title:
Dynamic communities in multichannel data: An application to the foreign
  exchange market during the 2007--2008 credit crisis

abstract:
  We study the cluster dynamics of multichannel (multivariate) time series by
representing their correlations as time-dependent networks and investigating
the evolution of network communities. We employ a node-centric approach that
allows us to track the effects of the community evolution on the functional
roles of individual nodes without having to track entire communities. As an
example, we consider a foreign exchange market network in which each node
represents an exchange rate and each edge represents a time-dependent
correlation between the rates. We study the period 2005-2008, which includes
the recent credit and liquidity crisis. Using dynamical community detection, we
find that exchange rates that are strongly attached to their community are
persistently grouped with the same set of rates, whereas exchange rates that
are important for the transfer of information tend to be positioned on the
edges of communities. Our analysis successfully uncovers major trading changes
that occurred in the market during the credit crisis.

categories: physics.soc-ph nlin.AO physics.data-an q-fin.TR


title: Solar-like oscillations in the G8 V star tau Ceti

abstract:
  We used HARPS to measure oscillations in the low-mass star tau Cet. Although
the data were compromised by instrumental noise, we have been able to extract
the main features of the oscillations. We found tau Cet to oscillate with an
amplitude that is about half that of the Sun, and with a mode lifetime that is
slightly shorter than solar. The large frequency separation is 169 muHz, and we
have identified modes with degrees 0, 1, 2, and 3. We used the frequencies to
estimate the mean density of the star to an accuracy of 0.45% which, combined
with the interferometric radius, gives a mass of 0.783 +/- 0.012 M_sun (1.6%).


title:
Phase transitions in infinitely generated groups, and related problems
  in additive number theory

abstract:
  Let A be an infinite set of generators for a group G, and let L_A(r) denote
the number of elements of G whose word length with respect to A is exactly r.
The purpose of this note is to determine all growth functions L_A(r) associated
to infinite generating sets for groups, and to describe a phase transition
phenomenon associated with infinite generating sets. A list of open problems is
also.included.


title: Centers of cyclotomic Sergeev superalgebras

abstract:
  We prove that the natural map from the center of the affine Sergeev
superalgebra to the even center of any cyclotomic Sergeev superalgebra of odd
level is surjective, hence that the even center of a cyclotomic Sergeev
superalgebra of odd level consists of symmetric functions in the squares of its
polynomial generators.


title:
Variation of the Fine-Structure Constant and Laser Cooling of Atomic
  Dysprosium

abstract:
  Radio-frequency electric-dipole transitions between nearly degenerate,
opposite parity levels of atomic dysprosium (Dy) were monitored over an
eight-month period to search for a variation in the fine-structure constant,
$\alpha$. The data provide a rate of fractional temporal variation of $\alpha$
of $(-2.4\pm2.3)\times10^{-15}$ yr$^{-1}$ or a value of $(-7.8 \pm 5.9) \times
10^{-6}$ for $k_\alpha$, the variation coefficient for $\alpha$ in a changing
gravitational potential. All results indicate the absence of significant
variation at the present level of sensitivity. We also present initial results
on laser cooling of an atomic beam of dysprosium.


title:
Atomic Bloch-Zener oscillations for sensitive force measurements in a
  cavity

abstract:
  Cold atoms in an optical lattice execute Bloch-Zener oscillations when they
are accelerated. We have performed a theoretical investigation into the case
when the optical lattice is the intra-cavity field of a driven Fabry-Perot
resonator. When the atoms oscillate inside the resonator, we find that their
back-action modulates the phase and intensity of the light transmitted through
the cavity. We solve the coupled atom-light equations self-consistently and
show that, remarkably, the Bloch period is unaffected by this back-action. The
transmitted light provides a way to observe the oscillation continuously,
allowing high precision measurements to be made with a small cloud of atoms.


title:
Psuedo-isotropic upper critical field in cobalt-doped SrFe2As2 epitaxial
  films

abstract:
  The temperature and angular dependence of the upper critical field (Hc2) is
reported for cobalt-doped SrFe2As2 epitaxial films between Tc and 0.5 K in
pulsed magnetic fields up to 50 T. For H parallel c, Hc2 is close to a linear
function of temperature, while in the perpendicular direction there is
significant downward curvature that results in an Hc2 ratio (gamma =
Hc2(perpendicular)/Hc2(parallel) that decreases nearly linearly with
temperature, approaching gamma = 1 at low temperature with Hc2(0) = 47 T. We
measure the complete upper-critical field phase diagram including angular
dependence and model the data using a two band theory allowing us to determine
the anisotropy of both bands, their relative diffusivities, and the
relationship between BCS coupling constant matrix elements. We find an unusual
relationship between the diffusivities of the two bands, with two anisotropic
and opposite bands. This relationship is supported by the observation of a
local maximum for Hc2(parallel) at low temperature.


title: R-parity conserving SUSY searches in ATLAS

abstract:
  Searches for physics beyond the Standard Model of particle physics are about
to enter a new era with the startup of the Large Hadron Collider (LHC) at CERN.
Prospects for R-parity conserving supersymmetry discovery and measurements with
the ATLAS detector at the LHC are presented. Methods for determining the
parameters of the underlying supersymmetry model and the relation to dark
matter estimation are discussed.


title: Stochastic pumping of heat: Approaching the Carnot efficiency

abstract:
  Random noise can generate a unidirectional heat current across asymmetric
nano objects in the absence (or against) a temperature gradient. We present a
minimal model for a molecular-level stochastic heat pump that may operate
arbitrarily close to the Carnot efficiency. The model consists a fluctuating
molecular unit coupled to two solids characterized by distinct phonon spectral
properties. Heat pumping persists for a broad range of system and bath
parameters. Furthermore, by filtering the reservoirs' phonons the pump
efficiency can approach the Carnot limit.


title: Distributive lattices and cohomology

abstract:
  A resolution of the intersection of a finite number of subgroups of an
abelian group by means of their sums is constructed, provided the lattice
generated by these subgroups is distributive. This is used for detecting
singularities of modules over Dedekind rings. A generalized Chinese remainder
theorem is derived as a consequence of the above resolution. The
Gelfand-Naimark duality between finite closed coverings of compact Hausdorff
spaces and the generalized Chinese remainder theorem is clarified.


title: On Effective log Iitaka Fibration for 3-folds and 4-folds

abstract:
  We prove the effectiveness of the log Iitaka fibration in Kodaira codimension
two for varieties of dimension$\le 4$. In particular, we finish the proof of
effective log Iitaka fibration in dimension two. Also, we show that for the log
Iitaka fibration, if the fiber is of dimension two, the denominator of the
moduli part is bounded.


title: Massless Poincare modules and gauge invariant equations

abstract:
  Starting with an indecomposable Poincare module M_0 induced from a given
irreducible Lorentz module we construct a free Poincare invariant gauge theory
defined on the Minkowski space. The space of its gauge inequivalent solutions
coincides with (in general, is closely related to) the starting point module
M_0. We show that for a class of indecomposable Poincare modules the resulting
theory is a Lagrangian gauge theory of the mixed-symmetry higher spin fields.
The procedure is based on constructing the parent formulation of the theory.
The Labastida formulation and the unfolded description of the mixed symmetry
fields are reproduced through the appropriate reductions of the parent
formulation. As an independent check we show that in the momentum
representation the solutions form a unitary irreducible Poincare module
determined by the respective module of the Wigner little group.


title: Hamiltonian decomposition for bulk and surface states

abstract:
  We demonstrate that a tight-binding Hamiltonian with nearest- and
next-nearest-neighbor hopping integrals can be decomposed into bulk and
boundary parts in a general lattice system. The Hamiltonian decomposition
reveals that next nearest-neighbor hopping causes sizable changes in the energy
spectrum of surface states even if the correction to the energy spectrum of
bulk states is negligible. By applying the Hamiltonian decomposition to edge
states in graphene systems, we show that the next nearest-neighbor hopping
stabilizes the edge states.


title: Separation of Relatively Quasiconvex Subgroups

abstract:
  Suppose that all hyperbolic groups are residually finite. The following
statements follow: In relatively hyperbolic groups with peripheral structures
consisting of finitely generated nilpotent subgroups, quasiconvex subgroups are
separable; Geometrically finite subgroups of non-uniform lattices in rank one
symmetric spaces are separable; Kleinian groups are subgroup separable. We also
show that LERF for finite volume hyperbolic 3-manifolds would follow from LERF
for closed hyperbolic 3-manifolds.
  The method is to reduce, via combination and filling theorems, the
separability of a quasiconvex subgroup of a relatively hyperbolic group G to
the separability of a quasiconvex subgroup of a hyperbolic quotient G/N. A
result of Agol, Groves, and Manning is then applied.


title: Magneto-oscillations in Underdoped Cuprates

abstract:
  The conventional interpretation of the recent magneto-oscillation experiments
in underdoped Cuprates, requires that there be a state of altered translational
symmetry in the pseudogap state which is not supported by structural and Angle
Resolved Photoemission Spectroscopy (ARPES) experiments. I show here that the
observed oscillations may be reconciled with the conclusion arrived in ARPES
experiments that the fermi-surface, suitably defined, has the shape of four
arcs which shrink to four points as $T \to 0$. Experiments, including infrared
absorption in a magnetic field, are suggested to distinguish between such a
state from that obtained by the conventional interpretation of the
magneto-oscillations.


title: Signatures of non-classicality in mixed-state quantum computation

abstract:
  We investigate signatures of non-classicality in quantum states, in
particular, those involved in the DQC1 model of mixed-state quantum computation
[Phys. Rev. Lett. 81, 5672 (1998)]. To do so, we consider two known
non-classicality criteria. The first quantifies disturbance of a quantum state
under locally noneffective unitary operations (LNU), which are local unitaries
acting invariantly on a subsystem. The second quantifies measurement induced
disturbance (MID) in the eigenbasis of the reduced density matrices. We study
the role of both figures of non-classicality in the exponential speedup of the
DQC1 model and compare them vis-a-vis the interpretation provided in terms of
quantum discord. In particular, we prove that a non-zero quantum discord
implies a non-zero shift under LNUs. We also use the MID measure to study the
locking of classical correlations [Phys. Rev. Lett. 92, 067902 (2004)] using
two mutually unbiased bases (MUB). We find the MID measure to exactly
correspond to the number of locked bits of correlation. For three or more MUBs,
it predicts the possibility of superior locking effects.


title:
A new determination of the orbit and masses of the Be binary system
  delta Scorpii

abstract:
  The binary star delta Sco (HD143275) underwent remarkable brightening in the
visible in 2000, and continues to be irregularly variable. The system was
observed with the Sydney University Stellar Interferometer (SUSI) in 1999,
2000, 2001, 2006 and 2007. The 1999 observations were consistent with
predictions based on the previously published orbital elements. The subsequent
observations can only be explained by assuming that an optically bright
emission region with an angular size of > 2 +/- 1 mas formed around the primary
in 2000. By 2006/2007 the size of this region grew to an estimated > 4 mas.
  We have determined a consistent set of orbital elements by simultaneously
fitting all the published interferometric and spectroscopic data as well as the
SUSI data reported here. The resulting elements and the brightness ratio for
the system measured prior to the outburst in 2000 have been used to estimate
the masses of the components. We find Ma = 15 +/- 7 Msun and Mb = 8.0 +/- 3.6
Msun. The dynamical parallax is estimated to be 7.03 +/- 0.15 mas, which is in
good agreement with the revised HIPPARCOS parallax.


title: On the mechanisms of heavy-quarkonium hadroproduction

abstract:
  We discuss the various mechanisms potentially at work in hadroproduction of
heavy quarkonia in the light of computations of higher-order QCD corrections
both in the Colour-Singlet (CS) and Colour-Octet (CO) channels and the
inclusion of the contribution arising from the s-channel cut in the CS channel.
We also discuss new observables meant to better discriminate between these
different mechanisms.


title:
Lyapunov spectra in fast dynamo Ricci flows of negative sectional
  curvature

abstract:
  Previously Chicone, Latushkin and Montgomery-Smith [\textbf{Comm. Math. Phys.
\textbf{173},(1995)}] have investigated the spectrum of the dynamo operator for
an ideally conducting fluid. More recently, Tang and Boozer [{\textbf{Phys.
Plasmas (2000)}}], have investigated the anisotropies in magnetic field dynamo
evolution, from finite-time, Lyapunov exponents, giving rise to a Riemann
metric tensor, in the Alfven twist in magnetic flux tubes (MFTs). In this paper
one investigate the role of Perelman Ricci flows constraints in twisted
magnetic flux tubes, where the Lyapunov eigenvalue spectra for the Ricci tensor
associated with the Ricci flow equation in MFTs leads to a finite-time Lyapunov
exponential stretching along the toroidal direction of the tube and a
contraction along the radial direction of the tube. It is shown that in the
case of MFTs, the sectional Ricci curvature of the flow, is negative as happens
in geodesic flows of Anosov type. Ricci flows constraints in MFTs substitute
the Thiffeault and Boozer [\textbf{Chaos}(2001)] have vanishing of Riemann
curvature constraint on the Lyapunov exponential stretching of chaotic flows.
Gauss curvature of the twisted MFT is also computed and the contraints on a
negative Gauss curvature are obtained.


title:
The Simultaneous Membership Problem for Chordal, Comparability and
  Permutation graphs

abstract:
  In this paper we introduce the 'simultaneous membership problem', defined for
any graph class C characterized in terms of representations, e.g. any class of
intersection graphs. Two graphs G_1 and G_2, sharing some vertices X (and the
corresponding induced edges), are said to be 'simultaneous members' of graph
class C, if there exist representations R_1 and R_2 of G_1 and G_2 that are
"consistent" on X. Equivalently (for the classes C that we consider) there
exist edges E' between G_1-X and G_2-X such that G_1 \cup G_2 \cup E' belongs
to class C.
  Simultaneous membership problems have application in any situation where it
is desirable to consistently represent two related graphs, for example:
interval graphs capturing overlaps of DNA fragments of two similar organisms;
or graphs connected in time, where one is an updated version of the other.
Simultaneous membership problems are related to simultaneous planar embeddings,
graph sandwich problems and probe graph recognition problems.
  In this paper we give efficient algorithms for the simultaneous membership
problem on chordal, comparability and permutation graphs. These results imply
that graph sandwich problems for the above classes are tractable for an
interesting special case: when the set of optional edges form a complete
bipartite graph. Our results complement the recent polynomial time recognition
algorithms for probe chordal, comparability, and permutation graphs, where the
set of optional edges form a clique.


title:
Analytic Spectra of CMB Anisotropies and Polarization Generated by Relic
  Gravitational Waves with Modification due to Neutrino Free-Streaming

abstract:
  We present an analytical calculation of the spectra of CMB anisotropies and
polarizations generated by relic gravitational waves (RGWs). As a substantial
extension to the previous studies, three new ingredients are included in this
work. Firstly, the analytic $C_l^{TT}$ and $C_l^{TE}$ are given; especially the
latter can be useful to extract signal of RGWs from the observed data in the
zero multipole method. Secondly, a fitting formula of the decaying factor on
small scales is given, coming from the visibility function around the photon
decoupling. Thirdly, the impacts by the neutrino free-streaming (NFS) is
examined, a process that occurred in the early universe and leaves observable
imprints on CMB via RGWs.
  It is found that the analytic $C_l^{TT}$ and $C_l^{TE}$ have profiles
agreeing with the numeric ones, except that $C^{TT}_l$ in a range $l \le 10$
and the $1^{st}$ trough of $C_l^{TE}$ around $l \sim 75$ have some deviations.
With the new damping factor, the analytic $C^{EE}_l$ and $C^{BB}_l$ match with
the numeric ones with the maximum errors only $\sim 3%$ up to the first three
peaks for $l\le 600$, improving the previous studies substantially. The
correspondence of the positions of peaks of $C^{XX}_l$ and those of RGWs are
also demonstrated explicitly. We also find that NFS reduces the amplitudes of
$C^{XX}_l$ by $(20% \sim 35%)$ for $l\simeq(100\sim 600)$ and shifts slightly
their peaks to smaller angles. Detailed analyses show that the zero multipoles
$l_0$, where $C_l^{TE}$ crosses 0, are shifted to larger values by NFS. This
shifting effect is as important as those causedby different inflation models
and different baryon fractions.


title: Stability analysis of kinked DNA in WLRC model

abstract:
  This paper has been withdrawn by the author due to a new work in
[arXiv:0901.0456v4] which can contain the results in this paper.


title: Lifetime measurements of the 5d states of rubidium

abstract:
  We present lifetime measurements of the $5D_{3/2}$ and $5D_{5/2}$ states of
rubidium using the time correlated single photon counting method. We perform
the experiment in a magneto-optical trap of $^{87}$Rb atoms using a two-step
excitation with the trap laser at 780 nm as the first step. We record the 761.9
nm fluorescence from the decay of the $5D_{3/2}$ state to the $5P_{1/2}$ state,
and measure the lifetime of the $5D_{3/2}$ state $\tau=246.3(1.6)$ ns. We
record the 420.2 nm fluorescence from the cascade decay of the $5D_{5/2}$ state
to the $5S_{1/2}$ state through the $6P_{3/2}$ state, and extract the lifetime
of the $5D_{5/2}$ state ${\tau}=238.5(2.3)$ ns.


title:
Electrical Resistivity and Thermal Expansion Measurements of URu2Si2
  under Pressure

abstract:
  We carried out simultaneous measurements of electrical resistivity and
thermal expansion of the heavy-fermion compound URu2Si2 under pressure using a
single crystal. We observed a phase transition anomaly between hidden (HO) and
antiferromagnetic (AFM) ordered states at TM in the temperature dependence of
both measurements. For the electrical resistivity, the anomaly at TM was very
small compared with the distinct hump anomaly at the phase transition
temperature T0 between the paramagnetic state (PM) and HO, and exhibited only a
slight increase and decrease for the I // a-axis and c-axis, respectively. We
estimated each excitation gap of HO, Delta_HO, and AFM, Delta_AFM, from the
temperature dependence of electrical resistivity; Delta_HO and Delta_AFM have
different pressure dependences from each other. On the other hand, the
temperature dependence of thermal expansion exhibited a small anomaly at T0 and
a large anomaly at TM. The pressure dependence of the phase boundaries of T0
and TM indicates that there is no critical end point and the two phase
boundaries meet at the critical point.


title:
Application of introduced nano-diamonds for the study of carbon
  condensation during detonation of high explosives

abstract:
  This paper describes the experimental studies of the formation of
nano-diamonds during detonation of TNT/RDX 50/50 mixture with small-angle x-ray
scattering (SAXS) method at a synchrotron radiation beam on VEPP-3 accelerator.
  A new experimental method with introduction of nano-diamonds into the
explosive has been applied. Inclusion of the diamonds obtained after detonation
into the TNT and RDX explosives allows modelling of the case of instant
creation of nano-diamonds during detonation.


title: How Homophily Affects Diffusion and Learning in Networks

abstract:
  We examine how three different communication processes operating through
social networks are affected by homophily -- the tendency of individuals to
associate with others similar to themselves. Homophily has no effect if
messages are broadcast or sent via shortest paths; only connection density
matters. In contrast, homophily substantially slows learning based on repeated
averaging of neighbors' information and Markovian diffusion processes such as
the Google random surfer model. Indeed, the latter processes are strongly
affected by homophily but completely independent of connection density,
provided this density exceeds a low threshold. We obtain these results by
establishing new results on the spectra of large random graphs and relating the
spectra to homophily. We conclude by checking the theoretical predictions using
observed high school friendship networks from the Adolescent Health dataset.


title:
Transport in molecular states language: Generalized quantum master
  equation approach

abstract:
  A simple scheme capable of treating transport in molecular junctions in the
language of many-body states is presented. An ansatz in Liouville space similar
to generalized Kadanoff-Baym approximation is introduced in order to reduce
exact equation-of-motion for Hubbard operator to quantum master equation
(QME)-like expression. A dressing with effective Liouville space propagation
similar to standard diagrammatic dressing approach is proposed. The scheme is
compared to standard QME approach, and its applicability to transport
calculations is discussed within numerical examples.


title:
Mechanism of Lattice-Distortion-Induced Electric-Polarization Flop in
  the Multiferroic Perovskite Manganites

abstract:
  Magnetoelectric phase diagrams of the perovskite manganites, Eu1-xYxMnO3 and
Gd1-xTbxMnO3, are theoretically studied. We first construct a microscopic
model, and then analyze the model using the Monte-Carlo method. We reproduce
the diagrams, which contain two different multiferroic states, i.e., the
ab-plane spin cycloid with electric polarization P//a and the bc-plane spin
cycloid with P//c. We reveal that their competition originates from a conflict
between the single-ion anisotropy and the Dzyaloshinsky-Moriya interaction,
which is controlled by the second-neighbor spin exchanges enhanced by the
GdFeO3-type distortion. This leads to a P flop from a to c with increasing x in
agreement with the experiments.


title:
Solutions of the (2+1)-dimensional KP, SK and KK equations generated by
  gauge transformations from non-zero seeds

abstract:
  By using gauge transformations, we manage to obtain new solutions of
(2+1)-dimensional Kadomtsev-Petviashvili(KP), Kaup-Kuperschmidt(KK) and
Sawada-Kotera(SK) equations from non-zero seeds. For each of the preceding
equations, a Galilean type transformation between these solutions $u_2$ and the
previously known solutions $u_2^{\prime}$ generated from zero seed is given. We
present several explicit formulas of the single-soliton solutions for $u_2$ and
$u_2^{\prime}$, and further point out the two main differences of them under
the same value of parameters, i.e., height and location of peak line, which are
demonstrated visibly in three figures.


title:
Exciton-photon interaction in a quantum dot embedded in a photonic
  microcavity

abstract:
  We present a detailed analysis of exciton-photon interaction in a microcavity
made out of a photonic crystal slab. Here we have analyzed a disk-like quantum
dot where an exciton is formed. Excitonic eigen-functions in addition to their
eigen-energies are found through direct matrix diagonalization, while wave
functions corresponding to unbound electron and hole are chosen as the basis
set for this procedure. In order to evaluate these wave functions precisely, we
have used Luttinger Hamiltonian in the case of hole while ignoring bands
adjacent to conduction band for electron states. After analyzing Excitonic
states, a photonic crystal based microcavity with a relatively high quality
factor mode has been proposed and its lattice constant has been adjusted to
obtain the prescribed resonant frequency. We use finite-difference time-domain
method in order to simulate our cavity with sufficient precision. Finally, we
formulate the coupling constants for exciton-photon interaction both where
intra-band and inter-band transitions occur. By evaluating a sample coupling
constant, it has been shown that the system can be in strong coupling regime
and Rabi oscillations can occur for Excitonic state population.


title:
Dynamics of OH(2Pi)-He collisions in combined electric and magnetic
  fields

abstract:
  We use accurate quantum mechanical calculations to analyze the effects of
parallel electric and magnetic fields on collision dynamics of OH(2Pi)
molecules. It is demonstrated that spin relaxation in 3He-OH collisions at
temperatures below 0.01 K can be effectively suppressed by moderate electric
fields of order 10 kV/cm. We show that electric fields can be used to
manipulate Feshbach resonances in collisions of cold molecules. Our results can
be verified in experiments with OH molecules in Stark decelerated molecular
beams and electromagnetic traps.


title: Current status of the LHCf experiment

abstract:
  An important experiment for cosmic ray physics is going to be conducted with
the colliding proton beams of the CERN LHC. The equivalent energy of the 14 TeV
center of mass energy of the colliding proton beams in the LHC is 1017eV in the
laboratory frame. Two small electromagnetic calorimeters have been installed at
zero degree collision angle +/-140m from the interaction point IP1. The
calorimeters measure the energies and the positions of the axes of showers
produced by forward neutral particles created in the proton-proton collisions.
The shower calorimeters are therefore able to measure the production
cross-section of neutral pions emitted in the very forward region. The
experimental results will be obtained during the early operation phase of LHC
when the luminosity is below 1030cm-2s-1. The data obtained will be extremely
important for benchmarking the various Monte Carlo codes used for interpreting
super high energy cosmic ray phenomena.


title: Equations of Motion in General Relativity of a Small Charged Black Hole

abstract:
  We present the details of a model in general relativity of a small charged
black hole moving in an external gravitational and electromagnetic field. The
importance of our model lies in the fact that we can derive the equations of
motion of the black hole from the Einstein-Maxwell vacuum field equations
without encountering infinities. The key assumptions which we base our results
upon are that (a) the black hole is isolated and (b) near the black hole the
wave fronts of the radiation generated by its motion are smoothly deformed
spheres. The equations of motion which emerge fit the pattern of the original
DeWitt and Brehme equations of motion (after they "renormalise"). Our
calculations are carried out in a coordinate system in which the null
hypersurface histories of the wave fronts can be specified in a simple way,
with the result that we obtain a new explicit form, particular to our model,
for the well-known "tail term" in the equations of motion.


title:
Effect of changing data size on eigenvalues in the Korean and Japanese
  stock markets

abstract:
  In this study, we attempted to determine how eigenvalues change, according to
random matrix theory (RMT), in stock market data as the number of stocks
comprising the correlation matrix changes. Specifically, we tested for changes
in the eigenvalue properties as a function of the number and type of stocks in
the correlation matrix. We determined that the value of the eigenvalue
increases in proportion with the number of stocks. Furthermore, we noted that
the largest eigenvalue maintains its identical properties, regardless of the
number and type, whereas other eigenvalues evidence different features.


title: Asymptotic results for bifurcations in pure bending of rubber blocks

abstract:
  The bifurcation of an incompressible neo-Hookean thick block with a ratio of
thickness to length {eta}, subject to pure bending, is considered. The two
incremental equilibrium equations corresponding to a nonlinear pre-buckling
state of strain are reduced to a fourth-order linear eigenproblem that displays
a multiple turning point. It is found that for 0 < {eta} < {infty}, the block
experiences an Euler-type buckling instability which in the limit {eta} ->
{infty} degenerates into a surface instability. Singular perturbation methods
enable us to capture this transition, while direct numerical simulations
corroborate the analytical results.


title:
Effective Actions from Loop Quantum Cosmology: Correspondence with
  Higher Curvature Gravity

abstract:
  Quantum corrections of certain types and relevant in certain regimes can be
summarised in terms of an effective action calculable, in principle, from the
underlying theory. The demands of symmetries, local form of terms and
dimensional considerations limit the form of the effective action to a great
extent leaving only the numerical coefficients to distinguish different
underlying theories. The effective action can be restricted to particular
symmetry sectors to obtain the corresponding, {\em reduced effective action}.
Alternatively, one can also quantize a classically (symmetry) reduced theory
and obtain the corresponding effective action. These two effective actions can
be compared. As an example, we compare the effective action(s) known in
isotropic loop quantum cosmology with the Lovelock actions, as well as with
more general actions, specialized to homogeneous isotropic space-times and find
that the $\bar{\mu}$-scheme is singled out.


title: Large-amplitude Love waves

abstract:
  In the context of the finite elasticity theory, we consider a model for
compressible solids called 'compressible neo-Hookean material'. We show how
finite-amplitude inhomogeneous plane wave solutions and finite-amplitude
unattenuated solutions can combine to form a finite-amplitude Love wave. We
take a layer of finite thickness overlying a solid half-space, both made of
different prestressed compressible neo-Hookean materials. We derive an exact
solution of the equations of motion and boundary conditions and also obtain
results for the energy density and the energy flux of the waves. Finally, we
investigate the special case when the interface between the layer and the
substrate is in a principal plane of the prestrain. A numerical example is
given.


title: VE-cadherin and claudin-5: it takes two to tango

abstract:
  Endothelial barrier function requires the adhesive activity of VE-cadherin
and claudin-5, which are key components of adherens and tight endothelial
junctions, respectively. Emerging evidence suggests that VE-cadherin controls
claudin-5 expression by preventing the nuclear accumulation of FoxO1 and
-catenin, which repress the claudin-5 promoter. This indicates that a crosstalk
mechanism operates between these junctional structures.


title:
Addendum to Reconciling Grand Unification with Strings by Anisotropic
  Compactifications

abstract:
  In a recent paper, by working in the orbifold GUT limit of the Heterotic
string, we showed how one could accommodate gauge coupling unification in the
"mini-landscape" models of Lebedev et al. Furthermore, it was shown how one of
the solutions was consistent with the decoupling of other exotics with F=0. In
this short addendum, we show that this solution is also consistent with D=0.


title:
Bi-orthogonal systems on the unit circle, Regular Semi-Classical Weights
  and Integrable Systems - II

abstract:
  We derive the Christoffel-Geronimus-Uvarov transformations of a system of
bi-orthogonal polynomials and associated functions on the unit circle, that is
to say the modification of the system corresponding to a rational modification
of the weight function. In the specialisation of the weight function to the
regular semi-classical case with an arbitrary number of regular singularities $
\{z_1, ..., z_M \} $ the bi-orthogonal system is known to be isomonodromy
preserving with respect to deformations of the singular points. If the zeros
and poles of the Christoffel-Geronimus-Uvarov factors coincide with the
singularities then we have the Schlesinger transformations of this
isomonodromic system. Compatibility of the Schlesinger transformations with the
other structures of the system - the recurrence relations, the spectral
derivatives and deformation derivatives is explicitly deduced. Various forms of
Hirota-Miwa equations are derived for the $ \tau $-functions or equivalently
Toeplitz determinants of the system.


title:
Non-singular solutions of normalized Ricci flow on noncompact manifolds
  of finite volume

abstract:
  The main result of this paper shows that, if $g(t)$ is a complete
non-singular solution of the normalized Ricci flow on a noncompact 4-manifold
$M$ of finite volume, then the Euler characteristic number $\chi(M)\geq0$.
Moreover, $\chi(M)\neq 0$, there exist a sequence times $t_k\to\infty$, a
double sequence of points $\{p_{k,l}\}_{l=1}^{N}$ and domains
$\{U_{k,l}\}_{l=1}^{N}$ with $p_{k,l}\in U_{k,l}$ satisfying the followings:
  [(i)] $\dist_{g(t_k)}(p_{k,l_1},p_{k,l_2})\to\infty$ as $k\to\infty$, for any
fixed $l_1\neq l_2$; [(ii)] for each $l$, $(U_{k,l},g(t_k),p_{k,l})$ converges
in the $C_{loc}^\infty$ sense to a complete negative Einstein manifold
$(M_{\infty,l},g_{\infty,l},p_{\infty,l})$ when $k\to\infty$; [(iii)]
$\Vol_{g(t_{k})}(M\backslash\bigcup_{l=1}^{N}U_{k,l})\to0$ as $k\to\infty$.


title: Indecomposable polynomials and their spectrum

abstract:
  We address some questions concerning indecomposable polynomials and their
spectrum. How does the spectrum behave via reduction or specialization, or via
a more general ring morphism? Are the indecomposability properties equivalent
over a field and over its algebraic closure? How many polynomials are
decomposable over a finite field?


title:
Analytical Framework for Optimizing Weighted Average Download Time in
  Peer-to-Peer Networks

abstract:
  This paper proposes an analytical framework for peer-to-peer (P2P) networks
and introduces schemes for building P2P networks to approach the minimum
weighted average download time (WADT). In the considered P2P framework, the
server, which has the information of all the download bandwidths and upload
bandwidths of the peers, minimizes the weighted average download time by
determining the optimal transmission rate from the server to the peers and from
the peers to the other peers. This paper first defines the static P2P network,
the hierarchical P2P network and the strictly hierarchical P2P network. Any
static P2P network can be decomposed into an equivalent network of sub-peers
that is strictly hierarchical. This paper shows that convex optimization can
minimize the WADT for P2P networks by equivalently minimizing the WADT for
strictly hierarchical networks of sub-peers. This paper then gives an upper
bound for minimizing WADT by constructing a hierarchical P2P network, and lower
bound by weakening the constraints of the convex problem. Both the upper bound
and the lower bound are very tight. This paper also provides several suboptimal
solutions for minimizing the WADT for strictly hierarchical networks, in which
peer selection algorithms and chunk selection algorithm can be locally
designed.


title: Casimir densities in brane models with compact internal spaces

abstract:
  We investigate the Wightman function, the vacuum expectation values of the
field squared and the energy-momentum tensor for a massive scalar field with
general curvature coupling parameter subject to Robin boundary conditions on
two codimension one parallel branes located on $(D+1)$-dimensional background
spacetime $AdS_{D_{1}+1}\times \Sigma $ with a warped internal space $\Sigma $.
The general case of different Robin coefficients on separate branes is
considered. Unlike to the purely AdS bulk, the vacuum expectation values
induced by a single brane, in addition to the distance from the brane, depends
also on the position of the brane in the bulk. The brane induced parts in these
expectation values vanish when the brane position tends to the AdS horizon or
AdS boundary. For strong gravitational fields corresponding to large values of
the AdS energy scale, the both single brane and interference parts of the
expectation values integrated over the internal space are exponentially
suppressed. An application to the higher dimensional generalization of the
Randall-Sundrum brane model with arbitrary mass terms on the branes is
discussed. For large distances between the branes the induced surface densities
give rise to an exponentially suppressed cosmological constant on the brane.


title:
Extending $T^p$ automorphisms over $\RR^{p+2}$ and realizing DE
  attractors

abstract:
  In this paper we consider the realization of DE attractors by
self-diffeomorphisms of manifolds. For any expanding self-map $\phi:M\to M$ of
a connected, closed $p$-dimensional manifold $M$, one can always realize a
$(p,q)$-type attractor derived from $\phi$ by a compactly-supported
self-diffeomorphsm of $\RR^{p+q}$, as long as $q\geq p+1$. Thus lower
codimensional realizations are more interesting, related to the knotting
problem below the stable range. We show that for any expanding self-map $\phi$
of a standard smooth $p$-dimensional torus $T^p$, there is compactly-supported
self-diffeomorphism of $\RR^{p+2}$ realizing an attractor derived from $\phi$.
A key ingredient of the construction is to understand automorphisms of $T^p$
which extend over $\RR^{p+2}$ as a self-diffeomorphism via the standard
unknotted embedding $\imath_p:T^p\hookrightarrow\RR^{p+2}$. We show that these
automorphisms form a subgroup $E_{\imath_p}$ of $\Aut(T^p)$ of index at most
$2^p-1$.


title:
Computation of Grobner basis for systematic encoding of generalized
  quasi-cyclic codes

abstract:
  Generalized quasi-cyclic (GQC) codes form a wide and useful class of linear
codes that includes thoroughly quasi-cyclic codes, finite geometry (FG) low
density parity check (LDPC) codes, and Hermitian codes. Although it is known
that the systematic encoding of GQC codes is equivalent to the division
algorithm in the theory of Grobner basis of modules, there has been no
algorithm that computes Grobner basis for all types of GQC codes. In this
paper, we propose two algorithms to compute Grobner basis for GQC codes from
their parity check matrices: echelon canonical form algorithm and transpose
algorithm. Both algorithms require sufficiently small number of finite-field
operations with the order of the third power of code-length. Each algorithm has
its own characteristic; the first algorithm is composed of elementary methods,
and the second algorithm is based on a novel formula and is faster than the
first one for high-rate codes. Moreover, we show that a serial-in serial-out
encoder architecture for FG LDPC codes is composed of linear feedback shift
registers with the size of the linear order of code-length; to encode a binary
codeword of length n, it takes less than 2n adder and 2n memory elements.
Keywords: automorphism group, Buchberger's algorithm, division algorithm,
circulant matrix, finite geometry low density parity check (LDPC) codes.


title:
Analysis and calibration of absorptive images of Bose-Einstein
  condensate at non-zero temperatures

abstract:
  We describe the method allowing quantitative interpretation of absorptive
images of mixtures of BEC and thermal atoms which reduces possible systematic
errors associated with evaluation of the contribution of each fraction. By
using known temperature dependence of the BEC fraction, the analysis allows
precise calibration of the fitting results. The developed method is verified in
two different measurements and compares well with theoretical calculations and
with measurements performed by another group.


title:
A New Diagnostic Method for Assessment of Stellar Stratification in Star
  Clusters

abstract:
  We propose a new method for the characterization of stellar stratification in
stellar systems. The method uses the mean-square radius (also called the
Spitzer radius) of the system as a diagnostic tool. An estimate of the
observable counterpart of this radius for stars of different magnitude ranges
is used as the effective radius of each stellar species in a star cluster. We
explore the dependence of these radii on magnitude as a possible indication of
stellar stratification. This method is the first of its kind to use a
dynamically stable radius, and though seemingly trivial it has never been
applied before. We test the proposed method using model star clusters, which
are constructed to be segregated on the basis of a Monte Carlo technique, and
on Hubble Space Telescope observations of mass-segregated star clusters in
order to explore the limitations of the method in relation to actual data. We
conclude that the method performs efficiently in the detection of stellar
stratification and its results do not depend on the data, provided that
incompleteness has been accurately measured and the contamination by the field
population has been thoroughly removed. Our diagnosis method is also
independent of any model or theoretical prediction, in contrast to the
`classical' methods used so far for the detection of mass segregation.


title:
Protein Kinase C-related Kinase and ROCK Are Required for
  Thrombin-induced Endothelial Cell Permeability Downstream from G{alpha}12/13
  and G{alpha}11/q

abstract:
  Increase in vascular permeability occurs under many physiological conditions
and is central in diverse human pathologies. Thrombin is a pro-coagulant serine
protease, which causes the local loss of endothelial barrier integrity thereby
enabling the rapid extravasation of plasma proteins and the local formation of
fibrin-containing clots. Available information suggests that thrombin induces
endothelial permeability by promoting actomyosin contractility through the
Rho/ROCK signaling pathway. Here we took advantage of pharmacological
inhibitors, knockdown approaches, and the emerging knowledge on how
permeability factors affect endothelial junctions to investigate in detail the
mechanism underlying thrombin-induced endothelial permeability. We show that
thrombin signals through PAR-1 and its coupled G proteins G(12/13) and G(11/q)
to induce RhoA activation and intracellular calcium elevation, and that these
events are interrelated. In turn, this leads to the stimulation of ROCK, which
causes actin stress-fiber formation. However, this alone is not sufficient to
account for thrombin-induced permeability. Instead, we found that protein
kinase C-related kinase, a Rho-dependent S/T kinase, is activated in
endothelial cells upon thrombin stimulation and that its expression is required
for endothelial permeability and remodeling of cell-extracellular matrix and
cell-cell adhesions. Our results demonstrate that the signal initiated by
thrombin bifurcates at the level of RhoA to promote changes in the cytoskeletal
architecture through ROCK and the remodeling of focal adhesion components
through PRK. Ultimately, both pathways converge to cause cell-cell junction
disruption and provoke vascular leakage.


title: Non-Fermi-liquid effect in magnetic susceptibility

abstract:
  Taking into account the anomalous self-energy for quarks due to the dynamic
screening effect for the transverse gluon propagator, we study the temperature
dependence of the magnetic susceptibility in detail. It is shown that there
does not exist the $T\ln T$ term in the susceptibility, different from the
specific heat, but an anomalous $T^2\ln T$ term arises instead as a novel
non-Fermi-liquid effect.


title: Application of the X-ray laser to muon-catalyzed d-t fusion

abstract:
  We discuss the alpha-muon sticking coefficient in the muon-catalysed d-t
fusion in the framework of the Constrained Molecular Dynamics model. Especially
the influence of muonic chaotic dynamics on the sticking coefficient is brought
into focus. The chaotic motion of the muon affects not only the fusion cross
section but also the muon-alpha sticking coefficient. Chaotic systems lead to
lar ger enhancements with respect to regular systems because of the reduction
of the tunneling region. Moreover they give smaller sticking probabilities than
those of regular events. By utilizing a characteristic of the chaotic dynamics
one can avoid losing the muon in the muCF cycle. W e propose that the
application of the so-called microwave ionization of a Rydberg atom to the
present case could lead to the enhancement of the reactivation process by using
X-rays.


title:
Hedging of Defaultable Contingent Claims using BSDE with uncertain time
  horizon

abstract:
  This article focuses on the mathematical problem of existence and uniqueness
of BSDE with a random terminal time which is a general random variable but not
a stopping time, as it has been usually the case in the previous literature of
BSDE with random terminal time. The main motivation of this work is a financial
or actuarial problem of hedging of defaultable contingent claims or life
insurance contracts, for which the terminal time is a default time or a death
time, which are not stopping times. We have to use progressive enlargement of
the Brownian filtration, and to solve the obtained BSDE under this enlarged
filtration. This work gives a solution to the mathematical problem and proves
the existence and uniqueness of solutions of such BSDE under certain general
conditions. This approach is applied to the financial problem of hedging of
defaultable contingent claims, and an expression of the hedging strategy is
given for a defaultable contingent claim or a life insurance contract.


title:
ELASTICITY: Topological Characterization of Robustness in Complex
  Networks

abstract:
  Just as a herd of animals relies on its robust social structure to survive in
the wild, similarly robustness is a crucial characteristic for the survival of
a complex network under attack. The capacity to measure robustness in complex
networks defines the resolve of a network to maintain functionality in the
advent of classical component failures and at the onset of cryptic malicious
attacks. To date, robustness metrics are deficient and unfortunately the
following dilemmas exist: accurate models necessitate complex analysis while
conversely, simple models lack applicability to our definition of robustness.
In this paper, we define robustness and present a novel metric, elasticity- a
bridge between accuracy and complexity-a link in the chain of network
robustness. Additionally, we explore the performance of elasticity on Internet
topologies and online social networks, and articulate results.


title:
Stellar mass estimates in early-type galaxies: procedures, uncertainties
  and models dependence

abstract:
  The aim of the present paper is to quantify the dependence of the estimates
of luminosities and stellar mass of early-type galaxies on the different models
and model parameters which can be used to analyze the observational data. The
paper is organized in two parts. The first one analyzes the dependence of the
M/L ratios and of the k-corrections in different bands on model parameters
(IMF, metallicity, star formation history, age), assuming some among the most
popular spectrophotometric codes usually adopted to study the evolutionary
status of galaxies [...]. The second part of our work is dedicated to quantify
the reliability and systematics affecting the mass and luminosity estimates
obtained by means of the best fitting technique applied to the photometric SEDs
of early-type galaxies at $1<z<2$. To this end, we apply the best fitting
technique to some mock catalogs built on the basis of a wide set of models of
early-type galaxies. We then compare the luminosity and the stellar mass
estimated from the SED fitting with the true known input values. The goodness
of the mass estimate is found to be dependent on the mass estimator adopted to
derive it, but masses cannot anyhow be retrieved better than within a factor
2-3, depending on the quality of the available photometric data and/or on the
distance of the galaxies since more distant galaxies are fainter on average and
thus affected by larger photometric errors. Finally, we present a new empirical
mass estimator based on the K band apparent magnitude and on the observed (V-K)
colour. We show that the reliability of the stellar mass content derived with
this new estimator for early-type galaxies and its stability are even higher
than those achievable with the best classic estimators, with the not negligible
advantage that it does not need any multi-wavelength data fitting.


title: Electronic theory of ultrafast spin dynamics

abstract:
  NiO is a good candidate for ultrafast magnetic switching because of its large
spin density, antiferromagnetic order, and clearly separated intragap states.
In order to detect and monitor the switching dynamics, we develop a systematic
approach to study optical second harmonic generation (SHG) in NiO, both at the
(001) surface and in the bulk. In our calculations NiO is modeled as a doubly
embedded cluster. All intragap \emph{d}-states of the bulk and the (001)
surface are obtained with highly-correlational quantum chemistry and propagated
in time under the influence of a static magnetic field and a laser pulse. We
find that demagnetization and switching can be best achieved in a subpicosecond
regime with linearly rather than circularly polarized light. We also show the
importance of including an external magnetic field in order to distinguish
spin-up and spin-down states and the necessity of including magnetic-dipole
transitions in order to realize the $\Lambda$-process in the centrosymmetric
bulk. Having already shown the effects of phonons in the SHG for the bulk NiO
within the frozen-phonon approximation, and following the same trail of
thoughts, we discuss the role of phonons in a fully quantized picture as a
symmetry-lowering mechanism in the switching scenario and investigate the
electronic and lattice temperature effects.


title: Constraints on black hole accretion in V Puppis

abstract:
  In light of the recent suggestion that the nearby eclipsing binary star
system V Puppis has a dark companion on a long orbit, we present the results of
radio and X-ray observations of it. We find an upper limit on its radio flux of
about 300 $\mu$Jy and a detection of it in the X-rays with a luminosity of
about 3$\times10^{31}$ erg/sec, a value much lower than what had been observed
in some of the low angular resolution surveys of the past. These data are in
good agreement with the idea that the X-ray emission from V Puppis comes from
mass transfer between the two B stars in the system, but can still accommodate
the idea that the X-ray emission comes from the black hole accreting stellar
wind from one or both of the B stars.


title: M2-Branes and Quiver Chern-Simons: A Taxonomic Study

abstract:
  We initiate a systematic investigation of the space of 2+1 dimensional quiver
gauge theories, emphasising a succinct "forward algorithm". Few "order
parametres" are introduced such as the number of terms in the superpotential
and the number of gauge groups. Starting with two terms in the superpotential,
we find a generating function, with interesting geometric interpretation, which
counts the number of inequivalent theories for a given number of gauge groups
and fields. We demonstratively list these theories for some low numbers
thereof. Furthermore, we show how these theories arise from M2-branes probing
toric Calabi-Yau 4-folds by explicitly obtaining the toric data of the vacuum
moduli space. By observing equivalences of the vacua between markedly different
theories, we see a new emergence of "toric duality".


title: Two ~35 day clocks in Her X-1: evidence for neutron star free precession

abstract:
  We present evidence for the existence of two ~35 day clocks in the Her X-1/HZ
Her binary system. ~35 day modulations are observed 1) in the Turn-On cycles
with two on- and two off-states, and 2) in the changing shape of the pulse
profiles which re-appears regularly. The two ways of counting the 35 day cycles
are generally in synchronization. This synchronization did apparently break
down temporarily during the long Anomalous Low (AL3) which Her X-1 experienced
in 1999/2000, in the sense that there must have been one extra Turn-On cycle.
Our working hypothesis is that there are two clocks in the system, both with a
period of about ~35 days: precession of the accretion disk (the less stable
"Turn-On clock") and free precession of the neutron star (the more stable
"Pulse profile clock"). We suggest that free precession of the neutron star is
the master clock, and that the precession of the accretion disk is basically
synchronized to that of the neutron star through a feed-back mechanism in the
binary system. However, the Turn-On clock can slip against its master when the
accretion disk has a very low inclination, as is observed to be the case during
AL3. We take the apparent correlation between the histories of the Turn-Ons, of
the Anomalous Lows and of the pulse period evolution, with a 5 yr
quasi-periodicity, as evidence for strong physical interaction and feed-back
between the major components in the system. We speculate that the 5 yr (10 yr)
period is either due to a corresponding activity cycle of HZ Her or a natural
ringing period of the physical system of coupled components. The question
whether free precession really exists in neutron stars is of great importance
for the understanding of matter with supra-nuclear density.


title:
Entanglement purification protocol for a mixture of a pure entangled
  state and a pure product state

abstract:
  We present an entanglement purification protocol for a mixture of a pure
entangled state and a pure product state, which are orthogonal to each other.
The protocol is combination of bisection method and one-way hashing protocol.
We give recursive formula for the rate of the protocol for different states,
i.e. the number of maximally entangled two-qubit pairs obtained with the
protocol per a single copy of the initial state. We also calculate numerically
the rate for some states.


title:
Evidence for two distinct anisotropies in the oxypnictide
  superconductors SmFeAsO_(0.8)F_(0.2) and NdFeAsO_(0.8)F_(0.2)

abstract:
  Single crystals of the oxypnictide superconductors SmFeAsO_(0.8)F_(0.2) and
NdFeAsO_(0.8)F_(0.2) with T_c in the range of 44 K to 48 K were investigated by
torque magnetometry. An analysis of the data in terms of a recently proposed
model for the anisotropic magnetization in the superconducting state, treating
the penetration depth anisotropy differently than the upper critical field
anisotropy, provides evidence that in the oxypnictide superconductors two
distinct anisotropies are present. As a result the penetration depth anisotropy
differs significantly in magnitude and in temperature dependence from the upper
critical field anisotropy, analogous to MgB_2 but with a reversed sign of
slope. This scenario strongly suggests a new multi-band mechanism in the novel
class of oxypnictide high-temperature superconductors.


title:
Toward Perfection: Kapellasite, Cu3Zn(OH)6Cl2, a New Model S = 1/2
  Kagome Antiferromagnet

abstract:
  The search for the resonating valence bond (RVB) state continues to underpin
many areas of condensed matter research. The RVB is made from the dimerisation
of spins on different sites into fluctuating singlets, and was proposed by
Anderson to be the reference state from which the transition to BCS
superconductivity occurs. Little is known about the state experimentally, due
to the scarcity of model materials. Theoretical work has put forward the S =
1/2 kagome antiferromagnet (KAFM) as a good candidate for the realization of
the RVB state. In this paper we introduce a new model system, the S = 1/2 KAFM
Kapellasite, Cu3Zn(OH)6Cl2. We show that its crystal structure is a good
approximation to a 2-dimensional kagome antiferromagnet and that susceptibility
data indicate a collapse of the magnetic moment below T = 25 K that is
compatible with the spins condensing into the non-magnetic RVB state.


title:
Stability of Orbits around a Spinning Body in a Pseudo-Newtonian Hill
  Problem

abstract:
  A pseudo-Newtonian Hill problem based on a potential proposed by Artemova et
al. [Astroph. J. 461 (1996) 565] is presented. This potential reproduces some
of the general relativistic effects due to the spin angular momentum of the
bodies, like the dragging of inertial frames. Poincare maps, Lyapunov exponents
and fractal escape techniques are employed to study the stability of bounded
and unbounded orbits for different spins of the central body.


title: Resolved 24.5 micron emission from massive young stellar objects

abstract:
  Massive young stellar objects (MYSO) are surrounded by massive dusty
envelopes. Our aim is to establish their density structure on scales of ~1000
AU, i.e. a factor 10 increase in angular resolution compared to similar studies
performed in the (sub)mm. We have obtained diffraction-limited (0.6") 24.5
micron images of 14 well-known massive star formation regions with
Subaru/COMICS. The images reveal the presence of discrete MYSO sources which
are resolved on arcsecond scales. For many sources, radiative transfer models
are capable of satisfactorily reproducing the observations. They are described
by density powerlaw distributions (n(r) ~ r^(-p)) with p = 1.0 +/-0.25. Such
distributions are shallower than those found on larger scales probed with
single-dish (sub)mm studies. Other sources have density laws that are
shallower/steeper than p = 1.0 and there is evidence that these MYSOs are
viewed near edge-on or near face-on, respectively. The images also reveal a
diffuse component tracing somewhat larger scale structures, particularly
visible in the regions S140, AFGL 2136, IRAS 20126+4104, Mon R2, and Cep A. We
thus find a flattening of the MYSO envelope density law going from ~10 000 AU
down to scales of ~1000 AU. We propose that this may be evidence of rotational
support of the envelope (abridged).


title:
Coalescence of two exceptional points in the anti-hermitian 3-level
  pairing model

abstract:
  The formation of a higher-order singularity by the coalescence of two
exceptional points is studied in the anti-hermitian limit of the
complex-extended 3-level Richardson-Gaudin model.


title:
The search for a strategy for mankind to survive the solar Red Giant
  catastrophe

abstract:
  In around 5 gigayears our Sun will grow to a Red Giant and will swallow
Earth. The plan is subdivided into two parts: We propose to construct some kind
of parasol to shadow Earth. The position of the parasol will be the (inner)
Lagrange Point L1. If we want to survive also the time beyond the next 5 Gy,
where Suns luminosity and radius increase hundred fold and oscillate until our
Sun develops finally into a White Dwarf, we have to shift Earth into the Kuiper
Belt (50 AU) by means of the swing-by technique During this journey of about
some megayears or more Earth must be illuminated by an artificial light source.
A ring of DD-fusion power stations outstretched on Moons orbit should produce
the necessary 175 PW of visible light. In the Kuiper Belt Earth will be brought
into an orbit of an artificial Sun, an ArtSun formed in the meantime by the
fusion of gaseous Jupiter-like planets imported from other planetary systems in
the neighborhood


title: Nuclear electron capture rate in stellar interiors and the case of 7Be

abstract:
  Nuclear electron capture rate from continuum in an astrophysical plasma
environment (like solar core) is calculated using a modified Debye-Huckel
screening potential and the related non-Gaussian q-distribution of electron
momenta. For q=1 the well-known Debye-Huckel results are recovered. The value
of q can be derived from the fluctuation of number of particles and temperature
inside the Debye sphere. For 7Be continuum electron capture in solar core, we
find an increase of 7 -- 10 percent over the rate calculated with standard
Debye-Huckel potential. The consequence of this results is a reduction of the
same percentage of the SSM 8B solar neutrino flux, leaving unchanged the SSM
7Be flux.


title: Growth of fat slits and dispersionless KP hierarchy

abstract:
  A "fat slit" is a compact domain in the upper half plane bounded by a curve
with endpoints on the real axis and a segment of the real axis between them. We
consider conformal maps of the upper half plane to the exterior of a fat slit
parameterized by harmonic moments of the latter and show that they obey an
infinite set of Lax equations for the dispersionless KP hierarchy. Deformation
of a fat slit under changing a particular harmonic moment can be treated as a
growth process similar to the Laplacian growth of domains in the whole plane.
This construction extends the well known link between solutions to the
dispersionless KP hierarchy and conformal maps of slit domains in the upper
half plane and provides a new, large family of solutions.


title: An Alternative to Kaluza

abstract:
  In Kaluza derived theories the electromagnetic potential is interpreted as a
part of the metric in a higher dimensional theory of gravity. Here we present a
more Yang-Mills like unification of classical electromagnetism and gravity
within five dimensions, where the electromagnetic potential is related to the
connecion and the field strength to the curvature. In addition some aspects of
a quantum theory can be described in the context of the Gauss-Bonnet-Chern
Theorem. This approach offers new coupling mechanisms between gravity and
electromagnetism.


title: Rings and spirals in barred galaxies. I Building blocks

abstract:
  In this paper we present building blocks which can explain the formation and
properties both of spirals and of inner and outer rings in barred galaxies. We
first briefly summarise the main results of the full theoretical description we
have given elsewhere, presenting them in a more physical way, aimed to an
understanding without the requirement of extended knowledge of dynamical
systems or of orbital structure. We introduce in this manner the notion of
manifolds, which can be thought of as tubes guiding the orbits. The dynamics of
these manifolds can govern the properties of spirals and of inner and outer
rings in barred galaxies. We find that the bar strength affects how unstable
the L1 and L2 Lagrangian points are, the motion within the 5A5A5Amanifold tubes
and the time necessary for particles in a manifold to make a complete turn
around the galactic centre. We also show that the strength of the bar, or, to
be more precise, of the non-axisymmetric forcing at and somewhat beyond the
corotation region, determines the resulting morphology. Thus, less strong bars
give rise to R1 rings or pseudorings, while stronger bars drive R2, R1R2 and
spiral morphologies. We examine the morphology as a function of the main
parameters of the bar and present descriptive two dimensional plots to that
avail. We also derive how the manifold morphologies and properties are modified
if the L1 and L2 Lagrangian points become stable. Finally, we discuss how
dissipation affects the manifold properties and compare the manifolds in
gas-like and in stellar cases. Comparison with observations, as well as clear
predictions to be tested by observations will be given in an accompanying
paper.


title:
Gamma-rays from the vicinity of accreting neutron stars inside compact
  high-mass X-ray binaries

abstract:
  Dense wind of a massive star can be partially captured by a neutron star (NS)
inside a compact binary system. Depending on the parameters of NS and the wind,
the matter can penetrate the inner NS magnetosphere. At some distance from the
NS a very turbulent and magnetized transition region is formed due to the
balance between the magnetic pressure and the pressure inserted by accreting
matter. This region provides good conditions for acceleration of particles to
relativistic energies. The matter at the transition region can farther accrete
onto the NS surface (the accretor phase) or is expelled from the NS vicinity
(the propeller phase). We consider the consequences of acceleration of
electrons at the transition region concentrating on the situation in which at
least part of the matter falls onto the NS surface. This matter creates a hot
spot on the NS surface which emits thermal radiation. Relativistic electrons
lose energy on the synchrotron process and the inverse Compton (IC) scattering
of this thermal radiation. We calculate the synchrotron spectra (from X-rays to
soft $\gamma$-rays) and IC spectra (above a few tens MeV) expected in such a
scenario. It is argued that a population of recently discovered massive
binaries by the INTEGRAL observatory, which contain neutron stars hidden inside
dense stellar winds of massive stars, can be detectable by the recently
launched {\it Fermi} LAT telescope at GeV energy range. As an example, we
predict the expected $\gamma$-ray flux from recently discovered source IGR
J19140+0951.


title:
CI and CO in nearby galaxy centers: the bright galaxies NGC1068 (M77),
  NGC2146, NGC3079, NGC4826 (M64), and NGC7469

abstract:
  Maps and measurements of the J=1-0, J=2-1, J=3-2, J=4-3 12CO, the J=1-0,
J=2-1, and J=3-2 13CO lines in the central arcminute squared of NGC1068,
NGC2146, NGC3079, NGC4826, and NGC7469, as well as 492 GHz [CI] maps in three
of these are used to model the circumnuclear molecular gas in these galaxies.
In all five objects, the bright CO concentrations mapped have line intensities
that require two distinct gas components for satisfactory fits. The physical
condition of the molecular gas differs from galaxy to galaxy. High kinetic
temperatures of 125-150 K occur in NGC2146 and NGC3079. Very high densities of
0.3-1.0 x 10**5 cm**-3 occur in NGC2146, NGC3079, and NGC7469. The CO to H2
conversion factor X is typically an order of magnitude less than the `standard'
value in the Solar Neighborhood. The molecular gas is constrained within radii
between 0.9 and 1.5 kpc from the nuclei. Within these radii, H2 masses are
typically 1.2-2.5 x 10**8 M(sun). The exception is the (relatively nearby)
merger NGC4826 with R=0.3 kpc, and M = 3 x 10**7 M(sun). In all five galaxies,
the H2 mass is typically about one per cent of the dynamical mass in the same
region.


title: The asymptotic Schottky problem

abstract:
  Let $\mathcal M_g$ denote the moduli space of compact Riemann surfaces of
genus $g$ and let $\mathcal A_g$ be the space of principally polarized abelian
varieties of (complex) dimension $g$. Let $J:\mathcal M_g\longrightarrow
\mathcal A_g$ be the map which associates to a Riemann surface its Jacobian.
The map $J$ is injective, and the image $J(\mathcal M_g)$ is contained in a
proper subvariety of $\mathcal A_g$ when $g\geq 4$. The classical and
long-studied Schottky problem is to characterize the Jacobian locus $\mathcal
J_g:=J(\mathcal M_g)$ in $\mathcal A_g$. In this paper we adress a large scale
version of this problem posed by Farb and called the {\em coarse Schottky
problem}: How does $\mathcal J_g$ look "from far away", or how "dense" is
$\mathcal J_g$ in the sense of coarse geometry? The coarse geometry of the
Siegel modular variety $\mathcal A_g$ is encoded in its asymptotic cone
$\textup{Cone}_\infty(\mathcal A_g)$, which is a Euclidean simplicial cone of
(real) dimension $g$. Our main result asserts that the Jacobian locus $\mathcal
J_g$ is "asymptotically large", or "coarsely dense" in $\mathcal A_g$. More
precisely, the subset of $\textup{Cone}_\infty(\mathcal A_g)$ determinded by
$\mathcal J_g$ actually coincides with this cone. The proof also shows that the
Jacobian locus of hyperelliptic curves is coarsely dense in $\mathcal A_g$ as
well. We also study the boundary points of the Jacobian locus $\mathcal J_g$ in
$\mathcal A_g$ and in the Baily-Borel and the Borel-Serre compactification. We
show that for large genus $g$ the set of boundary points of $\mathcal J_g$ in
these compactifications is "small".


title: Features of exceptional points and the continuum spectroscopy

abstract:
  We discuss observable features of exceptional points and the resonance
spectroscopy of $^{16}$Ne using the Shell Model Embedded in the Continuum.


title: Benchmarking the solar dynamo with Maxima

abstract:
  Recently, Jouve et al(A&A, 2008) published the paper that presents the
numerical benchmark for the solar dynamo models. Here, I would like to show a
way how to get it with help of computer algebra system Maxima. This way was
used in our paper (Pipin & Seehafer, A&A 2008, in print) to test some new ideas
in the large-scale stellar dynamos. In the present paper I complement the
dynamo benchmark with the standard test that address the problem of the
free-decay modes in the sphere which is submerged in vacuum.


title:
The Duistermaat-Heckman formula and the cohomology of moduli spaces of
  polygons

abstract:
  We give a presentation of the cohomology ring of spatial polygon spaces
$M(r)$ with fixed side lengths $r \in \mathbb R^n_+$. These spaces can be
described as the symplectic reduction of the Grassmaniann of 2-planes in
$\mathbb C^n$ by the $U(1)^n$-action by multiplication, where $U(1)^n$ is the
torus of diagonal matrices in the unitary group U(n). We prove that the first
Chern classes of the $n$ line bundles associated with the fibration $r$-level
set $\rightarrow M(r)$ generate the cohomology ring $H^* (M(r), \mathbb C).$ By
applying the Duistermaat--Heckman Theorem, we then deduce the relations on
these generators from the piece-wise polynomial function that describes the
volume of $M(r).$ We also give an explicit description of the birational map
between $M(r) $ and $M(r')$ when the lengths vectors $r$ and $r'$ are in
different chambers of the moment polytope. This wall-crossing analysis is the
key step to prove that the Chern classes above are generators of $H^*(M(r))$
(this is well-known when $M(r)$ is toric, and by wall-crossing we prove that it
holds also when $M(r)$ is not toric).


title: Solutions of Aronsson equation near isolated points

abstract:
  We show that for non-negative solution of the Aronsson equation an isolated
singularity is either removable, or the solution behaves asymptotically like a
general cone. This generalizes the asymptotic behavior theory for infinity
harmonic functions by Savin, Wang and Yu.


title:
"Set-theoretical" solutions of the quantum Yang-Baxter equation and a
  class of Garside groups

abstract:
  We establish a one-to-one correspondence between structure groups of
non-degenerate, involutive and braided "set-theoretical" solutions of the
quantum Yang-Baxter equation and Garside groups with a certain presentation.
Moreover, we show that the solution is indecomposable if and only if its
structure group is a $\Delta-$pure Garside group.


title: High-Temperature Superconducting Level Meter for Liquid Argon Detectors

abstract:
  Capacitive devices are customarily used as probes to measure the level of
noble liquids in detectors operated for neutrino studies and dark matter
searches. In this work we describe the use of a high-temperature
superconducting material as an alternative to control the level of a cryogenic
noble liquid. Lab measurements indicate that the superconductor shows a linear
behaviour, a high degree of stability and offers a very accurate determination
of the liquid volume. This device is therefore a competitive instrument and
shows several advantages over conventional level meters.


title:
Emergence of zero-lag synchronization in generic mutually coupled
  chaotic systems

abstract:
  Zero-lag synchronization (ZLS) is achieved in a very restricted mutually
coupled chaotic systems, where the delays of the self-coupling and the mutual
coupling are identical or fulfil some restricted ratios. Using a set of
multiple self-feedbacks we demonstrate both analytically and numerically that
ZLS is achieved for a wide range of mutual delays. It indicates that ZLS can be
achieved without the knowledge of the mutual distance between the communicating
partners and has an important implication in the possible use of ZLS in
communications networks as well as in the understanding of the emergence of
such synchronization in the neuronal activities.


title:
Invariant theory and the W_{1+\infty} algebra with negative integral
  central charge

abstract:
  The vertex algebra W_{1+\infty,c} with central charge c may be defined as a
module over the universal central extension of the Lie algebra of differential
operators on the circle. For an integer n\geq 1, it was conjectured in the
physics literature that W_{1+\infty,-n} should have a minimal strong generating
set consisting of n^2+2n elements. Using a free field realization of
W_{1+\infty,-n} due to Kac-Radul, together with a deformed version of Weyl's
first and second fundamental theorems of invariant theory for the standard
representation of GL_n, we prove this conjecture. A consequence is that the
irreducible, highest-weight representations of W_{1+\infty,-n} are parametrized
by a closed subvariety of C^{n^2+2n}.


title:
Existence and classification of characteristic points at blow-up for a
  semilinear wave equation in one space dimension

abstract:
  We consider the semilinear wave equation with power nonlinearity in one space
dimension. We first show the existence of a blow-up solution with a
characteristic point. Then, we consider an arbitrary blow-up solution $u(x,t)$,
the graph $x\mapsto T(x)$ of its blow-up points and $\SS\subset $ the set of
all characteristic points, and show that the $\SS$ has an empty interior.
Finally, given $x_0\in \SS$, we show that in selfsimilar variables, the
solution decomposes into a decoupled sum of (at least two) solitons with
alternate signs and that $T(x)$ forms a corner of angle $\frac \pi 2$ at $x_0$.


title:
Exploring the dark side of the Universe in a dilatonic brane-world
  scenario

abstract:
  We describe the late-time acceleration of the Universe within the paradigm of
the brane-world scenario. More precisely, we show how a phantom-like behaviour
or a crossing of the cosmological constant line can be achieved safely in a
dilatonic brane-world model with an induced gravity term on the brane. The
brane tension plays the role of dark energy which is coupled to the dilaton
bulk scalar field. The phantom mimicry as well as the crossing of the
cosmological constant line are achieved without invoking any phantom matter
either on the brane or in the bulk.


title:
Plasmon oscillations in ellipsoid nanoparticles: beyond dipole
  approximation

abstract:
  The plasmon oscillations of a metallic triaxial ellipsoid nanoparticle have
been studied within the framework of the quasistatic approximation. A general
method has been proposed for finding the analytical expressions describing the
potential and frequencies of the plasmon oscillations of an arbitrary
multipolarity order. The analytical expressions have been derived for an
electric potential and plasmon oscillation frequencies of the first 24 modes.
Other higher orders plasmon modes are investigated numerically.


title: The nonequilibrium Ehrenfest gas: a chaotic model with flat obstacles?

abstract:
  It is known that the non-equilibrium version of the Lorentz gas (a billiard
with dispersing obstacles, electric field and Gaussian thermostat) is
hyperbolic if the field is small. Differently the hyperbolicity of the
non-equilibrium Ehrenfest gas constitutes an open problem, since its obstacles
are rhombi and the techniques so far developed rely on the dispersing nature of
the obstacles. We have developed analytical and numerical investigations which
support the idea that this model of transport of matter has both chaotic
(positive Lyapunov exponent) and non-chaotic steady states with a quite
peculiar sensitive dependence on the field and on the geometry, not observed
before. The associated transport behaviour is correspondingly highly irregular,
with features whose understanding is of both theoretical and technological
interest.


title:
Transition from Abelian to non-Abelian quantum liquids in the second
  Landau level

abstract:
  The search for non-Abelian quantum Hall states in the second Landau level is
narrowed to the range of filling factors 7/3<\nu_e<8/3. In this range, the
analysis of energy spectra and correlation functions, calculated including
finite width and Landau level mixing, supports the prominent non-Abelian
candidates at \nu_e=5/2 (Moore--Read) and 12/5 (Read--Rezayi). Outside of it,
the four-flux noninteracting composite fermion model is validated. The
borderline \nu_e=7/3 state is adiabatically connected to the Laughlin liquid,
but its short-range correlations and charge excitations are different.


title: Production and evolution path of dileptons at HADES energies

abstract:
  Dilepton production in intermediate energy nucleus-nucleus collisions as well
as in elementary proton-proton reactions is analysed within the UrQMD transport
model. For C+C collisions at 1 AGeV and 2 AGeV the resulting invariant mass
spectra are compared to recent HADES data. We find that the experimental
spectrum for C+C at 2 AGeV is slightly overestimated by the theoretical
calculations in the region around the vector meson peak, but fairly described
in the low mass region, where the data is satisfactorily saturated by the
Dalitz decay of the $\eta$ meson and the $\Delta$ resonance. At 1 AGeV an
underestimation of the experimental data is found, pointing that at lower
energies the low mass region is not fully saturated by standardly parametrized
$\Delta$ Dalitz decays alone. Furthermore, predictions for dilepton spectra for
$pp$ reactions at 1.25 GeV, 2.2 GeV and 3.5 GeV and Ar+KCl reactions at 1.75
AGeV are presented. The study is complemented by a detailed investigation of
the role of absorption of the parent particles on the corresponding dilepton
yields in the regime which has so far been probed by HADES.


title:
Corrections to Hawking-like Radiation for a Friedmann-Robertson-Walker
  Universe

abstract:
  Recently, a Hamilton-Jacobi method beyond semiclassical approximation in
black hole physics was developed by \emph{Banerjee} and
\emph{Majhi}\cite{beyond0}. In this paper, we generalize their analysis of
black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is
shown that all the higher order quantum corrections in the single particle
action are proportional to the usual semiclassical contribution. The
corrections to the Hawking-like temperature and entropy of apparent horizon for
FRW universe are also obtained. In the corrected entropy, the area law involves
logarithmic area correction together with the standard inverse power of area
term.


title:
Invariant classification and the generalised invariant formalism:
  conformally flat pure radiation metrics, with zero cosmological constant

abstract:
  Metrics obtained by integrating within the generalised invariant formalism
are structured around their intrinsic coordinates, and this considerably
simplifies their invariant classification and symmetry analysis. We illustrate
this by presenting a simple and transparent complete invariant classification
of the conformally flat pure radiation metrics (except plane waves) in such
intrinsic coordinates; in particular we confirm that the three apparently
non-redundant functions of one variable are genuinely non-redundant, and easily
identify the subclasses which admit a Killing and/or a homothetic Killing
vector. Most of our results agree with the earlier classification carried out
by Skea in the different Koutras-McIntosh coordinates, which required much more
involved calculations; but there are some subtle differences. Therefore, we
also rework the classification in the Koutras-McIntosh coordinates, and by
paying attention to some of the subtleties involving arbitrary functions, we
are able to obtain complete agreement with the results obtained in intrinsic
coordinates. In particular, we have corrected and completed statements and
results by Edgar and Vickers, and by Skea, about the orders of Cartan
invariants at which particular information becomes available.


title: Non-abelian black holes and black strings in higher dimensions

abstract:
  We review the properties of static, higher dimensional black hole solutions
in theories where non-abelian gauge fields are minimally coupled to gravity. It
is shown that black holes with hyperspherically symmetric horizon topology do
not exist in $d > 4$, but that hyperspherically symmetric black holes can be
constructed numerically in generalized Einstein-Yang-Mills models.
5-dimensional black strings with horizon topology S^2 x S^1 are also discussed.
These are so-called undeformed and deformed non-abelian black strings, which
are translationally invariant and correspond to 4-dimensional non-abelian black
holes trivially extended into one extra dimensions. The fact that black strings
can be deformed, i.e. axially symmetric for constant values of the extra
coordinate is a new feature as compared to black string solutions of Einstein
(-Maxwell) theory. It is argued that these non-abelian black strings are
thermodynamically unstable.


title: Strangeness fluctuations and MEMO production at FAIR

abstract:
  We apply a coupled transport-hydrodynamics model to discuss the production of
multi-strange meta-stable objects in Pb+Pb reactions at the FAIR facility. In
addition to making predictions for yields of these particles we are able to
calculate particle dependent rapidity and momentum distributions. We argue that
the FAIR energy regime is the optimal place to search for multi-strange
baryonic object (due to the high baryon density, favouring a distillation of
strangeness). Additionally, we show results for strangeness and baryon density
fluctuations. Using the UrQMD model we calculate the strangeness seperation in
phase space which might lead to an enhanced production of MEMOs compared to
models that assume global thermalization.


title:
The Search and Study of Low-Mass Scalar Mesons in the Reaction np --> np
  Pi+Pi- at Pn = 5.20 Gev/c^2

abstract:
  Using irradiation of a 1-meter Hydrogen Bubble Chamber (LHE JINR) by a
quasimonochromatic neutron beam with impulse Pn=(5.20 +/- 0.12)GeV/c produced
after acceleration of deuterons in the synchrophasotron (LHE JINR) 2560 events
of reaction np-->npPi+Pi- were selected. After supplementary sorting out the
events where a secondary proton flies forward in the general c.m.s. of reaction
in the effective mass spectrum of Pi+Pi- - combinations, there were nine
peculiarities found out at masses 350, 408, 489, 579, 676, 762, 878, 1036, 1170
MeV/c^2 with experimental widths not more than several tens of MeV/c^2. The
resonance effects grow too much after using an additional criterion - balance
of the sum of the longitudinal impulse of Pi+ and Pi--mesons in the general
c.m.s. of the reaction. Under these conditions the values of a standard
derivation from the background are (5 - 7.5). The direct measurement of the
spin of resonances was carried out. Also other quantum numbers were obtained.
All of these peculiarities have a similar set of quantum numbers
I^G(J^(PC))=0+(0++). This way the sequence of scalar-izoscalar resonances
f0(SIGMA0) with masses in the range of M<M1200 MeV/c^2 are to be seen. There is
no information about these resonances in the literature. The phenomenological
dependence for the resonance mass from its number was found. This dependence
covered not only resonances shown in this paper but also all those which are
present in PDG tables with quantum numbers f0(SIGMA0) - mesons.


title: Brownian motion conditioned to stay in a cone

abstract:
  A result of R. Durrett, D. Iglehart and D. Miller states that Brownian
meander is Brownian motion conditioned to stay positive for a unit of time, in
the sense that it is the weak limit, as $x$ goes to 0, of Brownian motion
started at $x>0$ and conditioned to stay positive for a unit of time. We extend
this limit theorem to the case of multidimensional Brownian motion conditioned
to stay in a smooth convex cone.


title: DG-methods for microlocalization

abstract:
  For a complex manifold $X$ the ring of microdifferential operators $\E_X$
acts on the microlocalization $\mu hom(F,\O_X)$, for $F$ in the derived
category of sheaves on $X$. Kashiwara, Schapira, Ivorra, Waschkies proved, as a
byproduct of their new microlocalization functor for ind-sheaves, $\mu_X$, that
$\mu hom(F,\O_X)$ can in fact be defined as an object of the derived category
of $\E_X$-modules: this follows from the fact that $\mu_X \O_X$ is concentrated
in one degree. In this paper we prove that the tempered microlocalization also
is an object of the derived category of $\E_X$-modules. Since we don't know
whether the tempered version of $\mu_X \O_X$ is concentrated in one degree, we
introduce a method to build suitable resolutions for which the action of $\E_X$
is realized in the category of complexes. We define a version of the de Rham
algebra on the subanalytic site which is quasi-injective and we work in the
category of dg-modules over this de Rham algebra instead of the derived
category of sheaves.


title:
Birkhoff normal form and splitting methods for semi linear Hamiltonian
  PDEs. Part II: Abstract splitting

abstract:
  We consider Hamiltonian PDEs that can be split into a linear unbounded
operator and a regular non linear part. We consider abstract splitting methods
associated with this decomposition where no discretization in space is made. We
prove a normal form result for the corresponding discrete flow under generic
non resonance conditions on the frequencies of the linear operator and on the
step size. This result implies the conservation of the regularity of the
numerical solution associated with the splitting method over arbitrary long
time, provided the initial data is small enough. This result holds for
numerical schemes controlling the round-off error at each step to avoid
possible high frequency energy drift. We apply this results to nonlinear
Schr\"odinger equations as well as the nonlinear wave equation.}


title:
Theory of electric field induced one-magnon resonance in cycloidal spin
  magnets

abstract:
  We propose a new mechanism to induce a novel one-magnon excitation by the
electric component of light in cycloidal spin states, i.e. so called
electromagnon process. We calculated optical spectra in the cycloidal spin
structures as observed in multiferroic perovskite manganites RMnO3 where novel
magnetic excitations induced by oscillating electric fields are observed. When
symmetric spin-dependent electric polarizations are introduced, we have light
absorptions at terahertz frequencies with one- and two-magnon excitations
driven by the electric component of light. Our results show that some parts of
optical spectra observed experimentally at terahertz frequencies are one-magnon
excitation absorptions.


title:
The core helium flash revisited: II. Two and three-dimensional
  hydrodynamic simulations

abstract:
  We study turbulent convection during the core helium flash close to its peak
by comparing the results of two and three-dimensional hydrodynamic simulations.
  We use a multidimensional Eulerian hydrodynamics code based on
state-of-the-art numerical techniques to simulate the evolution of the helium
core of a $1.25 M_{\odot}$ Pop I star.
  Our three-dimensional hydrodynamic simulations of the evolution of a star
during the peak of the core helium flash do not show any explosive behavior.
The convective flow patterns developing in the three-dimensional models are
structurally different from those of the corresponding two-dimensional models,
and the typical convective velocities are smaller than those found in their
two-dimensional counterparts. Three-dimensional models also tend to agree
better with the predictions of mixing length theory. Our hydrodynamic
simulations show the presence of turbulent entrainment that results in a growth
of the convection zone on a dynamic time scale. Contrary to mixing length
theory, the outer part of the convection zone is characterized by a
sub-adiabatic temperature gradient.


title: Counting plane Mumford curves

abstract:
  A $p$-adic version of Gromov-Witten invariants for counting plane curves of
genus $g$ and degree $d$ through a given number of points is discussed. The
multiloop version of $p$-adic string theory considered by Chekhov and others
motivates us to ask how many of these curves are Mumford curves, i.e.\
uniformisable by a domain at the boundary of the Bruhat-Tits tree for
$\PGL_2(\mathbb{Q}_p)$. Generally, the number of Mumford curves depends on the
position of the given points in $\mathbb{P}^2$. With the help of tropical
geometry we find configurations of points through which all curves of given
degree and genus are Mumford curves. The article is preceded by an introduction
to some concepts of $p$-adic geometry and their relation to string theory.


title:
Unveiling the nature of INTEGRAL objects through optical spectroscopy.
  VII. Identification of 20 Galactic and extragalactic hard X-ray sources

abstract:
  Within the framework of our program of assessment of the nature of
unidentified or poorly known INTEGRAL sources, we present here spectroscopy of
optical objects, selected through positional cross-correlation with soft X-ray
detections (afforded with satellites such as Swift, ROSAT, Chandra and/or
XMM-Newton) as putative counterparts of hard X-ray sources detected with the
IBIS instrument onboard INTEGRAL. Using 6 telescopes of various sizes and
archival data from two on-line spectroscopic surveys we are able to identify,
either for the first time or independent of other groups, the nature of 20
INTEGRAL hard X-ray sources. Our results indicate that: 11 of these objects are
active galactic nuclei (AGNs) at redshifts between 0.014 and 0.978, 7 of which
display broad emission lines, 2 show narrow emission lines only, and 2 have
unremarkable or no emission lines (thus are likely Compton thick AGNs); 5 are
cataclysmic variables (CVs), 4 of which are (possibly magnetic) dwarf novae and
one is a symbiotic star; and 4 are Galactic X-ray binaries (3 with high-mass
companions and one with a low-mass secondary). It is thus again found that the
majority of these sources are AGNs or magnetic CVs, confirming our previous
findings. When possible, the main physical parameters for these hard X-ray
sources are also computed using the multiwavelength information available in
the literature. These identifications support the importance of INTEGRAL in the
study of the hard X-ray spectrum of all classes of X-ray emitting objects, and
the effectiveness of a strategy of multi-catalogue cross-correlation plus
optical spectroscopy to securely pinpoint the actual nature of unidentified
hard X-ray sources.


title: A possible Efimov trimer state in a 3-component lithium-6 mixture

abstract:
  We consider the Efimov trimer theory as a possible framework to explain
recently observed losses by inelastic three-body collisions in a
three-hyperfine-component ultracold mixture of lithium 6. Within this
framework, these losses would arise chiefly from the existence of an Efimov
trimer bound state below the continuum of free triplets of atoms, and the loss
maxima (at certain values of an applied magnetic field) would correspond to
zero-energy resonances where the trimer dissociates into three free atoms. Our
results show that such a trimer state is indeed possible given the two-body
scattering lengths in the three-component lithium mixture, and gives rise to
two zero-energy resonances. The locations of these resonances appear to be
consistent with observed losses.


title: Dynkin operators and renormalization group actions in pQFT

abstract:
  Renormalization techniques in perturbative quantum field theory were known,
from their inception, to have a strong combinatorial content emphasized, among
others, by Zimmermann's celebrated forest formula. The present article reports
on recent advances on the subject, featuring the role played by the Dynkin
operators (actually their extension to the Hopf algebraic setting) at two
crucial levels of renormalization, namely the Bogolioubov recursion and the
renormalization group (RG) equations. For that purpose, an iterated integrals
toy model is introduced to emphasize how the operators appear naturally in the
setting of renormalization group analysis. The toy model, in spite of its
simplicity, captures many key features of recent approaches to RG equations in
pQFT, including the construction of a universal Galois group for quantum field
theories.


title:
Modifications of single-particle properties in nuclear matter induced by
  three-body forces

abstract:
  Within the self-consistent Green's functions formalism, we study the effects
of three-body forces on the in-medium spectral function, self-energy and
effective mass of the nuclear matter constituents, analyzing the density and
momentum dependence.


title: Interval greedoids and families of local maximum stable sets of graphs

abstract:
  A maximum stable set in a graph G is a stable set of maximum cardinality. S
is a local maximum stable set of G, if S is a maximum stable set of the
subgraph induced by its closed neighborhood.
  Nemhauser and Trotter Jr. proved in 1975 that any local maximum stable set is
a subset of a maximum stable set of G. In 2002 we showed that the family of all
local maximum stable sets of a forest forms a greedoid on its vertex set. The
cases where G is bipartite, triangle-free, well-covered, while the family of
all local maximum stable sets is a greedoid, were analyzed in 2004, 2007, and
2008, respectively.
  In this paper we demonstrate that if the family of all local maximum stable
sets of the graph satisfies the accessibility property, then it is an interval
greedoid. We also characterize those graphs whose families of local maximum
stable sets are either antimatroids or matroids.


title: Module categories over pointed Hopf algebras

abstract:
  We develop some techniques to the study of exact module categories over some
families of pointed finite-dimensional Hopf algebras. As an application we
classify exact module categories over the tensor category of representations of
the small quantum groups $u_q(\mathfrak{sl}_2)$.


title:
Microscopic linear response calculations based on the Skyrme functional
  plus the pairing contribution

abstract:
  A self-consistent Quasiparticle-Random-Phase-Approximation (QRPA) model which
employs the canonical Hartree-Fock-Bogoliubov (HFB) basis and an energy-density
functional with a Skyrme mean field part and a density-dependent pairing, is
used to study the monopole collective excitations of spherical even-even
nuclei. The influence of the spurious state on the strength function of the
isoscalar monopole excitations is clearly assessed. We compare the effect of
different kinds of pairing forces (volume pairing, surface pairing and mixed
pairing) on the monopole excitation strength function. The energy of the
Isoscalar Giant Monopole Resonance (ISGMR), which is related to the nuclear
incompressibility $K_{\infty}$, is calculated for tin isotopes and the results
are discussed.


title:
On the Issue of the \zeta Series Convergence and Loop Corrections in the
  Generation of Observable Primordial Non-Gaussianity in Slow-Roll Inflation.
  Part II: the Trispectrum

abstract:
  We calculate the trispectrum T_\zeta of the primordial curvature perturbation
\zeta, generated during a {\it slow-roll} inflationary epoch by considering a
two-field quadratic model of inflation with {\it canonical} kinetic terms. We
consider loop contributions as well as tree level terms, and show that it is
possible to attain very high, {\it including observable}, values for the level
of non-gaussianity \tau_{NL} if T_\zeta is dominated by the one-loop
contribution. Special attention is paid to the claim in JCAP {\bf 0902}, 017
(2009) [arXiv:0812.0807 [astro-ph]] that, in the model studied in this paper
and for the specific inflationary trajectory we choose, the quantum
fluctuations of the fields overwhelm the classical evolution. We argue that
such a claim actually does not apply to our model, although more research is
needed in order to understand the role of quantum diffusion. We also consider
the probability that an observer in an ensemble of realizations of the density
field sees a non-gaussian distribution. In that respect, we show that the
probability associated to the chosen inflationary trajectory is non-negligible.
Finally, the levels of non-gaussianity f_{NL} and \tau_{NL} in the bispectrum
B_\zeta and trispectrum T_\zeta of \zeta, respectively, are also studied for
the case in which \zeta is not generated during inflation.


title: Shell gaps and pn pairing interaction in N = Z nuclei

abstract:
  We analyze the observed shell gaps in N=Z nuclei determined from the binding
energy differences. It is found that the shell gaps can be described by the
combined contributions from the single-particle level spacing, the like-nucleon
pairing, and the proton-neutron pairing interaction. This conclusion is
consistent with that of Chasman in Phys. Rev. Lett. 99 (2007) 082501. For the
double-closed shell N=Z nuclei, the single-particle level spacings calculated
with Woods-Saxon potential are very close to those obtained by subtracting the
nn pairing interaction from the observed shell gap. For the sub-closed or
non-closed shell N=Z nuclei, the pn pairing interaction is shown to be
important for the observed shell gaps.