title:
Resolving the bow-shock nebula around the old pulsar PSR B1929+10 with
  multi-epoch Chandra observations

abstract:
  We have studied the nearby old pulsar PSR B1929+10 and its surrounding
interstellar medium utilizing the sub-arcsecond angular resolution of the
Chandra X-ray Observatory. The Chandra data are found to be fully consistent
with the results obtained from deep XMM-Newton observations as far as the
pulsar is concerned. We confirm the non-thermal emission nature of the pulsar's
X-radiation. In addition to the X-ray trail already seen in previous
observations by the ROSAT and XMM-Newton X-ray observatories, we discovered an
arc-like nebula surrounding the pulsar. We interpret the feature as a bow-shock
nebula and discuss its energetics in the context of standard shock theory.


title: In-Medium Properties of Jets

abstract:
  Modifications of jet-like azimuthal correlations have revealed novel
properties of the medium created in relativistic heavy-ion collisions.
Experimental results on jet-like 2- and 3-particle correlations, specificly
"punch-through" at high transverse momentum, broadening at low and modest
transverse momentum, and particularly the possible experimental evidence for
conical flow, are reviewed. Future prospects of jet-like correlations and their
physics potential are discussed.


title: Very fast watermarking by reversible contrast mapping

abstract:
  Reversible contrast mapping (RCM) is a simple integer transform that applies
to pairs of pixels. For some pairs of pixels, RCM is invertible, even if the
least significant bits (LSBs) of the transformed pixels are lost. The data
space occupied by the LSBs is suitable for data hiding. The embedded
information bit-rates of the proposed spatial domain reversible watermarking
scheme are close to the highest bit-rates reported so far. The scheme does not
need additional data compression, and, in terms of mathematical complexity, it
appears to be the lowest complexity one proposed up to now. A very fast lookup
table implementation is proposed. Robustness against cropping can be ensured as
well.


title:
Representation theory, Radon transform and the heat equation on a
  Riemannian symmetric space

abstract:
  Let X=G/K be a Riemannian symmetric space of the noncompact type. We give a
short exposition of the representation theory related to X, and discuss its
holomorphic extension to the complex crown, a G-invariant subdomain in the
complexified symmetric space X_\C=G_\C/K_\C. Applications to the heat transform
and the Radon transform for X are given.


title:
Post-hatching parental care behaviour and hormonal status in a precocial
  bird

abstract:
  In birds, the link between parental care behaviour and prolactin release
during incubation persists after hatching in altricial birds, but has never
been precisely studied during the whole rearing period in precocial species,
such as ducks. The present study aims to understand how changes in parental
care after hatching are related to circulating prolactin levels in mallard hens
rearing ducklings. Blood was sampled in hens over at least 13 post-hatching
weeks and the behaviour of the hens and the ducklings was recorded daily until
fledging. Contacts between hens and the ducklings, leadership of the ducklings
and gathering of them steadily decreased over post-hatching time. Conversely,
resting, preening and agonistic behaviour of hens towards ducklings increased.
Plasma prolactin concentrations remained at high levels after hatching and then
fell after week 6 when body mass and structural size of the young were close to
those of the hen. Parental care behaviour declined linearly with brood age,
showed a disruption of the hen-brood bond at week 6 post-hatching and was
related to prolactin concentration according to a sigmoid function. Our results
suggest that a definite threshold in circulating prolactin is necessary to
promote and/or to maintain post-hatching parental care in ducks.


title: A New Generalization of Chebyshev Inequality for Random Vectors

abstract:
  In this article, we derive a new generalization of Chebyshev inequality for
random vectors. We demonstrate that the new generalization is much less
conservative than the classical generalization.


title: Holomorphic geometric models for representations of $C^*$-algebras

abstract:
  Representations of $C^*$-algebras are realized on section spaces of
holomorphic homogeneous vector bundles. The corresponding section spaces are
investigated by means of a new notion of reproducing kernel, suitable for
dealing with involutive diffeomorphisms defined on the base spaces of the
bundles. Applications of this technique to dilation theory of completely
positive maps are explored and the critical role of complexified homogeneous
spaces in connection with the Stinespring dilations is pointed out. The general
results are further illustrated by a discussion of several specific topics,
including similarity orbits of representations of amenable Banach algebras,
similarity orbits of conditional expectations, geometric models of
representations of Cuntz algebras, the relationship to endomorphisms of
${\mathcal B}({\mathcal H})$, and non-commutative stochastic analysis.


title:
Can dc voltage proportional to the persistent current be observed on
  segment of asymmetric mesoscopic ring?

abstract:
  In order to clear up a question on possibility of a dc voltage proportional
to the persistent current in normal metal and semiconductor mesoscopic loops
conjectural causes of this phenomenon observed in superconductor loops is
investigated.


title:
The Cyborg Astrobiologist: Porting from a wearable computer to the
  Astrobiology Phone-cam

abstract:
  We have used a simple camera phone to significantly improve an `exploration
system' for astrobiology and geology. This camera phone will make it much
easier to develop and test computer-vision algorithms for future planetary
exploration. We envision that the `Astrobiology Phone-cam' exploration system
can be fruitfully used in other problem domains as well.

categories: cs.CV astro-ph cs.AI cs.CE cs.HC cs.NI cs.RO cs.SE


title:
Microsolvation of cationic dimers in $^4$He droplets: geometries of
  A$_2^+$(He)$_N$ (A=Li,Na,K) from optimized energies

abstract:
  Ab initio computed interaction forces are employed in order to describe the
microsolvation of the A$_2^+(^2\Sigma)$ (A=Li,Na,K) molecular ion in $^4$He
clusters of small variable size. The minimum energy structures are obtained by
performing energy minimization based on a genetic algorithm approach. The
symmetry features of the collocation of solvent adatoms around the dimeric
cation are analyzed in detail, showing that the selective growth of small
clusters around the two sides of the ion during the solvation process is a
feature common to all three dopants.


title:
The MSST Campaign: II.Effective temperature and gravity variations in
  the multi-periodic pulsating subdwarf B star PG1605+072

abstract:
  Stellar oscillations are an important tool to probe the interior of a star.
Subdwarf B stars are core helium burning objects, but their formation is poorly
understood as neither single star nor binary evolution can fully explain their
observed properties. Since 1997 an increasing number of sdB stars has been
found to pulsate forming two classes of stars (the V361 Hya and V1093 Her
stars). We focus on the bright V 361 Hya star PG1605+072 to characterize its
frequency spectrum. While most previous studies relied on light variations, we
have measured radial velocity variations for as much as 20 modes. In this paper
we aim at characterizing the modes from atmospheric parameter and radial
velocity variations. Time resolved spectroscopy ($\approx$9000 spectra) has
been carried out to detect line profile variations from which variations of the
effective temperature and gravity are extracted by means of a quantitative
spectral analysis. We measured variations of effective temperatures and
gravities for eight modes with semi-amplitudes ranging from $\Delta
T_{\rm{eff}}=880$ K to as small as 88 K and $\Delta\log{g}$ of 0.08 dex to as
low as 0.008 dex. Gravity and temperature vary almost in phase, whereas phase
lags are found between temperature and radial velocity. This profound analysis
of a unique data set serves as sound basis for the next step towards an
identification of pulsation modes. As rotation may play an important role the
modelling of pulsation modes is challenging but feasible.


title: Hadron multiplicities at the LHC

abstract:
  We present the predictions for hadron multiplicities in pp, pA and AA
collisions at the LHC based on our approach to the Color Glass Condensate.


title:
Comment on ``New Physics Contributions to the Lifetime Difference in
  $D^0-\bar D^{0}$ mixing''

abstract:
  We find that in the nonmanifest left-right (LR) model, an important LR mixing
effect was not considered in the paper by E. Golowich, S. Pakvasa, and A.
Petrov, Phys. Rev. Lett. 98, 181801 (2007).


title:
Large Deviations Principle for Self-Intersection Local Times for random
  walk in dimension d>4

abstract:
  We obtain a large deviations principle for the self-intersection local times
for a symmetric random walk in dimension d>4. As an application, we obtain
moderate deviations for random walk in random sceneries in some region of
parameters.


title:
A diffraction-compensating 0-25 ns free space terahertz delay line for
  coherent quantum control

abstract:
  Free space delay lines provide pulses of variable time spacing for optical
experiments such as pump-probe spectroscopy and coherent quantum control,
including spin and photon echo techniques. However, in the terahertz (THz)
region of the spectrum, beam divergence due to diffraction limits the useful
length of traditional free space delay lines. We present a novel double-folded
variable delay line for light in the frequency range 0.24-1.2 THz, which
incorporates a symmetric arrangement of lenses whose spacing can be adjusted to
compensate for diffraction at each delay. Scalable for use in other wavelength
regimes, the design relays an input Gaussian beam waist to the output with up
to 25 ns (~8 m) total delay and is enclosed in a desiccated volume of <0.5 m^3.
The delay line can deliver two or three pulses with relative amplitudes
controlled via variable spacing silicon etalon beam splitters. Beam profiles of
a 0.24 THz beam show good agreement with calculations at long delays, with
insertion loss per delay stage of~3 dB.


title: Forward- and Mid-Rapidity Jet-like correlations

abstract:
  Mid-rapidity azimuthal correlations probe di-jets originating mainly from
gluon-gluon hard-scattering. Measurements of such correlations have revealed
significant (gluon-)jet modification in central Au+Au collisions. Azimuthal
correlations of hadrons at forward rapidity with a mid-rapidity high-$\pt$
hadron, on the other hand, probe asymmetric partonic scatterings involving
large-x quarks and small-x gluons. We present preliminary results from STAR on
correlations of charged hadrons at forward rapidity in the forward TPCs
($2.7<|\eta|<3.9$, $\pt<2$ GeV/$c$) with high-$\pt$ charged hadrons at
mid-rapidity from the main TPC ($|\eta|<1$, $\pt>3$ GeV/$c$) in $pp$, d+Au, and
Au+Au collisions at $\snn=200$ GeV. The implications of the results for small-x
gluon distributions (Color Glass Condensate formation) and the energy loss of
quark jets at forward rapidity in nuclear medium are discussed. %Their
measurements in d+Au collisions, separately at the d-side and the Au-side, may
be sensitive to Color Glass Condensate in the Au-nucleus. Their measurements in
Au+Au collisions may probe quark-jet modification in nuclear medium.


title:
Carbon-Enhanced Hyper-metal-poor Stars and the Stellar IMF at Low
  Metallicity

abstract:
  The two known ``hyper-metal-poor'' (HMP) stars, HE0107-5240 and HE1327-2326,
have extremely high enhancements of the light elements C, N, and O relative to
Fe and appear to represent a statistically significant excess population
relative to the halo metallicity distribution extrapolated from [Fe/H] > -3.
This study weighs the available evidence for and against three hypothetical
origins for these stars: (1) that they formed from gas enriched by a primordial
``faint supernova'', (2) that they formed from gas enriched by core-collapse
supernovae and C-rich gas ejected in rotation-driven winds from massive stars,
and (3) that they formed as the low-mass secondaries in binary systems at Z ~
10^{-5.5} Zsun and acquired their light-element enhancements from an
intermediate-mass companion as it passed through an AGB phase. The observations
interpreted here, especially the depletion of lithium seen in HE1327-2326,
favor the binary mass-transfer hypothesis. If HE0107-5240 and HE1327-2326
formed in binary systems, the statistically significant absence of isolated
and/or C-normal stars at similar [Fe/H] implies that low-mass stars could form
at that metallicity, but that masses M ~< 1.4 Msun were disfavored in the IMF.
This result is also explained if the abundance-derived top-heavy IMF for
primordial stars persists to [Fe/H] ~ -5.5. This finding indicates that
low-mass star formation was possible at extremely low metallicity, and that the
typical stellar mass may have had a complex dependence on metallicity rather
than a sharp transition driven solely by gas cooling.


title: Viscosity and jet quenching from holographic model

abstract:
  We consider the backreaction of the fundamental flavor degrees of freedom on
the AdS$_5$-Schwarz background, and calculate their contributions to the shear
viscosity and jet-quenching parameter of the thermal quark-gluon plasma.


title: The number of open paths in an oriented $\rho$-percolation model

abstract:
  We study the asymptotic properties of the number of open paths of length $n$
in an oriented $\rho$-percolation model. We show that this number is
$e^{n\alpha(\rho)(1+o(1))}$ as $n \to \infty$. The exponent $\alpha$ is
deterministic, it can be expressed in terms of the free energy of a polymer
model, and it can be explicitely computed in some range of the parameters.
Moreover, in a restricted range of the parameters, we even show that the number
of such paths is $n^{-1/2} W e^{n\alpha(\rho)}(1+o(1))$ for some nondegenerate
random variable $W$. We build on connections with the model of directed
polymers in random environment, and we use techniques and results developed in
this context.


title: Asteroseismology of delta Scuti stars in open clusters: Praesepe

abstract:
  The present paper provides a general overview of the asteroseismic potential
of delta Scuti stars in clusters, in particular focusing on convection
diagnostics. We give a summarise of the last results obtained by the authors
for the Praesepe cluster of which five delta Scuti stars are analysed. In that
work, linear analysis is confronted with observations, using refined
descriptions for the effects of rotation on the determination of the global
stellar parameters and on the adiabatic oscillation frequency computations. A
single, complete, and coherent solution for all the selected stars is found,
which lead the authors to find important restrictions to the convection
description for a certain range of effective temperatures. Furthermore, the
method used allowed to give an estimate of the global parameters of the
selected stars and constrain the cluster.


title:
Magnetic-order induced phonon splitting in MnO from far-infrared
  spectroscopy

abstract:
  Detailed far-infrared spectra of the optical phonons are reported for
antiferromagnetic MnO. Eigenfrequencies, phonon damping and effective plasma
frequencies are studied as a function of temperature. Special attention is paid
to the phonon splitting at the antiferromagnetic phase transition. The results
are compared to recent experimental and theoretical studies of the spin-phonon
coupling in frustrated magnets, which are explained in terms of a spin-driven
Jahn-Teller effect, and to ab initio and model calculations, which predict
phonon splitting induced by magnetic order.


title:
Analysis of radial fundamental-to-first overtone period ratios in the
  presence of near degeneracy

abstract:
  In the present work we provide the preliminary results obtained when
analysing the rotational Petersen diagrams when including the effects of near
degeneracy. We found that near degeneracy affects significantly the
fundamental-to-first overtone period ratios, showing wriggles in the Petersen
diagrams. Analysis of such wriggles reveals that they are mainly caused by the
avoided-crossing phenomenon. The size of wriggles seems to increase with the
rotational velocity and could, in certain cases, invalidate any accurate mass
and/or metallicity determinations. Nevertheless, deep analysis of near
degeneracy effects may allow us to obtain additional information on the mode
identification of the radial modes and their corresponding coupled pairs, which
would allow us to constrain the modelling.


title:
The mapping-torus of a free group automorphism is hyperbolic relative to
  the canonical subgroups of polynomial growth

abstract:
  We prove that the mapping torus group $\FN \rtimes_{\alpha} \Z$ of any
automorphism $\alpha$ of a free group $\FN$ of finite rank $n \geq 2$ is weakly
hyperbolic relative to the canonical (up to conjugation) family $\mathcal
H(\alpha)$ of subgroups of $\FN$ which consists of (and contains
representatives of all) conjugacy classes that grow polynomially under
iteration of $\alpha$. Furthermore, we show that $\FN \rtimes_{\alpha} \Z$ is
strongly hyperbolic relative to the mapping torus of the family $\mathcal
H(\alpha)$. As an application, we use a result of Drutu-Sapir to deduce that
$\FN \rtimes_{\alpha} \Z$ has Rapic Decay.


title: A Statistical Theory for the Analysis of Uncertain Systems

abstract:
  This paper addresses the issues of conservativeness and computational
complexity of probabilistic robustness analysis. We solve both issues by
defining a new sampling strategy and robustness measure. The new measure is
shown to be much less conservative than the existing one. The new sampling
strategy enables the definition of efficient hierarchical sample reuse
algorithms that reduce significantly the computational complexity and make it
independent of the dimension of the uncertainty space. Moreover, we show that
there exists a one to one correspondence between the new and the existing
robustness measures and provide a computationally simple algorithm to derive
one from the other.


title: Properties of new unflavored mesons below 2.4 GeV

abstract:
  The global features of spectrum of highly excited light nonstrange mesons can
be well understood within both chiral symmetry restoration scenario combined
with the relation $M^2\sim J+n$ and within nonrelativistic description based on
the relation $M^2\sim L+n$. The predictions of these two alternative
classifications for missing states are different and only future experiments
can distinguish between the two. We elaborate and compare systematically the
predictions of both schemes, which may serve as a suggestion for future
experiments devoted to the search for missing states.


title: Construction of Lagrangian local symmetries for general quadratic theory

abstract:
  We propose a procedure which allows one to construct local symmetry
generators of general quadratic Lagrangian theory. Manifest recurrence
relations for generators in terms of so-called structure matrices of the Dirac
formalism are obtained. The procedure fulfilled in terms of initial variables
of the theory, and do not implies either separation of constraints on first and
second class subsets or any other choice of basis for constraints.


title:
Selection of dominant multi-exciton transitions in disordered linear
  J-aggregates

abstract:
  We show that the third-order optical response of disordered linear
J-aggregates can be calculated by considering only a limited number of
transitions between (multi-) exciton states. We calculate the pump-probe
absorption spectrum resulting from the truncated set of transitions and show
that, apart from the blue wing of the induced absorption peak, it agrees well
with the exact spectrum.


title:
Fundamental Differences Between Application of Basic Principles of
  Quantum Mechanics on Atomic and Higher Levels

abstract:
  Superconductivity is macroscopic quantum phenomenon. From force of habit most
physicists pay no heed to a paradoxicality of this fact. Niels Bohr considered
quantum mechanics as atomic physics and the paradoxical quantum principles may
be admissible on this level. But they seem quite strange on the macroscopic
level. In the last years some experts, A. J. Leggett and other, attract our
attention to a contradiction between quantum mechanics and macroscopic realism.
In this paper I try to draw reader's attention to some paradoxical consequences
of the Bohr quantization on the macroscopic level.


title: Probabilistic Robustness Analysis -- Risks, Complexity and Algorithms

abstract:
  It is becoming increasingly apparent that probabilistic approaches can
overcome conservatism and computational complexity of the classical worst-case
deterministic framework and may lead to designs that are actually safer. In
this paper we argue that a comprehensive probabilistic robustness analysis
requires a detailed evaluation of the robustness function and we show that such
evaluation can be performed with essentially any desired accuracy and
confidence using algorithms with complexity linear in the dimension of the
uncertainty space. Moreover, we show that the average memory requirements of
such algorithms are absolutely bounded and well within the capabilities of
today's computers.
  In addition to efficiency, our approach permits control over statistical
sampling error and the error due to discretization of the uncertainty radius.
For a specific level of tolerance of the discretization error, our techniques
provide an efficiency improvement upon conventional methods which is inversely
proportional to the accuracy level; i.e., our algorithms get better as the
demands for accuracy increase.


title: Mesures limites pour l'equation de Helmholtz dans le cas non captif

abstract:
  Cet article est consacre a l'etude des mesures limites associees a la
solution de l'equation de Helmholtz avec un terme source se concentrant en un
point. Le potentiel est suppose regulier et l'operateur non-captif. La solution
de l'equation de Schrodinger semi-classique s'ecrit alors micro-localement
comme somme finie de distributions lagrangiennes.
  Sous une hypothese geometrique, qui generalise l'hypothese du viriel, on en
deduit que la mesure limite existe et qu'elle verifie des proprietes standard.
Enfin, on donne un exemple d'operateur qui ne verifie pas l'hypothese
geometrique et pour lequel la mesure limite n'est pas unique. Le cas de deux
termes sources est aussi traite.


title: A New Look at Mode Conversion in a Stratified Isothermal Atmosphere

abstract:
  Recent numerical investigations of wave propagation near coronal magnetic
null points (McLaughlin and Hood: Astron. Astrophys. 459, 641,2006) have
indicated how a fast MHD wave partially converts into a slow MHD wave as the
disturbance passes from a low-beta plasma to a high-beta plasma. This is a
complex process and a clear understanding of the conversion mechanism requires
the detailed investigation of a simpler model. An investigation of mode
conversion in a stratified, isothermal atmosphere, with a uniform, vertical
magnetic field is carried out, both numerically and analytically. In contrast
to previous investigations of upward-propagating waves (Zhugzhda and Dzhalilov:
Astron. Astrophys. 112, 16, 1982a; Cally: Astrophys. J. 548, 473, 2001), this
paper studies the downward propagation of waves from a low-beta to high-beta
environment. A simple expression for the amplitude of the transmitted wave is
compared with the numerical solution.


title:
Half-space theorem, embedded minimal annuli and minimal graphs in the
  Heisenberg group

abstract:
  We construct a one-parameter family of properly embedded minimal annuli in
the Heisenberg group Nil_3 endowed with a left-invariant Riemannian metric.
These annuli are not rotationally invariant. This family gives a vertical
half-space theorem and proves that each complete minimal graph in Nil_3 is
entire. Also, the sister surface of an entire minimal graph in Nil_3 is an
entire constant mean curvature 1/2 graph in H^2 x R, and conversely. This gives
a classification of all entire constant mean curvature 1/2 graphs in H^2 x R.
Finally we construct properly embedded constant mean curvature 1/2 annuli in
H^2 x R.


title: HESS J1616-508: likely powered by PSR J1617-5055

abstract:
  HESS J1616-508 is one of the brightest emitters in the TeV sky. Recent
observations with the IBIS/ISGRI telescope on board the INTEGRAL spacecraft
have revealed that a young, nearby and energetic pulsar, PSR J1617-5055, is a
powerful emitter of soft gamma-rays in the 20-100 keV domain. In this paper we
present an analysis of all available data from the INTEGRAL, Swift, BeppoSAX
and XMM-Newton telescopes with a view to assessing the most likely counterpart
to the HESS source. We find that the energy source that fuels the X/gamma-ray
emissions is derived from the pulsar, both on the basis of the positional
morphology, the timing evidence and the energetics of the system. Likewise, the
1.2% of the pulsar's spin down energy loss needed to power the 0.1-10 TeV
emission is also fully consistent with other HESS sources known to be
associated with pulsars. The relative sizes of the X/gamma-ray and VHE sources
are consistent with the expected lifetimes against synchrotron and Compton
losses for a single source of parent electrons emitted from the pulsar. We find
that no other known object in the vicinity could be reasonably considered as a
plausible counterpart to the HESS source. We conclude that there is good
evidence to assume that the HESS J1616-508 source is driven by PSR J1617-5055
in which a combination of synchrotron and inverse Compton processes combine to
create the observed morphology of a broad-band emitter from keV to TeV
energies.


title: Kirzhnits gradient expansion for a D-dimensional Fermi gas

abstract:
  For an ideal D-dimensional Fermi gas under generic external confinement we
derive the correcting coefficient $(D-2)/3D$ of the von Weizsacker term in the
kinetic energy density. To obtain this coefficient we use the Kirzhnits
semiclassical expansion of the number operator up to the second order in the
Planck constant $\hbar$. Within this simple and direct approach we determine
the differential equation of the density profile and the density functional of
the Fermi gas. In the case D=2 we find that the Kirzhnits gradient corrections
vanish to all order in $\hbar$.


title: Interaction, Change, and Wholeness of Material Things

abstract:
  Interaction is the mode of being of material things amid other material
things and the driving force of change and wholeness. Through mutual influence,
changes of interacting things become interdependent and their properties
interrelated, which leads to formation of ensembles - material wholes of
correlated things, where the mode of being of a particular component depends on
the modes of being of all other components and vice versa. Every ensemble
attains its wholeness and becomes a physical body through togetherness of
interrelated components coexisting as a collective being with mutually
restrained internal motion. Properties of ensembles on all structural levels of
matter composition emerge through the collective being of components.


title: The Euler characteristic of a category as the sum of a divergent series

abstract:
  The Euler characteristic of a cell complex is often thought of as the
alternating sum of the number of cells of each dimension. When the complex is
infinite, the sum diverges. Nevertheless, it can sometimes be evaluated; in
particular, this is possible when the complex is the nerve of a finite
category. This provides an alternative definition of the Euler characteristic
of a category, which is in many cases equivalent to the original one
(math.CT/0610260).


title:
Repr\'esentations de Springer pour les groupes de r\'eflexions complexes
  imprimitifs

abstract:
  To a spetsial complex reflection group, equipped with a root lattice in the
sense of Nebe, we attach a certain finite set playing a role which is analogous
to the role of the set of unipotent classes of an algebraic group. In the case
of imprimitive groups, we give a combinatoric parametrization of it in terms of
Malle-Shoji generalized symbols. This result provides a link between the works
of Shoji on Green functions for complex reflection groups and of Broue, Kim,
Malle, Rouquier, et. al. on the cyclotomic Hecke algebras and their families of
characters.
  -----
  A un groupe de reflexions complexe spetsial, muni d'un reseau radiciel au
sens de Nebe, nous associons un certain ensemble fini qui doit jouer un role
analogue a celui de l'ensemble des classes unipotentes d'un groupe algebrique.
Dans le cas des groupes imprimitifs, nous en donnons un parametrage
combinatoire en termes des symboles generalises de Malle et Shoji. Ce resultat
fournit un lien entre les travaux de Shoji sur les fonctions de Green pour les
groupes de reflexions complexes et ceux de Broue, Kim, Malle, Rouquier, et al.
sur les algebres de Hecke cyclotomiques et leurs familles de caracteres.


title:
Explicit Formula for Constructing Binomial Confidence Interval with
  Guaranteed Coverage Probability

abstract:
  In this paper, we derive an explicit formula for constructing the confidence
interval of binomial parameter with guaranteed coverage probability. The
formula overcomes the limitation of normal approximation which is asymptotic in
nature and thus inevitably introduce unknown errors in applications. Moreover,
the formula is very tight in comparison with classic Clopper-Pearson's approach
from the perspective of interval width. Based on the rigorous formula, we also
obtain approximate formulas with excellent performance of coverage probability.


title: Membrane instantons from mirror symmetry

abstract:
  We use mirror symmetry to determine and sum up a class of membrane instanton
corrections to the hypermultiplet moduli space metric arising in Calabi-Yau
threefold compactifications of type IIA strings. These corrections are mirror
to the D1 and D(-1)-brane instantons on the IIB side and are given explicitly
in terms of a single function in projective superspace. The corresponding
four-dimensional effective action is completely fixed by the Euler number and
the genus zero Gopakumar-Vafa invariants of the mirror Calabi-Yau.


title: A Gravitational Wave Background from Reheating after Hybrid Inflation

abstract:
  The reheating of the universe after hybrid inflation proceeds through the
nucleation and subsequent collision of large concentrations of energy density
in the form of bubble-like structures moving at relativistic speeds. This
generates a significant fraction of energy in the form of a stochastic
background of gravitational waves, whose time evolution is determined by the
successive stages of reheating: First, tachyonic preheating makes the amplitude
of gravity waves grow exponentially fast. Second, bubble collisions add a new
burst of gravitational radiation. Third, turbulent motions finally sets the end
of gravitational waves production. From then on, these waves propagate
unimpeded to us. We find that the fraction of energy density today in these
primordial gravitational waves could be significant for GUT-scale models of
inflation, although well beyond the frequency range sensitivity of
gravitational wave observatories like LIGO, LISA or BBO. However, low-scale
models could still produce a detectable signal at frequencies accessible to BBO
or DECIGO. For comparison, we have also computed the analogous gravitational
wave background from some chaotic inflation models and obtained results similar
to those found by other groups. The discovery of such a background would open a
new observational window into the very early universe, where the details of the
process of reheating, i.e. the Big Bang, could be explored. Moreover, it could
also serve in the future as a new experimental tool for testing the
Inflationary Paradigm.


title:
Fredholm Modules on P.C.F. Self-Similar Fractals and their Conformal
  Geometry

abstract:
  The aim of the present work is to show how, using the differential calculus
associated to Dirichlet forms, it is possible to construct Fredholm modules on
post critically finite fractals by regular harmonic structures. The modules are
d-summable, the summability exponent d coinciding with the spectral dimension
of the generalized laplacian operator associated with the regular harmonic
structures. The characteristic tools of the noncommutative infinitesimal
calculus allow to define a d-energy functional which is shown to be a
self-similar conformal invariant.


title:
Neutrino masses, mixing and leptogenesis in TeV scale B-L extension of
  the standard model

abstract:
  We address the issue of the neutrino masses and mixing in TeV scale $B-L$
extension of the Standard Model. We show that if Dirac neutrino masses are of
order $10^{-4}$ Gev, then the measured neutrino masses are correctly obtained.
We propose a mass relation between quarks and leptons that may account for such
small Dirac neutrino masses. We analyze the leptogenesis in this type of models
and provide analytical expressions for the new contributions due to the
predicted extra Higgs and extra neutral gauge boson. We find that thermal
leptogenesis, with a resonant enhancement due to nearly degenerate right-handed
neutrinos, can yield sufficient baryon asymmetry. Finally, we comment on a
possible scheme for non-thermal leptogenesis, which is due to the decay of
extra Higgs into right-handed neutrino.


title: Classical approximation to quantum cosmological correlations

abstract:
  We investigate up to which order quantum effects can be neglected in
calculating cosmological correlation functions after horizon exit. As a toy
model, we study $\phi^3$ theory on a de Sitter background for a massless
minimally coupled scalar field $\phi$. We find that for tree level and one loop
contributions in the quantum theory, a good classical approximation can be
constructed, but for higher loop corrections this is in general not expected to
be possible. The reason is that loop corrections get non-negligible
contributions from loop momenta with magnitude up to the Hubble scale H, at
which scale classical physics is not expected to be a good approximation to the
quantum theory. An explicit calculation of the one loop correction to the two
point function, supports the argument that contributions from loop momenta of
scale $H$ are not negligible. Generalization of the arguments for the toy model
to derivative interactions and the curvature perturbation leads to the
conclusion that the leading orders of non-Gaussian effects generated after
horizon exit, can be approximated quite well by classical methods. Furthermore
we compare with a theorem by Weinberg. We find that growing loop corrections
after horizon exit are not excluded, even in single field inflation.


title: Two chiral nonet model with massless quarks

abstract:
  We present a detailed study of a linear sigma model containing one chiral
nonet transforming under U(1)$_A$ as a quark-antiquark composite and another
chiral nonet transforming as a diquark-anti diquark composite (or, equivalently
from a symmetry point of view, as a two meson molecule). The model provides an
intuitive explanation of a current puzzle in low energy QCD: Recent work has
suggested the existence of a lighter than 1 GeV nonet of scalar mesons which
behave like four quark composites. On the other hand, the validity of a
spontaneously broken chiral symmetric description would suggest that these
states be chiral partners of the light pseudoscalar mesons, which are two quark
composites. The model solves the problem by starting with the two chiral nonets
mentioned and allowing them to mix with each other. The input of physical
masses in the SU(3) invariant limit for two scalar octets and an "excited" pion
octet results in a mixing pattern wherein the light scalars have a large four
quark content while the light pseudoscalars have a large two quark content. One
light isosinglet scalar is exceptionally light. In addition, the pion pion
scattering is also studied and the current algebra theorem is verified for
massless pions which contain some four quark admixture.


title: Spherical Needlets for CMB Data Analysis

abstract:
  We discuss Spherical Needlets and their properties. Needlets are a form of
spherical wavelets which do not rely on any kind of tangent plane approximation
and enjoy good localization properties in both pixel and harmonic space;
moreover needlets coefficients are asymptotically uncorrelated at any fixed
angular distance, which makes their use in statistical procedures very
promising. In view of these properties, we believe needlets may turn out to be
especially useful in the analysis of Cosmic Microwave Background (CMB) data on
the incomplete sky, as well as of other cosmological observations. As a final
advantage, we stress that the implementation of needlets is computationally
very convenient and may rely completely on standard data analysis packages such
as HEALPix.


title: Logarithmic limit sets of real semi-algebraic sets

abstract:
  This paper is about the logarithmic limit sets of real semi-algebraic sets,
and, more generally, about the logarithmic limit sets of sets definable in an
o-minimal, polynomially bounded structure. We prove that most of the properties
of the logarithmic limit sets of complex algebraic sets hold in the real case.
This include the polyhedral structure and the relation with the theory of
non-archimedean fields, tropical geometry and Maslov dequantization.


title:
Solitons in interacting Dicke models of coupled cavities with two-level
  systems

abstract:
  We consider an array of coupled optical cavities, each containing a
multi-atom ensemble. We show that the nonlinearity inherent in the cooperative
dynamics of the atoms in each ensemble coupled to the respective cavity field
allows for the formation of solitary waves. Such a prediction can be tested in
state-of-the-art semiconducting photonic-crystal microcavities with embedded
impurities.


title: Stochastic Inflationary Scalar Electrodynamics

abstract:
  We stochastically formulate the theory of scalar quantum electrodynamics on a
de Sitter background. This reproduces the leading infrared logarithms at each
loop order. It also allows one to sum the series of leading infrared logarithms
to obtain explicit, nonperturbative results about the late time behavior of the
system. One consequence is confirmation of the conjecture by Davis, Dimopoulos,
Prokopec and Tornkvist that super-horizon photons acquire mass during
inflation. We compute a photon mass-suqared of about 3.2991 H^2. The scalar
stays perturbatively light with a mass-squared of about 0.8961 3 e^2 H^2/8pi^2.
Interestingly, the induced change in the cosmological constant is negative, of
about -0.6551 3 G H^4/pi.


title: No-local-broadcasting theorem for quantum correlations

abstract:
  We prove that the correlations present in a multipartite quantum state have
an \emph{operational} quantum character as soon as the state does not simply
encode a multipartite classical probability distribution, i.e. does not
describe the joint state of many classical registers. Even unentangled states
may exhibit such \emph{quantumness}, that is pointed out by the new task of
\emph{local broadcasting}, i.e. of locally sharing pre-established
correlations: this task is feasible if and only if correlations are classical
and derive a no-local-broadcasting theorem for quantum correlations. Thus,
local broadcasting is able to point out the quantumness of correlations, as
standard broadcasting points out the quantum character of single system states.
Further, we argue that our theorem implies the standard no-broadcasting theorem
for single systems, and that our operative approach leads in a natural way to
the definition of measures for quantumness of correlations.


title:
Deposition of Atoms on a Quasicrystalline Substrate: Molecular-Dynamics
  Study in 3 Dimensions

abstract:
  We study the three-dimensional structure formation when atoms are deposited
onto a substrate with a decagonal quasicrystalline order.
Molecular-dynamicscalculations show that the adsorbate layer consists of
ordered nano-scale domains with orientations determined by the underlying
substrate symmetry. Depending on the relative strength of the interactions of
adsorbate atoms with each other and with the substrate atoms, different
morphologies are observed ranging from layer-by-layer growth to cluster
formation. We also find that the film thickness likewise affects the overall
structure of the growing film: Depending on the relative strength of the
interaction between adsorbate atoms, a structural transition of the
configuration of the adsorbate layers closest to the substrate can occur as the
number of deposited layers increases.


title: Regular and Completely Regular Differential Operators

abstract:
  We define the concept of completely regular ordinary differential operators
and give various criteria for operators to belong to this class. We give also
criteria for Birkhof regularity of ordinary differential operators in terms of
the growth of the Green function and basis property.


title: Determinant of the SU(N) caloron with nontrivial holonomy

abstract:
  The 1-loop quantum weight of the SU(N) KvBLL caloron with nontrivial holonomy
is calculated. The latter is the most general self-dual solution with unit
topological charge in the 4d Yang-Mills theory with one compactified dimension
(finite temperature).


title:
The CH2CN- molecule: Carrier of the lambda8037 diffuse interstellar
  band?

abstract:
  The hypothesis that the cyanomethyl anion CH2CN- is responsible for the
relatively narrow diffuse interstellar band (DIB) at 8037.8 +- 0.15 Angstroms
is examined with reference to new observational data. The 0_0^0 absorption band
arising from the ^1B_1 - X ^1A' transition from the electronic ground state to
the first dipole-bound state of the anion is calculated for a rotational
temperature of 2.7 K using literature spectroscopic parameters and results in a
rotational contour with a peak wavelength of 8037.78 Angstroms. By comparison
with diffuse band and atomic line absorption spectra of eight heavily-reddened
Galactic sightlines, CH2CN- is found to be a plausible carrier of the
lambda8037 diffuse interstellar band provided the rotational contour is
Doppler-broadened with a b parameter between 16 and 33 km/s that depends on the
specific sightline. Convolution of the calculated CH2CN- transitions with the
optical depth profile of interstellar Ti II results in a good match with the
profile of the narrow lambda8037 DIB observed towards HD 183143, HD 168112 and
Cyg OB2 8a. The rotational level populations may be influenced by nuclear spin
statistics, resulting in the appearance of additional transitions from K_a = 1
of ortho CH2CN- near 8025 and 8050 Angstroms that are not seen in currently
available interstellar spectra. For CH2CN- to be the carrier of the lambda8037
diffuse interstellar band, either a) there must be mechanisms that convert
CH2CN- from the ortho to the para form, or b) the chemistry that forms CH2CN-
must result in a population of K_a'' levels approaching a Boltzmann
distribution near 3 K.


title: Spectral isolation of naturally reductive metrics on simple Lie groups

abstract:
  We show that within the class of left-invariant naturally reductive metrics
$\mathcal{M}_{\operatorname{Nat}}(G)$ on a compact simple Lie group $G$, every
metric is spectrally isolated. We also observe that any collection of
isospectral compact symmetric spaces is finite; this follows from a somewhat
stronger statement involving only a finite part of the spectrum.


title: Adaptation and Coevolution on an Emergent Global Competitive Landscape

abstract:
  Notions of Darwinian selection have been implicit in economic theory for at
least sixty years. Richard Nelson and Sidney Winter have argued that while
evolutionary thinking was prevalent in prewar economics, the postwar
Neoclassical school became almost entirely preoccupied with equilibrium
conditions and their mathematical conditions. One of the problems with the
economic interpretation of firm selection through competition has been a weak
grasp on an incomplete scientific paradigm. As I.F. Price notes, "The
biological metaphor has long lurked in the background of management theory
largely because the message of 'survival of the fittest' (usually wrongly
attributed to Charles Darwin rather than Herbert Spencer) provides a seemingly
natural model for market competition (e.g. Alchian 1950, Merrell 1984,
Henderson 1989, Moore 1993), without seriously challenging the underlying
paradigms of what an organisation is." In this paper we examine the application
of dynamic fitness landscape models to economic theory, particularly the theory
of technology substitution, drawing on recent work by Kauffman, Arthur,
McKelvey, Nelson and Winter, and Windrum and Birchenhall. In particular we use
Professor Post's early work with John Holland on the genetic algorithm to
explain some of the key differences between static and dynamic approaches to
economic modeling.


title: On the Dynamical Behaviour of Cellular Automata

abstract:
  In this paper we study the dynamics of 1- and 2- dimensional cellular
automata, using a 2-adic representation of the states, we give a simple
graphical technique for finding periodic solutions. We also study the
continuity properties of the associated 2-adic system and show how to compute
the entropy.


title: Searching for tidal tails - investigating galaxy harassment

abstract:
  Galaxy harassment has been proposed as a physical process that
morphologically transforms low surface density disc galaxies into dwarf
elliptical galaxies in clusters. It has been used to link the observed very
different morphology of distant cluster galaxies (relatively more blue galaxies
with 'disturbed' morphologies) with the relatively large numbers of dwarf
elliptical galaxies found in nearby clusters. One prediction of the harassment
model is that the remnant galaxies should lie on low surface brightness tidal
streams or arcs. We demonstrate in this paper that we have an analysis method
that is sensitive to the detection of arcs down to a surface brightness of 29 B
mag/arcsec^2 and then use this method to search for arcs around 46 Virgo
cluster dwarf elliptical galaxies. We find no evidence for tidal streams or
arcs and consequently no evidence for galaxy harassment as a viable explanation
for the relatively large numbers of dwarf galaxies found in the Virgo cluster.


title:
Large-scale magnetic fields, curvature fluctuations and the thermal
  history of the Universe

abstract:
  It is shown that gravitating magnetic fields affect the evolution of
curvature perturbations in a way that is reminiscent of a pristine
non-adiabatic pressure fluctuation. The gauge-invariant evolution of curvature
perturbations is used to constrain the magnetic power spectrum. Depending on
the essential features of the thermodynamic history of the Universe, the
explicit derivation of the bound is modified. The theoretical uncertainty in
the constraints on the magnetic energy spectrum is assessed by comparing the
results obtained in the case of the conventional thermal history with the
estimates stemming from less conventional (but phenomenologically allowed)
post-inflationary evolutions.


title: Tracing Magnetic Fields with Aligned Grains

abstract:
  Magnetic fields play a crucial role in various astrophysical processes,
including star formation, accretion of matter, transport processes (e.g.,
transport of heat), and cosmic rays. One of the easiest ways to determine the
magnetic field direction is via polarization of radiation resulting from
extinction on or/and emission by aligned dust grains. Reliability of
interpretation of the polarization maps in terms of magnetic fields depends on
how well we understand the grain-alignment theory. Currently the
grain-alignment theory is a predictive one, and its results nicely match
observations. Among its predictions is a subtle phenomenon of radiative
torques. after having stayed in oblivion for many years after its discovery, is
currently viewed as the most powerful means of alignment. In this article, I
shall review the basic physical processes involved in grain alignment, and the
currently known mechanisms of alignment. I shall also discuss possible niches
for different alignment mechanisms. I shall dwell on the importance of the
concept of grain helicity for understanding of many properties of grain
alignment, and shall demonstrate that rather arbitrarily shaped grains exhibit
helicity when they interact with gaseous flows and radiative fluxes.


title:
Coherence and clock shifts in ultracold Fermi gases with resonant
  interactions

abstract:
  Using arguments based on sum rules, we derive a general result for the
average shifts of rf lines in Fermi gases in terms of interatomic interaction
strengths and two-particle correlation functions. We show that near an
interaction resonance shifts vary inversely with the atomic scattering length,
rather than linearly as in dilute gases, thus accounting for the experimental
observation that clock shifts remain finite at Feshbach resonances.


title:
On the Minimum Number of Transmissions in Single-Hop Wireless Coding
  Networks

abstract:
  The advent of network coding presents promising opportunities in many areas
of communication and networking. It has been recently shown that network coding
technique can significantly increase the overall throughput of wireless
networks by taking advantage of their broadcast nature. In wireless networks,
each transmitted packet is broadcasted within a certain area and can be
overheard by the neighboring nodes. When a node needs to transmit packets, it
employs the opportunistic coding approach that uses the knowledge of what the
node's neighbors have heard in order to reduce the number of transmissions.
With this approach, each transmitted packet is a linear combination of the
original packets over a certain finite field.
  In this paper, we focus on the fundamental problem of finding the optimal
encoding for the broadcasted packets that minimizes the overall number of
transmissions. We show that this problem is NP-complete over GF(2) and
establish several fundamental properties of the optimal solution. We also
propose a simple heuristic solution for the problem based on graph coloring and
present some empirical results for random settings.


title: Data-driven efficient score tests for deconvolution problems

abstract:
  We consider testing statistical hypotheses about densities of signals in
deconvolution models. A new approach to this problem is proposed. We
constructed score tests for the deconvolution with the known noise density and
efficient score tests for the case of unknown density. The tests are
incorporated with model selection rules to choose reasonable model dimensions
automatically by the data. Consistency of the tests is proved.


title: Scheduling in Data Intensive and Network Aware (DIANA) Grid Environments

abstract:
  In Grids scheduling decisions are often made on the basis of jobs being
either data or computation intensive: in data intensive situations jobs may be
pushed to the data and in computation intensive situations data may be pulled
to the jobs. This kind of scheduling, in which there is no consideration of
network characteristics, can lead to performance degradation in a Grid
environment and may result in large processing queues and job execution delays
due to site overloads. In this paper we describe a Data Intensive and Network
Aware (DIANA) meta-scheduling approach, which takes into account data,
processing power and network characteristics when making scheduling decisions
across multiple sites. Through a practical implementation on a Grid testbed, we
demonstrate that queue and execution times of data-intensive jobs can be
significantly improved when we introduce our proposed DIANA scheduler. The
basic scheduling decisions are dictated by a weighting factor for each
potential target location which is a calculated function of network
characteristics, processing cycles and data location and size. The job
scheduler provides a global ranking of the computing resources and then selects
an optimal one on the basis of this overall access and execution cost. The
DIANA approach considers the Grid as a combination of active network elements
and takes network characteristics as a first class criterion in the scheduling
decision matrix along with computation and data. The scheduler can then make
informed decisions by taking into account the changing state of the network,
locality and size of the data and the pool of available processing cycles.


title: Kinetic description of hadron-hadron collisions

abstract:
  A transport model based on the mean free path approach to describe pp
collisions is proposed. We assume that hadrons can be treated as bags of
partons similarly to the MIT bag model. When the energy density in the
collision is higher than a critical value, the bags break and partons are
liberated. The partons expand and can make coalescence to form new hadrons. The
results obtained compare very well with available data and some prediction for
higher energies collisions are discussed. Based on the model we suggest that a
QGP could already be formed in the pp collisions at high energies.


title: Self-gravitating radiation in AdS(d)

abstract:
  We study spherically symmetric equilibrium configurations of self-gravitating
massless thermal radiation in asymptotically anti-de Sitter space. In d=4, it
was shown by Page and Phillips that there is a maximum red-shifted temperature,
maximum mass and maximum entropy. For higher central densities, the
temperature, mass and entropy undergo an infinite series of damped
oscillations, corresponding to unstable configurations. We extend this work to
all dimensions $d\geq 3$. We find that in $4\leq d\leq 10$, the behaviour is
similar to the d=4 case. In $d\geq 11$, the temperature, mass and entropy are
monotonic functions of the central density, asymptoting to their maxima as the
central density goes to infinity. In d=3, an exact solution is given by a slice
of the AdS C-metric.


title:
Spectral properties of singular Sturm-Liouville operators with
  indefinite weight sgn x

abstract:
  We consider a singular Sturm-Liouville expression with the indefinite weight
sgn x. To this expression there is naturally a self-adjoint operator in some
Krein space associated. We characterize the local definitizability of this
operator in a neighbourhood of $\infty$. Moreover, in this situation, the point
$\infty$ is a regular critical point. We construct an operator $A=(\sgn
x)(-d^2/dx^2+q)$ with non-real spectrum accumulating to a real point. The
obtained results are applied to several classes of Sturm-Liouville operators.


title: Supersolidity, entropy and frustration

abstract:
  We study the properties of t-t'-V model of hard-core bosons on the triangular
lattice that can be realized in optical lattices. By mapping to the spin-1/2
XXZ model in a field, we determine the phase diagram of the t-V model where the
supersolid characterized by the ordering pattern (x,x,-2x') ("ferrimagnetic" or
SS A) is a ground state for chemical potential \mu >3V. By turning on either
temperature or t' at half-filling \mu =3V, we find a first order transition
from SS A to the elusive supersolid characterized by the (x,-x,0) ordering
pattern ("antiferromagnetic" or SS C). In addition, we find a large region
where a superfluid phase becomes a solid upon raising temperature at fixed
chemical potential. This is an analog of the Pomeranchuk effect driven by the
large entropic effects associated with geometric frustration on the triangular
lattice.


title: Frame dragging and super-energy

abstract:
  We show that the vorticity appearing in stationary vacuum spacetimes is
always related to the existence of a flow of super-energy on the plane
orthogonal to the vorticity vector. This result, toghether with the previously
established link between vorticity and super--energy in radiative (Bondi-Sachs)
spacetimes strength further the case for this latter quantity as the cause of
frame dragging.


title: Light Nuclei as Quantized Skyrmions

abstract:
  We consider the rigid body quantization of Skyrmions with topological charges
1 to 8, as approximated by the rational map ansatz. Novel, general expressions
for the elements of the inertia tensors, in terms of the approximating rational
map, are presented and are used to determine the kinetic energy contribution to
the total energy of the ground and excited states of the quantized Skyrmions.
Our results are compared to the experimentally determined energy levels of the
corresponding nuclei, and the energies and spins of a few as yet unobserved
states are predicted.


title:
Convexity of the self-energy functional in the variational cluster
  approximation

abstract:
  In the variational cluster approximation (VCA) (or variational cluster
perturbation theory), widely used to study the Hubbard model, a fundamental
problem that renders variational solutions difficult in practice is its known
lack of convexity at stationary points, i.e. the physical solutions can be
saddle points rather than extrema of the self-energy functional. Here we
suggest two different approaches to construct a convex functional of the
self-energy. In the first approach, one can show analytically that in the
approximation where the irreducible particle-hole vertex depends only on center
of mass coordinates, the functional is convex away from phase transitions in
the corresponding channel. Numerical tests on a tractable version of that
functional show that convexity can be a nuisance when looking for instabilities
both in the pairing and particle-hole channels. Therefore, an alternative
phenomenological functional is proposed. Convexity is explicitly enforced only
with respect to a restricted set of variables, such as the cluster chemical
potential that is known to be otherwise problematic. Numerical tests show that
our functional is convex at the physical solutions of VCA and allows
second-order phase transitions in the pairing channel as well. This opens the
way to the use of more efficient algorithms to find solutions of the VCA
equations.


title: Two-Dimensional Dynamics of Ultracold Atoms in Optical Lattices

abstract:
  We analyze the dynamics of ultracold atoms in optical lattices induced by a
sudden shift of the underlying harmonic trapping potential. In order to study
the effect of strong interactions, dimensionality and lattice topology on
transport properties, we consider bosonic atoms with arbitrarily strong
repulsive interactions, on a two-dimensional square lattice and a hexagonal
lattice. On the square lattice we find insulating behavior for weakly
interacting atoms and slow relaxation for strong interactions, even when a Mott
plateau is present, which in one dimension blocks the dynamics. On the
hexagonal lattice the center of mass relaxes to the new equilibrium for any
interaction strength.


title:
Optimal Linear Precoding Strategies for Wideband Non-Cooperative Systems
  based on Game Theory-Part II: Algorithms

abstract:
  In this two-part paper, we address the problem of finding the optimal
precoding/multiplexing scheme for a set of non-cooperative links sharing the
same physical resources, e.g., time and bandwidth. We consider two alternative
optimization problems: P.1) the maximization of mutual information on each
link, given constraints on the transmit power and spectral mask; and P.2) the
maximization of the transmission rate on each link, using finite order
constellations, under the same constraints as in P.1, plus a constraint on the
maximum average error probability on each link. Aiming at finding decentralized
strategies, we adopted as optimality criterion the achievement of a Nash
equilibrium and thus we formulated both problems P.1 and P.2 as strategic
noncooperative (matrix-valued) games. In Part I of this two-part paper, after
deriving the optimal structure of the linear transceivers for both games, we
provided a unified set of sufficient conditions that guarantee the uniqueness
of the Nash equilibrium. In this Part II, we focus on the achievement of the
equilibrium and propose alternative distributed iterative algorithms that solve
both games. Specifically, the new proposed algorithms are the following: 1) the
sequential and simultaneous iterative waterfilling based algorithms,
incorporating spectral mask constraints; 2) the sequential and simultaneous
gradient projection based algorithms, establishing an interesting link with
variational inequality problems. Our main contribution is to provide sufficient
conditions for the global convergence of all the proposed algorithms which,
although derived under stronger constraints, incorporating for example spectral
mask constraints, have a broader validity than the convergence conditions known
in the current literature for the sequential iterative waterfilling algorithm.


title: Hydrodynamics of fluid-solid coexistence in dense shear granular flow

abstract:
  We consider dense rapid shear flow of inelastically colliding hard disks.
Navier-Stokes granular hydrodynamics is applied accounting for the recent
finding \cite{Luding,Khain} that shear viscosity diverges at a lower density
than the rest of constitutive relations. New interpolation formulas for
constitutive relations between dilute and dense cases are proposed and
justified in molecular dynamics (MD) simulations. A linear stability analysis
of the uniform shear flow is performed and the full phase diagram is presented.
It is shown that when the inelasticity of particle collision becomes large
enough, the uniform sheared flow gives way to a two-phase flow, where a dense
"solid-like" striped cluster is surrounded by two fluid layers. The results of
the analysis are verified in event-driven MD simulations, and a good agreement
is observed.


title:
ExoPTF Science Uniquely Enabled by Far-IR Interferometry: Probing the
  Formation of Planetary Systems, and Finding and Characterizing Exoplanets

abstract:
  By providing sensitive sub-arcsecond images and integral field spectroscopy
in the 25 - 400 micron wavelength range, a far-IR interferometer will
revolutionize our understanding of planetary system formation, reveal
otherwise-undetectable planets through the disk perturbations they induce, and
spectroscopically probe the atmospheres of extrasolar giant planets in orbits
typical of most of the planets in our solar system. The technical challenges
associated with interferometry in the far-IR are greatly relaxed relative to
those encountered at shorter wavelengths or when starlight nulling is required.
A structurally connected far-IR interferometer with a maximum baseline length
of 36 m can resolve the interesting spatial structures in nascent and developed
exoplanetary systems and measure exozodiacal emission at a sensitivity level
critical to TPF-I mission planning. The Space Infrared Interferometric
Telescope was recommended in the Community Plan for Far-IR/Submillimeter Space
Astronomy, studied as a Probe-class mission, and estimated to cost 800M
dollars. The scientific communities in Europe, Japan, and Canada have also
demonstrated a keen interest in far-IR interferometry through mission planning
workshops and technology research, suggesting the possibility of an
international collaborative effort.


title:
Isometry theorem for the Segal-Bargmann transform on noncompact
  symmetric spaces of the complex type

abstract:
  We consider the Segal-Bargmann transform for a noncompact symmetric space of
the complex type. We establish isometry and surjectivity theorems for the
transform, in a form as parallel as possible to the results in the compact
case. The isometry theorem involves integration over a tube of radius R in the
complexification, followed by analytic continuation with respect to R. A
cancellation of singularities allows the relevant integral to have a
nonsingular extension to large R, even though the function being integrated has
singularities.


title:
Theory and Numerics of Gravitational Waves from Preheating after
  Inflation

abstract:
  Preheating after inflation involves large, time-dependent field
inhomogeneities, which act as a classical source of gravitational radiation.
The resulting spectrum might be probed by direct detection experiments if
inflation occurs at a low enough energy scale. In this paper, we develop a
theory and algorithm to calculate, analytically and numerically, the spectrum
of energy density in gravitational waves produced from an inhomogeneous
background of stochastic scalar fields in an expanding universe. We derive some
generic analytical results for the emission of gravity waves by stochastic
media of random fields, which can test the validity/accuracy of numerical
calculations. We contrast our method with other numerical methods in the
literature, and then we apply it to preheating after chaotic inflation. In this
case, we are able to check analytically our numerical results, which differ
significantly from previous works. We discuss how the gravity wave spectrum
builds up with time and find that the amplitude and the frequency of its peak
depend in a relatively simple way on the characteristic spatial scale amplified
during preheating. We then estimate the peak frequency and amplitude of the
spectrum produced in two models of preheating after hybrid inflation, which for
some parameters may be relevant for gravity wave interferometric experiments.


title: Quasi-Local Linear Momentum in Black-Hole Binaries

abstract:
  We propose a quasi-local formula for the linear momentum of black-hole
horizons inspired by the formalism of quasi-local horizons. We test this
formula using two complementary configurations: (i) by calculating the large
orbital linear momentum of the two black holes in an unequal-mass, zero-spin,
quasi-circular binary and (ii) by calculating the very small recoil momentum
imparted to the remnant of the head-on collision of an equal-mass,
anti-aligned-spin binary. We obtain results consistent with the horizon
trajectory in the orbiting case, and consistent with the net radiated linear
momentum for the much smaller head-on recoil velocity.


title:
Signatures of Extra Gauge Bosons in the Littlest Higgs Model with
  T-parity at Future Colliders

abstract:
  We study the collider signatures of a T-odd gauge boson $W_{H}$ pair
production in the Littlest Higgs Model with T-parity (LHT) at Large Hadron
Collider (LHC) and Linear Collider (LC). At the LHC, we search for the $W_{H}$
boson using its leptonic decay, i.e. $pp\to W_{H}^{+}W_{H}^{-}\to
A_{H}A_{H}\ell^{+}\nu_{\ell}\ell^{\prime-}\bar{\nu}_{\ell^{\prime}}$, which
gives rise to a collider signature of $\ell^{+}\ell^{\prime-}+\met$. We
demonstrate that the LHC not only has a great potential of discovering the
$W_{H}$ boson in this channel, but also can probe enormous parameter space of
the LHT. Due to four missing particles in the final state, one cannot
reconstruct the mass of $W_{H}$ at the LHC. But such a mass measurement can be
easily achieved at the LC in the process of $e^{+}e^{-}\to
W_{H}^{+}W_{H}^{-}\to A_{H}A_{H}W^{+}W^{-}\to A_{H}A_{H}jjjj$. We present an
algorithm of measuring the mass and spin of the $W_{H}$ boson at the LC.
Furthermore, we illustrate that the spin correlation between the $W$ boson and
its mother particle ($W_{H}$) can be used to distinguish the LHT from other new
physics models.


title:
Risk Analysis in Robust Control -- Making the Case for Probabilistic
  Robust Control

abstract:
  This paper offers a critical view of the "worst-case" approach that is the
cornerstone of robust control design. It is our contention that a blind
acceptance of worst-case scenarios may lead to designs that are actually more
dangerous than designs based on probabilistic techniques with a built-in risk
factor. The real issue is one of modeling. If one accepts that no mathematical
model of uncertainties is perfect then a probabilistic approach can lead to
more reliable control even if it cannot guarantee stability for all possible
cases. Our presentation is based on case analysis. We first establish that
worst-case is not necessarily "all-encompassing." In fact, we show that for
some uncertain control problems to have a conventional robust control solution
it is necessary to make assumptions that leave out some feasible cases. Once we
establish that point, we argue that it is not uncommon for the risk of
unaccounted cases in worst-case design to be greater than that of the accepted
risk in a probabilistic approach. With an example, we quantify the risks and
show that worst-case can be significantly more risky. Finally, we join our
analysis with existing results on computational complexity and probabilistic
robustness to argue that the deterministic worst-case analysis is not
necessarily the better tool.


title: Escape of Ionizing Radiation from High Redshift Galaxies

abstract:
  We model the escape of ionizing radiation from high-redshift galaxies using
high-resolution Adaptive Mesh Refinement N-body + hydrodynamics simulations.
Our simulations include time-dependent and spatially-resolved transfer of
ionizing radiation in three dimensions, including effects of dust absorption.
For galaxies of total mass M > 10^11 Msun and star formation rates SFR ~ 1-5
Msun/yr, we find angular averaged escape fractions of 0.01-0.03 over the entire
redshift interval studied (3<z<9). In addition, we find that the escape
fraction varies by more than an order of magnitude along different
lines-of-sight within individual galaxies, from the largest values near
galactic poles to the smallest along the galactic disk. The escape fraction
declines steeply at lower masses and SFR. We show that the low values of escape
fractions are due to a small fraction of young stars located just outside the
edge of HI disk. We compare our predicted escape fraction of ionizing photons
with previous results, and find a general agreement with both other simulation
results and available direct detection measurements at z ~ 3. We also compare
our simulations with a novel method to estimate the escape fraction in galaxies
from the observed distribution of neutral hydrogen column densities along the
lines of sights to long duration gamma-ray bursts. Using this method we find
escape fractions of the GRB host galaxies of 2-3%, consistent with our
theoretical predictions. [abridged]


title:
Defects Can Increase the Melting Temperature of DNA-Nanoparticle
  Assemblies

abstract:
  DNA-gold nanoparticle assemblies have shown promise as an alternative
technology to DNA microarrays for DNA detection and RNA profiling.
Understanding the effect of DNA sequences on the melting temperature of the
system is central to developing reliable detection technology. We studied the
effects of DNA base-pairing defects, such as mismatches and deletions, on the
melting temperature of DNA-nanoparticle assemblies. We found that, contrary to
the general assumption that defects lower the melting temperature of DNA, some
defects increase the melting temperature of DNA-linked nanoparticle assemblies.
The effects of mismatches and deletions were found to depend on the specific
base pair, the sequence, and the location of the defects. Our results
demonstrate that the surface-bound DNA exhibit hybridization behavior different
from that of free DNA. Such findings indicate that a detailed understanding of
DNA-nanoparticle assembly phase behavior is required for quantitative
interpretation of DNA-nanoparticle aggregation.


title:
SN 1993J VLBI (IV): A Geometric Determination of the Distance to M81
  with the Expanding Shock Front Method

abstract:
  We compare the angular expansion velocities, determined with VLBI, with the
linear expansion velocities measured from optical spectra for supernova 1993J
in the galaxy M81, over the period from 7 d to ~9 yr after shock breakout. We
estimate the distance to SN 1993J using the Expanding Shock Front Method (ESM).
We find the best distance estimate is obtained by fitting the angular velocity
of a point halfway between the contact surface and outer shock front to the
maximum observed hydrogen gas velocity. We obtain a direct, geometric, distance
estimate for M81 of D=3.96+-0.05+-0.29 Mpc with statistical and systematic
error contributions, respectively, corresponding to a total standard error of
$+-0.29 Mpc. The upper limit of 4.25 Mpc corresponds to the hydrogen gas with
the highest observed velocity reaching no farther out than the contact surface
a few days after shock breakout. The lower limit of 3.67 Mpc corresponds to
this hydrogen gas reaching as far out as the forward shock for the whole
period, which would mean that Rayleigh-Taylor fingers have grown to the forward
shock already a few days after shock breakout. Our distance estimate is 9+-13 %
larger than that of 3.63+-0.34 Mpc from the HST Key Project, which is near our
lower limit but within the errors.


title:
An algebraic theory of infinite classical lattices III: Theory of single
  measurements

abstract:
  This is the third in a series of papers dealing with the algebraic theory of
infinite classical lattices. This paper presents a theory of single
measurements on a lattice which we represent as comprising a finite
subvolume--the system of measurement--immersed in an infinite surround or
``heat bath'' which determines the system's state. We consider the class of all
stationary distributions on the set of microcanonical states of the infinite
lattice. The theory addresses the question, ``For a lattice initially in state
A, say, what is the probability that measurement of a certain quantity will
take a value in (a,b)?'' Discussion includes description of the source of
randomness in a measurement as well as characterization of the given states A.


title:
The Space Infrared Interferometric Telescope (SPIRIT): High-resolution
  imaging and spectroscopy in the far-infrared

abstract:
  We report results of a recently-completed pre-Formulation Phase study of
SPIRIT, a candidate NASA Origins Probe mission. SPIRIT is a spatial and
spectral interferometer with an operating wavelength range 25 - 400 microns.
SPIRIT will provide sub-arcsecond resolution images and spectra with resolution
R = 3000 in a 1 arcmin field of view to accomplish three primary scientific
objectives: (1) Learn how planetary systems form from protostellar disks, and
how they acquire their inhomogeneous composition; (2) characterize the family
of extrasolar planetary systems by imaging the structure in debris disks to
understand how and where planets of different types form; and (3) learn how
high-redshift galaxies formed and merged to form the present-day population of
galaxies. Observations with SPIRIT will be complementary to those of the James
Webb Space Telescope and the ground-based Atacama Large Millimeter Array. All
three observatories could be operational contemporaneously.


title: The Effective Field Theory of Codimension-two Branes

abstract:
  Distributional sources of matter on codimension-two and higher branes are
only well-defined as regularized objects. Nevertheless, intuition from
effective field theory suggests that the low-energy physics on such branes
should be independent of any high-energy regularization scheme. In this paper,
we address this issue in the context of a scalar field model where matter
fields (the standard model) living on such a brane interact with bulk fields
(gravity). The low-energy effective theory is shown to be consistent and
independent of the regularization scheme, provided the brane couplings are
renormalized appropriately at the classical level. We perform explicit
computations of the classical renormalization group flows at tree and one-loop
level, demonstrate that the theory is renormalizable against codimension-two
divergences, and extend the analysis to several physical applications such as
electrodynamics and brane localized kinetic terms.


title:
Observation of a uniform temperature dependence in the electrical
  resistance across the structural phase transition in thin film vanadium oxide
  ($VO_{2}$)

abstract:
  An electrical study of thin $VO_{2}$ films in the vicinity of the structural
phase transition at $68^{0}C$ shows (a) that the electrical resistance $R$
follows $log (R)$ $\propto$ $-T$ over the $T$-range, $20 < T < 80 ^{0}C$
covering both sides of the structural transition, and (b) a history dependent
hysteresis loop in $R$ upon thermal cycling. These features are attributed here
to transport through a granular network.


title: Radiative torques: Analytical Model and Basic Properties

abstract:
  We attempt to get a physical insight into grain alignment processes by
studying basic properties of radiative torques (RATs). For this purpose we
consider a simple toy model of a helical grain that reproduces well the basic
features of RATs. The model grain consists of a spheroidal body with a mirror
attached at an angle to it. Being very simple, the model allows analytical
description of RATs that act upon it. We show a good correspondence of RATs
obtained for this model and those of irregular grains calculated by DDSCAT. Our
analysis of the role of different torque components for grain alignment reveals
that one of the three RAT components does not affect the alignment, but induces
only for grain precession. The other two components provide a generic alignment
with grain long axes perpendicular to the radiation direction, if the radiation
dominates the grain precession, and perpendicular to magnetic field, otherwise.
We study a self-similar scaling of RATs as a function of $\lambda/a_{eff}$. We
show that the self-similarity is useful for studying grain alignment by a broad
spectrum of radiation, i.e. interstellar radiation field.


title: Di-lepton ttH At The CMS

abstract:
  In keeping with the "find the Higgs" bandwagon, due to embark together with
the Large Hadron Collider (LHC), we investigate discovery prospects with Higgs
produced in conjunction with two top quarks decaying in the dilepton channel.
The following is a brief account of adventures along the way; the interested
reader may find more in our CMS note.


title: Cosmic String Loops and Gravitational Radiation

abstract:
  Understanding of the signatures of cosmic string networks is limited by a
large uncertainty in the sizes at which cosmic string loops form. We review
cosmic string network evolution, and the gravitational signatures, with
emphasis on this uncertainty. We then review a recent analytic model of cosmic
string networks. In combination with recent simulations, this suggests that 90%
of the string goes into very small loops, at the gravitational radiation scale,
and 10% into loops near the Hubble scale. We discuss cosmic string signatures
in such a scenario, and the `inverse problem' of determining the microscopic
cosmic string properties from observations.


title: Deformation theory of representations of prop(erad)s

abstract:
  We study the deformation theory of morphisms of properads and props thereby
extending to a non-linear framework Quillen's deformation theory for
commutative rings. The associated chain complex is endowed with a Lie algebra
up to homotopy structure. Its Maurer-Cartan elements correspond to deformed
structures, which allows us to give a geometric interpretation of these
results.
  To do so, we endow the category of prop(erad)s with a model category
structure. We provide a complete study of models for prop(erad)s. A new
effective method to make minimal models explicit, that extends Koszul duality
theory, is introduced and the associated notion is called homotopy Koszul.
  As a corollary, we obtain the (co)homology theories of (al)gebras over a
prop(erad) and of homotopy (al)gebras as well. Their underlying chain complex
is endowed with a canonical Lie algebra up to homotopy structure in general and
a Lie algebra structure only in the Koszul case. In particular, we explicit the
deformation complex of morphisms from the properad of associative bialgebras.
For any minimal model of this properad, the boundary map of this chain complex
is shown to be the one defined by Gerstenhaber and Schack. As a corollary, this
paper provides a complete proof of the existence of a Lie algebra up to
homotopy structure on the Gerstenhaber-Schack bicomplex associated to the
deformations of associative bialgebras.


title: Are there Hilbert-style Pure Type Systems?

abstract:
  For many a natural deduction style logic there is a Hilbert-style logic that
is equivalent to it in that it has the same theorems (i.e. valid judgements
with empty contexts). For intuitionistic logic, the axioms of the equivalent
Hilbert-style logic can be propositions which are also known as the types of
the combinators I, K and S. Hilbert-style versions of illative combinatory
logic have formulations with axioms that are actual type statements for I, K
and S. As pure type systems (PTSs)are, in a sense, equivalent to systems of
illative combinatory logic, it might be thought that Hilbert-style PTSs (HPTSs)
could be based in a similar way. This paper shows that some PTSs have very
trivial equivalent HPTSs, with only the axioms as theorems and that for many
PTSs no equivalent HPTS can exist. Most commonly used PTSs belong to these two
classes. For some PTSs however, including lambda* and the PTS at the basis of
the proof assistant Coq, there is a nontrivial equivalent HPTS, with axioms
that are type statements for I, K and S.


title:
The Nash Equilibrium Revisited: Chaos and Complexity Hidden in
  Simplicity

abstract:
  The Nash Equilibrium is a much discussed, deceptively complex, method for the
analysis of non-cooperative games. If one reads many of the commonly available
definitions the description of the Nash Equilibrium is deceptively simple in
appearance. Modern research has discovered a number of new and important
complex properties of the Nash Equilibrium, some of which remain as
contemporary conundrums of extraordinary difficulty and complexity. Among the
recently discovered features which the Nash Equilibrium exhibits under various
conditions are heteroclinic Hamiltonian dynamics, a very complex asymptotic
structure in the context of two-player bi-matrix games and a number of
computationally complex or computationally intractable features in other
settings. This paper reviews those findings and then suggests how they may
inform various market prediction strategies.


title: Ground State of the Kagome Lattice Heisenberg Antiferromagnet

abstract:
  Using series expansions around the dimer limit, we show that the ground state
of the Heisenberg Antiferromagnet on the Kagome Lattice appears to be a Valence
Bond Crystal (VBC) with a 36-site unit cell, and an energy per site of
$E/J=-0.433\pm0.001$. It is a honeycomb lattice of `perfect hexagons' as
discussed by Nikolic and Senthil. The energy difference between the ground
state and other ordered states with the maximum number of `perfect hexagons',
such as a stripe-ordered state, is of order $0.001 J$. The energy of the
36-site system with periodic boundary conditions is further lowered by an
amount of $0.005\pm 0.001 J$, consistent with Exact Diagonalization. Every unit
cell of the VBC has two singlet states whose degeneracy is not lifted to $6th$
order in the expansion. We estimate this energy difference to be smaller than
$0.001 J$. Two leading orders of perturbation theory find the lowest-energy
triplet excitations to be dispersionless and confined to the `perfect
hexagons'.


title: Unparticle physics and Higgs phenomenology

abstract:
  Recently, conceptually new physics beyond the Standard Model has been
proposed, where a hidden conformal sector provides ``unparticle'' which couples
to the Standard Model sector through higher dimensional operators in low energy
effective theory. Among several possibilities, we focus on operators involving
unparticle, the Higgs doublet and the gauge bosons. Once the Higgs doublet
develops the vacuum expectation value, the conformal symmetry is broken and as
a result, the mixing between unparticle and Higgs boson emerges. We find that
this mixing can cause sizable shifts for the couplings between Higgs boson and
a pair of gluons and photons, because these couplings exist only at the loop
level in the Standard Model. These Higgs couplings are the most important ones
for the Higgs boson search at the CERN Large Hadron Collider, and the
unparticle physics effects may be observed together with the discovery of Higgs
boson.


title: Hybrid compactifications and brane gravity in six dimensions

abstract:
  We consider a six-dimensional axisymmetric Einstein-Maxwell model of warped
braneworlds. The bulk is bounded by two branes, one of which is a conical
3-brane and the other is a 4-brane wrapped around the axis of symmetry. The
latter brane is assumed to be our universe. If the tension of the 3-brane is
fine-tuned, it folds the internal two-dimensional space in a narrow cone,
making sufficiently small the Kaluza-Klein circle of the 4-brane. An arbitrary
energy-momentum tensor can be accommodated on this ring-like 4-brane. We study
linear perturbations sourced by matter on the brane, and show that weak gravity
is apparently described by a four-dimensional scalar-tensor theory. The extra
scalar degree of freedom can be interpreted as the fluctuation of the internal
space volume (or that of the circumference of the ring), the effect of which
turns out to be suppressed at long distances. Consequently, four-dimensional
Einstein gravity is reproduced on the brane. We point out that as in the
Randall-Sundrum model, the brane bending mode is crucial for recovering the
four-dimensional tensor structure in this setup.


title: Segmentation and Context of Literary and Musical Sequences

abstract:
  We test a segmentation algorithm, based on the calculation of the
Jensen-Shannon divergence between probability distributions, to two symbolic
sequences of literary and musical origin. The first sequence represents the
successive appearance of characters in a theatrical play, and the second
represents the succession of tones from the twelve-tone scale in a keyboard
sonata. The algorithm divides the sequences into segments of maximal
compositional divergence between them. For the play, these segments are related
to changes in the frequency of appearance of different characters and in the
geographical setting of the action. For the sonata, the segments correspond to
tonal domains and reveal in detail the characteristic tonal progression of such
kind of musical composition.


title: Shocked Molecular Hydrogen in the 3C 326 Radio Galaxy System

abstract:
  The Spitzer spectrum of the giant FR II radio galaxy 3C 326 is dominated by
very strong molecular hydrogen emission lines on a faint IR continuum. The H2
emission originates in the northern component of a double-galaxy system
associated with 3C 326. The integrated luminosity in H2 pure-rotational lines
is 8.0E41 erg/s, which corresponds to 17% of the 8-70 micron luminosity of the
galaxy. A wide range of temperatures (125-1000 K) is measured from the H2 0-0
S(0)-S(7) transitions, leading to a warm H2 mass of 1.1E9 Msun. Low-excitation
ionic forbidden emission lines are consistent with an optical LINER
classification for the active nucleus, which is not luminous enough to power
the observed H2 emission. The H2 could be shock-heated by the radio jets, but
there is no direct indication of this. More likely, the H2 is shock-heated in a
tidal accretion flow induced by interaction with the southern companion galaxy.
The latter scenario is supported by an irregular morphology, tidal bridge, and
possible tidal tail imaged with IRAC at 3-9 micron. Unlike ULIRGs, which in
some cases exhibit H2 line luminosities of comparable strength, 3C 326 shows
little star-formation activity (~0.1 Msun/yr). This may represent an important
stage in galaxy evolution. Starburst activity and efficient accretion onto the
central supermassive black hole may be delayed until the shock-heated H2 can
kinematically settle and cool


title: Orbital Solution & Fundamental Parameters of sigma Scorpii

abstract:
  The first orbital solution for the spectroscopic pair in the multiple star
system sigma Scorpii, determined from measurements with the Sydney University
Stellar Interferometer (SUSI), is presented. The primary component is of beta
Cephei variable type and has been one of the most intensively studied examples
of its class. The orbital solution, when combined with radial velocity results
found in the literature, yields a distance of 174(+23,-18) pc, which is
consistent with, but more accurate than the Hipparcos value. For the primary
component we determine 18.4+/-5.4 M_sun, -4.12+/-0.34 mag and 12.7+/-1.8 R_sun
for the mass, absolute visual magnitude and radius respectively. A B1 dwarf
spectral type and luminosity class for the secondary is proposed from the mass
determination of 11.9+/-3.1 M_sun and the estimated system age of 10 Myr.


title: Entanglement and Irreversibility in the Approach to Thermal Equilibrium

abstract:
  When a physical system is put in contact with a very large thermal bath, it
undergoes a dissipative (i.e., an apparently irreversible) process that leads
to thermal equilibrium. This dynamical process can be described fully within
quantum physics, involving only unitary, therefore reversible, maps. The
information, initially present in the system, is not erased, but is diluted in
the bath because of entanglement. Irreversibility may arise if, after quantum
information has been thus diluted, some classical information is lost. This
paper reviews a model for thermalization that displays these features. Two new
analytical results are provided for the zero-temperature channels: a new
quantitative measure of entanglement, and a study of irreversibility in the
case where the lost classical information is the label of the particles in the
bath.


title: Broken SU(3) Flavor Symmetry and Tribimaximal Neutrino Mixing

abstract:
  Recent work on a lepton mass matrix model based on an SU(3) flavor symmetry
which is broken into S_4 is reviewed. The flavor structures of the masses and
mixing are caused by VEVs of SU(2)_L-singlet scalars \phi which are nonets
({\bf 8}+{\bf 1}) of the SU(3) flavor symmetry, and which are broken into {\bf
2}+{\bf 3}+{\bf 3}' and {\bf 1} of S_4. If we require the invariance under the
transformation (\phi^{(8)},\phi^{(1)}) \to (-\phi^{(8)},+\phi^{(1)}) for the
superpotential of the nonet field \phi^{(8+1)}, the model leads to a beautiful
relation for the charged lepton masses. The observed tribimaximal neutrino
mixing is understood by assuming two SU(3) singlet right-handed neutrinos
\nu_R^{(\pm)} and an SU(3) triplet scalar \chi.


title: Traversable Wormholes Construction in (2+1) Gravity

abstract:
  Wormholes have been always an interesting object in gravity theories. In this
paper we make a little review of the principal properties of these objects and
the exotic matter they need to exist. Then, we obtain two specific solutions in
the formalism of (2+1)-dimensional gravity with negative cosmological constant.
The obtained geometries correspond to traversable wormholes with an exterior
geometry correspondient to the well known BTZ black hole solution. We also
discuss the distribution of exotic matter that these wormholes need.


title: Effect of time delay on feedback control of a flashing ratchet

abstract:
  It was recently shown that the use of feedback control can improve the
performance of a flashing ratchet. We investigate the effect of a time delay in
the implementation of feedback control in a closed-loop collective flashing
ratchet, using Langevin dynamics simulations. Surprisingly, for a large
ensemble, a well-chosen delay time improves the ratchet performance by allowing
the system to synchronize into a quasi-periodic stable mode of oscillation that
reproduces the optimal average velocity for a periodically flashing ratchet.
For a small ensemble, on the other hand, finite delay times significantly
reduce the benefit of feedback control for the time-averaged velocity, because
the relevance of information decays on a time scale set by the diffusion time
of the particles. Based on these results, we establish that experimental use of
feedback control is realistic.


title: Flow Representation of the Bose-Hubbard Hamiltonian : General Case

abstract:
  In this paper the explicit flow representation to the Bose-Hubbard
Hamiltonian is given in the general case. This representation may be useful in
creating cat states for the system of atoms trapped in the optical ring.


title: Loss-tolerant operations in parity-code linear optics quantum computing

abstract:
  A heavy focus for optical quantum computing is the introduction of
error-correction, and the minimisation of resource requirements. We detail a
complete encoding and manipulation scheme designed for linear optics quantum
computing, incorporating scalable operations and loss-tolerant architecture.


title: Brown representability for space-valued functors

abstract:
  In this paper we prove two theorems which resemble the classical
cohomological and homological Brown representability theorems. The main
difference is that our results classify small contravariant functors from
spaces to spaces up to weak equivalence of functors.
  In more detail, we show that every small contravariant functor from spaces to
spaces which takes coproducts to products up to homotopy and takes homotopy
pushouts to homotopy pullbacks is naturally weekly equivalent to a
representable functor.
  The second representability theorem states: every contravariant continuous
functor from the category of finite simplicial sets to simplicial sets taking
homotopy pushouts to homotopy pullbacks is equivalent to the restriction of a
representable functor. This theorem may be considered as a contravariant analog
of Goodwillie's classification of linear functors.


title: Muon Identification at ATLAS and CMS

abstract:
  Muonic final states will provide clean signatures formany physics processes
at the LHC. The two LHC experiments ATLAS and CMS will be able to identify
muons with a high reconstruction efficiency above 96% and a high transverse
momentum resolution better than 2% for transverse momenta below 400 GeV/c and
about 10% at 1 TeV/c. The two experiments follow complentary concepts of muon
detection. ATLAS has an instrumented air-toroid mangetic system serving as a
stand-alone muon spectrometer. CMS relies on high bending power and momentum
resolution in the inner detector, and uses an iron yoke to increase its
magnetic field. The iron yoke is instrumented with chambers used for muon
identification. Therefore, muon momenta can only be reconstructed with high
precision by combining inner-detector information with the data from the muon
chambers.


title: A spectral sequence to compute L2-Betti numbers of groups and groupoids

abstract:
  We construct a spectral sequence for L2-type cohomology groups of discrete
measured groupoids. Based on the spectral sequence, we prove the Hopf-Singer
conjecture for aspherical manifolds with poly-surface fundamental groups. More
generally, we obtain a permanence result for the Hopf-Singer conjecture under
taking fiber bundles whose base space is an aspherical manifold with
poly-surface fundamental group. As further sample applications of the spectral
sequence, we obtain new vanishing theorems and explicit computations of
L2-Betti numbers of groups and manifolds and obstructions to the existence of
normal subrelations in measured equivalence relations.


title:
The concrete theory of numbers : Problem of simplicity of Fermat
  number-twins

abstract:
  The problem of simplicity of Fermat number-twins $f_{n}^{\pm}=2^{2^n}\pm3$ is
studied. The question for what $n$ numbers $f_{n}^{\pm}$ are composite is
investigated. The factor-identities for numbers of a kind $x^2 \pm k $ are
found.


title: Reheating and Cosmic String Production

abstract:
  We compute the string production rate at the end of inflation, using the
string spectrum obtained in \lss in a near-de Sitter space. Our result shows
that highly excited strings are hardly produced, thus the simple slow-roll
inflation alone does not offer a cosmic string production mechanism.


title:
Spectrum Sensing in Cognitive Radios Based on Multiple Cyclic
  Frequencies

abstract:
  Cognitive radios sense the radio spectrum in order to find unused frequency
bands and use them in an agile manner. Transmission by the primary user must be
detected reliably even in the low signal-to-noise ratio (SNR) regime and in the
face of shadowing and fading. Communication signals are typically
cyclostationary, and have many periodic statistical properties related to the
symbol rate, the coding and modulation schemes as well as the guard periods,
for example. These properties can be exploited in designing a detector, and for
distinguishing between the primary and secondary users' signals. In this paper,
a generalized likelihood ratio test (GLRT) for detecting the presence of
cyclostationarity using multiple cyclic frequencies is proposed. Distributed
decision making is employed by combining the quantized local test statistics
from many secondary users. User cooperation allows for mitigating the effects
of shadowing and provides a larger footprint for the cognitive radio system.
Simulation examples demonstrate the resulting performance gains in the low SNR
regime and the benefits of cooperative detection.