title:
Driving-dependent damping of Rabi oscillations in two-level
  semiconductor systems

abstract:
  We propose a mechanism to explain the nature of the damping of Rabi
oscillations with increasing driving-pulse area in localized semiconductor
systems, and have suggested a general approach which describes a coherently
driven two-level system interacting with a dephasing reservoir. Present
calculations show that the non-Markovian character of the reservoir leads to
the dependence of the dephasing rate on the driving-field intensity, as
observed experimentally. Moreover, we have shown that the damping of Rabi
oscillations might occur as a result of different dephasing mechanisms for both
stationary and non-stationary effects due to coupling to the environment.
Present calculated results are found in quite good agreement with available
experimental measurements.


title:
Neutrino Mixing based on Mass Matrices with a $2 \leftrightarrow 3$
  Symmetry

abstract:
  Under the assumption that the $2\leftrightarrow 3$ symmetry is broken only
through phases, we give a systematical investigation of possible lepton mass
matrix forms without referring to the explicit parameter values. The two types
of the $2\leftrightarrow 3$ symmetry are investigated: one is that the left-
and right-handed fields $(f_L, f_R)$ obey the symmetry, and another one is that
only $f_L$ obeys the symmetry. In latter case, in spite of no $2\leftrightarrow
3$ symmetry in the Majorana mass matrix $M_R$ for $\nu_R$, the neutrino seesaw
mass matrix still obey the $2\leftrightarrow 3$ symmetry. Possible
phenomenologies are discussed.


title: Filamentation instability in a quantum plasma

abstract:
  The growth rate of the filamentation instability triggered when a diluted
cold electron beam passes through a cold plasma is evaluated using the quantum
hydrodynamic equations. Compared with a cold fluid model, quantum effects
reduce both the unstable wave vector domain and the maximum growth rate.
Stabilization of large wave vector modes is always achieved, but significant
reduction of the maximum growth rate depends on a dimensionless parameter that
is provided. Although calculations are extended to the relativistic regime,
they are mostly relevant to the non-relativistic one.


title:
A Robust Linguistic Platform for Efficient and Domain specific Web
  Content Analysis

abstract:
  Web semantic access in specific domains calls for specialized search engines
with enhanced semantic querying and indexing capacities, which pertain both to
information retrieval (IR) and to information extraction (IE). A rich
linguistic analysis is required either to identify the relevant semantic units
to index and weight them according to linguistic specific statistical
distribution, or as the basis of an information extraction process. Recent
developments make Natural Language Processing (NLP) techniques reliable enough
to process large collections of documents and to enrich them with semantic
annotations. This paper focuses on the design and the development of a text
processing platform, Ogmios, which has been developed in the ALVIS project. The
Ogmios platform exploits existing NLP modules and resources, which may be tuned
to specific domains and produces linguistically annotated documents. We show
how the three constraints of genericity, domain semantic awareness and
performance can be handled all together.


title: Transmission-line networks cloaking objects from electromagnetic fields

abstract:
  We consider a novel method of cloaking objects from the surrounding
electromagnetic fields in the microwave region. The method is based on
transmission-line networks that simulate the wave propagation in the medium
surrounding the cloaked object. The electromagnetic fields from the surrounding
medium are coupled into the transmission-line network that guides the waves
through the cloak thus leaving the cloaked object undetected. The cloaked
object can be an array or interconnected mesh of small inclusions that fit
inside the transmission-line network.


title:
Discovery of the Pre-Main Sequence Population of the Stellar Association
  LH 95 in the Large Magellanic Cloud with Hubble Space Telescope ACS
  Observations

abstract:
  We report the discovery of an extraordinary number of pre-main sequence (PMS)
stars in the vicinity of the stellar association LH 95 in the Large Magellanic
Cloud (LMC). Using the {\em Advanced Camera for Surveys} on-board the {\em
Hubble} Space Telescope in wide-field mode we obtained deep high-resolution
imaging of the main body of the association and of a nearby representative LMC
background field. These observations allowed us to construct the
color-magnitude diagram (CMD) of the association in unprecedented detail, and
to decontaminate the CMD for the average LMC stellar population. The most
significant result is the direct detection of a substantial population of PMS
stars and their clustering properties with respect to the distribution of the
higher mass members of the association. Although LH 95 represents a rather
modest star forming region, our photometry, with a detection limit $V$ \lsim 28
mag, reveals in its vicinity more than 2,500 PMS stars with masses down to
$\sim 0.3$ M{\solar}. Our observations offer, thus, a new perspective of a
typical LMC association: The stellar content of LH 95 is found to extend from
bright OB stars to faint red PMS stars, suggesting a fully populated Initial
Mass Function (IMF) from the massive blue giants down to the sub-solar mass
regime.


title: Magnetic solutions in AdS$_5$ and trace anomalies

abstract:
  We discuss black hole and black string solutions in d=5 Einstein-Yang-Mills
theory with negative cosmological constant, proposing a method to compute their
mass and action. The magnetic gauge field of these configurations does not
vanish at infinity. We argue that this implies a nonvanishing trace for the
stress tensor of the dual d=4 theory.


title: Quartic equations and 2-division on elliptic curves

abstract:
  Let K be a field of characteristic different from 2 and C an elliptic curve
over K given by a Weierstrass equation. To divide an element of the group C by
2, one must solve a certain quartic equation. We characterise the quartics
arising from this procedure and find how far the quartic determines the curve
and the point. We find the quartics coming from 2-division of 2- and 3-torsion
points, and generalise this correspondence to singular plane cubics. We use
these results to study the question of which degree 4 maps of curves can be
realised as duplication of a multisection on an elliptic surface.


title: Prospects of Jet Tomography Using Hard Processes inside a Soft Medium

abstract:
  The term 'tomography' is commonly applied to the idea of studying properties
of a medium by the modifications this medium induces to a known probe
propagating through it. In the context of ultrarelativistic heavy-ion
collisions, rare high transverse momentum (p_T) processes taking place
alongside soft bulk-matter production can be viewed as a tomographic probe as
long as the energy scales are such that the modification of high p_T processes
can be dominantly ascribed to interactions with the medium during the
propagation of partons. Various high p_T observables have been suggested for
tomography, among them hard single hadron suppression, dihadron correlations
and gamma-hadron correlations. In this paper, we present a model study of a
number of different observables within the same calculational framework to
assess the sensitivity of the observables to different properties of the medium
and discuss the prospects of obtaining tomographic information.


title:
Neutrino Emission From Direct Urca Processes in Pion Condensed Quark
  Matter

abstract:
  We study neutrino emission from direct Urca processes in pion condensed quark
matter. In compact stars with high baryon density, the emission is dominated by
the gapless modes of the pion condensation which leads to an enhanced
emissivity. While for massless quarks the enhancement is not remarkable, the
emissivity is significantly larger and the cooling of the condensed matter is
considerably faster than that in normal quark matter when the mass difference
between $u$- and $d$-quarks is sizable.


title:
Inclusive Jet Production in Photon-Photon Collisions at sqrt(s_ee) from
  189 to 209 GeV

abstract:
  Inclusive jet production (e+e- -> e+e- +jet+X) is studied in collisions of
quasi-real photons radiated by the LEP beams at e+e- centre-of-mass energies
sqrt see from 189 to 209 GeV. Jets are reconstructed using the kp jet
algorithm. The inclusive differential cross-section is measured as a function
of the jet transverse momentum, ptjet, in the range 5 <ptjet < 40 GeV for
pseudo-rapidities, etaj, in the range -1.5 < etaj < 1.5. The results are
compared to predictions of perturbative QCD in next-to-leading order in the
strong coupling constant.


title: Gauge invariant Boltzmann equation and the fluid limit

abstract:
  This article investigates the collisionless Boltzmann equation up to second
order in the cosmological perturbations. It describes the gauge dependence of
the distribution function and the construction of a gauge invariant
distribution function and brightness, and then derives the gauge invariant
fluid limit.


title: Resistance without resistors: An anomaly

abstract:
  The elementary 2-terminal network consisting of a resistively ($R-$) shunted
inductance ($L$) in series with a capacitatively ($C-$) shunted resistance
($R$) with $R = \sqrt{L/C}$, is known for its non-dispersive dissipative
response, $i.e.,$ with the input impedance $Z_0(\omega) = R$, independent of
the frequency ($\omega$). In this communication we examine the properties of a
novel equivalent network derived iteratively from this 2-terminal network by
replacing everywhere the elemental resistive part $R$ with the whole 2-terminal
network. This replacement suggests a recursion $Z_{n+1}(\omega) =
f(Z_n(\omega))$, with the recursive function $f(z) = (i\omega Lz/i\omega L + z)
+ (z/1+i\omega Cz)$. The recursive map has two fixed points -- an unstable
fixed point $Z_u^\star = 0$, and a stable fixed point $Z_s^\star = R$. Thus,
resistances at the boundary terminating the infinitely iterated network can now
be made arbitrarily small without changing the input impedance $Z_\infty (=
R)$. This, therefore, leads to realizing in the limit $n\to\infty$ an
effectively dissipative network comprising essentially non-dissipative reactive
elements ($L$ and $C$) only. Hence the oxymoron -- resistance without
resistors! This is best viewed as a classical anomaly akin to the one
encountered in turbulence. Possible application as a formal decoherence device
-- the {\it fake channel} -- is briefly discussed for its quantum analogue.


title:
The chiral and flavour projection of Dirac-Kahler fermions in the
  geometric discretization

abstract:
  It is shown that an exact chiral symmetry can be described for Dirac-Kahler
fermions using the two complexes of the geometric discretization. This
principle is extended to describe exact flavour projection and it is shown that
this necessitates the introduction of a new operator and two new structures of
complex. To describe simultaneous chiral and flavour projection, eight
complexes are needed in all and it is shown that projection leaves a single
flavour of chiral field on each.


title: The order-disorder transition in colloidal suspensions under shear flow

abstract:
  We study the order-disorder transition in colloidal suspensions under shear
flow by performing Brownian dynamics simulations. We characterize the
transition in terms of a statistical property of time-dependent maximum value
of the structure factor. We find that its power spectrum exhibits the power-law
behaviour only in the ordered phase. The power-law exponent is approximately -2
at frequencies greater than the magnitude of the shear rate, while the power
spectrum exhibits the $1 / f$-type fluctuations in the lower frequency regime.


title: Particle Ratios at High p_T at LHC Energies

abstract:
  Hadron production has been calculated in a pQCD improved parton model for pp,
dA and heavy ion collisions. We applied KKP and AKK fragmentation functions.
Our jet fragmentation study shows, that hadron ratios at high p_T depend on
quark contribution mostly and less on the gluonic one. This finding can be seen
in jet-energy loss calculations, also. We display the suppression pattern on
different hadron ratios in PbPb collisions at LHC energies.


title: A precessing accretion disc in the intermediate polar XY Ari?

abstract:
  XY Ari is the only intermediate polar to show deep X-ray eclipses of its
white dwarf. Previously published observations with Ginga and Chandra have also
revealed a broad X-ray orbital modulation, roughly antiphased with the eclipse,
and presumed to be due to absorption in an extended structure near the edge of
an accretion disc. The X-ray pulse profile is generally seen to be
double-peaked, although a single-peaked pulse was seen by RXTE during an
outburst in 1996.We intended to investigate the cause of the broad orbital
modulation in XY Ari to better understand the accretion flow in this system and
other intermediate polars. We observed XY Ari with RXTE and analysed previously
unpublished archival observations of the system made with ASCA and XMM-Newton.
These observations comprise six separate visits and span about ten years. The
various X-ray observations show that the broad orbital modulation varies in
phase and significance, then ultimately disappears entirely in the last few
years. In addition, the X-ray pulse profile shows variations in depth and
shape, and in the recent RXTE observations displays no evidence for changes in
hardness ratio. The observed changes indicates that both the pulse profile and
the orbital modulation are solely due to geometrical effects at the time of the
RXTE observations, rather than phase-dependent variations in photoelectric
absorption as seen previously. We suggest that this is evidence for a
precessing, tilted accretion disc in this system. The precession of the disc
moves structures out of our line of sight both at its outer edge (changing the
orbital modulation) and at its inner edge where the accretion curtains are
anchored (changing the pulse profile).


title:
Calculation of the atmospheric muon flux motivated by the ATIC-2
  experiment

abstract:
  We calculate the cosmic ray muon flux at ground level using directly the
primary cosmic ray spectrum and composition measured in the ATIC-2 balloon
experiment. In order to extend the calculations to high energies, up to 100
TeV, we use the data of the GAMMA experiment as well as Zatsepin and Sokolskaya
model. This model, supported by the ATIC-2 data, comprises contributions to the
cosmic ray flux of three classes of astrophysical sources - the shocks from
exploding stars, nova and supernova of different types. The muon flux
computation is based on the method for solution of atmospheric hadron cascade
equations in which rising total inelastic cross-sections of hadron-nuclear
interactions as well as non-power-law character of the primary cosmic ray
spectrum are taken into account. The calculated muon spectrum agrees well with
measurements of L3+Cosmic and BESS-TeV, CAPRICE, Frejus, MACRO, LVD as well as
other experiments.


title:
On Hamiltonian stationary Lagrangian spheres in non-Einstein Kaehler
  surfaces

abstract:
  Hamiltonian stationary Lagrangian spheres in Kaehler-Einstein surfaces are
minimal. We prove that in the family of non-Einstein Kaehler surfaces given by
the product $\Sigma_1\times\Sigma_2$ of two complete orientable Riemannian
surfaces of different constant Gauss curvatures, there is only a (non minimal)
Hamiltonian stationary Lagrangian sphere. This example is defined when the
surfaces $\Sigma_1$ and $ \Sigma_2$ are spheres.


title: Cavity method for quantum spin glasses on the Bethe lattice

abstract:
  We propose a generalization of the cavity method to quantum spin glasses on
fixed connectivity lattices. Our work is motivated by the recent refinements of
the classical technique and its potential application to quantum computational
problems. We numerically solve for the phase structure of a connectivity $q=3$
transverse field Ising model on a Bethe lattice with $\pm J$ couplings, and
investigate the distribution of various classical and quantum observables.


title: Vector Meson production from NLL BFKL

abstract:
  The amplitude for the forward electroproduction of two light vector mesons
can be written completely within perturbative QCD in the Regge limit with
next-to-leading accuracy, thus providing the first example of a physical
application of the BFKL approach at the next-to-leading order. We study in the
case of equal photon virtualities the main systematic effects, by considering a
different representation of the amplitude and different optimization methods of
the perturbative series.


title:
$\bar{K}NN$ quasi-bound state and the $\bar{K}N$ interaction:
  coupled-channel Faddeev calculations of the $\bar{K}NN - \pi \Sigma N$ system

abstract:
  Coupled-channel three-body calculations of an $I=1/2$, $J^{\pi}=0^-$
$\bar{K}NN$ quasi-bound state in the $\bar{K}NN - \pi \Sigma N$ system were
performed and the dependence of the resulting three-body energy on the two-body
$\bar{K}N - \pi \Sigma$ interaction was investigated. Earlier results of
binding energy $B_{K^-pp} \sim 50 -70$ MeV and width $\Gamma_{K^-pp} \sim 100$
MeV are confirmed [N.V. Shevchenko {\it et al.}, Phys. Rev. Lett. {\bf 98},
082301 (2007)]. It is shown that a suitably constructed energy-independent
complex $\bar{K}N$ potential gives a considerably shallower and narrower
three-body quasi-bound state than the full coupled-channel calculation.
Comparison with other calculations is made.


title:
Improvements on removing non-optimal support points in D-optimum design
  algorithms

abstract:
  We improve the inequality used in Pronzato [2003. Removing non-optimal
support points in D-optimum design algorithms. Statist. Probab. Lett. 63,
223-228] to remove points from the design space during the search for a
$D$-optimum design. Let $\xi$ be any design on a compact space $\mathcal{X}
\subset \mathbb{R}^m$ with a nonsingular information matrix, and let
$m+\epsilon$ be the maximum of the variance function $d(\xi,\mathbf{x})$ over
all $\mathbf{x} \in \mathcal{X}$. We prove that any support point
$\mathbf{x}_{*}$ of a $D$-optimum design on $\mathcal{X}$ must satisfy the
inequality $d(\xi,\mathbf{x}_{*}) \geq
m(1+\epsilon/2-\sqrt{\epsilon(4+\epsilon-4/m)}/2)$. We show that this new lower
bound on $d(\xi,\mathbf{x}_{*})$ is, in a sense, the best possible, and how it
can be used to accelerate algorithms for $D$-optimum design.


title:
The distribution of free path lengths in the periodic Lorentz gas and
  related lattice point problems

abstract:
  The periodic Lorentz gas describes the dynamics of a point particle in a
periodic array of spherical scatterers, and is one of the fundamental models
for chaotic diffusion. In the present paper we investigate the Boltzmann-Grad
limit, where the radius of each scatterer tends to zero, and prove the
existence of a limiting distribution for the free path length of the periodic
Lorentz gas. We also discuss related problems, such as the statistical
distribution of directions of lattice points that are visible from a fixed
position.


title: Silver staining of proteins in polyacrylamide gels

abstract:
  Silver staining is used to detect proteins after electrophoretic separation
on polyacrylamide gels. It combines excellent sensitivity (in the low nanogram
range) with the use of very simple and cheap equipment and chemicals. It is
compatible with downstream processing, such as mass spectrometry analysis after
protein digestion. The sequential phases of silver staining are protein
fixation, then sensitization, then silver impregnation and finally image
development. Several variants of silver staining are described here, which can
be completed in a time range from 2 h to 1 d after the end of the
electrophoretic separation. Once completed, the stain is stable for several
weeks.


title: Egorov property in perturbed cat map

abstract:
  We study the time evolution of the quantum-classical correspondence (QCC) for
the well known model of quantised perturbed cat maps on the torus in the very
specific regime of semi-classically small perturbations. The quality of the QCC
is measured by the overlap of classical phase-space density and corresponding
Wigner function of the quantum system called quantum-classical fidelity (QCF).
In the analysed regime the QCF strongly deviates from the known general
behaviour in particular it decays faster then exponential. Here we study and
explain the observed behavior of the QCF and the apparent violation of the QCC
principle.


title:
Strong-Coupling Superconductivity of CeIrSi$_3$ with the
  Non-centrosymmetric Crystal Structure

abstract:
  We studied the pressure-induced superconductor CeIrSi$_3$ with the
non-centrosymmetric tetragonal structure under high pressure. The electrical
resistivity and ac heat capacity were measured in the same run for the same
sample. The critical pressure was determined to be $P_{\rm c}$ = 2.25 GPa,
where the antiferromagnetic state disappears. The heat capacity $C_{\rm ac}$
shows both antiferromagnetic and superconducting transitions at pressures close
to $P_{\rm c}$. On the other hand, the superconducting region is extended to
high pressures of up to about 3.5 GPa, with the maximum transition temperature
$T_{\rm sc}$ = 1.6 K around $2.5-2.7$ GPa. At 2.58 GPa, a large heat capacity
anomaly was observed at $T_{\rm sc}$ = 1.59 K. The jump of the heat capacity in
the form of ${\Delta}{C_{\rm ac}}/C_{\rm ac}(T_{\rm sc})$ is 5.7 $\pm$ 0.1.
This is the largest observed value among previously reported superconductors,
indicating the strong-coupling superconductivity. The electronic specific heat
coefficient at $T_{\rm sc}$ is, however, approximately unchanged as a function
of pressure, even at $P_{\rm c}$.


title: A criterion for entanglement in two two-level systems

abstract:
  We prove a necessary and sufficient condition for the occurrence of
entanglement in two two-level systems, simple enough to be of experimental
interest. Our results are illustrated in the context of a spin star system
analyzing the exact entanglement evolution of the central couple of spins.


title: Albert Einstein - a Pious Atheist

abstract:
  We consider Einstein's attitude with regard to religion both from
sociological and epistemological points of view. An attempt to put it into a
wider socio-historical perspective has been made, with the emphasis on his
ethnic and religious background. The great scientist was neither anatheist nor
a believer in the orthodox sense and the closest labels one might apply would
be pantheism/cosmism (ontological view) and agnosticism (epistemological view).
His ideas on the divine could be considered as a continuation of a line that
can be traced back to Philo of Alexandria, who himself followed the Greek
Stoics and Neoplatonists and especially Baruch Spinoza. Einstein's scientific
(or rational) and religious (or intuitive) thinking was deeply rooted in the
Hellenic culture.


title:
Dynamics of DNA-breathing: Weak noise analysis, finite time singularity,
  and mapping onto the quantum Coulomb problem

abstract:
  We study the dynamics of denaturation bubbles in double-stranded DNA on the
basis of the Poland-Scheraga model. We show that long time distributions for
the survival of DNA bubbles and the size autocorrelation function can be
derived from an asymptotic weak noise approach. In particular, below the
melting temperature the bubble closure corresponds to a noisy finite time
singularity. We demonstrate that the associated Fokker-Planck equation is
equivalent to a quantum Coulomb problem. Below the melting temperature the
bubble lifetime is associated with the continuum of scattering states of the
repulsive Coulomb potential; at the melting temperature the Coulomb potential
vanishes and the underlying first exit dynamics exhibits a long time power law
tail; above the melting temperature, corresponding to an attractive Coulomb
potential, the long time dynamics is controlled by the lowest bound state.
Correlations and finite size effects are discussed.


title: Thermal gradient-induced forces on geodetic reference masses for LISA

abstract:
  The low frequency sensitivity of space-borne gravitational wave observatories
will depend critically on the geodetic purity of the trajectories of orbiting
test masses. Fluctuations in the temperature difference across the enclosure
surrounding the free-falling test mass can produce noisy forces through several
processes, including the radiometric effect, radiation pressure, and
outgassing. We present here a detailed experimental investigation of thermal
gradient-induced forces for the LISA gravitational wave mission and the LISA
Pathfinder, employing high resolution torsion pendulum measurements of the
torque on a LISA-like test mass suspended inside a prototype of the LISA
gravitational reference sensor that will surround the test mass in orbit. The
measurement campaign, accompanied by numerical simulations of the radiometric
and radiation pressure effects, allows a more accurate and representative
characterization of thermal-gradient forces in the specific geometry and
environment relevant to LISA free-fall. The pressure dependence of the measured
torques allows clear identification of the radiometric effect, in quantitative
agreement with the model developed. In the limit of zero gas pressure, the
measurements are most likely dominated by outgassing, but at a low level that
does not threaten the LISA sensitivity goals.


title: Recursion between Mumford volumes of moduli spaces

abstract:
  We propose a new proof, as well as a generalization of Mirzakhani's recursion
for volumes of moduli spaces. We interpret those recursion relations in terms
of expectation values in Kontsevich's integral, i.e. we relate them to a Ribbon
graph decomposition of Riemann surfaces. We find a generalization of
Mirzakhani's recursions to measures containing all higher Mumford's kappa
classes, and not only kappa1 as in the Weil-Petersson case.


title: Muon multiplicity at high energy proton-nuclei collisions

abstract:
  Estimation of multiplicity of muons and pions production at high energy
proton-nuclei collisions is given. Both QED and QCD contributions are
considered for peripheral kinematics of muon pair and $\sigma$-meson
production, keeping in mind it's final conversion to muons. An attempt to
explain the excess of positive charged muons compared to negative one in cosmic
muon showers is given.
  We derive the dependence of cross-section of $n$ pairs as a function of $n$
at large n as $d^n(n!n^2)^{-1}$.


title: Tightness of voter model interfaces

abstract:
  Consider a long-range, one-dimensional voter model started with all zeroes on
the negative integers and all ones on the positive integers. If the process
obtained by identifying states that are translations of each other is
positively recurrent, then it is said that the voter model exhibits interface
tightness. In 1995, Cox and Durrett proved that one-dimensional voter models
exhibit interface tightness if their infection rates have a finite third
moment. Recently, Belhaouari, Mountford, and Valle have improved this by
showing that a finite second moment suffices. The present paper gives a new
short proof of this fact. We also prove interface tightness for a long range
swapping voter model, which has a mixture of long range voter model and
exclusion process dynamics.


title: Self-motile colloidal particles: from directed propulsion to random walk

abstract:
  The motion of an artificial micro-scale swimmer that uses a chemical reaction
catalyzed on its own surface to achieve autonomous propulsion is fully
characterized experimentally. It is shown that at short times, it has a
substantial component of directed motion, with a velocity that depends on the
concentration of fuel molecules. At longer times, the motion reverts to a
random walk with a substantially enhanced diffusion coefficient. Our results
suggest strategies for designing artificial chemotactic systems.


title: Supersymmetric heterotic string backgrounds

abstract:
  We present the main features of the solution of the gravitino and dilatino
Killing spinor equations derived in hep-th/0510176 and hep-th/0703143 which
have led to the classification of geometric types of all type I backgrounds. We
then apply these results to the supersymmetric backgrounds of the heterotic
string. In particular, we solve the gaugino Killing spinor equation together
with the other two Killing spinor equations of the theory. We also use our
results to classify all supersymmetry conditions of ten-dimensional gauge
theory.


title:
Genetic embedded matching approach to ground states in continuous-spin
  systems

abstract:
  Due to an extremely rugged structure of the free energy landscape, the
determination of spin-glass ground states is among the hardest known
optimization problems, found to be NP-hard in the most general case. Owing to
the specific structure of local (free) energy minima, general-purpose
optimization strategies perform relatively poorly on these problems, and a
number of specially tailored optimization techniques have been developed in
particular for the Ising spin glass and similar discrete systems. Here, an
efficient optimization heuristic for the much less discussed case of continuous
spins is introduced, based on the combination of an embedding of Ising spins
into the continuous rotators and an appropriate variant of a genetic algorithm.
Statistical techniques for insuring high reliability in finding (numerically)
exact ground states are discussed, and the method is benchmarked against the
simulated annealing approach.


title:
THERMINATOR simulations and PHENIX images of a heavy tail of particle
  emission in 200 GeV Au+Au collisions

abstract:
  Correlation between emitted particles from a thermalized medium carry
important information about the space-time extent and the dynamics of the
particle emitting source. Pion emission source functions S(r) have been
measured in PHENIX using an imaging technique, and it has been found that it
contains a heavy (power-law) tail. It leads us to the assumption that there is
a halo of secondary pions, surrounding the core system that undergoes the
hydrodynamical evolution. THERMINATOR, a Monte Carlo event generator designed
for studies in relativistic heavy-ion collisions is used to model and
investigate the influence of resonance decays on the tail of particle emission
source. It lacks the implementation of rescattering, which, as we have learnt
from previous Hadron Rescattering Code simulations, is a possible explanation
of the power-law tail. Our studies also have shown that none of the pion
sources alone are responsible for the tail: either the resonance decays or
rescattering or a combination of these effects is a possible cause of the heavy
tail.


title: Environment-Mediated Quantum State Transfer

abstract:
  We propose a scheme for quantum state transfer(QST) between two qubits which
is based on their individual interaction with a common boson environment. The
corresponding single mode spin-boson Hamiltonian is solved by mapping it onto a
wave propagation problem in a semi-infinite ladder and the fidelity is
obtained. High fidelity occurs when the qubits are equally coupled to the boson
while the fidelity becomes smaller for nonsymmetric couplings. The complete
phase diagram for such an arbitrary QST mediated by bosons is discussed.


title: Relaxation Enhancement by Time-Periodic Flows

abstract:
  We study enhancement of diffusive mixing by fast incompressible time-periodic
flows. The class of relaxation-enhancing flows that are especially efficient in
speeding up mixing has been introduced in [2]. The relaxation-enhancing
property of a flow has been shown to be intimately related to the properties of
the dynamical system it generates. In particular, time-independent flows $u$
such that the operator $u \cdot \nabla$ has sufficiently smooth eigenfunctions
are not relaxation-enhancing. Here we extend results of [2] to time-periodic
flows $u(x,t)$ and in particular show that there exist flows such that for each
fixed time the flow is Hamiltonian, but the resulting time-dependent flow is
relaxation-enhancing. Thus we confirm the physical intuition that time
dependence of a flow may aid mixing. We also provide an extension of our
results to the case of a nonlinear diffusion model. The proofs are based on a
general criterion for the decay of a semigroup generated by an operator of the
form $\Gamma+iAL(t)$ with a negative unbounded self-adjoint operator $\Gamma$,
a time-periodic self-adjoint operator-valued function $L(t)$, and a parameter
$A>>1$.


title: Optimal phase estimation in quantum networks

abstract:
  We address the problem of estimating the phase phi given N copies of the
phase rotation u(phi) within an array of quantum operations in finite
dimensions. We first consider the special case where the array consists of an
arbitrary input state followed by any arrangement of the N phase rotations, and
ending with a POVM. We optimise the POVM for a given input state and fixed
arrangement. Then we also optimise the input state for some specific cost
functions. In all cases, the optimal POVM is equivalent to a quantum Fourier
transform in an appropriate basis. Examples and applications are given.


title: Quantum wave equations in curved space-time from wave mechanics

abstract:
  Alternative versions of the Klein-Gordon and Dirac equations in a curved
spacetime are got by applying directly the classical-quantum correspondence.


title: Decay modes of $^{10}$C nuclei unbound state

abstract:
  Unbound states of $^{10}$C nuclei produced as quasi-projectiles in
$^{12}$C+$^{24}$Mg collisions at E/A = 53 and 95 MeV are studied with the Indra
detector array. Multi-particle correlation function analyses provide
experimental evidence of sequential de-excitation mechanisms through the
production of intermediate $^{9}$B, $^{6}$Be and $^{8}$Be unbound nuclei. The
relative contributions of different decay sequences to the total decay width of
the explored states is estimated semi-quantitatively. The obtained results show
that heavy-ion collisions can be used as a tool to access spectroscopic
information about exotic nuclei.


title: Labyrinthine pathways towards supercycle attractors in unimodal maps

abstract:
  We uncover previously unknown properties of the family of periodic
superstable cycles in unimodal maps characterized each by a Lyapunov exponent
that diverges to minus infinity. Amongst the main novel properties are the
following: i) The basins of attraction for the phases of the cycles develop
fractal boundaries of increasing complexity as the period-doubling structure
advances towards the transition to chaos. ii) The fractal boundaries, formed by
the preimages of the repellor, display hierarchical structures organized
according to exponential clusterings that manifest in the dynamics as
sensitivity to the final state and transient chaos. iii) There is a functional
composition renormalization group (RG) fixed-point map associated to the family
of supercycles. iv) This map is given in closed form by the same kind of
$q$-exponential function found for both the pitchfork and tangent bifurcation
attractors. v) There is a final stage ultra-fast dynamics towards the attractor
with a sensitivity to initial conditions that decreases as an exponential of an
exponential of time.


title:
Population III star formation in a Lambda CDM universe, II: Effects of a
  photodissociating background

abstract:
  We examine aspects of primordial star formation in the presence of a
molecular hydrogen-dissociating ultraviolet background. We compare a set of AMR
hydrodynamic cosmological simulations using a single cosmological realization
but with a range of ultraviolet background strengths in the Lyman-Werner band.
This allows us to study the effects of Lyman-Werner radiation on suppressing H2
cooling at low densities as well as the high-density evolution of the
collapsing core in a self-consistent cosmological framework. We find that the
addition of a photodissociating background results in a delay of the collapse
of high density gas at the center of the most massive halo in the simulation
and, as a result, an increase in the virial mass of this halo at the onset of
baryon collapse. We find that, contrary to previous results, Population III
star formation is not suppressed for J$_{21} \geq 0.1$, but occurs even with
backgrounds as high as J$_{21} = 1$. We find that H2 cooling leads to collapse
despite the depressed core molecular hydrogen fractions due to the elevated H2
cooling rates at $T=2-5 \times 10^3$ K. We observe a relationship between the
strength of the photodissociating background and the rate of accretion onto the
evolving protostellar cloud core, with higher LW background fluxes resulting in
higher accretion rates. Finally, we find that the collapsing halo cores in our
simulations do not fragment at densities below $n \sim 10^{10}$ cm$^{-3}$
regardless of the strength of the LW background, suggesting that Population III
stars forming in halos with T$_{vir} \sim 10^4$ K may still form in isolation.


title: Some Two Color, Four Variable Rado Numbers

abstract:
  There exists a minimum integer $N$ such that any 2-coloring of
$\{1,2,...,N\}$ admits a monochromatic solution to $x+y+kz =\ell w$ for $k,\ell
\in \mathbb{Z}^+$, where $N$ depends on $k$ and $\ell$. We determine $N$ when
$\ell-k \in \{0,1,2,3,4,5\}$, for all $k,\ell$ for which
${1/2}((\ell-k)^2-2)(\ell-k+1)\leq k \leq \ell-4$, as well as for arbitrary $k$
when $\ell=2$.


title:
Fermi surface pockets in ortho-II YBa$_2$Cu$_3$O$_{6.5}$: the origin of
  quantum oscillations?

abstract:
  In this paper we explore whether the quantum oscillation signals recently
observed in ortho-II YBa$_2$Cu$_3$O$_{6.5}$ may be explained by conventional
density functional band-structure theory. Our calculations show that the Fermi
surface of YBa$_2$Cu$_3$O$_{6.5}$ is extremely sensitive to small shifts in the
relative positions of the bands. With rigid band shifts of around 30 meV small
tubular pockets of Fermi surface develop around the Y point in the Brillouin
zone. The cross-sectional areas and band masses of the quantum oscillatory
orbits on these pockets are close to those observed. The difference between the
bandstructure of YBa$_2$Cu$_3$O$_{6.5}$ and YBa$_2$Cu$_4$O$_{8}$ are discussed.


title: Fossil AGN jets as ultra high energy particle accelerators

abstract:
  Remnants of AGN jets and their surrounding cocoons leave colossal
magnetohydrodynamic (MHD) fossil structures storing total energies ~10^{60}
erg. The original active galacic nucleus (AGN) may be dead but the fossil will
retain its stable configuration resembling the reversed-field pinch (RFP)
encountered in laboratory MHD experiments.
  In an RFP the longitudinal magnetic field changes direction at a critical
distance from the axis, leading to magnetic re-connection there, and to slow
decay of the large-scale RFP field. We show that this field decay induces
large-scale electric fields which can accelerate cosmic rays with an E^{-2}
power-law up to ultra-high energies with a cut-off depending on the fossil
parameters. The cut-off is expected to be rigidity dependent, implying the
observed composition would change from light to heavy close to the cut-off if
one or two nearby AGN fossils dominate. Given that several percent of the
universe's volume may house such slowly decaying structures, these fossils may
even re-energize ultra-high energy cosmic rays from distant/old sources,
offsetting the ``GZK-losses'' due to interactions with photons of the cosmic
microwave background radiation and giving evidence of otherwise undetectable
fossils. In this case the composition would remain light to the highest
energies if distant sources or fossils dominated, but otherwise would be mixed.
It is hoped the new generation of cosmic ray experiments such as the Pierre
Auger Observatory and ultra-high energy neutrino telescopes such as ANITA and
lunar Cherenkov experiments will clarify this.


title: Bounds on Van der Waerden Numbers and Some Related Functions

abstract:
  For positive integers $s$ and $k_1, k_2, ..., k_s$, let $w(k_1,k_2,...,k_s)$
be the minimum integer $n$ such that any $s$-coloring $\{1,2,...,n\} \to
\{1,2,...,s\}$ admits a $k_i$-term arithmetic progression of color $i$ for some
$i$, $1 \leq i \leq s$. In the case when $k_1=k_2=...=k_s=k$ we simply write
$w(k;s)$.
  That such a minimum integer exists follows from van der Waerden's theorem on
arithmetic progressions.
  In the present paper we give a lower bound for $w(k,m)$ for each fixed $m$.
We include a table with values of $w(k,3)$ which match this lower bound closely
for $5 \leq k \leq 16$. We also give an upper bound for $w(k,4)$, an upper
bound for $w(4;s)$, and a lower bound for $w(k;s)$ for an arbitrary fixed $k$.
We discuss a number of other functions that are closely related to the van der
Waerden function.


title: A presentation for Hilden's subgroup of the braid group

abstract:
  Consider the unit ball, B = D x [0,1], containing n unknotted arcs a_1, ...
a_n such that the boundary of each a_i lies in D x {0}. We give a finite
presentation for the mapping class group of B fixing the arcs {a_1, ..., a_n}
setwise and fixing D x {1} pointwise. This presentation is calculated using the
action of this group on a simply-connected complex.


title: Dynamics towards the Feigenbaum attractor

abstract:
  We expose at a previously unknown level of detail the features of the
dynamics of trajectories that either evolve towards the Feigenbaum attractor or
are captured by its matching repellor. Amongst these features are the
following: i) The set of preimages of the attractor and of the repellor are
embedded (dense) into each other. ii) The preimage layout is obtained as the
limiting form of the rank structure of the fractal boundaries between attractor
and repellor positions for the family of supercycle attractors. iii) The joint
set of preimages for each case form an infinite number of families of
well-defined phase-space gaps in the attractor or in the repellor. iv) The gaps
in each of these families can be ordered with decreasing width in accord to
power laws and are seen to appear sequentially in the dynamics generated by
uniform distributions of initial conditions. v) The power law with log-periodic
modulation associated to the rate of approach of trajectories towards the
attractor (and to the repellor) is explained in terms of the progression of gap
formation. vi) The relationship between the law of rate of convergence to the
attractor and the inexhaustible hierarchy feature of the preimage structure is
elucidated.


title:
Tuning Kinetic Magnetism of Strongly Correlated Electrons via Staggered
  Flux

abstract:
  We explore the kinetic magnetism of the infinite-$U$ repulsive Hubbard models
at low hole densities on various lattices with nearest-neighbor hopping
integrals modulated by a staggered magnetic flux $\pm\phi$. Tuning $\phi$ from
0 to $\pi$ makes the ground state (GS) change from a Nagaoka-type ferromagnetic
state to a Haerter-Shastry-type antiferromagnetic state at a critical $\phi_c$,
with both states being of kinetic origin. Intra-plaquette spin correlation, as
well as the GS energy, signals such a quantum criticality. This tunable kinetic
magnetism is generic, and appears in chains, ladders and two-dimensional
lattices with squares or triangles as elementary constituents.


title:
Steps toward a classifier for the Virtual Observatory. I. Classifying
  the SDSS photometric archive

abstract:
  Modern photometric multiband digital surveys produce large amounts of data
that, in order to be effectively exploited, need automatic tools capable to
extract from photometric data an objective classification. We present here a
new method for classifying objects in large multi-parametric photometric data
bases, consisting of a combination of a clustering algorithm and a cluster
agglomeration tool. The generalization capabilities and the potentialities of
this approach are tested against the complexity of the Sloan Digital Sky Survey
archive, for which an example of application is reported.


title: A simple model of Coulomb disorder and screening in graphene

abstract:
  We suggest a simple model of disorder in graphene assuming that there are
randomly distributed positive and negative centers with equal concentration
$N/2$ in the bulk of silicon oxide substrate. We show that at zero gate voltage
such disorder creates two-dimensional concentration $n_0 \sim N^{2/3}$ of
electrons and holes in graphene. Electrons and holes reside in alternating in
space puddles of the size $R_0 \sim N^{-1/3}$. A typical puddle has only one or
two carriers in agreement with recent scanning single electron transistor
experiment.


title:
Be stars and binaries in the field of the SMC open cluster NGC330 with
  VLT-FLAMES

abstract:
  Observations of hot stars belonging to the young cluster SMC-NGC330 and its
surrounding region were obtained with the VLT-GIRAFFE facilities in MEDUSA
mode. We investigated the B and Be star properties and proportions in this
environment of low metallicity. We also searched for rapid variability in Be
stars using photometric databases. With spectroscopic measurements we
characterized the emission and properties of Be stars. By cross-correlation
with photometric databases such as MACHO and OGLE, we searched for binaries in
our sample of hot stars, as well as for short-term variability in Be stars. We
report on the global characteristics of the Be star sample (131 objects). We
find that the proportion of early Be stars with a large equivalent width of the
Halpha emission line is higher in the SMC than in the LMC and MW. We find a
slight increase in the proportion of Be stars compared to B-type stars with
decreasing metallicity. We also discovered spectroscopic and photometric
binaries, and for the latter we give their orbital period. We identify 13 Be
stars with short-term variability. We determine their period(s) and find that 9
Be stars are multiperiodic.


title: Growing neutrinos and cosmological selection

abstract:
  The time evolution of a cosmological scalar field can be stopped by an
increasing mass of the neutrinos. This leads to a transition from a
cosmological scaling solution with dynamical dark energy at early time to a
cosmological constant dominated universe at late time. The trigger for the
transition is set at the time when the neutrinos become non-relativistic. The
characteristic mass scale for dark energy is thus related to the neutrino mass,
the only known particle physics scale in its vicinity. This explains the ``why
now problem'' for dark energy. We present a particle physics realization of
this ``growing matter'' scenario. It is based on the very slowly varying mass
of a superheavy scalar triplet field whose expectation value dominates the
light neutrino masses.


title: Semi-analytical approach to magnetized temperature autocorrelations

abstract:
  The cosmic microwave background (CMB) temperature autocorrelations, induced
by a magnetized adiabatic mode of curvature inhomogeneities, are computed with
semi-analytical methods. As suggested by the latest CMB data, a nearly
scale-invariant spectrum for the adiabatic mode is consistently assumed. In
this situation, the effects of a fully inhomogeneous magnetic field are
scrutinized and constrained with particular attention to harmonics which are
relevant for the region of Doppler oscillations. Depending on the parameters of
the stochastic magnetic field a hump may replace the second peak of the angular
power spectrum. Detectable effects on the Doppler region are then expected only
if the magnetic power spectra have quasi-flat slopes and typical amplitude
(smoothed over a comoving scale of Mpc size and redshifted to the epoch of
gravitational collapse of the protogalaxy) exceeding 0.1 nG. If the magnetic
energy spectra are bluer (i.e. steeper in frequency) the allowed value of the
smoothed amplitude becomes, comparatively, larger (in the range of 20 nG). The
implications of this investigation for the origin of large-scale magnetic
fields in the Universe are discussed. Connections with forthcoming experimental
observations of CMB temperature fluctuations are also suggested and partially
explored.


title: Observation of B^0 \to D^{*-} \tau^+ \nu_{\tau} decay at Belle

abstract:
  We report an observation of the decay $B^0\to D^{*-} \tau^+ \nu_{\tau}$ in a
data sample containing $535\times10^6$ $B\bar{B}$ pairs collected with the
Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We find a
signal with a significance of 5.2 standard deviations and measure the branching
fraction $\mathcal{B}(B^0\to D^{*-} \tau ^+ \nu_{\tau})=(2.02 ^{+0.40}_{-0.37}
(stat) \pm 0.37 (syst)) % $. This is the first observation of an exclusive $B$
decay with a $b \to c \tau \nu_{\tau}$ transition.


title:
Investigating the extended geometric scaling region at LHC with
  polarized and unpolarized final states

abstract:
  We present predictions for charged hadron production and Lambda polarization
in p-p and p-Pb collisions at the LHC using the saturation inspired DHJ model
for the dipole cross section in the extended geometric scaling region.


title: The Einstein static universe in Loop Quantum Cosmology

abstract:
  Loop Quantum Cosmology strongly modifies the high-energy dynamics of
Friedman-Robertson-Walker models and removes the big-bang singularity. We
investigate how LQC corrections affect the stability properties of the Einstein
static universe. In General Relativity, the Einstein static model with positive
cosmological constant Lambda is unstable to homogeneous perturbations. We show
that LQC modifications can lead to a centre of stability for a large enough
positive value of Lambda.


title: The minority game: An economics perspective

abstract:
  This paper gives a critical account of the minority game literature. The
minority game is a simple congestion game: players need to choose between two
options, and those who have selected the option chosen by the minority win. The
learning model proposed in this literature seems to differ markedly from the
learning models commonly used in economics. We relate the learning model from
the minority game literature to standard game-theoretic learning models, and
show that in fact it shares many features with these models. However, the
predictions of the learning model differ considerably from the predictions of
most other learning models. We discuss the main predictions of the learning
model proposed in the minority game literature, and compare these to
experimental findings on congestion games.


title: Relaxation dynamics of a quantum Brownian particle in an ideal gas

abstract:
  We show how the quantum analog of the Fokker-Planck equation for describing
Brownian motion can be obtained as the diffusive limit of the quantum linear
Boltzmann equation. The latter describes the quantum dynamics of a tracer
particle in a dilute, ideal gas by means of a translation-covariant master
equation. We discuss the type of approximations required to obtain the
generalized form of the Caldeira-Leggett master equation, along with their
physical justification. Microscopic expressions for the diffusion and
relaxation coefficients are obtained by analyzing the limiting form of the
equation in both the Schroedinger and the Heisenberg picture.


title: Pairing of 1D Bose-Fermi mixtures with unequal masses

abstract:
  We have considered one-dimensional Bose-Fermi mixture with equal densities
and unequal masses using numerical density matrix renormalization group (DMRG).
For the mass ratio of K-Rb mixture and attraction between bosons and fermions,
we determined the phase diagram. For weak boson-boson interactions, there is a
direct transition between two-component Luttinger liquid and collapsed phases
as the boson-fermion attraction is increased. For strong enough boson-boson
interactions, we find an intermediate "paired" phase, which is a
single-component Luttinger liquid of composite particles. We investigated
correlation functions of such a "paired" phase, studied the stability of
"paired" phase to density imbalance, and discussed various experimental
techniques which can be used to detect it.


title: Discovery of Very High Energy gamma-rays from 1ES 1011+496 at z=0.212

abstract:
  We report on the discovery of Very High Energy (VHE) gamma-ray emission from
the BL Lacertae object 1ES1011+496. The observation was triggered by an optical
outburst in March 2007 and the source was observed with the MAGIC telescope
from March to May 2007. Observing for 18.7 hr we find an excess of 6.2 sigma
with an integrated flux above 200 GeV of (1.58$\pm0.32) 10^{-11}$ photons
cm$^{-2}$ s$^{-1}$. The VHE gamma-ray flux is >40% higher than in March-April
2006 (reported elsewhere), indicating that the VHE emission state may be
related to the optical emission state. We have also determined the redshift of
1ES1011+496 based on an optical spectrum that reveals the absorption lines of
the host galaxy. The redshift of z=0.212 makes 1ES1011+496 the most distant
source observed to emit VHE gamma-rays up to date.


title:
On the moment limit of quantum observables, with an application to the
  balanced homodyne detection

abstract:
  We consider the moment operators of the observable (i.e. a semispectral
measure or POM) associated with the balanced homodyne detection statistics,
with paying attention to the correct domains of these unbounded operators. We
show that the high amplitude limit, when performed on the moment operators,
actually determines uniquely the entire statistics of a rotated quadrature
amplitude of the signal field, thereby verifying the usual assumption that the
homodyne detection achieves a measurement of that observable. We also consider,
in a general setting, the possibility of constructing a measurement of a single
quantum observable from a sequence of observables by taking the limit on the
level of moment operators of these observables. In this context, we show that
under some natural conditions (each of which is satisfied by the homodyne
detector example), the existence of the moment limits ensures that the
underlying probability measures converge weakly to the probability measure of
the limiting observable. The moment approach naturally requires that the
observables be determined by their moment operator sequences (which does not
automatically happen), and it turns out, in particular, that this is the case
for the balanced homodyne detector.


title:
Gravitational waves from inspiralling compact binaries: hexagonal
  template placement and its efficiency in detecting physical signals

abstract:
  Matched filtering is used to search for gravitational waves emitted by
inspiralling compact binaries in data from the ground-based interferometers.
One of the key aspects of the detection process is the design of a template
bank that covers the astrophysically pertinent parameter space. In an earlier
paper, we described a template bank that is based on a square lattice. Although
robust, we showed that the square placement is over-efficient, with the
implication that it is computationally more demanding than required. In this
paper, we present a template bank based on an hexagonal lattice, which size is
reduced by 40% with respect to the proposed square placement. We describe the
practical aspects of the hexagonal template bank implementation, its size, and
computational cost. We have also performed exhaustive simulations to
characterize its efficiency and safeness. We show that the bank is adequate to
search for a wide variety of binary systems (primordial black holes, neutron
stars and stellar mass black holes) and in data from both current detectors
(initial LIGO, Virgo and GEO600) as well as future detectors (advanced LIGO and
EGO). Remarkably, although our template bank placement uses a metric arising
from a particular template family, namely stationary phase approximation, we
show that it can be used successfully with other template families (e.g., Pade
resummation and effective one-body approximation). This quality of being
effective for different template families makes the proposed bank suitable for
a search that would use several of them in parallel (e.g., in a binary black
hole search). The hexagonal template bank described in this paper is currently
used to search for non-spinning inspiralling compact binaries in data from the
Laser Interferometer Gravitational-Wave Observatory (LIGO).


title: Non-Markovian quantum jumps

abstract:
  Open quantum systems that interact with structured reservoirs exhibit
non-Markovian dynamics. We present a quantum jump method for treating the
dynamics of such systems. This approach is a generalization of the standard
Monte Carlo Wave Function (MCWF) method for Markovian dynamics. The MCWF method
identifies decay rates with jump probabilities and fails for non-Markovian
systems where the time-dependent rates become temporarily negative. Our
non-Markovian quantum jump (NMQJ) approach circumvents this problem and
provides an efficient unravelling of the ensemble dynamics.


title: AGN Observations in the GeV/TeV Energy Range with the MAGIC Telescope

abstract:
  MAGIC currently is the largest imaging atmospheric Cerenkov telescope
world-wide. Since 2004, gamma-ray emission from several active galactic nuclei
in the GeV/TeV energy range has been detected, some of which were newly
discovered as very-high energy gamma-ray sources. The gamma-rays are assumed to
originate from particle acceleration processes in the AGN jets. We give an
overview of the AGN observed and detected by MAGIC, discuss spectral and
temporal properties of these and show physics implications of some selected
observations.


title: 2-State 3-Symbol Universal Turing Machines Do Not Exist

abstract:
  In this brief note, we give a simple information-theoretic proof that 2-state
3-symbol universal Turing machines cannot possibly exist, unless one loosens
the definition of "universal".


title:
Free $n$-distributions: holonomy, sub-Riemannian structures, Fefferman
  constructions and dual distributions

abstract:
  This paper analyses the parabolic geometries generated by a free
$n$-distribution in the tangent space of a manifold. It shows that certain
holonomy reductions of the associated normal Tractor connections, imply
preferred connections with special properties, along with Riemannian or
sub-Riemannian structures on the manifold. It constructs examples of these
holonomy reductions in the simplest cases. The main results, however, lie in
the free 3-distributions. In these cases, there are normal Fefferman
constructions over CR and Lagrangian contact structures corresponding to
holonomy reductions to SO(4,2) and SO(3,3), respectively. There is also a
fascinating construction of a `dual' distribution when the holonomy reduces to
$G_2'$.


title:
A First Synoptic Blazar Study Comprising Thirteen Blazars Visible in
  E>100 GeV Gamma-Rays

abstract:
  Since 2002, the number of detected blazars at E_\gamma > 100 GeV has more
than doubled. I study all currently known BL Lac-type objects with published
energy spectra. Their intrinsic energy spectra are reconstructed by removing
extragalactic background light attenuation effects. The emission properties are
then compared and correlated among each other, with X-ray data, and with the
individual black hole masses. In addition, I consider temporal properties of
the very high energy gamma-ray flux. Key findings concern the flux--black hole
mass and variability scale--black hole mass connections and the correlation of
the spectral slope and the luminosity. As a specific application, the study
allows to constrain the still undetermined redshift of the blazar PG 1553+113.


title: Thermal Dileptons at LHC

abstract:
  We predict dilepton invariant-mass spectra for central 5.5 ATeV Pb-Pb
collisions at LHC. Hadronic emission in the low-mass region is calculated using
in-medium spectral functions of light vector mesons within hadronic many-body
theory. In the intermediate-mass region thermal radiation from the Quark-Gluon
Plasma, evaluated perturbatively with hard-thermal loop corrections, takes
over. An important source over the entire mass range are decays of correlated
open-charm hadrons, rendering the nuclear modification of charm and bottom
spectra a critical ingredient.


title:
Automatic Active-Region Identification and Azimuth Disambiguation of the
  SOLIS/VSM Full-Disk Vector Magnetograms

abstract:
  The Vector Spectromagnetograph (VSM) of the NSO's Synoptic Optical Long-Term
Investigations of the Sun (SOLIS) facility is now operational and obtains the
first-ever vector magnetic field measurements of the entire visible solar
hemisphere. To fully exploit the unprecedented SOLIS/VSM data, however, one
must first address two critical problems: first, the study of solar active
regions requires an automatic, physically intuitive, technique for
active-region identification in the solar disk. Second, use of active-region
vector magnetograms requires removal of the azimuthal $180^o$-ambiguity in the
orientation of the transverse magnetic field component. Here we report on an
effort to address both problems simultaneously and efficiently. To identify
solar active regions we apply an algorithm designed to locate complex,
flux-balanced, magnetic structures with a dominant E-W orientation on the disk.
Each of the disk portions corresponding to active regions is thereafter
extracted and subjected to the Nonpotential Magnetic Field Calculation (NPFC)
method that provides a physically-intuitive solution of the 180-degree
ambiguity. Both algorithms have been integrated into the VSM data pipeline and
operate in real time, without human intervention. We conclude that this
combined approach can contribute meaningfully to our emerging capability for
full-disk vector magnetography as pioneered by SOLIS today and will be carried
out by ground-based and space-borne magnetographs in the future.


title: Random Fiber Laser

abstract:
  We investigate the effects of two dimensional confinement on the lasing
properties of a classical random laser system operating in the incoherent
feedback (diffusive) regime. A suspension of 250nm rutile (TiO2) particles in a
Rhodamine 6G solution was inserted into the hollow core of a photonic crystal
fiber (PCF) generating the first random fiber laser and a novel
quasi-one-dimensional RL geometry. Comparison with similar systems in bulk
format shows that the random fiber laser presents an efficiency that is at
least two orders of magnitude higher.


title: An optimization problem with volume constrain in Orlicz spaces

abstract:
  We consider the optimization problem of minimizing $\int_{\Omega}G(|\nabla
u|) dx$ in the class of functions $W^{1,G}(\Omega)$, with a constrain on the
volume of $\{u>0\}$. The conditions on the function $G$ allow for a different
behavior at
  0 and at $\infty$. We consider a penalization problem, and we prove that for
small values of the penalization parameter, the constrained volume is attained.
In this way we prove that every solution $u$ is locally Lipschitz continuous
and that the free boundary, $\partial\{u>0\}\cap \Omega$, is smooth.


title:
Pure motives, mixed motives and extensions of motives associated to
  singular surfaces

abstract:
  We first recall the construction of the Chow motive modelling intersection
cohomology of a proper surface and study its fundamental properties. Using
Voevodsky's category of effective geometrical motives, we then study the motive
of the exceptional divisor in a non-singular blow-up. If all geometric
irreducible components of the divisor are of genus zero, then Voevodsky's
formalism allows us to construct certain one-extensions of Chow motives, as
canonical sub-quotients of the motive with compact support of the smooth part
of the surface. Specializing to Hilbert--Blumenthal surfaces, we recover a
motivic interpretation of a recent construction of A. Caspar.


title:
Search for Anomalous Production of Multilepton Events in p-pbar
  Collisions at sqrt(s) = 1.96 TeV

abstract:
  We report a search for the anomalous production of events with multiple
charged leptons in p-pbar collisions at sqrt{s} = 1.96 TeV using a data sample
corresponding to an integrated luminosity of 346 pb^{-1} collected by the CDF
II detector at the Fermilab Tevatron. The search is divided into three-lepton
and four-or-more-lepton data samples. We observe six events in the three-lepton
sample and zero events in the >=4-lepton sample. Both numbers of events are
consistent with standard model background expectations. Within the framework of
an R-parity violating supergravity model, the results are interpreted as mass
limits on the lightest neutralino and chargino particles. For one particular
choice of model parameters, the limits are M_neutralino > 110 GeV/c^{2} and
M_chargino > 203 GeV/c^{2} at 95% confidence level; the variation of these mass
limits with model parameters is presented.


title: Cheeger constants of surfaces and isoperimetric inequalities

abstract:
  We show that the Cheeger constant of compact surfaces is bounded by a
function of the area. We apply this to isoperimetric profiles of bounded genus
non-compact surfaces, to show that if their isoperimetric profile grows faster
than $\sqrt t$, then it grows at least as fast as a linear function. This
generalizes a result of Gromov for simply connected surfaces.
  We study the isoperimetric problem in dimension 3. We show that if the
filling volume function in dimension 2 is Euclidean, while in dimension 3 is
sub-Euclidean and there is a $g$ such that minimizers in dimension 3 have genus
at most $g$, then the filling function in dimension 3 is `almost' linear.


title:
Quadratic optimal functional quantization of stochastic processes and
  numerical applications

abstract:
  In this paper, we present an overview of the recent developments of
functional quantization of stochastic processes, with an emphasis on the
quadratic case. Functional quantization is a way to approximate a process,
viewed as a Hilbert-valued random variable, using a nearest neighbour
projection on a finite codebook. A special emphasis is made on the
computational aspects and the numerical applications, in particular the pricing
of some path-dependent European options.


title: Turbulence models generator

abstract:
  In this paper we explore a possibility that all transport turbulent models
are contained in a coarse-grained kinetic equation. Building on a recent work
by H.Chen et al (2004), we account for fluctuations of a single -point
probability density in turbulence, by introducing a``two-level'' (${\bf
c,v}$)-phase-space, separating microscopic (${\bf c'\equiv c_{micro}= c-v}$)
and hydrodynamic (${\bf v'=v-V}$) modes. Unlike traditional kinetic theories,
with hydrodynamic approximations derived in terms of small deviations from
thermodynamic equilibrium, the theory developed in this work, is based on a
far- from -equilibrium isotropic and homogeneous turbulence as an unperturbed
state. The expansion in dimensionless rate of strain leads to a new class of
turbulent models, including the well-known ${\cal K}-{\cal E}$, Reynolds stress
and all possible nonlinear models. The role of interaction of the fluxes in
physical space with the energy flux across the scales, not present in standard
modeling, is demonstrated on example of turbulent channel flow. To close the
system, neither equation for turbulent kinetic energy nor information on
pressure-velocity correlations, contained in the derived coarse-grained kinetic
equation, are needed.


title: What is the Mathematical Structure of Quantum Spacetime?

abstract:
  We survey indications from different branches of Physics that the fine scale
structure of spacetime is not adequately described by a manifold. Based on the
hints we accumulate, we propose a new structure, which we call a quantum topos.
In the process of constructing a quantum topos for quantum gravity, we propose
a new, operational approach to the problem of the obervables in quantum
gravity, which leads to a new mathematical point of view on the state sum
models.


title:
Systematic search for VHE gamma-ray emission from X-ray bright
  high-frequency BL Lac objects

abstract:
  All but three (M87, BL Lac and 3C 279) extragalactic sources detected so far
at very high energy (VHE) gamma-rays belong to the class of high-frequency
peaked BL Lac (HBL) objects. This suggested to us a systematic scan of
candidate sources with the MAGIC telescope, based on the compilation of X-ray
blazars by Donato et al. (2001). The observations took place from December 2004
to March 2006 and cover sources on the northern sky visible under small zenith
distances zd < 30 degrees at culmination. The sensitivity of the search was
planned for detecting X-ray bright F(1 keV) > 2 uJy) sources emitting at least
the same energy flux at 200 GeV as at 1 keV. In order to avoid strong gamma-ray
attenuation close to the energy threshold, the redshift of the sources was
constrained to values z<0.3. Of the fourteen sources observed, 1ES 1218+304 and
1ES 2344+514 have been detected in addition to the known bright TeV blazars Mrk
421 and Mrk 501. A marginal excess of 3.5 sigma from the position of 1ES
1011+496 was observed and has been confirmed as a source of VHE gamma-rays by a
second MAGIC observation triggered by a high optical state (Albert et al.
2007). For the remaining sources, we present here the 99% confidence level
upper limits on the integral flux above ~200 GeV. We characterize the sample of
HBLs (including all HBLs detected at VHE so far) by looking for correlations
between their multi-frequency spectral indices determined from simultaneous
optical, archival X-ray, and radio luminosities, finding that the VHE emitting
HBLs do not seem to constitute a unique subclass. The absorption corrected
gamma-ray luminosities at 200 GeV of the HBLs are generally not higher than
their X-ray luminosities at 1 keV.


title:
Synchronization in networks of networks: the onset of coherent
  collective behavior in systems of interacting populations of heterogeneous
  oscillators

abstract:
  The onset of synchronization in networks of networks is investigated.
Specifically, we consider networks of interacting phase oscillators in which
the set of oscillators is composed of several distinct populations. The
oscillators in a given population are heterogeneous in that their natural
frequencies are drawn from a given distribution, and each population has its
own such distribution. The coupling among the oscillators is global, however,
we permit the coupling strengths between the members of different populations
to be separately specified. We determine the critical condition for the onset
of coherent collective behavior, and develop the illustrative case in which the
oscillator frequencies are drawn from a set of (possibly different)
Cauchy-Lorentz distributions. One motivation is drawn from neurobiology, in
which the collective dynamics of several interacting populations of oscillators
(such as excitatory and inhibitory neurons and glia) are of interest.


title:
Anomalous metallic state of Cu$_{0.07}$TiSe$_2$: an optical spectroscopy
  study

abstract:
  We report an optical spectroscopy study on the newly discovered
superconductor Cu$_{0.07}$TiSe$_2$. Consistent with the development from a
semimetal or semiconductor with a very small indirect energy gap upon doping
TiSe$_2$, it is found that the compound has a low carrier density. Most
remarkably, the study reveals a substantial shift of the "screened" plasma edge
in reflectance towards high energy with decreasing temperature. This
phenomenon, rarely seen in metals, indicates either a sizeable increase of the
conducting carrier concentration or/and a decrease of the effective mass of
carriers with reducing temperature. We attribute the shift primarily to the
later effect.


title: Heavy-Quark Kinetics in the QGP at LHC

abstract:
  We present predictions for the nuclear modification factor and elliptic flow
of D and B mesons, as well as of their decay electrons, in semicentral Pb-Pb
collisions at the LHC. Heavy quarks are propagated in a Quark-Gluon Plasma
using a relativistic Langevin simulation with drag and diffusion coefficients
from elastic interactions with light anti-/quarks and gluons, including
non-perturbative resonance scattering. Hadronization at T_c is performed within
a combined coalescence-fragmentation scheme.


title:
Dissipation Scale Fluctuations and Chemical Reaction Rates in Turbulent
  Flows

abstract:
  Small separation between reactants, not exceeding $10^{-8}-10^{-7}cm$, is the
necessary condition for various chemical reactions. It is shown that random
advection and stretching by turbulence leads to formation of scalar-enriched
sheets of {\it strongly fluctuating thickness} $\eta_{c}$. The molecular-level
mixing is achieved by diffusion across these sheets (interfaces) separating the
reactants. Since diffusion time scale is $\tau_{d}\propto \eta_{c}^{2}$, the
knowledge of probability density $Q(\eta_{c},Re)$ is crucial for evaluation of
chemical reaction rates. In this paper we derive the probability density
$Q(\eta_{c},Re,Sc)$ and predict a transition in the reaction rate behavior from
${\cal R}\propto \sqrt{Re}$ ($Re\leq 10^{4}$) to the high-Re asymptotics ${\cal
R}\propto Re^{0}$. The theory leads to an approximate universality of
transitional Reynolds number $Re_{tr}\approx 10^{4}$. It is also shown that if
chemical reaction involves short-lived reactants, very strong anomalous
fluctuations of the length-scale $\eta_{c}$ may lead to non-negligibly small
reaction rates.


title: The Popescu-Gabriel theorem for triangulated categories

abstract:
  The Popescu-Gabriel theorem states that each Grothendieck abelian category is
a localization of a module category. In this paper, we prove an analogue where
Grothendieck abelian categories are replaced by triangulated categories which
are well generated (in the sense of Neeman) and algebraic (in the sense of
Keller). The role of module categories is played by derived categories of small
differential graded categories. An analogous result for topological
triangulated categories has recently been obtained by A. Heider.


title: A note on the stability for Kawahara-KdV type equations

abstract:
  In this paper we establish the nonlinear stability of solitary traveling-wave
solutions for the Kawahara-KdV equation $$u_t+uu_x+u_{xxx}-\gamma_1
u_{xxxxx}=0,$$ and the modified Kawahara-KdV equation
$$u_t+3u^2u_x+u_{xxx}-\gamma_2 u_{xxxxx}=0,$$ where $\gamma_i\in\mathbb{R}$ is
a positive number when $i=1,2$. The main approach used to determine the
stability of solitary traveling-waves will be the theory developed by Albert


title: Counterterms in Dimensionally Continued AdS Gravity

abstract:
  We revise two regularization mechanisms for Lovelock gravity with AdS
asymptotics. The first one corresponds to the Dirichlet counterterm method,
where local functionals of the boundary metric are added to the bulk action on
top of a Gibbons-Hawking-Myers term that defines the Dirichlet problem in
gravity. The generalized Gibbons-Hawking term can be found in any Lovelock
theory following the Myers' procedure to achieve a well-posed action principle
for a Dirichlet boundary condition on the metric, which is proved to be
equivalent to the Hamiltonian formulation for a radial foliation of spacetime.
In turn, a closed expression for the Dirichlet counterterms does not exist for
a generic Lovelock gravity. The second method supplements the bulk action with
boundary terms which depend on the extrinsic curvature (Kounterterms), and
whose explicit form is independent of the particular theory considered.
  In this paper, we use Dimensionally Continued AdS Gravity (Chern-Simons-AdS
in odd and Born-Infeld-AdS in even dimensions) as a toy model to perform the
first explicit comparison between both regularization prescriptions. This can
be done thanks to the fact that, in this theory, the Dirichlet counterterms can
be readily integrated out from the divergent part of the Dirichlet variation of
the action.
  The agreement between both procedures at the level of the boundary terms
suggests the existence of a general property of any Lovelock-AdS gravity:
intrinsic counterterms are generated as the difference between the Kounterterm
series and the corresponding Gibbons-Hawking-Myers term.


title: The Infrared Properties of Hickson Compact Groups

abstract:
  Compact groups of galaxies provide a unique environment to study the
mechanisms by which star formation occurs amid continuous gravitational
encounters. We present 2MASS (JHK), Spitzer IRAC (3.5-8 micron) and MIPS (24
micron) observations of a sample of twelve Hickson Compact Groups (HCGs 2, 7,
16, 19, 22, 31, 42, 48, 59, 61, 62, and 90) that includes a total of 45
galaxies. The near-infrared colors of the sample galaxies are largely
consistent with being dominated by slightly reddened normal stellar
populations. Galaxies that have the most significant PAH and/or hot dust
emission (as inferred from excess 8 micron flux) also tend to have larger
amounts of extinction and/or K-band excess and stronger 24 micron emission, all
of which suggest ongoing star formation activity. We separate the twelve HCGs
in our sample into three types based on the ratio of the group HI mass to
dynamical mass. We find evidence that galaxies in the most gas-rich groups tend
to be the most actively star forming. Galaxies in the most gas-poor groups tend
to be tightly clustered around a narrow range in colors consistent with the
integrated light from a normal stellar population. We interpret these trends as
indicating that galaxies in gas-rich groups experience star formation and/or
nuclear actively until their neutral gas consumed, stripped, or ionized. The
galaxies in this sample exhibit a ``gap'' between gas-rich and gas-poor groups
in infrared color space that is sparsely populated and not seen in the Spitzer
First Look Survey sample. This gap may suggest a rapid evolution of galaxy
properties in response to dynamical effects. These results suggest that the
global properties of the groups and the local properties of the galaxies are
connected.


title: Disorder induced transition into a one-dimensional Wigner glass

abstract:
  The destruction of quasi-long range crystalline order as a consequence of
strong disorder effects is shown to accompany the strict localization of all
classical plasma modes of one-dimensional Wigner crystals at T=0. We construct
a phase diagram that relates the structural phase properties of Wigner crystals
to a plasmon delocalization transition recently reported. Deep inside the
strictly localized phase of the strong disorder regime, we observe
``glass-like'' behavior. However, well into the critical phase with a plasmon
mobility edge, the system retains its crystalline composition. We predict that
a transition between the two phases occurs at a critical value of the relative
disorder strength. This transition has an experimental signature in the AC
conductivity as a local maximum of the largest spectral amplitude as a function
of the relative disorder strength.


title:
The Nonlinear Evolution of Instabilities Driven by Magnetic Buoyancy: A
  New Mechanism for the Formation of Coherent Magnetic Structures

abstract:
  Motivated by the problem of the formation of active regions from a
deep-seated solar magnetic field, we consider the nonlinear three-dimensional
evolution of magnetic buoyancy instabilities resulting from a smoothly
stratified horizontal magnetic field. By exploring the case for which the
instability is continuously driven we have identified a new mechanism for the
formation of concentrations of magnetic flux.


title:
The Persistence of High-Frequency Spin Fluctuations in Overdoped
  La$_{2-x}$Sr$_{x}$CuO$_{4}$ ($x$=0.22)

abstract:
  We report a detailed inelastic neutron scattering study of the collective
magnetic excitations of overdoped superconducting La1.78Sr0.22CuO4 for the
energy range 0-160 meV. Our measurements show that overdoping suppresses the
strong response present for optimally doped La2-xSrxCuO4 which is peaked near
50 meV. The remaining response is peaked at incommensurate wavevectors for all
energies investigated. We observe a strong high-frequency magnetic response for
E >= 80 meV suggesting that significant antiferromagnetic exchange couplings
persist well into the overdoped part of the cuprate phase diagram.


title: Electric Flux Tube in Magnetic Plasma

abstract:
  In this paper we study a methodical problem related to the magnetic scenario
recently suggested and initiated by the authors \cite{Liao_ES_mono} to
understand the strongly coupled quark-gluon plasma (sQGP): the electric flux
tube in monopole plasma. A macroscopic approach, interpolating between Bose
condensed (dual superconductor) and classical gas medium is developed first.
Then we work out a microscopic approach based on detailed quantum mechanical
calculation of the monopole scattering on electric flux tube, evaluating
induced currents for all partial waves. As expected, the flux tube looses its
stability when particles can penetrate it: we make this condition precise by
calculating the critical value for the product of the flux tube size times the
particle momentum, above which the flux tube dissolves. Lattice static
potentials indicate that flux tubes seem to dissolve at $T>T_{dissolution}
\approx 1.3 T_c$. Using our criterion one gets an estimate of the magnetic
density $n\approx 4.4 \sim 6.6 fm^{-3}$ at this temperature.


title:
Flux enhancement and multistability induced by time delays in a feedback
  controlled flashing ratchet

abstract:
  Feedback controlled ratchets are thermal rectifiers that use information on
the state of the system to operate. We study the effects of time delays in the
feedback for a protocol that performs an instantaneous maximization of the
center-of-mass velocity in the many particle case. For small delays the
center-of-mass velocity decreases for increasing delays (although not as fast
as in the few particle case). However, for large delays we find the surprising
result that the presence of a delay can improve the flux performance of the
ratchet. In fact, the maximum flux obtained with the optimal periodic protocol
is attained. This implies that the delayed feedback protocol considered can
perform better than its non-delayed counterpart. The improvement of the flux
observed in the presence of large delays is the result of the emergence of a
new dynamical regime where the presence of the delayed feedback stabilizes
quasiperiodic solutions that resemble the solutions obtained in a certain
closed-loop protocol with thresholds. In addition, in this new regime the
system presents multistability, i.e. several quasiperiodic solutions can be
stable for a fixed time delay.


title:
Surface Brightness Fluctuations from archival ACS images: a stellar
  population and distance study

abstract:
  We derive Surface Brightness Fluctuations (SBF) and integrated magnitudes in
the V- and I-bands using Advanced Camera for Surveys (ACS) archival data. The
sample includes 14 galaxies covering a wide range of physical properties:
morphology, total absolute magnitude, integrated color. We take advantage of
the latter characteristic of the sample to check existing empirical
calibrations of absolute SBF magnitudes both in the I- and V-passbands.
Additionally, by comparing our SBF and color data with the Teramo-SPoT simple
stellar population models, and other recent sets of population synthesis
models, we discuss the feasibility of stellar population studies based on
fluctuation magnitudes analysis. The main result of this study is that
multiband optical SBF data and integrated colors can be used to significantly
constrain the chemical composition of the dominant stellar system in the
galaxy, but not the age in the case of systems older than 3 Gyr.
  SBF color gradients are also detected and analyzed. These SBF gradient data,
together with other available data, point to the existence of mass dependent
metallicity gradients in galaxies, with the more massive objects showing a
non--negligible SBF versus color gradient. The comparison with models suggests
that such gradients imply more metal rich stellar populations in the galaxies'
inner regions with respect to the outer ones.


title: Experimental Results on |Vcb| and b -> c l nu Transitions

abstract:
  A review of recent analyses on semileptonic decays of B mesons into charmed
final states is given. |Vcb| is extracted both by the Babar and the Belle
collaboration from their datasets using inclusively and exclusively
reconstructed final states.
  In addition there are recent results on the determination of exclusive
branching fractions to the ground states D and D*, as well as to excited D**
states. Those play an important role in understanding the composition of the
total decay width. They represent also a sizable fraction of the backgrounds
for exclusive analyses and are presented here as well.


title:
Density Matrix Renormalization Group Study of Incompressible Fractional
  Quantum Hall States

abstract:
  We develop the Density Matrix Renormalization Group (DMRG) technique for
numerically studying incompressible fractional quantum Hall (FQH) states on the
sphere. We calculate accurate estimates for ground state energies and
excitationgaps at FQH filling fractions \nu=1/3 and \nu=5/2 for systems that
are almost twice as large as the largest ever studied by exact diagonalization.
We establish, by carefully comparing with existing numerical results on smaller
systems, that DMRG is a highly effective numerical tool for studying
incompressible FQH states.


title: Two flavor QCD and confinement - II

abstract:
  This paper is part of a program of investigation of the chiral transition in
Nf=2 QCD, started in Phys.Rev.D72:114510,2005. Progress is reported on the
understanding of some possible systematic errors. A direct test of first order
scaling is presented.


title: Notes on D-branes and dualities in (p,q) minimal superstring theory

abstract:
  We study boundary states in (p,q) minimal superstring theory, combining the
explicit form of matter wave functions. Within the modular bootstrap framework,
Cardy states of (p,q) minimal superconformal field theory are completely
determined in both cases of the different supercharge combinations, and the
remaining consistency checks in the super-Liouville case are also performed.
Using these boundary states, we determine the explicit form of FZZT- and
ZZ-brane boundary states both in type 0A and 0B GSO projections. Annulus
mplitudes of FZZT branes are evaluated and principal FZZT branes are
identified. In particular, we found that these principal FZZT branes do not
satisfy Cardy's consistency conditions for each other and play a role of
order/disorder parameters of the Kramers-Wannier duality in spacetime of this
superstring theory.


title: Chaos at the border of criticality

abstract:
  The present paper points out to a novel scenario for formation of chaotic
attractors in a class of models of excitable cell membranes near an
Andronov-Hopf bifurcation (AHB). The mechanism underlying chaotic dynamics
admits a simple and visual description in terms of the families of
one-dimensional first-return maps, which are constructed using the combination
of asymptotic and numerical techniques. The bifurcation structure of the
continuous system (specifically, the proximity to a degenerate AHB) endows the
Poincare map with distinct qualitative features such as unimodality and the
presence of the boundary layer, where the map is strongly expanding. This
structure of the map in turn explains the bifurcation scenarios in the
continuous system including chaotic mixed-mode oscillations near the border
between the regions of sub- and supercritical AHB. The proposed mechanism
yields the statistical properties of the mixed-mode oscillations in this
regime. The statistics predicted by the analysis of the Poincare map and those
observed in the numerical experiments of the continuous system show a very good
agreement.


title: HyperKahler and quaternionic Kahler manifolds with S^1-symmetries

abstract:
  We study relations between quaternionic Riemannian manifolds admitting
different types of symmetries. We show that any hyperKahler manifold admitting
hyperKahler potential and triholomorphic action of S^1 can be constructed from
another hyperKahler manifold (of lower dimention) with an action of S^1 which
fixes one complex structure and rotates the other two and vice versa. We also
study corresponding quaternionic Kahler manifolds equipped with a quaternionic
Kahler action of the circle. In particular we show that any positive
quaternionic Kahler manifold with S^1 symmetry admits a Kahler metric on an
open everywhere dense subset.


title: F(R) gravity in purely affine formulation

abstract:
  The purely affine, metric-affine and purely metric formulation of general
relativity are dynamically equivalent and the relation between them is
analogous to the Legendre relation between the Lagrangian and Hamiltonian
dynamics. We show that one cannot construct a dynamically equivalent, purely
affine Lagrangian from a metric-affine or metric F(R) Lagrangian, nonlinear in
the curvature scalar. Thus the equivalence between the purely affine picture
and the two other formulations does not hold for metric-affine and metric
theories of gravity with a nonlinear dependence on the curvature, i.e. F(R)
gravity does not have a purely affine formulation. We also show that this
equivalence is restored if the metric tensor is conformally transformed from
the Jordan to the Einstein frame, in which F(R) gravity turns into general
relativity with a scalar field. This peculiar behavior of general relativity,
among relativistic theories of gravitation, with respect to purely affine,
metric-affine and purely metric variation could indicate the physicality of the
Einstein frame. On the other hand, it could explain why this theory cannot
interpolate among phenomenological behaviors at different scales.


title: Black chain of pearls in 5D de Sitter spacetime

abstract:
  We analyze some exact chain-shaped black hole solutions in 5-dimensional
spacetime. Unlike usual black string and black ring solutions, the topology of
the horizons of the new solutions are neither $\mathbb{R}\times R^{2}$ nor
$S^1\times S^2$ but rather like several topological spheres concatenating each
other at single points. The shape of the horizon suggests the name \emph{black
chain of pearls} on which each \emph{pearl} is a topological 3-sphere on the
chain. In addition to the usual black hole hairs, the number of pearls can be
viewed as a new hair of the black chain of pearls.


title:
Perturbative Quantum Corrections to the Supersymmetric CP^1 Kink with
  Twisted Mass

abstract:
  We present an explicit calculation of the one-loop quantum corrections to the
mass and the two central charges of the kink solution of an N=(2,2)
supersymmetric CP^1 model with twisted mass, using supersymmetry preserving
dimensional regularization adapted to solitons. We find that the quantum
corrections of the mass and one of the central charges are nontrivial (but
saturate the BPS bound), while the other central charge receives no
corrections. The nontrivial central charge correction corresponds to a quantum
anomaly, which in our scheme appears as parity violation in the regulating
extra dimension, and its magnitude is in agreement with exact results obtained
by Dorey on the basis of a massive analog of mirror symmetry from a dual U(1)
gauge theory, confirming also the recent work by Shifman, Vainshtein, and
Zwicky.


title:
On a Teichmueller functor between the categories of complex tori and the
  Effros-Shen algebras

abstract:
  A covariant functor from the category of the complex tori to the category of
the Effros-Shen algebras is constructed. The functor maps isomorphic complex
tori to the stably isomorphic Effros-Shen algebras. Our construction is based
on the Teichmueller theory of the Riemann surfaces.


title: The Optimal Single Copy Measurement for the Hidden Subgroup Problem

abstract:
  The optimization of measurements for the state distinction problem has
recently been applied to the theory of quantum algorithms with considerable
successes, including efficient new quantum algorithms for the non-abelian
hidden subgroup problem. Previous work has identified the optimal single copy
measurement for the hidden subgroup problem over abelian groups as well as for
the non-abelian problem in the setting where the subgroups are restricted to be
all conjugate to each other. Here we describe the optimal single copy
measurement for the hidden subgroup problem when all of the subgroups of the
group are given with equal a priori probability. The optimal measurement is
seen to be a hybrid of the two previously discovered single copy optimal
measurements for the hidden subgroup problem.


title: Experimental characterization of frequency dependent squeezed light

abstract:
  We report on the demonstration of broadband squeezed laser beams that show a
frequency dependent orientation of the squeezing ellipse. Carrier frequency as
well as quadrature angle were stably locked to a reference laser beam at
1064nm. This frequency dependent squeezing was characterized in terms of noise
power spectra and contour plots of Wigner functions. The later were measured by
quantum state tomography. Our tomograph allowed a stable lock to a local
oscillator beam for arbitrary quadrature angles with one degree precision.
Frequency dependent orientations of the squeezing ellipse are necessary for
squeezed states of light to provide a broadband sensitivity improvement in
third generation gravitational wave interferometers. We consider the
application of our system to long baseline interferometers such as a future
squeezed light upgraded GEO600 detector.


title: Quantum Projection in an Ising Spin Liquid

abstract:
  A transverse magnetic field is used to scan the diagonal and off-diagonal
susceptibility of the uniaxial quantum magnet,
$\text{LiHo}_{0.045}\text{Y}_{0.955}\text{F}_4$. Clusters of strongly-coupled
spins act as the primary source for the response functions, which result from a
field-induced quantum projection of the system into a classically forbidden
(meaning non-Ising) regime. Calculations based on spin pairs reproduce only
some features of the data and fail to predict the measured off-diagonal
response, providing evidence of a multi-spin collective state.


title: Isogravity: Toward an Electroweak and Gravitational Unification

abstract:
  We present a model that unites the electroweak interaction with general
relativity without specifying a space-time metric. This is made possible by
embedding the kinetic terms for gravity and electroweak theory using one $\SL$
connection variable. The gauge theory is specified without relying on a
space-time metric. We show that once a symmetry breaking mechanism is
implemented that selects a global time-like direction, the electroweak theory
and general relativity emerges with their associated massless degrees of
freedom; the spin 1 vector boson and the spin 2 graviton.


title: The Evolution of the Cosmic Microwave Background

abstract:
  We discuss the time dependence and future of the Cosmic Microwave Background
(CMB) in the context of the standard cosmological model, in which we are now
entering a state of endless accelerated expansion. The mean temperature will
simply decrease until it reaches the effective temperature of the de Sitter
vacuum, while the dipole will oscillate as the Sun orbits the Galaxy. However,
the higher CMB multipoles have a richer phenomenology. The CMB anisotropy power
spectrum will for the most part simply project to smaller scales, as the
comoving distance to last scattering increases, and we derive a scaling
relation that describes this behaviour. However, there will also be a dramatic
increase in the integrated Sachs-Wolfe contribution at low multipoles. We also
discuss the effects of tensor modes and optical depth due to Thomson
scattering. We introduce a correlation function relating the sky maps at two
times and the closely related power spectrum of the difference map. We compute
the evolution both analytically and numerically, and present simulated future
sky maps.


title: Epicyclic Oscillations of Fluid Bodies: Newtonian Nonslender Torus

abstract:
  We study epicyclic oscillations of fluid tori around black holes (in the
Paczynski-Wiita potential) and derive exact analytic expressions for their
radial and vertical eigenfrequencies nu_r and nu_z to second-order accuracy in
the width of the torus. We prove that pressure effects make the
eigenfrequencies smaller than those for free particles. However, the particular
ratio nu_z/nu_r=3/2, which is important for the theory of high-frequency
quasi-periodic oscillations (QPOs), occurs when the fluid tori epicyclic
frequencies nu_r and nu_z are about 15% higher than the ones corresponding to
free particles. Our results therefore suggest that previous estimates of black
hole spins from QPOs have produced values that are too high.


title: Spectroscopic Surveys: Present

abstract:
  I summarize the current spectroscopic sky surveys and some of the scientific
results, emphasizing the largest sky survey to-date, the Sloan Digital Sky
Survey (SDSS). Techniques used commonly in spectral analyses are discussed,
followed by the present needs and challenges for solving some of the unknown
problems. I discuss how the Virtual Observatory (VO) can help astronomers in
carrying out related research.


title: Constants of Geodesic Motion in Higher-Dimensional Black-Hole Spacetimes

abstract:
  In [arXiv:hep-th/0611083] we announced the complete integrability of geodesic
motion in the general higher-dimensional rotating black-hole spacetimes. In the
present paper we prove all the necessary steps leading to this conclusion. In
particular, we demonstrate the independence of the constants of motion and the
fact that they Poisson commute. The relation to a different set of constants of
motion constructed in [arXiv:hep-th/0612029] is also briefly discussed.


title: Electromagnetic Field in Higher-Dimensional Black-Hole Spacetimes

abstract:
  A special test electromagnetic field in the spacetime of the
higher-dimensional generally rotating NUT-(A)dS black hole is found. It is
adjusted to the hidden symmetries of the background represented by the
principal Killing-Yano tensor. Such electromagnetic field generalizes the field
of charged black hole in four dimensions. In higher dimensions, however, the
gravitational back reaction of such a field cannot be consistently solved.