title: Constraints on modular inflation in supergravity and string theory

abstract:
  We perform a general algebraic analysis on the possibility of realising
slow-roll inflation in the moduli sector of string models. This problem turns
out to be very closely related to the characterisation of models admitting
metastable vacua with non-negative cosmological constant. In fact, we show that
the condition for the existence of viable inflationary trajectories is a
deformation of the condition for the existence of metastable de Sitter vacua.
This condition depends on the ratio between the scale of inflation and the
gravitino mass and becomes stronger as this parameter grows. After performing a
general study within arbitrary supergravity models, we analyse the implications
of our results in several examples. More concretely, in the case of heterotic
and orientifold string compactifications on a Calabi-Yau in the large volume
limit we show that there may exist fully viable models, allowing both for
inflation and stabilisation. Additionally, we show that subleading corrections
breaking the no-scale property shared by these models always allow for
slow-roll inflation but with an inflationary scale suppressed with respect to
the gravitino scale. A scale of inflation larger than the gravitino scale can
also be achieved under more restrictive circumstances and only for certain
types of compactifications.


title: Some Remarks on the Pade Unitarization of Low-Energy Amplitudes

abstract:
  We present a critical analysis of Pade-based methods for the unitarization of
low energy amplitudes. We show that the use of certain Pade Approximants to
describe the resonance region may lead to inaccurate determinations. In
particular, we find that in the Linear Sigma Model the unitarization of the low
energy amplitude through the inverse amplitude method produces essentially
incorrect results for the mass and width of the sigma. Alternative sequences of
Pades are studied and we find that the diagonal sequences (i.e., [N/N]) have
much better convergence properties.


title:
Spontaneous dissipation of elastic energy by self-localizing thermal
  runaway

abstract:
  Thermal runaway instability induced by material softening due to shear
heating represents a potential mechanism for mechanical failure of viscoelastic
solids. In this work we present a model based on a continuum formulation of a
viscoelastic material with Arrhenius dependence of viscosity on temperature,
and investigate the behavior of the thermal runaway phenomenon by analytical
and numerical methods. Approximate analytical descriptions of the problem
reveal that onset of thermal runaway instability is controlled by only two
dimensionless combinations of physical parameters. Numerical simulations of the
model independently verify these analytical results and allow a quantitative
examination of the complete time evolutions of the shear stress and the spatial
distributions of temperature and displacement during runaway instability. Thus
we find that thermal runaway processes may well develop under nonadiabatic
conditions. Moreover, nonadiabaticity of the unstable runaway mode leads to
continuous and extreme localization of the strain and temperature profiles in
space, demonstrating that the thermal runaway process can cause shear banding.
Examples of time evolutions of the spatial distribution of the shear
displacement between the interior of the shear band and the essentially
nondeforming material outside are presented. Finally, a simple relation between
evolution of shear stress, displacement, shear-band width and temperature rise
during runaway instability is given.


title: Low-degree modes

abstract:
  The quest of the knowledge of the structure and dynamics of the solar
interior has been possible thanks to the study of the resonant acoustic (p)
modes that are trapped in the solar interior.
  Since the solar rotation lifts the azimuthal degeneracy of the resonant
modes, their eigenfrequencies are split into their m-components; where l is the
angular degree, n the radial order, and, m the azimuthal order. This separation
--usually called rotational splitting (or just splitting)-- depends on the
rotation rate in the region sampled by the mode. In the same way, the precise
frequency of a mode depends on the physical properties of the cavity where the
mode propagates. Using inversion techniques the rotation rate, the sound speed
or the density profile at different locations inside the Sun can be inferred
from a suitable lineal combination of the measured modes. But, during the last
year, a particular effort has been done in the extraction of physical
information directly from the combination of frequencies: the large and the
small frequency separations.


title:
Two-photon probe of the Jaynes-Cummings model and symmetry breaking in
  circuit QED

abstract:
  Superconducting qubits behave as artificial two-level atoms and are used to
investigate fundamental quantum phenomena. In this context, the study of
multi-photon excitations occupies a central role. Moreover, coupling
superconducting qubits to on-chip microwave resonators has given rise to the
field of circuit QED. In contrast to quantum-optical cavity QED, circuit QED
offers the tunability inherent to solid-state circuits. In this work, we report
on the observation of key signatures of a two-photon driven Jaynes-Cummings
model, which unveils the upconversion dynamics of a superconducting flux qubit
coupled to an on-chip resonator. Our experiment and theoretical analysis show
clear evidence for the coexistence of one- and two-photon driven level
anticrossings of the qubit-resonator system. This results from the symmetry
breaking of the system Hamiltonian, when parity becomes a not well-defined
property. Our study provides deep insight into the interplay of multiphoton
processes and symmetries in a qubit-resonator system.


title: Hochschild and ordinary cohomology rings of small categories

abstract:
  Let C be a small category and k a field. There are two interesting
mathematical subjects: the category algebra kC and the classifying space
|C|=BC. We study the ring homomorphism HH*(kC) --> H*(|C|,k) and prove it is
split surjective. This generalizes the well-known results for groups and
posets. Based on this result, we construct a seven-dimensional category algebra
whose Hochschild cohomology ring modulo nilpotents is not finitely generated,
against a conjecture of Snashall and Solberg.


title: Electroweak Precision Data and the Lee-Wick Standard Model

abstract:
  We investigate the electroweak precision constraints on the recently proposed
Lee-Wick Standard Model at tree level. We analyze low energy, Z-pole (LEP1/SLC)
and LEP2 data separately. We derive the exact tree level low energy and Z-pole
effective Lagrangians from both the auxiliary field and higher derivative
formulation of the theory. For the LEP2 data we use the fact that the Lee-Wick
Standard Model belongs to the so-called 'universal class' which can be
described by seven oblique parameters at leading order in m_W^2/M_{1,2}^2. At
tree level we find that the only non-zero oblique parameters are Y =
-m_W^2/M_1^2 and W = -m_W^2/M_2^2, where the negative sign is due to the
presence of the negative norm states. The Lee-Wick operators do not violate the
SU(2)_L or custodial symmetry at tree level implying S=0 and T=0 respectively.
Our results differ substantially from a prior analysis in this respect. We show
a plot including all three constraints. The LEP1/SLC constraints are slightly
stronger than LEP2 and much stronger than the low energy ones. The LEP1/SLC
results exclude gauge boson masses of M_1 ~ M_2 ~ 3 TeV at the 99% confidence
level. Somewhat lower masses are possible when one of the masses assumes a
large value. Loop corrections to the electroweak observables are suppressed by
the standard ~1/(4 \pi)^2 factor and are therefore not expected to change the
constraints on M_1 and M_2. This assertion is most transparent from the higher
derivative formulation of the theory.


title: A potential new method for determining the temperature of cool stars

abstract:
  We present high resolution (R = 90,000) mid-infrared spectra of M dwarfs. The
mid infrared region of the spectra of cool low mass stars contain pure
rotational water vapour transitions that may provide us with a new methodology
in the determination of the effective temperatures for low mass stars. We
identify and assign water transitions in these spectra and determine how
sensitive each pure rotational water transition is to small (25 K) changes in
effective temperature. We find that, of the 36 confirmed and assigned pure
rotational water transitions, at least 10 should be sensitive enough to be used
as temperature indicators.


title: Search for Blue Compact Dwarf Galaxies During Quiescence

abstract:
  Blue Compact Dwarf (BCD) galaxies are metal poor systems going through a
major starburst that cannot last for long. We have identified galaxies which
may be BCDs during quiescence (QBCD), i.e., before the characteristic starburst
sets in or when it has faded away. These QBCD galaxies are assumed to be like
the BCD host galaxies. The SDSS/DR6 database provides ~21500 QBCD candidates.
We also select from SDSS/DR6 a complete sample of BCD galaxies to serve as
reference. The properties of these two galaxy sets have been computed and
compared. The QBCD candidates are thirty times more abundant than the BCDs,
with their luminosity functions being very similar except for the scaling
factor, and the expected luminosity dimming associated with the end of the
starburst. QBCDs are redder than BCDs, and they have larger HII region based
oxygen abundance. QBCDs also have lower surface brightness. The BCD candidates
turn out to be the QBCD candidates with the largest specific star formation
rate (actually, with the largest H_alpha equivalent width). One out of each
three dwarf galaxies in the local universe may be a QBCD. The properties of the
selected BCDs and QBCDs are consistent with a single sequence in galactic
evolution, with the quiescent phase lasting thirty times longer than the
starburst phase. The resulting time-averaged star formation rate is low enough
to allow this cadence of BCD -- QBCD phases during the Hubble time.


title:
Electronic structure of Ga$_{1-x}$Cr$_{x}$N and Si-doping effects
  studied by photoemission and X-ray absorption spectroscopy

abstract:
  The electronic structure of the magnetic semiconductor Ga$_{1-x}$Cr$_{x}$N
and the effect of Si doping on it have been investigated by photoemission and
soft x-ray absorption spectroscopy. We have confirmed that Cr in GaN is
predominantly trivalent substituting for Ga, and that Cr 3$d$ states appear
within the band gap of GaN just above the N 2$p$-derived valence-band maximum.
As a result of Si doping, downward shifts of the core levels (except for Cr
2$p$) and the formation of new states near the Fermi level were observed, which
we attribute to the upward chemical potential shift and the formation of a
small amount of Cr$^{2+}$ species caused by the electron doping. Possibility of
Cr-rich cluster growth by Si doping are discussed based on the spectroscopic
and magnetization data.


title: Collective neutrino oscillations in non-spherical geometry

abstract:
  The rich phenomenology of collective neutrino oscillations has been studied
only in one-dimensional or spherically symmetric systems. Motivated by the
non-spherical example of coalescing neutron stars, presumably the central
engines of short gamma-ray bursts, we use the Liouville equation to formulate
the problem for general source geometries. Assuming the neutrino ensemble
displays self-maintained coherence, the problem once more becomes effectively
one-dimensional along the streamlines of the overall neutrino flux. This
approach for the first time provides a formal definition of the ``single-angle
approximation'' frequently used for supernova neutrinos and allows for a
natural generalization to non-spherical geometries. We study the explicit
example of a disk-shaped source as a proxy for coalescing neutron stars.


title: Neutron stars within the SU(2) parity doublet model

abstract:
  The equation of state of beta-stable and charge neutral nucleonic matter is
computed within the SU(2) parity doublet model in mean field and in the
relativistic Hartree approximation. The mass of the chiral partner of the
nucleon is assumed to be 1200 MeV. The transition to the chiral restored phase
turns out to be a smooth crossover in all the cases considered, taking place at
a baryon density of just $2\rho_0$. The mass-radius relations of compact stars
are calculated to constrain the model parameters from the maximum mass limit of
neutron stars. It is demonstrated that chiral symmetry starts to be restored,
which in this model implies the appearance of the chiral partners of the
nucleons, in the center of neutron stars. However, the analysis of the decay
width of the assumed chiral partner of the nucleon poses limits on the validity
of the present version of the model to describe vacuum properties.


title:
A new approach to analyzing solar coronal spectra and updated
  collisional ionization equilibrium calculations. II. Additional ionization
  rate coefficients

abstract:
  We have reanalyzed SUMER observations of a parcel of coronal gas using new
collisional ionization equilibrium (CIE) calculations. These improved CIE
fractional abundances were calculated using state-of-the-art electron-ion
recombination data for K-shell, L-shell, Na-like, and Mg-like ions of all
elements from H through Zn and, additionally, Al- through Ar-like ions of Fe.
They also incorporate the latest recommended electron impact ionization data
for all ions of H through Zn. Improved CIE calculations based on these
recombination and ionization data are presented here. We have also developed a
new systematic method for determining the average emission measure ($EM$) and
electron temperature ($T_e$) of an isothermal plasma. With our new CIE data and
our new approach for determining average $EM$ and $T_e$, we have reanalyzed
SUMER observations of the solar corona. We have compared our results with those
of previous studies and found some significant differences for the derived $EM$
and $T_e$. We have also calculated the enhancement of coronal elemental
abundances compared to their photospheric abundances, using the SUMER
observations themselves to determine the abundance enhancement factor for each
of the emitting elements. Our observationally derived first ionization
potential (FIP) factors are in reasonable agreement with the theoretical model
of Laming (2008).


title: Proving the existence of the $n$th root by induction

abstract:
  In this paper we prove by induction on $n$ that any positive real number has
$n$th root.


title:
Chromomagnetic Instability and Gluonic Phase in Dense Neutral Quark
  Matter

abstract:
  We discuss the chromomagnetic instability problem in the 2SC/g2SC phases and
explore the phase structure of the gluonic phase which is a candidate for the
ground state of dense neutral quark matter.


title: On a certain generalization of the Balog-Szemeredi-Gowers Theorem

abstract:
  In this note, we prove a certain hypergraph generalization of the
Balog-Szemeredi-Gowers Theorem. Our result shares some features in common with
a similar such generalizsation due to Sudakov, Szemeredi and Vu, though the
conclusion of our result is somewhat different.


title:
Non-equilibrium thermodynamic study of magnetization dynamics in the
  presence of spin-transfer torque

abstract:
  The dynamics of magnetization in the presence of spin-transfer torque was
studied. We derived the equation for the motion of magnetization in the
presence of a spin current by using the local equilibrium assumption in
non-equilibrium thermodynamics. We show that, in the resultant equation, the
ratio of the Gilbert damping constant, $\alpha$, and the coefficient, $\beta$,
of the current-induced torque, called non-adiabatic torque, depends on the
relaxation time of the fluctuating field $\tau_{c}$. The equality
$\alpha=\beta$ holds when $\tau_c$ is very short compared to the time scale of
magnetization dynamics. We apply our theory to current-induced magnetization
reversal in magnetic multilayers and show that the switching time is a
decreasing function of $\tau_{c}$.


title: An Introduction to Smooth Infinitesimal Analysis

abstract:
  An exposition of smooth infinitesimal analysis, which is a way to do calculus
with nilsquare infinitesimals, is given.


title:
Interior Cauchy-Schauder estimates for the heat flow in
  Carnot-Caratheodory spaces

abstract:
  The purpose of this paper is to establish some basic interior estimates of
Cauchy-Schauder type for the heat flow associated with a system of smooth
vector fields satisfying Hormander's finite rank condition


title: Impermeable Atomic Membranes from Graphene Sheets

abstract:
  We demonstrate that a monolayer graphene membrane is impermeable to standard
gases including helium. By applying a pressure difference across the membrane,
we measure both the elastic constants and the mass of a single layer of
graphene. This pressurized graphene membrane is the world's thinnest balloon
and provides a unique separation barrier between 2 distinct regions that is
only one atom thick.


title: MHV One-Loop Amplitudes in Yang-Mills from Generalised Unitarity

abstract:
  In this letter, we exploit generalised unitarity in order to calculate the
cut-constructible part of one-loop amplitudes in non-supersymmetric Yang-Mills
theory. In particular, we rederive the n-gluon MHV amplitudes for both the
adjacent and non-adjacent gluon helicity configurations from 3- and 4-particle
cuts alone.


title: Dynamical Regularization in Scalefree-trees of Coupled 2D Chaotic Maps

abstract:
  The dynamics of coupled 2D chaotic maps with time-delay on a scalefree-tree
is studied, with different types of the collective behaviors already been
reported for various values of coupling strength [1]. In this work we focus on
the dynamics' time-evolution at the coupling strength of the stability
threshold and examine the properties of the regularization process. The
time-scales involved in the appearance of the regular state and the periodic
state are determined. We find unexpected regularity in the the system's final
steady state: all the period values turn out to be integer multiples of one
among given numbers. Moreover, the period value distribution follows a
power-law with a slope of -2.24.


title: New results on kaon decays from NA48/2

abstract:
  Recent results from the NA48/2 experiment are presented. The $\pi\pi$
scattering lengths $a_0^0$ and $a_0^2$ have been extracted from the cusp in the
$M_{00}^2$ distribution of $K^\pm \to \pi^\pm \pi^0 \pi^0$ decays and from the
$K^\pm \to \pi^+ \pi^- e^\pm \nu$ phase shift $\delta$. Branching ratios and
form factors have been measured for {$K^\pm \to \pi^\pm \gamma \gamma$},
{$K^\pm \to \pi^\pm \gamma e^+ e^-$} and {$K^\pm \to \pi^\pm e^+ e^-$} decays
and are also summarized here.


title:
Molecular-orbital-free algorithm for excited states in time-dependent
  perturbation theory

abstract:
  A non-linear conjugate gradient optimization scheme is used to obtain
excitation energies within the Random Phase Approximation (RPA). The solutions
to the RPA eigenvalue equation are located through a variational
characterization using a modified Thouless functional, which is based upon an
asymmetric Rayleigh quotient, in an orthogonalized atomic orbital
representation. In this way, the computational bottleneck of calculating
molecular orbitals is avoided. The variational space is reduced to the
physically-relevant transitions by projections. The feasibility of an RPA
implementation scaling linearly with system size, N, is investigated by
monitoring convergence behavior with respect to the quality of initial guess
and sensitivity to noise under thresholding, both for well- and ill-conditioned
problems. The molecular- orbital-free algorithm is found to be robust and
computationally efficient providing a first step toward a large-scale, reduced
complexity calculation of time-dependent optical properties and linear
response. The algorithm is extensible to other forms of time-dependent
perturbation theory including, but not limited to, time-dependent Density
Functional theory.


title:
Spectro-astrometric imaging of molecular gas within protoplanetary disk
  gaps

abstract:
  We present velocity-resolved spectro-astrometric imaging of the 4.7 $\mu$m
rovibrational lines of CO gas in protoplanetary disks using the CRIRES high
resolution infrared spectrometer on the Very Large Telescope (VLT). The method
as applied to three disks with known dust gaps or inner holes out to 4-45 AU
(SR 21, HD 135344B and TW Hya) achieves an unprecedented spatial resolution of
$0.1-0.5$ AU. While one possible gap formation mechanism is dynamical clearing
by giant planets, other equally good explanations (stellar companions, grain
growth, photo-evaporation) exist. One way of distinguishing between different
scenarios is the presence and distribution of gas inside the dust gaps.
Keplerian disk models are fit to the spectro-astrometric position-velocity
curves to derive geometrical parameters of the molecular gas. We determine the
position angles and inclinations of the inner disks with accuracies as good as
1-2\degr, as well as the radial extent of the gas emission. Molecular gas is
detected well inside the dust gaps in all three disks. The gas emission extends
to within a radius of 0.5 AU for HD 135344B and to 0.1 AU for TW Hya,
supporting partial clearing by a $< 1-10 M_{\rm Jup}$ planetary body as the
cause of the observed dust gaps, or removal of the dust by extensive grain
coagulation and planetesimal formation. The molecular gas emission in SR 21
appears to be truncated within $\sim 7 $AU, which may be caused by complete
dynamical clearing by a more massive companion. We find a smaller inclination
angle of the inner disk of TW Hya than that determined for the outer disk,
suggestive of a disk warp. We also detect significant azimuthal asymmetries in
the SR 21 and HD 135344B inner disks.


title: Exploring the order parameter symmetry of p-wave Fermi condensates

abstract:
  We discuss the time-of-flight expansion of dilute p-wave Fermi condensates on
the BEC side of Feshbach resonances, as a way to extract information about the
order parameter symmetry for superfluidity. We show that the cloud profile is
in general sensitive to the interaction strength between fermions, the
magnitude and direction of external magnetic fields, and to the angular
momentum projection of the order parameter. In particular, due to the
anisotropic nature of p-wave interactions we show that the time-of-flight
expansion of a p-wave superfluid is anisotropic even if the superfluid is
confined to a completely isotropic trap, unlike the case of Bose or s-wave
Fermi condensates, which under the same circumstances expand isotropically.
Furthermore, we demonstrate that expanding p-wave superfluids released from
axially symmetric traps experience anisotropy inversions, where the aspect
ratio between the axial and radial directions change during expansion, while
the axial symmetry can also be lost reflecting the spatial anisotropy of the
underlying interaction.


title:
X and Y waves in the spatiotemporal Kerr dynamics of a self-guided light
  beam

abstract:
  The nonlinear stage of development of the spatiotemporal instability of the
monochromatic Townes beam in a medium with self-focusing nonlinearity and
normal dispersion is studied by analytical and numerical means. Small
perturbations to the self-guided light beam are found to grow into two giant,
splitting Y pulses featuring shock fronts on opposite sides. Each shocking
pulse amplifies a co-propagating X wave, or dispersion- and diffraction-free
linear wave mode of the medium, with super-broad spectrum.


title:
Determination of phase noise spectra in optoelectronic microwave
  oscillators: a Langevin approach

abstract:
  We introduce a stochastic model for the determination of phase noise in
optoelectronic oscillators. After a short overview of the main results for the
phase diffusion approach in autonomous oscillators, an extension is proposed
for the case of optoelectronic oscillators where the microwave is a limit-cycle
originated from a bifurcation induced by nonlinearity and time-delay. This
Langevin approach based on stochastic calculus is also successfully confronted
with experimental measurements.


title:
Generalised Chern-Simons actions for 3d gravity and kappa-Poincare
  symmetry

abstract:
  We consider Chern-Simons theories for the Poincare, de Sitter and anti-de
Sitter groups in three dimensions which generalise the Chern-Simons formulation
of 3d gravity. We determine conditions under which kappa-Poincare symmetry and
its de Sitter and anti-de Sitter analogues can be associated to these theories
as quantised symmetries. Assuming the usual form of those symmetries, with a
timelike vector as deformation parameter, we find that such an association is
possible only in the de Sitter case, and that the associated Chern-Simons
action is not the gravitational one. Although the resulting theory and 3d
gravity have the same equations of motion for the gauge field, they are not
equivalent, even classically, since they differ in their symplectic structure
and the coupling to matter. We deduce that kappa-Poincare symmetry is not
associated to either classical or quantum gravity in three dimensions. Starting
from the (non-gravitational) Chern-Simons action we explain how to construct a
multi-particle model which is invariant under the classical analogue of
kappa-de Sitter symmetry, and carry out the first steps in that construction.


title: First results from the ALHAMBRA-Survey

abstract:
  We present the first results from the ALHAMBRA survey. ALHAMBRA will cover a
relatively wide area (4 square degrees) using a purposely-designed set of 20
medium-band filters, down to an homogeneous magnitude limit AB~25 in most of
them, adding also deep near-infrared imaging in JHK. To this aim we are using
the Calar Alto 3.5m telescope. A small area of the ALHAMBRA survey has already
been observed through our complete filter set, and this allows for the first
time to check all the steps of the survey, including the pipelines that have
been designed for the project, the fulfilment of the data quality expectations,
the calibration procedures, and the photometric redshift machinery for which
ALHAMBRA has been optimised. We present here the basic results regarding the
properties of the galaxy sample selected in a 15x15 square arcmin area of the
ALHAMBRA-8 field, which includes approximately 10000 galaxies with precise
photometric redshift measurements. In a first estimate, approximately 500 of
them must be galaxies with z>2.


title: Characterizing indecomposable plane continua from their complements

abstract:
  We show that a plane continuum X is indecomposable iff X has a sequence (U_n)
of not necessarily distinct complementary domains satisfying what we call the
double-pass condition: If one draws an open arc A_n in each U_n whose ends
limit into the boundary of U_n, one can choose components of U_n minus A_n
whose boundaries intersected with the continuum (which we call shadows)
converge to the continuum.


title: Euclidean Supersymmetry, Twisting and Topological Sigma Models

abstract:
  We discuss two dimensional N-extended supersymmetry in Euclidean signature
and its R-symmetry. For N=2, the R-symmetry is SO(2)\times SO(1,1), so that
only an A-twist is possible. To formulate a B-twist, or to construct Euclidean
N=2 models with H-flux so that the target geometry is generalised Kahler, it is
necessary to work with a complexification of the sigma models. These issues are
related to the obstructions to the existence of non-trivial twisted chiral
superfields in Euclidean superspace.


title: Spectral centrality measures in complex networks

abstract:
  Complex networks are characterized by heterogeneous distributions of the
degree of nodes, which produce a large diversification of the roles of the
nodes within the network. Several centrality measures have been introduced to
rank nodes based on their topological importance within a graph. Here we review
and compare centrality measures based on spectral properties of graph matrices.
We shall focus on PageRank, eigenvector centrality and the hub/authority scores
of HITS. We derive simple relations between the measures and the (in)degree of
the nodes, in some limits. We also compare the rankings obtained with different
centrality measures.


title:
Any counterexample to Makienko's conjecture is an indecomposable
  continuum

abstract:
  Makienko's conjecture, a proposed addition to Sullivan's dictionary, can be
stated as follows: The Julia set of a rational function R has buried points if
and only if no component of the Fatou set is completely invariant under the
second iterate of R. We prove Makienko's conjecture for rational functions with
Julia sets that are decomposable continua. This is a very broad collection of
Julia sets; it is not known if there exists a rational functions whose Julia
set is an indecomposable continuum.


title: Incommensurability and atomic structure of c(2x2)N/Cu(100)

abstract:
  We use a scanning tunneling microscope operating in a low temperature,
ultrahigh vacuum environment to study the atomic structure of single layer
films of Cu2N grown on Cu(100). The c(2x2) lattice of Cu2N is incommensurate,
with a lattice constant of 3.72 +/- 0.02 angstrom that is 3% larger than the
bare Cu(100) surface. This finding suggests that strain due to lattice mismatch
contributes to self assembly in this system. We find that the image contrast on
Cu2N islands depends on bias voltage, which reconciles several interpretations
in the literature. We assign features in these STM images to the Cu, N and
hollow sites in the Cu2N lattice with the aid of co-adsorbed CO molecules. This
atomic registry allows us to characterize four different defects on Cu2N, which
influence the sticking coefficient and electronic coupling of adsorbates.


title: Protecting, Enhancing and Reviving Entanglement

abstract:
  We propose a strategies not only to protect but also to enhance and revive
the entanglement in a double Jaynes-Cummings model. We show that such
surprising features arises when Zeno-like measurements are performed during the
dynamical process.


title: Random paths with bounded local time

abstract:
  We consider one-dimensional Brownian motion conditioned (in a suitable sense)
to have a local time at every point and at every moment bounded by some fixed
constant. Our main result shows that a phenomenon of entropic repulsion occurs:
that is, this process is ballistic and has an asymptotic velocity approximately
4.58... as high as required by the conditioning (the exact value of this
constant involves the first zero of a Bessel function). We also study the
random walk case and show that the process is asymptotically ballistic but with
an unknown speed.


title:
CP Violation in B_s Mixing in the SUSY SU(5) GUT with Right-handed
  Neutrinos

abstract:
  It is recently announced by the {\bf Ut}{\it fit} collaboration that the CP
phase of the $B_s$ mixing amplitude, $\phi_{B_s}$, deviates more than $3
\sigma$ from the standard-model prediction. In this paper we discuss how large
correction to $\phi_{B_s}$ is possible in the supersymmetric SU(5) ground
unified model (SUSY SU(5) GUT) with right-handed neutrinos. Here, we assume the
supergravity-like boundary condition for the SUSY-breaking terms. We found that
the 95% probability region derived by the {\bf Ut}{\it fit} collaboration is
marginal in this model.


title: Quenching along a gapless line: A different exponent for defect density

abstract:
  We use a new quenching scheme to study the dynamics of a one-dimensional
anisotropic $XY$ spin-1/2 chain in the presence of a transverse field which
alternates between the values $h+\de$ and $h-\de$ from site to site. In this
quenching scheme, the parameter denoting the anisotropy of interaction ($\ga$)
is linearly quenched from $-\infty$ to $ +\infty$ as $\ga = t/\tau$, keeping
the total strength of interaction $J$ fixed. The system traverses through a
gapless phase when $\ga$ is quenched along the critical surface $h^2 = \de^2 +
J^2$ in the parameter space spanned by $h$, $\de$ and $\ga$. By mapping to an
equivalent two-level Landau-Zener problem, we show that the defect density in
the final state scales as $1/\tau^{1/3}$, a behavior that has not been observed
in previous studies of quenching through a gapless phase. We also generalize
the model incorporating additional alternations in the anisotropy or in the
strength of the interaction, and derive an identical result under a similar
quenching. Based on the above results, we propose a general scaling of the
defect density with the quenching rate $\tau$ for quenching along a gapless
critical line.


title:
Transforming the Einstein static Universe into physically acceptable
  static fluid spheres II: A two - fold infinity of exact solutions

abstract:
  Following a solution generating technique introduced recently by one of us,
we transform the Einstein static Universe into a two - fold infinity class of
physically acceptable exact perfect fluid solutions of Einstein's equations.
Whereas the entire class of solutions can be considered as generalizations of
the familiar Tolman IV solution, no member of the class can be written
explicitly in isotropic coordinates. Further, except for a set of measure zero,
no member of the class can be written explicitly in curvature coordinates
either.


title: Electromagnetic energy flow lines as possible paths of photons

abstract:
  Motivated by recent experiments where interference patterns behind a grating
are obtained by accumulating single photon events, here we provide an
electromagnetic energy flow-line description to explain the emergence of such
patterns. We find and discuss an analogy between the equation describing these
energy flow lines and the equation of Bohmian trajectories used to describe the
motion of massive particles.


title:
Investigating ChaMPlane X-ray sources in the Galactic Bulge with
  Magellan LDSS2 spectra

abstract:
  We have carried out optical and X-ray spectral analyses on a sample of 136
candidate optical counterparts of X-ray sources found in five Galactic-bulge
fields included in our Chandra Multi-wavelength Plane Survey. We use a
combination of optical spectral fitting and quantile X-ray analysis to obtain
the hydrogen column density towards each object, and a three-dimensional dust
model of the Galaxy to estimate the most probable distance in each case. We
present the discovery of a population of stellar coronal emission sources,
likely consisting of pre-main sequence, young main sequence and main sequence
stars, as well as a component of active binaries of RS CVn or BY Dra type. We
identify one candidate quiescent low-mass X-ray binary with a sub-giant
companion; we note that this object may also be an RS CVn system. We report the
discovery of three new X-ray detected cataclysmic variables (CVs) in the
direction of the Galactic Center (at distances ~2kpc). This number is in excess
of predictions made with a simple CV model based on a local CV space density of
<~ 10^-5 pc^-3, and a scale height ~200pc. We discuss several possible reasons
for this observed excess.


title: Experimental Study of a Lorentz Actuated Orbit

abstract:
  This experimental study investigates a new technique to keep a satellite in
orbit utilizing electrodynamics. The technique consists of establishing a
charge on a satellite such that the body's motion through a planetary magnetic
field induces acceleration via the Lorentz force. In order to find the
relationship between capacitance and power required to balance incident plasma
current, various objects were tested in high vacuum, plasma, and Xenon gas to
determine their ability to hold charge. Radioactive material (Am-241) and
pyroelectric crystals were tested as a candidate power source for charging the
objects. Microscopic arcing was observed at voltages as low as -300 V. This
arcing caused solder to explode off of the object. Insulating the object
allowed the charge to remain on the object longer, while in the plasma, and
also eliminated the arcing. However, this insulation does not allow a net
charge to reside on the surface of the spacecraft.


title:
Existence and stability of noncharacteristic boundary-layers for the
  compressible Navier-Stokes and viscous MHD equations

abstract:
  For a general class of hyperbolic-parabolic systems including the
compressible Navier-Stokes and compressible MHD equations, we prove existence
and stability of noncharacteristic viscous boundary layers for a variety of
boundary conditions including classical Navier-Stokes boundary conditions. Our
first main result, using the abstract framework established by the authors in
the companion work \cite{GMWZ6}, is to show that existence and stability of
arbitrary amplitude exact boundary-layer solutions follow from a uniform
spectral stability condition on layer profiles that is expressible in terms of
an Evans function (uniform Evans stability). Whenever this condition holds we
give a rigorous description of the small viscosity limit as the solution of a
hyperbolic problem with "residual" boundary conditions. Our second is to show
that uniform Evans stability for small-amplitude layers is equivalent to Evans
stability of the limiting constant layer, which in turn can be checked by a
linear-algebraic computation. Finally, for a class of symmetric-dissipative
systems including the physical examples mentioned above, we carry out energy
estimates showing that constant (and thus small-amplitude) layers always
satisfy uniform Evans stability. This yields existence of small-amplitude
multi-dimensional boundary layers for the compressible Navier-Stokes and MHD
equations. For both equations these appear to be the first such results in the
compressible case.


title: Collider Physics at HERA

abstract:
  From 1992 to 2007, HERA, the first electron-proton collider, operated at cms
energies of about 320 GeV and allowed the investigation of deep-inelastic and
photoproduction processes at the highest energy scales accessed thus far. This
review is an introduction to, and a summary of, the main results obtained at
HERA during its operation.


title:
Top-Quark Mass Data and the Sum of Quasi-Degenerate Neutrino Masses (One
  small electroweak-bound e-parameter organizes elementary particle 3-flavor
  phenomenology)

abstract:
  The absolute neutrino masses and type of neutrino mass hierarchy are among
the main problems in neutrino physics. Top-quark mass is another topical
problem in particle physics. These problems extend the old puzzle of
electron-muon mass ratio close to the fine structure constant, which is still
not solved by known theory. Here I continue the search for a general flavor
pattern that may incorporate these problems. Relations between
neutrino/electron and electron/top-quark pole mass ratios are obtained from
supposition that realistic elementary particle dimensionless bare flavor
quantities are small deviated (measured by universal parameter e) from the
values of a stated flavor pattern (at e=0) and experimental data hints. With
the world average t-quark mass data the sum of QD-neutrino masses is estimated
(0.50 +- 0.003)eV in agreement with cosmological constraints and known
QD-neutrino mass estimations from experimental data on neutrino oscillation
mass-squared differences.


title:
Spatial and observational homogeneities of the galaxy distribution in
  standard cosmologies

abstract:
  This work discusses the possible empirical verification of the geometrical
concept of homogeneity of the standard relativistic cosmology considering its
various definitions of distance. We study the physical consequences of the
distinction between the usual concept of spatial homogeneity (SH), as defined
by the Cosmological Principle, and the concept of observational homogeneity
(OH), arguing that OH is in principle falsifiable by means of astronomical
observations, whereas verifying SH is only possible indirectly. Simulated
counts of cosmological sources are produced by means of a generalized
number-distance expression that can be specialized to produce either the counts
of the Einstein-de Sitter (EdS) cosmology, which has SH by construction, or
other types of counts, which do, or do not, have OH by construction.
Expressions for observational volumes and differential densities are derived
with the various cosmological distance definitions in the EdS model. Simulated
counts that have OH by construction do not always exhibit SH features. The
reverse situation is also true. Besides, simulated counts with no OH features
at low redshift start showing OH characteristics at high redshift. The comoving
distance seems to be the only distance definition where both SH and OH appear
simultaneously. The results show that observations indicating possible lack of
OH do not necessarily falsify the standard Friedmannian cosmology, meaning that
this cosmology will not necessarily always produce observable homogeneous
densities. The general conclusion is that the use of different cosmological
distances in the characterization of the galaxy distribution lead to
significant ambiguities in reaching conclusions about the behavior of the
large-scale galaxy distribution in the Universe.


title:
Two timescale analysis of extreme mass ratio inspirals in Kerr. I.
  Orbital Motion

abstract:
  Inspirals of stellar mass compact objects into massive black holes are an
important source for future gravitational wave detectors such as Advanced LIGO
and LISA. Detection of these sources and extracting information from the signal
relies on accurate theoretical models of the binary dynamics. We cast the
equations describing binary inspiral in the extreme mass ratio limit in terms
of action angle variables, and derive properties of general solutions using a
two-timescale expansion. This provides a rigorous derivation of the
prescription for computing the leading order orbital motion. As shown by Mino,
this leading order or adiabatic motion requires only knowledge of the
orbit-averaged, dissipative piece of the self force. The two timescale method
also gives a framework for calculating the post-adiabatic corrections. For
circular and for equatorial orbits, the leading order corrections are
suppressed by one power of the mass ratio, and give rise to phase errors of
order unity over a complete inspiral through the relativistic regime. These
post-1-adiabatic corrections are generated by the fluctuating piece of the
dissipative, first order self force, by the conservative piece of the first
order self force, and by the orbit-averaged, dissipative piece of the second
order self force. We also sketch a two-timescale expansion of the Einstein
equation, and deduce an analytic formula for the leading order, adiabatic
gravitational waveforms generated by an inspiral.


title: Upper critical field in noncentrosymmetric superconductors

abstract:
  We calculate the upper critical field in superconductors without inversion
symmetry at arbitrary temperatures, in the presence of scalar impurities. Both
orbital and spin (paramagnetic) mechanisms of pair breaking are considered. The
superconducting phase transition at nonzero field occurs into a helical vortex
state, in which the order parameter is modulated along the applied field (in a
cubic crystal). The helical state is stable with respect to disorder. However,
if the difference between the densities of states in the electron bands split
by spin-orbit coupling is neglected, then the order parameter modulation is
present only at low temperatures, and only if the system is sufficiently clean
and paramagnetically limited. This state resembles the
Larkin-Ovchinnikov-Fulde-Ferrell state in centrosymmetric superconductors.


title:
Tri de la table de faits et compression des index bitmaps avec
  alignement sur les mots

abstract:
  Bitmap indexes are frequently used to index multidimensional data. They rely
mostly on sequential input/output. Bitmaps can be compressed to reduce
input/output costs and minimize CPU usage. The most efficient compression
techniques are based on run-length encoding (RLE), such as Word-Aligned Hybrid
(WAH) compression. This type of compression accelerates logical operations
(AND, OR) over the bitmaps. However, run-length encoding is sensitive to the
order of the facts. Thus, we propose to sort the fact tables. We review
lexicographic, Gray-code, and block-wise sorting. We found that a lexicographic
sort improves compression--sometimes generating indexes twice as small--and
make indexes several times faster. While sorting takes time, this is partially
offset by the fact that it is faster to index a sorted table. Column order is
significant: it is generally preferable to put the columns having more distinct
values at the beginning. A block-wise sort is much less efficient than a full
sort. Moreover, we found that Gray-code sorting is not better than
lexicographic sorting when using word-aligned compression.


title: Natural Equivariant Dirac Operators

abstract:
  We introduce a new class of natural, explicitly defined, transversally
elliptic differential operators over manifolds with compact group actions.
Under certain assumptions, the symbols of these operators generate all the
possible values of the equivariant index. We also show that the components of
the representation-valued equivariant index coincide with those of an elliptic
operator constructed from the original data.


title:
HE 1327-2326, an unevolved star with [Fe/H]<-5.0. II. New 3D-1D
  corrected abundances from a VLT/UVES spectrum

abstract:
  We present a new abundance analysis of HE 1327-2326, the currently most
iron-poor star, based on observational data obtained with VLT/UVES. We correct
the 1D LTE abundances for 3D effects to provide an abundance pattern that
supersedes previous works, and should be used to observationally test current
models of the chemical yields of the first-generation SNe. Apart from
confirming the 1D LTE abundances found in previous studies before accounting
for 3D effects, we make use of a novel technique to apply the 3D-1D corrections
for CNO which are a function of excitation potential and line strength for the
molecular lines that comprise the observable CH, NH, and OH features. We find
that the fit to the NH band at 3360 A is greatly improved due to the
application of the 3D-1D corrections. This may indicate that 3D effects are
actually observable in this star. We also report the first detection of several
weak Ni lines. The cosmologically important element Li is still not detected;
the new Li upper limit is extremely low, A(Li)<0.62, and in stark contrast with
results not only from WMAP but also from other metal-poor stars. We also
discuss how the new corrected abundance pattern of HE 1327-2326 is being
reproduced by individual and integrated yields of SNe.


title: Baryons and Vector Dominance in Holographic Dual QCD

abstract:
  The infinite tower of vector mesons encoded in holographic dual QCD bring
drastic changes to the soliton structure of the nucleon. The nucleon is given
by a point-like instanton in 5D surrounded by a vector meson cloud with the
vector dominance restored by the infinite tower. I discuss the possible
relevance of this structure in hot and dense hadronic matter.


title:
A Numerical Renormalization Group Study of the Superconducting and Spin
  Density Wave Instabilities in MFeAsO$_{1-x}$F$_x$ Compounds

abstract:
  We apply the fermion renormalization group method, implemented numerically by
Honerkamp et.al., to a two-band model of FeAs-based materials. At half filling
we find the $(\pi,0)$ or $(0,\pi)$ spin density wave order and a sub-dominant
superconducting pairing tendency. Due to a topological reason, the spin density
wave gap has nodes on the fermi surfaces. Away from half filling we find an
unconventional s-wave and a sub-dominant $d_{x^2-y^2}$ pairing instability. The
former has $s$ symmetry around the hole fermi surface but exhibits
$s+d_{x^2-y^2}$ symmetry around the electron pockets where the 90 degree
rotation is broken. The pairing mechanism is inter-pocket pair hopping.
Interestingly, the same interaction also drives the antiferromagnetism.


title:
The End of Amnesia: A New Method for Measuring the Metallicity of Type
  Ia Supernova Progenitors Using Manganese Lines in Supernova Remnants

abstract:
  We propose a new method to measure the metallicity of Type Ia supernova
progenitors using Mn and Cr lines in the X-ray spectra of young supernova
remnants. We show that the Mn to Cr mass ratio in Type Ia supernova ejecta is
tightly correlated with the initial metallicity of the progenitor, as
determined by the neutron excess of the white dwarf material before
thermonuclear runaway. We use this correlation, together with the flux of the
Cr and Mn Kalpha X-ray lines in the Tycho supernova remnant recently detected
by Suzaku (Tamagawa et al. 2008) to derive a metallicity of log(Z) = -1.32
(+0.67,-0.33) for the progenitor of this supernova, which corresponds to
log(Z/Zsun)= 0.60 (+0.31,-0.60) according to the latest determination of the
solar metallicity by Asplund et al. (2005). The uncertainty in the measurement
is large, but metallicities much smaller than the solar value can be
confidently discarded. We discuss the implications of this result for future
research on Type Ia supernova progenitors.


title:
Criteria for Core-Collapse Supernova Explosions by the Neutrino
  Mechanism

abstract:
  We investigate the criteria for successful core-collapse supernova explosions
by the neutrino mechanism. We find that a
critical-luminosity/mass-accretion-rate condition distinguishes non-exploding
from exploding models in hydrodynamic one-dimensional (1D) and two-dimensional
(2D) simulations. We present 95 such simulations that parametrically explore
the dependence on neutrino luminosity, mass accretion rate, resolution, and
dimensionality. While radial oscillations mediate the transition between 1D
accretion (non-exploding) and exploding simulations, the non-radial standing
accretion shock instability characterizes 2D simulations. We find that it is
useful to compare the average dwell time of matter in the gain region with the
corresponding heating timescale, but that tracking the residence time
distribution function of tracer particles better describes the complex flows in
multi-dimensional simulations. Integral quantities such as the net heating
rate, heating efficiency, and mass in the gain region decrease with time in
non-exploding models, but for 2D exploding models, increase before, during, and
after explosion. At the onset of explosion in 2D, the heating efficiency is
$\sim$2% to $\sim$5% and the mass in the gain region is $\sim$0.005 M$_{\sun}$
to $\sim$0.01 M$_{\sun}$. Importantly, we find that the critical luminosity for
explosions in 2D is $\sim$70% of the critical luminosity required in 1D. This
result is not sensitive to resolution or whether the 2D computational domain is
a quadrant or the full 180$^{\circ}$. We suggest that the relaxation of the
explosion condition in going from 1D to 2D (and to, perhaps, 3D) is of a
general character and is not limited by the parametric nature of this study.


title: Connecting Galaxies, Halos, and Star Formation Rates Across Cosmic Time

abstract:
  A simple, observationally-motivated model is presented for understanding how
halo masses, galaxy stellar masses, and star formation rates are related, and
how these relations evolve with time. The relation between halo mass and galaxy
stellar mass is determined by matching the observed spatial abundance of
galaxies to the expected spatial abundance of halos at multiple epochs -- i.e.
more massive galaxies are assigned to more massive halos at each epoch. Halos
at different epochs are connected by halo mass accretion histories estimated
from N-body simulations. The halo--galaxy connection at fixed epochs in
conjunction with the connection between halos across time provides a connection
between observed galaxies across time. With approximations for the impact of
merging and accretion on the growth of galaxies, one can then directly infer
the star formation histories of galaxies as a function of stellar and halo
mass. This model is tuned to match both the observed evolution of the stellar
mass function and the normalization of the observed star formation rate --
stellar mass relation to z~1. The data demands, for example, that the star
formation rate density is dominated by galaxies with Mstar~10^{10.0-10.5} Msun
from 0<z<1, and that such galaxies over these epochs reside in halos with
M~10^{11.5-12.5} Msun. The star formation rate -- halo mass relation is
approximately Gaussian over the range 0<z<1 with a mildly evolving mean and
normalization. This model is then used to shed light on a number of issues,
including 1) a clarification of ``downsizing'', 2) the lack of a sharp
characteristic halo mass at which star formation is truncated, and 3) the
dominance of star formation over merging to the stellar build-up of galaxies
with Mstar<10^11 Msun at z<1.


title:
Halperin-Saslow modes as the origin of the low temperature anomaly in
  $NiGa_2S_4$

abstract:
  The absence of magnetic long range order in the triangular lattice spin-1
antiferromagnet $NiGa$_2$S$_4$ has prompted the search for a novel quantum
ground state. In particular, several experiments suggest the presence of a
linearly dispersing mode despite no long-range magnetic order. We show that the
anomalous low temperature properties of NiGa$_2$S$_4$ can naturally be
explained by the formulation developed by Halperin and Saslow where the
linearly dispersing Halperin-Saslow mode may exist in the background of frozen
spin moments and zero net magnetization. We provide highly non-trivial
consistency checks on the existing experimental data and suggest future
experiments that can further confirm the existence of the Halperin-Saslow mode.
Our results place strong constraints on any microscopic theory of this
material.


title: Optimal light storage in atomic vapor

abstract:
  We study procedures for the optimization of efficiency of light storage and
retrieval based on the dynamic form of electromagnetically induced transparency
(EIT) in warm Rb vapor. We present a detailed analysis of two recently
demonstrated optimization protocols: a time-reversal-based iteration procedure,
which finds the optimal input signal pulse shape for any given control field,
and a procedure based on the calculation of an optimal control field for any
given signal pulse shape. We verify that the two procedures are consistent with
each other, and that they both independently achieve the maximum memory
efficiency for any given optical depth. We observe good agreement with
theoretical predictions for moderate optical depths (<25), while at higher
optical depths the experimental efficiency falls below the theoretically
predicted values. We identify possible effects responsible for this reduction
in memory efficiency.


title:
Contrasting Behavior of the 5/2 and 7/3 Fractional Quantum Hall Effect
  in a Tilted Field

abstract:
  Using a tilted field geometry, the effect of an in-plane magnetic field on
the even denominator nu = 5/2 fractional quantum Hall state is studied. The
energy gap of the nu = 5/2 state is found to collapse linearly with the
in-plane magnetic field above ~0.5 T. In contrast, a strong enhancement of the
gap is observed for the nu = 7/3 state. The radically distinct tilted-field
behaviour between the two states is discussed in terms of Zeeman and
magneto-orbital coupling within the context of the proposed Moore-Read pfaffian
wavefunction for the 5/2 fractional quantum Hall effect.


title: Slices of motivic Landweber spectra

abstract:
  We show that the Conjecture of Voevodsky concerning slices of the algebraic
cobordism spectrum MGL implies a general statement about the slices of motivic
Landweber spectra. In particular it confirms the possible approach suggested by
Voevodsky for the computation of the slices of the homotopy algebraic K-theory
spectrum KGL via a Conner-Floyd isomorphism complementing Levine's
unconditional proof of these slices over perfect fields. A similar result, and
Voevodsky's conjecture over fields of char. 0, are also announced by
Hopkins-Morel.


title: Analytic Scattering Amplitudes for QCD

abstract:
  By analytically continuing QCD scattering amplitudes through specific
complexified momenta, one can study and learn about the nature and the
consequences of factorization and unitarity. In some cases, when coupled with
the largest time equation and gauge invariance requirement, this approach leads
to recursion relations, which greatly simplify the construction of multi-gluon
scattering amplitudes. The setting for this discussion is in the space-cone
gauge.


title: Coding for quantum channels with side information at the transmitter

abstract:
  We consider the problem of coding for quantum channels with side information
that is available ahead of time at the transmitter but not at the receiver. We
find a single-letter expression for the entanglement-assisted quantum capacity
of such channels which closely parallels Gel'fand and Pinsker's solution to the
classical version of the same problem. This theorem can also be used to find a
lower bound on the unassisted quantum capacity of these channels.


title:
Stimulated Raman process in a scattering medium in application to
  quantum memory scheme

abstract:
  We consider the coherent stimulated Raman process developing in an optically
dense disordered atomic medium, which can also incoherently scatter the light
over all outward directions. The Raman process is discussed in the context of a
quantum memory scheme and we point out the difference in its physical nature
from a similar but not identical protocol based on the effect of
electromagnetically induced transparency (EIT). We show that the Raman and EIT
memory schemes do not compete but complement one another and each of them has
certain advantages in the area of its applicability. We include in our
consideration an analysis of the transient processes associated with switching
the control pulse off or on and follow how they modify the probe pulse dynamics
on the retrieval stage of the memory protocol.


title: Solubility of Fermat equations

abstract:
  The arithmetic of ternary diagonal equation is considered for degree d >1,
with the outcome that the set of coefficients for which the equation admits a
non-zero integer solution is shown to have density zero.


title:
Pretzelosity distribution function h_1T^perp and the single spin
  asymmetry A_UT^sin(3phi-phi_S)

abstract:
  The leading twist transverse momentum dependent parton distribution function
h_1T^perp, which is sometimes called ``pretzelosity,'' is studied. We review
the theoretical properties of this function, and present bag model predictions.
We observe an interesting relation valid in a large class of relativistic
models: The difference between helicity and transversity distributions, which
is often said to be a 'measure of relativistic effects' in nucleon, is nothing
but the pretzelosity distribution. Pretzelosity is chirally odd and can be
accessed in combination with the Collins effect in semi-inclusive deep
inelastic scattering, where it gives rise to an azimuthal single spin asymmetry
proportional to sin(3phi-phi_S). We discuss the preliminary deuteron target
data from COMPASS, on that observable and make predictions for future
experiments on various targets at JLab, COMPASS and HERMES.


title:
BETHE-Hydro: An Arbitrary Lagrangian-Eulerian Multi-dimensional
  Hydrodynamics Code for Astrophysical Simulations

abstract:
  In this paper, we describe a new hydrodynamics code for 1D and 2D
astrophysical simulations, BETHE-hydro, that uses time-dependent, arbitrary,
unstructured grids. The core of the hydrodynamics algorithm is an arbitrary
Lagrangian-Eulerian (ALE) approach, in which the gradient and divergence
operators are made compatible using the support-operator method. We present 1D
and 2D gravity solvers that are finite differenced using the support-operator
technique, and the resulting system of linear equations are solved using the
tridiagonal method for 1D simulations and an iterative multigrid-preconditioned
conjugate-gradient method for 2D simulations. Rotational terms are included for
2D calculations using cylindrical coordinates. We document an incompatibility
between a subcell pressure algorithm to suppress hourglass motions and the
subcell remapping algorithm and present a modified subcell pressure scheme that
avoids this problem. Strengths of this code include a straightforward
structure, enabling simple inclusion of additional physics packages, the
ability to use a general equation of state, and most importantly, the ability
to solve self-gravitating hydrodynamic flows on time-dependent, arbitrary
grids. In what follows, we describe in detail the numerical techniques employed
and, with a large suite of tests, demonstrate that BETHE-hydro finds accurate
solutions with 2$^{nd}$-order convergence.


title: Mechanical Systems that are both Classical and Quantum

abstract:
  Quantum dynamics can be regarded as a generalization of classical
finite-state dynamics. This is a familiar viewpoint for workers in quantum
computation, which encompasses classical computation as a special case. Here
this viewpoint is extended to mechanics, where classical dynamics has
traditionally been viewed as a macroscopic approximation of quantum behavior,
not as a special case.
  When a classical dynamics is recast as a special case of quantum dynamics,
the quantum description can be interpreted classically. For example, sometimes
extra information is added to the classical state in order to construct the
quantum description. This extra information is then eliminated by representing
it in a superposition as if it were unknown information about a classical
statistical ensemble. This usage of superposition leads to the appearance of
Fermions in the quantum description of classical lattice-gas dynamics and turns
continuous-space descriptions of finite-state systems into illustrations of
classical sampling theory.
  A direct mapping of classical systems onto quantum systems also allows us to
determine the minimum possible energy scale for a classical dynamics, based on
a localized rate of state change. We use a partitioning description of dynamics
to define locality, and discuss the ideal energy of two model systems.


title:
Moments of Heavy Quark Current Correlators at Four-Loop Order in
  Perturbative QCD

abstract:
  We present the result for the first moment of the scalar and axial-vector
current correlator in third order of the strong coupling constant alpha_s and
give the details of a recent evaluation of the pseudo-scalar correlator. The
results can be used to reduce the theoretical uncertainty due to higher order
corrections for the determination of fundamental parameters of QCD in the
context of lattice calculations.


title: On what Ontology Is and not-Is

abstract:
  In this paper I study the connection between logic and metaphysics in Plato's
participation theory, from the structural properties of the latter. Although
Plato was the first ever to formulate the contradiction principle explicitly
(in the Phaedo), the logic underlying his system appears to be paraconsistent.
This confirms an earlier suggestion by G. Priest. Its technical characteristics
and the textual evidence supporting this interpretation are both studied in
detail.


title: Cold Nuclear Modifications at RHIC and LHC

abstract:
  We use recent nuclear parton distributions, among them the
Hirai--Kumano--Nagai (HKN) and Eskola--Paukkunen--Salgado (EPS08)
parameterizations, in our pQCD-improved parton model to calculate the nuclear
modification factor, R_{AA'}(p_T), at RHIC and at the LHC. At RHIC, the
deuteron-gold nuclear modification factor for pions, measured at p_T > 10 GeV/c
in central collisions, appears to deviate more from unity than the model
results. The slopes of the calculated R_{dAu}(p_T) are similar to the slopes of
the PHENIX pion and photon data. At LHC, without final-state effects we see a
small enhancement of R_{dPb}(p_T) in the transverse momentum range 10 GeV/c <
p_T < 100 GeV/c for most parameterizations. The inclusion of final-state energy
loss will reduce the R_{dPb}(p_T) values.


title: U(1) Mediation of Flux Supersymmetry Breaking

abstract:
  We study the mediation of supersymmetry breaking triggered by background
fluxes in Type II string compactifications with N=1 supersymmetry. The
mediation arises due to an U(1) vector multiplet coupling to both a hidden
supersymmetry breaking flux sector and a visible D-brane sector. The required
internal manifolds can be constructed by non-Kaehler resolutions of singular
Calabi-Yau manifolds. The effective action encoding the U(1) coupling is then
determined in terms of the global topological properties of the internal space.
We investigate suitable local geometries for the hidden and visible sector in
detail. This includes a systematic study of orientifold symmetries of del Pezzo
surfaces realized in compact geometries after geometric transition. We
construct compact examples admitting the key properties to realize flux
supersymmetry breaking and U(1) mediation. Their toric realization allows us to
analyze the geometry of curve classes and confirm the topological connection
between the hidden and visible sector.


title: Two standard methods for solving the Ito equation

abstract:
  In this paper we show some exact solutions for the Ito equation. These
solutions are obtained by two methods: the tanh method and the projective
Riccati equation method.


title: An $L_\infty$ algebra structure on polyvector fields

abstract:
  It is well-known that the Kontsevich formality [K97] for Hochschild cochains
of the polynomial algebra $A=S(V^*)$ fails if the vector space $V$ is
infinite-dimensional. In the present paper, we study the corresponding
obstructions. We construct an $L_\infty$ structure on polyvector fields on $V$
having the even degree Taylor components, with the degree 2 component given by
the Schouten-Nijenhuis bracket, but having as well higher non-vanishing Taylor
components. We prove that this $L_\infty$ algebra is quasi-isomorphic to the
corresponding Hochschild cochain complex. We prove that our $L_\infty$ algebra
is $L_\infty$ quasi-isomorphic to the Lie algebra of polyvector fields on $V$
with the Schouten-Nijenhuis bracket, if $V$ is finite-dimensional.


title: Challenges of Lattice Calculation of Scalar Mesons

abstract:
  I review a proposed pattern of the light scalar mesons with q\bar{q} mesons
and glueball above 1 GeV and tetraquark mesoniums below 1 GeV. Several
challenges and caveats of calculating these light scalar mesons with dynamical
fermions are discussed.


title: Universal scaling of forest fire propagation

abstract:
  In this paper we use a variant of the Watts-Strogatz small-world model to
predict wildfire behavior near the critical propagation/nonpropagation
threshold. We find that forest fire patterns are fractal and that critical
exponents are universal, which suggests that the propagation/nonpropagation
transition is a second-order transition. Universality tells us that the
characteristic critical behaviour of propagation in real (amorphous) forest
landscapes can be extracted from the simplest network model.


title:
Computational Representation of Linguistic Structures using
  Domain-Specific Languages

abstract:
  We describe a modular system for generating sentences from formal definitions
of underlying linguistic structures using domain-specific languages. The system
uses Java in general, Prolog for lexical entries and custom domain-specific
languages based on Functional Grammar and Functional Discourse Grammar
notation, implemented using the ANTLR parser generator. We show how linguistic
and technological parts can be brought together in a natural language
processing system and how domain-specific languages can be used as a tool for
consistent formal notation in linguistic description.


title: Testing Dark Matter with Neutrino Detectors

abstract:
  Neutrinos are the least detectable Standard Model particle. By making use of
this fact, we consider dark matter annihilations and decays in the galactic
halo and show how present and future neutrino detectors could be used to set
general limits on the dark matter annihilation cross section and on the dark
matter lifetime.


title: A model of dissociated cortical tissue

abstract:
  A powerful experimental approach for investigating computation in networks of
biological neurons is the use of cultured dissociated cortical cells grown into
networks on a multi-electrode array. Such preparations allow investigation of
network development, activity, plasticity, responses to stimuli, and the
effects of pharmacological agents. They also exhibit whole-culture pathological
bursting; understanding the mechanisms that underlie this could allow creation
of more useful cell cultures and possibly have medical applications.


title:
Impact of the Atmospheric Refraction on the Precise Astrometry with
  Adaptive Optics in Infrared

abstract:
  We study the impact of the atmospheric differential chromatic refraction on
the measurements and precision of relative astrometry. Specifically, we address
the problem of measuring the separations of close pairs of binary stars with
adaptive optics in the J and K bands. We investigate the influence of weather
conditions, zenithal distance, star's spectral type and observing wavelength on
the astrometric precision and determine the accuracy of these parameters that
is necessary to detect exoplanets with existing and planned large ground based
telescopes with adaptive optics facilities.
  The analytical formulae for simple monochromatic refraction and a full
approach, as well as moderately simplified procedure, are used to compute
refraction corrections under a variety of observing conditions. It is shown
that the atmospheric refraction must be taken into account in astrometric
studies but the full procedure is not neccessary in many cases. Requirements
for achieving a certain astrometric precision are specified.


title: On minimal extensions of rings

abstract:
  Given two rings $R \subseteq S$, $S$ is said to be a minimal ring extension
of $R$ if $R$ is a maximal subring of $S$. In this article, we study minimal
extensions of an arbitrary ring $R$, with particular focus on those possessing
nonzero ideals that intersect $R$ trivially. We will also classify the minimal
ring extensions of prime rings, generalizing results of Dobbs, Dobbs & Shapiro,
and Ferrand & Olivier on commutative minimal extensions.


title:
Enormous disc of cool gas surrounding the nearby powerful radio galaxy
  NGC 612 (PKS 0131-36)

abstract:
  We present the detection of an enormous disc of cool neutral hydrogen (HI)
gas surrounding the S0 galaxy NGC 612, which hosts one of the nearest powerful
radio sources (PKS 0131-36). Using the Australia Telescope Compact Array, we
detect M_HI = 1.8 x 10^9 M_sun of HI emission-line gas that is distributed in a
140 kpc wide disc-like structure along the optical disc and dust-lane of NGC
612. The bulk of the gas in the disc appears to be settled in regular rotation
with a total velocity range of 850 km/s, although asymmetries in this disc
indicate that perturbations are being exerted on part of the gas, possibly by a
number of nearby companions. The HI disc in NGC 612 suggests that the total
mass enclosed by the system is M_enc ~ 2.9 x 10^12 sin^-2(i) M_sun, implying
that this early-type galaxy contains a massive dark matter halo. We also
discuss an earlier study by Holt et al. that revealed the presence of a
prominent young stellar population at various locations throughout the disc of
NGC 612, indicating that this is a rare example of an extended radio source
that is hosted by a galaxy with a large-scale star-forming disc. In addition,
we map a faint HI bridge along a distance of 400 kpc in between NGC 612 and the
gas-rich (M_HI = 8.9 x 10^9 M_sun) barred galaxy NGC 619, indicating that
likely an interaction between both systems occurred. From the unusual amounts
of HI gas and young stars in this early-type galaxy, in combination with the
detection of a faint optical shell and the system's high infra-red luminosity,
we argue that either ongoing or past galaxy interactions or a major merger
event are a likely mechanism for the triggering of the radio source in NGC 612.
This paper is part of an ongoing study to map the large-scale neutral hydrogen
properties of nearby radio galaxies. --abridged--


title: Proper holomorphic mapppings between Reinhardt domains in $\mathbb C^2$

abstract:
  We describe all possibilities of existence of non-elementary proper
holomorphic maps between non-hyperbolic Reinhardt domains in $\mathbb C^2$ and
the corresponding pairs of domains.


title: Noncommutative Deformation of Instantons

abstract:
  We construct instanton solutions on noncommutative Euclidean 4-space which
are deformations of instanton solutions on commutative Euclidean 4-space. We
show that the instanton numbers of these noncommutative instanton solutions
coincide with the commutative solutions and conjecture that the instanton
number in R^4 is preserved for general noncommutative deformations. We also
study noncommutative deformation of instanton solutions on a T^4 with twisted
boundary conditions.


title: Optimal thermoelectric figure of merit of a molecular junction

abstract:
  We show that a molecular junction can give large values of the thermoelectric
figure of merit $ZT$, and so could be used as a solid state energy conversion
device that operates close to the Carnot efficiency. The mechanism is similar
to the Mahan-Sofo model for bulk thermoelectrics -- the Lorenz number goes to
zero violating the Wiedemann-Franz law while the thermopower remains non-zero.
The molecular state through which charge is transported must be weakly coupled
to the leads, and the energy level of the state must be of order $k_B T$ away
from the Fermi energy of the leads. In practice, the figure of merit is limited
by the phonon thermal conductance; we show that the largest possible
$ZT\sim(\tilde{G}_{th}^{ph})^{-1/2}$, where $\tilde{G}_{th}^{ph}$ is the phonon
thermal conductance divided by the thermal conductance quantum.


title:
Three reversible states controlled on a gold monoatomic contact by the
  electrochemical potential

abstract:
  Conductance of an Au mono atomic contact was investigated under the
electrochemical potential control. The Au contact showed three different
behaviors depending on the potential: 1 $G_{0}$ ($G_{0}$ = $2e^{2}/h$), 0.5
$G_{0}$ and not-well defined values below 1 $G_{0}$ were shown when the
potential of the contact was kept at -0.6 V (double layer potential), -1.0 V
(hydrogen evolution potential), and 0.8 V (oxide formation potential) versus
Ag/AgCl in 0.1 M Na$_{2}$SO$_{4}$ solution, respectively. These three
reversible states and their respective conductances could be fully controlled
by the electrochemical potential. These changes in the conductance values are
discussed based on the proposed structure models of hydrogen adsorbed and
oxygen incorporated on an Au mono atomic contact.


title: An Extension of Bochner's Problem: Exceptional Invariant Subspaces

abstract:
  A classical result due to Bochner characterizes the classical orthogonal
polynomial systems as solutions of a second-order eigenvalue equation. We
extend Bochner's result by dropping the assumption that the first element of
the orthogonal polynomial sequence be a constant. This approach gives rise to
new families of complete orthogonal polynomial systems that arise as solutions
of second-order eigenvalue equations with rational coefficients. The results
are based on a classification of exceptional polynomial subspaces of
codimension one under projective transformations.


title: Suzaku Observations of Tycho's Supernova Remnant

abstract:
  Tycho's supernova remnant was observed by the XIS and HXD instruments onboard
the Suzaku satellite on 2006 June 26-29 for 92 ks. The spectrum up to 30 keV
was well fitted with a two-component model, consisting of a power-law with
photon index of 2.7 and a thermal bremsstrahlung model with temperature of 4.7
keV. The former component can alternatively be modeled as synchrotron emission
from a population of relativistic electrons with an estimated roll-off energy
of around 1 keV. In the XIS spectra, in addition to the prominent Fe K_alpha
line (6.445 keV), we observe for the first time significant K_alpha line
emission from the trace species Cr and Mn at energies of 5.48 keV and 5.95 keV,
respectively. Faint K_beta lines from Ca (4.56 keV) and Fe (7.11 keV) are also
seen. The ionization states of Cr and Mn, based on their line centroids, are
estimated to be similar to that of Fe K_alpha (Fe XV or XVI).


title:
Global well-posedness and scattering for the defocusing
  $H^{\frac12}$-subcritical Hartree equation in $\mathbb{R}^d$

abstract:
  We prove the global well-posedness and scattering for the defocusing
$H^{\frac12}$-subcritical (that is, $2<\gamma<3$) Hartree equation with low
regularity data in $\mathbb{R}^d$, $d\geq 3$. Precisely, we show that a unique
and global solution exists for initial data in the Sobolev space
$H^s\big(\mathbb{R}^d\big)$ with $s>4(\gamma-2)/(3\gamma-4)$, which also
scatters in both time directions. This improves the result in \cite{ChHKY},
where the global well-posedness was established for any
$s>\max\big(1/2,4(\gamma-2)/(3\gamma-4)\big)$. The new ingredients in our proof
are that we make use of an interaction Morawetz estimate for the smoothed out
solution $Iu$, instead of an interaction Morawetz estimate for the solution
$u$, and that we make careful analysis of the monotonicity property of the
multiplier $m(\xi)\cdot < \xi>^p$. As a byproduct of our proof, we obtain that
the $H^s$ norm of the solution obeys the uniform-in-time bounds.


title: Bernstein measures on convex polytopes

abstract:
  We define the notion of Bernstein measures and Bernstein approximations over
general convex polytopes. This generalizes well-known Bernstein polynomials
which are used to prove the Weierstrass approximation theorem on one
dimensional intervals. We discuss some properties of Bernstein measures and
approximations, and prove an asymptotic expansion of the Bernstein
approximations for smooth functions which is a generalization of the asymptotic
expansion of the Bernstein polynomials on the standard $m$-simplex obtained by
Abel-Ivan and H\"{o}rmander. These are different from the Bergman-Bernstein
approximations over Delzant polytopes recently introduced by Zelditch. We
discuss relations between Bernstein approximations defined in this paper and
Zelditch's Bergman-Bernstein approximations.


title: Cross Curvature Flow on Locally Homogeneous Three-manifolds (II)

abstract:
  In this paper, we study the positive cross curvature flow on locally
homogeneous 3-manifolds. We describe the long time behavior of these flows. We
combine this with earlier results concerning the asymptotic behavior of the
negative cross curvature flow to describe the two sided behavior of maximal
solutions of the cross curvature flow on locally homogeneous 3-manifolds. We
show that, typically, the positive cross curvature flow on locally homogeneous
3-manifold produce an Heisenberg type sub-Riemannian geometry.


title:
Differential Harnack Estimates for Backward Heat Equations with
  Potentials under the Ricci Flow

abstract:
  In this paper, we derive a general evolution formula for possible Harnack
quantities. As a consequence, we prove several differential Harnack
inequalities for positive solutions of backward heat-type equations with
potentials (including the conjugate heat equation) under the Ricci flow. We
shall also derive Perelman's Harnack inequality for the fundamental solution of
the conjugate heat equation under the Ricci flow.


title:
Staeckel systems generating coupled KdV hierarchies and their finite-gap
  and rational solutions

abstract:
  We show how to generate coupled KdV hierarchies from Staeckel separable
systems of Benenti type. We further show that solutions of these Staeckel
systems generate a large class of finite-gap and rational solutions of cKdV
hierarchies. Most of these solutions are new.


title:
Structural effects of ice grain surfaces on the hydrogenation of CO at
  low temperatures

abstract:
  Experiments on the hydrogenation of CO on crystalline and amorphous ice at 15
K were carried out to investigate the structural effects of the ice surface.
The effective rate of H atom addition to CO on the amorphous ice was found to
be larger than that on the crystalline ice, while CO depletion on crystalline
ice became larger after long exposure.We demonstrated that the CO-coverage on
the ice surfaces dominates the effective reaction rate rather than the surface
structure. The larger depletion of CO on crystalline ice, as compared to
amorphous ice, suggests easier desorption of CO and/or products by the heat of
the reaction.


title: Lineshape Asymmetry for joint CPT and three photon N resonances

abstract:
  We show that a characteristic two photon lineshape asymmetry arises in
coherent population trapping (CPT) and three photon (N) resonances because both
resonances are simultaneously induced by modulation sidebands in the
interrogating laser light. The N resonance is a three-photon resonance in which
a two-photon Raman excitation is combined with a resonant optical pumping
field. This joint CPT and N resonance can be the dominant source of lineshape
distortion, with direct relevance for the operation of miniaturized atomic
frequency standards. We present the results of both an experimental study and
theoretical treatment of the asymmetry of the joint CPT and N resonance under
conditions typical to the operation of an N resonance clock.


title:
Powerful evidences for supporting the claim that gamma-ray burst
  redshifts are gravity-generated

abstract:
  At present, it is widely believed that the phenomenon of the gamma-ray burst
redshift is cosmological origin. From a theoretical point of view, this
redshift has either a cosmological or a cause that is related to gravity.
However, the question of whether the gamma-ray burst redshift has a
cosmological origin or not should be answerable in no uncertain terms because
both the spectrum characteristics and the count distribution law arising from
the two distinct settings are completely different. If the redshift of GRB is
generated by gravity, then the afterglow spectrum will certainly contain both
the gravitational redshits (containing emission and absorption feature) and
Doppler absorption redshift, and hold a definite relation between the two
redshifts. In this paper, we present nine direct and decisive evidences to show
that the gamma-ray burst redshift is indeed generated by gravity of neutron
stars in their merging process; in which, 114 GRBs' redshifts showed that the
statistical count distribution law for the two kinds redshift is the same (with
errors less than 1.5%), and 74 spectral line redshifts of two GRBs showed that
the relation between the two kinds redshift is completely correct (with errors
less than 0.0061%).


title:
Exclusive $B --> \pi \ell^+ \ell^-$ and $B --> \rho \ell^+ \ell^-$
  Decays in the Universal Extra Dimension

abstract:
  We investigate the influence of the universal extra dimension on the
branching ratio in the $B \to \pi(\rho) \ell^+ \ell^-$ decay. Taking $1/R\sim
\{200-1000\}$GeV with one universal extra spatial dimension, which is
consistent with the experimental data for ${\cal B}(B \to X_s \gamma) $, ${\cal
B}(B \to K^\ast \mu^+\mu^- $) and the electroweak precision tests, we obtain
that for both ($\mu,\tau$) channels the branching ratio strongly depends on the
compactification radius 1/R.


title:
High-statistics measurement of neutral-pion pair production in
  two-photon collisions

abstract:
  We present a high-statistics measurement of differential cross sections and
the total cross section for the process gamma gamma -> pi^0 pi^0 in the
kinematic range 0.6 GeV <= W <= 4.0 GeV and |cos theta*| <= 0.8, where W and
theta* are the energy and pion scattering angle, respectively, in the gamma
gamma center-of-mass system. Differential cross sections are fitted to obtain
information on S, D_0, D_2, G_0 and G_2 waves. The G waves are important above
W ~= 1.6 GeV. General behavior of partial waves is studied by fitting
differential cross sections in a simple parameterization where amplitudes
contain resonant contributions and smooth background. The D_2 wave is dominated
by the f_2(1270) meson whose parameters are consistent with the with the
current world averages. The D_0 wave contains a f_2(1270) component, whose
fraction is fitted. For the S wave, the f_0(980) parameters are found to be
consistent with the values determined from our recent pi^+ pi^- data. In
addition to the f_0(980), the S wave prefers to have another resonance-like
contribution whose parameters are obtained.


title:
Threshold for Chaos and Thermalization in One-Dimensional Mean-Field
  Bose-Hubbard Model

abstract:
  We study the threshold for chaos and its relation to thermalization in the 1D
mean-field Bose-Hubbard model, which in particular describes atoms in optical
lattices. We identify the threshold for chaos, which is finite in the
thermodynamic limit, and show that it is indeed a precursor of thermalization.
Far above the threshold, the state of the system after relaxation is governed
by the usual laws of statistical mechanics.


title:
Big-bang nucleosynthesis and the relic abundance of dark matter in a
  stau-neutralino coannihilation scenario

abstract:
  A scenario of the Big-Bang Nucleosynthesis is analyzed within the Minimal
Supersymmetric Standard Model which is consistent with a stau-neutralino
coannihilation scenario to explain the relic abundance of dark matter. We find
that we can account for the possible descrepancy of the abundance of
$\mathrm{^{7}Li}$ between the observation and the prediction of the Big-Bang
Nucleosynthesis by taking the mass of the neutralino as $300 \mathrm{GeV}$ and
the mass difference between the stau and the neutralino as $(100 -- 120) MeV$.
We can therefore simultaneously explain the abundance of the dark matter and
that of $\mathrm{^{7}Li}$ by these values of parameters. The lifetime of staus
in this scenario is predicted to be $O(100 -- 1000) sec$.


title:
Design of Attitude Stability System for Prolate Dual-spin Satellite in
  Its Inclined Elliptical Orbit

abstract:
  In general, most of communication satellites were designed to be operated in
geostationary orbit. And many of them were designed in prolate dual-spin
configuration. As a prolate dual-spin vehicle, they have to be stabilized
against their internal energy dissipation effect. Several countries that
located in southern hemisphere, has shown interest to use communication
satellite. Because of those countries southern latitude, an idea emerged to
incline the communication satellite (due to its prolate dualspin configuration)
in elliptical orbit. This work is focused on designing Attitude Stability
System for prolate dual-spin satellite in the effect of perturbed field of
gravity due to the inclination of its elliptical orbit. DANDE (De-spin Active
Nutation Damping Electronics) provides primary stabilization method for the
satellite in its orbit. Classical Control Approach is used for the iteration of
DANDE parameters. The control performance is evaluated based on time response
analysis.


title: A First Sight Towards Primitively Generated Connected Braided Bialgebras

abstract:
  The main aim of this paper is to investigate the structure of primitively
generated connected braided bialgebras $A$ with respect to the braided vector
space $P$ consisting of their primitive elements. When the Nichols algebra of
$P$ is obtained dividing out the tensor algebra $T(P) $ by the two-sided ideal
generated by its primitive elements of degree at least two, we show that $A$
can be recovered as a sort of universal enveloping algebra of $P$. One of the
main applications of our construction is the description, in terms of universal
enveloping algebras, of connected braided bialgebras whose associated graded
coalgebra is a quadratic algebra.


title: A Low Complexity Scheme for Entanglement Distributor Buses

abstract:
  For technological purposes and theoretical curiosity, it is very interesting
to have a building block that produces a considerable amount of entanglement
between on-demand sites through a simple control of a few sites. Here, we
consider permanently-coupled spin networks and study entanglement generation
between qubit pairs to find low-complexity structures capable of generating
considerable entanglement between various qubit pairs. We find that in axially
symmetric networks the generated entanglement between some qubit pairs is
rather larger than generic networks. We show that in uniformly-coupled spin
rings each pair can be considerably entangled through controlling suitable
vertices. To set the location of controlling-vertices, we observe that the
symmetry has to be broken for a definite time. To achieve this, a magnetic flux
can be applied to break symmetry via Aharonov-Bohm effect. Such a set up can
serve as an efficient entanglement distributor bus in which each vertex-pair
can be efficiently entangled through exciting only one fixed vertex and
controlling the evolution time. The low-complexity of this scheme makes it
attractive for use in nanoscale quantum information processors.


title:
Predicting polarization and nonlinear dielectric response of arbitrary
  perovskite superlattice sequences

abstract:
  We carry out first-principles calculations of the nonlinear dielectric
response of short-period ferroelectric superlattices. We compute and store not
only the total polarization, but also the Wannier-based polarizations of
individual atomic layers, as a function of electric displacement field, and use
this information to construct a model capable of predicting the nonlinear
dielectric response of an arbitrary superlattice sequence. We demonstrate the
successful application of our approach to superlattices composed of SrTiO$_3$,
CaTiO$_3$, and BaTiO$_3$ layers.


title: Estimation in models driven by fractional Brownian motion

abstract:
  Let $\{b_H(t),t\in\mathbb{R}\}$ be the fractional Brownian motion with
parameter $0<H<1$. When $1/2<H$, we consider diffusion equations of the type
\[X(t)=c+\int_0^t\sigma\bigl(X(u)\bigr)\mathrm {d}b_H(u)+\int
_0^t\mu\bigl(X(u)\bigr)\mathrm {d}u.\] In different particular models where
$\sigma(x)=\sigma$ or $\sigma(x)=\sigma x$ and $\mu(x)=\mu$ or $\mu(x)=\mu x$,
we propose a central limit theorem for estimators of $H$ and of $\sigma$ based
on regression methods. Then we give tests of the hypothesis on $\sigma$ for
these models. We also consider functional estimation on $\sigma(\cdot)$ in the
above more general models based in the asymptotic behavior of functionals of
the 2nd-order increments of the fBm.


title:
Detecting single-electron tunneling involving virtual processes in real
  time

abstract:
  We use time-resolved charge detection techniques to probe virtual tunneling
processes in a double quantum dot. The process involves an energetically
forbidden state separated by an energy $\delta$ from the Fermi energy in the
leads. The non-zero tunneling probability can be interpreted as cotunneling,
which occurs as a direct consequence of time-energy uncertainty. For small
energy separation the electrons in the quantum dots delocalize and form
molecular states. In this regime we establish the experimental equivalence
between cotunneling and sequential tunneling into molecular states for electron
transport in a double quantum dot. Finally, we investigate inelastic
cotunneling processes involving excited states of the quantum dots. Using the
time-resolved charge detection techniques, we are able to extract the shot
noise of the current in the cotunneling regime.


title: Dynamics of entanglement in a one-dimensional Ising chain

abstract:
  The evolution of entanglement in a one-dimensional Ising chain is numerically
studied under various initial conditions. We analyze two problems concerning
the dynamics of the entanglement: (i) generation of the entanglement from the
pseudopure separable state and (ii) transportation of the entanglement from one
end of the chain to the other. The investigated model is a one-dimensional
Ising spin-1/2 chain with nearest-neighbor interactions placed in an external
magnetic field and irradiated by a weak resonant transverse field. The
possibility of selective initialization of partially entangled states is
considered. It was shown that, in spite of the use of a model with the direct
interactions between the nearest neighbors, the entanglement between remote
spins is generated.


title:
How to quantify the influence of correlations on investment
  diversification

abstract:
  When assets are correlated, benefits of investment diversification are
reduced. To measure the influence of correlations on investment performance, a
new quantity - the effective portfolio size - is proposed and investigated in
both artificial and real situations. We show that in most cases, the effective
portfolio size is much smaller than the actual number of assets in the
portfolio and that it lowers even further during financial crises.


title:
Proposed Experimental Test for Proving Quantum Contextuality with
  Non-entangled Photons

abstract:
  We present a new and feasible test proving quantum contextuality in
four-dimensional Hiltbert space. In our scheme, a contradiction between quantum
mechanics and noncontextual hidden variables is revealed through the
measurement statistics of two joint measurements of an ensemble of
non-entangled qubits. The origin of nonclassicality is fully attributed to the
measurement process. Quantum optical realization using photon pairs and linear
optics are presented.


title: Galactic interstellar 18O/17O ratios - a radial gradient?

abstract:
  (Abridged) Our aim is to determine 18O/17O abundance ratios across the entire
Galaxy. These provide a measure of the amount of enrichment by high-mass versus
intermediate-mass stars. Such ratios, derived from the C18O and C17O J=1-0
lines alone, may be affected by systematic errors. Therefore, the C18O and C17O
(1-0), (2-1), and (3-2), as well as the 13CO (1-0) and (2-1) lines, were
observed towards 18 prominent galactic targets (a total of 25 positions). The
combined dataset was analysed with an LVG model, accounting for optical depth
effects. The data cover galactocentric radii R between 0.1 and 16.9 kpc (solar
circle at 8.5 kpc). Near the centre of the Galaxy, 18O/17O = 2.88 +/- 0.11. For
the galactic disc out to an R of ca. 10 kpc, 18O/17O = 4.16 +/- 0.09. At ca. R
= 16.5 kpc, 18O/17O = 5.03 +/- 0.46. Assuming that 18O is synthesised
predominantly in high-mass stars (M > 8 Msun), while C17O is mainly a product
of lower-mass stars, the ratio from the inner Galaxy indicates a dominance of
CNO-hydrogen burning products that is also apparent in the C- and N-isotope
ratios. The high 18O/17O value of the solar system (5.5) relative to that of
the ambient ISM suggests contamination by nearby high-mass stars during its
formation. High values in the metal-poor environment of the outer Galaxy are
not matched by the low values observed towards the even more metal-poor LMC.
Apparently, the outer Galaxy cannot be considered as an intermediate
environment between the solar neighbourhood and the ISM of small metal-poor
galaxies. The apparent 18O/17O gradient along the galactic disc and the
discrepancy between outer disc and LMC isotope ratios may be explained by
different ages of the respective stellar populations.


title:
Derivation of Non-Local Macroscopic Traffic Equations and Consistent
  Traffic Pressures from Microscopic Car-Following Models

abstract:
  This contribution compares several different approaches allowing one to
derive macroscopic traffic equation directly from microscopic car-following
models. While it is shown that some conventional approaches lead to theoretical
problems, it is proposed to use a smooth particle hydrodynamic approach and to
avoid gradient expansions. The derivation circumvents approximations and,
therefore, demonstrates the large range of validity of macroscopic traffic
equations, without the need of averaging over many vehicles. It also gives an
expression for the ``traffic pressure'', which generalizes previously used
formulas. Furthermore, the method avoids theoretical inconsistencies of
macroscopic traffic models, which have been criticized in the past by Daganzo
and others.


title: Direct photons from relativistic heavy-ion collisions

abstract:
  We recall the seminal developments in the study of radiation of direct
photons from relativistic heavy ion collisions, which have helped to enhance
the scope of single photons as a probe of the quark gluon plasma considerably.
There is a mounting evidence that in addition to providing information about
the initial temperature of the plasma as envisaged originally, these radiations
measure the momentum anisotropy of the deconfined quarks and gluons, energy
loss of the quarks, the initial spatial asymmetry of the plasma, and the
history of evolution of the system. After a brief description of the
theoretical developments and results for direct photons at SPS energies, we
discuss the expectations and findings at RHIC.


title:
On the Controversy around Daganzo's Requiem for and Aw-Rascle's
  Resurrection of Second-Order Traffic Flow Models

abstract:
  Daganzo's criticisms of second-order fluid approximations of traffic flow [C.
Daganzo, Transpn. Res. B. 29, 277-286 (1995)] and Aw and Rascle's proposal how
to overcome them [A. Aw and M. Rascle, SIAM J. Appl. Math. 60, 916-938 (2000)]
have stimulated an intensive scientific activity in the field of traffic
modeling. Here, we will revisit their arguments and the interpretations behind
them. We will start by analyzing the linear stability of traffic models, which
is a widely established approach to study the ability of traffic models to
describe emergent traffic jams. Besides deriving a collection of useful
formulas for stability analyses, the main attention is put on the
characteristic speeds, which are related to the group velocities of the
linearized model equations. Most macroscopic traffic models with a dynamic
velocity equation appear to predict two characteristic speeds, one of which is
faster than the average velocity. This has been claimed to constitute a
theoretical inconsistency. We will carefully discuss arguments for and against
this view. In particular, we will shed some new light on the problem by
comparing Payne's macroscopic traffic model with the Aw-Rascle model and
macroscopic with microscopic traffic models.