title:
Determination of magnetic order of the rare-earth ions in multiferroic
  TbMn2O5

abstract:
  We have employed resonant x-ray magnetic scattering to specifically probe the
magnetic order of the rare-earth ions in multiferroic $\mathrm{TbMn_2O_5}$. Two
energy resonances were observed, one originated from the E1-E1 dipolar
transition and the other from the E2-E2 quadrupolar transition. These
resonances directly probe the valence 5d band and the partially occupied 4f
band, respectively. First, full polarization analysis, which is a measurement
of the scattered polarization as a function of incident polarization, confirmed
a spin polarization of the terbium valence states (probed by the E1-E1
transition) by the $\mathrm{Mn^{4+}}$ spin density in the commensurate phase.
Second, full polarization analysis data were collected in the low-temperature
incommensurate and commensurate phases when tuned to the E2-E2 resonance. By
employing a least-squares fitting procedure, the spin orientations of the
terbium ion sublattice were refined.


title:
Triangleland. I. Classical dynamics with exchange of relative angular
  momentum

abstract:
  In Euclidean relational particle mechanics, only relative times, relative
angles and relative separations are meaningful. Barbour--Bertotti (1982) theory
is of this form and can be viewed as a recovery of (a portion of) Newtonian
mechanics from relational premises. This is of interest in the absolute versus
relative motion debate and also shares a number of features with the
geometrodynamical formulation of general relativity, making it suitable for
some modelling of the problem of time in quantum gravity. I also study
similarity relational particle mechanics (`dynamics of pure shape'), in which
only relative times, relative angles and {\sl ratios of} relative separations
are meaningful. This I consider firstly as it is simpler, particularly in 1 and
2 d, for which the configuration space geometry turns out to be well-known,
e.g. S^2 for the `triangleland' (3-particle) case that I consider in detail.
Secondly, the similarity model occurs as a sub-model within the Euclidean
model: that admits a shape--scale split. For harmonic oscillator like
potentials, similarity triangleland model turns out to have the same
mathematics as a family of rigid rotor problems, while the Euclidean case turns
out to have parallels with the Kepler--Coulomb problem in spherical and
parabolic coordinates. Previous work on relational mechanics covered cases
where the constituent subsystems do not exchange relative angular momentum,
which is a simplifying (but in some ways undesirable) feature paralleling
centrality in ordinary mechanics. In this paper I lift this restriction. In
each case I reduce the relational problem to a standard one, thus obtain
various exact, asymptotic and numerical solutions, and then recast these into
the original mechanical variables for physical interpretation.


title: AE Aquarii: The first white dwarf in the family of spin-powered pulsars

abstract:
  Simulation of Doppler H-alpha tomogram of the nova-like star AE Aquarii
suggests that the dipole magnetic moment of the white dwarf is close to 1.5E+34
G cm^3. This is consistent with the lower limit to the magnetic field strength
of the white dwarf derived from observations of circularly polarized optical
emission of the system. The rapid braking of the white dwarf and the nature of
pulsing hard X-ray emission recently detected with SUZAKU space telescope under
these conditions can be explained in terms of spin-powered pulsar mechanism. A
question about the origin of strongly magnetized white dwarf in the system
remains, however, open. Possible evolutionary tracks of AE Aquarii are briefly
discussed.


title: Density functional theory and quantum computation

abstract:
  This paper establishes the applicability of density functional theory methods
to quantum computing systems. We show that ground-state and time-dependent
density functional theory can be applied to quantum computing systems by
proving the Hohenberg-Kohn and Runge-Gross theorems for a fermionic
representation of an N qubit system. As a first demonstration of this approach,
time-dependent density functional theory is used to determine the minimum
energy gap Delta(N) arising when the quantum adiabatic evolution algorithm is
used to solve instances of the NP-Complete problem MAXCUT. It is known that the
computational efficiency of this algorithm is largely determined by the large-N
scaling behavior of Delta(N), and so determining this behavior is of
fundamental significance. As density functional theory has been used to study
quantum systems with N ~ 1000 interacting degrees of freedom, the approach
introduced in this paper raises the realistic prospect of evaluating the gap
Delta(N) for systems with N ~ 1000 qubits. Although the calculation of Delta(N)
serves to illustrate how density functional theory methods can be applied to
problems in quantum computing, the approach has a much broader range and shows
promise as a means for determining the properties of very large quantum
computing systems.


title: Minkowski Sum Selection and Finding

abstract:
  For the \textsc{Minkowski Sum Selection} problem with linear objective
functions, we obtain the following results: (1) optimal $O(n\log n)$ time
algorithms for $\lambda=1$; (2) $O(n\log^2 n)$ time deterministic algorithms
and expected $O(n\log n)$ time randomized algorithms for any fixed $\lambda>1$.
For the \textsc{Minkowski Sum Finding} problem with linear objective functions
or objective functions of the form
  $f(x,y)=\frac{by}{ax}$, we construct optimal $O(n\log n)$ time algorithms for
any fixed $\lambda\geq 1$.


title:
The stellar content of the Hamburg/ESO survey. V. The metallicity
  distribution function of the Galactic halo

abstract:
  We determine the metallicity distribution function (MDF) of the Galactic halo
by means of a sample of 1638 metal-poor stars selected from the Hamburg/ESO
objective-prism survey (HES). The sample was corrected for minor biases
introduced by the strategy for spectroscopic follow-up observations of the
metal-poor candidates, namely "best and brightest stars first". [...] We
determined the selection function of the HES, which must be taken into account
for a proper comparison between the HES MDF with MDFs of other stellar
populations or those predicted by models of Galactic chemical evolution. The
latter show a reasonable agreement with the overall shape of the HES MDF for
[Fe/H] > -3.6, but only a model of Salvadori et al. (2007) with a critical
metallicity for low-mass star formation of Z_cr = 10^{-3.4} * Z_Sun reproduces
the sharp drop at [Fe/H] ~-3.6 present in the HES MDF. [...] A comparison of
the MDF of Galactic globular clusters and of dSph satellites to the Galaxy
shows qualitative agreement with the halo MDF, derived from the HES, once the
selection function of the latter is included. However, statistical tests show
that the differences between these are still highly significant. [ABSTRACT
ABRIDGED]


title:
On the essential spectrum of Nadirashvili-Martin-Morales minimal
  surfaces

abstract:
  We show that the spectrum of a complete submanifold properly immersed into a
ball of a Riemannian manifold is discrete, provided the norm of the mean
curvature vector is sufficiently small. In particular, the spectrum of a
complete minimal surface properly immersed into a ball of $\mathbb{R}^{3}$ is
discrete. This gives a positive answer to a question of Yau.


title:
Measurement of time dependent CP asymmetry parameters in B0 meson decays
  to omega K0S, eta'K0, and pi0K0S

abstract:
  We present measurements of the time-dependent CP-violation parameters S and C
in the decays omega K0S, eta'K0, reconstructed as eta'K0S and eta'K0L, and
pi0K0S. The data sample corresponds to the full BABAR dataset of 467 x 10^6 BB
pairs produced at the PEP-II asymmetric-energy e+e- collider at the Stanford
Linear Accelerator Center. The results are S_{omega K0S} = 0.55^{+0.26}_{-0.29}
+/- 0.02, C_{omega K0S} = -0.52^{+0.22}_{-0.20} +/- 0.03, S_{eta' K0} = 0.57
+/- 0.08 +/- 0.02, C_{eta' K0} = -0.08 +/- 0.06 +/- 0.02, S_{pi0 K0S} = 0.55
+/- 0.20 +/- 0.03, and C_{pi0 K0S} = 0.13 +/- 0.13 +/- 0.03, where the first
errors are statistical and the second systematic. These results are consistent
with our previous measurements and the world average of sin2beta measured in B0
-> J/psi K0S.


title:
Application of a New Non-Linear Least Squares Velocity Curve Analysis
  Technique for Spectroscopic Binary Stars

abstract:
  Using measured radial velocity data of nine double lined spectroscopic binary
systems NSV 223, AB And, V2082 Cyg, HS Her, V918 Her, BV Dra, BW Dra, V2357
Oph, and YZ Cas, we find corresponding orbital and spectroscopic elements via
the method introduced by Karami & Mohebi (2007a) and Karami & Teimoorinia
(2007). Our numerical results are in good agreement with those obtained by
others using more traditional methods.


title:
On the connected components of the conjugacy class of projectors on $
  \ell_p\oplus\ell_q $

abstract:
  We characterize the projectors $ P $ on a Banach space $ E $ having the
property of being connected to all the others projectors obtained as a
conjugation of $ P $. Using this characterization we show an example of Banach
space where the conjugacy class of a projector splits into several
path-connected components, and describe the conjugacy classes of projectors
onto subspaces of $ \ell_p\oplus\ell_q $ with $ p\neq q $.


title: Amdahl's and Gustafson-Barsis laws revisited

abstract:
  The paper presents a simple derivation of the Gustafson-Barsis law from the
Amdahl's law. In the computer literature these two laws describing the speedup
limits of parallel applications are derived separately. It is shown, that
treating the time of the execution of the sequential part of the application as
a constant, in few lines the Gustafson-Barsis law can be obtained from the
Amdahl's law and that the popular claim, that Gustafson-Barsis law overthrows
Amdahl's law is a mistake.


title:
Local Structure and It's Effect on The Ferromagnetic Properties of
  La$_{0.5}$Sr$_{0.5}$CoO$_3$ thin films}

abstract:
  We have used high-resolution Extended X-ray Absorption Fine-Structure and
diffraction techniques to measure the local structure of strained
La$_{0.5}$Sr$_{0.5}$CoO$_3$ films under compression and tension. The lattice
mismatch strain in these compounds affects both the bond lengths and the bond
angles, though the larger effect on the bandwidth is due to the bond length
changes. The popular double exchange model for ferromagnetism in these
compounds provides a correct qualitative description of the changes in Curie
temperature $T_C$, but quantitatively underestimates the changes. A microscopic
model for ferromagnetism that provides a much stronger dependence on the
structural distortions is needed.


title: The group of symmetries of the Tower of Hanoi graph

abstract:
  I prove that the group of symmetries of the Tower of Hanoi graph with k pegs
and n disks, denoted H_n^k, is isomorphic to the group of permutations of k
elements, S_k, for all k greater than or equal to 3 and positive n.


title: On the relation between native geometry and conformational plasticity

abstract:
  In protein folding the term plasticity refers to the number of alternative
folding pathways encountered in response to free energy perturbations such as
those induced by mutation. Here we explore the relation between folding
plasticity and a gross, generic feature of the native geometry, namely, the
relative number of local and non-local native contacts. The results from our
study, which is based on Monte Carlo simulations of simple lattice proteins,
show that folding to a structure that is rich in local contacts is considerably
more plastic than folding to a native geometry characterized by having a very
large number of long-range contacts (i.e., contacts between amino acids that
are separated by more than 12 units of backbone distance). The smaller folding
plasticity of `non-local' native geometries is probably a direct consequence of
their higher folding cooperativity that renders the folding reaction more
robust against single- and multiple-point mutations.


title:
Sector and Sphere: Towards Simplified Storage and Processing of Large
  Scale Distributed Data

abstract:
  Cloud computing has demonstrated that processing very large datasets over
commodity clusters can be done simply given the right programming model and
infrastructure. In this paper, we describe the design and implementation of the
Sector storage cloud and the Sphere compute cloud. In contrast to existing
storage and compute clouds, Sector can manage data not only within a data
center, but also across geographically distributed data centers. Similarly, the
Sphere compute cloud supports User Defined Functions (UDF) over data both
within a data center and across data centers. As a special case, MapReduce
style programming can be implemented in Sphere by using a Map UDF followed by a
Reduce UDF. We describe some experimental studies comparing Sector/Sphere and
Hadoop using the Terasort Benchmark. In these studies, Sector is about twice as
fast as Hadoop. Sector/Sphere is open source.


title: Left invariant complex structures on U(2) and SU(2)xSU(2) revisited

abstract:
  We compute the torsion-free linear maps from the Lie algebra su(2) into
itself, deduce a new determination of the integrable complex structures and
their equivalence classes under the action of the automorphism group for u(2)
and su(2)xsu(2), and prove that in both cases the set of complex structures is
a differentiable manifold. u(2)x u(2), su(2)^N and u(2)^N are also considered.
Extensions of complex structures from u(2) to su(2)xsu(2) are studied, local
holomorphic charts given, and attention is paid to what representations of u(2)
we can get from a substitute to the regular representation on a space of
holomorphic functions for the complex structure.


title: Cosmological equivalence principle and the weak-field limit

abstract:
  The strong equivalence principle is extended in application to averaged
dynamical fields in cosmology to include the role of the average density in the
determination of inertial frames. The resulting cosmological equivalence
principle is applied to the problem of synchronisation of clocks in the
observed universe. Once density perturbations grow to give density contrasts of
order one on scales of tens of megaparsecs, the integrated deceleration of the
local background regions of voids relative to galaxies must be accounted for in
the relative synchronisation of clocks of ideal observers who measure an
isotropic cosmic microwave background. The relative deceleration of the
background can be expected to represent a scale in which weak-field Newtonian
dynamics should be modified to account for dynamical gradients in the Ricci
scalar curvature of space. This acceleration scale is estimated using the
best-fit nonlinear bubble model of the universe with backreaction. At redshifts
z < 0.25 the scale is found to coincide with the empirical acceleration scale
of modified Newtonian dynamics. At larger redshifts the scale varies in a
manner which is likely to be important for understanding dynamics of galaxy
clusters, and structure formation. Although the relative deceleration,
typically of order 10^{-10} m/s^2, is small, when integrated over the lifetime
of the universe it amounts to an accumulated relative difference of 38% in the
rate of average clocks in galaxies as compared to volume-average clocks in the
emptiness of voids. A number of foundational aspects of the cosmological
equivalence principle are also discussed, including its relation to Mach's
principle, the Weyl curvature hypothesis and the initial conditions of the
universe.


title:
Progress in the Understanding of the Fluctuating Lattice Boltzmann
  Equation

abstract:
  We give a brief account of the development of methods to include thermal
fluctuations into lattice Boltzmann algorithms. Emphasis is put on our recent
work (Phys. Rev. E 76, 036704 (2007)) which provides a clear understanding in
terms of statistical mechanics.


title: The Unique Horizontal Symmetry of Leptons

abstract:
  There is a group-theoretical connection between fermion mixing matrices and
minimal horizontal symmetry groups. Applying this connection to the
tri-bimaximal neutrino mixing matrix, we show that the minimal horizontal
symmetry group for leptons is uniquely $S_4$, the permutation group of four
objects.


title: Survey on Affine Spheres

abstract:
  We give a survey of the theory of affine spheres, emphasizing the convex
cases and relationsships to Monge-Ampere equations and geometric structures on
manifolds.


title: Representation theory of mv-algebras

abstract:
  In this paper we develop a general representation theory for mv-algebras. We
furnish the appropriate categorical background to study this problem. Our guide
line is the theory of classifying topoi of coherent extensions of universal
algebra theories. Our main result corresponds, in the case of mv-algebras and
mv-chains, to the representation of commutative rings with unit as rings of
global sections of sheaves of local rings. \emph{We prove that any mv-algebra
is isomorphic to the mv-algebra of all global sections of a sheaf of mv-chains
on a compact topological space}. This result is intimately related to
McNaughton's theorem, and we explain why our representation theorem can be
viewed as a vast generalization of McNaughton's. On spite of the language
utilized in this abstract, we wrote this paper in a way that, we hope, could be
read without much acquaintance with either sheaf theory or mv-algebra theory.


title: On the Statistics of Lattice Polytopes

abstract:
  We use the notions of reflexivity and of reflexive dimensions in order to
introduce probability measures for lattice polytopes and initiate the
investigation of their statistical properties. Examples of applications to
discrete geometry include a study of randomness of self-duality of reflexive
polytopes and implications for expectation values of the numbers of such
polytopes in higher dimensions. We also discuss enumeration problems and
related algorithms and point out interesting open problems. In this context we
define the notion of IP-confined polytopes. Our new results include the list of
IP-simplices in 3 dimensions that are not IP-confined. The main motivation for
the study of these issues comes from applications in algebraic geometry and
string theory.


title: The history of star formation and mass assembly in early-type galaxies

abstract:
  We define a volume limited sample of over 14,000 early-type galaxies (ETGs)
selected from data release six of the Sloan Digital Sky Survey. The density of
environment of each galaxy is robustly measured. By comparing narrow band
spectral line indices with recent models of simple stellar populations (SSPs)
we investigate trends in the star formation history as a function of galaxy
mass (velocity dispersion), density of environment and galactic radius. We find
that age, metallicity and alpha-enhancement all increase with galaxy mass and
that field ETGs are younger than their cluster counterparts by ~2 Gyr. We find
negative radial metallicity gradients for all masses and environments, and
positive radial age gradients for ETGs with velocity dispersion over 180 km/s.
Our results are qualitatively consistent with a relatively simple picture for
ETG evolution in which the low-mass halos accreted by a proto-ETG contained not
only gas but also a stellar population. This fossil population is
preferentially found at large radii in massive ETGs because the stellar
accretions were dissipationless. We estimate that the typical, massive ETG
should have been assembled at z < 3.5. The process is similar in the cluster
and the field but occurred earlier in dense environments.


title: Particle production and nonlinear diffusion in relativistic systems

abstract:
  The short parton production phase in high-energy heavy-ion collisions is
treated analytically as a nonlinear diffusion process. The initial buildup of
the rapidity density distributions of produced charged hadrons within tau_p =
0.25 fm/c occurs in three sources during the colored partonic phase. In a
two-step approach, the subsequent diffusion in pseudorapidity space during the
interaction time of tau_int = 7-10 fm/c (mean duration of the collision) is
essentially linear as expressed in the Relativistic Diffusion Model (RDM) which
yields excellent agreement with the data at RHIC energies, and allows for
predictions at LHC energies. Results for d+Au are discussed in detail.


title: The Magnetosphere of Oscillating Neutron Stars in General Relativity

abstract:
  Just as a rotating magnetised neutron star has material pulled away from its
surface to populate a magnetosphere, a similar process can occur as a result of
neutron-star pulsations rather than rotation. This is of interest in connection
with the overall study of neutron star oscillation modes but with a particular
focus on the situation for magnetars. Following a previous Newtonian analysis
of the production of a force-free magnetosphere in this way Timokhin et al.
(2000), we present here a corresponding general-relativistic analysis. We give
a derivation of the general relativistic Maxwell equations for small-amplitude
arbitrary oscillations of a non-rotating neutron star with a generic magnetic
field and show that these can be solved analytically under the assumption of
low current density in the magnetosphere. We apply our formalism to toroidal
oscillations of a neutron star with a dipole magnetic field and find that the
low current density approximation is valid for at least half of the oscillation
modes, similarly to the Newtonian case. Using an improved formula for the
determination of the last closed field line, we calculate the energy losses
resulting from toroidal stellar oscillations for all of the modes for which the
size of the polar cap is small. We find that general relativistic effects lead
to shrinking of the size of the polar cap and an increase in the energy density
of the outflowing plasma. These effects act in opposite directions but the net
result is that the energy loss from the neutron star is significantly smaller
than suggested by the Newtonian treatment.


title: Exact results and open questions in first principle functional RG

abstract:
  Some aspects of the functional RG (FRG) approach to pinned elastic manifolds
(of internal dimension $d$) at finite temperature $T>0$ are reviewed and
reexamined in this much expanded version of [Europhys. Lett. {\bf 76} 457
(2006)]. The particle limit $d=0$ provides a test for the theory: there the FRG
is equivalent to the decaying Burgers equation, with viscosity $\nu \sim T$ -
both being formally irrelevant. Analogy between Kolmogorov scaling and FRG
cumulant scaling is discussed. Next we prove that the FRG function $R(u)$ and
higher cumulants defined from the field theory can be obtained {\it for any
$d$} from moments of a renormalized potential defined in an sliding harmonic
well. This allows to measure the fixed point function $R(u)$ in numerics and
experiments. In $d=0$ the beta function (of the inviscid limit) is obtained
from first principles to four loop. For Sinai model (uncorrelated Burgers
initial velocities) the ERG hierarchy can be solved and the exact function
$R(u)$ is obtained. Connections to exact solutions for the statistics of shocks
in Burgers and to ballistic aggregation is detailed. A relation is established
between the size distribution of shocks and the one for droplets. A droplet
solution to the ERG functional hierarchy is found for any $d$, and the form of
$R(u)$ in the thermal boundary layer is related to droplet probabilities. These
being known for the $d=0$ Sinai model the function $R(u)$ is obtained there at
any $T$. Consistency of the $\epsilon=4-d$ expansion in one and two loop FRG is
studied from first principles, and connected to shock and droplet relations
which could be tested in numerics.


title: Monotone images of Cremer Julia sets

abstract:
  We show that if $P$ is a quadratic polynomial with a fixed Cremer point and
Julia set $J$, then for any monotone map $\ph:J\to A$ from $J$ onto a locally
connected continuum $A$, $A$ is a single point.


title: K-theoretic exceptional collections at roots of unity

abstract:
  Using cyclotomic specializations of the equivariant $K$-theory with respect
to a torus action we derive congruences for discrete invariants of exceptional
objects in derived categories of coherent sheaves on a class of varieties that
includes Grassmannians and smooth quadrics. For example, we prove that if
$X={\Bbb P}^{n_1-1}\times...\times{\Bbb P}^{n_k-1}$, where $n_i$'s are powers
of a fixed prime number $p$, then the rank of an exceptional object on $X$ is
congruent to $\pm 1$ modulo $p$.


title:
Amplitude equations for weakly nonlinear two-scale perturbations of free
  hydromagnetic convective regimes in a rotating layer

abstract:
  Weakly non-linear stability of regimes of free hydromagnetic thermal
convection in a rotating horizontal layer with free electrically conducting
boundaries is considered in the Boussinesq approximation. Perturbations are
supposed to involve large spatial and temporal scales. Applying methods for
homogenisation of parabolic equations, we derive the system of amplitude
equations governing the evolution of perturbations under the assumption that
the alpha-effect is insignificant in the leading order. The amplitude equations
involve the operators of anisotropic combined eddy diffusivity correction and
advection. The system is qualitatively different from the system of mean-field
equations for large-scale perturbations of forced convective hydromagnetic
regimes. It is mixed: equations for the mean magnetic perturbation are
evolutionary, all the rest involve neither time derivatives, nor the molecular
diffusivity operator.


title: Isospin Dependence of Incomplete Fusion Reactions at 25 Mev/a

abstract:
  40Ca+40,48Ca,46Ti reactions at 25 MeV/A have been studied using the 4p
CHIMERA detector. An isospin effect on the competition between incomplete
fusion and dissipative binary reaction mechanisms has been observed. The
probability of producing a compound system is observed to be lower in the case
of N=Z colliding systems as compared to the case of reactions induced on the
more neutron rich 48Ca target. Predictions based on CoMD-II calculations show
that the competition between fusion-like and dissipative reactions, for the
selected centrality, can strongly constraint the parameterization of symmetry
energy and its density dependence in the nuclear equation of state.


title:
Nuclear magnetic relaxation and superfluid density in Fe-pnictide
  superconductors: An anisotropic \pm s-wave scenario

abstract:
  We discuss the nuclear magnetic relaxation rate and the superfluid density
with the use of the effective five-band model by Kuroki et al. [Phys. Rev.
Lett. 101, 087004 (2008)] in Fe-based superconductors. We show that a
fully-gapped anisotropic \pm s-wave superconductivity consistently explains
experimental observations. In our phenomenological model, the gaps are assumed
to be anisotropic on the electron-like \beta Fermi surfaces around the M point,
where the maximum of the anisotropic gap is about four times larger than the
minimum.


title:
On canonical transformations between equivalent Hamiltonian formulations
  of General Relativity

abstract:
  Two Hamiltonian formulations of General Relativity, due to Pirani, Schild and
Skinner (Phys. Rev. 87, 452, 1952) and Dirac (Proc. Roy. Soc. A 246, 333,
1958), are considered. Both formulations, despite having different expressions
for constraints, allow one to derive four-dimensional diffeomorphism
invariance. The relation between these two formulations at all stages of the
Dirac approach to the constrained Hamiltonian systems is analyzed. It is shown
that the complete sets of their phase-space variables are related by a
transformation which satisfies the ordinary condition of canonicity known for
unconstrained Hamiltonians and, in addition, converts one total Hamiltonian
into another, thus preserving form-invariance of generalized Hamiltonian
equations for constrained systems.


abstract:
  Three-photon annihilation of the electron-positron pairs (= $(e^{-},
e^{+})-$pairs) is considered in the electron rest frame. The energy of the
incident positron can be arbitrary. The analytical expression for the
cross-section of three-photon annihilation of the $(e^{-},e^{+})-$pair has been
derived and investigated.


title: Dynamical symmetry breaking and the cosmological constant problem

abstract:
  We outline a program with the potential to solve both the cosmological
constant and quantum gravity problems within a single, comprehensive framework,
one that is formulated entirely in four spacetime dimensions. The program is
based on an interplay between the dynamical symmetry breaking of particle
physics and a gravity theory, conformal gravity, which possesses an underlying
local conformal invariant structure. Central to the discussion is the
recognition that when symmetry is broken dynamically in a conformal invariant
theory, the cosmological constant is both induced by and constrained by
zero-point fluctuations. We describe what still needs to be done.


title: Compactification for essentially finite-type maps

abstract:
  We show that any separated essentially finite-type map $f$ of noetherian
schemes globally factors as $f = hi$ where $i$ is an injective localization map
and $h$ a separated finite-type map. In particular, via Nagata's
compactification theorem, $h$ can be chosen to be proper. We apply these
results to Grothendieck duality. We also obtain other factorization results and
provide essentialized versions of many general results such as Zariski's Main
Theorem, Chow's Lemma, and blow-up descriptions of birational maps.


title: Type III Seesaw and Left-Right Symmetry

abstract:
  The implementation of the Type III seesaw mechanism for neutrino masses in
the context of left-right theories where parity is broken spontaneously is
investigated. We propose a simple left-right symmetric theory where the
neutrinos masses are generated through a double seesaw mechanism which is a
combination of Type I and Type III seesaw. In this context we find a possible
candidate for the cold dark matter in the Universe and discuss the Baryogenesis
via Leptogenesis mechanisms. The spectrum of the theory, the phenomenological
constraints and the possibility to test the theory at the Large Hadron Collider
are investigated.


title:
Proving a manifold to be hyperbolic once it has been approximated to be
  so

abstract:
  The computer program SnapPea can approximate whether or not a three manifold
whose boundary consists of tori has a complete hyperbolic structure, but it can
not prove conclusively that this is so. This article provides a method for
proving that such a manifold has a complete hyperbolic structure based on the
approximations of SNAP, a program that includes the functionality of SnapPea
plus other features. The approximation is done by triangulating the manifold,
identifying consistency and completeness equations with respect to this
triangulation, and then trying to solve the system of equations using Newton's
Method. This produces an approximate, not actual solution. The method developed
here uses Kantorovich's theorem to prove that an actual solution exists,
thereby assuring that the manifold has a complete hyperbolic structure. Using
this, we can definitively prove that every manifold in the SnapPea cusped
census has a complete hyperbolic structure.


title: Linear algebra meets Lie algebra: the Kostant-Wallach theory

abstract:
  In two languages, Linear Algebra and Lie Algebra, we describe the results of
Kostant and Wallach on the fibre of matrices with prescribed eigenvalues of all
leading principal submatrices. In addition, we present a brief introduction to
basic notions in Algebraic Geometry, Integrable Systems, and Lie Algebra aimed
at specialists in Linear Algebra.


title: On Information-Theoretic Scaling Laws for Wireless Networks

abstract:
  With the analysis of the hierarchical scheme, the potential influence of the
pre-constant in deriving scaling laws is exposed. It is found that a modified
hierarchical scheme can achieve a throughput arbitrarily times higher than the
original one, although it is still diminishingly small compared to the linear
scaling. The study demonstrates the essential importance of the throughput
formula itself, rather than the scaling laws consequently derived.


title: Inflationary Axion Cosmology Beyond Our Horizon

abstract:
  In theories of axion dark matter with large axion decay constant, temperature
variations in the CMB are extremely sensitive to perturbations in the initial
axion field, allowing one to place a lower bound on the total amount of
inflation. The most stringent bound comes from axion strings, which for axion
decay constant f=10^17 GeV would currently be observable at a distance of 6 x
10^16 light-years, nearly ten million times as far away as our horizon.


title: Schatten-von Neumann properties in the Weyl calculus

abstract:
  Let $\Op_t(a)$, for $t\in \mathbf R$, be the pseudo-differential operator $$
f(x) \mapsto (2\pi)^{-n}\iint a((1-t)x+ty,\xi)f(y)e^{i\scal {x-y}\xi} dyd\xi $$
and let $\mathscr I_p$ be the set of Schatten-von Neumann operators of order
$p\in [1,\infty ]$ on $L^2$. We are especially concerned with the Weyl case
(i.{}e. when $t=1/2$). We prove that if $m$ and $g$ are appropriate metrics and
weight functions respectively, $h_g$ is the Planck's function, $h_g^{k/2}m\in
L^p$ for some $k\ge 0$ and $a\in S(m,g)$, then $\Op_t(a)\in \mathscr I_p$, iff
$a\in L^p$. Consequently, if $0\le \delta <\rho \le 1$ and $a\in S^r_{\rho
,\delta}$, then $\Op_t(a)$ is bounded on $L^2$, iff $a\in L^\infty$.


title: Bounds on the Capacity of the Relay Channel with States at the Source

abstract: This paper has been withdrawn by the authors


title: The Night before the LHC

abstract:
  I review recent developments on the use of mT2 variables for SUSY parameter
study, which might be useful for the data analysis in the early stage of the
LHC experiments. I also review some of recent interesting studies. Talk in
SUSY08.


title: Magnetic dilaton strings in anti-de Sitter spaces

abstract:
  With an appropriate combination of three Liouville-type dilaton potentials,
we construct a new class of spinning magnetic dilaton string solutions which
produces a longitudinal magnetic field in the background of anti-de Sitter
spacetime. These solutions have no curvature singularity and no horizon, but
have a conic geometry. We find that the spinning string has a net electric
charge which is proportional to the rotation parameter. We present the suitable
counterterm which removes the divergences of the action in the presence of
dilaton potential. We also calculate the conserved quantities of the solutions
by using the counterterm method.


title:
Manipulation of Dark States and Control of Coherent Processes with
  Spectrally Broad Light

abstract:
  The formation of dark states under interaction of degenerate atomic states
with incoherent broadband radiation (white light) is discussed. A simple
coupling scheme in a three level Lambda-system, which allows both qualitative
and quantitative analysis is discussed. We found a stationary solution of the
optical Bloch equations in a broad excitation line approximation that describes
the dynamics of the atom-white light interaction and demonstrated its identity
to a conventional dark state created with coherent laser fields. We than
examine the efficiency of the population transfer induced by broadband
radiation in a model Lambda-system and revealed that high efficiency (attaining
100 percent) of stimulated Raman adiabatic passage-like processes can be
achieved with certain temporal control of light polarization. The corresponding
criterion of adiabaticity was formulated and justified by means of numerical
simulations.


title:
Energy Spectrum of the Electrons Accelerated by a Reconnection Electric
  Field: Exponential or Power Law?

abstract:
  The direct current (DC) electric field near the reconnection region has been
proposed as an effective mechanism to accelerate protons and electrons in solar
flares. A power-law energy spectrum was generally claimed in the simulations of
electron acceleration by the reconnection electric field. However in most of
the literature, the electric and magnetic fields were chosen independently. In
this paper, we perform test-particle simulations of electron acceleration in a
reconnecting magnetic field, where both the electric and magnetic fields are
adopted from numerical simulations of the MHD equations. It is found that the
accelerated electrons present a truncated power-law energy spectrum with an
exponential tail at high energies, which is analogous to the case of diffusive
shock acceleration. The influences of reconnection parameters on the spectral
feature are also investigated, such as the longitudinal and transverse
components of the magnetic field and the size of the current sheet. It is
suggested that the DC electric field alone might not be able to reproduce the
observed single or double power-law distributions.


title: Neutrino effects in two-body electron-capture measurements at GSI

abstract:
  Oscillatory behavior of electron capture rates in the two-body decay of
hydrogen-like ions into recoil ions plus undetected neutrinos, with a period of
approximately 7 s, was reported in storage ring single-ion experiments at the
GSI Laboratory, Darmstadt. Ivanov and Kienle [PRL 103, 062502 (2009)] have
relegated this period to neutrino masses through neutrino mixing in the final
state. New arguments are given here against this interpretation, while
suggesting that these `GSI Oscillations' may be related to neutrino spin
precession in the static magnetic field of the storage ring. This scenario
requires a Dirac neutrino magnetic moment six times smaller than the Borexino
solar neutrino upper limit 0.54 x 10E(-10) of the Bohr magneton [PRL 101,
091302 (2008)], and its consequences are explored.


abstract:
  It is proven that K-causality coincides with stable causality, and that in a
K-causal spacetime the relation K^+ coincides with the Seifert's relation. As a
consequence the causal relation "the spacetime is strongly causal and the
closure of the causal relation is transitive" stays between stable causality
and causal continuity.


title:
Voltage-current and voltage-flux characteristics of asymmetric high TC
  DC SQUIDs

abstract:
  We report measurements of transfer functions and flux shifts of 20 on-chip
high T$_C$ DC SQUIDs half of which were made purposely geometrically
asymmetric. All of these SQUIDs were fabricated using standard high T$_C$ thin
film technology and they were single layer ones, having 140 nm thickness of
YBa$_2$Cu$_3$O$_{7-x}$ film deposited by laser ablation onto MgO bicrystal
substrates with 24$^0$ misorientation angle. For every SQUID the parameters of
its intrinsic asymmetry, i. e., the density of critical current and resistivity
of every junction, were measured directly and independently. We showed that the
main reason for the on-chip spreading of SQUIDs' voltage-current and
voltage-flux characteristics was the intrinsic asymmetry. We found that for
SQUIDs with a relative large inductance ($L>120 $ pH) both the voltage
modulation and the transfer function were not very sensitive to the junctions
asymmetry, whereas SQUIDs with smaller inductance ($L\simeq 65-75 $ pH) were
more sensitive. The results obtained in the paper are important for the
implementation in the sensitive instruments based on high T$_C$ SQUID arrays
and gratings.


title: Friedman vs Abel equations: A connection unraveled

abstract:
  We present an interesting connection between Einstein-Friedmann equations for
the models of universe filled with scalar field and the special form of Abel
equation of the first kind. This connection works in both ways: first, we show
how, knowing the general solution of the Abel equation (corresponding to the
given scalar field potential) one can obtain the general solution of the
Friedman Equation (and use the former for studying such problems as existence
of inflation with exit for particular models). On the other hand, one can
invert the procedure and construct the B\"{a}cklund auto-transformations for
the Abel equation.


title:
Extremely metal-poor star-forming galaxies. New detections and general
  morphological and photometric properties

abstract:
  (abridged) We present long-slit spectroscopy with the 3.6m ESO telescope of
eight HII regions in seven star-forming (SF) dwarf galaxies, discovered in SDSS
DR4 and 6dFGRS. In addition, we use SDSS imaging data to study the photometric
structure of the sample galaxies. From the 3.6m telescope spectra, we determine
the oxygen abundance of these systems to be 7.3<12+log(O/H)<7.6, placing them
among the most metal-poor SF galaxies ever discovered. Our photometric analysis
reveals a moderately blue, stellar host galaxy in all sample galaxies. The
detection of a stellar host in all galaxies studied here and all previously
studied extremely metal-deficient SF galaxies implies that they are unlikely to
be forming their first generation of stars. With regard to the structural
properties of their host galaxy, we demonstrate that these systems are
indistinguishable from blue compact dwarf (BCD) galaxies. However, in contrast
to the majority (>90%) of BCDs that are characterised by red elliptical host
galaxies, extremely metal-poor SF dwarfs (hereafter XBCDs) reveal moderately
blue and irregular hosts. This is consistent with a young evolutionary status
and in the framework of standard star formation histories implies that several
XBCDs formed most of their stellar mass in the past 2 Gyr. A large fraction of
XBCDs reveal a cometary morphology due to the presence of intense SF activity
at one edge of an elongated host galaxy with a gradually decreasing surface
brightness towards its antipodal end.


title:
Contact Integrable Extensions of Symmetry Pseudo-Group and Coverings of
  the r-th Modified Dispersionless Kadomtsev -- Petviashvili Equation

abstract:
  We apply the technique of integrable extensions to the symmetry pseudo-group
of the r-th mdKP equation. This gives another look on deriving known coverings
and allows us to find new coverings for this equation.


title:
Scaling behavior and sea quark dependence of pion spectrum with
  HYP-smeared staggered fermions

abstract:
  We study the pion spectrum (and in particular taste-symmetry breaking within
it) using HYP-smeared valence staggered fermions on the coarse and fine MILC
lattices (which have asqtad staggered sea quarks). We focus on the dependence
on lattice spacing and sea-quark mass. We also update our results on source
dependence. Our main conclusion is that on the MILC fine lattices the
appropriate power-counting for SU(3) staggered chiral perturbation theory may
have discretization errors entering at next-to-leading order rather than at
leading-order.


title: Calculating $B_K$ using HYP staggered fermions

abstract:
  We give an update on our calculation of $B_K$ using HYP-smeared valence
staggered quarks. We have results for $B_K$ at tree-level on several coarse
MILC lattices ($a\approx 0.12 $fm) and one of the fine lattices ($a\approx 0.09
$fm), using 10 light valence quarks ranging down to $m_s^{\rm phys}/10$. We
have generalized staggered chiral perturbation theory to our mixed action
setup, and outline the results. We explain our present fitting strategy, and
give some preliminary results.


title: On the radial geodesics of Kerr's manifold

abstract:
  The so-called stationary-limit surface of Kerr's manifold represents an
nsuperable barrier for the arriving material elements and light-rays.


title:
Quark deconfinement phase transition for improved quark mass
  density-dependent model

abstract:
  By using the finite temperature quantum field theory, we calculate the finite
temperature effective potential and extend the improved quark mass
density-dependent model to finite temperature. It is shown that this model can
not only describe the saturation properties of nuclear matter, but also explain
the quark deconfinement phase transition successfully. The critical temperature
is given and the effect of $\omega$- meson is addressed.


title: Triminimal Parametrization of Quark Mixing Matrix

abstract:
  Starting from a new zeroth order basis for quark mixing (CKM) matrix based on
the quark-lepton complementarity and the tri-bimaximal pattern of lepton
mixing, we derive a triminimal parametrization of CKM matrix with three small
angles and a CP-violating phase as its parameters. This new triminimal
parametrization has the merits of fast convergence and simplicity in
application. With the quark-lepton complementary relations, we derive relations
between the two unified triminimal parametrizations for quark mixing obtained
in this work and for lepton mixing obtained by Pakvasa-Rodejohann-Weiler.
Parametrization deviating from quark-lepton complementarity is also discussed.


title: Study of X(3872) in $B$ meson decays

abstract:
  We present results on the X(3872), produced in $B^+ \to X(3872) K^+$ and $B^0
\to X(3872) K^0_S$ decays where $X(3872) \to J/\psi \pi^+ \pi^-$. We report the
first statistically significant observation of $B^0 \to X(3872) K^0_S$ and
measure the ratio of branching fractions to be $\frac{{\cal B}(B^0 \to
X(3872)K^0)} {{\cal B}(B^+ \to X(3872)K^+)} = 0.82 \pm 0.22 \pm 0.05$,
consistent with unity. The mass difference between the X(3872) states produced
in $B^+$ and $B^0$ decay is found to be $\delta M \equiv M_{XK^+} - M_{XK^0} =
(+0.18 \pm 0.89 \pm 0.26)$ MeV/$c^2$, consistent with zero. In addition, we
search for the X(3872) in the decay $B^0 \to X(3872)K^+\pi^-$, $X(3872) \to
J/\psi \pi^+ \pi^-$. We measure ${\cal B}(B^0 \to X(3872) (K^+ \pi^-)_{NR})
\times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) = (8.1 \pm 2.0
^{+1.1}_{-1.4})\times 10^{-6}$ and we set the 90% C.L. limit, ${\cal B}(B^0 \to
X(3872)K^{*}(892)^0) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) < 3.4
\times 10^{-6}$. The analysis is based on a 605 fb$^{-1}$ data sample collected
at the $\Upsilon(4S)$ with the Belle detector at the KEKB collider.


title: Anomaly-free representations of the holonomy-flux algebra

abstract:
  We work on the uniqueness, gr-qc/0504147, of representations of the
holonomy-flux algebra in loop quantum gravity. We argue that for analytic
diffeomorphisms, the flux operators can be only constants as functions on the
configuration space in representations with no anomaly, which are zero in the
standard representation.


title:
Applications of Universal Source Coding to Statistical Analysis of Time
  Series

abstract:
  We show how universal codes can be used for solving some of the most
important statistical problems for time series. By definition, a universal code
(or a universal lossless data compressor) can compress any sequence generated
by a stationary and ergodic source asymptotically to the Shannon entropy,
which, in turn, is the best achievable ratio for lossless data compressors.
  We consider finite-alphabet and real-valued time series and the following
problems: estimation of the limiting probabilities for finite-alphabet time
series and estimation of the density for real-valued time series, the on-line
prediction, regression, classification (or problems with side information) for
both types of the time series and the following problems of hypothesis testing:
goodness-of-fit testing, or identity testing, and testing of serial
independence. It is important to note that all problems are considered in the
framework of classical mathematical statistics and, on the other hand, everyday
methods of data compression (or archivers) can be used as a tool for the
estimation and testing. It turns out, that quite often the suggested methods
and tests are more powerful than known ones when they are applied in practice.


title: Large deviations for random walk in a random environment

abstract:
  In this work, we study the large deviation properties of random walk in a
random environment on $\mathbb{Z}^d$ with $d\geq1$.
  We start with the quenched case, take the point of view of the particle, and
prove the large deviation principle (LDP) for the pair empirical measure of the
environment Markov chain. By an appropriate contraction, we deduce the quenched
LDP for the mean velocity of the particle and obtain a variational formula for
the corresponding rate function $I_q$. We propose an Ansatz for the minimizer
of this formula. This Ansatz is easily verified when $d=1$.
  In his 2003 paper, Varadhan proves the averaged LDP for the mean velocity and
gives a variational formula for the corresponding rate function $I_a$. Under
the non-nestling assumption (resp. Kalikow's condition), we show that $I_a$ is
strictly convex and analytic on a non-empty open set $\mathcal{A}$, and that
the true velocity $\xi_o$ is an element (resp. in the closure) of
$\mathcal{A}$. We then identify the minimizer of Varadhan's variational formula
at any $\xi\in\mathcal{A}$.
  For walks in high dimension, we believe that $I_a$ and $I_q$ agree on a set
with non-empty interior. We prove this for space-time walks when the dimension
is at least 3+1. In the latter case, we show that the cheapest way to condition
the asymptotic mean velocity of the particle to be equal to any $\xi$ close to
$\xi_o$ is to tilt the transition kernel of the environment Markov chain via a
Doob $h$-transform.


title: On the notion of Cohen-Macaulayness for non Noetherian rings

abstract:
  There exist many characterizations of Noetherian Cohen-Macaulay rings in the
literature. These characterizations do not remain equivalent if we drop the
Noetherian assumption. The aim of this paper is to provide some comparisons
between some of these characterizations in non Noetherian case. Toward solving
a conjecture posed by Glaz, we give a generalization of the Hochster-Eagon
result on Cohen-Macaulayness of invariant rings, in the context of non
Noetherian rings.


title: SU(2) chiral perturbation theory for Kl3 decay amplitudes

abstract:
  We use one-loop $\SU(2)_L\times \SU(2)_R$ chiral perturbation theory
($\SU(2)$ ChPT) to study the behaviour of the form-factors for semileptonic
$K\to\pi$ decays with the pion mass at $q^2=0$ and at
$q^2_{\textrm{max}}=(m_K-m_\pi)^2$, where $q$ is the momentum transfer. At
$q^2=0$, the final-state pion has an energy of approximately $m_K/2$ (for
$m_K\gg m_\pi$) and so is not soft, nevertheless it is possible to compute the
chiral logarithms, i.e. the corrections of $O(m_\pi^2\log(m_\pi^2))$. We
envisage that our results at $q^2=0$ will be useful in extrapolating lattice
QCD results to physical masses. A consequence of the Callan-Treiman relation is
that in the $\SU(2)$ chiral limit ($m_u=m_d=0$), the scalar form factor $f^0$
at $\qsqmax$ is equal to $f^{(K)}/f$, the ratio of the kaon and pion leptonic
decay constants in the chiral limit. Lattice results for the scalar form factor
at $\qsqmax$ are obtained with excellent precision, but at the masses at which
the simulations are performed the results are about 25% below $f^{(K)}/f$ and
are increasing only very slowly. We investigate the chiral behaviour of
$f^0(\qsqmax)$ and find large corrections which provide a semi-quantitative
explanation of the difference between the lattice results and $f^{(K)}/f$. We
stress the generality of the relation $f^0_{P\to\pi}(\qsqmax)=f^{(P)}/f$ in the
$\SU(2)$ chiral limit, where $P=K,D$ or $B$ and briefly comment on the
potential value of using this theorem in obtaining physical results from
lattice simulations.


title: AGILE detection of delayed gamma-ray emission from GRB 080514B

abstract:
  GRB 080514B is the first gamma ray burst (GRB), since the time of EGRET, for
which individual photons of energy above several tens of MeV have been detected
with a pair-conversion tracker telescope. This burst was discovered with the
Italian AGILE gamma-ray satellite. The GRB was localized with a cooperation by
AGILE and the interplanetary network (IPN). The gamma-ray imager (GRID)
estimate of the position, obtained before the SuperAGILE-IPN localization, is
found to be consistent with the burst position. The hard X-ray emission
observed by SuperAGILE lasted about 7 s, while there is evidence that the
emission above 30 MeV extends for a longer duration (at least ~13 s). Similar
behavior was seen in the past from a few other GRBs observed with EGRET.
However, the latter measurements were affected, during the brightest phases, by
instrumental dead time effects, resulting in only lower limits to the burst
intensity. Thanks to the small dead time of the AGILE/GRID we could assess that
in the case of GRB 080514B the gamma-ray to X-ray flux ratio changes
significantly between the prompt and extended emission phase.


title: Evolutionary models for simple biosystems

abstract:
  The concept of evolutionary development of structures constituted a
\emph{real} revolution in biology: it was possible to understand how the very
complex structures of life can arise in an out-of-equilibrium system. The
investigation of such systems has shown that indeed, systems under a flux of
energy or matter can self-organize into complex patterns, think for instance to
Rayleigh-Bernard convection, Liesegang rings, patterns formed by granular
systems under shear. Following this line, one could characterize life as a
state of matter, characterized by the slow, continuous process that we call
evolution. In this paper we try to identify the organizational level of life,
that spans several orders of magnitude from the elementary constituents to
whole ecosystems.
  Although similar structures can be found in other contexts like ideas (memes)
in neural systems and self-replicating elements (computer viruses, worms, etc.)
in computer systems, we shall concentrate on biological evolutionary structure,
and try to put into evidence the role and the emergence of network structure in
such systems.


title: Multicomplexes and spectral sequences

abstract:
  In this note we present some algebraic examples of multicomplexes whose
differentials differ from those in the spectral sequences associated to the
multicomplexes. The motivation for constructing examples showing the algebraic
distinction between a multicomplex and its associated spectral sequence comes
from the author's work on Morse-Bott homology with A. Banyaga.


title:
The ring of projective invariants of eight points on the line via
  representation theory

abstract:
  The ring of projective invariants of eight ordered points on the line is a
quotient of the polynomial ring on V, where V is a fourteen-dimensional
representation of S_8, by an ideal I_8, so the modular fivefold (P^1)^8 //
GL(2) is Proj(Sym* (V)/I_8). We show that there is a unique cubic hypersurface
S in PV whose equation s is skew-invariant, and that the singular locus of S is
the modular fivefold. In particular, over Z[1/3], the modular fivefold is cut
out by the 14 partial derivatives of s. Better: these equations generate I_8.
In characteristic 3, the cubic s is needed to generate the ideal. The existence
of such a cubic was predicted by Dolgachev. Over Q, we recover the 14 quadrics
found by computer calculation by Koike, and our approach yields a conceptual
representation-theoretic description of the presentation. Additionally we find
the graded Betti numbers of a minimal free resolution in any characteristic.
  The proof over Q is by pure thought, using Lie theory and commutative
algebra. Over Z, the assistance of a computer was necessary. This result will
be used as the base case describing the equations of the moduli space of an
arbitrary number of points on P^1, with arbitrary weighting, in a later paper,
completing the program of our previous paper (Duke Math. J.). The modular
fivefold, and corresponding ring, are known to have a number of special
incarnations, due to Deligne-Mostow, Kondo, and Freitag-Salvati Manni, for
example as ball quotients or ring of modular forms respectively.


title:
Interplay between Jahn-Teller instability, uniaxial magnetism and
  ferroelectricity in Ca3CoMnO6

abstract:
  Ca3CoMnO6 is composed of CoMnO6 chains made up of face-sharing CoO6 trigonal
prisms and MnO6 octahedra. The structural, magnetic, and ferroelectric
properties of this compound were investigated on the basis of density
functional theory calculations. Ca3CoMnO6 is found to undergo a Jahn-Teller
distortion associated with the CoO6 trigonal prisms containing high-spin Co2+
(d7) ions, which removes the C3 rotational symmetry and hence uniaxial
magnetism. However, the Jahn-Teller distortion is not strong enough to fully
quench the orbital moment of the high-spin Co2+ ions thereby leading to an
electronic state with substantial magnetic anisotropy. The Jahn-Teller
distorted Ca3CoMnO6 in the magnetic ground state with up-up-down-down spin
arrangement is predicted to have electric polarizations much greater than
experimentally observed. Implications of the discrepancy between theory and
experiment were discussed.


title:
Smooth dependence on parameters of solution of cohomology equations over
  Anosov systems and applications to cohomology equations on diffeomorphism
  groups

abstract:
  We consider the dependence on parameters of the solutions of cohomology
equations over Anosov diffeomorphisms. We show that the solutions depend on
parameters as smoothly as the data. As a consequence we prove optimal
regularity results for the solutions of equations taking value in
diffeomorphism groups. These results are motivated by applications to rigidity
theory, dynamical systems, and geometry. In particular, in the context of
diffeomorphism groups we show: Let $f$ be a transitive Anosov diffeomorphism of
a compact manifold $M$. Suppose that $\eta \in C^{\reg}(M,\Diff^r(N))$ for a
compact manifold $N$, $k,r \in \N$, $r \geq 1$, and $0 < \alpha \leq \Lip$. We
show that if there exists a $\varphi\in C^{\reg}(M,\Diff^1(N))$ solving
\begin{equation*} \varphi_{f(x)} = \eta_x \circ \varphi_x \end{equation*} then
in fact $\varphi \in C^{\reg}(M,\Diff^r(N))$.


title: Bounded Underapproximations

abstract:
  We show a new and constructive proof of the following language-theoretic
result: for every context-free language L, there is a bounded context-free
language L' included in L which has the same Parikh (commutative) image as L.
Bounded languages, introduced by Ginsburg and Spanier, are subsets of regular
languages of the form w1*w2*...wk* for some finite words w1,...,wk. In
particular bounded subsets of context-free languages have nice structural and
decidability properties. Our proof proceeds in two parts. First, using Newton's
iterations on the language semiring, we construct a context-free subset Ls of L
that can be represented as a sequence of substitutions on a linear language and
has the same Parikh image as L. Second, we inductively construct a
Parikh-equivalent bounded context-free subset of Ls.
  We show two applications of this result in model checking: to
underapproximate the reachable state space of multithreaded procedural programs
and to underapproximate the reachable state space of recursive counter
programs. The bounded language constructed above provides a decidable
underapproximation for the original problems. By iterating the construction, we
get a semi-algorithm for the original problems that constructs a sequence of
underapproximations such that no two underapproximations of the sequence can be
compared. This provides a progress guarantee: every word w in L is in some
underapproximation of the sequence. In addition, we show that our approach
subsumes context-bounded reachability for multithreaded programs.


title: Dynamics of Information Entropies in Nonextensive Systems

abstract:
  We have discussed dynamical properties of the Tsallis entropy and the
generalized Fisher information in nonextensive systems described by the
Langevin model subjected to additive and multiplicative noise. Analytical
expressions for the time-dependent Tsallis entropy and generalized Fisher
information have been obtained with the use of the $q$-moment approach to the
Fokker-Planck equation developed in a previous study [H. Hasegawa, Phys. Rev. E
{\bf 77}, 031133 (2008)]. Model calculations of the information entropies in
response to an applied pulse and sinusoidal inputs have been presented.


title: Complex Burgers' equation in 2D SU(N) YM

abstract:
  An integro-differential equation satisfied by an eigenvalue density defined
as the logarithmic derivative of the average inverse characteristic polynomial
of a Wilson loop in two dimensional pure Yang Mills theory with gauge group
SU(N) is derived from two associated complex Burgers' equations, with viscosity
given by 1/(2N). The Wilson loop does not intersect itself and Euclidean
space-time is assumed flat and infinite. This result provides an extension of
the infinite N solution of Durhuus and Olesen to finite N, but this extension
is not unique.


title: Pressure Study of Superconducting Oxypnictide LaFePO

abstract:
  Electrical resistivity and magnetic susceptibility measurements under high
pressure were performed on an iron-based superconductor LaFePO. A steep
increase in superconducting transition temperature (Tc) of LaFePO with dTc/dP >
4 K/GPa to a maximum of 8.8 K for P = 0.8 GPa was observed. These results are
similar to isocrystalline LaFeAsO1-xFx system reported previously. X-ray
diffraction measurements were also performed under high pressure up to 10 GPa,
where linear compressibility ka and kc are presented.


title:
Photophysics of charge-transfer excitons in thin films of \pi-conjugated
  polymers

abstract:
  We develop a theory of the electronic structure and photophysics of
interacting chains of \pi- conjugated polymers to understand the differences
between solutions and films. While photoexcitation generates only the
intrachain exciton in solutions, the optical exciton as well as weakly allowed
charge-transfer excitons are generated in films. We extend existing theories of
the lowest polaronpair and charge-transfer excitons to obtain descriptions of
the excited states of these interchain species, and show that a significant
fraction of ultrafast photoinduced absorptions in films originate from the
lowest charge-transfer exciton. Our proposed mechanism explains the
simultaneous observation of polaronlike induced absorption features peculiar to
films in ultrafast spectroscopy and the absence of mobile charge carriers as
deduced from other experiments. We also show that there is a 1:1 correspondence
between the essential states that describe the photophysics of single chains
and of interacting chains that constitute thin films.


title: A New Framework of Multistage Estimation

abstract:
  In this paper, we have established a unified framework of multistage
parameter estimation. We demonstrate that a wide variety of statistical
problems such as fixed-sample-size interval estimation, point estimation with
error control, bounded-width confidence intervals, interval estimation
following hypothesis testing, construction of confidence sequences, can be cast
into the general framework of constructing sequential random intervals with
prescribed coverage probabilities. We have developed exact methods for the
construction of such sequential random intervals in the context of multistage
sampling. In particular, we have established inclusion principle and coverage
tuning techniques to control and adjust the coverage probabilities of
sequential random intervals. We have obtained concrete sampling schemes which
are unprecedentedly efficient in terms of sampling effort as compared to
existing procedures.


title: The de Rham comparison theorem for Deligne-Mumford stacks

abstract:
  The de Rham comparison theorem for varieties, first proved by Faltings, gives
the de Rham cohomology of a variety in terms of its p-adic etale cohomology. We
extend this theorem to proper, smooth Deligne-Mumford stacks. Two approaches
are given, which both in the end reduce the problem to the already known
comparison theorem for varieties. The first approach employs the formalism of
Weil cohomologies. Unfortunately, this does not result in a complete proof of
the comparison theorem, as the author was unable to prove the required
compatibility between intersections and cup products. Nevertheless, the author
thought the results that are obtained and the method that is suggested
interesting enough to include them. The second approach uses simplicial methods
and is based on versions of the comparison theorem by Kisin and Tsuji. The
latter approach does result in a complete proof of the extended comparison
theorem.


title: About the choice of a basis in Kedlaya's algorithm

abstract:
  Kedlaya's algorithm (Kedlaya, J. Ramanujan Math. Soc 16, 2001) can be used to
count the points of arbitrary hyperelliptic curves over finite fields of
characteristic p, where p is an odd prime. The algorithm uses the cohomology of
a p-adic lift of the curve. The Frobenius morphism of the curve induces an
automorphism of this cohomological space. The key step of the algorithm is to
determine this automorphism with a sufficiently high p-adic precision: it is
given in the form of a matrix with respect to a certain basis. Edixhoven has
found a basis that has the property that the coefficients of the matrix are
p-adically integral. This allows a smaller required precision, because a
(semi-linear) power of this matrix must be computed up to some given precision.
This text describes Edixhoven's basis and provides a proof of the fact that the
basis is suitable.


title: Interaction of a Supernova Shock with the other Star in a Binary System

abstract:
  Interaction of a fast shock wave generated during a supernova explosion with
a magnetized star-companion of the supernova precursor produces a current
sheet. We consider the evolution of this current sheet and show that a
singularity (shock) is formed in finite time within the ideal MHD framework.
Charged particles (electrons) are accelerated in the vicinity of the
singularity, and their distribution function has a plateau up to the energies
of the order of $10^4 mc^2$. These fast particles radiate in the $\gamma$-range
in the strong magnetic field of the current sheet ($B\simeq 10^6 G$). Radiation
is concentrated within a narrow angle around the current sheet, $\Delta\theta
\simeq 3\cdot 10^{-4}$, and its spectrum has the maximum at several hundreds of
$keV$. Presented calculations confirm the model of cosmological GRBs proposed
by Istomin & Komberg (2002).


title: Massive stars in their death-throes

abstract:
  The study of the stars that explode as supernovae used to be a forensic
study, working backwards from the remnants of the star. This changed in 1987
when the first progenitor star was identified in pre-explosion images.
Currently there are 8 detected progenitors with another 21 non-detections, for
which only a limit on the pre-explosion luminosity can be placed. This new
avenue of supernova research has led to many interesting conclusions, most
importantly that the progenitors of the most common supernovae, type IIP, are
red supergiants as theory has long predicted. However no progenitors have been
detected thus far for the hydrogen-free type Ib/c supernovae which, given the
expected progenitors, is an unlikely result. Also observations have begun to
show evidence that luminous blue variables, which are among the most massive
stars, may directly explode as supernovae. These results contradict current
stellar evolution theory. This suggests that we may need to update our
understanding.


title: Nonlocal interactions in coagulating particle systems

abstract:
  We consider a three dimensional system consisting of a large number of small
spherical particles, which move due to gravity or with laminar shear and which
merge when they cross. A size ratio criterion may be applied to restrict
merging to similar sized particles (locality of interactions) or particles
dissimilar in size (nonlocality). We perform direct numerical simulations (DNS)
of this particle system and study the resulting mass spectra. In mean field
approximation, these systems can be described by the Smoluchowski coagulation
equation (SCE). DNS of the particle system with locality enforced show the
scaling solutions or Kolmogorov-Zakharov spectra for the SCE, signifying a
constant mass flux. DNS without a size ratio criterion show -4/3 scaling for
large particles in a system with gravity, signifying a constant flux in number
of particles, which we also find analytically by assuming nonlocality of
interactions in the SCE. For laminar shear, this nonlocality is only marginal,
and our DNS show that a correction to the scaling solution is required.


title: Obstructing Sliceness in a Family of Montesinos Knots

abstract:
  Using Gauge theoretical techniques employed by Lisca for 2-bridge knots and
by Greene-Jabuka for 3-stranded pretzel knots, we show that no member of the
family of Montesinos knots M(0;[m_1+1,n_1+2],[m_2+1,n_2+2],q), with certain
restrictions on m_i, n_i, and q, can be (smoothly) slice. Our techniques use
Donaldson's diagonalization theorem and the fact that the 2-fold covers of
Montisinos knots bound plumbing 4-manifolds, many of which are negative
definite. Some of our examples include knots with signature 0 and square
determinant.


title: New structural and magnetic aspects of the nanotube system Na2V3O7

abstract:
  We present new experimental results of low temperature x-ray synchrotron
diffraction, neutron scattering and very low temperature (mK-range) bulk
measurements on the nanotube system ${\tube}$. The crystal structure determined
from our data is similar to the previously proposed model (P. Millet {\it et
al.} J. Solid State Chem. $\bf{147}$, 676 (1999)), but also deviates from it in
significant details. The structure comprises nanotubes along the c-axis formed
by stacking units of two V-rings buckled in the $ab$-plane. The space group is
P$\bar{3}$ and the composition is nonstoichiometric, Na(2-x)V3O7, x=0.17. The
thermal evolution of the lattice parameters reveals anisotropic lattice
compression on cooling. Neutron scattering experiments monitor a very weak
magnetic signal at energies from -20 to 9 meV. New magnetic susceptibility,
specific heat measurements and decay of remanent magnetization in the 30 mK -
300 mK range reveal that the previously observed transition at ~76 mK is
spin-glass like with no long-range order. Presented experimental observations
do not support models of isolated clusters, but are compatible with a model of
odd-legged S=1/2 spin tubes possibly segmented into fragments with different
lengths.


title:
A finite time result for vanishing viscosity in the plane with
  nondecaying vorticity

abstract:
  Assuming that initial velocity has finite energy and initial vorticity is
bounded in the plane, we show that for any finite time interval the unique
solutions of the Navier-Stokes equations converge uniformly to the unique
solution of the Euler equations as viscosity approaches zero. We also establish
a rate of convergence.


title:
Relativistic gravitational deflection of light and its impact on the
  modeling accuracy for the Space Interferometry Mission

abstract:
  We study the impact of relativistic gravitational deflection of light on the
accuracy of future Space Interferometry Mission (SIM). We estimate the
deflection angles caused by the monopole, quadrupole and octupole components of
gravitational fields for a number of celestial bodies in the solar system. We
observe that, in many cases, the magnitude of the corresponding effects is
significantly larger than the 1 uas accuracy expected from SIM. This fact
argues for the development of a relativistic observational model for the
mission that would account for the influence of both static and time-varying
effects of gravity on light propagation. Results presented here are different
from the ones obtained elsewhere by the fact that we specifically account for
the differential nature of the future SIM astrometric measurements. We also
obtain an estimate for the accuracy of possible determination of the
Eddington's parameter \gamma via SIM global astrometric campaign; we conclude
that accuracy of ~7 x 10^{-6} is achievable via measurements of deflection of
light by solar gravity.


title: Weak Approximation for General Degree Two del Pezzo Surfaces

abstract:
  We address weak approximation for certain del Pezzo surfaces defined over the
function field of a curve. We study the rational connectivity of the smooth
locus of degree two del Pezzo surfaces with two A1 singularities in order to
prove weak approximation for degree two del Pezzo surfaces with square-free
discriminant.


title:
Maximum Entropy Rate of Markov Sources for Systems With Non-regular
  Constraints

abstract:
  Using the concept of discrete noiseless channels, it was shown by Shannon in
A Mathematical Theory of Communication that the ultimate performance of an
encoder for a constrained system is limited by the combinatorial capacity of
the system if the constraints define a regular language. In the present work,
it is shown that this is not an inherent property of regularity but holds in
general. To show this, constrained systems are described by generating
functions and random walks on trees.


title:
Direct strain and elastic energy evaluation in rolled-up semiconductor
  tubes by x-ray micro-diffraction

abstract:
  We depict the use of x-ray diffraction as a tool to directly probe the strain
status in rolled-up semiconductor tubes. By employing continuum elasticity
theory and a simple model we are able to simulate quantitatively the strain
relaxation in perfect crystalline III-V semiconductor bi- and multilayers as
well as in rolled-up layers with dislocations. The reduction in the local
elastic energy is evaluated for each case. Limitations of the technique and
theoretical model are discussed in detail.


title: Effect of pressure on the quantum spin ladder material IPA-CuCl3

abstract:
  Inelastic neutron scattering and bulk magnetic susceptibility studies of the
quantum S=1/2 spin ladder system IPA-CuCl3 are performed under hydrostatic
pressure. The pressure dependence of the spin gap $\Delta$ is determined. At
$P=1.5$ GPa it is reduced to $\Delta=0.79$ meV from $\Delta=1.17$ meV at
ambient pressure. The results allow us to predict a soft-mode quantum phase
transition in this system at P$_\mathrm{c}\sim 4$ GPa. The measurements are
complicated by a proximity of a structural phase transition that leads to a
deterioration of the sample.


title:
Decay of the free-theory vacuum of scalar field theory in de Sitter
  spacetime in the interaction picture

abstract:
  A free-theory vacuum state of an interacting field theory, e.g. quantum
gravity, is unstable at tree level in general due to spontaneous emission of
Fock-space particles in any spacetime with no global timelike Killing vectors,
such as de Sitter spacetime, in the interaction picture. As an example, the
rate of spontaneous emission of Fock-space particles is calculated in phi^4
theory in de Sitter spacetime. It is possible that this apparent spontaneous
emission does not correspond to any physical processes because the states are
not evolved by the true Hamiltonian in the interaction picture. Nevertheless,
the constant spontaneous emission of Fock-space particles in the interaction
picture clearly demonstrates that the in- and out-vacuum states are orthogonal
to each other as emphasized by Polyakov and that the in-out perturbation
theory, which presupposes some overlap between these two vacuum states, is
inadequate. Other possible implications of apparent vacuum instability of this
kind in the interaction picture are also discussed.


title: Magnetic properties of Co-doped TiO2 anatase nanopowders

abstract:
  This letter reports on the magnetic properties of Ti1-xCoxO2 anatase phase
nanopowders with different Co contents. It is shown that oxygen vacancies play
a fundamental role in promoting the long-range ferromagnetic order in the
material studied, in addition to the transition-metal doping. Furthermore, the
results allow ruling out the premise of a strict connection between Co
clustering and the ferromagnetism observed in the Co:TiO2 anatase system.


title: The Golden Ratio Encoder

abstract:
  This paper proposes a novel Nyquist-rate analog-to-digital (A/D) conversion
algorithm which achieves exponential accuracy in the bit-rate despite using
imperfect components. The proposed algorithm is based on a robust
implementation of a beta-encoder where the value of the base beta is equal to
golden mean. It was previously shown that beta-encoders can be implemented in
such a way that their exponential accuracy is robust against threshold offsets
in the quantizer element. This paper extends this result by allowing for
imperfect analog multipliers with imprecise gain values as well. A formal
computational model for algorithmic encoders and a general test bed for
evaluating their robustness is also proposed.


title: Network Protection Codes Against Link Failures Using Network Coding

abstract:
  Protecting against link failures in communication networks is essential to
increase robustness, accessibility, and reliability of data transmission.
Recently, network coding has been proposed as a solution to provide agile and
cost efficient network protection against link failures, which does not require
data rerouting, or packet retransmission. To achieve this, separate paths have
to be provisioned to carry encoded packets, hence requiring either the addition
of extra links, or reserving some of the resources for this purpose. In this
paper, we propose network protection codes against a single link failure using
network coding, where a separate path using reserved links is not needed. In
this case portions of the link capacities are used to carry the encoded
packets.
  The scheme is extended to protect against multiple link failures and can be
implemented at an overlay layer. Although this leads to reducing the network
capacity, the network capacity reduction is asymptotically small in most cases
of practical interest. We demonstrate that such network protection codes are
equivalent to error correcting codes for erasure channels. Finally, we study
the encoding and decoding operations of such codes over the binary field.


title:
Robustness of Heisenberg-limited interferometry with balanced Fock
  states

abstract:
  Interferometry with Heisenberg limited phase resolution may play an important
role in the next generation of atomic clocks, gravitational wave detectors, and
in quantum information science. For experimental implementations the robustness
of the phase resolution is crucial since any experimental realization will be
subject to imperfections. In this article we study the robustness of phase
reconstruction with two number states as input subject to fluctuations in the
state preparation. We find that the phase resolution is insensitive to
fluctuations in the total number of particles and robust against noise in the
number difference at the input. The phase resolution depends on the uncertainty
in the number difference in a universal way that has a clear physical
interpretation: Fundamental noise due to the Heisenberg limit and noise due to
state preparation imperfection contribute essentially independently to the
total uncertainty in the phase. For number difference uncertainties less than
one the first noise source is dominant and the phase resolution is essentially
Heisenberg limited. For number difference uncertainties greater than one the
noise due to state preparation imperfection is dominant and the phase
resolution deteriorates linearly with the number difference uncertainty.


title:
Necessary and Sufficient Conditions for Success of the Nuclear Norm
  Heuristic for Rank Minimization

abstract:
  Minimizing the rank of a matrix subject to constraints is a challenging
problem that arises in many applications in control theory, machine learning,
and discrete geometry. This class of optimization problems, known as rank
minimization, is NP-HARD, and for most practical problems there are no
efficient algorithms that yield exact solutions. A popular heuristic algorithm
replaces the rank function with the nuclear norm--equal to the sum of the
singular values--of the decision variable. In this paper, we provide a
necessary and sufficient condition that quantifies when this heuristic
successfully finds the minimum rank solution of a linear constraint set. We
additionally provide a probability distribution over instances of the affine
rank minimization problem such that instances sampled from this distribution
satisfy our conditions for success with overwhelming probability provided the
number of constraints is appropriately large. Finally, we give empirical
evidence that these probabilistic bounds provide accurate predictions of the
heuristic's performance in non-asymptotic scenarios.


title:
Constructing geometrically infinite groups on boundaries of deformation
  spaces

abstract:
  Consider a geometrically finite Kleinian group $G$ without parabolic or
elliptic elements, with its Kleinian manifold $M=(\H^3\cup \Omega_G)/G$.
Suppose that for each boundary component of $M$, either a maximal and connected
measured lamination in the Masur domain or a marked conformal structure is
given. In this setting, we shall prove that there is an algebraic limit
$\Gamma$ of quasi-conformal deformations of $G$ such that there is a
homeomorphism $h$ from $\mathrm{Int} M$ to $\H^3/\Gamma$ compatible with the
natural isomorphism from $G$ to $\Gamma$, the given laminations are
unrealisable in $\H^3/\Gamma$, and the given conformal structures are pushed
forward by $h$ to those of $\H^3/\Gamma$. Based on this theorem and its proof,
in the subsequent paper, the Bers-Thurston conjecture, saying that every
finitely generated Kleinian group is an algebraic limit of quasi-conformal
deformations of minimally parabolic geometrically finite group, is proved using
recent solutions of Marden's conjecture by Agol, Calegari-Gabai, and the ending
lamination conjecture by Minsky collaborating with Brock, Canary and Masur.


title:
Combinatorics and topology of straightening maps I: compactness and
  bijectivity

abstract:
  We study the parameter space structure of degree $d \ge 3$ one complex
variable polynomials as dynamical systems acting on $\C$. We introduce and
study {\it straightening maps}. These maps are a natural higher degree
generalization of the ones introduced by Douady and Hubbard to prove the
existence of small copies of the Mandelbrot set inside itself. We establish
that straightening maps are always injective and that their image contains all
the corresponding hyperbolic systems. Also, we characterize straightening maps
with compact domain. Moreover, we give two classes of bijective straightening
maps. The first produces an infinite collection of embedded copies of the
$(d-1)$-fold product of the Mandelbrot set in the connectedness locus of degree
$d \ge 3$. The second produces an infinite collection of full families of
quadratic connected filled Julia sets in the cubic connectedness locus, such
that each filled Julia set is quasiconformally embedded.


title:
Jahn-Teller Inactivity and Magnetic Frustration in GeCo$_2$O$_4$ Probed
  by Ultrasound Velocity Measurements

abstract:
  Ultrasound velocity measurements of cubic spinel GeCo$_2$O$_4$ in single
crystal were performed for the investigation of shear and compression moduli.
The shear moduli in the paramagnetic state reveal an absence of Jahn-Teller
activity despite the presence of orbital degeneracy in the Co$^{2+}$ ions. Such
a Jahn-Teller inactivity indicates that the intersite orbital-orbital
interaction is much stronger than the Jahn-Teller coupling. The compression
moduli in the paramagnetic state near the N$\acute{e}$el temperature $T_N$
reveal that the most relevant exchange path for the antiferromagnetic
transition lies in the [111] direction. This exchange-path anisotropy is
consistent with the antiferromagnetic structure with the wave vector $q
\parallel$ [111], suggesting the presence of bond frustration due to
competition among a direct ferromagnetic and several distant-neighbors
antiferromagnetic interactions. In the JT-inactive condition, the bond
frustration can be induced by geometrical orbital frustration of
$t_{2g}$-$t_{2g}$ interaction between the Co$^{2+}$ ions which can be realized
in the pyrochlore lattice of the high spin Co$^{2+}$ with $t_{2g}$-orbital
degeneracy. In GeCo$_2$O$_4$, the tetragonal elongation below $T_N$ releases
the orbital frustration by quenching the orbital degeneracy.


title: Tight Bounds on Minimum Maximum Pointwise Redundancy

abstract:
  This paper presents new lower and upper bounds for the optimal compression of
binary prefix codes in terms of the most probable input symbol, where
compression efficiency is determined by the nonlinear codeword length objective
of minimizing maximum pointwise redundancy. This objective relates to both
universal modeling and Shannon coding, and these bounds are tight throughout
the interval. The upper bounds also apply to a related objective, that of dth
exponential redundancy.


title:
On a discrete optimal velocity model and its continuous and
  ultradiscrete relatives

abstract:
  We propose a discrete traffic flow model with discrete time. Continuum limit
of this model is equivalent to the optimal velocity model. It has also an
ultradiscrete limit and a piecewise-linear type of traffic flow model is
obtained. Both models show phase transition from free flow to jam in a
fundamental diagram. Moreover, the ultradiscrete model includes the
Fukui-Ishibashi model in a special case.


title: Appell Polynomials and Their Zero Attractors

abstract:
  A polynomial family $\{p_n(x)\}$ is Appell if it is given by
$\frac{e^{xt}}{g(t)} = \sum_{n=0}^\infty p_n(x)t^n$ or, equivalently, $p_n'(x)
= p_{n-1}(x)$. If $g(t)$ is an entire function, $g(0)\neq 0$, with at least one
zero, the asymptotics of linearly scaled polynomials $\{p_n(nx)\}$ are
described by means of finitely zeros of $g$, including those of minimal
modulus. As a consequence, we determine the limiting behavior of their zeros as
well as their density. The techniques and results extend our earlier work on
Euler polynomials.


title:
Spatially extended absorption around the z=2.63 radio galaxy MRC
  2025-218: outflow or infall?

abstract:
  We present an investigation into the absorber in front of the z=2.63 radio
galaxy MRC 2025-218, using integral field spectroscopy obtained at the Very
Large Telescope, and long slit spectroscopy obtained at the Keck II telescope.
The properties of MRC 2025-218 are particularly conducive to study the nature
of the absorbing gas, i.e., this galaxy shows bright and spatially extended
Ly-alpha emission, along with bright continuum emission from the active
nucleus. Ly-alpha absorption is detected across ~40x30 kpc^2, has a covering
factor of ~1, and shows remarkably little variation in its properties across
its entire spatial extent. This absorber is kinematically detached from the
extended emission line region (EELR). Its properties suggest that the absorber
is outside of the EELR. We derive lower limits to the HI, HII and H column
densities for this absorber of 3x10^16, 7x10^17 and 2x10^18 cm^-2,
respectively. Moreover, the relatively bright emission from the active nucleus
has allowed us to measure a number of metal absorption lines: CI, CII, CIV, NV,
OI, SiII, SiIV, AlII and AlIII. The column density ratios are most naturally
explained using photoionization by a hard continuum, with an ionization
parameter U~0.0005-0.005. Shocks or photoionization by young stars cannot
reproduce satisfactorily the measured column ratios. Using the ratio between
the SiII* and SiII column densities, we derive a lower limit of >10 cm^-3 for
the electron density of the absorber. The data do not allow useful constraints
to be placed on the metallicity of the absorber. We consider two possibilities
for the nature of this absorber: the cosmological infall of gas, and an outflow
driven by supernovae or the radio-jets.


title:
Chandra and XMM-Newton observations of the low-luminosity X-ray
  pulsators SAX J1324.4-6200 and SAX J1452.8-5949

abstract:
  We present results from our Chandra and XMM-Newton observations of two
low-luminosity X-ray pulsators SAX J1324.4-6200 and SAX J1452.8-5949 which have
spin-periods of 172 s and 437 s respectively. The XMM-Newton spectra for both
sources can be fitted well with a simple power-law model of photon index ~ 1.0.
A black-body model can equally well fit the spectra with a temperature of ~ 2
keV for both sources. During our XMM-Newton observations, SAX J1324.4-6200 is
detected with coherent X-ray pulsations at a period of $172.86 \pm 0.02$ s
while no pulsations with a pulse fraction greater than 15% (at 98% confidence
level) are detected in SAX J1452.8--5949. The spin period of SAX J1324.4-6200
is found to be increasing on a time-scale of $\dot{P}$ = $(6.34 \pm 0.08)
\times 10^{-9}$ s s$^{-1}$ which would suggest that the accretor is a neutron
star and not a white dwarf. Using sub-arcsec spatial resolution of the Chandra
telescope, possible counterparts are seen for both sources in the near-infrared
images obtained with the SOFI instrument on the New Technology Telescope. The
X-ray and near-infrared properties of SAX J1324.4-6200 suggest it to be either
a persistent high mass accreting X-ray pulsar or a symbiotic X-ray binary
pulsar at a distance $\le$ 9 kpc. We identify the infrared counterpart of SAX
J1452.8--5949 to be a late-type main sequence star at a distance $\le$ 10 kpc,
thus ruling out SAX J1452.8--5949 to be a high mass X-ray binary. However with
the present X-ray and near-infrared observations, we cannot make any further
conclusive conclusion about the nature of SAX J1452.8-5949.


title: Star cluster kinematics with AAOmega

abstract:
  The high-resolution setup of the AAOmega spectrograph on the Anglo-Australian
Telescope makes it a beautiful radial velocity machine, with which one can
measure velocities of up to 350-360 stars per exposure to +/-1--2 km/s in a
2-degree field of view. Here we present three case studies of star cluster
kinematics, each based on data obtained on three nights in February 2008. The
specific aims included: (i) cluster membership determination for NGC 2451A and
B, two nearby open clusters in the same line-of-sight; (ii) a study of possible
membership of the planetary nebula NGC 2438 in the open cluster M46; and (iii)
the radial velocity dispersion of M4 and NGC 6144, a pair of two globular
clusters near Antares. The results which came out of only three nights of AAT
time illustrate very nicely the potential of the instrument and, for example,
how quickly one can resolve decades of contradiction in less than two hours of
net observing time.


title: Predictive Hypothesis Identification

abstract:
  While statistics focusses on hypothesis testing and on estimating (properties
of) the true sampling distribution, in machine learning the performance of
learning algorithms on future data is the primary issue. In this paper we
bridge the gap with a general principle (PHI) that identifies hypotheses with
best predictive performance. This includes predictive point and interval
estimation, simple and composite hypothesis testing, (mixture) model selection,
and others as special cases. For concrete instantiations we will recover
well-known methods, variations thereof, and new ones. PHI nicely justifies,
reconciles, and blends (a reparametrization invariant variation of) MAP, ML,
MDL, and moment estimation. One particular feature of PHI is that it can
genuinely deal with nested hypotheses.


title:
The Impact of HI in Galaxies on 21-cm Intensity Fluctuations During the
  Reionisation Epoch

abstract:
  We investigate the impact of neutral hydrogen (HI) in galaxies on the
statistics of 21-cm fluctuations using analytic and semi-numerical modelling.
Following the reionisation of hydrogen the HI content of the Universe is
dominated by damped absorption systems (DLAs), with a cosmic density in HI that
is observed to be constant at a level equal to ~2% of the cosmic baryon density
from z~1 to z~5. We show that extrapolation of this constant fraction into the
reionisation epoch results in a reduction of 10-20% in the amplitude of 21-cm
fluctuations over a range of spatial scales. The assumption of a different
percentage during the reionisation era results in a proportional change in the
21-cm fluctuation amplitude. We find that consideration of HI in galaxies/DLAs
reduces the prominence of the HII region induced shoulder in the 21-cm power
spectrum (PS), and hence modifies the scale dependence of 21-cm fluctuations.
We also estimate the 21cm-galaxy cross PS, and show that the cross PS changes
sign on scales corresponding to the HII regions. From consideration of the
sensitivity for forthcoming low-frequency arrays we find that the effects of HI
in galaxies/DLAs on the statistics of 21-cm fluctuations will be significant
with respect to the precision of a PS or cross PS measurement. In addition,
since overdense regions are reionised first we demonstrate that the
cross-correlation between galaxies and 21-cm emission changes sign at the end
of the reionisation era, providing an alternative avenue to pinpoint the end of
reionisation. The sum of our analysis indicates that the HI content of the
galaxies that reionise the universe will need to be considered in detailed
modelling of the 21-cm intensity PS in order to correctly interpret
measurements from forthcoming low-frequency arrays.


title: Palatini f(R) gravity and Noether symmetry

abstract:
  We study Palatini f(R) cosmology using Noether symmetry approach for the
matter dominated universe. In order to construct a point-like Lagrangian in the
flat FRW space time, we use the dynamical equivalence between f(R) gravity and
scalar-tensor theories. The existence of Noether symmetry of the cosmological
f(R) Lagrangian helps us to find out the form of f(R) and the exact solutions
for cosmic scale factor. We show that this symmetry always exist for f(R)~R^n
and the Noether constant is a function of the Newton's gravitational constant
and the current matter content of the universe.


title: The Atiyah--Segal completion theorem in twisted K-theory

abstract:
  In this note we prove the analogue of the Atiyah-Segal completion theorem for
equivariant twisted K-theory in the setting of an arbitrary compact Lie group G
and an arbitrary twisting of the usually considered type. The theorem
generalizes a result by C. Dwyer, who has proven the theorem for finite G and
twistings of a more restricted type. While versions of the general result have
been known to experts, to our knowledge no proof appears in the current
literature. Our goal is to fill in this gap. The proof we give proceeds in two
stages. We first prove the theorem in the case of a twisting arising from a
graded central extension of G, following the Adams-Haeberly-Jackowski-May proof
of the classical Atiyah-Segal completion theorem. After establishing that the
theorem holds for this special class of twistings, we then deduce the general
theorem by a Mayer-Vietoris argument.


title:
Magnetic response of noncentrosymmetric superconductor La2C3: Effect of
  double-gap and spin-orbit interaction

abstract:
  The presence of spin-orbit (SO) interaction in a noncentrosymmetric
superconductor, La2C3 (T_c~11 K) is demonstrated by muon spin rotation (muSR)
in its normal state, where muSR spectra exhibit field-induced weak
depolarization due to van Vleck-like local susceptibility. In the mixed state,
muon spin relaxation due to inhomogeneity of internal field (sigma_v) exhibits
a field dependence that is characterized by a kink, where sigma_v (and hence
the superfluid density) is more strongly reduced at lower fields. This is
perfectly in line with the presence of a secondary energy gap previously
inferred from the temperature dependence of sigma_v, and also consistent with
the possible influence of asymmetric deformation of the Fermi surface due to
the SO interaction.


title:
How eccentric orbital solutions can hide planetary systems in 2:1
  resonant orbits

abstract:
  The Doppler technique measures the reflex radial motion of a star induced by
the presence of companions and is the most successful method to detect
exoplanets. If several planets are present, their signals will appear combined
in the radial motion of the star, leading to potential misinterpretations of
the data. Specifically, two planets in 2:1 resonant orbits can mimic the signal
of a single planet in an eccentric orbit. We quantify the implications of this
statistical degeneracy for a representative sample of the reported single
exoplanets with available datasets, finding that 1) around 35 percent of the
published eccentric one-planet solutions are statistically indistinguishable
from planetary systems in 2:1 orbital resonance, 2) another 40 percent cannot
be statistically distinguished from a circular orbital solution and 3) planets
with masses comparable to Earth could be hidden in known orbital solutions of
eccentric super-Earths and Neptune mass planets.


title: Matter Wave Radiation Leading to Matter Teleportation

abstract:
  The concept of matter wave radiation is put forward, and its equation is
established for the first time. The formalism solution shows that the
probability density is a function of displacement and time. A free particle and
a two-level system are reinvestigated considering the effect of matter wave
radiation. Three feasible experimental designs, especially a modified
Stern-Gerlach setup, are proposed to verify the existence of matter wave
radiation. Matter wave radiation effect in relativity has been formulated in
only a raw formulae, which offers another explanation of Lamb shift. A possible
mechanics of matter teleportation is predicted due to the effect of matter wave
radiation.