title: A widely tunable parametric amplifier based on a SQUID array resonator

abstract:
  We create a Josephson parametric amplifier from a transmission line resonator
whose inner conductor is made from a series SQUID array. By changing the
magnetic flux through the SQUID loops, we are able to adjust the circuit's
resonance frequency and, consenquently, the center of the amplified band,
between 4 and 7.8 GHz. We observe that the amplifier has gains as large as 28
dB and infer that it adds less than twice the input vacuum noise.


title: Line and Mean Opacities for Ultracool Dwarfs and Extrasolar Planets

abstract:
  Opacities and chemical abundance data are crucial ingredients of ultracool
dwarf and extrasolar giant planet atmosphere models. We report here on the
detailed sources of molecular opacity data employed by our group for this
application. We also present tables of Rosseland and Planck mean opacities
which are of use in some studies of the atmospheres, interiors, and evolution
of planets and brown dwarfs. For the tables presented here we have included the
opacities of important atomic and molecular species, including the alkali
elements, pressure induced absorption by hydrogen, and other significant
opacity sources but neglect opacity from condensates. We report for each
species how we have assembled molecular line data from a combination of public
databases, laboratory data that is not yet in the public databases, and our own
numerical calculations. We combine these opacities with abundances computed
from a chemical equilibrium model using recently revised solar abundances to
compute mean opacities. The chemical equilibrium calculation accounts for the
settling of condensates in a gravitational field, and is applicable to
ultracool dwarf and extrasolar planetary atmospheres, but not circumstellar
disks. We find that the inclusion of alkali atomic opacity substantially
increases the mean opacities over those currently in the literature at
densities relevant to the atmospheres and interiors of giant planets and brown
dwarfs. We provide our opacity tables for public use and discuss their
limitations.


title: Connecting LHC, ILC, and Quintessence

abstract:
  If the cold dark matter consists of weakly interacting massive particles
(WIMPs), anticipated measurements of the WIMP properties at the Large Hadron
Collider (LHC) and the International Linear Collider (ILC) will provide an
unprecedented experimental probe of cosmology at temperatures of order 1 GeV.
It is worth emphasizing that the expected outcome of these tests may or may not
be consistent with the picture of standard cosmology. For example, in
kination-dominated quintessence models of dark energy, the dark matter relic
abundance can be significantly enhanced compared to that obtained from freeze
out in a radiation-dominated universe. Collider measurements then will
simultaneously probe both dark matter and dark energy. In this article, we
investigate the precision to which the LHC and ILC can determine the dark
matter and dark energy parameters under those circumstances. We use an
illustrative set of four benchmark points in minimal supergravity in analogy
with the four LCC benchmark points. The precision achievable together at the
LHC and ILC is sufficient to discover kination-dominated quintessence, under
the assumption that the WIMPs are the only dark matter component. The LHC and
ILC can thus play important roles as alternative probes of both dark matter and
dark energy.


title:
Dynamical Masses for Pre-Main Sequence Stars: A Preliminary Physical
  Orbit for V773 Tau A

abstract:
  We report on interferometric and radial-velocity observations of the
double-lined 51-d period binary (A) component of the quadruple pre-main
sequence (PMS) system V773 Tau. With these observations we have estimated
preliminary visual and physical orbits of the V773 Tau A subsystem. Among other
parameters, our orbit model includes an inclination of 66.0 $\pm$ 2.4 deg, and
allows us to infer the component dynamical masses and system distance. In
particular we find component masses of 1.54 $\pm$ 0.14 and 1.332 $\pm$ 0.097
M$_{\sun}$ for the Aa (primary) and Ab (secondary) components respectively.
  Our modeling of the subsystem component spectral energy distributions finds
temperatures and luminosities consistent with previous studies, and coupled
with the component mass estimates allows for comparison with PMS stellar models
in the intermediate-mass range. We compare V773 Tau A component properties with
several popular solar-composition models for intermediate-mass PMS stars. All
models predict masses consistent to within 2-sigma of the dynamically
determined values, though some models predict values that are more consistent
than others.


title:
Collisional parton energy loss in a finite size QCD medium revisited:
  Off mass-shell effects

abstract:
  We study the collisional energy loss mechanism for particles produced off
mass-shell in a finite size QCD medium. The off mass-shell effects introduced
are to consider particles produced in wave packets instead of plane waves and
the length scale associated to an in-medium particles' life-time. We show that
these effects reduce the energy loss as compared to the case when the particles
are described as freely propagating from the source. The reduction of the
energy loss is stronger as this scale becomes of the order or smaller than the
medium size. We discuss possible consequences of the result on the description
of the energy loss process in the parton recombination scenario.


title: Geysers in the Lagoon: new Herbig-Haro objects in M8

abstract:
  Aims: We search for direct evidence of ongoing star formation by accretion in
the Lagoon Nebula (M8), using optical wide-field narrow-band imaging obtained
at La Silla Observatory.
  Methods: We examine [SII] and Halpha images for line-emission features that
could be interpreted as signatures of outflow activity of the exciting sources.
  Results: We discover five new Herbig-Haro objects, study in detail their
morphology and attempt to identify their potential driving sources among the
population of T Tauri stars and embedded sources in the surroundings.
  Conclusions: The results reported here conclusively demonstrate the existence
of very young stars going through the accreting phase in the M8 region.


title:
The Derivative Expansion of the Effective Action and the Renormalization
  Group Equation

abstract:
  The perturbative evaluation of the effective action can be expanded in powers
of derivatives of the external field. We apply the renormalization group
equation to the term in the effective action that is second order in the
derivatives of the external field and all orders in a constant external field,
considering both massless scalar $\phi_4^4$ model and massless scalar
electrodynamics. A so-called ``on shell'' renormalization scheme permits one to
express this ``kinetic term'' for the scalar field entirely in terms of the
renormalization group functions appropriate for this scheme. These
renormalization group functions can be related to those associated with minimal
subtraction.


title: Tightening of knots in proteins

abstract:
  We perform theoretical studies of stretching of 20 proteins with knots within
a coarse grained model. The knot's ends are found to jump to well defined
sequential locations that are associated with sharp turns whereas in
homopolymers they diffuse around and eventually slide off. The waiting times of
the jumps are increasingly stochastic as the temperature is raised. Larger
knots do not return to their native locations when a protein is released after
stretching.


title: Koszul duality in deformation quantization, I

abstract:
  Let $\alpha$ be a polynomial Poisson bivector on a finite-dimensional vector
space $V$ over $\mathbb{C}$. Then Kontsevich [K97] gives a formula for a
quantization $f\star g$ of the algebra $S(V)^*$. We give a construction of an
algebra with the PBW property defined from $\alpha$ by generators and
relations. Namely, we define an algebra as the quotient of the free tensor
algebra $T(V^*)$ by relations $x_i\otimes x_j-x_j\otimes x_i=R_{ij}(\hbar)$
where $R_{ij}(\hbar)\in T(V^*)\otimes\hbar \mathbb{C}[[\hbar]]$, $R_{ij}=\hbar
\Sym(\alpha_{ij})+\mathcal{O}(\hbar^2)$, with one relation for each pair of
$i,j=1...\dim V$. We prove that the constructed algebra obeys the PBW property,
and this is a generalization of the Poincar\'{e}-Birkhoff-Witt theorem. In the
case of a linear Poisson structure we get the PBW theorem itself, and for a
quadratic Poisson structure we get an object closely related to a quantum
$R$-matrix on $V$. At the same time we get a free resolution of the deformed
algebra (for an arbitrary $\alpha$).
  The construction of this PBW algebra is rather simple, as well as the proof
of the PBW property. The major efforts should be undertaken to prove the
conjecture that in this way we get an algebra isomorphic to the Kontsevich
star-algebra.


title:
A characteristic observable signature of preferred frame effects in
  relativistic binary pulsars

abstract:
  In this paper we develop a consistent, phenomenological methodology to
measure preferred-frame effects (PFEs) in binary pulsars that exhibit a high
rate of periastron advance. We show that in these systems the existence of a
preferred frame for gravity leads to an observable characteristic `signature'
in the timing data, which uniquely identifies this effect. We expand the
standard Damour-Deruelle timing formula to incorporate this `signature' and
show how this new PFE timing model can be used to either measure or constrain
the parameters related to a violation of the local Lorentz invariance of
gravity in the strong internal fields of neutron stars. In particular, we
demonstrate that in the presence of PFEs we expect a set of the new timing
parameters to have a unique relationship that can be measured and tested
incontrovertibly. This new methodology is applied to the Double Pulsar, which
turns out to be the ideal test system for this kind of experiments.The
currently available dataset allows us only to study the impact of PFEs on the
orbital precession rate, d omega/dt, providing limits that are, at the moment,
clearly less stringent than existing limits on PFE strong-field parameters.
However, simulations show that the constraints improve fast in the coming
years, allowing us to study all new PFE timing parameters and to check for the
unique relationship between them. Finally, we show how a combination of several
suitable systems in a "PFE antenna array", expected to be availabe for instance
with the Square-Kilometre-Array (SKA), provides full sensitivity to possible
violations of local Lorentz invariance in strong gravitational fields in all
directions of the sky. This PFE antenna array may eventually allow us to
determine the direction of a preferred frame should it exist.


title:
Allovalency revisited: an analysis of multisite phosphorylation and
  substrate rebinding

abstract:
  The utilization of multiple phosphorylation sites in regulating a biological
response is ubiquitous in cell signaling. If each site contributes an
additional, equivalent binding site, then one consequence of an increase in the
number of phosphorylations may be to increase the probability that, upon
disassociation, a ligand immediately rebinds to its receptor. How such effects
may influence cell signaling systems has been less studied. Here, a
self-consistent integral equation formalism for ligand rebinding, in
conjunction with Monte Carlo simulations, is employed to further investigate
the effects of multiple, equivalent binding sites on shaping biological
responses. Multiple regimes that characterize qualitatively different physics
due to the differential prevalence of rebinding effects are predicted.
Calculations suggest that when ligand rebinding contributes significantly to
the dose response, a purely allovalent model can influence the binding curves
nonlinearly. The model also predicts that ligand rebinding in itself appears
insufficient to generative a highly cooperative biological response.


title: Galois theory of iterated endomorphisms

abstract:
  Given an abelian algebraic group $A$ over a global field $F$, $\alpha \in
A(F)$, and a prime $\ell$, the set of all preimages of $\alpha$ under some
iterate of $[\ell]$ generates an extension of $F$ that contains all
$\ell$-power torsion points as well as a Kummer-type extension. We analyze the
Galois group of this extension, and for several classes of $A$ we give a simple
characterization of when the Galois group is as large as possible up to
constraints imposed by the endomorphism ring or the Weil pairing. This Galois
group encodes information about the density of primes $\p$ in the ring of
integers of $F$ such that the order of $(\alpha \bmod{\p})$ is prime to $\ell$.
We compute this density in the general case for several classes of $A$,
including elliptic curves and one-dimensional tori. For example, if $F$ is a
number field, $A/F$ is an elliptic curve with surjective 2-adic representation
and $\alpha \in A(F)$ with $\alpha \not\in 2A(F(A[4]))$, then the density of
$\mathfrak{p}$ with ($\alpha \bmod{\p}$) having odd order is 11/21.


title:
Dynamical ultrafast all-optical switching of planar GaAs/AlAs photonic
  microcavities

abstract:
  The authors study the ultrafast switching-on and -off of planar GaAs/AlAs
microcavities. Up to 0.8% refractive index changes are achieved by optically
exciting free carriers at 1720 nm and a pulse energy of 1.8 micro Joules. The
cavity resonance is dynamically tracked by measuring reflectivity versus time
delay with tunable laser pulses, and is found to shift by as much as 3.3
linewidths within a few picoseconds. The switching-off occurs with a decay time
of around 50 ps. The authors derive the dynamic behavior of the carrier density
and of the complex refractive index. They propose that the inferred 10 GHz
switching rate may be tenfold improved by optimized sample growth.


title:
The Scattering Polarization of the Sr I 4607 \AA Line at the Diffraction
  Limit Resolution of a 1-m Telescope

abstract:
  One of the greatest challenges in solar and stellar physics in coming years
will be to observe the Second Solar Spectrum with a spatial resolution
significantly better than 1 arcsec. This type of scattering polarization
observations would probably allow us to discover hitherto unknown aspects of
the Sun's hidden magnetism. Here we report on some theoretical predictions for
the photospheric line of Sr I at 4607 \AA, which we have obtained by solving
the three-dimensional (3D) radiative transfer problem of scattering line
polarization in a realistic hydrodynamical model of the solar photosphere. We
have taken into account not only the anisotropy of the radiation field in the
3D medium and the Hanle effect of a tangled magnetic field, but also the
symmetry breaking effects caused by the horizontal atmospheric inhomogeneities
produced by the solar surface convection. Interestingly, the Q/I and U/I linear
polarization signals of the emergent spectral line radiation have sizable
values and fluctuations, even at the very center of the solar disk where we
meet the forward scattering case. The ensuing small-scale patterns in Q/I and
U/I turn out to be sensitive to the assumed magnetic field model, and are of
great diagnostic value. We argue that it should be possible to observe them
with the help of a 1-m telescope equipped with adaptive optics and a suitable
polarimeter.


title: Fermi surface of CeIn3 above the Neel critical field

abstract:
  We report measurements of the de Haas-van Alphen effect in CeIn3 in magnetic
fields extending to ~90 T, well above the Ne'el critical field of Hc ~61 T. The
unreconstructed Fermi surface a-sheet is observed in the high magnetic field
polarized paramagnetic limit, but with its effective mass and Fermi surface
volume strongly reduced in size compared to that observed in the low magnetic
field paramagnetic regime under pressure. The spheroidal topology of this sheet
provides an ideal realization of the transformation from a `large Fermi
surface' accommodating f-electrons to a `small Fermi surface' when the
f-electron moments become polarized.


title:
Longitudinal Spin Measurements with Inclusive Hadrons in Polarized p+p
  Collisions at 200 GeV

abstract:
  We present measurements of the double longitudinal spin asymmetries for
inclusive pi0 and pi+(-) production in polarized p+p collisions at sqrt(s) =
200 GeV at mid-rapidity with the STAR detector from the 2005 RHIC run. These
measurements are used to access Delta G/G, the gluon polarization in the
proton. The observed unpolarized inclusive cross sections show good agreement
with NLO pQCD calculations. The double longitudinal spin asymmetries are
compared to NLO pQCD calculations based on different assumptions for the gluon
polarization in the nucleon to provide constraints on Delta G/G. At the present
level of statistics the measured asymmetries disfavor a large positive gluon
polarization, but cannot yet distinguish between other scenarios.


title: Models for microquasars

abstract:
  I review current models used to interpret the spectra and variability of
microquasars. Among other things, I discuss the structure of the accretion flow
and its dependence on mass accretion rate, the intrinsic connection between hot
comptonizing corona and compact radio jet in the hard state, as well as
possible models for the spectral hysteresis observed during outbursts of
transient sources. Finally I comment on several models for the non-poissonian
X-ray noise in black hole binaries which, at least in some instances, is
suspected to be associated with some form of coupling between disc and jet
activity.


title: Stochastic Parabolic Equations of Full Second Order

abstract:
  A procedure is described for defining a generalized solution for stochastic
differential equations using the Cameron-Martin version of the Wiener Chaos
expansion. Existence and uniqueness of this Wiener Chaos solution is
established for parabolic stochastic PDEs such that both the drift and the
diffusion operators are of the second order.


title:
From Random Processes to Generalized Fields: A Unified Approach to
  Stochastic Integration

abstract:
  The paper studies stochastic integration with respect to Gaussian processes
and fields. It is more convenient to work with a field than a process: by
definition, a field is a collection of stochastic integrals for a class of
deterministic integrands. The problem is then to extend the definition to
random integrands. An orthogonal decomposition of chaos space of the random
field leads to two such extensions, corresponding to the \Ito-Skorokhod and the
Stratononovich integrals, and provides an efficient tool to study these
integrals, both analytically and numerically. For a Gaussian process, a natural
definition of the integral follows from a canonical correspondence between
random processes and a special class of random fields.


title:
New interpretation for energy gap $\Delta$ of the cut-off approximation
  in the BCS theory of superconductivity

abstract:
  This paper concerns the solution of the self-consistency equation for energy
gap parameter $\Delta_{\bf k}$ in the BCS theory of superconductivity. We show
that there exists a well-defined relation between the solution for energy gap
parameter amplitude $|\Delta_{\bf k}|$ for a general interaction $V_{{\bf
k},{\bf k}'}$ and energy gap $\Delta$ obtained by using the cut-off
approximation. The relation between $|\Delta_{\bf k}|$ and $\Delta$ indicates
that $\Delta$ is a weighted average over $|\Delta_{\bf k}|$ of electronic
states within cut-off energy $\xi_c$ around the Fermi surface. In this
interpretation for $\Delta$, $\xi_c$ is not a property of $V_{{\bf k},{\bf
k}'}$, but a parameter specifying the energy range within which the weighted
average over $|\Delta_{\bf k}|$ is taken. We show that the proper choice for
the value of $\xi_c$ is only a few $k_BT_c$ (i.e., $\xi_c/k_BT_c$ is about 3 or
4). We also show that the cut-off approximation, even with
$\xi_c/k_BT_c=\infty$, is a good approximation when it is used to calculate
quantities such as the condensation energy and the specific heat, but it leads
to significant overestimation for the Josephson critical current density of a
Josephson junction if $\xi_c/k_BT_c \gg 1$ is assumed.


title:
Consequences Of Fully Dressing Quark-Gluon Vertex Function With
  Two-Point Gluon Lines

abstract:
  We extend recent studies of the effects of quark-gluon vertex dressing upon
the solutions of the Dyson-Schwinger equation for the quark propagator. A
momentum delta function is used to represent the dominant infrared strength of
the effective gluon propagator so that the resulting integral equations become
algebraic. The quark-gluon vertex is constructed from the complete set of
diagrams involving only 2-point gluon lines. The additional diagrams, including
those with crossed gluon lines, are shown to make an important contribution to
the DSE solutions for the quark propagator, because of their large color
factors and the rapid growth in their number.


title:
Theory for superconductivity in a magnetic field: A local approximation
  approach

abstract:
  We present a microscopic theory for superconductivity in a magnetic field
based on a local approximation approach. We derive an expression for free
energy density $F$ as a function of temperature $T$ and vector potential {\bf
a}, and two basic equations of the theory: the first is an implicit solution
for energy gap parameter amplitude $|\Delta_{\bf k}|$ as a function of wave
vector {\bf k}, temperature $T$ and vector potential {\bf a}; and the second is
a London-like relation between electrical current density {\bf j} and vector
potential {\bf a}, with an ``effective superconducting electron density'' $n_s$
that is both $T$- and {\bf a}-dependent. The two equations allow determination
of spatial variations of {\bf a} and $|\Delta_{\bf k}|$ in a superconductor for
given temperature $T$, applied magnetic field ${\bf H}_a$ and sample geometry.
The theory shows the existence of a ``partly-paired state,'' in which paired
electrons (having $|\Delta_{\bf k}|>0$) and de-paired electrons (having
$|\Delta_{\bf k}|=0$) co-exist. Such a ``partly-paired state'' exists even at
T=0 when $H_a$ is above a threshold for a given sample, giving rise to a
non-vanishing Knight shift at T=0 for $H_a$ above the threshold. We expect the
theory to be valid for highly-local superconductors for all temperatures and
magnetic fields below the superconducting transition. In the low-field limit,
the theory reduces to the local-limit result of BCS. As examples, we apply the
theory to the case of a semi-infinite superconductor in an applied magnetic
field ${\bf H}_a$ parallel to the surface of the superconductor and the case of
an isolated vortex in an infinite superconductor, and determine, in each case,
spatial variations of quantities such as {\bf a} and $|\Delta_{\bf k}|$. We
also calculate...


title:
Combining Weak Lensing Tomography with Halo Clustering to Probe Dark
  Energy

abstract:
  Two methods of constraining the properties of dark energy are weak lensing
tomography and cluster counting. Uncertainties in mass calibration of clusters
can be reduced by using the properties of halo clustering (the clustering of
clusters). However, within a single survey, weak lensing and halo clustering
probe the same density fluctuations. We explore the question of whether this
information can be used twice -- once in weak lensing and then again in halo
clustering to calibrate cluster masses -- or whether the combined dark energy
constraints are weaker than the sum of the individual constraints. For a survey
like the Dark Energy Survey (DES), we find that the cosmic shearing of source
galaxies at high redshifts is indeed highly correlated with halo clustering at
lower redshifts. Surprisingly, this correlation does not degrade cosmological
constraints for a DES-like survey, and in fact, constraints are marginally
improved since the correlations themselves act as additional observables. This
considerably simplifies the analysis for a DES-like survey: when weak lensing
and halo clustering are treated as independent experiments, the combined dark
energy constraints (cluster counts included) are accurate if not slightly
conservative. Our findings mirror those of Takada and Bridle, who investigated
correlations between the cosmic shear and cluster counts.


title: Model of embedded spaces: the field equations

abstract:
  A study of the Model of Embedded Spaces (MES) with a relativistic version of
Finslerian geometry is continued. The field equations of the MES (Einstein and
Maxwell types) are derived, and this formally completes geometrization of
classical electrodynamics. The minimal action principle leads to geometrization
of the field sources (the right-hand sides of the equations) and, as a
consequence, to a field hypothesis of matter, a direct confirmation of W.
Clifford's ideas.


title:
Inversely Unstable Solutions of Two-Dimensional Systems on Genus-p
  Surfaces and the Topology of Knotted Attractors

abstract:
  In this paper, we will show that a periodic nonlinear, time-varying
dissipative system that is defined on a genus-p surface contains one or more
invariant sets which act as attractors. Moreover, we shall generalize a result
in [Martins, 2004] and give conditions under which these invariant sets are not
homeomorphic to a circle individually, which implies the existence of chaotic
behaviour. This is achieved by studying the appearance of inversely unstable
solutions within each invariant set.


abstract:
  Toy models of a non-associative quantum mechanics are presented. The
Heisenberg equation of motion is modified using a non-associative commutator.
Possible physical applications of a non-associative quantum mechanics are
considered. The idea is discussed that a non-associative algebra could be the
operator language for the non-perturbative quantum theory. In such approach the
non-perturbative quantum theory has observables and unobservables quantities.


title: Cosmological Constraints on f(R) Acceleration Models

abstract:
  Models which accelerate the expansion of the universe through the addition of
a function of the Ricci scalar f(R) leave a characteristic signature in the
large-scale structure of the universe at the Compton wavelength scale of the
extra scalar degree of freedom. We search for such a signature in current
cosmological data sets: the WMAP cosmic microwave background (CMB) power
spectrum, SNLS supernovae distance measures, the SDSS luminous red galaxy power
spectrum, and galaxy-CMB angular correlations. Due to theoretical uncertainties
in the nonlinear evolution of f(R) models, the galaxy power spectrum
conservatively yields only weak constraints on the models despite the strong
predicted signature in the linear matter power spectrum. Currently the tightest
constraints involve the modification to the integrated Sachs-Wolfe effect from
growth of gravitational potentials during the acceleration epoch. This effect
is manifest for large Compton wavelengths in enhanced low multipole power in
the CMB and anti-correlation between the CMB and tracers of the potential. They
place a bound on the Compton wavelength of the field be less than of order the
Hubble scale.


title:
Causality and Unitarity Are Not Violated in Space-Times with an
  Additional Compact Time-like Dimension

abstract:
  The hypothesis that the causal properties of space-time, as well as other
properties of physical systems like unitarity, charge conservation, etc., might
be decided by the higher dimensional structure (in particular,
higher-dimensional physical laws), rather than by the four-dimensional one, is
explored in order to evade the most awkward problems of higher-dimensional
theories with compact extra time-like dimensions: violation of causality and of
unitarity.


title:
Leptogenesis and dark matter unified in a non-SUSY model for neutrino
  masses

abstract:
  We propose a unified explanation for the origin of dark matter and baryon
number asymmetry on the basis of a non-supersymmetric model for neutrino
masses. Neutrino masses are generated in two distinct ways, that is, a
tree-level seesaw mechanism with a single right-handed neutrino, and one-loop
radiative effects by a new additional doublet scalar. A spontaneously broken
U(1)$^\prime$ brings a $Z_2$ symmetry which restricts couplings of this new
scalar and controls the neutrino masses. It also guarantees the stability of a
CDM candidate. We examine two possible candidate for the CDM. We also show that
the decay of a heavy right-handed neutrino related to the seesaw mechanism can
generate baryon number asymmetry through leptogenesis.


title:
Realizable spin models and entanglement dynamics in superconducting flux
  qubit systems

abstract:
  Realizable spin models are investigated in a two superconducting flux qubit
system. It is shown that a specific adjustment of system parameters in the two
flux qubit system makes it possible to realize an artificial two-spin system
that cannot be found naturally. For the artificial two-spin systems, time
evolution of a prepared quantum state is discussed to quantify quantum
entanglement dynamics. The concurrence and fidelity as a function of time are
shown to reveal a characteristic entanglement dynamics of the artificial spin
systems. It is found that the unentangled input state can evolute to be a
maximally entangled output state periodically due to the exchange interactions
induced by two-qubit flipping tunneling processes while single-qubit flipping
tunneling processes plays a role of magnetic fields for the artificial spins.


title:
Existence and non-existence results for quasilinear elliptic exterior
  problems with nonlinear boundary conditions

abstract:
  Existence and non-existence results are established for quasilinear elliptic
problems with nonlinear boundary conditions and lack of compactness. The proofs
combine variational methods with the geometrical feature, due to the
competition between the different growths of the non-linearities.


title: Commuting linear operators and algebraic decompositions

abstract:
  For commuting linear operators $P_0,P_1,..., P_\ell$ we describe a range of
conditions which are weaker than invertibility. When any of these conditions
hold we may study the composition $P=P_0P_1... P_\ell$ in terms of the
component operators or combinations thereof. In particular the general
inhomogeneous problem $Pu=f$ reduces to a system of simpler problems. These
problems capture the structure of the solution and range spaces and, if the
operators involved are differential, then this gives an effective way of
lowering the differential order of the problem to be studied. Suitable systems
of operators may be treated analogously. For a class of decompositions the
higher symmetries of a composition $P$ may be derived from generalised
symmmetries of the component operators $P_i$ in the system.


title: Dispersion Relation for Alfven Waves in a Viscous, Diffusive Plasma

abstract:
  Propagation of Alfven waves in the solar plasma has been a topic of
scientific interest for a long time. We have derived a dispersion relation for
shear Alfven waves in a viscous and diffusive plasma.


title: Collective motion in quantum diffusive environment

abstract:
  The general problem of dissipation in macroscopic large-amplitude collective
motion and its relation to energy diffusion of intrinsic degrees of freedom of
a nucleus is studied. By applying the cranking approach to the nuclear
many-body system, a set of coupled dynamical equations for the collective
classical variable and the quantum mechanical occupancies of the intrinsic
nuclear states is derived. Different dynamical regimes of the intrinsic nuclear
motion and its consequences on time properties of collective dissipation are
discussed.


title: Parity violation in hydrogen revisited

abstract:
  We reconsider parity violation experiments in atomic hydrogen and deuterium
in the light of existing tests of the Electroweak interactions, and assess
whether new experiments, using improved experimental techniques, could make
useful contributions to testing the Standard Model (SM). We find that, if
parity experiments in hydrogen can be done, they remain highly desirable
because there is negligible atomic-physics uncertainty and low energy tests of
weak neutral current interactions are needed to probe for new physics beyond
the SM. Of particular interest would be a measurement of the nuclear spin
independent coupling C_{1D} for the deuteron at a combined error (theory +
experiment) of 0.3%. This would provide a factor of three improvement to the
precision on sin^2 theta_W at very low momentum transfer provided by heavy atom
Atomic Parity Violation (APV) experiments. Also, experiments in H and D could
provide precise measurements of three other electron-nucleon,
weak-neutral-current coupling constants: C_{1p}, C_{2p},and C_{2D}, which have
not been accurately determined to date. Analysis of a generic APV experiment in
deuterium indicates that a 0.3% measurement of C_{1D} requires development of a
slow (77K) metastable beam of ~ 5x10^14 D(2S) s^-1 per hyperfine component. The
advent of UV radiation from free electron laser (FEL) technology could allow
production of such a beam.


title: A New Type of Two-photon Forward Radiation in Pure Liquids

abstract:
  Unexpected spectral features are observed in the two photon spectrum of the
pure water in the forward direction when an 80 femtosecond laser pulse is
focused at 10^10Wcm-2 or less. Such intensity is much lower than the breakdown
or stimulated threshold of the liquid water. The two broad features are about
2700cm-1 and 5000cm-1 red shifted from the hyper-Rayleigh wavelength,
respectively, and they are quadratic with the laser intensity. They do not
match the known Raman or hyper-Raman frequencies of water, and they are both
centered at a narrow angle in the forward direction. Several other liquids also
exhibited similar but molecular specific spectral features.


title: On the Number of Nodal Domains of Random Spherical Harmonics

abstract:
  Let N(f) be a number of nodal domains of a random Gaussian spherical harmonic
f of degree n. We prove that as n grows to infinity, the mean of N(f)/n^2 tends
to a positive constant, and that N(f)/n^2 exponentially concentrates around
that constant.
  This result is consistent with predictions made by Bogomolny and Schmit using
a percolation-like model for nodal domains of random Gaussian plane waves.


title:
On the Supergravity Description of Wilson Loop in Non-commutative Dipole
  Field Theory

abstract:
  The Wilson loop in the non-commutative dipole field theory is re-examined
within the framework of dual gravity description. In contrast to the previous
investigations, we let the dual string be moving along the deformed $S^5$ and
find the exact expression of the interquark potential. The potential shows a
Coulomb behavior at all distance and does not have a minimum distance between
quarks, which exhibits in the static configuration. After comparing the
potential of the static and moving configurations we find that while the dual
string is static at long distance it will transit to a moving configuration at
short distance. We also analyze an electric dipole system and find that it
shows a similar transition property. Finally, we mention the unsuitable
approximation made in the previous paper [hep-th/0701069] and find that the
interquark potential in a gauge theory with a non-constant non-commutativity
has a Coulomb behavior at all distance.


title:
Violation of the London Law and Onsager-Feynman quantization in
  multicomponent superconductors

abstract:
  Non-classical response to rotation is a hallmark of quantum ordered states
such as superconductors and superfluids. The rotational responses of all
currently known single-component "super" states of matter (superconductors,
superfluids and supersolids) are largely described by two fundamental
principles and fall into two categories according to whether the systems are
composed of charged or neutral particles: the London law relating the angular
velocity to a subsequently established magnetic field and the Onsager-Feynman
quantization of superfluid velocity. These laws are theoretically shown to be
violated in a two-component superconductor such as the projected liquid
metallic states of hydrogen and deuterium at high pressures. The rotational
responses of liquid metallic hydrogen or deuterium identify them as a new class
of dissipationless states; they also directly point to a particular
experimental route for verification of their existence.


title: Generalized gauge-invariance for gravitational waves

abstract:
  The aim of this paper is to show the gauge-invariance on the response of
interferometers to gravitational waves (GWs). In this process, after a review
of results on the Tranverse-Traceless (TT) gauge, where, in general, the
theoretical computations on GWs are performed, which is due for completness, we
analyse the gauge of the local observer, which represents the gauge of a
laboratory environment on Earth. The gauge-invariance between the two gauges is
shown in its full angular and frequency dependences. In previous works in the
literature this gauge-invariance was shown only in the low frequencies
approximation or in the simplest geometry of the interferometer in respect to
the propagating GW (i.e. both of the arms of the interferometer are
perpendicular to the propagating GW). As far as the computation of the response
functions in the gauge of the local observer is concerned, a common
misconception about interferometers is also clarifed.


title:
Comparison of Theory and Direct Numerical Simulations of Drag Reduction
  by Rodlike Polymers in Turbulent Channel Flows

abstract:
  Numerical simulations of turbulent channel flows, with or without additives,
are limited in the extent of the Reynolds number \Re and Deborah number \De.
The comparison of such simulations to theories of drag reduction, which are
usually derived for asymptotically high \Re and \De, calls for some care. In
this paper we present a study of drag reduction by rodlike polymers in a
turbulent channel flow using direct numerical simulation and illustrate how
these numerical results should be related to the recently developed theory.


title: Maxwell Equations with Accounting of Tensor Properties of Time

abstract:
  The Maxwell equations with accounting for tensors properties of time have
been considered. The effects that follow from such consideration are described.
These are the appearance of vacuum polarization, anisotropy of electromagnetic
wave velocity in vacuum, anisotropy of the vacuum dielectric permittivity,
rotation of light polarization plane, as well as the existence of longitudinal
components of electromagnetic wave and the rotational (non-potential) component
of electric field caused by electric charges.


title: Multifractality and scale invariance in human heartbeat dynamics

abstract:
  Human heart rate is known to display complex fluctuations. Evidence of
multifractality in heart rate fluctuations in healthy state has been reported
[Ivanov et al., Nature {\bf 399}, 461 (1999)]. This multifractal character
could be manifested as a dependence on scale or beat number of the probability
density functions (PDFs) of the heart rate increments. On the other hand, scale
invariance has been recently reported in a detrended analysis of healthy heart
rate increments [Kiyono et al., Phys. Rev. Lett. {\bf 93}, 178103 (2004)]. In
this paper, we resolve this paradox by clarifying that the scale invariance
reported is actually exhibited by the PDFs of the sum of detrended healthy
heartbeat intervals taken over different number of beats, and demonstrating
that the PDFs of detrended healthy heart rate increments are scale dependent.
Our work also establishes that this scale invariance is a general feature of
human heartbeat dynamics, which is shared by heart rate fluctuations in both
healthy and pathological states.


title: Dynamical Systems on Three Manifolds Part I: Knots, Links and Chaos

abstract:
  In this paper, we give an explicit construction of dynamical systems (defined
within a solid torus) containing any knot (or link) and arbitrarily knotted
chaos. The first is achieved by expressing the knots in terms of braids,
defining a system containing the braids and extending periodically to obtain a
system naturally defined on a torus and which contains the given knotted
trajectories. To get explicit differential equations for dynamical systems
containing the braids, we will use a certain function to define a tube
neigbourhood of the braid. The second one, generating chaotic systems, is
realized by modeling the Smale horseshoe.


title:
Investigating interaction-induced chaos using time-dependent density
  functional theory

abstract:
  Systems whose underlying classical dynamics are chaotic exhibit signatures of
the chaos in their quantum mechanics. We investigate the possibility of using
time-dependent density functional theory (TDDFT) to study the case when chaos
is induced by electron-interaction alone. Nearest-neighbour level-spacing
statistics are in principle exactly and directly accessible from TDDFT. We
discuss how the TDDFT linear response procedure can reveal the mechanism of
chaos induced by electron-interaction alone. A simple model of a two-electron
quantum dot highlights the necessity to go beyond the adiabatic approximation
in TDDFT.


title:
The calculus structure of the Hochschild homology/cohomology of
  preprojective algebras of Dynkin quivers

abstract:
  The Hochschild homology/cohomology an associative algebra, together with the
Connes differential, the contraction map and the Lie derivative, forms the
structure of calculus. In this paper we compute explicitely the calculus
structure of preprojective algebras of Dynkin quivers over a field of
characteristic zero. This also completes the work in math.AG/0502301, where the
Batalin-Vilkovisky structure of the Hochschild cohomology of preprojective
algebras of non-Dynkin quivers are computed and the calculus can be easily
computed from that.


title:
Bose-Einstein condensation in semiconductors: the key role of dark
  excitons

abstract:
  The non elementary-boson nature of excitons controls Bose-Einstein
condensation in semiconductors. Composite excitons interact predominantly
through Pauli exclusion; this produces dramatic couplings between bright and
dark states. In microcavities, where bright excitons and photons form
polaritons, they force the condensate to be linearly polarized--as observed. In
bulk, they also force linear polarization, but of dark states, due to interband
Coulomb scatterings. To evidence this dark condensate, we thus need indirect
processes, like the shift it induces on the (bright) exciton line.


title: Higher K-theory via universal invariants

abstract:
  Using the formalism of Grothendieck's derivators, we construct `the universal
localizing invariant of dg categories'. By this, we mean a morphism U_l from
the pointed derivator associated with the Morita homotopy theory of dg
categories to a triangulated strong derivator M^loc such that U_l commutes with
filtered homotopy colimits, preserves the point, sends each exact sequence of
dg categories to a triangle and is universal for these properties. Similary, we
construct the `the universal additive invariant of dg categories', i.e. the
universal morphism of derivators U_a to a strong triangulated derivator M^add
which satisfies the first two properties but the third one only for split exact
sequences. We prove that Waldhausen K-theory appears as a mapping space in the
target of the universal additive invariant. This is the first conceptual
characterization of Quillen-Waldhausen's K-theory since its definition in the
early 70's. As an application we obtain for free the higher Chern characters
from K-theory to cyclic homology.


title: A Simple Method Which Generates Infinitely Many Congruence Identities

abstract:
  A simple method called symbolic representation for piecewise linear functions
on the real line is introduced and used to compute the numbers of periodic
points of all periods for some such functions. Since, for every positive
integer m, the number of periodic points of minimal period m must be divisible
by m, we obtain infinitely many congruence identities.


title: Pulse-shape discrimination with PbWO$_4$ crystal scintillators

abstract:
  The light output, $\alpha/\beta$ ratio, and pulse shape have been
investigated at $-25^\circ$ C with PbWO$_4$ crystal scintillators undoped, and
doped by F, Eu, Mo, Gd and S. The fast $0.01-0.06 \mu$s and middle $0.1-0.5
\mu$s components of scintillation decay were observed for all the samples. Slow
components of scintillation signal with the decay times $1-3 \mu$s and $13-28
\mu$s with the total intensity up to $\approx50%$ have been recognized for
several samples doped by Molybdenum. We found some indications of a pulse-shape
discrimination between $\alpha$ particles and $\gamma$ quanta with PbWO$_4$ (Mo
doped) crystal scintillators.


title:
Finite versus zero-temperature hysteretic behavior of spin glasses:
  Experiment and theory

abstract:
  We present experimental results attempting to fingerprint nonanalyticities in
the magnetization curves of spin glasses found by Katzgraber et al. [Phys. Rev.
Lett. 89, 257202 (2002)] via zero-temperature Monte Carlo simulations of the
Edwards-Anderson Ising spin glass. Our results show that the singularities at
zero temperature due to the reversal-field memory effect are washed out by the
finite temperatures of the experiments. The data are analyzed via the first
order reversal curve (FORC) magnetic fingerprinting method. The experimental
results are supported by Monte Carlo simulations of the Edwards-Anderson Ising
spin glass at finite temperatures which agree qualitatively very well with the
experimental results. This suggests that the hysteretic behavior of real Ising
spin-glass materials is well described by the Edwards-Anderson Ising spin
glass. Furthermore, reversal-field memory is a purely zero-temperature effect.


title: Anchoring effects at the isotropic-nematic interface in liquid crystals

abstract:
  The isotropic-to-nematic transition in liquid crystals is studied in d=3
spatial dimensions. A simulation method is proposed to measure the angle
dependent interfacial tension g(theta), with theta the anchoring angle of the
nematic phase at the interface. In addition, an alternative liquid crystal
model is introduced, defined on a lattice. The advantage of the lattice model
is that accurate simulations of anchoring effects become possible. For the
lattice model, g(theta) depends sensitively on the nearest-neighbor pair
interaction, and both stable and metastable anchoring angles can be detected.
We also measure g(theta) for an off-lattice fluid of soft rods. For soft rods,
only one stable anchoring angle is found, corresponding to homogeneous
alignment of the nematic director in the plane of the interface. This finding
is in agreement with most theoretical predictions obtained for hard rods.


title:
Long time viscosity of dilute magnetorheological dispersions under
  periodic magnetic perturbations

abstract:
  The effect of periodic magnetic perturbations on the rheological properties
of a low concentration magnetorheological dispersion is studied experimentally.
It is found that an important increment in the measured viscosity occurs when
in addition to a static field a magnetic periodic perturbation is applied. The
magnitude of these changes depend on the amplitude and frequency of the
perturbation as well as on the simultaneity of the application of the static
field and the perturbation. These findings are discussed in terms of the
observed rearrangement of the cluster structure in the dispersion.


title: Structural Relations between Harmonic Sums up to w=6

abstract:
  Multiply nested finite harmonic sums $S_{a_1 ... a_n}(N)$ occur in many
single scale higher order calculations in Quantum Field Theory. We discuss
their algebraic and structural relations to weight {\sf w=6}. As an example, we
consider the application of these relations to the soft and virtual corrections
for Bhabha-scattering to $O(\alpha^2)$.


title:
Dynamic radiation force of a pulsed Gaussian beam acting on a Rayleigh
  dielectric sphere

abstract:
  We investigate the dynamic evolution of the radiation forces produced by the
pulsed Gaussian beams acting on a Rayleigh dielectric sphere. We derive the
analytical expressions for the scattering force and all components of the
ponderomotive force induced by the pulsed Gaussian beams. Our analysis shows
that the radiation force, for both the transverse and longitudinal components,
can be greatly enhanced as the pulse duration decreases. It is further found
that for the pulse with long pulse duration, it can be used for the stable
trapping and manipulating the particle, while for the pulse with short pulse
duration it may be used for guiding and moving the small dielectric particle.
Finally we discuss the stability conditions of the effective manipulating the
particle by the pulsed beam.


title:
Multi-Hamiltonian structure for the finite defocusing Ablowitz-Ladik
  equation

abstract:
  We study the Poisson structure associated to the defocusing Ablowitz-Ladik
equation from a functional-analytical point of view, by reexpressing the
Poisson bracket in terms of the associated Caratheodory function. Using this
expression, we are able to introduce a family of compatible Poisson brackets
which form a multi-Hamiltonian structure for the Ablowitz-Ladik equation.
Furthermore, we show using some of these new Poisson brackets that the
Geronimus relations between orthogonal polynomials on the unit circle and those
on the interval define an algebraic and symplectic mapping between the
Ablowitz-Ladik and Toda hierarchies.


title: Universal discriminator for completely unknown optical qubits

abstract:
  We propose an experimental setup that is capable of unambiguously
discriminating any pair of linearly independent single photon polarization
qubits, about which we don't have any knowledge except that an extra pair of
these unknown states are provided as the reference. This setup, which is
constructed with optical CNOT gates, weak cross Kerr non-linearities, Bell
state analysers and other linear optical elements, transforms the unknown
triple photon input states to the corresponding single photon states to be
deterministically processed by linear optics circuit. The optimal
discrimination of the unknown states is achieved by this setup.


title: $\Lambda_{\rm QCD}$ and $\alpha_s(M_Z^2)$ from DIS Structure Functions

abstract:
  A brief summary is given on recent determinations of $\Lambda_{\rm QCD}$ and
$\alpha_s(M_Z^2)$ from deeply inelastic structure functions.


title: On the Cordial Deficiency of Complete Multipartite Graphs

abstract:
  We calculate the cordial edge deficiencies of the complete multipartite
graphs and find an upper bound for their cordial vertex deficiencies. We also
give conditions under which the tensor product of two cordial graphs is
cordial.


title: Toolbox for entanglement detection and fidelity estimation

abstract:
  The determination of the state fidelity and the detection of entanglement are
fundamental problems in quantum information experiments. We investigate how
these goals can be achieved with a minimal effort. We show that the fidelity of
GHZ and W states can be determined with an effort increasing only linearly with
the number of qubits. We also present simple and robust methods for other
states, such as cluster states and states in decoherence-free subspaces.


title:
A system for constructing relatively small polyhedra from Sonob\'e
  modules

abstract:
  We develop a quite elementary graph theoretic system for designing small-size
augmented origami polyhedra out of Sonob\'e modules beginning with a (convex or
not) deltahedron.


title: Interference and Outage in Clustered Wireless Ad Hoc Networks

abstract:
  In the analysis of large random wireless networks, the underlying node
distribution is almost ubiquitously assumed to be the homogeneous Poisson point
process. In this paper, the node locations are assumed to form a Poisson
clustered process on the plane. We derive the distributional properties of the
interference and provide upper and lower bounds for its CCDF. We consider the
probability of successful transmission in an interference limited channel when
fading is modeled as Rayleigh. We provide a numerically integrable expression
for the outage probability and closed-form upper and lower bounds.We show that
when the transmitter-receiver distance is large, the success probability is
greater than that of a Poisson arrangement. These results characterize the
performance of the system under geographical or MAC-induced clustering. We
obtain the maximum intensity of transmitting nodes for a given outage
constraint, i.e., the transmission capacity (of this spatial arrangement) and
show that it is equal to that of a Poisson arrangement of nodes. For the
analysis, techniques from stochastic geometry are used, in particular the
probability generating functional of Poisson cluster processes, the Palm
characterization of Poisson cluster processes and the Campbell-Mecke theorem.


title: Orbital Dynamics of Binary Boson Star Systems

abstract:
  We extend our previous studies of head-on collisions of boson stars by
considering orbiting binary boson stars. We concentrate on equal mass binaries
and study the dynamical behavior of boson/boson and boson/antiboson pairs. We
examine the gravitational wave output of these binaries and compare with other
compact binaries. Such a comparison lets us probe the apparent simplicity
observed in gravitational waves produced by black hole binary systems. In our
system of interest however, there is an additional internal freedom which plays
a significant role in the system's dynamics, namely the phase of each star. Our
evolutions show rather simple behavior at early times, but large differences
occur at late times for the various initial configurations.


title: Hollow Gaussian Schell-model beam and its propagation

abstract:
  In this paper, we present a new model, hollow Gaussian-Schell model beams
(HGSMBs), to describe the practical dark hollow beams. An analytical
propagation formula for HGSMBs passing through a paraxial first-order optical
system is derived based on the theory of coherence. Based on the derived
formula, an application example showing the influence of spatial coherence on
the propagation of beams is illustrated. It is found that the beam propagating
properties of HGSMBs will be greatly affected by their spatial coherence. Our
model provides a very convenient way for analyzing the propagation properties
of partially coherent dark hollow beams.


title:
Analysis of the expected number of bit comparisons required by
  Quickselect

abstract:
  When algorithms for sorting and searching are applied to keys that are
represented as bit strings, we can quantify the performance of the algorithms
not only in terms of the number of key comparisons required by the algorithms
but also in terms of the number of bit comparisons. Some of the standard
sorting and searching algorithms have been analyzed with respect to key
comparisons but not with respect to bit comparisons. In this paper, we
investigate the expected number of bit comparisons required by Quickselect
(also known as Find). We develop exact and asymptotic formulae for the expected
number of bit comparisons required to find the smallest or largest key by
Quickselect and show that the expectation is asymptotically linear with respect
to the number of keys. Similar results are obtained for the average case. For
finding keys of arbitrary rank, we derive an exact formula for the expected
number of bit comparisons that (using rational arithmetic) requires only finite
summation (rather than such operations as numerical integration) and use it to
compute the expectation for each target rank.


title: Adelic amoebas disjoint from open halfspaces

abstract:
  We show that a conjecture of Einsiedler, Kapranov, and Lind on adelic amoebas
of subvarieties of tori and their intersections with open halfspaces of
complementary dimension is false for subvarieties of codimension greater than
one that have degenerate projections to smaller dimensional tori. We prove a
suitably modified version of the conjecture using algebraic methods,
functoriality of tropicalization, and a theorem of Zhang on torsion points in
subvarieties of tori.


title: Minimal intersection of curves on surfaces

abstract:
  In the eighties Goldman discovered a Lie algebra structure on the vector
space generated by the free homotopy classes of oriented curves on an oriented
surface. The Lie bracket [a,b] is defined as the signed sum over the
intersection points of a and b of the loop product of at the intersection
points.
  If one of the classes has a simple representative we give a combinatorial
group theory description of the terms of the Lie bracket and prove that this
bracket has as many terms, counted with multiplicity, as the minimal number of
intersection points of a and b. In other words the bracket with a simple
element has no cancellation and determines minimal intersection numbers. We
show that analogous results hold for the Lie bracket (also discovered by
Goldman) of unoriented curves. We give three applications: a factorization of
Thurston's map defining the boundary of Teichmuller space, various
decompositions of the underlying vector space of conjugacy classes into ad
invariant subspaces and a connection between bijections of the set of conjugacy
classes of curves on a surface preserving the Goldman bracket and the mapping
class group.


title:
Reducible Families of Curves with Ordinary Multiple Points on Surfaces
  in Projective Three-Space

abstract:
  In math.AG/0108089, math.AG/0212090 and math.AG/0308247 we gave numerical
conditions which ensure that an equisingular family is irreducible respectively
T-smooth. Combining results by Greuel, Lossen and Shustin and an idea from
math.AG/9802009 we give in the present paper series of examples of families of
irreducible curves on surfaces in projective three-space with only ordinary
multiple points which are reducible and where at least one component does not
have the expected dimension. The examples show that for families of curves with
ordinary multiple points the conditions for T-smoothness in math.AG/0308247
have the right asymptotics.


title:
Some obstructed equisingular families of curves on surfaces in
  projective three-space

abstract:
  Very few examples of obstructed equsingular families of curves on surfaces
other than the projective plane are known. Combining results from Westenberger
and Hirano with an idea from math.AG/9802009 we give in the present paper
series of examples of families of irreducible curves with simple singularities
on surfaces in projective three-space which are not T--smooth, i.e. do not have
the expected dimension, and we compare this with conditions (showing the same
asymptotics) which ensure the existence of a T--smooth component.


title:
Experimental Evidence for Two-Dimensional Magnetic Order in Proton
  Bombarded Graphite

abstract:
  We have prepared magnetic graphite samples bombarded by protons at low
temperatures and low fluences to attenuate the large thermal annealing produced
during irradiation. An overall optimization of sample handling allowed us to
find Curie temperatures $ T_c \gtrsim 350$ K at the used fluences. The
magnetization versus temperature shows unequivocally a linear dependence, which
can be interpreted as due to excitations of spin waves in a two dimensional
Heisenberg model with a weak uniaxial anisotropy.


title:
Multiple inflation and the WMAP 'glitches' II. Data analysis and
  cosmological parameter extraction

abstract:
  Detailed analyses of the WMAP data indicate possible oscillatory features in
the primordial curvature perturbation, which moreover appears to be suppressed
beyond the present Hubble radius. Such deviations from the usual inflationary
expectation of an approximately Harrison-Zeldovich spectrum are expected in the
supergravity-based 'multiple inflation' model wherein phase transitions during
inflation induce sudden changes in the mass of the inflaton, thus interrupting
its slow-roll. In a previous paper we calculated the resulting curvature
perturbation and showed how the oscillations arise. Here we perform a Markov
Chain Monte Carlo fitting exercise using the 3-year WMAP data to determine how
the fitted cosmological parameters vary when such a primordial spectrum is used
as an input, rather than the usually assumed power-law spectrum. The
'concordance' LCDM model is still a good fit when there is just a 'step' in the
spectrum. However if there is a 'bump' in the spectrum (due e.g. to two phase
transitions in rapid succession), the precision CMB data can be well-fitted by
a flat Einstein-de Sitter cosmology without dark energy. This however requires
the Hubble constant to be h ~ 0.44 which is lower than the locally measured
value. To fit the SDSS data on the power spectrum of galaxy clustering requires
a ~10% component of hot dark matter, as would naturally be provided by 3
species of neutrinos of mass ~0.5 eV. This CHDM model cannot however fit the
position of the baryon acoustic peak in the LRG redshift two-point correlation
function. It may be possible to overcome these difficulties in an inhomogeneous
Lemaitre-Tolman-Bondi cosmological model with a local void, which can
potentially also account for the SN Ia Hubble diagram without invoking cosmic
acceleration.


title: Holographic interacting dark energy in the braneworld cosmology

abstract:
  We investigate a model of brane cosmology to find a unified description of
the radiation-matter-dark energy universe. It is of the interacting holographic
dark energy with a bulk-holographic matter $\chi$. This is a five-dimensional
cold dark matter, which plays a role of radiation on the brane. Using the
effective equations of state $\omega^{\rm eff}_{\rm \Lambda}$ instead of the
native equations of state $\omega_{\rm \Lambda}$, we show that this model
cannot accommodate any transition from the dark energy with $\omega^{\rm
eff}_{\rm \Lambda}\ge-1$ to the phantom regime $\omega^{\rm eff}_{\rm
\Lambda}<-1$. Furthermore, the case of interaction between cold dark matter and
five dimensional cold dark matter is considered for completeness. Here we find
that the redshift of matter-radiation equality $z_{\rm eq}$ is the same order
as $z^{\rm ob}_{\rm eq}=2.4\times10^{4} \Omega_{\rm m}h^2$. Finally, we obtain
a general decay rate $\Gamma$ which is suitable for describing all interactions
including the interaction between holographic dark energy and cold dark matter.


title: GRB Cosmology

abstract:
  Current observations are about to open up a direct window into the final
frontier of cosmology: the first billion years in cosmic history when the first
stars and galaxies formed. Even before the launch of the James Webb Space
Telescope, it might be possible to utilize Gamma-ray Bursts (GRBs) as unique
probes of cosmic star formation and the state of the intergalactic medium (IGM)
up to redshifts of several tens, when the first (Population III) stars had
formed. The Swift mission, or future satellites such as EXIST, might be the
first observatories to detect individual Population III stars, provided that
massive metal-free stars were able to trigger GRBs. Spectroscopic follow-up
observations of the GRB afterglow emission would allow to probe the ionization
state and metal enrichment of the IGM as a function of redshift.


title:
Transport and mixing by internal waves in stellar interiors: effect of
  the Coriolis force

abstract:
  We briefly recall the physical background of the transport of angular
momentum and the mixing of chemicals inside stellar radiation zones and its
importance for stellar evolution. Then, we describe its present modeling, its
successes and its weaknesses. Next, we introduce the new theoretical
developments that allow us to treat in a self-consistent way the effect of the
Coriolis force on the low-frequencies internal waves and its consequences for
the transport processes. This research is aimed at improving the modeling of
stellar interiors in the perspective of future astero and helioseismology
missions such as COROT and GOLF-NG.


title: On the topological stable rank of non-selfadjoint operator algebras

abstract:
  We provide a negative solution to a question of M. Rieffel who asked if the
right and left topological stable ranks of a Banach algebra must always agree.
Our example is found amongst a class of nest algebras. We show that for many
other nest algebras, both the left and right topological stable ranks are
infinite. We extend this latter result to Popescu's non-commutative disc
algebras and to free semigroup algebras as well.


title: A general treatment of geometric phases and dynamical invariants

abstract:
  Based only on the parallel transport condition, we present a general method
to compute Abelian or non-Abelian geometric phases acquired by the basis states
of pure or mixed density operators, which also holds for nonadiabatic and
noncyclic evolution. Two interesting features of the non-Abelian geometric
phase obtained by our method stand out: i) it is a generalization of Wilczek
and Zee's non-Abelian holonomy, in that it describes nonadiabatic evolution
where the basis states are parallelly transported between distinct degenerate
subspaces, and ii) the non-Abelian character of our geometric phase relies on
the transitional evolution of the basis states, even in the nondegenerate case.
We apply our formalism to a two-level system evolving nonadiabatically under
spontaneous decay to emphasize the non-Abelian nature of the geometric phase
induced by the reservoir. We also show, through the generalized invariant
theory, that our general approach encompasses previous results in the
literature.


title: Transitive spaces of operators

abstract:
  We investigate algebraic and topological transitivity and, more generally,
k-transitivity for linear spaces of operators. In finite dimensions, we
determine minimal dimensions of k-transitive spaces for every k, and find
relations between the degree of transitivity of a product or tensor product on
the one hand and those of the factors on the other. We present counterexamples
to some natural conjectures. Some infinite dimensional analogues are discussed.
A simple proof is given of Arveson's result on the weak-operator density of
transitive spaces that are masa bimodules.


title: Quantum Control of the Hyperfine Spin of a Cs Atom Ensemble

abstract:
  We demonstrate quantum control of a large spin-angular momentum associated
with the F=3 hyperfine ground state of 133Cs. A combination of time dependent
magnetic fields and a static tensor light shift is used to implement
near-optimal controls and map a fiducial state to a broad range of target
states, with yields in the range 0.8-0.9. Squeezed states are produced also by
an adiabatic scheme that is more robust against errors. Universal control
facilitates the encoding and manipulation of qubits and qudits in atomic ground
states, and may lead to improvement of some precision measurements.


title:
Quantum Discrete Fourier Transform with Classical Output for Signal
  Processing

abstract:
  Discrete Fourier transform (DFT) is the base of modern signal or information
processing. 1-Dimensional fast Fourier transform (1D FFT) and 2D FFT have time
complexity O(NlogN) and O(N^2logN) respectively. Quantum 1D and 2D DFT
algorithms with classical output (1D QDFT and 2D QDFT) are presented in this
paper. And quantum algorithm for convolution estimation is also presented in
this paper. Compared with FFT, QDFT has two advantages at least. One of
advantages is that 1D and 2D QDFT has time complexity O(sqrt(N)) and O(N)
respectively. The other advantage is that QDFT can process very long signal
sequence at a time. QDFT and quantum convolution demonstrate that quantum
signal processing with classical output is possible.


title:
Design of Electromagnetic Cloaks and Concentrators Using Form-Invariant
  Coordinate Transformations of Maxwell's Equations

abstract:
  The technique of applying form-invariant, spatial coordinate transformations
of Maxwell's equations can facilitate the design of structures with unique
electromagnetic or optical functionality. Here, we illustrate the
transformation-optical approach in the designs of a square electromagnetic
cloak and an omni-directional electromagnetic field concentrator. The
transformation equations are described and the functionality of the devices is
numerically confirmed by two-dimensional finite element simulations. The two
devices presented demonstrate that the transformation optic approach leads to
the specification of complex, anisotropic and inhomogeneous materials with well
directed and distinct electromagnetic behavior.


title:
Transitive decompositions of graphs and their links with geometry and
  origami

abstract:
  A transitive decomposition of a graph is a partition of the edge or arc set
giving a set of subgraphs which are preserved and permuted transitively by a
group of automorphisms of the graph. In this paper we give some background to
the study of transitive decompositions and highlight a connection with partial
linear spaces. We then describe a simple method for constructing transitive
decompositions using graph quotients, and we show how this may be used in an
application to modular origami.


title:
Lorentz shear modulus of a two-dimensional electron gas at high magnetic
  field

abstract:
  We show that the Lorentz shear modulus -- one of the three elastic moduli of
a homogeneous electron gas in a magnetic field -- can be calculated exactly in
the limit of high magnetic field (i.e. in the lowest Landau level). Its value
is $\pm \hbar n/4$, where $n$ is the two-dimensional electron density and the
sign is determined by the orientation of the magnetic field. We use this result
to refine our previous calculations of the dispersion of the collective modes
of fractional quantum Hall liquids.


title: Les classes d'Eisenstein des varietes de Hilbert-Blumenthal

abstract:
  This article deals with the Eisenstein classes of Hilbert-Blumenthal families
of abelian varieties. We first give a coordinate expression of these one at the
topological level, using currents defined by Levin. Then we study the
degeneration of these Eisenstein classes at a cusp of the Baily-Borel
compactification of the Hilbert-Blumenthal variety. We show, using the explicit
description of the Eisenstein classes obtained previously, that these classes
degenerate in special values of an $L$-function associated to the underlying
totally real number field. We deduce then both a geometric proof the
Klingen-Siegel Theorem and a non vanishing result for some of these Eisenstein
classes .


title: Charged Particle Production in High Q2 Deep-Inelastic Scattering at HERA

abstract:
  The average charged track multiplicity and the normalised distribution of the
scaled momentum, $\xp$, of charged final state hadrons are measured in
deep-inelastic $\ep$ scattering at high $Q^2$ in the Breit frame of reference.
The analysis covers the range of photon virtuality $100 < Q^2 < 20 000
\GeV^{2}$. Compared with previous results presented by HERA experiments this
analysis has a significantly higher statistical precision and extends the phase
space to higher $Q^{2}$ and to the full range of $\xp$. The results are
compared with $e^+e^-$ annihilation data and with various calculations based on
perturbative QCD using different models of the hadronisation process.


title: Constructive $\phi^4$ field theory without tears

abstract:
  We propose to treat the $\phi^4$ Euclidean theory constructively in a simpler
way. Our method, based on a new kind of "loop vertex expansion", no longer
requires the painful intermediate tool of cluster and Mayer expansions.


title: Modeling DNA beacons at the mesoscopic scale

abstract:
  We report model calculations on DNA single strands which describe the
equilibrium dynamics and kinetics of hairpin formation and melting. Modeling is
at the level of single bases. Strand rigidity is described in terms of simple
polymer models; alternative calculations performed using the freely rotating
chain and the discrete Kratky-Porod models are reported. Stem formation is
modeled according to the Peyrard-Bishop-Dauxois Hamiltonian. The kinetics of
opening and closing is described in terms of a diffusion-controlled motion in
an effective free energy landscape. Melting profiles, dependence of melting
temperature on loop length, and kinetic time scales are in semiquantitative
agreement with experimental data obtained from fluorescent DNA beacons forming
poly(T) loops. Variation in strand rigidity is not sufficient to account for
the large activation enthalpy of closing and the strong loop length dependence
observed in hairpins forming poly(A) loops. Implications for modeling single
strands of DNA or RNA are discussed.


title: Local Cloning of Entangled Qubits

abstract:
  We discuss the exact cloning of orthogonal but entangled qubits under local
operations and classical communication. The amount of entanglement necessary in
blank copy is obtained for various cases. Surprisingly this amount is more than
1 ebit for certain set of two nonmaximal but equally entangled states of two
qubits system. To clone any three two qubits Bell states at least log2 3 ebit
is necessary.


title:
Non-perturbative renormalization of the static vector current and its
  O(a)-improvement in quenched QCD

abstract:
  We carry out the renormalization and the Symanzik O(a)-improvement programme
for the static vector current in quenched lattice QCD. The scale independent
ratio of the renormalization constants of the static vector and axial currents
is obtained non-perturbatively from an axial Ward identity with Wilson-type
light quarks and various lattice discretizations of the static action. The
improvement coefficients cVstat and bVstat are obtained up to O(g_0^4)-terms by
enforcing improvement conditions respectively on the axial Ward identity and a
three-point correlator of the static vector current. A comparison between the
non-perturbative estimates and the corresponding one-loop results shows a
non-negligible effect of the O(g_0^4)-terms on the improvement coefficients but
a good accuracy of the perturbative description of the ratio of the
renormalization constants.


title: Highly efficient acoustooptic diffraction in Sn2P2S6 crystals

abstract:
  We have studied the acoustooptic (AO) diffraction in Sn2P2S6 crystals and
found that they manifest high values of AO figure of merit. The above crystals
may therefore be used as highly efficient materials in different AO
applications.


title: On the problem of phase transitions in lysozyme crystals

abstract:
  We present experimental evidence of the fact that lysozyme crystals, which
are grown from their mother solution and exist in it, dissolve on heating above
T=307 K. We argue that the anomaly in the light scattering recently observed at
the temperature T=307 K and identified in the reference [Svanidze A. V. et al.
2006. JETP Lett. 84: 551] as a structural crystalline phase transition in the
single lysozyme crystals, in fact, corresponds to a temperature limit of the
crystal existence.


title:
Frequency dependence of induced spin polarization and spin current in
  quantum wells

abstract:
  Dynamic response of two-dimensional electron systems with spin-orbit
interaction is studied theoretically on the basis of quantum kinetic equation,
taking into account elastic scattering of electrons. The spin polarization and
spin current induced by the applied electric field are calculated for the whole
class of electron systems described by p-linear spin-orbit Hamiltonians. The
absence of nonequilibrium intrinsic static spin currents is confirmed for these
systems with arbitrary (nonparabolic) electron energy spectrum. Relations
between the spin polarization, spin current, and electric current are
established. The general results are applied to the quantum wells grown in
[001] and [110] crystallographic directions, with both Rashba and Dresselhaus
types of spin-orbit coupling. It is shown that the existence of the fixed
(momentum-independent) precession axes in [001]-grown wells with equal Rashba
and Dresselhaus spin velocities or in symmetric [110]-grown wells leads to
vanishing spin polarizability at arbitrary frequency of the applied electric
field. This property is explained by the absence of Dyakonov-Perel-Kachorovskii
spin relaxation for the spins polarized along these precession axes. As a
result, a considerable frequency dispersion of spin polarization at very low
frequency in the vicinity of the fixed precession axes is predicted. Possible
effects of extrinsic spin-orbit coupling on the obtained results are discussed.


title: Classification of 3-dimensional integrable scalar discrete equations

abstract:
  We classify all integrable 3-dimensional scalar discrete quasilinear
equations Q=0 on an elementary cubic cell of the 3-dimensional lattice. An
equation Q=0 is called integrable if it may be consistently imposed on all
3-dimensional elementary faces of the 4-dimensional lattice.
  Under the natural requirement of invariance of the equation under the action
of the complete group of symmetries of the cube we prove that the only
nontrivial (non-linearizable) integrable equation from this class is the
well-known dBKP-system. (Version 2: A small correction in Table 1 (p.7) for n=2
has been made.) (Version 3: A few small corrections: one more reference added,
the main statement stated more explicitly.)


title:
Invariants of solvable Lie algebras with triangular nilradicals and
  diagonal nilindependent elements

abstract:
  The invariants of solvable Lie algebras with nilradicals isomorphic to the
algebra of strongly upper triangular matrices and diagonal nilindependent
elements are studied exhaustively. Bases of the invariant sets of all such
algebras are constructed by an original purely algebraic algorithm based on
Cartan's method of moving frames.


title: Visualizing Two Qubits

abstract:
  The notions of entanglement witnesses, separable and entangled states for two
qubits system can be visualized in three dimensions using the SLOCC equivalence
classes. This visualization preserves the duality relations between the various
sets and allows us to give ``proof by inspection'' of a non-elementary result
of the Horodeckies that for two qubits, Peres separability test is iff. We then
show that the CHSH Bell inequalities can be visualized as circles and cylinders
in the same diagram. This allows us to give a geometric proof of yet another
result of the Horodeckies, which optimizes the violation of the CHSH Bell
inequality. Finally, we give numerical evidence that, remarkably, allowing
Alice and Bob to use three rather than two measurements each, does not help
them to distinguish any new entangled SLOCC equivalence class beyond the CHSH
class.


title: Geometric scaling in the quantum Hall system

abstract:
  The transitions between neighbouring plateaux in the quantum Hall system are
observed to follow anti-holomophic scaling with superuniversal scaling
exponents, showing that the system contains an emergent sub-modular discrete
symmetry and a holomorphic structure at low energies. We identify a class of
effective scaling models consistent with this data, which is parametrized by
the complex structure of a torus with a special spin structure, in which only
the number of fermions (c) remains undetermined. For c = 2 this gives the
superuniversal anti-holomorphic scaling potential previously inferred from
data, with scaling exponent nu = 2.6, in reasonable agreement with available
scaling data.


title: Spin magnetotransport in two-dimensional hole systems

abstract:
  Spin current of two-dimensional holes occupying the ground-state subband in
an asymmetric quantum well and interacting with static disorder potential is
calculated in the presence of a weak magnetic field H perpendicular to the well
plane. Both spin-orbit coupling and Zeeman coupling are taken into account. It
is shown that the applied electric field excites both the transverse
(spin-Hall) and diagonal spin currents, the latter changes its sign at a finite
H and becomes greater than the spin-Hall current as H increases. The effective
spin-Hall conductivity introduced to describe the spin response in Hall bars is
considerably enhanced by the magnetic field in the case of weak disorder and
demonstrates a non-monotonic dependence on H.


title: Diamond thin Film Detectors for Beam Monitoring Devices

abstract:
  Diamonds offer radiation hard sensors, which can be used directly in primary
beams. Here we report on the use of a polycrystalline CVD diamond strip sensor
as beam monitor of heavy ion beams with up to 2.10^9 lead ions per bunch. The
strips allow for a determination of the transverse beam profile to a fraction
of the pitch of the strips, while the timing information yields the
longitudinal bunch length with a resolution of the order of a few mm.


title: Static impurities in the S=3/2 kagome lattice

abstract:
  We consider the effects of doping the S=3/2 kagome lattice with static,
nonmagnetic impurities. By exact diagonalization calculations on small clusters
we deduce the local spin correlations and magnetization distribution around a
vacancy. As in the S=1/2 kagome lattice, in the vicinity of the impurity we
find an extended region where the spin correlations are altered as a
consequence of frustation relief, and no indications for the formation of local
moments. We discuss the implications of our results for local probe
measurements on S=3/2 kagome materials.


title: Hole superconductivity in the electron-doped superconductor PCCO

abstract:
  We measure the resistivity and Hall angle of the electron-doped
superconductor Pr_{2-x}Ce_xCuO_4 as a function of doping and temperature. The
resistivity Rho_xx at temperatures 100K < T < 300K is mostly sensitive to the
electrons. Its temperature behavior is doping independent over a wide doping
range and even for non superconducting samples. On the other hand,the
transverse resistivity rho_xy, or the Hall angle theta_H where cot(theta_H) =
rho_xx/rho_xy, is sensitive to both holes and electrons. Its temperature
dependence is strongly influenced by doping, and cot(theta_H) can be used to
identify optimum doping (the maximum Tc) even well above the critical
temperature. These results lead to a conclusion that in electron doped cuprates
holes are responsible for the superconductivity.


title: New Model of N=8 Superconformal Mechanics

abstract:
  Using an N=4, d=1 superfield approach, we construct an N=8 supersymmetric
action of the self-interacting off-shell N=8 multiplet {\bf (1, 8, 7)}. This
action is found to be invariant under the exceptional N=8, d=1 superconformal
group F(4) with the R-symmetry subgroup SO(7). The general N=8 supersymmetric
{\bf (1, 8, 7)} action is a sum of the superconformal action and the previously
known free bilinear action. We show that the general action is also
superconformal, but with respect to redefined superfield transformation laws.
The scalar potential can be generated by two Fayet-Iliopoulos N=4 superfield
terms which preserve N=8 supersymmetry but break the superconformal and SO(7)
symmetries.


title:
Active Galactic Nuclei with Double-Peaked Balmer Lines: I. Black Hole
  Masses and the Eddington ratios

abstract:
  Using the stellar population synthesis, we model the stellar contribution for
a sample of 110 double-peaked broad-lines AGNs from the Sloan Digital Sky
Survey (SDSS). The stellar velocity dispersions ($\sigma_*$) are obtained for
52 double-peaked AGNs with obvious stellar absorption features, ranging from
106 to 284 \kms. We also use multi-component profiles to fit \OIII
$\lambda\lambda4959,5007$ and H$\beta$ emission lines. Using the
well-established $M_{\rm bh}-\sigma_*$ relation, the black hole masses are
calculated to range from $1.0\times 10^{7}$ to $5.5\times 10^{8}$ $\Msun$, and
the Eddington ratio from about 0.01 to about 1. Comparing with the known
$R_{\rm BLR}-L$ relation, we can get the factor $f$, which indicates BLRs'
geometry, inclination and kinematics. We find that $f$ far deviates from 0.75,
suggesting the non-virial dynamics of broad line regions. The peak separation
is mildly correlated with the Eddington ratio and SMBH mass with almost the
same correlation coefficients. It implies that it is difficult to detect
obvious double-peak AGNs with higher Eddington ratios. Using the monochromatic
luminosity at 5100\AA to trace the bolometric luminosity, we find that the
external illumination of the accretion disk is needed to produce the observed
strength of H$\alpha$ emission line.


title:
Double logarithmical corrections to beam asymmetry in polarized
  electron-proton scattering

abstract:
  The up-down asymmetry in transversally polarized electron proton scattering
is induced by the interference between one and two photon exchange amplitudes.
Inelastic intermediate hadronic states (different from one-proton state) of the
two photon exchange amplitude give rise to contributions containing the square
of "large logarithm" (logarithm of the ratio of the transferred momentum to the
electron mass). We investigate the presence of such contributions in higher
orders of perturbation theory. The relation with the case of zero transfer
momentum is explicitly given. The mechanism of cancellation of infrared
singularities is discussed.


title:
One-dimensional orbital fluctuations and the exotic magnetic properties
  of YVO$_3$

abstract:
  Starting from the Mott insulator picture for cubic vanadates, we derive and
investigate the model of superexchange interactions between V$^{3+}$ ions, with
nearly degenerate $t_{2g}$ orbitals occupied by two electrons each. The
superexchange interactions are strongly frustrated and demonstrate a strong
interrelation between possible types of magnetic and orbital order. We
elucidate the prominent role played by fluctuations of $yz$ and $xz$ orbitals
which generate ferromagnetic superexchange interactions even in the absence of
Hund's exchange. In this limit we find orbital valence bond state which is
replaced either by $C$-type antiferromagnetic order with weak $G$-type orbital
order at increasing Hund's exchange, or instead by $G$-type antiferromagnetic
order when the lattice distortions stabilize $C$-type orbital order. Both
phases are observed in YVO$_3$ and we argue that a dimerized $C$-type
antiferromagnetic phase with stronger and weaker FM bonds alternating along the
c axis may be stabilized by large spin-orbital entropy at finite temperature.
This suggests a scenario which explains the origin of the exotic $C$-AF order
observed in YVO$_3$ in the regime of intermediate temperatures and allows one
to specify the necessary ingredients of a more complete future theory.


title: On invariant 2x2 \beta-ensembles of random matrices

abstract:
  We introduce and solve exactly a family of invariant 2x2 random matrices,
depending on one parameter \eta, and we show that rotational invariance and
real Dyson index \beta are not incompatible properties. The probability density
for the entries contains a weight function and a multiple trace-trace
interaction term, which corresponds to the representation of the
Vandermonde-squared coupling on the basis of power sums. As a result, the
effective Dyson index \beta_{eff} of the ensemble can take any real value in an
interval. Two weight functions (Gaussian and non-Gaussian) are explored in
detail and the connections with \beta-ensembles of Dumitriu-Edelman and the
so-called Poisson-Wigner crossover for the level spacing are respectively
highlighted. A curious spectral twinning between ensembles of different
symmetry classes is unveiled. The proposed technical tool more generically
allows for designing actual matrix models which i) are rotationally invariant;
ii) have a real Dyson index \beta_{eff}; iii) have a pre-assigned confining
potential or alternatively level-spacing profile. The analytical results have
been checked through numerical simulations with an excellent agreement.
Eventually, we discuss possible generalizations and further directions of
research.


title: Spin-orbital entanglement near quantum phase transitions

abstract:
  Spin-orbital entanglement in the ground state of a one-dimensional
SU(2)$\otimes$SU(2) spin-orbital model is analyzed using exact diagonalization
of finite chains. For $S=1/2$ spins and $T=1/2$ pseudospins one finds that the
quantum entanglement is similar at the SU(4) symmetry point and in the
spin-orbital valence bond state. We also show that quantum transitions in
spin-orbital models turn out to be continuous under certain circumstances, in
constrast to the discontinuous transitions in spin models with SU(2) symmetry.


title: Target Mass Corrections in Diffractive Scattering

abstract:
  We describe the twist-2 contributions to inclusive unpolarized and polarized
deep-inelastic diffractive scattering in an operator approach. The
representation refers to the observed large rapidity gap but does not require
reference to a pomeron picture. We discuss both the case of vanishing target
mass $M$ and momentum transfer $t$ as well as the effects at finite $t$ and
$M$, which lead to modifications at large $\beta$ and low values of $Q^2$.


title:
Progresses in the Analysis of Stochastic 2D Cellular Automata: a Study
  of Asynchronous 2D Minority

abstract:
  Cellular automata are often used to model systems in physics, social
sciences, biology that are inherently asynchronous. Over the past 20 years,
studies have demonstrated that the behavior of cellular automata drastically
changed under asynchronous updates. Still, the few mathematical analyses of
asynchronism focus on one-dimensional probabilistic cellular automata, either
on single examples or on specific classes. As for other classic dynamical
systems in physics, extending known methods from one- to two-dimensional
systems is a long lasting challenging problem.
  In this paper, we address the problem of analysing an apparently simple 2D
asynchronous cellular automaton: 2D Minority where each cell, when fired,
updates to the minority state of its neighborhood. Our experiments reveal that
in spite of its simplicity, the minority rule exhibits a quite complex response
to asynchronism. By focusing on the fully asynchronous regime, we are however
able to describe completely the asymptotic behavior of this dynamics as long as
the initial configuration satisfies some natural constraints. Besides these
technical results, we have strong reasons to believe that our techniques
relying on defining an energy function from the transition table of the
automaton may be extended to the wider class of threshold automata.


title: Operator space entanglement entropy in transverse Ising chain

abstract:
  The efficiency of time dependent density matrix renormalization group methods
is intrinsically connected with the rate of entanglement growth. We introduce a
new measure of entanglement in the space of operators and show, for transverse
Ising spin 1/2 chain, that the simulation of observables, contrary to
simulation of typical pure quantum states, is efficient for initial local
operators. For initial operators with a finite index in Majorana
representation, the operator space entanglement entropy saturates with time to
a level which is calculated analytically, while for initial operators with
infinite index the growth of operator space entanglement entropy is shown to be
logarithmic.


title:
Information functionals and the notion of (un)certainty: RMT - inspired
  case

abstract:
  Information functionals allow to quantify the degree of randomness of a given
probability distribution, either absolutely (through min/max entropy
principles) or relative to a prescribed reference one. Our primary aim is to
analyze the "minimum information" assumption, which is a classic concept (R.
Balian, 1968) in the random matrix theory. We put special emphasis on generic
level (eigenvalue) spacing distributions and the degree of their randomness, or
alternatively - information/organization deficit.

categories: quant-ph cond-mat.stat-mech math-ph math.MP nlin.CD physics.data-an


title:
Intrinsic Spin Hall Effect: Topological Transitions in Two-Dimensional
  Systems

abstract:
  The spin-Hall conductivity in spatially-homogeneous two-dimensional electron
systems described by the spin-orbit Hamiltonian \hbar \Omega_p \sigma is
presented as a sum of the universal part Me/8 \pi \hbar determined by the Berry
phase \Phi=M \pi (M is an odd integer, the winding number of the vector
\Omega_p) and a non-universal part which vanishes under certain conditions
determined by the analytical properties of \Omega_p. The analysis reveals a
rich and complicated behavior of the spin-Hall conductivity which is relevant
to both electron and hole states in quantum wells and can be detected in
experiments.


title: An extension of a Bourgain--Lindenstrauss--Milman inequality

abstract:
  Let || . || be a norm on R^n. Averaging || (\eps_1 x_1, ..., \eps_n x_n) ||
over all the 2^n choices of \eps = (\eps_1, ..., \eps_n) in {-1, +1}^n, we
obtain an expression ||| . ||| which is an unconditional norm on R^n.
  Bourgain, Lindenstrauss and Milman showed that, for a certain (large)
constant \eta > 1, one may average over (\eta n) (random) choices of \eps and
obtain a norm that is isomorphic to ||| . |||. We show that this is the case
for any \eta > 1.


title: Congruence Identities Arising From Dynamical Systems

abstract:
  By counting the numbers of periodic points of all periods for some interval
maps, we obtain infinitely many new congruence identities in number theory.


title: Time and Entropy in the Foundations of Mechanics

abstract:
  This contribution analyses the classical laws of motion by means of an
approach relating time and entropy. We argue that adopting the notion of change
of states as opposed to the usual derivation of Newton's laws in terms of
fields a broader picture is obtained, suggesting that diverse branches of
physics- classical, quantum, relativistic and statistical mechanics - turn out
to be related by a common foundation.


title:
Semiclassical Dynamics of Electron Wave Packet States with Phase
  Vortices

abstract:
  We consider semiclassical higher-order wave packet solutions of the
Schrodinger equation with phase vortices. The vortex line is aligned with the
propagation direction, and the wave packet carries a well-defined orbital
angular momentum (OAM) $\hbar l$ ($l$ is the vortex strength) along its main
linear momentum. The probability current coils around momentum in such OAM
states of electrons. In an electric field, these states evolve like massless
particles with spin $l$. The magnetic-monopole Berry curvature appears in
momentum space, which results in a spin-orbit-type interaction and a
Berry/Magnus transverse force acting on the wave packet. This brings about the
OAM Hall effect. In a magnetic field, there is a Zeeman interaction, which, can
lead to more complicated dynamics.

categories: quant-ph cond-mat.mes-hall cond-mat.other physics.optics


title: Smallest 90o domains in epitaxial ferroelectric films

abstract:
  Ferroelectrics display spontaneous and switchable electrical polarization.
Until recently, ferroelectricity was believed to disappear at the nanoscale;
now, nano-ferroelectrics are being considered in numerous applications. This
renewed interest was partly fuelled by the observation of ferroelectric domains
in films of a few unit cells thickness, promising further size reduction of
ferroelectric devices. It turns out that at reduced scales and dimensionalities
the material's properties depend crucially on the intricacies of domain
formation, that is, the way the crystal splits into regions with polarization
oriented along the different energetically equivalent directions, typically at
180o and 90o from each other. Here we present a step forward in the
manipulation and control of ferroelectric domains by the growth of thin films
with regular self-patterned arrays of 90o domains only 7 nm wide. This is the
narrowest width for 90o domains in epitaxial ferroelectrics that preserves the
film lateral coherence, independently of the substrate.


title: Should physicists begin experimental study of the God's physical nature?

abstract:
  Inequality of forward and reversed processes in quantum physics means an
existence of a memory of quantum system about the initial state. Importance of
its experimental study for correct interpretation of quantum mechanics and
understanding of a physical base of a consciousness is discussed.


title: Perturbations of Schwarzschild black holes in laboratories

abstract:
  It is well-known that the perturbations of Schwarzschild black holes are
governed by a wave equation with some effective potential. We consider
perturbations of a gas in a tube called Laval nozzle, which is narrow in the
middle and has a sonic point in the throat. By equating the wave equation in a
Laval nozzle of an arbitrary form with the wave equation of spin-s
perturbations of Schwarzschild black holes, we find the exact expression for
the form of the Laval nozzle, for which acoustic perturbations of the gas flow
corresponds to the general form of perturbations of Schwarzschild black holes.
This allows observation, in a laboratory, of the acoustic waves, which are
analogue of damping quasinormal oscillations of Schwarzschild black holes. The
found exact acoustic analog allows to observe also some other phenomena
governed by the wave equation, such as the wave scattering and tunneling.


title: Electron scattering on microscopic corrugations in graphene

abstract:
  We discuss various scattering mechanisms for Dirac fermions in single-layer
graphene. It is shown that scattering on a short-range potential (due to, for
example, neutral impurities) is mostly irrelevant for electronic quality of
graphene, which is likely to be controlled by charged impurities and ripples
(microscopic corrugations of a graphene sheet). The latter are an inherent
feature of graphene due to its two-dimensional nature and can also be an
important factor in defining the electron mean free path. We show that certain
types of ripples create a long-range scattering potential, similar to Coulomb
scatterers, and result in charge-carrier mobility practically independent on
carrier concentration, in agreement with experimental observations.