title:
Reducing the positional modulation of NbO6-octahedra in SrxBa1-xNb2O6 by
  increasing the Barium content: A single crystal neutron diffraction study at
  ambient temperature for x=0.61 and x=0.34

abstract:
  We report on the influence of the Barium content on the modulation amplitude
in SrxBa1-xNb2O6 compounds by comparing Sr0.61Ba0.39Nb2O6 (SBN61) and
Sr0.34Ba0.66Nb2O6 (SBN34). Our single crystal neutron diffraction results
demonstrate that the amplitude of the positional modulation of the NbO6
octahedra is reduced with increasing barium content, indicating that the origin
of the modulation is the partial occupation of the pentagonal channels by Sr
and Ba atoms. By increasing the Sr content the bigger Ba atoms are replaced by
the smaller Sr atoms, which leads to a larger deformation of the surrounding
lattice and hence to a larger modulation amplitude. The more homogeneous the
filling of these channels with one atomic type (Ba) the lower the modulation
amplitude. Our results also show that the structure can be described with a
two-dimensional incommensurate harmonic modulation. No second order modulation
has been observed, both by single crystal diffraction measurements and q-scans.
The positional modulation of the Nb atoms is much smaller than that of the
oxygen atoms, such that the modulation can be seen as a rotational modulation
of almost rigid NbO6-octahedra.


title: Sum-frequency generation of 589 nm light with near-unit efficiency

abstract:
  We report on a laser source at 589 nm based on sum-frequency generation of
two infrared laser at 1064 nm and 1319 nm. Output power as high as 800 mW are
achieved starting from 370 mW at 1319 nm and 770 mW at 1064 nm, corresponding
to converting roughly 90% of the 1319 nm photons entering the cavity. The power
and frequency stability of this source are ideally suited for cooling and
trapping of sodium atoms.


title:
Hirota-Kimura Type Discretization of the Classical Nonholonomic Suslov
  Problem

abstract:
  We constructed Hirota-Kimura type discretization of the classical
nonholonomic Suslov problem of motion of rigid body fixed at a point. We found
a first integral proving integrability. Also, we have shown that discrete
trajectories asymptotically tend to a line of discrete analogies of so-called
steady-state rotations. The last property completely corresponds to well-known
property of the continuous Suslov case. The explicite formulae for solutions
are given. In n-dimensional case we give discrete equations.


title:
Local cohomology: Associated primes, artinianness and asymptotic
  behaviour

abstract:
  Let $R$ be a noetherian ring, $\fa$ an ideal of $R$, $M$ an $R$--module and
$n$ a non-negative integer.
  In this paper we first will study the finiteness properties of the kernel and
the cokernel of the natural map $f:\Ext^n_{R}(R/\fa,M)\lo
\Hom_{R}(R/\fa,\lc^{n}_{\fa}(M))$. Then we will get some corollaries about the
associated primes and artinianness of local cohomology modules. Finally we will
study the asymptotic behaviour of the kernel and the cokernel of this natural
map in the graded case.


title: Neutron photocrystallography: simulation and experiment

abstract:
  The investigation of light-induced structural changes by diffractive methods
has improved much in the last two decades. We present here the case of neutron
photocrystallography for which we have built a special experimental setup at
the single crystal neutron diffractometer TriCS at the Swiss Spallation Neutron
Source SINQ. We illustrate the progress of the method on the example of the
structural determination of photoinduced nitrosyl linkage-isomers in
Na2[Fe(CN)5NO] 2H2O. The in-situ determination of the population of the
light-induced linkage isomers by optical transmission measurements enhances the
reliability of such structural investigations considerably. Additionally we
present a new simulation tool within the program package JANA2006 which allows
to plan a photocrystallographic experiment thoroughly since the required
q-range, the minimally needed population of the photoinduced species, as well
as the necessary counting statistics for a successful single crystal
diffraction experiment can be evaluated in advance.


title:
The s-wave charmed baryon resonances from a coupled-channel approach
  with heavy quark symmetry

abstract:
  We study charmed baryon resonances which are generated dynamically within a
unitary meson-baryon coupled channel model that treats the heavy pseudoscalar
and vector mesons on equal footing as required by heavy-quark symmetry. It is
an extension of recent SU(4) models with t-channel vector meson exchanges to a
SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in
how the strong breaking of the flavor symmetry is implemented. Some of our
dynamically generated states can be readily assigned to recently observed
baryon resonances, while others do not have a straightforward identification
and require the compilation of more data as well as an extension of the model
to d-wave meson-baryon interactions and p-wave coupling in the neglected s- and
u-channel diagrams. Of several novelties, we find that the Lambda_c(2595),
which emerged as a ND quasi-bound state within the SU(4) approaches, becomes
predominantly a ND* quasi-bound state in the present SU(8) scheme.


title: First time-series optical photometry from Antarctica

abstract:
  Beating the Earth's day-night cycle is mandatory for long and continuous
time-series photometry and had been achieved with either large ground-based
networks of observatories at different geographic longitudes or when conducted
from space. A third possibility is offered by a polar location with
astronomically-qualified site characteristics. Aims. In this paper, we present
the first scientific stellar time-series optical photometry from Dome C in
Antarctica and analyze approximately 13,000 CCD frames taken in July 2007. We
conclude that high-precision CCD photometry with exceptional time coverage and
cadence can be obtained at Dome C in Antarctica and be successfully used for
time-series astrophysics.


title: On the Riesz and Baez-Duarte criteria for the Riemann Hypothesis

abstract:
  We investigate the relation between the Riesz and the B{\'a}ez-Duarte
criterion for the Riemann Hypothesis. In particular we present the relation
between the function $R(x)$ appearing in the Riesz criterion and the sequence
$c_k$ appearing in the B{\'a}ez-Duarte formulation. It is shown that $R(x)$ can
be expressed by $c_k$, and, vice versa, the sequence $c_k$ can be obtained from
the values of $R(x)$ at integer arguments. Also, we give some relations
involving $c_k$ and $R(x)$, and value of the alternating sum of $c_k$.


title: DescribeX: A Framework for Exploring and Querying XML Web Collections

abstract:
  This thesis introduces DescribeX, a powerful framework that is capable of
describing arbitrarily complex XML summaries of web collections, providing
support for more efficient evaluation of XPath workloads. DescribeX permits the
declarative description of document structure using all axes and language
constructs in XPath, and generalizes many of the XML indexing and summarization
approaches in the literature. DescribeX supports the construction of
heterogeneous summaries where different document elements sharing a common
structure can be declaratively defined and refined by means of path regular
expressions on axes, or axis path regular expression (AxPREs). DescribeX can
significantly help in the understanding of both the structure of complex,
heterogeneous XML collections and the behaviour of XPath queries evaluated on
them.
  Experimental results demonstrate the scalability of DescribeX summary
refinements and stabilizations (the key enablers for tailoring summaries) with
multi-gigabyte web collections. A comparative study suggests that using a
DescribeX summary created from a given workload can produce query evaluation
times orders of magnitude better than using existing summaries. DescribeX's
light-weight approach of combining summaries with a file-at-a-time XPath
processor can be a very competitive alternative, in terms of performance, to
conventional fully-fledged XML query engines that provide DB-like functionality
such as security, transaction processing, and native storage.


title: Towards an understanding of heavy baryon spectroscopy

abstract:
  The recent observation at CDF and D0 of $\Sigma_b$, $\Sigma^*_b$ and $\Xi_b$
baryons opens the door to the advent of new states in the bottom baryon sector.
The states measured provide sufficient constraints to fix the parameters of
phenomenological models. One may therefore consistently predict the full bottom
baryon spectra. For this purpose we have solved exactly the three-quark problem
by means of the Faddeev method in momentum space. We consider our guidance may
help experimentalists in the search for new bottom baryons and their findings
will help in constraining further the phenomenological models. We identify
particular states whose masses may allow to discriminate between the dynamics
for the light-quark pairs predicted by different phenomenological models.
Within the same framework we also present results for charmed, doubly charmed,
and doubly bottom baryons. Our results provide a restricted possible assignment
of quantum numbers to recently reported charmed baryon states. Some of them are
perfectly described by $D-$wave excitations with $J^P=5/2^+$, as the $\Lambda_c
(2880)$, $\Xi_c(3055)$, and $\Xi_c(3123)$.


title:
Electroplating of conformal electrodes for vacuum nanogap tunnel
  junction

abstract:
  In this study, we electroplate Cu electrode on Si substrate to realize a
large-area vacuum nanogap for electron tunneling. We used cathode coating,
cathode rotation, asymmetric current regime, and electrolyte temperature
stabilization to obtain the regular geometry of the Cu electrode and reduce its
internal tension. Subsequently, internal tension was altered to achieve the
predefined surface curvature (concave or convex). For 12-mm diameter Ag/Cu
electrode, we achieve the curvature of 40 nm/mm from the Ag side. Reduction of
the electrode diameter to 3 mm allowed curvature as low as of 2.5 nm/mm. It
also allowed fabrication of two conformal electrodes having a nanogap of less
than 5 nm wide, over the area of 7 mm2. Such electrodes can be used for
efficient energy conversion and cooling in the mixed thermionic and
thermotunneling regime.


title: Signatures of reionization on Lyman alpha emitters

abstract:
  We use a semi-analytic model of Lyman alpha emitters (LAEs) to constrain the
reionization history. By considering two physically motivated scenarios in
which reionization ends either early (ERM, z_i ~ 7) or late (LRM, z_i ~ 6), we
fix the global value of the IGM neutral fraction (e.g. chi_{HI}=3 times
10^{-4}, 0.15 at z=6.56 for the ERM and LRM, respectively) leaving only the
star formation efficiency and the effective escape fraction of Lya photons as
free parameters. The ERM fits the observed LAE luminosity function (LF) at
z=5.7 and 6.56 requiring no redshift evolution or mass dependence of the star
formation efficiency, and LAE star formation rates (SFR) of 3-103 solar
masses/year, contributing approximately 8% of the cosmic SFR density at z=5.7.
The LRM requires a physically uncomfortable drop of approximately 4.5 times in
the SFR of the emitters from z=6.5 to 5.7. Thus, the data seem to imply that
the Universe was already highly ionized at z=6.56. The mass-dependent Lya
transmissivity is between 0.36-0.51 (ERM) and less than 0.26 (LRM) at z=6.56.
The LF data at z=4.5 imply an extra Lya line damping factor of approximately
0.25 possibly due to dust; the presence of a (clumpy) dust component with
E(B-V) ~ 0.28 is also required to reproduce the observed large Lya equivalent
widths at the same redshift. Additional useful information can be extracted
from the line profile (weighted) skewness, found to be S_W=10-17 Angstrom for
the two reionization models, which shows an interesting L_alpha-chi_{HI}
anti-correlation, holding under the model assumptions. The shortcomings of the
model and strategies to overcome them are discussed.


title:
Solutions by radicals at singular values k_N from new class invariants
  for N \equiv 3 mod 8

abstract:
  For square-free $N\equiv3$ mod 8 and $N$ coprime to 3, I show how to reduce
the singular value $k_N$ to radicals, using a novel pair $[f,g]$ of real
numbers that are algebraic integers of the Hilbert class field of
$Q(\sqrt{-N})$. One is a class invariant of modular level 48, with a growth
$g=\alpha(N)\exp(\pi\sqrt{N}/48)+o(1)$, where $\alpha(N)\in[-\sqrt2,\sqrt2]$ is
uniquely determined by the residue of $N$ modulo 64. Hence $g$ is a very
economical generator of the class field. For prime $N\equiv3$ mod 4, I
conjecture that the Chowla--Selberg formula provides an algebraic {\em unit} of
the class field and determine its minimal polynomial for the 155 cases with
$N<2000$. For N=2317723, with class number $h(-N)=105$, I compute the minimal
polynomial of $g$ in 90 milliseconds. Its height is smaller than the {\em cube}
root of the height of the generating polynomial found by the double
eta-quotient method of {\em Pari-GP}. I reduce the complete elliptic integral
$K_{2317723}$ to radicals and values of the $\Gamma$ function, by determining
the Chowla--Selberg unit and solving the septic, quintic and cubic equations
that generate sub-fields of the class field. I conclude that the residue 3
modulo 8, initially discarded in elliptic curve primality proving, outperforms
the residue 7.


title: Loop-Cluster Simulation of the $t$-$J$ Model on the Honeycomb Lattice

abstract:
  Inspired by the lattice structure of the unhydrated variant of the
superconducting material Na$_x$CoO$_2 \cdot$yH$_2$O at $ x = {1/3}$, we study
the $t$-$J$ model on a honeycomb lattice by using an efficient loop-cluster
algorithm. The low-energy physics of the undoped system and of the single hole
sector is described by a systematic low-energy effective field theory. The
staggered magnetization per spin $\widetilde{{\cal M}}_s = 0.2688(3)$, the spin
stiffness $\rho_s = 0.102(2) J$, the spin wave velocity $c= 1.297(16) J a$, and
the kinetic mass $M'$ of a hole are obtained by fitting the numerical Monte
Carlo data to the effective theory predictions.


title: Switching Current Measurements in Josephson Rings

abstract:
  We present switching current measurements in niobium-aluminum oxide-niobium
underdamped Josephson rings. Underdamped Josephson rings display hysteretic
current-voltage curves which can be characterized by their switching current,
the value of applied current at which the junctions switch to the energy-gap
voltage. The value of the switching current is strongly affected by temperature
and by the presence of fluxons in the system. We observe a very small voltage
(0.2 nV) across the ring prior to switching, indicating a low-velocity fluxon
diffusion state before the jump to a full running state. In analogy with
previous work on single junctions, we analyze the switching current data with
the process of thermal activation over a dissipation barrier, where the system
switches from a low velocity state to a high velocity state. We find that our
data agrees qualitatively with this description, further supporting the
observation of fluxon diffusion.


title: The two-body problem of ultra-cold atoms in a harmonic trap

abstract:
  We consider two bosonic atoms interacting with a short-range potential and
trapped in a spherically symmetric harmonic oscillator. The problem is exactly
solvable and is relevant for the study of ultra-cold atoms. We show that the
energy spectrum is universal, irrespective of the shape of the interaction
potential, provided its range is much smaller than the oscillator length.


title: On the finiteness theorem for rational maps on a variety of general type

abstract:
  The dominant rational maps of finite degree from a fixed variety to varieties
of general type, up to birational isomorphisms, form a finite set. This has
been known as the Iitaka-Severi conjecture, and is nowdays an established
result, in virtue of some recent advances in the theory of pluricanonical maps.
We study the question of finding some effective estimate for the finite number
of maps, and to this aim we provide some update and refinement of the classical
treatment of the subject.


title:
The Littlewood--Paley--Rubio de Francia property of a Banach space for
  the case of equal intervals

abstract:
  Let $X$ be a Banach space. It is proved that an analogue of the Rubio de
Francia square function estimate for partial sums of the Fourier series of
$X$-valued functions holds true for all disjoint collections of subintervals of
the set of integers of equal length and for all exponents $p$ greater or equal
than 2 if and only if the space $X$ is a UMD space of type 2. The same
criterion is obtained for the case of subintervals of the real line and Fourier
integrals instead of Fourier series.


title: Weak Expectations and the Injective Envelope

abstract:
  Given a unital C*-subalgebra of B(H), we study the set of all possible images
of its injective envelope that are contained in B(H) and their position
relative to the double commutant of the algebra in order to obtain more
information about the existence or non-existence of weak expectations. We study
the subset of B(H) that is the intersection of all possible images of the
injective envelope and show that it is simultaneously a reflexive cover and a
new type of order completion of the algebra.


title:
On Probability Distributions for Trees: Representations, Inference and
  Learning

abstract:
  We study probability distributions over free algebras of trees. Probability
distributions can be seen as particular (formal power) tree series [Berstel et
al 82, Esik et al 03], i.e. mappings from trees to a semiring K . A widely
studied class of tree series is the class of rational (or recognizable) tree
series which can be defined either in an algebraic way or by means of
multiplicity tree automata. We argue that the algebraic representation is very
convenient to model probability distributions over a free algebra of trees.
First, as in the string case, the algebraic representation allows to design
learning algorithms for the whole class of probability distributions defined by
rational tree series. Note that learning algorithms for rational tree series
correspond to learning algorithms for weighted tree automata where both the
structure and the weights are learned. Second, the algebraic representation can
be easily extended to deal with unranked trees (like XML trees where a symbol
may have an unbounded number of children). Both properties are particularly
relevant for applications: nondeterministic automata are required for the
inference problem to be relevant (recall that Hidden Markov Models are
equivalent to nondeterministic string automata); nowadays applications for Web
Information Extraction, Web Services and document processing consider unranked
trees.


title: On the tensor reduction of one-loop pentagons and hexagons

abstract:
  We perform analytical reductions of one-loop tensor integrals with 5 and 6
legs to scalar master integrals. They are based on the use of recurrence
relations connecting integrals in different space-time dimensions. The
reductions are expressed in a compact form in terms of signed minors, and have
been implemented in a mathematica package called hexagon.m. We present several
numerical examples.


title: The final mass and spin of black hole mergers

abstract:
  We consider black holes resulting from binary black hole mergers. By fitting
to numerical results we construct analytic formulas that predict the mass and
spin of the final black hole. Our formulas are valid for arbitrary initial
spins and mass ratios and agree well with available numerical simulations. We
use our spin formula in the context of two common merger scenarios for
supermassive galactic black holes. We consider the case of isotropically
distributed initial spin orientations (when no surrounding matter is present)
and also the case when matter closely aligns the spins with the orbital angular
momentum. The spin magnitude of black holes resulting from successive
generations of mergers (with symmetric mass ratio $\eta$) has a mean of
$1.73\eta + 0.28$ in the isotropic case and 0.94 for the closely aligned case.


title:
QCD plasma thermalization, collective flow and extraction of shear
  viscosity

abstract:
  Fast thermalization and elliptic flow of QCD matter found at the Relativistic
Heavy Ion Collider (RHIC) are understood as the consequence of perturbative QCD
(pQCD) interactions within a (3+1) dimensional parton cascade. The main
contributions stem from pQCD-inspired bremsstrahlung. We extract the shear
viscosity to entropy ratio, which is between 0.08 and 0.15.


title: Stochastic domination for the last passage percolation model

abstract:
  A competition model on $\mathbb{Z}_+^{2}$ governed by directed last passage
percolation is considered. A stochastic domination argument between subtrees of
the last passage percolation is put forward.


title: Negro and Danube are mirror rivers

abstract:
  We study the European river Danube and the South American river Negro daily
water levels. We present a fit for the Negro daily water level period and
standard deviation. Unexpectedly, we discover that the river Negro and Danube
are mirror rivers in the sense that the daily water levels fluctuations
histograms are close to the BHP and reversed BHP, respectively.


title: Premetric electrodynamics

abstract:
  Classical electrodynamics can be divided into two parts. In the first one,
with the use of a plenty of directed quantities, namely multivectors and
differential forms, no scalar product is necessary. It is called premetric
electrodynamics. In this part, principal laws of the theory can be tackled,
among them the two observer-independent Maxwell's equations. The second part
concerns specific media and requires establishing of a scalar product and,
consequently a metric. We present an axiomatic approach to electrodynamics in
which the metric enters as late as possible. Also a line of research is
mentioned in which the notion of non-inertial observer is studied and its
influence on observer- dependent Maxwell equations.


title: Excited states of a string in a time dependent orbifold

abstract:
  We present analytical results on the propagation of a classical string in
non-zero modes through the singularity of the compactified Milne space. We
restrict our analysis to a string winding around the compact dimension of
spacetime. The compact dimension undergoes contraction to a point followed by
re-expansion. We demonstrate that the classical dynamics of the string in
excited states is non-singular in the entire spacetime.


title:
Exact low-temperature properties of a class of highly frustrated Hubbard
  models

abstract:
  We study the repulsive Hubbard model both analytically and numerically on a
family of highly frustrated lattices which have one-electron states localized
on isolated trapping cells. We construct and count exact many-electron ground
states for a wide range of electron densities and obtain closed-form
expressions for the low-temperature thermodynamic quantities. Furthermore, we
find that saturated ferromagnetism is obtained only for sufficiently high
electron densities and large Hubbard repulsion $U$ while there is no finite
average moment in the ground states at lower densities.


title:
Structure constants of $su(2S+1)$ algebra and the decomplexification of
  the Liouville-von Neumann equation

abstract:
  he analytic formulas for structure constants of $su(2S+1)$ algebra in terms
of $3jm$ and $6j$ symbols of $su(2)$ have been derived for the
decomplexification of the Liouville-von Neumann equation.


title: Establishing and Measuring Standard Spreadsheet Practices for End-Users

abstract:
  This paper offers a brief review of cognitive verbs typically used in the
literature to describe standard spreadsheet practices. The verbs identified are
then categorised in terms of Bloom's Taxonomy of Hierarchical Levels, and then
rated and arranged to distinguish some of their qualities and characteristics.
Some measurement items are then evaluated to see how well computerised test
question items validate or reinforce training or certification. The paper
considers how establishing standard practices in spreadsheet training and
certification can help reduce some of the risks associated with spreadsheets,
and help promote productivity.


title: Classification of 64-element finite semifields

abstract:
  A finite semifield $D$ is a finite nonassociative ring with identity such
that the set $D^*=D\setminus\{0\}$ is closed under the product. In this paper
we obtain a computer-assisted description of all 64-element finite semifields,
which completes the classification of finite semifields of order 125 or less.


title: Mean surface shape of a human placenta

abstract:
  The chorionic plate (or "fetal surface") of the human placenta is drawn as
round, with the umbilical cord inserted roughly at the center, but variability
of this shape is common. The average shape of the chorionic plate has never
been established. The goal of this work is to measure the average shape in a
birth cohort.


title:
Mach cones in the quark-gluon plasma: Viscosity, speed of sound, and
  effects of finite source structure

abstract:
  I use the space-time distribution of energy and momentum deposited by a fast
parton traversing a perturbative quark-gluon plasma as a source term for the
linearized hydrodynamical equations of the medium. A method of solution for the
medium response is presented in detail. Numerical results are given for
different values of the shear viscosity to entropy density ratio, $\eta/s$, and
speed of sound, $c_s$. Furthermore, I investigate the relevance of finite
source structure by expanding the source term up to first order in gradients of
a $\delta$ function centered at the fast parton and comparing the resulting
dynamics to that obtained with the full source. It is found that, for the
source term used here, the medium response is sensitive to the finite source
structure up to distances of several fm from the source parton.


title: Reducing Spreadsheet Risk with FormulaDataSleuth

abstract:
  A new MS Excel application has been developed which seeks to reduce the risks
associated with the development, operation and auditing of Excel spreadsheets.
FormulaDataSleuth provides a means of checking spreadsheet formulas and data as
they are developed or used, enabling the users to identify actual or potential
errors quickly and thereby halt their propagation. In this paper, we will
describe, with examples, how the application works and how it can be applied to
reduce the risks associated with Excel spreadsheets.


title:
The Magellanic zoo: Mid-infrared Spitzer spectroscopy of evolved stars
  and circumstellar dust in the Magellanic Clouds

abstract:
  We observed a sample of evolved stars in the Large and Small Magellanic
Clouds (LMC and SMC) with the Infrared Spectrograph on the Spitzer Space
Telescope. Comparing samples from the SMC, LMC, and the Galaxy reveals that the
dust-production rate depends on metallicity for oxygen-rich stars, but carbon
stars with similar pulsation properties produce similar quantities of dust,
regardless of their initial metallicity. Other properties of the oxygen-rich
stars also depend on metallicity. As the metallicity decreases, the fraction of
naked (i.e. dust-free) stars increases, and among the naked stars, the strength
of the 8 um absorption band from SiO decreases. Our sample includes several
massive stars in the LMC with long pulsation periods which produce significant
amounts of dust, probably because they are young and relatively metal rich.
Little alumina dust is seen in circumstellar shells in the SMC and LMC, unlike
in Galactic samples. Three oxygen-rich sources also show emission from
magnesium-rich crystalline silicates. Many also show an emission feature at 14
um. The one S star in our sample shows a newly detected emission feature
centered at 13.5 um. At lower metallicity, carbon stars with similar amounts of
amorphous carbon in their shells have stronger absorption from molecular
acetylene (C_2H_2) and weaker emission from SiC and MgS dust, as discovered in
previous studies.


title:
Matching gluon scattering amplitudes and Wilson loops in off-shell
  regularization

abstract:
  We construct a regularization for light-like polygonal Wilson loops in ${\cal
N}=4$ SYM, which matches them to the off-shell MHV gluon scattering amplitudes.
Explicit calculations are performed for the 1-loop four gluon case. The off
light cone extrapolation has to be based on the local supersymmetric Wilson
loop. The observed matching concerns Feynman gauge. Furthermore, the leading
infrared divergent term is shown to be gauge parameter independent on 1-loop
level.


title: Time-Distance analysis of the Emerging Active Region NOAA 10790

abstract:
  We investigate the emergence of Active Region NOAA 10790 by means of
time--distance helioseismology. Shallow regions of increased sound speed at the
location of increased magnetic activity are observed, with regions becoming
deeper at the locations of sunspot pores. We also see a long-lasting region of
decreased sound speed located underneath the region of the flux emergence,
possibly relating to a temperature perturbation due to magnetic quenching of
eddy diffusivity, or to a dense flux tube. We detect and track an object in the
subsurface layers of the Sun characterised by increased sound speed which could
be related to emerging magnetic flux and thus obtain a provisional estimate of
the speed of emergence of around $1 {\rm km s^{-1}}$.


title:
Oxygen-related traps in pentacene thin films: Energetic position and
  implications for transistor performance

abstract:
  We studied the influence of oxygen on the electronic trap states in a
pentacene thin film. This was done by carrying out gated four-terminal
measurements on thin-film transistors as a function of temperature and without
ever exposing the samples to ambient air. Photooxidation of pentacene is shown
to lead to a peak of trap states centered at 0.28 eV from the mobility edge,
with trap densities of the order of 10(18) cm(-3). These trap states need to be
occupied at first and cause a reduction in the number of free carriers, i.e. a
consistent shift of the density of free holes as a function of gate voltage.
Moreover, the exposure to oxygen reduces the mobility of the charge carriers
above the mobility edge. We correlate the change of these transport parameters
with the change of the essential device parameters, i.e. subthreshold
performance and effective field-effect mobility. This study supports the
assumption of a mobility edge for charge transport, and contributes to a
detailed understanding of an important degradation mechanism of organic
field-effect transistors. Deep traps in an organic field-effect transistor
reduce the effective field-effect mobility by reducing the number of free
carriers and their mobility above the mobility edge.


title: Exploring the effect of sex on an empirical fitness landscape

abstract:
  The nature of epistasis has important consequences for the evolutionary
significance of sex and recombination. Recent efforts to find negative
epistasis as source of negative linkage disequilibrium and associated long-term
sex advantage have yielded little support. Sign epistasis, where the sign of
the fitness effects of alleles varies across genetic backgrounds, is
responsible for ruggedness of the fitness landscape with implications for the
evolution of sex that have been largely unexplored. Here, we describe fitness
landscapes for two sets of strains of the asexual fungus \emph{Aspergillus
niger} involving all combinations of five mutations. We find that $\sim 30$% of
the single-mutation fitness effects are positive despite their negative effect
in the wild-type strain, and that several local fitness maxima and minima are
present. We then compare adaptation of sexual and asexual populations on these
empirical fitness landscapes using simulations. The results show a general
disadvantage of sex on these rugged landscapes, caused by the break down by
recombination of genotypes escaping from local peaks. Sex facilitates escape
from a local peak only for some parameter values on one landscape, indicating
its dependence on the landscape's topography. We discuss possible reasons for
the discrepancy between our results and the reports of faster adaptation of
sexual populations.


title: On the notion of gauge symmetries of generic Lagrangian field theory

abstract:
  General Lagrangian theory of even and odd fields on an arbitrary smooth
manifold is considered. Its non-trivial reducible gauge symmetries and their
algebra are defined in this very general setting by means of the inverse second
Noether theorem. In contrast with gauge symmetries, non-trivial Noether and
higher-stage Noether identities of Lagrangian theory can be intrinsically
defined by constructing the exact Koszul-Tate complex. The inverse second
Noether theorem that we prove associates to this complex the cochain sequence
with the ascent operator whose components define non-trivial gauge and
higher-stage gauge symmetries. These gauge symmetries are said to be
algebraically closed if the ascent operator can be extended to a nilpotent
operator. The necessary conditions for this extension are stated. The
characteristic examples of Yang-Mills supergauge theory, topological
Chern-Simons theory, gauge gravitation theory and topological BF theory are
presented.


title: Neutrinos and BBN (and the CMB)

abstract:
  During Big Bang Nucleosynthesis (BBN), in the first 20 minutes of the
evolution of the Universe, the light nuclides, D, 3He, 4He, and 7Li were
synthesized in astrophysically interesting abundances. The Cosmic Microwave
Background Radiation (CMB) observed at present was last scattered some 400
thousand years later. BBN and the CMB (supplemented by more recent Large Scale
Structure data), provide complementary probes of the early evolution of the
Universe and enable constraints on the high temperature/energy physical
processes in it. In this overview the predictions and observations of two
physical quantities, the baryon density parameter and the expansion rate
parameter, are compared to see if there is agreement between theory and
observation at these two widely separated epochs. After answering this question
in the affirmative, the consequences of this concordance for physics beyond the
standard models of particle physics and cosmology is discussed.


title: X-ray flares in Orion young stars. I. Flare characteristics

abstract:
  Pre-main sequence (PMS) stars are known to produce powerful X-ray flares
which resemble magnetic reconnection solar flares scaled by factors up to 10^4.
However, numerous puzzles are present including the structure of X-ray emitting
coronae and magnetospheres, effects of protoplanetary disks, and effects of
stellar rotation. To investigate these issues in detail, we examine 216 of the
brightest flares from 161 PMS stars observed in the Chandra Orion Ultradeep
Project (COUP). These constitute the largest homogeneous dataset of PMS, or
indeed stellar flares at any stellar age, ever acquired. Our effort is based on
a new flare spectral analysis technique that avoids nonlinear parametric
modeling. It can be applied to much weaker flares and is more sensitive than
standard methods. We provide a catalog with >30 derived flare properties and an
electronic atlas for this unique collection of stellar X-ray flares. The
current study (Paper I) examines the flare morphologies, and provides general
comparison of COUP flare characteristics with those of other active X-ray stars
and the Sun. Paper II will concentrate on relationships between flare behavior,
protoplanetary disks, and other stellar properties. Several results are
obtained. First, the COUP flares studied here are among the most powerful,
longest, and hottest stellar X-ray flares ever studied. Second, no significant
statistical differences in peak flare luminosity or temperature distributions
are found among different morphological flare classes, suggesting a common
underlying mechanism for all flares. Third, comparison with the general
solar-scaling laws indicates that COUP flares may not fit adequately proposed
power-temperature and duration-temperature solar-stellar fits. Fourth, COUP
super-hot flares are found to be brighter but shorter than ... ABRIDGED


title: The rank convergence of HITS can be slow

abstract:
  We prove that HITS, to "get right" h of the top k ranked nodes of an N>=2k
node graph, can require h^(Omega(N h/k)) iterations (i.e. a substantial Omega(N
h log(h)/k) matrix multiplications even with a "squaring trick"). Our proof
requires no algebraic tools and is entirely self-contained.


title:
X-Ray flares in Orion Young Stars. II. Flares, Magnetospheres, and
  Protoplanetary Disks

abstract:
  We study the properties of powerful X-ray flares from 161 pre-main sequence
(PMS) stars observed with the Chandra X-ray Observatory in the Orion Nebula
region. Relationships between flare properties, protoplanetary disks and
accretion are examined in detail to test models of star-disk interactions at
the inner edge of the accretion disks. Previous studies had found no
differences in flaring between diskfree and accreting systems other than a
small overall diminution of X-ray luminosity in accreting systems. The most
important finding is that X-ray coronal extents in fast-rotating diskfree stars
can significantly exceed the Keplerian corotation radius, whereas X-ray loop
sizes in disky and accreting systems do not exceed the corotation radius. This
is consistent with models of star-disk magnetic interaction where the inner
disk truncates and confines the PMS stellar magnetosphere. We also find two
differences between flares in accreting and diskfree PMS stars. First, a
subclass of super-hot flares with peak plasma temperatures exceeding 100 MK are
preferentially present in accreting systems. Second, we tentatively find that
accreting stars produce flares with shorter durations. Both results may be
consequences of the distortion and destabilization of the stellar magnetosphere
by the interacting disk. Finally, we find no evidence that any flare types,
even slow-rise flat-top flares are produced in star-disk magnetic loops. All
are consistent with enhanced solar long-duration events with both footprints
anchored in the stellar surface.


title: Inference from Matrix Products: A Heuristic Spin Glass Algorithm

abstract:
  We present an algorithm for finding ground states of two dimensional spin
glass systems based on ideas from matrix product states in quantum information
theory. The algorithm works directly at zero temperature and defines an
approximate "boundary Hamiltonian" whose accuracy depends on a parameter $k$.
We test the algorithm against exact methods on random field and random bond
Ising models, and we find that accurate results require a $k$ which scales
roughly polynomially with the system size. The algorithm also performs well
when tested on small systems with arbitrary interactions, where no fast, exact
algorithms exist. The time required is significantly less than Monte Carlo
schemes.


title: Special Relativity in the 21$^{\rm st}$ century

abstract:
  This paper, which is meant to be a tribute to Minkowski's geometrical
insight, rests on the idea that the basic observed symmetries of spacetime
homogeneity and of isotropy of space, which are displayed by the spacetime
manifold in the limiting situation in which the effects of gravity can be
neglected, leads to a formulation of special relativity based on the appearance
of two universal constants: a limiting speed $c$ and a cosmological constant
$\Lambda$ which measures a residual curvature of the universe, which is not
ascribable to the distribution of matter-energy. That these constants should
exist is an outcome of the underlying symmetries and is confirmed by
experiments and observations, which furnish their actual values. Specifically,
it turns out on these foundations that the kinematical group of special
relativity is the de Sitter group $dS(c,\Lambda)=SO(1,4)$. On this basis, we
develop at an elementary classical and, hopefully, sufficiently didactical
level the main aspects of the theory of special relativity based on SO(1,4) (de
Sitter relativity). As an application, we apply the formalism to an intrinsic
formulation of point particle kinematics describing both inertial motion and
particle collisions and decays.


title:
Some conjectures on addition and multiplication of complex (real)
  numbers

abstract:
  We discuss conjectures related to the following two conjectures:
  (1) for each complex numbers x_1,...,x_n there exist rationals y_1,...,y_n
\in [-2^{n-1},2^{n-1}] such that
  \forall i \in {1,...,n} (x_i=1 \Rightarrow y_i=1)
  \forall i,j,k \in {1,...,n} (x_i+x_j=x_k \Rightarrow y_i+y_j=y_k)
  (2) for each complex (real) numbers x_1,...,x_n there exist complex (real)
numbers y_1,...,y_n such that
  \forall i \in {1,...,n} |y_i| \leq 2^{2^{n-2}}
  \forall i \in {1,...,n} (x_i=1 \Rightarrow y_i=1)
  \forall i,j,k \in {1,...,n} (x_i+x_j=x_k \Rightarrow y_i+y_j=y_k)
  \forall i,j,k \in {1,...,n} (x_i \cdot x_j=x_k \Rightarrow y_i \cdot y_j=y_k)


title:
Driving-induced crossover: from classical criticality to self-organized
  criticality

abstract:
  We propose a spin model with quenched disorder which exhibits in slow driving
two drastically different types of critical nonequilibrium steady states. One
of them corresponds to classical criticality requiring fine-tuning of the
disorder. The other is a self-organized criticality which is insensitive to
disorder. The crossover between the two types of criticality is determined by
the mode of driving. As one moves from "soft" to "hard" driving the
universality class of the critical point changes from a classical
order-disorder to a quenched Edwards-Wilkinson universality class. The model is
viewed as prototypical for a broad class of physical phenomena ranging from
magnetism to earthquakes.


title: Properly ordered dimers, $R$-charges, and an efficient inverse algorithm

abstract:
  The $\mathcal{N}=1$ superconformal field theories that arise in AdS-CFT from
placing a stack of D3-branes at the singularity of a toric Calabi-Yau threefold
can be described succinctly by dimer models. We present an efficient algorithm
for constructing a dimer model from the geometry of the Calabi-Yau. Since not
all dimers produce consistent field theories, we perform several consistency
checks on the field theories produced by our algorithm: they have the correct
number of gauge groups, their cubic anomalies agree with the Chern-Simons
coefficients in the AdS dual, and all gauge invariant chiral operators satisfy
the unitarity bound. We also give bounds on the ratio of the central charge of
the theory to the area of the toric diagram. To prove these results, we
introduce the concept of a properly ordered dimer.


title: Super Linear Algebra

abstract:
  In this book, the authors introduce the notion of Super linear algebra and
super vector spaces using the definition of super matrices defined by Horst
(1963). This book expects the readers to be well-versed in linear algebra. Many
theorems on super linear algebra and its properties are proved. Some theorems
are left as exercises for the reader. These new class of super linear algebras
which can be thought of as a set of linear algebras, following a stipulated
condition, will find applications in several fields using computers. The
authors feel that such a paradigm shift is essential in this computerized
world. Some other structures ought to replace linear algebras which are over a
century old. Super linear algebras that use super matrices can store data not
only in a block but in multiple blocks so it is certainly more powerful than
the usual matrices. This book has 3 chapters. Chapter one introduces the notion
of super vector spaces and enumerates a number of properties. Chapter two
defines the notion of super linear algebra, super inner product spaces and
super bilinear forms. Several interesting properties are derived. The main
application of these new structures in Markov chains and Leontief economic
models are also given in this chapter. The final chapter suggests 161 problems
mainly to make the reader understand this new concept and apply them.


title: Prospects for near-infrared characterisation of hot Jupiters with VSI

abstract:
  In this paper, we study the feasibility of obtaining near-infrared spectra of
bright extrasolar planets with the 2nd generation VLTI Spectro-Imager
instrument (VSI), which has the required angular resolution to resolve nearby
hot Extrasolar Giant Planets (EGPs) from their host stars. Taking into account
fundamental noises, we simulate closure phase measurements of several
extrasolar systems using four 8-m telescopes at the VLT and a low spectral
resolution (R = 100). Synthetic planetary spectra from T. Barman are used as an
input. Standard chi2-fitting methods are then used to reconstruct planetary
spectra from the simulated data. These simulations show that low-resolution
spectra in the H and K bands can be retrieved with a good fidelity for half a
dozen targets in a reasonable observing time (about 10 hours, spread over a few
nights). Such observations would strongly constrain the planetary temperature
and albedo, the energy redistribution mechanisms, as well as the chemical
composition of their atmospheres. Systematic errors, not included in our
simulations, could be a serious limitation to these performance estimations.
The use of integrated optics is however expected to provide the required
instrumental stability (around 10^-4 on the closure phase) to enable the first
thorough characterisation of extrasolar planetary emission spectra in the
near-infrared.


title: Quantum $RLC$ circuits: charge discreteness and resonance

abstract:
  In a recent article, we have advanced a semiclassical theory of quantum
circuits with discrete charge and electrical resistance. In this work, we
present a few elementary applications of this theory. For the zero resistance,
inductive circuit, we obtain the Stark ladder energies in yet another way; and
generalize earlier results by Chandia et. al, for the circuit driven by a
combination d.c. plus a.c. electromotive force (emf). As a second application,
we investigate the effect of electrical resistance, together with charge
discreteness, in the current amplitude, and resonance conditions of a general
$RLC$ quantum circuit, including nonlinear effects up to third order on the
external sinusoidal emf.


title: Simple Front End Electronics for Multigap Resistive Plate Chambers

abstract:
  A simple circuit for the presentation of the signals from Multi-gap Resistive
Plate Chambers (MRPCs) to standard existing digitization electronics is
described. The circuit is based on "off-the-shelf" discrete components. An
optimization of the values of specific components is required to match the
aspects of the MRPCs for the given application. This simple circuit is an
attractive option for the initial signal processing for MRPC prototyping and
bench- or beam-testing efforts, as well as for final implementations of
small-area Time-of-Flight systems with existing data acquisition systems.


title: Stellar Evolution and Variability in the Pre-ZAHB Phase

abstract:
  One of the most dramatic events in the life of a low-mass star is the He
flash, which takes place at the tip of the RGB and is followed by a series of
secondary flashes before the star settles on the zero-age HB (ZAHB). Yet, no
stars have ever been positively identified in this key phase in the life of a
low-mass star (hereafter the "pre-ZAHB" phase). We investigate the possibility
that some pre-ZAHB stars may cross the instability strip (IS), thus becoming
variable. In particular, it has been suggested that some RR Lyrae stars (RRL)
with high period change rates (P-dot) may in fact be pre-ZAHB stars. We present
the first theoretical effort devoted to interpreting some of the high-P-dot
stars as pre-ZAHB pulsators. We constructed a grid of evolutionary tracks using
the Garching Stellar Evolution Code for a chemical composition appropriate to
the case of the globular cluster M3, where a number of stars with high P-dot
values are found. We follow each star's pre-ZAHB evolution in detail, compute
periods and P-dot values for the stars lying inside the IS, and produce
pre-ZAHB Monte Carlo simulations for the case of M3. Our results indicate that
one should expect of order 1 pre-ZAHB star for every 60 or so bona-fide HB
stars in M3. Among the pre-ZAHB stars, ~22% are expected to fall within the IS
boundaries, presenting RRL-like pulsations. On average, the pre-ZAHB pulsators
are expected to have longer periods than the bona-fide HB pulsators, and 76% of
them are predicted to show negative P-dot values. The most likely P-dot value
for the pre-ZAHB variables is ~-0.3 d/Myr, but more extreme P-dot values are
also possible: 38% of the variables are predicted to have P-dot < -0.8 d/Myr.
It appears likely, therefore, that some RRL stars in M3 with high (absolute)
P-dot values are pre-ZAHB pulsators in disguise. (abridged)


title:
On the first Stiefel-Whitney class of moduli space for real rational
  stable curves in the projective space

abstract:
  Moduli space of genus zero stable maps to the projective three-space
naturally carries a real structure such that the fixed locus is a moduli space
for real rational spatial curves with real marked points. The latter is a
normal projective real variety. The singular locus being in codimension at
least two, a first Stiefel-Whitney class is well defined. In this paper, we
determine a representative for the first Stiefel-Whitney class of such real
space when the evaluation map is generically finite. This can be done by means
of Poincar\'e duals of boundary divisors.


title: Stable, metastable and unstable states in the mean-field RFIM at T=0

abstract:
  We compute the probability of finding metastable states at a given field in
the mean-field random field Ising model at T=0. Remarkably, this probability is
finite in the thermodynamic limit, even on the so-called ``unstable'' branch of
the magnetization curve. This implies that the branch is reachable when the
magnetization is controlled instead of the magnetic field, in contrast with the
situation in the pure system.


title:
Imaging reconstruction for infrared interferometry: first images of YSOs
  environment

abstract:
  The study of protoplanetary disks, where the planets are believed to form,
will certainly allow the formation of our Solar System to be understood. To
conduct observations of these objects at the milli-arcsecond scale, infrared
interferometry provides the right performances for T Tauri, FU Ori or Herbig
Ae/Be stars. However, the only information obtained so far are scarce
visibility measurements which are directly tested with models. With the outcome
of recent interferometers, one can foresee obtaining images reconstructed
independently of the models. In fact, several interferometers including IOTA
and AMBER on the VLTI already provide the possibility to recombine three
telescopes at once and thus to obtain the data necessary to reconstruct images.
In this paper, we describe the use of MIRA, an image reconstruction algorithm
developed for optical inter- ferometry data (squared visibilities and closure
phases) by E. Thiebaut. We foresee also to use the spectral information given
by AMBER data to constrain even better the reconstructed images. We describe
the use of MIRA to reconstruct images of young stellar objects out of actual
data, in particular the multiple system GW Orionis (IOTA, 2004), and discuss
the encountered difficulties.


title: Nonuniform states in noncentrosymmetric superconductors

abstract:
  In noncentrosymmetric crystals, nonuniform superconducting states are
possible even in the absence of any external magnetic field. The origin of
these states can be traced to the Lifshitz invariants in the free energy, which
are linear in spatial gradients. We show how various types of the Lifshitz
invariants in noncentrosymmetric superconductors can be derived from
microscopic theory.


title:
On the Global Attractor of Delay Differential Equations with Unimodal
  Feedback

abstract:
  We give bounds for the global attractor of the delay differential equation
$x'(t) =-\mu x(t)+f(x(t-\tau))$, where $f$ is unimodal and has negative
Schwarzian derivative. If $f$ and $\mu$ satisfy certain condition, then,
regardless of the delay, all solutions enter the domain where f is monotone
decreasing and the powerful results for delayed monotone feedback can be
applied to describe the asymptotic behaviour of solutions. In this situation we
determine the sharpest interval that contains the global attractor for any
delay. In the absence of that condition, improving earlier results, we show
that if the d5A5Aelay is sufficiently small, then all solution enter the domain
where $f'$ is negative. Our theorems then are illustrated by numerical examples
using Nicholson's blowflies equation and the Mackey-Glass equation.


title: Electroweak Physics

abstract:
  The results of high precision weak neutral current (WNC), Z-pole, and high
energy collider electroweak experiments have been the primary prediction and
test of electroweak unification. The electroweak program is briefly reviewed
from a historical perspective. The current status and the implications for the
standard model and beyond are discussed.


title:
The Spectrum and the Spectral Type of the Off-Diagonal Fibonacci
  Operator

abstract:
  We consider Jacobi matrices with zero diagonal and off-diagonals given by
elements of the hull of the Fibonacci sequence and show that the spectrum has
zero Lebesgue measure and all spectral measures are purely singular continuous.
In addition, if the two hopping parameters are distinct but sufficiently close
to each other, we show that the spectrum is a dynamically defined Cantor set,
which has a variety of consequences for its local and global fractal dimension.


title: A Quantum Imager for Intensity Correlated Photons

abstract:
  We report on a novel device capable of imaging second-order spatio-temporal
correlations g2(x,t) between photons. The imager is based on a monolithic array
of single-photon avalanche diodes (SPAD) implemented in CMOS technology and a
simple algorithm to treat multiphoton time-of-arrival distributions from
different SPAD pairs. It is capable of 80 ps temporal resolution with fluxes as
low as 10 photons/s at room temperature. An important application might be the
local imaging of g2 as a means of confirming the presence of true Bose-Einstein
macroscopic coherence (BEC) of cavity exciton polaritons.


title: Finding paths of length k in O*(2^k) time

abstract:
  We give a randomized algorithm that determines if a given graph has a simple
path of length at least k in O(2^k poly(n,k)) time.


title:
The dark outside: the density profile of dark matter haloes beyond the
  virial radius

abstract:
  We present an approximation for the average density profile of dark matter
haloes in the LambdaCDM cosmological model, which is accurate to within 10--15%
even for large radial distances from 0.05R_{vir} up to 10R_{vir} for halo
masses ranging from 10^{11.5} to 10^{15.0} h^{-1}M_{Sun}. We propose a modified
form of the Navarro, Frenk & White (NFW) approximation: \rho(r)=\rho_{NFW}(r)+
A (r/R_{vir})^{-1}+B (1+r/R_{vir})^{-1}. This generalized expression, which is
applicable to the external regions of dark matter haloes, only very slightly
affects the density in the inner regions of haloes. The strong correlation
among the different parameters in the model allows us to describe the profile
in terms of just one parameter: the virial mass. We integrate our density
profile to derive the enclosed mass in a sphere of a given radius and compare
it with the NFW results. We find that the NFW underestimates the enclosed mass
by more than 50% at 10R_{vir}, whereas our model reproduces the results from
numerical simulations to within 2% accuracy even at this distance. We also use
this new approximation to study the weak gravitational lensing and to obtain an
analytic expression for the tangential shear. This allows us to quantify the
contribution to the shear from the outer regions of the density profile. For
the first time we calculate the difference between the tangential shear
calculated via the NFW profile and the corresponding result when the external
regions of haloes in cosmological simulations are taken into account. We find a
4% difference for all the mass ranges under study.


title: Multipole Analysis of Kicks in Collision of Binary Black Holes

abstract:
  Thorne and Kidder give expressions which allow for analytical estimates of
the "kick", it i.e. the recoil, produced from asymmetrical gravitational
radiation during the interaction of black holes, or in fact any gravitating
compact bodies. (The Thorne-Kidder formula uses momentum flux calculations
based on the linearized General Relativity of gravitational radiation.) We
specifically treat kicks arising in the binary interaction of equal mass black
holes, when at least one of the black holes has significant spin, a. Such
configurations can produce very large kicks in computational simulations. We
consider both fly-by and quasicircular orbits. For fly-by orbits we find
substantial kicks from those Thorne-Kidder terms which are linear in a. For the
quasi-circular case, we consider in addition the nonlinear contribution
(O(a^2)) to the kicks, and provide a dynamical explanation for such terms.
However, in the cases of maximal kick velocities, the dependence on spin is
largely linear (reproduced in numerical results).


title: Right-handed sneutrino as thermal dark matter

abstract:
  We study an extension of the MSSM with a singlet S with coupling SH1H2 in
order to solve the mu problem as in the NMSSM, and right-handed neutrinos N
with couplings SNN in order to generate dynamically electroweak-scale Majorana
masses. We show how in this model a purely right-handed sneutrino can be a
viable candidate for cold dark matter in the Universe. Through the direct
coupling to the singlet, the sneutrino can not only be thermal relic dark
matter but also have a large enough scattering cross section with nuclei to
detect it directly in near future, in contrast with most of other right-handed
sneutrino dark matter models.


title:
A singular position-dependent mass particle in an infinite potential
  well

abstract:
  We consider an unusual singular position=dependent-mass particle in an
infinite potential well. The corresponding Hamiltonian is mapped through a
point-canonical-transformation and an explicit correspondence between the
target Hamiltonian and a Poschl-Teller type reference Hamiltonian is obtained.
New ordering ambiguity parametric setting are suggested.


title: Mechanical response of active gels

abstract:
  We study a model of an active gel of cross-linked semiflexible filaments with
additional active linkers such as myosin II clusters. We show that the coupling
of the elasticity of the semiflexible filaments to the mechanical properties of
the motors leads to contractile behavior of the gel, in qualitative agreement
with experimental observations. The motors, however, soften the zero frequency
elastic constant of the gel. When the collective motor dynamics is incorporated
in the model, a stiffening of the network at high frequencies is obtained. The
frequency controlling the crossover between low and high frequency network
elasticity is estimated in terms of microscopic properties of motors and
filaments, and can be as low as 10^(-3)Hz.


title:
Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen
  via neutron scattering

abstract:
  Recent investigations of the superconducting iron-arsenide families have
highlighted the role of pressure, be it chemical or mechanical, in fostering
superconductivity. Here we report that CaFe2As2 undergoes a pressure-induced
transition to a non-magnetic, volume "collapsed" tetragonal phase, which
becomes superconducting at lower temperature. Spin-polarized total-energy
calculations on the collapsed structure reveal that the magnetic Fe moment
itself collapses, consistent with the absence of magnetic order in neutron
diffraction.


title: Physics of Strongly coupled Quark-Gluon Plasma

abstract:
  This review cover our current understanding of strongly coupled Quark-Gluon
Plasma (sQGP), especially theoretical progress in (i) explaining the RHIC data
by hydrodynamics, (ii) describing lattice data using electric-magnetic duality;
(iii) understanding of gauge-string duality known as AdS/CFT and its
application for "conformal" plasma. In view of interdisciplinary nature of the
subject, we include brief introduction into several topics "for pedestrians".
Some fundamental questions addressed are: Why is sQGP such a good liquid? What
is the nature of (de)confinement and what do we know about ''magnetic'' objects
creating it? Do they play any important role in sQGP physics? Can we understand
the AdS/CFT predictions, from the gauge theory side? Can they be tested
experimentally? Can AdS/CFT duality help us understand rapid
equilibration/entropy production? Can we work out a complete dynamical "gravity
dual" to heavy ion collisions?


title: In Search of the Largest Velocity Dispersion Galaxies

abstract:
  We present Hobby-Eberly Telescope (HET) observations for galaxies at redshift
z < 0.3 from the Sloan Digital Sky Survey (SDSS) showing large velocity
dispersions while appearing to be single galaxies in HST images. The high
signal-to-noise HET spectra provide more definitive velocity dispersions. The
maximum velocity dispersion we find is 444 km/s. Emission-line widths in QSOs
indicate that black holes can exist with masses exceeding 5 billion solar
masses, implying velocity dispersions greater than 500 km/s by the local black
hole mass - velocity dispersion relationship. This suggests either that QSO
black hole masses are overestimated or that the black hole - bulge relationship
changes at high black hole mass. The latter option is consistent with evidence
that the increase in velocity dispersion with luminosity levels off for the
brightest elliptical galaxies.


title: On the Radiation Problem of High Mass Stars

abstract:
  We use the Azimuthally Symmetric Theory of Gravitation (set-forth in
arXiv:0912.2966 and further advanced in viXra:0911.0025) to argue that massive
stars must be able to form via the accretion disk without much problems.


title:
Deformed Coordinate-Space Hartree-Fock-Bogoliubov Approach to Weakly
  Bound Nuclei and Large Deformations

abstract:
  The coordinate space formulation of the Hartree-Fock-Bogoliubov (HFB) method
enables self-consistent treatment of mean-field and pairing in weakly bound
systems whose properties are affected by the particle continuum space. Of
particular interest are neutron-rich, deformed drip-line nuclei which can
exhibit novel properties associated with neutron skin. To describe such systems
theoretically, we developed an accurate 2D lattice Skyrme-HFB solver {\hfbax}
based on B-splines. Compared to previous implementations, we made a number of
improvements aimed at boosting the solver's performance. These include:
explicit imposition of axiality and space inversion, use of the modified
Broyden's method to solve self-consistent equations, and a partial
parallelization of the code. {\hfbax} has been benchmarked against other HFB
solvers, both spherical and deformed, and the accuracy of the B-spline
expansion was tested by employing the multiresolution wavelet method.
Illustrative calculations are carried out for stable and weakly bound nuclei at
spherical and very deformed shapes, including constrained fission pathways. In
addition to providing new physics insights, {\hfbax} can serve as a useful tool
to assess the reliability and applicability of coordinate-space and
configuration-space HFB solvers, both existing and in development.


title: K-inflationary Power Spectra in the Uniform Approximation

abstract:
  The advent of explicit Dirac-Born-Infeld (DBI) inflationary models within
string theory has drawn renewed interest to the cosmological role of unusual
scalar field dynamics, usually referred to as k-inflation. In this situation,
the standard method used to determine the behavior of cosmological
perturbations breaks down. We present a generic method, based on the uniform
approximation, to analytically derive the power spectra of scalar and tensor
perturbations. For this purpose, a simple hierarchy of parameters, related to
the sound speed of the cosmological fluctuations and its successive
derivatives, is introduced in a k-inflation analogue of the Hubble flow
functions. The scalar spectral index and its running are obtained up to next to
next to leading order for all k-inflationary models. This result relies on the
existence of a well-motivated initial state, which is not trivial in the
present context: having the wavelength of the Fourier mode smaller than the
sonic horizon is indeed not enough and some conditions on the dynamics of the
sound speed are also required. Our method is then applied to various models
encountered in the literature. After deriving a generic slow-roll trajectory
valid for any DBI model, simple formulae for the cosmological observables are
obtained. In particular, the running, as the spectral index, for the so-called
UV and IR brane inflationary models is found to be uniquely determined by the
't Hooft coupling. Finally, the accuracy of these cosmological predictions is
assessed by comparing the analytical approximations with exact numerical
integrations.


title:
Design and Production of Specifically and with High Affinity Reacting
  Peptides

abstract:
  Background: A partially random target selection method was developed to
design and produce affinity reagents (target) to any protein query. It is based
on the recent concept of Proteomic Code (for review see Biro, 2007 [1]) which
suggests that significant number of amino acids in specifically interacting
proteins are coded by partially complementary codons. It means that the 1st and
3rd residues of codons coding many co-locating amino acids are complementary
but the 2nd may but not necessarily complementary: like 5'-AXG-3'/3'-CXT-5'
codon pair, where X is any nucleotide.
  Results: A mixture of 45 residue long, reverse, partially complementary
oligonucleotide sequences (target pool) were synthesized to selected epitopes
of query mRNA sequences. The 2nd codon residues were randomized. The target
oligonucleotide pool was inserted into vectors, expressed and the protein
products were screened for affinity to the query in Bacterial Two-Hybrid
System. The best clones were used for larger-scale protein syntheses and
characterization. It was possible to design and produce specific and with high
affinity reacting (Kd:100 nM) oligopeptide reagents to GAL4 query
oligopeptides.
  Conclusions: Second codon residue randomization is a promising method to
design and produce affinity peptides to any protein sequences. The method has
the potential to be a rapid, inexpensive, high throughput, non-immunoglobulin
based alternative to recent in vivo antibody generating procedures.


title: Comments on the String dual to N=1 SQCD

abstract:
  We study the String dual to N=1 SQCD deformed by a quartic superpotential in
the quark superfields. We present a unified view of the previous results in the
literature and find new exact solutions and new asymptotic solutions. Then we
study the Physics encoded in these backgrounds, giving among other things a
resolution to an old puzzle related to the beta function and a sufficient
criteria for screening. We also extend our results to the SO(Nc) case where we
present a candidate for the Wilson loop in the spinorial representation.
Various aspects of this line of research are critically analyzed.


title: Warped AdS_3 Black Holes

abstract:
  Three dimensional topologically massive gravity (TMG) with a negative
cosmological constant -\ell^{-2} and positive Newton constant G admits an AdS_3
vacuum solution for any value of the graviton mass \mu. These are all known to
be perturbatively unstable except at the recently explored chiral point
\mu\ell=1. However we show herein that for every value of \mu\ell< 3 there are
two other (potentially stable) vacuum solutions given by SL(2,R)x
U(1)-invariant warped AdS_3 geometries, with a timelike or spacelike U(1)
isometry.
  Critical behavior occurs at \mu\ell=3, where the warping transitions from a
stretching to a squashing, and there are a pair of warped solutions with a null
U(1) isometry. For \mu\ell>3, there are known warped black hole solutions which
are asymptotic to warped AdS_3. We show that these black holes are discrete
quotients of warped AdS_3 just as BTZ black holes are discrete quotients of
ordinary AdS_3. Moreover new solutions of this type, relevant to any theory
with warped AdS_3 solutions, are exhibited. Finally we note that the black hole
thermodynamics is consistent with the hypothesis that, for \mu\ell>3, the
warped AdS_3 ground state of TMG is holographically dual to a 2D boundary CFT
with central charges c_R={15(\mu\ell)^2+81\over G\mu((\mu\ell)^2+27)} and
c_L={12 \mu\ell^2\over G((\mu\ell)^2+27)}.


title: A Kirchhoff-like conservation law in Regge calculus

abstract:
  Simplicial lattices provide an elegant framework for discrete spacetimes. The
inherent orthogonality between a simplicial lattice and its circumcentric dual
yields an austere representation of spacetime which provides a conceptually
simple form of Einstein's geometric theory of gravitation. A sufficient
understanding of simplicial spacetimes has been demonstrated in the literature
for spacetimes devoid of all non-gravitational sources. However, this
understanding has not been adequately extended to non-vacuum spacetime models.
Consequently, a deep understanding of the diffeomorphic structure of the
discrete theory is lacking. Conservation laws and symmetry properties are
attractive starting points for coupling matter with the lattice. We present a
simplicial form of the contracted Bianchi identity which is based on the E.
Cartan moment of rotation operator. This identity manifests itself in the
conceptually-simple form of a Kirchhoff-like conservation law. This
conservation law enables one to extend Regge Calculus to non-vacuum spacetimes
and provides a deeper understanding of the simplicial diffeomorphism group.


title: Stability of the Schwarzschild Interior in Loop Quantum Gravity

abstract:
  In recent work, the Schwarzschild interior of a black hole was investigated,
incorporating quantum gravitational modifications due to loop quantum gravity.
The central Schwarzschild singularity was shown to be replaced by a Nariai type
universe. In this brief report we show that this interior solution is stable
with respect to small perturbations, in contrast to the classical Nariai
universe.


title: Can binary mergers produce maximally spinning black holes?

abstract:
  Gravitational waves carry away both energy and angular momentum as binary
black holes inspiral and merge. The relative efficiency with which they are
radiated determines whether the final black hole of mass $M_f$ and spin $S_f$
saturates the Kerr limit ($\chi_f \equiv S_f/M_f^2 \leq 1$). Extrapolating from
the test-particle limit, we propose expressions for $S_f$ and $M_f$ for mergers
with initial spins aligned or anti-aligned with the orbital angular momentum.
We predict the the final spin at plunge for equal-mass non-spinning binaries to
better than 1%, and that equal-mass maximally spinning aligned mergers lead to
nearly maximally spinning final black holes ($\chi_f \simeq 0.9988$). We also
find black holes can always be spun up by aligned mergers provided the mass
ratio is small enough.


title: The Rotating Nuclear Star Cluster in NGC 4244

abstract:
  We present observations of the nuclear star cluster in the nearby edge-on
spiral galaxy NGC 4244 using the Gemini Near-Infrared Integral Field
Spectrograph (NIFS) with laser guide star adaptive optics. From a previous
study of edge-on galaxies, this nuclear star cluster was found to be one of a
sample of clusters that appear flattened along the plane of their host galaxies
disks. Such clusters show evidence for multiple morphological components, with
younger/bluer disk components and older/redder spheroidal components. Our new
observations of NGC 4244 show clear rotation of 30 km/sec within the central 10
pc (0.5") of the cluster. The central velocity dispersion is found to be 28+/-2
km/sec. The multiple stellar populations inferred from the optical colors and
spectra are seen as variations in the CO line strength in the NIFS spectra. The
rotation is clearly detected even in the older, more spheroidal stellar
component. We discuss evidence for similar structures and kinematics in the
nuclear star clusters of other galaxies including M33 and the Milky Way. Our
observations support two possible formation mechanisms: (1) episodic accretion
of gas from the disk directly onto the nuclear star cluster, or (2) episodic
accretion of young star clusters formed in the central part of the galaxy due
to dynamical friction.


title:
Osserman and conformally Osserman manifolds with warped and twisted
  product structure

abstract:
  We characterize Osserman and conformally Osserman Riemannian manifolds with
the local structure of a warped product. By means of this approach we analyze
the twisted product structure and obtain, as a consequence, that the only
Osserman manifolds which can be written as a twisted product are those of
constant curvature.


title:
An order-preserving property of additive invariant for Takesue-type
  reversible cellular automata

abstract:
  We show that, for a fairly large class of reversible, one-dimensional
cellular automata, the set of additive invariants exhibits an algebraic
structure. More precisely, if $f$ and $g$ are one-dimensional, reversible
cellular automata of the kind considered by Takesue, we show that there is a
binary operation on these automata $\vee$ such that $\psi(f)\subseteq
\psi(f\vee g)$, where $\psi(f)$ denotes the set of additive invariants of $f$
and $\subseteq$ denotes the inclusion relation between real subspaces.


title: Minimal atlases of closed contact manifolds

abstract:
  We study the minimal number C(M,\xi) of contact charts that one needs to
cover a closed connected contact manifold (M,\xi). Our basic result is C(M,\xi)
\le \dim M + 1.
  We compute C(M,\xi) for all closed connected contact 3-manifolds:
  C (M,\xi) = 2 if M = S^3 and \xi is tight,
  3 if M = S^3 and \xi is overtwisted or if M = #_k (S^2 \times S^1),
  4 otherwise.
  We also show that on every sphere S^{2n+1} there exists a contact structure
with C(S^{2n+1},\xi) \ge 3.


title:
Structure and Depletion at Fluoro- and Hydro-carbon/Water Liquid/Liquid
  Interfaces

abstract:
  The results of x-ray reflectivity studies of two oil/water (liquid/liquid)
interfaces are inconsistent with recent predictions of the presence of a
vapor-like depletion region at hydrophobic/aqueous interfaces. One of the oils,
perfluorohexane, is a fluorocarbon whose super-hydrophobic interface with water
provides a stringent test for the presence of a depletion layer. The other oil,
heptane, is a hydrocarbon and, therefore, is more relevant to the study of
biomolecular hydrophobicity. These results are consistent with the sub-angstrom
proximity of water to soft hydrophobic materials.


title: Multiple ring nebulae around blue supergiants

abstract:
  In the course of the life of a massive star, wind-wind interaction can give
rise to the formation of circumstellar nebulae which are both predicted and
observed in the nature. We present generic model calculations to predict the
properties of such nebulae for blue supergiants. From stellar evolution
calculations including rotation, we obtain the time dependence of the stellar
wind properties and of the stellar radiation field. These are used as input for
hydro-calculations of the circumstellar medium throughout the star's life.
Here, we present the results for a rapidly rotating 12 solar masses single
star. This star undergoes a blue loop during its post main sequence evolution,
at the onset of which its contraction spins it up close to critical rotation.
Due to the consequent anisotropic mass loss, the blue supergiant wind sweeps up
the preceding slow wind into an hour glass structure. Its collision with the
previously formed spherical red supergiant wind shell forms a short-lived
luminous nebula consisting of two polar caps and a central inner ring. With
time, the polar caps evolve into mid-latitude rings which gradually move toward
the equatorial plane while the central ring is fading. These structures are
reminiscent to the observed nebulae around the blue supergiant Sher 25 and the
progenitor of SN 1987A. The simple model of an hour glass colliding with a
spherical shell retrieves most of the intriguing nebula geometries discovered
around blue supergiants, and suggests them to form an evolutionary sequence.
Our results indicate that binarity is not required to obtain them.


title: Dimensionally Distributed Learning: Models and Algorithm

abstract:
  This paper introduces a framework for regression with dimensionally
distributed data with a fusion center. A cooperative learning algorithm, the
iterative conditional expectation algorithm (ICEA), is designed within this
framework. The algorithm can effectively discover linear combinations of
individual estimators trained by each agent without transferring and storing
large amount of data amongst the agents and the fusion center. The convergence
of ICEA is explored. Specifically, for a two agent system, each complete round
of ICEA is guaranteed to be a non-expansive map on the function space of each
agent. The advantages and limitations of ICEA are also discussed for data sets
with various distributions and various hidden rules. Moreover, several
techniques are also designed to leverage the algorithm to effectively learn
more complex hidden rules that are not linearly decomposable.


title: Weak momentum scattering and the conductivity of graphene

abstract:
  Electrical transport in graphene offers a fascinating parallel to spin
transport in semiconductors including the spin-Hall effect. In the weak
momentum scattering regime the steady-state density matrix contains two
contributions, one linear in the carrier number density $n$ and characteristic
scattering time $\tau$, the other independent of either. In this paper we take
the Liouville equation as our starting point and demonstrate that these two
contributions can be identified with pseudospin conservation and
non-conservation respectively, and are connected in a non-trivial manner by
scattering processes. The scattering term has a distinct form, which is
peculiar to graphene and has important consequences in transport. The
contribution linear in $\tau$ is analogous to the part of the spin density
matrix which yields a steady state spin density, while the contribution
independent of $\tau$, is analogous to the part of the spin density matrix
which yields a steady state spin current. Unlike in systems with spin-orbit
interactions, the $n$ and $\tau$-independent part of the conductivity is
reinforced in the weak momentum scattering regime by scattering between the
conserved and non-conserved pseudospin distributions.


title: Closed String TCFT for Hermitian Calabi-Yau Elliptic Spaces

abstract:
  We describe an explicit action of the prop of the chains on the moduli space
of Riemann surfaces on the Hochschild complex of a Calabi-Yau elliptic space.
One example of such an elliptic space extends the known string topology
operations, for all compact simply-connected manifolds, to a collection indexed
by the de Rham currents on the moduli space. Another example pertains to the
B-model at all genera.


title:
Bulges of disk galaxies at intermediate redshifts.II. Nuclear, disk and
  global colours in the Groth Strip

abstract:
  We analyse colours of the nuclear regions of intermediate redshift disk
galaxies, with the aim of obtaining empirical information of relative ages of
bulges and disks at 0.1 < z < 1.3. We work with an apparent-diameter limited
parent sample of 248 galaxies from the HST Groth Strip Survey. We apply a
conservative criterion to identify bulges and potential precursors of
present-day bulges based on nuclear surface brightness excess above the
exponential profile of the outer parts. We measure bulge colours on wedge
profiles opening on the semi-minor axis, and compare them to disk, and global
galaxy colours. For 60% of galaxies with bulges, the rest-frame nuclear colour
distribution shows a red sequence that is well fit by passive evolution models
of various ages, while the remainder 40% scatters towards bluer colours. In
contrast, galaxies without central brightness excess show typical colours of
star forming population and lack a red sequence. We also see that, as in the
local Universe, most of the minor axis colour profiles are negative (bluer
outward), and fairly gentle, indicating that nuclear colours are not distinctly
different from disk colours. This is corroborated when comparing nuclear,
global and disk colours: these show strong correlations, for any value of the
central brightness prominence of the bulge. Comparison with synthetic models of
red sequence bulge colours suggests that such red bulges have stopped forming
stars at an epoch earlier than ~ 1 Gyr before the observation. The correlation
between nuclear and disk colours and the small colour gradients hints at an
intertwined star formation history for bulges and disks: probably, most of our
red bulges formed in a process in which truncation of star formation in the
bulge did not destroy the disk.


title: Deformations of symmetric simple modular Lie (super)algebras

abstract:
  We say that a~Lie (super)algebra is ``symmetric" if with every root (with
respect to the maximal torus) it has its opposite of the same multiplicity.
Over algebraically closed fields of positive characteristics we describe the
deforms (results of deformations) of all known simple finite-dimensional
symmetric Lie (super)algebras of rank $<9$, except for superizations of the Lie
algebras with ADE root systems.
  The moduli of deformations of any Lie superalgebra constitute a supervariety.
Any infinitesimal deformation given by any odd cocycle is integrable with an
odd parameter running over a~supervariety. All deforms corresponding to odd
cocycles are new. Among new results are classification of the deforms of the
29-dimensional Brown algebra in characteristic 3, of Weisfeiler-Kac algebras
and orthogonal Lie algebras without Cartan matrix in characteristic 2.
  For the Lie (super)algebras considered, all cocycles are integrable, the
deforms corresponding to the weight cocycles are usually linear in the
parameter. Problem: describe isomorphic deforms.
  Appendix: For several modular analogs of complex simple Lie algebras, and
simple Lie algebras indigenous to characteristics 3 and 2, we describe the
space of cohomology with trivial coefficients. We show that the natural
multiplication in this space is very complicated.


title:
Higgs Boson Mass, Sparticle Spectrum and Little Hierarchy Problem in
  Extended MSSM

abstract:
  We investigate the impact of TeV-scale matter belonging to complete
vectorlike multiplets of unified groups on the lightest Higgs boson in the
MSSM. We find that consistent with perturbative unification and electroweak
precision data the mass m_h can be as large as 160 GeV. These extended MSSM
models can also render the little hierarchy problem less severe, but only for
lower values of m_h < 125 GeV. We present estimates for the sparticle mass
spectrum in these models.


title: Fermionic realization of toroidal Lie algebras of classical types

abstract:
  We use fermionic operators to construct toroidal Lie algebras of classical
types, including in particular that of symplectic affine algebras, which is
first realized by fermions.


title: Quark-like particles in dual electromagnetic fields

abstract:
  In a classical field model involving extended dual electromagnetic fields
quark-like particles are shown to have fractional charges and a confining
energy that provides an asymptotically free spherical surface. A suggestion is
made for combining a measure of the confining energy with color in QCD.


title: Consistency Relations for Non-Gaussianity

abstract:
  We investigate consistency relations for non-Gaussianity. We provide a
model-independent dynamical proof for the consistency relation of 3-point
correlation functions from the Hamiltonian and field redefinition. This
relation can be applied to single field inflation, multi-field inflation and
the curvaton scenario. This relation can also be generalized to $n$-point
correlation functions up to arbitrary order in perturbation theory and with
arbitrary number of loops.


title: Agent-based model of competition in a social structure

abstract:
  Indirect competition emerged from the complex organization of human
societies, and knowledge of the existing network topology may aid in developing
effective strategies for success. Here, we propose an agent-based model of
competition with systems co-existing in a `small-world' social network. We show
that within the range of parameter values obtained from the model and empirical
data, the network evolution is highly dependent on $k$, the local parameter
describing the density of neighbors in the network. The model applied to
language death and competition of telecommunication companies show strong
correspondence with empirical data.


title:
Connection between a possible fifth force and the direct detection of
  Dark Matter

abstract:
  If there is a fifth force in the dark sector and dark sector particles
interact non-gravitationally with ordinary matter, quantum corrections
generically lead to a fifth force in the visible sector. We show how the strong
experimental limits on fifth forces in the visible sector constrain the direct
detection cross section, and the strength of the fifth force in the dark
sector. If the latter is comparable to gravity, the spin-independent direct
detection cross section must typically be <~ 10^{-55} cm^2. The anomalous
acceleration of ordinary matter falling towards dark matter is also
constrained: \eta_{OM-DM} <~ 10^{-8}.


title: Charmless hadronic $B$ and $B_s$ decays in perturbative QCD approach

abstract:
  We review the perturbative QCD approach study of hadronic B decays. Utilizing
the constrained parameters in these well measured decay channels, we study most
of the possible charmless $B_s \to PP$, $PV$ and $VV$ decay channels in the
perturbative QCD approach. In addition to the branching ratios and CP
asymmetries, we also give predictions to the polarization fractions of the
vector meson final states. The size of SU(3) breaking effect is also discussed.
These predictions can be tested by the future LHCb experiment.


title: On 3-manifolds with locally-standard (Z_2)^3-actions

abstract:
  As a generalization of Davis-Januszkiewicz theory, there is an essential link
between locally standard $(\Z_2)^n$-actions (or $T^n$-actions) actions and nice
manifolds with corners, so that a class of nicely behaved equivariant
cut-and-paste operations on locally standard actions can be carried out in step
on nice manifolds with corners. Based upon this, we investigate what kinds of
closed manifolds admit locally standard $(\Z_2)^n$-actions; especially for the
3-dimensional case.
  Suppose $M$ is an orientable closed connected 3-manifold. When
$H_1(M;\Z_2)=0$, it is shown that $M$ admits a locally standard
$(\Z_2)^3$-action if and only if $M$ is homeomorphic to a connected sum of 8
copies of some $\Z_2$-homology sphere $N$, and if further assuming $M$ is
irreducible, then $M$ must be homeomorphic to $S^3$. In addition, the argument
is extended to rational homology 3-sphere $M$ with $H_1(M;\Z_2) \cong \Z_2$ and
an additional assumption that the $(\Z_2)^3$-action has a fixed point.


title: Transport and Quantum Walk of Nonclassical Light in Coupled Waveguides

abstract:
  We study the transport and quantum walk of nonclassical light in an array of
coupled waveguides which have novel properties like very low decoherence and
thus making them ideal for storage of quantum information. We show how
squeezing gets turned over from one waveguide to another. We further show how
input nonclassical light can generate entanglement among different waveguides.
Our results involve both first quantization due to array structure and second
quantization due to the quantum nature of fields and can also be used to
discuss the Talbot effect in the quantum regime.


title:
Relationship among Phenotypic Plasticity, Genetic and Epigenetic
  Fluctuations, Robustness, and Evolovability; Waddington's Legacy revisited
  under the Spirit of Einstein

abstract:
  Questions on possible relationship between phenotypic plasticity and
evolvability, as well as that between robustness and evolution have been
addressed over decades in the field of evolution-development. By introducing an
evolutionary stability assumption on the distribution of phenotype and
genotype, we establish quantitative relationships on plasticity, phenotypic
fluctuations, and evolvability. Derived are proportionality among plasticity as
a responsiveness of phenotype against environmental change, variances of
phenotype fluctuations of genetic and developmental origins, and evolution
speed. Confirmation of the relationships is given by numerical experiments of a
gene expression dynamics model with an evolving transcription network, whereas
verifications by laboratory evolution experiments are also discussed. These
results provide quantitative formulation on canalization and genetic
assimilation, in terms of fluctuations of gene expression levels.


title: Sharp Bounds for Optimal Decoding of Low Density Parity Check Codes

abstract:
  Consider communication over a binary-input memoryless output-symmetric
channel with low density parity check (LDPC) codes and maximum a posteriori
(MAP) decoding. The replica method of spin glass theory allows to conjecture an
analytic formula for the average input-output conditional entropy per bit in
the infinite block length limit. Montanari proved a lower bound for this
entropy, in the case of LDPC ensembles with convex check degree polynomial,
which matches the replica formula. Here we extend this lower bound to any
irregular LDPC ensemble. The new feature of our work is an analysis of the
second derivative of the conditional input-output entropy with respect to
noise. A close relation arises between this second derivative and correlation
or mutual information of codebits. This allows us to extend the realm of the
interpolation method, in particular we show how channel symmetry allows to
control the fluctuations of the overlap parameters.


title: Quark-Hadron Phase Transitions in Brane-World Cosmologies

abstract:
  When the universe was about 10 $\mu $seconds old, a first order cosmological
quark - hadron phase transition occurred at a critical temperature of around
200 MeV. In this work, we study the quark-hadron phase transition in the
context of brane-world cosmologies, in which our Universe is a three-brane
embedded in a five-dimensional bulk, and within an effective model of QCD. We
analyze the evolution of the physical quantities, relevant for the physical
description of the early universe, namely, the energy density, temperature and
scale factor, before, during, and after the phase transition. To study the
cosmological dynamics and evolution we use both analytical and numerical
methods. In particular, due to the high energy density in the early Universe,
we consider in detail the specific brane world model case of neglecting the
terms linearly proportional to the energy density with respect to the quadratic
terms. A small brane tension and a high value of the dark radiation term tend
to decrease the effective temperature of the quark-gluon plasma and of the
hadronic fluid, respectively, and to significantly accelerate the transition to
a pure hadronic phase. By assuming that the phase transition may be described
by an effective nucleation theory, we also consider the case where the Universe
evolved through a mixed phase with a small initial supercooling and
monotonically growing hadronic bubbles.


title: Spin Field Effect Transistors with Ultracold Atoms

abstract:
  We propose a method of constructing cold atom analogs of the spintronic
device known as the Datta-Das transistor (DDT), which despite its seminal
conceptual role in spintronics, has never been successfully realized with
electrons. We propose two alternative schemes for an atomic DDT, both of which
are based on the experimental setup for tripod stimulated Raman adiabatic
passage. Both setups involve atomic beams incident on a series of laser fields
mimicking the relativistic spin orbit coupling for electrons that is the
operating mechanism of the DDT.

categories: cond-mat.mes-hall cond-mat.other physics.atom-ph quant-ph


title:
Effect of macromolecular crowding on the rate of diffusion-limited
  enzymatic reaction

abstract:
  The cytoplasm of a living cell is crowded with several macromolecules of
different shapes and sizes. Molecular diffusion in such a medium becomes
anomalous due to the presence of macromolecules and diffusivity is expected to
decrease with increase in macromolecular crowding. Moreover, many cellular
processes are dependent on molecular diffusion in the cell cytosol. The
enzymatic reaction rate has been shown to be affected by the presence of such
macromolecules. A simple numerical model is proposed here based on percolation
and diffusion in disordered systems to study the effect of macromolecular
crowding on the enzymatic reaction rates. The model explains qualitatively some
of the experimental observations.


title: Signatures of Non-Gaussianity in the Curvaton Model

abstract:
  We discuss the signatures of non-Gaussianity in the curvaton model where the
potential includes also a non-quadratic term. In such a case the non-linearity
parameter f_NL can become very small, and we show that non-Gaussianity is then
encoded in the non-reducible non-linearity parameter g_NL of the trispectrum,
which can be very large. Thus the place to look for the non-Gaussianity in the
curvaton model may be the trispectrum rather than the bispectrum. We also show
that g_NL measures directly the deviation of the curvaton potential from the
purely quadratic form. While g_NL depends on the strength of the non-quadratic
terms relative to the quadratic one, we find that for reasonable cases roughly
g_NL\sim O(-10^4)-O(-10^5), which are values that may well be accessible by
future observations.


title:
Core-collapse supernovae in low-metallicity environments and future
  all-sky transient surveys

abstract:
  Aims: Massive stars in low-metallicity environments may produce exotic
explosions such as long-duration gamma-ray bursts and pair-instability
supernovae when they die as core-collapse supernovae (CCSNe). Here we determine
the feasibility of searching for these CCSNe in metal-poor dwarf galaxies using
various survey strategies. Methods: We determine oxygen abundances and
star-formation rates for all spectroscopically typed star-forming galaxies in
the Sloan Digital Sky Survey, Data Release 5, within z = 0.04. We then estimate
the CCSN rates for sub-samples of galaxies with differing upper-metallicity
limits. Using Monte-Carlo simulations we then predict the fraction of these
CCSNe that we can expect to detect using different survey strategies. Results:
Using a single 2m telescope (with a standard CCD camera) search we predict a
detection rate of ~1.3 CCSNe/yr in galaxies with metallicities below 12 +
log(O/H) < 8.2 which are within a volume that will allow detailed follow-up
with 4m and 8m telescopes (z = 0.04). With a network of seven 2m telescopes we
estimate ~9.3 CCSNe/yr could be found, although this would require more than
1,000 hrs of telescope time allocated to the network. Within the same radial
distance, a volume-limited search in the future Pan-STARRS PS1 all-sky survey
should uncover 12.5 CCSNe/yr in low-metallicity galaxies. Over a period of a
few years this would allow a detailed comparison of their properties. We then
extend our calculations to determine the total numbers of CCSNe that can
potentially be found in magnitude-limited surveys with PS1 (24,000/yr, within z
< 0.6), PS4 (69,000/yr, within z < 0.8) and LSST (160,000/yr, within z < 0.9)
surveys.


title:
Structure and Magnetism of HoBaCo2O5+delta Layered Cobaltites with
  0.02<delta<0.22

abstract:
  In this paper we have studied, by means of high-resolution neutron powder
diffraction and magnetic susceptibility, the structural and magnetic features
of selected samples of the HoBaCo2O5+delta layered cobaltite in the low oxygen
content range (0.02<delta<0.22). The results shows a strong antiferromagnetic
contribution at room temperature coupled to an intermediate spin state of the
Co3+ ions.


title: Gravitational waves and dragging effects

abstract:
  Linear and rotational dragging effects of gravitational waves on local
inertial frames are studied in purely vacuum spacetimes. First the linear
dragging caused by a simple cylindrical pulse is investigated. Surprisingly
strong transversal effects of the pulse are exhibited. The angular momentum in
cylindrically symmetric spacetimes is then defined and confronted with some
results in literature. In the main part, the general procedure is developed for
studying weak gravitational waves with translational but not axial symmetry
which can carry angular momentum. After a suitable averaging the rotation of
local inertial frames due to such rotating waves can be calculated explicitly
and illustrated graphically. This is done in detail in the accompanying paper.
Finally, the rotational dragging is given for strong cylindrical waves
interacting with a rotating cosmic string with a small angular momentum.