title:
Integration of iron in natural and synthetic Al-pyrophyllites: an
  infrared spectroscopic study

abstract:
  Numerous studies focus on the relationships between chemical composition and
OHband positions in the infrared (IR) spectra of micaceous minerals. These
studies are based on the coexistence, in dioctahedral micas or smectites, of
several cationic pairs around the hydroxyl group which each produce a
characteristic band in the IR spectrum. The aim of this work is to obtain the
wavenumber values of the IR OH vibration bands of the (Al-Fe3+)-OH and
(Fe3+-Fe3+)-OH local cationic environments of 'pyrophyllite type' in order to
prove, disprove or modify a model of dioctahedral phyllosilicate OH-stretching
band decomposition. Natural samples are characterized by powder X-ray
diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopies
and electron microprobe; the hydrothermal synthesis products are also analysed
by powder XRD and FTIR after inductively coupled plasma measurements to obtain
the chemical compositions of nascent gel phases. Natural samples contain some
impurities which were eliminated after acid treatment; nevertheless, a small Fe
content is found in the pyrophyllite structure. The amount of Fe which is
incorporated within the pyrophyllite structure is much more important for the
synthetic samples than for the natural ones. The IR OH bands were clearly
observed in both natural and synthetic pyrophyllites and assigned to hydroxides
bonded to (Al-Al), (Al-Fe) and (Fe-Fe) cationic pairs. During this study, three
samples were analysed by DTG to check the cis- or trans-vacant character of the
layers and to determine the influence of this structural character on the
OH-stretching band position in IR spectroscopy.


title: A Dipole Vortex Model of Obscuring Tori in Active Galaxy Nuclei

abstract:
  The torus concept as an essential structural component of active galactic
nuclei (AGN) is generally accepted. Here, the situation is discussed when the
torus "twisting" by the radiation or wind transforms it into a dipole toroidal
vortex which in turn can be a source of matter replenishing the accretion disk.
Thus emerging instability which can be responsible for quasar radiation flares
accompanied by matter outbursts is also discussed. The "Matreshka" scheme for
an obscuring vortex torus structure capable of explaining the AGN variability
and evolution is proposed. The model parameters estimated numerically for the
luminosity close to the Eddington limit agree well with the observations.


title: Dark matter in low mass surface density galaxies

abstract:
  Low mass surface density spiral and irregular galaxies like low surface
brightness (LSB) and dwarf galaxies are unique laboratories to study the
dynamical properties of Dark Matter halos because their mass is generally
dominated by dark matter at all galactocentric radii. We present results from
the largest sample ever assembled of high resolution Halpha velocity fields of
LSB and dwarf galaxies in order to study their mass distributions.


title:
IRVO: an Interaction Model for designing Collaborative Mixed Reality
  systems

abstract:
  This paper presents an interaction model adapted to mixed reality
environments known as IRVO (Interacting with Real and Virtual Objects). IRVO
aims at modeling the interaction between one or more users and the Mixed
Reality system by representing explicitly the objects and tools involved and
their relationship. IRVO covers the design phase of the life cycle and models
the intended use of the system. In a first part, we present a brief review of
related HCI models. The second part is devoted to the IRVO model, its notation
and some examples. In the third part, we present how IRVO is used for designing
applications and in particular we show how this model can be integrated in a
Model-Based Approach (CoCSys) which is currently designed at our lab.


title: Measurement of Nuclear Transparency for the A(e,e' pi^+) Reaction

abstract:
  We have measured the nuclear transparency of the A(e,e' pi^+) process in
^{2}H,^{12}C, ^{27}Al, ^{63}Cu and ^{197}Au targets. These measurements were
performed at the Jefferson Laboratory over a four momentum transfer squared
range Q^2 = 1.1 - 4.7 (GeV/c)^2. The nuclear transparency was extracted as the
super-ratio of $(\sigma_A/\sigma_H)$ from data to a model of
pion-electroproduction from nuclei without pi-N final state interactions. The
Q^2 and atomic number dependence of the nuclear transparency both show
deviations from traditional nuclear physics expectations, and are consistent
with calculations that include the quantum chromodynamical phenomenon of color
transparency.


title:
The effect of baryon cooling on the statistics of giant arcs and
  multiple quasars

abstract:
  The statistics of giant arcs and large separation lensed quasars provide
powerful constraints for the parameters of the underlying cosmological model.
So far, most investigations have been carried out using pure dark matter
simulations. Here we present a recipe for including the effects of baryon
cooling (i.e. large galaxy formation) in dark matter N-body simulations that is
consistent with observations of massive galaxies. Then we quantitatively
compare lensing with and without applying this baryon correction to the pure
dark matter case. Including the baryon correction significantly increases the
frequency of giant arcs and lensed quasars, particularly on scales of 10 arcsec
and smaller: the overall frequency of multiple images increases by about 25%
for source redshifts between z_s = 1.5 and 7.5 and splittings larger than about
3 arcsec. The baryon rearrangement also slightly increases the fraction of
quadruple images over doubles.


title: On the YM and QCD spectra from five dimensional strings

abstract:
  We consider a non-critical five dimensional string setup which could provide
a dual description of QCD in the limit of large number of colors and flavors.
The model corresponds to N_c color D3-branes and N_f D4/anti D4-brane pairs
supporting flavor degrees of freedom. The matching of the string model spectrum
with the dual field theory one is considered. We discuss the consequences of
the possible matching of the gravity modes with the light glueballs and the
interpretation of the brane spectrum in Yang-Mills and QCD.


title: Instability of reconstruction of the low CMB multipoles

abstract:
  We discuss the problem of the bias of the Internal Linear Combination (ILC)
CMB map and show that it is closely related to the coefficient of
cross-correlation K(l) of the true CMB and the foreground for each multipole l.
We present analysis of the cross-correlation for the WMAP ILC quadrupole and
octupole from the first (ILC(I)) and the third (ILC(III)) year data releases
and show that these correlations are about -0.52-0.6. Analysing 10^4 Monte
Carlo simulations of the random Gaussian CMB signals, we show that the
distribution function for the corresponding coefficient of the
cross-correlation has a polynomial shape P(K,l)\propto(1-K^2)^(l-1). We show
that the most probable value of the cross-correlation coefficient of the ILC
and foreground quadrupole has two extrema at K ~= +/-0.58$. Thus, the ILC(III)
quadrupole represents the most probable value of the coefficient K. We analyze
the problem of debiasing of the ILC CMB and pointed out that reconstruction of
the bias seems to be very problematic due to statistical uncertainties. In
addition, instability of the debiasing illuminates itself for the quadrupole
and octupole components through the flip-effect, when the even (l+m) modes can
be reconstructed with significant error. This error manifests itself as
opposite, in respect to the true sign of even low multipole modes, and leads to
significant changes of the coefficient of cross-correlation with the
foreground. We show that the CMB realizations, whose the sign of quadrupole
(2,0) component is negative (and the same, as for all the foregrounds), the
corresponding probability to get the positive sign after implementation of the
ILC method is about 40%.


title: Descent on Elliptic Curves and Hilbert's Tenth Problem

abstract:
  Descent via an isogeny on an elliptic curve is used to construct two subrings
of the field of rational numbers, which are complementary in a strong sense,
and for which Hilbert's Tenth Problem is undecidable. This method further
develops that of Poonen, who used elliptic divisibility sequences to obtain
undecidability results for some large subrings of the rational numbers.


title:
The modulus of continuity of Wegner estimates for random Schr\"odinger
  operators on metric graphs

abstract:
  We consider an alloy type potential on an infinite metric graph. We assume a
covering condition on the single site potentials. For random Schr\"odingers
operator associated with the alloy type potential restricted to finite volume
subgraphs we prove a Wegner estimate which reproduces the modulus of continuity
of the single site distribution measure. The Wegner constant is independent of
the energy.


title:
Traversable wormholes: minimum violation of null energy condition
  revisited

abstract:
  It was argued in literature that traversable wormholes can exist with
arbitrarily small violation of null energy conditions. We show that if the
amount of exotic material near the wormhole throat tends to zero, either this
leads to a horn instead of a wormhole or the throat approaches the horizon in
such a way that infnitely large stresses develop on the throat.


title: First Results from the DRIFT-IIa Dark Matter Detector

abstract:
  Data from the DRIFT-IIa directional dark matter experiment are presented,
collected during a near continuous 6 month running period. A detailed
calibration analysis comparing data from gamma-ray, x-ray and neutron sources
to a GEANT4 Monte Carlo simulations reveals an efficiency for detection of
neutron induced recoils of 94+/-2(stat.)+/-5(sys.)%. Software-based cuts,
designed to remove non-nuclear recoil events, are shown to reject 60Co
gamma-rays with a rejection factor of better than 8x10-6 for all energies above
threshold. An unexpected event population has been discovered and is shown here
to be due to the alpha-decay of 222Rn daughter nuclei that have attached to the
central cathode. A limit on the flux of neutrons in the Boulby Underground
Laboratory is derived from analysis of unshielded and shielded data.


title: Is there an eta-3He quasi--bound state ?

abstract:
  The observed variation of the total cross section for the dp -> 3He eta
reaction near threshold means that the magnitude of the s--wave amplitude falls
very rapidly with the eta centre--of--mass momentum. It is shown here that
recent measurements of the momentum dependence of the angular distribution
imply a strong variation also in the phase of this amplitude. Such a behaviour
is that expected from a quasi--bound or virtual eta-3He state. The
interpretation can be investigated further through measurements of the deuteron
or proton analysing powers and/or spin--correlations.


title:
Fast computing of velocity field for flows in industrial burners and
  pumps

abstract:
  In this work we present a technique of fast numerical computation for
solutions of Navier-Stokes equations in the case of flows of industrial
interest. At first the partial differential equations are translated into a set
of nonlinear ordinary differential equations using the geometrical shape of the
domain where the flow is developing, then these ODEs are numerically resolved
using a set of computations distributed among the available processors. We
present some results from simulations on a parallel hardware architecture using
native multithreads software and simulating a shared-memory or a
distributed-memory environment.


title: Secondary Baryon Asymmetry in pi(+-)p Collisions

abstract:
  The process of secondary baryon production in pi(+-)p collisions at high
energies in the central and forward fragmentation regions is considered in the
framework of the Quark-Gluon String Model. The contribution of the
string-junction mechanism to the baryon production is analysed. The results of
numerical calculations are in reasonable agreement with the experimental data
on the Lambda/bar(Lambda) and p/bar(p)$ asymmetries.


title:
Electronic structure of heavily-doped graphene: the role of foreign atom
  states

abstract:
  Using density functional theory calculations we investigate the electronic
structure of graphene doped by deposition of foreign atoms. We demonstrate
that, as the charge transfer to the graphene layer increases, the band
structure of the pristine graphene sheet is substantially affected. This is
particularly relevant when Ca atoms are deposed on graphene at CaC$_{6}$
stoichiometry. Similarly to what happens in superconducting graphite
intercalated compounds, a Ca bands occurs at the Fermi level. Its hybridization
with the C states generates a strong non-linearity in one of the $\pi^{*}$
bands below the Fermi level, at energies comparable to the graphene E$_{2g}$
phonon frequency. This strong non-linearity, and not manybody effects as
previously proposed, explains the large and anisotropic values of the apparent
electron-phonon coupling measured in angular resolved photoemission.


title:
The Role of Exploding QSOs in Explosive Models of Evolution, Formation
  and End of Galaxies

abstract:
  In this work we analise the role and evidence of exploding BAL + IR + Fe II
QSOs, and their relation with new -and previous- explosive models for
evolution, formation and end of galaxies.


title: Heisenberg Uncertainty Principle for the q-Bessel Fourier transform

abstract:
  In this paper we uses an I.I. Hirschman-W. Beckner entropy argument to give
an uncertainty inequality for the $q$-Bessel Fourier transform: $$
\mathcal{F}_{q,v}f(x)=c_{q,v}\int_{0}^{\infty}f(t)j_{v}(xt,q^{2})t^{2v
+1}d_{q}t, $$ where $j_v(x,q)$ is the normalized Hahn-Exton $q$-Bessel
function.


title: Sterile neutrinos as subdominant warm dark matter

abstract:
  In light of recent findings which seem to disfavor a scenario with (warm)
dark matter entirely constituted of sterile neutrinos produced via the
Dodelson-Widrow (DW) mechanism, we investigate the constraints attainable for
this mechanism by relaxing the usual hypothesis that the relic neutrino
abundance must necessarily account for all of the dark matter. We first study
how to reinterpret the limits attainable from X-ray non-detection and
Lyman-alpha forest measurements in the case that sterile neutrinos constitute
only a fraction fs of the total amount of dark matter. Then, assuming that
sterile neutrinos are generated in the early universe solely through the DW
mechanism, we show how the X-ray and Lyman-alpha results jointly constrain the
mass-mixing parameters governing their production. Furthermore, we show how the
same data allow us to set a robust upper limit fs < 0.7 at the 2 sigma level,
rejecting the case of dominant dark matter (fs = 1) at the ~ 3 sigma level.


title:
Subsets of F_p^n without three term arithmetic progressions have several
  large Fourier coefficients

abstract:
  Suppose that f : F_p^n -> [0,1] has expected value t in [p^(-n/9),1] (so, the
density t can be quite low!). Furthermore, suppose that support(f) has no
three-term arithmetic progressions. Then, we develop non-trivial lower bounds
for f_j, which is the jth largest Fourier coefficient of f.
  This result is similar in spirit to that appearing in an earlier paper [1] by
the author; however, in that paper the focus was on the ``small'' Fourier
coefficients, whereas here the focus is on the ``large'' Fourier coefficients.
Furthermore, the proof in the present paper requires much more sophisticated
arguments than those of that other paper.


title:
Polaritonic characteristics of insulator and superfluid phases in a
  coupled-cavity array

abstract:
  Recent studies of quantum phase transitions in coupled atom-cavity arrays
have focused on the similarities between such systems and the Bose-Hubbard
model. However, the bipartite nature of the atom-cavity systems that make up
the array introduces some differences. In order to examine the unique features
of the coupled-cavity system, the behavior of a simple two-site model is
studied over a wide range of parameters. Four regions are identified, in which
the ground state of the system may be classified as either a polaritonic
insulator, a photonic superfluid, an atomic insulator, or a polaritonic
superfluid.


title:
Hysteresis and re-entrant melting of a self-organized system of
  classical particles confined in a parabolic trap

abstract:
  A self-organized system composed of classical particles confined in a
two-dimensional parabolic trap and interacting through a potential with a
short-range attractive part and long-range repulsive part is studied as
function of temperature. The influence of the competition between the
short-range attractive part of the inter-particle potential and its long-range
repulsive part on the melting temperature is studied. Different behaviors of
the melting temperature are found depending on the screening length ($\kappa$)
and the strength ($B$) of the attractive part of the inter-particle potential.
A re-entrant behavior and a thermal induced phase transition is observed in a
small region of ($\kappa,B$)-space. A structural hysteresis effect is observed
as a function of temperature and physically understood as due to the presence
of a potential barrier between different configurations of the system.


title: Polarization anisotropy in the optical properties of silicon ellipsoids

abstract:
  A new real space quantum mechanical approach with local field effects
included is applied to the calculation of the optical properties of silicon
nanocrystals. Silicon ellipsoids are studied and the role of surface
polarization is discussed in details. In particular, surface polarization is
shown to be responsible for a strong optical anisotropy in silicon ellipsoids,
much more pronounced with respect to the case in which only quantum confinement
effects are considered. The static dielectric constant and the absorption
spectra are calculated, showing that the perpendicular and parallel components
have a very different dependence on the ellipsoid aspect ratio. Then, a
comparison with the classical dielectric model is performed, showing that the
model only works for large and regular structures, but it fails for thin
elongated ellipsoids.


title: On the Correlation of Subevents in the ATLAS and CMS/Totem Experiments

abstract:
  We analyze the problem of correlating pp interaction data from the central
detectors with a subevent measured in an independent system of leading proton
detectors using FP420 as an example.
  FP420 is an R&D project conducted by a collaboration formed by members of
ATLAS and CMS to investigate the possibility of detecting new physics in the
central exclusive channel, PP -> P + X + P,where the central system X may be a
single particle, for example a Standard Model Higgs boson. With standard LHC
optics, the protons emerge from the beam at a distance of 420m from the
Interaction Point, for M_X ~ 120 GeV. The mass of the central system can be
measured from the outgoing protons alone, with a resolution of order 2 GeV
irrespective of the decay products of the central system. In addition, to a
very good approximation, only central systems with 0^++ quantum numbers can be
produced, meaning that observation of a SM or MSSM Higgs Boson in this channel
would lead to a direct determination of the quantum numbers.


title: Random subgroups and analysis of the length-based and quotient attacks

abstract:
  In this paper we discuss generic properties of "random subgroups" of a given
group G. It turns out that in many groups G (even in most exotic of them) the
random subgroups have a simple algebraic structure and they "sit" inside G in a
very particular way. This gives a strong mathematical foundation for
cryptanalysis of several group-based cryptosystems and indicates on how to
chose "strong keys". To illustrate our technique we analyze the
Anshel-Anshel-Goldfeld (AAG) cryptosystem and give a mathematical explanation
of recent success of some heuristic length-based attacks on it. Furthermore, we
design and analyze a new type of attacks, which we term the quotient attacks.
Mathematical methods we develop here also indicate how one can try to choose
"parameters" in AAG to foil the attacks.


title: Quasi-isometries Between Tubular Groups

abstract:
  We give a method of constructing maps between tubular groups inductively
according to a set of strategies. This map will be a quasi-isometry exactly
when the set of strategies is consistent. Conversely, if there exists a
quasi-isometry between tubular groups, then there is a consistent set of
strategies for them.
  There is an algorithm that will in finite time either produce a consistent
set of strategies or decide that such a set does not exist. Consequently, this
algorithm decides whether or not the groups are quasi-isometric.


title: ProbCD: enrichment analysis accounting for categorization uncertainty

abstract:
  As in many other areas of science, systems biology makes extensive use of
statistical association and significance estimates in contingency tables, a
type of categorical data analysis known in this field as enrichment (also
over-representation or enhancement) analysis. In spite of efforts to create
probabilistic annotations, especially in the Gene Ontology context, or to deal
with uncertainty in high throughput-based datasets, current enrichment methods
largely ignore this probabilistic information since they are mainly based on
variants of the Fisher Exact Test. We developed an open-source R package to
deal with probabilistic categorical data analysis, ProbCD, that does not
require a static contingency table. The contingency table for the enrichment
problem is built using the expectation of a Bernoulli Scheme stochastic process
given the categorization probabilities. An on-line interface was created to
allow usage by non-programmers and is available at:
http://xerad.systemsbiology.net/ProbCD/ . We present an analysis framework and
software tools to address the issue of uncertainty in categorical data
analysis. In particular, concerning the enrichment analysis, ProbCD can
accommodate: (i) the stochastic nature of the high-throughput experimental
techniques and (ii) probabilistic gene annotation.


title: Perfect Fluidity in Atomic Physics

abstract:
  Experimental results obtained at the Relativistic Heavy Ion Collider (RHIC)
have been interpreted in terms of a strongly interacting quark gluon plasma.
The strongly interacting plasma is characterized by ``perfect fluidity'', i.e.
a ratio of shear viscosity to entropy density that saturates a proposed lower
bound. In this contribution we explore the possibility that a similar
phenomenon takes place in a strongly coupled non-relativistic Fermi liquid in
which the scattering length between the Fermions is infinitely large.


title: Variation of Periods Modulo p in Arithmetic Dynamics

abstract:
  Let F : V --> V be a self-morphism of a quasiprojective variety defined over
a number field K and let P be a point in V(K) with infinite orbit under
iteration of F. For each prime ideal p of good reduction, let m_p(F,P) be the
size of the F-orbit of the reduction of P modulo p. Fix any e > 0. We show that
for almost all primes p, in the sense of analytic density, the orbit size
m_p(F,P) is larger than (log(N(p)))^(1-e), where N(p) is the norm of the ideal
p.


title:
Global Analysis of Fragmentation Functions for Protons and Charged
  Hadrons

abstract:
  We present new sets of fragmentation functions for protons and inclusive
charged hadrons obtained in combined NLO QCD analyses of single-inclusive
hadron production in electron-positron annihilation, proton-proton collisions,
and deep-inelastic lepton-proton scattering. These analyses complement previous
results for pion and kaon fragmentation functions with charge and flavor
discrimination. The Lagrange multiplier technique is used to assess the
uncertainties in the extraction of the new sets of fragmentation functions.


title: Diffractive Neutral Pion Production, Chiral Symmetry and the Odderon

abstract:
  We discuss the diffractive photo- and electroproduction of a single neutral
pion at high energies where it can occur due to odderon exchange. We show that
this process is dynamically suppressed as a consequence of chiral symmetry. Our
result reconciles earlier theoretical expectations with the non-observation of
this reaction at HERA.


title:
How important are next-to-leading order models in predicting strange
  particle spectra in p+p collisions at STAR ?

abstract:
  STAR has measured a variety of strange particle species in p + p collisions
at $\sqrt{s}$ = 200 GeV. These high statistics data are ideal for comparing to
existing leading- and next-to-leading order perturbative QCD (pQCD) models.
Next-to-leading (NLO) models have been successful in describing inclusive
hadron production using parameterized fragmentation functions (FF) for quarks
and gluons. However, in order to describe identied strange particle spectra at
NLO, knowledge of flavor separated FF is essential. Such FF have recently been
parameterized using data by the OPAL experiment and allow for the first time to
perform NLO calculation for strange baryons. In fact, comparing the STAR Lambda
data with these calculations allow to put a constraint on the gluon
fragmentation function. We show that the Leading-order (LO) event generator
PYTHIA has to be tuned significantly to reproduce the STAR identified strange
particle data. In particular, it fails to describe the observed enhancement of
baryon-to-meson ratio at intermediate pT (2-6 GeV/c). In heavy-ion (HI)
collisions this observable has been extensively compared with models and shows
a strong dependency on collision centrality or parton density. In the HI
context the observed enhancement has been explained by recent approaches in
terms of parton coalescense and recombination models.


title: Bs Properties at the Tevatron

abstract:
  Results on Bs properties obtained by the CDF and D0 collaborations using the
data samples collected at the Tevatron Collider in the period 2002-2006 were
presented at the Hadron Collider Physics Symposium 2006 (Duke University,
Durham). The measurements of Bs mass and width differences are discussed in
details.
  Prospects on measurements of CP violation in Bs system are given.


title:
STAR identifed particle measurements at high transverse momentum in p+p
  $\sqrt{s}$ = 200 GeV

abstract:
  We present the STAR measurement of transverse momentum spectra at
mid-rapidity for identified particles in p+p collisions at $\sqrt{s}$ = 200
GeV. These high statistics data are ideal for comparing to existing leading-
and next-to-leading order (NLO) perturbative QCD calculations. Next-to-leading
models have been successful in describing inclusive hadron production using
parameterized fragmentation functions (FF) for quarks and gluons. However, in
order to describe baryon spectra at NLO, knowledge of flavor separated FF is
essential. Such FF have recently been parameterized using data by the OPAL
experiment and allow for the first time to obtain good agreement between NLO
and identified baryons from p+p collisions.


title:
Distilling entanglement from cascades with partial "Which Path"
  ambiguity

abstract:
  We develop a framework to calculate the density matrix of a pair of photons
emitted in a decay cascade with partial "which path" ambiguity. We describe an
appropriate entanglement distillation scheme which works also for certain
random cascades. The qualitative features of the distilled entanglement are
presented in a two dimensional "phase diagram". The theory is applied to the
quantum tomography of the decay cascade of a biexciton in a semiconductor
quantum dot. Agreement with experiment is obtained.


title: Mirror Duality in a Joyce Manifold

abstract:
  Previously the two of the authors defined a notion of dual Calabi-Yau
manifolds in a G_2 manifold, and described a process to obtain them. Here we
apply this process to a compact G_2 manifold, constructed by Joyce, and as a
result we obtain a pair of Borcea-Voisin Calabi-Yau manifolds, which are known
to be mirror duals of each other.


title: Group velocity of gravitational waves in an expanding universe

abstract:
  The group velocity of gravitational waves in a flat Friedman-Robertson-Walker
universe is investigated. For plane waves with wavelength well inside the
horizon, and a universe filled with an ideal fluid with the pressure to density
ratio less than 1/3, the group velocity is greater than the velocity of light.
As a result, a planar pulse of gravitational waves propagating through the
universe during the matter/dark energy dominated era arrives to the observer
with the peak shifted towards the forefront. For gravitational waves emitted by
inspiralling supermassive black holes at the edge of the observable universe,
the typical shift that remains after the effects of nonplanarity are suppressed
is of order of ten picoseconds.


title:
Effect of Two Level System Saturation on Charge Noise in Josephson
  Junction Qubits

abstract:
  We show that charge noise $S_Q$ in Josephson qubits can be produced by
fluctuating two level systems (TLS) with electric dipole moments in the
substrate using a flat density of states. At high frequencies the frequency and
temperature dependence of the charge noise depends on the ratio $J/J_c$ of the
electromagnetic flux $J$ to the critical flux $J_c$. It is not widely
appreciated that TLS in small qubits can easily be strongly saturated with
$J/J_c\gg 1$. Our results are consistent with experimental conclusions that
$S_Q\sim 1/f$ at low frequencies and $S_Q\sim f$ at high frequencies.


title:
Properties of polynomial bases used in a line-surface intersection
  algorithm

abstract:
  In [5], Srijuntongsiri and Vavasis propose the "Kantorovich-Test Subdivision
algorithm", or KTS, which is an algorithm for finding all zeros of a polynomial
system in a bounded region of the plane. This algorithm can be used to find the
intersections between a line and a surface. The main features of KTS are that
it can operate on polynomials represented in any basis that satisfies certain
conditions and that its efficiency has an upper bound that depends only on the
conditioning of the problem and the choice of the basis representing the
polynomial system.
  This article explores in detail the dependence of the efficiency of the KTS
algorithm on the choice of basis. Three bases are considered: the power, the
Bernstein, and the Chebyshev bases. These three bases satisfy the basis
properties required by KTS. Theoretically, Chebyshev case has the smallest
upper bound on its running time. The computational results, however, do not
show that Chebyshev case performs better than the other two.


title:
Benchmark calculations for 3H, 4He, 16O and 40Ca with ab-initio
  coupled-cluster theory

abstract:
  We present ab-initio calculations for 3H, 4He, 16O, and 40Ca based on
two-nucleon low-momentum interactions Vlowk within coupled-cluster theory. For
3H and 4He, our results are within 70 keV and 10 keV of the corresponding
Faddeev and Faddeev-Yakubovsky energies. We study in detail the convergence
with respect to the size of the model space and the single-particle basis. For
the heavier nuclei, we report practically converged binding energies and
compare with other approaches.


title: Environmental dependence of AGN activity in the supercluster A901/2

abstract:
  We present XMM data for the supercluster A901/2, at z ~ 0.17, which is
combined with deep imaging and 17-band photometric redshifts (from the COMBO-17
survey), 2dF spectra and Spitzer 24um data, to identify AGN in the
supercluster. The 90ksec XMM image contains 139 point sources, of which 11 are
identified as supercluster AGN with L_X(0.5-7.5keV) > 1.7x10^41 erg/cm2/s. The
host galaxies have M_R < -20 and only 2 of 8 sources with spectra could have
been identified as AGN by the detected optical emission lines. Using a large
sample of 795 supercluster galaxies we define control samples of massive
galaxies with no detected AGN. The local environments of the AGN and control
samples differ at >98 per cent significance. The AGN host galaxies lie
predominantly in areas of moderate projected galaxy density and with more local
blue galaxies than the control sample, with the exception of one very bright
Type I AGN very near the centre of a cluster. These environments are similar
to, but not limited to, cluster outskirts and blue groups. Despite the large
number of potential host galaxies, no AGN are found in regions with the highest
galaxy density (excluding some cluster cores where emission from the ICM
obscures moderate luminosity AGN). AGN are also absent from the areas with
lowest galaxy density. We conclude that the prevalence of cluster AGN is linked
to their environment.


title:
Gluino Axion, Neutrino Seesaw, Dynamical Gaugino Mass, and A = 0
  Supersymmetry

abstract:
  In the axionic solution of the strong CP problem, fermions which transform
under quantum chromodynamics (QCD) are required. In supersymmetry, by equating
U(1)_{PQ} with U(1)_R, the natural candidates are the gluinos, as pointed out
some years ago. A new specific implementation of this idea is proposed, linking
the gluino axion scale to that of the canonical seesaw mechanism for neutrinos.
Gaugino masses are generated dynamically and the A term is predicted to be very
small.


title:
Deformation Quantization of Almost Kahler Models and Lagrange-Finsler
  Spaces

abstract:
  Finsler and Lagrange spaces can be equivalently represented as almost Kahler
manifolds enabled with a metric compatible canonical distinguished connection
structure generalizing the Levi Civita connection. The goal of this paper is to
perform a natural Fedosov-type deformation quantization of such geometries. All
constructions are canonically derived for regular Lagrangians and/or
fundamental Finsler functions on tangent bundles.


title: Shear viscosity of a superfluid Fermi gas in the unitarity limit

abstract:
  We compute the shear viscosity of a superfluid atomic Fermi gas in the
unitarity limit. The unitarity limit is characterized by a divergent scattering
length between the atoms, and it has been argued that this will result in a
very small viscosity. We show that in the low temperature T limit the shear
viscosity scales as xi^5/T^5, where the universal parameter 'xi' relates the
chemical potential and the Fermi energy, mu=xi E_F. Combined with the high
temperature expansions of the viscosity our results suggest that the viscosity
has a minimum near the critical temperature T_c. A naive extrapolation
indicates that the minimum value of the ratio of viscosity over entropy density
is within a factor of ~ 5 of the proposed lower bound hbar/(4\pi k_B).


title: Reexamination of entanglement of superpositions

abstract:
  We find tight lower and upper bounds on the entanglement of a superposition
of two bipartite states in terms of the entanglement of the two states
constituting the superposition. Our upper bound is dramatically tighter than
the one presented in Phys. Rev. Lett 97, 100502 (2006) and our lower bound can
be used to provide lower bounds on different measures of entanglement such as
the entanglement of formation and the entanglement of subspaces. We also find
that in the case in which the two states are one-sided orthogonal, the
entanglement of the superposition state can be expressed explicitly in terms of
the entanglement of the two states in the superposition.


title: Superexchange induced canted ferromagnetism in dilute magnets

abstract:
  We argue, in contrast to recent studies, that the antiferromagnetic
superexchange coupling between nearest neighbour spins does not fully destroy
the ferromagnetism in dilute magnets with long-ranged ferromagnetic couplings.
Above a critical coupling, we find a \textit{canted} ferromagnetic phase with
unsaturated moment. We have calculated the transition temperature using a
simplified local Random Phase Approximation procedure which accounts for the
canting. For the dilute magnetic semiconductors, such as GaMnAs, using
\textit{ab-initio} couplings allows us to predict the existence of a canted
phase and provide an explanation to the apparent contradictions observed in
experimental measurements. Finally, we have compared with previous studies that
used RKKY couplings and reported non-ferromagnetic state when the superexchange
is too strong. Even in this case the ferromagnetism should remain essentially
stable in the form of a canted phase.


title:
Ages and Abundances of Red Sequence Galaxies as a Function of LINER
  Emission Line Strength

abstract:
  Although the spectrum of a prototypical early-type galaxy is assumed to lack
emission lines, a substantial fraction (likely as high as 30%) of nearby red
sequence galaxy spectra contain emission lines with line ratios characteristic
of low ionization nuclear emission-line regions (LINERs). We use spectra of
~6000 galaxies from the Sloan Digital Sky Survey (SDSS) in a narrow redshift
slice (0.06 < z < 0.08) to compare the stellar populations of red sequence
galaxies with and without LINER-like emission. The spectra are binned by
internal velocity dispersion and by emission properties to produce high S/N
stacked spectra. The recent stellar population models of R. Schiavon (2007)
make it possible to measure ages, [Fe/H], and individual elemental abundance
ratios [Mg/Fe], [C/Fe], [N/Fe], and [Ca/Fe] for each of the stacked spectra. We
find that red sequence galaxies with strong LINER-like emission are
systematically 2-3.5 Gyr (10-40%) younger than their emission-free counterparts
at the same velocity dispersion. This suggests a connection between the
mechanism powering the emission (whether AGN, post-AGB stars, shocks, or
cooling flows) and more recent star formation in the galaxy. We find that mean
stellar age and [Fe/H] increase with velocity dispersion for all galaxies.
Elemental abundance [Mg/Fe] increases modestly with velocity dispersion in
agreement with previous results, and [C/Fe] and [N/Fe] increase more strongly
with velocity dispersion than does [Mg/Fe]. [Ca/Fe] appears to be roughly solar
for all galaxies. At fixed velocity dispersion, galaxies with fainter r-band
luminosities have lower [Fe/H] and older ages but similar abundance ratios
compared to brighter galaxies.


title:
Finsler-Lagrange Geometries and Standard Theories in Physics: New
  Methods in Einstein and String Gravity

abstract:
  In this article, we review the current status of Finsler-Lagrange geometry
and generalizations. The goal is to aid non-experts on Finsler spaces, but
physicists and geometers skilled in general relativity and particle theories,
to understand the crucial importance of such geometric methods for applications
in modern physics. We also would like to orient mathematicians working in
generalized Finsler and Kahler geometry and geometric mechanics how they could
perform their results in order to be accepted by the community ''orthodox''
physicists. Although the bulk of former models of Finsler-Lagrange spaces where
elaborated on tangent bundles, the surprising result advocated in our works is
that such locally anisotropic structures can be modelled equivalently on
Riemann-Cartan spaces, even as exact solutions in Einstein and/or string
gravity, if nonholonomic distributions and moving frames of references are
introduced into consideration. We also propose a canonical scheme when
geometrical objects on a (pseudo) Riemannian space are nonholonomically
deformed into generalized Lagrange, or Finsler, configurations on the same
manifold or on a corresponding tangent bundle. Such canonical transforms are
defined by the coefficients of a prime metric (it can be a solution of the
Einstein equations) and generate target spaces as generalized Lagrange
structures, their models of almost Hermitian/ Kahler, or nonholonomic Riemann
spaces with constant curvature, for some Finsler like connections. There are
formulated the criteria when such constructions can be redefined equivalently
in terms of the Levi Civita connection.


title:
The patch topology and the ultrafilter topology on the prime spectrum of
  a commutative ring

abstract:
  Let R be a commutative ring and let Spec(R) denote the collection of prime
ideals of R. We define a topology on Spec(R) by using ultrafilters and
demonstrate that this topology is identical to the well known patch or
constructible topology. The proof is accomplished by use of a von Neumann
regular ring canonically associated with $R$.


title:
Generalized Lagrange Transforms: Finsler Geometry Methods and
  Deformation Quantization of Gravity

abstract:
  We propose a natural Fedosov type quantization of generalized Lagrange models
and gravity theories with metrics lifted on tangent bundle, or extended to
higher dimension, following some stated geometric/ physical conditions (for
instance, nonholonomic and/or conformal transforms to some physically important
metrics or mapping into a gauge model). Such generalized Lagrange transforms
define canonical nonlinear connection, metric and linear connection structures
and model almost Kahler geometries with induced canonical symplectic structure
and compatible affine connection. The constructions are possible due to a
synthesis of the nonlinear connection formalism developed in Finsler and
Lagrange geometries and deformation quantization methods.


title: Programming Telepathy: Implementing Quantum Non-Locality Games

abstract:
  Quantum pseudo-telepathy is an intriguing phenomenon which results from the
application of quantum information theory to communication complexity. To
demonstrate this phenomenon researchers in the field of quantum communication
complexity devised a number of quantum non-locality games. The setting of these
games is as follows: the players are separated so that no communication between
them is possible and are given a certain computational task. When the players
have access to a quantum resource called entanglement, they can accomplish the
task: something that is impossible in a classical setting. To an observer who
is unfamiliar with the laws of quantum mechanics it seems that the players
employ some sort of telepathy; that is, they somehow exchange information
without sharing a communication channel. This paper provides a formal framework
for specifying, implementing, and analysing quantum non-locality games.


title: Simplified motional heating rate measurements of trapped ions

abstract:
  We have measured motional heating rates of trapped atomic ions, a factor that
can influence multi-ion quantum logic gate fidelities. Two simplified
techniques were developed for this purpose: one relies on Raman sideband
detection implemented with a single laser source, while the second is even
simpler and is based on time-resolved fluorescence detection during Doppler
recooling. We applied these methods to determine heating rates in a
microfrabricated surface-electrode trap made of gold on fused quartz, which
traps ions 40 microns above its surface. Heating rates obtained from the two
techniques were found to be in reasonable agreement. In addition, the trap
gives rise to a heating rate of 300 plus or minus 30 per second for a motional
frequency of 5.25 MHz, substantially below the trend observed in other traps.


title: Radiation Due to Josephson Oscillations in Layered Superconductors

abstract:
  We derive the power of direct radiation into free space induced by Josephson
oscillations in intrinsic Josephson junctions of highly anisotropic layered
superconductors. We consider the super-radiation regime for a crystal cut in
the form of a thin slice parallel to the c-axis. We find that the radiation
correction to the current-voltage characteristic in this regime depends only on
crystal shape. We show that at large enough number of junctions oscillations
are synchronized providing high radiation power and efficiency in the THz
frequency range. We discuss crystal parameters and bias current optimal for
radiation power and crystal cooling.


title: Pseudospin Magnetism in Graphene

abstract:
  We predict that neutral graphene bilayers are pseudospin magnets in which the
charge density-contribution from each valley and spin spontaneously shifts to
one of the two layers. The band structure of this system is characterized by a
momentum-space vortex which is responsible for unusual competition between band
and kinetic energies leading to symmetry breaking in the vortex core. We
discuss the possibility of realizing a pseudospin version of ferromagnetic
metal spintronics in graphene bilayers based on hysteresis associated with this
broken symmetry.


title:
Spin and orbital magnetic response in metals: susceptibility and NMR
  shifts

abstract:
  A DFT-based method is presented which allows the computation of all-electron
NMR shifts of metallic compounds with periodic boundary conditions. NMR shifts
in metals measure two competing physical phenomena. Electrons interact with the
applied magnetic field (i) as magnetic dipoles (or spins), resulting in the
Knight shift, (ii) as moving electric charges, resulting in the chemical (or
orbital) shift. The latter is treated through an extension to metals of the
Gauge Invariant Projector Augment Wave(GIPAW) developed for insulators. The
former is modeled as the hyperfine interaction between the electronic spin
polarization and the nuclear dipoles. NMR shifts are obtained with respect to
the computed shieldings of reference compounds, yielding fully ab-initio
quantities which are directly comparable to experiment. The method is validated
by comparing the magnetic susceptibility of interacting and non-interacting
homogeneous gas with known analytical results, and by comparing the computed
NMR shifts of simple metals with experiment.


title: Sorting and Selection in Posets

abstract:
  Classical problems of sorting and searching assume an underlying linear
ordering of the objects being compared. In this paper, we study a more general
setting, in which some pairs of objects are incomparable. This generalization
is relevant in applications related to rankings in sports, college admissions,
or conference submissions. It also has potential applications in biology, such
as comparing the evolutionary fitness of different strains of bacteria, or
understanding input-output relations among a set of metabolic reactions or the
causal influences among a set of interacting genes or proteins. Our results
improve and extend results from two decades ago of Faigle and Tur\'{a}n.
  A measure of complexity of a partially ordered set (poset) is its width. Our
algorithms obtain information about a poset by queries that compare two
elements. We present an algorithm that sorts, i.e. completely identifies, a
width w poset of size n and has query complexity O(wn + nlog(n)), which is
within a constant factor of the information-theoretic lower bound. We also show
that a variant of Mergesort has query complexity O(wn(log(n/w))) and total
complexity O((w^2)nlog(n/w)). Faigle and Tur\'{a}n have shown that the sorting
problem has query complexity O(wn(log(n/w))) but did not address its total
complexity.
  For the related problem of determining the minimal elements of a poset, we
give efficient deterministic and randomized algorithms with O(wn) query and
total complexity, along with matching lower bounds for the query complexity up
to a factor of 2. We generalize these results to the k-selection problem of
determining the elements of height at most k. We also derive upper bounds on
the total complexity of some other problems of a similar flavor.


title:
The Fate of Dwarf Galaxies in Clusters and the Origin of Intracluster
  Stars. I. Isolated Clusters

abstract:
  The main goal of this paper is to compare the relative importance of
destruction by tides, vs. destruction by mergers, in order to assess if tidal
destruction of dwarf galaxies in clusters is a viable scenario for explaining
the origin of intracluster stars. We have designed a simple algorithm for
simulating the evolution of isolated clusters. The distribution of galaxies in
the cluster is evolved using a direct gravitational N-body algorithm combined
with a subgrid treatment of physical processes such as mergers, tidal
disruption, and galaxy harassment. Using this algorithm, we have performed a
total of 227 simulations. Our main results are (1) destruction of dwarf
galaxies by mergers dominates over destruction by tides, and (2) the
destruction of dwarf galaxies by tides is sufficient to explain the observed
intracluster light in clusters.


title: An Architecture Framework for Complex Data Warehouses

abstract:
  Nowadays, many decision support applications need to exploit data that are
not only numerical or symbolic, but also multimedia, multistructure,
multisource, multimodal, and/or multiversion. We term such data complex data.
Managing and analyzing complex data involves a lot of different issues
regarding their structure, storage and processing, and metadata are a key
element in all these processes. Such problems have been addressed by classical
data warehousing (i.e., applied to "simple" data). However, data warehousing
approaches need to be adapted for complex data. In this paper, we first propose
a precise, though open, definition of complex data. Then we present a general
architecture framework for warehousing complex data. This architecture heavily
relies on metadata and domain-related knowledge, and rests on the XML language,
which helps storing data, metadata and domain-specific knowledge altogether,
and facilitates communication between the various warehousing processes.


title: Unparticle physics effects in B_s mixing

abstract:
  We investigate unparticle effects in B_s mixing. In particular we discuss the
possibility of reproducing the experimental result of \Delta M_s, while having
large effects on the mixing phase \phi_s, which might be visible in current
experiments.


title: Dark Matter and Particle Physics

abstract:
  [A brief review intended for a general physics colloquium audience.]
Astrophysicists now know that 80% of the matter in the universe is `dark
matter', composed of neutral and weakly interacting elementary particles that
are not part of the Standard Model of particle physics. I will summarize the
evidence for dark matter. I will explain why I expect dark matter particles to
be produced at the CERN LHC. We will then need to characterize the new weakly
interacting particles and demonstrate that they are the same particles that are
found in the cosmos. I will describe how this might be done.


title:
Numerical Modeling of AGN Jets: Formation of Magnetically Dominated
  Lobes and Stability Properties of Current-carrying Jets

abstract:
  We argue the behavior of Poynting flux-dominated outflows from AGN in the
galactic cluster systems by performing three-dimensional MHD simulations within
the framework of the "magnetic tower" model. Of particular interests are the
structure of MHD waves, the cylindrical radial force balance, the
(de)collimation, and the stability properties of magnetic tower jets.
Transition between the jet/lobe and the formation of wiggling jet by growing
current-driven instability are discussed.


title:
Transition temperature of the homogeneous and dilute Bose gas in
  D-dimensions

abstract:
  The phase transition temperature of the homogeneous and dilute Bose gas in
D-dimensions ($2 \le D \le 3$) is calculated by a mean field-based statistical
method. The shift of the phase transition temperature is written up to the
leading order as $\Delta T_c/T_c^0 = c \gam^{\al}$, where $\gam=n^{1/3}a$.
  We derived Huang's result of the phase transition temperature in the
generalized dimensions. We show that $ c(D)$ is positive and
$\al(D)=2(D/2-1)^2$ in the short-wavelength range. The origin of the difference
between $\al=1/2$ and $\al=1$ at D=3 is discussed. The $T_c$ at D=2 is
calculated in the same scheme. The result is compared with Fisher and
Hohenberg's KT temperature.


title: Conjugacy classes and invariant subrings of R-automorphisms of R[x]

abstract:
  We consider the group G of R-automorphisms of the polynomial ring R[x]
especially in the case where R is the ring of integers modulo n. We describe
conjugacy classes in G, and in the case where n = 4, we describe more
explicitly the structure of G and determine all rings of invariants of R[x]
with respect to subgroups of G.


title:
Two-Frequency Radiative Transfer. II: Maxwell Equations in Random
  Dielectrics

abstract:
  The paper addresses the space-frequency correlations of electromagnetic waves
in general random, bi-anisotropic media whose constitutive tensors are complex
Hermitian matrices. The two-frequency Wigner distribution (2f-WD) for polarized
waves is introduced to describe the space-frequency correlations and the closed
form Wigner-Moyal equation is derived from the Maxwell equations. Two-frequency
radiative transfer (2f-RT) equations is then derived from the Wigner-Moyal
equation by using the multiple scale expansion. For the simplest isotropic
medium, the result coincides with Chandrasekhar's transfer equation. In
birefringent media, the 2f-RT equations take the scalar form due to the absence
of depolarization. A number of birefringent media such as the chiral, uniaxial
and gyrotropic media are examined. For the unpolarized wave in the isotropic
medium the 2f-RT equations reduces to the Fokker-Planck equation previously
derived in Part I. A similar Fokker-Planck equation is derived from the scalar
2f-RT equation for the birefringent media.


title: Why we should teach the Bohr model and how to teach it effectively

abstract:
  Some education researchers have claimed that we should not teach the Bohr
model of the atom because it inhibits students' ability to learn the true
quantum nature of electrons in atoms. Although the evidence for this claim is
weak, many have accepted it. This claim has implications for how to present
atoms in classes ranging from elementary school to graduate school. We present
results from a study designed to test this claim by developing a curriculum on
models of the atom, including the Bohr and Schrodinger models. We examine
student descriptions of atoms on final exams in transformed modern physics
classes using various versions of this curriculum. We find that if the
curriculum does not include sufficient connections between different models,
many students still have a Bohr-like view of atoms, rather than a more accurate
Schrodinger model. However, with an improved curriculum designed to develop
model-building skills and with better integration between different models, it
is possible to get most students to describe atoms using the Schrodinger model.
In comparing our results with previous research, we find that comparing and
contrasting different models is a key feature of a curriculum that helps
students move beyond the Bohr model and adopt Schrodinger's view of the atom.
We find that understanding the reasons for the development of models is much
more difficult for students than understanding the features of the models. We
also present interactive computer simulations designed to help students build
models of the atom more effectively.


title: Noncommutative geometry through monoidal categories I

abstract:
  After introducing a noncommutative counterpart of commutative algebraic
geometry based on monoidal categories of quasi-coherent sheaves we show that
various constructions in noncommutative geometry (e.g. Morita equivalences,
Hopf-Galois extensions) can be given geometric meaning extending their
geometric interpretations in the commutative case. On the other hand, we show
that some constructions in commutative geometry (e.g. faithfully flat descent
theory, principal fibrations, equivariant and infinitesimal geometry) can be
interpreted as noncommutative geometric constructions applied to commutative
objects. For such generalized geometry we define global invariants constructing
cyclic objects from which we derive Hochschild, cyclic and periodic cyclic
homology (with coefficients) in the standard way.


title: A New Experiment to Study Hyperon CP Violation and the Charmonium System

abstract:
  Fermilab operates the world's most intense antiproton source, now exclusively
dedicated to serving the needs of the Tevatron Collider. The anticipated 2009
shutdown of the Tevatron presents the opportunity for a world-leading low- and
medium-energy antiproton program. We summarize the status of the Fermilab
antiproton facility and review physics topics for which a future experiment
could make the world's best measurements.


title: Quintessential Kination and Leptogenesis

abstract:
  Thermal leptogenesis induced by the CP-violating decay of a right-handed
neutrino (RHN) is discussed in the background of quintessential kination, i.e.,
in a cosmological model where the energy density of the early Universe is
assumed to be dominated by the kinetic term of a quintessence field during some
epoch of its evolution. This assumption may lead to very different
observational consequences compared to the case of a standard cosmology where
the energy density of the Universe is dominated by radiation. We show that,
depending on the choice of the temperature T_r above which kination dominates
over radiation, any situation between the strong and the super--weak wash--out
regime are equally viable for leptogenesis, even with the RHN Yukawa coupling
fixed to provide the observed atmospheric neutrino mass scale ~ 0.05 eV. For M<
T_r < M/100, i.e., when kination stops to dominate at a time which is not much
later than when leptogenesis takes place, the efficiency of the process,
defined as the ratio between the produced lepton asymmetry and the amount of CP
violation in the RHN decay, can be larger than in the standard scenario of
radiation domination. This possibility is limited to the case when the neutrino
mass scale is larger than about 0.01 eV. The super--weak wash--out regime is
obtained for T_r << M/100, and includes the case when T_r is close to the
nucleosynthesis temperature ~ 1 MeV. Irrespective of T_r, we always find a
sufficient window above the electroweak temperature T ~ 100 GeV for the
sphaleron transition to thermalize, so that the lepton asymmetry can always be
converted to the observed baryon asymmetry.


title:
Dynamics in Nonlocal Cosmological Models Derived from String Field
  Theory

abstract:
  A general class of nonlocal cosmological models is considered. A new method
for solving nonlocal Friedmann equations is proposed, and solutions of the
Friedmann equations with nonlocal operator are presented. The cosmological
properties of these solutions are discussed. Especially indicated is $p$-adic
cosmological model in which we have obtained nonsingular bouncing solution and
string field theory tachyon model in which we have obtained full solution of
nonlocal Friedmann equations with $w=-1$ at large times. The possibility of
obtaining realistic value of cosmological constant from nonlocal cosmological
models is also discussed.


title: Producing an Intense, Cool Muon Beam via e+e- Annihilation

abstract:
  We consider a highly unconventional approach to generating muon and antimuon
bunches for a neutrino factory or muon collider: electron-positron annihilation
just above muon-antimuon threshold. This approach can produce low-emittance
bunches at high energy, easing the muon-cooling and acceleration challenges in
such facilities. However, the small (< 1 $\mu$b) useable production cross
section means that extraordinary beam-power and targeting challenges would have
to be met. We speculate on what this might entail.


title:
The Next Geminga: Search for Radio and X-ray Pulsations from the Neutron
  Star Identified with 3EG J1835+5918

abstract:
  We report unsuccessful searches for pulsations from the neutron star RX
J1836.2+5925 identified with the EGRET source 3EG J1835+5918. A 24 hr
observation with the NRAO Green Bank Telescope at 820 MHz placed an upper limit
on flux density of 17 uJy for P > 10 ms, and gradually increasing limits for 1
< P < 10 ms. The equivalent luminosity is lower than that of any known pulsar
with the possible exception of the radio-quiet gamma-ray pulsar Geminga. A set
of observations with the Chandra X-ray Observatory HRC totaling 118 ks revealed
no pulsar with 1 ms < P < 10 s. The upper limit on its pulsed fraction is 35%
assuming a sinusoidal pulse shape. The position of RX J1836.2+5925 in Chandra
observations separated by 3 years is unchanged within errors, leading to an
upper limit on its proper motion of <0.14"/yr, or v < 530 km/s at d = 800 pc, a
maximum distance estimated from its thermal X-ray spectrum. With these null
results, the properties of 3EG J1835+5918 and its X-ray counterpart RX
J1836.2+5925 are consistent with a more distant or older version of Geminga, or
perhaps a recycled pulsar. Having nearly exhausted the capabilities of current
instrumentation at all wavelengths, it will likely fall to the Gamma-ray Large
Area Space Telescope to discover pulsations from 3EG J1835+5918.


title:
Data Mining-based Materialized View and Index Selection in Data
  Warehouses

abstract:
  Materialized views and indexes are physical structures for accelerating data
access that are casually used in data warehouses. However, these data
structures generate some maintenance overhead. They also share the same storage
space. Most existing studies about materialized view and index selection
consider these structures separately. In this paper, we adopt the opposite
stance and couple materialized view and index selection to take view-index
interactions into account and achieve efficient storage space sharing.
Candidate materialized views and indexes are selected through a data mining
process. We also exploit cost models that evaluate the respective benefit of
indexing and view materialization, and help select a relevant configuration of
indexes and materialized views among the candidates. Experimental results show
that our strategy performs better than an independent selection of materialized
views and indexes.


title:
Fermi arcs in cuprate superconductors: tracking the pseudogap below Tc
  and above T*

abstract:
  Using an energy-momentum dispersion for Bi2Sr2CaCu2O8 obtained from
angle-resolved photoelectron spectroscopy we show that the shrinking Fermi arc
model of the pseudogap is inconsistent with Raman scattering below Tc and
specific heat near T*. By simulating the quasiparticle energy dispersion curves
we show that Fermi arcs are an artifact of a T-dependent scattering rate.


title:
Search for Single Top Quark Production Using Likelihood Discriminants at
  D0 in Run II

abstract:
  We present an improved search for single top quarks in two production modes,
s-channel (tb) and t-channel (tqb). The search is performed in the
electron+jets and muon+jets decay channels, with one or more b-tagged jets, on
nearly 370 pb^{-1} of D0 Run II data collected between August 2002 and October
2004. Impact-parameter based b-quark tagging is used to select signal-like
events. We use a likelihood discriminant method to separate signals from
backgrounds. The resulting expected/observed 95% confidence level upper limits
on the single top quark production cross sections are 3.3/5.0pb (s-channel) and
4.3/4.4pb (t-channel).


title:
Regulatory Dynamics on Random Networks: Asymptotic Periodicity and
  Modularity

abstract:
  We study the dynamics of discrete-time regulatory networks on random
digraphs. For this we define ensembles of deterministic orbits of random
regulatory networks, and introduce some statistical indicators related to the
long-term dynamics of the system. We prove that, in a random regulatory
network, initial conditions converge almost surely to a periodic attractor. We
study the subnetworks, which we call modules, where the periodic asymptotic
oscillations are concentrated. We proof that those modules are dynamically
equivalent to independent regulatory networks.


title: Polynomials with a common composite

abstract:
  Let f and g be nonconstant polynomials over an arbitrary field K. In this
paper we study the intersection of the polynomial rings K[f] and K[g], and in
particular we ask whether this intersection is larger than K. We completely
resolve this question when K has characteristic zero, and in positive
characteristic we present various results, examples, and algorithms.


title: Nonlinear Dirac Equations

abstract:
  We construct nonlinear extensions of Dirac's relativistic electron equation
that preserve its other desirable properties such as locality, separability,
conservation of probability and Poincar\'e invariance. We determine the
constraints that the nonlinear term must obey and classify the resultant
non-polynomial nonlinearities in a double expansion in the degree of
nonlinearity and number of derivatives. We give explicit examples of such
nonlinear equations, studying their discrete symmetries and other properties.
Motivated by some previously suggested applications we then consider nonlinear
terms that simultaneously violate Lorentz covariance and again study various
explicit examples. We contrast our equations and construction procedure with
others in the literature and also show that our equations are not gauge
equivalent to the linear Dirac equation. Finally we outline various physical
applications for these equations.


title: Exact Integration of the High Energy Scale in Doped Mott Insulators

abstract:
  We expand on our earlier work (cond-mat/0612130, Phys. Rev. Lett. {\bf 99},
46404 (2007)) in which we constructed the exact low-energy theory of a doped
Mott insulator by explicitly integrating (rather than projecting) out the
degrees of freedom far away from the chemical potential. The exact low-energy
theory contains degrees of freedom that cannot be obtained from projective
schemes. In particular a new charge $\pm 2e$ bosonic field emerges at low
energies that is not made out of elemental excitations. Such a field accounts
for dynamical spectral weight transfer across the Mott gap. At half-filling, we
show that two such excitations emerge which play a crucial role in preserving
the Luttinger surface along which the single-particle Green function vanishes.
In addition, the interactions with the bosonic fields defeat the artificial
local SU(2) symmetry that is present in the Heisenberg model. We also apply
this method to the Anderson-U impurity and show that in addition to the Kondo
interaction, bosonic degrees of freedom appear as well. Finally, we show that
as a result of the bosonic degree of freedom, the electron at low energies is
in a linear superposition of two excitations--one arising from the standard
projection into the low-energy sector and the other from the binding of a hole
and the boson.


title:
Changeover from Glassy ferromagnetism of the orbital domain state to
  long range ferromagnetic ordering in La{_{0.9}}Sr_{0.1}MnO{_3}

abstract:
  An attempt is made to resolve the controversy related to the low temperature
phase (ground state) of the low-doped ferromagnetic (FM)- insulator(I)
manganite through bulk magnetic measurements on La${_{0.9}}$Sr$_{0.1}$MnO${_3}$
sample. It is shown that the FM phase, formed out of well defined transition in
the low-doped system, becomes inhomogeneous with decrease in temperature. This
inhomogeniety is considered to be an outcome of the formation of orbital domain
state of e$_g$-electrons having hole rich (metallic) walls separating the hole
deficient (insulating) regions. The resulting complexity brings in
metastability and glassy behaviour within the FM phase at low temperature,
however, with no resemblance to spin glass, cluster glass or reentrant phases.
It shows ageing effect without memory but magnetic relaxation shows signatures
of inter-cluster interaction. The energy landscape picture of this glassy phase
is described in terms of hierarchical model. Further, it is shown that this
inhomogeneity disappear in La${_{0.9}}$Sr$_{0.1}$MnO$_{3.08}$ where, the
orbital domain state is destroyed by self doping resulting in reduction of
Mn$^{3+}$ and hence e$_g$-electrons. The ferromagnetic phase of the
non-stoichiometric sample, does not show glassy behaviour. It neither follows
'hierarchical model' nor 'droplet model' generally used to explain glassy or
inhomogeneous systems. Its magnetic response can be explained simply from the
domain wall dynamics of otherwise homogeneous ferromagnet.


title: How Magnetic is the Neutrino?

abstract:
  The existence of a neutrino magnetic moment implies contributions to the
neutrino mass via radiative corrections. We derive model-independent
"naturalness" upper bounds on the magnetic moments of Dirac and Majorana
neutrinos, generated by physics above the electroweak scale. For Dirac
neutrinos, the bound is several orders of magnitude more stringent than present
experimental limits. However, for Majorana neutrinos the magnetic moment bounds
are weaker than present experimental limits if $\mu_\nu$ is generated by new
physics at ~ 1 TeV, and surpass current experimental sensitivity only for new
physics scales > 10 -- 100 TeV. The discovery of a neutrino magnetic moment
near present limits would thus signify that neutrinos are Majorana particles.


title: Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres

abstract:
  Previous research has indicated that high amounts of ozone (O3) and oxygen
(O2) may be produced abiotically in atmospheres with high concentrations of
CO2. The abiotic production of these two gases, which are also characteristic
of photosynthetic life processes, could pose a potential "false-positive" for
remote-sensing detection of life on planets around other stars.We show here
that such false positives are unlikely on any planet that possesses abundant
liquid water, as rainout of oxidized species onto a reduced planetary surface
should ensure that atmospheric H2 concentrations remain relatively high, and
that O2 and O3 remain low. Our aim is to determine the amount of O3 and O2
formed in a high CO2 atmosphere for a habitable planet without life. We use a
photochemical model that considers hydrogen (H2) escape and a detailed hydrogen
balance to calculate the O2 and O3 formed on planets with 0.2 of CO2 around the
Sun, and 0.02, 0.2 and 2 bars of CO2 around a young Sun-like star with higher
UV radiation. The concentrations obtained by the photochemical model were used
as input in a radiative transfer model that calculated the spectra of the
modeled planets. The O3 and O2 concentrations in the simulated planets are
extremely small, and unlikely to produce a detectable signature in the spectra
of those planets. We conclude that with a balanced hydrogen budget, and for
planets with an active hydrological cycle, abiotic formation of O2 and O3 is
unlikely to create a possible false positive for life detection in either the
visible/near-infrared or mid-infrared wavelength regimes.


title: Autonomy with regard to an Attribute

abstract:
  This paper presents a model of autonomy called autonomy with regard to an
attribute applicable to cognitive and not cognitive artificial agents. Three
criteria (global / partial, social / nonsocial, absolute / relative) are
defined and used to describe the main characteristics of this type of autonomy.
A software agent autonomous with regard to the mobility illustrates a possible
implementation of this model.


title: An accurate finite element method for elliptic interface problems

abstract:
  A finite element method for elliptic problems with discontinuous coefficients
is presented. The discontinuity is assumed to take place along a closed smooth
curve. The proposed method allows to deal with meshes that are not adapted to
the discontinuity line. The (nonconforming) finite element space is enriched
with local basis functions. We prove an optimal convergence rate in the
$H^1$--norm. Numerical tests confirm the theoretical results.


title:
The Analysis of Penumbral Fine Structure Using an Advanced Inversion
  Technique

abstract:
  We present a method to study the penumbral fine structure using data obtained
by the spectropolarimeter onboard HINODE. For the first time, the penumbral
filaments can be considered as resolved in spectropolarimetric measurements.
This enables us to use inversion codes with only one-component model
atmospheres, and thus assign the obtained stratifications of plasma parameters
directly to the penumbral fine structure. This approach is applied to the
limb-side part of the penumbra in active region NOAA 10923. The preliminary
results show a clear dependence of the plasma parameters on continuum intensity
in the inner penumbra, i.e. weaker and horizontal magnetic field along with
increased line-of-sight velocity are found in the low layers of the bright
filaments. The results in the mid penumbra are ambiguous and future analyses
are necessary to unveil the magnetic field structure and other plasma
parameters there.


title: The Reionization and Galaxy Evolution Probed by z=7 Lyman Alpha Emitters

abstract:
  We made a narrowband NB973 (bandwidth of 200A at 9755A) imaging of the Subaru
Deep Field (SDF) and found two z=7 Lyman alpha emitter (LAE) candidates down to
NB973=24.9. Carrying out deep follow-up spectroscopy, we identified one of them
as a real z=6.96 LAE. This has shown that galaxy formation was in progress just
750 Myr after the Big Bang. Meanwhile, the Lyman alpha line luminosity function
of LAE is known to decline from z=5.7 to 6.6 in the SDF. L* at z=6.6 is 40-60%
of that at z=5.7. We also confirm that the number density of z=7 LAE is only
17% of the density at z=6.6 comparing the latest SDF LAE samples. This series
of significant decreases in LAE density with increasing redshift can be the
result of galaxy evolution during these epochs. However, using the UV continuum
luminosity functions of LAEs, those of Lyman break galaxies, and a LAE
evolution model based on the hierarchical clustering, we find that galaxy
evolution alone cannot explain all the decrease in density. This extra density
deficit can be interpreted as the attenuation of the Lyman alpha photons from
LAEs due to a rapid evolution of neutral hydrogen fraction during the ongoing
cosmic reionization at z~6.6-7.


title: Percolation cluster formation at ultrarelativistic heavy ion collisions

abstract:
  We expect that the experimental study of percolation cluster formation and
appearance of the critical transparency of the strongly interacting matter can
give the information about the onset state of deconfinement.


title: Rare Decay Modes of Quarter BPS Dyons

abstract:
  The degeneracy of quarter BPS dyons in N=4 supersymmetric string theories is
known to jump across walls of marginal stability on which a quarter BPS dyon
can decay into a pair of half BPS dyons. We show that as long as the electric
and magnetic charges of the original dyon are primitive elements of the charge
lattice, the subspaces of the moduli space on which a quarter BPS dyon becomes
marginally unstable against decay into a pair of quarter BPS dyons or a half
BPS dyon and a quarter BPS dyon are of codimension two or more. As a result any
pair of generic points in the moduli space can be connected by a path avoiding
these subspaces and there is no jump in the spectrum associated with these
subspaces.


title:
Orbital-Driven Electronic Structure Changes and the Resulting Optical
  Anisotropy of the Quasi-Two-Dimensional Spin Gap Compound La4Ru2O10

abstract:
  We investigated the electronic response of the quasi-two-dimensional spin gap
compound La4Ru2O10 using optical spectroscopy. We observed drastic changes in
the optical spectra as the temperature decreased, resulting in anisotropy in
the electronic structure of the spin-singlet ground state. Using the
orbital-dependent hopping analysis, we found that orbital ordering plays a
crucial role in forming the spin gap state in the non-one-dimensional material.


title:
Quantum state of an injected TROPO above threshold : purity, Glauber
  function and photon number distribution

abstract:
  In this paper we investigate several properties of the full signal-idler-pump
mode quantum state generated by a triply resonant non-degenerate Optical
Parametric Oscillator operating above threshold, with an injected wave on the
signal and idler modes in order to lock the phase diffusion process. We
determine and discuss the spectral purity of this state, which turns out not to
be always equal to 1 even though the three interacting modes have been taken
into account at the quantum level. We have seen that the purity is essentially
dependent on the weak intensity of the injected light and on an asymmetry of
the synchronization. We then derive the expression of its total three-mode
Glauber P-function, and calculate the joint signal-idler photon number
probability distribution and investigate their dependence on the injection.


title: K theory of smooth complete toric varieties and related spaces

abstract:
  The K-rings of non-singular complex pro jective varieties as well as quasi-
toric manifolds were described in terms of generators and relations in an
earlier work of the author with V. Uma. In this paper we obtain a similar
description for complete non-singular toric varieties. Indeed, our approach
enables us to obtain such a description for the more general class of torus
manifolds with locally standard torus action and orbit space a homology
polytope.


title: Theory for ultrafast nonequilibrium dynamics in d-wave superconductors

abstract:
  We use density-matrix theory to calculate the ultrafast dynamics of
unconventional superconductors from a microscopic viewpoint. We calculate the
time evolution of the optical conductivity as well as pump-probe spectra for a
d-wave order parameter. Three regimes can be distinguished in the spectra. The
Drude response at low photon energies is the only one of those which has been
measured experimentally so far. At higher energies, we predict two more
regimes: the pair-breaking peak, which is reduced as Cooper-pairs are broken up
by the exciting pulse; and a suppression above the pair-breaking peak due to
nonequilibrium quasiparticles. Furthermore, we consider the influence of the
electron-phonon coupling, and derive rate equations which have been widely used
so far.


title: Rapidly Rotating Bose-Einstein Condensates in Homogeneous Traps

abstract:
  We extend the results of a previous paper on the Gross-Pitaevskii description
of rotating Bose-Einstein condensates in two-dimensional traps to confining
potentials of the form V(r) = r^s, $2<s <\infty$. Writing the coupling constant
as $1/\epsilon^2$ we study the limit $\epsilon \to 0$. We derive rigorously the
leading asymptotics of the ground state energy and the density profile when the
rotation velocity \Omega tends to infinity as a power of $1/\epsilon$. The case
of asymptotically homogeneous potentials is also discussed.

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


title:
Cell-to-Cell stochastic fluctuations in apoptotic signaling can decide
  between life and death

abstract:
  Apoptosis, or genetically programmed cell death, is a crucial cellular
process that maintains the balance between life and death in cells. The precise
molecular mechanism of apoptosis signaling and how these two pathways are
differentially activated under distinct apoptotic stimuli is poorly understood.
We developed a Monte Carlo-based stochastic simulation model that can
characterize distinct signaling behaviors in the two major pathways of
apoptotic signaling using a novel probability distribution-based approach.
Specifically, we show that for a weak death signal, such as low levels of death
ligand Fas (CD95) binding or under stress conditions, the type 2 mitochondrial
pathway dominates apoptotic signaling. Our results also show signaling in the
type 2 pathway is stochastic, where the population average over many cells does
not capture the cell-to-cell fluctuations in the time course (~1 - 10 hours) of
downstream caspase-3 activation. On the contrary, the probability distribution
of caspase-3 activation for the mitochondrial pathway shows a distinct bimodal
behavior that can be used to characterize the stochastic signaling in type 2
apoptosis. Interestingly, such stochastic fluctuations in apoptosis signaling
happen even in the presence of large numbers of signaling molecules. In a
fluctuating environment, such stochasticity in the timecourse of caspase-3
activation may be an adaptive mechanism for allowing a competing survival
signal to win over a weak death trigger before the critical cell fate decision
is made and thus minimizes the risk of pathologies.


title: About the isotropy constant of random convex sets

abstract:
  Let K be the symmetric convex hull of m independent random vectors uniformly
distributed on the unit sphere of R^n. We prove that, for every $\delta>0$, the
isotropy constant of K is bounded by a constant $c(\delta)$ with high
probability, provided that $m\geq (1+\delta)n$.


title: Observations on the motion of a Tachyon

abstract:
  Some aspects of the motion of a tachyon is discussed. It is shown that the
inertial frame Sigma-Prime around which the tachyon switches the direction of
its motion, does not observe any movement of the tachyon at all. Inertial
frames on either side of Sigma-Prime observe the tachyon to be moving at very
large speeds but in opposite direction. Sigma-Prime itself observes only a
sudden appearance and immediate disappearance of a long rod like object. Thus
unbounded speeds in either direction give the same result in the limit. This
suggests that negative numbers as a physical quantity are not meaningful.
Subtraction can be used integral to a formula but the final result has to be
interpreted with a positive answer. This means the abstract quantity -infinity
indicating an unbounded negative number is not meaningful. The situation is
also compared with Tan (Pi/2)+ and Tan(Pi/2)-. The conclusion is that in the
limit, travel at unbounded speed is direction independent and gives the
connotation of many identities to the same particle.


title: Switched Control of Electron Nuclear Spin Systems

abstract:
  In this article, we study control of electron-nuclear spin dynamics at
magnetic field strengths where the Larmor frequency of the nucleus is
comparable to the hyperfine coupling strength. The quantization axis for the
nuclear spin differs from the static B_0 field direction and depends on the
state of the electron spin. The quantization axis can be switched by flipping
the state of electron spin, allowing for universal control on nuclear spin
states. We show that by performing a sequence of flips (each followed by a
suitable delay), we can perform any desired rotation on the nuclear spins,
which can also be conditioned on the state of the electron spin. These
operations, combined with electron spin rotations can be used to synthesize any
unitary transformation on the coupled electron-nuclear spin system. We discuss
how these methods can be used for design of experiments for transfer of
polarization from the electron to the nuclear spins.


title:
X-ray measured metallicities of the intra-cluster medium: a good measure
  for the metal mass?

abstract:
  Aims. We investigate whether X-ray observations map heavy elements in the
Intra-Cluster Medium (ICM) well and whether the X-ray observations yield good
estimates for the metal mass, with respect to predictions on transport mech-
anisms of heavy elements from galaxies into the ICM. We further test the
accuracy of simulated metallicity maps. Methods. We extract synthetic X-ray
spectra from N-body/hydrodynamic simulations including metal enrichment pro-
cesses, which we then analyse with the same methods as are applied to
observations. By changing the metal distribution in the simulated galaxy
clusters, we investigate the dependence of the overall metallicity as a
function of the metal distribution. In addition we investigate the difference
of X-ray weighted metal maps produced by simulations and metal maps extracted
from artifcial X-ray spectra, which we calculate with SPEX2.0 and analyse with
XSPEC12.0. Results. The overall metallicity depends strongly on the
distribution of metals within the galaxy cluster. The more inhomogeneously the
metals are distributed within the cluster, the less accurate is the metallicity
as a measure for the true metal mass. The true metal mass is generally
underestimated by X-ray observations. The difference between the X-ray weighted
metal maps and the metal maps from synthetic X-ray spectra is on average less
than 7% in the temperature regime above T > 3E7 K, i.e. X-ray weighted metal
maps can be well used for comparison with observed metal maps. Extracting the
metal mass in the central parts (r < 500 kpc) of galaxy clusters with X-ray
observations results in metal mass underestimates up to a factor of three.


title: Three loop anomalous dimensions of twist-3 gauge operators in N=4 SYM

abstract:
  We propose a closed expression for the three loop anomalous dimension of a
class of twist-3 operators built with gauge fields and covariant derivatives.
To this aim, we solve the long-range Bethe Ansatz equations at finite spin and
provide a consistent analytical formula obtained assuming maximal
transcendentality violation as suggested by the known one-loop anomalous
dimension. The final result reproduces the universal cusp anomalous dimension
and obeys recursion relations inspired by the principle of reciprocity
invariance.


title: Entanglement of a class of mixed two - qutrit states

abstract:
  We compute the measure of entanglement for some classes of states belonging
to the simplex of Bell - diagonal states of two qutrits.


title: Symbol calculus and zeta--function regularized determinants

abstract:
  In this work, we use semigroup integral to evaluate zeta-function regularized
determinants. This is especially powerful for non--positive operators such as
the Dirac operator. In order to understand fully the quantum effective action
one should know not only the potential term but also the leading kinetic term.
In this purpose we use the Weyl type of symbol calculus to evaluate the
determinant as a derivative expansion. The technique is applied both to a
spin--0 bosonic operator and to the Dirac operator coupled to a scalar field.


title: k-Ordered Hamilton cycles in digraphs

abstract:
  Given a digraph D, the minimum semi-degree of D is the minimum of its minimum
indegree and its minimum outdegree. D is k-ordered Hamiltonian if for every
ordered sequence of k distinct vertices there is a directed Hamilton cycle
which encounters these vertices in this order. Our main result is that every
digraph D of sufficiently large order n with minimum semi-degree at least
(n+k)/2 -1 is k-ordered Hamiltonian. The bound on the minimum semi-degree is
best possible. An undirected version of this result was proved earlier by
Kierstead, S\'ark\"ozy and Selkow.


title: Entangled multi-qubit states without higher-tangle

abstract:
  We analyze mixed multi-qubit states composed of a W class state and a product
state with all qubit in |0>. We find the optimal pure state decomposition and
convex roofs for higher-tangle with bipartite partition between one qubit and
the rest qubits for those mixed states. The optimality of the decomposition is
ensured by the Coffman-Kundu-Wootters (CKW) inequality which describes the
monogamy of quantum entanglement. The generalized monogamy inequality is found
to be true for W class states with arbitrary partitions between one qubit and
multi-qubit.


title: Stable stochastic dynamics in yeast cell cycle

abstract:
  Chemical reactions in cell are subject to intense stochastic fluctuations. An
important question is how the fundamental physiological behavior of cell is
kept stable against those noisy perturbations. In this paper a stochastic model
of cell cycle of budding yeast is constructed to analyze the effects of noise
on the cell cycle oscillation. The model predicts intense noise in levels of
mRNAs and proteins, and the simulated protein levels explain the observed
statistical tendency of noise in populations of synchronous and asynchronous
cells. In spite of intense noise in levels of proteins and mRNAs, cell cycle is
stable enough to bring the largely perturbed cells back to the physiological
cyclic oscillation. The model shows that consecutively appearing fixed points
are the origin of this stability of cell cycle.


title: Theoretical Analysis of Astronomical Phased Arrays

abstract:
  Low-noise phased arrays are essential for the next generation of microwave
and submillimetre wave astronomy. We analyze their behaviour from a functional
perspective, and show that their operation is intimately related to the
mathematical theory of frames. No assumptions are made about the orthogonality
or linear independence of the synthesised beams. Frame theory allows an
unambiguous assessment of whether the outputs of an array can be used to
observe a field or brightness distribution within a given class. Image
reconstruction is carried out using dual beams. We identify the natural modes
of phased arrays, and carry out an analysis of noise. The scheme allows the
expectation values, the mean-square fluctuations, and the correlations between
fluctuations at the output ports of a phased array to be determined for a
source in any state of spatial coherence. Both classical and photon-counting
statistics are included. Our model is conceptually powerful, and suggests many
simulation and image recovery techniques.


title: Statistical Mechanics of the Fluctuating Lattice Boltzmann Equation

abstract:
  We propose a new formulation of the fluctuating lattice Boltzmann equation
that is consistent with both equilibrium statististical mechanics and
fluctuating hydrodynamics. The formalism is based on a generalized lattice-gas
model, with each velocity direction occupied by many particles. We show that
the most probable state of this model corresponds to the usual equilibrium
distribution of the lattice Boltzmann equation. Thermal fluctuations about this
equilibrium are controlled by the mean number of particles at a lattice site.
Stochastic collision rules are described by a Monte Carlo process satisfying
detailed balance. This allows for a straightforward derivation of discrete
Langevin equations for the fluctuating modes. It is shown that all
non-conserved modes should be thermalized, as first pointed out by Adhikari et
al.; any other choice violates the condition of detailed balance. A
Chapman-Enskog analysis is used to derive the equations of fluctuating
hydrodynamics on large length and time scales; the level of fluctuations is
shown to be thermodynamically consistent with the equation of state of an
isothermal, ideal gas. We believe this formalism will be useful in developing
new algorithms for thermal and multiphase flows.


title:
Stripe width and non-local domain walls in the two-dimensional Dipolar
  Frustrated Ising Ferromagnet

abstract:
  We describe a novel type of magnetic domain wall which, in contrast to Bloch
or Neel walls, is non-localized and, in a certain temperature range,
non-monotonic. The wall appears as the mean-field solution of the
two-dimensional ferromagnetic Ising model frustrated by the long-ranged dipolar
interaction. We provide experimental evidence of this wall delocalization in
the stripe-domain phase of perpendicularly magnetized ultrathin magnetic films.
In agreement with experimental results, we find that the stripe width decreases
with increasing temperature and approaches a finite value at the
Curie-temperature following a power law. The same kind of wall and a similar
temperature dependence of the stripe width is expected in the mean-field
approximation of the two-dimensional Coulomb frustrated Ising ferromagnet.


title: A multi-blob representation of semi-dilute polymer solutions

abstract:
  A coarse-grained multi-blob description of polymer solutions is presented,
based on soft, transferable effective interactions between bonded and
non-bonded blobs. The number of blobs is chosen such that the blob density does
not exceed their overlap threshold, allowing polymer concentrations to be
explored deep into the semi-dilute regime. This quantitative multi-blob
description is shown to preserve known scaling laws of polymer solutions and
provides accurate estimates of amplitudes, while leading to orders of magnitude
increase of simulation efficiency and allowing analytic calculations of
structural and thermodynamic properties.


title: On the K^+D Interaction at Low Energies

abstract:
  The Kd reactions are considered in the impulse approximation with NN
final-state interactions (NN FSI) taken into account. The realistic parameters
for the KN phase shifts are used. The "quasi-elastic" energy region, in which
the elementary KN interaction is predominantly elastic, is considered. The
theoretical predictions are compared with the data on the K^+d->K^+pn,
K^+d->K^0pp, K^+d->K^+d and K^+d total cross sections. The NN FSI effect in the
reaction K^+d->K^+pn has been found to be large. The predictions for the Kd
cross sections are also given for slow kaons, produced from phi(1020) decays,
as the functions of the isoscalar KN scattering length a_0. These predictions
can be used to extract the value of a_0 from the data.


title:
Experimental application of sum rules for electron energy loss magnetic
  chiral dichroism

abstract:
  We present a derivation of the orbital and spin sum rules for magnetic
circular dichroic spectra measured by electron energy loss spectroscopy in a
transmission electron microscope. These sum rules are obtained from the
differential cross section calculated for symmetric positions in the
diffraction pattern. Orbital and spin magnetic moments are expressed explicitly
in terms of experimental spectra and dynamical diffraction coefficients. We
estimate the ratio of spin to orbital magnetic moments and discuss first
experimental results for the Fe L_{2,3} edge.


title:
Charged-Particle Multiplicities in Charged-Current Neutrino-- and
  Anti-Neutrino--Nucleus Interactions

abstract:
  The CHORUS experiment, designed to search for $\nu_{\mu}\to\nu_{\tau}$
oscillations, consists of a nuclear emulsion target and electronic detectors.
In this paper, results on the production of charged particles in a small sample
of charged-current neutrino-- and anti-neutrino--nucleus interactions at high
energy are presented. For each event, the emission angle and the ionization
features of the charged particles produced in the interaction are recorded,
while the standard kinematic variables are reconstructed using the electronic
detectors. The average multiplicities for charged tracks, the pseudo-rapidity
distributions, the dispersion in the multiplicity of charged particles and the
KNO scaling are studied in different kinematical regions. A study of
quasi-elastic topologies performed for the first time in nuclear emulsions is
also reported. The results are presented in a form suitable for use in the
validation of Monte Carlo generators of neutrino--nucleus interactions.


title:
Constraints on Neutralino masses and mixings from Cosmology and Collider
  Physics

abstract:
  Bounds on cross section measurements of chargino pair production at LEP yield
a bound on the chargino mass. If the GUT relation is assumed, the lightest
neutralino must be heavier than $\approx 45 -50\GeV$. If no GUT relation is
assumed, no lower bound on the neutralino mass exists. I derive mass bounds on
the lightest neutralino from relic density measurements for relativistic and
non-relativistic neutralinos and I derive bounds on the selectron mass from the
observed limits on the cross section of the neutralino pair production process
$e^+e^-\to \x{1}\x{2}$ at LEP, if the lightest neutralino is massless. I
further discuss radiative neutralino production and its background at the
future ILC. Finally, I present a method to determine the neutralino couplings
to right and left handed selectrons and Z bosons from cross section
measurements of radiative neutralino production and neutralino pair production
at the ILC.


title:
A Tight Lower Bound to the Outage Probability of Discrete-Input
  Block-Fading Channels

abstract:
  In this correspondence, we propose a tight lower bound to the outage
probability of discrete-input Nakagami-m block-fading channels. The approach
permits an efficient method for numerical evaluation of the bound, providing an
additional tool for system design. The optimal rate-diversity trade-off for the
Nakagami-m block-fading channel is also derived and a tight upper bound is
obtained for the optimal coding gain constant.


title: Analytic theory of narrow lattice solitons

abstract:
  The profiles of narrow lattice solitons are calculated analytically using
perturbation analysis. A stability analysis shows that solitons centered at a
lattice (potential) maximum are unstable, as they drift toward the nearest
lattice minimum. This instability can, however, be so weak that the soliton is
``mathematically unstable'' but ``physically stable''. Stability of solitons
centered at a lattice minimum depends on the dimension of the problem and on
the nonlinearity. In the subcritical and supercritical cases, the lattice does
not affect the stability, leaving the solitons stable and unstable,
respectively. In contrast, in the critical case (e.g., a cubic nonlinearity in
two transverse dimensions), the lattice stabilizes the (previously unstable)
solitons. The stability in this case can be so weak, however, that the soliton
is ``mathematically stable'' but ``physically unstable''.