
the generating function of the nonequilibrium current. Self-energies due to the
leads, being non-local in time, are fully taken into account within a finite
memory time, thereby including non-Markovian effects, and numerical results are
extrapolated both to vanishing (Trotter) time discretization and to infinite
memory time. This extrapolation scheme converges except at very low
temperatures, and the results are then numerically exact. The method is applied
to nonequilibrium transport through an Anderson dot.


title:
Edge ideals of clique clutters of comparability graphs and the normality
  of monomial ideals

abstract:
  Let (P,<) be a finite poset and let G be its comparability graph. If cl(G) is
the clutter of maximal cliques of G, we prove that cl(G) satisfies the max-flow
min-cut property and that its edge ideal is normally torsion free. We prove
that edge ideals of complete admissible uniform clutters are normally torsion
free. The normality of a monomial ideal is expressed in terms of blocking
polyhedra and the integer decomposition property. For edge ideals of clutters
this property completely determine their normality


title:
Constructing new Calabi-Yau 3-folds and their mirrors via conifold
  transitions

abstract:
  We construct a surprisingly large class of new Calabi-Yau 3-folds $X$ with
small Picard numbers and propose a construction of their mirrors $X^*$ using
smoothings of toric hypersurfaces with conifold singularities. These new
examples are related to the previously known ones via conifold transitions. Our
results generalize the mirror construction for Calabi-Yau complete
intersections in Grassmannians and flag manifolds via toric degenerations.
There exist exactly 198849 reflexive 4-polytopes whose 2-faces are only
triangles or parallelograms of minimal volume. Every such polytope gives rise
to a family of Calabi-Yau hypersurfaces with at worst conifold singularities.
Using a criterion of Namikawa we found 30241 reflexive 4-polytopes such that
the corresponding Calabi-Yau hypersurfaces are smoothable by a flat
deformation. In particular, we found 210 reflexive 4-polytopes defining 68
topologically different Calabi--Yau 3-folds with $h_{11}=1$. We explain the
mirror construction and compute several new Picard--Fuchs operators for the
respective 1-parameter families of mirror Calabi-Yau 3-folds.


title: Lepton Number-Driven Sterile Neutrino Production in the Early Universe

abstract:
  We examine medium-enhanced, neutrino scattering-induced decoherent production
of dark matter candidate sterile neutrinos in the early universe. In cases with
a significant net lepton number we find two resonances, where the effective
in-medium mixing angles are large. We calculate the lepton number
depletion-driven evolution of these resonances. We describe the dependence of
this evolution on lepton numbers, sterile neutrino rest mass, and the
active-sterile vacuum mixing angle. We find that this resonance evolution can
result in relic sterile neutrino energy spectra with a generic form which is
sharply peaked in energy. We compare our complete quantum kinetic equation
treatment with the widely-used quantum Zeno ansatz.


title:
Minimal Dark Matter predictions for galactic positrons, anti-protons,
  photons

abstract:
  We present the energy spectra of the fluxes of positrons, anti-protons and
photons generated by Dark Matter annihilations in our galaxy, as univocally
predicted by the model of Minimal Dark Matter. Due to multi-TeV masses and to
the Sommerfeld enhancement of the annihilation cross section, distinctive
signals are generated above the background, even with a modest astrophysical
boost factor, in the range of energies soon to be explored by cosmic ray
experiments.


title: Cosmic Superstrings

abstract:
  Cosmic superstrings are expected to be formed at the end of brane inflation,
within the context of brane-world cosmological models inspired from string
theory. By studying properties of cosmic suprestring networks, and comparing
their phenomenological consequences against observational data, we aim at
pinning down the successful and natural inflationary model and get an insight
into the stringy description of our universe.


title:
A solvable model of the genesis of amino-acid sequences via coupled
  dynamics of folding and slow genetic variation

abstract:
  We study the coupled dynamics of primary and secondary structure formation
(i.e. slow genetic sequence selection and fast folding) in the context of a
solvable microscopic model that includes both short-range steric forces and and
long-range polarity-driven forces. Our solution is based on the diagonalization
of replicated transfer matrices, and leads in the thermodynamic limit to
explicit predictions regarding phase transitions and phase diagrams at genetic
equilibrium. The predicted phenomenology allows for natural physical
interpretations, and finds satisfactory support in numerical simulations.


title: Soft and collinear enhancements to top quark and Higgs cross sections

abstract:
  I present calculations of soft and collinear corrections to the cross
sections for single top quark production, and for Higgs production via b bbar
-> H at the Tevatron and the LHC. I show that the corrections provide
significant enhancements to the cross sections in both cases. For single top
production the soft gluon corrections dominate the cross section, particularly
in the s channel and in tW production. For Higgs production it is shown that
purely collinear terms have to be included as well to provide an accurate
calculation.


title:
Study of Short-distance Spin and Charge Correlations and Local
  Density-of-States in the CMR regime of the One-Orbital Model for Manganites

abstract:
  The metal-insulator transition, and the associated magnetic transition, in
the colossal magnetoresistance (CMR) regime of the one-orbital model for
manganites is here studied using Monte Carlo (MC) techniques. Both cooperative
oxygen lattice distortions and a finite superexchange coupling among the
$t_{\rm 2g}$ spins are included in our investigations. Charge and spin
correlations are studied. In the CMR regime, a strong competition between the
ferromagnetic metallic and antiferromagnetic charge-ordered insulating states
is observed. This competition is shown to be important to understand the
resistivity peak that appears near the critical temperature. Moreover, it is
argued that the system is dynamically inhomogeneous, with short-range charge
and spin correlations that slowly evolve with MC time, producing the glassy
characteristics of the CMR state. The local density-of-states (LDOS) is also
investigated, and a pseudogap (PG) is found to exist in the CMR temperature
range. The width of the PG in the LDOS is calculated and directly compared with
recent scanning-tunneling-spectroscopy (STS) experimental results. The
agreement between our calculation and the experiment suggests that the
depletion of the conductance at low bias observed experimentally is a
reflection on the existence of a PG in the LDOS spectra, as opposed to a hard
gap. The apparent homogeneity observed via STS techniques could be caused by
the slow time characteristics of this probe. Faster experimental methods should
unveil a rather inhomogeneous state in the CMR regime, as already observed in
neutron scattering experiments.


title: Dynamical coupled channel calculation of pion and omega meson production

abstract:
  A dynamical coupled channel approach is used to study $\pi$ and
$\omega$--meson production induced by pions and photons scattering from the
proton. Six intermediate channels including $\pi N$, $\eta N$, $\pi\Delta$,
$\sigma N$, $\rho N$ and $\omega N$ are employed to describe unpolarized and
polarized data. Bare parameters in an effective hadronic Lagrangian are
determined in a fit to data for $\pi N \to \pi N$, $\gamma N \to \pi N$, $\pi^-
p \to \omega n$, and $\gamma p \to \omega p$ reactions at center-of-mass
energies from threshold to $W < 2.0$ GeV. The $T$ matrix determined in these
fits is used to calculate the photon beam asymmetry for $\omega$-meson
production and the $\omega N \to\omega N$ total cross section and $\omega N$
scattering lengths.


title:
Collider signals and neutralino dark matter detection in
  relic-density-consistent models without universality

abstract:
  We present brief synopses of supersymmetric models where either the
neutralino composition or its mass is adjusted so that thermal relic
neutralinos from the Big Bang saturate the measured abundance of cold dark
matter in the universe. We first review minimal supergravity (mSUGRA), and then
examine its various one-parameter extensions where we relax the assumed
universality of the soft supersymmetry breaking parameters. Our goal is to
correlate relic-density-allowed parameter choices with expected phenomena in
direct, indirect and collider dark matter search experiments. For every
non-universal model, we first provide plots to facilitate the selection of
``dark-matter allowed'' parameter space points, and then present salient
features of each model with respect to searches at Tevatron, LHC and ILC and
also direct and indirect dark matter searches. We present benchmark scenarios
that allow one to compare and contrast the non-universal models with one
another and with the paradigm mSUGRA framework. We show that many implications
about sparticle properties and collider signals drawn from the analysis of the
relic density constraint within mSUGRA do not carry over to simple
one-parameter extensions of the mSUGRA framework. We find that in many
relic-density-consistent models, there is one (or more) detectable edge in the
invariant mass distribution of same-flavour, opposite sign dileptons in SUSY
cascade decay events at the LHC. Finally, we scan the parameter space of these
various models, requiring consistency with the LEP2 constraint on the chargino
mass, and with the observed relic density, and examine prospects for direct and
indirect dark matter detection. We find that in a large number of cases the
mechanism that causes the early universe neutralino annihilation rate to be
large (so as to produce the measured relic density) also enhances the direct
detection rate, and often also the rates for indirect detection of neutralino
dark matter.


title:
Analytical infrared intensities for periodic systems with local basis
  sets

abstract:
  We report a method for the efficient evaluation of analytic infrared (IR)
intensities within generalized Kohn-Sham density functional theory using
Gaussian orbitals and periodic boundary conditions. A discretized form of the
Berry phase is used to evaluate a periodic dipole moment and its derivatives
with respect to in-phase nuclear coordinate displacements. Benchmark
calculations are presented for one-dimensional chains of water molecules and
poly(paraphenylenevinylene).


title: Recent advances in pulsed-laser deposition of complex-oxides

abstract:
  Pulsed-laser deposition (PLD) is one of the most promising techniques for the
formation of complex-oxide heterostructures, superlattices, and well-controlled
interfaces. The first part of this paper presents a review of several useful
modifications of the process, including methods inspired by combinatorial
approaches. We then discuss detailed growth kinetics results, which illustrate
that 'true' layer-by-layer (LBL) growth can only be approached, but not fully
met, even though many characterization techniques reveal interfaces with
unexpected sharpness. Time-resolved surface x-ray diffraction measurements show
that crystallization and the majority of interlayer mass transport occur on
time scales that are comparable to those of the plume/substrate interaction,
providing direct experimental evidence that a growth regime exists in which
non-thermal processes dominate PLD. This understanding shows how kinetic growth
manipulation can bring PLD closer to ideal LBL than any other growth method
available today.


title: An alternative method to study star cluster disruption

abstract:
  Many embedded star clusters do not evolve into long-lived bound clusters. The
most popular explanation for this "infant mortality" of young clusters is the
expulsion of natal gas by stellar winds and supernovae, which leaves up to 90%
of them unbound. A cluster disruption model has recently been proposed in which
this mass- independent disruption of clusters proceeds for another Gyr after
gas expulsion. In this scenario, the survival chances of massive clusters are
much smaller than in the traditional mass-dependent disruption models. The most
common way to study cluster disruption is to use the cluster age distribution,
which, however, can be heavily affected by incompleteness. To avoid this, we
introduce a new method, based on size-of-sample effects, namely the relation
between the most massive cluster, M_max, and the age range sampled. Assuming
that clusters are sampled from a power-law initial mass function, with index -2
and that the cluster formation rate is constant, M_max scales with the age
range sampled, such that the slope in a log(M_max) vs. log(age) plot is equal
to unity. This slope decreases if mass-independent disruption is included. For
90% mass-independent cluster disruption per age dex, the predicted slope is
zero. For the solar neighbourhood, SMC, LMC, M33, and M83, based on ages and
masses taken from the literature, we find slopes consistent with the expected
size-of-sample correlations for the first 100 Myr, hence ruling out the 90%
mass-independent cluster disruption scenario. For M51, however, the increase of
log(M_max) with log(age) is slightly shallower and for the Antennae galaxies it
is flat. This simple method shows that the formation and/or disruption of
clusters in the Antennae must have been very different from that of the other
galaxies studied here, so it should not be taken as a representative case.


title: On the nature of the X-ray pulsar SAX J1324-6200

abstract:
  We present recent observations of the X-ray pulsar SAX J1324-6200 obtained in
December 2007 with the Swift satellite yielding a significant improvement in
the source localization with respect to previous data and a new measurement of
the spin period P=172.84s. A single object consistent in colors with a highly
reddened early type star is visible in the X-ray error box. The period is
significantly longer than that obtained in 1997, indicating that SAX J1324-6200
has been spinning down at an average rate of ~6x10^-9 s s^-1. We discuss the
possible nature of the source showing that it most likely belongs to the class
of low luminosity, persistent Be/neutron star binaries.


title: Simplicity and closure constraints in spin foam models of gravity

abstract:
  We revise imposition of various constraints in spin foam models of
4-dimensional general relativity. We argue that the usual simplicity constraint
must be supplemented by a constraint on holonomies and together they must be
inserted explicitly into the discretized path integral. At the same time, the
closure constraint must be relaxed so that the new constraint expresses
covariance of intertwiners assigned to tetrahedra by spin foam quantization. As
a result, the spin foam boundary states are shown to be realized in terms of
projected spin networks of the covariant loop approach to quantum gravity.


title: Radiative Damping and Functional Differential Equations

abstract:
  We propose a general technique to solve the classical many-body problem with
radiative damping. We modify the short-distance structure of Maxwell
electrodynamics. This allows us to avoid runaway solutions as if we had a
covariant model of extended particles. The resulting equations of motion are
functional differential equations (FDEs) rather than ordinary differential
equations. Using recently developed numerical techniques for stiff FDEs, we
solve these equations for the one-body central force problem with radiative
damping with a view to benchmark our new approach. Our results indicate that
locally the magnitude of radiation damping may be well approximated by the
standard third-order expression but the global properties of our solutions are
dramatically different. We comment on the two body problem and applications to
quantum field theory and quantum mechanics.


title: GUTs and Exceptional Branes in F-theory - I

abstract:
  Motivated by potential phenomenological applications, we develop the
necessary tools for building GUT models in F-theory. This approach is quite
flexible because the local geometrical properties of singularities in F-theory
compactifications encode the physical content of the theory. In particular, we
show how geometry determines the gauge group, matter content and Yukawa
couplings of a given model. It turns out that these features are beautifully
captured by a four-dimensional topologically twisted N=4 theory which has been
coupled to a surface defect theory on which chiral matter can propagate. From
the vantagepoint of the four-dimensional topological theory, these defects are
surface operators. Specific intersection points of these defects lead to Yukawa
couplings. We also find that the unfolding of the singularity in the F-theory
geometry precisely matches to properties of the topological theory with a
defect.


title: Single-atom aided probe of the decoherence of a Bose-Einstein condensate

abstract:
  We study a two-level atom coupled to a Bose-Einstein condensate. We show that
the rules governing the decoherence of mesoscopic superpositions involving
different classical-like states of the condensate can be probed using this
system. This scheme is applicable irrespective of whether the condensate is
initially in a coherent, thermal or more generally in any mixture of coherent
states. The effects of atom loss and finite temperature to the decoherence can
therefore be studied. We also discuss the various noise sources causing the
decoherence.


title: Is noncommutativity related with the smallness of $\Lambda$?

abstract:
  In this letter we study the effects of a noncommutative minisuperspace,
including matter degrees of freedom on a FRW universe with cosmological
constant. In this setting the vacuum energy density can be calculated to be of
the same order as the observed energy density of the universe.


title:
Fermi Arcs in the Superconducting Clustered State for Underdoped
  Cuprates

abstract:
  The one-particle spectral function of a state formed by superconducting (SC)
clusters is studied via Monte Carlo techniques. The clusters have similar SC
amplitudes but randomly distributed phases. This state is stabilized by the
competition with anti-ferromagnetism, after quenched disorder is introduced.
Fermi arcs between the critical temperature Tc and the cluster formation
temperature scale T* are observed, similarly as in the pseudo-gap state of the
cuprates. The arcs originate at metallic regions in between the neighboring
clusters that present large SC phase differences.


title:
Thermodynamics of Heisenberg ferromagnets with arbitrary spin in a
  magnetic field

abstract:
  The thermodynamic properties (magnetization, magnetic susceptibility,
transverse and longitudinal correlation lengths, specific heat) of one- and
two-dimensional ferromagnets with arbitrary spin S in a magnetic field are
investigated by a second-order Green-function theory. In addition, quantum
Monte Carlo simulations for S= 1/2 and S=1 are performed using the stochastic
series expansion method. A good agreement between the results of both
approaches is found. The field dependence of the position of the maximum in the
temperature dependence of the susceptibility fits well to a power law at low
fields and to a linear increase at high fields. The maximum height decreases
according to a power law in the whole field region. The longitudinal
correlation length may show an anomalous temperature dependence: a minimum
followed by a maximum with increasing temperature. Considering the specific
heat in one dimension and at low magnetic fields, two maxima in its temperature
dependence for both the S= 1/2 and S = 1 ferromagnets are found. For S>1 only
one maximum occurs, as in the two-dimensional ferromagnets. Relating the theory
to experiments on the S= 1/2 quasi-one-dimensional copper salt TMCuC
[(CH_3)_4NCuCl_3], a fit to the magnetization as a function of the magnetic
field yields the value of the exchange energy which is used to make predictions
for the occurrence of two maxima in the temperature dependence of the specific
heat.


title: Generalized Tests for Selection Effects in GRB High-Energy Correlations

abstract:
  Several correlations among parameters derived from modelling the high-energy
properties of GRBs have been reported. We show that well-known examples of
these have common features indicative of strong contamination by selection
effects. We focus here on the impact of detector threshold truncation on the
spectral peak versus isotropic equivalent energy release ($E_{\rm pk}$-$E_{\rm
iso}$) relation, extended to a large sample of 218 Swift and 56 HETE-2 GRBs
with and without measured redshift. The existence of faint Swift events missing
from pre-Swift surveys calls into question inferences based on pre-Swift
surveys which must be subject to complicated incompleteness effects. We
demonstrate a generalized method for treating data truncation in correlation
analyses and apply this method to Swift and pre-Swift data. Also, we show that
the $E_{\rm pk}$-$E_{\gamma}$ ("Ghirlanda") correlation is effectively
independent of the GRB redshifts, which suggests its existence has little to do
with intrinsic physics. We suggest that a physically-based correlation,
manifest observationally, must show significantly reduced scatter in the rest
frame relative to the observer frame and must not persist if the assumed
redshifts are scattered. As with the $E_{\rm pk}$-$E_{\gamma}$ correlation, we
find that the pre-Swift, bright GRB $E_{\rm pk}$-$E_{\rm iso}$ correlation of
\citet{amati06} does not rigorously satisfy these conditions.


title: A Lossy Bosonic Quantum Channel with Non-Markovian Memory

abstract:
  We provide a simple and realistic model to study memory effects in a lossy
bosonic quantum channel over arbitrary number of uses. The noise correlation
among different uses is introduced by contiguous modes interactions which
results in an exponential decay of the correlations over channel uses (modes).
This model allows us to characterize the asymptotic behavior of the channel for
classical information transmission.


title: Calibration of a digital hadron calorimeter with muons

abstract:
  The calibration procedure of a finely granulated digital hadron calorimeter
with Resistive Plate Chambers as active elements is described. Results obtained
with a stack of nine layers exposed to muons from the Fermilab test beam are
presented.


title: Evidence for R-Mode Oscillations in Super-Kamiokande Solar Neutrino Data

abstract:
  There has for some time been evidence of variability in radiochemical solar
neutrino measurements, but this evidence has seemed suspect since the cerenkov
experiments have not shown similar evidence of variability. The present
re-analysis of Super-Kamiokande data shows strong evidence of r-mode
oscillations. The frequencies of these oscillations correspond to a region with
a sidereal rotation rate of 13.97 year-1, not far from the value 13.88 year-1
found some time ago in Homestake data, or 13.87 year-1 found recently in GALLEX
data. These estimates are incompatible with the rotation rate in the convection
zone, but fully compatible with current estimates of the rotation rate in the
radiative zone, including the solar core. These results are suggestive of
variability originating in the core from fluctuating and asymmetric nuclear
burning.


title:
Entropic bounds on semiclassical measures for quantized one-dimensional
  maps

abstract:
  Quantum ergodicity asserts that almost all infinite sequences of eigenstates
of a quantized ergodic system are equidistributed in the phase space. On the
other hand, there are might exist exceptional sequences which converge to
different (non-Liouville) classical invariant measures. By the remarkable
result of N. Anantharaman and S. Nonnenmacher math-ph/0610019, arXiv:0704.1564
(with H. Koch), for Anosov geodesic flows the metric entropy of any
semiclassical measure must be bounded from below. The result seems to be
optimal for uniformly expanding systems, but not in general case, where it
might become even trivial if the curvature of the Riemannian manifold is
strongly non-uniform. It has been conjectured by the same authors, that in
fact, a stronger bound (valid in general case) should hold.
  In the present work we consider such entropic bounds using the model of
quantized one-dimensional maps. For a certain class of non-uniformly expanding
maps we prove Anantharaman-Nonnenmacher conjecture. Furthermore, for these maps
we are able to construct some explicit sequences of eigenstates which saturate
the bound. This demonstrates that the conjectured bound is actually optimal in
that case.


title:
On the Structure of the Capacity Region of Asynchronous Memoryless
  Multiple-Access Channels

abstract:
  The asynchronous capacity region of memoryless multiple-access channels is
the union of certain polytopes. It is well-known that vertices of such
polytopes may be approached via a technique called successive decoding. It is
also known that an extension of successive decoding applies to the dominant
face of such polytopes. The extension consists of forming groups of users in
such a way that users within a group are decoded jointly whereas groups are
decoded successively. This paper goes one step further. It is shown that
successive decoding extends to every face of the above mentioned polytopes. The
group composition as well as the decoding order for all rates on a face of
interest are obtained from a label assigned to that face. From the label one
can extract a number of structural properties, such as the dimension of the
corresponding face and whether or not two faces intersect. Expressions for the
the number of faces of any given dimension are also derived from the labels.


title: On secant varieties of Compact Hermitian Symmetric Spaces

abstract:
  We show that the secant varieties of rank three compact Hermitian symmetric
spaces in their minimal homogeneous embeddings are normal, with rational
singularities. We show that their ideals are generated in degree three - with
one exception, the secant variety of the $21$-dimensional spinor variety in
$\pp{63}$ where we show the ideal is generated in degree four. We also discuss
the coordinate rings of secant varieties of compact Hermitian symmetric spaces.


title: Goldman flows on the Jacobian

abstract:
  We show that the Goldman flows preserve the holomorphic structure on the
moduli space of homomorphisms of the fundamental group of a Riemann surface
into U(1), in other words the Jacobian.


title:
Finite-time Singularities in Surface-Diffusion Instabilities are Cured
  by Plasticity

abstract:
  A free material surface which supports surface diffusion becomes unstable
when put under external non-hydrostatic stress. Since the chemical potential on
a stressed surface is larger inside an indentation, small shape fluctuations
develop because material preferentially diffuses out of indentations. When the
bulk of the material is purely elastic one expects this instability to run into
a finite-time cusp singularity. It is shown here that this singularity is cured
by plastic effects in the material, turning the singular solution to a regular
crack.


title:
Breakdown of Fermi Liquid Theory in Doped Mott Insulators by Dynamical
  Spectral Weight Transfer

abstract:
  We show that doped Mott insulators exhibit a collective degree of freedom,
not made out of the elemental excitations, because the number of
single-particle addition states at low energy per electron per spin is greater
than one. The presence of such a collective degree of freedom which is not a
consequence of proximity to a phase transition is a consequence of dynamical
spectral weight transfer from high to low energies. This physics is captured by
the charge $2e$ boson that emerges by explicitly integrating out the
high-energy scale in the Hubbard model. The charge $2e$ boson binds to a hole,
thereby mediating new charge $e$ states at low energy. It is the presence of
such charge $e$ states which have no counterpart in the non-interacting system
that provides the general mechanism for the breakdown of Fermi liquid theory in
doped Mott insulators. The relationship between the charge $2e$ boson
formulation and the standard perturbative treatment is explained.


title: Thermonuclear Dynamo inside an Alfven Black Hole

abstract:
  As in an acoustic black hole where the fluid is moving faster than the speed
of sound and where the sound waves are swept along, in an Alfven black hole the
plasma is moving faster than the Alfven velocity, with the Alfven waves swept
along and eliminated as the cause of the magneto hydrodynamic instabilities. To
realize an Alfven black hole, it is proposed to bring a plasma into rapid
rotation by radially arranged lumped parameter transmission lines intersecting
the plasma under an oblique angle. The rotating plasma slides frictionless over
magnetic mirror fields directed towards the rotating plasma, with the mirror
fields generated by magnetic solenoids positioned at the end of each
transmission line. It is then shown that, with this configuration one can
realize a thermonuclear dynamo, which also can serve as the analogue of a
magnetar.


title:
The Strominger-Yau-Zaslow conjecture: From torus fibrations to
  degenerations

abstract:
  This survey article begins with a discussion of the original form of the
Strominger-Yau-Zaslow conjecture, surveys the state of knowledge concering this
conjecture, and explains how thinking about this conjecture naturally leads to
the program initiated by the author and Bernd Siebert to study mirror symmetry
via degenerations of Calabi-Yau manifolds and log structures.


title:
Conjectured Metastable Super-Explosives formed under High Pressure for
  Thermonuclear Ignition

abstract:
  If matter is suddenly put under a high pressure, for example a pressure of
100 Mb =10^14 dyn/cm^2, it can undergo a transformation into molecular excited
states, bound by inner electron shells, with keV potential well for the
electrons. If this happens, the electrons can under the emission of X-rays go
into the groundstate of the molecule formed under the high pressure. At a
pressure of the order ~ 10^14 dyn/cm^2, these molecules store in their excited
states an energy with an energy density of the order ~ 10^14 erg/cm^3, about
thousand times larger than for combustible chemicals under normal pressures.
Furthermore, with the much larger optical path length of keV photons compared
to the path length of eV photons, these superexplosives can reach at their
surface an energy flux density (c=3x10^10 cm/s) of the order (c/3)x10^14 =
10^24 erg/cm^2s^(-1) = 10^17 W/cm^2, large enough for the ignition of
thermonuclear reactions.


title: Integrals over SU(N)

abstract:
  In this paper we calculate a number of integrals over SU(N) of interest in
Hamiltonian Lattice Gauge Theory calculations.


title: Moment problems and boundaries of number triangles

abstract:
  The boundary problem for graphs like Pascal's but with general multiplicities
of edges is related to a `backward' problem of moments of the Hausdorff type.


title:
Detecting Planets around Compact Binaries with Gravitational Wave
  Detectors in Space

abstract:
  I propose a method to detect planets around compact binaries that are strong
sources of gravitational radiation. This approach is to measure
gravitational-wave phase modulations induced by the planets, and its prospect
is studied with a Fisher matrix analysis. I find that, using the Laser
Interferometer Space Antenna (LISA), planets can be searched for around ~3000
Galactic double white dwarfs with detection limit ~4 M_J (M_J~ 2x10^{30}g: the
Jupiter mass). With its follow-on missions, planets with mass ~1 M_J might be
detected around double neutron stars even at cosmological distances z~1. In
this manner, gravitational wave observation has potential to make interesting
contributions to extra-solar planetary science.


title:
Structure of T modules and restricted duals: the classical and the
  quantum case

abstract:
  A concrete realization of Enright's $T$ modules is obtained. This is used to
show their self-duality. As a consequence, the restricted duals of Verma
modules are also identified.


title:
On multiplicity problems for finite-dimensional representations of hyper
  loop algebras

abstract:
  Given a hyper loop algebra over a non-algebraically closed field, we address
multiplicity problems in the underlying abelian tensor category of
finite-dimensional representations. Namely, we give formulas for the
l-characters of the simple objects, the Jordan-Holder multiplicities of the
Weyl modules, and the Clebsch-Gordan coefficients.


title: Universal Reconfiguration of (Hyper-)cubic Robots

abstract:
  We study a simple reconfigurable robot model which has not been previously
examined: cubic robots comprised of three-dimensional cubic modules which can
slide across each other and rotate about each others' edges. We demonstrate
that the cubic robot model is universal, i.e., that an n-module cubic robot can
reconfigure itself into any specified n-module configuration. Additionally, we
provide an algorithm that efficiently plans and executes cubic robot motion.
Our results directly extend to a d-dimensional model.


title: The sutured Floer homology polytope

abstract:
  In this paper, we extend the theory of sutured Floer homology developed by
the author. We first prove an adjunction inequality, and then define a polytope
P(M,g) in H^2(M,\partial M; R) that is spanned by the Spin^c-structures which
support non-zero Floer homology groups. If (M,g) --> (M',g') is a taut surface
decomposition, then a natural map projects P(M',g') onto a face of P(M,g);
moreover, if H_2(M) = 0, then every face of P(M,g) can be obtained in this way
for some surface decomposition. We show that if (M,g) is reduced, horizontally
prime, and H_2(M) = 0, then P(M,g) is maximal dimensional in H^2(M,\partial M;
R). This implies that if rk(SFH(M,g)) < 2^{k+1} then (M,g) has depth at most
2k. Moreover, SFH acts as a complexity for balanced sutured manifolds. In
particular, the rank of the top term of knot Floer homology bounds the
topological complexity of the knot complement, in addition to simply detecting
fibred knots.


title: Fractal Substructure of a Nanopowder

abstract:
  The structural evolution of a nano-powder by repeated dispersion and settling
can lead to characteristic fractal substructures. This is shown by numerical
simulations of a two-dimensional model agglomerate of adhesive rigid particles.
The agglomerate is cut into fragments of a characteristic size l, which then
are settling under gravity. Repeating this procedure converges to a loosely
packed structure, the properties of which are investigated: a) The final
packing density is independent of the initialization, b) the short-range
correlation function is independent of the fragment size, c) the structure is
fractal up to the fragmentation scale l with a fractal dimension close to 1.7,
and d) the relaxation time increases linearly with l.


title: Reduced density matrices and coherence of trapped interacting bosons

abstract:
  The first- and second-order correlation functions of trapped, interacting
Bose-Einstein condensates are investigated numerically on a many-body level
from first principles. Correlations in real space and momentum space are
treated. The coherence properties are analyzed. The results are obtained by
solving the many-body Schr\"odinger equation. It is shown in an example how
many-body effects can be induced by the trap geometry. A generic fragmentation
scenario of a condensate is considered. The correlation functions are discussed
along a pathway from a single condensate to a fragmented condensate. It is
shown that strong correlations can arise from the geometry of the trap, even at
weak interaction strengths. The natural orbitals and natural geminals of the
system are obtained and discussed. It is shown how the fragmentation of the
condensate can be understood in terms of its natural geminals. The many-body
results are compared to those of mean-field theory. The best solution within
mean-field theory is obtained. The limits in which mean-field theories are
valid are determined. In these limits the behavior of the correlation functions
is explained within an analytical model.


title:
A New Proof for Classification of Irreducible Modules of a Hecke Algebra
  of Type $ A_n$

abstract:
  In this paper we give a new proof for the classification of irreducible
modules of an affine Hecke algebra of type $A_n$, which was obtained by G. E.
Murphy in 1995.


title:
Randomized Frameproof Codes: Fingerprinting Plus Validation Minus
  Tracing

abstract:
  We propose randomized frameproof codes for content protection, which arise by
studying a variation of the Boneh-Shaw fingerprinting problem. In the modified
system, whenever a user tries to access his fingerprinted copy, the fingerprint
is submitted to a validation algorithm to verify that it is indeed permissible
before the content can be executed. We show an improvement in the achievable
rates compared to deterministic frameproof codes and traditional fingerprinting
codes.
  For coalitions of an arbitrary fixed size, we construct randomized frameproof
codes which have an $O(n^2)$ complexity validation algorithm and probability of
error $\exp(-\Omega(n)),$ where $n$ denotes the length of the fingerprints.
Finally, we present a connection between linear frameproof codes and minimal
vectors for size-2 coalitions.


title:
A general theory of inhomogeneous broadening for nonlinear
  susceptibilities: polarizability and hyperpolarizability

abstract:
  While nonlinear optical spectroscopy is becoming more commonly used to study
the excited states of nonlinear-optical systems, a general theory of
inhomogeneous broadening is rarely applied in lieu of either a simple
Lorentzian or Gaussian model. In this work, we generalize all the important
linear and second-order nonlinear susceptibility expressions obtained with
sum-over state quantum calculations to include Gaussian and stretched Gaussian
distributions of Lorentzians. We show that using the correct model to analyze
experiments that probe a limited wavelength range can be critical and that this
theory is better able to fit the subtle spectral features - such as the
shoulder region of a resonance - when both models produce qualitatively similar
responses.


title:
A general theory of inhomogeneous broadening for nonlinear
  susceptibilities: the second hyperpolarizability

abstract:
  A general theory of inhomogeneous broadening is rarely applied to nonlinear
spectroscopy in lieu of either a simple Lorentzian or Gaussian model. In this
work, we generalize all the important third-order nonlinear susceptibility
expressions obtained with sum-over state quantum calculations to include
Gaussian and stretched Gaussian distributions of Lorentzians. This theory gives
a better fit to subtle spectral features - such as the shoulder of the
electroabsorption peak, and is a more accurate tool for determining transition
moments from spectroscopy experiments.


title: Black Holes without Event Horizons

abstract:
  We discuss some of the drawbacks of using event horizons to define black
holes. The reasons are both practical, physical and theoretical. We argue that
locally defined trapping horizons can remedy many of these drawbacks. We
examine of the question of whether black hole thermodynamics should be
associated with event horizons or trapping horizons. To this end we discuss
what role trapping horizons may play in black hole thermodynamics. In addition,
we show how trapping horizons may give rise to Hawking radiation and discuss
the issue of gravitational entropy.


title:
Correlations in the properties of static and rapidly rotating compact
  stars

abstract:
  Correlations in the properties of the static compact stars (CSs) and the ones
rotating with the highest observed frequency of 1122Hz are studied using a
large set of equations of state (EOSs). These EOSs span various approaches and
their chemical composition vary from the nucleons to hyperons and quarks in
$\beta$-equilibrium. It is found that the properties of static CS, like, the
maximum gravitational mass $M_{\rm max}^{\rm stat}$ and radius $R_{1.4}^{\rm
stat}$ corresponding to t he canonical mass and supramassive or
non-supramassive nature of the CS rotating at 1122 Hz are strongly correlated.
In particular, only those EOSs yield the CS rotating at 1122Hz to be
non-supramassive for which $\left (\frac{M_{\rm max}^{\rm stat}}{M_\odot}\right
)^{1/2} \left (\frac{10{\rm km}}{R_{1.4}^{\rm stat}})^{3/2} $ is greater than
unity. Suitable parametric form which can be used to split the $M_{\rm
max}^{\rm stat}$ $-$ $R_{1.4}^{\rm stat}$ plane into the regions of different
supramassive nature of the CS rotating at 1122Hz is presented. Currently
measured maximum gravitational mass 1.76$M_\odot$ of PSR J0437-4715 suggests
that the CS rotating at 1122Hz can be non-supramassive provided $R_{1.4}^{\rm
stat} \leqslant 12.4$ km.


title: Property of Tsallis entropy and principle of entropy increase

abstract:
  The property of Tsallis entropy is examined when considering tow systems with
different temperatures to be in contact with each other and to reach the
thermal equilibrium. It is verified that the total Tsallis entropy of the two
systems cannot decrease after the contact of the systems. We derived an
inequality for the change of Tsallis entropy in such an example, which leads to
a generalization of the principle of entropy increase in the framework of
nonextensive statistical mechanics.


title:
Detection of diffuse radio emission at large distance from the center of
  the galaxy cluster A2255

abstract:
  Low-frequency radio observations of galaxy clusters are the key to detecting
the diffuse extended emission associated with them. The presence and properties
of such radio sources in galaxy clusters reveal the existence of magnetic
fields on a large scale and allow theories to be tested concerning both the
origin of relativistic particles in the ICM and their propagation.
  A deep radio bservation of the A2255 galaxy cluster was carried out at 85 cm
with the WSRT. The good UV-coverage and sensitivity achieved by these
observations allowed us to image the complex structure of the low-brightness,
extended cluster sources (radio halo and relic). These sources show a larger
extent than what has been imaged so far at this frequency, with two new
structures located SW and NW of the cluster center and at projected distances
of 2 Mpc from it. The physical properties of the newly detected structures,
together with the active dynamical state of the cluster, support a connection
with large-scale structure (LSS) formation shocks.


title: alpha-alpha Scattering in Halo Effective Field Theory

abstract:
  We study the two-alpha-particle (alpha-alpha) system in an Effective Field
Theory (EFT) for halo-like systems. We propose a power counting that
incorporates the subtle interplay of strong and electromagnetic forces leading
to a narrow resonance at an energy of about 0.1 MeV. We investigate the EFT
expansion in detail, and compare its results with existing low-energy
alpha-alpha phase shifts and previously determined effective-range parameters.
Good description of the data is obtained with a surprising amount of
fine-tuning. This scenario can be viewed as an expansion around the limit
where, when electromagnetic interactions are turned off, the Be-8 ground state
is at threshold and exhibits conformal invariance. We also discuss possible
extensions to systems with more than two alpha particles.


title: Is it possible to estimate the Higgs Mass from the CMB Power Spectrum?

abstract:
  General Relativity and Standard Model are considered as a theory of dynamical
scale symmetry with definite initial data compatible with the accepted Higgs
mechanism. In this theory the Early Universe behaves like a factory of
electroweak bosons and Higgs scalars, and it gives a possibility to identify
three peaks in the Cosmic Microwave Background power spectrum with the
contributions of photonic decays and annihilation processes of primordial
Higgs, W, and Z bosons in agreement with the QED coupling constant, Weinberg's
angle, and Higgs' particle mass of about 118 GeV.


title:
Gamma-Ray Bursts in $1.8 < z < 5.6$ Suggest that the Time Variation of
  the Dark Energy is Small

abstract:
  We calibrated the peak energy-peak luminosity relation of GRBs (so called
Yonetoku relation) using 33 events with the redshift $z < 1.62$ without
assuming any cosmological models. The luminosity distances to GRBs are
estimated from those of large amount of Type Ia supernovae with $z<1.755$. This
calibrated Yonetoku relation can be used as a new cosmic distance ladder toward
higher redshifts. We determined the luminosity distances of 30 GRBs in $1.8 < z
< 5.6$ using the calibrated relation and plotted the likelihood contour in
$(\Omega_m,\Omega_\Lambda)$ plane. We obtained $(\Omega_m, \Omega_{\Lambda})=
(0.37^{+0.14}_{-0.11}, 0.63^{+0.11}_{-0.14})$ for a flat universe. Since our
method is free from the circularity problem, we can say that our universe in
$1.8 < z < 5.6$ is compatible with the so called concordance cosmological model
derived for $z < 1.8$. This suggests that the time variation of the dark energy
is small or zero up to $z\sim 6$.


title:
Quasi-Large Sparse-Sequence CDMA: Approach to Single-User Bound by
  Linearly-Complex LAS Detectors

abstract:
  We have proposed a quasi-large random-sequence (QLRS) CDMA where K users
access a point through a common channel with spectral spreading factor N. Each
bit is extended by a temporal spreading factor B and hopped on a BN-chip random
sequence that is spread in time and frequency. Each user multiplexes and
transmits B extended bits and the total channel load is alpha = K/N bits/s/Hz.
The linearly-complex LAS detectors detect the transmitted bits. We have
obtained that as B tends to infinity, if alpha < 1/2 - 1/(4ln2), each
transmitted bit achieves the single-bit bound in BER in high SNR regime as if
there was no interference bit. In simulation, when bit number BK >= 500, each
bit can approach the single-bit bound for alpha as high as 1 bit/s/Hz. In this
paper, we further propose the quasi-large sparse-sequence (QLSS) CDMA by
replacing the dense sequence in QLRS-CDMA with sparse sequence. Simulation
results show that when the nonzero chips are as few as 16, the BER is already
near that of QLRS-CDMA while the complexity is significantly reduced due to
sequence sparsity.


title: A Class of Nonbinary Codes and Their Weight Distribution

abstract:
  In this paper, for an even integer $n\geq 4$ and any positive integer $k$
with ${\rm gcd}(n/2,k)={\rm gcd}(n/2-k,2k)=d$ being odd, a class of $p$-ary
codes $\mathcal{C}^k$ is defined and their weight distribution is completely
determined, where $p$ is an odd prime. As an application, a class of nonbinary
sequence families is constructed from these codes, and the correlation
distribution is also determined.


title: Effective Potential of Higgs Field in Warped Gauge-Higgs Unification

abstract:
  The gauge-Higgs unification is one of influential scenarios to solve the
hierarchy problem in the Standard Model. Recently, the scenario on the warped
background attracts many attentions due to a large possibility to construct a
realistic model naturally in this framework. It is, however, well known that
the effective potential for the Higgs field, which is the most important
prediction of the scenario, is not easy to calculate on the warped background,
because masses of Kaluza-Klein particles are not obtained analytically. In this
article, we derive useful formulae for the effective potential. The formulae
allow us to calculate the Higgs mass easily, thus to construct a realistic
model in the gauge-Higgs unification scenario on the warped background. Using
obtained formulae, we calculate contributions from bulk fermions with several
boundary conditions. We also show bulk fermions, which have boundary conditions
not allowed in the orbifold picture, do not contribute to the effective
potential.


title: An operator approach to multipoint Pade approximations

abstract:
  First, an abstract scheme of constructing biorthogonal rational systems
related to some interpolation problems is proposed. We also present a
modification of the famous step-by-step process of solving the Nevanlinna-Pick
problems for Nevanlinna functions. The process in question gives rise to
three-term recurrence relations with coefficients depending on the spectral
parameter. These relations can be rewritten in the matrix form by means of two
Jacobi matrices. As a result, a convergence theorem for multipoint Pad\'e
approximants to Nevanlinna functions is proved.