title: Characterization of P2P IPTV Traffic: Scaling Analysis

abstract:
  P2P IPTV applications arise on the Internet and will be massively used in the
future. It is expected that P2P IPTV will contribute to increase the overall
Internet traffic. In this context, it is important to measure the impact of P2P
IPTV on the networks and to characterize this traffic. Dur- ing the 2006 FIFA
World Cup, we performed an extensive measurement campaign. We measured network
traffic generated by broadcasting soc- cer games by the most popular P2P IPTV
applications, namely PPLive, PPStream, SOPCast and TVAnts. From the collected
data, we charac- terized the P2P IPTV traffic structure at different time
scales by using wavelet based transform method. To the best of our knowledge,
this is the first work, which presents a complete multiscale analysis of the
P2P IPTV traffic. Our results show that the scaling properties of the TCP
traffic present periodic behavior whereas the UDP traffic is stationary and
lead to long- range depedency characteristics. For all the applications, the
download traffic has different characteristics than the upload traffic. The
signaling traffic has a significant impact on the download traffic but it has
negligible impact on the upload. Both sides of the traffic and its granularity
has to be taken into account to design accurate P2P IPTV traffic models.


title:
The Long Period, Massive Binaries HD 37366 and HD 54662: Potential
  Targets for Long Baseline Optical Interferometry

abstract:
  We present the results from an optical spectroscopic analysis of the massive
stars HD 37366 and HD 54662. We find that HD 37366 is a double-lined
spectroscopic binary with a period of 31.8187 +/- 0.0004 days, and HD 54662 is
also a double lined binary with a much longer period of 557.8 +/- 0.3 days. The
primary of HD 37366 is classified as O9.5 V, and it contributes approximately
two-thirds of the optical flux. The less luminous secondary is a broad-lined,
early B-type main-sequence star. Tomographic reconstruction of the individual
spectra of HD 37366 reveals absorption lines present in each component,
enabling us to constrain the nature of the secondary and physical
characteristics of both stars. Tomographic reconstruction was not possible for
HD 54662; however, we do present mean spectra from our observations that show
that the secondary component is approximately half as bright as the primary.
The observed spectral energy distributions (SEDs) were fit with model SEDs and
galactic reddening curves to determine the angular sizes of the stars. By
assuming radii appropriate for their classifications, we determine distance
ranges of 1.4 - 1.9 and 1.2 - 1.5 kpc for HD 37366 and HD 54662, respectively.


title:
Time scale of entropic segregation of flexible polymers in confinement:
  Implications for chromosome segregation in filamentous bacteria

abstract:
  We report molecular dynamics simulations of the segregation of two
overlapping chains in cylindrical confinement. We find that the entropic
repulsion between the chains can be sufficiently strong to cause segregation on
a time scale that is short compared to the one for diffusion. This result
implies that entropic driving forces are sufficiently strong to cause rapid
bacterial chromosome segregation.


title:
Absolute Galois acts faithfully on the components of the moduli space of
  surfaces: A Belyi-type theorem in higher dimension

abstract:
  Given an object over the algebraic closure Qbar of Q, there is often no
reason for invariants of the corresponding holomorphic object to be preserved
by the absolute Galois group Gal(Qbar/Q), and in general this is not true,
although it is sometimes surprising to observe in practice. The case of covers
of the projective line branched only over the points 0, 1, and infinity,
through Belyi's theorem, leads to Grothendieck's dessins d'enfants program for
understanding the absolute Galois group through its faithful action on such
covers. This note is motivated by Catanese's question about a
higher-dimensional analogue: does the absolute Galois group act faithfully on
the deformation equivalence classes of smooth surfaces? (These equivalence
classes are of course by definition the strongest deformation invariants.) We
give a short proof of a weaker result: the absolute Galois group acts
faithfully on the irreducible components of the moduli space of smooth surfaces
(of general type, canonically polarized). Bauer, Catanese, and Grunewald have
recently answered Catanese's original question using a different construction.


title: Characterization of polynomials

abstract:
  In 1954 it was proved if f is infinitely differentiable in the interval I and
some derivative (of order depending on x) vanishes at each x, then f is a
polynomial. Later it was generalized for multi-variable case. In this paper we
give an extension for distributions.


title: Slowly rotating pulsars

abstract:
  In the present work we investigate one possible variation on the usual static
pulsars: the inclusion of rotation. We use a formalism proposed by Hartle and
Thorne to calculate the properties of rotating pulsars with all possible
compositions. All calculations were performed for zero temperature and also for
fixed entropy equations of state.


title: The Phase Structure of the Polyakov--Quark-Meson Model

abstract:
  The relation between the deconfinement and chiral phase transition is
explored in the framework of an Polyakov-loop-extended two-flavor quark-meson
(PQM) model. In this model the Polyakov loop dynamics is represented by a
background temporal gauge field which also couples to the quarks. As a novelty
an explicit quark chemical potential and N_f-dependence in the Polyakov loop
potential is proposed by using renormalization group arguments. The behavior of
the Polyakov loop as well as the chiral condensate as function of temperature
and quark chemical potential is obtained by minimizing the grand canonical
thermodynamic potential of the system. The effect of the Polyakov loop dynamics
on the chiral phase diagram and on several thermodynamic bulk quantities is
presented.


title: XMM-Newton X-ray Observations of the Wolf-Rayet Binary System WR 147

abstract:
  We present results of a 20 ksec X-ray observation of the Wolf-Rayet (WR)
binary system WR 147 obtained with XMM-Newton. Previous studies have shown that
this system consists of a nitrogen-type WN8 star plus an OB companion whose
winds are interacting to produce a colliding wind shock. X-ray spectra from the
pn and MOS detectors confirm the high extinction reported from IR studies and
reveal hot plasma including the first detection of the Fe K-alpha line complex
at 6.67 keV. Spectral fits with a constant-temperature plane-parallel shock
model give a shock temperature kT(shock) = 2.7 keV [T(shock) ~ 31 MK], close to
but slightly hotter than the maximum temperature predicted for a colliding wind
shock. Optically thin plasma models suggest even higher temperatures, which are
not yet ruled out. The X-ray spectra are harder than can be accounted for using
2D numerical colliding wind shock models based on nominal mass-loss parameters.
Possible explanations include: (i) underestimates of the terminal wind speeds
or wind abundances, (ii) overly simplistic colliding wind models, or (iii) the
presence of other X-ray emission mechanisms besides colliding wind shocks.
Further improvement of the numerical models to include potentially important
physics such as non-equilibrium ionization will be needed to rigorously test
the colliding wind interpretation.


title:
A "diamond-ring" star: the unusual morphologic structure of a young
  (multiple?) object

abstract:
  We have observed IRAS06468-0325 obtaining optical and infrared images through
IJHKs and L' filters, K-band low-resolution spectroscopy, together with
millimetre line observations of CO and CS. IRAS06468-0325 has a very unusual
and enigmatic morphology with two components: a bright, close to point-like
source (the diamond) and a sharp-edge ring-like structure (the ring). The
source is not detected in the optical, at wavelengths shorter than the I-band.
The diamond is seen in all the imaging bands observed. The ring-like structure
in IRAS06468-0325 is clearly seen in the I, J, H, and Ks. It is not detected in
the L'-band image. Infrared colours of the diamond are compatible with excess
circumstellar emission and a young stellar nature. A strongly non-gaussian and
moderately bright CO(1-0) and {13}CO(2-1) lines are seen towards
IRAS06468-0325, at v_{LSR} of 30.5 km s{-1} (corresponding to a kinematic
distance of 3 kpc). Very weak C{18}O(2-1) and CS(2-1) lines were detected.
K-band spectra of the diamond and of the ring are similar both in the slope of
the continuum and in the presence of lines supporting the idea that the ring is
reflected light from the diamond. With the current data, a few different
scenarios are possible to explain the morphology of this object. However, the
available data seem to favour that the morphology of IRAS06468-0325 correspond
to a young stellar multiple system in a transient stage where a binary
co-exists with a circumbinary disc, similar to the case of GG Tau. In this
case, the sharpness of the well-defined ring may be due to tidal truncation
from dynamic interactions between components in a binary or multiple stellar
system. IRAS06468-0325 may be an important rare case that illustrates a
short-lived stage of the process of binary or multiple star formation.


title: Gibbs measures on Brownian currents

abstract:
  Motivated by applications to quantum field theory we consider Gibbs measures
for which the reference measure is Wiener measure and the interaction is given
by a double stochastic integral and a pinning external potential. In order
properly to characterize these measures through DLR equations, we are led to
lift Wiener measure and other objects to a space of configurations where the
basic observables are not only the position of the particle at all times but
also the work done by test vector fields. We prove existence and basic
properties of such Gibbs measures in the small coupling regime by means of
cluster expansion.


title: Alternative axiomatics and complexity of deliberative STIT theories

abstract:
  We propose two alternatives to Xu's axiomatization of the Chellas STIT. The
first one also provides an alternative axiomatization of the deliberative STIT.
The second one starts from the idea that the historic necessity operator can be
defined as an abbreviation of operators of agency, and can thus be eliminated
from the logic of the Chellas STIT. The second axiomatization also allows us to
establish that the problem of deciding the satisfiability of a STIT formula
without temporal operators is NP-complete in the single-agent case, and is
NEXPTIME-complete in the multiagent case, both for the deliberative and the
Chellas' STIT.


title:
A general approach to few-cycle intense laser interactions with complex
  atoms

abstract:
  A general {\it ab-initio} and non-perturbative method to solve the
time-dependent Schr\"odinger equation (TDSE) for the interaction of a strong
attosecond laser pulse with a general atom, i.e., beyond the models of
quasi-one-electron or quasi-two-electron targets, is described. The field-free
Hamiltonian and the dipole matrices are generated using a flexible $B$-spline
$R$-matrix method. This numerical implementation enables us to construct
term-dependent, non-orthogonal sets of one-electron orbitals for the bound and
continuum electrons. The solution of the TDSE is propagated in time using the
Arnoldi-Lanczos method, which does not require the diagonalization of any large
matrices. The method is illustrated by an application to the multi-photon
excitation and ionization of Ne atoms. Good agreement with $R$-matrix Floquet
calculations for the generalized cross sections for two-photon ionization is
achieved.


title: Finite Element Analysis of the Schroedinger Equation

abstract:
  The purpose of this work is to test the application of the finite element
method to quantum mechanical problems, in particular for solving the
Schroedinger equation.
  We begin with an overview of quantum mechanics, and standard numerical
techniques. We then give an introduction to finite element analysis using the
diffusion equation as an example. Three numerical time evolution methods are
considered: the (tried and tested) Crank-Nicolson method, the continuous
space-time method, and the discontinuous space-time method.


title: Neighbor Discovery in Wireless Networks:A Multiuser-Detection Approach

abstract:
  We examine the problem of determining which nodes are neighbors of a given
one in a wireless network. We consider an unsupervised network operating on a
frequency-flat Gaussian channel, where $K+1$ nodes associate their identities
to nonorthogonal signatures, transmitted at random times, synchronously, and
independently. A number of neighbor-discovery algorithms, based on different
optimization criteria, are introduced and analyzed. Numerical results show how
reduced-complexity algorithms can achieve a satisfactory performance.


title:
Line Emission in the Brightest Cluster Galaxies of the NOAO Fundamental
  Plane and Sloan Digital Sky Surveys

abstract:
  We examine the optical emission line properties of Brightest Cluster Galaxies
(BCGs) selected from two large, homogeneous datasets. The first is the X-ray
selected National Optical Astronomy Observatory Fundamental Plane Survey
(NFPS), and the second is the C4 catalogue of optically selected clusters built
from the Sloan Digital Sky Survey Data Release ~3 (SDSS DR3). Our goal is to
better understand the optical line emission in BCGs with respect to properties
of the galaxy and the host cluster. Throughout the analysis we compare the line
emission of the BCGs to that of a control sample made of the other bright
galaxies near the cluster centre. Overall, both the NFPS and SDSS show a modest
fraction of BCGs with emission lines (~15%). No trend in the fraction of
emitting BCGs as a function of galaxy mass or cluster velocity dispersion is
found. However we find that, for those BCGs found in cooling flow clusters,
71^{+9}_{-14}% have optical emission. Furthermore, if we consider only BCGs
within 50kpc of the X-ray centre of a cooling flow cluster, the emission-line
fraction rises further to 100^{+0}_{-15}%. Excluding the cooling flow clusters,
only ~10% of BCGs are line emitting, comparable to the control sample of
galaxies. We show that the physical origin of the emission line activity
varies: in some cases it has LINER-like line ratios, whereas in others it is a
composite of star-formation and LINER-like activity. We conclude that the
presence of emission lines in BCGs is directly related to the cooling of X-ray
gas at the cluster centre.


title: On Differential Sequences

abstract:
  We introduce the notion of Differential Sequences of ordinary differential
equations. This is motivated by related studies based on evolution partial
differential equations. We discuss the Riccati Sequence in terms of symmetry
analysis, singularity analysis and identification of the complete symmetry
group for each member of the Sequence. The singularity analysis reveals
considerable structure for the values of the coefficients of the leading-order
terms and resonances of the different principal branches. Full proofs of the
symmetry properties are performed for differential equations defined by their
recursion properties and not given in explicit form.


title: On the Smooth Feshbach-Schur Map

abstract:
  A new variant of the Feshbach map, called smooth Feshbach map, has been
introduced recently by Bach et al., in connection with the renormalization
analysis of non-relativistic quantum electrodynamics. We analyze and clarify
its algebraic and analytic properties, and we generalize it to non-selfadjoint
partition operators $\chi$ and $\chib$.


title: Electrically charged pulsars

abstract:
  n the present work we investigate one possible variation on the usual
electrically neutral pulsars: the inclusion of electric charge. We study the
effect of electric charge in pulsars assuming that the charge distribution is
proportional to the energy density. All calculations were performed for zero
temperature and fixed entropy equations of state.


title:
Nonlinear stage of the Benjamin-Feir instability: Three-dimensional
  coherent structures and rogue waves

abstract:
  A specific, genuinely three-dimensional mechanism of rogue wave formation, in
a late stage of the modulational instability of a perturbed Stokes deep-water
wave, is recognized through numerical experiments. The simulations are based on
fully nonlinear equations describing weakly three-dimensional potential flows
of an ideal fluid with a free surface in terms of conformal variables.
Spontaneous formation of zigzag patterns for wave amplitude is observed in a
nonlinear stage of the instability. If initial wave steepness is sufficiently
high ($ka>0.06$), these coherent structures produce rogue waves. The most tall
waves appear in ``turns'' of the zigzags. For $ka<0.06$, the structures decay
typically without formation of steep waves.


title:
The Growth of Black Holes and Their Host Spheroids in (Sub)mm-loud QSOs
  at High Redshift

abstract:
  We study the growth of black holes and stellar population in spheroids at
high redshift using several (sub)mm-loud QSO samples. Applying the same
criteria established in an earlier work, we find that, similar to IR QSOs at
low redshift, the far-infrared emission of these (sub)mm-loud QSOs mainly
originates from dust heated by starbursts. By combining low-z IR QSOs and
high-z (sub)mm-loud QSOs, we find a trend that the star formation rate
($\Mstardot$) increases with the accretion rate ($\Mdot$). We compare the
values of $\Mstardot/\Mdot$ for submm emitting galaxies (SMGs), far-infrared
ultraluminous/hyperluminous QSOs and typical QSOs, and construct a likely
evolution scenario for these objects. The (sub)mm-loud QSO transition phase has
both high $\Mdot$ and $\Mstardot$ and hence is important for establishing the
correlation between the masses of black holes and spheroids.


title: On C$^2$-smooth Surfaces of Constant Width

abstract:
  A number of results for C$^2$-smooth surfaces of constant width in Euclidean
3-space ${\mathbb{E}}^3$ are obtained. In particular, an integral inequality
for constant width surfaces is established. This is used to prove that the
ratio of volume to cubed width of a constant width surface is reduced by
shrinking it along its normal lines. We also give a characterization of
surfaces of constant width that have rational support function.
  Our techniques, which are complex differential geometric in nature, allow us
to construct explicit smooth surfaces of constant width in ${\mathbb{E}}^3$,
and their focal sets. They also allow for easy construction of tetrahedrally
symmetric surfaces of constant width.


title: Point Interaction Hamiltonians in Bounded Domains

abstract:
  Making use of recent techniques in the theory of selfadjoint extensions of
symmetric operators, we characterize the class of point interaction
Hamiltonians in a 3-D bounded domain with regular boundary. In the particular
case of one point interaction acting in the center of a ball, we obtain an
explicit representation of the point spectrum of the operator togheter with the
corresponding related eigenfunctions. These operators are used to build up a
model-system where the dynamics of a quantum particle depends on the state of a
quantum bit.


title: Chaos in the Stormer problem

abstract:
  We survey the few exact results on the Stormer problem describing the
dynamics of charged particles in the Earth magnetosphere. The analysis of this
system leads to the the conclusion that charged particles are trapped in the
Earth magnetosphere or escape to infinity, and the trapping region is bounded
by a torus-like surface, the Van Allen inner radiation belt. In the trapping
region, the motion of the charged particles can be periodic, quasi-period or
chaotic. The three main effects observed in the Earth magnetosphere, radiation
belts, radiation aurorae and South Atlantic anomaly, are described in the
framework described here. We discuss some new mathematical problems suggested
by the analysis of the Stormer problem.


title: Equifocality of a singular riemannian foliation

abstract:
  A singular foliation on a complete riemannian manifold M is said to be
riemannian if each geodesic that is perpendicular at one point to a leaf
remains perpendicular to every leaf it meets. We prove that the regular leaves
are equifocal, i.e., the end point map of a normal foliated vector field has
constant rank. This implies that we can reconstruct the singular foliation by
taking all parallel submanifolds of a regular leaf with trivial holonomy. In
addition, the end point map of a normal foliated vector field on a leaf with
trivial holonomy is a covering map. These results generalize previous results
of the authors on singular riemannian foliations with sections.


title:
An analysis of celestial pole offset observations in the free core
  nutation frequency band

abstract:
  In this study, three empirical Free Core Nutation (FCN) models developed to
the present time, MHB2000, Malkin's and Lambert's ones, are compared on the
basis of representation of variations of the FCN amplitude and phase predicted
by these models. It is possible to conclude, that the model of the author
provides the most realistic representation of the FCN variations. However, the
specified models are based on representation about single FCN rotational mode.
At the same time, some results of processing of the VLBI observations made
during last years, specify possible presence of two close FCN periods. A
theoretical explanation to presence of a second FCN frequency FCN has been
given by G. Krasinsky in his theory of rotation of the Earth with two-layer
liquid core, ERA2005. In the present work, for more detailed studying this
phenomenon, the IVS time series of celestial pole offset, and also those
predicted by the ERA2005 theory, have been investigated by means of several
statistical methods which confidently show presence of two fluctuations in
nutational movement of an Earth's rotation axis with the periods about -452 and
-410 solar days.


title:
Quantum Hacking: Experimental demonstration of time-shift attack against
  practical quantum key distribution systems

abstract:
  Quantum key distribution (QKD) systems can send signals over more than 100 km
standard optical fiber and are widely believed to be secure. Here, we show
experimentally for the first time a technologically feasible attack, namely the
time-shift attack, against a commercial QKD system. Our result shows that,
contrary to popular belief, an eavesdropper, Eve, has a non-negligible
probability (~4%) to break the security of the system. Eve's success is due to
the well-known detection efficiency loophole in the experimental testing of
Bell inequalities. Therefore, the detection efficiency loophole plays a key
role not only in fundamental physics, but also in technological applications
such as QKD.


title: Symmetrical invariants of some modular Lie algebras of Cartan type

abstract:
  Let $L$ be one of the finite dimensional Lie algebras $W_n({\bf m}),$
$S_n({\bf m}),$ $ H_n({\bf m})$ of Cartan type over an algebraically closed
field of prime characteristic $p>0.$ For an elements $F$ of the symmetrical
algebra $S(L)$ we found necessary and sufficient condition in order to the
element $ad(\partial_1)^{p^{m_1}-1} ad(\partial_2)^{p^{m_2}-1}...
ad(\partial_n)^{p^{m_n}-1}(F)$ belongs to the symmetrical invariants algebra
$S(L)^L.$ Also, for $p=3,5$ the algebra of symmetrical invariants
$S(H_2)^{H_2}$ is calculated in explicit way.


title: Vacuum Cherenkov radiation in spacelike Maxwell-Chern-Simons theory

abstract:
  A detailed analysis of vacuum Cherenkov radiation in spacelike
Maxwell-Chern-Simons (MCS) theory is presented. A semiclassical treatment
reproduces the leading terms of the tree-level result from quantum field
theory. Moreover, certain quantum corrections turn out to be suppressed for
large energies of the charged particle, for example, the quantum corrections to
the classical MCS Cherenkov angle. It is argued that MCS-theory Cherenkov
radiation may, in principle, lead to anisotropy effects for ultra-high-energy
cosmic rays (UHECRs). In addition, a qualitative discussion of vacuum Cherenkov
radiation from a modified-Maxwell term in the action is given, together with
UHECR bounds on some of its dimensionless "coupling constants."


title: The moduli space of cubic fourfolds

abstract:
  We describe the GIT compactification of the moduli space of cubic fourfolds,
with a special emphasis on the role played by singularities. Our main result is
that a cubic fourfold with only isolated simple (A-D-E) singularities is GIT
stable. Conversely, with some minor exceptions, the stability for cubic
fourfolds is characterized by this condition.


title:
Millimeter dust continuum emission unveiling the true mass of giant
  molecular clouds in the Small Magellanic Cloud

abstract:
  CO observations have been so far the best way to trace molecular gas in
external galaxies, but at low metallicity the gas mass deduced could be largely
underestimated. At present, the kinematic information of CO data cubes are used
to estimate virial masses and trace the total mass of the molecular clouds.
Millimeter dust emission can also be used as a dense gas tracer and could
unveil H2 envelopes lacking CO. These different tracers must be compared in
different environments. This study compares virial masses to masses deduced
from millimeter emission, in two GMC samples: the local molecular clouds in our
Galaxy and their equivalents in the Small Magellanic Cloud (SMC), one of the
nearest low metallicity dwarf galaxy. In our Galaxy, mass estimates deduced
from millimeter emission are consistent with masses deduced from gamma ray
analysis and trace the total mass of the clouds. Virial masses are
systematically larger (twice on average) than mass estimates from millimeter
dust emission. This difference decreases toward high masses and has already
been reported in previous studies. In the SMC however, molecular cloud masses
deduced from SIMBA millimeter observations are systematically higher (twice on
average for conservative values of the dust to gas ratio and dust emissivity)
than the virial masses from SEST CO observations. The observed excess can not
be accounted for by any plausible change of dust properties. Taking a general
form for the virial theorem, we show that a magnetic field strength of ~15
micro Gauss in SMC clouds could provide additional support to the clouds and
explain the difference observed. Masses of SMC molecular clouds have therefore
been underestimated so far. Magnetic pressure may contribute significantly to
their support.


title: Natural Realizations of Seesaw in Mini-Warped Minimal SO(10)

abstract:
  The minimal SUSY SO(10) GUT models with {\bf 10}, {\bf 126} and {\bf 210}
Higgs and only renormalizable couplings has been shown to provide a simple way
to understand the neutrino mixings as well as the ratio $\Delta
m^2_\odot/\Delta m^2_A$ in terms of quark mixing parameter $\theta_{Cabibbo}$,
provided neutrino masses are described by type II seesaw formula. However, in
this minimal picture, it is impossible to realize type II dominance with
renormalizable couplings in 4-dimensions. We show that this problem can be
cured by embedding this model into a warped 5-dimensional space time with
warping between the Planck and the GUT scale, where both type II as well as
mixed seesaw formulae can be realized in a natural manner without expanding the
Higgs sector. These models also avoid the possible problem of threshold effects
associated with large Higgs representations since the theory above the GUT
scale is now strongly coupled.


title: Python Unleashed on Systems Biology

abstract:
  We have built an open-source software system for the modeling of biomolecular
reaction networks, SloppyCell, which is written in Python and makes substantial
use of third-party libraries for numerics, visualization, and parallel
programming. We highlight here some of the powerful features that Python
provides that enable SloppyCell to do dynamic code synthesis, symbolic
manipulation, and parallel exploration of complex parameter spaces.


title: Spectrum of Yang-Mills Theory in D=3+1

abstract:
  We give a comparison of the spectrum of Yang-Mills theory in $D=3+1$,
recently derived with a strong coupling expansion, with lattice data. We verify
excellent agreement also for 2$^{++}$ glueball. A deep analogy with the $D=2+1$
case is obtained and a full quantum theory of this approach is also given.


title:
Nearest-neigbor spacing distributions of the beta-Hermite ensemble of
  random matrices

abstract:
  The distributions of the spacing s between nearest-neighbor levels of
unfolded spectra of random matrices from the beta-Hermite ensemble (beta-HE) is
investigated by Monte Carlo simulations. The random matrices from the beta-HE
are real-symmetric and tridiagonal where beta, which can take any positive
value, is the reciprocal of the temperature in the classical electrostatic
interpretation of eigenvalues. Generalized gamma distributions are shown to be
excellent approximations of the nearest-neighbor spacing (NNS) distributions
for any beta while being still simple. They account both for the level
repulsion when s tends to zero and for the whole shape of the NNS distributions
in the range of s which is accessible to experiment or to most numerical
simulations. The exact NNS distribution of the GOE (beta=1) is in particular
significantly better described by a generalized gamma distribution than it is
by the Wigner surmise while the best generalized gamma approximation coincides
essentially with the Wigner surmise for beta larger than ~2. The distributions
of the minimum NN spacing between eigenvalues of matrices from the beta-HE,
obtained both from as-calculated eigenvalues and from unfolded eigenvalues are
Brody distributions.


title: Impedance spectroscopy of epitaxial multiferroic thin films

abstract:
  Temperature dependent impedance spectroscopy enables the many contributions
to the dielectric and resistive properties of condensed matter to be
deconvoluted and characterized separately. We have achieved this for
multiferroic epitaxial thin films of BiFeO3 (BFO) and BiMnO3 (BMO), key
examples of materials with strong magneto-electric coupling. We demonstrate
that the true film capacitance of the epitaxial layers is similar to that of
the electrode interface, making analysis of capacitance as a function of film
thickness necessary to achieve deconvolution. We modeled non-Debye impedance
response using Gaussian distributions of relaxation times and reveal that
conventional resistivity measurements on multiferroic layers may be dominated
by interface effects. Thermally activated charge transport models yielded
activation energies of 0.60 eV +- 0.05 eV (BFO) and 0.25 eV +- 0.03 eV (BMO),
which is consistent with conduction dominated by oxygen vacancies (BFO) and
electron hopping (BMO). The intrinsic film dielectric constants were determined
to be 320 +- 75 (BFO) and 450 +- 100 (BMO).


title:
Effect of beta-Dystroglycan Processing on Utrophin / DP116 Anchorage in
  Normal and MDX Mouse Schwann Cell Membrane

abstract:
  In the peripheral nervous system, utrophin and the short dystrophin isoform
(Dp116) are co-localized at the outermost layer of the myelin sheath of nerve
fibers; together with the dystroglycan complex. In peripheral nerve, matrix
metalloproteinase (MMP) creates a 30 kDa fragment of beta-dystroglycan, leading
to a disruption of the link between the extracellular matrix and the cell
membrane. Here we asked if the processing of the beta-dystroglycan could
influence the anchorage of Dp116 or/and utrophin in normal and mdx Schwann cell
membrane. We showed that MMP-9 was more activated in mdx nerve than in
wild-type one. This activation leads to an accumulation of the 30 kDa
beta-dystroglycan isoform and have an impact on the anchorage of Dp116 and
utrophin isoforms in mdx Schwann cells membrane. Our results showed that Dp116
had greater affinity to the full length form of beta-dystroglycan than the 30
kDa form. Moreover, we showed for the first time that the short isoform of
utrophin (Up71) was over-expressed in mdx Schwann cells compared to wild-type.
In addition, this utrophin isoform (Up71) seems to have greater affinity to the
30 kDa beta-dystroglycan which could explain a more stabilization of this 30
kDa at the membrane compartment. Our results highlight the potential
participation of the short utrophin isoform and the cleaved form of
beta-dystroglycan in mdx Schwann cell membrane architecture.


title: Efficiency and versatility of distal multisite transcription regulation

abstract:
  Transcription regulation typically involves the binding of proteins over long
distances on multiple DNA sites that are brought close to each other by the
formation of DNA loops. The inherent complexity of the assembly of regulatory
complexes on looped DNA challenges the understanding of even the simplest
genetic systems, including the prototypical lac operon. Here we implement a
scalable quantitative computational approach to analyze systems regulated
through multiple DNA sites with looping. Our approach applied to the lac operon
accurately predicts the transcription rate over five orders of magnitude for
wild type and seven mutants accounting for all the combinations of deletions of
the three operators. A quantitative analysis of the model reveals that the
presence of three operators provides a mechanism to combine robust repression
with sensitive induction, two seemingly mutually exclusive properties that are
required for optimal functioning of metabolic switches.


title: Static forms of the Robertson-Walker spacetimes

abstract:
  It is shown that only the maximally-symmetric spacetimes can be expressed in
both the Robertson-Walker form and in static form - there are no other static
forms of the Robertson-Walker spacetimes. All possible static forms of the
metric of the maximally-symmetric spacetimes are presented as a table. The
findings are generalized to apply to functionally more general spacetimes: it
is shown that the maximally symmetric spacetimes are also the only spacetimes
that can be written in both orthogonal-time isotropic form and in static form.


title: Rotation and activity of pre-main-sequence stars

abstract:
  We present a study of rotation (vsini) and chromospheric activity (Halpha EW)
based on an extensive set of high-resolution optical spectra obtained with MIKE
on the 6.5m Magellan Clay telescope. Our targets are 74 F-M dwarfs in the young
stellar associations Eta Cha, TW Hydrae, Beta Pic, and Tuc-Hor, spanning ages
from 6 to 30 Myr. While the Halpha EW for most F and G stars are consistent
with pure photospheric absorption, most K and M stars show chromospheric
emission. By comparing Halpha EW in our sample to results in the literature, we
see a clear evolutionary sequence: Chromospheric activity declines steadily
from the T Tauri phase to the main sequence. Using activity as an age
indicator, we find a plausible age range for the Tuc-Hor association of 10-40
Myr. Between 5 and 30 Myr, we do not see evidence for rotational braking in the
total sample, thus angular momentum is conserved, in contrast to younger stars.
This difference indicates a change in the rotational regulation at 5-10 Myr,
possibly because disk braking cannot operate longer than typical disk
lifetimes, allowing the objects to spin up. The rotation-activity relation is
flat in our sample; in contrast to main-sequence stars, there is no linear
correlation for slow rotators. We argue that this is because young stars
generate their magnetic fields in a fundamentally different way from
main-sequence stars, and not just the result of a saturated solar-type dynamo.
By comparing our rotational velocities with published rotation periods for a
subset of stars, we determine ages of 13 (7-20) Myr and 9 (7-17} Myr for the
Eta Cha and TWA associations, respectively, consistent with previous estimates.
Thus we conclude that stellar radii from evolutionary models by Baraffe et al.
(1998) are in agreement with the observed radii within +-15%. (abridged)


title: Radial density profiles of time-delay lensing galaxies

abstract:
  We present non-parametric radial mass profiles for ten QSO strong lensing
galaxies. Five of the galaxies have profiles close to $\rho(r)\propto r^{-2}$,
while the rest are closer to r^{-1}, consistent with an NFW profile. The former
are all relatively isolated early-types and dominated by their stellar light.
The latter --though the modeling code did not know this-- are either in
clusters, or have very high mass-to-light, suggesting dark-matter dominant
lenses (one is a actually pair of merging galaxies). The same models give
$H_0^{-1} = 15.2_{-1.7}^{+2.5}\Gyr$ ($H_0 = 64_{-9}^{+8} \legacy$), consistent
with a previous determination. When tested on simulated lenses taken from a
cosmological hydrodynamical simulation, our modeling pipeline recovers both H_0
and $\rho(r)$ within estimated uncertainties. Our result is contrary to some
recent claims that lensing time delays imply either a low H_0 or galaxy
profiles much steeper than r^{-2}. We diagnose these claims as resulting from
an invalid modeling approximation: that small deviations from a power-law
profile have a small effect on lensing time-delays. In fact, as we show using
using both perturbation theory and numerical computation from a
galaxy-formation simulation, a first-order perturbation of an isothermal lens
can produce a zeroth-order change in the time delays.


title: 2D Path Solutions from a Single Layer Excitable CNN Model

abstract:
  An easily implementable path solution algorithm for 2D spatial problems,
based on excitable/programmable characteristics of a specific cellular
nonlinear network (CNN) model is presented and numerically investigated. The
network is a single layer bioinspired model which was also implemented in CMOS
technology. It exhibits excitable characteristics with regionally bistable
cells. The related response realizes propagations of trigger autowaves, where
the excitable mode can be globally preset and reset. It is shown that, obstacle
distributions in 2D space can also be directly mapped onto the coupled cell
array in the network. Combining these two features, the network model can serve
as the main block in a 2D path computing processor. The related algorithm and
configurations are numerically experimented with circuit level parameters and
performance estimations are also presented. The simplicity of the model also
allows alternative technology and device level implementation, which may become
critical in autonomous processor design of related micro or nanoscale robotic
applications.


title:
Atmospheric Dynamics of Short-period Extra Solar Gas Giant Planets I:
  Dependence of Night-Side Temperature on Opacity

abstract:
  More than two dozen short-period Jupiter-mass gas giant planets have been
discovered around nearby solar-type stars in recent years, several of which
undergo transits, making them ideal for the detection and characterization of
their atmospheres. Here we adopt a three-dimensional radiative hydrodynamical
numerical scheme to simulate atmospheric circulation on close-in gas giant
planets. In contrast to the conventional GCM and shallow water algorithms, this
method does not assume quasi hydrostatic equilibrium and it approximates
radiation transfer from optically thin to thick regions with flux-limited
diffusion. In the first paper of this series, we consider
synchronously-spinning gas giants. We show that a full three-dimensional
treatment, coupled with rotationally modified flows and an accurate treatment
of radiation, yields a clear temperature transition at the terminator. Based on
a series of numerical simulations with varying opacities, we show that the
night-side temperature is a strong indicator of the opacity of the planetary
atmosphere. Planetary atmospheres that maintain large, interstellar opacities
will exhibit large day-night temperature differences, while planets with
reduced atmospheric opacities due to extensive grain growth and sedimentation
will exhibit much more uniform temperatures throughout their photosphere's. In
addition to numerical results, we present a four-zone analytic approximation to
explain this dependence.


title: Hadronization in semi-inclusive deep-inelastic scattering on nuclei

abstract:
  A series of semi-inclusive deep-inelastic scattering measurements on
deuterium, helium, neon, krypton, and xenon targets has been performed in order
to study hadronization. The data were collected with the HERMES detector at the
DESY laboratory using a 27.6 GeV positron or electron beam. Hadron
multiplicities on nucleus A relative to those on the deuteron, R_A^h, are
presented for various hadrons (\pi^+, \pi^-, \pi^0, K^+, K^-, p, and \bar{p})
as a function of the virtual-photon energy \nu, the fraction z of this energy
transferred to the hadron, the photon virtuality Q^2, and the hadron transverse
momentum squared p_t^2. The data reveal a systematic decrease of R_A^h with the
mass number A for each hadron type h. Furthermore, R_A^h increases (decreases)
with increasing values of \nu (z), increases slightly with increasing Q^2, and
is almost independent of p_t^2, except at large values of p_t^2. For pions
two-dimensional distributions also are presented. These indicate that the
dependences of R_A^{\pi} on \nu and z can largely be described as a dependence
on a single variable L_c, which is a combination of \nu and z. The dependence
on L_c suggests in which kinematic conditions partonic and hadronic mechanisms
may be dominant. The behaviour of R_A^{\pi} at large p_t^2 constitutes
tentative evidence for a partonic energy-loss mechanism. The A-dependence of
R_A^h is investigated as a function of \nu, z, and of L_c. It approximately
follows an A^{\alpha} form with \alpha \approx 0.5 - 0.6.


title:
Constraining Models of Neutrino Mass and Neutrino Interactions with the
  Planck Satellite

abstract:
  In several classes of particle physics models -- ranging from the classical
Majoron models, to the more recent scenarios of late neutrino masses or
Mass-Varying Neutrinos -- one or more of the neutrinos are postulated to couple
to a new light scalar field. As a result of this coupling, neutrinos in the
early universe instead of streaming freely could form a self-coupled fluid,
with potentially observable signatures in the Cosmic Microwave Background and
the large scale structure of the universe. We re-examine the constraints on
this scenario from the presently available cosmological data and investigate
the sensitivity expected from the Planck satellite. In the first case, we find
that the sensitivity strongly depends on which piece of data is used. The SDSS
Main sample data, combined with WMAP and other data, disfavors the scenario of
three coupled neutrinos at about the 3.5$\sigma$ confidence level, but also
favors a high number of freely streaming neutrinos, with the best fit at 5.2.
If the matter power spectrum is instead taken from the SDSS Large Red Galaxy
sample, best fit point has 2.5 freely streaming neutrinos, but the scenario
with three coupled neutrinos becomes allowed at $2\sigma$. In contrast, Planck
alone will exclude even a single self-coupled neutrino at the $4.2\sigma$
confidence level, and will determine the total radiation at CMB epoch to
$\Delta N_\nu^{eff} = ^{+0.5}_{-0.3}$ ($1\sigma$ errors). We investigate the
robustness of this result with respect to the details of Planck's detector.
This sensitivity to neutrino free-streaming implies that Planck will be capable
of probing a large region of the Mass-Varying Neutrino parameter space. Planck
may also be sensitive to a scale of neutrino mass generation as high as 1 TeV.


title: Non-geometric fluxes as supergravity backgrounds

abstract:
  We consider examples of D=4 string theory vacua which, although globally
non-geometric, admit a local description in terms of D=10 supergravity
backgrounds. We analyze such backgrounds and find that the supersymmetry
spinors vary non-trivially along the internal manifold, reproducing the
interpolating supergravity solutions found by Frey and Grana. Finally, we
propose a simple, local expression for non-geometric fluxes in terms of the
internal spinors of the compactification.


title:
Forward and non-forward symplectic integrators in solving classical
  dynamics problems

abstract:
  Forward time step integrators are splitting algorithms with only positive
splitting coefficients. When used in solving physical evolution equations,
these positive coefficients correspond to positive time steps. Forward
algorithms are essential for solving time-irreversible equations that cannot be
evolved using backward time steps. However, forward integrators are also better
in solving time-reversible equations of classical dynamics by tracking as
closely as possible the physical trajectory. This work compares in detail
various forward and non-forward fourth-order integrators using three, fourth,
five and six force evaluations. In the case of solving the 2D Kepler orbit, all
non-forward integrators are optimized by simply minimizing the size of their
backward time steps.


title: Nonradiative DKR processes: revisiting the theory. I. Unimode model

abstract:
  We are revisiting the efficiency problem of DKR nonradiative transitions at
local electronic centers in polarizable solids. Following a brief survey, we
formulate the general rate equations thereby defining the microscopic
parameters controlling the nonradiative deexcitation. We also reproduce the
quantum mechanical expressions for the energy conserving "horizontal transfer
rates" to compare with the "verical transition rates" at various vibronic
energy levels.


title: Matter-wave interference in s-wave and p-wave Fermi condensates

abstract:
  We discuss the time evolution and matter-wave interference of Fermi
condensates on the BEC side of Feshbach resonances for s and p-wave
superfluids, upon release from harmonic traps. In swave systems, where the
order parameter is a complex scalar, we find that the interference patterns
depend on the relative phase of the order parameters of the condensates. In
p-wave systems involving the mixture of two-hyperfine states, we show that the
interference pattern exhibits a polarization effect depending on the relative
orientation of the two vector order parameters. Lastly, we also point out that
p-wave Fermi condensates exhibit an anisotropic expansion, reflecting the
spatial anisotropy of the underlying interaction between fermions and the
orbital nature of the vector order parameter. Potential applications of our
results include systems of ultra-cold atoms that exhibit p-wave Feshbach
resonances such as 6Li or 40K.


title:
Feynman-Weinberg Quantum Gravity and the Extended Standard Model as a
  Theory of Everything

abstract:
  I argue that the (extended) Standard Model (SM) of particle physics and the
renormalizable Feynman-Weinberg theory of quantum gravity comprise a theory of
everything. I show that imposing the appropriate cosmological boundary
conditions make the theory finite. The infinities that are normally
renormalized away and the series divergence infinities are both eliminated by
the same mechanism. Furthermore, this theory can resolve the horizon, flatness,
and isotropy problems of cosmology. Joint mathematical consistency naturally
yields a scale-free, Gaussian, adiabatic perturbation spectrum, and more matter
than antimatter. I show that mathematical consistency of the theory requires
the universe to begin at an initial singularity with a pure $SU(2)_L$ gauge
field. I show that quantum mechanics requires this field to have a Planckian
spectrum whatever its temperature. If this field has managed to survive
thermalization to the present day, then it would be the CMBR. If so, then we
would have a natural explanation for the dark matter and the dark energy. I
show that isotropic ultrahigh energy (UHE) cosmic rays are explained if the
CMBR is a pure $SU(2)_L$ gauge field. The $SU(2)_L$ nature of the CMBR may have
been seen in the Sunyaev-Zel'dovich effect. I propose several simple
experiments to test the hypothesis.


title: Tachyons and superluminal boosts

abstract:
  Some arguments in favour of the existence of tachyons and extensions of the
Lorentz Group are presented. On the former, it is observed that with a slight
modification to standard electromagnetic theory a single superluminal charge
will bind to itself in a self-sustaining circular orbit, suggestive of a
(modified) electromagnetic interpretation of the strong force. Symmetries in
that theory are used in the subsequent analysis as a starting point in the
search for physically-motivated extensions of the Lorentz Group. There is some
discussion of the validity of imaginary coordinates in superluminal
transformations of frame. The article concludes with some speculation on the
implications for faster-than light travel.


title: Zeroth Hochschild homology of preprojective algebras over the integers

abstract:
  We determine the Z-module structure of the preprojective algebra and its
zeroth Hochschild homology, for any non-Dynkin quiver (and hence the structure
working over any base commutative ring, of any characteristic). This answers
(and generalizes) a conjecture of Hesselholt and Rains, producing new
$p$-torsion classes in degrees 2p^l, l >= 1, We relate these classes by p-th
power maps and interpret them in terms of the kernel of Verschiebung maps from
noncommutative Witt theory. An important tool is a generalization of the
Diamond Lemma to modules over commutative rings, which we give in the appendix.
  In the previous version, additional results are included, such as: the
Poisson center of $\text{Sym } HH_0(\Pi)$ for all quivers, the BV algebra
structure on Hochschild cohomology, including how the Lie algebra structure
$HH_0(\Pi_Q)$ naturally arises from it, and the cyclic homology groups of
$\Pi_Q$.


title: Un-renormalized Classical Electromagnetism

abstract:
  This paper follows in the tradition of direct-action versions of
electromagnetism having the aim of avoiding a balance of infinities wherein a
mechanical mass offsets an infinite electromagnetic mass so as to arrive at a
finite observed value. Given that, in this respect the direct-action approached
ultimately failed because its initial exclusion of self-action was found to be
untenable in the relativistic domain, this paper continues the tradition
considering instead a version of electromagnetism wherein mechanical action is
excluded and self-action is retained. It is shown that the resulting theory is
effectively interacting due to the presence of infinite forces. A vehicle for
the investigation is a pair of classical point charges in a positronium-like
arrangement for which the orbits are found to be self-sustaining and naturally
quantized.


title:
Local structure of the moduli space of K3 surfaces over finite
  characteristic

abstract:
  Let k be a perfect field of characteristic p > 2. In this note, we show that
the local moduli space of a non-supersingular K3 surface over k with trivial
deformation of the associated enlarged formal Brauer group admits a natural
p-divisible formal group structure.


title: Reduced bias nonparametric lifetime density and hazard estimation

abstract:
  Kernel-based nonparametric hazard rate estimation is considered with a
special class of infinite-order kernels that achieves favorable bias and mean
square error properties. A fully automatic and adaptive implementation of a
density and hazard rate estimator is proposed for randomly right censored data.
Careful selection of the bandwidth in the proposed estimators yields estimates
that are more efficient in terms of overall mean squared error performance, and
in some cases achieves a nearly parametric convergence rate. Additionally,
rapidly converging bandwidth estimates are presented for use in second-order
kernels to supplement such kernel-based methods in hazard rate estimation.
Simulations illustrate the improved accuracy of the proposed estimator against
other nonparametric estimators of the density and hazard function. A real data
application is also presented on survival data from 13,166 breast carcinoma
patients.


title:
Production of TeV gamma-radiation in the vicinity of the supermassive
  black hole in the giant radiogalaxy M87

abstract:
  Although the giant radiogalaxy M 87 harbors many distinct regions of
broad-band nonthermal emission, the recently reported fast variability of TeV
gamma rays from M 87 on a timescale of days strongly constrains the range of
speculations concerning the possible sites and scenarios of particle
acceleration responsible for the observed TeV emission. A natural production
site of this radiation is the immediate vicinity of the central supermassive
mass black hole (BH). Because of the low bolometric luminosity, the nucleus of
M 87 is effectively transparent for gamma rays up to energy of 10 TeV, which
makes this source an ideal laboratory for study of particle acceleration
processes close to the BH event horizon. We critically analyse different
possible radiation mechanisms in this region, and argue that the observed very
high-energy gamma ray emission can be explained by the inverse Compton emission
of ultrarelativistic electron-positron pairs produced through the development
of an electromagnetic cascade in the BH magnetosphere. We demonstrate, through
detailed numerical calculations of acceleration and radiation of electrons in
the magnetospheric vacuum gap, that this ``pulsar magnetosphere like'' scenario
can satisfactorily explain the main properties of TeV gamma-ray emission of M
87.


title: Glicci simplicial complexes

abstract:
  One of the main open questions in liaison theory is whether every homogeneous
Cohen-Macaulay ideal in a polynomial ring is glicci, i.e. if it is in the
G-liaison class of a complete intersection. We give an affirmative answer to
this question for Stanley-Reisner ideals defined by simplicial complexes that
are weakly vertex-decomposable. This class of complexes includes matroid,
shifted and Gorenstein complexes respectively. Moreover, we construct a
simplicial complex which shows that the property of being glicci depends on the
characteristic of the base field. As an application of our methods we establish
new evidence for two conjectures of Stanley on partitionable complexes and on
Stanley decompositions.


title: Symmetry Breaking in Linearly Coupled Dynamical Lattices

abstract:
  We examine one- and two-dimensional (1D and 2D) models of linearly coupled
lattices of the discrete-nonlinear-Schr{\"{o}}dinger type. Analyzing ground
states of the systems with equal powers in the two components, we find a
symmetry-breaking phenomenon beyond a critical value of the squared $l^2$-norm.
Asymmetric states, with unequal powers in their components, emerge through a
subcritical pitchfork bifurcation, which, for very weakly coupled lattices,
changes into a supercritical one. We identify the stability of various solution
branches. Dynamical manifestations of the symmetry breaking are studied by
simulating the evolution of the unstable branches. The results present the
first example of spontaneous symmetry breaking in 2D lattice solitons. This
feature has no counterpart in the continuum limit, because of the collapse
instability in the latter case.


title: Inflationary Cosmology Connecting Dark Energy and Dark Matter

abstract:
  Kination dominated quintessence models of dark energy have the intriguing
feature that the relic abundance of thermal cold dark matter can be
significantly enhanced compared to the predictions from standard cosmology.
Previous treatments of such models do not include a realistic embedding of
inflationary initial conditions. We remedy this situation by constructing a
viable inflationary model in which the inflaton and quintessence field are the
same scalar degree of freedom. Kination domination is achieved after inflation
through a strong push or "kick" of the inflaton, and sufficient reheating can
be achieved depending on model parameters. This allows us to explore both
model-dependent and model-independent cosmological predictions of this
scenario. We find that measurements of the B-mode CMB polarization can rule out
this class of scenarios almost model independently. We also discuss other
experimentally accessible signatures for this class of models.


title: Milnor Invariants for Spatial Graphs

abstract:
  Link homotopy has been an active area of research for knot theorists since
its introduction by Milnor in the 1950s. We introduce a new equivalence
relation on spatial graphs called component homotopy, which reduces to link
homotopy in the classical case. Unlike previous attempts at generalizing link
homotopy to spatial graphs, our new relation allows analogues of some standard
link homotopy results and invariants.
  In particular we can define a type of Milnor group for a spatial graph under
component homotopy, and this group determines whether or not the spatial graph
is splittable. More surprisingly, we will also show that whether the spatial
graph is splittable up to component homotopy depends only on the link homotopy
class of the links contained within it. Numerical invariants of the relation
will also be produced.


title: Sample size cognizant detection of signals in white noise

abstract:
  The detection and estimation of signals in noisy, limited data is a problem
of interest to many scientific and engineering communities. We present a
computationally simple, sample eigenvalue based procedure for estimating the
number of high-dimensional signals in white noise when there are relatively few
samples. We highlight a fundamental asymptotic limit of sample eigenvalue based
detection of weak high-dimensional signals from a limited sample size and
discuss its implication for the detection of two closely spaced signals.
  This motivates our heuristic definition of the 'effective number of
identifiable signals.' Numerical simulations are used to demonstrate the
consistency of the algorithm with respect to the effective number of signals
and the superior performance of the algorithm with respect to Wax and Kailath's
"asymptotically consistent" MDL based estimator.


title:
Discovery of new faint radio emission on 8$\arcdeg$ to 3$\arcmin$ scales
  in the Coma field, and some Galactic and extragalactic implications

abstract:
  We present a deep, 8$\degr$ diameter, 0.4 GHz radio image using a first time
combination of the NAIC Arecibo 305-m telescope in Puerto Rico, and the
wide-angle interferometer at the Dominion Radio Astrophysical Observatory at
Penticton, Canada. Our observations are centered on the Coma Cluster of
galaxies in the ``Great Wall'' of galaxies near the North Galactic Pole. The
complementary nature of these two instruments enables us to produce a
distortion-free image that is sensitive to radiation on scales from 8$\degr$
down to that of an individual galaxy halo at the 100 Mpc distance of the Great
Wall. Newly revealed patches of distributed radio ``glow'' are seen well above
the detection limit. One prominent such area coincides with groupings of radio
galaxies near the Coma cluster, and indicates intergalactic IGM magnetic fields
in the range 0.2 to 0.4 $\mu$G on scales of up to $\sim$ 4 Mpc. Other patches
of diffuse emission, not previously explored at these high latitudes on
arcminute scales, probably contain Galactic ``cirrus''. A striking
anticorrelation is found between low-level diffuse radio glow and some regions
of enhanced optical galaxy surface density, suggesting that cosmological Large
Scale Structure (LSS), normally defined by the baryonic (or dark) matter
density, is not {\it uniquely} traced by faint continuum radio glow. Rather,
intergalactic diffuse synchrotron radiation represents IGM magnetic and Cosmic
ray energy density, instead of matter density. The diffuse, arcminute-level
structures over a large region of sky are potentially important pathfinders to
CMB foreground radiation on high multipole scales.


title:
Dynamical "breaking" of time reversal symmetry and converse quantum
  ergodicity

abstract:
  It is a common assumption that quantum systems with time reversal invariance
and classically chaotic dynamics have energy spectra distributed according to
GOE-type of statistics. Here we present a class of systems which fail to follow
this rule. We show that for convex billiards of constant width with time
reversal symmetry and "almost" chaotic dynamics the energy level distribution
is of GUE-type. The effect is due to the lack of ergodicity in the "momentum"
part of the phase space and, as we argue, is generic in two dimensions.
Besides, we show that certain billiards of constant width in multiply connected
domains are of interest in relation to the quantum ergodicity problem. These
billiards are quantum ergodic, but not classically ergodic.


title:
Residual correlations between decay products of $\pi^0\pi^0$ and
  $p\Sigma^0$ systems

abstract:
  Residual correlations between decay products due to a combination of both
correlations between parents at small relative velocities and small decay
momenta are discussed. Residual correlations between photons from pion decays
are considered as a new possible source of information on direct photon
fraction. Residual correlations in $p\gamma$ and $p\Lambda$ systems due to
$p\Sigma^0$ interaction in final state are predicted based on the $p\Sigma^0$
low energy scattering parameters deduced from the spin-flavour SU$_6$ model by
Fujiwara et al. including effective meson exchange potentials and explicit
flavour symmetry breaking to reproduce the properties of the two-nucleon system
and the low-energy hyperon-nucleon cross section data. The $p\gamma_{\Sigma^0}$
residual correlation is concentrated at $k^* \approx 70$ Mev/$c$ and its shape
and intensity appears to be sensitive to the scattering parameters and
space-time dimensions of the source. The $p\Lambda_{\Sigma^0}$ residual
correlation recovers the negative parent $p\Sigma^0$ correlation for $k^* > 70$
Mev/$c$. The neglect of this negative residual correlation would lead to the
underestimation of the parent $p\Lambda$ correlation effect and to an
overestimation of the source size.


title: Double Point Contact in the k=3 Read-Rezayi State

abstract:
  We compute the dependence of the tunneling current in a double point contact
in the k=3 Read-Rezayi state (which is conjectured to describe an
incompressible quantum hall fluid at filling fraction nu=12/5) on voltage,
separation between the two contacts, and temperature. Using the tunneling
hamiltonian of cond-mat/0607431, we show that the effect of quasiholes in the
bulk region between the two contacts is simply an overall constant multiplying
the interference term. This is the same effect as found for the differential
conductivity in cond-mat/0601242; the difference is that we do an actual edge
theory calculation and compute the full current-voltage curve at weak
tunneling.


title:
Coalition Games with Cooperative Transmission: A Cure for the Curse of
  Boundary Nodes in Selfish Packet-Forwarding Wireless Networks

abstract:
  In wireless packet-forwarding networks with selfish nodes, applications of a
repeated game can induce the nodes to forward each others' packets, so that the
network performance can be improved. However, the nodes on the boundary of such
networks cannot benefit from this strategy, as the other nodes do not depend on
them. This problem is sometimes known as the curse of the boundary nodes. To
overcome this problem, an approach based on coalition games is proposed, in
which the boundary nodes can use cooperative transmission to help the backbone
nodes in the middle of the network. In return, the backbone nodes are willing
to forward the boundary nodes' packets. The stability of the coalitions is
studied using the concept of a core. Then two types of fairness, namely, the
min-max fairness using nucleolus and the average fairness using the Shapley
function are investigated. Finally, a protocol is designed using both repeated
games and coalition games. Simulation results show how boundary nodes and
backbone nodes form coalitions together according to different fairness
criteria. The proposed protocol can improve the network connectivity by about
50%, compared with pure repeated game schemes.


title: Reconstruction for models on random graphs

abstract:
  Consider a collection of random variables attached to the vertices of a
graph. The reconstruction problem requires to estimate one of them given `far
away' observations. Several theoretical results (and simple algorithms) are
available when their joint probability distribution is Markov with respect to a
tree. In this paper we consider the case of sequences of random graphs that
converge locally to trees. In particular, we develop a sufficient condition for
the tree and graph reconstruction problem to coincide. We apply such condition
to colorings of random graphs.
  Further, we characterize the behavior of Ising models on such graphs, both
with attractive and random interactions (respectively, `ferromagnetic' and
`spin glass').


title: AGN Variability Surveys: DASCH from BATSS to EXIST

abstract:
  Active galactic nuclei (AGN) are variable on a wide range of timescales,
though relatively few systematic variability surveys have been conducted.
Previous broad-band (both spectral and temporal) variability surveys of AGN are
limited in their temporal and spectral bandwidth, despite their promise for
probing the central engine and black hole mass. We outline optimal properties
for variability studies and provide a brief summary of three new variability
surveys, two (BATSS and DASCH) about to begin and the third (EXIST) possible
within the next decade, which will open new windows on the physics and
fundamental properties of AGN.


title: Cargese lectures on string theory with eight supercharges

abstract:
  These lectures give an introduction to the interrelated topics of Calabi-Yau
compactification of the type II string, black hole attractors, the all-orders
entropy formula, the dual (0,4) CFT, topological strings and the OSV
conjecture. Based on notes by MG of lectures by AS at the 2006 Cargese summer
school.


title: Formation of C- by radiative association

abstract:
  In the present paper the problem of the radiative association of atoms of
carbon C with electrons $e^{-}$ for kinetic temperatures $T_{c}$ of $100 <
T_{c} < 3000$ K is considered. The calculation of the rate rate constant of the
radiative associations is made with principle of detailed balance. It is shown
that the rate has correct behavior (it increase with the temperature) and its
behavior is look-like that for the $H^{-}$ formation rate coefficient, which
also increase with the temperature.


title: Breaking a quantum key distribution system through a timing side channel

abstract:
  The security of quantum key distribution relies on the validity of quantum
mechanics as a description of nature and on the non-existence of leaky degrees
of freedom in the practical implementations. We experimentally demonstrate how,
in some implementations, timing information revealed during public discussion
between the communicating parties can be used by an eavesdropper to
undetectably access a significant portion of the ``secret'' key.


title: A Perverse Sheaf Approach Toward a Cohomology Theory for String Theory

abstract:
  We present the construction and properties of a self-dual perverse sheaf S_0
whose cohomology fulfills some of the requirements of String theory as outlined
by T. Hubsch in hep-th/9612075. The construction of this S_0 utilizes
techniques that follow from MacPherson-Vilonen (Inv. Math. vol. 84, pp.
403-435, 1986). Finally, we will discuss its properties as they relate to
String theory.


title:
D_{s0}^+(2317) as an Iso-triplet Four-quark Meson and Production of Its
  Neutral and Doubly Charged Partners

abstract:
  By studying the decays D_{s0}^+(2317) --> D_s^+ pi^0 and D_s^{*+} gamma, It
is shown that its assignment to the I_3=0 component of iso-triplet scalar
four-quark mesons is favored. Productions of its neutral and doubly charged
partners are also studied. As the result, it is concluded that they could be
observed in B decays. Their iso-singlet partner might have been observed in the
radiative channels of B decays by the BELLE Collaboration.


title: The effect of dissipation on quantum transmission resonance

abstract:
  Quantum transmissions of a free particle passing through a rectangular
potential barrier with dissipation are studied using a path decomposition
technique. Dissipative processes strongly suppress the transmission probability
at resonance just above the barrier resulting in an unexpected reduction of the
mean traversal time through the potential barrier.


title: Looking beyond the horizon

abstract:
  In this short talk we review our results from the paper hep-th/0604075 with
the main stress on the issues of causality and acoustic metric in eikonal
approximation. In addition we correct the formula for the redshift of sound
signals from our original work. We show that, if there exists a special kind of
Born-Infeld type scalar field, then one can send information from inside a
black hole. This information is encoded in perturbations of the field
propagating in non-trivial scalar field backgrounds, which serve as a "new
ether". Although the action of the theory is manifestly Lorentz-invariant the
non-trivial solutions break this symmetry spontaneously, allowing, the
superluminal propagation of perturbations with respect to this "new ether". We
found the stationary solution for background, which describes the accretion of
the scalar field onto a black hole. Examining the propagation of small
perturbations around this solution we show that the signals emitted inside the
Schwarzschild horizon can reach an observer located outside the black hole.
Thus the accreting field forms a hydrodynamical analog of a black hole whose
horizon is inside of the gravitational black hole drawing in the scalar field.


title: Solitary and shock waves in discrete double power-law materials

abstract:
  A novel strongly nonlinear laminar metamaterial supporting new types of
solitary and shock waves with impact energy mitigating capabilities is
presented. It consists of steel plates with intermittent polymer toroidal rings
acting as strongly nonlinear springs with large allowable strain. Their
force-displacement relationship is described by the addition of two power-law
relationships resulting in a solitary wave speed and width depending on the
amplitude. This double nonlinearity allows splitting of an initial impulse into
two separate strongly nonlinear solitary wave trains. Solitary and shock waves
are observed experimentally and analyzed numerically in an assembly with Teflon
o-rings.


title: ASTROD I Charging Simulation and Disturbances

abstract:
  ASTROD I is planned as a single spacecraft mission. It will use
interferometric and pulse ranging techniques between the spacecraft and ground
stations, to make high precision measurements of the parameters that describe
the solar system, and to test relativistic gravity with improved accuracy. At
the heart of the spacecraft is a test mass, which the spacecraft will follow
using a drag-free control system. The mission critically depends on maintaining
the geodesic motion of the test mass. Charging of the test mass due to cosmic
rays and solar particles will disturb its geodesic motion. We have modelled the
charging process using the GEANT4 toolkit and a simplified, geometrical model
and estimate that the ASTROD I test mass will charge positively, at a rate of
24 +/-7 e+/s, due to cosmic ray protons and alpha particles (3He and 4He) at
solar minimum. We have used the results of this simulation to estimate the
magnitude of disturbances associated with test mass charging, for the
worst-case scenario, taking into account uncertainties in the model and
potential charging contributions from minor cosmic-ray components.


title: On the Marginal Distributions of Stationary AR(1) Sequences

abstract:
  In this note we correct an omission in our paper (Satheesh and Sandhya, 2005)
in defining semi-selfdecomposable laws and also show with examples that the
marginal distributions of a stationary AR(1) process need not even be
infinitely divisible.


title:
Orbital magnetization and its effects in spin-chiral ferromagnetic
  Kagome lattice

abstract:
  Recently, Berry phase in the semiclassical dynamical of Bloch electrons has
been found to make a correction to the phase-space density of states and a
general multi-band formula for finite-temperature orbital magnetization has
been given [Phys. Rev. Lett. \textbf{97}, 026603 (2006)], where the orbital
magnetization $\mathcal{M}$ consists of two parts, i.e., the conventional part
$M_{c}$ and the Berry-phase correction part $M_{\Omega}$. Using this general
formula, we theoretically investigate the orbital magnetization and its effects
on thermoelectric transport and magnetic susceptibility properties of the
two-dimensional \textit{kagom\'{e}} lattice with spin anisotropies included.
The study in this paper is highly interesting by the occurrence of nonzero
Chern number in the lattice. The spin chirality parameter $\phi$ (see text)
results in profound effects on the orbital magnetization properties. It is
found that the two parts in orbital magnetization opposite each other. In
particular, we show that $M_{c}$ and $M_{\Omega}$ yield the paramagnetic and
diamagnetic responses, respectively. It is further shown that the orbital
magnetization displays fully different behavior in the metallic and insulating
regions, which is due to the different roles $M_{c}$ and $M_{\Omega}$ play in
these two regions. The anomalous Nernst conductivity is also calculated, which
displays a peak-valley structure as a function of the electron Fermi energy.


title:
Quantum mechanics on Hilbert manifolds: The principle of functional
  relativity

abstract:
  Quantum mechanics is formulated as a geometric theory on a Hilbert manifold.
Images of charts on the manifold are allowed to belong to arbitrary Hilbert
spaces of functions including spaces of generalized functions. Tensor equations
in this setting, also called functional tensor equations, describe families of
functional equations on various Hilbert spaces of functions. The principle of
functional relativity is introduced which states that quantum theory is indeed
a functional tensor theory, i.e., it can be described by functional tensor
equations. The main equations of quantum theory are shown to be compatible with
the principle of functional relativity. By accepting the principle as a
hypothesis, we then analyze the origin of physical dimensions, provide a
geometric interpretation of Planck's constant, and find a simple interpretation
of the two-slit experiment and the process of measurement.


title:
Pressure induced magnetic ordering in Yb2Pd2Sn with two quantum critical
  points

abstract:
  Pressure induced long range antiferromagnetic order is discovered in Yb2Pd2Sn
by measuring the electrical resistivity under pressure up to 5.0 GPa. Magnetic
ordering is observed above about 1.0 GPa, being the lowest pressure in
Yb-intermetallics showing pressure induced magnetic ordering, Unexpectedly,
ordering disappears above about 4.0 GPa, giving rise to the first observation
of the appearance of two quantum critical points persisting in a broad range of
pressure within a single material.


title: Instantons, Hypermultiplets and the Heterotic String

abstract:
  Hypermultiplet couplings in type IIA string theory on a Calabi-Yau space can
be quantum corrected by D2-brane instantons wrapping special Lagrangian cycles.
On the other hand, hypermultiplet couplings in the heterotic string on a K3
surface are corrected by world-sheet instantons wrapping curves. In a class of
examples, we relate these two sets of instanton corrections. We first present
an analogue of the c-map for the heterotic string via a dual flux
compactification of M-theory. Using this duality, we propose two ways of
capturing quantum corrections to hypermultiplets. We then use the orientifold
limit of certain F-theory compactifications to relate curves in K3 to special
Lagrangians in dual type IIA compactifications. We conclude with some results
from perturbative string theory for hypermultiplet F-terms and a conjecture
about the topology of brane instantons.


title:
Singularities of Schr\"oder maps and unhyperbolicity of rational
  functions

abstract:
  We study transcendental singularities of a Schr\"oder map arising from a
rational function $f$, using results from complex dynamics and Nevanlinna
theory. These maps are transcendental meromorphic functions of finite order in
the complex plane. We show that their transcendental singularities lie over the
set where $f$ is not semihyperbolic (unhyperbolic). In addition, if they are
direct, then they lie over only attracting periodic points of $f$, and
moreover, if $f$ is a polynomial, then both direct and indirect singularities
lie over attracting, parabolic and Cremer periodic points of $f$. We also
obtain concrete examples of both kinds of transcendental singularities of
Schr\"oder maps as well as a new proof of the Pommerenke-Levin-Yoccoz
inequality and a new formulation of the Fatou conjecture.


title:
PVLAS experiment, star cooling and BBN constraints: Possible
  interpretation with temperature dependent gauge symmetry breaking

abstract:
  It is known that the kinetic mixing of photon and another U(1)_ex gauge boson
can introduce millicharged particles. Millicharged particles $f$ of mass 0.1 eV
can explain the PVLAS experiment. We suggest a temperature dependent gauge
symmetry breaking of U(1)_ex for this idea to be consistent with astrophysical
and cosmological constraints.


title:
rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma decays in the
  local quark Nambu--Jona-Lasinio model

abstract:
  The branching ratios and photon spectra of the rare processes rho(omega)->
pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework
of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of
diagrams are considered: the quark box and the pole diagrams with scalar
(sigma,a_0(980)) and vector (rho,omega) mesons. The obtained estimations for
the widths of the processes rho(omega)-> pi^0 pi^0 gamma are in satisfactory
agreement with existing experimental data. Predictions are made for the widths
of the processes rho(omega) -> eta pi^0 gamma.


title:
Artificial Tongue-Placed Tactile Biofeedback for perceptual
  supplementation: application to human disability and biomedical engineering

abstract:
  The present paper aims at introducing the innovative technologies, based on
the concept of "sensory substitution" or "perceptual supplementation", we are
developing in the fields of human disability and biomedical engineering.
Precisely, our goal is to design, develop and validate practical assistive
biomedical and/technical devices and/or rehabilitating procedures for persons
with disabilities, using artificial tongue-placed tactile biofeedback systems.
Proposed applications are dealing with: (1) pressure sores prevention in case
of spinal cord injuries (persons with paraplegia, or tetraplegia); (2) ankle
proprioceptive acuity improvement for driving assistance in older and/or
disabled adults; and (3) balance control improvement to prevent fall in older
and/or disabled adults. This paper presents results of three feasibility
studies performed on young healthy adults.


title:
Straggler Identification in Round-Trip Data Streams via Newton's
  Identities and Invertible Bloom Filters

abstract:
  We introduce the straggler identification problem, in which an algorithm must
determine the identities of the remaining members of a set after it has had a
large number of insertion and deletion operations performed on it, and now has
relatively few remaining members. The goal is to do this in o(n) space, where n
is the total number of identities. The straggler identification problem has
applications, for example, in determining the set of unacknowledged packets in
a high-bandwidth multicast data stream. We provide a deterministic solution to
the straggler identification problem that uses only O(d log n) bits and is
based on a novel application of Newton's identities for symmetric polynomials.
This solution can identify any subset of d stragglers from a set of n O(log
n)-bit identifiers, assuming that there are no false deletions of identities
not already in the set. Indeed, we give a lower bound argument that shows that
any small-space deterministic solution to the straggler identification problem
cannot be guaranteed to handle false deletions. Nevertheless, we show that
there is a simple randomized solution using O(d log n log(1/epsilon)) bits that
can maintain a multiset and solve the straggler identification problem,
tolerating false deletions, where epsilon>0 is a user-defined parameter
bounding the probability of an incorrect response. This randomized solution is
based on a new type of Bloom filter, which we call the invertible Bloom filter.


title: Geometric structure of sumsets

abstract:
  Given a finite set of lattice points, we compare its sumsets and lattice
points in its dilated convex hulls. Both of these are known to grow as
polynomials. Generally, the former are subsets of the latter. In this paper, we
will see that sumsets occupy all the central lattice points in convex hulls,
giving us a kind of approximation to lattice points in polytopes.


title:
Absolute Proper Motions of H2O Masers Away from the Galactic Plane
  Measured with VERA in the "Superbubble" Region NGC 281

abstract:
  We report on absolute proper-motion measurements of an H2O maser source in
the NGC 281 West molecular cloud, which is located ~320 pc above the Galactic
plane and is associated with an HI loop extending from the Galactic plane. We
have conducted multi-epoch phase-referencing observations of the maser source
with VERA (VLBI Exploration of Radio Astrometry) over a monitoring period of 6
months since May 2006. We find that the H2O maser features in NGC 281 West are
systematically moving toward the southwest and further away from the Galactic
plane with a vertical velocity of ~20-30 km/s at its estimated distance of
2.2-3.5 kpc. Our new results provide the most direct evidence that the gas in
the NGC 281 region on the HI loop was blown out from the Galactic plane, most
likely in a superbubble driven by multiple or sequential supernova explosions
in the Galactic plane.


title: Vocabulary growth in collaborative tagging systems

abstract:
  We analyze a large-scale snapshot of del.icio.us and investigate how the
number of different tags in the system grows as a function of a suitably
defined notion of time. We study the temporal evolution of the global
vocabulary size, i.e. the number of distinct tags in the entire system, as well
as the evolution of local vocabularies, that is the growth of the number of
distinct tags used in the context of a given resource or user. In both cases,
we find power-law behaviors with exponents smaller than one. Surprisingly, the
observed growth behaviors are remarkably regular throughout the entire history
of the system and across very different resources being bookmarked. Similar
sub-linear laws of growth have been observed in written text, and this
qualitative universality calls for an explanation and points in the direction
of non-trivial cognitive processes in the complex interaction patterns
characterizing collaborative tagging.

categories: cs.IR cond-mat.stat-mech cs.CY physics.data-an


title: Reaction rate calculation by parallel path swapping

abstract:
  The efficiency of path sampling simulations can be improved considerably
using the approach of path swapping. For this purpose, we have devised a new
algorithmic procedure based on the transition interface sampling technique. In
the same spirit of parallel tempering, paths between different ensembles are
swapped, but the role of temperature is here played by the interface position.
We have tested the method on the denaturation transition of DNA using the
Peyrard-Bishop-Dauxois model. We find that the new algorithm gives a reduction
of the computational cost by a factor 20.


title: A fluctuation theorem for currents and non-linear response coefficients

abstract:
  We use a recently proved fluctuation theorem for the currents to develop the
response theory of nonequilibrium phenomena. In this framework, expressions for
the response coefficients of the currents at arbitrary orders in the
thermodynamic forces or affinities are obtained in terms of the fluctuations of
the cumulative currents and remarkable relations are obtained which are the
consequences of microreversibility beyond Onsager reciprocity relations.


title:
Experimental study of the coherent A1 phonons in Te with tailored
  femtosecond pulses

abstract:
  We tailor the shape and phase of the pump pulse spectrum in order to study
the coherent lattice dynamics in tellurium. Employing the coherent control via
splitting the pump pulse into a two-pulse sequence, we show that the
oscillations due to A1 coherent phonons can be cancelled but not enhanced as
compared to single pulse excitation. We further demonstrate that a decisive
factor for the coherent phonon generation is the bandwidth of the pulse
spectrum and not the steepness of the pulse envelope. We also observe that the
coherent amplitude for long pump pulses decreases exponentially independent of
the shape of the pulse spectrum. Finally, by varying the pulse chirp, we show
that the coherent amplitude is independent of while the oscillation lifetime is
dependent on the chirp sign.


title: Towards Antihydrogen Confinement with the ALPHA Antihydrogen Trap

abstract:
  ALPHA is an international project that has recently begun experimentation at
CERN's Antiproton Decelerator (AD) facility. The primary goal of ALPHA is
stable trapping of cold antihydrogen atoms with the ultimate goal of precise
spectroscopic comparisons with hydrogen. We discuss the status of the ALPHA
project and the prospects for antihydrogen trapping.

categories: nucl-ex hep-ex physics.atom-ph physics.plasm-ph


title: A generic mechanism for adaptive growth rate regulation

abstract:
  How can a microorganism adapt to a variety of environmental conditions
despite there exists a limited number of signal transduction machineries? We
show that for any growing cells whose gene expression is under stochastic
fluctuations, adaptive cellular state is inevitably selected by noise, even
without specific signal transduction network for it. In general, changes in
protein concentration in a cell are given by its synthesis minus dilution and
degradation, both of which are proportional to the rate of cell growth. In an
adaptive state with a higher growth speed, both terms are large and balanced.
Under the presence of noise in gene expression, the adaptive state is less
affected by stochasticity since both the synthesis and dilution terms are
large, while for a non-adaptive state both the terms are smaller so that cells
are easily kicked out of the original state by noise. Hence, escape time from a
cellular state and the cellular growth rate are negatively correlated. This
leads to a selection of adaptive states with higher growth rates, and model
simulations confirm this selection to take place in general. The results
suggest a general form of adaptation that has never been brought to light - a
process that requires no specific machineries for sensory adaptation. The
present scheme may help explain a wide range of cellular adaptive responses
including the metabolic flux optimization for maximal cell growth.


title: A Geometrical Approach towards Entanglement

abstract:
  We have studied the concurrence of two-site entanglement and have shown that
it is related to the geometric phase accumulated due to a complete rotation of
the entangled state. The geometric phase and hence the concurrence is evaluated
for transverse Ising model and antiferromagnetic chain which is found to be in
good agreement with that obtained by other methods.


title: Charge and spin stripe in La$_{2-x}$Sr$_{x}$NiO$_{4}$ (x=1/3,1/2)

abstract:
  Electronic structure of stripe ordered La$_{2-x}$Sr$_{x}$NiO$_{4}$ is
investigated. The system with x=1/3 is insulator, in LSDA+U calculations, and
shows charge and spin stripe, consistent with the experimental results. Highly
correlated system of x=1/2 is studied by using exact diagonalization of
multi-orbital many body Hamiltonian derived from LDA calculations and including
on-site and inter-site Coulomb interactions. The fluctuation of the residual
spin on Ni$^{3+}$ (hole) site couples with the charge fluctuation between
Ni$^{3+}$ and Ni$^{2+}$ states and this correlation lowers the total energy.
The resultant ground state is insulator with charge and spin stripe of the
energy gap 0.9eV, consistent with observed one. The on-site Coulomb interaction
stabilizes integral valency of each Ni ion (Ni$^{3+}$ and Ni$^{2+}$), but does
not induce the charge order. Two quantities, inter-site Coulomb interaction and
anisotropy of hopping integrals, play an important role to form the charge and
spin stripe order in a system of x=1/2.


title:
Using force covariance to derive effective stochastic interactions in
  dissipative particle dynamics

abstract:
  There exist methods for determining effective conservative interactions in
coarse grained particle based mesoscopic simulations. The resulting models can
be used to capture thermal equilibrium behavior, but in the model system we
study do not correctly represent transport properties. In this article we
suggest the use of force covariance to determine the full functional form of
dissipative and stochastic interactions. We show that a combination of the
radial distribution function and a force covariance function can be used to
determine all interactions in dissipative particle dynamics. Furthermore we use
the method to test if the effective interactions in dissipative particle
dynamics (DPD) can be adjusted to produce a force covariance consistent with a
projection of a microscopic Lennard-Jones simulation. The results indicate that
the DPD ansatz may not be consistent with the underlying microscopic dynamics.
We discuss how this result relates to theoretical studies reported in the
literature.


title:
Thermodynamically stable noncomposite vortices in mesoscopic two-gap
  superconductors

abstract:
  In mesoscopic two-gap superconductors with sizes of the order of the
coherence length noncomposite vortices are found to be thermodynamically stable
in a large domain of the $T - H$ phase diagram. In these phases the vortex
cores of one condensate are spatially separated from the other condensate ones,
and their respective distributions can adopt distinct symmetries. The
appearance of these vortex phases is caused by a non-negligible effect of the
boundary of the sample on the superconducting order parameter and represents
therefore a genuine mesoscopic effect. For low values of interband Josephson
coupling vortex patterns with $L_1 \neq L_2$ can arise in addition to the
phases with $L_1 =L_2$, where $L_1$ and $L_2$ are total vorticities in the two
condensates. The calculations show that noncomposite vortices could be observed
in thin mesoscopic samples of MgB$_{2}$.


title:
Irreducible three-loop contributions to the pressure in Yang-Mills
  thermodynamics

abstract:
  In the effective theory for the deconfining phase of SU(2) Yang-Mills
thermodynamics we compute estimates for the moduli of the irreducible
three-loop diagrams contributing to the pressure. Our numerical results are in
agreement with general expectations.


title: Jet schemes, arc spaces and the Nash problem

abstract:
  This paper is an introduction to the jet schemes and the arc space of an
algebraic variety. We also introduce the Nash problem on arc families.


title:
A Subaru/Suprime-Cam Survey of M31's spheroid along the South-East minor
  axis

abstract:
  We have used Suprime-Cam on the Subaru Telescope to conduct a V- and I-band
imaging survey of fields sampling the spheroid of the Andromeda galaxy along
its south-east minor axis. Our photometric data are deep enough to resolve
stars down to the red clump. Based on a large and reliable sample of red giant
stars available from this deep wide-field imager, we have derived metallicity
distributions vs. radius and a surface brightness profile over projected
distances of R=23-66 kpc from the galaxy's center. The metallicity
distributions across this region shows a clear high mean metallicity and a
broad distribution ([Fe/H] ~ -0.6 +/- 0.5), and indicates no metallicity
gradient within our observed range. The surface brightness profile at R>40 kpc
is found to be flatter than previously thought. It is conceivable that this
part of the halo samples as yet unidentified, metal-rich substructure.


title:
Correlations between epsilon'/epsilon and Rare K Decays in the Littlest
  Higgs Model with T-Parity

abstract:
  We calculate the CP-violating ratio epsilon'/epsilon in the Littlest Higgs
model with T-parity (LHT) and investigate its correlations with the branching
ratios for K_L -> pi^0 nu {bar nu}, K_L -> pi^0 l^+ l^- and K^+ -> pi^+ nu {bar
nu}. The resulting correlations are rather strong in the case of K_L decays,
but less pronounced in the case of K^+ -> pi^+ nu {bar nu}. Unfortunately, they
are subject to large hadronic uncertainties present in epsilon'/epsilon, whose
theoretical prediction in the Standard Model (SM) is reviewed and updated here.
With the matrix elements of Q_6 (gluon penguin) and Q_8 (electroweak penguin)
evaluated in the large-N limit and m_s^MS(2 GeV) = 100 MeV from lattice QCD,
(epsilon'/epsilon)_SM turns out to be close to the data so that significant
departures of Br(K_L -> pi^0 nu {bar nu}) and Br(K_L -> pi^0 l^+ l^-) from the
SM expectations are unlikely, while Br(K^+ -> pi^+ nu {bar nu}) can be enhanced
even by a factor 5. On the other hand, modest departures of the relevant
hadronic matrix elements from their large-N values allow for a consistent
description of epsilon'/epsilon within the LHT model accompanied by large
enhancements of Br(K_L -> pi^0 nu {bar nu}) and Br(K_L -> pi^0 l^+ l^-), but
only modest enhancements of Br(K^+ -> pi^+ nu {bar nu}).


title: Interacting Energy Components and Observational $H(z)$ Data

abstract:
  In this note, we extend our previous work [Phys. Lett. B 644, 7 (2007),
astro-ph/0609597], and compare eleven interacting dark energy models with
different couplings to the observational $H(z)$ data. However, none of these
models is better than the simplest $\Lambda$CDM model. This implies that either
more exotic couplings are needed in the cosmological models with interaction
between dark energy and dust matter, or {\em there is no interaction at all}.
We consider that this result is disadvantageous to the interacting dark energy
models studied extensively in the literature.


title:
Light nuclei in galactic globular clusters : constraints on the
  self-enrichment scenario from nucleosynthesis

abstract:
  Hydrogen-burning is the root cause of the star-to-star abundance variations
of light nuclei in Galactic globular clusters (GC). In the present work we
constrain the physical conditions that gave rise to the observed abundance
patterns of Li, C, N, O, Na, Mg, Al, as well as Mg isotopes in the typical case
of NGC6752. We perform nucleosynthesis calculations at constant temperature,
adopting realistic initial abundances for the proto-cluster gas. We use a
detailed nuclear reaction network and state-of-the-art nuclear reaction rates.
Although simplistic, our analysis provides original results and new constraints
on the self-enrichment scenario for GCs. Our parametrized calculations allow us
to determine a narrow range of temperature where the observed extreme
abundances of all light elements and isotopes in NGC6752 are nicely reproduced
simultaneously. This agreement is obtained after mixing of the H-processed
material with 30 % of unprocessed gas. The observed C-N, O-Na, Mg-Al, Li-Na and
F-Na anticorrelations, as well as the behaviour of the Mg isotopes can be
recovered by assuming mixing with even larger dilution factors. Li production
by the stars that build up the other abundance anomalies is not mandatory in
the case of NGC 6752. Observations of O, Na, Mg and Al constrain the
temperature range for H-burning; such temperatures are encountered in the two
main candidate ``polluters'' proposed for GCs, namely massive AGBs and the most
massive main-sequence stars. (Abridged).


title:
Groups of diffeomorphisms and geometric loops of manifolds over
  ultra-normed fields

abstract:
  The article is devoted to the investigation of groups of diffeomorphisms and
loops of manifolds over ultra-metric fields of zero and positive
characteristics. Different types of topologies are considered on groups of
loops and diffeomorphisms relative to which they are generalized Lie groups or
topological groups. Among such topologies pairwise incomparable are found as
well. Topological perfectness of the diffeomorphism group relative to certain
topologies is studied. There are proved theorems about projective limit
decompositions of these groups and their compactifications for compact
manifolds. Moreover, an existence of one-parameter local subgroups of
diffeomorphism groups is investigated.


title: The Low Frequency Sensitivity to Gravitational Waves for ASTROD

abstract:
  ASTROD is a relativity mission concept encompassing multi-purposes. One of
its main purposes is to detect gravitational waves sensitive to low-frequency
band similar to LISA, but shifted to lower frequencies. In this aspect, ASTROD
would complement LISA in probing the Universe and study strong-field black hole
physics. Since ASTROD will be after LISA, in the Cosmic Vision time-frame
2015-2025, a ten-fold improvement over LISA accelerometer noise goal would be
possible, allowing us to test relativistic gravity to 1 ppb and improve the
gravitational-wave sensitivity. In this paper, we address to this possible
improvement, especially in the frequency range below 0.1 mHz. We look into
possible thermal noise improvement, magnetic noise improvement, spurious
discharging noise improvement and local gravitational noise improvement. We
discuss various possibilities of lower-frequency gravitational-wave responses
and their significance to potential astrophysical sources.