title:
Lifetime of the superconductive state in short and long Josephson
  junctions

abstract:
  We study the transient statistical properties of short and long Josephson
junctions under the influence of thermal and correlated fluctuations. In
particular, we investigate the lifetime of the superconductive metastable state
finding the presence of noise induced phenomena. For short Josephson junctions
we investigate the lifetime as a function both of the frequency of the current
driving signal and the noise intensity and we find how these noise-induced
effects are modified by the presence of a correlated noise source. For long
Josephson junctions we integrate numerically the sine-Gordon equation
calculating the lifetime as a function of the length of the junction both for
inhomogeneous and homogeneous bias current distributions. We obtain a
nonmonotonic behavior of the lifetime as a function of the frequency of the
current driving signal and the correlation time of the noise. Moreover we find
two maxima in the nonmonotonic behaviour of the mean escape time as a function
of the correlated noise intensity.


title:
Direct observation of the basic mechanisms of Pd island nucleation on
  Au(111)

abstract:
  The formation mechanisms of evaporated Pd islands on the reconstructed
Au(111) $22 /times /sqrt{3}$ herringbone surface have been here studied by
Scanning Tunneling Microscopy (STM) at room temperature. Atomically resolved
STM images at the very early stages of growth provide a direct observation of
the mechanisms involved in preferential Pd islands nucleation at the elbows of
the herringbone structure. At low Pd coverage the Au(111) herringbone structure
remains substantially unperturbed and isolated Pd atoms settled in hollow sites
between Au atoms are found nearby the elbows and the distortions of the
reconstructed surface. In the same regions, at extremely low coverage (0.003
ML), substituted Pd atoms in lattice sites of the Au(111) surface are also
observed, revealing the occurrence of a place exchange mechanism. Substitution
seems to play a fundamental role in the nucleation process, forming aggregation
centers for incoming atoms and thus leading to the ordered growth of Pd islands
on Au(111). Atomically resolved STM images of Pd islands reveal a close-packed
arrangement with lattice parameter close to the interatomic distance between
gold atoms in the fcc regions of the Au(111) surface. Distortion of the
herringbone structure for Pd coverages higher than 0.25 ML indicates strong
interaction between the growing islands and the topmost Au(111) layer.


title: Light $\Xi$ hypernuclei in four-body cluster models

abstract:
  Detailed structure calculations in $^{\: 12}_{\Xi^-}$Be, $^{\: 5}_{\Xi^-}$H,
$^{\: 9}_{\Xi^-}$Li, $^{\: 7}_{\Xi^-}$H and $^{\:10}_{\Xi^-}$Li are performed
within the framework of the microscopic two-, three- and four-body cluster
models using the Gaussian Expansion Method.


title:
Spin mixing in colliding spinor condensates: formation of an effective
  barrier

abstract:
  The dynamics of F=1 spinor condensates initially prepared in a double-well
potential is studied in the mean field approach. It is shown that a small seed
of $m=0$ atoms on a system with initially well separated m=1 and m=-1
condensates has a dramatic effect on their mixing dynamics, acting as an
effective barrier for a remarkably long time. We show that this effect is due
to the spinor character of the system, and provides an observable example of
the interplay between the internal spin dynamics and the macroscopic evolution
of the magnetization in a spinor Bose-Einstein condensate.


title: Ion-beam modification of the magnetic properties of GaMnAs epilayers

abstract:
  We study the controlled introduction of defects in GaMnAs by irradiating the
samples with energetic ion beams, which modify the magnetic properties of the
DMS. Our study focuses on the low-carrier-density regime, starting with
as-grown GaMnAs films and decreasing even further the number of carriers,
through a sequence of irradiation doses. We did a systematic study of
magnetization as a function of temperature and of the irradiation ion dose. We
also performed in-situ room temperature resistivity measurements as a function
of the ion dose. We observe that both magnetic and transport properties of the
samples can be experimentally manipulated by controlling the ion-beam
parameters. For highly irradiated samples, the magnetic measurements indicate
the formation of magnetic clusters together with a transition to an insulating
state. The experimental data are compared with mean-field calculations for
magnetization. The independent control of disorder and carrier density in the
calculations allows further insight on the individual role of this two factors
in the ion-beam-induced modification of GaMnAs.


title: The structure of minimizers of the frame potential on fusion frames

abstract:
  In this paper we study the fusion frame potential, that is a generalization
of the Benedetto-Fickus (vectorial) frame potential to the finite-dimensional
fusion frame setting. The structure of local and global minimizers of this
potential is studied, when we restrict the frame potential to suitable sets of
fusion frames. These minimizers are related to tight fusion frames as in the
classical vector frame case. Still, tight fusion frames are not as frequent as
tight frames; indeed we show that there are choices of parameters involved in
fusion frames for which no tight fusion frame can exist. Thus, we exhibit
necessary and sufficient conditions for the existence of tight fusion frames
with prescribed parameters, involving the so-called Horn-Klyachko's
compatibility inequalities. The second part of the work is devoted to the study
of the minimization of the fusion frame potential on a fixed sequence of
subspaces, varying the sequence of weights. We related this problem to the
index of the Hadamard product by positive matrices and use it to give different
characterizations of these minima.


title: The irreducible components of Hilb^{4n}(P^3)

abstract: It is shown that Hilb^{4n}(P^3)has exactly two irreducible components.


title: An Almost Optimal Rank Bound for Depth-3 Identities

abstract:
  We show that the rank of a depth-3 circuit (over any field) that is simple,
minimal and zero is at most k^3\log d. The previous best rank bound known was
2^{O(k^2)}(\log d)^{k-2} by Dvir and Shpilka (STOC 2005). This almost resolves
the rank question first posed by Dvir and Shpilka (as we also provide a simple
and minimal identity of rank \Omega(k\log d)).
  Our rank bound significantly improves (dependence on k exponentially reduced)
the best known deterministic black-box identity tests for depth-3 circuits by
Karnin and Shpilka (CCC 2008). Our techniques also shed light on the
factorization pattern of nonzero depth-3 circuits, most strikingly: the rank of
linear factors of a simple, minimal and nonzero depth-3 circuit (over any
field) is at most k^3\log d.
  The novel feature of this work is a new notion of maps between sets of linear
forms, called "ideal matchings", used to study depth-3 circuits. We prove
interesting structural results about depth-3 identities using these techniques.
We believe that these can lead to the goal of a deterministic polynomial time
identity test for these circuits.


title:
Double-quantum-coherence attosecond x-ray spectroscopy of spatially
  separated, spectrally overlapping core-electron transitions

abstract:
  X-ray four-wave mixing signals generated in the $k_1 + k_2 - k_3$
phase-matching direction are simulated for N1s transitions in para-nitroanline
and two-ring hydrocarbons disubstituted with an amine and a nitroso groups. The
two-dimensional x-ray correlation spectra (2DXCS) provide background-free
probes of couplings between core-electron transitions even for multiple core
shells of the same type. Features attributed to couplings between
spatially-separated core transitions connected by delocalized valence
excitations provide information about molecular geometry and electronic
structure unavailable from linear near-edge x-ray absorption (XANES).


title:
Stochasticity and traffic jams in the transcription of ribosomal RNA:
  Intriguing role of termination and antitermination

abstract:
  In fast growing bacteria, ribosomal RNA (rRNA) is required to be transcribed
at very high rates to sustain the high cellular demand on ribosome synthesis.
This results in dense traffic of RNA polymerases (RNAP). We developed a
stochastic model, integrating results of single-molecule and quantitative in
vivo studies of E. coli, to evaluate the quantitative effect of pausing,
termination, and antitermination on rRNA transcription. Our calculations reveal
that in dense RNAP traffic, spontaneous pausing of RNAP can lead to severe
"traffic jams", as manifested in the broad distribution of inter-RNAP distances
and can be a major factor limiting transcription and hence growth. Our results
suggest the suppression of these pauses by the ribosomal antitermination
complex to be essential at fast growth. Moreover, unsuppressed pausing by even
a few non-antiterminated RNAPs can already reduce transcription drastically
under dense traffic. However, the termination factor Rho can remove the
non-antiterminated RNAPs and restore fast transcription. The results thus
suggest an intriguing role by Rho to enhance rather than attenuate rRNA
transcription.


title: Classification of life by the mechanism of genome size evolution

abstract:
  The classification of life should be based upon the fundamental mechanism in
the evolution of life. We found that the global relationships among species
should be circular phylogeny, which is quite different from the common sense
based upon phylogenetic trees. The genealogical circles can be observed clearly
according to the analysis of protein length distributions of contemporary
species. Thus, we suggest that domains can be defined by distinguished
phylogenetic circles, which are global and stable characteristics of living
systems. The mechanism in genome size evolution has been clarified; hence main
component questions on C-value enigma can be explained. According to the
correlations and quasi-periodicity of protein length distributions, we can also
classify life into three domains.


title:
Trading GRH for algebra: algorithms for factoring polynomials and
  related structures

abstract:
  In this paper we develop techniques that eliminate the need of the
Generalized Riemann Hypothesis (GRH) from various (almost all) known results
about deterministic polynomial factoring over finite fields. Our main result
shows that given a polynomial f(x) of degree n over a finite field k, we can
find in deterministic poly(n^{\log n},\log |k|) time "either" a nontrivial
factor of f(x) "or" a nontrivial automorphism of k[x]/(f(x)) of order n. This
main tool leads to various new GRH-free results, most striking of which are:
  (1) Given a noncommutative algebra over a finite field, we can find a zero
divisor in deterministic subexponential time.
  (2) Given a positive integer r such that either 8|r or r has at least two
distinct odd prime factors. There is a deterministic polynomial time algorithm
to find a nontrivial factor of the r-th cyclotomic polynomial over a finite
field.
  In this paper, following the seminal work of Lenstra (1991) on constructing
isomorphisms between finite fields, we further generalize classical Galois
theory constructs like cyclotomic extensions, Kummer extensions, Teichmuller
subgroups, to the case of commutative semisimple algebras with automorphisms.
These generalized constructs help eliminate the dependence on GRH.


title:
Combining Semi-analytic Models with Simulations of Galaxy Clusters: the
  Need for Heating from Active Galactic Nuclei

abstract:
  We present hydrodynamical N-body simulations of clusters of galaxies with
feedback taken from semi-analytic models of galaxy formation. The advantage of
this technique is that the source of feedback in our simulations is a
population of galaxies that closely resembles that found in the real universe.
We demonstrate that, to achieve the high entropy levels found in clusters,
active galactic nuclei must inject a large fraction of their energy into the
intergalactic/intracluster media throughout the growth period of the central
black hole. These simulations reinforce the argument of Bower et al., who
arrived at the same conclusion on the basis of purely semi-analytic reasoning.


title:
Influence of oxygen reduction on the structural and electronic
  properties of electron-doped Sr1-xLaxCuO2 thin films

abstract:
  Single phase, c-axis oriented, e-doped, Sr1-xLaxCuO2 thin films were
epitaxially grown on KTaO3 and DyScO3 substrates by reactive rf sputtering.
As-grown films being insulating due to oxygen excess, oxygen reduction is
necessary to observe superconductivity. Two different procedures were employed
to reach superconductivity. On one hand an in-situ reduction process was
conducted on a series of films deposited on both types of substrates. On the
other hand, an ex-situ reduction procedure was performed sequentially on a
single film deposited on DyScO3. The study of the influence of oxygen reduction
on the structural and electronic properties of the thin films is presented and
discussed.


title:
Dynamic heterogeneities in critical coarsening: Exact results for
  correlation and response fluctuations in finite-sized spherical models

abstract:
  We study dynamic heterogeneities in the out-of-equilibrium coarsening
dynamics of the spherical ferromagnet after a quench from infinite temperature
to its critical point. A standard way of probing such heterogeneities is by
monitoring the fluctuations of correlation and susceptibility, coarse-grained
over mesoscopic regions. We discuss how to define fluctuating coarse-grained
correlations (C) and susceptibilities (Chi) in models where no quenched
disorder is present. Our focus for the spherical model is on coarse-graining
over the whole volume of $N$ spins, which requires accounting for N^{-1/2}
non-Gaussian fluctuations of the spin. The latter are treated as a perturbation
about the leading order Gaussian statistics. We obtain exact results for these
quantities, which enable us to characterise the joint distribution of C and Chi
fluctuations. We find that this distribution is qualitatively different, even
for equilibrium above criticality, from the spin-glass scenario where C and Chi
fluctuations are linked in a manner akin to the fluctuation-dissipation
relation between the average C and Chi. Our results show that coarsening at
criticality is clearly heterogeneous for d>4 and suggest that, as in other
glassy systems, there is a well-defined timescale on which fluctuations across
thermal histories are largest. Surprisingly, however, neither this timescale
nor the amplitude of the heterogeneities increase with the age of the system,
as would be expected from the growing correlation length. For d<4, the strength
of the fluctuations varies on a timescale proportional to the age of the
system; the corresponding amplitude also grows with age, but does not scale
with the correlation volume as might have been expected naively.


title: Tempered fundamental group and metric graph of a Mumford curve

abstract:
  This paper is an attempt to give some general results on the tempered
fundamental group of a $p$-adic smooth algebraic varieties (which is a sort of
analog of the topologic fundamental group of complex algebraic varieties in the
p-adic world). The main result asserts that one can recover the metric
structure of the graph of the stable model of a Mumford curve from the tempered
fundamental group of this Mumford curve. We will also prove birational
invariance, invariance by algebraically closed extensions and a Kuenneth
formula for the tempered fundamental group. We will describe the tempered
fundamental group of an abelian variety and link the tempered fundamental group
of a curve to the tempered fundamental group of its Jacobian variety.


title:
Anisotropies in momentum space at finite Shear Viscosity in
  ultrarelativistic heavy-ion collisions

abstract:
  Within a parton cascade we investigate the dependence of anisotropies in
momentum space, namely the elliptic flow $v_2=<cos(2\phi)>$ and the
$v_4=<cos(4\phi)>$, on both the finite shear viscosity $\eta$ and the
freeze-out (f.o.) dynamics at the RHIC energy of 200 AGeV. In particular it is
discussed the impact of the f.o. dynamics looking at two different procedures:
switching-off the collisions when the energy density goes below a fixed value
or reducing the cross section according to the increase in $\eta/s$ from a QGP
phase to a hadronic one. We address the relation between the scaling of
$v_2(p_T)$ with the eccentricity $\epsilon_x$ and with the integrated elliptic
flow. We show that the breaking of the $v_2(p_T)/\epsilon_x$ scaling is not
coming mainly from the finite $\eta/s$ but from the f.o. dynamics and that the
$v_2(p_T)$ is weakly dependent on the f.o. scheme. On the other hand the
$v_4(p_T)$ is found to be much more dependent on both the $\eta/s$ and the f.o.
dynamics and hence is indicated to put better constraints on the properties of
the QGP. A first semi-quantitative analysis show that both $v_2$ and $v_4$
(with the smooth f.o.) consistently indicate a plasma with $4\pi \eta/s \sim
1-2$.


title: Quantum algorithm for solving linear systems of equations

abstract:
  Solving linear systems of equations is a common problem that arises both on
its own and as a subroutine in more complex problems: given a matrix A and a
vector b, find a vector x such that Ax=b. We consider the case where one
doesn't need to know the solution x itself, but rather an approximation of the
expectation value of some operator associated with x, e.g., x'Mx for some
matrix M. In this case, when A is sparse, N by N and has condition number
kappa, classical algorithms can find x and estimate x'Mx in O(N sqrt(kappa))
time. Here, we exhibit a quantum algorithm for this task that runs in poly(log
N, kappa) time, an exponential improvement over the best classical algorithm.


title:
Exact computation of image disruption under reflection on a smooth
  surface and Ronchigrams

abstract:
  We use geometrical optics and the caustic-touching theorem to study, in an
exact way, the change in the topology of the image of an object obtained by
reflections on an arbitrary smooth surface. Since the procedure that we use to
compute the image is exactly the same as that used to simulate the ideal
patterns, referred to as Ronchigrams, in the Ronchi test used to test mirrors,
we remark that the closed loop fringes commonly observed in the Ronchigrams
when the grating, referred to as a Ronchi ruling, is located at the caustic
place are due to a disruption of fringes, or, more correctly, as disruption of
shadows corresponding to the ruling bands. To illustrate our results, we assume
that the reflecting surface is a spherical mirror and we consider two kinds of
objects: circles and line segments.


title: VLBI Observations of SN 2008D

abstract:
  We report on two epochs of very-long-baseline interferometry (VLBI)
observations of the Type Ib/c supernova SN 2008D, which was associated with the
X-ray outburst XRF 080109. At our first epoch, at t = 30 days after the
explosion, we observed at 22 and 8.4 GHz, and at our second, at t = 133 days,
at 8.4 and 5.0 GHz. The VLBI observations allow us to accurately measure the
source's size and position at each epoch, and thus constrain its expansion
velocity and proper motion. We find the source at best marginally resolved at
both epochs, allowing us to place a 3sigma upper limit of ~0.75c on the
expansion velocity of a circular source. For an elongated source, our
measurements are compatible with mildly relativistic expansion. However, our
3sigma upper limit on the proper motion is 4 micro-arcsec/day, corresponding to
an apparent velocity of <0.6c, and is consistent with a stationary flux
centroid. This limit rules out a relativistic jet such as an gamma-ray burst
jet away from the line of sight, which would be expected to show apparent
proper motion of >c. Taken together, our measurements argue against the
presence of any long-lived relativistic outflow in SN 2008D. On the other hand,
our measurements are consistent with the nonrelativistic expansion velocities
of <30,000 km/s and small proper motions (<500 km/s) seen in typical
supernovae.


title: Deformed Statistics Formulation of the Information Bottleneck Method

abstract:
  The theoretical basis for a candidate variational principle for the
information bottleneck (IB) method is formulated within the ambit of the
generalized nonadditive statistics of Tsallis. Given a nonadditivity parameter
$ q $, the role of the \textit{additive duality} of nonadditive statistics ($
q^*=2-q $) in relating Tsallis entropies for ranges of the nonadditivity
parameter $ q < 1 $ and $ q > 1 $ is described. Defining $ X $, $ \tilde X $,
and $ Y $ to be the source alphabet, the compressed reproduction alphabet, and,
the \textit{relevance variable} respectively, it is demonstrated that
minimization of a generalized IB (gIB) Lagrangian defined in terms of the
nonadditivity parameter $ q^* $ self-consistently yields the
\textit{nonadditive effective distortion measure} to be the \textit{$ q
$-deformed} generalized Kullback-Leibler divergence: $
D_{K-L}^{q}[p(Y|X)||p(Y|\tilde X)] $. This result is achieved without enforcing
any \textit{a-priori} assumptions. Next, it is proven that the $q^*-deformed $
nonadditive free energy of the system is non-negative and convex. Finally, the
update equations for the gIB method are derived. These results generalize
critical features of the IB method to the case of Tsallis statistics.


title: Homotopy fiber products of homotopy theories

abstract:
  Given an appropriate diagram of left Quillen functors between model
categories, one can define a notion of homotopy fiber product, but one might
ask if it is really the correct one. Here, we show that this homotopy pullback
is well-behaved with respect to translating it into the setting of more general
homotopy theories, given by complete Segal spaces, where we have well-defined
homotopy pullbacks.


title: Self-stabilizing Numerical Iterative Computation

abstract:
  Many challenging tasks in sensor networks, including sensor calibration,
ranking of nodes, monitoring, event region detection, collaborative filtering,
collaborative signal processing, {\em etc.}, can be formulated as a problem of
solving a linear system of equations. Several recent works propose different
distributed algorithms for solving these problems, usually by using linear
iterative numerical methods.
  In this work, we extend the settings of the above approaches, by adding
another dimension to the problem. Specifically, we are interested in {\em
self-stabilizing} algorithms, that continuously run and converge to a solution
from any initial state. This aspect of the problem is highly important due to
the dynamic nature of the network and the frequent changes in the measured
environment.
  In this paper, we link together algorithms from two different domains. On the
one hand, we use the rich linear algebra literature of linear iterative methods
for solving systems of linear equations, which are naturally distributed with
rapid convergence properties. On the other hand, we are interested in
self-stabilizing algorithms, where the input to the computation is constantly
changing, and we would like the algorithms to converge from any initial state.
We propose a simple novel method called \syncAlg as a self-stabilizing variant
of the linear iterative methods. We prove that under mild conditions the
self-stabilizing algorithm converges to a desired result. We further extend
these results to handle the asynchronous case.
  As a case study, we discuss the sensor calibration problem and provide
simulation results to support the applicability of our approach.


title: Theory versus experiment for vacuum Rabi oscillations in lossy cavities

abstract:
  The 1996 Brune {\it et al.} experiment on vacuum Rabi oscillation is analyzed
by means of alternative models of atom-reservoir interaction. Agreement with
experimental Rabi oscillation data can be obtained if one defines jump
operators in the dressed-state basis, and takes into account thermal
fluctuations between dressed states belonging to the same manifold. Such
low-frequency transitions could be ignored in a closed cavity, but the cavity
employed in the experiment was open, which justifies our assumption. The cavity
quality factor corresponding to the data is $Q=3.31\cdot 10^{10}$, whereas $Q$
reported in the experiment was $Q=7\cdot 10^7$. The rate of decoherence arising
from opening of the cavity can be of the same order as an analogous correction
coming from finite time resolution $\Delta t$ (formally equivalent to
collisional decoherence). Peres-Horodecki separability criterion shows that the
rate at which the atom-field state approaches a separable state is controlled
by fluctuations between dressed states from the same manifold, and not by the
rate of transitions towards the ground state. In consequence, improving the $Q$
factor we do not improve the coherence properties of the cavity.


title:
Transport Anisotropy as a Probe of the Interstitial Vortex State in
  Superconductors with Artificial Pinning Arrays

abstract:
  We show using simulations that when interstitial vortices are present in
superconductors with periodic pinning arrays, the transport in two
perpendicular directions can be anisotropic. The degree of the anisotropy
varies as a function of field due to the fact that the interstitial vortex
lattice has distinct orderings at different matching fields. The anisotropy is
most pronounced at the matching fields but persists at incommensurate fields,
and it is most prominent for triangular, honeycomb, and kagome pinning arrays.
Square pinning arrays can also show anisotropic transport at certain fields in
spite of the fact that the perpendicular directions of the square pinning array
are identical. We show that the anisotropy results from distinct vortex
dynamical states and that although the critical depinning force may be lower in
one direction, the vortex velocity above depinning may also be lower in the
same direction for ranges of external drives where both directions are
depinned. For honeycomb and kagome pinning arrays, the anisotropy can show
multiple reversals as a function of field. We argue that when the pinning sites
can be multiply occupied such that no interstitial vortices are present, the
anisotropy is strongly reduced or absent.


title:
The chemical abundances in the Galactic Centre from the atmospheres of
  Red Supergiants

abstract:
  The Galactic Centre (GC) has experienced a high degree of recent star-forming
activity, as evidenced by the large number of massive stars currently residing
there. The relative abundances of chemical elements in the GC may provide
insights into the origins of this activity. Here, we present high-resolution
$H$-band spectra of two Red Supergiants in the GC (IRS~7 and VR~5-7), and in
combination with spectral synthesis we derive abundances for Fe and C, as well
as other $\alpha$-elements Ca, Si, Mg Ti and O. We find that the C-depletion in
VR~5-7 is consistent with the predictions of evolutionary models of RSGs, while
the heavy depletion of C and O in IRS~7's atmosphere is indicative of deep
mixing, possibly due to fast initial rotation and/or enhanced mass-loss. Our
results indicate that the {\it current} surface Fe/H content of each star is
slightly above Solar. However, comparisons to evolutionary models indicate that
the {\it initial} Fe/H ratio was likely closer to Solar, and has been driven
higher by H-depletion at the stars' surface. Overall, we find $\alpha$/Fe
ratios for both stars which are consistent with the thin Galactic disk. These
results are consistent with other chemical studies of the GC, given the
precision to which abundances can currently be determined. We argue that the GC
abundances are consistent with a scenario in which the recent star-forming
activity in the GC was fuelled by either material travelling down the Bar from
the inner disk, or from the winds of stars in the inner Bulge -- with no need
to invoke top-heavy stellar Initial Mass Functions to explain anomalous
abundance ratios.


title: Geometric realizations of generalized algebraic curvature operators

abstract:
  We study the 8 natural GL equivariant geometric realization questions for the
space of generalized algebraic curvature tensors. All but one of them is
solvable; a non-zero projectively flat Ricci antisymmetric generalized
algebraic curvature is not geometrically realizable by a projectively flat
Ricci antisymmetric torsion free connection.


title:
On the symmetry of the vacuum in theories with spontaneous symmetry
  breaking

abstract:
  We review the usual account of the phenomena of spontaneous symmetry breaking
(SSB), pointing out the common misunderstandings surrounding the issue, in
particular within the context of quantum field theory. In fact, the common
explanations one finds in this context, indicate that under certain conditions
corresponding to the situation called SSB, the vacuum of the theory does not
share the symmetries of the Lagrangian. We explain in detail why this statement
is incorrect in general, and in what limited set of circumstances such
situation could arise. We concentrate on the case of global symmetries, for
which we found no satisfactory exposition in the existing literature, and
briefly comment on the case of gauge symmetries where, although insufficiently
publicized, accurate and complete descriptions exist. We briefly discuss the
implications for the phenomenological manifestations usually attributed to the
phenomena of spontaneous symmetry breaking, analyzing which might be affected
by our analysis and which are not. In particular we describe the mass
generation mechanism in a fully symmetric scheme (i.e., with a totally
symmetric vacuum), and briefly discuss the implications of this analysis to the
problem of formation of topological defects in the early universe.


title: On sequence spaces for Fr\'echet frames

abstract:
  We analyze the construction of a sequence space $\widetilde{\Theta}$, resp. a
sequence of sequence spaces, in order to have $\{g_i\}$ as a
$\widetilde{\Theta}$-frame or Banach frame for a Banach space $X$, resp.
pre-$F$-frame or $F$-frame for a Fr\'echet space $X_F=\cap_{s\in {\mathbb N}_0}
X_s$, where $\{X_s\}_{s\in {\mathbb N}_0}$ is a sequence of Banach spaces.


title: Random tree growth by vertex splitting

abstract:
  We study a model of growing planar tree graphs where in each time step we
separate the tree into two components by splitting a vertex and then connect
the two pieces by inserting a new link between the daughter vertices. This
model generalises the preferential attachment model and Ford's $\alpha$-model
for phylogenetic trees. We develop a mean field theory for the vertex degree
distribution, prove that the mean field theory is exact in some special cases
and check that it agrees with numerical simulations in general. We calculate
various correlation functions and show that the intrinsic Hausdorff dimension
can vary from one to infinity, depending on the parameters of the model.

categories: cond-mat.stat-mech math-ph math.MP math.PR


title:
The switching dynamics of the bacterial flagellar motor - Supporting
  Information

abstract:
  In this Supporting information we provide background information on our model
of the bacterial flagellar motor. We also derive the analytical solution of our
coarse-grained model of the switching dynamics and explain the hybrid
stochastic algorithm used for the simulations.


title: Conditionally Gaussian Hypermodels for Cerebral Source Localization

abstract:
  Bayesian modeling and analysis of the MEG and EEG modalities provide a
flexible framework for introducing prior information complementary to the
measured data. This prior information is often qualitative in nature, making
the translation of the available information into a computational model a
challenging task. We propose a generalized gamma family of hyperpriors which
allows the impressed currents to be focal and we advocate a fast and efficient
iterative algorithm, the Iterative Alternating Sequential (IAS) algorithm for
computing maximum a posteriori (MAP) estimates. Furthermore, we show that for
particular choices of the scalar parameters specifying the hyperprior, the
algorithm effectively approximates popular regularization strategies such as
the Minimum Current Estimate and the Minimum Support Estimate. The connection
between priorconditioning and adaptive regularization methods is also pointed
out. The posterior densities are explored by means of a Markov Chain Monte
Carlo (MCMC) strategy suitable for this family of hypermodels. The computed
experiments suggest that the known preference of regularization methods for
superficial sources over deep sources is a property of the MAP estimators only,
and that estimation of the posterior mean in the hierarchical model is better
adapted for localizing deep sources.


title: Any flat bundle on a punctured disc has an oper structure

abstract:
  We prove that any flat G-bundle, where G is a complex connected reductive
algebraic group, on the punctured disc admits the structure of an oper. This
result is important in the local geometric Langlands correspondence proposed in
arXiv:math/0508382. Our proof uses certain deformations of the affine Springer
fibers which could be of independent interest. As a byproduct, we construct
representations of affine Weyl groups on the homology of these deformations
generalizing representations constructed by Lusztig.


title: Noncommutative Geometry and Quantum Group Symmetries

abstract:
  Quantum groups and quantum homogeneous spaces - developed by several authors
since the 80's - provide a large class of examples of algebras which for many
reasons we interpret as `coordinate algebras' over noncommutative spaces. This
dissertation is an attempt to understand them from the point of view of Connes'
noncommutative geometry.


title: Colloidal attraction induced by a temperature gradient

abstract:
  Colloidal crystals are of extreme importance for applied research, such as
photonic crystals technology, and for fundamental studies in statistical
mechanics. Long range attractive interactions, such as capillary forces, can
drive the spontaneous assembly of such mesoscopic ordered structures. However
long range attractive forces are very rare in the colloidal realm. Here we
report a novel strong and long ranged attraction induced by a thermal gradient
in the presence of a wall. Switching on and off the thermal gradient we can
rapidly and reversibly form stable hexagonal 2D crystals. We show that the
observed attraction is hydrodynamic in nature and arises from thermal induced
slip flow on particle surfaces. We used optical tweezers to directly measure
the force law and compare it to an analytic prediction based on Stokes flow
driven by Marangoni forces.


title:
Conserved Noether Currents, Utiyama's Theory of Invariant Variation, and
  Velocity Dependence in Local Gauge Invariance

abstract:
  The paper discusses the mathematical consequences of the application of
derived variables in gauge fields. Physics is aware of several phenomena, which
depend first of all on velocities (like e.g., the force caused by charges
moving in a magnetic field, or the Lorentz transformation). Applying the
property of the second Noether theorem, that allowed generalised variables,
this paper extends the article by Al-Kuwari and Taha (1991) with a new
conclusion. They concluded that there are no extra conserved currents
associated with local gauge invariance. We show, that in a more general case,
there are further conserved Noether currents. In its method the paper
reconstructs the clue introduced by Utiyama (1956, 1959) and followed by
Al-Kuwari and Taha (1991) in the presence of a gauge field that depends on the
co-ordinates of the velocity space. In this course we apply certain (but not
full) analogies with Mills (1989). We show, that handling the space-time
coordinates as implicit variables in the gauge field, reproduces the same
results that have been derived in the configuration space (i.e., we do not lose
information), while the proposed new treatment gives additional information
extending those. The result is an extra conserved Noether current.


title: Universal fluctuations in the relaxation of structural glasses

abstract:
  The presence of strong local fluctuations -- dynamical heterogeneities -- has
been observed near the glass transitions of a wide variety of materials. Here
we explore the possible presence of universality in those fluctuations. We
compare the statistical properties of fluctuations obtained from numerical
simulations of four different glass-forming systems: two polymer systems and
two particle systems. We find strong evidence for universality, both in the
qualitative behavior of the fluctuations and in the remarkable agreement of the
scaling functions describing them.


title: Towards Holographic Renormalization of Fake Supergravity

abstract:
  A step is made towards generalizing the method of holographic renormalization
to backgrounds which are not asymptotically AdS, corresponding to a dual gauge
theory which has logarithmically running couplings even in the ultraviolet. A
prime example is the background of Klebanov-Strassler (KS). In particular, a
recipe is given how to calculate renormalized two-point functions for the
operators dual to the bulk scalars. The recipe makes use of gauge-invariant
variables for the fluctuations around the background and works for any bulk
theory of the fake supergravity type. It elegantly incorporates the
renormalization scheme dependence of local terms in the correlators. Before
applying the method to the KS theory, it is verified that known results in
asymptotically AdS backgrounds are reproduced. Finally, some comments on the
calculation of renormalized vacuum expectation values are made.


title: Dyson's theorem for curves

abstract:
  Let $\scriptstyle K$ be a number field and $\scriptstyle X_1$ and
$\scriptstyle X_2$ two smooth projective curves defined over it. In this paper
we prove an analogue of the Dyson Theorem for the product $\scriptstyle X_1
\times X_2$. If $\scriptstyle X_i = {\bb P}_1$ we find the classical Dyson
theorem. In general, it will imply a self contained and easy proof of Siegel
theorem on integral points on hyperbolic curves and it will give some insight
on effectiveness. This proof is new and avoids the use of Roth and Mordell-Weil
theorems, the theory of Linear Forms in Logarithms and the Schmidt subspace
theorem.


title: Erratum on "Hadamard spaces with isolated flats"

abstract:
  The purpose of this erratum is to correct the proof of Theorem A.0.1 in the
appendix to our article ``Hadamard spaces with isolated flats''
math.GR/0411232, which was jointly authored by Mohamad Hindawi, Hruska and
Kleiner. In that appendix, many of the results of math.GR/0411232 about CAT(0)
spaces with isolated flats are extended to a more general setting in which the
isolated subspaces are not necessarily flats. However, one step of that
extension does not follow from the argument we used the isolated flats setting.
We provide a new proof that fills this gap.
  In addition, we give a more detailed account of several other parts of
Theorem A.0.1, which were sketched in math.GR/0411232.


title:
Parallel Magnetic Field Tuning of Valley Splitting in AlAs
  Two-Dimensional Electrons

abstract:
  We demonstrate that, in a quasi-two-dimensional electron system confined to
an AlAs quantum well and occupying two conduction-band minima (valleys), a
parallel magnetic field can couple to the electrons' orbital motion and tune
the energies of the two valleys by different amounts. The measured density
imbalance between the two valleys, which is a measure of the valley
susceptibility with respect to parallel magnetic field, is enhanced compared to
the predictions of non-interacting calculations, reflecting the role of
electron-electron interaction.


title: Analytic subvarieties with many rational points

abstract:
  We give a generalization of the classical Bombieri--Schneider--Lang criterion
in transcendence theory. We give a local notion of $LG$--germ, which is similar
to the notion of $E$-- function and Gevrey condition, and which generalize (and
replace) the condition on derivatives in the theorem quoted above. Let
$K\subset \Bbb C$ be a number field and $X$ a quasi--projective variety defined
over $K$. Let $\gamma\colon M\to X$ be an holomorphic map of finite order from
a parabolic Riemann surface to $X$ such that the Zariski closure of the image
of it is strictly bigger then one. Suppose that for every $p\in
X(K)\cap\gamma(M)$ the formal germ of $M$ near $P$ is an $LG$-- germ, then we
prove that $X(K)\cap\gamma(M)$ is a finite set. Then we define the notion of
conformally parabolic Kh\"aler varieties; this generalize the notion of
parabolic Riemann surface. We show that on these varieties we can define a
value distribution theory. The complementary of a divisor on a compact Kh\"aler
manifold is conformally parabolic; in particular every quasi projective variety
is. Suppose that $A$ is conformally parabolic variety of dimension $m$ over
$\Bbb C$ with Kh\"aler form $\omega$ and $\gamma\colon A\to X$ is an
holomorphic map of finite order such that the Zariski closure of the image is
strictly bigger then $m$. Suppose that for every $p\in X(K)\cap \gamma (A)$,
the image of $A$ is an $LG$--germ. then we prove that there exists a current
$T$ on $A$ of bidegree $(1,1)$ such that $\int_AT\wedge\omega^{m-1}$ explicitly
bounded and with Lelong number bigger or equal then one on each point in
$\gamma^{-1}(X(K))$. In particular if $A$ is affine $\gamma^{-1}(X(K))$ is not
Zariski dense.


title: Reidemeister torsion and analytic torsion of discs

abstract:
  We study the Reidemeister torsion and the analytic torsion of the $m$
dimensional disc in the Euclidean $m$ dimensional space, using the base for the
homology defined by Ray and Singer in \cite{RS}. We prove that the Reidemeister
torsion coincides with a power of the volume of the disc. We study the
additional terms arising in the analytic torsion due to the boundary, using
generalizations of the Cheeger-M\"{u}ller theorem. We use a formula proved by
Br\"uning and Ma \cite{BM}, that predicts a new anomaly boundary term beside
the known term proportional to the Euler characteristic of the boundary
\cite{Luc}. Some of our results extend to the case of the cone over a sphere,
in particular we evaluate directly the analytic torsion for a cone over the
circle and over the two sphere. We compare the results obtained in the low
dimensional cases. We also consider a different formula for the boundary term
given by Dai and Fang \cite{DF}, and we show that the result obtained using
this formula is inconsistent with the direct calculation of the analytic
torsion.


title:
Hubble Space Telescope survey of the Perseus Cluster - I: The structure
  and dark matter content of cluster dwarf spheroidals

abstract:
  We present the results of a Hubble Space Telescope (HST) Advanced Camera for
Surveys (ACS) study of dwarf galaxies in the core of the rich nearby Perseus
Cluster, down to M_V=-12. We identify 29 dwarfs as cluster members, 17 of which
are previously unstudied. All the dwarfs we examine are remarkably smooth in
appearance, and lack internal features. Based on these observations, and the
sizes of these dwarfs, we argue that some of the dwarfs in our sample must have
a large dark matter content to prevent disruption by the cluster potential. We
derive a new method, independent of kinematics, for measuring the dark matter
content of dEs, based on the radius of the dwarf, the projected distance of the
dwarf from the cluster centre, and the total mass of the cluster interior to
it. We find that the mass-to-light ratios of these dwarfs are comparable to
those of the Local Group dSphs, ranging between 1 and 120.


title:
Hubble Space Telescope Survey of the Perseus Cluster: II. Photometric
  scaling relations in different environments

abstract:
  We investigate the global photometric scaling relations traced by early-type
galaxies in different environments, ranging from dwarf spheroidals, over dwarf
elliptical galaxies, up to giant ellipticals (-8 mag > M_V > -24 mag). These
results are based in part on our new HST/ACS F555W and F814W imagery of dwarf
spheroidal galaxies in the Perseus Cluster. These scaling relations are almost
independent of environment, with Local Group and cluster galaxies coinciding in
the various diagrams. We show that at M_V ~ -14 mag, the slopes of the
photometric scaling relations involving the Sersic parameters change
significantly. We argue that these changes in slope reflect the different
physical processes that dominate the evolution of early-type galaxies in
different mass regimes. As such, these scaling relations contain a wealth of
information that can be used to test models for the formation of early-type
galaxies.


title:
Periodic Solutions with Alternating Singularities in the Collinear
  Four-body Problem

abstract:
  This paper shows the existence of a periodic orbit with singularity in the
symmetric collinear four body problem. In each period of the orbit, there is a
binary collision (BC) between the inner two bodies and a simultaneous binary
collision (SBC) of the two clusters on both sides of the origin. The system is
regularized and the existence is proven by using the implicit function theorem
and a continuity argument on differential equations of the regularized
Hamiltonian.


title: Non-Factorizable Branes on the Torus

abstract:
  This work discusses string compactifications on the torus with optional Z_4 x
Z_4 or Z_2 x Z_2 orbifold action from the perspective of matrix factorizations.
The method is brought to a level where model building on these backgrounds is
possible. Whereas branes discussed in the literature typically wrap
factorizable cycles, that is cycles which are products of 1-cycles, branes
studied here can be in generic homology classes, can have arbitrary position
and Wilson line, have full complex structure respectively Kahler moduli
dependence and can be subject to any consistent orientifold action. It is shown
how any desired D-brane can be constructed systematically. Three-point
correlators can be computed as is demonstrated at hand of an example. Their
normalization is not discussed.


title:
Fabrication and Test of Pixelated CZT Detectors with Different Pixel
  Pitches and Thicknesses

abstract:
  The main methods grown Cadmium Zinc Telluride (CZT) crystals with high yield
and excellent homogeneity are Modified Horizontal Bridgman (MHB) and High
Pressure Bridgman (HPB) processes, respectively. In this contribution, the
readout system based on two 32-channel NCI-ASICs for pixellated CZT detector
arrays has been developed and tested. The CZT detectors supplied by Orbotech
(MHB) and eV products (HPB) are tested by NCI-ASIC readout system. The CZT
detectors have an array of 8x8 or 11x11 pixel anodes fabricated on the anode
surface with the area up to 2 cm x2 cm and the thickness of CZT detectors
ranges from 0.5 cm to 1 cm. Energy spectra resolution and electron
mobility-lifetime products of 8x8 pixels CZT detector with different
thicknesses have been investigated.


title:
Simple estimates on size of epidemics in generalized SIR-model for
  inhomogeneous populations

abstract:
  A generalization of Kermack-McKendick model of epidemics to the case of
inhomogeneous susceptibility of population is proposed. Some quantitative and
qualitative features of epidemic process development in this situation are
established.


title: Kinematic properties of early-type galaxy haloes using planetary nebulae

abstract:
  We present new planetary nebulae (PNe) positions, radial velocities, and
magnitudes for 6 early-type galaxies obtained with the Planetary Nebulae
Spectrograph, their two-dimensional velocity and velocity dispersion fields. We
extend this study to include an additional 10 early-type galaxies with PNe
radial velocity measurements available from the literature, to obtain a broader
description of the outer-halo kinematics in early-type galaxies. These data
extend the information derived from stellar kinematics to typically up to ~8
Re. The combination of photometry, stellar and PNe kinematics shows: i) good
agreement between the PNe number density and the stellar surface brightness in
the region where the two data sets overlap; ii) good agreement between PNe and
stellar kinematics; iii) that the mean rms velocity profiles fall into two
groups: with of the galaxies characterized by slowly decreasing profiles and
the remainder having steeply falling profiles; iv) a larger variety of velocity
dispersion profiles; v) that twists and misalignments in the velocity fields
are more frequent at large radii, including some fast rotators; vi) that outer
haloes are characterised by more complex radial profiles of the specific
angular momentum-related lambda_R parameter than observed within 1Re; vii) that
many objects are more rotationally dominated at large radii than in their
central parts; and viii) that the halo kinematics are correlated with other
galaxy properties, such as total luminosity, isophotal shape, total stellar
mass, V/sigma, and alpha parameter, with a clear separation between fast and
slow rotators.


title: The location and kinematics of the coronal-line emitting regions in AGN

abstract:
  We use the photoionisation code Cloudy to determine both the location and the
kinematics of the optical forbidden, high ionisation line (hereafter, FHIL)
emitting gas in the narrow line Seyfert 1 galaxy Ark 564. The results of our
models are compared with the observed properties of these emission lines to
produce a physical model that is used to explain both the kinematics and the
source of this gas. The main features of this model are that the FHIL emitting
gas is launched from the putative dusty torus and is quickly accelerated to its
terminal velocity of a few hundred km/s. Iron-carrying grains are destroyed
during this initial acceleration. This velocity is maintained by a balance
between radiative forces and gravity in this super-Eddington source. Eventually
the outflow is slowed at large radii by the gravitational forces of and
interactions with the host galaxy. In this model, FHIL emission traces the
transition between the AGN and bulge zones of influence.


abstract:
  A summary of JENAM 2008 Symposium 9 "Star Formation from Spitzer (Lyman) to
Spitzer (Space Telescope) and Beyond", held in Vienna, 10-12 September 2008.


title: Phenomenology of SUSY with scalar sequestering

abstract:
  The defining feature of scalar sequestering is that the MSSM squark and
slepton masses as well as all entries of the scalar Higgs mass matrix vanish at
some high scale. This ultraviolet boundary condition - scalar masses vanish
while gaugino and Higgsino masses are unsuppressed - is independent of the
supersymmetry breaking mediation mechanism. It is the result of renormalization
group scaling from approximately conformal strong dynamics in the hidden
sector. We review the mechanism of scalar sequestering and prove that the same
dynamics which suppresses scalar soft masses and the B_mu term also drives the
Higgs soft masses to -|mu|^2. Thus the supersymmetric contribution to the Higgs
mass matrix from the mu-term is exactly canceled by the soft masses. Scalar
sequestering has two tell-tale predictions for the superpartner spectrum in
addition to the usual gaugino mediation predictions: Higgsinos are much heavier
(mu > TeV) than scalar Higgses (m_A ~ few hundred GeV), and third generation
scalar masses are enhanced because of new positive contributions from Higgs
loops.


title:
Constructing the Tree-Level Yang-Mills S-Matrix Using Complex
  Factorization

abstract:
  A remarkable connection between BCFW recursion relations and constraints on
the S-matrix was made by Benincasa and Cachazo in 0705.4305, who noted that
mutual consistency of different BCFW constructions of four-particle amplitudes
generates non-trivial (but familiar) constraints on three-particle coupling
constants --- these include gauge invariance, the equivalence principle, and
the lack of non-trivial couplings for spins >2. These constraints can also be
derived with weaker assumptions, by demanding the existence of four-point
amplitudes that factorize properly in all unitarity limits with complex
momenta. From this starting point, we show that the BCFW prescription can be
interpreted as an algorithm for fully constructing a tree-level S-matrix, and
that complex factorization of general BCFW amplitudes follows from the
factorization of four-particle amplitudes. The allowed set of BCFW deformations
is identified, formulated entirely as a statement on the three-particle sector,
and using only complex factorization as a guide. Consequently, our analysis
based on the physical consistency of the S-matrix is entirely independent of
field theory. We analyze the case of pure Yang-Mills, and outline a proof for
gravity. For Yang-Mills, we also show that the well-known scaling behavior of
BCFW-deformed amplitudes at large z is a simple consequence of factorization.
For gravity, factorization in certain channels requires asymptotic behavior
~1/z^2.


title: Quantum algorithms for highly non-linear Boolean functions

abstract:
  Attempts to separate the power of classical and quantum models of computation
have a long history. The ultimate goal is to find exponential separations for
computational problems. However, such separations do not come a dime a dozen:
while there were some early successes in the form of hidden subgroup problems
for abelian groups--which generalize Shor's factoring algorithm perhaps most
faithfully--only for a handful of non-abelian groups efficient quantum
algorithms were found. Recently, problems have gotten increased attention that
seek to identify hidden sub-structures of other combinatorial and algebraic
objects besides groups. In this paper we provide new examples for exponential
separations by considering hidden shift problems that are defined for several
classes of highly non-linear Boolean functions. These so-called bent functions
arise in cryptography, where their property of having perfectly flat Fourier
spectra on the Boolean hypercube gives them resilience against certain types of
attack. We present new quantum algorithms that solve the hidden shift problems
for several well-known classes of bent functions in polynomial time and with a
constant number of queries, while the classical query complexity is shown to be
exponential. Our approach uses a technique that exploits the duality between
bent functions and their Fourier transforms.


title: H\alpha spectropolarimetry of RY Tau and PX Vul

abstract:
  Aims: To detect line effects using spectropolarimetry in order to find
evidence of rotating disks and their respective symmetry axes in T Tauri stars.
Methods: We used the IAGPOL imaging polarimeter along with the Eucalyptus-IFU
to obtain spectropolarimetric measurements of the T Tauri stars RY Tau (two
epochs) and PX Vul (one epoch). Evidence of line effects showing a loop on the
Q-U diagram favors a compact rather than an extended source for the line
photons in a rotating disk. In addition, the polarization position angle (PA)
obtained using the line effect can constrain the symmetry axis of the disk.
Results: RY Tau shown a variable Halpha double peak on 2004-2005 data.
Polarization line effect is evident on the Q-U diagram for both epochs
confirming a clockwise rotating disk. A single loop is evident on 2004 changing
to a linear excursion plus a loop on 2005. Interestingly, the intrinsic PA
calculated using the line effect is consistent between our two epochs
(~167deg). An alternative intrinsic PA computed from the interstellar
polarization corrected continuum and averaged between 2001-2005 yielded a PA
137deg. This last value is closer to be perpendicular to the observed disk
direction (~25deg) as expected by single scattering in an optically thin disk.
For PX Vul, we detected spectral variability in Halpha along with non-variable
continuum polarization when compared with previous data. The Q-U diagram shows
a well-defined loop in Halpha associated to a counter-clockwise rotating disk.
The symmetry axis inferred by the line effect has a PA~91deg (with an ambiguity
of 90deg). Our results confirm previous evidence that the emission line in T
Tauri stars has its origin in a compact source scattered off a rotating
accretion disk.


title: Consistency Conditions on S-Matrix of Spin 1 Massless Particles

abstract:
  Motivated by new techniques in the computation of scattering amplitudes of
massless particles in four dimensions, like BCFW recursion relations, the
question of how much structure of the S-matrix can be determined from purely
S-matrix arguments has received new attention. The BCFW recursion relations for
massless particles of spin 1 and 2 imply that the whole tree-level S-matrix can
be determined in terms of three-particle amplitudes (evaluated at complex
momenta). However, the known proofs of the validity of the relations rely on
the Lagrangian of the theory, either by using Feynman diagrams explicitly or by
studying the effective theory at large complex momenta. This means that a
purely S-matrix theoretic proof of the relations is still missing. The aim of
this paper is to provide such a proof for spin 1 particles by extending the
four-particle test introduced by P. Benincasa and F. Cachazo in
arXiv:0705.4305[hep-th] to all particles. We show how n-particle tests imply
that the rational function built from the BCFW recursion relations possesses
all the correct factorization channels including holomorphic and
anti-holomorphic collinear limits. This in turn implies that they give the
correct S-matrix of the theory.


title: Photometric redshifts for the CFHTLS-Wide

abstract:
  We want to derive bias free, accurate photometric redshifts for those fields
of the CFHTLS-Wide data which are covered in the u*, g', r', i' and z' filters
and are public on January 2008. These are 37 square degrees in the W1, W3 and
W4 fields with photometric data for a total of 2.597.239 galaxies. We use the
photometric redshift code PHOTO-z of Bender et al. (2001). We compare our
redshifts for the W1, W3 and W4 fields to about 7500 spectroscopic redshifts
from the VVDS therein. For galaxies with 17.5 <= i' AB <= 22.5 the accuracies
and outlier rates become sigma=0.033, eta~2 % for W1, sigma=0.037, eta~2% for
W3 and sigma=0.035, eta~2.5 % outliers for W4 fields. For the total galaxy
sample with about 9000 spectroscopic redshifts from VVDS, DEEP2 or SDSS we
obtain a sigma=0.04 and eta~5.7% for the PHOTO-z redshifts. We consider the
photometric redshifts of Erben et al. (2008) which were obtained with exactly
the same photometric catalog using the BPZ-redshift code and compare them with
our computed redshifts. We also merge the subsample with good photometric
redshifts from PHOTO-z with that one from BPZ to obtain a sample which then
contains 'secure' redshifts according to both the PHOTO-z and the BPZ codes.
This sample contains about 6100 spectra and the photometric redshift qualities
become sigma=0.037 and eta~1.0% for our PHOTO-z redshifts. We conclude that
this work provides a bias free, low dispersion photometric redshift catalog,
that we have criteria at hand to select a 'robust' subsample with fewer
outliers. Such a subsample is very useful to study the redshift dependent
growth of the dark matter fluctuations with weak lensing cosmic shear analyses
or to investigate the redshift dependent weak lensing signal behind clusters of
galaxies in the framework of dark energy equation of state constraints.


title:
Absence of structural correlations of magnetic defects in heavy fermion
  LiV2O4

abstract:
  Magnetic defects have pronounced effects on the magnetic properties of the
face-centered cubic compound LiV2O4. The magnetic defects arise from crystal
defects present within the normal spinel structure. High-energy x-ray
diffraction studies were performed on LiV2O4 single crystals to search for
superstructure peaks or any other evidence of periodicity in the arrangement of
the crystal defects present in the lattice. Entire reciprocal lattice planes
are mapped out with help of synchrotron radiation. No noticeable differences in
the x-ray diffraction data between a crystal with high magnetic defect
concentration and a crystal with low magnetic defect concentration have been
found. This indicates the absence of any long-range periodicity or short-range
correlations in the arrangements of the crystal/magnetic defects.


title: No evidence for mass segregation in massive young clusters

abstract:
  Aims. We investigate the validity of the mass segregation indicators commonly
used in analysing young stellar clusters. Methods. We simulate observations by
constructing synthetic seeing-limited images of a 1000 massive clusters (10^4
Msun) with a standard IMF and a King-density distribution function. Results. We
find that commonly used indicators are highly sensitive to sample
incompleteness in observational data and that radial completeness
determinations do not provide satisfactory corrections, rendering the studies
of radial properties highly uncertain. On the other hand, we find that, under
certain conditions, the global completeness can be estimated accurately,
allowing for the correction of the global luminosity and mass functions of the
cluster. Conclusions. We argue that there is currently no observational
evidence of mass segregation in young compact clusters since there is no robust
way to differentiate between true mass segregation and sample incompleteness
effects. Caution should then be exercised when interpreting results from
observations as evidence of mass segregation.


title: Angular momentum and clustering properties of early dark matter halos

abstract:
  In this paper we study the angular momentum properties of simulated dark
matter halos at high redshift that likely host the first stars in the Universe.
Calculating the spin distributions of these $10^6 - 10^7 \Msun$ halos in
redshift slices from $z = 15 - 6$, we find that they are well fit by a
log-normal distribution as is found for lower redshift and more massive halos
in earlier work. We find that both the mean value of the spin and dispersion
are largely unchanged with redshift for all halos. Our key result is that
subsamples of low and high spin $10^6 \Msun$ and $10^7 \Msun$ halos show
difference in clustering strength. In both mass bins, higher spin halos are
more strongly clustered in concordance with a tidal torquing picture for the
growth of angular momentum in dark matter halos in the CDM paradigm.


title: Computads and Multitopic Sets

abstract:
  We compare computads with multitopic sets. Both these kinds of structures
have n-dimensional objects (called n-cells and n-pasting diagrams,
respectively). The computads form a subclass of the more familiar class of
omega-categories, while multitopic sets have been devised by Hermida, Makkai
and Power as a vehicle for a definition of the concepts of weak omega-category.
Our main result states that the category of multitopic sets is equivalent to
that of many-to-one computads, a certain full subcategory of the category of
all computads.


title: Alignment of galaxy spins in the vicinity of voids

abstract:
  We provide limits on the alignment of galaxy orientations with the direction
to the void center for galaxies lying near the edges of voids. We locate
spherical voids in volume limited samples of galaxies from the Sloan Digital
Sky Survey using the HB inspired void finder and investigate the orientation of
(color selected) spiral galaxies that are nearly edge-on or face-on. In
contrast with previous literature, we find no statistical evidence for
departure from random orientations. Expressed in terms of the parameter c,
introduced by Lee & Pen to describe the strength of such an alignment, we find
that c<0.11(0.13) at 95% (99.7%) confidence limit within a context of a toy
model that assumes a perfectly spherical voids with sharp boundaries.


title: Impact of sub-solar metallicities on photometric redshifts

abstract:
  With the advent of deep photometric surveys the use of photometric redshifts,
obtained with a variety of techniques, has become more and more widespread.
Giving access to galaxies with a wide range of luminosities out to high
redshifts, these surveys include many faint galaxies with significantly
sub-solar metallicities.
  We use our chemically consistent galaxy evolutionary synthesis code GALEV to
produce a large grid of template Spectral Energy Distributions (SEDs) for
galaxies of spectral types E and Sa through Sd - one accounting in a chemically
consistent way for the increasing initial metallicities of successive stellar
generations, the other one for exclusively solar metallicities - for
comparison.
  We use our new photometric redshift code GAZELLE based on the comparison of
observed and model SEDs. Comparing the photometric redshifts obtained using
solar metallicity templates when working on a catalogue of artificially created
chemically consistent SEDs, typical for low-metallicity local late-type
galaxies and for intrinsically low-luminosity, and hence low-metallicity,
galaxies in the high-redshift universe, we find a significant bias resulting
from this metallicity mismatch. This bias consists in a systematic
underestimate of the photometric redshift by typically Delta z ~ 0.1 ... 0.2
until z ~ 1.2, depending on galaxy type, of distant, faint and low-metallicity
galaxies if analysed with solar-metallicity templates.


title: Extended scaling relations for planar lattice models

abstract:
  It is widely believed that the critical properties of several planar lattice
models, like the Eight Vertex or the Ashkin-Teller models, are well described
by an effective Quantum Field Theory obtained as formal scaling limit. On the
basis of this assumption several extended scaling relations among their indices
were conjectured. We prove the validity of some of them, among which the ones
by Kadanoff, [K], and by Luther and Peschel, [LP].


title: Ramification and moduli spaces of finite flat models

abstract:
  We determine the type of the zeta functions and the range of the dimensions
of the moduli spaces of finite flat models of two-dimensional local Galois
representations over finite fields. This gives a generalization of Raynaud's
theorem on the uniqueness of finite flat models in low ramifications.


title: Layered Kondo lattice model for quantum critical beta-YbAlB4

abstract:
  We analyze the magnetic and electronic properties of the quantum critical
heavy fermion superconductor beta-YbAlB4, calculating the Fermi surface and the
angular dependence of the extremal orbits relevant to the de Haas--van Alphen
measurements. Using a combination of the realistic materials modeling and
single-ion crystal field analysis, we are led to propose a layered Kondo
lattice model for this system, in which two dimensional boron layers are Kondo
coupled via interlayer Yb moments in a $J_{z}=\pm 5/2$ state. This model fits
the measured single ion magnetic susceptibility and predicts a substantial
change in the electronic anisotropy as the system is pressure-tuned through the
quantum critical point.


title:
The chromospherically active binary star EI Eridani II. Long-term
  Doppler imaging

abstract:
  Data from 11 years of continuous spectroscopic observations of the active RS
CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed
and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in
three spectroscopic lines for 32 epochs, 28 of which are independent of each
other. Various parameters are extracted from our Doppler maps: average
temperature, fractional spottedness, and longitudinal and latitudinal
spot-occurrence functions. We find that none of these parameters show a
distinct variation nor a correlation with the proposed activity cycle as seen
from photometric long-term observations. This suggests that the photometric
brightness cycle may not necessarily be due to just a cool spot cycle. The
general morphology of the spot pattern remains persistent over the whole period
of 11 years. A large cap-like polar spot was recovered from all our images. A
high degree of variable activity was noticed near latitudes of approx. 60-70
degrees where the appendages of the polar spot emerged and dissolved.


title: Tunneling between edge states in a quantum spin Hall system

abstract:
  We analyze a quantum spin Hall (QSH) device with a point contact connecting
two of its edges. The contact supports a net spin tunneling current that can be
probed experimentally via a two-terminal resistance measurement. We find that
the low-bias tunneling current and the differential conductance exhibit scaling
with voltage and temperature that depend nonlinearly on the strength of the
electron-electron interaction.


title: Wide Area X-ray Surveys for AGN and Starburst Galaxies

abstract:
  While often the point sources in X-ray surveys are dominated by AGN, with the
high sensitivity of modern X-ray telescopes such as Chandra and XMM-Newton
normal/starburst galaxies are also being detected in large numbers. We have
made use of Bayesian statistics for both the selection of galaxies from deep
X-ray surveys and in the analysis of the luminosity functions for galaxies.
These techniques can be used to similarly select galaxies from wide-area X-ray
surveys and to analyze their luminosity function. The prospects for detecting
galaxies and AGN from a proposed ``wide-deep'' XMM-Newton survey and from
future wide-area X-ray survey missions (such as WFXT and eRosita) are also
discussed.


title:
Precision measurements, dark matter direct detection and LHC Higgs
  searches in a constrained NMSSM

abstract:
  We reexamine the constrained version of the Next-to-Minimal Supersymmetric
Standard Model with semi universal parameters at the GUT scale (CNMSSM). We
include constraints from collider searches for Higgs and SUSY particles, upper
bound on the relic density of dark matter, measurements of the muon anomalous
magnetic moment and of B-physics observables as well as direct searches for
dark matter. We then study the prospects for direct detection of dark matter in
large scale detectors and comment on the prospects for discovery of heavy Higgs
states at the LHC.


title:
Rational Periodic Points for Degree Two Polynomial Morphisms on
  Projective Space

abstract:
  This article addresses the existence of $\Q$-rational periodic points for
morphisms of projective space. In particular, we construct an infinitely family
of morphisms on $\P^N$ where each component is a degree 2 homogeneous form in
$N+1$ variables which has a $\Q$-periodic point of primitive period
$\frac{(N+1)(N+2)}{2} + \lfloor \frac{N-1}{2}\rfloor$. This result is then used
to show that for $N$ large enough there exists morphisms of $\P^N$ with
$\Q$-rational periodic points with primitive period larger that $c(k)N^k$ for
any $k$ and some constant $c(k)$.


title: Comprehensive Observations of a Solar Minimum CME with STEREO

abstract:
  We perform the first kinematic analysis of a CME observed by both imaging and
in situ instruments on board STEREO, namely the SECCHI, PLASTIC, and IMPACT
experiments. Launched on 2008 February 4, the CME is tracked continuously from
initiation to 1 AU using the SECCHI imagers on both STEREO spacecraft, and is
then detected by the PLASTIC and IMPACT particle and field detectors on board
STEREO-B. The CME is also detected in situ by ACE and SOHO/CELIAS at Earth's L1
Lagrangian point. The CME hits STEREO-B, ACE, and SOHO on 2008 February 7, but
misses STEREO-A entirely. This event provides a good example of just how
different the same event can look when viewed from different perspectives. We
also demonstrate many ways in which the comprehensive and continuous coverage
of this CME by STEREO improves confidence in our assessment of its kinematic
behavior, with potential ramifications for space weather forecasting. The
observations provide several lines of evidence in favor of the observable part
of the CME being narrow in angular extent, a determination crucial for deciding
how best to convert observed CME elongation angles from Sun-center to actual
Sun-center distances.


title:
Inverse pressure estimates and the independence of stable dimension for
  non-invertible maps

abstract:
  We use the inverse pressure concept to estimate the stable dimension for
hyperbolic non-invertible maps which are conformal in the stable fibers. The
non-invertible case is different than the diffeomorphism case. In particular we
show that if the map is open on the respective basic set, then the stable
dimension is constant everywhere. We prove also in this setting the Lipschitz
continuity of the stable distribution.


title:
Fast and reasonable Installation, Experience and Acceptance of a Remote
  Control Room

abstract:
  Remote control systems are becoming more and more important to give us the
flexibility to control facilities, provide assistance and intervene in case of
problems at any time and from every place. As a global operating group CALICE
[2] with approx. 220 members worldwide is dependent on using a remote control
system for shifts and monitoring of the data taking. CALICE has at present
installed its detector at Fermilab, Chicago, where will run test beam
experiments for the next year. The components of the remote control system and
kind of use are presented here.


title: Supercoil formation in DNA denaturation

abstract:
  We generalize the Poland-Scheraga (PS) model to the case of a circular DNA,
taking into account the twisting of the two strains around each other. Guided
by recent single-molecule experiments on DNA strands, we assume that the
torsional stress induced by denaturation enforces formation of supercoils whose
writhe absorbs the linking number expelled by the loops. Our model predicts
that, when the entropy parameter of a loop satisfies $c \le 2$, denaturation
transition does not take place. On the other hand for $c>2$ a first-order
denaturation transition is consistent with our model and may take place in the
actual system, as in the case with no supercoils. These results are in contrast
with other treatments of circular DNA melting where denaturation is assumed to
be accompanied by an increase in twist rather than writhe on the bound
segments.


title: Diffuse Extragalactic Background Radiation

abstract:
  Attenuation of high--energy gamma rays by pair--production with UV, optical
and IR background photons provides a link between the history of galaxy
formation and high--energy astrophysics. We present results from our latest
semi-analytic models (SAMs), based upon a $\Lambda$CDM hierarchical structural
formation scenario and employing all ingredients thought to be important to
galaxy formation and evolution, as well as reprocessing of starlight by dust to
mid- and far-IR wavelengths. Our models also use results from recent
hydrodynamic galaxy merger simulations. These latest SAMs are successful in
reproducing a large variety of observational constraints such as number counts,
luminosity and mass functions, and color bimodality. We have created 2 models
that bracket the likely ranges of galaxy emissivities, and for each of these we
show how the optical depth from pair--production is affected by redshift and
gamma-ray energy. We conclude with a discussion of the implications of our
work, and how the burgeoning science of gamma-ray astronomy will continue to
help constrain cosmology.


title: A Rational Deconstruction of Landin's SECD Machine with the J Operator

abstract:
  Landin's SECD machine was the first abstract machine for applicative
expressions, i.e., functional programs. Landin's J operator was the first
control operator for functional languages, and was specified by an extension of
the SECD machine. We present a family of evaluation functions corresponding to
this extension of the SECD machine, using a series of elementary
transformations (transformation into continu-ation-passing style (CPS) and
defunctionalization, chiefly) and their left inverses (transformation into
direct style and refunctionalization). To this end, we modernize the SECD
machine into a bisimilar one that operates in lockstep with the original one
but that (1) does not use a data stack and (2) uses the caller-save rather than
the callee-save convention for environments. We also identify that the dump
component of the SECD machine is managed in a callee-save way. The caller-save
counterpart of the modernized SECD machine precisely corresponds to Thielecke's
double-barrelled continuations and to Felleisen's encoding of J in terms of
call/cc. We then variously characterize the J operator in terms of CPS and in
terms of delimited-control operators in the CPS hierarchy. As a byproduct, we
also present several reduction semantics for applicative expressions with the J
operator, based on Curien's original calculus of explicit substitutions. These
reduction semantics mechanically correspond to the modernized versions of the
SECD machine and to the best of our knowledge, they provide the first syntactic
theories of applicative expressions with the J operator.


title: Heavy flavour in ALICE

abstract:
  The ALICE experiment, currently in the commissioning phase, will study
nucleus-nucleus and proton-proton collisions at the CERN Large Hadron Collider
(LHC). We review the ALICE heavy-flavour physics program.


title: Cubefree words with many squares

abstract:
  We construct infinite cubefree binary words containing exponentially many
distinct squares of length n. We also show that for every positive integer n,
there is a cubefree binary square of length 2n.


title: On the gravitational content of molecular clouds and their cores

abstract:
  (Abridged) The gravitational term for clouds and cores entering in the virial
theorem is usually assumed to be equal to the gravitational energy, since the
contribution to the gravitational force from the mass distribution outside the
volume of integration is assumed to be negligible. Such approximation may not
be valid in the presence of an important external net potential. In the present
work we analyze the effect of an external gravitational field on the
gravitational budget of a density structure. Our cases under analysis are (a) a
giant molecular cloud (GMC) with different aspect ratios embedded within a
galactic net potential, and (b) a molecular cloud core embedded within the
gravitational potential of its parent molecular cloud. We find that for
roundish GMCs, the tidal tearing due to the shear in the plane of the galaxy is
compensated by the tidal compression in the z direction. The influence of the
external effective potential on the total gravitational budget of these clouds
is relatively small, although not necessarily negligible. However, for more
filamentary GMCs, the external effective potential can be dominant and can even
overwhelm self-gravity, regardless of whether its main effect on the cloud is
to disrupt it or compress it. This may explain the presence of some GMCs with
few or no signs of massive star formation, such as the Taurus or the
Maddalena's clouds. In the case of dense cores embedded in their parent
molecular cloud, we found that the gravitational content due to the external
field may be more important than the gravitational energy of the cores
themselves. This effect works in the same direction as the gravitational
energy, i.e., favoring the collapse of cores. We speculate on the implications
of these results for star formation models.


title: On the group of strong symplectic homeomorphisms

abstract:
  We generalize the "hamiltonian topology" on hamiltonian isotopies to an
intrinsic "symplectic topology" on the space of symplectic isotopies. We use it
to define the group $SSympeo(M,\omega)$ of strong symplectic homeomorphisms,
which generalizes the group $Hameo(M,\omega)$ of hamiltonian homeomorphisms
introduced by Oh and Muller. The group $SSympeo(M,\omega)$ is arcwise
connected, is contained in the identity component of $Sympeo(M,\omega)$; it
contains $Hameo(M,\omega)$ as a normal subgroup and coincides with it when $M$
is simply connected. Finally its commutator subgroup
$[SSympeo(M,\omega),SSympeo(M,\omega)]$ is contained in $Hameo(M,\omega)$.


title: Electron-nuclear interaction in 13C nanotube double quantum dots

abstract:
  For coherent electron spins, hyperfine coupling to nuclei in the host
material can either be a dominant source of unwanted spin decoherence or, if
controlled effectively, a resource allowing storage and retrieval of quantum
information. To investigate the effect of a controllable nuclear environment on
the evolution of confined electron spins, we have fabricated and measured
gate-defined double quantum dots with integrated charge sensors made from
single-walled carbon nanotubes with a variable concentration of 13C (nuclear
spin I=1/2) among the majority zero-nuclear-spin 12C atoms. Spin-sensitive
transport in double-dot devices grown using methane with the natural abundance
(~ 1%) of 13C is compared with similar devices grown using an enhanced (~99%)
concentration of 13C. We observe strong isotope effects in spin-blockaded
transport, and from the dependence on external magnetic field, estimate the
hyperfine coupling in 13C nanotubes to be on the order of 100 micro-eV, two
orders of magnitude larger than anticipated theoretically. 13C-enhanced
nanotubes are an interesting new system for spin-based quantum information
processing and memory, with nuclei that are strongly coupled to gate-controlled
electrons, differ from nuclei in the substrate, are naturally confined to one
dimension, lack quadrupolar coupling, and have a readily controllable
concentration from less than one to 10^5 per electron.


title: Measurement of heavy-flavour production in ALICE

abstract:
  The ALICE experiment, currently in the commissioning phase, will study
nucleus-nucleus and proton-proton collisions at the CERN Large Hadron Collider
(LHC). We review the ALICE heavy-flavour physics program and present a
selection of results on the expected performance for the case of proton-proton
collisions.


title: On Pebbling Graphs by their Blocks

abstract:
  Graph pebbling is a game played on a connected graph G. A player purchases
pebbles at a dollar a piece, and hands them to an adversary who distributes
them among the vertices of G (called a configuration) and chooses a target
vertex r. The player may make a pebbling move by taking two pebbles off of one
vertex and moving one pebble to a neighboring vertex. The player wins the game
if he can move k pebbles to r. The value of the game (G,k), called the
k-pebbling number of G, is the minimum cost to the player to guarantee a win.
That is, it is the smallest positive integer m of pebbles so that, from every
configuration of size m, one can move k pebbles to any target. In this paper,
we use the block structure of graphs to investigate pebbling numbers, and we
present the exact pebbling number of the graphs whose blocks are complete. We
also provide an upper bound for the k-pebbling number of diameter-two graphs,
which can be the basis for further investigation into the pebbling numbers of
graphs with blocks that have diameter at most two.


title:
Relaxation and Dephasing in a Two-electron 13C Nanotube Double Quantum
  Dot

abstract:
  We use charge sensing of Pauli blockade (including spin and isospin) in a
two-electron 13C nanotube double quantum dot to measure relaxation and
dephasing times. The relaxation time, T1, first decreases with parallel
magnetic field then goes through a minimum in a field of 1.4 T. We attribute
both results to the spin-orbit-modified electronic spectrum of carbon
nanotubes, which suppresses hyperfine mediated relaxation and enhances
relaxation due to soft phonons. The inhomogeneous dephasing time, T2*, is
consistent with previous data on hyperfine coupling strength in 13C nanotubes.


title: Complete, Single-Horizon Quantum Corrected Black Hole Spacetime

abstract:
  We show that a semi-classical polymerization of the interior of Schwarzschild
black holes gives rise to a tantalizing candidate for a non-singular, single
horizon black hole spacetime. The exterior has non-zero quantum stress energy
but closely approximates the classical spacetime for macroscopic black holes.
The interior exhibits a bounce at a microscopic scale and then expands
indefinitely to a Kantowski-Sachs spacetime. Polymerization therefore removes
the singularity and produces a scenario reminiscent of past proposals for
universe creation via quantum effects inside a black hole.


title: Detecting integral polyhedral functions

abstract:
  We study the class of real-valued functions on convex subsets of R^n which
are computed by the maximum of finitely many affine functionals with integer
slopes. We prove several results to the effect that this property of a function
can be detected by sampling on small subsets of the domain. In so doing, we
recover in a unified way some prior results of the first author (some joint
with Liang Xiao). We also prove that a function on R^2 is a tropical polynomial
if and only if its restriction to each translate of a generic tropical line is
a tropical polynomial.


title: DC-readout of a signal-recycled gravitational wave detector

abstract:
  All first-generation large-scale gravitational wave detectors are operated at
the dark fringe and use a heterodyne readout employing radio frequency (RF)
modulation-demodulation techniques. However, the experience in the currently
running interferometers reveals several problems connected with a heterodyne
readout, of which phase noise of the RF modulation is the most serious one. A
homodyne detection scheme (DC-readout), using the highly stabilized and
filtered carrier light as local oscillator for the readout, is considered to be
a favourable alternative. Recently a DC-readout scheme was implemented on the
GEO 600 detector. We describe the results of first measurements and give a
comparison of the performance achieved with homodyne and heterodyne readout.
The implications of the combined use of DC-readout and signal-recycling are
considered.


title:
Statistical mechanics of Floquet systems: the pervasive problem of near
  degeneracies

abstract:
  The statistical mechanics of periodically driven ("Floquet") systems in
contact with a heat bath exhibits some radical differences from the traditional
statistical mechanics of undriven systems. In Floquet systems all quasienergies
can be placed in a finite frequency interval, and the number of near
degeneracies in this interval grows without limit as the dimension N of the
Hilbert space increases. This leads to pathologies, including drastic changes
in the Floquet states, as N increases. In earlier work these difficulties were
put aside by fixing N, while taking the coupling to the bath to be smaller than
any quasienergy difference. This led to a simple explicit theory for the
reduced density matrix, but with some major differences from the usual time
independent statistical mechanics. We show that, for weak but finite coupling
between system and heat bath, the accuracy of a calculation within the
truncated Hilbert space spanned by the N lowest energy eigenstates of the
undriven system is limited, as N increases indefinitely, only by the usual
neglect of bath memory effects within the Born and Markov approximations. As we
seek higher accuracy by increasing N, we inevitably encounter quasienergy
differences smaller than the system-bath coupling. We therefore derive the
steady state reduced density matrix without restriction on the size of
quasienergy splittings. In general, it is no longer diagonal in the Floquet
states. We analyze, in particular, the behavior near a weakly avoided crossing,
where quasienergy near degeneracies routinely appear. The explicit form of our
results for the denisty matrix gives a consistent prescription for the
statistical mechanics for many periodically driven systems with N infinite, in
spite of the Floquet state pathologies.


title:
Linear Time Approximation Schemes for the Gale-Berlekamp Game and
  Related Minimization Problems

abstract:
  We design a linear time approximation scheme for the Gale-Berlekamp Switching
Game and generalize it to a wider class of dense fragile minimization problems
including the Nearest Codeword Problem (NCP) and Unique Games Problem. Further
applications include, among other things, finding a constrained form of matrix
rigidity and maximum likelihood decoding of an error correcting code. As
another application of our method we give the first linear time approximation
schemes for correlation clustering with a fixed number of clusters and its
hierarchical generalization. Our results depend on a new technique for dealing
with small objective function values of optimization problems and could be of
independent interest.


title: Voting in agreeable societies

abstract:
  When can a majority of voters find common ground, that is, a position they
all agree upon? How does the shape of the political spectrum influence the
outcome? When mathematical objects have a social interpretation, the associated
theorems have social applications. In this article we give examples of
situations where sets model preferences and develop extensions of classical
theorems about convex sets, such as Helly's theorem, that can be used in the
analysis of voting in "agreeable" societies.


title:
Non-equilibrium structures and slow dynamics in a two dimensional spin
  system with competitive long range and short range interactions

abstract:
  We introduce a lattice spin model that mimics a system of interacting
particle through a short range repulsive potential and a long range attractive
power law decaying potential. We performed a detailed analysis of the general
equilibrium phase diagram of the model at finite temperature, showing that the
only possible equilibrium pases are the ferromagnetic and the antiferromagnetic
ones. We then studied the non equilibrium behavior of the model after a quench
to subcritical temperatures, in the antiferromagnetic region of the phase
diagram region, where the pair interaction potential behaves in the same
qualitative way as in a Lennard-Jones gas. We found that, even in the absence
of quenched disorder or geometric frustration, the competition between
interactions gives rise to non--equilibrium disordered structures at low enough
temperatures that strongly slow down the relaxation of the system.


title: An experimental analysis of Lemke-Howson algorithm

abstract:
  We present an experimental investigation of the performance of the
Lemke-Howson algorithm, which is the most widely used algorithm for the
computation of a Nash equilibrium for bimatrix games. Lemke-Howson algorithm is
based upon a simple pivoting strategy, which corresponds to following a path
whose endpoint is a Nash equilibrium. We analyze both the basic Lemke-Howson
algorithm and a heuristic modification of it, which we designed to cope with
the effects of a 'bad' initial choice of the pivot. Our experimental findings
show that, on uniformly random games, the heuristics achieves a linear running
time, while the basic Lemke-Howson algorithm runs in time roughly proportional
to a polynomial of degree seven. To conduct the experiments, we have developed
our own implementation of Lemke-Howson algorithm, which turns out to be
significantly faster than state-of-the-art software. This allowed us to run the
algorithm on a much larger set of data, and on instances of much larger size,
compared with previous work.


title:
Analytic Expressions for the Surface Brightness Profile of GRB Afterglow
  Images

abstract:
  The exact profile of a gamma-ray burst (GRB) afterglow image on the plane of
the sky can provide important constraints on the underlying physics. In
particular, it can test whether the magnetic field in the emitting shocked
external medium decreases significantly with the distance behind the shock
front, or remains roughly constant. Moreover, it enables more accurate
measurements of the afterglow image size and the expected scintillation
properties. In this work analytic expressions are derived for the afterglow
image in power law segments (PLSs) of the afterglow synchrotron spectrum in
which the emission originates from a very thin layer just behind the shock,
while simple semi-analytic expressions are derived for the remaining PLSs in
which the emission arises from the bulk of the shocked fluid. In all cases the
expressions are for a general power law external density profile, and are
convenient to use in afterglow studies.


title: Baryon polarization in low-energy unpolarized meson-baryon scattering

abstract:
  We compute the polarization of the final-state baryon, in its rest frame, in
low-energy meson--baryon scattering with unpolarized initial state, in
Unitarized BChPT. Free parameters are determined by fitting total and
differential cross-section data (and spin-asymmetry or polarization data if
available) for $pK^-$, $pK^+$ and $p\pi^+$ scattering. We also compare our
results with those of leading-order BChPT.


title: Vanishing conductivity of quantum solitons in polyacetylene

abstract:
  Quantum solitons or polarons are supposed to play a crucial role in the
electric conductivity of polyacetylene, in the intermediate doping regime. We
present an exact fully quantized calculation of the quantum soliton
conductivity in polyacetylene and show that it vanishes exactly. This is
obtained by applying a general method of soliton quantization, based on
order-disorder duality, to a Z(2)-symmetric complex extension of the TLM
dimerization effective field theory. We show that, in this theory,
polyacetylene solitons are sine-Gordon solitons in the phase of the complex
field.


title:
Radiation pressure force and black hole mass determination in low
  redshift type-I and type-II active galactic nuclei

abstract:
  The distributions of L(oiii 5007), black hole (BH) mass and L/L(Edd) in two
large samples of type-I and type-II active galactic nuclei (AGNs) are compared
in order to test the suggestion that radiation pressure force is affecting the
gas velocity in the broad line region and hence the BH mass determination. The
samples are drawn from the SDSS archive and are modified to represent the same
parent distribution at 0.1 < z < 0.2. BH masses in type-I sources are
calculated in two different ways, one using a simple virial mass assumption and
the other by taking into account the effect of radiation pressure force on the
gas. The simple virial mass estimate results in good agreement with the
sigma*-based BH mass and L/L(Edd) estimates in type-II sources. In contrast,
there is a clear disagreement in the L/L(Edd) distributions when radiation
pressure-based estimates are used. This indicates that radiation pressure force
is not important in 0.1 < z < 0.2 AGNs with L(5100)=10^{42.8-44.8} erg/s. This
has important implications to the physics of the gas producing the broad
emission lines in AGNs, in particular the existence of extremely large (about
10^24 cm^(-2)) column density clouds.


title: Boundary operators in the O(n) and RSOS matrix models

abstract:
  We study the new boundary condition of the O(n) model proposed by Jacobsen
and Saleur using the matrix model. The spectrum of boundary operators and their
conformal weights are obtained by solving the loop equations. Using the
diagrammatic expansion of the matrix model as well as the loop equations, we
make an explicit correspondence between the new boundary condition of the O(n)
model and the "alternating height" boundary conditions in RSOS model.


title:
Can a matter-dominated model with constant bulk viscosity drive the
  accelerated expansion of the universe?

abstract:
  We test a cosmological model which the only component is a pressureless fluid
with a constant bulk viscosity as an explanation for the present accelerated
expansion of the universe. We classify all the possible scenarios for the
universe predicted by the model according to their past, present and future
evolution and we test its viability performing a Bayesian statistical analysis
using the SCP ``Union'' data set (307 SNe Ia), imposing the second law of
thermodynamics on the dimensionless constant bulk viscous coefficient \zeta and
comparing the predicted age of the universe by the model with the constraints
coming from the oldest globular clusters.
  The best estimated values found for \zeta and the Hubble constant Ho are:
\zeta=1.922 \pm 0.089 and Ho=69.62 \pm 0.59 km/s/Mpc with a \chi^2=314. The age
of the universe is found to be 14.95 \pm 0.42 Gyr. We see that the estimated
value of Ho as well as of \chi^2 are very similar to those obtained from LCDM
model using the same SNe Ia data set. The estimated age of the universe is in
agreement with the constraints coming from the oldest globular clusters.
Moreover, the estimated value of \zeta is positive in agreement with the second
law of thermodynamics (SLT).
  On the other hand, we perform different forms of marginalization over the
parameter Ho in order to study the sensibility of the results to the way how Ho
is marginalized. We found that it is almost negligible the dependence between
the best estimated values of the free parameters of this model and the way how
Ho is marginalized in the present work. Therefore, this simple model might be a
viable candidate to explain the present acceleration in the expansion of the
universe.


title:
Covariant feedback Control of arbitrary qudit state against Depolarizing
  Noise is impossible

abstract:
  In this paper, we prove that it is impossible to construct a convariant
quantum feedback control instruments which aim to correct the channel noise
imposed on an unknown qubit. The proof is based on the searching for the
optimal quantum control protocol and it turns out there exist no better
%\textit{Complete Positive Trace %Preserving}(CPTP) maps complete positive and
covariant quantum operations which provide a higher fidelity than the trivial
Identity operators. The generalization of the investigation to bipartite
entangled pure state is also included.