title: The Anisotropic Distribution of Satellite Galaxies

abstract:
  We identify satellites of isolated galaxies in SDSS and examine their angular
distribution. Using mock catalogues generated from cosmological N-body
simulations, we demonstrate that the selection criteria used to select isolated
galaxies and their satellites must be very strict in order to correctly
identify systems in which the primary galaxy dominates its environment. The
criteria used in many previous studies instead select predominantly group
members. We refine a set of selection criteria for which the group
contamination is estimated to be less than 7% and present a catalogue of the
resulting sample. The angular distribution of satellites about their host is
biased towards the major axes for spheroidal galaxies and probably also for red
disc galaxies, but is isotropic for blue disc galaxies, i.e. it is the colour
of the host that determines the distribution of its satellites rather than its
morphology. The similar anisotropy measured in this study as in studies that
were dominated by groups implies that group-specific processes are not
responsible for the angular distribution. Satellites that are most likely to
have been recently accreted show a tendancy to lie along the same axis as the
surrounding large scale structure. The orientations of isolated early and
intermediate-type galaxies also align with the surrounding large scale
structures. We discuss the origin of the anisotropic satellite distribution and
consider the implications of our results, critically assessing the respective
roles played by the orientation of the visible galaxy within its dark matter
halo; anisotropic accretion of satellites from the larger scale environment;
and the biased nature of satellites as tracers of the underlying dark matter
subhalo population. (Abridged)


title: Scattering of charge carriers by point defects in bilayer graphene

abstract:
  Theory of scattering of massive chiral fermions in bilayer graphene by radial
symmetric potential is developed. It is shown that in the case when the
electron wavelength is much larger than the radius of the potential the
scattering cross-section is proportional to the electron wavelength. This leads
to the mobility independent on the electron concentration. In contrast with the
case of single-layer, neutral and charged defects are, in general, equally
relevant for the resistivity of the bilayer graphene.


title:
Hydrodynamic Theory of Granular Solids: Permanent, Transient and
  Granular Elasticity

abstract:
  Although fully elastic when static, granular media become transiently elastic
when being slowly sheared -- during which both the elastic energy and stress
relax. Starting from this observation, we cogently derive the framework for
granular hydrodynamics, a set of differential equations consistent with general
principles of physics, especially reversible and irreversible thermodynamics.
In addition, an expression for the granular elastic energy is reviewed and
further discussed.


title:
New 60-cm Radio Survey Telescope with the Sideband-Separating SIS
  Receiver for the 200 GHz Band

abstract:
  We have upgraded the 60-cm radio survey telescope located in Nobeyama, Japan.
We developed a new waveguide-type sideband-separating SIS mixer for the
telescope, which enables the simultaneous detection of distinct molecular
emission lines both in the upper and lower sidebands. Over the RF frequency
range of 205-240 GHz, the single-sideband receiver noise temperatures of the
new mixer are 40-100 K for the 4.0-8.0 GHz IF frequency band. The image
rejection ratios are greater than 10 dB over the same range. For the dual IF
signals obtained by the receiver, we have developed two sets of acousto-optical
spectrometers and a telescope control system. Using the new telescope system,
we successfully detected the 12CO (J=2-1) and 13CO (J=2-1) emission lines
simultaneously toward Orion KL in 2005 March. Using the waveguide-type
sideband-separating SIS mixer for the 200 GHz band, we have initiated the first
simultaneous 12CO (J=2-1) and 13CO (J=2-1) survey of the galactic plane as well
as large-scale mapping observations of nearby molecular clouds.


title: From Elasticity to Hypoplasticity: Dynamics of Granular Solids

abstract:
  "Granular elasticity," useful for calculating static stress distributions in
granular media, is generalized by including the effects of slowly moving,
deformed grains. The result is a hydrodynamic theory for granular solids that
agrees well with models from soil mechanics.


title: Water's Hydrogen Bond Strength

abstract:
  Water is necessary both for the evolution of life and its continuance. It
possesses particular properties that cannot be found in other materials and
that are required for life-giving processes. These properties are brought about
by the hydrogen bonded environment particularly evident in liquid water. Each
liquid water molecule is involved in about four hydrogen bonds with strengths
considerably less than covalent bonds but considerably greater than the natural
thermal energy. These hydrogen bonds are roughly tetrahedrally arranged such
that when strongly formed the local clustering expands, decreasing the density.
Such low density structuring naturally occurs at low and supercooled
temperatures and gives rise to many physical and chemical properties that
evidence the particular uniqueness of liquid water. If aqueous hydrogen bonds
were actually somewhat stronger then water would behave similar to a glass,
whereas if they were weaker then water would be a gas and only exist as a
liquid at sub-zero temperatures. The overall conclusion of this investigation
is that water's hydrogen bond strength is poised centrally within a narrow
window of its suitability for life.


title: A discriminative method to conduct exploratory analyses in networks

abstract:
  This paper, which commented on Newman and Leicht's "Mixture models and
exploratory analysis in networks" (2007, PNAS 104, 9564-9569), has been
withdrawn. The reason for this removal is that we misinterpreted the conceptual
framework that the authors of the original paper use. Specifically, it is
assumed in our paper that the variable theta_ri denotes the *a priori*
probability that there exists an edge from group r to vertex i. The correct
interpretation is that theta_ri denotes the probability that a given edge from
group r connects to vertex i.
  We are very grateful to Mark Newman and Elizabeth Leicht not only for
pointing out our misinterpretation, but also for doing it so politely and
gracefully.


title: Self-consistent massive disks in triaxial dark matter halos

abstract:
  Galactic disks in triaxial dark matter halos become deformed by the
elliptical potential in the plane of the disk in such a way as to counteract
the halo ellipticity. We develop a technique to calculate the equilibrium
configuration of such a disk in the combined disk-halo potential, which is
based on the method of Jog (2000) but accounts for the radial variation in both
the halo potential and the disk ellipticity. This crucial ingredient results in
qualitatively different behavior of the disk: the disk circularizes the
potential at small radii, even for a reasonably low disk mass. This effect has
important implications for proposals to reconcile cuspy halo density profiles
with low surface brightness galaxy rotation curves using halo triaxiality. The
disk ellipticities in our models are consistent with observational estimates
based on two-dimensional velocity fields and isophotal axis ratios.


title:
The effects of the little Higgs models on $t\bar{t} h^0$ production via
  $\gamma \gamma$ collision at linear colliders

abstract:
  In the frameworks of the littlest Higgs($LH$) model and its extension with
T-parity($LHT$), we studied the associated $t\bar th^0$ production process $e^+
e^- \to \gamma\gamma \to t \bar t h^0$ at the future $e^+e^-$ linear colliders
up to QCD next-to-leading order. We present the regions of $\sqrt{s}-f$
parameter space in which the $LH$ and $LHT$ effects can and cannot be
discovered with the criteria assumed in this paper. The production rates of
process $\gamma\gamma \to t \bar t h^0$ in different photon polarization
collision modes are also discussed. We conclude that one could observe the
effects contributed by the $LH$ or $LHT$ model on the cross section for the
process $e^+ e^- \to \gamma\gamma \to t \bar t h^0$ in a reasonable parameter
space, or might put more stringent constraints on the $LH$/$LHT$ parameters in
the future experiments at linear colliders.


title:
Evidence for high-temperature topological order in an asymmetric quantum
  Hall system

abstract: Further experiments showed the incorrectness of proposed interpretation.


title: Asymptotic behavior of w in general quintom model

abstract:
  For the quintom models with arbitrary potential $V=V(\phi,\sigma)$, the
asymptotic value of equation of state parameter w is obtained by a new method.
In this method, w of stable attractors are calculated by using the ratio (d ln
V)/(d ln a) in asymptotic region. All the known results, have been obtained by
other methods, are reproduced by this method as specific examples.


title: Domain Wall/Cosmology correspondence in (AdS/dS)_6 x S^4 geometries

abstract:
  We investigate the ten dimensional origin of six dimensional F_4 variant
supergravity with supersymmetric de Sitter background. We address first the
issue of spontaneous compactification, showing that it consists of a warped
compactification on a four sphere of a variant massive type IIA supergravity.
Moreover we illustrate how the known D4-D8 brane solution, whose near horizon
geometry yields AdS_6 x S^4, is accordingly modified to a system including
Euclidean branes. Finally, we discuss the relation between this latter solution
and the D4-D8 brane system, showing how it represents a generalisation of the
DW/Cosmology correspondence.


title: Particle renormalizations in presence of dissipative environments

abstract:
  We study the Aharonov-Bohm oscillations of a charged particle on a ring of
radius R coupled to a dirty metal environment. With Monte-Carlo methods we
evaluate the curvature of these oscillations which has the form 1/M*R^2, where
M* is an effective mass. We find that at low temperatures T the curvature
approaches at large R>l an R independent M*>M, where l is the mean free path in
the metal. This behavior is also consistent with perturbation theory in the
particle - metal coupling parameter. At finite temperature T we identify
dephasing lengths that scale as T^{-1} at R>l and as T^{-1/4} at R<<l.


title: The rational homotopy type of a blow-up in the stable case

abstract:
  Suppose that f:V->W is an embedding of closed oriented manifolds whose normal
bundle has the structure of a complex vector bundle. It is well known in both
complex and symplectic geometry that one can then construct a manifold W' which
is the blow-up of W along V. Assume that dim(W)>2.dim(V)+2 and that H^1(f) is
injective. We construct an algebraic model of the rational homotopy type of the
blow-up W' from an algebraic model of the embedding and the Chern classes of
the normal bundle. This implies that if the space W is simply connected then
the rational homotopy type of W' depends only on the rational homotopy class of
f and on the Chern classes of the normal bundle.


title:
Antiferromagnetism and Superconductivity in a model of Quasi 1D Organic
  Conductors

abstract:
  I apply a two-step renormalization group method to the study of the
competition between antiferromagnetism (AFM) and superconductivity in an
anisotropic 2D Hubbard model. I show that this simple model captures the
essentials of the ground-state phases of the quasi 1D organic conductors. As
found experimentally, the ground-state phase diagram is mostly AFM. The AFM is
localized in the strong-coupling limit where the electrons are confined in the
chains. It is an SDW in the weak-coupling limit where interchain hopping is
present. There is a tiny region in the weak-coupling regime where transverse
two-particle hopping is dominant over magnetism.


title:
Surface-plasmon wave at the planar interface of a metal film and a
  structurally chiral medium

abstract:
  The solution of a boundary-value problem formulated for a modified
Kretschmann configuration shows that a surface-plasmon wave can be excited at
the planar interface of a sufficiently thin metal film and a nondissipative
structurally chiral medium, provided the exciting plane wave is p-polarized. An
estimate of the wavenumber of the surface-plasmon wave also emerges thereby.


title:
On Zermelo'-like problems: a Gauss-Bonnet inequality and a E. Hopf
  theorem

abstract:
  The goal of this paper is to describe Zermelo's navigation problem on
Riemannian manifolds as a time-optimal control problem and give an efficient
method in order to evaluate its control curvature. We will show that up to
change the Riemannian metric on the manifold the control curvature of Zermelo's
problem has a simple to handle expression which naturally leads to a
generalization of the classical Gauss-Bonnet formula in an inequality. This
Gauss-Bonnet inequality enables to generalize for Zermelo's problems the E.
Hopf theorem on flatness of Riemannian tori without conjugate points.


title:
Anharmonic behavior in Microwave-driven resistivity oscillations in Hall
  bars

abstract:
  We analyzed the magnetoresistivity of a two-dimensional electron system
excited by microwave radiation in a regime of high intensities and low
frequencies. In such a regime, recent experiments show that different features
appear in the magnetoresistivity response which suggest an anharmonic behavior.
These features consist mainly in distorted oscillations and new resonance peaks
at the subharmonics of the cyclotron frequency. We follow the model of
microwave-driven electron orbits motion which become anharmonic when the ratio
of microwave intensity to microwave frequency is large enough.


title:
Optical Characterization of Single Mode Components by new
  Medianfield-method

abstract:
  In this paper a new method for spotsize-measurement for singlemode optical
components is presented. Based from the classical farfield-method where the
measurements are made circular, the mounting of the used rotary stages and the
long measurement time are great disadvantages. In this paper a new planar
method is described which overcomes these problems. Based on the measurement of
a singlemode fiber in accordance with ITU Recommendation G.652 the efficiency
is demonstrated and discussed.


title:
Visible Wavelength Division Multiplex System for use as a Instructional
  Lab System for Higher Education

abstract:
  The demand for high-speed digital communication such as data, video, and the
broadband Internet increases, the required throughput of the modules in
communications systems will also increase. In this paper we present an
instruction system, which works on the basis of a wavelength division multiplex
(WDM) system in the visible spectrum. It is specialised for the academic
training at universities to demonstrate the principles of the WDM techniques.
It works platform independent in combination with active modules in the
training description, short inline videos and interactive diagrams. The system
consists of LEDs in different wavelengths using analog and digital signals.


title: Magnon mode truncation in a rung-dimerized asymmetric spin ladder

abstract:
  An exactly solvable effective model is suggested for an asymmetric spin
ladder with dimerized rungs. Magnon mode truncation originated from magnon
decay (recently observed in the 1D compound ${\rm IPA-CuCl}_3$) is naturally
described within this model. Using Bethe Ansatze we described a one-magnon
sector and obtained relations between interaction constants of the model and
experimentally observable quantities such as the gap and truncation energies,
spin velocity and the truncation wave vector. It is also shown that structure
factor turns to zero at the truncation point.


title:
Material decomposition mechanisms in femtosecond laser interactions with
  metals

abstract:
  A numerical hydrodynamic study of femtosecond laser ablation is presented. A
detailed analysis of material decomposition is performed using a
thermodynamically complete equation of state with separate stable and
metastable phase states and phase boundaries. The lifetime of the metastable
liquid state is estimated based on the classical theory of homogeneous
nucleation. In addition, mechanical fragmentation of the target material is
controlled based on available criteria. As a result, several ablation
mechanisms are observed. A major fraction of the ablated material, however, is
found to originate from the metastable liquid region, which is decomposed
either thermally in the vicinity of the critical point into a liquid-gas
mixture, or mechanically at high strain rate and negative pressure into liquid
droplets and chunks. The calculation results explain available experimental
findings.


title:
Correlated radio--X-ray variability of Galactic Black Holes: A
  radio--X-ray flare in Cygnus X-1

abstract:
  We report on the first detection of a quasi-simultaneous radio-X-ray flare of
Cygnus X-1. The detection was made on 2005 April 16 with pointed observations
by the Rossi X-ray Timing Explorer and the Ryle telescope, during a phase where
the black hole candidate was close to a transition from the its soft into its
hard state. The radio flare lagged the X-rays by approximately 7 minutes,
peaking at 3:20 hours barycentric time (TDB 2453476.63864). We discuss this lag
in the context of models explaining such flaring events as the ejection of
electron bubbles emitting synchrotron radiation.


title:
Dispersionless limit of the noncommutative potential KP hierarchy and
  solutions of the pseudodual chiral model in 2+1 dimensions

abstract:
  The usual dispersionless limit of the KP hierarchy does not work in the case
where the dependent variable has values in a noncommutative (e.g. matrix)
algebra. Passing over to the potential KP hierarchy, there is a corresponding
scaling limit in the noncommutative case, which turns out to be the hierarchy
of a `pseudodual chiral model' in 2+1 dimensions (`pseudodual' to a hierarchy
extending Ward's (modified) integrable chiral model). Applying the scaling
procedure to a method generating exact solutions of a matrix (potential) KP
hierarchy from solutions of a matrix linear heat hierarchy, leads to a
corresponding method that generates exact solutions of the matrix
dispersionless potential KP hierarchy, i.e. the pseudodual chiral model
hierarchy. We use this result to construct classes of exact solutions of the
su(m) pseudodual chiral model in 2+1 dimensions, including various multiple
lump configurations.


title:
High Resolution Mapping of Phase Behavior in a Ternary Lipid Mixture: Do
  Lipid-Raft Phase Boundaries Depend on Sample-Prep Procedure?

abstract:
  For some time now, we have been using a FRET-based strategy to make
high-resolution studies of phase behavior in ternary lipid-raft membrane
mixtures. Our FRET experiments can be carried out on ordinary, polydisperse
multilamellar vesicle suspensions, so we are able to prepare our samples
according to a procedure that was designed specifically to guard against
artifactual phase separation. In some respects (i.e., the number and nature of
two-phase regions observed), our phase diagrams are consistent with previously
published reports. However, in other respects (i.e., overall size of
miscibility gaps, phase boundary locations and their dependence on temperature)
there are clear differences. Here we present FRET data taken in
DOPC/DPPC/Cholesterol mixtures at 25.0, 35.0 and 45.0oC. Comparisons between
our results and previously reported phase boundaries suggest that lipid-raft
mixtures may be particularly susceptible to demixing effects during sample
preparation.


title: Cosmological dynamics of exponential gravity

abstract:
  We present a detailed investigation of the cosmological dynamics based on
$\exp (-R/{\Lambda})$ gravity. We apply the dynamical system approach to both
the vacuum and matter cases and obtain exact solutions and their stability in
the finite and asymptotic regimes. The results show that cosmic histories exist
which admit a double de-Sitter phase which could be useful for describing the
early and the late-time accelerating universe.


title:
Point-contact Andreev reflection spectroscopy of
  heavy-fermion-metal/superconductor junctions

abstract:
  Our previous point-contact Andreev reflection studies of the heavy-fermion
superconductor CeCoIn$_5$ using Au tips have shown two clear features: reduced
Andreev signal and asymmetric background conductance [1]. To explore their
physical origins, we have extended our measurements to point-contact junctions
between single crystalline heavy-fermion metals and superconducting Nb tips.
Differential conductance spectra are taken on junctions with three
heavy-fermion metals, CeCoIn$_5$, CeRhIn$_5$, and YbAl$_3$, each with different
electron mass. In contrast with Au/CeCoIn$_5$ junctions, Andreev signal is not
reduced and no dependence on effective mass is observed. A possible explanation
based on a two-fluid picture for heavy fermions is proposed. [1] W. K. Park et
al., Phys. Rev. B 72 052509 (2005); W. K. Park et al., Proc. SPIE-Int. Soc.
Opt. Eng. 5932 59321Q (2005); W. K. Park et al., Physica C (in press)
(cond-mat/0606535).


title:
Bosonic String and String Field Theory: a solution using
  Ultradistributions of Exponential Type

abstract:
  In this paper we show that Ultradistributions of Exponential Type (UET) are
appropriate for the description in a consistent way string and string field
theories. A new Lagrangian for the closed string is obtained and shown to be
equivalent to Nambu-Goto's Lagrangian. We also show that the string field is a
linear superposition of UET of compact support CUET). We evaluate the
propagator for the string field, and calculate the convolution of two of them.


title:
Newton law corrections and instabilities in $f(R)$ gravity with the
  effective cosmological constant epoch

abstract:
  We consider class of modified $f(R)$ gravities with the effective
cosmological constant epoch at the early and late universe. Such models pass
most of solar system tests as well they satisfy to cosmological bounds. Despite
their very attractive properties, it is shown that one realistic class of such
models may lead to significant Newton law corrections which become small at the
future universe only. The model with acceptable Newton law regime shows the
matter instability. This suggests that more complicated version of such theory
(or extended parameters space) should be investigated.


title: On the generalization of the Costas property in the continuum

abstract:
  We extend the definition of the Costas property to functions in the
continuum, namely on intervals of the reals or the rationals, and argue that
such functions can be used in the same applications as discrete Costas arrays.
We construct Costas bijections in the real continuum within the class of
piecewise continuously differentiable functions, but our attempts to construct
a fractal-like Costas bijection there are successful only under slight but
necessary deviations from the usual arithmetic laws. Furthermore, we are able,
contingent on the validity of Artin's conjecture, to set up a limiting process
according to which sequences of Welch Costas arrays converge to smooth Costas
bijections over the reals. The situation over the rationals is different:
there, we propose an algorithm of great generality and flexibility for the
construction of a Costas fractal bijection. Its success, though, relies heavily
on the enumerability of the rationals, and therefore it cannot be generalized
over the reals in an obvious way.


title: The Advantages of Four Dimensions for Composite Higgs Models

abstract:
  We examine the relationship between little Higgs and 5d composite models with
identical symmetry structures. By performing an "extreme" deconstruction, one
can reduce any warped composite model to a little Higgs theory on a handful of
sites. This allows us to use 4d intuition and the powerful constraints of
nonlinear sigma models to elucidate obscure points in the original setup. We
find that the finiteness of the Higgs potential in 5d is due to the same
collective symmetry breaking as in the little Higgs. We compare a 4d and a 5d
model with the same symmetry to the data. Reviewing the constraints on models
related to the Minimal Composite Higgs (hep-ph/0412089), we see that it has
difficulty in producing acceptable values for S, T, and m_{top} simultaneously.
By contrast, in a global analysis, the Minimal Moose with custodial symmetry is
viable in a large region of its parameter space and suffers from no numeric
tunings. We conjecture that this result is generic for 4d and 5d models with
identical symmetries. The data will less strongly constrain the little theory.


title:
A geometric invariant theory construction of moduli spaces of stable
  maps

abstract:
  We construct the moduli spaces of stable maps, \bar M_g,n(P^r,d), via
geometric invariant theory (GIT). This construction is only valid over Spec C,
but a special case is a GIT presentation of the moduli space of stable curves
of genus g with n marked points, \bar M_g,n; this is valid over Spec Z. Our
method follows that used in the case n=0 by Gieseker to construct \bar M_g,
though our proof that the semistable set is nonempty is entirely different.


title: Transversality versus Universality for Additive Quantum Codes

abstract:
  Certain quantum codes allow logic operations to be performed on the encoded
data, such that a multitude of errors introduced by faulty gates can be
corrected. An important class of such operations are {\em transversal}, acting
bitwise between corresponding qubits in each code block, thus allowing error
propagation to be carefully limited. If any quantum operation could be
implemented using a set of such gates, the set would be {\em universal}; codes
with such a universal, transversal gate set have been widely desired for
efficient fault-tolerant quantum computation. We study the structure of
GF(4)-additive quantum codes and prove that no universal set of transversal
logic operations exists for these codes. This result strongly supports the idea
that additional primitive operations, based for example on quantum
teleportation, are necessary to achieve universal fault-tolerant computation on
additive codes.


title: Fixed point theorem for discontinuous mappings on PN spaces

abstract:
  We present a study on strong t-continuity and measure of discontinuity on PN
spaces. As an application, we prove a fixed point theorem for a self mapping on
PN spaces by means of measure of discontinuity.


title: Thermodynamic quantum critical behavior of the Kondo necklace model

abstract:
  We obtain the phase diagram and thermodynamic behavior of the Kondo necklace
model for arbitrary dimensions $d$ using a representation for the localized and
conduction electrons in terms of local Kondo singlet and triplet operators. A
decoupling scheme on the double time Green's functions yields the dispersion
relation for the excitations of the system. We show that in $d\geq 3$ there is
an antiferromagnetically ordered state at finite temperatures terminating at a
quantum critical point (QCP). In 2-d, long range magnetic order occurs only at
T=0. The line of Neel transitions for $d>2$ varies with the distance to the
quantum critical point QCP $|g|$ as, $T_N \propto |g|^{\psi}$ where the shift
exponent $\psi=1/(d-1)$. In the paramagnetic side of the phase diagram, the
spin gap behaves as $\Delta\approx \sqrt{|g|}$ for $d \ge 3$ consistent with
the value $z=1$ found for the dynamical critical exponent. We also find in this
region a power law temperature dependence in the specific heat for
$k_BT\gg\Delta$ and along the non-Fermi liquid trajectory. For $k_BT
\ll\Delta$, in the so-called Kondo spin liquid phase, the thermodynamic
behavior is dominated by an exponential temperature dependence.


title: On (g, \phi)-contraction in fuzzy metric spaces

abstract:
  In this paper, we give a generalization of Hicks type contractions and Golet
type contractions on fuzzy metric spaces. We prove some fixed point theorems
for this new type contractions mappings on fuzzy metric spaces.


title:
Interface Width and Bulk Stability: requirements for the simulation of
  Deeply Quenched Liquid-Gas Systems

abstract:
  Simulations of liquid-gas systems with extended interfaces are observed to
fail to give accurate results for two reasons: the interface can get ``stuck''
on the lattice or a density overshoot develops around the interface. In the
first case the bulk densities can take a range of values, dependent on the
initial conditions. In the second case inaccurate bulk densities are found. In
this communication we derive the minimum interface width required for the
accurate simulation of liquid gas systems with a diffuse interface. We
demonstrate this criterion for lattice Boltzmann simulations of a van der Waals
gas. When combining this criterion with predictions for the bulk stability we
can predict the parameter range that leads to stable and accurate simulation
results. This allows us to identify parameter ranges leading to high density
ratios of over 1000. This is despite the fact that lattice Boltzmann
simulations of liquid-gas systems were believed to be restricted to modest
density ratios of less than 20.


title:
Theory of Neutron Scattering in High-T$_c$ Cuprates: Two Component
  Spin-Fermion Model

abstract:
  Recent neutron scattering experiments have revealed that the generic form of
the magnetic excitations in the high-Tc cuprates of wide range of doping has
the so-called "hourglass" shape; it features both upward and downward
excitations at the incommensurate (IC) momenta spanning from the resonance peak
at the commensurate momentum $(\pi,\pi)$. We propose the two-component
spin-fermion model as a minimal phenomenological model which has both local
spins and itinerant fermions as independent degrees of freedom. Our
calculations of the dynamic spin correlation function provide good agreement
with experiments and show: (1) the upward dispersion branch of magnetic
excitations is mostly due to the local spin excitations; (2) the downward
dispersion branch is from collective spin excitations of fermions; (3) the
resonance mode is a mixture of both degrees of freedom.


title: Wall-Crossing Morphisms in Khovanov-Rozansky Homology

abstract:
  We define a wall-crossing morphism for Khovanov-Rozansky homology; that is, a
map between the KR homology of knots related by a crossing change. Using this
map, we extend KR homology to an invariant of singular knots categorifying the
Vasilliev derivative of the HOMFLY polynomial, and of $\mathfrak{sl}_n$ quantum
invariants.


title:
Core-shell structures in single flexible-semiflexible block copolymers:
  Finding the free energy minimum for the folding transition

abstract:
  We investigate the folding transition of a single diblock copolymer
consisting of a semiflexible and a flexible block. We obtain a {\it
Saturn-shaped} core-shell conformation in the folded state, in which the
flexible block forms a core and the semiflexible block wraps around it. We
demonstrate two distinctive features of the core-shell structures: (i) The
kinetics of the folding transition in the copolymer are significantly more
efficient than those of a semiflexible homopolymer. (ii) The core-shell
structure does not depend on the transition pathway.


title:
Strong atom-field coupling for Bose-Einstein condensates in an optical
  cavity on a chip

abstract:
  An optical cavity enhances the interaction between atoms and light, and the
rate of coherent atom-photon coupling can be made larger than all decoherence
rates of the system. For single atoms, this strong coupling regime of cavity
quantum electrodynamics (cQED) has been the subject of spectacular experimental
advances, and great efforts have been made to control the coupling rate by
trapping and cooling the atom towards the motional ground state, which has been
achieved in one dimension so far. For N atoms, the three-dimensional ground
state of motion is routinely achieved in atomic Bose-Einstein condensates
(BECs), but although first experiments combining BECs and optical cavities have
been reported recently, coupling BECs to strong-coupling cavities has remained
an elusive goal. Here we report such an experiment, which is made possible by
combining a new type of fibre-based cavity with atom chip technology. This
allows single-atom cQED experiments with a simplified setup and realizes the
new situation of N atoms in a cavity each of which is identically and strongly
coupled to the cavity mode. Moreover, the BEC can be positioned
deterministically anywhere within the cavity and localized entirely within a
single antinode of the standing-wave cavity field. This gives rise to a
controlled, tunable coupling rate, as we confirm experimentally. We study the
heating rate caused by a cavity transmission measurement as a function of the
coupling rate and find no measurable heating for strongly coupled BECs. The
spectrum of the coupled atoms-cavity system, which we map out over a wide range
of atom numbers and cavity-atom detunings, shows vacuum Rabi splittings
exceeding 20 gigahertz, as well as an unpredicted additional splitting which we
attribute to the atomic hyperfine structure.


title: Elastic scattering theory and transport in graphene

abstract:
  Electron properties of graphene are described in terms of Dirac fermions.
Here we thoroughly outline the elastic scattering theory for the
two-dimensional massive Dirac fermions in the presence of an axially symmetric
potential. While the massless limit is relevant for pristine graphene, keeping
finite mass allows for generalizations onto situations with broken symmetry
between the two sublattices, and provides a link to the scattering theory of
electrons in a parabolic band. We demonstrate that the Dirac theory requires
short-distance regularization for potentials which are more singular than 1/r.
The formalism is then applied to scattering off a smooth short-ranged
potential. Next we consider the Coulomb potential scattering, where the Dirac
theory is consistent for a point scatterer only for the effective impurity
strength below 1/2. From the scattering phase shifts we obtain the exact
Coulomb transport cross-section in terms of the impurity strength. The results
are relevant for transport in graphene in the presence of impurities that do
not induce scattering between the Dirac points in the Brillouin zone.


title: Two-dimensional N=(2,2) super Yang-Mills theory on computer

abstract:
  We carry out preliminary numerical study of Sugino's lattice formulation
\cite{Sugino:2004qd,Sugino:2004qdf} of the two-dimensional $\mathcal{N}=(2,2)$
super Yang-Mills theory (2d $\mathcal{N}=(2,2)$ SYM) with the gauge group
$\SU(2)$. The effect of dynamical fermions is included by re-weighting a
quenched ensemble by the pfaffian factor. It appears that the complex phase of
the pfaffian due to lattice artifacts and flat directions of the classical
potential are not problematic in Monte Carlo simulation. Various one-point
supersymmetric Ward-Takahashi (WT) identities are examined for lattice spacings
up to $a=0.5/g$ with the fixed physical lattice size $L=4.0/g$, where $g$
denotes the gauge coupling constant in two dimensions. WT identities implied by
an exact fermionic symmetry of the formulation are confirmed in fair accuracy
and, for most of these identities, the quantum effect of dynamical fermions is
clearly observed. For WT identities expected only in the continuum limit, the
results seem to be consistent with the behavior expected from supersymmetry,
although we do not see clear distintion from the quenched simulation. We
measure also the expectation values of renormalized gauge-invariant bi-linear
operators of scalar fields.


title:
A universal property of the monoidal 2-category of cospans of finite
  linear orders and surjections

abstract:
  We prove that the monoidal 2-category of cospans of finite linear orders and
surjections is the universal monoidal category with an object X with a
semigroup and a cosemigroup structures, where the two structures satisfy a
certain 2-dimensional separable algebra condition.


title: Measurement of the CKM angles alpha and gamma at the BaBar experiment

abstract:
  We present recent measurements of the CKM angles alpha and gamma using data
collected by the BaBar detector at the PEP-II asymmetric-energy e+ e- collider
at the Stanford Linear Accelerator Center. In addition to constraints on alpha
from the decays B0 -> pi+ pi-, B0 -> rho+ pi- and B0 -> rho+ rho-, we also
report the first measurement of time-dependent CP asymmetries in the decay B0
-> a1+(1260) pi-. We present measurements of gamma in B+ -> D(*)0 K+ decays
using a Dalitz analysis in the modes D^0 -> Ks pi+ pi- and D^0 -> pi+ pi- pi0.


title: Opportunistic Network Coding for Video Streaming over Wireless

abstract:
  In this paper, we study video streaming over wireless networks with network
coding capabilities. We build upon recent work, which demonstrated that network
coding can increase throughput over a broadcast medium, by mixing packets from
different flows into a single packet, thus increasing the information content
per transmission. Our key insight is that, when the transmitted flows are video
streams, network codes should be selected so as to maximize not only the
network throughput but also the video quality. We propose video-aware
opportunistic network coding schemes that take into account both (i) the
decodability of network codes by several receivers and (ii) the importance and
deadlines of video packets. Simulation results show that our schemes
significantly improve both video quality and throughput.


title: A universal enveloping for L-infinity algebras

abstract:
  For any L-infinity algebra L, we construct an A-infinity structure on the
space of symmetric tensors Sym*(L), which generalizes the classical universal
enveloping for Lie algebras. Our construction is based on an invariant homotopy
on a cobar construction of the symmetric coalgebra, which is obtained through
its relation with permutahedra and Young tableaux.


title: Towards A Realistic Grand Gauge-Higgs Unification

abstract:
  We investigate a 5D SU(6) grand gauge-Higgs unification model compactified on
an orbifold S^1/Z_2. Ordinary quarks and leptons, together with right-handed
neutrinos, are just accommodated into a minimal set of representations of the
gauge group, without introducing any exotic states. The proton decay turns out
to be forbidden at least at the tree level. We also find a correct electroweak
symmetry breaking SU(2)_L \times U(1)_Y \to U(1)_{em} is easily realized by
introducing suitable number of adjoint fermions.


title: BGG correspondence for toric complete intersections

abstract:
  We generalize the classical Bernstein-Gelfand-Gelfand correspondence to
complete intersections in toric varieties.


title:
Duality and Stability Regions of Multi-rate Broadcast and Multiple
  Access Networks

abstract:
  We characterize stability regions of two-user fading Gaussian multiple access
(MAC) and broadcast (BC) networks with centralized scheduling. The data to be
transmitted to the users is encoded into codewords of fixed length. The rates
of the codewords used are restricted to a fixed set of finite cardinality. With
successive decoding and interference cancellation at the receivers, we find the
set of arrival rates that can be stabilized over the MAC and BC networks. In
MAC and BC networks with average power constraints, we observe that the duality
property that relates the MAC and BC information theoretic capacity regions
extend to their stability regions as well. In MAC and BC networks with peak
power constraints, the union of stability regions of dual MAC networks is found
to be strictly contained in the BC stability region.


title: Electronic structure of NaWO$_3$: Role of the impurity potential

abstract:
  We have performed {\it ab-initio} electronic structure calculations to
determine the evolution of the electronic structure of WO$_3$ with Na doping.
Na doping introduces an additional electron when introduced into WO$_3$. The
ensuing electronic structure of Na doped WO$_3$, we find, is very similar to
the electronic structure of an electron introduced into WO$_3$, thus clarifying
the role of the impurity potential due to Na. While the electronic structure of
NaWO$_3$ allows a rigid band like description over a certain energy range,
modifications introduced in the electronic structure can be related back to the
electron due to Na and not the impurity potential that one generally believes
to be responsible.


title:
Controlling for individual heterogeneity in longitudinal models, with
  applications to student achievement

abstract:
  Longitudinal data tracking repeated measurements on individuals are highly
valued for research because they offer controls for unmeasured individual
heterogeneity that might otherwise bias results. Random effects or mixed models
approaches, which treat individual heterogeneity as part of the model error
term and use generalized least squares to estimate model parameters, are often
criticized because correlation between unobserved individual effects and other
model variables can lead to biased and inconsistent parameter estimates.
Starting with an examination of the relationship between random effects and
fixed effects estimators in the standard unobserved effects model, this article
demonstrates through analysis and simulation that the mixed model approach has
a ``bias compression'' property under a general model for individual
heterogeneity that can mitigate bias due to uncontrolled differences among
individuals. The general model is motivated by the complexities of longitudinal
student achievement measures, but the results have broad applicability to
longitudinal modeling.


title:
Analyzing Design Process and Experiments on the AnITA Generic Tutoring
  System

abstract:
  In the field of tutoring systems, investigations have shown that there are
many tutoring systems specific to a specific domain that, because of their
static architecture, cannot be adapted to other domains. As consequence, often
neither methods nor knowledge can be reused. In addition, the knowledge
engineer must have programming skills in order to enhance and evaluate the
system. One particular challenge is to tackle these problems with the
development of a generic tutoring system. AnITA, as a stand-alone application,
has been developed and implemented particularly for this purpose. However, in
the testing phase, we discovered that this architecture did not fully match the
user's intuitive understanding of the use of a learning tool. Therefore, AnITA
has been redesigned to exclusively work as a client/server application and
renamed to AnITA2. This paper discusses the evolvements made on the AnITA
tutoring system, the goal of which is to use generic principles for system
re-use in any domain. Two experiments were conducted, and the results are
presented in this paper.


title: Spin Coulomb drag beyond the random phase approximation

abstract:
  We study the spin Coulomb drag in a quasi-two-dimensional electron gas beyond
the random phase approximation (RPA). We find that the finite transverse width
of the electron gas causes a significant reduction of the spin Coulomb drag.
This reduction, however, is largely compensated by the enhancement coming from
the inclusion of many-body local field effects beyond the RPA, thereby
restoring good agreement with the experimental observations by C. P. Weber
\textit{et al.}, Nature, \textbf{437}, 1330 (2005).


title:
Rate of Convergence of Space Time Approximations for stochastic
  evolution equations

abstract:
  Stochastic evolution equations in Banach spaces with unbounded nonlinear
drift and diffusion operators driven by a finite dimensional Brownian motion
are considered. Under some regularity condition assumed for the solution, the
rate of convergence of various numerical approximations are estimated under
strong monotonicity and Lipschitz conditions. The abstract setting involves
general consistency conditions and is then applied to a class of quasilinear
stochastic PDEs of parabolic type.


title:
The absolute order on the symmetric group, constructible partially
  ordered sets and Cohen-Macaulay complexes

abstract:
  The absolute order is a natural partial order on a Coxeter group W. It can be
viewed as an analogue of the weak order on W in which the role of the
generating set of simple reflections in W is played by the set of all
reflections in W. By use of a notion of constructibility for partially ordered
sets, it is proved that the absolute order on the symmetric group is homotopy
Cohen-Macaulay. This answers in part a question raised by V. Reiner and the
first author. The Euler characteristic of the order complex of the proper part
of the absolute order on the symmetric group is also computed.


title: Jordan structures and non-associative geometry

abstract:
  In this survey paper we give an overview over constructions of geometries
associated to Jordan structures (algebras, triple systems and pairs), featuring
analogs of these constructions with the Lie functor on the one hand and with
the approach of non-commutative geometry on the other hand.


title:
Absolute continuity of the measures of the Dunkl intetwining operator
  and its dualand applications

abstract:
  In this paper we consider the representing measures $\mu_{x},x\in
\QTR{Bbb}{R}^{d}$, and $\nu_{y},y\in \QTR{Bbb}{R}^{d}$, of the Dunkl
intertwining operator and of its dual. When the multiplicity function is
positive, we prove that for all $x\in \QTR{Bbb}{R}_{\QTO{mbox}{reg}}^{d}$ we
have $d\mu_{x}(y)=\QTR{cal}{K}(x,y)dy$ and for almost all $y\in
\QTR{Bbb}{R}^{d}$ we have $d\nu_{y}(x)=\QTR{cal}{K}(x,y)\omega_{k}(x)dx,$ where
$\QTR{cal}{K}(x,.)$ is a positive integrable function on $\QTR{Bbb}{R}^{d}$
with support in $\{y\in \QTR{Bbb}{R}^{d}/\Vert y\Vert \leq \Vert x\Vert \}$ and
the function $\QTR{cal}{K}(.,y)$ is locally integrable on $\QTR{Bbb}{R}^{d}$
with respect to the measure $\omega_{k}(x)dx$ and with support in $\{x\in
\QTR{Bbb}{R}^{d}/\Vert x\Vert \geq \Vert y\Vert \}$. Next we present some
applications of this result.


title: Sensitivity of principal Hessian direction analysis

abstract:
  We provide sensitivity comparisons for two competing versions of the
dimension reduction method principal Hessian directions (pHd). These
comparisons consider the effects of small perturbations on the estimation of
the dimension reduction subspace via the influence function. We show that the
two versions of pHd can behave completely differently in the presence of
certain observational types. Our results also provide evidence that outliers in
the traditional sense may or may not be highly influential in practice. Since
influential observations may lurk within otherwise typical data, we consider
the influence function in the empirical setting for the efficient detection of
influential observations in practice.


title: A Proof of a Recursion for Bessel Moments

abstract:
  We provide a proof of a conjecture in (Bailey, Borwein, Borwein, Crandall
2007) on the existence and form of linear recursions for moments of powers of
the Bessel function $K_0$.


title: Evolutionary Mesh Numbering: Preliminary Results

abstract:
  Mesh numbering is a critical issue in Finite Element Methods, as the
computational cost of one analysis is highly dependent on the order of the
nodes of the mesh. This paper presents some preliminary investigations on the
problem of mesh numbering using Evolutionary Algorithms. Three conclusions can
be drawn from these experiments. First, the results of the up-to-date method
used in all FEM softwares (Gibb's method) can be consistently improved; second,
none of the crossover operators tried so far (either general or problem
specific) proved useful; third, though the general tendency in Evolutionary
Computation seems to be the hybridization with other methods (deterministic or
heuristic), none of the presented attempt did encounter any success yet. The
good news, however, is that this algorithm allows an improvement over the
standard heuristic method between 12% and 20% for both the 1545 and 5453-nodes
meshes used as test-bed. Finally, some strange interaction between the
selection scheme and the use of problem specific mutation operator was
observed, which appeals for further investigation.


title: Finite size effects and 2-string deviations in the spin-1 XXZ chains

abstract:
  In an earlier work [1] J. Suzuki proposed a set of nonlinear integral
equations (NLIE) to describe the excited state spectrum of the integrable
spin-1 XXZ chain in its repulsive regime. In this paper we extend his equations
for the attractive regime of the model, and calculate analytically the
conformal spectrum of the spin chain. We also discuss the typical root
configurations of the thermodynamic limit as well as the 2-string deviations of
certain excited states of the model. Special objects appearing in the NLIE are
also treated with special care.


title:
The Alignments of the Galaxy Spins with the Real-Space Tidal Field
  Reconstructed from the Two Mass Redshift Survey

abstract:
  We report a direct observational evidence for the existence of the galaxy
spin alignments with the real space tidal field. We calculate the real space
tidal field from the real space density field reconstructed recently from the
Two Mass Redshift Survey (2MRS) by Erdogdu et al. in 2006. Using a total of
12122 nearby spiral galaxies from the Tully Galaxy Catalog, we calculate the
orientations of their spin axes relative to the 2MRS tidal field. We find a
clear signal of the intrinsic correlations between the galaxy spins and the
intermediate principal axes of the tidal shears. The null hypothesis of no
correlation is rejected at 99.99 % confidence level. We also investigate the
dependence of the intrinsic correlations on the galaxy morphological type and
the environment. It is found that (i) the intrinsic correlation depends weakly
on the morphological type of the spiral galaxies but tends to decrease slightly
as the type increases; (ii) it is stronger in the high-density regions than in
the low-density regions. The observational result is quantitatively consistent
with analytic prediction based on the tidal torque theory. It is concluded that
the galaxy spin orientations may provide in principle a new complimentary probe
of the dark matter distribution.


title: Evolutionary stability in quantum games

abstract:
  In evolutionary game theory an Evolutionarily Stable Strategy (ESS) is a
refinement of the Nash equilibrium concept that is sometimes also recognized as
evolutionary stability. It is a game-theoretic model, well known to
mathematical biologists, that was found quite useful in the understanding of
evolutionary dynamics of a population. This chapter presents an analysis of
evolutionary stability in the emerging field of quantum games.


title:
Absence of long-range Ni/Mn ordering in ferromagnetic La2NiMnO6 thin
  films

abstract:
  Epitaxial La2NiMnO6 thin films have been grown on (001)-oriented SrTiO3 using
the PLD technique. The thin films are semiconducting and FM with a TC close to
270K, a coercive field of 920Oe, and a saturation magnetization of 5muB per
f.u. TEM, conducted at RT, reveals a majority phase having "I-centered"
structure with a=c=1.4asub and b=2asub along with a minority phase-domains
having "P-type" structure (asub being the lattice parameter of the perovskite
structure). A discusion on the presence of Ni/Mn long-range ordering, in light
of recent literature on double perovskites La2NiMnO6 is presented.


title: Approximate joint measurements of qubit observables

abstract:
  Joint measurements of qubit observables have recently been studied in
conjunction with quantum information processing tasks such as cloning.
Considerations of such joint measurements have until now been restricted to a
certain class of observables that can be characterized by a form of covariance.
Here we investigate conditions for the joint measurability of arbitrary pairs
of qubit observables. For pairs of noncommuting sharp qubit observables, a
notion of approximate joint measurement is introduced. Optimal approximate
joint measurements are shown to lie in the class of covariant joint
measurements. The marginal observables found to be optimal approximators are
generally not among the coarse-grainings of the observables to be approximated.
This yields scope for the improvement of existing joint measurement schemes.
Both the quality of the approximations and the intrinsic unsharpness of the
approximators are shown to be subject to Heisenberg-type uncertainty relations.


title: Anatomy of Malicious Singularities

abstract:
  As well known, the b-boundaries of the closed Friedman world model and of
Schwarzschild solution consist of a single point. We study this phenomenon in a
broader context of differential and structured spaces. We show that it is an
equivalence relation $\rho $, defined on the Cauchy completed total space
$\bar{E}$ of the frame bundle over a given space-time, that is responsible for
this pathology. A singularity is called malicious if the equivalence class
$[p_0]$ related to the singularity remains in close contact with all other
equivalence classes, i.e., if $p_0 \in \mathrm{cl}[p]$ for every $p \in E$. We
formulate conditions for which such a situation occurs. The differential
structure of any space-time with malicious singularities consists only of
constant functions which means that, from the topological point of view,
everything collapses to a single point. It was noncommutative geometry that was
especially devised to deal with such situations. A noncommutative algebra on
$\bar{E}$, which turns out to be a von Neumann algebra of random operators,
allows us to study probabilistic properties (in a generalized sense) of
malicious singularities. Our main result is that, in the noncommutative regime,
even the strongest singularities are probabilistically irrelevant.


title:
Spatially resolved THz response as a characterization concept for
  nanowire FETs

abstract:
  In this paper, we propose a THz probe technique to obtain spatially resolved
information about the electronic spectra inside nanowire-based FETs. This
spectroscopic approach employs a segmented multi-gate design for the local
detection of quantum transitions between few-electron states within the FET
channel. We simulate the intra-band THz response of such devices by means of a
many-body quantum approach, taking quantization and Coulomb interaction effects
into account. The obtained simulation results demonstrate the capabilities of
the proposed technique which go beyond the limitations of standard
characterization methods.


title: Generalized Banach contraction in probabilistic metric/normed spaces

abstract:
  In this paper, we present the generalization of B-contraction and
C-contraction due to Sehgal and Hicks respectively. We also study some
properties of C-contraction in probabilistic metric space.


title:
Regularization by free additive convolution, square and rectangular
  cases

abstract:
  The free convolution is the binary operation on the set of probability
measures on the real line which allows to deduce, from the individual spectral
distributions, the spectral distribution of a sum of independent unitarily
invariant square random matrices or of a sum of free operators in a non
commutative probability space. In the same way, the rectangular free
convolution allows to deduce, from the individual singular distributions, the
singular distribution of a sum of independent unitarily invariant rectangular
random matrices. In this paper, we consider the regularization properties of
these free convolutions on the whole real line. More specifically, we try to
find continuous semigroups $(\mu_t)$ of probability measures such that $\mu_0$
is the Dirac mass at zero and such that for all positive $t$ and all
probability measure $\nu$, the free convolution of $\mu_t$ with $\nu$ (or, in
the rectangular context, the rectangular free convolution of $\mu_t$ with
$\nu$) is absolutely continuous with respect to the Lebesgue measure, with a
positive analytic density on the whole real line. In the square case, we prove
that in semigroups satisfying this property, no measure can have a finite
second moment, and we give a sufficient condition on semigroups to satisfy this
property, with examples. In the rectangular case, we prove that in most cases,
for $\mu$ in a continuous rectangular-convolution-semigroup, the rectangular
convolution of $\mu$ with $\nu$ either has an atom at the origin or doesn't put
any mass in a neighborhood of the origin, thus the expected property does not
hold. However, we give sufficient conditions for analyticity of the density of
the rectangular convolution of $\mu$ with $\nu$ except on a negligible set of
points, as well as existence and continuity of a density everywhere.


title:
Asymptotic form of molecular continuum wave function for system of
  non-overlapping atomic potentials

abstract:
  The asymptotic behavior of the molecular continuum wave function has been
analyzed within a model of non-overlapping atomic potentials. It is been shown
that the representation of the wave function far from a molecule as a plane
wave and single spherical wave emitted by the molecular center cannot be
corrected. Because of the multicenter character of the problem, the asymptotic
form of the wave function must contain N spherical waves with centers at the
nuclei of the N atoms that form the molecule. A method of partial waves for a
spherically non-symmetrical target is considered for the simplest multicenter
target formed by two non-overlapping potentials. The results are compared with
those obtained within the single spherical wave approximation. It has been
shown that the use of this approximation results in significant mistakes in
differential and total cross sections of electron elastic scattering by a
target.


title: On electromagnetic contributions in WIMP quests

abstract:
  The effect pointed out by A. B. Migdal in the 40's (hereafter named Migdal
effect) has so far been usually neglected in the direct searches for WIMP Dark
Matter candidates. This effect consists in the ionization and the excitation of
bound atomic electrons induced by the recoiling atomic nucleus. In the present
paper the related theoretical arguments are developed and some consequences of
the proper accounting for this effect are discussed by some examples of
practical interest.


title:
Inverse Conductivity Problem for a Parabolic Equation using a Carlemen
  Estimate with one Observation

abstract:
  For the heat equation in a bounded domain we give a stability result for a
smooth diffusion coefficient. The key ingredients are a global Carleman-type
estimate, a Poincar\'e-type estimate and an energy estimate with a single
observation acting on a part of the boundary.


title:
Spiral phases and two-particle bound states from a systematic low-energy
  effective theory for magnons, electrons, and holes in an antiferromagnet

abstract:
  We have constructed a systematic low-energy effective theory for hole- and
electron-doped antiferromagnets, where holes reside in momentum space pockets
centered at $(\pm\frac{\pi}{2a},\pm\frac{\pi}{2a})$ and where electrons live in
pockets centered at $(\frac{\pi}{a},0)$ or $(0,\frac{\pi}{a})$. The effective
theory is used to investigate the magnon-mediated binding between two holes or
two electrons in an otherwise undoped system. We derive the one-magnon exchange
potential from the effective theory and then solve the corresponding
two-quasiparticle Schr\"odinger equation. As a result, we find bound state wave
functions that resemble $d_{x^2-y^2}$-like or $d_{xy}$-like symmetry. We also
study possible ground states of lightly doped antiferromagnets.


title: Theory of antibound states in partially filled narrow band systems

abstract:
  We present a theory of the dynamical two-particle response function in the
Hubbard model based on the time-dependent Gutzwiller approximation. The results
are in excellent agreement with exact diagonalization on small clusters and
give reliable results even for high densities, where the usual ladder
approximation breaks down. We apply the theory to the computation of antibound
states relevant for Auger spectroscopy and cold atom physics. A special bonus
of the theory is its computational simplicity.


title: Combined Effect of Bond- and Potential-Disorder in Half-Doped Manganites

abstract:
  We analyze the effects of both bond- and potential-disorder in the vicinity
of a first-order metal insulator transition in a two-band model for manganites
using a real-space Monte Carlo method. Our results reveal a novel
charge-ordered state coexisting with spin-glass behavior. We provide the basis
for understanding the phase diagrams of half-doped manganites, and contrast the
effects of bond- and potential-disorder and the combination of both.


title: Is Sr2RuO4 a triplet superconductor?

abstract:
  The field dependence of the specific heat \gamma(H) at lower temperatures in
Sr2RuO4 is analyzed by solving microscopic Eilenberger equation numerically. We
find that systematic \gamma(H) behaviors from a concaved \sqrt H to a convex
H^{\alpha} (\alpha>1) under H orientation change are understood by taking
account of the Pauli paramagnetic effect. The magnetizations are shown to be
consistent with it. This implies either a singlet pairing or a triplet one with
d-vector locked in the basal plane, which allows us to explain other mysteries
of this compound in a consistent way.


title: Estimating the annihilation decay B_s -> rho gamma with factorization

abstract:
  The branching ratio for the rare two-body B_s -> rho gamma decay is
calculated using the factorization assumption. This transition is dominated by
the annihilation diagrams and, in principle, prone to receiving substantial
contributions from new physics. We estimate Br(B_s -> rho gamma) = 1.6 x 10^-9
within the Standard Model and investigate the sensitivity of this decay mode to
the effects of two new physics scenarios: vector quark model and supersymmetry.
Our results indicate that the shift in branching ratio is at most around 10%
with the addition of vector quarks and is negligibly small in the constrained
minimal supersymmetric extension of the Standard Model.


title: SILEM : a new gaseous detector with integrated x-y readout plane

abstract:
  This works reports on gaseous detectors developments made in the frame of the
EXO double-beta decay experiment. LEM (Large Electron Multiplication) are
electron amplification grids based on GEM. They were developed in Neuchatel and
showed remarquable resistance to sparks. The new SILEM grid combines the
properties of the standard LEM with a micropatterned x-y readout plane on one
of the grid side. It allows thus the amplification of the primary electrons and
their position determination in the x-y plane.


title: Q-Ball Condensation

abstract:
  Q-balls arise in particle theories with U(1) global symmetry. The coupling of
the corresponding scalar field to fermions leads to Q-ball evaporation. In this
paper we consider the oposite problem, the case where a Q-ball absorbs
particles to grow. In particular we shall use the exact quantum mechanical
description of fermions interacting with a Q-ball to solve the problem. Results
show that Q-ball condensation can be another mechanism for Q-ball creation.


title:
Arc-like distribution of high CO(J=3-2)/CO(J=1-0) ratio gas surrounding
  the central star cluster of the supergiant HII region NGC 604

abstract:
  We report the discovery of a high CO(J=3-2)/CO(J=1-0) ratio gas with an
arc-like distribution (``high-ratio gas arc'') surrounding the central star
cluster of the supergiant HII region NGC 604 in the nearby spiral galaxy M 33,
based on multi-J CO observations of a 5' $\times$ 5' region of NGC 604
conducted using the ASTE 10-m and NRO 45-m telescopes. The discovered
``high-ratio gas arc'' extends to the south-east to north-west direction with a
size of $\sim$ 200 pc. The western part of the high-ratio gas arc closely
coincides well with the shells of the HII regions traced by H$\alpha$ and radio
continuum peaks. The CO(J=3-2)/CO(J=1-0) ratio, R_{3-2/1-0}, ranges between 0.3
and 1.2 in the observed region, and the R_{3-2/1-0} values of the high-ratio
gas arc are around or higher than unity, indicating very warm (T_kin > 60 K)
and dense (n(H_2) > 10^{3-4} cm^{-3}) conditions of the high-ratio gas arc. We
suggest that the dense gas formation and second-generation star formation occur
in the surrounding gas compressed by the stellar wind and/or supernova of the
first-generation stars of NGC 604, i.e., the central star cluster of NGC 604.


title: Observation of squeezed light with 10dB quantum noise reduction

abstract:
  Squeezing of light's quantum noise requires temporal rearranging of photons.
This again corresponds to creation of quantum correlations between individual
photons. Squeezed light is a non-classical manifestation of light with great
potential in high-precision quantum measurements, for example in the detection
of gravitational waves. Equally promising applications have been proposed in
quantum communication. However, after 20 years of intensive research doubts
arose whether strong squeezing can ever be realized as required for eminent
applications. Here we show experimentally that strong squeezing of light's
quantum noise is possible. We reached a benchmark squeezing factor of 10 in
power (10dB). Thorough analysis reveals that even higher squeezing factors will
be feasible in our setup.


title: Reconstruction of 5D Cosmological Model From Recent Observations

abstract:
  We use a parameterized equation of state (EOS) of dark energy to a 5D
Ricci-flat cosmological solution and suppose the universe contains two major
components: dark matter and dark energy. Using the recent observational
datasets: the latest 182 type Ia Supernovae Gold data, the 3-year WMAP CMB
shift parameter and the SDSS baryon acoustic peak, we obtain the best fit
values of the EOS and two major components' evolution. We find that the best
fit EOS crossing -1 in the near past $z\simeq 0.07$, the present best fit value
of $w_x(0)<-1$ and for this model the universe experiences the acceleration at
about $z\simeq 0.5$.


title:
IGR J00234+6141 : a new INTEGRAL source identified as an Intermediate
  polar

abstract:
  Following an extensive survey of the galactic plane by the INTEGRAL
satellite, new hard X-ray sources are discovered with a significant fraction of
Cataclysmic Variables (CVs) among them. We report here the identification of
one of these hard X-ray sources, IGR J00234+6141, as an accreting magnetic
white dwarf of intermediate polar type. We analyse the high energy emission of
the INTEGRAL source using all available data and provide complementary optical
photometric and spectroscopic data obtained respectively in August and October
2006. Based on a refined INTEGRAL position, we confirm the proposed optical
identification. We clearly detect the presence of a 564 s periodic optical
modulation that we identify as the rotation of the white dwarf. The analysis of
the optical spectrum also demonstrates that the emission lines show a
modulation in radial velocity with an orbital period of Porb = (4.033 +/-
0.005) hr. The two periodicities indicate that IGR00234+6141 is a magnetic CV
of the intermediate polar type. This is one of the faintest and hardest sources
of this type detected by INTEGRAL. This confirms earlier conclusions that IPs
contribute significantly to the population of galactic X-ray sources and
represent a significant fraction of the high energy background.


title:
Nonlinear Dynamics of Infectious Diseases Transfer with Possible
  Applications for Tubercular Infection

abstract:
  In this paper, we model a nonlinear dynamics of infectious diseases transfer.
Particularly, we study possible applications to tubercular infection in models
with different profiles (peak values) of the population density dependence on
spatial coordinates. Our approach is based on the well known method of
instantons which has been used by the authors to describe kinetics of adiabatic
chemical reactions as a function of the heat-bath temperature and other system
parameters. In our approach, we use "social temperature" T as one of the
controlling parameters. Increase of T leads to acceleration of the infectious
diseases transfer. The "blockage" effect for the infectious diseases transfer
has been demonstrated in the case when peak values (in the population density)
are equal to one and under condition that the "social temperature" is low.
Existence of such effect essentially depends from environment "activity"
(social and prophylactic). Results of our modeling qualitatively meet the
tuberculosis dynamic spread data in Penza region of Russia.


title: A Critical String Theory in 3+1 Dimensions

abstract:
  Redefining the vacuum state of a free twofold N=1 covariant supersymmetric
string action as the one with all the world sheet fermionic excited states
occupied, makes the theory anomaly free in D=4 with Minkowski signature. The
theory thus describes a critical string in 3+1 dimensions as opposed to earlier
N=2 supersymmetric theories describing a 2+2 dimensional target space. While in
the NS sector the spectrum basically resembles the same for the standard N=1
superstring theory with one of the $N$ species in the background, in the R
sector both the species of fermions and superconformal ghosts are required to
describe the relevant spin operators to describe the fermion spectra. A crucial
difference from D=10 case is that the fermion states are Dirac particles
instead of Majorana-Weyl. Even though the full spectrum of the theory contains
both bosons and fermions of various spin, there is no space-time supersymmetry
due to obvious lack of triality.


title: Hybrid inflation followed by modular inflation

abstract:
  Inflationary models with a superheavy scale F-term hybrid inflation followed
by an intermediate scale modular inflation are considered. The restrictions on
the power spectrum P_R of curvature perturbation and the spectral index n_s
from the recent data within the power-law cosmological model with cold dark
matter and a cosmological constant can be met provided that the number of
e-foldings N_HI* suffered by the pivot scale k_*=0.002/Mpc during hybrid
inflation is suitably restricted. The additional e-foldings needed for solving
the horizon and flatness problems are generated by modular inflation with a
string axion as inflaton. For central values of P_R and n_s, the grand
unification scale comes out, in the case of standard hybrid inflation, close to
its supersymmetric value M_GUT=2.86 x 10^16 GeV, the relevant coupling constant
is relatively large (0.005-0.14), and N_HI* is between 10 and 21.7. In the
shifted [smooth] hybrid inflation case, the grand unification scale can be
identified with M_GUT for N_HI*=21 [N_HI*=18].


title: Spiking Optical Patterns and Synchronization

abstract:
  We analyze the time resolved spike statistics of a solitary and two mutually
interacting chaotic semiconductor lasers whose chaos is characterized by
apparently random, short intensity spikes. Repulsion between two successive
spikes is observed, resulting in a refractory period which is largest at laser
threshold. For time intervals between spikes greater than the refractory
period, the distribution of the intervals follows a Poisson distribution. The
spiking pattern is highly periodic over time windows corresponding to the
optical length of the external cavity, with a slow change of the spiking
pattern as time increases. When zero-lag synchronization between the two lasers
is established, the statistics of the nearly perfectly matched spikes are not
altered. The similarity of these features to those found in complex interacting
neural networks, suggests the use of laser systems as simpler physical models
for neural networks.


title: 3-quasi-Sasakian manifolds

abstract:
  In the present paper we carry on a systematic study of 3-quasi-Sasakian
manifolds. In particular we prove that the three Reeb vector fields generate an
involutive distribution determining a canonical totally geodesic and Riemannian
foliation. Locally, the leaves of this foliation turn out to be Lie groups:
either the orthogonal group or an abelian one. We show that 3-quasi-Sasakian
manifolds have a well-defined rank, obtaining a rank-based classification.
Furthermore, we prove a splitting theorem for these manifolds assuming the
integrability of one of the almost product structures. Finally, we show that
the vertical distribution is a minimum of the corrected energy.


title: The plasmon Talbot effect

abstract:
  The plasmon analog of the self-imaging Talbot effect is described and
theoretically analyzed. Rich plasmon carpets containing hot spots are shown to
be produced by a row of periodically-spaced surface features. A row of holes
drilled in a metal film and illuminated from the back side is discussed as a
realizable implementation of this concept. Self-images of the row are produced,
separated from the original one by distances up to several hundreds of
wavelengths in the examples under consideration. The size of the image focal
spots is close to half a wavelength and the spot positions can be controlled by
changing the incidence direction of external illumination, suggesting the
possibility of using this effect (and its extension to non-periodic surface
features) for far-field patterning and for long-distance plasmon-based
interconnects in plasmonic circuits, energy transfer, and related phenomena.


title:
One loop renormalization of the non-local gauge invariant operator min_U
  (A^U_mu)^2 in QCD

abstract:
  We compute the one loop anomalous dimension of the gauge invariant dimension
two operator min_U (A^U_mu)^2, where U is an element of the gauge group, by
exploiting Zwanziger's expansion of the operator in terms of gauge invariant
non-local n leg operators. The computation is performed in an arbitrary linear
covariant gauge and the cancellation of the gauge parameter in the final
anomalous dimension is demonstrated explicitly. The result is equivalent to the
one loop anomalous dimension of the local dimension two operator (A^a_mu)^2 in
the Landau gauge.


title: On Shadow of the Moon in Extensive Air Shower Data

abstract:
  A new technique has been devised for the analysis of extensive air shower
data in observing the effect of the moon on this data. In this technique the
number of EAS events with arrival directions falling in error circles centered
about the moving moon is compared to the mean number of events falling in error
circles with centers randomly chosen in the sky. For any assumed angular radius
of the error circle the deficit in EAS event count in the direction of moon
i.e., Nsky-Nmoon which is a moon-related effect is interpreted as the shadow of
the moon. A simple theoretical model has been developed to relate Nsky to the
angular radius of the error circle and has been applied to the counts from the
moon's direction in order to extract the physical parameters of the shadow of
the moon. The technique and the theoretical model has been used on 1.7 *10^5
EAS events recorded at Alborz observatory.


title: Searching for New Physics in Future Neutrino Factory Experiments

abstract:
  An extension of the New Standard Model, by introducing a mixing of the low
mass ``active'' neutrinos with heavy ones, or by any model with lepton flavor
violation, is considered. This leads to non-orthogonal neutrino production and
detection states and to modifications of neutrino oscillations in both, vacuum
and matter. The possibility of the discovery of such effects in current and
future neutrino oscillation experiments is discussed. First order approximation
formulas for the flavor transition probabilities in constant density matter,
for all experimentally available channels, are given. Numerical calculations of
flavor transition probabilities for two sets of New Physics parameters
describing a single ``effective'' heavy neutrino state, both satisfying present
experimental constraints, have been performed. Two energy ranges and several
baselines, assuming both the current ($\pm2\sigma$) and the expected in future
($\pm3%$) errors of the neutrino oscillation parameters are considered, keeping
their present central values. It appears that the biggest potential of the
discovery of the possible presence of any New Physics is pronounced in
oscillation channels in which $\nu_{e}$, $\nu_{\bar{e}}$ are not involved at
all, especially for two baselines, $L=3000 km$ and $L=7500 km$, which for other
reasons are also called ``magic'' for future $Neutrino Factory$ experiments.


title: Spin chain from membrane and the Neumann-Rosochatius integrable system

abstract:
  We find membrane configurations in AdS_4 x S^7, which correspond to the
continuous limit of the SU(2) integrable spin chain, considered as a limit of
the SU(3) spin chain, arising in N=4 SYM in four dimensions, dual to strings in
AdS_5 x S^5. We also discuss the relationship with the Neumann-Rosochatius
integrable system at the level of Lagrangians, comparing the string and
membrane cases.


title: Representations of tame quivers and affine canonical bases

abstract:
  An integral PBW-basis of type $A_1^{(1)}$ has been constructed by Zhang [Z]
and Chen [C] using the Auslander-Reiten quiver of the Kronecker quiver. We
associate a geometric order to elements in this basis following an idea of
Lusztig [L1] in the case of finite type. This leads to an algebraic realization
of a bar-invariant basis of $\uq2$. For any affine symmetric type, we obtain an
integral PBW-basis of the generic composition algebra, by using an algebraic
construction of the integral basis for a tube in [DDX], an embedding of the
module category of the Kronecker quiver into the module category of the tame
quiver, and a list of the root vectors of indecomposable modules according to
the preprojective, regular, and preinjective components of the Auslander-Reiten
quiver of the tame quiver. When the basis elements are ordered to be compatible
with the geometric order given by the dimensions of the orbit varieties and the
extension varieties, we can show that the transition matrix between the
PBW-basis and a monomial basis is triangular with diagonal entries equal to 1.
Therefore we obtain a bar-invariant basis. By a orthogonalization for the
PBW-basis with the inner product, we finally give an algebraic way to realize
the canonical bases of the quantized enveloping algebras of all symmetric
affine Kac-Moody Lie algebras.


title:
Form factors in finite volume I: form factor bootstrap and truncated
  conformal space

abstract:
  We describe the volume dependence of matrix elements of local fields to all
orders in inverse powers of the volume (i.e. only neglecting contributions that
decay exponentially with volume). Using the scaling Lee-Yang model and the
Ising model in a magnetic field as testing ground, we compare them to matrix
elements extracted in finite volume using truncated conformal space approach to
exact form factors obtained using the bootstrap method. We obtain solid
confirmation for the form factor bootstrap, which is different from all
previously available tests in that it is a non-perturbative and direct
comparison of exact form factors to multi-particle matrix elements of local
operators, computed from the Hamiltonian formulation of the quantum field
theory. We also demonstrate that combining form factor bootstrap and truncated
conformal space is an effective method for evaluating finite volume form
factors in integrable field theories over the whole range in volume.


title: Non-forward Balitsky-Kovchegov equation and Vector Mesons

abstract:
  Considering the Balitsky-Kovchegov QCD evolution equation in full momentum
space, we derive the travelling wave solutions expressing the nonlinear
saturation constraints on the dipole scattering amplitude at non-zero momentum
transfer. A phenomenological application to elastic vector meson production
shows the compatibility of data with the QCD prediction: an enhanced saturation
scale at intermediate momentum transfer.


title: Star clusters as diaries of galaxies

abstract:
  Most if not all stars form in star clusters. Thus the distribution of star
clusters preserves the information on the star formation history of a galaxy.
Massive clusters form only during episodes of high star formation activity
whereas periods of low star formation activity cannot produce them. We present
here the method of Maschberger & Kroupa (2007) to derive the star formation
history of a galaxy from its star-cluster content.


title: Rational points on certain hyperelliptic curves over finite fields

abstract:
  Let $K$ be a field, $a, b\in K$ and $ab\neq 0$. Let us consider the
polynomials $g_{1}(x)=x^n+ax+b, g_{2}(x)=x^n+ax^2+bx$, where $n$ is a fixed
positive integer. In this paper we show that for each $k\geq 2$ the
hypersurface given by the equation \begin{equation*} S_{k}^{i}:
u^2=\prod_{j=1}^{k}g_{i}(x_{j}),\quad i=1, 2. \end{equation*} contains a
rational curve. Using the above and Woestijne's recent results \cite{Woe} we
show how one can construct a rational point different from the point at
infinity on the curves $C_{i}:y^2=g_{i}(x), (i=1, 2)$ defined over a finite
field, in polynomial time.


title:
Detector dead-time effects and paralyzability in high-speed quantum key
  distribution

abstract:
  Recent advances in quantum key distribution (QKD) have given rise to systems
that operate at transmission periods significantly shorter than the dead times
of their component single-photon detectors. As systems continue to increase in
transmission rate, security concerns associated with detector dead times can
limit the production rate of sifted bits. We present a model of high-speed QKD
in this limit that identifies an optimum transmission rate for a system with
given link loss and detector response characteristics.


title: Nuclei embedded in an electron gas

abstract:
  The properties of nuclei embedded in an electron gas are studied within the
relativistic mean-field approach. These studies are relevant for nuclear
properties in astrophysical environments such as neutron-star crusts and
supernova explosions. The electron gas is treated as a constant background in
the Wigner-Seitz cell approximation. We investigate the stability of nuclei
with respect to alpha and beta decay. Furthermore, the influence of the
electronic background on spontaneous fission of heavy and superheavy nuclei is
analyzed. We find that the presence of the electrons leads to stabilizing
effects for both $\alpha$ decay and spontaneous fission for high electron
densities. Furthermore, the screening effect shifts the proton dripline to more
proton-rich nuclei, and the stability line with respect to beta decay is
shifted to more neutron-rich nuclei. Implications for the creation and survival
of very heavy nuclear systems are discussed.


title: Spin Injection into a Graphene Thin Film at Room Temperature

abstract:
  We demonstrate spin injection into a graphene thin film with high reliability
by using non-local magnetoresistance (MR) measurements, in which the electric
current path is completely separated from the spin current path. Using these
non-local measurements, an obvious MR effect was observed at room temperature;
and the MR effect was ascribed to magnetization reversal of ferromagnetic
electrodes. This result is a direct demonstration of spin injection into a
graphene thin film. Furthermore, this is the first report of spin injection
into molecules at room temperature.


title:
Reconstructing vibrational states in warm molecules using four-wave
  mixing with femtosecond laser pulses

abstract:
  We propose a method to reconstruct the vibrational quantum state of molecules
excited by a general excitation laser pulse. Unlike existing methods, we do not
require the molecules before excitation to be in a pure state, allowing us to
treat the important case of initially thermally excited molecules. Even if only
a single initial level is appreciably populated, initial levels with small
populations can still give major contributions to the unknown vibrational
state, making it essential to take them into account. In addition to the
excitation pulse, the method uses two incident, short laser pulses in a
non-co-linear geometry to create four-wave mixing in the molecules. The
measurements used in the reconstruction are spectra of the outgoing four-wave
mixing pulse at different time delays of the excitation laser pulse. An
important point is that the method does not require detailed knowledge of
molecular transition moments between excited states nor of any of the incoming
laser pulses, but circumvents this requirement by using one or more calibration
laser pulses in a separate experiment either before or after the main data are
recorded. The only requirements for the calibration laser pulses are that the
constant parts of their spectrums should together cover the spectral range of
the excitation laser pulse, and the constant part of each should have
sufficient spectral overlap with one other calibration pulse to populate two of
the same levels. Finally, we discuss the extension of the reconstruction method
in this paper to more general situations, hereby presenting the new idea of
quantum state reconstruction through perturbations with calibration.


title:
The crucial importance of the $t_{2g}$--$e_g$ hybridization in
  transition metal oxides

abstract:
  We studied the influence of the trigonal distortion of the regular octahedron
along the (111) direction, found in the $\rm CoO_2$ layers. Under such a
distortion the $t_{2g}$ orbitals split into one $a_{1g}$ and two degenerated
$e_g^\prime$ orbitals. We focused on the relative order of these orbitals.
Using quantum chemical calculations of embedded clusters at different levels of
theory, we analyzed the influence of the different effects not taken into
account in the crystalline field theory; that is metal-ligand hybridization,
long-range crystalline field, screening effects and orbital relaxation. We
found that none of them are responsible for the relative order of the $t_{2g}$
orbitals. In fact, the trigonal distortion allows a mixing of the $t_{2g}$ and
$e_g$ orbitals of the metallic atom. This hybridization is at the origin of the
$a_{1g}$--$e_g^\prime$ relative order and of the incorrect prediction of the
crystalline field theory.


title:
Heterogeneity and Increasing Returns May Drive Socio-Economic
  Transitions

abstract:
  There are clear benefits associated with a particular consumer choice for
many current markets. For example, as we consider here, some products might
carry environmental or `green' benefits. Some consumers might value these
benefits while others do not. However, as evidenced by myriad failed attempts
of environmental products to maintain even a niche market, such benefits do not
necessarily outweigh the extra purchasing cost. The question we pose is, how
can such an initially economically-disadvantaged green product evolve to hold
the greater share of the market? We present a simple mathematical model for the
dynamics of product competition in a heterogeneous consumer population. Our
model preassigns a hierarchy to the products, which designates the consumer
choice when prices are comparable, while prices are dynamically rescaled to
reflect increasing returns to scale. Our approach allows us to model many
scenarios of technology substitution and provides a method for generalizing
market forces. With this model, we begin to forecast irreversible trends
associated with consumer dynamics as well as policies that could be made to
influence transitions


title:
Geometrical locus of massive test particle orbits in the space of
  physical parameters in Kerr space-time

abstract:
  Gravitational radiation of binary systems can be studied by using the
adiabatic approximation in General Relativity. In this approach a small
astrophysical object follows a trajectory consisting of a chained series of
bounded geodesics (orbits) in the outer region of a Kerr Black Hole,
representing the space time created by a bigger object. In our paper we study
the entire class of orbits, both of constant radius (spherical orbits), as well
as non-null eccentricity orbits, showing a number of properties on the physical
parameters and trajectories. The main result is the determination of the
geometrical locus of all the orbits in the space of physical parameters in Kerr
space-time. This becomes a powerful tool to know if different orbits can be
connected by a continuous change of their physical parameters. A discussion on
the influence of different values of the angular momentum of the hole is given.
Main results have been obtained by analytical methods.


title: A Generic Model of Contracts for Embedded Systems

abstract:
  We present the mathematical foundations of the contract-based model developed
in the framework of the SPEEDS project. SPEEDS aims at developing methods and
tools to support "speculative design", a design methodology in which
distributed designers develop different aspects of the overall system, in a
concurrent but controlled way. Our generic mathematical model of contract
supports this style of development. This is achieved by focusing on behaviors,
by supporting the notion of "rich component" where diverse (functional and
non-functional) aspects of the system can be considered and combined, by
representing rich components via their set of associated contracts, and by
formalizing the whole process of component composition.


title: Universality of traveling waves with QCD running coupling

abstract:
  ``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio
Q/Q_S, where Q_S(Y) is the rapidity-dependent \saturation scale, can be
theoretically obtained from universal ``traveling wave'' solutions of the
nonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We
examine the similar mean-field predictions beyond leading-logarithmic order,
including running QCD coupling.


title:
Impurity scattering in strongly correlated metals close to the Mott
  transition

abstract:
  This work explores a simple approximation to describe isolated impurity
scattering in a strongly correlated metal. The approximation combines
conventional one electron scattering theory and the Dynamic Mean Field Theory
to describe strong correlations in the host. It becomes exact in several
limits, including those of very weak and very strong impurity potentials.
Original electronic structure appears at the impurity site when the impurity
potential strength is moderate and the host is close to the Mott transition.
Our results may provide useful guidance for interpretation of scanning
tunneling microscopy experiments in strongly correlated systems.


title: Transversity Signals in Two-Hadron Production at COMPASS

abstract:
  New results on single spin asymmetries of identified charged pion and kaon
pairs produced in deep-inelastic scattering of muons on a transversely
polarized 6LiD target are presented. The data were taken in the years 2003 and
2004 with the COMPASS spectrometer at CERN with a 160 GeV muon beam from the
CERN SPS accelerator. The asymmetries can be interpreted in the context of
transversity as a convolution of the chiral-odd interference fragmentation
function $H_1^\sphericalangle$ with the transverse spin distribution of quarks
$\Delta_Tq(x)$. The measured azimuthal target spin asymmetries on the deuteron
are compatible with zero within a small statistical error of about 1%.


title: Uncertainty in the Fluctuations of the Price of Stocks

abstract:
  We report on a study of the Tehran Price Index (TEPIX) from 2001 to 2006 as
an emerging market that has been affected by several political crises during
the recent years, and analyze the non-Gaussian probability density function
(PDF) of the log returns of the stocks' prices. We show that while the average
of the index did not fall very much over the time period of the study, its
day-to-day fluctuations strongly increased due to the crises. Using an approach
based on multiplicative processes with a detrending procedure, we study the
scale-dependence of the non-Gaussian PDFs, and show that the temporal
dependence of their tails indicates a gradual and systematic increase in the
probability of the appearance of large increments in the returns on approaching
distinct critical time scales over which the TEPIX has exhibited maximum
uncertainty.


title: Gap solitons in spatiotemporal photonic crystals

abstract:
  We generalize the concept of nonlinear periodic structures to systems that
show arbitrary spacetime variations of the refractive index. Nonlinear pulse
propagation through these spatiotemporal photonic crystals can be described,
for shallow nonstationary gratings, by coupled mode equations which are a
generalization of the traditional equations used for stationary photonic
crystals. Novel gap soliton solutions are found by solving a modified massive
Thirring model. They represent the missing link between the gap solitons in
static photonic crystals and resonance solitons found in dynamic gratings.


title:
MiniBooNE Results and Neutrino Schemes with 2 sterile Neutrinos:
  Possible Mass Orderings and Observables related to Neutrino Masses

abstract:
  The MiniBooNE and LSND experiments are compatible with each other when two
sterile neutrinos are added to the three active ones. In this case there are
eight possible mass orderings. In two of them both sterile neutrinos are
heavier than the three active ones. In the next two scenarios both sterile
neutrinos are lighter than the three active ones. The remaining four scenarios
have one sterile neutrino heavier and another lighter than the three active
ones. We analyze all scenarios with respect to their predictions for
mass-related observables. These are the sum of neutrino masses as constrained
by cosmological observations, the kinematic mass parameter as measurable in the
KATRIN experiment, and the effective mass governing neutrinoless double beta
decay. It is investigated how these non-oscillation probes can distinguish
between the eight scenarios. Six of the eight possible mass orderings predict
positive signals in the KATRIN and future neutrinoless double beta decay
experiments. We also remark on scenarios with three sterile neutrinos. In
addition we make some comments on the possibility of using decays of high
energy astrophysical neutrinos to discriminate between the mass orderings in
presence of two sterile neutrinos.


title: Nernst Effect in NdBa_2[Cu_{1-y}Ni_y]_3O_{7-\delta}

abstract:
  In NdBa_2[Cu_{1-y}Ni_y]_3O_{7-\delta}, magnetic Ni-impurities suppress Tc but
at the same time the pseudogap is strongly enhanced. This unique feature makes
it an ideal system to study possible relations between the anomalous Nernst
effect, superconductivity and the pseudogap. We present Nernst effect
measurements on a series of optimally doped (O_7) and underdoped (O_{6.8})
samples with Ni contents ranging from y=0 to 0.12. In all samples an onset of
the Nernst signal is found at T^\nu > Tc. For the optimally doped samples T^\nu
and Tc decrease simultaneously with increasing Ni content. The underdoped
samples show a different behavior, i.e. the onset of the Nernst signal is
hardly affected by increasing the Ni content from y=0 to 0.03. Irrespective of
the oxygen content, T^\nu clearly does not track the enhanced pseudogap
temperature T*.


title: Testing thermal reprocessing in AGN accretion discs

abstract:
  The thermal reprocessing hypothesis in AGN, where EUV/X-ray photons are
reprocessed by the accretion disc into optical/UV photons, predicts
wavelength-dependent time delays between the optical continuum at different
wavelengths. Recent photometric monitoring by Sergeev et al. has shown that the
time-delay is observed in 14 AGN, and generally seen to increase with
increasing wavelength, as predicted in the reprocessing scenario. We fit the
observed time delays and optical spectral energy distribution using a disc
reprocessing model. The model delivers estimates for the nuclear reddening, the
product of black hole mass times accretion rate, and the distance to each
object. However, the distances at face value give H_0 = 44 +/- 5 km/s/Mpc - a
factor of 1.6 smaller than generally accepted. We discuss the implications of
this on the reprocessing model.


title: Supercurrents in an atom-molecule gas in an optical ring lattice

abstract:
  Atom and molecule currents in a Fermi gas in the neighborhood of a Feshbach
resonance are studied in a one-dimensional optical ring lattice by directly
diagonalizing small models. A rotational analogy of flux quantization is used
to show that fraction of the current is carried by particles with twice the
mass of an atom, which suggests pairing and superfluidity.


title:
The absolute Galois group acts faithfully on the connected components of
  the moduli space of surfaces of general type

abstract:
  We show that the Galois group $Gal(\bar{\Q} /\Q)$ operates faithfully on the
set of connected components of the moduli spaces of surfaces of general type,
and also that for each element $\sigma \in Gal(\bar{\Q} /\Q)$ different from
the identity and from complex conjugation, there is a surface of general type
such that $X$ and the Galois conjugate variety $X^{\sigma}$ have nonisomorphic
fundamental groups. The result was announced by the second author at the
Alghero Conference 'Topology of algebraic varieties' in september 2006. Before
the present paper was actually written, we received a very interesting preprint
by Robert Easton and Ravi Vakil (\cite{e-v}), where it is proven, with a
completely different type of examples, that the Galois group $Gal(\bar{\Q}
/\Q)$ operates faithfully on the set of irreducible components of the moduli
spaces of surfaces of general type. We also give other simpler examples of
surfaces with nonisomorphic fundamental groups which are Galois conjugate,
hence have isomorphic algebraic fundamental groups.


title: The Quantum-Classical Transition and Wave Packet Dispersion

abstract:
  Two recent studies have presented new information relevant to the transition
from quantum behavior to classical behavior, and related this to parameters
characterizing the universe as a whole. The present study based on a separate
approach has developed similar results that appear to substantiate aspects of
earlier work and also to introduce further new ideas.