title:
Inverse approach to Einstein's equations for fluids with vanishing
  anisotropic stress tensor

abstract:
  We expand previous work on an inverse approach to Einstein Field Equations
where we include fluids with energy flux and consider the vanishing of the
anisotropic stress tensor. We consider the approach using warped product
spacetimes of class $B_1$. Although restricted, these spacetimes include many
exact solutions of interest to compact object studies and to cosmological
models studies. The question explored here is as follows: given a spacetime
metric, what fluid flow (timelike congruence), if any, could generate the
spacetime via Einstein's equations. We calculate the flow from the condition of
a vanishing anisotropic stress tensor and give results in terms of the metric
functions in the three canonical types of coordinates. A condition for perfect
fluid sources is also provided. The framework developed is algorithmic and
suited for the study and validation of exact solutions using computer algebra
systems. The framework can be applied to solutions in comoving and non-comoving
frames of reference, and examples in different types of coordinates are worked
out.


title: Mixed Lefschetz Theorems and Hodge-Riemann Bilinear Relations

abstract:
  Statements analogous to the Hard Lefschetz Theorem (HLT) and the
Hodge-Riemann bilinear relations (HRR) hold in a variety of contexts: they
impose restrictions on the cohomology algebra of a smooth compact K\"ahler
manifold or on the intersection cohomology of a projective toric variety; they
restrict the local monodromy of a polarized variation of Hodge structure; they
impose conditions on the possible $f$-vectors of convex polytopes. While the
statements of these theorems depend on the choice of a K\"ahler class, or its
analog, there is usually a cone of possible K\"ahler classes. It is then
natural to ask whether the HLT and HRR remain true in a mixed context. In this
note we present a unified approach to proving the mixed HLT and HRR,
generalizing the previously known results, and proving it in new cases such as
the intersection cohomology of non-rational polytopes.


title: Poincare duality and Periodicity

abstract:
  We construct periodic families of Poincare complexes, partially solving a
question of Hodgson that was posed in the proceedings of the 1982 Northwestern
homotopy theory conference. We also construct infinite families of Poincare
complexes whose top cell falls off after one suspension but which fail to embed
in a sphere of codimension one. We give a homotopy theoretic description of the
four-fold periodicity in knot cobordism.


title:
Microscopic surface structure of C/SiC composite mirrors for space
  cryogenic telescopes

abstract:
  We report on the microscopic surface structure of carbon-fiber-reinforced
silicon carbide (C/SiC) composite mirrors that have been improved for the Space
Infrared Telescope for Cosmology and Astrophysics (SPICA) and other cooled
telescopes. The C/SiC composite consists of carbon fiber, silicon carbide, and
residual silicon. Specific microscopic structures are found on the surface of
the bare C/SiC mirrors after polishing. These structures are considered to be
caused by the different hardness of those materials. The roughness obtained for
the bare mirrors is 20 nm rms for flat surfaces and 100 nm rms for curved
surfaces. It was confirmed that a SiSiC slurry coating is effective in reducing
the roughness to 2 nm rms. The scattering properties of the mirrors were
measured at room temperature and also at 95 K. No significant change was found
in the scattering properties through cooling, which suggests that the
microscopic surface structure is stable with changes in temperature down to
cryogenic values. The C/SiC mirror with the SiSiC slurry coating is a promising
candidate for the SPICA telescope.


title: Graphs of functions and vanishing free entropy

abstract:
  Suppose X is an n-tuple of selfadjoint elements in a tracial von Neumann
algebra M. If z is a selfadjoint element in M and for some selfadjoint element
y in the von Neumann algebra generated by X $\delta_0(y, z) < \delta_0(y) +
\delta_0(z)$, then $\chi(X \cup \{z\}) = -\infty$ (here $\chi$ and $\delta_0$
denote the microstates free entropy and free entropy dimension, respectively).
In particular, if z lies in the von Neumann algebra generated by X, then
$\chi(X \cup \{z\}) = -\infty$. The statement and its proof are motivated by
geometric-measure-theoretic results on graphs of functions. A similar statement
for the nonmicrostates free entropy is obtained under the much stronger
hypothesis that z lies in the algebra generated by X.


title: Mirror symmetry aspects for compact G_2 manifolds

abstract:
  The present paper deals with mirror symmetry aspects of compact ``barely''
$G_2$ manifolds, that is, $G_2$ manifolds of the form (CY$\times
S^1)/\mathbb{Z}_2$. We propose that the mirror of any barely $G_2$ manifold is
another barely one and which is constructed as a fibration of the \emph{mirror}
of the CY base. Also, we describe the Joyce manifolds of the first kind as
``barely'' and we show that the underlying CY of all the family is self-mirror
with $h^{1,1}=h^{2,1}=19$. We thus propose that the mirror of a Joyce space of
the first kind will be another Joyce space of the first kind.We also suggest
that this self-mirror CY family is dual to K3$\times S^1$ in the
heterotic/M-theory sense, and that arise as a particular case of the
Borcea-Voisin construction. As a spin-off we conclude from this analysis that
no 5-brane instantons are present in compactifications of eleven dimensional
supergravity over Joyce manifolds of the first kind.


title: Calculations of canonical averages from the grand canonical ensemble

abstract:
  Grand canonical and canonical ensembles become equivalent in the
thermodynamic limit, but when the system size is finite the results obtained in
the two ensembles deviate from each other. In many important cases, the
canonical ensemble provides an appropriate physical description but it is often
much easier to perform the calculations in the corresponding grand canonical
ensemble. We present a method to compute averages in canonical ensemble based
on calculations of the expectation values in grand canonical ensemble. The
number of particles, which is fixed in the canonical ensemble, is not
necessarily the same as the average number of particles in the grand canonical
ensemble.


title:
Self-dual Vortices in the Abelian Chern-Simons Model with Two Complex
  Scalar Fields

abstract:
  Making use of $\phi$-mapping topological current method, we discuss the
self-dual vortices in the Abelian Chern-Simons model with two complex scalar
fields. For each scalar field, an exact nontrivial equation with a topological
term which is missing in many references is derived analytically. The general
angular momentum is obtained. The magnetic flux which relates the two scalar
fields is calculated. Furthermore, we investigate the vortex evolution
processes, and find that because of the present of the vortex molecule, these
evolution processes is more complicated than the vortex evolution processes in
the corresponding single scalar field model.


title: NMR Evidence for Spin Canting in a Bilayer nu = 2 Quantum Hall System

abstract:
  We investigate the electron spin states in the bilayer quantum Hall system at
total Landau level filling factor nu =2 exploiting current-pumped and
resistively detected NMR. The measured Knight shift, KS, of 75As nuclei reveals
continuous variation of the out-of-plane electronic spin polarization between
nearly full and zero as a function of density imbalance. Nuclear spin
relaxation measurements indicate a concurrent development of an in-plane spin
component. These results provide direct information on the spin configuration
in this system and comprise strong evidence for the spin canting suggested by
previous experiments.


title:
On the Distance and Molecular Environment of Westerlund 2 and HESS
  J1023-575

abstract:
  The extended TeV gamma-ray source HESS J1023-575 is coincident with the
massive, young stellar cluster Westerlund 2 (Wd2) and its surrounding HII
region RCW 49. On the basis of an analysis of the CO emission and 21 cm
absorption along the line of sight to Wd2, it is argued that this cluster, and
by assumption the TeV source as well, must be associated with a giant molecular
cloud in the far side of the Carina arm with a mass of 7.5 x 10^5 Mo. Analysis
of the spatial and velocity structure of the cloud reveals clear evidence of
interaction with Wd2. The cloud's kinematic distance of 6.0 +/- 1.0 kpc is
shown to be consistent with distances inferred both from the radius-linewidth
relation of molecular clouds and from the foreground gas column derived from
230 X-ray sources in Wd2.


title: A generalization of the Shestakov-Umirbaev inequality

abstract:
  We give a generalization of the Shestakov-Umirbaev inequality which plays an
important role in their solution of the tame generators conjecture.


title: Pareto Optima of Multicriteria Integer Linear Programs

abstract:
  We settle the computational complexity of fundamental questions related to
multicriteria integer linear programs, when the dimensions of the strategy
space and of the outcome space are considered fixed constants. In particular we
construct:
  1. polynomial-time algorithms to exactly determine the number of Pareto
optima and Pareto strategies;
  2. a polynomial-space polynomial-delay prescribed-order enumeration algorithm
for arbitrary projections of the Pareto set;
  3. an algorithm to minimize the distance of a Pareto optimum from a
prescribed comparison point with respect to arbitrary polyhedral norms;
  4. a fully polynomial-time approximation scheme for the problem of minimizing
the distance of a Pareto optimum from a prescribed comparison point with
respect to the Euclidean norm.


title: A Compact Approximate Solution to the Kondo Problem

abstract:
  A compact approximate groundstate of the Kondo problem is introduced. It
consists of four Slater states. The spin up and down states of the localized
d-impurity are paired with two localized s-electron states of opposite spin.
All the remaining s-electron states are rearranged forming two new optimal
orthonormal bases. Through a rotation in Hilbert space the two localized states
(and the rest of the bases) are optimized by minimizing the energy expectation
value. The ground-state energy E and the singlet-triplet excitation energy dE
are calculated numerically. Although the two energies can differ by a factor of
1000, they are obtained simultaneously. The singlet-triplet excitation energy
dE is proportional to exp[-1/2Jg] and quite close to the Kondo temperature
k_BT_K. The cases for anti-ferromagnetic (J>0) and ferromagnetic (J<0) coupling
are investigated.


title: Report on Generic Case Complexity

abstract:
  This article is a short introduction to generic case complexity, which is a
recently developed way of measuring the difficulty of a computational problem
while ignoring atypical behavior on a small set of inputs. Generic case
complexity applies to both recursively solvable and recursively unsolvable
problems.


title: Conditions for Generic Initial Ideals to be Almost Reverse Lexicographic

abstract:
  Let $I$ be a homogeneous Artinian ideal in a polynomial ring
$R=k[x_1,...,x_n]$ over a field $k$ of characteristic 0. We study an equivalent
condition for the generic initial ideal $\gin(I)$ with respect to reverse
lexicographic order to be almost reverse lexicographic. As a result, we show
that Moreno-Socias conjecture implies Fr\"{o}berg conjecture. And for the case
$\Codim I \le 3$, we show that $R/I$ has the strong Lefschetz property if and
only if $\gin(I)$ is almost reverse lexicographic. Finally for a monomial
complete intersection Artinian ideal $I=(x_1^{d_1},...,x_n^{d_n})$, we prove
that $\gin(I)$ is almost reverse lexicographic if $d_i > \sum_{j=1}^{i-1} d_j -
i + 1$ for each $i \ge 4$. Using this, we give a positive partial answer to
Moreno-Socias conjecture, and to Fr\"{o}berg conjecture.


title:
Neutron Scattering Study of the Localized Mode in the beta-Pyrochlore
  Superconductors AOs2O6

abstract:
  Inelastic neutron scattering and neutron powder diffraction experiments were
carried out to investigate a localized mode, proposed from various bulk
measurements, in the beta-pyrochlore AOs2O6 (A=K, Rb, Cs). The localized mode
was identified in all the three compounds as well as another beta-pyrochlore
CsW2O6. The anharmonicity of the mode is weak in RbOs2O6 and CsOs2O6 but
substantial in KOs2O6.


title:
Generation and Measurement of Non Equilibrium Spin Currents in Two
  Terminal Systems

abstract:
  Generation and measurement of non-equilibrium spin current in two probe
configuration is discussed. It is argued and shown that spin current can be
generated in two terminal non-magnetic system. Further it is shown that these
spin currents can be measured via conductance in two probe configuration when
the detector probe is ferromagnetic.


title: Generalized Bounded Variation and Inserting point masses

abstract:
  Let $d\mu$ be a probability measure on the unit circle and $d\nu$ be the
measure formed by adding a pure point to $d\mu$. We give a simple formula for
the Verblunsky coefficients of $d\nu$ based on a result of Simon.
  Then we consider $d\mu_0$, a probability measure on the unit circle with
$\ell^2$ Verblunsky coefficients $(\alpha_n (d\mu_0))_{n=0}^{\infty}$ of
bounded variation. We insert $m$ pure points to $d\mu$, rescale, and form the
probability measure $d\mu_m$. We use the formula above to prove that the
Verblunsky coefficients of $d\mu_m$ are in the form $\alpha_n(d\mu_0) +
\sum_{j=1}^m \frac{\ol{z_j}^{n} c_j}{n} + E_n$, where the $c_j$'s are constants
of norm 1 independent of the weights of the pure points and independent of $n$;
the error term $E_n$ is in the order of $o(1/n)$. Furthermore, we prove that
$d\mu_m$ is of $(m+1)$-generalized bounded variation - a notion that we shall
introduce in the paper. Then we use this fact to prove that $\lim_{n \to
\infty} \vp_n^*(z, d\mu_m)$ is continuous and is equal to $D(z, d\mu_m)^{-1}$
away from the pure points.


title: Impact of Locally Suppressed Wave sources on helioseismic travel times

abstract:
  Wave travel-time shifts in the vicinity of sunspots are typically interpreted
as arising predominantly from magnetic fields, flows, and local changes in
sound speed. We show here that the suppression of granulation related wave
sources in a sunspot can also contribute significantly to these travel-time
shifts, and in some cases, an asymmetry between in and outgoing wave travel
times. The tight connection between the physical interpretation of travel times
and source-distribution homogeneity is confirmed. Statistically significant
travel-time shifts are recovered upon numerically simulating wave propagation
in the presence of a localized decrease in source strength. We also demonstrate
that these time shifts are relatively sensitive to the modal damping rates;
thus we are only able to place bounds on the magnitude of this effect. We see a
systematic reduction of 10-15 seconds in $p$-mode mean travel times at short
distances ($\sim 6.2$ Mm) that could be misinterpreted as arising from a
shallow (thickness of 1.5 Mm) increase ($\sim$ 4%) in the sound speed. At
larger travel distances ($\sim 24$ Mm) a 6-13 s difference between the ingoing
and outgoing wave travel times is observed; this could mistakenly be
interpreted as being caused by flows.


title: Neutral-current Neutrino-nucleus Scattering in Quasielastic Region

abstract:
  The neutral-current neutrino-nucleus scattering is calculated through the
neutrino-induced knocked-out nucleon process in the quasielastic region by
using a relativistic single particle model for the bound and continuum states.
The incident energy range between 500 MeV and 1.0 GeV is used for the neutrino
(antineutrino) scattering on ^{12}C target nucleus. The effects of the final
state interaction of the knocked-out nucleon are studied not only on the cross
section but also on the asymmetry due to the difference between neutrinos and
antineutrinos, within a relativistic optical potential. We also investigate the
sensitivity of the strange quark contents in the nucleon on the asymmetry.


title:
Accesing the Gluon Polarization through the Double Longitudinal Spin
  Asymmetrie in Charged Pion Production at PHENIX

abstract:
  With proton-proton collisions at PHENIX a variety of direct channels are used
to probe the proton substructure. Of the many channels available at PHENIX,
charged pion measurements are expected to have sensitivity of Delta g and thus
help in the global analysis that will constrain it. We present a measurement of
mid-rapidity charged pion production double longitudinal spin asymmetries (ALL)
at the pT range of 5-10 GeV/c at collision energies of sqrt(s) = 200 GeV.


title: Computability Closure: Ten Years Later

abstract:
  The notion of computability closure has been introduced for proving the
termination of higher-order rewriting with first-order matching by Jean-Pierre
Jouannaud and Mitsuhiro Okada in a 1997 draft which later served as a basis for
the author's PhD. In this paper, we show how this notion can also be used for
dealing with beta-normalized rewriting with matching modulo beta-eta (on
patterns \`a la Miller), rewriting with matching modulo some equational theory,
and higher-order data types (types with constructors having functional
recursive arguments). Finally, we show how the computability closure can easily
be turned into a reduction ordering which, in the higher-order case, contains
Jean-Pierre Jouannaud and Albert Rubio's higher-order recursive path ordering
and, in the first-order case, is equal to the usual first-order recursive path
ordering.


title:
Polarized Parton Densities and Higher Twist in the Light of the Recent
  CLAS and COMPASS data

abstract:
  The impact of the recent very precise CLAS and COMPASS g_1/F_1 data on
polarized parton densities and higher twist effects is discussed. We
demonstrate that the low Q^2 CLAS data improve essentially our knowledge of
higher twist corrections to the spin structure function g1, while the large Q^2
COMPASS data influence mainly the strange quark and gluon polarizations which
slightly decrease. We find also that the present inclusive DIS data cannot rule
out a negative polarized and changing in sign gluon densities.


title: The quantummechanical wave equations from a relativistic viewpoint

abstract:
  A derivation is presented of the quantummechanical wave equations based upon
the Equity Principle of Einstein's General Relativity Theory. This is believed
to be more generic than the common derivations based upon Einstein's energy
relationship for moving particles. It is shown that Schrodinger's Equation, if
properly formulated, is relativisticly covariant. This makes the critisized
Klein-Gordon Equation for spinless massparticles obsolete. Therefore Dirac's
Equation is presented from a different viewpoint and it is shown that the
relativistic covariance of Schrodinger's Equation gives a natural explanation
for the dual energy outcome of Dirac's derivation and for the nature of
antiparticles. The propagation of wave functions in an energy field is studied
in terms of propagation along geodesic lines in curved space-time, resulting in
an equivalent formulation as with Feynman's path integral. It is shown that
Maxwell's wave equation fits in the developed framework as the massless limit
of moving particles. Finally the physical appearance of electrons is discussed
including a quantitative calculation of the jitter phenomenon of a free moving
electron.


title: Szego kernels, Toeplitz operators, and equivariant fixed point formulae

abstract:
  Let $\gamma$ be an automorphism of a polarized complex projective manifold
$(M,L)$. Then $\gamma$ induces an automorphism $\gamma_k$ of the space of
global holomorphic sections of the $k$-th tensor power of $L$, for every
$k=1,2,...$; for $k\gg 0$, the Lefschetz fixed point formula expresses the
trace of $\gamma_k$ in terms of fixed point data. More generally, one may
consider the composition of $\gamma_k$ with the Toeplitz operator associated to
some smooth function on $M$. Still more generally, in the presence of the
compatible action of a compact and connected Lie group preserving
$(M,L,\gamma)$, one may consider induced linear maps on the equivariant
summands associated to the irreducible representations of $G$. In this paper,
under familiar assumptions in the theory of symplectic reductions, we show that
the traces of these maps admit an asymptotic expansion as $k\to +\infty$, and
compute its leading term.


title: Can Phantom-Dominated Universe Decelerate Also in Future ?

abstract:
  Here Randall-Sundrum brane-gravity models of the homogeneous and flat
universe, dominated by phantom fluid, is considered. It is noted that
brane-gravity corrections effect the behaviour of phantom fluid in RS-II model
(where brane-tension $\lambda$ is negative) drastically. It is interesting to
see that, phantom fluid violates the weak energy condition (WEC) till energy
density $\rho < \lambda$, but when phantom energy density $\rho$ grows more,
the effective equation of state does not violate WEC. Moreover, with increasing
phantom energy density, a stage comes when even strong energy condition is not
violated due to effect of these corrections. Also expansion stops, when $\rho =
2 \lambda$. As a consequence, RS-II phantom universe accelerates upto a finite
time explaining the present cosmic acceleration, but it decelerates later.Thus,
RS-II phantom universe is singularity-free. In the case of RS-I model, where
$\lambda$ is positive, characteristics of phantom fluid is not suppressed by
brane-corrections and phantom universe accelerates ending up in big-rip
singularity in finite future time.


title: On the Potential of Large Ring Lasers

abstract:
  We describe a new ring laser with area A = 833 m^2 and update performance
statistics for several such machines. Anandan & Chaio 1982 judged ring lasers
inferior to matter interferometers as possible detectors of gravitational
waves. However, we note that geophysically interesting results have been
obtained from large ring lasers and that there is still a lot of room for
improvements.


title: Pileup subtraction using jet areas

abstract:
  One of the major challenges for the LHC will be to extract precise
information from hadronic final states in the presence of the large number of
additional soft pp collisions, pileup, that occur simultaneously with any hard
interaction in high luminosity runs. We propose a novel technique, based on jet
areas, that provides jet-by-jet corrections for pileup and underlying-event
effects. It is data driven, does not depend on Monte Carlo modelling and can be
used with any jet algorithm for which a jet area can be sensibly defined. We
illustrate its effectiveness for some key processes and find that it can be
applied also in the context of the Tevatron, low-luminosity LHC and LHC
heavy-ion collisions.


title:
Streamwise evolution of the entrainment in a steady two-dimensional
  bluff-body wake

abstract:
  This paper has been withdrawn by the authors, as it has been rejected in
October 2007.


title:
Low-mass lithium-rich AGB stars in the Galactic bulge: evidence for Cool
  Bottom Processing?

abstract:
  Context: The stellar production of the light element lithium is still a
matter of debate.
  Aims: We report the detection of low-mass, Li-rich Asymptotic Giant Branch
(AGB) stars located in the Galactic bulge.
  Methods: A homogeneous and well-selected sample of low mass, oxygen-rich AGB
stars in the Galactic bulge has been searched for the absorption lines of Li.
Using spectral synthesis techniques, we determine from high resolution UVES/VLT
spectra the Li abundance in four out of 27 sample stars, and an upper limit for
the remaining stars.
  Results: Two stars in our sample have a solar Li abundance or above; these
stars seem to be a novelty, since they do not show any s-element enhancement.
Two more stars have a Li abundance slightly below solar; these stars do show
s-element enhancement in their spectra. Different scenarios which lead to an
increased Li surface abundance in AGB stars are discussed.
  Conclusions: Of the different enrichment scenarios presented, Cool Bottom
Processing (CBP) is the most likely one for the Li-rich objects identified
here. Self-enrichment by Hot Bottom Burning (HBB) seems very unlikely as all
Li-rich stars are below the HBB mass limit. Also, the ingestion of a low mass
companion into the stars' envelope is unlikely because the associated
additional effects are lacking. Mass transfer from a former massive binary
companion is a possible scenario, if the companion produced little s-process
elements. A simple theoretical estimation for the Li abundance due to CBP is
presented and compared to the observed values.


title:
The characteristic quasi-polynomials of the arrangements of root systems
  and mid-hyperplane arrangements

abstract:
  Let $q$ be a positive integer. In our recent paper, we proved that the
cardinality of the complement of an integral arrangement, after the modulo $q$
reduction, is a quasi-polynomial of $q$, which we call the characteristic
quasi-polynomial. In this paper, we study general properties of the
characteristic quasi-polynomial as well as discuss two important examples: the
arrangements of reflecting hyperplanes arising from irreducible root systems
and the mid-hyperplane arrangements. In the root system case, we present a
beautiful formula for the generating function of the characteristic
quasi-polynomial which has been essentially obtained by Ch. Athanasiadis and by
A. Blass and B. Sagan. On the other hand, it is hard to find the generating
function of the characteristic quasi-polynomial in the mid-hyperplane
arrangement case. We determine them when the dimension is less than six.


title: Thermal Phase in Bubbling Geometries

abstract:
  This paper has been withdrawn by the author due to a crucial sign error in
equation 1.


title: Vortex rings in ferromagnets

abstract:
  Vortex ring solutions are presented for the Landau-Lifshitz equation, which
models the dynamics of a three-dimensional ferromagnet. The vortex rings
propagate at constant speed along their symmetry axis and are characterized by
the integer-valued Hopf charge. They are stable to axial perturbations, but it
is demonstrated that an easy axis anisotropy results in an instability to
perturbations which break the axial symmetry. The unstable mode corresponds to
a migration of spin flips around the vortex ring that leads to a pinching
instability and ultimately the collapse of the vortex ring. It is found that
this instability does not exist for an isotropic ferromagnet. Similarities
between vortex rings in ferromagnets and vortons in cosmology are noted.


title:
Asymptotically Optimal Estimator of the Parameter of Semi-Linear
  Autoregression

abstract:
  The difference equations $\xi_{k}=af(\xi_{k-1})+\epsilon_{k}$, where
$(\epsilon_k)$ is a square integrable difference martingale, and the
differential equation ${\rm d}\xi=-af(\xi){\rm d}t+{\rm d}\eta$, where $\eta$
is a square integrable martingale, are considered. A family of estimators
depending, besides the sample size $n$ (or the observation period, if time is
continuous) on some random Lipschitz functions is constructed. Asymptotic
optimality of this estimators is investigated.


title:
Measurement of eta photoproduction on the proton from threshold to 1500
  MeV

abstract:
  Beam asymmetry and differential cross section for the reaction gamma+p->eta+p
were measured from production threshold to 1500 MeV photon laboratory energy.
The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0,
were analyzed. The full set of measurements is in good agreement with
previously published results. Our data were compared with three models. They
all fit satisfactorily the results but their respective resonance contributions
are quite different. The possible photoexcitation of a narrow state N(1670) was
investigated and no evidence was found.


title: Optical far-infrared properties of graphene monolayer and multilayers

abstract:
  We analyze the features of the graphene mono- and multilayer reflectance in
the far-infrared region as a function of frequency, temperature, and carrier
density taking the intraband conductance and the interband electron absorbtion
into account. The dispersion of plasmon mode of the multilayers is calculated
using Maxwell's equations with the influence of retardation included. At low
temperatures and high electron densities, the reflectance of multilayers as a
function of frequency has the sharp downfall and the subsequent deep well due
to the threshold of electron interband absorbtion.


title:
Equisingularity classes of birational projections of normal
  singularities to a plane

abstract:
  Given a birational normal extension S of a two-dimensional local regular ring
R, we describe all the equisingularity types of the complete ideals J in R
whose blowing-up has some point at which the local ring is analytically
isomorphic to S.
  The problem of classifying the germs of such normal surface singularities was
already posed by Spivakovsky (Ann. of Math. 1990). This problem has two parts:
discrete and continous. The continous part is to some extent equivalent to the
problem of the moduli of plane curve singularities, while the main result of
this paper solves completely the discrete part.


title: Three-Loop Chromomagnetic Interaction in HQET

abstract:
  We compute the three-loop QCD corrections to the quark chromomagnetic moment
and thus obtain the matching coefficient and the anomalous dimension of the
chromomagnetic interaction in HQET. As a byproduct we obtain the three-loop
corrections to the quark anomalous magnetic moment.


title:
The AS-Cohen-Macaulay property for quantum flag manifolds of minuscule
  weight

abstract:
  It is shown that quantum homogeneous coordinate rings of generalised flag
manifolds corresponding to minuscule weights, their Schubert varieties, big
cells, and determinantal varieties are AS-Cohen-Macaulay. The main ingredient
in the proof is the notion of a quantum graded algebra with a straightening
law, introduced by T.H. Lenagan and L. Rigal [J. Algebra 301 (2006), 670-702].
Using Stanley's Theorem it is moreover shown that quantum generalised flag
manifolds of minuscule weight and their big cells are AS-Gorenstein.


title: Probability Measures and Effective Randomness

abstract:
  We study the question, ``For which reals $x$ does there exist a measure $\mu$
such that $x$ is random relative to $\mu$?'' We show that for every
nonrecursive $x$, there is a measure which makes $x$ random without
concentrating on $x$. We give several conditions on $x$ equivalent to there
being continuous measure which makes $x$ random. We show that for all but
countably many reals $x$ these conditions apply, so there is a continuous
measure which makes $x$ random. There is a meta-mathematical aspect of this
investigation. As one requires higher arithmetic levels in the degree of
randomness, one must make use of more iterates of the power set of the
continuum to show that for all but countably many $x$'s there is a continuous
$\mu$ which makes $x$ random to that degree.


title: Tc oscillations in multilayered cuprates superconductors

abstract:
  When combining the BCS expression of Tc with a shear modulus constant model,
we can demonstrate that Tc oscillates depending on the number of the cuprate
planes and that it reaches its first maximum for three planes. This is in good
agreement with experimental data and suggests that the electron- phonon
coupling is essential to the superconductivity of the cuprates.


title:
Doped Valence Bond Solid and Superconductivity on the Shastry-Sutherland
  Lattice

abstract:
  Motivated by recent experiments on SrCu$_2$(BO$_3$)$_2$, we investigate the
ground states of the doped Mott insulator on the Shastry-Sutherland lattice. To
provide a unified theoretical framework for both the valence-bond solid state
found in undoped SrCu$_2$(BO$_3$)$_2$ and the doped counterpart being pursued
in on-going experiments, we analyze the t-J-$V$ model via the bond operator
formulation. It is found that novel superconducting states emerge upon doping
with their properties crucially depending on the underlying valence bond order.
Implications to future experiments are discussed.


title:
Hidden nonlinear su(2|2) superunitary symmetry of N=2 superextended 1D
  Dirac delta potential problem

abstract:
  We show that the N=2 superextended 1D quantum Dirac delta potential problem
is characterized by the hidden nonlinear $su(2|2)$ superunitary symmetry. The
unexpected feature of this simple supersymmetric system is that it admits three
different $\mathbb Z_2$-gradings, which produce a separation of 16 integrals of
motion into three different sets of 8 bosonic and 8 fermionic operators. These
three different graded sets of integrals generate two different nonlinear,
deformed forms of $su(2|2)$, in which the Hamiltonian plays a role of a
multiplicative central charge. On the ground state, the nonlinear superalgebra
is reduced to the two distinct 2D Euclidean analogs of a superextended
Poincar\'e algebra used earlier in the literature for investigation of
spontaneous supersymmetry breaking. We indicate that the observed exotic
supersymmetric structure with three different $\mathbb Z_2$-gradings can be
useful for the search of hidden symmetries in some other quantum systems, in
particular, related to the Lam\'e equation.


title: Running anti-de Sitter radius from QCD-like strings

abstract:
  We consider renormalization effects for a bosonic QCD-like string, whose
partons have $1/p^{2}$ propagators instead of Gaussian. Classically this model
resembles (the bosonic part of) the projective light-cone (zero-radius) limit
of a string on an AdS${}_5$ background, where Schwinger parameters give rise to
the fifth dimension. Quantum effects generate dynamics for this dimension,
producing an AdS${}_5$ background with a running radius. The projective
light-cone is the high-energy limit: Holography is enforced dynamically.


title:
Continuous first-passage percolation and continuous greedy paths model:
  linear growth

abstract:
  We study a random growth model on $\R^d$ introduced by Deijfen. This is a
continuous first-passage percolation model. The growth occurs by means of
spherical outbursts with random radii in the infected region. We aim at finding
conditions on the distribution of the random radii to determine whether the
growth of the process is linear or not. To do so, we compare this model with a
continuous analogue of the greedy lattice paths model and transpose results in
the lattice setting to the continuous setting.


title:
Induced cosmology on a regularized brane in six-dimensional flux
  compactification

abstract:
  We consider a six-dimensional Einstein-Maxwell system compactified in an
axisymmetric two-dimensional space with one capped regularized conical brane of
codimension one. We study the cosmological evolution which is induced on the
regularized brane as it moves in between known static bulk and cap solutions.
Looking at the resulting Friedmann equation, we see that the brane cosmology at
high energies is dominated by a five-dimensional rho^2 energy density term. At
low energies, we obtain a Friedmann equation with a term linear to the energy
density with, however, negative coefficient in the small four-brane radius
limit (i.e. with negative effective Newton's constant). We discuss ways out of
this problem.


title:
Mid-infrared diagnostics of starburst galaxies: clumpy, dense structures
  in star-forming regions in the Antennae (NGC 4038/4039)

abstract:
  Recently, mid-infrared instruments have become available on several large
ground-based telescopes, resulting in data sets with unprecedented spatial
resolution at these long wavelengths. In this paper we examine
'ground-based-only' diagnostics, which can be used in the study of star-forming
regions in starburst galaxies. By combining output from the stellar population
synthesis code Starburst 99 with the photoionization code Mappings, we model
stellar clusters and their surrounding interstellar medium, focusing on the
evolution of emission lines in the N- and Q-band atmospheric windows (8-13 and
16.5-24.5 micron respectively) and those in the near-infrared. We address the
detailed sensitivity of various emission line diagnostics to stellar population
age, metallicity, nebular density, and ionization parameter. Using our model
results, we analyze observations of two stellar clusters in the overlap region
of the Antennae galaxies obtained with VLT Imager and Spectrometer for mid
Infrared (VISIR). We find evidence for clumpy, high density, ionized gas. The
two clusters are young (younger than 2.5 and 3 Myr respectively), the
surrounding interstellar matter is dense (10^4 cm^-3 or larger) and can be
characterized by a high ionization parameter (logU > -1.53). Detailed analysis
of the mid-infrared spectral features shows that a (near-)homogeneous medium
cannot account for the observations, and that complex structure on scales below
the resolution limit, containing several young stellar clusters embedded in
clumpy gas, is more likely.


title:
Experimental studies of liquid-liquid dispersion in a turbulent shear
  flow

abstract:
  We study liquid-liquid dispersions in a turbulent Taylor - Couette flow,
produced between two counterrotating coaxial cylinders. In pure Water and in
counterrotation, Reynolds numbers up to 1.4 10^5 are reached. We first
characterize the single-phase flow, in terms of threshold for transition to
turbulence, scaling of the torque and measurements of the mean flow and of the
Reynolds stress by stereoscopic PIV. We then study the increase of the
dissipation in the two-phase flows and find that the torque per unit mass can
be twice the torque for a single-phase flow. Long-time behaviours are also
reported.


title: Detection of SiO emission from a massive dense cold core

abstract:
  We report the detection of the SiO (J = 2 - 1) transition from the massive
cold dense core G333.125-0.562. The core remains undetected at wavelengths
shorter than 70 micron and has compact 1.2 mm dust continuum. The SiO emission
is localised to the core. The observations are part of a continuing
multi-molecular line survey of the giant molecular cloud G333. Other detected
molecules in the core include 13CO, C18O, CS, HCO+, HCN, HNC, CH3OH, N2H+, SO,
HC3N, NH3, and some of their isotopes. In addition, from NH3 (1,1) and (2,2)
inversion lines, we obtain a temperature of 13 K. From fitting to the spectral
energy distribution we obtain a colour temperature of 18 K and a gas mass of 2
x 10^3 solar mass. We have also detected a 22 GHz water maser in the core,
together with methanol maser emission, suggesting the core will host massive
star formation. We hypothesise that the SiO emission arises from shocks
associated with an outflow in the cold core.


title:
Lower bounds for sup + inf and sup * inf and an Extension of Chen-Lin
  result in dimension 3

abstract:
  We give two results about Harnack type inequalities. First, on compact smooth
Riemannian surface without boundary, we have an estimate of the type $\sup
+\inf$. The second result concerns the solutions of prescribed scalar curvature
equation on the unit ball of ${\mathbb R}^n$ with Dirichlet condition. Next, we
give an inequality of the type $(\sup_K u)^{2s-1} \times \inf_{\Omega} u \leq
c$ for positive solutions of $\Delta u=Vu^5$ on $\Omega \subset {\mathbb R}^3$,
where $K$ is a compact set of $\Omega$ and $V$ is $s-$ h\"olderian, $s\in
]-1/2,1]$. For the case $s=1/2$, we prove that if $\min_{\Omega} u>m>0$ and the
h\"olderian constant $A$ of $V$ is small enough (in certain meaning), we have
the uniform boundedness of the supremum of the solutions of the previous
equation on any compact set of $\Omega$.
  -----
  Nous donnons quelques estimations des solutions d'equations elliptiques sur
les surfaces de Riemann et sur des ouverts en dimension n> 2. Nous traitons le
cas holderien pour l'equation de la courbure scalaire prescrite en dimension 3.


title: Complete Two-Loop Corrections to H -> gamma gamma

abstract:
  In this paper the complete two-loop corrections to the Higgs-boson decay, H
-> gamma gamma, are presented. The evaluations of both QCD and electroweak
corrections are based on a numerical approach. The results cover all
kinematical regions, including the WW normal-threshold, by introducing complex
masses in the relevant (gauge-invariant) parts of the LO and NLO amplitudes.


title:
Construction and test of a moving boundary model for negative streamer
  discharges

abstract:
  Starting from the minimal model for the electrically interacting particle
densities in negative streamer discharges, we derive a moving boundary
approximation for the ionization fronts. The boundary condition on the moving
front is found to be of 'kinetic undercooling' type. The boundary
approximation, whose first results have been published in [Meulenbroek et al.,
PRL 95, 195004 (2005)], is then tested against 2-dimensional simulations of the
density model. The results suggest that our moving boundary approximation
adequately represents the essential dynamics of negative streamer fronts.


title:
Accretion of Low Angular Momentum Material onto Black Holes: Radiation
  Properties of Axisymmetric MHD Flows

abstract:
  Numerical simulations of MHD accretion flows in the vicinity of a
supermasssive black hole provide important insights to the problem of why and
how systems -- such as the Galactic Center -- are underluminous and variable.
To access applicability of such flows to real objects, we examine the dynamical
MHD studies with computations of the time dependent radiation spectra predicted
by the simulations. We apply Monte Carlo methods to calculate spectra predicted
by the time-dependent model of an axisymmetic MHD flow accreting onto a black
hole presented by Proga and Begelman. Our calculations show that variability in
an accretion flow is not always reflected in the corresponding spectra, at
least not in all wavelengths. We find no one-to-one correspondence between the
accretion state and the predicted spectrum


title: Corings with exact rational functors and injective objects

abstract:
  We describe how some aspects of abstract localization on module categories
have applications to the study of injective comodules over some special types
of corings. We specialize the general results to the case of Doi-Koppinen
modules, generalizing previous results in this setting.


title: Symmetries of Electrostatic Interaction between DNA Molecules

abstract:
  We study a model for pair interaction $U$ of DNA molecules generated by the
discrete dipole moments of base-pairs and the charges of phosphate groups, and
find noncommutative group of eighth order ${\cal S}$ of symmetries that leave
$U$ invariant. We classify the minima using group ${\cal S}$ and employ
numerical methods for finding them. The minima may correspond to several
cholesteric phases, as well as phases formed by cross-like conformations of
molecules at an angle close to $\rm{90}^{o}$, "snowflake phase". The results
depend on the effective charge $Q$ of the phosphate group which can be modified
by the polycations or the ions of metals. The snowflake phase could exist for
$Q$ above the threshold $Q_C$. Below $Q_C$ there could be several cholesteric
phases. Close to $Q_C$ the snowflake phase could change into the cholesteric
one at constant distance between adjacent molecules.


title:
Uniqueness at infinity in time for the Maxwell-Schr"odinger system with
  arbitrarily large asymptotic data

abstract:
  We prove the uniqueness of solutions of the Maxwell-Schr"odinger system with
given asymptotic behaviour at infinity in time. The assumptions include
suitable restrictions on the growth of solutions for large time and on the
accuracy of their asymptotics, but no restriction on their size. The result
applies to the solutions with prescribed asymptotics constructed in a previous
paper.


title: Reliability of genetic networks is evolvable

abstract:
  Control of the living cell functions with remarkable reliability despite the
stochastic nature of the underlying molecular networks -- a property presumably
optimized by biological evolution. We here ask to what extent the property of a
stochastic dynamical network to produce reliable dynamics is an evolvable
trait. Using an evolutionary algorithm based on a deterministic selection
criterion for the reliability of dynamical attractors, we evolve dynamical
networks of noisy discrete threshold nodes. We find that, starting from any
random network, reliability of the attractor landscape can often be achieved
with only few small changes to the network structure. Further, the evolvability
of networks towards reliable dynamics while retaining their function is
investigated and a high success rate is found.


title: Module Shifts and Measure Rigidity in Linear Cellular Automata

abstract:
  Suppose R is a finite commutative ring of prime characteristic, A is a finite
R-module, M:=Z^D x N^E, and F is an R-linear cellular automaton on A^M. If mu
is an F-invariant measure which is multiply shift-mixing in a certain way, then
we show that mu must be the Haar measure on a coset of some submodule shift of
A^M. Under certain conditions, this means mu must be the uniform Bernoulli
measure on A^M.


title: Poisson-Vlasov : Stochastic representation and numerical codes

abstract:
  A stochastic representation for the solutions of the Poisson-Vlasov equation,
with several charged species, is obtained. The representation involves both an
exponential and a branching process and it provides an intuitive
characterization of the nature of the solutions and its fluctuations. Here, the
stochastic representation is also proposed as a tool for the numerical
evaluation of the solutions


title:
The quadratic speedup in Grover's search algorithm from the entanglement
  perspective

abstract:
  We analyze the role played by entanglement in the dynamical evolution of
Grover's search algorithm in the space of qubits. We show that the algorithm
can be equivalently described as an iterative change of the entanglement
between the qubits, which governs the evolution of the initial state towards
the target state, and where the entanglement can be quantified in terms a
single entanglement monotone. We also provide a necessary and sufficient
condition for the quadratic speedup, which illustrates how the change in the
bipartite entanglement of the state after each iteration determines the
corresponding increase in the probability of finding the target state. This
allows us to reestablish from the entanglement perspective that Grover's search
algorithm is the only optimal pure state search algorithm.


title: Constructing Simplicial Branched Covers

abstract:
  Branched covers are applied frequently in topology - most prominently in the
construction of closed oriented PL d-manifolds. In particular, strong bounds
for the number of sheets and the topology of the branching set are known for
dimension d<=4. On the other hand, Izmestiev and Joswig described how to obtain
a simplicial covering space (the partial unfolding) of a given simplicial
complex, thus obtaining a simplicial branched cover [Adv. Geom. 3(2):191-255,
2003]. We present a large class of branched covers which can be constructed via
the partial unfolding. In particular, for d<=4 every closed oriented PL
d-manifold is the partial unfolding of some polytopal d-sphere.


title: On natural and conformally equivariant quantizations

abstract:
  The concept of conformally equivariant quantizations was introduced by Duval,
Lecomte and Ovsienko in \cite{DLO} for manifolds endowed with flat conformal
structures. They obtained results of existence and uniqueness (up to
normalization) of such a quantization procedure. A natural generalization of
this concept is to seek for a quantization procedure, over a manifold $M$, that
depends on a pseudo-Riemannian metric, is natural and is invariant with respect
to a conformal change of the metric. The existence of such a procedure was
conjectured by P. Lecomte in \cite{Leconj} and proved by C. Duval and V.
Ovsienko in \cite{DO1} for symbols of degree at most 2 and by S. Loubon Djounga
in \cite{Loubon} for symbols of degree 3. In two recent papers \cite{MR,MR1},
we investigated the question of existence of projectively equivariant
quantizations using the framework of Cartan connections. Here we will show how
the formalism developed in these works adapts in order to deal with the
conformally equivariant quantization for symbols of degree at most 3. This will
allow us to easily recover the results of \cite{DO1} and \cite{Loubon}. We will
then show how it can be modified in order to prove the existence of conformally
equivariant quantizations for symbols of degree 4.


title: Minimizing the linewidth of the Flux-Flow Oscillator

abstract:
  For the first time the linewidth of Flux-Flow Oscillator has been calculated
by direct computer simulation of the sine-Gordon equation with noise. Nearly
perfect agreement of the numerical results with the formula derived in [Phys.
Rev. B, {\bf 65}, 054504 (2002)] has been achieved. It has been demonstrated
that for homogeneous bias current distribution the linewidth actually does not
depend on the junction length for practically interesting parameters range.
Depending on the length of the unbiased tail, the power may be maximized and
the linewidth may be minimized in a broad range of bias currents. The linewidth
can be decreased further by 1.5 times by proper load matching.


title:
Experimental studies of turbulent Taylor-Couette flows: single phase and
  liquid-liquid dispersions

abstract:
  We study liquid-liquid dispersions in a turbulent Taylor-Couette flow,
produced between two counterrotating coaxial cylinders. In pure Water and in
counterrotation, Reynolds numbers up to 1.4 10^5 are reached. The liquids we
use are a low-viscous Oil and pure Water or a Sodium Iodide solution with a
refractive index matched to that of Oil, in order to get transparent
dispersions. We first characterize the single-phase flow, in terms of threshold
for transition to turbulence, scaling of the torque and measurements of the
mean flow and of the Reynolds stress by stereoscopic PIV. We then study the
increase of the dissipation in the two-phase flows and find that the torque per
unit mass can be twice the torque for a single-phase flow. Long-time behaviours
are also reported.


title: Constructing Combinatorial 4-Manifolds

abstract:
  Every closed oriented PL 4-manifold is a branched cover of the 4-sphere
branched over a PL-surface with finitely many singularities by Piergallini
[Topology 34(3):497-508, 1995]. This generalizes a long standing result by
Hilden and Montesinos to dimension four. Izmestiev and Joswig [Adv. Geom.
3(2):191-225, 2003] gave a combinatorial equivalent of the Hilden and
Montesinos result, constructing closed oriented combinatorial 3-manifolds as
simplicial branched covers of combinatorial 3-spheres. The construction of
Izmestiev and Joswig is generalized and applied to the result of Piergallini,
obtaining closed oriented combinatorial 4-manifolds as simplicial branched
covers of simplicial 4-spheres.


title:
The Impact of Ultraviolet Regularization on the Spectrum of Curvature
  Perturbations During Inflation

abstract:
  Inflationary predictions based on the linear theory of cosmological
perturbations are related to the two point function of a (second quantized)
real scalar free field during the accelerated stage. Such a two point function
is finite, in contrast with its coincidence limit, which is divergent due to
the ultraviolet divergences proper of field theory. We therefore argue that
predictions of most of the inflationary models do not necessarily need a
regularization scheme to leading order, i.e. tree level, which is required
instead for non-linear corrections or calculations involving the
energy-momentum tensor. We also discuss unpleasant features of the "would be"
regularized spectrum obtained using the traditional fourth order adiabatic
subtraction.


title: Characteristic Functions of Liftings

abstract:
  We introduce characteristic functions for certain contractive liftings of row
contractions. These are multi-analytic operators which classify the liftings up
to unitary equivalence and provide a kind of functional model. The most
important cases are subisometric and coisometric liftings. We also identify the
most general setting which we call reduced liftings. We derive properties of
these new characteristic functions and discuss the relation to Popescu's
definition for completely non-coisometric row contractions. Finally we apply
our theory to completely positive maps and prove a one-to-one correspondence
between the fixed point sets of completely positive maps related to each other
by a subisometric lifting.


title: On the transformation semitopological semigroup

abstract:
  In this paper we introduce the notion of weighted (weakly) almost periodic
compactifcation of a semitopological semigroup and generalize this notion to
corresponding notion for transformation semigroup.The inclusion relation and
equality of some well known function spaces on a weighted transformation
semigroup is also investigated.


title: Unparticle as a field with continuously distributed mass

abstract:
  We point out that the notion of an unparticle, recently introduced by Georgi,
can be interpreted as a particular case of a field with continuously
distributed mass considered in ref.\cite{14}. We also point out that the
simplest renormalizable extension of the $SU_c(3)\otimes SU_L(2)\otimes U(1)$
Standard Model is the extension with the replacement of the U(1) gauge
propagator $\frac{1}{k^2} \to \frac{1}{k^2} + \int
_0^{\infty}\frac{\rho(t)}{-t+k^2 +i\epsilon}dt$ with $\int_0^{\infty}\rho(t)dt
< \infty $.


title: Parastrophic invariance of Smarandache quasigroups

abstract:
  Every quasigroup $(L,\cdot)$ belongs to a set of 6 quasigroups, called
parastrophes denoted by $(L,\pi_i)$, $i\in \{1,2,3,4,5,6\}$. It is shown that
$(L,\pi_i)$ is a Smarandache quasigroup with associative subquasigroup
$(S,\pi_i) \forall i\in \{1,2,3,4,5,6\}$ if and only if for any of some four
$j\in \{1,2,3,4,5,6\}$, $(S,\pi_j)$ is an isotope of $(S,\pi_i)$ or $(S,\pi_k)$
for one $k\in \{1,2,3,4,5,6\}$ such that $i\ne j\ne k$. Hence, $(L,\pi_i)$ is a
Smarandache quasigroup with associative subquasigroup $(S,\pi_i) \forall i\in
\{1,2,3,4,5,6\}$ if and only if any of the six Khalil conditions is true for
any of some four of $(S,\pi_i)$.


title: Consequences of U dualities for Intersecting Branes in the Universe

abstract:
  We consider N -- charge, intersecting brane antibrane configurations in M
theory which are smeared uniformly in the common transverse space and may
describe our universe. We study the consequences of U dualities and find that
they imply relations among the scale factors. We find using Einstein's
equations that U dualities also imply a relation among the density \rho and the
pressure p_i for the single charge case. We present an ansatz for \rho and p_i
for the N -- charge case which yields all the U duality relations among the
scale factors. We then study configurations with identical charges, and also
with net charges vanishing. We find among other things that, independent of the
details of the brane antibrane dynamics, such four charge configurations lead
asymptotically to an effective (3 + 1) -- dimensional expanding universe.


title: Alpha-prime corrections to space-like branes

abstract:
  Space-like branes or S-branes are certain class of time dependent solutions
of M/string theories having isometries ISO(p+1) $\times$ SO(d-p-2,1), where
$d=11,10$ respectively and have singularities at t=0. In \cite{Roy:2006du}, we
found that the asymptotically flat S-branes have the structure of generalized
Kasner geometry near t=0. In this work we evaluate higher order $\alpha'$
corrections perturbatively to the heterotic string Kasner backgrounds to probe
the singularity at t=0. We generally find that the perturbative corrections do
not permit us to reach the singular point, as the supergravity framework fails
near $t \sim {\sqrt \alpha'}$ blurring the origin of space-like singularities.
This is analogous to the concept of stretched horizons in the case of black
holes.


title: Smarandache Isotopy Theory Of Smarandache: Quasigroups And Loops

abstract:
  The concept of Smarandache isotopy is introduced and its study is explored
for Smarandache: groupoids, quasigroups and loops just like the study of
isotopy theory was carried out for groupoids, quasigroups and loops. The
exploration includes: Smarandache; isotopy and isomorphy classes, Smarandache
$f,g$ principal isotopes and G-Smarandache loops.


title: Pion scattering poles and chiral symmetry restoration

abstract:
  Using unitarized Chiral Perturbation Theory methods, we perform a detailed
analysis of the $\pi\pi$ scattering poles $f_0(600)$ and $\rho(770)$ behaviour
when medium effects such as temperature or density drive the system towards
Chiral Symmetry Restoration. In the analysis of real poles below threshold, we
show that it is crucial to extend properly the unitarized amplitudes so that
they match the perturbative Adler zeros. Our results do not show threshold
enhancement effects at finite temperature in the $f_0(600)$ channel, which
remains as a pole of broad nature. We also implement T=0 finite density effects
related to chiral symmetry restoration, by varying the pole position with the
pion decay constant. Although this approach takes into account only a limited
class of contributions, we reproduce the expected finite density restoration
behaviour, which drives the poles towards the real axis, producing threshold
enhancement and $\pi\pi$ bound states. We compare our results with several
model approaches and discuss the experimental consequences, both in
Relativistic Heavy Ion Collisions and in $\pi\to \pi\pi$ and $\gamma\to \pi\pi$
reactions in nuclei.


title: How light can the lightest neutralino be?

abstract:
  We show that in the Minimal Supersymmetric Standard Model, the mass of the
lightest neutralino is experimentally unconstrained if the GUT relation between
the gaugino mass parameters M_1 and M_2 is dropped. We discuss what the impact
of light or massless neutralinos would be on their production at LEP, as well
as on electroweak precision data and rare decays.


title:
Cosmological evolution of regularized branes in 6D warped flux
  compactifications

abstract:
  We study the cosmological evolution of extended branes in 6D warped flux
compactification models. The branes are endowed with the three ordinary spatial
dimensions, which are assumed to be homogeneous and isotropic, as well as an
internal extra dimension compactified on a circle. We embed these codimension 1
branes in a static bulk 6D spacetime, whose geometry is a solution of 6D
Einstein-Maxwell or Einstein-Maxwell-dilaton theories, corresponding to a
warped flux compactification. The brane matter consists of a complex scalar
field which is coupled to the bulk U(1) gauge field. In both models, we show
that there is critical point which the brane cannot cross as it moves in the
bulk. We study the cosmological behaviour, especially when the brane approaches
this critical point or one of the two conical singularities. In the present
setup where the bulk geometry is fixed, we find that the brane cosmology does
not coincide with the standard one in the low energy limit.


title:
Analytic perturbation theory versus 1/N expansion in the Gross-Neveu
  model

abstract:
  The 1/N expansion can be successfully used to calculate the Green functions
of the two-dimensional O(2N) Gross - Neveu model. In parallel, the methods of
analytic perturbation theory are also applied. Comparing the results of these
two calculations at leading order, we report on the surprising agreement
between them.


title:
Development of CaMoO4 crystal scintillators for double beta decay
  experiment with 100-Mo

abstract:
  Energy resolution, alpha/beta ratio, pulse-shape discrimination for gamma
rays and alpha particles, temperature dependence of scintillation properties,
and radioactive contamination were studied with CaMoO4 crystal scintillators. A
high sensitivity experiment to search for neutrinoless double beta decay of
100-Mo by using CaMoO4 scintillators is discussed.


title: Tangential projections and secant defective varieties

abstract:
  Going one step further in Zak's classification of Scorza varieties with
secant defect equal to one, we characterize the Veronese embedding of $\P^n$
given by the complete linear system of quadrics and its smooth projections from
a point as the only smooth irreducible complex and non-degenerate projective
subvarieties of $\P^N$ that can be projected isomorphically into $\P^{2n}$ when
$N\geq\binom{n+2}{2}-2$.


title: On the Derivatives of Central Loops

abstract:
  The right(left) derivative, $a^{-1},e-$ and $e,a^{-1}-$ isotopes of a C-loop
are shown to be C-loops. Furthermore, for a central loop $(L,F)$, it is shown
that $\big\{F,F^{a^{-1}},F_{a^{-1},e}\big\}$ and
$\big\{F,F_{a^{-1}},F_{e,a^{-1}}\big\}$ are systems of isotopic C-loops that
obey a form of generalized distributive law. Quasigroup isotopes $(L,\otimes)$
and $(L,\ominus)$ of a loop $(L,\theta)$ and its parastrophe $(L,\theta ^*)$
respectively are proved to be isotopic if either $(L,\otimes)$ or $(L,\ominus
)$ is commutative. If $(L,\theta)$ is a C-loop, then it is shown that
$\big\{(L,\theta),(L,\theta ^*),(L,\otimes),(L,\oplus)\big\}$ is a system of
isotopic C-quasigroup under the above mentioned condition. It is shown that
C-loops are isotopic to some finite indecomposable groups of the classes ${\cal
D}_i,i=1,2,3,4,5$ and that the center of such C-loops have a rank of 1,2 or 3.


title: Gravitational Field of Spherical Branes

abstract:
  The warped solution of Einstein's equations corresponding to the spherical
brane in five-dimensional AdS is considered. This metric represents interiors
of black holes on both sides of the brane and can provide gravitational
trapping of physical fields on the shell. It is found the analytic form of the
coordinate transformations from the Schwartschild to co-moving frame that
exists only in five dimensions. It is shown that in the static coordinates
active gravitational mass of the spherical brane, in agreement with Tolman's
formula, is negative, i.e. such objects are gravitationally repulsive.


title: Sequential products in effect categories

abstract:
  A new categorical framework is provided for dealing with multiple arguments
in a programming language with effects, for example in a language with
imperative features. Like related frameworks (Monads, Arrows, Freyd
categories), we distinguish two kinds of functions. In addition, we also
distinguish two kinds of equations. Then, we are able to define a kind of
product, that generalizes the usual categorical product. This yields a powerful
tool for deriving many results about languages with effects.


title: Population III stars: hidden or disappeared ?

abstract:
  A PopIII/Pop II transition from massive to normal stars is predicted to occur
when the metallicity of the star forming gas crosses the critical range Z_cr =
10^(-5 +/- 1) Z_sun. To investigate the cosmic implications of such process we
use numerical simulations which follow the evolution, metal enrichment and
energy deposition of both Pop III and Pop II stars. We find that: (i) due to
inefficient heavy element transport by outflows and slow "genetic" transmission
during hierarchical growth, large fluctuations around the average metallicity
arise; as a result Pop III star formation continues down to z=2.5, but at a low
peak rate of 10^-5 M_sun yr^-1 Mpc^-3 occurring at z~6 (about 10^-4 of the
PopII one); (ii) Pop III star formation proceeds in a "inside-out" mode in
which formation sites are progressively confined at the periphery of collapsed
structures, where the low gas density and correspondingly long free-fall
timescales result in a very inefficient astration. These conclusions strongly
encourage deep searches for pristine star formation sites at moderate (2<z<5)
redshifts where metal free stars are likely to be hidden.


title:
Spectroscopy, upconversion dynamics, and applications of Er3+-doped
  low-phonon materials

abstract:
  In this work I summarize some of the recent work carried out by our group on
the upconversion dynamics of Er3+-doped potassium lead halide crystals, which
possess very small phonons and present very efficient blue and green
upconversion. Furthermore, a non-conventional application of these RE-doped
low-phonon materials in optical refrigeration of luminescent solids is also
discussed, paying especial attention to new pathways for optical cooling that
include infrared-to-visible upconversion. Finally, I conclude with some hints
of what I think it is the next step into improving the luminescence efficiency
of solids: the use of RE-doped nanoscale photonic heterostructures for
controlling the density of photonic states.


title: On Isotopic Characterization of Central Loops

abstract:
  The representation sets of central loops are investigated and the results
obtained are used to construct a finite C-loop. It is shown that for certain
types of isotopisms, the central identities are isotopic invariant.


title: The collective dynamics of self-propelled particles

abstract:
  We have proposed a method for the dynamic simulation of a collection of
self-propelled particles in a viscous Newtonian fluid. We restrict attention to
particles whose size and velocity are small enough that the fluid motion is in
the creeping flow regime. We have proposed a simple model for a self-propelled
particle, and extended the Stokesian Dynamics method to conduct dynamic
simulations of a collection of such particles. In our description, each
particle is treated as a sphere with an orientation vector $\te{p}$, whose
locomotion is driven by the action of a force dipole at a point slightly
displaced from its centre. In isolation, a self-propelled particle moves at a
constant speed in the direction of $\te{p}$. When it coexists with many such
particles, its hydrodynamic interaction with the other particles alters its
velocity and, more importantly, its orientation. As a result, the motion of the
particle is chaotic. Our simulations are not restricted to low particle
concentration, as we implement the full hydrodynamic interactions between the
particles, but we restrict the motion of particles to two dimensions to reduce
computation. We report the statistical properties of a suspension of
self-propelled particles, such as the distribution of particle velocity, the
pair correlation function and the orientation correlation function, for a range
of the particle concentration.


title: Detrended Fluctuation Analysis of Autoregressive Processes

abstract:
  Autoregressive processes (AR) have typical short-range memory. Detrended
Fluctuation Analysis (DFA) was basically designed to reveal long range
correlation in non stationary processes. However DFA can also be regarded as a
suitable method to investigate both long-range and short range correlation in
non-stationary and stationary systems. Applying DFA to AR processes can help
understanding the non uniform correlation structure of such processes. We
systematically investigated a first order autoregressive model AR(1) by DFA and
established the relationship between the interaction constant of AR(1) and the
DFA correlation exponent. The higher the interaction constant the higher is the
short range correlation exponent. They are exponentially related. The
investigation was extended to AR(2) processes. The presence of a distant
positive interaction in addition to a near by interaction will increase the
correlation exponent and the range of correlation while the effect of a distant
negative interaction will decrease significantly only the range of interaction.
This analysis demonstrate the possibility to identify and AR(1) model in an
unknown DFA plot or to distinguish among AR(1) and AR(2) models. The analysis
was performed on medium long series of 1000 terms.


title: On Some Autotopisms Of Non-Steiner Central Loops

abstract:
  An algebraic process for the construction of an autotopism for a non-Steiner
C-loop is described and this is demonstrated with an example using a known
finite C-loop. In every C-loop, two of its parastrophes are not
equivalent(equal) it, if and only if both the first and second components of
the constructed autotopism and its inverse autotopism are not equal to the
identity map. Hence, none of the other three parastrophes is equivalent(equal)
to the C-loop. It is proved that the set of autotopisms that prevent a C-loop
from being a Steiner loop forms a Steiner triple system.


title: Using a phase space cross section to study large complex systems

abstract:
  For large coupled nonlinear systems, it is difficult to visualize the
high-dimensional phase space, which has been thoroughly studied in smaller
systems with regards to phenomena such as riddled basins. Here we propose a
method to reduce the phase space by defining a phase space cross section. The
method is applied to a system of dynamically coupled maps introduced by Ito &
Kaneko (Phys. Rev. Lett., 88, 028701, 2001 & Phys. Rev. E, 67, 046226, 2003).
We show that the transitions between phases of different synchronization
behaviour are not always sharp but can be characterized by fractal boundaries
in both phase and parameter space.


title: Stability of Salpeter Solutions

abstract:
  In the framework of instantaneous approximations to the Bethe-Salpeter
formalism for the description of bound states within quantum field theories,
depending on the Lorentz structure of the Bethe-Salpeter interaction kernel the
solutions of the full Salpeter equation with some confining interaction may
exhibit certain instabilities, which are possibly related to the Klein paradox
and signal the decay of states assumed to be bound by the confining
interactions. They are observed in numerical (variational) studies of the
Salpeter equation. The presumably simplest scenario allowing for the fully
analytic investigation of this problem is set by the reduced Salpeter equation
with harmonic-oscillator interaction. In this case, Salpeter's integral
equation simplifies to either an algebraic relation or a second-order
homogeneous linear ordinary differential equation, immediately accessible to
standard techniques. There one may hope to be able to decide unambiguously
whether this setting poses a well-defined eigenvalue problem the solutions of
which correspond to stable bound states associated to real energy eigenvalues
bounded from below. By analytical spectral analysis the bound-state solutions
of this "harmonic-oscillator reduced Salpeter equation" can be shown to be free
of such instabilities.


title: On central loops and the central square property

abstract:
  The representation sets of a central square C-loop are investigated. Isotopes
of central square C-loops of exponent 4 are shown to be both C-loops and
A-loops.


title: Embedded metal cluster in strong laser fields

abstract:
  We discuss microscopic mechanisms of the violent dynamics following strong
laser excitation of a metal cluster embedded in a rare gas matrix, taking as
test case Na$_8$@Ar$_434$. This covers at least two aspects : first, it
represents the typical experimental situation of metal clusters handled in
raregas matrices or a finite drop of surrounding raregas material, and second,
it serves as a generic test case for highly excited chromophores in inert
surroundings addressing questions of energy transport and perturbation of the
medium. We simulate the process up to 10 ps using a mixed quantum mechanical
(for the electrons) and classical (ions and atoms) approach and analyze the
emerging dynamics with respect to all basic constituents : cluster electrons,
cluster ions, and matrix atoms. We find several stages of relaxation taking
place with time scales from a few fs to over a few ps and much slower processes
remaining for long after the simulation. A particularly interesting aspect is
that the surrounding raregas material stabilizes a highly charged metal cluster
which would otherwise explode without delay.


title: Jet Tomography at RHIC

abstract:
  The status of the use of hard probes in heavy ion collisions at RHIC is
reviewed. The discovery of strong jet quenching at RHIC is a major success.
However, in order to make full use of this new phenomenon for full jet emission
tomography of the properties of the collision zone further development is
needed, both experimentally and theoretically.


title: Algebraic properties of some varieties of central loops

abstract:
  Isotopes of C-loops with unique non-identity squares are shown to be both
C-loops and A-loops. The relationship between C-loops and Steiner loops is
further studied. Central loops with the weak and cross inverse properties are
also investigated. C-loops are found to be Osborn loops if every element in
them are squares.


title: Invariant measure for a three dimensional nonlinear wave equation

abstract:
  We study the long time behavior of the subcritical (subcubic) defocussing
nonlinear wave equation on the three dimensional ball, for random data of low
regularity. We prove that for a large set of radial initial data in
$\cap_{s<1/2} H^s(B(0,1))$ the equation is (globally in time) well posed and we
construct an invariant measure.


title:
Excitations and superfluidity in non-equilibrium Bose-Einstein
  condensates of exciton-polaritons

abstract:
  We present a generic model for the description of non-equilibrium
Bose-Einstein condensates, suited for the modelling of non-resonantly pumped
polariton condensates in a semiconductor microcavity. The excitation spectrum
and scattering of the non-equilibrium condensate with a defect are discussed.


title:
Random data Cauchy theory for supercritical wave equations I: Local
  theory

abstract:
  We study the local existence of strong solutions for the cubic nonlinear wave
equation with data in $H^s(M)$, $s<1/2$, where $M$ is a three dimensional
compact riemannian manifold. This problem is supercritical and can be shown to
be strongly ill-posed (in the Hadamard sense). However, after a suitable
randomization, we are able to construct local strong solution for a large set
of initial data in $H^s(M)$, where $s\geq 1/4$ in the case of a boundary less
manifold and $s\geq 8/21$ in the case of a manifold with boundary.


title:
Random data Cauchy theory for supercritical wave equations II : A global
  existence result

abstract:
  We prove that the subquartic wave equation on the three dimensional ball
$\Theta$, with Dirichlet boundary conditions admits global strong solutions for
a large set of random supercritical initial data in $\cap_{s<1/2} H^s(\Theta)$.
We obtain this result as a consequence of a general random data Cauchy theory
for supercritical wave equations developed in our previous work \cite{BT2} and
invariant measure considerations which allow us to obtain also precise large
time dynamical informations on our solutions.


title: Abstract homotopical methods for theoretical computer science

abstract:
  The purpose of this paper is to collect the homotopical methods used in the
development of the theory of flows initialized by author's paper ``A model
category for the homotopy theory of concurrency''. It is presented
generalizations of the classical Whitehead theorem inverting weak homotopy
equivalences between CW-complexes using weak factorization systems. It is also
presented methods of calculation of homotopy limits and homotopy colimits using
Quillen adjunctions and Reedy categories.


title: Critical Kauffman networks under deterministic asynchronous update

abstract:
  We investigate the influence of a deterministic but non-synchronous update on
Random Boolean Networks, with a focus on critical networks. Knowing that
``relevant components'' determine the number and length of attractors, we focus
on such relevant components and calculate how the length and number of
attractors on these components are modified by delays at one or more nodes. The
main findings are that attractors decrease in number when there are more
delays, and that periods may become very long when delays are not integer
multiples of the basic update step.


title: BFKL equation at finite temperature

abstract:
  We consider the Color Glass Condensate (CGC) at finite temperature, which
would be relevant to the initial condition of relativistic heavy ion collisions
and the energy loss of energetic partons in the quark-gluon plasma. In the weak
source approximation, we derive the thermal BFKL equation. We find that the
thermal effect shows up as a Bose enhancement of the soft gluon emission if the
temperature is high enough to match the light-cone energy of the soft gluons.
This suggests that the saturation regime could be reached sooner than in the
vacuum.


title:
Clusters, Graphs, and Networks for Analysing Internet-Web-Supported
  Communication within a Virtual Community

abstract:
  The proposal is to use clusters, graphs and networks as models in order to
analyse the Web structure. Clusters, graphs and networks provide knowledge
representation and organization. Clusters were generated by co-site analysis.
The sample is a set of academic Web sites from the countries belonging to the
European Union. These clusters are here revisited from the point of view of
graph theory and social network analysis. This is a quantitative and structural
analysis. In fact, the Internet is a computer network that connects people and
organizations. Thus we may consider it to be a social network. The set of Web
academic sites represents an empirical social network, and is viewed as a
virtual community. The network structural properties are here analysed applying
together cluster analysis, graph theory and social network analysis.


title: A matrix formulation for small-x singlet evolution

abstract:
  We propose a matrix evolution equation in (x,kt)-space for flavour singlet,
unintegrated quark and gluon densities, which generalizes DGLAP and BFKL
equations in the relevant limits. The matrix evolution kernel is constructed so
as to satisfy renormalization group constraints in both the ordered and
antiordered regions of exchanged momenta kt, and incorporates the known NLO
anomalous dimensions in the MSbar scheme as well as the NLx BFKL kernel. We
provide a hard Pomeron exponent and effective eigenvalue functions that include
the n_f-dependence, and give also the matrix of resummed DGLAP splitting
functions. The results connect smoothly with those of the single-channel
approach. The novel P_{qa} splitting functions show resummation effects delayed
down to x=0.0001, while both P_{ga} entries show a shallow dip around x=0.001,
similarly to the gluon-gluon single-channel results. We remark that the matrix
formulation poses further constraints on the consistency of a BFKL framework
with the MSbar scheme, which are satisfied at NLO, but marginally violated by
small n_f/N_c^2-suppressed terms at NNLO.


title: Algorithms for entanglement renormalization

abstract:
  We describe an iterative method to optimize the multi-scale entanglement
renormalization ansatz (MERA) for the low-energy subspace of local Hamiltonians
on a D-dimensional lattice. For translation invariant systems the cost of this
optimization is logarithmic in the linear system size. Specialized algorithms
for the treatment of infinite systems are also described. Benchmark simulation
results are presented for a variety of 1D systems, namely Ising, Potts, XX and
Heisenberg models. The potential to compute expected values of local
observables, energy gaps and correlators is investigated.


title: Supersymmetry Searches at the Tevatron

abstract:
  CDF and DO detectors have already collected 1.3 fb^{-1} of data delivered by
the Tevatron collider at 1.96 TeV center-of-mass energy. We present here the
various analyses that are currently testing the possibility of a supersymmetric
extension of the Standard Model. No evidence for such processes have been found
in luminosities that range from 300 to 800 pb^{-1} and different limits on the
different supersymmetric models are set. Constraints coming from indirect
searches are also presented.


title: The UV Continuum of Quasars: Models and SDSS Spectral Slopes

abstract:
  We measure long (2200-4000 ang) and short (1450-2200 ang) wavelength spectral
slopes \alpha (F_\nu proportional to \nu^\alpha) for quasar spectra from the
Sloan Digital Sky Survey. The long and short wavelength slopes are computed
from 3646 and 2706 quasars with redshifts in the z=0.76-1.26 and z=1.67-2.07
ranges, respectively. We calculate mean slopes after binning the data by
monochromatic luminosity at 2200 ang and virial mass estimates based on
measurements of the MgII line width and 3000 ang continuum luminosity. We find
little evidence for mass dependent variations in the mean slopes, but a
significant luminosity dependent trend in the near UV spectral slopes is
observed with larger (bluer) slopes at higher luminosities. The far UV slopes
show no clear variation with luminosity and are generally lower (redder) than
the near UV slopes at comparable luminosities, suggesting a slightly concave
quasar continuum shape. We compare these results with Monte Carlo distributions
of slopes computed from models of thin accretion disks, accounting for
uncertainties in the mass estimates. The model slopes produce mass dependent
trends which are larger than observed, though this conclusion is sensitive to
the assumed uncertainties in the mass estimates. The model slopes are also
generally bluer than observed, and we argue that reddening by dust intrinsic to
the source or host galaxy may account for much of the discrepancy.


title:
Visibility Fringe Reduction Due to Noise-Induced Effects: Microscopic
  Approach to Interference Experiments

abstract:
  Decoherence is the main process behind the quantum to classical transition.
It is a purely quantum mechanical effect by which the system looses its ability
to exhibit coherent behavior. The recent experimental observation of
diffraction and interference patterns for large molecules raises some
interesting questions. In this context, we identify possible agents of
decoherence to take into account when modeling these experiments and study
theirs visible (or not) effects on the interference pattern. Thereby, we
present an analysis of matter wave interferometry in the presence of a dynamic
quantum environment and study how much the visibility fringe is reduced and in
which timescale the decoherence effects destroy the interference of massive
objects. Finally, we apply our results to the experimental data reported on
fullerenes and cold neutrons.


title:
Explicit computations of all finite index bimodules for a family of II_1
  factors

abstract:
  We study II_1 factors M and N associated with good generalized Bernoulli
actions of groups having an infinite almost normal subgroup with the relative
property (T). We prove the following rigidity result: every finite index
M-N-bimodule (in particular, every isomorphism between M and N) is described by
a commensurability of the groups involved and a commensurability of their
actions. The fusion algebra of finite index M-M-bimodules is identified with an
extended Hecke fusion algebra, providing the first explicit computations of the
fusion algebra of a II_1 factor. We obtain in particular explicit examples of
II_1 factors with trivial fusion algebra, i.e. only having trivial finite index
subfactors.


title: Standard Relations of Multiple Polylogarithm Values at Roots of Unity

abstract:
  Let $N$ be a positive integer. In this paper we shall study the special
values of multiple polylogarithms at $N$th roots of unity, called multiple
polylogarithm values (MPVs) of level $N$. These objects are generalizations of
multiple zeta values and alternating Euler sums, which was studied by Euler,
and more recently, many mathematicians and theoretical physicists.. Our primary
goal in this paper is to investigate the relations among the MPVs of the same
weight and level by using the regularized double shuffle relations, regularized
distribution relations, lifted versions of such relations from lower weights,
and seeded relations which are produced by relations of weight one MPVs. We
call relations from the above four families \emph{standard}. Let $d(w,N)$ be
the $\Q$-dimension of $\Q$-span of all MPVs of weight $w$ and level $N$. Then
we obtain upper bound for $d(w,N)$ by the standard relations which in general
are no worse or no better than the one given by Deligne and Goncharov depending
on whether $N$ is a prime-power or not, respectively, except for 2- and
3-powers, in which case standard relations seem to be often incomplete whereas
Deligne shows that their bound should be sharp by a variant of Grothedieck's
period conjecture. This suggests that in general there should be other linear
relations among MPVs besides the standard relations, some of which are written
down in this paper explicitly with good numerical verification. We also provide
a few conjectures which are supported by our computational evidence.


title:
Structure and Evolution of Giant Cells in Global Models of Solar
  Convection

abstract:
  The global scales of solar convection are studied through three-dimensional
simulations of compressible convection carried out in spherical shells of
rotating fluid which extend from the base of the convection zone to within 15
Mm of the photosphere. Such modelling at the highest spatial resolution to date
allows study of distinctly turbulent convection, revealing that coherent
downflow structures associated with giant cells continue to play a significant
role in maintaining the strong differential rotation that is achieved. These
giant cells at lower latitudes exhibit prograde propagation relative to the
mean zonal flow, or differential rotation, that they establish, and retrograde
propagation of more isotropic structures with vortical character at mid and
high latitudes. The interstices of the downflow networks often possess strong
and compact cyclonic flows. The evolving giant-cell downflow systems can be
partly masked by the intense smaller scales of convection driven closer to the
surface, yet they are likely to be detectable with the helioseismic probing
that is now becoming available. Indeed, the meandering streams and varying
cellular subsurface flows revealed by helioseismology must be sampling
contributions from the giant cells, yet it is difficult to separate out these
signals from those attributed to the faster horizontal flows of
supergranulation. To aid in such detection, we use our simulations to describe
how the properties of giant cells may be expected to vary with depth, how their
patterns evolve in time, and analyze the statistical features of correlations
within these complex flow fields.


title:
Conditional large and moderate deviations for sums of discrete random
  variables. Combinatoric applications

abstract:
  We prove large and moderate deviation principles for the distribution of an
empirical mean conditioned by the value of the sum of discrete i.i.d. random
variables. Some applications for combinatoric problems are discussed.


title: Non-Uniqueness of Gibbs measures relative to Brownian motion

abstract:
  We consider Gibbs measures relative to Brownian motion of Feynman-Kac type,
with single site potential V. We show that for a large class of V, including
the Coulomb potential, there exist infinitely many infinite volume Gibbs
measures.


title: Continuously Crossing u=z in the H3+ Boundary CFT

abstract:
  For AdS boundary conditions, we give a solution of the H3+ two point function
involving degenerate field with SL(2)-label b^{-2}/2, which is defined on the
full (u,z) unit square. It consists of two patches, one for z<u and one for
u<z. Along the u=z "singularity", the solutions from both patches are shown to
have finite limits and are merged continuously as suggested by the work of
Hosomichi and Ribault. From this two point function, we can derive
b^{-2}/2-shift equations for AdS_2 D-branes. We show that discrete as well as
continuous AdS_2 branes are consistent with our novel shift equations without
any new restrictions.


title: The Attractor Mechanism in Gauss-Bonnet Gravity

abstract:
  We study extremal black hole solutions of D=5 Gauss-Bonnet gravity coupled to
a system of gauge and scalar fields. As in Einstein gravity, we find that the
values of the scalar fields on the horizon must extremize a certain effective
potential that depends on the black hole charges. If the matrix of second
derivatives of the effective potential at this extremum has positive
eigenvalues, we give evidence, based on a near horizon perturbative expansion,
that the attractor mechanism continues to hold in this general class of
theories. We numerically construct solutions to a particular simple single
scalar field model that display the attractor mechanism over a wide range of
asymptotic values for the scalar field. We also numerically construct
non-extremal solutions and show that the attractor mechanism fails to hold away
from extremality.


title:
Resonant superradiant backward-scattering as a source for many-particle
  entanglement

abstract:
  We investigate the atom pair production by superradiant backward-scattering
from a Bose-Einstein condensate. By driving the superradiant process with two
frequencies we can extend both the range of pulse duration and intensity by two
orders of magnitude and obtain full control over the number of scattered atoms
in forward and backward direction. We show that the atoms scattered in forward
direction are strongly correlated with the atoms scattered in backward
direction, which makes resonant superradiant backward-scattering a promising
candidate for many-particle entanglement.


title: Coherent systems of genus 0, III: Computation of flips for k=1

abstract:
  In this paper we continue the investigation of coherent systems of type
$(n,d,k)$ on the projective line which are stable with respect to some value of
a parameter $\alpha$. We consider the case $k=1$ and study the variation of the
moduli spaces with $\alpha$. We determine inductively the first and last moduli
spaces and the flip loci, and give an explicit description for ranks 2 and 3.
We also determine the Hodge polynomials explicitly for ranks 2 and 3 and in
certain cases for arbitrary rank.


title:
Electron-phonon coupling and electron self-energy in electron-doped
  graphene: calculation of angular resolved photoemission spectra

abstract:
  We obtain analytical expressions for the electron self-energy and the
electron-phonon coupling in electron-doped graphene using electron-phonon
matrix elements extracted from density functional theory simulations. From the
electron self-energies we calculate angle resolved photoemission spectra. We
demonstrate that the measured kink at $\approx -0.2$ eV from the Fermi level is
actually composed of two features, one at $\approx -0.195$ eV due to the
twofold degenerate E$_{2g}$ mode, and a second one at $\approx -0.16$ eV due to
the A$_{1}^{'}$ mode. The electron-phonon coupling extracted from the kink
observed in ARPES experiments is roughly a factor of 5.5 larger than the
calculated one. This disagreement can only be partially reconciled by the
inclusion of resolution effects. Indeed we show that a finite resolution
increases the apparent electron-phonon coupling by underestimating the
renormalization of the electron velocity at energies larger than the kinks
positions. The discrepancy between theory and experiments is thus reduced to a
factor of $\approx$ 2.2. From the linewidth of the calculated ARPES spectra we
obtain the electron relaxation time. A comparison with available experimental
data in graphene shows that the electron relaxation time detected in ARPES is
almost two orders of magnitudes smaller than what measured by other
experimental techniques.


title: Stable curves and screens on fatgraphs

abstract:
  The mapping class group invariant ideal cell decomposition of the
Teichmueller space of a punctured surface times an open simplex has been used
in a number of computations. This paper answers a question about the
asymptotics of this decomposition, namely, in a given cell of the
decomposition, which curves can be short? Screens are a new combinatorial
structure which provide an answer to this question. The heart of the
calculation here involves Ptolemy transformations and the triangle inequalities
on lambda lengths.


title:
Coarse and synthetic Weil-Petersson geometry: quasi-flats, geodesics,
  and relative hyperbolicity

abstract:
  We analyze the coarse geometry of the Weil-Petersson metric on Teichm\"uller
space, focusing on applications to its synthetic geometry (in particular the
behavior of geodesics). We settle the question of the strong relative
hyperbolicity of the Weil-Petersson metric via consideration of its coarse
quasi-isometric model, the "pants graph." We show that in dimension~3 the pants
graph is strongly relatively hyperbolic with respect to naturally defined
product regions and show any quasi-flat lies a bounded distance from a single
product. For all higher dimensions there is no non-trivial collection of
subsets with respect to which it strongly relatively hyperbolic; this extends a
theorem of [BDM] in dimension 6 and higher into the intermediate range (it is
hyperbolic if and only if the dimension is 1 or 2 [BF]). Stability and relative
stability of quasi-geodesics in dimensions up through 3 provide for a strong
understanding of the behavior of geodesics and a complete description of the
CAT(0)-boundary of the Weil-Petersson metric via curve-hierarchies and their
associated "boundary laminations."


title: Secrecy Capacity Region of Fading Broadcast Channels

abstract:
  The fading broadcast channel with confidential messages (BCC) is
investigated, where a source node has common information for two receivers
(receivers 1 and 2), and has confidential information intended only for
receiver 1. The confidential information needs to be kept as secret as possible
from receiver 2. The channel state information (CSI) is assumed to be known at
both the transmitter and the receivers. The secrecy capacity region is first
established for the parallel Gaussian BCC, and the optimal source power
allocations that achieve the boundary of the secrecy capacity region are
derived. In particular, the secrecy capacity region is established for the
Gaussian case of the Csiszar-Korner BCC model. The secrecy capacity results are
then applied to give the ergodic secrecy capacity region for the fading BCC.


title: On strict inclusions in hierarchies of convex bodies

abstract:
  Let $\mathcal I_k$ be the class of convex $k$-intersection bodies in
$\mathbb{R}^n$ (in the sense of Koldobsky) and $\mathcal I_k^m$ be the class of
convex origin-symmetric bodies all of whose $m$-dimensional central sections
are $k$-intersection bodies. We show that 1) $\mathcal I_k^m\not\subset
\mathcal I_k^{m+1}$, $k+3\le m<n$, and 2) $\mathcal I_l \not\subset \mathcal
I_k$, $1\le k<l < n-3$.


title:
Extra Current and Integer Quantum Hall Conductance in the Spin-Orbit
  Coupling System

abstract:
  We study the extra term of particle current in a 2D k-cubic Rashba spin-orbit
coupling system and the integer quantization of the Hall conductance in this
system. We provide a correct formula of charge current in this system and the
careful consideration of extra currents provides a stronger theoretical basis
for the theory of the quantum Hall effect which has not been considered before.
The non-trivial extra contribution to the particle current density and local
conductivity, which originates from the cubic dependence on the momentum
operator in the Hamiltonian, will have no effect on the integer quantization of
the Hall conductance. The extension of Noether's theorem for the 2D k-cubic
Rashba system is also addressed. The two methods reach to exactly the same
results.


title: On l^p norms of weighted mean matrices

abstract:
  We study $l^{p}$ operator norms of weighted mean matrices using the
approaches of Kaluza-Szeg\"o and Redheffer. As an application, we prove a
conjecture of Bennett.


title: Integrable operators and squares of Hankel Matrices

abstract:
  In this note, we find sufficient conditions for an operator with kernel of
the form $A(x)B(y)-A(x)B(y)/(x-y)$ (which we call a Tracy-Widom type operator)
to be the square of a Hankel operator. We consider two contexts: infinite
matrices on $\ell^2$, and integral operators on the Hardy space
$H^2(\mathbb{T})$. The results can be applied to the discrete Bessel kernel,
which is significant in random matrix theory.


title: Dynamical laws of superenergy in General Relativity

abstract:
  The Bel and Bel-Robinson tensors were introduced nearly fifty years ago in an
attempt to generalize to gravitation the energy-momentum tensor of
electromagnetism. This generalization was successful from the mathematical
point of view because these tensors share mathematical properties which are
remarkably similar to those of the energy-momentum tensor of electromagnetism.
However, the physical role of these tensors in General Relativity has remained
obscure and no interpretation has achieved wide acceptance. In principle, they
cannot represent {\em energy} and the term {\em superenergy} has been coined
for the hypothetical physical magnitude lying behind them. In this work we try
to shed light on the true physical meaning of {\em superenergy} by following
the same procedure which enables us to give an interpretation of the
electromagnetic energy. This procedure consists in performing an orthogonal
splitting of the Bel and Bel-Robinson tensors and analysing the different parts
resulting from the splitting. In the electromagnetic case such splitting gives
rise to the electromagnetic {\em energy density}, the Poynting vector and the
electromagnetic stress tensor, each of them having a precise physical
interpretation which is deduced from the {\em dynamical laws} of
electromagnetism (Poynting theorem). The full orthogonal splitting of the Bel
and Bel-Robinson tensors is more complex but, as expected, similarities with
electromagnetism are present. Also the covariant divergence of the Bel tensor
is analogous to the covariant divergence of the electromagnetic energy-momentum
tensor and the orthogonal splitting of the former is found. The ensuing {\em
equations} are to the superenergy what the Poynting theorem is to
electromagnetism. See paper for full abstract.


title: Modified Shephard's problem on projections of convex bodies

abstract:
  We disprove a conjecture of A. Koldobsky asking whether it is enough to
compare $(n-2)$-derivatives of the projection functions of two symmetric convex
bodies in the Shephard problem in order to get a positive answer in all
dimensions.