title: The Host Galaxy and Central Engine of the Dwarf AGN POX 52

abstract:
  We present new multi-wavelength observations of the dwarf Seyfert 1 galaxy
POX 52 in order to investigate the properties of the host galaxy and the active
nucleus, and to examine the mass of its black hole, previously estimated to be
~ 10^5 M_sun. Hubble Space Telescope ACS/HRC images show that the host galaxy
has a dwarf elliptical morphology (M_I = -18.4 mag, Sersic index n = 4.3) with
no detected disk component or spiral structure, confirming previous results
from ground-based imaging. X-ray observations from both Chandra and XMM show
strong (factor of 2) variability over timescales as short as 500 s, as well as
a dramatic decrease in the absorbing column density over a 9 month period. We
attribute this change to a partial covering absorber, with a 94% covering
fraction and N_H = 58^{+8.4}_{-9.2} * 10^21 cm^-2, that moved out of the line
of sight in between the XMM and Chandra observations. Combining these data with
observations from the VLA, Spitzer, and archival data from 2MASS and GALEX, we
examine the spectral energy distribution (SED) of the active nucleus. Its shape
is broadly similar to typical radio-quiet quasar SEDs, despite the very low
bolometric luminosity of L_bol = 1.3 * 10^43 ergs/s. Finally, we compare black
hole mass estimators including methods based on X-ray variability, and optical
scaling relations using the broad H-beta line width and AGN continuum
luminosity, finding a range of black hole mass from all methods to be M_bh =
(2.2-4.2) * 10^5 M_sun, with an Eddington ratio of L_bol/L_edd = 0.2-0.5.


title:
Discrimination of nuclear recoils from alpha particles with superheated
  liquids

abstract:
  The PICASSO collaboration observed for the first time a significant
difference between the acoustic signals induced by neutrons and alpha particles
in a detector based on superheated liquids. This new discovery offers the
possibility of improved background suppression and could be especially useful
for dark matter experiments. This new effect may be attributed to the formation
of multiple bubbles on alpha tracks, compared to single nucleations created by
neutron induced recoils.


title: Resonance-like Goss-Haenchen Shift induced by nano-metal films

abstract:
  The influence of nano-metal films on the Goos-Haenchen shift (GHS) is
investigated. The films deposited at the total reflecting surface of a perspex
prism/air have a sheet resistance varying between Z = 25 and 3 000 Ohm. A
resonance-like enhancement of the shift and of the absorption is found for TE
polarized waves, when the sheet resistance approaches the value of the vacuum
impedance. For TM waves the influence of the metal films on the GHS is
comparatively weak. The experiments are carried out with microwaves. Keywords:
Goos-Haenchen shift; nano-metallic films, microwaves PACS: 42.25.Bs, 42.25.Gy,
42.50.-p, 73.40.Gk


title:
Information Content in the Galaxy Angular Power Spectrum from the Sloan
  Digital Sky Survey and Its Implication on Weak Lensing Analysis

abstract:
  We analyze the photometric redshift catalog of the Sloan Digital Sky Survey
Data Release 5 (SDSS DR5) to estimate the Fisher information in the galaxy
angular power spectrum with the help of the Rimes-Hamilton technique. It is
found that the amount of Fisher information contained in the galaxy angular
power spectrum is saturated at lensing multipole scale 300<= l <= 2000 in the
redshift range 0.1<= photo-z <0.5. At l=2000, the observed information is two
orders of magnitude lower than the case of Gaussian fluctuations. This supports
observationally that the translinear regime of the density power spectrum
contains little independent information about the initial cosmological
conditions, which is consistent with the numerical trend shown by
Rimes-Hamilton. Our results also suggest that the Gaussian-noise description
may not be valid in weak lensing measurements.


title:
On convergence of solutions to equilibria for quasilinear parabolic
  problems

abstract:
  We show convergence of solutions to equilibria for quasilinear parabolic
evolution equations in situations where the set of equilibria is non-discrete,
but forms a finite-dimensional $C^1$-manifold which is normally hyperbolic. Our
results do not depend on the presence of an appropriate Lyapunov functional as
in the \L ojasiewicz-Simon approach, but are of local nature.


title: Bounding Betti numbers of bipartite graph ideals

abstract:
  We prove a conjectured lower bound of Nagel and Reiner on Betti numbers of
edge ideals of bipartite graphs.


title:
From major merger to radio galaxy: low surface-brightness stellar
  counterpart to the giant HI ring around B2 0648+27

abstract:
  We present the detection of a low surface-brightness stellar counterpart to
an enormous (190 kpc) ring of neutral hydrogen (HI) gas that surrounds the
nearby radio galaxy B2 0648+27. This system is currently in an evolutionary
stage between major merger and (radio-loud) early-type galaxy. In a previous
paper we investigated in detail the timescales between merger, starburst and
AGN activity in B2 0648+27, based on its unusual multi-wavelength properties
(large-scale HI ring, dominating post-starburst stellar population and
infra-red luminosity). In this Research Note we present deep optical B- and
V-band imaging that provides further evidence for the merger origin of B2
0648+27. The host galaxy shows a distorted optical morphology and a broad tidal
arm is clearly present. A low surface-brightness stellar tail or partial ring
curls around more than half the host galaxy at a distance of up to 55 kpc from
the centre of the galaxy, following the large-scale, ring-like HI structure
that we detected previously around this system. The gas and stars in this ring
are most likely tidally expelled material that slowly fell back onto the host
galaxy after the merger event. There also appear to be sites of star formation
in the HI ring that may have formed within the gaseous tidal debris after the
merger. We argue that the observed properties of the gas and stars in B2
0648+27, as well as the apparent time-delay between the merger and the
starburst event, may be the logical result of a merger between two gas-rich
disk galaxies with a prominent bulge, or of a merger between an elliptical and
a gas-rich spiral galaxy. There also appears to be a significant time-delay
between the merger/starburst event and the current episode of radio-AGN
activity.


title:
Experimental observables near a nematic quantum critical point in the
  pnictide and cuprate superconductors

abstract:
  The newly discovered high temperature superconductor SmFeAs(O1-xFx) shows a
clear nematic transition where the square lattice of Fe ions has a rectangular
distortion. Similar nematic ordering has also been observed in the cuprate
superconductors. We provide a detailed theory of experimental observables near
such a nematic transition: we calculate the scaling of specific heat, local
density of states (LDOS) and NMR relaxation rate 1/T_1T.


title: On the Capacity of MIMO Interference Channels

abstract:
  The capacity region of a multiple-input-multiple-output interference channel
(MIMO IC) where the channel matrices are square and invertible is studied. The
capacity region for strong interference is established where the definition of
strong interference parallels that of scalar channels. Moreover, the sum-rate
capacity for Z interference, noisy interference, and mixed interference is
established. These results generalize known results for the scalar Gaussian IC.


title:
Nonunitary Interaction, Adiabatic Condition, Haag's Theorem and
  Renormalization

abstract:
  Haag's theorem has shown that the transformation between interacting and free
field operators in a reasonable quantum field theory cannot be unitary. Here,
the original requirement of unitarity is revisited from a physical point of
view to show not only that unitarity is not required but indeed not possible.
Electrodynamics is used as an example. In a classical treatment the interaction
cannot be turned on or off adiabatically as energy conservation cannot be
maintained in a physically meaningful way. In a fully second quantized theory
the interaction (or source) term is always present in the equation of motion
even if the system is in the vacuum state. So, the interaction cannot be
physically turned on or off adiabatically or otherwise. Hence, the
transformation V(t) from free fields to interacting fields cannot be
interpreted as an actual time evolution. This makes the unitarity of V(t)quite
unnecessary as the original reason for unitarity was to conserve probability
(or energy) through a time evolution. It is conjectured that the infinite terms
in the scattering matrix that need renormalization appear due to the forcing of
V(t)to be unitary. An alternate approach to scattering of interacting fields is
suggested.


title: Science with the XEUS High Time Resolution Spectrometer

abstract:
  XEUS has been recently selected by ESA for an assessment study. XEUS is a
large mission candidate for the Cosmic Vision program, aiming for a launch date
as early as 2018. XEUS is a follow-on to ESA's Cornerstone X-Ray Spectroscopy
Mission (XMM-Newton). It will be placed in a halo orbit at L2, by a single
Ariane 5 ECA, and comprises two spacecrafts. The Silicon pore optics assembly
of XEUS is contained in the mirror spacecraft while the focal plane instruments
are contained in the detector spacecraft, which is maintained at the focus of
the mirror by formation flying. The main requirements for XEUS are to provide a
focused beam of X-rays with an effective aperture of 5 m^2 at 1 keV, 2 m^2 at 7
keV, a spatial resolution better than 5 arcsec, a spectral resolution ranging
from 2 to 6 eV in the 0.1-8 keV energy band, a total energy bandpass of 0.1-40
keV, ultra-fast timing, and finally polarimetric capabilities. The High Time
Resolution Spectrometer (HTRS) is one of the five focal plane instruments,
which comprises also a wide field imager, a hard X-ray imager, a cryogenic
spectrometer, and a polarimeter. The HTRS is unique in its ability to cope with
extremely high count rates (up to 2 Mcts/s), while providing sub-millisecond
time resolution and good (CCD like) energy resolution. In this paper, we focus
on the specific scientific objectives to be pursued with the HTRS: they are all
centered around the key theme "Matter under extreme conditions" of the Cosmic
Vision science program. We demonstrate the potential of the HTRS observations
to probe strong gravity and matter at supra-nuclear densities. We conclude this
paper by describing the current implementation of the HTRS in the XEUS focal
plane.


title:
Scaling of Saddle-Node Bifurcations: Degeneracies and Rapid Quantitative
  Changes

abstract:
  The scaling of the time delay near a "bottleneck" of a generic saddle-node
bifurcation is well-known to be given by an inverse square-root law. We extend
the analysis to several non-generic cases for smooth vector fields. We proceed
to investigate $C^0$ vector fields. Our main result is a new phenomenon in
two-parameter families having a saddle-node bifurcation upon changing the first
parameter. We find distinct scalings for different values of the second
parameter ranging from power laws with exponents in (0,1) to scalings given by
O(1). We illustrate this rapid quantitative change of the scaling law by a an
overdamped pendulum with varying length.


title:
Testing the Paradigm that Ultraluminous X-ray Sources as a Class
  Represent Accreting Intermediate-Mass Black Holes

abstract:
  To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies
represent a class of accreting intermediate-mass black holes (IMBHs), we have
undertaken a program to identify ULXs and a lower luminosity X-ray comparison
sample with the highest quality data in the {\it Chandra} archive. We establish
as a general property of ULXs that the most X-ray-luminous objects possess the
flattest X-ray spectra (in the {\it Chandra} bandpass). No prior sample studies
have established the general hardening of ULX spectra with luminosity. This
hardening occurs at the highest luminosities (absorbed luminosity
$\geq5\times10^{39}$~erg~s$^{-1}$) and is in line with recent models arguing
that ULXs are actually stellar-mass black holes. From spectral modeling, we
show that the evidence originally taken to mean that ULXs are IMBHs - i.e., the
"simple IMBH model" - is nowhere near as compelling when a large sample of ULXs
is looked at properly. During the last couple of years, {\it XMM-Newton}
spectroscopy of ULXs has to a large extent begun to negate the simple IMBH
model based on fewer objects. We confirm and expand these results, which
validates the {\it XMM-Newton} work in a broader sense with independent X-ray
data. We find that (1) cool-disk components are present with roughly equal
probability and total flux fraction for any given ULX, regardless of
luminosity, and (2) cool-disk components extend below the standard ULX
luminosity cutoff of 10$^{39}$~erg~s$^{-1}$, down to our sample limit of
10$^{38.3}$~erg~s$^{-1}$. The fact that cool disk components are not correlated
with luminosity damages the argument that cool disks indicate IMBHs in ULXs,
for which strong statistical support was never found.


title: SPIDER: A Balloon-borne Large-scale CMB Polarimeter

abstract:
  Spider is a balloon-borne experiment that will measure the polarization of
the Cosmic Microwave Background over a large fraction of a sky at 1 degree
resolution. Six monochromatic refracting millimeter-wave telescopes with large
arrays of antenna-coupled transition-edge superconducting bolometers will
provide system sensitivities of 4.2 and 3.1 micro K_cmb rt s at 100 and 150
GHz, respectively. A rotating half-wave plate will modulate the polarization
sensitivity of each telescope, controlling systematics. Bolometer arrays
operating at 225 GHz and 275 GHz will allow removal of polarized galactic
foregrounds. In a 2-6 day first flight from Alice Springs, Australia in 2010,
Spider will map 50% of the sky to a depth necessary to improve our knowledge of
the reionization optical depth by a large factor.


title: Iterated Point-Line Configurations Grow Doubly-Exponentially

abstract:
  Begin with a set of four points in the real plane in general position. Add to
this collection the intersection of all lines through pairs of these points.
Iterate. Ismailescu and Radoi\v{c}i\'{c} (2003) showed that the limiting set is
dense in the plane. We give doubly exponential upper and lower bounds on the
number of points at each stage. The proof employs a variant of the
Szemer\'edi-Trotter Theorem and an analysis of the ``minimum degree'' of the
growing configuration.


title: Discernment of Hubs and Clusters in Socioeconomic Networks

abstract:
  Interest in the analysis of networks has grown rapidly in the new millennium.
Consequently, we promote renewed attention to a certain methodological approach
introduced in 1974. Over the succeeding decade, this
two-stage--double-standardization and hierarchical clustering
(single-linkage-like)--procedure was applied to a wide variety of weighted,
directed networks of a socioeconomic nature, frequently revealing the presence
of ``hubs''. These were, typically--in the numerous instances studied of
migration flows between geographic subdivisions within
nations--``cosmopolitan/non-provincial'' areas, a prototypical example being
the French capital, Paris. Such locations emit and absorb people broadly across
their respective nations. Additionally, the two-stage procedure--which ``might
very well be the most successful application of cluster analysis'' (R. C.
Dubes, 1985)--detected many (physically or socially) isolated, functional
groups (regions) of areas, such as the southern islands, Shikoku and Kyushu, of
Japan, the Italian islands of Sardinia and Sicily, and the New England region
of the United States. Further, we discuss a (complementary) approach developed
in 1976, in which the max-flow/min-cut theorem was applied to
raw/non-standardized (interindustry, as well as migration) flows.

categories: physics.soc-ph cs.SI physics.data-an stat.AP


title: Sequential cavity method for computing free energy and surface pressure

abstract:
  We propose a new method for the problems of computing free energy and surface
pressure for various statistical mechanics models on a lattice $\Z^d$. Our
method is based on representing the free energy and surface pressure in terms
of certain marginal probabilities in a suitably modified sublattice of $\Z^d$.
Then recent deterministic algorithms for computing marginal probabilities are
used to obtain numerical estimates of the quantities of interest. The method
works under the assumption of Strong Spatial Mixing (SSP), which is a form of a
correlation decay.
  We illustrate our method for the hard-core and monomer-dimer models, and
improve several earlier estimates. For example we show that the exponent of the
monomer-dimer coverings of $\Z^3$ belongs to the interval $[0.78595,0.78599]$,
improving best previously known estimate of (approximately) $[0.7850,0.7862]$
obtained in \cite{FriedlandPeled},\cite{FriedlandKropLundowMarkstrom}.
Moreover, we show that given a target additive error $\epsilon>0$, the
computational effort of our method for these two models is
$(1/\epsilon)^{O(1)}$ \emph{both} for free energy and surface pressure. In
contrast, prior methods, such as transfer matrix method, require
$\exp\big((1/\epsilon)^{O(1)}\big)$ computation effort.


title: Gradings on the Kac superalgebra

abstract: We classify the gradings on the Kac superalgebra up to equivalence.


title: Dielectric Screening in a Spherical Cavity

abstract:
  In this work we examine the electrostatic screening potential due to a point
charge located off-centre in a spherical dielectric cavity. This potential is
expanded for the case in which the dielectric constant $\epsilon$ is large,
several methods of finding the terms in the expansion are investigated, and
closed-form expressions are found through third order in $\epsilon$ along with
error bounds. Finally, possible uses of these expressions in molecular dynamics
simulations of isolated charged molecules is discussed.


title: Magneto-conductance Oscillations in Graphene Antidot Arrays

abstract:
  Epitaxial graphene films have been formed on the C-face of semi-insulating
4H-SiC substrates by a high temperature sublimation process. Nano-scale square
antidot arrays have been fabricated on these graphene films. At low
temperatures, magneto-conductance in these films exhibits pronounced
Aharonov-Bohm oscillations with the period corresponding to magnetic flux
quanta added to the area of a single antidot. At low fields, weak localization
is observed and its visibility is enhanced by intravalley scattering on antidot
edges. At high fields, we observe two distinctive minima in magnetoconductance
which can be attributed to commensurability oscillations between classical
cyclotron orbits and antidot array. All mesoscopic features, surviving up to 70
K, reveal the unique electronic properties of graphene.


title: High temperature ferromagnetism in Co-implanted TiO2 rutile

abstract:
  We report on structural, magnetic and electronic properties of Co-implanted
TiO2 rutile single crystals for different implantation doses. Strong
ferromagnetism at room temperature and above is observed in TiO2 rutile plates
after cobalt ion implantation, with magnetic parameters depending on the cobalt
implantation dose. While the structural data indicate the presence of metallic
cobalt clusters, the multiplet structure of the Co L3 edge in the XAS spectra
gives clear evidence for a substitutional Co 2+ state. The detailed analysis of
the structural and magnetic properties indicates that there are two magnetic
phases in Co-implanted TiO2 plates. One is a ferromagnetic phase due to the
formation of long range ferromagnetic ordering between implanted magnetic
cobalt ions in the rutile phase, and the second one is a superparamagnetic
phase originates from the formation of metallic cobalt clusters in the
implanted region. Using x-ray resonant magnetic scattering, the element
specific magnetization of cobalt, oxygen and titanium in Co-implanted TiO2
single crystals are investigated. Magnetic dichroism was observed at the Co L
edges as well as at the O K edge. The interaction mechanism, which leads to
ferromagnetic ordering of substituted cobalt ions in the host matrix, is also
discussed.


title: DIS and the effects of fluctuations: a momentum space analysis

abstract:
  Among the dipole models of deep inelastic scattering at small values of the
Bjorken variable $x$, one has been recently proposed which relates the virtual
photon-proton cross section to the dipole-proton forward scattering amplitude
in momentum space. The latter is parametrized by an expression which
interpolates between its behavior at saturation and the travelling wave,
ultraviolet, amplitudes predicted by perturbative QCD from the
Balitsky-Kovchegov equation. Inspired by recent developments in coordinate
space, we use this model to parametrize the proton structure function and
confront it to HERA data on $ep$ deep inelastic scattering. Both event-by-event
and the physical amplitudes are considered, the latter used to investigate the
effect of gluon number fluctuations, beyond the mean-field approximation. We
conclude that fluctuations are not present in DIS at HERA energies.


title: Some Ramsey results for the n-cube

abstract:
  In this note we establish a Ramsey-type result for certain subsets of the
$n$-dimensional cube. This can then be applied to obtain reasonable bounds on
various related structures, such as (partial) Hales-Jewett lines for alphabets
of sized 3 and 4, Hilbert cubes in sets of real numbers with small sumsets,
"corner" in the integer lattice in the plane, and 3-term geometric progressions
in integers.


title: Cyclooxygenase inhibition in ischemic brain injury

abstract:
  Neuroinflammation is one of the key pathological events involved in the
progression of brain damage caused by cerebral ischemia. Metabolism of
arachidonic acid through cyclooxygenase (COX) enzymes is known to be actively
involved in the neuroinflammatory events leading to neuronal death after
ischemia. Two isoforms of COX, termed COX-1 and COX-2, have been identified.
Unlike COX-1, COX-2 expression is dramatically induced by ischemia and appears
to be an effector of tissue damage. This review article will focus specifically
on the involvement of COX isozymes in brain ischemia. We will discuss issues
related to the biochemistry and selective pharmacological inhibition of COX
enzymes, and further refer to their expression in the brain under normal
conditions and following excitotoxicity and ischemic cerebral injury. We will
review present knowledge of the relative contribution of each COX isoform to
the brain ischemic pathology, based on data from investigations utilizing
selective COX-1/COX-2 inhibitors and genetic knockout mouse models. The
mechanisms of neurotoxicity associated with increased COX activity after
ischemia will also be examined. Finally, we will provide a critical evaluation
of the therapeutic potential of COX inhibitors in cerebral ischemia and discuss
new targets downstream of COX with potential neuroprotective ability.


title: Neutrino Mass and Neutrinoless Double Beta Decay

abstract:
  The motivation for the search for $0\nu\beta\beta$ decay is briefly reviewed.
It is stressed that the exchange of light Majorana neutrinos is not the only
possible mechanism of the decay. The link between lepton number and lepton
flavor violation is described and its role in elucidating the
$0\nu\beta\beta$-decay mechanism is discussed. The main topic of the talk is
the evaluation of the nuclear matrix elements and their uncertainty. Various
physics effects that influence the value of the matrix elements are described
and the results of the two main methods, the quasiparticle random phase
approximation and the nuclear shell model, are compared.


title: Scientific Paper Summarization Using Citation Summary Networks

abstract:
  Quickly moving to a new area of research is painful for researchers due to
the vast amount of scientific literature in each field of study. One possible
way to overcome this problem is to summarize a scientific topic. In this paper,
we propose a model of summarizing a single article, which can be further used
to summarize an entire topic. Our model is based on analyzing others' viewpoint
of the target article's contributions and the study of its citation summary
network using a clustering approach.


title:
Reflected light from 3D exoplanetary atmospheres and simulation of HD
  209458b

abstract:
  We present radiation transfer models that demonstrate that reflected light
levels from three dimensional (3D) exoplanetary atmospheres can be more than
50% lower than those predicted by models of homogeneous or smooth atmospheres.
Compared to smooth models, 3D atmospheres enable starlight to penetrate to
larger depths resulting in a decreased probability for the photons to scatter
back out of the atmosphere before being absorbed. The increased depth of
penetration of starlight in a 3D medium is a well known result from theoretical
studies of molecular clouds and planetary atmospheres. For the first time we
study the reflectivity of 3D atmospheres as a possible explanation for the
apparent low geometric albedos inferred for extrasolar planetary atmospheres.
Our models indicate that 3D atmospheric structure may be an important
contributing factor to the non-detections of scattered light from exoplanetary
atmospheres. We investigate the self-shadowing radiation transfer effects of
patchy cloud cover in 3D scattered light simulations of the atmosphere of
HD209458b. We find that, for a generic planet, geometric albedos can be as high
as 0.45 in some limited situations, but that in general the geometric albedo is
much lower. We conclude with some explanations on why extrasolar planets are
likely dark at optical wavelengths.


title: Applied Symbolic Vector Dynamics of Coupled Map Lattice

abstract:
  Symbolic dynamics, which partitions an infinite number of finite-length
trajectories into a finite number of trajectory sets, describes the dynamics of
a system in a simplified and coarse-grained way with a limited number of
symbols. The study of symbolic dynamics in 1D chaotic map has been further
developed and is named as the applied symbolic dynamics. In this paper, we will
study the applied symbolic vector dynamics of CML. Based on the original
contribution proposed in Refs.[6], we will study the ergodic property of CML.
We will analyze the relation between admissibility condition and control
parameters, and then give a coupling coefficient estimation method based on the
ergodic property. Both theoretical and experimental results show that we
provide a natural analytical technique for understanding turbulences in CML.
Many of our findings could be expanded to a wider range of application.


title:
Spontaneous symmetry breaking and finite time singularities in
  $d$-dimensional incompressible flow with fractional dissipation

abstract:
  We investigate the formation of singularities in the incompressible
Navier-Stokes equations in $d\geq 2$ dimensions with a fractional Laplacian
$|\nabla |^\alpha$. We derive analytically a sufficient but not necessary
condition for solutions to remain always smooth and show that finite time
singularities cannot form for $\alpha\geq \alpha_c= 1+d/2$. Moreover, initial
singularities become unstable for $\alpha>\alpha_c$.


title: Charged Black Holes in a Rotating Gross-Perry-Sorkin Monopole Background

abstract:
  We present a new class of stationary charged black hole solutions to
five-dimensional Einstein-Maxwell-Chern-Simons theories. We construct the
solutions by utilizing so called the squashing transformation. At infinity, our
solutions behave as a four-dimensional flat spacetime plus a `circle' and hence
describe a Kaluza-Klein black hole. More precisely, our solutions can be viewed
as a charged rotating black hole in a rotating Gross-Perry-Sorkin monopole
background with the black hole rotation induced from the background rotation.


title: Galaxy Clusters in the IRAC Dark Field I: Growth of the red sequence

abstract:
  Using three newly identified galaxy clusters at z~1 (photometric redshift) we
measure the evolution of the galaxies within clusters from high redshift to the
present day by studying the growth of the red cluster sequence. The clusters
are located in the Spitzer Infrared Array Camera (IRAC) Dark Field, an
extremely deep mid-infrared survey near the north ecliptic pole with photometry
in 18 total bands from X-ray through far-IR. Two of the candidate clusters are
additionally detected as extended emission in matching Chandra data in the
survey area allowing us to measure their masses to be M_{500}= 6.2 \pm 1.0
\times 10^{13} and 3.6 \pm 1.1 \times 10^{13} solar masses. For all three
clusters we create a composite color magnitude diagram in rest-frame B-K using
our deep HST and Spitzer imaging. By comparing the fraction of low luminosity
member galaxies on the composite red sequence with the corresponding population
in local clusters at z=0.1 taken from the COSMOS survey, we examine the effect
of a galaxy's mass on its evolution. We find a deficit of faint galaxies on the
red sequence in our z~1 clusters which implies that more massive galaxies have
evolved in clusters faster than less massive galaxies, and that the less
massive galaxies are still forming stars in clusters such that they have not
yet settled onto the red sequence.


title:
Self-Spin-Controlled Rotation of Spatial States of a Dirac Electron in a
  Cylindrical Potential via Spin-Orbit Interaction

abstract:
  Solution of the Dirac equation predicts that when an electron with non-zero
orbital angular momentum propagates in a cylindrically symmetric potential, its
spin and orbital degrees of freedom interact, causing the electron's phase
velocity to depend on whether its spin and orbital angular momenta vectors are
oriented parallel or anti-parallel with respect to each other. This spin-orbit
splitting of the electronic dispersion curves can result in a rotation of the
electron's spatial state in a manner controlled by the electron's own spin
z-component value. These effects persist at non-relativistic velocities. To
clarify the physical origin of this effect, we compare solutions of the Dirac
equation to perturbative predictions of the Schrodinger-Pauli equation with a
spin-orbit term, using the standard Foldy-Wouthuysen Hamiltonian. This clearly
shows that the origin of the effect is the familiar relativistic spin-orbit
interaction.


title: N-vaton

abstract:
  In general there are a large number of light scalar fields in the theories
going beyond standard model, such as string theory, and some of them can be
taken as the candidates of curvatons. For simplicity, we assume all of
curvatons have the same decay rate and suddenly decay into radiation at the
same time. In order to distinguish this scenario from the more general case, we
call it "N-vaton". We use $\delta {\cal N}$ formalism to calculate the
primordial power spectrum and bispectrum in N-vaton model and investigate
various bounds on the non-Gaussianity parameter $f_{NL}$. A red tilted
primordial power spectrum and a large value of $f_{NL}$ can be naturally
obtained if the curvature perturbation generated by inflaton also makes a
significant contribution to the primordial power spectrum. As a realistic
N-vaton model, we suppose that the axions in the KKLT compactifications of Type
IIB string theory are taken as curvatons and a rich phenomenology is obtained.


title: Heralded quantum memory for single-photon polarization qubits

abstract:
  We propose a scheme to implement a heralded quantum memory for single-photon
polarization qubits with a single atom trapped in an optical cavity. In this
scheme, an injected photon only exchanges quantum state with the atom, so that
the heralded storage can be achieved by detecting the output photon. We also
demonstrate that the scheme can be used for realizing the heralded quantum
state transfer, exchange and entanglement distribution between distant nodes.
The ability to detect whether the operation has succeeded or not is crucial for
practical application.


title: Intermediate Scale Inflation and Metastable Supersymmetry Breaking

abstract:
  We investigate the possibility of obtaining a low scale of supersymmetry
breaking within the ISS framework using a metastable vacuum. This is achieved
by introducing an R-symmetry preserving gravitational coupling of the ISS
sector to a relatively low scale inflationary sector. We find the allowed range
for the supersymmetry breaking scale, 10^4 GeV < \mu < 10^8 GeV, which is low
enough to be amenable to gauge supersymmetry breaking mediation. This scenario
is based upon a so-called hilltop inflation phase whose initial condition
problem is also addressed.


title:
Relaxed Three-Algebras: Their Matrix Representations and Implications
  for Multi M2-brane Theory

abstract:
  We argue that one can relax the requirements of the non-associative
three-algebras recently used in constructing D=3, N=8 superconformal field
theories, and introduce the notion of ``relaxed three-algebras''. We present a
specific realization of the relaxed three-algebras in terms of classical Lie
algebras with a matrix representation, endowed with a non-associative
four-bracket structure which is prescribed to replace the three-brackets of the
three-algebras. We show that both the so(4)-based solutions as well as the
cases with non-positive definite metric find a uniform description in our
setting. We discuss the implications of our four-bracket representation for the
D=3, N=8 and multi M2-brane theory and show that our setup can shed light on
the problem of negative kinetic energy degrees of freedom of the Lorentzian
case.


title:
Dimensional crossover in a spin liquid to helimagnet quantum phase
  transition

abstract:
  Neutron scattering is used to study magnetic field induced ordering in the
quasi-1D quantum spin-tube compound Sul--Cu$_2$Cl$_4$ that in zero field has a
non-magnetic spin-liquid ground state. The experiments reveal an incommensurate
chiral high-field phase stabilized by a geometric frustration of the magnetic
interactions. The measured critical exponents $\beta\approx0.235$ and
$\nu\approx0.34$ at $H_c\approx3.7$ T point to an unusual sub-critical scaling
regime and may reflect the chiral nature of the quantum critical point.


title: Decoherence of two qubits in a non-Markovian squeezed reservoir

abstract:
  The decoherence of two initially entangled qubits in a squeezed vacuum cavity
has been investigated exactly. The results show that, first, in principle, the
disentanglement time decreases with the increasing of squeeze parameter r, due
to the augmenting of average photon number of every mode in squeezed vacuum
cavity. Second, there are entanglement revivals after complete disentanglement
for the case of even parity initial Bell state, while there are entanglement
decrease and revival before complete disentanglement for the case of odd parity
initial Bell state. The results are quite different from that of the case for
qubits in a vacuum cavity.


title:
Joint Temporal Density Measurements for Two-Photon State
  Characterization

abstract:
  We demonstrate a new technique for characterizing two-photon quantum states
based on joint temporal correlation measurements using time resolved single
photon detection by femtosecond upconversion. We measure for the first time the
joint temporal density of a two-photon entangled state, showing clearly the
time anti-correlation of the coincident-frequency entangled photon pair
generated by ultrafast spontaneous parametric down-conversion under extended
phase-matching conditions. The new technique enables us to manipulate the
frequency entanglement by varying the down-conversion pump bandwidth to produce
a nearly unentangled two-photon state that is expected to yield a heralded
single-photon state with a purity of 0.88. The time-domain correlation
technique complements existing frequency-domain measurement methods for a more
complete characterization of photonic entanglement in quantum information
processing.


title:
Large-Sample Confidence Intervals for the Treatment Difference in a
  Two-Period Crossover Trial, Utilizing Prior Information

abstract:
  Consider a two-treatment, two-period crossover trial, with responses that are
continuous random variables. We find a large-sample frequentist 1-alpha
confidence interval for the treatment difference that utilizes the uncertain
prior information that there is no differential carryover effect.


title:
Ionic environment control of visible photo-luminescence from ZnO
  nanoparticles

abstract:
  We report a novel effect that the visible photoluminescence (in the
blue-green band) from ZnO anoparticles can be controlled by changing the ionic
or polar nature of the medium in which the nanoparticles are dispersed. We find
that the presence of sufficient amount of electrolytes can even quench the
emission. We propose an explanation based on surface charge of the ZnO
nanoparticles which control the band bending in the depletion layer at the
surface of the anoparticles. The band bending in turn, decides the predominant
nature of the visible emission. The explanation is validated by establishing a
direct correlation between the visible emission and the zeta potential.


title: Pseudorandom Number Generators and the Square Site Percolation Threshold

abstract:
  A select collection of pseudorandom number generators is applied to a Monte
Carlo study of the two dimensional square site percolation model. A generator
suitable for high precision calculations is identified from an application
specific test of randomness. After extended computation and analysis, an
ostensibly reliable value of pc = 0.59274598(4) is obtained for the percolation
threshold.


title:
Experimental Investigation of Thickness Effects on Mixed-mode I/II
  Fracture of an Aluminum Alloy

abstract:
  Experimental investigations on the effect of thicknesses on mixed-mode I/II
fracture are performed with an aluminum alloy with thicknesses of 2, 4, 8 and
14 mm. It is found that under pure-mode I loading condition, the loading
capacity per unit thickness monotonically decreases with increasing thickness.
However, under mixed-mode loading condition, the dependence of loading capacity
on the thickness becomes very weak. Although the measured crack initiation
angles from the mid-plane of the fractured specimens coincide well with typical
existed criteria in the thin and thick specimens under all the mixed-mode
conditions except pure-mode II, exceptional low crack initiation angles are
found in the 8mm-thick specimens. Although ductile dimples are the dominated
microscopic features in all the specimens, the size of the final voids varies
significantly with specimen thickness and loading mode. The ductile dimples in
the crack initiation zone become larger and shallower as the specimen thickness
decreasing.


title: Disorder-induced enhancement of transport through graphene p-n junctions

abstract:
  We investigate the electron transport through a graphene p-n junction under a
perpendicular magnetic field. By using Landauar-Buttiker formalism combining
with the non-equilibrium Green function method, the conductance is studied for
the clean and disordered samples. For the clean p-n junction, the conductance
is quite small. In the presence of disorders, it is strongly enhanced and
exhibits plateau structure at suitable range of disorders. Our numerical
results show that the lowest plateau can survive for a very broad range of
disorder strength, but the existence of high plateaus depends on system
parameters and sometimes can not be formed at all. When the disorder is
slightly outside of this disorder range, some conductance plateaus can still
emerge with its value lower than the ideal value. These results are in
excellent agreement with the recent experiment.


title: A splitting theorem for equifocal submanifolds with non-flat section

abstract:
  In this paper, I prove a splitting theorem for equifocal submanifolds with
non-flat section in a simply connected symmetric space of compact type. Also,
by using the splitting theorem, I prove that the sections of equifocal
submanifolds with non-flat section in an irreducible simply connected symmetric
space of compact type are isometric to a sphere or a real projective space.


title:
Spin squeezing in a bimodal condensate: spatial dynamics and particle
  losses

abstract:
  We propose an analytical method to study the entangled spatial and spin
dynamics of interacting bimodal Bose-Einstein condensates. We show that at
particular times during the evolution spatial and spin dynamics disentangle and
the spin squeezing can be predicted by a simple two-mode model. We calculate
the maximum spin squeezing achievable in experimentally relevant situations
with Sodium or Rubidium bimodal condensates, including the effect of the
dynamics and of one, two and three-body losses.


title: On the Completeness of Gradient Ricci Solitons

abstract:
  A gradient Ricci soliton is a triple $(M,g,f)$ satisfying
$R_{ij}+\nabla_i\nabla_j f=\lambda g_{ij}$ for some real number $\lambda$. In
this paper, we will show that the completeness of the metric $g$ implies that
of the vector field $\nabla f$.


title: Gradient Shrinking Solitons with Vanishing Weyl Tensor

abstract:
  In this paper, we will give a local version of the Hamilton-Ivey type
pinching estimate of the gradient shrinking soliton with vanishing Weyl tensor,
and then give a complete classification on gradient shrinking solitons with
vanishing Weyl tensor.


title: Lie properties of crossed products

abstract:
  Let $F^\lambda_{\sigma} [G]$ be a crossed product of a group $G$ and the
field $F$. We study the Lie properties of $F^\lambda_{\sigma} [G]$ in order to
obtain a characterization of those crossed products which are upper (lower) Lie
nilpotent and Lie $(n,m)$-Engel.


title:
Coupling superconducting flux qubits at optimal point via dynamic
  decoupling with the quantum bus

abstract:
  We propose a scheme with dc-control of finite bandwidth to implement
two-qubit gate for superconducting flux qubits at the optimal point. We provide
a detailed non-perturbative analysis on the dynamic evolution of the qubits
interacting with a common quantum bus. An effective qubit-qubit coupling is
induced while decoupling the quantum bus with proposed pulse sequences. The
two-qubit gate is insensitive to the initial state of the quantum bus and
applicable to non-perturbative coupling regime which enables rapid two-qubit
operation. This scheme can be scaled up to multi-qubit coupling.


title: Multiplicative Noise Induces Zero Critical Frequency

abstract:
  Stochastic Bloch equations which model the fluorescence of two level
molecules and atoms, NMR experiments and Josephson junctions are investigated
to illustrate the profound effect of multiplicative noise on the critical
frequency of a dynamical system. Using exact solutions and the cumulant
expansion we find two main effects: (i) even very weak noise may double or
triple the number of critical frequencies, which is related to an instability
of the system and (ii) strong multiplicative noise may induce a non-trivial
zero critical frequency thus wiping out the over-damped phase.


title: Counterion-mediated Electrostatic Interactions between Helical Molecules

abstract:
  We study the interaction of two cylinders with helical charge distribution
mediated by neutralizing counterions, by analyzing the separation as well as
the azimuthal angle dependence of the interaction force in the weak and strong
coupling limit. While the azimuthal dependence of the interaction in the weak
coupling limit is overall small and mostly negligible, the strong coupling
limit leads to qualitatively new features of the interaction, among others also
to an orientationally dependent optimal configuration that is driven by angular
dependence of the correlation attraction. We investigate the properties of this
azimuthal ordering in detail and compare it to existing results.


title:
Deep inelastic scattering and prompt photon production within the
  framework of quark Reggeization hypothesis

abstract:
  We study ep deep inelastic scattering and the inclusive production of prompt
photon within the framework of the quasi-multi-Regge-kinematic approach,
applying the quark Reggeization hypothesis. We describe structure functions F_2
and F_L supposing that a virtual photon scatters on a Reggeized quark from a
proton, via the effective gamma-Reggeon-quark vertex. It is shown that the main
mechanism of the inclusive prompt photon production in p \bar p collisions is
the fusion of a Reggeized quark and a Reggeized antiquark into a photon, via
the effective Regeon-Reggeon-gamma vertex. We describe the inclusive photon
transverse momentum spectra measured by the CDF and D0 Collaborations within
errors and without free parameters, using the Kimber-Martin-Ryskin unintegrated
quark and gluon distribution functions in a proton.


title:
Cross section of the processes $e^++e^-\to e^++e^-(\gamma)$, $\to
  \pi^++\pi^-(\gamma)$, $ \mu^++\mu^-(\gamma)$, $ \gamma+\gamma(\gamma)$ in the
  energy region 200 MeV $\le 2E\le$ 3 GeV

abstract:
  The cross section for different processes induced by $e^+e^-$ annihilation,
in the kinematical limit
$\beta_{\mu}\approx\beta_{\pi}=(1-m_{\pi}^2/\epsilon^2)^{1/2}\sim 1$, is
calculated taking into account first order corrections to the amplitudes and
the corrections due to soft emitted photons, with energy $\omega\le\Delta E\le
\epsilon$ in the center of mass of the $e^+e^-$ colliding beams. The results
are given separately for charge--odd and charge--even terms in the final
channels $\pi^+\pi^-(\gamma)$ and $\mu^+\mu^-(\gamma)$. In case of pions, form
factors are taken into account. The differential cross sections for the
processes: $e^++e^-\to e^++e^-(+\gamma)$, $\to \pi^++\pi^-(\gamma)$, $\to
\mu^++\mu^-(\gamma),\to \gamma\gamma(\gamma)$ have been calculated and the
corresponding formula are given in the ultrarelativistic limit $\sqrt{s}/2=
\epsilon \gg m_{\mu}\sim m_{\pi}$ . For a quantitative evaluation of the
contribution of higher order of the perturbation theory, the production of
$\pi^+\pi^-$, including radiative corrections, is calculated in the approach of
the lepton structure functions. This allows to estimate the precision of the
obtained results as better than 0.5% outside the energy region corresponding to
narrow resonances. A method to integrate the cross section, avoiding the
difficulties which arise from singularities is also described.


title:
Rotor in a Cage: Infrared Spectroscopy of an Endohedral
  Hydrogen-Fullerene Complex

abstract:
  We report the observation of quantized translational and rotational motion of
molecular hydrogen inside the cages of C60. Narrow infrared absorption lines at
the temperature of 6K correspond to vibrational excitations in combination with
translational and rotational excitations and show well resolved splittings due
to the coupling between translational and rotational modes of the endohedral H2
molecule. A theoretical model shows that H2 inside C60 is a three-dimensional
quantum rotor moving in a nearly spherical potential. The theory provides both
the frequencies and the intensities of the observed infrared transitions. Good
agreement with the experimental results is obtained by fitting a small number
of empirical parameters to describe the confining potential, as well as the
ortho to para ratio.


title:
Nonequilibrium carriers in an intrinsic graphene under interband
  photoexcitation

abstract:
  We study nonequilibrium carriers (electrons and holes) in an intrinsic
graphene at low temperatures under far- and mid-infrared (IR) radiation in a
wide range of its intensities. The energy distributions of carriers are
calculated using a quasiclassic kinetic equation which accounts for the energy
relaxation due to acoustic phonons and the radiative generation-recombination
processes associated with thermal radiation and the carrier photoexcitation by
incident radiation. It is found that the nonequilibrium distributions are
determined by an interplay between weak energy relaxation on acoustic phonons
and generation-recombination processes as well as by the effect of pumping
saturation. Due to the effect of saturation, the carrier distribution functions
can exhibit plateaus around the pumping region at elevated intensities. As
shown, at sufficiently strong mid-IR pumping, the population inversion can
occur below the pumping energy. The graphene dc conductivity as a function of
the pumping intensity exhibits a pronounced nonlinearity with a sub-linear
region at fairly low intensities and a saturation at a strong pumping. However,
an increase in the pumping intensity in very wide range leads only to a modest
increase in the carrier concentration and, particularly, the dc conductivity.
The graphene conductivity at mid-IR irradiation exhibit strong sensitivity to
mechanisms of carrier momentum relaxation.


title:
Unveiling a Compact Cluster of Massive and Young Stars in IRAS
  17233-3606

abstract:
  We have analyzed sensitive high spatial resolution archival radio continuum
data at 1.3, 2.0, 3.6 and 6.0 cm as well as the H2O maser molecular line data
obtained using the Very Large Array (VLA) in its hybrid AB configuration toward
the high-mass star-forming region IRAS 17233-3606 (G351.78-0.54). We find nine
compact radio sources associated with this region, six of them are new radio
detections. We discuss the characteristics of these sources based mostly on
their spectral indices and find that most of them appear to be optically thin
or thick ultra- and hyper-compact HII regions ionized by B ZAMS stars.
Furthermore, in a few cases the radio emission may arise from optically thick
dusty disks and/or cores, however more observations at different wavelengths
are necessity to firmly confirm their true nature. In addition, we compared our
centimeter maps with the mid-infrared images fromthe Spitzer Space Observatory
GLIMPSE survey revealing a cluster of young protostars in the region together
with multiple collimated outflows some of whom might be related with the
compact centimeter objects.


title:
Uniqueness of signed measures solving the continuity equation for Osgood
  vector fields

abstract:
  Nonnegative measure-valued solutions of the continuity equation are uniquely
determined by their initial condition, if the characteristic ODE associated to
the velocity field has a unique solution. In this paper we give a partial
extension of this result to signed measure-valued solutions, under a
quantitative two-sided Osgood condition on the velocity field. Our results
extend those obtained for log-Lipschitz vector fields by Bahouri and Chemin.


title: On the Conley decomposition of Mather sets

abstract:
  In the context of Mather's theory of Lagrangian systems, we study the
decomposition in chain-transitive classes of the Mather invariant sets. As an
application, we prove, under appropriate hypotheses, the semi-continuity of the
so-called Aubry set as a function of the Lagrangian.


title: Evolution Families and the Loewner Equation I: The Unit Disc

abstract:
  In this paper we introduce a general version of the Loewner differential
equation which allows us to present a new and unified treatment of both the
radial equation introduced in 1923 by K. Loewner and the chordal equation
introduced in 2000 by O. Schramm. In particular, we prove that evolution
families in the unit disc are in one to one correspondence with solutions to
this new type of Loewner equations. Also, we give a Berkson-Porta type formula
for non-autonomous weak holomorphic vector fields which generate such Loewner
differential equations and study in detail geometric and dynamical properties
of evolution families.


title:
The homogeneous slice theorem for the complete complexification of a
  proper complex equifocal submanifold

abstract:
  We investigate the homogeneity of certain kind of slices of the complete
complexification of a proper complex equifocal submanifold in a symmetric space
of non-compact type.


title: Hamiltonian Systems: Stability and Instability Theory

abstract:
  This is a short survey on Nekhoroshev theory, KAM theory, and Arnold's
diffusion.


title: Stochastic quantization at finite chemical potential

abstract:
  A nonperturbative lattice study of QCD at finite chemical potential is
complicated due to the complex fermion determinant and the sign problem. Here
we apply the method of stochastic quantization and complex Langevin dynamics to
this problem. We present results for U(1) and SU(3) one link models and QCD at
finite chemical potential using the hopping expansion. The phase of the
determinant is studied in detail. Even in the region where the sign problem is
severe, we find excellent agreement between the Langevin results and exact
expressions, if available. We give a partial understanding of this in terms of
classical flow diagrams and eigenvalues of the Fokker-Planck equation.


title: A generic property of families of Lagrangian systems

abstract:
  We prove that a generic lagrangian has finitely many minimizing measures for
every cohomology class.


title: Study of the decay Ds+ --> K+ K- e+ nu

abstract:
  Using 214 fb-1 of data recorded by the Babar detector at the PEPII
electron-positron collider, we study the decay Ds+ --> K+ K- e+ nu. Except for
a small S-wave contribution, the events with K+K- masses in the range 1.01-1.03
GeV/c2 correspond to phi mesons. For Ds+ --> phi e+ nu decays, we measure the
relative normalization of the Lorentz invariant form factors at q2=0,
rV=V(0)/A1(0)=1.849 +/- 0.060 +/- 0.095, r2=A2(0)/A1(0)=0.763 +/- 0.071 +/-
0.065 and the pol e mass of the axial-vector form factors
mA=(2.28^{+0.23}_{-0.18}+/- 0.18) GeV/c2. Within the same K+K- mass range, we
also measure the relative branching fraction B(Ds+ --> K + K- e+ nu)/B(Ds+ -->
K+ K- pi+)=0.558 +/- 0.007 +/- 0.016, from which we obtain the total branching
fraction B(Ds+ --> phi e+ nu) = (2.61 +/- 0.03 +/- 0.08 +/- 0.15)* 10^{-2}. By
comparing this value with the predicted decay rate, we extract A1(0) = 0.607
+/- 0.011 +/- 0.019 +/- 0.018. The stated uncertainties are statistical,
systematic, and from external inputs.


title: Perturbation d'un hamiltonien partiellement hyperbolique

abstract:
  Arnold's diffusion in quasi integrable hamiltonian systems occurs in
exponentially large time. We study an initially hyperbolic system which admits
diffusion in polynomial time.


title:
The complexifications of pseudo-Riemannian manifolds and anti-Kaehler
  geometry

abstract:
  In this paper, we first define the complexification of a real analytic map
between real analytic Koszul manifolds and show that the complexified map is
the holomorphic extension of the original map. Next we define an anti-Kaehler
metric compatible with the adapted complex structure on the complexification of
a real analytic pseudo-Riemannian manifold. In particular, for a
pseudo-Riemannian homogeneous space, we define another complexification and a
(complete) anti-Kaehler metric on the complexification. One of main purposes of
this paper is to find the interesting relation between these two
complexifications (equipped with the anti-Kaehler metrics) of a
pseudo-Riemannian homogeneous space. Another of main purposes of this paper is
to show that almost all principal orbits of some isometric action on the first
complexification (equipped with the anti-Kaehler metric) of a semi-simple
pseudo-Riemannian symmetric space are curvature-adapted isoparametric
submanifolds with flat section in the sense of this paper.


title: Quantum instability and edge entanglement in a quasi-long-range order

abstract:
  We investigate the build-up of quasi-long-range order in the XX chain with
transverse magnetic field at finite size. As the field is varied, the ground
state of the system displays multiple level crossings producing a sequence of
entanglement jumps. Using the partial fidelity and susceptibility, we study the
transition to the thermodynamic limit and argue that the topological order can
be described in terms of kink-antikink pairs and marked by edge spin
entanglement.


title: A Radar for the Internet

abstract:
  In contrast with most internet topology measurement research, our concern
here is not to obtain a map as complete and precise as possible of the whole
internet. Instead, we claim that each machine's view of this topology, which we
call ego-centered view, is an object worth of study in itself. We design and
implement an ego-centered measurement tool, and perform radar-like measurements
consisting of repeated measurements of such views of the internet topology. We
conduct long-term (several weeks) and high-speed (one round every few minutes)
measurements of this kind from more than one hundred monitors, and we provide
the obtained data. We also show that these data may be used to detect events in
the dynamics of internet topology.


title: Hermann type actions on a pseudo-Riemannian symmetric space

abstract:
  We first investigate the geometry of orbits of the isotropy action on a
semi-simple pseudo-Riemannian symmetric space by investigating the complexified
action. Next we investigate the geometry of the orbits of Hermann type actions
on the symmetric spaces. By considering two special Hermann type actions on the
symmetric space, we recognize an interesting structure of the symmetric space.


title: Forward Physics in Proton-Nucleus and Nucleus-Nucleus Collisions

abstract:
  We present an universal treatment for a substantial nuclear suppression
representing a common feature of all known reactions on nuclear targets
(forward production of high-pT hadrons, production of direct photons, the
Drell-Yan process, heavy flavor production, etc.). Such a suppression at large
Feynman xF, corresponding to region of minimal light-cone momentum fraction
variable x2 in nuclei, is tempting to interpret as a manifestation of coherence
or the Color Glass Condensate. We demonstrate, however, that it is actually a
simple consequence of energy conservation and takes place even at low energies,
where no effects of coherence are possible. We analyze this common suppression
mechanism for several processes performing model predictions in the light-cone
dipole approach. Our calculations agree with data.


title: Homogeneity of proper complex equifocal submanifolds

abstract:
  In this paper, we show that an irreducible proper complex equifocal
submanifold of codimension greater than one in a symmetric space of non-compact
type. The proof is performed by showing the homogeneity of the lift of the
complexification of the original submanifold to some infinite dimensional
anti-Kahelerian space.


title:
On equifocal submanifolds with non-flat section in symmetric spaces of
  rank two

abstract:
  In this paper, we show that there exists no equifocal submanifold with
non-flat section in four irreducible simply connected symmetric spaces of
compact type and rank two. Also, we show a fact for the sections of equifocal
submanifolds with non-flat section in other irreducible simply connected
symmetric spaces of compact type and rank two.


title: NMR implementations of Gauss sums

abstract:
  I describe the use of NMR experiments which implement Gauss sums as a method
for factoring numbers and discuss whether this approach can be computationally
useful.


title: Examples of a complex hyperpolar actions without singular orbit

abstract:
  The notion of a complex hyperpolar action on a symmetric space of non-compact
type has recently been introduced as counterpart of a hyperpolar action on a
symmetric space of compact type. In this paper, we construct examples of a
complex hyperpolar action without singular orbit and investigate the geometry
of the orbits of the examples.


title: Relativistic Nucleus-Nucleus Collisions and the QCD Matter Phase Diagram

abstract:
  This review will be concerned with our knowledge of extended matter under the
governance of strong interaction, in short: QCD matter. Strictly speaking, the
hadrons are representing the first layer of extended QCD architecture. In fact
we encounter the characteristic phenomena of confinement as distances grow to
the scale of 1 fm (i.e. hadron size): loss of the chiral symmetry property of
the elementary QCD Lagrangian via non-perturbative generation of "massive"
quark and gluon condensates, that replace the bare QCD vacuum. However, given
such first experiences of transition from short range perturbative QCD
phenomena (jet physics etc.), toward extended, non perturbative QCD hadron
structure, we shall proceed here to systems with dimensions far exceeding the
force range: matter in the interior of heavy nuclei, or in neutron stars, and
primordial matter in the cosmological era from electro-weak decoupling (10^-12
s) to hadron formation (0.5 10^-5 s). This primordial matter, prior to
hadronization, should be deconfined in its QCD sector, forming a plasma (i.e.
color conducting) state of quarks and gluons: the Quark Gluon Plasma (QGP).


title:
Adsorption of metal impurities on H-terminated Si surfaces and their
  influence on the wet chemical etching of Si

abstract:
  We use first-principles methods to investigate the adsorption of Cu, Pb, Ag,
and Mg onto a H-terminated Si surface. We show that Cu and Pb can adsorb
strongly while Ag and Mg are fairly inert. In addition, two types of adsorption
states are seen to exist for Pb. We also study the clustering energetics of Cu
and Pb on the surface and find that while Cu clusters eagerly, Pb may prefer to
form only small clusters of a few atoms. This kind of behavior of impurities is
incorporated in kinetic Monte Carlo simulations of wet etching of Si. The
simulation results agree with experiments supporting the idea that micromasking
by Cu clusters and Pb atoms is the mechanism through which these impurities
affect the etching process.


title:
A precise new KLOE measurement of $F_\pi$ with ISR events and
  determination of $\pi\pi$ contribution to $a_\mu$ for [0.35,0.95] GeV$^2$

abstract:
  The KLOE experiment at the DA$\Phi$NE $\phi$-factory has performed a new
precise measurement of the pion form factor using Initial State Radiation
events, with photons emitted at small polar angle. Results based on an
integrated luminosity of 240 pb$^{-1}$ and extraction of the $\pi\pi$
contribution to $a_\mu$ in the mass range [0.35,0.95] GeV$^2$ are presented,
the systematic uncertainty is reduced with respect to the published KLOE
result.


title: Conical Emission in Heavy Ion Collisions

abstract:
  A broadened or double humped away-side structure was observed in 2-particle
azimuthal jet-like correlations at RHIC and SPS. This modification can be
explained by conical emission, from either Mach-cone shock waves or Cherenkov
gluon radiation, and by other physics mechanisms, such as large angle gluon
radiation, jets deflected by radial flow and path-length dependent energy loss.
Three-particle jet-like correlations are studied for their power to distinguish
conical emission from other mechanisms. This article discusses Mach-cone shock
waves, Cherenkov gluon radiation and the experimental evidence for conical
emission from RHIC and SPS.


title: ICM properties and AGN distribution in high-z RCS clusters

abstract:
  Here we discuss the X-ray properties of clusters of galaxies optically
selected in the Red-Sequence Cluster Survey (RCS) observed with the Chandra
satellite, at redshifts 0.6 < z < 1.2. We intended to assess the evolutionary
stage of optically selected high-z clusters of galaxies, performing a spectral
analysis of the diffuse emission from their ICM. We also investigated the
distribution of AGN in their surroundings. The background subtracted spectra
were analyzed and fitted with a single temperature model to measure average ICM
temperature, X-ray bolometric luminosity and Fe abundance within typical radii
between 200 and 350 kpc. We also analyzed the point source number density and
spatial distribution in the RCS clusters fields as a function of the X-ray
flux. We detected emission for the majority of the clusters, except for three,
for which we have only marginal detection at ~3 Sigma. We find that the
normalization of the L-T relation for RCS clusters is a factor of ~2 lower than
the one for X-ray selected clusters. We confirm that the Fe abundance in the
detected objects is consistent with that of X-ray selected clusters at the same
redshift. We also found an excess of low-luminosity AGN towards the center of
the clusters.


title:
Ergodic actions of mapping class groups on moduli spaces of
  representations of non-orientable surfaces

abstract:
  The purpose of this paper is to study the action of the mapping class group
on the moduli space of representations of the fundamental group of a
non-orientable surface into SU(2). The action is shown to be ergodic with
respect to a natural measure. This measure is defined using the push-forward
measure associated to a map defined by the presentation of the surface group.
given by the pushforward of Haar measure. This result is an extension of
earlier results of Goldman for orientable surfaces.


title: A Swift BAT Look at Super-Orbital X-ray Binaries

abstract:
  We present the results of a study with the Swift Burst Alert Telescope in the
14 - 195 keV range of the long-term variability of 5 low mass X-ray binaries
with reported or suspected super-orbital periods -- 4U 1636-536, 4U 1820-303,
4U 1916-053, Cyg X-2 and Sco X-1. No significant periodic modulation was
detected around the previously reported values in the 4U 1916-053, Cyg X-2 or
Sco X-1 light curves. The $\sim$170 d period of 4U 1820-303 was detected up to
24 keV, consistent with the proposed triple system model. The $\sim$46 d period
in 4U 1636-536 was detected up to 100 keV, clearly inconsistent with variable
photoelectric absorption via a warped precessing disc. We speculate that the
appearance of this modulation after 4U 1636-536 entered the low/hard state
indicates that this variability could be linked to jet precession such as
observed in SS 433.


title:
Near-IR Spectrograph for VSI (VLTI Spectro Imager): dispersing the light
  from an integrated optics beam-combiner

abstract:
  We present the optical and cryo-mechanical solutions for the Spectrograph of
VSI (VLTI Spectro-Imager), the second generation near-infrared (J, H and K
bands) interferometric instrument for the VLTI. The peculiarity of this
spectrograph is represented by the Integrated Optics (IO) beam-combiner, a
small and delicate component which is located inside the cryostat and makes VSI
capable to coherently combine 4, 6 or even 8 telescopes. The optics have been
specifically designed to match the IO combiner output with the IR detector
still preserving the needed spatial and spectral sampling, as well as the
required fringe spacing. A compact device that allows us to interchange
spectral resolutions (from R=200 to R=12000), is also presented.


title:
Improved model for the topological soliton-potential interaction in
  Phi^4 Model

abstract:
  An improved model for the soliton-potential interaction is presented. This
model is constructed with a better approximation for adding the potential to
the lagrangian through a space-time metric. The results of the model are
compared with other models and the differences are discussed.


title: Colloidal Micromotors: Controlled Directed Motion

abstract:
  Here we demonstrate a synthetic micro-engine, based on long-range controlled
movement of colloidal particles, which is induced by a local catalytic
reaction. The directed motion at long timescales was achieved by placing
specially designed magnetic capped colloids in a hydrogen peroxide solution at
weak magnetic fields. The control of the motion of the particles was provided
by changes of the concentration of the solution and by varying the strength of
the applied magnetic field. Such synthetic objects can then be used not only to
understand the fundamental driving processes but also be employed as small
motors in biological environments, for example, for the transportation of
molecules in a controllable way.


title: Finding Short Cycles in an Embedded Graph in Polynomial Time

abstract:
  Let ${\cal{C}}_1$ be the set of fundamental cycles of breadth-first-search
trees in a graph $G$ and ${\cal{C}}_2$ the set of the sums of two cycles in
${\cal{C}}_1$. Then we show that $(1) {\cal{C}}={\cal{C}}_1\bigcup{\cal{C}}_2$
contains a shortest $\Pi$-twosided cycle in a $\Pi$-embedded graph $G$;$(2)$
$\cal{C}$ contains all the possible shortest even cycles in a graph $G$;$(3)$
If a shortest cycle in a graph $G$ is an odd cycle, then $\cal{C}$ contains all
the shortest odd cycles in $G$. This implies the existence of a polynomially
bounded algorithm to find a shortest $\Pi-$twosided cycle in an embedded graph
and thus solves an open problem of B.Mohar and C.Thomassen[2,pp112]


title: First study of the three-gluon static potential in Lattice QCD

abstract:
  We estimate the potential energy for a system of three static gluons in
Lattice QCD. This is relevant for the different models of three-body glueballs
have been proposed in the literature, either for gluons with a constituent
mass, or for massless ones. A Wilson loop adequate to the static hybrid
three-body system is developed. We study different spacial geometries, to
compare the starfish model with the triangle model, for the three-gluon
potential. We also study two different colour structures, symmetric and
antisymmetric, and compare the respective static potentials. A first simulation
is performed in a $24^3 \times 48$ periodic Lattice, with $\beta=6.2$ and $a
\sim 0.072$ fm.


title:
Superfluid equation of state of cold fermionic gases in the
  Bose-Einstein regime

abstract:
  We present an exact many-body theory of ultracold fermionic gases for the
Bose-Einstein condensation (BEC) regime of the BEC-BCS crossover. This is a
purely fermionic approach which treats explicitely and systematically the
dimers formed in the BEC regime as made of two fermions. We consider
specifically the zero temperature case and calculate the first terms of the
expansion of the chemical potential in powers of the density $n$. We derive
first the mean-field contribution, which has the expected standard expression
when it is written in terms of the dimer-dimer scattering length $a_M$. We go
next in the expansion to the Lee-Huang-Yang order, proportional to $n^{3/2}$.
We find the far less obvious result that it retains also the same expression in
terms of $a_M$ as for elementary bosons. The composite nature of the dimers
appears only in the next term proportional to $n^2$.


title:
Accuracy of the diffusion equation with extrapolated-boundary condition
  for transmittance of light through a turbid medium

abstract:
  The linear intensity profile of multiply scattered light in a slab geometry
extrapolates to zero at a certain distance beyond the boundary. The diffusion
equation with this "extrapolated boundary condition" has been used in the
literature to obtain analytical formulas for the transmittance of light through
the slab as a function of angle of incidence and refractive index. The accuracy
of these formulas is determined by comparison with a numerical solution of the
Boltzmann equation for radiative transfer.


title:
As an Introduction: Quest for New Physics in Photon-Photon Interactions
  at the LHC

abstract:
  A significant fraction of pp collisions at the LHC will involve (quasi-real)
photon interactions occurring at energies well beyond the electroweak energy
scale. Hence, the LHC can to some extend be considered as a high-energy
photon-photon or photon-proton collider. This offers a unique possibility for
novel and complementary research where the available effective luminosity is
small, relative to parton-parton interactions, but it is compensated by better
known initial conditions and usually simpler final states. This is in a way a
method for approaching some of the issues to be addressed by the future lepton
collider. Such studies of photon interactions are possible at the LHC, thanks
to the striking experimental signatures of events involving photon exchanges,
in particular the presence of very forward scattered protons.


title:
Magnetic field distribution in the quiet Sun: a simplified model
  approach

abstract:
  We simulate the dynamics and the evolution of quiet Sun magnetic elements to
produce a probability density function of the field strengths associated with
such elements. The dynamics of the magnetic field are simulated through a
numerical model in which magnetic elements are passively driven by an advection
field presenting spatio-temporal correlations which mimicks the granulation and
the mesogranulation scales observed on the solar surface. The field strength
can increase due to an amplification process which takes place where the
magnetic elements converge. Starting from a delta-like probability density
function centered on B=30 G, we obtain magnetic field strengths up to 2 kG (in
absolute value). To derive the statistical properties of the magnetic elements
several simulation runs are performed. The model is able to produce kG magnetic
fields in a time interval of the order of the granulation time scale. The mean
unsigned flux density and the mean magnetic energy density of the synthetic
quiet Sun reach respectively 100 G and 350 G in the stationary regime. The
derived probability density function of the magnetic field strength decreases
rapidly from B=30 G to B=100 G and presents a secondary maximum for B=2 kG.
  From this result it follows that magnetic fields >700 G dominate the unsigned
flux density and magnetic energy density although the probability density
function of the field strength presents a maximum for B=30 G.


title:
Beyond the simple Proximity Force Approximation: geometrical effects on
  the non-retarded Casimir interaction

abstract:
  We study the geometrical corrections to the simple Proximity Force
Approximation for the non-retarded Casimir force. We present analytical results
for the force between objects of various shapes and substrates, and between
pairs of objects. We compare the results to those from more exact numerical
calculations. We treat spheres, spheroids, cylinders, cubes, cones, and wings;
the analytical PFA results together with the geometrical correction factors are
summarized in a table.


title:
Spin rotations induced by electron running on closed trajectories in
  gated semiconductor nanodevices

abstract:
  A design for a quantum gate performing transformations of a single electron
spin is presented. The spin rotations are performed by the electron going
around the closed loops in a gated semiconductor device. We demonstrate the
operation of NOT, phase-flip and Hadamard quantum gates, i.e. the single-qubit
gates which are most commonly used in the algorithms. The proposed devices
employ the self-focusing effect for the electron wave packet interacting with
the electron gas on the electrodes and the Rashba spin-orbit coupling. Due to
the self-focusing effect the electron moves in a compact wave packet. The
spin-orbit coupling translates the spatial motion of the electron into the
rotations of the spin. The device does not require microwave radiation and
operates using low constant voltages. It is therefore suitable for selective
single-spin rotations in larger registers.


title: Piatetski-Shapiro's phenomenon and related problems

abstract:
  This Ph.D. thesis, prepared under the supervision of Prof. Alexander
Olevskii, is concerned with some problems in two areas of Fourier Analysis:
uniqueness theory of trigonometric expansions, and the theory of translation
invariant subspaces in function spaces. Our main result in the first area
extends to $\ell_q$ spaces ($q > 2$) a deep phenomenon found by
Piatetski-Shapiro in 1954 for the space $c_0$. The approach we developed also
enabled us to get a result in the second mentioned area, which a priori does
not look connected with the first one. The result (maybe, a bit surprising) is:
one cannot characterize the functions in $\ell_p(\Z)$ or $L^p(\R)$, $1 < p <
2$, whose translates span the whole space, by the zero set of their Fourier
transform. This should be contrasted against the classical Wiener theorems
related to the cases $p=1,2$.


title:
From Grad-Shafranov equations set to a pseudo-general form of the
  non-linear Schroedinger equation

abstract:
  In the year 2003 a paper by G. Lapenta demonstrated that there is a new class
of soliton-like solutions for the Grad-Shafranov Equations (GSE).The author
determined an appropriate pair of transformations of the free fields p (fluid
field of hydrodynamical pressure) and Bz (z- component of magnetic induction
field) that leads from the Helmholtz Equation to the Non-Linear Schroedinger
Equation (NLSE) with cubic non- linearity. In the following year (2004), the
work of Lapenta was opposed by G.N. Throumoulopoulos et al.,who criticized his
idea of the field transformations as a mathematically incoherent choice;
contextually the authors suggested a new point of view for this one. In his
response, in the same year, G. Lapenta carried out numerical simulations that
showed the existence of solitonic structures in a Magnetohydrodynamical (MHD)
plasma-context. In the present work I want to demonstrate a critical condition
for a complex poloidal flux function psi in a plane framework (x;y) that leads
to a class of pseudo-general NLSEs which establishes the validity of both
G.Lapenta and G.N. Throumoulopoulos et al. choices for the field transformation
functionals.


title:
Probing helium interfaces with light scattering : from fluid mechanics
  to statistical physics

abstract:
  We have investigated the formation of helium droplets in two physical
situations. In the first one, droplets are atomised from superfluid or normal
liquid by a fast helium vapour flow. In the second, droplets of normal liquid
are formed inside porous glasses during the process of helium condensation. The
context, aims, and results of these experiments are reviewed, with focus on the
specificity of light scattering by helium. In particular, we discuss how, for
different reasons, the closeness to unity of the index of refraction of helium
allows in both cases to minimise the problem of multiple scattering and obtain
results which it would not be possible to get using other fluids.

categories: cond-mat.soft cond-mat.stat-mech physics.class-ph physics.optics


title: Phonon renormalisation in doped bilayer graphene

abstract:
  We report phonon renormalisation in bilayer graphene as a function of doping.
The Raman G peak stiffens and sharpens for both electron and hole doping, as a
result of the non-adiabatic Kohn anomaly at the $\Gamma$ point. The bilayer has
two conduction and valence subbands, with splitting dependent on the interlayer
coupling. This results in a change of slope in the variation of G peak position
with doping, which allows a direct measurement of the interlayer coupling
strength.


title: The centipede is determined by its Laplacian spectrum

abstract:
  A centipede is a graph obtained by appending a pendant vertex to each vertex
of degree 2 of a path. In this paper we prove that the centipede is determined
by its Laplacian spectrum.


title:
Continuous dependence results for Non-linear Neumann type boundary value
  problems

abstract:
  We obtain estimates on the continuous dependence on the coefficient for
second order non-linear degenerate Neumann type boundary value problems. Our
results extend previous work of Cockburn et.al., Jakobsen-Karlsen, and
Gripenberg to problems with more general boundary conditions and domains. A new
feature here is that we account for the dependence on the boundary conditions.
As one application of our continuous dependence results, we derive for the
first time the rate of convergence for the vanishing viscosity method for such
problems. We also derive new explicit continuous dependence on the coefficients
results for problems involving Bellman-Isaacs equations and certain quasilinear
equation.


title:
Direct/indirect detection signatures of nonthermally produced dark
  matter

abstract:
  We study direct and indirect detection possibilities of neutralino dark
matter produced non-thermally by e.g. the decay of long-lived particles, as is
easily implemented in the case of anomaly or mirage mediation models. In this
scenario, large self-annihilation cross sections are required to account for
the present dark matter abundance, and it leads to significant enhancement of
the gamma-ray signature from the Galactic Center and the positron flux from the
dark matter annihilation. It is found that GLAST and PAMELA will find the
signal or give tight constraints on such nonthermal production scenarios of
neutralino dark matter.


title: Dark energy: myths and reality

abstract:
  We discuss the questions related to dark energy in the Universe. We note that
in spite of the effect of dark energy, large-scale structure is still being
generated in the Universe and this will continue for about ten billion years.
We also comment on some statements in the paper ``Dark energy and universal
antigravitation'' by A.D. Chernin [4].


title: Analysis of parity nonconservation in the Ra+-ion

abstract:
  We report on a theoretical analysis of the suitability of the 7s 2S1/2 <-> 6d
2D3/2 transition in singly ionized radium to measure parity nonconservation, in
the light of an experiment planned at the KVI of the University of Groningen.
Relativistic coupled-cluster theory has been employed to perform an ab initio
calculation of the parity nonconserving electric dipole amplitude of this
transition, including single, double, and leading triple excitations. We
discuss the prospects for a sub-1% precision test of the electroweak theory of
particle physics.


title: Entangling neutrons via successive scattering from a substrate

abstract:
  This letter details a simple scheme to entangle two neutrons by successive
scattering from a macroscopic sample. In zero magnetic field the entanglement
falls as the sample size increases. However, by applying a field and tuning the
momentum of the neutrons, one can achieve a substantial degree of entanglement
irrespective of the size of the sample.


title:
Proposed Universal Relationships Describing Electron Phonon Mediated
  Superconductivity and Accommodation of the Cuprates and Pnictides

abstract:
  A universal and self-consistent set of equations is developed utilizing the
principle empirical parameters of Superconductivity which are the coherent
condensation temperature, the Debye temperature, the coherent condensation
energy gap at critical temperature equals zero degrees Kelvin and the electron
phonon coupling constant. Empirical data from both crystalline elements and
amorphous compounds is shown to produce the same self consistent relationships
which are critical temperature equals Debye energy/2 exp(-2/electron phonon
coupling constant), coherent condensation temperature equals the Debye energy
exp (-2/electron phonon coupling constant) and the ratio of coherent
condensation temperature/critical temperature equals 2.0 i.e. coherent
condensation temperature equals coherent energy gap and is found to be constant
for all superconductors. We also find that electron phonon coupling constant is
related exponentially related to the zero point energy where the zero point
energy equals the Debye energy/2 and is the zero point energy of a quantum
mechanical oscillator. These relationships are derived exclusively from
electron phonon mediated superconductor data and are also shown to encompass
cuprate superconductors with ease. [Abridged]


title:
Global recessions as a cascade phenomenon with heterogenous, interacting
  agents

abstract:
  I examine global recessions as a cascade phenomenon. In other words, how
recessions arising in one or more countries might percolate across a network of
connected economies. A heterogeneous agent based model is set up in which the
agents are Western economies. A country has a probability of entering a
recession in any given year and one of emerging from it the next. In addition,
the agents have a unique threshold propensity to import a recession from the
agents with which they have the strongest connections. They are connected on a
small world topology, and an agent's neighbours at any time are either in
(state 1) or out (state 0) of recession. If the weighted sum exceeds the
threshold, the agent goes into recession. Annual real GDP growth for 17 Western
countries 1871-2006 is used as the data set. The distribution of the number of
countries in recession in any given year is exponential, as is the duration of
recessions within individual countries. The model is calibrated against these
two facts, plus the 'wait time' between recessions. It is able to replicate
them successfully. The network structure is essential for the agents to
replicate the stylised facts. The country-specific probabilities of entering
and emerging from recession by themselves give results very different to the
actual data.


title: The dark side of gravity: Modified theories of gravity

abstract:
  Modern astrophysical and cosmological models are faced with two severe
theoretical difficulties, that can be summarized as the dark energy and the
dark matter problems. Relative to the former, it has been stated that cosmology
has entered a 'golden age', in which high-precision observational data have
confirmed with startling evidence that the Universe is undergoing a phase of
accelerated expansion. Several candidates, responsible for this expansion, have
been proposed in the literature, in particular, dark energy models and modified
gravity, amongst others. One is liable to ask: What is the so-called 'dark
energy' that is driving the acceleration of the universe? Is it a vacuum energy
or a dynamical field (''quintessence'')? Or is the acceleration due to
infra-red modifications of Einstein's theory of General Relativity? In the
context of dark matter, two observations, namely, the behavior of the galactic
rotation curves and the mass discrepancy in galactic clusters, suggest the
existence of a (non or weakly interacting) form of dark matter at galactic and
extra-galactic scales. It has also been proposed that modified gravity can
explain the galactic dynamics without the need of introducing dark matter. We
briefly review some of the modified theories of gravity that address these two
intriguing and exciting problems facing modern physics.


title: Vertex Algebroids over Veronese Rings

abstract:
  We find a canonical quantization of Courant algebroids over Veronese rings.
Part of our approach allows a semi-infinite cohomology interpretation, and the
latter can be used to define sheaves of chiral differential operators on some
homogeneous spaces including the space of pure spinors punctured at a point.


title: Fringe Tracker for the VLTI Spectro-Imager

abstract:
  The implementation of the simultaneous combination of several telescopes
(from four to eight) available at Very Large Telescope Interferometer (VLTI)
will allow the new generation interferometric instrumentation to achieve
interferometric image synthesis with unprecedented resolution and efficiency.
The VLTI Spectro Imager (VSI) is the proposed second-generation near-infrared
multi-beam instrument for the Very Large Telescope Interferometer, featuring
three band operations (J, H and K), high angular resolutions (down to 1.1
milliarcsecond) and high spectral resolutions. VSI will be equipped with its
own internal Fringe Tracker (FT), which will measure and compensate the
atmospheric perturbations to the relative beam phase, and in turn will provide
stable and prolonged observing conditions down to the magnitude K=13 for the
scientific combiner. In its baseline configuration, VSI FT is designed to
implement, from the very start, the minimum redundancy combination in a nearest
neighbor scheme of six telescopes over six baselines, thus offering better
options for rejection of large intensity or phase fluctuations over each beam,
due to the symmetric set-up. The planar geometry solution of the FT beam
combiner is devised to be easily scalable either to four or eight telescopes,
in accordance to the three phase development considered for VSI. The proposed
design, based on minimum redundancy combination and bulk optics solution, is
described in terms of opto-mechanical concept, performance and key operational
aspects.


title:
Brief review related to the foundations of time-dependent density
  functional theory

abstract:
  The electron density $n(\rb,t)$, which is the central tool of time-dependent
density functional theory, is presently considered to be derivable from a
one-body time-dependent potential $V(\rb,t)$, via one-electron wave functions
satisfying a time- dependent Schr\"{o}dinger equation. This is here related via
a generalized equation of motion to a Dirac density matrix now involving $t$.
Linear response theory is then surveyed, with a special emphasis on the
question of causality with respect to the density dependence of the potential.
Extraction of $V(\rb,t)$ for solvable models is also proposed.


title:
Sur la Caracterisation des Retractes Holomorphes a l'aide de la Metrique
  Infinitesimale de Kobayashi

abstract:
  Dans cet article, on donne une caracterisation des retractes holomorphes a
l'aide de la metrique infinitesimale de Kobayashi
  -----
  This article gives a characterization of holomorphic retractions using
Kobayashi's infinitesimal metric.


title: Schwarzenberger bundles of arbitary rank on the projective space

abstract:
  We introduce a generalized notion of Schwarzenberger bundle on the projective
space. Associated to this more general definition, we give an ad-hoc notion of
jumping subspaces of a Steiner bundle on ${\Bbb P^n}$ (which in rank $n$
coincides with the notion of unstable hyperplane introduced by Vall\`es, Ancona
and Ottaviani). For the set of jumping hyperplanes, we find a sharp bound for
its dimension. We also classify those Steiner bundles whose set of jumping
hyperplanes have maximal dimension and prove that they are generalized
Schwarzenberger bundles.


title: New Results in Four and Five Loop QED calculations

abstract:
  We report on two recent multiloop results in QED: (i) the four-loop
corrections to the conversion relations between the QED charge renormalized in
the on-shell and MS-bar schemes; (ii) analytical evaluation of a class of
asymptotic contributions to the muon anomaly at five-loops.


title:
Growth of flat SrRuO3(111) thin films suitable as bottom electrodes in
  heterostructures

abstract:
  Thin film growth of ferroelectric or multiferroic materials on SrTiO3(111)
with a buffer electrode has been hampered by the difficulty of growing flat
electrodes on this polar orientation. We report on the growth and
characterization of SrRuO3 thin films deposited by pulsed laser deposition on
SrTiO3(111). We show that our SrRuO3(111) films are epitaxial and display
magnetic bulk-like properties. Films presenting a thickness between 20 and 30nm
are found to be very flat (with an RMS of about 0.5 nm) and therefore suitable
as bottom electrodes in heterostructures.


title:
Two Dimensional Incompressible Viscous Flow Around a Thin Obstacle
  Tending to a Curve

abstract:
  In [Lacave, IHP, ana, to appear (2008)] the author considered the two
dimensional Euler equations in the exterior of a thin obstacle shrinking to a
curve and determined the limit velocity. In the present work, we consider the
same problem in the viscous case, proving convergence to a solution of the
Navier-Stokes equations in the exterior of a curve. The uniqueness of the limit
solution is also shown.


title:
Global fluctuations in physical systems: a subtle interplay between sum
  and extreme value statistics

abstract:
  Fluctuations of global additive quantities, like total energy or
magnetization for instance, can in principle be described by statistics of sums
of (possibly correlated) random variables. Yet, it turns out that extreme
values (the largest value among a set of random variables) may also play a role
in the statistics of global quantities, in a direct or indirect way. This
review discusses different connections that may appear between problems of sums
and of extreme values of random variables, and emphasizes physical situations
in which such connections are relevant. Along this line of thought, standard
convergence theorems for sums and extreme values of independent and identically
distributed random variables are recalled, and some rigorous results as well as
more heuristic reasonings are presented for correlated or non-identically
distributed random variables. More specifically, the role of extreme values
within sums of broadly distributed variables is addressed, and a general
mapping between extreme values and sums is presented, allowing us to identify a
class of correlated random variables whose sum follows (generalized) extreme
value distributions. Possible applications of this specific class of random
variables are illustrated on the example of two simple physical models. A few
extensions to other related classes of random variables sharing similar
qualitative properties are also briefly discussed, in connection with the
so-called BHP distribution.


title:
Surface Potentials and Layer Charge Distributions in Few-Layer Graphene
  Films

abstract:
  Graphene-derived nanomaterials are emerging as ideal candidates for
postsilicon electronics. Elucidating the electronic interaction between an
insulating substrate and few-layer graphene (FLG) films is crucial for device
applications. Here, we report electrostatic force microscopy (EFM) measurements
revealing that the FLG surface potential increases with film thickness,
approaching a "bulk" value for samples with five or more graphene layers. This
behavior is in sharp contrast with that expected for conventional conducting or
semiconducting films, and derives from unique aspects of charge screening by
graphene's relativistic low energy carriers. EFM measurements resolve
previously unseen electronic perturbations extended along crystallographic
directions of structurally disordered FLGs, likely resulting from long-range
atomic defects. These results have important implications for graphene
nanoelectronics and provide a powerful framework by which key properties can be
further investigated.


title: The lazy homology of a Hopf algebra

abstract:
  To any Hopf algebra H we associate two commutative Hopf algebras, which we
call the first and second lazy homology Hopf algebras of H. These algebras are
related to the lazy cohomology groups based on the so-called lazy cocycles of H
by universal coefficient theorems. When H is a group algebra, then its lazy
homology can be expressed in terms of the 1- and 2-homology of the group. When
H is a cosemisimple Hopf algebra over an algebraically closed field of
characteristic zero, then its first lazy homology is the Hopf algebra of the
universal abelian grading group of the category of corepresentations of H. We
also compute the lazy homology of the Sweedler algebra.


title: Fundamental Cycles and Graph Embeddings

abstract:
  In this paper we present a new Good Characterization of maximum genus of a
graph which makes a common generalization of the works of Xuong, Liu, and Fu et
al. Based on this, we find a new polynomially bounded algorithm to find the
maximum genus of a graph.


title: Magnetic and dielectric properties of YbMnO3 perovskite thin films

abstract:
  Metastable manganite perovskites displaying the antiferromagnetic so-called
E-phase are predicted to be multiferroic. Due to the need of high-pressures for
the synthesis of this phase, this prediction has only been confirmed in bulk
HoMnO3. Here we report on the growth and characterization of YbMnO3 perovskite
thin films grown under epitaxial strain. Highly-oriented thin films, with
thickness down to ~30nm, can be obtained showing magneto-dielectric coupling
and magnetic responses as those expected for the E-phase. We observe that the
magnetic properties depart from the bulk behavior only in the case of ultrathin
films (d< 30nm), which display a glassy magnetic behavior. We show that strain
effects alone cannot account for this difference and that the film morphology
plays, instead, a crucial role.


title: Centers of F-purity

abstract:
  In this paper, we study a positive characteristic analogue of the centers of
log canonicity of a pair $(R, \Delta)$. We call these analogues centers of
$F$-purity. We prove positive characteristic analogues of subadjunction-like
results, prove new stronger subadjunction-like results, and in some cases, lift
these new results to characteristic zero. Using a generalization of centers of
$F$-purity which we call uniformly $F$-compatible ideals, we give a
characterization of the test ideal (which unifies several previous
characterizations). Finally, in the case that $\Delta = 0$, we show that
uniformly $F$-compatible ideals coincide with the annihilators of the
$\mathcal{F}(E_R(k))$-submodules of $E_R(k)$ as defined by Smith and Lyubeznik.


title: Pure cross-diffusion models: Implications for traveling wave solutions

abstract:
  An analysis of traveling wave solutions of pure cross-diffusion systems,
i.e., systems that lack reaction and self-diffusion terms, is presented. Using
the qualitative theory of phase plane analysis the conditions for existence of
different types of wave solutions are formulated. In particular, it is shown
that family of wave trains is a generic phenomenon in pure cross-diffusion
systems. The results can be used for construction and analysis of different
mathematical models describing systems with directional movement.


title: Verifying the Congruence Conjecture for Rubin-Stark Elements

abstract:
  The `Congruence Conjecture' was developed by the second author in a previous
paper. It provides a conjectural explicit reciprocity law for a certain element
associated to an abelian extension of a totally real number field whose
existence is predicted by earlier conjectures of Rubin and Stark. The first aim
of the present paper is to design and apply techniques to investigate the
Congruence Conjecture numerically. We then present complete verifications of
the conjecture in 48 varied cases with real quadratic base fields.


title: Quantum Cloning without Interference

abstract:
  We study the role of interference in the process of quantum cloning. We show
that in order to achieve better than classical cloning of a qubit no
interference is needed. In particular, a large class of symmetric universal
1$\to$ 2 qubit cloners exists which achieve the optimal average fidelity 5/6
for such machines, without using any interference. We also obtain optimal
average fidelities for interference--free cloning in asymmetric situations, and
discuss the relation of the quantum cloners found to the Bu\v{z}ek--Hillery
quantum cloner.