title:
SN 2005hj: Evidence for Two Classes of Normal-Bright SNe Ia and
  Implications for Cosmology

abstract:
  HET Optical spectra covering the evolution from about 6 days before to about
5 weeks after maximum light and the ROTSE-IIIb unfiltered light curve of the
"Branch-normal" Type Ia Supernova SN 2005hj are presented. The host galaxy
shows HII region lines at redshift of z=0.0574, which puts the peak unfiltered
absolute magnitude at a somewhat over-luminous -19.6. The spectra show weak and
narrow SiII lines, and for a period of at least 10 days beginning around
maximum light these profiles do not change in width or depth and they indicate
a constant expansion velocity of ~10,600 km/s. We analyzed the observations
based on detailed radiation dynamical models in the literature. Whereas delayed
detonation and deflagration models have been used to explain the majority of
SNe Ia, they do not predict a long velocity plateau in the SiII minimum with an
unvarying line profile. Pulsating delayed detonations and merger scenarios form
shell-like density structures with properties mostly related to the mass of the
shell, M_shell, and we discuss how these models may explain the observed SiII
line evolution; however, these models are based on spherical calculations and
other possibilities may exist. SN 2005hj is consistent with respect to the
onset, duration, and velocity of the plateau, the peak luminosity and, within
the uncertainties, with the intrinsic colors for models with M_shell=0.2 M_sun.
Our analysis suggests a distinct class of events hidden within the
Branch-normal SNe Ia. If the predicted relations between observables are
confirmed, they may provide a way to separate these two groups. We discuss the
implications of two distinct progenitor classes on cosmological studies
employing SNe Ia, including possible differences in the peak luminosity to
light curve width relation.


title: Nuclear Suppression of Jets and R_AA at the LHC

abstract:
  The nuclear modification factor R_AA for charged hadron production at the LHC
is predicted from jet energy loss induced by gluon bremsstrahlung. The Arnold,
Moore, and Yaffe formalism is used, together with an ideal hydrodynamical
model.


title:
Weather in stellar atmosphere: the dynamics of mercury clouds in alpha
  Andromedae

abstract:
  The formation of long-lasting structures at the surfaces of stars is commonly
ascribed to the action of strong magnetic fields. This paradigm is supported by
observations of evolving cool spots in the Sun and active late-type stars, and
stationary chemical spots in the early-type magnetic stars. However, results of
our seven-year monitoring of mercury spots in non-magnetic early-type star
alpha Andromedae show that the picture of magnetically-driven structure
formation is fundamentally incomplete. Using an indirect stellar surface
mapping technique, we construct a series of 2-D images of starspots and
discover a secular evolution of the mercury cloud cover in this star. This
remarkable structure formation process, observed for the first time in any
star, is plausibly attributed to a non-equilibrium, dynamical evolution of the
heavy-element clouds created by atomic diffusion and may have the same
underlying physics as the weather patterns on terrestrial and giant planets.


title:
Dynamic response of Ag monolayers adsorbed on Au(100) upon an
  oscillatory variation of the chemical potential: A Monte Carlo simulation
  study

abstract:
  Based on the fact that the underpotential electrochemical deposition of Ag
atoms on the $Au(100)$ surface exhibits sharp first-order phase transitions at
well-defined values of the (coexistence) chemical potential ($\mu_{coex}$), we
performed extensive simulations aimed at investigating the hysteretic dynamic
behavior of the system close to coexistence upon the application of a periodic
signal of the form $\mu(t) = \mu_{coex} + \mu_{o}sin(2\Pi t/\tau) $, where
$\mu_{o}$ and $\tau$ are the amplitude and the period of the sweep,
respectively. For relatively short periods and small enough amplitudes the
system becomes trapped either at low or high Ag coverage states, as evidenced
by recording hysteresis loops. This scenario is identified as dynamically
ordered states (DOS), such that the relaxation time $(\tau_{relax})$ of the
corresponding metastable state obeys $\tau_{relax} > \tau $. On the other hand,
by properly increasing $\mu_{o}$ or/and $\tau$, one finds that the $Ag$
coverage gently follows the external drive (here $\tau_{relax} < \tau $) and
the system is said to enter into dynamically disordered states (DDS), where
hysteresis loops show almost symmetric limiting cycles. This symmetry breaking
between limiting cycles driven by an external signal is discussed in terms of
the concept of (out-of-equilibrium) Dynamic Phase Transitions between DOS and
DDS, similar to those encountered when a magnetic system is placed in the
presence of a variable external magnetic field. However, a careful finite-size
scaling study reveals that, at least at $T = 300K$, the $Ag/Au(100)$ system
does not exhibit true second-order phase transitions but rather a crossover
behavior between states. A diagram showing the location of the ordered and
disordered states in the $\mu$ versus $\tau$ plane is obtained and discussed.


title: Kerr-Schild Structure and Harmonic 2-forms on (A)dS-Kerr-NUT Metrics

abstract:
  We demonstrate that the general (A)dS-Kerr-NUT solutions in D dimensions with
([D/2], [(D+1)/2]) signature admit [D/2] linearly-independent,
mutually-orthogonal and affinely-parameterised null geodesic congruences. This
enables us to write the metrics in a multi-Kerr-Schild form, where the mass and
all of the NUT parameters enter the metrics linearly. In the case of D=2n, we
also obtain n harmonic 2-forms, which can be viewed as charged (A)dS-Kerr-NUT
solution at the linear level of small-charge expansion, for the
higher-dimensional Einstein-Maxwell theories. In the BPS limit, these 2-forms
reduce to n-1 linearly-independent ones, whilst the resulting Calabi-Yau metric
acquires a Kahler 2-form, leaving the total number the same.


title: Cosmological implications of Gamma Ray Bursts

abstract:
  The discovery that the bolometric energetics (and/or peak luminosity) of
Gamma Ray Bursts correlates with their spectral properties has allowed to
standardize the burst energetics to such a degree to enable their use for
constraining the cosmological parameters, in the same way as SN Ia. With
respect to SN Ia, there is the advantage of having sources free from extinction
problems, and easily detectable also at large redshifts. On the other hand,
these spectral-energy correlations are not yet understood, and bursts with a
complete set of information (to standardize their energetics) are still few
(two dozens). There have been already attempts to use these bursts to constrain
Omega_Lambda and Omega_M, and even the dark energy equation of state. These
results are very encouraging.


title:
Two-point correlation function of the fractional Ornstein-Uhlenbeck
  process

abstract:
  We calculate the two-point correlation function <x(t2)x(t1)> for a
subdiffusive continuous time random walk in a parabolic potential, generalizing
well-known results for the single-time statistics to two times. A closed
analytical expression is found for initial equilibrium, revealing a clear
deviation from a Mittag-Leffler decay.


title:
Study of Damage Propagation at the Interface Localization-Delocalization
  Transition of the Confined Ising Model

abstract:
  The propagation of damage in a confined magnetic Ising film, with short range
competing magnetic fields ($h$) acting at opposite walls, is studied by means
of Monte Carlo simulations. Due to the presence of the fields, the film
undergoes a wetting transition at a well defined critical temperature $T_w(h)$.
In fact, the competing fields causes the occurrence of an interface between
magnetic domains of different orientation. For $T < T_w(h)$ ($T > T_w(h)$) such
interface is bounded (unbounded) to the walls, while right at $T_w(h)$ the
interface is essentially located at the center of the film.
  It is found that the spatio-temporal spreading of the damage becomes
considerably enhanced by the presence of the interface, which act as a
''catalyst'' of the damage causing an enhancement of the total damaged area.
The critical points for damage spreading are evaluated by extrapolation to the
thermodynamic limit using a finite-size scaling approach. Furthermore, the
wetting transition effectively shifts the location of the damage spreading
critical points, as compared with the well known critical temperature of the
order-disorder transition characteristic of the Ising model. Such a critical
points are found to be placed within the non-wet phase.


title:
Dynamical heterogeneities and the breakdown of the Stokes-Einstein and
  Stokes-Einstein-Debye relations in simulated water

abstract:
  We study the Stokes-Einstein (SE) and the Stokes-Einstein-Debye (SED)
relations using molecular dynamics simulations of the extended simple point
charge model of water. We find that both the SE and SED relations break down at
low temperature. To explore the relationship between these breakdowns and
dynamical heterogeneities (DH), we also calculate the SE and SED relations for
subsets of the 7% ``fastest'' and 7% ``slowest'' molecules. We find that the SE
and SED relations break down in both subsets, and that the breakdowns occur on
all scales of mobility. Thus these breakdowns appear to be generalized
phenomena, in contrast with the view where only the most mobile molecules are
the origin of the breakdown of the SE and SED relations, embedded in an
inactive background where these relations hold. At low temperature, the SE and
SED relations in both subsets of molecules are replaced with ``fractional'' SE
and SED relations, $D_t\sim(\tau/T)^{-\xi_t}$ and $D_r\sim(\tau/T)^{-\xi_r}$
where $\xi_t\approx0.84<1$ and $\xi_r\approx0.75<1$. We also find that there is
a decoupling between rotational and translational motion, and that this
decoupling occurs in both fastest and slowest subsets of molecules. We also
find that when the decoupling increases, upon cooling, the probability of a
molecule being classified as both translationally and rotationally fastest also
increases. To study the effect of time scale for SE and SED breakdown and
decoupling, we introduce a time-dependent version of the SE and SED relations,
and a time-dependent function that measures the extent of decoupling. Our
results suggest that both the decoupling and SE and SED breakdowns are
originated at the time scale corresponding to the end of the cage regime, when
diffusion starts. This is also the time scale when the DH are more relevant.


title: Network tomography based on 1-D projections

abstract:
  Network tomography has been regarded as one of the most promising
methodologies for performance evaluation and diagnosis of the massive and
decentralized Internet. This paper proposes a new estimation approach for
solving a class of inverse problems in network tomography, based on marginal
distributions of a sequence of one-dimensional linear projections of the
observed data. We give a general identifiability result for the proposed method
and study the design issue of these one dimensional projections in terms of
statistical efficiency. We show that for a simple Gaussian tomography model,
there is an optimal set of one-dimensional projections such that the estimator
obtained from these projections is asymptotically as efficient as the maximum
likelihood estimator based on the joint distribution of the observed data. For
practical applications, we carry out simulation studies of the proposed method
for two instances of network tomography. The first is for traffic demand
tomography using a Gaussian Origin-Destination traffic model with a power
relation between its mean and variance, and the second is for network delay
tomography where the link delays are to be estimated from the end-to-end path
delays. We compare estimators obtained from our method and that obtained from
using the joint distribution and other lower dimensional projections, and show
that in both cases, the proposed method yields satisfactory results.


title:
The Future of the Local Large Scale Structure: the roles of Dark Matter
  and Dark Energy

abstract:
  We study the distinct effects of Dark Matter and Dark Energy on the future
evolution of nearby large scale structures using constrained N-body
simulations. We contrast a model of Cold Dark Matter and a Cosmological
Constant (LCDM) with an Open CDM (OCDM) model with the same matter density
Omega_m =0.3 and the same Hubble constant h=0.7. Already by the time the scale
factor increased by a factor of 6 (29 Gyr from now in LCDM; 78 Gyr from now in
OCDM) the comoving position of the Local Group is frozen. Well before that
epoch the two most massive members of the Local Group, the Milky Way and
Andromeda, will merge. However, as the expansion rates of the scale factor in
the two models are different, the Local Group will be receding in physical
coordinates from Virgo exponentially in a LCDM model and at a roughly constant
velocity in an OCDM model. More generally, in comoving coordinates the future
large scale structure will look like a sharpened image of the present
structure: the skeleton of the cosmic web will remain the same, but clusters
will be more `isolated' and the filaments will become thinner. This implies
that the long-term fate of large scale structure as seen in comoving
coordinates is determined primarily by the matter density. We conclude that
although the LCDM model is accelerating at present due to its Dark Energy
component while the OCDM model is non accelerating, their large scale structure
in the future will look very similar in comoving coordinates.


title:
Experimental constraints for additional short-range forces from neutron
  experiments

abstract:
  We present preliminary results on sensitivity of experiments with slow
neutrons to constrain additional forces in a wide distance range: from
picometers to micrometers. In the sub-nanometer range, available data on
lengths of neutron scattering at nuclei provide the most competitive
constraint. We show that it can be improved significantly in a dedicated
measurement of asymmetry of neutron scattering at noble gases. In the
micrometer range, we present sensitivity of the future GRANIT experiment.
Further analysis will be presented in following publications.


title:
Nonequilibrium quantum-impurities: from entropy production to
  information theory

abstract:
  Nonequilibrium steady-state currents, unlike their equilibrium counterparts,
continuously dissipate energy into their physical surroundings leading to
entropy production and time-reversal symmetry breaking. This letter discusses
these issues in the context of quantum impurity models driven out of
equilibrium by attaching the impurity to leads at different chemical potentials
and temperatures. We start by pointing out that entropy production is often
hidden in traditional treatments of quantum-impurity models. We then use simple
thermodynamic arguments to define the rate of entropy production. Using the
scattering framework recently developed by the authors we show that the rate of
entropy production has a simple information theoretic interpretation in terms
of the Shannon entropy and Kullback-Leibler divergence of nonequilibrium
distribution function. This allows us to show that the entropy production is
strictly positive for any nonequilibrium steady-state. We conclude by applying
these ideas to the Resonance Level Model and the Kondo model.


title:
Cassini UVIS Observations of the Io Plasma Torus. IV. Modeling Temporal
  and Azimuthal Variability

abstract:
  In this fourth paper in a series, we present a model of the remarkable
temporal and azimuthal variability of the Io plasma torus observed during the
Cassini encounter with Jupiter. Over a period of three months, the Cassini
Ultraviolet Imaging Spectrograph (UVIS) observed a dramatic variation in the
average torus composition. Superimposed on this long-term variation, is a
10.07-hour periodicity caused by an azimuthal variation in plasma composition
subcorotating relative to System III longitude. Quite surprisingly, the
amplitude of the azimuthal variation appears to be modulated at the beat
frequency between the System III period and the observed 10.07-hour period.
Previously, we have successfully modeled the months-long compositional change
by supposing a factor of three increase in the amount of material supplied to
Io's extended neutral clouds. Here, we extend our torus chemistry model to
include an azimuthal dimension. We postulate the existence of two azimuthal
variations in the number of super-thermal electrons in the torus: a primary
variation that subcorotates with a period of 10.07 hours and a secondary
variation that remains fixed in System III longitude. Using these two hot
electron variations, our model can reproduce the observed temporal and
azimuthal variations observed by Cassini UVIS.


title: Singularities of generic projection hypersurfaces

abstract:
  Linearly projecting smooth projective varieties provides a method of
obtaining hypersurfaces birational to the original varieties. We show that in
low dimension, the resulting hypersurfaces only have Du Bois singularities.
Moreover, we conclude that these Du Bois singularities are in fact semi log
canonical. However, we demonstrate the existence of counterexamples in high
dimension -- the generic linear projection of certain varieties of dimension 30
or higher is neither semi log canonical nor Du Bois.


title: Discrete Nonlinear Breathing Modes in Carbon Nanotubes

abstract:
  We study large-amplitude oscillations of carbon nanotubes with chiralities
$(m,0)$ and $(m,m)$ and predict the existence of localized nonlinear modes in
the form of {\em discrete breathers}. In nanotubes with the index $(m,0)$ {\em
three types} of localized modes can exist, namely longitudinal, radial, and
twisting breathers; however only the twisting breathers, or {\em twistons}, are
nonradiating nonlinear modes which exist in the frequency gaps of the linear
spectrum. Geometry of carbon nanotubes with the index $(m,m)$ allows only the
existence of broad radial breathers in a narrow spectral range.


title: The Label Algorithm For Irreducible Decomposition of Monomial Ideals

abstract:
  The paper that was here is a preprint that was never turned into a proper
paper. In particular it does not have enough citations to the literature. The
paper "The Slice Algorithm For Irreducible Decomposition of Monomial Ideals"
contains a much better description of the Label algorithm than this preprint
did. If you still wish to read the original preprint then access the arXiv's
version 1 of this paper, instead of version 2 which is what you are reading
now.


title: Stationary axisymmetric solutions of five dimensional gravity

abstract:
  We consider stationary axisymmetric solutions of general relativity that
asymptote to five dimensional Minkowski space. It is known that this system has
a hidden SL(3,R) symmetry. We identify an SO(2,1) subgroup of this symmetry
group that preserves the asymptotic boundary conditions. We show that the
action of this subgroup on a static solution generates a one-parameter family
of stationary solutions carrying angular momentum. We conjecture that by
repeated applications of this procedure one can generate all stationary
axisymmetric solutions starting from static ones. As an example, we derive the
Myers-Perry black hole starting from the Schwarzschild solution in five
dimensions.


title: Mixed membership stochastic blockmodels

abstract:
  Observations consisting of measurements on relationships for pairs of objects
arise in many settings, such as protein interaction and gene regulatory
networks, collections of author-recipient email, and social networks. Analyzing
such data with probabilisic models can be delicate because the simple
exchangeability assumptions underlying many boilerplate models no longer hold.
In this paper, we describe a latent variable model of such data called the
mixed membership stochastic blockmodel. This model extends blockmodels for
relational data to ones which capture mixed membership latent relational
structure, thus providing an object-specific low-dimensional representation. We
develop a general variational inference algorithm for fast approximate
posterior inference. We explore applications to social and protein interaction
networks.

categories: stat.ME cs.LG math.ST physics.soc-ph stat.ML stat.TH


title:
Crossover from weak localization to Shubnikov-de Haas oscillations in a
  high mobility 2D electron gas

abstract:
  We study the magnetoresistance, \delta\rho_{xx}(B)/\rho_0, of a high-mobility
2D electron gas in the domain of magnetic fields, B, intermediate between the
weak localization and the Shubnikov-de Haas oscillations, where
\delta\rho_{xx}(B)/\rho_0 is governed by the interaction effects. Assuming
short-range impurity scattering, we demonstrate that in the {\em second order}
in the interaction parameter, $\lambda$, a {\em linear} B-dependence,
\delta\rho_{xx}(B)/\rho_0\sim \lambda^2\omega_c/E_F with {\em
temperature-independent} slope emerges in this domain of B (here \omega_c and
E_F are the cyclotron frequency and the Fermi energy, respectively). Unlike
previous mechanisms, the linear magnetoresistance is {\em unrelated} to the
electron executing the full Larmour circle, but rather originates from the
impurity scattering via the B-dependence of the {\em phase} of the
impurity-induced Friedel oscillations.


title:
Utility Maximization with a Stochastic Clock and an Unbounded Random
  Endowment

abstract:
  We introduce a linear space of finitely additive measures to treat the
problem of optimal expected utility from consumption under a stochastic clock
and an unbounded random endowment process. In this way we establish existence
and uniqueness for a large class of utility maximization problems including the
classical ones of terminal wealth or consumption, as well as the problems
depending on a random time-horizon or multiple consumption instances. As an
example we treat explicitly the problem of maximizing the logarithmic utility
of a consumption stream, where the local time of an Ornstein-Uhlenbeck process
acts as a stochastic clock.


title: Explicit bounds for the approximation error in Benford's law

abstract:
  Benford's law states that for many random variables X > 0 its leading digit D
= D(X) satisfies approximately the equation P(D = d) = log_{10}(1 + 1/d) for d
= 1,2,...,9. This phenomenon follows from another, maybe more intuitive fact,
applied to Y := log_{10}(X): For many real random variables Y, the remainder U
:= Y - floor(Y) is approximately uniformly distributed on [0,1). The present
paper provides new explicit bounds for the latter approximation in terms of the
total variation of the density of Y or some derivative of it. These bounds are
an interesting alternative to traditional Fourier methods which yield mostly
qualitative results. As a by-product we obtain explicit bounds for the
approximation error in Benford's law.


title:
Coexistence of Antiferromagnetism and Superconductivity in
  Electron-doped High-Tc Superconductors

abstract:
  We present magnetotransport evidence for antiferromagnetism in films of the
electron-doped cuprates Pr$_{2-x}$Ce$_x$CuO$_4$. Our results show clear
signature of static antiferromagnetism up to optimal doping x=0.15, with a
quantum phase transition close to x=0.16, and a coexistence of static
antiferromagnetism and superconductivity for 0.12$\le$x$\le$0.15.


title:
Geometry-induced frustration of magnetization in a planar soft-hard
  magnetic system

abstract:
  We computationally study the frustrated magnetic configurations of a thin
soft magnetic layer with the boundary condition fixed by underlying hard
magnets. Driven by geometrical constraints and external magnetic field,
transitions between frustrated energy minima result in magnetic hysteretic
behavior. The presence of soft-magnet introduces strong undulations in the
energy landscape in a length scale set by the magnetic property of the soft
magnet. We propose a possible use of the phenomena to locally control the
movement of magnetic nanoparticles.


title:
Event Reconstruction and Data Acquisition for the RICE Experiment at the
  South Pole

abstract:
  The RICE experiment seeks to measure ultra-high energy neutrinos (E(nu)>10
PeV) by detection of the radio wavelength Cherenkov radiation produced by
neutrino-ice collisions within Antarctic ice. An array of 16 dipole antennas,
buried at depths of 100-400 m, and sensitive over the 100-500 MHz frequency
range, has been continuously taking data for the last seven years. We herein
describe the design and performance of the RICE experiment's event trigger and
data acquisition system, highlighting elements not covered as extensively in
previous publications.


title: Jets, Blazars and the EBL in the GLAST-EXIST Era

abstract:
  The synergy of GLAST and the proposed EXIST mission as the Black Hole Finder
Probe in the Beyond Einstein Program is remarkable. With its full-sky per orbit
hard X-ray imaging (3-600 keV) and "nuFnu" sensitivity comparable to GLAST,
EXIST could measure variability and spectra of Blazars in the hard X-ray
synchrotron component simultaneous with GLAST (~10-100GeV) measures of the
inverse Compton component, thereby uniquely constraining intrinsic source
spectra and allowing measured high energy spectral breaks to measure the cosmic
diffuse extra-galactic background light (EBL) by determining the intervening
diffuse IR photon field required to yield the observed break from photon-photon
absorption. Such studies also constrain the physics of jets (and parameters and
indeed the validity of SSC models) and the origin of the >100 MeV gamma-ray
diffuse background likely arising from Blazars and jet-dominated sources. An
overview of the EXIST mission, which could fly in the GLAST era, is given
together with a synopsis of other key synergies of GLAST-EXIST science.


title: Dark matter and Higgs boson physics

abstract:
  A vector-like colorless fermion doublet and a singlet added to the Standard
Model allow a consistent interpretation of dark matter in terms of the lightest
neutral particle, as they may help in obtaining successful gauge coupling
unification. We analyze in detail the mass range of the lightest neutral
particle below the W mass, i.e. in a range of the parameters where the physics
of the Standard Model Higgs boson may be substantially affected either directly
or indirectly.


title: Breathing in Low Mass Galaxies: A Study of Episodic Star Formation

abstract:
  We simulate the collapse of isolated dwarf galaxies using SPH + N-Body
simulations including a physically motivated description of the effects of
supernova feedback. As the gas collapses and stars form, the supernova feedback
disrupts enough gas to temporarily quench star formation. The gas flows outward
into a hot halo, where it cools until star formation can continue once more and
the cycle repeats. The star formation histories of isolated Local Group dwarf
galaxies exhibit similar episodic bursts of star formation. We examine the mass
dependence of the stellar velocity dispersions and find that they are no less
than half the velocity of the halos measured at the virial radius.


title: Single-brane world with stabilized extra dimension

abstract:
  We present a model describing a single brane with tension embedded into a
five-dimensional space-time with compact extra dimension, which can be easily
stabilized. We examine the linearized gravity in the model and obtain an
expression for the four-dimensional Planck mass on the brane in terms of the
model parameters. It is also shown that the scalar sector of the effective
four-dimensional theory contain a tachyonic mode, and we discuss the problem of
stability of the model.


title: Dilation Theory for Rank 2 Graph Algebras

abstract:
  An analysis is given of $*$-representations of rank 2 single vertex graphs.
We develop dilation theory for the non-selfadjoint algebras $\A_\theta$ and
$\A_u$ which are associated with the commutation relation permutation $\theta$
of a 2 graph and, more generally, with commutation relations determined by a
unitary matrix $u$ in $M_m(\bC) \otimes M_n(\bC)$. We show that a defect free
row contractive representation has a unique minimal dilation to a
$*$-representation and we provide a new simpler proof of Solel's row isometric
dilation of two $u$-commuting row contractions. Furthermore it is shown that
the C*-envelope of $\A_u$ is the generalised Cuntz algebra $\O_{X_u}$ for the
product system $X_u$ of $u$; that for $m\geq 2 $ and $n \geq 2 $ contractive
representations of $\Ath$ need not be completely contractive; and that the
universal tensor algebra $\T_+(X_u)$ need not be isometrically isomorphic to
$\A_u$.


title: Turbulence-induced magnetic flux asymmetry at nanoscale junctions

abstract:
  It was recently predicted [J. Phys.: Condens. Matter 18, 11059 (2006)] that
turbulence of the electron flow may develop at nonadiabatic nanoscale junctions
under appropriate conditions. Here we show that such an effect leads to an
asymmetric current-induced magnetic field on the two sides of an otherwise
symmetric junction. We propose that by measuring the fluxes ensuing from these
fields across two surfaces placed at the two sides of the junction would
provide direct and noninvasive evidence of the transition from laminar to
turbulent electron flow. The flux asymmetry is predicted to first increase,
reach a maximum and then decrease with increasing current, i.e. with increasing
amount of turbulence.


title: Atomic Representations of Rank 2 Graph Algebras

abstract:
  We provide a detailed analysis of atomic *-representations of rank 2 graphs
on a single vertex. They are completely classified up to unitary equivalence,
and decomposed into a direct sum or direct integral of irreducible atomic
representations. The building blocks are described as the minimal *-dilations
of defect free representations modelled on finite groups of rank 2.


title: Periodicity in Rank 2 Graph Algebras

abstract:
  Kumjian and Pask introduced an aperiodicity condition for higher rank graphs.
We present a detailed analysis of when this occurs in certain rank 2 graphs.
When the algebra is aperiodic, we give another proof of the simplicity of
$\ca(\Fth)$. The periodic C*-algebras are characterized, and it is shown that
$\ca(\Fth) \simeq \rC(\bT) \otimes \fA$ where $\fA$ is a simple C*-algebra.


title:
Determination of the $\psi(3770)$, $\psi(4040)$, $\psi(4160)$ and
  $\psi(4415)$ resonance parameters

abstract:
  $R$ measurement data taken with the BESII detector at center-of-mass energies
between 3.7 and 5.0 GeV is fitted to determine resonance parameters (mass,
total width, electron width) of the high mass charmonium states, $\psi(3770)$,
$\psi(4040)$, $\psi(4160)$ and $\psi(4415)$. Various effects, including the
relative phases between the resonances, interferences, the energy-dependence of
the full widths, and the initial state radiative correction, are examined. The
results are compared to previous studies.


title: Electronic reconstruction at SrMnO3-LaMnO3 superlattice interfaces

abstract:
  We use resonant soft x-ray scattering to study electronic reconstruction at
the interface between the Mott insulator LaMnO3 and the "band" insulator
SrMnO3. Superlattices of these two insulators were shown previously to have
both ferromagnetism and metallic tendencies [Koida et al., Phys. Rev. B 66,
144418 (2002)]. By studying a judiciously chosen superlattice reflection we
show that the interface density of states exhibits a pronounced peak at the
Fermi level, similar to that predicted by Okamoto et al. [Phys. Rev. B 70,
241104(R) (2004)]. The intensity of this peak correlates with the conductivity
and magnetization, suggesting it is the driver of metallic behavior. Our study
demonstrates a general strategy for using RSXS to probe the electronic
properties of heterostructure interfaces.


title:
Experimental indication of anomalous sensitivity in many-body systems:
  Deterministic randomness in complex quantum collisions?

abstract:
  We have experimentally tested a recently suggested possibility for anomalous
sensitivity of the cross sections of dissipative heavy ion collisions. Cross
sections for the $^{19}$F+$^{27}$Al dissipative collisions were measured at the
fixed energy 118.75 MeV of the $^{19}$F for the 12 different beam spots on the
same target foil. The data demonstrate dramatic differences between the cross
sections for the different beam spots. The effect may indicate deterministic
randomness in complex quantum collisions. New experiments are highly desirable
in a view of the fundamental importance of the problem.


title: Approximating the largest eigenvalue of network adjacency matrices

abstract:
  The largest eigenvalue of the adjacency matrix of a network plays an
important role in several network processes (e.g., synchronization of
oscillators, percolation on directed networks, linear stability of equilibria
of network coupled systems, etc.). In this paper we develop approximations to
the largest eigenvalue of adjacency matrices and discuss the relationships
between these approximations. Numerical experiments on simulated networks are
used to test our results.


title: The Volume Capture in Structures with Variable Curvature

abstract:
  The volume capture in classical relativistic mechanics is considered as a
scattering process for the high energy charged particles in a field with no
central or mirror symmetry. The parameters of volume capture for potentials
with smooth variable curvature are received and analyzed.


title:
The local supermassive black hole mass density: corrections for
  dependencies on the Hubble constant

abstract:
  We have investigated past measurements of the local supermassive black hole
mass density, correcting for hitherto unknown dependencies on the Hubble
constant, which, in some cases, had led to an underestimation of the mass
density by factors of ~2. Correcting for this, we note that the majority of
past studies yield a local supermassive black hole mas density that is
consistent with the range 4.4-5.9 x 10^5 f(H_0) M_Sun / Mpc^3 (when using H_0 =
70 km/s/Mpc). In addition, we address a number of ways in which these past
estimates can be further developed. In particular, we tabulate realistic
bulge-to-total flux ratios which can be used to estimate the luminosity of
bulges and subsequently their central black hole masses.


title: Adiabatic limit of the eta invariant over cofinite quotient of PSL(2,R)

abstract:
  We study the adiabatic limit of the eta invariant of the Dirac operator over
cofinite quotient of PSL(2,R), which is a noncompact manifold with a nonexact
fibred-cusp metric near the ends.


title: Comments on "Note on varying speed of light theories"

abstract:
  In a recent note Ellis criticizes varying speed of light theories on the
grounds of a number of foundational issues. His reflections provide us with an
opportunity to clarify some fundamental matters pertaining to these theories.


title:
The unification of Pythagorean theorem for electronic orbitals with
  Kepler's law for planetary orbits

abstract:
  In the context of two-dimensional spacetime within a helium atom, both 1s
electrons are characterized by wave functions that observe duality equation.
They are symmetric, orthogonal and interwoven, forming a dynamic rope structure
at any moment. Instead of elliptical orbit of planets around the sun,
electronic orbitals take the form of matter state transformation cycle. While
the kinematic movement of planets is governed by Kepler's first law, electronic
transformation obeys Pythagorean theorem, both being equivalent in physical
principle. The atomic spacetime is a continuous medium of electron clouds in
synchronized differential and integral processes that are implemented by smooth
trigonometry. In order to integrate this new approach with conventional
physics, the author translates the pattern of electronic motion in the atomic
spacetime into spherical volume undulation in Euclidean geometry and calculates
the probability density of an electron within the sphere from the classical
perspective. From the primary wave function of a 1s electron, the author also
tries to derive the mathematical expression of central force that guides the
surrounding bodies along the orbits. The result is exciting and surprising that
questions the exactness of the venerable Coulomb's law.


title: Comparison of coherence times in three dc SQUID phase qubits

abstract:
  We report measurements of spectroscopic linewidth and Rabi oscillations in
three thin-film dc SQUID phase qubits. One device had a single-turn Al loop,
the second had a 6-turn Nb loop, and the third was a first order gradiometer
formed from 6-turn wound and counter-wound Nb coils to provide isolation from
spatially uniform flux noise. In the 6 - 7.2 GHz range, the spectroscopic
coherence times for the gradiometer varied from 4 ns to 8 ns, about the same as
for the other devices (4 to 10 ns). The time constant for decay of Rabi
oscillations was significantly longer in the single-turn Al device (20 to 30
ns) than either of the Nb devices (10 to 15 ns). These results imply that
spatially uniform flux noise is not the main source of decoherence or
inhomogenous broadening in these devices.


title: Pointwise convergence for semigroups in vector-valued $L^p$ spaces

abstract:
  Suppose that T_t is a symmetric diffusion semigroup on L^2(X) and consider
its tensor product extension to the Bochner space L^p(X,B), where B belongs to
a certain broad class of UMD spaces. We prove a vector-valued version of the
Hopf--Dunford--Schwartz ergodic theorem and show that this extends to a maximal
theorem for analytic continuations of the semigroup's extension to L^p(X,B). As
an application, we show that such continuations exhibit pointwise convergence.


title:
The Age, Metallicity and Alpha-Element Abundance of Galactic Globular
  Clusters from Single Stellar Population Models

abstract:
  Establishing the reliability with which stellar population parameters can be
measured is vital to extragalactic astronomy. Galactic GCs provide an excellent
medium in which to test the consistency of Single Stellar Population (SSP)
models as they should be our best analogue to a homogeneous (single) stellar
population. Here we present age, metallicity and $\alpha$-element abundance
measurements for 48 Galactic globular clusters (GCs) as determined from
integrated spectra using Lick indices and SSP models from Thomas, Maraston &
Korn, Lee & Worthey and Vazdekis et al. By comparing our new measurements to
independent determinations we are able to assess the ability of these SSPs to
derive consistent results -- a key requirement before application to
heterogeneous stellar populations like galaxies.
  We find that metallicity determinations are extremely robust, showing good
agreement for all models examined here, including a range of enhancement
methods. Ages and $\alpha$-element abundances are accurate for a subset of our
models, with the caveat that the range of these parameters in Galactic GCs is
limited. We are able to show that the application of published Lick index
response functions to models with fixed abundance ratios allows us to measure
reasonable $\alpha$-element abundances from a variety of models. We also
examine the age-metallicity and [$\alpha$/Fe]-metallicity relations predicted
by SSP models, and characterise the possible effects of varied model horizontal
branch morphology on our overall results.


title:
The r-process of stellar nucleosynthesis: Astrophysics and nuclear
  physics achievements and mysteries

abstract:
  The r-process, or the rapid neutron-capture process, of stellar
nucleosynthesis is called for to explain the production of the stable (and some
long-lived radioactive) neutron-rich nuclides heavier than iron that are
observed in stars of various metallicities, as well as in the solar system.
  A very large amount of nuclear information is necessary in order to model the
r-process. This concerns the static characteristics of a large variety of light
to heavy nuclei between the valley of stability and the vicinity of the
neutron-drip line, as well as their beta-decay branches or their reactivity.
The enormously challenging experimental and theoretical task imposed by all
these requirements is reviewed, and the state-of-the-art development in the
field is presented. Nuclear-physics-based and astrophysics-free r-process
models of different levels of sophistication have been constructed over the
years. We review their merits and their shortcomings. For long, the core
collapse supernova of massive stars has been envisioned as the privileged
r-process location. We present a brief summary of the one- or multidimensional
spherical or non-spherical explosion simulations available to-date. Their
predictions are confronted with the requirements imposed to obtain an
r-process. The possibility of r-nuclide synthesis during the decompression of
the matter of neutron stars following their merging is also discussed.


title: Pair correlated atoms with a twist

abstract:
  We present an analysis of the quantum state resulting from the dissociation
of diatomic molecules prepared in a condensate vortex state. The many-body
state preserves the rotational symmetry of the system in quantum correlated
states by having two equally populated components with angular momentum adding
to unity. A simple two-mode analysis and a full quantum field analysis is
presented for the case of non-interacting atoms and weak depletion of the
molecular condensate.


title: Hagedorn Strings and Correspondence Principle in AdS(3)

abstract:
  Motivated by the possibility of formulating a strings/black hole
correspondence in AdS space, we extract the Hagedorn behavior of thermal AdS_3
bosonic string from 1-loop partition function of SL(2,R) WZW model. We find
that the Hagedorn temperature is monotonically increasing as the AdS radius
shrinks, reaches a maximum of order of string scale set by the unitarity bound
of the CFT for internal space. The resulting density of states near the
Hagedorn temperature resembles the form as for strings in flat space and is
dominated by the space-like long string configurations. We then argue a
conjectured strings/black hole correspondence in AdS space by applying the
Hagedorn thermodynamics. We find the size of the corresponding black hole is a
function of the AdS radius. For large AdS radius a black hole far bigger than
the string scale will form. On the contrary, when the AdS and string scales are
comparable a string size black hole will form. We also examine strings on BTZ
background obtained through SL(2,Z) transformation. We find a tachyonic
divergence for a BTZ black hole of string scale size.


title: Stable real algebraic vector bundles over a Klein bottle

abstract:
  Let X be a geometrically connected smooth projective curve of genus one,
defined over the field of real numbers, such that X does not have any real
points. We classify the isomorphism classes of all stable real algebraic vector
bundles over X.


title:
Multiple solutions to the likelihood equations in the Behrens-Fisher
  problem

abstract:
  The Behrens-Fisher problem concerns testing the equality of the means of two
normal populations with possibly different variances. The null hypothesis in
this problem induces a statistical model for which the likelihood function may
have more than one local maximum. We show that such multimodality contradicts
the null hypothesis in the sense that if this hypothesis is true then the
probability of multimodality converges to zero when both sample sizes tend to
infinity. Additional results include a finite-sample bound on the probability
of multimodality under the null and asymptotics for the probability of
multimodality under the alternative.


title:
On the perturbation of the electromagnetic energy due to the presence of
  inhomogeneities with small diameters

abstract:
  We consider solutions to the time-harmonic Maxwell problem in $\R^3$. For
such solution we provide a rigorous derivation of the asymptotic expansions in
the practically interesting situation, where a finite number of inhomogeneities
of small diameter are imbedded in the entire space. Then, we describe the
behavior of the electromagnetic energy caused by the presence of these
inhomogeneities.


title:
Third-order non-Coulomb correction to the S-wave quarkonium wave
  functions at the origin

abstract:
  We compute the third-order correction to the S-wave quarkonium wave functions
|\psi_n(0)|^2 at the origin from non-Coulomb potentials in the effective
non-relativistic Lagrangian. Together with previous results on the Coulomb
correction and the ultrasoft correction computed in a companion paper, this
completes the third-order calculation up to a few unknown matching
coefficients. Numerical estimates of the new correction for bottomonium and
toponium are given.


title: The Orthopositronium Problem and e-\mu-\tau-Universality

abstract:
  The quantitative description of the orthopositronium anomalies ("isotope
anomaly" in a gaseous neon for the "resonance conditions" and
"lambda{T}-anomaly" in non-resonance conditions) is possible on the basis of a
hypothesis about restoration of spontaneously broken complete relativity
(A.F.Andreev, 1982) of the limited space-time "volume" ("defect" of the
space-time) in a final state of the beta{+}-decay of nucleus such as Na-22,
Ga-68, etc. This addition of the Standard Model in a final state of the
topological quantum transition (non-steady-state, a generalized displacement
current) supposes the description on the common basis timelike fundamental
particles (locality) and spacelike fundamental structure (non-locality without
causal paradoxes). One of achievements of expansion of Standard Model can be a
substantiation of topological connection e-mu-tau-Universality with discrete
structure (quantization) "defect" of the space-time.


title:
Nonresonant entrainment of detuned oscillators induced by common
  external noise

abstract:
  We have found that a novel type of entrainment occurs in two nonidentical
limit cycle oscillators subjected to a common external white Gaussian noise.
This entrainment is anomalous in the sense that the two oscillators have
different mean frequencies, where the difference is constant as the noise
intensity increases, but their phases come to be locked for almost all the
time. We present a theory and numerical evidence for this phenomenon.


title: Radiative Losses in Plasma Accelerators

abstract:
  We investigate the dynamics of a relativistic electron in a strongly
nonlinear plasma wave in terms of classical mechanics by taking into account
the action of the radiative reaction force. The two limiting cases are
considered. In the first case where the energy of the accelerated electrons is
low, the electron makes many betatron oscillations during the acceleration. In
the second case where the energy of the accelerated electrons is high, the
betatron oscillation period is longer than the electron residence time in the
accelerating phase. We show that the force of radiative friction can severely
limit the rate of electron acceleration in a plasma accelerator.


title:
Practical effects in the preparation of cluster states using weak
  non-linearities

abstract:
  We discuss experimental effects in the implementation of a recent scheme for
performing bus mediated entangling operations between qubits. Here a bus mode,
a strong coherent state, successively undergoes weak Kerr-type non-linear
interactions with qubits. A quadrature measurement on the bus then projects the
qubits into an entangled state. This approach has the benefit that entangling
gates are non-destructive, may be performed non-locally, and there is no need
for efficient single photon detection. In this paper we examine practical
issues affecting its experimental implementation. In particular, we analyze the
effects of post-selection errors, qubit loss, bus loss, mismatched coupling
rates and mode-mismatch. We derive error models for these effects and relate
them to realistic fault-tolerant thresholds, providing insight into realistic
experimental requirements.


title: Anomaly in Symplectic Integrator

abstract:
  Effective Liouville operators of the first- and the second-order symplectic
integrators are obtained for the one-dimensional harmonic-oscillator system.
The operators are defined only when the time step is less than two. Absolute
values of the coordinate and the momentum monotonically increase for large time
steps.


title: Patience Sorting and Its Generalizations

abstract:
  This dissertation collects together results on Patience Sorting and its
generalizations. It incorporates the results of math.CO/0506358,
math.CO/0507031, and math.CO/0512122, as well as previously unpublished
results.


title: Baryons and Mesons with Beauty

abstract:
  Recent experimental findings of several mesons and baryons with "beauty" and
"charm" as flavors remind us of the days when strangeness was discovered, and
how its inclusion led to SU(3)-flavor symmetry with enormous success in the
classification of the "proliferated" states into SU(3) multiplets. One of the
key elements was the successful application of the first order perturbation in
symmetry breaking, albeit what then appeared to be huge mass differences, and
the prediction of new states that were confirmed by experiments. In this note,
we venture into the past and, applying the same techniques, predict some new
"beauty-" and "charm-" flavored hadrons. If these new states are confirmed
experimentally, it may provide a useful phenomenological model for classifying
numerous states that are found to be in the PDG data and could invite further
theoretical challenges towards our understanding of symmetry breaking.


title: Collapse of the N=28 shell closure in $^{42}$Si

abstract:
  The energies of the excited states in very neutron-rich $^{42}$Si and
$^{41,43}$P have been measured using in-beam $\gamma$-ray spectroscopy from the
fragmentation of secondary beams of $^{42,44}$S at 39 A.MeV. The low 2$^+$
energy of $^{42}$Si, 770(19) keV, together with the level schemes of
$^{41,43}$P provide evidence for the disappearance of the Z=14 and N=28
spherical shell closures, which is ascribed mainly to the action of
proton-neutron tensor forces. New shell model calculations indicate that
$^{42}$Si is best described as a well deformed oblate rotor.


title:
Unification of Laughlin and Moore-Read States in SUSY Quantum Hall
  Effect

abstract:
  Based on the recently proposed SUSY quantum Hall effect, we show that
Laughlin and Moore-Read states are related by a hidden SUSY transformation.
Regarding the SUSY Laughlin wavefunction as a master wavefunction, Laughlin and
Moore-Read states appear as two extreme limits of component wavefunctions.
Realizations of topological excitations on Laughlin and Moore-Read states are
also discussed in the SUSY formalism. We develop a streographically projected
formulation of the SUSY quantum Hall effect. With appropriate interpretation of
Grassmann odd coordinates, we illustrate striking analogies between SUSY
quantum Hall effect and superfluidity.


title: Forward analysis of $\pi$N scattering with an expansion method

abstract:
  The $\pi$N forward scattering data are analyzed using an expansion method,
where the invariant amplitudes are represented by expansions satisfying the
forward dispersion relations. The experimental errors of the data are taken
into account through the covariance matrix of the coefficients of the
expansions in a careful error analysis. From the results, some coefficients,
$c_{n0}^\pm$, of the subthreshold expansions have been calculated with proper
error bars.


title:
Domains of definition of Monge-Amp\`ere operators on compact K\"ahler
  manifolds

abstract:
  Let $(X,\omega)$ be a compact K\"ahler manifold. We introduce and study the
largest set $DMA(X,\omega)$ of $\omega$-plurisubharmonic (psh) functions on
which the complex Monge-Amp\`ere operator is well defined. It is much larger
than the corresponding local domain of definition, though still a proper subset
of the set $PSH(X,\om)$ of all $\om$-psh functions. We prove that certain
twisted Monge-Amp\`ere operators are well defined for all $\omega$-psh
functions. As a consequence, any $\om$-psh function with slightly attenuated
singularities has finite weighted Monge-Amp\`ere energy.


title: The Length of a Shortest Geodesic Loop

abstract:
  We give a lower bound for the length of a non-trivial geodesic loop on a
simply-connected and compact manifold of even dimension with a non-reversible
Finsler metric of positive flag curvature. Harris and Paternain use this
estimate in their recent paper [HP] to give a geometric characterization of
dynamically convex Finsler metrics on the 2-sphere.


title: Attractors for gradient flows of non convex functionals and applications

abstract:
  This paper addresses the long-time behavior of gradient flows of non convex
functionals in Hilbert spaces. Exploiting the notion of generalized semiflows
by J. M. Ball, we provide some sufficient conditions for the existence of a
global attractor. The abstract results are applied to various classes of non
convex evolution problems. In particular, we discuss the long-time behavior of
solutions of quasi-stationary phase field models and prove the existence of a
global attractor.


title: L-infinity Algebras and Deformations of Holomorphic Maps

abstract:
  We construct the deformation functor associated with a pair of morphisms of
differential graded Lie algebras, and use it to study infinitesimal
deformations of holomorphic maps of compact complex manifolds. In particular,
using L-infinity structures, we give an explicit description of the
differential graded Lie algebra that controls this problem.


title:
Quantum field propagator for extended-objects in the microcanonical
  ensemble and the S-matrix formulation

abstract:
  Starting with the well-known Nambu-Goto action for an N-extended body system
the propagator in the microcanonical ensemble is explicitly computed. This
propagator is independent of the temperature and, in contrast with the previous
references, takes account on all the non-local effects produced by the extended
objects (e.g., strings) in interaction. The relation between relativistic
quantum field theories in the microcanonical approach and the pure S-matrix
formulation is stablished and analyzed.


title:
Pattern theorems, ratio limit theorems and Gumbel maximal clusters for
  random fields

abstract:
  We study occurrences of patterns on clusters of size n in random fields on
Z^d. We prove that for a given pattern, there is a constant a>0 such that the
probability that this pattern occurs at most an times on a cluster of size n is
exponentially small. Moreover, for random fields obeying a certain Markov
property, we show that the ratio between the numbers of occurrences of two
distinct patterns on a cluster is concentrated around a constant value. This
leads to an elegant and simple proof of the ratio limit theorem for these
random fields, which states that the ratio of the probabilities that the
cluster of the origin has sizes n+1 and n converges as n tends to infinity.
Implications for the maximal cluster in a finite box are discussed.


abstract:
  We prove formulas for the generating functions for M_2-rank differences for
partitions without repeated odd parts. These formulas are in terms of modular
forms and generalized Lambert series.


title: Refined bound for sum-free sets in groups of prime order

abstract:
  Improving upon earlier results of Freiman and the present authors, we show
that if $p$ is a sufficiently large prime and $A$ is a sum-free subset of the
group of order $p$, such that $n:=|A|>0.318p$, then $A$ is contained in a
dilation of the interval $[n,p-n]\pmod p$.


title: Correlation Effects in Side-Coupled Quantum Dots

abstract:
  Using Wilson's numerical renormalization group (NRG) technique we compute
zero-bias conductance and various correlation functions of a double quantum dot
(DQD) system. We present different regimes within a phase diagram of the DQD
system. By introducing a negative Hubbard U on one of the quantum dots, we
simulate the effect of electron-phonon coupling and explore the properties of
the coexisting spin and charge Kondo state. In a triple quantum dot (TQD)
system a multi-stage Kondo effect appears where localized moments on quantum
dots are screened successively at exponentially distinct Kondo temperatures.


title:
Insulating state and the importance of the spin-orbit coupling in
  Ca$_3$CoRhO$_6$

abstract:
  We have carried out a comparative theoretical study of the electronic
structure of the novel one-dimensional Ca$_3$CoRhO$_6$ and Ca$_3$FeRhO$_6$
systems. The insulating antiferromagnetic state for the Ca$_3$FeRhO$_6$ can be
well explained by band structure calculations with the closed shell high-spin
$d^5$ (Fe$^{3+}$) and low-spin $t_{2g}^{6}$ (Rh$^{3+}$) configurations. We
found for the Ca$_3$CoRhO$_6$ that the Co has a strong tendency to be $d^7$
(Co$^{2+}$) rather than $d^6$ (Co$^{3+}$), and that there is an orbital
degeneracy in the local Co electronic structure. We argue that it is the
spin-orbit coupling which will lift this degeneracy thereby enabling local spin
density approximation + Hubbard U (LSDA+U) band structure calculations to
generate the band gap. We predict that the orbital contribution to the magnetic
moment in Ca$_3$CoRhO$_6$ is substantial, i.e. significantly larger than 1
$\mu_B$ per formula unit. Moreover, we propose a model for the contrasting
intra-chain magnetism in both materials.


title:
Classification of quasifinite representations with nonzero central
  charges for type $A_1$ EALA with coordinates in quantum torus

abstract:
  In this paper, we first construct a Lie algebra $L$ from rank 3 quantum
torus, and show that it is isomorphic to the core of EALAs of type $A_1$ with
coordinates in rank 2 quantum torus. Then we construct two classes of
irreducible ${\bf Z}$-graded highest weight representations, and give the
necessary and sufficient conditions for these representations to be
quasifinite. Next, we prove that they exhaust all the generalized highest
weight irreducible ${\bf Z}$-graded quasifinite representations. As a
consequence, we determine all the irreducible ${\bf Z}$-graded quasifinite
representations with nonzero central charges. Finally, we construct two classes
of highest weight ${\bf Z}^2$-graded quasifinite representations by using these
${\bf Z}$-graded modules.


title:
Coupled Painlev\'e systems with affine Weyl group symmetry of types
  $D_3^{(2)}$ and $D_5^{(2)}$

abstract:
  In this paper, we find a two-parameter family of coupled Painlev\'e systems
in dimension four with affine Weyl group symmetry of type $D_3^{(2)}$. We also
find a four-parameter family of 2-coupled $D_3^{(2)}$-systems in dimension
eight with affine Weyl group symmetry of type $D_5^{(2)}$. We show that for
each system, we give its symmetry and holomorphy conditions, respectively.
These symmetries, holomorphy conditions and invariant divisors are new.


title: Cosmic rays and the primordial gas

abstract:
  One of the most outstanding problems in the gravitational collapse scenario
of early structure formation is the cooling of primordial gas to allow for
small mass objects to form. As the neutral primordial gas is a poor radiator at
temperatures (T\le10^4\unit{K}), molecular hydrogen is needed for further
cooling down to temperatures (T\sim100\unit{K}). The formation of molecular
hydrogen is catalyzed by the presence of free electrons, which could be
provided by the ionization due to an early population of cosmic rays. In order
to investigate this possibility we developed a code to study the effects of
ionizing cosmic rays on the thermal and chemical evolution of primordial gas.
We found that cosmic rays can provide enough free electrons needed for the
formation of molecular hydrogen, and therefore can increase the cooling ability
of such primordial gas under following conditions: A dissociating photon flux
with (F<10^{-18}\unit{erg cm^{-2} Hz^{-1} s^{-1}}), initial temperature of the
gas (\sim10^{3}\unit{K}), total gas number densities (n\ge1\unit{cm^{-3}}),
Cosmic ray sources with (\dot{\epsilon}_{CR}>10^{-33}\unit{erg cm^{-3}
s^{-1}}).


title: B \to K(K^*) missing energy in Unparticle physics

abstract:
  In the present work we study the effects of an unparticle $\unpart$ as the
possible source of missing energy in the decay $B \to K (K^*) + {\rm missing
energy}$. We find that the dependence of the differential branching ratio on
the $K$($K^*$)-meson's energy in the presence of the vector unparticle
operators is very distinctive from that of the SM. Moreover, in using the
existing upper bound on $B \to K (K^*) + {\rm missing energy}$ decays, we have
been able to put more stringent constraints on the parameters of unparticle
stuff.


title: Constraining the Geometry of the Neutron Star RX J1856.5-3754

abstract:
  RX J1856.5-3754 is one of the brightest, nearby isolated neutron stars, and
considerable observational resources have been devoted to its study. In
previous work, we found that our latest models of a magnetic, hydrogen
atmosphere matches well the entire spectrum, from X-rays to optical (with
best-fitting neutron star radius R=14 km, gravitational redshift z_g~0.2, and
magnetic field B~4x10^12 G). A remaining puzzle is the non-detection of
rotational modulation of the X-ray emission, despite extensive searches. The
situation changed recently with XMM-Newton observations that uncovered 7 s
pulsations at the 1% level. By comparing the predictions of our model (which
includes simple dipolar-like surface distributions of magnetic field and
temperature) with the observed brightness variations, we are able to constrain
the geometry of RX J1856.5-3754, with one angle < 6 deg and the other angle =
20-45 deg, though the solutions are not definitive given the observational and
model uncertainties. These angles indicate a close alignment between the
rotation and magnetic axes or between the rotation axis and the observer. We
discuss our results in the context of RX J1856.5-3754 being a normal radio
pulsar and a candidate for observation by future X-ray polarization missions
such as Constellation-X or XEUS.


title:
Versatile compact atomic source for high resolution dual atom
  interferometry

abstract:
  We present a compact $^{87}$Rb atomic source for high precision dual atom
interferometers. The source is based on a double-stage magneto-optical trap
(MOT) design, consisting of a 2-dimensional (2D)-MOT for efficient loading of a
3D-MOT. The accumulated atoms are precisely launched in a horizontal moving
molasses. Our setup generates a high atomic flux ($>10^{10}$ atoms/s) with
precise and flexibly tunable atomic trajectories as required for high
resolution Sagnac atom interferometry. We characterize the performance of the
source with respect to the relevant parameters of the launched atoms, i.e.
temperature, absolute velocity and pointing, by utilizing time-of-flight
techniques and velocity selective Raman transitions.


title: The diffeomorphism group of a K3 surface and Nielsen realization

abstract:
  The Nielsen Realization problem asks when the group homomorphism from Diff(M)
to pi_0 Diff(M) admits a section. For M a closed surface, Kerckhoff proved that
a section exists over any finite subgroup, but Morita proved that if the genus
is large enough then no section exists over the entire mapping class group. We
prove the first nonexistence theorem of this type in dimension 4: if M is a
smooth closed oriented 4-manifold which contains a K3 surface as a connected
summand then no section exists over the whole of the mapping class group. This
is done by showing that certain obstructions lying in the rational cohomology
of B(pi_0 Diff(M)) are nonzero. We detect these classes by showing that they
are nonzero when pulled back to the moduli space of Einstein metrics on a K3
surface.


title: Skew Divided Difference Operators and Schubert Polynomials

abstract:
  We study an action of the skew divided difference operators on the Schubert
polynomials and give an explicit formula for structural constants for the
Schubert polynomials in terms of certain weighted paths in the Bruhat order on
the symmetric group. We also prove that, under certain assumptions, the skew
divided difference operators transform the Schubert polynomials into
polynomials with positive integer coefficients.


title: Possibility of large lifetime differences in neutral B meson systems

abstract:
  We investigate new physics models that can increase the lifetime differences
in the $B_q$--$\bar{B}_q$ systems ($q = d,s$) above their standard model
values. If both $B_q$ as well as $\bar{B}_q$ can decay to a final state through
flavour dependent new physics interactions, the so-called Grossman bound may be
evaded. As examples, we consider the scalar leptoquark model and
$\lambda''$-type R-parity violating supersymmetry. We find that models with a
scalar leptoquark can enhance $\Delta\Gamma_s/\Gamma_s$ all the way up to its
experimental upper bound and $\Delta\Gamma_d/\Gamma_d$ to as much as $\sim
2.5%$, at the same time allowing the CP violating phase $\beta_s$ to vary
between $- 45^\circ$ and $20^\circ$. R-parity violating supersymmetry models
cannot enhance the lifetime differences significantly, but can enhance the
value of $\beta_s$ up to $\sim \pm 20^\circ$. This may bring the values of
$\Delta\Gamma_q/\Gamma_q$ as well as $\beta_s$ within the measurement
capabilities of $B$ factories and LHCb. We also obtain bounds on combinations
of these new physics couplings, and predict enhanced branching ratios of
$B_{s/d} \to \tau^+ \tau^-$.


title: A permanent formula for the Jones polynomial

abstract:
  The permanent of a square matrix is defined in a way similar to the
determinant, but without using signs. The exact computation of the permanent is
hard, but there are Monte-Carlo algorithms that can estimate general
permanents. Given a planar diagram of a link L with $n$ crossings, we define a
7n by 7n matrix whose permanent equals to the Jones polynomial of L. This
result accompanied with recent work of Freedman, Kitaev, Larson and Wang
provides a Monte-Carlo algorithm to any decision problem belonging to the class
BQP, i.e. such that it can be computed with bounded error in polynomial time
using quantum resources.


title:
Quantum-theoretical description of the cosmological constant as the
  zero-point energy

abstract:
  The present paper seeks to construct a quantum theory of the cosmological
constant in which its presently observed very small value emerges naturally.


title: Criticality of a classical dimer model on the triangular lattice

abstract:
  We consider a classical interacting dimer model which interpolates between
the square lattice case and the triangular lattice case by tuning a chemical
potential in the diagonal bonds. The interaction energy simply corresponds to
the number of plaquettes with parallel dimers. Using transfer matrix
calculations, we find in the anisotropic triangular case a succession of
different physical phases as the interaction strength is increased: a short
range disordered liquid dimer phase at low interactions, then a critical phase
similar to the one found for the square lattice, and finally a transition to an
ordered columnar phase for large interactions. The existence of the critical
phase is in contrast with the belief that criticality for dimer models is
ascribed to bipartiteness. For the isotropic triangular case, we have
indications that the system undergoes a first order phase transition to an
ordered phase, without appearance of an intermediate critical phase.


title: Site Percolation on Planar $\Phi^{3}$ Random Graphs

abstract:
  In this paper, site percolation on random $\Phi^{3}$ planar graphs is studied
by Monte-Carlo numerical techniques. The method consists in randomly removing a
fraction $q=1-p$ of vertices from graphs generated by Monte-Carlo simulations,
where $p$ is the occupation probability. The resulting graphs are made of
clusters of occupied sites. By measuring several properties of their
distribution, it is shown that percolation occurs for an occupation probability
above a percolation threshold $p_{c}$=0.7360(5). Moreover, critical exponents
are compatible with those analytically known for bond percolation.


title: Tunneling into strongly biased Tomonaga-Luttinger liquid

abstract:
  We calculate the tunneling density of states for a Tomonaga-Luttinger liquid
placed under a strong bias voltage. For the tunneling through a side-coupled
point contact, one can observe the power law singularities in the tunneling
density of states separately for the right- and left-movers despite the
point-like tunnel contact. Deviations of the nonequilibrium tunneling exponents
from the equilibrium case are discussed.


title:
On the Vanishing and the Finiteness of Supports of Generalized Local
  Cohomology Modules

abstract:
  Let $(R,\fr m)$ be a Noetherian local ring, $I$ an ideal of $R$ and $M, N$
two finitely generated $R$-modules. The first result of this paper is to prove
a vanishing theorem for generalized local cohomology modules which says that
$H^j_I(M,N)=0$ for all $j>\dim(R)$, provided $M$ is of finite projective
dimension. Next, we study and give characterizations for the least and the last
integer $r$ such that $\Supp(H^r_I(M,N))$ is infinite.


title: On The Stability of Non-Supersymmetric Attractors in String Theory

abstract:
  We study non-supersymmetric attractors obtained in Type IIA compactifications
on Calabi Yau manifolds. Determining if an attractor is stable or unstable
requires an algebraically complicated analysis in general. We show using group
theoretic techniques that this analysis can be considerably simplified and can
be reduced to solving a simple example like the STU model. For attractors with
D0-D4 brane charges, determining stability requires expanding the effective
potential to quartic order in the massless fields. We obtain the full set of
these terms. For attractors with D0-D6 brane charges, we find that there is a
moduli space of solutions and the resulting attractors are stable. Our analysis
is restricted to the two derivative action.


title:
Lowest-energy structures of 13-atom binary clusters: Do icosahedral
  clusters exist in binary liquid alloys?

abstract:
  Although the existence of 13-atom icosahedral clusters in one-component
close-packed undercooled liquids was predicted more than half a century ago by
Frank, the existence of such icosahedral clusters is less clear in liquid
alloys. We study the lowest-energy structures of 13-atom AxB13-x Lennard-Jones
binary clusters using the modified space-fixed genetic algorithm and the
artificial Lennard-Jones potential designed by Kob and Andersen. Curiously, the
lowest-energy structures are non-icosahedral for almost all compositions. The
role played by the icosahedral cluster in a binary glass is questionable.


title: Quantization of symplectic vector spaces over finite fields

abstract:
  In this paper, we construct a quantization functor, associating a complex
vector space H(V) to a finite dimensional symplectic vector space V over a
finite field of odd characteristic. As a result, we obtain a canonical model
for the Weil representation of the symplectic group Sp(V). The main new
technical result is a proof of a stronger form of the Stone-von Neumann
property for the Heisenberg group. Our result answers, for the case of the
Heisenberg group, a question of Kazhdan about the possible existence of a
canonical vector space attached to a coadjoint orbit of a general unipotent
group over finite field.

categories: math.RT math-ph math.AG math.MP math.QA math.SG quant-ph


title:
TRUFAS, a wavelet based algorithm for the rapid detection of planetary
  transits

abstract:
  Aims: We describe a fast, robust and automatic detection algorithm, TRUFAS,
and apply it to data that are being expected from the CoRoT mission. Methods:
The procedure proposed for the detection of planetary transits in light curves
works in two steps: 1) a continuous wavelet transformation of the detrended
light curve with posterior selection of the optimum scale for transit
detection, and 2) a period search in that selected wavelet transformation. The
detrending of the light curves are based on Fourier filtering or a discrete
wavelet transformation. TRUFAS requires the presence of at least 3 transit
events in the data. Results: The proposed algorithm is shown to identify
reliably and quickly the transits that had been included in a standard set of
999 light curves that simulate CoRoT data. Variations in the pre-processing of
the light curves and in the selection of the scale of the wavelet transform
have only little effect on TRUFAS' results. Conclusions: TRUFAS is a robust and
quick transit detection algorithm, especially well suited for the analysis of
very large volumes of data from space or ground-based experiments, with long
enough durations for the target-planets to produce multiple transit events.


title: Almost-free finite covers

abstract:
  Finite covers are a technique for building new structures from simpler ones.
The original motivation to study finite covers is in the Ladder theorem of
Zilber which describes how totally categorical structures are built from
strictly minimal sets by a sequence of covers.
  Let W be a first-order structure and r be an Aut(W)-congruence on W. In this
paper we define the almost-free finite covers of W with respect to r, and we
show how to construct them. These are a generalization of free finite covers. A
consequence of a result of Evans and Hrushovski in the paper "On the
automorphism groups of finite covers" is that any finite cover of W with
binding groups all equal to a simple non-abelian permutation group is
almost-free with respect to some r on W. Our main result gives a description
(up to isomorphism) in terms of the Aut(W)-congruences on W of the kernels of
principal finite covers of W with bindings groups equal at any point to a
simple non-abelian regular permutation group G. Then we analyze almost-free
finite covers of the set of ordered n-tuples of distinct elements from a
countable set Omega, regarded as a structure with automorphism group equal to
the Sym(Omega) and we show a result of biinterpretability.


title: The golden ratio prediction for the solar neutrino mixing

abstract:
  We present a simple texture that predicts the cotangent of the solar neutrino
mixing angle to be equal to the golden ratio. This prediction is 1.4 standard
deviations below the present best-fit value and final SNO and KamLAND data
could discriminate it from tri-bi-maximal mixing. The neutrino mass matrix is
invariant under a Z_2 x Z'_2 symmetry: that geometrically is a reflection along
the diagonal of the golden rectangle. Assuming an analogous structure in the
quark sector suggests a golden prediction for the Cabibbo angle, theta_C =
pi/4- theta_12 = 13.3 degree, up to uncertainties comparable to V_{ub}.


title: A Near-Infrared Stellar Spectral Library: II. K-Band Spectra

abstract:
  This paper is the second in the series of papers on near-infrared (NIR)
stellar spectral library produced by reducing the observations carried out with
1.2 meter Gurushikhar Infrared Telescope (GIRT), at Mt. Abu, India using a
NICMOS3 HgCdTe 256 X 256 NIR array based spectrometer. In paper I (Ranade et
al. 2004), H-band spectra of 135 stars at a resolution of ~16 Ang were
presented. The K-band library being released now consists of 114 stars covering
spectral types O7--M7 and luminosity classes I--V. The spectra have a moderate
resolution of ~22 Ang in the K band and have been continuum shape corrected to
their respective effective temperatures. We hope to release the remaining
J-band spectra soon. The complete H and K-Band library is available online at:
http://vo.iucaa.ernet.in/~voi/NIR_Header.html


title: The Pseudospectrum of Systems of Semiclassical Operators

abstract:
  The pseudospectra (or spectral instability) of non-selfadjoint operators is a
topic of current interest in applied mathematics. In fact, for non-selfadjoint
operators the resolvent could be very large outside the spectrum, making the
numerical computation of the complex eigenvalues very hard. This has
importance, for example, in quantum mechanics, random matrix theory and fluid
dynamics.
  The occurence of pseudospectra for non-selfadjoint semiclassical differential
operators is due to the existence of quasimodes, i.e., approximate local
solutions to the eigenvalue problem. For scalar operators, the quasimodes
appear since the bracket condition is not satisfied for topological reasons,
see the paper by Dencker, Sjostrand and Zworski in Comm. Pure Appl. Math. 57
(2004), 384-415.
  In this paper we shall investigate how these result can be generalized to
square systems of semiclassical differential operators of principal type. These
are the systems whose principal symbol vanishes of first order on its kernel.
We show that the resolvent blows up as in the scalar case, except in a nowhere
dense set of degenerate values. We also define quasi-symmetrizable systems and
systems of subelliptic type for which we prove estimates on the resolvent.


title: The Last Scientific Revolution

abstract:
  Critically growing problems of fundamental science organisation and content
are analysed with examples from physics and emerging interdisciplinary fields.
Their origin is specified and new science structure (organisation and content)
is proposed as a unified solution.


title: Kalman Filtering in the Presence of State Space Equality Constraints

abstract:
  We discuss two separate techniques for Kalman Filtering in the presence of
state space equality constraints. We then prove that despite the lack of
similarity in their formulations, under certain conditions, the two methods
result in mathematically equivalent constrained estimate structures. We
conclude that the potential benefits of using equality constraints in Kalman
Filtering often outweigh the computational costs, and as such, equality
constraints, when present, should be enforced by way of one of these two
methods.


title: Boundary behaviour of Loewner Chains

abstract:
  In paper found conditions that guarantee that solution of Loewner-Kufarev
equation maps unit disc onto domain with quasiconformal rectifiable boundary,
or it has continuation on closed unit disc, or it's inverse function has
continuation on closure of domain.


title:
Renormalization of NN Interaction with Relativistic Chiral Two Pion
  Exchange

abstract:
  The renormalization of the NN interaction with the Chiral Two Pion Exchange
Potential computed using relativistic baryon chiral perturbation theory is
considered. The short distance singularity reduces the number of counter-terms
to about a half as those in the heavy-baryon expansion. Phase shifts and
deuteron properties are evaluated and a general overall agreement is observed.


title:
Loop corrections for message passing algorithms in continuous variable
  models

abstract:
  In this paper we derive the equations for Loop Corrected Belief Propagation
on a continuous variable Gaussian model. Using the exactness of the averages
for belief propagation for Gaussian models, a different way of obtaining the
covariances is found, based on Belief Propagation on cavity graphs. We discuss
the relation of this loop correction algorithm to Expectation Propagation
algorithms for the case in which the model is no longer Gaussian, but slightly
perturbed by nonlinear terms.


title:
Chiral loop corrections to weak decays of B mesons to positive and
  negative parity charmed mesons

abstract:
  We determine chiral loop corrections to the B meson decay amplitudes to
positive and negative parity charmed mesons within a framework which combines
heavy quark and chiral symmetries. Then we investigate the impact of the
lowest-lying positive parity heavy mesons on the determination of the
Isgur-Wise functions. The corrections due to these states are competitive with
the contributions arising from K and eta meson loops. Since lattice studies
rely on the chiral behavior of the amplitudes we discuss the chiral limit of
our results. We find that the determination of the slope at zero recoil of the
Isgur-Wise function xi for the B transition to negative parity charm mesons is
moderately affected by the inclusion of new states, while the slope of
tau_{1/2} is affected significantly more.


title: Echoes from the companion star in Sco X-1

abstract:
  We present simultaneous X-ray (RXTE) and optical (ULTRACAM) narrow band
(Bowen blend/HeII and nearby continuum) observations of Sco X-1 at 2-10 Hz time
resolution. We find that the Bowen/HeII emission lags the X-ray light-curves
with a light travel time of ~11-16s which is consistent with reprocessing in
the companion star. The echo from the donor is detected at orbital phase ~0.5
when Sco X-1 is at the top of the Flaring Branch. Evidence of echoes is also
seen at the bottom of the Flaring Branch but with time-lags of 5-10s which are
consistent with reprocessing in an accretion disc with a radial temperature
profile. We discuss the implication of our results for the orbital parameters
of Sco X-1.


title: Gauge-Higgs unification with broken flavor symmetry

abstract:
  We study Gauge-Higgs unification model on the orbifold $S^{1}/Z_{2}$ based on
the extended SM gauge group $G_{SM}^{ex}=SU(2)_{L} \times U(1)_{Y} \times
SO(3)_{F}$. The group $SO(3)_{F}$ is treated as a chiral gauged flavour
symmetry. Electroweak-, flavour- and Higgs interactions are unified in one
single gauge group SU(7) which is broken again down to $G_{SM}^{ex}$ by
orbifolding and imposing additional boundary conditions. The compactification
scale is O(1) TeV. The orbifold $S^{1}/Z_{2}$ is put on a lattice. This setting
gives a staring point for RG-transformations. As a result the bulk is
integrated out and the extra dimension consist of only two points: the orbifold
fixed points. Parallel transporters (PT) in the extra dimension become
nonunitary as a result of the blockspin transformations. In addition, a Higgs
potential emerges naturally. The PTs can be written as a product $e^{A_{y}}
e^{\eta} e^{A_{y}}$ of unitary factors $e^{A_{y}}$ and a selfadjoint factor
$e^{\eta}$. The reduction $48 \to 35 + 6 + \bar{6} + 1$ of the adjoint reps of
SU(7) with respect to $SU(6) \supset G_{SM}^{ex}$ leads to three $SU(2)_{L}$
Higgs doublets: one for each flavour. Their zero modes serve as a substitute
for the SM Higgs. When $G_{SM}^{ex}$ is spontaneously broken down to
$U(1)_{em}$, an exponential gauge boson mass splitting occurs naturally. This
breaking leads to $SO(3)_{F}$ flavour gauge boson masses much above the
compactification scale. Thus tree-level FCNC are naturally suppressed. Making
some simplifying assumptions we also calculate fermion masses and CKM mixing
angles. As for the gauge bosons an exponential fermion mass splitting occurs
naturally. The model predicts a large Higgs sector consisting of 30 Higgs
particles and in its simplest form the weak mixing angle $\theta=0.125$.


title:
Inflection point as a manifestation of tricritical point on the dynamic
  phase boundary in Ising meanfield dynamics

abstract:
  We studied the dynamical phase transition in kinetic Ising ferromagnet driven
by oscillating magnetic field in meanfield approximation. The meanfield
differential equation was solved by sixth order Runge-Kutta-Felberg method. We
calculated the transition temperature as a function of amplitude and frequency
of the oscillating field. This was plotted against field amplitude taking
frequency as a parameter. As frequency increases the phase boundary is observed
to become inflated. The phase boundary shows an inflection point which
separates the nature of the transition. On the dynamic phase boundary a
tricritical point (TCP) was found, which separates the nature
(continuous/discontinuous) of the dynamic transition across the phase boundary.
The inflection point is identified as the TCP and hence a simpler method of
determining the position of TCP was found. TCP was observed to shift towards
high field for higher frequency. As frequency decreases the dynamic phase
boundary is observe to shrink. In the zero frequency limit this boundary shows
a tendency to merge to the temperature variation of the coercive field.


title: Twisted Whittaker model and factorizable sheaves

abstract:
  Let G be a reductive group. The geometric Satake equivalence realized the
category of representations of the Langlands dual group ^LG in terms of
spherical perverse sheaves (or D-modules) on the affine Grassmannian
Gr_G=G((t))/G[[t]] of the original group G.
  In the present paper we perform a first step in realizing the category of
representations of the quantum group corresponding to ^LG in terms of the
geometry of Gr_G.
  The idea of the construction belongs to Jacob Lurie.


title: Topological pressure for one-dimensional holomorphic dynamical systems

abstract:
  For a class of one-dimensional holomorphic maps f of the Riemann sphere we
prove that for a wide class of potentials h the topological pressure is
entirely determined by the values of h on the repelling periodic points of f.
This is a version of a classical result of Bowen for hyperbolic diffeomorphisms
in the holomorphic non-uniformly hyperbolic setting.


title: Bounds on exponential sums over small multiplicative subgroups

abstract:
  We show that there is significant cancellation in certain exponential sums
over small multiplicative subgroups of finite fields, giving an exposition of
the arguments by Bourgain and Chang.


title:
On the reconstruction of a magnetosphere of pulsars nearby the light
  cylinder surface

abstract:
  A mechanism of generation of a toroidal component of large scale magnetic
field, leading to the reconstruction of the pulsar magnetospheres is presented.
In order to understand twisting of magnetic field lines, we investigate
kinematics of a plasma stream rotating in the pulsar magnetosphere. Studying an
exact set of equations describing the behavior of relativistic plasma flows,
the increment of the curvature drift instability is derived, and estimated for
$1s$ pulsars. It is shown that a new parametric mechanism is very efficient and
can explain rotation energy pumping in the pulsar magnetospheres.


title: Higgsless Electroweak Theory following from the Spherical Geometry

abstract:
  A new formulation of the Electroweak Model with 3-dimensional spherical
geometry in the target space is suggested. The free Lagrangian in the spherical
field space along with the standard gauge field Lagrangian form the full
Higgsless Lagrangian of the model, whose second order terms reproduce the same
fields with the same masses as the Standard Electroweak Model. The vector
bosons and electron masses are generated automatically, so there is no need in
special mechanism.


title:
The first result of the neutrino magnetic moment measurement in the
  GEMMA experiment

abstract:
  The first result of the neutrino magnetic moment measurement at the
Kalininskaya Nuclear Power Plant (KNPP) with the GEMMA spectrometer is
presented. An antineutrino-electron scattering is investigated. A high-purity
germanium detector of 1.5 kg placed 13.9 m away from the 3 GW reactor core is
used in the spectrometer. The antineutrino flux is $2.73\times 10^{13} \nu_e /
cm^2 / s$. The differential method is used to extract the $\nu$-e
electromagnetic scattering events. The scattered electron spectra taken in 6200
and 2064 hours for the reactor ON and OFF periods are compared. The upper limit
for the neutrino magnetic moment $\mu_\nu < 5.8\times 10^{-11}$ Bohr magnetons
at 90{%} CL is derived from the data processing.


title: Multijet events in the k_T-factorisation scheme

abstract:
  A Markovian Monte Carlo algorithm for multi-parton production in the
high-energy limit is proposed and the matching with unintegrated parton
densities is discussed.


title: Equivalence of symmetric union diagrams

abstract:
  Motivated by the study of ribbon knots we explore symmetric unions, a
beautiful construction introduced by Kinoshita and Terasaka 50 years ago. It is
easy to see that every symmetric union represents a ribbon knot, but the
converse is still an open problem. Besides existence it is natural to consider
the question of uniqueness. In order to attack this question we extend the
usual Reidemeister moves to a family of moves respecting the symmetry, and
consider the symmetric equivalence thus generated. This notion being in place,
we discuss several situations in which a knot can have essentially distinct
symmetric union representations. We exhibit an infinite family of ribbon
two-bridge knots each of which allows two different symmetric union
representations.


title:
Hamiltonian and Brownian systems with long-range interactions: IV.
  General kinetic equations from the quasilinear theory

abstract:
  We develop the kinetic theory of Hamiltonian systems with weak long-range
interactions. Starting from the Klimontovich equation and using a quasilinear
theory, we obtain a general kinetic equation that can be applied to spatially
inhomogeneous systems and that takes into account memory effects. This equation
is valid at order 1/N in a proper thermodynamic limit and it coincides with the
kinetic equation obtained from the BBGKY hierarchy. For N tending to infinity,
it reduces to the Vlasov equation describing collisionless systems. We describe
the process of phase mixing and violent relaxation leading to the formation of
a quasi stationary state (QSS) on the coarse-grained scale. We interprete the
physical nature of the QSS in relation to Lynden-Bell's statistical theory and
discuss the problem of incomplete relaxation. In the second part of the paper,
we consider the relaxation of a test particle in a thermal bath. We derive a
Fokker-Planck equation by directly calculating the diffusion tensor and the
friction force from the Klimontovich equation. We give general expressions of
these quantities that are valid for possibly spatially inhomogeneous systems
with long correlation time. We show that the diffusion and friction terms have
a very similar structure given by a sort of generalized Kubo formula. We also
obtain non-markovian kinetic equations that can be relevant when the
auto-correlation function of the force decreases slowly with time. An interest
of our approach is to develop a formalism that remains in physical space
(instead of Fourier space) and that can deal with spatially inhomogeneous
systems.


title: From shock waves to Brownian motion and 1/f-noise in gas

abstract:
  A formally exact relation is derived which connects thermodynamically
non-equilibrium evolution of gas density distribution after its arbitrary
strong spatially non-uniform perturbation and evolution of many-particle
correlations between path of some marked particle and its surroundings in
equilibrium gas. This relation directly confirms significance of the
many-particle correlations even under the Boltzmann-Grad limit and thus
validates the earlier suggested revision of kinetics.


title: Fine Structure of Dark Energy and New Physics

abstract:
  Following our recent work on the cosmological constant problem, in this
letter we make a specific proposal regarding the fine structure (i.e., the
spectrum) of dark energy. The proposal is motivated by a deep analogy between
the blackbody radiation problem, which led to the development of quantum
theory, and the cosmological constant problem, which we have recently argued
calls for a conceptual extension of the quantum theory. We argue that the fine
structure of dark energy is governed by a Wien distribution, indicating its
dual quantum and classical nature. We discuss a few observational consequences
of such a picture of dark energy.


title: Light propagation through a coiled optical fiber and Pancharatnam phase

abstract:
  The nature of changes in the interference pattern caused by the presence of
polarization-changing elements in one or both beams of an interferometer, in
particular those caused by an effective optical activity due to passage of a
polarized beam through a coiled optical fiber are clarified. It is pointed out
that for an incident state that is not circularly polarized so that the two
interfering beams go to different polarization states, there is an observable
nonzero Pancharatnam phase shift between them which depends on the incident
polarization state and on the solid angle subtended by the track of the
$\vec{k}$-vector at the centre of the sphere of k-vectors. The behaviour of
this phase shift is singular when the two interfering states are nearly
orthogonal. It is shown that for zero path difference between the two beams,
the amplitude of intensity modulation as a function of optical activity is
independent of the incident polarization state.


title: Photons as a Probe of Minicharged Particles

abstract:
  Low energy experiments with photons can provide deep insights into
fundamental physics. In this note we concentrate on minicharged particles. We
discuss how they can arise in extensions of the standard model and how we can
search for them using a variety of laboratory experiments.


title:
Modeling Epidemic Spread in Synthetic Populations - Virtual Plagues in
  Massively Multiplayer Online Games

abstract:
  A virtual plague is a process in which a behavior-affecting property spreads
among characters in a Massively Multiplayer Online Game (MMOG). The MMOG
individuals constitute a synthetic population, and the game can be seen as a
form of interactive executable model for studying disease spread, albeit of a
very special kind. To a game developer maintaining an MMOG, recognizing,
monitoring, and ultimately controlling a virtual plague is important,
regardless of how it was initiated. The prospect of using tools, methods and
theory from the field of epidemiology to do this seems natural and appealing.
We will address the feasibility of such a prospect, first by considering some
basic measures used in epidemiology, then by pointing out the differences
between real world epidemics and virtual plagues. We also suggest directions
for MMOG developer control through epidemiological modeling. Our aim is
understanding the properties of virtual plagues, rather than trying to
eliminate them or mitigate their effects, as would be in the case of real
infectious disease.


title: A characteristic approach to the quasi-normal mode problem

abstract:
  In this paper we discuss a new approach to the quasinormal-mode problem in
general relativity. By combining a characteristic formulation of the
perturbation equations with the integration of a suitable phase-function for a
complex valued radial coordinate, we reformulate the standard outgoing-wave
boundary condition as a zero Dirichlet condition. This has a number of
important advantages over previous strategies. The characteristic formulation
permits coordinate compactification, which means that we can impose the
boundary condition at future null infinity. The phase function avoids
oscillatory behaviour in the solution, and the use of a complex radial variable
allows a clean distinction between out- and ingoing waves. We demonstrate that
the method is easy to implement, and that it leads to high precision numerical
results. Finally, we argue that the method should generalise to the important
problem of rapidly rotating neutron star spacetimes.


title: The magnetic fields of large Virgo Cluster spirals

abstract:
  Because of its proximity the Virgo Cluster is an excellent target for
studying interactions of galaxies with the cluster environment. Both the
high-velocity tidal interactions and effects of ram pressure stripping by the
intracluster gas can be investigated. Optical and/or \ion{H}{i} observations do
not always show effects of weak interactions between galaxies and their
encounters with the cluster medium. For this reason we searched for possible
anomalies in the magnetic field structure in Virgo Cluster spirals which could
be attributed to perturbations in their gas distribution and kinematics. Five
angularly large Virgo Cluster spiral galaxies (NGC 4501, NGC 4438, NGC 4535,
NGC 4548 and NGC 4654) were the targets for a sensitive total power and
polarization study using the 100-m radio telescope in Effelsberg at 4.85 GHz.
For two objects polarization data at higher frequencies have been obtained
allowing Faraday rotation analysis. Distorted magnetic field structures were
identified in all galaxies. Interaction-induced magnetized outflows were found
in NGC 4438 (due to nuclear activity) and NGC 4654 (a combination of tidal
tails and ram pressure effects). Almost all objects (except the anaemic NGC
4548) exhibit distortions in polarized radio continuum attributable to
influence of the ambient gas. For some galaxies they agree with observations of
other species, but sometimes (NGC 4535) the magnetic field is the only tracer
of the interaction with the cluster environment. The cluster environment
clearly affects the evolution of the galaxies due to ram pressure and tidal
effects. Magnetic fields provide a very long-lasting memory of past
interactions. Therefore, they are a good tracer of weak interactions which are
difficult to detect by other observations.


title:
Search for pulsation among suspected A-type binaries and the new
  multiperiodic Delta Scuti star HD217860

abstract:
  We have explored a sample of suspected A-type binaries in a systematic way,
both spectroscopically and photometrically. Due to their location in the H-R
diagram, indications of pulsation and/or chemical peculiarities among these
suspected binary (or multiple) systems may be found. High-resolution
spectroscopy obtained with the ELODIE and MUSICOS spectrographs was used in
combination with a few nights of differential CCD photometry in order to search
for pulsation(s). Of the 32 investigated targets, eight are spectroscopic
binaries, one of which is a close binary also showing eclipses, and three have
been identified as Delta Scuti pulsators with rapid line-profile variations.
Among the latter stars, HD 217860 reveals interesting multiperiodic photometric
and spectroscopic variations, with up to eight frequencies common to two large
photometric data sets. We suggest that at least one radial overtone mode is
excited among the two most dominant frequencies. We furthermore found evidence
for a strong modulation of the amplitude(s) and/or the (radial) frequency
content of this intriguing Delta Scuti star.