title: Ionization of Rydberg atoms by blackbody radiation

abstract:
  We have studied an ionization of alkali-metal Rydberg atoms by blackbody
radiation (BBR). The results of the theoretical calculations of ionization
rates of Li, Na, K, Rb and Cs Rydberg atoms are presented. Calculations have
been performed for nS, nP and nD states which are commonly used in a variety of
experiments, at principal quantum numbers n=8-65 and at the three ambient
temperatures of 77, 300 and 600 K. A peculiarity of our calculations is that we
take into account the contributions of BBR-induced redistribution of population
between Rydberg states prior to photoionization and field ionization by
extraction electric field pulses. The obtained results show that these
phenomena affect both the magnitude of measured ionization rates and shapes of
their dependences on n. A Cooper minimum for BBR-induced transitions between
bound Rydberg states of Li has been found. The calculated ionization rates are
compared with our earlier measurements of BBR-induced ionization rates of Na nS
and nD Rydberg states with n=8-20 at 300 K. A good agreement for all states
except nS with n>15 is observed. Useful analytical formulas for quick
estimation of BBR ionization rates of Rydberg atoms are presented. Application
of BBR-induced ionization signal to measurements of collisional ionization
rates is demonstrated.


title: Max- Relative Entropy of Entanglement, alias Log Robustness

abstract:
  Properties of the max- relative entropy of entanglement are investigated, and
its significance as an upper bound to the one shot rate for perfect
entanglement dilution, under a particular class of quantum operations, is
discussed. It is shown that it is in fact equal to another known entanglement
monotone, namely the log robustness. It is known that the latter is not
asymptotically continuous and it is not known whether it is weakly additive.
However, by suitably modifying the max- relative entropy of entanglement we
obtain a quantity which is seen to satisfy both these properties. In fact, the
modified quantity is shown to be equal to the regularised relative entropy of
entanglement.


title: Synthesis of superheavies: State of affairs and outlooks

abstract:
  Nuclear reactions leading to formation of new superheavy elements and
isotopes are discussed in the paper. ``Cold'' and ``hot'' synthesis, fusion of
fission fragments, transfer reactions and reactions with radioactive ion beams
are analyzed along with their abilities and limitations. Several most promising
reactions are proposed for experimental study.


title: Algebraic curves, integer sequences and a discrete Painleve transcendent

abstract:
  We consider some bilinear recurrences that have applications in number
theory. The explicit solution of a general three-term bilinear recurrence
relation of fourth order is given in terms of the Weierstrass sigma function
for an associated elliptic curve. The recurrences can generate integer
sequences, including the Somos 4 sequence and elliptic divisibility sequences.
An interpretation via the theory of integrable systems suggests the relation
between certain higher order recurrences and hyperelliptic curves of higher
genus. Analogous sequences associated with a $q$-discrete Painlev\'e I equation
are briefly considered.


title: Dissertation: The Cauchy Problem for Membranes

abstract:
  We show existence and uniqueness for timelike minimal submanifolds in ambient
Lorentz manifolds admitting a time function. The initial value formulation
introduced and the conditions imposed on the initial data are given in purely
geometric terms.


title: Time-dependent modeling of radiative processes in hot magnetized plasmas

abstract:
  Numerical simulations of radiative processes in magnetized compact sources
such as hot accretion disks around black holes, relativistic jets in active
galaxies and gamma-ray bursts are complicated because the particle and photon
distributions span many orders of magnitude in energy, they also strongly
depend on each other, the radiative processes behave significantly differently
depending on the energy regime, and finally due to the enormous difference in
the time-scales of the processes. We have developed a novel computer code for
the time-dependent simulations that overcomes these problems. The processes
taken into account are Compton scattering, electron-positron pair production
and annihilation, Coulomb scattering as well as synchrotron emission and
absorption. No approximation has been made on the corresponding rates. For the
first time, we solve coupled integro-differential kinetic equations for photons
and electrons/positrons without any limitations on the photon and lepton
energies. A numerical scheme is proposed to guarantee energy conservation when
dealing with synchrotron processes in electron and photon equations. We apply
the code to model non-thermal pair cascades in the blackbody radiation field,
to study the synchrotron self-absorption as particle thermalization mechanism,
and to simulate time evolution of stochastically heated pairs and corresponding
synchrotron self-Compton photon spectra which might be responsible for the
prompt emission of gamma-ray bursts. Good agreement with previous works is
found in the parameter regimes where comparison is feasible, with the
differences attributable to our improved treatment of the microphysics.


title: Observation of charge-density-wave excitations in manganites

abstract:
  In the optical conductivity of four different manganites with commensurate
charge order (CO), strong peaks appear in the meV range below the ordering
temperature T_{CO}. They are similar to those reported for one-dimensional
charge density waves (CDW) and are assigned to pinned phasons. The peaks and
their overtones allow one to obtain, for La{1-n/8}Ca{n/8}$MnO{3} with n = 5, 6,
the electron-phonon coupling, the effective mass of the CO system, and its
contribution to the dielectric constant. These results support a description of
the CO in La-Ca manganites in terms of moderately weak-coupling and of the CDW
theory.


title:
Ultrafast active plasmonics: transmission and control of femtosecond
  plasmon signals

abstract:
  We report that femtosecond surface plasmon polariton pulses can propagate
along a metal-dielectric waveguide and that they can be modulated on the
femtosecond timescale by direct ultrafast optical excitation of the metal,
thereby offering unprecedented terahertz plasmonic bandwidth - a key missing
component in the development of surface plasmons as information carriers for
next generation nanophotonic devices.


title:
Two Fuzzy Logic Programming Paradoxes Imply Continuum Hypothesis="False"
  & Axiom of Choice="False" Imply ZFC is Inconsistent

abstract:
  Two different paradoxes of the fuzzy logic programming system of [29] are
presented. The first paradox is due to two distinct (contradictory) truth
values for every ground atom of FLP, one is syntactical, the other is
semantical. The second paradox concerns the cardinality of the valid FLP
formulas which is found to have contradictory values: both $\aleph_0$ the
cardinality of the natural numbers, and $c$, the cardinality of the continuum.
The result is that CH="False" and Axiom of Choice="False". Hence, ZFC is
inconsistent.


title: Partially specified prior

abstract:
  This note introduces the concept of a partially specified prior distribution
for certain post hoc inference problems, where a finite population is sampled
once in order to make a decision on the presence or complete absence of some
attribute. If the decision is made to accept complete absence, a probability
statement may be required that the population is indeed free of the attribute.
A partially specified prior is shown to be advantageous in making such
statements realistic and useful.


title: The Environment of Sy1, Sy2 & Bright IRAS Galaxies

abstract:
  We present a 3-dimensional study of the local (< 100 kpc) environment of Sy1,
Sy2 and Bright IRAS Galaxies. For this purpose we use three galaxy samples
(Sy1, Sy2, BIRG) located at high galactic latitudes as well as three control
sample of non-active galaxies having the same morphological, redshift and
diameter size distributions as the corresponding Seyfert or BIRG sample. Using
the CfA2 and SSRS galaxy catalogues as well as our own spectroscopic
observations, we find that the fraction of BIRGs with a close neighbor is
significantly higher than that of their control sample. We also find that Sy2
galaxies demonstrate the same behaviour with BIRG galaxies but not with Sy1s
which do not show any excess of companions with respect to their control sample
galaxies. An additional analysis of the relation between FIR colors and
activity type of the BIRG's shows a significant difference between the colors
of strongly-interacting and non-interacting starbursts and a resemblance
between the colors of non-interacting starbursts and Sy2s.Our results support
an evolutionary scenario leading from Starbursting to a Sy2 and finally to an
unobscured Sy1 galaxy, where close interactions play the role of the triggering
mechanism.


title: Extended Scaling in High Dimensions

abstract:
  We apply and test the recently proposed "extended scaling" scheme in an
analysis of the magnetic susceptibility of Ising systems above the upper
critical dimension. The data are obtained by Monte Carlo simulations using both
the conventional Wolff cluster algorithm and the Prokof'ev-Svistunov worm
algorithm. As already observed for other models, extended scaling is shown to
extend the high-temperature critical scaling regime over a range of
temperatures much wider than that achieved conventionally. It allows for an
accurate determination of leading and sub-leading scaling indices, critical
temperatures and amplitudes of the confluent corrections.


title:
Simultaneous estimation of the mean and the variance in heteroscedastic
  Gaussian regression

abstract:
  Let $Y$ be a Gaussian vector of $\mathbb{R}^n$ of mean $s$ and diagonal
covariance matrix $\Gamma$. Our aim is to estimate both $s$ and the entries
$\sigma_i=\Gamma_{i,i}$, for $i=1,...,n$, on the basis of the observation of
two independent copies of $Y$. Our approach is free of any prior assumption on
$s$ but requires that we know some upper bound $\gamma$ on the ratio
$\max_i\sigma_i/\min_i\sigma_i$. For example, the choice $\gamma=1$ corresponds
to the homoscedastic case where the components of $Y$ are assumed to have
common (unknown) variance. In the opposite, the choice $\gamma>1$ corresponds
to the heteroscedastic case where the variances of the components of $Y$ are
allowed to vary within some range. Our estimation strategy is based on model
selection. We consider a family $\{S_m\times\Sigma_m, m\in\mathcal{M}\}$ of
parameter sets where $S_m$ and $\Sigma_m$ are linear spaces. To each
$m\in\mathcal{M}$, we associate a pair of estimators
$(\hat{s}_m,\hat{\sigma}_m)$ of $(s,\sigma)$ with values in
$S_m\times\Sigma_m$. Then we design a model selection procedure in view of
selecting some $\hat{m}$ among $\mathcal{M}$ in such a way that the Kullback
risk of $(\hat{s}_{\hat{m}},\hat{\sigma}_{\hat{m}})$ is as close as possible to
the minimum of the Kullback risks among the family of estimators
$\{(\hat{s}_m,\hat{\sigma}_m), m\in\mathcal{M}\}$. Then we derive uniform rates
of convergence for the estimator $(\hat{s}_{\hat{m}},\hat{\sigma}_{\hat{m}})$
over H\"{o}lderian balls. Finally, we carry out a simulation study in order to
illustrate the performances of our estimators in practice.


title: Effects of SN Feedback on the Dark Matter Distribution

abstract:
  We use cosmological simulations to study the effects of supernova (SN)
feedback on the dark matter distribution in galaxies. We simulate the formation
of a Milky-Way type galaxy using a version of the SPH code GADGET2 which
includes chemical enrichment and energy feedback by SN, a multiphase model for
the gas component and metal-dependent cooling. We analyse the impact of the
main three input SN feedback parameters on the amplitude and shape of the dark
matter density profiles, focusing on the inner regions of the halo. In order to
test the dependence of the results on the halo mass, we simulated a scale-down
version of this system. First results of this ongoing work show that the dark
matter distribution is affected by the feedback, through the redistribution of
the baryons. Our findings suggest that the response of the dark matter halo
could be the result of a combination of several physical parameters such as the
amount of stellar mass formed at the centre, its shape, and probably the bursty
characteristics of the star formation rate. As expected, we find that the dark
matter haloes of small galaxies are more sensitive to SN feedback. Higher
resolution simulations are being performed to test for numerical effects.


title:
Populating the galaxy velocity dispersion - supermassive black hole mass
  diagram: A catalogue of (M_bh, sigma) values

abstract:
  An updated catalogue of 76 galaxies with direct supermassive black hole mass
measurements (M_bh) plus, when available, their host bulge's central velocity
dispersion (sigma_0) is provided. Fifty of these mass measurements are
considered reliable, while the others remain somewhat uncertain at this time.
An additional eight stellar systems, including one stellar cluster and three
globular clusters, are listed as hosting potential intermediate mass black
holes < 10^6 M_solar.
  With this larger data set, the demographics within the M_bh-sigma_0 diagram
are briefly explored. Many barred galaxies are shown to be offset from the
M_bh-sigma_0 relation defined by the non-barred galaxies, in the sense that
their velocity dispersions are too high. Furthermore, including 88 AGN with
black hole mass estimates from reverberation mapping studies, we speculate that
barred AGN may follow this same general trend. We also show that some AGN with
sigma_0 < 100 km/s tend to reside up to 0.6 dex above the "barless"
M_bh-sigma_0 relation. Finally, it is shown that ``core galaxies'' appear not
to define an additional subdivision of the M_bh-sigma_0 diagram, although
improved methods for measuring sigma_0-values will be valuable.


title: Burst firing is a neural code in an insect auditory system

abstract:
  Various classes of neurons alternate between high-frequency discharges and
silent intervals. This phenomenon is called burst firing. To analyze burst
activity in an insect system, grasshopper auditory receptor neurons were
recorded in vivo for several distinct stimulus types. The experimental data
show that both burst probability and burst characteristics are strongly
influenced by temporal modulations of the acoustic stimulus. The tendency to
burst, hence, is not only determined by cell-intrinsic processes, but also by
their interaction with the stimulus time course. We study this interaction
quantitatively and observe that bursts containing a certain number of spikes
occur shortly after stimulus deflections of specific intensity and duration.
Our findings suggest a sparse neural code where information about the stimulus
is represented by the number of spikes per burst, irrespective of the detailed
interspike-interval structure within a burst. This compact representation
cannot be interpreted as a firing-rate code. An information-theoretical
analysis reveals that the number of spikes per burst reliably conveys
information about the amplitude and duration of sound transients, whereas their
time of occurrence is reflected by the burst onset time. The investigated
neurons encode almost half of the total transmitted information in burst
activity.


title: Entanglement in a Raman-driven cascaded system

abstract:
  The dynamics of a cascaded system that consists of two atom-cavity subsystems
is studied by using the quantum trajectory method. Considering the two
atom-cavity subsystems driven by a Raman interaction, analytical solutions are
obtained. Subsequently, the entanglement evolution between the two atoms is
studied, and it is shown that the entanglement can be stored by switching off
the Raman coupling. By monitoring the radiation field, the entanglement between
the two atoms can be enhanced.


title:
A generalized logarithmic module and duality of Coxeter
  multiarrangements

abstract:
  We introduce a new definition of a generalized logarithmic module of
multiarrangements by uniting those of the logarithmic derivation and the
differential modules. This module is realized as a logarithmic derivation
module of an arrangement of hyperplanes with a multiplicity consisting of both
positive and negative integers. We consider several properties of this module
including Saito's criterion and reflexivity. As applications, we prove a shift
isomorphism and duality of some Coxeter multiarrangements by using the
primitive derivation.


title:
On the path integral representation for quantum spin models and its
  application to the quantum cavity method and to Monte Carlo simulations

abstract:
  The cavity method is a well established technique for solving classical spin
models on sparse random graphs (mean-field models with finite connectivity).
Laumann et al. [arXiv:0706.4391] proposed recently an extension of this method
to quantum spin-1/2 models in a transverse field, using a discretized
Suzuki-Trotter imaginary time formalism. Here we show how to take analytically
the continuous imaginary time limit. Our main technical contribution is an
explicit procedure to generate the spin trajectories in a path integral
representation of the imaginary time dynamics. As a side result we also show
how this procedure can be used in simple heat-bath like Monte Carlo simulations
of generic quantum spin models. The replica symmetric continuous time quantum
cavity method is formulated for a wide class of models, and applied as a simple
example on the Bethe lattice ferromagnet in a transverse field. The results of
the methods are confronted with various approximation schemes in this
particular case. On this system we performed quantum Monte Carlo simulations
that confirm the exactness of the cavity method in the thermodynamic limit.


title:
Statistical tools used to identify scientific misconduct in mobile phone
  research (REFLEX program)

abstract:
  A severe case of scientific misconduct was discovered in a paper from 2005
allegedly showing harmful effects (DNA breakage) of non-thermal mobile phone
electromagnetic field exposure on human and rat cells. Here we describe the way
how the fraudulent data were identified. The low variations of the reported
biological data are shown to be below theoretical lower limits (multinomial
distributions). Another reason for doubts was highly significant non-equal
distributions of last digits, a known hint towards data fabrication. The
Medical University Vienna, where the research was conducted, was informed about
these findings and came to the conclusion that the data in this and another,
related paper by the same group were fabricated, and that both papers should be
retracted.


title:
Qubit coherence decay down to threshold: influence of substrate
  dimensions

abstract:
  Keeping single-qubit quantum coherence above some threshold value not far
below unity is a prerequisite for fault-tolerant quantum error correction
(QEC). We study the initial dephasing of solid-state qubits in the
independent-boson model, which describes well recent experiments on quantum dot
(QD) excitons both in bulk and in substrates of reduced geometry such as
nanotubes. Using explicit expressions for the exact coherence dynamics, a
minimal QEC rate is identified in terms of the error threshold, temperature,
and qubit-environment coupling strength. This allows us to systematically study
the benefit of a current trend towards substrates with reduced dimensions.


title:
Violations of Bell's inequality for Gaussian states with homodyne
  detection and nonlinear interactions

abstract:
  We show that homodyne measurements can be used to demonstrate violations of
Bell's inequality with Gaussian states, when the local rotations used for these
types of tests are implemented using nonlinear unitary operations. We reveal
that the local structure of the Gaussian state under scrutiny is crucial in the
performance of the test. The effects of finite detection efficiency is
thoroughly studied and shown to only mildly affect the revelation of Bell
violations. We speculate that our approach may be extended to other
applications such as entanglement distillation where local operations are
necessary elements besides quantum entanglement.


title:
Derivation of Maxwell's equations via the covariance requirements of the
  special theory of relativity, starting with Newton's laws

abstract:
  A connection between Maxwell's equations, Newton's laws, and the special
theory of relativity is established with a derivation that begins with Newton's
verbal enunciation of his first two laws. Derived equations are required to be
covariant, and a simplicity criterion requires that the four-vector force on a
charged particle be linearly related to the four-vector velocity. The
connecting tensor has derivable symmetry properties and contains the electric
and magnetic field vectors. The Lorentz force law emerges, and Maxwell's
equations for free space emerge with the assumption that the tensor and its
dual must both satisfy first order partial differential equations. The
inhomogeneous extension yields a charge density and a current density as being
the source of the field, and yields the law of conservation of charge. Newton's
third law is reinterpreted as a reciprocity statement, which requires that the
charge in the source term can be taken as the same physical entity as that of
the test particle and that both can be assigned the same units. Requiring
covariance under either spatial inversions or time reversals precludes magnetic
charge being a source of electromagnetic fields that exert forces on electric
charges.


title: Entropic Stochastic Resonance

abstract:
  We present a novel scheme for the appearance of Stochastic Resonance when the
dynamics of a Brownian particle takes place in a confined medium. The presence
of uneven boundaries, giving rise to an entropic contribution to the potential,
may upon application of a periodic driving force result in an increase of the
spectral amplification at an optimum value of the ambient noise level. This
Entropic Stochastic Resonance (ESR), characteristic of small-scale systems, may
constitute a useful mechanism for the manipulation and control of
single-molecules and nano-devices.


title: Spiky Strings on AdS(4) X CP**3

abstract:
  We study a giant magnon and a spike solution for the string rotating on
AdS(4) X CP**3 geometry. We consider rigid rotating fundamental string in the
SU(2) X SU(2) sector inside the CP**3 and find out the general form of all the
conserved charges. We find out the dispersion relation corresponding to both
the known giant magnon and the new spike solutions. We further study the finite
size correction in both cases.


title:
Nonsinusoidal current-phase relation in strongly ferromagnetic and
  moderately disordered SFS junctions

abstract:
  We study the Josephson current in a junction comprising two superconductors
linked by a strong ferromagnet in presence of impurities. We focus on a regime
where the electron (and hole) motion is ballistic over the exchange length and
diffusive on the scale of the weak link length. The current-phase relation is
obtained for both two- and three dimensional ferromagnetic weak links. In the
clean limit, the possibility of temperature-induced 0- transitions is
demonstrated while the corresponding critical current versus temperature
dependences are also studied.


title: Influence of doping on the Hall coefficient in Sr_{14-x}Ca_xCu_24O_41

abstract:
  We present Hall-effect measurements of two-leg ladder compounds
Sr_{14-x}Ca_xCu_24O_41 (0 <= x <= 11.5) with the aim to determine the number of
carriers participating in dc transport. Distribution of holes between the
ladder and chain subsystems is one of the crucial questions important for
understanding the physics of these compounds. Our Hall effect and resistivity
measurements show typical semiconducting behavior for x < 11.5. However, for
x=11.5, the results are completely different, and the Hall coefficient and
resistivity behavior is qualitatively similar to that of high temperature
copper-oxide superconductors. We have determined the effective number of
carriers at room temperature and compared it to the number of holes in the
ladders obtained by other experimental techniques. We propose that going from
x=0 to x=11.5 less than 1 hole per formula unit is added to the ladders and is
responsible for a pronounced change in resistivity with Ca doping.


title:
Coincidences between Gravitational Wave Interferometers and High Energy
  Neutrino Telescopes

abstract:
  Sources of gravitational waves (GW) and emitters of high energy (HE)
neutrinos both involve compact objects and matter moving at relativistic
speeds. GW emission requires a departure from spherical symmetry, which is the
case if clumps of matter are accreted around black holes or neutron stars, and
ejected in relativistic jets, where neutrinos are believed to be produced. Both
messengers interact weakly with the surrounding matter, hence point directly to
the heart of the engines that power these emissions. Coincidences between GW
interferometers (e.g. Virgo) and HE neutrino telescopes (e.g. Antares) would
then give a unique insight on the physics of the most powerful objects in the
Universe. The possibility, observability and detectability for such GW/HE
neutrino coincidences are analysed.


title: Comparing two samples by penalized logistic regression

abstract:
  Inference based on the penalized density ratio model is proposed and studied.
The model under consideration is specified by assuming that the log--likelihood
function of two unknown densities is of some parametric form. The model has
been extended to cover multiple samples problems while its theoretical
properties have been investigated using large sample theory. A main application
of the density ratio model is testing whether two, or more, distributions are
equal. We extend these results by arguing that the penalized maximum empirical
likelihood estimator has less mean square error than that of the ordinary
maximum likelihood estimator, especially for small samples. In fact,
penalization resolves any existence problems of estimators and a modified Wald
type test statistic can be employed for testing equality of the two
distributions. A limited simulation study supports further the theory.


title:
Spinodal dewetting of thin films with large interfacial slip:
  implications from the dispersion relation

abstract:
  We compare the dispersion relations for spinodally dewetting thin liquid
films for increasing magnitude of interfacial slip length in the lubrication
limit. While the shape of the dispersion relation, in particular the position
of the maximum, are equal for no-slip up to moderate slip lengths, the position
of the maximum shifts to much larger wavelengths for large slip lengths. Here,
we discuss the implications of this fact for recently developed methods to
assess the disjoining pressure in spinodally unstable thin films by measuring
the shape of the roughness power spectrum. For PS films on OTS covered Si
wafers (with slip length b approx. 1 mum) we predict a 20% shift of the
position of the maximum of the power spectrum which should be detectable in
experiments.


title: A note on grid transfer operators for multigrid methods

abstract:
  The Local Fourier analysis (LFA) is a classic tool to prove convergence
theorems for multigrid methods (MGMs). In particular, we are interested in
optimality that is a convergence speed independent of the size of the involved
matrices. For elliptic partial differential equations (PDEs), a well known
optimality result requires that the sum of the orders of the grid transfer
operators is not lower than the order of the PDE to solve. Analogously, when
dealing with MGMs for Toeplitz matrices in the literature an optimality
condition on the position and on the order of the zeros of the symbols of the
grid transfer operators has been found. In this work we show that in the case
of elliptic PDEs with constant coefficients, the two different approaches lead
to an equivalent condition. We argue that the analysis for Toeplitz matrices is
an algebraic generalization of the LFA, which allows to deal not only with
differential problems but also for instance with integral problems. The
equivalence of the two approaches gives the possibility of using grid transfer
operators with different orders also for MGMs for Toeplitz matrices. We give
also a class of grid transfer operators related to the B-spline's refinement
equation and we study their geometric properties. This analysis suggests
further links between wavelets and multigrid methods. A numerical
experimentation confirms the correctness of the proposed analysis.


title: Stratification in polarization and Faraday rotation in the jet of 3C 120

abstract:
  Very long baseline interferometric observations of the radio galaxy 3C 120
show a systematic presence of gradients in Faraday rotation and degree of
polarization across and along the jet. These are revealed by the passage of
multiple superluminal components throughout the jet as they move out from the
core in a sequence of 12 monthly polarimetric observations taken with the VLBA
at 15, 22, and 43 GHz. The degree of polarization has an asymmetric profile in
which the northern side of the jet is more highly polarized. The Faraday
rotation measure is also stratified across the jet width, with larger values
for the southern side. Superposed on this structure we find a localized region
of high Faraday rotation measure (about 6000 rad/m^2) between approximately 3
and 4 mas from the core. This region of enhanced Faraday rotation may result
from the interaction of the jet with the ambient medium, which may also explain
the stratification in degree of polarization. The data are also consistent with
a helical magnetic field in a two-fluid jet model, consisting of an inner
emitting jet and a sheath of nonrelativistic electrons.


title: Antares/Virgo Coincidences : a feasibility study

abstract:
  Sources of gravitational waves (GW) and emitters of high energy (HE)
neutrinos both involve compact objects and matter moving at relativistic
speeds. Coincidences between Virgo and Antares would give a unique insight on
the physics of the most powerful objects in the Universe. The feasibility of
such GW/HE neutrino coincidences is analysed.


title: Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo

abstract:
  We present very sensitive polarimetry of 55 Cnc and tau Boo in an attempt to
detect the partially polarised reflected light from the planets orbiting these
two stars. 55 Cnc is orbited by a hot Neptune planet (55 Cnc e) at 0.038 AU, a
hot Jupiter planet (55 Cnc b) at 0.11 AU, and at least 3 more distant planets.
The polarisation of this system is very stable, showing no sign of the periodic
variations that would be expected if a short period planet were detected. The
measured standard deviation of the night averaged Stokes Q/I and U/I parameters
is 2.2x10^{-6}. We derive upper limits on the geometric albedo, A_G and
planetary radius using Monte Carlo multiple scattering simulations of a simple
model atmosphere. We assume Rayleigh-like scattering (scaled by the maximum
polarisation, p_m at 90 degrees) and pressure insensitive extinction.
Atmospheres in which multiple scattering plays only a small role have an almost
linear relation between polarisation and A_G. In this case, the 4 sigma upper
limits is A_G<0.13(R/1.2 R_{Jup})^{-2}p_m^{-1} for 55 Cnc e. This suggests that
55 Cnc e is relatively small and not a pure H-He planet. The data do not give a
useful upper limit for 55 Cnc b. tau Boo is orbited by an unusually massive hot
Jupiter planet. The standard deviation in the night averaged Stokes Q/I and U/I
polarisation parameters is 5.1x10^{-6}. The 4 sigma upper limit is
A_G<0.37(R/1.2 R_{Jup})^{-2}p_m^{-1} for tau Boo b. This extends the similar
upper limits reported previously for this planet to longer wavelengths. The
larger scatter in the tau Boo data may be due to the spot activity detected
photometrically by the MOST satellite. These results contrast markedly with the
recent claim of a 3 sigma detection of a periodic polarisation signal from
HD189733 with amplitude P=2x10^{-4}, attributed to the planet HD189733 b.


title: Text Data Mining: Theory and Methods

abstract:
  This paper provides the reader with a very brief introduction to some of the
theory and methods of text data mining. The intent of this article is to
introduce the reader to some of the current methodologies that are employed
within this discipline area while at the same time making the reader aware of
some of the interesting challenges that remain to be solved within the area.
Finally, the articles serves as a very rudimentary tutorial on some of
techniques while also providing the reader with a list of references for
additional study.


title: Exciting gauge field and gravitons in a brane-anti-brane annihilation

abstract:
  In this paper we point out the inevitability of an explosive production of
gauge field and gravity wave during an open string tachyon condensation in a
cosmological setting. We will be particularly studying an example of
brane-anti-brane inflation in a warped throat where inflation ends via tachyon
condensation. We point out that a tachyonic instability helps fragmenting the
homogeneous tachyon and excites gauge field and contributes to the stress
energy tensor which also feeds into the gravity waves.


title:
Phase structure of the massive chiral Gross-Neveu model from
  Hartree-Fock

abstract:
  The phase diagram of the massive chiral Gross-Neveu model (the massive
Nambu-Jona-Lasinio model in 1+1 dimensions) is constructed. In the large N
limit, the Hartree-Fock approach can be used. We find numerically a chiral
crystal phase separated from a massive Fermi gas phase by a 1st order
transition. Using perturbation theory, we also construct the critical sheet
where the homogeneous phase becomes unstable in a 2nd order transition. A
tricritical curve is located. The phase diagram is mapped out as a function of
fermion mass, chemical potential and temperature and compared with the one of
the discrete chiral Gross-Neveu model. As a by-product, we illustrate the
crystal structure of matter at zero temperature for various densities and
fermion masses.


title: Quantum dynamics and transport in a double well system

abstract:
  The simplest one-dimensional model for the studying of non-trivial
geometrical effects is a ring shaped device which is formed by joining two
arms. We explore the possibility to model such a system as a two level system
(TLS). Of particular interest is the analysis of quantum stirring, where it is
not evident that the topology is properly reflected within the framework of the
TLS modeling. On the technical side we provide a practical "neighboring level"
approximation for the analysis of such quantum devices, which remains valid
even if the TLS modeling does not apply.


title:
Strange filamentary structures ("fireballs") around a merger galaxy in
  the Coma cluster of galaxies

abstract:
  We found an unusual complex of narrow blue filaments, bright blue knots, and
H-alpha emitting filaments and clouds, which morphologically resembled a
complex of ``fireballs,'' extending up to 80 kpc south from an E+A galaxy RB199
in the Coma cluster. The galaxy has a highly disturbed morphology indicative of
a galaxy--galaxy merger remnant. The narrow blue filaments extend in straight
shapes toward the south from the galaxy, and several bright blue knots are
located at the southern ends of the filaments. The Rc band absolute magnitudes,
half light radii and estimated masses of the bright knots are -12 - -13 mag,
200 - 300 pc and 10^6-7 Msolar, respectively. Long, narrow H-alpha emitting
filaments are connected at the south edge of the knots. The average color of
the fireballs is B - Rc = 0.5, which is bluer than RB199 (B - R = 0.99),
suggesting that most of the stars in the fireballs were formed within several
times 10^8 yr. The narrow blue filaments exhibit almost no H-alpha emission.
Strong H-alpha and UV emission appear in the bright knots. These
characteristics indicate that star formation recently ceased in the blue
filaments and now continues in the bright knots. The gas stripped by some
mechanism from the disk of RB199 may be traveling in the intergalactic space,
forming stars left along its trajectory. The most plausible fireball formation
mechanism is ram pressure stripping by high-speed collision between the galaxy
and the hot intra-cluster medium. The fireballs may be a snapshot of diffuse
intra-cluster population formation, or halo star population formation in a
cluster galaxy.


title:
Rotating relativistic thin disks as sources of charged and magnetized
  Kerr-NUT spacetimes

abstract:
  A family of models of counterrotating and rotating relativistic thin discs of
infinite extension based on a charged and magnetized Kerr-NUT metric are
constructed using the well-known "displace, cut and reflect" method extended to
solutions of vacuum Einstein-Maxwell equations. The metric considered has as
limiting cases a charged and magnetized Taub-NUT solution and the well known
Kerr-Newman solutions. We show that for Kerr-Newman fields the eigenvalues of
the energy-momentum tensor of the disc are for all the values of the parameters
real quantities so that these discs do not present heat flow in any case,
whereas for charged and magnetized Kerr-NUT and Taub-NUT fields we find always
regions with heat flow. We also find a general constraint over the
counterrotating tangential velocities needed to cast the surface
energy-momentum tensor of the disc as the superposition of two counterrotating
charged dust fluids. We show that, in general, it is not possible to take the
two counterrotating fluids as circulating along electrogeodesics nor take the
two counterrotating tangential velocities as equal and opposite.


title:
Future of the universe in modified gravitational theories: Approaching
  to the finite-time future singularity

abstract:
  We investigate the future evolution of the dark energy universe in modified
gravities including $F(R)$ gravity, string-inspired scalar-Gauss-Bonnet and
modified Gauss-Bonnet ones, and ideal fluid with the inhomogeneous equation of
state (EoS). Modified Friedmann-Robertson-Walker (FRW) dynamics for all these
theories may be presented in universal form by using the effective ideal fluid
with an inhomogeneous EoS without specifying its explicit form. We construct
several examples of the modified gravity which produces accelerating
cosmologies ending at the finite-time future singularity of all four known
types by applying the reconstruction program. Some scenarios to resolve the
finite-time future singularity are presented. Among these scenarios, the most
natural one is related with additional modification of the gravitational action
in the early universe. In addition, late-time cosmology in the non-minimal
Maxwell-Einstein theory is considered. We investigate the forms of the
non-minimal gravitational coupling which generates the finite-time future
singularities and the general conditions for this coupling in order that the
finite-time future singularities cannot emerge. Furthermore, it is shown that
the non-minimal gravitational coupling can remove the finite-time future
singularities or make the singularity stronger (or weaker) in modified gravity.


title: On the homotopy type of the Deligne-Mumford compactification

abstract:
  An old theorem of Charney and Lee says that the classifying space of the
category of stable nodal topological surfaces and isotopy classes of
degenerations has the same rational homology as the Deligne-Mumford
compactification. We give an integral refinement: the classifying space of the
Charney-Lee category actually has the same homotopy type as the moduli stack of
stable curves, and the etale homotopy type of the moduli stack is equivalent to
the profinite completion of the classifying space of the Charney-Lee category.


title: Rico: An Accurate Cosmological Recombination Code

abstract:
  We present Rico, a code designed to compute the ionization fraction of the
Universe during the epoch of hydrogen and helium recombination with an
unprecedented combination of speed and accuracy. This is accomplished by
training the machine learning code Pico on the calculations of a multi-level
cosmological recombination code which self-consistently includes several
physical processes that were neglected previously. After training, Rico is used
to fit the free electron fraction as a function of the cosmological parameters.
While, for example at low redshifts (z<~900), much of the net change in the
ionization fraction can be captured by lowering the hydrogen fudge factor in
Recfast by about 3%, Rico provides a means of effectively using the accurate
ionization history of the full recombination code in the standard cosmological
parameter estimation framework without the need to add new or refined fudge
factors or functions to a simple recombination model. Within the new approach
presented here it is easy to update Rico whenever a more accurate full
recombination code becomes available. Once trained, Rico computes the
cosmological ionization history with negligible fitting error in ~10
milliseconds, a speed-up of at least 10^6 over the full recombination code that
was used here. Also Rico is able to reproduce the ionization history of the
full code to a level well below 0.1%, thereby ensuring that the theoretical
power spectra of CMB fluctuations can be computed to sufficient accuracy and
speed for analysis from upcoming CMB experiments like Planck. Furthermore it
will enable cross-checking different recombination codes across cosmological
parameter space, a comparison that will be very important in order to assure
the accurate interpretation of future cosmic microwave background data.


title:
The VIMOS VLT Deep Survey :Evolution of the major merger rate since z~1
  from spectroscopicaly confirmed galaxy pairs

abstract:
  From the VIMOS VLT Deep Survey we use a sample of 6447 galaxies with I_{AB} <
24 to identify 251 pairs of galaxies, each member with a secure spectroscopic
redshift, which are close in both projected separation and in velocity. We find
that at z ~ 0.9, 10.9 +/- 3.2 % of galaxies with M_B(z) < -18-Qz are in pairs
with separations dr < 20 kpc/h, dv < 500 km/s, and with dM_B < 1.5,
significantly larger than 3.76 +/- 1.71 % at z ~ 0.5; we find that the pair
fraction evolves as (1+z)^m with m = 2.49 +/- 0.56. For brighter galaxies with
M_B(z=0) < -18.77, the pair fraction is higher and its evolution with redshift
is somewhat flatter with m=1.88 \pm 0.40, a property also observed for galaxies
with increasing stellar masses. Early type, dry mergers, pairs increase their
relative fraction from 3 % at z ~ 0.9 to 12 % at z ~ 0.5. We find that the
merger rate evolves as N_{mg}=(9.05 +/- 3.76) * 10^{-4}) * (1+z)^{2.43 +/-
0.76}. We find that the merger rate of galaxies with M_B(z) < -18-Qz has
significantly evolved since z ~ 1. The merger rate is increasing more rapidly
with redshift for galaxies with decreasing luminosities, indicating that the
flat evolution found for bright samples is not universal. The merger rate is
also strongly dependent on the spectral type of galaxies involved, late type
mergers being more frequent in the past, while early type mergers are more
frequent today, contributing to the rise in the local density of early type
galaxies. About 20 % of the stellar mass in present day galaxies with
log(M/M_{sun}) > 9.5 has been accreted through major merging events since z ~
1, indicating that major mergers have contributed significantly to the growth
in stellar mass density of bright galaxies over the last half of the life of
the Universe.


title:
Extracting the Bs - anti-Bs mixing angle from B--> VV decays and
  comments on the puzzling B--> K* l+l- decay

abstract:
  Three different strategies to extract the weak mixing phase phi_s of the Bs
system using B--> VV decays (Bs--> K* anti-K*, Bs--> phi anti-K* and Bs--> phi
phi) are discussed. Those penguin-mediated decays are computed in the framework
of a new combined QCD-Factorisation/Flavour Symmetry Method. Also some comments
on the recent interesting results found by Babar concerning the decay B--> K*
l+l- are included.


title: Relative periodic orbits in transitional pipe flow

abstract:
  A dynamical system description of the transition process in shear flows with
no linear instability starts with a knowledge of exact coherent solutions,
among them travelling waves (TWs) and relative periodic orbits (RPOs). We
describe a numerical method to find such solutions in pipe flow and apply it in
the vicinity of a Hopf bifurcation from a TW which looks to be especially
relevant for transition. The dominant structural feature of the RPO solution is
the presence of weakly modulated streaks. This RPO, like the TW from which it
bifurcates, sits on the laminar-turbulent boundary separating initial
conditions which lead to turbulence from those which immediately relaminarise.


title:
Possible tetraquark states in the $\pi^+ \chi_{c1}$ invariant mass
  distribution

abstract:
  In this article, we assume that there exist hidden charmed tetraquark states
with the spin-parity $J^P=1^-$, and calculate their masses with the QCD sum
rules. The numerical result indicates that the masses of the vector hidden
charmed tetraquark states are about $M_{Z}=(5.12\pm0.15) \rm{GeV}$ or
$M_{Z}=(5.16\pm0.16) \rm{GeV}$, which are inconsistent with the experimental
data on the $\pi^+ \chi_{c1}$ invariant mass distribution.
  The hidden charmed mesons $Z_1$, $Z_2$ or $Z$ may be scalar hidden charmed
tetraquark states, hadro-charmonium resonances or molecular states.


title:
Measurement of fundamental thermal noise limit in a cryogenic sapphire
  frequency standard using bimodal maser oscillations

abstract:
  We report observations of the Schawlow-Townes noise limit in a cryogenic
sapphire secondary frequency standard. The effect causes a fundamental limit to
the frequency stability, and was measured through the novel excitation of a
bimodal maser oscillation of a Whispering Gallery doublet at $12.04 GHz$. The
beat frequency of $10 kHz$ between the oscillations enabled a sensitive probe
for this measurement of fractional frequency instability of
$10^{-14}\tau^{-1/2}$ with only 0.5 $pW$ of output power.


title: Scaling and efficiency determine the irreversible evolution of a market

abstract:
  In setting up a stochastic description of the time evolution of a financial
index, the challenge consists in devising a model compatible with all stylized
facts emerging from the analysis of financial time series and providing a
reliable basis for simulating such series. Based on constraints imposed by
market efficiency and on an inhomogeneous-time generalization of standard
simple scaling, we propose an analytical model which accounts simultaneously
for empirical results like the linear decorrelation of successive returns, the
power law dependence on time of the volatility autocorrelation function, and
the multiscaling associated to this dependence. In addition, our approach gives
a justification and a quantitative assessment of the irreversible character of
the index dynamics. This irreversibility enters as a key ingredient in a novel
simulation strategy of index evolution which demonstrates the predictive
potential of the model.


title:
Refractive Index Enhancement with Vanishing Absorption in an Atomic
  Vapor

abstract:
  We report a proof-of-principle experiment where the refractive index of an
atomic vapor is enhanced while maintaining vanishing absorption of the beam.
The key idea is to drive alkali atoms in a vapor with appropriate control
lasers and induce a gain resonance and an absorption resonance for a probe beam
in a two-photon Raman configuration. The strength and the position of these two
resonances can be manipulated by changing the parameters of the control lasers.
By using the interference between these two resonances, we obtain an enhanced
refractive index without an increase in the absorption.


title: New criteria for the equation of state development: Simple model fluids

abstract:
  Recently we have proposed (J. Chem. Phys. 128 (2008) 134508) a new rescaling
of fluid density $\rho $ by its critical value $\rho_c^{2/3}$ to apply the
corresponding states law for the attractive Yukawa fluids study. Analysis of
precise simulation results allows us to generalize this concept to the case of
simple fluids with different interparticle interactions, like Mie (n,m) and
Sutherland pair potentials. It is shown, that there is a linear relationship
between the critical pressure and critical temperature, as well as the critical
density and inverse critical temperature for these frequently used pair
potentials. As a consequence, the critical compressibility factor of these
model fluids is close to its universal value measured experimentally for
different real substances.


title: On the quantization accuracy of the acoustoelectric current

abstract:
  By deriving analytical formulae for the quantization accuracy of the
acoustoelectric current, we reveal that: 1) the flatness of the current plateau
for the typical present devices has reached the theoretical limit of about
100ppm over a 1/1000 change of the gate voltage; 2) increasing the transport
channel length, and counterintuitively, increasing the acoustic wavelength as
well, would improve the quantization accuracy, and very promisingly up to
0.01ppm as required for a quantum current standard.


title:
Power-law behavior in the quantum-resonant evolution of the delta-kicked
  accelerator

abstract:
  We consider the atom-optical delta-kicked accelerator when the initial
momentum distribution is symmetric. We demonstrate the existence of
quantum-resonant dynamics, and derive analytic expressions for the system
evolution. In particular, we consider the dynamical evolution of the momentum
moments and find that all even-ordered momentum moments exhibit a power law
growth. In the ultracold (zero-temperature) limit the exponent is determined by
the order of the moment, whereas for a broad, thermal initial momentum
distribution the exponent is reduced by one. To demonstrate the power law
behavior explicitly we consider the evolutions of the second- and fourth-order
momentum moments, and cumulants, for an initially Gaussian momentum
distribution corresponding to the Maxwell-Boltzmann distribution of an ideal
gas at thermal equilibrium.


title: Spatio-temporal Functional Regression on Paleo-ecological Data

abstract:
  The influence of climate on biodiversity is an important ecological question.
Various theories try to link climate change to allelic richness and therefore
to predict the impact of global warming on genetic diversity. We model the
relationship between genetic diversity in the European beech forests and curves
of temperature and precipitation reconstructed from pollen databases. Our model
links the genetic measure to the climate curves through a linear functional
regression. The interaction in climate variables is assumed to be bilinear.
Since the data are georeferenced, our methodology accounts for the spatial
dependence among the observations. The practical issues of these extensions are
discussed.


title: New observables in the decay mode anti-B --> anti-K*0 l+ l-

abstract:
  We discuss the large set of observables available from the angular
distributions of the decay anti-B --> anti-K*0 l+ l-. We present a NLO analysis
of all observables based on the QCD factorization approach in the low-dilepton
mass region and an estimate of \Lambda/m_b corrections. Moreover, we discuss
their sensitivity to new physics. We explore the experimental sensitivities at
LHCb (10 fb^-1) and Super-LHCb (100 fb^-1) based on a full-angular fit method
and explore the sensitivity to right handed currents. We also show that the
previously discussed transversity amplitude A_T^(1) cannot be measured at the
LHCb experiment or at future B factory experiments as it requires a measurement
of the spin of the final state particles.


title:
High Field de Haas - van Alphen Studies of the Fermi Surfaces of
  LaMIn$_{5}$ (M = Co, Rh, Ir)

abstract:
  We report measurements of the de Haas - van Alphen effect on a series of
compounds, LaMIn$_{5}$ (M = Co, Rh, Ir). The results show that each of the Co
and Ir Fermi surfaces (FSs) exhibit some portions that are two dimensional and
some portions that are three dimensional. The most two dimensional character is
exhibited in LaCoIn$_{5}$, less two dimensional behavior is seen in
LaIrIn$_{5}$, no part of Fermi surface of LaRhIn$_{5}$ is found to have a two
dimensional character. Thus the two dimensionality of portions of the FSs is
largely determined by the d character of the energy bands while all of the
effective masses remain $\leq$ 1.2. This fact has implications for the causes
of the heavy fermion nature of superconductivity and magnetism in the Ce-based
compounds having the similar composition and structure. All of the measurements
were performed at the National High Magnetic Field Laboratory using either
cantilever magnetometry or field modulation methods.


title: Low-loss Materials for high Q-factor Bragg Reflector Resonators

abstract:
  A Bragg resonator uses dielectric plates within a metallic cavity to confine
the energy within a central free space region. The importance of the
permittivity is shown with a better Q-factor possible using higher permittivity
materials of larger intrinsic dielectric losses. This is because the electric
energy in the reflectors decreases proportionally to the square root of
permittivity and the coupling to the metallic losses decrease linearly. In a
sapphire resonator with a single reflector pair a Q-factor of 2.34x10^5 is
obtained, which may be improved on by up to a factor of 2 using higher
permittivity materials.


title: Algebraic versus topological triangulated categories

abstract:
  The most commonly known triangulated categories arise from chain complexes in
an abelian category by passing to chain homotopy classes or inverting
quasi-isomorphisms. Such examples are called `algebraic' because they originate
from abelian (or at least additive) categories. Stable homotopy theory produces
examples of triangulated categories by quite different means, and in this
context the source categories are usually very `non-additive' before passing to
homotopy classes of morphisms. Because of their origin I refer to these
examples as `topological triangulated categories'.
  In these extended talk notes I explain some systematic differences between
these two kinds of triangulated categories. There are certain properties --
defined entirely in terms of the triangulated structure -- which hold in all
algebraic examples, but which fail in some topological ones. These differences
are all torsion phenomena, and rationally there is no difference between
algebraic and topological triangulated categories.


title: Testing Lorentz Invariance Violation with WMAP Five Year Data

abstract:
  We consider different renormalizable models of Lorentz invariance violation.
We show that the limits on birefringence of the propagation of cosmic microwave
background photons from the five year data of the Wilkinson microwave
anisotropy probe (WMAP) can be translated into a limit of Lorentz symmetry
violation. The obtained limits on Lorentz invariance violation are stronger
than other published limits. We also cast them in terms of limits on a
birefringent effective photo "mass" and on a polarization dependence of the
speed of light.


title: A near-infrared survey of the entire R Corona Australis cloud

abstract:
  To understand low- to intermediate-mass star-formation in the nearby R CrA
molecular cloud, we try to identify the stellar content that is accessible with
near-infrared observations. We obtained a JHK band mosaic of 10 x 60 arcmin
square covering the entire RCrA molecular cloud with unprecedented sensitivity.
We present a catalogue of about 3500 near-infrared sources fainter than the
saturation limit K = 10 mag, reaching K = 18mag. We analysed the extended
sources by inspecting their morphology and point sources by means of
colour-colour and colour-magnitude diagrams. Additionally, we compared the
extinction inferred from the NIR data with the line-of-sight dust emission at
1.2 mm. Sources towards high dust emission but relatively low H-K show a
projected mm-exces; these sources are either immediately surrounded by cold
circumstellar material or, if too red to be a true foreground object, they are
embedded in the front layer of the 1.2 mm emitting dust cloud. In both cases
they are most likely associated with the cloud.


title: Shape Isomerism at N = 40: Discovery of a Proton Intruder in 67Co

abstract:
  The nuclear structure of 67Co has been investigated through 67Fe beta-decay.
The 67Fe isotopes were produced at the LISOL facility in proton-induced fission
of 238U and selected using resonant laser ionization combined with mass
separation. The application of a new correlation technique unambiguously
revealed a 496(33) ms isomeric state in 67Co at an unexpected low energy of 492
keV. A 67Co level scheme has been deduced. Proposed spin and parities suggest a
spherical (7/2-) 67Co ground state and a deformed first excited (1/2-) state at
492 keV, interpreted as a proton 1p-2h prolate intruder state.


title: Calculus of Variations on Time Scales with Nabla Derivatives

abstract:
  We prove a necessary optimality condition of Euler-Lagrange type for
variational problems on time scales involving nabla derivatives of
higher-order. The proof is done using a new and more general fundamental lemma
of the calculus of variations on time scales.


title: A multi-scale approach to the physics of ion beam cancer therapy

abstract:
  We propose a multi-scale approach to understanding physics related to the
ion/proton-beam cancer therapy and calculation of the probability of the DNA
damage as a result of irradiation of patients with energetic (up to 430 MeV/u)
ions. This approach is inclusive with respect to different scales starting from
the long scale defined by the ion stopping followed by a smaller scale defined
by secondary electrons and radicals ending with the shortest scale defined by
interactions of secondaries with the DNA. We present calculations of the
probabilities of single and double strand breaks of the DNA and suggest a way
of further elaboration of such calculations.


title: A decomposition result for the Haar distribution on the orthogonal group

abstract:
  Let H be a Haar distributed random matrix on the group of pxp real orthogonal
matrices. Partition H into four blocks: (1) the (1,1) element, (2)the rest of
the first row, (3) the rest of the first column, and (4)the remaining
(p-1)x(p-1) matrix. The marginal distribution of (1) is well known. In this
paper, we give the conditional distribution of (2) and (3) given (1), and the
conditional distribution of (4) given (1), (2), (3). This conditional
specification uniquely determines the Haar distribution. The two conditional
distributions involve well known probability distributions namely, the uniform
distribution on the unit sphere in p-1 dimensional space and the Haar
distribution on (p-2)x(p-2) orthogonal matrices. Our results show how to
construct the Haar distribution on pxp orthogonal matrices from the Haar
distribution on (p-2)x(p-2) orthogonal matrices coupled with the uniform
distribution on the unit sphere in p-1 dimensions.


title: Spin-Orbit Correlations

abstract:
  We summarize the intuitive connection between deformations of parton
distributions in impact parameter space and single-spin asymmetries. Lattice
results for the $x^2$-moment of the twist-3 polarized parton distribution
$g_2(x)$ are used to estimate the average transverse force acting on the active
quark in SIDIS in the instant after being struck by the virtual photon.


title: The Jones polynomial and the planar algebra of alternating links

abstract:
  It is a well known result from Thistlethwaite that the Jones polynomial of a
non-split alternating link is alternating. We find the right generalization of
this result to the case of non-split alternating tangles. More specifically:
the Jones polynomial of tangles is valued in a certain skein module, we
describe an alternating condition on elements of this skein module, show that
it is satisfied by the Jones invariant of the single crossing tangles, and
prove that it is preserved by appropriately "alternating" planar algebra
compositions. Hence, this condition is satisfied by the Jones polynomial of all
alternating tangles. Finally, in the case of 0-tangles, that is links, our
condition is equivalent to simple alternation of the coefficients of the Jones
polynomial.


title: Will the LHC Look into the Fate of the Universe?

abstract:
  The LHC will probe the nature of the vacuum that determines the properties of
particles and the forces between them. Of particular importance is the fact
that our current theories allow the Universe to be trapped in a metastable
vacuum, which may decay in the distant future, changing the nature of matter.
This could be the case in the Standard Model if the LHC finds the Higgs boson
to be light. Supersymmetry is one favoured extension of the Standard Model
which one might invoke to try to avoid such instability. However, many
supersymmetric models are also condemned to vacuum decay for different reasons.
The LHC will be able to distinguish between different supersymmetric models,
thereby testing the stability of the vacuum, and foretelling the fate of the
Universe.


abstract:
  We study Bragg spectroscopy of a strongly interacting Bose-Einstein
condensate using time-dependent Hartree-Fock-Bogoliubov theory. We include
approximatively the effect of the momentum dependent scattering amplitude which
is shown to be the dominant factor in determining the spectrum for large
momentum Bragg scattering. The condensation of the Bragg scattered atoms is
shown to significantly alter the observed excitation spectrum by creating a
novel pairing channel of mobile pairs.


title: The Shear Viscosity and Thermal Conductivity of Nuclear Pasta

abstract:
  We calculate the shear viscosity $\eta$ and thermal conductivity $\kappa$ of
a nuclear pasta phase in neutron star crusts. This involves complex
non-spherical shapes. We use semiclassical molecular dynamics simulations
involving 40,000 to 100,000 nucleons. The viscosity $\eta$ can be simply
expressed in terms of the height $Z^*$ and width $\Delta q$ of the peak in the
static structure factor $S_p(q)$. We find that $\eta$ increases somewhat,
compared to a lower density phase involving spherical nuclei, because $Z^*$
decreases from form factor and ion screening effects. However, we do not find a
dramatic increase in $\eta$ from non-spherical shapes, as may occur in
conventional complex fluids.


title:
Analytical solution of the equation of motion for a rigid domain wall in
  a magnetic material with perpendicular anisotropy

abstract:
  This paper reports the solution of the equation of motion for a domain wall
in a magnetic material which exhibits high magneto-crystalline anisotropy.
Starting from the Landau-Lifschitz-Gilbert equation for field-induced motion,
we solve the equation to give an analytical expression, which specifies the
domain wall position as a function of time. Taking parameters from a Co/Pt
multilayer system, we find good quantitative agreement between calculated and
experimentally determined wall velocities, and show that high field uniform
wall motion occurs when wall rigidity is assumed.


title: Origin of Star-to-Star Abundance Inhomogeneities in Star Clusters

abstract:
  The mass reinserted by young stars of an emerging massive compact cluster
shows a bimodal hydrodynamic behaviour. In the inner part of the cluster, it is
thermally unstable, while in its outer parts it forms an out-blowing wind. The
chemical homogeneity/inhomogeneity of low/high mass clusters demonstrates the
relevance of this solution to the presence of single/multiple stellar
populations. We show the consequences that the thermal instability of the
reinserted mass has to the galactic super-winds.


title: Tomonaga-Luttinger liquid parameters of magnetic waveguides in graphene

abstract:
  Electronic waveguides in graphene formed by counterpropagating snake states
in suitable inhomogeneous magnetic fields are shown to constitute a realization
of a Tomonaga-Luttinger liquid. Due to the spatial separation of the right- and
left-moving snake states, this non-Fermi liquid state induced by
electron-electron interactions is essentially unaffected by disorder. We
calculate the interaction parameters accounting for the absence of Galilei
invariance in this system, and thereby demonstrate that non-Fermi liquid
effects are significant and tunable in realistic geometries.


title: Giving up the ghost

abstract:
  The Pais-Uhlenbeck model is a quantum theory described by a higher-derivative
field equation. It has been believed for many years that this model possesses
ghost states (quantum states of negative norm) and therefore that this model is
a physically unacceptable quantum theory. The existence of such ghost states
was believed to be attributable to the field equation having more than two
derivatives. This paper shows that the Pais-Uhlenbeck model does not possess
any ghost states at all and that it is a perfectly acceptable quantum theory.
The supposed ghost states in this model arise if the Hamiltonian of the model
is (incorrectly) treated as being Dirac Hermitian (invariant under combined
matrix transposition and complex conjugation). However, the Hamiltonian is {\it
not} Dirac Hermitian, but rather it is PT symmetric. When it is quantized
correctly according to the rules of PT quantum mechanics, the energy spectrum
is real and bounded below and all of the quantum states have positive norm.


title:
Columnar magnetic structure coupled with orthorhombic distortion in the
  antiferromagnetic iron arsenide SrFe$_2$As$_2$

abstract:
  Neutron powder diffraction experiments were carried out on polycrystalline
SrFe$_2$As$_2$ in order to determine the magnetic structure and its
relationship with the crystallographic one. Below $T_0$=205 K, magnetic
reflections appear simultaneously with the onset of the orthorhombic
distortion. From a detailed Rietveld analysis, the magnetic propagation vector
of SrFe$_2$As$_2$ is determined to be {\textit{\textbf{q}}}=(1 0 1); the
coupling of Fe moments is antiferromagnetic along the longer $a$ direction
within the Fe-As layer, and the interlayer coupling is antiferromagnetic as
well. The size of the Fe magnetic moment is deduced to be 1.01(3) ${\mu}_{\rm
B}$ with an orientation parallel to the a-axis. The temperature dependence of
the magnetic moment shows excellent agreement with not only that of the muon
precession frequency but also with that of the structural distortion, revealing
the strong coupling of the columnar magnetic order and the structural
distortion in SrFe$_2$As$_2$.


title: Quantum decay cannot be completely reversed. The 5% rule

abstract:
  Using an exactly solvable model of the Wigner-Weisskopf atom it is shown that
an unstable quantum state cannot be recovered completely by the procedure
involving detection of the decay products followed by creation of the time
reversed decay products state, as proposed in \cite{Son}. The universal lower
bound on the recovery error is approximately equal to $5% $ of the \emph{error
per cycle} - the dimensionless parameter characterizing decay process in the
Markovian approximation. This result has consequences for the efficiency of
quantum error correction procedures which are based on syndrome measurements
and corrective operations.


title:
Ion-beam therapy: from electron production in tissue like media to DNA
  damage estimations

abstract:
  Radiation damage induced by ion beams is traditionally treated at different
levels of theoretical approaches, for the different scales and mechanisms
involved.We present here details of a combined approach that, from a method at
a nanoscopic scale, attempts to merge with higher scales existing results, by
tuning the analytical method employed when extended to larger scale and so
yielding a consistent picture of the entire process. Results will show the
possibility to get a good agreement with macroscale methods and, on the other
hand, to produce a reliable electron energy spectra to be used for DNA damage
estimations.


title: Quenched large deviation principle for words in a letter sequence

abstract:
  When we cut an i.i.d. sequence of letters into words according to an
independent renewal process, we obtain an i.i.d. sequence of words. In the
\emph{annealed} large deviation principle (LDP) for the empirical process of
words, the rate function is the specific relative entropy of the observed law
of words w.r.t. the reference law of words. In the present paper we consider
the \emph{quenched} LDP, i.e., we condition on a typical letter sequence. We
focus on the case where the renewal process has an \emph{algebraic} tail. The
rate function turns out to be a sum of two terms, one being the annealed rate
function, the other being proportional to the specific relative entropy of the
observed law of letters w.r.t. the reference law of letters, with the former
being obtained by concatenating the words and randomising the location of the
origin. The proportionality constant equals the tail exponent of the renewal
process. Earlier work by Birkner considered the case where the renewal process
has an exponential tail, in which case the rate function turns out to be the
first term on the set where the second term vanishes and to be infinite
elsewhere. In a companion paper the annealed and the quenched LDP are applied
to the collision local time of transient random walks, and the existence of an
intermediate phase for a class of interacting stochastic systems is
established.


title:
Reduced Bloch mode expansion for periodic media band structure
  calculations

abstract:
  Reduced Bloch mode expansion is presented for fast periodic media band
structure calculations. The expansion employs a natural basis composed of a
selected reduced set of Bloch eigenfunctions. The reduced basis is selected
within the irreducible Brillouin zone at high symmetry points determined by the
medium's crystal structure and group theory (and possibly at additional related
points). At each of the reciprocal lattice selection points, a number of Bloch
eigenfunctions are selected up to the frequency range of interest for the band
structure calculations. Since it is common to initially discretize the periodic
unit cell and solution field using some choice of basis, reduced Bloch mode
expansion is practically a secondary expansion that uses a selected set of
Bloch eigenvectors. Such expansion therefore keeps, and builds on, any
favorable attributes a primary expansion approach might exhibit. Being in line
with the well known concept of modal analysis, the proposed approach maintains
accuracy while reducing the computation time by up to two orders of magnitudes
or more depending on the size and extent of the calculations. Results are
presented for phononic, photonic and electronic band structures.


title:
The General Supersymmetric Solution of Topologically Massive
  Supergravity

abstract:
  We find the general fully non-linear solution of topologically massive
supergravity admitting a Killing spinor. It is of plane-wave type, with a null
Killing vector field. Conversely, we show that all solutions with a null
Killing vector are supersymmetric for one or the other choice of sign for the
Chern-Simons coupling constant \mu. If \mu does not take the critical value
\mu=\pm 1, these solutions are asymptotically regular on a Poincar\'e patch,
but do not admit a smooth global compactification with boundary S^1\times\R. In
the critical case, the solutions have a logarithmic singularity on the boundary
of the Poincar\'e patch. We derive a Nester-Witten identity, which allows us to
identify the associated charges, but we conclude that the presence of the
Chern-Simons term prevents us from making a statement about their positivity.
The Nester-Witten procedure is applied to the BTZ black hole.


title: Computational Ghost Imaging

abstract:
  Ghost-imaging experiments correlate the outputs from two photodetectors: a
high spatial-resolution (scanning pinhole or CCD camera) detector that measures
a field which has not interacted with the object to be imaged, and a bucket
(single-pixel) detector that collects a field that has interacted with the
object. We describe a computational ghost-imaging arrangement that uses only a
single-pixel detector. This configuration affords background-free imagery in
the narrowband limit and a 3D sectioning capability. It clearly indicates the
classical nature of ghost-image formation.


title: Quantumness Witnesses

abstract:
  A recently proposed test of quantumness [R. Alicki and N. Van Ryn, J. Phys.
A: Math. Theor. 41 062001 (2008)] is put into a broader mathematical and
physical perspective. The notion of quantumness witness is introduced, in
analogy to entanglement witness, and illustrated by examples of a single qubit
and many-body systems with additive observables. We compare also our proposal
with the quantumness test based on quantum correlations (entanglement) and Bell
inequalities. A class of quantumness witnesses associated to the phase space
representation is also discussed.


title:
Physically Derived Rulesfor Simulating Faceted Crystal Growth using
  Cellular Automata

abstract:
  We derive a set of algorithms for simulating the diffusion-limited growth of
faceted crystals using local cellular automata. This technique has been shown
to work well in reproducing realistic crystal morphologies, and the present
work provides a more rigorous physical foundation that connects the numerical
code to the physics of attachment kinetics and diffusion dynamics. We then
apply these algorithms to examine a novel morphological transition in the
growth of thin plate-like crystals.


title:
A Proximal Decomposition Method for Solving Convex Variational Inverse
  Problems

abstract:
  A broad range of inverse problems can be abstracted into the problem of
minimizing the sum of several convex functions in a Hilbert space. We propose a
proximal decomposition algorithm for solving this problem with an arbitrary
number of nonsmooth functions and establish its convergence. The algorithm
fully decomposes the problem in that it involves each function individually via
its own proximity operator. A significant improvement over the methods
currently in use in the area of inverse problems is that it is not limited to
two nonsmooth functions. Numerical applications to signal and image processing
problems are demonstrated.


title: Character sheaves on disconnected groups, X

abstract:
  We classify the unipotent character sheaves on a fixed connected component of
a reductive algebraic group under a mild hypothesis on the characteristic of
the ground field.


title: Escherlike quasiperiodic heterostructures

abstract:
  We propose quasiperiodic heterostructures associated with the tessellations
of the unit disk by regular hyperbolic triangles. We present explicit
construction rules and explore some of the properties exhibited by these
geometric-based systems.


title: Newton polygons of higher order in algebraic number theory

abstract:
  We develop a theory of arithmetic Newton polygons of higher order, that
provides the factorization of a separable polynomial over a $p$-adic field,
together with relevant arithmetic information about the fields generated by the
irreducible factors. This carries out a program suggested by \O{}. Ore. As an
application, we obtain fast algorithms to compute discriminants, prime ideal
decomposition and integral bases of number fields.


title:
Decay of covariances, uniqueness of ergodic component and scaling limit
  for a class of \nabla\phi systems with non-convex potential

abstract:
  We consider a gradient interface model on the lattice with interaction
potential which is a nonconvex perturbation of a convex potential. Using a
technique which decouples the neighboring vertices sites into even and odd
vertices, we show for a class of non-convex potentials: the uniqueness of
ergodic component for \nabla\phi-Gibbs measures, the decay of covariances, the
scaling limit and the strict convexity of the surface tension.


title:
Embryos grown in the dead zone: Assembling the first protoplanetary
  cores in low mass self-gravitating circumstellar disks of gas and solids

abstract:
  In the borders of the dead zones of protoplanetary disks, the inflow of gas
produces a local density maximum that triggers the Rossby wave instability. The
vortices that form are efficient in trapping solids. We aim to assess the
possibility of gravitational collapse of the solids within the Rossby vortices.
We perform global simulations of the dynamics of gas and solids in a low mass
non-magnetized self-gravitating thin protoplanetary disk with the Pencil code.
We use multiple particle species of radius 1, 10, 30, and 100 cm. The dead zone
is modeled as a region of low viscosity. The Rossby vortices excited in the
edges of the dead zone are very efficient particle traps. Within 5 orbits after
their appearance, the solids achieve critical density and undergo gravitational
collapse into Mars sized objects. The velocity dispersions are of the order of
10 m/s for newly formed embryos, later lowering to less than 1 m/s by drag
force cooling. After 200 orbits, 38 gravitationally bound embryos were formed
inside the vortices, half of them being more massive than Mars. The embryos are
composed primarily of same-sized particles. We conclude that the presence of a
dead zone naturally gives rise to a population of protoplanetary cores in the
mass range of 0.1-0.6 Earth masses, on very short timescales.


title: Gallium Phosphide Photonic Crystal Nanocavities in the Visible

abstract:
  Photonic crystal nanocavities at visible wavelengths are fabricated in a high
refractive index (n>3.2) gallium phosphide membrane. The cavities are probed
via a cross-polarized reflectivity measurement and show resonances at
wavelengths as low as 645 nm at room temperature, with quality factors between
500 and 1700 for modes with volumes 0.7(lambda/n)^3. These structures could be
employed for submicron scale optoelectronic devices in the visible, and for
coupling to novel emitters with resonances in the visible such as nitrogen
vacancy centers, and bio- and organic molecules.


title:
Theory of electric dipole spin resonance in quantum dots: Mean field
  theory with Gaussian fluctuations and beyond

abstract:
  Very recently, the electric dipole spin resonance (EDSR) of single electrons
in quantum dots was discovered by three independent experimental groups.
Remarkably, these observations revealed three different mechanisms of EDSR:
coupling of electron spin to its momentum (spin-orbit), to the operator of its
position (inhomogeneous Zeeman coupling), and to the hyperfine Overhauser field
of nuclear spins. In this paper, I present a unified microscopic theory of
these resonances in quantum dots. A mean field theory, derived for all three
mechanisms and based on retaining only two-spin correlators, justifies applying
macroscopic description of nuclear polarization to the EDSR theory. In the
framework of the mean field theory, a fundamental difference in the time
dependence of EDSR inherent of these mechanisms is revealed; it changes from
the Rabi-type oscillations to a nearly monotonic growth. The theory provides a
regular procedure to account for the higher nuclear-spin correlators that
become of importance for a wider time span and can change the asymptotic
behavior of EDSR. It also allows revealing the effect of electron spin dynamics
on the effective coupling between nuclear spins.


title: Backwards on Minkowski's road. From 4D to 3D Maxwellian electromagnetism

abstract:
  Minkowski's concept of a four-dimensional physical space is a central
paradigm of modern physics. The three-dimensional Maxwellian electrodynamics is
uniquely generalized to the covariant four-dimensional form. Is the (1+3)
decomposition of the covariant four-dimensional form unique? How do the
different sign assumptions of electrodynamics emerge from this decomposition?
Which of these assumptions are fundamental and which of them may be modified?
How does the Minkowski space-time metric emerge from this preliminary
metric-free construction? In this paper we are looking for answers to the
problems mentioned. Our main result is the derivation of four different
possible sets of electrodynamic equations which may occur in different types of
isotropic electromagnetic media. The wave propagation in each of these media is
described by the Minkowskian optical metrics. Moreover, the electric and
magnetic energies are nonnegative in all cases. We also show that the correct
directions of the Lorentz force (as a consequence of the Dufay and the Lenz
rules) hold true for all these cases. However, the differences between these
four types of media must have a physical meaning. In particular, the signs of
the three electromagnetic invariants are different.


title:
Instant Evaluation and Demystification of zeta(n),L(n,chi) that
  Euler,Ramanujan Missed - II

abstract:
  For Hurwitz zeta function, we obtain power series expression in second
variable for its higher order derivatives (with respect to first variable) at
non-positive integer arguments and consequently obtain rapidly decreasing
series expression for Riemann zeta fuction at positive odd integer arguments.
Further, we obtain corresponding results for Dirichlet L-series. We also a
unified proof of various classical identities involving Riemann zeta values.


title: Level set approach for fractional mean curvature flows

abstract:
  This paper is concerned with the study of a geometric flow whose law involves
a singular integral operator. This operator is used to define a non-local mean
curvature of a set. Moreover the associated flow appears in two important
applications: dislocation dynamics and phase field theory for fractional
reaction-diffusion equations. It is defined by using the level set method. The
main results of this paper are: on one hand, the proper level set formulation
of the geometric flow; on the other hand, stability and comparison results for
the geometric equation associated with the flow.


title:
Un cadre de conception pour r\'eunir les mod\`eles d'interaction et
  l'ing\'enierie des interfaces

abstract:
  We present HIC (Human-system Interaction Container), a general framework for
the integration of advanced interaction in the software development process. We
show how this framework allows to reconcile the software development methods
(such MDA, MDE) with the architectural models of software design such as MVC or
PAC. We illustrate our approach thanks to two different types of implementation
for this concept in two different business areas: one software design pattern,
MVIC (Model View Interaction Control) and one architectural model, IM
(Interaction Middleware).


title: Divisibility by 2 and 3 of certain Stirling numbers

abstract:
  The numbers e_p(k,n) defined as min(nu_p(S(k,j)j!): j >= n) appear frequently
in algebraic topology. Here S(k,j) is the Stirling number of the second kind,
and nu_p(-) the exponent of p. The author and Sun proved that if L is
sufficiently large, then e_p((p-1)p^L + n -1, n) >= n-1+nu_p([n/p]!). In this
paper, we determine the set of integers n for which equality holds in this
inequality when p=2 and 3. The condition is roughly that, in the base-p
expansion of n, the sum of two consecutive digits must always be less than p.


title: Group-quantization of non-linear sigma models: particle on S^2 revisited

abstract:
  We present the quantum mechanics of "partial-trace" non-linear sigma models,
on the grounds of a fully symmetry-based procedure. After the general scheme is
sketched, the particular example of a particle on the two-sphere is explicitly
developed. As a remarkable feature, no explicit constraint treatment is
required nor ordering ambiguities do appear. Moreover, the energy spectrum is
recovered without extra terms in the curvature of the sphere.


title: Equilibrium tuned by a magnetic field in phase separated manganite

abstract:
  We present magnetic and transport measurements on La5/8-yPryCa3/8MnO3 with y
= 0.3, a manganite compound exhibiting intrinsic multiphase coexistence of
sub-micrometric ferromagnetic and antiferromagnetic charge ordered regions.
Time relaxation effects between 60 and 120K, and the obtained magnetic and
resistive viscosities, unveils the dynamic nature of the phase separated state.
An experimental procedure based on the derivative of the time relaxation after
the application and removal of a magnetic field enables the determination of
the otherwise unreachable equilibrium state of the phase separated system. With
this procedure the equilibrium phase fraction for zero field as a function of
temperature is obtained. The presented results allow a correlation between the
distance of the system to the equilibrium state and its relaxation behavior.


title: Testing the accuracy of the overlap criterion

abstract:
  Here we investigate the accuracy of the overlap criterion when applied to a
simple near-integrable model in both its 2D and 3D version. To this end, we
consider respectively, two and three quartic oscillators as the unperturbed
system, and couple the degrees of freedom by a cubic, non-integrable
perturbation. For both systems we compute the unperturbed resonances up to
order O(\epsilon^2), and model each resonance by means of the pendulum
approximation in order to estimate the theoretical critical value of the
perturbation parameter for a global transition to chaos. We perform several
surface of sections for the bidimensional case to derive an empirical value to
be compared to our theoretical estimation, being both in good agreement. Also
for the 3D case a numerical estimate is attained that we observe matches the
critical value resulting from theoretical means. This confirms once again that
reckoning resonances up to O(\epsilon^2) suffices in order the overlap
criterion to work out.
  Keywords: {Chaos -- Resonances -- Theoretical and Numerical Methods}


title: Hybrid dark energy

abstract:
  Extending previous results [Phys. Rev. Lett. 97, 081301 (2006)], we explore
the cosmological implications of a new quintessence scenario driven by a slow
rolling homogeneous scalar field whose equation of state behaved as freezing
over the entire cosmic evolution, is approaching -1 today, but will become
thawing in the near future, thereby driving the Universe to an eternal
deceleration. We argue that such a mixed behavior, named \emph{hybrid}, may
reconcile the slight preference of current observational data for freezing
potentials with the impossibility of defining observables in the
String/M-theory context due to the existence of a cosmological event horizon in
asymptotically de Sitter universes as, e.g., pure freezing scenarios.


title:
Order-alpha_s corrections to the quarkonium electromagnetic current at
  all orders in the heavy-quark velocity

abstract:
  We compute in order alpha_s the nonrelativistic QCD (NRQCD) short-distance
coefficients that match quark-antiquark operators of all orders in the
heavy-quark velocity v to the electromagnetic current. We employ a new method
to compute the one-loop NRQCD contribution to the matching condition. The new
method uses full-QCD expressions as a starting point to obtain the NRQCD
contribution, thus greatly streamlining the calculation. Our results show that,
under a mild constraint on the NRQCD operator matrix elements, the NRQCD
velocity expansion for the quark-antiquark-operator contributions to the
electromagnetic current converges. The velocity expansion converges rapidly for
approximate J/psi operator matrix elements.


title: Role of cross helicity in magnetohydrodynamic turbulence

abstract:
  Strong incompressible three-dimensional magnetohydrodynamic turbulence is
investigated by means of high resolution direct numerical simulations. The
simulations show that the configuration space is characterized by regions of
positive and negative cross-helicity, corresponding to highly aligned or
anti-aligned velocity and magnetic field fluctuations, even when the average
cross-helicity is zero. To elucidate the role of cross-helicity, the spectra
and structure of turbulence are obtained in imbalanced regions where
cross-helicity is non-zero. When averaged over regions of positive and negative
cross-helicity, the result is consistent with the simulations of balanced
turbulence. An analytical explanation for the obtained results is proposed.


title: Topological Observations on Multiplicative Additive Linear Logic

abstract:
  As an attempt to uncover the topological nature of composition of strategies
in game semantics, we present a ``topological'' game for Multiplicative
Additive Linear Logic without propositional variables, including cut moves. We
recast the notion of (winning) strategy and the question of cut elimination in
this context, and prove a cut elimination theorem. Finally, we prove soundness
and completeness. The topology plays a crucial role, in particular through the
fact that strategies form a sheaf.


title:
Prediction and measurement of transient responses of first difference
  based chaos control for 1-dimensional maps

abstract:
  Chaotic behavior can be produced from difference equations with unstable
fixed points. Difference equations can be used for algorithms to control the
chaotic behavior by perturbing a system parameter using feedback based on the
first difference of the system value. This results in a system of nonlinear
first order difference equations whose stable fixed point is the controlled
chaotic behavior. Basing the feedback on the first difference produces
distinctly different transient responses than when basing feedback on the error
from the fixed point. Analog electronic circuits provide the experimental
system for testing the chaos control algorithm. The circuits are low-cost,
relatively easy to construct, and therefore provide a useful transition towards
more specialized real-world applications. Here we present predictions and
experimental results for the transient responses of a first difference based
feedback control method applied to a chaotic finite difference 1-dimensional
map. The experimental results are in good agreement with predictions, showing a
variety of behaviors for the transient response, including erratic appearing
non-steady convergence.


title:
Gravitational waves from scattering of stellar-mass black holes in
  galactic nuclei

abstract:
  Stellar mass black holes (BHs) are expected to segregate and form a steep
density cusp around supermassive black holes (SMBHs) in galactic nuclei. We
follow the evolution of a multi-mass system of BHs and stars by numerically
integrating the Fokker-Planck energy diffusion equations for a variety of BH
mass distributions. We find that the BHs "self-segregate'', and that the
rarest, most massive BHs dominate the scattering rate closest to the SMBH (<
0.1 pc). BH--BH binaries form out of gravitational wave emission during BH
encounters. We find that the expected rate of BH coalescence events detectable
by Advanced LIGO is ~1 - 100/yr, depending on the initial mass function of
stars in galactic nuclei and the mass of the most massive BHs. We find that the
actual merger rate is likely ~10 times larger than this due to the intrinsic
scatter of stellar densities in many different galaxies. The BH binaries that
form this way in galactic nuclei have significant eccentricities as they enter
the LIGO band (90% with e > 0.9), and are therefore distinguishable from other
binaries, which circularise before becoming detectable. We also show that
eccentric mergers can be detected to larger distances and greater BH masses
than circular mergers, up to ~ 700 solar masses. Future ground-based
gravitational wave observatories will be able to constrain both the mass
function of BHs and stars in galactic nuclei.


title:
Gravitational Aether and the thermodynamic solution to the cosmological
  constant problem

abstract:
  Cosmological constant problem (in its various versions) is arguably the
deepest gap in our understanding of theoretical physics, the solution to which
may very likely require revisiting the Einstein theory of gravity. In this
letter, I argue that the simplest consistent way to decouple gravity from the
vacuum energy (and hence solve the problem) is through the introduction of an
incompressible gravitational aether fluid. The theory then predicts that
gravitational constant for radiation is 33% larger than that of
non-relativistic matter, which is preferred by most cosmological observations
(with the exception of light element abundances), but is not probed by current
precision tests of gravity. I also show that slow-roll inflation can happen in
this theory, with only minor modifications. Finally, interpreting gravitational
aether as a thermodynamic description of gravity, I propose a
finite-temperature correction to the equation of state of gravity, which would
explain the present-day acceleration of the cosmic expansion as a consequence
of the formation of stellar mass black holes.


title: Extragalactic jets: a new perspective

abstract:
  The power carried by the jet of blazars is large, compared to the luminosity
produced by their accretion disk, and is probably in the form of kinetic energy
of a normal electron-proton plasma. The Poynting flux is modest, as suggested
by the inconspicuous synchrotron luminosity when compared to the high energy
(hard X-rays and gamma-ray) one, assumed to be produced by the inverse Compton
process. It is suggested that the jet power and the SED (Spectral Energy
Distribution) of its emission are linked to the mass of the black hole M and
the accretion rate dot M. This corresponds to a new "blazar sequence" based on
M and dot M instead of only the observed blazar luminosity. These ideas can be
tested quite easily once the AGILE and especially the GLAST satellite
observations, coupled with information in the optical/X-ray band from Swift,
will allow the knowledge of the entire SED of hundreds blazars.


title: Evidence against non-cosmological redshifts of QSOs in SDSS data

abstract:
  In the unusual intrinsic QSO redshift models, QSOs are ejected by active
galaxies with periodic non-cosmological reshifts, thus QSOs are generally
associated with active galaxies, and certain structures will be revealed in the
QSO redshift distribution. As the largest homogeneous sample of QSOs and
galaxies, SDSS data provide the best opportunity to examine this issue. We
review the debates on this issue, focused on those based on SDSS and 2dF data,
and conclude that there is no strong connection between foreground active
galaxies and high-redshift QSOs. The existence of two dips in the SDSS QSO
redshift distribution at z=2.7 and 3.5 has recently re-ignited those
controversial debates on the origin of QSO redshift. It also turned out that
both dips are totally caused by selection effects and after selection effects
have been corrected, the two dips disappear and no structure in the redshift
distribution of SDSS DR5 sample. These results support that the reshifts of
QSOs are cosmological.


title: Linking Short Gamma Ray Bursts and their Host Galaxies

abstract:
  The luminosities of short gamma ray burst host galaxies are anticorrelated
with both the isotropic equivalent gamma ray energy and the gamma ray
luminosity of the explosions. Observational selection effects only strengthen
the significance of this correlation. The correlation may indicate that there
are two physically distinct groups of SGRBs. If so, it requires that the more
luminous class of explosions be associated with the younger class of
progenitors. Alternatively, it could be due to a continuous distribution of
burst and host properties. As one possible explanation, we find that the effect
of binary neutron star masses on inspiral time and energy reservoir produces a
correlation of the appropriate sign, but does not automatically reproduce the
correlation slope or the full range of SGRB energy scales. Any future model of
SGRB progenitors needs to reproduce this correlation.


title:
Electronic Structure and Doping in BaFe$_2$As$_2$ and LiFeAs: Density
  Functional Calculations

abstract:
  We report density functional calculations of the electronic structure and
Fermi surface of the BaFe$_2$As$_2$ and LiFeAs phases including doping via the
virtual crystal approximation. The results show that contrary to a rigid band
picture, the density of states at the Fermi energy is only weakly doping
dependent and that the main effect of doping is a change in the relative sizes
of the electron and hole Fermi surfaces as required by Luttinger's theory. This
is a consequence of a change in As height with doping, in particular a shift of
As towards Fe as holes are introduced in the Fe plane, as might be expected
from simple ionic considerations. The main effect of doping is therefore a
reduction in the degree of nesting of the Fermi surface. This provides a
framework for understanding the approximate electron-hole symmetry in the phase
diagrams of the Fe-As based superconductors.


title: Relativistic Spin Precession in the Double Pulsar

abstract:
  The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly
relativistic orbit that displays a roughly 30-second eclipse when pulsar A
passes behind pulsar B. Describing this eclipse of pulsar A as due to
absorption occurring in the magnetosphere of pulsar B, we successfully use a
simple geometric model to characterize the observed changing eclipse morphology
and to measure the relativistic precession of pulsar B's spin axis around the
total orbital angular momentum. This provides a test of general relativity and
alternative theories of gravity in the strong-field regime. Our measured
relativistic spin precession rate of 4.77 (+0.66,-0.65) degrees per year (68%
confidence level) is consistent with that predicted by general relativity
within an uncertainty of 13%.