title:
Causal signal transmission by quantum fields. II. Quantum-statistical
  response of interacting bosons

abstract:
  We analyse nonperturbatively signal transmission patterns in Green's
functions of interacting quantum fields. Quantum field theory is re-formulated
in terms of the nonlinear quantum-statistical response of the field. This
formulation applies equally to interacting relativistic fields and
nonrelativistic models. Of crucial importance is that all causality properties
to be expected of a response formulation indeed hold. Being by construction
equivalent to Schwinger's closed-time-loop formalism, this formulation is also
shown to be related naturally to both Kubo's linear response and Glauber's
macroscopic photodetection theories, being a unification of the two with
generalisation to the nonlinear quantum-statistical response problem. In this
paper we introduce response formulation of bosons; response reformulation of
fermions will be subject of a separate paper.


title: Hypernuclear physics legacy and heritage of Dick Dalitz

abstract:
  The major contributions of Richard H. Dalitz to hypernuclear physics, since
his first paper in 1955 to his last one in 2005 covering a span of 50 years
during which he founded and led the theoretical study of hypernuclei, are
reviewed from a personal perspective. Topical remarks on the search for
quasi-bound antikaon-nuclear states and on kaon condensation are made.


title: Reconstruction of p-disconnected graphs

abstract: We prove that Kelly-Ulam conjecture is true for p-disconnected graphs.


title:
Scaling properties of the asymmetric exclusion process with long-range
  hopping

abstract:
  The exclusion process in which particles may jump any distance l>=1 with the
probability that decays as l^-(1+sigma) is studied from coarse-grained equation
for density profile in the limit when the lattice spacing goes to zero. For
1<sigma<2, the usual diffusion term of this equation is replaced by the
fractional one, which affects dynamical-scaling properties of the late-time
approach to the stationary state. When applied to an open system with totally
asymmetric hopping, this approach gives two results: first, it accounts for the
sigma-dependent exponent that characterizes the algebraic decay of density
profile in the maximum-current phase for 1<sigma<2, and second, it shows that
in this region of sigma the exponent is of the mean-field type.


title: Convex bodies and algebraic equations on affine varieties

abstract:
  Given an affine variety X and a finite dimensional vector space of regular
functions L on X, we associate a convex body to (X, L) such that its volume is
responsible for the number of solutions of a generic system of functions from
L. This is a far reaching generalization of usual theory of Newton polytopes
(which is concerned with toric varieties). As applications we give new, simple
and transparent proofs of some well-known theorems in both algebraic geometry
(e.g. Hodge Index Theorem) and convex geometry (e.g. Alexandrov-Fenchel
inequality). Our main tools are classical Hilbert theory on degree of
subvarieties of a projective space (in algebraic geometry) and Brunn-Minkowski
inequality (in convex geometric).


title: Finite temperature expectation values of boundary operators

abstract:
  A conjecture is presented for the thermal one-point function of boundary
operators in integrable boundary quantum field theories in terms of form
factors. It is expected to have applications in studying boundary critical
phenomena and boundary flows, which are relevant in the context of condensed
matter and string theory. The conjectured formula is verified by a
low-temperature expansion developed using finite size techniques, which can
also be used to evaluate higher point functions both in the bulk and on the
boundary.


title:
Logarithmic components of the vacant set for random walk on a discrete
  torus

abstract:
  This work continues the investigation, initiated in a recent work by
Benjamini and Sznitman, of percolative properties of the set of points not
visited by a random walk on the discrete torus (Z/NZ)^d up to time uN^d in high
dimension d. If u>0 is chosen sufficiently small it has been shown that with
overwhelming probability this vacant set contains a unique giant component
containing segments of length c_0 log N for some constant c_0 > 0, and this
component occupies a non-degenerate fraction of the total volume as N tends to
infinity. Within the same setup, we investigate here the complement of the
giant component in the vacant set and show that some components consist of
segments of logarithmic size. In particular, this shows that the choice of a
sufficiently large constant c_0 > 0 is crucial in the definition of the giant
component.


title: BPS Wilson Loops on S^2 at Higher Loops

abstract:
  We consider supersymmetric Wilson loops of the variety constructed by
Drukker, Giombi, Ricci, and Trancanelli, whose spatial contours lie on a
two-sphere. Working to second order in the 't Hooft coupling in planar N=4
Supersymmetric Yang-Mills Theory (SYM), we compute the vacuum expectation value
of a wavy-latitude and of a loop composed of two longitudes. We evaluate the
resulting integrals numerically and find that the results are consistent with
the zero-instanton sector calculation of Wilson loops in 2-d Yang-Mills on S^2
performed by Bassetto and Griguolo. We also consider the connected correlator
of two distinct latitudes to third order in the 't Hooft coupling in planar N=4
SYM. We compare the result in the limit where the latitudes become coincident
to a perturbative calculation in 2-d Yang-Mills on S^2 using a light-cone
Wu-Mandelstam-Leibbrandt prescription. We are not able to calculate the SYM
result at the required order in the separation between the latitudes necessary
for a match with 2-d Yang-Mills; the result, however, does not preclude such a
match.


title: Generalized Phase Rules

abstract:
  For a multi-component system, general formulas are derived for the dimension
of a coexisting region in the phase diagram in various state spaces.


title:
The Abnormally Weighting Energy Hypothesis: the Missing Link between
  Dark Matter and Dark Energy

abstract:
  We generalize tensor-scalar theories of gravitation by the introduction of an
abnormally weighting type of energy. This theory of tensor-scalar anomalous
gravity is based on a relaxation of the weak equivalence principle that is now
restricted to ordinary visible matter only. As a consequence, the convergence
mechanism toward general relativity is modified and produces naturally cosmic
acceleration as an inescapable gravitational feedback induced by the
mass-variation of some invisible sector. The cosmological implications of this
new theoretical framework are studied. From the Hubble diagram cosmological
test \textit{alone}, this theory provides an estimation of the amount of
baryons and dark matter in the Universe that is consistent with the independent
cosmological tests of Cosmic Microwave Background (CMB) and Big Bang
Nucleosynthesis (BBN). Cosmic coincidence is naturally achieved from a equally
natural assumption on the amplitude of the scalar coupling strength. Finally,
from the adequacy to supernovae data, we derive a new intriguing relation
between the space-time dependences of the gravitational coupling and the dark
matter mass, providing an example of crucial constraint on microphysics from
cosmology. This glimpses at an enticing new symmetry between the visible and
invisible sectors, namely that the scalar charges of visible and invisible
matter are exactly opposite.


title:
Plasmonic enhancement of fluorescence and Raman scattering by metal
  nanotips

abstract:
  We report modifications to the optical properties of fluorophores in the
vicinity of noble metal nanotips. The fluorescence from small clusters of
quantum dots has been imaged using an apertureless scanning near-field optical
microscope. When a sharp gold tip is brought close to the sample surface, a
strong distance-dependent enhancement of the quantum dot fluorescence is
observed, leading to a simultaneous increase in optical resolution. These
results are consistent with simulations of the electric field and fluorescence
enhancement near plasmonic nanostructures. Highly ordered periodic arrays of
silver nanotips have been fabricated by nanosphere lithography. Using
fluorescence lifetime imaging microscopy, we have created high resolution
spatial maps of the lifetime components of vicinal fluorophores; these show an
order of magnitude increase in decay rate from a localized volume around the
nanotips, resulting in a commensurate enhancement in the fluorescence emission
intensity. Spatial maps of the Raman scattering signal from molecules on the
nanotips shows an enhancement of more than 5 orders of magnitude.


title:
Analysis of quasi-elastic neutrino charged-current scattering off
  $^{16}$O and neutrino energy reconstruction

abstract:
  The charged-current quasi-elastic scattering of muon neutrino on the oxygen
target is analyzed for neutrino energy up to 2.5 GeV using the Relativistic
Distorted-Wave Impulse Approximation (RDWIA). The inclusive cross sections
$d^2\sigma/dQ^2$, calculated within the RDWIA, are lower than the Relativistic
Fermi Gas Model (RFGM) results in the range of the square of four-momentum
transfer $Q^2\leq$0.2 (GeV/c)$^2$. We have also studied the nuclear-model
dependence of the neutrino energy reconstruction accuracy using the
charged-current quasi-elastic events with no detector effects and background.
We found that for one-track events the accuracy is nuclear-model dependent for
neutrino energy up to 2.5 GeV.


title:
Exploring FSR open cluster candidates within $|\Delta\ell|=20^\circ$ of
  the Galactic anticentre

abstract:
  We investigate the nature of a sample of star cluster candidates detected as
stellar overdensities towards the Galactic anticentre. Taken from the catalogue
of Froebrich, Scholz, and Raftery (FSR), the sample contains 28 star cluster
candidates located within $|\Delta\ell|=20^\circ$ of the anticentre. These are
all the candidates in that sector classified by FSR with a high probability of
being star clusters. Our main goals are to determine the fraction of such
candidates that are unknown star clusters, to derive their astrophysical
parameters, and to investigate the relationship of cluster parameters with
position in the Galaxy. When photometric and radial distribution properties are
considered together, an important fraction of the stellar overdensities with a
fluctuation level $\ga3\sigma$ are shown to be star clusters. Thus, catalogues
of star cluster candidates, coupled to the present kind of study, are an
important source for identifying unknown open clusters. Such efforts affect the
understanding of the star-formation rate, cluster dynamical evolution, and
Galactic structure, among others.


title: Hydro-kinetic approach to relativistic heavy ion collisions

abstract:
  We develop a combined hydro-kinetic approach which incorporates a
hydrodynamical expansion of the systems formed in \textit{A}+\textit{A}
collisions and their dynamical decoupling described by escape probabilities.
The method corresponds to a generalized relaxation time ($\tau_{\text{rel}}$)
approximation for the Boltzmann equation applied to inhomogeneous expanding
systems; at small $\tau_{\text{rel}}$ it also allows one to catch the viscous
effects in hadronic component - hadron-resonance gas. We demonstrate how the
approximation of sudden freeze-out can be obtained within this dynamical
picture of continuous emission and find that hypersurfaces, corresponding to a
sharp freeze-out limit, are momentum dependent. The pion $m_{T}$ spectra are
computed in the developed hydro-kinetic model, and compared with those obtained
from ideal hydrodynamics with the Cooper-Frye isothermal prescription. Our
results indicate that there does not exist a universal freeze-out temperature
for pions with different momenta, and support an earlier decoupling of higher
$p_{T}$ particles. By performing numerical simulations for various initial
conditions and equations of state we identify several characteristic features
of the bulk QCD matter evolution preferred in view of the current analysis of
heavy ion collisions at RHIC energies.


title: Evolution of the Kondo state of YbRh2Si2 probed by high field ESR

abstract:
  An electron spin resonance (ESR) study of the heavy fermion compound YbRh2Si2
for fields up to ~ 8 T reveals a strongly anisotropic signal below the single
ion Kondo temperature T_K ~ 25 K. A remarkable similarity between the
T-dependence of the ESR parameters and that of the specific heat and the 29Si
nuclear magnetic resonance data gives evidence that the ESR response is given
by heavy fermions which are formed below T_K and that ESR properties are
determined by their field dependent mass and lifetime. The signal anisotropy,
otherwise typical for Yb{3+} ions, suggests that, owing to a strong
hybridization with conduction electrons at T < T_K, the magnetic anisotropy of
the 4f states is absorbed in the ESR of heavy quasiparticles. Tuning the Kondo
effect on the 4f states with magnetic fields ~ 2 - 8 T and temperature 2 - 25 K
yields a gradual change of the ESR g-factor and linewidth which reflects the
evolution of the Kondo state in this Kondo lattice system.


title: Correlation function of the Schur process with a fixed final partition

abstract:
  We consider a generalization of the Schur process in which a partition
evolves from the empty partition into an arbitrary fixed final partition. We
obtain a double integral representation of the correlation kernel. For a
special final partition with only one row, the edge scaling limit is also
discussed by the use of the saddle point analysis. If we appropriately scale
the length of the row, the limiting correlation kernel changes from the
extended Airy kernel.

categories: math-ph cond-mat.stat-mech hep-th math.MP nlin.SI


title:
The evolution of the binary population in globular clusters: a full
  analytical computation

abstract:
  I present a simplified analytical model that simulates the evolution of the
binary population in a dynamically evolving globular cluster. A number of
simulations have been run spanning a wide range in initial cluster and
environmental conditions by taking into account the main mechanisms of
formation and destruction of binary systems. Following this approach, I
investigate the evolution of the fraction, the radial distribution, the
distribution of mass ratios and periods of the binary population. According to
these simulations, the fraction of surviving binaries appears to be dominated
by the processes of binary ionization and evaporation. In particular, the
frequency of binary systems changes by a factor 1-5 depending on the initial
conditions and on the assumed initial distribution of periods. The comparison
with the existing estimates of binary fractions in Galactic globular clusters
suggests that significant variations in the initial binary content could exist
among the analysed globular cluster. This model has been also used to explain
the observed discrepancy found between the most recent N-body and Monte Carlo
simulations in the literature.


title:
Coupling-geometry-induced temperature scales in the conductance of
  Luttinger liquid wires

abstract:
  We study electronic transport through a one-dimensional, finite-length
quantum wire of correlated electrons (Luttinger liquid) coupled at arbitrary
position via tunnel barriers to two semi-infinite, one-dimensional as well as
stripe-like (two-dimensional) leads, thereby bringing theory closer towards
systems closer to setups realized in experiments. In particular, we compute the
temperature dependence of the linear conductance $G$ of a system without bulk
impurities. The appearance of new temperature scales introduced by the lengths
of overhanging parts of the leads and the wire implies a $G(T)$ which is much
more complex than the power-law behavior described so far for end-coupled
wires. Depending on the precise setup the wide temperature regime of power-law
scaling found in the end-coupled case is broken up in up to five fairly narrow
regimes interrupted by extended crossover regions. Our results can be used to
optimize the experimental setups designed for a verification of Luttinger
liquid power-law scaling.


title: Hermitian Curvature Flow

abstract:
  We define a functional for Hermitian metrics using the curvature of the Chern
connection. The Euler-Lagrange equation for this functional is an elliptic
equation for Hermitian metrics. Solutions to this equation are related to
K\"ahler-Einstein metrics, and are automatically K\"ahler-Einstein under
certain conditions. Given this, a natural parabolic flow equation arises. We
prove short time existence and regularity results for this flow, as well as
stability for the flow near K\"ahler-Einstein metrics with negative or zero
first Chern class.


title:
Structures in surface-brightness profiles of LMC and SMC star clusters:
  evidence of mergers?

abstract:
  The LMC and SMC are rich in binary star clusters, and some mergers are
expected. It is important to characterize single clusters, binary clusters and
candidates to mergers. We selected a sample of star clusters in each Cloud with
this aim. Surface photometry of 25 SMC and 22 LMC star clusters was carried
with the ESO Danish 1.54 m telescope. 23 clusters were observed for the first
time for these purposes. We fitted Elson, Fall and Freeman (1987, EFF) profiles
to the data, deriving structural parameters, luminosities and masses. We also
use isophotal maps to constrain candidates to cluster interactions.} {The
structural parameters, luminosities and masses presented good agreement with
those in the literature. Three binary clusters in the sample have a double
profile. Four clusters (NGC 376, K 50, K 54 and NGC 1810) do not have
companions and present as well important deviations from EFF profiles. The
present sample contains blue and red Magellanic clusters. Extended EFF profiles
were detected in some blue clusters. We find evidence that important deviations
from the body of EFF profiles might be used as a tool to detect cluster
mergers.


title:
Electronic structure and magnetism of a ferromagnetic insulator Cs2AgF4:
  explanation for a lilac colour and a prediction for the anisotropic g factor

abstract:
  Magnetic properties of stechiometric Cs2AgF4 have been calculated within a
very strong correlation limit taking into account a low-symmetry crystal field
and the intra-atomic spin-orbit coupling of the Ag2+ ion. We consistently
explain the insulating ground state and the magnetic state revealing the spin
gap of 2.6 meV below Tc of 14.9 K. A d-d excitation of 2.0-2.3 eV related to
the t2g-eg promotion energy (=10Dq) is a reason for the lilac colour of
Cs2AgF4. Our approach can be experimentally verified by the measurement of the
g factor (gz =2.12 and gy =2.52) and the absorption energy at 2.0-2.3 eV.


title:
Ray-tracing in four and higher dimensional black holes: An analytical
  approximation

abstract:
  We study null rays propagation in a spacetime of static
Schwarzschild--Tangherlini black holes in arbitrary number of dimensions. We
focus on the bending angle and the retarded time delay for rays emitted in the
vicinity of a black hole and propagating to the infinity. We obtain an analytic
expression in terms of elementary functions which approximate the bending angle
and time delay in these spacetimes with high accuracy. We analyze the relative
error of the developed analytic approximations and show that it is quite small
in the complete domain of the parameter space for the rays reaching the
infinity and for different number of the spacetime dimensions. Possible
applications of the obtained results are briefly discussed.


title:
Impurity induced coherent current oscillations in one-dimensional
  conductors

abstract:
  We study theoretically the electronic transport through a single impurity in
a repulsive Luttinger liquid (LL), and find that above a threshold voltage
related to a strength of the impurity potential the DC current $\bar I$ is
accompanied by coherent oscillations with frequency $f = \bar I/e$. There is an
analogy with Josephson junctions: the well-known regime of power-law I-V curves
in the LL corresponds to damping of the Josephson current below the critical
one, while the oscillatory regime in the LL can be compared with the Josephson
oscillations above the critical current.


title: Zeta Nonlocal Scalar Fields

abstract:
  We consider some nonlocal and nonpolynomial scalar field models originated
from p-adic string theory. Infinite number of spacetime derivatives is
determined by the operator valued Riemann zeta function through d'Alembertian
$\Box$ in its argument. Construction of the corresponding Lagrangians L starts
with the exact Lagrangian $\mathcal{L}_p$ for effective field of p-adic tachyon
string, which is generalized replacing p by arbitrary natural number n and then
taken a sum of $\mathcal{L}_n$ over all n. The corresponding new objects we
call zeta scalar strings. Some basic classical field properties of these fields
are obtained and presented in this paper. In particular, some solutions of the
equations of motion and their tachyon spectra are studied. Field theory with
Riemann zeta function dynamics is interesting in its own right as well.


title: Magnetic Excitations in the High Tc Iron Pnictides

abstract:
  We calculate the expected finite frequency neutron scattering intensity based
on the two-sublattice collinear antiferromagnet found by recent neutron
scattering experiments as well as by theoretical analysis on the iron
oxypnictide LaOFeAs. We consider two types of superexchange couplings between
Fe atoms: nearest-neighbor coupling J1 and next-nearest-neighbor coupling J2.
We show how to distinguish experimentally between ferromagnetic and
antiferromagnetic J1. Whereas magnetic excitations in the cuprates display a
so-called resonance peak at (pi,pi) (corresponding to a saddlepoint in the
magnetic spectrum) which is at a wavevector that is at least close to nesting
Fermi-surface-like structures, no such corresponding excitations exist in the
iron pnictides. Rather, we find saddlepoints near (pi,pi/2) and (0,pi/2)(and
symmetry related points). Unlike in the cuprates, none of these vectors are
close to nesting the Fermi surfaces.


title:
Design and Implementation of a Tracer Driver: Easy and Efficient Dynamic
  Analyses of Constraint Logic Programs

abstract:
  Tracers provide users with useful information about program executions. In
this article, we propose a ``tracer driver''. From a single tracer, it provides
a powerful front-end enabling multiple dynamic analysis tools to be easily
implemented, while limiting the overhead of the trace generation. The relevant
execution events are specified by flexible event patterns and a large variety
of trace data can be given either systematically or ``on demand''. The proposed
tracer driver has been designed in the context of constraint logic programming;
experiments have been made within GNU-Prolog. Execution views provided by
existing tools have been easily emulated with a negligible overhead.
Experimental measures show that the flexibility and power of the described
architecture lead to good performance. The tracer driver overhead is inversely
proportional to the average time between two traced events. Whereas the
principles of the tracer driver are independent of the traced programming
language, it is best suited for high-level languages, such as constraint logic
programming, where each traced execution event encompasses numerous low-level
execution steps. Furthermore, constraint logic programming is especially hard
to debug. The current environments do not provide all the useful dynamic
analysis tools. They can significantly benefit from our tracer driver which
enables dynamic analyses to be integrated at a very low cost.


title:
Slow Excitation Trapping in Quantum Transport with Long-Range
  Interactions

abstract:
  Long-range interactions slow down the excitation trapping in quantum
transport processes on a one-dimensional chain with traps at both ends. This is
counter intuitive and in contrast to the corresponding classical processes with
long-range interactions, which lead to faster excitation trapping. We give a
pertubation theoretical explanation of this effect.


title:
Coherent state exchange in multi-prover quantum interactive proof
  systems

abstract:
  We show that any number of parties can coherently exchange any one pure
quantum state for another, without communication, given prior shared
entanglement. Two applications of this fact to the study of multi-prover
quantum interactive proof systems are given. First, we prove that there exists
a one-round two-prover quantum interactive proof system for which no finite
amount of shared entanglement allows the provers to implement an optimal
strategy. More specifically, for every fixed input string, there exists a
sequence of strategies for the provers, with each strategy requiring more
entanglement than the last, for which the probability for the provers to
convince the verifier to accept approaches 1. It is not possible, however, for
the provers to convince the verifier to accept with certainty with a finite
amount of shared entanglement. The second application is a simple proof that
multi-prover quantum interactive proofs can be transformed to have near-perfect
completeness by the addition of one round of communication.


title:
$\pi B_{8}B_{8}$ and $\sigma B_{8}B_{8}$ couplings from a chiral quark
  potential model

abstract:
  From an SU(2)$\otimes $SU(2) chiral quark potential model incorporating
spontaneous chiral symmetry breaking the asymptotic $\pi $ and $\sigma $
exchange pieces of the $NN$ potential are generated. From them the $\pi NN$ and
$\sigma NN$ coupling constants can be extracted. The generalization to
SU(3)$\otimes $SU(3) allows for a determination of $\pi B_{8}B_{8}$ and $%
\sigma B_{8}B_{8}$ coupling constants according to exact SU(3) hadron symmetry.
The implementation of the values of the couplings at $Q^{2}=0$ provided by QCD
sum rules and/or phenomenology makes also feasible the extraction of the
meson-baryon-baryon form factors. In this manner a quite complete knowledge of
the couplings may be attained.


title: Generalization of a criterion for semistable vector bundles

abstract:
  It is known that a vector bundle E on a smooth projective curve Y defined
over an algebraically closed field is semistable if and only if there is a
vector bundle F on Y such that the cohomologies of E\otimes F vanish. We extend
this criterion for semistability to vector bundles on curves defined over
perfect fields. Let X be a geometrically irreducible smooth projective curve
defined over a perfect field k, and let E be a vector bundle on X. We prove
that E is semistable if and only if there is a vector bundle F on $X$ such that
the cohomologies of E\otimes F vanish. We also give an explicit bound for the
rank of $F$.


title:
Possibility of a new universality class: The anisotropic Heisenberg
  model with dipolar interactions

abstract:
  This paper has been withdrawn by the authors due to a possible inconsistency
in the program code.


title: Monte Carlo generators for top quark physics at the LHC

abstract:
  We review the main features of Monte Carlo generators for top quark
phenomenology and present some results for t-tbar and single-top signals and
backgrounds at the LHC.


title: Gaussian limits for generalized spacings

abstract:
  Nearest neighbor cells in $R^d,d\in\mathbb{N}$, are used to define
coefficients of divergence ($\phi$-divergences) between continuous multivariate
samples. For large sample sizes, such distances are shown to be asymptotically
normal with a variance depending on the underlying point density. In $d=1$,
this extends classical central limit theory for sum functions of spacings. The
general results yield central limit theorems for logarithmic $k$-spacings,
information gain, log-likelihood ratios and the number of pairs of sample
points within a fixed distance of each other.


title:
Chemical similarities between Galactic bulge and local thick disk red
  giant stars

abstract:
  The evolution of the Milky Way bulge and its relationship with the other
Galactic populations is still poorly understood. The bulge has been suggested
to be either a merger-driven classical bulge or the product of a dynamical
instability of the inner disk. To probe the star formation history, the initial
mass function and stellar nucleosynthesis of the bulge, we performed an
elemental abundance analysis of bulge red giant stars. We also completed an
identical study of local thin disk, thick disk and halo giants to establish the
chemical differences and similarities between the various populations.
High-resolution infrared spectra of 19 bulge giants and 49 comparison giants in
the solar neighborhood were acquired with Gemini/Phoenix. All stars have
similar stellar parameters but cover a broad range in metallicity. A standard
1D local thermodynamic equilibrium analysis yielded the abundances of C, N, O
and Fe. A homogeneous and differential analysis of the bulge, halo, thin disk
and thick disk stars ensured that systematic errors were minimized. We confirm
the well-established differences for [O/Fe] (at a given metallicity) between
the local thin and thick disks. For the elements investigated, we find no
chemical distinction between the bulge and the local thick disk, which is in
contrast to previous studies relying on literature values for disk dwarf stars
in the solar neighborhood. Our findings suggest that the bulge and local thick
disk experienced similar, but not necessarily shared, chemical evolution
histories. We argue that their formation timescales, star formation rates and
initial mass functions were similar.


title:
Reaction Brownian Dynamics and the effect of spatial fluctuations on the
  gain of a push-pull network

abstract:
  Brownian Dynamics algorithms are widely used for simulating soft-matter and
biochemical systems. In recent times, their application has been extended to
the simulation of coarse-grained models of cellular networks in simple
organisms. In these models, components move by diffusion, and can react with
one another upon contact. However, when reactions are incorporated into a
Brownian Dynamics algorithm, attention must be paid to avoid violations of the
detailed-balance rule, and therefore introducing systematic errors in the
simulation. We present a Brownian Dynamics algorithm for reaction-diffusion
systems that rigorously obeys detailed balance for equilibrium reactions. By
comparing the simulation results to exact analytical results for a bimolecular
reaction, we show that the algorithm correctly reproduces both equilibrium and
dynamical quantities. We apply our scheme to a ``push-pull'' network in which
two antagonistic enzymes covalently modify a substrate. Our results highlight
that the diffusive behaviour of the reacting species can reduce the gain of the
response curve of this network.


title: A spectroscopic study of a z=1.6 galaxy overdensity with GMASS

abstract:
  The Galaxy Mass Assembly ultra-deep Spectroscopic Survey samples a part of
the CDFS to unprecedented depth. The resulting distribution of 150 z>1.4
redshifts reveals a significant peak at z=1.6, part of a larger overdensity
found at this redshift. The 42 spectroscopic members of this structure, called
Cl 0332-2742, form an overdensity in redshift of a factor 11+/-3 and have a
velocity dispersion of 450 km/s. We derive a total mass for Cl 0332-2742 of
~7x10^14 Msol. The colours of its early-type galaxies are consistent with a
theoretical red sequence of galaxies with stars formed at z=3.0. In addition,
there are more massive, passive and older, but less star forming galaxies in CL
0332-2742 than in the field. We conclude that this structure is a cluster under
assembly at z=1.6.


title:
Spatial variability enhances species fitness in stochastic predator-prey
  interactions

abstract:
  We study the influence of spatially varying reaction rates on a spatial
stochastic two-species Lotka-Volterra lattice model for predator-prey
interactions using two-dimensional Monte Carlo simulations. The effects of this
quenched randomness on population densities, transient oscillations, spatial
correlations, and invasion fronts are investigated. We find that spatial
variability in the predation rate results in more localized activity patches,
which in turn causes a remarkable increase in the asymptotic population
densities of both predators and prey, and accelerated front propagation.


title: Two-photon exchange in dispersion approach

abstract:
  We calculate two-photon exchange amplitude for the elastic electron-proton
scattering in the framework of dispersion relations. The imaginary part of the
amplitude is determined by unitarity. Since in the unitarity relation
intermediate states are on shell, off-shell form factors are not needed for the
calculation. The real part is then evaluated using analytical properties of the
amplitude. The expression for the elastic contribution to the amplitude,
obtained in our approach, differs from the results of traditional calculations
with on-shell form factors. Nevertheless, numerically the difference is minor
for Q^2 up to 6 GeV^2.


title: VLTI monitoring of the dust formation event of the Nova V1280 Sco

abstract:
  We present the first high spatial resolution monitoring of the dust forming
nova V1280 Sco performed with the Very Large Telescope Interferometer (VLTI).
Spectra and visibilities were obtained from the onset of the dust formation 23
days after discovery till day 145, using the instruments AMBER and MIDI. These
interferometric observations are complemented by near-infrared data from the
1.2m Mt. Abu Infrared Observatory, India. The observations are first
interpreted with simple models but more complex models, involving a second
shell, are necessary to explain the data obtained from t=110d after outburst.
This behavior is in accordance with the light curve of V1280 Sco which exhibits
a secondary peak around t=106d, followed by a new steep decline, suggesting a
new dust forming event. Spherical dust shell models generated with the DUSTY
code are also used to investigate the parameters of the main dust shell. Using
uniform disk and Gaussian models, these observations allow us to determine an
apparent linear expansion rate for the dust shell of 0.35 +/- 0.03 mas/day and
the approximate time of ejection of the matter in which dust formed as
t_ejec=10.5+/-7d, i.e. close to the maximum brightness. This information,
combined with the expansion velocity of 500+/-100km/s, implies a distance
estimate of 1.6+/-0.4kpc. The dust mass generated was typically 2-8 10^-9 solar
mass per day. Considering that the dust forming event lasted at least 200-250d,
the mass of the ejected material is likely to have exceeded 10^-4 solar mass.


title:
Frequency metrology on the 4s 2S1/2 - 4p 2P1/2 transition in the calcium
  ion for a comparison with quasar data

abstract:
  High accuracy frequency metrology on the 4s 2S1/2 - 4p 2P1/2 transition in
calcium ions is performed using laser cooled and crystallized ions in a linear
Paul trap. Calibration is performed with a frequency comb laser, resulting in a
transition frequency of f=755222766.2(1.7) MHz. The accuracy presents an
improvement of more than one order of magnitude, and will facilitate a
comparison with quasar data in a search for a possible change of the fine
structure constant on a cosmological time scale.


title:
Experimental investigation of a control scheme for a zero-detuning
  resonant sideband extraction interferometer for next-generation
  gravitational-wave detectors

abstract:
  Some next-generation gravitational-wave detectors, such as the American
Advanced LIGO project and the Japanese LCGT project, plan to use power recycled
resonant sideband extraction (RSE) interferometers for their interferometer's
optical configuration. A power recycled zero-detuning (PRZD) RSE
interferometer, which is the default design for LCGT, has five main length
degrees of freedom that need to be controlled in order to operate a
gravitational-wave detector. This task is expected to be very challenging
because of the complexity of optical configuration. A new control scheme for a
PRZD RSE interferometer has been developed and tested with a prototype
interferometer. The PRZD RSE interferometer was successfully locked with the
control scheme. It is the first experimental demonstration of a PRZD RSE
interferometer with suspended test masses. The result serves as an important
step for the operation of LCGT.


title: Thermal description of hadron production in e+e- collisions revisited

abstract:
  We present a comprehensive analysis of hadron production in e+e- collisions
at different center-of-mass energies in the framework of the statistical model
of the hadron resonance gas. The model is formulated in the canonical ensemble
with exact conservation of all relevant quantum numbers. The parameters of the
underlying model were determined using a fit to the average multiplicities of
the latest measurements at $\sqrt{s}$ = 10, 29-35, 91 and 130-200 GeV. The
results demonstrate that, within the accuracy of the experiments, none of the
data sets is satisfactorily described with this approach, calling into question
the notion that particle production in e+e- collisions is thermal in origin.


title: Low-threshold bistability of slow light in photonic-crystal waveguides

abstract:
  We analyze the resonant transmission of light through a photonic-crystal
waveguide side coupled to a Kerr nonlinear cavity, and demonstrate how to
design the structure geometry for achieving bistability and all-optical
switching at ultra-low powers in the slow-light regime. We show that the
resonance quality factor in such structures scales inversely proportional to
the group velocity of light at the resonant frequency and thus grows
indefinitely in the slow-light regime. Accordingly, the power threshold
required for all-optical switching in such structures scales as a square of the
group velocity, rapidly vanishing in the slow-light regime.


title: Warming the early Earth - CO2 reconsidered

abstract:
  Despite a fainter Sun, the surface of the early Earth was mostly ice-free.
Proposed solutions to this so-called "faint young Sun problem" have usually
involved higher amounts of greenhouse gases than present in the modern-day
atmosphere. However, geological evidence seemed to indicate that the
atmospheric CO2 concentrations during the Archaean and Proterozoic were far too
low to keep the surface from freezing. With a radiative-convective model
including new, updated thermal absorption coefficients, we found that the
amount of CO2 necessary to obtain 273 K at the surface is reduced up to an
order of magnitude compared to previous studies. For the late Archaean and
early Proterozoic period of the Earth, we calculate that CO2 partial pressures
of only about 2.9 mb are required to keep its surface from freezing which is
compatible with the amount inferred from sediment studies. This conclusion was
not significantly changed when we varied model parameters such as relative
humidity or surface albedo, obtaining CO2 partial pressures for the late
Archaean between 1.5 and 5.5 mb. Thus, the contradiction between sediment data
and model results disappears for the late Archaean and early Proterozoic.


title: Optimization of operational aircraft parameters Reducing Noise Emission

abstract:
  The objective of this paper is to develop a model and a minimization method
to provide flight path optimums reducing aircraft noise in the vicinity of
airports. Optimization algorithm has solved a complex optimal control problem,
and generates flight paths minimizing aircraft noise levels. Operational and
safety constraints have been considered and their limits satisfied. Results are
here presented and discussed.


title: The Discovery of Water Maser Emission from Eight Nearby Galaxies

abstract:
  Using the Green Bank Telescope, we conducted a ``snapshot'' survey for water
maser emission toward the nuclei of 611 galaxies and detected eight new
sources. The sample consisted of nearby (v < 5000 km/s) and luminous (M_B <
-19.5) galaxies, some with known nuclear activity but most not previously known
to host AGNs. Our detections include both megamasers associated with AGNs and
relatively low luminosity masers probably associated with star formation. The
detection in UGC 3789 is particularly intriguing because the spectrum shows
both systemic and high-velocity lines indicative of emission from an AGN
accretion disk seen edge-on. Based on six months of monitoring, we detected
accelerations among the systemic features ranging from 2 to 8 km/s/yr, the
larger values belonging to the most redshifted systemic components.
High-velocity maser lines in UGC 3789 show no detectable drift over the same
period. Although UGC 3789 was not known to be an AGN prior to this survey, the
presence of a disk maser is strong evidence for nuclear activity, and an
optical spectrum obtained later has confirmed it. With follow up observations,
it may be possible to measure a geometric distance to UGC 3789.


title:
Global continuous solutions to diagonalizable hyperbolic systems with
  large and monotone data

abstract:
  In this paper, we study diagonalizable hyperbolic systems in one space
dimension. Based on a new gradient entropy estimate, we prove the global
existence of a continuous solution, for large and nondecreasing initial data.
Moreover, we show in particular cases some uniqueness results. We also remark
that these results cover the case of systems which are hyperbolic but not
strictly hyperbolic. Physically, this kind of diagonalizable hyperbolic systems
appears naturally in the modelling of the dynamics of dislocation densities.


title: Sketching and Streaming Entropy via Approximation Theory

abstract:
  We conclude a sequence of work by giving near-optimal sketching and streaming
algorithms for estimating Shannon entropy in the most general streaming model,
with arbitrary insertions and deletions. This improves on prior results that
obtain suboptimal space bounds in the general model, and near-optimal bounds in
the insertion-only model without sketching. Our high-level approach is simple:
we give algorithms to estimate Renyi and Tsallis entropy, and use them to
extrapolate an estimate of Shannon entropy. The accuracy of our estimates is
proven using approximation theory arguments and extremal properties of
Chebyshev polynomials, a technique which may be useful for other problems. Our
work also yields the best-known and near-optimal additive approximations for
entropy, and hence also for conditional entropy and mutual information.


title: The spectroscopic orbit and the geometry of R Aqr

abstract:
  R Aqr is one of the closest symbiotic binaries and the only D-type system
with radial velocity data suitable for orbital parameters estimation. The aims
of our study are to derive a reliable spectroscopic orbit of the Mira
component, and to establish connections between the orbital motion and other
phenomena shown by R Aqr. We reanalize velocity data recently published by
McIntosh & Rustan complemented by additional velocities. We find an eccentric
orbit (e=0.25) with a period 43.6 yr. This solution is in agreement with a
resolved VLA observation of this system. We demonstrate that the last 1974-1981
increase of extinction towards the Mira occured during its superior
spectroscopic conjunction, and can be due to obscuration by a neutral material
in the accreting stream. We also show that jet ejection is not connected with
the orbital position.


title:
Coupled-resonator-induced reflection in photonic-crystal waveguide
  structures

abstract:
  We study the resonant transmission of light in a coupled-resonator optical
waveguide interacting with two nearly identical side cavities. We reveal and
describe a novel effect of the coupled-resonator-induced reflection (CRIR)
characterized by a very high and easily tunable quality factor of the
reflection line, for the case of the inter-site coupling between the cavities
and the waveguide. This effect differs sharply from the
coupled-resonator-induced transparency (CRIT) -- an all-optical analogue of the
electromagnetically-induced transparency -- which has recently been studied
theoretically and observed experimentally for the structures based on
micro-ring resonators and photonic crystal cavities. Both CRIR and CRIT effects
have the same physical origin which can be attributed to the Fano-Feshbach
resonances in the systems exhibiting more than one resonance. We discuss the
applicability of the novel CRIR effect to the control of the slow-light
propagation and low-threshold all-optical switching.


title: The first moment of quadratic Dirichlet L-functions

abstract:
  We obtain an asymptotic formula for the smoothly weighted first moment of
primitive quadratic Dirichlet L-functions at the central point, with an error
term that is "square-root" of the main term. Our approach uses a recursive
technique that feeds the result back into itself, successively improving the
error term.


title:
Improved Cosmological Constraints from New, Old and Combined Supernova
  Datasets

abstract:
  We present a new compilation of Type Ia supernovae (SNe Ia), a new dataset of
low-redshift nearby-Hubble-flow SNe and new analysis procedures to work with
these heterogeneous compilations. This ``Union'' compilation of 414 SN Ia,
which reduces to 307 SNe after selection cuts, includes the recent large
samples of SNe Ia from the Supernova Legacy Survey and ESSENCE Survey, the
older datasets, as well as the recently extended dataset of distant supernovae
observed with HST. A single, consistent and blind analysis procedure is used
for all the various SN Ia subsamples, and a new procedure is implemented that
consistently weights the heterogeneous data sets and rejects outliers. We
present the latest results from this Union compilation and discuss the
cosmological constraints from this new compilation and its combination with
other cosmological measurements (CMB and BAO). The constraint we obtain from
supernovae on the dark energy density is $\Omega_\Lambda=
0.713^{+0.027}_{-0.029} (stat)}^{+0.036}_{-0.039} (sys)}$, for a flat, LCDM
Universe. Assuming a constant equation of state parameter, $w$, the combined
constraints from SNe, BAO and CMB give
$w=-0.969^{+0.059}_{-0.063}(stat)^{+0.063}_{-0.066} (sys)$. While our results
are consistent with a cosmological constant, we obtain only relatively weak
constraints on a $w$ that varies with redshift. In particular, the current SN
data do not yet significantly constrain $w$ at $z>1$. With the addition of our
new nearby Hubble-flow SNe Ia, these resulting cosmological constraints are
currently the tightest available.


title: The most massive progenitors of neutron stars: CXO J164710.2-455216

abstract:
  The evolution leading to the formation of a neutron star in the very young
Westerlund 1 star cluster is investigated. The turnoff mass has been estimated
to be 35 Msun, indicating a cluster age ~ 3-5 Myr. The brightest X-ray source
in the cluster, CXO J164710.2-455216, is a slowly spinning (10 s) single
neutron star and potentially a magnetar. Since this source was argued to be a
member of the cluster, the neutron star progenitor must have been very massive
(M_zams > 40 Msun) as noted by Muno et al. (2006). Since such massive stars are
generally believed to form black holes (rather than neutron stars), the
existence of this object poses a challenge for understanding massive star
evolution. We point out while single star progenitors below M_zams < 20 Msun
form neutron stars, binary evolution completely changes the progenitor mass
range. In particular, we demonstrate that mass loss in Roche lobe overflow
enables stars as massive as 50-80 Msun, under favorable conditions, to form
neutron stars. If the very high observed binary fraction of massive stars in
Westerlund 1 (> 70 percent) is considered, it is natural that CXO
J164710.2-455216 was formed in a binary which was disrupted in a supernova
explosion such that it is now found as a single neutron star. Hence, the
existence of a neutron star in a given stellar population does not necessarily
place stringent constraints on progenitor mass when binary interactions are
considered. It is concluded that the existence of a neutron star in Westerlund
1 cluster is fully consistent with the generally accepted framework of stellar
evolution.


title:
Search for a stochastic gravitational-wave signal in the second round of
  the Mock LISA Data Challenges

abstract:
  The analysis method currently proposed to search for isotropic stochastic
radiation of primordial or astrophysical origin with the Laser Interferometer
Space Antenna (LISA) relies on the combined use of two LISA channels, one of
which is insensitive to gravitational waves, such as the symmetrised Sagnac.
For this method to work, it is essential to know how the instrumental noise
power in the two channels are related to one another; however, no quantitative
estimates of this key information are available to date. The purpose of our
study is to assess the performance of the symmetrised Sagnac method for
different levels of prior information regarding the instrumental noise. We
develop a general approach in the framework of Bayesian inference and an
end-to-end analysis algorithm based on Markov Chain Monte Carlo methods to
compute the posterior probability density functions of the relevant model
parameters. We apply this method to data released as part of the second round
of the Mock LISA Data Challenges. For the selected (and somewhat idealised)
cases considered here, we find that a prior uncertainty of a factor ~2 in the
ratio between the power of the instrumental noise contributions in the two
channels allows for the detection of isotropic stochastic radiation. More
importantly, we provide a framework for more realistic studies of LISA's
performance and development of analysis techniques in the context of searches
for stochastic signals.


title: The Cops and Robber game on graphs with forbidden (induced) subgraphs

abstract:
  The two-player, complete information game of Cops and Robber is played on
undirected finite graphs. A number of cops and one robber are positioned on
vertices and take turns in sliding along edges. The cops win if, after a move,
a cop and the robber are on the same vertex. The minimum number of cops needed
to catch the robber on a graph is called the cop number of that graph.
  In this paper, we study the cop number in the classes of graphs defined by
forbidding one or more graphs as either subgraphs or induced subgraphs. In the
case of a single forbidden graph we completely characterize (for both
relations) the graphs which force bounded cop number. En passant, we bound the
cop number in terms of tree-width.


title: Higgs boson searches at LEP

abstract:
  In this paper we report on the legacy of Higgs boson searches at LEP.
Specifically, the results of the statistical combination of the searches
carried out by the ALEPH, DELPHI, L3 and OPAL experiments are presented. In the
search for the Standard Model (SM) Higgs boson, a signal with mh<114.4 GeV/c^2
has been excluded at the 95% confidence level (CL) or higher. The LEP
collaborations also carried out extensive searches for Higgs particles
predicted by many scenarios beyond the Standard Model. Here we can only report
on a very small fraction of these searches and refer the reader to the complete
list of LEP-combined search results.


title: Status of the Standard Model at the LHC Start

abstract:
  I present a concise review of where we stand in particle physics today.
First, I will discuss QCD, then the electroweak sector and finally the
motivations and the avenues for new physics beyond the Standard Model.


title: Equation of state and more from lattice regularized QCD

abstract:
  We present results from a calculation of the QCD equation of state with two
light (up, down) and one heavier (strange) quark mass performed on lattices
with three different values of the lattice cut-off. We show that also on the
finest lattice analyzed by us observables sensitive to deconfinement and chiral
symmetry restoration, respectively, vary most rapidly in the same temperature
regime.


title:
One-loop phi-MHV amplitudes using the unitarity bootstrap: the general
  helicity case

abstract:
  We consider a Higgs boson coupled to gluons via the five-dimensional
effective operator H tr G_{\mu\nu}G^{\mu\nu}. We treat H as the real part of a
complex field phi that couples to the selfdual gluon field strengths and
compute the one-loop corrections to the phi-MHV amplitudes involving phi, two
negative helicity gluons and an arbitrary number of positive helicity gluons.
Our results generalise earlier work where the two negative helicity gluons were
constrained to be colour adjacent. We use four-dimensional unitarity to
construct the cut-containing contributions and the recently developed recursion
relations to obtain the rational contribution for an arbitrary number of
external gluons. We solve the recursion relations and give explicit results for
up to four external gluons. These amplitudes are relevant for Higgs plus jet
production via gluon fusion in the limit where the top quark mass is large
compared to all other scales in the problem.


title: On Computing the Shadows and Slices of Polytopes

abstract:
  We study the complexity of computing the projection of an arbitrary
$d$-polytope along $k$ orthogonal vectors for various input and output forms.
We show that if $d$ and $k$ are part of the input (i.e. not a constant) and we
are interested in output-sensitive algorithms, then in most forms the problem
is equivalent to enumerating vertices of polytopes, except in two where it is
NP-hard. In two other forms the problem is trivial. We also review the
complexity of computing projections when the projection directions are in some
sense non-degenerate. For full-dimensional polytopes containing origin in the
interior, projection is an operation dual to intersecting the polytope with a
suitable linear subspace and so the results in this paper can be dualized by
interchanging vertices with facets and projection with intersection. To compare
the complexity of projection and vertex enumeration, we define new complexity
classes based on the complexity of Vertex Enumeration.


title:
Observation of narrow Autler-Townes components in the resonant response
  of a dense atomic gas

abstract:
  We have experimentally studied the reflection of a weak probe beam from a
dense atomic potassium vapor in the presence of a strong laser field tuned to
the atomic resonance transition. We have observed an Autler-Townes doublet
under hitherto unexplored conditions, namely that the Rabi frequency induced by
the strong laser field is much smaller than the self-broadened width of the
resonance transition of the unexcited vapor. We attribute our observation to a
reduction of the atomic decoherence by the strong drive field. We present a
theoretical model of nonlinear processes in a dense atomic gas to explain the
observed results.


title: Adaptive networks of trading agents

abstract:
  Multi-agent models have been used in many contexts to study generic
collective behavior. Similarly, complex networks have become very popular
because of the diversity of growth rules giving rise to scale-free behavior.
Here we study adaptive networks where the agents trade ``wealth'' when they are
linked together while links can appear and disappear according to the wealth of
the corresponding agents; thus the agents influence the network dynamics and
vice-versa. Our framework generalizes a multi-agent model of Bouchand and
Mezard, and leads to a steady state with fluctuating connectivities. The system
spontaneously self-organizes into a critical state where the wealth
distribution has a fat tail and the network is scale-free; in addition, network
heterogeneities lead to enhanced wealth condensation.


title: The Other Group of as Galois Extension

abstract:
  Let $k\subseteq K$ be a finite Galois extension of fields with Galois group
$G$. Let $\mathscr{G}$ be the automorphism $k$-group scheme of $K$. We
construct a canonical $k$-subgroup scheme $\underline{G}\subset\mathscr{G}$
with the property that $Spec_k(K)$ is a $k$-torsor for $\underline{G}$.
$\underline{G}$ is a constant $k$-group if and only if $G$ is abelian, in which
case $G=\underline{G}$.


title: Tiling tripartite graphs with 3-colorable graphs

abstract:
  For a fixed integer h>=1, let G be a tripartite graph with N vertices in each
vertex class, N divisible by 6h, such that every vertex is adjacent to at least
2N/3+h-1 vertices in each of the other classes. We show that if N is
sufficiently large, then G can be tiled perfectly by copies of K_{h,h,h}. This
extends the work in [19] and also gives a sufficient condition for tiling by
any (fixed) 3-colorable graph. Furthermore, we show that this minimum-degree
condition is best possible and provide very tight bounds when N is divisible by
h but not by 6h.


title: Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way

abstract:
  New 21cm HI observations made with the Green Bank Telescope show that the
high-velocity cloud known as Smith's Cloud has a striking cometary appearance
and many indications of interaction with the Galactic ISM. The velocities of
interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the
distance derived from other methods. The Cloud is >3 x 1 kpc in size and its
tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc
below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its
leading section has a total space velocity near 300 km/s, is moving toward the
Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the
Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr.
Smith's Cloud may be an example of the accretion of gas by the Milky Way needed
to explain certain persistent anomalies in Galactic chemical evolution.


title: Resolving the Formation of Protogalaxies

abstract:
  Cosmic structure originated from minute density perturbations in an almost
homogeneous universe. The first stars are believed to be very massive and
luminous, providing the first ionizing radiation and heavy elements to the
universe and forming 100 million years after the Big Bang. The impact from
primordial stellar radiation is far reaching and affects subsequent star and
galaxy formation. In this thesis, we present results from adaptive mesh
refinement calculations of the formation of the first galaxies. We gradually
introduce important physical processes, such as molecular hydrogen cooling and
stellar feedback, to base models that only consider atomic hydrogen and helium
cooling. In these base models, we find that gas in dark matter halos with
masses ~10^8 solar masses centrally collapse before multiple fragmentation
occurs in a global disc. We then investigate the importance of molecular
hydrogen cooling in early structure formation in the presence of a soft
ultraviolet radiation background. We find that molecular hydrogen plays an
important role in star formation in halos well below a virial temperature of
10,000 K even in the most extreme assumptions of negative radiative feedback.
We also present results from the first radiation hydrodynamics calculations of
early dwarf galaxy formation. We develop a novel technique, adaptive ray
tracing, to accurately transport radiation from primordial stars. We find
primordial stellar feedback alters the landscape of early galaxy formation in
that its angular momentum is increased and baryon fractions are decreased. We
also describe the metal enrichment of the intergalactic medium and early dwarf
galaxies. Finally we explore cosmological reionization by these massive,
metal-free stars and its effects on star formation in early galaxies.


title: Signatures of a hidden cosmic microwave background

abstract:
  If there is a hidden photon -- i.e. a light abelian gauge boson in the hidden
sector -- its kinetic mixing with the standard photon can produce a hidden
cosmic microwave background (hCMB). For meV masses, resonant photon-hidden
photon oscillations happen after nucleosynthesis (BBN) but before CMB
decoupling, increasing the effective number of neutrinos but also the baryon to
photon ratio. The current agreement between BBN and CMB data provides new
constraints on the kinetic mixing. However, if one includes Lyman-alpha data,
an effective number of neutrinos higher than 3 is preferred. It is tempting to
interpret this effect in terms of the hCMB. Interestingly, the required
parameters will be tested in the near future by laboratory experiments.


title: Predictions for the LHC: an Overview

abstract:
  I present an overview of predictions for the heavy ion program at the Large
Hadron Collider. It is mainly based on the material presented during the
workshop 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held in
the frame of the CERN Theory Institute from May 14th to June 10th 2007.
Predictions on both bulk properties and hard probes are reviewed.


title: Supergravity on an Atiyah-Hitchin Base

abstract:
  We construct solutions to five dimensional minimal supergravity using an
Atiyah-Hitchin base space. In examining the structure of solutions we show that
they generically contain a singularity either on the Atiyah-Hitchin bolt or at
larger radius where there is a singular solitonic boundary. However for most
points in parameter space the solution exhibits a velocity of light surface
(analogous to what appears in a Goedel space-time) that shields the
singularity. For these solutions, all closed time-like curves are causally
disconnected from the rest of the space-time in that they exist within the
velocity of light surface, which null geodesics are unable to cross. The
singularities in these solutions are thus found to be hidden behind the
velocity of light surface and so are not naked despite the lack of an event
horizon. Outside of this surface the space-time is geodesically complete,
asymptotically flat and can be arranged so as not to contain closed time-like
curves at infinity. The rest of parameter space simply yields solutions with
naked singularities.


title: On the visual appearance of relativistic objects

abstract:
  A formula for the apparent rotation of a relativistically moving object has
been known for some time, but it seems not to have been realized that this
formula has a very pretty interpretation in terms of formal group laws.
  Version 2 contains a few rather small additions.


title:
Discrete Quantum Gravity: I. Zonal spherical functions of the
  representationsof the SO(4,R) group with respect to the SU(2) subgroup and
  their application to the Barrett-Crane model

abstract:
  Starting from the defining transformations of complex matrices for the
$SO(4,R)$ group, we construct the fundamental representation and the tensor and
spinor representations of the group $SO(4,R)$. Given the commutation relations
for the corresponding algebra, the unitary representations of the group in
terms of the generalized Euler angles are constructed. The crucial step for the
Barrett-Crane model in Quantum Gravity is the description of the amplitude for
the quantum 4-simplex that is used in the state sum partition function. We
obtain the zonal spherical functions for the construction of the SO(4,R)
invariant weight and associate them to the triangular faces of the 4-simplices.


title:
Discrete Quantum Gravity: II. Simplicial complexes, irreps of SL(2,C),
  and a Lorentz invariant weight in a state sum model

abstract:
  In part I of [1] we have developed the tensor and spin representation of
SO(4) in order to apply it to the simplicial decomposition of the Barrett-Crane
model. We attach to each face of a triangle the spherical function constructed
from the Dolginov-Biedenharn function.
  In part II we apply the same technique to the Lorentz invariant state sum
model. We need three new ingredients: the classification of the edges and the
corresponding subspaces that arises in the simplicial decomposition, the irreps
of SL(2,C) and its isomorphism to the bivectors appearing in the 4-simplices,
the need of a zonal spherical function from the intertwining condition of the
tensor product for the simple representations attached to the faces of the
simplicial decomposition.


title:
Spatial and Temporal Variations in Interstellar Absorption toward HD
  72127AB

abstract:
  New optical spectra of Ca II and Na I toward HD 72127AB provide additional
evidence for both spatial and temporal variations in the complex interstellar
absorption along the two sight lines; archival UV spectra yield information on
the abundances, depletions, and physical conditions in the gas toward HD
72127A. Similarities in the strengths of various tracers of interstellar
material in the two lines of sight suggest that the total hydrogen column
densities [N(H) ~ 2.5 x 10^{20} cm^{-2}] and the depletions and ionization in
the main components at low LSR velocities also are similar. Toward HD 72127A,
the main components are relatively cool (T < 900 K), but with depletions
resembling those found in warm, diffuse disc clouds; the generally weaker
components at higher velocities have much milder depletions, more like those
found in halo clouds. Several trace neutral species -- Ca I, Cr I, and Fe I --
are much stronger toward HD 72127B, however. The column density of Cr I, for
example, is about 30 times the value determined toward zeta Oph (the only
previous detection of that species in the ISM). Dielectronic recombination in
warmer gas (T > 5000 K) may be largely responsible for the enhanced abundances
of those trace neutral species toward HD 72127B. If the main components toward
HD 72127AB are associated with material in the Vela SNR, the differences in
abundances and physical conditions occur on scales of about 1100 AU.


title: Cohomology Jumping Loci and Relative Malcev Completion

abstract:
  Two standard invariants used to study the fundamental group G of the
complement X of a hyperplane arrangement are the Malcev completion of G and the
cohomology groups of X with coefficients in rank one local systems. In this
paper, we develop a tool that unifies these two approaches. This tool is the
Malcev completion S_p of G relative to a homomorphism p from G into (C^*)^N.
This is a prosolvable group that is tightly controlled by the cohomology groups
of X with coefficients in rank one local systems. The prounipotent radical U_p
of the relative completion S_p corresponds to a pronilpotent Lie algebra u_p.
We provide an example of a hyperplane complement X for which this algebra is
not quadratically presented. In addition, we show that if X is a hyperplane
complement and Y is a subtorus of the character torus, then S_p is
combinatorially determined for general p in Y. Finally, we show that the
relative completion S_p is generally constant over subvarieties of the
character torus.


title: Locally constant n-operads as higher braided operads

abstract:
  We introduce a category of locally constant $n$-operads which can be
considered as the category of higher braided operads. For $n=1,2,\infty$ the
homotopy category of locally constant $n$-operads is equivalent to the homotopy
category of classical nonsymmetric, braided and symmetric operads
correspondingly.


title:
Spin Fluctuations, Interband Coupling, and Unconventional Pairing in
  Iron-based Superconductors

abstract:
  Based on an effective two-band model and using the fluctuation-exchange
(FLEX) approach, we explore spin fluctuations and unconventional
superconducting pairing in Fe-based layer superconductors. It is elaborated
that one type of interband antiferromagnetic (AF) spin fluctuation stems from
the interband Coulomb repulsion, while the other type of intraband AF spin
fluctuation originates from the intraband Coulomb repulsion. Due to the
Fermi-surface topology, a spin-singlet extended s-wave superconducting state is
more favorable than the nodal $d_{XY}$-wave state if the interband AF spin
fluctuation is more significant than the intraband one, otherwise vice versa.
It is also revealed that the effective interband coupling plays an important
role in the intraband pairings, which is a distinct feature of the present
two-band system.


title: Effects of decoherence and errors on Bell-inequality violation

abstract:
  We study optimal conditions for violation of the Clauser-Horne-Shimony-Holt
form of the Bell inequality in the presence of decoherence and measurement
errors. We obtain all detector configurations providing the maximal Bell
inequality violation for a general (pure or mixed) state. We consider local
decoherence which includes energy relaxation at the zero temperature and
arbitrary dephasing. Conditions for the maximal Bell-inequality violation in
the presence of decoherence are analyzed both analytically and numerically for
the general case and for a number of important special cases. Combined effects
of measurement errors and decoherence are also discussed.


title:
Enhanced production of direct photons in Au+Au collisions at
  sqrt(s_NN)=200 GeV and implications for the initial temperature

abstract:
  The production of low mass e+e- pairs for m_{e+e-} < 300 MeV/c^2 and 1 < p_T
<5 GeV/c is measured in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV.
Enhanced yield above hadronic sources is observed. Treating the excess as
internal conversions, the invariant yield of direct photons is deduced. In
central Au+Au collisions, the excess of direct photon yield over p+p is
exponential in transverse momentum, with inverse slope T = 221 +/- 19 (stat)
+/- 19 (syst) MeV. Hydrodynamical models with initial temperatures ranging from
300--600 MeV at times of ~ 0.6 - 0.15 fm/c after the collision are in
qualitative agreement with the data. Lattice QCD predicts a phase transition to
quark gluon plasma at ~ 170 MeV.


title: Quantum effects in classical systems having complex energy

abstract:
  On the basis of extensive numerical studies it is argued that there are
strong analogies between the probabilistic behavior of quantum systems defined
by Hermitian Hamiltonians and the deterministic behavior of classical
mechanical systems extended into the complex domain. Three models are examined:
the quartic double-well potential $V(x)=x^4-5x^2$, the cubic potential
$V(x)=frac{1}{2}x^2-gx^3$, and the periodic potential $V(x)=-\cos x$. For the
quartic potential a wave packet that is initially localized in one side of the
double-well can tunnel to the other side. Complex solutions to the classical
equations of motion exhibit a remarkably analogous behavior. Furthermore,
classical solutions come in two varieties, which resemble the even-parity and
odd-parity quantum-mechanical bound states. For the cubic potential, a quantum
wave packet that is initially in the quadratic portion of the potential near
the origin will tunnel through the barrier and give rise to a probability
current that flows out to infinity. The complex solutions to the corresponding
classical equations of motion exhibit strongly analogous behavior. For the
periodic potential a quantum particle whose energy lies between -1 and 1 can
tunnel repeatedly between adjacent classically allowed regions and thus execute
a localized random walk as it hops from region to region. Furthermore, if the
energy of the quantum particle lies in a conduction band, then the particle
delocalizes and drifts freely through the periodic potential. A classical
particle having complex energy executes a qualitatively analogous local random
walk, and there exists a narrow energy band for which the classical particle
becomes delocalized and moves freely through the potential.


title: Mirabolic Langlands duality and the quantum Calogero-Moser system

abstract:
  We give a generic spectral decomposition of the derived category of twisted
D-modules on a moduli stack of mirabolic vector bundles on a curve X in
characteristic p: that is, we construct an equivalence with the derived
category of quasi-coherent sheaves on a moduli stack of mirabolic local systems
on X. This equivalence may be understood as a tamely ramified form of the
geometric Langlands equivalence. When X has genus 1, this equivalence
generically solves (in the sense of noncommutative geometry) the quantum
Calogero-Moser system.


title:
Comment on Evolution of the electronic excitation spectrum with strongly
  diminishing hole density in superconducting Bi-2212 (J. W. Alldredge et al.,
  Nature Phys. 4, 319 (2008))

abstract:
  In a recent article, Alldredge et al. reported tunnelling data obtained at T
= 4.2 K by STM in Bi-2212 having different doping levels, p, and a new way to
fit the measured differential conductances, g(V), which are linearly
proportional to the local density of states of quasiparticle excitations at the
surface, N(E). The main point of the fitting procedure is to use an
energy-dependent inelastic scattering rate, G = aE (a is a constant). They
argue that by using an equation of the d-wave BCS density of states
(Bardeen-Cooper-Schrieffer) modified by Dynes et al. with G = aE, they were
able to fit any conductance obtained in Bi-2212 with a doping level between 0.1
and 0.22. In addition, they discuss a new energy scale Delta_0(p) similar to
that obtained in Raman measurements. Unfortunately, the paper is misleading.


title: Detecting dark matter-dark energy coupling with the halo mass function

abstract:
  We use high-resolution simulations of large-scale structure formation to
analyze the effects of interacting dark matter and dark energy on the evolution
of the halo mass function. Using a chi-square likelihood analysis, we find
significant differences in the mass function between models of coupled dark
matter-dark energy and standard concordance cosmology Lambda-CDM out to
redshift z=1.5. We also find a preliminary indication that the Dark Energy
Survey should be able to distinguish these models from Lambda-CDM within its
mass and redshift contraints. While we can distinguish the effects of these
models from Lambda-CDM cosmologies with different fundamental parameters, DES
will require independent measurements of sigma-8 to confirm these effects.


title:
Precision measurement of the branching ratio in the 6P3/2 decay of BaII
  with a single trapped ion

abstract:
  We present a measurement of the branching ratios from the 6P3/2 state of BaII
into all dipoleallowed decay channels (6S1/2, 5D3/2 and 5D5/2). Measurements
were performed on single 138Ba+ ions in a linear Paul trap with a
frequency-doubled mode-locked Ti:Sapphire laser resonant with the 6S1/2->6P3/2
transition at 455 nm by detection of electron shelving into the dark 5D5/2
state. By driving a pi Rabi rotation with a single femtosecond pulse, a
absolute measurement of the branching ratio to 5D5/2 state was performed.
Combined with a measurement of the relative decay rates into 5D3/2 and 5D5/2
states performed with long trains of highly attenuated 455 nm pulses, it
allowed the extraction of the absolute ratios of the other two decays. Relative
strengths normalized to unity are found to be 0.756+/-0.046, 0.0290+/-0.0015
and 0.215+/-0.0064 for 6S1/2, 5D3/2 and 5D5/2 respectively. This approximately
constitutes a threefold improvement over the best previous measurements and is
a sufficient level of precision to compare to calculated values for dipole
matrix elements.


title: A Model of Electrons, Photons and the Ether

abstract:
  This is an attempt to construct a classical microscopic model of the electron
which underlies quantum mechanics. An electron is modeled, not as a point
particle, but as the end of an electromagnetic string, a line of flux. These
lines stretch across cosmic distances, but are almost unobservable because they
condense into pairs--which form the ether. Photons are modeled to propagate on
these line pairs, which act effectively as wave guides. These line pairs are
also responsible for the force of gravity--which is electromagnetic in
character.


title:
The Detection of a Red Sequence of Massive Field Galaxies at z~2.3 and
  its Evolution to z~0

abstract:
  The existence of massive galaxies with strongly suppressed star formation at
z~2.3, identified in a previous paper, suggests that a red sequence may already
be in place beyond z=2. In order to test this hypothesis, we study the
rest-frame U-B color distribution of massive galaxies at 2<z<3. The sample is
drawn from our near-infrared spectroscopic survey for massive galaxies. The
color distribution shows a statistically significant (>3 sigma) red sequence,
which hosts ~60% of the stellar mass at the high-mass end. The red-sequence
galaxies have little or no ongoing star formation, as inferred from both
emission-line diagnostics and stellar continuum shapes. Their strong Balmer
breaks and their location in the rest-frame U-B, B-V plane indicate that they
are in a post-starburst phase, with typical ages of ~0.5-1.0 Gyr. In order to
study the evolution of the red sequence, we compare our sample with
spectroscopic massive galaxy samples at 0.02<z<0.045 and 0.6<z<1.0. The
rest-frame U-B color reddens by ~0.25 mag from z~2.3 to the present at a given
mass. Over the same redshift interval, the number and stellar mass density on
the high-mass end (>10^11 Msol) of the red sequence grow by factors of ~8 and
~6, respectively. We explore simple models to explain the observed evolution.
Passive evolution models predict too strong d(U-B), and produce z~0 galaxies
that are too red. More complicated models that include aging, galaxy
transformations, and red mergers can explain both the number density and color
evolution of the massive end of the red sequence between z~2.3 and the present.


title: Dissipative Pulsar Magnetosphere

abstract:
  Dissipative axisymmetric pulsar magnetosphere is calculated by a direct
numerical simulation of the Strong-Field Electrodynamics equations. The
magnetic separatrix disappears, it is replaced by a region of enhanced
dissipation. With a better numerical scheme, one should be able to calculate
the bolometric lightcurves for a given conductivity.


title:
Star formation in galaxies falling into clusters along
  supercluster-scale filaments

abstract:
  With the help of a statistical parameter derived from optical spectra, we
show that the current star formation rate of a galaxy, falling into a cluster
along a supercluster filament, is likely to undergo a sudden enhancement before
the galaxy reaches the virial radius of the cluster. From a sample of 52
supercluster-scale filaments of galaxies joining a pair of rich clusters of
galaxies within the two-degree Field Redshift Survey region, we find a
significant enhancement of star formation, within a narrow range between 2-3
h/70 Mpc of the centre of the cluster into which the galaxy is falling. This
burst of star formation is almost exclusively seen in the fainter dwarf
galaxies (M_B> -20). The relative position of the peak does not depend on
whether the galaxy is a member of a group or not, but non-group galaxies have
on average a higher rate of star formation immediately before falling into a
cluster. From the various trends, we conclude that the predominant process
responsible for this rapid burst is the close interaction with other galaxies
falling into the cluster along the same filament, if the interaction occurs
before the gas reservoir of the galaxy gets stripped off due to the interaction
with the intracluster medium.


title:
Molecular motion in cell membranes: analytic study of fence-hindered
  random walks

abstract:
  A theoretical calculation is presented to describe the confined motion of
transmembrane molecules in cell membranes. The study is analytic, based on
Master equations for the probability of the molecules moving as random walkers,
and leads to explicit usable solutions including expressions for the molecular
mean square displacement and effective diffusion constants. One outcome is a
detailed understanding of the dependence of the time variation of the mean
square displacement on the initial placement of the molecule within the
confined region. How to use the calculations is illustrated by extracting
(confinement) compartment sizes from experimentally reported published
observations from single particle tracking experiments on the diffusion of
gold-tagged G-protein coupled mu-opioid receptors in the normal rat kidney cell
membrane, and by further comparing the analytical results to observations on
the diffusion of phospholipids, also in normal rat kidney cells.


title:
Effects of disorder in location and size of fence barriers on molecular
  motion in cell membranes

abstract:
  The effect of disorder in the energetic heights and in the physical locations
of fence barriers encountered by transmembrane molecules such as proteins and
lipids in their motion in cell membranes is studied theoretically. The
investigation takes as its starting point a recent analysis of a periodic
system with constant distances between barriers and constant values of barrier
heights, and employs effective medium theory to treat the disorder. The
calculations make possible, in principle, the extraction of confinement
parameters such as mean compartment sizes and mean intercompartmental
transition rates from experimentally reported published observations. The
analysis should be helpful both as an unusual application of effective medium
theory and as an investigation of observed molecular movements in cell
membranes.


title: Constructing Generalized Synchronization Manifolds by Manifold Equation

abstract:
  Full understanding of synchronous behavior in coupled dynamical systems
beyond the identical case requires an explicit construction of the generalized
synchronization manifold, whether we wish to compare the systems, or to
understand their stability. Nonetheless, while synchronization has become an
extremely popular topic, the bulk of the research in this area has been focused
on the identical case, specifically because its invariant manifold is simply
the identity function, and there have yet to be any generally workable methods
to compute the generalized synchronization manifolds for non-identical systems.
Here, we derive time dependent PDEs whose stationary solution mirrors exactly
the generalized synchronization manifold, respecting its stability. We
introduce a novel method for dealing with subtle issues with boundary
conditions in the numerical scheme to solve the PDE, and we develop first order
expansions close to the identical case. We give several examples of increasing
sophistication, including coupled non-identical Van der Pol oscillators. By
using the manifold equation, we also discuss the design of coupling to achieve
desired synchronization.


title:
Side jump contribution to spin-orbit mediated Hall effects and Berry
  curvature

abstract:
  Anomalous Hall effect and spin Hall effect originate due to spin-orbit
coupling that in the Kohn-Luttinger ${\bf k}\cdot{\bf p}$ formalism is
represented by anomalous terms in the coordinate and velocity operators.
Relation of these operators to the Berry curvature in the momentum space is
presented for electrons in GaAs type semiconductors. For centrosymmetric
semiconductors, transformational properties of Berry curvature are discussed.


title: Low-frequency plasma conductivity in the average-atom approximation

abstract:
  Low-frequency properties of a plasma are examined within the average-atom
approximation, which presumes that scattering of a conducting electron on each
atom takes place independently of other atoms. The relaxation time tau
distinguishes a high-frequency region omega tau > 1, where the single-atom
approximation is applicable explicitly, from extreme low frequencies omega tau
< 1, where, naively, the single-atom approximation is invalid. A proposed
generalization of the formalism, which takes into account many-atom collisions,
is found to be accurate in all frequency regions, from omega =0 to omega tau
>1, reproducing the Ziman formula in the static limit, results based on the
Kubo-Greenwood formula for high frequencies, and satisfying the conductivity
sum-rule precisely. The correspondence between physical processes leading to
the conventional Ohm's law and the infrared properties of QED is discussed. The
suggested average-atom approach to frequency-dependent conductivity is
illustrated by numerical calculations for the an aluminum plasma in the
temperature range 2--10 eV.


title: Quantifying Chaos in Models of the Solar Neighbourhood

abstract:
  {} {To quantify the amount of chaos that exists in the local phase space.} {A
sample of orbits from four different models of the Solar neighbourhood phase
space are analysed by a new chaos identification (and quantification)
technique. While three of the used models bear the signature of the
perturbation due to both the Galactic bar and the spiral pattern, the last of
the models is a bar only one. We explore the models by inter-comparing the
corresponding values of chaos strength that is induced at the various energy
levels .}{(1) We find that of all the viable models that have been demonstrated
to successfully reproduce the local phase space structure, i.e. those that
include the bar as well as the spiral, bear strong chaoticity, though the model
that implies the highest degree of chaos is the one in which overlap of the
major resonances of the bar and the spiral occurs. The bar only model is found
to display regularity. (2) We advance chaos to be primarily responsible for the
splitting of the Hyades-Pleiades mode (the larger mode) of the local velocity
distribution}{}


title:
High-accuracy numerical simulation of black-hole binaries: Computation
  of the gravitational-wave energy flux and comparisons with post-Newtonian
  approximants

abstract:
  Expressions for the gravitational wave (GW) energy flux and center-of-mass
energy of a compact binary are integral building blocks of post-Newtonian (PN)
waveforms. In this paper, we compute the GW energy flux and GW frequency
derivative from a highly accurate numerical simulation of an equal-mass,
non-spinning black hole binary. We also estimate the (derivative of the)
center-of-mass energy from the simulation by assuming energy balance. We
compare these quantities with the predictions of various PN approximants
(adiabatic Taylor and Pade models; non-adiabatic effective-one-body (EOB)
models). We find that Pade summation of the energy flux does not accelerate the
convergence of the flux series; nevertheless, the Pade flux is markedly closer
to the numerical result for the whole range of the simulation (about 30 GW
cycles). Taylor and Pade models overestimate the increase in flux and frequency
derivative close to merger, whereas EOB models reproduce more faithfully the
shape of and are closer to the numerical flux, frequency derivative and
derivative of energy. We also compare the GW phase of the numerical simulation
with Pade and EOB models. Matching numerical and untuned 3.5 PN order
waveforms, we find that the phase difference accumulated until $M \omega = 0.1$
is -0.12 radians for Pade approximants, and 0.50 (0.45) radians for an EOB
approximant with Keplerian (non-Keplerian) flux. We fit free parameters within
the EOB models to minimize the phase difference, and confirm degeneracies among
these parameters. By tuning pseudo 4PN order coefficients in the radial
potential or in the flux, or, if present, the location of the pole in the flux,
we find that the accumulated phase difference can be reduced - if desired - to
much less than the estimated numerical phase error (0.02 radians).


title: Infall caustics in dark matter halos?

abstract:
  We show that most particle and subhalo orbits in simulated cosmological cold
dark matter halos are surprisingly regular and periodic: The phase space
structure of the outer halo regions shares some of the properties of the
classical self-similar secondary infall model. Some of the outer branches are
clearly visible in the radial velocity - radius plane at certain epochs.
However, they are severely broadened in realistic, triaxial halos with
non-radial, clumpy, mass accretion. This prevents the formation of high density
caustics: Even in the best cases there are only broad, very small (<10 percent)
enhancements in the spherical density profile. Larger fluctuations in rho(r)
caused by massive satellites are common. Infall caustics are therefore too weak
to affect lensing or dark matter annihilation experiments. Their detection is
extremely challenging, as it requires a large number of accurate tracer
positions and radial velocities in the outer halo. The stellar halo of the
Milky Way is probably the only target where this could become feasible in the
future.


title:
Generation of squeezed states of microwave radiation in a
  superconducting resonant circuit

abstract:
  High-quality superconducting oscillators have been successfully used for
quantum control and readout devices in conjunction with superconducting qubits.
Also, it is well known that squeezed states can improve the accuracy of
measurements to subquantum, or at least subthermal, levels. Here we show
theoretically how to produce squeezed states of microwave radiation in a
superconducting oscillator with tunable parameters. The circuit impedance, and
thus the resonance frequency, can be changed by controlling the state of an RF
SQUID inductively coupled to the oscillator. By repeatedly shifting the
resonance frequency between any two values, it is possible to produce squeezed
and subthermal states of the electromagnetic field in the (0.1--10) GHz range,
even when the relative frequency change is small. We propose experimental
protocols for the verification of squeezed state generation, and for their use
to improve the readout fidelity when such oscillators serve as quantum
transducers.


title:
On the Asymptotic Behavior of Selfish Transmitters Sharing a Common
  Channel

abstract:
  This paper analyzes the asymptotic behavior of a multiple-access network
comprising a large number of selfish transmitters competing for access to a
common wireless communication channel, and having different utility functions
for determining their strategies. A necessary and sufficient condition is given
for the total number of packet arrivals from selfish transmitters to converge
in distribution. The asymptotic packet arrival distribution at Nash equilibrium
is shown to be a mixture of a Poisson distribution and finitely many Bernoulli
distributions.


title: Syzygies of multiplier ideals on singular varieties

abstract:
  It was recently established by the first two authors that multiplier ideals
on a smooth variety satisfy some special syzygetic properties. The purpose of
this note is to show how some of these can be extended to the singular setting.


title: Solving the Coagulation Equation by the Moments Method

abstract:
  We demonstrate an approach to solving the coagulation equation that involves
using a finite number of moments of the particle size distribution. This
approach is particularly useful when only general properties of the
distribution, and their time evolution, are needed. The numerical solution to
the integro-differential Smoluchowski coagulation equation at every time step,
for every particle size, and at every spatial location is computationally
expensive, and serves as the primary bottleneck in running evolutionary models
over long periods of time. The advantage of using the moments method comes in
the computational time savings gained from only tracking the time rate of
change of the moments, as opposed to tracking the entire mass histogram which
can contain hundreds or thousands of bins depending on the desired accuracy.
The collision kernels of the coagulation equation contain all the necessary
information about particle relative velocities, cross-sections, and sticking
coefficients. We show how arbitrary collision kernels may be treated. We
discuss particle relative velocities in both turbulent and non-turbulent
regimes. We present examples of this approach that utilize different collision
kernels and find good agreement between the moment solutions and the moments as
calculated from direct integration of the coagulation equation. As practical
applications, we demonstrate how the moments method can be used to track the
evolving opacity, and also indicate how one may incorporate porous particles.


title:
Exactly solvable PT-symmetric Hamiltonian having no Hermitian
  counterpart

abstract:
  In a recent paper Bender and Mannheim showed that the unequal-frequency
fourth-order derivative Pais-Uhlenbeck oscillator model has a realization in
which the energy eigenvalues are real and bounded below, the Hilbert-space
inner product is positive definite, and time evolution is unitary. Central to
that analysis was the recognition that the Hamiltonian $H_{\rm PU}$ of the
model is PT symmetric. This Hamiltonian was mapped to a conventional
Dirac-Hermitian Hamiltonian via a similarity transformation whose form was
found exactly. The present paper explores the equal-frequency limit of the same
model. It is shown that in this limit the similarity transform that was used
for the unequal-frequency case becomes singular and that $H_{\rm PU}$ becomes a
Jordan-block operator, which is nondiagonalizable and has fewer energy
eigenstates than eigenvalues. Such a Hamiltonian has no Hermitian counterpart.
Thus, the equal-frequency PT theory emerges as a distinct realization of
quantum mechanics. The quantum mechanics associated with this Jordan-block
Hamiltonian can be treated exactly. It is shown that the Hilbert space is
complete with a set of nonstationary solutions to the Schr\"odinger equation
replacing the missing stationary ones. These nonstationary states are needed to
establish that the Jordan-block Hamiltonian of the equal-frequency
Pais-Uhlenbeck model generates unitary time evolution.


title: Theory of market fluctuations

abstract:
  We propose coalescent mechanism of economic grow because of redistribution of
external resources. It leads to Zipf distribution of firms over their sizes,
turning to stretched exponent because of size-dependent effects, and predicts
exponential distribution of income between individuals. We also present new
approach to describe fluctuations on the market, based on separation of hot
(short-time) and cold (long-time) degrees of freedoms, which predicts tent-like
distribution of fluctuations with stable tail exponent mu=3 (mu=2 for news).
The theory predicts observable asymmetry of the distribution, and its size
dependence. In the case of financial markets the theory explains first time
market mill patterns, conditional distribution, D-smile, z-shaped response,
conditional double dynamics, the skewness and so on. We derive the set of
Langeven equations, which predicts logarithmic dependence of price shift on
trading volume and volatility patterns after jumps. We calculate parameters of
price distributions, correlation functions and Hurst exponents at different
time scales. At large times the price experiences fractional Brownian motion
with chaotically switching of long-time persistent and anti-persistent
behavior, and we calculate corresponding probabilities, response functions, and
risks.


title: Low-scale Gaugino Mass Unification

abstract:
  We study a new class of scenarios with the gaugino mass unification at the
weak scale. The general condition is first derived for the unification to
occur. Among the general cases, a particular attention is drawn to the mirage
gauge mediation where the low-energy mass spectrum is governed by the mirage of
unified gauge coupling which is seen by low-energy observers. The gaugino
masses have natural and stable low-scale unification. The mass parameters of
scalar quarks and leptons are given by gauge couplings but exhibit no large
mass hierarchy. They are non-universal even when mediated at the gauge coupling
unification scale. In addition, the gravitino is rather heavy and not the
lightest superparticle. These facts are in contrast to existing gauge and
mirage mediation models. We also present several explicit models for
dynamically realizing the TeV-scale unification.


title: The Morse Index of Wente Tori

abstract:
  We find various lower and upper bounds for the index of Wente tori that
contain a continuous family of planar principal curves. We then prove a result
that gives an algorithm for computing the index sharply.


title: Asymptotic Bound on Binary Self-Orthogonal Codes

abstract:
  We present two constructions for binary self-orthogonal codes. It turns out
that our constructions yield a constructive bound on binary self-orthogonal
codes. In particular, when the information rate R=1/2, by our constructive
lower bound, the relative minimum distance \delta\approx 0.0595 (for GV bound,
\delta\approx 0.110). Moreover, we have proved that the binary self-orthogonal
codes asymptotically achieve the Gilbert-Varshamov bound.


title: Multi-Antenna Gaussian Broadcast Channels with Confidential Messages

abstract:
  In wireless data networks, communication is particularly susceptible to
eavesdropping due to its broadcast nature. Security and privacy systems have
become critical for wireless providers and enterprise networks. This paper
considers the problem of secret communication over a Gaussian broadcast
channel, where a multi-antenna transmitter sends independent confidential
messages to two users with \emph{information-theoretic secrecy}. That is, each
user would like to obtain its own confidential message in a reliable and safe
manner. This communication model is referred to as the multi-antenna Gaussian
broadcast channel with confidential messages (MGBC-CM). Under this
communication scenario, a secret dirty-paper coding scheme and the
corresponding achievable secrecy rate region are first developed based on
Gaussian codebooks. Next, a computable Sato-type outer bound on the secrecy
capacity region is provided for the MGBC-CM. Furthermore, the Sato-type outer
bound proves to be consistent with the boundary of the secret dirty-paper
coding achievable rate region, and hence, the secrecy capacity region of the
MGBC-CM is established. Finally, a numerical example demonstrates that both
users can achieve positive rates simultaneously under the information-theoretic
secrecy requirement.