title: A prescription for the conditional mass function of dark matter haloes

abstract:
  [ABRIDGED] The unconditional mass function (UMF) of dark matter haloes has
been determined accurately in the literature, showing excellent agreement with
high resolution numerical simulations. However, this is not the case for the
conditional mass function (CMF). We propose a simple analytical procedure to
derive the CMF by rescaling the UMF to the constrained environment using the
appropriate mean and variance of the density field at the constrained point.
This method introduces two major modifications with respect to the standard
re-scaling procedure. First of all, rather than using in the scaling procedure
the properties of the environment averaged over all the conditioning region, we
implement the re-scaling locally. We show that for high masses this
modification may lead to substantially different results. Secondly, we modify
the (local) standard re-scaling procedure in such a manner as to force
normalisation, in the sense that when one integrates the CMF over all possible
values of the constraint multiplied by their corresponding probability
distribution, the UMF is recovered. In practise, we do this by replacing in the
standard procedure the value delta_c (the linear density contrast for collapse)
by certain adjustable effective parameter delta_eff. In order to test the
method, we compare our prescription with the results obtained from numerical
simulations in voids (Gottlober et al. 2003), finding a very good agreement.
Based on these results, we finally present a very accurate analytical fit to
the (accumulated) conditional mass function obtained with our procedure, which
may be useful for any theoretical treatment of the large scale structure.


title: Theory of dendritic growth in the presence of lattice strain

abstract:
  Elastic effects due to lattice strain modify the local equilibrium condition
at the solid-solid interface compared to the classical dendritic growth. Both,
the thermal and the elastic fields are eliminated by the Green's function
techniques and a closed nonlinear integro-differential equation for the
evolution of the interface is derived. In the case of pure dilatation, the
elastic effects lead only to a trivial shift of the transition temperature
while in the case of shear transitions, dendritic patterns are found even for
isotropic surface energy.


title:
Nonlinear estimation for linear inverse problems with error in the
  operator

abstract:
  We study two nonlinear methods for statistical linear inverse problems when
the operator is not known. The two constructions combine Galerkin
regularization and wavelet thresholding. Their performances depend on the
underlying structure of the operator, quantified by an index of sparsity. We
prove their rate-optimality and adaptivity properties over Besov classes.


title:
Anomalous expansion and phonon damping due to the Co spin-state
  transition in RCoO_3 with R = La, Pr, Nd and Eu

abstract:
  We present a combined study of the thermal expansion and the thermal
conductivity of the perovskite series RCoO_3 with R = La, Nd, Pr and Eu. The
well-known spin-state transition in LaCoO_3 is strongly affected by the
exchange of the R ions due to their different ionic radii, i.e. chemical
pressure. This can be monitored in detail by measurements of the thermal
expansion, which is a highly sensitive probe for detecting spin-state
transitions. The Co ions in the higher spin state act as additional scattering
centers for phonons, therefore suppressing the phonon thermal conductivity.
Based on the analysis of the interplay between spin-state transition and heat
transport, we present a quantitative model of the thermal conductivity for the
entire series. In PrCoO_3, an additional scattering effect is active at low
temperatures. This effect arises from the crystal field splitting of the 4f
multiplet, which allows for resonant scattering of phonons between the various
4f levels.


title: Gauge field induced by ripples in graphene

abstract:
  We study the effects of quenched height fluctuations (ripples) in graphene on
the density of states (DOS). We show that at strong ripple disorder a
divergence in the DOS can lead to an ordered ground state. We also discuss the
formation of dislocations in corrugated systems, buckling effects in suspended
samples, and the changes in the Landau levels due to the interplay between a
real magnetic field and the gauge potential induced by ripples.


title: Does human activity widen the tropics?

abstract:
  The progress article - Widening of the tropical belt in a changing climate -
by Seidel et al. (2008) published in the first issue of Nature Geosciences,
summarizes the results of several methods to determine the width of the
tropical zone. All they show evidence that the tropics have been expanding over
the past few decades. We confirm this widening based on one more indicator -
the position of the subtropical centers of high pressure. However, we question
the implication of the authors that the tropics widen in response to human
activity, and suggest as a more probable cause the increasing solar activity.
Consequently, we question their conclusion that this widening may continue into
the future in association with anthropogenic climate change, and suggest that
whether the tropics will continue widening will depend on the future evolution
of solar activity rather than on anthropogenic activity.


title: Perihelion precession in spherically symmetric Kaluza-Klein theories

abstract:
  We consider the perihelion precession and bending of light in a class of
Kaluza-Klein models and show that the "electric redshift" model, proposed in
Zhang (2006) to explain the redshift of Quasars, does not agree with
observations. As Zhang's model only considers the Jordan frame, we also compute
the perihelion precession as seen in the Einstein frame and show that, to
lowest order, the perihelion precession can only be consistent with observation
in the Einstein frame. However, when we consider the corresponding "electric
redshift" in the Einstein frame, we find that the redshift is significantly
lower than for the Jordan frame and is therefore very unlikely to explain the
redshift of quasars.


title: Generalizing Simes' test and Hochberg's stepup procedure

abstract:
  In a multiple testing problem where one is willing to tolerate a few false
rejections, procedure controlling the familywise error rate (FWER) can
potentially be improved in terms of its ability to detect false null hypotheses
by generalizing it to control the $k$-FWER, the probability of falsely
rejecting at least $k$ null hypotheses, for some fixed $k>1$. Simes' test for
testing the intersection null hypothesis is generalized to control the $k$-FWER
weakly, that is, under the intersection null hypothesis, and Hochberg's stepup
procedure for simultaneous testing of the individual null hypotheses is
generalized to control the $k$-FWER strongly, that is, under any configuration
of the true and false null hypotheses. The proposed generalizations are
developed utilizing joint null distributions of the $k$-dimensional subsets of
the $p$-values, assumed to be identical. The generalized Simes' test is proved
to control the $k$-FWER weakly under the multivariate totally positive of order
two (MTP$_2$) condition [J. Multivariate Analysis 10 (1980) 467--498] of the
joint null distribution of the $p$-values by generalizing the original Simes'
inequality. It is more powerful to detect $k$ or more false null hypotheses
than the original Simes' test when the $p$-values are independent. A stepdown
procedure strongly controlling the $k$-FWER, a version of generalized Holm's
procedure that is different from and more powerful than [Ann. Statist. 33
(2005) 1138--1154] with independent $p$-values, is derived before proposing the
generalized Hochberg's procedure. The strong control of the $k$-FWER for the
generalized Hochberg's procedure is established in situations where the
generalized Simes' test is known to control its $k$-FWER weakly.


title: Multidimensional persistence behaviour in an Ising system

abstract:
  We consider a periodic Ising chain with nearest-neighbour and $r$-th
neighbour interaction and quench it from infinite temperature to zero
temperature. The persistence probability $P(t)$, measured as the probability
that a spin remains unflipped upto time $t$, is studied by computer simulation
for suitable values of $r$. We observe that as time progresses, $P(t)$ first
decays as $t^{-0.22}$ (-the {\em first} regime), then the $P(t)-t$ curve has a
small slope (in log-log scale) for some time (-the {\em second} regime) and at
last it decays nearly as $t^{-3/8}$ (-the {\em third} regime). We argue that in
the first regime, the persistence behaviour is the usual one for a
two-dimensional system, in the second regime it is like that of a
non-interacting (`zero-dimensional') system and in the third regime the
persistence behaviour is like that of a one dimensional Ising model. We also
provide explanations for such behaviour.


title: Dual Gravity and Matter

abstract:
  We consider the problem of finding a dual formulation of gravity in the
presence of non-trivial matter couplings. In the absence of matter a dual
graviton can be introduced only for linearised gravitational interactions. We
show that the coupling of linearised gravity to matter poses obstructions to
the usual construction and comment on possible resolutions of this difficulty.


title:
The Connection between Gamma-Ray Bursts and Extremely Metal-Poor Stars
  as Nucleosynthetic Probes of the Early Universe

abstract:
  The connection between the long GRBs and Type Ic Supernovae (SNe) has
revealed the interesting diversity: (i) GRB-SNe, (ii) Non-GRB Hypernovae (HNe),
(iii) X-Ray Flash (XRF)-SNe, and (iv) Non-SN GRBs (or dark HNe). We show that
nucleosynthetic properties found in the above diversity are connected to the
variation of the abundance patterns of extremely-metal-poor (EMP) stars, such
as the excess of C, Co, Zn relative to Fe. We explain such a connection in a
unified manner as nucleosynthesis of hyper-aspherical (jet-induced) explosions
Pop III core-collapse SNe. We show that (1) the explosions with large energy
deposition rate, $\dot{E}_{\rm dep}$, are observed as GRB-HNe and their yields
can explain the abundances of normal EMP stars, and (2) the explosions with
small $\dot{E}_{\rm dep}$ are observed as GRBs without bright SNe and can be
responsible for the formation of the C-rich EMP (CEMP) and the hyper metal-poor
(HMP) stars. We thus propose that GRB-HNe and the Non-SN GRBs (dark HNe) belong
to a continuous series of BH-forming stellar deaths with the relativistic jets
of different $\dot{E}_{\rm dep}$.


title:
Oscillations of the purity in the repeated-measurement-based generation
  of quantum states

abstract:
  Repeated observations of a quantum system interacting with another one can
drive the latter toward a particular quantum state, irrespectively of its
initial condition, because of an {\em effective non-unitary evolution}. If the
target state is a pure one, the degree of purity of the system approaches
unity, even when the initial condition of the system is a mixed state. In this
paper we study the behavior of the purity from the initial value to the final
one, that is unity. Depending on the parameters, after a finite number of
measurements, the purity exhibits oscillations, that brings about a lower
purity than that of the initial state, which is a point to be taken care of in
concrete applications.


title: Quantifying intermittent transport in cell cytoplasm

abstract:
  Active cellular transport is a fundamental mechanism for protein and vesicle
delivery, cell cycle and molecular degradation. Viruses can hijack the
transport system and use it to reach the nucleus. Most transport processes
consist of intermittent dynamics, where the motion of a particle, such as a
virus, alternates between pure Brownian and directed movement along
microtubules. In this communication, we estimate the mean time for particle to
attach to a microtubule network. This computation leads to a coarse grained
equation of the intermittent motion in radial and cylindrical geometries.
Finally, by using the degradation activity inside the cytoplasm, we obtain
refined asymptotic estimations for the probability and the mean time a virus
reaches a small nuclear pore.


title: Describing neutrino oscillations in matter with Magnus expansion

abstract:
  We present new formalism for description of the neutrino oscillations in
matter with varying density. The formalism is based on the Magnus expansion and
has a virtue that the unitarity of the S-matrix is maintained in each order of
perturbation theory. We show that the Magnus expansion provides better
convergence of series: the restoration of unitarity leads to smaller deviations
from the exact results especially in the regions of large transition
probabilities. Various expansions are obtained depending on a basis of neutrino
states and a way one splits the Hamiltonian into the self-commuting and
non-commuting parts. In particular, we develop the Magnus expansion for the
adiabatic perturbation theory which gives the best approximation. We apply the
formalism to the neutrino oscillations in matter of the Earth and show that for
the solar oscillation parameters the second order Magnus adiabatic expansion
has better than 1% accuracy for all energies and trajectories. For the
atmospheric $\Delta m^2$ and small 1-3 mixing the approximation works well ($<
3 %$ accuracy for $\sin^2 \theta_{13} = 0.01$) outside the resonance region
(2.7 - 8) GeV.


title:
Origin of high piezoelectric response of Pb(Zr_xTi_1-x)O_3 at the
  morphotropic phase boundary: Role of elastic instability

abstract:
  Temperature dependent structural changes in a nearly pure monoclinic phase
composition (x=0.525) of Pb(Zr_xTi_1-x)O_3 (PZT) have been investigated using
Rietveld analysis of high-resolution synchrotron powder x-ray diffraction data
and correlated with changes in the dielectric constant and planar
electromechanical coupling coefficient. Our results show that the intrinsic
piezoelectric response of the tetragonal phase of PZT is higher than that of
the monoclinic phase. It is also shown that the high piezoelectric response of
PZT may be linked with an anomalous softening of the elastic modulus (1/S_11)
of the tetragonal compositions closest to the morphotropic phase boundary.


title:
Transport through single-wall metallic carbon nanotubes in the
  cotunneling regime

abstract:
  Using the real-time diagrammatic technique and taking into account both the
sequential and cotunneling processes, we analyze the transport properties of
single-wall metallic carbon nanotubes coupled to nonmagnetic and ferromagnetic
leads in the full range of parameters. In particular, considering the two
different shell filling schemes of the nanotubes, we discuss the behavior of
the differential conductance, tunnel magnetoresistance and the shot noise. We
show that in the Coulomb diamonds corresponding to even occupations, the shot
noise becomes super-Poissonian due to bunching of fast tunneling processes
resulting from the dynamical channel blockade, whereas in the other diamonds
the noise is roughly Poissonian, in agreement with recent experiments. The
tunnel magnetoresistance is very sensitive to the number of electrons in the
nanotube and exhibits a distinctively different behavior depending on the shell
filling sequence of the nanotube.


title:
Is irradiation important for the secular evolution of low-mass X-ray
  binaries?

abstract:
  It is argued that irradiation in low-mass X-ray binaries (LMXBs) caused by
accretion-generated X-rays can not only change the optical appearance of LMXBs
but also their outburst properties and possibly also their long-term evolution.
Irradiation during an outburst of the outer parts of the accretion disc in a
transient LMXB leads to drastic changes in the outburst properties. As far as
the secular evolution of such systems is concerned, these changes can result in
enhanced loss of mass and angular momentum from the system and, most important,
in neutron star LMXBs in a much less efficient use of the transferred matter to
spin up the neutron star to a ms-pulsar. Irradiation of the donor star can
destabilize mass transfer and lead to irradiation-driven mass transfer cycles,
i.e. to a secular evolution which differs drastically from an evolution in
which irradiation is ignored. It is argued that irradiation-driven mass
transfer cycles cannot occur in systems which are transient because of disc
instabilities, i.e. in particular in long-period LMXBs with a giant donor. It
is furthermore shown that for irradiating either the disc or the donor star,
direct irradiation alone is insufficient. Rather, indirect irradiation via
scattered accretion luminosity must play an important role in transient LMXBs
and is, in fact, necessary to destabilize mass transfer in short-period systems
by irradiating the donor star. Whether and to what extent irradiation in LMXBs
does change their secular evolution depends on a number of unsolved problems
which are briefly discussed at the end of this article.


title: On false discovery control under dependence

abstract:
  A popular framework for false discovery control is the random effects model
in which the null hypotheses are assumed to be independent. This paper
generalizes the random effects model to a conditional dependence model which
allows dependence between null hypotheses. The dependence can be useful to
characterize the spatial structure of the null hypotheses. Asymptotic
properties of false discovery proportions and numbers of rejected hypotheses
are explored and a large-sample distributional theory is obtained.


title: Strong Field Approximation for Systems with Coulomb Interaction

abstract:
  A theory describing above-threshold ionization of atoms and ions in a strong
electromagnetic field is presented. It is based on the widely known strong
field approximation and incorporates the Coulomb interaction between the
photoelectron and the nucleus using the method of complex classical
trajectories. A central result of the theory is the Coulomb-corrected
ionization amplitude whose evaluation requires little extra numerical effort.
By comparing our predictions with the results of ab initio numerical solutions
for two examples we show that the new theory provides a significant improvement
of the Coulomb-free strong field approximation. For the case of above-threshold
ionization in elliptically polarized fields a comparison with available
experimental data is also presented.


title:
Resonances for a Hydrogenic System or a Harmonic Oscillator Strongly
  Coupled to a Field

abstract:
  We calculate resonances which are formed by a particle in a potential which
is either Coulombian or quadratic when the particle is strongly coupled to a
massless boson, taking only two energy levels into consideration. From these
calculations we derive how the moving away of the particle from its attraction
center goes together with the energy lowering of hybrid states that this
particle forms with the field. We study the width of these states and we show
that stable states may also appear in the coupling.


title: Westerlund 1 and its Galactic siblings -Observation confronts Theory

abstract:
  Because of their large number of stars spread over the entire stellar mass
spectrum, starburst clusters are highly suitable to benchmark and calibrate
star formation models and theories. Among the handful of Galactic starburst
clusters, Westerlund 1 with its estimated 150 O-stars, W-R stars, supergiants
and hypergiants is the most massive young cluster identified to date in the
Milky Way. While previous studies of Westerlund 1 focused largely on optical
and X-ray observations of its evolved massive stellar population, we have
analyzed near-infrared data, resulting in the first in depth study of the
``lower-mass'' main sequence and pre-main sequence cluster population, i.e., of
stars in the mass range 0.4 to 30 solar masses. The derived properties of the
cluster population allow us to test theoretical evolutionary tracks. By
comparison of Westerlund 1's half-mass radius with younger starburst clusters
like NGC 3603 YC and Arches, and somewhat older massive clusters like RSGC1 and
RSGC2, we find evidence for a rapid dissolution of Galactic starburst clusters,
which has interesting implications for the long-term survival of starburst
clusters, and the question to which extent Galactic starburst clusters might
mimic proto-globular clusters.


title: Compressed Modular Matrix Multiplication

abstract:
  We propose to store several integers modulo a small prime into a single
machine word. Modular addition is performed by addition and possibly
subtraction of a word containing several times the modulo. Modular
Multiplication is not directly accessible but modular dot product can be
performed by an integer multiplication by the reverse integer. Modular
multiplication by a word containing a single residue is a also possible.
Therefore matrix multiplication can be performed on such a compressed storage.
We here give bounds on the sizes of primes and matrices for which such a
compression is possible. We also explicit the details of the required
compressed arithmetic routines.


title:
Late universe dynamics with scale-independent linear couplings in the
  dark sector

abstract:
  We explore the dynamics of cosmological models with two coupled dark
components with energy densities $\rho_A$ and $\rho_B$. We assume that the
coupling is of the form $Q=Hq(\rho_A,\rho_B)$, so that the dynamics of the two
components turns out to be scale independent, i.e. does not depend explicitly
on the Hubble scalar $H$. With this assumption, we focus on the general linear
coupling $q=q_o+q_A\rho_A+q_B\rho_B$, which may be seen as arising from any
$q(\rho_A,\rho_B)$ at late time and leads in general to an effective
cosmological constant. In the second part of the paper we consider
observational constraints on the form of the coupling from SN Ia data, assuming
that one of the components is cold dark matter. We find that the constant part
of the coupling function is unconstrained by SN Ia data and, among typical
linear coupling functions, the one proportional to the dark energy density
$\rho_{A}$ is preferred in the strong coupling regime, $|q_{A}|>1$. While
phantom models favor a positive coupling function, in non-phantom models, not
only a negative coupling function is allowed, but the uncoupled sub-case falls
at the border of the likelihood.


title:
Pointwise existence of the Lyapunov exponent for a quasi-periodic
  equation

abstract:
  In this short note, we describe some recent results on the pointwise
existence of the Lyapunov exponent for certain quasi-periodic cocyles.


title: Optimal control of unilateral obstacle problem with a source term

abstract:
  We consider an optimal control problem for the obstacle problem with an
elliptic variational inequality. The obstacle function which is the control
function is assumed in $H^{2}$. We use an approximate technique to introduce a
family of problems governed by variational equations. We prove optimal
solutions existence and give necessary optimality conditions.


title: Pseudogap-driven Hall effect sign reversal

abstract:
  We present a calculation of the Hall coefficient in 2H-TaSe2 and 2H-Cu0.2NbS2
relied on the photoemission data and compare the results to transport
observations. The approach, based on the solution of the semiclassical
Boltzmann equation in the isotropic tau-approximation yields high-temperature
Hall coefficient consistent with the one measured directly. Taking into account
the opening of the pseudogap and redistribution of the spectral weight,
recently observed in angle resolved photoemission spectra of 2H-TaSe2, allows
us to reproduce the temperature dependence of the Hall coefficient including
prominent sign change with no adjustable parameters.


title: Enhanced Black Hole Horizon Fluctuations

abstract:
  We discuss the possible role of quantum horizon fluctuations on black hole
radiance, especially whether they can invalidate Hawking's analysis based upon
transplanckian modes. We are particularly concerned with ``enhanced''
fluctuations produced by gravitons or matter fields in squeezed vacuum states
sent into the black hole after the collapse process. This allows for the
possibility of increasing the fluctuations well above the vacuum level. We find
that these enhanced fluctuations could significantly alter stimulated emission
but have little effect upon the spontaneous emission. Thus the thermal
character of the Hawking radiation is remarkably robust.


title: Comment on "Typicality for Generalized Microcanonical Ensemble"

abstract:
  The validity of the so-called "typicality" argument for a generalised
microcanonical ensemble proposed recently is examined.


title: Liquid State NMR as a Test-bed for Developing Quantum Control Methods

abstract:
  In building a quantum information processor (QIP), the challenge is to
coherently control a large quantum system well enough to perform an arbitrary
quantum algorithm and to be able to correct errors induced by decoherence.
Nuclear magnetic resonance (NMR) QIPs offer an excellent test-bed on which to
develop and benchmark tools and techniques to control quantum systems. Two main
issues to consider when designing control methods are accuracy and efficiency,
for which two complementary approaches have been developed so far to control
qubit registers with liquid-state NMR methods. The first applies optimal
control theory to numerically optimize the control fields to implement unitary
operations on low dimensional systems with high fidelity. The second technique
is based on the efficient optimization of a sequence of imperfect control
elements so that implementation of a full quantum algorithm is possible while
minimizing error accumulation. This article summarizes our work in implementing
both of these methods. Furthermore, we show that taken together, they form a
basis to design quantum-control methods for a block-architecture QIP so that
large system size is not a barrier to implementing optimal control techniques.


title: Meteoroid and space debris impacts in grazing-incidence telescopes

abstract:
  Micrometeoroid or space debris impacts have been observed in the focal planes
of the XMM-Newton and Swift-XRT X-ray observatories. These impacts have
resulted in damage to, and in one case the failure of, focal-plane
Charge-Coupled Device (CCD) detectors.
  We present a simple model for the propagation of micrometeoroids and space
debris particles into telescopes with grazing incidence X-ray optics. The risks
of future focal-plane impact events in three present (Swift-XRT, XMM-Newton,
and Chandra) and two future (SIMBOL-X and XEUS) X-ray observatories are then
estimated.
  The probabilities of at least one impact occurring in the Swift-XRT,
XMM-Newton, and Chandra focal planes, in a one year period from the time of
writing in November 2007 are calculated to be ~5% and ~50% and ~3%. First-order
predictions of the impact rates expected for the future SIMBOL-X and XEUS X-ray
observatories yield probabilities for at least one focal-plane impact, during
nominal 5-year missions, of more than 94% and 99%, respectively.
  Future X-ray observatories, with large collecting areas and long focal
lengths, may experience much higher impact rates on their focal-plane detectors
than those currently in operation. This should be considered in the design and
planning of future missions.


title: Do Ultraluminous X-Ray Sources Exist in Dwarf Galaxies?

abstract:
  A thorough search for Ultraluminous X-ray source candidates within the Local
Volume is made. The search spatially matches potential ULXs detected in X-ray
images or cataloged in the literature with galaxies tabulated in the Catalog of
Neighboring Galaxies compiled by Karachentsev et al. (2004). The specific ULX
frequency (occurrence rate per unit galaxy mass) is found to be a decreasing
function of host galaxy mass for host masses above $\sim10^{8.5}$ solar mass.
There is too little mass in galaxies below this point to determine if this
trend continues to lower galaxy mass. No ULXs have yet been detected in
lower-mass galaxies. Systematic differences between dwarf and giant galaxies
that may explain an abundance of ULXs in dwarf galaxies and what they may imply
about the nature of ULXs are discussed.


title:
An Investigation of the Sequential Sampling Method for Crossdocking
  Simulation Output Variance Reduction

abstract:
  This paper investigates the reduction of variance associated with a
simulation output performance measure, using the Sequential Sampling method
while applying minimum simulation replications, for a class of JIT (Just in
Time) warehousing system called crossdocking. We initially used the Sequential
Sampling method to attain a desired 95% confidence interval half width of
plus/minus 0.5 for our chosen performance measure (Total usage cost, given the
mean maximum level of 157,000 pounds and a mean minimum level of 149,000
pounds). From our results, we achieved a 95% confidence interval half width of
plus/minus 2.8 for our chosen performance measure (Total usage cost, with an
average mean value of 115,000 pounds). However, the Sequential Sampling method
requires a huge number of simulation replications to reduce variance for our
simulation output value to the target level. Arena (version 11) simulation
software was used to conduct this study.


title: Companion Stars of Type Ia Supernovae

abstract:
  The WD+MS channel of the single-degenerate scenario is currently favourable
for progenitors of type Ia supernovae (SNe Ia). Incorporating the results of
detailed binary evolution calculations for this channel into the latest version
of a binary population synthesis code, I obtained the distributions of many
properties of the companion stars at the moment of SN explosion. The properties
can be verified by future observations.


title: Is dark energy from cosmic Hawking radiation?

abstract:
  It is suggested that dark energy is the energy of the Hawking radiation from
a cosmic horizon. Despite of its extremely low Gibbons-Hawking temperature,
this radiation could have the appropriate magnitude $O(M_P^2 H^2)$ and the
equation of state to explain the observed cosmological data if there is a
Planck scale UV-cutoff, where $H$ is the Hubble parameter.


title: Sharpening The Leading Singularity

abstract:
  We show how studying leading singularities of Feynman diagrams, when all
momenta are complex, gives a simple way of writing multi-loop and
multi-particle scattering amplitudes in N=4 super Yang-Mills. The simplicity of
the method is equivalent to that of the quadruple cut technique introduced in
hep-th/0412103 at one-loop. The new technique only involves the computation of
residues and the solution of linear equations. In our technique both parity
even and parity odd pieces of a coefficient are computed simultaneously and it
is only at the end that a separation can be made if desired. We explain the
procedure via examples. The main example, which we compute in detail, is the
five-particle two-loop amplitude first given in hep-th/0604074. Another feature
of our method is that the helicity structure of the amplitude only enters in
the inhomogeneous part of the linear equations. In other words, the homogeneous
part is universal. We illustrate this feature by presenting the linear
equations which determine a large class of terms for MHV and next-to-MHV
six-particle two-loop amplitudes.


title: Closed-Form Decomposition of One-Loop Massive Amplitudes

abstract:
  We present formulas for the coefficients of 2-, 3-, 4- and 5-point master
integrals for one-loop massive amplitudes. The coefficients are derived from
unitarity cuts in D dimensions. The input parameters can be read off from any
unitarity-cut integrand, as assembled from tree-level expressions, after simple
algebraic manipulations. The formulas presented here are suitable for
analytical as well as numerical evaluation. Their validity is confirmed in two
known cases of helicity amplitudes contributing to gg -> gg and gg -> gH, where
the masses of the Higgs and the fermion circulating in the loop are kept as
free parameters.


title: Subsampling Algorithms for Semidefinite Programming

abstract:
  We derive a stochastic gradient algorithm for semidefinite optimization using
randomization techniques. The algorithm uses subsampling to reduce the
computational cost of each iteration and the subsampling ratio explicitly
controls granularity, i.e. the tradeoff between cost per iteration and total
number of iterations. Furthermore, the total computational cost is directly
proportional to the complexity (i.e. rank) of the solution. We study numerical
performance on some large-scale problems arising in statistical learning.


title: Open cluster stability and the effects of binary stars

abstract:
  The diagnostic age versus mass-to-light ratio diagram is often used in
attempts to constrain the shape of the stellar initial mass function (IMF), and
the potential longevity of extragalactic young to intermediate-age massive star
clusters. Here, we explore its potential for Galactic open clusters. On the
basis of a small, homogenised cluster sample we provide useful constraints on
the presence of significant binary fractions. Using the massive young Galactic
cluster Westerlund 1 as a key example, we caution that stochasticity in the IMF
introduces significant additional uncertainties. We conclude that for an open
cluster to survive for any significant length of time, and in the absence of
substantial external perturbations, it is a necessary but not a sufficient
condition to be located close to or (in the presence of a significant binary
population) somewhat BELOW the predicted photometric evolutionary sequences for
"normal" simple stellar populations (although such a location may be dominated
by a remaining "bound" cluster core and thus not adequately reflect the overall
cluster dynamics).


title:
Achievable Rates and Optimal Resource Allocation for Imperfectly-Known
  Fading Relay Channels

abstract:
  In this paper, achievable rates and optimal resource allocation strategies
for imperfectly-known fading relay channels are studied. It is assumed that
communication starts with the network training phase in which the receivers
estimate the fading coefficients of their respective channels. In the data
transmission phase, amplify-and-forward and decode-and-forward relaying schemes
with different degrees of cooperation are considered, and the corresponding
achievable rate expressions are obtained. Three resource allocation problems
are addressed: 1) power allocation between data and training symbols; 2)
time/bandwidth allocation to the relay; 3) power allocation between the source
and relay in the presence of total power constraints. The achievable rate
expressions are employed to identify the optimal resource allocation
strategies. Finally, energy efficiency is investigated by studying the bit
energy requirements in the low-SNR regime.


title: Improved Squeaky Wheel Optimisation for Driver Scheduling

abstract:
  This paper presents a technique called Improved Squeaky Wheel Optimisation
for driver scheduling problems. It improves the original Squeaky Wheel
Optimisations effectiveness and execution speed by incorporating two additional
steps of Selection and Mutation which implement evolution within a single
solution. In the ISWO, a cycle of
Analysis-Selection-Mutation-Prioritization-Construction continues until
stopping conditions are reached. The Analysis step first computes the fitness
of a current solution to identify troublesome components. The Selection step
then discards these troublesome components probabilistically by using the
fitness measure, and the Mutation step follows to further discard a small
number of components at random. After the above steps, an input solution
becomes partial and thus the resulting partial solution needs to be repaired.
The repair is carried out by using the Prioritization step to first produce
priorities that determine an order by which the following Construction step
then schedules the remaining components. Therefore, the optimisation in the
ISWO is achieved by solution disruption, iterative improvement and an iterative
constructive repair process performed. Encouraging experimental results are
reported.


title:
The Application of Bayesian Optimization and Classifier Systems in Nurse
  Scheduling

abstract:
  Two ideas taken from Bayesian optimization and classifier systems are
presented for personnel scheduling based on choosing a suitable scheduling rule
from a set for each persons assignment. Unlike our previous work of using
genetic algorithms whose learning is implicit, the learning in both approaches
is explicit, i.e. we are able to identify building blocks directly. To achieve
this target, the Bayesian optimization algorithm builds a Bayesian network of
the joint probability distribution of the rules used to construct solutions,
while the adapted classifier system assigns each rule a strength value that is
constantly updated according to its usefulness in the current situation.
Computational results from 52 real data instances of nurse scheduling
demonstrate the success of both approaches. It is also suggested that the
learning mechanism in the proposed approaches might be suitable for other
scheduling problems.


title: Topological Sigma Models with H-Flux

abstract:
  We investigate the topological theory obtained by twisting the N=(2,2)
supersymmetric nonlinear sigma model with target a bihermitian space with
torsion. For the special case in which the two complex structures commute, we
show that the action is a Q-exact term plus a quasi-topological term. The
quasi-topological term is locally given by a closed two-form which corresponds
to a flat gerbe-connection and generalises the usual topological term of the
A-model. Exponentiating it gives a Wilson surface, which can be regarded as a
generalization of a Wilson line. This makes the quantum theory globally
well-defined.


title:
Rational points on homogeneous varieties and Equidistribution of Adelic
  periods

abstract:
  Let U:=L\G be a homogeneous variety defined over a number field K, where G is
a connected semisimple K-group and L is a connected maximal semisimple
K-subgroup of G with finite index in its normalizer.
  Assuming that G(K_v) acts transitively on U(K_v) for almost all places v of
K, we obtain the asymptotic of the number of rational points in U(K) with
height bounded by T, and settle new cases of Manin's conjecture for many
wonderful varieties. The main ingredient of our approach is the
equidistribution of semisimple adelic periods, which is established using the
theory of unipotent flows.


title: Danger Theory: The Link between AIS and IDS?

abstract:
  We present ideas about creating a next generation Intrusion Detection System
based on the latest immunological theories. The central challenge with computer
security is determining the difference between normal and potentially harmful
activity. For half a century, developers have protected their systems by coding
rules that identify and block specific events. However, the nature of current
and future threats in conjunction with ever larger IT systems urgently requires
the development of automated and adaptive defensive tools. A promising solution
is emerging in the form of Artificial Immune Systems. The Human Immune System
can detect and defend against harmful and previously unseen invaders, so can we
not build a similar Intrusion Detection System for our computers.


title:
On the Thermodynamical Relation between Rotating Charged BTZ Black Holes
  and Effective String Theory

abstract:
  In this paper we study the first law of thermodynamics for the (2+1)
dimensional rotating charged BTZ black hole considering a pair of
thermodinamical systems constructed with the two horizons of this solution. We
show that these two systems are similar to the right and left movers of string
theory and that the temperature associated with the black hole is the harmonic
mean of the temperatures associated with these two systems.


title:
Bi-partite entanglement entropy in massive two-dimensional quantum field
  theory

abstract:
  Recently, Cardy, Castro Alvaredo and the author obtained the first
exponential correction to saturation of the bi-partite entanglement entropy at
large region length, in massive two-dimensional integrable quantum field
theory. It only depends on the particle content of the model, and not on the
way particles scatter. Based on general analyticity arguments for form factors,
we propose that this result is universal, and holds for any massive
two-dimensional model (also out of integrability). We suggest a link of this
result with counting pair creations far in the past.


title: On the formation and migration of giant planets in circumbinary discs

abstract:
  We present the results of hydrodynamic simulations of the formation and
subsequent orbital evolution of giant planets embedded in a circumbinary disc.
We assume that a 20 earth masses core has migrated to the edge of the inner
cavity formed by the binary where it remains trapped by corotation torques.
This core is then allowed to accrete gas from the disc, and we study its
orbital evolution as it grows in mass. For each of the two accretion time
scales we considered, we performed three simulations. In two of the three
simulations, we stop the accretion onto the planet once its mass becomes
characteristic of that of Saturn or Jupiter. In the remaining case, the planet
can accrete disc material freely in such a way that its mass becomes higher
than Jupiter's. The simulations show different outcomes depending on the final
mass m_p of the giant. For m_p=1 M_S (where M_S is Saturn's mass), we find that
the planet migrates inward through its interaction with the disc until its
eccentricity becomes high enough to induce a torque reversal. The planet then
migrates outward, and the system remains stable on long time scales. For m_p >
1 M_J (where M_J is Jupiter's mass) we observed two different outcomes. In each
case the planet enters the 4:1 resonance with the binary, and resonant
interaction drives up the eccentricity of the planet until it undergoes a close
encounter with the secondary star. The result can either be ejection from the
system or scattering out into the disc followed by a prolonged period of
outward migration. These results suggest that circumbinary planets are more
likely to be quite common in the Saturn-mass range. Jupiter-mass circumbinary
planets are likely to be less common because of their less stable evolution.


title:
Canonical quantization of gauge fields in static space-times with
  applications to Rindler spaces

abstract:
  The canonical quantization in Weyl gauge of gauge fields in static
space-times is presented. With an appropriate definition of transverse and
longitudinal components of gauge fields, the Gauss law constraint is resolved
explicitly for scalar and spinor QED and a complete non-perturbative solution
is given for the quantized Maxwell-field coupled to external currents. The
formalism is applied in investigations of the electromagnetic field in Rindler
spaces. The relation of creation and annihilation operators in Minkowski and
Rindler spaces is established and initial value problems associated with
bremsstrahlung of a uniformly accelerated charge are studied. The peculiar
scaling properties of scalar and gauge theories in Rindler spaces are discussed
and various quantities such as the photon condensate or the interaction energy
of static charges and of scalar sources are computed.


title:
Negative differential mobility of weakly driven particles in models of
  glass formers

abstract:
  We study the response of probe particles to weak constant driving in
kinetically constrained models of glassy systems, and show that the probe's
response can be non-monotonic and give rise to negative differential mobility:
increasing the applied force can reduce the probe's drift velocity in the force
direction. Oth er significant non-linear effects are also demonstrated, such as
the enhancement with increasing force of the probe's fluctuations away from the
average path, a phenomenon known in other contexts as giant diffusivity. We
show that these res ults can be explained analytically by a continuous-time
random walk approximatio n where there is decoupling between persistence and
exchange times for local dis placements of the probe. This decoupling is due to
dynamic heterogeneity in the glassy system, which also leads to bimodal
distributions of probe particle disp lacements. We discuss the relevance of our
results to experiments.


title: Axiomatic quantum field theory in curved spacetime

abstract:
  The usual formulations of quantum field theory in Minkowski spacetime make
crucial use of features--such as Poincare invariance and the existence of a
preferred vacuum state--that are very special to Minkowski spacetime. In order
to generalize the formulation of quantum field theory to arbitrary globally
hyperbolic curved spacetimes, it is essential that the theory be formulated in
an entirely local and covariant manner, without assuming the presence of a
preferred state. We propose a new framework for quantum field theory, in which
the existence of an Operator Product Expansion (OPE) is elevated to a
fundamental status, and, in essence, all of the properties of the quantum field
theory are determined by its OPE. We provide general axioms for the OPE
coefficients of a quantum field theory. These include a local and covariance
assumption (implying that the quantum field theory is locally and covariantly
constructed from the spacetime metric), a microlocal spectrum condition, an
"associativity" condition, and the requirement that the coefficient of the
identity in the OPE of the product of a field with its adjoint have positive
scaling degree. We prove curved spacetime versions of the spin-statistics
theorem and the PCT theorem. Some potentially significant further implications
of our new viewpoint on quantum field theory are discussed.


title: Traces of H\"ormander algebras on discrete sequences

abstract:
  We show that a discrete sequence $\Lambda$ of the complex plane is the union
of $n$ interpolating sequences for the H\"ormander algebras $A_p$ if and only
if the trace of $A_p$ on $\Lambda$ coincides with the space of functions on
$\Lambda$ for which the divided differences of order $n-1$ are uniformly
bounded. The analogous result holds in the unit disk for Korenblum-type
algebras.


title: Dark Energy Accretion onto black holes in a cosmic scenario

abstract:
  In this paper we study the accretion of dark energy onto a black hole in the
cases that dark energy is equipped with a positive cosmological constant and
when the space-time is described by a Schwarzschild-de Sitter metric. It is
shown that, if confronted with current observational data, the results derived
when no cosmological constant is present are once again obtained in both cases.


title:
Constants of concentration for a simple recurrent random walk on random
  environment

abstract:
  We clarify the asymptotic of the limsup of the size of the neighborhood of
concentration of Sinai's walk improving the result in \cite{Pierre3}. Also we
get the almost sure limit of the number of points visited more than a small but
fixed proportion of a given amount of time.


title: Coherent-feedback quantum control with a dynamic compensator

abstract:
  I present an experimental realization of a coherent-feedback control system
that was recently proposed for testing basic principles of linear quantum
stochastic control theory [M. R. James, H. I. Nurdin and I. R. Petersen, to
appear in IEEE Transactions on Automatic Control (2008),
arXiv:quant-ph/0703150v2]. For a dynamical plant consisting of an optical
ring-resonator, I demonstrate ~ 7 dB broadband disturbance rejection of
injected laser signals via all-optical feedback with a tailored dynamic
compensator. Comparison of the results with a transfer function model pinpoints
critical parameters that determine the coherent-feedback control system's
performance.


title: Dynamics of a Brownian circle swimmer

abstract:
  Self-propelled particles move along circles rather than along a straight line
when their driving force does not coincide with their propagation direction.
Examples include confined bacteria and spermatozoa, catalytically driven
nanorods, active, anisotropic colloidal particles and vibrated granulates.
Using a non-Hamiltonian rate theory and computer simulations, we study the
motion of a Brownian "circle swimmer" in a confining channel. A sliding mode
close to the wall leads to a huge acceleration as compared to the bulk motion,
which can further be enhanced by an optimal effective torque-to-force ratio.


title:
Dynamical density functional theory with hydrodynamic interactions and
  colloids in unstable traps

abstract:
  A density functional theory for colloidal dynamics is presented which
includes hydrodynamic interactions between the colloidal particles. The theory
is applied to the dynamics of colloidal particles in an optical trap which
switches periodically in time from a stable to unstable confining potential. In
the absence of hydrodynamic interactions, the resulting density breathing mode,
exhibits huge oscillations in the trap center which are almost completely
damped by hydrodynamic interactions. The predicted dynamical density fields are
in good agreement with Brownian dynamics computer simulations.


title: A large-scale survey for variable stars in M33

abstract:
  We have started a survey of M 33 in order to find variable stars and Cepheids
in particular. We have obtained more than 30 epochs of g'r'i' data with the
CFHT and the one-square-degree camera MegaCam. We present first results from
this survey, including the search for variable objects and a basic
characterization of the various groups of variable stars.


title:
Raman study of Twin Free YBa$_2$Cu$_3$O$_{6.5}$ (Ortho-II) Single
  Crystals

abstract:
  The polarized Raman scattering spectra from freshly cleaved $ab$, $ac$, and
$bc$ surfaces of high quality twin free YBa$_2$Cu$_3$O$_{6.5}$ (Ortho-II)
single crystals ($T_c$=57.5 K and $\Delta T = 0.6$ K) were studied between 80
and 300 K. All eleven $A_g$ Raman modes expected for the Ortho-II structure as
well some modes of $B_{2g}$ and $B_{3g}$ symmetry were identified in close
comparison with predictions of lattice dynamical calculations. The electronic
scattering from the $ab$ planes is strongly anisotropic and decreases between
200 and 100 K within the temperature range of previously reported pseudogap
opening. The coupling of phonons to Raman active electronic excitations
manifested by asymmetric (Fano) profiles of several modes also decreases in the
same range. Among the new findings that distinguish the Raman scattering of
Ortho-II from that of Ortho-I phase is the unusual relationship ($\alpha_{xx}
\approx -\alpha_{yy}$) between the elements of the Raman tensor of the apex
oxygen $A_g$ mode.


title:
Molecular jets driven by high-mass protostars: a detailed study of the
  IRAS 20126+4104 jet

abstract:
  We present here an extensive analysis of the protostellar jet driven by IRAS
20126+4104, deriving the kinematical, dynamical, and physical conditions of the
H2 gas along the flow. The jet has been investigated by means of near-IR H2 and
[FeII] narrow-band imaging, high resolution spectroscopy of the 1-0S(1) line
(2.12 um), NIR (0.9-2.5 um) low resolution spectroscopy, along with ISO-SWS and
LWS spectra (from 2.4 to 200 um). The flow shows a complex morphology. In
addition to the large-scale jet precession presented in previous studies, we
detect a small-scale wiggling close to the source, that may indicate the
presence of a multiple system. The peak radial velocities of the H2 knots range
from -42 to -14 km s^-1 in the blue lobe, and from -8 to 47 km s^-1 in the red
lobe. The low resolution spectra are rich in H_2 emission, and relatively faint
[FeII] (NIR), [OI] and [CII] (FIR) emission is observed in the region close to
the source. A warm H2 gas component has an average excitation temperature that
ranges between 2000 K and 2500 K. Additionally, the ISO-SWS spectrum reveals
the presence of a cold component (520 K), that strongly contributes to the
radiative cooling of the flow and plays a major role in the dynamics of the
flow. The estimated L(H2) of the jet is 8.2+/-0.7 L_sun, suggesting that
IRAS20126+4104 has an accretion rate significantly increased compared to
low-mass YSOs. This is also supported by the derived mass flux rate from the H2
lines (Mflux(H2)~7.5x10^-4 M_sun yr^-1). The comparison between the H2 and the
outflow parameters strongly indicates that the jet is driving, at least
partially, the outflow. As already found for low-mass protostellar jets, the
measured H2 outflow luminosity is tightly related to the source bolometric
luminosity.


title:
Bias-driven large power microwave emission from MgO-based tunnel
  magnetoresistance devices

abstract:
  Spin-momentum transfer between a spin-polarized current and a ferromagnetic
layer can induce steady-state magnetization precession, and has recently been
proposed as a working principle for ubiquitous radio-frequency devices for
radar and telecommunication applications. However, to-date, the development of
industrially attractive prototypes has been hampered by the inability to
identify systems which can provide enough power. Here, we demonstrate that
microwave signals with device-compatible output power levels can be generated
from a single magnetic tunnel junction with a lateral size of 100 nm, seven
orders of magnitude smaller than conventional radio-frequency oscillators. We
find that in MgO magnetic tunnel junctions the perpendicular torque induced by
the spin-polarized current on the local magnetization can reach 25% of the
in-plane spin-torque term, while exhibiting a different bias-dependence. Both
findings contrast with the results obtained on all-metallic structures -
previously investigated -, reflecting the fundamentally different transport
mechanisms in the two types of structures.


title: Shock-related radio emission during coronal mass ejection lift-off?

abstract:
  Aims: We identify the source of fast-drifting decimetric-metric radio
emission that is sometimes observed prior to the so-called flare continuum
emission. Fast-drift structures and continuum bursts are also observed in
association with coronal mass ejections (CMEs), not only flares. Methods: We
analyse radio spectral features and images acquired at radio, H-alpha, EUV, and
soft X-ray wavelengths, during an event close to the solar limb on 2 June 2003.
Results: The fast-drifting decimetric-metric radio burst corresponds to a
moving, wide emission front in the radio images, which is normally interpreted
as a signature of a propagating shock wave. A decimetric-metric type II burst
where only the second harmonic lane is visible could explain the observations.
After long-lasting activity in the active region, the hot and dense loops could
be absorbing or suppressing emission at the fundamental plasma frequency. The
observed burst speed suggests a super-Alfvenic velocity for the burst driver.
The expanding and opening loops, associated with the flare and the early phase
of CME lift-off, could be driving the shock. Alternatively, an instantaneous
but fast loop expansion could initiate a freely propagating shock wave. The
later, complex-looking decametre-hectometre wave type III bursts indicate the
existence of a propagating shock, although no interplanetary type II burst was
observed during the event. The data does not support CME bow shock or a shock
at the flanks of the CME as the origin of the fast-drift decimetric-metric
radio source. Therefore super-Alfvenic loop expansion is the best candidate for
the initiation of the shock wave, and this result challenges the current view
of metric/coronal shocks originating either in the flanks of CMEs or from flare
blast waves.


title:
Noise correlation spectroscopy of the broken order of a Mott insulating
  phase

abstract:
  We use a two-color lattice to break the homogeneous site occupation of an
atomic Mott Insulator of bosonic 87Rb. We detect the disruption of the ordered
Mott domains via noise correlation analysis of the atomic density distribution
after time-of-flight. The appearance of additional correlation peaks evidences
the redistribution of the atoms into a strongly inhomogeneous insulating state,
in quantitative agreement with the predictions.


title:
Magnetic states and spin-glass properties in Bi0.67Ca0.33MnO3:
  macroscopic ac measurements and neutron scattering

abstract:
  We report on the magnetic properties of the manganite Bi_{1-x}Ca_{x}MnO_3
(x=0.33) at low temperature. The analysis of the field expansion of the ac
susceptibility and the observation of aging properties make clear that a spin
glass phase appears below T = 39K, in the presence of magnetic order. Neutron
scattering shows both magnetic Bragg scattering and magnetic diffusion at small
angles, and confirms this coexistence. In contrast to Pr_{1-x}Ca_{x}MnO_3
(x=0.3-0.33) which exhibits a mesoscopic phase separation responsible for a
field driven percolation, the glassy and short range ferromagnetic order
observed here does not cause colossal magnetoresistance (CMR).


title:
Free-Space Imaging Beyond the Diffraction Limit Using a Veselago-Pendry
  Transmission-Line Superlens

abstract:
  Focusing using conventional lenses relies on the collection and interference
of propagating waves, but discounts the evanescent waves that decay rapidly
from the source. Since these evanescent waves contain the finest details of the
source, the image suffers a loss of resolution and is referred to as
'diffraction-limited'. Superlensing is the ability to create an image with fine
features beyond the diffraction limit, and can be achieved with a
'Veselago-Pendry' lens made from a metamaterial. Such a Veselago-Pendry
superlens for imaging in free space must be stringently designed to restore
both propagating and evanescent waves, but meeting these design conditions
(isotropic n = epsilon_r = mu_r = -1) has proven difficult and has made its
realization elusive. We demonstrate free-space imaging with a resolution over
three times better than the diffraction limit at microwave frequencies using a
Veselago-Pendry metamaterial superlens based on the negative-refractive-index
transmission-line (NRI-TL) approach, which affords precise control over its
electromagnetic properties and is also less susceptible to losses than other
approaches. A microwave superlens can be particularly useful for illumination
and discrimination of closely spaced buried objects over practical distances by
way of back-scattering, e.g. in tumour or landmine detection, or for targeted
irradiation/hyperthermia.


title:
A hyperboloidal study of tail decay rates for scalar and Yang-Mills
  fields

abstract:
  We investigate the asymptotic behavior of spherically symmetric solutions to
scalar wave and Yang-Mills equations on a Schwarzschild background. The studies
demonstrate the astrophysical relevance of null infinity in predicting
radiation signals for gravitational wave detectors and show how test fields on
unbounded domains in black hole spacetimes can be simulated conveniently by
numerically solving hyperboloidal initial value problems.


title: The Thermodynamics of Kaluza-Klein Black Hole/Bubble Chains

abstract:
  A Killing bubble is a minimal surface that arises as the fixed surface of a
spacelike Killing field. We compute the bubble contributions to the Smarr
relations and the mass and tension first laws for spacetimes containing both
black holes and Killing bubbles. The resulting relations display an interesting
interchange symmetry between the properties of black hole horizons and those of
KK bubbles. This interchange symmetry reflects the underlying relation between
static bubbles and black holes under double analytic continuation of the time
and Kaluza-Klein directions. The thermodynamics of bubbles involve a
geometrical quantity that we call the bubble surface gravity, which we show has
several properties in common with the black hole surface gravity.


title: Oscillations of MHD shock waves on the surfaces of T Tauri stars

abstract:
  This work treats the matter deceleration in a magnetohydrodynamics radiative
shock wave at the surface of a star. The problem is relevant to classical T
Tauri stars where infalling matter is channeled along the star's magnetic field
and stopped in the dense layers of photosphere. A significant new aspect of the
present work is that the magnetic field has an arbitrary angle with respect to
the normal to the star's surface. We consider the limit where the magnetic
field at the surface of the star is not very strong in the sense that the
inflow is super Alfv\'enic. In this limit the initial deceleration and heating
of plasma (at the entrance to the cooling zone) occurs in a fast
magnetohydrodynamic shock wave. To calculate the intensity of radiative losses
we use "real" and "power-law" radiative functions. We determine the
stability/instability of the radiative shock wave as a function of parameters
of the incoming flow: velocity, strength of the magnetic field, and its
inclination to the surface of the star. In a number of simulation runs with the
"real" radiative function, we find a simple criterion for stability of the
radiative shock wave. For a wide range of parameters, the periods of
oscillation of the shock wave are of the order 0.02-0.2 sec.


title: Solid state quantum memory using the 31P nuclear spin

abstract:
  The transfer of information between different physical forms is a central
theme in communication and computation, for example between processing entities
and memory. Nowhere is this more crucial than in quantum computation, where
great effort must be taken to protect the integrity of a fragile quantum bit.
Nuclear spins are known to benefit from long coherence times compared to
electron spins, but are slow to manipulate and suffer from weak thermal
polarisation. A powerful model for quantum computation is thus one in which
electron spins are used for processing and readout while nuclear spins are used
for storage. Here we demonstrate the coherent transfer of a superposition state
in an electron spin 'processing' qubit to a nuclear spin 'memory' qubit, using
a combination of microwave and radiofrequency pulses applied to 31P donors in
an isotopically pure 28Si crystal. The electron spin state can be stored in the
nuclear spin on a timescale that is long compared with the electron decoherence
time and then coherently transferred back to the electron spin, thus
demonstrating the 31P nuclear spin as a solid-state quantum memory. The overall
store/readout fidelity is about 90%, attributed to systematic imperfections in
radiofrequency pulses which can be improved through the use of composite
pulses. We apply dynamic decoupling to protect the nuclear spin quantum memory
element from sources of decoherence. The coherence lifetime of the quantum
memory element is found to exceed one second at 5.5K.


title: Quantum Illumination

abstract:
  The use of entangled light to illuminate objects is shown to provide
significant enhancements over unentangled light for detecting and imaging those
objects in the presence of high levels of noise and loss. Each signal sent out
is entangled with an ancilla, which is retained. Detection takes place via an
entangling measurement on the returning signal together with the ancilla.
Quantum illumination with e bits of entanglement increases the effective
signal-to-noise ratio of detection and imaging by a factor of 2^e, an
exponential improvement over unentangled illumination.


title: A New H I Survey of Active Galaxies

abstract:
  We have conducted a new Arecibo survey for H I emission for 113 galaxies with
broad-line (type 1) active galactic nuclei (AGNs) out to recession velocities
as high as 35,000 km/s. The primary aim of the study is to obtain sensitive H I
spectra for a well-defined, uniformly selected sample of active galaxies that
have estimates of their black hole masses in order to investigate correlations
between H I properties and the characteristics of the AGNs. H I emission was
detected in 66 out of the 101 (65%) objects with spectra uncorrupted by radio
frequency interference, among which 45 (68%) have line profiles with adequate
signal-to-noise ratio and sufficiently reliable inclination corrections to
yield robust deprojected rotational velocities. This paper presents the basic
survey products, including an atlas of H I spectra, measurements of H I flux,
line width, profile asymmetry, optical images, optical spectroscopic
parameters, as well as a summary of a number of derived properties pertaining
to the host galaxies. To enlarge our primary sample, we also assemble all
previously published H I measurements of type 1 AGNs for which can can estimate
black hole masses, which total an additional 53 objects. The final
comprehensive compilation of 154 broad-line active galaxies, by far the largest
sample ever studied, forms the basis of our companion paper, which uses the H I
database to explore a number of properties of the AGN host galaxies.


title: Magnetic Boron Nitride Nanoribbons with Tunable Electronic Properties

abstract:
  We present theoretical evidence, based on total-energy first-principles
calculations, of the existence of spin-polarized states well localized at and
extended along the edges of bare zigzag boron nitride nanoribbons. Our
calculations predict that all the magnetic configurations studied in this work
are thermally accessible at room temperature and present an energy gap. In
particular, we show that the high spin state, with a magnetic moment of 1
$\mu_B$ at each edge atom, presents a rich spectrum of electronic behaviors as
it can be controlled by applying an external electric field in order to obtain
metallic $\leftrightarrow$ semiconducting $\leftrightarrow$ half-metallic
transitions.


title: Transfer in multi-theme opinion dynamics of Deffuant et al

abstract:
  Monte Carlo simulations mix the opinion dynamics of Deffuant et al with the
cultural transfer model of Axelrod, using ten discrete possible opinions on ten
different themes. As Jacobmeier's simulations of the pure Deffuant case, people
preferably agree on nearly all or nearly no theme.


title: Geometry of obstructed equisingular families of projective hypersurfaces

abstract:
  We study geometric properties of certain obstructed equisingular families of
projective hypersurfaces with emphasis on smoothness, reducibility, being
reduced, and having expected dimension.
  In the case of minimal obstructness, we give a detailed description of such
families corresponding to quasihomogeneous singularities.
  Next we study the behavior of these properties with respect to stable
equivalence of singularities. We show that under certain conditions,
stabilization of singularities ensures the existence of a reduced component of
expected dimension. For minimally obstructed families the whole family becomes
irreducible.
  As an application we show that if the equisingular family of a projective
hypersurface H has a reduced component of expected dimension then the
deformation of H induced by the linear system |H| is complete with respect to
one-parameter deformations.


title: Excelsior: Bringing the Benefits of Modularisation to Excel

abstract:
  Excel lacks features for modular design. Had it such features, as do most
programming languages, they would save time, avoid unneeded programming, make
mistakes less likely, make code-control easier, help organisations adopt a
uniform house style, and open business opportunities in buying and selling
spreadsheet modules. I present Excelsior, a system for bringing these benefits
to Excel.


title:
Reaction of electron-positron to omega and pi mesons and rho(1450) and
  rho(1700) mesons in quark model

abstract:
  The investigation in the work of the reaction electron-positron to omega and
pi0 mesons in the 3P0 nonrelativistic quark model reveals that the reaction
electron-positron to omega and pi0 mesons process at the energy region from the
omega and pi mesons threshold to 2.0 GeV is dominated by the two-step process
in which the primary quark-antiquark pair first forms rho and rho' mesons and
then the vector mesons decay into omega and pi. With rho(1450) and rho(1700)
mainly in 2S and 1D states respectively, the experimental data for the cross
section of the reaction electron-positron to omega and pi0 mesons are well
produced in the 3P0 quark model. The work supports the argument that rho(1450)
is mainly a 2S meson and rho(1700) a 1D meson.


title:
The exoplanet-host star iota Horologii: an evaporated member of the
  primordial Hyades cluster

abstract:
  We show that the exoplanet-host star iota Horologii, alias HD17051, which
belongs to the so-called Hyades stream, was formed within the primordial Hyades
stellar cluster and has evaporated towards its present location, 40 pc away.
This result has been obtained unambiguously by studying the acoustic
oscillations of this star, using the HARPS spectrometer in La Silla Observatory
(ESO, Chili). Besides the fact that $\iota$ Hor belongs to the Hyades stream,
we give evidence that it has the same metallicity, helium abundance, and age as
the other stars of the Hyades cluster. They were formed together, at the same
time, in the same primordial cloud. This result has strong implications for
theories of stellar formation. It also indicates that the observed
overmetallicity of this exoplanet-host star, about twice that of the Sun, is
original and not caused by planet accretion during the formation of the
planetary system.


title: What Exactly is the Information Paradox?

abstract:
  The black hole information paradox tells us something important about the way
quantum mechanics and gravity fit together. In these lectures I try to give a
pedagogical review of the essential physics leading to the paradox, using
mostly pictures. Hawking's argument is recast as a `theorem': if quantum
gravity effects are confined to within a given length scale and the vacuum is
assumed to be unique, then there will be information loss. We conclude with a
brief summary of how quantum effects in string theory violate the first
condition and make the interior of the hole a `fuzzball'.


title: Integration of Holomorphic Lie Algebroids

abstract:
  We prove that a holomorphic Lie algebroid is integrable if, and only if, its
underlying real Lie algebroid is integrable. Thus the integrability criteria of
Crainic-Fernandes do also apply in the holomorphic context without any
modification. As a consequence we give another proof of the following theorem:
a holomorphic Poisson manifold is integrable if, and only if, its real (or
imaginary) part is integrable as a real Poisson manifold.


title: The environment of graphene probed by electrostatic force microscopy

abstract:
  We employ electrostatic force microscopy to study the electrostatic
environment of graphene sheets prepared with the micro-mechanical exfoliation
technique. We detect the electric dipole of residues left from the adhesive
tape during graphene preparation, as well as the dipole of water molecules
adsorbed on top of graphene. Water molecules form a dipole layer that can
generate an electric field as large as 10^9 V/m. We expect that water molecules
can significantly modify the electrical properties of graphene devices.


title:
A fundamental-measure density functional for mixtures of parallel hard
  cylinders

abstract:
  We obtain a fundamental measure density functional for mixtures of parallel
hard cylinders. To this purpose we first generalize to multicomponent mixtures
the fundamental measure functional proposed by Tarazona and Rosenfeld for a
one-component hard disk fluid, through a method alternative to the cavity
formalism of these authors. We show the equivalence of both methods when
applied to two-dimensional fluids. The density functional so obtained reduces
to the exact density functional for one-dimensional mixtures of hard rods when
applied to one-dimensional profiles. In a second step we apply an idea put
forward some time ago by two of us, based again on a dimensional reduction of
the system, and derive a density functional for mixtures of parallel hard
cylinders. We explore some features of this functional by determining the
fluid-fluid demixing spinodals for a binary mixture of cylinders with the same
volume, and by calculating the direct correlation functions.


title:
Applications of Automata and Graphs: Labeling-Operators in Hilbert Space
  I

abstract:
  We show that certain representations of graphs by operators on Hilbert space
have uses in signal processing and in symbolic dynamics. Our main result is
that graphs built on automata have fractal characteristics. We make this
precise with the use of Representation Theory and of Spectral Theory of a
certain family of Hecke operators. Let G be a directed graph. We begin by
building the graph groupoid G induced by G, and representations of G. Our main
application is to the groupoids defined from automata. By assigning weights to
the edges of a fixed graph G, we give conditions for G to acquire fractal-like
properties, and hence we can have fractaloids or G-fractals. Our standing
assumption on G is that it is locally finite and connected, and our labeling of
G is determined by the "out-degrees of vertices". From our labeling, we arrive
at a family of Hecke-type operators whose spectrum is computed. As
applications, we are able to build representations by operators on Hilbert
spaces (including the Hecke operators); and we further show that automata built
on a finite alphabet generate fractaloids. Our Hecke-type operators, or
labeling operators, come from an amalgamated free probability construction, and
we compute the corresponding amalgamated free moments. We show that the free
moments are completely determined by certain scalar-valued functions.


title: Fusion hierarchies for N = 4 superYang-Mills theory

abstract:
  We employ the analytic Bethe Anzats to construct eigenvalues of transfer
matrices with finite-dimensional atypical representations in the auxiliary
space for the putative long-range spin chain encoding anomalous dimensions of
all composite single-trace gauge invariant operators of the maximally
supersymmetric Yang-Mills theory. They obey an infinite fusion hierarchy which
can be reduced to a finite set of integral relations for a minimal set of
transfer matrices. This set is used to derive a finite systems of functional
equations for eigenvalues of nested Baxter polynomials.


title: Time desynchronization and Ehrenfest paradox

abstract:
  One of the kinematical effects that give raise to the principle of relativity
is time desynchronization of moving clocks. The detailed analysis of this
phenomenon is of great importance for leading us to the right (and new)
solution of Ehrenfest paradox.


title:
Optimal spatial transportation networks where link-costs are sublinear
  in link-capacity

abstract:
  Consider designing a transportation network on $n$ vertices in the plane,
with traffic demand uniform over all source-destination pairs. Suppose the cost
of a link of length $\ell$ and capacity $c$ scales as $\ell c^\beta$ for fixed
$0<\beta<1$. Under appropriate standardization, the cost of the minimum cost
Gilbert network grows essentially as $n^{\alpha(\beta)}$, where $\alpha(\beta)
= 1 - \frac{\beta}{2}$ on $0 < \beta \leq {1/2}$ and $\alpha(\beta) = {1/2} +
\frac{\beta}{2}$ on ${1/2} \leq \beta < 1$. This quantity is an upper bound in
the worst case (of vertex positions), and a lower bound under mild regularity
assumptions. Essentially the same bounds hold if we constrain the network to be
efficient in the sense that average route-length is only $1 + o(1)$ times
average straight line length. The transition at $\beta = {1/2}$ corresponds to
the dominant cost contribution changing from short links to long links. The
upper bounds arise in the following type of hierarchical networks, which are
therefore optimal in an order of magnitude sense. On the large scale, use a
sparse Poisson line process to provide long-range links. On the medium scale,
use hierachical routing on the square lattice. On the small scale, link
vertices directly to medium-grid points. We discuss one of many possible
variant models, in which links also have a designed maximum speed $s$ and the
cost becomes $\ell c^\beta s^\gamma$.


title:
Electronic properties of disordered valence-bond stripes in cuprate
  superconductors

abstract:
  We calculate electronic single-particle properties of short-range ordered
stripe states, using Monte-Carlo simulations of collective charge-density wave
(CDW) order parameters coupled to fermions on a 2d square lattice. For
superconducting bond-centered stripes with a d-wave form factor, we find a
valence-bond "glass" which coexists with low-energy quasiparticles featuring
interference phenomena, in agreement with recent scanning-tunneling-microscopy
(STM) measurements on underdoped BSCCO and CaNaCuOCl. Together with earlier
work, our calculations provide a link between CDW features seen in STM and
those in magnetic neutron scattering.


title:
Lepton flavour violating semileptonic tau decays in constrained
  MSSM-seesaw scenarios

abstract:
  In this work we study the Lepton Flavour Violating semileptonic $\tau$
decays: 1) $\tau \to \mu PP$ with $PP= \pi^+\pi^-, \pi^0\pi^0, K^+K^-, K^0
{\bar K}^0$; 2) $\tau \to \mu P$ with $P=\pi^0, \eta, \eta'$ and 3) $\tau \to
\mu V$ with $V = \rho^0, \phi$. We work within the context of two constrained
MSSM scenarios: the CMSSM and NUHM. A full one-(SUSY)loop computation is
presented and the importance of the various contributions, the $\gamma$-, $Z$-,
and Higgs bosons mediated ones are analysed. The hadronization of quark
bilinears is performed within the chiral framework. Some discrepancies in the
predicted rates for BR($\tau \to \mu \eta$), BR($\tau \to \mu \eta'$) and
BR($\tau \to \mu K^+K^-$) are found with respect to previous estimates, which
will be commented here. These three channels will be shown to be the most
competitive ones to test simultaneously the Lepton Flavour Violation and the
Higgs sector. We further present here a set of approximate formulas for all the
semileptonic channels which we believe can be useful for further comparison
with present and future data.


title: Standard Model couplings and collider signatures of a light scalar

abstract:
  The electroweak symmetry breaking (EWSB) sector of the Standard Model can be
far richer and more interesting than the usual single scalar doublet model. We
explore scenarios where the EWSB sector is nearly scale invariant and
consequently gives rise to a light CP even scalar particle. The one-doublet SM
is in that category, as are many other models with either weakly or strongly
coupled sectors that trigger EWSB. We study the couplings of the light scalar
to the SM particles that can arise from the explicit breaking of scale
invariance focusing on the possible differences with the minimal SM. The
couplings of the light scalar to light fermions, as well as to the massless
gauge bosons, can be significantly enhanced. We find possible new discovery
channels due to the decays of the conformal scalar into e^+e^- and mu^+mu^-
pairs as well as new production channels via light quark annihilation.


title: Instantons and Toric Quiver Gauge Theories

abstract:
  We show how to construct the general action coupling (multi)instantons to
gauge theories arising from branes probing arbitrary toric singularities. We
give a general set of rules for how to construct such an action given the
knowledge of the superpotential for the gauge theory. The main idea is to
obtain the action by higgsing a theory whose instanton dynamics is known,
namely an orbifold of N=4 super Yang-Mills. We find that the couplings of the
fermionic zero-modes with the holomorphic fields are dictated by the structure
of the superpotential describing the toric singularity. We present explicit
examples such as the Suspended Pinch Point, the Conifold and the first three
del Pezzo's. We perform various checks on these results by further higgsing to
smaller orbifolds and present some applications, including both gauge theory
and stringy instantons.


title:
Constraints on the Emission and Viewing Geometry of the Transient
  Anomalous X-ray Pulsar XTE J1810-197

abstract:
  The temporal decay of the flux components of Transient Anomalous X-ray Pulsar
XTE J1810-197 following its 2002 outburst presents a unique opportunity to
probe the emission geometry of a magnetar. Toward this goal, we model the
magnitude of the pulsar's modulation in narrow spectral bands over time.
Following previous work, we assume that the post-outburst flux is produced in
two distinct thermal components arising from a hot spot and a warm concentric
ring. We include general relativistic effects on the blackbody spectra due to
gravitational redshift and light bending near the stellar surface, which
strongly depend on radius. This affects the model fits for the temperature and
size of the emission regions. For the hot spot, the observed temporal and
energy-dependent pulse modulation is found to require an anisotropic,
pencil-beamed radiation pattern. We are able to constrain an allowed range for
the angles that the line-of-sight (psi) and the hot spot pole (xi) make with
respect to the spin-axis. Within errors, this is defined by the locus of points
in the xi-psi plane that lie along the line (xi+beta(R))(psi+beta(R)) ~
constant, where beta(R) is a function of the radius R of the star. For a
canonical value of R=12 km, the viewing parameters range from psi=xi=37 deg to
(psi,xi)=(85 deg,15 deg). We discuss our results in the context of magnetar
emission models.


title: Diffusion at the random matrix hard edge

abstract:
  We show that the limiting minimal eigenvalue distributions for a natural
generalization of Gaussian sample-covariance structures (the "beta ensembles")
are described by the spectrum of a random diffusion generator. By a Riccati
transformation, we obtain a second diffusion description of the limiting
eigenvalues in terms of hitting laws. This picture pertains to the so-called
hard edge of random matrix theory and sits in complement to the recent work of
the authors and B. Virag on the general beta random matrix soft edge. In fact,
the diffusion descriptions found on both sides are used here to prove there
exists a transition between the soft and hard edge laws at all values of beta.


title: The Disk Around CoKu Tau/4: Circumbinary, not Transitional

abstract:
  CoKu Tau/4 has been labeled as one of the very few known transition disk
objects: disks around young stars that have their inner disks cleared of dust,
arguably due to planetary formation. We report aperture-masking interferometry
and adaptive optics imaging observations showing that CoKu Tau/4 is in fact a
near-equal binary star of projected separation $\sim$53 mas ($\sim$8 AU). The
spectral energy distribution of the disk is then naturally explained by inner
truncation of the disk through gravitational interactions with the binary star
system. We discuss the possibility that such ``unseen'' binary companions could
cause other circumbinary disks to be labeled as transitional.


title: Phases Of N=2 Theories In 1+1 Dimensions With Boundary

abstract:
  We study B-type D-branes in linear sigma models with Abelian gauge groups.
The most important finding is the grade restriction rule. It classifies
representations of the gauge group on the Chan-Paton factor, which can be used
to define a family of D-branes over a region of the K\"ahler moduli space that
connects special points of different character. As an application, we find a
precise, transparent relation between D-branes in various geometric phases as
well as free orbifold and Landau-Ginzburg points. The result reproduces and
unifies many of the earlier mathematical results on equivalences of D-brane
categories, including the McKay correspondence and Orlov's construction.


title: Recollision-Induced Plasmon Excitation in Strong Laser Fields

abstract:
  Recolliding electrons are responsible for many of the interesting phenomena
observed in the interaction of strong laser fields with atoms and molecules. We
show that in multielectron targets such as C60 a new important recollision
pathway opens up: the returning electron may excite collective modes even if
the laser frequency is far off-resonant. We formulate a simple analytical
theory which predicts that the recollision-induced excitation of collective
modes should dominate over the "usual" harmonic generation yield at 800nm
wavelength. In this case the tomographic imaging of complex multielectron
systems may be obscured. We employ a time-dependent density functional model of
C60 and show that with increasing laser wavelength the dynamics becomes more
and more single active electron-like, suggesting that long wavelengths are to
be preferred for imaging purposes.


title: Modular Classes of Loday Algebroids

abstract:
  We introduce the concept of Loday algebroids, a generalization of Courant
algebroids. We define the naive cohomology and modular class of a Loday
algebroid, and we show that the modular class of the double of a Lie
bialgebroid vanishes. For Courant algebroids, we describe the relation between
the naive and standard cohomologies and we conjecture that they are isomorphic
when the Courant algebroid is transitive.


title: The Kuranishi-space of complex parallelisable nilmanifolds

abstract:
  We show that the deformation space of complex parallelisable nilmanifolds can
be described by polynomial equations but is almost never smooth. This is
remarkable since these manifolds have trivial canonical bundle and are
holomorphic symplectic in even dimension. We describe the Kuranishi space in
detail in several examples and also analyse when small deformations remain
complex parallelisable


title: Electronic transport in inhomogeneous quantum wires

abstract:
  We study the transport properties of a long non-uniform quantum wire where
the electron-electron interactions and the density vary smoothly at large
length scales. We show that these inhomogeneities lead to a finite resistivity
of the wire, due to a weak violation of momentum conservation in the collisions
between electrons. Estimating the rate of change of momentum associated with
non-momentum-conserving scattering processes, we derive the expression for the
resistivity of the wire in the regime of weakly interacting electrons and find
a contribution linear in temperature for a broad range of temperatures below
the Fermi energy. By estimating the energy dissipated throughout the wire by
low-energy excitations, we then develop a different method for deriving the
resistivity of the wire, which can be combined with the bosonization formalism.
This allows us to compare our results with previous works relying on an
extension of the Tomonaga-Luttinger model to inhomogeneous systems.


title: Testing neutrino flavor mixing plus decay with neutrino telescopes

abstract:
  We discuss the interplay of neutrino oscillation and decay properties at
neutrino telescopes. Motivated by recent unparticle scenarios, which open the
possibility of new neutrino decay modes over astrophysical distances, we
perform a complete classification of possible decay schemes, and we illustrate
how different scenarios can be identified. Moreover, we show that the
sensitivity of neutrino telescopes to standard neutrino properties, such as the
mass hierarchy or delta_CP, is greatly enhanced in specific decay scenarios. In
particular we discuss the impact of an astrophysical neutrino detection on
terrestrial experiments, such as on the mass hierarchy measurement at NOvA. For
example, we find that the scenario where only nu_1 is stable can be uniquely
identified against all the other decay schemes, and that in this case CP
violation can be established (for large theta_13) by the combination of Double
Chooz with the track-to-shower ratio at a neutrino telescope, even if the
flavor composition at the source is unknown. Our statements are based on a
complete analysis of all the present solar, atmospheric, reactor and
accelerator neutrino data, as well as on realistic simulation of future
terrestrial neutrino oscillation experiments.


title:
Structural and compositional properties of brown dwarf disks: the case
  of 2MASS J04442713+2512164

abstract:
  In order to improve our understanding of substellar formation, we have
performed a compositional and structural study of a brown dwarf disk.
  We present the result of photometric, spectroscopic and imaging observations
of 2MASS J04442713+2512164, a young brown dwarf (M7.25) member of the Taurus
association. Our dataset, combined with results from the literature, provides a
complete coverage of the spectral energy distribution from the optical to the
millimeter including the first photometric measurement of a brown dwarf disk at
3.7mm, and allows us to perform a detailed analysis of the disk properties.
  The target was known to have a disk. High resolution optical spectroscopy
shows that it is intensely accreting, and powers a jet and an outflow. The disk
structure is similar to that observed for more massive TTauri stars. Spectral
decomposition models of Spitzer/IRS spectra suggest that the mid-infrared
emission from the optically thin disk layers is dominated by grains with
intermediate sizes (1.5micron). Crystalline silicates are significantly more
abondant in the outer part and/or deeper layers of the disk, implying very
efficient mixing and/or additional annealing processes. Sub-millimeter and
millimeter data indicate that most of the disk mass is in large grains (>1mm)


title: Two-cover descent on hyperelliptic curves

abstract:
  We describe an algorithm that determines a set of unramified covers of a
given hyperelliptic curve, with the property that any rational point will lift
to one of the covers. In particular, if the algorithm returns an empty set,
then the hyperelliptic curve has no rational points. This provides a relatively
efficiently tested criterion for solvability of hyperelliptic curves. We also
discuss applications of this algorithm to curves of genus 1 and to curves with
rational points.


title: Radial and Nonradial Oscillation Modes in Rapidly Rotating Stars

abstract:
  Radial and nonradial oscillations offer the opportunity to investigate the
interior properties of stars. We use 2D stellar models and a 2D finite
difference integration of the linearized pulsation equations to calculate
non-radial oscillations. This approach allows us to directly calculate the
pulsation modes for a distorted rotating star without treating the rotation as
a perturbation. We are also able to express the finite difference solution in
the horizontal direction as a sum of multiple spherical harmonics for any given
mode. Using these methods, we have investigated the effects of increasing
rotation and the number of spherical harmonics on the calculated
eigenfrequencies and eigenfunctions and compared the results to perturbation
theory. In slowly rotating stars, current methods work well, and we show that
the eigenfunction can be accurately modelled using 2nd order perturbation
theory and a single spherical harmonic. We use 10 Msun models with velocities
ranging from 0 to 420 km/s (0.89 Omega_c) and examine low order p modes. We
find that one spherical harmonic remains reasonable up to a rotation rate
around 300km s^{-1} (0.69 Omega_c) for the radial fundamental mode, but can
fail at rotation rates as low as 90 km/s (0.23 Omega_c) for the 2H mode or l =
2 p_2 mode, based on the eigenfrequencies alone. Depending on the mode in
question, a single spherical harmonic may fail at lower rotation rates if the
shape of the eigenfunction is taken into consideration. Perturbation theory, in
contrast, remains valid up to relatively high rotation rates for most modes. We
find the lowest failure surface equatorial velocity is 120 km/s (0.30 Omega_c)
for the l = 2 p_2 mode, but failure velocities between 240 and 300 km/s
(0.58-0.69 Omega_c)are more typical.


title: The missing angular momentum of superconductors

abstract:
  We point out that the Meissner effect, the process by which a superconductor
expels magnetic field from its interior, represents an unsolved puzzle within
the London-BCS theoretical framework used to describe the physics of
conventional superconductors, because it appears to give rise to
non-conservation of angular momentum. Possible ways to avoid this inconsistency
within the conventional theory of superconductivity are argued to be
farfetched. Consequently, we argue that unless/until a consistent explanation
is put forth, the existence of the Meissner effect represents an anomaly that
casts doubt on the validity of the conventional framework. Instead, we point
out that two elements of the unconventional theory of hole superconductivity,
namely that the charge distribution in superconductors is macroscopically
inhomogeneous, and the fact that spin-orbit coupling plays an essential role,
allow for a consistent explanation of the Meissner effect.


title:
Quark-hadron duality and truncated moments of nucleon structure
  functions

abstract:
  We employ a novel new approach to study local quark-hadron duality using
"truncated" moments, or integrals of structure functions over restricted
regions of x, to determine the degree to which individual resonance regions are
dominated by leading twist. Because truncated moments obey the same Q^2
evolution equations as the leading twist parton distributions, this approach
makes possible for the first time a description of resonance region data and
the phenomenon of quark-hadron duality directly from QCD.


title: On the energy of inviscid singular flows

abstract:
  It is known that the energy of a weak solution to the Euler equation is
conserved if it is slightly more regular than the Besov space
$B^{1/3}_{3,\infty}$. When the singular set of the solution is (or belongs to)
a smooth manifold, we derive various $L^p$-space regularity criteria
dimensionally equivalent to the critical one. In particular, if the singular
set is a hypersurface the energy of $u$ is conserved provided the one sided
non-tangential limits to the surface exist and the non-tangential maximal
function is $L^3$ integrable, while the maximal function of the pressure is
$L^{3/2}$ integrable. The results directly apply to prove energy conservation
of the classical vortex sheets in both 2D and 3D at least in those cases where
the energy is finite.


title:
A geometric condition implying energy equality for solutions of 3D
  Navier-Stokes equation

abstract:
  We prove that every weak solution $u$ to the 3D Navier-Stokes equation that
belongs to the class $L^3L^{9/2}$ and $\n u$ belongs to $L^3L^{9/5}$ localy
away from a 1/2-H\"{o}lder continuous curve in time satisfies the generalized
energy equality. In particular every such solution is suitable.


title: Schwarz Lemma for the tetrablock

abstract:
  We describe all complex geodesics in the tetrablock passing through the
origin thus obtaining the form of all extremals in the Schwarz Lemma for the
tetrablock. Some other extremals for the Lempert function and geodesics are
also given. The paper may be seen as a continuation of the results Abouhajar,
White and Young. The proofs rely on a necessary form of complex geodesics in
general domains which is also proven in the paper.


title:
On the degeneracy between primordial tensor modes and cosmic strings in
  future CMB data from Planck

abstract:
  While observations indicate that the predominant source of cosmic
inhomogeneities are adiabatic perturbations, there are a variety of candidates
to provide auxiliary trace effects, including inflation-generated primordial
tensors and cosmic defects which both produce B-mode cosmic microwave
background (CMB) polarization. We investigate whether future experiments may
suffer confusion as to the true origin of such effects, focusing on the ability
of Planck to distinguish tensors from cosmic strings, and show that there is no
significant degeneracy.


title: Compactly supported analytic indices for Lie groupoids

abstract:
  For any Lie groupoid we construct an analytic index morphism taking values in
a modified $K-theory$ group which involves the convolution algebra of compactly
supported smooth functions over the groupoid. The construction is performed by
using the deformation algebra of smooth functions over the tangent groupoid
constructed in \cite{Ca2}. This allows in particular to prove a more primitive
version of the Connes-Skandalis Longitudinal index Theorem for foliations, that
is, an index theorem taking values in a group which pairs with Cyclic cocycles.
As other application, for $D$ a $\gr-$PDO elliptic operator with associated
index $ind D\in K_0(\ci_c (\gr))$, we prove that the pairing $$<ind D,\tau>,$$
with $\tau$ a bounded continuous cyclic cocycle, only depends on the principal
symbol class $[\sigma(D)]\in K^0(A^*\gr)$. The result is completely general for
{\'E}tale groupoids. We discuss some potential applications to the Novikov's
conjecture.


title: Time dilation and Langevin paradox

abstract:
  The principle of invariance of the velocity of light is only valid for the
wrong measurements of inertial observers who ignore their own movement and
consider themselves at rest. The Langevin (or clock) paradox arises when it is
assumed that the real velocity (and not only the wrong measured velocity) of
light in free space can be the same for different observers. Nevertheless, it
is generally assumed as true such incoherent assumption that leads to the
paradox. To clarify the issue is of great interest to analyse the physics
underlying the phenomenon of time dilation (which is not only the result of a
mathematical formula) and this has been done in this work. The exact value of
light dragging coefficient is also derived.


title:
Actions of automorphism groups of free groups on homology spheres and
  acyclic manifolds

abstract:
  For n at least 3, let SAut(F_n) denote the unique subgroup of index two in
the automorphism group of a free group. The standard linear action of SL(n,Z)
on R^n induces non-trivial actions of SAut(F_n) on R^n and on S^{n-1}. We prove
that SAut(F_n) admits no non-trivial actions by homeomorphisms on acyclic
manifolds or spheres of smaller dimension. Indeed, SAut(F_n) cannot act
non-trivially on any generalized Z_2-homology sphere of dimension less than
n-1, nor on any Z_2-acyclic Z_2-homology manifold of dimension less than n. It
follows that SL(n,Z) cannot act non-trivially on such spaces either. When n is
even, we obtain similar results with Z_3 coefficients.