title: An Alternative Prior Process for Nonparametric Bayesian Clustering

abstract:
  Prior distributions play a crucial role in Bayesian approaches to clustering.
Two commonly-used prior distributions are the Dirichlet and Pitman-Yor
processes. In this paper, we investigate the predictive probabilities that
underlie these processes, and the implicit "rich-get-richer" characteristic of
the resulting partitions. We explore an alternative prior for nonparametric
Bayesian clustering -- the uniform process -- for applications where the
"rich-get-richer" property is undesirable. We also explore the cost of this
process: partitions are no longer exchangeable with respect to the ordering of
variables. We present new asymptotic and simulation-based results for the
clustering characteristics of the uniform process and compare these with known
results for the Dirichlet and Pitman-Yor processes. We compare performance on a
real document clustering task, demonstrating the practical advantage of the
uniform process despite its lack of exchangeability over orderings.


title: Analytic continuation from a family of lines

abstract:
  Given a function f in the exterior of a convex curve in the real plane, we
prove that if the restrictions of f to the tangent lines to the curve extend as
entire functions, then the function f is an entire function of two variables.


title: Asymptotic Stability of Ascending Solitary Magma Waves

abstract:
  Coherent structures, such as solitary waves, appear in many physical
problems, including fluid mechanics, optics, quantum physics, and plasma
physics. A less studied setting is found in geophysics, where highly viscous
fluids couple to evolving material parameters to model partially molten rock,
magma, in the Earth's interior. Solitary waves are also found here, but the
equations lack useful mathematical structures such as an inverse scattering
transform or even a variational formulation.
  A common question in all of these applications is whether or not these
structures are stable to perturbation. We prove that the solitary waves in this
Earth science setting are asymptotically stable and accomplish this without any
pre-exisiting Lyapunov stability. This holds true for a family of equations,
extending beyond the physical parameter space. Furthermore, this extends
existing results on well-posedness to data in a neighborhood of the solitary
waves.


title:
Dynamics of the entanglement between two oscillators in the same
  environment

abstract:
  We provide a complete characterization of the evolution of entanglement
between two oscillators coupled to a common environment. For initial Gaussian
states we identify three phases with different qualitative long time behavior:
There is a phase where entanglement undergoes a sudden death (SD). Another
phase (SDR) is characterized by an infinite sequence of events of sudden death
and revival of entanglement. In the third phase (NSD) there is no sudden death
of entanglement, which persist for long time. The phase diagram is described
and analytic expressions for the boundary between phases are obtained.
Numerical simulations show the accuracy of the analytic expressions. These
results are applicable to a large variety of non--Markovian environments. The
case of non--resonant oscillators is also numerically investigated.


title: The representations of cyclotomic BMW algebras

abstract:
  In this paper, we prove that the cyclotomic BMW algebras B2p+1,n are cellular
in the sense of [16]. We also classify the irreducible B2p+1,nmodules over a
field.


title: Minimality and nonergodicity on a family of flat surfaces in genus 3

abstract:
  We prove that a certain family of flat surfaces in genus 3 does not fulfill
Veech's Dichotomy. These flat surfaces provide uncountably many minimal but
nonergodic directions. The conditions on this family are a combinatorical one
and an irrationality condition. The Arnoux-Yoccoz surface fulfills this
conditions.


title: Large Non-Gaussianity Implication for Curvaton Scenario

abstract:
  We argue that the typical energy density of a light scalar field should not
be less than $H^4$ in the inflationary Universe. This requirement implies that
the non-Gaussianity parameter $f_{NL}$ is typically bounded by the
tensor-scalar ratio $r$ from above, namely $f_{NL}\lesssim 518\cdot r^{1\over
4}$. If $f_{NL}=10^2$, inflation occurred around the GUT scale.


title: Size dependence of the pressure-induced phase transition in nanocrystals

abstract:
  Extending the recently-developed bond-order-length-strength (BOLS)
correlation mechanism [Sun CQ, Prog Solid State Chem 2007, 35, 1-159] to the
pressure domain has led to atomistic insight into the phase stability of
nanostructures under the varied stimuli of pressure and solid size. It turns
out that the competition between the pressure-induced overheating (TC
elevation) and the size-induced undercooling (TC depression) dominates the
measured size trends of the pressure-induced phase transition. Reproduction of
the measured size and pressure dependence of the phase stability for CdSe,
Fe2O3, and SnO2 nanocrystals evidences the validity of the solution derived
from the perspective of atomic cohesive energy and its response to the external
stimulus.


title:
Four qubits Hamiltonian of the Rs. molischianum light-harvesting complex
  II ring

abstract:
  We will construct a simple four qubits Hamiltonian of the Rs. molischianum
purple bacteria light harvesting complex II (LH-II) ring which yields energy
levels that carry the ring's oscillator strength. In an excitonic
representation, these levels are associated with the second and the third
lowest electronic excitations of the ring. We will assume that qubits form a
closed loop lattice and the interaction between qubits is only due to the
exchange effect. As we will show, eigenstates are constructed in a such way
that as we subsequently divide qubits of the Rs. molischianum LH-II ring into
the subsystem A consisting of only one qubit and the subsystem B consisting of
the remaining qubits, respective entropies of entanglement increase until the
value of 1 for the maximally entangled state (bipartite system) is reached.
Since the Hamiltonian in essence introduces a two-level approximation for the
LH-II ring, we will go one step further and assume that interactions between
qubits closed loop lattices and an electromagnetic field are described by the
Jaynes-Cummings Hamiltonian. This assumption is interesting by itself, since it
leads to behavior where the qubits lattice and field oscillate back and fourth
exchanging a quantum of energy, at the Rabbi frequency. This opens a
challenging opportunity to experimentally study the Rs. molischianum LH-II ring
in the regime of cavity QED.


title: Spin-orbit interaction effect on transport of Dirac fermions in graphene

abstract:
  We study theoretically the quantum transport properties of the Dirac fermions
with spin-orbit interactions (SOIs) in graphene by using the method of
Schwinger proper time together with decomposition over Landau level poles and
Kubo formula. The analytical expressions for both longitudinal and Hall
conductivities are derived explicitly. It is found that, from some numerical
examples, when the Rashba SOI is taken into account the Shubnikov-de Haas (SdH)
oscillation peaks of the longitudinal conductivity versus the chemical
potential are split, while the SdH oscillation of the longitudinal conductivity
versus a external magnetic field exhibits a beating pattern. Furthermore, the
Rashba SOI tends to suppress the quantum Hall effect in graphene.


title:
The black hole final state for the Dirac fields In Schwarzschild
  spacetime

abstract:
  We show that the internal stationary state of a black hole for massless Dirac
fields can be represented by an entangled state of collapsing matter and
infalling Hawking radiation. This implies that the Horowitz-Maldacena
conjecture for the black hole final state originally proposed for the massless
scalar fields is also applicable to fermionic fields as well. For an initially
mixed state we find that the measure of mixedness is expected to decrease under
evaporation.


title:
Kazhdan-Lusztig Basis and A Geometric Filtration of an affine Hecke
  Algebra, II

abstract:
  An affine Hecke algebras can be realized as an equivariant K-group of the
corresponding Steinberg variety. This gives rise naturally to some two-sided
ideals of the affine Hecke algebra by means of the closures of nilpotent orbits
of the corresponding Lie algebra. In this paper we will show that the two-sided
ideals are in fact the two-sided ideals of the affine Hecke algebra defined
through two-sided cells of the corresponding affine Weyl group after the
two-sided ideals are tensored by rational numbers field. This proves a weak
form of a conjecture of Ginzburg proposed in 1987.


title: Semileptonic $B(B_s, B_c)$ decays in the light-cone QCD sum rules

abstract:
  Semileptonic $B$($B_s, B_c$) decays are investigated systematically in the
light-cone QCD sum rules. Special emphasis is put on the LCSR calculation on
weak form factors with an adequate chiral current correlator, which turns out
to be particularly effective to control the pollution by higher twist
components of spectator mesons. The result for each channel depends on the
distribution amplitude of the the producing meson. The leading twist
distribution amplitudes of the related heavy mesons and charmonium are worked
out by a model approach in the reasonable way. A practical scenario is
suggested to understand the behavior of weak form factors in the whole
kinematically accessible ranges. The decay widths and branching ratios are
estimated for several $B$($B_c$) decay modes of current interest.


title:
Analysis and Counterexamples Regarding Yatsenko's Polynomial-Time
  Algorithm for Solving the Traveling Salesman Problem

abstract:
  Yatsenko gives a polynomial-time algorithm for solving the traveling salesman
problem. We examine the correctness of the algorithm and its construction. We
also comment on Yatsenko's evaluation of the algorithm.


title:
Observation of coherence revival and fidelity saturation in a
  delta-kicked rotor potential

abstract:
  We experimentally investigate the effect of atomic $\delta$-kicked rotor
potentials on the mutual coherence between wavepackets in an atom
interferometer. The differential action of the kicked rotor degrades the mutual
coherence, leading to a reduction of the interferometry fringe visibility;
however, when the repetition rate of the kicked rotor is at or near the quantum
resonance, we observe revival of matter-wave coherence as the number of kicks
increases, resulting in non-vanishing coherence in the large kick number limit.
This coherence saturation effect reflects a saturation of fidelity decay due to
momentum displacements in deep quantum regime. The saturation effect is
accompanied with an invariant distribution of matter-wave coherence under the
kicked rotor perturbations.


title: Impact of Casimir Force in Molecular Electronic Switching Junctions

abstract:
  Despite significant progress in synthesizing several new molecules and many
promising single device demonstrations, wide range acceptance of molecular
electronics as an alternative to CMOS technology has been stalled not only by
controversial theories of a molecular device`s operation, for example the
switching mechanism, but also by our inability to reproducibly fabricate large
arrays of devices. In this paper, we investigate the role of Casimir force as
one of the potential source of a wide range of discrepancies in the reported
electrical characteristics and high rate of device shorting in molecular
electronic switching junctions fabricated by sandwiching a molecular monolayer
between a pair of planar metal electrode.


title: LMC X-3 May Be a Relic of a GRB Similar to Cosmological GRBs

abstract:
  The present scenario for high-luminosity long gamma-ray bursts is strongly
influenced by the paper of Fruchter et al. (2006). Whereas the main contention
of this paper that these GRBs occur in low-metallicity irregular galaxies is
based on a considerable collection of observational results and although the
main thesis is doubtless correct, the paper does not explain the dynamics that
produces such GRBs and much of the discussion not directly concerning the main
thesis is wrong. We propose a dynamics and elucidate how the Fruchter et al.
(2006) results may be tested, in our neighborhood in the LMC, suggesting that
LMC X-3 is a relic of a high luminosity explosion, probably accompanied by a
GRB and hypernova explosion. The way to test our suggestion is to measure the
system velocity of the present black hole. We correct errors of the Fruchter et
al. paper in stellar evolution, so that the study of GRBs is consistent with
it. We show that the subluminous GRB 060218 had a low-mass black hole as
central engine.


title: The $G_2$-MSSM - An $M$ Theory motivated model of Particle Physics

abstract:
  We continue our study of the low energy implications of $M$ theory vacua on
$G_2$ manifolds, undertaken in \cite{Acharya:2007rc,Acharya:2006ia}, where it
was shown that the moduli can be stabilized and a TeV scale generated, with the
Planck scale as the only dimensionful input. A well-motivated phenomenological
model - the $G_2$-MSSM, can be naturally defined within the above framework. In
this paper, we study some of the important phenomenological features of the
$G_2$-MSSM. In particular, the soft supersymmetry breaking parameters and the
superpartner spectrum are computed. The $G_2$-MSSM generically gives rise to
light gauginos and heavy scalars with wino LSPs when one tunes the cosmological
constant. Electroweak symmetry breaking is present but fine-tuned. The
$G_2$-MSSM is also naturally consistent with precision gauge coupling
unification. The phenomenological consequences for cosmology and collider
physics of the $G_2$-MSSM will be reported in more detail soon.


title: Thermal imaging on simulated faults during frictional sliding

abstract:
  Heating during frictional sliding is a major component of the energy budget
of earthquakes and represents a potential weakening mechanism. It is therefore
important to investigate how heat dissipates during sliding on simulated
faults. We present results from laboratory friction experiments where a halite
(NaCl) slider held under constant load is dragged across a coarse substrate.
Surface evolution and frictional resistance are recorded. Heat emission at the
sliding surface is monitored using an infra-red camera. We demonstrate a link
between plastic deformations of halite and enhanced heating characterized by
transient localized heat spots. When sand 'gouge' is added to the interface,
heating is more diffuse. Importantly, when strong asperities concentrate
deformation, significantly more heat is produced locally. In natural faults
such regions could be nucleation patches for melt production and hence
potentially initiate weakening during earthquakes at much smaller sliding
velocities or shear stress than previously thought.


title: Analytic Continuation of q-Euler numbers and polynomials

abstract:
  In this paper we study that the $q$-Euler numbers and polynomials are
analytically continued to $E_q(s)$. A new formula for the Euler's $q$-Zeta
function $\zeta_{E,q}(s)$ in terms of nested series of $\zeta_{E,q}(n)$ is
derived. Finally we introduce the new concept of the dynamics of analytically
continued $q$-Euler numbers and polynomials.


title: On Universal Binary Hermitian Forms

abstract:
  Earnest and Khosravani, Iwabuchi, and Kim and Park recently gave a complete
classification of the universal binary Hermitian forms. We give a unified proof
of the universalities of these Hermitian forms, relying primarily on
Ramanujan's list of universal quadratic forms and on the Bhargava-Hanke
290-Theorem. Our methods bypass nearly all of the ad hoc universality arguments
required in the original classification.


title:
Geometrical properties of the trans-spherical solutions in higher
  dimensions

abstract:
  We investigate the geometrical properties of static vacuum $p$-brane
solutions of Einstein gravity in $D=n+p+3$ dimensions, which have spherical
symmetry of $S^{n+1}$ orthogonal to the $p$-directions and are invariant under
the translation along them. % The solutions are characterized by mass density
and $p$ tension densities. % The causal structure of the higher dimensional
solutions is essentially the same as that of the five dimensional ones. Namely,
a naked singularity appears for most solutions except for the Schwarzschild
black $p$-brane and the Kaluza-Klein bubble. % We show that some important
geometric properties such as the area of $S^{n+1}$ and the total spatial volume
are characterized only by the three parameters such as the mass density, the
sum of tension densities and the sum of tension density squares rather than
individual tension densities. These geometric properties are analyzed in detail
in this parameter space and are compared with those of 5-dimensional case.


title:
Global Gorenstein dimensions of polynomial rings and of direct products
  of rings

abstract:
  In this paper, we extend the well-known Hilbert's syzygy theorem to the
Gorenstein homological dimensions of rings. Also, we study the Gorenstein
homological dimensions of direct products of rings. Our results generate
examples of non-Noetherian rings of finite Gorenstein dimensions and infinite
classical weak dimension.


title:
Anomalous In-Plane Anisotropy of the Onset of Superconductivity in
  (TMTSF)2ClO4

abstract:
  We report the magnetic field-amplitude and field-angle dependence of the
superconducting onset temperature Tc_onset of the organic superconductor
(TMTSF)2ClO4 in magnetic fields H accurately aligned to the conductive ab'
plane. We revealed that the rapid increase of the onset fields at low
temperatures occurs both for H // b' and H // a, irrespective of the carrier
confinement. Moreover, in the vicinity of the Pauli limiting field, we report a
shift of a principal axis of the in-plane field-angle dependence of Tc_onset
away from the b' axis. This feature may be related to an occurrence of
Fulde-Ferrell-Larkin-Ovchinnikov phases.


title:
Towards determining the parameters of layer with scattering
  irregularities that cause coherent echo, based on the Irkutsk Incoherent
  Scatter radar data

abstract:
  In the paper we have presented a technique of determining the scattering
irregularities (that cause coherent echo) layer parameters using the Irkutsk IS
radar data. It is shown that our technique has necessary accuracy (for height
and thickness - about 2.5 km, for aspect sensitivity - 5dB/degree). Processing
of the experiments 25-26.12.1998 and 15-16.07.2000 has shown a good agreement
of data calculated with the data obtained by other investigators: an average
layer height is 110-120km, average layer thickness 5km, average aspect
sensitivity - 15dB/degree. The investigation of the experiments with high
temporal resolution allowed us to observe temporal variations of the
irregularities layer parameters. The average thickness and height of the layer
does not contradict the data obtained by other investigators. The investigation
of the experiments with high temporal resolution allowed to detect time
variations of the layer parameters. The temporal variations of the aspect
sensitivity are observed by us for the first time and requires additional
investigations.


title:
Two-Fluid MHD Simulations of Converging HI Flows in the Interstellar
  Medium. I: Methodology and Basic Results

abstract:
  We develop an unconditionally stable numerical method for solving the
coupling between two fluids (frictional forces/heatings, ionization, and
recombination), and investigate the dynamical condensation process of thermally
unstable gas that is provided by the shock waves in a weakly ionized and
magnetized interstellar medium by using two-dimensional two-fluid
magnetohydrodynamical simulations. If we neglect the effect of magnetic field,
it is known that condensation driven by thermal instability can generate high
density clouds whose physical condition corresponds to molecular clouds
(precursor of molecular clouds). In this paper, we study the effect of magnetic
field on the evolution of supersonic converging HI flows and focus on the case
in which the orientation of magnetic field to converging flows is orthogonal.
We show that the magnetic pressure gradient parallel to the flows prevents the
formation of high density and high column density clouds, but instead generates
fragmented, filamentary HI clouds. With this restricted geometry, magnetic
field drastically diminishes the opportunity of fast molecular cloud formation
directly from the warm neutral medium, in contrast to the case without magnetic
field.


title: Mass measurements of neutron-rich nuclei at JYFLTRAP

abstract:
  The JYFLTRAP mass spectrometer was used to measure the masses of neutron-rich
nuclei in the region between N = 28 to N = 82 with uncertainties better than 10
keV. The impacts on nuclear structure and the r-process paths are reviewed.


title: Patterns of Chaos Synchronization

abstract:
  Small networks of chaotic units which are coupled by their time-delayed
variables, are investigated. In spite of the time delay, the units can
synchronize isochronally, i.e. without time shift. Moreover, networks can not
only synchronize completely, but can also split into different synchronized
sublattices. These synchronization patterns are stable attractors of the
network dynamics. Different networks with their associated behaviors and
synchronization patterns are presented. In particular, we investigate
sublattice synchronization, symmetry breaking, spreading chaotic motifs,
synchronization by restoring symmetry and cooperative pairwise synchronization
of a bipartite tree.


title: Microscopic magnetic dipole radiation in neutron stars

abstract:
  There is ${}^3P_2$ neutron superfluid region in NS (neutron star) interior.
For a rotating NS, the ${}^3P_2$ superfluid region is like a system of rotating
magnetic dipoles. It will give out electromagnetic radiation, which may
provides a new heating mechanism of NSs. This heating mechanism plus some
cooling agent may give sound explanation to NS glitches.


title: ADAFs, accretion discs and outbursts in compact binaries

abstract:
  I discuss the status of the Soft X-ray Transient model. First, I discuss and
then compare with observations the assumption that the geometrically thin disc
evaporates into an ADAF. Second, I address the problems created by the recent
determinations of the distance to SS Cyg, according to which the Disc
Instability Model does not apply to this famous dwarf-nova, thus casting doubt
on the application of this model to any system at all.


title: Neutralino dark matter from heavy axino decay

abstract:
  We consider cosmological consequences of a heavy axino, decaying to the
neutralino in R-parity conserving models. The importance and influence of the
axino decay on the resultant abundance of neutralino dark matter depends on the
lifetime and the energy density of axino. For a high reheating temperature
after inflation, copiously produced axinos dominate the energy density of the
universe and its decay produces a large amount of entropy. As a bonus, we
obtain that the upper bound on the reheating temperature after inflation via
gravitino decay can be moderated, because the entropy production by the axino
decay more or less dilutes the gravitinos.


title: The Formation of Distributed and Clustered Stars in Molecular Clouds

abstract:
  During the last two decades, the focus of star formation research has shifted
from understanding the collapse of a single dense core into a star to studying
the formation hundreds to thousands of stars in molecular clouds. In this
chapter, we overview recent observational and theoretical progress toward
understanding star formation on the scale of molecular clouds and complexes,
i.e the macrophysics of star formation. We begin with an overview of recent
surveys of young stellar objects (YSOs) in molecular clouds and embedded
clusters, and we outline an emerging picture of cluster formation. We then
discuss the role of turbulence to both support clouds and create dense,
gravitationally unstable structures, with an emphasis on the role of magnetic
fields (in the case of distributed stars) and feedback (in the case of
clusters) to slow turbulent decay and mediate the rate and density of star
formation. The discussion is followed by an overview of how gravity and
turbulence may produce observed scaling laws for the properties of molecular
clouds, stars and star clusters, and how the observed, low star formation rate
may result from self regulated star formation. We end with some concluding
remarks, including a number of questions to be addressed by future observations
and simulations.


title:
Single and double inclusive cross-sections for nucleus-nucleus
  collisions in the peryrbative QCD

abstract:
  Single and double inclusive cross-sections in nucleus-nucleus collisions are
derived in the perturbative QCD with interacting BFKL pomerons in the
quasi-classical approximation.


title:
Atomic teleportation via cavity QED and position measurements:
  efficiency analysis

abstract:
  We have recently presented a novel protocol to teleport an unknown atomic
state via cavity QED and position measurements. Here, after a brief review of
our scheme, we provide a quantitative study of its efficiency. This is
accomplished by an explicit description of the measurement process that allows
us to derive the fidelity with respect to the atomic internal state to be
teleported.


title: Toric Ideals of Flow Polytopes

abstract:
  A referee found an error in the proof of the Main Theorem ("toric ideals of
flow polytopes are generated in degree 3") that we could not fix. More
precisely, the proof of Lemma 4.2.(ii) is incorrect.
  The results on Gr\"obner bases are untouched by this.
  -----
  We show that toric ideals of flow polytopes are generated in degree 3. This
was conjectured by Diaconis and Eriksson for the special case of the Birkhoff
polytope. Our proof uses a hyperplane subdivision method developed by Haase and
Paffenholz.
  It is known that reduced revlex Gr\"obner bases of the toric ideal of the
Birkhoff polytope $B_n$ have at most degree $n$. We show that this bound is
sharp for some revlex term orders. For $(m\times n)$-transportation polytopes,
a similar result holds: they have Gr\"obner bases of at most degree $\lfloor
mn/2\rfloor$. We construct a family of examples, where this bound is sharp.


title:
Some examples of absolute continuity of measures in stochastic fluid
  dynamics

abstract:
  A non linear Ito equation in a Hilbert space is studied by means of Girsanov
theorem. We consider a non linearity of polynomial growth in suitable norms,
including that of quadratic type which appears in the Kuramoto-Sivashinsky
equation and in the Navier-Stokes equation. We prove that Girsanov theorem
holds for the 1-dimensional stochastic Kuramoto-Sivashinsky equation and for a
modification of the 2- and 3-dimensional stochastic Navier-Stokes equation. In
this way, we prove existence and uniqueness of solutions for these stochastic
equations. Moreover, the asymptotic behaviour for large time is characterized.


title: Faster quantum walk algorithm for the two dimensional spatial search

abstract:
  We consider the problem of finding a desired item out of $N$ items arranged
on the sites of a two-dimensional lattice of size $\sqrt{N} \times \sqrt{N}$.
The previous quantum walk based algorithms take $O(\sqrt{N}\log N)$ steps to
solve this problem, and it is an open question whether the performance can be
improved. We present a new algorithm which solves the problem in $O(\sqrt{N\log
N})$ steps, thus giving an $O(\sqrt{\log N})$ improvement over the known
algorithms. The improvement is achieved by controlling the quantum walk on the
lattice using an ancilla qubit.


title: S-matrix approach to equation of state of nuclear matter

abstract:
  We calculate the equation of state of nuclear matter based on the general
analysis of the grand canonical partition function in the $S$-matrix framework.
In addition to the low mass stable particles and their two-body scattering
channels considered earlier, the calculation includes systematically all the
higher mass particles and their exited states as well as the scattering
channels formed by any number of these species. We estimate the latter
contribution by resonances in all the channels. The resulting model-independent
virial series for pressure gets substantial contribution from the heavy
particles and the channels containing them. The series converges for larger
values of baryon density than found earlier.


title: Adjusted Bayesian inference for selected parameters

abstract:
  We address the problem of providing inference from a Bayesian perspective for
parameters selected after viewing the data. We present a Bayesian framework for
providing inference for selected parameters, based on the observation that
providing Bayesian inference for selected parameters is a truncated data
problem. We show that if the prior for the parameter is non-informative, or if
the parameter is a "fixed" unknown constant, then it is necessary to adjust the
Bayesian inference for selection. Our second contribution is the introduction
of Bayesian False Discovery Rate controlling methodology,which generalizes
existing Bayesian FDR methods that are only defined in the two-group mixture
model.We illustrate our results by applying them to simulated data and data
froma microarray experiment.


title: Parametrizing recollement data

abstract:
  We give a general parametrization of all the recollement data for a
triangulated category with a set of generators. From this we deduce a
characterization of when a perfectly generated (or aisled) triangulated
category is a recollement of triangulated categories generated by a single
compact object. Also, we use homological epimorphisms of dg categories to give
a complete and explicit description of all the recollement data for (or
smashing subcategories of) the derived category of a k-flat dg category. In the
final part we give a bijection between smashing subcategories of compactly
generated triangulated categories and certain ideals of the subcategory of
compact objects, in the spirit of Henning Krause's work. This bijection implies
the following weak version of the Generalized Smashing Conjecture: in a
compactly generated triangulated category every smashing subcategory is
generated by a set of Milnor colimits of compact objects.


title: Friedberg-Lee Symmetry for Quark Masses and Flavor Mixing

abstract:
  We point out a generic correlation between the Friedberg-Lee symmetry of
quark mass operators and the vanishing of quark masses. We make
phenomenological explorations on two textures of quark mass matrices with the
broken Friedberg-Lee symmetry. We present a new pattern of quark mass matrices
in agreement with current experimental data. Both analytical and numerical
results of our calculations are discussed in detail.


title: Exact solutions for Big Bounce in loop quantum cosmology

abstract:
  In this paper we study the flat (k=0) cosmological FRW model with holonomy
corrections of Loop Quantum Gravity. The considered universe contains a
massless scalar field and the cosmological constant Lambda. We find analytical
solutions for this model in different configurations and investigate its
dynamical behaviour in the whole phase space. We show the explicit influence of
Lambda on the qualitative and quantitative character of solutions. Even in the
case of positive Lambda the oscillating solutions without the initial and final
singularity appear as a generic case for some quantisation schemes.


title: Localized Axion Photon States in a Strong Magnetic Field

abstract:
  We consider the axion field and electromagnetic waves with rapid time
dependence, coupled to a strong time independent, asymptotically approaching a
constant at infinity "mean" magnetic field, which takes into account the back
reaction from the axion field and electromagnetic waves with rapid time
dependence in a time averaged way. The direction of the self consistent mean
field is orthogonal to the common direction of propagation of the axion and
electromagnetic waves with rapid time dependence and parallel to the
polarization of these electromagnetic waves. Then, there is an effective U(1)
symmetry mixing axions and photons. Using the natural complex variables that
this U(1) symmetry suggests we find localized planar soliton solutions. These
solutions appear to be stable since they produce a different magnetic flux than
the state with only a constant magnetic field, which we take as our "ground
state". The solitons also have non trivial U(1) charge defined before,
different from the uncharged vacuum.


title: Quantum triads: an algebraic approach

abstract:
  A concept of quantum triad and its solution is introduced. It represents a
common framework for several situations where we have a quantale with a right
module and a left module, provided with a bilinear inner product. Examples
include Van den Bossche quantaloids, quantum frames, simple and Galois
quantales, operator algebras, or orthomodular lattices.


title: Sharp estimates of the Kobayashi metric and Gromov hyperbolicity

abstract:
  Let D be a smooth relatively compact and strictly J-pseudoconvex domain in a
four dimensional almost complex manifold (M,J). We give sharp estimates of the
Kobayashi metric. Our approach is based on an asymptotic quantitative
description of both the domain D and the almost complex structure J near a
boundary point. Following Z.M.Balogh and M.Bonk, these sharp estimates provide
the Gromov hyperbolicity of the domain D.


title:
First result with AMBER+FINITO on the VLTI: The high-precision angular
  diameter of V3879 Sgr

abstract:
  Our goal is to demonstrate the potential of the interferometric AMBER
instrument linked with the Very Large Telescope Interferometer (VLTI)
fringe-tracking facility FINITO to derive high-precision stellar diameters. We
use commissioning data obtained on the bright single star V3879 Sgr. Locking
the interferometric fringes with FINITO allows us to record very low contrast
fringes on the AMBER camera. By fitting the amplitude of these fringes, we
measure the diameter of the target in three directions simultaneously with an
accuracy of 25 micro-arcseconds. We showed that V3879 Sgr has a round
photosphere down to a sub-percent level. We quickly reached this level of
accuracy because the technique used is independent from absolute calibration
(at least for baselines that fully span the visibility null). We briefly
discuss the potential biases found at this level of precision. The proposed
AMBER+FINITO instrumental setup opens several perspectives for the VLTI in the
field of stellar astrophysics, like measuring with high accuracy the oblateness
of fast rotating stars or detecting atmospheric starspots.


title: On torsion torsionfree triples

abstract:
  We study torsion torsionfree(=TTF) triples in abelian and triangulated
categories. (Notice that TTF triples in a triangulated category are essentially
in bijection with recollement data for this triangulated category.) In
particular, we complete Jans' characterization of split TTF triples on a
category of modules, prove a weak version of the Generalized Smashing
Conjecture, use homological epimorphisms of differential graded(=dg) categories
to give an explicite description of all the TTF triples in the derived category
of a k-flat dg category and develope an unbounded approach to Koenig's theorem
on recollements of right bounded derived categories of ordinary algebras.


title:
Functions of diffraction correction and analytical solutions in
  nonlinear acoustic measurement

abstract:
  This paper presents an analytical formulation for correcting the diffraction
associated to the second harmonic of an acoustic wave, more compact than that
usually used. This new formulation, resulting from an approximation of the
correction applied to fundamental, makes it possible to obtain simple solutions
for the second harmonic of the average acoustic pressure, but sufficiently
precise for measuring the parameter of nonlinearity B/A in a finite amplitude
method. Comparison with other expressions requiring numerical integration, show
the solutions are precise in the nearfield.


title: The quotient of a complete symmetric variety

abstract:
  We study the quotient of a completion of a symmetric variety G/H under the
action of H. We prove that this is isomorphic to the closure of the image of an
isotropic torus under the action of the restricted Weyl group. In the case the
completion is smooth and toroidal we describe the set of semistable points.


title: Molecular cloud abundances and anomalous diffusion

abstract:
  The chemistry of molecular clouds has been studied for decades, with an
increasingly general and sophisticated treatment of the reactions involved. Yet
the treatment of turbulent diffusion has remained extremely sketchy, assuming
simple Fickian diffusion with a scalar diffusivity D. However, turbulent flows
similar to those in the interstellar medium are known to give rise to anomalous
diffusion phenomena, more specifically superdiffusion (increase of the
diffusivity with the spatial scales involved). This paper considers to what
extent and in what sense superdiffusion modifies molecular abundances in
interstellar clouds. For this first exploration of the subject we employ a very
rough treatment of the chemistry and the effect of non-unifom cloud density on
the diffusion equation is also treated in a simplified way. The results
nevertheless clearly demonstrate that the effect of superdiffusion is quite
significant, abundance values at a given radius being modified by order of
unity factors. The sense and character of this influence is highly nontrivial.


title: Exact Haldane mapping for all $S$ and super universality in spin chains

abstract:
  The low energy dynamics of the anti-ferromagnetic Heisenberg spin $S$ chain
in the semiclassical limit $S\to\infty$ is known to map onto the O(3) nonlinear
$\sigma$ model with a $\theta$ term in 1+1 dimension. Guided by the underlying
dual symmetry of the spin chain, as well as the recently established
topological significance of "dangling edge spins," we report an {\em exact}
mapping onto the O(3) model that avoids the conventional large $S$
approximation altogether. Our new methodology demonstrates all the super
universal features of the $\theta$ angle concept that previously arose in the
theory of the quantum Hall effect. It explains why Haldane's original ideas
remarkably yield the correct answer in spite of the fundamental complications
that generally exist in the idea of semiclassical expansions.


title: Geometric algebra and quadrilateral lattices

abstract:
  Motivated by the fundamental results of the geometric algebra we study
quadrilateral lattices in projective spaces over division rings. After giving
the noncommutative discrete Darboux equations we discuss differences and
similarities with the commutative case. Then we consider the fundamental
transformation of such lattices in the vectorial setting and we show the
corresponding permutability theorems. We discuss also the possibility of
obtaining in a similar spirit a noncommutative version of the B-(Moutard)
quadrilateral lattices.


title: Quantum Diffusion and Localization in Disordered Electronic Systems

abstract:
  The diffusion of electronic wave packets in one-dimensional systems with
on-site, binary disorder is numerically investigated within the framework of a
single-band tight-binding model. Fractal properties are incorporated by
assuming that the distribution of distances $\ell$ between consecutive
impurities obeys a power law, $P(\ell) \sim \ell^{-\alpha}$. For suitable
ranges of $\alpha$, one finds system-wide anomalous diffusion. Asymmetric
diffusion effects are introduced through the application of an external
electric field, leading to results similar to those observed in the case of
photogenerated electron-hole plasmas in tilted InP/InGaAs/InP quantum wells.


title:
New results on Noncommutative and Commutative Polynomial Identity
  Testing

abstract:
  Using ideas from automata theory we design a new efficient (deterministic)
identity test for the \emph{noncommutative} polynomial identity testing problem
(first introduced and studied in \cite{RS05,BW05}). We also apply this idea to
the reconstruction of black-box noncommuting algebraic branching programs.
Assuming the black-box model allows us to query the ABP for the output at any
given gate, we can reconstruct an (equivalent) ABP in deterministic polynomial
time. Finally, we explore commutative identity testing when the coefficients of
the input polynomial come from an arbitrary finite commutative ring with unity.


title:
Fabrication and Characterization of Short Josephson Junctions with
  Stepped Ferromagnetic Barrier

abstract:
  We present novel low-T_c superconductor-insulator-ferromagnet-superconductor
(SIFS) Josephson junctions with planar and stepped ferromagnetic interlayer. We
optimized the fabrication process to set a step in the ferromagnetic layer
thickness. Depending on the thickness of the ferromagnetic layer the ground
state of the SIFS junction has a phase drop of either 0 or pi. So-called 0-pi
Josephson junctions, in which 0 and pi ground states compete with each other,
were obtained. These stepped junctions may have a double degenerate ground
state, corresponding to a vortex of supercurrent circulating clock- or
counterclockwise and creating a magnetic flux which carries a fraction of the
magnetic flux quantum \Phi_0. Here, we limit the presentation to static
properties of short junctions.


title: Godel Type Metrics in Einstein-Aether Theory

abstract:
  Aether theory is introduced to implement the violation of the Lorentz
invariance in general relativity. For this purpose a unit timelike vector field
introduced to theory in addition to the metric tensor. Aether theory contains
four free parameters which satisfy some inequalities in order that the theory
to be consistent with the observations. We show that the G{\" o}del type of
metrics of general relativity are also exact solutions of the Einstein-aether
theory. The only field equations are the 3-dimensional Maxwell field equations
and the parameters are left free except $c_{1}-c_{3}=1$.


title:
PT-symmetric knotting of coordinates: a new, topological mechanism of
  quantum confinement

abstract:
  We construct an exactly solvable PT-symmetric example of Sturmian bound
states which exist in the absence of any confining potential. Their origin is
purely topological -- these states live on certain nontrivial contours of
complex coordinates.


title:
Inhomogeneous backflow transformations in quantum Monte Carlo
  calculations

abstract:
  An inhomogeneous backflow transformation for many-particle wave functions is
presented and applied to electrons in atoms, molecules, and solids. We report
variational and diffusion quantum Monte Carlo VMC and DMC energies for various
systems and study the computational cost of using backflow wave functions. We
find that inhomogeneous backflow transformations can provide a substantial
increase in the amount of correlation energy retrieved within VMC and DMC
calculations. The backflow transformations significantly improve the wave
functions and their nodal surfaces.


title: Twisted Yangians and Mickelsson Algebras II

abstract:
  We introduce a skew analogue of the composition of the Cherednik and Drinfeld
functors for twisted Yangians. Our definition is based on the skew Howe
duality, and originates from the centralizer construction of twisted Yangians
due to Olshanski. Using our functor, we establish a correspondence between
intertwining operators on the tensor products of certain modules over twisted
Yangians, and the extremal cocycle on the hyperoctahedral group.


title: The Correlation Between Spectral Index And Accretion Rate For AGN

abstract:
  In this paper, we present a correlation between the spectral index
distribution (SED) and the dimensionless accretion rate defined as
$\dot{m}={L_{bol}/L_{Edd}}$ for AGN. This quantity is used as a substitute of
the physical accretion rate. We select 193 AGN with both broad H$\alpha$ and
broad H$\beta$, and with absorption lines near MgI$\lambda5175\AA$ from SDSS
DR4. We determine the spectral index and dimensionless accretion rate after
correcting for both host galaxy contribution and internal reddening effects. A
correlation is found between the optical spectral index and the dimensionless
accretion rate for AGN, including low luminosity AGN ($L_{H\alpha}<10^{41}{\rm
erg\cdot s^{-1}}$ sometimes called "dwarf AGN" (Ho et al. 1997)). The existence
of this correlation provides an independent method to estimate the central BH
masses for all types of AGN. We also find that there is a different correlation
between the spectral index and the BH masses for normal AGN and low luminosity
AGN, which is perhaps due to the different accretion modes in these two types
of nuclei. This in turn may lead to the different correlations between BH
masses and optical continuum luminosity reported previously (Zhang et al.
2007a), which invalidates the application of the empirical relationship found
by Kaspi et al. (2000, 2005) to low luminosity AGN in order to determine their
BLR sizes.


title: Two kinds of quantum adiabatic approximation

abstract:
  A simple proof of quantum adiabatic theorem is provided. Quantum adiabatic
approximation is divided into two kinds. For Hamiltonian H(t/T), a relation
between the size of the error caused by quantum adiabatic approximation and the
parameter T is given.


title: A remark on amoebas in higher codimensions

abstract:
  It is shown that tube sets over amoebas of algebraic varieties (and, more
generally, of almost periodic holomorphic chains) of dimension q are
q-pseudoconcave in the sense of Rothstein. This is a direct consequence of a
representation of such sets as supports of positive closed currents.


title: Certifying floating-point implementations using Gappa

abstract:
  High confidence in floating-point programs requires proving numerical
properties of final and intermediate values. One may need to guarantee that a
value stays within some range, or that the error relative to some ideal value
is well bounded. Such work may require several lines of proof for each line of
code, and will usually be broken by the smallest change to the code (e.g. for
maintenance or optimization purpose). Certifying these programs by hand is
therefore very tedious and error-prone. This article discusses the use of the
Gappa proof assistant in this context. Gappa has two main advantages over
previous approaches: Its input format is very close to the actual C code to
validate, and it automates error evaluation and propagation using interval
arithmetic. Besides, it can be used to incrementally prove complex mathematical
properties pertaining to the C code. Yet it does not require any specific
knowledge about automatic theorem proving, and thus is accessible to a wide
community. Moreover, Gappa may generate a formal proof of the results that can
be checked independently by a lower-level proof assistant like Coq, hence
providing an even higher confidence in the certification of the numerical code.
The article demonstrates the use of this tool on a real-size example, an
elementary function with correctly rounded output.


title: Self-citation as an impact-reinforcing mechanism in the science system

abstract:
  In previous papers it was demonstrated that lower performance groups have a
larger size-dependent cumulative advantage for receiving citations than
top-performance groups. Furthermore, regardless of performance, larger groups
have less not-cited publications. Particularly for the lower performance groups
the fraction of not-cited publications decreases considerably with size. These
phenomena can be explained with a model in which self-citation acts as a
promotion mechanism for external citations. In this article we show that for
self-citations similar size-dependent scaling rules apply as for citations but
generally the power law exponents are higher for self-citations as compared to
citations. We also find that the fraction of self-citations is smaller for the
higher performance groups and this fraction decreases more rapidly with
increasing journal impact than for lower performance groups. An interesting
novel finding is that the variance in the correlation of the number of
self-citations with size is considerably less than the variance for external
citations. This is a clear indication that size is a stronger determinant for
self-citations than for external citations. Both higher and particularly lower
performance groups have a size-dependent cumulative advantage for
self-citations, but for the higher performance groups only in the lower impact
journals and in fields with low citation density.


title: A New Approach on Constant Angle Surfaces in E^3

abstract:
  In this paper we study constant angle surfaces in Euclidean 3-space. Even
that the result is a consequence of some classical results involving the Gauss
map (of the surface), we give another approach to classify all surfaces for
which the unit normal makes a constant angle with a fixed direction.


title: On the Neron-Severi group of surfaces with many lines

abstract:
  For a binary quartic form $\phi$ without multiple factors, we classify the
quartic K3 surfaces $\phi(x,y)=\phi(z,t)$ whose Neron-Severi group is
(rationally) generated by lines. For generic binary forms $\phi$, $\psi$ of
prime degree without multiple factors, we prove that the Neron-Severi group of
the surface $\phi(x,y)=\psi(z,t)$ is rationally generated by lines.


title: Classical Yang-Mills black hole hair in anti-de Sitter space

abstract:
  The properties of hairy black holes in Einstein-Yang-Mills (EYM) theory are
reviewed, focusing on spherically symmetric solutions. In particular, in
asymptotically anti-de Sitter space (adS) stable black hole hair is known to
exist for su(2) EYM. We review recent work in which it is shown that stable
hair also exists in su(N) EYM for arbitrary N, so that there is no upper limit
on how much stable hair a black hole in adS can possess.


title: A scheme of supraluminal telegraph

abstract:
  This paper has been withdrawn by the author due to the presented idea is
wrong.


title: Scalar Meson Photoproduction

abstract:
  The scalar mesons f0(1370), f0(1500) and f0(1710) are of interest as there is
as yet no consensus of their status, or indeed of the existence of the
f0(1370). Radiative decays to rho and omega have been shown to provide
effective probes of their structure and to discriminate among models.
Scalar-meson photoproduction is proposed as an alternative and it is shown that
it represents a feasible approach.


title: On some bound and scattering states associated with the cosine kernel

abstract:
  It is explained how to provide self-adjoint operators having scattering
states forming a multiplicity one continuum and bound states whose
corresponding eigenvalues have an asymptotic density equivalent to the one of
the zeros of the Riemann zeta function. It is shown how this can be put into an
integro-differential form of a type recently considered by Sierra.


title:
Ac hopping conduction at extreme disorder takes place on the percolating
  cluster

abstract:
  Simulations of the random barrier model show that ac currents at extreme
disorder are carried almost entirely by the percolating cluster slightly above
threshold; thus contradicting traditional theories contributions from isolated
low-activation-energy clusters are negligible. The effective medium
approximation in conjunction with the Alexander-Orbach conjecture leads to an
excellent analytical fit to the universal ac conductivity with no nontrivial
fitting parameters.


title:
Dimension vs. Genus: A surface realization of the little k-cubes and an
  E_{\infty}-operad

abstract:
  We define a new $E_{\infty}$ operad based on surfaces with foliations which
contains $E_k$ sub-operads. We construct CW models for these operads and
provide applications of these models by giving actions on Hochschild complexes
-thus making contact with string topology-, by giving explicit cell
representatives for the Dyer-Lashof-Cohen operations for the 2-cubes and by
constructing new $\Omega$ spectra. The underlying novel principle is that we
can trade genus in the surface representation vs. the dimension $k$ of the
little $k$-cubes.


title: Topology and Ambiguity in Omega Context Free Languages

abstract:
  We study the links between the topological complexity of an omega context
free language and its degree of ambiguity. In particular, using known facts
from classical descriptive set theory, we prove that non Borel omega context
free languages which are recognized by B\"uchi pushdown automata have a maximum
degree of ambiguity. This result implies that degrees of ambiguity are really
not preserved by the operation of taking the omega power of a finitary context
free language. We prove also that taking the adherence or the delta-limit of a
finitary language preserves neither unambiguity nor inherent ambiguity. On the
other side we show that methods used in the study of omega context free
languages can also be applied to study the notion of ambiguity in infinitary
rational relations accepted by B\"uchi 2-tape automata and we get first results
in that direction.


title: On the Length of the Wadge Hierarchy of Omega Context Free Languages

abstract:
  We prove in this paper that the length of the Wadge hierarchy of omega
context free languages is greater than the Cantor ordinal epsilon_omega, which
is the omega-th fixed point of the ordinal exponentiation of base omega. The
same result holds for the conciliating Wadge hierarchy, defined by J. Duparc,
of infinitary context free languages, studied by D. Beauquier. We show also
that there exist some omega context free languages which are
Sigma^0_omega-complete Borel sets, improving previous results on omega context
free languages and the Borel hierarchy.


title:
An omega-Power of a Finitary Language Which is a Borel Set of Infinite
  Rank

abstract:
  Omega-powers of finitary languages are omega languages in the form V^omega,
where V is a finitary language over a finite alphabet X. Since the set of
infinite words over X can be equipped with the usual Cantor topology, the
question of the topological complexity of omega-powers naturally arises and has
been raised by Niwinski, by Simonnet, and by Staiger. It has been recently
proved that for each integer n > 0, there exist some omega-powers of context
free languages which are Pi^0_n-complete Borel sets, and that there exists a
context free language L such that L^omega is analytic but not Borel. But the
question was still open whether there exists a finitary language V such that
V^omega is a Borel set of infinite rank. We answer this question in this paper,
giving an example of a finitary language whose omega-power is Borel of infinite
rank.


title: Chromodynamic Fluctuations in Quark-Gluon Plasma

abstract:
  Fluctuations of chromodynamic fields in the collisionless quark-gluon plasma
are found as a solution of the initial value linearized problem. The plasma
initial state is on average colorless, stationary and homogeneous. When the
state is stable, the initial fluctuations decay exponentially and in the
long-time limit a stationary spectrum of fluctuations is established. For the
equilibrium plasma it reproduces the spectrum which is provided by the
fluctuation-dissipation relation. Fluctuations in the unstable plasma, where
the memory of initial fluctuations is not lost, are also discussed.


title:
On Infinite Real Trace Rational Languages of Maximum Topological
  Complexity

abstract:
  We consider the set of infinite real traces, over a dependence alphabet
(Gamma, D) with no isolated letter, equipped with the topology induced by the
prefix metric. We then prove that all rational languages of infinite real
traces are analytic sets and that there exist some rational languages of
infinite real traces which are analytic but non Borel sets, and even
Sigma^1_1-complete, hence of maximum possible topological complexity.


title: Polyhedral hyperbolic metrics on surfaces

abstract:
  In the last section of \cite{CompHyp} it is proved that the map $\mathcal{I}$
is a finite-sheeted covering map between $\mathcal{P}$ and $\mathcal{M}$. As
$\mathcal{M}$ is simply connected it is deduced that $\mathcal{I}$ is a
homeomorphism. The fact that $\mathcal{P}$ is connected is missing. Here we
provide a proof.


title: Decoherence of the Kondo Singlet Caused by Phase-sensitive Detection

abstract:
  We investigate the dephasing effect of the Kondo singlet in an Aharonov-Bohm
interferometer with a quantum dot coupling to left and right electrodes. By
employing the cluster expansions, the equations of motion of Green functions
are transformed into the corresponding equation of motion of connected Green
functions, which contains the correlation of two conduction electrons beyond
the Lacroix approximation. With the method we show that the Kondo resonance is
suppressed by phase-sensitive detection of Aharonov-Bohm interferometer. Our
numerical results have provided a qualitative explanation with the anomalous
features observed in a recent experiment by Avinun-Kalish \emph{et al}. [Phys.
Rev. Lett. \textbf{92}, 156801 (2004)].


title:
Blind decoding of Linear Gaussian channels with ISI, capacity, error
  exponent, universality

abstract:
  A new straightforward universal blind detection algorithm for linear Gaussian
channel with ISI is given. A new error exponent is derived, which is better
than Gallager's random coding error exponent.


title: Doppler Images and Chromospheric Variability of TWA 6

abstract:
  We present Doppler imaging and Balmer line analysis of the weak-line T Tauri
star TWA 6. Using this data we have made one of the first attempts to measure
differential rotation in a T Tauri star, and the first detection of a slingshot
prominence in such a star. We also show the most direct evidence to date of the
existence of solar-type plages in a star other than the Sun.
  Observations were made over six nights: 11-13th February 2006 and 18-20th
February 2006, when spectra were taken with the UCL Echelle Spectrograph on the
3.9-m Anglo-Australian Telescope. Using least-squares deconvolution to improve
the effective signal--to--noise ratio we produced two Doppler maps. These show
similar features to maps of other rapidly rotating T Tauri stars, i.e. a polar
spot with more spots extending out of it down to equator. Comparison of the two
maps was carried out to measure the differential rotation. Cross-correlation
and parameter fitting indicates that TWA 6 does not have detectable
differential rotation.
  The Balmer emission of the star was studied. The mean H-alpha profile has a
narrow component consistent with rotational broadening and a broad component
extending out to 250km/s. The variability in H-alpha suggests that the
chromosphere has active regions that are cospatial with the spots in the
photosphere, similar to the 'plages' observed on the Sun. In addition the star
has at least one slingshot prominence 3 stellar radii above the surface - the
first such detection in a T Tauri star.


title:
Experimental microstylolites in quartz and modelling of natural
  stylolitic structures

abstract:
  Experimental microstylolites have been observed at stressed contacts between
quartz grains loaded for several weeks in the presence of an aqueous silica
solution, at 350 8C and 50 MPa of differential stress. Stereoscopic analysis of
pairs of SEM images yielded a digital elevation model of the surface of the
microstylolites. Fourier analyses of these microstylolites reveal a self-affine
roughness (with a roughness exponent H of 1.2). Coupled with observations of
close interactions between dissolution pits and stylolitic peaks, these data
illustrate a possible mechanism for stylolite formation. The complex geometry
of stylolite surfaces is imposed by the interplay between the development of
dissolution peaks in preferential locations (fast dissolution pits) and the
mechanical properties of the solid-fluid-solid interfaces. Simple mechanical
modeling expresses the crucial competition that could rule the development of
microstylolites: (i) a stress-related process, modeled in terms of the
stiffness of springs that activate the heterogeneous dissolution rates of the
solid interface, promotes the deflection. In parallel, (ii) the strength of the
solid interface, modeled in terms of the stiffness of a membrane, is equivalent
to a surface tension that limits the deflection and opposes its development.
The modeling produces stylolitic surfaces with characteristic geometries
varying from conical to columnar when both the effect of dissolution-rate
heterogeneity and the strength properties of the rock are taken into account. A
self-affine roughness exponent (Hz1.2) measured on modeled surfaces is
comparable with natural stylolites at small length scale and experimental
microstylolites.


title:
Numerical modeling of carbon dioxide sequestration on the rate of
  pressure solution creep in limestone: Preliminary results

abstract:
  When carbon dioxide (CO2) is injected into an aquifer or a depleted
geological reservoir, its dissolution into solution results in acidification of
the pore waters. As a consequence, the pore waters become more reactive, which
leads to enhanced dissolution-precipitation processes and a modification of the
mechanical and hydrological properties of the rock. This effect is especially
important for limestones given that the solubility and reactivity of carbonates
is strongly dependent on pH and the partial pressure of CO2. The main mechanism
that couples dissolution, precipitation and rock matrix deformation is commonly
referred to as intergranular pressure solution creep (IPS) or pervasive
pressure solution creep (PSC). This process involves dissolution at
intergranular grain contacts subject to elevated stress, diffusion of dissolved
material in an intergranular fluid, and precipitation in pore spaces subject to
lower stress. This leads to an overall and pervasive reduction in porosity due
to both grain indentation and precipitation in pore spaces. The percolation of
CO2-rich fluids may influence on-going compaction due to pressure solution and
can therefore potentially affect the reservoir and its long-term CO2 storage
capacity. We aim at quantifying this effect by using a 2D numerical model to
study the coupling between dissolution-precipitation processes, local mass
transfer, and deformation of the rock over long time scales. We show that high
partial pressures of dissolved CO2 (up to 30 MPa) significantly increase the
rates of compaction by a factor of ~ 50 to ~ 75, and also result in a
concomitant decrease in the viscosity of the rock matrix.


title:
High resolution 3D laser scanner measurements of a strike-slip fault
  quantify its morphological anisotropy at all scales

abstract:
  The surface roughness of a recently exhumed strikeslip fault plane has been
measured by three independent 3D portable laser scanners. Digital elevation
models of several fault surface areas, from 1 m2 to 600 m2, have been measured
at a resolution ranging from 5 mm to 80 mm. Out of plane height fluctuations
are described by non-Gaussian distribution with exponential long range tails.
Statistical scaling analyses show that the striated fault surface exhibits
self-affine scaling invariance with a small but significant directional
morphological anisotropy that can be described by two scaling roughness
exponents, H1 = 0.7 in the direction of slip and H2 = 0.8 perpendicular to the
direction of slip.


title:
Characterisation of hydraulic fractures in limestones using X-ray
  microtomography

abstract:
  Hydraulic tension fractures were produced in porous limestones using a
specially designed hydraulic cell. The 3D geometry of the samples was imaged
using X-ray computed microtomography before and after fracturation. Using these
data, it was possible to estimate the permeability tensor of the core samples,
extract the path of the rupture and compare it to the heterogeneities initially
present in the rock.


title:
Variety of stylolites morphologies and statistical characterization of
  the amount of heterogeneities in the rock

abstract:
  The surface roughness of several stylolites in limestones was measured using
high resolution laser profilometry. The 1D signals obtained were statistically
analyzed to determine the scaling behavior and calculate a roughness exponent,
also called Hurst exponent. Statistical methods based on the characterization
of a single Hurst exponent imply strong assumptions on the mathematical
characteristics of the signal: the derivative of the signal (or local
increments) should be stationary and have finite variance. The analysis of the
measured stylolites show that these properties are not always verified
simultaneously. The stylolite profiles show persistence and jumps and several
stylolites are not regular, with alternating regular and irregular portions. A
new statistical method is proposed here, based on a non-stationary but Gaussian
model, to estimate the roughness of the profiles and quantify the heterogeneity
of stylolites. This statistical method is based on two parameters: the local
roughness (H) which describes the local amplitude of the stylolite, and the
amount of irregularities on the signal (\mu), which can be linked to the
heterogeneities initially present in the rock before the stylolite formed.
Using this technique, a classification of the stylolites in two families is
proposed: those for which the morphology is homogeneous everywhere and those
with alternating regular and irregular portions.


title:
The impact of Galactic synchrotron emission on CMB anisotropy
  measurements. I. Angular power spectrum analysis of total intensity all-sky
  surveys

abstract:
  Galactic foreground emission is a limiting factor for precise cosmic
microwave background (CMB) anisotropy measurements. We perform an angular power
spectrum analysis (APS) of all-sky total intensity maps at 408 MHz and 1420
MHz, which are dominated by synchrotron emission out of the Galactic plane. We
subtract the brighter sources from the maps. We study the APS as a function of
Galactic latitude by considering various cuts and as a function of sky position
by dividing the sky into patches of about 15 deg x 15 deg in size. The APS of
the Galactic radio diffuse synchrotron emission is best fitted by a power law,
$C_{\ell} \sim k \ell^{\alpha}$, with $\alpha \in [-3.0,-2.6]$, where the lower
values of $\alpha$ typically correspond to the higher latitudes. Nevertheless,
the analysis of the patches reveals that strong local variations exist. The
mean APS for $\ell \in [20,40]$ is used to determine the mean spectral index
between 408 MHz and 1420 MHz, which is then adopted to extrapolate the
synchrotron APS results to the microwave range. A simple extrapolation to 23
GHz of the synchrotron emission APS found at 408 and 1420 MHz does not explain
all the power in the WMAP synchrotron component even at middle/high Galactic
latitudes. This suggests a significant microwave contribution (of about 50% of
the signal) by other components such as free-free or spinning dust emission.
The comparison between the extrapolated synchrotron APS and the CMB APS shows
that a mask excluding the regions with $|b_{gal}| \lesssim 5^{\circ}$ would
reduce the foreground fluctuations to about half of the cosmological ones at 70
GHz even at the lowest multipoles. We discuss the main implications of our
analysis for the cosmological exploitation of microwave temperature anisotropy
maps.


title:
Albite feldspar dissolution kinetics as a function of the Gibbs free
  energy at high pCO_2

abstract:
  We are currently measuring the dissolution kinetics of albite feldspar at 100
deg C in the presence of high levels of dissolved CO_2 (pCO_2 = 9 MPa) as a
function of the saturation state of the feldspar (Gibbs free energy of
reaction, \Delta G). The experiments are conducted using a flow through
reactor, thereby allowing the dissolution reactions to occur at a fixed pH and
at constant, but variable saturation states. Preliminary results indicate that
at far-from-equilibrium conditions, the dissolution kinetics of albite are
defined by a rate plateau, with R \approx 5.0 x 10^{-10} mol m^{-2} s^{-1} at
-70 < \Delta G < -40 kJ mol^{-1}. At \Delta G > -40 kJ mol^{-1}, the rates
decrease sharply, revealing a strong inverse relation between the dissolution
rate and free energy. Based on the experiments carried out to date, the
dissolution rate-free energy data correspond to a highly non-linear and
sigmoidal relation, in accord with recent studies.


title: Spin orbit precession damping in transition metal ferromagnets

abstract:
  We provide a simple explanation, based on an effective field, for the
precession damping rate due to the spin-orbit interaction. Previous effective
field treatments of spin-orbit damping include only variations of the state
energies with respect to the magnetization direction, an effect referred to as
the breathing Fermi surface. Treating the interaction of the rotating spins
with the orbits as a perturbation, we include also changes in the state
populations in the effective field. In order to investigate the quantitative
differences between the damping rates of iron, cobalt, and nickel, we compute
the dependence of the damping rate on the density of states and the spin-orbit
parameter. There is a strong correlation between the density of states and the
damping rate. The intraband terms of the damping rate depend on the spin-orbit
parameter cubed while the interband terms are proportional to the spin-orbit
parameter squared. However, the spectrum of band gaps is also an important
quantity and does not appear to depend in a simple way on material parameters.


title: Is there a measurement-only version of quantum mechanics?

abstract:
  Tensor universality often implies that multi-partite quantum-state processing
is determined by what happens in totally disentangled cases. In independent
systems relative time direction for the parts is arbitrary. This hints that
time may be linked to entanglement and measurements and that there may be a
measurement-only version of quantum mechanics. One-way quantum computation
suggests that this may be possible.


title:
Maximum and entropic repulsion for a Gaussian membrane model in the
  critical dimension

abstract:
  We consider the real-valued centered Gaussian field on the four-dimensional
integer lattice, whose covariance matrix is given by the Green's function of
the discrete Bilaplacian. This is interpreted as a model for a semiflexible
membrane. $d=4$ is the critical dimension for this model. We discuss the effect
of a hard wall on the membrane, via a multiscale analysis of the maximum of the
field. We use analytic and probabilistic tools to describe the correlation
structure of the field.


title: A new standard model of the universe

abstract:
  Analytical properties of a flat universe with cold matter and vacuum energy
is presented.


abstract:
  Ricci flow deformation of cosmological initial data sets in general
relativity is a technique for generating families of initial data sets which
potentially would allow to interpolate between distinct spacetimes. This idea
has been around since the appearance of the Ricci flow on the scene, but it has
been difficult to turn it into a sound mathematical procedure. In this
expository talk we illustrate, how Perelman's recent results in Ricci flow
theory can considerably improve on such a situation. From a physical point of
view this analysis can be related to the issue of finding a constant-curvature
template spacetime for the inhomogeneous Universe, relevant to the
interpretation of observational data and, hence, bears relevance to the dark
energy and dark matter debates. These techniques provide control on curvature
fluctuations (intrinsic backreaction terms) in their relation to the averaged
matter distribution.


title: Likelihood Analysis of CMB Temperature and Polarization Power Spectra

abstract:
  Microwave background temperature and polarization observations are a powerful
way to constrain cosmological parameters if the likelihood function can be
calculated accurately. The temperature and polarization fields are correlated,
partial sky coverage correlates power spectrum estimators at different ell, and
the likelihood function for a theory spectrum given a set of observed
estimators is non-Gaussian. An accurate analysis must model all these
properties. Most existing likelihood approximations are good enough for a
temperature-only analysis, however they cannot reliably handle a
temperature-polarization correlations. We give a new general approximation
applicable for correlated Gaussian fields observed on part of the sky. The
approximation models the non-Gaussian form exactly in the ideal full-sky limit
and is fast to evaluate using a pre-computed covariance matrix and set of power
spectrum estimators. We show with simulations that it is good enough to obtain
correct results at ell >~ 30 where an exact calculation becomes impossible. We
also show that some Gaussian approximations give reliable parameter constraints
even though they do not capture the shape of the likelihood function at each
ell accurately. Finally we test the approximations on simulations with
realistically anisotropic noise and asymmetric foreground mask.


title: On a Hamiltonian PDE arising in Magma Dynamics

abstract:
  In this article we discuss a new Hamiltonian PDE arising from a class of
equations appearing in the study of magma, partially molten rock, in the
Earth's interior. Under physically justifiable simplifications, a scalar,
nonlinear, degenerate, dispersive wave equation may be derived to describe the
evolution of $\phi$, the fraction of molten rock by volume, in the Earth. These
equations have two power nonlinearities which specify the constitutive
realitions for bulk viscosity and permeability in terms of $\phi$. Previously,
they have been shown to admit solitary wave solutions. For a particular
relation between exponents, we observe the equation to be Hamiltonian; it can
be viewed as a generalization of the Benjamin-Bona-Mahoney equation.
  We prove that the solitary waves are nonlinearly stable, by showing that they
are constrained local minimizers of an appropriate time-invariant Lyapunov
functional. A consequence is an extension of the regime of global in time
well-posedness for this class of equations to (large) data, which include a
neighborhood of a solitary wave. Finally, we observe that these equations have
{\it compactons}, solitary traveling waves with compact spatial support at each
time.


title: Sur les ensembles d'entiers reconnaissables

abstract:
  Let U and V be two Bertrand numeration systems, and, a and b the two Parry
numbers there are naturally associated with. Suppose they are multiplicatively
independent. We prove that, if E is a subset of positive integers which is both
U and V recognizable, then E is a finite union of arithmetical progressions.


title: The connection between mass loss and nucleosynthesis

abstract:
  I discuss the relationship between mass loss and nucleosynthesis on the
Asymptotic Giant Branch (AGB). Because of thermal pulses and possibly other
mixing processes, products of nucleosynthesis can be brought to the surface of
AGB stars, increasingly so as the star becomes more luminous, cooler, and
unstable against pulsation of its tenuous mantle. As a result, mass loss is at
its most extreme when dredge-up is too. As the high rate of mass loss truncates
AGB evolution, it determines the enrichment of interstellar space with the AGB
nucleosynthesis products. The changing composition of the stellar atmosphere
also affects the mass-loss process, most obviously in the formation of dust
grains - which play an important role in driving the wind of AGB stars.


title: Words and morphisms with Sturmian erasures

abstract:
  We say $x \in \{0,1,2 \}^{\NN}$ is a word with Sturmian erasures if for any
$a\in \{0,1,2 \}$ the word obtained erasing all $a$ in $x$ is a Sturmian word.
A large family of such words is given coding trajectories of balls in the game
of billiards in the cube. We prove that the monoid of morphisms mapping all
words with Sturmian erasures to words with Sturmian erasures is not finitely
generated.


title:
Failure patterns caused by localized rise in pore-fluid overpressure and
  effective strength of rocks

abstract:
  In order to better understand the interaction between pore-fluid overpressure
and failure patterns in rocks we consider a porous elasto-plastic medium in
which a laterally localized overpressure line source is imposed at depth below
the free surface. We solve numerically the fluid filtration equation coupled to
the gravitational force balance and poro-elasto-plastic rheology equations.
Systematic numerical simulations, varying initial stress, intrinsic material
properties and geometry, show the existence of five distinct failure patterns
caused by either shear banding or tensile fracturing. The value of the critical
pore-fluid overpressure at the onset of failure is derived from an analytical
solution that is in excellent agreement with numerical simulations. Finally, we
construct a phase-diagram that predicts the domains of the different failure
patterns and at the onset of failure.


title:
Influence of time, temperature, confining pressure and fluid content on
  the experimental compaction of spherical grains

abstract:
  Theoretical models of compaction processes, such as for example intergranular
pressure-solution (IPS), focus on deformation occurring at the contacts between
spherical grains that constitute an aggregate. In order to investigate the
applicability of such models, and to quantify the deformation of particles
within an aggregate, isostatic experiments were performed in cold-sealed
vessels on glass sphere aggregates at 200 MPa confining pressure and 350
degrees C with varying amounts of fluid.


title: Ortho-para transition in molecular hydrogen

abstract:
  The radiative ortho-para transition in the molecular hydrogen is studied.
This highly forbidden transition is very sensitive to relativistic and subtle
nonadiabatic effects. Our result for the transition rate in the ground
vibrational level $\Gamma(J=1\to J=0) = 6.20(62)\cdot 10^{-14} \iyr$ is
significantly lower in comparison to all the previous approximate calculations.
Experimental detection of such a weak line by observation of, for example, the
cold interstellar molecular hydrogen is at present unlikely.


title: Radiative energy transfer in disordered photonic crystals

abstract:
  The difficulty of description of the radiative transfer in disordered
photonic crystals arises from the necessity to consider on the equal footing
the wave scattering by periodic modulations of the dielectric function and by
its random inhomogeneities. We resolve this difficulty by approaching this
problem from the standpoint of the general multiple scattering theory in media
with arbitrary regular profile of the dielectric function. We use the general
asymptotic solution of the Bethe-Salpeter equation in order to show that for a
sufficiently weak disorder the diffusion limit in disordered photonic crystals
is presented by incoherent superpositions of the modes of the ideal structure
with weights inversely proportional to the respective group velocities. The
radiative transfer and the diffusion equations are derived as a relaxation of
long-scale deviations from this limiting distribution. In particular, it is
shown that in general the diffusion is anisotropic unless the crystal has
sufficiently rich symmetry, say, the square lattice in 2D or the cubic lattice
in 3D. In this case, the diffusion is isotropic and only in this case the
effect of the disorder can be characterized by the single mean-free-path
depending on frequency.


title: Single-File diffusion in a Box

abstract:
  We study diffusion of (fluorescently) tagged hard-core interacting particles
of finite size in a finite one-dimensional system. We find an exact analytical
expression for the tagged particle probability density using a coordinate
Bethe-ansatz, from which the mean square displacement is calculated. The
analysis show the existence of three regimes of drastically different behavior
for short, intermediate and large times. The results show excellent agreement
with stochastic simulations (Gillespie algorithm). The findings of the Letter
holds promise for the development of novel bio-nano sensors.


title: Hamiltonian handleslides for Heegaard Floer homology

abstract:
  A $g$-tuple of disjoint, linearly independent circles in a Riemann surface of
genus $g$ determines a `Heegaard torus' in its $g$-fold symmetric product.
Changing the circles by a handleslide produces a new torus. It is proved that,
for symplectic forms with certain properties, these two tori are
Hamiltonian-isotopic Lagrangian submanifolds. This provides an alternative
route to the handleslide-invariance of Ozsvath-Szabo's Heegaard Floer homology.


title:
Statistical Properties of the Inter-occurrence Times in the
  Two-dimensional Stick-slip Model of Earthquakes

abstract:
  We study earthquake interval time statistics, paying special attention to
inter-occurrence times in the two-dimensional (2D) stick-slip (block-slider)
model. Inter-occurrence times are the time interval between successive
earthquakes on all faults in a region. We select stiffness and friction
parameters as tunable parameters because these physical quantities are
considered as essential factors in describing fault dynamics. It is found that
inter-occurrence time statistics depend on the parameters. Varying stiffness
and friction parameters systematically, we optimize these parameters so as to
reproduce the inter-occurrence time statistics in natural seismicity. For an
optimal case, earthquakes produced by the model obey the Gutenberg-Richter law,
which states that the magnitude-frequency distribution exhibits the power law
with an exponent approximately unity.


title:
The gluon and ghost propagators in Euclidean Yang-Mills theory in the
  maximal Abelian gauge: taking into account the effects of the Gribov copies
  and of the dimension two condensates

abstract:
  The infrared behavior of the gluon and ghost propagators is studied in SU(2)
Euclidean Yang-Mills theory in the maximal Abelian gauge within the
Gribov-Zwanziger framework. The nonperturbative effects associated with the
Gribov copies and with the dimension two condensates are simultaneously encoded
into a local and renormalizable Lagrangian. The resulting behavior turns out to
be in good agreement with the lattice data.


title:
Crystal growth and ambient and high pressure study of the reentrant
  superconductor Tm_2Fe_3Si_5

abstract:
  We report single crystal growth of the reentrant superconductor Tm_2Fe_3Si_5,
and measurements of the anisotropic static magnetic susceptibility \chi(T) and
isothermal magnetization M(H), ac susceptibility \chi_ac(T), electrical
resistivity \rho(T) and heat capacity C(T) at ambient pressure and \chi_ac(T)
at high pressure. The magnetic susceptibility along the c-axis \chi_c(T) shows
a small maximum around 250 K and does not follow the Curie-Weiss behavior while
the magnetic susceptibility along the a-axis \chi_a(T) follows a Curie-Weiss
behavior between 130 K and 300 K with a Weiss temperature \theta and an
effective magnetic moment \mu_eff which depend on the temperature range of the
fit. The easy axis of magnetization is perpendicular to the c-axis and
\chi_a/\chi_c = 3.2 at 1.8 K. The ambient pressure \chi_ac(T) and C(T)
measurements confirm bulk antiferromagnetic ordering at T_N = 1.1 K. The sharp
drop in \chi_ac below T_N is suggestive of the existence of a spin-gap. We
observe superconductivity only under applied pressures P\geq 2 kbar. The
temperature-pressure phase diagram showing the non-monotonic dependence of the
superconducting transition temperature T_c on pressure P is presented.


title: Counting One-Vertex Maps

abstract:
  The number of distinct maps (pre-maps) with a single vertex and valence $d$
is computed for any value of $d$. The types of maps (pre-maps) that we consider
depend on whether the underlaying graph (pre-graph) is signed or unsigned and
directed or undirected.


title: A search for rapid pulsations among 9 luminous Ap stars

abstract:
  The rapidly oscillating Ap stars are of importance for studying the
atmospheric structure of stars where the process of chemical element diffusion
is significant. We have performed a survey for rapid oscillations in a sample
of 9 luminous Ap stars, selected from their location in the colour-magnitude
diagram as more evolved main-sequence Ap stars that are inside the instability
strip for rapidly oscillating Ap (roAp) stars. Until recently this region was
devoid of stars with observed rapid pulsations. We used the VLT UV-Visual
Echelle Spectrograph (UVES) to obtain high time resolution spectroscopy to make
the first systematic spectroscopic search for rapid oscillations in this region
of the roAp instability strip. We report 9 null-detections with upper limits
for radial-velocity amplitudes of 20 - 65 m/s and precisions of 7 - 20 m/s for
combinations of Nd and Pr lines. Cross-correlations confirm these null-results.
At least six stars are magnetic and we provide magnetic field measurements for
four of them, of which three are newly discovered magnetic stars. It is found
that four stars have magnetic fields smaller than ~ 2 kG, which according to
theoretical predictions might be insufficient for suppressing envelope
convection around the magnetic poles for more evolved Ap stars. Suppression of
convection is expected to be essential for the opacity mechanism acting in the
hydrogen ionisation zone to drive the high-overtone roAp pulsations
efficiently. Our null-results suggest that the more evolved roAp stars may
require particularly strong magnetic fields to pulsate. Three of the studied
stars do, however, have magnetic fields stronger than 5 kG.


title:
Sampling-Based Resolution-Complete Algorithms for Safety Falsification
  of Linear Systems

abstract:
  In this paper, we describe a novel approach for checking safety
specifications of a dynamical system with exogenous inputs over infinite time
horizon that is guaranteed to terminate in finite time with a conclusive
answer. We introduce the notion of resolution completeness for analysis of
safety falsification algorithms and propose sampling-based resolution-complete
algorithms for safety falsification of linear time-invariant discrete time
systems over infinite time horizon. The algorithms are based on deterministic
incremental search procedures, exploring the reachable set for feasible counter
examples to safety at increasing resolution levels of the input. Given a target
resolution of inputs, the algorithms are guaranteed to terminate either with a
reachable state that violates the safety specification, or prove that no input
exists at the given resolution that violates the specification.


title:
Optical alignment and polarization conversion of neutral exciton spin in
  individual InAs/GaAs quantum dots

abstract:
  We investigate exciton spin memory in individual InAs/GaAs self-assembled
quantum dots via optical alignment and conversion of exciton polarization in a
magnetic field. Quasiresonant phonon-assisted excitation is successfully
employed to define the initial spin polarization of neutral excitons. The
conservation of the linear polarization generated along the bright exciton
eigenaxes of up to 90% and the conversion from circular- to linear polarization
of up to 47% both demonstrate a very long spin relaxation time with respect to
the radiative lifetime. Results are quantitatively compared with a model of
pseudo-spin 1/2 including heavy-to-light hole mixing.


title: Strangeness enhancement at LHC

abstract:
  We study production of strangeness in the hot QGP fireball in conditions
achieved at LHC, and use these results to obtain soft (strange) hadron
multiplicities. We compare the chemical equilibrium and non-equilibrium
conditions and identify characteristic experimental observables.


title:
Marginally Deformed Rolling Tachyon around the Tachyon Vacuum in Open
  String Field Theory

abstract:
  We investigate the string field theory around the tachyon vacuum. A pure
gauge form of the solution is constructed at the tachyon vacuum. For a special
choice of the gauge function for the pure gauge form, marginal deformation from
the tachyon vacuum is allowed due to the nontrivial roles of Schnabl's analytic
vacuum solution. We obtain an exact rolling tachyon solution which describes
the late time behaviors of D-brane decay.


title: Polar orthogonal representations of real reductive algebraic groups

abstract:
  We prove that a polar orthogonal representation of a real reductive algebraic
group has the same closed orbits as the isotropy representation of a
pseudo-Riemannian symmetric space. We also develop a partial structural theory
of polar orthogonal representations of real reductive algebraic groups which
slightly generalizes some results of the structural theory of real reductive
Lie algebras.


title:
A Flexible and Secure Remote Systems Authentication Scheme Using Smart
  Cards

abstract:
  The paper presents an authentication scheme for remote systems using smart
card. The scheme prevents the scenario of many logged in users with the same
login identity, and does not require password/verifier table to validate the
users' login request. The scheme provides a user-friendly password change
option, and withstands the replay, impersonation, stolen-verifier, guessing,
and denial-of-service attacks.


title: Electron transmission and phase time in semiconductor superlattices

abstract:
  We discuss the time spent by an electron propagating through a finite
periodic system such as a semiconductor superlattice. The relation between
dwell-time and phase-time is outlined. The envelopes of phase-time at maximum
and minimum transmission are derived, and it is shown that the peaks and
valleys of phase-time can be well described by parameters fitted at the
extrema. For a many-period system this covers most of the allowed band.
Comparison is made to direct numerical solutions of the time-dependent
Schr\"odinger equation by Veenstra et al. [cond-mat/0411118] who compared
systems with and without addition of an anti-reflection coating (ARC). With an
ARC, the time delay is consistent with propagation at the Bloch velocity of the
periodic system, which significantly reduces the time delay, in addition to
increasing the transmissivity.


title:
Magnetically-controlled velocity selection in a cold atom sample using
  stimulated Raman transitions

abstract:
  We observe velocity-selective two-photon resonances in a cold atom cloud in
the presence of a magnetic field. We use these resonances to demonstrate a
simple magnetometer with sub-mG resolution. The technique is particularly
useful for zeroing the magnetic field and does not require any additional laser
frequencies than are already used for standard magneto-optical traps. We verify
the effects using Faraday rotation spectroscopy.


title: On Anomaly Mediated SUSY Breaking

abstract:
  A discrepancy between the Anomaly Mediated Supersymmetry Breaking (AMSB)
gaugino mass calculated from the work of Kaplunovsky and Louis (hep-th/9402005)
(KL) and other calculations in the literature is explained, and it is argued
that the KL expression is the correct one relevant to the Wilsonian action.
Furthermore it is argued that the AMSB contribution to the squark and slepton
masses should be replaced by the contribution pointed out by Dine and Seiberg
(DS) which has nothing to do with Weyl anomalies. This is not in general
equivalent to the AMSB expression, and it is shown that there are models in
which the usual AMSB expression would vanish but the DS one is non-zero. In
fact the latter has aspects of both AMSB and gauge mediated SUSY breaking. In
particular like the latter, it gives positive squared masses for sleptons.


title: Discrete bidding games

abstract:
  We study variations on combinatorial games in which, instead of alternating
moves, the players bid with discrete bidding chips for the right to determine
who moves next. We consider both symmetric and partisan games, and explore
differences between discrete bidding games and Richman games, which allow
real-valued bidding. Unlike Richman games, discrete bidding game variations of
many familiar games, such as chess, Connect Four, and even Tic-Tac-Toe, are
suitable for recreational play. We also present an analysis of Tic-Tac-Toe for
both discrete and real-valued bidding.


title:
Pure Spinor Superspace Identities for Massless Four-point Kinematic
  Factors

abstract:
  Using the pure spinor formalism we prove identities which relate the
tree-level, one-loop and two-loop kinematic factors for massless four-point
amplitudes. From these identities it follows that the complete supersymmetric
one- and two-loop amplitudes are immediately known once the tree-level
kinematic factor is evaluated. In particular, the two-loop equivalence with the
RNS formalism (up to an overall coefficient) is obtained as a corollary.


title:
Capacity of The Discrete-Time Non-Coherent Memoryless Rayleigh Fading
  Channels at Low SNR

abstract:
  The capacity of a discrete-time memoryless channel, in which successive
symbols fade independently, and where the channel state information (CSI) is
neither available at the transmitter nor at the receiver, is considered at low
SNR. We derive a closed form expression of the optimal capacity-achieving input
distribution at low signal-to-noise ratio (SNR) and give the exact capacity of
a non-coherent channel at low SNR. The derived relations allow to better
understanding the capacity of non-coherent channels at low SNR and bring an
analytical answer to the peculiar behavior of the optimal input distribution
observed in a previous work by Abou Faycal, Trott and Shamai. Then, we compute
the non-coherence penalty and give a more precise characterization of the
sub-linear term in SNR. Finally, in order to better understand how the optimal
input varies with SNR, upper and lower bounds on the capacity-achieving input
are given.


title: Composition of Primary Cosmic-Ray Nuclei at High Energies

abstract:
  The TRACER instrument (``Transition Radiation Array for Cosmic Energetic
Radiation'') has been developed for direct measurements of the heavier primary
cosmic-ray nuclei at high energies. The instrument had a successful
long-duration balloon flight in Antarctica in 2003. The detector system and
measurement process are described, details of the data analysis are discussed,
and the individual energy spectra of the elements O, Ne, Mg, Si, S, Ar, Ca, and
Fe (nuclear charge Z=8 to 26) are presented. The large geometric factor of
TRACER and the use of a transition radiation detector make it possible to
determine the spectra up to energies in excess of 10$^{14}$ eV per particle. A
power-law fit to the individual energy spectra above 20 GeV per amu exhibits
nearly the same spectral index ($\sim$ 2.65 $\pm$ 0.05) for all elements,
without noticeable dependence on the elemental charge Z.


title:
Continuous Neel to Bloch Transition as Thickness Increases: Statics and
  Dynamics

abstract:
  We analyze the properties of Neel and Bloch domain walls as a function of
film thickness h, for systems where, in addition to exchange, the dipole-dipole
interaction must be included. The Neel to Bloch phase transition is found to be
a second order transition at hc, mediated by a single unstable mode that
corresponds to oscillatory motion of the domain wall center. A uniform
out-of-plane rf-field couples strongly to this critical mode only in the Neel
phase. An analytical Landau theory shows that the critical mode frequency
varies as the square root of (hc - h) just below the transition, as found
numerically.


title: Phenomenology from the Landscape of String Vacua

abstract:
  This article is the author's PhD thesis. After a review of string vacua
obtained through compactification (with and wothout fluxes), it presents and
describes various aspects of the Landscape of string vacua. At first it gives
an introduction and an overview of the statistical study of the set of four
dimensional string vacua, giving the detailed study of one corner of this set
(G2-holonomy compactifications of M-theory). Then it presents the ten
dimensional approach to string vacua, concentrating on the ten dimensional
description of the Type IIA flux vacua. Finally it gives two examples of models
having some interesting and characteristic phenomenological features, and that
belong to two different corners of the Landscape: warped compactifications of
Type IIB String Theory and M-theory compactifications on G2-holonomy manifolds.


title: No Finite Invariant Density for Misiurewicz Exponential Maps

abstract:
  For exponential mappings such that the orbit of the only singular value 0 is
bounded, it is shown that no integrable density invariant under the dynamics
exists on the complex plane.


title: On sign conditions over real multivariate polynomials

abstract:
  We present a new probabilistic algorithm to find a finite set of points
intersecting the closure of each connected component of the realization of
every sign condition over a family of real polynomials defining regular
hypersurfaces that intersect transversally. This enables us to show a
probabilistic procedure to list all feasible sign conditions over the
polynomials. In addition, we extend these results to the case of closed sign
conditions over an arbitrary family of real multivariate polynomials. The
complexity bounds for these procedures improve the known ones.


title: "Light from chaos" in two dimensions

abstract:
  We perform a Monte-Carlo study of the lattice two-dimensional gauged
XY-model. Our results confirm the strong-coupling expansion arguments that for
sufficiently small values of the spin-spin coupling the ``gauge symmetry
breaking" terms decouple and the long-distance physics is that of the unbroken
pure gauge theory. We find no evidence for the existence, conjectured earlier,
of massless states near a critical value of the spin-spin coupling. We comment
on recent remarks in the literature on the use of gauged XY-models in proposed
constructions of chiral lattice gauge theories.


title: Strangeness and threshold of phase changes

abstract:
  We explore entropy and strangeness as signature of QGP for top AGS energy and
the energy scan at SPS. We find that the hadronization dynamics changes between
20 and 30 $A$ GeV projectile energy. The high energy results are consistent
with QGP.