title: Microstrip resonator for microwaves with controllable polarization

abstract:
  In this work the authors implemented a resonator based upon microstrip
cavities that permits the generation of microwaves with arbitrary polarization.
Design, simulation, and implementation of the resonators were performed using
standard printed circuit boards. The electric field distribution was mapped
using a scanning probe cavity perturbation technique. Electron spin resonance
using a standard marker was carried out in order to verify the polarization
control from linear to circular.


title:
Singular integral operators on variable Lebesgue spaces with radial
  oscillating weights

abstract:
  We prove a Fredholm criterion for operators in the Banach algebra of singular
integral operators with matrix piecewise continuous coefficients acting on a
variable Lebesgue space with a radial oscillating weight over a logarithmic
Carleson curve. The local spectra of these operators are massive and have a
shape of spiralic horns depending on the value of the variable exponent, the
spirality indices of the curve, and the Matuszewska-Orlicz indices of the
weight at each point. These results extend (partially) the results of A.
B\"ottcher, Yu. Karlovich, and V. Rabinovich for standard Lebesgue spaces to
the case of variable Lebesgue spaces.


title:
Real-time gauge theory simulations from stochastic quantization with
  optimized updating

abstract:
  We investigate simulations for gauge theories on a Minkowskian space-time
lattice. We employ stochastic quantization with optimized updating using
stochastic reweighting or gauge fixing, respectively. These procedures do not
affect the underlying theory but strongly improve the stability properties of
the stochastic dynamics, such that simulations on larger real-time lattices can
be performed.


title:
A weight function theory of zero order basis function interpolants and
  smoothers

abstract:
  I develop a weight func theory of zero order basis func interpolants and
smoothers.**Ch1 Basis funcs and data spaces are defined using wt funcs. Data
(native)spaces are used to formulate the variational problems which define our
interpolants /smoothers. Introduce the tensor prod extended B-splines.**Ch2
Prove the p'twise convergence of the minimal norm basis func interpol to its
data func and obtain orders of converg. Data func spaces for the B-splines are
locally Sobolev spaces.**Ch3 Another set of error estims for basis func
interpol. Use distrib'n Taylor expansion of exp(i(a,x)).**Ch4 Derive local
interpol errors for data funcs with bounded first derivs.**Ch5 Introduce class
of tensor prod wt funcs which I call the central diff wt funcs - related to the
B-splines. Apply theory to these wt funcs to obtain interpol converge results.
The data func spaces are locally Sobolev spaces. **Ch6 A non-param variat
smoothing problem studied with special interest in converge of smoother to its
data func. This smoother is the min norm interpol stabilized by a smoothing
coeff.**Ch7: A non-parametric, scalable, smoothing problem shown to converge to
its data func. We discuss the software which implements these algorithms.**Ch8:
Characterizes bounded linear functionals on data space.**Ch9 Bilinear form used
to characterize the bounded linear functionals on the data spaces generated by
the wt funcs.**Ch10 We derive an upper bound for the deriv of the 1-dim
(scaled) hat basis func smoother assuming the data func has bounded derivs and
large supp wrt. the data region.**Ch11: In one dim only; the local data funcs
are assumed to have bounded derivs on the data region and consider a scaled hat
basis func. If the basis func has large enough supp wrt. the data region then
we show the order of converg of the interpol is 1. **Ch12: Exten ops derived
based on Wloka; assumes rectangle condit.


title:
A new modified Galerkin method for the two-dimensional Navier-Stokes
  equations

abstract:
  We present a new type of modified Galerkin method. It is a construction with
several (inductively defined) levels, that provides approximate solutions of
increasing accuracy with every new level. These solutions are constructed as
approximations of the so called induced trajectories (notion on which the
definition of a class of approximate inertial manifolds used in the nonlinear
and postprocessed Galerkin methods is based).


title: Universal regularization prescription for Lovelock AdS gravity

abstract:
  A definite form for the boundary term that produces the finiteness of both
the conserved quantities and Euclidean action for any Lovelock gravity with AdS
asymptotics is presented. This prescription merely tells even from odd bulk
dimensions, regardless the particular theory considered, what is valid even for
Einstein-Hilbert and Einstein-Gauss-Bonnet AdS gravity. The boundary term is a
given polynomial of the boundary extrinsic and intrinsic curvatures (also
referred to as Kounterterms series). Only the coupling constant of the boundary
term changes accordingly, such that it always preserves a well-posed
variational principle for boundary conditions suitable for asymptotically AdS
spaces. The background-independent conserved charges associated to asymptotic
symmetries are found. In odd bulk dimensions, this regularization produces a
generalized formula for the vacuum energy in Lovelock AdS gravity. The standard
entropy for asymptotically AdS black holes is recovered directly from the
regularization of the Euclidean action, and not only from the first law of
thermodynamics associated to the conserved quantities.


title: The HMW effect in Noncommutative Quantum Mechanics

abstract:
  The HMW effect in non-commutative quantum mechanics is studied. By solving
the Dirac equations on non-commutative (NC) space and non-commutative phase
space, we obtain topological HMW phase on NC space and NC phase space
respectively, where the additional terms related to the space-space and
momentum-momentum non-commutativity are given explicitly.


title:
Doppler-Free Spectroscopy of Weak Transitions: An Analytical Model
  Applied to Formaldehyde

abstract:
  Experimental observation of Doppler-free signals for weak transitions can be
greatly facilitated by an estimate for their expected amplitudes. We derive an
analytical model which allows the Doppler-free amplitude to be estimated for
small Doppler-free signals. Application of this model to formaldehyde allows
the amplitude of experimentally observed Doppler-free signals to be reproduced
to within the experimental error.


title: SuperWASP-North Extra-solar Planet Candidates between 3hr < RA < 6hr

abstract:
  The Wide Angle Search for Planets (WASP) photometrically surveys a large
number of nearby stars to uncover candidate extrasolar planet systems by virtue
of small-amplitude lightcurve dips on a < 5-day timescale typical of the
``Hot-Jupiters.'' Observations with the SuperWASP-North instrument between
April and September 2004 produced a rich photometric dataset of some 1.3
billion datapoints from 6.7 million stars. Our custom-built data acquisition
and processing system produces ~0.02 mag photometric precision at V=13.
  We present the transit-candidates in the 03h-06h RA range. Of 141,895
lightcurves with sufficient sampling to provide adequate coverage, 2688 show
statistically significant transit-like periodicities. Of these, 44 pass visual
inspection of the lightcurve, of which 24 are removed through a set of cuts on
the statistical significance of artefacts. All but 4 of the remaining 20
objects are removed when prior information at higher spatial-resolution from
existing catalogues is taken into account. Of the four candidates remaining,
one is considered a good candidate for follow-up observations with three
further second-priority targets. We provide detailed information on these
candidates, as well as a selection of the false-positives and astrophysical
false-alarms that were eliminated, and discuss briefly the impact of sampling
on our results.


title:
Four-body quantum dynamics of two-center electronic transitions in
  relativistic ion-atom collisions and target recoil momentum spectroscopy

abstract:
  We consider relativistic collisions of heavy hydrogen-like ions with hydrogen
and helium atoms in which the ion-atom interaction causes both colliding
particles to undergo transitions between their internal states. Using an
approach enabling one, for the first time, to give a detailed description of
this important case of the relativistic quantum few-body problem we concentrate
on the study of the longitudinal momentum spectrum of the atomic recoil ions.
We discuss the role of relativistic and higher order effects, predict a
surprisingly strong influence of the projectile's electron on the momentum
transfer, draw the general picture of the recoil ion formation and show that
the important information about the doubly inelastic collisions could be
obtained in experiment merely by measuring the recoil momentum spectrum.


title:
Constraints on dark and visible mass in galaxies from strong
  gravitational lensing

abstract:
  We give a non-exhaustive review of the use of strong gravitational lensing in
placing constraints on the quantity of dark and visible mass in galaxies. We
discuss development of the methodology and summarise some recent results.


title:
Unidirectional d-wave superconducting domains in the two-dimensional t-J
  model

abstract:
  Motivated by the recently observed pattern of unidirectional domains in
high-T_c superconductors [Y. Kohsaka et al., Science 315, 1380 (2007)], we
investigate the emergence of spontaneous modulations in the d-wave
superconducting resonating valence bond phase using the t-J model at x=1/8
doping. Half-filled charge domains separated by four lattice spacings are found
to form along one of the crystal axis leading to modulated superconductivity
with out-of-phase d-wave order parameters in neighboring domains. Both
renormalized mean-field theory and variational Monte Carlo calculations yield
that the energies of modulated and uniform phases are very close to each other.


title: Theory of point contact spectroscopy in electron-doped cuprates

abstract:
  In the hole-doped $d_{x^{2}-y^{2}}$-wave cuprate superconductor, due to the
midgap surface state (MSS), a zero bias conductance peak (ZBCP) is widely
observed in [110] interface point contact spectroscopy (PCS). However, ZBCP of
this geometry is rarely observed in the electron-doped cuprates, even though
their pairing symmetry is still likely the $d_{x^{2}-y^{2}}$-wave. We argue
that this is due to the coexistence of antiferromagnetic (AF) and the
superconducting (SC) orders. Generalizing the Blonder-Tinkham-Klapwijk (BTK)
formula to include an AF coupling, it is shown explicitly that the MSS is
destroyed by the AF order. The calculated PCS is in good agreement with the
experiments.


title:
Stellar Evolutionary Effects on the Abundances of PAH and SN-Condensed
  Dust in Galaxies

abstract:
  Spectral and photometric observations of nearby galaxies show a correlation
between the strength of their mid-IR aromatic features, attributed to PAH
molecules, and their metal abundance, leading to a deficiency of these features
in low-metallicity galaxies. In this paper, we suggest that the observed
correlation represents a trend of PAH abundance with galactic age, reflecting
the delayed injection of carbon dust into the ISM by AGB stars in the final
post-AGB phase of their evolution. AGB stars are the primary sources of PAHs
and carbon dust in galaxies, and recycle their ejecta back to the interstellar
medium only after a few hundred million years of evolution on the main
sequence. In contrast, more massive stars that explode as Type II supernovae
inject their metals and dust almost instantaneously after their formation. We
first determined the PAH abundance in galaxies by constructing detailed models
of UV-to-radio SED of galaxies that estimate the contribution of dust in
PAH-free HII regions, and PAHs and dust from photodissociation regions, to the
IR emission. All model components: the galaxies' stellar content, properties of
their HII regions, and their ionizing and non-ionizing radiation fields and
dust abundances, are constrained by their observed multiwavelength spectrum.
After determining the PAH and dust abundances in 35 nearby galaxies using our
SED model, we use a chemical evolution model to show that the delayed injection
of carbon dust by AGB stars provides a natural explanation to the dependence of
the PAH content in galaxies with metallicity. We also show that larger dust
particles giving rise to the far-IR emission follow a distinct evolutionary
trend closely related to the injection of dust by massive stars into the ISM.


title: An unexpected outburst from A0535+262

abstract:
  A0535+262 is a transient Be/X-ray binary system which was in a quiescent
phase from 1994-2005. In this paper we report on the timing and spectral
properties of the INTEGRAL detection of the source in October 2003. The source
is detected for ~6000 seconds in the 18-100 keV energy band at a luminosity of
~3.8 x 10^{35} erg s^{-1}; this is compatible with the high end of the range of
luminosities expected for quiescent emission. The system is observed to be
outside of the centrifugal inhibition regime and pulsations are detected with
periodicity, P=103.7 +/- 0.1 seconds. An examination of the pulse history of
the source shows that it had been in a constant state of spin-down since it
entered the quiescent phase in 1994. The rate of spin-down implies the
consistent presence of an accretion disk supplying torques to the pulsar. The
observations show that the system is still active and highly variable even in
the absence of recent Type I or Type II X-ray outbursts.


title: The RHIC azimuth quadrupole: "perfect liquid" or gluonic radiation?

abstract:
  Large elliptic flow at RHIC seems to indicate that ideal hydrodynamics
provides a good description of Au-Au collisions, at least at the maximum RHIC
energy. The medium formed has been interpreted as a nearly perfect
(low-viscosity) liquid, and connections have been made to gravitation through
string theory. Recently, claimed observations of large flow fluctuations
comparable to participant eccentricity fluctuations seem to confirm the ideal
hydro scenario. However, determination of the azimuth quadrupole with 2D
angular autocorrelations, which accurately distinguish ``flow'' (quadrupole)
from ``nonflow'' (minijets), contradicts conventional interpretations.
Centrality trends may depend only on the initial parton geometry, and methods
used to isolate flow fluctuations are sensitive instead mainly to minijet
correlations. The results presented in this paper suggest that the azimuth
quadrupole may be a manifestation of gluonic multipole radiation.


title: Gravitational Field of A Radiating Star in Higher Dimensions

abstract:
  We obtain fields of a relativistic radiating star of non-static mass in the
framework of higher dimensional spacetime. Assuming energy-momentum tensor in
Higher dimensions analogous to that considered by Vaidya in 4 dimensions we
obtain solution of a radiating spherically symmetric star. The solution
obtained here is new in higher dimensions which however reduces to that
obtained by Vaidya in 4 dimensions. It is also different in form from that
obtained by Iyer and Vishveshwara. The interesting observation is that the
radius of a radiating star in higher dimensions oscillates. The radial size of
radiating star oscillates with a period which depends on the modes of vibration
and dimensions of the space-time.


title:
Spin blockade and lifetime-enhanced transport in a few-electron Si/SiGe
  double quantum dot

abstract:
  Spin blockade occurs when an electron is unable to access an energetically
favorable path through a quantum dot due to spin conservation, resulting in a
blockade of the current through the dot. Spin blockade is the basis of a number
of recent advances in spintronics, including the measurement and the
manipulation of individual electron spins. We report measurements of the spin
blockade regime in a silicon double quantum dot, revealing a complementary
phenomenon: lifetime-enhanced transport. We argue that our observations arise
because the decay times for electron spins in silicon are long, enabling the
electron to maintain its spin throughout its transit across the quantum dot and
access fast paths that exist in some spin channels but not in others. Such long
spin lifetimes are important for applications such as quantum computation and,
more generally, spintronics.


title:
A weight function theory of positive order basis function interpolants
  and smoothers

abstract:
  In this document I develop a weight function theory of positive order basis
function interpolants and smoothers. **In Chapter 1 the basis functions and
data spaces are defined directly using weight functions. The data spaces are
used to formulate the variational problems which define the interpolants and
smoothers discussed in later chapters. The theory is illustrated using some
standard examples of radial basis functions and two classes of weight functions
I will call the tensor product extended B-splines and the central difference
weight functions. **In Chapter 2 I derive modified inverse-Fourier transform
formulas for the basis functions and the data functions (native spaces) and to
use these formulas to obtain bounds for the rates of increase of these
functions and their derivatives near infinity. **Chapter 3 shows how to prove
functions are basis functions without using the awkward space of test functions
$S_{0,n}$ which are infinitely smooth functions of rapid decrease with several
zero-valued derivatives at the origin. Worked examples include several classes
of well-known radial basis functions. **In Chapter 4 we prove the existence and
uniqueness of a solution to the minimal seminorm interpolation problem. We then
derive orders for the pointwise convergence of the interpolant to its data
function as the density of the data increases. **In Chapter 5 a well-known
non-parametric variational smoothing problem will be studied with special
interest in the order of pointwise convergence of the smoother to its data
function. This smoothing problem is the minimal norm interpolation problem
stabilized by a smoothing coefficient. **In Chapter 6 a non-parametric,
scalable, variational smoothing problem will be studied, with special interest
in its order of pointwise convergence to its data function. **In Chapter 7 we
study the bounded linear functionals on the data spaces.


title: Summary of alphas determinations at ZEUS

abstract:
  The jet cross-section and structure-function measurements done with the ZEUS
detector to extract the strong coupling constant and to test its energy-scale
dependence are summarised. The values of alphas thus obtained and the HERA
average are also presented.


title: Near BPS Wilson Loop in beta-deformed Theories

abstract:
  We propose a definition of the Wilson loop operator in the N=1 beta-deformed
supersymmetric Yang-Mills theory. Although the operator is not BPS, it has a
finite expectation value at least up to order (g^2 N)^2. This does not happen
generally for a generic non-BPS Wilson loop whose expectation value is UV
divergent. For this reason we call this a near-BPS Wilson loop and conjecture
that its exact expectation value is finite. We derive the general form of the
boundary condition satisfied by the dual string worldsheet and find that it is
deformed. Finiteness of the expectation value of the Wilson loop, together with
some rather remarkable properties of the Lunin-Maldacena metric and the
B-field, fixes the boundary condition to be one which is characterized by the
vielbein of the deformed supergravity metric. The Wilson loop operators provide
natural candidates as dual descriptions to some of the existing D-brane
configurations in the Lunin-Maldacena background. We also construct the string
dual configuration for a near-1/4 BPS circular Wilson loop operator. The string
lies on a deformed three-sphere instead of a two-sphere as in the undeformed
case. The expectation value of the Wilson loop operator is computed using the
AdS/CFT correspondence and is found to be independent of the deformation. We
conjecture that the exact expectation value of the Wilson loop is given by the
same matrix model as in the undeformed case.


title: Cluster Complexes via Semi-Invariants

abstract:
  We define and study virtual representation spaces having both positive and
negative dimensions at the vertices of a quiver without oriented cycles. We
consider the natural semi-invariants on these spaces which we call virtual
semi-invariants and prove that they satisfy the three basic theorems: the First
Fundamental Theorem, the Saturation Theorem and the Canonical Decomposition
Theorem. In the special case of Dynkin quivers with n vertices this gives the
fundamental interrelationship between supports of the semi-invariants and the
Tilting Triangulation of the (n-1)-sphere.


title:
Tests of mode coupling theory in a simple model for two-component
  miscible polymer blends

abstract:
  We present molecular dynamics simulations on the structural relaxation of a
simple bead-spring model for polymer blends. The introduction of a different
monomer size induces a large time scale separation for the dynamics of the two
components. Simulation results for a large set of observables probing density
correlations, Rouse modes, and orientations of bond and chain end-to-end
vectors, are analyzed within the framework of the Mode Coupling Theory (MCT).
An unusually large value of the exponent parameter is obtained. This feature
suggests the possibility of an underlying higher-order MCT scenario for dynamic
arrest.


title: Elliptic flow in the Gaussian model of eccentricity fluctuations

abstract:
  We discuss a specific model of elliptic flow fluctuations due to Gaussian
fluctuations in the initial spatial $x$ and $y$ eccentricity components
$\left\{\mean{(\sigma_y^2-\sigma_x^2)/(\sigma_x^2+\sigma_y^2)},
\mean{2\sigma_{xy}/(\sigma_x^2+\sigma_y^2)} \right\}$. We find that in this
model $\vfour$, elliptic flow determined from 4-particle cumulants, exactly
equals the average flow value in the reaction plane coordinate system,
$\mean{v_{RP}}$, the relation which, in an approximate form, was found earlier
by Bhalerao and Ollitrault in a more general analysis, but under the same
assumption that $v_2$ is proportional to the initial system eccentricity. We
further show that in the Gaussian model all higher order cumulants are equal to
$\vfour$. Analysis of the distribution in the magnitude of the flow vector, the
$Q-$distribution, reveals that it is totally defined by two parameters,
$\vtwo$, the flow from 2-particle cumulants, and $\vfour$, thus providing
equivalent information compared to the method of cumulants. The flow obtained
from the $Q-$distribution is again $\vfour=\mean{v_{RP}}$.


title:
Rapid directional alignment of velocity and magnetic field in
  magnetohydrodynamic turbulence

abstract:
  We show that local directional alignment of the velocity and magnetic field
fluctuations occurs rapidly in magnetohydrodynamics for a variety of
parameters. This is observed both in direct numerical simulations and in solar
wind data. The phenomenon is due to an alignment between the magnetic field and
either pressure gradients or shear-associated kinetic energy gradients. A
similar alignment, of velocity and vorticity, occurs in the Navier Stokes fluid
case. This may be the most rapid and robust relaxation process in turbulent
flows, and leads to a local weakening of the nonlinear terms in the small scale
vorticity and current structures where alignment takes place.


title: From Percolation to Logarithmic Conformal Field Theory

abstract:
  The smallest deformation of the minimal model M(2,3) that can accommodate
Cardy's derivation of the percolation crossing probability is presented. It is
shown that this leads to a consistent logarithmic conformal field theory at
c=0. A simple recipe for computing the associated fusion rules is given. The
differences between this theory and the other recently proposed c=0 logarithmic
conformal field theories are underlined. The discussion also emphasises the
existence of invariant logarithmic couplings that generalise Gurarie's anomaly
number.


title:
On the all-order epsilon-expansion of generalized hypergeometric
  functions with integer values of parameters

abstract:
  We continue our study of the construction of analytical coefficients of the
epsilon-expansion of hypergeometric functions and their connection with Feynman
diagrams. In this paper, we apply the approach of obtaining iteratated
solutions to the differential equations associated with hypergeometric
functions to prove the following result (Theorem 1): The epsilon-expansion of a
generalized hypergeometric function with integer values of parameters is
expressible in terms of generalized polylogarithms with coefficients that are
ratios of polynomials. The method used in this proof provides an efficient
algorithm for calculatiing of the higher-order coefficients of Laurent
expansion.


title:
Some pseudo-Anosov maps on punctured Riemann surfaces represented by
  multi-twists

abstract: This paper has been withdrawn by the author


title: Cooperative Beamforming for Wireless Ad Hoc Networks

abstract:
  Via collaborative beamforming, nodes in a wireless network are able to
transmit a common message over long distances in an energy efficient fashion.
However, the process of making available the same message to all collaborating
nodes introduces delays. In this paper, a MAC-PHY cross-layer scheme is
proposed that enables collaborative beamforming at significantly reduced
collaboration overhead. It consists of two phases. In the first phase, nodes
transmit locally in a random access time-slotted fashion. Simultaneous
transmissions from multiple source nodes are viewed as linear mixtures of all
transmitted packets. In the second phase, a set of collaborating nodes, acting
as a distributed antenna system, beamform the received analog waveform to one
or more faraway destinations. This step requires multiplication of the received
analog waveform by a complex weight, which is independently computed by each
cooperating node, and which allows packets bound to the same destination to add
coherently at the destination node. Assuming that each node has access to
location information, the proposed scheme can achieve high throughput, which in
certain cases exceeds one. An analysis of the symbol error probability
corresponding to the proposed scheme is provided.


title:
Decomposition theorems and kernel theorems for a class of functional
  spaces

abstract:
  We prove new theorems about properties of generalized functions defined on
Gelfand-Shilov spaces $S^\beta$ with $0\le\beta<1$. For each open cone
$U\subset\mathbb R^d$ we define a space $S^\beta(U)$ which is related to
$S^\beta(\mathbb R^d)$ and consists of entire analytic functions rapidly
decreasing inside U and having order of growth $\le 1/(1-\beta)$ outside the
cone. Such sheaves of spaces arise naturally in nonlocal quantum field theory,
and this motivates our investigation. We prove that the spaces $S^\beta(U)$ are
complete and nuclear and establish a decomposition theorem which implies that
every continuous functional defined on $S^\beta(\mathbb R^d)$ has a unique
minimal closed carrier cone in $\mathbb R^d$. We also prove kernel theorems for
spaces over open and closed cones and elucidate the relation between the
carrier cones of multilinear forms and those of the generalized functions
determined by these forms.


title:
Dynamical magnetic susceptibility in the lamellar cobaltate
  superconductor Na_xCoO_2$\cdot y$H_2O

abstract:
  We systematically analyze the influence of the superconducting gap symmetry
and the electronic structure on the dynamical spin susceptibility in
superconducting Na_xCoO_2$\cdot y$H_2O within a three different models: the
single a_{1g}-band model with nearest-neighbor hoppings, the realistic
three-band t_{2g}-model with, and without e'_g pockets present at the Fermi
surface. We show that the magnetic response in the normal state is dominated by
the incommensurate antiferromagnetic spin density wave fluctuations at large
momenta in agreement with experimental temperature dependence of the
spin-lattice relaxation rate. Also, we demonstrate that the presence or the
absence of the e'_g-pockets at the Fermi surface does not affect significantly
this conclusion. In the superconducting state our results for d_{x^2-y^2}- or
d_{xy}-wave symmetries of the superconducting order parameter are consistent
with experimental data and exclude nodeless $d_{x^2-y^2} + id_{xy}$-wave
symmetry. We further point out that the spin-resonance peak proposed earlier is
improbable for the realistic band structure of Na_xCoO_2$\cdot y$H_2O.
Moreover, even if present the resonance peak is confined to the
antiferromagnetic wave vector and disappears away from it.


title:
Statistical comparison of ensemble implementations of Grover's search
  algorithm to classical sequential searches

abstract:
  We compare pseudopure state ensemble implementations, quantified by their
initial polarization and ensemble size, of Grover's search algorithm to
probabilistic classical sequential search algorithms in terms of their success
and failure probabilities. We propose a criterion for quantifying the resources
used by the ensemble implementation via the aggregate number of oracle
invocations across the entire ensemble and use this as a basis for comparison
with classical search algorithms. We determine bounds for a critical
polarization such that the ensemble algorithm succeeds with a greater
probability than the probabilistic classical sequential search. Our results
indicate that the critical polarization scales as N^(-1/4) where N is the
database size and that for typical room temperature solution state NMR, the
polarization is such that the ensemble implementation of Grover's algorithm
would be advantageous for N > 10^22


title: Compositional Bernoulli numbers

abstract:
  We define and study the combinatorial properties of compositional
  Bernoulli numbers and polynomials within the framework of rational
combinatorics.


title:
All-optical formation of a Bose-Einstein condensate for applications in
  scanning electron microscopy

abstract:
  We report on the production of a F=1 spinor condensate of 87Rb atoms in a
single beam optical dipole trap formed by a focused CO2 laser. The condensate
is produced 13mm below the tip of a scanning electron microscope employing
standard all-optical techniques. The condensate fraction contains up to 100,000
atoms and we achieve a duty cycle of less than 10s.


title: Star product algebras of test functions

abstract:
  We prove that the Gelfand-Shilov spaces $S^\beta_\alpha$ are topological
algebras under the Moyal star product if and only if $\alpha\ge\beta$. These
spaces of test functions can be used in quantum field theory on noncommutative
spacetime. The star product depends on the noncommutativity parameter
continuously in their topology. We also prove that the series expansion of the
Moyal product converges absolutely in $S^\beta_\alpha$ if and only if
$\beta<1/2$.


title: Quark-Gluon Plasmas and Thermalization

abstract:
  In these lectures, I will attempt a pedagogical and qualitative introduction
to the theory of equilibrium and thermalization of quark-gluon plasmas. I
assume only that the reader is familiar with quantum field theory at zero
temperature and with QCD as the theory of the strong interactions. I focus on
the limit of small alpha_s, which in principle should be relevant at extremely
high temperature because of asymptotic freedom, and in any case provides a
clean theoretical context in which to discuss a variety of phenomena. Topics
discussed include the basic equilibrium formalism for finite-temperature
quantum field theory, Debye screening, electric deconfinement, magnetic
confinement, dimensional reduction, plasma waves, kinetic theory, hydrodynamic
properties such as viscosity, the Landau-Pomeranchuk-Migdal effect,
thermalization in (arbitrarily high energy) heavy ion collisions, and QCD
plasma instabilities.


title:
Experimental test of nonlocal realistic theories without the rotational
  symmetry assumption

abstract:
  We analyze the class of nonlocal realistic theories that was originally
considered by Leggett [Found. Phys. 33, 1469 (2003)] and tested by us in a
recent experiment [Nature (London) 446, 871 (2007)]. We derive an
incompatibility theorem that works for finite numbers of polarizer settings and
that does not require the previously assumed rotational symmetry of the
two-particle correlation functions. The experimentally measured case involves
seven different measurement settings. Using polarization-entangled photon
pairs, we exclude this broader class of nonlocal realistic models by
experimentally violating a new Leggett-type inequality by 80 standard
deviations.


title: The Young Cluster Population of M82 Region B

abstract:
  We present observations obtained with the Advanced Camera for Surveys on
board the Hubble Space Telescope of the "fossil" starburst region B in the
nearby starburst galaxy M82. By comparing UBVI photometry with models, we
derive ages and extinctions for 35 U-band selected star clusters. We find that
the peak epoch of cluster formation occurred ~ 150 Myr ago, in contrast to
earlier work that found a peak formation age of 1.1 Gyr. The difference is most
likely due to our inclusion of U-band data, which are essential for accurate
age determinations of young cluster populations. We further show that the
previously reported turnover in the cluster luminosity function is probably due
to the neglect of the effect of extended sources on the detection limit. The
much younger cluster ages we derive clarifies the evolution of the M82
starburst. The M82-B age distribution now overlaps with the ages of: the
nuclear starburst; clusters formed on the opposite side of the disk; and the
last encounter with M81, some 220 Myr ago.


title:
Scaling Relations from Sunyaev-Zel'dovich Effect and Chandra X-ray
  measurements of high-redshift galaxy clusters

abstract:
  We present Sunyaev-Zel'dovich Effect (SZE) scaling relations for 38 massive
galaxy clusters at redshifts 0.14<z0.89, observed with both the Cchandra X-ray
Observatory and the centimeter-wave SZE imaging system at the BIMA and OVRO
interferometric arrays. An isothermal beta-model with central 100 kpc excluded
from the X-ray data is used to model the intracluster medium and to measure
global cluster properties. For each cluster, we measure the X-ray spectroscopic
temperature, SZE gas mass, total mass and integrated Compton-y parameters
within r_2500. Our measurements are in agreement with the expectations based on
a simple self-similar model of cluster formation and evolution. We compare the
cluster properties derived from our SZE observations with and without Chandra
spatial and spectral information and find them to be in good agreement. We
compare our results with cosmological numerical simulations, and find that
simulations that include radiative cooling, star formation and feedback match
well both the slope and normalization of our SZE scaling relations.


title:
Parton energy loss in an expanding quark-gluon plasma: Radiative vs
  collisional

abstract:
  We perform a comparison of the radiative and collisional parton energy losses
in an expanding quark-gluon plasma. The radiative energy loss is calculated
within the light-cone path integral approach. The collisional energy loss is
calculated using the Bjorken method with an accurate treatment of the binary
collision kinematics. Our numerical results demonstrate that for RHIC and LHC
conditions the collisional energy loss is relatively small in comparison to the
radiative one. We find an enhancement of the heavy quark radiative energy loss
as compared to that of the light quarks at high energies.


title:
Values at s=-1 of L-functions for multi-quadratic extensions of number
  fields, and the fitting ideal of the tame kernel

abstract:
  Fix a Galois extension E/F of totally real number fields such that the Galois
group G has exponent 2. Let S be a finite set of primes of F containing the
infinite primes and all those which ramify in E, let S_E denote the primes of E
lying above those in S, and let O_E^S denote the ring of S_E-integers of E. We
then compare the Fitting ideal of K_2(O_E^S) as a Z[G]-module with a higher
Stickelberger ideal. The two extend to the same ideal in the maximal order of
Q[G], and hence in Z[1/2][G]. Results in Z[G] are obtained under the assumption
of the Birch-Tate conjecture, especially for biquadratic extensions, where we
compute the index of the higher Stickelberger ideal.
  We find a sufficient condition for the Fitting ideal to contain the higher
Stickelberger ideal in the case where E is a biquadratic extension of F
containing the first layer of the cyclotomic Z_2-extension of F, and describe a
class of biquadratic extensions of F=Q that satisfy this condition.


title: Dressing the Giant Gluon

abstract:
  We demonstrate the applicability of the dressing method to the problem of
constructing new classical solutions for Euclidean worldsheets in anti-de
Sitter space. The motivation stems from recent work of Alday and Maldacena, who
studied gluon scattering amplitudes at strong coupling using a generalization
of a particular worldsheet found by Kruczenski whose edge traces a path
composed of light-light segments on the boundary of AdS. We dress this `giant
gluon' to find new solutions in AdS_3 and AdS_5 whose edges trace out more
complicated, timelike curves on the boundary. These solutions may be used to
calculate certain Wilson loops via AdS/CFT.


title: Shot Noise in SU(N) Quantum Dot Kondo Effects

abstract:
  We study shot noise in the current of quantum dots whose low-energy behaviour
corresponds to an SU(N) Kondo model, focusing on the case N=4 relevant to
carbon nanotube dots. For general N, two-particle Fermi liquid interactions
have two distinct effects: they can enhance the noise via back-scattering
processes with an N-dependent effective charge, and can also modify the
coherent partition noise already present without interactions. For N=4, in
contrast to the SU(2) case, interactions enhance shot noise solely through an
enhancement of partition noise. This leads to a non-trivial prediction for
experiment.


title: Multiple Sources toward the High-mass Young Star S140 IRS1

abstract:
  S140 IRS1 is a remarkable source where the radio source at the center of the
main bipolar molecular outflow in the region is elongated perpendicular to the
axis of the outflow, an orientation opposite to that expected if the radio
source is a thermal jet exciting the outflow. We present results of 1.3 cm
continuum and H2O maser emission observations made with the VLA in its A
configuration toward this region. In addition, we also present results of
continuum observations at 7 mm and re-analyse observations at 2, 3.5 and 6 cm
(previously published). IRS 1A is detected at all wavelengths, showing an
elongated structure. Three water maser spots are detected along the major axis
of the radio source IRS 1A. We have also detected a new continuum source at 3.5
cm (IRS 1C) located ~0.6'' northeast of IRS 1A. The presence of these two YSOs
(IRS 1A and 1C) could explain the existence of the two bipolar molecular
outflows observed in the region. In addition, we have also detected three
continuum clumps (IRS 1B, 1D and 1E) located along the major axis of IRS 1A. We
discuss two possible models to explain the nature of IRS 1A: a thermal jet and
an equatorial wind.


title: A massive cluster of Red Supergiants at the base of the Scutum-Crux arm

abstract:
  We report on the unprecedented Red Supergiant (RSG) population of a massive
young cluster, located at the base of the Scutum-Crux Galactic arm. We identify
candidate cluster RSGs based on {\it 2MASS} photometry and medium resolution
spectroscopy. With follow-up high-resolution spectroscopy, we use CO-bandhead
equivalent width and high-precision radial velocity measurements to identify a
core grouping of 26 physically-associated RSGs -- the largest such cluster
known to-date. Using the stars' velocity dispersion, and their inferred
luminosities in conjuction with evolutionary models, we argue that the cluster
has an initial mass of $\sim$40,000\msun, and is therefore among the most
massive in the galaxy. Further, the cluster is only a few hundred parsecs away
from the cluster of 14 RSGs recently reported by Figer et al (2006). These two
RSG clusters represent 20% of all known RSGs in the Galaxy, and now offer the
unique opportunity to study the pre-supernova evolution of massive stars, and
the Blue- to Red-Supergiant ratio at uniform metallicity. We use GLIMPSE,
MIPSGAL and MAGPIS survey data to identify several objects in the field of the
larger cluster which seem to be indicative of recent region-wide starburst
activity at the point where the Scutum-Crux arm intercepts the Galactic bulge.
Future abundance studies of these clusters will therefore permit the study of
the chemical evolution and metallicity gradient of the Galaxy in the region
where the disk meets the bulge.


title:
Thermal Emission from Transiting Very-Hot Jupiters: Prospects for
  Ground-based Detection at Optical Wavelengths

abstract:
  Very hot Jupiters (VHJs) are defined as Jupiter-mass extrasolar planets with
orbital periods shorter than three days. For low albedos the effective
temperatures of irradiated VHJs can reach 2500-3000 K. Thermal emission from
VHJs is therefore potentially strong at optical wavelengths. We explore the
prospects of detecting optical-wavelength thermal emission during secondary
eclipse with existing ground-based telescopes. We show that OGLE-TR-56b and
OGLE-TR-132b are the best suited candidates for detection, and that the
prospects are highest around z'-band (~0.9 microns). We also speculate that any
newly discovered VHJs with the right combination of orbital separation and host
star parameters could be thermally detected in the optical. The lack of
detections would still provide constraints on the planetary albedos and
re-radiation factors.


title: Toward metastable string vacua from magnetized branes

abstract:
  The scalar potential of recombination fields of magnetized branes in Type IIB
orientifold compactifications is analyzed in the absence of any closed string
fluxes. Considering its perturbative F and D-term contributions in a quadratic
approximation, we present the conditions for which its minima are
supersymmetric. We show that for reasonable conditions on the spectrum, both
metric moduli and recombination fields can be stabilized. We then provide
explicit examples of compact manifolds where a Minkowski vacuum is realized in
a Higgs phase. The vacuum energy is zero and some charged scalars acquire a
vev. We then address the question of supersymmetry breaking. The scalar
potential for recombination fields is analyzed when supersymmetry is broken by
F and D-term. We show that locally stable vacua can exist at the classical
level. These are formed by a hidden supersymmetric sector that fixes metric
moduli and recombination fields and a visible sector where supersymmetry is
spontaneously broken.


title: Existence of quasi-arcs

abstract:
  We show that doubling, linearly connected metric spaces are quasi-arc
connected. This gives a new and short proof of a theorem of Tukia.


title:
The Sloan Digital Sky Survey Quasar Lens Search. III. Constraints on
  Dark Energy from the Third Data Release Quasar Lens Catalog

abstract:
  We present cosmological results from the statistics of lensed quasars in the
Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking proper account of
the selection function, we compute the expected number of quasars lensed by
early-type galaxies and their image separation distribution assuming a flat
universe, which is then compared with 7 lenses found in the SDSS Data Release 3
to derive constraints on dark energy under strictly controlled criteria. For a
cosmological constant model (w=-1) we obtain
\Omega_\Lambda=0.74^{+0.11}_{-0.15}(stat.)^{+0.13}_{-0.06}(syst.). Allowing w
to be a free parameter we find
\Omega_M=0.26^{+0.07}_{-0.06}(stat.)^{+0.03}_{-0.05}(syst.) and
w=-1.1\pm0.6(stat.)^{+0.3}_{-0.5}(syst.) when combined with the constraint from
the measurement of baryon acoustic oscillations in the SDSS luminous red galaxy
sample. Our results are in good agreement with earlier lensing constraints
obtained using radio lenses, and provide additional confirmation of the
presence of dark energy consistent with a cosmological constant, derived
independently of type Ia supernovae.


title: Stellar populations across the NGC4244 truncated galactic disk

abstract:
  We use HST/ACS to study the resolved stellar populations of the nearby,
nearly edge-on galaxy NGC4244 across its outer disk surface density break. The
stellar photometry allows us to study the distribution of different stellar
populations and reach very low equivalent surface brightnesses. We find that
the break occurs at the same radius for young, intermediate age, and old stars.
The stellar density beyond the break drops sharply by a factor of at least 600
in 5 kpc. The break occurs at the same radius independent of height above the
disk, but is sharpest in the midplane and nearly disappears at large heights.
These results make it unlikely that truncations are caused by a star formation
threshold alone: the threshold would have to keep the same radial position from
less than 100 Myr to 10 Gyr ago, in spite of potential disturbances such as
infall and redistribution of gas by internal processes. A dynamical
interpretation of truncation formation is more likely such as due to angular
momentum redistribution by bars or density waves, or heating and stripping of
stars caused by the bombardment of dark matter sub-halos. The latter
explanation is also in quantitative agreement with the small diffuse component
we see around the galaxy.


title: Simulating Quantum Correlations with Finite Communication

abstract:
  Assume Alice and Bob share some bipartite $d$-dimensional quantum state. A
well-known result in quantum mechanics says that by performing two-outcome
measurements, Alice and Bob can produce correlations that cannot be obtained
locally, i.e., with shared randomness alone. We show that by using only two
bits of communication, Alice and Bob can classically simulate any such
correlations. All previous protocols for exact simulation required the
communication to grow to infinity with the dimension $d$. Our protocol and
analysis are based on a power series method, resembling Krivine's bound on
Grothendieck's constant, and on the computation of volumes of spherical
tetrahedra.


title:
The Sloan Digital Sky Survey Quasar Lens Search. II. Statistical Lens
  Sample from the Third Data Release

abstract:
  We report the first results of our systematic search for strongly lensed
quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky
Survey (SDSS). Among 46,420 quasars from the SDSS Data Release 3 (~4188 deg^2),
we select a subsample of 22,683 quasars that are located at redshifts between
0.6 and 2.2 and are brighter than the Galactic extinction corrected i-band
magnitude of 19.1. We identify 220 lens candidates from the quasar subsample,
for which we conduct extensive and systematic follow-up observations in optical
and near-infrared wavebands, in order to construct a complete lensed quasar
sample at image separations between 1'' and 20'' and flux ratios of faint to
bright lensed images larger than 10^{-0.5}. We construct a statistical sample
of 11 lensed quasars. Ten of these are galaxy-scale lenses with small image
separations (~1''-2'') and one is a large separation (15'') system which is
produced by a massive cluster of galaxies, representing the first statistical
sample of lensed quasars including both galaxy- and cluster-scale lenses. The
Data Release 3 spectroscopic quasars contain an additional 11 lensed quasars
outside the statistical sample.


title:
Discovery of 442-Hz Pulsations from an X-ray Source in the Globular
  Cluster NGC 6440

abstract:
  We report on the serendipitous discovery of a 442-Hz pulsar during a Rossi
X-ray Timing Explorer (RXTE) observation of the globular cluster NGC 6440. The
oscillation is detected following a burst-like event which was decaying at the
beginning of the observation. The time scale of the decay suggests we may have
seen the tail-end of a long-duration burst. Low-mass X-ray binaries (LMXBs) are
known to emit thermonuclear X-ray bursts that are sometimes modulated by the
spin frequency of the star, the so called burst oscillations. The pulsations
reported here are peculiar if interpreted as canonical burst oscillations. In
particular, the pulse train lasted for ~500 s, much longer than in standard
burst oscillations. The signal was highly coherent and drifted down by ~2x10^-3
Hz, much smaller than the ~Hz drifts typically observed during normal bursts.
The pulsations are reminiscent of those observed during the much more energetic
``superbursts'', however, the temporal profile and the energetics of the burst
suggest that it was not the tail end nor the precursor feature of a superburst.
It is possible that we caught the tail end of an outburst from a new
`intermittent'' accreting X-ray millisecond pulsar, a phenomenon which until
now has only been seen in HETE J1900.1$-$2455 (Galloway et al. 2007). We note
that (Kaaret et al. 2003) reported the discovery of a 409.7 Hz burst
oscillation from SAX J1748.9-2021, also located in NGC 6440. However, Chandra
X-ray
  Observatory imaging indicates it contains several point-like X-ray sources,
thus the 442 Hz object is likely a different source.


title: Constraining Dark Energy Anisotropic Stress

abstract:
  We investigate the possibility of using cosmological observations to probe
and constrain an imperfect dark energy fluid. We consider a general
parameterization of the dark energy component accounting for an equation of
state, speed of sound and viscosity. We use present and future data from the
cosmic microwave background radiation (CMB), large scale structures and
supernovae type Ia. We find that both the speed of sound and viscosity
parameters are difficult to nail down with the present cosmological data. Also,
we argue that it will be hard to improve the constraints significantly with
future CMB data sets. The implication is that a perfect fluid description might
ultimately turn out to be a phenomenologically sufficient description of all
the observational consequences of dark energy. The fundamental lesson is
however that even then one cannot exclude, by appealing to observational
evidence alone, the possibility of imperfectness in dark energy.


title:
Photon wave functions, wave-packet quantization of light, and coherence
  theory

abstract:
  The monochromatic Dirac and polychromatic Titulaer-Glauber quantized field
theories (QFTs) of electromagnetism are derived from a photon-energy wave
function in much the same way that one derives QFT for electrons, that is, by
quantization of a single-particle wave function. The photon wave function and
its equation of motion are established from the Einstein energy-momentum-mass
relation, assuming a local energy density. This yields a theory of photon wave
mechanics (PWM). The proper Lorentz-invariant single-photon scalar product is
found to be non-local in coordinate space, and is shown to correspond to
orthogonalization of the Titulaer-Glauber wave-packet modes. The wave functions
of PWM and mode functions of QFT are shown to be equivalent, evolving via
identical equations of motion, and completely describe photonic states. We
generalize PWM to two or more photons, and show how to switch between the PWM
and QFT viewpoints. The second-order coherence tensors of classical coherence
theory and the two-photon wave functions are shown to propagate equivalently.
We give examples of beam-like states, which can be used as photon wave
functions in PWM, or modes in QFT. We propose a practical mode converter based
on spectral filtering to convert between wave packets and their corresponding
biorthogonal dual wave packets.


title: Two Jovian-Mass Planets in Earthlike Orbits

abstract:
  We report the discovery of two new planets: a 1.94 M_Jup planet in a 1.8-year
orbit of HD 5319, and a 2.51 M_Jup planet in a 1.1-year orbit of HD 75898. The
measured eccentricities are 0.12 for HD 5319 b and 0.10 for HD 75898 b, and
Markov Chain Monte Carlo simulations based on derived orbital parameters
indicate that the radial velocities of both stars are consistent with circular
planet orbits. With low eccentricity and 1 < a < 2 AU, our new planets have
orbits similar to terrestrial planets in the solar system. The radial velocity
residuals of both stars have significant trends, likely arising from substellar
or low-mass stellar companions.


title: The Host Galaxy of GRB 060505: Host ISM Properties

abstract:
  We investigate the ISM environment of GRB 060505. Using optical emission-line
diagnostic ratios, we compare the ISM properties of the GRB 060505 host region
with the hosts of unambiguous long- and short-duration GRBs. We show that the
metallicity, ionization state, and star formation rate of the GRB 060505
environment are more consistent with short-duration GRBs than with
long-duration GRBs. We compare the metallicity and star formation rates of the
GRB 060505 region with four other star-forming regions within the GRB 060505
host galaxy. We find no significant change in metallicity or star formation
rate between the GRB 060505 region and the other four host regions. Our results
are consistent with a compact-object-merger progenitor for GRB 060505.


title: TrES-4: A Transiting Hot Jupiter of Very Low Density

abstract:
  We report the discovery of TrES-4, a hot Jupiter that transits the star GSC
02620-00648 every 3.55 days. From high-resolution spectroscopy of the star we
estimate a stellar effective temperature of Teff = 6100 +/- 150 K, and from
high-precision z and B photometry of the transit we constrain the ratio of the
semi-major axis and the stellar radius to be a/R = 6.03 +/- 0.13. We compare
these values to model stellar isochrones to constrain the stellar mass to be M*
= 1.22 +/- 0.17 Msun. Based on this estimate and the photometric time series,
we constrain the stellar radius to be R* = 1.738 +/- 0.092 Rsun and the planet
radius to be Rp = 1.674 +/- 0.094 RJup. We model our radial-velocity data
assuming a circular orbit and find a planetary mass of 0.84 +/- 0.10 MJup. Our
radial-velocity observations rule out line-bisector variations that would
indicate a specious detection resulting from a blend of an eclipsing binary
system. TrES-4 has the largest radius and lowest density of any of the known
transiting planets. It presents a challenge to current models of the physical
structure of hot Jupiters, and indicates that the diversity of physical
properties amongst the members of this class of exoplanets has yet to be fully
explored.


title:
Rest-Frame Ultraviolet to Near Infrared Observations of an Interacting
  Lyman Break Galaxy at z = 4.42

abstract:
  We present the rest-frame ultraviolet through near infrared spectral energy
distribution for an interacting Lyman break galaxy at a redshift z=4.42, the
highest redshift merging system known with clearly resolved tidal features. The
two objects in this system - HDF-G4 and its previously unidentified companion -
are both B_{435} band dropouts, have similar V_{606}-i_{775} and
i_{775}-z_{850} colors, and are separated by 1", which at z=4.42 corresponds to
7 kpc projected nuclear separation; all indicative of an interacting system.
Fits to stellar population models indicate a stellar mass of M_\star =
2.6\times 10^{10} M_\odot, age of \tau_\star = 720 My, and exponential star
formation history with an e-folding time \tau_0 = 440 My. Using these derived
stellar populations as constraints, we model the HDF-G4 system using
hydrodynamical simulations, and find that it will likely evolve into a quasar
by z\sim3.5, and a quiescent, compact spheroid by z\sim 2.5 similar to those
observed at z > 2. And, the existence of such an object supports galaxy
formation models in which major mergers drive the high redshift buildup of
spheroids and black holes.


title:
Can experiments distinguish between Radiative Electroweak Symmetry
  breaking and Conventional breaking?

abstract:
  We present a comparative study of radiative electroweak symmetry breaking and
conventional standard model breaking, and pose the question whether experiments
can distinguish one breaking mode from the other. The importance of the problem
lies in the fact that the two breaking modes have very different physical
interpretations concerning the mechanism of spontaneous electroweak symmetry
breaking and the origin of mass.


title: Atomic Collapse and Quasi-Rydberg States in Graphene

abstract:
  Charge impurities in graphene can host an infinite family of Rydberg-like
resonance states of massless Dirac particles. These states, appearing for
supercritical charge, are described by Bohr-Sommerfeld quantization of
collapsing classical trajectories that descend on point charge, in analogy to
Rydberg states relation with planetary orbits. We argue that divalent and
trivalent charge impurities in graphene is an ideal system for realization of
this atomic collapse regime. Strong coupling of these states to the Dirac
continuum via Klein tunneling leads to striking resonance effects with direct
signatures in transport, local properties and enhancement of the Kondo effect.


title: A separable non-remainder of H

abstract:
  We prove that there is a compact separable continuum that (consistently) is
not a remainder of the real line.


title: Quantum graphs where back-scattering is prohibited

abstract:
  We describe a new class of scattering matrices for quantum graphs in which
back-scattering is prohibited. We discuss some properties of quantum graphs
with these scattering matrices and explain the advantages and interest in their
study. We also provide two methods to build the vertex scattering matrices
needed for their construction.


title: Multiple complex networks emerging from individual interactions

abstract:
  Systems composed of distinct complex networks are present in many real-world
environments, from society to ecological systems. In the present paper, we
propose a network model obtained as a consequence of interactions between two
species (e.g. predator and prey). Fields are produced and sensed by the
individuals, defining spatio-temporal patterns which are strongly affected by
the attraction intensity between individuals from the same species. The
dynamical evolution of the system, including the change of individuals between
different clusters, is investigated by building two complex networks having the
individuals as nodes. In the first network, the edge weight is given by the
Euclidean distance between every two individuals and, in the case of the second
network, by the amount of time two individuals stay close one another. A third
network is obtained from the two previous networks whose nodes correspond to
the spatially congruent groups. The system evolves to an organized state where
Gaussian and scale-free-like strength distributions emerge, respectively, in
the predator and prey networks. Such a different connectivity is mainly a
consequence of preys elimination. Some configurations favor the survival of
preys or higher efficiency of predator activity.


title: Triangularization of a Jordan Algebra of Schatten Operators

abstract:
  We show that a Jordan algebra of compact quasinilpotent operators which
contains a nonzero trace class operator has a common invariant subspace. As a
consequence of this result, we obtain that a Jordan algebra of quasinilpotent
Schatten operators is simultaneously triangularizable.


title:
The Crepant Resolution Conjecture for 3-dimensional flags modulo an
  involution

abstract:
  After fixing a non-degenerate bilinear form on a vector space V we define an
involution of the manifold of flags F in V by taking a flag to its orthogonal
complement. When V is of dimension 3 we check that the Crepant Resolution
Conjecture of J. Bryan and T. Graber holds: the genus zero (orbifold)
Gromov-Witten potential function of [F / Z_2] agrees (up to unstable terms)
with the genus zero Gromov-Witten potential function of a crepant resolution Y
of the quotient scheme F / Z_2, after setting a quantum parameter to -1, making
a linear change of variables, and analytically continuing coefficients. The
crepant resolution Y (a hypersurface in the Hilbert scheme Hilb^2 P^2) is the
projectivization of a novel rank 2 vector bundle over P^2.


title: Landau levels and oscillator strength in a biased bilayer of graphene

abstract:
  We obtain analytical expressions for the eigenstates and the Landau level
spectrum of biased graphene bilayers in a magnetic field. The calculations are
performed in the context of a four-band continuum model and generalize previous
approximate results. Solutions are presented for the spectrum as a function of
interlayer coupling, the potential difference between the layers and the
magnetic field. The explicit expressions allow us to calculate the oscillator
strength and the selection rules for electric dipole transitions between the
Landau states. Some transitions are significantly shifted in energy relative to
those in an unbiased bialyer and exhibit a very different magnetic field
dependence.


title: Emergence of Small-Scale Magnetic Loops in the Quiet Sun Internetwork

abstract:
  We study the emergence of magnetic flux at very small spatial scales (less
than 2 arcsec) in the quiet Sun internetwork. To this aim, a time series of
spectropolarimetric maps was taken at disk center using the instrument SP/SOT
on board Hinode. The LTE inversion of the full Stokes vector measured in the Fe
I 6301 and 6302 A lines allows us to retrieve the magnetic flux and topology in
the region of study. In the example presented here, the magnetic flux emerges
within a granular structure. The horizontal magnetic field appears prior to any
significant amount of vertical field. As time goes on, the traces of the
horizontal field disappear while the the vertical dipoles drift -carried by the
plasma motions- towards the surrounding intergranular lanes. These events take
place within typical granulation timescales.


title:
The SCUBA HAlf Degree Extragalactic Survey (SHADES) -- V. Submillimetre
  properties of near-infrared--selected galaxies in the Subaru/XMM--Newton deep
  field

abstract:
  We have studied the submillimetre (submm) properties of the following classes
of near-infrared (NIR)-selected massive galaxies at high redshifts:
BzK-selected star-forming galaxies (BzKs); distant red galaxies (DRGs); and
extremely red objects (EROs). We used the SCUBA HAlf Degree Extragalactic
Survey (SHADES), the largest uniform submm survey to date. Partial overlap of
SIRIUS/NIR images and SHADES in SXDF has allowed us to identify 4 submm-bright
NIR-selected galaxies, which are detected in the mid-infrared, 24 micron, and
the radio, 1.4 GHz. We find that all of our submm-bright NIR-selected galaxies
satisfy the BzK selection criteria, except for one galaxy whose B-z and z-K
colours are however close to the BzK colour boundary. Two of the submm-bright
NIR-selected galaxies satisfy all of the selection criteria we considered, i.e.
they belong to the BzK-DRG-ERO overlapping population, or `extremely red' BzKs.
Although these extremely red BzKs are rare (0.25 arcmin^{-2}), up to 20 % of
this population could be submm galaxies. This fraction is significantly higher
than that found for other galaxy populations studied here. Via a stacking
analysis, we have detected the 850 micron flux of submm-faint BzKs and EROs in
our SCUBA maps. While the contribution of z~2 BzKs to the submm background is
about 10--15 % and similar to that from EROs typically at z~1, BzKs have a
higher fraction (~30 %) of submm flux in resolved sources compared with EROs
and submm sources as a whole. From the SED fitting analysis for both
submm-bright and submm-faint BzKs, we found no clear signature that
submm-bright BzKs are experiencing a specifically luminous evolutionary phase,
compared with submm-faint BzKs. An alternative explanation might be that
submm-bright BzKs are more massive than submm-faint ones.


title: Cooperative game theory and the Gaussian interference channel

abstract:
  In this paper we discuss the use of cooperative game theory for analyzing
interference channels. We extend our previous work, to games with N players as
well as frequency selective channels and joint TDM/FDM strategies.
  We show that the Nash bargaining solution can be computed using convex
optimization techniques. We also show that the same results are applicable to
interference channels where only statistical knowledge of the channel is
available. Moreover, for the special case of two players $2\times K$ frequency
selective channel (with K frequency bins) we provide an $O(K \log_2 K)$
complexity algorithm for computing the Nash bargaining solution under mask
constraint and using joint FDM/TDM strategies. Simulation results are also
provided.


title: Direct Observational Test Rules Out Small MgII Absorbers

abstract:
  Recent observations suggest the incidence of strong intervening MgII
absorption systems along the line-of-sight to gamma ray burst (GRB) afterglows
is significantly higher than expected from analogous quasar sightlines. One
possible explanation is a geometric effect, arising because MgII absorbers only
partially cover the quasar continuum regions, in which case MgII absorbers must
be considerably smaller than previous estimates. We investigate the production
of abnormal absorption profiles by partial coverage and conclude that the lack
of any known anomalous profiles in observed systems, whilst constraining,
cannot on its own rule out patchy MgII absorbers.
  In a separate test, we look for differences in the distribution function of
MgII equivalent widths over quasar continuum regions and CIII] emission lines.
We show that these anomalies should be observable in any scenario where MgII
absorbers are very small, but they are not present in the data. We conclude
that models invoking small MgII cloudlets to explain the excess of absorbers
seen towards GRBs are ruled out.


title:
Validation of spallation neutron production and propagation within
  Geant4

abstract:
  Using simulations to understand backgrounds from muon-induced neutrons is
important in designing next-generation low-background underground experiments.
Validation of relevant physics within the Geant4 simulation package has been
completed by comparing to data from two recent experiments. Verification
focused on the production and propagation of neutrons at energies important to
underground experiments. Discrepancies were observed between experimental data
and the simulation. Techniques were explored to correct for these
discrepancies.


title:
The mass-critical nonlinear Schr\"odinger equation with radial data in
  dimensions three and higher

abstract:
  We establish global well-posedness and scattering for solutions to the
mass-critical nonlinear Schr\"odinger equation $iu_t + \Delta u = \pm |u|^{4/d}
u$ for large spherically symmetric L^2_x(R^d) initial data in dimensions $d\geq
3$. In the focusing case we require that the mass is strictly less than that of
the ground state. As a consequence, we obtain that in the focusing case, any
spherically symmetric blowup solution must concentrate at least the mass of the
ground state at the blowup time.


title:
Relations between random coding exponents and the statistical physics of
  random codes

abstract:
  The partition function pertaining to finite--temperature decoding of a
(typical) randomly chosen code is known to have three types of behavior,
corresponding to three phases in the plane of rate vs. temperature: the {\it
ferromagnetic phase}, corresponding to correct decoding, the {\it paramagnetic
phase}, of complete disorder, which is dominated by exponentially many
incorrect codewords, and the {\it glassy phase} (or the condensed phase), where
the system is frozen at minimum energy and dominated by subexponentially many
incorrect codewords. We show that the statistical physics associated with the
two latter phases are intimately related to random coding exponents. In
particular, the exponent associated with the probability of correct decoding at
rates above capacity is directly related to the free energy in the glassy
phase, and the exponent associated with probability of error (the error
exponent) at rates below capacity, is strongly related to the free energy in
the paramagnetic phase. In fact, we derive alternative expressions of these
exponents in terms of the corresponding free energies, and make an attempt to
obtain some insights from these expressions. Finally, as a side result, we also
compare the phase diagram associated with a simple finite-temperature universal
decoder for discrete memoryless channels, to that of the finite--temperature
decoder that is aware of the channel statistics.


title: Towards linear phononics and nonlocality tests in ion traps

abstract:
  We explore the possibility to manipulate massive, i.e. motional, degrees of
freedom of trapped ions. In particular, we demonstrate that, if local control
of the trapping frequencies is achieved, one can reproduce the full toolbox of
linear optics on radial modes. Furthermore, assuming only global control of the
trapping potential, we show that unprecedented degrees of continuous variable
entanglement can be obtained and that nonlocality tests with massive degrees of
freedom can be carried out.


title:
Starbursts in the Local Universe: new HST/ACS observations of the
  irregular galaxy NGC 4449

abstract:
  We present photometry with the Advanced Camera for Surveys (ACS) on the
Hubble Space Telescope (HST) of stars in the Magellanic starburst galaxy NGC
4449. The galaxy has been imaged in the F435W (B), F555W (V) and F814W (I)
broad-band filters, and in the F658N (Halpha) narrow-band filter. Our
photometry includes ~300,000 objects in the (B, V) color-magnitude diagram
(CMD) down to V < 28, and ~400,000 objects in the (V, I) CMD, down to I < 27 .
A subsample of ~200,000 stars has been photometrized in all the three bands
simultaneously. The features observed in the CMDs imply a variety of stellar
ages up to at least 1 Gyr, and possibly as old as a Hubble time. The spatial
variation of the CMD morphology and of the red giant branch colors point toward
the presence of an age gradient: young and intermediate-age stars tend to be
concentrated toward the galactic center, while old stars are present
everywhere. The spatial variation in the average luminosity of carbon stars
suggests that there is not a strong metallicity gradient (< 0.2 dex). Also, we
detect an interesting resolved star cluster on the West side of the galaxy,
surrounded by a symmetric tidal or spiral feature consisting of young stars.
The positions of the stars in NGC 4449 younger than 10 Myr are strongly
correlated with the Halpha emission. We derive the distance of NGC 4449 from
the tip of the red giant branch to be D=3.82 \pm 0.27 Mpc. This result is in
agreement with the distance that we derive from the luminosity of the carbon
stars.


title: Embeddings of discrete groups and the speed of random walks

abstract:
  For a finitely generated group G and a banach space X let \alpha^*_X(G)
(respectively \alpha^#_X(G)) be the supremum over all \alpha\ge 0 such that
there exists a Lipschitz mapping (respectively an equivariant mapping) f:G\to X
and c>0 such that for all x,y\in G we have \|f(x)-f(y)\|\ge c\cdot
d_G(x,y)^\alpha. In particular, the Hilbert compression exponent (respectively
the equivariant Hilbert compression exponent) of G is
\alpha^*(G)=\alpha^*_{L_2}(G) (respectively \alpha^#(G)= \alpha_{L_2}^#(G)). We
show that if X has modulus of smoothness of power type p, then \alpha^#_X(G)\le
\frac{1}{p\beta^*(G)}. Here \beta^*(G) is the largest \beta\ge 0 for which
there exists a set of generators S of G and c>0 such that for all t\in \N we
have \E\big[d_G(W_t,e)\big]\ge ct^\beta, where \{W_t\}_{t=0}^\infty is the
canonical simple random walk on the Cayley graph of G determined by S, starting
at the identity element. This result is sharp when X=L_p, generalizes a theorem
of Guentner and Kaminker and answers a question posed by Tessera. We also show
that if \alpha^*(G)\ge 1/2 then \alpha^*(G\bwr \Z)\ge
\frac{2\alpha^*(G)}{2\alpha^*(G)+1}. This improves the previous bound due to
Stalder and ValetteWe deduce that if we write \Z_{(1)}= \Z and
\Z_{(k+1)}\coloneqq \Z_{(k)}\bwr \Z then
\alpha^*(\Z_{(k)})=\frac{1}{2-2^{1-k}}, and use this result to answer a
question posed by Tessera in on the relation between the Hilbert compression
exponent and the isoperimetric profile of the balls in G. We also show that the
cyclic lamplighter groups C_2\bwr C_n embed into L_1 with uniformly bounded
distortion, answering a question posed by Lee, Naor and Peres. Finally, we use
these results to show that edge Markov type need not imply Enflo type.


title:
On the point spectrum of some perturbed differential operators with
  periodic coefficients

abstract:
  Finiteness of the point spectrum of linear operators acting in a Banach space
is investigated from point of view of perturbation theory. In the first part of
the paper we present an abstract result based on analytical continuation of the
resolvent function through continuous spectrum. In the second part, the
abstract result is applied to differential operators which can be represented
as a differential operator with periodic coefficients perturbed by an arbitrary
subordinated differential operator.


title: Kinetic corrections to B -> X_c l nu at one loop

abstract:
  We evaluate the one-loop corrections to the Wilson coefficient of the kinetic
operator in the operator product expansion of the differential B -> X_c l nu
decay rate. With a moderate cut on the lepton energy, the one-loop terms change
the kinetic operator contributions to spectral moments by about 20%. This
amounts to a small correction for leptonic and hadronic moments, except for
those which vanish at the lowest order, where the effect can be sizable.
Together with a two-loop calculation of the leading-power rate and an
evaluation of the one-loop corrections to the Wilson coefficient of the
chromo-magnetic operator, our results will allow for a high-precision
determination of |V_cb| and the b- and c-quark masses.


title:
Triple oscillating field technique for accurate measurements of
  couplings in homonuclear spin systems

abstract:
  We present a new concept for homonuclear dipolar recoupling in
magic-angle-spinning (MAS) solid-state NMR experiments which avoids the problem
of dipolar truncation. This is accomplished through the introduction of a new
NMR pulse sequence design principle: the triple oscillating field technique. We
demonstrate this technique as an efficient means to accomplish broadband
dipolar recoupling of homonuclear spins, while decoupling heteronuclear dipolar
couplings and anisotropic chemicals shifts and retaining influence from
isotropic chemical shifts. In this manner, it possible to synthesize Ising
interactions in homonuclear spin networks and thereby avoid dipolar truncation
- a serious problem essentially all previous homonuclear dipolar recoupling
experiments suffer from. Combination of this recoupling concept with rotor
assisted dipolar refocusing enables easy readout of internuclear distances
through comparison with analytical Fresnel curves. This forms the basis for a
new class of solid-state NMR experiments with potential for structure analysis
of uniformly carbon labelled proteins through accurate measurement of
{13}C-{13}C internuclear distances. The concept is demonstrated experimentally
by measurement of C_alpha-C', C_\beta-C', and C_\gamma-C' internuclear
distances in powder samples of the amino acids \textit{L}-alanine and
\textit{L}-threonine.


title: The effects of clumping on wind line variability

abstract:
  We review the effects of clumping on the profiles of resonance doublets. By
allowing the ratio of the doublet oscillator strenghts to be a free parameter,
we demonstrate that doublet profiles contain more information than is normally
utilized. In clumped (or porous) winds, this ratio can lies between unity and
the ratio of the f-values, and can change as a function of velocity and time,
depending on the fraction of the stellar disk that is covered by material
moving at a particular velocity at a given moment. Using these insights, we
present the results of SEI modeling of a sample of B supergiants, zeta Pup and
a time series for a star whose terminal velocity is low enough to make the
components of its Si IV 1400 doublet independent. These results are interpreted
within the framework of the Oskinova et al. (2007) model, and demonstrate how
the doublet profiles can be used to extract infromation about wind structure.


title: Fermi-surface calculation of the anomalous Hall conductivity

abstract:
  While the intrinsic anomalous Hall conductivity is normally written in terms
of an integral of the electronic Berry curvature over the occupied portions of
the Brillouin zone, Haldane has recently pointed out that this quantity (or
more precisely, its ``non-quantized part'') may alternatively be expressed as a
Fermi-surface property. Here we present an {\it ab-initio} approach for
computing the anomalous Hall conductivity that takes advantage of this
observation by converting the integral over the Fermi sea into a more efficient
integral on the Fermi surface only. First, a conventional electronic-structure
calculation is performed with spin-orbit interaction included.
Maximally-localized Wannier functions are then constructed by a post-processing
step in order to convert the {\it ab-initio} electronic structure around the
Fermi level into a tight-binding-like form. Working in the Wannier
representation, the Brillouin zone is sampled on a large number of equally
spaced parallel slices oriented normal to the total magnetization. On each
slice, we find the intersections of the Fermi-surface sheets with the slice by
standard contour methods, organize these into a set of closed loops, and
compute the Berry phases of the Bloch states as they are transported around
these loops. The anomalous Hall conductivity is proportional to the sum of the
Berry phases of all the loops on all the slices. Illustrative calculations are
performed for Fe, Co and Ni.


title:
Exponential Separation of Quantum and Classical Non-Interactive
  Multi-Party Communication Complexity

abstract:
  We give the first exponential separation between quantum and classical
multi-party communication complexity in the (non-interactive) one-way and
simultaneous message passing settings.
  For every k, we demonstrate a relational communication problem between k
parties that can be solved exactly by a quantum simultaneous message passing
protocol of cost O(log n) and requires protocols of cost n^{c/k^2}, where c>0
is a constant, in the classical non-interactive one-way message passing model
with shared randomness and bounded error.
  Thus our separation of corresponding communication classes is superpolynomial
as long as k=o(\sqrt{\log n / \log\log n}) and exponential for k=O(1).


title:
Establishing the nature of companion candidates to X-ray emitting late
  B-type stars

abstract:
  The most favored interpretation for the detection of X-ray emission from late
B-type stars is that these stars have a yet undiscovered late-type companion
(or an unbound nearby late-type star) that produces the X-rays. Several faint
IR objects at (sub)-arcsecond separation from B-type stars have been uncovered
in our earlier adaptive optics imaging observations, and some of them have been
followed up with the high spatial resolution of the Chandra X-ray observatory,
pinpointing the X-ray emitter. However, firm conclusions on their nature
requires a search for spectroscopic signatures of youth. Here we report on our
recent ISAAC observations carried out in low resolution spectroscopic mode.
Equivalent widths have been used to obtain information on spectral types of the
companions. All eight X-ray emitting systems with late B-type primaries studied
contain dwarf like companions with spectral types later than A7. The only
system in the sample where the companion turns out to be of early spectral type
is not an X-ray source. These results are consistent with the assumption that
the observed X-ray emission from late B-type stars is produced by an active
pre-main sequence companion star.


title:
Shot-Noise-Limited Operation of a Fast Quantum-Point-Contact Charge
  Sensor

abstract:
  We have operated a quantum point contact (QPC) charge detector in a radio
frequency (RF) mode that allows fast charge detection in a bandwidth of tens of
megahertz. We find that the charge sensitivity of the RF-QPC is limited not by
the noise of a secondary amplifier, but by non-equilibrium noise f the QPC
itself. We have performed frequency-resolved measurements of the noise within a
10 MHz bandwidth around our carrier wave. When averaged over our bandwidth, we
find that the noise is in good agreement with the theory of photon-assisted
shot noise. Our measurements also reveal strong frequency dependence of the
noise, asymmetry with respect to the carrier wave, the appearance of sharp
local maxima that are correlated with mechanical degrees of freedom in the
sample, and noise suppression indicative of many-body physics near the 0.7
structure.


title: Reliability of temporal coding on pulse-coupled networks of oscillators

abstract:
  We study the reliability of spike output in a general class of pulse-coupled
oscillators receiving a fluctuating input. Showing that this problem is
equivalent to noise-induced synchronization between identical networks of
oscillators, we employ the phase reduction method to analytically derive the
average Lyapunov exponent of the synchronized state. We show that a transition
occurs between reliable and unreliable responses at a critical coupling
strength, which is determined through the competition between the external
input and recurrent input. To our surprise, the critical value does not depend
on intrinsic properties of oscillators.


title: Enhance synchronizability via age-based coupling

abstract:
  In this brief report, we study the synchronization of growing scale-free
networks. An asymmetrical age-based coupling method is proposed with only one
free parameter $\alpha$. Although the coupling matrix is asymmetric, our
coupling method could guarantee that all the eigenvalues are non-negative
reals. The eigneratio R will approach to 1 in the large limit of $\alpha$.


title: The Local Void is Really Empty

abstract:
  Are voids in the distribution of galaxies only places with reduced matter
density and low star formation efficiency or are they empty of matter? There is
now compelling evidence of expansion away from the Local Void at very high
velocities. The motion is most reasonably interpreted as an evacuation of the
void, which requires that the void be very large and very empty.


title:
The effect of memory on functional large deviations of infinite moving
  average processes

abstract:
  The large deviations of an infinite moving average process with exponentially
light tails are very similar to those of an i.i.d. sequence as long as the
coefficients decay fast enough. If they do not, the large deviations change
dramatically. We study this phenomenon in the context of functional large,
moderate and huge deviation principles.


title:
Singular Potentials in Quantum Mechanics and Ambiguity in the
  Self-Adjoint Hamiltonian

abstract:
  For a class of singular potentials, including the Coulomb potential (in three
and less dimensions) and $V(x) = g/x^2$ with the coefficient $g$ in a certain
range ($x$ being a space coordinate in one or more dimensions), the
corresponding Schr\"odinger operator is not automatically self-adjoint on its
natural domain. Such operators admit more than one self-adjoint domain, and the
spectrum and all physical consequences depend seriously on the self-adjoint
version chosen. The article discusses how the self-adjoint domains can be
identified in terms of a boundary condition for the asymptotic behaviour of the
wave functions around the singularity, and what physical differences emerge for
different self-adjoint versions of the Hamiltonian. The paper reviews and
interprets known results, with the intention to provide a practical guide for
all those interested in how to approach these ambiguous situations.


title:
Gauge Theory Model of the Neutrino and New Physics Beyond the Standard
  Model

abstract:
  Majorana features of neutrinos and SO(3) gauge symmetry of three families
enable us to construct a gauge model of neutrino for understanding naturally
the observed smallness of neutrino masses and the nearly tri-bimaximal neutrino
mixing when combining together with the mechanism of approximate global U(1)
family symmetry. The vacuum structure of SO(3) symmetry breaking is found to
play an important role. The mixing angle $\theta_{13}$ and CP-violating phases
governed by the vacuum of spontaneous symmetry breaking are in general non-zero
and testable experimentally at the allowed sensitivity. The model predicts the
existence of vector-like SO(3) triplet charged leptons and vector-like SO(3)
triplet Majorana neutrinos as well as SO(3) tri-triplet Higgs bosons, some of
them can be light and explored at the colliders LHC and ILC.


title:
An Improved Semi-Analytical Spherical Collapse Model for Non-linear
  Density Evolution

abstract:
  We derive a semi-analytical extension of the spherical collapse model of
structure formation that takes account of the effects of deviations from
spherical symmetry and shell crossing which are important in the non-linear
regime. Our model is designed so that it predicts a relation between the
peculiar velocity and density contrast that agrees with the results of N-body
simulations in the region where such a comparison can sensibly be made. Prior
to turnaround, when the unmodified spherical collapse model is expect to be a
good approximation, the predictions of the two models coincide almost exactly.
The effects of a late time dominating dark energy component are also taken into
account. The improved spherical collapse model is a useful tool when one
requires a good approximation not just to the evolution of the density contrast
but also its trajectory. Moreover, the analytical fitting formulae presented is
simple enough to be used anywhere where the standard spherical collapse might
be used but with the advantage that it includes a realistic model of the
effects of virialisation.


title:
Asymptotic Curvature Decay and Removal of Singularities of Bach-Flat
  Metrics

abstract:
  We prove a removal of singularities result for Bach-flat metrics in dimension
4 under the assumption of bounded L^2 norm of curvature, bounded Sobolev
constant and a volume growth bound. This result extends the removal of
singularities result for special classes of Bach-flat metrics obtained in
\cite{TVMOD}. For the proof we analyze the decay rates of solutions to the
Bach-flat equation linearized around a flat metric. This classification is used
to prove that Bach-flat cones are in fact ALE of order $\tau$ for any $\tau <
2$. This result is then used to prove the removal of singularities theorem.


title:
Milky Way Kinematics: Measurements at the Subcentral Point of the Fourth
  Quadrant

abstract:
  We use atomic hydrogen (HI) data from the Southern Galactic Plane Survey to
study the kinematics of the fourth quadrant of the Milky Way. By measuring the
terminal velocity as a function of longitude throughout the fourth Galactic
quadrant we have derived the most densely sampled rotation curve available for
the Milky Way between 3 < R < 8 kpc. We determine a new joint rotation curve
fit for the first and fourth quadrants, which can be used for kinematic
distances interior to the Solar circle. From our data we place new limits on
the peak to peak variation of streaming motions in the fourth quadrant to be
~10 km/s. We show that the shape of the average HI profile beyond the terminal
velocity is consistent with gas of three velocity dispersions, a cold component
with $\Delta v=6.3$ km/s, a warmer component with $\Delta v=12.3$ km/s and a
fast component with $\Delta v=25.9$ km/s. Examining the widths with Galactic
radius we find that the narrowest two components show little variation with
radius and their small scale fluctuations track each other very well,
suggesting that they share the same cloud-to-cloud motions. The width of the
widest component is constant until R<4 kpc, where it increases sharply.


title:
Discovery of Four Gravitationally Lensed Quasars from the Sloan Digital
  Sky Survey

abstract:
  We present the discovery of four gravitationally lensed quasars selected from
the spectroscopic quasar catalog of the Sloan Digital Sky Survey. We describe
imaging and spectroscopic follow-up observations that support the lensing
interpretation of the following four quasars: SDSS J0832+0404 (image separation
\theta=1.98", source redshift z_s=1.115, lens redshift z_l=0.659); SDSS
J1216+3529 (\theta=1.49", z_s=2.012); SDSS J1322+1052 (\theta=2.00",
z_s=1.716); and SDSS J1524+4409 (\theta=1.67", z_s=1.210, z_l=0.320). Each
system has two lensed images. We find that the fainter image component of SDSS
J0832+0404 is significantly redder than the brighter component, perhaps because
of differential reddening by the lensing galaxy. The lens potential of SDSS
J1216+3529 might be complicated by the presence of a secondary galaxy near the
main lensing galaxy.


title: Decay of massive hair on brane black hole

abstract:
  We study analytically the intermediate and late-time behaviour of the massive
scalar field in the background of static spherically symmetric brane black hole
solutions. The intermediate behavoiur of the scalar field reveals the
dependence on the field's parameter mass as well as the multiple moment l,
while the late-time behaviour has the power-law decay rate independent of those
factors.


title: Momentum transfer to small particles by aloof electron beams

abstract:
  The force exerted on nanoparticles and atomic clusters by fast passing
electrons like those employed in transmission electron microscopes are
calculated and integrated over time to yield the momentum transferred from the
electrons to the particles. Numerical results are offered for metallic and
dielectric particles of different sizes (0-500 nm in diameter) as well as for
carbon nanoclusters. Results for both linear and angular momentum transfers are
presented. For the electron beam currents commonly employed in electron
microscopes, the time-averaged forces are shown to be comparable in magnitude
to laser-induced forces in optical tweezers. This opens up the possibility to
study optically-trapped particles inside transmission electron microscopes.


title:
XMM-Newton discovery of 217 s pulsations in the brightest persistent
  supersoft X-ray source in M31

abstract:
  We report on the discovery of a periodic modulation in the bright supersoft
X-ray source XMMU J004252.5+411540 detected in the 2000-2004 XMM-Newton
observations of M31. The source exhibits X-ray pulsations with a period P~217.7
s and a quasi-sinusoidal pulse shape and pulsed fraction ~7-11%. We did not
detect statistically significant changes in the pulsation period on the time
scale of 4 years. The X-ray spectra of XMMU J004252.5+411540 are extremely soft
and can be approximated with an absorbed blackbody of temperature 62-77 eV and
a weak power law tail of photon index ~1.7-3.1 in the 0.2-3.0 keV energy band.
The X-ray properties of the source and the absence of an optical/UV counterpart
brighter than 19 mag suggest that it belongs to M31. The estimated bolometric
luminosity of the source varies between ~2e38 and ~8e38 ergs/s at 760 kpc,
depending on the choice of spectral model. The X-ray pulsations and supersoft
spectrum of XMMU J004252.5+411540 imply that it is almost certainly an
accreting white dwarf, steadily burning hydrogen-rich material on its surface.
We interpret X-ray pulsations as a signature of the strong magnetic field of
the rotating white dwarf. Assuming that the X-ray source is powered by disk
accretion, we estimate its surface field strength to be in the range 4e5 G
<B_{0}<8e6 G. XMMU J004252.5+411540 is the second supersoft X-ray source in M31
showing coherent pulsations, after the transient supersoft source XMMU
J004319.4+411758 with 865.5 s pulsation period.


title: The Yale Lar TPC

abstract:
  In this paper we give a concise description of a liquid argon time projection
chamber (LAr TPC) developed at Yale, and present results from its first
calibration run with cosmic rays.


title:
Plasmons in nearly touching metallic nanoparticles: singular response in
  the limit of touching dimers

abstract:
  The response of gold nanoparticle dimers is studied theoretically near and
beyond the limit where the particles are touching. As the particles approach
each other, a dominant dipole feature is observed that is pushed into the
infrared due to interparticle coupling and that is associated with a large
pileup of induced charge in the interparticle gap. The redshift becomes
singular as the particle separation decreases. The response weakens for very
small separation when the coupling across the interparticle gap becomes so
strong that dipolar oscillations across the pair are inhibited.
Lower-wavelength, higher-order modes show a similar separation dependence in
nearly touching dimers. After touching, singular behavior is observed through
the emergence of a new infrared absorption peak, also accompanied by huge
charge pileup at the interparticle junction, if initial interparticle-contact
is made at a single point. This new mode is distinctly different from the
lowest mode of the separated dimer. When the junction is made by contact
between flat surfaces, charge at the junction is neutralized and mode evolution
is continuous through contact. The calculated singular response explains recent
experiments on metallic nanoparticle dimers and is relevant in the design of
nanoparticle-based sensors and plasmon circuits.


title:
A Portal Analysis for the Design of a Collaborative Research Environment
  for Students and Supervisors (CRESS) within the CSCR Domain

abstract:
  In a previous paper the CSCR domain was defined. Here this is taken to the
next stage where we consider the design of a particular Collaborative Research
Environment to support Students and Supervisors CRESS. Following the CSCR
structure a preliminary design for CRESS has been established and a portal
framework analysis is undertaken in order to determine the most appropriate set
of tools for its implementation.


title: Double Boundary and Parity Doubling in Hadrons

abstract: A new mechanism for the parity doublers in hadrons is suggested.


title: Sub-Lorentzian Geometry on Anti-De Sitter Space

abstract:
  Sub-Riemannian Geometry is proved to play an important role in many
applications, e.g., Mathematical Physics and Control Theory. The simplest
example of sub-Riemannian structure is provided by the 3-D Heisenberg group.
Sub-Riemannian Geometry enjoys major differences from the Riemannian being a
generalisation of the latter at the same time, e.g., geodesics are not unique
and may be singular, the Hausdorff dimension is larger than the manifold
topological dimension. There exists a large amount of literature developing
sub-Riemannian Geometry. However, very few is known about its natural extension
to pseudo-Riemannian analogues. It is natural to begin such a study with some
low-dimensional manifolds. Based on ideas from sub-Riemannian geometry we
develop sub-Lorentzian geometry over the classical 3-D anti-de Sitter space.
Two different distributions of the tangent bundle of anti-de Sitter space yield
two different geometries: sub-Lorentzian and sub-Riemannian. It is shown that
the set of timelike and spacelike `horizontal' curves is non-empty and we study
the problem of horizontal connectivity in anti-de Sitter space. We also use
Lagrangian and Hamiltonian formalisms for both sub-Lorentzian and
sub-Riemannian geometries to find geodesics.


title:
Eriksson's numbers game on certain edge-weighted three-node cyclic
  graphs

abstract:
  The numbers game is a one-player game played on a finite simple graph with
certain ``amplitudes'' assigned to its edges and with an initial assignment of
real numbers to its nodes. The moves of the game successively transform the
numbers at the nodes using the amplitudes in a certain way. This game and its
interactions with Coxeter/Weyl group theory and Lie theory have been studied by
many authors. Following Eriksson, we allow the amplitudes on graph edges to be
certain real numbers. Games played on such graphs are ``E-games.'' We show that
for certain such three-node cyclic graphs, any numbers game will diverge when
played from an initial assignment of nonnegative real numbers not all zero.
This result is a key step in a Dynkin diagram classification (obtained
elsewhere) of all E-game graphs which meet a certain finiteness requirement.


title: Direct measurement of a pure spin current by a polarized light beam

abstract:
  The photon helicity may be mapped to a spin-1/2, whereby we put forward an
intrinsic interaction between a polarized light beam as a ``photon spin
current'' and a pure spin current in a semiconductor, which arises from the
spin-orbit coupling in valence bands as a pure relativity effect without
involving the Rashba or the Dresselhaus effect due to inversion asymmetries.
The interaction leads to circular optical birefringence, which is similar to
the Faraday rotation in magneto-optics but nevertheless involve no net
magnetization. The birefringence effect provide a direct, non-demolition
measurement of pure spin currents.