title:
Does confining the hard-sphere fluid between hard walls change its
  average properties?

abstract:
  We use grand canonical transition-matrix Monte Carlo and discontinuous
molecular dynamics simulations to generate precise thermodynamic and kinetic
data for the equilibrium hard-sphere fluid confined between smooth hard walls.
These simulations show that the pronounced inhomogeneous structuring of the
fluid normal to the confining walls, often the primary focus of density
functional theory studies, has a negligible effect on many of its average
properties over a surprisingly broad range of conditions. We present one
consequence of this insensitivity to confinement: a simple analytical equation
relating the average density of the confined fluid to that of the bulk fluid
with equal activity. Nontrivial implications of confinement for average fluid
properties do emerge in this system, but only when the fluid is both (i) dense
and (ii) confined to a gap smaller than approximately three particle diameters.
For this limited set of conditions, we find that "in-phase" oscillatory
deviations in excess entropy and self-diffusivity (relative to the behavior of
the bulk fluid at the same average density) occur as a function of gap size.
These paired thermodynamic/kinetic deviations from bulk behavior appear to
reflect the geometric packing frustration that arises when the confined space
cannot naturally accommodate an integer number of particle layers.


title:
Evidence that FeLoBALs may signify the transition between an
  ultraluminous infrared galaxy and a quasar

abstract:
  We present mid/far-infrared photometry of nine FeLoBAL QSOs, taken using the
Spitzer space telescope. All nine objects are extremely bright in the infrared,
with rest-frame 1-1000 micron luminosities comparable to those of Ultraluminous
Infrared Galaxies. Furthermore, a significant fraction of the infrared emission
from many, and possibly all of the sample is likely to arise from star
formation, with star formation rates of order several hundred solar masses per
year. We combine these results with previous work to propose that FeLoBALs mark
galaxies and QSOs in which an extremely luminous starburst is approaching its
end, and in which a rapidly accreting supermassive black hole is in the last
stages of casting off its dust cocoon. FeLoBAL signatures in high redshift QSOs
and galaxies may thus be an efficient way of selecting sources at a critical
point in their evolution.


title:
Ultraluminous Infrared Galaxies at 1.5<z<3 occupy dark matter haloes of
  mass ~6x10^13 solar masses

abstract:
  We present measurements of the spatial clustering of ultraluminous infrared
galaxies in two redshift intervals, 1.5<z<2.0 and 2<z<3. Both samples cluster
strongly, with r_0=14.40+/-1.99 h^-1 Mpc for the 2<z<3 sample, and
r_0=9.40+/-2.24 h^-1 Mpc for the 1.5<z<2.0 sample, making them among the most
biased galaxies at these epochs. These clustering amplitudes are consistent
with both populations residing in dark matter haloes with masses of ~6x10^13
solar masses. We infer that a minimum dark matter halo mass is an important
factor for all forms of luminous, obscured activity in galaxies at z>1.
Adopting plausible models for the growth of DM haloes with redshift, then the
haloes hosting the 2<z<3 sample will likely host the richest clusters of
galaxies at z=0, whereas the haloes hosting the 1.5<z<2.0 sample will likely
host poor to rich clusters at z=0.


title:
Conditions for the Quantum to Classical Transition: Trajectories vs.
  Phase Space Distributions

abstract:
  We contrast two sets of conditions that govern the transition in which
classical dynamics emerges from the evolution of a quantum system. The first
was derived by considering the trajectories seen by an observer (dubbed the
``strong'' transition) [Bhattacharya, et al., Phys. Rev. Lett. 85: 4852
(2000)], and the second by considering phase-space densities (the ``weak''
transition) [Greenbaum, et al., Chaos 15, 033302 (2005)]. On the face of it
these conditions appear rather different. We show, however, that in the
semiclassical regime, in which the action of the system is large compared to
$\hbar$, and the measurement noise is small, they both offer an essentially
equivalent local picture. Within this regime, the weak conditions dominate
while in the opposite regime where the action is not much larger than Planck's
constant, the strong conditions dominate.


title: The Answer is Blowing in the Wind

abstract: A 'News & Views' article -- no abstract.


title: On tractability and congruence distributivity

abstract:
  Constraint languages that arise from finite algebras have recently been the
object of study, especially in connection with the Dichotomy Conjecture of
Feder and Vardi. An important class of algebras are those that generate
congruence distributive varieties and included among this class are lattices,
and more generally, those algebras that have near-unanimity term operations. An
algebra will generate a congruence distributive variety if and only if it has a
sequence of ternary term operations, called Jonsson terms, that satisfy certain
equations.
  We prove that constraint languages consisting of relations that are invariant
under a short sequence of Jonsson terms are tractable by showing that such
languages have bounded relational width.


title:
Detection of exchange interaction in STM measurements through Fanolike
  interference effects

abstract:
  We address Fano-like interference effects in scanning tunneling microscopy
(STM) measurements of nanoscale systems, e.g. two-level systems. Common for
these systems is that second order tunneling contributions give rise to
interference effects that cause suppressed transmission through the system for
certain energies. The suppressed transmission is measurable either in the
differential conductance or in the bias voltage derivative thereof.


title: Stellar masers, circumstellar envelopes, and supernova remnants

abstract:
  This paper reviews recent advances in the study or circumstellar masers and
masers found toward supernova remnants. The review is organized by science
focus area, including the astrophysics of extended stellar atmospheres, stellar
mass-loss processes and outflows, late-type evolved stellar evolution, stellar
maser excitation and chemistry, and the use of stellar masers as independent
distance estimators. Masers toward supernova remnants are covered separately.
Recent advances and open future questions in this field are explored.


title:
Mass Loss Evolution and the Formation of Detached Shells around TP-AGB
  Stars

abstract:
  The origin of the so called 'detached shells' around AGB stars is not fully
understood, but two common hypotheses state that these shells form either
through the interaction of distinct wind phases or an eruptive mass loss
associated with a He-shell flash. We present a model of the formation of
detached shells around thermal pulse asymptotic giant branch (TP-AGB) stars,
based on detailed modelling of mass loss and stellar evolution, leading to a
combination of eruptive mass loss and wind interaction.
  The purpose of this paper is first of all to connect stellar evolution with
wind and mass loss evolution and demonstrate its consistency with observations,
but also to show how thin detached shells around TP-AGB stars can be formed.
Previous attempts to link mass loss evolution with the formation of detached
shells were based on approximate prescriptions for the mass loss and have not
included detailed modelling of the wind formation as we do here. (abridged)


title: Gravitational anomalies: a recipe for Hawking radiation

abstract:
  We explore the method of Robinson and Wilczek for deriving the Hawking
temperature of a black hole. In this method, the Hawking radiation restores
general covariance in an effective theory of near-horizon physics which
otherwise exhibits a gravitational anomaly at the quantum level. The method has
been shown to work for broad classes of black holes in arbitrary spacetime
dimensions. These include static black holes, accreting or evaporating black
holes, charged black holes, rotating black holes, and even black rings. In the
case of charged and rotating black holes, the expected super-radiant current is
also reproduced.


title:
New supersymmetric solutions of N=2, D=5 gauged supergravity with
  hyperscalars

abstract:
  We construct new supersymmetric solutions, including AdS bubbles, in an N=2
truncation of five-dimensional N=8 gauged supergravity. This particular
truncation is given by N=2 gauged supergravity coupled to two vector multiples
and three incomplete hypermultiplets, and was originally investigated in the
context of obtaining regular AdS bubble geometries with multiple active
R-charges. We focus on cohomogeneity-one solutions corresponding to objects
with two equal angular momenta and up to three independent R-charges.
Curiously, we find a new set of zero and negative mass solitons asymptotic to
AdS_5/Z_k, for k \ge 3, which are everywhere regular without closed timelike
curves.


title:
Response Prediction of Structural System Subject to Earthquake Motions
  using Artificial Neural Network

abstract:
  This paper uses Artificial Neural Network (ANN) models to compute response of
structural system subject to Indian earthquakes at Chamoli and Uttarkashi
ground motion data. The system is first trained for a single real earthquake
data. The trained ANN architecture is then used to simulate earthquakes with
various intensities and it was found that the predicted responses given by ANN
model are accurate for practical purposes. When the ANN is trained by a part of
the ground motion data, it can also identify the responses of the structural
system well. In this way the safeness of the structural systems may be
predicted in case of future earthquakes without waiting for the earthquake to
occur for the lessons. Time period and the corresponding maximum response of
the building for an earthquake has been evaluated, which is again trained to
predict the maximum response of the building at different time periods. The
trained time period versus maximum response ANN model is also tested for real
earthquake data of other place, which was not used in the training and was
found to be in good agreement.


title:
Fault Classification using Pseudomodal Energies and Neuro-fuzzy
  modelling

abstract:
  This paper presents a fault classification method which makes use of a
Takagi-Sugeno neuro-fuzzy model and Pseudomodal energies calculated from the
vibration signals of cylindrical shells. The calculation of Pseudomodal
Energies, for the purposes of condition monitoring, has previously been found
to be an accurate method of extracting features from vibration signals. This
calculation is therefore used to extract features from vibration signals
obtained from a diverse population of cylindrical shells. Some of the cylinders
in the population have faults in different substructures. The pseudomodal
energies calculated from the vibration signals are then used as inputs to a
neuro-fuzzy model. A leave-one-out cross-validation process is used to test the
performance of the model. It is found that the neuro-fuzzy model is able to
classify faults with an accuracy of 91.62%, which is higher than the previously
used multilayer perceptron.


title:
Magnetic, magneto-thermal and magneto-transport properties in
  SmMn2Si2-xGex compounds

abstract:
  The effect of Ge substitution for Si in SmMMn2Si2-xGex compounds has been
studied. The Sm ordering temperature is found to be much larger in the compound
with x=2, as compared to the compounds with x=0 and 1. The increase in the
intra layer Mn-Mn distance is found to be responsible for this increase. Among
these three compounds, SmMn2Ge2 is found to show re-entrant ferromagnetism at
low temperatures. The magnetic contribution to the heat capacity has been found
in all the three compounds. The splitting of the ground state multiplet has
been estimated by fitting the magnetic part of the heat capacity data using the
Schottky formula. The isothermal magnetic entropy change is found to remain the
same for x=0 and 1, but decrease in the compound with x=2, though the nature of
magnetic transition changes from second order to first order, as x is increased
from 0 to 2. The electrical resistivity increases with Ge concentration. The
excess resistivity in the antiferromagnetic region has been calculated.


title:
A unified model for AGN feedback in cosmological simulations of
  structure formation

abstract:
  We discuss a numerical model for black hole growth and its associated
feedback processes that for the first time allows cosmological simulations of
structure formation to self-consistently follow the build up of the cosmic
population of galaxies and active galactic nuclei. Our model assumes that seed
black holes are present at early cosmic epochs at the centres of forming halos.
We then track their growth from gas accretion and mergers with other black
holes in the course of cosmic time. For black holes that are active, we
distinguish between two distinct modes of feedback, depending on the black hole
accretion rate itself. Black holes that accrete at high rates are assumed to be
in a `quasar regime', where we model their feedback by thermally coupling a
small fraction of their bolometric luminosity to the surrounding gas. For black
holes with low accretion rates, we conjecture that most of their feedback
occurs in mechanical form, where AGN-driven bubbles are injected into a gaseous
environment. Using our new model, we carry out TreeSPH cosmological simulations
on the scales of individual galaxies to those of massive galaxy clusters, both
for isolated systems and for cosmological boxes. We demonstrate that our model
produces results for the black hole and stellar mass densities in broad
agreement with observational constraints. We find that the black holes
significantly influence the evolution of their host galaxies, changing their
star formation history, their amount of cold gas, and their colours. Also, the
properties of intracluster gas are affected strongly by the presence of massive
black holes in the cores of galaxy clusters, leading to shallower metallicity
and entropy profiles, and to a suppression of strong cooling flows. [Abridged]


title:
Electrodynamics of Josephson vortex lattice in high-temperature
  superconductors

abstract:
  We studied response of the Josephson vortex lattice in layered
superconductors to the high-frequency c-axis electric field. We found a simple
relation connecting the dynamic dielectric constant with the perturbation of
the superconducting phase, induced by oscillating electric field. Numerically
solving equations for the oscillating phases, we computed the frequency
dependences of the loss function at different magnetic fields, including
regions of both dilute and dense Josephson vortex lattices. The overall
behavior is mainly determined by the c-axis and in-plane dissipation
parameters, which is inversely proportional to the anisotropy. The cases of
weak and strong dissipation are realized in
$\mathrm{Bi_{2}Sr_{2}CaCu_{2}O_{x}}$ and underdoped $\mathrm{YBa_{2}Cu_{3}
O_{x}}$ correspondingly. The main feature of the response is the
Josephson-plasma-resonance peak. In the weak-dissipation case additional
satellites appear in the dilute regime mostly in the higher-frequency region
due to excitation of the plasma modes with the wave vectors set by the lattice
structure. In the dense-lattice limit the plasma peak moves to higher frequency
and its intensity rapidly decreases, in agreement with experiment and
analytical theory. Behavior of the loss function at low frequencies is well
described by the phenomenological theory of vortex oscillations. In the case of
very strong in-plane dissipation an additional peak in the loss function
appears below the plasma frequency. Such peak has been observed experimentally
in underdoped $\mathrm{YBa_{2}Cu_{3} O_{x}}$. It is caused by frequency
dependence of in-plane contribution to losses rather then a definite mode of
phase oscillations.


title: Spitzer observations of a 24 micron shadow: Bok Globule CB190

abstract:
  We present Spitzer observations of the dark globule CB190 (L771). We observe
a roughly circular 24 micron shadow with a 70 arcsec radius. The extinction
profile of this shadow matches the profile derived from 2MASS photometry at the
outer edges of the globule and reaches a maximum of ~32 visual magnitudes at
the center. The corresponding mass of CB190 is ~10 Msun. Our 12CO and 13CO J =
2-1 data over a 10 arcmin X 10 arcmin region centered on the shadow show a
temperature ~10 K. The thermal continuum indicates a similar temperature for
the dust. The molecular data also show evidence of freezeout onto dust grains.
We estimate a distance to CB190 of 400 pc using the spectroscopic parallax of a
star associated with the globule. Bonnor-Ebert fits to the density profile, in
conjunction with this distance, yield xi_max = 7.2, indicating that CB190 may
be unstable. The high temperature (56 K) of the best fit Bonnor-Ebert model is
in contradiction with the CO and thermal continuum data, leading to the
conclusion that the thermal pressure is not enough to prevent free-fall
collapse. We also find that the turbulence in the cloud is inadequate to
support it. However, the cloud may be supported by the magnetic field, if this
field is at the average level for dark globules. Since the magnetic field will
eventually leak out through ambipolar diffusion, it is likely that CB190 is
collapsing or in a late pre-collapse stage.


title: A New Measure of Fine Tuning

abstract:
  The solution to fine tuning is one of the principal motivations for Beyond
the Standard Model (BSM) Studies. However constraints on new physics indicate
that many of these BSM models are also fine tuned (although to a much lesser
extent). To compare these BSM models it is essential that we have a reliable,
quantitative measure of tuning. We review the measures of tuning used in the
literature and propose an alternative measure. We apply this measure to several
toy models and the Minimal Supersymmetric Standard Model.


title: The Search for Million Degree Gas Through The NVII Hyperfine Line

abstract:
  Gas in the million degree range occurs in a variety of astronomical
environments, and it may be the main component of the elusive missing baryons
at low redshift. The NVII ion is found in this material and it has a hyperfine
spin-flip transition with a rest frequency of 53.042 GHz, which can be observed
for z > 0.1, when it is shifted into a suitably transparent radio band. We used
the 42-48 GHz spectrometer on the Green Bank Telescope to search for both
emission and absorption from this NVII transmission. For absorption studies,
3C273, 3C 279, 3C 345, and 4C+39.25 were observed but no feature were seen
above the 5 sigma level. For emission line studies, we observed Abell 1835,
Abell 2390 and the star-forming galaxy PKS 1345+12, but no features were seen
exceeding 5 sigma. We examine whether the strongest emission feature, in Abell
2390 (3.7 sigma), and the strongest absorption feature, toward 4C+39.25 (3.8
sigma), might be expected from theoretical models. The emission feature would
require ~1E10 Msolar of 1E6 K gas, which is inconsistent with X-ray limits for
the O VII Kalpha line, so it is unlikely to be real. The NVII absorption
feature requires a NVII column of 6E16 cm^-2, higher than model predictions by
at least an order of magnitude, which makes it inconsistent with model
expectations. The individual observations were less than 1 hr in length, so for
lengthy observations, we show that NVII absorption line observations can begin
to be useful in in the search for hot intergalactic gas.


title: Secure sharing of random bits over the Internet

abstract:
  Although one-time pad encrypted files can be sent through Internet channels,
the need for renewing shared secret keys have made this method unpractical.
This work presents a scheme to turn practical the fast sharing of random keys
over arbitrary Internet channels. Starting with a shared secret key sequence of
length K_0 the users end up with a secure new sequence K >> K_0. Using these
sequences for posteriori message encryption the legitimate users have absolute
security control without the need for third parties. Additionally, the security
level does not depend on the unproven difficulty of factoring numbers in
primes. In the proposed scheme a fast optical random source generates random
bits and noise for key renewals. The transmitted signals are recorded signals
that carries both the random binary signals to be exchanged and physical noise
that cannot be eliminated by the attacker. These signals allow amplification
over the Internet network without degrading security. The proposed system is
also secure against a-posteriori known-plaintext attack on the key.
Information-theoretic analysis is presented and bounds for secure operation are
quantitatively determined.


title:
Viscous Torque and Dissipation in the Inner Region of a Thin Accretion
  Disk: Implications for Measuring Black Hole Spin

abstract:
  We consider a simple Newtonian model of a steady accretion disk around a
black hole. The model is based on height-integrated hydrodynamic equations,
alpha-viscosity, and a pseudo-Newtonian potential that results in an innermost
stable circular orbit (ISCO) that closely approximates the one predicted by GR.
We find that the hydrodynamic models exhibit increasing deviations from the
standard disk model of Shakura & Sunyaev as disk thickness H/R or the value of
alpha increases. The latter is an analytical model in which the viscous torque
is assumed to vanish at the ISCO. We consider the implications of the results
for attempts to estimate black hole spin by using the standard disk model to
fit continuum spectra of black hole accretion disks. We find that the error in
the spin estimate is quite modest so long as H/R < 0.1 and alpha < 0.2. At
worst the error in the estimated value of the spin parameter is 0.1 for a
non-spinning black hole; the error is much less for a rapidly spinning hole. We
also consider the density and disk thickness contrast between the gas in the
disk and that inside the ISCO. The contrast needs to be large if black hole
spin is to be successfully estimated by fitting the relativistically-broadened
X-ray line profile of fluorescent iron emission from reflection off an
accretion disk. In our hydrodynamic models, the contrast in density and
thickness is low when H/R>0.1, sugesting that the iron line technique may be
most reliable in extemely thin disks. We caution that these results have been
obtained with a viscous hydrodynamic model and need to be confirmed with MHD
simulations of radiatively cooled thin disks.


title:
Wightman function and vacuum densities for a Z_2-symmetric thick brane
  in AdS spacetime

abstract:
  Positive frequency Wightman function, vacuum expectation values of the field
square and the energy-momentum tensor induced by a Z_{2}-symmetric brane with
finite thickness located on (D+1)- dimensional AdS background are evaluated for
a massive scalar field with general curvature coupling parameter. For the
general case of static plane symmetric interior structure the expectation
values in the region outside the brane are presented as the sum of free AdS and
brane induced parts. For a conformally coupled massless scalar the brane
induced part in the vacuum energy-momentum tensor vanishes. In the limit of
strong gravitational fields the brane induced parts are exponentially
suppressed for points not too close to the brane boundary. As an application of
general results a special model is considered in which the geometry inside the
brane is a slice of the Minkowski spacetime orbifolded along the direction
perpendicular to the brane. For this model the Wightman function, vacuum
expectation values of the field square and the energy-momentum tensor inside
the brane are evaluated as well and their behavior is discussed in various
asymptotic regions of the parameters. It is shown that for both minimally and
conformally coupled scalar fields the interior vacuum forces acting on the
brane boundaries tend to decrease the brane thickness.


title:
Old Metal-rich Globular Cluster Populations: Peak Color and Peak
  Metallicity Trends with Mass of Host Spheroids

abstract:
  We address the problem of the factors contributing to a peak color trend of
old metal-rich globular cluster (MRGC) populations with mass of their hosts,
early-type galaxies and spheroidal subsystems of spiral ones (spheroids). The
color-mass trend is often converted to a metallicity-mass trend under the
assumption that age effects are small or negligible. While direct estimates of
the ages of MRGC populations neither can rule out nor reliably support the
populations' age trend, key data on timing of the formation of spheroids and
other indirect evidence imply it in the sense: the more massive spheroid the
older on average its MRGC population. We show that the contribution of an
allowable age trend of the MRGC populations to their peak color trend can
achieve up to ~50 % or so. In this event the comparable value of the color
trend, ~30 %, is due to alpha-element ratio systematic variations of the order
of Delta[alpha/Fe] ~ 0.1 to 0.2 dex because of a correlation between the
[alpha/Fe] ratios and age. Hence a systematic variation of exactly [Fe/H]
ratios may turn out to be less significant among the contributors, and its
range many times lower, i.e. of the order of Delta[Fe/H] ~ 0.1 or even none,
than the corresponding range deduced by assuming no age trend.


title:
Limits on Anomalous Triple Gauge Couplings in ppbar Collisions at
  sqrt{s}=1.96 TeV

abstract:
  We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ
boson production. The boson pairs are produced in ppbar collisions at
sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated
luminosity collected with the CDF II detector at the Fermilab Tevatron. In this
search one W decays to leptons, and the other boson (W or Z) decays
hadronically. Combining with a previously published CDF measurement of Wgamma
boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta
kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.


title: Dalitz plot analysis of the D+ to K-pi+pi+ decay in the FOCUS experiment

abstract:
  Using data collected by the high energy photoproduction experiment FOCUS at
Fermilab we performed a Dalitz plot analysis of the Cabibbo favored decay D+ to
K-pi+ pi+. This study uses 53653 Dalitz-plot events with a signal fraction of ~
97%, and represents the highest statistics, most complete Dalitz plot analysis
for this channel. Results are presented and discussed using two different
formalisms. The first is a simple sum of Breit--Wigner functions with freely
fitted masses and widths. It is the model traditionally adopted and serves as
comparison with the already published analyses. The second uses a K-matrix
approach for the dominant S-wave, in which the parameters are fixed by first
fitting Kpi scattering data and continued to threshold by Chiral Perturbation
Theory. We show that the Dalitz plot distribution for this decay is consistent
with the assumption of two body dominance of the final state interactions and
the description of these interactions is in agreement with other data on the
Kpi final state.


title: Supersymmetrizing Landau Models

abstract:
  This is an overview of recent progress in constructing and studying
superextensions of the Landau problem of a quantum particle on a plane in the
uniform magnetic field, as well as of its Haldane's $S^2$ generalization ({\tt
hep-th/0311159, hep-th/0404108, hep-th/0510019, hep-th/0612300}). The main
attention is paid to the planar super Landau models which are invariant under
the inhomogeneous supergroup ISU(1|1), a contraction of the supergroup SU(2|1),
and provide minimal superextensions of the original Landau model. Their common
notable feature is the presence of a hidden dynamical worldline N=2
supersymmetry. It exists at the classical and quantum levels and is revealed
most naturally while passing to the new invariant inner products in the space
of quantum states in order to make the norms of all states positive. For one of
the planar models, the superplane Landau model, we present an off-shell
worldline superfield formulation in which the N=2 supersymmetry gets manifest.


title: Topological Quiver Matrix Models and Quantum Foam

abstract:
  We study the matrix models that describe the BPS bound states of branes
arising from the quiver picture of the derived category. These theories have a
topological partition function that localizes to the Euler character of the
anti-ghost bundle over the classical BPS moduli space. We examine the effective
internal geometry of D6/D2 bound states in the local vertex geometry, using BPS
0-brane probes. The Kahler blowups of the Calabi-Yau that we find utilizing
these quiver theories are a realization of A-model quantum foam in the full IIA
theory.


title: Chaos and complexity in astrophysics

abstract:
  Methods and techniques of the theory of nonlinear dynamical systems and
patterns can be useful in astrophysical applications. Some works on the
subjects of dynamical astronomy, stellar pulsation and variability, as well as
spatial complexity in extended systems, in which such approaches have already
been utilized, are reviewed. Prospects for future directions in applications of
this kind are outlined.


title: Inducing charges and currents from extra dimensions

abstract:
  In a particular variant of Kaluza-Klein theory, the so-called induced-matter
theory (IMT), it is shown that any configuration of matter may be geometrically
induced from a five-dimensional vacuum space. By using a similar approach we
show that any distribution of charges and currents may also be induced from a
five-dimensional vacuum space. Whereas in the case of IMT the geometry is
Riemannian and the fundamental equations are the five-dimensional Einstein
equations in vacuum, here we consider a Minkowskian geometry and the
five-dimensional Maxwell equations in vacuum.


title: On the convergence to equilibrium of Kac's random walk on matrices

abstract:
  We consider Kac's random walk on $n$-dimensional rotation matrices, where
each step is a random rotation in the plane generated by two randomly picked
coordinates. We show that this process converges to the Haar measure on
$\mathit{SO}(n)$ in the $L^2$ transportation cost (Wasserstein) metric in
$O(n^2\ln n)$ steps. We also prove that our bound is at most a $O(\ln n)$
factor away from optimal. Previous bounds, due to Diaconis/Saloff-Coste and
Pak/Sidenko, had extra powers of $n$ and held only for $L^1$ transportation
cost. Our proof method includes a general result of independent interest, akin
to the path coupling method of Bubley and Dyer. Suppose that $P$ is a Markov
chain on a Polish length space $(M,d)$ and that for all $x,y\in M$ with
$d(x,y)\ll1$ there is a coupling $(X,Y)$ of one step of $P$ from $x$ and $y$
(resp.) that contracts distances by a $(\xi+o(1))$ factor on average. Then the
map $\mu\mapsto\mu P$ is $\xi$-contracting in the transportation cost metric.


title: Quasi-normal modes for black hole solutions unknown in analytical form

abstract:
  We review the papers [1-3]. We discuss possibilities of studying the
quasi-normal modes of black holes that are not known in an analytical form.
Such black holes appear as solutions in various theoretical models and real
astrophysical approximations when one takes into account the black hole
neighborhood.


title: Torsion Energy

abstract:
  In the present work, torsion energy is defined. Its law of conservation is
given. It is shown that this type of energy gives rise to a repulsive force
which can be used to interpret supernovae type Ia observations, and
consequently the accelerating expansion of the Universe. This interpretation is
a pure geometric one and is a direct application of the geometrization
philosophy. Torsion energy can also be used to solve other problems of General
Relativity especially the singularity problem.


title:
Controllability and universal three-qubit quantum computation with
  trapped electron states

abstract:
  We show how to control and perform universal three-qubit quantum computation
with trapped electron quantum states. The three qubits are the electron spin,
and the first two quantum states of the cyclotron and axial harmonic
oscillators. We explicitly show how the universal gates can be performed. As an
example of a non-trivial quantum algorithm, we outline the implementation of
the Deutsch-Jozsa algorithm in this system.


title: Some geometric features of Berry's phase

abstract:
  In this letter, we elaborate on the identification and construction of the
differential geometric elements underlying Berry's phase. Berry bundles are
built generally from the physical data of the quantum system under study. We
apply this construction to typical and recently investigated systems presenting
Berry's phase to explore their geometric features.


title: Dark Matter in Gauge Mediation from Emergent Supersymmetry

abstract:
  We investigated the viability of neutralino dark matter in the gauge
mediation from emergent supersymmetry proposal. In this proposal, supersymmetry
is broken at Planck scale and consequently, the gravitino is superheavy and
completely decouples from the low energy theory. Squarks and sleptons obtain
their soft masses dominantly through gauge mediation with other mechanisms
highly suppressed. The lightest supersymmetric partner, in contrast to
traditional gauge mediation, is a neutralino which is also a dark matter
candidate. By explicit calculation of the low energy spectra, the parameter
space was constrained using the WMAP observed relic density of dark matter,
LEP2 Higgs mass bounds, collider bounds on supersymmetric partners and exotic
B-meson decays. We found that the model has intriguing hybrid features such as
a nearly gauge-mediated spectrum (the exception being the superheavy gravitino)
but with a dominant mSUGRA-like bino-stau coannihilation channel and at large
$\tan \beta$, A-resonance-like annihilation.


title:
Deformation Quantization of Relativistic Particles in Electromagnetic
  Fields

abstract:
  The Weyl-Wigner-Moyal formalism for Dirac second class constrained systems
has been proposed recently as the deformation quantization of Dirac bracket. In
this paper, after a brief review of this formalism, it is applied to the case
of the relativistic free particle. Within this context, the Stratonovich-Weyl
quantizer, Weyl correspondence, Moyal $\star$-product and Wigner function in
the constrained phase space are obtained. The recent Hamiltonian treatment for
constrained systems, whose constraints depend explicitly on time, are used to
perform the deformation quantization of the relativistic free charged particle
in an arbitrary electromagnetic background. Finally, the system consisting of a
charged particle interacting with a dynamical Maxwell field is quantized in
this context.


title:
pi-Electron theory of transverse optical excitons in semiconducting
  single-walled carbon nanotubes

abstract:
  We present a quantitative theory of optical absorption polarized transverse
to the tube axes in semiconducting single-walled carbon nanotubes. Transverse
optical absorption in semiconducting single-walled carbon nanotubes is to an
exciton state that is strongly blueshifted, relative to the two lowest
longitudinal excitons, by electron-electron interactions. The binding energy of
the transverse exciton is considerably smaller than those of the longitudinal
excitons. Electron-electron interactions also reduce the relative oscillator
strength of the transverse optical absorption. Our theoretical results are in
excellent agreement with recent experimental measurements in four chiral
nanotubes.


title:
Electromagnetic response of high-Tc superconductors -- the slave-boson
  and doped-carrier theories

abstract:
  We evaluate the doping dependence of the quasiparticle current and low
temperature superfluid density in two slave-particle theories of the tt't''J
model -- the slave-boson theory and doped-carrier theory. In the slave-boson
theory, the nodal quasiparticle current renormalization factor $\alpha$
vanishes proportionally to the zero temperature superfluid density $\rho_S(0)$;
however, we find that away from the $\rho_S(0) \to 0$ limit $\alpha$ displays a
much weaker doping dependence than $\rho_S(0)$. A similar conclusion applies to
the doped-carrier theory, which differentiates the nodal and antinodal regions
of momentum space. Due to its momentum space anisotropy, the doped-carrier
theory enhances the value of $\alpha$ in the hole doped regime, bringing it to
quantitative agreement with experiments, and reproduces the asymmetry between
hole and electron doped cuprate superconductors. Finally, we use the
doped-carrier theory to predict a specific experimental signature of local
staggered spin correlations in doped Mott insulator superconductors which, we
propose, should be observed in STM measurements of underdoped high-Tc
compounds. This experimental signature distinguishes the doped-carrier theory
from other candidate mean-field theories of high-Tc superconductors, like the
slave-boson theory and the conventional BCS theory.


title:
Variance reduction for particle filters of systems with time-scale
  separation

abstract:
  We present a particle filter construction for a system that exhibits
time-scale separation. The separation of time-scales allows two simplifications
that we exploit: i) The use of the averaging principle for the dimensional
reduction of the system needed to solve for each particle and ii) the
factorization of the transition probability which allows the
Rao-Blackwellization of the filtering step. Both simplifications can be
implemented using the coarse projective integration framework. The resulting
particle filter is faster and has smaller variance than the particle filter
based on the original system. The method is tested on a multiscale stochastic
differential equation and on a multiscale pure jump diffusion motivated by
chemical reactions.


title: A note on De Concini and Procesi's curious identity

abstract:
  We give a short, case-free and combinatorial proof of de Concini and
Procesi's formula for the volume of the simplicial cone spanned by the simple
roots of any finite root system. The argument presented here also extends their
formula to include the non-crystallographic root systems.


title:
Entanglement conditions for tripartite systems via indeterminacy
  relations

abstract:
  Based on the S-R indeterminacy relations in conjugation with the partial
transposition, we derive a class of inequalities for detecting entanglement in
several tripartite systems, including bosonic, SU(2), and SU(1,1) systems.
These inequalities are in general stronger than those based on the usual
Heisenberg relations for detecting entanglement. We also discuss the reduction
from SU(2) and SU(1,1) to bosonic systems and the generalization to
multipartite case.


title: Estimating the State of Large Spatiotemporally Chaotic Systems

abstract:
  Data assimilation refers to the process of obtaining an estimate of a
system's state using a model for the system's time evolution and a time series
of measurements that are possibly noisy and incomplete. However, for practical
reasons, the high dimensionality of large spatiotemporally chaotic systems
prevents the use of classical data assimilation techniques. Here, via numerical
computations on the paradigmatic example of large aspect ratio Rayleigh-Benard
convection, we demonstrate the applicability of a recently developed data
assimilation method designed to circumvent this difficulty. In addition, we
describe extensions of the algorithm for estimating unknown system parameters.
Our results suggest the potential usefulness of our data assimilation technique
to a broad class of situations in which there is spatiotemporally chaotic
behavior.


title:
Evolution of the Frequency of Luminous (\geq L_V*) Close Galaxy Pairs at
  z < 1.2 in the COSMOS Field

abstract:
  We measure the fraction of luminous galaxies in pairs at projected
separations of 5-20 kpc out to z=1.2 in the COSMOS field using ACS images and
photometric redshifts derived from an extensive multiwavelength dataset.
Analysis of a complete sample of 106,188 galaxies more luminous than M_V=-19.8
(~ L_V*) in the redshift range 0.1 < z < 1.2 yields 1,749 galaxy pairs. These
data are supplemented by a local z=0-0.1 value for the galaxy pair fraction
derived from the Sloan Digital Sky Survey (SDSS). After statistically
correcting the COSMOS pair sample for chance line-of-sight superpositions, the
evolution in the pair fraction is fit by a power law \propto (1+z)^{n=3.1 \pm
0.1}. If this strongly evolving pair fraction continues out to higher redshift,
~ 50% of all luminous galaxies at z ~ 2 are in close pairs. This clearly
signifies that galaxy mergers are a very significant and possibly dominant
mechanism for galaxy evolution during the epoch of galaxy formation at z=1 to
3.


title: Double Shuffle Relations of Euler Sums

abstract:
  In this paper we shall develop a theory of (extended) double shuffle
relations of Euler sums which generalizes that of multiple zeta values (see
Ihara, Kaneko and Zagier, \emph{Derivation and double shuffle relations for
multiple zeta values}. Compos. Math. \textbf{142} (2)(2006), 307--338). After
setting up the general framework we provide some numerical evidence for our two
main conjectures. At the end we shall prove the following long standing
conjecture: for every positive integer n
$$\zeta(\{3\}^n)=8^n\zeta(\{\ol2,1\}^n).$$ The main idea is to use the double
shuffle relations and the distribution relation. This particular distribution
relation doesn't follow from the double shuffle relation in general. But we
believe it does follow from the extended double shuffle relations.


title: Real interpoaltion of Sobolev spaces associated to a weight

abstract:
  We study the interpolation property of Sobolev spaces of order 1 denoted by
$W^{1}_{p,V}$, arising from Schr\"{o}dinger operators with positive potential.
We show that for $1\leq p_1<p<p_2<q_{0}$ with $p>s_0$, $W^{1}_{p,V}$ is a real
interpolation space between $W_{p_1,V}^{1}$ and $W_{p_2,V}^{1}$ on some classes
of manifolds and Lie groups. The constants $s_{0}, q_{0}$ depend on our
hypotheses.


title:
Direct cosmological simulations of the growth of black holes and
  galaxies

abstract:
  We investigate the coupled formation and evolution of galaxies and their
embedded supermassive black holes using state-of-the-art hydrodynamic
simulations of cosmological structure formation. For the first time, we
self-consistently follow the dark matter dynamics, radiative gas cooling, star
formation, as well as black hole growth and associated feedback processes,
starting directly from initial conditions appropriate for the LambdaCDM
cosmology. Our modeling of the black hole physics is based on an approach we
have developed in simulations of isolated galaxy mergers. Here we examine: (i)
the predicted global history of black hole mass assembly (ii) the evolution of
the local black hole-host mass correlations and (iii) the conditions that allow
rapid growth of the first quasars, and the properties of their hosts and
descendants today. We find a total black hole mass density in good agreement
with observational estimates. The black hole accretion rate density peaks at
lower redshift and evolves more strongly at high redshift than the star
formation rate density, but the ratio of black hole to stellar mass densities
shows only a moderate evolution at low redshifts. We find strong correlations
between black hole masses and properties of the stellar systems, agreeing well
with the measured local M_BH-sigma and M_BH -M_* relationships, but also
suggesting (dependent on the mass range) a weak evolution with redshift in the
normalization and the slope. Our simulations also produce massive black holes
at high redshift, due to extended periods of exponential growth in regions that
collapse early and exhibit strong gas inflows. These first supermassive BH
systems however are not necessarily the most massive ones today, since they are
often overtaken in growth by quasars that form later. (abridged)


title: Multi-Access MIMO Systems with Finite Rate Channel State Feedback

abstract:
  This paper characterizes the effect of finite rate channel state feedback on
the sum rate of a multi-access multiple-input multiple-output (MIMO) system. We
propose to control the users jointly, specifically, we first choose the users
jointly and then select the corresponding beamforming vectors jointly. To
quantify the sum rate, this paper introduces the composite Grassmann manifold
and the composite Grassmann matrix. By characterizing the distortion rate
function on the composite Grassmann manifold and calculating the logdet
function of a random composite Grassmann matrix, a good sum rate approximation
is derived. According to the distortion rate function on the composite
Grassmann manifold, the loss due to finite beamforming decreases exponentially
as the feedback bits on beamforming increases.


title: Bell Inequality Based on Peres-Horodecki Criterion

abstract:
  We established a physically utilizable Bell inequality based on the
Peres-Horodecki criterion. The new quadratic probabilistic Bell inequality
naturally provides us a necessary and sufficient way to test all entangled
two-qubit or qubit-qutrit states including the Werner states and the maximally
entangled mixed states.


title:
Quantization Bounds on Grassmann Manifolds of Arbitrary Dimensions and
  MIMO Communications with Feedback

abstract:
  This paper considers the quantization problem on the Grassmann manifold with
dimension n and p. The unique contribution is the derivation of a closed-form
formula for the volume of a metric ball in the Grassmann manifold when the
radius is sufficiently small. This volume formula holds for Grassmann manifolds
with arbitrary dimension n and p, while previous results are only valid for
either p=1 or a fixed p with asymptotically large n. Based on the volume
formula, the Gilbert-Varshamov and Hamming bounds for sphere packings are
obtained. Assuming a uniformly distributed source and a distortion metric based
on the squared chordal distance, tight lower and upper bounds are established
for the distortion rate tradeoff. Simulation results match the derived results.
As an application of the derived quantization bounds, the information rate of a
Multiple-Input Multiple-Output (MIMO) system with finite-rate channel-state
feedback is accurately quantified for arbitrary finite number of antennas,
while previous results are only valid for either Multiple-Input Single-Output
(MISO) systems or those with asymptotically large number of transmit antennas
but fixed number of receive antennas.


title:
On the Information Rate of MIMO Systems with Finite Rate Channel State
  Feedback and Power On/Off Strategy

abstract:
  This paper quantifies the information rate of multiple-input multiple-output
(MIMO) systems with finite rate channel state feedback and power on/off
strategy. In power on/off strategy, a beamforming vector (beam) is either
turned on (denoted by on-beam) with a constant power or turned off. We prove
that the ratio of the optimal number of on-beams and the number of antennas
converges to a constant for a given signal-to-noise ratio (SNR) when the number
of transmit and receive antennas approaches infinity simultaneously and when
beamforming is perfect. Based on this result, a near optimal strategy, i.e.,
power on/off strategy with a constant number of on-beams, is discussed. For
such a strategy, we propose the power efficiency factor to quantify the effect
of imperfect beamforming. A formula is proposed to compute the maximum power
efficiency factor achievable given a feedback rate. The information rate of the
overall MIMO system can be approximated by combining the asymptotic results and
the formula for power efficiency factor. Simulations show that this
approximation is accurate for all SNR regimes.


title: How Many Users should be Turned On in a Multi-Antenna Broadcast Channel?

abstract:
  This paper considers broadcast channels with L antennas at the base station
and m single-antenna users, where each user has perfect channel knowledge and
the base station obtains channel information through a finite rate feedback.
The key observation of this paper is that the optimal number of on-users (users
turned on), say s, is a function of signal-to-noise ratio (SNR) and other
system parameters. Towards this observation, we use asymptotic analysis to
guide the design of feedback and transmission strategies. As L, m and the
feedback rates approach infinity linearly, we derive the asymptotic optimal
feedback strategy and a realistic criterion to decide which users should be
turned on. Define the corresponding asymptotic throughput per antenna as the
spatial efficiency. It is a function of the number of on-users s, and
therefore, s should be appropriately chosen. Based on the above asymptotic
results, we also develop a scheme for a system with finite many antennas and
users. Compared with other works where s is presumed constant, our scheme
achieves a significant gain by choosing the appropriate s. Furthermore, our
analysis and scheme is valid for heterogeneous systems where different users
may have different path loss coefficients and feedback rates.


title: S_4 Flavor Symmetry Embedded into SU(3) and Lepton Masses and Mixing

abstract:
  Based on an assumption that an S_4 flavor symmetry is embedded into SU(3), a
lepton mass matrix model is investigated. A Frogatt-Nielsen type model is
assumed, and the flavor structures of the masses and mixing are caused by VEVs
of SU(2)_L-singlet scalars \phi_u and \phi_d which are nonets (8+1) of the
SU(3) flavor symmetry, and which are broken into 2+3+3' and 1 of S_4. If we
require the invariance under the transformation (\phi^{(8)},\phi^{(1)}) \to
(-\phi^{(8)},+\phi^{(1)}) for the superpotential of the nonet field
\phi^{(8+1)}, the model leads to a beautiful relation for the charged lepton
masses. The observed tribimaximal neutrino mixing is understood by assuming two
SU(3) singlet right-handed neutrinos \nu_R^{(\pm)} and an SU(3) triplet scalar
\chi.


title:
Measurements of the observed cross sections for $e^+e^- \to$ light
  hadrons at $\sqrt{s}=$ 3.773 and 3.650 GeV

abstract:
  Using the data sets of 17.3 pb$^{-1}$ collected at $\sqrt{s}=$ 3.773 GeV and
6.5 pb$^{-1}$ collected at $\sqrt{s}=$ 3.650 GeV with the BESII detector at the
BEPC collider, we have measured the observed cross sections for 18 exclusive
light hadron final states produced in $e^+e^-$ annihilation at the two energy
points.


title: Constraints on the electroweak chiral Lagrangian from the precision data

abstract:
  In the framework of the effective field theory method, we use the
experimental data and the perturbative unitarity bounds to determine the values
and uncertainty of all the 11 chiral coefficients ($\al_i, i=0, ..., 10$) of
the standard electroweak chiral Lagrangian. Up to linear terms in $\al_i$, we
provide the one-loop renormalization group equations of all the chiral
coefficients, which are calculated in the Feynman-'t Hooft gauge using the
modified minimal subtraction scheme. With the improved renormalization group
equations to sum over the logarithmic corrections, we analyze the current
experimental uncertainty of oblique correction parameters, $S(\Lambda)$ and
$T(\Lambda)$. We find that, due to the large uncertainty in the triple
gauge-boson coupling measurements, the parameter space of positive $S(\Lambda)$
for $\Lambda > 1$ TeV is still allowed by the current experimental data.
$T(\Lambda)$ tends to increase with $\Lambda$ even in the presence of the
operators that contribute to the triple and quartic gauge-boson couplings.


title: Unequal dimensional small balls and quantization on Grassmann Manifolds

abstract:
  The Grassmann manifold G_{n,p}(L) is the set of all p-dimensional planes
(through the origin) in the n-dimensional Euclidean space L^{n}, where L is
either R or C. This paper considers an unequal dimensional quantization in
which a source in G_{n,p}(L) is quantized through a code in G_{n,q}(L), where p
and q are not necessarily the same. It is different from most works in
literature where p\equiv q. The analysis for unequal dimensional quantization
is based on the volume of a metric ball in G_{n,p}(L) whose center is in
G_{n,q}(L). Our chief result is a closed-form formula for the volume of a
metric ball when the radius is sufficiently small. This volume formula holds
for Grassmann manifolds with arbitrary n, p, q and L, while previous results
pertained only to some special cases. Based on this volume formula, several
bounds are derived for the rate distortion tradeoff assuming the quantization
rate is sufficiently high. The lower and upper bounds on the distortion rate
function are asymptotically identical, and so precisely quantify the asymptotic
rate distortion tradeoff. We also show that random codes are asymptotically
optimal in the sense that they achieve the minimum achievable distortion with
probability one as n and the code rate approach infinity linearly. Finally, we
discuss some applications of the derived results to communication theory. A
geometric interpretation in the Grassmann manifold is developed for capacity
calculation of additive white Gaussian noise channel. Further, the derived
distortion rate function is beneficial to characterizing the effect of
beamforming matrix selection in multi-antenna communications.


title:
Quantum spin liquid states in the two dimensional kagome
  antiferromagnets, ZnxCu4-x(OD)6Cl2

abstract:
  A three-dimensional system of interacting spins typically develops static
long-range order when it is cooled. If the spins are quantum (S = 1/2),
however, novel quantum paramagnetic states may appear. The most highly sought
state among them is the resonating valence bond (RVB) state in which every pair
of neighboring quantum spins form entangled spin singlets (valence bonds) and
the singlets are quantum mechanically resonating amongst all the possible
highly degenerate pairing states. Here we provide experimental evidence for
such quantum paramagnetic states existing in frustrated antiferromagnets,
ZnxCu4-x(OD)6Cl2, where the S = 1/2 magnetic Cu2+ moments form layers of a
two-dimensional kagome lattice. We find that in Cu4(OD)6Cl2, where distorted
kagome planes are weakly coupled to each other, a dispersionless excitation
mode appears in the magnetic excitation spectrum below ~ 20 K, whose
characteristics resemble those of quantum spin singlets in a solid state, known
as a valence bond solid (VBS), that breaks translational symmetry. Doping
nonmagnetic Zn2+ ions reduces the distortion of the kagome lattice, and weakens
the interplane coupling but also dilutes the magnetic occupancy of the kagome
lattice. The VBS state is suppressed and for ZnCu3(OD)6Cl2 where the kagome
planes are undistorted and 90% occupied by the Cu2+ ions, the low energy spin
fluctuations in the spin liquid phase become featureless.


title:
Extension of the Adler-Bobenko-Suris classification of integrable
  lattice equations

abstract:
  The classification of lattice equations that are integrable in the sense of
higher-dimensional consistency is extended by allowing directed edges. We find
two cases that are not transformable via the 'admissible transformations' to
the lattice equations in the existing classification.


title:
Tunable Ti:Al2O3 oscillator optimized for high-repetition-rate and short
  pulses

abstract:
  A laser was designed and constructed with the goal of producing ultra-short
pulses at a high repetition rate as needed for certain applications of
multi-photon microscopy. With pure prism-based dispersion compensation
repetition rates of up to 270MHz were achieved. The laser operates with hard-
and soft-aperturing at the third (diverging output) and the first (parallel
output) stability limits, respectively. At the third stability limit we found a
pulse width of 27fs (FWHM) at 800nm central wavelength. At the first stability
limit pulse widths of 23-40fs with tunability from 780nm to 920nm were reached.


title:
Enhanced Beam Deflection in Bent Crystals using Multiple Volume
  Reflection

abstract:
  This paper presents simulations of the trajectories of high-energy ions
through several bent crystal layers. At certain layer alignments volume
reflection occurs from each layer and the resultant multiple volume reflection
angle is correspondingly increased, along with the range of entrance angles
over which ions undergo volume reflection. Another feature is that the range of
entrance angles for which bent crystal channeling occurs is also increased in
passing through several bent layers. The use of several bent crystal layers to
produce multiple volume reflection provides an alternative approach to the
design of a space shield or radiation protection at accelerators based on bent
crystals.


title:
Studies of Thermally Unstable Accretion Disks around Black Holes with
  Adaptive Pseudo-Spectral Domain Decomposition Method I. Limit-Cycle Behavior
  in the Case of Moderate Viscosity

abstract:
  We present a numerical method for spatially 1.5-dimensional and
time-dependent studies of accretion disks around black holes, that is
originated from a combination of the standard pseudo-spectral method and the
adaptive domain decomposition method existing in the literature, but with a
number of improvements in both the numerical and physical senses. In
particular, we introduce a new treatment for the connection at the interfaces
of decomposed subdomains, construct an adaptive function for the mapping
between the Chebyshev-Gauss-Lobatto collocation points and the physical
collocation points in each subdomain, and modify the over-simplified
1-dimensional basic equations of accretion flows to account for the effects of
viscous stresses in both the azimuthal and radial directions. Our method is
verified by reproducing the best results obtained previously by Szuszkiewicz &
Miller on the limit-cycle behavior of thermally unstable accretion disks with
moderate viscosity. A new finding is that, according to our computations, the
Bernoulli function of the matter in such disks is always and everywhere
negative, so that outflows are unlikely to originate from these disks. We are
encouraged to study the more difficult case of thermally unstable accretion
disks with strong viscosity, and wish to report our results in a subsequent
paper.


title: The weighted complexity and the determinant functions of graphs

abstract:
  The complexity of a graph can be obtained as a derivative of a variation of
the zeta function or a partial derivative of its generalized characteristic
polynomial evaluated at a point [\textit{J. Combin. Theory Ser. B}, 74 (1998),
pp. 408--410]. A similar result for the weighted complexity of weighted graphs
was found using a determinant function [\textit{J. Combin. Theory Ser. B}, 89
(2003), pp. 17--26]. In this paper, we consider the determinant function of two
variables and discover a condition that the weighted complexity of a weighted
graph is a partial derivative of the determinant function evaluated at a point.
Consequently, we simply obtain the previous results and disclose a new formula
for the Bartholdi zeta function. We also consider a new weighted complexity,
for which the weights of spanning trees are taken as the sum of weights of
edges in the tree, and find a similar formula for this new weighted complexity.
As an application, we compute the weighted complexities of the product of the
complete graphs.


title: Remarks on regularity conditions of the Navier-Stokes equations

abstract:
  Let $v$ and $\o$ be the velocity and the vorticity of the a suitable weak
solution of the 3D Navier-Stokes equations in a space-time domain containing
$z_0 =(x_0, t_0)$, and $Q_{z_0, r} =B_{x_0, r}\times (t_0-r^2, t_0)$ be a
parabolic cylinder in the domain. We show that if $v\times \frac{\o}{|\o|}\in
L^{\gamma, \alpha}_{x,t} (Q_{z_0, r})$ or ${\o}\times \frac{v}{|v|}\in
L^{\gamma, \alpha}_{x,t} (Q_{z_0, r})$, where $L^{\gamma, \alpha}_{x,t}$
denotes the Serrin type of class, then $z_0$ is a regular point for $v$. This
refines previous local regularity criteria for the suitable weak solutions.


title: An accurate model for genetic hitch-hiking

abstract:
  We suggest a simple deterministic approximation for the growth of the
favoured-allele frequency during a selective sweep. Using this approximation we
introduce an accurate model for genetic hitch-hiking. Only when Ns < 10 (N is
the population size and s denotes the selection coefficient), are discrepancies
between our approximation and direct numerical simulations of a Moran model
noticeable. Our model describes the gene genealogies of a contiguous segment of
neutral loci close to the selected one, and it does not assume that the
selective sweep happens instantaneously. This enables us to compute SNP
distributions on the neutral segment without bias.


title:
On Uniqueness of Boundary Blow-up Solutions of a Class of Nonlinear
  Elliptic Equations

abstract:
  We study boundary blow-up solutions of semilinear elliptic equations
$Lu=u_+^p$ with $p>1$, or $Lu=e^{au}$ with $a>0$, where $L$ is a second order
elliptic operator with measurable coefficients. Several uniqueness theorems and
an existence theorem are obtained.


title:
Effect of superlattice modulation of electronic parameters on
  superconducting density of states in cuprate superconductors

abstract:
  Recent scanning tunneling microscopy on BSCCO 2212 has revealed a substantial
spatial supermodulation of the energy gap in the superconducting state. We
propose that this gap modulation is due to the superlattice modulations of the
atoms in the structure, and hence the parameters in a microscopic model of the
CuO2 plane. The gap modulation is estimated using renormalized mean field
theory for a t-t'-J model on a superlattice. The results compare well with
experiment.


title:
Semiclassical corrections to the Einstein equation and Induced Matter
  Theory

abstract:
  The induced Einstein equation on a perturbed brane in the Induced Matter
Theory is re-analyzed. We indicate that in a conformally flat background, the
local quantum corrections to the Einstein equation can be obtained via the IMT.
Using the FRW metric as the 4D gravitational model, we show that the classical
fluctuations of the brane may be related to the quantum corrections to the
classical Einstein equation. In other words, the induced Einstein equation on
the perturbed brane correspond with the semiclassical Einstein equation.


title: |V_{ub}| from the Spectrum of B->pi e nu

abstract:
  I discuss the results for $|V_{ub}|f_+(0)$ and $|V_{ub}|$ obtained from the
spectrum of $B\to\pi e \nu$ and the form factor $f_+(q^2)$ from QCD sum rules
on the light-cone and unquenched lattice calculations; the shape of $f_+(q^2)$
is fixed from experimental data.


title: Self-reptation and slow topological time scale of knotted polymers

abstract:
  We investigate the Rouse dynamics of a flexible ring polymer with a prime
knot. Within a Monte Carlo approach, we locate the knot, follow its diffusion,
and observe the fluctuations of its length. We characterise a topological time
scale, and show that it is related to a self-reptation of the knotted region.
The associated dynamical exponent, $z_T=2.32\pm.1$, can be related to that of
the equilibrium knot length distribution and determines the behaviour of
several dynamical quantities.


title:
3D Simulations of Electromagnetic Fields in Nanostructures using the
  Time-Harmonic Finite-Element Method

abstract:
  Rigorous computer simulations of propagating electromagnetic fields have
become an important tool for optical metrology and optics design of
nanostructured components. As has been shown in previous benchmarks some of the
presently used methods suffer from low convergence rates and/or low accuracy of
the results and exhibit very long computation times which makes application to
extended 2D layout patterns impractical. We address 3D simulation tasks by
using a finite-element solver which has been shown to be superior to competing
methods by several orders of magnitude in accuracy and computational time for
typical microlithography simulations. We report on the current status of the
solver, incorporating higher order edge elements, adaptive refinement methods,
and fast solution algorithms. Further, we investigate the performance of the
solver in the 3D simulation project of light diffraction off an alternating
phase-shift contact-hole mask.


title:
Construction of maximal unramified p-extensions with prescribed Galois
  groups

abstract:
  In the present paper, we shall show that for any prime number p, every finite
p-group occurs as the Galois Group of the maximal unramified p-extension over a
certain number field of finite degree.
  We shall also show that for any given pro-p-group G with countably many
generators, there exists a number field (not necessary of finite degree) whose
maximal unramified p-extension has Galois group isomorphic to G. This means
that the set of the isomorphism classes of the Galois groups of the maximal
unramified p-extensions over the number fields (including of infinite degree)
is precisely equal to that of all the pro-p-groups with countably many
generators.


title: $p$-Adic Haar multiresolution analysis and pseudo-differential operators

abstract:
  The notion of {\em $p$-adic multiresolution analysis (MRA)} is introduced. We
discuss a ``natural'' refinement equation whose solution (a refinable function)
is the characteristic function of the unit disc. This equation reflects the
fact that the characteristic function of the unit disc is a sum of $p$
characteristic functions of mutually disjoint discs of radius $p^{-1}$. This
refinement equation generates a MRA. The case $p=2$ is studied in detail. Our
MRA is a 2-adic analog of the real Haar MRA. But in contrast to the real
setting, the refinable function generating our Haar MRA is 1-periodic, which
never holds for real refinable functions. This fact implies that there exist
infinity many different 2-adic orthonormal wavelet bases in ${\cL}^2(\bQ_2)$
generated by the same Haar MRA. All of these bases are described. We also
constructed multidimensional 2-adic Haar orthonormal bases for
${\cL}^2(\bQ_2^n)$ by means of the tensor product of one-dimensional MRAs. A
criterion for a multidimensional $p$-adic wavelet to be an eigenfunction for a
pseudo-differential operator is derived. We proved also that these wavelets are
eigenfunctions of the Taibleson multidimensional fractional operator. These
facts create the necessary prerequisites for intensive using our bases in
applications.


title:
Anisotropic spin splitting of the electron ground state in InAs quantum
  dots

abstract:
  Photoinduced circular dichroism experiments in an oblique magnetic field
allow measurements of Larmor precession frequencies, and so give a precise
determination of the electron Lande g factor and its anisotropy in
self-assembled InAs/GaAs quantum dots emitting at 1.32 eV. In good agreement
with recent theoretical results, we measure g perp= 0.397 +_ 0.003 and g par =
0.18 +- 0.02.


title: Phase resolved measurements of stimulated emission

abstract:
  The development of the semiconductor quantum cascade laser (QCL) [1] has
enabled bright coherent sources operating at frequencies between the optical
(>100 THz) and electronic (<0.5 THz) ranges opening this frequency region for
fundamental science investigations [2-5] as well as for applications [6].
However, detailed information about the internal processes in QCLs and their
ultrafast dynamics are needed for their further development towards high output
power, longer wavelengths and stable pulsed operation. We introduce a novel
approach to study the gain and dynamics of a terahertz (THz) QCL [7] using
phase resolved measurements of the stimulated emission. This is enabled by
direct recording of the emitted electric field with <100 fs time resolution.
For the case of the THz QCL we demonstrate the validity of the quantum
mechanical description of the laser. We show for the first time the real
bandwidth of the terahertz gain medium, the current dependence of this gain,
and the losses associated with the wave propagation in the laser waveguide.


title:
On the tuning of a wave-energy driven oscillating-water-column seawater
  pump to polychromatic waves

abstract:
  Performance of wave-energy devices of the oscillating water column (OWC) type
is greatly enhanced when a resonant condition with the forcing waves is
maintained. The natural frequency of such systems can in general be tuned to
resonate with a given wave forcing frequency. In this paper we address the
tuning of an OWC sea-water pump to polychromatic waves. We report results of
wave tank experiments, which were conducted with a scale model of the pump.
Also, a numerical solution for the pump equations, which were proven in
previous work to successfully describe its behavior when driven by
monochromatic waves, is tested with various polychromatic wave spectra. Results
of the numerical model forced by the wave trains measured in the wave tank
experiments are used to develop a tuning criterion for the sea-water pump.


title: Local Sentences and Mahlo Cardinals

abstract:
  Local sentences were introduced by J.-P. Ressayre who proved certain
remarkable stretching theorems establishing the equivalence between the
existence of finite models for these sentences and the existence of some
infinite well ordered models. Two of these stretching theorems were only proved
under certain large cardinal axioms but the question of their exact
(consistency) strength was left open in [O. Finkel and J.-P. Ressayre,
Stretchings, Journal of Symbolic Logic, Volume 61 (2), 1996, p. 563-585 ].
Here, we solve this problem, using a combinatorial result of J. H. Schmerl. In
fact, we show that the stretching principles are equivalent to the existence of
n-Mahlo cardinals for appropriate integers n. This is done by proving first
that for each integer n, there is a local sentence phi_n which has well ordered
models of order type alpha, for every infinite ordinal alpha > omega which is
not an n-Mahlo cardinal.


title: Time evolution of T_{\mu\nu} and the cosmological constant problem

abstract:
  We study the cosmic time evolution of an effective quantum field theory
energy-momentum tensor T_{\mu\nu} and show that, as a consequence of the
effective nature of the theory, the structure of T_{\mu\nu} is such that the
vacuum energy decreases with time. We find that the zero point energy at
present time is washed out by the cosmological evolution. The implications of
this finding for the cosmological constant problem are investigated.


title:
The anticenter old open cluster NGC 1883: radial velocity and
  metallicity

abstract:
  Having already reported on the first photometric study of the
intermediate-age open cluster NGC 1883 (Carraro et al. 2003), we present in
this paper the first spectroscopic multi-epoch investigation of a sample of
evolved stars in the same cluster. The aim is to derive the cluster membership,
velocity and metallicity, and discuss recent claims in the literature (Tadross
2005) that NGC 1883 is as metal poor as globular clusters in the Halo. Besides,
being one of the few outer Galactic disk intermediate-age open clusters known
so far, it is an ideal target to improve our knowledge of the Galactic disk
radial abundance gradient, that is a basic ingredient for any chemical
evolution model of the Milky Way. The new data we obtained allow us to put NGC
1883's basic parameters more reliable. We find that the cluster has a mean
metallicity of [Fe/H] = -0.20$\pm$0.22, from which we infer an age
(650$^{+70}_{-70}$ Myr) close to the Hyades one and a Galactocentric distance
of 12.3$^{+0.4}_{-0.2}$ kpc. The metal abundance, kinematics, and position make
NGC 1883 a genuine outer disk intermediate-age open cluster. We confirm that in
the outer Galactic disk the abundance gradient is shallower than in the solar
vicinity.


title: Withrawn paper

abstract:
  This paper has been withdrawn by the authors due to some fatal errors in the
analysis.


title: On randomized stopping

abstract:
  A general result on the method of randomized stopping is proved. It is
applied to optimal stopping of controlled diffusion processes with unbounded
coefficients to reduce it to an optimal control problem without stopping. This
is motivated by recent results of Krylov on numerical solutions to the Bellman
equation.


title: Charge-Transfer Excitations in One-Dimensional Dimerized Mott Insulators

abstract:
  We investigate the optical properties of one-dimensional (1D) dimerized Mott
insulators using the 1D dimerized extended Hubbard model. Numerical
calculations and a perturbative analysis from the decoupled-dimer limit clarify
that there are three relevant classes of charge-transfer (CT) states generated
by photoexcitation: interdimer CT unbound states, interdimer CT exciton states,
and intradimer CT exciton states. This classification is applied to
understanding the optical properties of an organic molecular material,
1,3,5-trithia-2,4,6-triazapentalenyl (TTTA), which is known for its
photoinduced transition from the dimerized spin-singlet phase to the regular
paramagnetic phase. We conclude that the lowest photoexcited state of TTTA is
the interdimer CT exciton state and the second lowest state is the intradimer
CT exciton state.


title: Inter-network regions of the Sun at millimetre wavelengths

abstract:
  The continuum intensity at wavelengths around 1 mm provides an excellent way
to probe the solar chromosphere. Future high-resolution millimetre arrays, such
as the Atacama Large Millimeter Array (ALMA), will thus produce valuable input
for the ongoing controversy on the thermal structure and the dynamics of this
layer. Synthetic brightness temperature maps are calculated on basis of
three-dimensional radiation (magneto-)hydrodynamic (MHD) simulations. While the
millimetre continuum at 0.3mm originates mainly from the upper photosphere, the
longer wavelengths considered here map the low and middle chromosphere. The
effective formation height increases generally with wavelength and also from
disk-centre towards the solar limb. The average intensity contribution
functions are usually rather broad and in some cases they are even
double-peaked as there are contributions from hot shock waves and cool
post-shock regions in the model chromosphere. Taking into account the
deviations from ionisation equilibrium for hydrogen gives a less strong
variation of the electron density and with it of the optical depth. The result
is a narrower formation height range. The average brightness temperature
increases with wavelength and towards the limb. The relative contrast depends
on wavelength in the same way as the average intensity but decreases towards
the limb. The dependence of the brightness temperature distribution on
wavelength and disk-position can be explained with the differences in formation
height and the variation of temperature fluctuations with height in the model
atmospheres.


title: Fuzzy and Multilayer Perceptron for Evaluation of HV Bushings

abstract:
  The work proposes the application of fuzzy set theory (FST) to diagnose the
condition of high voltage bushings. The diagnosis uses dissolved gas analysis
(DGA) data from bushings based on IEC60599 and IEEE C57-104 criteria for oil
impregnated paper (OIP) bushings. FST and neural networks are compared in terms
of accuracy and computational efficiency. Both FST and NN simulations were able
to diagnose the bushings condition with 10% error. By using fuzzy theory, the
maintenance department can classify bushings and know the extent of degradation
in the component.


title: Near-Extreme Black Holes and the Universal Relaxation Bound

abstract:
  A fundamental bound on the relaxation time \tau of a perturbed
thermodynamical system has recently been derived, \tau \geq \hbar/\pi T, where
$T$ is the system's temperature. We demonstrate analytically that black holes
saturate this bound in the extremal limit and for large values of the azimuthal
number m of the perturbation field.


title: A Study in a Hybrid Centralised-Swarm Agent Community

abstract:
  This paper describes a systems architecture for a hybrid Centralised/Swarm
based multi-agent system. The issue of local goal assignment for agents is
investigated through the use of a global agent which teaches the agents
responses to given situations. We implement a test problem in the form of a
Pursuit game, where the Multi-Agent system is a set of captor agents. The
agents learn solutions to certain board positions from the global agent if they
are unable to find a solution. The captor agents learn through the use of
multi-layer perceptron neural networks. The global agent is able to solve board
positions through the use of a Genetic Algorithm. The cooperation between
agents and the results of the simulation are discussed here. .


title:
Evolution of Magnetic Fields in Freely Decaying Magnetohydrodynamic
  Turbulence

abstract:
  We study the evolution of magnetic fields in freely decaying
magnetohydrodynamic turbulence. By quasi-linearizing the Navier-Stokes
equation, we solve analytically the induction equation in quasi-normal
approximation. We find that, if the magnetic field is not helical, the magnetic
energy and correlation length evolve in time respectively as E_B \propto
t^{-2(1+p)/(3+p)} and \xi_B \propto t^{2/(3+p)}, where p is the index of
initial power-law spectrum. In the helical case, the magnetic helicity is an
almost conserved quantity and forces the magnetic energy and correlation length
to scale as E_B \propto (log t)^{1/3} t^{-2/3} and \xi_B \propto (log t)^{-1/3}
t^{2/3}.


title: Stability of associated primes of monomial ideals

abstract:
  Let $I$ be a monomial ideal of a polynomial ring $R$. In this paper we
determine a number $B$ such that $\Ass (I^n/I^{n+1}) = \Ass (I^{B}/I^{B+1})$
for all $n\geq B$.


title: On-Line Condition Monitoring using Computational Intelligence

abstract:
  This paper presents bushing condition monitoring frameworks that use
multi-layer perceptrons (MLP), radial basis functions (RBF) and support vector
machines (SVM) classifiers. The first level of the framework determines if the
bushing is faulty or not while the second level determines the type of fault.
The diagnostic gases in the bushings are analyzed using the dissolve gas
analysis. MLP gives superior performance in terms of accuracy and training time
than SVM and RBF. In addition, an on-line bushing condition monitoring
approach, which is able to adapt to newly acquired data are introduced. This
approach is able to accommodate new classes that are introduced by incoming
data and is implemented using an incremental learning algorithm that uses MLP.
The testing results improved from 67.5% to 95.8% as new data were introduced
and the testing results improved from 60% to 95.3% as new conditions were
introduced. On average the confidence value of the framework on its decision
was 0.92.


title: Multidimensional fluid motions with planar waves

abstract:
  In the classical one-dimensional solution of fluid dynamics equations all
unknown functions depend only on time t and Cartesian coordinate x. Although
fluid spreads in all directions (velocity vector has three components) the
whole picture of motion is relatively simple: trajectory of one fluid particle
from plane x=const completely determines motion of the whole plane. Basing on
the symmetry analysis of differential equations we propose generalization of
this solution allowing movements in different directions of fluid particles
belonging to plane x=const. At that, all functions but an angle determining the
direction of particle's motion depend on t and x only, whereas the angle
depends on all coordinates. In this solution the whole picture of motion
superposes from identical trajectories placed under different angles in 3D
space. Orientations of the trajectories are restricted by a finite relation
possessing functional arbitrariness. The solution describes three-dimensional
nonlinear processes and singularities in infinitely conducting plasma, gas or
incompressible liquid.


title: Readout of solid-state charge qubits using a single-electron pump

abstract:
  A major difficulty in realizing a solid-state quantum computer is the
reliable measurement of the states of the quantum registers. In this paper, we
propose an efficient readout scheme making use of the resonant tunneling of a
ballistic electron produced by a single electron pump. We treat the measurement
interaction in detail by modeling the full spatial configuration, and show that
for pumped electrons with suitably chosen energy the transmission coefficient
is very sensitive to the qubit state. We further show that by using a short
sequence of pumping events, coupled with a simple feedback control procedure,
the qubit can be measured with high accuracy.


title: TrustMIX: Trustworthy MIX for Energy Saving in Sensor Networks

abstract:
  MIX has recently been proposed as a new sensor scheme with better energy
management for data-gathering in Wireless Sensor Networks. However, it is not
known how it performs when some of the sensors carry out sinkhole attacks. In
this paper, we propose a variant of MIX with adjunct computational trust
management to limit the impact of such sinkhole attacks. We evaluate how MIX
resists sinkhole attacks with and without computational trust management. The
main result of this paper is to find that MIX is very vulnerable to sinkhole
attacks but that the adjunct trust management efficiently reduces the impact of
such attacks while preserving the main feature of MIX: increased lifetime of
the network.


title: New Physics with Tagged Forward Protons at the LHC

abstract:
  The addition of forward proton detectors to LHC experiments will
significantly enlarge the potential for studying New Physics. A topical example
is Higgs production by the central exclusive diffractive process, pp -> p+H+p.
We discuss the exclusive production of Higgs bosons in both the SM and MSSM.
Special attention is paid to the backgrounds to the H -> bbbar signal.


title: On the Connection between Mass Loss and Evolution of C-rich AGB stars

abstract:
  The mass loss properties of carbon AGB stars are not very well constrained at
present. A variety of empirical or theoretical formulae with different
parameterisations are available in the literature and the agreement between
them is anything but good. These simple mass loss prescriptions are nontheless
used in many models of stellar evolution without much consideration of their
applicability in various cases. We present here an on-going project aiming at a
better description of the mass loss, that could be used to improve stellar
evolution models -- especially the evolution during the TP-AGB phase. As a
first step, we have considered the mass loss evolution during a He-shell flash.
Using stellar parameters sampled from a stellar evolutionary track, we have
computed the time evolution of the atmospheric layers and wind acceleration
region during a flash event with detailed frequency-dependent
radiation-hydrodynamical models including dust formation. Based on these
results, we have also simulated the subsequent long-term dynamical evolution of
the circumstellar envelope (CSE), including the formation of a detached shell.
We find that existing simple mass loss prescriptions imply different mass loss
evolutions compared with our model. The second step of the project deals with
the dependence of mass loss on the basic stellar parameters. At the moment we
are computing a large grid of wind models for C-rich AGB stars. Preliminary
results show that simple parameterisations are difficult to obtain in certain
regions of the parameter space considered, due to strong non-linearities in the
wind mechanism.


title: On The Recently Discovered Pulsations From RX J1856.5-3754

abstract:
  An explanation of the recently discovered 7 s pulsations from the isolated
neutron star RX J1856.5-3754 is presented. It is assumed that the real spin
period of this source is $\approx1$ s, whereas the observed spin-modulation is
caused by the presence of a nearly transverse, very low frequency drift waves
in the pulsar magnetosphere. It is supposed that the period of the drift wave
is equal to a recently observed one. The simulated lightcurve is plotted, the
angular parameters are defined and the value of the pulsed fraction of only
$\sim 1.2%$ is explained.


title: Johnson noise and the thermal Casimir effect

abstract:
  We study the thermal interaction between two nearby thin metallic wires, at
finite temperature. It is shown that the Johnson currents in the wires give
rise, via inductive coupling, to a repulsive force between them. This thermal
interaction exhibits all the puzzling features found recently in the thermal
Casimir effect for lossy metallic plates, suggesting that the physical origin
of the difficulties encountered in the Casimir problem resides in the inductive
coupling between the Johnson currents inside the plates. We show that in our
simple model all puzzles are resolved if account is taken of capacitive effects
associated with the end points of the wires. Our findings suggest that
capacitive finite-size effects may play an important role in the resolution of
the analogous problems met in the thermal Casimir effect.


title:
Statistical Mechanics of Nonlinear On-line Learning for Ensemble
  Teachers

abstract:
  We analyze the generalization performance of a student in a model composed of
nonlinear perceptrons: a true teacher, ensemble teachers, and the student. We
calculate the generalization error of the student analytically or numerically
using statistical mechanics in the framework of on-line learning. We treat two
well-known learning rules: Hebbian learning and perceptron learning. As a
result, it is proven that the nonlinear model shows qualitatively different
behaviors from the linear model. Moreover, it is clarified that Hebbian
learning and perceptron learning show qualitatively different behaviors from
each other. In Hebbian learning, we can analytically obtain the solutions. In
this case, the generalization error monotonically decreases. The steady value
of the generalization error is independent of the learning rate. The larger the
number of teachers is and the more variety the ensemble teachers have, the
smaller the generalization error is. In perceptron learning, we have to
numerically obtain the solutions. In this case, the dynamical behaviors of the
generalization error are non-monotonic. The smaller the learning rate is, the
larger the number of teachers is; and the more variety the ensemble teachers
have, the smaller the minimum value of the generalization error is.


title:
Coherence Properties of a Bose-Einstein Condensate in an Optical
  Superlattice

abstract:
  We study the effect of a one dimensional optical superlattice on the
superfluid fraction, number squeezing, dynamic structure factor and the
quasi-momentum distribution of the Mott-insulator. We show that due to the
secondary lattice,there is a decrease in the superfluid fraction and the number
fluctuation. The dynamic structure factor which can be measured by Bragg
spectroscopy is also suppressed due to the addition of the secondary lattice.
The visibility of the interference pattern (the quasi-momentum distribution)of
the Mott-insulator is found to decrease due to the presence of the secondary
lattice. Our results have important implications in atom interferometry and
quantum computation in optical lattices.


title:
The Localization Length of Stationary States in the Nonlinear
  Schreodinger Equation

abstract:
  For the nonlinear Schreodinger equation (NLSE), in presence of disorder,
exponentially localized stationary states are found. In the present Letter it
is demonstrated analytically that the localization length is typically
independent of the strength of the nonlinearity and is identical to the one
found for the corresponding linear equation. The analysis makes use of the
correspondence between the stationary NLSE and the Langevin equation as well as
of the resulting Fokker-Planck equation. The calculations are performed for the
``white noise'' random potential and an exact expression for the exponential
growth of the eigenstates is obtained analytically. It is argued that the main
conclusions are robust.


title: Cadlag curves of SLE driven by Levy processes

abstract:
  Schramm Loewner Evolutions (SLE) are random increasing hulls defined through
the Loewner equation driven by Brownian motion. It is known that the increasing
hulls are generated by continuous curves. When the driving process is of the
form \sqrt{\kappa} B+\theta^{1/\alpha}S for a Brownian motion B and a symmetric
\alpha-stable process S with \kappa not equal to 4 and 8, we prove that the
corresponding increasing hulls are generated by Cadlag curves.


title: Diamagnetism in disordered graphene

abstract:
  The orbital magnetism is studied in graphene monolayer within the effective
mass approximation. In models of short-range and long-range disorder, the
magnetization is calculated with self-consistent Born approximation. In the
zero-field limit, the susceptibility becomes highly diamagnetic around zero
energy, while it has a long tail proportional to the inverse of the Fermi
energy. We demonstrated how the magnetic oscillation vanishes and converges to
the susceptibility, on going from a strong-field regime to zero-field. The
behavior at zero energy is shown to be highly singular.


title: The orbifold transform and its applications

abstract:
  We discuss the notion of the orbifold transform, and illustrate it on simple
examples. The basic properties of the transform are presented, including
transitivity and the exponential formula for symmetric products. The connection
with the theory of permutation orbifolds is addressed, and the general results
illustrated on the example of torus partition functions.


title:
Finite temperature effects in light scattering off Cooper-paired Fermi
  atoms

abstract:
  We study stimulated light scattering off a superfluid Fermi gas of atoms at
finite temperature. We derive response function that takes into account vertex
correction due to final state interactions; and analyze finite temperature
effects on collective and quasiparticle excitations of a uniform superfluid
Fermi gas. Light polarization is shown to play an important role in
excitations. Our results suggest that it is possible to excite
Bogoliubov-Anderson phonon at a large scattering length by light scattering.


title: A Curvature Principle for the interaction between universes

abstract:
  We propose a Curvature Principle to describe the dynamics of interacting
universes in a multi-universe scenario and show, in the context of a simplified
model, how interaction drives the cosmological constant of one of the universes
toward a vanishingly small value. We also conjecture on how the proposed
Curvature Principle suggests a solution for the entropy paradox of a universe
where the cosmological constant vanishes.


title: A New Fracture Function Approach to QCD Initial State Radiation

abstract:
  Ordinary fracture functions, describing hadrons production in the deep
inelastic scattering target fragmentation region, are generalized to account
for the production of hadrons in arbitrary number, thus offering a renewed
framework for dealing with QCD initial state radiation. We also propose a new
jet-like observable which measures beam remnants and low-$p_{\perp}$ scattering
fragments and derive its QCD evolution equations by using Jet Calculus.
Possible implications for semi-inclusive deep inelastic scattering and
hadron-hadron reactions are shortly discussed.


title:
Destructed double-layer and ionic charge separation near the oil-water
  interface

abstract:
  We study suspensions of hydrophobic charged colloidal spheres dispersed in a
demixed oil-water mixture by means of a modified Poisson-Boltzmann theory,
taking into account image charge effects and partitioning of the monovalent
ions. We find that the ion's aversion for oil can destroy the double layers of
the oil-dispersed colloids. This affects the salt-concentration dependence of
the colloidal adsorption to the oil-water interface qualitatively. The theory
also predicts a narrow range of the oil-dielectric constant in which
micron-sized water-in-oil droplets acquire enough charge to crystallize at
volume fractions as small as $\sim 10^{-3}$ in the absence of colloids. These
findings explain recent observations [M.E. Leunissen {\em et al.}, Proc. Nat.
Ac. Sci {\bf 104}, 2585 (2007)].


title: On the realignment criterion and beyond

abstract: The content of this paper is now available as part of arXiv:0802.2019


title:
Search for Neutral Higgs Boson Production in the Decay h to tau(mu) tau
  with the D0 Detector

abstract:
  A search for the production of neutral Higgs bosons decaying into tau tau
final states is presented. One of the two tau leptons is required to decay into
a muon. The data were collected by the D0 detector and correspond to an
integrated luminosity of about 1.0 fb-1. No excess is observed above the
expected backgrounds. The results are interpreted in the Minimal Supersymmetric
Standard Model. In the mass range 90<mA<200 GeV values of tan(beta) larger than
40-60 are excluded for the no-mixing and the mhmax benchmark scenarios.


title:
Tracing mixing in stars: new beryllium observations of the open clusters
  NGC 2516, Hyades, and M67

abstract:
  Determinations of beryllium abundance in stars, together with lithium,
provide a key tool to investigate the so far poorly understood extra-mixing
processes at work in stellar interiors. We measured Be in three open
clusters,complementing existing Be surveys, and aiming at gathering a more
complete empirical scenario of the evolution of Be as a function of stellar age
and temperature. Specifically, we analyzed VLT/UVES spectra of members of NGC
2516, the Hyades, and M 67 to determine their Be and Li abundances. In the
first two clusters we focused on stars cooler than 5400 K, while the M 67
sample includes stars warmer than 6150 K, as well as two subgiants and two blue
stragglers. We also computed the evolution of Be for a 0.9 Mo star based on
standard evolutionary models. We find different emprical behaviours for stars
in different temperature bins and ages. Stars warmer than 6150 K show Be
depletion and follow a Be vs. Li correlation while Be is undepleted in stars in
the ~6150-5600 K range. NGC 2516 members cooler than 5400 K have not depleted
any Be, but older Hyades of similar temperature do show some depletion. Be is
severely depleted in the subgiants and blue stragglers. The results for warm
stars are in agreement with previous studies, supporting the hypothesis that
mixing in this temperature regime is driven by rotation. The same holds for the
two subgiants that have evolved from the "Li gap". This mechanism is instead
not the dominant one for solar-type stars. We show that Be depletion of cool
Hyades cannot simply be explained by the effect of increasing depth of the
convective zone. Finally, the different Be content of the two blue stragglers
suggests that they have formed by two different processes (i.e., collisions vs.
binary merging).


title:
Boundary Conformal Field Theory and Ribbon Graphs: a tool for
  open/closed string dualities

abstract:
  We construct and fully characterize a scalar boundary conformal field theory
on a triangulated Riemann surface. The results are analyzed from a string
theory perspective as tools to deal with open/closed string dualities.


title: Extremal Presentations for Classical Lie Algebras

abstract:
  The long-root elements in Lie algebras of Chevalley type have been well
studied and can be characterized as extremal elements, that is, elements $x$
such that the image of $(\ad x)^2$ lies in the subspace spanned by $x$. In this
paper, assuming an algebraically closed base field of characteristic not 2, we
find presentations of the Lie algebras of classical Chevalley type by means of
minimal sets of extremal generators. The relations are described by simple
graphs on the sets. For example, for $C_n$ the graph is a path of length $2n$,
and for $A_n$ the graph is the triangle connected to a path of length $n-3$.


title: Gamma Rays frim the Galactic Centre

abstract:
  Recent results from the HESS gamma ray telescope have shown the presence of
both a diffuse, extended, flux of gamma rays above ~0.4 TeV and discrete
sources in and near the Galactic Centre. Here, we put forward a possible
explanation in terms of the diffusion of cosmic ray protons from a succession
of supernova remnants (SNR) in the SgrA* region of the Galaxy plus a
contribution from SNR in the rest of the Galactic Centre Region, to be called
the Galactic Centre Ridge (GCR). Protons are favoured over electrons because
the mG magnetic fields in the Region will attenuate energetic electrons
severely. Prominent features are the need for 'anomalous diffusion' of the
protons in the whole region and the adoption of low efficiency for SNR
acceleration in the high density regions. The latter is related by us to the
well-known low 'cosmic ray gradient' in the Galaxy. A corroborating feature is
the close correlation of inferred cosmic ray intensity with the smoothed
intensity of 5 GHZ radio radiation. We attribute this to the presence of the
SNR in the GCR.


title:
Improved position measurement of nano electromechanical systems using
  cross correlations

abstract:
  We consider position measurements using the cross-correlated output of two
tunnel junction position detectors. Using a fully quantum treatment, we
calculate the equation of motion for the density matrix of the coupled
detector-detector-mechanical oscillator system. After discussing the presence
of a bound on the peak-to-background ratio in a position measurement using a
single detector, we show how one can use detector cross correlations to
overcome this bound. We analyze two different possible experimental
realizations of the cross correlation measurement and show that in both cases
the maximum cross-correlated output is obtained when using twin detectors and
applying equal bias to each tunnel junction. Furthermore, we show how the
double-detector setup can be exploited to drastically reduce the added
displacement noise of the oscillator.