title: Persistent Spin Dynamics in the $S=1/2$ V$_{15}$ Molecular Nano-Magnet

abstract:
  We present muon spin lattice relaxation measurements in the V15 spin 1/2
molecular nano-magnet. We find that the relaxation rate in low magnetic fields
(<5 kG) is temperature independent below ~10 K, implying that the molecular
spin is dynamically fluctuating down to 12 mK. These measurements show that the
fluctuation time increases as the temperature is decreased and saturates at a
value of ~6 nsec at low temperatures. The fluctuations are attributed to V15
molecular spin dynamics perpendicular to the applied magnetic field direction,
induced by coupling between the molecular spin and nuclear spin bath in the
system.


title: Trapped-ion quantum logic gates based on oscillating magnetic fields

abstract:
  Oscillating magnetic fields and field gradients can be used to implement
single-qubit rotations and entangling multi-qubit quantum gates for trapped-ion
quantum information processing (QIP). With fields generated by currents in
microfabricated surface-electrode traps, it should be possible to achieve gate
speeds that are comparable to those of optically induced gates for realistic
distances between the ion crystal and the electrode surface.
Magnetic-field-mediated gates have the potential to significantly reduce the
overhead in laser beam control and motional state initialization compared to
current QIP experiments with trapped ions and will eliminate spontaneous
scattering, a fundamental source of decoherence in laser-mediated gates.


title:
Metric characterizations of isometries and of unital operator spaces and
  systems

abstract:
  We give some new characterizations of unitaries, isometries, unital operator
spaces, unital function spaces, operator systems, C*-algebras, and related
objects. These characterizations only employ the vector space and operator
space structure.


title: Theory of the Magnetic Moment in Iron Pnictides

abstract:
  We show that the combined effects of spin-orbit, monoclinic distortion, and
p-d hybridization in tetrahedrally coordinated Fe in LaOFeAs invalidates the
naive Hund's rule filling of the Fe d-levels. The two highest occupied levels
have one electron each but as a result of the p-d hybridization have very
different on-site repulsions. As a result, electrons in the upper level are
more itinerant while those in the lower level are more localized. It is the
xy-projection of the spin in the lower level that orders antiferromagnetically
as the z-components of the spins in the two levels is shown to be vanishingly
small in the ground state. The resulting magnetic moment is highly anisotropic
with an in-plane value of $0.25-0.35\mu_B$ per Fe and a z-projection of
$0.06\mu_B$, both of which are in agreement with experiment. As a consequence,
we arrive the minimal model that describes the electronic properties of
LaOFeAs.


title: Effect of Density Inhomogeneity on YORP: The case of Itokawa

abstract:
  The effect of density inhomogeneity on the YORP effect for a given shape
model is investigated. A density inhomogeneity will cause an offset between the
center of figure and the center of mass and a re-orientation of the principal
axes away from those associated with the shape alone. Both of these effects can
alter the predicted YORP rate of change in angular velocity and obliquity. We
apply these corrections to the Itokawa shape model and find that its YORP
angular velocity rate is sensitive to offsets between its center of mass and
center of figure, with a shift on the order of 10 meters being able to change
the sign of the YORP effect for that asteroid. Given the non-detection of YORP
for Itokawa as of 2008, this can shed light on the density distribution within
that body. The theory supports a shift of the asteroid center of mass towards
Itokawa's neck region, where there is an accumulation of finer gravels.
Detection of the YORP effect for Itokawa should provide some strong constraints
on its density distribution. This theory could also be applied to asteroids
visited by future spacecraft to constrain density inhomogeneities.


title:
Multiwavelength study of Cygnus A I. Precession and slow jet speeds from
  radio observations

abstract:
  We study the jet and counterjet of the powerful classical double FRII radio
galaxy Cygnus A as seen in the 5, 8 and 15-GHz radio bands using the highest
spatial resolution and signal-to-noise archival data available. We demonstrate
that the trace of the radio knots that delineate the jet and counterjet
deviates from a straight line and that the inner parts can be satisfactorily
fitted with the precession model of Hjellming & Johnston. The parameter values
of the precession model fits are all plausible although the jet speed is rather
low (< 0.5 c) but, on investigation, found to be consistent with a number of
other independent estimates of the jet speed in Cygnus A. We compare the masses
and precession periods for sources with known precession and find that for the
small number of AGN with precessing jets the precession periods are
significantly longer than those for microquasars.


title: Independence of P vs. NP in regards to oracle relativizations

abstract:
  This is the third article in a series of four articles dealing with the P vs.
NP question. The purpose of this work is to demonstrate that the methods used
in the first two articles of this series are not affected by oracle
relativizations. Furthermore, the solution to the P vs. NP problem is actually
independent of oracle relativizations.


title:
Application of Contractor Renormalization Group (CORE) to the Heisenberg
  zig-zag and the Hubbard chain

abstract:
  The COntractor REnormalization group method was devised in 1994 by
Morningstar and Weinstein. It was primarily aimed at extracting the physics of
lattice quantum field theories (like lattice Quantum Chromodynamics). However,
it is a general method of analyzing Hamiltonian lattice systems, e.g. Ising,
Heisenberg or Hubbard models. The aim of this work is to show the application
of CORE to one-dimensional quantum systems -- the Heisenberg zig-zag model and
the Hubbard chain. As a test of the method, the ground state energy of these
systems will be calculated.


title:
Multiwavelength study of Cygnus A II. X-ray inverse-Compton emission
  from a relic counterjet and implications for jet duty-cycles

abstract:
  The duty-cycle of powerful radio galaxies and quasars such as the prototype
Cygnus A is poorly understood. X-ray observations of inverse-Compton scattered
Cosmic Microwave Background (ICCMB) photons probe lower Lorentz-factor
particles than radio observations of synchrotron emission. Comparative studies
of the nearer and further lobes, separated by many 10s of kpc and thus 10s of
thousands of years in light-travel time, yield additional temporal resolution
in studies of the lifecycles. We have co-added all archival Chandra ACIS-I data
and present a deep 200 ks image of Cygnus A. This deep image reveals the
presence of X-ray emission from a counterjet i.e. a jet receding from Earth and
related to a previous episode of jet activity. The non-thermal X-ray emission,
we interpret as ICCMB radiation. There is an absence of any discernible X-ray
emission associated with a jet flowing towards Earth. We conclude that: (1) The
emission from a relic jet, indicates a previous episode of jet activity, that
took place earlier than the current jet activity appearing as synchrotron radio
emission. (2) The presence of X-ray emission from a relic counterjet of Cygnus
A and the absence of X-ray emission associated with any relic approaching jet
constrains the timescale between successive episodes of jet activity to ~10^6
years. (3) Transverse expansion of the jet causes expansion losses which shifts
the energy distribution to lower energies. (4) Assuming the electrons cooled
due to adiabatic expansion, the required magnetic field strength is
substantially smaller than the equipartition magnetic field strength. (5) A
high minimum Lorentz factor for the distribution of relativistic particles in
the current jet, of a few 10^3, is ejected from the central nucleus of this
active galaxy. Abridged.


title:
Predicting the cosmological constant with the scale-factor cutoff
  measure

abstract:
  It is well known that anthropic selection from a landscape with a flat prior
distribution of cosmological constant Lambda gives a reasonable fit to
observation. However, a realistic model of the multiverse has a physical volume
that diverges with time, and the predicted distribution of Lambda depends on
how the spacetime volume is regulated. We study a simple model of the
multiverse with probabilities regulated by a scale-factor cutoff, and calculate
the resulting distribution, considering both positive and negative values of
Lambda. The results are in good agreement with observation. In particular, the
scale-factor cutoff strongly suppresses the probability for values of Lambda
that are more than about ten times the observed value. We also discuss several
qualitative features of the scale-factor cutoff, including aspects of the
distributions of the curvature parameter Omega and the primordial density
contrast Q.


title:
Carbon monoxide line emission as a CMB foreground: tomography of the
  star-forming universe with different spectral resolutions

abstract:
  The rotational lines of carbon monoxide and the fine structure lines of CII
and of the most abundant metals, emitted during the epoch of enhanced star
formation in the universe, are redshifted in the frequency channels where the
present-day and future CMB experiments are sensitive. We estimate the
contribution to the CMB angular power spectrum by the emission in such lines in
merging star-forming galaxies. We used the Lacey-Cole approach to characterize
the distribution of the merging halos, together with a parametrization for the
star formation rate in each of them. Using observational data from a sample of
local, low-redshift, and high-redshift objects, we calibrated the luminosity in
each line as a function of the star formation rate. We show that the
correlation term arising from CO line emission is a significant source of
foreground for CMB in a broad range of frequencies (in particular in the 20-60
GHz band) and for 1000<l<8000, corresponding to angular scales smaller than 10
arcminutes. Moreover, we demonstrate that observing with different spectral
resolutions will give the possibility of increasing the amplitude of the signal
up to two orders of magnitude in C_l and will help separate the line
contribution from practically all other foreground sources and from the primary
fluctuations themselves, since these show no significant dependence on the
spectral resolution. We propose to perform observations with varying spectral
bandwidths as a new tool to construct a tomography of the universe, by probing
different redshift slices with varying thickness. (abridged)


title: Single top quark production at the Tevatron

abstract:
  The Tevatron experiments D0 and CDF have found evidence for single top quark
production, based on datasets between 0.9fb-1 and 2.2fb^-1. Several different
multivariate techniques are used to extract the single top quark signal out of
the large backgrounds. The cross section measurements are also used to provide
the first direct measurement of the CKM matrix element |Vtb|.


title:
On the Convergence of the Convectively Filtered Burgers Equation to the
  Entropy Solution of the Inviscid Burgers Equation

abstract:
  This document provides a proof that the solutions to the convectively
filtered Burgers equation, will converge to the entropy solution of the
inviscid Burgers equation when certain restrictions are put on the initial
conditions. It does so by first establishing convergence to a weak solution of
the inviscid Burgers equation and then showing that the weak solution is the
entropy solution. Then the results are extended to encompass more general
initial conditions.


title: Local interactions and non-Abelian quantum loop gases

abstract:
  Two-dimensional quantum loop gases are elementary examples of topological
ground states with Abelian or non-Abelian anyonic excitations. While Abelian
loop gases appear as ground states of local, gapped Hamiltonians such as the
toric code, we show that gapped non-Abelian loop gases require non-local
interactions (or non-trivial inner products). Perturbing a local, gapless
Hamiltonian with an anticipated ``non-Abelian'' ground-state wavefunction
immediately drives the system into the Abelian phase, as can be seen by
measuring the Hausdorff dimension of loops. Local quantum critical behavior is
found in a loop gas in which all equal-time correlations of local operators
decay exponentially.


title: Orderings of the rationals and dynamical systems

abstract:
  This paper is devoted to a systematic study of a class of binary trees
encoding the structure of rational numbers both from arithmetic and dynamical
point of view. The paper is divided into two parts. The first one is a critical
review of rather standard topics such as Stern-Brocot and Farey trees and their
connections with continued fraction expansion and the question mark function.
In the second part we introduce a class of one-dimensional maps which can be
used to generate the binary trees in different ways and study their ergodic
properties. This also leads us to study some random processes (Markov chains
and martingales) arising in a natural way in this context.


title: Mnesors for databases

abstract:
  We add commutativity to axioms defining mnesors and substitute a bitrop for
the lattice. We show that it can be applied to relational database querying:
set union, intersection and selection are redifined only from the mnesor
addition and the granular multiplication. Union-compatibility is not required.


title: Quantum Metrology: Dynamics vs. Entanglement

abstract:
  A parameter whose coupling to a quantum probe of $n$ constituents includes
all two-body interactions between the constituents can be measured with an
uncertainty that scales as $1/n^{3/2}$, even when the constituents are
initially unentangled. We devise a protocol that achieves the $1/n^{3/2}$
scaling without generating any entanglement among the constituents, and we
suggest that the protocol might be implemented in a two-component Bose-Einstein
condensate.


title:
Fundamentals of Non-relativistic Collisionless Shock Physics: III.
  Quasi-Perpendicular Supercritical Shocks

abstract:
  The theory and simulations of quasi-perpendicular and strictly perpendicular
collisionless shocks are reviewed. The text is structured into the following
sections and subsections: 1. Setting the frame, where the quasi-perpendicular
shock problem is formulated, reflected particle dynamics is described in
theoretical terms, foot formation and foot ion acceleration discussed, and the
shock potential explained. 2. Shock structure, 3. Ion dynamics, describing its
role in shock reformation and the various ion-excited instabilities. 4.
Electron dynamics, describing electron instabilities in the foot; 5. The
problem of stationarity, posing the theoretical reasons for shocks being
non-stationary, discussing nonlinear whistler mediated variability, two-stream
and modified two-stream variability, formation of ripples in two-dimensions, 6.
Summary and conclusions: The possibility of shock breaking.


title: On the decrease of intermittency in decaying rotating turbulence

abstract:
  The scaling of the longitudinal velocity structure functions, $S_q(r) = < |
\delta u (r) |^q > \sim r^{\zeta_q}$, is analyzed up to order $q=8$ in a
decaying rotating turbulence experiment from a large Particle Image Velocimetry
(PIV) dataset. The exponent of the second-order structure function, $\zeta_2$,
increases throughout the self-similar decay regime, up to the Ekman time scale.
The normalized higher-order exponents, $\zeta_q / \zeta_2$, are close to those
of the intermittent non-rotating case at small times, but show a marked
departure at larger times, on a time scale $\Omega^{-1}$ ($\Omega$ is the
rotation rate), although a strictly non-intermittent linear law $\zeta_q /
\zeta_2 = q/2$ is not reached.


title: Gravity and its Mysteries: Some Thoughts and Speculations

abstract:
  I gave a rambling talk about gravity and its many mysteries at Chen-Ning
Yang's 85th Birthday Celebration held in November 2007. I don't have any
answers.


title: A new outburst in LMC-N66

abstract:
  This is the first report on the new outburst presented by the central star of
the LMC-N66 nebula. This object was classified as a planetary nebula, however,
its true nature is under debate. In the period 1955-1990 the central star was
almost undetectable and only nebular emission lines were observed. In 1990, the
beginning of an outburst was detected and in few months it became much brighter
and developed wide He and N lines, typical of a Wolf Rayet star of the
N-sequence. The maximum occurred in 1994 and afterwards the star slowly faded.
Analysis of its evolution showed that it has a variable mass-loss rate which
occasionally increases enormously, creating a false photosphere at a much
larger radius, making it appear a few magnitudes brighter. The present outburst
has occurred 13 years after the episode from 1994 to 2000. So far this new
event has similar characteristics although there are some significant
differences in the spectral features. We present optical and FUSE spectra
showing the main properties of this latter event.


title:
Path Diversity over Packet Switched Networks: Performance Analysis and
  Rate Allocation

abstract:
  Path diversity works by setting up multiple parallel connections between the
end points using the topological path redundancy of the network. In this paper,
\textit{Forward Error Correction} (FEC) is applied across multiple independent
paths to enhance the end-to-end reliability. Network paths are modeled as
erasure Gilbert-Elliot channels. It is known that over any erasure channel,
\textit{Maximum Distance Separable} (MDS) codes achieve the minimum probability
of irrecoverable loss among all block codes of the same size. Based on the
adopted model for the error behavior, we prove that the probability of
irrecoverable loss for MDS codes decays exponentially for an asymptotically
large number of paths. Then, optimal rate allocation problem is solved for the
asymptotic case where the number of paths is large. Moreover, it is shown that
in such asymptotically optimal rate allocation, each path is assigned a
positive rate \textit{iff} its quality is above a certain threshold. The
quality of a path is defined as the percentage of the time it spends in the bad
state. Finally, using dynamic programming, a heuristic suboptimal algorithm
with polynomial runtime is proposed for rate allocation over a finite number of
paths. This algorithm converges to the asymptotically optimal rate allocation
when the number of paths is large. The simulation results show that the
proposed algorithm approximates the optimal rate allocation (found by
exhaustive search) very closely for practical number of paths, and provides
significant performance improvement compared to the alternative schemes of rate
allocation.


title:
MuSR studies of RE(O,F)FeAs (RE = La, Nd, Ce) and LaOFeP systems:
  possible incommensurate/stripe magnetism and superfluid density

abstract:
  Muon spin relaxation (MuSR) measurements in iron oxy-pnictide systems have
revealed: (1) commensurate long-range order in undoped LaOFeAs; (2) Bessel
function line shape in La(O0.97F0.03)FeAs which indicates possible
incommensurate or stripe magnetism; (3) anomalous weak magnetism existing in
superconducting LaOFeP, Ce(O0.84F0.16)FeAs, and Nd(O0.88F0.12)FeAs but absent
in superconducting La(O0.92F0.08)FeAs; and (4) scaling of superfluid density
and Tc in the Ce, La, and Nd-FeAs superconductors following a nearly linear
relationship found in cuprates.


title: Yoneda representations of flat functors and classifying toposes

abstract:
  In this paper, we first introduce a technique that we call "Yoneda
representation of flat functors", based on ideas from indexed category theory;
then we provide applications of this technique to the theory of classifying
toposes. Specifically, we obtain results characterizing the models of a theory
classified by a topos of the form Sh(C,J) in terms of the models of a theory
classified by the topos [C^op, Set].


title: Three-Dimensional Percolation Modeling of Self-Healing Composites

abstract:
  We study the self-healing process of materials with embedded "glue"-carrying
cells, in the regime of the onset of the initial fatigue. Three-dimensional
numerical simulations within the percolation-model approach are reported. The
main numerical challenge taken up in the present work, has been to extend the
calculation of the conductance to three-dimensional lattices. Our results
confirm the general features of the process: The onset of the material fatigue
is delayed, by developing a plateau-like time-dependence of the material
quality. We demonstrate that in this low-damage regime, the changes in the
conductance and thus, in similar transport/response properties of the material
can be used as measures of the material quality degradation. A new feature
found for three dimensions, where it is much more profound than in
earlier-studied two-dimensional systems, is the competition between the healing
cells. Even for low initial densities of the healing cells, they interfere with
each other and reduce each other's effective healing efficiency.


title: Visual Checking of Spreadsheets

abstract:
  The difference between surface and deep structures of a spreadsheet is a
major cause of difficulty in checking spreadsheets. After a brief survey of
current methods of checking (or debugging) spreadsheets, new visual methods of
showing the deep structures are presented. Illustrations are given on how these
visual methods can be employed in various interactive local and global
debugging strategies.


title:
Emission from dielectric cavities in terms of invariant sets of the
  chaotic ray dynamics

abstract:
  In this paper, the chaotic ray dynamics inside dielectric cavities is
described by the properties of an invariant chaotic saddle. I show that the
localization of the far field emission in specific directions is related to the
filamentary pattern of the saddle's unstable manifold, along which the energy
inside the cavity is distributed. For cavities with mixed phase space, the
chaotic saddle is divided in hyperbolic and non-hyperbolic components, related,
respectively, to the intermediate exponential (t<t_c) and the asymptotic
power-law (t>t_c) decay of the energy inside the cavity. The alignment of the
manifolds of the two components of the saddle explains why even if the energy
concentration inside the cavity dramatically changes from t<t_c to t>t_c, the
far field emission changes only slightly. Simulations in the annular billiard
confirm and illustrate the predictions.


title: Intergalactic baryon-rich regions at high redshift

abstract:
  Using a high resolution cosmological simulation of reionization we have
examined the differing structures formed by gas and dark matter at a redshift
of 5.1. Baryon-rich regions form a small number of filaments, which connect the
largest galaxies in the simulation. More detailed examination of the ten
largest galaxies reveals long, slender gaseous filaments about 5 proper kpc in
width radiating from the galaxy centers. Extending out from each filament are a
few smooth, thin, nearly planar gaseous sheets. By contrast, the dark matter
concentrates into quasi-spherical bodies. The results have implications for our
understanding of structure formation in the early universe and of the Lyman
alpha forest.


title: On the moduli space of Donaldson-Thomas instantons

abstract:
  In alignment with a programme by Donaldson and Thomas [DT], Thomas [Th]
constructed a deformation invariant for smooth projective Calabi-Yau
threefolds, which is now called the Donaldson-Thomas invariant, from the moduli
space of (semi-)stable sheaves by using algebraic geometry techniques. In the
same paper [Th], Thomas noted that certain perturbed Hermitian-Einstein
equations might possibly produce an analytic theory of the invariant. This
article sets up the equations on symplectic 6-manifolds, and gives the local
model and structures of the moduli space coming from the equations. We then
describe a Hitchin-Kobayashi style correspondence for the equations on compact
K\"ahler threefolds, which turns out to be a special case of results by
Alvarez-Consul and Garcia-Prada [AG].


title:
Ultra fast quantum key distribution over a 97 km installed telecom fiber
  with wavelength-division multiplexing clock synchronization

abstract:
  We demonstrated ultra fast BB84 quantum key distribution (QKD) transmission
at 625 MHz clock rate through a 97 km field-installed fiber using practical
clock synchronization based on wavelength-division multiplexing (WDM). We
succeeded in over-one-hour stable key generation at a high sifted key rate of
2.4 kbps and a low quantum bit error rate (QBER) of 2.9%. The asymptotic secure
key rate was estimated to be 0.78-0.82 kbps from the transmission data with the
decoy method of average photon numbers 0, 0.15, and 0.4 photons/pulse.


title:
Scaling and Memory Effect in Volatility Return Interval of the Chinese
  Stock Market

abstract:
  We investigate the probability distribution of the volatility return
intervals $\tau$ for the Chinese stock market. We rescale both the probability
distribution $P_{q}(\tau)$ and the volatility return intervals $\tau$ as
$P_{q}(\tau)=1/\bar{\tau} f(\tau/\bar{\tau})$ to obtain a uniform scaling curve
for different threshold value $q$. The scaling curve can be well fitted by the
stretched exponential function $f(x) \sim e^{-\alpha x^{\gamma}}$, which
suggests memory exists in $\tau$. To demonstrate the memory effect, we
investigate the conditional probability distribution $P_{q} (\tau|\tau_{0})$,
the mean conditional interval $<\tau|\tau_{0}>$ and the cumulative probability
distribution of the cluster size of $\tau$. The results show clear clustering
effect. We further investigate the persistence probability distribution
$P_{\pm}(t)$ and find that $P_{-}(t)$ decays by a power law with the exponent
far different from the value 0.5 for the random walk, which further confirms
long memory exists in $\tau$. The scaling and long memory effect of $\tau$ for
the Chinese stock market are similar to those obtained from the United States
and the Japanese financial markets.


title:
A weak compactness theorem of the Donaldson-Thomas instantons on compact
  K\"ahler threefolds

abstract:
  In arXiv:0805.2192, we set up a gauge-theoretic equation on symplectic
6-manifolds, which is a version of the Hermitian-Einstein equation perturbed by
Higgs fields, and call Donaldson-Thomas equation, to analytically approach the
Donaldson-Thomas invariants. In this article, we consider the equation on
compact K\"ahler threefolds, and study some of analytic properties of solutions
to them, using analytic methods in higher-dimensional Yang-Mills theory
developed by Nakajima and Tian with some additional arguments concerning an
extra non-linear term coming from the Higgs fields. We prove that a sequence of
solutions to the Donaldson-Thomas equation of a unitary vector bundle over a
compact K\"ahler threefold has a converging subsequence outside a closed subset
whose real 2-dimensional Hausdorff measure is finite, provided that the
L^2-norms of the Higgs fields are uniformly bounded. We also prove an
n/2-compactness theorem of solutions to the equations on compact K\"ahler
threefolds.


title:
The Donaldson-Thomas instantons on compact Kahler threefolds and a
  convergence

abstract:
  The contents of this article are now presented in the appendix of
arXiv:0805.2195v2.


title: Cosmological Radar Ranging in an Expanding Universe

abstract:
  While modern cosmology, founded in the language of general relativity, is
almost a century old, the meaning of the expansion of space is still being
debated. In this paper, the question of radar ranging in an expanding universe
is examined, focusing upon light travel times during the ranging; it has
recently been claimed that this proves that space physically expands. We
generalize the problem into considering the return journey of an accelerating
rocketeer, showing that while this agrees with expectations of special
relativity for an empty universe, distinct differences occur when the universe
contains matter. We conclude that this does not require the expansion of space
to be a physical phenomenon, rather that we cannot neglect the influence of
matter, seen through the laws of general relativity, when considering motions
on cosmic scales.


title:
Emission line profiles as a probe of physical conditions in planetary
  nebulae

abstract:
  We present an analysis of physical conditions in planetary nebulae (PNe) in
terms of collisionally-excited line (CEL) and optical-recombination line (ORL)
profiles. We aim to investigate whether line profiles could be used to study
the long-standing CEL/ORL abundance-discrepancy problem in nebular
astrophysics. Using 1D photoionization models and their assumed velocity
fields, we simulate the line profiles of various ionic species. We attempt to
use our model to account for the observed CEL and ORL profiles. As a case study
we present a detailed study of line profiles of the low-excitation planetary
nebula (PN) IC 418. Our results show that the profiles of classical temperature
and density diagnostic lines, such as [O III] 4363,5007, [S II] 6716,6731, and
[Ar IV] 4711,4740, provide a powerful tool to study nebular temperature and
density variations. The method enables the CEL/ORL abundance-discrepancy
problem to be studied more rigorously than before. A pure photoionization model
of a chemically-homogeneous nebula seems to explain the observed disagreements
in the profiles for the [O III] 4363 and the 5007 lines, but cannot account for
the differences between the [O III] CELs and the O II ORLs. We also investigate
the temperature and density variations in the velocity space of a sample of
PNe, which are found to be insignificant.


title:
Constraint Complexity of Realizations of Linear Codes on Arbitrary
  Graphs

abstract:
  A graphical realization of a linear code C consists of an assignment of the
coordinates of C to the vertices of a graph, along with a specification of
linear state spaces and linear ``local constraint'' codes to be associated with
the edges and vertices, respectively, of the graph. The $\k$-complexity of a
graphical realization is defined to be the largest dimension of any of its
local constraint codes. $\k$-complexity is a reasonable measure of the
computational complexity of a sum-product decoding algorithm specified by a
graphical realization. The main focus of this paper is on the following
problem: given a linear code C and a graph G, how small can the $\k$-complexity
of a realization of C on G be? As useful tools for attacking this problem, we
introduce the Vertex-Cut Bound, and the notion of ``vc-treewidth'' for a graph,
which is closely related to the well-known graph-theoretic notion of treewidth.
Using these tools, we derive tight lower bounds on the $\k$-complexity of any
realization of C on G. Our bounds enable us to conclude that good
error-correcting codes can have low-complexity realizations only on graphs with
large vc-treewidth. Along the way, we also prove the interesting result that
the ratio of the $\k$-complexity of the best conventional trellis realization
of a length-n code C to the $\k$-complexity of the best cycle-free realization
of C grows at most logarithmically with codelength n. Such a logarithmic growth
rate is, in fact, achievable.


title:
Infall of planetesimals onto growing giant planets: onset of runaway gas
  accretion and metallicity of their gas envelopes

abstract:
  We have investigated the planetesimal accretion rate onto giant planets that
are growing through gas accretion, using numerical simulations and analytical
arguments. We derived the condition for gap opening in the planetesimal disk,
which is determined by a competition between the expansion of the planet's Hill
radius due to the planet growth and the damping of planetesimal eccentricity
due to gas drag. We also derived the semi-analytical formula for the
planetesimal accretion rate as a function of ratios of the rates of the Hill
radius expansion, the damping, and planetesimal scattering by the planet. The
predicted low planetesimal accretion rate due to gap opening in early gas
accretion stages quantitatively shows that "phase 2," which is a long slow gas
accretion phase before onset of runaway gas accretion, is not likely to occur.
In late stages, rapid Hill radius expansion fills the gap, resulting in
significant planetesimal accretion, which is as large as several $M_{\oplus}$
for Jupiter and Saturn. The efficient onset of runaway gas accretion and the
late pollution may reconcile the ubiquity of extrasolar giant planets with
metal-rich envelopes of Jupiter and Saturn inferred from interior structure
models. These formulae will give deep insights into formation of extrasolar gas
giants and the diversity in metallicity of transiting gas giants.


title:
From Shock Breakout to Peak and Beyond: Extensive Panchromatic
  Observations of the Type Ib Supernova 2008D associated with Swift X-ray
  Transient 080109

abstract:
  We present extensive early photometric (ultraviolet through near-infrared)
and spectroscopic (optical and near-infrared) data on supernova (SN) 2008D as
well as X-ray data analysis on the associated Swift/X-ray transient (XRT)
080109. Our data span a time range of 5 hours before the detection of the X-ray
transient to 150 days after its detection, and detailed analysis allowed us to
derive constraints on the nature of the SN and its progenitor; throughout we
draw comparisons with results presented in the literature and find several key
aspects that differ. We show that the X-ray spectrum of XRT 080109 can be fit
equally well by an absorbed power law or a superposition of about equal parts
of both power law and blackbody. Our data first established that SN 2008D is a
spectroscopically normal SN Ib (i.e., showing conspicuous He lines), and show
that SN 2008D had a relatively long rise time of 18 days and a modest optical
peak luminosity. The early-time light curves of the SN are dominated by a
cooling stellar envelope (for \Delta t~0.1- 4 day, most pronounced in the blue
bands) followed by 56^Ni decay. We construct a reliable measurement of the
bolometric output for this stripped-envelope SN, and, combined with estimates
of E_K and M_ej from the literature, estimate the stellar radius R_star of its
probable Wolf-Rayet progenitor. According to the model of Waxman et al. and of
Chevalier & Fransson, we derive R_star^{W07}= 1.2+/-0.7 R_sun and
R_star^{CF08}= 12+/-7 R_sun, respectively; the latter being more in line with
typical WN stars. Spectra obtained at 3 and 4 months after maximum light show
double-peaked oxygen lines that we associate with departures from spherical
symmetry, as has been suggested for the inner ejecta of a number of SN Ib
cores.


title:
Identification of Bottom Contribution in Non-photonic Electron Spectra
  and $v_2$ at RHIC

abstract:
  We present a study on the spectra for heavy flavor (charm and bottom) decayed
electrons in 200 GeV $p+p$ collisions and provide the relative contributions of
charm and bottom hadrons from the PYTHIA calculations. The results suggest that
the crossing point of the electron spectra from charm and bottom decays is
above 7 GeV/$c$ and bottom contribution is not dominant for electron $p_{T}<3$
GeV/$c$. The upper limit of the relative cross section ratio is reported as
$\sigma_{b\bar{b}}/\sigma_{c\bar{c}}\leq(0.49\pm0.09\pm0.09)%$. We also compare
the $v_2$ distribution from simulation to the experimental data in 200 GeV
$Au+Au$ collisions and estimate the possible charm $v_2$.


title: Hopf Algebra Symmetry and String Theory

abstract:
  We investigate the Hopf algebra structure in string worldsheet theory and
give a unified formulation of the quantization of string and the space-time
symmetry. We reformulate the path integral quantization of string as a Drinfeld
twist at the worldsheet level. The coboundary relation shows that the Drinfeld
twist defines a module algebra which is equivalent to operators with normal
ordering. Upon applying the twist, the space-time diffeomorphism is deformed
into a twisted Hopf algebra, while the Poincar\'e symmetry is unchanged. This
suggests a characterization of the symmetry: unbroken symmetries are twist
invariant Hopf subalgebras, while broken symmetries are realized as twisted
ones. We provide arguments that relate this twisted Hopf algebra to symmetries
in path integral quantization.


title:
Role of the Majorana Fermion and the Edge Mode in Chiral Superfluidity
  near a p-Wave Feshbach Resonance

abstract:
  The visualization of chiral p-wave superfluidity in Fermi gases near p-wave
Feshbach resonances is theoretically examined. It is proposed that the
superfluidity becomes detectable in the entire BCS-BEC regimes through (i)
vortex visualization by the density depletion inside the vortex core and (ii)
intrinsic angular momentum in vortex free states. It is revealed that both (i)
and (ii) are closely connected with the Majorana zero energy mode of the vortex
core and the edge mode, which survive until the strong coupling BCS regime is
approached from the weak coupling limit and vanish in the BEC regime.


title: Mass formula for self-orthogonal codes over Z_{p^2}

abstract:
  In this note, we establish a mass formula for self-orthogonal codes over
Z_{p^2}, where p is a prime. As a consequence, an alternative proof of the
known mass formulas for self-dual codes over Z_{p^2} is obtained. We also
establish a mass formula for even quaternary codes, which includes a mass
formula for Type II quaternary codes as a special case.


title: Chirality-Selective Excitation of Coherent Phonons in Carbon Nanotubes

abstract:
  Using pre-designed trains of femtosecond optical pulses, we have selectively
excited coherent phonons of the radial breathing mode of specific-chirality
single-walled carbon nanotubes within an ensemble sample. By analyzing the
initial phase of the phonon oscillations, we prove that the tube diameter
initially increases in response to ultrafast photoexcitation. Furthermore, from
excitation profiles, we demonstrate that an excitonic absorption peak of carbon
nanotubes periodically oscillates as a function of time when the tube diameter
undergoes radial breathing mode oscillations.


title: Chandra Cluster Cosmology Project II: Samples and X-ray Data Reduction

abstract:
  We discuss the measurements of the galaxy cluster mass functions at z=~0.05
and z=~0.5 using high-quality Chandra observations of samples derived from the
ROSAT PSPC All-Sky and 400deg^2 surveys. We provide a full reference for the
data analysis procedures, present updated calibration of relations between the
total cluster mass and its X-ray indicators (T_X, Mgas, and Y_X) based on a
subsample of low-z relaxed clusters, and present a first measurement of the
evolving L_X-Mtot relation (with Mtot estimated from Y_X) obtained from a
well-defined statistically complete cluster sample and with appropriate
corrections for the Malmquist bias applied. Finally, we present the derived
cluster mass functions, estimate the systematic uncertainties in this
measurement, and discuss the calculation of the likelihood function. We
confidently measure the evolution in the cluster comoving number density at a
fixed mass threshold, e.g., by a factor of 5.0 +- 1.2 at M_500=2.5e14 h^-1 Msun
between z=0 and 0.5. This evolution reflects the growth of density
perturbations and can be used for the cosmological constraints complementing
those from the distance-redshift relation.


title: Origin of dwarf irregular galaxies with outer early-type structures

abstract:
  Recent observations have reported that some gas-rich dwarf irregular (dIrr)
galaxies appear to have spherical distributions in the outer underlying old and
intermediate-age stellar populations (e.g., NGC 6822). These observations imply
that some dIrr's have two distinct (or ``two-component'') structures, i.e.,
inner disky and outer spherical ones, though the number fraction of dIrr's with
such structures remains observationally unclear. We discuss how such two
distinct structures are formed during dIrr formation based on observations and
simulations. Our numerical simulations show that the remnants of mergers
between two gas-rich dIrr's with initially extended gas disks can have both
extended spheroids composed of older stellar populations and disks composed
mostly of gas and young stars. The simulated remnants with two distinct
structures can be still identified as dIrr's owing to the presence of
star-forming regions. The structural properties of outer spherical structures
in dIrr's formed from dIrr-dIrr merging depend on initial conditions of
merging, which suggests that outer structures in dIrr's can be diverse. We also
discuss other possible physical mechanisms for the formation of outer spherical
structures composed of older stars in dIrr's.


title: Properties of Local Quantum Operations with Shared Entanglement

abstract:
  Multi-party local quantum operations with shared quantum entanglement or
shared classical randomness are studied. The following facts are established:
  (i) There is a ball of local operations with shared randomness lying within
the space spanned by the no-signaling operations and centred at the completely
noisy channel.
  (ii) The existence of the ball of local operations with shared randomness is
employed to prove that the weak membership problem for local operations with
shared entanglement is strongly NP-hard.
  (iii) Local operations with shared entanglement are characterized in terms of
linear functionals that are ``completely'' positive on a certain cone K of
separable Hermitian operators, under a natural notion of complete positivity
appropriate to that cone. Local operations with shared randomness (but not
entanglement) are also characterized in terms of linear functionals that are
merely positive on that same cone K.
  (iv) Existing characterizations of no-signaling operations are generalized to
the multi-party setting and recast in terms of the Choi-Jamiolkowski
representation for quantum super-operators. It is noted that the standard
nonlocal box is an example of a no-signaling operation that is separable, yet
cannot be implemented by local operations with shared entanglement.


title:
Dynamical Casimir effect for magnons in a spinor Bose-Einstein
  condensate

abstract:
  Magnon excitation in a spinor Bose-Einstein condensate by a driven magnetic
field is shown to have a close analogy with the dynamical Casimir effect. A
time-dependent external magnetic field amplifies quantum fluctuations in the
magnetic ground state of the condensate, leading to magnetization of the
system. The magnetization occurs in a direction perpendicular to the magnetic
field breaking the rotation symmetry. This phenomenon is numerically
demonstrated and the excited quantum field is shown to be squeezed.


title: Weakly disordered absorbing-state phase transitions

abstract:
  The effects of quenched disorder on nonequilibrium phase transitions in the
directed percolation universality class are revisited. Using a strong-disorder
energy-space renormalization group, it is shown that for any amount of disorder
the critical behavior is controlled by an infinite-randomness fixed point in
the universality class of the random transverse-field Ising models. The
experimental relevance of our results are discussed.


title:
Evidence of valence band perturbations in GaAsN/GaAs(001): A combined
  variable-angle spectroscopic ellipsometry and modulated photoreflectance
  investigation

abstract:
  The contribution of the fundamental gap E_ as well as those of the E_ +
Delta(so) and E+ transitions to the dielectric function of GaAs1-xNx alloys
near the band edge were determined from variable-angle spectroscopic
ellipsometry and modulated photoreflectance spectroscopy analyses. The
oscillator strength of the E_ optical transition increases weakly with nitrogen
incorporation. The two experimental techniques independently reveal that not
only the oscillator strength of the E+ transition but also that of E_ +
Delta(so) become larger compared to that of the fundamental gap as the N
content increases. Since the same conduction band is involved in both the E_
transition and its split-off replica, these results reveal that adding nitrogen
in GaAs1-xNx alloys affects not only the conduction but also the valence bands.


title: Monovacancy-induced magnetism in graphene bilayers

abstract:
  Vacancy-induced magnetism in graphene bilayers is investigated using
spin-polarized density functional theory calculations. One of two graphene
layers has a monovacancy. Two atomic configurations for bilayers are considered
with respect to the position of the monovacancy. We find that spin magnetic
moments localized at the vacancy site decreases by ~10 % for our two
configurations, compared with the graphene monolayer with a monovacancy. The
reduction of the spin magnetic moment in the graphene bilayers is attributed to
the interlayer charge transfer from the adjacent layer to the layer with the
monovacancy, compensating for spin magnetic moments originating from
quasilocalized defect state.


title: Augmented GARCH sequences: Dependence structure and asymptotics

abstract:
  The augmented GARCH model is a unification of numerous extensions of the
popular and widely used ARCH process. It was introduced by Duan and besides
ordinary (linear) GARCH processes, it contains exponential GARCH, power GARCH,
threshold GARCH, asymmetric GARCH, etc. In this paper, we study the
probabilistic structure of augmented $\mathrm {GARCH}(1,1)$ sequences and the
asymptotic distribution of various functionals of the process occurring in
problems of statistical inference. Instead of using the Markov structure of the
model and implied mixing properties, we utilize independence properties of
perturbed GARCH sequences to directly reduce their asymptotic behavior to the
case of independent random variables. This method applies for a very large
class of functionals and eliminates the fairly restrictive moment and
smoothness conditions assumed in the earlier theory. In particular, we derive
functional CLTs for powers of the augmented GARCH variables, derive the error
rate in the CLT and obtain asymptotic results for their empirical processes
under nearly optimal conditions.


title:
Field-induced quantum critical route to a Fermi liquid in
  high-temperature superconductors

abstract:
  In high transition temperature (T_c) superconductivity, charge doping is a
natural tuning parameter that takes copper oxides from the antiferromagnet to
the superconducting region. In the metallic state above T_c the standard
Landau's Fermi-liquid theory of metals as typified by the temperature squared
(T^2) dependence of resistivity appears to break down. Whether the origin of
the non-Fermi-liquid behavior is related to physics specific to the cuprates is
a fundamental question still under debate. We uncover a new transformation from
the non-Fermi- to a standard Fermi-liquid state driven not by doping but by
magnetic field in the overdoped high-T_c superconductor Tl_2Ba_2CuO_{6+x}. From
the c-axis resistivity measured up to 45 T, we show that the Fermi-liquid
features appear above a sufficiently high field which decreases linearly with
temperature and lands at a quantum critical point near the superconductivity's
upper critical field -- with the Fermi-liquid coefficient of the T^2 dependence
showing a power-law diverging behavior on the approach to the critical point.
This field-induced quantum criticality bears a striking resemblance to that in
quasi-two dimensional heavy-Fermion superconductors, suggesting a common
underlying spin-related physics in these superconductors with strong electron
correlations.


title: Density estimation with heteroscedastic error

abstract:
  It is common, in deconvolution problems, to assume that the measurement
errors are identically distributed. In many real-life applications, however,
this condition is not satisfied and the deconvolution estimators developed for
homoscedastic errors become inconsistent. In this paper, we introduce a kernel
estimator of a density in the case of heteroscedastic contamination. We
establish consistency of the estimator and show that it achieves optimal rates
of convergence under quite general conditions. We study the limits of
application of the procedure in some extreme situations, where we show that, in
some cases, our estimator is consistent, even when the scaling parameter of the
error is unbounded. We suggest a modified estimator for the problem where the
distribution of the errors is unknown, but replicated observations are
available. Finally, an adaptive procedure for selecting the smoothing parameter
is proposed and its finite-sample properties are investigated on simulated
examples.


title: Growth of Oxide Compounds under Dynamic Atmosphere Composition

abstract:
  Commercially available gases contain residual impurities leading to a
background oxygen partial pressure of typically several 10^{-6} bar,
independent of temperature. This oxygen partial pressure is inappropriate for
the growth of some single crystals where the desired oxidation state possesses
a narrow stability field. Equilibrium thermodynamic calculations allow the
determination of dynamic atmosphere compositions yielding such self adjusting
and temperature dependent oxygen partial pressures, that crystals like ZnO,
Ga2O3, or Fe{1-x}O can be grown from the melt.


title:
Antiferromagnetic Nuclear Resonance in the Quasi-Two-Dimensional
  (CuBr)LaNb2O7

abstract:
  We report nuclear magnetic resonance (NMR) studies in the antiferromagnetic
state of the quasi-two-dimensional (CuBr)LaNb2O7. The NMR spectra at zero
magnetic field and 4.2 K indicate a unique Cu and Br sites with an internal
field of 5.7 T (at Cu) and 16.4 T (at Br), confirming a magnetic order. For the
large internal field at the Br sites to be compatible with the collinear
antiferromagnetic order observed by neutron diffraction experiments (N. Oba et
al., J. Phys. Soc. Jpn. 75, (2006) 113601), the Br atoms must move
significantly off the center of the square of the Cu sublattice so that the Br
nuclei couple predominantly to two parallel Cu moments. While invalidating the
frustrated J1-J2 model defined on a C4-symmetric square lattice, our results
are compatible with the structural model proposed for (CuCl)LaNb2O7 by Yoshida
et al. (J. Phys. Soc. Jpn. 76 (2007) 104703).


title:
Consistency of the $\alpha$-trimming of a probability. Applications to
  central regions

abstract:
  The sequence of $\alpha$-trimmings of empirical probabilities is shown to
converge, in the Painlev\'{e}--Kuratowski sense, on the class of probability
measures endowed with the weak topology, to the $\alpha$-trimming of the
population probability. Such a result is applied to the study of the asymptotic
behaviour of central regions based on the trimming of a probability.


title: Quantum Tunneling Beyond Semiclassical Approximation

abstract:
  Hawking radiation as tunneling by Hamilton-Jacobi method beyond semiclassical
approximation is analysed. We compute all quantum corrections in the single
particle action revealing that these are proportional to the usual
semiclassical contribution. We show that a simple choice of the proportionality
constants reproduces the one loop back reaction effect in the spacetime, found
by conformal field theory methods, which modifies the Hawking temperature of
the black hole. Using the law of black hole mechanics we give the corrections
to the Bekenstein-Hawking area law following from the modified Hawking
temperature. Some examples are explicitly worked out.


title: High energy gamma-ray emission from Gamma-Ray Bursts -- before GLAST

abstract:
  Gamma-ray bursts (GRBs) are short and intense emission of soft gamma-rays,
which have fascinated astronomers and astrophysicists since their unexpected
discovery in 1960s. The X-ray/optical/radio afterglow observations confirm the
cosmological origin of GRBs, support the fireball model, and imply a
long-activity of the central engine. The high energy gamma-ray emission (>20
MeV) from GRBs is particularly important because they shed some lights on the
radiation mechanisms and can help us to constrain the physical processes giving
rise to the early afterglows. In this work, we review observational and
theoretical studies of the high energy emission from GRBs. Special attention is
given to the expected high energy emission signatures accompanying the
canonical early-time X-ray afterglow that was observed by the Swift X-ray
Telescope. We also discuss the detection prospect of the upcoming GLAST
satellite and the current ground-based Cerenkov detectors.


title: The Kl3 scalar form factors in the standard model

abstract:
  We discuss the predictions of the standard model for the scalar form factors
of Kl3 decays. Our analysis is based on the results of chiral perturbation
theory, large Nc estimates of low-energy couplings and dispersive methods. It
includes a discussion of isospin violating effects of strong and
electromagnetic origin.


title: Higgs Production via b bbar -> H in Hadron Colliders

abstract:
  I present NNNLO collinear and soft gluon corrections for Higgs production via
the process b bbar -> H. I show that the collinear corrections dominate and
contribute large enhancements to the cross section at both the Tevatron and the
LHC.


title: A New Differential Test for Series of Positive Terms

abstract:
  A new differential test for series of positive terms is proved. Let f(x) be a
positive continuous function corresponded to a series of positive terms f(k),
and g(x) is a derivative of reciprocal of f(x). Then, the convergence and
divergence of the series may be determined from a value of fgx for enough large
x. The rest may make the limit form, and is universal and complete.


title: Sub-10ps Monolithic and Low-power Photodetector Readout

abstract:
  Recent advances in photon detectors have resulted in high-density imaging
arrays that offer many performance and cost advantages. In particular, the
excellent transit time spread of certain devices show promise to provide
tangible benefits in applications such as Positron Emission Tomography (PET).
Meanwhile, high-density, high-performance readout techniques have not kept on
pace for exploiting these developments. Photodetector readout for next
generation high event rate particle identification and time-resolved PET
requires a highly-integrated, low-power, and cost-effective readout technique.
We propose fast waveform sampling as a method that meets these criteria and
demonstrate that sub-10ps resolution can be obtained for an existing device.


title: On spin 3 interacting with gravity

abstract:
  Recently Boulanger and Leclercq have constructed cubic four derivative
$3-3-2$ vertex for interaction of spin 3 and spin 2 particles. This vertex is
trivially invariant under the gauge transformations of spin 2 field, so it
seemed that it could be expressed in terms of (linearized) Riemann tensor. And
indeed in this paper we managed to reproduce this vertex in the form $R
\partial \Phi \partial \Phi$, where $R$ -- linearized Riemann tensor and $\Phi$
-- completely symmetric third rank tensor. Then we consider deformation of this
vertex to $(A)dS$ space and show that such deformation produce "standard"
gravitational interaction for spin 3 particles (in linear approximation) in
agreement with general construction of Fradkin and Vasiliev. Then we turn to
the massive case and show that the same higher derivative terms allows one to
extend gauge invariant description of massive spin 3 particle from constant
curvature spaces to arbitrary gravitational backgrounds satisfying $R_{\mu\nu}
= 0$.


title: Conformally Invariant "Massless" Spin-2 Field in de Sitter Universe

abstract:
  ''Massless'' spin-2 field equation in de Sitter space, which is invariant
under the conformal transformation, has been obtained. The frame work utilized
is the symmetric rank-2 tensor field of the conformal group. Our method is
based on the group theoretical approach and six-cone formalism, initially
introduced by Dirac. Dirac's six-cone is used to obtain conformally invariant
equations on de Sitter space. The solution of the physical sector of massless
spin-2 field (linear gravity) in de Sitter ambient space is written as a
product of a generalized polarization tensor and a massless minimally coupled
scalar field. Similar to the minimally coupled scalar field, for quantization
of this sector, the Krein space quantization is utilized. We have calculated
the physical part of the linear graviton two-point function. This two-point
function is de Sitter invariant and free of pathological large distance
behavior.


title:
Analytic perturbations and systematic bias in statistical modeling and
  inference

abstract:
  In this paper we provide a comprehensive study of statistical inference in
linear and allied models which exhibit some analytic perturbations in their
design and covariance matrices. We also indicate a few potential applications.
In the theory of perturbations of linear operators it has been known for a long
time that the so-called ``singular perturbations'' can have a big impact on
solutions of equations involving these operators even when their size is small.
It appears that so far the question of whether such undesirable phenomena can
also occur in statistical models and their solutions has not been formally
studied. The models considered in this article arise in the context of
nonlinear models where a single parameter accounts for the nonlinearity.


title: Pranab Kumar Sen: Life and works

abstract:
  In this article, we describe briefly the highlights and various
accomplishments in the personal as well as the academic life of Professor
Pranab Kumar Sen.


title:
Optically induced transport properties of freely suspended semiconductor
  submicron channels

abstract:
  We report on optically induced transport phenomena in freely suspended
channels containing a two-dimensional electron gas (2DEG). The submicron
devices are fabricated in AlGaAs/GaAs heterostructures by etching techniques.
The photoresponse of the devices can be understood in terms of the combination
of photogating and a photodoping effect. The hereby enhanced electronic
conductance exhibits a time constant in the range of one to ten milliseconds.


title: Smooth estimation of mean residual life under random censoring

abstract:
  We propose here a smooth estimator of the mean residual life function based
on randomly censored data. This is derived by smoothing the product-limit
estimator using the Chaubey-Sen technique (Chaubey and Sen (1998)). The
resulting estimator does not suffer from boundary bias as is the case with
standard kernel smoothing. The asymptotic properties of the estimator are
investigated. We establish strong uniform consistency and asymptotic normality.
This complements the work of Chaubey and Sen (1999) which considered a similar
estimation procedure in the case of complete data. It is seen that the
properties are similar, though technically more difficult to prove, to those in
the complete data case with appropriate modifications due to censoring.


title:
X-Ray Emission from Supernova Remnants Observed in the ASCA Galactic
  Plane Survey

abstract:
  X-ray images and spectra of 5 cataloged supernova remnants (SNRs), G12.0-0.1,
G346.6-0.2, G348.5+0.1, G348.7+0.3, and G355.6-0.0, observed in the ASCA
galactic plane survey are presented. The sizes of X-ray emission from
G12.0-0.1, G348.5+0.1, G348.7+0.3, and G355.6-0.0 are comparable to their radio
structures, while that of G346.6-0.2 is smaller than the radio structure. The
X-ray spectra of all of the SNRs were heavily absorbed by interstellar matter
with N_H>10^{22} cm^{-2}. The spectrum of G355.6-0.0 exhibited emission lines,
indicating that the X-ray emission has a thin thermal plasma origin, and was
well represented by two-temperature thin thermal emission model. On the other
hand, no clear emission line features were found in the spectra of the others
and the spectra could be represented by either a thin thermal emission model or
a power-law model.


title: Periodic relativity: deflection of light, acceleration, rotation curves

abstract:
  Vectorial analysis relating to derivation of deflection of light is
presented. Curvilinear acceleration is distinguished from the Newtonian polar
conic acceleration. The difference between the two is due to the curvature
term. Lorentz invariant expression for acceleration is derived. A physical
theory of rotation curves of galaxies based on second solution to Einstein's
field equation is presented. Theory is applied to Milky Way, M31, NGC3198 and
Solar system. Modified Kepler's third law yields correct orbital periods of
stars in a galaxy. Deviation factor in the line element of the theory happens
to be the ratio of the Newtonian gravitational acceleration to the measured
acceleration of the star in the galaxy. Therefore this deviation factor can
replace the MOND function.


title: The LSND puzzle in the light of MiniBooNE results

abstract:
  I give a brief overview over various attempts to reconcile the LSND evidence
for oscillations with all other global neutrino data, including the results
from MiniBooNE. I discuss the status of oscillation schemes with one or more
sterile neutrinos and comment on various exotic proposals.


title: Conformal Metrics

abstract:
  This paper surveys some selected topics in the theory of conformal metrics
and their connections to complex analysis, partial differential equations and
conformal differential geometry.


title: The Standard model Higgs as the inflaton

abstract:
  We describe how non-minimal coupling term between the Higgs boson and gravity
can lead to the chaotic inflation in the Standard Model without introduction of
any additional degrees of freedom. Produced cosmological perturbations are
predicted to be in accordance with observations. The tensor modes of
perturbations are practically vanishing in the model.


title: Complete Gluonic Phase in Two-Flavor Color Superconductivity

abstract:
  We study a typical complete gluonic phase (LGP) in two-flavor color
superconductivity (2SC) by calculating the essential cubic and quartic
interfering term between the gluonic condensates $<A^{(8)}_{z}>$ and
$<A^{(6)}_{z}>$ with a gauged NJL model. It is proven that the coefficient of
the cubic interfering term and the vacuum contributions of the cubic and
quartic interfering term are all equal to zeroes. The coefficients of the
quartic interfering term and the $<A^{(6)}_{z}>$'s quartic self-interaction
term at stationary points of LOFF phase are calculated. Comparisons among the
effective potentials of LGP, g2SC and LOFF phase indicate that LGP could be the
genuine ground state of 2SC for some reasonable parameters.


title:
The spatial distribution of galaxies of different spectral types in the
  massive intermediate-redshift cluster MACSJ0717.5+3745

abstract:
  We present the results of a wide-field spectroscopic analysis of the galaxy
population of the massive cluster MACSJ0717.5+3745 and the surrounding
filamentary structure (z=0.55), as part of our systematic study of the 12 most
distant clusters in the MACS sample. Of 1368 galaxies spectroscopically
observed in this field, 563 are identified as cluster members; of those, 203
are classified as emission-line galaxies, 260 as absorption-line galaxies, and
17 as E+A galaxies (defined by $\frac{H_{\delta}+H_{\gamma}}{2}>6$\AA and no
detection of [OII] and $H_{\beta}$ in emission). The variation of the fraction
of emission- and absorption-line galaxies as a function of local projected
galaxy density confirms the well-known morphology-density relation, and becomes
flat at projected galaxy densities less than $\sim 20Mpc^{-2}. Interestingly,
16 out of 17 E+A galaxies lie (in projection) within the ram-pressure stripping
radius around the cluster core, which we take to be direct evidence of
ram-pressure stripping being the primary mechanism that terminates
star-formation in the E+A population of galaxy clusters. This conclusion is
supported by the rarity of E+A galaxies in the filament which rules out galaxy
mergers as the dominant driver of evolution for E+A galaxies in clusters. In
addition, we find the 42 e(a) and 27 e(b) member galaxies, i.e., the
dusty-starburst and starburst galaxies respectively, to be spread out across
almost the entire study area. Their spatial distribution, which shows a strong
preference for the filament region, suggests that starbursts are triggered in
relatively low-density environments as galaxies are accreted from the field
population.


title:
Order restricted inference for comparing the cumulative incidence of a
  competing risk over several populations

abstract:
  There is a substantial literature on testing for the equality of the
cumulative incidence functions associated with one specific cause in a
competing risks setting across several populations against specific or all
alternatives. In this paper we propose an asymptotically distribution-free test
when the alternative is that the incidence functions are linearly ordered, but
not equal. The motivation stems from the fact that in many examples such a
linear ordering seems reasonable intuitively and is borne out generally from
empirical observations. These tests are more powerful when the ordering is
justified. We also provide estimators of the incidence functions under this
ordering constraint, derive their asymptotic properties for statistical
inference purposes, and show improvements over the unrestricted estimators when
the order restriction holds.


title: The relativity of hyperbolic space

abstract:
  The longitudinal Doppler shift is a measure of hyperbolic distance.
Transformations of uniform motion are determined by the Doppler shift, while
its square root transforms to a uniformly accelerated frame. A time-velocity
space metric is derived, by magnifying the Beltrami coordinates with the
geometric time, which is similar to the one obtained by Friedmann using
Einstein's equations in which the mass tensor describes a universe of dust at
zero pressure. No such assumption nor any approximation in which the
coordinates increase with time (i.e., constant velocities) need be made. The
hyperbolic velocities are related to the sides of a Lambert quadrilateral. In
the limit when the acute angle becomes an ideal point, the case of uniform
acceleration arises. The relations to Hubble's law, and to the exponential red
shift, are discussed.


title:
WIMP mass from direct, indirect dark matter detection experiments and
  colliders: A complementary and model-independent approach

abstract:
  We study the possibility of identifying dark matter properties from direct
(XENON100) and indirect (GLAST) detection experiments. In the same way, we
examine the perspectives given by the next generation of colliders (ILC). All
this analysis is done following a model-independent approach. We have shown
that the three detection techniques can act in a highly complementary way.
whereas direct detection experiments will probe efficiently light WIMPs, given
a positive detection (at the 10% level for $m_{\chi} \sim 50$ GeV), GLAST will
be able to confirm and even increase the precision in the case of a NFW
profile, for a WIMP-nucleon cross-section $\sigma_{\chi-p}<10^{-8}$ pb.
However, for heavier WIMP ($\sim 175$ GeV), the ILC will lead the
reconstruction of the mass.


title:
Statistical inference under order restrictions on both rows and columns
  of a matrix, with an application in toxicology

abstract:
  We present a general methodology for performing statistical inference on the
components of a real-valued matrix parameter for which rows and columns are
subject to order restrictions. The proposed estimation procedure is based on an
iterative algorithm developed by Dykstra and Robertson (1982) for simple order
restriction on rows and columns of a matrix. For any order restrictions on rows
and columns of a matrix, sufficient conditions are derived for the algorithm to
converge in a single application of row and column operations. The new
algorithm is applicable to a broad collection of order restrictions. In
practice, it is easy to design a study such that the sufficient conditions
derived in this paper are satisfied. For instance, the sufficient conditions
are satisfied in a balanced design. Using the estimation procedure developed in
this article, a bootstrap test for order restrictions on rows and columns of a
matrix is proposed. Computer simulations for ordinal data were performed to
compare the proposed test with some existing test procedures in terms of size
and power. The new methodology is illustrated by applying it to a set of
ordinal data obtained from a toxicological study.


title: Totally free arrangements of hyperplanes

abstract:
  A central arrangement $\A$ of hyperplanes in an $\ell$-dimensional vector
space $V$ is said to be {\it totally free} if a multiarrangement $(\A, m)$ is
free for any multiplicity $ m : \A\to \Z_{> 0}$. It has been known that $\A$ is
totally free whenever $\ell \le 2$. In this article, we will prove that there
does not exist any totally free arrangement other than the obvious ones, that
is, a product of one-dimensional arrangements and two-dimensional ones.


title:
Microstructure of precipitates and magnetic domain structure in an
  annealed Co38Ni33Al29 shape memory alloy

abstract:
  The microstructure of a CoNiAl FSMA was determined by conventional
transmission electron microscopy, electron diffraction studies together with
advanced microscopy techniques and in-situ Lorentz microscopy. 10 to 60 nm
sized rod-like precipitates of hcp $\epsilon$-Co were confirmed to be present
by HRTEM. The orientation relationship between the precipitates and B2 matrix
is described by the Burgers orientation relationship. The crystal structure of
the martensite obtained after cooling is tetragonal L10 with a (1-11) twinning
plane. The magnetic domain structure was determined during an in-situ cooling
experiment using the Fresnel mode of Lorentz microscopy. While transformation
proceeds from B2 austenite to L10 martensite, new domains are nucleated leading
to a decrease in domain width, with the magnetization lying predominantly along
a single direction. It was possible to completely describe the relationship
between magnetic domains and crystallographic directions in the austenite phase
though complications existed for the martensite phase.


title:
Energy dependence of fluctuations in central Pb+Pb collisions from NA49
  at the CERN SPS

abstract:
  The latest NA49 results on fluctuations of multiplicity and average
transverse-momentum analyzed on an event-by-event basis are presented for
central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV).
The scaled variance of the multiplicity distribution decreases with collision
energy whereas the $\Phi_{p_{T}}$ measure of $<p_T>$ fluctuations is small and
independent of collision energy. Thus in central Pb+Pb collisions these
fluctuations do not show an indication of the critical point of strongly
interacting matter.


title:
On the structure of a family of probability generating functions induced
  by shock models

abstract:
  We explore conditions for a class of functions defined via an integral
representation to be a probability generating function of some positive integer
valued random variable. Interest in and research on this question is motivated
by an apparently surprising connection between a family of classic shock models
due to Esary et. al. (1973) and the negatively aging nonparametric notion of
``strongly decreasing failure rate'' (SDFR) introduced by Bhattacharjee (2005).
A counterexample shows that there exist probability generating functions with
our integral representation which are not discrete SDFR, but when used as shock
resistance probabilities can give rise to a SDFR survival distribution in
continuous time.


title: Small-x Physics and the Detection of UHE Neutrinos

abstract:
  We evaluate both the tau lepton energy loss produced by photonuclear
interactions and the neutrino charged current cross section at ultra-high
energies, both relevant to neutrino bounds with Earth-skimming tau neutrinos.


title: Production of Secondaries in pp Collisions at RHIC Energies

abstract:
  The midrapidity inclusive densities of different secondaries are calculated
in the framework of the Quark-Gluon String Model. The transfer of baryon number
in rapidity space due to the gluon string junction propagation leads to a
significant effect on the net baryon production. The numerical results are in
reasonable agreement with RHIC experimental data.


title: Does avian magnetoreception rely on both magnetite and maghemite?

abstract:
  Recently, a putative magnetoreceptor in the upper-beak skin of homing pigeons
was chemically characterized using X-ray flourescence and absorbtion studies
[Fleissner et al., 2007. A novel concept of Fe-mineral based magnetoreception:
histological and physiochemical data from the upper beak of homing pigeons.
Naturwissenschaften 94 (8), 631-642]. In this short communication we point out
that the novel concept propagated is based on conclusions that are not
supported by data and, in fact, stand in contradiction to previously published
crystallographic and magnetic data.


title: Density dependence of isospin observables in spinodal decomposition

abstract:
  Isotopic fluctuations in fragment formation are investigated in a
quasi-analytical description of the spinodal decomposition scenario. By
exploiting the fluctuation-dissipation relations the covariance matrix of
density fluctuations is derived as a function of the wave vector for nuclear
matter at given values of density, charge asymmetry, temperature, and of the
time that the system spends in the instability region. Then density
fluctuations in ordinary space are implemented with a Fourier transform
performed in a finite cubic lattice. Inside this box, domains with different
density coexist, from which clusters of nucleons eventually emerge. Within our
approach, the isotopic distributions are determined by the N/Z ratio of the
leading unstable isoscalarlike mode and by isovectorlike fluctuations present
in the matter undergoing the spinodal decomposition. Hence the average value of
the N/Z ratio of clusters and the width of the relative distribution reflect
the properties of the symmetry energy. Generating a large number of events,
these calculations allow a careful investigation of the cluster isotopic
content as a function of the cluster density. A uniform decrease of the average
charge asymmetry and of the width of the isotopic distributions with increasing
density is observed. Finally we remark that the results essentially refer to
the early break--up of the system.


title:
Multi-dimensional modelling of X-ray spectra for AGN accretion-disk
  outflows

abstract:
  We use a multi-dimensional Monte Carlo code to compute X-ray spectra for a
variety of active galactic nucleus (AGN) disk-wind outflow geometries. We focus
on the formation of blue-shifted absorption features in the Fe K band and show
that line features similar to those which have been reported in observations
are often produced for lines-of-sight through disk-wind geometries. We also
discuss the formation of other spectral features in highly ionized outflows. In
particular we show that, for sufficiently high wind densities, moderately
strong Fe K emission lines can form and that electron scattering in the flow
may cause these lines to develop extended red wings. We illustrate the
potential relevance of such models to the interpretation of real X-ray data by
comparison with observations of a well-known AGN, Mrk 766.


title:
On stability, superstability and strong superstability of classical
  systems of Statistical Mechanics

abstract:
  A detailed analysis of conditions on 2-body interaction potential, which
ensure stability, superstability or strong superstability of statistical
systems is given. There has been given the connection between conditions of
superstability (strong superstability) and the problem of minimization of Riesz
energy in the bounded volumes


title:
Dissipative or just Nonextensive hydrodynamics? -
  Nonextensive/Dissipative correspondence -

abstract:
  We argue that there is correspondence between the perfect nonextensive
hydrodynamics and the usual dissipative hydrodynamics, which we call
nonextensive/dissipative correspondence (NexDC). It leads to simple expression
for dissipative entropy current and allows for predictions for the ratio of
bulk and shear viscosities to entropy density, $\zeta/s$ and $\eta/s$.


title:
On a comparative study between dependence scales determined by linear
  and non-linear measures

abstract:
  In this manuscript we present a comparative study about the determination of
the relaxation (\textit{i.e.}, independence) time scales obtained from the
correlation function, the mutual information, and a criterion based on the
evaluation of a nonextensive generalisation of mutual entropy. Our results show
that, for systems with a small degree of complexity, standard mutual
information and the criterion based on its nonextensive generalisation provide
the same scale, whereas for systems with a higher complex dynamics the standard
mutual information presents a time scale consistently smaller.


title:
Cosmological evolution of interacting phantom (quintessence) model in
  Loop Quantum Gravity

abstract:
  The dynamics of interacting dark energy model in loop quantum cosmology (LQC)
is studied in this paper. The dark energy has a constant equation of state
$w_x$ and interacts with dark matter through a form $3cH(\rho_x+\rho_m)$. We
find for quintessence model ($w_x>-1$) the cosmological evolution in LQC is the
same as that in classical Einstein cosmology; whereas for phantom dark energy
($w_x<-1$), although there are the same critical points in LQC and classical
Einstein cosmology, loop quantum effect reduces significantly the parameter
spacetime ($c, w_x$) required by stability. If parameters $c$ and $w_x$ satisfy
the conditions that the critical points are existent and stable, the universe
will enter an era dominated by dark energy and dark matter with a constant
energy ratio between them, and accelerate forever; otherwise it will enter an
oscillatory regime. Comparing our results with the observations we find at
$1\sigma$ confidence level the universe will accelerate forever.


title: Adaptive approximate Bayesian computation

abstract:
  Sequential techniques can enhance the efficiency of the approximate Bayesian
computation algorithm, as in Sisson et al.'s (2007) partial rejection control
version. While this method is based upon the theoretical works of Del Moral et
al. (2006), the application to approximate Bayesian computation results in a
bias in the approximation to the posterior. An alternative version based on
genuine importance sampling arguments bypasses this difficulty, in connection
with the population Monte Carlo method of Cappe et al. (2004), and it includes
an automatic scaling of the forward kernel. When applied to a population
genetics example, it compares favourably with two other versions of the
approximate algorithm.


title:
Optically induced electrostriction modes in a nanoparticle of a
  uniformly charged electret

abstract:
  The electromagnetic response of a nanoparticle of an ion-doped polymeric
elastic insulator, commonly called as an electret, is considered in the
continuum model of a uniformly charged elastic sphere. The spectral formulae
for the frequency of optically induced spheroidal and torsional shear
oscillations driven by bulk force of elastic and dielectric stresses are
obtained in analytic form. Particular attention is given to relaxation
dielectric mode of the electrostriction response and its stability in the
lowest quadrupole mode. The practical usefulness of ultrafine particles of
electrets as a biolabels capable of accumulating likely-charged inclusions
uniformly dispersed over the spherical volume of an elastic matrix is briefly
discussed.


title:
A Bayesian test for excess zeros in a zero-inflated power series
  distribution

abstract:
  Power series distributions form a useful subclass of one-parameter discrete
exponential families suitable for modeling count data. A zero-inflated power
series distribution is a mixture of a power series distribution and a
degenerate distribution at zero, with a mixing probability $p$ for the
degenerate distribution. This distribution is useful for modeling count data
that may have extra zeros. One question is whether the mixture model can be
reduced to the power series portion, corresponding to $p=0$, or whether there
are so many zeros in the data that zero inflation relative to the pure power
series distribution must be included in the model i.e., $p\geq0$. The problem
is difficult partially because $p=0$ is a boundary point. Here, we present a
Bayesian test for this problem based on recognizing that the parameter space
can be expanded to allow $p$ to be negative. Negative values of $p$ are
inconsistent with the interpretation of $p$ as a mixing probability, however,
they index distributions that are physically and probabilistically meaningful.
We compare our Bayesian solution to two standard frequentist testing procedures
and find that using a posterior probability as a test statistic has slightly
higher power on the most important ranges of the sample size $n$ and parameter
values than the score test and likelihood ratio test in simulations. Our method
also performs well on three real data sets.


title:
Cosmic Evolution of Stellar Disk Truncations: From z~1 to the Local
  Universe

abstract:
  We have conducted the largest systematic search so far for stellar disk
truncations in disk-like galaxies at intermediate redshift (z<1.1), using the
Great Observatories Origins Deep Survey South (GOODS-S) data from the Hubble
Space Telescope - ACS. Focusing on Type II galaxies (i.e. downbending profiles)
we explore whether the position of the break in the rest-frame B-band radial
surface brightness profile (a direct estimator of the extent of the disk where
most of the massive star formation is taking place), evolves with time. The
number of galaxies under analysis (238 of a total of 505) is an order of
magnitude larger than in previous studies. For the first time, we probe the
evolution of the break radius for a given stellar mass (a parameter well suited
to address evolutionary studies). Our results suggest that, for a given stellar
mass, the radial position of the break has increased with cosmic time by a
factor 1.3+/-0.1 between z~1 and z~0. This is in agreement with a moderate
inside-out growth of the disk galaxies in the last ~8 Gyr. In the same period
of time, the surface brightness level in the rest-frame B-band at which the
break takes place has increased by 3.3+/-0.2 mag/arcsec^2 (a decrease in
brightness by a factor of 20.9+/-4.2). We have explored the distribution of the
scale lengths of the disks in the region inside the break, and how this
parameter relates to the break radius. We also present results of the
statistical analysis of profiles of artificial galaxies, to assess the
reliability of our results.


title:
Microscopic calculation of the decay of Jaffe-Wilczek tetraquarks, and
  the Z(4433)

abstract:
  Here the tetraquarks are studied a la Jaffe and Wilczek. The decay width is
fully computed with a microscopic quark model, using the resonating group
method.


title: Large N Field Theory and AdS Tachyons

abstract:
  In non-supersymmetric orbifolds of N =4 super Yang-Mills, conformal
invariance is broken by the logarithmic running of double-trace operators -- a
leading effect at large N. A tachyonic instability in AdS_5 has been proposed
as the bulk dual of double-trace running. In this paper we make this
correspondence more precise. By standard field theory methods, we show that the
double-trace beta function is quadratic in the coupling, to all orders in
planar perturbation theory. Tuning the double-trace coupling to its (complex)
fixed point, we find conformal dimensions of the form 2 + i b, as formally
expected for operators dual to bulk scalars that violate the stability bound.
We also show that conformal invariance is broken in perturbation theory if and
only if dynamical symmetry breaking occurs. Our analysis is applicable to a
general large N field theory with vanishing single-trace beta functions.


title: Search for the decay K_S->e+e-

abstract:
  We present results of a direct search for the decay K_S->e+e- with the KLOE
detector, obtained with a sample of e+e- -> phi -> K_S K_L events produced at
DAFNE, the Frascati phi-factory, for an integrated luminosity of 1.9 fb-1. The
Standard Model prediction for this decay is BR(K_S->e+e-) = 2 x 10^-14. The
search has been performed by tagging the K_S decays with simultaneous detection
of a K_L interaction in the calorimeter. Background rejection has been
optimized by using both kinematic cuts and particle identification. At the end
of the analysis chain we find BR(K_S->e+e-) < 9.3 x 10^-9 at 90% CL, which
improves by a factor of ~15 on the previous best result, obtained by CPLEAR
experiment.


title: A Coding of Real Null Four-Momenta into World-Sheet Co-ordinates

abstract:
  The results of minimizing the action for string-like systems on a
simply-connected world sheet are shown to encode the Cartesian components of
real null momentum four-vectors into co-ordinates on the world sheet. This
identification arises consistently from different approaches to the problem.


title:
Posterior consistency of Dirichlet mixtures of beta densities in
  estimating positive false discovery rates

abstract:
  In recent years, multiple hypothesis testing has come to the forefront of
statistical research, ostensibly in relation to applications in genomics and
some other emerging fields. The false discovery rate (FDR) and its variants
provide very important notions of errors in this context comparable to the role
of error probabilities in classical testing problems. Accurate estimation of
positive FDR (pFDR), a variant of the FDR, is essential in assessing and
controlling this measure. In a recent paper, the authors proposed a model-based
nonparametric Bayesian method of estimation of the pFDR function. In
particular, the density of p-values was modeled as a mixture of decreasing beta
densities and an appropriate Dirichlet process was considered as a prior on the
mixing measure. The resulting procedure was shown to work well in simulations.
In this paper, we provide some theoretical results in support of the beta
mixture model for the density of p-values, and show that, under appropriate
conditions, the resulting posterior is consistent as the number of hypotheses
grows to infinity.


title: On hereditarily indecomposable compacta and factorization of maps

abstract:
  We prove a general factorization theorem for maps with hereditarily
indecomposable fibers and apply it to reprove a theorem of Mackoviak on the
existence of universal hereditarily indecomposable continua.


title: Nuclear Black Hole Formation in Clumpy Galaxies at High Redshift

abstract:
  Massive stellar clumps in high redshift galaxies interact and migrate to the
center to form a bulge and exponential disk in <1 Gyr. Here we consider the
fate of intermediate mass black holes (BHs) that might form by massive-star
coalescence in the dense young clusters of these disk clumps. We find that the
BHs move inward with the clumps and reach the inner few hundred parsecs in only
a few orbit times. There they could merge into a supermassive BH by dynamical
friction. The ratio of BH mass to stellar mass in the disk clumps is
approximately preserved in the final ratio of BH to bulge mass. Because this
ratio for individual clusters has been estimated to be ~10^{-3}, the observed
BH-to-bulge mass ratio results. We also obtain a relation between BH mass and
bulge velocity dispersion that is compatible with observations of present-day
galaxies.


title: Analytical studies for non-perturbative QCD of jets at hadron colliders

abstract:
  Inspired by the success of analytical models for non-perturbative effects,
used to investigate event shape variables at LEP and HERA, we apply them to a
study of jets at hadron colliders such as the Tevatron and the LHC. We find
that simple analytical estimates are able to shed considerable light on issues
that could previously be tackled only through Monte-Carlo simulations, for
example the role of different non-perturbative effects in various jet
algorithms. In this context, we also provide testable numerical results for the
commonly studied inclusive-jet $p_t$ distribution, and we introduce new
observables that could be employed to verify our calculations.


title: Robust estimation in finite population sampling

abstract:
  The paper proposes some robust estimators of the finite population mean. Such
estimators are particularly suitable in the presence of some outlying
observations. Included as special cases of our general result are robust
versions of the ratio estimator and the Horvitz-Thompson estimator. The robust
estimators are derived on the basis of certain predictive influence functions.


title: Near-edge x-ray absorption fine structure investigation of graphene

abstract:
  We report the near-edge x-ray absorption fine structure (NEXAFS) spectrum of
a single layer of graphite (graphene) obtained by micromechanical cleavage of
Highly Ordered Pyrolytic Graphite (HOPG) on a SiO2 substrate. We utilized a
PhotoEmission Electron Microscope (PEEM) to separately study single- double-
and few-layers graphene (FLG) samples. In single-layer graphene we observe a
splitting of the pi* resonance and a clear signature of the predicted
interlayer state. The NEXAFS data illustrate the rapid evolution of the
electronic structure with the increased number of layers.


title:
Comparison of clustering properties of observed objects and dark matter
  halos on different mass and spatial scales

abstract:
  We investigate the large-scale distribution of galaxy clusters taken from
several X-ray catalogs. Different statistics of clustering like the conditional
correlation function (CCF) and the minimal spanning tree (MST) as well as void
statistics were used. Clusters show two distinct regimes of clustering: 1) on
scales of superclusters (~40/h Mpc) the CCF is represented by a power law; 2)
on larger scales a gradual transition to homogeneity (~100/h Mpc) is observed.
We also present the correlation analysis of the galaxy distribution taken from
DR6 SDSS main galaxy database. In case of galaxies the limiting scales of the
different clustering regimes are 1)10-15/h Mpc; 2) 40-50/h Mpc. The differences
in the characteristic scales and scaling exponents of the cluster and galaxy
distribution can be naturally explained within the theory of biased structure
formation. We compared the density contrasts of inhomogeneities in the cluster
and galaxy distributions in the SDSS region. The estimation of the relative
cluster-galaxy bias gives the value b = 5 +/- 2. The distribution of real
clusters is compared to that of simulated (model) clusters (the MareNostrum
Universe simulations). We selected a cluster sample from 500/h Mpc simulation
box with WMAP3 cosmological parameters and sigma_8 = 0.8. We found a general
agreement between the distribution of observed and simulated clusters. The
differences are mainly due to the presences of the Shapley supercluster in the
observed sample. On the basis of SDSS galaxy sample we study properties of the
power law behavior showed by the CCF on small scales. We show that this
phenomenon is quite complex, with significant scatter in scaling properties,
and characterized by a non-trivial dependence on galaxy properties and
environment.


title: BiPo prototype for SuperNEMO radiopurity measurements

abstract:
  The BiPo project is dedicated to the measurement of extremely low radioactive
contaminations of SuperNEMO beta-beta source foils (208Tl < 2 microBq/kg and
214Bi < 10 microBq/kg). A modular BiPo1 prototype with its 20 modules and its
shielding test facility is running in the Modane Underground Laboratory since
February, 2008. The goal of this prototype is to study the backgrounds and
particularly the surface contamination of plastic scintillators. After 2
months, a preliminary upper limit on the sensitivity of a 10 m2 BiPo detector
in 208Tl contamination of selenium source foils can be extrapolated to:
A(208Tl) < 7.5 microBq/kg (90 % C.L.).


title: The MSSM with decoupled scalars at the LHC

abstract:
  The discovery potential for the MSSM with heavy scalars at the LHC in the
case of light inos is examined. We discuss the phenomenology of the model and
the observables to determine the parameters. We show that for light gauginos,
the model parameters can be constrained with a precision of the order of 15%.


title: Charm and Tau Decays: Review of BaBar and Belle Results

abstract:
  A review of recent results concerning decays of charmed mesons, charmed
baryons and $\tau$ leptons for the Belle and BaBar Experiments is given. The
review was presented at the 43$^{rd}$ Rencontres de Moriond (QCD and High
Energy Interactions), LaThuile, March 8-15, 2008.


title: A note on the Voigt profile function

abstract:
  A Voigt profile function emerges in several physical investigations (e.g.
atmospheric radiative transfer, astrophysical spectroscopy, plasma waves and
acoustics) and it turns out to be the convolution of the Gaussian and the
Lorentzian densities. Its relation with a number of special functions has been
widely derived in literature starting from its Fourier type integral
representation. The main aim of the present paper is to introduce the
Mellin-Barnes integral representation as a useful tool to obtain new analytical
results. Here, starting from the Mellin-Barnes integral representation, the
Voigt function is expressed in terms of the Fox H-function which includes
representations in terms of the Meijer G-function and previously well-known
representations with other special functions.


title: Rising Jet-Inflated Bubbles in Clusters of Galaxies

abstract:
  We conduct two-dimensional axisymmetric (referred to as 2.5D) hydrodynamical
numerical simulations of bubble evolution in clusters of galaxies. We inflate
bubbles using slow, massive jets with a wide opening angle, and follow their
evolution as they rise through the intra-cluster medium (ICM). We find that
these jet-inflated bubbles are quite stable, and can reach large distances in
the cluster while still maintaining their basic structure. The stability of the
jet-inflated bubble comes mainly from the dense shell that forms around it
during it's inflation stage, and from the outward momentum of the bubble and
the shell. On the contrary, bubbles that are inserted by hand onto the grid and
not inflated by a jet, i.e., an artificial bubble, lack these stabilizing
factors, therefore, they are rapidly destroyed. The stability of the
jet-inflated bubble removes the demand for stabilizing magnetic fields in the
bubble.


title:
Estimation of population-level summaries in general semiparametric
  repeated measures regression models

abstract:
  This paper considers a wide family of semiparametric repeated measures
regression models, in which the main interest is on estimating population-level
quantities such as mean, variance, probabilities etc. Examples of our framework
include generalized linear models for clustered/longitudinal data, among many
others. We derive plug-in kernel-based estimators of the population level
quantities and derive their asymptotic distribution. An example involving
estimation of the survival function of hemoglobin measures in the Kenya
hemoglobin study data is presented to demonstrate our methodology.


title: Fundamental groups of symmetric sextics. II

abstract:
  We study the moduli spaces and compute the fundamental groups of plane
sextics of torus type with the set of inner singularities $2\bold{A}_8$ or
$\bold{A}_{17}$. We also compute the fundamental groups of a number of other
sextics, both of and not of torus type. The groups found are simplest possible,
i.e., $\Bbb{Z}_2*\Bbb{Z}_3$ and $\Bbb{Z}_6$, respectively.


title: Parametrization of the QCD coupling in the Evolution Equations

abstract:
  We examine the parametrization of the QCD coupling in the Evolution
Equations, including DGLAP. Our conclusion is that the well-known
parametrization, where the argument of the coupling is k^2_{\perp}/\beta or
just k^2_{\perp}, stands only if the lowest integration limit in the transverse
momentum space (the starting point mu^2 of the Q^2 -evolution) obeys the
relation mu >> Lambda_{QCD} \exp {(\pi/2)}, otherwise the coupling should be
replaced by the more complicated expression presented in Eq. (37).


title:
Two-particle kinematic distributions from new physics at an
  electron-positron collider with polarized beams

abstract:
  The kinematic distributions in two-particle inclusive processes at an e+e-
collider arising from standard-model s-channel exchange of a virtual gamma or Z
and the interference of the standard-model contribution with contributions from
physics beyond the standard model involving s-channel exchanges are derived
entirely in terms of the space-time signature of such new physics. Transverse
as well as longitudinal polarizations of the electron and positron beams are
taken into account. We show how these model-independent distributions can be
used to deduce some general properties of the nature of the interaction. We
then specialize to two specific two-particle final states, viz., ZH, where H is
one of the Higgs bosons in a model with an extended Higgs sector, and f fbar,
where f, fbar are a pair of conjugate charged fermions, wherein distributions
of two (of the possibly several) decay products are measured. We show how some
of the properties of the distributions have been realized in the analysis of
physics beyond the standard model in earlier work which made use of
two-particle angular distributions.


title:
Generalized inversion of the Hochschild coboundary operator and
  deformation quantization

abstract:
  Using a derivative decomposition of the Hochschild differential complex we
define a generalized inverse of the Hochschild coboundary operator. It can be
applied for systematic computations of star products on Poisson manifolds.