title: Hot accretion with outflow and thermal conduction

abstract:
  We present self-similar solutions for advection -dominated accretion flows
with thermal conduction in the presence of outflows. Possible effects of
outflows on the accretion flow are parametrized and a saturated form of thermal
conduction, as is appropriate for the weakly-collisional regime of interest, is
included in our model. While the cooling effect of outflows is noticeable,
thermal conduction provides an extra heating source. In comparison to accretion
flows without winds, we show that the disc rotates faster and becomes cooler
because of the angular momentum and energy flux which are taking away by the
winds. But thermal conduction opposes the effects of winds and not only
decreases the rotational velocity, but increases the temperature. However,
reduction of the surface density and the enhanced accretion velocity are
amplified by both of the winds and the thermal conduction. We find that for
stronger outflows, a higher level of saturated thermal conduction is needed to
significantly modify the physical profiles of the accretion flow.


title: Categorified Symplectic Geometry and the Classical String

abstract:
  A Lie 2-algebra is a "categorified" version of a Lie algebra: that is, a
category equipped with structures analogous those of a Lie algebra, for which
the usual laws hold up to isomorphism. In the classical mechanics of point
particles, the phase space is often a symplectic manifold, and the Poisson
bracket of functions on this space gives a Lie algebra of observables.
Multisymplectic geometry describes an n-dimensional field theory using a phase
space that is an "n-plectic manifold": a finite-dimensional manifold equipped
with a closed nondegenerate (n+1)-form. Here we consider the case n = 2. For
any 2-plectic manifold, we construct a Lie 2-algebra of observables. We then
explain how this Lie 2-algebra can be used to describe the dynamics of a
classical bosonic string. Just as the presence of an electromagnetic field
affects the symplectic structure for a charged point particle, the presence of
a B field affects the 2-plectic structure for the string.


title: A Public Key Block Cipher Based on Multivariate Quadratic Quasigroups

abstract:
  We have designed a new class of public key algorithms based on quasigroup
string transformations using a specific class of quasigroups called
multivariate quadratic quasigroups (MQQ). Our public key algorithm is a
bijective mapping, it does not perform message expansions and can be used both
for encryption and signatures. The public key consist of n quadratic
polynomials with n variables where n=140, 160, ... . A particular
characteristic of our public key algorithm is that it is very fast and highly
parallelizable. More concretely, it has the speed of a typical modern symmetric
block cipher - the reason for the phrase "A Public Key Block Cipher" in the
title of this paper. Namely the reference C code for the 160-bit variant of the
algorithm performs decryption in less than 11,000 cycles (on Intel Core 2 Duo
-- using only one processor core), and around 6,000 cycles using two CPU cores
and OpenMP 2.0 library. However, implemented in Xilinx Virtex-5 FPGA that is
running on 249.4 MHz it achieves decryption throughput of 399 Mbps, and
implemented on four Xilinx Virtex-5 chips that are running on 276.7 MHz it
achieves encryption throughput of 44.27 Gbps. Compared to fastest RSA
implementations on similar FPGA platforms, MQQ algorithm is more than 10,000
times faster.


title: Motivic double shuffle

abstract:
  The goal of this article is to give an elementary proof of the double shuffle
relations directly for the Goncharov and Manin motivic multiple zeta values.
The shuffle relation is straightforward, but for the stuffle we use a
modification of a method first introduced by P. Cartier for the purpose of
proving stuffle for the real multiple zeta values via integrals and blow-up
sequences.


title: Reconstruction of Quantum Mechanics with Information Operators

abstract:
  We reconstruct quantum mechanics by introducing "information operators" and
excluding the concept of wave functions. Multiple information operators
simultaneously describe a single system and continuously develop in time even
in the process of a measurement. We also introduce the concept of condensation
for a system with many degrees of freedom in a rather general meaning. In terms
of the multiplicity of description and the condensation, we explain quantum
phenomena including measurements without the collapse of the wave function.


title:
Contraction in $L^1$ and large time behavior for a system arising in
  chemical reactions and molecular motors

abstract:
  We prove a contraction in $L^1$ property for the solutions of a nonlinear
reaction--diffusion system whose special cases include intercellular transport
as well as reversible chemical reactions. Assuming the existence of stationary
solutions we show that the solutions stabilize as $t$ tends to infinity.
Moreover, in the special case of linear reaction terms, we prove the existence
and the uniqueness (up to a multiplicative constant) of the stationary
solution.


title:
Numerical approximation of a reaction-diffusion system with fast
  reversible reaction

abstract:
  We consider the finite volume approximation of a reaction-diffusion system
with fast reversible reaction. We deduce from a priori estimates that the
approximate solution converges to the weak solution of the reaction-diffusion
problem and satisfies estimates which do not depend on the chemical kinetics
factor. It follows that the solution converges to the solution of a nonlinear
diffusion problem, as the size of the volume elements and the time steps
converge to zero while the kinetic rate tends to infinity.


title:
Classifications of Cohen-Macaulay modules - The base ring associated to
  a transversal polymatroid

abstract:
  In this thesis, we focus on the study of the base rings associated to some
transversal polymatroids. A transversal polymatroid is a special kind of
discrete polymatroid. Discrete polymatroids were introduced by Herzog and Hibi
\cite{HH} in 2002.


title: Maps, sheaves, and K3 surfaces

abstract:
  The conjectural equivalence of curve counting on Calabi-Yau 3-folds via
stable maps and stable pairs is discussed. By considering Calabi-Yau 3-folds
with K3 fibrations, the correspondence naturally connects curve and sheaf
counting on K3 surfaces. New results and conjectures (with D. Maulik) about
descendent integration on K3 surfaces are announced. The recent proof of the
Yau-Zaslow conjecture is surveyed. The paper accompanies my lecture at the Clay
research conference in Cambridge, MA in May 2008.


title: The Current Understanding on the UV Upturn

abstract:
  The unexpected high bump in the UV part of the spectrum found in nearby giant
elliptical galaxies, a.k.a. the UV upturn, has been a subject of debate. A
remarkable progress has been made lately from the observational side, mainly
involving space telescopes. The GALEX UV telescope has been obtaining thousands
of giant ellipticals in the nearby universe, while HST is resolving local
galaxies into stars and star clusters. An important clue has also been found
regarding the origin of hot HB stars, and perhaps of sdB stars. That is,
extreme amounts of helium are suspected to be the origin of the extended HB and
even to the UV upturn phenomenon. A flurry of studies are pursuing the physics
behind it. All this makes me optimistic that the origin of the UV upturn will
be revealed in the next few years. I review some of the most notable progress
and remaining issues.


title: WIMP dark matter, Higgs exchange and DAMA

abstract:
  In the WIMP scenario, there is a one-to-one relation between the dark matter
(DM) relic density and spin independent direct detection rate if both the
annihilation of DM and its elastic scattering on nuclei go dominantly through
Higgs exchange. In particular, for DM masses much smaller than the Higgs boson
mass, the ratio of the relevant cross sections depends only on the DM mass.
Assuming DM mass and direct detection rate within the ranges allowed by the
recent DAMA collaboration results -taking account of the channelling effect on
energy threshold and the null results of the other direct detection
experiments- gives a definite range for the relic density. For scalar DM
models, like the Higgs portal models or the inert doublet model, the relic
density range turns out to be in agreement with WMAP. This scenario implies
that the Higgs boson has a large branching ratio to pairs of DM particles, a
prediction which might challenge its search at the LHC.


title:
Constraining the cosmological constant and the DGP gravity with the
  double pulsar PSR J0737-3039

abstract:
  We consider the double pulsar binary system as a laboratory to locally test
the orbital effects induced by an uniform cosmological constant $\Lambda$ in
the framework of the known general relativistic laws of gravity, and the DGP
braneworld model of gravity independently of the cosmological acceleration
itself for which they were introduced. We, first, construct the ratio
R=Delta\dot\omega/Delta P of the discrepancies between the phenomenologically
determined periastron rate \dot\omega and orbital period and their predicted
values from the 1PN approximation and the third Kepler law. Then, we compare
its value R = (0.3 +/- 4) \times 10^-11 s^-2, compatible with zero within the
errors, to the ratios R_Lambda and R_DGP of the effects induced on the apsidal
rate and the orbital period by Lambda and the DGP gravity; we find them neatly
incompatible with R being R_Lambda = (3.4 +/- 0.3) \times 10^-8 s^-2 and R_DGP
= (1.4 +/- 0.1) \times 10^-7 s^-2, respectively. Such a result, which for the
case of Lambda is valid also for any other Hooke-like exotic force proportional
to r, is in agreement with other negative local tests recently performed in the
Solar System with the ratios of the non-Newtonian/Einsteinian perihelion
precessions for several pairs of planets.


title: The f-invariant and index theory

abstract:
  In this paper we prove a tertiary index theorem which relates a spectral
geometric and a homotopy theoretic invariant of an almost complex manifold with
framed boundary. It is derived from the index theoretic and homotopy theoretic
versions of a complex elliptic genus and interestingly related with the
structure of the stable homotopy groups of spheres.


title:
Maximal operators on variable Lebesgue spaces with weights related to
  oscillations of Carleson curves

abstract:
  We prove sufficient conditions for the boundedness of the maximal operator on
variable Lebesgue spaces with weights
$\varphi_{t,\gamma}(\tau)=|(\tau-t)^\gamma|$, where $\gamma$ is a complex
number, over arbitrary Carleson curves. If the curve has different spirality
indices at the point $t$ and $\gamma$ is not real, then $\varphi_{t,\gamma}$ is
an oscillating weight lying beyond the class of radial oscillating weights
considered recently by V. Kokilashvili, N. Samko, and S. Samko.


title: Disorder-Induced Phase Control in Superfluid Fermi-Bose Mixtures

abstract:
  We consider a mixture of a superfluid Fermi gas of ultracold atoms and a
Bose-Einstein condensate of molecules possessing a continuous U(1) (relative
phase) symmetry. We study the effects that a spatially random
photo-associative-dissociative symmetry breaking coupling of the systems. Such
coupling allows to control the relative phase between a superfluid order
parameter of the Fermi system and the condensate wavefunction of molecules for
temperatures below the BCS critical temperature. The presented mechanism of
phase control belongs to the general class of disorder-induced order phenomena
that rely on breaking of continuous symmetry.


title: Absorption Properties and Evolution of Active Galactic Nuclei

abstract:
  Intrinsic absorption is a fundamental physical property to understand the
evolution of active galactic nuclei (AGN). Here a sample of 1290 AGN, selected
in the 2-10 keV band from different flux-limited surveys with very high optical
identification completeness is studied. The AGN are grouped into two classes,
unabsorbed (type-1) and absorbed (type-2), depending on their optical
spectroscopic classification and X-ray absorption properties, using hardness
ratios. Utilizing the optical to X-ray flux ratios, a rough correction for the
~8% redshift incompleteness still present in the sample is applied. A strong
decrease of the absorbed fraction with X-ray luminosity is found. This can be
represented by an almost linear decrease from ~80% to ~20% in the luminosity
range log L_X=42-46 and is consistent with similar derivations in the optical
and MIR bands. A significant increase of the absorbed fraction with redshift is
found, which can be described by a power law with a slope ~(1+z)^{0.62+/-0.11},
saturating at a redshift of z~2. A simple power law fit ~(1+z)^{0.48+/-0.08}
over the whole redshift is also marginally consistent with the data. The
variation of the AGN absorption with luminosity and redshift is described with
higher statistical accuracy and smaller systematic errors than previous
results. The findings have important consequences for the broader context of
AGN and galaxy co-evolution. Here it is proposed that the cosmic downsizing in
the AGN population is due to two different feeding mechanisms: a fast process
of merger driven accretion at high luminosities and high redshifts versus a
slow process of gas accretion from gravitational instabilities in galactic
disks rebuilding around pre-formed bulges and black holes.


title: On the consistency of warm inflation

abstract:
  Conditions are obtained for the existence of a warm inflationary attractor in
the system of equations describing an inflaton coupled to radiation. These
conditions restrict the temperature dependence of the dissipative terms and the
size of thermal corrections to the inflaton potential, as well as the gradient
of the inflaton potential. When these conditions are met, the evolution
approaches a slow-roll limit and only curvature fluctuations survive on
super-horizon scales. Formulae are given for the spectral indices of the
density perturbations and the tensor/scalar density perturbation amplitude
ratio in warm inflation.


title:
Complexifications of Morse functions and the directed Donaldson-Fukaya
  category

abstract:
  Let N be a closed four dimensional manifold which admits a self-indexing
Morse function f with only 3 critical values 0,2,4, and a unique maximum and
minimum. Let g be a Riemannian metric on N such that (f,g) is Morse-Smale. We
construct from (N,f,g) a certain six dimensional exact symplectic manifold M,
together with some exact Lagrangian spheres V_4, V_2^j, V_0 in M, j=1,...,k.
These spheres correspond to the critical points x_4, x_2^j, x_0 of f, where the
subscript indicates the Morse index. (In a companion paper we explain how (M,
V_4,{V_2^j},V_0) is a model for the regular fiber and vanishing spheres of the
complexification of f, viewed as a Lefschetz fibration on the disk cotangent
bundle D(T^*N).) Our main result is a computation of the Lagrangian Floer
homology groups HF(V_4,V_2^j), HF(V_2^j,V_0), HF(V_4,V_0) and the triangle
product mu_2: HF(V_4,V_2^j) \otimes HF(V_2^j,V_0) --> HF(V_4,V_0). The outcome
is that the directed Donaldson-Fukaya category of (M,V_4,{V_2^j},V_0) is
isomorphic to the flow category of (N,f,g).


title: Gain-assisted superluminal light propagation via incoherent pump field

abstract:
  We investigate the dispersion and the absorption properties of a weak probe
field in a three-level Lambda-type atomic system. We use just an incoherent
field for controlling the group velocity of light. It is shown that the slope
of dispersion changes from positive to negative just with changing the
intensity of the indirect incoherent pumping field. Gain-assisted superluminal
light propagation appears in this system. No laser field is used in the pumping
processes.


title:
Shape coexistence near the neutron number N=20: First identification of
  the E0 decay from the deformed 0^+_2 state in 30Mg

abstract:
  The 1789 keV level in 30Mg was identified as the first excited 0^+ state by
measuring its E0 transition to the ground state. The measured small value of
rho^2(E0,0^+_2 --> 0^+_1) = 5.7(14) x 10^-3 implies a very small mixing of
competing configurations with largely different intrinsic quadrupole
deformation near N=20. Axially symmetric Beyond-Mean-Field configuration mixing
calculations identify the ground state of 30Mg to be based on neutron
configurations below the N=20 shell closure, while the excited 0^+ state mainly
consists of a two neutrons excitated into the nu1 f_{7/2} orbital. Using a
two-level model, a mixing amplitude of 0.08(4) can be derived.


title: General solutions to equation $axb^*-bx^*a^*=c$ in rings with involution

abstract:
  In [Q. Xu et al., The solutions to some operator equations, Linear Algebra
Appl.(2008), doi:10.1016/j.laa.2008.05.034], Xu et al. provided the necessary
and sufficient conditions for the existence of a solution to the equation
$AXB^*-BX^*A^*=C$ in the general setting of the adjointable operators between
Hilbert $C^*$-modules. Based on the generalized inverses, they also obtained
the general expression of the solution in the solvable case. In this paper, we
generalize their work in the more general setting of ring $R$ with involution *
and reobtain results for rectangular matrices and operators between Hilbert
$C^*$-modules by embedding the "rectangles" into rings of square matrices or
rings of operators acting on the same space.


title: Nonlinear energy harvesting

abstract:
  Ambient energy harvesting has been in recent years the recurring object of a
number of research efforts aimed at providing an autonomous solution to the
powering of small-scale electronic mobile devices. Among the different
solutions, vibration energy harvesting has played a major role due to the
almost universal presence of mechanical vibrations: from ground shaking to
human movements, from ambient sound to thermal noise. Standard approaches are
mainly based on resonant linear oscillators that are acted on by ambient
vibrations. Here we propose a new method based on the exploitation of the
dynamical features of stochastic nonlinear oscillators. Such a method is shown
to outperform standard linear oscillators and to overcome some of the most
severe limitations of present approaches, like narrow bandwidth, need for
continuous frequency tuning and low efficiency. We demonstrate the superior
performances of this method by applying it to piezoelectric energy harvesting
from ambient vibration. Experimental results from a toy-model oscillator are
described in terms of nonlinear stochastic dynamics. We prove that the method
proposed here is quite general in principle and could be applied to a wide
class of nonlinear oscillators and different energy conversion principles.
There are also potentials for realizing micro/nano-scale power generators.


title: GRIPS - Gamma-Ray Burst Investigation via Polarimetry and Spectroscopy

abstract:
  The primary scientific goal of the GRIPS mission is to revolutionize our
understanding of the early universe using gamma-ray bursts. We propose a new
generation gamma-ray observatory capable of unprecedented spectroscopy over a
wide range of gamma-ray energies (200 keV--50 MeV) and of polarimetry
(200--1000 keV). Secondary goals achievable by this mission include direct
measurements of supernova interiors through gamma-rays from radioactive decays,
nuclear astrophysics with massive stars and novae, and studies of particle
acceleration near compact stars, interstellar shocks, and clusters of galaxies.


title: Simulations of the Sunyaev-Zeldovich Effect from Quasars

abstract:
  Quasar feedback has most likely a substantial but only partially understood
impact on the formation of structure in the universe. A potential direct probe
of this feedback mechanism is the Sunyaev-Zeldovich effect: energy emitted from
quasar heats the surrounding intergalactic medium and induce a distortion in
the microwave background radiation passing through the region. Here we examine
the formation of such hot quasar bubbles using a cosmological hydrodynamic
simulation which includes a self-consistent treatment of black hole growth and
associated feedback, along with radiative gas cooling and star formation. From
this simulation, we construct microwave maps of the resulting Sunyaev-Zeldovich
effect around black holes with a range of masses and redshifts. The size of the
temperature distortion scales approximately with black hole mass and accretion
rate, with a typical amplitude up to a few micro-Kelvin on angular scales
around 10 arcseconds. We discuss prospects for the direct detection of this
signal with current and future single-dish and interferometric observations,
including ALMA and CCAT. These measurements will be challenging, but will allow
us to characterize the evolution and growth of supermassive black holes and the
role of their energy feedback on galaxy formation.


title: ZZ to llvv production in pp collisions at sqrt(s) = 1.96 TeV

abstract:
  We describe a search for Z boson pair production in pp collisions at sqrt(s)=
1.96 TeV with the D0 detector at the Fermilab Tevatron Collider using a data
sample corresponding to an integrated luminosity of 2.7 fb^-1. Using the final
state decay ZZ to llvv (where l = e or mu) we measure a signal with a 2.6
standard deviations significance (2.0 expected) and measure a cross section of
sigma(pp to ZZ + X) = 2.01 +- 0.93 (stat.) +- 0.29 (sys.) pb.


title:
VOSA: Virtual Observatory SED Analyzer. An application to the Collinder
  69 open cluster

abstract:
  The physical properties of almost any kind of astronomical object can be
derived by fitting synthetic spectra or photometry extracted from theoretical
models to observational data.
  We want to develop an automatic procedure to perform this kind of fittings to
a relatively large sample of members of a stellar association and apply this
methodology to the case of Collinder 69.
  We combine the multiwavelength data of our sources and follow a work-flow to
derive the physical parameters of the sources. The key step of the work-flow is
performed by a new VO-tool, VOSA. All the steps in this process are done in a
VO environment.
  We present this new tool, and provide physical parameters such as T$_{\rm
eff}$, gravity, luminosity, etc. for $\sim$170 candidate members to Collinder
69, and an upper-limit for the age of this stellar association.
  This kind of studies of star forming regions, clusters, etc. produces a huge
amount of data, very tedious to analyse using the traditional methodology.
Thus, they are excellent examples where to apply the VO capabilities.


title: Measurements of the Top Quark mass at CDF

abstract:
  We review the most recent measurements of the top quark mass using data
collected by the CDF experiment at the Tevatron 1.96 TeV ppbar collider. The
mass measurements are performed in all main decay modes of the produced ttbar
pairs using integrated luminosities up to 2fb-1. In most channels the total
uncertainty is dominated by systematic effects, most of which are currently
being revised. The precise measurement of the top quark mass is one of the
Tevatron's main and long lasting legacies. Besides serving as a benchmark
measurement at the LHC collider, it will serve as a consistency check of the
Standard Model in case a a neutral CP even Higgs boson is found, either at the
Tevatron or at the LHC.


title:
Kovalenko's Full-Rank Limit and Overhead as Lower Bounds for
  Error-Performances of LDPC and LT Codes over Binary Erasure Channels

abstract:
  We present Kovalenko's full-rank limit as a tight lower bound for decoding
error probability of LDPC codes and LT codes over BEC. From the limit, we
derive a full-rank overhead as a lower bound for stable overheads for
successful maximum-likelihood decoding of the codes.


title: Top Quark Mass and Cross Section Results from the Tevatron

abstract:
  This note details recent measurements of the top mass and cross section that
have been performed at the Tevatron. Most of these measurements have been
performed with between 1.0 and 2.0 fb-1 of data. Basic top physics concepts are
discussed, cross section and mass analysis methods and results are presented,
and future analysis prospects are discussed with a special attention given to
Electroweak determination of the limits on the Standard Model Higgs mass.


title: Generalized Fokker-Planck equation: Derivation and exact solutions

abstract:
  We derive the generalized Fokker-Planck equation associated with the Langevin
equation (in the Ito sense) for an overdamped particle in an external potential
driven by multiplicative noise with an arbitrary distribution of the increments
of the noise generating process. We explicitly consider this equation for
various specific types of noises, including Poisson white noise and L\'{e}vy
stable noise, and show that it reproduces all Fokker-Planck equations that are
known for these noises. Exact analytical, time-dependent and stationary
solutions of the generalized Fokker-Planck equation are derived and analyzed in
detail for the cases of a linear, a quadratic, and a tailored potential.


title: Trivial extensions defined by Prufer conditions

abstract:
  This paper deals with well-known extensions of the Prufer domain concept to
arbitrary commutative rings. We investigate the transfer of these notions in
trivial ring extensions (also called idealizations) of commutative rings by
modules and then generate original families of rings with zerodivisors subject
to various Prufer conditions. The new examples give further evidence for the
validity of Bazzoni-Glaz conjecture on the weak dimension of Gaussian rings.
Moreover, trivial ring extensions allow us to widen the scope of validity of
Kaplansky-Tsang conjecture on the content ideal of Gaussian polynomials.


title: Topology Properties of Written Human Language

abstract:
  We use the extended Barabasi model without the rewired process and show that
the degree distribution for the corresponding networks is the Tsallis
distribution. We offer an analysis of the novel "The Sound and the Fury" by W.
Faulkner in English and in Russian, and show that the degree distributions of
the relevant word networks are described with the Tsallis distribution. We have
constructed degree distributions for each of the relevant word networks and
defined the value of the nonextensivity parameter with the maximum likelihood
method. For the novel text in English qB = 1.57; qK = 1.49; qJ = 1.53; qA =
1.47; qT = 1.54, and for the translation into Russian qB = 1.50; qK = 1.42; qD
= 1.46; qA = 1.40; qT = 1.47. Therefore, if the translation of the novel is
regarded as mapping, the nonextensivity parameters ordering qB > qT > qD > qK >
qA is an invariant of this mapping.


title:
Typical elements in free groups are in different doubly-twisted
  conjugacy classes

abstract:
  We give an easily checkable algebraic condition which implies that two
elements of a finitely generated free group are members of distinct
doubly-twisted conjugacy classes with respect to a pair of homomorphisms. We
further show that this criterion is satisfied with probability 1 when the
homomorphisms and elements are chosen at random.


title: Basic properties of three-leg Heisenberg tube

abstract:
  We study three-leg antiferromagnetic Heisenberg model with the periodic
boundary conditions in the rung direction. Since the rungs form regular
triangles, spin frustration is induced. We use the density-matrix
renormalization group method to investigate the ground state. We find that the
spin excitations are always gapped to remove the spin frustration as long as
the rung coupling is nonzero. We also visibly confirm spin-Peierls dimerization
order in the leg direction. Both the spin gap and the dimerization order are
basically enhanced as the rung coupling increases.


title:
A method to correct IACT data for atmospheric absorption due to the
  Saharan Air Layer

abstract:
  Using the atmosphere as a detector volume, Imaging Air Cherenkov Telescopes
(IACTs) depend highly on the properties and the condition of the air mass above
the telescope. On the Canary Island of La Palma, where the Major Atmospheric
Gamma-ray Imaging Cherenkov telescope (MAGIC) is situated, the Saharan Air
Layer (SAL) can cause strong atmospheric absorption affecting the data quality
and resulting in a reduced gamma flux. To correlate IACT data with other
measurements, e.g. long-term monitoring or Multi-Wavelength (MWL) studies, an
accurate flux determination is mandatory. Therefore, a method to correct the
data for the effect of the SAL is needed. Three different measurements of the
atmospheric absorption are performed on La Palma. From the determined
transmission, a correction factor is calculated and applied to the MAGIC data.
The different transmission measurements from optical and IACT data provide
comparable results. MAGIC data of PG 1553+113, taken during a MWL campaign in
July 2006, have been analyzed using the presented method, providing a corrected
flux measurement for the study of the spectral energy distribution of the
source.


title:
Superradiant Instability of Five-Dimensional Rotating Charged AdS Black
  Holes

abstract:
  We study the instability of small AdS black holes with two independent
rotation parameters in minimal five-dimensional gauged supergravity to massless
scalar perturbations. We analytically solve the Klein-Gordon equation for
low-frequency perturbations in two regions of the spacetime of these black
holes: namely, in the region close to the horizon and in the far-region. By
matching the solutions in an intermediate region, we calculate the frequency
spectrum of quasinormal modes. We show that in the regime of superradiance only
the modes of even orbital quantum number undergo negative damping, resulting in
exponential growth of the amplitude. That is, the black holes become unstable
to these modes. Meanwhile, the modes of odd orbital quantum number do not
undergo any damping, oscillating with frequency-shifts. This is in contrast
with the case of four-dimensional small Kerr-AdS black holes which exhibit the
instability to all modes of scalar perturbations in the regime of
superradiance.


title: Multiferroicity in the spin-1/2 quantum matter of LiCu2O2

abstract:
  Multiferroicity in LiCu2O2 single crystals is studied using resonant soft
x-ray magnetic scattering, hard x-ray diffraction, heat capacity, magnetic
susceptibility, and electrical polarization. Two magnetic transitions are found
at 24.6 K (T1) and 23.2 K (T2). Our data are consistent with a sinusoidal spin
structure at T2<T<T1 and with a helicoidal spin structure at T<T2 giving rise
to ferroelectricity. Surprisingly, above T2 the correlation lengths of the spin
structures increase as the temperature increases with dramatic changes of ~42%
along the c-axis. Our results demonstrate the interplay of the geometrical
frustration and the electronic and magnetic polarizations.


title:
Aspects of quantum integrability for pure spinor superstring in
  AdS(5)xS(5)

abstract:
  We consider the monodromy matrix for the pure spinor IIB superstring on
$AdS_5\times S^5$ at leading order at strong coupling, in particular its
variation under an infinitesimal and continuous deformation of the contour.
Such variation is equivalent to the insertion of a local operator. Demanding
the BRST-closure for such an operator rules out its existence, implying that
the monodromy matrix remains contour-independent at the first order in
perturbation theory. Furthermore we explicitly compute the field strength
corresponding to the flat connections up to leading order and directly check
that it is free from logarithmic divergences. The absence of anomaly in the
coordinate transformation of the monodromy matrix and the UV-finiteness of the
curvature tensor finally imply the integrability of the pure spinor superstring
at the first order.


title: Innocuous Implications of a Minimum Length in Quantum Gravity

abstract:
  A modification to the time-energy uncertainty relation in quantum gravity has
been interpreted as increasing the duration of fluctuations producing virtual
black holes with masses greater than the Planck mass. I point out that such
virtual black holes have an exponential factor arising from the action such
that their contribution to proton decay is suppressed, rather than enhanced,
relative to Planck-mass black holes.


title: Uniqueness of certain polynomials constant on a line

abstract:
  We study a question with connections to linear algebra, real algebraic
geometry, combinatorics, and complex analysis. Let $p(x,y)$ be a polynomial of
degree $d$ with $N$ positive coefficients and no negative coefficients, such
that $p=1$ when $x+y=1$. A sharp estimate $d \leq 2N-3$ is known. In this paper
we study the $p$ for which equality holds. We prove some new results about the
form of these "sharp" polynomials. Using these new results and using two
independent computational methods we give a complete classification of these
polynomials up to $d=17$. The question is motivated by the problem of
classification of CR maps between spheres in different dimensions.


title: Hints from Tevatron, a prelude to what?

abstract:
  We comment on the recent results from the Tevatron experiments in the W+jets
channel and consider some models as the possible underlying physical theories.
We also list some channels for further studies.


title: Memristor for Introductory Physics

abstract:
  Using basic algebra and simple calculus, the analytical solution to the
memristor model of Strukov et al published in Nature is derived. Lissajous
figures of current responding to a sinusoidal voltage are presented.


title: Mathematical Models and Biological Meaning: Taking Trees Seriously

abstract:
  We compare three basic kinds of discrete mathematical models used to portray
phylogenetic relationships among species and higher taxa: phylogenetic trees,
Hennig trees and Nelson cladograms. All three models are trees, as that term is
commonly used in mathematics; the difference between them lies in the
biological interpretation of their vertices and edges. Phylogenetic trees and
Hennig trees carry exactly the same information, and translation between these
two kinds of trees can be accomplished by a simple algorithm. On the other
hand, evolutionary concepts such as monophyly are represented as different
mathematical substructures are represented differently in the two models. For
each phylogenetic or Hennig tree, there is a Nelson cladogram carrying the same
information, but the requirement that all taxa be represented by leaves
necessarily makes the representation less efficient. Moreover, we claim that it
is necessary to give some interpretation to the edges and internal vertices of
a Nelson cladogram in order to make it useful as a biological model. One
possibility is to interpret internal vertices as sets of characters and the
edges as statements of inclusion; however, this interpretation carries little
more than incomplete phenetic information. We assert that from the standpoint
of phylogenetics, one is forced to regard each internal vertex of a Nelson
cladogram as an actual (albeit unsampled) species simply to justify the use of
synapomorphies rather than symplesiomorphies.


title: Superconductivity in Yttrium Iron Oxyarsenide System

abstract:
  Iron-based oxypnictides substituted with yttrium have been prepared via a
conventional solid state reaction. The product after first 50 hours of reaction
showed diamagnetic-like transition at around 10 K but was not superconducting,
while additional 72 hours of high temperature heat treatment was required to
yield superconducting sample which was doped with fluoride. Temperature
dependence of the susceptibility shows both screening and Meissner effect at
around 10 K, while resistance as a function of temperature displayed a drop at
around the same temperature.


title: Superconductivity and Magnetism in REFeAsO1-xFx (RE=Rare Earth Elements)

abstract:
  Fluoride-doped iron-based oxypnictides containing rare-earth gadolinium
(GdFeAsO0.8F0.2) and co-doping with yttrium (Gd0.8Y0.2FeAsO0.8F0.2) have been
prepared via conventional solid state reaction at ambient pressure. The
non-yttrium substituted oxypnictide show superconducting transition as high as
43.9 K from temperature dependent resistance measurements with the Meissner
effect observed at a lower temperature of 40.8 K from temperature dependent
magnetization measurements. By replacing a small amount of gadolinium with
yttrium Tc was observed to be lowered by 10 K which might be caused by a change
in the electronic or magnetic structures since the crystal structure was not
altered.


title: De Broglie-Bohm Guidance Equations for Arbitrary Hamiltonians

abstract:
  In a pilot-wave theory, an individual closed system is described by a
wavefunction $\psi(q)$ and configuration $q$. The evolution of the wavefunction
and configuration are respectively determined by the Schr\"odinger and guidance
equations. The guidance equation states that the velocity field for the
configuration is given by the quantum current divided by the density
$|\psi(q)|^2$. We present the currents and associated guidance equations for
any Hamiltonian given by a differential operator. These are derived directly
from the Schr\"odinger equation, and also as Noether currents arising from a
global phase symmetry associated with the wavefunction in configuration space.


title: One shot schemes for decentralized quickest change detection

abstract:
  This work considers the problem of quickest detection with N distributed
sensors that receive continuous sequential observations from the environment.
These sensors employ cumulative sum (CUSUM) strategies and communicate to a
central fusion center by one shot schemes. One shot schemes are schemes in
which the sensors communicate with the fusion center only once, after which
they must signal a detection. The communication is clearly asynchronous and the
case is considered in which the fusion center employs a minimal strategy, which
means that it declares an alarm when the first communication takes place. It is
assumed that the observations received at the sensors are independent and that
the time points at which the appearance of a signal can take place are
different. It is shown that there is no loss of performance of one shot schemes
as compared to the centralized case in an extended Lorden min-max sense, since
the minimum of N CUSUMs is asymptotically optimal as the mean time between
false alarms increases without bound.


title:
Raman scattering in current carrying molecular junctions. A preliminary
  account

abstract:
  This is a preliminary acount of a theory for Raman scattering by
current-carrying molecular junctions. The approach combines a non-equilibrium
Green's function (NEGF) description of the non-equilibrium junction with a
generalized scattering theory formulation for evaluating the light scattering
signal. This generalizes our previous study (Phys. Rev. Lett. 95, 206802
(2005); J. Chem. Phys. 124, 234709 (2006)) of junction spectroscopy by
including molecular vibrations and developing machinery for calculation of
state-to-state (Raman scattering) fluxes within the NEGF formalism. For large
enough voltage bias we find that the light scattering signal contains, in
addition to the normal signal associated with the molecular ground electronic
state, also a contribution from the inverse process originated from the excited
molecular state as well as an interference component. The effect of coupling to
the electrodes and of the imposed bias on the total Raman scattering as well as
its components are discussed. Our result reduces to the standard expression for
Raman scattering in the isolated molecule case, i.e. in the absence of coupling
to the electrodes. The theory is used to discuss the charge transfer
contribution to surface enhanced Raman scattering for molecules adsorbed on
metal surfaces and its manifestation in the biased junction.


title: A note on the non-commutative Laplace-Varadhan integral lemma

abstract:
  We continue the study of the free energy of quantum lattice spin systems
where to the local Hamiltonian $H$ an arbitrary mean field term is added, a
polynomial function of the arithmetic mean of some local observables $X$ and
$Y$ that do not necessarily commute. By slightly extending a recent paper by
Hiai, Mosonyi, Ohno and Petz [9], we prove in general that the free energy is
given by a variational principle over the range of the operators $X$ and $Y$.
As in [9], the result is a noncommutative extension of the Laplace-Varadhan
asymptotic formula.


title: The moduli of curves of genus 6 and K3 surfaces

abstract:
  We prove that the coarse moduli space of curves of genus 6 is birational to
an arithmetic quotient of a bounded symmetric domain of type IV by giving a
period map to the moduli space of some lattice-polarized K3 surfaces.


title:
Renormalization of a modified gravity with a quadratic Riemann tensor
  term

abstract:
  We consider a modified form of gravity, which has an extra term quadratic in
the Riemann tensor. This term mimics a Yang-Mills theory. The other defining
characteristic of this gravity is having the affine connection independent of
the metric. (The metricity of the metric is rejected, too, since it implies a
Levi-Civita connection.) It is then shown that, in the low density limit, this
modified gravity does not differ from the General Theory of Relativity. We then
point out that its Lagrangian does not contain partials of the metric, so that
the metric is not a quantum field, nor does it contribute propagators to the
Feynman diagrams of the theory. We also point out that the couplings of this
theory (that determine the topological structure of the Feynman diagrams) all
come from the term quadratic in the Riemann tensor. As a result of this
situation, the diagrams of this theory and the diagrams of a Yang-Mills theory
all have the same topology and degree of divergence, up to numerical
coefficients. Since Yang-Mills theories are renormalizable, it follows that
this theory should also be renormalizable.


title:
Magnetic and Transport Studies on Electron-doped CeFeAsO1-xFx
  Superconductor

abstract:
  The magnetic and transport behaviors of cerium substituted iron oxy-arsenide
superconductor with x = 0.1 to 0.4 fluoride (F) doping have been investigated
in this report. Temperature dependent susceptibility and resistivity
measurements showed the 0.1 F-doped sample (CeFeAsO0.9F0.1) has a
superconducting transition temperature (Tc) of around 30 K. With increasing
doping beyond x = 0.2 Tc saturates to around 40 K. Temperature dependent
susceptibility measured in different magnetic fields for the under-doped sample
showed Meissner effect in low field and the diamagnetism is still visible up to
1 Tesla, with an obvious magnetic transition below 5 K, perhaps originating
from magnetic ordering of the rare earth cerium. The corresponding field
dependent resistance versus temperature measurements indicated a broadening of
less than 3 K for Tc at mid-point by increasing the field to 5 Tesla indicating
rather low anisotropy. An estimated upper critical field of more than 48 Tesla
and accordingly an estimated maximum coherence length of 2.6 nm were obtained
confirming the high upper critical field with a short coherence length for this
superconductor.


title: Ellipses Inscribed in Parallelograms

abstract:
  We prove that there exists a unique ellipse of minimal eccentricity, E_{I},
inscribed in a parallelogram, D. We also prove that the smallest nonnegative
angle between equal conjugate diameters of E_{I} equals the smallest
nonnegative angle between the diagonals of D. We also prove that if E_{M} is
the unique ellipse inscribed in a rectangle, R, which is tangent at the
midpoints of the sides of R, then E_{M} is the unique ellipse of minimal
eccentricity, maximal area, and maximal arc length inscribed in R. Let D be any
convex quadrilateral. In previous papers, the author proved that there is a
unique ellipse of minimal eccentricity, E_{I}, inscribed in D, and a unique
ellipse, E_{O}, of minimal eccentricity circumscribed about D. We defined D to
be bielliptic if E_{I} and E_{O} have the same eccentricity. In this paper we
show that a parallelogram, D, is bielliptic if and only if the square of the
length of one of the diagonals of D equals twice the square of the length of
one of the sides of D.


title: Computing the nucleolus of weighted voting games

abstract:
  Weighted voting games (WVG) are coalitional games in which an agent's
contribution to a coalition is given by his it weight, and a coalition wins if
its total weight meets or exceeds a given quota. These games model
decision-making in political bodies as well as collaboration and surplus
division in multiagent domains. The computational complexity of various
solution concepts for weighted voting games received a lot of attention in
recent years. In particular, Elkind et al.(2007) studied the complexity of
stability-related solution concepts in WVGs, namely, of the core, the least
core, and the nucleolus. While they have completely characterized the
algorithmic complexity of the core and the least core, for the nucleolus they
have only provided an NP-hardness result. In this paper, we solve an open
problem posed by Elkind et al. by showing that the nucleolus of WVGs, and, more
generally, k-vector weighted voting games with fixed k, can be computed in
pseudopolynomial time, i.e., there exists an algorithm that correctly computes
the nucleolus and runs in time polynomial in the number of players and the
maximum weight. In doing so, we propose a general framework for computing the
nucleolus, which may be applicable to a wider of class of games.


title:
Direct coupling between magnetism and superconducting current in
  Josephson Phi junction

abstract:
  We study the proximity effect between conventional superconductor and
magnetic normal metal with a spin-orbit interaction of the Rashba type. Using
the phenomenological Ginzburg-Landau theory and the quasiclassical Eilenberger
approach it is demonstrated that the Josephson junction with such a metal as a
weak link has a special non-sinusoidal current-phase relation. The ground state
of this junction is caracterized by the finite phase difference Phi, which is
proportional to the strength of the spin-orbit interaction and the exchange
field in the normal metal. The proposed mechanism of the Phi junction formation
gives a direct coupling between the superconducting current and the magnetic
moment in the weak link. Therefore the Phi junctions open interesting
perspectives for the superconducting spintronics.


title:
Matrix Filters for the Detection of Extragalactic Point Sources in
  Cosmic Microwave Background Images

abstract:
  In this paper we introduce a new linear filtering technique, the so-called
matrix filters, that maximizes the signal-to-interference ratio of compact
sources of unknown intensity embedded in a set of images by taking into account
the cross-correlations between the different channels. By construction, the new
filtering technique outperforms (or at least equals) the standard matched
filter applied on individual images. An immediate application is the detection
of extragalactic point sources in Cosmic Microwave Background images obtained
at different wavelengths. We test the new technique in two simulated cases: a
simple two-channel case with ideal correlated color noise and more realistic
simulations of the sky as it will be observed by the LFI instrument of the
upcoming ESA's Planck mission. In both cases we observe an improvement with
respect to the standard matched filter in terms of signal-to-noise
interference, number of detections and number of false alarms.


title: C*-algebras associated to shift spaces

abstract:
  These are some notes I wrote for the summer school "Symbolic dynamics and
homeomorphisms of the Cantor set" at the University of Copenhagen, 23 - 27 June
2008.
  The notes contain the definition of the C*-algebra associated to a shift
space and some basic facts about these. The notes furthermore contain a proof
of the fact that the C*-algebra associated to a shift space is a one-sided
conjugacy invariant, and a proof of the fact that the Morita equivalence class
of the C*-algebra associated to a shift space is a two-sided conjugacy and a
flow invariant. The notes also contain a section (without proofs) about the
K-theory of C*-algebras associated to shift spaces.
  The notes are written for people without a background in operator algebra and
contains a short appendix about C*-algebras, Morita equivalence and K-theory of
C*-algebras.


title:
Resonant impurity scattering in the $\pm$s-gap state of the Fe-based
  superconductors

abstract:
  We study the impurity scattering on the $\pm$s-wave superconductor, with
realistic parameters for the Fe-pnictide superconductors. Using
$\mathcal{T}$-matrix method, generalized for the two bands, we found that
impurity scattering of the unitary limit forms off-centered bound states inside
of the superconducting gap, which modifies, surprisingly, the density of states
(DOS) of a fully opened gap to a V-shaped one as in the case of a d-wave
superconductor. This behavior provides coherent explanations to the several
conflicting experimental issues of the Fe-pnictide superconductors: the
V-shaped DOS but with an isotropic gap observed in the photoemission and
tunneling experiments; the power law behavior of the nuclear spin-lattice
relaxation rate ($1/T_1 \approx T^{\alpha}$ ; $\alpha \approx 3$), down to very
low temperatures.


title: Perelman's reduced volume and a gap theorem for the Ricci flow

abstract:
  In this paper, we show that any ancient solution to the Ricci flow with the
reduced volume whose asymptotic limit is sufficiently close to that of the
Gaussian soliton is isometric to the Euclidean space for all time. This is a
generalization of Anderson's result for Ricci-flat manifolds. As a corollary, a
gap theorem for gradient shrinking Ricci solitons is also obtained.


title: Glueball correlators as holograms

abstract:
  We investigate the dynamical content of both hard- and soft-wall
approximations to holographic QCD by deriving the corresponding glueball
correlation functions and by confronting them with a variety of QCD results. We
further calculate the glueball decay constants in both holographic duals,
discuss emerging limitations and improvement strategies, and comment on a
recent attempt to generalize the glueball correlator in the soft-wall
background.


title: Iron pnictides as a new setting for quantum criticality

abstract:
  Two major themes in the physics of condensed matter are quantum critical
phenomena and unconventional superconductivity. These usually occur in the
context of competing interactions in systems of strongly-correlated electrons.
All this interesting physics comes together in the behavior of the recently
discovered iron pnictide compounds that have generated enormous interest
because of their moderately high-temperature superconductivity. The ubiquity of
antiferromagnetic ordering in their phase diagrams naturally raises the
question of the relevance of magnetic quantum criticality, but the answer
remains uncertain both theoretically and experimentally. Here we show that the
undoped iron pnictides feature a novel type of magnetic quantum critical point,
which results from a competition between electronic localization and
itinerancy. Our theory provides a mechanism to understand the
experimentally-observed variation of the ordered moment among the undoped iron
pnictides. We suggest P substitution for As in the undoped iron pnictides as a
means to access this new example of magnetic quantum criticality in an unmasked
fashion. Our findings point to the iron pnictides as a much-needed new setting
for quantum criticality, one that offers a new set of control parameters.


title: Exceptional (Z/2Z) x (Z/2Z)-symmetric spaces

abstract:
  The notion of (Z/2Z) x (Z/2Z)-symmetric spaces is a generalization of
classical symmetric spaces, where the group Z/2Z is replaced by (Z/2Z) x
(Z/2Z). In this article, a classification is given of the (Z/2Z) x
(Z/2Z)-symmetric spaces G/K where G is an exceptional compact Lie group or
Spin(8), complementing recent results of Bahturin and Goze. Our results are
equivalent to a classification of (Z/2Z) x (Z/2Z)-gradings on the exceptional
simple Lie algebras e6, e7, e8, f4, g2 and so(8).


title: A high bandwidth quantum repeater

abstract:
  We present a physical- and link-level design for the creation of entangled
pairs to be used in quantum repeater applications where one can control the
noise level of the initially distributed pairs. The system can tune
dynamically, trading initial fidelity for success probability, from high
fidelity pairs (F=0.98 or above) to moderate fidelity pairs. The same physical
resources that create the long-distance entanglement are used to implement the
local gates required for entanglement purification and swapping, creating a
homogeneous repeater architecture. Optimizing the noise properties of the
initially distributed pairs significantly improves the rate of generating
long-distance Bell pairs. Finally, we discuss the performance trade-off between
spatial and temporal resources.


title: Notes on periodic elements of Garside groups

abstract:
  Let $G$ be a Garside group with Garside element $\Delta$. An element $g$ in
$G$ is said to be \emph{periodic} if some power of $g$ lies in the cyclic group
generated by $\Delta$. This paper shows the following. (i) The periodicity of
an element does not depend on the choice of a particular Garside structure if
and only if the center of $G$ is cyclic. (ii) If $g^k=\Delta^{ka}$ for some
nonzero integer $k$, then $g$ is conjugate to $\Delta^a$. (iii) Every finite
subgroup of the quotient group $G/<\Delta^m>$ is cyclic, where $\Delta^m$ is
the minimal positive central power of $\Delta$.


title: A Reliable SVD based Watermarking Schem

abstract:
  We propose a novel scheme for watermarking of digital images based on
singular value decomposition (SVD), which makes use of the fact that the SVD
subspace preserves significant amount of information of an image, as compared
to its singular value matrix, Zhang and Li (2005). The principal components of
the watermark are embedded in the original image, leaving the detector with a
complimentary set of singular vectors for watermark extraction. The above step
invariably ensures that watermark extraction from the embedded watermark image,
using a modified matrix, is not possible, thereby removing a major drawback of
an earlier proposed algorithm by Liu and Tan (2002).


title: Relativistic Flows in TeV Blazars

abstract:
  Rapid variability of the TeV emission in several blazars implies a central
black hole mass $M_{BH}<10^8M_\odot$, appreciably smaller than the values
estimated from the $M_{BH}-L_{bulg}$ relation, and Doppler factors for the
$\gamma$-ray emitting fluid much larger than those associated with radio
patterns. We discuss the conditions in the central engine required to account
for the short timescales and large luminosities observed, and propose some
explanations for the inferred kinematics of the source on various scales.


title: Gamma Ray Spectrum Unfolding Using Derivative Kernels

abstract:
  The unfolding of a gamma ray spectrum experience many difficulties due to
noise in the recorded data, that is based mainly on the change of photon energy
due to scattering mechanisms (either in the detector or the medium), the
accumulation of recorded counts in a fixed energy interval (the channel width
of the detector) and finally the statistical fluctuation inside the detector.
In order to deal with these problems, a new method is developed which
interpolates the ideal spectrum with the use of special designed derivative
kernels. Preliminary simulation results are presented and show that this
approach is very effective even in spectra with low statistics.


title:
Radius and surface tension of microscopic bubbles by second gradient
  theory

abstract:
  The classical theory of Laplace is not suitable for describing the behavior
of microscopic bubbles. The theory of second gradient fluids (which are able to
exert shear stresses in equilibrium conditions) allows us to obtain a new
expression for surface tension and radius of these bubbles in terms of
functionals of the chemical potential. This relationship allows us to
generalize the results of Cahn-Hilliard and Tolman.


title: On a local characterization of pseudoconvex domains

abstract:
  Pseudoconvexity of a domain in $\Bbb C^n$ is described in terms of the
existence of a locally defined plurisubharmonic/holomorphic function near any
boundary point that is unbounded at the point.


title: Field theory of bi- and tetracritical points: Statics

abstract:
  We calculate the static critical behavior of systems of $O(n_\|)\oplus
O(n_\perp)$ symmetry by renormalization group method within the minimal
subtraction scheme in two loop order. Summation methods lead to fixed points
describing multicritical behavior. Their stability boarder lines in the space
of order parameter components $n_\|$ and $n_\perp$ and spatial dimension $d$
are calculated. The essential features obtained already in two loop order for
the interesting case of an antiferromagnet in a magnetic field ($n_\|=1$,
$n_\perp=2$) are the stability of the biconical fixed point and the
neighborhood of the stability border lines to the other fixed points leading to
very small transient exponents. We are also able to calculate the flow of
static couplings, which allows to consider the attraction region. Depending on
the nonuniversal background parameters the existence of different multicritical
behavior (bicritical or tetracritical) is possible including a triple point.


title: Can the cosmological "constant" run? - It may run

abstract:
  Using standard quantum field theory, we discuss several theoretical aspects
of the possible running of the cosmological constant (CC) term in Einstein's
equations. The basic motivation for the present work is to emphasize that this
possibility should also be taken into account when considering dynamical models
for the dark energy (DE), which are nowadays mainly focused on identifying the
DE with the energy density associated to one or more ad hoc scalar fields. At
the same time, we address some recent criticisms that have been published (or
privately communicated to us) attempting to cast doubts on the fundamental
possibility of such running. In this work, we argue that while there is no
comprehensive proof of the CC running, there is no rigorous proof of the
non-running either. In particular, some purported "non-running theorem"
recently adduced in the literature is, in our opinion, completely insubstantial
and formally incorrect. The way to the CC running is, therefore, still open and
we take here the opportunity to present a pedagogical review of the present
state of the art in this field, including a a brief historical account.


title:
Smooth Structures and Normalized Ricci Flows on Non-Simply Connected
  Four-Manifolds

abstract:
  A solution to the normalized Ricci flow is called non-singular if it exists
for all time with uniformly bounded sectional curvature. By using the
techniques developed by the present authors, we study the existence or
non-existence of non-singular solutions of the normalized Ricci flow on
4-manifolds with non-trivial fundamental group and the relation with the smooth
structures. For example, we prove that, for any finite cyclic group ${\mathbb
Z}_{d}$, where $d>1$, there exists a compact topological 4-manifold $X$ with
fundamental group ${\mathbb Z}_{d}$, which admits at least one smooth structure
for which non-singular solutions of the normalized Ricci flow exist, but also
admits infinitely many distinct smooth structures for which {\it no}
non-singular solution of the normalized Ricci flow exists.
  Related non-existence results on non-singular solutions are also proved.
Among others, we show that there are no non-singular $\ZZ_d-$equivariant
solutions to the normalized Ricci flow on appropriate connected sums of $\bcp
^2$s and $\cpb $s ($d>1$).


title: A generalization of the Widder potential transform and applications

abstract:
  In the present paper the authors consider the $\mathcal{P}_{\nu,2}$-transform
as a generalization of the Widder potential transform and the Glasser
transform. The $\mathcal{P}_{\nu,2}$-transform is obtained as an iteration of
the the $\mathcal{L}_{2}$-transform with itself. Many identities involving
these transforms are given. By making use of these identities, a number of new
Parseval-Goldstein type identities are obtained for these and many other
well-known integral transforms. The identities proven in this paper are shown
to give rise to useful corollaries for evaluating infinite integrals of special
functions. Some examples are also given as illustration of the results
presented here.


title: Crossing the Cosmological Constant Line on a Warped DGP Brane

abstract:
  We study dynamics of the equation of state parameter for a dark energy
component non-minimally coupled to induced gravity on a warped DGP brane. We
show that there are appropriate domains of the model parameters space that
account for crossing of the phantom divide line. This crossing, which is
possible for both branches of the scenario, depends explicitly on the values of
the non-minimal coupling and warp factor. The effect of warp factor appears in
the value of the redshift parameter at which phantom divide line crossing
occurs.


title: Double shuffle relation for associators

abstract:
  It is proved that Drinfel'd's pentagon equation implies the generalized
double shuffle relation. As a corollary, an embedding from the
Grothendieck-Teichm\"uller group $GRT_1$ into Racinet's double shuffle group
$DMR_0$ is obtained, which settles the project of Deligne-Terasoma. It is also
proved that the gamma factorization formula follows from the generalized double
shuffle relation.


title:
Stellar Population Constraints on the Dark Matter Content and Origin of
  Ultra-Compact Dwarf Galaxies

abstract:
  We analyse intermediate-resolution VLT FLAMES/Giraffe spectra of six
ultra-compact dwarf (UCD) galaxies in the Fornax cluster. We obtained velocity
dispersions and stellar population properties by full spectral fitting against
PEGASE.HR models. Objects span a large range of metallicities (-0.95 to -0.23
dex), 4 of them are older than 8 Gyr. Comparison of the stellar and dynamical
masses suggests that UCDs have little dark matter at best. For one object,
UCD3, the Salpeter initial mass function (IMF) results in the stellar mass
significantly exceeding the dynamical one, whereas for the Kroupa IMF the
values coincide. Although, this object may have peculiar dynamics or/and
stellar populations, the Kroupa IMF seems more realistic. We find that UCDs lie
well above the metallicity-luminosity relation of early-type galaxies. The same
behaviour is demonstrated by some of the massive Milky Way globular clusters,
known to contain composite stellar populations. Our results support two
following UCD formation scenarii: (1) tidal stripping of nucleated dwarf
elliptical galaxies; (2) formation of tidal superclusters in galaxy mergers. We
also discuss some of the alternative channels of the UCD formation binding them
to globular clusters.


title: Flux networks in metabolic graphs

abstract:
  A metabolic model can be represented as bipartite graph comprising linked
reaction and metabolite nodes. Here it is shown how a network of conserved
fluxes can be assigned to the edges of such a graph by combining the reaction
fluxes with a conserved metabolite property such as molecular weight. A similar
flux network can be constructed by combining the primal and dual solutions to
the linear programming problem that typically arises in constraint-based
modelling. Such constructions may help with the visualisation of flux
distributions in complex metabolic networks. The analysis also explains the
strong correlation observed between metabolite shadow prices (the dual linear
programming variables) and conserved metabolite properties. The methods were
applied to recent metabolic models for Escherichia coli, Saccharomyces
cerevisiae, and Methanosarcina barkeri. Detailed results are reported for E.
coli; similar results were found for the other organisms.


title:
Anomalous WW $\gamma$ coupling in photon-induced processes using forward
  detectors at the LHC

abstract:
  We present a new method to test the Standard Model expectations at the LHC
using photon-induced $WW$ production. Both $W$ decay in the main ATLAS or CMS
detectors while scattered protons are measured in forward detectors. The
sensitivity to anomalous $WW\gamma$ triple gauge coupling can be improved by
more than a factor 5 or 30 compared to the present LEP or Tevatron sensitivity
respectively.


title: Elastic nonlinearities in a one-dimensional model of fracture

abstract:
  The dynamics of rapid brittle cracks is commonly studied in the framework of
linear elastic fracture mechanics where nonlinearities are neglected. However,
recent experimental and theoretical work demonstrated explicitly the importance
of elastic nonlinearities in fracture dynamics. We study two simple
one-dimensional models of fracture in order to gain insights about the role of
elastic nonlinearities and the implications of their exclusion in the common
linear elastic approximation. In one model we consider the decohesion of a
nonlinear elastic membrane from a substrate. In a second model we follow the
philosophy of linear elastic fracture mechanics and study a linearized version
of the nonlinear model. By analyzing the steady state solutions, the
velocity-load relations and the response to perturbations of the two models we
show that the linear approximation fails at finite crack tip velocities. We
highlight certain features of the breakdown of the linear theory and discuss
possible implications of our results to higher dimensional systems.


title: Thermodynamics on Noncommutative Geometry in Coherent State Formalism

abstract:
  The thermodynamics of ideal gas on the noncommutative geometry in the
coherent state formalism is investigated. We first evaluate the statistical
interparticle potential and see that there are residual "attraction (repulsion)
potential" between boson (fermion) in the high temperature limit. The
characters could be traced to the fact that, the particle with mass $m$ in
noncommutative thermal geometry with noncommutativity $\theta$ and temperature
$T$ will correspond to that in the commutative background with temperature
$T(1+kTm\theta)^{-1}$. Such a correspondence implies that the ideal gas energy
will asymptotically approach to a finite limiting value as that on commutative
geometry at $T_\theta= (km\theta)^{-1}$. We also investigate the squeezed
coherent states and see that they could have arbitrary mean energy. The thermal
properties of those systems are calculated and compared to each other. We find
that the heat capacity of the squeezed coherent states of boson and fermion on
the noncommutative geometry have different values, contrast to that on the
commutative geometry.


title: Metamagnetic transition in EuFe$_2$As$_2$ single crystals

abstract:
  We report the measurements of anisotropic magnetization and magnetoresistance
on single crystals of EuFe$_2$As$_2$, a parent compound of ferro-arsenide
high-temperature superconductor. Apart from the antiferromagnetic (AFM)
spin-density-wave transition at 186 K associated with Fe moments, the compound
undergoes another magnetic phase transition at 19 K due to AFM ordering of
Eu$^{2+}$ spins ($J=S=7/2$). The latter AFM state exhibits metamagnetic
transition under magnetic fields. Upon applying magnetic field with $H\parallel
c$ at 2 K, the magnetization increases linearly to 7.0 $\mu_{B}$/f.u. at
$\mu_{0}H$=1.7 T, then keeps at this value of saturated Eu$^{2+}$ moments under
higher fields. In the case of $H\parallel ab$, the magnetization increases
step-like to 6.6 $\mu_{B}$/f.u. with small magnetic hysteresis. A metamagnetic
phase was identified with the saturated moments of 4.4 $\mu_{B}$/f.u. The
metamagnetic transition accompanies with negative in-plane magnetoresistance,
reflecting the influence of Eu$^{2+}$ moments ordering on the electrical
conduction of FeAs layers. The results were explained in terms of
spin-reorientation and spin-reversal based on an $A$-type AFM structure for
Eu$^{2+}$ spins. The magnetic phase diagram has been established.


title: Towards nonlinear quantum Fokker-Planck equations

abstract:
  It is demonstrated how the equilibrium semiclassical approach of Coffey et
al. can be improved to describe more correctly the evolution. As a result a new
semiclassical Klein-Kramers equation for the Wigner function is derived, which
remains quantum for a free quantum Brownian particle as well. It is transformed
to a semiclassical Smoluchowski equation, which leads to our semiclassical
generalization of the classical Einstein law of Brownian motion derived before.
A possibility is discussed how to extend these semiclassical equations to
nonlinear quantum Fokker-Planck equations based on the Fisher information.


title:
Strengthened large deviations for rational maps and full shifts, with
  unified proof

abstract:
  For any hyperbolic rational map and any net of Borel probability measures on
the space of Borel probability measures on the Julia set, we show that this net
satisfies a strong form of the large deviation principle with a rate function
given by the entropy map if and only if the large deviation and the pressure
functionals coincide. To each such principles corresponds a new expression for
the entropy of invariant measures. We give the explicit form of the rate
function of the corresponding large deviation principle in the real line for
the net of image measures obtained by evaluating the function $\log|T'|$. These
results are applied to various examples including those considered in the
literature where only upper bounds have been proved. The proof rests on some
entropy-approximation property (independent of the net of measures), which in a
suitable formulation, is nothing but the hypothesis involving exposed points in
Baldi's theorem. In particular, it works verbatim for general dynamical
systems. After stating the corresponding general version, as another example we
consider the multidimensional full shift for which the above property has been
recently proved, and we establish large deviation principles for nets of
measures analogous to those of the rational maps case.


title: Effect of Zn doping on magnetic order and superconductivity in LaFeAsO

abstract:
  We report Zn-doping effect in the parent and F-doped LaFeAsO oxy-arsenides.
Slight Zn doping in LaFe$_{1-x}$Zn$_{x}$AsO drastically suppresses the
resistivity anomaly around 150 K associated with the antiferromagnetic (AFM)
spin density wave (SDW) in the parent compound. The measurements of magnetic
susceptibility and thermopower confirm further the effect of Zn doping on AFM
order. Meanwhile Zn doping does not affect or even enhances the $T_c$ of
LaFe$_{1-x}$Zn$_{x}$AsO$_{0.9}$F$_{0.1}$, in contrast to the effect of Zn
doping in high-$T_c$ cuprates. We found that the solubility of Zn content ($x$)
is limited to less than 0.1 in both systems and further Zn doping (i.e., $x$
$\geq$ 0.1) causes phase separation. Our study clearly indicates that the
non-magnetic impurity of Zn$^{2+}$ ions doped in the Fe$_2$As$_2$ layers
affects selectively the AFM order, and superconductivity remains robust against
the Zn doping in the F-doped superconductors.


title:
Use of a nanoindentation fatigue test to characterize the
  ductile-brittle transition

abstract:
  When considering grinding of minerals, scaling effect induces competition
between plastic deformation and fracture in brittle solids. The competition can
be sketched by a critical size of the material, which characterizes the
ductile-brittle transition. A first approach using Vickers indentation gives a
good approximation of the critical size through an extrapolation from the
macroscopic to the microscopic scales. Nanoindentation tests confirm this
experimental value. According to the grain size compared to the indent size, it
can reasonably be said that the mode of damage is deformation-induced
intragranular microfracture. This technique also enables to perform cyclic
indentations to examine calcite fatigue resistance. Repeated loadings with a
nanoindenter on CaCO3 polycrystalline samples produce cumulative mechanical
damage. It is also shown that the transition between ductile and brittle
behaviour depends on the number of indentation cycles. The ductile domain can
be reduced when the material is exposed to a fatigue process.


title:
Unified approach to structure factors and neutrino processes in nucleon
  matter

abstract:
  We present a unified approach to neutrino processes in nucleon matter based
on Landau's theory of Fermi liquids that includes one- and
two-quasiparticle-quasihole pair states as well as mean-field effects. We show
how rates of neutrino processes involving two nucleons may be calculated in
terms of the collision integral in the Landau transport equation for
quasiparticles. Using a relaxation time approximation, we solve the transport
equation for density and spin-density fluctuations and derive a general form
for the response functions. We apply our approach to neutral-current processes
in neutron matter, where the spin response function is crucial for calculations
of neutrino elastic and inelastic scattering, neutrino-pair bremsstrahlung and
absorption from strongly-interacting nucleons. We calculate the relaxation
rates using modern nuclear interactions and including many-body contributions,
and find that rates of neutrino processes are reduced compared with estimates
based on the one-pion exchange interaction, which is used in current
simulations of core-collapse supernovae.


title: Flavorful $Z^\prime$ signatures at LHC and ILC

abstract:
  There are lots of new physics models which predict an extra neutral gauge
boson, referred as Z'-boson. In a certain class of these new physics models,
the Z'-boson has flavor-dependent couplings with the fermions in the Standard
Model (SM). Based on a simple model in which couplings of the SM fermions in
the third generation with the Z'-boson are different from those of the
corresponding fermions in the first two generations, we study the signatures of
Z'-boson at the Large Hadron Collider (LHC) and the International Linear
Collider (ILC). We show that at the LHC, the Z'-boson with mass around 1 TeV
can be produced through the Drell-Yan processes and its dilepton decay modes
provide us clean signatures not only for the resonant production of Z'-boson
but also for flavor-dependences of the production cross sections. We also study
fermion pair productions at the ILC involving the virtual Z'-boson exchange.
Even though the center-of-energy of the ILC is much lower than a Z'-boson mass,
the angular distributions and the forward-backward asymmetries of fermion pair
productions show not only sizable deviations from the SM predictions but also
significant flavor-dependences.


title:
Antimatter cosmic rays from dark matter annihilation: First results from
  an N-body experiment

abstract:
  [Abridged]. We take advantage of the galaxy-like 3D dark matter map extracted
from the HORIZON Project results to calculate the positron and antiproton
fluxes from dark matter annihilation, in a model-independent approach as well
as for dark matter particle benchmarks relevant at the LHC scale (from
supersymmetric and extra-dimensional theories). Such a study is dedicated to a
better estimate of the theoretical uncertainties affecting predictions, while
the PAMELA and GLAST satellites are currently taking data which will soon
provide better observational constraints. We discuss the predictions of the
antiproton and positron fluxes, and of the positron fraction as well, as
compared to the current data. We finally discuss the limits of the Nbody
framework in describing the dark matter halo of our Galaxy.


title:
Measurement of Semileptonic B Decays into Orbitally Excited Charmed
  Mesons

abstract:
  We present a study of B decays into semileptonic final states containing
charged and neutral $D_1(2420)$ and $D_2^*(2460)$. The analysis is based on a
data sample of $208 fb^{-1}$ collected at the $\Upsilon(4S)$ resonance with the
BaBar detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. With a
simultaneous fit to four different decay chains, the semileptonic branching
fractions are extracted from measurements of the mass difference $\Delta
m=m(D**)-m(D)$ distributions. Product branching fractions are determined to be
$BR(B^+ -> D_1^0 \ell^+ \nu_{\ell}) x BR(D_1^0 -> D*^+ \pi^-) = (2.97 +/- 0.17
+/- 0.17) x 10^{-3}$, $BR(B^+ -> D_2^{*0} \ell^+ \nu_{\ell}) x BR(D_2^{*0} ->
D^{(*)+} \pi^-) = (2.29 +/- 0.23 +/- 0.21) x 10^{-3}$, $BR(B^0 -> D_1^- \ell^+
\nu_{\ell}) x BR(D_1^- -> D*^0 \pi^-) = (2.78 +/- 0.24 +/- 0.25) 10^{-3}$ and
$BR(B^0 -> D_2^{*-} \ell^+ \nu_{\ell}) x BR(D_2^{*-} -> D^{(*)0} \pi^-) = (1.77
+/- 0.26 +-/ 0.11) 10^{-3}$. In addition we measure the branching ratio
$\Gamma(D_2^* -> D \pi^-)/\Gamma(D_2^* -> D^{(*)} \pi^-) = 0.62 +/- 0.03 +/-
0.02$.


title: Employing trapped cold ions to verify the quantum Jarzynski equality

abstract:
  We propose a scheme to investigate the nonequilibrium work distribution of a
quantum particle under well controlled transformations of the external
potential, exploiting the versatility of a single ion in a segmented linear
Paul trap. We describe in detail how the motional quantum state of a single ion
can be prepared, manipulated and finally read out to fully determine the free
energy difference in both harmonic and anharmonic potentials. Uniquely to our
system, we show how an ion may be immersed in an engineered laser--field
reservoir. Trapped ions therefore represent an ideal tool for investigating the
Jarzynski equality in open and closed quantum systems.


title:
Origin of the reduced exchange bias in epitaxial FeNi(111)/CoO(111)
  bilayer

abstract:
  We have employed Soft and Hard X-ray Resonant Magnetic Scattering and
Polarised Neutron Diffraction to study the magnetic interface and the bulk
antiferromagnetic domain state of the archetypal epitaxial
Ni$_{81}$Fe$_{19}$(111)/CoO(111) exchange biased bilayer. The combination of
these scattering tools provides unprecedented detailed insights into the still
incomplete understanding of some key manifestations of the exchange bias
effect. We show that the several orders of magnitude difference between the
expected and measured value of exchange bias field is caused by an almost
anisotropic in-plane orientation of antiferromagnetic domains. Irreversible
changes of their configuration lead to a training effect. This is directly seen
as a change in the magnetic half order Bragg peaks after magnetization
reversal. A 30 nm size of antiferromagnetic domains is extracted from the width
the (1/2 1/2 1/2) antiferromagnetic magnetic peak measured both by neutron and
x-ray scattering. A reduced blocking temperature as compared to the measured
antiferromagnetic ordering temperature clearly corresponds to the blocking of
antiferromagnetic domains. Moreover, an excellent correlation between the size
of the antiferromagnetic domains, exchange bias field and frozen-in spin ratio
is found, providing a comprehensive understanding of the origin of exchange
bias in epitaxial systems.


title: Canted-spin-caused electric dipoles: a local symmetry theory

abstract:
  A pair of magnetic atoms with canted spins Sa, Sb can give rise to an
electric dipole moment P. Several forms for the behavior of such a moment have
appeared in the theoretical literature, some of which have been invoked to
explain experimental results found in various multiferroic materials. The forms
specifically are P1 ~ R x (Sa x Sb); P2 ~ Sa x Sb, and P3 ~ Sa (R . Sa) - Sb (R
. Sb), where R is the relative position of the atoms and Sa, Sb are unit
vectors. To unify and generalize these various forms we consider P as the most
general quadratic function of the spin components that vanishes whenever Sa and
Sb are collinear, i.e. we consider the most general expressions that require
spin canting. The study reveals new forms. We generalize to the vector P,
Moriya's symmetry considerations regarding the (scalar) Dzyaloshinskii-Moriya
energy D. Sa x Sb (which led to restrictions on D). This provides a rigorous
symmetry argument which shows that P1 is allowed no matter how high the
symmetry of the atoms plus environment, and gives restrictions for all other
contributions. The analysis leads to the suggestion of terms omitted in the
existing microscopic models, suggests a new mechanism behind the
ferroelectricity found in the 'proper screw structure' of CuXO2, X=Fe, Cr, and
predicts an unusual antiferroelectric ordering in the antiferromagnetically and
ferroelectrically ordered phase of RbFe(MoO4)2.


title: Non-standard approximations of the Ito-map

abstract:
  The Wong-Zakai theorem asserts that ODEs driven by "reasonable" (e.g.
piecewise linear) approximations of Brownian motion converge to the
corresponding Stratonovich stochastic differential equation. With the aid of
rough path analysis, we study "non-reasonable" approximations and go beyond a
well-known criterion of [Ikeda--Watanabe, North Holland 1989] in the sense that
our result applies to perturbations on all levels, exhibiting additional drift
terms involving any iterated Lie brackets of the driving vector fields. In
particular, this applies to the approximations by McShane ('72) and Sussmann
('91). Our approach is not restricted to Brownian driving signals. At last,
these ideas can be used to prove optimality of certain rough path estimates.


title:
Geometric quantization of integrable systems with hyperbolic
  singularities

abstract:
  We construct the geometric quantization of a compact surface using a singular
real polarization coming from an integrable system. Such a polarization always
has singularities, which we assume to be of nondegenerate type. In particular,
we compute the effect of hyperbolic singularities, which make an
infinite-dimensional contribution to the quantization, thus showing that this
quantization depends strongly on polarization.


title: A 3D discrete model of the diaphragm and human trunk

abstract:
  In this paper, a 3D discrete model is presented to model the movements of the
trunk during breathing. In this model, objects are represented by physical
particles on their contours. A simple notion of force generated by a linear
actuator allows the model to create forces on each particle by way of a
geometrical attractor. Tissue elasticity and contractility are modeled by local
shape memory and muscular fibers attractors. A specific dynamic MRI study was
used to build a simple trunk model comprised of by three compartments: lungs,
diaphragm and abdomen. This model was registered on the real geometry.
Simulation results were compared qualitatively as well as quantitatively to the
experimental data, in terms of volume and geometry. A good correlation was
obtained between the model and the real data. Thanks to this model, pathology
such as hemidiaphragm paralysis can also be simulated.


abstract:
  The paper sets forth comprehensive basics of Discrete Thermodynamics of
Chemical Equilibria (DTD), developed by the author during the last decade and
spread over series of publications. Based on the linear equations of
irreversible thermodynamics, De Donder's definition of the thermodynamic force,
and the Le Chatelier principle, DTD brings forward a notion of chemical
equilibrium as a balance of internal and external thermodynamic forces, acting
against a chemical system. The basic expression of DTD is a logistic map that
ties together energetic characteristics of the chemical transformation in the
system, its deviation from true thermodynamic equilibrium, and the sum of
thermodynamic forces, causing that deviation. System deviation from
thermodynamic equilibrium is the major variable of the theory. Solutions to the
basic map define the chemical system domain of states comprising bifurcation
diagrams with four areas, from true thermodynamic equilibrium to chaos, having
specific distinctive meaning for chemical systems. The theory is derived from
the currently recognized ideas of chemical thermodynamics and binds classical
and contemporary thermodynamics of chemical equilibria into a unique concept.
DTD opens new opportunities in understanding and analysis of equilibria in
chemical systems. Some new results, included in the paper, have never been
published before.


title:
Contamination cannot explain the lack of large-scale power in the cosmic
  microwave background radiation

abstract:
  Several anomalies appear to be present in the large-angle cosmic microwave
background (CMB) anisotropy maps of WMAP. One of these is a lack of large-scale
power. Because the data otherwise match standard models extremely well, it is
natural to consider perturbations of the standard model as possible
explanations. We show that, as long as the source of the perturbation is
statistically independent of the source of the primary CMB anisotropy, no such
model can explain this large-scale power deficit. On the contrary, any such
perturbation always reduces the probability of obtaining any given low value of
large-scale power. We rigorously prove this result when the lack of large-scale
power is quantified with a quadratic statistic, such as the quadrupole moment.
When a statistic based on the integrated square of the correlation function is
used instead, we present strong numerical evidence in support of the result.
The result applies to models in which the geometry of spacetime is perturbed
(e.g., an ellipsoidal Universe) as well as explanations involving local
contaminants, undiagnosed foregrounds, or systematic errors. Because the
large-scale power deficit is arguably the most significant of the observed
anomalies, explanations that worsen this discrepancy should be regarded with
great skepticism, even if they help in explaining other anomalies such as
multipole alignments.


title:
Resonance signals in pion-nucleon scattering from speed plots and time
  delay

abstract:
  We compare a number of methods used to locate resonances. These include the
speed plot, the time-delay method of Eisenbud and Wigner, the time-delay matrix
of Smith, and a modification by Ohmura. Numerical results show a consistency
not previously reported. One time delay method gives the most consistent
results, supporting the conclusions of a recent theoretical study.


title: Threefolds of order one in the six-quadric

abstract:
  Consider the smooth quadric Q_6 in P^7. The middle homology group H_6(Q_6,Z)
is two-dimensional with a basis given by two classes of linear subspaces. We
classify all threefolds of bidegree (1,p) inside Q_6.


title: Proton and Neutrino Extragalactic Astronomy

abstract:
  The study of extragalactic sources of high energy radiation via the direct
measurement of the proton and neutrino fluxes that they are likely to emit is
one of the main goals for the future observations of the recently developed air
showers detectors and neutrino telescopes. In this work we discuss the relation
between the inclusive proton and neutrino signals from the ensemble of all
sources in the universe, and the resolved signals from the closest and
brightest objects. We also compare the sensitivities of proton and neutrino
telescopes and comment on the relation between these two new astronomies.


title: Quantized dual graded graphs

abstract:
  We study quantized dual graded graphs, which are graphs equipped with linear
operators satisfying the relation DU - qUD = rI. We construct examples based
upon: the Fibonacci poset, permutations, standard Young tableau, and plane
binary trees.


title:
Observation of a novel orbital selective Mott transition in
  Ca$_{1.8}$Sr$_{0.2}$RuO$_4$

abstract:
  Electrons in a simple correlated system behave either as itinerant charge
carriers or as localized moments. However, there is growing evidence for the
coexistence of itinerant electrons and local moments in transition metals with
nearly degenerate $d$-orbitals. It demands one or more selective electron
orbitals undergo the Mott transition while the others remain itinerant. Here we
report the first observation of such an orbital selective Mott transition
(OSMT) in Ca$_{1.8}$Sr$_{0.2}$RuO$_4$ by angle-resolved photoemission
spectroscopy (ARPES). While we observed two sets of dispersing bands and Fermi
surface associated with the doubly-degenerate $d_{yz}$ and $d_{zx}$ orbitals,
the Fermi surface associated with the wider $d_{xy}$ band is missing, a
consequence of selective Mott localization. Our theoretical calculations
demonstrate that this novel OSMT is mainly driven by the combined effects of
interorbital carrier transfer, superlattice potential, and orbital degeneracy,
whereas the bandwidth difference plays a less important role.


title: Towards a Process for Developing Maintenance Tools in Academia

abstract:
  Building of tools--from simple prototypes to industrial-strength
applications--is a pervasive activity in academic research. When proposing a
new technique for software maintenance, effective tool support is typically
required to demonstrate the feasibility and effectiveness of the approach.
However, even though tool building is both pervasive and requiring significant
time and effort, it is still pursued in an ad hoc manner. In this paper, we
address these issues by proposing a dedicated development process for tool
building that takes the unique characteristics of an academic research
environment into account. We first identify process requirements based on a
review of the literature and our extensive tool building experience in the
domain of maintenance tools. We then outline a process framework based on work
products that accommodates the requirements while providing needed flexibility
for tailoring the process to account for specific tool building approaches and
project constraints. The work products are concrete milestones of the process,
tracking progress, rationalizing (design) decisions, and documenting the
current state of the tool building project. Thus, the work products provide
important input for strategic project decisions and rapid initiation of new
team members. Leveraging a dedicated tool building process promises tools that
are designed, build, and maintained in a more disciplined, predictable and
efficient manner.


title: On implicit ODEs with hexagonal web of solutions

abstract:
  Solutions of an implicit ODE form a web. Already for cubic ODEs the 3-web of
solutions has a nontrivial local invariant, namely the curvature form. Thus any
local classification of implicit ODEs necessarily has functional moduli if no
restriction on the class of ODEs is imposed. Here the most symmetric case of
hexagonal 3-web of solutions is discussed, i.e. the curvature is supposed to
vanish identically. A finite list of normal forms is established under some
natural regularity assumptions. Geometrical meaning of these assumptions is
that the surface, defined by ODE in the space of 1-jets, is smooth as well as
the criminant, which is the critical set of this surface projection to the
plane.


title: Ultra-high energy cosmic rays from radio galaxies revisited

abstract:
  A striking concentration of ultra-high energy cosmic ray (UHECR) events
observed by the Pierre Auger Observatory around the direction of the nearby
radio galaxy Centaurus A revives the idea that radio galaxies may be dominant
sources of UHECR. In this paper, we give a brief overview about processes which
may accelerate protons and nuclei in radio galaxies, and their relation to jet
power, radio morphology and cosmic source density. We argue that, except for
the most powerful FR-II radio galaxies, processes in radio lobes are unlikely
to explain the origin of UHECR. However, Fermi acceleration of protons at
internal shocks in the "blazarzone" of all radio galaxies, and their
photohadronic conversion into neutrons, may lead to the ejection of
"UHECR-beams", which remain collimated over several Mpc. Consequences of this
hypothesis for the interpretation of the UHECR event distribution, in
particular for the special case of Centaurus A, are discussed.


title: Livsic theorem for matrix cocycles

abstract:
  We prove the Liv\v{s}ic Theorem for arbitrary $GL(m,\mathbb R)$ cocycles. We
consider a hyperbolic dynamical system $f : X \to X$ and a H\"older continuous
function $A: X \to GL(m,\mathbb R)$. We show that if $A$ has trivial periodic
data, i.e. $A(f^{n-1} p) ... A(fp) A(p) = Id$ for each periodic point $p=f^n
p$, then there exists a H\"older continuous function $C: X \to GL(m,\mathbb R)$
satisfying $A (x) = C(f x) C(x) ^{-1}$ for all $x \in X$. The main new
ingredients in the proof are results of independent interest on relations
between the periodic data, Lyapunov exponents, and uniform estimates on growth
of products along orbits for an arbitrary H\"older function $A$.


title: Cosmological Measures without Volume Weighting

abstract:
  Many cosmologists (myself included) have advocated volume weighting for the
cosmological measure problem, weighting spatial hypersurfaces by their volume.
However, this often leads to the Boltzmann brain problem, that almost all
observations would be by momentary Boltzmann brains that arise very briefly as
quantum fluctuations in the late universe when it has expanded to a huge size,
so that our observations (too ordered for Boltzmann brains) would be highly
atypical and unlikely. Here it is suggested that volume weighting may be a
mistake. Volume averaging is advocated as an alternative. One consequence may
be a loss of the argument that eternal inflation gives a nonzero probability
that our universe now has infinite volume.


title: About summability of Fourier-Laplace series

abstract:
  In this paper we study the almost everywhere convergence of the expansions
related to the self-adjoint extension of the Laplace operator. The sufficient
conditions for summability is obtained.
  For the orders of Riesz means, which greater than critical index
$\frac{N-1}{2}$ we established the estimation for maximal operator of the Riesz
means. Note that when order $\alpha$ of Riesz means is less than critical index
then for establish of the almost everywhere convergence requests to use other
methods form proving negative results. We have constructed different method of
summability of Laplace series, which based on spectral expansions property of
self-adjoint Laplace-Beltrami operator on the unit sphere


title: Non-malleable encryption of quantum information

abstract:
  We introduce the notion of "non-malleability" of a quantum state encryption
scheme (in dimension d): in addition to the requirement that an adversary
cannot learn information about the state, here we demand that no controlled
modification of the encrypted state can be effected.
  We show that such a scheme is equivalent to a "unitary 2-design" [Dankert et
al.], as opposed to normal encryption which is a unitary 1-design. Our other
main results include a new proof of the lower bound of (d^2-1)^2+1 on the
number of unitaries in a 2-design [Gross et al.], which lends itself to a
generalization to approximate 2-design.
  Furthermore, while in prime power dimension there is a unitary 2-design with
=< d^5 elements, we show that there are always approximate 2-designs with
O(epsilon^{-2} d^4 log d) elements.


title: A new search for variable stars in the globular cluster NGC 6366

abstract:
  New CCD photometry of NGC 6366 has lead to the discovery of some variable
stars. Two possible Anomalous Cepheids (or Pop II Cepheids), three long period
variables, one SX Phe and one eclipsing binary have been found. Also a list of
10 candidate variables is reported. The light curve of the RRab star, V1, has
been decomposed into its Fourier harmonics, and the Fourier parameters were
used to estimate the star's metallicity and distance; [Fe/H] = -0.87 +- 0.14
and d = 3.2 +- 0.1 kpc. It is argued that V1 may not be a member of the cluster
but rather a more distant object. If this is so, an upper limit for the
distance to the cluster of 2.8 +- 0.1 kpc can be estimated. The P-L
relationship for SX Phe stars and the identified modes in the newly discovered
SX Phe variable, V6, allow yet another independent determination of the
distance to the cluster of d = 2.7 \+- 0.1 kpc. The M_V - {\rm [Fe/H]}
relationship for RR Lyrae stars is addressed and the case of V1 is discussed.


title:
Comments on gauge invariant overlaps for marginal solutions in open
  string field theory

abstract:
  We calculate the gauge invariant overlaps for
Schnabl/Kiermaier-Okawa-Rastelli-Zwiebach's marginal solution with nonsingular
current. The obtained formula is the same as that for
Fuchs-Kroyter-Potting/Kiermaier-Okawa's marginal solution, which was already
computed by Ellwood. Our result is consistent with the expectation that they
may be gauge equivalent. We also comment on a gauge invariant overlap for
rolling tachyon solutions in cubic open string field theory.


title:
Elliptic flow fluctuations and correlations in Au+Au collisions at
  $\sqrt{s_{NN}}=200$ GeV

abstract:
  In this talk, we report an analysis of elliptic flow ($v_2$), non-flow
($\delta_{2}$), and $v_2$ fluctuations ($\sigma_{v_{2}}$) for the STAR
collaboration at middle rapidity in $\sqrt{s_{_{NN}}}=200$ GeV Au+Au
collisions. We compare the results to models of the fluctuations in the initial
eccentricity of the overlap zone.


title:
The Kuratowski covering conjecture for graphs of order < 10 for the
  nonorientable surfaces of genus 3 and 4

abstract:
  Kuratowski proved that a finite graph embeds in the plane if it does not
contain a subdivision of either K_5 or K_{3,3}, called Kuratowski subgraphs. A
conjectured generalization of this result to all nonorientable surfaces says
that a finite minimal forbidden subgraph for the nonorientable surface of genus
g can be written as the union of g+1 Kuratowski subgraphs such that the union
of each pair of these fails to embed in the projective plane, the union of each
triple of these fails to embed in the Klein bottle if g >= 2, and the union of
each triple of these fails to embed in the torus if g >= 3. We show that this
conjecture is true for all minimal forbidden subgraphs of order < 10 for the
nonorientable surfaces of genus 3 and 4.