title:
Relativistic Effects of Mixed Vector-Scalar-Pseudoscalar Potentials for
  Fermions in 1+1 Dimensions

abstract:
  The problem of fermions in the presence of a pseudoscalar plus a mixing of
vector and scalar potentials which have equal or opposite signs is
investigated. We explore all the possible signs of the potentials and discuss
their bound-state solutions for fermions and antifermions. The cases of mixed
vector and scalar P\"{o}schl-Teller-like and pseudoscalar kink-like potentials,
already analyzed in previous works, are obtained as particular cases.


title: Grain Boundary Diffusion in a Peierls-Nabarro Potential

abstract:
  We investigate the diffusion of a grain boundary in a crystalline material.
We consider in particular the case of a regularly spaced low-angle grain
boundary schematized as an array of dislocations that interact with each other
through long-range stress fields and with the crystalline Peierls-Nabarro
potential. The methodology employed to analyze the dynamics of the center of
mass of the grain boundary and its spatio-temporal fluctuations is based on
over-damped Langevin equations. The generality and the efficiency of this
technique is proved by the agreement with molecular dynamics simulations.


title: String-Like Lagrangians from a Generalized Geometry

abstract:
  This note will use Hitchin's generalized geometry and a model of axionic
gravity developed by Warren Siegel in the mid-nineties to show that the
construction of Lagrangians based on the inner product arising from the pairing
of a vector and its dual can lead naturally to the low-energy Lagrangian of the
bosonic string.


title: The Fractional Chapman-Kolmogorov Equation

abstract:
  The Chapman-Kolmogorov equation with fractional integrals is derived. An
integral of fractional order is considered as an approximation of the integral
on fractal. Fractional integrals can be used to describe the fractal media.
Using fractional integrals, the fractional generalization of the
Chapman-Kolmogorov equation is obtained. From the fractional Chapman-Kolmogorov
equation, the Fokker-Planck equation is derived.


title:
Tridiagonal canonical matrices of bilinear or sesquilinear forms and of
  pairs of symmetric, skew-symmetric, or Hermitian forms

abstract:
  Tridiagonal canonical forms of square matrices under congruence or
*congruence, pairs of symmetric or skew-symmetric matrices under congruence,
and pairs of Hermitian matrices under *congruence are given over an
algebraically closed field of characteristic different from 2.


title: Band Unfoldings and Prismatoids: A Counterexample

abstract:
  This note shows that the hope expressed in [ADL+07]--that the new algorithm
for edge-unfolding any polyhedral band without overlap might lead to an
algorithm for unfolding any prismatoid without overlap--cannot be realized. A
prismatoid is constructed whose sides constitute a nested polyhedral band, with
the property that every placement of the prismatoid top face overlaps with the
band unfolding.


title: Magnetic and Electric Excitations in Split Ring Resonators

abstract:
  We studied the electric and magnetic resonance of U-shaped SRRs. We showed
that higher order excitation modes exist in both of the electric and magnetic
resonances. The nodes in the current distribution were found for all the
resonance modes. It turns out that the magnetic resonances are the modes with
odd-number of half-wavelength of the current wave, i.e. 1/2, 3/2 and 5/2
wavelengths modes, and the electric resonances are modes with integer number of
whole-wavelength of current wave, i.e. 1, 2 and 3 wavelengths modes. We
discussed the electric moment and magnetic moment of the electric and magnetic
resonances, and their dependence to the length of two parallel side arms. We
show that the magnetic moment of magnetic resonance vanishes as the length side
arms of the SRR reduces to zero, i.e. a rod does not give any magnetic moment
or magnetic resonance.


title: Valuation domains whose products of free modules are separable

abstract:
  It is proved that if $R$ is a valuation domain with maximal ideal $P$ and if
$R_L$ is countably generated for each prime ideal $L$, then $R^R$ is separable
if and only $R_J$ is maximal, where $J=\cap_{n\in\mathbb{N}}P^n$.


title: Dynamical systems analysis of anisotropic cosmologies in $R^n$-gravity

abstract:
  In this paper we study the dynamics of {\it orthogonal spatially homogeneous}
Bianchi cosmologies in $R^n$-gravity. We construct a compact state space by
dividing the state space into different sectors. We perform a detailed analysis
of the cosmological behaviour in terms of the parameter $n$, determining all
the equilibrium points, their stability and corresponding cosmological
evolution. In particular, the appropriately compactified state space allows us
to investigate static and bouncing solutions. We find no Einstein static
solutions, but there do exist cosmologies with bounce behaviours. We also
investigate the isotropisation of these models and find that all isotropic
points are flat Friedmann like.


title:
Canonical form of m-by-2-by-2 matrices over a field of characteristic
  other than two

abstract:
  We give a canonical form of m-by-2-by-2 matrices for equivalence over any
field of characteristic not two.


title:
WKB analysis for the Gross-Pitaevskii equation with non-trivial boundary
  conditions at infinity

abstract:
  We consider the semi-classical limit for the Gross-Pitaevskii equation. In
order to consider non-trivial boundary conditions at infinity, we work in
Zhidkov spaces rather than in Sobolev spaces. For the usual cubic nonlinearity,
we obtain a point-wise description of the wave function as the Planck constant
goes to zero, so long as no singularity appears in the limit system. For a
cubic-quintic nonlinearity, we show that working with analytic data may be
necessary and sufficient to obtain a similar result.


title:
The radio lighthouse CU Virginis: the spindown of a single main sequence
  star

abstract:
  The fast rotating star CU Virginis is a magnetic chemically peculiar star
with an oblique dipolar magnetic field. The continuum radio emission has been
interpreted as gyrosyncrotron emission arising from a thin magnetospheric
layer. Previous radio observations at 1.4 GHz showed that a 100% circular
polarized and highly directive emission component overlaps to the continuum
emission two times per rotation, when the magnetic axis lies in the plane of
the sky. This sort of radio lighthouse has been proposed to be due to cyclotron
maser emission generated above the magnetic pole and propagating
perpendicularly to the magnetic axis. Observations carried out with the
Australia Telescope Compact Array at 1.4 and 2.5 GHz one year after this
discovery show that this radio emission is still present, meaning that the
phenomenon responsible for this process is steady on a timescale of years. The
emitted radiation spans at least 1 GHz, being observed from 1.4 to 2.5 GHz. On
the light of recent results on the physics of the magnetosphere of this star,
the possibility of plasma radiation is ruled out. The characteristics of this
radio lighthouse provides us a good marker of the rotation period, since the
peaks are visible at particular rotational phases. After one year, they show a
delay of about 15 minutes. This is interpreted as a new abrupt spinning down of
the star. Among several possibilities, a quick emptying of the equatorial
magnetic belt after reaching the maximum density can account for the magnitude
of the breaking. The study of the coherent emission in stars like CU Vir, as
well as in pre main sequence stars, can give important insight into the angular
momentum evolution in young stars. This is a promising field of investigation
that high sensitivity radio interferometers such as SKA can exploit.


title: One-loop effects in a self-dual planar noncommutative theory

abstract:
  We study the UV properties, and derive the explicit form of the one-loop
effective action, for a noncommutative complex scalar field theory in 2+1
dimensions with a Grosse-Wulkenhaar term, at the self-dual point. We also
consider quantum effects around non-trivial minima of the classical action
which appear when the potential allows for the spontaneous breaking of the U(1)
symmetry. For those solutions, we show that the one-loop correction to the
vacuum energy is a function of a special combination of the amplitude of the
classical solution and the coupling constant.


title: Compactifying the state space for alternative theories of gravity

abstract:
  In this paper we address important issues surrounding the choice of variables
when performing a dynamical systems analysis of alternative theories of
gravity. We discuss the advantages and disadvantages of compactifying the state
space, and illustrate this using two examples. We first show how to define a
compact state space for the class of LRS Bianchi type I models in $R^n$-gravity
and compare to a non--compact expansion--normalised approach. In the second
example we consider the flat Friedmann matter subspace of the previous example,
and compare the compact analysis to studies where non-compact
non--expansion--normalised variables were used. In both examples we comment on
the existence of bouncing or recollapsing orbits as well as the existence of
static models.


title:
Is the accelerated expansion evidence of a forthcoming change of
  signature on the brane?

abstract:
  We show that regular changes of signature on brane-worlds in AdS bulks may
account for some types of the recently fashionable sudden singularities.
Therefore, the possibility that the Universe seems to approach a future sudden
singularity at an accelerated rate of expansion might simply be an indication
that our braneworld is about to change from Lorentzian to Euclidean signature.
Both the brane and the bulk remain fully regular everywhere. We present a model
in which the weak and strong energy conditions hold on the brane, in contrast
with the standard cosmologies leading to the analogous kinematical behaviour
(that is, with a diverging Hubble factor).


title:
Permutahedra, HKR isomorphism and polydifferential Gerstenhaber-Schack
  complex

abstract:
  This paper aims to give a short but self-contained introduction into the
theory of (wheeled) props, properads, dioperads and operads, and illustrate
some of its key ideas in terms of a prop(erad)ic interpretation of simplicial
and permutahedra cell complexes with subsequent applications to the
Hochschild-Kostant-Rosenberg type isomorphisms.


title:
Size Dependence and Convergence of the Retrieval Parameters of
  Metamaterials

abstract:
  We study the dependence of the retrieval parameters, such as the electric
permittivity, the magnetic permeability and the index of refraction, $n$, on
the size of the unit cell of a periodic metamaterial. The convergence of the
retrieved parameters on the number of the unit cells is also examined. We have
concentrated our studies on the so-called fishnet structure, which is the most
promising design to obtain negative $n$ at optical wavelengths. We find that as
the size of the unit cell decreases, the magnitude of the retrieved effective
parameters increases. The convergence of the effective parameters of the
fishnet as the number of the unit cells increases is demonstrated but found to
be slower than for regular split ring resonators and wires structures. This is
due to a much stronger coupling between the different unit cells in the fishnet
structure.


title: Three topics in additive prime number theory

abstract:
  This is an expository article to accompany my two lectures at the CDM
conference. I have used this an excuse to make public two sets of notes I had
lying around, and also to put together a short reader's guide to some recent
joint work with T.Tao. Contents: 1. An exposition, without much detail, of the
work of Goldston, Pintz and Yildirim on gaps between primes; 2. A detailed
discussion of the work of Mauduit and Rivat establishing that 50 percent of the
primes have odd digit sum when written in base 2; 3. A reader's guide to recent
work of T.Tao and the author on linear equations in primes.
  The sections can be read independently.


title: Two algorithms in search of a type system

abstract:
  The authors' ATR programming formalism is a version of call-by-value PCF
under a complexity-theoretically motivated type system. ATR programs run in
type-2 polynomial-time and all standard type-2 basic feasible functionals are
ATR-definable (ATR types are confined to levels 0, 1, and 2). A limitation of
the original version of ATR is that the only directly expressible recursions
are tail-recursions. Here we extend ATR so that a broad range of affine
recursions are directly expressible. In particular, the revised ATR can fairly
naturally express the classic insertion- and selection-sort algorithms, thus
overcoming a sticking point of most prior implicit-complexity-based formalisms.
The paper's main work is in refining the original time-complexity semantics for
ATR to show that these new recursion schemes do not lead out of the realm of
feasibility.


title: Entanglement Witnesses from Single-Particle Interference

abstract:
  We describe a general method of realizing entanglement witnesses in terms of
the interference pattern of a single quantum probe. After outlining the
principle, we discuss specific realizations both with electrons in mesoscopic
Aharonov-Bohm rings and with photons in standard Young's double-slit or
coherent-backscattering interferometers.


title:
Next-to-leading order QCD effects in associated charged Higgs and W
  boson production in the MSSM at the CERN Large Hadron Collider

abstract:
  We present the calculations of the next-to-leading order (NLO) QCD
corrections to the inclusive total cross sections for the associated production
of the $W^{\pm}H^{\mp}$ through $b\bar{b}$ annihilation in the Minimal
Supersymmetric Standard Model at the CERN Large Hadron Collider. The NLO QCD
corrections can either enhance or reduce the total cross sections, but they
generally efficiently reduce the dependence of the total cross sections on the
renormalization/factorization scale. The magnitude of the NLO QCD corrections
is about 10% in most of the parameter space and can reach 15% in some parameter
regions. We also show the Monte Carlo simulation results for the
$2j+\tau_{jet}+\not{p}_{T}$ signature from the $W^{\pm}$ and the $H^{\mp}$
decays including the NLO QCD effects, and find an observable signal at a
$5\sigma$ level in some parameter region of the minimal supergravity model.


title:
Multiple protostellar systems. II. A high resolution near-infrared
  imaging survey in nearby star-forming regions

abstract:
  (abridged) Our project endeavors to obtain a robust view of multiplicity
among embedded Class I and Flat Spectrum protostars in a wide array of nearby
molecular clouds to disentangle ``universal'' from cloud-dependent processes.
We have used near-infrared adaptive optics observations at the VLT through the
H, Ks and L' filters to search for tight companions to 45 Class I and Flat
Spectrum protostars located in 4 different molecular clouds (Taurus-Auriga,
Ophiuchus, Serpens and L1641 in Orion). We complemented these observations with
published high-resolution surveys of 13 additional objects in Taurus and
Ophiuchus. We found multiplicity rates of 32+/-6% and 47+/-8% over the 45-1400
AU and 14-1400 AU separation ranges, respectively. These rates are in excellent
agreement with those previously found among T Tauri stars in Taurus and
Ophiuchus, and represent an excess of a factor ~1.7 over the multiplicity rate
of solar-type field stars. We found no non-hierarchical triple systems, nor any
quadruple or higher-order systems. No significant cloud-to-cloud difference has
been found, except for the fact that all companions to low-mass Orion
protostars are found within 100 AU of their primaries whereas companions found
in other clouds span the whole range probed here. Based on this survey, we
conclude that core fragmentation always yields a high initial multiplicity
rate, even in giant molecular clouds such as the Orion cloud or in clustered
stellar populations as in Serpens, in contrast with predictions of numerical
simulations. The lower multiplicity rate observed in clustered Class II and
Class III populations can be accounted for by a universal set of properties for
young systems and subsequent ejections through close encounters with unrelated
cluster members.


title: Miraculous Cancellation and Pick's Theorem

abstract:
  We show that the Cappell-Shaneson version of Pick's theorem for simple
lattice polytopes is a consequence of a general relation between characteristic
numbers of virtual submanifolds dual to the characteristic classes of a stably
almost complex manifold. This relation is analogous to the miraculous
cancellation formula of Alvarez-Gaume and Witten, and is imposed by the action
of the Landweber-Novikov algebra in the complex cobordism ring of a point.


title:
Computing the Conditioning of the Components of a Linear Least Squares
  Solution

abstract:
  In this paper, we address the accuracy of the results for the overdetermined
full rank linear least squares problem. We recall theoretical results obtained
in Arioli, Baboulin and Gratton, SIMAX 29(2):413--433, 2007, on conditioning of
the least squares solution and the components of the solution when the matrix
perturbations are measured in Frobenius or spectral norms. Then we define
computable estimates for these condition numbers and we interpret them in terms
of statistical quantities. In particular, we show that, in the classical linear
statistical model, the ratio of the variance of one component of the solution
by the variance of the right-hand side is exactly the condition number of this
solution component when perturbations on the right-hand side are considered. We
also provide fragment codes using LAPACK routines to compute the
variance-covariance matrix and the least squares conditioning and we give the
corresponding computational cost. Finally we present a small historical
numerical example that was used by Laplace in Theorie Analytique des
Probabilites, 1820, for computing the mass of Jupiter and experiments from the
space industry with real physical data.


title: Radiative corrections to DVCS electron tensor

abstract:
  Radiative corrections in leading logarithmic approximation are calculated for
the differential cross section of $e^- \mu ^+$ radiative scattering. In
particular the interference term due to photon emission from electron and muon
blocks are calculated in helicity independent and dependent parts. The
calculation is applied to the kinematical conditions of existing DVCS data in
electron-proton collisions. Both helicity odd and helicity even differential
cross sections are considered.


title: Topological phase transition in complex networks

abstract:
  Preferential attachment is a central paradigm in the theory of complex
networks. In this contribution we consider various generalizations of
preferential attachment including for example node removal and edge rewiring.
We demonstrate that generalized preferential attachment networks can undergo a
topological phase transition. This transition separates networks having a
power-law tail degree distribution from those with an exponential tail. The
appearance of the phase transition is closely related to the breakdown of the
continuous variable description of the network dynamics.


title:
Isotopic liftings of Clifford algebras and applications in elementary
  particle mass matrices

abstract:
  Isotopic liftings of algebraic structures are investigated in the context of
Clifford algebras, where it is defined a new product involving an arbitrary,
but fixed, element of the Clifford algebra. This element acts as the unit with
respect to the introduced product, and is called isounit. We construct
isotopies in both associative and non-associative arbitrary algebras, and
examples of these constructions are exhibited using Clifford algebras, which
although associative, can generate the octonionic, non-associative, algebra.
The whole formalism is developed in a Clifford algebraic arena, giving also the
necessary pre-requisites to introduce isotopies of the exterior algebra. The
flavor hadronic symmetry of the six u,d,s,c,b,t quarks is shown to be exact,
when the generators of the isotopic Lie algebra su(6) are constructed, and the
unit of the isotopic Clifford algebra is shown to be a function of the six
quark masses. The limits constraining the parameters, that are entries of the
representation of the isounit in the isotopic group SU(6), are based on the
most recent limits imposed on quark masses.


title: Perturbative QCD in the Regge limit: Prospects at ILC

abstract:
  After recalling the theoretical and experimental status of QCD in the Regge
limit and the requirement of high energy scattering process of onium-onium type
for testing this limit, we show that the International Linear Collider would be
a major step in this field.


title: Congruence of multilinear forms

abstract:
  It is known that if A and B are two n-by-n complex matrices and (A,A^T) is
simultaneously equivalent to (B,B^T), then A is congruent to B. We extend this
statement to multilinear forms.


title:
Empirical transverse charge densities in the nucleon and the
  nucleon-to-$\Delta$ transition

abstract:
  Using only the current empirical information on the nucleon electromagnetic
form factors we map out the transverse charge density in proton and neutron as
viewed from a light front moving towards a transversely polarized nucleon.
These charge densities are characterized by a dipole pattern, in addition to
the monopole field corresponding with the unpolarized density. Furthermore, we
use the latest empirical information on the $N \to \Delta$ transition form
factors to map out the transition charge density which induces the $N \to
\Delta$ excitation. This transition charge density in a transversely polarized
$N$ and $\Delta$ contains both monopole, dipole and quadrupole patterns, the
latter corresponding with a deformation of the hadron's charge distribution.


title: Giant Magnetoresistance in Nanogranular Magnets

abstract:
  We study the giant magnetoresistance of nanogranular magnets in the presence
of an external magnetic field and finite temperature. We show that the
magnetization of arrays of nanogranular magnets has hysteretic behaviour at low
temperatures leading to a double peak in the magnetoresistance which coalesces
at high temperatures into a single peak. We numerically calculate the
magnetization of magnetic domains and the motion of domain walls in this system
using a combined mean-field approach and a model for an elastic membrane moving
in a random medium, respectively. From the obtained results, we calculate the
electric resistivity as a function of magnetic field and temperature. Our
findings show excellent agreement with various experimental data.


title:
Production of Millisecond Dips in Sco X-1 Count Rates by Dead Time
  Effects

abstract:
  Chang et al. (2006) reported millisecond duration dips in the X-ray intensity
of Sco X-1 and attributed them to occultations of the source by small
trans-Neptunian objects (TNOs). We have found multiple lines of evidence that
these dips are not astronomical in origin, but rather the result of high-energy
charged particle events in the RXTE PCA detectors. Our analysis of the RXTE
data indicates that at most 10% of the observed dips in Sco X-1 could be due to
occultations by TNOs, and, furthermore, we find no positive or supporting
evidence for any of them being due to TNOs. We therefore believe that it is a
mistake to conclude that any TNOs have been detected via occultation of Sco
X-1.


title:
Studying QCD factorizations in exclusive gamma* gamma* -> rho^0_L
  rho^0_L

abstract:
  The exclusive process e+ e- -> e+ e- rho^0_L rho^0_L allows to study various
dynamics and factorization properties of perturbative QCD. At moderate energy,
we demonstrate how collinear QCD factorization emerges, involving generalized
distribution amplitudes (GDA) and transition distribution amplitudes (TDA). At
higher energies, in the Regge limit of QCD, we show that it offers a promising
probe of the BFKL resummation effects to be studied at the International Linear
Collider (ILC).


title: Circumstellar Dust Created by Terrestrial Planet Formation in HD 113766

abstract:
  We present an analysis of the gas-poor circumstellar material in the HD
113766 binary system (F3/F5, 10 - 16 Myr), recently observed by the Spitzer
Space Telescope. For our study we have used the infrared mineralogical model
derived from observations of the Deep Impact experiment. We find the dust
dominated by warm, fine (~1 um) particles, abundant in Mg-rich olivine,
crystalline pyroxenes, amorphous silicates, Fe-rich sulfides, amorphous carbon,
and colder water-ice. The warm dust material mix is akin to an inner main belt
asteroid of S-type composition. The ~440 K effective temperature of the warm
dust implies that the bulk of the observed material is in a narrow belt ~1.8 AU
from the 4.4 L_solar central source, in the terrestrial planet-forming region
and habitable zone of the system (equivalent to 0.9 AU in the solar system).
The icy dust lies in 2 belts, located at 4-9 AU and at 30 - 80 AU. The lower
bound of warm dust mass in 0.1 - 20 um, dn/da ~ a^-3.5 particles is very large,
at least 3 x 10^20 kg, equivalent to a 320 km radius asteroid of 2.5 g cm^-3
density. Assuming 10m largest particles present, the lower bound of warm dust
mass is at least 0.5 M_Mars The dust around HD 113766A originates from
catastrophic disruption of terrestrial planet embryo(s) and subsequent grinding
of the fragments, or from collisions in a young, extremely dense asteroid belt
undergoing aggregation. The persistence of the strong IR excess over the last
two decades argues for a mechanism to provide replenishment of the
circumstellar material on yearly timescales.


title: Theory of stripe domains in magnetic shape memory alloys

abstract:
  The evolution of multivariant patterns in thin plates of magnetic shape
memory materials with an applied magnetic field was studied theoretically. A
geometrical domain-model is considered composed of straight stripe-like
martensite variants with constant internal magnetization (high anisotropy
limit) and magnetic domain wall orientation fixed by the twin boundaries.
Through integral transforms of the demagnetization energy, the micromagnetic
energy is cast into a form convenient for direct numerical evaluation and
analytical calculations. The equilibrium geometrical parameters of multivariant
patterns with straight and oblique twin boundaries have been derived as
functions of the applied field and the material parameters of a plate. It is
shown that the oblique multivariant states exist only in plates with
thicknesses L larger than a certain critical value L_0. In samples with L < L_0
a magnetic-field-driven transformation occurs directly between single variant
states.


title:
Deformed Oscillators with Two Double (Pairwise) Degeneracies of Energy
  Levels

abstract:
  A scheme is proposed which allows to obtain special $q$-oscillator models
whose characteristic feature consists in possessing two differing pairs of
degenerate energy levels. The method uses the model of two-parameter deformed
$q,p$-oscillators and proceeds via appropriately chosen particular relation
between $p$ and $q$. Different versions of quadratic relations $p=f(q)$ are
utilized for the case which implies two degenerate pairs $E_1=E_2$ and
$E_3=E_4$. On the other hand, using one fixed quadratic relation, we obtain
$p$-oscillators with other cases of two pairs of (pairwise) degenerate energy
levels.


title:
Syst\`emes interactifs sensibles aux \'emotions : architecture
  logicielle

abstract:
  We propose a software architecture for interactive systems which allows
integrating the user's emotion. Emotion can be involved in interaction at
several levels. In our application case - ballet dance - emotions is
explicitely manipulated by the interactive system to produce emotion-wise
output. Our architecture model to develop emotion-wise applications is based on
the PAC-Amodeus model. We add a branch to this model, divided into three
components: Data capture, analysis and cue extraction, and finally
interpretation of those cues. We show the different data flows between this
architecture's components depending on the entry point of the emotion branch
within the system. We then illustrate our model by describing our application
case: capturing a ballet dancer's movement to extract the emotions he expresses
and use these emotions to generate graphical content that is displayed on
stage.


title: Superintegrable anharmonic oscillators on N-dimensional curved spaces

abstract:
  The maximal superintegrability of the intrinsic harmonic oscillator potential
on N-dimensional spaces with constant curvature is revisited from the point of
view of sl(2)-Poisson coalgebra symmetry. It is shown how this algebraic
approach leads to a straightforward definition of a new large family of
quasi-maximally superintegrable perturbations of the intrinsic oscillator on
such spaces. Moreover, the generalization of this construction to those
N-dimensional spaces with non-constant curvature that are endowed with
sl(2)-coalgebra symmetry is presented. As the first examples of the latter
class of systems, both the oscillator potential on an N-dimensional Darboux
space as well as several families of its quasi-maximally superintegrable
anharmonic perturbations are explicitly constructed.


title:
Simulated synchrotron and Inverse Compton emission from Pulsar Wind
  Nebulae

abstract:
  We present a complete set of diagnostic tools aimed at reproducing synthetic
non-thermal (synchrotron and/or Inverse Compton, IC) emissivity, integrated
flux energy, polarization and spectral index simulated maps in comparison to
observations. The time dependent relativistic magnetohydrodynamic (RMHD)
equations are solved with a shock capturing code together with the evolution of
the maximum particles energy. Applications to Pulsar Wind Nebulae (PWNe) are
shown.


title:
The nested Chinese restaurant process and Bayesian nonparametric
  inference of topic hierarchies

abstract:
  We present the nested Chinese restaurant process (nCRP), a stochastic process
which assigns probability distributions to infinitely-deep,
infinitely-branching trees. We show how this stochastic process can be used as
a prior distribution in a Bayesian nonparametric model of document collections.
Specifically, we present an application to information retrieval in which
documents are modeled as paths down a random tree, and the preferential
attachment dynamics of the nCRP leads to clustering of documents according to
sharing of topics at multiple levels of abstraction. Given a corpus of
documents, a posterior inference algorithm finds an approximation to a
posterior distribution over trees, topics and allocations of words to levels of
the tree. We demonstrate this algorithm on collections of scientific abstracts
from several journals. This model exemplifies a recent trend in statistical
machine learning--the use of Bayesian nonparametric methods to infer
distributions on flexible data structures.


title: Isotope separation with the RICH detector of the AMS Experiment

abstract:
  The Alpha Magnetic Spectrometer (AMS), to be installed on the International
Space Station (ISS) in 2008, is a cosmic ray detector with several subsystems,
one of which is a proximity focusing Ring Imaging Cherenkov (RICH) detector.
This detector will be equipped with a dual radiator (aerogel+NaF), a lateral
conical mirror and a detection plane made of 680 photomultipliers and light
guides, enabling precise measurements of particle electric charge and velocity.
Combining velocity measurements with data on particle rigidity from the AMS
Tracker it is possible to obtain a measurement for particle mass, allowing the
separation of isotopes. A Monte Carlo simulation of the RICH detector, based on
realistic properties measured at ion beam tests, was performed to evaluate
isotope separation capabilities. Results for three elements -- H (Z=1), He
(Z=2) and Be (Z=4) -- are presented.


title: Emotion capture based on body postures and movements

abstract:
  In this paper we present a preliminary study for designing interactive
systems that are sensible to human emotions based on the body movements. To do
so, we first review the literature on the various approaches for defining and
characterizing human emotions. After justifying the adopted characterization
space for emotions, we then focus on the movement characteristics that must be
captured by the system for being able to recognize the human emotions.


title:
Formulas for Birkhoff-(Rota-Baxter) decompositions related to connected
  bialgebra

abstract:
  In recent years, The BPHZ algorithm for renormalization in quantum field
theory has been interpreted, after dimensional regularization, as the
Birkhoff-(Rota-Baxter) decomposition (BRB) of characters on the Hopf algebra of
Feynmann graphs, with values in a Rota-Baxter algebra. We give in this paper
formulas for the BRB decomposition in the group $\mathcal{C}(H, A)$ of
characters on a connected Hopf algebra $H$, with values in a Rota-Baxter
(commutative) algebra $A$. To do so we first define the stuffle (or
quasi-shuffle) Hopf algebra $A^{\tmop{st}}$ associated to an algebra $A$. We
prove then that for any connected Hopf algebra $H = k 1_H \oplus H'$, there
exists a canonical injective morphism from $H$ to $H'^{\tmop{st}}$. This
morphism induces an action of $\mathcal{C}(A^{\tmop{st}}, A)$ on
$\mathcal{C}(H, A)$ so that the BRB decomposition in $\mathcal{C}(H, A)$ is
determined by the action of a unique (universal) element of
$\mathcal{C}(A^{\tmop{st}}, A)$.


title: Decomposition of variance in terms of conditional means

abstract:
  We test against two different sets of data an apparently new approach to the
analysis of the variance of a numerical variable which depends on qualitative
characters. We suggest that this approach be used to complement other existing
techniques to study the interdependence of the variables involved. According to
our method the variance is expressed as a sum of orthogonal components,
obtained as differences of conditional means, with respect to the qualitative
characters. The resulting expression for the variance depends on the ordering
in which the characters are considered. We suggest an algorithm which leads to
an ordering which is deemed natural. The first set of data concerns the score
achieved by a population of students, on an entrance examination, based on a
multiple choice test with 30 questions. In this case the qualitative characters
are dyadic and correspond to correct or incorrect answer to each question. The
second set of data concerns the delay in obtaining the degree for a population
of graduates of Italian universities. The variance in this case is analyzed
with respect to a set of seven specific qualitative characters of the
population studied (gender, previous education, working condition, parent's
educational level, field of study, etc.)


title:
Monte Carlo Methods and Path-Generation techniques for Pricing
  Multi-asset Path-dependent Options

abstract:
  We consider the problem of pricing path-dependent options on a basket of
underlying assets using simulations. As an example we develop our studies using
Asian options. Asian options are derivative contracts in which the underlying
variable is the average price of given assets sampled over a period of time.
Due to this structure, Asian options display a lower volatility and are
therefore cheaper than their standard European counterparts. This paper is a
survey of some recent enhancements to improve efficiency when pricing Asian
options by Monte Carlo simulation in the Black-Scholes model. We analyze the
dynamics with constant and time-dependent volatilities of the underlying asset
returns. We present a comparison between the precision of the standard Monte
Carlo method (MC) and the stratified Latin Hypercube Sampling (LHS). In
particular, we discuss the use of low-discrepancy sequences, also known as
Quasi-Monte Carlo method (QMC), and a randomized version of these sequences,
known as Randomized Quasi Monte Carlo (RQMC). The latter has proven to be a
useful variance reduction technique for both problems of up to 20 dimensions
and for very high dimensions. Moreover, we present and test a new path
generation approach based on a Kronecker product approximation (KPA) in the
case of time-dependent volatilities. KPA proves to be a fast generation
technique and reduces the computational cost of the simulation procedure.


title:
Embedded two-photon polymerized features with near-perfect lattice
  registration within self-organized photonic crystals and their optical
  properties

abstract:
  Two-photon polymerization has been demonstrated as an effective technique to
define embedded defects in three-dimensional photonic crystals. In this work we
demonstrate the ability to precisely position embedded defects with respect to
the lattice of three-dimensional photonic crystals by imaging the structure
concurrently with two-photon writing. Defects are written with near-perfect
lattice registration and at specifically defined depths within the crystal. The
importance of precise defect position is demonstrated by investigating the
optical properties of embedded planar cavities written in a photonic crystal.
The experimental data is compared to spectra calculated using the Scalar Wave
Approximation (SWA) which further demonstrates the importance of defect
placement.


title:
A regularization algorithm for matrices of bilinear and sesquilinear
  forms

abstract:
  We give an algorithm that uses only unitary transformations and for each
square complex matrix constructs a *congruent matrix that is a direct sum of a
nonsingular matrix and singular Jordan blocks.


title: Search for supersymmetric charged Higgs bosons at the TeVatron

abstract:
  The data collected at the TeVatron RunIIa have been used to look for
supersymmetric charged Higgs boson and Left-Right suspersymmetric doubly
charged Higgs boson. No signal of such bosons has been found and this note
reports on the current analyses and their observed excluded domains in models
parameter space.


title: 2D Cooling of Magnetized Neutron Stars

abstract:
  Context: Many thermally emitting isolated neutron stars have magnetic fields
larger than 10^13 G. A realistic cooling model that includes the presence of
high magnetic fields should be reconsidered. Aims: We investigate the effects
of anisotropic temperature distribution and Joule heating on the cooling of
magnetized neutron stars. Methods: The 2D heat transfer equation with
anisotropic thermal conductivity tensor and including all relevant neutrino
emission processes is solved for realistic models of the neutron star interior
and crust. Results: The presence of the magnetic field affects significantly
the thermal surface distribution and the cooling history during both, the early
neutrino cooling era and the late photon cooling era. Conclusions: There is a
large effect of the Joule heating on the thermal evolution of strongly
magnetized neutron stars. Both magnetic fields and Joule heating play a key
role in keeping magnetars warm for a long time. Moreover, this effect is
important for intermediate field neutron stars and should be considered in
radio-quiet isolated neutron stars or high magnetic field radio-pulsars.


title: Secular effects on inflation from one-loop quantum gravity

abstract:
  In this paper we revisit and extend a previous analysis where the possible
relevance of quantum gravity effects in a cosmological setup was studied. The
object of interest are non-local (logarithmic) terms generated in the effective
action of gravity due to the exchange in loops of massless modes (such as
photons or the gravitons themselves). We correct one mistake existing in the
previous work and discuss the issue in a more general setting in different
cosmological scenarios. We obtain the one-loop quantum-corrected evolution
equations for the cosmological scale factor up to a given order in a derivative
expansion in two particular cases: a matter dominated universe with vanishing
cosmological constant, and in a de Sitter universe. We show that the quantum
corrections, albeit tiny, may have a secular effect that eventually modifies
the expansion rate. For a de Sitter universe they tend to slow down the rate of
the expansion, while the effect seems to have the opposite sign in a matter
dominated universe. To partly understand these effects we provide a
complementary newtonian analysis.


title: Lectures on two-dimensional critical percolation

abstract:
  These are the notes corresponding to the course given at the IAS-Park City
graduate summer school in July 2007.


title:
Dynamic Programming Optimization over Random Data: the Scaling Exponent
  for Near-optimal Solutions

abstract:
  A very simple example of an algorithmic problem solvable by dynamic
programming is to maximize, over sets A in {1,2,...,n}, the objective function
|A| - \sum_i \xi_i 1(i \in A,i+1 \in A) for given \xi_i > 0. This problem, with
random (\xi_i), provides a test example for studying the relationship between
optimal and near-optimal solutions of combinatorial optimization problems. We
show that, amongst solutions differing from the optimal solution in a small
proportion \delta of places, we can find near-optimal solutions whose objective
function value differs from the optimum by a factor of order \delta^2 but not
smaller order. We conjecture this relationship holds widely in the context of
dynamic programming over random data, and Monte Carlo simulations for the
Kauffman-Levin NK model are consistent with the conjecture. This work is a
technical contribution to a broad program initiated in Aldous-Percus (2003) of
relating such scaling exponents to the algorithmic difficulty of optimization
problems.


title: Graphene with geometrically induced vorticity

abstract:
  At half filling, the electronic structure of graphene can be modelled by a
pair of free two-dimensional Dirac fermions. We explicitly demonstrate that in
the presence of a geometrically induced gauge field, an everywhere-real Kekule
modulation of the hopping matrix elements can correspond to a non-real Higgs
field with non-trivial vorticity. This provides a natural setting for
fractionally charged vortices with localized zero modes. For fullerene-like
molecules we employ the index theorem to demonstrate the existence of six
low-lying states that do not depend strongly on the Kekule-induced mass gap.

categories: cond-mat.mes-hall cond-mat.str-el hep-ph hep-th quant-ph


title:
Assistance orale \`a la recherche visuelle - \'etude exp\'erimentale de
  l'apport d'indications spatiales \`a la d\'etection de cibles

abstract:
  This paper describes an experimental study that aims at assessing the actual
contribution of voice system messages to visual search efficiency and comfort.
Messages which include spatial information on the target location are meant to
support search for familiar targets in collections of photographs (30 per
display). 24 participants carried out 240 visual search tasks in two conditions
differing from each other in initial target presentation only. The isolated
target was presented either simultaneously with an oral message (multimodal
presentation, MP), or without any message (visual presentation, VP). Averaged
target selection times were thrice longer and errors almost twice more frequent
in the VP condition than in the MP condition. In addition, the contribution of
spatial messages to visual search rapidity and accuracy was influenced by
display layout and task difficulty. Most results are statistically significant.
Besides, subjective judgments indicate that oral messages were well accepted.


title: A new technique for proving uniqueness for martingale problems

abstract:
  A new technique for proving uniqueness of martingale problems is introduced.
The method is illustrated in the context of elliptic diffusions in $R^d$.


title: Tailoring of phononic band structures in colloidal crystals

abstract:
  We report an experimental study of the elastic properties of a
two-dimensional (2D) colloidal crystal subjected to light-induced substrate
potentials. In agreement with recent theoretical predictions [H.H. von
Gruenberg and J. Baumgartl, Phys. Rev. E 75, 051406 (2007)] the phonon band
structure of such systems can be tuned depending on the symmetry and depth of
the substrate potential. Calculations with binary crystals suggest that
phononic band engineering can be also performed by variations of the pair
potential and thus opens novel perspectives for the fabrication of phononic
crystals with band gaps tunable by external fields.


title: Rigid systems of second-order linear differential equations

abstract:
  We say that a system of differential equations
d^2x(t)/dt^2=Adx(t)/dt+Bx(t)+Cu(t), in which A and B are m-by-m complex
matrices and C is an m-by-n complex matrix, is rigid if it can be reduced by
substitutions x(t)=Sy(t), u(t)=Udy(t)/dt+Vy(t)+Pv(t) with nonsingular S and P
to each system obtained from it by a small enough perturbation of its matrices
A,B,C. We prove that there exists a rigid system if and only if
m<n(1+square_root{5})/2, and describe all rigid systems.


title:
Highly Excited Mesons, Linear Regge Trajectories and the Pattern of the
  Chiral Symmetry Realization

abstract:
  The chiral symmetry of QCD shows up in the linear Weyl--Wigner mode at short
Euclidean distances or at high temperatures. On the other hand, low-lying
hadronic states exhibit the nonlinear Nambu--Goldstone mode. An interesting
question was raised as to whether the linear realization of the chiral symmetry
is asymptotically restored for highly excited states. We address it in a number
of ways. On the phenomenological side we argue that to the extent the meson
Regge trajectories are observed to be linear and equidistant, the Weyl--Wigner
mode is not realized.
  This picture is supported by quasiclassical arguments implying that the quark
spin interactions in high excitations are weak, the trajectories are linear,
and there is no chiral symmetry restoration. Then we use the string/gauge
duality. In the top-down Sakai--Sugimoto construction the nonlinear realization
of the chiral symmetry is built in. In the bottom-up AdS/QCD construction by
Erlich et al., and Karch et al. the situation is more ambiguous. However, in
this approach linearity and equidistance of the Regge trajectories can be
naturally implemented, with the chiral symmetry in the Nambu--Goldstone mode.
  Asymptotic chiral symmetry restoration might be possible if a nonlinearity
(convergence) of the Regge trajectories in an "intermediate window" of $n,J$,
beyond the explored domain, takes place. This would signal the failure of the
quasiclassical picture.


title:
Evidence of random magnetic anisotropy in ferrihydrite nanoparticles
  based on analysis of statistical distributions

abstract:
  We show that the magnetic anisotropy energy of antiferromagnetic ferrihydrite
depends on the square root of the nanoparticles volume, using a method based on
the analysis of statistical distributions. The size distribution was obtained
by transmission electron microscopy, and the anisotropy energy distributions
were obtained from ac magnetic susceptibility and magnetic relaxation. The
square root dependence corresponds to random local anisotropy, whose average is
given by its variance, and can be understood in terms of the recently proposed
single phase homogeneous structure of ferrihydrite.


title: Secrecy Capacity of the Wiretap Channel with Noisy Feedback

abstract:
  In this work, the role of noisy feedback in enhancing the secrecy capacity of
the wiretap channel is investigated. A model is considered in which the
feed-forward and feedback signals share the same noisy channel. More
specifically, a discrete memoryless modulo-additive channel with a full-duplex
destination node is considered first, and it is shown that a judicious use of
feedback increases the perfect secrecy capacity to the capacity of the
source-destination channel in the absence of the wiretapper. In the
achievability scheme, the feedback signal corresponds to a private key, known
only to the destination. Then a half-duplex system is considered, for which a
novel feedback technique that always achieves a positive perfect secrecy rate
(even when the source-wiretapper channel is less noisy than the
source-destination channel) is proposed. These results hinge on the
modulo-additive property of the channel, which is exploited by the destination
to perform encryption over the channel without revealing its key to the source.


title: Abundance Patterns in Stars in the Bulge and Galactic Center

abstract:
  We discuss oxygen and iron abundance patterns in K and M red-giant members of
the Galactic bulge and in the young and massive M-type stars inhabiting the
very center of the Milky Way. The abundance results from the different bulge
studies in the literature, both in the optical and the infrared, indicate that
the [O/Fe]-[Fe/H] relation in the bulge does not follow the disk relation, with
[O/Fe] values falling above those of the disk. Based on these elevated values
of [O/Fe] extending to large Fe abundances, it is suggested that the bulge
underwent a rapid chemical enrichment with perhaps a top-heavy initial mass
function. The Galactic Center stars reveal a nearly uniform and slightly
elevated (relative to solar) iron abundance for a studied sample which is
composed of 10 red giants and supergiants. Perhaps of more significance is the
fact that the young Galactic Center M-type stars show abundance patterns that
are reminiscent of those observed for the bulge population and contain enhanced
abundance ratios of alpha-elements relative to either the Sun or Milky Way disk
at near-solar metallicities.


title: The case for an aggressive program of dark energy probes

abstract:
  The observed cosmic acceleration presents the physics and cosmology
communities with amazing opportunities to make exciting, probably even radical
advances in these fields. This topic is highly data driven and many of our
opportunities depend on us undertaking an ambitious observational program. Here
I outline the case for such a program based on both the exciting science
related to the cosmic acceleration and the impressive impact that a strong
observational program would have. Along the way, I challenge a number of
arguments that skeptics use to question the value of a strong observational
commitment to this field.


title: Peak points for pseudoconvex domains: a survey

abstract:
  This paper surveys results concerning peak points for pseudoconvex domains.
It includes results of Laszlo that have not been published elsewhere.


title:
Lattice Results for Vector Meson Couplings and Parton Distribution
  Amplitudes

abstract:
  We present results for the couplings of light vector mesons to vector and
tensor currents and on the low moments of the light-cone distribution
amplitudes of the pion and kaon. The calculations are performed on the RBC and
UKQCD collaborations' ensembles generated with the Iwasaki gauge action and
with 2+1 flavours of domain wall fermions. The (preliminary) results for the
ratios of the couplings of the vector meson to the vector and tensor currents
(f_V and f^T_V respectively) in the MSbar scheme at 2GeV are:
f_\rho^T/f_\rho=0.681(20); f_{K^\ast}^T/f_{K^\ast}=0.712(11) and
f_\phi^T/f_\phi=0.751(9). For the first moment of the kaon's distribution
amplitude we find (in the same scheme and at the same scale) <xi>_K=0.029(2)
and for the second moment <xi^2>_\pi=0.28(3) and <xi^2>_K=0.27(2).


title:
Subadditivity of the entropy and its relation to Brascamp-Lieb type
  inequalities

abstract:
  We prove a general duality result showing that a Brascamp--Lieb type
inequality is equivalent to an inequality expressing subadditivity of the
entropy, with a complete correspondence of best constants and cases of
equality. This open a new approach to the proof of Brascamp--Lieb type
inequalities, via subadditivity of the entropy. We illustrate the utility of
this approach by proving a general inequality expressing the subadditivity
property of the entropy on $\R^n$, and fully determining the cases of equality.
As a consequence of the duality mentioned above, we obtain a simple new proof
of the classical Brascamp--Lieb inequality, and also a fully explicit
determination of all of the cases of equality. We also deduce several other
consequences of the general subadditivity inequality, including a
generalization of Hadamard's inequality for determinants. Finally, we also
prove a second duality theorem relating superadditivity of the Fisher
information and a sharp convolution type inequality for the fundamental
eigenvalues of Schr\"odinger operators. Though we focus mainly on the case of
random variables in $\R^n$ in this paper, we discuss extensions to other
settings as well.


title: Spreadsheets in Clinical Medicine

abstract:
  There is overwhelming evidence that the continued and widespread use of
untested spreadsheets in business gives rise to regular, significant and
unexpected financial losses. Whilst this is worrying, it is perhaps a
relatively minor concern compared with the risks arising from the use of poorly
constructed and/or untested spreadsheets in medicine, a practice that is
already occurring. This article is intended as a warning that the use of poorly
constructed and/or untested spreadsheets in clinical medicine cannot be
tolerated. It supports this warning by reporting on potentially serious
weaknesses found while testing a limited number of publicly available clinical
spreadsheets.


title:
Stability of a Nonlinear Axially Moving String With the Kelvin-Voigt
  Damping

abstract:
  In this paper, a nonlinear axially moving string with the Kelvin-Voigt
damping is considered. It is proved that the string is stable, i.e., its
transversal displacement converges to zero when the axial speed of the string
is less than a certain critical value. The proof is established by showing that
a Lyapunov function corresponding to the string decays to zero exponentially.
It is also shown that the string displacement is bounded when a bounded
distributed force is applied to it transversally. Furthermore, a few open
problems regarding the stability and stabilization of strings with the
Kelvin-Voigt damping are stated.


title: Mirror Mediation

abstract:
  I show that the effective action of string compactifications has a structure
that can naturally solve the supersymmetric flavour and CP problems. At leading
order in the g_s and \alpha' expansions, the hidden sector factorises. The
moduli space splits into two mirror parts that depend on Kahler and complex
structure moduli. Holomorphy implies the flavour structure of the Yukawa
couplings arises in only one part. In type IIA string theory flavour arises
through the Kahler moduli sector and in type IIB flavour arises through the
complex structure moduli sector. This factorisation gives a simple solution to
the supersymmetric flavour and CP problems: flavour physics is generated in one
sector while supersymmetry is broken in the mirror sector. This mechanism does
not require the presence of gauge, gaugino or anomaly mediation and is
explicitly realised by phenomenological models of IIB flux compactifications.


title:
A luminosity constraint on the origin of unidentified high energy
  sources

abstract:
  The identification of point sources poses a great challenge for the high
energy community. We present a new approach to evaluate the likelihood of a set
of sources being a Galactic population based on the simple assumption that
galaxies similar to the Milky Way host comparable populations of gamma-ray
emitters. We propose a luminosity constraint on Galactic source populations
which complements existing approaches by constraining the abundance and spatial
distribution of any objects of Galactic origin, rather than focusing on the
properties of a specific candidate emitter. We use M31 as a proxy for the Milky
Way, and demonstrate this technique by applying it to the unidentified EGRET
sources. We find that it is highly improbable that the majority of the
unidentified EGRET sources are members of a Galactic halo population (e.g.,
dark matter subhalos), but that current observations do not provide any
constraints on all of these sources being Galactic objects if they reside
entirely in the disk and bulge. Applying this method to upcoming observations
by the Fermi Gamma-ray Space Telescope has the potential to exclude association
of an even larger number of unidentified sources with any Galactic source
class.


title: Evidence of Cosmic Evolution of the Stellar Initial Mass Function

abstract:
  Theoretical arguments and indirect observational evidence suggest that the
stellar initial mass function (IMF) may evolve with time, such that it is more
weighted toward high mass stars at higher redshift. Here we test this idea by
comparing the rate of luminosity evolution of massive early-type galaxies in
clusters at 0.02<z<0.83 to the rate of their color evolution. A combined fit to
the rest-frame U-V color evolution and the previously measured evolution of the
M/L_B ratio gives x~-0.3 for the logarithmic slope of the IMF in the region
around 1 Solar mass, flatter than the present-day value in the Milky Way disk
of x=1.3. The best-fitting luminosity-weighted formation redshift of the stars
in massive cluster galaxies is ~3.7, and a possible interpretation is that the
characteristic mass m_c had a value of ~2 Solar masses at z~4 (compared to
m_c~0.1 Solar masses today), in qualitative agreement with models in which the
characteristic mass is a function of the Jeans mass in molecular clouds. Such a
``bottom-light'' IMF for massive cluster galaxies has significant implications
for the interpretation of measurements of galaxy formation and evolution.
Applying a simple form of IMF evolution to literature data, we find that the
volume-averaged star formation rate at high redshift may have been
overestimated (by a factor of 3-4 at z>4), and the cosmic star formation
history may have a fairly well-defined peak at z~1.5. The M/L_V ratios of
galaxies are less affected than their star formation rates, and future data on
the stellar mass density at z>3 will provide further constraints on IMF
evolution. The formal errors likely underestimate the uncertainties, and
confirmation of thes results requires a larger sample of clusters and the
inclusion of redder rest-frame colors in the analysis.


title:
Spin Meissner Effect in Superconductors and the Origin of the Meissner
  Effect

abstract:
  We propose a dynamical explanation of the Meissner effect in superconductors
and predict the existence of a spin Meissner effect: that a macroscopic spin
current flows within a London penetration depth $\lambda_L$ of the surface of
superconductors in the absence of applied external fields, with carrier density
= the superfluid density and carrier speed $v=\hbar/(4m_e\lambda_L$)
($m_e=$bare electron mass). The two members of a Cooper pair circulate in
orbits of radius $2\lambda_L$ in opposite direction and the spin current in a
Cooper pair has orbital angular momentum $\hbar$. Our description also provides
a 'geometric' interpretation of the difference between type I and type II
superconductors.


title: Morphology of graphene thin film growth on SiC(0001)

abstract:
  Epitaxial films of graphene on SiC(0001) are interesting from a basic physics
as well as applications-oriented point of view. Here we study the emerging
morphology of in-vacuo prepared graphene films using low energy electron
microscopy (LEEM) and angle-resolved photoemission (ARPES). We obtain an
identification of single and bilayer of graphene film by comparing the
characteristic features in electron reflectivity spectra in LEEM to the PI-band
structure as revealed by ARPES. We demonstrate that LEEM serves as a tool to
accurately determine the local extent of graphene layers as well as the layer
thickness.


title: The Total Merger Rate of Compact Object Binaries In The Local Universe

abstract:
  Using a population synthesis approach, we compute the total merger rate in
the local Universe for double neutron stars, double black holes, and black hole
-- neutron star binaries. These compact binaries are the prime source
candidates for gravitational-wave detection by LIGO and VIRGO. We account for
mergers originating from field populations and from dense stellar clusters. For
both populations we use the same treatment of stellar evolution. Our results
indicate that the merger rates of double neutron stars and black hole --
neutron star binaries are strongly dominated by field populations, while
merging black hole binaries are formed much more effectively in dense stellar
clusters. The overall merger rate of double compact objects depends sensitively
on the (largely unknown) initial mass fraction contained in dense clusters
f_cl. For f_cl < 0.0001, the Advanced LIGO detection rate will be dominated by
field populations of double neutron star mergers, with a small but significant
number of detections ~20 yr^-1. However for a higher mass fraction in clusters,
f_cl > 0.001, the detection rate will be dominated by numerous mergers of
double black holes originating from dense clusters, and it will be considerably
higher, ~25 - 300 yr^-1. In addition, we show that, once mergers of double
black holes are detected, it is easy to differentiate between systems formed in
the field and in dense clusters, since the chirp mass distributions are
strikingly different. Finally, we point out that there may exist a population
of merging black hole binaries in intergalactic space.


title: Close encounters of three black holes

abstract:
  We present the first fully relativistic longterm numerical evolutions of
three equal-mass black holes in a system consisting of a third black hole in a
close orbit about a black-hole binary. We find that these
close-three-black-hole systems have very different merger dynamics from
black-hole binaries. In particular, we see complex trajectories, a
redistribution of energy that can impart substantial kicks to one of the holes,
distinctive waveforms, and suppression of the emitted gravitational radiation.
We evolve two such configurations and find very different behaviors. In one
configuration the binary is quickly disrupted and the individual holes follow
complicated trajectories and merge with the third hole in rapid succession,
while in the other, the binary completes a half-orbit before the initial merger
of one of the members with the third black hole, and the resulting
two-black-hole system forms a highly elliptical, well separated binary that
shows no significant inspiral for (at least) the first t~1000M of evolution.


title:
Continuum and Symmetry-Conserving Effects in Drip-line Nuclei Using
  Finite-range Forces

abstract:
  We report the first calculations of nuclear properties near the drip-lines
using the spherical Hartree-Fock-Bogoliubov mean-field theory with a
finite-range force supplemented by continuum and particle number projection
effects. Calculations were carried out in a basis made of the eigenstates of a
Woods-Saxon potential computed in a box, thereby garanteeing that continuum
effects were properly taken into account. Projection of the self-consistent
solutions on good particle number was carried out after variation, and an
approximation of the variation after projection result was used. We give the
position of the drip-lines and examine neutron densities in neutron-rich
nuclei. We discuss the sensitivity of nuclear observables upon continuum and
particle-number restoration effects.


title: Biomarkers set in context

abstract:
  In a famous paper, Sagan et al.(1993) analyzed a spectrum of the Earth taken
by the Galileo probe, searching for signatures of life. They concluded that the
large amount of O2 and the simultaneous presence of CH4 traces are strongly
suggestive of biology. The detection of a widespread red-absorbing pigment with
no likely mineral origin supports the hypothesis of biophotosynthesis. The
search for signs of life on possibly very different planets implies that we
need to gather as much information as possible in order to understand how the
observed atmosphere physically and chemically works.
  The Earth-Sun intensity ratio is about 10^{-7} in the thermal infrared (10
micrometer), and about 10^{-10} in the visible (0.5 micrometer). The
interferometric systems suggested for Darwin and the Terrestrial Planet Finder
Interferometer (TPF-I) mission operates in the mid-IR (5 - 20 micrometer), the
coronagraph suggested for Terrestrial Planet Finder Coronagraph (TPF-C) in the
visible (0.5 - 1 micrometer). For the former it is thus the thermal emission
emanating from the planet that is detected and analyzed while for the later the
reflected stellar flux is measured. The spectrum of the planet can contain
signatures of atmospheric species that are important for habitability, like CO2
and H2O, or result from biological activity (O2, O3, CH4, and N2O). Both
spectral regions contain atmospheric bio-indicators. The presence or absence of
these spectral features will indicate similarities or differences with the
atmospheres of terrestrial planets and are discussed in detail and set into
context with the physical characteristics of a planet in this chapter.


title:
On the most compact regular lattice in large dimensions: A statistical
  mechanical approach

abstract:
  In this paper I will approach the computation of the maximum density of
regular lattices in large dimensions using a statistical mechanics approach.
The starting point will be some theorems of Roger, which are virtually unknown
in the community of physicists. Using his approach one can see that there are
many similarities (and differences) with the problem of computing the entropy
of a liquid of perfect spheres. The relation between the two problems is
investigated in details. Some conjectures are presented, that need further
investigation in order to check their consistency.


title: Fluctuation-driven directed transport in the presence of Levy flights

abstract:
  Numerical evidence of directed transport driven by symmetric Levy noise in
time-independent ratchet potentials in the absence of an external tilting force
is presented. The results are based on the numerical solution of the fractional
Fokker-Planck equation in a periodic potential and the corresponding Langevin
equation with Levy noise. The Levy noise drives the system out of thermodynamic
equilibrium and an up-hill net current is generated. For small values of the
noise intensity there is an optimal value of the Levy noise index yielding the
maximum current. The direction and magnitude of the current can be manipulated
by changing the Levy noise asymmetry and the potential asymmetry.


title:
Magnetic field induced effects in the high source-drain bias current of
  weakly coupled vertical quantum dot molecules

abstract:
  We report on the basic properties of recently observed magnetic field
resonance, induced time dependent oscillation, and hysteresis effects in the
current flowing through two weakly coupled vertical quantum dots at high
source-drain bias (up to a few tens of mV). These effects bare some similarity
to those reported in the N=2 spin-blockade regime, usually for weak in-plane
magnetic field, of quantum dot molecules and attributed to hyperfine coupling,
except here the measurements are conducted outside of the spin-blockade regime
and the out-of-plane magnetic field is up to ~6 T.


title: The Quantum Formalism and the GRW Formalism

abstract:
  The Ghirardi-Rimini-Weber (GRW) theory of spontaneous wave function collapse
is known to provide a quantum theory without observers, in fact two different
ones by using either the matter density ontology (GRWm) or the flash ontology
(GRWf). Both theories are known to make predictions different from those of
quantum mechanics, but the difference is so small that no decisive experiment
can as yet be performed. While some testable deviations from quantum mechanics
have long been known, we provide here something that has until now been
missing: a formalism that succinctly summarizes the empirical predictions of
GRWm and GRWf. We call it the GRW formalism. Its structure is similar to that
of the quantum formalism but involves different operators. In other words, we
establish the validity of a general algorithm for directly computing the
testable predictions of GRWm and GRWf. We further show that some well-defined
quantities cannot be measured in a GRWm or GRWf world.


title: Ordered spanning sets for quasimodules for Mobius vertex algebras

abstract:
  Quasimodules for vertex algebras are generalizations of modules for vertex
algebras. These new objects arise from a generalization of locality for fields.
Quasimodules tie together module theory and twisted module theory, and both
twisted and untwisted modules feature Poincare-Birkhoff-Witt-like spanning
sets. This paper generalizes these spanning set results to quasimodules for
certain Mobius vertex algebras. In particular this paper presents two spanning
sets, one featuring a difference-zero ordering restriction on modes and another
featuring a difference-one condition.


title: Ordered spanning sets for vertex operator algebras and their modules

abstract:
  Moonshine relates three fundamental mathematical objects: the Monster
sporadic simple group, the modular function j, and the moonshine module vertex
operator algebra. Examining the relationship between modular functions and the
representation theory of vertex operator algebras reveals rich structure. In
particular, C2-cofiniteness (also called Zhu's finiteness condition) implies
the existence of finite generating sets and Poincare-Birkhoff-Witt-like
spanning sets for vertex operator algebras and their modules. These spanning
sets feature desirable ordering restrictions, e.g., a difference-one condition.


title:
GaAs:Mn nanowires grown by molecular beam epitaxy of (Ga,Mn)As at MnAs
  segregation conditions

abstract:
  GaAs:Mn nanowires were obtained on GaAs(001) and GaAs(111)B substrates by
molecular beam epitaxial growth of (Ga,Mn)As at conditions leading to MnAs
phase separation. Their density is proportional to the density of catalyzing
MnAs nanoislands, which can be controlled by the Mn flux and/or the substrate
temperature. Being rooted in the ferromagnetic semiconductor (Ga,Mn)As, the
nanowires combine one-dimensional properties with the magnetic properties of
(Ga,Mn)As and provide natural, self assembled structures for nanospintronics.


title: Some Properties of Hypergeometric Series Associated with Mirror Symmetry

abstract:
  We show that certain hypergeometric series used to formulate mirror symmetry
for Calabi-Yau hypersurfaces, in string theory and algebraic geometry, satisfy
a number of interesting properties. Many of these properties are used in
separate papers to verify the BCOV prediction for the genus one Gromov-Witten
invariants of a quintic threefold and more generally to compute the genus one
Gromov-Witten invariants of any Calabi-Yau projective hypersurface.


title:
APOLLO: the Apache Point Observatory Lunar Laser-ranging Operation:
  Instrument Description and First Detections

abstract:
  A next-generation lunar laser ranging apparatus using the 3.5 m telescope at
the Apache Point Observatory in southern New Mexico has begun science
operation. APOLLO (the Apache Point Observatory Lunar Laser-ranging Operation)
has achieved one-millimeter range precision to the moon which should lead to
approximately one-order-of-magnitude improvements in the precision of several
tests of fundamental properties of gravity. We briefly motivate the scientific
goals, and then give a detailed discussion of the APOLLO instrumentation.


title: Gap excitations in a four-leg Heisenberg spin tube antiferromagnet

abstract:
  Inelastic neutron scattering is used to investigate magnetic excitations in
the quasi-one-dimensional quantum spin-liquid system Cu2Cl4 D8C4SO2. Contrary
to previously conjectured models that relied on bond-alternating nearest
neighbor interactions in the spin chains, the dominant interactions are
actually next-nearest-neighbor in-chain antiferromagnetic couplings. The
appropriate Heisenberg Hamiltonian is equivalent to that of a S = 1/2 4-leg
spin-tube with almost perfect one dimensionality and no bond alternation. A
partial geometric frustration of rung interactions induces a small
incommensurability of short-range spin correlations.


title:
Prediction and verification of indirect interactions in densely
  interconnected regulatory networks

abstract:
  We develop a matrix-based approach to predict and verify indirect
interactions in gene and protein regulatory networks. It is based on the
approximate transitivity of indirect regulations (e.g. A regulates B and B
regulates C often implies that A regulates C) and optimally takes into account
the length of a cascade and signs of intermediate interactions. Our method is
at its most powerful when applied to large and densely interconnected networks.
It successfully predicts both the yet unknown indirect regulations, as well as
the sign (activation or repression) of already known ones. The reliability of
sign predictions was calibrated using the gold-standard sets of positive and
negative interactions. We fine-tuned the parameters of our algorithm by
maximizing the area under the Receiver Operating Characteristic (ROC) curve. We
then applied the optimized algorithm to large literature-derived networks of
all direct and indirect regulatory interactions in several model organisms
(Homo sapiens, Saccharomyces cerevisiae, Arabidopsis thaliana and Drosophila
melanogaster).


title:
A Galaxy in Transition: Structure, Globular Clusters, and Distance of
  the Star-Forming S0 Galaxy NGC 1533 in Dorado

abstract:
  We use two-band imaging data from the Advanced Camera for Surveys on board
the Hubble Space Telescope for a detailed study of NGC1533, an SB0 galaxy in
the Dorado group surrounded by a ring of HI. NGC1533 appears to be completing a
transition from late to early type: it is red, but not quite dead. Faint spiral
structure becomes visible following galaxy subtraction, and luminous blue stars
can be seen in isolated areas of the disk. Dust is visible in the color map in
the region around the bar, and there is a linear color gradient throughout the
disk. We determine an accurate distance from the surface brightness
fluctuations (SBF) method, finding m-M = 31.44\pm0.12 mag, or d = 19.4\pm1.1
Mpc. We then study the globular cluster (GC) colors, sizes, and luminosity
function (GCLF). Estimates of the distance from the median of the GC half-light
radii and from the peak of the GCLF both agree well with the SBF distance. The
GC specific frequency is S_N=1.3\pm0.2, typical for an early-type disk galaxy.
The color distribution is bimodal, as commonly observed for bright galaxies.
There is a suggestion of the redder GCs having smaller sizes, but the trend is
not significant. The sizes do increase significantly with galactocentric
radius, in a manner more similar to the Milky Way GC system than to those in
Virgo. This difference may be an effect of the steeper density gradients in
loose groups as compared to galaxy clusters. Additional studies of early-type
galaxies in low density regions can help determine if this is indeed a general
environmental trend.


title: Stable and Metastable Vacua in SQCD

abstract:
  We study deformations of N=1 supersymmetric QCD that exhibit a rich landscape
of supersymmetric and non-supersymmetric vacua.


title: Revealing anyonic features in a toric code quantum simulation

abstract:
  Anyons are quasiparticles in two-dimensional systems that show statistical
properties very distinct from those of bosons or fermions. While their isolated
observation has not yet been achieved, here we perform a quantum simulation of
anyons on the toric code model. By encoding the model in the multi-partite
entangled state of polarized photons, we are able to demonstrate various
manipulations of anyonic states and, in particular, their characteristic
fractional statistics.

categories: quant-ph cond-mat.mes-hall hep-th physics.optics


title:
Gapped itinerant spin excitations account for missing entropy in the
  hidden order state of URu$_2$Si$_2$

abstract:
  One of the primary goals of modern condensed matter physics is to elucidate
the nature of the ground state in various electronic systems. Many correlated
electron materials, such as high temperature superconductors, geometrically
frustrated oxides, and low-dimensional magnets are still the objects of
fruitful study because of the unique properties which arise due to poorly
understood many-body effects. Heavy fermion metals - materials which have high
effective electron masses due to these effects - represent a class of materials
with exotic properties, such as unusual magnetism, unconventional
superconductivity, and "hidden order" parameters. The heavy fermion
superconductor URu2Si2 has held the attention of physicists for the last two
decades due to the presence of a "hidden order" phase below 17.5 K. Neutron
scattering measurements indicate that the ordered moment is 0.03 $\mu_{B}$,
much too small to account for the large heat capacity anomaly at 17.5 K. We
present recent neutron scattering experiments which unveil a new piece of this
puzzle - the spin excitation spectrum above 17.5 K exhibits well-correlated,
itinerant-like spin excitations up to at least 10 meV emanating from
incommensurate wavevectors. The gapping of these excitations corresponds to a
large entropy release and explains the reduction in the electronic specific
heat through the transition.


title:
Cylindrical Gravitational Waves in Expanding Universes: Explicit Pulse
  Solutions

abstract:
  Solutions analogous to the Weber-Wheeler cylindrical pulse waves are found
for the case of cylindrical gravitational waves in an expanding universe. These
pulse solutions mimic the asymptotic properties of waves from an isolated
source in three dimensions and can be used to test the far-field behavior of
numerical simulation techniques.


title:
HD 17156b: A Transiting Planet with a 21.2 Day Period and an Eccentric
  Orbit

abstract:
  We report the detection of transits by the 3.1 M_Jup companion to the V=8.17
G0V star HD 17156. The transit was observed by three independant observers on
Sept. 9/10, 2007 (two in central Italy and one in the Canary Islands), who
obtained detections at confidence levels of 3.0 sigma, 5.3 sigma, and 7.9
sigma, respectively. The observations were carried out under the auspices of
the Transitsearch.org network, which organizes follow-up photometric transit
searches of known planet-bearing stars during the time intervals when transits
are expected to possibly occur. Analyses of the 7.9 sigma data set indicates a
transit depth d=0.0062+/-0.0004, and a transit duration t=186+/-5 min. These
values are consistent with the transit of a Jupiter-sized planet with an impact
parameter b=a*cos(i)/R_star ~ 0.8. This planet occupies a unique regime among
known transiting extrasolar planets, both as a result of its large orbital
eccentricity (e=0.67) and long orbital period (P=21.2 d). The planet receives a
26-fold variation in insolation during the course of its orbit, which will make
it a useful object for characterization of exoplanetary atmospheric dynamics.


title:
Instability of P-waves just below the transition region in a global
  solar wind simulation

abstract:
  We investigate how wave propagation is modified by the presence of heat
sources and sinks, in the simple 1D, hydrodynamical case, including
chromosphere and solar wind. We integrate the time-dependent hydrodynamic
equations of the solar wind with spherical symmetry, including conduction,
radiative cooling and a prescribed mechanical heat flux. Once a
quasi-stationary wind is established, we study the response of the system to
pressure oscillations at the photospheric boundary. We use transparent boundary
conditions. We find that wavepackets with high enough amplitude propagating
upward from the photosphere implode just below the transition region. This
implosion is due to the radiative cooling term generating pressure holes close
to the wave crests of the wave, which make the wave collapse. In the case where
heat sources and sinks are not present in the equations, the wave remains
stable whatever the initial wave amplitude, which is compatible with published
work. Instability should be observable when and where the TR is high enough
above the optically thick regions.


title: A New Achievability Scheme for the Relay Channel

abstract:
  In this paper, we propose a new coding scheme for the general relay channel.
This coding scheme is in the form of a block Markov code. The transmitter uses
a superposition Markov code. The relay compresses the received signal and maps
the compressed version of the received signal into a codeword conditioned on
the codeword of the previous block. The receiver performs joint decoding after
it has received all of the B blocks. We show that this coding scheme can be
viewed as a generalization of the well-known Compress-And-Forward (CAF) scheme
proposed by Cover and El Gamal. Our coding scheme provides options for
preserving the correlation between the channel inputs of the transmitter and
the relay, which is not possible in the CAF scheme. Thus, our proposed scheme
may potentially yield a larger achievable rate than the CAF scheme.


title: Diffuse Interstellar Bands in z < 0.6 CaII Absorbers

abstract:
  The diffuse interstellar bands (DIBs) probably arise from complex organic
molecules whose strength in local galaxies correlates with neutral hydrogen
column density, N(HI), and dust reddening, E(B-V). Since CaII absorbers in
quasar (QSO) spectra are posited to have high N(HI) and significant E(B-V),
they represent promising sites for the detection of DIBs at cosmological
distances. Here we present the results from the first search for DIBs in 9
CaII-selected absorbers at 0.07 < z_abs < 0.55. We detect the 5780Ang DIB in
one line of sight at z_abs = 0.1556; this is only the second QSO absorber in
which a DIB has been detected. Unlike the majority of local DIB sight-lines,
both QSO absorbers with detected DIBs show weak 6284Ang absorption compared
with the 5780Ang band. This may be indicative of different physical conditions
in intermediate redshift QSO absorbers compared with local galaxies. Assuming
that local relations between the 5780Ang DIB strength and N(HI) and E(B-V)
apply in QSO absorbers, DIB detections and limits can be used to derive N(HI)
and E(B-V). For the one absorber in this study with a detected DIB, we derive
E(B-V) = 0.23mag and log[N(HI)] >= 20.9, consistent with previous conclusions
that CaII systems have high HI column densities and significant reddening. For
the remaining 8 CaII-selected absorbers with 5780Ang DIB non-detections, we
derive E(B-V) upper limits of 0.1-0.3mag.


title: Distinguishing quantum operations having few Kraus operators

abstract:
  Entanglement is sometimes helpful in distinguishing between quantum
operations, as differences between quantum operations can become magnified when
their inputs are entangled with auxiliary systems. Bounds on the dimension of
the auxiliary system needed to optimally distinguish quantum operations are
known in several situations. For instance, the dimension of the auxiliary space
never needs to exceed the dimension of the input space of the operations for
optimal distinguishability, while no auxiliary system whatsoever is needed to
optimally distinguish unitary operations. Another bound, which follows from
work of R. Timoney, is that optimal distinguishability is always possible when
the dimension of the auxiliary system is twice the number of operators needed
to express the difference between the quantum operations in Kraus form. This
paper provides an alternate proof of this fact that is based on concepts and
tools that are familiar to quantum information theorists.


title: Control and Monitoring System for Modular Wireless Robot

abstract:
  We introduce our concept on the modular wireless robot consisting of three
main modules : main unit, data acquisition and data processing modules. We have
developed a generic prototype with an integrated control and monitoring system
to enhance its flexibility, and to enable simple operation through a web-based
interface accessible wirelessly. In present paper, we focus on the
microcontroller based hardware to enable data acquisition and remote mechanical
control.


title:
A Quantitative Link Between Globular Clusters and the Stellar Halos in
  Elliptical Galaxies

abstract:
  This paper explores the quantitative connection between globular clusters and
the diffuse stellar population of the galaxies they are associated with. Both
NGC 1399 and NGC 4486 (M87) are well suited for this kind of analysis due to
their large globular cluster populations. The main assumption of our Monte
Carlo based models is that each globular cluster is formed along with a given
diffuse stellar mass that shares the same spatial distribution, chemical
composition and age. The main globular clusters subpopulations, that determine
the observed bimodal colour distribution, are decomposed avoiding a priori
parametric (e.g. Gaussian) fits and using a new colour (C-T1)-metallicity
relation. The eventual detectability of a blue tilt in the colour magnitude
diagrams of the blue globulars subpopulation is also addressed. A successful
link between globular clusters and the stellar galaxy halo is established by
assuming that the number of globular clusters per associated diffuse stellar
mass t is a function of total abundance [Z/H] and behaves as
t=gamma*exp(delta[Z/H]) (i.e. increases when abundance decreases).


title: Rank 2 vector bundles on ind-Grassmannians

abstract:
  The simplest example of an ind-Grassmannian is the infinite projective space
$\mathbf P^\infty$. The Barth-Van de Ven-Tyurin (BVT) Theorem, proved more than
30 years ago \cite{BV}, \cite{T}, \cite{Sa} (see also a recent proof by A.
Coand\u{a} and G. Trautmann, \cite{CT}), claims that any vector bundle of
finite rank on $\mathbf P^\infty$ is isomorphic to a direct sum of line
bundles. In the last decade natural examples of infinite flag varieties (or
flag ind-varieties) have arisen as homogeneous spaces of locally linear
ind-groups, \cite{DPW}, \cite{DiP}. In the present paper we concentrate our
attention to the special case of ind-Grassmannians, i.e. to inductive limits of
Grassmannians of growing dimension.


title: Bounded generalized Harish-Chandra modules

abstract:
  Let $\gg$ be a complex reductive Lie algebra and $\kk\subset\gg$ be any
reductive in $\gg$ subalgebra. We call a $(\gg,\kk)$-module $M$ bounded if the
$\kk$-multiplicities of $M$ are uniformly bounded. In this paper we initiate a
general study of simple bounded $(\gg,\kk)$-modules. We prove a strong
necessary condition for a subalgebra $\kk$ to be bounded (Corollary
\ref{cor1.6}), i.e. to admit an infinite-dimensional simple bounded
$(\gg,\kk)$-module, and then establish a sufficient condition for a subalgebra
$\kk$ to be bounded (Theorem \ref{thGroups2}). As a result we are able to
classify all maximal bounded reductive subalgebras of $\gg=\sl(n)$.
  In the second half of the paper we describe in detail simple bounded
infinite-dimensional $(\gg,\sl(2))$-modules, and in particular compute their
characters and minimal $\sl(2)$-types. We show that if $\sl(2)$ is a bounded
subalgebra of $\gg$ which is not contained in a proper ideal of $\gg$, then
$\gg\simeq \sl(2)\oplus \sl(2), \sl(3),\sp(4)$; alltogether, up to conjugation
there are five possible embeddings of $\sl(2)$ as a bounded subalgebra into
$\gg$ as above. In two of these cases $\sl(2)$ is a symmetric subalgebra, and
many results about simple bounded $(\gg,\sl(2))$-modules are known. A case
where our results are entirely new is the case of a principal
$\sl(2)$-subalgebra in $\sp(4)$.


title:
Spitzer IRAC Observations of White Dwarfs. I. Warm Dust at Metal-Rich
  Degenerates

abstract:
  This paper presents the results of a Spitzer IRAC 3-8 micron photometric
search for warm dust orbiting 17 nearby, metal-rich white dwarfs, 15 of which
apparently have hydrogen dominated atmospheres (type DAZ). G166-58, G29-38, and
GD 362 manifest excess emission in their IRAC fluxes and the latter two are
known to harbor dust grains warm enough to radiate detectable emission at
near-infrared wavelengths as short as 2 micron. Their IRAC fluxes display
differences compatible with a relatively larger amount of cooler dust at GD
362. G166-58 is presently unique in that it appears to exhibit excess flux only
at wavelengths longer than about 5 micron. Evidence is presented that this
mid-infrared emission is most likely associated with the white dwarf,
indicating that G166-58 bears circumstellar dust no warmer than T~400 K. The
remaining 14 targets reveal no reliable mid-infrared excess, indicating the
majority of DAZ stars do not have warm debris disks sufficiently opaque to be
detected by IRAC.


title:
The Starting and Stopping Problem under Knightian Uncertainty and
  Related Systems of Reflected BSDEs

abstract:
  This article deals with the starting and stopping problem under Knightian
uncertainty, i.e., roughly speaking, when the probability under which the
future evolves is not exactly known. We show that the lower price of a plant
submitted to the decisions of starting and stopping is given by a solution of a
system of two reflected backward stochastic differential equations (BSDEs for
short). We solve this latter system and we give the expression of the optimal
strategy. Further we consider a more general system of $m$ ($m\geq 2$)
reflected BSDEs with interconnected obstacles. Once more we show existence and
uniqueness of the solution of that system.


title:
Computation of expansions for the maximum likelihood estimator and its
  distribution function

abstract:
  In this paper, insight is given in the techniques used to compute asymptotic
expansions. In a broad fashion the technique is described. Most of the results
apply to the paper "An expansion for the maximum likelihood estimator and its
distribution function", which will be submitted.


title:
Charm spectroscopy on dynamical 2+1 flavor domain wall fermion lattices
  with a relativistic heavy quark action

abstract:
  We present a preliminary calculation of the charmonium spectrum using the
dynamical 2+1 flavor $24^3\times 64$ domain wall fermion lattice configurations
generated by the RBC and UKQCD collaborations. We use the relativistic heavy
quark action with 3 parameters non-perturbatively determined by matching to
experimental quantities. Chiral extrapolation is done on four light sea quark
masses from 0.005 to 0.03, with $m_s=0.04$ and $m_{res}=0.003$. We can either
predict meson masses assuming the lattice spacing is known from other methods,
or calculate the lattice spacing using those quantities.


title: Discrete sets with minimal moment of inertia

abstract:
  This paper has been withdrawn by the author due to a crucial error in the
proof of Theorem 1.


title:
Fano-Kondo effect in a two-level system with triple quantum dots: shot
  noise characteristics

abstract:
  We theoretically compare transport properties of Fano-Kondo effect with those
of Fano effect. We focus on shot noise characteristics of a triple quantum dot
(QD) system in the Fano-Kondo region at zero temperature, and discuss the
effect of strong electric correlation in QDs. We found that the modulation of
the Fano dip is strongly affected by the on-site Coulomb interaction in QDs.


title: Information flow within stochastic dynamical systems

abstract:
  Information flow or information transfer is an important concept in dynamical
systems which has applications in a wide variety of scientific disciplines. In
this study, we show that a rigorous formalism can be established in the context
of a generic stochastic dynamical system. The resulting measure of of
information transfer possesses a property of transfer asymmetry and, when the
stochastic perturbation to the receiving component does not rely on the giving
component, has a form same as that for the corresponding deterministic system.
An application with a two-dimensional system is presented, and the resulting
transfers are just as expected. A remarkable observation is that, for two
highly correlated time series, there could be no information transfer from one
certain series, say $x_2$, to the other ($x_1$). That is to say, the evolution
of $x_1$ may have nothing to do with $x_2$, even though $x_1$ and $x_2$ are
highly correlated. Information transfer analysis thus extends the traditional
notion of correlation analysis by providing a quantitative measure of causality
between time series.


title: Dynamics of Vacillating Voters

abstract:
  We introduce the vacillating voter model in which each voter consults two
neighbors to decide its state, and changes opinion if it disagrees with either
neighbor. This irresolution leads to a global bias toward zero magnetization.
In spatial dimension d>1, anti-coarsening arises in which the linear dimension
L of minority domains grows as t^{1/(d+1)}. One consequence is that the time to
reach consensus scales exponentially with the number of voters.


title: Hawking Radiation as Quantum Tunneling in Rindler Coordinate

abstract:
  We substantiate the Hawking radiation as quantum tunneling of fields or
particles crossing the horizon by using the Rindler coordinate. The thermal
spectrum detected by an accelerated particle is interpreted as quantum
tunneling in the Rindler spacetime. Representing the spacetime near the horizon
locally as a Rindler spacetime, we find the emission rate by tunneling, which
is expressed as a contour integral and gives the correct Boltzmann factor. We
apply the method to non-extremal black holes such as a Schwarzschild black
hole, a non-extremal Reissner-Nordstr\"{o}m black hole, a charged Kerr black
hole, de Sitter space, and a Schwarzschild-anti de Sitter black hole.


title: Acoustic phonon transport through a double-bend quantum waveguide

abstract:
  In this work, using the scattering matrix method, we have investigated the
transmission coefficients and the thermal conductivity in a double-bend
waveguide structure. The transmission coefficients show strong resonances due
to the scattering in the midsection of a double-bend structure; the positions
and the widths of the resonance peaks are determined by the dimensions of the
midsection of the structure. And the scattering in the double-bend structure
makes the thermal conductivity decreases with the increasing of the temperature
first, then increases after reaches a minimum. Furthermore, the investigations
of the multiple double-bend structures indicate that the first additional
double-bend structure suppresses the transmission coefficient and the frequency
gap formed; and the additional double-bend structures determine the numbers of
the resonance peaks at the frequency just above the gap region. These results
could be useful for the design of phonon devices.


title: Double power laws in income and wealth distributions

abstract:
  Close examination of wealth distributions reveal the existence of two
distinct power law regimes. The Pareto exponents of the super-rich, identified
for example in rich lists such as provided by Forbes are smaller than the
Pareto exponents obtained for top earners in income data sets. Our extension of
the Slanina model of wealth is able to reproduce these double power law
features.


title:
Comment: Disappearance of Metal-Like Behavior in GaAs Two-Dimensional
  Holes below 30 mK

abstract:
  The Comment claims the Huang et al. can be explained as a 2D Kondo effect and
as such does not represent a disappearance of metallic behavior. The density
dependence of the Kondo temperature is in good agreement with the data.


title: The ambient metric

abstract:
  This paper provides details of the construction, properties and some
applications of the ambient metric associated to a conformal class of metrics
on a smooth manifold. Existence and uniqueness of formal expansions defining
such metrics are considered. Equivalence with the expansions of associated
Poincare metrics is established. Definitions and properties of conformal
curvature tensors defined by ambient metrics together with formulation and
proof of a jet isomorphism theorem with application to the characterization of
scalar conformal invariants are given.


title: Polar-cap accelerator and radio emission from pulsars

abstract:
  Electric currents j flow along the open magnetic field lines from the polar
caps of neutron stars. Activity of a polar cap depends on the ratio
\alpha=j/c\rho_GJ, where \rho_GJ is the corotation charge density. The
customary assumption \alpha\approx 1 is not supported by recent simulations of
pulsar magnetospheres and we study polar caps with arbitrary \alpha. We argue
that no significant activity is generated on field lines with 0<\alpha<1.
Charges are extracted from the star and flow along such field lines with low
energies. By contrast, if \alpha>1 or \alpha<0, a high voltage is generated,
leading to unsteady e^+- discharge on a scale-height smaller than the size of
the polar cap. The discharge can power observed pulsars. Voltage fluctuations
in the discharge imply unsteady twisting of the open flux tube and generation
of Alfven waves. These waves are ducted along the tube and converted to
electromagnetic waves, providing a new mechanism for pulsar radiation.