title: The Lotus-Eater Attack

abstract:
  Many protocols for distributed and peer-to-peer systems have the feature that
nodes will stop providing service for others once they have received a certain
amount of service. Examples include BitTorent's unchoking policy, BAR Gossip's
balanced exchanges, and threshold strategies in scrip systems. An attacker can
exploit this by providing service in a targeted way to prevent chosen nodes
from providing service. While such attacks cannot be prevented, we discuss
techniques that can be used to limit the damage they do. These techniques
presume that a certain number of processes will follow the recommended
protocol, even if they could do better by ``gaming'' the system.


title: HI Cosmology at z=0: a Brief Review

abstract:
  Extragalactic HI astronomy is half a century old. Its maturity dramatically
increased in the 1970s, with the commissioning of new powerful facilities. Its
contributions to Cosmology are important, from the observation of galaxy
rotation curves that showed the presence of dark matter in galaxies, to the
measurement of cosmological parameters and the mapping of the large scale
structure of the Universe. The Arecibo telecope has played a key role in these
developments. It is also currently engaged in a number of experiments that
utilize its L-band feed array to map thousands of square degrees of the sky and
obtain the most sensitive large-scale view of the low z HI Universe.


title: Vortex-enhanced alternating order around impurities in antiferromagnets

abstract:
  It has been recently pointed out that the presence of a nonmagnetic impurity
in a Heisenberg antiferromagnet generates an alternating order of the
surrounding spins which is independent of temperature in a wide range. Quantum
Monte Carlo simulations in the two-dimensional $S=1/2$ case confirmed this
picture, but showed a counterintuitive enhancement of the alternating order
around the Kosterlitz-Thouless transition. We propose here an explanation in
terms of the effect of vortex excitations.


title: Extragalactic HI Surveys at Arecibo: the Future

abstract:
  Starting in the 1970s, the Arecibo 305m telescope has made seminal
contributions in the field of extragalactic spectroscopy. With the Gregorian
upgrade completed in the late 1990s, the telescope acquired a field of view.
Population of that field of view with a seven-feed array at L-band (ALFA)
increased by nearly one order of magnitude its survey speed. As a result, much
of the extragalactic astronomy time of the telescope is now allocated to survey
projects, which are briefly discussed. The next technical development stage for
the 305m telescope is foreseen as that of a 40 beam system that would take
advantage of phased array technology: AO40. This would further speed up the
survey performance of the telescope. It is shown how the figure of merit for
survey speed of AO40 would be comparable with that of SKA-precursor facilities,
planned for operation in the next decade. A number of scientifically desirable
new surveys that would become possible with AO40 are briefly discussed.


title: Exclusive Baryon-Antibaryon Decays of the chi_cJ Mesons

abstract:
  Using a sample of 2.59 \times 10^7 psi(2S) decays collected by the CLEO--c
detector, we present results of a study of chi_{cJ} (J=0,1,2) decays into
baryon-antibaryon final states. We present the world's most precise
measurements of the chi_cJ -> p-pbar and chi_cJ -> Lambda-Lambdabar branching
fractions, and the first measurements of chi_c0 decays to other hyperons. These
results illuminate the decay mechanism of the chi_c states.


title: Multivariance as a crucial property of microcosm

abstract:
  The conventional method of a generalized geometry construction, based on
deduction of all propositions of the geometry from axioms, appears to be
imperfect in the sense, that multivariant geometries cannot be constructed by
means of this method. Multivariant geometry is such a geometry, where at the
point P there are many vectors PP', PP'',... which are equivalent to the vector
QQ' at the point Q, but they are not equivalent between themselves. In the
conventional (Euclidean) method the equivalence relation is transitive, whereas
in a multivariant geometry the equivalence relation is intransitive, in
general. It is a reason, why the multivariant geometries cannot be deduced from
a system of axioms. The space-time geometry in microcosm is multivariant.
Multivariant geometry is a grainy geometry, i.e. the geometry, which is partly
continuous and partly discrete. Multivariance is a mathematical method of the
graininess description. The graininess (and multivariance) of the space-time
geometry generates a multivariant (quantum) motion of particles in microcosm.
Besides, the grainy space-time generates some discrimination mechanism,
responsible for discrete parameters (mass, charge, spin) of elementary
particles. Dynamics of particles appears to be determined completely by
properties of the grainy space-time geometry. The quantum principles appear to
be needless.


title: Neutrino Physics with the IceCube Detector

abstract:
  IceCube is a cubic kilometer neutrino telescope under construction at the
South Pole. The primary goal is to discover astrophysical sources of high
energy neutrinos. We describe the detector and present results on atmospheric
muon neutrinos from 2006 data collected with nine detector strings.


title: Dependence of two-nucleon momentum densities on total pair momentum

abstract:
  Two-nucleon momentum distributions are calculated for the ground states of
3He and 4He as a function of the nucleons' relative and total momenta. We use
variational Monte Carlo wave functions derived from a realistic Hamiltonian
with two- and three-nucleon potentials. The momentum distribution of pp pairs
is found to be much smaller than that of pn pairs for values of the relative
momentum in the range (300--500) MeV/c and vanishing total momentum. However,
as the total momentum increases to 400 MeV/c, the ratio of pp to pn pairs in
this relative momentum range grows and approaches the limit 1/2 for 3He and 1/4
for 4He, corresponding to the ratio of pp to pn pairs in these nuclei. This
behavior should be easily observable in two-nucleon knock-out processes, such
as A(e,e'pN).


title:
On the origins of apparent fragile-to-strong transition of protein
  hydration waters

abstract:
  2H NMR is used to study the mechanisms for the reorientation of protein
hydration water. In the past, crossovers in temperature-dependent correlation
times were reported at T_x1=225K (X1) and T_x2=200K (X2). We show that neither
X1 nor X2 are related to a fragile-to-strong transition. Our results rule out
an existence of X1. Also, they indicate that water performs thermally activated
and distorted tetrahedral jumps at T<T_x2, implying that X2 originates in an
onset of this motion, which may be related to a universal defect diffusion in
materials with defined hydrogen-bond networks.


title:
Automorphisms of $P_8$ singularities and the complex crystallographic
  groups

abstract:
  The paper completes the study of symmetries of parabolic function
singularities with relation to complex crystallographic groups that was started
in \cite{GM,X9}. We classify smoothable automorphisms of $P_8$ singularities
which split the kernel of the intersection form on the second homology. For
such automorphisms, the monodromy groups acting on the duals to the eigenspaces
with degenerate intersection form are then identified as some of complex affine
reflection groups tabled in \cite{P}.


title: Linearizing a certain family of nonlinear differential equations

abstract:
  We show how to reduce the problem of solving members of a certain family of
nonlinear differential equations to that of solving some corresponding linear
differential equations.


title: Fast Arithmetics Using Chinese Remaindering

abstract:
  In this paper, some issues concerning the Chinese remaindering representation
are discussed. Some new converting methods, including an efficient
probabilistic algorithm based on a recent result of von zur Gathen and
Shparlinski \cite{Gathen-Shparlinski}, are described. An efficient refinement
of the NC$^1$ division algorithm of Chiu, Davida and Litow
\cite{Chiu-Davida-Litow} is given, where the number of moduli is reduced by a
factor of $\log n$.


title: Linear Augmented Slater-Type Orbital Method for Free Standing Clusters

abstract:
  We have developed a Scalable Linear Augmented Slater-Type Orbital (LASTO)
method for electronic-structure calculations on free-standing atomic clusters.
As with other linear methods we solve the Schr\"odinger equation using a mixed
basis set consisting of numerical functions inside atom-centered spheres and
matched onto tail functions outside. The tail functions are Slater-type
orbitals, which are localized, exponentially decaying functions. To solve the
Poisson equation between spheres, we use a finite difference method replacing
the rapidly varying charge density inside the spheres with a smoothed density
with the same multipole moments. We use multigrid techniques on the mesh, which
yield the Coulomb potential on the spheres and in turn defines the potential
inside via a Dirichlet problem. To solve the linear eigen-problem, we use
ScaLAPACK, a well-developed package to solve large eigensystems with dense
matrices. We have tested the method on small clusters of palladium.


title: Self-overlapping Curves Revisited

abstract:
  A surface embedded in space, in such a way that each point has a neighborhood
within which the surface is a terrain, projects to an immersed surface in the
plane, the boundary of which is a self-intersecting curve. Under what
circumstances can we reverse these mappings algorithmically? Shor and van Wyk
considered one such problem, determining whether a curve is the boundary of an
immersed disk; they showed that the self-overlapping curves defined in this way
can be recognized in polynomial time. We show that several related problems are
more difficult: it is NP-complete to determine whether an immersed disk is the
projection of a surface embedded in space, or whether a curve is the boundary
of an immersed surface in the plane that is not constrained to be a disk.
However, when a casing is supplied with a self-intersecting curve, describing
which component of the curve lies above and which below at each crossing, we
may determine in time linear in the number of crossings whether the cased curve
forms the projected boundary of a surface in space. As a related result, we
show that an immersed surface with a single boundary curve that crosses itself
n times has at most 2^{n/2} combinatorially distinct spatial embeddings, and we
discuss the existence of fixed-parameter tractable algorithms for related
problems.


title:
Linear Fractional Stable Sheets: wavelet expansion and sample path
  properties

abstract:
  In this paper we give a detailed description of the random wavelet series
representation of real-valued linear fractional stable sheet introduced in
Ayache, Roueff and Xiao (2007). By using this representation, in the case where
the sample paths are continuous, an anisotropic uniform and quasi-optimal
modulus of continuity of these paths is obtained as well as an upper bound for
their behavior at infinity and around the coordinate axes. The Hausdorff
dimensions of the range and graph of these stable random fields are then
derived.


title: On Cancellations of Ultraviolet Divergences in Supergravity Amplitudes

abstract:
  Concrete calculations have pointed out that amplitudes in perturbative
gravity exhibit unanticipated cancellations taming their ultraviolet behaviour
independently of supersymmetry. Similar ultraviolet behaviour of N=4
super-Yang-Mills and N=8 maximal supergravity has explicitly been observed
until three loops. These cancellations can be connected to two manifest
features of gravitational theories: firstly gauge invariance from
diffeomorphism symmetries and secondly that amplitudes are colourless and
exhibits crossing symmetry. We will give a simple physical explanation of the
cancellations exhibited in gravity amplitudes. We will discuss these two
properties in turn as well as the role of supersymmetry and string theory
dualities in the structure of multiloop amplitudes in supergravity.


title:
Bounded Budget Connection (BBC) Games or How to make friends and
  influence people, on a budget

abstract:
  Motivated by applications in social networks, peer-to-peer and overlay
networks, we define and study the Bounded Budget Connection (BBC) game - we
have a collection of n players or nodes each of whom has a budget for
purchasing links; each link has a cost as well as a length and each node has a
set of preference weights for each of the remaining nodes; the objective of
each node is to use its budget to buy a set of outgoing links so as to minimize
its sum of preference-weighted distances to the remaining nodes.
  We study the structural and complexity-theoretic properties of pure Nash
equilibria in BBC games. We show that determining the existence of a pure Nash
equilibrium in general BBC games is NP-hard. However, in a natural variant,
fractional BBC games - where it is permitted to buy fractions of links - a pure
Nash equilibrium always exists. A major focus is the study of (n,k)-uniform BBC
games - those in which all link costs, link lengths and preference weights are
equal (to 1) and all budgets are equal (to k). We show that a pure Nash
equilibrium or stable graph exists for all (n,k)-uniform BBC games and that all
stable graphs are essentially fair (i.e. all nodes have similar costs). We
provide an explicit construction of a family of stable graphs that spans the
spectrum from minimum total social cost to maximum total social cost. We also
study a special family of regular graphs in which all nodes imitate the "same"
buying pattern, and show that if n is sufficiently large no such regular graph
can be a pure Nash equilibrium. We analyze best-response walks on the
configuration defined by the uniform game. Lastly, we extend our results to the
case where each node seeks to minimize its maximum distance to the other nodes.


title: Noncommutative geometry as a functor

abstract:
  In this note the noncommutative geometry is interpreted as a functor, whose
range is a family of the operator algebras. Some examples are given and a
program is sketched.


title: On the transverse invariant for bindings of open books

abstract:
  Consider a transverse knot which is the binding of an open book for the
ambient contact manifold. In this paper, we show that the transverse invariants
defined by Lisca, Ozsvath, Stipsicz, and Szabo (LOSS) are nonvanishing for such
transverse knots. This is true regardless of whether or not the ambient contact
structure is tight. We also prove a vanishing theorem for LOSS's Legendrian and
transverse invariants. As a corollary, we show that if (T,\pi) is an open book
with connected binding, then the complement of T has no Giroux torsion.


title: The Removal of Artificially Generated Polarization in SHARP Maps

abstract:
  We characterize the problem of artificial polarization for the Submillimeter
High Angular Resolution Polarimeter (SHARP) through the use of simulated data
and observations made at the Caltech Submillimeter Observatory (CSO). These
erroneous, artificial polarization signals are introduced into the data through
misalignments in the bolometer sub-arrays plus pointing drifts present during
the data-taking procedure. An algorithm is outlined here to address this
problem and correct for it, provided that one can measure the degree of the
sub-array misalignments and telescope pointing drifts. Tests involving
simulated sources of Gaussian intensity profile indicate that the level of
introduced artificial polarization is highly dependent upon the angular size of
the source. Despite this, the correction algorithm is effective at removing up
to 60% of the artificial polarization during these tests. The analysis of
Jupiter data taken in January 2006 and February 2007 indicates a mean
polarization of 1.44%+/-0.04% and 0.95%+/-0.09%, respectively. The application
of the correction algorithm yields mean reductions in the polarization of
approximately 0.15% and 0.03% for the 2006 and 2007 data sets, respectively.


title: Experimental Tests of General Relativity

abstract:
  Einstein's general theory of relativity is the standard theory of gravity,
especially where the needs of astronomy, astrophysics, cosmology and
fundamental physics are concerned. As such, this theory is used for many
practical purposes involving spacecraft navigation, geodesy, and time transfer.
Here I review the foundations of general relativity, discuss recent progress in
the tests of relativistic gravity in the solar system, and present motivations
for the new generation of high-accuracy gravitational experiments. I discuss
the advances in our understanding of fundamental physics that are anticipated
in the near future and evaluate the discovery potential of the recently
proposed gravitational experiments.


title:
Signatures of Electronic Correlations in Optical Properties of
  LaFeAsO$_{1-x}$F$_x$

abstract:
  Spectroscopic ellipsometry is used to determine the dielectric function of
the superconducting LaFeAsO$_{0.9}$F$_{0.1}$ ($T_c$ = 27 K) and undoped LaFeAsO
polycrystalline samples in the wide range 0.01-6.5 eV at temperatures 10 $\leq
T \leq$ 350 K. The free charge carrier response in both samples is heavily
damped with the effective carrier density as low as 0.040$\pm$0.005 electrons
per unit cell. The spectral weight transfer in the undoped LaFeAsO associated
with opening of the pseudogap at about 0.65 eV is restricted at energies below
2 eV. The spectra of superconducting LaFeAsO$_{0.9}$F$_{0.1}$ reveal a
significant transfer of the spectral weight to a broad optical band above 4 eV
with increasing temperature. Our data may imply that the electronic states near
the Fermi surface are strongly renormalized due to electron-phonon and/or
electron-electron interactions.


title: A dynamic logic method for determining behaviors of biological networks

abstract:
  A dynamic logic method was developed to analyze molecular networks of cells
by combining Kauffman and Thomas's logic operations with molecular interaction
parameters. The logic operations characterize the discrete interactions between
biological components. The interaction parameters (e.g. response times)
describe the quantitative kinetics. The combination of the two quantitatively
characterizes the discrete biological interactions. A number of simple networks
were analyzed. The main results include: we proved the theorems to determine
bistable states and oscillation behaviors of networks, we showed that time
delays are essential for oscillation structures, we proved that single variable
networks do not have chaotic behaviors, and we explained why one signal can
have multiply responses. In addition, we applied the present method to the
analysis of the MAPK cascade, feed-forward loops, and mitosis cycle of budding
yeast cells.


title: Measurement of the Spin-Orbit Angle of Exoplanet HAT-P-1b

abstract:
  We present new spectroscopic and photometric observations of the HAT-P-1
planetary system. Spectra obtained during three transits exhibit the
Rossiter-McLaughlin effect, allowing us to measure the angle between the sky
projections of the stellar spin axis and orbit normal, \lambda = 3.7 +/- 2.1
degrees. The small value of \lambda for this and other systems suggests that
the dominant planet migration mechanism preserves spin-orbit alignment. Using
two new transit light curves, we refine the transit ephemeris and reduce the
uncertainty in the orbital period by an order of magnitude. We find a upper
limit on the orbital eccentricity of 0.067, with 99% confidence, by combining
our new radial-velocity measurements with those obtained previously.


title: Are cosmological neutrinos free-streaming?

abstract:
  Precision data from cosmology suggest neutrinos stream freely and hence
interact very weakly around the epoch of recombination. We study this issue in
a simple framework where neutrinos recouple instantaneously and stop streaming
freely at a redshift z_i. The latest cosmological data imply z_i < 1500, the
exact constraint depending somewhat on the assumed prior on z_i. This bound
translates into a limit on the coupling strength between neutrinos and
majoron-like particles phi, implying tau > 1 x 10^10 s (m_2/50 meV)^3 for the
decay nu_2 -> nu_1+phi.


title:
Phase Transitions, theta Behavior and Instantons in QCD and its
  Holographic Model

abstract:
  In the holographic model of QCD, theta dependence sharply changes at the
point of confinement deconfinement phase transition. In large N QCD such a
change in theta behavior can be related to the breakdown of the instanton
expansion at some critical temperature T_c. Associating this temperature with
confinement-deconfinement phase transition leads to the description of the
latter in terms of dissociation of instantons into the fractionally charged
instanton quarks. To elucidate this picture, we introduce the nonvanishing
chiral condensate in the deconfining phase and assume a specific lagrangian for
the eta' field in the confining phase. In the resulting picture the high
temperature phase of the theory consists of the dilute gas of instantons, while
the low temperature phase is described in terms of freely moving fractional
instanton quarks.


title: Electroweak Breaking on a Soft Wall

abstract:
  We extend the 5D gauge-higgs scenario to the soft-wall framework where the IR
brane is replaced by a smoothly decaying warp factor. The electroweak symmetry
of the Standard Model is embedded in a larger symmetry group whose gauge bosons
propagate in the bulk of a warped fifth dimension. This gauge symmetry is
partly broken by UV boundary conditions and by a condensate of a bulk scalar
field. The Higgs boson lives partly in the 5th component of the gauge field,
and partly in the the bulk scalar. The Higgs potential is not UV sensitive if
the condensate vanishes fast enough in the UV region. The soft-wall realization
opens new possibilities for the spectrum and the couplings of the Kaluza-Klein
resonances. We study two particular soft-wall backgrounds: one with resonances
whose masses follow the linear Regge trajectory, and another with a continuum
above a mass gap. We find that constraints on the Kaluza-Klein scale from
electroweak precision tests are less severe than in analogous models with the
IR brane. For the linear spectrum the typical constraint on the lightest
resonance mass is 2 TeV, while the continuum is allowed to start below 1 TeV.


title: The high-energy collision of two black holes

abstract:
  We study the head-on collision of two highly boosted equal mass, nonrotating
black holes. We determine the waveforms, radiated energies, and mode excitation
in the center of mass frame for a variety of boosts. For the first time we are
able to compare analytic calculations, black hole perturbation theory, and
strong field, nonlinear numerical calculations for this problem. Extrapolation
of our results, which include velocities of up to 0.94c, indicate that in the
ultra-relativistic regime about (14\pm 3)% of the energy is converted into
gravitational waves. This gives rise to a luminosity of order 10^-2 c^5/G, the
largest known so far in a black hole merger.


title: How Do Disks Survive Mergers?

abstract:
  We develop a physical model for how galactic disks survive and/or are
destroyed in interactions. Based on dynamical arguments, we show gas primarily
loses angular momentum to internal torques in a merger. Gas within some
characteristic radius (a function of the orbital parameters, mass ratio, and
gas fraction of the merging galaxies), will quickly lose angular momentum to
the stars sharing the perturbed disk, fall to the center and be consumed in a
starburst. A similar analysis predicts where violent relaxation of the stellar
disks is efficient. Our model allows us to predict the stellar and gas content
that will survive to re-form a disk in the remnant, versus being violently
relaxed or contributing to a starburst. We test this in hydrodynamic
simulations and find good agreement as a function of mass ratio, orbital
parameters, and gas fraction, in simulations spanning a wide range in these
properties and others, including different prescriptions for gas physics and
feedback. In an immediate sense, the amount of disk that re-forms can be
understood in terms of well-understood gravitational physics, independent of
details of ISM gas physics or feedback. This allows us to explicitly quantify
the requirements for such feedback to (indirectly) enable disk survival, by
changing the pre-merger gas content and distribution. The efficiency of disk
destruction is a strong function of gas content: we show how and why
sufficiently gas-rich major mergers can, under general conditions, yield
systems with small bulges (B/T<0.2). We provide prescriptions for inclusion of
our results in semi-analytic models.


title:
Gravitational Instabilities, Chondrule Formation, and the FU Orionis
  Phenomenon

abstract:
  Using analytic arguments and numerical simulations, we examine whether
chondrule formation and the FU Orionis phenomenon can be caused by the
burst-like onset of gravitational instabilities (GIs) in dead zones. At least
two scenarios for bursting dead zones can work, in principle. If the disk is on
the verge of fragmention, GI activation near $r\sim4$ to 5 AU can produce
chondrule-forming shocks, at least under extreme conditions. Mass fluxes are
also high enough during the onset of GIs to suggest that the outburst is
related to an FU Orionis phenomenon. This situation is demonstrated by
numerical simulations. In contrast, as supported by analytic arguments, if the
burst takes place close to $r\sim1$ AU, then even low pitch angle spiral waves
can create chondrule-producing shocks and outbursts. We also study the
stability of the massive disks in our simulations against fragmentation and
find that although disk evolution is sensitive to changes in opacity, the disks
we study do not fragment, even at high resolution and even for extreme
assumptions.


title: Heavy quark potential with dynamical flavors: a first order transition

abstract:
  We study the static potential between external quark-antiquark pairs in a
strongly coupled gauge theory with a large number of colors and massive
dynamical flavors, using a dual string description. When the constituent mass
of the dynamical quarks is set below a certain critical value, we find a first
order phase transition between a linear and a Coulomb-like regime. Above the
critical mass the two phases are smoothly connected. We also study the
dependence on the theory parameters of the quark-antiquark separation at which
the static configuration decays into specific static-dynamical mesons.


title:
Impact of Point Source Clustering on Cosmological Parameters with CMB
  Anisotropies

abstract:
  The faint radio point sources that are unresolved in cosmic microwave
background (CMB) anisotropy maps are likely to be a biased tracer of the
large-scale structure dark matter distribution. While the shot-noise
contribution to the angular power spectrum of unresolved radio point sources is
included either when optimally constructing the CMB angular power spectrum, as
with WMAP data, or when extracting cosmological parameters, we suggest that
clustering part of the point source power spectrum should also be included.
This is especially necessary at high frequencies above 150 GHz, where the
clustering of far-IR sources is expected to dominate the shot-noise level of
the angular power spectrum at tens of arcminute angular scales of both radio
and sub-mm sources. We make an estimate of source clustering of unresolved
radio sources in both WMAP and ACBAR, and marginalize over the amplitude of
source clustering in each CMB data set when model fitting for cosmological
parameters. For the combination of WMAP 5-year data and ACBAR, we find that the
spectral index changes from the value of $0.963 \pm 0.014$ to $0.959 \pm 0.014$
(at 68% c.l.) when the clustering power spectrum of point sources is included
in model fits. While we find that the differences are marginal with and without
source clustering in current data, it may be necessary to account for source
clustering with future datasets such as Planck, especially to properly model
fit anisotropies at arcminute angular scales. If clustering is not accounted
and point sources are modeled with a shot-noise only out to $l \sim 2000$, the
spectral index will be biased by about 1.5$\sigma$.


title:
A Z$_2$ spin-orbital liquid state in the square lattice Kugel-Khomskii
  model

abstract:
  We argue for the existence of a liquid ground state in a class of square
lattice models of orbitally degenerate insulators. Starting with the SU(4)
symmetric Kugel-Khomskii model, we utilize a Majorana Fermion representation of
spin-orbital operators to access novel phases. Variational wavefunctions of
candidate liquid phases are thus obtained, whose properties are evaluated using
Variational Monte Carlo. These states are disordered, and are found to have
excellent energetics and ground state overlap ($>40%$) when compared with exact
diagonalization on 16 site clusters. We conclude that these are spin-orbital
liquid ground states with emergent nodal fermions and Z$_2$ gauge fields.
Connections to spin 3/2 cold atom systems and properties in the absence of
SU(4) symmetry are briefly discussed.


title:
Geometrical control of the magnetization direction in high aspect-ratio
  PdNi ferromagnetic nano-electrodes

abstract:
  We present a study of electron-beam evaporated Pd0.4Ni0.6 alloy thin films by
means of ferromagnetic resonance measurements on extended films of varying
thickness and anisotropic magnetoresistance measurements of lithographically
patterned high aspect-ratio ferromagnetic electrodes, respectively. The results
reveal that the direction of the magnetization strongly depends on the
electrode lateral dimensions, transitioning from in-plane magnetization for
extended films to out-of-the-plane magnetization for electrode widths below 2-3
microns, reaching 58 degrees off-plane for 100 nm-wide nanoelectrodes.


title: Eigenvalue multiplicity and volume growth

abstract:
  Let $G$ be a finite group with symmetric generating set $S$, and let $c =
\max_{R > 0} |B(2R)|/|B(R)|$ be the doubling constant of the corresponding
Cayley graph, where $B(R)$ denotes an $R$-ball in the word-metric with respect
to $S$. We show that the multiplicity of the $k$th eigenvalue of the Laplacian
on the Cayley graph of $G$ is bounded by a function of only $c$ and $k$. More
specifically, the multiplicity is at most $\exp((\log c)(\log c + \log k))$.
  Similarly, if $X$ is a compact, $n$-dimensional Riemannian manifold with
non-negative Ricci curvature, then the multiplicity of the $k$th eigenvalue of
the Laplace-Beltrami operator on $X$ is at most $\exp(n^2 + n log k)$.
  The first result (for $k=2$) yields the following group-theoretic
application. There exists a normal subgroup $N$ of $G$, with $[G : N] \leq
\alpha(c)$, and such that $N$ admits a homomorphism onto the cyclic group
$Z_M$, where $M \geq |G|^{\delta(c)}$ and $\alpha(c), \delta(c) > 0$ are
explicit functions depending only on $c$. This is the finitary analog of a
theorem of Gromov which states that every infinite group of polynomial growth
has a subgroup of finite index which admits a homomorphism onto the integers.
  This addresses a question of Trevisan, and is proved by scaling down
Kleiner's proof of Gromov's theorem. In particular, we replace the space of
harmonic functions of fixed polynomial growth by the second eigenspace of the
Laplacian on the Cayley graph of $G$.


title: Complexity of stoquastic frustration-free Hamiltonians

abstract:
  We study several problems related to properties of non-negative matrices that
arise at the boundary between quantum and classical probabilistic computation.
Our results are twofold. First, we identify a large class of quantum
Hamiltonians describing systems of qubits for which the adiabatic evolution can
be efficiently simulated on a classical probabilistic computer. These are
stoquastic local Hamiltonians with a "frustration free" ground-state. A
Hamiltonian belongs to this class iff it can be represented as $H=\sum_a H_a$
where (1) every term $H_a$ acts non-trivially on a constant number of qubits,
(2) every term $H_a$ has real non-positive off-diagonal matrix elements in the
standard basis, and (3) the ground-state of $H$ is a ground-state of every term
$H_a$. Secondly, we generalize the Cook-Levin theorem proving NP-completeness
of the satisfiability problem to the complexity class MA -- a probabilistic
analogue of NP. Specifically, we construct a quantum version of the k-SAT
problem which we call "stoquastic k-SAT" such that stoquastic k-SAT is
contained in MA for any constant $k$, and any promise problem in MA is
Karp-reducible to stoquastic 6-SAT. This result provides the first non-trivial
example of a MA-complete promise problem.


title:
Exact quantum Monte Carlo study of one dimensional trapped fermions with
  attractive contact interactions

abstract:
  Using exact continuous quantum Monte Carlo techniques, we study the zero and
finite temperature properties of a system of harmonically trapped one
dimensional spin 1/2 fermions with short range interactions. Motivated by
experimental searches for modulated Fulde-Ferrel-Larkin-Ovchinikov states, we
systematically examine the impact of a spin imbalance on the density profiles.
We quantify the accuracy of the Thomas-Fermi approximation, finding that for
sufficiently large particle numbers (N > 100) it quantitatively reproduces most
features of the exact density profile. The Thomas-Fermi approximation fails to
capture small Friedel-like spin and density oscillations and overestimates the
size of the fully paired region in the outer shell of the trap. Based on our
results, we suggest a range of experimentally tunable parameters to maximize
the visibility of the double shell structure of the system and the
Fulde-Ferrel-Larkin-Ovchinikov state in the one dimensional harmonic trap.
Furthermore, we analyze the fingerprints of the attractive contact interactions
in the features of the momentum and pair momentum distributions.


title:
Black Hole or MECO? Decided by a Thin Luminous Ring Structure Deep
  Within Quasar Q0957

abstract:
  Optical, Infrared, X-ray, and radio wavelength studies of quasars are
beginning to define the luminous quasar structure from techniques of
reverberation and microlensing. An important result is that the inner quasar
structure of the first identified gravitational lens, Q0957+561 A,B seems not
to show the kind of structure expected for a supermassive black hole, but
instead show a clean-swept interior region as due to the action of a magnetic
propeller, just as expected for a MECO (Magnetic Eternally Collapsing Object)
structure. Given the present state of the observations, the strongest model
discriminant seems to be the existence of a thin luminous band around the inner
edge of the accretion disc, at a distant radius ~ 70 R_g from the ~ 4 x 10^9 Mo
central object. Since the existence of a clean magnetic propeller swept inner
region ~70 R_g surrounded by a sharp ~ 1 R_g disc edge are the low-hard state
spectral properties associated with a highly redshifted central MECO object, we
are led to the conclusion that these observations imply that the Q0957 quasar
contains a central supermassive MECO instead of a black hole. In this report we
review the details of the observations which have compelled us to reach this
conclusion.


title:
Consistency and Completeness of Rewriting in the Calculus of
  Constructions

abstract:
  Adding rewriting to a proof assistant based on the Curry-Howard isomorphism,
such as Coq, may greatly improve usability of the tool. Unfortunately adding an
arbitrary set of rewrite rules may render the underlying formal system
undecidable and inconsistent. While ways to ensure termination and confluence,
and hence decidability of type-checking, have already been studied to some
extent, logical consistency has got little attention so far. In this paper we
show that consistency is a consequence of canonicity, which in turn follows
from the assumption that all functions defined by rewrite rules are complete.
We provide a sound and terminating, but necessarily incomplete algorithm to
verify this property. The algorithm accepts all definitions that follow
dependent pattern matching schemes presented by Coquand and studied by McBride
in his PhD thesis. It also accepts many definitions by rewriting, containing
rules which depart from standard pattern matching.


title: On coproducts in varieties, quasivarieties and prevarieties

abstract:
  If the free algebra F on one generator in a variety V of algebras (in the
sense of universal algebra) has a subalgebra free on two generators, must it
also have a subalgebra free on three generators? In general, no; but yes if F
generates the variety V.
  Generalizing the argument, it is shown that if we are given an algebra and
subalgebras, A_0\supseteq ... \supseteq A_n, in a prevariety (SP-closed class
of algebras) P such that A_n generates P, and also subalgebras B_i\subseteq
A_{i-1} (0<i\leq n) such that for each i>0 the subalgebra of A_{i-1} generated
by A_i and B_i is their coproduct in P, then the subalgebra of A generated by
B_1, ..., B_n is the coproduct in P of these algebras.
  Some further results on coproducts are noted:
  If P satisfies the amalgamation property, one has the stronger "transitivity"
statement: if A has a finite family of subalgebras (B_i)_{i\in I} such that the
subalgebra of A generated by the B_i is their coproduct, and each B_i has a
finite family of subalgebras (C_{ij})_{j\in J_i} with the same property, then
the subalgebra of A generated by all the C_{ij} is their coproduct.
  For P a residually small prevariety or an arbitrary quasivariety,
relationships are proved between the least number of algebras needed to
generate P as a prevariety or quasivariety, and behavior of the coproduct
operation in P.
  It is shown by example that for B a subgroup of the group S = Sym(\Omega) of
all permutations of an infinite set \Omega, the group S need not have a
subgroup isomorphic over B to the coproduct with amalgamation S \cP_B S. But
under weak additional hypotheses on B, the question remains open.


title: Hadronic Light-by-Light Scattering in the Muonium Hyperfine Splitting

abstract:
  We consider an impact of hadronic light-by-light scattering on the muonium
hyperfine structure. A shift of the hyperfine interval $\Delta \nu({\rm Mu})
_{\rm\tiny HLBL}$ is calculated with the light-by-light scattering approximated
by exchange of pseudoscalar and pseudovector mesons. Constraints from the
operator product expansion in QCD are used to fix parameters of the model
similar to the one used earlier for the hadronic light-by-light scattering in
calculations of the muon anomalous magnetic moment. The pseudovector exchange
is dominant in the resulting shift, $\Delta \nu({\rm Mu})_{\rm\tiny HLBL}=
-0.0065(10) {Hz}$. Although the effect is tiny it is useful in understanding
the level of hadronic uncertainties.


title: Threshold solutions for the focusing 3d cubic Schroedinger equation

abstract:
  We study the focusing 3d cubic NLS equation with H^1 data at the mass-energy
threshold, namely, when M[u_0]E[u_0] = M[Q]E[Q]. In earlier works of
Holmer-Roudenko and Duyckaerts-Holmer-Roudenko, the behavior of solutions
(i.e., scattering and blow up in finite time) is classified when M[u_0]E[u_0] <
M[Q]E[Q]. In this paper, we first exhibit 3 special solutions: e^{it}Q and Q^+,
Q^-; here Q is the ground state, and Q^+, Q^- exponentially approach the ground
state solution in the positive time direction, meanwhile Q^+ having finite time
blow up and Q^- scattering in the negative time direction. Secondly, we
classify solutions at this threshold and obtain that up to \dot{H}^{1/2}
symmetries, they behave exactly as the above three special solutions, or
scatter and blow up in both time directions as the solutions below the
mass-energy threshold. These results are obtained by studying the spectral
properties of the linearized Schroedinger operator in this mass-supercritical
case, establishing relevant modulational stability and careful analysis of the
exponentially decaying solutions to the linearized equation.


title:
Magnetic circular dichroism from the impurity band in III-V diluted
  magnetic semiconductors

abstract:
  The magnetic circular dichroism of III-V diluted magnetic semiconductors,
calculated within a theoretical framework suitable for highly disordered
materials, is shown to be dominated by optical transitions between the bulk
bands and an impurity band formed from magnetic dopant states. The theoretical
framework incorporates real-space Green's functions to properly incorporate
spatial correlations in the disordered conduction band and valence band
electronic structure, and includes extended and localized electronic states on
an equal basis. Our findings reconcile unusual trends in the experimental
magnetic circular dichroism in III-V DMSs with the antiferromagnetic p-d
exchange interaction between a magnetic dopant spin and its host.


title:
Identifying the Low Luminosity Population of Embedded Protostars in the
  c2d Observations of Clouds and Cores

abstract:
  We present a search for all embedded protostars with internal luminosities <
1 solar luminosity in the sample of nearby, low-mass star-forming regions
surveyed by the Spitzer Space Telescope c2d Legacy Project. The internal
luminosity (Lint) of a source is the luminosity of the central source and
excludes luminosity arising from external heating. On average, the c2d data are
sensitive to embedded protostars with Lint > 4E-3 (d/140 pc)^2 solar
luminosities, a factor of 25 better than the sensitivity of IRAS to such
objects. We present selection criteria used to identify candidates from the
Spitzer data and examine complementary data to decide whether each candidate is
truly an embedded protostar. We find a tight correlation between the 70 micron
flux and internal luminosity of a protostar, an empirical result based on
observations and two-dimensional radiative transfer models of protostars. We
identify 50 embedded protostars with Lint < 1 solar luminosities; 15 have Lint
< 0.1 solar luminosities. The intrinsic distribution of source luminosities
increases to lower luminosities. While we find sources down to the above
sensitivity limit, indicating that the distribution may extend to luminosities
lower than probed by these observations, we are able to rule out a continued
rise in the distribution below 0.1 solar luminosities. Between 75-85% of cores
classified as starless prior to being observed by Spitzer remain starless to
our luminosity sensitivity; the remaining 15-25% harbor low-luminosity,
embedded protostars. We compile complete Spectral Energy Distributions for all
50 objects and calculate standard evolutionary signatures, and argue that these
objects are inconsistent with the simplest picture of star formation wherein
mass accretes from the core onto the protostar at a constant rate.


title:
Calibration and flight performance of the long-slit imaging dual order
  spectrograph

abstract:
  We present a preliminary calibration and flight performance of the Long-Slit
Imaging Dual Order Spectrograph (LIDOS), a rocket-borne instrument with a large
dynamic range in the 900 - 1700A bandpass. The instrument observes UV-bright
objects with a CCD channel and fainter nebulosity with an MCP detector. The
image quality and the detector quantum efficiencies were determined using the
calibration and test equipment at the Johns Hopkins University, and further
monitored using an on-board electron-impact calibration lamp. We review results
from each of the three flights of the instrument.


title:
An Experimental and Theoretical Study of the Variation of 4f
  Hybridization Across the La1-xCexIn3 Series

abstract:
  Crystal structures of a series of La1-xCexIn3 (x = 0.02, 0.2, 0.5, or 0.8)
intermetallic compounds have been investigated by both neutron and X-ray
diffraction, and their physical properties have been characterized by magnetic
susceptibility and specific heat measurements. Our results emphasize atypical
atomic displacement parameters (ADP) for the In and the rare-earth sites.
Depending on the x value, the In ADP presents either an "ellipsoidal"
elongation (La-rich compounds) or a "butterfly-like" distortion (Ce-rich
compounds). These deformations have been understood by theoretical techniques
based on the band theory and are the result of hybridization between conduction
electrons and 4f-electrons.


title: Classification of compact ancient solutions to the curve shortening flow

abstract:
  We consider an embedded convex ancient solution $\Gamma_t$ to the curve
shortening flow in $\mathbb{R}^2$. We prove that there are only two
possibilities: the family $\Gamma_t$ is either the family of contracting
circles, which is a type I ancient solution, or the family of evolving Angenent
ovals, which correspond to a type II ancient solution to the curve shortening
flow. We also give a necessary and sufficient curvature condition for an
embedded, closed ancient solution to the curve shortening flow to be convex.


title: The harmonic mean curvature flow of nonconvex surfaces in $\mathbb{R}^3$

abstract:
  We consider a compact, star-shaped, mean convex hypersurface $\Sigma^2\subset
\mathbb{R}^3$. We prove that in some cases the flow exists until it shrinks to
a point in a spherical manner, which is very typical for convex surfaces as
well (see \cite{An1}). We also prove that in the case we have a surface of
revolution which is star-shaped and mean convex, a smooth solution always
exists up to some finite time $T < \infty$ at which the flow shrinks to a point
asymptotically spherically.


title: Gregory Trees, The Continuum, And Martin's Axiom

abstract:
  We continue the investigation of Gregory trees and the Cantor Tree Property
carried out by Hart and Kunen. We produce models of MA with the Continuum
arbitrarily large in which there are Gregory trees, and in which there are no
Gregory trees.


title:
Charge asymmetries in \gamma\gamma \to \ell^+\ell^-+ \nu's (\ell=\mu, e)
  with polarized photons in the Standard Model

abstract:
  It is shown that in reaction \gamma\gamma\to\ell^+\ell^-+\nu's at
\sqrt{s}>200 GeV with polarized photons, large and well observable differences
arise in the distribution of positive and negative charged leptons
(\ell=\mu^\pm, e^\pm), (charge asymmetry). The modification due to the
contribution of the cascade processes with intermediate \tau-lepton in \gamma
\gamma \to W^\pm\ell^\mp + \nu's reaction is taken into account. This charge
asymmetry is potentially sensitive to effects of physics beyond the standard
model at the anticipated luminosity of the Photon Collider mode of the future
international linear collider.


title: Exact Ground State Energy of Hubbard Rings in the Atomic Limit

abstract:
  Using a straightforward extension of the analysis of Lieb and Wu, we derive a
simple analytic form for the ground state energy of a one-dimensional Hubbard
ring in the atomic limit. This result is valid for an \textit{arbitrary} number
of lattice sites $L$ and electrons $N \leq L$. Furthermore, our analysis,
including an application of the theory of stochastic matrices, provides insight
into the degeneracy and spin properties of the ground states in the atomic
limit. We give numerical results which illustrate how the atomic limit is
approached.


title:
Mass Media Influence Spreading in Social Networks with Community
  Structure

abstract:
  We study an extension of Axelrod's model for social influence, in which
cultural drift is represented as random perturbations, while mass media are
introduced by means of an external field. In this scenario, we investigate how
the modular structure of social networks affects the propagation of mass media
messages across the society. The community structure of social networks is
represented by coupled random networks, in which two random graphs are
connected by intercommunity links. Considering inhomogeneous mass media fields,
we study the conditions for successful message spreading and find a novel phase
diagram in the multidimensional parameter space. These findings show that
social modularity effects are of paramount importance in order to design
successful, cost-effective advertising campaigns.


title: Permutation equivalent maximal irreducible Goppa codes

abstract:
  We consider the problem of finding the number of permutation non-equivalent
classical irreducible maximal Goppa codes having fixed parameters q, n and r
from a group theory point of view.


title:
Averaged dynamics of time-periodic advection diffusion equations in the
  limit of small diffusivity

abstract:
  We study the effect of advection and small diffusion on passive tracers. The
advecting velocity field is assumed to have mean zero and to possess
time-periodic stream lines. Using a canonical transform to action-angle
variables followed by a Lie-transform, we derive an averaged equation
describing the effective motion of the tracers. An estimate for the time
validity of the first-order approximation is established. For particular cases
of a regularized vortical flow we present explicit formulas for the
coefficients of the averaged equation both at first and at second order.
Numerical simulations indicate that the validity of the above first-order
estimate extends to the second order.


title: Formes automorphes et theoremes de Riemann-Roch arithmetiques

abstract:
  Nous construisons trois familles de formes automorphes au moyen du theoreme
de Riemann-Roch arithmetique et de la formule de Lefschetz arithmetique. Deux
de ces familles ont deja ete construites par Yoshikawa et notre construction
met en lumiere leur origine arithmetique.
  -----
  We construct three families of automorphic forms following the arithmetic
Riemann-Roch theorem and the arithmetic Lefschetz formula. Two of these
families were already constructed by Yoshikawa and our construction illuminates
their arithmetic origin.


title: Gravitons, Dark Matter, and Classical Gravitation

abstract:
  We find that the quantum of gravity, the graviton, has time-varying mass (the
gomidium), and radius (the somium); both vary with the inverse of R; and its
frequency is given by Hubble's parameter. Dark matter can be made of such
gravitons. The number of gravitons varies with R-squared . The Machian radiated
power of the Universe leads us to a "correct" energy density for the gravitons
as dark matter.


title: Correction to "Simplicial monoids and Segal categories"

abstract:
  In this note we make a minor correction to the paper ``Simplicial monoids and
Segal categories."


title: Local Read-Write Operations in Sensor Networks

abstract:
  Designing protocols and formulating convenient programming units of
abstraction for sensor networks is challenging due to communication errors and
platform constraints. This paper investigates properties and implementation
reliability for a \emph{local read-write} abstraction. Local read-write is
inspired by the class of read-modify-write operations defined for shared-memory
multiprocessor architectures. The class of read-modify-write operations is
important in solving consensus and related synchronization problems for
concurrency control. Local read-write is shown to be an atomic abstraction for
synchronizing neighborhood states in sensor networks. The paper compares local
read-write to similar lightweight operations in wireless sensor networks, such
as read-all, write-all, and a transaction-based abstraction: for some
optimistic scenarios, local read-write is a more efficient neighborhood
operation. A partial implementation is described, which shows that three
outcomes characterize operation response: success, failure, and cancel. A
failure response indicates possible inconsistency for the operation result,
which is the result of a timeout event at the operation's initiator. The paper
presents experimental results on operation performance with different timeout
values and situations of no contention, with some tests also on various
neighborhood sizes.


title: Quantum cosmological Friedman models with an initial singularity

abstract:
  We consider the Wheeler-DeWitt equation $H\psi=0$ in a suitable Hilbert
space. It turns out that this equation has countably many solutions $\psi_i$
which can be considered as eigenfunctions of a Hamilton operator implicitly
defined by $H$. We consider two models, a bounded one, $0<r<r_0$, and an
unbounded, $0<r<\un$, which represent different eigenvalue problems. In the
bounded model we look for eigenvalues $\Lam_i$, where the $\Lam_i$ are the
values of the cosmological constant which we used in the Einstein-Hilbert
functional, and in the unbounded model the eigenvalues are given by
$(-\Lam_i)^{-\frac {n-1}{n}}$, where $\Lam_i<0$. The $\psi_i$ form a basis of
the underlying Hilbert space.
  All solutions have an initial singularity in $r=0$. Under certain
circumstances a smooth transition from big crunch to big bang is possible.


title:
SkyMapper and the Southern Sky Survey: a valuable resource for stellar
  astrophysics

abstract:
  The Australian National University's SkyMapper telescope is amongst the first
of a new generation of dedicated wide-field survey telescopes. Featuring a 5.7
square deg field-of-view Cassegrain imager and 268 Mega-pixel CCD array, its
primary goal will be to undertake the Southern Sky Survey: a six color
(uvgriz), six-epoch digital record of the entire southern sky. The survey will
provide photometry for objects between 8th and 23rd magnitude with a global
photometric accuracy of 0.03 magnitudes and astrometry to 50 mas. In this
contribution we introduce the SkyMapper facility, the survey data products and
outline a variety of case-studies in stellar astrophysics for which SkyMapper
will have high impact.


title: Evolution of Migrating Planets Undergoing Gas Accretion

abstract:
  We analyze the orbital and mass evolution of planets that undergo run-away
gas accretion by means of 2D and 3D hydrodynamic simulations. The disk torque
distribution per unit disk mass as a function of radius provides an important
diagnostic for the nature of the disk-planet interactions. We first consider
torque distributions for nonmigrating planets of fixed mass and show that there
is general agreement with the expectations of resonance theory. We then present
results of simulations for mass-gaining, migrating planets. For planets with an
initial mass of 5 Earth masses, which are embedded in disks with standard
parameters and which undergo run-away gas accretion to one Jupiter mass (Mjup),
the torque distributions per unit disk mass are largely unaffected by migration
and accretion for a given planet mass. The migration rates for these planets
are in agreement with the predictions of the standard theory for planet
migration (Type I and Type II migration). The planet mass growth occurs through
gas capture within the planet's Bondi radius at lower planet masses, the Hill
radius at intermediate planet masses, and through reduced accretion at higher
planet masses due to gap formation. During run-away mass growth, a planet
migrates inwards by only about 20% in radius before achieving a mass of ~1
Mjup. For the above models, we find no evidence of fast migration driven by
coorbital torques, known as Type III migration. We do find evidence of Type III
migration for a fixed mass planet of Saturn's mass that is immersed in a cold
and massive disk. In this case the planet migration is assumed to begin before
gap formation completes. The migration is understood through a model in which
the torque is due to an asymmetry in density between trapped gas on the leading
side of the planet and ambient gas on the trailing side of the planet.


title: On 2-partitionable clutters and the MFMC property

abstract:
  We introduce 2-partitionable clutters as the simplest case of the class of
$k$-partitionable clutters and study some of their combinatorial properties. In
particular, we study properties of the rank of the incidence matrix of these
clutters and properties of their minors.
  A well known conjecture of Conforti and Cornu\'ejols
  \cite{ConfortiCornuejols,cornu-book} states: That all the clutters with the
packing property have the max-flow min-cut property, i.e. are mengerian. Among
the general classes of clutters known to verify the conjecture are: balanced
clutters (Fulkerson, Hoffman and Oppenheim \cite{FulkersonHoffmanOppenheim}),
binary clutters (Seymour \cite{Seymour}) and dyadic clutters (Cornu\'ejols,
Guenin and Margot \cite{CornuejolsGueninMargot}). We find a new infinite family
of 2-partitionable clutters, that verifies the conjecture.
  On the other hand we are interested in studying the normality of the Rees
algebra associated to a clutter and possible relations with the Conforti and
Cornu\'ejols conjecture. In fact this conjecture is equivalent to an algebraic
statement about the normality of the Rees algebra \cite{rocky}.


title:
Exact solution for infinitely strongly interacting Fermi gases in tight
  waveguides

abstract:
  We present an exact analytical solution of the fundamental systems of
quasi-one-dimensional spin-1/2 fermions with infinite repulsion for arbitrary
confining potential. The eigenfunctions are constructed by the combination of
Gireardeau's hard-core contacting boundary condition and group theoretical
method which guarantees the obtained states to be simultaneously the
eigenstates of $S$ and $S_z$ and fulfill the antisymmetry under odd
permutation. We show that the total ground-state density profile behaves like
the polarized noninteracting fermions, whereas the spin-dependent densities
display different properties for different spin configurations. We also discuss
the splitting of the ground states for large but finite repulsion.


title:
Some reducible Specht modules for Iwahori--Hecke algebras of type $A$
  with $q=-1$

abstract:
  The reducibility of the Specht modules for the Iwahori--Hecke algebras in
type $A$ is still open in the case where the defining parameter $q$ equals -1.
We prove the reducibility of a large class of Specht modules for these
algebras.


title:
Particle size effect on strength, failure and shock behavior in
  Polytetrafluoroethylene-Al-W granular composites

abstract:
  The variation of metallic particle size and sample porosity significantly
alters the dynamic mechanical properties of high density granular composites
processed using a cold isostatically pressed mixture of polytetrafluoroethylene
(PTFE), aluminum (Al) and tungsten (W) powders. Quasi-static and dynamic
experiments are performed with identical constituent mass fractions with
variations in the size of the W particles and pressing conditions. The
relatively weak polymer matrix allows the strength and fracture modes of this
material to be governed by the granular type behavior of agglomerated metal
particles. A higher ultimate compressive strength was observed in relatively
high porosity samples with small W particles compared to those with coarse W
particles in all experiments. Mesoscale granular force chains comprised of the
metallic particles explain this unusual phenomenon as observed in a hydrocode
simulation of a drop-weight test. Macrocracks forming below the critical
failure strain for the matrix and unusual behavior due to a competition between
densification and fracture in dynamic tests of porous samples were also
observed. Shock loading of this granular composite resulted in higher fraction
of total internal energy deposition in the soft PTFE matrix, specifically
thermal energy, which can be tailored by the W particle size distribution.


title: A non-crossing standard monomial theory

abstract:
  The second author has introduced non-crossing tableaux, objects whose
non-nesting analogues are semi-standard Young tableaux. We relate non-crossing
tableaux to Gelfand-Tsetlin patterns and develop the non-crossing analogue of
standard monomial theory. Leclerc and Zelevinsky's weakly separated sets are
special cases of non-crossing tableaux, and we suggest that non-crossing
tableaux may help illuminate the theory of weakly separated sets.


title: Spin echo in spinor dipolar Bose-Einstein condensates

abstract:
  We theoretically propose and numerically realize spin echo in a spinor
Bose--Einstein condensate (BEC). We investigate the influence on the spin echo
of phase separation of the condensate. The equation of motion of the spin
density exhibits two relaxation times. We use two methods to separate the
relaxation times and hence demonstrate a technique to reveal magnetic
dipole--dipole interactions in spinor BECs.


title:
Proposal of an eavesdropping experiment for BB84 QKD protocol with 1-3
  phase-covariant quantum cloner

abstract:
  We propose an eavesdropping experiment with linear optical 1-3
phase-covariant quantum cloner. In this paper, we have designed an optical
circuit of the cloner and shown how the eavesdropper (Eve) utilizes her clones.
We have also optimized the measurement scheme for Eve by numerical calculation.
The optimized measurement is easy to implement with liner optics.


title: Analytic families of holomorphic iterated function systems

abstract:
  This paper deals with analytic families of holomorphic iterated function
systems. Using real analyticity of the pressure function (which we prove), we
establish a classification theorem for analytic families of holomorphic
iterated function systems which depend continuously on a parameter when the
space of holomorphic iterated function systems is endowed with the
"$\lambda$-topology". This classification theorem allows us to generalize some
geometric results from the paper ("Lambda-Topology vs. Pointwise Topology", to
appear in Ergod. Th. & Dynam. Sys.) of the authors, and gives us a better and
clearer understanding of the global structure of the space of conformal IFSs.


title:
Finite-frequency current (shot) noise in coherent resonant tunneling
  through a coupled-quantum-dot interferometer

abstract:
  We examine the shot noise spectrum properties of coherent resonant tunneling
in coupled quantum dots in both series and parallel arrangements by means of
quantum rate equations and MacDonald's formula. Our results show that, for a
series-CQD with a relatively high dot-dot hopping $\Omega$,
$\Omega/\Gamma\gtrsim 1$ ($\Gamma$ denotes the dot-lead tunnel-coupling
strength), the noise spectrum exhibits a dip at the Rabi frequency, $2\Omega$,
in the case of noninteracting electrons, but the dip is supplanted by a peak in
the case of strong Coulomb repulsion; furthermore, it becomes a dip again for a
completely symmetric parallel-CQD by tuning enclosed magnetic-flux.


title:
An "Ultrasonic Image" of the Embryonic Universe: CMB Polarization Tests
  of the Inflationary Paradigm

abstract:
  This chapter describes how the Cosmic Gravitational Wave Background induces a
specific type of CMB polarization and describes the first experiment dedicated
to testing this most-promising signature of inflation. This experiment, the
Background Imaging of Cosmic Extragalactic Polarization (BICEP) project, has
recently embarked on its third observing season. We show preliminary data from
the BICEP's first season obtained with a novel polarization modulation
mechanism called the "Faraday Rotation Modulator". Our discussion ends with a
description of exciting new technology with the potential to probe inflation
down to the GUT-scale.


title:
Well-posedness for compressible Euler equations with physical vacuum
  singularity

abstract:
  An important problem in the theory of compressible gas flows is to understand
the singular behavior of vacuum states. The main difficulty lies in the fact
that the system becomes degenerate at the vacuum boundary, where the
characteristics coincide and have unbounded derivative. In this paper, we
overcome this difficulty by presenting a new formulation and new energy spaces.
We establish the local in time well-posedness of one-dimensional compressible
Euler equations for isentropic flows with the physical vacuum singularity in
some spaces adapted to the singularity.


title: D-branes and doubled geometry

abstract:
  We define the open string version of the nonlinear sigma model on doubled
geometry introduced by Hull and Reid-Edwards, and derive its boundary
conditions. These conditions include the restriction of D-branes to maximally
isotropic submanifolds as well as a compatibility condition with the Lie
algebra structure on the doubled space. We demonstrate a systematic method to
derive and classify D-branes from the boundary conditions, in terms of
embeddings both in the doubled geometry and in the physical target space. We
apply it to the doubled three-torus with constant H-flux and find D0-, D1-, and
D2-branes, which we verify transform consistently under T-dualities mapping the
system to f-, Q- and R-flux backgrounds.


title:
Fidelity, purity and entanglement of two-mode spatially
  Gaussian-entangled light fields in Turbulence Atmosphere

abstract:
  In this paper, we investigate the propagation of two-mode spatially
Gaussian-entangled quantum light fields passing through the turbulence
atmosphere. From the propagation formula of the two-mode wave function in the
position representation, we have derived the analytical expressions for the
fidelity, purity and logarithmic negativity (entanglement) of the resulting
quantum state after the long-distance atmospheric transportation. Based on the
derived formulae, the effects of the atmospheric turbulences on the evolutions
of quantum properties of the resulting two-mode quantum state are discussed in
detail under different input parameters of the initial two-mode quantum state.
The results show that the maximal distributing distance of quantum entanglement
is strongly dependent on the atmospheric conditions: when the atmospheric
turbulence becomes stronger and stronger, the maximal distance becomes shorter
and shorter, and both the fidelity and purity decrease quicker and quicker as
functions of propagating distances. Under a certain atmospheric condition, with
the increasing of the input entanglement of the initial two-mode spatially
Gaussian-entangled quantum state, the maximal distributing distance for
preserving the entanglement gradually increases and always has a saturated
(upper) limitation, and both the evolutions of the fidelity and purity are
affected by the input parameters of the initial two-mode quantum state, Finally
the optimal parameters of the input two-mode quantum state with the fixed input
entanglement are discussed in order to obtain the optimal transfer distribution
of the quantum entanglement over a long distance under a certain atmosphere.
Our theoretical results are very helpful for building the distribution of the
quantum entanglement via free-space atmosphere link.


title: Energy-efficient motion camouflage in three dimensions

abstract:
  Recent observations suggest that one insect may camouflage its own motion
whilst tracking another. Here we present a strategy by which one agent can
efficiently track and intercept another agent, whilst camouflaging its own
motion and minimizing its energy consumption


title: Iterative Structure of the N=4 SYM Spin Chain

abstract:
  We develop algebraic methods for finding loop corrections to the N=4 SYM
dilatation generator, within the noncompact psu(1,1|2) sector. This sector
gives a 't Hooft coupling lambda-dependent representation of psu(1,1|2) times
psu(1|1)^2. At first working independently of the representation, we present an
all-order algebraic ansatz for the lambda-dependence of this Lie algebra's
generators. The ansatz solves the symmetry constraints if an auxiliary
generator, h, satisfies certain simple commutation relations with the Lie
algebra generators. Applying this to the psu(1,1|2) sector leads to an
iterative solution for the planar three-loop dilatation generator in terms of
leading order symmetry generators and h, which passes a thorough set of
spectral tests. We argue also that this algebraic ansatz may be applicable to
the nonplanar theory as well.


title:
The Origin and Evolution of \civ Baldwin Effect in QSOs from the Sloan
  Digital Sky Survey

abstract:
  Using a large sample of 26623 quasars with redshifts in the range $1.5 \le
z\le 5.1$ with \civ $\lambda$1549 \AA emission line in Fifth Data Release of
the Sloan Digital Sky Survey (SDSS), we investigate the cosmological evolution
of the Baldwin Effect, i.e. the relation between the equivalent width (EW) of
the \civ emission line and continuum luminosity. We confirm the earlier result
that there exists a strong correlation between the \civ EW and the continuum
luminosity, and we find that, up to $z\approx 5$, the slope of the Baldwin
Effect seems to have no effect of cosmological evolution. A sub-sample of 13960
quasars with broad \civ $\lambda$1549 \AA emission line from SDSS is used to
explore the origin of the Baldwin Effect. We find that \civ EW have a strong
correlation with the mass of supermassive black hole (SMBH), and a weak
correlation with the Eddington ratio, $\lb/\ledd$. This suggests that the SMBH
mass is probably the primary drive for the Baldwin Effect.


title: Quasi-Normal Modes in Topologically Massive Gravity

abstract:
  We determine the black hole quasi-normal mode spectrum for tensor
perturbations in topologically massive AdS-gravity. In the special case of
chiral gravity quasi-normal modes are absent despite of the presence of a
horizon. In the process we uncover a simple algebraic structure in the quasi
normal modes spectrum: the tower of QNM's consists of descendents of a "chiral
highest weight'' QNM which in turn satisfies a first order equation.


title:
Towards a guided atom interferometer based on a superconducting atom
  chip

abstract:
  We evaluate the realization of a novel geometry of a guided atom
interferometer based on a high temperature superconducting microstructure. The
interferometer type structure is obtained with a guiding potential realized by
two current carrying superconducting wires in combination with a closed
superconducting loop sustaining a persistent current. We present the layout and
realization of our superconducting atom chip. By employing simulations we
discuss the critical parameters of the interferometer guide in particular near
the splitting regions of the matter waves. Based on measurements of the
relevant chip properties we discuss the application of a compact and reliable
on-chip atom interferometer.


title: Point defects and clustering in uranium dioxide by LSDA+U calculations

abstract:
  A comprehensive investigation on point defects and their clustering behavior
in nonstoichiometric uranium dioxide UO2+x is carried out using LSDA+U method
based on density functional theory. Accurate energetic information and charge
transfers available so far are obtained. With these energies that have improved
more than 50% over that of pure GGA and LDA, we show the density functional
theory predicts the predominance of oxygen defects over uranium ones at any
compositions, which is possible only after treated the localized 5f electrons
properly. Calculations also suggest an upper bound of x~0.03 for oxygen
clusters to start off. The volume change induced by point uranium defects is
monotonic but nonlinear, whereas for oxygen defects, increase x always reduces
the system volume linearly, except dimers that require extra space for
accommodation, which has been identified as meta-stable ionic molecule. Though
oxygen dimers usually occupy Willis O'' sites and mimic a single oxygen in
energetics and charge state, they are rare at ambient conditions. Its
decomposition process and vibrational properties have been studied carefully.
To obtain a general clustering mechanism in anion-excess fluorites
systematically, we also analyze the local stabilities of possible basic
clustering modes of oxygen defects. The result shows an unified way to
understand the structure of Willis type and cuboctahedral clusters in UO2+x and
beta-U4O9. Finally we generalize the point defect model to the independent
clusters approximation to include clustering effects, the impact on defect
populations is discussed.


title: Planar Algebra of the Subgroup-Subfactor

abstract:
  We give an identification between the planar algebra of the
subgroup-subfactor $R \rtimes H \subset R \rtimes G$ and the $G$-invariant
planar subalgebra of the planar algebra of the bipartite graph $\star_n$, where
$n = [G : H]$. The crucial step in this identification is an exhibition of a
model for the basic construction tower, and thereafter of the standard
invariant, of $R \rtimes H \subset R \rtimes G$ in terms of operator matrices.
We also obtain an identification between the planar algebra of the fixed
algebra subfactor $R^G \subset R^H$ and the $G$-invariant planar subalgebra of
the planar algebra of the `flip' of $\star_n $.


title:
Stability mechanism of cuboctahedral clusters in UO2: First-principles
  calculations

abstract:
  The stability mechanism of cuboctahedral clusters in nonstoichiometric
uranium dioxide is investigated by first-principles LSDA+U method. Calculations
reveal that the structural stability is inherited from U6O12 molecular cluster
whereas the energy gain through occupying its center with an additional oxygen
makes the cluster win out by competition with point oxygen interstitials. Local
displacement of the center oxygen along <111> direction also leads the cluster
8-folded degeneracy and increases relatively the concentration at finite
temperatures. But totally, elevation of temperature, i.e., the effect of
entropy, favors point interstitial over cuboctahedral clusters.


title: Ab initio investigation on oxygen defect clusters in UO2+x

abstract:
  By first-principles LSDA+U calculations, we revealed that the current
physical picture of defective uranium dioxide suggested solely by neutron
diffraction analysis is unsatisfactory. An understanding based on quantum
theory has been established as a thermodynamical competition among point
defects and cuboctahedral cluster, which naturally interprets the puzzled
origin of the asymmetric O' and O'' interstitials. It also gives a clear and
consistent agreement with most available experimental data. Unfortunately, the
observed high occupation of O'' site cannot be accounted for in this picture
and is still a challenge for theoretical simulations.


title: Frequency stabilization of an ultraviolet laser to ions in a discharge

abstract:
  We stabilize an ultraviolet diode laser system at 369.5 nm to the optical
absorption signal from Yb+ ions in a hollow-cathode discharge lamp. The error
signal for stabilization is obtained by Zeeman spectroscopy of the 3 GHz-wide
absorption feature. The frequency stability is independently measured by
comparison against the fluorescence signal from a laser-cooled crystal of
174Yb+ ions in a linear Paul trap. We measure a frequency fluctuation of 1.7
MHz RMS over 1000 s, and a frequency drift of 20 MHz over 7 days. Our method is
suitable for use in quantum information processing experiments with trapped ion
crystals.


title: Nuclear pairing at finite temperature and angular momentum

abstract:
  An approach is proposed to nuclear pairing at finite temperature and angular
momentum, which includes the effects of the quasiparticle-number fluctuation
and dynamic coupling to pair vibrations within the self-consistent
quasiparticle random-phase approximation. The numerical calculations of pairing
gaps, total energies, and heat capacities are carried out within a doubly
folded multilevel model as well as several realistic nuclei. The results
obtained show that, in the region of moderate and strong couplings, the sharp
transition between the superconducting and normal phases is smoothed out,
causing a thermal pairing gap, which does not collapse at a critical
temperature predicted by the conventional Bardeen-Cooper-Schrieffer's (BCS)
theory, but has a tail extended to high temperatures. The theory also predicts
the appearance of a thermally assisted pairing in hot rotating nuclei.


title: Evaluation for Uncertain Image Classification and Segmentation

abstract:
  Each year, numerous segmentation and classification algorithms are invented
or reused to solve problems where machine vision is needed. Generally, the
efficiency of these algorithms is compared against the results given by one or
many human experts. However, in many situations, the location of the real
boundaries of the objects as well as their classes are not known with certainty
by the human experts. Furthermore, only one aspect of the segmentation and
classification problem is generally evaluated. In this paper we present a new
evaluation method for classification and segmentation of image, where we take
into account both the classification and segmentation results as well as the
level of certainty given by the experts. As a concrete example of our method,
we evaluate an automatic seabed characterization algorithm based on sonar
images.


title:
A new generalization of the proportional conflict redistribution rule
  stable in terms of decision

abstract:
  In this chapter, we present and discuss a new generalized proportional
conflict redistribution rule. The Dezert-Smarandache extension of the
Demster-Shafer theory has relaunched the studies on the combination rules
especially for the management of the conflict. Many combination rules have been
proposed in the last few years. We study here different combination rules and
compare them in terms of decision on didactic example and on generated data.
Indeed, in real applications, we need a reliable decision and it is the final
results that matter. This chapter shows that a fine proportional conflict
redistribution rule must be preferred for the combination in the belief
function theory.


title: Human expert fusion for image classification

abstract:
  In image classification, merging the opinion of several human experts is very
important for different tasks such as the evaluation or the training. Indeed,
the ground truth is rarely known before the scene imaging. We propose here
different models in order to fuse the informations given by two or more
experts. The considered unit for the classification, a small tile of the image,
can contain one or more kind of the considered classes given by the experts. A
second problem that we have to take into account, is the amount of certainty of
the expert has for each pixel of the tile. In order to solve these problems we
define five models in the context of the Dempster-Shafer Theory and in the
context of the Dezert-Smarandache Theory and we study the possible decisions
with these models.


title: Construction of localized atomic wave packets

abstract:
  It is shown that highly localized solitons can be created in lower
dimensional Bose-Einstein condensates (BEC), trapped in a regular harmonic
trap, by temporally varying the trap frequency. A BEC trapped in such a trap
can be effectively used to construct a pulsed atomic laser emitting coherent
atomic wave packets. It is also shown that one has complete control over the
spatio-temporal dynamics of the solitons. The dynamics of these solitons are
compared with those constructed in a BEC where the trap frequency is constant.


title:
Conversion of nuclear to 2-flavour quark matter in rotating compact
  stars: A general relativistic perspective

abstract:
  The conversion of neutron star to strange star is argued to be a two step
process. The first process involves the deconfinement of nuclear to two-flavour
quark matter. The GR results shows that the propagating front breaks up into
fragments which propagate with different velocities along different directions.
The time taken for this conversion to happen is of the order of few $ms$. This
calculation indicates the inadequacy of non-relativistic (NR) or even Special
Relativistic (SR) treatments for these cases.


title: Fine-structure infrared lines from the Cassiopeia A knots

abstract:
  Aims: Archival observations of infrared fine-structure lines of the young
Galactic supernova remnant Cassiopeia A allow us to test existing models and
determine the physical parameters of various regions of the fast-moving knots
(FMKs), which are metal-dominated clouds of material ejected by the supernova
explosion. Methods: The fluxes of the far-infrared [O i] and [O iii] lines are
extracted from the previously unpublished archival ISO data. The archival
Spitzer data are used to determine the fluxes of the O, Ne, Si, S, Ar and Fe
ion fine-structure lines originating in the FMKs. The ratios of these line
fluxes are used for the plasma diagnostics. We also determine the infrared line
flux ratios to the optical [O iii] 5007 A line in the knots having previously
measured reddening. Additionally, we analyze several optical and near-infrared
observations of the FMKs to obtain clearer insight into the post-shock
photoionized region (PIR) structure. Results: We show that the infrared oxygen
line flux predictions of all existing theoretical models are correct only to
within a factor of several. For the models to reproduce the observations it is
essential to include the electron conductivity and effects of the dust.
Detailed analysis of the diagnostic line flux ratios allows us to qualitatively
confirm the general model of the FMK emission and to determine observationally
the physical conditions in the PIR after the shock front. We infer that the
pre-shock cloud densities most probably constitute several hundred particles
per cm^3. We also determine the Cas A luminosities in the infrared continuum
and lines. We show that accounting for the charge exchange processes in the
post-shock PIR allows us to reproduce most of the relevant spectral line ratios
even in the frame of a single-temperature model of this region. We also
estimate its plasma parameters, thickness, and carbon abundance.


title:
Une nouvelle r\`egle de combinaison r\'epartissant le conflit -
  Applications en imagerie Sonar et classification de cibles Radar

abstract:
  These last years, there were many studies on the problem of the conflict
coming from information combination, especially in evidence theory. We can
summarise the solutions for manage the conflict into three different
approaches: first, we can try to suppress or reduce the conflict before the
combination step, secondly, we can manage the conflict in order to give no
influence of the conflict in the combination step, and then take into account
the conflict in the decision step, thirdly, we can take into account the
conflict in the combination step. The first approach is certainly the better,
but not always feasible. It is difficult to say which approach is the best
between the second and the third. However, the most important is the produced
results in applications. We propose here a new combination rule that
distributes the conflict proportionally on the element given this conflict. We
compare these different combination rules on real data in Sonar imagery and
Radar target classification.


title:
On isomorphism classes and invariants of low dimensional complex
  filiform Leibniz algebras (part 2)

abstract:
  The paper is an implementation in low dimensional cases of the classification
method presented before by Rakhimov and Bekbaev. We give a complete
classification of a subclass of complex filiform Leibniz algebras obtained from
the naturally graded non-Lie filiform Leibniz algebras. A hypothetic formula
for the adapted number of isomorphism classes is given.


title: Study of the $\eta-^7Be$ Interaction Near Threshold in $p-^6Li$ Fusion

abstract:
  We present a calculation for $\eta$ production in the $p-^6Li$ fusion near
threshold including the $\eta-^7Be$ final state interaction (FSI). We consider
the $^6Li$ and $^7Be$ nuclei as $\alpha-d$ and $\alpha-^3He$ clusters
respectively. The calculations are done for the lowest states of $^7Be$ with $J
= ({3\over2}^-, {1\over2}^-)$ resulting from the $L = $1 radial wave function.
The $\eta-^7Be$ interaction is incorporated through the $\eta-^7Be$ $T-$matrix,
constructed from the medium modified matrices for the $\eta-^3He$ and
$\eta-\alpha$ systems. These medium modified matrices are obtained by solving
few body equations, where the scattering in nuclear medium is taken into
account.


title:
A fully integrated Boltzmann+hydrodynamics approach: Multiplicities,
  transverse dynamics and HBT

abstract:
  We present a coupled Boltzmann and hydrodynamics approach to relativistic
heavy ion reactions. This hybrid approach is based on the Ultra-relativistic
Quantum Molecular Dynamics (UrQMD) transport approach with an intermediate
hydrodynamical evolution for the hot and dense stage of the collision. This
implementation allows to compare microscopic transport calculations with
hydrodynamic calculations using exactly the same initial conditions and
freeze-out procedure. Here, the results of the different calculations for
particle multiplicities, the mean transverse mass excitation function and the
HBT radii at all SPS energies are discussed in the context of the available
data.


title: Perfect Derived Propagators

abstract:
  When implementing a propagator for a constraint, one must decide about
variants: When implementing min, should one also implement max? Should one
implement linear equations both with and without coefficients? Constraint
variants are ubiquitous: implementing them requires considerable (if not
prohibitive) effort and decreases maintainability, but will deliver better
performance.
  This paper shows how to use variable views, previously introduced for an
implementation architecture, to derive perfect propagator variants. A model for
views and derived propagators is introduced. Derived propagators are proved to
be indeed perfect in that they inherit essential properties such as correctness
and domain and bounds consistency. Techniques for systematically deriving
propagators such as transformation, generalization, specialization, and
channeling are developed for several variable domains. We evaluate the massive
impact of derived propagators. Without derived propagators, Gecode would
require 140000 rather than 40000 lines of code for propagators.


title: Finite-gap integration of the SU(2) Bogomolny equations

abstract:
  The ADHMN construction of magnetic monopoles is given in terms of the
(normalizable) solutions of an associated Weyl equation. We focus here on
solving this equation directly by algebro-geometric means. The (adjoint) Weyl
equation is solved using an ans\"atz of Nahm in terms of Baker-Akhiezer
functions. The solution of Nahm's equation is not directly used in our
development.


title: Poisson structure on a space with linear SU(2) fuzziness

abstract:
  The Poisson structure is constructed for a model in which spatial coordinates
of configuration space are noncommutative and satisfy the commutation relations
of a Lie algebra. The case is specialized to that of the group SU(2), for which
the counterpart of the angular momentum, as well as the Euler parameterization
of the phase space are introduced. SU(2)-invariant classical systems are
discussed, and it is observed that the path of particle can be obtained by the
solution of a first-order equation, as the case with such models on commutative
spaces. The examples of free particle, rotationally-invariant potentials, and
specially the isotropic harmonic oscillator are investigated in more detail.


title: Coefficients of squares of Newman polynomials

abstract:
  We show that there are polynomials $p_N$ of arbitrarily large degree $N$,
with coefficients equal to 0 or 1 (Newman polynomials), such that $$ \liminf_{N
\to \infty} N \Linf{p_N^2} \bigl / p_N^2(1) < 1, $$ where $\Linf{q}$ denotes
the maximum coefficient of the polynomial $q$ and which, at the same time, are
sparse: $p_N(1)/N \to 0$. This disproves a conjecture of Yu \cite{yu}. We build
on some previous results of Berenhaut and Saidak \cite{berenhaut-saidak} and
Dubickas \cite{dubickas} whose examples lacked the sparsity. This sparsity we
create from these examples by randomization.


title: Quantum Invariants of the Pairing Hamiltonian

abstract:
  Quantum invariants of the orbit dependent pairing problem are identified in
the limit where the orbits become degenerate. These quantum invariants are
simultaneously diagonalized with the help of the Bethe ansatz method and a
symmetry in their spectra relating the eigenvalues corresponding to different
number of pairs is discussed. These quantum invariants are analogous to the
well known rational Gaudin magnet Hamiltonians which play the same role in the
reduced pairing case (i.e., orbit independent pairing with non degenerate
energy levels). It is pointed out that although the reduced pairing and the
degenerate cases are opposite of each other, the Bethe ansatz diagonalization
of the invariant operators in both cases are based on the same algebraic
structure described by the rational Gaudin algebra.


title: Modeling $\epsilon$ Eridani and asteroseismic tests of element diffusion

abstract:
  Taking into account the helium and metal diffusion, we explore the possible
evolutionary status and perform seismic analysis of MOST target: the star
$\epsilon$ Eridani. We adopt the different input parameters to construct the
models by fitting the available observational constraints: e.g., $T_{eff}$,
$L$, $R$, $[Fe/H]$. From computation, we obtain the average large spacings of
$\epsilon$ Eridani about $194\pm 1 \mu$Hz. The age of the diffused models has
been found to be about 1 Gyr, which is younger than one determined previously
by models without diffusion. We found that the effect of pure helium diffusion
on the internal structure of the young low-mass star is slight, but the metal
diffusion influence is obvious. The metal diffusion leads the models to have
much higher temperature in the radiation interior, correspondingly the higher
sound speed in the interior of the model, thereby the larger frequency and
spacings.


title:
A probabilistic key agreement scheme for sensor networks without key
  predistribution

abstract:
  The dynamic establishment of shared information (e.g. secret key) between two
entities is particularly important in networks with no pre-determined structure
such as wireless sensor networks (and in general wireless mobile ad-hoc
networks). In such networks, nodes establish and terminate communication
sessions dynamically with other nodes which may have never been encountered
before, in order to somehow exchange information which will enable them to
subsequently communicate in a secure manner. In this paper we give and
theoretically analyze a series of protocols that enables two entities that have
never encountered each other before to establish a shared piece of information
for use as a key in setting up a secure communication session with the aid of a
shared key encryption algorithm. These protocols do not require previous
pre-distribution of candidate keys or some other piece of information of
specialized form except a small seed value, from which the two entities can
produce arbitrarily long strings with many similarities.


title: Topological susceptibility in 2-flavor lattice QCD with fixed topology

abstract:
  We determine the topological susceptibility $ \chi_t $ in the trivial
topological sector generated by lattice simulations of two-flavor QCD with
overlap Dirac fermion, on a $16^3 \times 32$ lattice with lattice spacing
$\sim$ 0.12 fm, at six sea quark masses $m_q$ ranging from $m_s/6$ to $m_s$
(where $m_s$ is the physical strange quark mass). The $ \chi_t $ is extracted
from the plateau (at large time separation) of the time-correlation function of
the flavor-singlet pseudoscalar meson ($\eta'$), which arises from the finite
size effect due to fixed topology. In the small $m_q$ regime, our result of
$\chi_t$ is proportional to $m_q$ as expected from chiral effective theory.
Using the formula $\chi_t=m_q\Sigma/N_f$ by Leutwyler-Smilga, we obtain the
chiral condensate in $N_f=2$ QCD as $\Sigma^{\bar{\mathrm{MS}}}(\mathrm{2
GeV})=[252(5)(10) \mathrm{MeV}]^3 $, in good agreement with our previous result
obtained in the $\epsilon$-regime.


title:
Cohomology algebra of the orbit space of free circle group actions on
  lens spaces

abstract:
  Suppose that G=S^1 acts freely on a finitistic space X whose mod p cohomology
ring isomorphic to that of a lens space L^{2m-1}(p;q_1,...,q_m). In this paper,
we determine the mod p cohomology ring of the orbit space X/G. If the
characteristic class \alpha\belongs H^2(X/G;Z_p) of the S^1-bundle S--> X-->
X/G is nonzero, then mod p ndex of the action is deined to be the largest
integer n such that \alpha^n is nonzero. We also show that the mod p index of a
free action of S^1 on a lens space L^(2m-1)(p;q_1,...,q_m) is p-1, provided
that \alpha is nonzero.


title: Quotients of Banach spaces with the Daugavet property

abstract:
  We consider a general concept of Daugavet property with respect to a norming
subspace. This concept covers both the usual Daugavet property and its weak$^*$
analogue. We introduce and study analogues for narrow operators and rich
subspaces in this general setting and apply the results to show that a quotient
of $L_1[0,1]$ over an $\ell_1$-subspace can fail the Daugavet property. The
latter answers a question posed to us by A. Pelczynski in the negative.


title:
Cardinality heterogeneities in Web service composition: Issues and
  solutions

abstract:
  Data exchanges between Web services engaged in a composition raise several
heterogeneities. In this paper, we address the problem of data cardinality
heterogeneity in a composition. Firstly, we build a theoretical framework to
describe different aspects of Web services that relate to data cardinality, and
secondly, we solve this problem by developing a solution for cardinality
mediation based on constraint logic programming.


title:
A morphological comparison between giant radio halos and radio
  mini--halos in galaxy clusters

abstract:
  In this letter we present a morphological comparison between giant radio
halos and radio mini-halos in galaxy clusters based on radio--X-ray luminosity,
P_{1.4}-L_X, and radio luminosity-size, P_{1.4}-R_H, correlations. We report
evidence that P_{1.4}-L_X and P_{1.4}-R_H trends may also exist for
mini--halos: mini--halo clusters share the same region of giant halo clusters
in the (P_{1.4},L_X) plane, whereas they are clearly separated in the
(P_{1.4},R_H) plane. The synchrotron emissivity of mini-halos is found to be
more than 50 times larger than that of giant halos, implying a very efficient
process for their origins. By assuming a scenario of sporadical turbulent
particle re-acceleration for both giant and mini halos, we discuss basic
physical differences between these sources. Regardless of the origin of the
turbulence, a more efficient source of injection of particles, which eventually
takes part in the re-acceleration process, is required in mini-halos, and this
may result from the central radio galaxy or from proton-proton collisions in
the dense cool core regions.


title: An algorithm for weighted fractional matroid matching

abstract:
  Let M be a matroid on ground set E. A subset l of E is called a `line' when
its rank equals 1 or 2. Given a set L of lines, a `fractional matching' in
(M,L) is a nonnegative vector x indexed by the lines in L, that satisfies a
system of linear constraints, one for each flat of M. Fractional matchings were
introduced by Vande Vate, who showed that the set of fractional matchings is a
half-integer relaxation of the matroid matching polytope.
  It was shown by Chang et al. that a maximum size fractional matching can be
found in polynomial time. In this paper we give a polynomial time algorithm to
find for any given weights on the lines in L, a maximum weight fractional
matching.


title:
A Low-Complexity, Full-Rate, Full-Diversity 2 X 2 STBC with Golden
  Code's Coding Gain

abstract:
  This paper presents a low-ML-decoding-complexity, full-rate, full-diversity
space-time block code (STBC) for a 2 transmit antenna, 2 receive antenna
multiple-input multiple-output (MIMO) system, with coding gain equal to that of
the best and well known Golden code for any QAM constellation. Recently, two
codes have been proposed (by Paredes, Gershman and Alkhansari and by Sezginer
and Sari), which enjoy a lower decoding complexity relative to the Golden code,
but have lesser coding gain. The $2\times 2$ STBC presented in this paper has
lesser decoding complexity for non-square QAM constellations, compared with
that of the Golden code, while having the same decoding complexity for square
QAM constellations. Compared with the Paredes-Gershman-Alkhansari and
Sezginer-Sari codes, the proposed code has the same decoding complexity for
non-rectangular QAM constellations. Simulation results, which compare the
codeword error rate (CER) performance, are presented.


title: Distal actions and shifted convolution property

abstract:
  A locally compact group $G$ is said to have shifted convolution property
(abbr. as SCP) if for every regular Borel probability measure $\mu$ on $G$,
either $\sup_{x\in G} \mu ^n (Cx) \ra 0$ for all compact subsets $C$ of $G$, or
there exist $x\in G$ and a compact subgroup $K$ normalised by $x$ such that
$\mu^nx^{-n} \ra \omega_K$, the Haar measure on $K$. We first consider
distality of factor actions of distal actions. It is shown that this holds in
particular for factors under compact groups invariant under the action and for
factors under the connected component of identity. We then characterize groups
having SCP in terms of a readily verifiable condition on the conjugation action
(point-wise distality). This has some interesting corollaries to distality of
certain actions and Choquet Deny measures which actually motivated SCP and
point-wise distal groups. We also relate distality of actions on groups to that
of the extensions on the space of probability measures.


title: Role of coherence in resistance quantization

abstract:
  The quantization of resistances in the quantum Hall effect and ballistic
transport through quantum point contacts is compared with the quantization of
the charge relaxation resistance of a coherent mesoscopic capacitor. While the
former two require the existence of a perfectly transmitting channel, the
charge relaxation resistance remains quantized for arbitrary backscattering.
The quantum Hall effect and the quantum point contact require only local phase
coherence. In contrast quantization of the charge relaxation resistance
requires global phase coherence.