title: Functional renormalization for Bose-Einstein Condensation

abstract:
  We investigate Bose-Einstein condensation for interacting bosons at zero and
nonzero temperature. Functional renormalization provides us with a consistent
method to compute the effect of fluctuations beyond the Bogoliubov
approximation. For three dimensional dilute gases, we find an upper bound on
the scattering length a which is of the order of the microphysical scale -
typically the range of the Van der Waals interaction. In contrast to fermions
near the unitary bound, no strong interactions occur for bosons with
approximately pointlike interactions, thus explaining the high quantitative
reliability of perturbation theory for most quantities. For zero temperature we
compute the quantum phase diagram for bosonic quasiparticles with a general
dispersion relation, corresponding to an inverse microphysical propagator with
terms linear and quadratic in the frequency. We compute the temperature
dependence of the condensate and particle density n, and find for the critical
temperature T_c a deviation from the free theory, Delta T_c/T_c = 2.1 a
n^{1/3}. For the sound velocity at zero temperature we find very good agreement
with the Bogoliubov result, such that it may be used to determine the particle
density accurately.


title:
A Semi-relativistic Model for Tidal Interactions in BH-NS Coalescing
  Binaries

abstract:
  We study the tidal effects of a Kerr black hole on a neutron star in black
hole-neutron star binary systems using a semi-analytical approach which
describes the neutron star as a deformable ellipsoid. Relativistic effects on
the neutron star self-gravity are taken into account by employing a scalar
potential resulting from relativistic stellar structure equations. We calculate
quasi-equilibrium sequences of black hole-neutron star binaries, and the
critical orbital separation at which the star is disrupted by the black hole
tidal field: the latter quantity is of particular interest because when it is
greater than the radius of the innermost stable circular orbit, a short
gamma-ray burst scenario may develop.


title:
Reply to "Comment on 'Analytic and Numerical Verification of the Nernst
  Theorem for Metals'"

abstract:
  In this Reply to the preceding Comment of Klimchitskaya and Mostepanenko (cf.
also quant-ph/0703214), we summarize and maintain our position that the Drude
dispersion relation when inserted in the Lifshitz formula gives a
thermodynamically satisfactory description of the Casimir force, also in the
limiting case when the relaxation frequency goes to zero (perfect crystals).


title: Geometry and Topology of Coadjoint Orbits of Semisimple Lie Groups

abstract:
  Orbits of coadjoint representations of classical compact Lie groups have a
lot of applications. They appear in representation theory, geometrical
quantization, theory of magnetism, quantum optics etc. As geometric objects the
orbits were the subject of much study. However, they remain hard for
calculation and application. We propose simple solutions for the following
problems: an explicit parameterization of the orbit by means of a generalized
stereographic projection, obtaining a K\"{a}hlerian structure on the orbit,
introducing basis two-forms for the cohomology group of the orbit.


title: Asymptotics for the survival probability of a Rouse chain monomer

abstract:
  We study the long-time asymptotical behavior of the survival probability P_t
of a tagged monomer of an infinitely long Rouse chain in presence of two fixed
absorbing boundaries, placed at x = \pm L. Mean-square displacement of a tagged
monomer obeys \bar{X^2(t)} \sim t^{1/2} at all times, which signifies that its
dynamics is an anomalous diffusion process.
  Constructing lower and upper bounds on P_t, which have the same
time-dependence but slightly differ by numerical factors in the definition of
the characteristic relaxation time, we show that P_t is a stretched-exponential
function of time, \ln(P_t) \sim - t^{1/2}/L^2. This implies that the
distribution function of the first exit time from a fixed interval [-L,L] for
such an anomalous diffusion has all moments.


title: The ages of L dwarfs

abstract:
  We present a new method to derive the age of young (<0.7 Gyr) L dwarfs based
on their near-infrared photometry, colours, and distances. The method is based
on samples of L dwarfs belonging to the Upper Sco association (5 Myr), the
Alpha Per (85 Myr) and Pleiades (125 Myr) clusters, and the Ursa Major (400
Myr) and Hyades (625 Myr) moving groups. We apply our method to a number of
interesting objects in the literature, including a known L dwarf binary, L
dwarf companions, and spectroscopic members of the young sigma Orionis cluster.


title:
Optimization approach for the computation of magnetohydrostatic coronal
  equilibria in spherical geometry

abstract:
  Context: This paper presents a method which can be used to calculate models
of the global solar corona from observational data. Aims: We present an
optimization method for computing nonlinear magnetohydrostatic equilibria in
spherical geometry with the aim to obtain self-consistent solutions for the
coronal magnetic field, the coronal plasma density and plasma pressure using
observational data as input. Methods: Our code for the self-consistent
computation of the coronal magnetic fields and the coronal plasma solves the
non-force-free magnetohydrostatic equilibria using an optimization method.
Previous versions of the code have been used to compute non-linear force-free
coronal magnetic fields from photospheric measurements in Cartesian and
spherical geometry, and magnetostatic-equilibria in Cartesian geometry. We test
our code with the help of a known analytic 3D equilibrium solution of the
magnetohydrostatic equations. The detailed comparison between the numerical
calculations and the exact equilibrium solutions is made by using magnetic
field line plots, plots of density and pressure and some of the usual
quantitative numerical comparison measures. Results: We find that the method
reconstructs the equilibrium accurately, with residual forces of the order of
the discretisation error of the analytic solution. The correlation with the
reference solution is better than 99.9% and the magnetic energy is computed
accurately with an error of <0.1%. Conclusions: We applied the method so far to
an analytic test case. We are planning to use this method with real
observational data as input as soon as possible.


title:
The "DODO" survey I: limits on ultra-cool substellar and planetary-mass
  companions to van Maanen's star (vMa 2)

abstract:
  We report limits in the planetary-mass regime for companions around the
nearest single white dwarf to the Sun, van Maanen's star (vMa 2), from deep
J-band imaging with Gemini North and Spitzer IRAC mid-IR photometry. We find no
resolved common proper motion companions to vMa 2 at separations from 3" - 45",
at a limiting magnitude of J~23. Assuming a total age for the system of 4.1
+/-1 Gyr, and utilising the latest evolutionary models for substellar objects,
this limit is equivalent to companion masses >7 +/-1 Mjup (T~300K). Taking into
account the likely orbital evolution of very low mass companions in the
post-main sequence phase, these J-band observations effectively survey orbits
around the white dwarf progenitor from 3 - 50AU. There is no flux excess
detected in any of the complimentary Spitzer IRAC mid-IR filters. We fit a DZ
white dwarf model atmosphere to the optical BVRI, 2MASS JHK and IRAC
photometry. The best solution gives T=6030 +/- 240K, log g=8.10 +/-0.04 and,
hence, M= 0.633 +/-0.022Msun. We then place a 3sigma upper limit of 10 +/-2
Mjup on the mass of any unresolved companion in the 4.5 micron band.


title:
Evidence for collisional depolarization of the \ion{Ba}{ii}
  ${\lambda}4554$ line in the low chromosphere

abstract:
  Context. Rigorous modeling of the \ion{Ba}{ii} ${\lambda}4554$ formation is
potentially interesting since this strongly polarized line forms in the solar
chromosphere where the magnetic field is rather poorly known. Aims. To
investigate the role of isotropic collisions with neutral hydrogen in the
formation of the polarized \ion{Ba}{ii} ${\lambda}4554$ line and, thus, in the
determination of the magnetic field. Methods. Multipole relaxation and transfer
rates of the $d$ and p-states of \ion{Ba}{ii} by isotropic collisions with
neutral hydrogen are calculated. We consider a plane parallel layer of
\ion{Ba}{ii} situated at the low chromosphere and anisotropically illuminated
from below which produces linear polarization in the ${\lambda}4554$ line by
scattering processes. To compute that polarization, we solve the statistical
equilibrium equations for \ion{Ba}{ii} levels including collisions, radiation
and magnetic field effects. Results. Variation laws of the relaxation and
transfer rates with hydrogen number density $n_{\textrm {\scriptsize H}}$ and
temperature are deduced. The polarization of the ${\lambda}4554$ line is
clearly affected due to isotropic collisions with neutral hydrogen although the
collisional depolarization of its upper level $^2P_{3/2}$ is negligible. This
is because the alignment of the metastable levels $^2D_{3/2}$ and $^2D_{5/2}$
of the \ion{Ba}{ii} are vulnerable to collisions. At the height of formation of
the ${\lambda}4554$ line where $n_{\textrm {\scriptsize H}} \sim 2 \times
10^{14}$ cm$^{-3}$, we find that the neglecting of the collisions induces
inaccuracy of $\sim$ 25% on the calculation of the polarization and $\sim$ 35 %
inaccuracy on microturbulent magnetic field determination.


title: A Lorentz Invariant Phenomenological Model of Quantum Gravity

abstract:
  We consider a model of Quantum Gravity phenomenology, based on the idea that
space-time may have some unknown granular structure that respects the Lorentz
symmetry. The proposal involves non-trivial couplings of curvature to matter
fields and leads to a well defined phenomenology. In this manuscript, a brief
description of the model is presented together with some results obtained using
linearized gravity and the Newtonian limit, which could be useful when
comparing with real experiments.


title: Effect of ELF e.m. fields on metalloprotein redox-active sites

abstract:
  The peculiarity of the distribution and geometry of metallic ions in enzymes
pushed us to set the hypothesis that metallic ions in active-site act like tiny
antennas able to pick up very feeble e.m. signals. Enzymatic activity of Cu2+,
Zn2+ Superoxide Dismutase (SOD1) and Fe2+ Xanthine Oxidase (XO) has been
studied, following in vitro generation and removal of free radicals. We
observed that Superoxide radicals generation by XO is increased by a weak field
having the Larmor frequency fL of Fe2+ while the SOD1 kinetics is sensibly
reduced by exposure to a weak field having the frequency fL of Cu2+ ion.


title:
Crossover from Thermal Activation to Quantum Interlayer Transport at the
  Superconducting Transition Temperature of Bi-2212

abstract:
  We perform a detailed study of temperature, bias and doping dependance of
interlayer transport in the layered high temperature superconductor
Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$. We observe that the shape of interlayer
characteristics in underdoped crystals exhibit a remarkable crossover at the
superconducting transition temperature: from thermal activation-type at
$T>T_c$, to almost $T-$independent quantum tunneling-type, at $T<T_c$. Our data
indicates that the interlayer transport mechanism may change with doping: from
the conventional single quasiparticle tunneling in overdoped, to a
progressively increasing Cooper pair contribution in underdoped crystals.


title:
Selective Spin Injection Controlled by Electrical way in
  Ferromagnet/Quantum Dot/Semiconductor system

abstract:
  Selective and large polarization of current injected into semiconductor (SC)
is predicted in Ferromagnet (FM)/Quantum Dot (QD)/SC system by varying the gate
voltage above the Kondo temperature. In addition, spin-dependent Kondo effect
is also revealed below Kondo temperature. It is found that Kondo resonances for
up spin state is suppressed with increasing of the polarization P of the FM
lead. While the down one is enhanced. The Kondo peak for up spin is disappear
at P=1.


title:
Nucleosynthesis in novae: experimental progress in the determination of
  nuclear reaction rates

abstract:
  The sources of nuclear uncertainties in nova nucleosynthesis have been
identified using hydrodynamical nova models. Experimental efforts have followed
and significantly reduced those uncertainties. This is important for the
evaluation of nova contribution to galactic chemical evolution, gamma--ray
astronomy and possibly presolar grain studies. In particular, estimations of
expected gamma-ray fluxes are essential for the planning of observations with
existing or future satellites.


title: Galilean invariance of lattice Boltzmann models

abstract:
  It is well-known that the original lattice Boltzmann (LB) equation deviates
from the Navier-Stokes equations due to an unphysical velocity dependent
viscosity. This unphysical dependency violates the Galilean invariance and
limits the validation domain of the LB method to near incompressible flows. As
previously shown, recovery of correct transport phenomena in kinetic equations
depends on the higher hydrodynamic moments. In this Letter, we give specific
criteria for recovery of various transport coefficients. The Galilean
invariance of a general class of LB models is demonstrated via numerical
experiments.


title:
A vortex dynamics approach to the Nernst effect in fluctuating
  superconductors

abstract:
  We present a new method to study the Nernst effect and diamagetism of an
extreme type-II superconductor dominated by phase fluctuations. We work
directly with vortex variables and our method allows us to tune vortex
parameters (e.g., core energy and number of vortex species). We find that
diamagnetic response and transverse thermoelectric conductivity ($\alpha_{xy}$)
persist well above the Kosterlitz-Thouless transition temperature, and become
more pronounced as the vortex core energy is increased. However, they
\textit{weaken} as the number of internal vortex states are increased. We find
that $\alpha_{xy}$ closely tracks the magnetization $(-M/T)$ over a wide range
of parameters.


title:
An asymptotic version of Dumnicki's algorithm for linear systems in
  $\mathbb{CP}^2$

abstract:
  Using Dumnicki's approach to showing non-specialty of linear systems
consisting of plane curves with prescribed multiplicities in sufficiently
general points on $\mathbb{P}^2$ we develop an asymptotic method to determine
lower bounds for Seshadri constants of general points on $\mathbb{P}^2$. With
this method we prove the lower bound 4/13 for 10 general points on
$\mathbb{P}^2$.


title: Collisions of particles advected in random flows

abstract:
  We consider collisions of particles advected in a fluid. As already pointed
out by Smoluchowski [Z. f. physik. Chemie XCII, 129-168, (1917)], macroscopic
motion of the fluid can significantly enhance the frequency of collisions
between the suspended particles. This effect was invoked by Saffman and Turner
[J. Fluid Mech. 1, 16-30, (1956)] to estimate collision rates of small water
droplets in turbulent rain clouds, the macroscopic motion being caused by
turbulence. Here we show that the Saffman-Turner theory is unsatisfactory
because it describes an initial transient only. The reason for this failure is
that the local flow in the vicinity of a particle is treated as if it were a
steady hyperbolic flow, whereas in reality it must fluctuate. We derive exact
expressions for the steady-state collision rate for particles suspended in
rapidly fluctuating random flows and compute how this steady state is
approached. For incompressible flows, the Saffman-Turner expression is an upper
bound.


title: Cold atom dynamics in non-Abelian gauge fields

abstract:
  The dynamics of ultracold neutral atoms subject to a non-Abelian gauge field
is investigated. In particular we analyze in detail a simple experimental
scheme to achieve a constant, but non-Abelian gauge field, and discuss in the
frame of this gauge field the non-Abelian Aharanov-Bohm effect. In the last
part of this paper, we discuss intrinsic non-Abelian effects in the dynamics of
cold atomic wavepackets.


title:
Approximate Unitary Equivalence in Simple C^*-algebras of Tracial Rank
  One

abstract:
  Let $C$ be a unital AH-algebra and let $A$ be a unital separable simple
C*-algebra with tracial rank no more than one. Suppose that $\phi, \psi: C\to
A$ are two unital monomorphisms. With some restriction on $C,$ we show that
$\phi$ and $\psi$ are approximately unitarily equivalent if and only if
  [\phi]=[\psi] in KL(C,A)
  \tau\circ \phi=\tau\circ \psi for all tracial states of A and
  \phi^{\ddag}=\psi^{\ddag}, here \phi^{\ddag} and \psi^{\ddag} are
homomorphisms from $U(C)/CU(C)\to U(A)/CU(A) induced by \phi and \psi,
respectively, and where CU(C) and CU(A) are closures of the subgroup generated
by commutators of the unitary groups of C and B.


title: Maser emission in planetary nebulae

abstract:
  Stars at the top of the asymptotic giant branch (AGB) can exhibit maser
emission from molecules like SiO, H2O and OH. As the star evolves to the
planetary nebula phase, mass-loss stops and ionization of the envelope begins,
making the masers disappear progressively. The OH masers in PNe can be present
in the envelope for periods of ~1000 years but the water masers can survive
only hundreds of years. Then, water maser emission is not expected in planetary
nebulae! We discuss the unambiguous detection of water maser emission in two
planetary nebulae: K 3-35 and IRAS 17347-3139.


title: A Truthful Mechanism for Offline Ad Slot Scheduling

abstract:
  We consider the "Offline Ad Slot Scheduling" problem, where advertisers must
be scheduled to "sponsored search" slots during a given period of time.
Advertisers specify a budget constraint, as well as a maximum cost per click,
and may not be assigned to more than one slot for a particular search.
  We give a truthful mechanism under the utility model where bidders try to
maximize their clicks, subject to their personal constraints. In addition, we
show that the revenue-maximizing mechanism is not truthful, but has a Nash
equilibrium whose outcome is identical to our mechanism. As far as we can tell,
this is the first treatment of sponsored search that directly incorporates both
multiple slots and budget constraints into an analysis of incentives.
  Our mechanism employs a descending-price auction that maintains a solution to
a certain machine scheduling problem whose job lengths depend on the price, and
hence is variable over the auction. The price stops when the set of bidders
that can afford that price pack exactly into a block of ad slots, at which
point the mechanism allocates that block and continues on the remaining slots.
To prove our result on the equilibrium of the revenue-maximizing mechanism, we
first show that a greedy algorithm suffices to solve the revenue-maximizing
linear program; we then use this insight to prove that bidders allocated in the
same block of our mechanism have no incentive to deviate from bidding the fixed
price of that block.


title: Exact linear hydrodynamics from the Boltzmann equation

abstract:
  Exact (to all orders in Knudsen number) equations of linear hydrodynamics are
derived from the Boltzmann kinetic equation with the Bhatnagar-Gross-Krook
collision integral. The exact hydrodynamic equations are cast in a form which
allows us to immediately prove their hyperbolicity, stability, and existence of
an H-theorem.


title: Structure and Evolution of the Opacity of Spiral Disks

abstract:
  The opacity of a spiral disk due to dust absorption influences every
measurement we make of it in the UV and optical. Two separate techniques
directly measure the total absorption by dust in the disk: calibrated distant
galaxy counts and overlapping galaxy pairs. The main results from both so far
are a semi-transparent disk with more opaque arms, and a relation between
surface brightness and disk opacity. In the Spitzer era, SED models of spiral
disks add a new perspective on the role of dust in spiral disks. Combined with
the overall opacity from galaxy counts, they yield a typical optical depth of
the dusty ISM clouds: 0.4 that implies a size of $\sim$ 60 pc. Work on galaxy
counts is currently ongoing on the ACS fields of M51, M101 and M81. Occulting
galaxies offer the possibility of probing the history of disk opacity from
higher redshift pairs. Evolution in disk opacity could influence distance
measurements (SN1a, Tully-Fisher relation). Here, we present first results from
spectroscopically selected occulting pairs in the SDSS. The redshift range for
this sample is limited, but does offer a first insight into disk opacity
evolution as well as a reference for higher redshift measurements. Spiral disk
opacity has not undergone significant evolution since z=0.2. HST imaging would
help disentangle the effects of spiral arms in these pairs. Many more
mixed-morphology types are being identified in SDSS by the GalaxyZoo project.
The occulting galaxy technique can be pushed to a redshift of 1 using many
pairs identified in the imaging campaigns with HST (DEEP2, GEMS, GOODS,
COSMOS).


title: P-values for classification

abstract:
  Let $(X,Y)$ be a random variable consisting of an observed feature vector
$X\in \mathcal{X}$ and an unobserved class label $Y\in \{1,2,...,L\}$ with
unknown joint distribution. In addition, let $\mathcal{D}$ be a training data
set consisting of $n$ completely observed independent copies of $(X,Y)$. Usual
classification procedures provide point predictors (classifiers)
$\widehat{Y}(X,\mathcal{D})$ of $Y$ or estimate the conditional distribution of
$Y$ given $X$. In order to quantify the certainty of classifying $X$ we propose
to construct for each $\theta =1,2,...,L$ a p-value
$\pi_{\theta}(X,\mathcal{D})$ for the null hypothesis that $Y=\theta$, treating
$Y$ temporarily as a fixed parameter. In other words, the point predictor
$\widehat{Y}(X,\mathcal{D})$ is replaced with a prediction region for $Y$ with
a certain confidence. We argue that (i) this approach is advantageous over
traditional approaches and (ii) any reasonable classifier can be modified to
yield nonparametric p-values. We discuss issues such as optimality, single use
and multiple use validity, as well as computational and graphical aspects.


title: Landau levels of cold atoms in non-Abelian gauge fields

abstract:
  The Landau levels of cold atomic gases in non-Abelian gauge fields are
analyzed. In particular we identify effects on the energy spectrum and density
distribution which are purely due to the non-Abelian character of the fields.
We investigate in detail non-Abelian generalizations of both the Landau and the
symmetric gauge. Finally, we discuss how these non-Abelian Landau and symmetric
gauges may be generated by means of realistically feasible lasers in a tripod
scheme.


title: Geometry of Orbifolded Supersymmetric Lattice Gauge Theories

abstract:
  We prove that the prescription for construction of supersymmetric lattice
gauge theories by orbifolding and deconstruction directly leads to Catterall's
geometrical discretization scheme in general. These two prescriptions always
give the same lattice discretizations when applied to theories of p-form
fields. We also show that the geometrical discretization scheme can be applied
to more general theories.


title: The Effect of 53 micron IR Radiation on 18 cm OH Megamaser Emission

abstract:
  OH megamasers (OHMs) emit primarily in the main lines at 1667 and 1665 MHz,
and differ from their Galactic counterparts due to their immense luminosities,
large linewidths and 1667/1665 MHz flux ratios, which are always greater than
one. We find that these maser properties result from strong 53 micron radiative
pumping combined with line overlap effects caused by turbulent linewidths of
about 20 km/s; pumping calculations that do not include line overlap are
unreliable. A minimum dust temperature of about 45 K is needed for inversion,
and maximum maser efficiency occurs for dust temperatures in the range 80 - 140
K. We find that warmer dust can support inversion at lower IR luminosities, in
agreement with observations. Our results are in good agreement with a clumpy
model of OHMs, with clouds sizes about 1 pc and OH column densities about 5e16
cm^2, that is able to explain both the diffuse and compact emission observed
for OHMs. We suggest that all OH main line masers may be pumped by far-IR
radiation, with the major differences between OHMs and Galactic OH masers
caused by differences in linewidth produced by line overlap. Small Galactic
maser linewidths tend to produce stronger 1665 MHz emission. The large OHM
linewidths lead to inverted ground state transitions having approximately the
same excitation temperature, producing 1667/1665 MHz flux ratios greater than
one and weak satellite line emission. Finally, the small observed ratio of
pumping radiation to dense molecular gas, as traced by HCN and HCO$^+$, is a
possible reason for the lack of OH megamaser emission in NGC 6240.


title: Spitzer's View of Edge-on Spirals

abstract:
  Edge-on spiral galaxies offer a unique perspective on disks. One can
accurately determine the height distribution of stars and ISM and the
line-of-sight integration allows for the study of faint structures. The Spitzer
IRAC camera is an ideal instrument to study both the ISM and stellar structure
in nearby galaxies; two of its channels trace the old stellar disk with little
extinction and the 8 micron channel is dominated by the smallest dust grains
(Polycyclic Aromatic Hydrocarbons, PAHs).
  Dalcanton et al. (2004) probed the link between the appearance of dust lanes
and the disk stability. In a sample of bulge-less disks they show how in
massive disks the ISM collapses into the characteristic thin dust lane. Less
massive disks are gravitationally stable and their dust morphology is
fractured. The transition occurs at 120 km/s for bulgeless disks.
  Here we report on our results of our Spitzer/IRAC survey of nearby edge-on
spirals and its first results on the NIR Tully-Fischer relation, and ISM disk
stability.


title: Irreducible Boolean Functions

abstract:
  This paper is a contribution to the study of a quasi-order on the set
$\Omega$ of Boolean functions, the \emph{simple minor} quasi-order. We look at
the join-irreducible members of the resulting poset $\tilde{\Omega}$. Using a
two-way correspondence between Boolean functions and hypergraphs,
join-irreducibility translates into a combinatorial property of hypergraphs. We
observe that among Steiner systems, those which yield join-irreducible members
of $\tilde{\Omega}$ are the -2-monomorphic Steiner systems. We also describe
the graphs which correspond to join-irreducible members of $\tilde{\Omega}$.


title:
The changing milliarcsecond radio morphology of the gamma-ray binary LS
  5039

abstract:
  Context. LS 5039 is one of the few TeV emitting X-ray binaries detected so
far. The powering source of its multiwavelength emission can be accretion in a
microquasar scenario or wind interaction in a young nonaccreting pulsar
scenario.
  Aims. To present new high-resolution radio images and compare them with the
expected behavior in the different scenarios.
  Methods. We analyze Very Long Baseline Array (VLBA) radio observations that
provide morphological and astrometric information at milliarcsecond scales.
  Results. We detect a changing morphology between two images obtained five
days apart. In both runs there is a core component with a constant flux
density, and an elongated emission with a position angle (PA) that changes by
12+/-3 degrees between both runs. The source is nearly symmetric in the first
run and asymmetric in the second one. The astrometric results are not
conclusive.
  Conclusions. A simple and shockless microquasar scenario cannot easily
explain the observed changes in morphology. An interpretation within the young
nonaccreting pulsar scenario requires the inclination of the binary system to
be very close to the upper limit imposed by the absence of X-ray eclipses.


title:
Summary Of Four Generalized Exponential Models (GEM) For Continuous
  Probability Distributions

abstract:
  Four new probability models are derived which generalize the common
univariate continuous distributions. Classical distributional measures are
derived from Hoel, et al., Introduction to Probability Theory, 1971. Measures
include probability density function, moments generating function, cumulative
distribution function,derivatives, inverse distributions, skewness, kurtosis,
change of variable distributions, log distributions. Maximum likelihood
estimation technique is briefly outlined. Appendices describe applications.
Errata/addenda sheet included.


title:
The power law for the Buffon needle probability of the four-corner
  Cantor set

abstract:
  Let $C_n$ be the $n$-th generation in the construction of the middle-half
Cantor set. The Cartesian square $K_n$ of $C_n$ consists of $4^n$ squares of
side-length $4^{-n}$. The chance that a long needle thrown at random in the
unit square will meet $K_n$ is essentially the average length of the
projections of $K_n$, also known as the Favard length of $K_n$. A classical
theorem of Besicovitch implies that the Favard length of $K_n$ tends to zero.
It is still an open problem to determine its exact rate of decay. Until
recently, the only explicit upper bound was $\exp(- c\log_* n)$, due to Peres
and Solomyak. ($\log_* n$ is the number of times one needs to take log to
obtain a number less than 1 starting from $n$). We obtain a power law bound by
combining analytic and combinatorial ideas.


title: Trapping molecules on a chip in traveling potential wells

abstract:
  A microstructured array of over 1200 electrodes on a substrate has been
configured to generate an array of local minima of electric field strength with
a periodicity of $120 \mu$m about $25 \mu$m above the substrate. By applying
sinusoidally varying potentials to the electrodes, these minima can be made to
move smoothly along the array. Polar molecules in low field seeking quantum
states can be trapped in these traveling potential wells. This is
experimentally demonstrated by transporting metastable CO molecules in 30 mK
deep wells that move at constant velocities above the substrate.


title: Physics of rotation in stellar models

abstract:
  In these lecture notes, we present the equations presently used in stellar
interior models in order to compute the effects of axial rotation. We discuss
the hypotheses made. We suggest that the effects of rotation might play a key
role at low metallicity.


title:
Synchronizing discrete-time neutrally stable linear systems via
  partial-state coupling

abstract:
  A basic result in synchronization of linear systems via output coupling is
presented. For identical discrete-time linear systems that are detectable from
their outputs and neutrally stable, it is shown that a linear output feedback
law exists under which the coupled systems globally asymptotically synchronize
for all fixed connected (asymmetrical) network topologies. An algorithm is
provided to compute such feedback law based on individual system parameters. A
dual problem is also presented and solved.


title: Fourier optics for polymeric substrates and coating textures analysis

abstract:
  Several devices for substrate texture detection based on diffractive optics,
for paper, textiles and non-wovens have been proposed in the past for direct
inspection during the production processes. In spite of the presence of devices
totally based on image processing, the use of diffractive optics cannot be
considered surpassed for many reasons. Compared with image processing
procedures, it is less sensitive to vibrations and does not suffer from the
presence of ambient light. Based on transmitted light, it can give information
on changes in refractive indexes, thickness variation and surface conditions.
We study the use of optical Fourier spectrum to identify textures of polymer
films. As the power spectrum reveals, the texture is seldom homogeneous. Here
we report investigation on several substrates and on thin ink coatings on
substrate. Role of bulk and surface conditions is analysed.


title:
Silicon Vertex Tracker for PHENIX Upgrade at RHIC: Capabilities and
  Detector Technology

abstract:
  From the wealth of data obtained from the first three years of RHIC
operation, the four RHIC experiments, BRAHMS, PHENIX, PHOBOS and STAR, have
concluded that a high density partonic matter is formed at central Au+Au
collisions at 200 GeV. The research focus now shifts from initial discovery to
a detailed exploration of partonic matter. Particles carrying heavy flavor,
i.e. charm or beauty quarks, are powerful tool for study the properties of the
hot and dense medium created in high-energy nuclear collisions at RHIC. At the
relatively low transverse momentum region, the collective motion of the heavy
flavor will be a sensitive signal for the thermalization of light flavors. An
upgrade of RHIC (RHIC-II) is intended for the second half of the decade, with a
luminosity increase to about 20-40 times the design value of 8x1026 cm-2 s-1
for Au+Au, and 2x1032 cm-2 s-1 for polarized proton beams. The PHENIX
collaboration plans to upgrade its experiment to exploit with an enhanced
detector new physics then in reach. For this purpose, we are constructing the
Silicon Vertex Tracker (VTX). The VTX detector will provide us the tool to
measure new physics observables that are not accessible at the present RHIC or
available only with very limited accuracy. The VTX detector consists of four
layers of barrel detectors located in the region of pseudorapidity |eta| < 1.2
and covers almost 2 azimuthal angle. The pseudorapidity is defined as eta =
-ln[tan(/2)], where is the emission angle relative to the beam axis. In this
paper, we will provide details of the physics capability added to PHENIX by the
new central silicon vertex tracker, the status of the project, including
technology choices used in the design, performance of individual silicon sensor
and silicon detector prototype.


title:
q-Deformed Statistical-Mechanical Property in the Dynamics of
  Trajectories en route to the Feigenbaum Attractor

abstract:
  We demonstrate that the dynamics towards and within the Feigenbaum attractor
combine to form a q-deformed statistical-mechanical construction. The rate at
which ensemble trajectories converge to the attractor (and to the repellor) is
described by a q-entropy obtained from a partition function generated by
summing distances between neighboring positions of the attractor. The values of
the q-indices involved are given by the unimodal map universal constants, while
the thermodynamic structure is closely related to that formerly developed for
multifractals. As an essential component in our demonstration we expose, at a
previously unknown level of detail, the features of the dynamics of
trajectories that either evolve towards the Feigenbaum attractor or are
captured by its matching repellor. The dynamical properties of the family of
periodic superstable cycles in unimodal maps are seen to be key ingredients for
the comprehension of the discrete scale invariance features present at the
period-doubling transition to chaos. We make clear the dynamical origin of the
anomalous thermodynamic framework existing at the Feigenbaum attractor.


title:
Unitarity Bounds for Gauged Axionic Interactions and the Green-Schwarz
  Mechanism

abstract:
  We analyze the effective actions of anomalous models in which a
four-dimensional version of the Green-Schwarz mechanism is invoked for the
cancellation of the anomalies, and we compare it with those models in which
gauge invariance is restored by the presence of a Wess-Zumino term. Some issues
concerning an apparent violation of unitarity of the mechanism, which requires
Dolgov-Zakharov poles, are carefully examined, using a class of amplitudes
studied in the past by Bouchiat-Iliopoulos-Meyer (BIM), and elaborating on
previous studies. In the Wess-Zumino case we determine explicitly the unitarity
bound using a realistic model of intersecting branes (the Madrid model) by
studying the corresponding BIM amplitudes. This is shown to depend
significantly on the St\"uckelberg mass and on the coupling of the extra
anomalous gauge bosons and allows one to identify Standard-Model-like regions
(which are anomaly-free) from regions where the growth of certain amplitudes is
dominated by the anomaly, separated by an inflection point which could be
studied at the LHC. The bound can even be around 5-10 TeV's for a $Z'$ mass
around 1 TeV and varies sensitively with the anomalous coupling. The results
for the WZ case are quite general and apply to all the models in which an
axion-like interaction is introduced as a generalization of the Peccei-Quinn
mechanism, with a gauged axion.


title: Classical stability of a homogeneous, anisotropic inflating space-time

abstract:
  We study the classical stability of an anisotropic space-time seeded by a
spacelike, fixed norm, dynamical vector field in a vacuum-energy-dominated
inflationary era. It serves as a model for breaking isotropy during the
inflationary era. We find that, for a range of parameters, the linear
differential equations for small perturbations about the background do not have
a growing mode. We also examine the energy of fluctuations about this
background in flat-space. If the kinetic terms for the vector field do not take
the form of a field strength tensor squared then there is a negative energy
mode and the background is unstable. For the case where the kinetic term is of
the form of a field strength tensor squared we show that perturbations about
the background have positive energy at lowest order.


title:
The Topology of Foliations Formed by the Generic K-Orbits of a Subclass
  of the Indecomposable MD5-Groups

abstract:
  The present paper is a continuation of [13], [14] of the authors.
Specifically, the paper considers the MD5-foliations associated to connected
and simply connected MD5-groups such that their Lie algebras have 4-dimensional
commutative derived ideal. In the paper, we give the topological classification
of all considered MD5-foliations. A description of these foliations by certain
fibrations or suitable actions of $\mathbb{R}^{2}$ and the Connes' C*-algebras
of the foliations which come from fibrations are also given in the paper.


title: Rotating trapped Bose-Einstein condensates

abstract:
  After reviewing the ideal Bose-Einstein gas in a box and in a harmonic trap,
I discuss the effect of interactions on the formation of a Bose-Einstein
condensate (BEC), along with the dynamics of small-amplitude perturbations (the
Bogoliubov equations). When the condensate rotates with angular velocity Omega,
one or several vortices nucleate, with many observable consequences. With more
rapid rotation, the vortices form a dense triangular array, and the collective
behavior of these vortices has additional experimental implications. For Omega
near the radial trap frequency omega_perp, the lowest-Landau-level
approximation becomes applicable, providing a simple picture of such rapidly
rotating condensates. Eventually, as Omega approaches omega_perp, the rotating
dilute gas is expected to undergo a quantum phase transition from a superfluid
to various highly correlated (nonsuperfluid) states analogous to those familiar
from the fractional quantum Hall effect for electrons in a strong perpendicular
magnetic field.


title: Mould Calculus for Hamiltonian Vector Fields

abstract:
  We present the general framework of \'Ecalle's moulds in the case of
linearization of a formal vector field without and within resonances. We
enlighten the power of moulds by their universality, and calculability. We
modify then \'Ecalle's technique to fit in the seek of a formal normal form of
a Hamiltonian vector field in cartesian coordinates. We prove that mould
calculus can also produce successive canonical transformations to bring a
Hamiltonian vector field into a normal form. We then prove a Kolmogorov theorem
on Hamiltonian vector fields near a diophantine torus in action-angle
coordinates using moulds techniques.


title:
Am\'elioration de l'\'etude de l'\'etude de l'humidit\'e de sols par
  radiom\'etrie. Caract\'erisation et mod\'elisation di\'electriques de profils
  g\'eologiques

abstract:
  The surface soil moisture is a key variable to describe the exchange of water
and energy between the land and the atmosphere. In hydrology, and meteorology,
the amount of water in the upper soil layers permits (0-5 cm from the surface)
the evaluation of the relationship between the real evaporation and the
potential evaporation of the bare soil. It is also possible to determine the
distribution of rainfall or other variables such as hydraulic conductivity.
Studies have shown that microwave sensors could be used to scan the surface
soil moisture. The solution choose by the team associated with the SMOS mission
(Soil Moisture and Ocean Salinity) is to use a radiometer (1.4 GHz) to identify
soil microwave emissions . The measurements are made on the site of CESBIO in
Toulouse where a 1.4 GHz radiometer is installed . The effect of vegetation
cover, soil temperatures, snow cover, topography or moisture variations have an
important role in the broadcast microwave surface. Other parameters such as the
presence of inclusions in the ground (holes, stones), or soil texture can also
disrupt measurements. The aim of the work that we present in this paper is to
develop a numerical model to simulate complex geological structures. This model
must take into account all parameters that can affect the equivalent
permittivity measured by the radiometer (surface, moisture variation ,...
inclusions). The purpose of this model is to calculate the equivalent
permittivity of these geological structures in order to be able to associate
with each radiometer measurement an equivalent moisture.


title: Profinite completion and double-dual : isomorphisms and counter-examples

abstract:
  We define, for any group $G$, finite approximations ; with this tool, we give
a new presentation of the profinite completion $\hat{\pi} : G \to \hat{G}$ of
an abtract group $G$. We then prove the following theorem : if $k$ is a finite
prime field and if $V$ is a $k$-vector space, then, there is a natural
isomorphism between $\hat{V}$ (for the underlying additive group structure) and
the additive group of the double-dual $V^{**}$. This theorem gives
counter-examples concerning the iterated profinite completions of a group.
These phenomena don't occur in the topological case.


title: Multi-phase matching in the Grover algorithm

abstract:
  Phase matching has been studied for the Grover algorithm as a way of
enhancing the efficiency of the quantum search. Recently Li and Li found that a
particular form of phase matching yields, with a single Grover operation, a
success probability greater than 25/27 for finding the equal-amplitude
superposition of marked states when the fraction of the marked states stored in
a database state is greater than 1/3. Although this single operation eliminates
the oscillations of the success probability that occur with multiple Grover
operations, the latter oscillations reappear with multiple iterations of Li and
Li's phase matching. In this paper we introduce a multi-phase matching subject
to a certain matching rule by which we can obtain a multiple Grover operation
that with only a few iterations yields a success probability that is almost
constant and unity over a wide range of the fraction of marked items. As an
example we show that a multi-phase operation with six iterations yields a
success probability between 99.8% and 100% for a fraction of marked states of
1/10 or larger.


title: Semilinear Schr\"odinger Flows on Hyperbolic Spaces: Scattering in H^1

abstract:
  We prove global well-posedness and scattering in $H^1$ for the defocusing
nonlinear Schr\"{o}dinger equations \begin{equation*} \begin{cases}
&(i\partial_t+\Delta_\g)u=u|u|^{2\sigma}; &u(0)=\phi, \end{cases}
\end{equation*} on the hyperbolic spaces $\H^d$, $d\geq 2$, for exponents
$\sigma\in(0,2/(d-2))$. The main unexpected conclusion is scattering to linear
solutions in the case of small exponents $\sigma$; for comparison, on Euclidean
spaces scattering in $H^1$ is not known for any exponent $\sigma\in(1/d,2/d]$
and is known to fail for $\sigma\in(0,1/d]$. Our main ingredients are certain
noneuclidean global in time Strichartz estimates and noneuclidean Morawetz
inequalities.


title: The Z^d Alpern multi-tower theorem for rectangles: a tiling approach

abstract:
  We provide a proof of the Alpern multi-tower theorem for Z^d actions. We
reformulate the theorem as a problem of measurably tiling orbits of a Z^d
action by a collection of rectangles whose corresponding sides have no
non-trivial common divisors. We associate to such a collection of rectangles a
special family of generalized domino tilings. We then identify an intrinsic
dynamic property of these tilings, viewed as symbolic dynamical systems, which
allows for a multi-tower decomposition.


title: On Besov regularity of Brownian motions in infinite dimensions

abstract:
  We extend to the vector-valued situation some earlier work of Ciesielski and
Roynette on the Besov regularity of the paths of the classical Brownian motion.
We also consider a Brownian motion as a Besov space valued random variable. It
turns out that a Brownian motion, in this interpretation, is a Gaussian random
variable with some pathological properties. We prove estimates for the first
moment of the Besov norm of a Brownian motion. To obtain such results we
estimate expressions of the form $\E \sup_{n\geq 1}\|\xi_n\|$, where the
$\xi_n$ are independent centered Gaussian random variables with values in a
Banach space. Using isoperimetric inequalities we obtain two-sided inequalities
in terms of the first moments and the weak variances of $\xi_n$.


title:
$C^1$-Generic Symplectic Diffeomorphisms: Partial Hyperbolicity and Zero
  Center Lyapunov Exponents

abstract:
  We prove that if $f$ is a $C^1$-generic symplectic diffeomorphism then the
Oseledets splitting along almost every orbit is either trivial or partially
hyperbolic. In addition, if $f$ is not Anosov then all the exponents in the
center bundle vanish. This establishes in full a result announced by R.
Ma\~{n}\'{e} in the ICM 1983. The main technical novelty is a probabilistic
method for the construction of perturbations, using random walks.


title: Symmetry fingerprints of a benzene single-electron transistor

abstract:
  The interplay between Coulomb interaction and orbital symmetry produces
specific transport characteristics in molecular single electron transistors
(SET) that can be considered as the fingerprints of the contacted molecule.
Specifically we predict, for a benzene SET, selective conductance suppression
and the appearance of negative differential conductance when changing the
contacts from para to meta configuration. Both effects originate from
destructive interference in transport involving states with orbital degeneracy.


title:
Spacetime foam: from entropy and holography to infinite statistics and
  nonlocality

abstract:
  Due to quantum fluctuations, spacetime is foamy on small scales. The degree
of foaminess is found to be consistent with holography, a principle prefigured
in the physics of black hole entropy. It has bearing on the ultimate accuracies
of clocks and measurements and the physics of quantum computation. Consistent
with existing archived data on active galactic nuclei from the Hubble Space
Telescope, the application of the holographic spacetime foam model to cosmology
requires the existence of dark energy which, we argue, is composed of an
enormous number of inert "particles" of extremely long wavelength. We suggest
that these "particles" obey infinite statistics in which all representations of
the particle permutation group can occur, and that the nonlocality present in
systems obeying infinite statistics may be related to the nonlocality present
in holographic theories. We also propose to detect spacetime foam by looking
for halos in the images of distant quasars, and argue that it does not modify
the GZK cutoff in the ultra-high energy cosmic ray spectrum and its
contributions to time-of-flight differences of high energy gamma rays from
distant GRB are too small to be detectable.


title: A New, Bright, Short-Period, Emission Line Binary in Ophiuchus

abstract:
  The 11th magnitude star LS IV -08 3 has been classified previously as an OB
star in the Luminous Stars survey, or alternatively as a hot subdwarf. It is
actually a binary star. We present spectroscopy, spectroscopic orbital
elements, and time series photometry, from observations made at the Kitt Peak
National Observatory 2.1m, Steward Observatory 2.3m, MDM Observatory 1.3m and
2.4m, Hobby-Eberly 9.2m, and Michigan State University 0.6m telescopes. The
star exhibits emission of varying strength in the cores of H and He I
absorption lines. Emission is also present at 4686 Angstroms (He II) and near
4640/4650 Angstroms (N III/C III). Time-series spectroscopy collected from 2005
July to 2007 June shows coherent, periodic radial velocity variations of the
H-alpha line, which we interpret as orbital motion with a period of
0.1952894(10) days. High-resolution spectra show that there are two emission
components, one broad and one narrow, moving in antiphase, as might arise from
an accretion disk and the irradiated face of the mass donor star. Less
coherent, low-amplitude photometric variability is also present on a timescale
similar to the orbital period. Diffuse interstellar bands indicate considerable
reddening, which however is consistent with a distance of ~100-200 pc. The star
is the likely counterpart of a weak ROSAT X-ray source, whose properties are
consistent with accretion in a cataclysmic variable (CV) binary system. We
classify LS IV -08 3 as a new member of the UX UMa subclass of CV stars.


title: Vortex Splitting in Subcritical Nonlinear Schrodinger Equation

abstract:
  Vortices and axisymmetric vortex rings are considered in the framework of the
subcritical nonlinear Schrodinger equations. The higher order nonlinearity
present in such systems models many-body interactions in superfluid systems and
allows one to study the effects of negative pressure on vortex dynamics. We
find the critical pressure for which the straight-line vortex becomes unstable
to radial expansion of the core. The energy of the straight-line vortices and
energy, impulse and velocity of vortex rings are calculated. The effect of a
varying pressure on the vortex core is studied. It is shown that under the
action of the periodically varying pressure field a vortex ring may split into
many vortex rings and the conditions for which this happens are elucidated.
These processes are also relevant to experiments in Bose-Einstein condensates
where the strength and the sign of two-body interactions can be changed via
Feshbach resonance.


title: Cosmology and Cosmogony in a Cyclic Universe

abstract:
  In this paper we discuss the properties of the quasi-steady state
cosmological model (QSSC) developed in 1993 in its role as a cyclic model of
the universe driven by a negative energy scalar field. We discuss the origin of
such a scalar field in the primary creation process first described by F. Hoyle
and J. V. Narlikar forty years ago. It is shown that the creation processes
which takes place in the nuclei of galaxies are closely linked to the high
energy and explosive phenomena, which are commonly observed in galaxies at all
redshifts.
  The cyclic nature of the universe provides a natural link between the places
of origin of the microwave background radiation (arising in hydrogen burning in
stars), and the origin of the lightest nuclei (H, D, He$^3$ and He$^4$). It
also allows us to relate the large scale cyclic properties of the universe to
events taking place in the nuclei of galaxies. Observational evidence shows
that ejection of matter and energy from these centers in the form of compact
objects, gas and relativistic particles is responsible for the population of
quasi-stellar objects (QSOs) and gamma-ray burst sources in the universe.
  In the later parts of the paper we briefly discuss the major unsolved
problems of this integrated cosmological and cosmogonical scheme. These are the
understanding of the origin of the intrinsic redshifts, and the periodicities
in the redshift distribution of the QSOs.


title: Radio Wavelength Transients: Current and Emerging Prospects

abstract:
  Known classes of radio wavelength transients range from the nearby--stellar
flares and radio pulsars--to the distant Universe--\gamma-ray burst afterglows.
Hypothesized classes of radio transients include analogs of known objects,
e.g., extrasolar planets emitting Jovian-like radio bursts and giant-pulse
emitting pulsars in other galaxies, to the exotic, prompt emission from
\gamma-ray bursts, evaporating black holes, and transmitters from other
civilizations. A number of instruments and facilities are either under
construction or in early observational stages and are slated to become
available in the next few years. With a combination of wide fields of view and
wavelength agility, the detection and study of radio transients will improve
immensely.


title:
The Early Spectra of Eta Carinae 1892 to 1941 and the Onset of Its High
  Excitation Emission Spectrum

abstract:
  The observed behavior of eta Car from 1860 to 1940 has not been considered in
most recent accounts, nor has it been explained in any quantitative model. We
have used modern digital processing techniques to examine Harvard
objective-prism spectra made from 1892 to 1941. Relatively high-excitation He I
4471 and [Fe III] 4658 emission, conspicuous today, were weak and perhaps
absent throughout those years. Feast et al. noted this qualitative fact for
other pre-1920 spectra, but we quantify it and extend it to a time only three
years before Gaviola's first observations of the high-excitation features.
Evidently the supply of helium-ionizing photons(lambda < 504A) grew rapidly
between 1941 and 1944. The apparent scarcity of such far-UV radiation before
1944 is difficult to explain in models that employ a hot massive secondary
star,} because no feasible dense wind or obscuration by dust would have hidden
the photoionization caused by the proposed companion during most of its orbital
period. We also discuss the qualitative near-constancy of the spectrum from
1900 to 1940, and eta Car's photometric and spectroscopic transition between
1940 and 1953.


title: Mapping the Cosmological Expansion

abstract:
  The ability to map the cosmological expansion has developed enormously,
spurred by the turning point one decade ago of the discovery of cosmic
acceleration. The standard model of cosmology has shifted from a matter
dominated, standard gravity, decelerating expansion to the present search for
the origin of acceleration in the cosmic expansion. We present a wide ranging
review of the tools, challenges, and physical interpretations. The tools
include direct measures of cosmic scales through Type Ia supernova luminosity
distances, and angular distance scales of baryon acoustic oscillation and
cosmic microwave background density perturbations, as well as indirect probes
such as the effect of cosmic expansion on the growth of matter density
fluctuations. Accurate mapping of the expansion requires understanding of
systematic uncertainties in both the measurements and the theoretical
framework, but the result will give important clues to the nature of the
physics behind accelerating expansion and to the fate of the universe.


title:
A Search for sub-km KBOs with the Method of Serendipitous Stellar
  Occultations

abstract:
  The results of a search for sub-km Kuiper Belt Objects (KBOs) with the method
of serendipitous stellar occultations are reported. Photometric time series
were obtained on the 1.8m telescope at the Dominion Astrophysical Observatory
(DAO) in Victoria, BC, and were analyzed for the presence of occultation
events. Observations were performed at 40 Hz and included a total of 5.0
star-hours for target stars in the ecliptic open cluster M35 (beta=0.9deg), and
2.1 star-hours for control stars in the off-ecliptic open cluster M34
(beta=25.7deg). To evaluate the recovery fraction of the analysis method, and
thereby determine the limiting detectable size, artificial occultation events
were added to simulated time series (1/f scintillation-like power-spectra), and
to the real data. No viable candidate occultation events were detected. This
limits the cumulative surface density of KBOs to 3.5e10 deg^{-2} (95%
confidence) for KBOs brighter than m_R=35.3 (larger than ~860m in diameter,
assuming a geometric albedo of 0.04 and a distance of 40 AU). An evaluation of
TNO occultations reported in the literature suggests that they are unlikely to
be genuine, and an overall 95%-confidence upper limit on the surface density of
2.8e9 deg^{-2} is obtained for KBOs brighter than m_R=35 (larger than ~1 km in
diameter, assuming a geometric albedo of 0.04 and a distance of 40 AU) when all
existing surveys are combined.


title: Collective cyclotron motion of the relativistic plasma in graphene

abstract:
  We present a theory of the finite temperature thermo-electric response
functions of graphene, in the hydrodynamic regime induced by electron-electron
collisions. In moderate magnetic fields, the Dirac particles undergo a
collective cyclotron motion with a temperature-dependent relativistic cyclotron
frequency proportional to the net charge density of the Dirac plasma. In
contrast to the undamped cyclotron pole in Galilean-invariant systems (Kohn's
theorem), here there is a finite damping induced by collisions between the
counter-propagating particles and holes. This cyclotron motion shows up as a
damped pole in the frequency dependent conductivities, and should be readily
detectable in microwave measurements at room temperature. We also discuss the
large Nernst effect to be expected in graphene.


title: H-alpha Kinematics of the SINGS Nearby Galaxies Survey. II

abstract:
  This is the second part of an H-alpha kinematics follow-up survey of the
Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim of this program
is to shed new light on the role of baryons and their kinematics and on the
dark/luminous matter relation in the star forming regions of galaxies, in
relation with studies at other wavelengths. The data for 37 galaxies are
presented. The observations were made using Fabry-Perot interferometry with the
photon-counting camera FaNTOmM on 4 different telescopes, namely the
Canada-France-Hawaii 3.6m, the ESO La Silla 3.6m, the William Herschel 4.2m,
and the Observatoire du mont Megantic 1.6m telescopes. The velocity fields are
computed using custom IDL routines designed for an optimal use of the data. The
kinematical parameters and rotation curves are derived using the GIPSY
software. It is shown that non-circular motions associated with galactic bars
affect the kinematical parameters fitting and the velocity gradient of the
rotation curves. This leads to incorrect determinations of the baryonic and
dark matter distributions in the mass models derived from those rotation
curves.


title: On the Absorption and Redistribution of Energy in Irradiated Planets

abstract:
  We present a sequence of toy models for irradiated planet atmospheres, in
which the effects of geometry and energy redistribution are modelled
self-consistently. We use separate but coupled grey atmosphere models to treat
the ingoing stellar irradiation and outgoing planetary reradiation. We
investigate how observed quantities such as full phase secondary eclipses and
orbital phase curves depend on various important parameters, such as the depth
at which irradiation is absorbed and the depth at which energy is
redistributed. We also compare our results to the more detailed radiative
transfer models in the literature, in order to understand how those map onto
the toy model parameter space. Such an approach can prove complementary to more
detailed calculations, in that they demonstrate, in a simple way, how the
solutions change depending on where, and how, energy redistribution occurs. As
an example of the value of such models, we demonstrate how energy
redistribution and temperature equilibration at moderate optical depths can
lead to temperature inversions in the planetary atmosphere, which may be of
some relevance to recent observational findings.


title: A Model to Explain Varying $\Lambda$, $G$ and $\sigma^2$ Simultaneously

abstract:
  Models with varying cosmical parameters, which were earlier regarded
constant, are getting attention. However, different models are usually invoked
to explain the evolution of different parameters. We argue that whatever
physical process is responsible for the evolution of one parameter, should also
be responsible for the evolution of others. This means that the different
parameters are coupled together somehow. Based on this guiding principle, we
investigate a Bianchi type I model with variable $\Lambda$ and $G$, in which
$\Lambda$, $G$ and the shear parameter $\sigma^2$, all are coupled. It is
interesting that the resulting model reduces to the FLRW model for large $t$
with $G$ approaching a constant.


title: Where is the Radiation Edge in Magnetized Black Hole Accretion discs?

abstract:
  General Relativistic (GR) Magnetohydrodynamic (MHD) simulations of black hole
accretion find significant magnetic stresses near and inside the innermost
stable circular orbit (ISCO), suggesting that such flows could radiate in a
manner noticeably different from the prediction of the standard model, which
assumes that there are no stresses in that region. We provide estimates of how
phenomenologically interesting parameters like the ``radiation edge", the
innermost ring of the disc from which substantial thermal radiation escapes to
infinity, may be altered by stresses near the ISCO. These estimates are based
on data from a large number of three-dimensional GRMHD simulations combined
with GR ray-tracing. For slowly spinning black holes ($a/M<0.9$), the radiation
edge lies well inside where the standard model predicts, particularly when the
system is viewed at high inclination. For more rapidly spinning black holes,
the contrast is smaller. At fixed total luminosity, the characteristic
temperature of the accretion flow increases between a factor of $1.2-2.4$ over
that predicted by the standard model, whilst at fixed mass accretion rate,
there is a corresponding enhancement of the accretion luminosity which may be
anywhere from tens of percent to order unity. When all these considerations are
combined, we find that, for fixed black hole mass, luminosity, and inclination
angle, our uncertainty in the characteristic temperature of the radiation
reaching distant observers due to uncertainty in dissipation profile (around a
factor of 3) is {\it greater} than the uncertainty due to a complete lack of
knowledge of the black hole's spin (around a factor of 2) and furthermore that
spin estimates based on the stress-free inner boundary condition provide an
upper limit to $a/M$.


title: A blind test of photometric redshifts on ground-based data

abstract:
  Aims. We analyse the relative performance of different photo-z codes in blind
applications to ground-based data. Methods. We tested the codes on imaging
datasets with different depths and filter coverages and compared the results to
large spectroscopic catalogues. The photo-z error behaviour was analysed to
select cleaner subsamples with more secure photo-z estimates. We consider
Hyperz, BPZ, and the code used in the CADIS, COMBO-17, and HIROCS surveys.
Results. The photo-z error estimates of the three codes do not correlate
tightly with the accuracy of the photo-z's. While very large errors sometimes
indicate a true catastrophic photo-z failure, smaller errors are usually not
meaningful. For any given dataset, we find significant differences in redshift
accuracy and outlier rates between the different codes when compared to
spectroscopic redshifts. However, different codes excel in different regimes.
The agreement between different sets of photo-z's is better for the subsample
with secure spectroscopic redshifts than for the whole catalogue. Conclusions.
Running today's photo-z codes on well-calibrated ground-based data can lead to
reasonable accuracy. The actual performance on a given dataset is largely
dependent on the template choice and on realistic instrumental response curves.
It would be desirable to improve the photo-z error estimation for future
applications so as to get a better handle on rejecting objects with grossly
inaccurate photo-z's. The secure spectroscopic subsamples commonly used for
assessments of photo-z accuracy may be biased toward objects for which the
photo-z's are easier to estimate than for a complete flux-limited sample,
resulting in very optimistic estimates. (abridged)


title: High-redshift blazar identification for Swift J1656.3-3302

abstract:
  We report on the high-redshift blazar identification of a new gamma-ray
source, Swift J1656.3-3302, detected with the BAT imager onboard the Swift
satellite and the IBIS instrument on the INTEGRAL satellite. Follow-up optical
spectroscopy has allowed us to identify the counterpart as an R-band 19 mag
source that shows broad Lyman-alpha, Si IV, He II, C IV, and C III] emission
lines at redshift z = 2.40+-0.01. Spectral evolution is observed in X-rays when
the INTEGRAL/IBIS data are compared to the Swift/BAT results, with the spectrum
steepening when the source gets fainter. The 0.7-200 keV X-ray continuum,
observed with Swift/XRT and INTEGRAL/IBIS, shows the power law shape typical of
radio loud (broad emission line) active galactic nuclei (with a photon index
around 1.6) and a hint of spectral curvature below 2 keV, possibly due to
intrinsic absorption (N_H about 7e22 cm-2) local to the source. Alternatively,
a slope change (of about 1 in terms of photon index) around 2.7 keV can
describe the X-ray spectrum equally well. At this redshift, the observed 20-100
keV luminosity of the source is about 1e48 erg s-1 (assuming isotropic
emission), making Swift J1656.3-3302 one of the most X-ray luminous blazars.
This source is yet another example of a distant gamma-ray loud quasar
discovered above 20 keV. It is also the farthest object, among the previously
unidentified INTEGRAL sources, whose nature has been determined a posteriori
through optical spectroscopy.


title: Breaking an Abelian gauge symmetry near a black hole horizon

abstract:
  I argue that coupling the Abelian Higgs model to gravity plus a negative
cosmological constant leads to black holes which spontaneously break the gauge
invariance via a charged scalar condensate slightly outside their horizon. This
suggests that black holes can superconduct.


title:
Towards a Spectral Technique for Determining Material Geometry Around
  Evolved Stars: Application to HD 179821

abstract:
  HD 179821 is an evolved star of unknown progenitor mass range (either
post-Asymptotic Giant Branch or post-Red Supergiant) exhibiting a double peaked
spectral energy distribution (SED) with a sharp rise from $\sim8-20$ $\mu$m.
Such features have been associated with ejected dust shells or inwardly
truncated circumstellar discs. In order to compare SEDs from both systems, we
employ a spherically symmetric radiative transfer code and compare it to a
radiative, inwardly truncated disc code. As a case study, we model the
broad-band SED of HD 179821 using both codes. Shortward of 40 $\mu$m, we find
that both models produce equivalent fits to the data. However, longward of 40
$\mu$m, the radial density distribution and corresponding broad range of disc
temperatures produce excess emission above our spherically symmetric solutions
and the observations. For HD 179821, our best fit consists of a $T_{eff}=7000$
K central source characterized by $\tau_V\sim1.95$ and surrounded by a
radiatively driven, spherically symmetric dust shell. The extinction of the
central source reddens the broad-band colours so that they resemble a
$T_{eff}=5750$ K photosphere. We believe that HD 179821 contains a hotter
central star than previously thought. Our results provide an initial step
towards a technique to distinguish geometric differences from spectral
modeling.


title: Generalized quandle polynomials

abstract:
  We define a family of generalizations of the two-variable quandle polynomial.
These polynomial invariants generalize in a natural way to eight-variable
polynomial invariants of finite biquandles. We use these polynomials to define
a family of link invariants which further generalize the quandle counting
invariant.


title: Analysing tax evasion dynamics via the Ising model

abstract:
  We develop a model of tax evasion based on the Ising model. We augment the
model using an appropriate enforcement mechanism that may allow policy makers
to curb tax evasion. With a certain probability tax evaders are subject to an
audit. If they get caught they behave honestly for a certain number of periods.
Simulating the model for a range of parameter combinations, we show that tax
evasion may be controlled effectively by using punishment as an enforcement
mechanism.


title:
Self-Similarity and Universality in Rayleigh-Taylor, Boussinesq
  Turbulence

abstract:
  We report and discuss case study simulations of the Rayleigh-Taylor
instability in the Boussinesq, incompressible regime developed to turbulence.
Our main focus is on a statistical analysis of density and velocity
fluctuations inside of the already developed and growing in size mixing zone.
Novel observations reported in the manuscript concern self-similarity of the
velocity and density fluctuations spectra inside of the mixing zone snapshot,
independence of the spectra of the horizontal slice level, and universality
showing itself in a virtual independence of the internal structure of the
mixing zone, measured in the re-scaled spatial units, of the initial interface
perturbations.


title: The Identifiability of Covarion Models in Phylogenetics

abstract:
  Covarion models of character evolution describe inhomogeneities in
substitution processes through time. In phylogenetics, such models are used to
describe changing functional constraints or selection regimes during the
evolution of biological sequences. In this work the identifiability of such
models for generic parameters on a known phylogenetic tree is established,
provided the number of covarion classes does not exceed the size of the
observable state space. `Generic parameters' as used here means all parameters
except possibly those in a set of measure zero within the parameter space.
Combined with earlier results, this implies both the tree and generic numerical
parameters are identifiable if the number of classes is strictly smaller than
the number of observable states.


title:
Crossing symmetry and phenomenological widths in effective Lagrangian
  models of the pion photoproduction process

abstract:
  We investigate the importance of crossing symmetry in effective field models
and the effects of phenomenological nucleon resonance widths on the
paradigmatic case of pion photoproduction. We use reaction models containing
four star resonances up to 1.8 Gev ($\Delta$(1232), N(1440), N(1520), N(1535),
$\Delta$(1620), N(1650), $\Delta$(1700), and N(1720)) with different
prescriptions for crossed terms and widths, to fit the latest world database on
pion photoproduction. We compare $\chi^2$ results from selected multipoles and
fits. The $\chi^2$ is highly dependent on the fulfillment of crossing symmetry
and the inclusion of $u$ channels.


title: Casimir energy in spherical cavities

abstract:
  We calculate the Casimir energy at spherical cavities within a host made up
of an arbitrary material described by a possibly dispersive and lossy
dielectric response. To that end, we add to the coherent optical response a
contribution that takes account of the incoherent radiation emitted by the host
in order to guarantee the detailed balance required to keep the system at
thermodynamic equilibrium in the presence of dissipation. The resulting
boundary conditions allow a conventional quantum mechanical treatment of the
radiation within the cavity from which we obtain the contribution of the cavity
walls to the density of states, and from it, the thermodynamic properties of
the system. The contribution of the cavity to the energy diverges as it
incorporates the interaction energy between neighbor atoms in a continuum
description. The change in the energy of an atom situated at the center of the
cavity due to its interaction with the fluctuating cavity field is however
finite. We evaluate the latter for a simple case.


title:
Determination of the b-quark mass and nonperturbative parameters in
  semileptonic and radiative penguin decays at BABAR

abstract:
  Knowing the mass of the b-quark is essential to the study of the structure
and decays of B mesons as well as to future tests of the Higgs mechanism of
mass generation. We present recent preliminary measurements of the b-quark mass
and related nonperturbative parameters from moments of kinematic distributions
in charmed and charmless semileptonic and radiative penguin B decays. Their
determination from charmless semileptonic B decays is the first measurement in
this mode. The data were collected by the BABAR detector at the PEP-II
asymmetric-energy e+e- -collider at the Stanford Linear Accelerator Center at a
center-of-momentum energy of 10.58 GeV.


title:
Polynomial-time quantum algorithm for the simulation of chemical
  dynamics

abstract:
  The computational cost of exact methods for quantum simulation using
classical computers grows exponentially with system size. As a consequence,
these techniques can only be applied to small systems. By contrast, we
demonstrate that quantum computers could exactly simulate chemical reactions in
polynomial time. Our algorithm uses the split-operator approach and explicitly
simulates all electron-nuclear and inter-electronic interactions in quadratic
time. Surprisingly, this treatment is not only more accurate than the
Born-Oppenheimer approximation, but faster and more efficient as well, for all
reactions with more than about four atoms. This is the case even though the
entire electronic wavefunction is propagated on a grid with appropriately short
timesteps. Although the preparation and measurement of arbitrary states on a
quantum computer is inefficient, here we demonstrate how to prepare states of
chemical interest efficiently. We also show how to efficiently obtain
chemically relevant observables, such as state-to-state transition
probabilities and thermal reaction rates. Quantum computers using these
techniques could outperform current classical computers with one hundred
qubits.


title: The minimum rank problem over finite fields

abstract:
  The structure of all graphs having minimum rank at most k over a finite field
with q elements is characterized for any possible k and q. A strong connection
between this characterization and polarities of projective geometries is
explained. Using this connection, a few results in the minimum rank problem are
derived by applying some known results from projective geometry.


title: The divisibility modulo 24 of Kloosterman sums on $GF(2^m)$, $m$ even

abstract:
  In a recent work by Charpin, Helleseth, and Zinoviev Kloosterman sums $K(a)$
over a finite field $\F_{2^m}$ were evaluated modulo 24 in the case $m$ odd,
and the number of those $a$ giving the same value for $K(a)$ modulo 24 was
given. In this paper the same is done in the case $m$ even. The key techniques
used in this paper are different from those used in the aforementioned work. In
particular, we exploit recent results on the number of irreducible polynomials
with prescribed coefficients.


title: Contraction of matchgate tensor networks on non-planar graphs

abstract:
  A tensor network is a product of tensors associated with vertices of some
graph $G$ such that every edge of $G$ represents a summation (contraction) over
a matching pair of indexes. It was shown recently by Valiant, Cai, and
Choudhary that tensor networks can be efficiently contracted on planar graphs
if components of every tensor obey a system of quadratic equations known as
matchgate identities. Such tensors are referred to as matchgate tensors. The
present paper provides an alternative approach to contraction of matchgate
tensor networks that easily extends to non-planar graphs. Specifically, it is
shown that a matchgate tensor network on a graph $G$ of genus $g$ with $n$
vertices can be contracted in time $T=poly(n) + 2^{2g} O(m^3)$ where $m$ is the
minimum number of edges one has to remove from $G$ in order to make it planar.
Our approach makes use of anticommuting (Grassmann) variables and Gaussian
integrals.


title:
Forward Neutral Pion Transverse Single Spin Asymmetries in p+p
  Collisions at \sqrt{s}=200 GeV

abstract:
  We report precision measurements of the Feynman-x dependence, and first
measurements of the transverse momentum dependence, of transverse single spin
asymmetries for the production of \pi^0 mesons from polarized proton collisions
at \sqrt{s}=200 GeV. The x_F dependence of the results is in fair agreement
with perturbative QCD model calculations that identify orbital motion of quarks
and gluons within the proton as the origin of the spin effects. Results for the
p_T dependence at fixed x_F are not consistent with pQCD-based calculations.


title:
A new concept of strong controllability via the Schur complement in
  adaptive tracking

abstract:
  We propose a new concept of strong controllability associated with the Schur
complement of a suitable limiting matrix. This concept allows us to extend the
previous results associated with multidimensional ARX models. On the one hand,
we carry out a sharp analysis of the almost sure convergence for both least
squares and weighted least squares algorithms. On the other hand, we also
provide a central limit theorem and a law of iterated logarithm for these two
stochastic algorithms. Our asymptotic results are illustrated by numerical
simulations.


title: Dimensions of compact invariant sets of some expanding maps

abstract:
  We study the Hausdorff dimension and measures of full Hausdorff dimension for
a compact invariant set of an expanding nonconformal map on the torus given by
an integer-valued diagonal matrix. The Hausdorff dimension of a "general
Sierpinski carpet" was found by McMullen and Bedford and the uniqueness of the
measure of full Hausdorff dimension in some cases was proved by Kenyon and
Peres. We extend these results by using compensation functions to study a
general Sierpinski carpet represented by a shift of finite type. We give some
conditions under which a general Sierpinski carpet has a unique measure of full
Hausdorff dimension, and study the properties of the unique measure.


title: E_7(7) on the Light Cone

abstract:
  We use the Cremmer-Julia E_7(7) non-linear symmetry of N=8 Supergravity to
derive its order $\kappa^2$ on-shell Hamiltonian in terms of one chiral
light-cone superfield. By requiring that E_7(7) commute with the super-Poincare
group, we deduce to lowest non-trivial order in $\kappa$, the light cone E_7(7)
transformations of all fields of the theory, including the graviton. We then
derive the dynamical supersymmetry transformation to order $\kappa^2$, and
express the Hamiltonian as a quadratic form in the chiral superfield.


title: Transformed Dissipation in Superconducting Quantum Circuits

abstract:
  Superconducting quantum circuits must be designed carefully to avoid
dissipation from coupling to external control circuitry. Here we introduce the
concept of current transformation to quantify coupling to the environment. We
test this theory with an experimentally-determined impedance transformation of
$\sim 10^5$ and find quantitative agreement better than a factor of 2 between
this transformation and the reduced lifetime of a phase qubit coupled to a
tunable transformer. Higher-order corrections from quantum fluctuations are
also calculated with this theory, but found not to limit the qubit lifetime. We
also illustrate how this simple connection between current and impedance
transformation can be used to rule out dissipation sources in experimental
qubit systems.


title: Crystal-field level inversion in lightly Mn-doped Sr3Ru2O7

abstract:
  Sr3(Ru1-xMnx)2O7, in which 4d-Ru is substituted by the more localized 3d-Mn,
is studied by x-ray dichroism and spin-resolved density functional theory. We
find that Mn impurities do not exhibit the same 4+ valence of Ru, but act as 3+
acceptors; the extra eg electron occupies the in-plane 3dx2-y2 orbital instead
of the expected out-of-plane 3d3z2-r2. We propose that the 3d-4d interplay, via
the ligand oxygen orbitals, is responsible for this crystal-field level
inversion and the material's transition to an antiferromagnetic, possibly
orbitally-ordered, low-temperature state.


title:
Using integrals of squares of certain real-valued special functions to
  prove that the P\'olya \Xi^*(z) function, the functions K_{iz}(a), a > 0, and
  some other entire functions have only real zeros

abstract:
  Analogous to the use of sums of squares of certain real-valued special
functions to prove the reality of the zeros of the Bessel functions J_\alpha(z)
when \alpha \ge -1, confluent hypergeometric functions {}_0F_1(c; z) when c > 0
or 0 > c > -1, Laguerre polynomials L_n^\alpha(z) when \alpha \ge -2, Jacobi
polynomials P_n^{(\alpha,\beta)}(z) when \alpha \ge -1 and \beta \ge -1, and
some other entire special functions considered in G. Gasper [Using sums of
squares to prove that certain entire functions have only real zeros, in Fourier
Analysis: Analytic and Geometric Aspects, W. O. Bray, P. S. Milojevi\'c and C.
V. Stanojevi\'c, eds., Marcel Dekker, Inc., 1994, 171--186.], integrals of
squares of certain real-valued special functions are used to prove the reality
of the zeros of the P\'olya \Xi^*(z) function, the K_{iz}(a) functions when a >
0, and some other entire functions.


title:
Finding Ground States of Sherrington-Kirkpatrick Spin Glasses with
  Hierarchical BOA and Genetic Algorithms

abstract:
  This study focuses on the problem of finding ground states of random
instances of the Sherrington-Kirkpatrick (SK) spin-glass model with Gaussian
couplings. While the ground states of SK spin-glass instances can be obtained
with branch and bound, the computational complexity of branch and bound yields
instances of not more than about 90 spins. We describe several approaches based
on the hierarchical Bayesian optimization algorithm (hBOA) to reliably
identifying ground states of SK instances intractable with branch and bound,
and present a broad range of empirical results on such problem instances. We
argue that the proposed methodology holds a big promise for reliably solving
large SK spin-glass instances to optimality with practical time complexity. The
proposed approaches to identifying global optima reliably can also be applied
to other problems and they can be used with many other evolutionary algorithms.
Performance of hBOA is compared to that of the genetic algorithm with two
common crossover operators.


title: Anomalous gtt couplings in the Littlest Higgs Model with T-parity

abstract:
  In this work we calculate the leading electroweak (EW) corrections to the
anomalous $gt\bar{t}$ coupling in the Littlest Higgs model with T-parity (LHT),
by applying the Goldstone boson equivalence theorem. In the LHT model, such
electroweak corrections arise from the loop diagrams of heavy fermions and the
``would-be'' Goldstone bosons. We further examine the EW corrections in the top
quark pair production via the quark annihilation process at the LHC. The
negative EW corrections in the Standard Model are partially canceled by the
positive EW corrections from the loops of the new heavy particles, and the
latter dominates in the large invariant mass of the top quark pair.


title:
Nonlinear intraband tunneling of BEC in a cubic three-dimensional
  lattice

abstract:
  The intra-band tunneling of a Bose-Einstein condensate between three
degenerate high-symmetry X-points of the Brillouin zone of a cubic optical
lattice is studied in the quantum regime by reduction to a three-mode model.
The mean-field approximation of the deduced model is described. Compared to the
previously reported two-dimensional (2D) case [Phys. Rev. A 75, 063628 (2007)],
which is reducible to the two-mode model, in the case under consideration there
exist a number of new stable stationary atomic distributions between the
X-points and a new critical lattice parameter. The quantum collapses and
revivals of the atomic population dynamics are absent for the experimentally
realizable time span. The 2D stationary configurations, embedded into the 3D
lattice, turn out to be always unstable, while existence of a stable 1D
distribution, where all atoms populate only one X-state, may serve as a
starting point in the experimental study of the nonlinear tunneling in the 3D
lattice.


title: Taste symmetry breaking with HYP-smeared staggered fermions

abstract:
  We study the impact of hypercubic (HYP) smearing on the size of taste
breaking for staggered fermions, comparing to unimproved and to asqtad-improved
staggered fermions. As in previous studies, we find a substantial reduction in
taste-breaking compared to unimproved staggered fermions (by a factor of 4-7 on
lattices with spacing $a\approx 0.1 $fm). In addition, we observe that
discretization effects of next-to-leading order in the chiral expansion (${\cal
O}(a^2 p^2)$) are markedly reduced by HYP smearing. Compared to asqtad valence
fermions, we find that taste-breaking in the pion spectrum is reduced by a
factor of 2.5-3, down to a level comparable to the expected size of generic
${\cal O}(a^2)$ effects. Our results suggest that, once one reaches a lattice
spacing of $a\approx 0.09 $fm, taste-breaking will be small enough after HYP
smearing that one can use a modified power counting in which ${\cal O}(a^2) \ll
{\cal O}(p^2)$, simplify fitting to phenomenologically interesting quantities.


title: Strategic Execution in the Presence of an Uninformed Arbitrageur

abstract:
  We consider a trader who aims to liquidate a large position in the presence
of an arbitrageur who hopes to profit from the trader's activity. The
arbitrageur is uncertain about the trader's position and learns from observed
price fluctuations. This is a dynamic game with asymmetric information. We
present an algorithm for computing perfect Bayesian equilibrium behavior and
conduct numerical experiments. Our results demonstrate that the trader's
strategy differs significantly from one that would be optimal in the absence of
the arbitrageur. In particular, the trader must balance the conflicting desires
of minimizing price impact and minimizing information that is signaled through
trading. Accounting for information signaling and the presence of strategic
adversaries can greatly reduce execution costs.


title: Eikonal Methods in AdS/CFT: BFKL Pomeron at Weak Coupling

abstract:
  We consider correlators of N=4 super Yang Mills of the form A ~ < O_1 O_2
O*_1 O*_2 >, where the operators O_1 and O_2 are scalar primaries. In
particular, we analyze this correlator in the planar limit and in a Lorentzian
regime corresponding to high energy interactions in AdS. The planar amplitude
is dominated by a Regge pole whose nature varies as a function of the 't Hooft
coupling g^2. At large g, the pole corresponds to graviton exchange in AdS,
whereas at weak g, the pole is that of the hard perturbative BFKL pomeron. We
concentrate on the weak coupling regime and analyze pomeron exchange directly
in position space. The analysis relies heavily on the conformal symmetry of the
transverse space E^2 and of its holographic dual hyperbolic space H_3,
describing with an unified language, both the weak and strong 't Hooft coupling
regimes. In particular, the form of the impact factors is highly constrained in
position space by conformal invariance. Finally, the analysis suggests a
possible AdS eikonal resummation of multi-pomeron exchanges implementing AdS
unitarity, which differs from the usual 4-dimensional eikonal exponentiation.
Relations to violations of 4-dimensional unitarity at high energy and to the
onset of nonlinear effects and gluon saturation become immediate questions for
future research.


title:
Quantum-classical correspondence in entanglement production: Entropy and
  classical tori

abstract:
  We analyze the connections between entanglement dynamics and classical
trajectories in a semiclassi-cal regime for two systems: A pair of coupled
oscillators and the Jaynes-Cummings model. We find that entanglement production
depends on classical invariant tori and such phenomenon is closely related to
the power spectra of classical trajectories. Classical power spectrum with a
larger number of frequency com-ponents corresponds to larger entanglement. We
introduce a frequency entropy to describe the classical frequency distribution,
and find that there is good correspondence between the classical frequency
entro-pies and the maximum von Neumann entropies.


title:
Nonlinear tunneling of BEC in an optical lattice: signatures of quantum
  collapse and revival

abstract:
  Quantum theory of the intraband resonant tunneling of a Bose-Einstein
condensate loaded in a twodimensional optical lattice is considered. It is
shown that the phenomena of quantum collapse and revival can be observed in the
fully quantum problem. The mean-field limit of the theory is analyzed using the
WKB approximation for discrete equations, establishing in this way a direct
connection between the two approaches conventionally used in very different
physical contexts. More specifically we show that there exist two different
regimes of tunneling and study dependence of quantum collapse and revival on
the number of condensed atoms.


title: The Palomar-Quest Digital Synoptic Sky Survey

abstract:
  We describe briefly the Palomar-Quest (PQ) digital synoptic sky survey,
including its parameters, data processing, status, and plans. Exploration of
the time domain is now the central scientific and technological focus of the
survey. To this end, we have developed a real-time pipeline for detection of
transient sources. We describe some of the early results, and lessons learned
which may be useful for other, similar projects, and time-domain astronomy in
general. Finally, we discuss some issues and challenges posed by the real-time
analysis and scientific exploitation of massive data streams from modern
synoptic sky surveys.


title: Locality and stability of the cascades of two-dimensional turbulence

abstract:
  We investigate and clarify the notion of locality as it pertains to the
cascades of two-dimensional turbulence. The mathematical framework underlying
our analysis is the infinite system of balance equations that govern the
generalized unfused structure functions, first introduced by L'vov and
Procaccia. As a point of departure we use a revised version of the system of
hypotheses that was proposed by Frisch for three-dimensional turbulence. We
show that both the enstrophy cascade and the inverse energy cascade are local
in the sense of non-perturbative statistical locality. We also investigate the
stability conditions for both cascades. We have shown that statistical
stability with respect to forcing applies unconditionally for the inverse
energy cascade. For the enstrophy cascade, statistical stability requires
large-scale dissipation and a vanishing downscale energy dissipation. A careful
discussion of the subtle notion of locality is given at the end of the paper.


title: Classification of arrayCGH data using a fused SVM

abstract:
  Motivation: Array-based comparative genomic hybridization (arrayCGH) has
recently become a popular tool to identify DNA copy number variations along the
genome. These profiles are starting to be used as markers to improve prognosis
or diagnosis of cancer, which implies that methods for automated supervised
classification of arrayCGH data are needed. Like gene expression profiles,
arrayCGH profiles are characterized by a large number of variables usually
measured on a limited number of samples. However, arrayCGH profiles have a
particular structure of correlations between variables, due to the spatial
organization of BACs along the genome. This suggests that classical
classification methods, often based on the selection of a small number of
discriminative features, may not be the most accurate methods and may not
produce easily interpretable prediction rules.
  Results: We propose a new method for supervised classification of arrayCGH
data. The method is a variant of support vector machine (SVM) that incorporates
the biological specificities of DNA copy number variations along the genome as
prior knowledge. The resulting classifier is a sparse linear classifier based
on a limited number of regions automatically selected on the chromosomes,
leading to easy interpretation and identification of discriminative regions of
the genome. We test this method on three classification problems for bladder
and uveal cancer, involving both diagnosis and prognosis. We demonstrate that
the introduction of the new prior on the classifier leads not only to more
accurate predictions, but also to the identification of known and new regions
of interest in the genome.
  Availability: All data and algorithms are publicly available.


title: The tri-pentagonal number theorem and related identities

abstract:
  I revisit an automated proof of Andrews' pentagonal number theorem found by
Riese. I uncover a simple polynomial identity hidden behind his proof. I
explain how to use this identity to prove Andrews' result along with a variety
of new formulas of similar type. I reveal an interesting relation between the
tri-pentagonal theorem and items (19), (20), (94), (98) on the celebrated
Slater list. Finally, I establish a new infinite family of multiple series
identities.


title: An analogue of the Magnus problem for associative algebras

abstract:
  We prove an analogue of the Magnus theorem for associative algebras without
unity over arbitrary fields. Namely, if an algebra is given by n+k generators
and k relations and has an n-element system of generators, then this algebra is
a free algebra of rank n.


title: A partial $A_\infty$-structure on the cohomology of $C_n\times C_m$

abstract:
  Suppose $k$ is a field of characteristic 2, and $n,m\geq 4$ powers of 2. Then
the $A_\infty$-structure of the group cohomology algebras $H^*(C_n,k)$ and
$H^*(C_m,k)$ are well known. We give results characterizing an
$A_\infty$-structure on $H^*(C_n\times C_m,k)$ including limits on
non-vanishing low-arity operations and an infinite family of non-vanishing
higher operations.


title: The conjugacy problem for two by two matrices over polynomial rings

abstract:
  We give an effective solution of the conjugacy problem for two by two
matrices over the polynomial ring in one variable over a finite field.


title: Electrical control of magnon propagation in multiferroic BiFeO3 films

abstract:
  The spin wave spectra of multiferroic BiFeO3 films is calculated using a
phenomenological Landau theory that includes magnetostatic effects. The lowest
frequency magnon dispersion is shown to be quite sensitive to the angle between
spin wave propagation vector and the Neel moment. Since electrical switching of
the Neel moment has recently been demonstrated in this material, the
sensitivity of the magnon dispersion permits direct electrical switching of
spin wave propagation. This effect can be used to construct spin wave logical
gates without current pulses, potentially allowing reduced power dissipation
per logical operation.


title: Graphs of relations and Hilbert series

abstract:
  We are discussing certain combinatorial and counting problems related to
quadratic algebras. First we give examples which confirm the Anick conjecture
on the minimal Hilbert series for algebras given by n generators and n(n-1)/2
relations for n less or equal then 7. Then we investigate combinatorial
structure of colored graph associated to relations of RIT algebra. Precise
descriptions of graphs (maps) corresponding to algebras with maximal Hilbert
series are given in certain cases. As a consequence it turns out, for example,
that RIT algebra may have a maximal Hilbert series only if components of the
graph associated to each color are pairwise 2-isomorphic.


title:
Genesis of d'Alembert's paradox and analytical elaboration of the drag
  problem

abstract:
  We show that the issue of the drag exerted by an incompressible fluid on a
body in uniform motion has played a major role in the early development of
fluid dynamics. In 1745 Euler came close, technically, to proving the vanishing
of the drag for a body of arbitrary shape; for this he exploited and
significantly extended existing ideas on decomposing the flow into thin
fillets; he did not however have a correct picture of the global structure of
the flow around a body. Borda in 1766 showed that the principle of live forces
implied the vanishing of the drag and should thus be inapplicable to the
problem. After having at first refused the possibility of a vanishing drag,
d'Alembert in 1768 established the paradox, but only for bodies with a
head-tail symmetry. A full understanding of the paradox, as due to the neglect
of viscous forces, had to wait until the work of Saint-Venant in 1846.


title: Weighted pluripotential theory on complex K\"{a}hler manifolds

abstract:
  We introduce a weighted version of the pluripotential theory on complex
K\"{a}hler manifolds developed by Guedj and Zeriahi. We give the appropriate
definition of a weighted pluricomplex Green function, its basic properties and
consider its behaviour under holomorphic maps. We also establish a
generalization of Siciak's H-principle.


title: Stacks similar to the stack of perverse sheaves

abstract:
  We introduce, on a topological space X, a class of stacks of abelian
categories we call "stacks of type P." This class of stacks includes the stack
of perverse sheaves (of any perversity, constructible with respect to a fixed
stratification), and is singled out by fairly innocuous axioms. We show that
some basic structure theory for perverse sheaves holds for a general stack of
type P: such a stack is locally equivalent to a MacPherson-Vilonen
construction, and under certain connectedness conditions its category of global
objects is equivalent to the category of modules over a finite-dimensional
algebra. To prove these results we develop a rudimentary tilting formalism for
stacks of type P -- another sense in which these stacks are "similar to stacks
of perverse sheaves."