title: Green functions and nonlinear systems: Short time expansion

abstract:
  We show that Green function methods can be straightforwardly applied to
nonlinear equations appearing as the leading order of a short time expansion.
Higher order corrections can be then computed giving a satisfactory agreement
with numerical results. The relevance of these results relies on the
possibility of fully exploiting a gradient expansion in both classical and
quantum field theory granting the existence of a strong coupling expansion.
Having a Green function in this regime in quantum field theory amounts to
obtain the corresponding spectrum of the theory.


title: One-way permutations, computational asymmetry and distortion

abstract:
  Computational asymmetry, i.e., the discrepancy between the complexity of
transformations and the complexity of their inverses, is at the core of one-way
transformations. We introduce a computational asymmetry function that measures
the amount of one-wayness of permutations. We also introduce the word-length
asymmetry function for groups, which is an algebraic analogue of computational
asymmetry. We relate boolean circuits to words in a Thompson monoid, over a
fixed generating set, in such a way that circuit size is equal to word-length.
Moreover, boolean circuits have a representation in terms of elements of a
Thompson group, in such a way that circuit size is polynomially equivalent to
word-length. We show that circuits built with gates that are not constrained to
have fixed-length inputs and outputs, are at most quadratically more compact
than circuits built from traditional gates (with fixed-length inputs and
outputs). Finally, we show that the computational asymmetry function is closely
related to certain distortion functions: The computational asymmetry function
is polynomially equivalent to the distortion of the path length in Schreier
graphs of certain Thompson groups, compared to the path length in Cayley graphs
of certain Thompson monoids. We also show that the results of Razborov and
others on monotone circuit complexity lead to exponential lower bounds on
certain distortions.


title:
A method for the direct determination of the surface gravities of
  transiting extrasolar planets

abstract:
  We show that the surface gravity of a transiting extrasolar planet can be
calculated from only the spectroscopic orbit of its parent star and the
analysis of its transit light curve. This does not require additional
constraints, such as are often inferred from theoretical stellar models or
model atmospheres. The planet's surface gravity can therefore be measured
precisely and from only directly observable quantities. We outline the method
and apply it to the case of the first known transiting extrasolar planet, HD
209458b. We find a surface gravity of g_p = 9.28 +/- 0.15 m/s, which is an
order of magnitude more precise than the best available measurements of its
mass, radius and density. This confirms that the planet has a much lower
surface gravity that that predicted by published theoretical models of gas
giant planets. We apply our method to all fourteen known transiting extrasolar
planets and find a significant correlation between surface gravity and orbital
period, which is related to the known correlation between mass and period. This
correlation may be the underlying effect as surface gravity is a fundamental
parameter in the evaporation of planetary atmospheres.


title: On restrictions of balanced 2-interval graphs

abstract:
  The class of 2-interval graphs has been introduced for modelling scheduling
and allocation problems, and more recently for specific bioinformatic problems.
Some of those applications imply restrictions on the 2-interval graphs, and
justify the introduction of a hierarchy of subclasses of 2-interval graphs that
generalize line graphs: balanced 2-interval graphs, unit 2-interval graphs, and
(x,x)-interval graphs. We provide instances that show that all the inclusions
are strict. We extend the NP-completeness proof of recognizing 2-interval
graphs to the recognition of balanced 2-interval graphs. Finally we give hints
on the complexity of unit 2-interval graphs recognition, by studying
relationships with other graph classes: proper circular-arc, quasi-line graphs,
K_{1,5}-free graphs, ...


title: Exchange parameters from approximate self-interaction correction scheme

abstract:
  The approximate atomic self-interaction corrections (ASIC) method to density
functional theory is put to the test by calculating the exchange interaction
for a number of prototypical materials, critical to local exchange and
correlation functionals. ASIC total energy calculations are mapped onto an
Heisenberg pair-wise interaction and the exchange constants J are compared to
those obtained with other methods. In general the ASIC scheme drastically
improves the bandstructure, which for almost all the cases investigated
resemble closely available photo-emission data. In contrast the results for the
exchange parameters are less satisfactory. Although ASIC performs reasonably
well for systems where the magnetism originates from half-filled bands, it
suffers from similar problems than those of LDA for other situations. In
particular the exchange constants are still overestimated. This reflects a
subtle interplay between exchange and correlation energy, not captured by the
ASIC.


title:
Generalized sqrt(epsilon)-law. The role of unphysical source terms in
  resonance line polarization transfer and its importance as an additional test
  of NLTE radiative transfer codes

abstract:
  Context. A derivation of a generalized sqrt(epsilon)-law for nonthermal
collisional rates of excitation by charged perturbers is presented. Aims. Aim
of this paper is to find a more general analytical expression for a surface
value of the source function which can be used as an addtional tool for
verification of the non-LTE radiative transfer codes. Methods. Under the impact
approximation hypothesis, static, one-dimensional, plane-parallel atmosphere,
constant magnetic field of arbitrary strength and direction, two-level atom
model with unpolarized lower level and stimulated emission neglected, we
introduce the unphysical terms into the equations of statistical equilibrium
and solve the appropriate non-LTE integral equations. Results. We derive a new
analytical condition for the surface values of the source function components
expressed in the basis of irreducible spherical tensors.


title:
Retarded electric and magnetic fields of a moving charge: Feynman's
  derivation of Li\'enard-Wiechert potentials revisited

abstract:
  Retarded electromagnetic potentials are derived from Maxwell's equations and
the Lorenz condition. The difference found between these potentials and the
conventional Li\'{e}nard-Wiechert ones is explained by neglect, for the latter,
of the motion-dependence of the effective charge density. The corresponding
retarded fields of a point-like charge in arbitary motion are compared with
those given by the formulae of Heaviside, Feynman, Jefimenko and other authors.
The fields of an accelerated charge given by the Feynman are the same as those
derived from the Li\'{e}nard-Wiechert potentials but not those given by the
Jefimenko formulae. A mathematical error concerning partial space and time
derivatives in the derivation of the Jefimenko equations is pointed out.


title:
On the characterization of isotropic Gaussian fields on homogeneous
  spaces of compact groups

abstract:
  Let T be a random field invariant under the action of a compact group G We
give conditions ensuring that independence of the random Fourier coefficients
is equivalent to Gaussianity. As a consequence, in general it is not possible
to simulate a non-Gaussian invariant random field through its Fourier expansion
using independent coefficients.


title: A Catalog of Star Cluster Candidates in M33

abstract:
  We present a new catalog of star cluster candidates in the nearby spiral
galaxy M33. It is based on eight existing catalogs wherein we have
cross-referenced identifications and endeavored to resolve inconsistencies
between them. Our catalog contains 451 candidates of which 255 are confirmed
clusters based on HST and high resolution ground-based imaging. The catalog
contains precise cluster positions (RA and Dec), magnitudes and colors in the
UBVRIJHKs filters, metallicities, radial velocities, masses and ages, where
available, and galactocentric distances for each cluster. The color
distribution of the M33 clusters appears to be similar to those in the Large
Magellanic Cloud with major peaks at (B-V)o~0.15, and (B-V)o~0.65. The
intrinsic colors are correlated with cluster ages, which range from 10^{7.5} to
10^{10.3} years. The age distribution of the star clusters supports the notion
of rapid cluster disruption with a slope of alpha=-1.09 +/- 0.07 in the
dN_{cluster}/dt ~ t^{alpha} relation. In addition, comparison to theoretical
single stellar population models suggests the presence of an age-metallicity
relation among these clusters with younger clusters being more metal-rich.
Analysis of the radial distribution of the clusters yields some evidence that
younger clusters (age <~ 1 Gyr) may be more concentrated toward the center of
M33 than older ones. A similar comparison with the radial profile of the M33
field stars shows the clusters to be more centrally concentrated at the greater
than 99.9% confidence level. Possible reasons for this are presented and
discussed; however, the overwhelming conclusion seems to be that a more
complete and thorough cluster search is needed covering at least 4 square
degrees centered on M33.


title:
Sharp dark-mode resonances in planar metamaterials with broken
  structural symmetry

abstract:
  We report that resonant response with a very high quality factor can be
achieved in a planar metamaterial by introducing symmetry breaking in the shape
of its structural elements, which enables excitation of dark modes, i.e. modes
that are weakly coupled to free space.


title: Proper motion L and T dwarf candidate members of the Pleiades

abstract:
  We present the results of a deep optical-near-infrared multi-epoch survey
covering 2.5 square degrees of the Pleiades open star cluster to search for new
very-low-mass brown dwarf members. A significant (~ 5 year) epoch difference
exists between the optical (CFH12k I-, Z-band) and near infrared (UKIRT WFCAM
J-band) observations. We construct I,I-Z and Z,Z-J colour magnitude diagrams to
select candidate cluster members. Proper motions are computed for all candidate
members and compared to the background field objects to further refine the
sample. We recover all known cluster members within the area of our survey. In
addition, we have discovered 9 new candidate brown dwarf cluster members. The 7
faintest candidates have red Z-J colours and show blue near-infrared colours.
These are consistent with being L and T-type Pleiads. Theoretical models
predict their masses to be around 11 Jupiter masses.
  There is 1 errata for this paper


title:
A Study of Catalogued Nearby Galaxy Clusters in the SDSS-DR4: I. Cluster
  Global Properties

abstract:
  We have selected a sample of 88 nearby (z<0.1) galaxy clusters from the
SDSS-DR4 with redshift information for the cluster members. We have derived
global properties for each cluster, such as their mean recessional velocity,
velocity dispersion, and virial radii. Cluster galaxies have been grouped in
two families according to their $u-r$ colours. The total sample consists of
10865 galaxies. As expected, the highest fraction of galaxies (62%) turned to
be early-type (red) ones, being located at smaller distances from the cluster
centre and showing lower velocity dispersions than late-type (blue) ones. The
brightest cluster galaxies are located in the innermost regions and show the
smallest velocity dispersions. Early-type galaxies also show constant velocity
dispersion profiles inside the virial radius and a mild decline in the
outermost regions. In contrast, late-type galaxies show always decreasing
velocity dispersions profiles. No correlation has been found between the
fraction of blue galaxies and cluster global properties, such as cluster
velocity dispersion and galaxy concentration. In contrast, we found correlation
between the X-ray luminosity and the fraction of blue galaxies. These results
indicate that early- and late-type galaxies may have had different evolution.
Thus, blue galaxies are located in more anisotropic and radial orbits than
early-type ones. Their star formation seems to be independent of the cluster
global properties in low mass clusters, but not for the most massive ones.
These observational results suggest that the global environment could be
important for driving the evolution of galaxies in the most massive cluster
($\sigma > 800$ km s$^{-1}$). However, the local environment could play a key
role in galaxy evolution for low mass clusters.


title:
Optical implementation and entanglement distribution in Gaussian valence
  bond states

abstract:
  We study Gaussian valence bond states of continuous variable systems,
obtained as the outputs of projection operations from an ancillary space of M
infinitely entangled bonds connecting neighboring sites, applied at each of $N$
sites of an harmonic chain. The entanglement distribution in Gaussian valence
bond states can be controlled by varying the input amount of entanglement
engineered in a (2M+1)-mode Gaussian state known as the building block, which
is isomorphic to the projector applied at a given site. We show how this
mechanism can be interpreted in terms of multiple entanglement swapping from
the chain of ancillary bonds, through the building blocks. We provide optical
schemes to produce bisymmetric three-mode Gaussian building blocks (which
correspond to a single bond, M=1), and study the entanglement structure in the
output Gaussian valence bond states. The usefulness of such states for quantum
communication protocols with continuous variables, like telecloning and
teleportation networks, is finally discussed.


title: Rich magnetic phase diagram in the Kagome-staircase compound Mn3V2O8

abstract:
  Mn3V2O8 is a magnetic system in which S = 5/2 Mn2+ is found in the kagome
staircase lattice. Here we report the magnetic phase diagram for temperatures
above 2 K and applied magnetic fields below 9 T, characterized by measurements
of the magnetization and specific heat with field along the three unique
lattice directions. At low applied magnetic fields, the system first orders
magnetically below Tm1 ~ 21 K, and then shows a second magnetic phase
transition at Tm2 ~ 15 K. In addition, a phase transition that is apparent in
specific heat but not seen in magnetization is found for all three applied
field orientations, converging towards Tm2 as H -> 0. The magnetic behavior is
highly anisotropic, with critical fields for magnetic phase boundaries much
higher when the field is applied perpendicular to the Kagome staircase plane
than when applied in-plane. The field-temperature (H - T) phase diagrams are
quite rich, with 7 distinct phases observed.


title: L^2-Betti numbers of coamenable quantum groups

abstract:
  We prove that a compact quantum group is coamenable if and only if its
corepresentation ring is amenable. We further propose a Foelner condition for
compact quantum groups and prove it to be equivalent to coamenability. Using
this Foelner condition, we prove that for a coamenable compact quantum group
with tracial Haar state, the enveloping von Neumann algebra is dimension flat
over the Hopf algebra of matrix coefficients. This generalizes a theorem of
Lueck from the group case to the quantum group case, and provides examples of
compact quantum groups with vanishing L^2-Betti numbers.


title:
OPserver: interactive online-computations of opacities and radiative
  accelerations

abstract:
  Codes to compute mean opacities and radiative accelerations for arbitrary
chemical mixtures using the Opacity Project recently revised data have been
restructured in a client--server architecture and transcribed as a subroutine
library. This implementation increases efficiency in stellar modelling where
element stratification due to diffusion processes is depth dependent, and thus
requires repeated fast opacity reestimates. Three user modes are provided to
fit different computing environments, namely a web browser, a local workstation
and a distributed grid.


title:
Can One Estimate The Unconditional Distribution of Post-Model-Selection
  Estimators?

abstract:
  We consider the problem of estimating the unconditional distribution of a
post-model-selection estimator. The notion of a post-model-selection estimator
here refers to the combined procedure resulting from first selecting a model
(e.g., by a model selection criterion like AIC or by a hypothesis testing
procedure) and then estimating the parameters in the selected model (e.g., by
least-squares or maximum likelihood), all based on the same data set. We show
that it is impossible to estimate the unconditional distribution with
reasonable accuracy even asymptotically. In particular, we show that no
estimator for this distribution can be uniformly consistent (not even locally).
This follows as a corollary to (local) minimax lower bounds on the performance
of estimators for the distribution; performance is here measured by the
probability that the estimation error exceeds a given threshold. These lower
bounds are shown to approach 1/2 or even 1 in large samples, depending on the
situation considered. Similar impossibility results are also obtained for the
distribution of linear functions (e.g., predictors) of the post-model-selection
estimator.


title: Fixed Phase Quantum Search Algorithm

abstract:
  Building quantum devices using fixed operators is a must to simplify the
hardware construction. Quantum search engine is not an exception. In this
paper, a fixed phase quantum search algorithm that searches for M matches in an
unstructured search space of size N will be presented. Selecting phase shifts
of 1.91684\pi in the standard amplitude amplification will make the technique
perform better so as to get probability of success at least 99.58% in
O(sqrt(N/M)) better than any know fixed operator quantum search algorithms. The
algorithm will be able to handle either a single match or multiple matches in
the search space. The algorithm will find a match in O(sqrt(N/M)) whether the
number of matches is known or not in advance.


title:
Core excitation in the elastic scattering and breakup of $^{11}$Be on
  protons

abstract:
  The elastic scattering and breakup of $^{11}$Be from a proton target at
intermediate energies is studied. We explore the role of core excitation in the
reaction mechanism. Comparison with the data suggests that there is still
missing physics in the description.


title: Possible X-ray diagnostic for jet/disk dominance in Type 1 AGN

abstract:
  Using Rossi X-ray Timing Explorer Seyfert 1 and 1.2 data spanning 9 years, we
study correlations between X-ray spectral features. The sample consists of 350
time-resolved spectra from 12 Seyfert 1 and 1.2 galaxies. Each spectrum is
fitted to a model with an intrinsic powerlaw X-ray spectrum produced close to
the central black hole that is reprocessed and absorbed by material around the
black hole. To test the robustness of our results, we performed Monte Carlo
simulations of the spectral sample. We find a complex relationship between the
iron line equivalent width (EW) and the underlying power law index (Gamma). The
data reveal a correlation between Gamma and EW which turns over at Gamma <~ 2,
but finds a weak anti-correlation for steeper photon indices. We propose that
this relationship is driven by dilution of a disk spectrum (which includes the
narrow iron line) by a beamed jet component and, hence, could be used as a
diagnostic of jet-dominance. In addition, our sample shows a strong correlation
between the reflection fraction (R) and Gamma, but we find that it is likely
the result of modeling degeneracies. We also see the X-ray Baldwin effect (an
anti-correlation between the 2-10 keV X-ray luminosity and EW) for the sample
as a whole, but not for the individual galaxies and galaxy types.


title: On algebraic automorphisms and their rational invariants

abstract:
  Let X be an affine irreducible variety over an algebraically closed field k
of characteristic zero. Given an automorphism F, we denote by k(X)^F its field
of invariants, i.e. the set of rational functions f on X such that f(F)=f. Let
n(F) be the transcendence degree of k(X)^F over k. In this paper, we study the
class of automorphisms F of X for which n(F)= dim X - 1. More precisely, we
show that under some conditions on X, every such automorphism is of the form
F=A_g, where A is an algebraic action of a linear algebraic group G of
dimension 1 on X, and where g belongs to G. As an application, we determine the
conjugacy classes of automorphisms of the plane for which n(F)=1.


title: Improving immunization strategies

abstract:
  We introduce an immunization method where the percentage of required
vaccinations for immunity are close to the optimal value of a targeted
immunization scheme of highest degree nodes. Our strategy retains the advantage
of being purely local, without the need of knowledge on the global network
structure or identification of the highest degree nodes. The method consists of
selecting a random node and asking for a neighbor that has more links than
himself or more than a given threshold and immunizing him. We compare this
method to other efficient strategies on three real social networks and on a
scale-free network model, and find it to be significantly more effective.


title: Constraints on the Very Early Universe from Thermal WIMP Dark Matter

abstract:
  We investigate the relic density n_\chi of non-relativistic long-lived or
stable particles \chi in non-standard cosmological scenarios. We calculate the
relic abundance starting from arbitrary initial temperatures of the
radiation-dominated epoch, and derive the lower bound on the initial
temperature T_0 \geq m_\chi/23, assuming that thermally produced \chi particles
account for the dark matter energy density in the universe; this bound holds
for all \chi annihilation cross sections. We also investigate cosmological
scenarios with modified expansion rate. Even in this case an approximate
formula similar to the standard one is capable of predicting the final relic
abundance correctly. Choosing the \chi annihilation cross section such that the
observed cold dark matter abundance is reproduced in standard cosmology, we
constrain possible modifications of the expansion rate at T \sim m_\chi/20,
well before Big Bang nucleosynthesis.


title: Flavour-Dependent Type II Leptogenesis

abstract:
  We reanalyse leptogenesis via the out-of-equilibrium decay of the lightest
right-handed neutrino in type II seesaw scenarios, taking into account
flavour-dependent effects. In the type II seesaw mechanism, in addition to the
type I seesaw contribution, an additional direct mass term for the light
neutrinos is present. We consider type II seesaw scenarios where this
additional contribution arises from the vacuum expectation value of a Higgs
triplet, and furthermore an effective model-independent approach. We
investigate bounds on the flavour-specific decay asymmetries, on the mass of
the lightest right-handed neutrino and on the reheat temperature of the early
universe, and compare them to the corresponding bounds in the type I seesaw
framework. We show that while flavour-dependent thermal type II leptogenesis
becomes more efficient for larger mass scale of the light neutrinos, and the
bounds become relaxed, the type I seesaw scenario for leptogenesis becomes more
constrained. We also argue that in general, flavour-dependent effects cannot be
ignored when dealing with leptogenesis in type II seesaw models.


title: Multi-wavelength Analysis of a Quiet Solar Region

abstract:
  We present observations of a solar quiet region obtained by the ground-based
Dutch Open Telescope (DOT), and by instruments on the spacecraft SOHO and
TRACE. The observations were obtained during a coordinated observing campaign
on October 2005. The aim of this work is to present the rich diversity of
fine-scale structures that are found at the network boundaries and their
appearance in different instruments and different spectral lines that span the
photosphere to the corona. Detailed studies of these structures are crucial to
understanding their dynamics in different solar layers, as well as the role
such structures play in the mass balance and heating of the solar atmosphere.


title:
Orbital currents in the Colle-Salvetti correlation energy functional and
  the degeneracy problem

abstract:
  Popular density functionals for the exchange-correlation energy typically
fail to reproduce the degeneracy of different ground states of open-shell
atoms. As a remedy, functionals which explicitly depend on the current density
have been suggested. We present an analysis of this problem by investigating
functionals that explicitly depend on the Kohn-Sham orbitals. Going beyond the
exact-exchange approximation by adding correlation in the form of the
Colle-Salvetti functional we show how current-dependent terms enter the
Colle-Salvetti expression and their relevance is evaluated. A very good
description of the degeneracy of ground-states for atoms of the first and
second row of the periodic table is obtained.


title: Cooper pairs in atomic nuclei

abstract:
  We consider the development of Cooper pairs in a self-consistent Hartree Fock
mean field for the even Sm isotopes. Results are presented at the level of a
BCS treatment, a number-projected BCS treatment and an exact treatment using
the Richardson ansatz. While projected BCS captures much of the pairing
correlation energy that is absent from BCS, it still misses a sizable
correlation energy, typically of order $1 MeV$. Furthermore, because it does
not average over the properties of the fermion pairs, the exact Richardson
solution permits a more meaningful definition of the Cooper wave function and
of the fraction of pairs that are collective.


title:
An adaptive numerical method for the Vlasov equation based on a
  multiresolution analysis

abstract:
  In this paper, we present very first results for the adaptive solution on a
grid of the phase space of the Vlasov equation arising in particles accelarator
and plasma physics. The numerical algorithm is based on a semi-Lagrangian
method while adaptivity is obtained using multiresolution analysis.


title: Turbulence and the Navier-Stokes equations

abstract:
  The concept of continuous topological evolution, based upon Cartan's methods
of exterior differential systems, is used to develop a topological theory of
non-equilibrium thermodynamics, within which there exist processes that exhibit
continuous topological change and thermodynamic irreversibility. The technique
furnishes a universal, topological foundation for the partial differential
equations of hydrodynamics and electrodynamics; the technique does not depend
upon a metric, connection or a variational principle. Certain topological
classes of solutions to the Navier-Stokes equations are shown to be equivalent
to thermodynamically irreversible processes.


title: Numerical estimation of critical parameters using the Bond entropy

abstract:
  Using a model of spinless fermions in a lattice with nearest neighbor and
next-nearest neighbor interaction we show that the entropy of the reduced two
site density matrix (the bond entropy) can be used as an extremely accurate and
easy to calculate numerical indicator for the critical parameters of the
quantum phase transition when the basic ordering pattern has a two-site
periodicity. The actual behavior of the bond entropy depends on the particular
characteristics of the transition under study. For the Kosterlitz-Thouless type
phase transition from a Luttinger liquid phase to a charge density wave state
the bond entropy has a local maximum while in the transition from the Luttinger
liquid to the phase separated state the derivative of the bond entropy has a
divergence due to the cancelation of the third eigenvalue of the two-site
reduced density matrix.


title:
Radiative transitions of the helium atom in highly magnetized neutron
  star atmospheres

abstract:
  Recent observations of thermally emitting isolated neutron stars revealed
spectral features that could be interpreted as radiative transitions of He in a
magnetized neutron star atmosphere. We present Hartree-Fock calculations of the
polarization-dependent photoionization cross sections of the He atom in strong
magnetic fields ranging from 10^12 G to 10^14 G. Convenient fitting formulae
for the cross sections are given as well as related oscillator strengths for
various bound-bound transitions. The effects of finite nucleus mass on the
radiative absorption cross sections are examined using perturbation theory.


title: Critical points for surface maps and the Benedicks-Carleson theorem

abstract:
  We give an alternative proof of the Benedicks-Carleson theorem on the
existence of strange attractors in H\'enon-like families in the plane. To
bypass a huge inductive argument, we introduce an induction-free explicit
definition of dynamically critical points. The argument is sufficiently general
and in particular applies to the case of non-invertible maps as well. It
naturally raises the question of an intrinsic characterization of dynamically
critical points for dissipative surface maps.


title:
The VIMOS VLT Deep Survey. The Assembly History of the Stellar Mass in
  Galaxies: from the Young to the Old Universe

abstract:
  We present a detailed analysis of the Galaxy Stellar Mass Function of
galaxies up to z=2.5 as obtained from the VVDS. We estimate the stellar mass
from broad-band photometry using 2 different assumptions on the galaxy star
formation history and show that the addition of secondary bursts to a
continuous star formation history produces systematically higher (up to 40%)
stellar masses. At low redshift (z=0.2) we find a substantial population of
low-mass galaxies (<10^9 Msun) composed by faint blue galaxies (M_I-M_K=0.3).
In general the stellar mass function evolves slowly up to z=0.9 and more
significantly above this redshift. Conversely, a massive tail is present up to
z=2.5 and have extremely red colours (M_I-M_K=0.7-0.8). We find a decline with
redshift of the overall number density of galaxies for all masses (59+-5% for
M>10^8 Msun at z=1), and a mild mass-dependent average evolution
(`mass-downsizing'). In particular our data are consistent with mild/negligible
(<30%) evolution up to z=0.7 for massive galaxies (>6x10^10 Msun). For less
massive systems the no-evolution scenario is excluded. A large fraction (>=50%)
of massive galaxies have been already assembled and converted most of their gas
into stars at z=1, ruling out the `dry mergers' as the major mechanism of their
assembly history below z=1. This fraction decreases to 33% at z=2. Low-mass
systems have decreased continuously in number and mass density (by a factor up
to 4) from the present age to z=2, consistently with a prolonged mass assembly
also at z<1.


title:
Spontaneous symmetry breaking of solitons trapped in a double-channel
  potential

abstract:
  We consider a two-dimensional (2D) nonlinear Schrodinger equation with
self-focusing nonlinearity and a quasi-1D double-channel potential, i.e., a
straightforward 2D extension of the well-known double-well potential. The model
may be realized in terms of nonlinear optics and Bose-Einstein condensates. The
variational approximation (VA) predicts a bifurcation breaking the symmetry of
2D solitons trapped in the double channel, the bifurcation being of the
subcritical type. The predictions of the VA are confirmed by numerical
simulations. The work presents the first example of the spontaneous symmetry
breaking (SSB) of 2D solitons in any dual-core system.


title:
What does Hirsch index evolution explain us? A case study: Turkish
  Journal of Chemistry

abstract:
  The evolution of Turkish Journal of Chemistry (Turk J. Chem) Hirsch index
(h-index) over the period 1995-2005 is studied and determined in the case of
the self and without self-citations. It is seen that the effect of Hirsch index
of Turk J. Chem has a highly positive trend during the last five years. It
proves that Turk J. Chem is improving itself both in quantity and quality since
h-index reflects peer review, and peer review reflects research quality of a
journal.


title:
Measuring energy dependent polarization in soft gamma-rays using Compton
  scattering in PoGOLite

abstract:
  Linear polarization in X- and gamma-rays is an important diagnostic of many
astrophysical sources, foremost giving information about their geometry,
magnetic fields, and radiation mechanisms. However, very few X-ray polarization
measurements have been made, and then only mono-energetic detections, whilst
several objects are assumed to have energy dependent polarization signatures.
In this paper we investigate whether detection of energy dependent polarization
from cosmic sources is possible using the Compton technique, in particular with
the proposed PoGOLite balloon-experiment, in the 25-100 keV range. We use
Geant4 simulations of a PoGOLite model and input photon spectra based on Cygnus
X-1 and accreting magnetic pulsars (100 mCrab). Effective observing times of 6
and 35 hours were simulated, corresponding to a standard and a long duration
flight respectively. Both smooth and sharp energy variations of the
polarization are investigated and compared to constant polarization signals
using chi-square statistics. We can reject constant polarization, with energy,
for the Cygnus X-1 spectrum (in the hard state), if the reflected component is
assumed to be completely polarized, whereas the distinction cannot be made for
weaker polarization. For the accreting pulsar, constant polarization can be
rejected in the case of polarization in a narrow energy band with at least 50%
polarization, and similarly for a negative step distribution from 30% to 0%
polarization.


title:
Baryon Number-Induced Chern-Simons Couplings of Vector and Axial-Vector
  Mesons in Holographic QCD

abstract:
  We show that holographic models of QCD predict the presence of a Chern-Simons
coupling between vector and axial-vector mesons at finite baryon density. In
the AdS/CFT dictionary, the coefficient of this coupling is proportional to the
baryon number density, and is fixed uniquely in the five-dimensional
holographic dual by anomalies in the flavor currents. For the lightest mesons,
the coupling mixes transverse $\rho$ and $a_1$ polarization states. At
sufficiently large baryon number densities, it produces an instability, which
causes the $\rho$ and $a_1$ mesons to condense in a state breaking both
rotational and translational invariance.


title: Total Quantum Zeno Effect beyond Zeno Time

abstract:
  In this work we show that is possible to obtain Total Quantum Zeno Effect in
an unstable systems for times larger than the correlation time of the bath. The
effect is observed for some particular systems in which one can chose
appropriate observables which frequent measurements freeze the system into the
initial state. For a two level system in a squeezed bath one can show that
there are two bath dependent observables displaying Total Zeno Effect when the
system is initialized in some particular states. We show also that these states
are intelligent states of two conjugate observables associated to the
electromagnetic fluctuations of the bath.


title: Asteroseismic Signatures of Stellar Magnetic Activity Cycles

abstract:
  Observations of stellar activity cycles provide an opportunity to study
magnetic dynamos under many different physical conditions. Space-based
asteroseismology missions will soon yield useful constraints on the interior
conditions that nurture such magnetic cycles, and will be sensitive enough to
detect shifts in the oscillation frequencies due to the magnetic variations. We
derive a method for predicting these shifts from changes in the Mg II activity
index by scaling from solar data. We demonstrate this technique on the
solar-type subgiant beta Hyi, using archival International Ultraviolet Explorer
spectra and two epochs of ground-based asteroseismic observations. We find
qualitative evidence of the expected frequency shifts and predict the optimal
timing for future asteroseismic observations of this star.


title: Anomalous energy transport in the FPU-beta chain

abstract:
  We consider the energy current correlation function for the FPU-beta lattice.
For small non-linearity one can rely on kinetic theory. The issue reduces then
to a spectral analysis of the linearized collision operator. We prove thereby
that, on the basis of kinetic theory, the energy current correlations decay in
time as t^(-3/5). It follows that the thermal conductivity is anomalous,
increasing as N^(2/5) with the system size N.


title: Diffractive parton distributions from the analysis with higher twist

abstract:
  Diffractive parton distributions of the proton are determined from fits to
diffractive data from HERA. In addition to the twist--2 contribution, the
twist--4 contribution from longitudinally polarised virtual photons is
considered, which is important in the region of small diffractive masses. A new
prediction for the longitudinal diffractive structure function is presented
which differs significantly from that obtained in the pure twist--2 analyses.


title:
GRB 061121: Broadband spectral evolution through the prompt and
  afterglow phases of a bright burst

abstract:
  Swift triggered on a precursor to the main burst of GRB 061121 (z=1.314),
allowing observations to be made from the optical to gamma-ray bands. Many
other telescopes, including Konus-Wind, XMM-Newton, ROTSE and the Faulkes
Telescope North, also observed the burst. The gamma-ray, X-ray and UV/optical
emission all showed a peak ~75s after the trigger, although the optical and
X-ray afterglow components also appear early on - before, or during, the main
peak. Spectral evolution was seen throughout the burst, with the prompt
emission showing a clear positive correlation between brightness and hardness.
The Spectral Energy Distribution (SED) of the prompt emission, stretching from
1eV up to 1MeV, is very flat, with a peak in the flux density at ~1keV. The
optical-to-X-ray spectra at this time are better fitted by a broken, rather
than single, power-law, similar to previous results for X-ray flares. The SED
shows spectral hardening as the afterglow evolves with time. This behaviour
might be a symptom of self-Comptonisation, although circumstellar densities
similar to those found in the cores of molecular clouds would be required. The
afterglow also decays too slowly to be accounted for by the standard models.
Although the precursor and main emission show different spectral lags, both are
consistent with the lag-luminosity correlation for long bursts. GRB 061121 is
the instantaneously brightest long burst yet detected by Swift. Using a
combination of Swift and Konus-Wind data, we estimate an isotropic energy of
2.8x10^53 erg over 1keV - 10MeV in the GRB rest frame. A probable jet break is
detected at ~2x10^5s, leading to an estimate of ~10^51 erg for the
beaming-corrected gamma-ray energy.


title:
High-altitude signatures of ionospheric density depletions caused by
  field-aligned currents

abstract:
  We present Cluster measurements of large electric fields correlated with
intense downward field-aligned currents, and show that the data can be
reproduced by a simple model of ionospheric plasma depletion caused by the
currents. This type of magnetosphere-ionosphere interaction may be important
when considering the mapping between these two regions of space.


title: Burgers Turbulence

abstract:
  The last decades witnessed a renewal of interest in the Burgers equation.
Much activities focused on extensions of the original one-dimensional
pressureless model introduced in the thirties by the Dutch scientist J.M.
Burgers, and more precisely on the problem of Burgers turbulence, that is the
study of the solutions to the one- or multi-dimensional Burgers equation with
random initial conditions or random forcing. Such work was frequently motivated
by new emerging applications of Burgers model to statistical physics,
cosmology, and fluid dynamics. Also Burgers turbulence appeared as one of the
simplest instances of a nonlinear system out of equilibrium. The study of
random Lagrangian systems, of stochastic partial differential equations and
their invariant measures, the theory of dynamical systems, the applications of
field theory to the understanding of dissipative anomalies and of multiscaling
in hydrodynamic turbulence have benefited significantly from progress in
Burgers turbulence. The aim of this review is to give a unified view of
selected work stemming from these rather diverse disciplines.


title:
Analytical evaluation of the X-ray scattering contribution to imaging
  degradation in grazing-incidence X-ray telescopes

abstract:
  The focusing performance of X-ray optics (conveniently expressed in terms of
HEW, Half Energy Width) strongly depend on both mirrors deformations and photon
scattering caused by the microroughness of reflecting surfaces. In particular,
the contribution of X-ray Scattering (XRS) to the HEW of the optic is usually
an increasing function H(E) of the photon energy E. Therefore, in future hard
X-ray imaging telescopes of the future (SIMBOL-X, NeXT, Constellation-X, XEUS),
the X-ray scattering could be the dominant problem since they will operate also
in the hard X-ray band (i.e. beyond 10 keV). [...]
  Several methods were proposed in the past years to estimate the scattering
contribution to the HEW, dealing with the surface microroughness expressed in
terms of its Power Spectral Density (PSD), on the basis of the well-established
theory of X-ray scattering from rough surfaces. We faced that problem on the
basis on the same theory, but we tried a new approach: the direct, analytical
translation of a given surface roughness PSD into a H(E) trend, and - vice
versa - the direct translation of a H(E) requirement into a surface PSD. This
PSD represents the maximum tolerable microroughness level in order to meet the
H(E) requirement in the energy band of a given X-ray telescope.
  We have thereby found a new, analytical and widely applicable formalism to
compute the XRS contribution to the HEW from the surface PSD, provided that the
PSD had been measured in a wide range of spatial frequencies. The inverse
problem was also solved, allowing the immediate evaluation of the mirror
surface PSD from a measured function H(E). The same formalism allows
establishing the maximum allowed PSD of the mirror in order to fulfill a given
H(E) requirement. [...]


title:
Reply to ``Comment on `On the inconsistency of the Bohm-Gadella theory
  with quantum mechanics'''

abstract:
  In this reply, we show that when we apply standard distribution theory to the
Lippmann-Schwinger equation, the resulting spaces of test functions would
comply with the Hardy axiom only if classic results of Paley and Wiener, of
Gelfand and Shilov, and of the theory of ultradistributions were wrong. As
well, we point out several differences between the ``standard method'' of
constructing rigged Hilbert spaces in quantum mechanics and the method used in
Time Asymmetric Quantum Theory.


title: Modelling the Galactic bar using OGLE-II Red Clump Giant Stars

abstract:
  Red clump giant stars can be used as distance indicators to trace the mass
distribution of the Galactic bar. We use RCG stars from 44 bulge fields from
the OGLE-II microlensing collaboration database to constrain analytic tri-axial
models for the Galactic bar. We find the bar major axis is oriented at an angle
of 24 - 27 degrees to the Sun-Galactic centre line-of-sight. The ratio of
semi-major and semi-minor bar axis scale lengths in the Galactic plane x_0,
y_0, and vertical bar scale length z_0, is x_0 : y_0 : z_0 = 10 : 3.5 : 2.6,
suggesting a slightly more prolate bar structure than the working model of
Gerhard (2002) which gives the scale length ratios as x_0 : y_0 : z_0 = 10 : 4
: 3 .


title:
Dynamical Coupled-Channel Model of $\pi N$ Scattering in the W $\leq$ 2
  GeV Nucleon Resonance Region

abstract:
  As a first step to analyze the electromagnetic meson production reactions in
the nucleon resonance region, the parameters of the hadronic interactions of a
dynamical coupled-channel model, developed in {\it Physics Reports 439, 193
(2007)}, are determined by fitting the $\pi N$ scattering data. The channels
included in the calculations are $\pi N$, $\eta N$ and $\pi\pi N$ which has
$\pi\Delta$, $\rho N$, and $\sigma N$ resonant components. The non-resonant
meson-baryon interactions of the model are derived from a set of Lagrangians by
using a unitary transformation method. One or two bare excited nucleon states
in each of $S$, $P$, $D$, and $F$ partial waves are included to generate the
resonant amplitudes in the fits. The parameters of the model are first
determined by fitting as much as possible the empirical $\pi N$ elastic
scattering amplitudes of SAID up to 2 GeV. We then refine and confirm the
resulting parameters by directly comparing the predicted differential cross
section and target polarization asymmetry with the original data of the elastic
$\pi^{\pm} p \to \pi^{\pm} p$ and charge-exchange $\pi^- p \to \pi^0 n$
processes. The predicted total cross sections of $\pi N$ reactions and $\pi
N\to \eta N$ reactions are also in good agreement with the data. Applications
of the constructed model in analyzing the electromagnetic meson production data
as well as the future developments are discussed.


title: Reply to Comment on "Chiral suppression of scalar glueball decay"

abstract: Reply to the comment of Chao, He, and Ma.


title: High-resolution study of a star-forming cluster in the Cep-A HW2 region

abstract:
  Due to its relatively small distance (725 pc), the Cepheus A East
star-forming region is an ideal laboratory to study massive star formation
processes. Based on its morphology, it has been suggested that the flattened
molecular gas distribution around the YSO HW2 may be a 350-AU-radius massive
protostellar disk. Goal of our work is to ascertain the nature of this
structure. We have employed the Plateau de Bure Interferometer to acquire
(sub-)arcsecond-resolution imaging of high-density and shock tracers, such as
methyl cyanide (CH3CN) and silicon monoxide (SiO), towards the HW2 position. On
the 1-arcsecond (about 725 AU) scale, the flattened distribution of molecular
gas around HW2 appears to be due to the projected superposition, on the plane
of the sky, of at least three protostellar objects, of which at least one is
powering a molecular outflow at a small angle with respect to the line of
sight. The presence of a protostellar disk around HW2 is not ruled out, but
such structure is likely to be detected on a smaller spatial scale, or using
different molecular tracers.


title:
A Renormalization group approach for highly anisotropic 2D Fermion
  systems: application to coupled Hubbard chains

abstract:
  I apply a two-step density-matrix renormalization group method to the
anisotropic two-dimensional Hubbard model. As a prelude to this study, I
compare the numerical results to the exact one for the tight-binding model. I
find a ground-state energy which agrees with the exact value up to four digits
for systems as large as $24 \times 25$. I then apply the method to the
interacting case. I find that for strong Hubbard interaction, the ground-state
is dominated by magnetic correlations.
  These correlations are robust even in the presence of strong frustration.
Interchain pair tunneling is negligible in the singlet and triplet channels and
it is not enhanced by frustration. For weak Hubbard couplings, interchain
non-local singlet pair tunneling is enhanced and magnetic correlations are
strongly reduced. This suggests a possible superconductive ground state.


title:
Proper Motion Dispersions of Red Clump Giants in the Galactic Bulge:
  Observations and Model Comparisons

abstract:
  Red clump giants in the Galactic bulge are approximate standard candles and
hence they can be used as distance indicators. We compute the proper motion
dispersions of RCG stars in the Galactic bulge using the proper motion
catalogue from the second phase of the Optical Gravitational Microlensing
Experiment (OGLE-II, Sumi et al. 2004) for 45 fields. The proper motion
dispersions are measured to a few per cent accuracy due to the large number of
stars in the fields. The observational sample is comprised of 577736 stars.
These observed data are compared to a state-of-the-art particle simulation of
the Galactic bulge region. The predictions are in rough agreement with
observations, but appear to be too anisotropic in the velocity ellipsoid. We
note that there is significant field-to-field variation in the observed proper
motion dispersions. This could either be a real feature, or due to some unknown
systematic effect.


title:
Intramolecular long-range correlations in polymer melts: The segmental
  size distribution and its moments

abstract:
  Presenting theoretical arguments and numerical results we demonstrate
long-range intrachain correlations in concentrated solutions and melts of long
flexible polymers which cause a systematic swelling of short chain segments.
They can be traced back to the incompressibility of the melt leading to an
effective repulsion $u(s) \approx s/\rho R^3(s) \approx ce/\sqrt{s}$ when
connecting two segments together where $s$ denotes the curvilinear length of a
segment, $R(s)$ its typical size, $ce \approx 1/\rho be^3$ the ``swelling
coefficient", $be$ the effective bond length and $\rho$ the monomer density.
The relative deviation of the segmental size distribution from the ideal
Gaussian chain behavior is found to be proportional to $u(s)$. The analysis of
different moments of this distribution allows for a precise determination of
the effective bond length $be$ and the swelling coefficient $ce$ of
asymptotically long chains. At striking variance to the short-range decay
suggested by Flory's ideality hypothesis the bond-bond correlation function of
two bonds separated by $s$ monomers along the chain is found to decay
algebraically as $1/s^{3/2}$. Effects of finite chain length are considered
briefly.


title:
Stability Properties of Strongly Magnetized Spine Sheath Relativistic
  Jets

abstract:
  The linearized relativistic magnetohydrodynamic (RMHD) equations describing a
uniform axially magnetized cylindrical relativistic jet spine embedded in a
uniform axially magnetized relativistically moving sheath are derived. The
displacement current is retained in the equations so that effects associated
with Alfven wave propagation near light speed can be studied. A dispersion
relation for the normal modes is obtained. Analytical solutions for the normal
modes in the low and high frequency limits are found and a general stability
condition is determined. A trans-Alfvenic and even a super-Alfvenic
relativistic jet spine can be stable to velocity shear driven Kelvin-Helmholtz
modes. The resonance condition for maximum growth of the normal modes is
obtained in the kinetically and magnetically dominated regimes. Numerical
solution of the dispersion relation verifies the analytical solutions and is
used to study the regime of high sound and Alfven speeds.


title: MATLAB codes for teaching quantum physics: Part 1

abstract:
  Among the ideas to be conveyed to students in an introductory quantum course,
we have the pivotal idea championed by Dirac that functions correspond to
column vectors (kets) and that differential operators correspond to matrices
(ket-bras) acting on those vectors. The MATLAB (matrix-laboratory) programming
environment is especially useful in conveying these concepts to students
because it is geared towards the type of matrix manipulations useful in solving
introductory quantum physics problems. In this article, we share MATLAB codes
which have been developed at WPI, focusing on 1D problems, to be used in
conjunction with Griffiths' introductory text.


title: Nanodevices and Maxwell's Demon

abstract:
  In the last twenty years there has been significant progress in our
understanding of quantum transport far from equilibrium and a conceptual
framework has emerged through a combination of the Landauer approach with the
non-equilibrium Green function (NEGF) method, which is now being widely used in
the analysis and design of nanoscale devices. It provides a unified description
for all kinds of devices from molecular conductors to carbon nanotubes to
silicon transistors covering different transport regimes from the ballistic to
the diffusive limit. In this talk I use a simple version of this model to
analyze a specially designed device that could be called an electronic
Maxwell's demon, one that lets electrons go preferentially in one direction
over another. My objective is to illustrate the fundamental role of contacts
and demons in transport and energy conversion. The discussion is kept at an
academic level steering clear of real world details, but the illustrative
devices we use are very much within the capabilities of present-day technology.
For example, recent experiments on thermoelectric effects in molecular
conductors agree well with the predictions from our model. The Maxwell's demon
device itself is very similar to the pentalayer spin-torque device which has
been studied by a number of groups though we are not aware of any discussion of
the possibility of using the device as a nanoscale heat engine or as a
refrigerator as proposed here. However, my objective is not to evaluate
possible practical applications. Rather it is to introduce a simple transparent
model showing how out-of-equibrium demons suitably incorporated into
nanodevices can achieve energy conversion.


title: Complete Segal spaces arising from simplicial categories

abstract:
  In this paper, we compare several functors which take simplicial categories
or model categories to complete Segal spaces, which are particularly nice
simplicial spaces which, like simplicial categories, can be considered to be
models for homotopy theories. We then give a characterization, up to weak
equivalence, of complete Segal spaces arising from these functors.


title: A Systematic Scan for 7-colourings of the Grid

abstract:
  We study the mixing time of a systematic scan Markov chain for sampling from
the uniform distribution on proper 7-colourings of a finite rectangular
sub-grid of the infinite square lattice, the grid. A systematic scan Markov
chain cycles through finite-size subsets of vertices in a deterministic order
and updates the colours assigned to the vertices of each subset. The systematic
scan Markov chain that we present cycles through subsets consisting of 2x2
sub-grids and updates the colours assigned to the vertices using a procedure
known as heat-bath. We give a computer-assisted proof that this systematic scan
Markov chain mixes in O(log n) scans, where n is the size of the rectangular
sub-grid. We make use of a heuristic to compute required couplings of
colourings of 2x2 sub-grids. This is the first time the mixing time of a
systematic scan Markov chain on the grid has been shown to mix for less than 8
colours. We also give partial results that underline the challenges of proving
rapid mixing of a systematic scan Markov chain for sampling 6-colourings of the
grid by considering 2x3 and 3x3 sub-grids.


title: Magnetic exponents of two-dimensional Ising spin glasses

abstract:
  The magnetic critical properties of two-dimensional Ising spin glasses are
controversial. Using exact ground state determination, we extract the
properties of clusters flipped when increasing continuously a uniform field. We
show that these clusters have many holes but otherwise have statistical
properties similar to those of zero-field droplets. A detailed analysis gives
for the magnetization exponent delta = 1.30 +/- 0.02 using lattice sizes up to
80x80; this is compatible with the droplet model prediction delta = 1.282. The
reason for previous disagreements stems from the need to analyze both singular
and analytic contributions in the low-field regime.


title:
Thin elastic shells with variable thickness for lithospheric flexure of
  one-plate planets

abstract:
  Planetary topography can either be modeled as a load supported by the
lithosphere, or as a dynamical effect due to lithospheric flexure caused by
mantle convection. In both cases the response of the lithosphere to external
forces can be calculated with the theory of thin elastic plates or shells. On
one-plate planets the spherical geometry of the lithospheric shell plays an
important role in the flexure mechanism. So far the equations governing the
deformations and stresses of a spherical shell have only been derived under the
assumption of a shell of constant thickness. However local studies of gravity
and topography data suggest large variations in the thickness of the
lithosphere. In this article we obtain the scalar flexure equations governing
the deformations of a thin spherical shell with variable thickness or variable
Young's modulus. The resulting equations can be solved in succession, except
for a system of two simultaneous equations, the solutions of which are the
transverse deflection and an associated stress function. In order to include
bottom loading generated by mantle convection, we extend the method of stress
functions to include loads with a toroidal tangential component. We further
show that toroidal tangential displacement always occurs if the shell thickness
varies, even in the absence of toroidal loads. We finally prove that the
degree-one harmonic components of the transverse deflection and of the toroidal
tangential displacement are independent of the elastic properties of the shell
and are associated with translational and rotational freedom. The flexure
equations for a shell of variable thickness are useful not only for the
prediction of the gravity signal in local admittance studies, but also for the
construction of stress maps in tectonic analysis.


title: Detection of single electron spin resonance in a double quantum dot

abstract:
  Spin-dependent transport measurements through a double quantum dot are a
valuable tool for detecting both the coherent evolution of the spin state of a
single electron as well as the hybridization of two-electron spin states. In
this paper, we discuss a model that describes the transport cycle in this
regime, including the effects of an oscillating magnetic field (causing
electron spin resonance) and the effective nuclear fields on the spin states in
the two dots. We numerically calculate the current flow due to the induced spin
flips via electron spin resonance and we study the detector efficiency for a
range of parameters. The experimental data are compared with the model and we
find a reasonable agreement.


title: Donor type semiconductor at low temperature as maser active medium

abstract:
  In some semiconductors donor impurity atoms can attract additional electrons,
forming negative donor impurity ions. Thus we have 3 energy levels for
electrons: zero energy levels at the bottom of the conductivity band, negative
energy levels of the bounded electrons of the negative donor impurity ions, and
deeper negative energy levels of the outer electrons of the neutral donor
impurity atoms. So the donor impurity atoms could serve as active centres for a
maser. The maximum achievable relative population is 0.5. Typical wavelength of
the generated oscillation is 0.14 mm; three level scheme could be realized at
rather low temperatures, considerably lower than 6 K.


title:
Exciting the Magnetosphere of the Magnetar CXOU J164710.2-455216 in
  Westerlund 1

abstract:
  We describe XMM-Newton observations taken 4.3 days prior to and 1.5 days
subsequent to two remarkable events that were detected with Swift on 2006
September 21 from the candidate magnetar CXOU J164710.2-455216: (1) a 20 ms
burst with an energy of 1e37 erg (15-150 keV), and (2) a rapid spin-down
(glitch) with a fractionap period change of 1e-4. We find that the luminosity
of the pulsar increased by a factor of 100 in the interval between
observations, from 1e33 to 1e35 erg/s (0.5-8.0 keV), and that its spectrum
hardened. The pulsed count rate increased by a factor of 10 (0.5-8.0 keV), but
the fractional rms amplitude of the pulses decreased from 65 to 11 per cent,
and their profile changed from being single-peaked to exhibiting three peaks.
Similar changes have been observed from other magnetars in response to
outbursts, such as that of 1E 2259+586 in 2002 June. We suggest that a plastic
deformation of the neutron star's crust induced a very slight twist in the
external magnetic field, which in turn generated currents in the magnetosphere
that were the direct cause of the X-ray outburst.


title:
Further Evidence that the Redshifts of AGN Galaxies May Contain
  Intrinsic Components

abstract:
  In the decreasing intrinsic redshift (DIR) model galaxies are assumed to be
born as compact objects that have been ejected with large intrinsic redshift
components, z_(i), out of the nuclei of mature AGN galaxies. As young AGN
(quasars) they are initially several magnitudes sub-luminous to mature galaxies
but their luminosity gradually increases over 10^8 yrs, as z_(i) decreases and
they evolve into mature AGN (Seyferts and radio galaxies). Evidence presented
here that low- and intermediate-redshift AGN are unquestionably sub-luminous to
radio galaxies is then strong support for this model and makes it likely that
the high-redshift AGN (quasars) are also sub-luminous, having simply been
pushed above the radio galaxies on a logz-m_(v) plot by the presence of a large
intrinsic component in their redshifts. An increase in luminosity below z =
0.06 is also seen. It is associated in the DIR model with an increase in
luminosity as the sources mature but, if real, is difficult to interpret in the
cosmological redshift (CR) model since at this low redshift it is unlikely to
be associated with a higher star formation rate or an increase in the material
used to build galaxies. Whether it might be possible in the CR model to explain
these results by selection effects is also examined.


title: Semiclassical scattering amplitude at the maximum point of the potential

abstract:
  We compute the scattering amplitude for Schr\"odinger operators at a critical
energy level, corresponding to the maximum point of the potential. We follow
the wrok of Robert and Tamura, '89, using Isozaki and Kitada's representation
formula for the scattering amplitude, together with results from Bony, Fujiie,
Ramond and Zerzeri '06 in order to analyze the contribution of trapped
trajectories.


title: Hilbert Spaces with Generic Predicates

abstract:
  We study the model theory of expansions of Hilbert spaces by generic
predicates. We first prove the existence of model companions for generic
expansions of Hilbert spaces in the form first of a distance function to a
random substructure, then a distance to a random subset. The theory obtained
with the random substructure is {\omega}-stable, while the one obtained with
the distance to a random subset is $TP_2$ and $NSOP_1$. That example is the
first continuous structure in that class.


title: Riggings of locally compact abelian groups

abstract:
  We obtain a set of generalized eigenvectors that provides a generalized
spectral decomposition for a given unitary representation of a commutative,
locally compact topological group. These generalized eigenvectors are
functionals belonging to the dual space of a rigging on the space of square
integrable functions on the character group. These riggings are obtained
through suitable spectral measure spaces.


title: Weak Amenability of Hyperbolic Groups

abstract:
  We prove that hyperbolic groups are weakly amenable. This partially extends
the result of Cowling and Haagerup showing that lattices in simple Lie groups
of real rank one are weakly amenable. We take a combinatorial approach in the
spirit of Haagerup and prove that for the word length metric d on a hyperbolic
group, the Schur multipliers associated with r^d have uniformly bounded norms
for 0<r<1. We then combine this with a Bozejko-Picardello type inequality to
obtain weak amenability.


title:
Light Curves of Dwarf Plutonian Planets and other Large Kuiper Belt
  Objects: Their Rotations, Phase Functions and Absolute Magnitudes

abstract:
  (Abridged) I report new light curves and determine the rotations and phase
functions of several large Kuiper Belt objects, including the dwarf planet Eris
(2003 UB313). (120348) 2004 TY364 shows a light curve which if double-peaked
has a period of 11.70+-0.01 hours and peak-to-peak amplitude of 0.22+-0.02
magnitudes. (84922) 2003 VS2 has a well defined double-peaked light curve of
7.41+-0.02 hours with a 0.21+-0.02 magnitude range. (126154) 2001 YH140 shows
variability of 0.21+-0.04 magnitudes with a possible 13.25+-0.2 hour
single-peaked period. The seven new KBOs in the sample which show no
discernible variations within the uncertainties on short rotational time scales
are 2001 UQ18, (55565) 2002 AW197, (119979) 2002 WC19, (120132) 2003 FY128,
(136108) Eris 2003 UB313, (90482) Orcus 2004 DW, and (90568) 2004 GV9. The
three medium to large sized Kuiper Belt objects 2004 TY364, Orcus and 2004 GV9
show fairly steep linear phase curves (~0.18 to 0.26 mags per degree) between
phase angles of 0.1 and 1.5 degrees. The extremely large dwarf planet Eris
(2003 UB313) shows a shallower phase curve (0.09+-0.03 mags per degree) which
is more similar to the other known dwarf planet Pluto. It appears the surface
properties of the largest dwarf planets in the Kuiper Belt maybe different than
the smaller Kuiper Belt objects. This may have to do with the larger objects
ability to hold more volatile ices as well as sustain atmospheres. The absolute
magnitudes obtained using the measured phase slopes are a few tenths of
magnitudes different from those given by the MPC.


title: Fischler-Susskind holographic cosmology revisited

abstract:
  When Fischler and Susskind proposed a holographic prescription based on the
Particle Horizon, they found that spatially closed cosmological models do not
verify it due to the apparently unavoidable recontraction of the Particle
Horizon area. In this article, after a short review of their original work, we
expose graphically and analytically that spatially closed cosmological models
can avoid this problem if they expand fast enough. It has been also shown that
the Holographic Principle is saturated for a codimension one brane dominated
Universe. The Fischler-Susskind prescription is used to obtain the maximum
number of degrees of freedom per Planck volume at the Planck era compatible
with the Holographic Principle.


title:
Accelerated expansion of the Universe filled up with the scalar
  gravitons

abstract:
  The concept of the scalar graviton as the source of the dark matter and dark
energy of the gravitaional origin is applied to study the evolution of the
isotropic homogeneous Universe. A realistic self-consistent solution to the
modified pure gravity equations, which correctly describes the accelerated
expansion of the spatially flat Universe, is found and investigated. It is
argued that the scenario with the scalar gravitons filling up the Universe may
emulate the LCDM model, reducing thus the true dark matter to an artefact.


title: Parity doubling in particle physics

abstract:
  Parity doubling in excited hadrons is reviewed. Parity degeneracy in hadrons
was first experimentally observed 40 years ago. Recently new experimental data
on light mesons caused much excitement and renewed interest to the phenomenon,
which still remains to be enigmatic. The present retrospective review is an
attempt to trace the history of parity doubling phenomenon, thus providing a
kind of introduction to the subject. We begin with early approaches of 1960s
(Regge theory and dynamical symmetries) and end up with the latest trends
(manifestations of broader degeneracies and AdS/QCD). We show the evolution of
various ideas about parity doubling. The experimental evidence for this
phenomenon is scrutinized in the non-strange sector. Some experiments of 1960s
devoted to the search for missing non-strange bosons are re-examined and it is
argued that results of these experiments are encouraging from the modern
perspective.


title: Bergman kernels and equilibrium measures for ample line bundles

abstract:
  Let L be an ample holomorphic line bundle over a compact complex Hermitian
manifold X. Any fixed smooth Hermitian metric on L induces a Hilbert space
structure on the space of global holomorphic sections with values in the k:th
tensor power of L. In this paper various convergence results are obtained for
the corresponding Bergman kernels. The convergence is studied in the large k
limit and is expressed in terms of the equilibrium metric associated to the
fixed metric, as well as in terms of the Monge-Ampere measure of the fixed
metric itself on a certain support set. It is also shown that the equilibrium
metric has Lipschitz continuous first derivatives. These results can be seen as
generalizations of well-known results concerning the case when the curvature of
the fixed metric is positive (the corresponding equilibrium metric is then
simply the fixed metric itself).


title: U Geminorum: a test case for orbital parameters determination

abstract:
  High-resolution spectroscopy of U Gem was obtained during quiescence. We did
not find a hot spot or gas stream around the outer boundaries of the accretion
disk. Instead, we detected a strong narrow emission near the location of the
secondary star. We measured the radial velocity curve from the wings of the
double-peaked H$\alpha$ emission line, and obtained a semi-amplitude value that
is in excellent agreement with the obtained from observations in the
ultraviolet spectral region by Sion et al. (1998). We present also a new method
to obtain K_2, which enhances the detection of absorption or emission features
arising in the late-type companion. Our results are compared with published
values derived from the near-infrared NaI line doublet. From a comparison of
the TiO band with those of late type M stars, we find that a best fit is
obtained for a M6V star, contributing 5 percent of the total light at that
spectral region. Assuming that the radial velocity semi-amplitudes reflect
accurately the motion of the binary components, then from our results: K_em =
107+/-2 km/s; K_abs = 310+/-5 km/s, and using the inclination angle given by
Zhang & Robinson(1987); i = 69.7+/-0.7, the system parameters become: M_WD =
1.20+/-0.05 M_sun,; M_RD = 0.42+/-0.04 M_sun; and a = 1.55+/- 0.02 R_sun. Based
on the separation of the double emission peaks, we calculate an outer disk
radius of R_out/a ~0.61, close to the distance of the inner Lagrangian point
L_1/a~0.63. Therefore we suggest that, at the time of observations, the
accretion disk was filling the Roche-Lobe of the primary, and that the matter
leaving the L_1 point was colliding with the disc directly, producing the hot
spot at this location.


title:
Collective excitations of hard-core Bosons at half filling on square and
  triangular lattices: Development of roton minima and collapse of roton gap

abstract:
  We study ground state properties and excitation spectra for hard-core Bosons
on square and triangular lattices, at half filling, using series expansion
methods. Nearest-neighbor repulsion between the Bosons leads to the development
of short-range density order at the antiferromagnetic wavevector, and
simultaneously a roton minima in the density excitation spectra. On the
square-lattice, the model maps on to the well studied XXZ model, and the roton
gap collapses to zero precisely at the Heisenberg symmetry point, leading to
the well known spectra for the Heisenberg antiferromagnet. On the
triangular-lattice, the collapse of the roton gap signals the onset of the
supersolid phase. Our results suggest that the transition from the superfluid
to the supersolid phase maybe weakly first order. We also find several features
in the density of states, including two-peaks and a sharp discontinuity, which
maybe observable in experimental realization of such systems.


title: The LIL for $U$-statistics in Hilbert spaces

abstract:
  We give necessary and sufficient conditions for the (bounded) law of the
iterated logarithm for $U$-statistics in Hilbert spaces. As a tool we also
develop moment and tail estimates for canonical Hilbert-space valued
$U$-statistics of arbitrary order, which are of independent interest.


title: Circulating Current States in Bilayer Fermionic and Bosonic Systems

abstract:
  It is shown that fermionic polar molecules or atoms in a bilayer optical
lattice can undergo the transition to a state with circulating currents, which
spontaneously breaks the time reversal symmetry. Estimates of relevant
temperature scales are given and experimental signatures of the circulating
current phase are identified. Related phenomena in bosonic and spin systems
with ring exchange are discussed.


title: Non-Relativistic Propagators via Schwinger's Method

abstract:
  In order to popularize the so called Schwinger's method we reconsider the
Feynman propagator of two non-relativistic systems: a charged particle in a
uniform magnetic field and a charged harmonic oscillator in a uniform magnetic
field. Instead of solving the Heisenberg equations for the position and the
canonical momentum operators, ${\bf R}$ and ${\bf P}$, we apply this method by
solving the Heisenberg equations for the gauge invariant operators ${\bf R}$
and $\mathversion{bold}${\pi}$ = {\bf P}-e{\bf A}$, the latter being the
mechanical momentum operator. In our procedure we avoid fixing the gauge from
the beginning and the result thus obtained shows explicitly the gauge
dependence of the Feynman propagator.


title: A linear RFQ ion trap for the Enriched Xenon Observatory

abstract:
  The design, construction, and performance of a linear radio-frequency ion
trap (RFQ) intended for use in the Enriched Xenon Observatory (EXO) are
described. EXO aims to detect the neutrinoless double-beta decay of $^{136}$Xe
to $^{136}$Ba. To suppress possible backgrounds EXO will complement the
measurement of decay energy and, to some extent, topology of candidate events
in a Xe filled detector with the identification of the daughter nucleus
($^{136}$Ba). The ion trap described here is capable of accepting, cooling, and
confining individual Ba ions extracted from the site of the candidate
double-beta decay event. A single trapped ion can then be identified, with a
large signal-to-noise ratio, via laser spectroscopy.


title:
How much entropy is produced in strongly coupled Quark-Gluon Plasma
  (sQGP) by dissipative effects?

abstract:
  We argue that estimates of dissipative effects based on the first-order
hydrodynamics with shear viscosity are potentially misleading because higher
order terms in the gradient expansion of the dissipative part of the stress
tensor tend to reduce them. Using recently obtained sound dispersion relation
in thermal $\cal N$=4 supersymmetric plasma, we calculate the $resummed$ effect
of these high order terms for Bjorken expansion appropriate to RHIC/LHC
collisions. A reduction of entropy production is found to be substantial, up to
an order of magnitude.


title: Spectral Analysis of the Chandra Comet Survey

abstract:
  We present results of the analysis of cometary X-ray spectra with an extended
version of our charge exchange emission model (Bodewits et al. 2006). We have
applied this model to the sample of 8 comets thus far observed with the Chandra
X-ray observatory and ACIS spectrometer in the 300-1000 eV range. The surveyed
comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), C/2000 WM1
(LINEAR), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), C/2001 Q4 (NEAT), 9P/2005
(Tempel 1) and 73P/2006-B (Schwassmann-Wachmann 3) and the observations include
a broad variety of comets, solar wind environments and observational
conditions. The interaction model is based on state selective, velocity
dependent charge exchange cross sections and is used to explore how cometary
X-ray emission depend on cometary, observational and solar wind
characteristics. It is further demonstrated that cometary X-ray spectra mainly
reflect the state of the local solar wind. The current sample of Chandra
observations was fit using the constrains of the charge exchange model, and
relative solar wind abundances were derived from the X-ray spectra. Our
analysis showed that spectral differences can be ascribed to different solar
wind states, as such identifying comets interacting with (I) fast, cold wind,
(II), slow, warm wind and (III) disturbed, fast, hot winds associated with
interplanetary coronal mass ejections. We furthermore predict the existence of
a fourth spectral class, associated with the cool, fast high latitude wind.


title: Hamiltonian formalism in a problem of 3-th waves hierarchy

abstract:
  By the method of discrete transformation equations of 3-th wave hierarchy are
constructed. We present in explicit form two Poisson structures, which allow to
construct Hamiltonian operator consequent application of which leads to all
equations of this hierarchy. For calculations it will be necessary results of
previous paper \cite{1}, which for convenience of the reader we present in
corresponding place of the text. The obtained formulae are checked by
independent calculations.


title:
Correlations, fluctuations and stability of a finite-size network of
  coupled oscillators

abstract:
  The incoherent state of the Kuramoto model of coupled oscillators exhibits
marginal modes in mean field theory. We demonstrate that corrections due to
finite size effects render these modes stable in the subcritical case, i.e.
when the population is not synchronous. This demonstration is facilitated by
the construction of a non-equilibrium statistical field theoretic formulation
of a generic model of coupled oscillators. This theory is consistent with
previous results. In the all-to-all case, the fluctuations in this theory are
due completely to finite size corrections, which can be calculated in an
expansion in 1/N, where N is the number of oscillators. The N -> infinity limit
of this theory is what is traditionally called mean field theory for the
Kuramoto model.


title: Route to Lambda in conformally coupled phantom cosmology

abstract:
  In this letter we investigate acceleration in the flat cosmological model
with a conformally coupled phantom field and we show that acceleration is its
generic feature. We reduce the dynamics of the model to a 3-dimensional
dynamical system and analyze it on a invariant 2-dimensional submanifold. Then
the concordance FRW model with the cosmological constant $\Lambda$ is a global
attractor situated on a 2-dimensional invariant space. We also study the
behaviour near this attractor, which can be approximated by the dynamics of the
linearized part of the system. We demonstrate that trajectories of the
conformally coupled phantom scalar field with a simple quadratic potential
crosses the cosmological constant barrier infinitely many times in the phase
space. The universal behaviour of the scalar field and its potential is also
calculated. We conclude that the phantom scalar field conformally coupled to
gravity gives a natural dynamical mechanism of concentration of the equation of
state coefficient around the magical value $w_{\text{eff}}=-1$. We demonstrate
route to Lambda through the infinite times crossing the $w_{\text{eff}}=-1$
phantom divide.


title: Interaction of Supernova Ejecta with Nearby Protoplanetary Disks

abstract:
  The early Solar System contained short-lived radionuclides such as 60Fe (t1/2
= 1.5 Myr) whose most likely source was a nearby supernova. Previous models of
Solar System formation considered a supernova shock that triggered the collapse
of the Sun's nascent molecular cloud. We advocate an alternative hypothesis,
that the Solar System's protoplanetary disk had already formed when a very
close (< 1 pc) supernova injected radioactive material directly into the disk.
We conduct the first numerical simulations designed to answer two questions
related to this hypothesis: will the disk be destroyed by such a close
supernova; and will any of the ejecta be mixed into the disk? Our simulations
demonstrate that the disk does not absorb enough momentum from the shock to
escape the protostar to which it is bound. Only low amounts (< 1%) of mass loss
occur, due to stripping by Kelvin-Helmholtz instabilities across the top of the
disk, which also mix into the disk about 1% of the intercepted ejecta. These
low efficiencies of destruction and injectation are due to the fact that the
high disk pressures prevent the ejecta from penetrating far into the disk
before stalling. Injection of gas-phase ejecta is too inefficient to be
consistent with the abundances of radionuclides inferred from meteorites. On
the other hand, the radionuclides found in meteorites would have condensed into
dust grains in the supernova ejecta, and we argue that such grains will be
injected directly into the disk with nearly 100% efficiency. The meteoritic
abundances of the short-lived radionuclides such as 60Fe therefore are
consistent with injection of grains condensed from the ejecta of a nearby (< 1
pc) supernova, into an already-formed protoplanetary disk.


title: Scaling cosmologies, geodesic motion and pseudo-susy

abstract:
  One-parameter solutions in supergravity carried by scalars and a metric trace
out curves on the scalar manifold. In ungauged supergravity these curves
describe a geodesic motion. It is known that a geodesic motion sometimes occurs
in the presence of a scalar potential and for time-dependent solutions this can
happen for scaling cosmologies. This note contains a further study of such
solutions in the context of pseudo-supersymmetry for multi-field systems whose
first-order equations we derive using a Bogomol'nyi-like method. In particular
we show that scaling solutions that are pseudo-BPS must describe geodesic
curves. Furthermore, we clarify how to solve the geodesic equations of motion
when the scalar manifold is a maximally non-compact coset such as occurs in
maximal supergravity. This relies upon a parametrization of the coset in the
Borel gauge. We then illustrate this with the cosmological solutions of
higher-dimensional gravity compactified on a $n$-torus.


title:
The Peculiar Velocities of Local Type Ia Supernovae and their Impact on
  Cosmology

abstract:
  We quantify the effect of supernova Type Ia peculiar velocities on the
derivation of cosmological parameters. The published distant and local Ia SNe
used for the Supernova Legacy Survey first-year cosmology report form the
sample for this study. While previous work has assumed that the local SNe are
at rest in the CMB frame (the No Flow assumption), we test this assumption by
applying peculiar velocity corrections to the local SNe using three different
flow models. The models are based on the IRAS PSCz galaxy redshift survey, have
varying beta = Omega_m^0.6/b, and reproduce the Local Group motion in the CMB
frame. These datasets are then fit for w, Omega_m, and Omega_Lambda using
flatness or LambdaCDM and a BAO prior. The chi^2 statistic is used to examine
the effect of the velocity corrections on the quality of the fits. The most
favored model is the beta=0.5 model, which produces a fit significantly better
than the No Flow assumption, consistent with previous peculiar velocity
studies. By comparing the No Flow assumption with the favored models we derive
the largest potential systematic error in w caused by ignoring peculiar
velocities to be Delta w = +0.04. For Omega_Lambda, the potential error is
Delta Omega_Lambda = -0.04 and for Omega_m, the potential error is Delta
Omega_m < +0.01. The favored flow model (beta=0.5) produces the following
cosmological parameters: w = -1.08 (+0.09,-0.08), Omega_m = 0.27 (+0.02,-0.02)
assuming a flat cosmology, and Omega_Lambda = 0.80 (+0.08,-0.07) and Omega_m =
0.27 (+0.02,-0.02) for a w = -1 (LambdaCDM) cosmology.


title: Creation of Quark-gluon Plasma in Celestial Laboratories

abstract:
  It is shown that a gravitationally collapsing black hole acts as an ultrahigh
energy particle accelerator that can accelerate particles to energies
inconceivable in any terrestrial particle accelerator, and that when the energy
E of the particles comprising the matter in the black hole is $ \sim 10^{2} $
GeV or more,or equivalently the temperature T is $ \sim 10^{15}$ K or more, the
entire matter in the black hole will be in the form of quark-gluon plasma
permeated by leptons.


title:
Temperature-driven transition from the Wigner Crystal to the
  Bond-Charge-Density Wave in the Quasi-One-Dimensional Quarter-Filled band

abstract:
  It is known that within the interacting electron model Hamiltonian for the
one-dimensional 1/4-filled band, the singlet ground state is a Wigner crystal
only if the nearest neighbor electron-electron repulsion is larger than a
critical value. We show that this critical nearest neighbor Coulomb interaction
is different for each spin subspace, with the critical value decreasing with
increasing spin. As a consequence, with the lowering of temperature, there can
occur a transition from a Wigner crystal charge-ordered state to a spin-Peierls
state that is a Bond-Charge-Density Wave with charge occupancies different from
the Wigner crystal. This transition is possible because spin excitations from
the spin-Peierls state in the 1/4-filled band are necessarily accompanied by
changes in site charge densities. We apply our theory to the 1/4-filled band
quasi-one-dimensional organic charge-transfer solids in general and to 2:1
tetramethyltetrathiafulvalene (TMTTF) and tetramethyltetraselenafulvalene
(TMTSF) cationic salts in particular. We believe that many recent experiments
strongly indicate the Wigner crystal to Bond-Charge-Density Wave transition in
several members of the TMTTF family. We explain the occurrence of two different
antiferromagnetic phases but a single spin-Peierls state in the generic phase
diagram for the 2:1 cationic solids. The antiferromagnetic phases can have
either the Wigner crystal or the Bond-Charge-Spin-Density Wave charge
occupancies. The spin-Peierls state is always a Bond-Charge-Density Wave.


title: Bubbling Surface Operators And S-Duality

abstract:
  We construct smooth asymptotically AdS_5xS^5 solutions of Type IIB
supergravity corresponding to all the half-BPS surface operators in N=4 SYM.
All the parameters labeling a half-BPS surface operator are identified in the
corresponding bubbling geometry. We use the supergravity description of surface
operators to study the action of the SL(2,Z) duality group of N=4 SYM on the
parameters of the surface operator, and find that it coincides with the recent
proposal by Gukov and Witten in the framework of the gauge theory approach to
the geometrical Langlands with ramification. We also show that whenever a
bubbling geometry becomes singular that the path integral description of the
corresponding surface operator also becomes singular.


title: Resolving Cosmic Gamma Ray Anomalies with Dark Matter Decaying Now

abstract:
  Dark matter particles need not be completely stable, and in fact they may be
decaying now. We consider this possibility in the frameworks of universal extra
dimensions and supersymmetry with very late decays of WIMPs to Kaluza-Klein
gravitons and gravitinos. The diffuse photon background is a sensitive probe,
even for lifetimes far greater than the age of the Universe. Remarkably, both
the energy spectrum and flux of the observed MeV gamma ray excess may be
naturally explained by decaying dark matter with MeV mass splittings. Future
observations of continuum and line photon fluxes will test this explanation and
may provide novel constraints on cosmological parameters.


title: Neutrino-cooled accretion and GRB variability

abstract:
  For accretion rates Mdot~0.1 Msun/s to a few solar mass black hole the inner
part of the disk is expected to make a transition from advection dominance to
neutrino cooling. This transition is characterized by sharp changes of the disk
properties. I argue here that during this transition, a modest increase of the
accretion rate leads to powerful enhancement of the Poynting luminosity of the
GRB flow and decrease of its baryon loading. These changes of the
characteristics of the GRB flow translate into changing gamma-ray spectra from
the photosphere of the flow. The photospheric interpretation of the GRB
emission explains the observed narrowing of GRB pulses with increasing photon
energy and the luminosity-spectral peak relation within and among bursts.


title: The VVDS type-1 AGN sample: The faint end of the luminosity function

abstract:
  In a previous paper (Gavignaud et al. 2006), we presented the type-1 Active
Galactic Nuclei (AGN) sample obtained from the first epoch data of the
VIMOS-VLT Deep Survey (VVDS). The sample consists of 130 faint, broad-line AGN
with redshift up to z=5 and 17.5< I <24.0, selected on the basis of their
spectra. In this paper we present the measurement of the Optical Luminosity
Function up to z=3.6 derived from this sample, we compare our results with
previous results from brighter samples both at low and at high redshift. Our
data, more than one magnitude fainter than previous optical surveys, allow us
to constrain the faint part of the luminosity function up to high redshift. By
combining our faint VVDS sample with the large sample of bright AGN extracted
from the SDSS DR3 (Richards et al., 2006b) and testing a number of different
evolutionary models, we find that the model which better represents the
combined luminosity functions, over a wide range of redshift and luminosity, is
a luminosity dependent density evolution (LDDE) model, similar to those derived
from the major X-surveys. Such a parameterization allows the redshift of the
AGN space density peak to change as a function of luminosity and explains the
excess of faint AGN that we find at 1.0< z <1.5. On the basis of this model we
find, for the first time from the analysis of optically selected samples, that
the peak of the AGN space density shifts significantly towards lower redshift
going to lower luminosity objects. This result, already found in a number of
X-ray selected samples of AGN, is consistent with a scenario of "AGN cosmic
downsizing", in which the density of more luminous AGN, possibly associated to
more massive black holes, peaks earlier in the history of the Universe, than
that of low luminosity ones.


title: Can a Black Hole Collapse to a Space-time Singularity?

abstract:
  A critique of the singularity theorems of Penrose, Hawking, and Geroch is
given. It is pointed out that a gravitationally collapsing black hole acts as
an ultrahigh energy particle accelerator that can accelerate particles to
energies inconceivable in any terrestrial particle accelerator, and that when
the energy $E$ of the particles comprising matter in a black hole is $\sim
10^{2} GeV$ or more, or equivalently, the temperature $T$ is $\sim 10^{15} K$
or more, the entire matter in the black hole is converted into quark-gluon
plasma permeated by leptons. As quarks and leptons are fermions, it is
emphasized that the collapse of a black-hole to a space-time singularity is
inhibited by Pauli's exclusion principle. It is also suggested that ultimately
a black hole may end up either as a stable quark star, or as a pulsating quark
star which may be a source of gravitational radiation, or it may simply explode
with a mini bang of a sort.


title:
Right-Handed Quark Mixings in Minimal Left-Right Symmetric Model with
  General CP Violation

abstract:
  We present a systematic approach to solve analytically for the right-handed
quark mixings in the minimal left-right symmetric model which generally has
both explicit and spontaneous CP violations. The leading-order result has the
same hierarchical structure as the left-handed CKM mixing, but with additional
CP phases originating from a spontaneous CP-violating phase in the Higgs vev.
We explore the phenomenology entailed by the new right-handed mixing matrix,
particularly the bounds on the mass of $W_R$ and the CP phase of the Higgs vev.


title: Dynamics of single polymers under extreme confinement

abstract:
  We study the dynamics of a single chain polymer confined to a two dimensional
cell. We introduce a kinetically constrained lattice gas model that preserves
the connectivity of the chain, and we use this kinetically constrained model to
study the dynamics of the polymer at varying densities through Monte Carlo
simulations. Even at densities close to the fully-packed configuration, we find
that the monomers comprising the chain manage to diffuse around the box with a
root mean square displacement of the order of the box dimensions over time
scales for which the overall geometry of the polymer is, nevertheless, largely
preserved. To capture this shape persistence, we define the local tangent field
and study the two-time tangent-tangent correlation function, which exhibits a
glass-like behavior. In both closed and open chains, we observe reptational
motion and reshaping through local fingering events which entail global monomer
displacement.


title:
Diffuse Optical Light in Galaxy Clusters II: Correlations with Cluster
  Properties

abstract:
  We have measured the flux, profile, color, and substructure in the diffuse
intracluster light (ICL) in a sample of ten galaxy clusters with a range of
mass, morphology, redshift, and density. Deep, wide-field observations for this
project were made in two bands at the one meter Swope and 2.5 meter du Pont
telescope at Las Campanas Observatory. Careful attention in reduction and
analysis was paid to the illumination correction, background subtraction, point
spread function determination, and galaxy subtraction. ICL flux is detected in
both bands in all ten clusters ranging from 7.6 x 10^{10} to 7.0 x 10^{11}
h^{-1} solar luminosities in r and 1.4 x 10^{10} to 1.2 x 10^{11} h^{-1} solar
luminosities in the B-band. These fluxes account for 6 to 22% of the total
cluster light within one quarter of the virial radius in r and 4 to 21% in the
B-band. Average ICL B-r colors range from 1.5 to 2.8 mags when k and evolution
corrected to the present epoch. In several clusters we also detect ICL in group
environments near the cluster center and up to ~1 h^{-1} Mpc distant from the
cluster center. Our sample, having been selected from the Abell sample, is
incomplete in that it does not include high redshift clusters with low density,
low flux, or low mass, and it does not include low redshift clusters with high
flux, mass, or density. This bias makes it difficult to interpret correlations
between ICL flux and cluster properties. Despite this selection bias, we do
find that the presence of a cD galaxy corresponds to both centrally
concentrated galaxy profiles and centrally concentrated ICL profiles. This is
consistent with ICL either forming from galaxy interactions at the center, or
forming at earlier times in groups and later combining in the center.


title:
Approach to Physical Reality: a note on Poincare Group and the
  philosophy of Nagarjuna

abstract:
  We argue about a possible scenario of physical reality based on the
parallelism between Poincare group and the sunyata philosophy of Nagarjuna. The
notion of "relational" is the common denominator of two views. We have
approached the relational concept in third-person perspective (ontic level). It
is possible to deduce different physical consequence and interpretation through
first-person perspective approach. This relational interpretation leave open
the questions: i)we must abandon the idea for a physical system the possibility
to extract completeness information? ii)we must abandon the idea to infer a
possible structure of physical reality?


title: Ultraviolet Observations of Supernovae

abstract:
  The motivations to make ultraviolet (UV) studies of supernovae (SNe) are
reviewed and discussed in the light of the results obtained so far by means of
IUE and HST observations. It appears that UV studies of SNe can, and do lead to
fundamental results not only for our understanding of the SN phenomenon, such
as the kinematics and the metallicity of the ejecta, but also for exciting new
findings in Cosmology, such as the tantalizing evidence for "dark energy" that
seems to pervade the Universe and to dominate its energetics. The need for
additional and more detailed UV observations is also considered and discussed.


title: Stochastic fluctuations in metabolic pathways

abstract:
  Fluctuations in the abundance of molecules in the living cell may affect its
growth and well being. For regulatory molecules (e.g., signaling proteins or
transcription factors), fluctuations in their expression can affect the levels
of downstream targets in a network. Here, we develop an analytic framework to
investigate the phenomenon of noise correlation in molecular networks.
Specifically, we focus on the metabolic network, which is highly inter-linked,
and noise properties may constrain its structure and function. Motivated by the
analogy between the dynamics of a linear metabolic pathway and that of the
exactly soluable linear queueing network or, alternatively, a mass transfer
system, we derive a plethora of results concerning fluctuations in the
abundance of intermediate metabolites in various common motifs of the metabolic
network. For all but one case examined, we find the steady-state fluctuation in
different nodes of the pathways to be effectively uncorrelated. Consequently,
fluctuations in enzyme levels only affect local properties and do not propagate
elsewhere into metabolic networks, and intermediate metabolites can be freely
shared by different reactions. Our approach may be applicable to study
metabolic networks with more complex topologies, or protein signaling networks
which are governed by similar biochemical reactions. Possible implications for
bioinformatic analysis of metabolimic data are discussed.