title:
A 2dF spectroscopic study of globular clusters in NGC 5128: Probing the
  formation history of the nearest giant Elliptical

abstract:
  We have performed a spectroscopic study of globular clusters (GCs) in the
giant elliptical NGC 5128 using the 2dF facility at the Anglo-Australian
telescope. We obtained integrated optical spectra for a total of 254 GCs, 79 of
which are newly confirmed on the basis of their radial velocities and spectra.
In addition, we obtained an integrated spectrum of the galaxy starlight along
the southern major axis. We derive an empirical metallicity distribution
function (MDF) for 207 GCs (~14 of the estimated total GC system) based upon
Milky Way GCs. This MDF is multimodal at high statistical significance with
peaks at [Z/H]~-1.3 and -0.5. A comparison between the GC MDF and that of the
stellar halo at 20 kpc (~4 Reff) reveals close coincidence at the metal-rich
ends of the distributions. However, an inner 8 kpc stellar MDF shows a clear
excess of metal-rich stars when compared to the GCs. We compare a higher S/N
subsample (147 GCs) with two stellar population models which include non-solar
abundance ratio corrections. The vast majority of our sample (~90%) appears
old, with ages similar to the Milky Way GC system. There is evidence for a
population of intermediate-age (~4-8 Gy) GCs (<15% of the sample) which are on
average more metal-rich than the old GCs. We also identify at least one younger
cluster (~1-2 Gy) in the central regions of the galaxy. Our observations are
consistent with a picture where NGC 5128 has undergone at least two mergers
and/or interactions involving star formation and limited GC formation since
z=1, however the effect of non-canonical hot stellar populations on the
integrated spectra of GCs remains an outstanding uncertainty in our GC age
estimates.


title:
Random motion with gamma-distributed alternating velocities in
  biological modeling

abstract:
  Motivated by applications in mathematical biology concerning randomly
alternating motion of micro-organisms, we analyze a generalized integrated
telegraph process. The random times between consecutive velocity reversals are
gamma-distributed, and perform an alternating renewal process. We obtain the
probability law and the mean of the process.


title:
A Rigorous Finite-Element Domain Decomposition Method for
  Electromagnetic Near Field Simulations

abstract:
  Rigorous computer simulations of propagating electromagnetic fields have
become an important tool for optical metrology and design of nanostructured
optical components. A vectorial finite element method (FEM) is a good choice
for an accurate modeling of complicated geometrical features. However, from a
numerical point of view solving the arising system of linear equations is very
demanding even for medium sized 3D domains. In numerics, a domain decomposition
method is a commonly used strategy to overcome this problem. Within this
approach the overall computational domain is split up into smaller domains and
interface conditions are used to assure continuity of the electromagnetic
field. Unfortunately, standard implementations of the domain decomposition
method as developed for electrostatic problems are not appropriate for wave
propagation problems. In an earlier paper we therefore proposed a domain
decomposition method adapted to electromagnetic field wave propagation
problems. In this paper we apply this method to 3D mask simulation.


title: Statistical Mechanics of Interacting Run-and-Tumble Bacteria

abstract:
  We consider self-propelled particles undergoing run-and-tumble dynamics (as
exhibited by E. coli) in one dimension. Building on previous analyses at
drift-diffusion level for the one-particle density, we add both interactions
and noise, enabling discussion of domain formation by "self-trapping", and
other collective phenomena. Mapping onto detailed-balance systems is possible
in certain cases.


title:
Kinetically driven helix formation during the homopolymer collapse
  process

abstract:
  Using Langevin simulations, we find that simple 'generic' bead-and-spring
homopolymer chains in a sufficiently bad solvent spontaneously develop helical
order during the process of collapsing from an initially stretched
conformation. The helix formation is initiated by the unstable modes of the
straight chain, which drive the system towards a long-lived metastable
transient state. The effect is most pronounced if hydrodynamic interactions are
screened.


title:
Quantum mechanical ab-initio simulation of the electron screening effect
  in metal deuteride crystals

abstract:
  In antecedent experiments the electron screening energies of the d+d
reactions in metallic environments have been determined to be enhanced by an
order of magnitude in comparison to the case of gaseous deuterium targets. The
analytical models describing averaged material properties have not been able to
explain the experimental results so far. Therefore, a first effort has been
undertaken to simulate the dynamics of reacting deuterons in a metallic lattice
by means of an ab-initio Hartree-Fock calculation of the total electrostatic
force between the lattice and the successively approaching deuterons via path
integration. The calculations have been performed for Li and Ta, clearly
showing a migration of electrons from host metallic to the deuterium atoms.
However, in order to avoid more of the necessary simplifications in the model
the utilization of a massive parallel supercomputer would be required.


title:
Spin-spin correlations of the spin-ladder compound
  (C$_5$H$_{12}$N)$_2$CuBr$_4$ measured by magnetostriction and comparison to
  Quantum Monte Carlo results

abstract:
  Magnetostriction and thermal expansion of the spin-ladder compound
piperidinium copper bromide (C$_5$H$_{12}$N)$_2$CuBr$_4$ are analyzed in
detail. We find perfect agreement between experiments and the theory of a
two-leg spin ladder Hamiltonian for more than a decade in temperature and in a
wide range of magnetic fields. Relating the magnetostriction along different
crystallographic directions to two static spin-spin correlation functions,
which we compute with Quantum Monte Carlo, allows us to reconstruct the
magnetoelastic couplings of (C$_5$H$_{12}$N)$_2$CuBr$_4$. We especially focus
on the quantum critical behavior near the two critical magnetic fields $H_{c1}$
and $H_{c2}$, which is characterized by strong singularities rooted in the low
dimensionality of the critical spin-system. Extending our discussion in Lorenz
et al [Phys. Rev. Lett., 100, 067208 (2008)], we show explicitly that the
thermal expansion near the upper critical field $H_{c2}$ is quantitatively
described by a parameter-free theory of one-dimensional, non-relativistic
Fermions. We also point out that there exists a singular quantum critical
correction to the elastic moduli. This correction is proportional to the
magnetic susceptibility $\chi$ which diverges as $\chi \sim 1/\sqrt{T}$ at the
critical fields and thus leads to a strong softening of the crystal.


title:
The $B(B_s)\to D_{(s)} P$, $D_{(s)} V$, $D_{(s)}^{*}P$ and
  $D_{(s)}^{*}V$ decays in the perturbative QCD approach

abstract:
  Two-body non-leptonic charmed decays $B_{(s)} \to D_{(s)}P$, $D_{(s)}^*P$,
$D_{(s)}V$ and $D_{(s)}^*V$ are analyzed in perturbative QCD approach, where
$P$ and $V$ denote the light pseudoscalar meson and vector meson, respectively.
We test the $D$ meson wave function by a $\chi^2$ fit with experimental data of
six $B\to DP$ channels. We give the branching ratios of all the charmed B decay
channels, most of which agree with experiments amazingly well. The predicted
$B_s$ decays can be confronted with the future experimental data. By
straightforward calculations, our pQCD approach gives the right relative strong
phase of $a_2/a_1$ with experiments. We also predict the percentage of
transverse polarizations in $B_{(s)} \to D^* V$ decay channels.


title: Scalar mesons and polarizability of the nucleon

abstract:
  It is shown that the scalar mesons $\sigma$, $f_0(980)$ and $a_0(980)$ as
$t$-channel exchanges quantitatively solve the problem of diamagnetism and give
an explanation of the large missing part of the electric polarizability
$\alpha$ showing up when only the pion cloud is taken into account. The
electric polarizability of the proton $\alpha_p$ confirms a two-photon width of
the $\sigma$ meson of $\Gamma_{\sigma\gamma\gamma}=(2.58\pm 0.26)$ keV.


title: Resonance distribution in open quantum chaotic systems

abstract:
  In order to study the resonance spectra of chaotic cavities subject to some
damping (which can be due to absorption or partial reflection at the
boundaries), we use a model of damped quantum maps. In the high-frequency
limit, the distribution of (quantum) decay rates is shown to cluster near a
``typical'' value, which is larger than the classical decay rate of the
corresponding damped ray dynamics. The speed of this clustering may be quite
slow, which could explain why it has not been detected in previous numerical
data.


title:
Faithful representations of minimal dimension of current Heisenberg Lie
  algebras

abstract:
  Given a Lie algebra $\mathfrak{g}$ over a field of characteristic zero $k$,
let $\mu(\mathfrak{g})=\min\{\dim \pi: \pi\text{is a faithful representation
of}\mathfrak{g}\}$. Let $\mathfrak{h}_{m}$ be the Heisenberg Lie algebra of
dimension $2m+1$ over $k$ and let $k[t]$ be the polynomial algebra in one
variable. Given $m\in\mathbb{N}$ and $p\in k[t]$, let
$\mathfrak{h}_{m,p}=\mathfrak{h}_m\otimes k[t]/(p)$ be the current Lie algebra
associated to $\mathfrak{h}_m$ and $k[t]/(p)$, where $(p)$ is the principal
ideal in $k[t]$ generated by $p$. In this paper we prove that $
mu(\mathfrak{h}_{m,p}) = m \deg p + \left \lceil 2\sqrt{\deg p} \right\rceil$.


title: Moduli spaces of reflexive sheaves of rank 2

abstract:
  Let \sF be a coherent rank 2 sheaf on a scheme Y \subset \proj{n} of
dimension at least two. In this paper we study the relationship between the
functor which deforms a pair (\sF,\sigma), \sigma \in H^0(\sF), and the functor
which deforms the corresponding pair (X,\xi) given as in the Serre
correspondence. We prove that the scheme structure of e.g. the moduli scheme
M_Y(P) of stable sheaves on a threefold Y at (\sF), and the scheme structure at
(X) of the Hilbert scheme of curves on Y are closely related. Using this
relationship we get criteria for the dimension and smoothness of M_Y(P) at
(\sF), without assuming Ext^2(\sF,\sF) = 0. For reflexive sheaves on Y =
\proj{3} whose deficiency module M = H_{*}^1(\sF) satisfies Ext^2(M,M) = 0 in
degree zero (e.g. of diameter at most 2), we get necessary and sufficient
conditions of unobstructedness which coincide in the diameter one case. The
conditions are further equivalent to the vanishing of certain graded Betti
numbers of the free graded minimal resolution of H_{*}^0(\sF). It follows that
every irreducible component of M_{\proj{3}}(P) containing a reflexive sheaf of
diameter one is reduced (generically smooth). We also determine a good lower
bound for the dimension of any component of M_{\proj{3}}(P) which contains a
reflexive stable sheaf with "small" deficiency module M.


title:
Giant Uniaxial Anisotropy in the Magnetic and Transport Properties of
  CePd5Al2

abstract:
  Electrical resistivity rho, magnetic susceptibility chi, magnetization M and
specific heat measurements are reported on a singlecrystalline sample of
CePd5Al2, showing successive antiferromagnetic orderings at T_N1=4.1 K and
T_N2=2.9 K. The temperature dependence of T_N1 shows a Kondo metal behavior
with large anisotropy, rho_c/rho_a=3.2 at 20 K, and opening of a superzone gap
along the tetragona c-direction below T_N1. Both T_N1 and T_N2 gradually
increase with applying pressure up to 2.5 GPa. The data of chi(T) and M(B) in
the paramagnetic state were analyzed using a crystalline electric field (CEF)
model. It led to a Kramers doublet ground state with wave functions consisting
primarily of |+-5/2>, whose energy level is isolated from the excited states by
230 and 300 K. This CEF effect gives rise to the large anisotropy in the
paramagnetic state. In the ordered state, the uniaxial magnetic anisotropy is
manifested as M_c/M_a=20 in B=5 T and at 1.9 K, and chi_c/chi_a=25 in B=0.1 T
and at 4 K. This huge uniaxial magnetic anisotropy in the antiferromagnetic
states can be interpreted in terms of isotropic magnetic interaction among the
Ce^{3+} moments governed by the strong CEF. In powder neutron diffraction
experiments, magnetic reflections were observed owing to the antiferromagnetic
ordered states below T_N1, however, no additional reflection was found below
T_N2.


title:
Order-disorder transition induced by deformation of vortex lines at the
  twin boundaries in YBa$_2$Cu$_3$O$_{7-\delta}$-crystals: test of the
  Lindemann criteria

abstract:
  We show that rotation of the magnetic field off the plane of twin boundaries
(TB's) induces transition of an ordered vortex solid phase to a disordered one.
This transition arises due to appearance of transverse deformations of vortex
lines near the TB's, $u_{t,TB}$, the amplitude of which satisfies the Lindemann
criteria, $u_{t,rp}=c_La_0$. This order-disorder transition is accompanied by
an increase in the depinning current, by crossover from an elastic creep to
plastic one, and by appearance of the $S$-shaped voltage-current
characteristics.


title:
Study of the Surface of 2003 EL61: the largest carbon-depleted object in
  the trans-neptunian belt

abstract:
  2003 EL61 is the largest member of a group of TNOs with similar orbits and
'unique' spectra (neutral slope in the visible and the deepest water ice
absorption bands ever observed in the TNb). Studying the composition of the
surface of 2003 EL61 provides useful constrains on the origin of this
particular group of TNOs and on the outer Solar system's history.
  We present visible and near-infrared spectra of 2003 EL61 obtained with the
4.2m WHT and the 3.6m TNG at the Roque de los Muchachos Observatory (Canary
Islands, Spain). Near infrared spectra were obtained at different rotational
phases covering almost one complete rotational period. Spectra are fitted using
Hapke scattering models and constraints on the surface composition are derived.
  No significant variations in the spectral slope and in the depth of the water
ice absorption bands at different rotational phases are evident, suggesting
that the surface of 2003 EL61 is homogeneous. The scattering models show that a
1:1 intimate mixture of crystalline and amorphous water ice is the most
probable composition for the surface of this TNO, and constrain the presence of
other minor constituents to a maximum of 8%
  The derived composition suggests that: a) cryovolcanism is unlikely to be the
main resurfacing process responsible for the high presence of water ice on the
surface of these bodies; b) the surface is older than 10^8 yr. Any catastrophic
event, like the collision suggested to be the origin of this population, had to
happen at least 10^8 yr ago; c) the surface of 2003 EL61 is depleted of carbon
chains. According to the orbital parameters of this population, this makes it a
possible source of carbon-depleted Jupiter family comets.


title: Aspects of cosmological expansion in F(R) gravity models

abstract:
  We study cosmological expansion in F(R) gravity using the trace of the field
equations. High frequency oscillations in the Ricci scalar, whose amplitude
increase as one evolves backward in time, have been predicted in recent works.
We show that the approximations used to derive this result very quickly
breakdown in any realistic model due to the non-linear nature of the underlying
problem. Using a combination of numerical and semi-analytic techniques, we
study a range of models which are otherwise devoid of known pathologies. We
find that high frequency asymmetric oscillations and a singularity at finite
time appear to be present for a wide range of initial conditions. We show that
this singularity can be avoided with a certain range of initial conditions,
which we find by evolving the models forwards in time. In addition we show that
the oscillations in the Ricci scalar are highly suppressed in the Hubble
parameter and scale factor.


title: Rank abundance relations in evolutionary dynamics of random replicators

abstract:
  We present a non-equilibrium statistical mechanics description of rank
abundance relations (RAR) in random community models of ecology. Specifically,
we study a multi-species replicator system with quenched random interaction
matrices. We here consider symmetric interactions as well as asymmetric and
anti-symmetric cases. RARs are obtained analytically via a generating
functional analysis, describing fixed-point states of the system in terms of a
small set of order parameters, and in dependence on the symmetry or otherwise
of interactions and on the productivity of the community. Our work is an
extension of Tokita [Phys. Rev. Lett. {\bf 93} 178102 (2004)], where the case
of symmetric interactions was considered within an equilibrium setup. The
species abundance distribution in our model come out as truncated normal
distributions or transformations thereof and, in some case, are similar to
left-skewed distributions observed in ecology. We also discuss the interaction
structure of the resulting food-web of stable species at stationarity, cases of
heterogeneous co-operation pressures as well as effects of finite system size
and of higher-order interactions.


title:
Structural approach to unambiguous discrimination of two mixed quantum
  states

abstract:
  We analyze the optimal unambiguous discrimination of two arbitrary mixed
quantum states. We show that the optimal measurement is unique and we present
this optimal measurement for the case where the rank of the density operator of
one of the states is at most 2 ("solution in 4 dimensions"). The solution is
illustrated by some examples. The optimality conditions proved by Eldar et al.
[Phys. Rev. A 69, 062318 (2004)] are simplified to an operational form. As an
application we present optimality conditions for the measurement, when only one
of the two states is detected. The current status of optimal unambiguous state
discrimination is summarized via a general strategy.


title: Neutron scattering study of Kondo lattice antiferromagnet YbNiSi3

abstract:
  The Kondo lattice antiferromagnet YbNiSi3 was investigated by neutron
scattering. The magnetic structure of YbNiSi3 was determined by neutron
diffraction on a single-crystalline sample. Inelastic scattering experiments
were also performed on a pulverized sample to study the crystalline electric
field (CEF) excitations. Two broad CEF excitations were observed, from which
the CEF parameters were determined. The temperature dependence of the magnetic
susceptibility chi and the magnetic specific heat Cmag were calculated using
the determined CEF model, and compared with previous results.


title:
A new reduced network to simulate detonations in superbursts from mixed
  H/He accretors

abstract:
  We construct a new reduced nuclear reaction network able to reproduce the
energy production due to the photo-disintegration of heavy elements such as Ru,
which are believed to occur during superbursts in mixed H/He accreting systems.
We use this network to simulate a detonation propagation, inside a mixture of
C/Ru. As our reference, we use a full nuclear reaction network, including 14758
reactions on 1381 nuclides. Until the reduced and full networks converge to a
good level of accuracy in the energy production rate, we iterate between the
hydrodynamical simulation, with a given reduced network, and the readjustment
of a new reduced network, on the basis of previously derived hydrodynamical
profiles. We obtain the thermodynamic state of the material after the passage
of the detonation, and the final products of the combustion. Interestingly, we
find that all reaction lengths can be resolved in the same simulation. This
will enable C/Ru detonations to be more easily studied in future
multi-dimensional simulations, than pure carbon ones. We underline the
dependence of the combustion products on the initial mass fraction of Ru. In
some cases, a large fraction of heavy nuclei, such as Mo, remains after the
passage of the detonation front. In other cases, the ashes are principally
composed of iron group elements.


title:
Interacting cosmic fluids in power-law Friedmann-Robertson-Walker
  cosmological models

abstract:
  We provide a detailed description for power--law scaling
Friedmann-Robertson-Walker cosmological scenarios dominated by two interacting
perfect fluid components during the expansion. As a consequence of the mutual
interaction between the two fluids, neither component is conserved separately
and the energy densities are proportional to $1/t^{2}$. It is shown that in
flat FRW cosmological models there can exist interacting superpositions of two
perfect fluids (each of them having a positive energy density) which accelerate
the expansion of the universe. In this family there also exist flat power law
cosmological scenarios where one of the fluids may have a ``cosmological
constant" or "vacuum energy" equation of state ($p =-\rho$) interacting with
the other component; this scenario exactly mimics the behavior of the standard
flat Friedmann solution for a single fluid with a barotropic equation of state.
These possibilities of combining interacting perfect fluids do not exist for
the non-interacting mixtures of two perfect cosmic fluids, where the general
solution for the scale factor is not described by power--law expressions and
has a more complicated behavior. In this study is considered also the
associated single fluid model interpretation for the interaction between two
fluids.


title:
The Future of Scientific Simulations: from Artificial Life to Artificial
  Cosmogenesis

abstract:
  This philosophical paper explores the relation between modern scientific
simulations and the future of the universe. We argue that a simulation of an
entire universe will result from future scientific activity. This requires us
to tackle the challenge of simulating open-ended evolution at all levels in a
single simulation. The simulation should encompass not only biological
evolution, but also physical evolution (a level below) and cultural evolution
(a level above). The simulation would allow us to probe what would happen if we
would "replay the tape of the universe" with the same or different laws and
initial conditions. We also distinguish between real-world and artificial-world
modelling. Assuming that intelligent life could indeed simulate an entire
universe, this leads to two tentative hypotheses. Some authors have argued that
we may already be in a simulation run by an intelligent entity. Or, if such a
simulation could be made real, this would lead to the production of a new
universe. This last direction is argued with a careful speculative
philosophical approach, emphasizing the imperative to find a solution to the
heat death problem in cosmology. The reader is invited to consult Annex 1 for
an overview of the logical structure of this paper. -- Keywords: far future,
future of science, ALife, simulation, realization, cosmology, heat death,
fine-tuning, physical eschatology, cosmological natural selection, cosmological
artificial selection, artificial cosmogenesis, selfish biocosm hypothesis,
meduso-anthropic principle, developmental singularity hypothesis, role of
intelligent life.


title:
Depth of segments and circles through points enclosing many points: a
  note

abstract:
  Neumann-Lara and Urrutia showed in 1985 that in any set of n points in the
plane in general positionthere is always a pair of points such that any circle
through them contains at least (n-2)/60 points. In a series of papers, this
result was subsequently improved till n/4.7, which is currently the best known
lower bound. In this paper we propose a new approach to the problem that allows
us, by using known results about j-facets of sets of points in $R^3$, to give a
simple proof of a somehow stronger result: there is always a pair of points
such that any circle through them has, both inside and outside, at least n/4.7
points.


title: Gauss Optics and Gauss Sum on an Optical Phenomena

abstract:
  In the previous article (Found Phys. Lett. {\bf{16}} 325-341), we showed that
a reciprocity of the Gauss sums is connected with the wave and particle
complementary. In this article, we revise the previous investigation by
considering a relation between the Gauss optics and the Gauss sum based upon
the recent studies of the Weil representation for a finite group.


title: Self-Corrected Min-Sum decoding of LDPC codes

abstract:
  In this paper we propose a very simple but powerful self-correction method
for the Min-Sum decoding of LPDC codes. Unlike other correction methods known
in the literature, our method does not try to correct the check node processing
approximation, but it modifies the variable node processing by erasing
unreliable messages. However, this positively affects check node messages,
which become symmetric Gaussian distributed, and we show that this is
sufficient to ensure a quasi-optimal decoding performance. Monte-Carlo
simulations show that the proposed Self-Corrected Min-Sum decoding performs
very close to the Sum-Product decoding, while preserving the main features of
the Min-Sum decoding, that is low complexity and independence with respect to
noise variance estimation errors.


title: A Primer in Quantum Mechanics for NMR Students

abstract:
  An introduction in quantum mechanical theory for NMR students which covers
basic concepts and calculations.


title: On the running of the bare coupling in SU(N) lattice gauge theories

abstract:
  Interpreting the way that the SU(3) bare lattice coupling runs with the
lattice spacing is complicated by the fact that there is a smooth cross-over
region in which the strong coupling expansion transforms into a weak-coupling
one. For N > 4, however, there is a first order bulk transition that cleanly
separates the strong and weak coupling regimes. We find that in this case the
calculated string tension can be readily fitted throughout the weak coupling
region by a standard 3-loop expression modified by lattice spacing corrections
of the expected form. While our fits demand the presence of the latter, they do
not constrain the perturbative coupling scheme enough to enable us to extract a
usefully accurate value of a(beta) in units of Lambda_MSbar. To resolve this
ambiguity we turn to SU(3) where we use the Schrodinger Functional coupling
scheme to extract a value of r_0 x Lambda_SF as a benchmark. We then find that
the Parisi mean-field improved coupling scheme closely reproduces this result.
We also develop a comparison between different schemes that does not rely on
the calculation of any physical quantity and which can therefore be applied
much further into weak coupling. Again the Parisi scheme is favoured over the
others that we compare. Using the mean-field scheme we have fitted the values
of the string tension that have been calculated for N=2 to N=8, to obtain
Lambda_MSbar/sqrt(sigma) = 0.503(2)(40) + 0.33(3)(3)/N^2 for N > 2, where the
first error is statistical and the second is our estimate of the systematic
error from all sources.


title:
Quantum simulator for the Ising model with electrons floating on a
  helium film

abstract:
  We propose a physical setup that can be used to simulate the quantum dynamics
of the Ising model with present-day technology. Our scheme consists of
electrons floating on superfluid helium which interact via Coulomb forces. In
the limit of low temperatures, the system will stay near the ground state where
its Hamiltonian is equivalent to the Ising model and thus shows phenomena such
as quantum criticality. Furthermore, the proposed design could be generalized
in order to study interacting field theories (e.g., $\lambda\phi^4$) and
adiabatic quantum computers.


title: Min-Max decoding for non binary LDPC codes

abstract:
  Iterative decoding of non-binary LDPC codes is currently performed using
either the Sum-Product or the Min-Sum algorithms or slightly different versions
of them. In this paper, several low-complexity quasi-optimal iterative
algorithms are proposed for decoding non-binary codes. The Min-Max algorithm is
one of them and it has the benefit of two possible LLR domain implementations:
a standard implementation, whose complexity scales as the square of the Galois
field's cardinality and a reduced complexity implementation called selective
implementation, which makes the Min-Max decoding very attractive for practical
purposes.


title:
Mixed three-point correlation functions of the nonlinear integrated
  Sachs-Wolfe effect and their detectability

abstract:
  In this paper I investigate the family of mixed three-point correlation
functions <tau^q gamma^{3-q}>, q=0,1,2, between the integrated Sachs-Wolfe
(iSW) temperature perturbation tau and the galaxy overdensity gamma as a tool
for detecting the gravitational interaction of cosmic microwave background
(CMB) photons with the potentials of nonlinearly evolving cosmological
structures. Both the iSW-effect as well as the galaxy overdensity are derived
in hyper-extended perturbation theory to second order and I emphasise the
different parameter sensitivities of the linear and non-linear iSW-effect. I
examine the configuration dependence of the relevant bispectra, quantify their
sensitivities and discuss their degeneracies with respect to the cosmological
parameters Omega_m, sigma_8, h and the dark energy equation of state parameter
$w$. I give detection sigificances for combining PLANCK CMB data and the DUNE
galaxy sample, by using a quadratic approximation for the likelihood with
LambdaCDM as the fiducial cosmology: The combination of PLANCK with DUNE should
be able to reach a cumulative signal to noise ratio of ~0.6sigma for the
bispectrum <tau gamma^2> up to l=2000, where the most important noise source
are the primary CMB fluctuations.


title: Algebraic-geometric codes from vector bundles and their decoding

abstract:
  Algebraic-geometric codes can be constructed by evaluating a certain set of
functions on a set of distinct rational points of an algebraic curve. The set
of functions that are evaluated is the linear space of a given divisor or,
equivalently, the set of section of a given line bundle. Using arbitrary rank
vector bundles on algebraic curves, we propose a natural generalization of the
above construction. Our codes can also be seen as interleaved versions of
classical algebraic-geometric codes. We show that the algorithm of Brown,
Minder and Shokrollahi can be extended to this new class of codes and it
corrects any number of errors up to $t^{*} - g/2$, where $t^{*}$ is the
designed correction capacity of the code and $g$ is the curve genus.


title: VHE Gamma-rays from Galactic X-ray Binary Systems

abstract:
  The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR
B1259-63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus
X-1 by MAGIC, provides a clear evidence of very efficient acceleration of
particles to multi-TeV energies in X-ray binaries. These observations
demonstrate the richness of non-thermal phenomena in compact galactic objects
containing relativistic outflows or winds produced near black holes and neutron
stars. I review here some of the main observational results on very high energy
(VHE) gamma-ray emission from X-ray binaries, as well as some of the proposed
scenarios to explain the production of VHE gamma-rays. I put special emphasis
on the flare TeV emission, suggesting that the flaring activity might be a
common phenomena in X-ray binaries.


title:
A new luminosity function for galaxies as given by the mass-luminosity
  relationship

abstract:
  The search for a luminosity function for galaxies both alternative or
companion to a Schechter function is a key problem in the reduction of data
from catalogs of galaxies. Two luminosity functions for galaxies can be built
starting from two distributions of mass as given by the fragmentation. A first
overall distribution function is the Kiang function that represents a useful
description of the area and volume distribution of the Poisson Voronoi
diagrams. The second distribution, that covers the case of low mass galaxies,
is the truncated Pareto distribution : in this model we have a natural bound
due to the minimum mass/luminosity observed and an upper bound (function of the
considered environment) represented by the boundary with the observed
mass/luminosity overall behaviour. The mass distribution is then converted into
a luminosity distribution through a standard mass-luminosity relationship.


title: Irreversibility, Molecular Chaos, and A Simple Proof of the Second Law

abstract:
  The irreversibility in a statistical system is traced to its probabilistic
evolution, and the molecular chaos assumption is not its unique consequence as
is commonly believed. Under the assumption that the rate of change of the each
microstate probability vanishes only as time diverges, we prove that the
entropy of a system at constant energy cannot decrease with time.


title:
Nonmonotonic reversible branch in four model granular beds subjected to
  vertical vibration

abstract:
  We present results from four independent models of a granular assembly
subjected to tapping. We find that the steady-state packing fraction as a
function of the tapping intensity is nonmonotonic. In particular, for high
tapping intensities, we observe an increase of the packing fraction with
tapping strength. This finding challenges the current understanding of
compaction of granular media since the steady-state packing fraction is
believed to decrease monotonically with increasing tapping intensity. We
propose an explanation of our results based on the properties of the arches
formed by the particles.


title: Understanding spin transport from the motion in SU(2)$\times$U(1) fields

abstract:
  Starting from a continuum constituted by charged tops, we formulate the
classical counterpart of a previously obtained covariant continuity-like
equation for the spin current. Such a formulism provides an intuitive picture
to elucidate the non-conservation of the spin current and to interpret the
condition for the emergence of an infinite spin relaxation time. It also
facilitates the discussion on the spin precession in a one-dimensional quantum
wire with Dresselhaus and Rashba spin-orbit couplings. Furthermore, we derive
the diffusion equations for both the charge and spin densities and find that
they couple to each other due to the Zitterbewegung.


title: Thermal state entanglement in harmonic lattices

abstract:
  We investigate the entanglement properties of thermal states of the harmonic
lattice in one, two and three dimensions. We establish the value of the
critical temperature for entanglement between neighbouring sites and give
physical reasons. Further sites are shown to be entangled only due to boundary
effects. Other forms of entanglement are addressed in the second part of the
paper by using the energy as witness of entanglement. We close with a
comprehensive diagram showing the different phases of entanglement versus
complete separability and propose techniques to swap and tune entanglement
experimentally.


title: Strong electron-phonon interaction in multiband superconductors

abstract:
  We discuss the effects of anisotropy on superconducting critical temperature
and order parameter in a strongly coupled regime. The multiband representation
is used as a model for anisotropy. We show that strong coupling effects in
multiband superconductors lead to pair-breaking due to interband coupling
because soft phonon modes play the same role as usual impurities. This effect
makes the order parameters in different bands equal to each other and limits
the upper bound on critical temperature.


title: Optimizing Web Sites for Customer Retention

abstract:
  With customer relationship management (CRM) companies move away from a mainly
product-centered view to a customer-centered view. Resulting from this change,
the effective management of how to keep contact with customers throughout
different channels is one of the key success factors in today's business world.
Company Web sites have evolved in many industries into an extremely important
channel through which customers can be attracted and retained. To analyze and
optimize this channel, accurate models of how customers browse through the Web
site and what information within the site they repeatedly view are crucial.
Typically, data mining techniques are used for this purpose. However, there
already exist numerous models developed in marketing research for traditional
channels which could also prove valuable to understanding this new channel. In
this paper we propose the application of an extension of the Logarithmic Series
Distribution (LSD) model repeat-usage of Web-based information and thus to
analyze and optimize a Web Site's capability to support one goal of CRM, to
retain customers. As an example, we use the university's blended learning web
portal with over a thousand learning resources to demonstrate how the model can
be used to evaluate and improve the Web site's effectiveness.


title:
Exact expression for Drude conductivity in one-dimension with an
  arbitrary potential

abstract:
  An exact expression for the Drude conductivity in one dimension is derived
under the presence of an arbitrary potential. In getting the conductivity the
influence of the electric field on the crystal potential is taken into account.
This coupling leads to a systematic deformation of the potential and
consequently to a significant modification of the charge transport. The
corrections to the conventional Drude conductivity are determined by the
configurational part of the partition function. The activation energy for the
conductivity process is expressed by a combination of the free energy of the
underlying equilibrium system. The electric current is calculated in the linear
response regime by solving the Smoluchowski equation. The steady state solution
differs significantly from the equilibrium distribution. In case of a tight
binding potential the conductivity offers corrections depending on the
amplitude of the potential. As a further application we discuss nanocontacts
with piecewise constant potentials. The electric conductivity is corrected by
the potential height.


title:
Constraints on scalar-tensor models of dark energy from observational
  and local gravity tests

abstract:
  We construct a family of viable scalar-tensor models of dark energy (DE)
which possess a phase of late-time acceleration preceded by a standard matter
era, while at the same time satisfying the local gravity constraints (LGC). The
coupling Q between the scalar field and the non-relativistic matter in the
Einstein frame is assumed to be constant in our scenario, which is a
generalization of f(R) gravity theories corresponding to the coupling
Q=-1/sqrt{6}. We find that these models can be made compatible with local
gravity constraints even when |Q| is of the order of unity through a chameleon
mechanism, if the scalar-field potential is chosen to have a sufficiently large
mass in the high-curvature regions. We show that these models generally lead to
the divergence of the equation of state of DE, which occur at smaller redshifts
as the deviation from the LambdaCDM model become more significant. We also
study the evolution of matter density perturbations and employ them to place
bounds on the coupling |Q| as well as model parameters of the field potential
from observations of the matter power spectrum and the CMB anisotropies. We
find that, as long as |Q| is smaller than the order of unity, there exist
allowed parameter regions that are consistent with both observational and local
gravity constraints.


title:
VV124 (UGC4879): A new transitional dwarf galaxy in the periphery of the
  Local Group

abstract:
  We present the first resolved-star photometry of VV124 (UGC4879) and find
that this is the most isolated dwarf galaxy in the periphery of the Local
Group. Based on imaging and spectroscopic follow up observations with the 6m
BTA telescope, we resolve VV124 into 1560 stars down to the limiting magnitude
levels of V~25.6 and I~23.9. The young blue stellar populations and emission
gas are found near the core, but noticeably displaced from the center of the
galaxy as traced by dominant evolved red stars. The mean radial velocity
derived from the spectra of two Blue Supergiant stars, an HII region and
unresolved continuum sources is -80+/-10 km/s. The evolved ``red tangle''
stellar populations, which contains the red giant branch (RGB), are identified
at large galactocentric radii. We use the I-band luminosity function to
determine the distance based on the Tip of RGB method, 1.1+/-0.1 Mpc. This is
~10 times closer than the values usually assumed in the literature, and we
provide revised distance dependent parameters. From the mean (V-I) color of the
RGB, we estimate the mean metallicity as [Fe/H]~-1.37 dex. Despite of its
isolated location, the properties of VV124 are clearly not those of a galaxy in
formation, but rather similar to a transitional dIrr/dSph type.


title: A family of representations of braid groups on surfaces

abstract:
  We propose a family of new representations of the braid groups on surfaces
that extend linear representations of the braid groups on a disc such as the
Burau representation and the Lawrence-Krammer-Bigelow representation.


title:
Quelques in\'egalit\'es effectives entre des fonctions arithm\'etiques
  usuelles

abstract:
  Let us denote by $\tau(n)$ and $\si(n)$ the number and the sum of the
divisors of $n$ and by $\vfi$ Euler's function. We give effective upper bounds
for $\frac{n}{\vfi(n)}$ in terms of $\vfi(n)$, and for $\frac{\si(n)}{n}$ in
terms of $\tau(n)$.


title: On the Computation of the Topology of a Non-Reduced Implicit Space Curve

abstract:
  An algorithm is presented for the computation of the topology of a
non-reduced space curve defined as the intersection of two implicit algebraic
surfaces. It computes a Piecewise Linear Structure (PLS) isotopic to the
original space curve. The algorithm is designed to provide the exact result for
all inputs. It's a symbolic-numeric algorithm based on subresultant
computation. Simple algebraic criteria are given to certify the output of the
algorithm. The algorithm uses only one projection of the non-reduced space
curve augmented with adjacency information around some "particular points" of
the space curve. The algorithm is implemented with the Mathemagix Computer
Algebra System (CAS) using the SYNAPS library as a backend.


title:
Hierarchical Grid-Based Pairwise Key Pre-distribution in Wireless Sensor
  Networks

abstract:
  The security of wireless sensor networks is an active topic of research where
both symmetric and asymmetric key cryptography issues have been studied. Due to
their computational feasibility on typical sensor nodes, symmetric key
algorithms that use the same key to encrypt and decrypt messages have been
intensively studied and perfectly deployed in such environment. Because of the
wireless sensor's limited infrastructure, the bottleneck challenge for
deploying these algorithms is the key distribution. For the same reason of
resources restriction, key distribution mechanisms which are used in
traditional wireless networks are not efficient for sensor networks.
  To overcome the key distribution problem, several key pre-distribution
algorithms and techniques that assign keys or keying material for the networks
nodes in an offline phase have been introduced recently. In this paper, we
introduce a supplemental distribution technique based on the communication
pattern and deployment knowledge modeling. Our technique is based on the
hierarchical grid deployment. For granting a proportional security level with
number of dependent sensors, we use different polynomials in different orders
with different weights. In seek of our proposed work's value, we provide a
detailed analysis on the used resources, resulting security, resiliency, and
connectivity compared with other related works.


title: Single-index Regression models with right-censored responses

abstract:
  In this article, we propose some new generalizations of M-estimation
procedures for single-index regression models in presence of randomly
right-censored responses. We derive consistency and asymptotic normality of our
estimates. The results are proved in order to be adapted to a wide range of
techniques used in a censored regression framework (e.g. synthetic data or
weighted least squares). As in the uncensored case, the estimator of the
single-index parameter is seen to have the same asymptotic behavior as in a
fully parametric scheme. We compare these new estimators with those based on
the average derivative technique of Burke and Lu (2005) through a simulation
study.


title: Multiwavelength study of the transient X-ray binary IGR J01583+6713

abstract:
  We have investigated multiband optical photometric variability and stability
of the H$\alpha$ line profile of the transient X-ray binary IGR J01583+6713. We
set an upper limit of 0.05 mag on photometric variations in the {\it V} band
over a time scale of 3 months. The H$\alpha$ line is found to consist of
non-Gaussian profile and quite stable for a duration of 2 months. We have
identified the spectral type of the companion star to be B2 IVe while distance
to the source is estimated to be $\sim$ 4.0 kpc. Along with the optical
observations, we have also carried out analysis of X-ray data from three short
observations of the source, two with the {\it Swift}--XRT and one with the {\it
RXTE}--PCA. We have detected a variation in the absorption column density, from
a value of 22.0 $\times$ 10$^{22}$ cm$^{-2}$ immediately after the outburst
down to 2.6 $\times$ 10$^{22}$ cm$^{-2}$ four months afterwards. In the
quiescent state, the X-ray absorption is consistent with the optical reddening
measurement of E(B - V) = 1.46 mag. From one of the {\it Swift} observations,
during which the X-ray intensity was higher, we have a possible pulse detection
with a period of 469.2 s. For a Be X-ray binary, this indicates an orbital
period in the range of 216--561 days for this binary system.


title:
Energy partition of seismic coda waves in layered media: theory and
  application to Pinyon Flats Observatory

abstract:
  We have studied the partition of shear, compressional and kinetic energies in
the coda of ten earthquakes recorded on a dense array, located at Pinyon Flats
Observatory (PFO), California. We observe a clear stabilization of the shear to
compressional ($W^s/W^p$) energy ratio in the coda, with an average value of
about 2.8. The ratio between the vertical and horizontal kinetic energies
($V^2/H^2$) can be measured from 5 to 25Hz and shows an abrupt transitionfrom
0.1 in the 5-10Hz band, to about 0.8 in the 15-25Hz band. These measured values
are in sharp contrast with the theoretical prediction for equipartitioned
elastic waves in a homogeneous half-space. To explain these observations, we
have developed a theory of equipartition in a layered elastic half-space. Using
a rigorous spectral decomposition of the elastic wave equation, we define
equipartition as a white noise distributed over the complete set of
eigenfunctions. The theory predicts that close to the resonance frequency of a
low-velocity layer, the ratio between shear and compressional energies strongly
decreases. Using a detailed model of the subsurface at PFO, this
conterintuitive result is found to be in good qualitative and quantitative
agreement with the observations.


title: On (twisted) Lawrence-Krammer representations

abstract:
  Lawrence-Krammer representations (LK-representations for short) are linear
representations of Artin-Tits groups of small type, which are of importance
since they are known to be faithful when the type is spherical, or more
generally when restricted to the monoid. If the construction is essentially
unique for a given small and spherical type, the structure of the set of
LK-representations for a given small type is not understood in general. Another
important question is to ask if there exists an analogue of this construction
in the non-small cases ; a first answer is given in [Digne, On the linearity of
Artin Braid groups. J. Algebra 268, (2003) 39-57], where is constructed a
faithful ``twisted'' LK-representation for the spherical, non-small and
crystallographic types. The aim of this paper is to continue the investigations
on those two topics. Regarding the first one, we classify the
LK-representations of the Artin-Tits monoids and groups of small and affine
type. Concerning the second one, we generalize the construction of op.cit. to
any Artin-Tits monoid that appears as the submonoid of fixed points of an
Artin-Tits monoid of small type under the action of graph automorphisms.


title: Vacancy supersolid of hard-core bosons on the square lattice

abstract:
  The ground state of hard-core bosons on the square lattice with nearest and
next-nearest neighbor repulsion is studied by Quantum Monte Carlo simulations.
A supersolid phase with vacancy condensation and 'star' diagonal ordering is
found for filling less than a quarter. At fillings above one quarter, a
supersolid phase exists between the star and the stripe crystal at
half-filling. No supersolid phase occurs above quarter-filling, if the ground
state at half-filling is either a checkerboard crystal or a superfluid. No
commensurate supersolid phase is observed.


title: Production of heavy and superheavy nuclei in massive fusion reactions

abstract:
  Within the framework of a dinuclear system (DNS) model, the
evaporation-residue excitation functions and the quasi-fission mass yields in
the $^{48}$Ca induced fusion reactions are investigated systematically and
compared with available experimental data. Maximal production cross sections of
superheavy nuclei based on stable actinide targets are obtained. Isotopic
trends in the production of the superheavy elements Z=110, 112-118 based on the
actinide isotopic targets are analyzed systematically. Optimal evaporation
channels and combinations as well as the corresponding excitation energies are
proposed. The possible factors that influencing the isotopic dependence of the
production cross sections are analyzed. The formation of the superheavy nuclei
based on the isotopes U with different projectiles are also investigated and
calculated.


title: First Observation of the Decay D_s^+ to proton anti-neutron

abstract:
  Using e^+e^- -> D_s^*+ D_s^- data collected near the peak D_s production
energy, E_cm=4170 MeV, with the CLEO-c detector, we present the first
observation of the decay D_s^+ -> proton anti-neutron. We measure a branching
fraction B(D_s^+ -> p anti-n = (1.30 +- 0.36 +0.12 -0.16) x 10^-3. This is the
first observation of a charmed meson decaying into a baryon-antibaryon final
state.


title: 0-Cohomology of semigroups

abstract:
  This article is a survey of 0-cohomology of semigroups. The main attention is
devoted to applications.


title:
The Rate Loss of Single-Letter Characterization: The "Dirty" Multiple
  Access Channel

abstract:
  For general memoryless systems, the typical information theoretic solution -
when exists - has a "single-letter" form. This reflects the fact that optimum
performance can be approached by a random code (or a random binning scheme),
generated using independent and identically distributed copies of some
single-letter distribution. Is that the form of the solution of any
(information theoretic) problem? In fact, some counter examples are known. The
most famous is the "two help one" problem: Korner and Marton showed that if we
want to decode the modulo-two sum of two binary sources from their independent
encodings, then linear coding is better than random coding. In this paper we
provide another counter example, the "doubly-dirty" multiple access channel
(MAC). Like the Korner-Marton problem, this is a multi-terminal scenario where
side information is distributed among several terminals; each transmitter knows
part of the channel interference but the receiver is not aware of any part of
it. We give an explicit solution for the capacity region of a binary version of
the doubly-dirty MAC, demonstrate how the capacity region can be approached
using a linear coding scheme, and prove that the "best known single-letter
region" is strictly contained in it. We also state a conjecture regarding a
similar rate loss of single letter characterization in the Gaussian case.


title: The Divisor Matrix, Dirichlet Series and SL(2,Z), II

abstract:
  We examine an elliptic curve constructed in an earlier paper from a certain
representation of $\SL(2,\Z)$ on the space of convergent Dirichlet series. The
curve is observed to be a modular curve for $\Gamma^1(15)$ and a certain orbit
of modular functions is thereby associated with the Riemann zeta function.
Explicit descriptions are given of these functions and of the permutation
action of $\SL(2,\Z)$ on them.


title: A note on Larsen's conjecture and ranks of elliptic curves

abstract:
  Let E be an elliptic curve defined over a number field K. Michael Larsen
conjectured that for any finitely generated subgroup G of Gal(\bar K/K), the
Mordell-Weil rank of E is unbounded in number fields fixed by G. We prove that
the conjecture holds over K=Q for both the analytic rank and the p-infinity
Selmer rank of E for every odd prime p. For arbitrary E/K, we show that
Larsen's conjecture follows from the standard conjectures for ranks of elliptic
curves, provided K has a real place or E has non-integral j-invariant.


title:
Complex Spin Structures and Origin of the Magneto-Electric Coupling in
  YMn2O5

abstract:
  By combining neutron four-circle diffraction and polarized neutron
diffraction techniques we have determined the complex spin structures of a
multiferroic, YMn2O5, that exhibits two ferroelectric phases at low
temperatures. The obtained magnetic structure has spiral components in both the
low temperature ferroelectric phases that are magnetically commensurate and
incommensurate, respectively. Among proposed microscopic theories for the
magneto-electric coupling, our results are consistent with both the
spin-current model that requires a magnetic transverse (cycloidal) spiral
structure in order to induce a spontaneous electric polarization and the
magneto-restriction model. Our results also explain why the electric
polarization changes at the commensurate-to-incommensurate phase transition.


title: Mapping Among Manifolds II

abstract:
  In a previous paper we built a modified Hamiltonian formalism to make
possible explicit maps among manifolds. In this paper the modified formalism
was generalized. As an application, we have built maps among spaces associated
to spinors, as well as maps among Kaehler spaces.


title:
Exact Relations for a Strongly-interacting Fermi Gas from the Operator
  Product Expansion

abstract:
  The momentum distribution in a Fermi gas with two spin states and a large
scattering length has a tail that falls off like 1/k^4 at large momentum k, as
pointed out by Shina Tan. He used novel methods to derive exact relations
between the coefficient of the tail in the momentum distribution and various
other properties of the system. We present simple derivations of these
relations using the operator product expansion for quantum fields. We identify
the coefficient as the integral over space of the expectation value of a local
operator that measures the density of pairs.


title: Equivalence for Differential Equations

abstract:
  We shall study the equivalence problem for ordinary differential equations
with respect to the affine transformations group.


title: Static quark-antiquark potential and Dirac eigenvector correlators

abstract:
  We represent the Polyakov loop correlator as a spectral sum of correlators of
eigenvectors of the lattice Dirac operator. This spectral representation is
studied numerically using quenched SU(3) configurations below and above the
deconfinement temperature. We analyze whether the individual Dirac eigenvector
correlators differ in the confined and deconfined phases. The decay properties
of the normalized Dirac eigenvector correlators turn out to be essentially
identical in the two phases, but the amplitudes change. This change of the
amplitudes shifts the relative contributions of the individual Dirac
eigenvector correlators and is the driving mechanism for the transition from
the confining static potential into the deconfining one.


title: Transport in open spin chains: A Monte Carlo wave-function approach

abstract:
  We investigate energy transport in several two-level atom or spin-1/2 models
by a direct coupling to heat baths of different temperatures. The analysis is
carried out on the basis of a recently derived quantum master equation which
describes the nonequilibrium properties of internally weakly coupled systems
appropriately. For the computation of the stationary state of the dynamical
equations, we employ a Monte Carlo wave-function approach. The analysis
directly indicates normal diffusive or ballistic transport in finite models and
hints toward an extrapolation of the transport behavior of infinite models.


title: Plane recursive trees, Stirling permutations and an urn model

abstract:
  We exploit a bijection between plane recursive trees and Stirling
permutations; this yields the equivalence of some results previously proven
separately by different methods for the two types of objects as well as some
new results. We also prove results on the joint distribution of the numbers of
ascents, descents and plateaux in a random Stirling permutation. The proof uses
an interesting generalized Polya urn


title:
The Extended HST Supernova Survey: The Rate of SNe Ia at z>1.4 Remains
  Low

abstract:
  We use the HST ACS imaging of the two GOODS fields during Cycles 11, 12, and
13 to derive the Type Ia supernova rate in four redshift intervals in the range
0.2<z<1.8. Compared to our previous results based on Cycle 11 observations
only, we have increased the coverage of the search by a factor 2.7, making the
total area searched equivalent to one square degree. The sample now consists of
56 Type Ia supernovae. The rates we derive are consistent with our results
based on the Cycle 11 observations. In particular, the few detected supernovae
at z>1.4 supports our previous result that there is a drop in the Type Ia
supernova rate at high redshift, suggesting a long time delay between the
formation of the progenitor star and the explosion of the supernova. If
described by a simple one-parameter model, we find a characteristic delay time
of 2-3 Gyr. However, a number of recent results based on e.g., low redshift
supernova samples and supernova host galaxy properties suggest that the
supernova delay time distribution is bimodal. In this model, a major fraction
of the Type Ia supernova rate is 'prompt' and follows the star formation rate,
while a smaller fraction of the rate has a long delay time, making this channel
proportional to mass. While our results are fully consistent with the bimodal
model at low redshifts, the low rate we find at z>1.4 appears to contradict
these results. Models that corrects for star formation hidden by dust may
explain at least part of the differences. Here we discuss this possibility
together with other ways to reconcile data and models.


title:
Negative differential conductance induced by electronic correlation in a
  double quantum-dot molecule

abstract:
  Electron tunneling through a two stage Kondo system constituted by a double
quantum-dot molecule side coupled to a quantum wire, under the effect of a
finite external potential is studied. We found that $I$-$V$ characteristic
shows a negative differential conductance region induced by the electronic
correlation. This phenomenon is a consequence of the properties of the two
stage Kondo regime under the effect of an external applied potential that takes
the system out of equilibrium. The problem is solved using the mean-field
finite-$U$ slave-boson formalism.


title: Dynamics of Low-Density Ultracold Rydberg Gases

abstract:
  Population dynamics in weakly-excited clouds of ultracold $^{87}$Rb Rydberg
atoms were studied by means of trap loss, fluorescence detection, and state
dependent stimulated emission. Rydberg atoms were excited to various nl Rydberg
states via continuous two-photon excitation from a magneto-optical trap. A
stimulated emission probe laser was then used to bring the Rydberg atoms down
to the 6P$_{3/2}$ state, allowing state-dependent detection of the Rydberg
atoms. Measurements of trap loss and fluorescent emission reveal information
about the evolution of the Rydberg populations. In particular, population in
the initial Rydberg state quickly transfers to other Rydberg states by a
non-collisional mechanism, likely superradiant emission. The trap-loss
measurements are consistent with black-body ionization as the dominant loss
mechanism.


title: Opposite relation on dual polar spaces and half-spin Grassmann spaces

abstract:
  We characterize the collinearity (adjacency) relation of half-spin Grassmann
spaces in terms of the relation to be opposite in the corresponding
collinearity graphs. Also we show that this characterization does not hold for
dual polar spaces.


title:
RACE-OC Project: Rotation and variability in the open cluster NGC2099
  (M37)

abstract:
  Rotation and solar-type magnetic activity are closely related to each other
in stars of G or later spectral types. Presence and level of magnetic activity
depend on star's rotation and rotation itself is strongly influenced by
strength and topology of the magnetic fields. Open clusters represent
especially useful targets to investigate the connection between rotation and
activity. The open cluster NGC2099 has been studied as a part of the RACE-OC
project, which is aimed at exploring the evolution of rotation and magnetic
activity in the late-type members of open clusters of different ages. Time
series CCD photometric observations of this cluster were collected during
January 2004. The relations between activity manifestations, such as the light
curve amplitude, and global stellar parameters are investigated. We have
discovered 135 periodic variables, 122 of which are candidate cluster members.
Determination of rotation periods of G- and K-type stars has allowed us to
better explore evolution of angular momentum at an age of about 500 Myr. A
comparison with the older Hyades cluster (~625 Myr) shows that the newly
determined distribution of rotation periods is consistent with the scenario of
rotational braking of main-sequence spotted stars as they age. However, a
comparison with the younger M34 cluster (~200 Myr) shows that the G8-K5 members
of these clusters have the same rotation period distribution, that is G8-K5
members in NGC2099 seem to have experienced no significant braking in the age
range from ~200 to ~500 Myr. Finally, NGC2099 members have a level of
photospheric magnetic activity, as measured by light curve amplitude, smaller
than in younger stars of same mass and rotation, suggesting that the activity
level also depends on some other age-dependent parameters.


title: On the Gorenstein locus of some punctual Hilbert schemes

abstract:
  Let $k$ be an algebraically closed field and let $\Hilb_{d}^{G}(\p{N})$ be
the open locus of the Hilbert scheme $\Hilb_{d}(\p{N})$ corresponding to
Gorenstein subschemes. We prove that $\Hilb_{d}^{G}(\p{N})$ is irreducible for
$d\le9$, we characterize geometrically its singularities for $d\le 8$ and we
give some results about them when $d=9$ which give some evidence to a
conjecture on the nature of the singular points in $\Hilb_{d}^{G}(\p{N})$.


title: Dislocation interactions mediated by grain boundaries

abstract:
  The dynamics of dislocation assemblies in deforming crystals indicate the
emergence of collective phenomena, intermittent fluctuations and strain
avalanches. In polycrystalline materials, the understanding of plastic
deformation mechanisms depends on grasping the role of grain boundaries on
dislocation motion. Here the interaction of dislocations and elastic, low angle
grain boundaries is studied in the framework of a discrete dislocation
representation. We allow grain boundaries to deform under the effect of
dislocation stress fields and compare the effect of such a perturbation to the
case of rigid grain boudaries. We are able to determine, both analytically and
numerically, corrections to dislocation stress fields acting on neighboring
grains, as mediated by grain boundary deformation. Finally, we discuss
conclusions and consequences for the avalanche statistics, as observed in
polycrystalline samples.


title: Lorentz-Violating Massive Gravity in Curved Space

abstract:
  In models of modified gravity, extra degrees of freedom usually appear. They
must be removed from the spectrum because they may indicate the presence of
instabilities and because otherwise the model might not agree with observation.
In the present letter, we will discuss a model that modifies General Relativity
through the addition of a Lorentz-violating potential-like term for the metric.
No additional propagating modes and no classical instabilities are present. The
model departs from GR only in the extreme infrared region, and the cosmological
evolution contains a bounce when the size of the Universe is of the same order
of the added deformation.


title: Diffusive shock acceleration in radiation dominated environments

abstract:
  Radio, X-ray, and gamma-ray observations provide us with strong evidence of
particle acceleration to multi-TeV energies in various astrophysical sources.
Diffusive shock acceleration is one of the most successful models explaining
the presence of such high-energy particles. We discuss the impact of inverse
Compton losses on the shock acceleration of electrons that takes place in
radiation dominated environments, i.e. in regions where the radiation energy
density exceeds that of the magnetic field. We perform a numerical calculation,
including an energy-loss term in the transport equation of accelerated
particles. We discuss the implications of this effect on the hard X-ray
synchrotron and gamma-ray inverse Compton radiation, produced by
shock-accelerated electrons in young supernova remnants in the presence of
large radiation fields (e.g. in the Galactic centre). We also discuss possible
implications of our results for clusters of galaxies and gamma-ray binaries. We
demonstrate that the inverse Compton losses of electrons, in the Klein-Nishina
regime, lead to spectra of ultra-relativistic electrons that may significantly
differ from classical diffusive shock acceleration solution. The most prominent
feature is the appearance of a pile-up in the spectrum around the cut-off
energy.


title: A short proof of nonhomogeneity of the pseudo-circle

abstract:
  The pseudo-circle is known to be nonhomogeneous. The original proofs of this
fact were discovered independently by L. Fearnley and J.T. Rogers, Jr. The
purpose of this paper is to provide an alternative, very short proof based on a
result of D. Bellamy and W. Lewis.


title:
Incompressible Liquid, Stripes and Bubbles in rapidly rotating Bose
  atoms at $\nu=1$

abstract:
  We numerically study the system of rapidly rotating Bose atoms at the filling
factor (ratio of particle number to vortex number) $\nu=1$ with the dipolar
interaction. A moderate dipolar interaction stabilizes the incompressible
quantum liquid at $\nu=1$. Further addition induces a collapse of it. The state
after the collapse is a compressible state which has phases with stripes and
bubbles.
  There are two types of bubbles with a different array. We also investigate
models constructed from truncated interactions and the models with the
three-body contact interaction. They also have phases with stripes and bubbles.


title: The Riemann Zeta-Function and the Sine Kernel

abstract:
  We point out an interesting occurrence of the sine kernel in connection with
the shifted moments of the Riemann zeta function along the critical line. We
discuss rigorous results in this direction for the shifted second moment and
for the shifted fourth moment. Furthermore, we conjecture that the sine kernel
also occurs in connection with the higher (even) shifted moments and show that
this conjecture is closely related to a recent conjecture by Conrey, Farmer,
Keating, Rubinstein, and Snaith.


title: Statistics of static avalanches in a random pinning landscape

abstract:
  We study the minimum-energy configuration of a d-dimensional elastic
interface in a random potential tied to a harmonic spring. As a function of the
spring position, the center of mass of the interface changes in discrete jumps,
also called shocks or "static avalanches''. We obtain analytically the
distribution of avalanche sizes and its cumulants within an epsilon=4-d
expansion from a tree and 1-loop resummation, using functional renormalization.
This is compared with exact numerical minimizations of interface energies for
random field disorder in d=2,3. Connections to the Burgers equation and to
dynamic avalanches are discussed.


title:
Anomalous Form Factor of the Neutral Pion in Extended AdS/QCD Model with
  Chern-Simons Term

abstract:
  We propose an extension of the hard-wall AdS/QCD model by including the
Chern-Simons term required to reproduce the chiral anomaly of QCD. In the
framework of this holographic model, we study the vertex function F_{\pi
\gamma^* \gamma^*}(Q_1^2,Q_2^2) which accumulates information about the
coupling of the pion to two (in general virtual) photons. We calculate the
slope of the form factor with one real and one slightly virtual photon and show
that it is close to experimental findings. We analyze the formal limit of large
virtualities and establish that predictions of the holographic model
analytically (including nontrivial dependence on the ratio of photon
virtualities) coincide with those of perturbative QCD with asymptotic pion
distribution amplitude. We also investigate the generalized VMD structure of
F_{\pi \gamma^* \gamma^*}(Q_1^2,Q_2^2) in the extended AdS/QCD model.


title:
Asymptotic Capacity and Optimal Precoding Strategy of Multi-Level
  Precode & Forward in Correlated Channels

abstract:
  We analyze a multi-level MIMO relaying system where a multiple-antenna
transmitter sends data to a multipleantenna receiver through several relay
levels, also equipped with multiple antennas. Assuming correlated fading in
each hop, each relay receives a faded version of the signal transmitted by the
previous level, performs precoding on the received signal and retransmits it to
the next level. Using free probability theory and assuming that the noise power
at the relay levels - but not at the receiver - is negligible, a closed-form
expression of the end-to-end asymptotic instantaneous mutual information is
derived as the number of antennas in all levels grow large with the same rate.
This asymptotic expression is shown to be independent from the channel
realizations, to only depend on the channel statistics and to also serve as the
asymptotic value of the end-to-end average mutual information. We also provide
the optimal singular vectors of the precoding matrices that maximize the
asymptotic mutual information : the optimal transmit directions represented by
the singular vectors of the precoding matrices are aligned on the eigenvectors
of the channel correlation matrices, therefore they can be determined only
using the known statistics of the channel matrices and do not depend on a
particular channel realization.


title:
Enrico Fermi and the Physics and Engineering of a nuclear pile: the
  retrieval of novel documents

abstract:
  We give a detailed account of the recent retrieval of a consistent amount
(about 600 pages) of documents written by Enrico Fermi and/or his
collaborators, coming from different sources previously unexplored. These
documents include articles, patents, reports, notes on scientific and technical
meetings and other papers, mainly testifying Fermi's activity in the 1940s
about nuclear pile physics and engineering. All of them have been carefully
described, pointing out the relevance of the given papers for their scientific
or even historical content. From the analysis of these papers, a number of
important scientific and technical points comes out, putting a truly new light
on the Fermi's (and others') scientific activity about nuclear piles and their
applications. Quite unexpectedly intriguing historical remarks, such as those
regarding the relationships between U.S. and Britain, just after the end of the
war, about nuclear power for pacific and/or military use, or even regarding
long term physics research and post-war research policy, emerge as well.


title: A combinatorial formula for Macdonald polynomials

abstract:
  In this paper we use the combinatorics of alcove walks to give a uniform
combinatorial formula for Macdonald polynomials for all Lie types. These
formulas are generalizations of the formulas of Haglund-Haiman-Loehr for
Macdonald polynoimals of type GL(n). At q=0 these formulas specialize to the
formula of Schwer for the Macdonald spherical function in terms of positively
folded alcove walks and at q=t=0 these formulas specialize to the formula for
the Weyl character in terms of the Littelmann path model (in the positively
folded gallery form of Gaussent-Littelmann).


title: Regular Points of a Subcartesian Space

abstract:
  We discuss properties of the regular part $S_{reg}$ of a subcartesian space
$S$. We show that $S_{reg}$ is open and dense in $S$ and the restriction to
$S_{reg}$ of the tangent bundle of $S$ is locally trivial.


title: Plactic relations for $r$-domino tableaux

abstract:
  The work of C. Bonnaf{\'e}, M. Geck, L. Iancu and T. Lam \cite{Geck-Lam}
shows through two conjectures that $r$-domino tableaux have an important role
in Kazhdan-Lusztig theory of type $B$ with unequal parameters. In this paper we
provide plactic relations on signed permutations which determine whether given
two signed permutations have the same insertion $r$-domino tableaux in
Garfinkle's algorithm \cite{Garfinkle1}.


title: Asymmetry measures for QSOs and companions

abstract:
  An asymmetry index is derived from ellipse-fitting to galaxy images, that
gives weight to faint outer features and is not strongly redshift-dependent.
These measures are made on a sample of 13 2MASS QSOs and their neighbour
galaxies, and a control sample of field galaxies from the same wide-field
imaging data. The QSO host galaxy asymmetries correlate well with visual tidal
interaction indices previously published. The companion galaxies have somewhat
higher asymmetry than the control galaxy sample, and their asymmetry is
inversely correlated with distance from the QSO. The distribution of
QSO-companion asymmetry indices is different from that for matched control
field galaxies at the $\sim95%$ significance level. We present the data and
discuss this evidence for tidal and other disturbances in the vicinity of QSOs.


title: Properties of an algebraic spin liquid on the kagome lattice

abstract:
  In recent work, we argued that a particular algebraic spin liquid (ASL) may
be the ground state of the S = 1/2 kagome lattice Heisenberg antiferromagnet.
This state, which lacks a spin gap, is appealing in light of recent experiments
on herbertsmithite (ZnCu3(OH)6Cl2). Here, we study the properties of this ASL
in more detail, using both the low-energy effective field theory and
Gutzwiller-projected wavefunctions. We identify the competing orders of the ASL
-- among them we find a set of magnetic orders lying at the M-points of the
Brillouin zone, the q = 0 magnetic ordered state, the "Hastings" valence-bond
solid (VBS) state, and a pattern of vector spin chirality ordering
corresponding to one of the Dzyaloshinskii-Moriya (DM) interaction terms
present in herbertsmithite. We discuss the detection of the magnetic and VBS
competing orders in experiments. While we focus on a clean system without DM
interaction, we consider the effects of small DM interaction and argue that,
surprisingly, it leads to spontaneously broken time reversal symmetry (for DM
interaction that preserves XY spin rotation symmetry, there is also XY magnetic
order). Our analysis of the projected wavefunction provides an estimate of the
"Fermi velocity" that characterizes all low-energy excitations of the ASL --
this allows us to estimate the specific heat, which compares favorably with
experiments. We also study the spin and bond correlations of the projected
wavefunction and compare these results with those of the effective field
theory. While the spin correlations in the effective field theory and
wavefunction seem to match rather well (although not completely), the bond
correlations are more puzzling. We conclude with a discussion of experiments in
herbertsmithite and make several predictions.


title: The "Crisis in Fundamental Physics" - Will the LHC Pomeron End it?

abstract:
  SU(5) gauge theory with massless left-handed fermions in the representation
5+15+40+45* (QUD) may have a bound-state S-Matrix that, uniquely, contains the
asymptotically unitary Critical Pomeron and which might also reproduce the full
Standard Model. If so, QUD would provide an underlying unification for the
Standard Model in which very similar massless fermion anomaly dynamics is
responsible for the physics of the strong and electroweak interactions and all
particle masses are generated dynamically. The color sextet quark sector,
responsible for both electroweak symmetry-breaking and dark matter in QUD, is
predicted to produce large cross-section effects at the LHC, with the pomeron
as a vital diagnostic - via TOTEM/CMS and FP420.
  In this talk, the multi-regge construction of high-energy QUD amplitudes is
outlined as is, briefly, the LHC pomeron physics. Surrounding motivational
issues (particularly outstanding QCD problems) and consequences are also
discussed. The S-Matrix anomaly physics is conceptually and philosophically
radical with respect to the current theory paradigm. As a consequence, QUD
could provide a welcome way out of the current ``Crisis in Fundamental
Physics'' with, potentially, it's novel physical applicability resolving a
variety of Standard Model and, perhaps also, cosmology problems - it has zero
vacuum energy.


title:
Non-factorized calculation of the process 3He(e,e'p)2H at medium
  energies

abstract:
  The exclusive process 3He(e,e'p)2H has been analyzed by a non-factorized and
parameter-free approach based upon realistic few-body wave functions
corresponding to the $AV18$ interaction and treating the rescattering of the
struck nucleon within a generalized eikonal approximation. The results of our
calculations, compared with recent JLab experimental data, show that the
left-right asymmetry exhibits a clear dependence upon the final state
interaction demonstrating the breaking down of the factorization approximation
at "negative" and large (> 300 MeV/c) values of the missing momentum.


title: Auxiliary fields in the geometrical relativistic particle dynamics

abstract:
  We describe how to construct the dynamics of relativistic particles
following, either timelike or null curves, by means of an auxiliary variables
method instead of the standard theory of deformations for curves. There are
interesting physical particle models governed by actions that involve higher
order derivatives of the embedding functions of the worldline. We point out
that the mechanical content of such models can be extracted wisely from a lower
order action, which can be performed by implementing in the action a finite
number of constraints that involve the geometrical relationship structures
inherent to a curve and by using a covariant formalism. We emphasize our
approach for null curves. For such systems, the natural time parameter is a
pseudo-arclength whose properties resemble those of the standard proper time.
We illustrate the formalism by applying it to some models for relativistic
particles.


title: Higgs Working Group Summary Report

abstract:
  Report of the Working Group on Higgs Bosons for the Workshop, ``Physics at
TeV Colliders'', Les Houches, France, 11-29 June, 2007.


title: The Fermi surface and f-valence electron count of UPt3

abstract:
  Combining old and new de Haas-van Alphen (dHvA) and magnetoresistance data,
we arrive at a detailed picture of the Fermi surface of the heavy fermion
superconductor UPt3. Our work was partially motivated by a new proposal that
two 5f valence electrons per formula unit in UPt3 are localized by correlation
effects -- agreement with previous dHvA measurements of the Fermi surface was
invoked in its support. Comprehensive comparison with our new observations
shows that this 'partially localized' model fails to predict the existence of a
major sheet of the Fermi surface, and is therefore less compatible with
experiment than the originally proposed 'fully itinerant' model of the
electronic structure of UPt3. In support of this conclusion, we offer a more
complete analysis of the fully itinerant band structure calculation, where we
find a number of previously unrecognized extremal orbits on the Fermi surface.


title: Potential Conservation Laws

abstract:
  We prove that potential conservation laws have characteristics depending only
on local variables if and only if they are induced by local conservation laws.
Therefore, characteristics of pure potential conservation laws have to
essentially depend on potential variables. This statement provides a
significant generalization of results of the recent paper by Bluman, Cheviakov
and Ivanova [J. Math. Phys., 2006, V.47, 113505]. Moreover, we present
extensions to gauged potential systems, Abelian and general coverings and
general foliated systems of differential equations. An example illustrating
possible applications of proved statements is considered. A special version of
the Hadamard lemma for fiber bundles and the notions of weighted jet spaces are
proposed as new tools for the investigation of potential conservation laws.


title:
Doubling Fluctuation-Enhanced Sensing Information by Separating
  Adsorption-Desorption and Difussive Fluctuations

abstract:
  We analyze a (symmetrical) two-sensor arrangement with a joint boundary line
between the sensors for fluctuation-enhanced sensing. We show a way to separate
the adsorption-desorption signal components from the diffusive signal
component. Thus the method generates two independent output spectra which
doubles the sensor information for pattern recognition.


title:
Effect of inelasticity on the phase transitions of a thin vibrated
  granular layer

abstract:
  We describe an experimental and computational investigation of the ordered
and disordered phases of a vibrating thin, dense granular layer composed of
identical metal spheres. We compare the results from spheres with different
amounts of inelasticity and show that inelasticity has a strong effect on the
phase diagram. We also report the melting of an ordered phase to a homogeneous
disordered liquid phase at high vibration amplitude or at large inelasticities.
Our results show that dissipation has a strong effect on ordering and that in
this system ordered phases are absent entirely in highly inelastic materials.


title:
Control of non-Markovian effects in the dynamics of polaritons in
  semiconductor microcavities

abstract:
  We report on time-resolved photoluminescence from semiconductor microcavities
showing that an optically controllable mechanism exists to turn on and off
memory effects in a polariton system. By increasing the laser pumping pulse
intensity we observe revivals of the decaying time-resolved photoluminescence
signal, a manifestly non-Markovian behavior of the optically active polaritons.
Based on an open quantum system approach we perform a comprehensive analytical
and numerical study of the coupling of optically active polaritons to a
structured reservoir to confirm the origin of the observed features. Our
findings show that negative detunings and strong excitation should occur
simultaneously for memory effects to take place.


title: Searching for t-bar t Resonances at the Large Hadron Collider

abstract:
  Many new physics models predict resonances with masses in the TeV range which
decay into a pair of top quarks. With its large cross section, t-bar t
production at the Large Hadron Collider (LHC) offers an excellent opportunity
to search for such particles. We present a detailed study of the discovery
potential of the CERN Large Hadron Collider for Kaluza-Klein (KK) excitations
of the gluon in bulk Randall-Sundrum (RS) models in the t-bar t -> ell^+/- nu
b-bar bq-bar q' (ell=e, mu) final state. We utilize final states with one or
two tagged b-quarks, and two, three or four jets (including b-jets). Our
calculations take into account the finite resolution of detectors, the energy
loss due to b-quark decays, the expected reduced b-tagging efficiency at large
t-bar t invariant masses, and include the background originating from Wb-bar
b+jets, (Wb+W-bar b)+jets, W+jets, and single top + jets production. We derive
semi-realistic 5 sigma discovery limits for nine different KK gluon scenarios,
and compare them with those for KK gravitons, and a Z_H boson in the Littlest
Higgs model. We also analyze the capabilities of the LHC experiments to
differentiate between individual KK gluon models and measure the couplings of
KK gluons to quarks. We find that, for the parameters and models chosen, KK
gluons with masses up to about 4 TeV can be discovered at the LHC. The ability
of the LHC to discriminate between different bulk RS models, and to measure the
couplings of the KK gluons is found to be highly model dependent.


title: Point Source Contamination in CMB Non-Gaussianity Analyses

abstract:
  In this paper we analyze the biasing effect of point sources, either thermal
Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength
of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that
the biggest contribution comes from the cross--correlation of the CMB with the
matter density rather than from the poisson term which is conventionally
assumed in these calculations. For the three year WMAP data, we estimate that
point sources could produce a non--Gaussian signature equivalent to a bias in
$f_{NL}$ of $0.35, 0.24, -0.097, -0.13$ in the Ka, Q, V and W bands
respectively. The level of bias we find is largely insufficient to explain the
very high $f_{NL}$ values recently detected by Yadav and Wandelt. For Planck,
we estimate the point source bispectra to contaminate the $f_{NL}$ estimator
with a bias of $1.3, 0.34, -0.25, -0.48$ at $30, 44, 70, 100 {\rm GHz}$
respectively. These results depend on the assumed redshift distribution of the
point sources. However, given the projected Planck sensitivity of $\Delta
f_{NL} \simeq 5$ (95 % C.L.), a good estimate of point sources' properties
including their number density and redshift distribution is essential before
deriving strong conclusions on primordial non--Gaussianity.


title: Lepton Scattering off Few-Nucleon Systems at Medium and High Energies

abstract:
  The interpretation of recent Jlab experimental data on the exclusive process
A(e,e'p)B off few-nucleon systems are analyzed in terms of realistic nuclear
wave functions and Glauber multiple scattering theory, both in its original
form and within a generalized eikonal approximation. The relevance of the
exclusive process 4He(e,e'p)^3H for possible investigations of QCD effects is
illustrated.


title: Magnetothermal study of Dy Stuffed Spin Ice: Dy2(DyxTi2-x)O7-x/2

abstract:
  We have studied the thermodynamics of the stuffed spin ice material,
Dy2(DyxTi2-x)O7-x/2, in which additional Dy3+ replace Ti4+ in the pyrochlore
Dy2Ti2O7. Heat capacity measurements indicate that these materials lose the
spin ice zero point entropy for x >= 0.3, sharply contrasting with results on
the analogous Ho materials. A finite ac susceptibility is observed as T ~ 0 in
both the Ho and Dy materials with x = 0.67, which suggests that spin
fluctuations persist down to T ~ 0. We propose that both the entropy and
susceptibility data may be explained as a result of domains of local pyrochlore
type structural order in these materials.


title: Qantum theory of optomechanical cooling

abstract:
  We review the quantum theory of cooling of a mechanical oscillator subject to
the radiation pressure force due to light circulating inside a driven optical
cavity. Such optomechanical setups have been used recently in a series of
experiments by various groups to cool mechanical oscillators (such as
cantilevers) by factors reaching $10^{5}$, and they may soon go to the ground
state of mechanical motion. We emphasize the importance of the
sideband-resolved regime for ground state cooling, where the cavity ring-down
rate is smaller than the mechanical frequency. Moreover, we illustrate the
strong coupling regime, where the cooling rate exceeds the cavity ring-down
rate and where the driven cavity resonance and the mechanical oscillation
hybridize.


title:
First-Principles Theory of Competing Order Types, Phase Separation, and
  Phonon Scattering in Thermoelectric Pb-Sb-Ag-Te Alloys

abstract:
  Using a first-principles cluster expansion, we shed light on the solid-state
phase diagram and structure of the recently discovered high-performance
thermoelectrics, Pb-Ag-Sb-Te alloys. The observed nanoscale inhomogeneities are
shown to be coherent precipitates of ordered (Ag)m(Sb)n(Te)m+n phases, such as
AgSbTe2, all immiscible with rocksalt PbTe. The solubility is high for PbTe in
AgSbTe2 and low for (Ag,Sb)Te in PbTe (8% vs. 0.6% at 850 K). The differences
in the phonon spectra of PbTe and AgSbTe2 confirm that the inhomogeneities
enhance the thermoelectric performance.


title:
Magnetically-induced ferroelectricity in orthorhombic manganites:
  microscopic origin and chemical trends

abstract:
  The microscopic origin of the magnetically-driven ferroelectricity in
collinear AFM-E orthorhombic manganites is explained by means of
first-principles Wannier functions. We show that the polarization is mainly
determined by the "asymmetric electron hopping" of orbitally-polarized Mn eg
states, implicit in the peculiar in-plane zig-zag spin arrangement in the AFM-E
configuration. In ortho-HoMnO3, Wannier function centers are largely displaced
with respect to corresponding ionic positions, implying that the final
polarization is strongly affected by a purely electronic contribution, at
variance with standard ferroelectrics where the ionic-displacement is dominant.
However, the final value of the polarization is the result of competing
effects, as shown by the opposite signs of the contributions to the
polarization coming from the Mn eg and t2g states. Furthermore, a systematic
analysis of the link between ferroelectricity and the spin, orbital and lattice
degrees of freedom in the manganite series has been carried out, in the aim of
ascertaining chemical trends as a function of the rare-earth ion. Our results
show that the Mn-O-Mn angle is the key quantity in determining the exchange
coupling: upon decreasing the Mn-O-Mn angle, the first- (second-) nearest
neighbor ferromagnetic (antiferromagnetic) interaction decreases (remains
constant), in turn stabilizing either the AFM-A or the AFM-E spin configuration
for weakly or strongly distorted manganites, respectively. The Mn eg
contribution to the polarization dramatically increases with the Mn-O-Mn angle
and decreases with the "long" Mn-O bond length, whereas the Mn t2g contribution
decreases with the "short" Mn-O bond-length, partially cancelling the former
term.


title: Photoassociation of a Bose-Einstein Condensate near a Feshbach Resonance

abstract:
  We measure the effect of a magnetic Feshbach resonance (FR) on the rate and
light-induced frequency shift of a photoassociation resonance in ultracold
$^7$Li. The photoassociation-induced loss rate coefficient, $K_p$, depends
strongly on magnetic field, varying by more than a factor of 10$^4$ for fields
near the FR. At sufficiently high laser intensities, $K_p$ for a thermal gas
decreases with increasing intensity, while saturation is observed for the first
time in a Bose-Einstein condensate. The frequency shift is also strongly
field-dependent and exhibits an anomalous blue-shift for fields just below the
FR.


title: $D_sD^*$ molecule as an axial meson

abstract:
  We use QCD sum rules to study the possible existence of a $D_s\bar{D}^*+
D_s^*\bar{D}$ molecule with the quantum number $J^P=1^+$. We consider the
contributions of condensates up to dimension eight and work at leading order in
$\alpha_s$. We obtain $m_{D_sD^*}=(3.96\pm0.10) \GeV$ around 100 MeV above the
mass of the meson X(3872). The proposed state is a natural generalized state to
the strangeness sector of the X(3872), which was also found to be consistent
with a multiquark state from a previous QCD sum rule analysis.


title:
Anomalous reaction-transport processes: the dynamics beyond the Mass
  Action Law

abstract:
  In this paper we reconsider the Mass Action Law (MAL) for the anomalous
reversible reaction $A\rightleftarrows B$ with diffusion. We provide a
mesoscopic description of this reaction when the transitions between two states
$A$ and $B$ are governed by anomalous (heavy-tailed) waiting-time
distributions. We derive the set of mesoscopic integro-differential equations
for the mean densities of reacting and diffusing particles in both states. We
show that the effective reaction rate memory kernels in these equations and the
uniform asymptotic states depend on transport characteristics such as jumping
rates. This is in contradiction with the classical picture of MAL. We find that
transport can even induce an extinction of the particles such that the density
of particles $A$ or $B$ tends asymptotically to zero. We verify analytical
results by Monte Carlo simulations and show that the mesoscopic densities
exhibit a transient growth before decay.


title: Mass-loss from Red Giants

abstract:
  Although much is known about the nature of winds from hot stars and giants
and supergiants with spectral types earlier than K, there is still much to be
learned regarding the mass-loss process in cool, late-type stars. We will
review the current state of research, with particular reference to observations
and modelling of mass-loss from giant stars in symbiotic systems.


title:
Individual Eigenvalue Distributions of Chiral Random Two-Matrix Theory
  and the Determination of F_pi

abstract:
  Dirac operator eigenvalues split into two when subjected to two different
external vector sources. In a specific finite-volume scaling regime of gauge
theories with fermions, this problem can be mapped to a chiral Random
Two-Matrix Theory. We derive analytical expressions to leading order in the
associated finite-volume expansion, showing how individual Dirac eigenvalue
distributions and their correlations equivalently can be computed directly from
the effective chiral Lagrangian in the epsilon-regime. Because of its
equivalence to chiral Random Two-Matrix Theory, we use the latter for all
explicit computations. On the mathematical side, we define and determine gap
probabilities and individual eigenvalue distributions in that theory at finite
N, and also derive the relevant scaling limit as N is taken to infinity. In
particular, the gap probability for one Dirac eigenvalue is given in terms of a
new kernel that depends on the external vector source. This expression may give
a new and simple way of determining the pion decay constant F_pi from lattice
gauge theory simulations.


title:
The Evolution of the Multiplicity of Embedded Protostars II: Binary
  Separation Distribution & Analysis

abstract:
  We present the Class I protostellar binary separation distribution based on
the data tabulated in the companion paper. We verify the excess of Class I
binary stars over solar-type main-sequence stars, especially at separations
beyond 500 AU. Although our sources are in nearby star forming regions
distributed across the entire sky (including Orion), none of our objects are in
a high stellar density environment. The binary separation distribution changes
significantly during the Class I phase, and the binary frequency at separations
greater than 1000 AU declines steadily with respect to spectral index. Despite
these changes, the binary frequency remains constant until the end of the Class
I phase, when it drops sharply. We propose a scenario to account for the
changes in the Class I binary separation distribution. This scenario postulates
that companions with a separation greater than ~1000 AU were ejected during the
Class 0 phase, but remain gravitationally bound due to the mass of the
envelope. As the envelope dissipates, these companions become unbound and the
binary frequency at wide separations declines. This scenario predicts that a
large number of Class 0 objects should be non-hierarchical multiple systems,
and that many Class I YSOs with a widely separated companion should also have a
very close companion. We also find that Class I protostars are not dynamically
pristine, and have experienced dynamical evolution before they are visible as
Class I objects. For the first time, evidence is presented showing that the
Class I binary frequency and the binary separation distribution strongly depend
on the star forming environment. The reason for this dependence remains
unclear.


title:
A Statistical Description of AGN Jet Evolution from the VLBA Imaging and
  Polarimetry Survey (VIPS)

abstract:
  A detailed analysis of the evolution of the properties of core-jet systems
within the VLBA Imaging and Polarimetry Survey (VIPS) is presented. We find a
power-law relationship between jet intensity and width that suggests for the
typical jet, little if any energy is lost as it moves away from its core. Using
VLA images at 1.5 GHz, we have found evidence that parsec-scale jets tend to be
aligned with the the direction of emission on kiloparsec scales. We also found
that this alignment improves as the jets move farther from their cores on
projected scales as small as ~50-100 pc. This suggests that realignment of jets
on these projected scales is relatively common. We typically find a modest
amount of bending (a change in jet position angle of ~5 deg.) on these scales,
suggesting that this realignment may typically occur relatively gradually.