title: BCOV ring and holomorphic anomaly equation

abstract:
  We study certain differential rings over the moduli space of Calabi-Yau
manifolds. In the case of an elliptic curve, we observe a close relation to the
differential ring of quasi-modular forms due to Kaneko and Zagier.


title: Kernel(s) for Problems With no Kernel: On Out-Trees With Many Leaves

abstract:
  The {\sc $k$-Leaf Out-Branching} problem is to find an out-branching (i.e. a
rooted oriented spanning tree) with at least $k$ leaves in a given digraph. The
problem has recently received much attention from the viewpoint of
parameterized algorithms {alonLNCS4596,AlonFGKS07fsttcs,BoDo2,KnLaRo}. In this
paper we step aside and take a kernelization based approach to the {\sc
$k$-Leaf-Out-Branching} problem. We give the first polynomial kernel for {\sc
Rooted $k$-Leaf-Out-Branching}, a variant of {\sc $k$-Leaf-Out-Branching} where
the root of the tree searched for is also a part of the input. Our kernel has
cubic size and is obtained using extremal combinatorics.
  For the {\sc $k$-Leaf-Out-Branching} problem we show that no polynomial
kernel is possible unless polynomial hierarchy collapses to third level
%$PH=\Sigma_p^3$ by applying a recent breakthrough result by Bodlaender et al.
{BDFH08} in a non-trivial fashion. However our positive results for {\sc Rooted
$k$-Leaf-Out-Branching} immediately imply that the seemingly intractable the
{\sc $k$-Leaf-Out-Branching} problem admits a data reduction to $n$ independent
$O(k^3)$ kernels. These two results, tractability and intractability side by
side, are the first separating {\it many-to-one kernelization} from {\it Turing
kernelization}. This answers affirmatively an open problem regarding "cheat
kernelization" raised in {IWPECOPEN08}.


title: Supersymmetry, General Relativity and Unity of Nature

abstract:
  The basic idea and some physical implications of nonlinear supersymmetric
general relativity (NLSUSY GR) are presented. NLSUSY GR may give new insights
into the origin of mass and the mysterious relations between the cosmology and
the low energy particle physics, e.g. the spontaneous SUSY breaking scale, the
cosmological constant, the (dark) energy density of the universe and the
neutrino mass.

categories: hep-th astro-ph gr-qc hep-ph math-ph math.MP


title:
Analysis of Firing Behaviors in Networks of Pulse-Coupled Oscillators
  with Delayed Excitatory Coupling

abstract:
  For networks of pulse-coupled oscillators with delayed excitatory coupling,
we analyze the firing behaviors depending on coupling strength and transmission
delay. The parameter space consisting of strength and delay is partitioned into
two regions. For one region, we derive a low bound of interspike intervals,
from which three firing properties are obtained. However, this bound and these
properties would no longer hold for another region. Finally, we show the
different synchronization behaviors for networks with parameters in the two
regions.


title: Next-to-leading order static gluon self-energy for anisotropic plasmas

abstract:
  In this paper the structure of the next-to-leading (NLO) static gluon self
energy for an anisotropic plasma is investigated in the limit of a small
momentum space anisotropy. Using the Ward identities for the static hard-loop
(HL) gluon polarization tensor and the (nontrivial) static HL vertices, we
derive a comparatively compact form for the complete NLO correction to the
structure function containing the space-like pole associated with magnetic
instabilities. On the basis of a calculation without HL vertices, it has been
conjectured that the imaginary part of this structure function is nonzero,
rendering the space-like poles integrable. We show that there are both positive
and negative contributions when HL vertices are included, highlighting the
necessity of a complete numerical evaluation, for which the present work
provides the basis.


title:
On the Pierce-Birkhoff Conjecture for Smooth Affine Surfaces over Real
  Closed Fields

abstract:
  We will prove that the Pierce-Birkhoff Conjecture holds for non-singular
two-dimensional affine real algebraic varieties over real closed fields, i.e.,
if W is such a variety, then every piecewise polynomial function on W can be
written as suprema of infima of polynomial functions on W. More precisely, we
will give a proof of the so-called Connectedness Conjecture for the coordinate
rings of such varieties, which implies the Pierce-Birkhoff Conjecture.


title:
Hard X-ray/soft gamma-ray Characteristics of the Persistent Emission
  from Magnetars

abstract:
  In this paper the current status of high-energy research on the hard X-ray
characteristics of the persistent emission from magnetars is reviewed. Focus is
put on recent intriguing results for 1RXS J1708-40, from phase resolved
spectral analysis over a 2 decades wide energy band (~3-300 keV) combining
contemporaneous RXTE, XMM and INTEGRAL data. For 1E 1841-045 and SGR 1806-10 we
also present updated results. The perspective for future MAXI observations for
this source class is also addressed.


title: Robust nonparametric estimation via wavelet median regression

abstract:
  In this paper we develop a nonparametric regression method that is
simultaneously adaptive over a wide range of function classes for the
regression function and robust over a large collection of error distributions,
including those that are heavy-tailed, and may not even possess variances or
means. Our approach is to first use local medians to turn the problem of
nonparametric regression with unknown noise distribution into a standard
Gaussian regression problem and then apply a wavelet block thresholding
procedure to construct an estimator of the regression function. It is shown
that the estimator simultaneously attains the optimal rate of convergence over
a wide range of the Besov classes, without prior knowledge of the smoothness of
the underlying functions or prior knowledge of the error distribution. The
estimator also automatically adapts to the local smoothness of the underlying
function, and attains the local adaptive minimax rate for estimating functions
at a point. A key technical result in our development is a quantile coupling
theorem which gives a tight bound for the quantile coupling between the sample
medians and a normal variable. This median coupling inequality may be of
independent interest.


title:
Forbush decreases and solar events seen in the 10 - 20GeV energy range
  by the Karlsruhe Muon Telescope

abstract:
  Since 1993, a muon telescope located at Forschungszentrum Karlsruhe
(Karlsruhe Muon Telescope) has been recording the flux of single muons mostly
originating from primary cosmic-ray protons with dominant energies in the 10 -
20 GeV range. The data are used to investigate the influence of solar effects
on the flux of cosmic-rays measured at Earth. Non-periodic events like Forbush
decreases and ground level enhancements are detected in the registered muon
flux. A selection of recent events will be presented and compared to data from
the Jungfraujoch neutron monitor. The data of the Karlsruhe Muon Telescope help
to extend the knowledge about Forbush decreases and ground level enhancements
to energies beyond the neutron monitor regime.


title:
XMM-Newton observations of IGR J00291+5934: signs of a thermal spectral
  component during quiescence

abstract:
  We present X-ray observations of the transient accretion-powered millisecond
pulsar IGR J00291+5934 during quiescence. IGR J00291+5934 is the first source
among accretion powered millisecond pulsars to show signs of a thermal
component in its quiescent spectrum. Fitting this component with a neutron star
atmosphere or a black body model we obtain soft temperatures (~64 eV and ~110
eV, respectively). As in other sources of this class a hard spectral component
is also present, comprising more than 60% of the unabsorbed 0.5-10 keV flux.
Interpreting the soft component as cooling emission from the neutron star, we
can conclude that the compact object can be spun up to milliscond periods by
accreting only <0.2 solar masses.


title: The Toledo invariant on smooth varieties of general type

abstract:
  We propose a definition of the Toledo invariant for representations of
fundamental groups of smooth varieties of general type into semisimple Lie
groups of Hermitian type. This definition allows to generalize the results
known in the classical case of representations of complex hyperbolic lattices
to this new setting: assuming that the rank of the target Lie group is not
greater than two, we prove that the Toledo invariant satisfies a Milnor-Wood
type inequality and we characterize the corresponding maximal representations.


title: On the number of inscribed squares of a simple closed curve in the plane

abstract:
  We show that for every positive integer n there is a simple closed curve in
the plane (which can be taken infinitely differentiable and convex) which has
exactly n inscribed squares.


title: A SURE Approach for Digital Signal/Image Deconvolution Problems

abstract:
  In this paper, we are interested in the classical problem of restoring data
degraded by a convolution and the addition of a white Gaussian noise. The
originality of the proposed approach is two-fold. Firstly, we formulate the
restoration problem as a nonlinear estimation problem leading to the
minimization of a criterion derived from Stein's unbiased quadratic risk
estimate. Secondly, the deconvolution procedure is performed using any analysis
and synthesis frames that can be overcomplete or not. New theoretical results
concerning the calculation of the variance of the Stein's risk estimate are
also provided in this work. Simulations carried out on natural images show the
good performance of our method w.r.t. conventional wavelet-based restoration
methods.


title:
Analysis of variance, coefficient of determination and $F$-test for
  local polynomial regression

abstract:
  This paper provides ANOVA inference for nonparametric local polynomial
regression (LPR) in analogy with ANOVA tools for the classical linear
regression model. A surprisingly simple and exact local ANOVA decomposition is
established, and a local R-squared quantity is defined to measure the
proportion of local variation explained by fitting LPR. A global ANOVA
decomposition is obtained by integrating local counterparts, and a global
R-squared and a symmetric projection matrix are defined. We show that the
proposed projection matrix is asymptotically idempotent and asymptotically
orthogonal to its complement, naturally leading to an $F$-test for testing for
no effect. A by-product result is that the asymptotic bias of the ``projected''
response based on local linear regression is of quartic order of the bandwidth.
Numerical results illustrate the behaviors of the proposed R-squared and
$F$-test. The ANOVA methodology is also extended to varying coefficient models.


title: XQuery Join Graph Isolation

abstract:
  A purely relational account of the true XQuery semantics can turn any
relational database system into an XQuery processor. Compiling nested
expressions of the fully compositional XQuery language, however, yields odd
algebraic plan shapes featuring scattered distributions of join operators that
currently overwhelm commercial SQL query optimizers.
  This work rewrites such plans before submission to the relational database
back-end. Once cast into the shape of join graphs, we have found off-the-shelf
relational query optimizers--the B-tree indexing subsystem and join tree
planner, in particular--to cope and even be autonomously capable of
"reinventing" advanced processing strategies that have originally been devised
specifically for the XQuery domain, e.g., XPath step reordering, axis reversal,
and path stitching. Performance assessments provide evidence that relational
query engines are among the most versatile and efficient XQuery processors
readily available today.


title: Nodeless spin triplet superconducting gap in Sr2RuO4

abstract:
  We report on tunneling spectroscopy measurements using a Scanning Tunneling
Microscope (STM) on the spin triplet superconductor Sr2RuO4. We find a
negligible density of states close to the Fermi level and a fully opened gap
with a value of $\Delta$=0.28 meV, which disappears at T$_c$ = 1.5 K. $\Delta$
is close to the result expected from weak coupling BCS theory
($\Delta_0$=1.76kBT$_c$ = 0.229 meV). Odd parity superconductivity is
associated with a fully isotropic gap without nodes over a significant part of
the Fermi surface.


title:
Particle production in models with helicity-0 graviton ghost in de
  Sitter spacetime

abstract:
  We revisit the problem of the helicity-0 ghost mode of massive graviton in
the de Sitter background. In general, the presence of a ghost particle, which
has negative energy, drives the vacuum to be unstable through pair production
of ghost particles and ordinary particles. In the case that the vacuum state
preserves the de Sitter invariance, the number density created by the pair
production inevitably diverges due to unsuppressed ultra-violet(UV)
contributions. In such cases one can immediately conclude that the model is not
viable. However, in the massive gravity theory we cannot construct a vacuum
state which respects the de Sitter invariance. Therefore the presence of a
ghost does not immediately mean the breakdown of the model. Explicitly
estimating the number density and the energy density of particles created by
the pair production of two conformal scalar particles and one helicity-0 ghost
graviton, we find that these densities both diverge. However, since models with
helicity-0 ghost graviton have no de Sitter invariant vacuum state, it is
rather natural to consider a UV cutoff scale in the three-dimensional momentum
space. Then, even if we take the cutoff scale as large as the Planck scale, the
created number density and energy density are well suppressed. In many models
the cutoff scale is smaller than the Planck scale. In such models the created
number density and the energy density are negligiblly small as long as only the
physics below the cutoff scale is concerned.


title: A constructive proof of the Lovasz Local Lemma

abstract:
  The Lovasz Local Lemma [EL75] is a powerful tool to prove the existence of
combinatorial objects meeting a prescribed collection of criteria. The
technique can directly be applied to the satisfiability problem, yielding that
a k-CNF formula in which each clause has common variables with at most 2^(k-2)
other clauses is always satisfiable. All hitherto known proofs of the Local
Lemma are non-constructive and do thus not provide a recipe as to how a
satisfying assignment to such a formula can be efficiently found. In his
breakthrough paper [Bec91], Beck demonstrated that if the neighbourhood of each
clause be restricted to O(2^(k/48)), a polynomial time algorithm for the search
problem exists. Alon simplified and randomized his procedure and improved the
bound to O(2^(k/8)) [Alo91]. Srinivasan presented in [Sri08] a variant that
achieves a bound of essentially O(2^(k/4)). In [Mos08], we improved this to
O(2^(k/2)). In the present paper, we give a randomized algorithm that finds a
satisfying assignment to every k-CNF formula in which each clause has a
neighbourhood of at most the asymptotic optimum of 2^(k-5)-1 other clauses and
that runs in expected time polynomial in the size of the formula, irrespective
of k. If k is considered a constant, we can also give a deterministic variant.
In contrast to all previous approaches, our analysis does not anymore invoke
the standard non-constructive versions of the Local Lemma and can therefore be
considered an alternative, constructive proof of it.


title: Measures on Mixing Angles

abstract:
  We address the problem of the apparently very small magnitude of CP violation
in the standard model, measured by the Jarlskog invariant J. In order to make
statements about probabilities for certain values of J, we seek to find a
natural measure on the space of Kobayashi-Maskawa matrices, the double quotient
U(1)^2\SU(3)/U(1)^2. We review several possible, geometrically motivated
choices of the measure, and compute expectation values for powers of J for
these measures. We find that different choices of the measure generically make
the observed magnitude of CP violation appear finely tuned. Since the quark
masses and the mixing angles are determined by the same set of Yukawa
couplings, we then do a second calculation in which we take the known quark
mass hierarchy into account. We construct the simplest measure on the space of
3 x 3 Hermitian matrices which reproduces this known hierarchy. Calculating
expectation values for powers of J in this second approach, we find that values
of J close to the observed value are now rather likely, and there does not seem
to be any fine tuning. Our results suggest that the choice of Kobayashi-Maskawa
angles is closely linked to the observed mass hierarchy. We close by discussing
the corresponding case of neutrinos.


title: Anomaly-free singularities in the generalized Kohn variational method

abstract:
  We have carried out an analysis of singularities in Kohn variational
calculations for low energy e^{+}-H_{2} elastic scattering. Provided that a
sufficiently accurate trial wavefunction is used, we argue that our
implementation of the Kohn variational principle necessarily gives rise to
singularities which are not spurious. We propose two approaches for optimizing
a free parameter of the trial wavefunction in order to avoid anomalous
behaviour in scattering phase shift calculations, the first of which is based
on the existence of such singularities. The second approach is a more
conventional optimization of the generalized Kohn method. Close agreement is
observed between the results of the two optimization schemes; further, they
give results which are seen to be effectively equivalent to those obtained with
the complex Kohn method. The advantage of the first optimization scheme is that
it does not require an explicit solution of the Kohn equations to be found. We
give examples of anomalies which cannot be avoided using either optimization
scheme but show that it is possible to avoid these anomalies by considering
variations in the nonlinear parameters of the trial function.


title:
Examples of derivation-based differential calculi related to
  noncommutative gauge theories

abstract:
  Some derivation-based differential calculi which have been used to construct
models of noncommutative gauge theories are presented and commented. Some
comparisons between them are made.


title:
A Path Integration Approach to the Correlators of XY Heisenberg Magnet
  and Random Walks

abstract:
  The path integral approach is used for the calculation of the correlation
functions of the $XY$ Heisenberg chain. The obtained answers for the two-point
correlators of the $XX$ magnet are of the determinantal form and are
interpreted in terms of the generating functions for the random turns vicious
walkers.


title: New Physics Effects in $B$ Decays

abstract:
  The two $B$-factories, Belle and BaBar, has been played major roles in the B
decays study. Their wonderful design and excellent operation enables their
fruitful analysis results. Also recently the Tevatron experiments, CDF and DO,
join the game with their $B_S$ studies. From the experimental results of $B$
decay studies, we learn that most of measurements are consistent with the
Standard Model (SM). Some discrepancies from the SM has been found in the
measurements of the phases and magnitudes of CKM unitary triangle. There are
also various theoretical models that possibly give the contributions. These
will relay on further validation with new experimental results.


title:
Reversible phase transformation and doubly-charged anions at the surface
  of simple cubic RbC60

abstract:
  The simple cubic phase of a RbC60 thin film has been studied using
photoelectron spectroscopy. The simple cubic-to-dimer transition is found to be
reversible at the film surface. A sharp Fermi edge is observed and a lower
limit of 0.5 eV is found for the surface Hubbard U, pointing to a
strongly-correlated metallic character of thin-film simple cubic RbC60. A
molecular charge state is identified in the valence band and core level
photoemission spectra which arises from C602- anions and contributes to the
spectral intensity at the Fermi level.


title: Minimum-Bias and Underlying Event Studies at CMS

abstract:
  The "Underlying Event" at CMS (under nominal and start-up conditions) is
studied by examining charged particle and momentum densities in the
"transverse" region in charged particle jet production. The predictions of
various QCD models with different multiple parton interaction schemes correctly
reproduce Tevatron data, however they fail to agree with each other when
extrapolated to the LHC energy. The possibility of discriminating among these
models is presented. Exploring QCD dynamics in proton-proton collisions at
center-of-mass energy of 14 TeV, and the importance of improving and tuning the
QCD Monte Carlo models at start-up are also analyzed.


title: Densities, Laplace Transforms and Analytic Number Theory

abstract:
  Li showed that the Riemann Hypothesis is equivalent to the nonnegativity of a
certain sequence of numbers. Bombieri and Lagarias gave an arithmetic formula
for the number sequence based on the Guinand-Weil explicit formula and showed
that Li's criterion is equivalent to Weil's criterion for the Riemann
Hypothesis. We provide a derivation of the explicit formula based on Laplace
transforms and present an alternative expression for Li's criterion that
invites a probabilistic interpretation.


title:
Estimation of distributions, moments and quantiles in deconvolution
  problems

abstract:
  When using the bootstrap in the presence of measurement error, we must first
estimate the target distribution function; we cannot directly resample, since
we do not have a sample from the target. These and other considerations
motivate the development of estimators of distributions, and of related
quantities such as moments and quantiles, in errors-in-variables settings. We
show that such estimators have curious and unexpected properties. For example,
if the distributions of the variable of interest, $W$, say, and of the
observation error are both centered at zero, then the rate of convergence of an
estimator of the distribution function of $W$ can be slower at the origin than
away from the origin. This is an intrinsic characteristic of the problem, not a
quirk of particular estimators; the property holds true for optimal estimators.


title: Coherent spin radiation by magnetic nanomolecules and nanoclusters

abstract:
  The peculiarities of coherent spin radiation by magnetic nanomolecules is
investigated by means of numerical simulation. The consideration is based on a
microscopic Hamiltonian taking into account realistic dipole interactions.
Superradiance can be realized only when the molecular sample is coupled to a
resonant electric circuit. The feedback mechanism allows for the achievement of
a fast spin reversal time and large radiation intensity. The influence on the
level of radiation, caused by sample shape and orientation, is analysed. The
most powerful coherent radiation is found to occur for an elongated sample
directed along the resonator magnetic field.


title: The fainter the better: cataclysmic variable stars from the SDSS

abstract:
  The Sloan Digital Sky Survey has identified a total of 212 cataclysmic
variables, most of which are fainter than 18th magnitude. This is the deepest
and most populous homogeneous sample of cataclysmic variables to date, and we
are undertaking a project to characterise this population. We have found that
the SDSS sample is dominated by a great ``silent majority'' of old and faint
CVs. We detect, for the first time, a population spike at the minimum period of
80 minutes which has been predicted by theoretical studies for over a decade.


title:
High order resolution of the Maxwell-Fokker-Planck-Landau model intended
  for ICF applications

abstract:
  A high order, deterministic direct numerical method is proposed for the
nonrelativistic $2D_{\bf x} \times 3D_{\bf v}$ Vlasov-Maxwell system, coupled
with Fokker-Planck-Landau type operators. Such a system is devoted to the
modelling of electronic transport and energy deposition in the general frame of
Inertial Confinement Fusion applications. It describes the kinetics of plasma
physics in the nonlocal thermodynamic equilibrium regime. Strong numerical
constraints lead us to develop specific methods and approaches for validation,
that might be used in other fields where couplings between equations,
multiscale physics, and high dimensionality are involved. Parallelisation (MPI
communication standard) and fast algorithms such as the multigrid method are
employed, that make this direct approach be computationally affordable for
simulations of hundreds of picoseconds, when dealing with configurations that
present five dimensions in phase space.


title:
Comment on "Bell Experiment with Genuine Energy-Time Entanglement" by
  Cabello et al.: Why Franson's Experiment Violates Local Realism

abstract:
  It is shown that the model introduced by Cabello et al. to criticize the
Franson experiment suffers from the same weakness as the previous model
introduced by Aerts et al. with the same purpose. It is also shown why we can
assume with confidence that the Franson experiment does violate local realism.


title: Derived Representation Theory and the Algebraic K-theory of Fields

abstract:
  We describe the construction which takes as input a profinite group, which
when applied the the absolute Galois group of a geometric field F agrees in
some cases with the algebraic K-theory of F. We prove that it agrees in the
case of a topologically finitely generated abelian absolute Galois group, and
conjecture that it agrees for all geometric fields. We also discuss properties
of the construction, including relationships with the representation theory of
infinite discrete groups.


title:
Embedding approach for dynamical mean field theory of strongly
  correlated heterostructures

abstract:
  We present an embedding approach based on localized basis functions which
permits an efficient application of the dynamical mean field theory (DMFT) to
inhomogeneous correlated materials, such as semi-infinite surfaces and
heterostructures. In this scheme, the semi-infinite substrate leads connected
to both sides of the central region of interest are represented via complex,
energy-dependent embedding potentials that incorporate one-electron as well as
many-body effects within the substrates. As a result, the number of layers
which must be treated explicitly in the layer-coupled DMFT equation is greatly
reduced. To illustrate the usefulness of this approach, we present numerical
results for strongly correlated surfaces, interfaces, and heterostructures of
the single-band Hubbard model.


title:
Modeling He-rich subdwarfs through the hot-flasher scenario (brief
  version)

abstract:
  We present 1D numerical simulations aimed at studying the hot-flasher
scenario for the formation of He-rich subdwarf stars. Sequences were calculated
for a wide range of metallicities and with the He core flash at different
points of the post-RGB evolution (i.e. different remnant masses). We followed
the complete evolution from the ZAMS, through the hot-flasher event, and to the
subdwarf stage for all kinds of hot-flashers. This allows us to present a
homogeneous set of abundances for different metallicities and all flavors of
hot-flashers. We extend the scope of our work by analyzing the effects in the
predicted surface abundances of some standard assumptions in convective mixing
and the effects of element diffusion.
  We find that the hot-flasher scenario is a viable explanation for the
formation of He-sdO stars. Our results also show that element diffusion may
produce the transformation of (post hot-flasher) He-rich atmospheres into
He-deficient ones. If this is so, then the hot-flasher scenario is able to
reproduce both the observed properties and distribution of He-sdO stars.


title:
High energy factorization in nucleus-nucleus collisions III. Long range
  rapidity correlations

abstract:
  We obtain a novel result in QCD for long range rapidity correlations between
gluons produced in the collision of saturated high energy hadrons or nuclei.
This result, obtained in a high energy factorization framework, provides strong
justification for the Glasma flux tube picture of coherent strong color fields.
Our formalism can be applied to "near side ridge" events at RHIC and in future
studies of long range rapidity correlations at the LHC.


title: A survey of Einstein metrics on 4-manifolds

abstract:
  We survey some aspects of the current state of research on Einstein metrics
on compact 4-manifolds. A number of open problems are presented and discussed.


title: Determination of Wtb anomalous coupling at the ILC

abstract:
  We present a study of experimental determination of the Wtb anomalous
couplings in the $t\bar{t}$ process at the International Linear Collider in the
framework of effective field theory. The theory predicts several observables
that are particularly sensitive to the couplings including the asymmetry of the
bottom quark angular distributions. These observables require excellent
identification capabilities for the b quark in a detector. We describe tools
needed for the identification with particular emphasis on determination of the
quark charge and b-tagging together with generic selections for the $t\bar{t}$
events. The focus of the study is on the all hadronic decay channel which
provides the largest statistics. In the study we demonstrate advantages of the
clean environment of the ILC that allow a precise measurement of the
observables. We also explain how this process can be used for optimisation of
ILC detector in the context of the SiD detector concept


title:
Stellar abundances and ages for metal-rich Milky Way globular clusters -
  Stellar parameters and elemental abundances for 9 HB stars in NGC6352

abstract:
  [ABRIDGED] Metal-rich globular clusters provide important tracers of the
formation of our Galaxy. Moreover, and not less important, they are very
important calibrators for the derivation of properties of extra-galactic
metal-rich stellar populations. Nonetheless, only a few of the metal-rich
globular clusters in the Milky Way have been studied using high-resolution
stellar spectra to derive elemental abundances. In this paper we present
elemental abundances for nine HB stars in the metal-rich globular cluster
NGC6352. The elemental abundances are based on high-resolution, high
signal-to-noise spectra obtained with VLT/UVES. The elemental abundances have
been derived using standard LTE calculations. We find that NGC6352 has [Fe/H]=
-0.55, is enhanced in the alpha-elements to about +0.2 dex for Ca, Si, and Ti
relative to Fe. For the iron-peak elements we find solar values. Based on the
spectroscopically derived stellar parameters we find that an E(B-V)=0.24 and
(m-M) roughly equal to 14.05 better fits the data than the nominal values. An
investigation of log(gf)-values for suitable FeI lines lead us to the
conclusion that the commonly used correction to the May et al.(1974) data
should not be employed. Note: only the postscript reproduces the finding chart
correctly.


title:
Complex Valued Analytic Torsion for Flat Bundles and for Holomorphic
  Bundles with (1,1) Connections

abstract:
  The work of Ray and Singer which introduced analytic torsion, a kind of
determinant of the Laplacian operator in topological and holomorphic settings,
is naturally generalized in both settings. The couplings are extended in a
direct way in the topological setting to general flat bundles and in the
holomorphic setting to bundles with (1,1) connections, which using the
Newlander-Nirenberg Theorem are seen to be the bundles with both holomorphic
and anti-holomorphic structures. The resulting natural generalizations of
Laplacians are not always self-adjoint and the corresponding generalizations of
analytic torsions are thus not always real-valued. The Cheeger-Muller theorem,
on equivalence in a topological setting of analytic torsion to classical
topological torsion, generalizes to this complex-valued torsion. On the
algebraic side the methods introduced include a notion of torsion associated to
a complex equipped with both boundary and coboundry maps.


title:
Nondispersive radial solutions to energy supercritical non-linear wave
  equations, with applications

abstract:
  In this paper we establish optimal pointwise decay estimates for
non-dispersive (compact) radial solutions to non-linear wave equations in 3
dimensions, in the energy supercritical range. As an application, we show for
the full energy supercritical range, in the defocusing case, that if the scale
invariant Sobolev norm of a radial solution remains bounded in its maximal
interval of existence, then the solution must exist for all times and scatter.


title: Nanoparticle networks as chemoselective sensing devices

abstract:
  We theoretically analyzed transport properties of a molecular network
constructed of gold nanoparticles linked with oligophenylenevinulene (OPV)
molecules. We showed that the conductance of such system was strongly reduced
when trinitrotoluene (TNT) became attached to the OPV linkers in the network.
The reported results are based on the ab inicio electronic structure
calculations. These results corroborate and elucidate experiments which
revealed significant drops in the conductance the network while the latter was
exposed to TNT vapors. The results suggest that the detected sensitivity of
transport characteristics of the considered nanoparticle network to TNT may be
used to design a sensing nanodevice.


title: Simplicial complexes and minimal free resolution of monomial algebras

abstract:
  This paper is concerned with the combinatorial description of the graded
minimal free resolution of certain monomial algebras which includes toric
rings. Concretely, we explicitly describe how the graded minimal free
resolution of those algebras is related to the combinatorics of some simplicial
complexes. Our description may be interpreted as an algorithmic procedure to
partially compute this resolution.


title:
Multisite versus multiorbital Coulomb correlations studied within
  finite-temperature exact diagonalization dynamical mean-field theory

abstract:
  The influence of short-range Coulomb correlations on the Mott transition in
the single-band Hubbard model at half-filling is studied within cellular
dynamical mean field theory for square and triangular lattices.
Finite-temperature exact diagonalization is used to investigate correlations
within two-, three-, and four-site clusters. Transforming the non-local
self-energy from a site basis to a molecular orbital basis, we focus on the
inter-orbital charge transfer between these cluster molecular orbitals in the
vicinity of the Mott transition. In all cases studied, the charge transfer is
found to be small, indicating weak Coulomb induced orbital polarization despite
sizable level splitting between orbitals. These results demonstrate that all
cluster molecular orbitals take part in the Mott transition and that the
insulating gap opens simultaneously across the entire Fermi surface. Thus, at
half-filling we do not find orbital-selective Mott transitions, nor a
combination of band filling and Mott transition in different orbitals.
Nevertheless, the approach towards the transition differs greatly between
cluster orbitals, giving rise to a pronounced momentum variation along the
Fermi surface, in agreement with previous works. The near absence of Coulomb
induced orbital polarization in these clusters differs qualitatively from
single-site multi-orbital studies of several transition metal oxides, where the
Mott phase exhibits nearly complete orbital polarization as a result of a
correlation driven enhancement of the crystal field splitting. The strong
single-particle coupling among cluster orbitals in the single-band case is
identified as the source of this difference.


title:
On the contribution of large scale structure to strong gravitational
  lensing

abstract:
  We study the correlation between the locations of galaxy-galaxy strong
lensing candidates and tracers of large-scale structure from both weak lensing
or X-ray emission. The COSMOS survey is a unique data set, combining deep, high
resolution and contiguous imaging in which strong lenses have been discovered,
plus unparalleled multiwavelength coverage. To help interpret the COSMOS data,
we have also produced mock COSMOS strong and weak lensing observations, based
on ray-tracing through the Millenium simulation. In agreement with the
simulations, we find that strongly lensed images with the largest angular
separations are found in the densest regions of the COSMOS field. This is
explained by a prevalence among the lens population in dense environments of
elliptical galaxies with high total-to-stellar mass ratios, which can deflect
light through larger angles. However, we also find that the overall fraction of
elliptical galaxies with strong gravitational lensing is independent of the
local mass density; this observation is not true of the simulations, which
predict an increasing fraction of strong lenses in dense environments. The
discrepancy may be a real effect, but could also be explained by various
limitations of our analysis. For example, our visual search of strong lens
systems could be incomplete and suffer from selection bias; the luminosity
function of elliptical galaxies may differ between our real and simulated data;
or the simplifying assumptions and approximations used in our lensing
simulations may be inadequate. Work is therefore ongoing. Automated searches
for strong lens systems will be particularly important in better constraining
the selection function.


title: Oscillations and patterns in interacting populations of two species

abstract:
  Interacting populations often create complicated spatiotemporal behavior, and
understanding it is a basic problem in the dynamics of spatial systems. We
study the two-species case by simulations of a host--parasitoid model. In the
case of co-existence, there are spatial patterns leading to noise-sustained
oscillations. We introduce a new measure for the patterns, and explain the
oscillations as a consequence of a timescale separation and noise. They are
linked together with the patterns by letting the spreading rates depend on
instantaneous population densities. Applications are discussed.


title:
The Pursuit of Uniqueness: Extending Valiant-Vazirani Theorem to the
  Probabilistic and Quantum Settings

abstract:
  Valiant-Vazirani showed in 1985 [VV85] that solving NP with the promise that
"yes" instances have only one witness is powerful enough to solve the entire NP
class (under randomized reductions).
  We are interested in extending this result to the quantum setting. We prove
extensions to the classes Merlin-Arthur MA and Quantum-Classical-Merlin-Arthur
QCMA. Our results have implications for the complexity of approximating the
ground state energy of a quantum local Hamiltonian with a unique ground state
and an inverse polynomial spectral gap. We show that the estimation (to within
polynomial accuracy) of the ground state energy of poly-gapped 1-D local
Hamiltonians is QCMA-hard [AN02], under randomized reductions. This is in stark
contrast to the case of constant gapped 1-D Hamiltonians, which is in NP
[Has07]. Moreover, it shows that unless QCMA can be reduced to NP by randomized
reductions, there is no classical description of the ground state of every
poly-gapped local Hamiltonian that allows efficient calculation of expectation
values.
  Finally, we discuss a few of the obstacles to the establishment of an
analogous result to the class Quantum-Merlin-Arthur (QMA). In particular, we
show that random projections fail to provide a polynomial gap between two
witnesses.


title:
Possible scaling behaviour of the multiplicities ratio in
  leptoproduction of charged pions in nuclear medium

abstract:
  In this paper it is demonstrated that based on two-dimensional distributions
in semi-inclusive deep inelastic scattering (SIDIS) data, obtained recently by
the HERMES experiment at DESY on different nuclei, which contains data for
charged pions produced in $z$ slices as a function of $\nu$, and in a $\nu$
slices as a function of $z$, it it is possible to parametrise a ratio of
multiplicities on nucleus and deuterium (per nucleon) $R_M^{h}$ in a form of a
function of a single variable $\tau$, which has the physical meaning of the
formation time of hadron. We call this effect $\tau$ scaling. $\tau$ is a
function of two variables $\nu$ and $z$. It is also shown that $R_M^{h}$ can be
presented in a form of a linear polynomial of $\tau$, $a_{11}$ + $\tau a_{12}$,
where parameters $a_{11}$ and $a_{12}$ do not depend on $\nu$ and $z$.


title: Concavity properties for free boundary elliptic problems

abstract:
  We prove some concavity properties connected to nonlinear Bernoulli type free
boundary problems. In particular, we prove a Brunn-Minkowski inequality and an
Urysohn's type inequality for the Bernoulli Constant and we study the behaviour
of the free boundary with respect to the given boundary data. Moreover we prove
a uniqueness result regarding the interior non-linear Bernoulli problem.


title:
Phase sensitive electron-phonon coupling in a superconducting proximity
  structure

abstract:
  We study the role of the superconducting proximity effect on the
electron-phonon energy exchange in diffusive normal metals (N) attached to
superconductors (S). The proximity effect modifies the spectral response of the
normal metal, in particular the local density of states. This leads to a
weakening of the electron-phonon energy relaxation. We show that the effect is
easily observable with modern thermometry methods, and predict that it can be
tuned in structures connected to multiple superconductors by adjusting the
phase difference between superconducting order parameters at the two NS
interfaces.


title: Predator-Prey Model for Stock Market Fluctuations

abstract:
  We present a dynamical model for the price evolution of financial assets. The
model is based in a two level structure. In the first stage one finds an
agent-based model that describes the present state of the investors' beliefs,
perspectives or strategies. The dynamics is inspired by a model for describing
predator-prey population evolution: agents change their mind through self- or
mutual interaction, and the decision is adopted on a random basis, with no
direct influence of the price itself. One of the most appealing properties of
such a system is the presence of large oscillations in the number of agents
sharing the same perspective, what may be linked with the existence of bullish
and bearish periods in financial markets. In the second stage one has the
pricing mechanism, which will be driven by the relative population in the
different investors' groups. The price equation will depend on the specific
nature of the species, and thus it may change from one market to the other: we
will firstly present a simple model of excess demand, and subsequently consider
a more elaborate liquidity model. The outcomes of both models are analysed and
compared.


title:
Relaxation of antiferromagnetic order in spin-1/2 chains following a
  quantum quench

abstract:
  We study the unitary time evolution of antiferromagnetic order in anisotropic
Heisenberg chains that are initially prepared in a pure quantum state far from
equilibrium. Our analysis indicates that the antiferromagnetic order imprinted
in the initial state vanishes exponentially. Depending on the anisotropy
parameter, oscillatory or non-oscillatory relaxation dynamics is observed.
Furthermore, the corresponding relaxation time exhibits a at the critical
point, in contrast to the usual notion of critical slowing down, from which a
maximum is expected.


title:
Possible causes of a rise with energy of the cosmic ray positron
  fraction

abstract:
  Based on general considerations rather than model-dependent fits to specific
scenarios, we argue that an increase with energy of the positron fraction in
cosmic rays, suggested by several experiments at E>~7 GeV, most likely requires
a primary source of electron-positron pairs. We discuss the possible
alternatives, and find none of them plausible on astrophysical or particle
physics grounds. Further observational ways to test different scenarios are
discussed.


title: Codimension one foliations with Bott-Morse singularities II

abstract:
  We study codimension one foliations with singularities defined locally by
Bott-Morse functions on closed oriented manifolds.
  We carry to this setting the classical concepts of holonomy of invariant sets
and stability, and prove a stability theorem in the spirit of the local
stability theorem of Reeb. This yields, among other things, a good topological
understanding of the leaves one may have around a center-type component of the
singular set, and also of the topology of its basin. The stability theorem
further allows the description of the topology of the boundary of the basin and
how the topology of the leaves changes when passing from inside to outside the
basin. This is described via fiberwise Milnor-Wallace surgery. A key-point for
this is to show that if the boundary of the basin of a center is non-empty,
then it contains a saddle; in this case we say that the center and the saddle
are paired. We then describe the possible pairings one may have in dimension
three and use a construction motivated by the classical saddle-node
bifurcation, that we call foliated surgery, that allows the reduction of
certain pairings of singularities of a foliation. This is used together with
our previous work on the topic to prove an extension for 3-manifolds of Reeb's
sphere recognition theorem.


title:
Determination of the neutron star mass-radii relation using narrow-band
  gravitational wave detector

abstract:
  The direct detection of gravitational waves will provide valuable
astrophysical information about many celestial objects. The most promising
sources of gravitational waves are neutron stars and black holes. These objects
emit waves in a very wide spectrum of frequencies determined by their
quasi-normal modes oscillations. In this work we are concerned with the
information we can extract from f and p$_I$-modes when a candidate leaves its
signature in the resonant mass detectors ALLEGRO, EXPLORER, NAUTILUS, MiniGrail
and SCHENBERG. Using the empirical equations, that relate the gravitational
wave frequency and damping time with the mass and radii of the source, we have
calculated the radii of the stars for a given interval of masses $M$ in the
range of frequencies that include the bandwidth of all resonant mass detectors.
With these values we obtain diagrams of mass-radii for different frequencies
that allowed to determine the better candidates to future detection taking in
account the compactness of the source. Finally, to determine which are the
models of compact stars that emit gravitational waves in the frequency band of
the mass resonant detectors, we compare the mass-radii diagrams obtained by
different neutron stars sequences from several relativistic hadronic equations
of state (GM1, GM3, TM1, NL3) and quark matter equations of state (NJL, MTI bag
model). We verify that quark stars obtained from MIT bag model with bag
constant equal to 170 MeV and quark of matter in color-superconductivity phase
are the best candidates for mass resonant detectors.


title: Gravitational red-shift and deflection of slow light

abstract:
  We explore the nature of the classical propagation of light through media
with strong frequency-dependent dispersion in the presence of a gravitational
field. In the weak field limit, gravity causes a redshift of the optical
frequency, which the slow-light medium converts into a spatially-varying index
of refraction. This results in the bending of a light ray in the medium. We
further propose experimental techniques to amplify and detect the phenomenon
using weak value measurements. Independent heuristic and rigorous derivations
of this effect are given.

categories: physics.optics gr-qc physics.class-ph quant-ph


title:
The role of magnetic fields in governing the angular momentum evolution
  of solar-type stars

abstract:
  I review the development of ideas regarding the angular momentum evolution of
solar-type stars, from the early 60's to the most recent years. Magnetic fields
are the central agent that dictates the rotational evolution of solar-type
stars, both during the pre-main sequence, through star-disk magnetic coupling,
and during the main sequence, through magnetized winds. Key theoretical
developments as well as important observational results are summarized in this
review.


title:
On the universal hydrodynamics of strongly coupled CFTs with gravity
  duals

abstract:
  It is known that the solutions of pure classical 5D gravity with $AdS_5$
asymptotics can describe strongly coupled large N dynamics in a universal
sector of 4D conformal gauge theories. We show that when the boundary metric is
flat we can uniquely specify the solution by the boundary stress tensor. We
also show that in the Fefferman-Graham coordinates all these solutions have an
integer Taylor series expansion in the radial coordinate (i.e. no $log$ terms).
Specifying an arbitrary stress tensor can lead to two types of pathologies, it
can either destroy the asymptotic AdS boundary condition or it can produce
naked singularities. We show that when solutions have no net angular momentum,
all hydrodynamic stress tensors preserve the asymptotic AdS boundary condition,
though they may produce naked singularities. We construct solutions
corresponding to arbitrary hydrodynamic stress tensors in Fefferman-Graham
coordinates using a derivative expansion. In contrast to Eddington-Finkelstein
coordinates here the constraint equations simplify and at each order it is
manifestly Lorentz covariant. The regularity analysis, becomes more elaborate,
but we can show that there is a unique hydrodynamic stress tensor which gives
us solutions free of naked singularities. In the process we write down explicit
first order solutions in both Fefferman-Graham and Eddington-Finkelstein
coordinates for hydrodynamic stress tensors with arbitrary $\eta/s$. Our
solutions can describe arbitrary (slowly varying) velocity configurations. We
point out some field-theoretic implications of our general results.


title:
Nearby Spiral Galaxy Globular Cluster Systems II: Globular Cluster
  Abundances in NGC 300

abstract:
  We present new metallicity estimates for globular cluster (GC) candidates in
the Sd spiral NGC 300, one of the nearest spiral galaxies outside the Local
Group. We have obtained optical spectroscopy for 44 Sculptor Group GC
candidates with the Boller and Chivens (B&C) spectrograph on the Baade
Telescope at Las Campanas Observatory. There are 2 GCs in NGC 253 and 12
objects in NGC 300 with globular-cluster-like spectral features, 9 of which
have radial velocities above 0 km/s. The remaining three, due to their radial
velocities being below the expected 95% confidence limit for velocities of NGC
300 halo objects, are flagged as possible foreground stars. The non-clusterlike
candidates included 13 stars, 15 galaxies, and an HII region. One GC, four
galaxies, two stars, and the HII region from our sample were identified in
archival Hubble Space Telescope images. For the GCs, we measure spectral
indices and estimate metallicities using an empirical calibration based on
Milky Way GCs. The GCs of NGC 300 appear similar to those of the Milky Way.
Excluding possible stars and including clusters from the literature, the GC
system (GCS) has a velocity dispersion of 68 km/s, and has no clear evidence of
rotation. The mean metallicity for our full cluster sample plus one literature
object is [Fe/H] = -0.94, lying above the relationship between mean GC
metallicity and overall galaxy luminosity. Excluding the three low-velocity
candidates, we obtain a mean [Fe/H] = -0.98, still higher than expected,
raising the possibility of significant foreground star contamination even in
this sample. Visual confirmation of genuine GCs using high-resolution
space-based imagery could greatly reduce the potential problem of interlopers
in small samples of GCSs in low-radial-velocity galaxies.


title:
M_T2-assisted on-shell reconstruction of missing momenta and its
  application to spin measurement at the LHC

abstract:
  We propose a scheme to assign a 4-momentum to each WIMP in new physics event
producing a pair of mother particles each of which decays to an invisible
weakly interacting massive particle (WIMP) plus some visible particle(s). The
transverse components are given by the value that determines the event variable
M_T2, while the longitudinal component is determined by the on-shell condition
on the mother particle. Although it does not give the true WIMP momentum in
general, this M_T2-assisted on-shell reconstruction of missing momenta provides
kinematic variables well correlated to the true WIMP momentum, and thus can be
useful for an experimental determination of new particle properties. We apply
this scheme to some processes to measure the mother particle spin, and find
that spin determination is possible even without a good knowledge of the new
particle masses.


title: Pseudodynamical evolution and path integral in quantum field theory

abstract:
  Using the notion of distribution on an infinite dimensional space defined in
our previous paper, we give definition of a version of dynamical evolution in
quantum field theory, motivated by heuristic formulas involving path integrals.


title: GRB060614: a "fake" short GRB from a merging binary system

abstract:
  (Shortened) CONTEXT: [...] GRB060614 is the first nearby long duration GRB
clearly not associated to a bright Ib/c supernova. Moreover, its duration
(T_{90} ~ 100s) makes it hardly classifiable as a short GRB. It presents strong
similarities with GRB970228, the prototype of the new class of "fake" short
GRBs that appear to originate from the coalescence of binary neutron stars or
white dwarfs spiraled out into the galactic halo. AIMS: Within the "canonical"
GRB scenario based on the "fireshell" model, we test if GRB060614 can be a
"fake" or "disguised" short GRB. [...] METHODS: We fit GRB060614 light curves
in Swift's BAT (15-150keV) and XRT (0.2-10keV) energy bands. Within the
fireshell model, light curves are formed by two well defined and different
components: the Proper-GRB (P-GRB), emitted at the fireshell transparency, and
the extended afterglow, due to the interaction between the leftover accelerated
baryonic and leptonic shell and the CBM. RESULTS: We determine the two free
parameters describing the GRB source within the fireshell model. [...] A small
average CBM density [...] is inferred, typical of galactic halos. The first
spikelike emission is identified with the P-GRB and the following prolonged
emission with the extended afterglow peak.[...] CONCLUSIONS: The anomalous
GRB060614 finds a natural interpretation within our canonical GRB scenario: it
is a "disguised" short GRB. [...] This result points to an old binary system,
likely formed by a white dwarf and a neutron star, as the progenitor of
GRB060614 and well justify the absence of an associated SN Ib/c. Particularly
important for further studies of the final merging process are the temporal
structures in the P-GRB down to 0.1s.


title:
Abrupt Emergence of Pressure-Induced Superconductivity of 34 K in
  SrFe2As2: A Resistivity Study under Pressure

abstract:
  We report resistivity measurement under pressure in single crystals of
SrFe_2As_2, which is one of the parent materials of Fe-based superconductors.
The structural and antiferromagnetic (AFM) transition of T_0 = 198 K at ambient
pressure is suppressed under pressure, and the ordered phase disappears above
P_c ~ 3.6-3.7 GPa. Superconductivity with a sharp transition appears
accompanied by the suppression of the AFM state. T_c exhibits a maximum of 34.1
K, which is realized close to the phase boundary at P_c. This T_c is the
highest among those of the stoichiometric Fe-based superconductors.


title:
Theory of the hourglass dispersion of magnetic excitations in high-T$_c$
  cuprates

abstract:
  A theory for the dispersion of collective magnetic excitations in
superconducting cuprates is presented with the aim to cover both high and low
doping regimes. Besides of spin fluctuations describable in the random phase
approximation (RPA) we allow for local spin rotations within a mode-coupling
theory. At low temperatures and moderately large correlation lengths we obtain
two branches of excitations which disperse up- and downwards exhibiting the
hourglass behavior observed experimentally at intermediate dopings. At large
and small dopings our theory essentially reduces to the RPA and spin wave
theory, respectively.


title: Leptoquarks in FCNC charm decays

abstract:
  Recently it was noticed that among many scenarios of new physics leptoquarks
might compensate for the disagreement between the lattice and experimental
results for the charmed strange meson decay constant. The leptoquarks might
modify also the flavor changing neutral current charm decays. In this study we
investigate impact of the scalar leptoquark with electric charge -1/3 on the
dilepton invariant mass distribution in the D^+ --> pi^+ mu^+ mu^- decay and on
the branching ratios of the D^0 --> mu^+ mu^- using the existing experimental
results.


title: Gromov-Witten invariants for G/B and Pontryagin product for \Omega K

abstract:
  We give an explicit formula for (T-equivariant) 3-pointed genus zero
Gromov-Witten invariants for G/B.
  We derive it by finding an explicit formula for the equivariant Pontryagin
product on the homology of the based loop group \Omega K.


title: Inference of higher order substitution dynamics by Markov chain lumping

abstract:
  We apply Markov chain lumping techniques to aggregate codons from an
empirical substitution matrix. The standard genetic code as well as higher
order amino acid substitution groups are identified. Since the aggregates are
derived from first principles they do not rely on system dependent assumptions
made beforehand, e.g. regarding criteria on what should constitute an amino
acid group. We therefore argue that the acquired aggregations more accurately
capture the multi-level structure of the substitution dynamics than alternative
techniques.


title:
Observing Strongly Interacting Vector Boson Systems at the CERN Large
  Hadron Collider

abstract:
  We explore the potential of the CERN Large Hadron Collider to access a
strongly interacting electroweak symmetry breaking sector via weak boson
scattering with WWjj, ZZjj and WZjj final states. As examples of models with
scalar or vector resonances we concentrate on a scenario with a heavy Higgs
boson and on a Warped Higgsless Kaluza-Klein model of narrow spin-one
resonances. The signal and the most prominent background processes are
evaluated using exact tree-level matrix elements including full off-shell and
finite width effects for final states with two tagging jets and four leptons.
Using double forward jet-tagging techniques, we derive dedicated cuts on the
observable jets and charged leptons to suppress Standard Model backgrounds. We
demonstrate that the LHC has substantial sensitivity to strong interactions in
the electroweak symmetry breaking sector.


title:
Strongly reshaped organic-metal interfaces: Tetracyanoethylene on
  Cu(100)

abstract:
  The interaction of the strong electron-acceptor tetracyanoethylene (TCNE)
with the Cu(100) surface has been studied with scanning tunneling microscopy
experiments and first-principles density functional theory calculations. We
compare two different adsorption models with the experimental results and show
that the molecular self-assembly is caused by a strong structural modification
of the Cu(100) surface rather than the formation of a coordination network by
diffusing Cu adatoms. Surface atoms become highly buckled and the chemisorption
of TCNE is accompanied by a partial charge-transfer.


title: Constraining Modified Gravity and Growth with Weak Lensing

abstract:
  The idea that we live in a Universe undergoing a period of acceleration is a
strongly held notion in cosmology. As this can, potentially, be explained with
a modification to General Relativity we look at current cosmological data with
the purpose of testing aspects of gravity. Firstly we constrain a
phenomenological model (mDGP) motivated by a possible extra dimension. This is
characterised by $\alpha$ which interpolates between (LCDM) and (the Dvali
Gabadadze Porrati (DGP) model). In addition, we analyse general signatures of
modified gravity given by the growth parameter $\gamma$ and power spectrum
parameter $\Sigma$. We utilise Weak Lensing data (CFHTLS-wide) in combination
with Baryon Acoustic Oscillations (BAOs) and Supernovae data. We show that
current weak lensing data is not yet capable of constraining either model in
isolation. However we demonstrate that this probe is highly beneficial, for in
combination with BAOs and Supernovae we obtain $\alpha < 0.58$ and $\alpha <
0.91$ at $1\sigma$ and $2\sigma$, respectively. Without the lensing data no
constraint is possible. Both analyses disfavour the flat DGP braneworld model
($\alpha = 1$) at over $2\sigma$. We highlight these are insensitive to
potential systematics in the lensing data. For the growth signature $\gamma$ we
show that, in combination, these probes do not yet have sufficient constraining
power. Finally, we look beyond these present capabilities and demonstrate that
Euclid, a future weak lensing survey, will deeply probe the nature of gravity.
A $1\sigma$ error of 0.104 is found for $\alpha$ ($l_{max} = 500$) whereas for
the general modified signatures we forecast $1\sigma$ errors of 0.045 for
$\gamma$ and 0.25 for $\Sigma_{0}$ ($l_{max} = 500$), which is further
tightened to 0.038 for $\gamma$ and 0.069 for $\Sigma_{0}$ ($l_{max} = 10000$).


title: Implications of the VHE Gamma-Ray Detection of the Quasar 3C279

abstract:
  The MAGIC collaboration recently reported the detection of the quasar 3C279
at > 100 GeV gamma-ray energies. Here we present simultaneous optical (BVRI)
and X-ray (RXTE PCA) data from the day of the VHE detection and discuss the
implications of the snap-shot spectral energy distribution for jet models of
blazars. A one-zone synchrotron-self-Compton origin of the entire SED,
including the VHE gamma-ray emission can be ruled out. The VHE emission could,
in principle, be interpreted as Compton upscattering of external radiation
(e.g., from the broad-line regions). However, such an interpretation would
require either an unusually low magnetic field of B ~ 0.03 G or an
unrealistically high Doppler factor of Gamma ~ 140. In addition, such a model
fails to reproduce the observed X-ray flux. This as well as the lack of
correlated variability in the optical with the VHE gamma-ray emission and the
substantial gamma-gamma opacity of the BLR radiation field to VHE gamma-rays
suggests a multi-zone model. In particular, an SSC model with an emission
region far outside the BLR reproduces the simultaneous X-ray -- VHE gamma-ray
spectrum of 3C279. Alternatively, a hadronic model is capable of reproducing
the observed SED of 3C279 reasonably well. However, the hadronic model requires
a rather extreme jet power of L_j ~ 10^{49} erg s^{-1}, compared to a
requirement of L_j ~ 2 X 10^{47} erg s^{-1} for a multi-zone leptonic model.


title: Emergence of Antiferromagnetic Correlation in LiTi2-xVxO4 via 7Li NMR

abstract:
  We report 7Li NMR studies of V-substitution effects on spinel oxide
superconductor LiTi2O4 (Tc = 13.4 K). In LiTi2-xVxO4 (x = 0-0.4), the V
substitution for the Ti site suppressed the relative volume fraction of
superconductivity faster than Tc. From the observation of fairly homogeneous
enhancement in a 7Li nuclear spin-lattice relaxation rate, we conclude that the
V substitution changes electron correlation effects through electron carrier
doping from quarter electron filling 3d0.5 to 3d1.5 and then the
antiferromagnetic correlation emerges.


title: Hom-bialgebras and comodule Hom-algebras

abstract:
  We study Hom-bialgebras and objects admitting coactions by Hom-bialgebras. In
particular, we construct a Hom-bialgebra M representing the functor of
2x2-matrices on Hom-associative algebras. Then we construct a Hom-algebra
analogue of the affine plane and show that it is a comodule Hom-algebra over M
in a suitable sense. It is also shown that the enveloping Hom-associative
algebra of a Hom-Lie algebra is naturally a Hom-bialgebra.


title: On Systems of Equations over Free Partially Commutative Groups

abstract:
  Version 2: Corrected Section 3.3: instead of lexicographical normal forms we
now use a normal form due to V. Diekert and A. Muscholl. Consequent changes
made and some misprints corrected.
  Using an analogue of Makanin-Razborov diagrams, we give an effective
description of the solution set of systems of equations over a partially
commutative group (right-angled Artin group) $G$. Equivalently, we give a
parametrisation of $Hom(H, G)$, where $H$ is a finitely generated group.


title: Properties of Turbulence with Zero and Nonzero Helicity

abstract:
  The present paper deals with the study of spectral properties of the helical
mode of uniform isotropic turbulence in the presence and in the absence of mean
helicity. It is shown that even in the absence of mean helicity, the helicity
of individual helical modes affects the spectral behavior of turbulence.
Besides, it is shown that both in the presence and in the absence of mean
helicity, intermediate characteristic scales connected with the presence of
helicity in helical modes should exist. The existence of these scales makes it
possible to solve the problem of helicity dissipation divergence for individual
helical modes.


title: Density gradients for the exchange energy of electrons in two dimensions

abstract:
  We derive a generalized gradient approximation to the exchange energy to be
used in density functional theory calculations of two-dimensional systems. This
class of approximations has a long and successful history, but it has not yet
been fully investigated for electrons in two dimensions. We follow the approach
originally proposed by Becke for three-dimensional systems [Int. J. Quantum
Chem. 23, 1915 (1983), J. Chem. Phys. 85, 7184 (1986)]. The resulting
functional depends on two parameters that are adjusted to a test set of
parabolically confined quantum dots. Our exchange functional is then tested on
a variety of systems with promising results, reducing the error in the exchange
energy by a factor of 4 with respect to the simple local density approximation.


title:
Elementary equivalence of right-angled Coxeter groups and graph products
  of finite abelian groups

abstract:
  We show that graph products of finite abelian groups are elementarily
equivalent if and only if they are $\exists\forall$-equivalent if and only if
they are isomorphic. In particular, two right-angled Coxeter groups are
elementarily equivalent if and only if they are isomorphic.


title:
Hybrid resonant phenomenon in a metamaterial structure with integrated
  resonant magnetic material

abstract:
  We explore the hybridization of fundamental material resonances with the
artificial resonances of metamaterials. A hybrid structure is presented in the
waveguide environment that consists of a resonant magnetic material with a
characteristic tuneable gyromagnetic response that is integrated into a
complementary split ring resonator (CSRR) metamaterial structure. The combined
structure exhibits a distinct hybrid resonance in which each natural resonance
of the CSRR is split into a lower and upper resonance that straddle the
frequency for which the magnetic material's permeability is zero. We provide an
analytical understanding of this hybrid resonance and define an effective
medium theory for the combined structure that demonstrates good agreement with
numerical electromagnetic simulations. The designed structure demonstrates the
potential for using a ferrimagnetic or ferromagnetic material as a means of
creating a tunable metamaterial structure.


title:
Spin polarized two-dimensional electron gas embedded in semimagnetic
  quantum well : ground state, spin responses, spin excitations, Raman spectrum

abstract:
  We present theoretical aspects of spin polarized two dimensional electron gas
(SP2DEG) which can be achieved in doped semimagnetic quantum wells. This
original model system has been recently studied by magneto Raman scattering
experiments has given a new access to spin resolved excitations and spectrum of
the SP2DEG. Starting from the Diluted Magnetic Semiconductor (DMS) Hamiltonian
in presence of the Coulomb interaction between conduction electrons, we define
the conditions to reach such a SP2DEG. The equilibrium state is studied at low
temperature; in particular a theory for the degree of spin polarization is
derived. Dynamical spin susceptibilities are further calculated in the
framework of a spin density functional formalism already developed in the past.
We then derive spin conserving and spin flip excitations dispersions using a
recent determination of the SP2DEG correlation energy corrected from the
thickness of the well. The SP2DEG presents two key features: the spin flip
wave, which existence is a direct consequence of the Coulomb interaction
between the spin polarized electrons, with a dispersion and energy range
typical to the SP2DEG obtained in DMS, the spin density fluctuations exhibiting
a specific collective behaviour when the spin polarization is increased. The
dissipation spectrum through these excitations is studied in detail. Particular
attention is given to the spectrum determined by resonant Raman scattering. We
show, indeed, that the latter gives unique access to the spin-fluctuations
spectrum of the SP2DEG.


title:
Multiwavelength Signatures of Magnetic Activity from Young Stellar
  Objects in the LkH\alpha101 Cluster

abstract:
  [abridged] We describe the results of our multi-wavelength observing campaign
on the young stellar objects in the LkH$\alpha$101 cluster. Our simultaneous
X-ray and multi-frequency radio observations are unique in providing
simultaneous constraints on short-timescale variability at both wavelengths as
well as constraints on the thermal or nonthermal nature of radio emission from
young stars. Focussing in on radio-emitting objects and the multi-wavelength
data obtained for them, we find that multi-frequency radio data indicate
nonthermal emission even in objects with infrared evidence for disks. We find
radio variability on timescales of decades, days and hours. About half of the
objects with X-ray and radio detections were variable at X-ray wavelengths,
despite lacking large-scale flares or large variations. Variability appears to
be a bigger factor affecting radio emission than X-ray emission. A star with
infrared evidence for a disk, [BW88]~3, was observed in the decay phase of a
radio flare. In this object and another ([BW88]~1), we find an inverse
correlation between radio flux and spectral index which contrasts with behavior
seen in the Sun and active stars. We interpret this behavior as the
repopulation of the hardest energy electrons due to particle acceleration. A
radio and X-ray source lacking an infrared counterpart, [BW88]~1, may be near
the substellar limit; its radio properties are similar to other cluster
members, but its much higher radio to X-ray luminosity ratio is reminiscent of
behavior in nearby very low mass stars/brown dwarfs. We find no correspondence
between signatures of particle acceleration and those of plasma heating, both
time-averaged and time-variable. The lack of correlated temporal variability in
multi-wavelength behavior, the breakdown of multi-wavelength correlations of...


title: On the Mathematical Theory of Superfluidity

abstract:
  We provide a general operator algebraic formulation of superfluidity in Bose
systems, with the aim of investigating the relationships of this phenomenon
both to off-diagonal long range order (ODLRO) and to a mathematically precise
version of Landau's picture of elementary excitations. Our principal results
are that ODLRO leads both to rotational superfluidity and to Goldstone
excitations, while the neo-Landau picture accounts for the translational
superfluidity of flow along a pipe. The latter picture is realised by the
Lieb-Liniger-Girardeau model. Open problems are briefly discussed.


title: Masaki Kashiwara and Algebraic Analysis

abstract:
  This paper is a brief overview of the main contributions of Masaki Kashiwara
in the domain of microlocal and algebraic analysis.


title: Measurement of Heavy Flavor and Quarkonia Production by PHENIX

abstract:
  Heavy quarks (charm and bottom) are good probes of the hot and dense medium
created in relativistic heavy ion collisions since they are mainly generated at
the beginning of collisions and interact with the media in all collision
stages. In addition, heavy flavor quarkonia production is thought to be
uniquely sensitive to the deconfined medium of the Quark Gluon Plasma (QGP)
through color screening. Heavy quark production has been studied by the PHENIX
experiment at RHIC via measurements of single leptons from semi-leptonic decays
in both the electron channel at mid-rapidity and in the muon channel at
forward-rapidity. Large suppression and azimuthal anisotropy of single
electrons have been observed in Au+Au collisions at sqrt(s) = 200 GeV. These
results suggest a large energy loss and flow of the heavy quarks in the hot,
dense matter. The PHENIX experiment has also measured J/psi production up to
sqrt(s) = 200 GeV in p+p, d+Au, Cu+Cu and Au+Au collisions, both at mid
(|y|<0.35) and forward (1.2<|y|<2.2) rapidities. In the most energetic
collisions (central Au+Au), more suppression is observed at forward rapidity
than at central rapidity. This can be interpreted either as a sign of quark
recombination, or as a hint of additional cold nuclear matter effects. The
current status and understanding of all these measurements will be reviewed.


title: Observing The Hidden Sector

abstract:
  We study the effects of renormalization due to hidden-sector dynamics on
observable soft supersymmetry-breaking parameters in the minimal supersymmetric
extension of the Standard Model (MSSM), under various hypotheses about their
universality at a high input scale. We show that hidden-sector renormalization
effects may induce the spurious appearance of unification of the scalar masses
at some lower scale, as in mirage unification scenarios. We demonstrate in
simple two-parameter models of the hidden-sector dynamics that the parameters
may in principle be extracted from experimental measurements, rendering the
hidden sector observable. We also discuss the ingredients that would be
necessary to carry this programme out in practice.


title: Shcherbina's Theorem for Finely Holomorphic Functions

abstract:
  We prove an analogue of Sadullaev's theorem concerning the size of the set
where a maximal totally real manifold can meet a pluripolar set. The manifold
has to be of class C-1 only. This readily leads to a version of Shcherbina's
theorem for C-1 functions f that are defined in a neighborhood of certain
compact sets K in the complex plane. If the graph of f on K is pluripolar, then
f satisfies the Cauchy Riemann equations in the closure of the fine interior of
K.


title:
The profile of bubbling solutions of a class of fourth order geometric
  equations on 4-manifolds

abstract:
  We study a class of fourth order geometric equations defined on a
4-dimensional compact Riemannian manifold which includes the Q-curvature
equation. We obtain sharp estimates on the difference near the blow-up points
between a bubbling sequence of solutions and the standard bubble.


title: Density and spin response function of a normal Fermi gas at unitarity

abstract:
  Using Landau theory of Fermi liquids we calculate the dynamic response of
both a polarized and unpolarized normal Fermi gas at zero temperature in the
strongly interacting regime of large scattering length. We show that at small
excitation energies the {\it in phase} (density) response is enhanced with
respect to the ideal gas prediction due to the increased compressibility.
Viceversa, the {\it out of phase} (spin) response is quenched as a consequence
of the tendency of the system to pair opposite spins. The long wavelength
behavior of the static structure factor is explicitly calculated. The results
are compared with the predictions in the collisional and superfluid regimes.
The emergence of a spin zero sound solution in the unpolarized normal phase is
explicitly discussed.


title: Hidden-Sector Dynamics and the Supersymmetric Seesaw

abstract:
  In light of recent analyses that have shown that nontrivial hidden-sector
dynamics in models of supersymmetry breaking can lead to a significant impact
on the predicted low-energy supersymmetric spectrum, we extend these studies to
consider hidden-sector effects in extensions of the MSSM to include a seesaw
model for neutrino masses. A dynamical hidden sector in an interval of mass
scales below the seesaw scale would yield renormalization-group running
involving both the anomalous dimension from the hidden sector and the
seesaw-extended MSSM renormalization group equations (RGEs). These effects
interfere in general, altering the generational mixing of the sleptons, and
allowing for a substantial change to the expected level of charged-lepton
flavour violation in seesaw-extended MSSM models. These results provide further
support for recent theoretical observations that knowledge of the hidden sector
is required in order to make concrete low-energy predictions, if the hidden
sector is strongly coupled. In particular, hidden-sector dynamics may impact
our ability to reconstruct the supersymmetric seesaw parameters from low-energy
observations.


title: Orientability in Yang-Mills Theory over Nonorientable Surfaces

abstract:
  In arXiv:math/0605587, the first two authors have constructed a
gauge-equivariant Morse stratification on the space of connections on a
principal U(n)-bundle over a connected, closed, nonorientable surface. This
space can be identified with the real locus of the space of connections on the
pullback of this bundle over the orientable double cover of this nonorientable
surface. In this context, the normal bundles to the Morse strata are real
vector bundles. We show that these bundles, and their associated homotopy orbit
bundles, are orientable for any n when the nonorientable surface is not
homeomorphic to the Klein bottle, and for n<4 when the nonorientable surface is
the Klein bottle. We also derive similar orientability results when the
structure group is SU(n).


title: 2PI functional techniques for abelian gauge theories

abstract:
  We summarize our recent work [1-3] concerning the formulation of
two-particle-irreducible (2PI) functional techniques for abelian gauge field
theories.


title:
The adaptability of physiological systems optimizes performance: new
  directions in augmentation

abstract:
  This paper contributes to the human-machine interface community in two ways:
as a critique of the closed-loop AC (augmented cognition) approach, and as a
way to introduce concepts from complex systems and systems physiology into the
field. Of particular relevance is a comparison of the inverted-U (or Gaussian)
model of optimal performance and multidimensional fitness landscape model.
Hypothetical examples will be given from human physiology and learning and
memory. In particular, a four-step model will be introduced that is proposed as
a better means to characterize multivariate systems during behavioral processes
with complex dynamics such as learning. Finally, the alternate approach
presented herein is considered as a preferable design alternate in
human-machine systems. It is within this context that future directions are
discussed.


title:
Symmetry Reduction in Twisted Noncommutative Gravity with Applications
  to Cosmology and Black Holes

abstract:
  As a preparation for a mathematically consistent study of the physics of
symmetric spacetimes in a noncommutative setting, we study symmetry reductions
in deformed gravity. We focus on deformations that are given by a twist of a
Lie algebra acting on the spacetime manifold. We derive conditions on those
twists that allow a given symmetry reduction. A complete classification of
admissible deformations is possible in a class of twists generated by commuting
vector fields. As examples, we explicitly construct the families of vector
fields that generate twists which are compatible with
Friedmann-Robertson-Walker cosmologies and Schwarzschild black holes,
respectively. We find nontrivial isotropic twists of FRW cosmologies and
nontrivial twists that are compatible with all classical symmetries of black
hole solutions.


title: Black Holes, AdS, and CFTs

abstract:
  This brief conference proceeding attempts to explain the implications of the
anti-de Sitter/conformal field theory (AdS/CFT) correspondence for black hole
entropy in a language accessible to relativists and other non-string theorists.
The main conclusion is that the Bekenstein-Hawking entropy S_{BH} is the
density of states associated with certain superselections sectors, defined by
what may be called the algebra of boundary observables. Interestingly, while
there is a valid context in which this result can be restated as "S_{BH} counts
all states inside the black hole," there may also be another in which it may be
restated as "$S_{BH}$ does not count all states inside the black hole, but only
those that are distinguishable from the outside." The arguments and conclusions
represent the author's translation of the community's collective wisdom,
combined with a few recent results. For the proceedings of the
WE-Heraeus-Seminar: Quantum Gravity: Challenges and Perspectives, dedicated to
the memory of John A. Wheeler.


title: Quarks in Coulomb gauge perturbation theory

abstract:
  Coulomb gauge quantum chromodynamics within the first order functional
formalism is considered. The quark contributions to the Dyson-Schwinger
equations are derived and one-loop perturbative results for the two-point
functions are presented.


title: Early stage formation of graphene on the C-face of 6H-SiC

abstract:
  An investigation of the early stage formation of graphene on the C-face of
6H-SiC is presented. We show that the sublimation of few atomic layers of Si
out of the SiC substrate is not homogeneous. In good agreement with the results
of theoretical calculations it starts from defective sites, mainly dislocations
that define nearly circular flakes, which have a pyramidal, volcano-like, shape
with a center chimney where the original defect was located. At higher
temperatures, complete conversion occurs but, again, it is not homogeneous.
Within the sample surface the intensity of the Raman G and 2D bands, evidences
non-homogeneous thickness.


title: Non-perturbative Heat Kernel Asymptotics on Homogeneous Abelian Bundles

abstract:
  We study the heat kernel for a Laplace type partial differential operator
acting on smooth sections of a complex vector bundle with the structure group
$G\times U(1)$ over a Riemannian manifold $M$ without boundary. The total
connection on the vector bundle naturally splits into a $G$-connection and a
U(1)-connection, which is assumed to have a parallel curvature $F$. We find a
new local short time asymptotic expansion of the off-diagonal heat kernel
$U(t|x,x')$ close to the diagonal of $M\times M$ assuming the curvature $F$ to
be of order $t^{-1}$. The coefficients of this expansion are polynomial
functions in the Riemann curvature tensor (and the curvature of the
$G$-connection) and its derivatives with universal coefficients depending in a
non-polynomial but analytic way on the curvature $F$, more precisely, on $tF$.
These functions generate all terms quadratic and linear in the Riemann
curvature and of arbitrary order in $F$ in the usual heat kernel coefficients.
In that sense, we effectively sum up the usual short time heat kernel
asymptotic expansion to all orders of the curvature $F$. We compute the first
three coefficients (both diagonal and off-diagonal) of this new asymptotic
expansion.


title:
The effect of nearest neighbor spin-singlet correlations in conventional
  graphene SNS Josephson junctions

abstract:
  Using the self-consistent tight-binding Bogoliubov-de Gennes formalism we
have studied the effect of nearest neighbor spin-singlet bond (SB) correlations
on Josephson coupling and proximity effect in graphene SNS Josephson junctions
with conventional s-wave superconducting contacts. Despite the s-wave
superconducting state in the contacts, the SB pairing state inside the junction
has d-wave symmetry and clean, sharp interface junctions resemble a
'bulk-meets-bulk' situation with very little interaction between the two
different superconducting states. In fact, due to a finite-size suppression of
the superconducting state, a stronger SB coupling constant than in the bulk is
needed in order to achieve SB pairing in a junction. For both short clean
zigzag and armchair junctions a d-wave state that has a zero Josephson coupling
to the s-wave state is chosen and therefore the Josephson current decreases
when a SB pairing state develops in these junctions. In more realistic
junctions, with smoother doping profiles and atomic scale disorder at the
interfaces, it is possible to achieve some coupling between the contact s-wave
state and the SB d-wave states. In addition, by breaking the appropriate
lattice symmetry at the interface in order to induce another d-wave state, a
non-zero Josephson coupling can be achieved which leads to a substantial
increase in the Josephson current. We also report on the LDOS of the junctions
and on a lack of zero energy states at interfaces despite the unconventional
order parameters, which we attribute to the near degeneracy of the two d-wave
solutions and their mixing at a general interface.


title:
Why Do Granular Materials Stiffen with Shear Rate? A Test of Novel
  Stress-Based Statistics

abstract:
  Recent experiments exhibit a rate-dependence for granular shear such that the
stress grows linearly in the logarithm of the shear rate, \dot{\gamma}.
Assuming a generalized activated process mechanism, we show that these
observations are consistent with a recent proposal for a stress-based
statistical ensemble. By contrast, predictions for rate-dependence using
conventional energy-based statistical mechanics to describe activated
processes, predicts a rate dependence that of (\ln (\dot{\gamma}))^{1/2}.


title:
Molecular gas in NUclei of GAlaxies (NUGA). XI. A complete gravity
  torque map of NGC4579: new clues on bar evolution

abstract:
  We create a complete gravity torque map of the disk of the LINER/Seyfert 1.9
galaxy NGC4579. We quantify the efficiency of angular momentum transport and
search for signatures of secular evolution in the fueling process from r~15kpc
down to the inner r~50pc around the Active Galactic Nucleus (AGN). We use both
the 1-0 and 2-1 line maps of CO obtained with the Plateau de Bure
Interferometer (PdBI) as part of the NUclei of Galaxies-(NUGA)-project. We
derive the stellar potential from a NIR (K band) wide field image of the
galaxy. The K-band image, which reveals a stellar bar, together with a high
resolution HI map of NGC4579 obtained with the Very Large Array (VLA), allow us
to extend the gravity torque analysis to the outer disk. The bulk of the gas
response traced by the CO PdBI maps follows the expected gas flow pattern
induced by the bar potential in the presence of two Inner Lindblad Resonances
(ILR). We also detect an oval distortion in the inner r~200pc of the K-band
image. The oval is not aligned with the large-scale bar, a signature of
dynamical decoupling. The morphology of the outer disk suggests that the
neutral gas is currently piling up in a pseudo-ring formed by two winding
spiral arms that are morphologically decoupled from the bar structure. In the
outer disk, the decoupling of the spiral allows the gas to efficiently produce
net gas inflow on intermediate scales. The corotation barrier seems to be
overcome due to secular evolution processes. The gas in the inner disk is
efficiently funneled by gravity torques down to r~300pc. Closer to the AGN, the
two m=2 modes (bar and oval) act in concert to produce net gas inflow down to
r~50pc, providing a clear smoking gun evidence of fueling with associated short
dynamical time-scales.


title: Update of the global fit of PDFs including the low-Q DIS data

abstract:
  We perform the next-to-next-leading-order (NNLO) QCD global fit of PDFs using
inclusive charged-lepton and neutrino DIS data down to Q = 1 GeV. We also
consider the data on neutrino-nucleon dimuon production, that allows us to
disentangle the strange sea distribution. The fit results in \chi^2/NDP =
5150/4338 = 1.2 that demonstrates a good consistency of the data sets used in
analysis. The resulting value of \alpha_s(M_Z) = 0.1136+- 0.0007(exp.) is in a
good agreement with the previous version of the fit with a more stringent cut
on Q. This analysis allows us to improve the accuracy of PDFs. The HT terms of
the neutrino-nucleon structure functions F_2 and xF_3 are determined, the
former is found to be consistent with one for the charged-leptons if the charge
factor is taken into account.


title: In search of a Lebesgue density theorem for R^\infty

abstract:
  We look at a measure, $\lambda^\infty$, on the infinite-dimensional space,
${\mathbb R}^\infty$, for which we attempt to put forth an analogue of the
Lebesgue density theorem. Although this measure allows us to find partial
results, for example for continuous functions, we prove that it is impossible
to give an analogous theorem in full generality. In particular, we proved that
the Lebesgue density of probability density functions on ${\mathbb R}^\infty$
is zero almost everywhere.


title: Static Interactions of U(N) non-Abelian Vortices

abstract:
  Interactions between non-BPS non-Abelian vortices are studied in non-Abelian
U(1) x SU(N) extensions of the Abelian-Higgs model in four dimensions. In
addition to the usual type I/II Abelian superconductors, we find other two new
regimes: type I*/II*.


title:
Vanishing cycle sheaves of one-parameter smoothings and quasi-semistable
  degenerations

abstract:
  We study the vanishing cycles of a one-parameter smoothing of a complex
analytic space and show that the weight filtration on its perverse cohomology
sheaf of the highest degree is quite close to the monodromy filtration so that
its graded pieces have a modified Lefschetz decomposition. We describe its
primitive part using the weight filtration on the perverse cohomology sheaves
of the constant sheaves. As a corollary we show in the local complete
intersection case that 1 is not an eigenvalue of the monodromy on the reduced
Milnor cohomology at any points if and only if the total space and the singular
fiber are both rational homology manifolds. Also we introduce quasi-semistable
degenerations and calculate the limit mixed Hodge structure by constructing the
weight spectral sequence. As a corollary we show non-triviality of the space of
vanishing cycles of the Lefschetz pencil associated with a tensor product of
any two very ample line bundles except for the case of even-dimensional
projective space where two has to be replaced by three.


title: On the eigenfunctions of no-pair operators in classical magnetic fields

abstract:
  We consider a relativistic no-pair model of a hydrogenic atom in a classical,
exterior magnetic field. First, we prove that the corresponding Hamiltonian is
semi-bounded below, for all coupling constants less than or equal to the
critical one known for the Brown-Ravenhall model, i.e., for vanishing magnetic
fields. We give conditions ensuring that its essential spectrum equals
[1,\infty) and that there exist infinitely many eigenvalues below 1. (The rest
energy of the electron is 1 in our units.) Assuming that the magnetic vector
potential is smooth and that all its partial derivatives increase
subexponentially, we finally show that an eigenfunction corresponding to an
eigenvalue \lambda<1 is smooth away from the nucleus and that its partial
derivatives of any order decay pointwise exponentially with any rate
a<(1-\lambda^2)^{1/2}, for \lambda\in[0,1), and a<1, for \lambda<0.


title: Asymptotics of multivariate sequences, part III: quadratic points

abstract:
  We consider a number of combinatorial problems in which rational generating
functions may be obtained, whose denominators have factors with certain
singularities. Specifically, there exist points near which one of the factors
is asymptotic to a nondegenerate quadratic. We compute the asymptotics of the
coefficients of such a generating function. The computation requires some
topological deformations as well as Fourier-Laplace transforms of generalized
functions. We apply the results of the theory to specific combinatorial
problems, such as Aztec diamond tilings, cube groves, and multi-set
permutations.


title: Predictions of Neutrino Mixing Angles in a T'Model

abstract:
  Flavor symmetry ($T^{'} \times Z_2$) where $T^{'}$ is the binary tetrahedral
group predicts for neutrino mixing angles $\theta_{13} = \sqrt{2}
(\frac{\pi}{4} - \theta_{23})$ and, with one phenomenological input, provides
upper and lower bounds on both $\theta_{13}$ and $\theta_{23}$. The predictions
arise from the deviation of the Cabibbo angle $\Theta_{12}$ from its
lowest-order value $\tan 2\Theta_{12} = (\sqrt{2})/3$ and from the $T^{'}$
mechanism which relates mixing of $(\nu_{\tau}, \nu_{\mu}, \nu_e)$ neutrinos to
mixing of $(s, d)$ quarks.


title: SO and USp (Hyper)Kahler Quotients and Lumps

abstract:
  The properties of supersymmetric gauge theories in the Higgs phase at low
energies can appropriately be studied by means of a non-linear sigma model,
which has the target space being Kahler for N=1 supersymmetric models and
hyperKahler for N=2 models. By construction of the Kahler and hyperKahler
quotients for the gauge theories with SO and USp gauge symmetries, we obtain
the explicit metrics on their respective manifolds. Furthermore, we study the
lumps in the non-linear sigma models and their effective description, using the
Kahler quotients.


title: Klazar trees and perfect matchings

abstract:
  Martin Klazar computed the total weight of ordered trees under 12 different
notions of weight. The last and perhaps most interesting of these weights,
w_{12}, led to a recurrence relation and an identity for which he requested
combinatorial explanations. Here we provide such explanations. To do so, we
introduce the notion of a "Klazar violator" vertex in an increasing ordered
tree and observe that w_{12} counts what we call Klazar trees--increasing
ordered trees with no Klazar violators. A highlight of the paper is a bijection
from n-edge increasing ordered trees to perfect matchings of [2n]={1,2,...,2n}
that sends Klazar violators to even numbers matched to a larger odd number. We
find the distribution of the latter matches and, in particular, establish the
one-summation explicit formula sum_{k=1}^{lfloor n/2 rfloor}(2k-1)!!^2
StirlingPartition{n+1}{2k+1} for the number of perfect matchings of [2n] with
no even-to-larger-odd matches. The proofs are mostly bijective.


title: On the Study of Richard Tom Robert Identity

abstract:
  In order to estimate the average speed of mosquitoes, a simple experiment was
designed by Richard (Lu-Hsing Tsai), Tom (Po-Yu Tsai) and Robert (Hung-Ming
Tsai). The result of the experiment was posted in the science exhibitions
Taichung Taiwan 1993. The average speed of mosquitoes is inferred by the simple
relation that is obtained easily. In this paper, we will show how the data
generated by computer. Though the rigorous proof is not shown, a sketch proof
will be shown in this paper. There are five figures one table and one fortran
computer source program in the end of the paper.


title: The direction of time in quantum field theory

abstract:
  The algebra of observables associated with a quantum field theory is
invariant under the connected component of the Lorentz group and under parity
reversal, but it is not invariant under time reversal. If we take general
covariance seriously as a long-term goal, the algebra of observables should be
time-reversal invariant, and any breaking of time-reversal symmetry will have
to be described by the state over the algebra. In consequence, the modified
algebra of observables is a presentation of a classical continuous random
field.


title: On Finite Bases for Weak Semantics: Failures versus Impossible Futures

abstract:
  We provide a finite basis for the (in)equational theory of the process
algebra BCCS modulo the weak failures preorder and equivalence. We also give
positive and negative results regarding the axiomatizability of BCCS modulo
weak impossible futures semantics.


title:
Systematic tight-binding analysis of ARPES spectra of transition-metal
  oxides

abstract:
  We have performed systematic tight-binding (TB) analyses of the
angle-resolved photoemission spectroscopy (ARPES) spectra of transition-metal
(TM) oxides A$M$O$_3$ ($M=$ Ti, V, Mn, and Fe) with the perovskite-type
structure and compared the obtained parameters with those obtained from
configuration-interaction (CI) cluster-model analyses of photoemission spectra.
The values of $\epsilon_d-\epsilon_p$ from ARPES are found to be similar to the
charge-transfer energy $\Delta$ from O $2p$ orbitals to empty TM 3d orbitals
and much larger than $\Delta-U/2$ ($U$: on-site Coulomb energy) expected for
Mott-Hubbard-type compounds including SrVO$_3$. $\epsilon_d-\epsilon_p$ values
from {\it ab initio} band-structure calculations show similar behaviors to
those from ARPES. The values of the $p-d$ transfer integrals to describe the
global electronic structure are found to be similar in all the estimates,
whereas additional narrowing beyond the TB description occurs in the ARPES
spectra of the $d$ band.


title: Determining the Neutral D Mixing Parameters

abstract:
  Evidence for mixing in the neutral D meson system has recently been reported.
Assuming negligible CP violation, non-vanishing width and mass differences
between the two neutral D mass eigenstates has been found. Theoretical
predictions of these are rather difficult, obscuring detection of New Physics
contributions. However, the observation of CP violation in the D system would
be a good signal of New Physics. We briefly describe the formalism that
describes the neutral D decay and mixing, and present a method to determine all
the mixing parameters accurately allowing for arbitrary CP violation.