title:
The effect of magnetic fields on the formation of circumstellar discs
  around young stars

abstract:
  We present first results of our simulations of magnetic fields in the
formation of single and binary stars using a recently developed method for
incorporating Magnetohydrodynamics (MHD) into the Smoothed Particle
Hydrodynamics (SPH) method. An overview of the method is presented before
discussing the effect of magnetic fields on the formation of circumstellar
discs around young stars. We find that the presence of magnetic fields during
the disc formation process can lead to significantly smaller and less massive
discs which are much less prone to gravitational instability. Similarly in the
case of binary star formation we find that magnetic fields, overall, suppress
fragmentation. However these effects are found to be largely driven by magnetic
pressure. The relative importance of magnetic tension is dependent on the
orientation of the field with respect to the rotation axis, but can, with the
right orientation, lead to a dilution of the magnetic pressure-driven
suppression of fragmentation.


title:
The effect of the relative orientation between the coronal field and new
  emerging flux: I Global Properties

abstract:
  The emergence of magnetic flux from the convection zone into the corona is an
important process for the dynamical evolution of the coronal magnetic field. In
this paper we extend our previous numerical investigations, by looking at the
process of flux interaction as an initially twisted flux tube emerges into a
plane parallel, coronal magnetic field. Significant differences are found in
the dynamical appearance and evolution of the emergence process depending on
the relative orientation between the rising flux system and any preexisting
coronal field. When the flux systems are nearly anti-parallel, the experiments
show substantial reconnection and demonstrate clear signatures of a high
temperature plasma located in the high velocity outflow regions extending from
the reconnection region. However, the cases that have a more parallel
orientation of the flux systems show very limited reconnection and none of the
associated features. Despite the very different amount of reconnection between
the two flux systems, it is found that the emerging flux that is still
connected to the original tube, reaches the same height as a function of time.
As a compensation for the loss of tube flux, a clear difference is found in the
extent of the emerging loop in the direction perpendicular to the main axis of
the initial flux tube. Increasing amounts of magnetic reconnection decrease the
volume, which confines the remaining tube flux.


title: Supersymmetric Black Rings on Eguchi-Hanson Space

abstract:
  We construct new supersymmetric black ring solutions on the Eguchi-Hanson
base space as solutions of five-dimensional minimal supergravity. The solutions
have the same two angular momentum components and the asymptotic structure on
timeslices is asymptotically locally Euclidean. The S^1-direction of the black
ring is along the equator on a S^2-bolt on the Eguchi-Hanson space. We also
investigate the limit to a black hole, which describes the BMPV black hole with
the topology of the lens space L(2;1)=S^3/Z_2.


title: Minimal qudit code for a qubit in the phase-damping channel

abstract:
  Using the stabilizer formalism we construct the minimal code into a
D-dimensional Hilbert space (qudit) to protect a qubit against phase damping.
The effectiveness of this code is then studied by means of input-output
fidelity.


title: A New Tool for Seismology--the Cumulative Spectral Power

abstract:
  The power spectral density (PSD) function is commonly used to specify
seismometer performance. It is derived from the FFT of acceleration and
correction is made for the transfer function of the instrument that generated
the data. As with any such spectrum of density (`per Hz') type, the noise
inherent to a PSD is large. This article illustrates the value of a function
that is derived from the PSD and for which the influence of noise is
significantly reduced. Called the cumulative spectral power (CSP), it is
obtained from the PSD through the noise-reducing process of integration. The
maximum of the CSP (corresponding to the longest graphed value of the period)
provides a means for estimating the total vibrational power of the earth. The
present author has significantly simplified the process of PSD generation. Thus
routine graphing is straightforwared-of first the FFT, followed by the
generation of both a PSD and its associated CSP. The unique properties of the
CSP make it valuable for the study of a variety of earth dynamics. For example,
the strking simplicity of a CSP graph generated from a record containing a
strong teleseismic earthquake is undoubtedly important to the development and
refinement of any viable theory of earthquake dynamics.


title: Photon mass and quantum effects of the Aharonov-Bohm type

abstract:
  The magnetic field due to the photon rest mass $m_{ph}$ modifies the standard
results of the Aharonov-Bohm effect for electrons, and of other recent quantum
effects. For the effect involving a coherent superposition of beams of
particles with opposite electromagnetic properties, by means of a table-top
experiment, the limit $m_{ph}x10^{-51}g$ is achievable, improving by 6 orders
of magnitude that derived by Boulware and Deser for the Aharonov-Bohm effect.


title:
The Nature of Quantum Hall States near the Charge Neutral Dirac Point in
  Graphene

abstract:
  We investigate the quantum Hall (QH) states near the charge neutral Dirac
point of a high mobility graphene sample in high magnetic fields. We find that
the QH states at filling factors $\nu=\pm1$ depend only on the perpendicular
component of the field with respect to the graphene plane, indicating them to
be not spin-related. A non-linear magnetic field dependence of the activation
energy gap at filling factor $\nu=1$ suggests a many-body origin. We therefore
propose that the $\nu=0$ and $\pm1$ states arise from the lifting of the spin
and sub-lattice degeneracy of the $n=0$ LL, respectively.


title: Entanglement in fermionic systems

abstract:
  The anticommuting properties of fermionic operators, together with the
presence of parity conservation, affect the concept of entanglement in a
composite fermionic system. Hence different points of view can give rise to
different reasonable definitions of separable and entangled states. Here we
analyze these possibilities and the relationship between the different classes
of separable states. We illustrate the differences by providing a complete
characterization of all the sets defined for systems of two fermionic modes.
The results are applied to Gibbs states of infinite chains of fermions whose
interaction corresponds to a XY-Hamiltonian with transverse magnetic field.


title:
Large nuclear Overhauser fields detected in vertically-coupled double
  quantum dots

abstract:
  We report the electrical induction and detection of dynamic nuclear
polarization in the spin-blockade regime of double GaAs vertical quantum dots.
The largest Overhauser field observed was about 4 Tesla, corresponding to a
nuclear polarization of about 40% in the present device. A phenomenological
model is presented to provide a qualitative understanding of our results.


title: Weil-Petersson Metric Geometry Quick Overview

abstract:
  A quick overview is provided on the current development of the WP metric
geometry.


title:
On compact manifolds admitting indefinite metrics with parallel Weyl
  tensor

abstract:
  Compact pseudo-Riemannian manifolds that have parallel Weyl tensor without
being conformally flat or locally symmetric are known to exist in infinitely
many dimensions greater than 4. We prove some general topological properties of
such manifolds, namely, vanishing of the Euler characteristic and real
Pontryagin classes, and infiniteness of the fundamental group. We also show
that, in the Lorentzian case, each of them is at least 5-dimensional and admits
a two-fold cover which is a bundle over the circle.


title: The TF Limit for Rapidly Rotating Bose Gases in Anharmonic Traps

abstract:
  Starting from the full many body Hamiltonian we derive the leading order
energy and density asymptotics for the ground state of a dilute, rotating Bose
gas in an anharmonic trap in the ` Thomas Fermi' (TF) limit when the
Gross-Pitaevskii coupling parameter and/or the rotation velocity tend to
infinity. Although the many-body wave function is expected to have a
complicated phase, the leading order contribution to the energy can be computed
by minimizing a simple functional of the density alone.


title:
Shallow decay phase of GRB X-ray afterglows from relativistic wind
  bubbles

abstract:
  The postburst object of a GRB is likely to be a highly magnetized, rapidly
rotating compact object (e.g., a millisecond magnetar), which could produce an
ultrarelativistic electron-positron-pair wind. The interaction of such a wind
with an outwardly expanding fireball ejected during the burst leads to a
relativistic wind bubble (RWB). We numerically calculate the dynamics and
radiative properties of RWBs and use this model to explain the shallow decay
phase of the early X-ray afterglows observed by Swift. We find that RWBs can
fall into two types: forward-shock-dominated and reverse-shock-dominated
bubbles. Their radiation during a period of $\sim 10^{2}-10^{5}$ seconds is
dominated by the shocked medium and the shocked wind, respectively, based on
different magnetic energy fractions of the shocked materials. For both types,
the resulting light curves always have a shallow decay phase. In addition, we
provide an example fit to the X-ray afterglows of GRB 060813 and GRB 060814 and
show that they could be produced by forward-shock-dominated and
reverse-shock-dominated bubbles, respectively. This implies that, for some
early afterglows (e.g., GRB 060814), the long-lasting reverse shock emission is
strong enough to explain their shallow decay phase.


title:
On monotonicity, stability, and construction of central schemes for
  hyperbolic conservation laws with source terms (Revised Version)

abstract:
  The monotonicity and stability of difference schemes for, in general,
hyperbolic systems of conservation laws with source terms are studied. The
basic approach is to investigate the stability and monotonicity of a non-linear
scheme in terms of its corresponding scheme in variations. Such an approach
leads to application of the stability theory for linear equation systems to
establish stability of the corresponding non-linear scheme. The main
methodological innovation is the theorems establishing the notion that a
non-linear scheme is stable (and monotone) if the corresponding scheme in
variations is stable (and, respectively, monotone). Criteria are developed for
monotonicity and stability of difference schemes associated with the numerical
analysis of systems of partial differential equations. The theorem of
Friedrichs (1954) is generalized to be applicable to variational schemes with
non-symmetric matrices. A new modification of the central Lax-Friedrichs (LxF)
scheme is developed to be of the second order accuracy. A monotone piecewise
cubic interpolation is used in the central schemes to give an accurate
approximation for the model in question. The stability and monotonicity of the
modified scheme are investigated. Some versions of the modified scheme are
tested on several conservation laws, and the scheme is found to be accurate and
robust. As applied to hyperbolic conservation laws with, in general, stiff
source terms, it is constructed a second order scheme based on
operator-splitting techniques.


title: Mining Patterns with a Balanced Interval

abstract:
  In many applications it will be useful to know those patterns that occur with
a balanced interval, e.g., a certain combination of phone numbers are called
almost every Friday or a group of products are sold a lot on Tuesday and
Thursday.
  In previous work we proposed a new measure of support (the number of
occurrences of a pattern in a dataset), where we count the number of times a
pattern occurs (nearly) in the middle between two other occurrences. If the
number of non-occurrences between two occurrences of a pattern stays almost the
same then we call the pattern balanced.
  It was noticed that some very frequent patterns obviously also occur with a
balanced interval, meaning in every transaction. However more interesting
patterns might occur, e.g., every three transactions. Here we discuss a
solution using standard deviation and average. Furthermore we propose a simpler
approach for pruning patterns with a balanced interval, making estimating the
pruning threshold more intuitive.


title: Physical instrumental vetoes for gravitational-wave burst triggers

abstract:
  We present a robust strategy to \emph{veto} certain classes of instrumental
glitches that appear at the output of interferometric gravitational-wave (GW)
detectors.This veto method is `physical' in the sense that, in order to veto a
burst trigger, we make use of our knowledge of the coupling of different
detector subsystems to the main detector output. The main idea behind this
method is that the noise in an instrumental channel X can be \emph{transferred}
to the detector output (channel H) using the \emph{transfer function} from X to
H, provided the noise coupling is \emph{linear} and the transfer function is
\emph{unique}. If a non-stationarity in channel H is causally related to one in
channel X, the two have to be consistent with the transfer function. We
formulate two methods for testing the consistency between the burst triggers in
channel X and channel H. One method makes use of the \emph{null-stream}
constructed from channel H and the \emph{transferred} channel X, and the second
involves cross-correlating the two. We demonstrate the efficiency of the veto
by `injecting' instrumental glitches in the hardware of the GEO 600 detector.
The \emph{veto safety} is demonstrated by performing GW-like hardware
injections. We also show an example application of this method using 5 days of
data from the fifth science run of GEO 600. The method is found to have very
high veto efficiency with a very low accidental veto rate.


title: Cyclicity of period annuli and principalization of Bautin ideals

abstract:
  We prove that the maximal number of limit cycles which bifurcate from an open
period annulus under a given multi-parameter analytic deformation of a given
analytic vector field is the same as in an appropriate one-parameter analytic
deformation of the field, provided that this cyclicity is finite. Along the
same lines we give also a bound of the cyclicity of homoclinic saddle loops.


title:
Positron studies of surfaces, structure and electronic properties of
  nanocrystals

abstract:
  A brief review is given of recent positron studies of metal and semiconductor
nanocrystals. The prospects offered by positron annihilation as a sensitive
method to access nanocrystal (NC) properties are described and compared with
other experimental methods. The tunability of the electronic structure of
nanocrystals underlies their great potential for application in many areas.
Owing to their large surface-to-volume ratio, the surfaces and interfaces of
NCs play a crucial role in determining their properties. Here we focus on
positron 2D angular correlation of annihilation radiation (2D-ACAR) and
(two-detector) Doppler studies for investigating surfaces and electronic
properties of CdSe NCs.


title:
Lorentz Space Estimates and Jacobian Convergence for the Ginzburg-Landau
  Energy with Applied Magnetic Field

abstract:
  In this paper we continue the study of Lorentz space estimates for the
Ginzburg-Landau energy started in our previous paper, \cite{p1}. We focus on
getting estimates for the Ginzburg-Landau energy with external magnetic field
$h_{ex}$ in certain interesting regimes of $h_{ex}$. This allows us to show
that for configurations close to minimizers or local minimizers of the energy,
the vorticity mass of the configuration $(u,A)$ is comparable to the
$L^{2,\infty}$ Lorentz space norm of $\nabla_A u$. We also establish
convergence of the gauge-invariant Jacobians (vorticity measures) in the dual
of a function space defined in terms of Lorentz spaces.


title:
Classical approximation schemes for the ground-state energy of quantum
  and classical Ising spin Hamiltonians on planar graphs

abstract:
  We describe an efficient approximation algorithm for evaluating the
ground-state energy of the classical Ising Hamiltonian with linear terms on an
arbitrary planar graph. The running time of the algorithm grows linearly with
the number of spins and exponentially with 1/epsilon, where epsilon is the
worst-case relative error. This result contrasts the well known fact that exact
computation of the ground-state energy for the two-dimensional Ising spin glass
model is NP-hard. We also present a classical approximation algorithm for the
Local Hamiltonian Problem or Quantum Ising Spin Glass problem on a planar graph
with bounded degree which is known to be a QMA-complete problem. Using a
different technique we find a classical approximation algorithm for the quantum
Ising spin glass problem on the simplest planar graph with unbounded degree,
the star graph.


title: The Search for a New Equivalence Principle

abstract:
  The new emerging quantum physics - quantum computing conceptual bridge,
mandates a ``grand unification'' of space-time-matter and quantum information
(all quantized), with deep implications for science in general. The major
physics revolutions in our understanding of the universe are briefly reviewed
and a ``missing'' equivalence principle is identified and its nature explained.
An implementation as an external super-symmetry $\C{E}=ic\C{P}$ is suggested,
generalizing the Wick rotation ``trick''. Taking advantage of the
interpretation of entropy as a measure of symmetry, it is naturally asimilated
within the present Feynman Path Integral algebraic formalism.


title: Quotients of cluster categories

abstract:
  Higher cluster categories were recently introduced as a generalization of
cluster categories.
  This paper shows that in Dynkin types A and D, half of all higher cluster
categories are actually just quotients of cluster categories. The other half
can be obtained as quotients of 2-cluster categories, the "lowest" type of
higher cluster categories.
  Hence, in Dynkin types A and D, all higher cluster phenomena are implicit in
cluster categories and 2-cluster categories. In contrast, the same is not true
in Dynkin type E.


title:
Determination of intrinsic switching field distributions in
  perpendicular recording media: numerical study of the $\Delta H(M, \Delta M)$
  method

abstract:
  We present a numerical study of the $\Delta H(M,\Delta M)$ method and its
ability to accurately determine intrinsic switching field distributions in
interacting granular magnetic materials such as perpendicular recording media.
In particular, we study how this methodology fails for large ferromagnetic
inter-granular interactions, at which point the associated strongly correlated
magnetization reversal cannot be properly represented by the mean-field
approximation, upon which the $\Delta H(M,\Delta M)$ method is based. In this
study, we use a 2-dimensional array of symmetric hysterons that have an
intrinsic switching field distribution of standard deviation $\sigma$ and
ferromagnetic nearest-neighbor interactions $J$. We find the $\Delta H(M,\Delta
M)$ method to be very accurate for small $J/\sigma$ values, while substantial
errors develop once the effective exchange field becomes comparable with
$\sigma$, corroborating earlier results from micromagnetic simulations. We
furthermore demonstrate that this failure is correlated with deviations from
data set redundancy, which is a key property of the mean-field approximation.
Thus, the $\Delta H(M,\Delta M)$ method fails in a well defined and
quantifiable manner that can be easily assessed from the data sets alone.


title:
Focusing of high-energy particles in the electrostatic field of a
  homogeneously charged sphere and the effective momentum approximation

abstract:
  The impact of the strongly attractive electromagnetic field of heavy nuclei
on electrons in quasi-elastic (e,e') scattering is often accounted for by the
effective momentum approximation. This method is a plane wave Born
approximation which takes the twofold effect of the attractive nucleus on
initial and final state electrons into account, namely the modification of the
electron momentum in the vicinity of the nucleus, and the focusing of electrons
towards the nuclear region leading to an enhancement of the corresponding wave
function amplitudes. The focusing effect due to the attractive Coulomb field of
a homogeneously charged sphere on a classical ensemble of charged particles
incident on the field is calculated in the highly relativistic limit and
compared to results obtained from exact solutions of the Dirac equation. The
result is relevant for the theoretical foundation of the effective momentum
approximation and describes the high energy behavior of the amplitude of
continuum Dirac waves in the potential of a homogeneously charged sphere. Our
findings indicate that the effective momentum approximation is a useful
approximation for the calculation of Coulomb corrections in (e,e') scattering
off heavy nuclei for sufficiently high electron energies and momentum transfer.


title: Can QFT on Moyal-Weyl spaces look as on commutative ones?

abstract:
  We sketch a natural affirmative answer to the question based on a joint work
[11] with J. Wess. There we argue that a proper enforcement of the "twisted
Poincare'" covariance makes any differences $(x-y)^\mu$ of coordinates of two
copies of the Moyal-Weyl deformation of Minkowski space like undeformed. Then
QFT in an operator approach becomes compatible with (minimally adapted)
Wightman axioms and time-ordered perturbation theory, and physically equivalent
to ordinary QFT, as observables involve only coordinate differences.


title: $B_{s,d} \to \pi\pi,\pi K, KK$: Status and Prospects

abstract:
  Several years ago, it was pointed out that the U-spin-related decays
$B_d\to\pi^+\pi^-$, $B_s\to K^+K^-$ and $B_d\to\pi^\mp K^\pm$, $B_s\to \pi^\pm
K^\mp$ offer interesting strategies for the extraction of the angle gamma of
the unitarity triangle. Using the first results from the Tevatron on the $B_s$
decays and the B-factory data on $B_{u,d}$ modes, we compare the determinations
of gamma from both strategies, study the sensitivity on U-spin-breaking
effects, discuss the resolution of discrete ambiguities, predict observables
that were not yet measured but will be accessible at LHCb, explore the
extraction of the width difference $\Delta\Gamma_s$ from untagged $B_s\to
K^+K^-$ rates, and address the impact of new physics. The data for the
$B_d\to\pi^+\pi^-$, $B_s\to K^+K^-$ system favour the BaBar measurement of
direct CP violation in $B_d\to\pi^+\pi^-$, which will be used in the numerical
analysis, and result in a fortunate situation, yielding
$\gamma=(66.6^{+4.3+4.0}_{-5.0-3.0})^\circ$, where the latter errors correspond
to a generous estimate of U-spin-breaking effects. On the other hand, the
$B_d\to\pi^\mp K^\pm$, $B_s\to \pi^\pm K^\mp$ analysis leaves us with
$26^\circ\leq\gamma\leq70^\circ$, and points to a value of the $B_s\to \pi^\pm
K^\mp$ branching ratio that is larger than the current Tevatron result. An
important further step will be the measurement of mixing-induced CP violation
in $B_s\to K^+K^-$, which will also allow us to extract the $B^0_s$--$\bar
B^0_s$ mixing phase unambiguously with the help of $B_s\to J/\psi \phi$ at the
LHC. Finally, the measurement of direct CP violation in $B_s\to K^+K^-$ will
make the full exploitation of the physics potential of the $B_{s,d}\to \pi\pi,
\pi K, KK$ modes possible.


title:
Rapidity and energy dependence of the electric charge correlations in
  A+A collisions at the SPS energies

abstract:
  Results from electric charge correlations studied with the Balance Function
method in A+A collisions from 20\emph{A} to 158\emph{A} GeV are presented in
two different rapidity intervals: In the mid-rapidity region we observe a
decrease of the width of the Balance Function distribution with increasing
centrality of the collision, whereas this effect vanishes in the forward
rapidity region.
  Results from the energy dependence study in central Pb+Pb collisions show
that the narrowing of the Balance Function expressed by the normalised width
parameter \textit{W} increases with energy towards the highest SPS and RHIC
energies.
  Finally we compare our experimental data points with predictions of several
models. The hadronic string models UrQMD and HIJING do not reproduce the
observed narrowing of the Balance Function. However, AMPT which contains a
quark-parton transport phase before hadronization can reproduce the narrowing
of the BF's width with centrality. This confirms the proposed sensitivity of
the Balance Function analysis to the time of hadronization.


title:
Spin dependent resonant tunneling through 6 micron diameter double
  barrier resonant tunneling diode

abstract:
  A vertical resonant tunneling diode (RTD) based on the paramagnetic
Zn1-x-yMnyCdxSe system has been fabricated with a pillar diameter down to ~ 6
micron. The diode exhibits high quality resonant tunneling characteristics
through the electron sub-band of the quantum well at a temperature of 4.2K,
where a clear phonon replica was observable in addition to the primary peak.
Both peaks show a giant Zeeman splitting in an applied magnetic field.
Employing a self-consistent real-time Green's function method, the
current-voltage characteristic was simulated, showing good agreement with the
measured result.


title:
One- and two-component bottle-brush polymers: simulations compared to
  theoretical predictions

abstract:
  Scaling predictions and results from self-consistent field calculations for
bottle-brush polymers with a rigid backbone and flexible side chains under good
solvent conditions are summarized and their validity and applicability is
assessed by a comparison with Monte Carlo simulations of a simple lattice
model. It is shown that under typical conditions, as they are also present in
experiments, only a rather weak stretching of the side chains is realized, and
then the scaling predictions based on the extension of the Daoud-Cotton blob
picture are not applicable.
  Also two-component bottle brush polymers are considered, where two types
(A,B) of side chains are grafted, assuming that monomers of different kind
repel each other. In this case, variable solvent quality is allowed for, such
that for poor solvent conditions rather dense cylinder-like structures result.
Theories predict ``Janus Cylinder''-type phase separation along the backbone in
this case. The Monte Carlo simulations, using the pruned-enriched Rosenbluth
method (PERM) then are restricted to rather short side chain length.
Nevertheless, evidence is obtained that the phase separation between an A-rich
part of the cylindrical molecule and a B-rich part can only occur locally. The
correlation length of this microphase separation can be controlled by the
solvent quality. This lack of a phase transition is interpreted by an analogy
with models for ferromagnets in one space dimension.


title:
A highly polarised radio jet during the 1998 outburst of the black hole
  transient XTE J1748-288

abstract:
  XTE J1748-288 is a black hole X-ray transient which went into outburst in
1998 June. The X-ray lightcurves showed canonical morphologies, with minor
variations on the ``Fast Rise Exponential Decay'' profile. The radio source,
however, reached an unusually high flux density of over 600 mJy. This high
radio flux was accompanied by an exceptional (>20%) fractional linear
polarisation, the variability of which was anti-correlated with the flux
density. We use this variability to discuss possible depolarisation mechanisms
and to predict the underlying behaviour of the (unresolved) core/jet
components.


title: Scattering Dynamics of Driven Closed Billiards

abstract:
  We investigate the classical scattering dynamics of the driven elliptical
billiard. Two fundamental scattering mechanisms are identified and employed to
understand the rich behavior of the escape rate. A long-time algebraic decay
which can be tuned by varying the driving amplitude is established. Pulsed
escape rates and decelerated escaping particles are generic properties of the
harmonically breathing billiard. This suggests time-dependent billiards as
prototype systems to study the nonequilibrium evolution of classical ensembles
encountering a multitude of scattering processes off driven targets.


title: Discrepancies in Determinations of the Ginzburg-Landau Parameter

abstract:
  Long-standing discrepancies within determinations of the Ginzburg-Landau
parameter $\kappa$ from supercritical field measurements on superconducting
microspheres are reexamined. The discrepancy in tin is shown to result from
differing methods of analyses, whereas the discrepancy in indium is a
consequence of significantly differing experimental results. The reanalyses
however confirms the lower $\kappa$ determinations to within experimental
uncertainties.


title: On the Riemannian Penrose inequality in dimensions less than 8

abstract:
  The Positive Mass Theorem states that a complete asymptotically flat manifold
of nonnegative scalar curvature has nonnegative mass. The Riemannian Penrose
inequality provides a sharp lower bound for the mass when black holes are
present. More precisely, this lower bound is given in terms of the area of an
outermost minimal surface, and equality is achieved only for Schwarzschild
metrics. The Riemannian Penrose inequality was first proved in three dimensions
in 1997 by G. Huisken and T. Ilmanen for the case of a single black hole. In
1999, H. Bray extended this result to the general case of multiple black holes
using a different technique. In this paper we extend Bray's technique to
dimensions less than 8.


title: General Properties of Quantum Zero-Knowledge Proofs

abstract:
  This paper studies the complexity classes QZK and HVQZK of problems having a
quantum computational zero-knowledge proof system and an honest-verifier
quantum computational zero-knowledge proof system, respectively. The results
proved in this paper include: (a) HVQZK = QZK, (b) any problem in QZK has a
public-coin quantum computational zero-knowledge proof system, (c) any problem
in QZK has a quantum computational zero-knowledge proof system of perfect
completeness, and (d) any problem in QZK has a three-message public-coin
quantum computational zero-knowledge proof system of perfect completeness with
arbitrarily small constant error in soundness. All the results above are
unconditional and do not rely any computational assumptions. For the classes
QPZK, HVQPZK, and QSZK of problems having a quantum perfect zero-knowledge
proof system, an honest-verifier quantum perfect zero-knowledge proof system,
and a quantum statistical zero-knowledge proof system, respectively, the
following new properties are proved: (e) HVQPZK = QPZK, (f) any problem in QPZK
has a public-coin quantum perfect zero-knowledge proof system, (g) any problem
in QSZK has a quantum statistical zero-knowledge proof system of perfect
completeness, and (h) any problem in QSZK has a three-message public-coin
quantum statistical zero-knowledge proof system of perfect completeness with
arbitrarily small constant error in soundness. It is stressed that our proofs
are direct and do not use complete promise problems or those equivalents. This
gives a unified framework that works well for all of quantum perfect,
statistical, and computational zero-knowledge proofs, and enables us to prove
properties even on the computational and perfect zero-knowledge proofs for
which no complete promise problems are known.


title: An Entropy-Weighted Sum over Non-Perturbative Vacua

abstract:
  We discuss how, in a Universe restricted to the causal region connected to
the observer, General Relativity implies the quantum nature of physical
phenomena and directly leads to a string theory scenario, whose dynamics is
ruled by a functional that weights all configurations according to their
entropy. The most favoured configurations are those of minimal entropy. Along
this class of vacua a four-dimensional space-time is automatically selected;
when, at large volume, a description of space-time in terms of classical
geometry can be recovered, the entropy-weighted sum reduces to the ordinary
Feynman's path integral. What arises is a highly predictive scenario,
phenomenologically compatible with the experimental observations and
measurements, in which everything is determined in terms of the fundamental
constants and the age of the Universe, with no room for freely-adjustable
parameters. We discuss how this leads to the known spectrum of particles and
interactions. Besides the computation of masses and couplings, CKM matrix
elements, cosmological constant, expansion parameters of the Universe etc...,
all resulting, within the degree of the approximation we used, in agreement
with the experimental observations, we also discuss how this scenario passes
the tests provided by cosmology and the constraints imposed by the physics of
the primordial Universe.


title:
Some general properties of the renormalized stress-energy tensor for
  static quantum states on (n+1)-dimensional spherically symmetric black holes

abstract:
  We study the renormalized stress-energy tensor (RSET) for static quantum
states on (n+1)-dimensional, static, spherically symmetric black holes. By
solving the conservation equations, we are able to write the stress-energy
tensor in terms of a single unknown function of the radial co-ordinate, plus
two arbitrary constants. Conditions for the stress-energy tensor to be regular
at event horizons (including the extremal and ``ultra-extremal'' cases) are
then derived using generalized Kruskal-like co-ordinates. These results should
be useful for future calculations of the RSET for static quantum states on
spherically symmetric black hole geometries in any number of space-time
dimensions.


title:
Model-independent constraints on reionization from large-scale CMB
  polarization

abstract:
  On large angular scales, the polarization of the CMB contains information
about the evolution of the average ionization during the epoch of reionization.
Interpretation of the polarization spectrum usually requires the assumption of
a fixed functional form for the evolution, e.g. instantaneous reionization. We
develop a model-independent method where a small set of principal components
completely encapsulate the effects of reionization on the large-angle E-mode
polarization for any reionization history within an adjustable range in
redshift. Using Markov Chain Monte Carlo methods, we apply this approach to
both the 3-year WMAP data and simulated future data. WMAP data constrain two
principal components of the reionization history, approximately corresponding
to the total optical depth and the difference between the contributions to the
optical depth at high and low redshifts. The optical depth is consistent with
the constraint found in previous analyses of WMAP data that assume
instantaneous reionization, with only slightly larger uncertainty due to the
expanded set of models. Using the principal component approach, WMAP data also
place a 95% CL upper limit of 0.08 on the contribution to the optical depth
from redshifts z>20. With improvements in polarization sensitivity and
foreground modeling, approximately five of the principal components can
ultimately be measured. Constraints on the principal components, which probe
the entire reionization history, can test models of reionization, provide
model-independent constraints on the optical depth, and detect signatures of
high-redshift reionization.


title:
Search for Direct Photons from $\sqrt{s_{NN}}=200GeV$ AuAu Collisions
  Using a New $\pi^{0}$ Tagging Method in the PHENIX Experiment at RHIC

abstract:
  Direct photons provide a insightful tool to study the different stages of a
heavy ion collision, especially the formation of a quark-gluon plasma, without
being influenced by the strong interaction and hadronization processes. The
yield of direct photons can be determined based on the inclusive photon yield
and the background from hadronic decays. We present a new analysis technique
applied to PHENIX Run4 Au+Au dataset. It uses strict particle
identification(PID) in the Electromagnetic Calorimeter(EMCal) and a charged
particle veto to extract a clean photon signal. These photons are then tagged
with EMCal photon candidates with loose PID cuts, which can be reconstructed
with high efficiency, to determine the fraction of photons originating from
$\pi^{0}$ decays. Many systematic uncertainties and detector effects cancel in
this method.


title:
Supersymmetric methods in the traveling variable: inside neurons and at
  the brain scale

abstract:
  We apply the mathematical technique of factorization of differential
operators to two different problems. First we review our results related to the
supersymmetry of the Montroll kinks moving onto the microtubule walls as well
as mentioning the sine-Gordon model for the microtubule nonlinear excitations.
Second, we find analytic expressions for a class of one-parameter solutions of
a sort of diffusion equation of Bessel type that is obtained by supersymmetry
from the homogeneous form of a simple damped wave equations derived in the
works of P.A. Robinson and collaborators for the corticothalamic system. We
also present a possible interpretation of the diffusion equation in the brain
context


title: A He I Case-B Recombination Code

abstract:
  Recent calculations of collisionless, Case-B, He I emissivities were
performed by Bauman et al. (2005). The source code used in the calculation has
been freely available online since that paper was published. A number of
changes have been made to simplify the use of the code by third parties. Here I
provide details on how to obtain, compile, and execute the program and
interpret the results.


title:
Standard forms and entanglement engineering of multimode Gaussian states
  under local operations

abstract:
  We investigate the action of local unitary operations on multimode (pure or
mixed) Gaussian states and single out the minimal number of locally invariant
parametres which completely characterise the covariance matrix of such states.
For pure Gaussian states, central resources for continuous-variable quantum
information, we investigate separately the parametre reduction due to the
additional constraint of global purity, and the one following by the
local-unitary freedom. Counting arguments and insights from the phase-space
Schmidt decomposition and in general from the framework of symplectic analysis,
accompany our description of the standard form of pure n-mode Gaussian states.
In particular we clarify why only in pure states with n<=3 modes all the direct
correlations between position and momentum operators can be set to zero by
local unitary operations. For any n, the emerging minimal set of parametres
contains complete information about all forms of entanglement in the
corresponding states. An efficient state engineering scheme (able to encode
direct correlations between position and momentum operators as well) is
proposed to produce entangled multimode Gaussian resources, its number of
optical elements matching the minimal number of locally invariant degrees of
freedom of general pure n-mode Gaussian states. We demonstrate that so-called
"block-diagonal" Gaussian states, without direct correlations between position
and momentum, are systematically less entangled, on average, than arbitrary
pure Gaussian states.


title: Some problems of low-dimensional physics

abstract:
  Fermi and kinetic energy are usually calculated in periodic boundary
conditions model, which is not self-consistent for low-dimensional problems,
where particles are confined. Thus for confined particles the potential box
model was used self-consistently to calculate Fermi and kinetic energies in 3-,
2-, and 1-dimensional cases. This approach is much more logical and
self-consistent. Then the conditions for neglecting dimensions, that is
conditions under which the movement of particles in the box could be considered
as 2- and 1- dimensional, were derived.


title:
Bures distance as a measure of entanglement for symmetric two-mode
  Gaussian states

abstract:
  We evaluate a Gaussian entanglement measure for a symmetric two-mode Gaussian
state of the quantum electromagnetic field in terms of its Bures distance to
the set of all separable Gaussian states. The required minimization procedure
was considerably simplified by using the remarkable properties of the Uhlmann
fidelity as well as the standard form II of the covariance matrix of a
symmetric state. Our result for the Gaussian degree of entanglement measured by
the Bures distance depends only on the smallest symplectic eigenvalue of the
covariance matrix of the partially transposed density operator. It is thus
consistent to the exact expression of the entanglement of formation for
symmetric two-mode Gaussian states. This non-trivial agreement is specific to
the Bures metric.


title: Theory of Multidimensional Solitons

abstract:
  We review a number of topics germane to higher-dimensional solitons in
Bose-Einstein condensates. For dark solitons, we discuss dark band and planar
solitons; ring dark solitons and spherical shell solitons; solitary waves in
restricted geometries; vortex rings and rarefaction pulses; and multi-component
Bose-Einstein condensates. For bright solitons, we discuss instability,
stability, and metastability; bright soliton engineering, including pulsed atom
lasers; solitons in a thermal bath; soliton-soliton interactions; and bright
ring solitons and quantum vortices. A thorough reference list is included.


title: An upper bound for passive scalar diffusion in shear flows

abstract:
  This study is concerned with the diffusion of a passive scalar $\Theta(\r,t)$
advected by general $n$-dimensional shear flows $\u=u(y,z,...,t)\hat{x}$ having
finite mean-square velocity gradients. The unidirectionality of the
incompressible flows conserves the stream-wise scalar gradient,
$\partial_x\Theta$, allowing only the cross-stream components to be amplified
by shearing effects. This amplification is relatively weak because an important
contributing factor, $\partial_x\Theta$, is conserved, effectively rendering a
slow diffusion process. It is found that the decay of the scalar variance
$<\Theta^2>$ satisfies $d<\Theta^2>/dt\ge -C\kappa^{1/3}$, where $C>0$ is a
constant, depending on the fluid velocity gradients and initial distribution of
$\Theta$, and $\kappa$ is the molecular diffusivity. This result generalizes to
axisymmetric flows on the plane and on the sphere having finite mean-square
angular velocity gradients.


title: Enhanced Joule Heating in Umbral Dots

abstract:
  We present a study of magnetic profiles of umbral dots (UDs) and its
consequences on the Joule heating mechanisms. Hamedivafa (2003) studied Joule
heating using vertical component of magnetic field. In this paper UDs magnetic
profile has been investigated including the new azimuthal component of magnetic
field which might explain the relatively larger enhancement of Joule heating
causing more brightness near circumference of UD.


title: A primer on substitution tilings of the Euclidean plane

abstract:
  This paper is intended to provide an introduction to the theory of
substitution tilings. For our purposes, tiling substitution rules are divided
into two broad classes: geometric and combinatorial. Geometric substitution
tilings include self-similar tilings such as the well-known Penrose tilings;
for this class there is a substantial body of research in the literature.
Combinatorial substitutions are just beginning to be examined, and some of what
we present here is new. We give numerous examples, mention selected major
results, discuss connections between the two classes of substitutions, include
current research perspectives and questions, and provide an extensive
bibliography. Although the author attempts to fairly represent the as a whole,
the paper is not an exhaustive survey, and she apologizes for any important
omissions.


title: Exotic rational elliptic surfaces without 1-handles

abstract:
  Harer, Kas and Kirby have conjectured that every handle decomposition of the
elliptic surface $E(1)_{2,3}$ requires both 1- and 3-handles. In this article,
we construct a smooth 4-manifold which has the same Seiberg-Witten invariant as
$E(1)_{2,3}$ and admits neither 1- nor 3-handles, by using rational blow-downs
and Kirby calculus. Our manifold gives the first example of either a
counterexample to the Harer-Kas-Kirby conjecture or a homeomorphic but
non-diffeomorphic pair of simply connected closed smooth 4-manifolds with the
same non-vanishing Seiberg-Witten invariants.


title: Merger as Intermittent Accretion

abstract:
  The Self-Similar Secondary Infall Model (SSIM) is modified to simulate a
merger event. The model encompass spherical versions of tidal stripping and
dynamical friction that agrees with the Syer & White merger paradigm's
behaviour. The SSIM shows robustness in absorbing even comparable mass
perturbations and returning to its original state. It suggests the approach to
be invertible and allows to consider accretion as smooth mass inflow merging
and mergers as intermittent mass inflow accretion.


title: Lyman Break Galaxies at z~5: Rest-frame UV Spectra II

abstract:
  We present the results of spectroscopy of Lyman Break Galaxies (LBGs) at z~5
in the J0053+1234 field with the Faint Object Camera and Spectrograph on the
Subaru telescope. Among 5 bright candidates with z' < 25.0 mag, 2 objects are
confirmed to be at z~5 from their Ly alpha emission and the continuum
depression shortward of Ly alpha. The EWs of Ly alpha emission of the 2 LBGs
are not so strong to be detected as Ly alpha emitters, and one of them shows
strong low-ionized interstellar (LIS) metal absorption lines. Two faint objects
with z' \geq 25.0 mag are also confirmed to be at z~5, and their spectra show
strong Ly alpha emission in contrast to the bright ones. These results suggest
a deficiency of strong Ly alpha emission in bright LBGs at z~5, which has been
discussed in our previous paper. Combined with our previous spectra of LBGs at
z~5 obtained around the Hubble Deep Field-North (HDF-N), we made a composite
spectrum of UV luminous (M_1400 \leq -21.5 mag) LBGs at z~5. The resultant
spectrum shows a weak Ly alpha emission and strong LIS absorptions which
suggests that the bright LBGs at z~5 have chemically evolved at least to ~0.1
solar metallicity. For a part of our sample in the HDF-N region, we obtained
near-to-mid infrared data, which constraint stellar masses of these objects.
With the stellar mass and the metallicity estimated from LIS absorptions, the
metallicities of the LBGs at z~5 tend to be lower than those of the galaxies
with the same stellar mass at z \lesssim 2, although the uncertainty is very
large.


title:
Goldstone models in D+1 dimensions, D=3,4,5, supporting stable and zero
  topological charge solutions

abstract:
  We study finite energy static solutions to a global symmetry breaking
Goldstone model described by an isovector scalar field in D+1 spacetime
dimensions. Both topologically stable multisolitons with arbitrary winding
numbers, and zero topological charge soliton--antisoliton solutions are
constructed numerically in D=3,4,5. We have explored the types of symmetries
the systems should be subjected to, for there to exist multisoliton and
soliton--antisoliton pairs in D=3,4,5,6. These findings are underpinned by
constructing numerical solutions in the $D\le 5$ examples. Subject to axial
symmetry, only multisolitons of all topological charges exist in even D, and in
odd D, only zero and unit topological charge solutions exist. Subjecting the
system to weaker than axial symmetries, results in the existence of all the
possibilities in all dimensions. Our findings apply also to finite 'energy'
solutions to Yang--Mills and Yang-Mills--Higgs systems, and in principle also
sigma models.


title: Higher twist jet broadening and classical propagation

abstract:
  The transverse broadening of jets produced in deep-inelastic scattering (DIS)
off a large nucleus is studied in the collinear limit. A class of medium
enhanced higher twist corrections are re-summed to calculate the transverse
momentum distribution of the produced collinear jet. In contrast to previous
approaches, resummation of the leading length enhanced higher twist corrections
is shown to lead to a two dimensional diffusion equation for the transverse
momentum of the propagating jet. Results for the average transverse momentum
obtained from this approach are then compared to the broadening expected from a
classical Langevin analysis for the propagation of the jet under the action of
the fluctuating color Lorentz force inside the nucleons. The set of
approximations that lead to identical results from the two approaches are
outlined. The relationship between the momentum diffusion constant $D$ and the
transport coefficient $\hat{q}$ is explicitly derived.


title:
S\'eparation des Solutions aux Mod\`eles G\'eom\'etriques Direct et
  Inverse pour les Manipulateurs Pleinement Parall\`eles

abstract:
  This article provides a formalism making it possible to manage the solutions
of the direct and inverse kinematic models of the fully parallel manipulators.
We introduce the concept of working modes to separate the solutions from the
opposite geometrical model. Then, we define, for each working mode, the aspects
of these manipulators. To separate the solutions from the direct kinematics
model, we introduce the concept of characteristic surfaces. Then, we define the
uniqueness domains, as being the greatest domains of the workspace in which
there is unicity of solutions. The principal applications of this work are the
design, the trajectory planning.


title:
Radiation-pressure self-cooling of a micromirror in a cryogenic
  environment

abstract:
  We demonstrate radiation-pressure cavity-cooling of a mechanical mode of a
micromirror starting from cryogenic temperatures. To achieve that, a
high-finesse Fabry-Perot cavity (F\approx 2200) was actively stabilized inside
a continuous-flow 4He cryostat. We observed optical cooling of the fundamental
mode of a 50mu x 50 mu x 5.4 mu singly-clamped micromirror at \omega_m=3.5 MHz
from 35 K to approx. 290 mK. This corresponds to a thermal occupation factor of
<n>\approx 1x10^4. The cooling performance is only limited by the mechanical
quality and by the optical finesse of the system. Heating effects, e.g. due to
absorption of photons in the micromirror, could not be observed. These results
represent a next step towards cavity-cooling a mechanical oscillator into its
quantum ground state.


title: On the Kinetostatic Optimization of Revolute-Coupled Planar Manipulators

abstract:
  Proposed in this paper is a kinetostatic performance index for the optimum
dimensioning of planar manipulators of the serial type. The index is based on
the concept of distance of the underlying Jacobian matrix to a given isotropic
matrix that is used as a reference model for purposes of performance
evaluation. Applications of the index fall in the realm of design, but control
applications are outlined. The paper focuses on planar manipulators, the basic
concepts being currently extended to their three-dimensional counterparts.


title:
Achievable Rates and Optimal Resource Allocation for Imperfectly-Known
  Fading Relay Channels

abstract:
  In this paper, achievable rates of imperfectly-known fading relay channels
are studied. It is assumed that communication starts with the network training
phase in which the receivers estimate the fading coefficients of their
respective channels. In the data transmission phase, amplify-and-forward and
decode-and-forward relaying schemes are considered, and the corresponding
achievable rate expressions are obtained. The achievable rate expressions are
then employed to identify the optimal resource allocation strategies.


title:
The cyclic homology of monogenic extensions in the noncommutative
  setting

abstract:
  We study the Hochschild and cyclic homologies of noncommutative monogenic
extensions. As an aplication we compute the Hochschild and cyclic homologies of
the rank~1 Hopf algebras introduced by L. Krop and D. Radford in [Finite
dimensional Hopf algebras of rank 1 in characteristic 0, Journal of Algebra
302, no. 1, 214-230} (2006)].


title:
Optical Sky Brightness at Cerro Tololo Inter-American Observatory from
  1992 to 2006

abstract:
  We present optical UBVRI sky brightness measures from 1992 through 2006. The
data are based on CCD imagery obtained with the CTIO 0.9-m, 1.3-m, and 1.5-m
telescopes. The B- and V-band data are in reasonable agreement with
measurements previously made at Mauna Kea, though on the basis of a small
number of images per year there are discrepancies for the years 1992 through
1994. Our CCD-based data are not significantly different than values obtained
at Cerro Paranal. We find that the yearly averages of V-band sky brightness are
best correlated with the 10.7-cm solar flux taken 5 days prior to the sky
brightness measures. This implies an average speed of 350 km/sec for the solar
wind. While we can measure an enhancement of the night sky levels over La
Serena 10 degrees above the horizon, at elevation angles above 45 degrees we
find no evidence that the night sky brightness at Cerro Tololo is affected by
artificial light of nearby towns and cities.


title: Quark-lepton mass unification at TeV scales

abstract:
  A scenario combining a model of early (TeV) unification of quarks and leptons
with the physics of large extra dimensions provides a natural mechanism linking
quark and lepton masses at TeV scale. This has been dubbed as early
quark-lepton mass unification by one of us (PQH) in one of the two models of
early quark-lepton unification, which are consistent with data, namely SU(4)_PS
\otimes SU(2)_L \otimes SU(2)_R \otimes SU(2)_H. In particular, it focused on
the issue of naturally light Dirac neutrino. The present paper will focus on
similar issues in the other model, namely SU(4)_PS \otimes SU(3)_L \otimes
SU(3)_H.


title: State Vector Determination By A Single Tracking Satellite

abstract:
  Using only a single tracking satellite capable of only range measurements to
an orbiting object in an unknown Keplerian orbit, it is theoretically possible
to calculate the orbit and a current state vector. In this paper we derive an
algorithm that can perform this calculation.


title:
A soft-lithographed chaotic electrokinetic micromixer for efficient
  chemical reactions in lab-on-chips

abstract:
  Mixing is one of the basic functions which automated lab-on-chips require for
the effective management of liquid samples. In this paper we report on the
working principle, design, fabrication and experimental characterization of a
soft-lithographed micromixer for microfluidic applications. The device
effectively mixes two liquids by means of chaotic advection obtained as an
implementation of a Linked Twisted Map (LTM). In this sense it is chaotic. The
liquids are electrokinetically displaced by generating rolls through AC
electroosmosis on co-planar electrodes. The device performance has been tested
on dyed DI-water for several voltages, frequencies and flow-rates, displaying
good mixing properties in the range of $10 \div 100$kHz, at low peak-to-peak
voltages ($\sim15 \div 20$ volts). Low voltage supply, small dimensions and
possibility of fabrication via standard lithographic techniques make the device
highly integrable in lab-on-a-chip platforms.


title: Gravitino in six-dimensional warped supergravity

abstract:
  We consider the gravitino spectrum for the general warped solution in a
specific six-dimensional gauged supergravity. We find that although the brane
tensions introduced at the conical singularities break the bulk supersymmetry
explicitly, massless modes of gravitino can exist with a nontrivial wave
function profile, due to a nonzero U(1)_R gauge flux. We also compute the wave
function and the mass spectrum of Kaluza-Klein massive modes of the gravitino
explicitly. We show that the introduction of a gravitino mass term on a
regularized brane can give a suppressed effective gravitino mass compared to
the compactification scale, due to the delocalization of the wave function of
the zero-mode gravitino.


title: Models of f(R) Cosmic Acceleration that Evade Solar-System Tests

abstract:
  We study a class of metric-variation f(R) models that accelerates the
expansion without a cosmological constant and satisfies both cosmological and
solar-system tests in the small-field limit of the parameter space.
Solar-system tests alone place only weak bounds on these models, since the
additional scalar degree of freedom is locked to the high-curvature
general-relativistic prediction across more than 25 orders of magnitude in
density, out through the solar corona. This agreement requires that the
galactic halo be of sufficient extent to maintain the galaxy at high curvature
in the presence of the low-curvature cosmological background. If the galactic
halo and local environment in f(R) models do not have substantially deeper
potentials than expected in LCDM, then cosmological field amplitudes |f_R| >
10^{-6} will cause the galactic interior to evolve to low curvature during the
acceleration epoch. Viability of large-deviation models therefore rests on the
structure and evolution of the galactic halo, requiring cosmological
simulations of f(R) models, and not directly on solar-system tests. Even small
deviations that conservatively satisfy both galactic and solar-system
constraints can still be tested by future, percent-level measurements of the
linear power spectrum, while they remain undetectable to cosmological-distance
measures. Although we illustrate these effects in a specific class of models,
the requirements on f(R) are phrased in a nearly model-independent manner.


title: Ordering Finite-State Markov Channels by Mutual Information

abstract:
  In previous work, an ordering result was given for the symbolwise probability
of error using general Markov channels, under iterative decoding of LDPC codes.
In this paper, the ordering result is extended to mutual information, under the
assumption of an iid input distribution. For certain channels, in which the
capacity-achieving input distribution is iid, this allows ordering of the
channels by capacity. The complexity of analyzing general Markov channels is
mitigated by this ordering, since it is possible to immediately determine that
a wide class of channels, with different numbers of states, has a smaller
mutual information than a given channel.


title:
Towards a gauge invariant volume-weighted probability measure for
  eternal inflation

abstract:
  An improved volume-weighted probability measure for eternal inflation is
proposed. For the models studied in this paper it leads to simple and
intuitively expected gauge-invariant results.


title:
IDF revisited: A simple new derivation within the Robertson-Sp\"arck
  Jones probabilistic model

abstract:
  There have been a number of prior attempts to theoretically justify the
effectiveness of the inverse document frequency (IDF). Those that take as their
starting point Robertson and Sparck Jones's probabilistic model are based on
strong or complex assumptions. We show that a more intuitively plausible
assumption suffices. Moreover, the new assumption, while conceptually very
simple, provides a solution to an estimation problem that had been deemed
intractable by Robertson and Walker (1997).


title: Compactification in first order gravity

abstract:
  The Kaluza-Klein compactification process is applied in five dimensions to CS
gravity, for the anti-de Sitter and Poincar\'e groups, using the first order
formalism. In this context some solutions are found and analyzed. Also, the
conserved charges associated to the solutions are computed.


title:
Spinning straight cosmic strings with flat exterior solutions
  generically violate the weak energy condition

abstract:
  Any interior solution for a cylindrically symmetric, stationary cosmic string
with flat exterior, spinning around its longitudinal axis, and without internal
longitudinal currents ($g_{zz}=1$, $g_{tz}=0$), must somewhere violate the weak
energy condition of standard general relativity. Existing interior solutions
may be readily fixed by adding mass to the string above that generating its
angular deficit, but at the cost of introducing an exterior gravitational
field.


title: Spectral stability of periodic NLS and CGL solutions

abstract:
  We consider periodic traveling wave solutions to the focusing nonlinear
Schrodinger equation (NLS) that have been shown to persist when the NLS is
perturbed to the complex Ginzburg-Landau equation (CGL). In particular, we show
that these periodic traveling waves are spectrally stable solutions of NLS with
respect to periodic perturbations. Furthermore, we use an argument based on the
Fredholm alternative to find an instability criterion for the persisting
solutions to CGL.


title: Host Galaxy Bulge Predictors of Supermassive Black Hole Mass

abstract:
  A variety of host galaxy (bulge) parameters are examined in order to
determine their predictive power in ascertaining the masses of the supermassive
black holes (SMBH) at the centers of the galaxies. Based on a sample of 23
nearby galaxies, comprised of both elliptical galaxies and spiral/lenticular
bulges, we identify a strong correlation between the bulge gravitational
binding energy ($E_g$), as traced by the stellar light profile, and the SMBH
mass ($M_{\bullet}$), such that $M_{\bullet} \propto E_g^{0.6}$. The scatter
about the relationship indicates that this is as strong a predictor of
$M_{\bullet}$ as the velocity dispersion ($\sigma$), for the elliptical galaxy
subsample. Improved mass-to-light ratios, obtained with IFU spectroscopy and
I-band photometry by the SAURON group, were used for those sample galaxies
where available, resulting in an energy predictor with the same slope, but with
reduced scatter. Alternative $M_{\bullet}$ predictors such as the gravitational
potential and the bulge mass are also explored, but these are found to be
inferior when compared with both the bulge gravitational binding energy and
bulge velocity dispersion predictors, for the full galaxy sample.


title: A new approach to resummation: Parametric Perturbation Theory

abstract:
  We present a {\sl non--perturbative} method, called {\sl Parametric
Perturbation Theory} (PPT), which is alternative to the ordinary perturbation
theory. The method relies on a principle of simplicity for the observable
solutions, which are constrained to be linear in a certain (unphysical)
parameter. The perturbative expansion is carried out in this parameter and not
in the physical coupling (as in ordinary perturbation theory). We show that the
method is capable to resum the divergent perturbative series, to {\sl extract}
the leading asymptotic (strong coupling) behavior and {\sl predict} with high
accuracy the coefficients of the perturbative series.


title: Creating Statistically Anisotropic and Inhomogeneous Perturbations

abstract:
  In almost all structure formation models, primordial perturbations are
created within a homogeneous and isotropic universe, like the one we observe.
Because their ensemble averages inherit the symmetries of the spacetime in
which they are seeded, cosmological perturbations then happen to be
statistically isotropic and homogeneous. Certain anomalies in the cosmic
microwave background on the other hand suggest that perturbations do not
satisfy these statistical properties, thereby challenging perhaps our
understanding of structure formation. In this article we relax this tension. We
show that if the universe contains an appropriate triad of scalar fields with
spatially constant but non-zero gradients, it is possible to generate
statistically anisotropic and inhomogeneous primordial perturbations, even
though the energy momentum tensor of the triad itself is invariant under
translations and rotations.


title: Going beyond perturbation theory: Parametric Perturbation Theory

abstract:
  We devise a {\sl non--perturbative} method, called {\sl Parametric
Perturbation Theory} (PPT), which is alternative to the ordinary perturbation
theory. The method relies on a principle of simplicity for the observable
solutions, which are constrained to be linear in a certain (unphysical)
parameter. The perturbative expansion is carried out in this parameter and not
in the physical coupling (as in ordinary perturbation theory). We provide a
number of nontrivial examples, where our method is capable to resum the
divergent perturbative series, {\sl extract} the leading asymptotic (strong
coupling) behavior and {\sl predict} with high accuracy the coefficients of the
perturbative series. In the case of a zero dimensional field theory we prove
that PPT can be used to provide the imaginary part of the solution, when the
problem is analytically continued to negative couplings. In the case of a
$\phi^4$ lattice model 1+1 and of elastic theory we have shown that the
observables resummed with PPT display a branch point at a finite value of the
coupling, signaling the transition from a stable to a metastable state. We have
also applied the method to the prediction of the virial coefficients for a hard
sphere gas in two and three dimensions; in this example we have also found that
the solution resummed with PPT has a singularity at finite density. Predictions
for the unknown virial coefficients are made.


title: Frustration Effects in Antiferromagnetic FCC Heisenberg Films

abstract:
  We study the effects of frustration in an antiferromagnetic film of FCC
lattice with Heisenberg spin model including an Ising-like anisotropy. Monte
Carlo (MC) simulations have been used to study thermodynamic properties of the
film. We show that the presence of the surface reduces the ground state (GS)
degeneracy found in the bulk. The GS is shown to depend on the surface in-plane
interaction $J_s$ with a critical value at which ordering of type I coexists
with ordering of type II. Near this value a reentrant phase is found. Various
physical quantities such as layer magnetizations and layer susceptibilities are
shown and discussed. The nature of the phase transition is also studied by
histogram technique. We have also used the Green's function (GF) method for the
quantum counterpart model. The results at low-$T$ show interesting effects of
quantum fluctuations. Results obtained by the GF method at high $T$ are
compared to those of MC simulations. A good agreement is observed.


title: The Collision Between The Milky Way And Andromeda

abstract:
  We use a N--body/hydrodynamic simulation to forecast the future encounter
between the Milky Way and the Andromeda galaxies, given current observational
constraints on their relative distance, relative velocity, and masses. Allowing
for a comparable amount of diffuse mass to fill the volume of the Local Group,
we find that the two galaxies are likely to collide in a few billion years -
within the Sun's lifetime. During the the interaction, there is a chance that
the Sun will be pulled away from its present orbital radius and reside in an
extended tidal tail. The likelihood for this outcome increases as the merger
progresses, and there is a remote possibility that our Sun will be more tightly
bound to Andromeda than to the Milky Way before the final merger. Eventually,
after the merger has completed, the Sun is most likely to be scattered to the
outer halo and reside at much larger radii (>30 kpc). The density profiles of
the stars, gas and dark matter in the merger product resemble those of
elliptical galaxies. Our Local Group model therefore provides a prototype
progenitor of late--forming elliptical galaxies.


title: Cusp Algebras

abstract:
  We consider simple cusp algebras, that is certain subalgebras of the algebra
of holomorphic functions on a disk that are annihilated by some distributions
living on a singleton. We determine when these algebras can be holized in two
dimensions, and when these holizations are globally biholomorphic.


title:
Remarks on a paper by Cordero and Nicola on Feichtinger's Wiener amalgam
  spaces and the Schroedinger equation

abstract:
  We derive some consequences of very recent results of Cordero and Nicola on
the metaplectic representation, the Wiener amalgam spaces, (whose definition is
due to Feichtinger), and their applications to the regularity of the solutions
of Schroedinger equation with quadratic Weyl symbol. We do not however discuss
the validity of Cordero and Nicola's claims.


title: Effective Physical Processes and Active Information in Quantum Computing

abstract:
  The recent debate on hypercomputation has arisen new questions both on the
computational abilities of quantum systems and the Church-Turing Thesis role in
Physics. We propose here the idea of "effective physical process" as the
essentially physical notion of computation. By using the Bohm and Hiley active
information concept we analyze the differences between the standard form
(quantum gates) and the non-standard one (adiabatic and morphogenetic) of
Quantum Computing, and we point out how its Super-Turing potentialities derive
from an incomputable information source in accordance with Bell's constraints.
On condition that we give up the formal concept of "universality", the
possibility to realize quantum oracles is reachable. In this way computation is
led back to the logic of physical world.


title: Bose Fluids Above Tc: Incompressible Vortex Fluids and "Supersolidity"

abstract:
  This paper emphasizes that non-linear rotational or diamagnetic
susceptibility is characteristic of Bose fluids above their superfluid Tcs, and
for sufficiently slow rotation or weak B-fields amounts to an incompressible
response to vorticity. The cause is a missing term in the conventionally
accepted model Hamiltonian for quantized vortices in the Bose fluid. The
resulting susceptibility can account for recent observations of Chan et al on
solid He, and Ong et al on cuprate superconductors.


title: Ensemble averageability in network spectra

abstract:
  The extreme eigenvalues of connectivity matrices govern the influence of the
network structure on a number of network dynamical processes. A fundamental
open question is whether the eigenvalues of large networks are well represented
by ensemble averages. Here we investigate this question explicitly and validate
the concept of ensemble averageability in random scale-free networks by showing
that the ensemble distributions of extreme eigenvalues converge to peaked
distributions as the system size increases. We discuss the significance of this
result using synchronization and epidemic spreading as example processes.

categories: cond-mat.stat-mech cond-mat.dis-nn nlin.AO nlin.CD


title: Bases invariantes de friabilit\'e

abstract:
  Given a finite residue field
  $k$, one looks for a smoothness basis that is invariant under the
automorphism group of $k$. We construct models for some finite fields that
admit such a basis. This work aims at accelerating algorithms for computing
discrete logarithms in some finite residue fields.


title: The Group of Hamiltonian Homeomorphisms in the L^\infty-norm

abstract:
  The group Hameo (M,\omega) of Hamiltonian homeomorphisms of a connected
symplectic manifold (M,\omega) was defined and studied in [7] and further in
[6]. In these papers, the authors consistently used the L^{(1,\infty)}-Hofer
norm (and not the L^\infty-Hofer norm) on the space of Hamiltonian paths (see
below for the definitions). A justification for this choice was given in [7].
In this article we study the L^\infty-case. In view of the fact that the Hofer
norm on the group Ham (M,\omega) of Hamiltonian diffeomorphisms does not depend
on the choice of the L^{(1,\infty)}-norm vs. the L^\infty-norm [9], Y.-G. Oh
and D. McDuff (private communications) asked whether the two notions of
Hamiltonian homeomorphisms arising from the different norms coincide. We will
give an affirmative answer to this question in this paper.


title: A global picture of quantum de Sitter space

abstract:
  Perturbative gravity about a de Sitter background motivates a global picture
of quantum dynamics in `eternal de Sitter space,' the theory of states which
are asymptotically de Sitter to both future and past. Eternal de Sitter physics
is described by a finite dimensional Hilbert space in which each state is
precisely invariant under the full de Sitter group. This resolves a
previously-noted tension between de Sitter symmetry and finite entropy.
Observables, implications for Boltzmann brains, and Poincare recurrences are
briefly discussed.


title: Analytic Study of Rotating Black-Hole Quasinormal Modes

abstract:
  A Bohr-Sommerfeld equation is derived for the highly-damped quasinormal mode
frequencies omega(n>>1) of rotating black holes. It may be written as
2\int_C(p_r+ip_0)dr=(n+1/2)h, where p_r is the canonical momentum conjugate to
the radial coordinate r along null geodesics of energy hbar*omega and angular
momentum hbar*m, p_0=O(omega^0), and the contour C connects two complex turning
points of p_r. The solutions are omega(n) = - m*omega_0 - i(phi + n*delta),
where {omega_0,delta}>0 are functions of the black-hole parameters alone. Some
physical implications are discussed.


title: A PromiseBQP-complete String Rewriting Problem

abstract:
  We are given three strings s, t, and t' of length L over some fixed finite
alphabet and an integer m that is polylogarithmic in L. We have a symmetric
relation on substrings of constant length that specifies which substrings are
allowed to be replaced with each other. Let Delta(n) denote the difference
between the numbers of possibilities to obtain t from s and t' from s after n
replacements. The problem is to determine the sign of Delta(m).
  As promises we have a gap condition and a growth condition. The former states
that |Delta(m)| >= epsilon c^m where epsilon is inverse polylogarithmic in L
and c>0 is a constant. The latter is given by Delta(n) <= c^n for all n.
  We show that this problem is PromiseBQP-complete, i.e., it represents the
class of problems which can be solved efficiently on a quantum computer.


title:
Nonleptonic two-body B-decays including axial-vector mesons in the final
  state

abstract:
  We present a systematic study of exclusive charmless nonleptonic two-body B
decays including axial-vector mesons in the final state. We calculate branching
ratios of B\to PA, VA and AA decays, where A, V and P denote an axial-vector, a
vector and a pseudoscalar meson, respectively. We assume naive factorization
hypothesis and use the improved version of the nonrelativistic ISGW quark model
for form factors in B\to A transitions. We include contributions that arise
from the effective \Delta B=1 weak Hamiltonian H_{eff}. The respective
factorized amplitude of these decays are explicitly showed and their penguin
contributions are classified. We find that decays B^-to a_1^0\pi^-,\barB^0\to
a_1^{\pm}\pi^{\mp}, B^-\to a_1^-\bar K^0, \bar B^0\to a_1^+K^-, \bar B^0\to
f_1\bar K^0, B^-\to f_1K^-, B^-\to K_1^-(1400)\etap, B^-\to b_1^-\bar K^{0},
and \bar B^0\to b_1^+\pi^-(K^-) have branching ratios of the order of 10^{-5}.
We also study the dependence of branching ratios for B \to K_1P(V,A) decays
(K_1=K_1(1270),K_1(1400)) with respect to the mixing angle between K_A and K_B.


title: Pure states on free group C*-algebras

abstract:
  We prove that all of the pure states of the reduced C*-algebra of the free
goup on $\aleph_1$ generators are *-automorphism equivalent and extract some
consequences of that fact.


title: Multiple Antenna Secure Broadcast over Wireless Networks

abstract:
  In wireless data networks, communication is particularly susceptible to
eavesdropping due to its broadcast nature. Security and privacy systems have
become critical for wireless providers and enterprise networks. This paper
considers the problem of secret communication over the Gaussian broadcast
channel, where a multi-antenna transmitter sends independent confidential
messages to two users with perfect secrecy. That is, each user would like to
obtain its own message reliably and confidentially. First, a computable
Sato-type outer bound on the secrecy capacity region is provided for a
multi-antenna broadcast channel with confidential messages. Next, a dirty-paper
secure coding scheme and its simplified version are described. For each case,
the corresponding achievable rate region is derived under the perfect secrecy
requirement. Finally, two numerical examples demonstrate that the Sato-type
outer bound is consistent with the boundary of the simplified dirty-paper
coding secrecy rate region.


title: Puzzles, Tableaux and Mosaics

abstract:
  We define mosaics, which are naturally in bijection with Knutson-Tao puzzles.
We define an operation on mosaics, which shows they are also in bijection with
Littlewood-Richardson skew-tableaux. Another consequence of this construction
is that we obtain bijective proofs of commutativity and associativity for the
ring structures defined either of these objects. In particular, we obtain a
new, easy proof of the Littlewood-Richardson rule. Finally we discuss how our
operation is related to other known constructions, particularly jeu de taquin.


title: Observation of Landau levels of Dirac fermions in graphite

abstract:
  The low energy electronic excitations in single layer and bilayer graphite
(graphene) resemble quantum-relativistic particles also known as Dirac Fermions
(DF). They possess an internal degree of freedom, chirality, that leads to
unusual Landau Level (LL) energy sequences in a magnetic field and profoundly
alters the magneto-transport properties. One of the consequences is an
anomalous Quantum-Hall effect, recently detected in both single layer and
bi-layer graphene. However the underlying cause, the unusual LL sequence, was
never observed. Here we report the direct observation of LL of DF by means of
low temperature Scanning-Tunnelling-Spectroscopy (STS) on the surface of
graphite in fields up to 12 Tesla. We find evidence of coexistence of massless
and massive DF, and identify the zero-energy LL which is a unique consequence
of their quantum-relativistic nature. Surprisingly these strictly
two-dimensional properties emerge even on bulk graphite in samples where the
interlayer coupling is weak.


title:
The Search for Muon Neutrinos from Northern Hemisphere Gamma-Ray Bursts
  with AMANDA

abstract:
  We present the results of the analysis of neutrino observations by the
Antarctic Muon and Neutrino Detector Array (AMANDA) correlated with photon
observations of more than 400 gamma-ray bursts (GRBs) in the Northern
Hemisphere from 1997 to 2003. During this time period, AMANDA's effective
collection area for muon neutrinos was larger than that of any other existing
detector. Based on our observations of zero neutrinos during and immediately
prior to the GRBs in the dataset, we set the most stringent upper limit on muon
neutrino emission correlated with gamma-ray bursts. Assuming a Waxman-Bahcall
spectrum and incorporating all systematic uncertainties, our flux upper limit
has a normalization at 1 PeV of
  E^2{\Phi}_{\nu} {\leq} 6.0 \times 10^{-9} GeV cm^{-2} s^{-1} sr^{-1}, with
90% of the events expected within the energy range of ~10 TeV to ~3 PeV. The
impact of this limit on several theoretical models of GRBs is discussed, as
well as the future potential for detection of GRBs by next generation neutrino
telescopes. Finally, we briefly describe several modifications to this analysis
in order to apply it to other types of transient point sources.


title:
Symbol Error Rates of Maximum-Likelihood Detector: Convex/Concave
  Behavior and Applications

abstract:
  Convexity/concavity properties of symbol error rates (SER) of the maximum
likelihood detector operating in the AWGN channel (non-fading and fading) are
studied. Generic conditions are identified under which the SER is a
convex/concave function of the SNR. Universal bounds for the SER 1st and 2nd
derivatives are obtained, which hold for arbitrary constellations and are tight
for some of them. Applications of the results are discussed, which include
optimum power allocation in spatial multiplexing systems, optimum power/time
sharing to decrease or increase (jamming problem) error rate, and implication
for fading channels.


title: Neutrino Masses in the Lee-Wick Standard Model

abstract:
  Recently, an extension of the standard model based on ideas of Lee and Wick
has been discussed. This theory is free of quadratic divergences and hence has
a Higgs mass that is stable against radiative corrections. Here, we address the
question of whether or not it is possible to couple very heavy particles, with
masses much greater than the weak scale, to the Lee-Wick standard model degrees
of freedom and still preserve the stability of the weak scale. We show that in
the LW-standard model the familiar see-saw mechanism for generating neutrino
masses preserves the solution to the hierarchy puzzle provided by the higher
derivative terms. The very heavy right handed neutrinos do not destabilize the
Higgs mass. We give an example of new heavy degrees of freedom that would
destabilize the hierarchy, and discuss a general mechanism for coupling other
heavy degrees of freedom to the Higgs doublet while preserving the hierarchy.


title:
Hot Nights on Extrasolar Planets: Mid-IR Phase Variations of Hot
  Jupiters

abstract:
  We present results from Spitzer Space Telescope observations of the
mid-infrared phase variations of three short-period extrasolar planetary
systems: HD 209458, HD 179949 and 51 Peg. We gathered IRAC images in multiple
wavebands at eight phases of each planet's orbit. We find the uncertainty in
relative photometry from one epoch to the next to be significantly larger than
the photon counting error at 3.6 micron and 4.5 micron. We are able to place
2-sigma upper limits of only 2% on the phase variations at these wavelengths.
At 8 micron the epoch-to-epoch systematic uncertainty is comparable to the
photon counting noise and we detect a phase function for HD 179949 which is in
phase with the planet's orbit and with a relative peak-to-trough amplitude of
0.00141(33). Assuming that HD 179949b has a radius R_J < R_p < 1.2R_J, it must
recirculate less than 21% of incident stellar energy to its night side at the
1-sigma level (where 50% signifies full recirculation). If the planet has a
small Bond albedo, it must have a mass less than 2.4 M_J (1-sigma). We do not
detect phase variations for the other two systems but we do place the following
2-sigma upper limits: 0.0007 for 51 Peg, and 0.0015 for HD 209458. Due to its
edge-on configuration, the upper limit for HD 209458 translates, with
appropriate assumptions about Bond albedo, into a lower limit on the
recirculation occuring in the planet's atmosphere. HD 209458b must recirculate
at least 32% of incident stellar energy to its night side, at the 1-sigma
level, which is consistent with other constraints on recirculation from the
depth of secondary eclipse depth at 8 micron and the low optical albedo. These
data indicate that different Hot Jupiter planets may experience different
recirculation efficiencies.


title: Measurement of CP-Violating Asymmetries in B0->D(*)+D-

abstract:
  We present updated measurements of \CP-violating asymmetries in the decays
$\Bz\to\Dstarpm\Dmp$ and $\Bz\to\Dp\Dm$ using $(383\pm 4) \times 10^{6} \BB$
pairs collected by the \babar detector at the PEP-II $B$ factory. We determine
the time-integrated \CP asymmetry ${\mathcal{A}}_{\Dstarpm\Dmp}=0.12\pm 0.06\pm
0.02$, and the time-dependent asymmetry parameters to be $C_{\Dstarp\Dm}
=0.18\pm 0.15\pm 0.04$, $S_{\Dstarp\Dm}=-0.79\pm 0.21\pm 0.06$, $C_{\Dstarm\Dp}
=0.23\pm 0.15\pm 0.04$, $S_{\Dstarm\Dp} =-0.44\pm 0.22\pm 0.06$, $C_{\Dp\Dm}
=0.11\pm 0.22\pm 0.07$, and $S_{\Dp\Dm} =-0.54\pm 0.34\pm 0.06$, where the
first uncertainty is statistical and the second is systematic.


title: Improved Quantum Hard-Sphere Ground-State Equations of State

abstract:
  The London ground-state energy formula as a function of number density for a
system of identical boson hard spheres, corrected for the reduced mass of a
pair of particles in a sphere-of-influence picture, and generalized to fermion
hard-sphere systems with two and four intrinsic degrees of freedom, has a
double-pole at the ultimate \textit{regular} (or periodic, e.g.,
face-centered-cubic) close-packing density usually associated with a
crystalline branch. Improved fluid branches are contructed based upon exact,
field-theoretic perturbation-theory low-density expansions for many-boson and
many-fermion systems, appropriately extrapolated to intermediate densities, but
whose ultimate density is irregular or \textit{random} closest close-packing as
suggested in studies of a classical system of hard spheres. Results show
substantially improved agreement with the best available Green-function Monte
Carlo and diffusion Monte Carlo simulations for bosons, as well as with ladder,
variational Fermi hypernetted chain, and so-called L-expansion data for
two-component fermions.


title: Indian Cosmological Ideas

abstract:
  This paper, third in the series on Indian tradition of physics, describes
conceptions of the cosmos with ideas that are clearly spelt out in texts such
as Yoga Vasishtha.In particular, the conception of multiple universes that
occurs often in this text will be examined in the framework of the Indian
physics. The other surprising concepts that are discussed include flow of time
and its variability with respect to different observers, and the possibility of
passage across universes.


title: The Quantum Interference Effect Transistor: Principles and Perspectives

abstract:
  We give a detailed discussion of the Quantum Interference Effect Transistor
(QuIET), a proposed device which exploits interference between electron paths
through aromatic molecules to modulate current flow. In the off state, perfect
destructive interference stemming from the molecular symmetry blocks current,
while in the on state, current is allowed to flow by locally introducing either
decoherence or elastic scattering. Details of a model calculation demonstrating
the efficacy of the QuIET are presented, and various fabrication scenarios are
proposed, including the possibility of using conducting polymers to connect the
QuIET with multiple leads.


title: Deflection of Slow Light by Magneto-Optically Controlled Atomic Media

abstract:
  We present a semi-classical theory for light deflection by a coherent
$\Lambda$-type three-level atomic medium in an inhomogeneous magnetic field or
an inhomogeneous control laser. When the atomic energy levels (or the Rabi
coupling by the control laser) are position-dependent due to the Zeeman effect
by the inhomogeneous magnetic field (or the inhomogeneity of the control field
profile), the spatial dependence of the refraction index of the atomic medium
will result in an observable deflection of slow signal light when the
electromagnetically induced transparency happens to avoid medium absorption.
Our theoretical approach based on Fermat's principle in geometrical optics not
only provides a consistent explanation for the most recent experiment in a
straightforward way, but also predicts the new effects for the slow signal
light deflection by the atomic media in an inhomogeneous off-resonant control
laser field.


title:
Comprehensive Calculations on the OZI-forbidden Nonleptonic Decays of
  Orthoquarkonia $J/\psi(\Upsilon)\to \pi\pi,\rho\pi$

abstract:
  In this work, we calculate the decay rates of the OZI-forbidden processes
$J/\psi(\Upsilon)\to \pi\pi, \rho\pi$ at the order of the leading-twist
distribution amplitude. The process of $J/\psi(\Upsilon)\to \pi^+ \pi^-$
violates isospin conservation and the amplitude is explicitly proportional to
the isospin violation factor $m_u-m_d$, our numerical results on their decay
rates are consistent with the data. The process $J/\psi(\Upsilon)\to \rho\pi$
violates the hadronic helicity conservation and should be suppressed, as
indicated in literature, its decay rate can only be proportional to $m_q^2$ at
the order of leading twist. Our theoretical evaluation confirms this statement
that the theoretical evaluation on $\Gamma(J/\psi(\Upsilon)\to \rho\pi)$ is
almost one order smaller than the data unless the model parameters take certain
extreme values. It may imply that the sizable branching ratio of
$J/\psi(\Upsilon)\to \rho\pi$ should be explained by either higher twist
contributions or other mechanisms.


title:
Effects of a multi-quark interaction on color superconducting phase
  transition in an extended NJL model

abstract:
  We study the interplay of the chiral and the color superconducting phase
transitions in an extended Nambu--Jona-Lasinio model with a multi-quark
interaction that produces the nonlinear chiral-diquark coupling. We observe
that this nonlinear coupling adds up coherently with the \omega^2 interaction
to produce the chiral-color superconductivity coexistence phase or cancel each
other depending on its sign. We discuss that large coexistence region in the
phase diagram is consistent with the quark-diquark picture for the nucleon
whereas its smallness is the prerequisite for the applicability of the
Ginzburg-Landau approach.


title:
Passive Cooling of a Micromechanical Oscillator with a Resonant Electric
  Circuit

abstract:
  We cool the fundamental mode of a miniature cantilever by capacitively
coupling it to a driven rf resonant circuit. Cooling results from the rf
capacitive force, which is phase shifted relative to the cantilever motion. We
demonstrate the technique by cooling a 7 kHz cantilever from room temperature
to 45 K, obtaining reasonable agreement with a model for the cooling, damping,
and frequency shift. Extending the method to higher frequencies in a cryogenic
system could enable ground state cooling and may prove simpler than related
optical experiments in a low temperature apparatus.


title:
Measured oscillations of the velocity and temperature fields in
  turbulent Rayleigh-B\'{e}nard convection in a rectangular cell

abstract:
  Temperature and velocity oscillations have been found in a rectangular
Rayleigh-B\'{e}nard convection cell, in which one large scale convection roll
exists. At $Ra=8.9 \times 10^{11}$ and $Pr=4$, temperature oscillation can be
observed in most part of the system and the oscillation period remains almost
constant, $t_T = 74 \pm 2$ seconds. Velocity oscillation can only be found in
its horizontal component, $v_y$ (perpendicular to large scale circulation
plane), near the cell sidewall, its oscillation period is also constant, $t_T =
65 \pm 2$ seconds, at these positions. Temperature and velocity oscillations
have different Ra dependence, which are respectively indicated by Peclect
number $Pe_T = 0.55Ra^{0.47}$ and $Pe_v = 0.28Ra^{0.50}$ . In comparison to the
case of cylindrical cell, we find that the velocity oscillation is affected by
the system geometry.


title: A transcendental approach to Koll\'ar's injectivity theorem II

abstract:
  We treat a relative version of the main theorem in my previous paper: A
transcendental approach to Koll\'ar's injectivity theorem. More explicitly, we
give a curvature condition that implies Koll\'ar type cohomology injectivity
theorems in the relative setting. To carry out this generalization, we use the
Ohsawa-Takegoshi twisted version of Nakano's identity.


title: Cosmological Constraints on Neutrino Injection

abstract:
  We derive general constraints on the relic abundances of a long-lived
particle which mainly decays into a neutrino (and something else) at
cosmological time scales. Such an exotic particle may show up in various
particle-physics models based on physics beyond the standard model. The
constraints are obtained from big-bang nucleosynthesis, cosmic microwave
background and diffuse neutrino and photon fluxes, depending on the lifetime
and the electromagnetic and hadronic branching ratios.


title: Asymmetric superconductivity in metallic systems

abstract:
  Different types of superfluid ground states have been investigated in systems
of two species of fermions with Fermi surfaces that do not match. This study is
relevant for cold atomic systems, condensed matter physics and quark matter. In
this paper we consider this problem in the case the fermionic quasi-particles
can transmute into one another and only their total number is conserved. We use
a BCS approximation to study superconductivity in two-band metallic systems
with inter and intra-band interactions. Tuning the hybridization between the
bands varies the mismatch of the Fermi surfaces and produces different
instabilities. For inter-band attractive interactions we find a first order
normal-superconductor and a homogeneous metastable phase with gapless
excitations. In the case of intra-band interactions, the transition from the
superconductor to the normal state as hybridization increases is continuous and
associated with a quantum critical point. The case when both interactions are
present is also considered.

categories: cond-mat.supr-con astro-ph cond-mat.stat-mech cond-mat.str-el hep-th


title:
Deflection of High-Energy Cosmic Radiation Ions using a Bent Crystal
  Shield

abstract:
  A bent crystal shield which is capable of deflecting cosmic radiation ions of
all atomic numbers away from spacecraft using the ion channeling effect is
described. Its effect on the transmitted angular distribution of heavy,
high-energy ions is characterized using Monte Carlo channeling simulations.
Ions up to an energy limit set by the bent crystal curvature radius are
deflected by the full curvature angle. A bent crystal shield with a 1 x 1 cm2
surface area capable of deflecting such ions with energies up to 100
GeV/nucleon is fabricated in which the lattice planes across the entrance
surface are uniformly aligned.


title: Highest-Weight Theory for Truncated Current Lie Algebras

abstract:
  Let g denote a Lie algebra over a field of characteristic zero, and let T(g)
denote the tensor product of g with a ring of truncated polynomials. The Lie
algebra T(g) is called a truncated current Lie algebra, or in the special case
when g is finite-dimensional and semisimple, a generalized Takiff algebra. In
this paper a highest-weight theory for T(g) is developed when the underlying
Lie algebra g possesses a triangular decomposition. The principal result is the
reducibility criterion for the Verma modules of T(g) for a wide class of Lie
algebras g, including the symmetrizable Kac-Moody Lie algebras, the Heisenberg
algebra, and the Virasoro algebra. This is achieved through a study of the
Shapovalov form.


title:
Electron-Hole Generation and Recombination Rates for Coulomb Scattering
  in Graphene

abstract:
  We calculate electron-hole generation and recombination rates for Coulomb
scattering (Auger recombination and impact ionization) in Graphene. The
conduction and valence band dispersion relation in Graphene together with
energy and momentum conservation requirements restrict the phase space for
Coulomb scattering so that electron-hole recombination times can be much longer
than 1 ps for electron-hole densities smaller than $10^{12}$ cm$^{-2}$.


title:
Photoluminescence Spectroscopy of the Molecular Biexciton in Vertically
  Stacked Quantum Dot Pairs

abstract:
  We present photoluminescence studies of the molecular neutral
biexciton-exciton spectra of individual vertically stacked InAs/GaAs quantum
dot pairs. We tune either the hole or the electron levels of the two dots into
tunneling resonances. The spectra are described well within a few-level,
few-particle molecular model. Their properties can be modified broadly by an
electric field and by structural design, which makes them highly attractive for
controlling nonlinear optical properties.


title:
The SSS phase of RS Ophiuchi observed with Chandra and XMM-Newton I.:
  Data and preliminary Modeling

abstract:
  The phase of Super-Soft-Source (SSS) emission of the sixth recorded outburst
of the recurrent nova RS Oph was observed twice with Chandra and once with
XMM-Newton. The observations were taken on days 39.7, 54.0, and 66.9 after
outburst. We confirm a 35-sec period on day 54.0 and found that it originates
from the SSS emission and not from the shock. We discus the bound-free
absorption by neutral elements in the line of sight, resonance absorption lines
plus self-absorbed emission line components, collisionally excited emission
lines from the shock, He-like intersystem lines, and spectral changes during an
episode of high-amplitude variability. We find a decrease of the oxygen K-shell
absorption edge that can be explained by photoionization of oxygen. The
absorption component has average velocities of -1286+-267 km/s on day 39.7 and
of -771+-65 km/s on day 66.9. The wavelengths of the emission line components
are consistent with their rest wavelengths as confirmed by measurements of
non-self absorbed He-like intersystem lines. We have evidence that these lines
originate from the shock rather than the outer layers of the outflow and may be
photoexcited in addition to collisional excitations. We found collisionally
excited emission lines that are fading at wavelengths shorter than 15A that
originate from the radiatively cooling shock. On day 39.5 we find a systematic
blue shift of -526+-114 km/s from these lines. We found anomalous He-like f/i
ratios which indicates either high densities or significant UV radiation near
the plasma where the emission lines are formed. During the phase of strong
variability the spectral hardness light curve overlies the total light curve
when shifted by 1000sec. This can be explained by photoionization of neutral
oxygen in the line of sight if the densities of order 10^{10}-10^{11} cm^{-3}.


title: Comment on "On Mach's critique of Newton and Copernicus"

abstract:
  Hartman and Nissim-Sabat have argued that Mach's idea of the relativity of
rotational motion suffers from internal inconsistencies and leads to a
contradiction that there cannot be a stationary bucket in a rotating universe.
They also claimed that non-inertial electromagnetic and stellar aberration
observations can distinguish between a rotating and a stationary universe,
whereas according to Mach there cannot be any observable way to distinguish
these two cases. We contest these objections.