title:
Andreev Current-Induced Dissipation in a Hybrid Superconducting Tunnel
  Junction

abstract:
  We have studied hybrid superconducting micro-coolers made of a double
Superconductor-Insulator-Normal metal tunnel junction. Under subgap conditions,
the Andreev current is found to dominate the single-particle tunnel current. We
show that the Andreev current introduces additional dissipation in the normal
metal equivalent to Joule heating. By analyzing quantitatively the heat balance
in the system, we provide a full description of the evolution of the electronic
temperature with the voltage. The dissipation induced by the Andreev current is
found to dominate the quasiparticle tunneling-based cooling over a large bias
range.


title: Sign Language Tutoring Tool

abstract:
  In this project, we have developed a sign language tutor that lets users
learn isolated signs by watching recorded videos and by trying the same signs.
The system records the user's video and analyses it. If the sign is recognized,
both verbal and animated feedback is given to the user. The system is able to
recognize complex signs that involve both hand gestures and head movements and
expressions. Our performance tests yield a 99% recognition rate on signs
involving only manual gestures and 85% recognition rate on signs that involve
both manual and non manual components, such as head movement and facial
expressions.


title: Anisotropic selection in cellular genetic algorithms

abstract:
  In this paper we introduce a new selection scheme in cellular genetic
algorithms (cGAs). Anisotropic Selection (AS) promotes diversity and allows
accurate control of the selective pressure. First we compare this new scheme
with the classical rectangular grid shapes solution according to the selective
pressure: we can obtain the same takeover time with the two techniques although
the spreading of the best individual is different. We then give experimental
results that show to what extent AS promotes the emergence of niches that
support low coupling and high cohesion. Finally, using a cGA with anisotropic
selection on a Quadratic Assignment Problem we show the existence of an
anisotropic optimal value for which the best average performance is observed.
Further work will focus on the selective pressure self-adjustment ability
provided by this new selection scheme.


title:
The Modeling of Time-Structured Multiturn Injection into Fermilab Main
  Injector (Microbunch Injection with Parasitic Longitudinal Painting)

abstract:
  This paper presents the modeling of time-structured multiturn injection for
an upgraded Main Injector with the 8-GeV Superconducting RF proton driver, or
an ILC-style linac, or a Project-X linac. The Radio-Frequency mismatch between
a linac and the upgraded Main Injector will induce parasitic longitudinal
painting in RF-phase direction. Several different scenarios with a choice of
different RF parameters for single RF system and double RF system in the
presence of longitudinal space charge have been investigated. From the studies
of microbunch injection with the aid of ESME (2003) numerical simulations, it
is found that the dual RF system with a choice of appropriate RF parameters
allows us to overcome the space-charge limitation set by beam intensity during
the multiturn-injection process. A double RF system with a harmonic ratio (R_H
= H_2/H_1) of 2.0 and a voltage ratio (R_V = V_2/V_1) of 0.5 are most favored
to reduce both longitudinal and transverse effects of space charge in the Main
Injector.


title: Remark on orbital precession due to central-force perturbations

abstract:
  This is a comment on the recent paper by G. S. Adkins and J. McDonnell
``Orbital precession due to central-force perturbations'' published in Phys.
Rev. D75 (2007), 082001 [arXiv:gr-qc/0702015]. We show that the main result of
this paper, the formula for the precession of Keplerian orbits induced by
central-force perturbations, can be obtained very simply by the use of
Hamilton's vector.


title: Fixed Point and Aperiodic Tilings

abstract:
  An aperiodic tile set was first constructed by R.Berger while proving the
undecidability of the domino problem. It turned out that aperiodic tile sets
appear in many topics ranging from logic (the Entscheidungsproblem) to physics
(quasicrystals) We present a new construction of an aperiodic tile set that is
based on Kleene's fixed-point construction instead of geometric arguments. This
construction is similar to J. von Neumann self-reproducing automata; similar
ideas were also used by P. Gacs in the context of error-correcting
computations. The flexibility of this construction allows us to construct a
"robust" aperiodic tile set that does not have periodic (or close to periodic)
tilings even if we allow some (sparse enough) tiling errors. This property was
not known for any of the existing aperiodic tile sets.


title:
Effect of finite chemical potential on QGP-Hadron phase transition in a
  statistical model of fireball formation

abstract:
  We study the effect of finite chemical potential for the QGP constituents in
the Ramanathan et al. statistical model (Phys.Rev.C70, 027903,2004). While the
earlier computations using this model with vanishing chemical potentials
indicated a weakly first order phase transition for the system in the vicinity
of 170 MeV (Pramana, 68, 757, 2007), the introduction of finite values for the
chemical potentials of the constituents makes the transition a smooth roll over
of the phases, while allowing fireball formation with radius of a few "fermi"
to take place. This seems to be in conformity with the latest consensus on the
nature of the QGP-Hadron phase transition.
  Keywords: Quark Gluon Plasma, Quark Hadron Phase Transition


title:
Compatibility of 1/n and epsilon expansions for critical exponents at
  m-axial Lifshitz points

abstract:
  The critical behaviour of d-dimensional n-vector models at m-axial Lifshitz
points is considered for general values of m in the large-n limit. It is proven
that the recently obtained large-N expansions [J. Phys.: Condens. Matter 17,
S1947 (2005)] of the correlation exponents \eta_{L2}, \eta_{L4} and the related
anisotropy exponent \theta are fully consistent with the dimensionality
expansions to second order in \epsilon=4+m/2-d [Phys. Rev. B 62, 12338 (2000);
Nucl. Phys. B 612, 340 (2001)] inasmuch as both expansions yield the same
contributions of order \epsilon^2/n.


title: Octonic Electrodynamics

abstract:
  In this paper we present eight-component values "octons", generating
associative noncommutative algebra. It is shown that the electromagnetic field
in a vacuum can be described by a generalized octonic equation, which leads
both to the wave equations for potentials and fields and to the system of
Maxwell's equations. The octonic algebra allows one to perform compact combined
calculations simultaneously with scalars, vectors, pseudoscalars and
pseudovectors. Examples of such calculations are demonstrated by deriving the
relations for energy, momentum and Lorentz invariants of the electromagnetic
field. The generalized octonic equation for electromagnetic field in a matter
is formulated.


title:
Spin-orbit coupling and crystal-field splitting in the electronic and
  optical properties of nitride quantum dots with a wurtzite crystal structure

abstract:
  We present an $sp^3$ tight-binding model for the calculation of the
electronic and optical properties of wurtzite semiconductor quantum dots (QDs).
The tight-binding model takes into account strain, piezoelectricity, spin-orbit
coupling and crystal-field splitting. Excitonic absorption spectra are
calculated using the configuration interaction scheme. We study the electronic
and optical properties of InN/GaN QDs and their dependence on structural
properties, crystal-field splitting, and spin-orbit coupling.


title:
Modeling fragmentation of the self-gravitating molecular layer by
  smoothed particle hydrodynamics

abstract:
  We revisit the modeling of ion-neutral (or ambipolar) diffusion with two
fluid smoothed particle hydrodynamics, as discussed by Hosking & Whitworth.
Some parts of the technique are optimized to testify the pioneer works on
behavior of the ambipolar diffusion in an isothermal self-gravitating layer.
The frictional heating by ambipolar diffusion is examined, and its effect on
fragmentation of the layer is studied. The results are compared to the thermal
phases of instability as obtained by Nejad-Asghar.


title: Peterson's Deformations of Higher Dimensional Quadrics

abstract:
  We provide the first explicit examples of deformations of higher dimensional
quadrics: a straightforward generalization of Peterson's explicit 1-dimensional
family of deformations in $\mathbb{C}^3$ of 2-dimensional general quadrics with
common conjugate system given by the spherical coordinates on the complex
sphere $\mathbb{S}^2\subset\mathbb{C}^3$ to an explicit $(n-1)$-dimensional
family of deformations in $\mathbb{C}^{2n-1}$ of $n$-dimensional general
quadrics with common conjugate system given by the spherical coordinates on the
complex sphere $\mathbb{S}^n\subset\mathbb{C}^{n+1}$ and non-degenerate joined
second fundamental forms. It is then proven that this family is maximal.


title: Fermats Last Theorem on Topological Fields

abstract:
  Even though flt is a number theoretic result we prove that the result depends
on the topological as well as the field structure of the underlying space.


title: Genus Distributions For Extended Matrix Models Of RNA

abstract:
  We construct and study an extended random matrix model of RNA (polymer)
folding. A perturbation which acts on all the nucleotides in the chain is added
to the action of the RNA partition function. The effect of this perturbation on
the partition function and the Genus Distributions is studied. This
perturbation distinguishes between the paired and unpaired bases. For example,
for $\alpha = 1$ (where $\alpha$ is the ratio of the strengths of the original
and perturbed term in the action) the partition function and genus distribution
for odd lengths vanish completely. This partition function and the genus
distribution is non-zero for even lengths where structures with fully paired
bases only remain. This implies that (i). the genus distributions are different
and (ii). there is a ``structural transition'' (from an ``unpaired-paired base
phase'' to a ``completely paired base phase'') as $\alpha$ approaches 1 in the
extended matrix models. We compare the results of the extended RNA model with
the results of G. Vernizzi, H. Orland and A. Zee in PRL 94, 168103(2005).


title: Variations on Log Sarkisov Program for Surfaces

abstract:
  Let (S, BS) be the log-pair associated with a compactification of a given
smooth quasi-projective surface V . Under the assumption that the boundary BS
is irreducible, we propose an algorithm, in the spirit of the (log) Sarkisov
program, to factorize any automorphism of V into a sequence of elementary links
in the framework of the logarithmic Mori theory. The new noteworthy feature of
our algorithm is that all the blow-ups and contractions involved in the process
occur on the boundary.


title: Finite- to zero-range relativistic mean-field interactions

abstract:
  We study the relation between the finite-range (meson-exchange) and
zero-range (point-coupling) representations of effective nuclear interactions
in the relativistic mean-field framework. Starting from the phenomenological
interaction DD-ME2 with density-dependent meson-nucleon couplings, we construct
a family of point-coupling effective interactions for different values of the
strength parameter of the isoscalar-scalar derivative term. In the
meson-exchange picture this corresponds to different values of the
$\sigma$-meson mass. The parameters of the isoscalar-scalar and
isovector-vector channels of the point-coupling interactions are adjusted to
nuclear matter and ground-state properties of finite nuclei. By comparing
results for infinite and semi-infinite nuclear matter, ground-state masses,
charge radii, and collective excitations, we discuss constraints on the
parameters of phenomenological point-coupling relativistic effective
interaction.


title:
Bell's Inequality, Quantum Measurement and Einstein Realism: A Unified
  Perspective

abstract:
  The logical foundations of Bell's inequality are reexamined. We argue that
the form of the reality condition that underpins Bell's inequality comes from
the requirement of solving the quantum measurement problem. Hence any violation
of Bell's inequality necessarily implies nonlocality because of the measurement
problem. The differences in the implications of deterministic and stochastic
formulations of Bell's inequality are highlighted. The reality condition used
in Bell's inequality is shown to be a generalisation of Einstein's later form
of realism.


title: Quantum and quasiclassical types of superfluid turbulence

abstract:
  By injecting negative ions in superfluid 4He in the zero-temperature limit (T
< 0.5 K), we generated tangles of quantized vortex line with negligible
large-scale flow. For this quantum regime of superfluid turbulence, the vortex
line length L was found to decay at late time t as L proportional to t^{-1};
the prefactor being independent of the initial value of L. The corresponding
effective kinematic viscosity is 0.1 kappa, where kappa is the circulation
quantum. At T > 0.7 K, a jet of ions generates quasi-classical tangles
identical to those produced by mechanical means.


title: On the mass center of the tent map

abstract:
  It is well known that the time average or the center of mass for generic
orbits of the standard tent map is 0.5. In this paper we show some interesting
properties of the exceptional orbits, including periodic orbits, orbits without
mass center, and orbits with mass centers different from 0.5. We prove that for
any positive integer $n$, there exist $n$ distinct periodic orbits for the
standard tent map with the same center of mass, and the set of mass centers of
periodic orbits is a dense subset of $[0,2/3]$. Considering all possible
orbits, then the set of mass centers is the interval $[0,2/3]$. Moreover, for
every $x$ in $[0,2/3]$, there are uncountably many orbits with mass center $x$.
We also show that there are uncountably many orbits without mass center.


title:
Evolution of Compact-Binary Populations in Globular Clusters: A
  Boltzmann Study II. Introducing Stochasticity

abstract:
  We continue exploration of the Boltzmann scheme started in Banerjee and Ghosh
(2007, henceforth Paper I) for studying the evolution of compact-binary
populations of globular clusters, introducing in this paper our method of
handling the stochasticity inherent in dynamical processes of binary formation,
destruction and hardening in globular clusters. We describe these stochastic
processes as "Wiener processes", whereupon the Boltzmann equation becomes a
stochastic partial differential equation, the solution of which requires the
use of "Ito calculus" (this use being the first, to our knowledge, in this
subject), in addition to ordinary calculus. We focus on the evolution of (a)
the number of X-ray binaries $N_{XB}$ in globular clusters, and (b) the
orbital-period distribution of these binaries. We show that, although the
details of the fluctuations in the above quantities differ from one
"realization" to another of the stochastic processes, the general trends follow
those found in the continuous-limit study of Paper I, and the average result
over many such realizations is close to the continuous-limit result. We
investigate the dependence of $N_{XB}$ found by these calculations on two
essential globular-cluster parameters, namely, the star-star and star-binary
encounter-rate parameters $\Gamma$ and $\gamma$, for which we had coined the
name Verbunt parameters in Paper I. We compare our computed results with those
from CHANDRA observations of Galactic globular clusters, showing that the
expected scalings of $N_{XB}$ with the Verbunt parameters are in good agreement
with the observed ones. We indicate what additional features can be
incorporated into the scheme in future, and how more elaborate problems can be
tackled.


title: A note on canonical quantization of fields on a manifold

abstract:
  We propose a general construction of quantum states for linear canonical
quantum fields on a manifold, which encompasses and generalizes the "standard"
procedures existing in textbooks. Our method provides pure and mixed states on
the same footing. A large class of examples finds a simple and unified
treatment in our approach. Applications discussed here include thermodynamical
equilibrium states for Minkowski fields and quantum field theory in the
Rindler's and in the open de Sitter universes. Our approach puts the above
examples into perspective and unravels new possibilities for quantization. We
call our generalization "extended canonical quantization" as it is suited to
attack cases not directly covered by the standard canonical approach.


title: An Arrow of Time Operator for Standard Quantum Mechanics

abstract:
  We introduce a self-adjoint operator that indicates the direction of time
within the framework of standard quantum mechanics. That is, as a function of
time its expectation value decreases monotonically for any initial state. This
operator can be defined for any system governed by a Hamiltonian with a
uniformly finitely degenerate, absolutely continuous and semibounded spectrum.
We study some of the operator's properties and illustrate them for a large
equivalence class of scattering problems. We also discuss some previous
attempts to construct such an operator, and show that the no-go theorems
developed in this context are not applicable to our construction.


title:
Quasinormal modes in the background of charged Kaluza-Klein black hole
  with squashed horizons

abstract:
  We study the scalar perturbation in the background of the charged
Kaluza-Klein black holes with squashed horizons. We find that the position of
infinite discontinuities of the heat capacities can be reflected in quasinormal
spectrum. This shows the possible non-trivial relation between the
thermodynamical and dynamical properties of black holes.


title:
Motion of Spin 1/2 Massless Particle in a Curved Spacetime. I.
  Lagrangian Approach

abstract:
  Quasi-classical picture of motion of spin 1/2 massless particle in a curved
spacetime is built on base of simple Lagrangian model. The one is constructed
due to analogy with Lagrangian of massive spin 1/2 particle. Equations of
motion and spin propagation coincide with Papapetrou equations describing
dynamic of photon in a curved spacetime.


title: Capacity of General Discrete Noiseless Channels

abstract:
  This paper concerns the capacity of the discrete noiseless channel introduced
by Shannon. A sufficient condition is given for the capacity to be
well-defined. For a general discrete noiseless channel allowing non-integer
valued symbol weights, it is shown that the capacity--if well-defined--can be
determined from the radius of convergence of its generating function, from the
smallest positive pole of its generating function, or from the rightmost real
singularity of its complex generating function. A generalisation is given for
Pringsheim's Theorem and for the Exponential Growth Formula to generating
functions of combinatorial structures with non-integer valued symbol weights.


title:
Space laser interferometers can determine the thermal history of the
  early Universe

abstract:
  It is shown that space-based gravitational wave detectors such as DECIGO
and/or Big Bang Observer (BBO) will provide us with invaluable information on
the cosmic thermal history after inflation and they will be able to determine
the reheat temperature $T_R$ provided that it lies in the range preferred by
the cosmological gravitino problem, $T_R\sim 10^{5-9}$ GeV. Therefore it is
strongly desired that they will be put into practice as soon as possible.


title:
Phase Transitions in Separated $D_{p-1}$ and anti-$D_{p-1}$ Branes at
  Finite Temperature

abstract:
  We consider a pair of parallel ${\rm D}_{p-1}$ and anti-${\rm D}_{p-1}$
branes in flat space, with a finite separation $d$ along some perpendicular
spatial direction and at finite temperature. If this spatial direction is
compactified on a circle then by T-duality, the system is equivalent to a ${\rm
D}_{p}$-anti ${\rm D}_{p} $ pair wrapped around the dual circle with a constant
Wilson line $A \approx d $ on one of the branes. We focus in particular on the
$p=9$ case and compute the free energy of this system and study the occurrence
of second order phase transitions as both the temperature and Wilson line
(brane-antibrane separation) are varied. In the limit of vanishing Wilson line
we recover the previous results obtained in the literature, whereby the open
string vacuum at the origin of the tachyon field T=0 is stabilized at
sufficiently high temperature at which a second order phase transition occurs.
For sufficiently large Wilson line, we find new second order phase transitions
corresponding to the existence of two minima in the tachyon effective potential
at finite temperature and tachyon field value. Entropic arguments suggest that
as the system cools, the tachyon is likely to find itself in the minimum that
approaches infinity as the temperature vanishes (i.e. the one corresponding to
the closed string vacuum), rather than the minimum at T=0 (corresponding to the
open string vacuum).


title: On A-tensors in Riemannian geometry

abstract:
  We present examples, both compact and non-compact complete, of lo- cally
non-homogeneous proper A-manifolds.


title: Pacifying the Fermi-liquid: battling the devious fermion signs

abstract:
  The fermion sign problem is studied in the path integral formalism. The
standard picture of Fermi liquids is first critically analyzed, pointing out
some of its rather peculiar properties. The insightful work of Ceperley in
constructing fermionic path integrals in terms of constrained world-lines is
then reviewed. In this representation, the minus signs associated with
Fermi-Dirac statistics are self consistently translated into a geometrical
constraint structure (the {\em nodal hypersurface}) acting on an effective
bosonic dynamics. As an illustrative example we use this formalism to study
1+1-dimensional systems, where statistics are irrelevant, and hence the sign
problem can be circumvented. In this low-dimensional example, the structure of
the nodal constraints leads to a lucid picture of the entropic interaction
essential to one-dimensional physics. Working with the path integral in
momentum space, we then show that the Fermi gas can be understood by analogy to
a Mott insulator in a harmonic trap. Going back to real space, we discuss the
topological properties of the nodal cells, and suggest a new holographic
conjecture relating Fermi liquids in higher dimensions to soft-core bosons in
one dimension. We also discuss some possible connections between mixed
Bose/Fermi systems and supersymmetry.


title: Hawking Fluxes, Back reaction and Covariant Anomalies

abstract:
  Starting from the chiral covariant effective action approach of Banerjee and
Kulkarni [Phys. Lett. B 659, 827(2008)], we provide a derivation of the Hawking
radiation from a charged black hole in the presence of gravitational back
reaction. The modified expressions for charge and energy flux, due to effect of
one loop back reaction are obtained.


title: Visualization of Branch Points in PT-Symmetric Waveguides

abstract:
  The visualization of an exceptional point in a PT symmetric directional
coupler(DC) is demonstrated. In such a system the exceptional point can be
probed by varying only a single parameter. Using the Rayleigh-Schroedinger
perturbation theory we prove that the spectrum of a PT symmetric Hamiltonian is
real as long as the radius of convergence has not been reached. We also show
how one can use a PT symmetric DC to measure the radius of convergence for non
PT symmetric structures. For such systems the physical meaning of the rather
mathematical term: radius of convergence, is exemplified.


title: Properties of dusty tori in AGN: I. The Case of SWIRE/SDSS Quasars

abstract:
  We derive the properties of dusty tori in Active Galactic Nuclei (AGN) from
the comparison of observed Spectral Energy Distributions (SEDs) of SDSS quasars
and a precomputed grid of torus models. The observed SEDs comprise SDSS
photometry, 2MASS J, H, and K data, whenever available and mid-Infrared (MIR)
data from the Spitzer Wide-area InfraRed Extragalactic (SWIRE) Survey. The
adopted model is that of Fritz et al., 2006. The fit is performed by standard
chi^2 minimisation, the model however can be multi-component comprising a
stellar and a starburst components, whenever necessary. Models with low
equatorial optical depth, tau_9.7, were allowed as well as ``traditional''
models with tau_9.7 > 1.0, corresponding to A_V > 22 and the results were
compared. Fits using high optical depth tori models only produced dust more
compactly distributed than in the configuration where all tau_9.7 models were
permitted. Tori with decreasing dust density with the distance from the centre
were favoured while there was no clear preference for models with or without
angular variation of the dust density. The computed outer radii of the tori are
of some tens of parsecs large but can reach, in a few cases, a few hundreds of
parsecs. The mass of dust, M_Dust, and infrared luminosity, L_IR, integrated in
the wavelength range between 1 and 1000 micron, do not show significant
variations with redshift, once the observational biases are taken into account.
Objects with 70 micron detections, representing 25% of the sample, are studied
separately and the starburst contribution (whenever present) to the IR
luminosity can reach, in the most extreme but very few cases, 80%.


title:
Exploring the relativistic regime with Newtonian hydrodynamics: II. An
  effective gravitational potential for rapid rotation

abstract:
  We present the generalization of a recently introduced modified gravitational
potential for self-gravitating fluids. The use of this potential allows for an
accurate approximation of general relativistic effects in an otherwise
Newtonian hydrodynamics code also in cases of rapid rotation. We test this
approach in numerical simulations of astrophysical scenarios related to compact
stars, like supernova core collapse with both a simplified and detailed
microphysical description of matter, and rotating neutron stars in equilibrium.
We assess the quality of the new potential, and demonstrate that it provides a
significant improvement compared to previous formulations for such potentials.
Newtonian simulations of compact objects employing such an effective
relativistic potential predict inaccurate pulsation frequencies despite the
excellent agreement of the collapse dynamics and structure of the compact
objects with general relativistic results. We analyze and discuss the reason
for this behavior.


title: Is there potential complementarity between LISA and pulsar timing?

abstract:
  We open the discussion into how the Laser Interferometer Space Antenna (LISA)
observations of supermassive black-hole (SMBH) mergers (in the mass range
~10^6-10^8 Msun) may be complementary to pulsar timing-based gravitational wave
searches. We consider the toy model of determining pulsar distances by
exploiting the fact that LISA SMBH inspiral observations can place tight
parameter constraints on the signal present in pulsar timing observations. We
also suggest, as a future path of research, the use of LISA ring-down
observations from the most massive (>~ a few 10^7 Msun) black-hole mergers, for
which the inspiral stage will lie outside the LISA band, as both a trigger and
constraint on searches within pulsar timing data for the inspiral stage of the
merger.


title: Effective Field Theory of the Single-Nucleon Sector

abstract:
  We address the issue of a consistent power counting scheme in manifestly
Lorentz-invariant baryon chiral perturbation theory. We discuss the inclusion
of vector mesons in the calculation of the nucleon electromagnetic form
factors. We comment on the chiral expansion of the nucleon mass to order
O(q**6).


title: Primordial Black Hole: Mass and Angular Momentum Evolution

abstract:
  The evolution of the primordial low mass black hole (PBH) in hot universe is
considered. Increase of mass and decrease of PBH spin due to the accretion of
radiation dominated matter are estimated with using of results of numerical
simulation of PBH formation and approximate relations for accretion to a
rotating black hole.


title: Nuclear spin dynamics and Zeno effect in quantum dots and defect centers

abstract:
  We analyze nuclear spin dynamics in quantum dots and defect centers with a
bound electron under electron-mediated coupling between nuclear spins due to
the hyperfine interaction ("J-coupling" in NMR). Our analysis shows that the
Overhauser field generated by the nuclei at the position of the electron has
short-time dynamics quadratic in time for an initial nuclear spin state without
transverse coherence. The quadratic short-time behavior allows for an extension
of the Overhauser field lifetime through a sequence of projective measurements
(quantum Zeno effect). We analyze the requirements on the repetition rate of
measurements and the measurement accuracy to achieve such an effect. Further,
we calculate the long-time behavior of the Overhauser field for effective
electron Zeeman splittings larger than the hyperfine coupling strength and
find, both in a Dyson series expansion and a generalized master equation
approach, that for a nuclear spin system with a sufficiently smooth
polarization the electron-mediated interaction alone leads only to a partial
decay of the Overhauser field by an amount on the order of the inverse number
of nuclear spins interacting with the electron.


title:
Gamma-Ray Spectroscopy of $^{16}_\Lambda$O and $^{15}_\Lambda$N
  Hypernuclei via the $^{16}$O$(K^-, \pi^-)$ reaction

abstract:
  he bound-state level structures of the $^{16}_{\Lambda}$O and
$^{15}_{\Lambda}$N hypernuclei were studied by $\gamma$-ray spectroscopy using
a germanium detector array (Hyperball) via the $^{16}$O ($K^-, \pi^- \gamma$)
reaction. A level scheme for $^{16}_{\Lambda}$O was determined from the
observation of three $\gamma$-ray transitions from the doublet of states
($2^-$,$1^-$) at $\sim 6.7$ MeV to the ground-state doublet ($1^-$,$0^-$). The
$^{15}_{\Lambda}$N hypernuclei were produced via proton emission from unbound
states in $^{16}_{\Lambda}$O . Three $\gamma$ -rays were observed and the
lifetime of the $1/2^+;1$ state in $^{15}_{\Lambda}$N was measured by the
Doppler shift attenuation method. By comparing the experimental results with
shell-model calculations, the spin-dependence of the $\Lambda N$ interaction is
discussed. In particular, the measured $^{16}_{\Lambda}$O ground-state doublet
spacing of 26.4 $\pm$ 1.6 $\pm$ 0.5 keV determines a small but nonzero strength
of the $\Lambda N$ tensor interaction.


title: A trial symbolic dynamics of the planar three-body problem

abstract:
  Symbolic dynamics is applied to the planar three-body problem. Symbols are
defined on the planar orbit when it experiences a syzygy crossing. If the body
i is in the middle at the syzygy crossing and the vectorial area of the
triangle made with three bodies changes sign from + to -, number i is given to
this event, whereas if the vectorial area changes sign from - to +, number i+3
is given. We examine the case of free-fall three-body problem for the first few
digits of symbol sequences, and we examine the case with angular momentum only
for the first digit of the symbol sequences. This trial experiments show some
new aspects of the planar three-body problem.


title:
Theoretical and numerical study of the phase diagram of patchy colloids:
  ordered and disordered patch arrangements

abstract:
  We report theoretical and numerical evaluations of the phase diagram for a
model of patchy particles. Specifically we study hard-spheres whose surface is
decorated by a small number f of identical sites ("sticky spots'') interacting
via a short-range square-well attraction. We theoretically evaluate, solving
the Wertheim theory, the location of the critical point and the gas-liquid
coexistence line for several values of f and compare them to results of Gibbs
and Grand Canonical Monte Carlo simulations. We study both ordered and
disordered arrangements of the sites on the hard-sphere surface and confirm
that patchiness has a strong effect on the phase diagram: the gas-liquid
coexistence region in the temperature-density plane is significantly reduced as
f decreases. We also theoretically evaluate the locus of specific heat maxima
and the percolation line.


title: Folding = Colouring

abstract:
  The foldings of a connected graph $G$ are defined as follows. First, $G$ is a
folding of itself. Let $G'$ be a graph obtained from $G$ by identifying two
vertices at distance 2 in $G$. Then every folding of $G'$ is a folding of $G$.
The folding number of $G$ is the minimum order of a complete folding of $G$.
Theorem: The folding number of every graph equals its chromatic number.


title: On the distribution of eigenvalues of non-selfadjoint operators

abstract:
  We prove quantitative bounds on the eigenvalues of non-selfadjoint bounded
and unbounded operators. We use the perturbation determinant to reduce the
problem to one of studying the zeroes of a holomorphic function.


title: Optimal Controlled teleportation via several kinds of three-qubit states

abstract:
  The probability of successfully controlled teleportating an unknown qubit
using a general three-particle state is investigated. We give the analytic
expressions of maximal probabilities of successfully controlled teleportating
an unknown qubit via several kinds of tripartite states including a tripartite
GHZ state and a tripartite W-state.


title: Jet substructure as a new Higgs search channel at the LHC

abstract:
  It is widely considered that, for Higgs boson searches at the Large Hadron
Collider, WH and ZH production where the Higgs boson decays to b anti-b are
poor search channels due to large backgrounds. We show that at high transverse
momenta, employing state-of-the-art jet reconstruction and decomposition
techniques, these processes can be recovered as promising search channels for
the standard model Higgs boson around 120 GeV in mass.


title:
The single-degenerate channel for the progenitor of type Ia supernovae
  with different metallicities

abstract:
  The single-degenerate channel for the progenitors of type Ia supernovae (SNe
Ia) are currently accepted, in which a carbon-oxygen white dwarf (CO WD)
accretes hydrogen-rich material from its companion, increases its mass to the
Chandrasekhar mass limit, and then explodes as a SN Ia. Incorporating the
prescription of \citet{HAC99a} for the accretion efficiency into Eggleton's
stellar evolution code and assuming that the prescription is valid for
\emph{all} metallicities, we performed binary stellar evolution calculations
for more than 25,000 close WD binaries with metallicities $Z=0.06, 0.05, 0.04,
0.03, 0.02, 0.01, 0.004, 0.001, 0.0003$ and 0.0001. For our calculations, the
companions are assumed to be unevolved or slightly evolved stars (WD + MS). As
a result, the initial parameter spaces for SNe Ia at various $Z$ are presented
in orbital period-secondary mass ($\log P_{\rm i}, M_{\rm 2}^{\rm i}$) planes.
Our study shows that both the initial mass of the secondary and the initial
orbital period increase with metallicity. Thus, the minimum mass of the CO WD
for SNe Ia decreases with metallicity $Z$. The difference of the minimum mass
may be as large as 0.24 $M_{\odot}$ for different Z.
  Adopting the results above, we studied the birth rate of SNe Ia for various
$Z$ via a binary population synthesis approach. If a single starburst is
assumed, SNe Ia occur systemically earlier and the peak value of the birth rate
is larger for a high $Z$. The Galactic birth rate from the WD + MS channel is
lower than (but comparable to) that inferred from observations. Our study
indicates that supernovae like SN2002ic would not occur in extremely
low-metallicity environments, if the delayed dynamical-instability model in
\citet{HAN06} is appropriate.


title: Sequentially generated states for the study of two dimensional systems

abstract:
  Matrix Product States can be defined as the family of quantum states that can
be sequentially generated in a one-dimensional system. We introduce a new
family of states which extends this definition to two dimensions. Like in
Matrix Product States, expectation values of few body observables can be
efficiently evaluated and, for the case of translationally invariant systems,
the correlation functions decay exponentially with the distance. We show that
such states are a subclass of Projected Entangled Pair States and investigate
their suitability for approximating the ground states of local Hamiltonians.


title:
Self-consistent renormalization theory of spin fluctuations in
  paramagnetic spinel LiV2O4

abstract:
  A phenomenological description for the dynamical spin susceptibility
$\chi({\bf q},\omega;T)$ observed in inelastic neutron scattering measurements
on powder samples of LiV$_2$O$_4$ is developed in terms of the parametrized
self-consistent renormalization (SCR) theory of spin fluctuations. Compatible
with previous studies at $T\to 0$, a peculiar distribution in ${\bf q}$-space
of strongly enhanced and slow spin fluctuations at $q \sim Q_c \simeq$ 0.6
$\AA^{-1}$ in LiV$_2$O$_4$ is involved to derive the mode-mode coupling term
entering the basic equation of the SCR theory. The equation is solved
self-consistently with the parameter values found from a fit of theoretical
results to experimental data. For low temperatures, $T \lesssim 30$K, where the
SCR theory is more reliable, the observed temperature variations of the static
spin susceptibility $\chi(Q_c;T)$ and the relaxation rate $\Gamma_Q(T)$ at
$q\sim Q_c$ are well reproduced by those suggested by the theory. For $T\gtrsim
30$K, the present SCR is capable in predicting only main trends in
$T$-dependences of $\chi(Q_c;T)$ and $\Gamma_Q(T)$.
  The discussion is focused on a marked evolution (from $q \sim Q_c$ at $T\to
0$ towards low $q$ values at higher temperatures) of the dominant low-$\omega$
integrated neutron scattering intensity $I(q; T)$.


title:
A remark on the Herzlich volume of asymptotically complex hyperbolic
  Einstein manifolds

abstract:
  We observe inequalities involving the Herzlich volume of a 4-dimensional
asymptotically complex hyperbolic Einstein manifold and its Euler
characteristic provided the metrics is either Kaehler or selfdual. In the
selfdual case we have to assume furthermore that the Kronheimer-Mrowka
invariant is non vanishing.


title: A Note on Generating Functions for Hausdorff Moment Sequences

abstract:
  For functions $f$ whose Taylor coefficients at the origin form a Hausdorff
moment sequence we study the behaviour of $w(y):=|f(\gamma+iy)|$ for $y>0$
($\gamma\leq1$ fixed).


title:
Theoretical Analysis of the Energy Capture in Strictly Bandlimited
  Ultra-Wideband Channels

abstract:
  The frequency selectivity of wireless communication channels can be
characterized by the delay spread Ds of the channel impulse response. If the
delay spread is small compared to the bandwidth W of the input signal, that is,
Ds*W approximately equal to 1, the channel appears to be flat fading. For Ds*W
>> 1, the channel appears to be frequency selective, which is usually the case
for wideband signals. In the first case, small scale synchronization with a
precision much higher than the sampling time T = 1/W is crucial. In this paper,
it is shown by analytical means that this is different in the wideband regime.
Here synchronization with a precision of T is sufficient and small scale
synchronization cannot further increase the captured energy at the receiver.
Simulation results show that this effect already occurs for W > 50MHz for the
IEEE 802.15.4a channel model.


title: Small-scale flows in SUMER and TRACE high-cadence co-observations

abstract:
  We report on the physical properties of small-scale transient flows observed
simultaneously at high cadence with the SUMER spectrometer and the TRACE imager
in the plage area of an active region. Our major objective is to provide a
better understanding of the nature of transient phenomena in the solar
atmosphere by using high-cadence imager and spectrometer co-observations at
similar spatial and temporal resolution. A sequence of TRACE Fe IX/X 171 A and
high-resolution MDI images were analysed together with simultaneously obtained
SUMER observations in spectral lines covering a temperature range from 10 000 K
to 1 MK. We reveal the existence of numerous transient flows in small-scale
loops (up to 30 Mm) observed in the plage area of an active region. These flows
have temperatures from 10 000 K (the low temperature limit of our observations)
to 250 000 K. The coronal response of these features is uncertain due to a
blending of the observed coronal line Mg X 624.85 A. The duration of the events
ranges from 60 s to 19 min depending on the loop size. Some of the flows reach
supersonic velocities. The Doppler shifts often associated with explosive
events or bi-directional jets can actually be identified with flows (some of
them reaching supersonic velocities) in small-scale loops. Additionally, we
demonstrate how a line-of-sight effect can give misleading information on the
nature of the observed phenomena if only either an imager or a spectrometer is
used.


title: Markov loops and renormalization

abstract:
  We study Poissonian ensembles of Markov loops and the associated renormalized
self-intersection local times.


title:
Modelling of the moving deformed triple contact line: influence of the
  fluid inertia

abstract:
  For partial wetting, motion of the triple liquid-gas-solid contact line is
influenced by heterogeneities of the solid surface. This influence can be
strong in the case of inertial (e.g. oscillation) flows where the line can be
pinned or move intermittently. A model that takes into account both surface
defects and fluid inertia is proposed. The viscous dissipation in the bulk of
the fluid is assumed to be negligible as compared to the dissipation in the
vicinity of the contact line. The equations of motion and the boundary
condition at the contact line are derived from Hamilton's principle. The rapid
capillary rise along a vertical inhomogeneous wall is treated as an example.


title:
Manifestation of Vacancies in a Spectrum of Organic Molecular Crystal
  Lattice Vibrations

abstract:
  Using a method Raman of spectroscopy and considering a non-uniformity of
allocation of vacancies in a monocrystal, it is shown that lines with the small
intensity (caused by presence of vacancies) have a major intensity in the
sample of a larger size than in the sample of a smaller size. Increase of an
intensity of lines at vacancy concentration increase can reveal which lines are
related to presence of vacancies in the sample. For a p-dichlorobenzene, it is
lines of a small intensity in a spectrum of the lattice oscillations in the
field of 70 cm^{-1}.


title:
K3-surfaces with special symmetry: An example of classification by
  Mori-reduction

abstract:
  The classification problem for K3-surfaces equipped with finite groups $H$ of
symplectic symmetry centralized by an antisymplectic involution is considered.
An approach via equivariant Mori-reduction is employed. This method, which has
proved to be successful even for rather small groups, is exemplified here by
giving a complete classification in the case $H = C_3 \ltimes C_7$. The
consideration of this particular group is related to the study of K3-surfaces
with maximal finite groups of symplectic automorphisms. Applications to the
case $L_2(7)$ are given.


title:
Determination of Vacancies Allocation in a Monocrystal of a
  P-Dichlorobenzene Using a Method of the Raman Spectroscopy

abstract:
  The method of Raman scattering is used to investigate the cross edge of a
p-dichlorobenzene monocrystal, which was grown up by a Bridgmen method.
Comparison of intensities of additional lines of a spectrum of the lattice
oscillations of certain parts of an edge of a monocrystal with density of these
fields has allowed to relate some lines to presence of vacancies in structure.


title:
Ultrasensitive Proximity Josephson Sensor with Kinetic Inductance
  Read-Out

abstract:
  We propose a mesoscopic kinetic-inductance radiation detector based on a long
superconductor--normal metal--superconductor Josephson junction. The operation
of this proximity Josephson sensor (PJS) relies on large kinetic inductance
variations under irradiation due to the exponential temperature dependence of
the critical current. Coupled with a dc SQUID readout, the PJS is able to
provide a signal to noise (S/N) ratio up to ~10^3 in the THz regime if operated
as calorimeter, while electrical noise equivalent power (NEP) as low as
~7x10^{-20} W(Hz)^(-1/2) at 200 mK can be achieved in the bolometer operation.
The high performance together with the ease of fabrication make this structure
attractive as an ultrasensitive cryogenic detector of THz electromagnetic
radiation.


title: Nuclear Interactions: The Chiral Picture

abstract:
  Chiral expansions of the two-pion exchange components of both two- and
three-nucleon forces are reviewed and a discussion is made of the predicted
pattern of hierarchies. The strength of the scalar-isoscalar central potential
is found to be too large and to defy expectations from the symmetry. The causes
of this effect can be understood by studying the nucleon scalar form factor.


title:
Dynamical reentrance and geometry imposed quantization effects in
  Nb-AlOx-Nb Josephson junction arrays

abstract:
  In this paper, we report on different phenomena related to the magnetic
properties of artificially prepared highly ordered (periodic) two-dimensional
Josephson junction arrays (2D-JJA) of both shunted and unshunted Nb-AlOx-Nb
tunnel junctions. By employing mutual-inductance measurements and using a
high-sensitive bridge, we have thoroughly investigated (both experimentally and
theoretically) the temperature and magnetic field dependence of complex AC
susceptibility of 2D-JJA. We also demonstrate the use of the scanning SQUID
microscope for imaging the local flux distribution within our unshunted arrays.


title:
Diffraction-managed solitons and nonlinear beam diffusion in modulated
  arrays of optical waveguides

abstract:
  We study propagation of light in nonlinear diffraction-managed photonic
lattices created with arrays of periodically-curved coupled optical waveguides
which were fabricated using femtosecond laser writing in silica glass, and
titanium indiffusion in LiNbO3 crystals. We identify different regimes of the
nonlinear propagation of light beams depending on the input power, and present
the first experimental observation of diffraction-managed solitons, which are
formed as a result of the interplay between the engineered beam diffraction and
nonlinear self-focusing or defocusing. We observe that in self-collimating
structures where linear diffraction is suppressed, a novel regime of nonlinear
beam diffusion takes place at the intermediate powers before the lattice
soliton is formed at higher powers.


title:
Solving Cosmological Problems of Supersymmetric Axion Models in an
  Inflationary Universe

abstract:
  We revisit inflationary cosmology of axion models in the light of recent
developments on the inflaton decay in supergravity. We find that all the
cosmological difficulties, including gravitino, axino overproduction and
axionic isocurvature fluctuation, can be avoided if the saxion field has large
initial amplitude during inflation and decays before big-bang nucleosynthesis.


title:
Fast Fourier Transform computations and build-up of plastic deformation
  in 2D, elastic-perfectly plastic, pixelwise disordered porous media

abstract:
  Stress and strain fields in a two-dimensional pixelwise disordered system are
computed by a Fast Fourier Transform method. The system, a model for a ductile
damaged medium, consists of an elastic-perfectly matrix containing void pixels.
Its behavior is investigated under equibiaxial or shear loading. We monitor the
evolution with loading of plastically deformed zones, and we exhibit a
nucleation / growth / coalescence scenario of the latter. Identification of
plastic ``clusters'' is eased by using a discrete Green function implementing
equilibrium and continuity at the level of one pixel. Observed morphological
regimes are put into correspondence with some features of the macroscopic
stress / strain curves.


title: Redshift Distribution of Extragalactic 24 micron Sources

abstract:
  We present the redshift distribution of a complete, unbiased sample of 24
micron sources down to fnu(24 micron) = 300 uJy (5-sigma). The sample consists
of 591 sources detected in the Bootes field of the NOAO Deep Wide-Field Survey.
We have obtained optical spectroscopic redshifts for 421 sources (71%). These
have a redshift distribution peaking at z~0.3, with a possible additional peak
at z~0.9, and objects detected out to z=4.5. The spectra of the remaining 170
(29%) exhibit no strong emission lines from which to determine a redshift. We
develop an algorithm to estimate the redshift distribution of these sources,
based on the assumption that they have emission lines but that these lines are
not observable due to the limited wavelength coverage of our spectroscopic
observations. The redshift distribution derived from all 591 sources exhibits
an additional peak of extremely luminous (L(8-1000 micron) > 3 x 10^{12} Lsun)
objects at z~2, consisting primarily of sources without observable emission
lines. We use optical line diagnostics and IRAC colors to estimate that 55% of
the sources within this peak are AGN-dominated. We compare our results to
published models of the evolution of infrared luminous galaxies. The models
which best reproduce our observations predict a large population of
star-formation dominated ULIRGs at z > 1.5 rather than the AGN-dominated
sources we observe.


title: Successes and failures of Bethe Ansatz Density Functional Theory

abstract:
  The response of a one-dimensional fermion system is investigated using
Density Functional Theory (DFT) within the Local Density Approximation (LDA),
and compared with exact results. It is shown that DFT-LDA reproduces
surprisingly well some of the characteristic features of the Luttinger liquid,
namely the vanishing spectral weight of low energy particle-hole excitations,
as well as the dispersion of the collective charge excitations. On the other
hand, the approximation fails, even qualitatively, for quantities for which
backscattering is important, i.e., those quantities which are crucial for an
accurate description of transport. In particular, the Drude weight in the
presence of a single impurity is discussed.


title: Ballot theorems for random walks with finite variance

abstract:
  We prove an analogue of the classical ballot theorem that holds for any
random walk in the range of attraction of the normal distribution. Our result
is best possible: we exhibit examples demonstrating that if any of our
hypotheses are removed, our conclusions may no longer hold.


title:
Nonextensivity and q-distribution of a relativistic gas under an
  external electromagnetic field

abstract:
  We investigate the nonextensivity and the q-distribution of a relativistic
gas under an external electromagnetic field. We derive a formula expression of
the nonextensive parameter q based on the relativistic generalized Boltzmann
equation, the relativistic q-H theorem and the relativistic version of
q-power-law distribution function in the nonextensive q-kinetic theory. We thus
provide the connection between the parameter 1-q and the differentiation of the
temperature field of the gas as well as the four-potential with respect to time
and space coordinates, and therefore present the nonextensivity for the gas a
clearly physical meaning.


title: Suppressing the spurious states of the centre of mass

abstract:
  Following Dirac's ideas concerning the quantization of constrained systems,
we suggest to replace the free centre of mass Hamiltonian H_{CM} by another
operator which commutes with all the elements of the algebra generated via the
commutation relations by H_{CM} and the constraints which fix the centre of
mass position. We show that the new Hamiltonian is a multiple of the identity
operator and, as a result, its unique effect is to raise the internal energy
levels by a constant amount.


title:
Observation of a Universal Aggregation Mechanism and a Possible Phase
  Transition in Au Sputtered by Swift Heavy Ions

abstract:
  Two exponents, $\delta$, for size distribution of $n$-atom clusters,
$Y(n)\sim n^{-\delta}$, have been found in Au clusters sputtered from embedded
Au nanoparticles under swift heavy ion irradiation. For small clusters, below
12.5 nm in size, $\delta$ has been found to be 3/2, which can be rationalized
as occurring from a steady state aggregation process with size independent
aggregation. For larger clusters, a $\delta$ value of 7/2 is suggested, which
might come from a dynamical transition to another steady state where
aggregation and evaporation rates are size dependent. In the present case, the
observed decay exponents do not support any possibility of a thermodynamic
liquid-gas type phase transition taking place, resulting in cluster formation.


title: Construction of a stationary FIFO queue with impatient customers

abstract:
  In this paper, we study the stability of queues with impatient customers.
Under general stationary ergodic assumptions, we first provide some conditions
for such a queue to be regenerative (i.e. to empty a.s. an infinite number of
times). In the particular case of a single server operating in First in, First
out, we prove the existence (in some cases, on an enlarged probability space)
of a stationary workload. This is done by studying stochastic recursions under
the Palm settings, and by stochastic comparison of stochastic recursions.


title: New overlap construction of Weyl fermions

abstract:
  In a recent article Hasenfratz and von Allmen have suggested a fixed point
action for two flavors of Weyl fermions on the lattice with gauge group SU(2).
The block-spin transformation they use maps the chiral and vector symmetries of
the underlying vector theory onto two equations of the Ginsparg-Wilson (GW)
type. We show that an overlap Dirac operator can be constructed which solves
both GW equations simultaneously. We discuss the properties of this overlap
operator and its projection onto lattice Weyl fermions which seems to be free
of artefacts, in particular the projection operators are independent of the
gauge field.


title: Evolution of Unmagnetized and Magnetized Shear Layers

abstract:
  We present numerical simulations of the growth and saturation of the
Kelvin-Helmholtz instability in a compressible fluid layer with and without a
weak magnetic field. In the absence of a magnetic field, the instability
generates a single eddy which flattens the velocity profile, stabilizing it
against further perturbations. Adding a weak magnetic field - weak in the sense
that it has almost no effect on the linear instability - leads to a complex
flow morphology driven by MHD forces and to enhanced broadening of the layer,
due to Maxwell stresses. We corroborate earlier studies which showed that
magnetic fields destroy the large scale eddy structure through periodic cycles
of windup and resistive decay, but we show that the rate of decay decreases
with decreasing plasma resistivity, at least within the range of resistivity
accessible to our simulations. Magnetization increases the efficiency of
momentum transport, and the transport increases with decreasing resistivity.


title:
Ultracold bosons in disordered superlattices: Mott-insulators induced by
  tunneling

abstract:
  We analyse the phase diagram of ultra-cold bosons in a one-dimensional
superlattice potential with disorder using the time evolving block decimation
algorithm for infinite sized systems (iTEBD). For degenerate potential energies
within the unit cell of the superlattice loophole-shaped insulating phases with
non-integer filling emerge with a particle-hole gap proportional to the boson
hopping. Adding a small amount of disorder destroys this gap. For not too large
disorder the loophole Mott regions detach from the axis of vanishing hopping
giving rise to insulating islands. Thus the system shows a transition from a
compressible Bose-glass to a Mott-insulating phase with increasing hopping
amplitude. We present a straight forward effective model for the dynamics
within a unit cell which provides a simple explanation for the emergence of
Mott-insulating islands. In particular it gives rather accurate predictions for
the inner critical point of the Bose-glass to Mott-insulator transition.


title:
Measurement of Azimuthal Asymmetries With Respect To Both Beam Charge
  and Transverse Target Polarization in Exclusive Electroproduction of Real
  Photons

abstract:
  Azimuthal asymmetries in exclusive electroproduction of real photons are
measured for the first time with respect to transverse target polarisation,
providing new constraints on Generalized Parton Distributions. From the same
data set on a hydrogen target, new results for the beam-charge asymmetry are
also extracted with better precision than those previously reported. By
comparing model calculations with measured asymmetries attributed to the
interference between the deeply virtual Compton scattering and Bethe-Heitler
processes, a model-dependent constraint is obtained on the total angular
momenta carried by up and down quarks in the nucleon.


title:
Density fluctuations and a first-order chiral phase transition in
  non-equilibrium

abstract:
  The thermodynamics of a first-order chiral phase transition is considered in
the presence of spinodal phase separation using the Nambu-Jona-Lasinio model in
the mean field approximation. We focus on the behavior of conserved charge
fluctuations. We show that in non-equilibrium the specific heat and charge
susceptibilities diverge as the system crosses the isothermal spinodal lines.


title:
Numerical simulations of type III planetary migration: III. Outward
  migration of massive planets

abstract:
  We present a numerical study of rapid, so called type III migration for
Jupiter-sized planets embedded in a protoplanetary disc. We limit ourselves to
the case of outward migration, and study in detail its evolution and physics,
concentrating on the structure of the co-rotation and circumplanetary regions,
and processes for stopping migration. We also consider the dependence of the
migration behaviour on several key parameters. We perform this study using
global, two-dimensional hydrodynamical simulations with adaptive mesh
refinement. We find that the outward directed type III migration can be started
if the initial conditions support $Z > 1$, that corresponds to initial value
$M_\rmn{\Delta} \ga 1.5$. Unlike the inward directed migration, in the outward
migration the migration rate increases due to the growing of the volume of the
co-orbital region. We find the migration to be strongly dependent on the rate
of the mass accumulation in the circumplanetary disc, leading to two possible
regimes of migration, fast and slow. The structure of the co-orbital region and
the stopping mechanism differ between these two regimes.


title:
Non equilibrium dynamics of disordered systems : understanding the broad
  continuum of relevant time scales via a strong-disorder RG in configuration
  space

abstract:
  We show that an appropriate description of the non-equilibrium dynamics of
disordered systems is obtained through a strong disorder renormalization
procedure in {\it configuration space}, that we define for any master equation
with transitions rates $W ({\cal C} \to {\cal C}')$ between configurations. The
idea is to eliminate iteratively the configuration with the highest exit rate
$W_{out} ({\cal C})= \sum_{{\cal C}'} W ({\cal C} \to {\cal C}')$ to obtain
renormalized transition rates between the remaining configurations. The
multiplicative structure of the new generated transition rates suggests that,
for a very broad class of disordered systems, the distribution of renormalized
exit barriers defined as $B_{out} ({\cal C}) \equiv - \ln W_{out}({\cal C})$
will become broader and broader upon iteration, so that the strong disorder
renormalization procedure should become asymptotically exact at large time
scales. We have checked numerically this scenario for the non-equilibrium
dynamics of a directed polymer in a two dimensional random medium.


title: Island formation without attractive interactions

abstract:
  We show that adsorbates on surfaces can form islands even if there are no
attractive interactions. Instead strong repulsion between adsorbates at short
distances can lead to islands, because such islands increase the entropy of the
adsorbates that are not part of the islands. We suggest that this mechanism
cause the observed island formation in O/Pt(111), but it may be important for
many other systems as well.


title: An introduction to many worlds in quantum computation

abstract:
  The interpretation of quantum mechanics is an area of increasing interest to
many working physicists. In particular, interest has come from those involved
in quantum computing and information theory, as there has always been a strong
foundational element in this field. This paper introduces one interpretation of
quantum mechanics, a modern `many-worlds' theory, from the perspective of
quantum computation. Reasons for seeking to interpret quantum mechanics are
discussed, then the specific `neo-Everettian' theory is introduced and its
claim as the best available interpretation defended. The main objections to the
interpretation, including the so-called ``problem of probability'' are shown to
fail. The local nature of the interpretation is demonstrated, and the
implications of this both for the interpretation and for quantum mechanics more
generally are discussed. Finally, the consequences of the theory for quantum
computation are investigated, and common objections to using many worlds to
describe quantum computing are answered. We find that using this particular
many-worlds theory as a physical foundation for quantum computation gives
several distinct advantages over other interpretations, and over not
interpreting quantum theory at all.


title:
SU(2) Symmetry and Degeneracy From SUSY QM of a Neutron in the Magnetic
  Field of a Linear Current

abstract:
  From SUSY ladder operators in momentum space of a neutron in the magnetic
field of a linear current, we construct $2\times 2$ matrix operators that
together with the z-component of the angular momentum satisfy the su(2) Lie
algebra. We use this fact to explain the degeneracy of the energy spectrum.


title: Discovery of a Very Bright Strongly-Lensed Galaxy Candidate at z ~ 7.6

abstract:
  Using HST and Spitzer IRAC imaging, we report the discovery of a very bright
strongly lensed Lyman break galaxy (LBG) candidate at z~7.6 in the field of the
massive galaxy cluster Abell 1689. The galaxy candidate, which we refer to as
A1689-zD1, shows a strong z-J break of at least 2.2 mag and is completely
undetected (<1 sigma) in HST/ACS g, r, i, and z-band data. These properties,
combined with the very blue J-H and H-[4.5] colors, are exactly the properties
of an z~7.6 LBG and can only be reasonably fit by a star-forming galaxy at
z=7.6 +/- 0.4. Attempts to reproduce these properties with a model galaxy at
z<4 yield particularly poor fits. A1689-zD1 has an observed (lensed) magnitude
of 24.7 AB (8 sigma) in the NICMOS H band and is ~1.3 mag brighter than the
brightest-known z-dropout galaxy. When corrected for the cluster magnification
of 9.3 at z~7.6, the candidate has an intrinsic magnitude of H=27.1 AB, or
about an L* galaxy at z~7.6. The source-plane deprojection shows that the star
formation is occurring in compact knots of size ~<300 pc. The best-fit stellar
population synthesis models yield a median redshift of 7.6, stellar masses
(1.6-3.9) x 10^9 M_sun, stellar ages 45-320 Myr, star-formation rates ~<7.6
M_sun/yr, and low reddening with A_V <= 0.3. These properties are generally
similar to those of LBGs found at z~5-6. The inferred stellar ages suggest a
formation redshift of z~8-10 (t~<0.63 Gyr). A1689-zD1 is the brightest
observed, highly reliable z>7.0 galaxy candidate found to date.


title:
Surface roughness influence on the quality factor of high frequency
  nanoresonators

abstract:
  Surface roughness influences significantly the quality factor of high
frequency nanoresonators for large frequency - relaxation times within the
non-Newtonian regime, where a purely elastic dynamics develops. It is shown
that the influence of sort wavelength roughness, which is expressed by the
roughness exponent H for the case of self-affine roughness, plays significant
role in comparison with the effect of the long wavelength roughness parameters
such as the rms roughness amplitude and the lateral roughness correlation
length. Therefore, the surface morphology can play important role in designing
high-frequency resonators operating within the non-Newtonian regime.


title:
Criticality of spreading dynamics in hierarchical cluster networks
  without inhibition

abstract:
  An essential requirement for the representation of functional patterns in
complex neural networks, such as the mammalian cerebral cortex, is the
existence of stable network activations within a limited critical range. In
this range, the activity of neural populations in the network persists between
the extremes of quickly dying out, or activating the whole network. The nerve
fiber network of the mammalian cerebral cortex possesses a modular organization
extending across several levels of organization. Using a basic spreading model
without inhibition, we investigated how functional activations of nodes
propagate through such a hierarchically clustered network. The simulations
demonstrated that persistent and scalable activation could be produced in
clustered networks, but not in random networks of the same size. Moreover, the
parameter range yielding critical activations was substantially larger in
hierarchical cluster networks than in small-world networks of the same size.
These findings indicate that a hierarchical cluster architecture may provide
the structural basis for the stable and diverse functional patterns observed in
cortical networks.


title:
Optical Surface Brightness Fluctuations of shell galaxies towards 100
  Mpc

abstract:
  We measure F814W Surface Brightness Fluctuations (SBF) for a sample of
distant shell galaxies with radial velocities ranging from 4000 to 8000 km/s.
The distance at galaxies is then evaluated by using the SBF method. For this
purpose, theoretical SBF magnitudes for the ACS@HST filters are computed for
single burst stellar populations covering a wide range of ages (t=1.5-14 Gyr)
and metallicities (Z=0.008-0.04). Using these stellar population models we
provide the first $\bar{M}_{F814W}$ versus $(F475W-F814W)_0$ calibration and we
extend the previous I-band versus $(B-I)_0$ color relation to colors
$(B-I)_{0}\leq 2.0$ mag. Coupling our SBF measurements with the theoretical
calibration we derive distances with a statistical uncertainty of $\sim 8%$,
and systematic error of $\sim 6 %$. The procedure developed to analyze data
ensures that the indetermination due to possible unmasked residual shells is
well below $\sim 12 %$. The results suggest that \emph{optical} SBFs can be
measured at $d \geq 100 Mpc$ with ACS@HST imaging. SBF-based distances coupled
with recession velocities corrected for peculiar motion, allow us obtain $H_{0}
= 76 \pm 6$ (statistical) $\pm 5$ (systematic) km/s/Mpc.


title: Some consequences of a Higgs triplet

abstract:
  We consider an extension of the scalar sector of the Standard Model with a
single complex Higgs triplet $X$. Such extensions are the most economic,
model-independent way of generating neutrino masses through triplet
interactions. We show that a term like $\azero\Phi\Phi X^\dag$ must be included
in the most general potential of such a scenario, in order to avoid a massless
neutral physical scalar. We also demonstrate that $\azero$ must be real, thus
ruling out any additional source of CP-violation. We then examine the
implications of this term in the mass matrices of the singly-and doubly-charged
scalar, neutral scalar and pseudoscalar fields. We find that, for small values
of $\azero/\vtwo$, where $\vtwo$ is the triplet vev, the spectrum allows the
decay of heavier scalars into lighter ones via gauge interactions. For large
$\azero/\vtwo$, the doubly-charged, singly-charged and neutral pseudoscalar
bosons become practically degenerate, while the even-parity neutral scalars
remain considerably lighter, thus emphasizing the possibility of decay of the
singly-charged or neutral pseudoscalar states into the neutral scalars.
Constraints from the $\rho$-parameter are used to find nontrivial limits on the
charged Higgs mass depending on $\azero$. We also study the couplings of the
various physical states in this scenario. For small values of $|\azero|/\vtwo$,
we find the lightest neutral scalar field to be triplet-dominated, and thus
having extremely suppressed interactions with fermion as well as gauge boson
pairs.


title:
Developmental time windows for spatial growth generate multiple-cluster
  small-world networks

abstract:
  Many networks extent in space, may it be metric (e.g. geographic) or
non-metric (ordinal). Spatial network growth, which depends on the distance
between nodes, can generate a wide range of topologies from small-world to
linear scale-free networks. However, networks often lacked multiple clusters or
communities. Multiple clusters can be generated, however, if there are time
windows during development. Time windows ensure that regions of the network
develop connections at different points in time. This novel approach could
generate small-world but not scale-free networks. The resulting topology
depended critically on the overlap of time windows as well as on the position
of pioneer nodes.


title:
Mean clustering coefficients: the role of isolated nodes and leafs on
  clustering measures for small-world networks

abstract:
  Many networks exhibit the small-world property of the neighborhood
connectivity being higher than in comparable random networks. However, the
standard measure of local neighborhood clustering is typically not defined if a
node has one or no neighbors. In such cases, local clustering has traditionally
been set to zero and this value influenced the global clustering coefficient.
Such a procedure leads to underestimation of the neighborhood clustering in
sparse networks. We propose to include $\theta$ as the proportion of leafs and
isolated nodes to estimate the contribution of these cases and provide a
formula for estimating a clustering coefficient excluding these cases from the
Watts and Strogatz (1998 Nature 393 440-2) definition of the clustering
coefficient. Excluding leafs and isolated nodes leads to values which are up to
140% higher than the traditional values for the observed networks indicating
that neighborhood connectivity is normally underestimated. We find that the
definition of the clustering coefficient has a major effect when comparing
different networks. For metabolic networks of 43 organisms, relations changed
for 58% of the comparisons when a different definition was applied. We also
show that the definition influences small-world features and that the
classification can change from non-small-world to small-world network. We
discuss the use of an alternative measure, disconnectedness D, which is less
influenced by leafs and isolated nodes.


title: Oscillations of Mossbauer neutrinos

abstract:
  We calculate the probability of recoilless emission and detection of
neutrinos (Mossbauer effect with neutrinos) taking into account the boundedness
of the parent and daughter nuclei in the neutrino source and detector as well
as the leptonic mixing. We show that, in spite of their near monochromaticity,
the recoillessly emitted and captured neutrinos oscillate. After a qualitative
discussion of this issue, we corroborate and extend our results by computing
the combined rate of $\bar{\nu}_e$ production, propagation and detection in the
framework of quantum field theory, starting from first principles. This allows
us to avoid making any a priori assumptions about the energy and momentum of
the intermediate-state neutrino. Our calculation permits quantitative
predictions of the transition rate in future experiments, and shows that the
decoherence and delocalization factors, which could in principle suppress
neutrino oscillations, are irrelevant under realistic experimental conditions.


title:
First identification of large electric monopole strength in
  well-deformed rare earth nuclei

abstract:
  Excited states in the well-deformed rare earth isotopes $^{154}$Sm and
$^{166}$Er were populated via ``safe'' Coulomb excitation at the Munich MLL
Tandem accelerator. Conversion electrons were registered in a cooled Si(Li)
detector in conjunction with a magnetic transport and filter system, the
Mini-Orange spectrometer. For the first excited $0^+$ state in $^{154}$Sm at
1099 keV a large value of the monopole strength for the transition to the
ground state of $\rho^2(\text{E0}; 0^+_2 \to 0^+_\text{g}) = 96(42)\cdot
10^{-3}$ could be extracted. This confirms the interpretation of the lowest
excited $0^+$ state in $^{154}$Sm as the collective $\beta$-vibrational
excitation of the ground state. In $^{166}$Er the measured large electric
monopole strength of $\rho^2(\text{E0}; 0^+_4 \to 0^+_1) = 127(60)\cdot
10^{-3}$ clearly identifies the $0_4^+$ state at 1934 keV to be the
$\beta$-vibrational excitation of the ground state.


title: Re-classification of the alleged quasar Q0045-3337

abstract:
  We present a medium-resolution optical spectrum of the alleged high-redshift
quasar Q0045-3337, taken at the ESO/3.6m telescope. Our observations show that
the object is not a quasar but a star of spectral type B. We suggest that the
object is either a white dwarf or a halo population Blue Horizontal Branch
star.


title: The Role of Bound States in Time-Dependent Quantum Transport

abstract:
  Charge transport through a nanoscale junction coupled to two macroscopic
electrodes is investigated for the situation when bound states are present. We
provide numerical evidence that bound states give rise to persistent,
non-decaying current oscillations in the junction. We also show that the
amplitude of these oscillations can exhibit a strong dependence on the history
of the applied potential as well as on the initial equilibrium configuration.
Our simulations allow for a quantitative investigation of several transient
features. We also discuss the existence of different time-scales and address
their microscopic origin.


title: Approximation using scattered shifts of a multivariate function

abstract:
  The approximation of a general $d$-variate function $f$ by the shifts
$\phi(\cdot-\xi)$, $\xi\in\Xi\subset \Rd$, of a fixed function $\phi$ occurs in
many applications such as data fitting, neural networks, and learning theory.
When $\Xi=h\Z^d$ is a dilate of the integer lattice, there is a rather complete
understanding of the approximation problem \cite{BDR,Johnson1} using Fourier
techniques. However, in most applications the {\it center} set $\Xi$ is either
given, or can be chosen with complete freedom. In both of these cases, the
shift-invariant setting is too restrictive. This paper studies the
approximation problem in the case $\Xi$ is arbitrary. It establishes
approximation theorems whose error bounds reflect the local density of the
points in $\Xi$. Two different settings are analyzed. The first is when the set
$\Xi$ is prescribed in advance. In this case, the theorems of this paper show
that, in analogy with the classical univariate spline approximation, improved
approximation occurs in regions where the density is high. The second setting
corresponds to the problem of non-linear approximation. In that setting the set
$\Xi$ can be chosen using information about the target function $f$. We discuss
how to `best' make these choices and give estimates for the approximation
error.


title:
Retrieval of interatomic separations of molecules from laser-induced
  high-order harmonic spectra

abstract:
  We illustrate an iterative method for retrieving the internuclear separations
of N$_2$, O$_2$ and CO$_2$ molecules using the high-order harmonics generated
from these molecules by intense infrared laser pulses. We show that accurate
results can be retrieved with a small set of harmonics and with one or few
alignment angles of the molecules. For linear molecules the internuclear
separations can also be retrieved from harmonics generated using isotropically
distributed molecules. By extracting the transition dipole moment from the
high-order harmonic spectra, we further demonstrated that it is preferable to
retrieve the interatomic separation iteratively by fitting the extracted dipole
moment. Our results show that time-resolved chemical imaging of molecules using
infrared laser pulses with femtosecond temporal resolutions is possible.


title: Coherent meta-materials and the lasing spaser

abstract:
  In 2003 Bergman and Stockman introduced the spaser, a quantum amplifier of
surface plasmons by stimulated emission of radiation [1]. They argued that, by
exploiting a metal/dielectric composite medium, it should be possible to
construct a nano-device, where a strong coherent field is built up in a spatial
region much smaller than the wavelength [1,2]. V-shaped metallic inclusion,
combined with a collection of semiconductor quantum dots were discussed as a
possible realization of the spaser [1]. Here we introduce a further development
of the spaser concept. We show that by combining the metamaterial and spaser
ideas one can create a narrow-diversion coherent source of electromagnetic
radiation that is fuelled by plasmonic oscillations. We argue that
two-dimensional arrays of a certain class of plasmonic resonators supporting
high-Q coherent current excitations provide an intriguing opportunity to create
spatially and temporally coherent laser source, the Lasing Spaser.


title:
Binary Black Hole Encounters, Gravitational Bursts and Maximum Final
  Spin

abstract:
  The spin of the final black hole in the coalescence of nonspinning black
holes is determined by the ``residual'' orbital angular momentum of the binary.
This residual momentum consists of the orbital angular momentum that the binary
is not able to shed in the process of merging. We study the angular momentum
radiated, the spin of the final black hole and the gravitational bursts in a
series of orbits ranging from almost direct infall to numerous orbits before
infall that exhibit multiple bursts of radiation in the merger process. We show
that the final black hole gets a maximum spin parameter $a/M_h \le 0.78$, and
this maximum occurs for initial orbital angular momentum $L \approx M^2_h$.


title: Nonlocal surface dipoles and vortices

abstract:
  We predict the existence and address the stability of two-dimensional surface
solitons featuring topologically complex shapes, including dipoles, vortices,
and bound states of vortex solitons, at the interface of nonlocal thermal
media. Unlike their counterparts in bulk media, surface dipoles are found to be
stable in the entire existence domain. Surface vortices are found to exhibit
strongly asymmetric intensity and phase distributions, and are shown to be
stable, too. Bound states of surface vortex solitons belong to a novel class of
surface solitons having no counterparts in bulk media. Such states are found to
be stable provided that their energy flow does not exceed an upper threshold.
Our findings constitute the first known example of topologically complex
solitons located at nonlocal two-dimensional interfaces.


title: The Dark UNiverse Explorer (DUNE): Proposal to ESA's Cosmic Vision

abstract:
  The Dark UNiverse Explorer (DUNE) is a wide-field space imager whose primary
goal is the study of dark energy and dark matter with unprecedented precision.
For this purpose, DUNE is optimised for the measurement of weak gravitational
lensing but will also provide complementary measurements of baryonic accoustic
oscillations, cluster counts and the Integrated Sachs Wolfe effect. Immediate
auxiliary goals concern the evolution of galaxies, to be studied with
unequalled statistical power, the detailed structure of the Milky Way and
nearby galaxies, and the demographics of Earth-mass planets. DUNE is an
Medium-class mission which makes use of readily available components, heritage
from other missions, and synergy with ground based facilities to minimise cost
and risks. The payload consists of a 1.2m telescope with a combined visible/NIR
field-of-view of 1 deg^2. DUNE will carry out an all-sky survey, ranging from
550 to 1600nm, in one visible and three NIR bands which will form a unique
legacy for astronomy. DUNE will yield major advances in a broad range of fields
in astrophysics including fundamental cosmology, galaxy evolution, and
extrasolar planet search. DUNE was recently selected by ESA as one of the
mission concepts to be studied in its Cosmic Vision programme.


title: An oscillating Universe from the linearized R^{2} theory of gravity

abstract:
  An oscillating Universe which arises from the linearized R^{2} theory of
gravity is discussed, showing that some observative evidences like the
cosmological redshift and the Hubble law are in agreement with the model. In
this context Dark Energy is seen like a pure curvature effect arising by the
Ricci scalar.


title: Time Distance Study of Isolated Sunspots

abstract:
  We present a comparative seismic study of conditions around and beneath
isolated sunspots. Using the European Grid of Solar Observations' Solar Feature
Catalogue of sunspots derived from SOHO/MDI continuum and magnetogram data,
1996-2005, we identify a set of isolated sunspots by checking that within a
Carrington Rotation there were no other spots detected in the vicinity. We then
use level-2 tracked MDI Dopplergrams available from SOHO website to investigate
wave-speed perturbations of such sunspots using time-distance helioseismology.


title: Towards an understanding of the RHIC single electron data

abstract:
  High transverse momentum ($p_T$) single non-photonic electrons which have
been measured in the RHIC experiments come dominantly from heavy meson decay.
The ratio of their $p_T$ spectra in pp and AA collisions ($R_{AA}(p_T)$)
reveals the energy loss of heavy quarks in the environment created by AA
collisions. Using a fixed coupling constant and the Debye mass ($m_D\approx
gT$) as infrared regulator perturbative QCD (pQCD) calculations are not able to
reproduce the data, neither the energy loss nor the azimuthal $(v_2)$
distribution. Employing a running coupling constant and replacing the Debye
mass by a more realistic hard thermal loop (HTL) calculation we find a
substantial increase of the collisional energy loss which brings the $v_2(p_T)$
distribution as well as $R_{AA}(p_T)$ to values close to the experimental ones
without excluding a contribution from radiative energy loss.


title:
Bistable MAP Kinase Activity: A Plausible Mechanism Contributing to
  Maintenance of Late Long-Term Potentiation

abstract:
  Bistability of MAP kinase (MAPK) activity has been suggested to contribute to
several cellular processes, including differentiation and long-term synaptic
potentiation. A recent model (48) predicts bistability due to interactions of
the kinases and phosphatases in the MAPK pathway, without feedback from MAPK to
earlier reactions. Using this model and enzyme concentrations appropriate for
neurons, we simulated bistable MAPK activity, but bistability only was present
within a relatively narrow range of activity of Raf, the first pathway kinase.
Stochastic fluctuations in molecule numbers eliminated bistability for small
molecule numbers, such as are expected in the volume of a dendritic spine.
However, positive feedback loops have been posited from MAPK up to Raf
activation. One proposed loop in which MAPK directly activates Raf was
incorporated into the model. We found that such feedback greatly enhanced the
robustness of both stable states of MAPK activity to stochastic fluctuations
and to parameter variations. Bistability was robust for molecule numbers
plausible for a dendritic spine volume. The upper state of MAPK activity was
resistant to inhibition of MEK activation for > 1 h, suggesting inhibitor
experiments have not sufficed to rule out a role for persistent MAPK activity
in LTP maintenance. These simulations suggest that persistent MAPK activity and
consequent upregulation of translation may contribute to LTP maintenance and to
long-term memory. Experiments using a fluorescent MAPK substrate may further
test this hypothesis.


title: Asymptotics and Hamiltonians in a First order formalism

abstract:
  We consider 4-dimensional space-times which are asymptotically flat at
spatial infinity and show that, in the first order framework, action principle
for general relativity is well-defined \emph{without the need of infinite
counter terms.} It naturally leads to a covariant phase space in which the
Hamiltonians generating asymptotic symmetries provide the total energy-momentum
and angular momentum of the space-time. We address the subtle but important
problems that arise because of logarithmic translations and super-translations
both in the Langrangian and Hamiltonian frameworks. As a forthcoming paper will
show, the treatment of higher dimensions is considerably simpler. Our first
order framework also suggests a new direction for generalizing the spectral
action of non-commutative geometry.


title: Min-Cost 2-Connected Subgraphs With k Terminals

abstract:
  In the k-2VC problem, we are given an undirected graph G with edge costs and
an integer k; the goal is to find a minimum-cost 2-vertex-connected subgraph of
G containing at least k vertices. A slightly more general version is obtained
if the input also specifies a subset S \subseteq V of terminals and the goal is
to find a subgraph containing at least k terminals. Closely related to the
k-2VC problem, and in fact a special case of it, is the k-2EC problem, in which
the goal is to find a minimum-cost 2-edge-connected subgraph containing k
vertices. The k-2EC problem was introduced by Lau et al., who also gave a
poly-logarithmic approximation for it. No previous approximation algorithm was
known for the more general k-2VC problem. We describe an O(\log n \log k)
approximation for the k-2VC problem.


title:
Molecular Dynamics Computer Simulation of Crystal Growth and Melting in
  Al50Ni50

abstract:
  The melting and crystallization of Al50Ni50} are studied by means of
molecular dynamics computer simulations, using a potential of the embedded atom
type to model the interactions between the particles. Systems in a slab
geometry are simulated where the B2 phase of AlNi in the middle of an elongated
simulation box is separated by two planar interfaces from the liquid phase,
thereby considering the (100) crystal orientation. By determining the
temperature dependence of the interface velocity, an accurate estimate of the
melting temperature is provided. The value k=0.0025 m/s/K for the kinetic
growth coefficient is found. This value is about two orders of magnitude
smaller than that found in recent simulation studies of one-component metals.
The classical Wilson-Frenkel model is not able to describe the crystal growth
kinetics on a quantitative level. We argue that this is due to the neglect of
diffusion processes in the liquid-crystal interface.


title:
Resonance sum rules from large $N_C$ and partial wave dispersive
  analysis

abstract:
  Combining large $N_C$ techniques and partial wave dispersion theory to
analyze the $\pi\pi$ scattering, without relying on any explicit resonance
lagrangian, some interesting results are derived: (a) a general KSRF relation
including the scalar meson contribution; (b) a new relation between resonance
couplings, with which we have made an intensive analysis in several specific
models; (c) low energy constants in chiral perturbation theory related with
$\pi\pi$ scattering in terms of the mass and decay width of resonances.


title:
Ab-initio determined electronic and magnetic properties of half-metallic
  NiCrSi and NiMnSi Heusler alloys; the role of interfaces and defects

abstract:
  Using state-of-the-art first-principles calculations we study the properties
of the ferromagnetic Heusler compounds NiYSi where Y stands for V, Cr or Mn.
NiCrSi and NiMnSi contrary to NiVSi are half-metallic at their equilibrium
lattice constant exhibiting integer values of the total spin magnetic moment
and thus we concentrate on these two alloys. The minority-spin gap has the same
characteristics as for the well-known NiMnSb alloy being around $\sim$1 eV.
Upon tetragonalization the gap is present in the density of states even for
expansion or contraction of the out-of-plane lattice parameter by 5%. The Cr-Cr
and Mn-Mn interactions make ferromagnetism extremely stable and the Curie
temperature exceeds 1000 K for NiMnSi. Surface and interfaces with GaP, ZnS and
Si semiconductors are not half-metallic but in the case of NiCrSi the Ni-based
contacts present spin-polarization at the Fermi level over 90%. Finally, we
show that there are two cases of defects and atomic-swaps. The first-ones which
involve the Cr(Mn) and Si atoms induce states at the edges of the gap which
persists for a moderate-concentration of defects. Defects involving Ni atoms
induce states localized within the gap completely destroying the
half-metallicity. Based on single-impurity calculations we associate these
states to the symmetry of the crystal.


title:
The evidence for unusual gravity from the large-scale structure of the
  Universe

abstract:
  Under the assumption that General Relativity (GR) correctly describes the
phenomenology of our Universe, astronomical observations provide compelling
evidence that (1) the dynamics of cosmic structure is dominated by dark matter
(DM), an exotic matter mostly made of hypothetical elementary particles, and
(2) the expansion of the Universe is currently accelerating because of the
presence of a positive cosmological constant Lambda. The DM particles have not
yet been detected and there is no theoretical justification for the tiny
positive Lambda implied by observations. Therefore, over the last decade, the
search for extended or alternative theories of gravity has flourished.


title: Coloring the 600 Cell

abstract:
  The 600 cell S has exactly 10 5-colorings. From these colorings we can
construct the space of colorings $B(S)$. This complex has 1344 colorings, and
is isomorphic to the space of 5 by 5 Latin Squares. These simplices split into
4 copies of a quotient of S by an involution, and two copies of a space made up
of even Latin Squares.


title: Dark matter accretion wakes of high-redshift black holes

abstract:
  Anisotropic emission of gravitational waves during the merger or formation of
black holes can lead to the ejection of these black holes from their host
galaxies. A recoiled black hole which moves on an almost radial bound orbit
outside the virial radius of its central galaxy, in the cold dark matter
background, reaches its apapsis in a finite time. The low value of dark matter
velocity dispersion at high redshifts and also the black hole velocity near the
apapsis passage yield a high-density wake around these black holes. Gamma-ray
emission can result from the enhancement of dark matter annihilation in these
wakes. The diffuse high-energy gamma-ray background from the ensemble of such
black holes in the Hubble volume is also evaluated.


title: The origin of molecular hydrogen emission in cooling-flow filaments

abstract:
  The optical filaments found in many cooling flows in galaxy clusters consist
of low density ($\sim 10^3 \pcc$) cool ($\sim 10^3$ K) gas surrounded by
significant amounts of cosmic-ray and magnetic-field energy. Their spectra show
anomalously strong low-ionization and molecular emission lines when compared
with galactic molecular clouds exposed to ionizing radiation such as the Orion
complex. Previous studies have shown that the spectra cannot be produced by
O-star photoionization. Here we calculate the physical conditions in dusty gas
that is well shielded from external sources of ionizing photons and is
energized either by cosmic rays or dissipative MHD waves. Strong molecular
hydrogen lines, with relative intensities similar to those observed, are
produced. Selection effects introduced by the microphysics produce a
correlation between the \htwo line upper level energy and the population
temperature. These selection effects allow a purely collisional gas to produce
\htwo emission that masquerades as starlight-pumped \htwo but with intensities
that are far stronger. This physics may find application to any environment
where a broad range of gas densities or heating rates occur.


title: Lorentz symmetry violation and the results of the AUGER experiment

abstract:
  We briefly discuss the implications of recent AUGER results for patterns of
Lorentz symmetry violation (LSV), assuming that the existence of the
Greisen-Zatsepin-Kuzmin cutoff is definitely confirmed. The mass composition of
the highest-energy cosmic-ray spectrum is a crucial issue. In any case, the new
data allow in principle to exclude a significant range of LSV models but leave
open several important possibilities : a weaker Lorentz breaking, a fundamental
scale beyond the Planck scale, scenarios with threshold effects... It may even
happen that spontaneous decays due to LSV fake the GZK cutoff. Space
experiments appear to be needed to further test special relativity. We also
comment on the consequences of AUGER data for superbradyons. If such particles
are present in the Universe, they may provide new forms of dark matter and dark
energy.


title: On relativistic elements of reality

abstract:
  Several arguments have been proposed some years ago, attempting to prove the
impossibility of defining Lorentz-invariant elements of reality. I find that a
sufficient condition for the existence of elements of reality, introduced in
these proofs, seems to be used also as a necessary condition. I argue that
Lorentz-invariant elements of reality can be defined but, as Vaidman pointed
out, they won't satisfy the so-called product rule. In so doing I obtain
algebraic constraints on elements of reality associated with a maximal set of
commuting Hermitian operators.


title:
Note on the oblate and prolate deformations in nuclear matter from the
  viewpoint of the quantum-mechanical off-center effect

abstract:
  We consider the possibility that a quantum-mechanical off-center effect may
be behind the deformed oblate and prolate shapes of nuclei in nuclear physics.
In solid state physics, finite off-center displacements result from the mixing
of electronic states through their coupling to vibrational (phonon) modes of
appropriate symmetries. This is an example of fermion-boson interaction which
may materialize in nuclear physics as well in the form of a coupling of
nucleons to the pi-meson field. We carry out calculations to substantiate the
proposal.


title:
Inelastic neutron scattering studies of Crystal Field Levels in
  PrOs$_4$As$_{12}$

abstract:
  We use neutron scattering to study the Pr$^{3+}$ crystalline electric field
(CEF) excitations in the filled skutterudite PrOs$_4$As$_{12}$. By comparing
the observed levels and their strengths under neutron excitation with the
theoretical spectrum and neutron excitation intensities, we identify the
Pr$^{3+}$ CEF levels, and show that the ground state is a magnetic
$\Gamma_4^{(2)}$ triplet, and the excited states $\Gamma_1$, $\Gamma_4^{(1)}$
and $\Gamma_{23}$ are at 0.4, 13 and 23 meV, respectively. A comparison of the
observed CEF levels in PrOs$_4$As$_{12}$ with the heavy fermion superconductor
PrOs$_4$Sb$_{12}$ reveals the microscopic origin of the differences in the
ground states of these two filled skutterudites.


title: IceTop - Cosmic Ray Physics with IceCube

abstract:
  The IceCube experiment at South Pole consists of two detector components -
the IceTop air shower array on the surface and the neutrino telescope at depths
from 1450 m to 2450 m below. Currently, 26 IceTop stations and 22 InIce strings
are deployed. With the present size of the IceTop array, it is possible to
measure cosmic rays with energies ranging from 0.5 to 100 PeV. Coincident
events between the IceTop and the InIce detector provide useful cross-checks of
the detector performance and furthermore make it possible to study the
cosmic-ray composition. This paper gives an overview on the current status of
IceTop.


title:
Coarse embeddings into a Hilbert space, Haagerup Property and Poincare
  inequalities

abstract:
  We prove that a metric space does not coarsely embed into a Hilbert space if
and only if it satisfies a sequence of Poincar\'e inequalities, which can be
formulated in terms of (generalized) expanders. We also give quantitative
statements, relative to the compression. In the equivariant context, our result
says that a group does not have the Haagerup property if and only if it has
relative property T with respect to a family of probabilities whose supports go
to infinity. We give versions of this result both in terms of unitary
representations, and in terms of affine isometric actions on Hilbert spaces.