title: The Color Glass Condensate and Glasma

abstract:
  These two lectures concern the Color Glass Condensate and the Glasma. These
are forms of matter which might be studied in high energy hadronic collisions.
The Color Glass Condensate is high energy density gluonic matter. It
constitutes the part of a hadron wavefunction important for high energy
processes. The Glasma is matter produced from the collision of two high energy
hadrons. Both types of matter are associated with coherent fields. The Color
Glass Condensate is static and related to a hadron wavefunction where the
glasma is transient and evolves quickly after a collision. I present the
properties of such matter, and some aspects of what is known of their
properties.


title: "D-Dimond1", Prototype Antenna RGA-05

abstract:
  At the present thesis a prototype antenna is studied. In chapter 1 the
antenna's geometry is selected with the supervisor's assistance and its
geometrical and dimensional characteristics are outlined. In chapter 2 an
extensive theoretical analysis is carried out and the final mathematical
formulas of the antenna's radiation pattern are extracted. In chapter 3 a
computational study - simulation is carried out utilizing the computer program
RICHWIRE which is capable of dividing the antenna in many segments. The study's
results illustrate the variations of the most important antenna's
characteristic quantities as a function of the number of segments. Finally, a
study of the antenna's behavior as a function of the frequency follows at the
range from 900 to 1300 [MHz]. In chapter 4 the antenna's behavior as a function
of frequency is studied at a more extensive range, approximately from 200 to
2850 [MHz]. In chapter 5 an improvement of the antenna's characteristics is
attempted by modifying its geometrical shape utilizing three distinct
geometrical models. Then follow comparative results between the original and
the improved antenna's dispositions and eventually the final conclusions.


title: Nonlinear N=2 Supersymmetry, Effective Actions and Moduli Stabilization

abstract:
  Nonlinear supersymmetry is used to compute the general form of the effective
D-brane action in type I string theory compactified to four dimensions in the
presence of internal magnetic fields. In particular, the scalar potential
receives three contributions: (1) a nonlinear part of the D-auxiliary
component, associated to the Dirac-Born-Infeld action; (2) a Fayet-Iliopoulos
(FI) D-term with a moduli-dependent coefficient; (3) a D-auxiliary independent
(but moduli dependent) piece from the D-brane tension. Minimization of this
potential leads to three general classes of vacua with moduli stabilization:
(i) supersymmetric vacua allowing in general FI terms to be cancelled by
non-trivial vacuum expectation values (VEV's) of charged scalar fields; (ii)
anti-de Sitter vacua of broken supersymmetry in the presence of a non-critical
dilaton potential that can be tuned at arbitrarily weak string coupling; (iii)
if the dilaton is fixed in a supersymmetric way by three-form fluxes and in the
absence of charged scalar VEV's, one obtains non supersymmetric vacua with
positive vacuum energy.


title:
Spin-triplet p-wave pairing in a 3-orbital model for iron pnictide
  superconductors

abstract:
  We examine the possibility that the superconductivity in the newly discovered
FeAs materials may be caused by the Coulomb interaction between d-electrons of
the iron atoms. We find that when the Hund's rule ferromagnetic interaction is
strong enough, the leading pairing instability is in spin-triplet p-wave
channel in the weak coupling limit. The resulting superconducting gap has nodal
lines on the 3D Fermi surfaces. The k dependent hybridization of several
orbitals around a Fermi pocket is the key for the appearance of the
spin-triplet p-wave pairing.


title: Pseudo Quasi-3 Designs and their Applications to Coding Theory

abstract:
  We define a pseudo quasi-3 design as a symmetric design with the property
that the derived and residual designs with respect to at least one block are
quasi-symmetric. Quasi-symmetric designs can be used to construct optimal self
complementary codes. In this article we give a construction of an infinite
family of pseudo quasi-3 designs whose residual designs allow us to construct a
family of codes with a new parameter set that meet the Grey Rankin bound.


title: Block Spin Density Matrix of the Inhomogeneous AKLT Model

abstract:
  We study the inhomogeneous generalization of a 1-dimensional AKLT spin chain
model. Spins at each lattice site could be different. Under certain conditions,
the ground state of this AKLT model is unique and is described by the
Valence-Bond-Solid (VBS) state. We calculate the density matrix of a contiguous
block of bulk spins in this ground state. The density matrix is independent of
spins outside the block. It is diagonalized and shown to be a projector onto a
subspace. We prove that for large block the density matrix behaves as the
identity in the subspace. The von Neumann entropy coincides with Renyi entropy
and is equal to the saturated value.

categories: quant-ph cond-mat.stat-mech math-ph math.MP


title: The mass of the dominant particle in a fractal universe

abstract:
  An empirically validated, phenomenological model relating the parameters of
an astronomical body to the stochastic fluctuations of its granular components
is generalized in terms of fractal scaling laws. The mass of the particle
constituting the preponderance of the mass of a typical galaxy is determined
from the generalized model as a function of the fractal dimension. For a
fractal dimension between 1 and 3 the mass of the dominant particle in galaxies
is, roughly, between the Planck mass and 1eV. If the dimension is near 2 then
the fractal model is identical to the original stochastic model, and the mass
of the dominant particle must be of order near the nucleon mass. Two additional
expressions for the mass of the dominant particle in the universe are obtained
from basic quantum considerations and from the existence of a cosmological
constant. It follows that the fractal dimension 2 is favored and that the mass
of the dominant particle is proportional to sixth root of the cosmological
constant and of order near the nucleon mass.


title:
The evolution of the colour-magnitude relation and of the star formation
  activity in galaxy clusters since z~0.8

abstract:
  We present recent results on the evolution of the colour-magnitude relation
and of the star formation activity in galaxy clusters since z~0.8. Results are
based on the ESO Distant Cluster Survey (EDisCS) - an ESO large programme aimed
at the study of cluster structure and cluster galaxy evolution over a
significant fraction of cosmic time - and are discussed in the framework of the
current standard paradigm of structure formation.


title: Spectral properties of complex networks

abstract:
  We derive the spectral properties of adjacency matrix of complex networks and
of their Laplacian by the replica method combined with a dynamical population
algorithm. By assuming the order parameter to be a product of Gaussian
distributions, the present theory provides a solution for the non linear
integral equations for the spectra density in random matrix theory of the
spectra of sparse random matrices making a step forward with respect to the
effective medium approximation (EMA) . We extend these results also to weighted
networks with weight-degree correlations


title: Relativistic Nucleus-Nucleus Collisions without Hydrodynamics

abstract:
  The partition function of nonequilibrium distribution which we recently
obtained [arXiv:0802.0259] in the framework of the maximum isotropization model
(MIM) is exploited to extract physical information from experimental data on
the proton rapidity and transverse mass distributions. We propose to partition
all interacting nucleons into ensembles in accordance with the number of
collisions. We analyze experimental rapidity distribution and get the number of
particles in every collision ensemble. We argue that even a large number of
effective nucleon collisions cannot lead to thermalization of nucleon system;
the thermal source which describes the proton distribution in central rapidity
region arises as a result of fast thermalization of the parton degrees of
freedom. The obtained number of nucleons which corresponds to the thermal
contribution is treated as a ``nucleon power'' of the created quark-gluon
plasma in a particular experiment.


title: Three-jet DIS final states from kt-dependent parton showers

abstract:
  Experimental measurements of angular correlations in three-jet final states
have recently been performed in DIS.
  Next-to-leading-order QCD results for these observables are affected by large
theoretical uncertainties in the kinematic region of the data. We discuss the
effects of multiple QCD radiation at higher order using parton-shower methods
based on transverse-momentum dependent parton distributions and matrix
elements. We present Monte-Carlo results for azimuthal two-jet and three-jet
distributions, and discuss the comparison with experimental data.


title:
The Einstein@Home search for periodic gravitational waves in LIGO S4
  data

abstract:
  A search for periodic gravitational waves, from sources such as isolated
rapidly-spinning neutron stars, was carried out using 510 hours of data from
the fourth LIGO science run (S4). The search was for quasi-monochromatic waves
in the frequency range from 50 Hz to 1500 Hz, with a linear frequency drift
f-dot (measured at the solar system barycenter) in the range -f/tau < f-dot <
0.1 f/tau, where the minimum spin-down age tau was 1000 years for signals below
300 Hz and 10000 years above 300 Hz. The main computational work of the search
was distributed over approximately 100000 computers volunteered by the general
public. This large computing power allowed the use of a relatively long
coherent integration time of 30 hours, despite the large parameter space
searched. No statistically significant signals were found. The sensitivity of
the search is estimated, along with the fraction of parameter space that was
vetoed because of contamination by instrumental artifacts. In the 100 Hz to 200
Hz band, more than 90% of sources with dimensionless gravitational wave strain
amplitude greater than 1e-23 would have been detected.


title: Noncoherent Capacity of Underspread Fading Channels

abstract:
  We derive bounds on the noncoherent capacity of wide-sense stationary
uncorrelated scattering (WSSUS) channels that are selective both in time and
frequency, and are underspread, i.e., the product of the channel's delay spread
and Doppler spread is small. For input signals that are peak constrained in
time and frequency, we obtain upper and lower bounds on capacity that are
explicit in the channel's scattering function, are accurate for a large range
of bandwidth and allow to coarsely identify the capacity-optimal bandwidth as a
function of the peak power and the channel's scattering function. We also
obtain a closed-form expression for the first-order Taylor series expansion of
capacity in the limit of large bandwidth, and show that our bounds are tight in
the wideband regime. For input signals that are peak constrained in time only
(and, hence, allowed to be peaky in frequency), we provide upper and lower
bounds on the infinite-bandwidth capacity and find cases when the bounds
coincide and the infinite-bandwidth capacity is characterized exactly. Our
lower bound is closely related to a result by Viterbi (1967).
  The analysis in this paper is based on a discrete-time discrete-frequency
approximation of WSSUS time- and frequency-selective channels. This
discretization explicitly takes into account the underspread property, which is
satisfied by virtually all wireless communication channels.


title: Thermodynamics of resonances and blurred particles

abstract:
  Exact and approximate expressions for thermodynamic characteristics of heated
matter, which consists of particles with finite mass-widths, are constructed.
They are expressed in terms of Fermi/Bose distributions and spectral functions,
rather than in terms of more complicated combinations between real and
imaginary parts of the self-energies of different particle species. Therefore
thermodynamically consistent approximate treatment of systems of particles with
finite mass-widths can be performed, provided spectral functions of particle
species are known. Approximation of the free resonance gas at low densities is
studied. Simple ansatz for the energy dependence of the spectral function is
suggested that allows to fulfill thermodynamical consistency conditions. On
examples it is shown that a simple description of dense systems of interacting
particle species can be constructed, provided some species can be treated in
the quasiparticle approximation and others as particles with widths. The
interaction affects quasiparticle contributions, whereas particles with widths
can be treated as free. Example is considered of a hot gas of heavy fermions
strongly interacting with light bosons, both species with zero chemical
potentials. The density of blurred fermions is dramatically increased for high
temperatures compared to the standard Boltzmann value. The system consists of
boson quasiparticles (with effective masses) interacting with fermion --
antifermion blurs. In thermodynamical values interaction terms partially
compensate each other. Thereby, in case of a very strong coupling between
species thermodynamical quantities of the system, like the energy, pressure and
entropy, prove to be such as for the quasi-ideal gas mixture of quasi-free
fermion blurs and quasi-free bosons.


title: On the matrix elements of dB=0 operators in the heavy meson decay widths

abstract:
  We determine the chiral corrections to the matrix elements of the Delta B=0
four-quark operators which are relevant to the studies of the ratios of
lifetimes of heavy-light mesons as well as to the power corrections to the
inclusive semileptonic heavy-to-light decays. The chiral logarithmic
corrections computed here can be combined with the forthcoming estimates of the
corresponding matrix elements on the lattice to provide the reliable physics
result of the well known bag-parameters B_(1,2) and epsilon_(1,2).


title: Improved Method of the Extensive Air Shower Arrival Direction Estimation

abstract:
  The properties of measuring systems of the Extensive Air Showers arrival
directions (EAS goniometers), consisting of the set of spatially separated
detectors registering the moments of EAS frontal passage, are considered. The
advantage of volumetric goniometers in comparison with the commonly used flat
ones is shown. The proper points selection method for detectors spatial
arranging is suggested, providing the best accessible estimation accuracy
within the given detectors number and installation overall dimensions


title: Biharmonic maps and morphisms from conformal mappings

abstract:
  Inspired by the all-important conformal invariance of harmonic maps on
two-dimensional domains, this article studies the relationship between
biharmonicity and conformality. We first give a characterization of biharmonic
morphisms, analogues of harmonic morphisms investigated by Fuglede and
Ishihara, which, in particular, explicits the conditions required for a
conformal map in dimension four to preserve biharmonicity and helps producing
the first example of a biharmonic morphism which is not a special type of
harmonic morphism. Then, we compute the bitension field of horizontally weakly
conformal maps, which include conformal mappings. This leads to several
examples of proper (i.e. non-harmonic) biharmonic conformal maps, in which
dimension four plays a pivotal role. We also construct a family of Riemannian
submersions which are proper biharmonic maps.


title: Higgs-dependent Yukawa couplings

abstract:
  We consider the possibility that the Yukawa couplings depend on the Higgs
field, with the motivation of generating the fermion mass hierarchy through
appropriate powers of the Higgs vacuum expectation value. This leads to drastic
modifications of the Higgs branching ratios, new Higgs contributions to various
flavor-violating processes, and observable rates for the top quark decay t->
hc. The underlying flavor dynamics must necessarily appear at the TeV scale and
is within the reach of the LHC.


title: Thermodynamic Properties of electrically modulated monolayer Graphene

abstract:
  Theoretical investigation of thermodynamic properties of electrically
modulated monolayer graphene in the presence of a perpendicular magnetic field
B is presented.This work is aimed at determining the modulation induced effects
on the thermodynamic properties of electrically modulated graphene.The results
obtained are compared with those of the conventional 2DEG. The one-dimensional
periodic potential due to electric modulation lifts the degeneracy of the
Landau Levels and converts them into bands whose width oscillates as a function
of B. We find Weiss type oscillations for small values of B and dHvA type
oscillations at larger values values of $B$. We find that the modulation
induced effects on the thermodynamic properties are enhanced and less damped
with temperature in graphene compared with conventional 2DEG system.


title: Density Matrix Renormalization Group Lagrangians

abstract:
  We introduce a Lagrangian formulation of the Density Matrix Renormalization
Group (DMRG). We present Lagrangians which when minimised yield the optimal
DMRG wavefunction in a variational sense, both within the general matrix
product ansatz, as well as within the canonical form of the matrix product that
is constructed within the DMRG sweep algorithm. Some of the results obtained
are similar to elementary expressions in Hartree-Fock theory, and we draw
attention to such analogies. The Lagrangians introduced here will be useful in
developing theories of analytic response and derivatives in the DMRG.


title: Supermassive Black Holes and Their Environments

abstract:
  We make use of the first high--resolution hydrodynamic simulations of
structure formation which self-consistently follows the build up of
supermassive black holes introduced in Di Matteo et al. (2007) to investigate
the relation between black holes (BH), host halo and large--scale environment.
There are well--defined relations between halo and black hole masses and
between the activities of galactic nuclei and halo masses at low redshifts. A
large fraction of black holes forms anti--hierarchically, with a higher ratio
of black hole to halo mass at high than at low redshifts. At $z=1$, we predict
group environments (regions of enhanced local density) to contain the highest
mass and most active (albeit with a large scatter) BHs while the rest of the BH
population to be spread over all densities from groups to filaments and voids.
Density dependencies are more pronounced at high rather than low redshift.
These results are consistent with the idea that gas rich mergers are likely the
main regulator of quasar activity. We find star formation to be a somewhat
stronger and tighter function of local density than BH activity, indicating
some difference in the triggering of the latter versus the former. There exists
a large number of low--mass black holes, growing slowly predominantly through
accretion, which extends all the way into the most underdense regions, i.e. in
voids.


title: Stable two--brane models with bulk tachyon matter

abstract:
  We explore the possibility of constructing stable, warped two--brane models
which solve the hierarchy problem, with a bulk non--canonical scalar field
(tachyon matter) as the source term in the action. Among our examples are two
models--one with a warp factor (denoted as $e^{-2f(\sigma)}$) which differs
from that of the standard Randall--Sundrum by the addition of a quadratic piece
in the $f(\sigma)$ and another, where the warping is super-exponential. We
investigate the issue of resolution of hierarchy and perform a stability
analysis by obtaining the effective inter-brane potentials, in each case. Our
analysis reveals that there does exist stable values of the modulus consistent
with hierarchy resolution in both the models. Thus, these models, in which the
bulk scalar field generates the geometry and also ensures stability, provide
viable alternatives to the standard Randall--Sundrum two-brane scenario.


title: Measure and integral with purely ordinal scales

abstract:
  We develop a purely ordinal model for aggregation functionals for lattice
valued functions, comprising as special cases quantiles, the Ky Fan metric and
the Sugeno integral. For modeling findings of psychological experiments like
the reflection effect in decision behaviour under risk or uncertainty, we
introduce reflection lattices. These are complete linear lattices endowed with
an order reversing bijection like the reflection at 0 on the real interval
$[-1,1]$. Mathematically we investigate the lattice of non-void intervals in a
complete linear lattice, then the class of monotone interval-valued functions
and their inner product.


title:
Trapped Phase-Segregated Bose-Fermi Mixtures and their Collective
  Excitations

abstract:
  Recent progress in the field of ultracold gases has allowed the creation of
phase-segregated Bose-Fermi systems. We present a theoretical study of their
collective excitations at zero temperature. As the fraction of fermion to boson
particle number increases, the collective mode frequencies take values between
those for a fully bosonic and those for a fully fermionic cloud, with damping
in the intermediate region. This damping is caused by fermions which are
resonantly driven at the interface.


title: The Symmetric Sugeno Integral

abstract:
  We propose an extension of the Sugeno integral for negative numbers, in the
spirit of the symmetric extension of Choquet integral, also called \Sipos\
integral. Our framework is purely ordinal, since the Sugeno integral has its
interest when the underlying structure is ordinal. We begin by defining
negative numbers on a linearly ordered set, and we endow this new structure
with a suitable algebra, very close to the ring of real numbers. In a second
step, we introduce the M\"obius transform on this new structure. Lastly, we
define the symmetric Sugeno integral, and show its similarity with the
symmetric Choquet integral.


title:
Lower bounds of martingale measure densities in the
  Dalang-Morton-Willinger theorem

abstract:
  For a $d$-dimensional stochastic process $(S_n)_{n=0}^N$ we obtain criteria
for the existence of an equivalent martingale measure, whose density $z$, up to
a normalizing constant, is bounded from below by a given random variable $f$.
We consider the case of one-period model (N=1) under the assumptions $S\in
L^p$; $f,z\in L^q$, $1/p+1/q=1$, where $p\in [1,\infty]$, and the case of
$N$-period model for $p=\infty$. The mentioned criteria are expressed in terms
of the conditional distributions of the increments of $S$, as well as in terms
of the boundedness from above of an utility function related to some optimal
investment problem under the loss constraints. Several examples are presented.


title:
The Choquet integral for the aggregation of interval scales in
  multicriteria decision making

abstract:
  This paper addresses the question of which models fit with information
concerning the preferences of the decision maker over each attribute, and his
preferences about aggregation of criteria (interacting criteria). We show that
the conditions induced by these information plus some intuitive conditions lead
to a unique possible aggregation operator: the Choquet integral.


title: Fine Gradings on the exceptional Lie algebra $\mathfrak d_4$

abstract:
  We describe all the fine group gradings, up to equivalence, on the Lie
algebra $\mathfrak d_4$. This problem is equivalent to finding the maximal
abelian diagonalizable subgroups of the automorphism group of $\mathfrak d_4$.
We prove that there are fourteen by using two different viewpoints. The first
approach is computational: we get a full description of the gradings by using a
particular implementation of the automorphism group of the Dynkin diagram of
$\mathfrak d_4$ and some algebraic groups stuff. The second approach, more
qualitative, emphasizes some algebraic aspects, as triality, and it is mostly
devoted to gradings involving the outer automorphisms of order three.


title:
Attainment of Gigavolt Potentials by Fluid Dynamic Suppression of the
  Stepped Leader its Significance for Thermonuclear Ignition

abstract:
  It is proposed to levitate a conducting sphere in a high pressure Taylor flow
and to charge it up to gigavolt potentials, either mechanically as in a Van de
Graaff electrostatic generator, or inductively by a rising magnetic field. If
the Taylor flow is sufficiently fast, it should overcome the electric pressure
and breakdown by stepped leader formation, leading to the maximum attainable
voltage by the Paschen law. Discharging the electrostatically stored energy can
be done by controlled breakdown. With gigajoule energies stored and released in
about 10^-8 sec, this implies and electric pulse power of the order 10^17 Watt,
opening the prospect of large driver energies for thermonuclear ignition.


title: Vortex-nucleus interaction in the inner crust of neutron stars

abstract:
  The structure of a vortex in the inner crust of neutron stars is calculated
within the framework of quantum mean field theory taking into account the
interaction with the nuclei composing the Coulomb lattice. Making use of the
results obtained with different nuclear interactions, the pinning energy,
relevant in the study of glitches, is worked out. Quantal size and density
dependent effects are found to be important.


title:
The qWR star HD 45166. II. Fundamental stellar parameters and evidence
  of a latitude-dependent wind

abstract:
  The enigmatic object HD 45166 is a qWR star in a binary system with an
orbital period of 1.596 day, and presents a rich emission-line spectrum in
addition to absorption lines from the companion star (B7 V). As the system
inclination is very small (i=0.77 +- 0.09 deg), HD 45166 is an ideal laboratory
for wind-structure studies. The goal of the present paper is to determine the
fundamental stellar and wind parameters of the qWR star. A radiative transfer
model for the wind and photosphere of the qWR star was calculated using the
non-LTE code CMFGEN. The wind asymmetry was also analyzed using a
recently-developed version of CMFGEN to compute the emerging spectrum in
two-dimensional geometry. The temporal-variance spectrum (TVS) was calculated
for studying the line-profile variations. Abundances, stellar and wind
parameters of the qWR star were obtained. The qWR star has an effective
temperature of Teff=50000 +- 2000 K, a luminosity of log(L/Lsun)=3.75 +- 0.08,
and a corresponding photospheric radius of Rphot=1.00 Rsun. The star is
helium-rich (N(H)/N(He) = 2.0), while the CNO abundances are anomalous when
compared either to solar values, to planetary nebulae, or to WR stars. The
mass-loss rate is Mdot = 2.2 . 10^{-7} Msun/yr, and the wind terminal velocity
is vinf=425 km/s. The comparison between the observed line profiles and models
computed under different latitude-dependent wind densities strongly suggests
the presence of an oblate wind density enhancement, with a density contrast of
at least 8:1 from equator to pole. If a high velocity polar wind is present
(~1200 km/s), the minimum density contrast is reduced to 4:1. The wind
parameters determined are unusual when compared to O-type stars or to typical
WR stars. (abridged)


title:
One-dimensional semiconductor in a polar solvent: Solvation and
  low-frequency dynamics of an excess charge carrier

abstract:
  Due to solvation, excess charge carriers on 1d semiconductor nanostructures
immersed in polar solvents undergo self-localization into polaronic states.
Using a simplified theoretical model for small-diameter structures, we study
low-frequency properties of resulting 1d adiabatic polarons. The combined
microscopic dynamics of the electronic charge density and the solvent leads to
macroscopic Langevin dynamics of a polaron and to the appearance of local
dielectric relaxation modes. Polaron mobility is evaluated as a function of
system parameters. Numerical estimates indicate that the solvated carriers can
have mobilities orders of magnitude lower than the intrinsic values.


title: Dynamics of condensation in growing complex networks

abstract:
  A condensation transition was predicted for growing technological networks
evolving by preferential attachment and competing quality of their nodes, as
described by the fitness model.
  When this condensation occurs a node acquires a finite fraction of all the
links of the network. Earlier studies based on steady state degree distribution
and on the mapping to Bose-Einstein condensation, were able to identify the
critical point. Here we characterize the dynamics of condensation and we
present evidence that below the condensation temperature there is a slow down
of the dynamics and that a single node (not necessarily the best node in the
network) emerges as the winner for very long times. The characteristic time t*
at which this phenomenon occurs diverges both at the critical point and at $T
-> 0$ when new links are attached deterministically to the highest quality node
of the network.


title: New supersymmetric flux vacua with intermediate SU(2) structure

abstract:
  We find new supersymmetric four-dimensional Minkowski flux vacua of type II
string theory on nilmanifolds and solvmanifolds. We extend the results of M.
Grana, R. Minasian, M. Petrini, and A. Tomasiello to the case of intermediate
SU(2) structures (the two internal supersymmetry parameters are neither
parallel nor orthogonal). As pointed out recently by P. Koerber and D. Tsimpis,
intermediate SU(2) structures are possible when one considers "mixed"
orientifold projection conditions. To find our vacua, we rewrite these
projection conditions in a more tractable way by introducing new variables: the
projection basis. In these variables, the SUSY conditions become also much
simpler to solve, and we find three new vacua. In addition, we find that these
variables correspond to the SU(2) structure appearing with the dielectric pure
spinors, objects introduced and discussed by R. Minasian, M. Petrini, A.
Zaffaroni, and N. Halmagyi, A. Tomasiello, in the AdS/CFT context. Besides, our
solutions provide some intuition on what a dynamical SU(3) x SU(3) structure
solution could look like.


title:
Collision probabilities in the rarefaction fan of asymmetric exclusion
  processes

abstract:
  We consider the one-dimensional asymmetric simple exclusion process (ASEP) in
which particles jump to the right at rate $p\in(1/2,1]$ and to the left at rate
$1-p$, interacting by exclusion. In the initial state there is a finite region
such that to the left of this region all sites are occupied and to the right of
it all sites are empty. Under this initial state, the hydrodynamical limit of
the process converges to the rarefaction fan of the associated Burgers
equation. In particular suppose that the initial state has first-class
particles to the left of the origin, second-class particles at sites 0 and 1,
and holes to the right of site 1. We show that the probability that the two
second-class particles eventually collide is $(1+p)/3p$, where a_collision_
occurs when one of the particles attempts to jump over the other. This also
corresponds to the probability that two ASEP processes, started from
appropriate initial states and coupled using the so-called "basic coupling",
eventually reach the same state. We give various other results about the
behaviour of second-class particles in the ASEP. In the totally asymmetric case
($p=1$) we explain a further representation in terms of a multi-type particle
system, and also use the collision result to derive the probability of
coexistence of both clusters in a two-type version of the corner growth model.


title: The cosmic variance of Omega

abstract:
  How much can we know about our Universe? All of our observations are
restricted to a finite volume, and therefore our estimates of presumably global
cosmological parameters are necessarily based on incomplete information. Even
assuming that the Standard Model of cosmology is correct, this means that some
cosmological questions may be unanswerable. For example, is the curvature
parameter Omega_K positive, negative, or identically zero? If its magnitude is
sufficiently small, then due to cosmic variance no causal observation can ever
answer that question. In this article, we first describe the gauge problems
associated with defining the cosmic variance of cosmological parameters, then
describe a solution involving the use of parameters defined on the surface of
last scattering, and finally calculate the statistical variance of ideal
measurements of the matter, radiation, and curvature density parameters. We
find that Omega_K cannot be measured to better than about 1.5x10^(-5) (1
sigma), and that this limit has already begun to decrease due to the flattening
effect of dark energy. Proposed 21 cm hydrogen experiments, for example, make
this limit more than just a theoretical curiosity.


title: Instantons, Fermions and Chern-Simons Terms

abstract:
  In five spacetime dimensions, instantons are finite energy, solitonic
particles. We describe the dynamics of these objects in the presence of a
Chern-Simons interaction. For U(N) instantons, we show that the 5d Chern-Simons
term induces a corresponding Chern-Simons term in the ADHM quantum mechanics.
For SU(N) instantons, we provide a description in terms of geodesic motion on
the instanton moduli space, modified by the presence of a magnetic field. We
show that this magnetic field is equal to the first Chern character of an index
bundle. All of these results are derived by a simple method which follows the
fate of zero modes as fermions are introduced, made heavy, and subsequently
integrated out.


title: One-loop Partition Functions of 3D Gravity

abstract:
  We consider the one-loop partition function of free quantum field theory in
locally Anti-de Sitter space-times. In three dimensions, the one loop
determinants for scalar, gauge and graviton excitations are computed explicitly
using heat kernel techniques. We obtain precisely the result anticipated by
Brown and Henneaux: the partition function includes a sum over "boundary
excitations" of AdS3, which are the Virasoro descendants of empty Anti-de
Sitter space. This result also allows us to compute the one-loop corrections to
the Euclidean action of the BTZ black hole as well its higher genus
generalizations.


title:
Inverse Compton Origin of the Hard X-Ray and Soft Gamma-Ray Emission
  from the Galactic Ridge

abstract:
  A recent re-determination of the non-thermal component of the hard X-ray to
soft gamma-ray emission from the Galactic ridge, using the SPI instrument on
the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) Observatory, is
shown to be well reproduced as inverse-Compton emission from the interstellar
medium. Both cosmic-ray primary electrons and secondary electrons and positrons
contribute to the emission. The prediction uses the GALPROP model and includes
a new calculation of the interstellar radiation field. This may solve a
long-standing mystery of the origin of this emission, and potentially opens a
new window on Galactic cosmic rays.


title: Analytical solutions of the Bohr Hamiltonian with the Morse potential

abstract:
  Analytical solutions of the Bohr Hamiltonian are obtained in the
$\gamma$-unstable case, as well as in an exactly separable rotational case with
$\gamma\approx 0$, called the exactly separable Morse (ES-M) solution. Closed
expressions for the energy eigenvalues are obtained through the Asymptotic
Iteration Method (AIM), the effectiveness of which is demonstrated by solving
the relevant Bohr equations for the Davidson and Kratzer potentials. All medium
mass and heavy nuclei with known $\beta_1$ and $\gamma_1$ bandheads have been
fitted by using the two-parameter $\gamma$-unstable solution for transitional
nuclei and the three-parameter ES-M for rotational ones. It is shown that
bandheads and energy spacings within the bands are well reproduced for more
than 50 nuclei in each case.


title:
Theory of Direct Scattering, Trapping and Desorption in Atom-Surface
  Collisions

abstract:
  When gas atoms or molecules collide with clean and ordered surfaces, under
many circumstances the energy-resolved scattering spectra exhibit two clearly
distinct features due to direct scattering and to trapping in the physisorption
well with subsequent desorption. James Clerk Maxwell is credited with being the
first to describe this situation by invoking the simple assumption that when an
impinging gas beam is scattered from a surface it can be divided into a part
that exchanges no energy and specularly reflects and another part that
equilibrates or accommodates completely and then desorbs with an equilibrium
distribution. In this paper a scattering theory is developed, using an
iterative algorithm and classical mechanics for the collision process, that
describes both direct scattering and trapping-desorption of the incident beam.
The initially trapped fraction of particles can be followed as they continue to
make further interactions with the surface until they are all eventually
promoted back into the positive energy continuum and leave the surface region.
Consequently, this theory allows a rigorous test of the Maxwell assumption and
determines the conditions under which it is valid. The theory also gives
quantitative explanations of recent experimental measurements which exhibit
both a direct scattering contribution and a trapping-desorption fraction in the
energy-resolved spectra.


title: Phutball is PSPACE-hard

abstract:
  We consider the $n\times n$ game of Phutball. It is shown that, given an
arbitrary position of stones on the board, it is a PSPACE-hard problem to
determine whether the specified player can win the game, regardless of the
opponent's choices made during the game.


title: Graphene Segregated on Ni surfaces and Transferred to Insulators

abstract:
  We report an approach to synthesize high quality graphene by surface
segregation and substrate transfer. Graphene was segregated from Ni surface
under the ambient pressure by dissolving carbon in Ni at high temperatures
followed by cooling down with various rates. Different cooling rates led to
different segregation behaviors, strongly affecting the thickness and quality
of the graphene films. Electron microscopy and Raman spectroscopy indicated
that the graphene films synthesized with medium cooling rates have high quality
crystalline structure and well-controlled thicknesses. The graphene films were
transferred to insulating substrates by wet etching and found to maintain their
high quality.


title: Octet baryon magnetic moments from QCD sum rules

abstract:
  A comprehensive study is made for the magnetic moments of octet baryons in
the method of QCD sum rules. A complete set of QCD sum rules is derived using
the external field method and generalized interpolating fields. For each
member, three sum rules are constructed from three independent tensor
structures. They are analyzed in conjunction with the corresponding mass sum
rules. The performance of each of the sum rules is examined using the criteria
of OPE convergence and ground-state dominance, along with the role of the
transitions in intermediate states. Individual contributions from the u, d and
s quarks are isolated and their implications in the underlying dynamics are
explored. Valid sum rules are identified and their predictions are obtained.
The results are compared with experiment and previous calculations.


title: On convex functions and the finite element method

abstract:
  Many problems of theoretical and practical interest involve finding a convex
or concave function. For instance, optimization problems such as finding the
projection on the convex functions in $H^k(\Omega)$, or some problems in
economics.
  In the continuous setting and assuming smoothness, the convexity constraints
may be given locally by asking the Hessian matrix to be positive semidefinite,
but in making discrete approximations two difficulties arise: the continuous
solutions may be not smooth, and an adequate discrete version of the Hessian
must be given.
  In this paper we propose a finite element description of the Hessian, and
prove convergence under very general conditions, even when the continuous
solution is not smooth, working on any dimension, and requiring a linear number
of constraints in the number of nodes.
  Using semidefinite programming codes, we show concrete examples of
approximations to optimization problems.


title: Large semilattices of breadth three

abstract:
  A 1984 problem of S.Z. Ditor asks whether there exists a lattice of
cardinality aleph two, with zero, in which every principal ideal is finite and
every element has at most three lower covers. We prove that the existence of
such a lattice follows from either one of two axioms that are known to be
independent of ZFC, namely (1) Martin's Axiom restricted to collections of
aleph one dense subsets in posets of precaliber aleph one, (2) the existence of
a gap-1 morass. In particular, the existence of such a lattice is consistent
with ZFC, while the non-existence of such a lattice implies that omega two is
inaccessible in the constructible universe. We also prove that for each regular
uncountable cardinal $\kappa$ and each positive integer n, there exists a
join-semilattice L with zero, of cardinality $\kappa^{+n}$ and breadth n+1, in
which every principal ideal has less than $\kappa$ elements.


title:
Dynamics of Cryogenic Jets: Non-Rayleigh Breakup and Onset of
  Nonaxisymmetric Motions

abstract:
  We report development of generators for periodic, satellite-free fluxes of
mono-disperse drops with diameters down to 10 mikrometers from cryogenic
liquids like H_2, N_2, Ar and Xe (and, as reference fluid, water). While the
breakup of water jets can well be described by Rayleigh's linear theory, we
find jet regimes for H_2 and N_2 which reveal deviations from this behavior.
Thus, Rayleigh's theory is inappropriate for thin jets that exchange energy
and/or mass with the surrounding medium. Moreover, at high evaporation rates,
axial symmetry of the dynamics is lost. When the drops pass into vacuum, frozen
pellets form due to surface evaporation. The narrow width of the pellet flux
paves the way towards various industrial and scientific applications.


title:
Repeated Interaction Quantum Systems: van Hove Limits and Asymptotic
  States

abstract:
  We establish the existence of two weak coupling regime effective dynamics for
an open quantum system of repeated interactions (vanishing strength and
individual interaction duration, respectively). This generalizes known results
in that the von Neumann algebras describing the system and the chain element
may not be of finite type. Then (but now assuming that the small system is of
finite type), we prove that both effective dynamics capture the long-term
behaviour of the system: existence of a unique asymptotic state for them
implies the same property for the respective exact dynamics--provided that the
perturbation parameter is sufficiently small. The zero-th order term in a power
series expansion in the perturbation parameter of such an asymptotic state is
given by the asymptotic state of the effective dynamics. We conclude by working
out the case in which the small system and the chain element are spins.


title: On relating multiple M2 and D2-branes

abstract:
  Due to the difficulties of finding superconformal Lagrangian theories for
multiple M2-branes, we will in this paper instead focus on the field equations.
By relaxing the requirement of a Lagrangian formulation we can explore the
possibility of having structure constants $f^{ABC}{}_D$ satisfying the
fundamental identity but which are not totally antisymmetric. We exemplify this
discussion by making use of an explicit choice of a non-antisymmetric
$f^{ABC}{}_D$ constructed from the Lie algebra structure constants $f^{ab}{}_c$
of an arbitrary gauge group. Although this choice of $f^{ABC}{}_D$ does not
admit an obvious Lagrangian description, it does reproduce the correct SYM
theory for a stack of $N$ D2-branes to leading order in $g_{YM}^{-1}$ upon
reduction and, moreover, it sheds new light on the centre of mass coordinates
for multiple M2-branes.


title:
Solitary waves for linearly coupled nonlinear Schrodinger equations with
  inhomogeneous coefficients

abstract:
  Motivated by the study of matter waves in Bose-Einstein condensates and
coupled nonlinear optical systems, we study a system of two coupled nonlinear
Schrodinger equations with inhomogeneous parameters, including a linear
coupling. For that system we prove the existence of two different kinds of
homoclinic solutions to the origin describing solitary waves of physical
relevance. We use a Krasnoselskii fixed point theorem together with a suitable
compactness criterion.


title:
Entanglement-Seeded-Dual Optical Parametric Amplification: Applications
  to Quantum Communication, Imaging, and Metrology

abstract:
  The study of optical parametric amplifiers (OPAs) has been successful in
describing and creating nonclassical light for use in fields such as quantum
metrology and quantum lithography [Agarwal, et al., J. Opt. Soc. Am. B, 24, 2
(2007)]. In this paper we present the theory of an OPA scheme utilizing an
entangled state input. The scheme involves two identical OPAs seeded with the
maximally path-entangled N00N state (|2,0>+|0,2>)/sqrt{2}. The stimulated
amplification results in output state probability amplitudes that have a
dependence on the number of photons in each mode, which differs greatly from
two-mode squeezed vacuum. The output contains a family of entangled states
directly applicable to quantum key distribution. Specific output states allow
for the heralded creation of N=4 N00N states, which may be used for quantum
lithography, to write sub-Rayleigh fringe patterns, and for quantum
interferometry, to achieve Heisenberg-limited phase measurement sensitivity.


title: Scalar Perturbations on Lemaitre-Tolman-Bondi Spacetimes

abstract:
  In recent years there has been growing interest in verifying the
horizon-scale homogeneity of the Universe that follows from applying the
Copernican Principle to the observed isotropy. This program has been stimulated
by the discovery that a very large void, centred near us, can explain supernova
luminosity distance measurements without dark energy. It is crucial to confront
such models with as wide a variety of data as possible. With this application
in mind, I develop the relativistic theory of linear scalar perturbations on
spherically symmetric dust (Lemaitre-Tolman-Bondi) spacetimes, using the
covariant 1 + 1 + 2 formalism. I show that the evolution of perturbations is
determined by a small set of new linear transfer functions. If decaying modes
are ignored (to be consistent with the standard inflationary paradigm), the
standard techniques of perturbation theory on homogeneous backgrounds, such as
harmonic expansion, can be applied, and results closely paralleling those of
familiar cosmological perturbation theory can be obtained.


title: Prediciendo el generador cuadratico (in Spanish)

abstract:
  Let p be a prime and a, c be integers such that a<>0 mod p. The quadratic
generator is a sequence (u_n) of pseudorandom numbers defined by
u_{n+1}=a*(u_n)^2+c mod p. In this article we probe that if we know
sufficiently many of the most significant bits of two consecutive values u_n,
u_{n+1}, then we can compute the seed u_0 except for a small number of
exceptional values.
  -----
  Sean p un primo, a y c enteros tales que a<>0 mod p. El generador cuadratico
es una sucesion (u_n) de numeros pseudoaleatorios definidos por la relacion
u_{n+1}=a*(u_n)^2+c mod p. En este trabajo demostramos que si conocemos un
numero suficientemente grande de los bits mas significativos para dos valores
consecutivos u_n, u_{n+1}, entonces podemos descubrir en tiempo polinomial la
semilla u_0, excepto para un conjunto pequeno de valores excepcionales.


title:
Nonlinear corrections to the cosmological matter power spectrum and
  scale-dependent galaxy bias: implications for parameter estimation

abstract:
  We explore and compare the performances of two nonlinear correction and
scale-dependent biasing models for the extraction of cosmological information
from galaxy power spectrum data, especially in the context of beyond-LCDM
cosmologies. The first model is the well known Q model, first applied in the
analysis of 2dFGRS data. The second, the P model, is inspired by the halo
model, in which nonlinear evolution and scale-dependent biasing are
encapsulated in a single non-Poisson shot noise term. We find that while both
models perform equally well in providing adequate correction for a range of
galaxy clustering data in standard LCDM cosmology and in extensions with
massive neutrinos, the Q model can give unphysical results in cosmologies
containing a subdominant free-streaming dark matter whose temperature depends
on the particle mass, e.g., relic thermal axions, unless a suitable prior is
imposed on the correction parameter. This last case also exposes the danger of
analytic marginalisation, a technique sometimes used in the marginalisation of
nuisance parameters. In contrast, the P model suffers no undesirable effects,
and is the recommended nonlinear correction model also because of its physical
transparency.


title: Embedded Oscillating Starless Cores

abstract:
  In a previous paper we demonstrated that non-radial hydrodynamic oscillations
of a thermally-supported (Bonnor-Ebert) sphere embedded in a low-density,
high-temperature medium persist for many periods. The predicted column density
variations and molecular spectral line profiles are similar to those observed
in the Bok globule B68 suggesting that the motions in some starless cores may
be oscillating perturbations on a thermally supported equilibrium structure.
Such oscillations can produce molecular line maps which mimic rotation,
collapse or expansion, and thus could make determining the dynamical state from
such observations alone difficult.
  However, while B68 is embedded in a very hot, low-density medium, many
starless cores are not, having interior/exterior density contrasts closer to
unity. In this paper we investigate the oscillation damping rate as a function
of the exterior density. For concreteness we use the same interior model
employed in Broderick et al. (2007), with varying models for the exterior gas.
We also develop a simple analytical formalism, based upon the linear
perturbation analysis of the oscillations, which predicts the contribution to
the damping rates due to the excitation of sound waves in the external medium.
We find that the damping rate of oscillations on globules in dense molecular
environments is always many periods, corresponding to hundreds of thousands of
years, and persisting over the inferred lifetimes of the globules.


title: Multidimensional Version of Lagrange's Problem on Mean Motion

abstract:
  The famous mean motion problem which goes back to Lagrange as follows: to
prove that any exponential polynomial with exponents on the imaginary axis has
an average speed for the amplitude, whenever the variable moves along a
horizontal line. It was completely proved by B. Jessen and H. Tornehave in Acta
Math.77, 1945. Here we give its multidimensional version.


title: The Puzzling White Dwarf Cooling Sequence in NGC6791: A Simple Solution

abstract:
  In this paper we demonstrate that the puzzling bright peak in the luminosity
function of the white dwarf (WD) cooling sequence of NGC6791 can be naturally
accounted for if ~34% of the observed WDs are WD+WD binary systems.


title: Theory of magnetic excitations in iron-based layered superconductors

abstract:
  Based on the effective four-band model we analyze the spin response in the
normal and superconducting states of the Fe-pnictide superconductors. While the
normal state spin excitations are dominated by the continuum of the
interorbital antiferromagnetic fluctuations and the intraband spin density wave
fluctuations, the unconventional superconductivity yields different feedback.
The resonance peak in form of the well-defined spin exciton occurs {\it only}
for the interband scattering at the antiferromagnetic momentum ${\bf Q}_{AFM}$
for the $s_\pm$ (extended s-wave) superconducting order parameter and it
disappears rapidly for ${\bf q} < {\bf Q}_{AFM}$. The resonance feature is
extremely weak for the $d_{x^2 -y^2}$-wave order parameter due to specific
Fermi surface topology of these compounds. The essential difference between
$s_\pm$-wave and $d_{x^2 -y^2}$-wave symmetries for the magnetic excitations
can be used for experimental determination of the superconducting wave function
symmetry.


title: Destruction of Neel order in the cuprates by electron-doping

abstract:
  Motivated by the evidence in PCCO and NCCO of a magnetic quantum critical
point at which Neel order is destroyed, we study the evolution with doping of
the T=0 quantum phases of the electron doped cuprates. At low doping, there is
a metallic Neel state with small electron Fermi pockets, and this yields a
fully gapped d_{x^2-y^2} superconductor with co-existing Neel order at low
temperatures. We analyze the routes by which the spin-rotation symmetry can be
restored in these metallic and superconducting states. In the metal, the loss
of Neel order leads to a topologically ordered `doublon metal' across a
deconfined critical point with global O(4) symmetry. In the superconductor, in
addition to the conventional spin density wave transition, we find a variety of
unconventional possibilities, including transitions to a nematic superconductor
and to valence bond supersolids. Measurements of the spin correlation length
and of the anomalous dimension of the Neel order by neutron scattering or NMR
should discriminate these unconventional transitions from spin density wave
theory.


title:
A large-scale optical-near infrared survey for brown dwarfs and very
  low-mass stars in the Orion OB1 association

abstract:
  We report the initial results of a large-scale optical-near infrared survey
to extend the known young population of the entire Orion star-forming region
down to the substellar domain. Using deep optical I-band photometry and data
from the 2MASS survey, we selected candidates across ~14.8 deg^2 in the ~8 Myr
old Ori OB1a subassociation and over ~6.7 deg^2 in the Ori OB1b subassociation
(age ~3), with completeness down to 0.05Mo and 0.072Mo respectively. We
obtained low resolution optical spectra for a subsample of 4 candidates in Ori
OB1a and 26 in Ori OB1b; as a result we confirmed 3 new members in Ori OB1a,
one of which is substellar, and 19 new members in Ori OB1b, out of which 7 are
at the substellar limit and 5 are substellar. We looked into the presence of
accretion signatures by measuring the strength of the Ha line in emission.
Accordingly, we classified the new members as having Classical T-Tauri star
(CTTS) or Weak Lined T Tauri star-like (WTTS) nature. We found that all the new
members confirmed in Ori OB1a are WTTSs, while 39 +25/-22 % of the new members
in Ori OB1b exhibit CTTS-like behavior, suggestive of ongoing accretion from a
circum(sub)stellar disk. Additionally we found that none of the members
confirmed in OB1a show near-IR color excess while 38 +26/-21 % of OB1b members
show H-K color excess. These results are consistent with recent findings for
low mass young stars in Orion OB1. The similarity in CTTS-like properties and
near-IR excess across the substellar boundary gives support to the idea of a
common formation mechanism for low mass stars and at least the most massive
brown dwarfs. Finally, we remark the discovery of two new members classified as
CTTSs, both exhibiting W(Ha) < -140 A, suggesting significant ongoing
accretion.


title: Non-hyperbolic ergodic measures for non-hyperbolic homoclinic classes

abstract:
  We prove that for a generic $C^1$-diffeomorphism existence of a homoclinic
class with periodic saddles of different indices (dimension of the unstable
bundle) implies existence an invariant ergodic non-hyperbolic (one of the
Lyapunov exponents is equal to zero) measure of $f$.


title:
Chern-Simons Modified Gravity as a Torsion Theory and its Interaction
  with Fermions

abstract:
  We study the tetrad formulation of Chern-Simons (CS) modified gravity, which
adds a Pontryagin term to the Einstein-Hilbert action with a
spacetime-dependent coupling field. We first verify that CS modified gravity
leads to a theory with torsion, where this tensor is given by an antisymmetric
product of the Riemann tensor and derivatives of the CS coupling. We then
calculate the torsion in the far field of a weakly gravitating source within
the parameterized post-Newtonian formalism, and specialize the result to Earth.
We find that CS torsion vanishes only if the coupling vanishes, thus
generically leading to a modification of gyroscopic precession, irrespective of
the coupling choice. Perhaps most interestingly, we couple fermions to CS
modified gravity via the standard Dirac action and find that these further
correct the torsion tensor. Such a correction leads to two new results: (i) a
generic enhancement of CS modified gravity by the Dirac equation and axial
fermion currents; (ii) a new two-fermion interactions, mediated by an axial
current and the CS correction. We conclude with a discussion of the
consequences of these results in particle detectors and realistic astrophysical
systems.


title: Parabolicity of maximal surfaces in Lorentzian product spaces

abstract:
  In this paper we establish some parabolicity criteria for maximal surfaces
immersed into a Lorentzian product space of the form $M^2\times\mathbb{R}_1$,
where $M^2$ is a connected Riemannian surface with non-negative Gaussian
curvature and $M^2\times\mathbb{R}_1$ is endowed with the Lorentzian product
metric $<,>=<,>_M-dt^2$. In particular, and as an application of our main
result, we deduce that every maximal graph over a starlike domain
$\Omega\subseteq M$ is parabolic. This allows us to give an alternative proof
of the non-parametric version of the Calabi-Bernstein result for entire maximal
graphs in $M^2\times\mathbb{R}_1$.


title: On the Binary Nature of Dust-encircled BD+20 307

abstract:
  Three epochs of high resolution spectra of the star BD+20 307 show that it is
a short period (~3.5 day) spectroscopic binary of two nearly identical stars.
Surprisingly, the two stars, though differing in effective temperature by only
~250 K and having a mass ratio of 0.91, show very different Li line equivalent
widths. A Li 6707 Angstrom line is only detected from the primary star, and it
is weak. This star is therefore likely to be older than 1 Gyr. If so, the large
amount of hot circumbinary dust must be from a very large and recent, but very
late evolutionarily, collision of planetesimals.


title:
Transverse Energy Measurement and Fluctuation Studies in
  Ultra-Relativistic Heavy Ion Collisions

abstract:
  Transverse energy ($E_T$) has been measured with both of it's components,
namely hadronic ($E_T^{had}$) and electromagnetic ($E_T^{em}$) at mid-rapidity,
for 62.4 GeV Au+Au collisions by the STAR experiment. In the common phase space
of TPC and BEMC ($0 < \eta < 1$ and full $\phi$), we have obtained $E_T^{had}$
from the TPC reconstructed tracks and $E_T^{em}$ from the BEMC tower hits after
correcting for the hadronic contaminations in the calorimeter. The centrality
behavior of $<dE_T/d\eta>/(0.5 N_{part})$ and the excitation function of
$<dE_T/dy>/(0.5 N_{part})$ has been compared with the final state gluon
saturation model (EKRT) along with similar measurements from SPS to RHIC. The
most striking feature is the observation of a nearly constant value of
$E_T/N_{ch} \sim 0.8$ GeV from AGS, SPS to RHIC. The $E_T$ and $N_{ch}$
production has been observed to follow a logarithmic behavior. The initial
energy density estimated by the boost-invariant Bjorken hydrodynamic model, is
well above the lattice QCD value for a deconfined matter of Quarks and Gluons.
Taking similar colliding species i.e. Au+Au, the $\epsilon_{Bj} .\tau$ has been
predicted for LHC, based on the measurements at RHIC. We have also made
predictions for $(dE_T/d\eta)/(0.5 N_{part})$ and $(dN_{ch}/d\eta)/(0.5
N_{part})$ for the LHC energy. Furthermore, we have studied the event-by event
fluctuations in $E_T$ and in the ratio of it's components using $\sigma/\mu$ as
the fluctuation observable.


title:
Negative differential resistivity in superconductors with periodic
  arrays of pinning sites

abstract:
  We study theoretically the effects of heating on the magnetic flux moving in
superconductors with a periodic array of pinning sites (PAPS). The
voltage-current characteristic (VI-curve) of superconductors with a PAPS
includes a region with negative differential resistivity (NDR) of S-type (i.e.,
S-shaped VI-curve), while the heating of the superconductor by moving flux
lines produces NDR of N-type (i.e., with an N-shaped VI-curve). We analyze the
instability of the uniform flux flow corresponding to different parts of the
VI-curve with NDR. Especially, we focus on the appearance of the filamentary
instability that corresponds to an S-type NDR, which is extremely unusual for
superconductors. We argue that the simultaneous existence of NDR of both N- and
S-type gives rise to the appearance of self-organized two-dimensional dynamical
structures in the flux flow mode. We study the effect of the pinning site
positional disorder on the NDR and show that moderate disorder does not change
the predicted results, while strong disorder completely suppresses the S-type
NDR.


title: The Structure of the Local Interstellar Medium V: Electron Densities

abstract:
  We present a comprehensive survey of CII* absorption detections toward stars
within 100 pc in order to measure the distribution of electron densities
present in the local interstellar medium (LISM). Using high spectral resolution
observations of nearby stars obtained by GHRS and STIS onboard the Hubble Space
Telescope, we identify 13 sight lines with 23 individual CII* absorption
components, which provide electron density measurements, the vast majority of
which are new. We employ several strategies to determine more accurate CII
column densities from the saturated CII resonance line, including, constraints
of the line width from the optically thin CII* line, constraints from
independent temperature measurements of the LISM gas based on line widths of
other ions, and third, using measured SII column densities as a proxy for CII
column densities. The sample of electron densities appears consistent with a
log-normal distribution and an unweighted mean value of n_e(CII_SII) =
0.11^+0.10_-0.05 cm^-3. Seven individual sight lines probe the Local
Interstellar Cloud (LIC), and all present a similar value for the electron
density, with a weighted mean of n_e(LIC) = 0.12 +/- 0.04 cm^-3. The Hyades
Cloud, a decelerated cloud at the leading edge of the platoon of LISM clouds,
has a significantly higher electron density than the LIC. Observed toward
G191-B2B, the high electron density may be caused by the lack of shielding from
such a strong radiation source. Given some simple assumptions, the range of
observed electron densities translates into a range of thermal pressures, P/k =
3300^+5500_-1900 K cm^-3. This work greatly expands the number of electron
density measurements and provides important constraints on the ionization,
abundance, and evolutionary models of the local interstellar medium. (abridged)


title:
On Type I singularities of the local axi-symmetric solutions of the
  Navier-Stokes equations

abstract:
  Local regularity of axially symmetric solutions to the Navier-Stokes
equations is studied. It is shown that under certain natural assumptions there
are no singularities of Type I.


title:
Submillimeter Observations of The Isolated Massive Dense Clump IRAS
  20126+4104

abstract:
  We used the CSO 10.4 meter telescope to image the 350 micron and 450 micron
continuum and CO J=6-5 line emission of the IRAS 20126+4104 clump. The
continuum and line observations show that the clump is isolated over a 4 pc
region and has a radius of ~ 0.5 pc. Our analysis shows that the clump has a
radial density profile propto r ^{-1.2} for r <~ 0.1 pc and has propto r^{-2.3}
for r >~ 0.1 pc which suggests the inner region is infalling, while the infall
wave has not yet reached the outer region. Assuming temperature gradient of
r^{-0.35}, the power law indices become propto r ^{-0.9} for r < ~0.1 pc and
propto r^{-2.0} for r >~ 0.1 pc. Based on a map of the flux ratio of
350micron/450micron, we identify three distinct regions: a bipolar feature that
coincides with the large scale CO bipolar outflow; a cocoon-like region that
encases the bipolar feature and has a warm surface; and a cold layer outside of
the cocoon region. The complex patterns of the flux ratio map indicates that
the clump is no longer uniform in terms of temperature as well as dust
properties. The CO emission near the systemic velocity traces the dense clump
and the outer layer of the clump shows narrow line widths (< ~3 km/s). The
clump has a velocity gradient of ~ 2 km/s pc^{-1}, which we interpret as due to
rotation of the clump, as the equilibrium mass (~ 200 Msun) is comparable to
the LTE mass obtained from the CO line. Over a scale of ~ 1 pc, the clump
rotates in the opposite sense with respect to the >~ 0.03 pc disk associated
with the (proto)star. This is one of four objects in high-mass and low-mass
star forming regions for which a discrepancy between the rotation sense of the
envelope and the core has been found, suggesting that such a complex kinematics
may not be unusual in star forming regions.


title: On SQCD with massive and massless flavors

abstract:
  We consider supersymmetric QCD in the free magnetic phase with massless and
massive flavors. The theory has a supersymmetry breaking pseudo-moduli space of
vacua and a runaway behavior far away from the origin. A two-loop computation
reveals that the origin is destabilized and there is no meta-stable SUSY
breaking solution. We also study the embedding of this model in type IIA string
theory and find evidence for similar behavior. The perturbative brane dynamics
involves simple interactions between branes, correctly predicting the two-loop
result in the gauge theory. Our results also apply to the case when all the
flavors are massive but have hierarchy among them, leading to possible
instability which is manifest both in field theory and the brane description.


title: Long-time Behavior for a Nonlinear Plate Equation with Thermal Memory

abstract:
  We consider a nonlinear plate equation with thermal memory effects due to
non-Fourier heat flux laws. First we prove the existence and uniqueness of
global solutions as well as the existence of a global attractor. Then we use a
suitable Lojasiewicz--Simon type inequality to show the convergence of global
solutions to single steady states as time goes to infinity under the assumption
that the nonlinear term $f$ is real analytic. Moreover, we provide an estimate
on the convergence rate.


title: Time evolution of epidemic disease on finite and infinite networks

abstract:
  Mathematical models of infectious diseases, which are in principle
analytically tractable, use two general approaches. The first approach,
generally known as compartmental modeling, addresses the time evolution of
disease propagation at the expense of simplifying the pattern of transmission.
The second approach uses network theory to incorporate detailed information
pertaining to the underlying contact structure among individuals while
disregarding the progression of time during outbreaks. So far, the only
alternative that enables the integration of both aspects of disease propagation
simultaneously while preserving the variety of outcomes has been to abandon the
analytical approach and rely on computer simulations. We offer a new analytical
framework, which incorporates both the complexity of contact network structure
and the time progression of disease spread. Furthermore, we demonstrate that
this framework is equally effective on finite- and "infinite"-size networks.
This formalism can be equally applied to similar percolation phenomena on
networks in other areas of science and technology.


title: Multi-scale fluctuations near a Kondo Breakdown Quantum Critical Point

abstract:
  We study the Kondo-Heisenberg model using a fermionic representation for the
localized spins. The mean-field phase diagram exhibits a zero temperature
quantum critical point separating a spin liquid phase where the f-conduction
hybridization vanishes, and a Kondo phase where it does not. Two solutions can
be stabilized in the Kondo phase, namely a uniform hybridization when the band
masses of the conduction electrons and the f spinons have the same sign, and a
modulated one when they have opposite sign. For the uniform case, we show that
above a very small Fermi liquid temperature scale (~1 mK), the critical
fluctuations associated with the vanishing hybridization have dynamical
exponent z=3, giving rise to a specific heat coefficient that diverges
logarithmically in temperature, as well as a conduction electron inverse
lifetime that has a T log T behavior. Because the f spinons do not carry
current, but act as an effective bath for the relaxation of the current carried
by the conduction electrons, the latter result also gives rise to a T log T
behavior in the resistivity. This behavior is consistent with observations in a
number of heavy fermion metals.


title: A Multi-Resolution Weak Lensing Mass Reconstruction Method

abstract:
  Motivated by the limitations encountered with the commonly used direct
reconstruction techniques of producing mass maps, we have developed a
multi-resolution maximum-likelihood reconstruction method for producing two
dimensional mass maps using weak gravitational lensing data. To utilize all the
shear information, we employ an iterative inverse method with a properly
selected regularization coefficient which fits the deflection potential at the
position of each galaxy. By producing mass maps with multiple resolutions in
the different parts of the observed field, we can achieve a comparable level of
signal to noise by increasing the resolution in regions of higher distortions
or regions with an over-density of background galaxies. In addition, we are
able to better study the sub-structure of the massive clusters at a resolution
which is not attainable in the rest of the observed field. We apply our method
to the simulated data and to a four square degree field obtained by the Deep
Lens Survey.


title: Last Passage Percolation in Macroscopically Inhomogeneous Media

abstract:
  In this note we investigate the last passage percolation model in the
presence of macroscopic inhomogeneity. We analyze how this affects the scaling
limit of the passage time, leading to a variational problem that provides an
ODE for the deterministic limiting shape of the maximal path. We obtain a
sufficient analytical condition for uniqueness of the solution for the
variational problem. Consequences for the totally asymmetric simple exclusion
process are discussed.


title: Space-Time Codes from Structured Lattices

abstract:
  We present constructions of Space-Time (ST) codes based on lattice coset
coding. First, we focus on ST code constructions for the short block-length
case, i.e., when the block-length is equal to or slightly larger than the
number of transmit antennas. We present constructions based on dense lattice
packings and nested lattice (Voronoi) shaping. Our codes achieve the optimal
diversity-multiplexing tradeoff of quasi-static MIMO fading channels for any
fading statistics, and perform very well also at practical, moderate values of
signal to noise ratios (SNR). Then, we extend the construction to the case of
large block lengths, by using trellis coset coding. We provide constructions of
trellis coded modulation (TCM) schemes that are endowed with good packing and
shaping properties. Both short-block and trellis constructions allow for a
reduced complexity decoding algorithm based on minimum mean squared error
generalized decision feedback equalizer (MMSE-GDFE) lattice decoding and a
combination of this with a Viterbi TCM decoder for the TCM case. Beyond the
interesting algebraic structure, we exhibit codes whose performance is among
the state-of-the art considering codes with similar encoding/decoding
complexity.


title:
Multiple and Precessing Collimated Outflows in the Planetary Nebula IC
  4634

abstract:
  With its remarkable double-S shape, IC 4634 is an archetype of
point-symmetric planetary nebulae (PN). In this paper, we present a detailed
study of this PN using archival HST WFPC2 and ground-based narrow-band images
to investigate its morphology, and long-slit spectroscopic observations to
determine its kinematics and to derive its physical conditions and excitation.
The data reveal new structural components, including a distant string of knots
distributed along an arc-like feature 40"-60" from the center of the nebula, a
skin of enhanced [O III]/H-alpha ratio enveloping the inner shell and the
double-S feature, and a triple-shell structure. The spatio-kinematical study
also finds an equatorial component of the main nebula that is kinematically
independent from the bright inner S-shaped arc. We have investigated in detail
the bow shock-like features in IC 4634 and found that their morphological,
kinematical and emission properties are consistent with the interaction of a
collimated outflow with surrounding material. Indeed, the morphology and
kinematics of some of these features can be interpreted using a 3D numerical
simulation of a collimated outflow precessing at a moderate, time-dependent
velocity. Apparently, IC 4634 has experienced several episodes of
point-symmetric ejections oriented at different directions with the outer
S-shaped feature being related to an earlier point-symmetric ejection and the
outermost arc-like string of knots being the relic of an even much earlier
point-symmetric ejection. There is tantalizing evidence that the action of
these collimated outflows has also taken part in the shaping of the innermost
shell and inner S-shaped arc of IC 4634.


title: A characterization of simplicial polytopes with g_2=1

abstract:
  Kalai proved that the simplicial polytopes with g_2=0 are the stacked
polytopes. We characterize the g_2=1 case. Specifically, we prove that every
simplicial d-polytope (d>=4) which is prime and with g_2=1 is combinatorially
equivalent either to a free sum of two simplices whose dimensions add up to d
(each of dimension at least 2), or to a free sum of a polygon with a
(d-2)-simplex. Thus, every simplicial d-polytope (d>=4) with g_2=1 is
combinatorially equivalent to a polytope obtained by stacking over a polytope
as above. Moreover, the above characterization holds for any homology
(d-1)-sphere (d>=4) with g_2=1, and our proof takes advantage of working with
this larger class of complexes.


title:
History of the Kohlrausch (stretched exponential) function: Focus on
  uncited pioneering work in luminescence

abstract:
  The first use of the stretched exponential function to describe the time
evolution of a non-equilibrium quantity is usually credited to Rudolph
Kohlrausch (1809-1858), who in 1854 applied it to the discharge of a capacitor.
Attention is drawn to a set of pioneering works on the Kohlrausch function, one
of which published 101 years ago, and that are not mentioned by Cardona,
Chamberlin, and Marx in Ann. Phys. (Leipzig) 16, 842 (2007).


title:
New Precise Measurement of the Pion Weak Form Factors in the Pi+ -> e+
  nu gamma Decay

abstract:
  We have measured the $\pi^+\to {\rm e}^+\nu\gamma$ branching ratio over a
wide region of phase space, based on a total of 65,460 events acquired using
the PIBETA detector. Minimum-$\chi^2$ fits to the measured $(E_{e^+},E_\gamma)$
energy distributions result in the weak form factor value of $F_A=0.0119(1)$
with a fixed value of $F_V=0.0259$. An unconstrained fit yields
$F_V=0.0258(17)$ and $F_A=0.0117(17)$. In addition, we have measured
$a=0.10(6)$ for the dependence of $F_V$ on $q^2$, the ${\rm e}^{+}\nu$ pair
invariant mass squared, parametrized as $F_V(q^2)=F_V(0)(1+a\cdot q^2)$. The
branching ratio for the kinematic region $E_\gamma > 10 $MeV and $\theta_{{\rm
e^+}\gamma} > 40^\circ $ is measured to be $B^{\rm exp}=73.86(54) \times
10^{-8}$. Earlier deviations we reported in the high-$E_\gamma$/low-$E_{{\rm
e}^+}$ kinematic region are resolved, and we find full compatibility with CVC
and standard $V$$-$$A$ calculations without a tensor term. We also derive new
values for the pion polarizability, $\alpha_E = \rm 2.78(10) \times 10^{-4}
fm^3$, and neutral pion lifetime, $\tau_{\pi 0} = (8.5 \pm 1.1) \times 10^{-17}
$s.


title: Morphologies and kinetics of a dewetting ultrathin solid film

abstract:
  The surface evolution model based on geometric partial differential equation
is used to numerically study the kinetics of dewetting and dynamic morphologies
for the localized pinhole defect in the surface of the ultrathin solid film
with the strongly anisotropic surface energy. Depending on parameters such as
the initial depth and width of the pinole, the strength of the attractive
substrate potential and the strength of the surface energy anisotropy, the
pinhole may either extend to the substrate and thus rupture the film, or evolve
to the quasiequilibrium shape while the rest of the film surface undergoes
phase separation into a hill-and-valley structure followed by coarsening.
Overhanging (non-graph) morphologies are possible for deep, narrow (slit-like)
pinholes.


title:
Formation and Size-Dependence of Vortex Shells in Mesoscopic
  Superconducting Niobium Disks

abstract:
  Recent experiments [I.V. Grigorieva et al., Phys. Rev. Lett. 96, 077005
(2006)] on visualization of vortices using the Bitter decoration technique
revealed vortex shells in mesoscopic superconducting Nb disks containing up to
L=40 vortices. Some of the found configurations did not agree with those
predicted theoretically. We show here that this discrepancy can be traced back
to the larger disks with radii R ~ 1 to 2.5\mu m, i.e., R ~ 50-100\xi(0) used
in the experiment, while in previous theoretical studies vortex states with
vorticity L < 40 were analyzed for smaller disks with R ~ 5-20\xi(0). The
present analysis is done for thin disks (mesoscopic regime) and for thick
(macroscopic) disks where the London screening is taken into account. We found
that the radius of the superconducting disk has a pronounced influence on the
vortex configuration in contrast to, e.g., the case of parabolic confined
charged particles. The missing vortex configurations and the region of their
stability are found, which are in agreement with those observed in the
experiment.


title: Origin of the energy bandgap in epitaxial graphene

abstract:
  We studied the effect of quantum confinement on the size of the band gap in
single layer epitaxial graphene. Samples with different graphene terrace sizes
are studied by using low energy electron microscopy (LEEM) and angle-resolved
photoemission spectroscopy (ARPES). The direct correlation between the terrace
size extracted from LEEM and the gap size extracted from ARPES shows that
quantum confinement alone cannot account for the large gap observed in
epitaxial graphene samples.


title:
Light curve and neutrino spectrum emitted during the collapse of a
  nonrotating, supermassive star

abstract:
  The formation of a neutrino pulse emitted during the relativistic collapse of
a spherical supermassive star is considered. The free collapse of a body with
uniform density in the absence of rotation and with the free escape of the
emitted neutrinos can be solved analytically by quadrature. The light curve of
the collapsing star and the spectrum of the emitted neutrinos at various times
are calculated.


title: Structure of Ann-Categories

abstract:
  This paper presents the structure conversion by which from an Ann-category
$\A,$ we can obtain its reduced Ann-category of the type $(R,M)$ whose
structure is a family of five functions $k=(\xi,\eta,\alpha,\lambda,\rho)$.
Then we will show that each Ann-category is determined by three invariants:
  1. The ring $\Pi_0(\A)$ of the isomorphic classes of objects of $\A$,
  2. $\Pi_0(\A)$-bimodule $\Pi_1(\A) = \Aut_{\A}(0),$
  3. The element $ \bar{k}\in H^{3}_{M}(\Pi_0(\A), \Pi_1(\A))$ (the ring
cohomology due to MacLane).


title: Clustering Property of Wolf-Rayet Galaxies in the SDSS

abstract:
  We have analysed, for the first time, the clustering properties of Wolf-Rayet
(W-R) galaxies, using a large sample of 846 W-R galaxies selected from the Data
Release 4 (DR4) of the SDSS. We compute the cross-correlation function between
W-R galaxies and a reference sample of galaxies drawn from the DR4. We compare
the function to the results for control samples of non-W-R star-forming
galaxies that are matched closely in redshift, luminosity, concentration,
4000-\AA break strength and specific star formation rate (SSFR). On scales
larger than a few Mpc, W-R galaxies have almost the same clustering amplitude
as the control samples, indicating that W-R galaxies and non-W-R control
galaxies populate dark matter haloes of similar masses. On scales between
0.1--1$h^{-1}$ Mpc, W-R galaxies are less clustered than the control samples,
and the size of the difference depends on the SSFR. Based on both observational
and theoretical considerations, we speculate that this negative bias can be
interpreted by W-R galaxies residing preferentially at the centers of their
dark matter haloes. We examine the distribution of W-R galaxies more closely
using the SDSS galaxy group catalogue of Yang et al., and find that $\sim$82%
of our W-R galaxies are the central galaxies of groups, compared to $\sim$74%
for the corresponding control galaxies. We find that W-R galaxies are hosted,
on average, by dark matter haloes of masses of$10^{12.3}M_\odot$, compared to
$10^{12.1}M_\odot$ for centrally-located W-R galaxies and $10^{12.7}M_\odot$
for satellite ones. We would like to point out that this finding, which
provides a direct observational support to our conjecture, is really very crude
due to the small number of W-R galaxies and the incompleteness of the group
catalogue, and needs more work in future with larger samples.


title: A possible signature of new physics at BES-III

abstract:
  The recent observations of the purely leptonic decay $\Ds \to \mu^+
\nu_{\mu}$ and $\tau^+\nu_{\tau}$ at CLEO-c and $B$ factory may allow a
possible contribution from a charged Higgs boson. One such measurement of the
decay constant $f_{D_s}$ differs from the most precise unquenched lattice QCD
calculation by 4 $\sigma$ level. Meanwhile, the measured ratio, ${\cal BR}(\Ds
\to \mu^+ \nu_{\mu})$ / ${\cal BR}(\Dp \to \mu^+ \nu_{\mu})$, is larger than
the standard model prediction at 2.0$\sigma$ level. We discuss that the precise
measurement of the ratio ${\cal BR}(\Ds \to \mu^+ \nu_{\mu})$ / ${\cal BR}(\Dp
\to \mu^+ \nu_{\mu})$ at BES-III will shed light on the presence of new
intermediate particles by comparing the theoretical predictions, especially,
the predictions of high precise unquenched lattice QCD calculation.


title: Note on Inversion Formula to Determine Binary Elements by Astrometry

abstract:
  Simplified solutions to determine binary elements by astrometry were obtained
in terms of elementary functions (Asada et al. 2004), and therefore require
neither iterative nor numerical methods. In the framework of the simplified
solution, this paper discusses the remaining two parameters of the time of
periastron passage and the longitude of ascending node in order to complete the
solution. We thus clarify a difference between the simplified solution and
other analytical methods.


title: Recrystallization of epitaxial GaN under indentation

abstract:
  We report recrystallization of epitaxial (epi-) GaN(0001) film under
indentation.Hardness value is measured close to 10 GPa, using a Berkovich
indenter. Pop-in burst in the loading line indicates nucleation of dislocations
setting in plastic motion of lattice atoms under stress field for the
recrystallization process. Micro-Raman studies are used to identify the
recrystallization process. Raman area mapping indicates the crystallized
region. Phonon mode corresponding to E2(high) close to 570 cm-1 in the as-grown
epi-GaN is redshifted to stress free value close to 567 cm-1 in the indented
region. Evolution of A1(TO) and E1(TO) phonon modes are also reported to
signify the recrystallization process.


title: Topological complexity of basis-conjugating automorphism groups

abstract:
  We compute the topological complexity of Eilenberg-Mac Lane spaces associated
to the group of automorphisms of a finitely generated free group which act by
conjugation on a given basis, and to certain subgroups.


title:
Light propagation through large-scale inhomogeneities in the Universe
  and its impact on cosmological observations

abstract:
  This paper analyses cosmological observations within inhomogeneous and exact
solutions of the Einstein equations. In some way the analyses presented here
can be freed from assumptions such as small amplitude of the density contrast.
The supernova observations are analysed using the Lema\itre-Tolman model and
the CMB observations are analysed using the quasispherical Szekeres model. The
results show that it is possible to fit the supernova data without the
cosmological constant. However if inhomogeneities of sizes and amplitudes as
observed in the local Universe are considered, their impact on cosmological
observations is small.


title:
Probing reheating temperature of the universe with gravitational wave
  background

abstract:
  Thermal history of the universe after big-bang nucleosynthesis (BBN) is well
understood both theoretically and observationally, and recent cosmological
observations also begin to reveal the inflationary dynamics. However, the epoch
between inflation and BBN is scarcely known. In this paper we show that the
detection of the stochastic gravitational wave background around 1Hz provides
useful information about thermal history well before BBN. In particular, the
reheating temperature of the universe may be determined by future space-based
laser interferometer experiments such as DECIGO and/or BBO if it is around
10^{6-9} GeV, depending on the tensor-to-scalar ratio $r$ and dilution factor
$F$.


title:
Evolution of a void and an adjacent galaxy supercluster in the
  quasispherical Szekeres model

abstract:
  This paper investigates the evolution of a void and an adjacent galaxy
supercluster. For this purpose the quasispherical Szekeres model is employed.
The Szekeres model is an exact solution of the Einstein field equations. In
this way investigations of the evolution of the cosmic structures presented
here can be freed from such assumptions as small amplitude of the density
contrast. Studying the evolution of a void and an adjacent supercluster results
not only in better understanding the evolution of cosmic structures but also in
acquainting us with the Szekeres model.
  The main results include the conclusion that small voids surrounded by large
overdensities evolve slower than large, isolated voids do. On the other hand,
large voids enhance the evolution of adjacent superclusters which evolve much
faster than isolated galaxy superclusters.


title:
Massive parallel generation of indistinguishable single photons via
  polaritonic superfluid to Mott-insulator quantum phase transition

abstract:
  We propose the superfluid to Mott-insulator quantum phase transition in an
array of exciton-polariton traps can be utilized for massive parallel
generation of indistinguishable single photons. By means of analytical and
numerical methods, the device operations and system properties are studied
using realistic experimental parameters. Such a deterministic, fault-tolerant,
massive parallel generation may open up a new perspective in photonic quantum
information processing.


title: Grassmann Geometries and Integrable Systems

abstract:
  We describe how the loop group maps corresponding to special submanifolds
associated to integrable systems may be thought of as certain Grassmann
submanifolds of infinite dimensional homogeneous spaces. In general, the
associated families of special submanifolds are certain Grassmann submanifolds.
An example is given from recent work of the author.


title: Kappa symmetric OSp(2|2) WZNW model

abstract:
  We construct a kappa symmetric WZNW model for the OSp(2|2) supergroup, whose
bosonic part is AdS3xS1 space. The field equation gives the chiral current
conservation and the right/left factorization is shown after the kappa symmetry
is fixed. The right-moving modes contain both bosons and fermions while the
left-moving modes contain only bosons.


title: Komar Integrals in Higher (and Lower) Derivative Gravity

abstract:
  The Komar integral relation of Einstein gravity is generalized to Lovelock
theories of gravity. This includes, in particular, a new boundary integral for
the Komar mass in Einstein gravity with a nonzero cosmological constant, which
has a finite result for asymptotically AdS black holes, without the need for an
infinite background subtraction. Explicit computations of the Komar mass are
given for black holes in pure Lovelock gravities of all orders and in general
Gauss-Bonnet theories.


title: Device Model for Graphene Nanoribbon Phototransistor

abstract:
  An analytical device model for a graphene nanoribbon phototransistor (GNR-PT)
is presented. GNR-PT is based on an array of graphene nanoribbons with the side
source and drain contacts, which is sandwiched between the highly conducting
substrate and the top gate. Using the developed model, we derive the explicit
analytical relationships for the source-drain current as a function of the
intensity and frequency of the incident radiation and find the detector
responsivity. It is shown that GNR-PTs can be rather effective photodetectors
in infrared and terahertz ranges of spectrum.


title:
Deeply inelastic pions in the exclusive reaction $p(e,e'\pi^+)n$ above
  the resonance region

abstract:
  A model for the $p(e,e'\pi^+)n$ reaction which combines an improved treatment
of gauge invariant meson--exchange currents and hard deep--inelastic scattering
(DIS) of virtual photons off nucleons is proposed. It is shown that DIS
dominates and explains the transverse response at moderate and high photon
virtualities $Q^2$ whereas the longitudinal response is dominated by hadronic
degrees of freedom and the pion electromagnetic form factor. This leads to a
combined description of the longitudinal and transverse components of the cross
section in a wide range of photon virtuality $Q^2$ and momentum transfer to the
target $t$ and solves the longstanding problem of the observed large transverse
cross sections. The latter are shown to be sensitive to the intrinsic
transverse momentum distribution of partons.


title: Dilatation Operator and Space-time Geometry

abstract:
  We discuss the possibility of defining a dynamical model describing the
RG-flow for a Quantum Field Theory. Construction of the dilatation operator is
discussed in details for one-vertex one-loop level.


title: Phase coherence and fragmentation in weakly interacting bosonic gases

abstract:
  We present a theory of measurement-induced interference for weakly
interacting Bose-Einstein condensed (BEC) gases. The many-body state resulting
from the evolution of an initial fragmented (Fock) state can be approximated as
a continuous superposition of Gross-Pitaevskii (GP) states; the measurement
breaks the initial phase symmetry, producing a distribution pattern
corresponding to only one of the GP solutions. We discuss also analytically
solvable models, such as two-mode on-chip adiabatic recombination and soliton
generation in quasi one-dimensional condensates.


title:
Mathematical analysis of long tail economy using stochastic ranking
  processes

abstract:
  We present a new method of estimating the distribution of sales rates of,
e.g., book titles at an online bookstore, from the time evolution of ranking
data found at websites of the store. The method is based on new mathematical
results on an infinite particle limit of the stochastic ranking process, and is
suitable for quantitative studies of the long tail structure of online retails.
We give an example of a fit to the actual data obtained from Amazon.co.jp,
which gives the Pareto slope parameter of the distribution of sales rates of
the book titles in the store.


title: AHS-structures and affine holonomies

abstract:
  We show that a large class of non-metric, non-symplectic affine holonomies
can be realized, uniformly and without case by case considerations, by Weyl
connections associated to the natural AHS-structures on certain generalized
flag manifolds.


title: Necessary and Sufficient Conditions on Sparsity Pattern Recovery

abstract:
  The problem of detecting the sparsity pattern of a k-sparse vector in R^n
from m random noisy measurements is of interest in many areas such as system
identification, denoising, pattern recognition, and compressed sensing. This
paper addresses the scaling of the number of measurements m, with signal
dimension n and sparsity-level nonzeros k, for asymptotically-reliable
detection. We show a necessary condition for perfect recovery at any given SNR
for all algorithms, regardless of complexity, is m = Omega(k log(n-k))
measurements. Conversely, it is shown that this scaling of Omega(k log(n-k))
measurements is sufficient for a remarkably simple ``maximum correlation''
estimator. Hence this scaling is optimal and does not require more
sophisticated techniques such as lasso or matching pursuit. The constants for
both the necessary and sufficient conditions are precisely defined in terms of
the minimum-to-average ratio of the nonzero components and the SNR. The
necessary condition improves upon previous results for maximum likelihood
estimation. For lasso, it also provides a necessary condition at any SNR and
for low SNR improves upon previous work. The sufficient condition provides the
first asymptotically-reliable detection guarantee at finite SNR.


title:
Selfish Distributed Compression over Networks: Correlation Induces
  Anarchy

abstract:
  We consider the min-cost multicast problem (under network coding) with
multiple correlated sources where each terminal wants to losslessly reconstruct
all the sources. We study the inefficiency brought forth by the selfish
behavior of the terminals in this scenario by modeling it as a noncooperative
game among the terminals. The degradation in performance due to the lack of
regulation is measured by the {\it Price of Anarchy} (POA), which is defined as
the ratio between the cost of the worst possible \textit{Wardrop equilibrium}
and the socially optimum cost. Our main result is that in contrast with the
case of independent sources, the presence of source correlations can
significantly increase the price of anarchy. Towards establishing this result,
we first characterize the socially optimal flow and rate allocation in terms of
four intuitive conditions. Next, we show that the Wardrop equilibrium is a
socially optimal solution for a different set of (related) cost functions.
Using this, we construct explicit examples that demonstrate that the POA $> 1$
and determine near-tight upper bounds on the POA as well. The main techniques
in our analysis are Lagrangian duality theory and the usage of the
supermodularity of conditional entropy.


title: Quantum Vacuum Friction in Highly Magnetized Neutron Stars

abstract:
  In this letter we calculate the energy loss of highly magnetized neutron star
due to friction with quantum vacuum, namely Quantum Vacuum Friction (QVF).
Taking into account one-loop corrections in the effective Heisenberg-Euler
Lagrangian of the light-light interaction, we derive an analytic expression for
QVF allowing us to consider magnetic field at the surface of the star as high
as $10^{11} $T. In the case of magnetars with high magnetic field above the QED
critical field, we show that the energy loss by QVF dominates the energy loss
process. This has important consequences, in particular on the inferred value
of the magnetic field. This also indicates the need for independent
measurements of magnetic field, energy loss rate, and of the braking index to
fully characterize magnetars.


title: The origin of globular cluster systems from cosmological simulations

abstract:
  We investigate the structural, kinematical, and chemical properties of
globular cluster systems (GCSs) in galaxies of different Hubble types in a
self-consistent manner based on high-resolution cosmological N-body simulations
combined with semi-analytic models of galaxy and globular cluster (GC)
formation. We focus on correlations between the physical properties of GCSs and
those of their host galaxies for about 10^5 simulated galaxies located at the
centres of dark matter halos (i.e. we do not consider satellite galaxies in
sub-halos). Our principal results, which can be tested against observations,
are as follows. The majority (about 90%) of GCs currently in halos are formed
in low-mass galaxies at redshifts greater than 3 with mean formation redshifts
of z = 5.7 (12.7 Gyrs ago) and 4.3 (12.3 Gyrs ago) for metal-poor GCs (MPC) and
metal-rich GCs (MRCs), respectively. About 52 % of galaxies with GCs show clear
bimodality in their metallicity distribution functions, though less luminous
galaxies with M_B fainter than -17 are much less likely to show bimodality
owing to little or no MRCs. The number fraction of MRCs does not depend on
Hubble type but is generally smaller for less luminous galaxies. The specific
frequencies (S_ N) of GCSs are typically higher in ellipticals (S_ N ~ 4.0)
than in spirals (S_ N ~ 1.8), and higher again (S_N ~ 5.0) for galaxies located
at the centers of clusters of galaxies. The total number of GCs per unit halo
mass does not depend strongly on M_B or Hubble type of the host galaxy. The
mean metallicities of MPCs and MRCs depend on M_B such that they are higher in
more luminous galaxies, though the dependence is significantly weakerfor MPCs.