title:
A Planetary System Around HD 155358: The Lowest Metallicity Planet Host
  Star

abstract:
  We report the detection of two planetary mass companions to the solar-type
star HD 155358. The two planets have orbital periods of 195.0 and 530.3 days,
with eccentricities of 0.11 and 0.18. The minimum masses for these planets are
0.89 and 0.50 Jupiter masses respectively. The orbits are close enough to each
other, and the planets are sufficiently massive, that the planets are
gravitationally interacting with each other, with their eccentricities and
arguments of periastron varying with periods of 2300--2700 years. While large
uncertainties remain in the orbital eccentricities, our orbital integration
calculations indicate that our derived orbits would be dynamically stable for
at least 10^8 years. With a metallicity [Fe/H] of -0.68, HD 155358 is tied with
the K1III giant planet host star HD 47536 for the lowest metallicity of any
planet host star yet found. Thus, a star with only 21% of the heavy-element
content of our Sun was still able to form a system of at least two Jovian-mass
planets and have their orbits evolve to semi-major axes of 0.6-1.2 AU.


title: Observation and Properties of L=1 B_1 and B_2* Mesons

abstract:
  Excited B mesons B_1 and B_2* are observed directly for the first time as two
separate states in fully reconstructed decays to B+(*) pi-. The mass of B_1 is
measured to be (5720.6 +- 2.4 +- 1.4) MeV/c^2 and the mass difference DeltaM
between B_2* and B_1 is (26.2 +- 3.1 +- 0.9) MeV/c^2, giving the mass of the
B_2* as (5746.8 +- 2.4 +- 1.7) MeV/c^2. The production rate for B_1 and B_2*
mesons is determined to be a fraction (13.9 +- 1.9 +- 3.2)% of the production
rate of the B+ meson.


title: The color-singlet contribution to e^+ e^- ->J/psi + X at the endpoint

abstract:
  Recent observations of the J/psi spectrum produced in e^+e^- collisions at
the Upsilon(4S) resonance are in conflict with fixed-order calculations using
Non-Relativsitic QCD effective theory (NRQCD). One problem is an enhancement in
the cross section when the J/psi has maximal energy, due to large perturbative
corrections (Sudakov logarithms). In a recent paper, the Sudakov logarithms in
the color-octet contribution were summed by combining NRQCD with the
Soft-Collinear Effective Theory. However to be consistent, the color-singlet
contributions must also be summed in the endpoint region which was not done in
that paper. In this paper, we sum the leading and next-to-leading logarithms in
the color-singlet contribution to the J/psi production cross section. We find
that the color-singlet cross section is suppressed near endpoint compared to
the fixed order NRQCD prediction.


title: Cohomology of the adjoint of Hopf algebras

abstract:
  A cohomology theory of the adjoint of Hopf algebras, via deformations, is
presented by means of diagrammatic techniques. Explicit calculations are
provided in the cases of group algebras, function algebras on groups, and the
bosonization of the super line. As applications, solutions to the YBE are given
and quandle cocycles are constructed from groupoid cocycles.


title: Chemical Differences between K and Na in Alkali Cobaltates

abstract:
  K$_x$CoO$_2$ shares many similarities with Na$_x$CoO$_2$, as well as some
important differences (no hydration-induced superconductivity has been
reported). At $T_{c2}$=20 K, K$_{0.5}$CoO$_2$ becomes an insulator with a tiny
optical gap as happens in Na$_{0.5}$CoO$_2$ at 52 K. This similarity, with a
known common structure, enables direct comparisons to be made. Using the
K-zigzag structure recently reported and the local density approximation, we
compare and contrast these cobaltates at x=0.5. Although the electronic
structures are quite similar as expected, substantial differences are observed
near the Fermi level. These differences are found to be attributable mostly to
the chemical, rather than structural difference: although Na is normally
considered to be fully ion, K has somewhat more highly ionic character than
does Na in these cobaltates.


title:
On the Collection of Integers that Index the Fixed Points of Maps on the
  Space of Rational Functions

abstract:
  Given integers s and t, define a function phi_{s,t} on the space of all
formal complex series expansions by phi_{s,t} (sum a_n x^n) = sum a_{sn+t} x^n.
We define an integer r to be distinguished with respect to (s,t) if r and s are
relatively prime and and r divides t (1 + s + ... s^{ord_r(s)-1}). The vector
space consisting of all rational functions whose Taylor expansions at zero are
fixed by phi_{s,t} was previously classified by constructing a basis that is
partially indexed by integers that are distinguished with respect to the pair
(s,t). In this paper, we study the properties of the set of distinguished
integers with respect to (s,t). In particular, we demonstrate that the set of
distinguished integers with respect to (s,t) can be written as a union of
infinitely many arithmetic progressions. In addition, we construct another
generating set for the collection of rational functions that are fixed by
phi_{s,t} and discuss the relationship between this generating set and the
basis that was generated previously.


title:
Development of an apparatus for cooling 6Li-87Rb Fermi-Bose mixtures in
  a light-assisted magnetic trap

abstract:
  We describe an experimental setup designed to produce ultracold trapped gas
clouds of fermionic 6Li and bosonic 87Rb. This combination of alkali metals has
the potential to reach deeper Fermi degeneracy with respect to other mixtures
since it allows for improved heat capacity matching which optimizes sympathetic
cooling efficiency. Atomic beams of the two species are independently produced
and then decelerated by Zeeman slowers. The slowed atoms are collected into a
magneto-optical trap and then transferred into a quadrupole magnetic trap. An
ultracold Fermi gas with temperature in the 10^-3 T_F range should be
attainable through selective confinement of the two species via a properly
detuned laser beam focused in the center of the magnetic trap.


title: Cosmic ray confinement in fossil cluster bubbles

abstract:
  Most cool core clusters of galaxies possess active galactic nuclei (AGN) in
their centers. These AGN inflate buoyant bubbles containing non-thermal radio
emitting particles. If such bubbles efficiently confine cosmic rays (CR) then
this could explain ``radio ghosts'' seen far from cluster centers. We simulate
the diffusion of cosmic rays from buoyant bubbles inflated by AGN. Our
simulations include the effects of the anisotropic particle diffusion
introduced by magnetic fields. Our models are consistent with the X-ray
morphology of AGN bubbles, with disruption being suppressed by the magnetic
draping effect. We conclude that for such magnetic field topologies, a
substantial fraction of cosmic rays can be confined inside the bubbles on
buoyant rise timescales even when the parallel diffusivity coefficient is very
large. For isotropic diffusion at a comparable level, cosmic rays would leak
out of the bubbles too rapidly to be consistent with radio observations. Thus,
the long confinement times associated with the magnetic suppression of CR
diffusion can explain the presence of radio ghosts. We show that the partial
escape of cosmic rays is mostly confined to the wake of the rising bubbles, and
speculate that this effect could: (1) account for the excitation of the
H$\alpha$ filaments trailing behind the bubbles in the Perseus cluster, (2)
inject entropy into the metal enriched material being lifted by the bubbles
and, thus, help to displace it permanently from the cluster center and (3)
produce observable $\gamma$-rays via the interaction of the diffusing cosmic
rays with the thermal intracluster medium (ICM).


title:
Eigenvectors of Baxter-Bazhanov-Stroganov \tau^{(2)}(t_q) model with
  fixed-spin boundary conditions

abstract:
  The aim of this contribution is to give the explicit formulas for the
eigenvectors of the transfer-matrix of Baxter-Bazhanov-Stroganov (BBS) model
(N-state spin model) with fixed-spin boundary conditions. These formulas are
obtained by a limiting procedure from the formulas for the eigenvectors of
periodic BBS model. The latter formulas were derived in the framework of the
Sklyanin's method of separation of variables. In the case of fixed-spin
boundaries the corresponding T-Q Baxter equations for the functions of
separated variables are solved explicitly. As a particular case we obtain the
eigenvectors of the Hamiltonian of Ising-like Z_N quantum chain model.

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


title: Deformed solitons: The case of two coupled scalar fields

abstract:
  In this work, we present a general procedure, which is able to generate new
exact solitonic models in 1+1 dimensions, from a known one, consisting of two
coupled scalar fields. An interesting consequence of the method, is that of the
appearing of nontrivial extensions, where the deformed systems presents other
BPS solitons than that appearing in the original model. Finally we take a
particular example, in order to check the above mentioned features.


title:
Transverse momentum and centrality dependence of dihadron correlations
  in Au+Au collisions at sqrt(s_NN)=200 GeV: Jet-quenching and the response of
  partonic matter

abstract:
  Azimuthal angle \Delta\phi correlations are presented for charged hadrons
from dijets for 0.4 < p_T < 10 GeV/c in Au+Au collisions at sqrt(s_NN) = 200
GeV. With increasing p_T, the away-side distribution evolves from a broad to a
concave shape, then to a convex shape. Comparisons to p+p data suggest that the
away-side can be divided into a partially suppressed "head" region centered at
Delta\phi ~ \pi, and an enhanced "shoulder" region centered at Delta\phi ~ \pi
+/- 1.1. The p_T spectrum for the "head" region softens toward central
collisions, consistent with the onset of jet quenching. The spectral slope for
the "shoulder" region is independent of centrality and trigger p_T, which
offers constraints on energy transport mechanisms and suggests that the
"shoulder" region contains the medium response to energetic jets.


title:
Charge Transport and Inhomogeneity near the Charge Neutrality Point in
  Graphene

abstract:
  The magnetic field-dependent longitudinal and Hall components of the
resistivity rho_xx(H) and rho_xy(H) are measured in graphene on silicon dioxide
substrates at temperatures from 1.6 K to room temperature. At charge densities
near the charge-neutrality point rho_xx(H) is strongly enhanced and rho_xy(H)
is suppressed, indicating nearly equal electron and hole contributions to the
transport current. The data are inconsistent with uniformly distributed
electron and hole concentrations (two-fluid model) but in excellent agreement
with the recent theoretical prediction for inhomogeneously distributed electron
and hole regions of equal mobility. At low temperatures and high magnetic
fields rho_xx(H) saturates to a value ~h/e^2, with Hall conductivity << e^2/h,
which may indicate a regime of localized v = 2 and v = -2 quantum Hall puddles.


title: Kinematics of Spiral Arm Streaming in M51

abstract:
  We use CO and H alpha velocity fields to study the gas kinematics in the
spiral arms and interarms of M51 (NGC 5194), and fit the 2D velocity field to
estimate the radial and tangential velocity components as a function of spiral
phase (arm distance). We find large radial and tangential streaming velocities,
which are qualitatively consistent with the predictions of density wave theory
and support the existence of shocks. The streaming motions are complex, varying
significantly across the galaxy as well as along and between arms. Aberrations
in the velocity field indicate that the disk is not coplanar, perhaps as far in
as 20\arcsec\ (800 pc) from the center. Velocity profile fits from CO and H
alpha are typically similar, suggesting that most of the H alpha emission
originates from regions of recent star formation. We also explore vortensity
and mass conservation conditions. Vortensity conservation, which does not
require a steady state, is empirically verified. The velocity and density
profiles show large and varying mass fluxes, which are inconsistent with a
steady flow for a single dominant global spiral mode. We thus conclude that the
spiral arms cannot be in a quasi-steady state in any rotating frame, and/or
that out of plane motions may be significant.


title: On the icosahedron: from two to three dimensions

abstract:
  In his famous book, Felix Klein describes a complex variable for the
quotients of the ordinary sphere by the finite groups of rotations and in
particular for the most complex situation of the quotient by the symmetry group
of the icosahedron. The purpose of this work and its sequels is to obtain
similar results for the quotients of the three--dimensional sphere. Various
properties of the group $SU(2)$ and of its representations are used to obtain
explicit expressions for coordinates and the relations they satisfy.


title:
Monitoring the Violent Activity from the Inner Accretion Disk of the
  Seyfert 1.9 Galaxy NGC 2992 with RXTE

abstract:
  We present the results of a one year monitoring campaign of the Seyfert 1.9
galaxy NGC 2992 with RXTE. Historically, the source has been shown to vary
dramatically in 2-10 keV flux over timescales of years and was thought to be
slowly transitioning between periods of quiescence and active accretion. Our
results show that in one year the source continuum flux covered almost the
entire historical range, making it unlikely that the low-luminosity states
correspond to the accretion mechanism switching off. During flaring episodes we
found that a highly redshifted Fe K line appears, implying that the violent
activity is occurring in the inner accretion disk, within ~100 gravitational
radii of the central black hole. We also found that the spectral index of the
X-ray continuum remained approximately constant during the large amplitude
variability. These observations make NGC 2992 well-suited for future
multi-waveband monitoring, as a test-bed for constraining accretion models.


title:
Bias reduction in traceroute sampling: towards a more accurate map of
  the Internet

abstract:
  Traceroute sampling is an important technique in exploring the internet
router graph and the autonomous system graph. Although it is one of the primary
techniques used in calculating statistics about the internet, it can introduce
bias that corrupts these estimates. This paper reports on a theoretical and
experimental investigation of a new technique to reduce the bias of traceroute
sampling when estimating the degree distribution. We develop a new estimator
for the degree of a node in a traceroute-sampled graph; validate the estimator
theoretically in Erdos-Renyi graphs and, through computer experiments, for a
wider range of graphs; and apply it to produce a new picture of the degree
distribution of the autonomous system graph.


title:
VHE Gamma-Ray Observation of the Crab Nebula and its Pulsar with the
  MAGIC telescope

abstract:
  We report about very high energy (VHE) gamma-ray observations of the Crab
Nebula with the MAGIC telescope. The gamma-ray flux from the nebula was
measured between 60 GeV and 9 TeV. The energy spectrum can be described with a
curved power law dF/dE=f0 (E/300 GeV)^(a+b*log10(E/300 GeV)) with a flux
normalization f0 of(6.0+-0.2)*10^-10 1/(cm^2 s TeV), a=-2.31+-0.06 and
b=-0.26+-0.07. The position of the IC-peak is determined at (77+-47) GeV.
Within the observation time and the experimental resolution of the telescope,
the gamma-ray emission is steady and pointlike. The emission's center of
gravity coincides with the position of the pulsar. Pulsed gamma-ray emission
from the pulsar could not be detected. We constrain the cutoff energy of the
spectrum to be less than 27 GeV, assuming that the differential energy spectrum
has an exponential cutoff. For a super-exponential shape, the cutoff energy can
be as high as 60 GeV.


title: The Kinetic Sunyaev-Zel'dovich Effect Due to the Electrons of Our Galaxy

abstract:
  We compute the effect of local electrons on the CMB temperature anisotropies.
The number density and distribution of free electrons in our Galaxy has been
accurately measured from pulsar dispersion measurements. Because of their
distribution, the dynamics of our Galaxy and the Galaxy peculiar velocity with
respect to the Hubble flow, these free electrons leave a frequency-independent
imprint on the cosmic microwave background (CMB). In particular, the coherent
motion of the free electrons respect to us and to the CMB rest frame produce a
kinetic Sunyaev-Zeldovich signal. We compute this effect and we note that the
large-scale antisymmetry of the signal gives it an angular power spectrum with
a sawtooth pattern where even multipoles are suppressed with respect to the odd
ones. We find the signal to be small (~ 2 uK) and sub-dominant compared to the
primary CMB and other foreground signals. However, since there are no free
parameters in the modeling of this signal, it can be taken into account if more
precise measurements of the primordial signal are required.


title:
The Difference PDF of 21-cm Fluctuations: A Powerful Statistical Tool
  for Probing Cosmic Reionization

abstract:
  A new generation of radio telescopes are currently being built with the goal
of tracing the cosmic distribution of atomic hydrogen at redshifts 6-15 through
its 21-cm line. The observations will probe the large-scale brightness
fluctuations sourced by ionization fluctuations during cosmic reionization.
Since detailed maps will be difficult to extract due to noise and foreground
emission, efforts have focused on a statistical detection of the 21-cm
fluctuations. During cosmic reionization, these fluctuations are highly
non-Gaussian and thus more information can be extracted than just the
one-dimensional function that is usually considered, i.e., the correlation
function. We calculate a two-dimensional function that if measured
observationally would allow a more thorough investigation of the properties of
the underlying ionizing sources. This function is the probability distribution
function (PDF) of the difference in the 21-cm brightness temperature between
two points, as a function of the separation between the points. While the
standard correlation function is determined by a complicated mixture of
contributions from density and ionization fluctuations, we show that the
difference PDF holds the key to separately measuring the statistical properties
of the ionized regions.


title: Ordering ambiguity versus representation

abstract:
  In this work we show that the ordering ambiguity on quantization depends on
the representation choice. This property is then used to solve unambiguously
some particular systems. Finally, we speculate on the consequences for more
involved cases.


title: On a generalised model for time-dependent variance with long-term memory

abstract:
  The ARCH process (R. F. Engle, 1982) constitutes a paradigmatic generator of
stochastic time series with time-dependent variance like it appears on a wide
broad of systems besides economics in which ARCH was born. Although the ARCH
process captures the so-called "volatility clustering" and the asymptotic
power-law probability density distribution of the random variable, it is not
capable to reproduce further statistical properties of many of these time
series such as: the strong persistence of the instantaneous variance
characterised by large values of the Hurst exponent (H > 0.8), and asymptotic
power-law decay of the absolute values self-correlation function. By means of
considering an effective return obtained from a correlation of past returns
that has a q-exponential form we are able to fix the limitations of the
original model. Moreover, this improvement can be obtained through the correct
choice of a sole additional parameter, $q_{m}$. The assessment of its validity
and usefulness is made by mimicking daily fluctuations of SP500 financial
index.


title: Translation Groupoids and Orbifold Bredon Cohomology

abstract:
  We show that the bicategory of (representable) orbifolds and good maps is
equivalent to the bicategory of orbifold translation groupoids and generalized
equivariant maps. We use this result to define an orbifold version of Bredon
cohomology.


title:
Yangian of the Strange Lie Superalgebra of $\boldsymbol{Q_{n-1}}$ Type,
  Drinfel'd Approach

abstract:
  The Yangian of the strange Lie superalgebras in Drinfel'd realization is
defined. The current system generators and defining relations are described.


title: Tevatron-for-LHC Report: Top and Electroweak Physics

abstract:
  The top quark and electroweak bosons (W and Z) represent the most massive
fundamental particles yet discovered, and as such refer directly to the
Standard Model's greatest remaining mystery: the mechanism by which all
particles gained mass. This report summarizes the work done within the top-ew
group of the Tevatron-for-LHC workshop. It represents a collection of both
Tevatron results, and LHC predictions. The hope is that by considering and
comparing both machines, the LHC program can be improved and aided by knowledge
from the Tevatron, and that particle physics as a whole can be enriched. The
report includes measurements of the top quark mass, searches for single top
quark production, and physics of the electroweak bosons at hadron colliders.


title:
The Hilbert 3/2 Structure and Weil-Petersson Metric on the Space of the
  Diffeomorphisms of the Circle Modulo Conformal Maps

abstract:
  We gave a new very simple proof that the completion of the space of the
diffeomorphism of the circle modulo conformal maps with respect to the
Weil-Petersson Metric is a complex analytic manifold modeled on the Hilbert
space with 3/2 Sobolev norm. Our proof is based on the analogue of the Hadamard
Theorem that the exponentila map is a complex analytic map from the tanegnt
space of a point of a simply connected manifold to the manifold.


title:
Non-Perturbative Corrections and Modularity in N=1 Type IIB
  Compactifications

abstract:
  Non-perturbative corrections and modular properties of four-dimensional type
IIB Calabi-Yau orientifolds are discussed. It is shown that certain
non-perturbative alpha' corrections survive in the large volume limit of the
orientifold and periodically correct the Kahler potential. These corrections
depend on the NS-NS two form and have to be completed by D-instanton
contributions to transform covariantely under symmetries of the type IIB
orientifold background. It is shown that generically also the D-instanton
superpotential depends on the two-form moduli as well as on the complex
dilaton. These contributions can arise through theta-functions with the dilaton
as modular parameter. An orientifold of the Enriques Calabi-Yau allows to
illustrate these general considerations. It is shown that this compactification
leads to a controlled four-dimensional N=1 effective theory due to the absence
of various quantum corrections. Making contact to the underlying topological
string theory the D-instanton superpotential is proposed to be related to a
specific modular form counting D3, D1, D(-1) degeneracies on the Enriques
Calabi-Yau.


title:
Diagnostics of stellar flares from X-ray observations: from the decay to
  the rise phase

abstract:
  The diagnostics of stellar flaring coronal loops have been so far largely
based on the analysis of the decay phase. We derive new diagnostics from the
analysis of the rise and peak phase of stellar flares. We release the
assumption of full equilibrium of the flaring loop at the flare peak, according
to the frequently observed delay between the temperature and the density
maximum. From scaling laws and hydrodynamic simulations we derive diagnostic
formulas as a function of observable quantities and times. We obtain a
diagnostic toolset related to the rise phase, including the loop length,
density and aspect ratio. We discuss the limitations of this approach and find
that the assumption of loop equilibrium in the analysis of the decay leads to a
moderate overestimate of the loop length. A few relevant applications to
previously analyzed stellar flares are shown. The analysis of the flare rise
and peak phase complements and completes the analysis of the decay phase.


title:
Spinon-holon interactions in an anisotropic t-J chain: a comprehensive
  study

abstract:
  We consider a generalization of the one-dimensional t-J model with
anisotropic spin-spin interactions. We show that the anisotropy leads to an
effective attractive interaction between the spinon and holon excitations,
resulting in a localized bound state. Detailed quantitative analytic
predictions for the dependence of the binding energy on the anisotropy are
presented, and verified by precise numerical simulations. The binding energy is
found to interpolate smoothly between a finite value in the t-Jz limit and zero
in the isotropic limit, going to zero exponentially in the vicinity of the
latter. We identify changes in spinon dispersion as the primary factor for this
non-trivial behavior.


title:
Reconstructing the free energy landscape of a mechanically unfolded
  model protein

abstract:
  The equilibrium free energy landscape of an off-lattice model protein as a
function of an internal (reaction) coordinate is reconstructed from
out-of-equilibrium mechanical unfolding manipulations. This task is
accomplished via two independent methods: by employing an extended version of
the Jarzynski equality (EJE) and the protein inherent structures (ISs). In a
range of temperatures around the ``folding transition'' we find a good
quantitative agreement between the free energies obtained via EJE and IS
approaches. This indicates that the two methodologies are consistent and able
to reproduce equilibrium properties of the examined system. Moreover, for the
studied model the structural transitions induced by pulling can be related to
thermodynamical aspects of folding.


title: Evaluating Throwing Ability in Baseball

abstract:
  We present a quantitative analysis of throwing ability for major league
outfielders and catchers. We use detailed game event data to tabulate success
and failure events in outfielder and catcher throwing opportunities. We
attribute a run contribution to each success or failure which are tabulated for
each player in each season. We use four seasons of data to estimate the overall
throwing ability of each player using a Bayesian hierarchical model. This model
allows us to shrink individual player estimates towards an overall population
mean depending on the number of opportunities for each player. We use the
posterior distribution of player abilities from this model to identify players
with significant positive and negative throwing contributions.


title: Disks around Young Binary Stars

abstract:
  The majority of stars in known star-forming regions are located in binary
systems. Although the separation distribution of these populations varies from
one region to another, most peak between a few and several tens of AU. Given
the >100 AU distance to the youngest regions, binaries with this separation
range are also the most poorly studied. In general, only for about 60 young
pairs have the circumstellar disks and the stellar properties been
well-characterized. We discuss results of recent analyses of inner and outer
disk properties, summarize the status of observations of disk orientations, and
highlight two cases of debris disks in relatively young binaries. A substantial
effort, taking advantage of available and future high-angular resolution
facilities, will be required to further our knowledge of disk evolution in
binaries across the range of separations influential to both terrestrial as
well as giant planet formation.


title:
The Discovery of a Persistent Quasi-Periodic Oscillation in the
  Intermediate Polar TX Col

abstract:
  We report on the detection of an ~5900 s quasi-periodic variation in the
extensive photometry of TX Col spanning 12 years. We discuss five different
models to explain this period. We favour a mechanism where the quasi-periodic
variation results from the beating of the Keplerian frequency of the `blobs'
orbiting in the outer accretion disc with the spin frequency, and from
modulated accretion of these `blobs' taking place in a shocked region near the
disc/magnetosphere boundary.


title: Scalar resonances: scattering and production amplitudes

abstract:
  Scattering and production amplitudes involving scalar resonances are known,
according to Watson's theorem, to share the same phase $\delta(s)$. We show
that, at low energies, the production amplitude is fully determined by the
combination of $\delta(s)$ with another phase $\omega(s)$, which describes
intermediate two-meson propagation and is theoretically unambiguous. Our main
result is a simple and almost model independent expression, which generalizes
the usual $K$-matrix unitarization procedure and is suited to be used in
analyses of production data involving scalar resonances.


title:
Recovering Multiplexing Loss Through Successive Relaying Using
  Repetition Coding

abstract:
  In this paper, a transmission protocol is studied for a two relay wireless
network in which simple repetition coding is applied at the relays.
Information-theoretic achievable rates for this transmission scheme are given,
and a space-time V-BLAST signalling and detection method that can approach them
is developed. It is shown through the diversity multiplexing tradeoff analysis
that this transmission scheme can recover the multiplexing loss of the
half-duplex relay network, while retaining some diversity gain. This scheme is
also compared with conventional transmission protocols that exploit only the
diversity of the network at the cost of a multiplexing loss. It is shown that
the new transmission protocol offers significant performance advantages over
conventional protocols, especially when the interference between the two relays
is sufficiently strong.


title: Chemical chronology of the Southern Coalsack

abstract:
  We demonstrate how the observed H2O ice column densities toward three dense
globules in the Southern Coalsack could be used to constrain the ages of these
sources. We derive ages of ~10^5 yr, in agreement with dynamical studies of
these objects. We have modelled the chemical evolution of the globules, and
show how the molecular abundances are controlled by both the gas density and
the initial chemical conditions as the globules formed. Based on our derived
ages, we predict the column densities of several species of interest. These
predictions should be straightforward to test by performing molecular line
observations


title: Chiral Anomaly Beyond Lorentz Invariance

abstract:
  The chiral anomaly in the context of an extended standard model with minimal
Lorentz invariance violation is studied. Taking into account bounds from
measurements of the speed of light, we argue that the chiral anomaly and its
consequences are general results valid even beyond the relativistic symmetry.


title:
Massive enhancement of electron-phonon coupling in doped graphene by an
  electronic singularity

abstract:
  The nature of the coupling leading to superconductivity in layered materials
such as high-Tc superconductors and graphite intercalation compounds (GICs) is
still unresolved. In both systems, interactions of electrons with either
phonons or other electrons or both have been proposed to explain
superconductivity. In the high-Tc cuprates, the presence of a Van Hove
singularity (VHS) in the density of states near the Fermi level was long ago
proposed to enhance the many-body couplings and therefore may play a role in
superconductivity. Such a singularity can cause an anisotropic variation in the
coupling strength, which may partially explain the so-called nodal-antinodal
dichotomy in the cuprates. Here we show that the topology of the graphene band
structure at dopings comparable to the GICs is quite similar to that of the
cuprates and that the quasiparticle dynamics in graphene have a similar
dichotomy. Namely, the electron-phonon coupling is highly anisotropic,
diverging near a saddle point in the graphene electronic band structure. These
results support the important role of the VHS in layered materials and the
possible optimization of Tc by tuning the VHS with respect to the Fermi level.


title: Towards A Nonsingular Tachyonic Big Crunch

abstract:
  We discuss an effective field theory background containing the gravitational
field, the dilaton and a closed string tachyon, and couple this background to a
gas of fundamental strings and D strings. Allowing for the possibility of a
non-vanishing dilaton potential of Casimir type, we demonstrate the possibility
of obtaining a nonsingular, static tachyon condensate phase with fixed dilaton.
The time reversal of our solution provides a candidate effective field theory
description of a Hagedorn phase of string gas cosmology with fixed dilaton.


title: Far field imaging by a planar lens: diffraction versus superresolution

abstract:
  We resolve the long standing controversy regarding the imaging by a planar
lens made of left-handed media and demonstrate theoretically that its far field
image has a fundamentally different origin depending on the relationship
between losses {inside} the lens and the wavelength of the light $\lambda$. At
small enough $\lambda$ the image is always governed by diffraction theory, and
the resolution is independent of the absorption if both Im$\epsilon \ll 1$ and
Im$\mu \ll 1$. For any finite $\lambda$, however, a critical absorption exists
below which the superresolution regime takes place, though this absorption is
extremely low and can hardly be achieved. We demonstrate that the transition
between diffraction limited and superresolution regimes is governed by {the}
universal parameter combining absorption, wavelength, and lens thickness.
Finally, we show that this parameter is related to the resonant excitation of
the surface plasma waves.


title: The local stellar velocity field via vector spherical harmonics

abstract:
  We analyze the local field of stellar tangential velocities for a sample of
$42 339$ non-binary Hipparcos stars with accurate parallaxes, using a vector
spherical harmonic formalism. We derive simple relations between the parameters
of the classical linear model (Ogorodnikov-Milne) of the local systemic field
and low-degree terms of the general vector harmonic decomposition. Taking
advantage of these relationships we determine the solar velocity with respect
to the local stars of $(V_X,V_Y,V_Z)=(10.5, 18.5, 7.3)\pm 0.1$ \kms. The Oort's
parameters determined by a straightforward least-squares adjustment in vector
spherical harmonics, are $A=14.0\pm 1.4$, $B=-13.1\pm 1.2$, $K=1.1\pm 1.8$, and
$C=-2.9\pm 1.4$ \kmspc. We find a few statistically significant higher degree
harmonic terms, which do not correspond to any parameters in the classical
linear model. One of them, a third-degree electric harmonic, is tentatively
explained as the response to a negative linear gradient of rotation velocity
with distance from the Galactic plane, which we estimate at $\sim -20$ \kmspc.
The most unexpected and unexplained term within the Ogorodnikov-Milne model is
the first-degree magnetic harmonic representing a rigid rotation of the stellar
field about the axis $-Y$ pointing opposite to the direction of rotation. This
harmonic comes out with a statistically robust coefficient $6.2 \pm 0.9$
\kmspc, and is also present in the velocity field of more distant stars. The
ensuing upward vertical motion of stars in the general direction of the
Galactic center and the downward motion in the anticenter direction are
opposite to the vector field expected from the stationary Galactic warp model.


title: Atomtronic circuits of diodes and transistors

abstract:
  We illustrate that open quantum systems composed of neutral, ultracold atoms
in one-dimensional optical lattices can exhibit behavior analogous to
semiconductor electronic circuits. A correspondence is demonstrated for bosonic
atoms, and the experimental requirements to realize these devices are
established. The analysis follows from a derivation of a quantum master
equation for this general class of open quantum systems.


title: Age constraints in the double pulsar system J0737-3039

abstract:
  We investigate the age constraints that can be placed on the double pulsar
system using models for the spin-down of the first-born 22.7-ms pulsar A and
the 2.77-s pulsar B with characteristic ages of 210 and 50 Myr respectively.
Standard models assuming dipolar spin-down of both pulsars suggest that the
time since the formation of B is ~50 Myr, i.e. close to B's characteristic age.
However, adopting models which account for the impact of A's relativistic wind
on B's spin-down we find that the formation of B took place either 80 or 180
Myr ago, depending the interaction mechanism. Formation 80 Myr ago, closer to
B's characteristic age, would result in the contribution from J0737-3039 to the
inferred coalescence rates for double neutron star binaries increasing by 40%.
The 180 Myr age is closer to A's characteristic age and would be consistent
with the most recent estimates of the coalescence rate. The new age constraints
do not significantly impact recent estimates of the kick velocity, tilt angle
between pre and post-supernova orbital planes or pre-supernova mass of B's
progenitor.


title: The absorption theorem for affable equivalence relations

abstract:
  We prove a result about extension of a minimal AF-equivalence relation R on
the Cantor set X, the extension being `small' in the sense that we modify R on
a thin closed subset Y of X. We show that the resulting extended equivalence
relation S is orbit equivalent to the original R, and so, in particular, S is
affable. Even in the simplest case--when Y is a finite set--this result is
highly non-trivial. The result itself--called the absorption theorem--is a
powerful and crucial tool for the study of the orbit structure of minimal
Z^n-actions on the Cantor set [GMPS]. The absorption theorem is a significant
generalization of the main theorem proved in [GPS2]. However, we shall need a
few key results from [GPS2] in order to prove the absorption theorem.


title: Billiards in L-shaped tables with barriers

abstract:
  We compute the volumes of the eigenform loci in the moduli space of genus two
Abelian differentials. From this, we obtain asymptotic formulas for counting
closed billiards paths in certain L-shaped polygons with barriers.


title: The LISA Gravitational Wave Foreground: A Study of Double White Dwarfs

abstract:
  Double white dwarfs are expected to be a source of confusion-limited noise
for the future gravitational wave observatory LISA. In a specific frequency
range, this 'foreground noise' is predicted to rise above the instrumental
noise and hinder the detection of other types of signals, e.g., gravitational
waves arising from stellar mass objects inspiraling into massive black holes.
In many previous studies only detached populations of compact object binaries
have been considered in estimating the LISA gravitational wave foreground
signal. Here, we investigate the influence of compact object detached and
Roche-Lobe Overflow Galactic binaries on the shape and strength of the LISA
signal. Since >99% of remnant binaries which have orbital periods within the
LISA sensitivity range are white dwarf binaries, we consider only these
binaries when calculating the LISA signal. We find that the contribution of
RLOF binaries to the foreground noise is negligible at low frequencies, but
becomes significant at higher frequencies, pushing the frequency at which the
foreground noise drops below the instrumental noise to >6 mHz. We find that it
is important to consider the population of mass transferring binaries in order
to obtain an accurate assessment of the foreground noise on the LISA data
stream. However, we estimate that there still exists a sizeable number (~11300)
of Galactic double white dwarf binaries which will have a signal-to-noise ratio
>5, and thus will be potentially resolvable with LISA. We present the LISA
gravitational wave signal from the Galactic population of white dwarf binaries,
show the most important formation channels contributing to the LISA disc and
bulge populations and discuss the implications of these new findings.


title: Birkhoff billiards are insecure

abstract:
  We prove that every compact plane billiard, bounded by a smooth curve, is
insecure: there exist pairs of points $A,B$ such that no finite set of points
can block all billiard trajectories from $A$ to $B$.


title:
Self-Similar Evolution of Cosmic-Ray-Modified Quasi-Parallel Plane
  Shocks

abstract:
  Using an improved version of the previously introduced CRASH (Cosmic Ray
Acceleration SHock) code, we have calculated the time evolution of cosmic-ray
(CR) modified quasi-parallel plane shocks for Bohm-like diffusion, including
self-consistent models of Alfven wave drift and dissipation, along with thermal
leakage injection of CRs. The new simulations follow evolution of the CR
distribution to much higher energies than our previous study, providing a
better examination of evolutionary and asymptotic behaviors. The postshock CR
pressure becomes constant after quick initial adjustment, since the evolution
of the CR partial pressure expressed in terms of a momentum similarity variable
is self-similar. The shock precursor, which scales as the diffusion length of
the highest energy CRs, subsequently broadens approximately linearly with time,
independent of diffusion model, so long as CRs continue to be accelerated to
ever-higher energies. This means the nonlinear shock structure can be described
approximately in terms of the similarity variable, x/(u_s t), where u_s is the
shock speed once the postshock pressure reaches an approximate time asymptotic
state. As before, the shock Mach number is the key parameter determining the
evolution and the CR acceleration efficiency, although finite Alfven wave drift
and wave energy dissipation in the shock precursor reduce the effective
velocity change experienced by CRs, so reduce acceleration efficiency
noticeably, thus, providing a second important parameter at low and moderate
Mach numbers.


title: Quantum doubles of certain rank two pointed Hopf algebras

abstract:
  A certain class of rank two pointed Hopf algebras is considered. The simple
modules of their Drinfel'd double is described using Radford's method
\cite{rad}. The socle of the tensor product of two such modules is computed and
a formula similar to the one in \cite{one} is obtained in some conditions.
Cases when such a tensor product is completely irreducible are also given in
the last section.


title: Controllable dynamics of two separate qubits in Bell states

abstract:
  The dynamics of entanglement and fidelity for a subsystem of two separate
spin-1/2 qubits prepared in Bell states is investigated. One of the subsystem
qubit labelled $A$ is under the influence of a Heisenberg XY spin-bath, while
another one labelled $B$ is uncoupled with that. We discuss two cases: (i) the
number of bath spins $N\to\infty$; (ii) $N$ is finite: N=40. In both cases, the
bath is initially prepared in a thermal equilibrium state. It is shown that the
time dependence of the concurrence and the fidelity of the two subsystem qubits
can be controlled by tuning the parameters of the spin-bath, such as the
anisotropic parameter, the temperature and the coupling strength with qubit
$A$. It is interesting to find the dynamics of the concurrence is independent
of four different initial Bell states and that of the fidelity is divided into
two groups.


title: Inflation in a Symmetric Vacuum

abstract:
  If in a finite universe, the tree-level vacuum is a symmetric superposition
of coherent states, in each of which the inflaton field assumes a different,
energy-minimizing mean value (vev), then the resulting energy is positive and
decreases exponentially as the volume of the universe increases. This effect
can drive inflation when that volume is small and explain part of dark energy
when it is big, but the effect is exceedingly tiny except at very early times.


title: On the Thermal Symmetry of the Markovian Master Equation

abstract:
  The quantum Markovian master equation of the reduced dynamics of a harmonic
oscillator coupled to a thermal reservoir is shown to possess thermal symmetry.
This symmetry is revealed by a Bogoliubov transformation that can be
represented by a hyperbolic rotation acting on the Liouville space of the
reduced dynamics. The Liouville space is obtained as an extension of the
Hilbert space through the introduction of tilde variables used in the
thermofield dynamics formalism. The angle of rotation depends on the
temperature of the reservoir, as well as the value of Planck's constant. This
symmetry relates the thermal states of the system at any two temperatures. This
includes absolute zero, at which purely quantum effects are revealed. The
Caldeira-Leggett equation and the classical Fokker-Planck equation also possess
thermal symmetry. We compare the thermal symmetry obtained from the Bogoliubov
transformation in related fields and discuss the effects of the symmetry on the
shape of a Gaussian wave packet.


title: The Decay Omega^- -> Xi^- pi^+ pi^- in Chiral Perturbation Theory

abstract:
  We study the decay Omega^- -> Xi^- pi^+ pi^- in heavy-baryon chiral
perturbation theory. At leading order, the decay is completely dominated by the
Xi^{*0}(1530) intermediate state, and the predicted rate and Xi^-pi^+ mass
distribution are in conflict with currently available data. It is possible to
resolve this conflict by considering additional contributions at
next-to-leading order.


title: Generalized CCR Flows

abstract:
  We introduce a new construction of $E_0$-semigroups, called generalized CCR
flows, with two kinds of descriptions: those arising from sum systems and those
arising from pairs of $C_0$-semigroups. We get a new necessary and sufficient
condition for them to be of type III, when the associated sum system is of
finite index. Using this criterion, we construct examples of type III
$E_0$-semigroups, which can not be distinguished from $E_0$-semigroups of type
I by the invariants introduced by Boris Tsirelson. Finally, by considering the
local von Neumann algebras, and by associating a type III factor to a given
type III $E_0$-semigroup, we show that there exist uncountably many type III
$E_0$-semigroups in this family, which are mutually non-cocycle conjugate.


title: Del Pezzo singularities and SUSY breaking

abstract:
  An analytic construction of compact Calabi-Yau manifolds with del Pezzo
singularities is found. We present complete intersection CY manifolds for all
del Pezzo singularities and study the complex deformations of these
singularities. An example of the quintic CY manifold with del Pezzo 6
singularity and some number of conifold singularities is studied in details.
The possibilities for the 'geometric' and ISS mechanisms of dynamical SUSY
breaking are discussed. As an example, we construct the ISS vacuum for the del
Pezzo 6 singularity.


title: Infinitesimal spectral flow and scattering matrix

abstract:
  In this note the notion of infinitesimal scattering matrix is introduced. It
is shown that under certain assumption, the scattering operator of a pair of
trace compatible operators is equal to the chronological exponential of the
infinitesimal scattering matrix and that the trace of the infinitesimal
scattering matrix is equal to the absolutely continuous part of the
infinitesimal spectral flow. As a corollary, a variant of the Birman-Krein
formula is derived. An interpretation of Pushnitski's $\mu$-invariant is given.


title:
Actions of symbolic dynamical systems on $C^*$-algebras II. Simplicity
  of $C^*$-symbolic crossed products and some examples

abstract:
  We have introduced a notion of $C^*$-symbolic dynamical system in [K.
Matsumoto: Actions of symbolic dynamical systems on $C^*$-algebras, to appear
in J. Reine Angew. Math.], that is a finite family of endomorphisms of a
$C^*$-algebra with some conditions. The endomorphisms are indexed by symbols
and yield both a subshift and a $C^*$-algebra of a Hilbert $C^*$-bimodule. The
associated $C^*$-algebra with the $C^*$-symbolic dynamical system is regarded
as a crossed product by the subshift. We will study a simplicity condition of
the $C^*$-algebras of the $C^*$-symbolic dynamical systems. Some examples such
as irrational rotation Cuntz-Krieger algebras will be studied.


title: On a mathematical frame of reference

abstract:
  This papers aims at revisiting Minkowski space-time with a modified outlook
and making it more consistent (III.8). The paper scrutinizes the special case
of relativistic hypothesis (STR). The paper tries to solve the problems faced
by relativistic hypothesis by proposing a purely mathematically formulated
reference (and not a frame like aether) frame that suits string theory. Then
checking the validity of the frame by applying to various phenomenon and
aspects explained by STR; and also its properties when the experimental
statistics are taken into account in a homogeneous and isotropic large scale
structure of Universe. Further more the paper checks whether introducing the
frame solves the problems in STR; then looks into the occurrences of new
paradoxes in the frame, if any present.


title:
Tilt-angle landscapes and temperature dependence of the conductance in
  biphenyl-dithiol single-molecule junctions

abstract:
  Using a density-functional-based transport method we study the conduction
properties of several biphenyl-derived dithiol (BPDDT) molecules wired to gold
electrodes. The BPDDT molecules differ in their side groups, which control the
degree of conjugation of the pi-electron system. We have analyzed the
dependence of the low-bias zero-temperature conductance on the tilt angle phi
between the two phenyl ring units, and find that it follows closely a
cos^2(phi) law, as expected from an effective pi-orbital coupling model. We
show that the tilting of the phenyl rings results in a decrease of the
zero-temperature conductance by roughly two orders of magnitude, when going
from a planar conformation to a configuration in which the rings are
perpendicular. In addition we demonstrate that the side groups, apart from
determining phi, have no influence on the conductance. All this is in agreement
with the recent experiment by Venkataraman et al. [Nature 442, 904 (2006)].
Finally, we study the temperature dependence of both the conductance and its
fluctuations and find qualitative differences between the examined molecules.
In this analysis we consider two contributions to the temperature behavior, one
coming from the Fermi functions and the other one from a thermal average over
different contact configurations. We illustrate that the fluctuations of the
conductance due to temperature-induced changes in the geometric structure of
the molecule can be reduced by an appropriate design.


title: Particle Ratios on the Near and Away-Side of Jets at RHIC

abstract:
  We measure the relative abundances of strange mesons, baryons, and
anti-baryons correlated with high-$p_T$ trigger particles in $^{197}$Au +
$^{197}$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. Particle yields and ratios
are extracted on the near-side and away-side of the trigger particle. The
associate-particle ratios are studied as a function of the angle relative to
the trigger particle azimuth $\Delta\phi$. Such studies should help elucidate
the origin of the previously observed correlations and their strong
modifications in Au+Au collisions relative to p+p collisions. We discuss how
these measurements might be related to several scenarios for interactions of
fast partons with the medium in Au+Au collision.


title: The Lee-Wick Fields out of Gravity

abstract:
  We study the Maxwell-Einstein theory in the framework of effective field
theories. We show that the modified one-loop renormalizable Lagrangian due to
quantum gravitational effects contains a Lee-Wick vector field as an extra
degree of freedom in the theory. Thus gravity provides a natural mechanism for
the emergence of this exotic particle.


title:
Systematic Errors in the Hubble Constant Measurement from the
  Sunyaev-Zel'dovich effect

abstract:
  The Hubble constant estimated from the combined analysis of the
Sunyaev-Zel'dovich effect and X-ray observations of galaxy clusters is
systematically lower than those from other methods by 10-15 percent. We examine
the origin of the systematic underestimate using an analytic model of the
intracluster medium (ICM), and compare the prediction with idealistic triaxial
models and with clusters extracted from cosmological hydrodynamical
simulations. We identify three important sources for the systematic errors;
density and temperature inhomogeneities in the ICM, departures from
isothermality, and asphericity. In particular, the combination of the first two
leads to the systematic underestimate of the ICM spectroscopic temperature
relative to its emission-weighed one. We find that these three systematics well
reproduce both the observed bias and the intrinsic dispersions of the Hubble
constant estimated from the Sunyaev-Zel'dovich effect.


title: Helium abundance in galaxy clusters and Sunyaev-Zeldovich effect

abstract:
  It has long been suggested that helium nuclei in the intracluster plasma can
sediment in the cluster gravitational potential well. Some theoretical
estimates for the cores of relaxed clusters predict an excess of helium
abundance by up to a factor of a few over its primordial value. The
intracluster helium abundance cannot be measured directly. This presents a
significant source of uncertainty for cosmological tests based on the X-ray
derived cluster quantities, such as the gas mass, total mass, and gas mass
fraction, all of which depend on the assumed helium abundance. We point out
that cluster distances derived by combining the Sunyaev-Zeldovich (SZ) and
X-ray data also depend on the helium abundance. This dependence can be used to
measure the abundance, provided the distance is known independently. For
example, if one adopts the WMAP H_0 value, then the recent H_0 measurement by
Bonamente and collaborators, derived from SZ data on 38 clusters assuming a
primordial helium abundance, corresponds to an abundance excess by a factor of
1.9+-0.8 within r~1 Mpc (using only their statistical errors). This shows that
interesting accuracy is within reach. We also briefly discuss how the SZ and
X-ray cluster data can be combined to resolve the helium abundance dependence
for the d_a(z) cosmological test.

categories: astro-ph astro-ph.CO astro-ph.HE astro-ph.IM


title:
Neutrino Mass Matrix from Seesaw Mechanism Subjected to Texture Zero and
  Invariant Under a Cyclic Permutation

abstract:
  We evaluate the predictive power of the neutrino mass matrices arising from
seesaw mechanism subjected to texture zero and satisfying a cyclic permutation
invariant. We found that only two from eight possible patterns of the neutrino
mass matrices are invariant under a cyclic permutation. The two resulted
neutrino mass matrices which are invariant under a cyclic permutation can be
used qualitatively to explain the neutrino mixing phenomena for solar neutrino
and to derive the mixing angle that agress with the experimental data.


title: Instanton Solution in Tachyon Cosmology

abstract:
  We find an exact classical solution in Euclidean gravity coupled to a scalar
field with a particular form of potential commonly used in tachyon cosmology.
This solution represents a tunneling between two vacua.


title:
Gauge Invariant Exact Renormalization Group and Perfect Actions in the
  Open Bosonic String Theory

abstract:
  The exact renormalization group is applied to the world sheet theory
describing bosonic open string backgrounds to obtain the equations of motion
for the fields of the open string. Using loop variable techniques the equations
can be constructed to be gauge invariant. Furthermore they are valid off the
(free) mass shell. This requires keeping a finite cutoff. Thus we have the
interesting situation of a scale invariant world sheet theory with a finite
world sheet cutoff. This is possible because there are an infinite number of
operators whose coefficients can be tuned. This is in the same sense that
"perfect actions" or "improved actions" have been proposed in lattice gauge
theory to reproduce the continuum results even while keeping a finite lattice
spacing.


title:
Statistical analyses of long-term variability of AGN at high radio
  frequencies

abstract:
  We present a study of variability time scales in a large sample of Active
Galactic Nuclei at several frequencies between 4.8 and 230 GHz. We investigate
the differences of various AGN types and frequencies and correlate the measured
time scales with physical parameters such as the luminosity and the Lorentz
factor. Our sample consists of both high and low polarization quasars, BL
Lacertae objects and radio galaxies. The basis of this work is the 22 GHz, 37
GHz and 87 GHz monitoring data from the Metsahovi Radio Observatory spanning
over 25 years. In addition,we used higher 90 GHz and 230 GHz frequency data
obtained with the SEST-telescope between 1987 and 2003. Further lower frequency
data at 4.8 GHz, 8 GHz and 14.5 GHz from the University of Michigan monitoring
programme have been used. We have applied three different statistical methods
to study the time scales: The structure function, the discrete correlation
function and the Lomb-Scargle periodogram. We discuss also the differences and
relative merits of these three methods. Our study reveals that smaller flux
density variations occur in these sources on short time scales of 1-2 years,
but larger outbursts happen quite rarely, on the average only once in every 6
years. We do not find any significant differences in the time scales between
the source classes. The time scales are also only weakly related to the
luminosity suggesting that the shock formation is caused by jet instabilities
rather than the central black hole.


title: Shear-Induced Chaos

abstract:
  Guided by a geometric understanding developed in earlier works of Wang and
Young, we carry out some numerical studies of shear-induced chaos. The settings
considered include periodic kicking of limit cycles, random kicks at Poisson
times, and continuous-time driving by white noise. The forcing of a
quasi-periodic model describing two coupled oscillators is also investigated.
In all cases, positive Lyapunov exponents are found in suitable parameter
ranges when the forcing is suitably directed.


title:
Computer simulation of model cohesive powders: influence of assembling
  procedure and contact laws on low consolidation states

abstract:
  The structure and mechanical properties of a simple two-dimensional model of
a cohesive powder are investigated by molecular dynamics simulations.
Micromechanical ingredients involve elasticity, friction, a short range
attraction and, possibly, rolling resistance (RR) in contacts. The
microstructure of the cohesive packing varies according to the assembling
procedure, from rather densely packed if isolated particles are directly
compressed to much looser if the formation of large aggregates is allowed prior
to compression. A crucial parameter is the ratio P*= Pa/F0 of applied pressure
P, acting on grains of diameter $a$, to maximum tensile contact force F0. At
low P* the final structure depends on the level of velocity fluctuations at the
early stages of cluster aggregation. With RR the coordination number approaches
2 in the limit of low initial velocities or large rolling friction. The force
network generally comprises small hyperstatic clusters with forces of the order
of F0, joined by nearly unstressed, barely rigid arms. As P* grows, it quickly
rearranges into force chain-like patterns. Density correlations witness a
fractal structure, with dimension Df, up to some density-dependent blob size.
WIth RR Df coincides with the ballistic aggregation result, despite a possibly
different connectivity. Possible effects of some parameters on material
strength are evoked.


title:
Dielectrophoresis model for the colossal electroresistance of
  phase-separated manganites

abstract:
  We propose a dielectrophoresis model for phase-separated manganites. Without
increase of the fraction of metallic phase, an insulator-metal transition
occurs when a uniform electric field applied across the system exceeds a
threshold value. Driven by the dielectrophoretic force, the metallic clusters
reconfigure themselves into stripes along the direction of electric field,
leading to the filamentous percolation. This process, which is time-dependent,
irreversible and anisotropic, is a probable origin of the colossal
electroresistance in manganites.


title:
Axial $N\to \Delta(1232)$ and $N \to N^{\star}(1440)$ transition form
  factors

abstract:
  We calculate the axial $N\to \Delta(1232)$ and $N\to N^{\star}(1440)$
transition form factors in a chiral constituent quark model. As required by the
partial conservation of axial current ($PCAC$) condition, we include one- and
two-body axial exchange currents. For the axial $N\to \Delta(1232)$ form
factors we compare with previous quark model calculations that use only
one-body axial currents, and with experimental analyses. The paper provides the
first calculation of all weak axial $N\to N^{\star}(1440)$ form factors. Our
main result is that exchange currents are very important for certain axial
transition form factors. In addition to improving our understanding of nucleon
structure, the present results are relevant for neutrino-nucleus scattering
cross section predictions needed in the analysis of neutrino mixing
experiments.


title:
Bogoliubov spectrum of a cigar shaped Fermi superfluid in an optical
  lattice at the BEC-BCS crossover

abstract:
  We study the Bogoliubov spectrum of an elongated Fermi superfluid confined in
an one-dimensional superfluid along the Bose-Einstein-condensate
(BEC)-Bardeen-Cooper-Schrieffer (BCS) crossover. We derive analytic expressions
for the sound velocity, effective mass and the Bogoliubov excitation spectrum
of the axial quasiparticles long the crossover based on the hydrodynamic
theory. Our investigation reveal interesting signatures of BEC-BCS crossover in
an optical lattice which deserve experimental investigation.


title:
Role of long range ferromagnetic order in the electronic structure of
  Sr$_{1-x}$Ca$_x$RuO$_3$

abstract:
  We investigate the role of long range ferromagnetic order in the electronic
structure of Sr$_{1-x}$Ca$_x$RuO$_3$ using high resolution photoemission
spectroscopy. SrRuO$_3$ is a ferromagnetic metal but isostructural,
isoelectronic CaRuO$_3$ is an enhanced paramagnet. Surface spectra of CaRuO$_3$
exhibit temperature induced modifications. This is not significant in other
compositions. This may be attributed to the structural changes observed in
previous studies. Interestingly, the bulk spectra reveal unusual spectral
changes exhibiting large decrease in the coherent feature intensity
corresponding to only ferromagnetic samples, although the Ru moment is very
similar in all the compositions.


title: Observational Characteristics of the First Protostellar Cores

abstract:
  First protostellar cores are young stellar objects in the earliest
evolutionary stage. They are hydrostatic objects formed soon after the central
portions of star-forming cores become optically thick to dust emission. We
consider their characteristics in the emitted radiation, and discuss their
evolution with increasing mass of the cores. Particular attention is paid to
detailed radiative and chemical processes in the postshock relaxation layer
located at the surface of the core, where the majority of radiation is emitted.
Most of the radiation is originally emitted in the dust continuum in
mid-infrared wavelength (~10-30 micron), which reprocessed to far-infrared with
~100-200 micron. Although some fraction (~0.1) of the radiation energy is
emitted in the H2O lines at the accretion shock, most is absorbed and reemitted
in the dust continuum in the envelope. The H2O lines account for at most ~1/100
of the observed luminosity. If a cavity is present in the envelope due to
outflow or rotation, the dust and H2O line emission in the mid-infrared
wavelength from the shock can be observed directly, or as a reflection nebula.
Among forthcoming observational facillities, SPICA is the most suitable for
detecting either direct or processed radiation from first-core objects.


title:
Positivity and almost positivity of biharmonic Green's functions under
  Dirichlet boundary conditions

abstract:
  In general, for higher order elliptic equations and boundary value problems
like the biharmonic equation and the linear clamped plate boundary value
problem neither a maximum principle nor a comparison principle or --
equivalently -- a positivity preserving property is available. The problem is
rather involved since the clamped boundary conditions prevent the boundary
value problem {from} being reasonably written as a system of second order
boundary value problems.
  It is shown that, on the other hand, for bounded smooth domains $\Omega
\subset\mathbb{R}^n$, the negative part of the corresponding Green's function
is "small" when compared with its singular positive part, provided $n\ge 3$.
  Moreover, the biharmonic Green's function in balls $B\subset\mathbb{R}^n$
under Dirichlet (i.e. clamped) boundary conditions is known explicitly and is
positive. It has been known for some time that positivity is preserved under
small regular perturbations of the domain, if $n=2$. In the present paper, such
a stability result is proved for $n\ge 3$. Keywords: Biharmonic Green's
functions, positivity, almost positivity, blow-up procedure.


title: Modeling many-particle mechanical effects of an interacting Rydberg gas

abstract:
  In a recent work [Phys. Rev. Lett. 98, 023004 (2007)] we have investigated
the influence of attractive van der Waals interaction on the pair distribution
and Penning ionization dynamics of ultracold Rydberg gases. Here we extend this
description to atoms initially prepared in Rydberg states exhibiting repulsive
interaction. We present calculations based on a Monte Carlo algorithm to
simulate the dynamics of many atoms under the influence of both repulsive and
attractive longrange interatomic forces. Redistribution to nearby states
induced by black body radiation is taken into account, changing the effective
interaction potentials. The model agrees with experimental observations, where
the ionization rate is found to increase when the excitation laser is
blue-detuned from the atomic resonance.


title:
Adsorption and grafting on colloidal interfaces studied by scattering
  techniques

abstract:
  The adsorption of polymer and surfactant molecules onto colloidal particles
or droplets in solution can be characterized non-destructively by scattering
techniques. In a first part, the general framework of Dynamic Light Scattering,
Small Angle Neutron and X-ray Scattering for the determination of the structure
of adsorbed layers, and namely of the density profile, is presented. We then
review recent studies of layers of the model polymer poly(ethylene oxide), as
homopolymer or part of a block copolymer. In this field, scattering with
contrast variation has been shown to be a powerful tool to obtain a detailed
description of the layer structure. Adsorption of chemically more complex
systems, including polyelectrolytes, polymer complexes, grafted chains and
biomacromolecules are also discussed in this review, as well as surfactant
adsorption.


title: Higher order intertwining approach to quasinormal modes

abstract:
  Using higher order intertwining operators we obtain new exactly solvable
potentials admitting quasinormal mode (QNMs) solutions of the Klein-Gordon
equation. It is also shown that different potentials exhibiting QNMs can be
related through nonlinear supersymmetry.


title: Diffusion constants and martingales for senile random walks

abstract:
  We derive diffusion constants and martingales for senile random walks with
the help of a time-change. We provide direct computations of the diffusion
constants for the time-changed walks. Alternatively, the values of these
constants can be derived from martingales associated with the time-changed
walks. Using an inverse time-change, the diffusion constants for senile random
walks are then obtained via these martingales. When the walks are diffusive,
weak convergence to Brownian motion can be shown using a martingale functional
limit theorem.


title: CPT and Lorentz violation effects in hydrogen-like atoms

abstract:
  Within the framework of Lorentz-violating extended electrodynamics, the Dirac
equation for a bound electron in an external electromagnetic field is
considered assuming the interaction with a CPT-odd axial vector background
$b_\mu$. The quasi-relativistic Hamiltonian is obtained using a $1/c$-series
expansion. Relativistic Dirac eigenstates in a spherically-symmetric potential
are found accurate up to the second order in $b_0$. $b_0$-induced CPT-odd
corrections to the electromagnetic dipole moment operators of a bound electron
are calculated that contribute to the anapole moment of the atomic orbital and
may cause a specific asymmetry of the angular distribution of the radiation of
a hydrogen atom.


title: Coulomb dissociation, a tool for nuclear astrophysics

abstract:
  A short status report on Coulomb dissociation, an indirect method for nuclear
astrophysics is given. An analytically solvable approach to study
electromagnetic excitation in ^{11}Be, the archetype of a halo nucleus, is
proposed.


title: Sparsity oracle inequalities for the Lasso

abstract:
  This paper studies oracle properties of $\ell_1$-penalized least squares in
nonparametric regression setting with random design. We show that the penalized
least squares estimator satisfies sparsity oracle inequalities, i.e., bounds in
terms of the number of non-zero components of the oracle vector. The results
are valid even when the dimension of the model is (much) larger than the sample
size and the regression matrix is not positive definite. They can be applied to
high-dimensional linear regression, to nonparametric adaptive regression
estimation and to the problem of aggregation of arbitrary estimators.


title:
Microscopic properties of vortex state in YB6 probed by muon spin
  rotation

abstract:
  Local magnetic field distribution B(r) in the mixed state of a boride
superconductor, YB6, is studied by muon spin rotation (muSR). A comparative
analysis using the modified London model and Ginzburg-Landau (GL) model
indicates that the GL model exhibits better agreement with muSR data at higher
fields, thereby demonstrating the importance of reproducing the field profile
near the vortex cores when the intervortex distance becomes closer to the GL
coherence length. The temperature and field dependence of magnetic penetration
depth ($\lambda$) does not show any hint of nonlocal effect nor of low-lying
quasiparticle excitation. This suggests that the strong coupling of electrons
to the rattling motion of Y ions in the boron cage suggested by bulk
measurements gives rise to a conventional superconductivity with isotropic
s-wave pairing. Taking account of the present result, a review is provided for
probing the anisotropy of superconducting order parameters by the slope of
$\lambda$ against field.


title: Probabilita` e Paradosso (Probability and Paradox)

abstract:
  In this paper we present three simple applications of probability and
highlight and discuss their paradoxical flavour.


title: Weak decays of 4He-Lambda

abstract:
  We measured the lifetime and the mesonic and non-mesonic decay rates of the
4He-Lambda hypernucleus. The hypernuclei were created using a 750 MeV/c
momentum K- beam on a liquid 4He target by the reaction 4He(K-,pi-)4He-Lambda.
The 4He-Lambda lifetime was directly measured using protons from Lambda p -> n
p non-mesonic decay (also referred to as proton-stimulated decay) and was found
to have a value of tau = 245 +/- 24 ps. The mesonic decay rates were determined
from the observed numbers of pi-'s and pi0's as Gamma_pi-/Gamma_tot = 0.270 +/-
0.024 and Gamma_pi0/Gamma_tot = 0.564 +/- 0.036, respectively, and the values
of the proton- and neutron-stimulated decay rates were extracted as
Gamma_p/Gamma_tot = 0.169 +/- 0.019 and Gamma_n/Gamma_tot <= 0.032 (95% CL),
respectively. The effects of final-state interactions and possible 3-body
Lambda N N decay contributions were studied in the context of a simple model of
nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and
were used in the determination of the non-mesonic branching fractions. The
implications of the results of this analysis were considered for the empirical
Delta I = 1/2 rule and the decay rates of the 4H-Lambda hypernucleus.


title:
Boson decay and the dynamical structure factor for the XXZ chain at
  finite magnetic field

abstract:
  We study the longitudinal dynamical structure factor $S^{zz}(q,\omega)$ for
the anisotropic spin-1/2 (XXZ) chain at finite magnetic field using
bosonization. The leading irrelevant operators in the effective bosonic model
stemming from band curvature describe boson decay processes and lead to a
high-frequency tail and a finite width $\gamma_q$ of the on-shell peak for
$S^{zz}(q,\omega)$. We use the Bethe ansatz to show that $\gamma_q\sim q^2$ for
$q\ll 1$ and to calculate the amplitudes of the leading irrelevant operators in
the effective field theory.


title: IRAS 18511+0146: a proto Herbig Ae/Be cluster?

abstract:
  Context: The evolution of a young protocluster depends on the relative
spatial distributions and dynamics of both stars and gas. Aims: We study the
distribution and properties of the gas and stars surrounding the luminous (10^4
L_sun) protocluster IRAS 18511+0146. Methods: IRAS 18511+0146 and the cluster
associated with it has been investigated using the sub-millimetre (JCMT-SCUBA),
infrared (Spitzer-MIPSGAL, Spitzer-GLIMPSE, Palomar) and radio (VLA) continuum
data. Cluster simulations have been carried out in order to understand the
properties of clusters as well as to compare with the observations. Results:
The central most obscured part of the protocluster coincident with the compact
sub-millimetre source found with SCUBA is responsible for at least 2/3 of the
total luminosity. A number of cluster members have been identified which are
bright in mid infrared and show rising (near to mid infrared) spectral energy
distributions suggesting that these are very young stellar sources. In the mid
infrared 8.0 micron image, a number of filamentary structures and clumps are
detected in the vicinity of IRAS 18511+0146. Conclusions: Based on the
luminosity and cluster size as well as on the evolutionary stages of the
cluster members, IRAS 18511+0146 is likely to be protocluster with the most
massive object being a precursor to a Herbig type star.


title:
Location, correlation, radiation: where is the $\sigma$, what is its
  structure and what is its coupling to photons?

abstract:
  Scalar mesons are a key expression of the infrared regime of QCD. The
lightest of these is the $\sigma$. Now that its pole in the complex energy
plane has been precisely located, we can ask whether this state is transiently
${\bar q}q$ or ${\bar {qq}} qq$ or a multi-meson molecule or largely glue? The
two photon decay of the $\sigma$ can, in principle, discriminate between these
possibilities. We review here how the $\gamma\gamma\to\pi^+\pi^-$, $\pi^0\pi^0$
cross-sections can be accurately computed. The result not only agrees with
experiment, but definitively fixes the radiative coupling of the $\sigma$. This
equates to a two photon width of $(4.1 \pm 0.3)$ keV, which accords with the
simple non-relativistic quark model expectation for a ${\bar u}u, {\bar d}d$
scalar. Nevertheless, robust predictions from relativistic strong coupling QCD
are required for each of the possible compositions before we can be sure which
one really delivers the determined $\gamma\gamma$ coupling.


title:
Suppression of correlated electron escape in double ionization in strong
  laser fields

abstract:
  The effect of the Pauli exclusion principle on double ionization of He atoms
by strong, linearly polarized laser pulses is analyzed. We show that correlated
electron escape, with electron momenta symmetric with respect to the field
polarization axis, is suppressed if atoms are initially prepared in the
metastable state 3S. The effect is a consequence of selection rules for the
transition to the appropriate outgoing two-electron states. We illustrate the
suppression in numerical calculations of electron and ion momentum
distributions within a reduced dimensionality model.


title:
Acyclicity of Preferences, Nash Equilibria, and Subgame Perfect
  Equilibria: a Formal and Constructive Equivalence

abstract:
  In 1953, Kuhn showed that every sequential game has a Nash equilibrium by
showing that a procedure, named ``backward induction'' in game theory, yields a
Nash equilibrium. It actually yields Nash equilibria that define a proper
subclass of Nash equilibria. In 1965, Selten named this proper subclass subgame
perfect equilibria. In game theory, payoffs are rewards usually granted at the
end of a game. Although traditional game theory mainly focuses on real-valued
payoffs that are implicitly ordered by the usual total order over the reals,
works of Simon or Blackwell already involved partially ordered payoffs. This
paper generalises the notion of sequential game by replacing real-valued payoff
functions with abstract atomic objects, called outcomes, and by replacing the
usual total order over the reals with arbitrary binary relations over outcomes,
called preferences. This introduces a general abstract formalism where Nash
equilibrium, subgame perfect equilibrium, and ``backward induction'' can still
be defined. This paper proves that the following three propositions are
equivalent: 1) Preferences over the outcomes are acyclic. 2) Every sequential
game has a Nash equilibrium. 3) Every sequential game has a subgame perfect
equilibrium. The result is fully computer-certified using Coq. Beside the
additional guarantee of correctness, the activity of formalisation using Coq
also helps clearly identify the useful definitions and the main articulations
of the proof.


title:
Transport coefficients of dissipative particle dynamics with finite time
  step

abstract:
  The viscosity and self-diffusion constant of a mesoscale hydrodynamic method,
dissipative particle dynamics (DPD), are investigated. The viscosity of DPD
with finite time step, including the Lowe-Anderson thermostat, is derived
analytically for the ideal-gas equation of state and phenomenologically for
systems with soft repulsive potentials. The results agree well with numerical
data. The scaling of the local relative velocity in molecular dynamics
simulations is shown to be useful to obtain faster diffusion than for the DPD
thermostat.


title: Orbital order in degenerate Hubbard models : A variational study

abstract:
  We use the Gutzwiller variational many-body theory to investigate the
stability of orbitally ordered states in a two-band Hubbard-model without spin
degrees of freedom. Our results differ significantly from earlier Hartree-Fock
calculations for this model. The Hartree-Fock phase diagram displays a large
variety of orbital orders. In contrast, in the Gutzwiller approach orbital
order only appears for densities in a narrow region around half filling.


title: Detecting anchoring in financial markets

abstract:
  Anchoring is a term used in psychology to describe the common human tendency
to rely too heavily (anchor) on one piece of information when making decisions.
A trading algorithm inspired by biological motors, introduced by L.
Gil\cite{Gil}, is suggested as a testing ground for anchoring in financial
markets. An exact solution of the algorithm is presented for arbitrary price
distributions. Furthermore the algorithm is extended to cover the case of a
market neutral portfolio, revealing additional evidence that anchoring is
involved in the decision making of market participants. The exposure of
arbitrage possibilities created by anchoring gives yet another illustration on
the difficulty proving market efficiency by only considering lower order
correlations in past price time series


title: The CFT dual of AdS gravity with torsion

abstract:
  We consider the Mielke-Baekler model of three-dimensional AdS gravity with
torsion, which has gravitational and translational Chern-Simons terms in
addition to the usual Einstein-Hilbert action with cosmological constant. It is
shown that the topological nature of the model leads to a finite
Fefferman-Graham expansion. We derive the holographic stress tensor and the
associated Ward identities and show that, due to the asymmetry of the left- and
right-moving central charges, a Lorentz anomaly appears in the dual conformal
field theory. Both the consistent and the covariant Weyl and Lorentz anomaly
are determined, and the Wess-Zumino consistency conditions for the former are
verified. Moreover we consider the most general solution with flat boundary
geometry, which describes left-and right-moving gravitational waves on AdS_3
with torsion, and shew that in this case the holographic energy-momentum tensor
is given by the wave profiles. The anomalous transformation laws of the wave
profiles under diffeomorphisms preserving the asymptotic form of the bulk
solution yield the central charges of the dual CFT and confirm the results that
appeared earlier on in the literature. We finally comment on some points
concerning the microstate counting for the Riemann-Cartan black hole.


title: Invariant measures for a stochastic Kuramoto-Sivashinky equation

abstract:
  For the 1-dimensional Kuramoto-Sivashinsky equation with random forcing term,
existence and uniqueness of solutions is proved. Then, the Markovian semigroup
is well defined; its properties are analyzed, in order to provide sufficient
conditions for existence and uniqueness of invariant measures for this
stochastic equation. Finally, regularity results are presented.


title:
Two-flavor lattice QCD in the epsilon-regime and chiral Random Matrix
  Theory

abstract:
  The low-lying eigenvalue spectrum of the QCD Dirac operator in the
epsilon-regime is expected to match with that of chiral Random Matrix Theory
(ChRMT). We study this correspondence for the case including sea quarks by
performing two-flavor QCD simulations on the lattice. Using the overlap fermion
formulation, which preserves exact chiral symmetry at finite lattice spacings,
we push the sea quark mass down to \sim 3 MeV on a 16^3\times 32 lattice at a
lattice spacing a \simeq 0.11 fm. We compare the low-lying eigenvalue
distributions and find a good agreement with the analytical predictions of
ChRMT. By matching the lowest-lying eigenvalue we extract the chiral
condensate, \Sigma(2 GeV)[MSbar] = [251(7)(11) MeV]^3, where errors represent
statistical and higher order effects in the epsilon expansion. We also
calculate the eigenvalue distributions on the lattices with heavier sea quarks
at two lattice spacings. Although the epsilon expansion is not applied for
those sea quarks, we find a reasonable agreement of the Dirac operator spectrum
with ChRMT. The value of Sigma, after extrapolating to the chiral limit, is
consistent with the estimate in the epsilon-regime.


title:
Measuring the Baryon Acoustic Oscillation scale using the SDSS and
  2dFGRS

abstract:
  We introduce a method to constrain general cosmological models using Baryon
Acoustic Oscillation (BAO) distance measurements from galaxy samples covering
different redshift ranges, and apply this method to analyse samples drawn from
the SDSS and 2dFGRS. BAO are detected in the clustering of the combined 2dFGRS
and SDSS main galaxy samples, and measure the distance--redshift relation at
z=0.2. BAO in the clustering of the SDSS luminous red galaxies measure the
distance--redshift relation at z=0.35. The observed scale of the BAO calculated
from these samples and from the combined sample are jointly analysed using
estimates of the correlated errors, to constrain the form of the distance
measure D_V(z)=[(1+z)^2D_A^2cz/H(z)]^(1/3). Here D_A is the angular diameter
distance, and H(z) is the Hubble parameter. This gives
r_s/D_V(0.2)=0.1980+/-0.0058 and r_s/D_V(0.35)=0.1094+/-0.0033 (1sigma errors),
with correlation coefficient of 0.39, where r_s is the comoving sound horizon
scale at recombination. Matching the BAO to have the same measured scale at all
redshifts then gives D_V(0.35)/D_V(0.2)=1.812+/-0.060. The recovered ratio is
roughly consistent with that predicted by the higher redshift SNLS supernovae
data for Lambda cosmologies, but does require slightly stronger cosmological
acceleration at low redshift. If we force the cosmological model to be flat
with constant w, then we find Om_m=0.249+/-0.018 and w=-1.004+/-0.089 after
combining with the SNLS data, and including the WMAP measurement of the
apparent acoustic horizon angle in the CMB.


title: Coordinate/Field Affinity: A Proposal For Confinement

abstract:
  It is argued that demanding for similar characters between the coordinates of
space-time and the fields would sound that non-Abelian gauge theories might be
formulated most naturally based on fields depending on matrix coordinates.


title:
The Color Magnitude Distribution of Field Galaxies to z~3: the evolution
  and modeling of the blue sequence

abstract:
  Using deep NIR VLT/ISAAC and optical HST/WFPC2 imaging in the fields of the
HDFS and MS1054-03, we study the rest-frame UV-to-optical colors and magnitudes
of galaxies to z~3. While there is no evidence for a red sequence at z~3, there
does appear to be a well-defined color-magnitude relation (CMR) for blue
galaxies at all redshifts, with more luminous galaxies having redder U-V
colors. The slope of the blue CMR is independent of redshift d(U-V)/dMV = -0.09
(0.01) and can be explained by a correlation of dust-reddening with luminosity.
The average color at fixed luminosity reddens strongly \Delta(U-V) = 0.75 from
z~3 to z=0, much of which can be attributed to aging of the stars. The color
scatter of the blue sequence is relatively small sigma(U-V) = 0.25 (0.03) and
constant to z~3, but notably asymmetrical with a sharp blue ridge and a wing
towards redder colors. We explore sets of star formation histories to study the
constraints placed by the shape of the scatter at z=2-3. One particular set of
models, episodic star formation, reproduces the detailed properties very well.
For a two-state model with high and low star formation, the duty cycle is
constrained to be > 40% and the contrast between the states must be a factor >
5 (or a scatter in log(SFR) of > 0.35 dex around the mean). However, episodic
models do not explain the observed tail of very red galaxies, primarily Distant
Red Galaxies (DRGs), which may have ceased star formation altogether or are
more heavily obscured. Finally, the relative number density of red, luminous MV
< -20.5 galaxies increases by a factor of ~ 6 from z = 2.7 to z = 0.5, as does
their contribution to the total rest-frame V-band luminosity density. We are
likely viewing the progressive formation of red, passively evolving galaxies.


title: Critical adsorption on non-spherical colloidal particles

abstract:
  We consider a non-spherical colloidal particle immersed in a fluid close to
its critical point. The temperature dependence of the corresponding order
parameter profile is calculated explicitly. We perform a systematic expansion
of the order parameter profile in powers of the local curvatures of the surface
of the colloidal particle. This curvature expansion reduces to the short
distance expansion of the order parameter profile in the case that the solvent
is at the critical composition.


title:
Revelation of the role of impurities and conduction electron density in
  the high resolution photoemission study of ferromagnetic hexaborides

abstract:
  We investigate the temperature evolution of the electronic structure of
ferromagnetic CaB$_6$ using ultra-high resolution photoemission spectroscopy;
electronic structure of paramagnetic LaB$_6$ is used as a reference. High
resolution spectra of CaB$_6$ reveal finite density of states at the Fermi
level, $\epsilon_F$ at all the temperatures and evidence of impurity induced
localized features in the vicinity of $\epsilon_F$, which are absent in the
spectra of LaB$_6$. Analysis of the high resolution spectra suggests that
disorder in B-sublattice inducing partial localization in the mobile electrons
and low electron density at $\epsilon_F$ is important to achieve ferromagnetism
in these systems.


title: Thermal equilibrium and statistical thermometers in special relativity

abstract:
  There is an intense debate in the recent literature about the correct
generalization of Maxwell's velocity distribution in special relativity. The
most frequently discussed candidate distributions include the Juettner function
as well as modifications thereof. Here, we report results from fully
relativistic one-dimensional (1D) molecular dynamics (MD) simulations that
resolve the ambiguity. The numerical evidence unequivocally favors the Juettner
distribution. Moreover, our simulations illustrate that the concept of 'thermal
equilibrium' extends naturally to special relativity only if a many-particle
system is spatially confined. They make evident that 'temperature' can be
statistically defined and measured in an observer frame independent way.


title: Softening of the stiffness of bottlebrush polymers by mutual interaction

abstract:
  We study bottlebrush macromolecules in a good solvent by small-angle neutron
scattering (SANS), static light scattering (SLS), and dynamic light scattering
(DLS). These polymers consist of a linear backbone to which long side chains
are chemically grafted. The backbone contains about 1600 monomer units (weight
average) and every second monomer unit carries side-chains with ca. 60 monomer
units. The SLS- and SANS data extrapolated to infinite dilution lead to the
form factor of the polymer that can be described in terms of a worm-like chain
with a contour length of 380 nm and a persistence length of 17.5 nm. An
analysis of the DLS data confirm these model parameters. The scattering
intensities taken at finite concentration can be modeled using the polymer
reference interaction site model. It reveals a softening of the bottlebrush
polymers caused by their mutual interaction. We demonstrate that the
persistence decreases from 17.5 nm down to 5 nm upon increasing the
concentration from dilute solution to the highest concentration 40.59 g/l under
consideration. The observed softening of the chains is comparable to the
theoretically predicted decrease of the electrostatic persistence length of
linear polyelectrolyte chains at finite concentrations.


title: SUSY Breaking at the Tip of Throat and Mirage Mediation

abstract:
  We discuss some features of supersymmetry breaking induced by a
brane-localized source which is stabilized at the IR end of warped throat, and
also the resulting mirage mediation pattern of soft terms of the visible fields
which are localized in the bulk space corresponding to the UV end of throat.
Such supersymmetry breaking scheme can be naturally realized in KKLT-type
string compactification, and predicts highly distinctive pattern of low energy
superparticle masses which might be tested at the LHC.


title: Structure factor and thermodynamics of rigid dendrimers in solution

abstract:
  The ''polymer reference interaction site model'' (PRISM) integral equation
theory is used to determine the structure factor of rigid dendrimers in
solution. The theory is quite successful in reproducing experimental structure
factors for various dendrimer concentrations. In addition, the structure factor
at vanishing scattering vector is calculated via the compressibility equation
using scaled particle theory and fundamental measure theory. The results as
predicted by both theories are systematically smaller than the experimental and
PRISM data for platelike dendrimers.


title: High Resolution Spectroscopy of 12B_Lambda by Electroproduction

abstract:
  An experiment measuring electroproduction of hypernuclei has been performed
in Hall A at Jefferson Lab on a $^{12}$C target. In order to increase counting
rates and provide unambiguous kaon identification two superconducting septum
magnets and a Ring Imaging CHerenkov detector (RICH) were added to the Hall A
standard equipment. An unprecedented energy resolution of less than 700 keV
FWHM has been achieved. Thus, the observed \lam{12}{B} spectrum shows for the
first time identifiable strength in the core-excited region between the
ground-state {\it s}-wave $\Lambda$ peak and the 11 MeV {\it p}-wave $\Lambda$
peak.


title: Simulation of Quantum Algorithms with a Symbolic Programming Language

abstract:
  This study examines the simulation of quantum algorithms on a classical
computer. The program code implemented on a classical computer will be a
straight connection between the mathematical formulation of quantum mechanics
and computational methods. The computational language will include formulations
such as quantum state, superposition and quantum operator.


title: Supergravity inspired Vector Curvaton

abstract:
  It is investigated whether a massive Abelian vector field, whose gauge
kinetic function is growing during inflation, can be responsible for the
generation of the curvature perturbation in the Universe. Particle production
is studied and it is shown that the vector field can obtain a scale invariant
superhorizon spectrum of perturbations with a reasonable choice of kinetic
function. After inflation the vector field begins coherent oscillations, during
which it corresponds to pressureless isotropic matter. When the vector field
dominates the Universe its perturbations give rise to the observed curvature
perturbation following the curvaton scenario. It is found that this is possible
if, after the end of inflation, the mass of the vector field increases at a
phase transition at temperature of order 1 TeV or lower. Inhomogeneous
reheating, whereby the vector field modulates the decay rate of the inflaton,
is also studied.


title: The Infrared Ca II triplet as metallicity indicator

abstract:
  From observations of almost 500 RGB stars in 29 Galactic open and globular
clusters, we have investigated the behaviour of the infrared Ca II triplet
(8498, 8542 and 8662 \AA) in the age range 13$\leq$Age/Gyr$\leq$0.25 and the
metallicity range $-2.2\leq$ [Fe/H] $\leq$+0.47. These are the widest ranges of
ages and metallicities in which the behaviour of the Ca II triplet lines has
been investigated in a homogeneous way. We report the first empirical study of
the variation of the CaII triplet lines strength, for given metallicities, with
respect to luminosity. We find that the sequence defined by each cluster in the
Luminosity-$\Sigma$Ca plane is not exactly linear. However, when only stars in
a small magnitude interval are observed, the sequences can be considered as
linear. We have studied the the Ca II triplet lines on three metallicities
scales. While a linear correlation between the reduced equivalent width ($W'_V$
or $W'_I$) versus metallicity is found in the \citet{cg97} and \citet{ki03}
scales, a second order term needs to be added when the \citet{zw84} scale is
adopted. We investigate the role of age from the wide range of ages covered by
our sample. We find that age has a weak influence on the final relationship.
Finally, the relationship derived here is used to estimate the metallicities of
three poorly studied open clusters: Berkeley 39, Trumpler 5 and Collinder 110.
For the latter, the metallicity derived here is the first spectroscopic
estimate available.


title:
Preliminary Sunyaev Zel'dovich Observations of Galaxy Clusters with
  OCRA-p

abstract:
  We present 30 GHz Sunyaev Zel'dovich (SZ) observations of a sample of four
galaxy clusters with a prototype of the One Centimetre Receiver Array (OCRA-p)
which is mounted on the Torun 32-m telescope. The clusters (Cl0016+16,
MS0451.6-0305, MS1054.4-0321 and Abell 2218) are popular SZ targets and serve
as commissioning observations. All four are detected with clear significance
(4-6 sigma) and values for the central temperature decrements are in good
agreement with measurements reported in the literature. We believe that
systematic effects are successfully suppressed by our observing strategy. The
relatively short integration times required to obtain these results demonstrate
the power of OCRA-p and its successors for future SZ studies.


title: Ascending number of knots and links

abstract:
  We introduce a new numerical invariant of knots and links from the descending
diagrams. It is considered to live between the unknotting number and the bridge
number.


title:
Detection of Emission from the CN Radical in the Cloverleaf Quasar at
  z=2.56

abstract:
  We report the detection of CN(N=3-2) emission towards the Cloverleaf quasar
(z=2.56) based on observations with the IRAM Plateau de Bure Interferometer.
This is the first clear detection of emission from this radical at high
redshift. CN emission is a tracer of dense molecular hydrogen gas (n(H2) > 10^4
cm^{-3}) within star-forming molecular clouds, in particular in regions where
the clouds are affected by UV radiation. The HCN/CN intensity ratio can be used
as a diagnostic for the relative importance of photodissociation regions (PDRs)
in a source, and as a sensitive probe of optical depth, the radiation field,
and photochemical processes. We derive a lensing-corrected CN(N=3-2) line
luminosity of L'(CN(3-2) = (4.5 +/- 0.5) x 10^9 K km/s pc^2. The ratio between
CN luminosity and far-infrared luminosity falls within the scatter of the same
relationship found for low-z (ultra-) luminous infrared galaxies. Combining our
new results with CO(J=3-2) and HCN(J=1-0) measurements from the literature and
assuming thermal excitation for all transitions, we find a CO/CN luminosity
ratio of 9.3 +/- 1.9 and a HCN/CN luminosity ratio of 0.95 +/- 0.15. However,
we find that the CN(N=3-2) line is likely only subthermally excited, implying
that those ratios may only provide upper limits for the intrinsic 1-0 line
luminosity ratios. We conclude that, in combination with other molecular gas
tracers like CO, HCN, and HCO+, CN is an important probe of the physical
conditions and chemical composition of dense molecular environments at high
redshift.