title:
Visual Observation and Quantitative Measurement of the Microwave
  Absorbing Effect at X band

abstract:
  We have setup a simple field mapping measure system to describe graphically
the 2D quasi-free-space electromagnetic wave in a parallel plate waveguide at
the X-band frequencies. Our apparatus illustrates a potential application in
characterizing the microwave absorbing materials. The visual demonstration
about the physical process and quantitative measurement of reflectivity
coefficients can be achieved. This simple apparatus has have an advantage over
with conventional testing methods which usually involve huge, expensive
anechoic chambers and demand samples of large size.


title:
Fourier transform of function on locally compact Abelian groups taking
  value in Banach spaces

abstract:
  We consider Fourier transform of vector-valued functions on a locally compact
group $G$, which take value in a Banach space $X$, and are square-integrable in
Bochner sense. If $G$ is a finite group then Fourier transform is a bounded
operator. If $G$ is an infinite group then Fourier transform $F: L_2(G,X)\to
L_2(\widehat G,X)$ is a bounded operator if and only if Banach space $X$ is
isomorphic to a Hilbert one.


title:
A priori Holder estimate, parabolic Harnack principle and heat kernel
  estimates for diffusions with jumps

abstract:
  In this paper, we consider the following type of non-local
  (pseudo-differential) operators $\LL $ on $\R^d$:
  $$
  \LL u(x) =\frac12 \sum_{i, j=1}^d \frac{\partial}{\partial x_i} (a_{ij}(x)
\frac{\partial}{\partial x_j}) +
  \lim_{\eps \downarrow 0} \int_{\{y\in \R^d: |y-x|>\eps\}}
  (u(y)-u(x)) J(x, y) dy,
  $$ where $A(x)=(a_{ij}(x))_{1\leq i, j\leq d}$ is a measurable $d\times d$
matrix-valued function on $\R^d$ that is uniform elliptic and bounded and $J$
is a symmetric measurable non-trivial non-negative kernel on $\R^d\times \R^d$
satisfying certain conditions. Corresponding to $\LL$ is a symmetric strong
Markov process $X$ on $\R^d$ that has both the diffusion component and pure
jump component. We establish a priori H\"older estimate for bounded parabolic
functions of $\LL$ and parabolic Harnack principle for positive parabolic
functions of $\LL$. Moreover, two-sided sharp heat kernel estimates are derived
for such operator $\LL$ and jump-diffusion $X$. In particular, our results
apply to the mixture of symmetric diffusion of uniformly elliptic divergence
form operator and mixed stable-like processes on $\R^d$. To establish these
results, we employ methods from both probability theory and analysis.


title: The origin of lopsidedness in galaxies

abstract:
  It has long been known that a large fraction of disc galaxies are lopsided.
We simulate three different mechanisms that can induce lopsidedness: flyby
interactions, gas accretion from cosmological filaments and ram pressure from
the intergalactic medium. Comparing the morphologies, HI spectrum and m=1
Fourier components, we find that all of these mechanisms can induce
lopsidedness in the gaseous component of disc galaxies. In particular, we
estimate that flybys can contribute to ~20 per cent of lopsided galaxies. We
compare our simulations with the observations of NGC 891, a lopsided, edge-on
galaxy with a nearby companion (UGC 1807). We find that the main properties of
NGC 891 favour a flyby event for the origin of lopsidedness in this galaxy.


title: Robust hedging of double touch barrier options

abstract:
  We consider model-free pricing of digital options, which pay out if the
underlying asset has crossed both upper and lower barriers. We make only weak
assumptions about the underlying process (typically continuity), but assume
that the initial prices of call options with the same maturity and all strikes
are known. Under such circumstances, we are able to give upper and lower bounds
on the arbitrage-free prices of the relevant options, and further, using
techniques from the theory of Skorokhod embeddings, to show that these bounds
are tight. Additionally, martingale inequalities are derived, which provide the
trading strategies with which we are able to realise any potential arbitrages.
We show that, depending of the risk aversion of the investor, the resulting
hedging strategies can outperform significantly the standard delta/vega-hedging
in presence of market frictions and/or model misspecification.


title:
Anomaly Mediation and Radius Stabilization by a Boundary Constant
  Superpotential in a Warped Space

abstract:
  We present a very simple model of the radius stabilization in a
supersymmetric (SUSY) Randall-Sundrum model with a hypermultiplet and a
boundary constant superpotential. A wide range of parameters where the anomaly
mediation of SUSY breaking is dominated is found although there are many
problematic bulk effects of SUSY breaking. A negative cosmological constant in
the radius stabilized vacuum can be cancelled by a localized SUSY breaking.
Making use of this localized SUSY breaking also solves the \mu-problem by
Giudice-Masiero mechanism.


title: Evolutionary Model of Species Body Mass Diversification

abstract:
  We present a quantitative model for the biological evolution of species body
masses within large groups of related species, e.g., terrestrial mammals, in
which body mass M evolves according to branching (speciation), multiplicative
diffusion, and an extinction probability that increases logarithmically with
mass. We describe this evolution in terms of a convection-diffusion-reaction
equation for ln M. The steady-state behavior is in good agreement with
empirical data on recent terrestrial mammals, and the time-dependent behavior
also agrees with data on extinct mammal species between 95 - 50 Myr ago.


title:
The Visual Orbit of the 1.1-day Spectroscopic Binary \sigma^2 Coronae
  Borealis from Interferometry at the CHARA Array

abstract:
  We present an updated spectroscopic orbit and a new visual orbit for the
double-lined spectroscopic binary \sigma^2 Coronae Borealis based on radial
velocity measurements at the Oak Ridge Observatory in Harvard, Massachusetts
and interferometric visibility measurements at the CHARA Array on Mount Wilson.
\sigma^2 CrB is composed of two Sun-like stars of roughly equal mass in a
circularized orbit with a period of 1.14 days. The long baselines of the CHARA
Array have allowed us to resolve the visual orbit for this pair, the shortest
period binary yet resolved interferometrically, enabling us to determine
component masses of 1.137 \pm 0.037 M_sun and 1.090 \pm 0.036 M_sun. We have
also estimated absolute V-band magnitudes of MV (primary) = 4.35 \pm 0.02 and
MV(secondary) = 4.74 \pm 0.02. A comparison with stellar evolution models
indicates a relatively young age of 1-3 Gyr, consistent with the high Li
abundance measured previously. This pair is the central component of a
quintuple system, along with another similar-mass star, \sigma^1 CrB, in a ~
730-year visual orbit, and a distant M-dwarf binary, \sigma CrB C, at a
projected separation of ~ 10 arcmin. We also present differential proper motion
evidence to show that components C & D (ADS 9979C & D) listed for this system
in the Washington Double Star Catalog are optical alignments that are not
gravitationally bound to the \sigma CrB system.


title:
Coarse-graining stochastic biochemical networks: quasi-stationary
  approximation and fast simulations using a stochastic path integral technique

abstract:
  We propose a universal approach for analysis and fast simulations of stiff
stochastic biochemical kinetics networks, which rests on elimination of fast
chemical species without a loss of information about mesoscopic, non-Poissonian
fluctuations of the slow ones. Our approach, which is similar to the
Born-Oppenheimer approximation in quantum mechanics, follows from the
stochastic path integral representation of the full counting statistics of
reaction events (also known as the cumulant generating function). In
applications with a small number of chemical reactions, this approach produces
analytical expressions for moments of chemical fluxes between slow variables.
This allows for a low-dimensional, interpretable representation of the
biochemical system, that can be used for coarse-grained numerical simulation
schemes with a small computational complexity and yet high accuracy. As an
example, we consider a chain of biochemical reactions, derive its
coarse-grained description, and show that the Gillespie simulations of the
original stiff system, the coarse-grained simulations, and the full analytical
treatment are in an agreement, but the coarse-grained simulations are three
orders of magnitude faster than the Gillespie analogue.

categories: q-bio.MN cond-mat.stat-mech physics.bio-ph q-bio.QM


title:
Reply to "the Comment on `Gauge Invariance and kT-Factorization of
  Exclusive Processes'"

abstract:
  A new method is proposed to calculate wave functions in $k_T$-factorization
in \cite{LiMi} as a comment about our paper \cite{FMW}. We point out that the
results obtained with the method are in conflict with the translation
invariance and depend on the chosen contours for loop-integrals. Therefore, the
method is in principle unacceptable and the results with the method cannot be
correct.


title: Interference of the evolutions of Rb and Na Bose-Einstein condensates

abstract:
  Spin evolution of a mixture of two species of spin-1 Bose-Einstein
condensates (Rb and Na) has been investigated beyond the mean field theory.
Both analytical expression and numerical results on the populations of
spin-components are obtained. The interference is found to depend on the
initial states and the inter-species interaction sensitively. A number of
phenomena arising from the interference have been predicted. In particular,
periodic behavior and the alternate appearances of a zone of oscillation and a
long quiet zone are found.


title:
The H\"older continuity of a class of 3-dimension ultraparabolic
  equations

abstract:
  We obtained the $C^\alpha$ continuity for weak solutions of a class of
ultraparabolic equations with measurable coefficients of the form $${\partial_t
u} = \partial_x(a(x,y,t)\partial_x u) +b_0(x,y,t)\partial_x
u+b(x,y,t)\partial_y u,$$ which generalized our recent results on KFP
equations.


title:
Trace Element Analysis of Potassium by Resonance Ionization Mass
  Spectrometry

abstract:
  A simple resonance ionization mass spectrometer is built with a Quadrupole
Mass Spectrometer (QMS) and two laser diodes aiming at trace analysis of
potassium. The overall detection efficiency is estimated comparing the yields
of resonance ionization and electron-impact ionization in the same QMS. A clear
discrimination of $^{39}\rm K$, $^{40}\rm K$ and $^{41}\rm K$ is demonstrated
with a help of isotope shifts of the atomic levels.


title:
Coherent manipulation of nuclear spins in the breakdown regime of
  integer quantum Hall states

abstract:
  We demonstrate a new method for electrical manipulation of nuclear spins
utilizing dynamic nuclear polarization induced by quantum Hall effect
breakdown. Nuclear spins are polarized and detected through the hyperfine
interaction between a nuclear spin system and a two-dimensional electron system
located at an interface of GaAs/AlGaAs single heterostructure. Coherent
oscillations between the nuclear-spin quantum states are observed by measuring
the longitudinal voltage of the conductor.


title: Fundamental Dominations in Graphs

abstract:
  Nine variations of the concept of domination in a simple graph are identified
as fundamental domination concepts, and a unified approach is introduced for
studying them. For each variation, the minimum cardinality of a subset of
dominating elements is the corresponding fundamental domination number. It is
observed that, for each nontrivial connected graph, at most five of these nine
numbers can be different, and inequalities between these five numbers are
given. Finally, these fundamental dominations are interpreted in terms of the
total graph of the given graph, a concept introduced by the second author in
1965. It is argued that the very first domination concept, defined by O. Ore in
1962 and under a different name by C. Berge in 1958, deserves to be called the
most fundamental of graph dominations.


title: Search for pair production of second generation scalar leptoquarks

abstract:
  We report on a search for the pair production of second generation scalar
leptoquarks (LQ) in ppbar collisions at the center of mass energy sqrt(s)=1.96
TeV using a data set corresponding to an integrated luminosity of 1.0 fb-1
collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies
arising from the LQLQbar->muqnuq and LQLQbar->muqmuq decay modes are
investigated. No excess of data over the standard model prediction is observed
and upper limits on the leptoquark pair production cross section are derived at
the 95% C.L. as a function of the leptoquark mass and the branching fraction
beta for the decay LQ->muq. These are interpreted as lower limits on the
leptoquark mass as a function of beta. For beta=1 (0.5), scalar second
generation leptoquarks with masses up to 316 GeV (270 GeV) are excluded.


title:
The Center of Mass for Spatial Branching Processes and an Application
  for Self-Interaction

abstract:
  In this paper we prove that the center of mass of a supercritical
branching-Brownian motion, or that of a supercritical super-Brownian motion
tends to a limiting position almost surely, which, in a sense complements a
result of Tribe on the final behavior of a critical super-Brownian motion. This
is shown to be true also for a model where branching Brownian motion is
modified by attraction/repulsion between particles.
  We then put this observation together with the description of the interacting
system as viewed from its center of mass, and get the following asymptotic
behavior: the system asymptotically becomes a branching Ornstein Uhlenbeck
process (inward for attraction and outward for repulsion), but the origin is
shifted to a random point which has normal distribution, and the Ornstein
Uhlenbeck particles are not independent but constitute a system with a degree
of freedom which is less by their number by precisely one.


title:
Interplay of frustration, magnetism, charge ordering, and covalency in a
  model of Na0.5CoO2

abstract:
  We investigate an effective Hamiltonian for Na0.5CoO2 that includes the
electrostatic potential due to the ordered Na ions and strong electronic
correlations. This model displays a subtle interplay between metallic and
insulating phases and between charge and magnetic order. For realistic
parameters, the model predicts an insulating phase with similarities to a
covalent insulator. We show that this interpretation gives a consistent
explanation of experiments on Na0.5CoO2, including the small degree of charge
ordering, the small charge gap, the large moment, and the optical conductivity.


title: Flavor structure with multi moduli in 5D SUGRA

abstract:
  We investigate 5-dimensional supergravity on S^1/Z_2 with a physical Z_2-odd
vector multiplet, which yields an additional modulus other than the radion. We
find additional terms in the 4-dimensional effective theory that are peculiar
to the multi moduli case. Such terms can make the soft masses are non-tachyonic
and almost flavor-universal at tree-level, in contrast to the single modulus
case. This provides a new possibility to solve the SUSY flavor problem.


title: Regular projections of graphs with at most three double points

abstract:
  A generic immersion of a planar graph into the 2-space is said to be knotted
if there does not exist a trivial embedding of the graph into the 3-space
obtained by lifting the immersion with respect to the natural projection from
the 3-space to the 2-space. In this paper we show that if a generic immersion
of a planar graph is knotted then the number of double points of the immersion
is more than or equal to three. To prove this, we also show that an embedding
of a graph obtained from a generic immersion of the graph (does not need to be
planar) with at most three double points is totally free if it contains neither
a Hopf link nor a trefoil knot.


title: On a Construction of L. Hua for Positive Reproducing Kernels

abstract:
  We study a positive reproducing kernel for holomorphic functions on a domain
in a complex space. The technique is based on an idea of L. Hua. Applications
are provided. These ideas were developed in another context (quantization of
K\"{a}hler manifolds) by Berezin.


title: Nakajima's remark on Henn's proof

abstract:
  We fill up a gap in Henn's proof concerning large automorphism groups of
function fields of degree 1 over an algebraically closed field of positive
characteristic.


title: The onset of superfluidity in capillary flow of liquid helium 4

abstract:
  The onset mechanism of superfluidity is examined by taking the case of the
capillary flow of liquid helium 4. In the capillary flow, a substantial fall of
the shear viscosity has been observed in the normal phase (lambda
point<T<3.7K). In this temperature region, under the strong influence of Bose
statistics, the coherent many-body wave function grows to an intermediate size
between a macroscopic and a microscopic one, which is different from thermal
fluctuation. We consider such a capillary flow by including it to a general
picture that includes the flow of rotating helium 4 as well. Using the
Kramers-Kronig relation, we express the inverse of the shear viscosity in terms
of the generalized susceptibility of the system, and obtain a formula for the
shear viscosity in the vicinity of the lambda point. Regarding bosons without
the condensate as a non-perturbative state, we make a perturbation calculation
of the susceptibility with respect to the repulsive interaction. With
decreasing temperature from 3.7K, the growth of the coherent wave function
gradually suppresses the shear viscosity, and makes the superfluid flow stable.
Comparing formulas obtained to the experimental data, we estimate that the
ratio of the superfluid density defined in the mechanical sense reaches
1/100000 just above the lambda point.


title: Hybrid data regression modelling in measurement

abstract:
  Measurement involves the determination of quantitative estimates of physical
quantities from experiment, along with estimates of their associated
uncertainties. Herewith an experimental system model is the key to extracting
information from the experimental data. The measurement information obtained
depends directly on the quality of the model. With this concern novel
regression modelling techniques have been fashioned by data integration from
computer-simulation and physical designed experiments. These techniques have
allowed attaining the advanced level of model completeness, parsimony, and
precision via approximation of the exact unknown model by mathematical product
of available theoretical and appropriate empirical functions. The purpose of
this approximation is to represent adequately the true model on the considered
region of factor space with all advantages of theoretical modelling. This
allows a further focus on the measurement science of issue. Pneumatic gauge
hybrid data candidate model building, solving and validation reviled that such
adequate models permit to attain minimum discrepancy from empirical evidence.


title: Karl Pearson's Theoretical Errors and the Advances They Inspired

abstract:
  Karl Pearson played an enormous role in determining the content and
organization of statistical research in his day, through his research, his
teaching, his establishment of laboratories, and his initiation of a vast
publishing program. His technical contributions had initially and continue
today to have a profound impact upon the work of both applied and theoretical
statisticians, partly through their inadequately acknowledged influence upon
Ronald A. Fisher. Particular attention is drawn to two of Pearson's major
errors that nonetheless have left a positive and lasting impression upon the
statistical world.


title:
The anisotropy of two dimensional percolation clusters of self-affine
  models

abstract:
  The anisotropy parameter of two-dimensional equilibrium clusters of site
percolation process in long-range self-affine correlated structures are studied
numerically. We use a fractional Brownian Motion(FBM) statistic to produce both
persistent and anti-persistent long-range correlations in 2-D models. It is
seen that self affinity makes the shape of percolation clusters slightly more
isotropic. Moreover, we find that the sign of correction to scaling term is
determined by the nature of correlation. For persistent correlation the
correction to scaling term adds a negative contribution to the anisotropy of
percolation clusters, while for the anti-persistent case it is positive.


title:
Classical energy momentum tensor renormalisation via effective field
  theory methods

abstract:
  We apply the Effective Field Theory approach to General Relativity,
introduced by Goldberger and Rothstein, to study point-like and string-like
sources in the context of scalar-tensor theories of gravity. Within this
framework we compute the classical energy-momentum tensor renormalization to
first Post-Newtonian order or, in the case of extra scalar fields, up to first
order in the (non-derivative) trilinear interaction terms: this allows to write
down the corrections to the standard (Newtonian) gravitational potential and to
the extra-scalar potential. In the case of one-dimensional extended sources we
give an alternative derivation of the renormalization of the string tension
enabling a re-analysis of the discrepancy between the results obtained by
Dabholkar and Harvey in one paper and by Buonanno and Damour in another,
already discussed in the latter.


title:
Sur l'homologie des groupes orthogonaux et symplectiques \`a
  coefficients tordus

abstract:
  We compute the stable homology of orthogonal and symplectic groups over a
finite field k with coefficients coming from an usual endofunctor F of k-vector
spaces (exterior, symmetric, divided powers...), that is, for all natural
integer i, we compute the colimits of the vector spaces $H_i(O_{n,n}(k) ;
F(k^{2n}))$ and $H_i(Sp_{2n}(k) ; F(k^{2n}))$. In this situation, the
stabilization is a classical result of Charney. We give a formal framework to
connect stable homology of some families of groups and homology of suitable
small categories thanks to a spectral sequence which collapses in several
cases. By our purely algebraic methods (i.e. without stable K-theory) we obtain
again results of Betley for stable homology of linear groups and symmetric
groups. For orthogonal and symplectic groups over a field we prove a
categorical result for vector spaces equipped with quadratic or alternating
forms and use powerful cancellation results known in homology of functors
(Suslin, Scorichenko, Djament) to deduce a spectacular simplification of the
second sheet of our general spectral sequence. When we consider the orthogonal
and symplectic groups over a finite field and we take coefficients with values
in vector spaces over the same field, we can compute the second sheet of the
spectral sequence thanks to classical results: homological cancellation with
trivial coefficients (Quillen, Fiedorowicz-Priddy) and calculation of torsion
groups between usual functors (Franjou-Friedlander-Scorichenko-Suslin,
Chalupnik).


title:
Theory for the phase behaviour of a colloidal fluid with competing
  interactions

abstract:
  We study the phase behaviour of a fluid composed of particles which interact
via a pair potential that is repulsive for large inter-particle distances, is
attractive at intermediate distances and is strongly repulsive at short
distances (the particles have a hard core). As well as exhibiting gas-liquid
phase separation, this system also exhibits phase transitions from the uniform
fluid phases to modulated inhomogeneous fluid phases. Starting from a
microscopic density functional theory, we develop an order parameter theory for
the phase transition in order to examine in detail the phase behaviour. The
amplitude of the density modulations is the order parameter in our theory. The
theory predicts that the phase transition from the uniform to the modulated
fluid phase can be either first order or second order (continuous). The phase
diagram exhibits two tricritical points, joined to one another by the line of
second order transitions.


title:
Coexistence of superconductivity and charge-density waves in a
  two-dimensional Holstein model at half-filling

abstract:
  In one dimension the coupling of electrons to phonons leads to a transition
from a metallic to a Peierls distorted insulated state if the coupling exceeds
a critical value. On the other hand, in two dimensions the electron-phonon
interaction may also lead to the formation of Cooper pairs. This competition of
superconductivity and charge order (in conjunction with a lattice distortion)
is studied in this letter by means of the projector-based renormalization
method (PRM). Increasing the electron-phonon interaction, we find a crossover
behavior between a purely superconducting state and a charge-density wave where
a well-defined parameter range of coexistence of superconductivity and lattice
distortion exists.


title: Closed Magnetic Geodesics on $S^2$

abstract:
  We give existence results for simple closed curves with prescribed geodesic
curvature on $S^{2}$, which correspond to periodic orbits of a charge in a
magnetic field.


title: Anderson transition in a three dimensional kicked rotor

abstract:
  We investigate Anderson localization in a three dimensional (3d) kicked
rotor. By a finite size scaling analysis we have identified a mobility edge for
a certain value of the kicking strength $k = k_c$. For $k > k_c$ dynamical
localization does not occur, all eigenstates are delocalized and the spectral
correlations are well described by Wigner-Dyson statistics. This can be
understood by mapping the kicked rotor problem onto a 3d Anderson model (AM)
where a band of metallic states exists for sufficiently weak disorder. Around
the critical region $k \approx k_c$ we have carried out a detailed study of the
level statistics and quantum diffusion. In agreement with the predictions of
the one parameter scaling theory (OPT) and with previous numerical simulations
of a 3d AM at the transition, the number variance is linear, level repulsion is
still observed and quantum diffusion is anomalous with $<p^2 > \propto
t^{2/3}$. We note that in the 3d kicked rotor the dynamics is not random but
deterministic. In order to estimate the differences between these two
situations we have studied a 3d kicked rotor in which the kinetic term of the
associated evolution matrix is random. A detailed numerical comparison shows
that the differences between the two cases are relatively small. However in the
deterministic case only a small set of irrational periods was used. A
qualitative analysis of a much larger set suggests that the deviations between
the random and the deterministic kicked rotor can be important for certain
choices of periods. Contrary to intuition correlations in the deterministic
case can either suppress or enhance Anderson localization effects.


title: The hidden HI-massive LIRG HIZOA J0836-43: Inside-out galaxy formation

abstract:
  HIZOA J0836-43 is an extreme gas-rich ($M_{\rm{HI}}$=7.5$\times10^{10}
M_{\sun}$) disk galaxy which lies hidden behind the strongly obscuring Vela
region of the Milky Way. Utilizing observations from the {\it Spitzer Space
Telescope}, we have found it to be a luminous infrared starburst galaxy with a
star formation rate of $\sim 21 M_{\sun} \rm{yr^{-1}}$, arising from
exceptionally strong molecular PAH emission ($L_{7.7\micron} = 1.50 \times
10^{9} L_{\odot}$) and far-infrared emission from cold dust. The galaxy
exhibits a weak mid-infrared continuum compared to other starforming galaxies
and U/LIRGs. This relative lack of emission from small grains suggests atypical
interstellar medium conditions compared to other starbursts. We do not detect
significant $[$Ne {\sc v}$]$ or $[$O {\sc iv}$]$, which implies an absent or
very weak AGN. The galaxy possesses a prominent bulge of evolved stars and a
stellar mass of 4.4($\pm$1.4)$\times10^{10} M_{\sun}$. With its plentiful gas
supply and current star formation rate, a doubling of stellar mass would occur
on a timescale of $\sim$2 Gyr. Compared to local galaxies, HIZOA J0836-43
appears to be a "scaled-up" spiral undergoing inside-out formation, possibly
resembling stellar disk building processes at intermediate redshifts.


title: Homotopy, monopoles and 't Hooft tensor for generic gauuge groups

abstract:
  We study monopoles and corresponding 't Hooft tensor in a generic gauge
theory. This issue is relevant to the understanding of the color confinement in
terms of dual symmetry.


title:
Statistical models, likelihood, penalized likelihood and hierarchical
  likelihood

abstract:
  We give an overview of statistical models and likelihood, together with two
of its variants: penalized and hierarchical likelihood. The Kullback-Leibler
divergence is referred to repeatedly, for defining the misspecification risk of
a model, for grounding the likelihood and the likelihood crossvalidation which
can be used for choosing weights in penalized likelihood. Families of penalized
likelihood and sieves estimators are shown to be equivalent. The similarity of
these likelihood with a posteriori distributions in a Bayesian approach is
considered.


title: A Conversation with Jayaram Sethuraman

abstract:
  Jayaram Sethuraman was born in the town of Hubli in Bombay Province (now
Karnataka State) on October 3, 1937. His early years were spent in Hubli and in
1950 his family moved to Madras (now renamed Chennai). He graduated from Madras
University in 1957 with a B.Sc. (Hons) degree in statistics and he earned his
M.A. degree in statistics from Madras University in 1958. He earned a Ph.D. in
statistics from the Indian Statistical Institute in 1962. Before returning to
ISI in 1965 as an Associate Professor, he was a Research Associate at the
University of North Carolina 1962--1963, at Michigan State University in
1963--1964 and at Stanford University 1964--1965. After three years at the ISI,
Sethuraman moved to Florida State University in 1968 as Full Professor. During
his career at FSU, he made sojourns as Visiting Professor to the University of
Michigan, 1974--1975, the ISI in fall 1977, as a Visiting Professor and Acting
Head, ISI Bangalore Center, 1979--1980. He was a senior ASA/NSF/NIST Fellow
1994--1995 and a Fulbright Senior Researcher at ISI Bangalore 1995--1996.
Although Sethuraman officially retired on January 31, 2004 and was named
Professor Emeritus at FSU, he continues to be extremely active. He participates
in all activities in the Department of Statistics and holds a Courtesy
Professor appointment in the Department of Religion. He held an appointment as
Professor, University of Pittsburgh in the fall of 2004, and was a Fulbright
Senior Lecturer at the Indian Statistical Institute of Technology, Chennai,
2005.


title:
Probing the low-luminosity GRB population with new generation satellite
  detectors

abstract:
  We compare the detection rates and redshift distributions of low-luminosity
(LL) GRBs localized by Swift with those expected to be observed by the new
generation satellite detectors on GLAST (now Fermi) and, in future, EXIST.
Although the GLAST burst telescope will be less sensitive than Swift's in the
15--150 keV band, its large field-of-view implies that it will double Swift's
detection rate of LL bursts. We show that Swift, GLAST and EXIST should detect
about 1, 2 & 30 LL GRBs, respectively, over a 5-year operational period. The
burst telescope on EXIST should detect LL GRBs at a rate of more than an order
of magnitude greater than that of Swift's BAT. We show that the detection
horizon for LL GRBs will be extended from $z \simeq 0.4$ for Swift to $z \simeq
1.1$ in the EXIST era. Also, the contribution of LL bursts to the observed GRB
redshift distribution will contribute to an identifiable feature in the
distribution at $z \simeq 1$.


title: Role of Three-Qubit Mixed-States Entanglement in Teleportation Scheme

abstract:
  The bipartite quantum teleportation with a three-qubit mixture of GHZ and W
states as a quantum channel is discussed. When the quantum channel is a mixed
state consisting of the GHZ state plus small perturbed W state, the
entanglement of the channel becomes zero when the average fidelity
$\bar{F}_{GHZ}$ is less than 0.775. This means that the mixed state cannot play
an any role as a quantum channel at $\bar{F}_{GHZ} \leq 0.775$. For the case of
the mixed state consisting of the W state plus small perturbed GHZ state it
turn out that this mixed state cannot play a role as a quantum channel at
$\bar{F}_W \leq 0.833$.


title:
Inverse Monte-Carlo and Demon Methods for Effective Polyakov Loop Models
  of SU(N)-YM

abstract:
  We study effective Polyakov loop models for SU(N) Yang-Mills theories at
finite temperature. In particular effective models for SU(3) YM with an
additional adjoint Polyakov loop potential are considered. The rich phase
structure including a center and anti-center directed phase is reproduced with
an effective model utilizing the inverse Monte-Carlo method. The demon method
as a possibility to obtain the effective models' couplings is compared to the
method of Schwinger-Dyson equations. Thermalization effects of microcanonical
and canonical demon method are analyzed. Finally the elaborate canonical demon
method is applied to the finite temperature SU(4) YM phase transition.


title:
Early Abnormal Temperature Structure of X-ray Looptop Source of Solar
  Flares

abstract:
  This Letter is to investigate the physics of a newly discovered phenomenon --
contracting flare loops in the early phase of solar flares. In classical flare
models, which were constructed based on the phenomenon of expansion of flare
loops, an energy releasing site is put above flare loops. These models can
predict that there is a vertical temperature gradient in the top of flare loops
due to heat conduction and cooling effects. Therefore, the centroid of an X-ray
looptop source at higher energy bands will be higher in altitude, for which we
can define as normal temperature distribution. With observations made by {\it
RHESSI}, we analyzed 10 M- or X-class flares (9 limb flares). For all these
flares, the movement of looptop sources shows an obvious U-shaped trajectory,
which we take as the signature of contraction-to-expansion of flare loops. We
find that, for all these flares, normal temperature distribution does exist,
but only along the path of expansion. The temperature distribution along the
path of contraction is abnormal, showing no spatial order at all. The result
suggests that magnetic reconnection processes in the contraction and expansion
phases of these solar flares are different.


title:
Two-dimensional fluid with competing interactions exhibiting microphase
  separation: theory for bulk and interfacial properties

abstract:
  Colloidal particles that are confined to an interface such as the air-water
interface are an example of a two-dimensional fluid. Such dispersions have been
observed to spontaneously form cluster and stripe morphologies in certain
systems with isotropic pair potentials between the particles, due to the fact
that the pair interaction between the colloids has competing attraction and
repulsion over different length scales. Here we present a simple density
functional theory for a model of such a two-dimensional fluid. The theory
predicts a bulk phase diagram exhibiting cluster, stripe and bubble modulated
phases, in addition to homogeneous fluid phases. Comparing with simulation
results for this model from the literature, we find that the theory is
qualitatively reliable. The model allows for a detailed investigation of the
structure of the fluid and we are able to obtain simple approximate expressions
for the static structure factor and for the length scale characterising the
modulations in the microphase separated phases. We also investigate the
behaviour of the system under confinement between two parallel hard walls. We
find that the confined fluid phase behaviour can be rather complex.


title: The Unitary Implementation of a Measured Quantum Groupoid action

abstract:
  Mimicking the von Neumann version of Kustermans and Vaes' locally compact
quantum groups, Franck Lesieur had introduced a notion of measured quantum
groupoid, in the setting of von Neumann algebras. In a former article, the
author had introduced the notion of actions, crossed-product, dual actions of a
measured quantum groupoid: a biduality theorem for actions had been proved.
This article continues that program : we prove the existence of a standard
implementation for an action, and a bidulaity theorem for weights. We
generalize this way results which were proved, for locally compact quantum
groups by S. Vaes, and for measured groupoids by T. Yamanouchi.


title: Optimizing the double description method for normal surface enumeration

abstract:
  Many key algorithms in 3-manifold topology involve the enumeration of normal
surfaces, which is based upon the double description method for finding the
vertices of a convex polytope. Typically we are only interested in a small
subset of these vertices, thus opening the way for substantial optimization.
Here we give an account of the vertex enumeration problem as it applies to
normal surfaces, and present new optimizations that yield strong improvements
in both running time and memory consumption. The resulting algorithms are
tested using the freely available software package Regina.


title:
Honest variable selection in linear and logistic regression models via
  $\ell_1$ and $\ell_1+\ell_2$ penalization

abstract:
  This paper investigates correct variable selection in finite samples via
$\ell_1$ and $\ell_1+\ell_2$ type penalization schemes. The asymptotic
consistency of variable selection immediately follows from this analysis. We
focus on logistic and linear regression models. The following questions are
central to our paper: given a level of confidence $1-\delta$, under which
assumptions on the design matrix, for which strength of the signal and for what
values of the tuning parameters can we identify the true model at the given
level of confidence? Formally, if $\widehat{I}$ is an estimate of the true
variable set $I^*$, we study conditions under which
$\mathbb{P}(\widehat{I}=I^*)\geq 1-\delta$, for a given sample size $n$, number
of parameters $M$ and confidence $1-\delta$. We show that in identifiable
models, both methods can recover coefficients of size $\frac{1}{\sqrt{n}}$, up
to small multiplicative constants and logarithmic factors in $M$ and
$\frac{1}{\delta}$. The advantage of the $\ell_1+\ell_2$ penalization over the
$\ell_1$ is minor for the variable selection problem, for the models we
consider here. Whereas the former estimates are unique, and become more stable
for highly correlated data matrices as one increases the tuning parameter of
the $\ell_2$ part, too large an increase in this parameter value may preclude
variable selection.


title: Measured quantum groupoids with a central basis

abstract:
  Mimicking the von Neumann version of Kustermans and Vaes' locally compact
quantum groups, Franck Lesieur had introduced a notion of measured quantum
groupoid, in the setting of von Neumann algebras. In this article, we suppose
that the basis of the measured quantum groupoid is central; in that case, we
prove that a specific sub-${\bf C}^*$ algebra is invariant under all the data
of the measured quantum groupoid; moreover, this sub-${\bf C}^*$-algebra is a
continuous field of ${\bf C}^*$-algebras; when the basis is central in both the
measured quantum groupoid and its dual, we get that the measured quantum
groupoid is a continuous field of locally compact quantum groups. On the other
hand, using this sub-${\bf C}^*$-algebra, we prove that any abelian measured
quantum groupoid comes from a locally compact groupoid.


title:
AGILE detection of variable gamma-ray activity from the blazar S5
  0716+714 in September-October 2007

abstract:
  We report the gamma-ray activity from the intermediate BL Lac S5 0716+714
during observations acquired by the AGILE satellite in September and October
2007. These detections of activity were contemporaneous with a period of
intense optical activity, which was monitored by GASP-WEBT. This simultaneous
optical and gamma-ray coverage allows us to study in detail the light curves,
time lags, gamma-ray photon spectrum, and Spectral Energy Distributions (SEDs)
during different states of activity. AGILE observed the source with its two
co-aligned imagers, the Gamma-Ray Imaging Detector (GRID) and the hard X-ray
imager (Super-AGILE), which are sensitive to the 30 MeV-50 GeV and 18-60 keV
energy ranges, respectively. Observations were completed in two different
periods, the first between 2007 September 4-23, and the second between 2007
October 24-November 1. Over the period 2007 September 7-12, AGILE detected
gamma-ray emission from the source at a significance level of 9.6-sigma with an
average flux (E>100 MeV) of (97 +/- 15) x 10^{-8} photons cm^{-2} s^{-1}, which
increased by a factor of at least four within three days. No emission was
detected by Super-AGILE for the energy range 18-60 keV to a 3-sigma upper limit
of 10 mCrab in 335 ksec. In October 2007, AGILE repointed toward S5 0716+714
following an intense optical flare, measuring an average flux of (47 +/- 11) x
10^{-8} photons cm^{-2} s^{-1} at a significance level of 6.0-sigma. The
gamma-ray flux of S5 0716+714 detected by AGILE is the highest ever detected
for this blazar and one of the most intense gamma-ray fluxes detected from a BL
Lac object. The SED of mid-September appears to be consistent with the
synchrotron self-Compton (SSC) emission model, but only by including two SSC
components of different variabilities.


title: Dynamic Response of Block Copolymer Wormlike Micelles to Shear Flow

abstract:
  The linear and non-linear dynamic response to an oscillatory shear flow of
giant wormlike micelles consisting of Pb-Peo block copolymers is studied by
means of Fourier transform rheology. Experiments are performed in the vicinity
of the isotropic-nematic phase transition concentration, where the location of
isotropic-nematic phase transition lines is determined independently. Strong
shear-thinning behaviour is observed due to critical slowing down of
orientational diffusion as a result of the vicinity of the isotropic- nematic
spinodal. This severe shear-thinning behaviour is shown to result in gradient
shear banding. Time-resolved Small angle neutron scattering experiments are
used to obtain insight in the microscopic phenomena that underly the observed
rheological response. An equation of motion for the order-parameter tensor and
an expression of the stress tensor in terms of the order-parameter tensor are
used to interpret the experimental data, both in the linear and non-linear
regime. Scaling of the dynamic behaviour of the orientational order parameter
and the stress is found when critical slowing down due to the vicinity of the
isotropic-nematic spinodal is accounted for.


title:
Age determination of possible binary open clusters NGC 2383/NGC 2384 and
  Pismis 6/Pismis 8

abstract:
  Based on 2MASS J and Ks photometry for the open star clusters NGC 2383, NGC
2384,Pismis 6, Pismis 8 and using color magnitude diagrams with isochrones fit,
we found an age of $\log ({age})$ = 8.3 (200 $\pm$ 6 Myr) for NGC 2383 and
$\log ({age})$ = 6.9 (8 $\pm$ 6 Myr) for NGC 2384. For Pismis 6 and Pismis 8 we
adopted a range of $\log ({age})$ = 6 - 7 (1 - 10 Myr). Because they similar
ages, Pismis 6 and Pismis 8 may have been formed in the same Giant Molecular
Cloud, and we concluded they are a good candidate for a binary system. In the
case of NGC 2383 and NGC 2384, because the big age difference found we conclude
that most probably they are born in different environments and as well are not
physically connected.


title: Black hole entropy for the general area spectrum

abstract:
  We consider the possibility that the horizon area is expressed by the general
area spectrum in loop quantum gravity and calculate the black hole entropy by
counting the degrees of freedom in spin-network states related to its area.
Although the general area spectrum has a complex expression, we succeeded in
obtaining the result that the black hole entropy is proportional to its area as
in previous works where the simplified area formula has been used. This gives
new values for the Barbero-Immirzi parameter ($\gamma =0.5802... \mathrm{or}
0.7847...$) which are larger than that of previous works.


title: Sparse sampling: Spatial design for monitoring stream networks

abstract:
  Spatial designs for monitoring stream networks, especially ephemeral systems,
are typically non-standard, `sparse' and can be very complex, reflecting the
complexity of the ecosystem being monitored, the scale of the population, and
the competing multiple monitoring objectives. The main purpose of this paper is
to present a review of approaches to spatial design to enable informed
decisions to be made about developing practical and optimal spatial designs for
future monitoring of streams.


title: Fonctions L d'Artin et nombre de Tamagawa motiviques

abstract:
  In the first part of this text, we define motivic Artin L-fonctions via a
motivic Euler product, and show that they coincide with the analogous functions
introduced by Dhillon and Minac. In the second part, we define under some
assumptions a motivic Tamagawa number and show that it specializes to the
Tamagawa number introduced by Peyre in the context of Manin's conjectures about
rational points of bounded height on Fano varieties.


title: Any sub-Riemannian Metric has Points of Smoothness

abstract:
  We prove the result stated in the title; it is equivalent to the existence of
a regular point of the sub-Riemannian exponential mapping. We also prove that
the metric is analytic on an open everywhere dense subset in the case of a
complete real-analytic sub-Riemannian manifold.


title: TrustMAS: Trusted Communication Platform for Multi-Agent Systems

abstract:
  The paper presents TrustMAS - Trusted Communication Platform for Multi-Agent
Systems, which provides trust and anonymity for mobile agents. The platform
includes anonymous technique based on random-walk algorithm for providing
general purpose anonymous communication for agents. All agents, which take part
in the proposed platform, benefit from trust and anonymity that is provided for
their interactions. Moreover, in TrustMAS there are StegAgents (SA) that are
able to perform various steganographic communication. To achieve that goal, SAs
may use methods in different layers of TCP/IP model or specialized middleware
enabling steganography that allows hidden communication through all layers of
mentioned model. In TrustMAS steganographic channels are used to exchange
routing tables between StegAgents. Thus all StegAgents in TrustMAS with their
ability to exchange information by using hidden channels form distributed
steganographic router (Stegrouter).


title:
Frequency Metrology on single trapped ions in the weak binding limit:
  The 3s1/2-3p3/2 transition in 24-Mg+

abstract:
  We demonstrate a method for precision spectroscopy on trapped ions in the
limit of unresolved motional sidebands. By sympathetic cooling of a chain of
crystallized ions we suppress adverse temperature variations induced by the
spectroscopy laser that usually lead to a distorted line profle and obtain a
Voigt profile with negligible distortions. We applied the method to measure the
absolute frequency of the astrophysically relevant D2 transition in single
24-Mg+ ions and find 1072082934.33(16)MHz, a nearly 400fold improvement over
previous results. Further, we find the excited state lifetime to be 3.84(10)
ns.


title: Ensembles related to the rich-club coefficient for non-evolving networks

abstract:
  In complex networks the rich nodes are the subset of nodes with high degree.
These well connected nodes tend to dominate the organisation of the network's
structure. In non-evolving networks, a reference network has been used to
detect if the connectivity between the rich nodes is due to chance or caused by
an unknown mechanism. Chance is represented as a reference network obtained
from an ensemble of networks. When compared with the original network the
reference network discounts suggests the existence of a well connected rich
club beyond structural constraints. Here we revise some of the properties of
the ensemble obtained by conserving only the degree distribution and introduce
two new reference networks to study the importance of the rich nodes as
organisers of the network structure. The first reference network is obtained
from an ensemble of networks where all the members of the ensemble have the
same rich--club coefficient. The reference network obtained from the ensemble
is assortative. We propose that this reference network can be used to study
networks where assortativness is a fundamental property, a common case in many
social networks. The second reference network is obtained from an ensemble
where the members of the ensemble all have the same probability degree
distribution and rich-club coefficient. The reference network obtained from
this ensemble has a very similar structure to the original network. This
ensemble can be used to quantify correlations between the rich nodes and
pinpoint which links are the backbone of the network's structure.


title:
Magnetic Order in Kondo-Lattice Systems due to Electron-Electron
  Interactions

abstract:
  The hyperfine interaction between the electron spin and the nuclear spins is
one of the main sources of decoherence for spin qubits when the nuclear spins
are disordered. An ordering of the latter largely suppresses this source of
decoherence. Here we show that such an ordering can occur through a
thermodynamic phase transition in two-dimensional (2D) Kondo-lattice type
systems. We specifically focus on nuclear spins embedded in a 2D electron gas.
The nuclear spins interact with each other through the RKKY interaction, which
is carried by the electron gas. We show that a nuclear magnetic order at finite
temperature relies on the anomalous behavior of the 2D static electron spin
susceptibility due to electron-electron interactions. This provides a
connection between low-dimensional magnetism and non-analyticities in
interacting 2D electron systems. We discuss the conditions for nuclear
magnetism, and show that the associated Curie temperature increases with the
electron-electron interactions and may reach up into the millikelvin regime.
The further reduction of dimensionality to one dimension is shortly discussed.


title:
Reprocessing of X-rays in the outer accretion disc of the black hole
  binary XTE J1817--330

abstract:
  We build a simple model of the optical/UV emission from irradiation of the
outer disc by the inner disc and coronal emission in black hole binaries. We
apply this to the broadband Swift data from the outburst of the black hole
binary XTE J1817--330 to confirm previous results that the optical/UV emission
in the soft state is consistent with a reprocessing a constant fraction of the
bolometric X-ray luminosity. However, this is very surprising as the disc
temperature drops by more than a factor 3 in the soft state, which should
produce a marked change in the reprocessing efficiency. The easiest way to
match the observed constant reprocessed fraction is for the disc skin to be
highly ionized (as suggested 30 years ago by van Paradijs), so that the bulk of
the disc flux is reflected and only the hardest X-rays heat the disc. The
constant reprocessed fraction also favours direct illumination of the disc over
a scattering origin as the optical depth/solid angle of any scattering material
(wind/corona) over the disc should decrease as the source luminosity declines.
By contrast, the reprocessed fraction increases very significantly (by a factor
~6) as the source enters the hard state. This dramatic change is not evident
from X-ray/UV flux correlations as it is masked by bandpass effects. However,
it does not necessarily signal a change in emission e.g. the emergence of the
jet dominating the optical/UV flux as the reflection albedo must change with
the dramatic change in spectral shape.


title:
Mass measurements in the vicinity of the rp-process and the nu p-process
  paths with JYFLTRAP and SHIPTRAP

abstract:
  The masses of very neutron-deficient nuclides close to the astrophysical rp-
and nu p-process paths have been determined with the Penning trap facilities
JYFLTRAP at JYFL/Jyv\"askyl\"a and SHIPTRAP at GSI/Darmstadt. Isotopes from
yttrium (Z = 39) to palladium (Z = 46) have been produced in heavy-ion
fusion-evaporation reactions. In total 21 nuclides were studied and almost half
of the mass values were experimentally determined for the first time: 88Tc,
90-92Ru, 92-94Rh, and 94,95Pd. For the 95Pdm, (21/2^+) high-spin state, a first
direct mass determination was performed. Relative mass uncertainties of
typically $\delta m / m = 5 \times 10^{-8}$ were obtained. The impact of the
new mass values has been studied in nu p-process nucleosynthesis calculations.
The resulting reaction flow and the final abundances are compared to those
obtained with the data of the Atomic Mass Evaluation 2003.


title:
The Ground State Energy of Dilute Bose Gas in Potentials with Positive
  Scattering Length

abstract:
  The leading term of the ground state energy/particle of a dilute gas of
bosons with mass $m$ in the thermodynamic limit is $2\pi \hbar^2 a \rho/m$ when
the density of the gas is $\rho$, the interaction potential is non-negative and
the scattering length $a$ is positive. In this paper, we generalize the upper
bound part of this result to any interaction potential with positive scattering
length, i.e, $a>0$ and the lower bound part to some interaction potentials with
shallow and/or narrow negative parts.


title: The diameter of sparse random graphs

abstract:
  In this paper we study the diameter of the random graph $G(n,p)$, i.e., the
the largest finite distance between two vertices, for a wide range of functions
$p=p(n)$. For $p=\la/n$ with $\la>1$ constant, we give a simple proof of an
essentially best possible result, with an $O_p(1)$ additive correction term.
Using similar techniques, we establish 2-point concentration in the case that
$np\to\infty$. For $p=(1+\epsilon)/n$ with $\epsilon\to 0$, we obtain a
corresponding result that applies all the way down to the scaling window of the
phase transition, with an $O_p(1/\epsilon)$ additive correction term whose
(appropriately scaled) limiting distribution we describe. Combined with earlier
results, our new results complete the determination of the diameter of the
random graph $G(n,p)$ to an accuracy of the order of its standard deviation (or
better), for all functions $p=p(n)$. Throughout we use branching process
methods, rather than the more common approach of separate analysis of the
2-core and the trees attached to it.


title: Method of accelerator search for dark matter

abstract:
  A method to search for dark matter by studying the interaction of accelerator
beam particles with residual gas in dependence on gas pressure is proposed. The
sensitivity of the method is estimated.


title: On a question of Goss

abstract:
  In this note we answer the question raised by D. Goss in [Applications of
non-Archimedean integration to the $L$-series of $\tau$-sheaves, {\em J. Number
Theory,} 110 (2005), no. 1, 83--113] by proving that the group of locally
analytic endomorphisms on the 1-units of a locally compact field of
characteristic $p>0$ is isomorphic to the $p$-adic integers.


title:
Surface fraction of random close packing in two dimensions calculated
  exactly

abstract:
  The random close packing fraction in two dimensions is calculated exactly via
the central limit theorem and the brownian motion with no gain between
monodisperse disks.


title: Factoriality of complete intersection threefolds

abstract:
  Let X be a complete intersection of two hypersurfaces F_n and F_k in the
projective space P^5 of degree n and k respectively with n >= k, such that the
singularities of X are nodal and F_k is smooth. We prove that if the threefold
X has at most (n+k-2)(n-1)-1 singular points, then it is factorial.


title: Hyperconjugative Effect on the Electronic Wavefunctions of Ethanol

abstract:
  Hyperconjugation is a basic conception of chemistry. Its straightforward
effect is exhibited by the spatial delocalization characteristics of the
electron density distributions or wavefunctions. Such effects on the electron
wavefunctions of the highest-occupied molecular orbitals (HOMO) of two ethanol
conformers are demonstrated with electron momentum spectroscopy together with
natural bond orbital analyses, exhibiting the distinctly different symmetries
of the HOMO wavefunctions in momentum space.


title: Longitudinal SDW order in a quasi-1D Ising-like quantum antiferromagnet

abstract:
  From neutron diffraction measurements on a quasi-1D Ising-like Co$^{\rm 2+}$
spin compound BaCo$_{\rm 2}$V$_{\rm 2}$O$_{\rm 8}$, we observed an appearance
of a novel type of incommensurate ordering in magnetic fields. This ordering is
essentially different from the N{\' e}el-type ordering, which is expected for
the classical system, and is caused by quantum fluctuation inherent in the
quantum spin chain. A Tomonaga-Luttinger liquid (TLL) nature characteristic of
the gapless quantum 1D system is responsible for the realization of the
incommensurate ordering.


title:
Persistence in the zero-temperature dynamics of the $Q$-states Potts
  model on undirected-directed Barab\'asi-Albert networks and Erd\"os-R\'enyi
  random graphs

abstract:
  The zero-temperature Glauber dynamics is used to investigate the persistence
probability $P(t)$ in the Potts model with $Q=3,4,5,7,9,12,24,64, 128$, $256,
512, 1024,4096,16384 $,..., $2^{30}$ states on {\it directed} and {\it
undirected} Barab\'asi-Albert networks and Erd\"os-R\'enyi random graphs. In
this model it is found that $P(t)$ decays exponentially to zero in short times
for {\it directed} and {\it undirected} Erd\"os-R\'enyi random graphs. For {\it
directed} and {\it undirected} Barab\'asi-Albert networks, in contrast it
decays exponentially to a constant value for long times, i.e, $P(\infty)$ is
different from zero for all $Q$ values (here studied) from $Q=3,4,5,...,
2^{30}$; this shows "blocking" for all these $Q$ values. Except that for
$Q=2^{30}$ in the {\it undirected} case $P(t)$ tends exponentially to zero;
this could be just a finite-size effect since in the other "blocking" cases you
may have only a few unchanged spins.


title: Unparticle signals with a few particles

abstract:
  We use Pade approximants to systematically approximate scalar unparticle
propagators and their associated phase factors by a finite number of ordinary
particles. This is possible for conformal dimensions 1<d<2, and also for d>2 if
we add local terms. A small number of particles can, in some cases, mimic
unparticle signals. We also discuss how the approximants capture basic
unparticle properties.


title: Lectures on Gauged Supergravity and Flux Compactifications

abstract:
  The low-energy effective theories describing string compactifications in the
presence of fluxes are so-called gauged supergravities: deformations of the
standard abelian supergravity theories. The deformation parameters can be
identified with the various possible (geometric and non-geometric) flux
components. In these lecture notes we review the construction of gauged
supergravities in a manifestly duality covariant way and illustrate the
construction in several examples.


title: Association of ultracold double-species bosonic molecules

abstract:
  We report on the creation of heterospecies bosonic molecules, associated from
an ultracold Bose-Bose mixture of 41K and 87Rb, by using a resonantly modulated
magnetic field close to two Feshbach resonances. We measure the binding energy
of the weakly bound molecular states versus the Feshbach field and compare our
results to theoretical predictions. We observe the broadening and asymmetry of
the association spectrum due to thermal distribution of the atoms, and a
frequency shift occurring when the binding energy depends nonlinearly on the
Feshbach field. A simple model is developed to quantitatively describe the
association process. Our work marks an important step forward in the
experimental route towards Bose-Einstein condensates of dipolar molecules.


title:
On collisions driven negative energy waves and Weibel instability of a
  relativistic electron beam in a quasi-neutral plasma

abstract:
  A new quasi-neutral model describing the Weibel instability of a high-current
relativistic beam propagating through a resistive plasma is developed. It
treats beam electrons as kinetic particles, and ambient plasma as a
non-relativistic fluid. For a finite-temperature beam, a new class of negative
energy magneto-sound waves is identified, which can possess negative energy.
Their growth due to collisional dissipation in the cold return current
destabilizes the beam-plasma system even for high beam temperatures. We perform
detailed two- and three-dimensional particle-in-cell (PIC) simulations of the
thermal beam and collisional plasma. It is shown that in three dimensions, the
Weibel instability persists even for physically collisionless background
plasma. The anomalous plasma resistivity is then caused by the two-stream
instability.


title: From Altruism to Non-Cooperation in Routing Games

abstract:
  The paper studies the routing in the network shared by several users. Each
user seeks to optimize either its own performance or some combination between
its own performance and that of other users, by controlling the routing of its
given flow demand. We parameterize the degree of cooperation which allows to
cover the fully non-cooperative behavior, the fully cooperative behavior, and
even more, the fully altruistic behavior, all these as special cases of the
parameter's choice. A large part of the work consists in exploring the impact
of the degree of cooperation on the equilibrium. Our first finding is to
identify multiple Nash equilibria with cooperative behavior that do not occur
in the non-cooperative case under the same conditions (cost, demand and
topology). We then identify Braess like paradox (in which adding capacity or
adding a link to a network results in worse performance to all users) and study
the impact of the degree of cooperation on it. We identify another type of
paradox in cooperation scenario. We identify that when we increase the degree
of cooperation of a user while other users keep unchanged their degree of
cooperation, leads to an improvement in performance of that user. We then
pursue the exploration and carry it on to the setting of Mixed equilibrium
(i.e. some users are non atomic-they have infinitesimally small demand, and
other have finite fixed demand). We finally obtain some theoretical results
that show that for low degree of cooperation the equilibrium is unique,
confirming the results of our numerical study.


title: On the ergoregion instability in rotating gravastars

abstract:
  The ergoregion instability is known to affect very compact objects that
rotate very rapidly and do not possess a horizon. We present here a detailed
analysis on the relevance of the ergoregion instability for the viability of
gravastars. Expanding on some recent results, we show that not all rotating
gravastars are unstable. Rather, stable models can be constructed also with
J/M^2 ~ 1, where J and M are the angular momentum and mass of the gravastar,
respectively. The genesis of gravastars is still highly speculative and
fundamentally unclear if not dubious. Yet, their existence cannot be ruled out
by invoking the ergoregion instability. For the same reason, not all
ultra-compact astrophysical objects rotating with J/M^2 <~ 1 are to be
considered necessarily black holes.


title:
Numerical modelling of the effect of weathering on the progressive
  failure of underground limestone mines

abstract:
  The observations show that the collapse of underground limestone mines
results from a progressive failure due to gradual weathering of the rockmass.
The following stages can be considered for the limestone weathering and
degradation process in underground mines: condensation of the water on the roof
of the gallery, infiltration of water in the porous rock, migration of the air
CO2 molecules in the rock pore water by convection and molecular diffusion,
dissolution of limestone by CO2 rich water and consequently, reduction of the
strength properties of rock. Considering this process, a set of equations
governing different hydrochemo-mechanical aspects of the weathering phenomenon
and progressive failure occurring in these mines is presented. Then the
feasibility of numerical modelling of this process is studied and a simple
example of application is presented.


title: Split Orders and Convex Polytopes in Buildings

abstract:
  As part of his work to develop an explicit trace formula for Hecke operators
on congruence subgroups of $SL_2(\Z)$, Hijikata defines and characterizes the
notion of a split order in $M_2(k)$, where $k$ is a local field. In this paper,
we generalize the notion of a split order to $M_n(k)$ for $n>2$ and give a
natural geometric characterization in terms of the affine building for
$SL_n(k)$. In particular, we show that there is a one-to-one correspondence
between split orders in $M_n(k)$ and a collection of convex polytopes in
apartments of the building such that the split order is the intersection of all
the maximal orders representing the vertices in the polytope. This generalizes
the geometric interpretation in the $n=2$ case in which split orders correspond
to geodesics in the tree for $SL_2(k)$ with the split order given as the
intersection of the endpoints of the geodesic.


title:
Poromechanical behaviour of hardened cement paste under isotropic
  loading

abstract:
  The poromechanical behaviour of hardened cement paste under isotropic loading
is studied on the basis of an experimental testing program of drained,
undrained and unjacketed compression tests. The macroscopic behaviour of the
material is described in the framework of the mechanics of porous media. The
poroelastic parameters of the material are determined and the effect of stress
and pore pressure on them is evaluated. Appropriate effective stress laws which
control the evolution of total volume, pore volume, solid volume, porosity and
drained bulk modulus are discussed. A phenomenon of degradation of elastic
properties is observed in the test results. The microscopic observations showed
that this degradation is caused by the microcracking of the material under
isotropic loading. The good compatibility and the consistency of the obtained
poromechanical parameters demonstrate that the behaviour of the hardened cement
paste can be indeed described within the framework of the theory of porous
media.


title: Effective stress law for the permeability of a limestone

abstract:
  The effective stress law for the permeability of a limestone is studied
experimentally by performing constant head permeability tests in a triaxial
cell with different conditions of confining pressure and pore pressure. Test
results have shown that a pore pressure increase and a confining pressure
decrease both result in an increase of the permeability, and that the effect of
the pore pressure change on the variation of the permeability is more important
than the effect of a change of the confining pressure. A power law is proposed
for the variation of the permeability with the effective stress. The
permeability effective stress coefficient increases linearly with the
differential pressure and is greater than one as soon the differential pressure
exceeds few bars. The test results are well reproduced using the proposed
permeability-effective stress law. A conceptual pore-shell model based on a
detailed observation of the microstructure of the studied limestone is
proposed. This model is able to explain the experimental observations on the
effect of the total stress and of the pore pressure on the permeability of the
limestone. Effective stress coefficients for the stress-dependent permeability
which are greater than one are obtained. It is shown that the controlling
factor is the ratio of the different bulk moduli of the various constituents of
the rock. This ratio is studied experimentally by performing microhardness
tests.


title: Signature of Primordial Non-Gaussianity on Matter Power Spectrum

abstract:
  Employing the perturbative treatment of gravitational clustering, we discuss
possible effects of primordial non-Gaussianity on the matter power spectrum. As
gravitational clustering develops, the coupling between different Fourier modes
of density perturbations becomes important and the primordial non-Gaussianity
which intrinsically possesses a non-trivial mode-correlation can affect the
late-time evolution of the power spectrum. We quantitatively estimate the
non-Gaussian effect on power spectrum from the perturbation theory. The
potential impact on the cosmological parameter estimation using the power
spectrum are investigated based on the Fisher-matrix formalism. In addition, on
the basis of the local biasing prescription, non-Gaussian effects on the galaxy
power spectrum are considered, showing that the scale-dependent biasing arises
from a local-type primordial non-Gaussianity. On the other hand, an
equilateral-type non-Gaussianity does not induce such scale-dependence because
of weaker mode-correlations between small and large Fourier modes.


title:
A novel method for measuring the extragalactic background light: Fermi
  application to the lobes of Fornax A

abstract:
  We describe a new method for measuring the extragalactic background light
(EBL) through the detection of $\gamma$-ray inverse Compton (IC) emission due
to scattering of the EBL photons off relativistic electrons in the lobes of
radio galaxies. Our method has no free physical parameters and is a powerful
tool when the lobes are characterized by a high energy sharp break or cutoff in
their electron energy distribution (EED). We show that such a feature will
produce a high energy IC `imprint' of the EBL spectrum in which the radio lobes
are embedded, and show how this imprint can be used to derive the EBL. We apply
our method to the bright nearby radio galaxy Fornax A, for which we
demonstrate, using WMAP and EGRET observations, that the EED of its lobes is
characterized by a conveniently located cutoff, bringing the IC EBL emission
into the {\sl Fermi} energy range. We show that {\sl Fermi} will set upper
limits to the optical EBL and measure the more elusive infrared EBL.


title: Comments on claimed risk from metastable black holes

abstract:
  In a recent note, arXiv:0808.1415, it was argued that a hypothetical
metastable black hole scenario could pose collider risk not excluded by our
previous study. We comment on inconsistency of this proposed scenario.


title: Affine model of stress stiffening in semiflexible filament networks

abstract:
  We present a revised theoretical study of the affine assumption applied to
semiflexible networks. Drawing on simple models of semiflexible worm-like
chains we derive an expression for the probability distribution of crosslink
separations valid at all separations. This accounts for both entropic and
mechanical filament stretching. From this we obtain the free energy density of
such networks explicitly as a function of applied strain. We are therefore able
to calculate the elastic moduli of such networks for any imposed strain or
stress. We find that accounting for the distribution of cross-link separations
destroys the simple scaling of modulus with stress that is well known in single
chains, and that such scaling is sensitive to the mechanical stretch modulus of
individual filaments. We compare this model to three experimental data sets,
for networks of different types of filaments, and find that a properly treated
affine model can successfully account for the data. We find that for networks
of stiffer filaments, such as F-actin, to fit data we require a much smaller
effective persistence length than usually assumed to be characteristic of this
filament type. We propose that such an effectively reduced rigidity of
filaments might be a consequence of network formation.


title: Maximum stellar mass versus cluster membership number revisited

abstract:
  We have made a new compilation of observations of maximum stellar mass versus
cluster membership number from the literature, which we analyse for consistency
with the predictions of a simple random drawing hypothesis for stellar mass
selection in clusters. Previously, Weidner and Kroupa have suggested that the
maximum stellar mass is lower, in low mass clusters, than would be expected on
the basis of random drawing, and have pointed out that this could have
important implications for steepening the integrated initial mass function of
the Galaxy (the IGIMF) at high masses. Our compilation demonstrates how the
observed distribution in the plane of maximum stellar mass versus membership
number is affected by the method of target selection; in particular, rather low
n clusters with large maximum stellar masses are abundant in observational
datasets that specifically seek clusters in the environs of high mass stars.
Although we do not consider our compilation to be either complete or unbiased,
we discuss the method by which such data should be statistically analysed. Our
very provisional conclusion is that the data is not indicating any striking
deviation from the expectations of random drawing.


title: Reduced and projected two-particle entanglement at finite temperatures

abstract:
  We present a theory for two-particle entanglement production and detection in
mesoscopic conductors at finite temperature. In contrast to the zero
temperature limit, the entanglement of the density matrix projected out of the
emitted many-body state is different from the entanglement of the reduced
density matrix, detectable by current correlation measurements. We show that
under very general conditions the reduced entanglement constitutes a lower
bound for the projected entanglement. Applying the theory to the recent
experiment [Neder et al, Nature 448 333 (2007)] on a fermionic Hanbury Brown
Twiss two-particle interferometer we find that despite an appreciable
entanglement production in the experiment, the detectable entanglement is close
to zero.


title: PEL Modulispaces without $\mathbb C$-valued points

abstract:
  We give several new moduli interpretations of the fibers of certain Shimura
varieties over several prime numbers. As a corollary we obtain that for every
prescribed odd prime characteristic $p$ every bounded symmetric domain
possesses quotients by arithmetic groups whose models have good reduction at a
prime divisor of $p$.


title: Loss and Recovery of Gibbsianness for XY models in external fields

abstract:
  We consider planar rotors (XY spins) in $\mathbb{Z}^d$, starting from an
initial Gibbs measure and evolving with infinite-temperature stochastic
(diffusive) dynamics. At intermediate times, if the system starts at low
temperature, Gibbsianness can be lost. Due to the influence of the external
initial field, Gibbsianness can be recovered after large finite times. We prove
some results supporting this picture.


title: What will be the maximum Tc in the iron-based superconductors?

abstract:
  Using the newly developed real space vortex-lattice based theory of
superconductivity, we study the maximum superconducting transition temperature
(T_{c}^{\max}) in the iron-based superconductors. We find that all the reported
FeAs superconductors can be divided into two basic classes (c/a=3 and c/a=5/2)
depending on the lattice constants, where a is the Fe-Fe distance in the
xy-plane and c is the Fe-Fe layer distance along the z-axis. Our results
suggest that the former class has a maximum T_{c}^{\max}<60K, while the latter
class has a lower T_{c}^{\max}\leq 40K. Our investigations further indicate
that, in order to enhance T_{c}^{\max} in this family of compounds, new class
of superconductors with a larger ratio of c/a should be synthesized. It is
likely that their T_{c}^{\max} values could be raised into the liquid nitrogen
range (77K) and 100K, supposing the new analogues with c/a=5 (approximately
c>13A, if a=2.750A) and c/a=11 (c>31A) can be experimentally achieved,
respectively. For the new FeSe series, our mechanism predicts that their
T_{c}^{\max} is impossible to exceed 30 K due to a relatively shorter c-axis
lattice constant (c/a=2). Finally, based on the new experimental results
(arXiv:0811.0094 and arXiv:0811.2205), the possible ways to raise the Tc of the
iron-based superconductors into 70 K are also suggested.


title: Entanglement Entropy and Twist Fields

abstract:
  The entanglement entropy of a subsystem of a quantum system is expressed, in
the replica approach, through analytic continuation with respect to n of the
trace of the n-th power of the reduced density matrix. This trace can be
thought of as the vacuum expectation value of a suitable observable in a system
made with n independent copies of the original system. We use this property to
numerically evaluate it in some two-dimensional critical systems, where it can
be compared with the results of Calabrese and Cardy, who wrote the same
quantity in terms of correlation functions of twist fields of a conformal field
theory. Although the two calculations match perfectly even in finite systems
when the analyzed subsystem consists of a single interval, they disagree
whenever the subsystem is composed of more than one connected part. The reasons
of this disagreement are explained.


title:
Origin of multiple stellar populations in globular clusters and their
  helium enrichment

abstract:
  The various scenarios proposed for the origin of the multiple,
helium-enriched populations in massive globular clusters are critically
compared to the relevant constraining observations. Among accretion of
helium-rich material by pre-existing stars, star formation out of ejecta from
massive AGB stars or from fast rotating massive stars, and pollution by
Population III stars, only the AGB option appears to be viable. Accretion or
star formation out of outflowing disks would result in a spread of helium
abundances, thus failing to produce the distinct, chemically homogeneous
sub-populations such as those in the clusters $\omega$ Cen and NGC 2808.
Pollution by Population III stars would fail to produce sub-populations
selectively enriched in helium, but maintaining the same abundance of heavy
elements. Still, it is argued that for the AGB option to work two conditions
should be satisfied: i) AGB stars experiencing the hot bottom burning process
(i.e., those more massive than $\sim 3 \msun$) should rapidly eject their
envelope upon arrival on the AGB, thus experiencing just a few third dredge-up
episodes, and ii) clusters with multiple, helium enriched populations should be
the remnants of much more massive systems, such as nucleated dwarf galaxies, as
indeed widely assumed.


title: Recent high-pt results from STAR

abstract:
  We present selected recent results of multi-hadron correlation measurements
in azimuth and pseudorapidity at intermediate and high \pt{} in Au+Au
collisions at $\sqrt{s_{NN}}=200$ GeV, from the STAR experiment at RHIC. At
intermediate \pt, measurements are presented that attempt to determine the
origin of the associated near-side (small \dphi) yield at large pseudo-rapidity
difference \deta{} that is found to be present in heavy ion collisions. In
addition, results are reported on new multi-hadron correlation measures at
high-\pt{} that use di-hadron triggers and multi-hadron cluster triggers with
the goal to constrain the underlying jet kinematics better than in the existing
measurements of inclusive spectra and di-hadron correlations.


title:
Emission line activity in type 2 quasars from the Sloan Digital Sky
  Survey

abstract:
  We have compared the optical emission line ratios of type 2 quasars from
Zakamska et al. with standard AGN photoionization model predictions, Seyfert
2s, HII galaxies, and narrow line FRII radio galaxies. Moderate to high
ionization narrow line radio galaxies and Seyfert 2s are indistinguishable from
type 2 quasars based on their optical line ratios.
  The standard AGN photoionization models, widely discussed for other type 2
AGNs, can reproduce successfully the loci and trends of type 2 quasars in some
of the main diagnostic diagrams. These models are not exempt of problems and
the discrepancies with the data are the same encountered for other type 2 AGNs.
As for these, realistic models must take into account a range of cloud
properties, as widely demonstrated in the literature.
  We also study the possible impact of stellar photoionization.


title: State reduction dynamics in a simplified QED model

abstract:
  A simplified model of quantum electrodynamics involving a charged two-state
system interacting with an electromagnetic field mode is examined. By extending
the Schrodinger equation to include stochastic and nonlinear terms the
dynamical process of quantum state reduction can be represented. A specific
choice of modified Schrodinger dynamics is shown to result in stable coherent
field states. The two-state system undergoes an induced state reduction to a
generalised current state due to its interaction with the field mode. Numerical
results are presented demonstrating state reduction dynamics for an initial
superposition of two current states. An induced reduction time-scale for the
two-state system is derived and confirmed by the numerics.


title:
The Influence of Concentration and Dynamical State on Scatter in the
  Galaxy Cluster Mass-Temperature Relation

abstract:
  Using a hydrodynamics plus N-body simulation of galaxy cluster formation
within a large volume and mock Chandra X-ray observations, we study the form
and evolution of the intrinsic scatter about the best-fit X-ray
temperature-mass relation for clusters. We investigate the physical origin of
the scatter by correlating it with quantities that are closely related to
clusters' formation and merging histories. We also examine the distribution of
the scatter for merging and nonmerging populations, identified using halo
merger trees derived from the simulation as well as X-ray substructure
measures. We find a strong correlation between the scatter in the M-T_X
relation and the halo concentration, in the sense that more concentrated
clusters tend to be cooler than clusters with similar masses. No bias is found
between the merging and relaxed clusters, but merging clusters generally have
greater scatter, which is related to the properties of the distribution of halo
concentrations. We also detect a signature of non-lognormality in the
distribution of scatter for our simulated clusters both at z=0 and at z=1. A
detailed comparison of merging clusters identified by substructure measures and
by halo merger trees is given in the discussion. We conclude that, when
cooling-related effects are neglected, the variation in halo concentrations is
a more important factor for driving the intrinsic scatter in the M-T_X
relation, while departures from hydrostatic equilibrium due to cluster mergers
have a minor effect.


title: Codes and Noncommutative Stochastic Matrices

abstract:
  Given a matrix over a skew field fixing the column (1,...,1)^t, we give
formulas for a row vector fixed by this matrix. The same techniques are applied
to give noncommutative extensions of probabilistic properties of codes.


title:
Are ring galaxies the ancestors of giant low surface brightness
  galaxies?

abstract:
  Giant low surface brightness galaxies (GLSBs) have flat discs extending up to
~100 kpc. Their formation is a puzzle for cosmological simulations in the cold
dark matter scenario. We suggest that GLSBs might be the final product of the
evolution of collisional ring galaxies. In fact, our simulations show that,
approximately 0.5-1.5 Gyr after the collision which led to the formation of the
ring galaxy, the ring keeps expanding and fades, while the disc becomes very
large (~100 kpc) and flat. At this stage, our simulated galaxies match many
properties of GLSBs (surface brightness profile, morphology, HI spectrum and
rotation curve).


title: The ATLAS trigger menu for early data-taking

abstract:
  The ATLAS trigger system is based on three levels of event selection that
select the physics of interest from an initial bunch-crossing rate of 40 MHz.
During nominal LHC operations at a luminosity of 10^34 cm^-2 s^-1, decisions
must be taken every 25 ns with each bunch crossing containing about 23
interactions. The selections in the three trigger levels must provide
sufficient rejection to reduce the rate down to 200 Hz, compatible with the
offline computing power and storage capacity. The LHC is expected to begin
operations in summer 2008 with a peak luminosity of 10^31 cm^-2 s^-1 with far
fewer bunches than nominal running, but quickly ramp up to higher luminosities.
Hence, we need to deploy trigger selections that can adapt to the changing beam
conditions preserving the interesting physics and detector requirements that
may vary with these conditions.
  We present the status of the preparation of the trigger menu for the early
data-taking showing how we plan to deploy the trigger system from the first
collision to the nominal luminosity. We also show expected rates and physics
performance obtained from simulated data.


title:
Spin-wave mediated quantum corrections to the conductivity in thin
  ferromagnetic gadolinium films

abstract:
  We present a study of quantum corrections to the conductivity of thin
ferromagnetic gadolinium films. In situ magneto-transport measurements were
performed on a series of thin films with thickness d < 135A. For sheet
resistances R0 < 4011 Ohm and temperatures T < 30K, we observe a linear
temperature dependence of the conductivity in addition to the logarithmic
temperature dependence expected from well known quantum corrections in two
dimensions. We show that such a linear T-dependence can arise from a spin-wave
mediated Altshuler-Aronov type correction.


title: Flow-level Characteristics of Spam and Ham

abstract:
  Despite a large amount of effort devoted in the past years trying to limit
unsolicited mail, spam is still a major global concern. Content-analysis
techniques and blacklists, the most popular methods used to identify and block
spam, are beginning to lose their edge in the battle. We argue here that one
not only needs to look into the network-related characteristics of spam
traffic, as has been recently suggested, but also to look deeper into the
network core, in order to counter the increasing sophistication of spam-ing
methods. Yet, at the same time, local knowledge available at a given server can
often be irreplaceable in identifying specific spammers. To this end, in this
paper we show how the local intelligence of mail servers can be gathered and
correlated pas- sively at the ISP-level providing valuable network-wide
information. Specifically, we use first a large network flow trace from a
medium size, national ISP, to demonstrate that the pre-filtering decisions of
individual mail servers can be tracked and combined at the flow level. Then, we
argue that such aggregated knowledge not only can allow ISPs to develop and
evaluate powerful new methods for fighting spam, but also to monitor remotely
what their own servers are doing.


title:
Reference grids of stellar models and oscillation frequencies: Data from
  the CESAM stellar evolution code and ADIPLS oscillation programme

abstract:
  We present grids of stellar models and their associated oscillation
frequencies that have been used by the CoRoT Seismology Working Group during
the scientific preparation of the CoRoT mission. The stellar models have been
calculated with the CESAM stellar internal structure and evolution code while
the oscillation frequencies have been obtained from the CESAM models by means
of the ADIPLS adiabatic oscillation programme. The grids cover a range of
masses, chemical compositions and evolutionary stages corresponding to those of
the CoRoT primary targets. The stellar models and oscillation frequencies are
available on line through the Evolution and Seismic Tools Activity (ESTA) web
site.


title: Interacting Field Theories in de Sitter Space are Non-Unitary

abstract:
  It is well known that there should be a total cancellation of the IR
divergences in unitary interacting field theories, such as QED and gravity. The
cancellation should be at all orders between loop and tree level contributions
to cross--sections. This is the crucial fact related to the unitarity of the
evolution operator (S--matrix) of the underlying interacting field theory. In
this note we show that such a cancellation does {\it not} happen in de Sitter
space.


title: Telescope interferometers: an alternative to classical wavefront sensors

abstract:
  Several types of Wavefront Sensors (WFS) are nowadays available in the field
of Adaptive Optics (AO). Generally speaking, their basic principle consists in
measuring slopes or curvatures of Wavefront Errors (WFE) transmitted by a
telescope, subsequently reconstructing WFEs digitally. Such process, however,
does not seem to be well suited for evaluating co-phasing or piston errors of
future large segmented telescopes in quasi real-time. This communication
presents an original, recently proposed technique for direct WFE sensing. The
principle of the device, which is named "Telescope-Interferometer" (TI), is
based on the addition of a reference optical arm into the telescope pupil
plane. Then incident WFEs are deduced from Point Spread Function (PSF)
measurements at the telescope focal plane. Herein are described two different
types of TIs, and their performance are discussed in terms of intrinsic
measurement accuracy and spatial resolution. Various error sources are studied
by means of numerical simulations, among which photon noise sounds the most
critical. Those computations finally help to define the application range of
the TI method in an AO regime, including main and auxiliary telescope diameters
and magnitude of the guide star. Some practical examples of optical
configurations are also described and commented.


title: A Thomason Model Structure on the Category of Small n-fold Categories

abstract:
  We construct a cofibrantly generated Quillen model structure on the category
of small n-fold categories and prove that it is Quillen equivalent to the
standard model structure on the category of simplicial sets. An n-fold functor
is a weak equivalence if and only if the diagonal of its n-fold nerve is a weak
equivalence of simplicial sets. This is an n-fold analogue to Thomason's
Quillen model structure on Cat. We introduce an n-fold Grothendieck
construction for multisimplicial sets, and prove that it is a homotopy inverse
to the n-fold nerve. As a consequence, we completely prove that the unit and
counit of the adjunction between simplicial sets and n-fold categories are
natural weak equivalences.


title:
A note on cyclic semiregular subgroups of some 2-transitive permutation
  groups

abstract:
  We determine the semi-regular subgroups of the 2-transitive permutation
groups PGL(2,n), PSL(2,n), PGU(3,n), PSU(3,n), Sz(n) and Ree(n) with n a
suitable power of a prime number p.


title: Quantum ergodicity on graphs

abstract:
  We investigate the equidistribution of the eigenfunctions on quantum graphs
in the high-energy limit. Our main result is an estimate of the deviations from
equidistribution for large well-connected graphs. We use an exact
field-theoretic expression in terms of a variant of the supersymmetric
nonlinear sigma-model. Our estimate is based on a saddle-point analysis of this
expression and leads to a criterion for when equidistribution emerges
asymptotically in the limit of large graphs. Our theory predicts a rate of
convergence that is a significant refinement of previous estimates,
long-assumed to be valid for quantum chaotic systems, agreeing with them in
some situations but not all. We discuss specific examples for which the theory
is tested numerically.


title: Relative Entropy and Statistics

abstract:
  Formalising the confrontation of opinions (models) to observations (data) is
the task of Inferential Statistics. Information Theory provides us with a basic
functional, the relative entropy (or Kullback-Leibler divergence), an
asymmetrical measure of dissimilarity between the empirical and the theoretical
distributions. The formal properties of the relative entropy turn out to be
able to capture every aspect of Inferential Statistics, as illustrated here,
for simplicity, on dices (= i.i.d. process with finitely many outcomes):
refutability (strict or probabilistic): the asymmetry data / models; small
deviations: rejecting a single hypothesis; competition between hypotheses and
model selection; maximum likelihood: model inference and its limits; maximum
entropy: reconstructing partially observed data; EM-algorithm; flow data and
gravity modelling; determining the order of a Markov chain.


title:
Manifest Ultraviolet Behavior for the Three-Loop Four-Point Amplitude of
  N=8 Supergravity

abstract:
  Using the method of maximal cuts, we obtain a form of the three-loop
four-point scattering amplitude of N=8 supergravity in which all ultraviolet
cancellations are made manifest. The Feynman loop integrals that appear have a
graphical representation with only cubic vertices, and numerator factors that
are quadratic in the loop momenta, rather than quartic as in the previous form.
This quadratic behavior reflects cancellations beyond those required for
finiteness, and matches the quadratic behavior of the three-loop four-point
scattering amplitude in N=4 super-Yang-Mills theory. By direct integration we
confirm that no additional cancellations remain in the N=8 supergravity
amplitude, thus demonstrating that the critical dimension in which the first
ultraviolet divergence occurs at three loops is D_c=6. We also give the values
of the three-loop divergences in D=7,9,11. In addition, we present the
explicitly color-dressed three-loop four-point amplitude of N=4
super-Yang-Mills theory.


title: Complex Organic Materials in the HR 4796A Disk?

abstract:
  The red spectral shape of the visible to near infrared reflectance spectrum
of the sharply-edged ring-like disk around the young main sequence star HR
4796A was recently interpreted as the presence of tholin-like complex organic
materials which are seen in the atmosphere and surface of Titan and the
surfaces of icy bodies in the solar system. However, we show in this Letter
that porous grains comprised of common cosmic dust species (amorphous silicate,
amorphous carbon, and water ice) also closely reproduce the observed
reflectance spectrum, suggesting that the presence of complex organic materials
in the HR 4796 disk is still not definitive.


title: Length Four Polynomial Automorphisms

abstract:
  We study the structure of length four polynomial automorphisms of $R[X,Y]$
when $R$ is a UFD. The results from this study are used to prove that if
$\text{SL}_m(R[X_1,X_2,..., X_n]) = \text{E}_m(R[X_1,X_2,..., X_n])$ for all
$n, m \ge 0$ then all length four polynomial automorphisms of $R[X,Y]$ that are
conjugates are stably tame.


title: On Dust Extinction of Gamma-ray Burst Host Galaxies

abstract:
  Although it is well recognized that gamma-ray burst (GRB) afterglows are
obscured and reddened by dust in their host galaxies, the wavelength-dependence
and quantity of dust extinction are still poorly known. Current studies on this
mostly rely on fitting the afterglow spectral energy distributions (SEDs) with
template extinction models. The inferred extinction (both quantity and
wavelength-dependence) and dust-to-gas ratios are often in disagreement with
that obtained from dust depletion and X-ray spectroscopy studies. We argue that
this discrepancy could result from the prior assumption of a template
extinction law. We propose an analytical formula to approximate the GRB host
extinction law. With the template extinction laws self-contained, and the
capability of revealing extinction laws differing from the conventional ones,
it is shown that this is a powerful approach in modeling the afterglow SEDs to
derive GRB host extinction.


title: Evolution of a vacuum shell in the Friedman-Schwarzschild world

abstract:
  The method of an effective potential is used to investigate the possible
types of evolution of vacuum shells in the Friedman-Schwarzschild world. Such
shells are assumed to emerge during phase transitions in the early Universe.
The possible global geometries are constructed for the Friedman- Schwarzschild
worlds. Approximate solutions to the equation of motion of a vacuum shell have
been found. The conditions under which the end result of the evolution of the
vacuum shells under consideration is the formation of black holes and wormholes
with baby universes inside have been found. The interior of this world can be a
closed, flat, or open Friedman universe.


title: Dust in Active Galactic Nuclei

abstract:
  Dust plays an essential role in the unification theory of active galactic
nuclei (AGNs). This review summarizes our current understanding of the
extinction and infrared emission properties of the circumnuclear dust in AGNs
as well as the inferred dust composition and size distribution.


title:
Asymptotic behavior of the smallest eigenvalue of matrices associated
  with completely even functions (mod r)

abstract:
  In this paper we present systematically analysis on the smallest eigenvalue
of matrices associated with completely even functions (mod $r$). We obtain
several theorems on the asymptotic behavior of the smallest eigenvalue of
matrices associated with completely even functions (mod $r$). In particular, we
get information on the asymptotic behavior of the smallest eigenvalue of the
famous Smith matrices. Finally some examples are given to demonstrate the main
results.