title: Manipulation and Detection of a Trapped Yb+ Ion Hyperfine Qubit

abstract:
  We demonstrate the use of trapped ytterbium ions as quantum bits for quantum
information processing. We implement fast, efficient state preparation and
state detection of the first-order magnetic field-insensitive hyperfine levels
of 171Yb+, with a measured coherence time of 2.5 seconds. The high efficiency
and high fidelity of these operations is accomplished through the stabilization
and frequency modulation of relevant laser sources.


title:
Trojan Horse as an indirect technique in nuclear astrophysics. Resonance
  reactions

abstract:
  The Trojan Horse method is a powerful indirect technique that provides
information to determine astrophysical factors for binary rearrangement
processes $x + A \to b + B$ at astrophysically relevant energies by measuring
the cross section for the Trojan Horse reaction $a + A \to y+ b + B$ in
quasi-free kinematics. We present the theory of the Trojan Horse method for
resonant binary subreactions based on the half-off-energy-shell R matrix
approach which takes into account the off-energy-shell effects and initial and
final state interactions.


title: Exit paths and constructible stacks

abstract:
  For a Whitney stratification S of a space X (or more generally a topological
stratification in the sense of Goresky and MacPherson) we introduce the notion
of an S-constructible stack of categories on X. The motivating example is the
stack of S-constructible perverse sheaves. We introduce a 2-category $EP_{\leq
2}(X,S)$, called the exit-path 2-category, which is a natural stratified
version of the fundamental 2-groupoid. Our main result is that the 2-category
of S-constructible stacks on X is equivalent to the 2-category of 2-functors
from $EP_{\leq 2}(X,S)$ to the 2-category of small categories.


title:
Network synchronizability analysis: the theory of subgraphs and
  complementary graphs

abstract:
  In this paper, subgraphs and complementary graphs are used to analyze the
network synchronizability. Some sharp and attainable bounds are provided for
the eigenratio of the network structural matrix, which characterizes the
network synchronizability, especially when the network's corresponding graph
has cycles, chains, bipartite graphs or product graphs as its subgraphs.


title:
Decelerating Growth of Vertically Aligned Carbon Nanotube Arrays:
  Kinetic Controlled or Diffusion Controlled?

abstract:
  Feedstock and byproduct diffusion in the root growth of aligned CNT arrays
was discussed in this work. A non-dimensional modulus was proposed to
differentiate catalyst-decay controlled growth deceleration from diffusion
controlled one. It was found that aligned MWNT arrays are usually free of
feedstock diffusion while SWNT arrays are usually facing strong diffusion
limit. The present method can also be utilized to predict the maximum length
that CNT forest can grow in certain CVD process.


title:
Constraints on $f(R_{ijkl}R^{ijkl})$ gravity: An evidence against the
  covariant resolution of the Pioneer anomaly

abstract:
  We consider corrections in the form of $\Delta L(R_{ijkl}R^{ijkl})$ to the
Einstein-Hilbert Lagrangian. Then we compute the corrections to the
Schwarszchild geometry due to the inclusion of this general term to the
Lagrangian. We show that $\Delta L_3=\alpha_{{1/3}}(R_{ijkl}R^{ijkl})^{{1/3}}$
gives rise to a constant anomalous acceleration for objects orbiting the Sun
onward the Sun. This leads to the conclusion that $\alpha_{{1/3}}=(13.91\pm
2.11) \times 10^{-26}(\frac{1}{\text{meters}})^{{2/3}}$ would have covariantly
resolved the Pioneer anomaly if this value of $\alpha_{{1/3}}$ had not
contradicted other observations.
  We notice that the experimental bounds on $\Delta L_3$ grows stronger in case
we examine the deformation of the space-time geometry around objects lighter
than the Sun. We therefore use the high precision measurements around the Earth
(LAGEOS and LLR) and obtain a very strong constraint on the corrections in the
form of $\Delta L(R_{ijkl}R^{ijkl})$ and in particular $\Delta
L=\alpha_n(R_{ijkl}R^{ijkl})^n$. This bound requires
$\alpha_{{1/3}}\leq6.12\times 10^{-29}(\frac{1}{\text{meters}})^{{2/3}}$.
Therefore it refutes the covariant resolution of the Pioneer anomaly.


title: Bose-Einstein condensation of magnons in superfluid 3He

abstract:
  The possibility of Bose-Einstein condensation of excitations has been
discussed for a long time. The phenomenon of the phase-coherent precession of
magnetization in superfluid 3He and the related effects of spin superfluidity
are based on the true Bose-Einstein condensation of magnons. Several different
states of coherent precession has been observed in 3He-B: homogeneously
precessing domain (HPD); persistent signal formed by Q-balls at very low
temperatures; coherent precession with fractional magnetization; and two new
modes of the coherent precession in compressed aerogel. In compressed aerogel
the coherent precession has been also found in 3He-A. Here we demonstrate that
all these cases are examples of a Bose-Einstein condensation of magnons, with
the magnon interaction term in the Gross-Pitaevskii equation being provided by
different types of spin-orbit coupling in the background of the coherent
precession.


title: Shortnote on local hidden Grassmann variables vs. quantum correlations

abstract:
  Grassmannian local hidden variables are shown to generate all possible
quantum correlations in a bipartite quantum system. Grassmann representation of
fermions, common in field theory, opens a related perspective. Although
Grassmann hidden variables can not challange Bell's locality theorem, they can
become an interesting mathematical tool to investigate entanglement.


title: Sisyphus cooling and amplification by a superconducting qubit

abstract:
  Laser cooling of the atomic motion paved the way for remarkable achievements
in the fields of quantum optics and atomic physics, including Bose-Einstein
condensation and the trapping of atoms in optical lattices. More recently
superconducting qubits were shown to act as artificial two-level atoms,
displaying Rabi oscillations, Ramsey fringes, and further quantum effects.
Coupling such qubits to resonators brought the superconducting circuits into
the realm of quantum electrodynamics (circuit QED). It opened the perspective
to use superconducting qubits as micro-coolers or to create a population
inversion in the qubit to induce lasing behavior of the resonator. Furthering
these analogies between quantum optical and superconducting systems we
demonstrate here Sisyphus cooling of a low frequency LC oscillator coupled to a
near-resonantly driven superconducting qubit. In the quantum optics setup the
mechanical degrees of freedom of an atom are cooled by laser driving the atom's
electronic degrees of freedom. Here the roles of the two degrees of freedom are
played by the LC circuit and the qubit's levels, respectively. We also
demonstrate the counterpart of the Sisyphus cooling, namely Sisyphus
amplification. Parallel to the experimental demonstration we analyze the system
theoretically and find quantitative agreement, which supports the
interpretation and allows us to estimate system parameters.


title: On the Planetary acceleration and the Rotation of the Earth

abstract:
  We have developed a model for the Earth rotation that gives a good account
(data) of the Earth astronomical parameters. These data can be compared with
the ones obtained using space-base telescopes. The expansion of the universe
has an impact on the rotation of planets, and in particular, the Earth. The
expansion of the universe causes an acceleration that is exhibited by all
planets.


title:
Nonmaximally entangled states can be better for multiple linear optical
  teleportation

abstract:
  We investigate multiple linear optical teleportation in the
Knill-Laflamme-Milburn scheme with both maximally and nonmaximally entangled
states. We show that if the qubit is teleported several times via nonmaximally
entangled state then the errors introduced in the previous teleportations can
be corrected by the errors introduced in the following teleportations. This
effect is so strong that it leads to another interesting phenomenon, i.e., the
total probability of successful multiple linear optical teleportation is higher
for nonmaximally entangled states than maximally entangled states.


title:
Meta-stable Vacuum in Spontaneously Broken N=2 Supersymmetric Gauge
  Theory

abstract:
  We consider an N=2 supersymmetric SU(2) \times U(1) gauge theory with N_f=2
massless flavors and a Fayet-Iliopoulos (FI) term. In the presence of the FI
term, supersymmetry is spontaneously broken at tree level (on the Coulomb
branch), leaving a pseudo-flat direction in the classical potential. This
vacuum degeneracy is removed once quantum corrections are taken into account.
Due to the SU(2) gauge dynamics, the effective potential exhibits a local
minimum at the dyon point, where not only supersymmetry but also U(1)_R
symmetry is broken, while a supersymmetric vacuum would be realized toward
infinity with the runaway behavior of the potential. This local minimum is
found to be parametrically long-lived. Interestingly, from a phenomenological
point of view, in this meta-stable vacuum the massive hypermultiplets inherent
in the theory play the role of the messenger fields in the gauge mediation
scenario, when the Standard Model gauge group is embedded into their flavor
symmetry.


title: Notes on quantization of symplectic vector spaces over finite fields

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


title:
Spectral and Dynamical Properties of Certain Random Jacobi Matrices with
  Growing Parameters

abstract:
  In this paper, a family of random Jacobi matrices, with off-diagonal terms
that exhibit power-law growth, is studied. Since the growth of the randomness
is slower than that of these terms, it is possible to use methods applied in
the study of Schr\"odinger operators with random decaying potentials. A
particular result of the analysis is the existence of operators with
arbitrarily fast transport whose spectral measure is zero dimensional. The
results are applied to the infinite Gaussian $\beta$ Ensembles and their
spectral properties are analyzed.


title: Unparticle Physics and A_{FB}^b on the Z pole

abstract:
  An attempt has been made to address the 3\sigma anomaly of the
forward-backward asymmetry of b quark in LEP data via an unparticle sector. For
most part of the parameter space except certain particular regions, the anomaly
could not be explained away plausibly, when constraints from other LEP
observables are taken into account.


title: Comments on operators with large spin

abstract:
  We consider high spin operators. We give a general argument for the
logarithmic scaling of their anomalous dimensions which is based on the
symmetries of the problem. By an analytic continuation we can also see the
origin of the double logarithmic divergence in the Sudakov factor. We show that
the cusp anomalous dimension is the energy density for a flux configuration of
the gauge theory on $AdS_3 \times S^1$. We then focus on operators in ${\cal
N}=4$ super Yang Mills which carry large spin and SO(6) charge and show that in
a particular limit their properties are described in terms of a bosonic O(6)
sigma model. This can be used to make certain all loop computations in the
string theory.


title: Structures of the reduced niobium oxides Nb12O29 and Nb22O54

abstract:
  The crystal structure of Nb22O54 is reported for the first time, and the
structure of orthorhombic Nb12O29 is reexamined, resolving previous
ambiguities. Single crystal x-ray and electron diffraction were employed. These
compounds were found to crystallize in the space groups P2/m (a = 15.7491(2) A,
b = 3.8236(3) A, c = 17.8521(2) A, beta = 102.029(3)) and Cmcm (a = 3.8320(2)
A, b = 20.7400(9) A, c = 28.8901(13) A) respectively and share a common
structural unit, a 4x3 block of corner sharing NbO6 octahedra. Despite
different constraints imposed by symmetry these blocks are very similar in both
compounds. Within a block, it is found that the niobium atoms are not located
in the centers of the oxygen octahedra, but rather are displaced inward toward
the center of the block forming an apparent antiferroelectric state. Bond
valence sums and bond lengths do not show the presence of charge ordering,
suggesting that all 4d electrons are delocalized in these compounds at the
temperature studied, T = 200 K.


title: Emission Lines in X-ray Spectra of Clusters of Galaxies

abstract:
  Emission lines in X-ray spectra of clusters of galaxies reveal the presence
of heavy elements in the diffuse hot plasma (the Intra Cluster Medium, or ICM)
in virial equilibrium in the dark matter potential well. The relatively simple
physical state of the ICM allows us to estimate, with good accuracy, its
thermodynamical properties and chemical abundances. These measures put strong
constraints on the interaction processes between the galaxies and the
surrounding medium, and have significant impact on models of galaxy formation
as well. This field is rapidly evolving thanks to the X-ray satellites Chandra
and XMM-Newton. Among the most relevant progresses in the last years, we
briefly discuss the nature of cool cores and the measure of the Iron abundance
in high redshift clusters. Future X-ray missions with bolometers promise to
provide a substantial step forward to a more comprehensive understanding of the
complex physics of the ICM.


title: Vector field theories in cosmology

abstract:
  Recently proposed theories based on the cosmic presence of a vectorial field
are compared and contrasted. In particular the so called Einstein aether theory
is discussed in parallel with a recent proposal of a strained space-time theory
(Cosmic Defect theory). We show that the latter fits reasonably well the cosmic
observed data with only one, or at most two, adjustable parameters, whilst
other vector theories use much more. The Newtonian limits are also compared.
Finally we show that the CD theory may be considered as a special case of the
aether theories, corresponding to a more compact and consistent paradigm.


title: Mosaic spin models with topological order

abstract:
  We study a class of two-dimensional spin models with the Kitaev-type
couplings in mosaic structure lattices to implement topological orders. We show
that they are exactly solvable by reducing them to some free Majorana fermion
models with gauge symmetries. The typical case with a 4-8-8 close packing is
investigated in detail to display the quantum phases with Abelian and
non-Abelian anyons. Its topological properties characterized by Chern numbers
are revealed through the edge modes of its spectrum.


title: Observables IV: The presheaf perspective

abstract:
  In this fourth of our series of papers on observables we show that one can
associate to each von Neumann algebra R a pair of isomorphic presheaves, the
upper presheaf O^{+}_{R} and the lower presheaf O^{-}_{R}, on the category of
abelian von Neumann subalgebras of R. Each $A \in R_{sa}$ induces a global
section of O^{+}_{R} and of O^{-}_{R} respectively. We call them \emph
{contextual observables}. But we show that, in general, not every global
section of these presheaves arises in this way. Moreover, we discuss states of
a von Neumann algebra in the presheaf context.


title: Kinetic Theory of Response Functions for the Hard Sphere Granular Fluid

abstract:
  The response functions for small spatial perturbations of a homogeneous
granular fluid have been described recently. In appropriate dimensionless
variables, they have the form of stationary state time correlation functions.
Here, these functions are expressed in terms of reduced single particle
functions that are expected to obey a linear kinetic equation. The functional
assumption required for such a kinetic equation, and a Markov approximation for
its implementation are discussed. If, in addition, static velocity correlations
are neglected, a granular fluid version of the linearized Enskog kinetic theory
is obtained. The derivation makes no a priori limitation on the density, space
and time scale, nor degree of inelasticity. As an illustration, recently
derived Helfand and Green-Kubo expressions for the Navier-Stokes order
transport coefficients are evaluated with this kinetic theory. The results are
in agreement with those obtained from the Chapman-Enskog solution to the
nonlinear Enskog kinetic equation.


title:
Superposition Formulas for Darboux Integrable Exterior Differential
  Systems

abstract:
  In this paper we present a far-reaching generalization of E. Vessiot's
analysis of the Darboux integrable partial differential equations in one
dependent and two independent variables. Our approach provides new insights
into this classical method, uncovers the fundamental geometric invariants of
Darboux integrable systems, and provides for systematic, algorithmic
integration of such systems. This work is formulated within the general
framework of Pfaffian exterior differential systems and, as such, has
applications well beyond those currently found in the literature. In
particular, our integration method is applicable to systems of hyperbolic PDE
such as the Toda lattice equations, 2 dimensional wave maps and systems of
overdetermined PDE.


title:
$\Lambda$-CDM Universe: A Phenomenological Approach With Many
  Possibilities

abstract:
  A time-dependent phenomenological model of $\Lambda$, viz. $\dot \Lambda\sim
H^3$ is selected to investigate the $\Lambda$-CDM cosmology. Time-dependent
form of the equation of state parameter $\omega$ is derived and it has been
possible to obtain the sought for flip of sign of the deceleration parameter q.
Present age of the Universe, calculated for some specific values of the
parameters agrees very well with the observational data.


title: Macroscopic violation of special relativity

abstract:
  Feynman one of the founders of Quantum Electronic Dynamics (QED) introduced
in his diagrams virtual particles as intermediate states of an interaction
process. Such virtual particles are not observable, however, from the
theoretical point of view they represent necessary intermediate states between
observable real states. Such virtual particles were introduced for describing
the interaction process between an electron and a positron and for much more
complicated interaction processes. Other candidates for virtual photons are
evanescent modes known from optics. Evanescent modes have a purely imaginary
wave number, they represent the mathematical analogy of the tunneling solutions
of the Schr\"odinger equation. Evanescent modes are present in the optical
processes of total reflection and in undersized wave guides for instance. The
most prominent example of the occurrence of evanescent modes is frustrated
total internal reflection at double prisms. In 1949 Sommerfeld
\cite{Sommerfeld} pointed out that this optical phenomenon represents the
analogy of quantum mechanical tunneling. The evanescent modes and tunneling
violate the theory of special relativity, obviously, they represent the
exception which proves the special theory of relativity. We demonstrate the
quantum mechanical behavior of evanescent modes \textbf{with digital microwave}
signals at a macroscopic scale of the order of a meter and show that evanescent
modes are well described by virtual photons as predicted by former QED
calculations.


title: Perturbed Beta-Gamma Systems and Complex Geometry

abstract:
  We consider the equations, arising as the conformal invariance conditions of
the perturbed curved beta-gamma system. These equations have the physical
meaning of Einstein equations with a B-field and a dilaton on a hermitian
manifold, where the B-field 2-form is imaginary and proportional to the
canonical form associated with hermitian metric. We show that they decompose
into linear and bilinear equations and lead to the vanishing of the first Chern
class of the manifold where the system is defined. We discuss the relation of
these equations to the generalized Maurer-Cartan structures related to BRST
operator. Finally we describe the relations of the generalized Maurer-Cartan
bilinear operation and the Courant/Dorfman brackets.


title: Persistence and Memory in Patchwork Dynamics for Glassy Models

abstract:
  Slow dynamics in disordered materials prohibits direct simulation of their
rich nonequilibrium behavior at large scales. "Patchwork dynamics" is
introduced to mimic relaxation over a very broad range of time scales by
equilibrating or optimizing directly on successive length scales. This dynamics
is used to study coarsening and to replicate memory effects for spin glasses
and random ferromagnets. It is also used to find, with high confidence, exact
ground states in large or toroidal samples.


title:
Parametric excitation and chaos through dust-charge fluctuation in a
  dusty plasma

abstract:
  We consider a van der Pol-Mathieu (vdPM) equation with parametric forcing,
which arises in a simplified model of dusty plasma with dust-charge
fluctuation. We make a detailed numerical investigation and show that the
system can be driven to chaos either through a period doubling cascade or
though a subcritical pitchfork bifurcation over an wide range of parameter
space. We also discuss the frequency entrainment or frequency-locked phase of
the dust-charge fluctuation dynamics and show that the system exhibits 2:1
parametric resonance away from the chaotic regime.


title:
Dynamics of semi-flexible polymer solutions in the highly entangled
  regime

abstract:
  We present experimental evidence that the effective medium approximation
(EMA), developed by D.C. Morse [Phys. Rev. E {\bf 63}, 031502, (2001)],
provides the correct scaling law of the macroscopic plateau modulus
$G^{0}\propto\rho^{4/3}L^{-1/3}_{p}$ (where $\rho$ is the contour length per
unit volume and $L_{p}$ is the persistence length) of semi-flexible polymer
solutions, in the highly entangled concentration regime. Competing theories,
including a self-consistent binary collision approximation (BCA), have instead
predicted $G^{0}\propto\rho^{7/5}L^{-1/5}_{p}$. We have tested both the EMA and
BCA scaling predictions using actin filament (F-actin) solutions which permit
experimental control of $L_p$ independently of other parameters. A combination
of passive video particle tracking microrheology and dynamic light scattering
yields independent measurements of the elastic modulus $G$ and $L_{p}$
respectively. Thus we can distinguish between the two proposed laws, in
contrast to previous experimental studies, which focus on the (less
discriminating) concentration functionality of $G$.


title: Spectral analysis of transfer operators associated to Farey fractions

abstract:
  The spectrum of a one-parameter family of signed transfer operators
associated to the Farey map is studied in detail. We show that when acting on a
suitable Hilbert space of analytic functions they are self-adjoint and exhibit
absolutely continuous spectrum and no non-zero point spectrum. Polynomial
eigenfunctions when the parameter is a negative half-integer are also
discussed.


title:
Universal thermal and electrical transport near the superconductor-metal
  quantum phase transition in nanowires

abstract:
  We describe the thermal and electrical conductivities of quasi-one
dimensional wires, across a quantum phase transition from a superconductor to a
metal induced by pairbreaking perturbations. Fluctuation corrections to BCS
theory motivate a field theory for quantum criticality. We describe deviations
in the Wiedemann-Franz ratio from the Lorenz number, which can act as sensitive
tests of the theory. We also describe the crossovers out of the quantum
critical region into the metallic and superconducting phases.


title: Stellar Relaxation Processes Near the Galactic Massive Black Hole

abstract:
  The massive black hole (MBH) in the Galactic Center and the stars around it
form a unique stellar dynamics laboratory for studying how relaxation processes
affect the distribution of stars and compact remnants and lead to close
interactions between them and the MBH. Recent theoretical studies suggest that
processes beyond "minimal" two-body relaxation may operate and even dominate
relaxation and its consequences in the Galactic Center. I describe loss-cone
refilling by massive perturbers, strong mass segregation and resonant
relaxation; review observational evidence that these processes play a role in
the Galactic Center; and discuss some cosmic implications for the rates of
gravitational wave emission events from compact remnants inspiraling into MBHs,
and the coalescence timescales of binary MBHs.


title: The automorphism group of the tetrablock

abstract:
  The tetrablock is a domain in 3-dimensional complex space that meets
3-dimensional Euclidean space in a regular tetrahedron. It is shown to be
inhomogeneous and its automorphism group is determined. A type of Schwarz lemma
for the tetrablock is proved. The action of the automorphism group is described
in terms of a certain natural foliation of the tetrablock by complex geodesic
discs.


title:
Staggered repulsion of transmission eigenvalues in symmetric open
  mesoscopic systems

abstract:
  Quantum systems with discrete symmetries can usually be desymmetrized, but
this strategy fails when considering transport in open systems with a symmetry
that maps different openings onto each other. We investigate the joint
probability density of transmission eigenvalues for such systems in
random-matrix theory. In the orthogonal symmetry class we show that the
eigenvalue statistics manifests level repulsion between only every second
transmission eigenvalue. This finds its natural statistical interpretation as a
staggeredsuperposition of two eigenvalue sequences. For a large number of
channels, the statistics for a system with a lead-transposing symmetry
approaches that of a superposition of two uncorrelated sets of eigenvalues as
in systems with a lead-preserving symmetry (which can be desymmetrized). These
predictions are confirmed by numerical computations of the
transmission-eigenvalue spacing distribution for quantum billiards and for the
open kicked rotator.


title: Asymptotics for rank partition functions

abstract:
  In this paper, we obtain asymptotic formulas for an infinite class of rank
generating functions. As an application, we solve a conjecture of Andrews and
Lewis on inequalities between certain ranks.


title: Dyson's Rank, overpartitions, and weak Maass forms

abstract:
  In a series of papers the first author and Ono connected the rank, a
partition statistic introduced by Dyson, to weak Maass forms, a new class of
functions which are related to modular forms. Naturally it is of wide interest
to find other explicit examples of Maass forms. Here we construct a new
infinite family of such forms, arising from overpartitions. As applications we
obtain combinatorial decompositions of Ramanujan-type congruences for
overpartitions as well as the modularity of rank differences in certain
arithmetic progressions.


title:
Stretch fast dynamo mechanism via conformal mapping in Riemannian
  manifolds

abstract:
  Two new analytical solutions of self-induction equation, in Riemannian
manifolds are presented. The first represents a twisted magnetic flux tube or
flux rope in plasma astrophysics, which shows that the depending on rotation of
the flow the poloidal field is amplified from toroidal field which represents a
dynamo. The value of the amplification depends on the Frenet torsion of the
magnetic axis of the tube. Actually this result illustrates the Zeldovich
stretch, twist and fold (STF) method to generate dynamos from straight and
untwisted ropes. Motivated by the fact that this problem was treated using a
Riemannian geometry of twisted magnetic flux ropes recently developed (Phys
Plasmas (2006)), we investigated a second dynamo solution which is conformally
related to the Arnold kinematic fast dynamo. In this solution it is shown that
the conformal effect on the fast dynamo metric only enhances the Zeldovich
stretch, and therefore a new dynamo solution is obtained. When a conformal
mapping is performed in Arnold fast dynamo line element a uniform stretch is
obtained in the original line element.


title:
Reconstruction of Protein-Protein Interaction Pathways by Mining
  Subject-Verb-Objects Intermediates

abstract:
  The exponential increase in publication rate of new articles is limiting
access of researchers to relevant literature. This has prompted the use of text
mining tools to extract key biological information. Previous studies have
reported extensive modification of existing generic text processors to process
biological text. However, this requirement for modification had not been
examined. In this study, we have constructed Muscorian, using MontyLingua, a
generic text processor. It uses a two-layered generalization-specialization
paradigm previously proposed where text was generically processed to a suitable
intermediate format before domain-specific data extraction techniques are
applied at the specialization layer. Evaluation using a corpus and experts
indicated 86-90% precision and approximately 30% recall in extracting
protein-protein interactions, which was comparable to previous studies using
either specialized biological text processing tools or modified existing tools.
Our study had also demonstrated the flexibility of the two-layered
generalization-specialization paradigm by using the same generalization layer
for two specialized information extraction tasks.


title:
Direct observation of quantized interlayer vortex flow and vortex
  pinning distribution in high-Tc La_(1.87)Sr_(0.13)CuO_4 single crystals

abstract:
  A scanning superconducting quantum interference device (SQUID) microscope
(SSM) is used to study the magnetic imaging of dynamic motion of quantized
interlayer vortices induced by the Lorentz force in anisotropic high-Tc
La_(1.87)Sr_(0.13)CuO_4 single crystals. It is found that 3 modes of flux
motion switch depending on the transport current. By increasing the current a
transition from the creep-like behavior of vortices to a steady flow of
vortices was observed. Even higher current induced a continuous expansion of
vortex-flow area indicating an inhomogeneous distribution of various pinning
centers.


title:
Thermal Timescale Mass Transfer Rates in Intermediate-Mass X-ray
  Binaries

abstract:
  Thermal timescale mass transfer generally occurs in close binaries where the
donor star is more massive than the accreting star. The mass transfer rates are
usually estimated in terms of the Kelvin-Helmholtz timescale of the donor star.
But recent investigations indicate that this method may overestimate the real
mass transfer rates in accreting white dwarf or neutron star binary systems. We
have systematically investigated the thermal-timescale mass transfer processes
in intermediate-mass X-ray binaries, by calculating binary evolution sequences
with various initial donor masses and orbital periods. From the calculated
results we find that on average the mass transfer rates are lower than
traditional estimates by a factor of $\sim 4$.


title: Regularity of some class of nonlinear transformations

abstract:
  In this paper we consider quadratic stochastic operators designed on finite
Abelian groups. It is proved that such operators have the property of
regularity.


title:
Calculation of absolute free energy of binding for theophylline and its
  analogs to RNA aptamer using nonequilibrium work values

abstract:
  The massively parallel computation of absolute binding free energy with a
well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida,
M. Ito, G. Jayachandran, C. D. Snow, M. R. Shirts, E. J. Sorin, and V. S.
Pande, J. Chem. Phys. ${\bf 123}$, 084108 (2005)]. As an application, we
perform the binding affinity calculations of six theophylline-related ligands
with RNA aptamer. Basically, our method is applicable when using many compute
nodes to accelerate simulations, thus a parallel computing system is also
developed. To further reduce the computational cost, the adequate non-uniform
intervals of coupling constant $\lambda$, connecting two equilibrium states,
namely bound and unbound, are determined. The absolute binding energies $\Delta
G$ thus obtained have effective linear relation between the computed and
experimental values. If the results of two other different methods are
compared, thermodynamic integration (TI) and molecular mechanics
Poisson-Boltzmann surface area (MM-PBSA) by the paper of Gouda $et al$ [H.
Gouda, I. D. Kuntz, D. A. Case, and P. A. Kollman, Biopolymers ${\bf 68}$, 16
(2003)], the predictive accuracy of the relative values $\Delta\Delta G$ is
almost comparable to that of TI: the correlation coefficients (R) obtained are
0.99 (this work), 0.97 (TI), and 0.78 (MM-PBSA). On absolute binding energies
meanwhile, a constant energy shift of $\sim$ -7 kcal/mol against the
experimental values is evident. To solve this problem, several presumable
reasons are investigated.


title:
The Spitzer 24-micron Photometric Light Curve of the Eclipsing M-dwarf
  Binary GU Bootis

abstract:
  We present a carefully controlled set of Spitzer 24 \micron MIPS time series
observations of the low mass eclipsing binary star GU Bo\"otis (GU Boo). Our
data cover three secondary eclipses of the system: two consecutive events and
an additional eclipse six weeks later. The study's main purpose is the long
wavelength characterization of GU Boo's light curve, independent of limb
darkening and less sensitive to surface features such as spots. Its analysis
allows for independent verification of the results of optical studies of GU
Boo. Our mid-infrared results show good agreement with previously obtained
system parameters. In addition, the analysis of light curves of other objects
in the field of view serves to characterize the photometric stability and
repeatability of {\it Spitzer's} MIPS-24 at flux densities between
approximately 300--2,000$\mu$Jy. We find that the light curve root mean square
about the median level falls into the 1--4% range for flux densities higher
than 1 mJy.


title:
Spectral decomposition approach to macroscopic parameters of
  Fokker-Planck flows: Part 2

abstract:
  In this paper we proceed with investigation of connections between Fokker -
Planck equation and continuum mechanics. We base upon expressions from our work
[2], based upon the spectral decomposition of Fokker - Planck equation
solution. In this decomposition we preserve only terms with the smallest
degrees of damping. We find, that macroscopic parameters of Fokker-Planck
flows, obtained in this way, satisfy the set of conservation laws of classic
hydrodynamics. The expression for stresses (30) contains additional term - this
term is negligible in big times limit. We proved also, that the velocities
field alone satisfy Burgers equation without mass forces - but with some
additional term. This term is also negligible in big times limit. For the zero
degree theory, considered in [1], there are no additional terms. But this
theory is valid only for the potential velocities field, fully deductible from
density - the potential is proportional to density logarithm. In this theory we
can not specify initial conditions for velocities independently from density.
Taking in account of the next degree terms could partly solve this problem, but
result in some loss of exactness.


title: Multi-magnon bound states in the frustrated ferromagnetic 1D chain

abstract:
  We study a one-dimensional Heisenberg chain with competing ferromagnetic
nearest-neighbor and antiferromagnetic next-nearest neighbor interactions in
magnetic field. Starting from the fully polarized high-field state, we
calculate the dispersions of the lowest-lying $n$-magnon excitations and the
saturation field (n=2,3,4). We show that the lowest-lying excitations are
always bound multi-magnon states with a total momentum of $\pi$ except for a
small parameter range. We argue that bose condensation of the bound $n$ magnons
leads to novel Tomonaga-Luttinger liquids with multi-polar correlations;
nematic and triatic ordered liquids correspond to n=2 and n=3.


title: Quasi Exactly Solvable Difference Equations

abstract:
  Several explicit examples of quasi exactly solvable `discrete' quantum
mechanical Hamiltonians are derived by deforming the well-known exactly
solvable Hamiltonians of one degree of freedom. These are difference analogues
of the well-known quasi exactly solvable systems, the harmonic oscillator
(with/without the centrifugal potential) deformed by a sextic potential and the
1/sin^2x potential deformed by a cos2x potential. They have a finite number of
exactly calculable eigenvalues and eigenfunctions.


title: Detection of subthreshold pulses in neurons with channel noise

abstract:
  Neurons are subject to various kinds of noise. In addition to synaptic noise,
the stochastic opening and closing of ion channels represents an intrinsic
source of noise that affects the signal processing properties of the neuron. In
this paper, we studied the response of a stochastic Hodgkin-Huxley neuron to
transient input subthreshold pulses. It was found that the average response
time decreases but variance increases as the amplitude of channel noise
increases. In the case of single pulse detection, we show that channel noise
enables one neuron to detect the subthreshold signals and an optimal membrane
area (or channel noise intensity) exists for a single neuron to achieve optimal
performance. However, the detection ability of a single neuron is limited by
large errors. Here, we test a simple neuronal network that can enhance the
pulse detecting abilities of neurons and find dozens of neurons can perfectly
detect subthreshold pulses. The phenomenon of intrinsic stochastic resonance is
also found both at the level of single neurons and at the level of networks. At
the network level, the detection ability of networks can be optimized for the
number of neurons comprising the network.


title: On Colorings of Graph Powers

abstract:
  In this paper, some results concerning the colorings of graph powers are
presented. The notion of helical graphs is introduced. We show that such graphs
are hom-universal with respect to high odd-girth graphs whose $(2t+1)$st power
is bounded by a Kneser graph. Also, we consider the problem of existence of
homomorphism to odd cycles. We prove that such homomorphism to a $(2k+1)$-cycle
exists if and only if the chromatic number of the $(2k+1)$st power of $S_2(G)$
is less than or equal to 3, where $S_2(G)$ is the 2-subdivision of $G$. We also
consider Ne\v{s}et\v{r}il's Pentagon problem. This problem is about the
existence of high girth cubic graphs which are not homomorphic to the cycle of
size five. Several problems which are closely related to Ne\v{s}et\v{r}il's
problem are introduced and their relations are presented.


title: Creation of ballot sequences in a periodic cellular automaton

abstract:
  Motivated by an attempt to develop a method for solving initial value
problems in a class of one dimensional periodic cellular automata (CA)
associated with crystal bases and soliton equations, we consider a
generalization of a simple proposition in elementary mathematics. The original
proposition says that any sequence of letters 1 and 2, having no less 1's than
2's, can be changed into a ballot sequence via cyclic shifts only. We
generalize it to treat sequences of cells of common capacity s > 1, each of
them containing consecutive 2's (left) and 1's (right), and show that these
sequences can be changed into a ballot sequence via two manipulations, cyclic
and "quasi-cyclic" shifts. The latter is a new CA rule and we find that various
kink-like structures are traveling along the system like particles under the
time evolution of this rule.


title:
Noise Suppression for Micromechanical Resonator via Intrinsic Dynamic
  Feedback

abstract:
  We study a dynamic mechanism to passively suppress the thermal noise of a
micromechanical resonator through an intrinsic self-feedback that is genuinely
non-Markovian. We use two coupled resonators, one as the target resonator and
the other as an ancillary resonator, to illustrate the mechanism and its noise
reduction effect. The intrinsic feedback is realized through the dynamics of
coupling between the two resonators: the motions of the target resonator and
the ancillary resonator mutually influence each other in a cyclic fashion.
Specifically, the states that the target resonator has attained earlier will
affect the state it attains later due to the presence of the ancillary
resonator. We show that the feedback mechanism will bring forth the effect of
noise suppression in the spectrum of displacement, but not in the spectrum of
momentum.


title: Hidden scale in quantum mechanics

abstract:
  We show that the intriguing localization of a free particle wave-packet is
possible due to a hidden scale present in the system. Self-adjoint extensions
(SAE) is responsible for introducing this scale in quantum mechanical models
through the nontrivial boundary conditions. We discuss a couple of classically
scale invariant free particle systems to illustrate the issue. In this context
it has been shown that a free quantum particle moving on a full line may have
localized wave-packet around the origin. As a generalization, it has also been
shown that particles moving on a portion of a plane or on a portion of a three
dimensional space can have unusual localized wave-packet.


title: Horizons of Coalescing Black Holes on Eguchi-Hanson Space

abstract:
  Using the numerical method, we study dynamics of coalescing black holes on
the Eguchi-Hanson base space. Effects of a difference in spacetime topology on
the black hole dynamics is discussed. We analyze appearance and disappearance
process of marginal surfaces. In our calculation, the area of a coverall black
hole horizon at the creation time in the coalescing black holes solutions on
Eguchi-Hanson space is larger than that in the five-dimensional Kastor-Traschen
solutions. This fact suggests that the black hole production on the
Eguchi-Hanson space is easier than that on the flat space.


title:
Quantum cryptography with finite resources: unconditional security bound
  for discrete-variable protocols with one-way post-processing

abstract:
  We derive a bound for the security of QKD with finite resources under one-way
post-processing, based on a definition of security that is composable and has
an operational meaning. While our proof relies on the assumption of collective
attacks, unconditional security follows immediately for standard protocols like
Bennett-Brassard 1984 and six-states. For single-qubit implementations of such
protocols, we find that the secret key rate becomes positive when at least
N\sim 10^5 signals are exchanged and processed. For any other discrete-variable
protocol, unconditional security can be obtained using the exponential de
Finetti theorem, but the additional overhead leads to very pessimistic
estimates.


title: Evidence of two distinct charge carriers in underdoped high Tc cuprates

abstract:
  We present results on heavily underdoped Y_1-xCa_xBa_2Cu_3O_6+y which provide
the evidence that the doping mechanism (cation substitution or oxygen loading)
directly determines whether the corresponding injected mobile holes contribute
to superconductivity or only to the normal metallic properties. We argue that
this hole tagging calls for a subtler description of the correlated bands than
the usual one. We also map in great detail the underdoped superconducting phase
diagram T_c vs. hole doping which shows that the number of mobile holes is not
the critical parameter for the superconductivity.


title: Convergence of adaptive mixtures of importance sampling schemes

abstract:
  In the design of efficient simulation algorithms, one is often beset with a
poor choice of proposal distributions. Although the performance of a given
simulation kernel can clarify a posteriori how adequate this kernel is for the
problem at hand, a permanent on-line modification of kernels causes concerns
about the validity of the resulting algorithm. While the issue is most often
intractable for MCMC algorithms, the equivalent version for importance sampling
algorithms can be validated quite precisely. We derive sufficient convergence
conditions for adaptive mixtures of population Monte Carlo algorithms and show
that Rao--Blackwellized versions asymptotically achieve an optimum in terms of
a Kullback divergence criterion, while more rudimentary versions do not benefit
from repeated updating.


title:
Virtual Environments for Training: From Individual Learning to
  Collaboration with Humanoids

abstract:
  The next generation of virtual environments for training is oriented towards
collaborative aspects. Therefore, we have decided to enhance our platform for
virtual training environments, adding collaboration opportunities and
integrating humanoids. In this paper we put forward a model of humanoid that
suits both virtual humans and representations of real users, according to
collaborative training activities. We suggest adaptations to the scenario model
of our platform making it possible to write collaborative procedures. We
introduce a mechanism of action selection made up of a global repartition and
an individual choice. These models are currently being integrated and validated
in GVT, a virtual training tool for maintenance of military equipments,
developed in collaboration with the French company NEXTER-Group.


title: Edit and verify

abstract:
  Automated theorem provers are used in extended static checking, where they
are the performance bottleneck. Extended static checkers are run typically
after incremental changes to the code. We propose to exploit this usage pattern
to improve performance. We present two approaches of how to do so and a full
solution.


title: A Strict Inequality for a Minimal Degree of a Direct Product

abstract:
  The minimal faithful permutation degree of a finite group G is the least
non-negative integer n such that G embeds in the symmetric group Sym(n). Work
of Johnson and Wright established conditions for when the minimal degree of a
direct product equals the sum of the minimal degrees for two finite groups.
Wright asked whether this is true for all finite groups. A counter- example of
degree 15 was provided by the referee and was added as an addendum in a paper
of Wright. Here we provide a counter-example of degree 12.


title:
Step-up simultaneous tests for identifying active effects in orthogonal
  saturated designs

abstract:
  A sequence of null hypotheses regarding the number of negligible effects
(zero effects) in orthogonal saturated designs is formulated. Two step-up
simultaneous testing procedures are proposed to identify active effects
(nonzero effects) under the commonly used assumption of effect sparsity. It is
shown that each procedure controls the experimentwise error rate at a given
$\alpha$ level in the strong sense.


title: Multi-Particle Quasi Exactly Solvable Difference Equations

abstract:
  Several explicit examples of multi-particle quasi exactly solvable `discrete'
quantum mechanical Hamiltonians are derived by deforming the well-known exactly
solvable multi-particle Hamiltonians, the Ruijsenaars-Schneider-van Diejen
systems. These are difference analogues of the quasi exactly solvable
multi-particle systems, the quantum Inozemtsev systems obtained by deforming
the well-known exactly solvable Calogero-Sutherland systems. They have a finite
number of exactly calculable eigenvalues and eigenfunctions. This paper is a
multi-particle extension of the recent paper by one of the authors on deriving
quasi exactly solvable difference equations of single degree of freedom.


title:
X-ray Scattering Study of the spin-Peierls transition and soft phonon
  behavior in TiOCl

abstract:
  We have studied the S=1/2 quasi-one-dimensional antiferromagnet TiOCl using
single crystal x-ray diffraction and inelastic x-ray scattering techniques. The
Ti ions form staggered spin chains which dimerize below Tc1 = 66 K and have an
incommensurate lattice distortion between Tc1 and Tc2 = 92 K. Based on our
measurements of the intensities, wave vectors, and harmonics of the
incommensurate superlattice peaks, we construct a model for the incommensurate
modulation. The results are in good agreement with a soliton lattice model,
though some quantitative discrepancies exist near Tc2. The behavior of the
phonons has been studied using inelastic x-ray scattering with ~2 meV energy
resolution. For the first time, a zone boundary phonon which softens at the
spin-Peierls temperature Tsp has been observed. Our results show reasonably
good quantitative agreement with the Cross-Fisher theory for the phonon
dynamics at wave vectors near the zone boundary and temperatures near Tsp.
However, not all aspects of the data can be described, such as the strong
overdamping of the soft mode above Tsp. Overall, our results show that TiOCl is
a good realization of a spin-Peierls system, where the phonon softening allows
us to identify the transition temperature as Tsp=Tc2=92 K


title:
Continuous-Time Quantum Monte Carlo Method for the Coqblin-Schrieffer
  Model

abstract:
  An impurity solver based on a continuous-time quantum Monte Carlo method is
developed for the Coqblin-Schrieffer model. The Monte Carlo simulation does not
encounter a sign problem for antiferromagnetic interactions, and accurately
reproduces the Kondo effect. Our algorithm can deal with an arbitrary number N
of local degrees of freedom, becomes more efficient for larger values of N, and
is hence suitable for models with orbital degeneracy. The dynamical
susceptibility and the impurity t-matrix are derived with the aid of the Pad\'e
approximation for various values of N, and good agreement is found with other
methods and available exact results. We point out that the Korringa-Shiba
relation needs correction for a finite value of the exchange interaction.


title: Hopf Bifurcation in a Model for Biological Control

abstract:
  In this paper we study the Lyapunov stability and Hopf bifurcation in a
biological system which models the biological control of parasites of orange
plantations.


title: Quantum mechanics as a spontaneously broken gauge theory on a U(1) gerbe

abstract:
  Any quantum-mechanical system possesses a U(1) gerbe naturally defined on
configuration space. Acting on Feynman's kernel exp(iS/h), this U(1) symmetry
allows one to arbitrarily pick the origin for the classical action S, on a
point-by-point basis on configuration space. This is equivalent to the
statement that quantum mechanics is a U(1) gauge theory. Unlike Yang-Mills
theories, however, the geometry of this gauge symmetry is not given by a fibre
bundle, but rather by a gerbe. Since this gauge symmetry is spontaneously
broken, an analogue of the Higgs mechanism must be present. We prove that a
Heisenberg-like noncommutativity for the space coordinates is responsible for
the breaking. This allows to interpret the noncommutativity of space
coordinates as a Higgs mechanism on the quantum-mechanical U(1) gerbe.


title: The Mass Function of omega Centauri down to 0.15 M_s

abstract:
  By means of deep FORS1@VLT and ACS@HST observations of a wide area in the
stellar system omega Cen we measured the luminosity function of main sequence
stars down to R=22.6 and I_{F814W}=24.5 . The luminosity functions obtained
have been converted into mass functions and compared with analytical Initial
Mass Functions (IMFs) available in the literature. The mass function obtained,
reaching M~0.15 M_s, can be well reproduced by a broken power-law with indices
alpha=-2.3 for M>0.5 M_s and alpha=-0.8 for M<0.5 M_s. Since the stellar
populations of omega Cen have been proved to be actually unaffected by
dynamical evolution processes, the mass function measured in this stellar
system should represent the best approximation of the IMF of a star cluster.
The comparison with the MF measured in other Galactic globular clusters
suggests that possible primordial differences in the slope of the low-mass end
of their MF could exist.


title: Filtering of Wide Sense Stationary Quantum Stochastic Processes

abstract:
  We introduce a concept of a quantum wide sense stationary process taking
values in a C*-algebra and expected in a sub-algebra. The power spectrum of
such a process is defined, in analogy to classical theory, as a positive
measure on frequency space taking values in the expected algebra. The notion of
linear quantum filters is introduced as some simple examples mentioned.


title: The Newtonian Limit of F(R) gravity

abstract:
  A general analytic procedure is developed to deal with the Newtonian limit of
$f(R)$ gravity. A discussion comparing the Newtonian and the post-Newtonian
limit of these models is proposed in order to point out the differences between
the two approaches. We calculate the post-Newtonian parameters of such theories
without any redefinition of the degrees of freedom, in particular, without
adopting some scalar fields and without any change from Jordan to Einstein
frame. Considering the Taylor expansion of a generic $f(R)$ theory, it is
possible to obtain general solutions in term of the metric coefficients up to
the third order of approximation. In particular, the solution relative to the
$g_{tt}$ component gives a gravitational potential always corrected with
respect to the Newtonian one of the linear theory $f(R)=R$. Furthermore, we
show that the Birkhoff theorem is not a general result for $f(R)$-gravity since
time-dependent evolution for spherically symmetric solutions can be achieved
depending on the order of perturbations. Finally, we discuss the
post-Minkowskian limit and the emergence of massive gravitational wave
solutions.


title: Current-Noise Spectroscopy with a Scanning Tunneling Microscope

abstract: This paper has been withdrawn due to fundamental errors.


title: Discovery of a bright eclipsing cataclysmic variable

abstract:
  We report on the discovery of J0644+3344, a bright deeply eclipsing
cataclysmic variable (CV) binary. Spectral signatures of both binary components
and an accretion disk can be seen at optical wavelengths. The optical spectrum
shows broad H I, He I, and He II accretion disk emission lines with deep narrow
absorption components from H I, He I, Mg II and Ca II. The absorption lines are
seen throughout the orbital period, disappearing only during primary eclipse.
These absorption lines are either the the result of an optically-thick inner
accretion disk or from the photosphere of the primary star. Radial velocity
measurements show that the H I, He I, and Mg II absorption lines phase with the
the primary star, while weak absorption features in the continuum phase with
the secondary star. Radial velocity solutions give a 150+/-4 km/s
semi-amplitude for the primary star and 192.8+/-5.6 km/s for the secondary. The
individual stellar masses are 0.63-0.69 Mdot for the primary and 0.49-0.54 Mdot
for the secondary. The bright eclipsing nature of this binary has helped
provide masses for both components with an accuracy rarely achieved for CVs.
This binary most closely resembles a nova-like UX UMa or SW Sex type of CV.
J0644+3344, however, has a longer orbital period than most UX UMa or SW Sex
stars. Assuming an evolution toward shorter orbital periods, J0644+3344 is
therefore likely to be a young interacting binary. The secondary star is
consistent with the size and spectral type of a K8 star, but has an M0 mass.


title:
High-order numerical method for the nonlinear Helmholtz equation with
  material discontinuities in one space dimension

abstract:
  The nonlinear Helmholtz equation (NLH) models the propagation of
electromagnetic waves in Kerr media, and describes a range of important
phenomena in nonlinear optics and in other areas. In our previous work, we
developed a fourth order method for its numerical solution that involved an
iterative solver based on freezing the nonlinearity. The method enabled a
direct simulation of nonlinear self-focusing in the nonparaxial regime, and a
quantitative prediction of backscattering. However, our simulations showed that
there is a threshold value for the magnitude of the nonlinearity, above which
the iterations diverge. In this study, we numerically solve the one-dimensional
NLH using a Newton-type nonlinear solver. Because the Kerr nonlinearity
contains absolute values of the field, the NLH has to be recast as a system of
two real equations in order to apply Newton's method. Our numerical simulations
show that Newton's method converges rapidly and, in contradistinction with the
iterations based on freezing the nonlinearity, enables computations for very
high levels of nonlinearity. In addition, we introduce a novel compact
finite-volume fourth order discretization for the NLH with material
discontinuities.The one-dimensional results of the current paper create a
foundation for the analysis of multi-dimensional problems in the future.


title: Some calculations on type II_1 unprojection

abstract:
  The type II_1 unprojection is, by definition, the generic complete
intersection type II unprojection, in the sense of [Papadakis, Type II
unprojection, J. Algebraic Geometry, 15 (2006) 399--414] Section 3.1, for the
parameter value k = 1, and depends on a parameter n greater or equal than 2.
Our main results are the explicit calculation of the linear relations of the
type II_1 unprojection for any value of n greater or equal than 2 (Theorem
3.16) and the explicit calculation of the quadratic equation for the case n = 3
(Theorem 4.1). In addition, Section 5 contains applications to algebraic
geometry while Section 6 contains the Macaulay 2 code for the type II_1
unprojection for the parameter value n = 3.


title:
The optimal P3M algorithm for computing electrostatic energies in
  periodic systems

abstract:
  We optimize Hockney and Eastwood's Particle-Particle Particle-Mesh (P3M)
algorithm to achieve maximal accuracy in the electrostatic energies (instead of
forces) in 3D periodic charged systems. To this end we construct an optimal
influence function that minimizes the RMS errors in the energies. As a
by-product we derive a new real-space cut-off correction term, give a
transparent derivation of the systematic errors in terms of Madelung energies,
and provide an accurate analytical estimate for the RMS error of the energies.
This error estimate is a useful indicator of the accuracy of the computed
energies, and allows an easy and precise determination of the optimal values of
the various parameters in the algorithm (Ewald splitting parameter, mesh size
and charge assignment order).


title: Black-hole information puzzle: A generic string-inspired approach

abstract:
  Given the insight steming from string theory, the origin of the black-hole
(BH) information puzzle is traced back to the assumption that it is physically
meaningful to trace out the density matrix over negative-frequency Hawking
particles. Instead, treating them as virtual particles necessarily absorbed by
the BH in a manner consistent with the laws of BH thermodynamics, and tracing
out the density matrix only over physical BH states, the complete evaporation
becomes compatible with unitarity.


title: Effective Theory Approach to W-Pair Production near Threshold

abstract:
  In this talk, I review the effective theory approach to unstable particle
production and present results of a calculation of the process e- e+ ->mu-
nubar_mu u dbar X near the W-pair production threshold up to next-to-leading
order in GammaW/MW ~ alpha ~ v^2. The remaining theoretical uncertainty and the
impact on the measurement of the W mass is discussed.


title: Finding irreducible representation of symmetry operators linearly

abstract:
  The main purpose of this paper is providing a simple method to generate the
matrices of irreducible representations because it is useful to reduce the
computational time of solving the eigenvalue problems. The only information we
need to provide for this method is the group-multiplication table, and the
proof of validity of this method is also shown in this paper.


title: Constant T-curvature conformal metrics on 4-manifolds with boundary

abstract:
  In this paper we prove that, given a compact four dimensional smooth
Riemannian manifold (M,g) with smooth boundary there exists a metric conformal
to g with constant T-curvature, zero Q-curvature and zero mean curvature under
generic and conformally invariant assumptions. The problem amounts to solving a
fourth order nonlinear elliptic boundary value problem (BVP) with boundary
conditions given by a third-order pseudodifferential operator, and homogeneous
Neumann one. It has a variational structure, but since the corresponding
Euler-Lagrange functional is in general unbounded from below, we look for
saddle points. In order to do this, we use topological arguments and min-max
methods combined with a compactness result for the corresponding BVP.


title:
Precise measurement of hadronic $\tau$-decays in modes with $\eta$
  mesons

abstract:
  We have measured branching fractions of hadronic $\tau$ decays involving an
$\eta$ meson using 485 fb^{-1} of data collected with the Belle detector at the
KEKB asymmetric-energy e^+e^- collider. We obtain the following branching
fractions: ${\cal B}(\tau^-\to K^- \eta \nu_{\tau})=(1.62\pm 0.05 \pm
0.09)\times 10^{-4}$, ${\cal B}(\tau^-\to K^- \pi^0 \eta \nu_{\tau}) =(4.7\pm
1.1 \pm 0.4)\times 10^{-5}$, ${\cal B}(\tau^-\to \pi^- \pi^0 \eta
\nu_{\tau})=(1.39 \pm 0.03 \pm 0.07) \times 10^{-3}$, and ${\cal B}(\tau^-\to
K^{*-} \eta \nu_{\tau})=(1.13\pm 0.19 \pm 0.07)\times 10^{-4}$ improving the
accuracy compared to the best previous measurements by factors of six, eight,
four and four, respectively.


title:
The Schr\" odinger picture of the Dirac quantum mechanics on spatially
  flat Robertson-Walker backgrounds

abstract:
  The Schr\" odinger picture of the Dirac quantum mechanics is defined in
charts with spatially flat Robertson-Walker metrics and Cartesian coordinates.
The main observables of this picture are identified, including the interacting
part of the Hamiltonian operator produced by the minimal coupling with the
gravitational field. It is shown that in this approach new Dirac quantum modes
on de Sitter spacetimes may be found analytically solving the Dirac equation.


title: Wind emission of OB supergiants and the influence of clumping

abstract:
  The influence of the wind to the total continuum of OB supergiants is
discussed. For wind velocity distributions with \beta > 1.0, the wind can have
strong influence to the total continuum emission, even at optical wavelengths.
Comparing the continuum emission of clumped and unclumped winds, especially for
stars with high \beta values, delivers flux differences of up to 30% with
maximum in the near-IR. Continuum observations at these wavelengths are
therefore an ideal tool to discriminate between clumped and unclumped winds of
OB supergiants.


title:
Overview document for: A weight function theory of basis function
  interpolants and smoothers

abstract:
  This document is a brief overview of two documents which continue to develop
the weight function theory of basis function smoothers and interpolants. One
document considers the zero order theory and one considers the positive order
theory.


title: $\infty$-jets of difeomorphisms preserving orbits of vector fields

abstract:
  Let $F$ be a smooth vector field defined in a neighborhood of the origin in
$\mathbb{R}^n$, $F(O)=0$, and let $F_t$ be its local flow. Denote by $E$ the
set of germs of diffeomorphisms $h:\mathbb{R}^n \to \mathbb{R}^n$ preserving
orbits of $F$ and let $E_{\mathrm{id}}^r$ be the identity component of $E$ with
respect to $C^r$-topology. Then every $E_{\mathrm{id}}^{r}$ contains a subset
$Sh$ consisting of mappings of the form $F_{f(x)}(x)$, where $f: \mathbb{R}^n
\to \mathbb{R}$ is a smooth function. It was proved earlier by the author that
if $F$ is a linear vector field, then $Sh=E_{\mathrm{id}}^0$. In this paper we
present a class of vector fields for which $Sh$ and $E_{\mathrm{id}}^1$
coincide on the level of $\infty$-jets. We also establish a parameter rigidity
of linear vector fields and "reduced" Hamiltonian vector fields of real
homogeneous polynomials in two variables.


title: 6th and 8th Order Hermite Integrator for N-body Simulations

abstract:
  We present sixth- and eighth-order Hermite integrators for astrophysical
$N$-body simulations, which use the derivatives of accelerations up to second
order ({\it snap}) and third order ({\it crackle}). These schemes do not
require previous values for the corrector, and require only one previous value
to construct the predictor. Thus, they are fairly easy to implemente. The
additional cost of the calculation of the higher order derivatives is not very
high. Even for the eighth-order scheme, the number of floating-point operations
for force calculation is only about two times larger than that for traditional
fourth-order Hermite scheme. The sixth order scheme is better than the
traditional fourth order scheme for most cases. When the required accuracy is
very high, the eighth-order one is the best. These high-order schemes have
several practical advantages. For example, they allow a larger number of
particles to be integrated in parallel than the fourth-order scheme does,
resulting in higher execution efficiency in both general-purpose parallel
computers and GRAPE systems.


title: Segregation in noninteracting binary mixture

abstract:
  Process of stripe formation is analyzed numerically in a binary mixture. The
system consists of particles of two sizes, without any direct mutual
interactions. Overlapping of large particles, surrounded by a dense system of
smaller particles induces indirect entropy driven interactions between large
particles. Under an influence of an external driving force the system orders
and stripes are formed. Mean width of stripes grows logarithmically with time,
in contrast to a typical power law temporal increase observed for driven
interacting lattice gas systems. We describe the mechanism responsible for this
behavior and attribute the logarithmic growth to a random walk of large
particles in a random potential due to the small ones.


title: Work and heat probability distributions in out-of-equilibrium systems

abstract:
  We review and discuss the equations governing the distribution of work done
on a system which is driven out of equilibrium by external manipulation, as
well as those governing the entropy flow to a reservoir in a nonequilibrium
system. We take advantage of these equations to investigate the path phase
transition in a manipulated mean-field Ising model and the large-deviation
function for the heat flow in the asymmetric exclusion process with
periodically varying transition probabilities.


title: Characterising Web Site Link Structure

abstract:
  The topological structures of the Internet and the Web have received
considerable attention. However, there has been little research on the
topological properties of individual web sites. In this paper, we consider
whether web sites (as opposed to the entire Web) exhibit structural
similarities. To do so, we exhaustively crawled 18 web sites as diverse as
governmental departments, commercial companies and university departments in
different countries. These web sites consisted of as little as a few thousand
pages to millions of pages. Statistical analysis of these 18 sites revealed
that the internal link structure of the web sites are significantly different
when measured with first and second-order topological properties, i.e.
properties based on the connectivity of an individual or a pairs of nodes.
However, examination of a third-order topological property that consider the
connectivity between three nodes that form a triangle, revealed a strong
correspondence across web sites, suggestive of an invariant. Comparison with
the Web, the AS Internet, and a citation network, showed that this third-order
property is not shared across other types of networks. Nor is the property
exhibited in generative network models such as that of Barabasi and Albert.


title:
The response of self-graviting protostellar discs to slow reduction in
  cooling timescale: the fragmentation boundary revisited

abstract:
  A number of previous studies of the fragmentation of self-gravitating
protostellar discs have modeled radiative cooling with a cooling timescale
(t_{cool}) parameterised as a simple multiple (beta_{cool}) of the local
dynamical timescale. Such studies have delineated the `fragmentation boundary'
in terms of a critical value of beta_{cool} (beta_{crit}), where the disc
fragments if beta_{cool} < beta_{crit}. Such an approach however begs the
question of how in reality a disc could ever be assembled with beta_{cool} <
beta_{crit}. Here we adopt the more realistic approach of gradually reducing
beta_{cool}, as might correspond to changes in thermal regime due to secular
changes in the disc density profile. We find that when beta_{cool} is gradually
reduced (on a timescale longer than t_{cool}), the disc is stabilised against
fragmentation, compared with models in which beta_{cool} is reduced rapidly. We
therefore conclude that a disc's ability to remain in a self-regulated,
self-gravitating state (without fragmentation) is partly dependent on its
thermal history, as well as its current cooling rate. Nevertheless, a slow
reduction in t_{cool} appears only to lower the fragmentation boundary by about
a factor two in t_{cool} and thus only permits maximum alpha values
(parameterising the efficiency of angular momentum transfer in the disc) that
are about a factor two higher than determined hitherto. Our results therefore
do not undermine the notion of a fundamental upper limit to the heating rate
that can be delivered by gravitational instabilities before the disc is subject
to fragmentation. An important implication of this work, therefore, is that
self-gravitating discs can enter into the regime of fragmentation via secular
evolution and it is not necessary to invoke rapid (impulsive) events to trigger
fragmentation.


title: Bouncing Negative-Tension Branes

abstract:
  Braneworlds, understood here as double domain wall spacetimes, can be
described in terms of a linear harmonic function, with kinks at the locations
of the boundary branes. In a dynamical setting, there is therefore the risk
that the boundary brane of negative tension, at whose location the value of the
harmonic function is always lowest, can encounter a zero of this harmonic
function, corresponding to the formation of a singularity. We show that for
certain types of brane-bound matter this singularity can be avoided, and the
negative-tension brane can shield the bulk spacetime from the singularity by
bouncing back smoothly before reaching the singularity. In our analysis we
compare the 5- and 4-dimensional descriptions of this phenomenon in order to
determine the validity of the moduli space approximation.


title: Prime ideals in the quantum grassmannian

abstract:
  We consider quantum Schubert cells in the quantum grassmannian and give a
cell decomposition of the prime spectrum via the Schubert cells. As a
consequence, we show that all primes are completely prime in the generic case
where the deformation parameter q is not a root of unity. There is a torus H
that acts naturally on the quantum grassmannian and the cell decomposition of
the set of H-primes leads to a parameterisation of the H-spectrum via certain
diagrams on partitions associated to the Schubert cells. Interestingly, the
same parameterisation occurs for the non-negative cells in recent studies
concerning the totally non-negative grassmannian. Finally, we use the cell
decomposition to establish that the quantum grassmannian satisfies normal
separation and catenarity.


title:
Coulomb corrections to the Delbrueck scattering amplitude at low
  energies

abstract:
  In this article, we study the Coulomb corrections to the Delbrueck scattering
amplitude. We consider the limit when the energy of the photon is much less
than the electron mass. The calculations are carried out in the coordinate
representation using the exact relativistic Green function of an electron in a
Coulomb field. The resulting relative corrections are of the order of a few
percent for scattering on for a large charge of the nucleus. We compare the
corrections with the corresponding ones calculated through the dispersion
integral of the pair production cross section and also with the magnetic loop
contribution to the g-factor of a bound electron. The last one is in a good
agreement with our results but the corrections calculated through the
dispersion relation are not.


title: Multiferroic nature of charge-ordered rare earth manganites

abstract:
  Charge-ordered rare earth manganites Nd0.5Ca0.5MnO3, La0.25Nd0.25Ca0.5MnO3,
Pr0.7Ca0.3MnO3 and Pr0.6Ca0.4MnO3 are found to exhibit dielectric constant
anomalies around the charge-ordering or the magnetic transition temperatures.
Magnetic fields have a marked effect on the dielectric properties, indicating
the presence of coupling between the magnetic and electrical order parameters.
The observation of magnetoferroelectricity in these manganites is in accord
with the recent theoretical predictions of Khomskii and coworkers.


title: The decomposition of the hypermetric cone into L-domains

abstract:
  The hypermetric cone $\HYP_{n+1}$ is the parameter space of basic Delaunay
polytopes in n-dimensional lattice. The cone $\HYP_{n+1}$ is polyhedral; one
way of seeing this is that modulo image by the covariance map $\HYP_{n+1}$ is a
finite union of L-domains, i.e., of parameter space of full Delaunay
tessellations.
  In this paper, we study this partition of the hypermetric cone into
L-domains. In particular, it is proved that the cone $\HYP_{n+1}$ of
hypermetrics on n+1 points contains exactly {1/2}n! principal L-domains. We
give a detailed description of the decomposition of $\HYP_{n+1}$ for n=2,3,4
and a computer result for n=5 (see Table \ref{TableDataHYPn}). Remarkable
properties of the root system $\mathsf{D}_4$ are key for the decomposition of
$\HYP_5$.


title: Collisionless damping of electron waves in non-Maxwellian plasma

abstract:
  In this paper we have criticized the so-called Landau damping theory. We have
analyzed solutions of the standard dispersion equations for longitudinal
(electric) and transversal (electromagnetic and electron) waves in
half-infinite slab of the uniform collisionless plasmas with non-Maxwellian and
Maxwellian-like electron energy distribution functions. One considered the most
typical cases of both the delta-function type distribution function (the plasma
stream with monochromatic electrons) and distribution functions, different from
Maxwellian ones as with a surplus as well as with a shortage in the Maxwellian
distribution function tail. It is shown that there are present for the
considered cases both collisionless damping and also non-damping electron waves
even in the case of non-Maxwellian distribution function.


title:
Nodal free geometric phases: Concept and application to geometric
  quantum computation

abstract:
  Nodal free geometric phases are the eigenvalues of the final member of a
parallel transporting family of unitary operators. These phases are gauge
invariant, always well-defined, and can be measured interferometrically. Nodal
free geometric phases can be used to construct various types of quantum phase
gates.


title: On the q-quantum gravity loop algebra

abstract:
  A class of deformations of the q-quantum gravity loop algebra is shown to be
incompatible with the combinatorics of Temperley-Lieb recoupling theory with
deformation parameter at a root of unity. This incompatibility appears to
extend to more general deformation parameters.


title:
On the relativistic iron line and soft excess in the Seyfert 1 galaxy
  Markarian 335

abstract:
  We report on a 133 ks XMM-Newton observation of the Seyfert 1 galaxy
Markarian 335. The 0.4-12 keV spectrum contains an underlying power law
continuum, a soft excess below 2 keV, and a double-peaked iron emission feature
in the 6-7 keV range. We investigate the possibility that the double-peaked
emission might represent the characteristic signature of the accretion disc.
Detailed investigations show that a moderately broad, accretion disc line is
most likely present, but that the peaks may be owing to narrower components
from more distant material. The peaks at 6.4 and 7 keV can be identified,
respectively, with the molecular torus in active galactic nucleus unification
schemes, and very highly ionized, optically thin gas filling the torus. The
X-ray variability spectra on both long (~100 ks) and short (~1 ks) timescales
disfavour the recent suggestion that the soft excess is an artifact of
variable, moderately ionized absorption.


title:
Two-color photoassociation spectroscopy of ytterbium atoms and the
  precise determinations of s-wave scattering lengths

abstract:
  By performing high-resolution two-color photoassociation spectroscopy, we
have successfully determined the binding energies of several of the last bound
states of the homonuclear dimers of six different isotopes of ytterbium. These
spectroscopic data are in excellent agreement with theoretical calculations
based on a simple model potential, which very precisely predicts the s-wave
scattering lengths of all 28 pairs of the seven stable isotopes. The s-wave
scattering lengths for collision of two atoms of the same isotopic species are
13.33(18) nm for ^{168}Yb, 3.38(11) nm for ^{170}Yb, -0.15(19) nm for ^{171}Yb,
-31.7(3.4) nm for ^{172}Yb, 10.55(11) nm for ^{173}Yb, 5.55(8) nm for ^{174}Yb,
and -1.28(23) nm for ^{176}Yb. The coefficient of the lead term of the
long-range van der Waals potential of the Yb_2 molecule is C_6=1932(30) atomic
units $(E_h a_0^6 \approx 9.573\times 10^{-26}$ J nm^6).


title:
The Baryonic and Dark Matter Properties of High Redshift Gravitationally
  Lensed Disk Galaxies

abstract:
  We present a detailed study of the structural properties of four
gravitationally lensed disk galaxies at z=1. Modelling the rotation curves on
sub-kpc scales we derive the values for the disk mass, the reference dark
matter density and core radius, and the angular momentum per unit mass. The
derived models suggest that the rotation curve profile and amplitude are best
fit with a dark matter component similar to those of local spiral galaxies. The
stellar component also has a similar length scale, but with substantially
smaller masses than similarly luminous disk galaxies in the local universe.
Comparing the average dark matter density inside the optical radius we find
that the disk galaxies at z=1 have larger densities (by up to a factor of 7)
than similar disk galaxies in the local Universe. Furthermore, the angular
momentum per unit mass versus reference velocity is well matched to the local
relation, suggesting that the angular momentum of the disk remains constant
between high redshifts and the present day. Though statistically limited, these
observations point towards a spirals' formation scenario in which stellar disks
are slowly grown by the accretion of angular momentum conserving material.


title: Magneto-elastic coupling in hexagonal YMnO_3

abstract:
  We report an ultrasonic investigation of the elastic moduli on a single
crystal of hexagonal YMnO_3 as a function of temperature. Stiffening anomalies
in the antiferromagnetic N\'eel state below T_N = 72.4 K are observed on all
the four elastic moduli C_{ii}. The anomalies are the most important on C_{11}
and C_{66} for in-plane elastic deformations; this is consistent with a strong
coupling of the lattice with the in-plane exchange interactions. We use a
Landau free energy model to account for these elastic anomalies. We derive an
expression which relates the temperature profile of the anomaly to the order
parameter; the critical exponent associated to this parameter $\beta$ = 0.42 is
not consistent with a chiral XY or 3D Heisenberg universality class, but more
in agreement with a conventional antiferromagnetic long range order. A tiny
softening anomaly on C_{11} for which hysteresis effects are observed could be
indicative of an interaction between ferroelectric and magnetic domains at T_N.
Moreover, magnetic fluctuations effects both above and below T_N are identified
through abnormal temperature and magnetic field effects.


title:
Notes on the Self-Reducibility of the Weil Representation and
  Higher-Dimensional Quantum Chaos

abstract:
  In these notes we discuss the "self-reducibility property" of the Weil
representation. We explain how to use this property to obtain sharp estimates
of certain higher-dimensional exponential sums which originate from the theory
of quantum chaos. As a result, we obtain the Hecke quantum unique ergodicity
theorem for generic linear symplectomorphism $A$ of the torus
$T^{2N}=R^{2N}/Z^{2N}.


title:
Singular solutions of some nonlinear parabolic equations with spatially
  inhomogeneous absorption

abstract:
  We study the limit behaviour of solutions of a class of solutions of
nonlinear parabolic equations with a degenerate strong absorption. We prove
that two types of phenomena can occur: the pointwise singularity or the
formation of razor blades (or persistent singularities).


title: Separable solutions of some quasilinear equations with source reaction

abstract:
  We study the existence of singular separable solutions to a class of
quasilinear equations with reaction term. In the 2-dim case, we use a dynamical
system approach to construct our solutions.


title:
A Subgroup of a Direct Product of Free Groups whose Dehn Function has a
  Cubic Lower Bound

abstract:
  We establish a cubic lower bound on the Dehn function of a certain finitely
presented subgroup of a direct product of 3 free groups.


title:
Effective Action in a General Chiral Model: Next to Leading Order
  Derivative Expansion in the Worldline Method

abstract:
  We present a formalism to determine the imaginary part of a general chiral
model in the derivative expansion. Our formalism is based on the worldline path
integral for the covariant current that can be given in an explicit chiral and
gauge covariant form. The effective action is then obtained by integrating the
covariant current, taking account of the anomaly.


title:
De-coupling of Exchange and Persistence Times in Atomistic Models of
  Glass Formers

abstract:
  With molecular dynamics simulations of a fluid mixture of classical particles
interacting with pair-wise additive Weeks-Chandler-Andersen potentials, we
consider the time series of particle displacements and thereby determine
distributions for local persistence times and local exchange times. These basic
characterizations of glassy dynamics are studied over a range of super-cooled
conditions and shown to have behaviors, most notably de-coupling, similar to
those found in kinetically constrained lattice models of structural glasses.
Implications are noted.


title: Statistics of quantum transmission in one dimension with broad disorder

abstract:
  We study the statistics of quantum transmission through a one-dimensional
disordered system modelled by a sequence of independent scattering units. Each
unit is characterized by its length and by its action, which is proportional to
the logarithm of the transmission probability through this unit. Unit actions
and lengths are independent random variables, with a common distribution that
is either narrow or broad. This investigation is motivated by results on
disordered systems with non-stationary random potentials whose fluctuations
grow with distance.
  In the statistical ensemble at fixed total sample length four phases can be
distinguished, according to the values of the indices characterizing the
distribution of the unit actions and lengths. The sample action, which is
proportional to the logarithm of the conductance across the sample, is found to
obey a fluctuating scaling law, and therefore to be non-self-averaging, in
three of the four phases. According to the values of the two above mentioned
indices, the sample action may typically grow less rapidly than linearly with
the sample length (underlocalization), more rapidly than linearly
(superlocalization), or linearly but with non-trivial sample-to-sample
fluctuations (fluctuating localization).


title: Red Halos of Galaxies - Reservoirs of Baryonic Dark Matter?

abstract:
  Deep optical/near-IR surface photometry of galaxies outside the Local Group
have revealed faint and very red halos around objects as diverse as disk
galaxies and starbursting dwarf galaxies. The colours of these structures are
too extreme to be reconciled with stellar populations similar to those seen in
the stellar halos of the Milky Way or M31, and alternative explanations like
dust reddening, high metallicities or nebular emission are also disfavoured. A
stellar population obeying an extremely bottom-heavy initial mass function
(IMF), is on the other hand consistent with all available data. Because of its
high mass-to-light ratio, such a population would effectively behave as
baryonic dark matter and could account for some of the baryons still missing in
the low-redshift Universe. Here, we give an overview of current red halo
detections, alternative explanations for the origin of the red colours and
ongoing searches for red halos around types of galaxies for which this
phenomenon has not yet been reported. A number of potential tests of the
bottom-heavy IMF hypothesis are also discussed.


title:
Diquark approach to calculating the mass and stability of multiquark
  states

abstract:
  By using of vector diquark ideas in the chiral limit diquark correlations in
the relativistic region and imposing HF interactions between quarks in a vector
diquark we calculated the mass of two multiquark states (Theta pentaquark and H
dibaryon), also by using of tunneling method we simultaneously calculated their
decay width


title: Experimental quantum state tomography of a solid state qubit

abstract:
  Full quantum state tomography is used to characterize the state of an
ensemble based qubit implemented through two hyperfine levels in Pr3+ ions,
doped into a Y2SiO5 crystal. We experimentally verify that single-qubit
rotation errors due to inhomogeneities of the ensemble can be suppressed using
the Roos-Moelmer dark state scheme. Fidelities above >90%, presumably limited
by excited state decoherence, were achieved. Although not explicitly taken care
of in the Roos-Moelmer scheme, it appears that also decoherence due to
inhomogeneous broadening on the hyperfine transition is largely suppressed.


title: Anisotropic fluxes and nonlocal interactions in MHD turbulence

abstract:
  We investigate the locality or nonlocality of the energy transfer and of the
spectral interactions involved in the cascade for decaying magnetohydrodynamic
(MHD) flows in the presence of a uniform magnetic field $\bf B$ at various
intensities. The results are based on a detailed analysis of three-dimensional
numerical flows at moderate Reynold numbers. The energy transfer functions, as
well as the global and partial fluxes, are examined by means of different
geometrical wavenumber shells. On the one hand, the transfer functions of the
two conserved Els\"asser energies $E^+$ and $E^-$ are found local in both the
directions parallel ($k_\|$-direction) and perpendicular ($k_\perp$-direction)
to the magnetic guide-field, whatever the ${\bf B}$-strength. On the other
hand, from the flux analysis, the interactions between the two
counterpropagating Els\"asser waves become nonlocal. Indeed, as the ${\bf
B}$-intensity is increased, local interactions are strongly decreased and the
interactions with small $k_\|$ modes dominate the cascade. Most of the energy
flux in the $k_\perp$-direction is due to modes in the plane at $k_\|=0$, while
the weaker cascade in the $k_\|$-direction is due to the modes with $k_\|=1$.
The stronger magnetized flows tends thus to get closer to the weak turbulence
limit where the three-wave resonant interactions are dominating. Hence, the
transition from the strong to the weak turbulence regime occurs by reducing the
number of effective modes in the energy cascade.


title: Invariant rigid geometric structures and smooth projective factors

abstract:
  We consider actions of non-compact simple Lie groups preserving an analytic
rigid geometric structure of algebraic type on a compact manifold. The
structure is not assumed to be unimodular, so an invariant measure may not
exist. Ergodic stationary measures always exist, and when such a measure has
full support, we show the following.
  1) Either the manifold admits a smooth equivariant map onto a homogeneous
projective variety, defined on an open dense conull invariant set, or the Lie
algebra of the Zariski closure of the Gromov representation of the fundamental
group contains a Lie subalgebra isomorphic to the Lie algebra of the acting
group. As a corollary, a smooth non-trivial homogeneous projective factor does
exist whenever the fundamental group of $M$ admits only virtually solvable
linear representations, and thus in particular when $M$ is simply connected,
regardless of the real rank.
  2) There exist explicit examples showing that analytic rigid actions of
certain simple groups (of real rank one) may indeed fail to have a smooth
projective factor.
  3) It is possible to generalize Gromov's theorem on the algebraic hull of the
representation of the fundamental group of the manifold to the case of analytic
rigid non-unimodular structures, for actions of simple groups of any real rank.
  An important ingredient in the proofs is a generalization of Gromov's
centralizer theorem beyond the case of invariant measures.


title:
Collisionsless amplifying of longitudinal electron waves in two-stream
  plasma

abstract:
  To better understanding the principal features of collisionless
damping/growing plasma waves we have implemented a demonstrative calculation
for the simplest cases of electron waves in two-stream plasmas with the
delta-function type electron velocity distribution function of each of the
streams with velocities v(1) and v(2). The traditional dispersion equation is
reduced to an algebraic 4th order equation, for which numerical solutions are
presented for a variant of equal stream densities. In the case of uniform
half-infinite slab one finds two dominant type solutions: non-damping forward
waves and forward complex conjugated exponentially both damping and growing
waves. Beside it in this case there is no necessity of calculation any
logarithmically divergent indefinite integrals. The possibility of wave
amplifying might be useful in practical applications.


title: Measurement of single electron emission in two-phase xenon

abstract:
  We present the first measurements of the electroluminescence response to the
emission of single electrons in a two-phase noble gas detector. Single
ionization electrons generated in liquid xenon are detected in a thin gas layer
during the 31-day background run of the ZEPLIN-II experiment, a two-phase xenon
detector for WIMP dark matter searches. Both the pressure dependence and
magnitude of the single-electron response are in agreement with previous
measurements of electroluminescence yield in xenon. We discuss different
photoionization processes as possible cause for the sample of single electrons
studied in this work. This observation may have implications for the design and
operation of future large-scale two-phase systems.


title: Fragmentation functions for pions, kaons, protons and charged hadrons

abstract:
  We present new sets of pion, kaon, proton and inclusive charged hadron
fragmentation functions obtained in NLO combined analyses of single-inclusive
hadron production in electron-positron annihilation, proton-proton collisions,
and deep-inelastic lepton-proton scattering with either particles identified in
the final state. At variance with all previous fits, the present analyses take
into account data where hadrons of different electrical charge are identified,
which allow to discriminate quark from anti-quark fragmentation functions.


title: Control of atomic entanglement by dynamic Stark effect

abstract:
  We study the entanglement properties of two three-level Rydberg atoms passing
through a single-mode cavity. The interaction of an atom with the cavity field
allows the atom to make a transition from the upper most (lower most) to the
lower most (upper most) level by emission (absoprtion) of two photons via the
middle level. We employ an effective Hamiltonian that describes the system with
a Stark shifted two-photon atomic transition. We compute the entanglement of
formation of the joint two-atom state as a function of Rabi angle $gt$. It is
shown that the Stark shift can be used to enhance the magnitude of atomic
entanglement over that obtained in the resonant condition for certain parameter
values. We find that though the two-atom entanglement generally diminishes with
the increase of the two-photon detuning and the Stark shift, it is possible to
sustain the entanglement over a range of interaction times by making the
detuning and the Stark shift compensate each other. Similar characteristics are
obtained for a thermal state cavity field too.


title: Ejection of Supermassive Black Holes from Galaxy Cores

abstract:
  [Abridged] Recent numerical relativity simulations have shown that the
emission of gravitational waves during the merger of two supermassive black
holes (SMBHs) delivers a kick to the final hole, with a magnitude as large as
4000 km/s. We study the motion of SMBHs ejected from galaxy cores by such kicks
and the effects on the stellar distribution using high-accuracy direct N-body
simulations. Following the kick, the motion of the SMBH exhibits three distinct
phases. (1) The SMBH oscillates with decreasing amplitude, losing energy via
dynamical friction each time it passes through the core. Chandrasekhar's theory
accurately reproduces the motion of the SMBH in this regime if 2 < ln Lambda <
3 and if the changing core density is taken into account. (2) When the
amplitude of the motion has fallen to roughly the core radius, the SMBH and
core begin to exhibit oscillations about their common center of mass. These
oscillations decay with a time constant that is at least 10 times longer than
would be predicted by naive application of the dynamical friction formula. (3)
Eventually, the SMBH reaches thermal equilibrium with the stars. We estimate
the time for the SMBH's oscillations to damp to the Brownian level in real
galaxies and infer times as long as 1 Gyr in the brightest galaxies. Ejection
of SMBHs also results in a lowered density of stars near the galaxy center;
mass deficits as large as five times the SMBH mass are produced for kick
velocities near the escape velocity. We compare the N-body density profiles
with luminosity profiles of early-type galaxies in Virgo and show that even the
largest observed cores can be reproduced by the kicks, without the need to
postulate hypermassive binary SMBHs. Implications for displaced AGNs and
helical radio structures are discussed.


title:
Design of a mode converter for efficient light-atom coupling in free
  space

abstract:
  In this article, we describe how to develop a mode converter that transforms
a plane electromagnetic wave into an inward moving dipole wave. The latter one
is intended to bring a single atom or ion from its ground state to its excited
state by absorption of a single photon wave packet with near-100% efficiency.


title: S=-1,-2 baryon-baryon interactions in chiral effective field theory

abstract:
  We have constructed the leading order strangeness S=-1,-2 baryon-baryon
potential in a chiral effective field theory approach. The chiral potential
consists of one-pseudoscalar-meson exchanges and non-derivative four-baryon
contact terms. The potential, derived using SU(3) symmetry constraints,
contains six independent low-energy coefficients. We have solved a regularized
Lippmann-Schwinger equation and achieved a good description of the available
scattering data. Furthermore a correctly bound hypertriton has been obtained.


title:
Ergodicity of the $\Delta_3$ statistic and purity of neutron resonance
  data

abstract:
  The $\Delta_3(L)$ statistic characterizes the fluctuations of the number of
levels as a function of the length of the spectral interval. It is studied as a
possible tool to indicate the regular or chaotic nature of underlying dynamics,
detect missing levels and the mixing of sequences of levels of different
symmetry, particularly in neutron resonance data. The relation between the
ensemble average and the average over different fragments of a given
realization of spectra is considered. A useful expression for the variance of
$\Delta_3(L)$ which accounts for finite sample size is discussed. An analysis
of neutron resonance data presents the results consistent with a maximum
likelihood method applied to the level spacing distribution.


title: Breit type equation for mesonic atoms

abstract:
  The finite size effects and relativistic corrections in pionic and kaonic
hydrogen are evaluated by generalizing the Breit equation for a spin-0 -
spin-1/2 amplitude with the inclusion of the hadron electromagnetic form
factors. The agreement of the relativistic corrections to the energies of the
mesonic atoms with other methods used to evaluate them is not exact, but
reasonably good. The precision values of the energy shifts due to the strong
interaction, extracted from data, are however subject to the hadronic form
factor uncertainties.


title:
Time scale competition leading to fragmentation and recombination
  transitions in the coevolution of network and states

abstract:
  We study the co-evolution of network structure and node states in a model of
multiple state interacting agents. The system displays two transitions, network
recombination and fragmentation, governed by time scales that emerge from the
dynamics. The recombination transition separates a frozen configuration,
composed by disconnected network components whose agents share the same state,
from an active configuration, with a fraction of links that are continuously
being rewired. The nature of this transition is explained analytically as the
maximum of a characteristic time. The fragmentation transition, that appears
between two absorbing frozen phases, is an anomalous order-disorder transition,
governed by a crossover between the time scales that control the structure and
state dynamics.