title:
Modifications of turbulence and turbulent transport associated with a
  bias-induced confinement transition in LAPD

abstract:
  Azimuthal flow is driven in the edge of the Large Plasma Device (LAPD) [W.
Gekelman, {\itshape et. al}, Rev. Sci. Instr. {\bfseries 62}, 2875 (1991)]
through biasing a section of the vacuum vessel relative to the plasma source
cathode. As the applied bias exceeds a threshold, a transition in radial
particle confinement is observed, evidenced by a dramatic steepening in the
density profile, similar to the L- to H-mode transition in toroidal confinement
devices. The threshold behavior and dynamic behavior of radial transport is
related to flow penetration and the degree of spatial overlap between the flow
shear and density gradient profiles. An investigation of the changes in
turbulence and turbulent particle transport associated with the confinement
transition is presented. Two-dimensional cross-correlation measurements show
that the spatial coherence of edge turbulence in LAPD changes significantly
with biasing. The azimuthal correlation in the turbulence increases
dramatically, while the radial correlation length is little altered. Turbulent
amplitude is reduced at the transition, particularly in electric field
fluctuations, but the dominant change observed is in the cross-phase between
density and electric field fluctuations. The changes in cross-phase lead to a
suppression and then apparent reversal of turbulent particle flux as the
threshold is exceeded.


title: Molecular Electronics: Effect of external electric field

abstract:
  The effect of electric field, applied on systems in the nanoscale regime has
attracted a lot of research in recent times. We highlight some of the recent
results in the field of single molecule electronics and then move on to focus
on some of our own results in this area. We have first shown how important it
is to obtain the spatial profile of the external bias potential across the
system, and how this would change in the presence of electron-electron
interactions. We have also studied different kinds of insulators in the
presence of the spatially varying external bias, and have explicitly shown that
a two sublattice structure, caused either by a lattice distortion, or by the
presence of substituents with strong dipolar nature, can result in negative
differential resistance (NDR) in the transport characteristics. We also find
this to be true in case of correlated insulators. Additionally, we have shown
clear NDR behavior in a correlated double quantum dot by tuning the
electron-electron interaction strength in the system.


title:
On the adjustment coefficient, drawdowns and Lundberg-type bounds for
  random walk

abstract:
  Consider a random walk whose (light-tailed) increments have positive mean.
Lower and upper bounds are provided for the expected maximal value of the
random walk until it experiences a given drawdown d. These bounds, related to
the Calmar ratio in Finance, are of the form (exp{alpha d}-1)/alpha and (K
exp{alpha d}-1)/alpha for some K>1, in terms of the adjustment coefficient
alpha (E[exp{-alpha X}]=1) of the insurance risk literature. Its inverse
1/alpha has been recently derived by Aumann and Serrano as an index of
riskiness of the random variable X. This article also complements the Lundberg
exponential stochastic upper bound and the Cramer-Lundberg approximation for
the expected minimum of the random walk, with an exponential stochastic lower
bound. The tail probability bounds are of the form C exp{-alpha x} and
exp{-alpha x} respectively, for some 1/K < C < 1. Our treatment of the problem
involves Skorokhod embeddings of random walks in Martingales, especially via
the Azema-Yor and Dubins stopping times, adapted from standard Brownian Motion
to exponential Martingales.


title:
Multiplets Matter: The Electronic Structure of Rare-Earth Semiconductors
  and Semimetals

abstract:
  We demonstrate that a theoretical framework fully incorporating intra-atomic
correlations and multiplet structure of the localized 4f states is required in
order to capture the essential physics of rare-earth semiconductors and
semimetals. We focus in particular on the rare-earth semimetal erbium arsenide
(ErAs), for which effective one-electron approaches fail to provide a
consistent picture of both high and low-energy electronic states. We treat the
many-body states of the Er 4f shell within an atomic approximation in the
framework of dynamical mean-field theory. Our results for the magnetic-field
dependence of the 4f local moment, the influence of multiplets on the
photoemission spectrum, and the exchange splitting of the Fermi surface pockets
as measured from Shubnikov-de Haas oscillations, are found to be in good
agreement with experimental results.


title: On a New Form of Quantum Mechanics

abstract:
  We propose a new form of nonrelativistic quantum mechanics which is based on
a quantum version of the action principle.


title: Exact solitons in the nonlocal Gordon equation

abstract:
  We find exact monotonic solitons in the nonlocal Gordon equation
u_{tt}=J*u-u-f(u), in the case J(x)=1/2 e^{-|x|}. To this end we come up with
an inverse method, which gives a representation of the set of nonlinearities
admitting such solutions. We also study u''''+{\l}u''-sin u=0, which arises
from the above when we write it in traveling wave coordinates and pass to a
certain limit. For this equation we find an exact 4\pi-kink and show the
nonexistence of 2\pi-kinks, using the analytic continuation method of Amick and
McLeod.


title: Comparative study of the electron conduction in azulene and naphthalene

abstract:
  We have studied the feasibility of electron conduction in azulene molecule
and compared with that in its isomer naphthalene. We have used non-equilibrium
Green's function formalism to measure the current in our systems as a response
of the external electric field. Parallely we have performed the Gaussian
calculations with electric field in the same bias window to observe the impact
of external bias on the wave functions of the systems. We have found that, the
conduction of azulene is higher than that of naphthalene inspite of its
intrinsic donor-acceptor property, which leads a system to more insulating
state. Due to stabilization through charge transfer the azulene system can be
fabricated as a very effective molecular wire. Our calculations shows the
possibility of huge device application of azulene in nano-scale instruments.


title:
Controlling Irreversibility and Directional Flow of Light with Atomic
  Motion

abstract:
  The Doppler effect of moving atoms can create irreversibility of light. We
show that the laser field in electromagnetic induced transparency (EIT) scheme
with atomic motion can control the directional propagation of two
counter-propagating probe fields in atomic gas cell. The quantum coherence
effect serves as an optical transistor. Interference of the two output fields
from the cell shows useful feature for determining the mean atomic velocity and
can be useful as quantum velocimeter. We also find that the sign of the
dispersive phase in EIT has a unique property, which helps to explain certain
features in the interference.


title:
Discovery of thermal X-ray emission in the Supernova Remnant G337.8-0.1
  (Kes 41)

abstract:
  We report here on the first detection at X-ray wavelengths of the Supernova
Remnant (SNR) G337.8-0.1, carried out with the XMM-Newton Observatory. Using
the X-ray observations, we studied the X-ray morphology of the remnant at
different energy ranges, analysed the spectral properties and investigated a
possible variable behavior. The SNR shows a diffuse filled-center structure in
the X-ray region with an absence of a compact source in its center. We find a
high column density of N_H > 6.9 * 10^{22} cm^{-2}, which supports a relatively
distant location (d > 7 kpc). The X-ray spectrum exhibits emission lines,
indicating that the X-ray emission has a thin thermal plasma origin, and is
well represented by a non-equilibrium ionization (NEI) plasma model. The X-ray
characteristics and well-known radio parameters show that G337.8-0.1 belongs to
the emerging class of mixed-morphology (MM) SNRs.


title:
Ultrametricity and clustering of states in spin glasses: A
  one-dimensional view

abstract:
  We present results from Monte Carlo simulations to test for ultrametricity
and clustering properties in spin-glass models. By using a one-dimensional
Ising spin glass with random power-law interactions where the universality
class of the model can be tuned by changing the power-law exponent, we find
signatures of ultrametric behavior both in the mean-field and non-mean-field
universality classes for large linear system sizes. Furthermore, we confirm the
existence of nontrivial connected components in phase space via a clustering
analysis of configurations.


title: X-rays of currents and projections of forms

abstract:
  We introduce and study a new Radon-like transform that averages projected
differential p-forms in R^n over affine (n-k)-planes. We then prove an explicit
inversion formula for our transform on the space of rapidly-decaying smooth
p-forms. Our transform differs from the one in Gelfand-Graev-Shapiro. Moreover,
if it can be extended to a somewhat larger space of p-forms, our inversion
formula will allow the synthesis of any rapidly-decaying smooth p-form on R^n
as a (continuous) superposition of pullbacks from p-forms on k-dimensional
subspaces. In turn, such synthesis implies an explicit formula (which we
derive) for reconstructing compactly supported currents in R^n (e.g., compact
oriented k-dimensional subvarieties) from their oriented projections onto
k-planes.


title:
Re-Thinking Schroedinger Boundary Conditions: the Simple Rotator is Not
  Simple

abstract:
  A contradiction arises when applying standard boundary conditions to a simple
quantum rotator with a single coordinate. New boundary conditions for the
Schroedinger equation are proposed that involve only gauge invariant
quantities, and that can be applied beyond the immediate problem. The use of
gauge invariant boundary conditions has important consequence for energy flow
in or out of a simple rotator.


title:
Phase Transition in Space: How Far Does a Symmetry Bend Before It
  Breaks?

abstract:
  We extend the theory of symmetry breaking dynamics in non-equilibrium second
order phase transitions known as the Kibble-Zurek mechanism (KZM) to
transitions where the change of phase occurs not in time, but in space. This
can be due to a time-independent spatial variation of a field that imposes a
phase with one symmetry to the left of where it attains critical value, while
allowing spontaneous symmetry breaking to the right of that critical
borderline. Topological defects need not form in such a situation. We show,
however, that the size, in space, of the ``scar'' over which the order
parameter adjusts as it ``bends'' interpolating between the phases with
different symmetry follows from a KZM - like approach. As we illustrate on the
example of a transverse quantum Ising model, in quantum phase transitions this
spatial scale -- the size of the scar -- is directly reflected in the energy
spectrum of the system: In particular, it determines the size of the energy
gap.


title: Hyperpolar homogeneous foliations on symmetric spaces of noncompact type

abstract:
  A foliation on a Riemannian manifold is hyperpolar if it admits a flat
section, that is, a connected closed flat submanifold that intersects each leaf
of the foliation orthogonally. In this article we classify the hyperpolar
homogeneous foliations on every Riemannian symmetric space of noncompact type.


title: A curious result related to Kempner's series

abstract:
  It is well known since A. J. Kempner's work that the series of the
reciprocals of the positive integers whose the decimal representation does not
contain any digit 9, is convergent. This result was extended by F. Irwin and
others to deal with the series of the reciprocals of the positive integers
whose the decimal representation contains only a limited quantity of each digit
of a given nonempty set of digits. Actually, such series are known to be all
convergent. Here, letting $S^{(r)}$ $(r \in \mathbb{N})$ denote the series of
the reciprocal of the positive integers whose the decimal representation
contains the digit 9 exactly $r$ times, the impressive obtained result is that
$S^{(r)}$ tends to $10 \log{10}$ as $r$ tends to infinity!


title: On the support of the free Lie algebra: the Sch\"utzenberger problems

abstract:
  M.-P. Sch\"utzenberger asked to determine the support of the free Lie algebra
${\mathcal L}_{{\mathbb Z}_{m}}(A)$ on a finite alphabet $A$ over the ring
${\mathbb Z}_{m}$ of integers $\bmod m$ and all the corresponding pairs of twin
and anti-twin words, i.e., words that appear with equal (resp. opposite)
coefficients in each Lie polynomial. We study these problems using the adjoint
endomorphism $l^{*}$ of the left normed Lie bracketing $l$ of ${\mathcal
L}_{{\mathbb Z}_{m}}(A)$. Calculating $l^{*}(w)$ via all factors of a given
word $w$ of fixed length and the shuffle product, we recover the result of
Duchamp and Thibon $(1989)$ for the support of the free Lie ring in a much more
natural way. We rephrase these problems, for words of length $n$, in terms of
the action of the left normed multi-linear Lie bracketing $l_{n}$ of ${\mathcal
L}_{{\mathbb Z}_{m}}(A)$ - viewed as an element of the group ring of the
symmetric group ${\mathcal S}_{n}$ - on $\lambda$-tabloids, where $\lambda$ is
a partition of $n$. For words $w$ in two letters, represented by a subset $I$
of $[n] = \{1, 2, ..., n \}$, this leads us to the {\em Pascal descent
polynomial} $p_{n}(I)$, a particular commutative multi-linear polynomial which
equals to a signed binomial coefficient when $|I| = 1$ and allows us to obtain
a sufficient condition on $n$ and $I$ in order that $w$ lies in ${\mathcal
L}_{{\mathbb Z}_{m}}(A)$. We also have a particular conjecture for twin and
anti-twin words for the free Lie ring and show that it is enough to be checked
for $|A| = 2$.


title: Testing the Nullspace Property using Semidefinite Programming

abstract:
  Recent results in compressed sensing show that, under certain conditions, the
sparsest solution to an underdetermined set of linear equations can be
recovered by solving a linear program. These results either rely on computing
sparse eigenvalues of the design matrix or on properties of its nullspace. So
far, no tractable algorithm is known to test these conditions and most current
results rely on asymptotic properties of random matrices. Given a matrix A, we
use semidefinite relaxation techniques to test the nullspace property on A and
show on some numerical examples that these relaxation bounds can prove perfect
recovery of sparse solutions with relatively high cardinality.


title: Dynamics of gene expression under feedback

abstract:
  Gene expression is a stochastic process governed by the presence of specific
transcription factors. Here we study the dynamics of gene expression in the
presence of feedback, where a gene regulates its own expression. The nonlinear
coupling between input and output of gene expression can generate a dynamics
different from simple scenarios such as the Poisson process. This is
exemplified by our findings for the time intervals over which genes are
transcriptionally active and inactive. We apply our results to the lac system
in E. coli, where parametric inference on experimental data results in a broad
distribution of gene activity intervals.


title: Integral Representaion for L-functions for GSp(4)xGL(2)

abstract:
  Let pi be a cuspidal, automorphic representation of GSp(4) attached to a
Siegel modular form of degree 2. We refine the method of Furusawa to obtain an
integral representation for the degree-8 L-function L(s,pi x tau), where tau
runs through certain cuspidal, automorphic representation of GL(2). Our
calculations include the case of square-free level for the p-adic components of
tau, and a wide class of archimedean types including Maass forms. As an
application we obtain a special value result for L(s,pi x tau).


title: Other Beyond Standard Model Searches at the Tevatron

abstract:
  We present the results of searches for non-standard model phenomena, with
focus on signature-based searches and searches driven by non-supersymmetry
(non-SUSY) models. The analyses use 1.0--2.5 fb-1 of data from ppbar collisions
at sqrt(s)=1.96 TeV collected with the CDF and D0 detectors at the Fermilab
Tevatron. No significant excess in data has been observed. We report on the
event counts, kinematic distributions, and limits on selected model parameters.


title: Will the announced influenza pandemic really happen?

abstract:
  We propose two simple probability models to compute the probability of an
influenza pandemic. Under a random walk model the probability that all
pandemics between times 0 and 300 occur by time 150 is 1/2. Under a Poisson
model with mean inter arrival time of 30 years the probability that no pandemic
occurs during at least 60 years is 14%. These probabilities are much higher
than generally perceived. So yes the next influenza pandemic will happen but
maybe much later than generally thought.


title: Alignment of the LHCb Vertex Locator

abstract:
  LHCb will commence data taking as the first dedicated heavy flavour
experiment at a hadron collider in 2008. A very high hit precision from its
vertex detector (VELO) is essential to meet the tight requirements of vertex
reconstruction in B-physics. The single hit precision of the VELO is better
than 10 micron. However, the VELO is operated only 8 mm from the beam and must
be retracted and reinserted each LHC fill. Hence, the detector places unique
demands on its alignment algorithm. The partially assembled VELO system has
already been tested in a beam test. The novel software alignment methods are
presented together with their interplay with the metrology measurements.
Results from Monte Carlo simulation studies are discussed and recent beam test
results are shown that prove the method's precision at the micron level.


title:
The X-ray cavities, filaments and cold fronts in the core of the galaxy
  group NGC 5044

abstract:
  We present a two-dimensional analysis of the bright nearby galaxy group NGC
5044 using the currently available Chandra and XMM data. In the inner 10 kpc a
pair of cavities are evident together with a set of bright X-ray filaments. If
the cavities are interpreted as gas displaced by relativistic plasma inflated
by an AGN, even in the absence of extended 1.4 GHz emission, this would be
consistent with a recent outburst as also indicated by the extent of dust and
H_alpha emission. The soft X-ray filaments coincident with H_alpha and dust
emission are cooler than the ones which do not correlate with optical and
infrared emission. We suggest that dust-aided cooling contributes to form warm
(T =10^4 K) gas, emitting H_alpha radiation. At 31 kpc and 67 kpc a pair of
cold fronts are present, indicative of sloshing due to a dynamical perturbation
caused by accretion of a less massive group, also suggested by the peculiar
velocity of the brightest galaxy NGC 5044 with respect to the mean group
velocity.


title:
Charge order in LuFe2O4: antiferroelectric ground state and coupling to
  magnetism

abstract:
  X-ray scattering by multiferroic LuFe2O4 is reported. Below 320 K,
superstructure reflections indicate an incommensurate charge order with
propagation close to (1/3,1/3,3/2). The corresponding charge configuration,
also found by electronic structure calculations as most stable, contains polar
Fe/O double-layers with antiferroelectric stacking. Diffuse scattering at 360
K, with (1/3,1/3,0) propagation, indicates ferroelectric short-range
correlations between neighboring double-layers. The temperature dependence of
the incommensuration indicates that charge order and magnetism are coupled.


title: The Role of Structure in the Protein Dynamical Transition

abstract:
  The protein dynamical transition is investigated as a function of protein
structure using terahertz time domain spectroscopy (THz-TDS). Measurements
performed for native state and denatured hen egg white lysozyme (HEWL) show
that protein structure is not necessary for the dynamical transition. We find
the temperature dependence follows activated behavior and there is no evidence
of a fragile to strong transition. Measurements of short chain poly alanine
show a dynamical transition down to penta-alanine, however no transition is
observed for di-alanine or tri-alanine. These measurements demonstrate that the
temperature dependence arises strictly from the interaction of the side chains
with the solvent. The lack of a transition for shorter chain polypeptides may
indicate the temperature dependence arises from a net ordering of the adjacent
water which scales with the length of the polypeptide chain.


title: A Kinetic Model for Grain Growth

abstract:
  We provide a well-posedness analysis of a kinetic model for grain growth
introduced by Fradkov which is based on the von Neumann-Mullins law. The model
consists of an infinite number of transport equations with a tri-diagonal
coupling modelling topological changes in the grain configuration.
Self-consistency of this kinetic model is achieved by introducing a coupling
weight which leads to a nonlinear and nonlocal system of equations.
  We prove existence of solutions by approximation with finite dimensional
systems. Key ingredients in passing to the limit are suitable super-solutions,
a bound from below on the total mass, and a tightness estimate which ensures
that no mass is transported to infinity in finite time.


title: Mean-Field Interacting Boson Random Point Fields in Weak Harmonic Traps

abstract:
  A model of the mean-field interacting boson gas trapped by a weak harmonic
potential is considered by the \textit{boson random point fields} methods. We
prove that in the Weak Harmonic Trap (WHT) limit there are two phases
distinguished by the boson condensation and by a different behaviour of the
local particle density. For chemical potentials less than a certain critical
value, the resulting Random Point Field (RPF) coincides with the usual boson
RPF, which corresponds to a non-interacting (ideal) boson gas. For the chemical
potentials greater than the critical value, the boson RPF describes a divergent
(local) density, which is due to \textit{localization} of the macroscopic
number of condensed particles. Notice that it is this kind of transition that
observed in experiments producing the Bose-Einstein Condensation in traps.


title:
Classical theory of second-harmonic generation from magnetic
  metamaterials

abstract:
  Strong second-harmonic generation has recently been experimentally observed
from metamaterials consisting of periodic arrays of metal split ring resonators
with an effective negative magnetic permeability [Science, 313, 502 (2006)]. To
explore the underlying physical mechanism, a classical model derived from
microscopic theory is employed here. The quasi-free electrons inside the metal
are approximated as a classical Coulomb-interacting electron gas, and their
motion under the excitation of an external electromagnetic field is described
by the cold-plasma wave equations. Through numerical simulations, it is
demonstrated that the microscopic theory includes the dominant physical
mechanisms bothqualitatively and quantitatively.


title:
LHCb VELO software alignment, Part III: the alignment of the relative
  sensor positions

abstract:
  The LHCb Vertex Locator contains 42 silicon sensor modules. Each module has
two silicon sensors. A method for determining the relative alignment of the
silicon sensors within each module from data is presented. The software
implementation details are discussed. Monte-Carlo simulation studies are
described that demonstrate an alignment precision of 1.3 micron is obtained in
the sensor plane.


title:
Parametric down-conversion from a wave-equations approach: geometry and
  absolute brightness

abstract:
  Using the approach of coupled wave equations, we consider spontaneous
parametric down-conversion (SPDC) in the narrow-band regime and its
relationship to classical nonlinear processes such as sum-frequency generation.
We find simple expressions in terms of mode overlap integrals for the absolute
pair production rate into single spatial modes, and simple relationships
between the efficiencies of the classical and quantum processes. The results,
obtained with Green function techniques, are not specific to any geometry or
nonlinear crystal. The theory is applied to both degenerate and non-degenerate
SPDC. We also find a time-domain expression for the correlation function
between filtered signal and idler fields.


title:
Learning from Physics Education Research: Lessons for Economics
  Education

abstract:
  We believe that economists have much to learn from educational research
practices and related pedagogical innovations in other disciplines, in
particular physics education. In this paper we identify three key features of
physics education research that distinguish it from economics education
research - (1) the intentional grounding of physics education research in
learning science principles, (2) a shared conceptual research framework focused
on how students learn physics concepts, and (3) a cumulative process of
knowledge-building in the discipline - and describe their influence on new
teaching pedagogies, instructional activities, and curricular design in physics
education. In addition, we highlight four specific examples of successful
pedagogical innovations drawn from physics education - context-rich problems,
concept tests, just-in-time teaching, and interactive lecture demonstrations -
and illustrate how these practices can be adapted for economic education.


title:
On the extension of twisted holomorphic sections of singular hermitian
  line bundles

abstract:
  We prove a sharp Ohsawa-Takegoshi-Manivel type extension result for twisted
holomorphic sections of singular hermitian line bundles over almost Stein
manifolds. We establish as corollaries some extension results for pluri-twisted
holomorphic sections of singular hermitian line bundles over projective
manifolds.


title:
Exponential equilibration by slow cooling in the planar
  random-anisotropy magnet: experiments and simulations

abstract:
  Neutron measurements of the equilibration of the staggered magnetization in
DyAs(0.35)V(0.65)O4 are compared with Monte Carlo simulations of spin dynamics
in a planar random-anisotropy magnet. The simulation results are in agreement
with striking observed relaxation phenomena: when cooled rapidly to a low
temperature no magnetic ordering is observed, but when cooled in small steps an
ordered magnetic moment appears which is found to equilibrate exponentially
with time at temperatures through and below the transition temperature. In
contrast to the freezing of spins in other random systems, the time scale of
the relaxation in this system does not increase significantly even at the
lowest temperatures.


title: The Gravitational Field of a Radiating Electromagnetic Dipole

abstract:
  We begin with the time-dependent electric and magnetic dipole solution of
Maxwell's equations in Minkowski space. This Maxwell field is then used to
determine the behavior of the gravitational field (the Weyl tensor) as a
second-order perturbation off of the Minkowski background. From the Weyl tensor
we go on and find the spin-coefficients and the full metric in this
approximation. The physical meaning of many of the relations is discussed. In
particular we can identify the conservation law of angular momentum that
contains an angular momentum flux term.


title: Hadron Structure with Dimuon Production

abstract:
  Dimuon production has been studied in a series of fixed-target experiments at
Fermilab during the last two decades. Highlights from these experiments,
together wih recent results from the Fermilab E866 experiment, are presented.
Future prospects for studying the parton distributions in the nucleons and
nuclei using dimuon production at Fermilab and J-PARC are also discussed.


title: Casimir effect with dynamical matter on thin mirrors

abstract:
  We calculate the Casimir energy for scalar and gauge fields in interaction
with zero-width mirrors, including quantum effects due to the matter fields
inside the mirrors. We consider models where those fields are either scalar or
fermionic, obtaining general expressions for the energy as a function of the
vacuum field 1PI function. We also study, within the frame of a concrete model,
the role of the dissipation induced by those degrees of freedom, showing that,
after integration of the matter fields, the effective theory for the
electromagnetic field contains modes with complex energies. As for the case of
Lifshitz formula, we show that the formal result obtained by neglecting
dissipation coincides with the correct result that comes from the quantum
fluctuations of both bulk and matter fields.


title:
Asymptotic normality of the deconvolution kernel density estimator under
  the vanishing error variance

abstract:
  Let $X_1,...,X_n$ be i.i.d. observations, where $X_i=Y_i+\sigma_n Z_i$ and
the $Y$'s and $Z$'s are independent. Assume that the $Y$'s are unobservable and
that they have the density $f$ and also that the $Z$'s have a known density
$k.$ Furthermore, let $\sigma_n$ depend on $n$ and let $\sigma_n\to 0$ as
$n\to\infty.$ We consider the deconvolution problem, i.e. the problem of
estimation of the density $f$ based on the sample $X_1,...,X_n.$ A popular
estimator of $f$ in this setting is the deconvolution kernel density estimator.
We derive its asymptotic normality under two different assumptions on the
relation between the sequence $\sigma_n$ and the sequence of bandwidths $h_n.$
We also consider several simulation examples which illustrate different types
of asymptotics corresponding to the derived theoretical results and which show
that there exist situations where models with $\sigma_n\to 0$ have to be
preferred to the models with fixed $\sigma.$


title: Recognition of generalized network matrices

abstract:
  In this PhD thesis, we deal with binet matrices, an extension of network
matrices. The main result of this thesis is the following. A rational matrix A
of size n times m can be tested for being binet in time O(n^6 m). If A is
binet, our algorithm outputs a nonsingular matrix B and a matrix N such that [B
N] is the node-edge incidence matrix of a bidirected graph (of full row rank)
and A=B^{-1} N.
  Furthermore, we provide some results about Camion bases. For a matrix M of
size n times m', we present a new characterization of Camion bases of M,
whenever M is the node-edge incidence matrix of a connected digraph (with one
row removed). Then, a general characterization of Camion bases as well as a
recognition procedure which runs in O(n^2m') are given. An algorithm which
finds a Camion basis is also presented. For totally unimodular matrices, it is
proven to run in time O((nm)^2) where m=m'-n.
  The last result concerns specific network matrices. We give a
characterization of nonnegative {r,s}-noncorelated network matrices, where r
and s are two given row indexes. It also results a polynomial recognition
algorithm for these matrices.


title: Outburst Morphology in the Soft X-ray Transient Aquila X-1

abstract:
  We present optical and near-IR (OIR) observations of the major outbursts of
the neutron star soft X-ray transient binary system Aquila X-1, from summer
1998 -- fall 2007. The major outbursts of the source over the observed timespan
seem to exhibit two main types of light curve morphologies, (a) the classical
Fast-Rise and Exponential-Decay (FRED) type outburst seen in many soft X-ray
transients and (b) the Low-Intensity State (LIS) where the
optical-to-soft-X-ray flux ratio is much higher than that seen during a FRED.
Thus there is no single correlation between the optical (R-band) and soft X-ray
(1.5-12 keV, as seen by the ASM onboard RXTE) fluxes even within the hard state
for Aquila X-1, suggesting that LISs and FREDs have fundamentally different
accretion flow properties. Time evolution of the OIR fluxes during the major
LIS and FRED outbursts is compatible with thermal heating of the irradiated
outer accretion disk. No signature of X-ray spectral state changes or any
compact jet are seen in the OIR, showing that the OIR color-magnitude diagram
(CMD) can be used as a diagnostic tool to separate thermal and non-thermal
radiation from X-ray binaries where orbital and physical parameters of the
system are reasonably well known. We suggest that the LIS may be caused by
truncation of the inner disk in a relatively high mass accretion state,
possibly due to matter being diverted into a weak outflow.


title: A geometric interpretation of Stanley's monotonicity theorem

abstract:
  We present a new geometric proof of Stanley's monotonicity theorem for
lattice polytopes, using an interpretation of $\delta$-polynomials of lattice
polytopes in terms of orbifold Chow rings.


title:
Topological obstructions to embedding of a matrix algebra bundle into a
  trivial one

abstract:
  In the present paper we describe topological obstructions to embedding of a
(complex) matrix algebra bundle into a trivial one under some additional
arithmetic condition on their dimensions. We explain a relation between this
problem and some principal bundles with structure groupoid. Finally, we briefly
discuss a relation of our results to the twisted K-theory.


title:
Stellar population gradients in early-type cluster galaxies with VIMOS
  IFU

abstract:
  We present results from a pilot study of radial stellar population trends in
early-type galaxies using the VLT VIMOS integral field unit (IFU). We observe
twelve galaxies in the cluster Abell 3389 (z~0.027). For each galaxy, we
measure 22 line-strength indices in multiple radial bins out to at least the
effective radius. We derive stellar population parameters using a grid
inversion technique, and calculate the radial gradients in age, metallcity and
alpha-abundance. Generally, the galaxies in our sample have flat radial trends
in age and [alpha/Fe], but negative gradients in [Z/H] (-0.20 +/- 0.05 dex).
Combining our targets with two similar, long-slit studies to increase sample
size, we find that the gradients are not correlated with the central velocity
dispersion or K-band luminosity (both proxies for galaxy mass). However, we
find that the age and metallicity gradients are both anti-correlated with their
respective central values (to > 4 sigma), such that galaxies with young cores
have steeper positive age gradients, and those with metal-rich centres have
strong negative [Z/H] gradients.


title: Remarks on the McKay Conjecture

abstract:
  The McKay Conjecture (MC) asserts the existence of a bijection between the
(inequivalent) complex irreducible representations of degree coprime to $p$
($p$ a prime) of a finite group $G$ and those of the subgroup $N$, the
normalizer of Sylow $p$-subgroup. In this paper we observe that MC implies the
existence of analogous bijections involving various pairs of algebras,
including certain crossed products, and that MC is \emph{equivalent} to the
analogous statement for (twisted) quantum doubles. Using standard conjectures
in orbifold conformal field theory, MC is \emph{equivalent} to parallel
statements about holomorphic orbifolds $V^G, V^N$. There is a uniform
formulation of MC covering these different situations which involves quantum
dimensions of objects in pairs of ribbon fusion categories.


title:
Microphysical dissipation, turbulence and magnetic fields in
  hyper-accreting discs

abstract:
  Hyper-accreting discs occur in compact-object mergers and collapsars, and may
power gamma-ray bursts (GRBs). We calculate the microscopic viscosity and
resistivity of plasma in these discs, and discuss the implications for their
global structure and evolution. In the neutrino-cooled innermost regions, the
viscosity is provided mainly by mildly degenerate electrons, while the
resistivity is modified from the Spitzer value due to the effects of both
relativity and degeneracy. The plasma behaves as an almost ideal MHD fluid.
Among the non-ideal MHD effects the Hall term is relatively the most important,
while the magnetic Prandtl number, Pr (the ratio of viscosity to resistivity),
is typically larger than unity: 10 < Pr < 6000. The outer radiatively
inefficient regions also display high Pr. Numerical simulations of the
magneto-rotational instability indicate that the saturation level and angular
momentum transport efficiency may be greatly enhanced at high Pr. If this
behaviour persists in the presence of a strong Hall effect we would expect that
hyper-accreting discs should be strongly magnetised and highly variable. The
expulsion of magnetic field that cannot be dissipated at small scales may also
favour a magnetic outflow. We note the similaries between the Prandtl number in
hyper-accreting discs and X-ray binary discs, which suggests that a comparison
between late-time activity in GRBs and X-ray binary accretion states may be
fruitful. Our results imply that the behavior of high Prandtl number MHD flows
needs to be considered in studies of hyper-accreting discs.


title: Two new diagnostics of dark energy

abstract:
  We introduce two new diagnostics of dark energy (DE). The first, Om, is a
combination of the Hubble parameter and the cosmological redshift and provides
a "null test" of dark energy being a cosmological constant. Namely, if the
value of Om(z) is the same at different redshifts, then DE is exactly
cosmological constant. The slope of Om(z) can differentiate between different
models of dark energy even if the value of the matter density is not accurately
known. For DE with an unevolving equation of state, a positive slope of Om(z)
is suggestive of Phantom (w < -1) while a negative slope indicates Quintessence
(w > -1). The second diagnostic, "acceleration probe"(q-probe), is the mean
value of the deceleration parameter over a small redshift range. It can be used
to determine the cosmological redshift at which the universe began to
accelerate, again without reference to the current value of the matter density.
We apply the "Om" and "q-probe" diagnostics to the Union data set of type Ia
supernovae combined with recent data from the cosmic microwave background
(WMAP5) and baryon acoustic oscillations.


title: Unity fidelity multiple teleportation using partially entangled states

abstract:
  We show that the recent multiple teleportation protocol (MTP) presented in
Ref. [Phys. Rev. Lett. 100, 110503 (2008)] is not restricted to the
Knill-Laflamme-Milburn (KLM) scheme. Rather, we show that MTP is quite general
and can be implemented using whatever teleportation scheme at hand. We also
present two new MTP's which are more efficient than the original proposal,
requiring just half the number of teleportations of the original scheme to
achieve at least the same probability of success. One of the protocols,
however, employs less entanglement than all the previous ones yielding,
surprisingly, the greatest probability of success.


title: HI Clouds in the Lower Halo: I. The Galactic All-Sky Survey Pilot Region

abstract:
  We have detected over 400 HI clouds in the lower halo of the Galaxy within
the pilot region of the Galactic All-Sky Survey (GASS), a region of the fourth
quadrant that spans 18 degrees in longitude, 40 degrees in latitude and is
centered on the Galactic equator. These clouds have a median peak brightness
temperature of 0.6 K, a median velocity width of 12.8 km/s, and angular sizes
<1 degree. The motion of these clouds is dominated by Galactic rotation with a
random cloud-to-cloud velocity dispersion of 18 km/s. A sample of clouds likely
to be near tangent points was analyzed in detail. These clouds have radii on
the order of 30 pc and a median HI mass of 630 Msun. The population has a
vertical scale height of 400 pc and is concentrated in Galactocentric radius,
peaking at R=3.8 kpc. This confined structure suggests that the clouds are
linked to spiral features, while morphological evidence that many clouds are
aligned with loops and filaments is suggestive of a relationship with star
formation. The clouds might result from supernovae and stellar winds in the
form of fragmenting shells and gas that has been pushed into the halo rather
than from a galactic fountain.


title:
Clustering of Luminous Red Galaxies IV: Baryon Acoustic Peak in the
  Line-of-Sight Direction and a Direct Measurement of H(z)

abstract:
  We study the clustering of LRG galaxies in the latest spectroscopic SDSS data
releases, DR6 and DR7, which sample over 1 Gpc^3/h^3 to z=0.47. The 2-point
correlation function $\xisp$ is estimated as a function of perpendicular
$\sigma$ and line-of-sight $\pi$ (radial) directions. We find a significant
detection of a peak at $r\simeq 110$Mpc/h, which shows as a circular ring in
the $\sigma-\pi$ plane. There is also significant evidence for a peak along the
radial direction whose shape is consistent with its originating from the
recombination-epoch baryon acoustic oscillations (BAO). A $\xisp$ model with no
radial BAO peak is disfavored at $3.2\sigma$, whereas a model with no
magnification bias is disfavored at $2\sigma$. The radial data enable, for the
first time, a direct measurement of the Hubble parameter $H(z)$ as a function
of redshift. This is independent from earlier BAO measurements which used the
spherically averaged (monopole) correlation to constrain an integral of $H(z)$.
Using the BAO peak position as a standard ruler in the radial direction, we
find: $H(z=0.24)= 79.69 \pm 2.32 (\pm 1.29)$ km/s/Mpc for z=0.15-0.30 and
$H(z=0.43)= 86.45 \pm 3.27 (\pm 1.69)$ km/s/Mpc for $z=0.40-0.47$. The first
error is a model independent statistical estimation and the second accounts for
systematics both in the measurements and in the model. For the full sample,
$z=0.15-0.47$, we find $H(z=0.34)= 83.80 \pm 2.96 (\pm 1.59)$ km/s/Mpc.


title: Scalar spin chirality and quantum Hall effect on a triangular lattice

abstract:
  We study the Kondo Lattice and Hubbard models on a triangular lattice for
band filling factor 3/4. We show that a simple non-coplanar chiral spin
ordering (scalar spin chirality) is naturally realized in both models due to
perfect nesting of the Fermi surface. The resulting triple-Q magnetic ordering
is a natural counterpart of the collinear Neel ordering of the half-filled
square lattice Hubbard model. We show that the obtained chiral phase exhibits a
spontaneous quantum Hall-effect with sigma_{xy}= e^2/h.


title: An MHD Gadget for cosmological simulations

abstract:
  Various radio observations have showed that the hot atmospheres of galaxy
clusters are magnetized. However, our understanding of the origin of these
magnetic fields, their implications on structure formation and their interplay
with the dynamics of the cluster atmosphere, especially in the centers of
galaxy clusters is still very limited. In preparation to the upcoming new
generation of radio telescopes (like EVLA, LWA, LOFAR and SKA), a huge effort
is being made to learn more about cosmological magnetic fields from the
observational perspective. Here we present the implementation of magneto
hydrodynamics in the cosmological SPH code GADGET. We discuss the details of
the implementation and various schemes to suppress numerical instabilities as
well as regularization schemes, in the context of cosmological simulations. The
performance of the SPH MHD code is demonstrated in various one and two
dimensional test problems, which we performed if a fully, three dimensional
setup to test the code under realistic circumstances. Comparing with solutions
obtained with ATHENA, we find excellent agreement with our SPH MHD
implementation. Finally we apply our SPH MHD implementation to forming galaxy
clusters within a large, cosmological box. Performing a resolution study we
demonstrate the robustness of the predicted shape of the magnetic field
profiles in galaxy clusters, which is in good agreement with previous studies.


title:
IFU observations of the GRB 980425/SN 1998bw host galaxy: emission line
  ratios in GRB regions

abstract:
  The collapsar model predicts that the progenitors of Gamma-ray Bursts (GRBs)
are metal poor in Fe group elements. The existence of low metallicity stellar
populations could manifest itself through special characteristics of the
immediate environment of the GRB site in the host galaxy. We analyse the strong
emission lines from the sub-luminous host galaxy of GRB 980425, which showed
the first connection with a supernova explosion (SN 1998bw). The host has a
sufficient size to allow detailed resolved spectroscopy of individual HII
regions and to look for regions with special properties close to the the GRB
site. Using integral field spectroscopy with VIMOS we cover most of the high
surface brightness part of the host including the HII region where the
supernova and GRB occurred. The star formation rate, reddening, equivalent
width and stellar mass in the GRB region is similar to other HII regions in the
host. Extreme values arise in the only region that shows emission lines from
Wolf-Rayet stars; a region that lies 800 pc in projection from the GRB site.
Strong emission line diagnostics of all HII regions imply oxygen abundances
between 0.3 and 0.8 solar with the lowest values arising in the WR and GRB
regions. Comparing the measured emission line ratios for a sample of low
redshift GRB hosts to theoretical models and to observations of field galaxies,
we find that GRBs arise in a range of metallicity environments while the
regions are consistently very young. The similar line ratios of GRB hosts
compared to the WR region can arise in spatially unresolved galaxies with
bright HII regions near the GRB location. (Abridged)


title:
Near-Infrared Photometry of the Type IIn SN 2005ip: The Case for Dust
  Condensation

abstract:
  Near-infrared photometric observations of the Type IIn SN 2005ip in NGC 2906
reveal large fluxes (>1.3 mJy) in the K_s-band over more than 900 days. While
warm dust can explain the late-time K_s-band emission of SN 2005ip, the nature
of the dust heating source is ambiguous. Shock heating of pre-existing dust by
post-shocked gas is unlikely because the forward shock is moving too slowly to
have traversed the expected dust-free cavity by the time observations first
reveal the K_s emission. While an infrared light echo model correctly predicts
a near-infrared luminosity plateau, heating dust to the observed temperatures
of ~1400-1600 K at a relatively large distance from the supernova (> 10^{18}
cm) requires an extraordinarily high early supernova luminosity (~1 X 10^{11}
L_solar). The evidence instead favors condensing dust in the cool, dense shell
between the forward and reverse shocks. Both the initial dust temperature and
the evolutionary trend towards lower temperatures are consistent with this
scenario. We infer that radiation from the circumstellar interaction heats the
dust. While this paper includes no spectroscopic confirmation, the photometry
is comparable to other SNe that do show spectroscopic evidence for dust
formation. Observations of dust formation in SNe are sparse, so these results
provide a rare opportunity to consider SNe Type IIn as dust sources.


title: Astrophysical relevance of $\gamma$ transition energies

abstract:
  The relevant gamma energy range is explicitly identified where additional
gamma$ strength has to be located for having an impact on astrophysically
relevant reactions. It is shown that folding the energy dependences of the
transmission coefficients and the level density leads to maximal contributions
for gamma energies of 2<=E_gamma<=4 MeV unless quantum selection rules allow
isolated states to contribute. Under this condition, electric dipole
transitions dominate. These findings allow to more accurately judge the
relevance of modifications of the \gamma strength for astrophysics.


title:
Fingerprints for spin-selection rules in the interaction dynamics of O2
  at Al(111)

abstract:
  We performed mixed quantum-classical molecular dynamics simulations based on
first-principles potential-energy surfaces to demonstrate that the scattering
of a beam of singlet O2 molecules at Al(111) will enable an unambiguous
assessment of the role of spin-selection rules for the adsorption dynamics. At
thermal energies we predict a sticking probability that is substantially less
than unity, with the repelled molecules exhibiting characteristic kinetic,
vibrational and rotational signatures arising from the non-adiabatic spin
transition.


title: Effective completeness for real computation

abstract:
  The main result of this paper, as previously presented to arxiv, was
incorrect. See the full text for details and for reference to the remaining
results.


title:
Negative thermal expansion in single-component systems with isotropic
  interactions

abstract:
  We have devised an isotropic interaction potential that gives rise to
negative thermal expansion (NTE) behavior in equilibrium many-particle systems
in both two and three dimensions over a wide temperature and pressure range
(including zero pressure). An optimization procedure is used in order to find a
potential that yields a strong NTE effect. A key feature of the potential that
gives rise to this behavior is the softened interior of its basin of
attraction. Although such anomalous behavior is well known in material systems
with directional interactions (e.g., zirconium tungstate), to our knowledge
this is the first time that NTE behavior has been established to occur in
single-component many-particle systems for isotropic interactions. Using
constant-pressure Monte Carlo simulations, we show that as the temperature is
increased, the system exhibits negative, zero and then positive thermal
expansion before melting (for both two- and three-dimensional systems). The
behavior is explicitly compared to that of a Lennard-Jones system, which
exhibits typical expansion upon heating for all temperatures and pressures.


title: Corrugations in the Disk of the Edge-On Spiral Galaxy IC2233

abstract:
  We recently reported the discovery of a regular corrugation pattern in the HI
disk of the isolated, edge-on spiral galaxy IC2233. Here we present
measurements of the vertical structure of this galaxy at several additional
wavelengths, ranging from the far ultraviolet to the far infrared. We find that
undular patterns with amplitude ~5''(~250 pc) are visible in a variety of
Population I tracers in IC2233, including the young-to-intermediate age stars,
the HII regions, and the dust. However, the vertical excursions become less
pronounced in the older stellar populations traced by the mid-infrared light.
This suggests that the process leading to the vertical displacements may be
linked with the regulation of star formation in the galaxy. We have also
identified a relationship between the locations of the density corrugations and
small-amplitude (~5 km/s) velocity undulations in the HI rotation curve. We are
able to exclude several possible mechanisms for the origin of the observed
corrugations, including tidal interaction from a companion, Parker
instabilities, or a galactic bore. Global gravitational instabilities appear to
be the most likely explanation, although local perturbations may also be
important.


title: Spin-Foam Models and the Physical Scalar Product

abstract:
  This paper aims at clarifying the link between Loop Quantum Gravity and
Spin-Foam models in four dimensions. Starting from the canonical framework, we
construct an operator P acting on the space of cylindrical functions
Cyl($\Gamma$), where $\Gamma$ is the 4-simplex graph, such that its ma- trix
elements are, up to some normalization factors, the vertex amplitude of
Spin-Foam models. The Spin-Foam models we are considering are the topological
model, the Barrett-Crane model and the Engle-Pereira-Rovelli model. The
operator P is usually called the "projector" into physical states and its
matrix elements gives the physical scalar product. Therefore, we relate the
physical scalar product of Loop Quantum Gravity to vertex amplitudes of some
Spin-Foam models. We discuss the possibility to extend the action of P to any
cylindrical functions on the space manifold.


title: Negative Poisson's ratio materials via isotropic interactions

abstract:
  We show that under tension, a classical many-body system with only isotropic
pair interactions in a crystalline state can, counterintutively, have a
negative Poisson's ratio, or auxetic behavior. We derive the conditions under
which the triangular lattice in two dimensions and lattices with cubic symmetry
in three dimensions exhibit a negative Poisson's ratio. In the former case, the
simple Lennard-Jones potential can give rise to auxetic behavior. In the latter
case, negative Poisson's ratio can be exhibited even when the material is
constrained to be elastically isotropic.


title: Non-linear parent action and dual N=1 D=4 supergravity

abstract:
  We give N=1 supersymmetric extension of D=4 dual gravity non-linear action
proposed in arXiv:0806.2775. The dual supergravity action and symmetries of the
model, but supersymmetry, are realized in a local way.


title:
Anisotropic tunneling magnetoresistance and tunneling anisotropic
  magnetoresistance: spin-orbit coupling in magnetic tunnel junctions

abstract:
  The effects of the spin-orbit interaction on the tunneling magnetoresistance
of ferromagnet/semiconductor/normal metal tunnel junctions are investigated.
Analytical expressions for the tunneling anisotropic magnetoresistance (TAMR)
are derived within an approximation in which the dependence of the
magnetoresistance on the magnetization orientation in the ferromagnet
originates from the interference between Bychkov-Rashba and Dresselhaus
spin-orbit couplings that appear at junction interfaces and in the tunneling
region. We also investigate the transport properties of
ferromagnet/semiconductor/ferromagnet tunnel junctions and show that in such
structures the spin-orbit interaction leads not only to the TAMR effect but
also to the anisotropy of the conventional tunneling magnetoresistance (TMR).
The resulting anisotropic tunneling magnetoresistance (ATMR) depends on the
absolute magnetization directions in the ferromagnets. Within the proposed
model, depending on the magnetization directions in the ferromagnets, the
interplay of Bychkov-Rashba and Dresselhaus spin-orbit couplings produces
differences between the rates of transmitted and reflected spins at the
ferromagnet/seminconductor interfaces, which results in an anisotropic local
density of states at the Fermi surface and in the TAMR and ATMR effects. Model
calculations for Fe/GaAs/Fe tunnel junctions are presented. Furthermore, based
on rather general symmetry considerations, we deduce the form of the
magnetoresistance dependence on the absolute orientations of the magnetizations
in the ferromagnets.


title:
On the effect of temperature on the reentrant condensation in
  polyelectrolyte-liposome complexation

abstract:
  In systems of highly charged linear polyelectrolytes and oppositely charged
colloidal particles, long-lived clusters of polyelectrolyte-decorated particles
form in an interval of concentrations around the isoelectric point, where
reentrant condensation connected to charge inversion of cluster is observed.
The mechanisms that drive the aggregation and stabilize, at the different
polymer/particle ratios, a well defined size of the aggregates are not
completely understood. Moreover, a central question still remains unanswered,
i.e., whether the clusters are true equilibrium or metastable aggregates. To
elucidate this point, in this work, we have investigated the effect of the
temperature on the formation of the clusters. We employed liposomes built up by
DOTAP lipid interacting with a simple anionic polyion, sodium polyacrylate,
over an extended concentration range below and over the isoelectric condition.
Our results show that the aggregation process can be described by a
thermally-activated mechanism.


title:
Stabilizer Quantum Codes: A Unified View based on Forney-style Factor
  Graphs

abstract:
  Quantum error-correction codes (QECCs) are a vital ingredient of quantum
computation and communication systems. In that context it is highly desirable
to design QECCs that can be represented by graphical models which possess a
structure that enables efficient and close-to-optimal iterative decoding. In
this paper we focus on stabilizer QECCs, a class of QECCs whose construction is
rendered non-trivial by the fact that the stabilizer label code, a code that is
associated with a stabilizer QECC, has to satisfy a certain self-orthogonality
condition. In order to design graphical models of stabilizer label codes that
satisfy this condition, we extend a duality result for Forney-style factor
graphs (FFGs) to the stabilizer label code framework. This allows us to
formulate a simple FFG design rule for constructing stabilizer label codes, a
design rule that unifies several earlier stabilizer label code constructions.


title:
Semi-empirical white dwarf initial-final mass relationships: a thorough
  analysis of systematic uncertainties due to stellar evolution models

abstract:
  Using the most recent results about white dwarfs in 10 open clusters, we
revisit semi-empirical estimates of the initial-final mass relation in star
clusters, with emphasis on the use of stellar evolution models. We discuss the
influence of these models on each step of the derivation. One intention of our
work is to use consistent sets of calculations both for the isochrones and the
white dwarf cooling tracks. The second one is to derive the range of systematic
errors arising from stellar evolution theory. This is achieved by using
different sources for the stellar models and by varying physical assumptions
and input data. We find that systematic errors, including the determination of
the cluster age, are dominating the initial mass values, while observational
uncertainties influence the final mass primarily. After having determined the
systematic errors, the initial-final mass relation allows us finally to draw
conclusions about the physics of the stellar models, in particular about
convective overshooting.


title: Spin-Incoherent Transport in Quantum Wires

abstract:
  When a quantum wire is weakly confined, a conductance plateau appears at
e^2/h with decreasing carrier density in zero magnetic field accompanied by a
gradual suppression of the 2e^2/h plateau. Applying an in-plane magnetic field
B|| does not alter the value of this quantization; however, the e^2/h plateau
weakens with increasing B|| up to 9 T, and then strengthens on further
increasing B||, which also restores the 2e^2/h plateau. Our results are
consistent with spin-incoherent transport in a one-dimensional wire.


title:
Conservation Laws and the Multiplicity Evolution of Spectra at the
  Relativistic Heavy Ion Collider

abstract:
  Transverse momentum distributions in ultra-relativistic heavy ion collisions
carry considerable information about the dynamics of the hot system produced.
Direct comparison with the same spectra from $p+p$ collisions has proven
invaluable to identify novel features associated with the larger system, in
particular, the "jet quenching" at high momentum and apparently much stronger
collective flow dominating the spectral shape at low momentum. We point out
possible hazards of ignoring conservation laws in the comparison of high- and
low-multiplicity final states. We argue that the effects of energy and momentum
conservation actually dominate many of the observed systematics, and that $p+p$
collisions may be much more similar to heavy ion collisions than generally
thought.


title:
Extracting the Pair Distribution Function of Liquids and Liquid-Vapor
  Surfaces by Grazing Incidence X-ray Diffraction Mode

abstract:
  We show that the structure factor $S(q)$ of water can be obtained from X-ray
synchrotron experiments at grazing angle of incidence (in reflection mode) by
using a liquid surface diffractometer. The corrections used to obtain $S(q)$
self-consistently are described. Applying these corrections to scans at
different incident beam angles (above the critical angle) collapses the
measured intensities into a single master curve, without fitting parameters,
which within a scale factor yields $S(q)$. Performing the measurements below
the critical angle for total reflectivity yields the structure factor of the
top most layers of the water/vapor interface. Our results indicate water
restructuring at the vapor/water interface. We also introduce a new approach to
extract $g(r)$, the pair distribution function (PDF), by expressing the PDF as
a linear sum of Error functions whose parameters are refined by applying a
non-linear least square fit method. This approach enables a straightforward
determination of the inherent uncertainties in the PDF. Implications of our
results to previously measured and theoretical predictions of the PDF are also
discussed.


title: On the expected diameter of an L2-bounded martingale

abstract:
  It is shown that the ratio between the expected diameter of an L2-bounded
martingale and the standard deviation of its last term cannot exceed sqrt(3).
Moreover, a one-parameter family of stopping times on standard Brownian Motion
is exhibited, for which the sqrt(3) upper bound is attained. These stopping
times, one for each cost-rate c, are optimal when the payoff for stopping at
time t is the diameter D(t) obtained up to time t minus the hitherto
accumulated cost c t. A quantity related to diameter, maximal drawdown (or
rise), is introduced and its expectation is shown to be bounded by sqrt(2)
times the standard deviation of the last term of the martingale. These results
complement the Dubins and Schwarz respective bounds 1 and sqrt(2) for the
ratios between the expected maximum and maximal absolute value of the
martingale and the standard deviation of its last term. Dynamic programming
(gambling theory) methods are used for the proof of optimality.


title: Casimir Interactions for Anisotropic Magnetodielectric Metamaterials

abstract:
  We extend our previous work [Phys. Rev. Lett. {\bf 100}, 183602 (2008)] on
the generalization of the Casimir-Lifshitz theory to treat anisotropic
magnetodielectric media, focusing on the forces between metals and
magnetodielectric metamaterials and on the possibility of inferring magnetic
effects by measurements of these forces. We present results for metamaterials
including structures with uniaxial and biaxial magnetodielectric anisotropies,
as well as for structures with isolated metallic or dielectric properties that
we describe in terms of filling factors and a Maxwell Garnett approximation.
The elimination or reduction of Casimir "stiction" by appropriate engineering
of metallic-based metamaterials, or the indirect detection of magnetic
contributions, appear from the examples considered to be very challenging, as
small background Drude contributions to the permittivity act to enhance
attraction over repulsion, as does magnetic dissipation. In dielectric-based
metamaterials the magnetic properties of polaritonic crystals, for instance,
appear to be too weak for repulsion to overcome attraction. We also discuss
Casimir-Polder experiments, that might provide another possibility for the
detection of magnetic effects.


title:
Variational Particle Schemes for the Porous Medium Equation and for the
  System of Isentropic Euler Equations

abstract:
  Both the porous medium equation and the system of isentropic Euler equations
can be considered as steepest descents on suitable manifolds of probability
measures in the framework of optimal transport theory. By discretizing these
variational characterizations instead of the partial differential equations
themselves, we obtain new schemes with remarkable stability properties. We show
that they capture successfully the nonlinear features of the flows, such as
shocks and rarefaction waves for the isentropic Euler equations. We also show
how to design higher order methods for these problems in the optimal transport
setting using backward differentiation formula (BDF) multi-step methods or
diagonally implicit Runge-Kutta methods.


title:
Mode Switching for MIMO Communication Based on Delay and Channel
  Quantization

abstract:
  This paper has been withdrawn by the author as a major revision is made and a
new version is uploaded at arXiv:0812.3120


title:
A classical theory for second-harmonic generation from metallic
  nanoparticles

abstract:
  In this article, we develop a classical electrodynamic theory to study the
optical nonlinearities of metallic nanoparticles. The quasi-free electrons
inside the metal are approximated as a classical Coulomb-interacting electron
gas, and their motion under the excitation of an external electromagnetic field
is described by the plasma equations. This theory is further tailored to study
second-harmonic generation. Through detailed experiment-theory comparisons, we
validate this classical theory as well as the associated numerical algorithm.
It is demonstrated that our theory not only provides qualitative agreement with
experiments, it also reproduces the overall strength of the experimentally
observed second-harmonic signals.


title: Linear relations between polynomial orbits

abstract:
  We study the orbits of a polynomial f in C[X], namely the sets
{e,f(e),f(f(e)),...} with e in C. We prove that if nonlinear complex
polynomials f and g have orbits with infinite intersection, then f and g have a
common iterate. More generally, we describe the intersection of any line in C^d
with a d-tuple of orbits of nonlinear polynomials, and we formulate a question
which generalizes both this result and the Mordell--Lang conjecture.


title: Apparent and average acceleration of the Universe

abstract:
  In this paper we consider the relation between the volume deceleration
parameter obtained within the Buchert averaging scheme and the deceleration
parameter derived from the supernova observation. This work was motivated by
recent findings that showed that there are models which despite $\Lambda=0$
have volume deceleration parameter $q^{vol} < 0$. This opens the possibility
that backreaction and averaging effects may be used as an interesting
alternative explanation to the dark energy phenomenon.
  We have calculated $q^{vol}$ in some Lema\^itre--Tolman models. For those
models which are chosen to be realistic and which fit the supernova data, we
find that $q^{vol} > 0$, while those models which we have been able to find
which exhibit $q^{vol} < 0$ turn out to be unrealistic. This indicates that
care must be exercised in relating the deceleration parameter to observations.


title: On Ritt's polynomial decomposition theorems

abstract:
  Ritt studied the functional decomposition of a univariate complex polynomial
f into prime (indecomposable) polynomials, f = u_1 o u_2 o ... o u_r. His main
achievement was a procedure for obtaining any decomposition of f from any other
by repeatedly applying certain transformations. However, Ritt's results provide
no control on the number of times one must apply the basic transformations,
which makes his procedure unsuitable for many theoretical and algorithmic
applications. We solve this problem by giving a new description of the
collection of all decompositions of a polynomial. Our results have been used by
Ghioca, Tucker and Zieve (arXiv:0807.3576) to describe the polynomials f,g
having orbits with infinite intersection; they have also been used by Medvedev
and Scanlon to describe the affine curves invariant under a coordinatewise
polynomial action.


title:
Thermodynamic consistency and fast dynamics in phase field crystal
  modeling

abstract:
  A general formulation is presented to derive the equation of motion and to
demonstrate thermodynamic consistency for several classes of phase field models
at once. It applies to models with a conserved phase field, describing either
uniform or periodic stable states, and containing slow as well as fast
thermodynamic variables. The approach is based on an entropy functional
formalism previously developed in the context of phase field models for uniform
states [P. Galenko and D. Jou, Phys. Rev. E {\bf 71}, 046125 (2005)] and thus
allows to extend several properties of the latter to phase field models for
periodic states (phase field crystal models). In particular, it allows to
demonstrate the concept of thermodynamic consistency for phase field crystal
models with fast dynamics.


title: Zero patterns and unitary similarity

abstract:
  A subspace of the space, L(n), of traceless complex $n\times n$ matrices can
be specified by requiring that the entries at some positions $(i,j)$ be zero.
The set, $I$, of these positions is a (zero) pattern and the corresponding
subspace of L(n) is denoted by $L_I(n)$. A pattern $I$ is universal if every
matrix in L(n) is unitarily similar to some matrix in $L_I(n)$. The problem of
describing the universal patterns is raised, solved in full for $n\le3$, and
partial results obtained for $n=4$. Two infinite families of universal patterns
are constructed. They give two analogues of Schur's triangularization theorem.


title: Chaos assisted decay of $^{180}Ta^m$

abstract:
  The decay of the $J=9^-$ isomeric state in $^{180}Ta$ is described in a model
based on the phenomenon of chaos assisted tunneling. The model attempts to
explain the enhanced decay of the isomeric state when irradiated by gamma-rays
or subjected to Coulomb excitations.


title: Error Correction Capability of Column-Weight-Three LDPC Codes: Part II

abstract:
  The relation between the girth and the error correction capability of
column-weight-three LDPC codes is investigated. Specifically, it is shown that
the Gallager A algorithm can correct $g/2-1$ errors in $g/2$ iterations on a
Tanner graph of girth $g \geq 10$.


title: On a Conjecture of Harvey and Lawson

abstract:
  We consider complex projective space P^{n} and a smooth closed curve gamma in
P^{n}. Harvey and Lawson have defined the notion of the projective hull \hat{K}
of a compact subset K in P^n. This concept is an analogue of the polynomial
hull of compact subsets of C^{n}. In the present note we study the relation
between the following two properties of the curve gamma:
  (1) \hat{gamma} - gamma is a one-dimensional complex analytic subvariety of
  P^{n} - gamma, and
  (2) There exists a Stein subdomain of P^{n} which contains the projective
hull \hat{gamma} of gamma.


title:
Anomalous flux quantization and formation of dipole-flux state in a
  multiply-connected high-Tc NdBa2Cu3O7-d superconductor

abstract:
  High-resolution scanning superconducting quantum interference device (SQUID)
microscopy was used to study the flux quantization phenomenon in
multiply-connected anisotropic high-Tc NdBa2Cu3O7-d single crystalline thin
films. The spatial distribution of internal flux in a hole was found to be
non-uniform and changed drastically for applied small fields. With increased
fields above 10uT, a local magnetic dipole flux developed inside the hole, in
contrast to an isotropic Nb superconductor. The total net flux trapped in a
hole was kept to be constant for larger holes, but the abrupt transition of
flux quantization state was observed for smaller holes. The possible
explanation is given based on the anisotropic dx2-y2-wave order parameter of
high-Tc superconductors.


title: Dynamical Backaction of Microwave Fields on a Nanomechanical Oscillator

abstract:
  We measure the response and thermal motion of a high-Q nanomechanical
oscillator coupled to a superconducting microwave cavity in the
resolved-sideband regime where the oscillator's resonance frequency exceeds the
cavity's linewidth. The coupling between the microwave field and mechanical
motion is strong enough for radiation pressure to overwhelm the intrinsic
mechanical damping. This radiation-pressure damping cools the fundamental
mechanical mode by a factor of 5 below the thermal equilibrium temperature in a
dilution refrigerator to a phonon occupancy of 140 quanta.


title:
Neutron diffraction in a model itinerant metal near a quantum critical
  point

abstract:
  Neutron diffraction measurements on single crystals of Cr1-xVx (x=0, 0.02,
0.037) show that the ordering moment and the Neel temperature are continuously
suppressed as x approaches 0.037, a proposed Quantum Critical Point (QCP). The
wave vector Q of the spin density wave (SDW) becomes more incommensurate as x
increases in accordance with the two band model. At xc=0.037 we have found
temperature dependent, resolution limited elastic scattering at 4
incommensurate wave vectors Q=(1+/-delta_1,2, 0, 0)*2pi/a, which correspond to
2 SDWs with Neel temperatures of 19 K and 300 K. Our neutron diffraction
measurements indicate that the electronic structure of Cr is robust, and that
tuning Cr to its QCP results not in the suppression of antiferromagnetism, but
instead enables new spin ordering due to novel nesting of the Fermi surface of
Cr.


title:
Chandra Observation of the Edge-on Spiral NGC 5775: Probing the Hot
  Galactic Disk/Halo Connection

abstract:
  We study the edge-on galaxy NGC 5775, utilizing a 58.2 ks {\sl Chandra}
ACIS-S observation together with complementary {\sl HST} ACS, {\sl Spitzer}
IRAC and other multi-wavelength data sets. This edge-on galaxy, with its
disk-wide active star formation, is particularly well-suited for studying the
disk/halo interaction on sub-galactic scales. We detect 27 discrete X-ray
sources within the $D_{25}$ region of the galaxy, including an ultra-luminous
source with a 0.3-7 keV luminosity of $\sim7\times10^{40}\rm ergs s^{-1}$. The
source-removed diffuse X-ray emission shows several prominent extraplanar
features, including a $\sim10\rm kpc$ diameter ``shell-like'' feature and a
``blob'' reaching a projected distance of $\sim25\rm kpc$ from the galactic
disk. The bulk of the X-ray emission in the halo has a scale height of
$\sim$1.5 kpc and can be characterized by a two-temperature optically thin
thermal plasma with temperatures of $\sim$ 0.2 and 0.6 keV and a total 0.3-2
keV luminosity of $\sim3.5\times10^{39}\rm ergs s^{-1}$. The high-resolution,
multi-wavelength data reveal the presence of several extraplanar features
around the disk, which appear to be associated with the in-disk star formation.
We suggest that hot gas produced with different levels of mass loading can have
different temperatures, which may explain the characteristic temperatures of
hot gas in the halo. We have obtained a sub-galactic scale X-ray-intensity-star
formation relation, which is consistent with the integrated version in other
star forming galaxies.


title:
Spectrum and atmosphere models of irradiated transiting extrasolar giant
  planets

abstract:
  We show that a consistent fit to observed secondary eclipse data for several
strongly irradiated transiting planets demands a temperature inversion
(stratosphere) at altitude. Such a thermal inversion significantly influences
the planet/star contrast ratios at the secondary eclipse,their wavelength
dependences, and, importantly, the day-night flux contrast during a planetary
orbit. The presence of the thermal inversion/stratosphere seems to roughly
correlate with the stellar flux at the planet. Such temperature inversions
might caused by an upper-atmosphere absorber whose exact nature is still
uncertain


title:
Influence of Pure Dephasing on Emission Spectra from Single Photon
  Sources

abstract:
  We investigate the light-matter interaction of a quantum dot with the
electromagnetic field in a lossy microcavity and calculate emission spectra for
non-zero detuning and dephasing. It is found that dephasing shifts the
intensity of the emission peaks for non-zero detuning. We investigate the
characteristics of this intensity shifting effect and offer it as an
explanation for the non-vanishing emission peaks at the cavity frequency found
in recent experimental work.


title:
Counting the Faces of Randomly-Projected Hypercubes and Orthants, with
  Applications

abstract:
  Let $A$ be an $n$ by $N$ real valued random matrix, and $\h$ denote the
$N$-dimensional hypercube. For numerous random matrix ensembles, the expected
number of $k$-dimensional faces of the random $n$-dimensional zonotope $A\h$
obeys the formula $E f_k(A\h) /f_k(\h) = 1-P_{N-n,N-k}$, where $P_{N-n,N-k}$ is
a fair-coin-tossing probability. The formula applies, for example, where the
columns of $A$ are drawn i.i.d. from an absolutely continuous symmetric
distribution. The formula exploits Wendel's Theorem\cite{We62}.
  Let $\po$ denote the positive orthant; the expected number of $k$-faces of
the random cone$A \po$ obeys $ {\cal E} f_k(A\po) /f_k(\po) = 1 - P_{N-n,N-k}$.
The formula applies to numerous matrix ensembles, including those with iid
random columns from an absolutely continuous, centrally symmetric distribution.
There is an asymptotically sharp threshold in the behavior of face counts of
the projected hypercube; thresholds known for projecting the simplex and the
cross-polytope, occur at very different locations. We briefly consider face
counts of the projected orthant when $A$ does not have mean zero; these do
behave similarly to those for the projected simplex. We consider non-random
projectors of the orthant; the 'best possible' $A$ is the one associated with
the first $n$ rows of the Fourier matrix.
  These geometric face-counting results have implications for signal
processing, information theory, inverse problems, and optimization. Most of
these flow in some way from the fact that face counting is related to
conditions for uniqueness of solutions of underdetermined systems of linear
equations.


title: Thermal effects on the Fission Barrier of neutron-rich nuclei

abstract:
  We discuss the fission barrier height of neutron-rich nuclei in a r-process
site at highly excited state, which is resulted from the beta-decay or the
neutron-capture processes. We particularly investigate the sensitivity of the
fission barrier height to the temperature, including the effect of pairing
phase transition from superfluid to normal fluid phases. To this end, we use
the finite-temperature Skyrme-Hartree-Fock-Bogolubov method with a zero-range
pairing interaction. We also discuss the temperature dependence of the fission
decay rate.


title: 1-D Dirac Equation, Klein Paradox and Graphene

abstract:
  Solutions of the one dimensional Dirac equation with piece-wise constant
potentials are presented using standard methods. These solutions show that the
Klein Paradox is non-existent and represents a failure to correctly match
solutions across a step potential. Consequences of this exact solution are
studied for the step potential and a square barrier. Characteristics of
massless Dirac states and the momentum linear band energies for Graphene are
shown to have quite different current and momentum properties.


title: An outer bound for 2-receiver discrete memoryless broadcast channels

abstract:
  An outer bound to the two-receiver discrete memoryless broadcast channel is
presented. We compare it to the known outer bounds and show that the outer
bound presented is at least as tight as the existing bounds.


title:
How to securely decouple quantum systems: local shredding of bipartite
  correlations

abstract:
  This paper has been withdrawn by the author, as it is now incorporated in
0901.4506 (v4)


title: Kondo effect in carbon nanotube quantum dots with spin-orbit coupling

abstract:
  Motivated by recent experimental observation of spin-orbit coupling in carbon
nanotube quantum dots [F. Kuemmeth \textsl{et al.}, Nature (London) {\bf 452},
448 (2008)], we investigate in detail its influence on the Kondo effect. The
spin-orbit coupling intrinsically lifts out the fourfold degeneracy of a single
electron in the dot, thereby breaking the SU(4) symmetry and splitting the
Kondo resonance even at zero magnetic field. When the field is applied, the
Kondo resonance further splits and exhibits fine multipeak structures resulting
from the interplay of spin-orbit coupling and Zeeman effect. A microscopic
cotunneling process for each peak can be uniquely identified. Finally, a purely
orbital Kondo effect in the two-electron regime is also obtained.


title: Theoretical review on sin2beta(phi_1) from b to s penguins

abstract:
  Recent theoretical results of the standard model expectations on
$\sin2\beta_{\rm eff}$ from penguin-dominated $b \to s$ decays are briefly
reviewed.


title: New M dwarf debris disk candidates in NGC 2547

abstract:
  With only six known examples, M-dwarf debris disks are rare, even though M
dwarfs constitute the majority of stars in the Galaxy. After finding a new M
dwarf debris disk in a shallow mid-infrared observation of NGC 2547, we present
a considerably deeper Spitzer-MIPS image of the region, with a maximum exposure
time of 15 minutes per pixel. Among sources selected from a previously
published membership list, we identify nine new M dwarfs with excess emission
at 24 micron tracing warm material close to the snow line of these stars, at
orbital radii of less than 1 AU. We argue that these are likely debris disks,
suggesting that planet formation is under way in these systems. Interestingly,
the estimated excess fraction of M stars appears to be higher than that of G
and K stars in our sample.


title: Recoil Effect of Photoelectrons in the Fermi-Edge of Simple Metals

abstract:
  High energy resolution photoelectron spectroscopy of conduction electrons in
the vicinity of the Fermi-edge in Al and Au at the excitation energy of 880 and
7940 eV was carried out using synchrotron radiation. For the excitation energy
of 7940 eV, the observed Fermi energy of Al shows a remarkable shift to higher
binding energy as compared with that of Au, with accompanying broadening. This
is due to the recoil effect of the emitted photoelectrons. The observed spectra
are well reproduced by a simple model of Bloch electrons based on the isotropic
Debye model.


title: Quantum Matching Pennies Game

abstract:
  A quantum version of the Matching Pennies (MP) game is proposed that is
played using an Einstein-Podolsky-Rosen-Bohm (EPR-Bohm) setting. We construct
the quantum game without using the state vectors, while considering only the
quantum mechanical joint probabilities relevant to the EPR-Bohm setting. We
embed the classical game within the quantum game such that the classical MP
game results when the quantum mechanical joint probabilities become
factorizable. We report new Nash equilibria in the quantum MP game that emerge
when the quantum mechanical joint probabilities maximally violate the
Clauser-Horne-Shimony-Holt form of Bell's inequality.


title: A new upper bound for 3-SAT

abstract:
  We show that a randomly chosen 3-CNF formula over n variables with
clauses-to-variables ratio at least 4.4898 is, as n grows large, asymptotically
almost surely unsatisfiable. The previous best such bound, due to Dubois in
1999, was 4.506. The first such bound, independently discovered by many groups
of researchers since 1983, was 5.19. Several decreasing values between 5.19 and
4.506 were published in the years between. The probabilistic techniques we use
for the proof are, we believe, of independent interest.


title:
A note on artificial deformation in object shapes due to the
  pixelization

abstract:
  We qualitatively examine properties of artificial deformation in shapes of
objects (galaxies and stars) induced by the pixelization effects (also called
as the aliasing effects) using toy mock simulation images. We pay a special
attention to the the second pixelization because it might be a potential source
of a systematic noise in a weak lensing analysis. In particular, it is found
that resampling with rotation induces artificial ellipticities in object shapes
having a periodic concentric-circle-shaped pattern. Our major findings are as
follows. (1) Root-mean-square (RMS) of artificial ellipticities in object
shapes induced by the first pixelization effect can be as large as RMS > 10^-2
if a characteristic size of objects (e.g., the FWHM) is smaller than twice of
the pixel size. While for larger objects, it quickly becomes very small (RMS <
10^-5). (2) The amplitude of the shape deformation induced by the second
pixelization effect depends on the object size. It also depends strongly on an
interpolation scheme adopted to carry out resampling and on the grid size of
the output pixels. The RMS of ellipticities in object shapes induced by the
second pixelization effect can be suppressed to well below 10^{-2} if one
adopts a proper interpolation scheme (implemented in popular image processing
softwares). We also discuss an impact of the pixelization effects on a weak
lensing analysis.


title: Alcove walks, buildings, symmetric functions and representations

abstract:
  For a complex simple Lie algebra, the dimension $K_{\lambda\mu}$ of the $\mu$
weight space of a finite dimensional representation of highest weight $\lambda$
is the same as the number of Littelmann paths of type $\lambda$ and weight
$\mu$. In this paper we give an explicit construction of a path of type
$\lambda$ and weight $\mu$ whenever $K_{\lambda\mu}\ne 0$. This construction
has additional consequences, it produces an explicit point in the building
which chamber retracts to $\lambda$ and sector retracts to $\mu$, and an
explicit point of the affine Grassmannian in the corresponding
Mirkovi\'c-Vilonen intersection. In an appendix we discuss the connection
between retractions in buildings and alcove walks.


title: Rank-Crank type PDE's and non-holomorphic Jacobi forms

abstract:
  In this paper we show how Rank-Crank type PDE's (first found by Atkin and
Garvan) occur naturally in the framework of non-holomorphic Jacobiforms and
find an infinite family of such differential equations. As an application we
show an infinite family of congruences for odd Durfee symbols, a partition
statistic introduced by George Andrews.


title: Supmech: the Geometro-statistical Formalism Underlying Quantum Mechanics

abstract:
  As the first step in an approach to the solution of Hilbert's sixth problem,
a general scheme of mechanics, called `supmech', is developed integrating
noncommutative symplectic geometry and noncommutative probability theory in an
algebraic framework; it has quantum mechanics (QM) and classical mechanics as
special subdisciplines and facilitates an autonomous development of QM and
satisfactory treatments of quantum-classical correspondence and quantum
measurements (including a straightforward \emph{derivation} of the von Neumann
reduction rule). The scheme associates, with every `experimentally accessible'
system, a symplectic superalgebra and operates essentially as noncommutative
Hamiltonian mechanics incorporating the extra condition that the sets of
observables and pure states be mutually separating. The latter condition serves
to smoothly connect the algebraically defined quantum systems to ilbert
space-based ones; the rigged Hilbert space - based Dirac bra-ket formalism
naturally appears. The formalism has a natural place for commutative
superselection rules. Noncommutative analogues of objects like the momentum map
and the Poincar$\acute{e}$-Cartan form are introduced and some related
symplectic geometry developed.


title:
Phase structure of the quartic-cubic generalized two dimensional Yang
  Mills U(N) on the sphere

abstract:
  The large-N behavior of the quartic-cubic generalized two dimensional Yang
Mills U(N) on the sphere is investigated, for small cubic couplings. It is
shown that single transition at the critical area which is present for the
quartic model, is split into two transitions, both of them are third order. the
phase diagram of the system for small cubic couplings is obtained.


title: Defect production due to quenching through a multicritical point

abstract:
  We study the generation of defects when a quantum spin system is quenched
through a multicritical point by changing a parameter of the Hamiltonian as
$t/\tau$, where $\tau$ is the characteristic time scale of quenching. We argue
that when a quantum system is quenched across a multicritical point, the
density of defects ($n$) in the final state is not necessarily given by the
Kibble-Zurek scaling form $n \sim 1/\tau^{d \nu/(z \nu +1)}$, where $d$ is the
spatial dimension, and $\nu$ and $z$ are respectively the correlation length
and dynamical exponent associated with the quantum critical point. We propose a
generalized scaling form of the defect density given by $n \sim
1/\tau^{d/(2z_2)}$, where the exponent $z_2$ determines the behavior of the
off-diagonal term of the $2 \times 2$ Landau-Zener matrix at the multicritical
point. This scaling is valid not only at a multicritical point but also at an
ordinary critical point.


title: Thermal inflation, baryogenesis and axions

abstract:
  In a previous paper, we proposed a simple extension of the Minimal
Supersymmetric Standard Model which gives rise to thermal inflation and
baryogenesis in a natural and remarkably consistent way. In this paper, we
consider the $\lambda_\phi = 0$ special case of our model, which is the minimal
way to incorporate a Peccei-Quinn symmetry. The axino/flatino becomes the
lightest supersymmetric particle with $m_\axino \sim 1$ to $10 \GeV$ and is
typically over-produced during the flaton decay. Interestingly though, the dark
matter abundance is minimized for $m_\axino \sim 1 \GeV$, $f_a \sim 10^{11}$ to
$10^{12} \GeV$ and $|\mu| \sim 400 \GeV$ to $2 \TeV$ at an abundance coincident
with the observed abundance and with significant amounts of both axions and
axinos. Futhermore, for these values the baryon abundance naturally matches the
observed abundance.


title:
Differential postural effects of plantar-flexor muscles fatigue under
  normal, altered and improved vestibular and neck somatosensory conditions

abstract:
  The aim of the present study was to assess the effects of plantar-flexor
muscles fatigue on postural control during quiet standing under normal, altered
and improved vestibular and neck somatosensory conditions. To address this
objective, young male university students were asked to stand upright as still
as possible with their eyes closed in two conditions of No Fatigue and Fatigue
of the plantar-flexor muscles. In Experiment 1 (n=15), the postural task was
executed in two Neutral head and Head tilted backward postures, recognized to
degrade vestibular and neck somatosensory information. In Experiment 2 (n=15),
the postural task was executed in two conditions of No tactile and Tactile
stimulation of the neck provided by the application of strips of adhesive
bandage to the skin over and around the neck. Centre of foot pressure
displacements were recorded using a force platform. Results showed that (1) the
Fatigue condition yielded increased CoP displacements relative to the No
Fatigue condition (Experiment 1 and Experiment 2), (2) this destabilizing
effect was more accentuated in the Head tilted backward posture than Neutral
head posture (Experiment 1) and (3) this destabilizing effect was less
accentuated in the condition of Tactile stimulation than that of No tactile
stimulation of the neck (Experiment 2). In the context of the multisensory
control of balance, these results suggest an increased reliance on vestibular
and neck somatosensory information for controlling posture during quiet
standing in condition of altered ankle neuromuscular function.


title:
Vortices in rotating optical lattices: commensurability, hysteresis, and
  proximity to the Mott State

abstract:
  Quantized vortices stunningly illustrate the coherent nature of a superfluid
Bose condensate of alkali atoms. Introducing an optical lattice depletes this
coherence. Consequently, novel vortex physics may emerge in an experiment on a
harmonically trapped gas in the presence of a rotating optical lattice. The
most dramatic effects would occur in proximity to the Mott state, an
interaction dominated insulator with a fixed integer number of particles per
site. We model such a rotating gas, showing that the lattice-induced spatial
profile of the superfluid density drives a gross rearrangement of vortices. For
example, instead of the uniform vortex lattices commonly seen in experiments,
we find parameters for which the vortices all sit at a fixed distance from the
center of the trap, forming a ring. Similarly, they can coalesce at the center,
forming a giant vortex. We find that the properties of this system are
hysteretic, even far from the Mott state. We explain this hysteresis in terms
of vortex pinning, commensurability between vortex density and pinning site
density, and energy barriers against changing the number of vortices. Finally,
we model time-of-flight expansion, demonstrating the experimental observability
of our predictions.


title: Few qubit atom-light interfaces with collective encoding

abstract:
  Samples with few hundred atoms within a few micrometer sized region of space
are large enough to provide efficient cooperative absorption and emission of
light, and small enough to ensure strong dipole-dipole interactions when atoms
are excited into high-lying Rydberg states. Based on a recently proposed
collective encoding scheme, we propose to build few-qubit quantum registers in
such samples. The registers can store and transmit quantum information in the
form of single photons, and they can employ entanglement pumping protocols to
perform ideally in networks for scalable quantum computing and long distance
quantum communication.


title: Logarithmic Stable Maps

abstract:
  We introduce the notion of a logarithmic stable map from a minimal log
prestable curve to a log twisted semi-stable variety of form $xy=0$. We study
the compactification of the moduli spaces of such maps and provide a perfect
obstruction theory, applicable to the moduli spaces of (un)ramified stable maps
and stable relative maps. As an application, we obtain a modular
desingularization of the main component of Kontsevich's moduli space of
elliptic stable maps to a projective space.


title:
Existence of traveling waves for a nonlocal monostable equation: an
  abstract approach

abstract:
  We consider a nonlocal analogue of the Fisher-KPP equation. We do not assume
that the Borel-measure for the convolution is absolutely continuous. In order
to show the main result, we modify a recursive method for abstract monotone
discrete dynamical systems by Weinberger. We note that the monotone semiflow
generated by the equation does not have compactness with respect to the
compact-open topology. At the end, we propose a discrete model that describes
the measurement process.


title: Three dimensional Casimir piston for massive scalar fields

abstract:
  We consider Casimir force acting on a three dimensional rectangular piston
due to a massive scalar field subject to periodic, Dirichlet and Neumann
boundary conditions. Exponential cut-off method is used to derive the Casimir
energy in the interior region and the exterior region separated by the piston.
It is shown that the divergent term of the Casimir force acting on the piston
due to the interior region cancels with that due to the exterior region, thus
render a finite well-defined Casimir force acting on the piston. Explicit
expressions for the total Casimir force acting on the piston is derived, which
show that the Casimir force is always attractive for all the different boundary
conditions considered. As a function of a -- the distance from the piston to
the opposite wall, it is found that the magnitude of the Casimir force behaves
like $1/a^4$ when $a\to 0^+$ and decays exponentially when $a\to \infty$.
Moreover, the magnitude of the Casimir force is always a decreasing function of
a. On the other hand, passing from massless to massive, we find that the effect
of the mass is insignificant when a is small, but the magnitude of the force is
decreased for large a in the massive case.


title:
Reconstruction of HI power spectra with radio-interferometers to study
  dark energy

abstract:
  Among the tools available for the study of the dark energy driving the
expansion of the Universe, Baryon Acoustic Oscillations (BAO) and their effects
on the matter power spectrum are particularly attractive. It was recently
proposed to study these oscillations by mapping the 21cm emission of the
neutral hydrogen in the redshift range $0.5<z<3$. We discuss here the precision
of such measurements using radio-interferometers consisting of arrays of dishes
or north-south oriented cylinders. We then discuss the resulting uncertainties
on the BAO scales and the sensitivity to the parameters of the Dark Energy
equation of state.


title:
Variational Monte Carlo Study of a Spinless Fermion t-V Model on a
  Triangular Lattice: Formation of a Pinball Liquid

abstract:
  We analyze a model of spinless fermions on a triangular lattice at
half-filling interacting via strong nearest-neighbor repulsive interactions, V,
using the variational Monte Carlo simulation technique. The existence of
three-sublattice long-range order is confirmed by the finite-size scaling
analysis of the charge structural factor at V_c/t > 12. This ordered phase
shows characteristics expected for a so called "pinball liquid" state, which
has the spontaneous separation of fermionic degrees of freedom into coexisting
Wigner crystal-like charge order (pin) and a metal (ball). The pins are fixed
in order to maximize the kinetic energy gain of balls which move almost freely.
The Fermi surface is reconstructed at V=V_c and remains towards the strong
coupling limit. These features reminiscent of the strong correlation together
with the large value of V_c/t distinguishes the pinball liquid from the
conventional charge-density-wave.


title: Protecting Quantum Information with Entanglement and Noisy Optical Modes

abstract:
  We incorporate active and passive quantum error-correcting techniques to
protect a set of optical information modes of a continuous-variable quantum
information system. Our method uses ancilla modes, entangled modes, and gauge
modes (modes in a mixed state) to help correct errors on a set of information
modes. A linear-optical encoding circuit consisting of offline squeezers,
passive optical devices, feedforward control, conditional modulation, and
homodyne measurements performs the encoding. The result is that we extend the
entanglement-assisted operator stabilizer formalism for discrete variables to
continuous-variable quantum information processing.


title: Winding Number of Fractional Brownian Motion

abstract:
  We find the exact winding number distribution of Riemann-Liouville fractional
Brownian motion for large times in two dimensions using the propagator of a
free particle. The distribution is similar to the Brownian motion case and it
is of Cauchy type. In addition we find the winding number distribution of
fractal time process, i.e., time fractional Fokker-Planck equation, in the
presence of finite size winding center.