title: Vibration diagnostics instrumentation for ILC

abstract:
  The future e-e+ 500 GeV International Linear Collider will rely on
unprecedented nanometer scale particle beam size at the interaction point, in
order to achieve the design luminosity. Tight tolerances on static and dynamic
alignment of the accelerator cavities and optical components are demanded to
transport and focus the high energy electron and positron beams with reasonable
position jitter and low emittance. A brief review of techniques and devices
evaluated and developed so far for the vibration diagnostics of the machine is
presented in this paper.


title: Performance limits of graphene-ribbon-based field effect transistors

abstract:
  The performance of field effect transistors based on an single graphene
ribbon with a constriction and a single back gate are studied with the help of
atomistic models. It is shown how this scheme, unlike that of traditional
carbon-nanotube-based transistors, reduces the importance of the specifics of
the chemical bonding to the metallic electrodes in favor of the carbon-based
part of device. The ultimate performance limits are here studied for various
constriction and metal-ribbon contact models. In particular we show that, even
for poorly contacting metals, properly taylored constrictions can give
promising values for both the on-conductance and the subthreshold swing.


title:
Self Improving Sobolev-Poincare Inequalities, Truncation and
  Symmetrization

abstract:
  In a previous paper we developed a new method to obtain symmetrization
inequalities of Sobolev type for functions in $W_{0}^{1,1}(\Omega)$. In this
paper we extend our method to Sobolev functions that do not vanish at the
boundary.


title: Analysis of Emission Shapes

abstract:
  Shapes of relative emission sources can be accessed by expanding shapes of
correlations at low relative velocities in pair center of mass in Cartesian
harmonics. Coefficients of expansion for correlations are related to the
respective coefficients of expansion for the sources through one dimensional
integral transforms involving properties of pair relative wavefunctions. The
methodology is illustrated with analyses of NA49 and PHENIX correlation data.


title:
CP violation in scatterings, three body processes and the Boltzmann
  equations for leptogenesis

abstract:
  We obtain the Boltzmann equations for leptogenesis including decay and
scattering processes with two and three body initial or final states. We
present an explicit computation of the CP violating scattering asymmetries. We
analyze their possible impact in leptogenesis, and we discuss the validity of
their approximate expressions in terms of the decay asymmetry. In scenarios in
which the initial heavy neutrino density vanishes, the inclusion of CP
asymmetries in scatterings can enforce a cancellation between the lepton
asymmetry generated at early times and the asymmetry produced at later times.
We argue that a sizeable amount of washout is crucial for spoiling this
cancellation, and we show that in the regimes in which the washouts are
particularly weak, the inclusion of CP violation in scatterings yields a
reduction in the final value of the lepton asymmetry. In the strong washout
regimes the inclusion of CP violation in scatterings still leads to a
significant enhancement of the lepton asymmetry at high temperatures; however,
due to the independence from the early conditions that is characteristic of
these regimes, the final value of the lepton asymmetry remains approximately
unchanged.


title:
Dependence of Resonant Absorption Linewidth on Atomic Vapour Column
  Thickness for D1 Line of Cs Atoms Confined in Nano-Cell

abstract:
  A new nano-cell with smoothly varying longitudinal thickness of the atomic
vapour layer L in the range of 350 - 5100 nm allowing to study the resonant
absorption of D1 and D2 lines of Cs atoms for thicknesses changing from L =
Lambda/2 to L = 6 Lambda with the step of Lambda/2 (Lambda = 852 nm or 894 nm
are the resonant laser wavelengths) and for different intensities is developed.
It is revealed that for low laser intensities there is narrowing of the
resonant absorption spectrum for the thicknesses L = (2n + 1)Lambda/2 (where n
is an integer) up to L = 7Lambda /2 and broadening of the spectrum for L = n
Lambda. For relatively high laser intensity (>1 mW/cm2), velocity selective
optical pumping/saturated resonances of a reduced absorption (with the
line-width close to the natural one), and centred on the hyperfine transitions
occur when L = n Lambda. The possible application of these resonance peaks is
given. The developed theoretical model describes well the experiment.


title: Expanding Space: the Root of all Evil?

abstract:
  While it remains the staple of virtually all cosmological teaching, the
concept of expanding space in explaining the increasing separation of galaxies
has recently come under fire as a dangerous idea whose application leads to the
development of confusion and the establishment of misconceptions. In this
paper, we develop a notion of expanding space that is completely valid as a
framework for the description of the evolution of the universe and whose
application allows an intuitive understanding of the influence of universal
expansion. We also demonstrate how arguments against the concept in general
have failed thus far, as they imbue expanding space with physical properties
not consistent with the expectations of general relativity.


title:
Strong and electroweak corrections to the production of Higgs+2jets via
  weak interactions at the LHC

abstract:
  Radiative corrections of strong and electroweak interactions are presented at
next-to-leading order for the production of a Higgs boson plus two hard jets
via weak interactions at the LHC. The calculation includes all weak-boson
fusion and quark-antiquark annihilation diagrams as well as the corresponding
interferences. The electroweak corrections, which are discussed here for the
first time, reduce the cross sections by 5%, and thus are of the same order of
magnitude as the QCD corrections. As argued in previous papers, where s-channel
diagrams and interferences were neglected, the QCD corrections connected to
interference effects are small.


title:
Why are accreting T Tauri stars less luminous in X-rays than
  non-accretors?

abstract:
  Accreting T Tauri stars are observed to be less luminous in X-rays than
non-accretors, an effect that has been detected in various star forming
regions. To explain this we have combined, for the first time, a radiative
transfer code with an accretion model that considers magnetic fields
extrapolated from surface magnetograms obtained from Zeeman-Doppler imaging.
Such fields consist of compact magnetic regions close to the stellar surface,
with extended field lines interacting with the disk. We study the propagation
of coronal X-rays through the magnetosphere and demonstrate that they are
strongly absorbed by the dense gas in accretion columns.


title: Pair condensation of bosonic atoms induced by optical lattices

abstract:
  We design a model of correlated hopping for bosonic atoms in optical
lattices. Such model exhibits three kinds of phases, comprehending a Mott
insulator, a charge density wave and a pair quasi-condensate. The
implementation of the model relies on two-state atoms embedded in
state-dependent lattices and having spin-dependent interactions. Contrary to
other models of pairing, our design is not based on perturbative effects and
should be observable in current experiments.


title:
Ab-initio calculation of phonon dispersion curves: accelerating q point
  convergence

abstract:
  We present a scheme for the improved description of the long-range
interatomic force constants in a more accurate way than the procedure which is
commonly used within plane-wave based density-functional perturbation-theory
calculations. Our scheme is based on the inclusion of a q point grid which is
denser in a restricted area around the center of the Brillouin Zone than in the
remaining parts, even though the method is not limited to an area around Gamma.
We have tested the validity of our procedure in the case of high-pressure
phases of bulk silicon considering the bct and sh structure.

categories: cond-mat.mtrl-sci cond-mat.dis-nn cond-mat.mes-hall cond-mat.other cond-mat.soft cond-mat.stat-mech


title:
Specialization of strategies and herding behavior of trading firms in a
  financial market

abstract:
  The understanding of complex social or economic systems is an important
scientific challenge. Here we present a comprehensive study of the Spanish
Stock Exchange showing that most financial firms trading in that market are
characterized by a resulting strategy and can be classified in groups of firms
with different specialization. Few large firms overally act as trending firms
whereas many heterogeneous firm act as reversing firms. The herding properties
of these two groups are markedly different and consistently observed over a
four-year period of trading.


title:
BRST approach to Lagrangian formulation for mixed-symmetry fermionic
  higher-spin fields

abstract:
  We construct a Lagrangian description of irreducible half-integer higher-spin
representations of the Poincare group with the corresponding Young tableaux
having two rows, on a basis of the BRST approach. Starting with a description
of fermionic higher-spin fields in a flat space of any dimension in terms of an
auxiliary Fock space, we realize a conversion of the initial operator
constraint system (constructed with respect to the relations extracting
irreducible Poincare-group representations) into a first-class constraint
system. For this purpose, we find auxiliary representations of the constraint
subsuperalgebra containing the subsystem of second-class constraints in terms
of Verma modules. We propose a universal procedure of constructing
gauge-invariant Lagrangians with reducible gauge symmetries describing the
dynamics of both massless and massive fermionic fields of any spin. No
off-shell constraints for the fields and gauge parameters are used from the
very beginning. It is shown that the space of BRST cohomologies with a
vanishing ghost number is determined only by the constraints corresponding to
an irreducible Poincare-group representation. To illustrate the general
construction, we obtain a Lagrangian description of fermionic fields with
generalized spin (3/2,1/2) and (3/2,3/2) on a flat background containing the
complete set of auxiliary fields and gauge symmetries.


title: Planar Homological Mirror Symmetry

abstract:
  In this article, we formulate a planar limited version of the B-side in
homological mirror symmetry that formularizes Chern-Simons-type topological
open string field theory using homotopy associative algebra ($A_{\infty}$
algebra). This formulation is based on the works by Dijkgraaf and Vafa. We show
that our formularization includes gravity/gauge theory correspondence which
originates in the AdS/CFT duality of Dijkgraaf-Vafa theory.


title: From boundary to bulk in logarithmic CFT

abstract:
  The analogue of the charge-conjugation modular invariant for rational
logarithmic conformal field theories is constructed. This is done by
reconstructing the bulk spectrum from a simple boundary condition (the analogue
of the Cardy `identity brane'). We apply the general method to the c_1,p
triplet models and reproduce the previously known bulk theory for p=2 at c=-2.
For general p we verify that the resulting partition functions are modular
invariant. We also construct the complete set of 2p boundary states, and
confirm that the identity brane from which we started indeed exists. As a
by-product we obtain a logarithmic version of the Verlinde formula for the
c_1,p triplet models.


title: A remark on fractional integrals on modulation spaces

abstract:
  In this paper, we give the necessary and sufficient conditions for the
boundedness of fractional integral operators on the modulation spaces.


title:
The York Map and the Role of Non-Inertial Frames in the Geometrical View
  of the Gravitational Field

abstract:
  The role of non-inertial frames in a class of models of general relativity is
clarified by means of Dirac's theory of constraints. The identification of a
York canonical basis allows to give the interpretation of the gauge variables
as generalized inertial effects and to identify the Dirac observables of the
gravitational field with generalized tidal effects. York time is the gauge
variable controlling the clock synchronization convention. Differently from
special relativity, the instantaneous 3-spaces are dynamically determined.


title:
On the $L^2$-boundedness of pseudo-differential operators and their
  commutators with symbols in $\alpha$-modulation spaces

abstract:
  In this paper, we consider the $L^2$-boundedness of pseudo-differential
operators with symbols in $\alpha$-modulation spaces.


title:
Measurement of the Strong Coupling alpha_s from the Four-Jet Rate in
  e+e- Annihilation using JADE data

abstract:
  Data from e+e- annihilation into hadrons collected by the JADE experiment at
centre-of-mass energies between 14 GeV and 44 GeV are used to study the
four-jet event production rate as a function of the Durham jet algorithm's
resolution parameter ycut. The four-jet rate is compared to QCD next-to-leading
order calculations including resummation of large logarithms in the
next-to-leading logarithmic approximation. The strong coupling measured from
the four-jet rate is
as(MZ)=0.1159+-0.0004(stat)+-0.0012(expt)+-0.0024(had)+-0.0007(theo) in
agreement with the world average.


title:
Supernovae in the Subaru Deep Field: An Initial Sample, and Type Ia
  Rate, out to Redshift 1.6

abstract:
  Large samples of high-redshift supernovae (SNe) are potentially powerful
probes of cosmic star formation, metal enrichment, and SN physics. We present
initial results from a new deep SN survey, based on re-imaging in the R, i', z'
bands, of the 0.25 deg2 Subaru Deep Field (SDF), with the 8.2-m Subaru
telescope and Suprime-Cam. In a single new epoch consisting of two nights of
observations, we have discovered 33 candidate SNe, down to a z'-band magnitude
of 26.3 (AB). We have measured the photometric redshifts of the SN host
galaxies, obtained Keck spectroscopic redshifts for 17 of the host galaxies,
and classified the SNe using the Bayesian photometric algorithm of Poznanski et
al. (2007) that relies on template matching. After correcting for biases in the
classification, 55% of our sample consists of Type Ia supernovae and 45% of
core-collapse SNe. The redshift distribution of the SNe Ia reaches z ~ 1.6,
with a median of z ~ 1.2. The core-collapse SNe reach z ~ 1.0, with a median of
z ~ 0.5. Our SN sample is comparable to the Hubble Space Telescope/GOODS sample
both in size and redshift range. The redshift distributions of the SNe in the
SDF and in GOODS are consistent, but there is a trend (which requires
confirmation using a larger sample) for more high-z SNe Ia in the SDF. This
trend is also apparent when comparing the SN Ia rates we derive to those based
on GOODS data. Our results suggest a fairly constant rate at high redshift that
could be tracking the star-formation rate. Additional epochs on this field,
already being obtained, will enlarge our SN sample to the hundreds, and
determine whether or not there is a decline in the SN Ia rate at z >~ 1.


title:
Identification of candidate regulatory sequences in mammalian 3' UTRs by
  statistical analysis of oligonucleotide distributions

abstract:
  3' untranslated regions (3' UTRs) contain binding sites for many regulatory
elements, and in particular for microRNAs (miRNAs). The importance of
miRNA-mediated post-transcriptional regulation has become increasingly clear in
the last few years.
  We propose two complementary approaches to the statistical analysis of
oligonucleotide frequencies in mammalian 3' UTRs aimed at the identification of
candidate binding sites for regulatory elements. The first method is based on
the identification of sets of genes characterized by evolutionarily conserved
overrepresentation of an oligonucleotide. The second method is based on the
identification of oligonucleotides showing statistically significant strand
asymmetry in their distribution in 3' UTRs.
  Both methods are able to identify many previously known binding sites located
in 3'UTRs, and in particular seed regions of known miRNAs. Many new candidates
are proposed for experimental verification.


title: Warm molecular hydrogen in the Spitzer SINGS galaxy sample

abstract:
  (simplified) Results on the properties of warm H2 in 57 normal galaxies are
derived from H2 rotational transitions, obtained as part of SINGS. This study
extends previous extragalactic surveys of H2, the most abundant constituent of
the molecular ISM, to more common systems (L_FIR = e7 to 6e10 L_sun) of all
morphological and nuclear types. The S(1) transition is securely detected in
the nuclear regions of 86% of SINGS galaxies with stellar masses above 10^9.5
M_sun. The derived column densities of warm H2 (T > ~100 K), even though
averaged over kiloparsec-scale areas, are commensurate with those of resolved
PDRs; the median of the sample is 3e20 cm-2. They amount to between 1% and >30%
of the total H2. The power emitted in the sum of the S(0) to S(2) transitions
is on average 30% of the [SiII] line power, and ~4e-4 of the total infrared
power (TIR) within the same area for star-forming galaxies, which is consistent
with excitation in PDRs. The fact that H2 emission scales tightly with PAH
emission, even though the average radiation field intensity varies by a factor
ten, can also be understood if both tracers originate predominantly in PDRs,
either dense or diffuse. A large fraction of the 25 LINER/Sy targets, however,
strongly depart from the rest of the sample, in having warmer H2 in the excited
states, and an excess of H2 emission with respect to PAHs, TIR and [SiII]. We
propose a threshold in H2 to PAH power ratios, allowing the identification of
low-luminosity AGNs by an excess H2 excitation. A dominant contribution from
shock heating is favored in these objects. Finally, we detect, in nearly half
the star-forming targets, non-equilibrium ortho to para ratios, consistent with
FUV pumping combined with incomplete ortho-para thermalization by collisions,
or possibly non-equilibrium PDR fronts advancing into cold gas.


title: Finite volume QCD at fixed topological charge

abstract:
  In finite volume the partition function of QCD with a given $\theta$ is a sum
of different topological sectors with a weight primarily determined by the
topological susceptibility. If a physical observable is evaluated only in a
fixed topological sector, the result deviates from the true expectation value
by an amount proportional to the inverse space-time volume 1/V. Using the
saddle point expansion, we derive formulas to express the correction due to the
fixed topological charge in terms of a 1/V expansion. Applying this formula, we
propose a class of methods to determine the topological susceptibility in QCD
from various correlation functions calculated in a fixed topological sector.


title: Robust Audio Watermarking Against the D/A and A/D conversions

abstract:
  Audio watermarking has played an important role in multimedia security. In
many applications using audio watermarking, D/A and A/D conversions (denoted by
DA/AD in this paper) are often involved. In previous works, however, the
robustness issue of audio watermarking against the DA/AD conversions has not
drawn sufficient attention yet. In our extensive investigation, it has been
found that the degradation of a watermarked audio signal caused by the DA/AD
conversions manifests itself mainly in terms of wave magnitude distortion and
linear temporal scaling, making the watermark extraction failed. Accordingly, a
DWT-based audio watermarking algorithm robust against the DA/AD conversions is
proposed in this paper. To resist the magnitude distortion, the relative energy
relationships among different groups of the DWT coefficients in the
low-frequency sub-band are utilized in watermark embedding by adaptively
controlling the embedding strength. Furthermore, the resynchronization is
designed to cope with the linear temporal scaling. The time-frequency
localization characteristics of DWT are exploited to save the computational
load in the resynchronization. Consequently, the proposed audio watermarking
algorithm is robust against the DA/AD conversions, other common audio
processing manipulations, and the attacks in StirMark Benchmark for Audio,
which has been verified by experiments.


title:
Exchange effects on electron scattering through a quantum dot embedded
  in a two-dimensional semiconductor structure

abstract:
  We have developed a theoretical method to study scattering processes of an
incident electron through an N-electron quantum dot (QD) embedded in a
two-dimensional (2D) semiconductor. The generalized Lippmann-Schwinger
equations including the electron-electron exchange interaction in this system
are solved for the continuum electron by using the method of continued
fractions (MCF) combined with 2D partial-wave expansion technique. The method
is applied to a one-electron QD case. Cross-sections are obtained for both the
singlet and triplet couplings between the incident electron and the QD electron
during the scattering. The total elastic cross-sections as well as the
spin-flip scattering cross-sections resulting from the exchange potential are
presented. Furthermore, inelastic scattering processes are also studied using a
multichannel formalism of the MCF.


title:
Low-lying ud anti-s anti-s configurations in a non-relativistic
  constituent quark model

abstract:
  The energies of the low-lying isoscalar and isovector ud anti-s anti-s
configurations with spin-parity J^P=0^+, 1^+, and 2^+ are calculated in a
non-relativistic constituent quark model by use of the variational method. The
contributions of various parts of the quark-quark interacting potentials
including the s-channel interaction are investigated, and the effect of
different forms of confinement potential is examined. The model parameters are
determined by the same method as in our previous work, and they still can
satisfactorily describe the nucleon-nucleon scattering phase shifts and the
hyperon-nucleon cross sections. The parameters of the s-channel interaction are
fixed by the masses of K and K^* mesons, for which the size parameter is taken
to be two possible values. When it is chosen as the same as baryons', the
numerical results show that the masses of all the ud anti-s anti-s
configurations are higher than the corresponding meson-meson thresholds. But
when the size parameter for the K and K^* mesons is adjusted to be smaller than
that for the baryons, the ud anti-s anti-s configuration with I=0 and J^P=1^+
is found to lie lower than the K^*K^* threshold, furthermore, this state has a
very small KK^* component and the interaction matrix elements between this
state and KK^* is comparatively small, thus its coupling to the KK^* channel
will consequently be weak and it might be regarded as a possible tetraquark
candidate.


title: Singular Hecke algebras, Markov traces, and HOMFLY-type invariants

abstract:
  We define the singular Hecke algebra ${\mathcal H} (SB_n)$ as the quotient of
the singular braid monoid algebra ${\mathbb C} (q) [SB_n]$ by the Hecke
relations $\sigma_k^2 = (q-1) \sigma_k +q$, $1 \le k\le n-1$, and define the
Markov traces on the sequence $\{{\mathcal H}(SB_n)\}_{n=1}^{+\infty}$ in the
same way as for the Markov traces on the tower of (non-singular) Hecke algebras
of the symmetric groups. We prove that the Markov traces are in one-to-one
correspondance with the invariants that satisfies some skein relation, and
compute an explicit classification of the Markov traces. Thanks to this
classification, we define some universal HOMFLY-type invariant which has the
property that it distinguishes all the pairs of singular links that can be
distinguished by an invariant which satisfies the required skein relation.


title: J.S. Bell's Concept of Local Causality

abstract:
  John Stewart Bell's famous 1964 theorem is widely regarded as one of the most
important developments in the foundations of physics. It has even been
described as "the most profound discovery of science." Yet even as we approach
the 50th anniversary of Bell's discovery, its meaning and implications remain
controversial. Many textbooks and commentators report that Bell's theorem
refutes the possibility (suggested especially by Einstein, Podolsky, and Rosen
in 1935) of supplementing ordinary quantum theory with additional ("hidden")
variables that might restore determinism and/or some notion of an
observer-independent reality. On this view, Bell's theorem supports the
orthodox Copenhagen interpretation. Bell's own view of his theorem, however,
was quite different. He instead took the theorem as establishing an "essential
conflict" between the now well-tested empirical predictions of quantum theory
and relativistic \emph{local causality}. The goal of the present paper is, in
general, to make Bell's own views more widely known and, in particular, to
explain in detail Bell's little-known mathematical formulation of the concept
of relativistic local causality on which his theorem rests. We thus collect and
organize many of Bell's crucial statements on these topics, which are scattered
throughout his writings, into a self-contained, pedagogical discussion
including elaborations of the concepts "beable", "completeness", and
"causality" which figure in the formulation. We also show how local causality
(as formulated by Bell) can be used to derive an empirically testable Bell-type
inequality, and how it can be used to recapitulate the EPR argument.


title:
The maximum output p-norm of quantum channels is not multiplicative for
  any p>2

abstract:
  We prove the claim made in the title by showing that approximately
randomising maps of large dimension are counterexamples to the multiplicativity
conjecture.


title: Dynamical control of matter-wave tunneling in periodic potentials

abstract:
  We report on measurements of dynamical suppression of inter-well tunneling of
a Bose-Einstein condensate (BEC) in a strongly driven optical lattice. The
strong driving is a sinusoidal shaking of the lattice corresponding to a
time-varying linear potential, and the tunneling is measured by letting the BEC
freely expand in the lattice. The measured tunneling rate is reduced and, for
certain values of the shaking parameter, completely suppressed. Our results are
in excellent agreement with theoretical predictions. Furthermore, we have
verified that in general the strong shaking does not destroy the phase
coherence of the BEC, opening up the possibility of realizing quantum phase
transitions by using the shaking strength as the control parameter.


title:
Search for Direc Magnetic Monopoles in e+e- Collisions with the OPAL
  Detector at LEP2

abstract:
  This letter describes a direct search for pair produced magnetic monopoles in
e+e- collisions. The analysis is based on 62.7 pb^-1 of data collected with the
OPAL detector at an average centre-of-mass energy of sqrt(s)= 206.3GeV. The
monopole signal was assumed to be characterized by two back-to-back particles
with an anomalously high ionization energy loss de/dx in the tracking chambers.
No evidence for production of monopoles was observed. Upper limits were
obtained on the magnetic monopole pair-production cross-section (sigma) in the
mass range 45 GeV/c^2<m_M<102 GeV/c^2. The average limit is sigma < 0.05 pb and
is essentially independent of the magnetic monopole mass. The cross-section
limit is derived at the 95% confidence level and is valid for spin-1/2 magnetic
monopoles.


title: Casimir-Polder intermolecular forces in minimal length theories

abstract:
  Generalized uncertainty relations are known to provide a minimal length
$\hbar\sqrt{\beta}$. The effect of such minimal length in the Casimir-Polder
interactions between neutral atoms (molecules) is studied. The first order
correction term in the minimal uncertainty parameter is derived and found to
describe an attractive potential scaling as $r^{-9}$ as opposed to the well
known $r^{-7}$ long range retarded potential.


title:
On the onset of runaway stellar collisions in dense star clusters I.
  Dynamics of the first collision

abstract:
  We study the circumstances under which first collisions occur in young and
dense star clusters. The initial conditions for our direct $N$-body simulations
are chosen such that the clusters experience core collapse within a few million
years, before the most massive stars have left the main-sequence. It turns out
that the first collision is typically driven by the most massive stars in the
cluster. Upon arrival in the cluster core, by dynamical friction, massive stars
tend to form binaries. The enhanced cross section of the binary compared to a
single star causes other stars to engage the binary. A collision between one of
the binary components and the incoming third star is then mediated by the
encounters between the binary and other cluster members. Due to the geometry of
the binary-single star engagement the relative velocity at the moment of impact
is substantially different than in a two-body encounter. This may have profound
consequences for the further evolution of the collision product.


title:
Stellar Population Gradients in Bulges along the Hubble Sequence: I. The
  Data

abstract:
  This is the first paper presenting our long-term project aimed at studying
the nature of bulges through the analysis of their stellar population
gradients. We present deep spectroscopic observations along the minor axis and
the data reduction for a sample of 32 bulges of edge-on spiral galaxies. We
explain in detail our procedures to measure their dynamical parameters
(rotation curves and velocity dispersion profiles) and line-strength indices,
including the conversion to the Lick/IDS system. Tables giving the values of
the dynamical parameters and line-strength indices at each galactocentric
radius are presented (in electronic form) for each galaxy of the sample. The
derived line-strength gradients from this dataset will be analyzed in a
forthcoming paper to set constraints on the different scenarios for the
formation of the bulges.


title:
Disk-Evaporation Fed Corona: Structure and Evaporation Feature with
  Magnetic Field

abstract:
  The disk-corona evaporation model naturally interprets many observational
phenomena in black hole X-ray binaries, such as the truncation of an accretion
disk and the spectral state transitions. On the other hand, magnetic field is
known to play an important role in transporting angular momentum and producing
viscosity in accretion flows. In this work, we explicitly take the magnetic
field in the accretion disk corona into account and numerically calculate the
coronal structure on the basis of our two-temperature evaporation code. We show
that the magnetic field influences the coronal structure by its contribution to
the pressure, energy and radiative cooling in the corona and by decreasing the
vertical heat conduction. We found that the maximal evaporation rate keeps more
or less constant ($\sim 0.03$ Eddington rate) while the strength of magnetic
fields changes, but that the radius corresponding to the maximal evaporation
rate decreases with increasing magnetic field. This predicts that the spectral
state transition always occurs at a few percent of Eddington accretion rate,
while the inner edge of thin disk can be at $\sim 100 R_{\rm S} $ or even less
in the hard state before the transition to the soft state. These results
alleviate the problem that previous evaporation models predict too large a
truncation radius, and are in better agreement with the observational results
of several black hole X-ray binaries, though discrepancies remain.


title:
On conformal Killing-Yano tensors for Plebanski-Demianski family of
  solutions

abstract:
  We present the explicit expressions for the conformal Killing-Yano tensors
for the Plebanski-Demianski family of type D solutions in four dimensions. Some
physically important special cases are discussed in more detail. In particular,
it is demonstrated how the conformal Killing-Yano tensor becomes the
Killing-Yano tensor for the solutions without acceleration. A possible
generalization into higher dimensions is studied. Whereas the transition from
the nonaccelerating to accelerating solutions in four dimensions is achieved by
the conformal rescaling of the metric, we show that such a procedure is not
sufficiently general in higher dimensions - only the maximally symmetric
spacetimes in 'accelerated' coordinates are obtained.


title: On gas drag in a circular binary system

abstract:
  We investigate both analytically and numerically the motion of massless
particles orbiting primary star in a close circular binary system with
particular focus on the gas drag effects. These are the first calculations with
particles ranging in size from 1m to 10km, which account for the presence of a
tidally perturbed gaseous disk. We have found numerically that the radial mass
transport by the tidal waves plays a crucial role in the orbital evolution of
particles. Numerical results are confirmed analytical calculations that do not
assume anything about origin of the radial flow in the disk. We demonstrate
that the migration rate of a particle in a disk out of radial equilibrium is
enhanced due to the enhanced mass flux of gas colliding with the particle and
the migration is always directed inward regardless of the sign of the radial
gas velocity. Within the framework of the perturbation theory we derive
general, formulae for short-term variations of the particle semi-major axis,
eccentricity and inclination in such disk. The formulae account for departures
from axial symmetry by introducing effective components of the gas velocity.
They agree with numerical results within several percent. We have also found in
numerical simulations that the tidal waves introduce coherence in periastron
longitude and eccentricity for particles on neighbouring orbits. The degree of
the coherence depends on the particle size and on the distance from the primary
star, being most prominent for particles with 10m radius. The results are
important mainly in the context of planetesimal formation and, to a lesser
degree, during the early planetesimal accretion stage.


title: Interference pattern of a long diffusive Josephson junction

abstract:
  We calculate the modulation by a magnetic field of the critical current of a
long disordered Josephson junction in the diffusive limit, i.e. when the
dimensions of the junction are larger that the elastic mean free path, and when
the length $L$ is much larger than the width $w$. Due to the averaging of the
gauge invariant phase factor over diffusive trajectories, the well-known
oscillations of the Fraunhofer pattern are smoothed out and replaced by an
exponential decay at large field. The predicted pattern is universal, i.e., it
is independent of the disorder strength. We point out an interesting relation
with the physics of speckle correlations in optics of turbid media.


title:
Solution of non-singlet DGLAP evolution equation in leading order and
  next-to-leading order at small-x by method of characteristics

abstract:
  The non-singlet structure functions have been obtained by solving
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations in
leading order (LO) and next-to-leading order (NLO) at the small-x limit. Here a
Taylor series expansion has been used and then the method of characteristics
has been applied to solve the evolution equations. Results are comopared with
the Fermilab experiment E665 data and New Muon Collaboration (NMC) data.


title: Detuned Twin-Signal-Recycling for ultra-high precision interferometers

abstract:
  We propose a new interferometer technique for high precision phase
measurements such as those in gravitational wave detection. The technique
utilizes a pair of optically coupled resonators that provides identical
resonance conditions for the upper as well the lower phase modulation signal
sidebands. This symmetry significantly reduces the noise spectral density in a
wide frequency band compared with single sideband recycling topologies of
current and planned gravitational wave detectors. Furthermore the application
of squeezed states of light becomes less demanding.


title:
A computation of Poisson kernels for some standard weighted biharmonic
  operators in the unit disc

abstract:
  We compute Poisson kernels for integer weight parameter standard weighted
biharmonic operators in the unit disc with Dirichlet boundary conditions. The
computations performed extend the supply of explicit examples of such kernels
and suggest similar formulas for these Poisson kernels to hold true in more
generality. Computations have been carried out using the open source computer
algebra package Maxima.


title: Surface Encapsulation for Low-Loss Silicon Photonics

abstract:
  Encapsulation layers are explored for passivating the surfaces of silicon to
reduce optical absorption in the 1500-nm wavelength band. Surface-sensitive
test structures consisting of microdisk resonators are fabricated for this
purpose. Based on previous work in silicon photovoltaics, coatings of SiNx and
SiO2 are applied under varying deposition and annealing conditions. A short dry
thermal oxidation followed by a long high-temperature N2 anneal is found to be
most effective at long-term encapsulation and reduction of interface
absorption. Minimization of the optical loss is attributed to simultaneous
reduction in sub-bandgap silicon surface states and hydrogen in the capping
material.


title:
Relationship between non-exponentiality of relaxation and relaxation
  time at the glass transition

abstract:
  By analyzing the experimental data for various glass-forming liquids and
polymers, we find that non-exponentiality $\beta$ and the relaxation time
$\tau$ are uniquely related: $\log(\tau)$ is an approximately linear function
of $1/\beta$, followed by a crossover to a higher linear slope. We rationalize
the observed relationship using a recently developed approach, in which the
problem of the glass transition is discussed as the elasticity problem.


title:
Efficient identification of exoplanetary transit candidates from
  SuperWASP light curves

abstract:
  Transiting extrasolar planets constitute only a small fraction of the range
of stellar systems found to display periodic, shallow dimmings in wide-field
surveys employing small-aperture camera arrays. Here we present an efficient
selection strategy for follow-up observations, derived from analysis of the
light curves of a sample of 67 SuperWASP targets that passed the selection
tests we used in earlier papers, but which have subsequently been identified
either as planet hosts or as astrophysical false positives. We determine the
system parameters using Markov-chain Monte Carlo analysis of the SuperWASP
light curves. We use a constrained optimisation of chi-squared combined with a
Bayesian prior based on the main-sequence mass and radius expected from the
2MASS J-H colour. The Bayesian nature of the analysis allows us to quantify
both the departure of the host star from the main-sequence mass-radius relation
and the probability that the companion radius is less than 1.5 Jupiter radii.
When augmented by direct light curve analyses that detect binaries with unequal
primary and secondary eclipses, and objects with aperture blends that are
resolved by SuperWASP, we find that only 13 of the original 67 stars, including
the three known planets in the sample, would qualify for follow-up. This
suggests that planet discovery "hit rates" better than one-in-five should be
achievable. In addition, the stellar binaries that qualify are likely to have
astrophysically interesting stellar or sub-stellar secondaries.


title: Random matrices beyond the Cartan classification

abstract:
  It is known that hermitean random matrix ensembles can be identified with
symmetric coset spaces of Lie groups, or else with tangent spaces of the same.
This results in a classification of random matrix ensembles as well as
applications in practical calculations of physical observables. In this paper
we show that a large number of non-hermitean random matrix ensembles defined by
physically motivated symmetries - chiral symmetry, time reversal invariance,
space rotation invariance, particle-hole symmetry, or different reality
conditions - can likewise be identified with symmetric spaces. We give explicit
representations of the random matrix ensembles identified with lateral algebra
subspaces, and of the corresponding symmetric subalgebras spanning the group of
invariance. Among the ensembles listed we identify as special cases all the
hermitean ensembles identified with Cartan classes of symmetric spaces and the
three Ginibre ensembles with complex eigenvalues.

categories: math-ph cond-mat.mes-hall hep-ph hep-th math.MP


title: Radiative and semileptonic decays in Chiral Perturbation Theory

abstract:
  I give a short overview of what has been done in radiative and semileptonic
Kaon decays in Chiral Perturbation Theory. This includes for semileptonic
decays the work which has been done to order $p^6$ including preliminary
results of isospin breaking to that order in $K_{\ell3}$. For the radiative
decays I mainly present some results from recent work concerning
$K_{\ell3\gamma}$.


title: Entropy of Extremal Black Holes in Two Dimension

abstract:
  In this paper we apply the entropy function formalism to the two-dimensional
black hole which come from the compactification of the heterotic string theory
with the dilaton coupling function. We find the Bekenstein-Hawking entropy from
the value of the entropy function at its saddle point. Also we consider higher
derivative terms. After that we apply the entropy function formalism to the
Jackiw-Teitelboim (JT) model where we consider the effect of string-loop to
this model.


title: The $k$-anonymity Problem is Hard

abstract:
  The problem of publishing personal data without giving up privacy is becoming
increasingly important. An interesting formalization recently proposed is the
k-anonymity. This approach requires that the rows in a table are clustered in
sets of size at least k and that all the rows in a cluster become the same
tuple, after the suppression of some records. The natural optimization problem,
where the goal is to minimize the number of suppressed entries, is known to be
NP-hard when the values are over a ternary alphabet, k = 3 and the rows length
is unbounded. In this paper we give a lower bound on the approximation factor
that any polynomial-time algorithm can achive on two restrictions of the
problem,namely (i) when the records values are over a binary alphabet and k =
3, and (ii) when the records have length at most 8 and k = 4, showing that
these restrictions of the problem are APX-hard.


title:
Dimerization process and elementary excitations in spin-Peierls chains
  coupled by frustrated interactions

abstract:
  We consider the ground state and the elementary excitations of an array of
spin-Peierls chains coupled by elastic and magnetic interactions. It is
expected that the effect of the magnetic interchain coupling will be to reduce
the dimerization amplitude and that of the elastic coupling will be to confine
the spin one-half solitons corresponding to each isolated chain. We show that
this is the case when these interactions are not frustrated. On the other hand,
in the frustrated case we show that the amplitude of dimerization in the ground
state is independent of the strength of the interchain magnetic interaction in
a broad range of values of this parameter. We also show that free solitons
could be the elementary excitations when only nearest neighbor interactions are
considered. The case of an elastic interchain coupling is analyzed on a general
energetic consideration. To study the effect of the magnetic interchain
interaction the problem is simplified to a two-leg ladder which is solved using
DMRG calculations. We show that the deconfinement mechanism is effective even
with a significantly strong antiferromagnetic interchain coupling.


title: Inverse bremsstrahlung contributions to Drell-Yan like processes

abstract:
  The contribution of the sub-process $\gamma q \to q' l_1\bar{l}_2$ in
hadron-hadron interactions is considered. It is a part of one-loop electroweak
radiative corrections for the Drell-Yan production of lepton pairs at hadron
colliders. It is shown that this contribution should be taken into account
aiming at the 1% accuracy of the Drell-Yan process theoretical description.
Both the neutral and charged current cases are evaluated. Numerical results are
presented for typical conditions of LHC experiments.


title: AdS/CFT for Four-Point Amplitudes involving Gravitino Exchange

abstract:
  In this paper we compute the tree-level four-point scattering amplitude of
two dilatini and two axion-dilaton fields in type IIB supergravity in AdS5 x
S5. A special feature of this process is that there is an "exotic" channel in
which there are no singleparticle poles. Another novelty is that this process
involves the exchange of a bulk gravitino. The amplitude is interpreted in
terms of N = 4 supersymmetric Yang-Mills theory at large 't Hooft coupling.
Properties of the Operator Product Expansion are used to analyze the various
contributions from single- and double-trace operators in the weak and strongly
coupled regimes, and to determine the anomalous dimensions of semi-short
operators. The analysis is particularly clear in the exotic channel, given the
absence of BPS states.


title: Random Normal Matrices and Polynomial Curves

abstract:
  We show that in the large matrix limit, the eigenvalues of the normal matrix
model for matrices with spectrum inside a compact domain with a special class
of potentials homogeneously fill the interior of a polynomial curve uniquely
defined by the area of its interior domain and its exterior harmonic moments
which are all given as parameters of the potential.
  Then we consider the orthogonal polynomials corresponding to this matrix
model and show that, under certain assumptions, the density of the zeros of the
highest relevant orthogonal polynomial in the large matrix limit is (up to some
constant factor) given by the discontinuity of the Schwarz function of this
polynomial curve.


title: Multinucleon transfer reactions in closed-shell nuclei

abstract:
  Multinucleon transfer reactions in 40Ca+96Zr and 90Zr+208Pb have been
measured at energies close to the Coulomb barrier in a high resolution
gamma-particle coincidence experiment. The large solid angle magnetic
spectrometer PRISMA coupled to the CLARA gamma-array has been employed.
Trajectory reconstruction has been applied for the complete identification of
transfer products. Mass and charge yields, total kinetic energy losses, gamma
transitions of the binary reaction partners, and comparison of data with
semiclassical calculations are reported. Specific transitions in 95Zr populated
in one particle transfer channels are discussed in terms of particle-phonon
couplings. The gamma decays from states in 42Ca in the excitation energy region
expected from pairing vibrations are also observed.


title: Complete isometries between subspaces of noncommutative Lp-spaces

abstract:
  We prove some noncommutative analogues of a theorem by Plotkin and Rudin
about isometries between subspaces of Lp-spaces. Let 0<p<\infty, p not an even
integer. The main result of this paper states that in the category of unital
subspaces of noncommutative probability Lp-spaces, under some boundedness
condition, the unital completely isometric maps come from *-isomorphisms of the
underlying von Neumann algebras.
  Some applications are given, including to non commutative H^p spaces.


title:
Template-based searches for gravitational waves: efficient lattice
  covering of flat parameter spaces

abstract:
  The construction of optimal template banks for matched-filtering searches is
an example of the sphere covering problem. For parameter spaces with
constant-coefficient metrics a (near-) optimal template bank is achieved by the
A_n* lattice, which is the best lattice-covering in dimensions n <= 5, and is
close to the best covering known for dimensions n <= 16. Generally this
provides a substantially more efficient covering than the simpler hyper-cubic
lattice. We present an algorithm for generating lattice template banks for
constant-coefficient metrics and we illustrate its implementation by generating
A_n* template banks in n=2,3,4 dimensions.


title: The Axion from Five-Dimensional Supergravity

abstract:
  We consider the axion arising from five-dimensional supergravity in the
presence of boundaries. We find the approximate bosonic effective action to
estimate the lower bound on the "Peccei-Quinn" energy scale with a flat bulk.
With a warped bulk, one can obtain a scale within the standard window; this
puts a bound on the required curvature scale relative to the proper separation
between boundaries. We comment on the scalar potential that may ruin the
strong-CP resolution, and the effective derivative coupling to matter in 5D
hypermultiplets.


title: Assisted Problem Solving and Decompositions of Finite Automata

abstract:
  A study of assisted problem solving formalized via decompositions of
deterministic finite automata is initiated. The landscape of new types of
decompositions of finite automata this study uncovered is presented. Languages
with various degrees of decomposability between undecomposable and perfectly
decomposable are shown to exist.


title: Wick ordering for coherent state quantization in 1+1 de Sitter space

abstract:
  We show that the coherent state quantization of massive particles in 1+1 de
Sitter space exhibits an ordering property: There exist some classical
observables $A$ and $A^*$ such that $O_{A^{*p}}O_{A^q}=O_{A^{*p} A^q}$ $p, q
\in \Z$, where $O_A$ is the quantum observable corresponding to the classical
observable $A$.


title:
An algebraic proof of the commutativity of the intersection with
  divisors

abstract:
  We present a purely algebraic proof of the commutativity of the operation
defined by intersection with divisors on the Chow group of a local Noetherian
domain.


title: Unstable Semiclassical Trajectories in Tunneling

abstract:
  Some tunneling phenomena are described, in the semiclassical approximation,
by unstable complex trajectories. We develop a systematic procedure to
stabilize the trajectories and to calculate the tunneling probability,
including both the suppression exponent and prefactor. We find that the
instability of tunneling solutions modifies the power-law dependence of the
prefactor on h as compared to the case of stable solutions.

categories: quant-ph cond-mat.stat-mech hep-th math-ph math.MP nlin.CD physics.chem-ph


title: Another generalization of Mason's ABC-theorem

abstract:
  We show a generalization of Mason's ABC-theorem, with the only conditions
that the greatest common divisor has been divided out and no proper subsum of
the (possibly multivariate) polynomial sum f_1 + f_2 + ... + f_n = 0 vanishes.
  As a result, we show that the generalized Fermat-Catalan equation for
polynomials: g_1^{d_1} + g_1^{d_2} + ... + g_n^{d_n} = 0 has no non-constant
solutions if the greatest common divisor of the terms equals one, no proper
subsum vanishes and the hyperbolic sum 1/d_1 + 1/d_2 + ... + 1/d_n is at most
1/(n-2). Furthermore, we show that the generalized Fermat-equation for
polynomials g_1^d + g_1^d + ... + g_n^d = 0 has no 'interesting' solutions if d
>= n(n-2).


title:
Spectrally resolved optical frequency comb from a self-referenced 5 GHz
  femtosecond laser

abstract:
  We report a mode-locked Ti:sapphire femtosecond laser with 5GHz repetition
rate. Spectral broadening of the 24 fs pulses in a microstructured fiber yields
an octave-spanning spectrum and permits self-referencing and active
stabilization of the emitted femtosecond laser frequency comb (FLFC). The
individual modes of the 5GHz FLFC are resolved with a high-resolution
spectrometer based on a virtually imaged phased array (VIPA) spectral
disperser. Isolation of single comb elements at a microwatt average power level
is demonstrated. The combination of the high-power, frequency-stabilized 5GHz
laser and the straightforward resolution of its many modes will benefit
applications in direct frequency comb spectroscopy. Additionally, such a
stabilized FLFC should serve as a useful tool for direct mode-by-mode Fourier
synthesis of arbitrary optical waveforms.


title:
Multiparticle correlations and momentum conservation in nucleus-nucleus
  collisions

abstract:
  Particle correlations are very actively studied in heavy-ion collisions at
ultra-relativistic energies. Here, an attempt is made at determining a proper
reference for such studies, by taking properly into account the multiparticle
correlations induced by the conservation of total momentum in the collisions.


title: Modular Abelian Variety of Odd Modular Degree

abstract:
  We will study modular Abelian varieties with odd congruence numbers, by
studying the cuspidal subgroup of $J_0(N)$. We show the conductor of such
Abelian varieties must be of a special type, for example if $N$ is odd then
$N=p^\alpha$ or $N=pq$ for some prime $p$ and $q$. We then focus our attention
to modular elliptic curves, and using result of Agashe, Ribet, and Stein, we
try to classify all elliptic curves of odd modular degree. Our studies prove
many cases of the Stein and Watkins's conjecture on elliptic curves with odd
modular degree.


title:
High Performance Direct Gravitational N-body Simulations on Graphics
  Processing Units -- II: An implementation in CUDA

abstract:
  We present the results of gravitational direct $N$-body simulations using the
Graphics Processing Unit (GPU) on a commercial NVIDIA GeForce 8800GTX designed
for gaming computers. The force evaluation of the $N$-body problem is
implemented in ``Compute Unified Device Architecture'' (CUDA) using the GPU to
speed-up the calculations. We tested the implementation on three different
$N$-body codes: two direct $N$-body integration codes, using the 4th order
predictor-corrector Hermite integrator with block time-steps, and one
Barnes-Hut treecode, which uses a 2nd order leapfrog integration scheme. The
integration of the equations of motions for all codes is performed on the host
CPU.
  We find that for $N > 512$ particles the GPU outperforms the GRAPE-6Af, if
some softening in the force calculation is accepted. Without softening and for
very small integration time steps the GRAPE still outperforms the GPU. We
conclude that modern GPUs offer an attractive alternative to GRAPE-6Af special
purpose hardware. Using the same time-step criterion, the total energy of the
$N$-body system was conserved better than to one in $10^6$ on the GPU, only
about an order of magnitude worse than obtained with GRAPE-6Af. For $N \apgt
10^5$ the 8800GTX outperforms the host CPU by a factor of about 100 and runs at
about the same speed as the GRAPE-6Af.


title:
Work and heat probability distribution of an optically driven Brownian
  particle: Theory and experiments

abstract:
  We analyze the equations governing the evolution of distributions of the work
and the heat exchanged with the environment by a manipulated stochastic system,
by means of a compact and general derivation. We obtain explicit solutions for
these equations for the case of a dragged Brownian particle in a harmonic
potential. We successfully compare the resulting predictions with the outcomes
of experiments, consisting in dragging a micron-sized colloidal particle
through water with a laser trap.


title:
Lagrangian Particle Statistics in Turbulent Flows from a Simple Vortex
  Model

abstract:
  The statistics of Lagrangian particles in turbulent flows is considered in
the framework of a simple vortex model. Here, the turbulent velocity field is
represented by a temporal sequence of Burgers vortices of different
circulation, strain, and orientation. Based on suitable assumptions about the
vortices' statistical properties, the statistics of the velocity increments is
derived. In particular, the origin and nature of small-scale intermittency in
this model is investigated both numerically and analytically.


title:
Kelvon-roton instability of vortex lines in dipolar Bose-Einstein
  condensates

abstract:
  The physics of vortex lines in dipolar condensates is studied. Due to the
nonlocality of the dipolar interaction, the 3D character of the vortex plays a
more important role in dipolar gases than in typical short-range interacting
ones. In particular, the dipolar interaction significantly affects the
stability of the transverse modes of the vortex line. Remarkably, in the
presence of a periodic potential along the vortex line, a roton minimum may
develop in the spectrum of transverse modes. We discuss the appropriate
conditions at which this roton minimum may eventually lead to an instability of
the straight vortex line, opening new scenarios for vortices in dipolar gases.


title: Dyson's non-intersecting Brownian motions with a few outliers

abstract:
  Consider n non-intersecting particles on the real line (Dyson Brownian
motions), all starting from the origin at time=0, and forced to return to x=0
at time=1. For large n, the average mean density of particles has its support,
for each 0<t<1, within the interior of an ellipse. The Airy process is defined
as the motion of these non-intersecting Brownian motions for large n, but
viewed from an arbitrary point on the ellipse with an appropriate space-time
rescaling. Assume now a finite number r of these particles are forced to a
different target point. Does it affect the Brownian fluctuations along the
ellipse for large n? In this paper, we show that no new process appears as long
as one considers points on the ellipse, for which the t-coordinate is smaller
than the t-coordinate of the point of tangency of the tangent to the curve
passing through the target point. At this point of tangency the fluctuations
obey a new statistics: the Airy process with r outliers (in short: {\bf r-Airy
process}). The log of the transition probability of this new process is given
by the Fredholm determinant of a new kernel (extending the Airy kernel) and it
satisfies a non-linear PDE in x and the time.


title: On a possible interpretation of fusion in Stochastic Loewner Evolution

abstract:
  We suggest how to give a physical interpretation of Stochastic Loewner
Evolution traces approaching a marked point in the upper half plane. We show
that this may be related to the fusion of boundary with bulk fields in
Conformal Field Theory by taking a look at the probability of such an event.


title: Necessary and Sufficient Conditions for the Trumping Relation

abstract:
  Entanglement catalysis allows one to convert certain entangled states into
others by the temporary involvement of another entangled state (so-called
catalyst), where after the conversion the catalyst is returned to the same
state. For bipartite pure entangled states that can be transformed in this way
with unit probability, the respective Schmidt coefficients are said to satisfy
the trumping relation, a mathematical relation which is an extension of the
majorization relation. This article provides all necessary and sufficient
conditions for the trumping relation in terms of the Schmidt coefficients. The
coefficients should satisfy strict inequalities for the entropy of entanglement
and for power means excluding the special power 1.


title: Rubinstein distance on configurations spaces

abstract:
  By a method inspired of the Stein's method, we derive an upper-bound of the
Rubinstein distance between two absolutely continuous probability measures on
configurations space. As an application, we show that the best way to
approximate a Modulated Poisson Process (see below for the definition) by a
Poisson process is to equate their intensity.


title: $B \to K_1(1270) (\to \rho K) \ell^+ \ell^-$ in LEET

abstract:
  Flavour Changing Neutral Current decays of the $B$-meson are a very useful
tool for studying possible physics scenarios beyond the Standard Model (SM),
where of the many FCNC modes radiative, purely leptonic and semi-leptonic
decays of the $B$-meson are relatively clean tests. Within this context the
BELLE collaboration has searched for the $B \to K_1(1270) \gamma$ process and
provided an upper bound on this decay. In this work we have used this upper
bound in studying the angular coorelations for the related semi-leptonic decay
mode $B \to K_1(1270) (\to \rho K) \ell^+ \ell^-$, where we have used the form
factors that have already been estimated for the $B \to K_1(1270) \gamma$ mode.
Note that the additional form factors that are required were calculated using
the Large Energy Effective Theory (LEET).


title: Subrings which are closed with respect to taking the inverse

abstract:
  Let S be a subring of the ring R. We investigate the question of whether S
intersected by U(R) is equal to U(S) holds for the units. In many situations
our answer is positive. There is a special emphasis on the case when R is a
full matrix ring and S is a structural subring of R defined by a reflexive and
transitive relation.


title: Precision measurement of the $3d \to 2p$ x-ray energy in kaonic $^4$He

abstract:
  We have measured the Balmer-series x-rays of kaonic $^4$He atoms using novel
large-area silicon drift x-ray detectors in order to study the low-energy
$\bar{K}$-nucleus strong interaction. The energy of the $3d \to 2p$ transition
was determined to be 6467 $\pm$ 3 (stat) $\pm$ 2 (syst) eV. The resulting
strong-interaction energy-level shift is in agreement with theoretical
calculations, thus eliminating a long-standing discrepancy between theory and
experiment.


title: Optical spectroscopy of the low mass X-ray binary GX9+9

abstract:
  Phase-resolved medium resolution VLT spectroscopy of the low mass X-ray
binary GX9+9 has revealed narrow CIII emission lines that move in phase
relative to our new estimate of the ephemeris, and show a velocity amplitude of
230+/-35 km/s. We identify the origin of these lines as coming from the surface
of the donor star, thereby providing the first estimate of the mass function of
f(M_1)>=0.22M_sun. Rotational broadening estimates together with assumptions
for the mass donor give 0.07<q<0.35 and 182<K_2<406 km/s. Despite a low mass
ratio, there is no evidence for a superhump in our dataset. Doppler maps of
GX9+9 show the presence of a stream overflow, either in the form of material
flowing downward along the accretion disk rim or in a similar fashion as occurs
in high mass transfer rate cataclysmic variables known as the SW Sex stars.
Finally we note that the Bowen region in GX9+9 is dominated by CIII instead of
NIII emission as has been the case for most other X-ray binaries.


title: Large Negative Thermal Expansion in Pentacene due to Steric Hindrance

abstract:
  The uniaxial negative thermal expansion in pentacene crystals along $a$ is a
particularity in the series of the oligoacenes, and exeptionally large for a
crystalline solid. Full x-ray structure analysis from 120 K to 413 K reveals
that the dominant thermal motion is a libration of the rigid molecules about
their long axes, modifying the intermolecular angle which describes the
herringbone packing within the layers. This herringbone angle increases with
temperature (by 0.3 -- 0.6$^{\circ}$ per 100 K), and causes an anisotropic
rearrangement of the molecules within the layers, i.e. an expansion in the $b$
direction, and a distinct contraction along $a$. Additionally, a larger
herringbone angle improves the cofacial overlap between adjacent, parallel
molecules, and thus enhances the attractive van der Waals forces.


title:
Robust and efficient generator of almost maximal multipartite
  entanglement

abstract:
  Quantum chaotic maps can efficiently generate pseudo-random states carrying
almost maximal multipartite entanglement, as characterized by the probability
distribution of bipartite entanglement between all possible bipartitions of the
system. We show that such multipartite entanglement is robust, in the sense
that, when realistic noise is considered, distillable entanglement of
bipartitions remains almost maximal up to a noise strength that drops only
polynomially with the number of qubits.


title:
Instanton representation of Plebanski gravity: IX. Hamiltonian
  minisuperspace dynamics in undensitized momentum space variables

abstract:
  In this paper we illustrate the dynamics of the instanton representation in
the description of vacuum GR in minisuperspace for undensitized variables. We
uncover a new class of general solutions in both the degenerate and the
nondegenerate sectors of the theory. Additionally, the individual sectors are
preserved under Hamiltonian evolution. Finally, we present an algorithm for
constructing general solutions by expansion about the isotropic sector.


title:
Bose-Einstein condensates under a spatially-modulated transverse
  confinement

abstract:
  We derive an effective nonpolynomial Schrodinger equation (NPSE) for
self-repulsive or attractive BEC in the nearly-1D cigar-shaped trap, with the
transverse confining frequency periodically modulated along the axial
direction. Besides the usual linear cigar-shaped trap, where the periodic
modulation emulates the action of an optical lattice (OL), the model may be
also relevant to toroidal traps, where an ordinary OL cannot be created. For
either sign of the nonlinearity, extended and localized states are found, in
the numerical form (using both the effective NPSE and the full 3D
Gross-Pitaevskii equation) and by means of the variational approximation (VA).
The latter is applied to construct ground-state solitons and predict the
collapse threshold in the case of self-attraction. It is shown that numerical
solutions provided by the one-dimensional NPSE are always very close to full 3D
solutions, and the VA yields quite reasonable results too. The transition from
delocalized states to gap solitons, in the first finite bandgap of the linear
spectrum, is examined in detail, for the repulsive and attractive
nonlinearities alike.


title:
Optimal Strategies for Gaussian Jamming in Block-Fading Channels under
  Delay and Power Constraints

abstract:
  Without assuming any knowledge on source's codebook and its output signals,
we formulate a Gaussian jamming problem in block fading channels as a
two-player zero sum game. The outage probability is adopted as an objective
function, over which transmitter aims at minimization and jammer aims at
maximization by selecting their power control strategies. Optimal power control
strategies for each player are obtained under both short-term and long-term
power constraints. For the latter case, we first prove the non-existence of a
Nash equilibrium, and then provide a complete solution for both maxmin and
minimax problems. Numerical results demonstrate a sharp difference between the
outage probabilities of the minimax and maxmin solutions.


title: Strings and D-branes in a supersymmetric magnetic flux background

abstract:
  We investigate how the presence of RR magnetic $F_{p+2}$ fluxes affects the
energy of classical Dp branes, for specific string theory supersymmetric
backgrounds which are solutions to the leading order in $\alpha'$ including
back-reaction effects. The Dp brane dynamics is found to be similar to the well
known dynamics of particles and strings moving in magnetic fields. We find a
class of BPS solutions which generalize the BPS fundamental strings or BPS
branes with momentum and winding to the case of non-zero magnetic fields.
Remarkably, the interaction with the magnetic fields does not spoil the
supersymmetry of the solution, which turns out to be invariant under four
supersymmetry transformations. We find that magnetic fields can significantly
reduce the energy of some BPS strings and Dp branes, in particular, some
macroscopic Dp branes become light for sufficiently large magnetic fields.


title: Blocking: New examples and properties of products

abstract:
  We say that a pair of points x and y is secure if there exist a finite set of
blocking points such that any geodesic between x and y passes through one of
the blocking points. The main point of this paper is to exhibit new examples of
blocking phenomena both in the manifold and the billiard table setting. As an
approach to this, we study if the product of secure configurations (or
manifolds) is also secure.
  We introduce the concept of midpoint security that imposes that the geodesic
reaches a blocking point exactly at its midpoint. We prove that products of
midpoint secure configurations are midpoint secure. On the other hand, we give
an example of a compact C^1 surface that contains secure configurations that
are not midpoint secure. This surface provides the first example of an insecure
product of secure configurations, as well as billiard table examples.


title: Density of critical points for a Gaussian random function

abstract:
  Critical points of a scalar quantitiy are either extremal points or saddle
points. The character of the critical points is determined by the sign
distribution of the eigenvalues of the Hessian matrix. For a two-dimensional
homogeneous and isotropic random function topological arguments are sufficient
to show that all possible sign combinations are equidistributed or with other
words, the density of the saddle points and extrema agree. This argument breaks
down in three dimensions. All ratios of the densities of saddle points and
extrema larger than one are possible. For a homogeneous Gaussian random field
one finds no longer an equidistribution of signs, saddle points are slightly
more frequent.


title: Number fluctuations in cold quantum gases

abstract:
  In ultracold gases many experiments use atom imaging as a basic observable.
The resulting image is averaged over a number of realizations and mostly only
this average is used. Only recently the noise has been measured to extract
physical information. In the present paper we investigate the quantum noise
arising in these gases at zero temperature. We restrict ourselves to the
homogeneous situation and study the fluctuations in particle number found
within a given volume in the gas, and more specifically inside a sphere of
radius $R$. We show that zero-temperature fluctuations are not extensive and
the leading term scales with sphere radius $R$ as $R^2\ln R$ (or $\ln R$) in
three- (or one-) dimensional systems. We calculate systematically the next term
beyond this leading order. We consider first the generic case of a compressible
superfluid. Then we investigate the whole Bose-Einstein-condensation (BEC)-BCS
crossover crossover, and in particular the limiting cases of the weakly
interacting Bose gas and of the free Fermi gas.


title: Physical Network Coding in Two-Way Wireless Relay Channels

abstract:
  It has recently been recognized that the wireless networks represent a
fertile ground for devising communication modes based on network coding. A
particularly suitable application of the network coding arises for the two--way
relay channels, where two nodes communicate with each other assisted by using a
third, relay node. Such a scenario enables application of \emph{physical
network coding}, where the network coding is either done (a) jointly with the
channel coding or (b) through physical combining of the communication flows
over the multiple access channel. In this paper we first group the existing
schemes for physical network coding into two generic schemes, termed 3--step
and 2--step scheme, respectively. We investigate the conditions for
maximization of the two--way rate for each individual scheme: (1) the
Decode--and--Forward (DF) 3--step schemes (2) three different schemes with two
steps: Amplify--and--Forward (AF), JDF and Denoise--and--Forward (DNF). While
the DNF scheme has a potential to offer the best two--way rate, the most
interesting result of the paper is that, for some SNR configurations of the
source--relay links, JDF yields identical maximal two--way rate as the upper
bound on the rate for DNF.


title:
Gaussian potentials facilitate access to quantum Hall states in rotating
  Bose gases

abstract:
  Through exact numerical diagonalization for small numbers of atoms, we show
that it is possible to access quantum Hall states in harmonically confined Bose
gases at rotation frequencies well below the centrifugal limit by applying a
repulsive Gaussian potential at the trap center. The main idea is to reduce or
eliminate the effective trapping frequency in regions where the particle
density is appreciable. The critical rotation frequency required to obtain the
bosonic Laughlin state can be fixed at an experimentally accessible value by
choosing an applied Gaussian whose amplitude increases linearly with the number
of atoms while its width increases as the square root.


title:
High charge-carrier mobility and low trap density in a rubrene
  derivative

abstract:
  We have synthesized, crystallized and studied the structural and electric
transport properties of organic molecular crystals based on a rubrene
derivative with {\em t}-butyl sidegroups at the 5,11 positions. Two crystalline
modifications are observed: one (A) distinct from that of rubrene with larger
spacings between the naphtacene backbones, the other (B) with a in-plane
structure presumably very similar compared to rubrene. The electric transport
properties reflect the different structures: in the latter phase (B) the
in-plane hole mobility of 12 cm$^2$/Vs measured on single crystal FETs is just
as high as in rubrene crystals, while in the A phase no field-effect could be
measured. The high crystal quality, studied in detail for B, reflects itself in
the density of gap states: The deep-level trap density as low as $10^{15}$
cm$^{-3}$ eV$^{-1}$ has been measured, and an exponential band tail with a
characteristic energy of 22 meV is observed. The bulk mobility perpendicular to
the molecular planes is estimated to be of order of $10^{-3}$ -- $10^{-1}$
cm$^2$/Vs.


title: M-estimation of Boolean models for particle flow experiments

abstract:
  Probability models are proposed for passage time data collected in
experiments with a device designed to measure particle flow during aerial
application of fertilizer. Maximum likelihood estimation of flow intensity is
reviewed for the simple linear Boolean model, which arises with the assumption
that each particle requires the same known passage time. M-estimation is
developed for a generalization of the model in which passage times behave as a
random sample from a distribution with a known mean. The generalized model
improves fit in these experiments. An estimator of total particle flow is
constructed by conditioning on lengths of multi-particle clumps.


title: Blind Estimation of Multiple Carrier Frequency Offsets

abstract:
  Multiple carrier-frequency offsets (CFO) arise in a distributed antenna
system, where data are transmitted simultaneously from multiple antennas. In
such systems the received signal contains multiple CFOs due to mismatch between
the local oscillators of transmitters and receiver. This results in a
time-varying rotation of the data constellation, which needs to be compensated
for at the receiver before symbol recovery. This paper proposes a new approach
for blind CFO estimation and symbol recovery. The received base-band signal is
over-sampled, and its polyphase components are used to formulate a virtual
Multiple-Input Multiple-Output (MIMO) problem. By applying blind MIMO system
estimation techniques, the system response is estimated and used to
subsequently transform the multiple CFOs estimation problem into many
independent single CFO estimation problems. Furthermore, an initial estimate of
the CFO is obtained from the phase of the MIMO system response. The Cramer-Rao
Lower bound is also derived, and the large sample performance of the proposed
estimator is compared to the bound.


title: Far Infrared Prperties of M Dwarfs

abstract:
  We report the mid- and far-infrared properties of nearby M dwarfs.
Spitzer/MIPS measurements were obtained for a sample of 62 stars at 24 um, with
subsamples of 41 and 20 stars observed at 70 um and 160 um respectively. We
compare the results with current models of M star photospheres and look for
indications of circumstellar dust in the form of significant deviations of
K-[24 um] colors and 70 um / 24 um flux ratios from the average M star values.
At 24 um, all 62 of the targets were detected; 70 um detections were achieved
for 20 targets in the subsample observed; and no detections were seen in the
160 um subsample. No clear far-infrared excesses were detected in our sample.
The average far infrared excess relative to the photospheric emission of the M
stars is at least four times smaller than the similar average for a sample of
solar-type stars. However, this limit allows the average fractional infrared
luminosity in the M-star sample to be similar to that for more massive stars.
We have also set low limits for the maximum mass of dust possible around our
stars.


title: The game chromatic number of random graphs

abstract:
  Given a graph G and an integer k, two players take turns coloring the
vertices of G one by one using k colors so that neighboring vertices get
different colors. The first player wins iff at the end of the game all the
vertices of G are colored. The game chromatic number \chi_g(G) is the minimum k
for which the first player has a winning strategy. In this paper we analyze the
asymptotic behavior of this parameter for a random graph G_{n,p}. We show that
with high probability the game chromatic number of G_{n,p} is at least twice
its chromatic number but, up to a multiplicative constant, has the same order
of magnitude. We also study the game chromatic number of random bipartite
graphs.


title:
Lattice-Induced Double-Valley Degeneracy Lifting in Magnetic Field in
  Graphene

abstract:
  We show that the recently discovered double-valley splitting of the low-lying
Landau level(s) in the Quantum Hall Effect in graphene can be explained as
perturbative orbital interaction of intra- and inter-valley microscopic orbital
currents with a magnetic field. This effect is provided by the
translational-non-invariant terms corresponding to graphene's crystallographic
honeycomb symmetry but do not exist in the relativistic theory of massless
Dirac Fermions in Quantum Electrodynamics. We discuss recent data in view of
these results.


title: Star Formation Rate Determinations

abstract:
  I review determinations of star formation rates (SFR) from the ultraviolet to
the infrared, in the context of their use for galaxies and galaxy surveys. The
mid-infrared SFR indicators have garnered interest in recent years thanks to
the Spitzer capabilities and the opportunities offered by the upcoming Herschel
Space Telescope. I discuss what we have learned in the mid-infrared from
studies of local galaxies combining Spitzer with HST and other data.


title:
A Spitzer Study of the Mass Loss Histories of Three Bipolar
  Pre-Planetary Nebulae

abstract:
  We present the results of far-infrared imaging of extended regions around
three bipolar pre-planetary nebulae, AFGL 2688, OH 231.8+4.2, and IRAS
16342$-$3814, at 70 and 160 $\mu$m with the MIPS instrument on the Spitzer
Space Telescope. After a careful subtraction of the point spread function of
the central star from these images, we place constraints on the existence of
extended shells and thus on the mass outflow rates as a function of radial
distance from these stars. We find no apparent extended emission in AFGL 2688
and OH 231.8+4.2 beyond 100 arcseconds from the central source. In the case of
AFGL 2688, this result is inconsistent with a previous report of two extended
dust shells made on the basis of ISO observations. We derive an upper limit of
$2.1\times10^{-7}$ M$_\odot$ yr$^{-1}$ and $1.0\times10^{-7}$ M$_\odot$
yr$^{-1}$ for the dust mass loss rate of AFGL 2688 and OH 231.8, respectively,
at 200 arcseconds from each source. In contrast to these two sources, IRAS
16342$-$3814 does show extended emission at both wavelengths, which can be
interpreted as a very large dust shell with a radius of $\sim$ 400 arcseconds
and a thickness of $\sim$ 100 arcseconds, corresponding to 4 pc and 1 pc,
respectively, at a distance of 2 kpc. However, this enhanced emission may also
be galactic cirrus; better azimuthal coverage is necessary for confirmation of
a shell. If the extended emission is a shell, it can be modeled as enhanced
mass outflow at a dust mass outflow rate of $1.5\times10^{-6}$ M$_\odot$
yr$^{-1}$ superimposed on a steady outflow with a dust mass outflow rate of
$1.5\times10^{-7}$ M$_\odot$ yr$^{-1}$. It is likely that this shell has swept
up a substantial mass of interstellar gas during its expansion, so these
estimates are upper limits to the stellar mass loss rate.


title:
WMAP 3yr data with the CCA: anomalous emission and impact of component
  separation on the CMB power spectrum

abstract:
  The Correlated Component Analysis (CCA) allows us to estimate how the
different diffuse emissions mix in CMB experiments, exploiting also
complementary information from other surveys. It is especially useful to deal
with possible additional components. An application of CCA to WMAP maps
assuming that only the canonical Galactic emissions are present, highlights the
widespread presence of a spectrally flat "synchrotron" component, largely
uncorrelated with the synchrotron template, suggesting that an additional
foreground is indeed required. We have tested various spectral shapes for such
component, namely a power law as expected if it is flat synchrotron, and two
spectral shapes that may fit the spinning dust emission: a parabola in the logS
- log(frequency) plane, and a grey body. Quality tests applied to the
reconstructed CMB maps clearly disfavour two of the models. The CMB power
spectra, estimated from CMB maps reconstructed exploiting the three surviving
foreground models, are generally consistent with the WMAP ones, although at
least one of them gives a significantly higher quadrupole moment than found by
the WMAP team. Taking foreground modeling uncertainties into account, we find
that the mean quadrupole amplitude for the three "good" models is less than 1
sigma below the expectation from the standard LambdaCDM model. Also the other
reported deviations from model predictions are found not to be statistically
significant, except for the excess power at l~40. We confirm the evidence for a
marked North-South asymmetry in the large scale (l < 20) CMB anisotropies. We
also present a first, albeit preliminary, all-sky map of the "anomalous"
component.


title: Search for Extra Dimensions with Atlas and CMS Detectors at the LHC

abstract:
  A brief review of the discovery potential of the ATLAS and CMS experiments to
search for signals from extra dimensions in different luminosity scenarios is
given.


title:
Method to extract the primary cosmic ray spectrum from very high energy
  gamma-ray data and its application to SNR RX J1713.7-3946

abstract:
  Supernova remnants are likely to be the accelerators of the galactic cosmic
rays. Assuming the correctness of this hypothesis, we develop a method to
extract the parent cosmic ray spectrum from the VHE gamma ray flux emitted by
supernova remnants (and other gamma transparent sources). Namely, we calculate
semi-analytically the (inverse) operator which relates an arbitrary gamma ray
flux to the parent cosmic ray spectrum, without relying on any theoretical
assumption about the shape of the cosmic ray and/or photon spectrum. We
illustrate the use of this technique by applying it to the young SNR RX
J1713.7-3946 which has been observed by H.E.S.S. experiment during the last
three years. Specific implementations of the method permit to use as an input
either the parameterized VHE gamma ray flux or directly the raw data. The
possibility to detect features in the cosmic rays spectrum and the error in the
determination of the parent cosmic ray spectrum are also discussed.


title: Dark Matter

abstract:
  The nature of the main constituents of the mass of the universe is one of the
outstanding riddles of cosmology and astro-particle physics. Current models
explaining the evolution of the universe, and measurements of the various
components of its mass, all have in common that an appreciable contribution to
that mass is non-luminous and non-baryonic, and that a large fraction of this
so-called dark matter must be in the form of non-relativistic massive particles
(Cold Dark Matter: CDM). In the spirit of the Lake Louise Winter Institute
Lectures we take a look at the latest astronomical discoveries and report on
the status of direct and indirect Dark Matter searches.


title: Entanglement generation resonances in XY chains

abstract:
  We examine the maximum entanglement reached by an initially fully aligned
state evolving in an XY Heisenberg spin chain placed in a uniform transverse
magnetic field. Both the global entanglement between one qubit and the rest of
the chain and the pairwise entanglement between adjacent qubits is analyzed. It
is shown that in both cases the maximum is not a monotonous decreasing function
of the aligning field, exhibiting instead a resonant behavior for low
anisotropies, with pronounced peaks (a total of [n/2] peaks in the global
entanglement for an $n$-spin chain), whose width is proportional to the
anisotropy and whose height remains finite in the limit of small anisotropy. It
is also seen that the maximum pairwise entanglement is not a smooth function of
the field even in small finite chains, where it may exhibit narrow peaks above
strict plateaus. Explicit analytical results for small chains, as well as
general exact results for finite n-spin chains obtained through the
Jordan-Wigner mapping, are discussed.


title: Parsec-Scale Jet-Environment Interactions in AGN

abstract:
  Observations made with the VLBA have led to fundamental advances in our
understanding of how radio jets in AGN evolve from parsec-scales out to
distances exceeding several hundred kiloparsecs. In this review I discuss
current models of young radio source evolution, as well as the observational
evidence for a rapid change in jet properties on scales of ~1 kpc. A central
topic of current debate is the relative importance of intermittent jet fueling
versus jet-environment interactions in causing a drop-off in powerful radio
sources at this critical evolutionary stage. Recent 3-D hydrodynamical jet
simulations suggest that dense environments and cloud collisions can
temporarily stifle, but not completely halt powerful relativistic jets. Several
VLBA studies of jet-ISM interactions in both blazars and weak Seyfert jets have
indicated that collimated outflows are indeed possible in dense environments.
At present, the bulk of the evidence favors intermittent AGN accretion as the
dominant factor in determining the evolutionary path of large numbers of AGN
jets.


title: Nonlocal Interferometry: Beyond Bell's Inequality

abstract:
  This paper presents a tutorial review of nonlocal interferometry. The role of
the Feynman propagator in optical coherence is also discussed, including the
possibility of generating optical coherence and entanglement outside of the
light cone.


title: Fractional Power Control for Decentralized Wireless Networks

abstract:
  We consider a new approach to power control in decentralized wireless
networks, termed fractional power control (FPC). Transmission power is chosen
as the current channel quality raised to an exponent -s, where s is a constant
between 0 and 1. The choices s = 1 and s = 0 correspond to the familiar cases
of channel inversion and constant power transmission, respectively. Choosing s
in (0,1) allows all intermediate policies between these two extremes to be
evaluated, and we see that usually neither extreme is ideal. We derive
closed-form approximations for the outage probability relative to a target SINR
in a decentralized (ad hoc or unlicensed) network as well as for the resulting
transmission capacity, which is the number of users/m^2 that can achieve this
SINR on average. Using these approximations, which are quite accurate over
typical system parameter values, we prove that using an exponent of 1/2
minimizes the outage probability, meaning that the inverse square root of the
channel strength is a sensible transmit power scaling for networks with a
relatively low density of interferers. We also show numerically that this
choice of s is robust to a wide range of variations in the network parameters.
Intuitively, s=1/2 balances between helping disadvantaged users while making
sure they do not flood the network with interference.


title: Alternative Approach to 3D Displaying

abstract:
  A method for displaying volumetric images, which exploits our binocular
vision and does not require eyewear, is discussed. The display can be rendered
as a matrix of pivoting micromirrors irradiated by a light beam; each
micromirror focuses its pixel beams to the same point of displayed volumetric
image. 3D perception of image can be achieved by scanning the point of beams
intersection over a virtual surface of displayed image in space.


title: Particle-Hole Symmetry and the $\nu={5/2}$ Quantum Hall State

abstract:
  We discuss the implications of approximate particle-hole symmetry in a
half-filled Landau level in which a paired quantum Hall state forms. We note
that the Pfaffian state is not particle-hole symmetric. Therefore, in the limit
of vanishing Landau level mixing, in which particle-hole transformation is an
exact symmetry, the Pfaffian spontaneously breaks this symmetry. There is a
particle-hole conjugate state, which we call the anti-Pfaffian, which is
degenerate with the Pfaffian in this limit. We observe that strong Landau level
mixing should favor the Pfaffian, but it is an open problem which state is
favored for the moderate Landau level mixing which is present in experiments.
We discuss the bulk and edge physics of the anti-Pfaffian. We analyze a
simplified model in which transitions between analogs of the two states can be
studied in detail. Finally, we discuss experimental implications.


title: Precoding for the AWGN Channel with Discrete Interference

abstract:
  For a state-dependent DMC with input alphabet $\mathcal{X}$ and state
alphabet $\mathcal{S}$ where the i.i.d. state sequence is known causally at the
transmitter, it is shown that by using at most
$|\mathcal{X}||\mathcal{S}|-|\mathcal{S}|+1$ out of
$|\mathcal{X}|^{|\mathcal{S}|}$ input symbols of the Shannon's
\emph{associated} channel, the capacity is achievable. As an example of
state-dependent channels with side information at the transmitter, $M$-ary
signal transmission over AWGN channel with additive $Q$-ary interference where
the sequence of i.i.d. interference symbols is known causally at the
transmitter is considered. For the special case where the Gaussian noise power
is zero, a sufficient condition, which is independent of interference, is given
for the capacity to be $\log_2 M$ bits per channel use. The problem of
maximization of the transmission rate under the constraint that the channel
input given any current interference symbol is uniformly distributed over the
channel input alphabet is investigated. For this setting, the general structure
of a communication system with optimal precoding is proposed.


title:
Entropic Effects in the Very Low Temperature Regime of Diluted Ising
  Spin Glasses with Discrete Couplings

abstract:
  We study link-diluted $\pm J$ Ising spin glass models on the hierarchical
lattice and on a three-dimensional lattice close to the percolation threshold.
We show that previously computed zero temperature fixed points are unstable
with respect to temperature perturbations and do not belong to any critical
line in the dilution-temperature plane. We discuss implications of the presence
of such spurious unstable fixed points on the use of optimization algorithms,
and we show how entropic effects should be taken into account to obtain the
right physical behavior and critical points.


title: Treelets--An adaptive multi-scale basis for sparse unordered data

abstract:
  In many modern applications, including analysis of gene expression and text
documents, the data are noisy, high-dimensional, and unordered--with no
particular meaning to the given order of the variables. Yet, successful
learning is often possible due to sparsity: the fact that the data are
typically redundant with underlying structures that can be represented by only
a few features. In this paper we present treelets--a novel construction of
multi-scale bases that extends wavelets to nonsmooth signals. The method is
fully adaptive, as it returns a hierarchical tree and an orthonormal basis
which both reflect the internal structure of the data. Treelets are especially
well-suited as a dimensionality reduction and feature selection tool prior to
regression and classification, in situations where sample sizes are small and
the data are sparse with unknown groupings of correlated or collinear
variables. The method is also simple to implement and analyze theoretically.
Here we describe a variety of situations where treelets perform better than
principal component analysis, as well as some common variable selection and
cluster averaging schemes. We illustrate treelets on a blocked covariance model
and on several data sets (hyperspectral image data, DNA microarray data, and
internet advertisements) with highly complex dependencies between variables.


title:
Comparison of two formulas for metric connections in the bundle of Dirac
  spinors

abstract:
  Two explicit formulas for metric connections in the bundle of Dirac spinors
are studied. Their equivalence is proved. The explicit formula relating the
spinor curvature tensor with the Riemann curvature tensor is rederived.

categories: math.DG gr-qc hep-ph hep-th math-ph math.MP


title: Particle-hole symmetry and the Pfaffian state

abstract:
  We consider the properties of the Moore-Read Pfaffian state under
particle-hole conjugation. We show that the particle-hole conjugate of the
Pfaffian state - or "anti-Pfaffian" state - is in a different universality
class from the Pfaffian state, with different topological order. The two states
can be distinguished by both their bulk and edge physics though the difference
is most dramatic at the edge: the edge of the anti-Pfaffian state has a
composite structure that leads to a different thermal Hall conductance and
different tunneling exponents than the Pfaffian state. At the same time, the
two states are exactly degenerate in energy for a $\nu = 5/2$ quantum Hall
system in the idealized limit of zero Landau level mixing. Thus, both are good
candidates for the observed $\nu = 5/2$ quantum Hall plateau.


title:
$\mu$--PhotoZ: Photometric Redshifts by Inverting the Tolman Surface
  Brightness Test

abstract:
  Surface brightness is a fundamental observational parameter of galaxies. We
show, for the first time in detail, how it can be used to obtain photometric
redshifts for galaxies, the $\mu$-PhotoZ method.
  We demonstrate that the Tolman surface brightness relation, $\mu \propto
(1+z)^{-4}$, is a powerful tool for determining galaxy redshifts from
photometric data.
  We develop a model using $\mu$ and a color percentile (ranking) measure to
demonstrate the $\mu$-PhotoZ method. We apply our method to a set of galaxies
from the SHELS survey, and demonstrate that the photometric redshift accuracy
achieved using the surface brightness method alone is comparable with the best
color-based methods.
  We show that the $\mu$-PhotoZ method is very effective in determining the
redshift for red galaxies using only two photometric bands. We discuss the
properties of the small, skewed, non-gaussian component of the error
distribution.
  We calibrate $\mu_r, (r-i)$ from the SDSS to redshift, and tabulate the
result, providing a simple, but accurate look up table to estimate the redshift
of distant red galaxies.


title:
Linking the X-ray timing and spectral properties of the glitching AXP
  1RXS J170849-400910

abstract:
  Previous studies of the X-ray flux and spectral properties of 1RXS
J170849-400910 showed hints of a possible correlation with the spin glitches
that occurred in 1999 and 2001. However, due to the sparseness of spectral
measurements and the paucity of detected glitches no firm conclusion could be
drawn. We retrieved and analysed archival XTE pointings of 1RXS J170849-400910
covering the time interval between January 2003 and June 2006 and carried out a
detailed timing analysis by means of phase fitting techniques. We detected two
relatively large glitches Delta nu / nu of 1.2 and 2.1 10^-6 occurred in
January and June 2005. Interestingly, the occurrence times of these glitches
are in agreement with the predictions made in our previous studies. This
finding strongly suggests a connection between the flux, spectral and timing
properties of 1RXS J170849-400910.


title: Blazar Demographics with MOJAVE and GLAST

abstract:
  MOJAVE is a long term VLBA program to investigate the kinematics and
polarization evolution of a complete sample of 133 active galactic nuclei
selected on the basis of compact, relativistically beamed jet emission at 15
GHz. By fitting to the apparent distributions of superluminal speed and jet
luminosity, we can constrain the Lorentz factor distribution and intrinsic
luminosity function of the radio-selected blazar parent population. These
low-energy peaked blazars formed a significant fraction of all EGRET
detections, and should figure prominently in the GLAST source catalog. Using
simple models, we investigate the predicted distribution of GLAST blazars in
the gamma-ray/radio flux density plane, and describe an extension of the MOJAVE
survey that will provide extensive parsec-scale jet information in complete
regions of this plane. We find that if a population of intrinsically radio
bright yet gamma-ray weak blazars exists, its signal will be largely wiped out
by the large gamma-ray flux scatter associated with Doppler beaming.


title: $z$-Classes of Isometries of The Hyperbolic Space

abstract:
  Let $G$ be a group. Two elements $x, y$ are said to be {\it $z$-equivalent}
if their centralizers are conjugate in $G$. The class equation of $G$ is the
partition of $G$ into conjugacy classes. Further decomposition of conjugacy
classes into $z$-classes provides an important information about the internal
structure of the group.
  Let $I(\H^n)$ denote the group of isometries of the hyperbolic $n$-space. We
show that the number of $z$-classes in $I(\H^n)$ is finite. We actually compute
their number, cf. theorem 1.3. We interpret the finiteness of $z$-classes as
accounting for the finiteness of "dynamical types" in $I(\H^n)$. Along the way
we also parametrize conjugacy classes. We mainly use the linear model for the
hyperbolic space for this purpose. This description of parametrizing conjugacy
classes appears to be new.