title:
The Light Quanta Modulated Physiological Response of Brassica Juncea
  Seedlings Subjected to Ni(II) Stress

abstract:
  This work is a study of the inter-relationship between parameters that
principally affect metal up-take in the plant. The relationships between the
concentration of metal in the growth medium, Cs, the concentration of metal
absorbed by the plant, Cp, and the total biomass achieved, M, all of which are
factors relevant to the efficiency of phytoremediation of the plant, have been
investigated via the macro-physiological response of Brassica juncea seedlings
to Ni(II) stress. The factorial growth experiments treated the Ni(II)
concentration in the agar gel and the diurnal light quanta (DLQ) as
independently variable parameters. Observations included the evidence of light
enhancement of Ni toxicity at the root as well as at the whole plant level, the
shoot mass index as a possible indicator of shoot metal sequestration in B.
juncea, the logarithmic variation of Cp with Cs and the power-law dependence of
M on Cp. The sum total of these observations indicate that for the metal
accumulator B. juncea with regard to its capacity to accumulate Ni, the overall
metabolic nature of the plant is important; neither rapid biomass increase nor
a high metal concentration capability favor the removal of high metal mass from
the medium, but rather the plant with the moderate photosynthetically driven
biomass growth and moderate metal concentrations demonstrated the ability to
remove the maximum mass of metal from the medium. The implications of these
observations in the context of the perceived need in phytoremediation
engineering to maximize Cp and M simultaneously in the same plant, are
discussed.


title:
Decay and non-decay of the local energy for the wave equation in the De
  Sitter - Schwarzschild metric

abstract:
  We describe an expansion of the solution of the wave equation in the De
Sitter - Schwarzschild metric in terms of resonances. The main term in the
expansion is due to a zero resonance. The error term decays polynomially if we
permit a logarithmic derivative loss in the angular directions and
exponentially if we permit an small derivative loss in the angular directions.


title: R-Matrix Poisson Algebras and Their Deformations

abstract:
  We classify in this paper Poisson structures on modules over semisimple Lie
algebras arising from classical r-matrices. We then study their quantizations
and the relation to classical invariant theory.


title: Iterative quantum state transfer along a chain of nuclear spin qubits

abstract:
  Transferring quantum information between two qubits is a basic requirement
for many applications in quantum communication and quantum information
processing. In the iterative quantum state transfer (IQST) proposed by D.
Burgarth et al. [Phys. Rev. A 75, 062327 (2007)], this is achieved by a static
spin chain and a sequence of gate operations applied only to the receiving end
of the chain. The only requirement on the spin chain is that it transfers a
finite part of the input amplitude to the end of the chain, where the gate
operations accumulate the information. For an appropriate sequence of
evolutions and gate operations, the fidelity of the transfer can asymptotically
approach unity. We demonstrate the principle of operation of this transfer
scheme by implementing it in a nuclear magnetic resonance quantum information
processor.


title:
On the Construction of Zero Energy States in Supersymmetric Matrix
  Models IV

abstract:
  Simple recursion relations for zero energy states of supersymmetric matrix
models are derived by using an unconventional reducible representation for the
fermionic degrees of freedom.


title:
Lepton masses, mixings and FCNC in a minimal S_3-invariant extension of
  the Standard Model

abstract:
  The mass matrices of the charged leptons and neutrinos, previously derived in
a minimal S_3-invariant extension of the Standard Model, were reparametrized in
terms of their eigenvalues. We obtained explicit, analytical expressions for
all entries in the neutrino mixing matrix, V_PMNS, the neutrino mixing angles
and the Majorana phases as functions of the masses of charged leptons and
neutrinos in excellent agreement with the latest experimental values. The
resulting V_PMNS matrix is very close to the tri-bimaximal form of the neutrino
mixing matrix. We also derived explicit analytical expressions for the matrices
of the Yukawa couplings and computed the branching ratios of some selected
flavour changing neutral current processes as functions of the masses of the
charged leptons and the neutral Higgs bosons. We find that the S_3 x Z_2
flavour symmetry and the strong mass hierarchy of the charged leptons strongly
suppress the FCNC processes in the leptonic sector well below the present
experimental upper bounds by many orders of magnitude.


title: Dynamical Symmetries in Supersymmetric Matrix Models

abstract:
  We reveal a dynamical SU(2) symmetry in the asymptotic description of
supersymmetric matrix models. We also consider a recursive approach for
determining the ground state, and point out some additional properties of the
model(s).


title: A class of series acceleration formulae for Catalan's constant

abstract:
  In this note, we develop transformation formulae and expansions for the log
tangent integral, which are then used to derive series acceleration formulae
for certain values of Dirichlet L-functions, such as Catalan's constant. The
formulae are characterized by the presence of an infinite series whose general
term consists of a linear recurrence damped by the central binomial coefficient
and a certain quadratic polynomial. Typically, the series can be expressed in
closed form as a rational linear combination of Catalan's constant and pi times
the logarithm of an algebraic unit.


title:
On a certain continuity property of the residues of the poles of
  $\sum_{n \geq 1} \Lambda(n) e^{- \pi i q n } n^{-s}$ with respect to $q \in
  \mathbb{Q} \cap (0, 2)$

abstract:
  The purpose of this article is to present some result concerning the poles of
the series $\sum_{n \geq 1} \Lambda(n) e^{- \pi i q n } n^{-s}$, where $q$ is
rational and $\Lambda$ is the arithmetical Mangoldt $\Lambda$-function. A
certain continuity property of the residues of the poles of $M(s, q)$ with
respect to $q \in \mathbb{Q} \cap (0, 2)$ is discussed.


title: Ends in Uniform Spanning Forests

abstract:
  It has hitherto been known that in a transitive unimodular graph, each tree
in the wired spanning forest has only one end a.s. We dispense with the
assumptions of transitivity and unimodularity, replacing them with a much
broader condition on the isoperimetric profile that requires just slightly more
than uniform transience.


title:
Boundary Conditions for Scaled Random Matrix Ensembles in the Bulk of
  the Spectrum

abstract:
  A spectral average which generalises the local spacing distribution of the
eigenvalues of random $ N\times N $ hermitian matrices in the bulk of their
spectrum as $ N\to\infty $ is known to be a $\tau$-function of the fifth
Painlev\'e system. This $\tau$-function, $ \tau(s) $, has generic parameters
and is transcendental but is characterised by particular boundary conditions
about the singular point $s=0$, which we determine here. When the average
reduces to the local spacing distribution we find that $\tau$-function is of
the separatrix, or partially truncated type.


title: Towards an Explicit Model of D-brane Inflation

abstract:
  We present a detailed analysis of an explicit model of warped D-brane
inflation, incorporating the effects of moduli stabilization. We consider the
potential for D3-brane motion in a warped conifold background that includes
fluxes and holomorphically-embedded D7-branes involved in moduli stabilization.
Although the D7-branes significantly modify the inflaton potential, they do not
correct the quadratic term in the potential, and hence do not cause a uniform
change in the slow-roll parameter eta. Nevertheless, we present a simple
example based on the Kuperstein embedding of D7-branes, z_1=constant, in which
the potential can be fine-tuned to be sufficiently flat for inflation. To
derive this result, it is essential to incorporate the fact that the
compactification volume changes slightly as the D3-brane moves. We stress that
the compactification geometry dictates certain relationships among the
parameters in the inflaton Lagrangian, and these microscopic constraints impose
severe restrictions on the space of possible models. We note that the shape of
the final inflaton potential differs from projections given in earlier studies:
in configurations where inflation occurs, it does so near an inflection point.
Finally, we comment on the difficulty of making precise cosmological
predictions in this scenario. This is the companion paper to arXiv:0705.3837.


title: Astrometric Orbits for Hipparcos Stochastic Binaries

abstract:
  Taking advantage of an improved genetic optimization algorithm for fitting
unconstrained Kepler orbits to the Hipparcos intermediate astrometric data, we
obtain additional orbital solutions for 81 Hipparcos stars with previous
stochastic (failed) solutions. The sample includes astrophysically interesting
objects, including the old disk wide binary HIP 754, the nearby AGB star HIP
34922 (L2 Pup), and the nearby M2 dwarf HIP 5496 (GJ 54, at 8 pc from the Sun)
which has a resolved M dwarf companion.


title: Coverings of skew-products and crossed products by coactions

abstract:
  Consider a projective limit G of finite groups G_n. Fix a compatible family
\delta^n of coactions of the G_n on a C*-algebra A. From this data we obtain a
coaction \delta of G on A. We show that the coaction crossed product of A by
\delta is isomorphic to a direct limit of the coaction crossed products of A by
the \delta^n.
  If A = C*(\Lambda) for some k-graph \Lambda, and if the coactions \delta^n
correspond to skew-products of \Lambda, then we can say more. We prove that the
coaction crossed-product of C*(\Lambda) by \delta may be realised as a full
corner of the C*-algebra of a (k+1)-graph. We then explore connections with
Yeend's topological higher-rank graphs and their C*-algebras.


title: Amplitude equations for a system with thermohaline convection

abstract:
  The multiple scale expansion method is used to derive amplitude equations for
a system with thermohaline convection in the neighborhood of Hopf and Taylor
bifurcation points and at the double zero point of the dispersion relation. A
complex Ginzburg-Landau equation, a Newell-Whitehead-type equation, and an
equation of the $\phi^4$ type, respectively, were obtained. Analytic
expressions for the coefficients of these equations and their various
asymptotic forms are presented. In the case of Hopf bifurcation for low and
high frequencies, the amplitude equation reduces to a perturbed nonlinear
Schr\"odinger equation. In the high-frequency limit, structures of the type of
"dark" solitons are characteristic of the examined physical system.


title: Entropy of Reissner-Nordstrom Black Holes with Minimal Length Revisited

abstract:
  Based on the generalized uncertainty principle, we study the entropy of a
four-dimensional black hole by counting degrees of freedom near the horizon and
obtain the (finite) entropy proportional to the surface area at the horizon
without a cutoff introduced in the conventional brick-wall method.


title: Notes on Liouville Theory at c<=1

abstract:
  The continuation of the Liouville conformal field theory to c<=1 is
considered. The viability of an interpretation involving a timelike boson which
is the conformal factor for two-dimensional asymptotically de Sitter geometries
is examined. The conformal bootstrap leads to a three-point function with a
unique analytic factor which is the same as that which appears along with the
fusion coefficients in the minimal models. A corresponding non-analytic factor
produces a well-defined metric on fields only when the central charge is
restricted to those of the topological minimal models, and when the conformal
dimensions satisfy h>(c-1)/24. However, the theories considered here have a
continuous spectrum which excludes the degenerate representations appearing in
the minimal models. The c=1 theory has been investigated previously using
similar techniques, and is identical to a non-rational CFT which arises as a
limit of unitary minimal models. When coupled to unitary matter fields, the
non-unitary theories with c<=-2 produce string amplitudes which are similar to
those of the minimal string.


title: On the flight of an American Football

abstract:
  In this paper we examine the detailed theory of the American football in
flight, with spin and air resistance included. We find the theory has much in
common with the theory of a gyroscope and also rocket trajectory with a
misaligned thruster. Unfortunately most of the air resistance data, for
rocketry and ballistics, is for speeds of Mach 1 or higher, where the air
resistance increases dramatically. We shall approximate a realistic air
resistance, at the slower speeds of football flight, with a drag force
proportional to cross sectional area and either $v$ or $v^2$, depending on
speed, where $v$ is velocity of the football. We begin with a discussion of the
motion, giving as much detail as possible without the use of complex analytic
calculations. We point out the previous errors made with moments of inertia and
make the necessary corrections for more accurate results. We show that the
shape of an American football closely resembles a parabola of revolution.


title:
CANGAROO-III Search for Gamma Rays from Centaurus A and the $\omega$
  Centauri Region

abstract:
  We have observed the giant radio galaxy Centaurus A and the globular cluster
$\omega$ Centauri in the TeV energy region using the CANGAROO-III stereoscopic
system. The system has been in operation since 2004 withan array of four
Imaging Atmospheric Cherenkov Telescopes (IACT) with $\sim$100-m spacings. The
observations were carried out in March and April 2004. In total, approximately
10 hours data were obtained for each target.No statistically significant
gamma-ray signal has been found above 420 GeV over a wide angular region (a
one-degree radius from thepointing center) and we derive flux upper limits
using all of the field of view.Implications for the total energy of cosmic rays
and the density of the cold dark matter are considered.


title:
The wake of a quark moving through a strongly-coupled $\mathcal N=4$
  supersymmetric Yang-Mills plasma

abstract:
  The energy density wake produced by a heavy quark moving through a strongly
coupled N=4 supersymmetric Yang-Mills plasma is computed using gauge/string
duality.


title:
Spatial Variations of Galaxy Number Counts in the Sloan Digital Sky
  Survey. II. Test of Galactic Extinction in High Extinction Regions

abstract:
  Galactic extinction is tested using galaxy number counts at low Galactic
latitude obtained from five band photometry of the Sloan Digital Sky Survey.
The spatial variation of galaxy number counts for low extinction regions of
$E(B-V) < 0.15$ is consistent with the all-sky reddening map of Schlegel,
Finkbeiner, & Davis (1998) and the standard extinction law. For higher
extinction regions of $E(B-V) > 0.15$, however, the map of Schlegel et
al.(1998) overestimates the reddening by a factor up to 1.4, which is likely
ascribed to the departure from proportionality of reddening to infrared
emissivity of dust. This result is consistent with the analysis of Arce &
Goodman (1999) for the Taurus dark cloud complex.


title:
Kinetic investigation on extrinsic spin Hall effect induced by skew
  scattering

abstract:
  The kinetics of the extrinsic spin Hall conductivity induced by the skew
scattering is performed from the fully microscopic kinetic spin Bloch equation
approach in $(001)$ GaAs symmetric quantum well. In the steady state, the
extrinsic spin Hall current/conductivity vanishes for the linear-$\mathbf k$
dependent spin-orbit coupling and is very small for the cubic-$\mathbf k$
dependent spin-orbit coupling. The spin precession induced by the
Dresselhaus/Rashba spin-orbit coupling plays a very important role in the
vanishment of the extrinsic spin Hall conductivity in the steady state. An
in-plane spin polarization is induced by the skew scattering, with the help of
the spin-orbit coupling. This spin polarization is very different from the
current-induced spin polarization.


title:
Odd-Integer Quantum Hall Effect in Graphene: Interaction and Disorder
  Effects

abstract:
  We study the competition between the long-range Coulomb interaction, disorder
scattering, and lattice effects in the integer quantum Hall effect (IQHE) in
graphene. By direct transport calculations, both $\nu=1$ and $\nu=3$ IQHE
states are revealed in the lowest two Dirac Landau levels. However, the
critical disorder strength above which the $\nu=3$ IQHE is destroyed is much
smaller than that for the $\nu=1$ IQHE, which may explain the absence of a
$\nu=3$ plateau in recent experiments. While the excitation spectrum in the
IQHE phase is gapless within numerical finite-size analysis, we do find and
determine a mobility gap, which characterizes the energy scale of the stability
of the IQHE. Furthermore, we demonstrate that the $\nu=1$ IQHE state is a Dirac
valley and sublattice polarized Ising pseudospin ferromagnet, while the $\nu=3$
state is an $xy$ plane polarized pseudospin ferromagnet.


title: A theorem on circle configurations

abstract:
  A formula for the radii and positions of four circles in the plane for an
arbitrary linearly independent circle configuration is found. Among special
cases is the recent extended Descartes Theorem on the Descartes configuration
and an analytic solution to the Apollonian problem. The general theorem for
n-spheres is also considered.


title:
Electric-field control of tunneling magnetoresistance effect in a
  Ni/InAs/Ni quantum-dot spin valve

abstract:
  We demonstrate an electric-field control of tunneling magnetoresistance (TMR)
effect in a semiconductor quantum-dot (QD) spin-valve device. By using
ferromagnetic Ni nano-gap electrodes, we observe the Coulomb blockade
oscillations at a small bias voltage. In the vicinity of the Coulomb blockade
peak, the TMR effect is significantly modulated and even its sign is switched
by changing the gate voltage, where the sign of the TMR value changes at the
resonant condition.


title:
On the apparition of singularities of vector fields transported by
  volume preserving diffeomorphisms

abstract:
  We consider possible generation of singularities of a vector field
transported by diffeomorphisms with derivatives of uniformly bounded
determinants. A particular case of volume preserving diffeomrphism is the most
important, since it has direct applications to the incompressible, inviscid
hydrodynamics. We find relations between the directions of the vector field and
the eigenvectors of the derivative of the back-to-label map near the
singularity. We also find an invariant when we follow the motion of the
integral curves of the vector field. For the 3D Euler equations these results
have immediate implications about the directions of the vortex stretching and
the material stretching near the possible singularities. We also have similar
applications to the other inviscid, incompressible fluid equations such as the
2D quasi-geostrophic equation and the 3D magnetohydrodynamics equations.


title: A 2D model of Causal Set Quantum Gravity: The emergence of the continuum

abstract:
  Non-perturbative theories of quantum gravity inevitably include
configurations that fail to resemble physically reasonable spacetimes at large
scales. Often, these configurations are entropically dominant and pose an
obstacle to obtaining the desired classical limit. We examine this "entropy
problem" in a model of causal set quantum gravity corresponding to a
discretisation of 2D spacetimes. Using results from the theory of partial
orders we show that, in the large volume or continuum limit, its partition
function is dominated by causal sets which approximate to a region of 2D
Minkowski space. This model of causal set quantum gravity thus overcomes the
entropy problem and predicts the emergence of a physically reasonable geometry.


title: Exchange bias with Fe substitution in LaMnO_3

abstract:
  The exchange bias (EB) in LaMn_{0.7}Fe_{0.3}O_3 is observed by the negative
shift and training effect of the hysteresis loops, while the sample was cooled
in external magnetic field. The analysis of cooling field dependence of EB
gives the size of the ferromagnetic (FM) cluster ~ 25 Angstrom, where the
magnetic anisotropy of FM cluster is found two order of magnitude higher than
the FM bulk manganites. We propose that the nanoscale FM clusters are embedded
in the glassy magnetic host with EB at the FM/glassy magnetic interface.


title: $\Lambda$-adic Kolyvagin systems

abstract:
  In this paper, we study the deformations of Kolyvagin systems that are known
to exist in a wide variety of cases, by the work of B. Howard, B. Mazur, and K.
Rubin for the residual Galois representations, along the cyclotomic Iwasawa
algebra. We prove, under certain technical hypotheses, that a cyclotomic
deformation of a Kolyvagin system exists. We also briefly discuss how our
techniques could be extended to prove that one could deform Kolyvagin systems
for other deformations as well.
  We discuss several applications of this result, particularly relation of
these $\Lambda$-adic Kolyvagin systems to p-adic L-functions (in view of the
conjectures of Perrin-Riou on p-adic L-functions) and applications to main
conjectures; also applications to the study of Iwasawa theory of Rubin-Stark
units.


title: Searching Extra Dimensions in Compact Stars

abstract:
  The electro-magnetic and particle radiation detected from the direction of
Cygnus X3 raise the question of the existence of special long-lived, neutral
particles. We investigate the origin of these particles in a special approach:
the source object may contain compactified extra dimension and these particles
are messengers of this state. We describe hyperon stars in 3+1 dimension and
introduce the description of a compact stars in 3+1_c+1 dimensional space-time.


title: Giant Magnetoresistive Effect in Colloidal Magnetic Nanoparticles

abstract: This paper has been withdrawn by the authors.


title: Simple Model of Particle Detector and Arrival Time

abstract:
  We present the very simple model of a particle detector and the proposal for
the calculation of the average value of the time of arrival.


title: Conservation of energy in coherent backscattering of light

abstract:
  Although conservation of energy is fundamental in physics, its principles
seem to be violated in the field of wave propagation in turbid media by the
energy enhancement of the coherent backscattering cone. In this letter we
present experimental data which show that the energy enhancement of the cone is
balanced by an energy cutback at all scattering angles. Moreover, we give a
complete theoretical description, which is in good agreement with these data.
The additional terms needed to enforce energy conservation in this description
result from an interference effect between incident and multiply scattered
waves, which is reminiscent of the optical theorem in single scattering.


title:
Properties of the Volume Operator in Loop Quantum Gravity II: Detailed
  Presentation

abstract:
  The properties of the Volume operator in Loop Quantum Gravity, as constructed
by Ashtekar and Lewandowski, are analyzed for the first time at generic
vertices of valence greater than four. The present analysis benefits from the
general simplified formula for matrix elements of the Volume operator derived
in gr-qc/0405060, making it feasible to implement it on a computer as a matrix
which is then diagonalized numerically. The resulting eigenvalues serve as a
database to investigate the spectral properties of the volume operator.
Analytical results on the spectrum at 4-valent vertices are included. This is a
companion paper to arXiv:0706.0469, providing details of the analysis presented
there.


title:
Evolution of Dust in Primordial Supernova Remnants: Can Dust Grains
  Formed in the Ejecta Survive and be Injected into the Early Interstellar
  Medium?

abstract:
  We investigate the evolution of dust that formed at Population III supernova
(SN) explosions and its processing through the collisions with the reverse
shocks resulting from the interaction of the SN ejecta with the ambient medium.
In particular, we investigate the transport of the shocked dust within the SN
remnant (SNR), and its effect on the chemical composition, the size
distribution, and the total mass of dust surviving in SNR. We find that the
evolution of the reverse shock, and hence its effect on the processing of the
dust depends on the thickness of the envelope retained by the progenitor star.
Furthermore, the transport and survival of the dust grains depend on their
initial radius, a_{ini}, and composition: For Type II SNRs expanding into the
interstellar medium (ISM) with a density of n_{H,0}=1 cm^{-3}, small grains
with a_{ini} < ~ 0.05 micron are completely destroyed by sputtering in the
postshock flow, while grains with a_{ini}= 0.05--0.2 micron are trapped into
the dense shell behind the forward shock. Very large grains of a_{ini} > ~ 0.2
micron are ejected into the ISM without decreasing their sizes significantly.
We find that the total mass fraction of dust that is destroyed by the reverse
shock ranges from 0.2 to 1.0, depending on the energy of the explosion and the
density of the ambient ISM. The results of our calculations have significant
impact on the abundance pattern of subsequent generation of stars that form in
the dense shell of primordial SNRs.


title:
Isospin violation in $\phi, J/\psi, \psi^\prime \to \omega \pi^0$ via
  hadronic loops

abstract:
  In this work, we study the isospin-violating decay of $\phi\to \omega\pi^0$
and quantify the electromagnetic (EM) transitions and intermediate meson
exchanges as two major sources of the decay mechanisms. In the EM decays, the
present datum status allows a good constraint on the EM decay form factor in
the vector meson dominance (VMD) model, and it turns out that the EM transition
can only account for about $1/4\sim 1/3$ of the branching ratio for $\phi\to
\omega\pi^0$. The intermediate meson exchanges, $K\bar{K}(K^*)$ (intermediate
$K\bar{K}$ interaction via $K^*$ exchanges), $K\bar{K^*}(K)$ (intermediate
$K\bar{K^*}$ rescattering via kaon exchanges), and $K\bar{K^*}(K^*)$
(intermediate $K\bar{K^*}$ rescattering via $K^*$ exchanges), which evade the
naive Okubo-Zweig-Iizuka (OZI) rule, serve as another important contribution to
the isospin violations. They are evaluated with effective Lagrangians where
explicit constraints from experiment can be applied. Combining these three
contributions, we obtain results in good agreement with the experimental data.
This approach is also extended to $J/\psi(\psi^\prime)\to \omega\pi^0$, where
we find contributions from the $K\bar{K}(K^*)$, $K\bar{K^*}(K)$ and
$K\bar{K^*}(K^*)$ loops are negligibly small, and the isospin violation is
likely to be dominated by the EM transition.


title: Grand minima and maxima of solar activity: New observational constraints

abstract:
  Using a reconstruction of sunspot numbers stretching over multiple millennia,
we analyze the statistics of the occurrence of grand minima and maxima and set
new observational constraints on long-term solar and stellar dynamo models.
  We present an updated reconstruction of sunspot number over multiple
millennia, from $^{14}$C data by means of a physics-based model, using an
updated model of the evolution of the solar open magnetic flux. A list of grand
minima and maxima of solar activity is presented for the Holocene (since 9500
BC) and the statistics of both the length of individual events as well as the
waiting time between them are analyzed.
  The occurrence of grand minima/maxima is driven not by long-term cyclic
variability, but by a stochastic/chaotic process. The waiting time distribution
of the occurrence of grand minima/maxima deviates from an exponential
distribution, implying that these events tend to cluster together with long
event-free periods between the clusters. Two different types of grand minima
are observed: short (30--90 years) minima of Maunder type and long ($>$110
years) minima of Sp\"orer type, implying that a deterministic behaviour of the
dynamo during a grand minimum defines its length. The duration of grand maxima
follows an exponential distribution, suggesting that the duration of a grand
maximum is determined by a random process.
  These results set new observational constraints upon the long-term behaviour
of the solar dynamo.


title: Contact 5-manifolds with SU(2)-structure

abstract:
  We consider 5-manifolds with a contact form arising from a hypo structure,
which we call \emph{hypo-contact}. We provide conditions which imply that there
exists such a structure on an oriented hypersurface of a 6-manifold with a
half-flat SU(3)-structure. For half-flat manifolds with a Killing vector field
$X$ preserving the SU(3)-structure we study the geometry of the orbits space.
Moreover, we describe the solvable Lie algebras admitting a \emph{hypo-contact}
structure. This allows us exhibit examples of Sasakian $\eta$-Einstein
manifolds, as well as to prove that such structures give rise to new metrics
with holonomy SU(3) and to new metrics with holonomy $G_2$.


title: Quantum state transfer and time-dependent disorder in Quantum Chains

abstract:
  One of the most basic tasks required for Quantum Information Technology is
the ability to connect different components of a Quantum Computer by quantum
wires that obey the superposition principle. Since superpositions can be very
sensitive to noise this turns out to be already quite difficult. Recently, it
was suggested to use chains of permanently coupled spin-1/2 particles (quantum
chains) for this purpose. They have the advantage that no external control
along the wire is required during the transport of information, which makes it
possible to isolate the wire from sources of noise. We first give an
introduction to basic quantum state transfer and review existing advanced
schemes by other authors. We then show a new result that demonstrates the
stability of the scheme [1] against disorder that is approximately constant
during one application of the channel, but time-dependent with respect to
multiple applications.


title:
Cross-linker unbinding and self-similarity in bundled cytoskeletal
  networks

abstract:
  The macromechanical properties of purely bundled in vitro actin networks are
not only determined by the micromechanical properties of individual bundles but
also by molecular unbinding events of the actin binding protein (ABP) fascin.
Under high mechanical load the network elasticity depends on the forced
unbinding of individual ABPs in a rate dependent manner. Cross-linker unbinding
in combination with the structural self-similarity of the network enables the
introduction of a concentration/time superposition principle - broadening the
mechanically accessible frequency range over 8 orders of magnitude.


title: Nonlinear Dirac operator and quaternionic analysis

abstract:
  Properties of the Cauchy-Riemann-Fueter equation for maps between
quaternionic manifolds are studied. Spaces of solutions in case of maps from a
K3-surface to the cotangent bundle of a complex projective space are computed.
A relationship between harmonic spinors of a generalized nonlinear Dirac
operator and solutions of the Cauchy-Riemann-Fueter equation are established.


title: Superradiance and stimulated scattering in SNR 1987A

abstract:
  The rings observed around supernova remnant 1987A are emitted by a plasma
mainly made of ionized and neutral hydrogen atoms. With a density of 10 power
10 atoms per cubic metre, and at least a dimension of plasma of 0.01
light-year, the column density is 10 power 24 atoms per square metre, much more
than needed for an optically thick gas at Lyman frequencies (Case B). While, at
10000 K, the bulky gas would absorb Lyman lines fully, at 50000K it emits
superradiant lines. As superradiance de-excites the atoms strongly, nearly all
available energy is emitted in a few competing modes: Superradiance appears
only for beams which cross the largest column densities; for an observation
from Earth, these beams generate three elliptical hollow cylinders whose bases
are the observed rings; admitting that the Earth is not in a privileged
direction, these cylinders envelope ellipsoidal shells observed, for the
external rings, by photon echoes. For the equatorial ring, the brightness of
the superradiant beams is multiplied by a quasi-resonant induced scattering of
the rays emitted by the star. The de-excitation of atoms by emitted beams cools
the gas strongly, so that ionization decreases fast, the process self
accelerates. The energy of the high radiance rays from the star is strongly
scattered to the ring while the low radiance of the glow which surrounds the
star is rather amplified. The fast absorption of the radial beams produces the
radial decrease of radiance of the ring while a competition of modes produces
the pearls.


title: CMB Constraint on Radion Evolution in the Brane World Scenario

abstract:
  In many versions of brane model, the modulus field of extra dimensions, the
radion, could have cosmological evolution, which induces variation of the Higgs
vacuum expectation value, $<H>$, resulting in cosmological variation of the
electron mass $m_e$. The formation of Cosmic Microwave Background (CMB)
anisotropies is thus affected, causing changes both in the peaks positions and
amplitudes in the CMB power spectra. Using the three-year Wilkinson Microwave
Anisotropies Probe (WMAP) CMB data, with the Hubble parameter $H_0$ fixed to be
the Hubble Space Telescope (HST) result 72 km s$^{-1}$ Mpc$^{-1}$, we obtain a
constraint on $\rho$, the ratio of the value of $<H>$ at CMB recombination to
its present value, to be [0.97, 1.02].


title: Centrifugally driven electrostatic instability in extragalactic jets

abstract:
  The stability problem of the rotation induced electrostatic wave in
extragalactic jets is presented. Solving a set of equations describing dynamics
of a relativistic plasma flow of AGN jets, an expression of the instability
rate has been derived and analyzed for typical values of AGNs. The growth rate
was studied versus the wave length and the inclination angle and it has been
found that the instability process is much efficient with respect to the
accretion disk evolution, indicating high efficiency of the instability.


title:
Micro- and Macrorheological Properties of Isotropically Cross-linked
  Actin Networks

abstract:
  Cells make use of semi-flexible biopolymers such as actin or intermediate
filaments to control their local viscoelastic response by dynamically adjusting
the concentration and type of cross-linker molecules. The microstructure of the
resulting networks mainly determines their mechanical properties. It remains an
important challenge to relate structural transitions to both the molecular
properties of the cross-linking molecules and the mechanical response of the
network. This can be achieved best by well-defined in vitro model systems in
combination with microscopic techniques. Here, we show that with increasing
concentrations of the cross-linker HMM (heavy meromyosin) a transition in the
mechanical network response occurs. At low cross-linker densities the network
elasticity is dominated by the entanglement length of the polymer, while at
high HMM densities the cross-linker distance determines the elastic behavior.
Using microrheology the formation of heterogeneous networks is observed at low
cross-linker concentrations. Micro- and macrorheology both report the same
transition to a homogeneous cross-linked phase. This transition is set by a
constant average cross-linker distance. Thus, the micro- and macromechanical
properties of isotropically cross-linked in vitro actin networks are determined
by only one intrinsic network parameter.


title:
How state preparation can affect a quantum experiment: Quantum process
  tomography for open systems

abstract:
  We study the effects of preparation of input states in a quantum tomography
experiment. We show that maps arising from a quantum process tomography
experiment (called process maps) differ from the well know dynamical maps. The
difference between the two is due to the preparation procedure that is
necessary for any quantum experiment. We study two preparation procedures,
stochastic preparation and preparation by measurements. The stochastic
preparation procedure yields process maps that are linear, while the
preparations using von Neumann measurements lead to non-linear processes, and
can only be consistently described by a bi-linear process map. A new process
tomography recipe is derived for preparation by measurement for qubits. The
difference between the two methods is analyzed in terms of a quantum process
tomography experiment. A verification protocol is proposed to differentiate
between linear processes and bi-linear processes. We also emphasize the
preparation procedure will have a non-trivial effect for any quantum experiment
in which the system of interest interacts with its environment.


title:
Photonic-crystal slabs with a triangular lattice of triangular holes
  investigated using a guided-mode expansion method

abstract:
  According to a recent proposal [S. Takayama et al., Appl. Phys. Lett. 87,
061107 (2005)], the triangular lattice of triangular air holes may allow to
achieve a complete photonic band gap in two-dimensional photonic crystal slabs.
In this work we present a systematic theoretical study of this photonic lattice
in a high-index membrane, and a comparison with the conventional triangular
lattice of circular holes, by means of the guided-mode expansion method whose
detailed formulation is described here. Photonic mode dispersion below and
above the light line, gap maps, and intrinsic diffraction losses of
quasi-guided modes are calculated for the periodic lattice as well as for line-
and point-defects defined therein. The main results are summarized as follows:
(i) the triangular lattice of triangular holes does indeed have a complete
photonic band gap for the fundamental guided mode, but the useful region is
generally limited by the presence of second-order waveguide modes; (ii) the
lattice may support the usual photonic band gap for even modes (quasi-TE
polarization) and several band gaps for odd modes (quasi-TM polarization),
which could be tuned in order to achieve doubly-resonant frequency conversion
between an even mode at the fundamental frequency and an odd mode at the
second-harmonic frequency; (iii) diffraction losses of quasi-guided modes in
the triangular lattices with circular and triangular holes, and in line-defect
waveguides or point-defect cavities based on these geometries, are comparable.
The results point to the interest of the triangular lattice of triangular holes
for nonlinear optics, and show the usefulness of the guided-mode expansion
method for calculating photonic band dispersion and diffraction losses,
especially for higher-lying photonic modes.


title:
Quantum theory of exciton-photon coupling in photonic crystal slabs with
  embedded quantum wells

abstract:
  A theoretical description of radiation-matter coupling for
semiconductor-based photonic crystal slabs is presented, in which quantum wells
are embedded within the waveguide core layer. A full quantum theory is
developed, by quantizing both the electromagnetic field with a spatial
modulation of the refractive index and the exciton center of mass field in a
periodic piecewise constant potential. The second-quantized hamiltonian of the
interacting system is diagonalized with a generalized Hopfield method, thus
yielding the complex dispersion of mixed exciton-photon modes including losses.
The occurrence of both weak and strong coupling regimes is studied, and it is
concluded that the new eigenstates of the system are described by
quasi-particles called photonic crystal polaritons, which can occur in two
situations: (i) below the light line, when a resonance between exciton and
non-radiative photon levels occurs (guided polaritons), (ii) above the light
line, provided the exciton-photon coupling is larger than the intrinsic
radiative damping of the resonant photonic mode (radiative polaritons). For a
square lattice of air holes, it is found that the energy minimum of the lower
polariton branch can occur around normal incidence. The latter result has
potential implications for the realization of polariton parametric interactions
in photonic crystal slabs.


title:
Quantum key distribution over 40 dB channel loss using superconducting
  single photon detectors

abstract:
  Quantum key distribution (QKD) offers an unconditionally secure means of
communication based on the laws of quantum mechanics. Currently, a major
challenge is to achieve a QKD system with a 40 dB channel loss, which is
required if we are to realize global scale QKD networks using communication
satellites. Here we report the first QKD experiment in which secure keys were
distributed over 42 dB channel loss and 200 km of optical fibre. We employed
the differential phase shift quantum key distribution (DPS-QKD) protocol
implemented with a 10-GHz clock frequency, and superconducting single photon
detectors (SSPD) based on NbN nanowire. The SSPD offers a very low dark count
rate (a few Hz) and small timing jitter (60 ps full width at half maximum).
These characteristics allowed us to construct a 10-GHz clock QKD system and
thus distribute secure keys over channel loss of 42 dB. In addition, we
achieved a 17 kbit/s secure key rate over 105 km of optical fibre, which is two
orders of magnitude higher than the previous record, and a 12.1 bit/s secure
key rate over 200 km of optical fibre, which is the longest terrestrial QKD yet
demonstrated. The keys generated in our experiment are secure against both
general collective attacks on individual photons and a specific collective
attack on multi-photons, known as a sequential unambiguous state discrimination
(USD) attack.


title: Fermions on spontaneously generated spherical extra dimensions

abstract:
  We include fermions to the model proposed in hep-th/0606021, and obtain a
renormalizable 4-dimensional SU(N) gauge theory which spontaneously generates
fuzzy extra dimensions and behaves like Yang-Mills theory on M^4 \times S^2. We
find a truncated tower of fermionic Kaluza-Klein states transforming under the
low-energy gauge group, which is found to be either SU(n), or SU(n_1) x SU(n_2)
x U(1). The latter case implies a nontrivial U(1) flux on S^2, leading to
would-be zero modes for the bifundamental fermions. In the non-chiral case they
may pair up to acquire a mass, and the emerging picture is that of mirror
fermions. We discuss the possible implementation of a chirality constraint in 6
dimensions, which is nontrivial at the quantum level due to the fuzzy nature of
the extra dimensions.


title:
Confusing Sterile Neutrinos with Deviation from Tribimaximal Mixing at
  Neutrino Telescopes

abstract:
  We expound the impact of extra sterile species on the ultra high energy
neutrino fluxes in neutrino telescopes. We use three types of well-known flux
ratios and compare the values of these flux ratios in presence of sterile
neutrinos, with those predicted by deviation from the tribimaximal mixing
scheme. We show that in the upcoming neutrino telescopes, its easy to confuse
between the signature of sterile neutrinos with that of the deviation from
tribimaximal mixing. We also show that if the measured flux ratios acquire a
value well outside the range predicted by the standard scenario with three
active neutrinos only, it might be possible to tell the presence of extra
sterile neutrinos by observing ultra high energy neutrinos in future neutrino
telescopes.


title: Bounds for Hilbert coefficients

abstract:
  We compute the Hilbert coefficients of a graded module with pure resolution
and discuss lower and upper bounds for these coefficients for arbitrary graded
modules.


title: Integrable nonlinear equations on a circle

abstract:
  The concept of integrable boundary value problems for soliton equations on
$\mathbb{R}$ and $\mathbb{R}_+$ is extended to bounded regions enclosed by
smooth curves. Classes of integrable boundary conditions on a circle for the
Toda lattice and its reductions are found.


title: Sum-rules for electron energy-loss near-edge spectra

abstract:
  We derive four sum-rule expressions for spectra measured in electron
energy-loss near edge structure experiments. These sum-rules permit the
determination spin and orbital magnetic moments, spin-orbit interaction and
number of states, analogously to the sum rules of x-ray magnetic circular
dichroism. The derivation of the sum-rules is based on dynamical electron
diffraction theory and the properties of the mixed dynamic form-factor. The
accuracy of the sum-rules is tested by a complete evaluation of the thickness
dependent electron energy-loss spectra for iron, cobalt, and nickel crystals.
We find that the sum-rules reproduce both spin and orbital moments with very
good accuracy. Our results provide a foundation for the use of the energy loss
magnetic chiral dichroism technique as a quantitative probe of element specific
magnetic properties.


title:
Asymptotic Behavior of Total Times For Jobs That Must Start Over If a
  Failure Occurs

abstract:
  Many processes must complete in the presence of failures. Different systems
respond to task failure in different ways. The system may resume a failed task
from the failure point (or a saved checkpoint shortly before the failure
point), it may give up on the task and select a replacement task from the ready
queue, or it may restart the task. The behavior of systems under the first two
scenarios is well documented, but the third ({\em RESTART}) has resisted
detailed analysis. In this paper we derive tight asymptotic relations between
the distribution of {\em task times} without failures to the {\em total time}
when including failures, for any failure distribution. In particular, we show
that if the task time distribution has an unbounded support then the total time
distribution $H$ is always heavy-tailed. Asymptotic expressions are given for
the tail of $H$ in various scenarios. The key ingredients of the analysis are
the Cram\'er--Lundberg asymptotics for geometric sums and integral asymptotics,
that in some cases are obtained via Tauberian theorems and in some cases by
bare-hand calculations.


title:
Room temperature coexistence of large electric polarization and magnetic
  order in BiFeO3 single crystals

abstract:
  From an experimental point of view, room temperature ferroelectricity in
BiFeO3 is raising many questions. Electric measurements made a long time ago on
solid-solutions of BiFeO3 with Pb(Ti,Zr)O3 indicate that a spontaneous electric
polarization exists in BiFeO3 below the Curie temperature TC=1143K. Yet in most
reported works, the synthesised samples are too conductive at room temperature
to get a clear polarization loop in the bulk without any effects of extrinsic
physical or chemical parameters. Surprisingly, up to now there has been no
report of a P(E) (polarization versus electric field) loop at room temperature
on single crystals of BiFeO3. We describe here our procedure to synthesize
ceramics and to grow good quality sizeable single crystals by a flux method. We
demonstrate that BiFeO3 is indeed ferroelectric at room-temperature through
evidence by Piezoresponse Force Microscopy and P(E) loops. The polarization is
found to be large, around 60 microC/cm2, a value that has only been reached in
thin films. Magnetic measurements using a SQUID magnetometer and Mossbauer
spectroscopy are also presented. The latter confirms the results of NMR
measurements concerning the anisotropy of the hyperfine field attributed to the
magnetic cycloidal structure.


title: Lattice Boltzmann Approach to High-Speed Compressible Flows

abstract:
  We present an improved lattice Boltzmann model for high-speed compressible
flows. The model is composed of a discrete-velocity model by Kataoka and
Tsutahara [Phys. Rev. E \textbf{69}, 056702 (2004)] and an appropriate
finite-difference scheme combined with an additional dissipation term. With the
dissipation term parameters in the model can be flexibly chosen so that the von
Neumann stability condition is satisfied. The influence of the various model
parameters on the numerical stability is analyzed and some reference values of
parameter are suggested. The new scheme works for both subsonic and supersonic
flows with a Mach number up to 30 (or higher), which is validated by well-known
benchmark tests. Simulations on Riemann problems with very high ratios
($1000:1$) of pressure and density also show good accuracy and stability.
Successful recovering of regular and double Mach shock reflections shows the
potential application of the lattice Boltzmann model to fluid systems where
non-equilibrium processes are intrinsic. The new scheme for stability can be
easily extended to other lattice Boltzmann models.


title:
Evolutionary dynamics of the most populated genotype on rugged fitness
  landscapes

abstract:
  We consider an asexual population evolving on rugged fitness landscapes which
are defined on the multi-dimensional genotypic space and have many local
optima. We track the most populated genotype as it changes when the population
jumps from a fitness peak to a better one during the process of adaptation.
This is done using the dynamics of the shell model which is a simplified
version of the quasispecies model for infinite populations and standard
Wright-Fisher dynamics for large finite populations. We show that the
population fraction of a genotype obtained within the quasispecies model and
the shell model match for fit genotypes and at short times, but the dynamics of
the two models are identical for questions related to the most populated
genotype. We calculate exactly several properties of the jumps in infinite
populations some of which were obtained numerically in previous works. We also
present our preliminary simulation results for finite populations. In
particular, we measure the jump distribution in time and find that it decays as
$t^{-2}$ as in the quasispecies problem.


title: Fabry-Perot Interferometry and Dynamics of Spiral Galaxies

abstract:
  We present two-dimensional Febry-Perot observations of emission-line
distribution and kinematics in nearly spiral galaxies. We have developed and
demonstrated the utility of a number of analysis tools which have general
applicability, but which we have, so far, applied to only one galaxy (M 74,
Fathi et al. 2007). In this galaxy, we have found kinematic signatures of
radial motions caused by an m=2 perturbation. Such a perturbation may well be
responsible for the inflow of material forming the nuclear ring and the inner
rapidly rotating disc-like structure. The latter, in turn, could help build a
pseudo-bulge. In the second paper in this series, we will apply the kinematic
analysis tools to a sample of 9 late-type spiral galaxies observed with the
FaNTOmM Fabry-Perot spectrometer at the Canada-France-Hawaii telescope.


title:
Automorphisms fixing every normal subgroup of a nilpotent-by-abelian
  group

abstract:
  Among other things, we prove that the group of automorphisms fixing every
normal subgroup of a nilpotent-by-abelian group is nilpotent-by-metabelian. In
particular, the group of automorphisms fixing every normal subgroup of a
metabelian group is soluble of derived length at most 3. An example shows that
this bound cannot be improved.


title:
Comments on Solutions for Nonsingular Currents in Open String Field
  Theories

abstract:
  We investigate analytic solutions to Witten's bosonic string field theory and
Berkovits' WZW-type superstring field theory. We construct solutions with
parameters out of simpler ones, using a commutative monoid that includes the
family of wedge states. Our solutions are generalizations of solutions for
marginal deformations by nonsingular currents, and can also reproduce Schnabl's
tachyon vacuum solution in bosonic string field theory. This implies that such
known solutions are generated from simple solutions which are based on the
identity state. We also discuss gauge transformations and induced field
redefinitions for our solutions in both bosonic and super string field theory.


title: Curvature Inspired Cosmological Scenario

abstract:
  Using modified gravity with non-linear terms of curvature, $R^2$ and $R^{(r
+2)}$ (with $r$ being the positive real number and $R$ being the scalar
curvature), cosmological scenario,beginning at the Planck scale, is obtained.
Here, a unified picture of cosmology is obtained from $f(R)-$ gravity. In this
scenario, universe begins with power-law inflation, followed by deceleration
and acceleration in the late universe as well as possible collapse of the
universe in future. It is different from $f(R)-$ dark energy models with
non-linear curvature terms assumed as dark energy. Here, dark energy terms are
induced by linear as well as non-linear terms of curvature in Friedmann
equation being derived from modified gravity.It is also interesting to see
that, in this model, dark radiation and dark matter terms emerge spontaneously
from the gravitational sector. It is found that dark energy, obtained here,
behaves as quintessence in the early universe and phantom in the late universe.
Moreover, analogous to brane-tension in brane-gravity inspired Friedmann
equation, a tension term $\lambda$ arises here being called as cosmic tension.
It is found that, in the late universe, Friedmann equation (obtained here)
contains a term $- \rho^2/2\lambda$ ($\rho$ being the phantom energy density)
analogous to a similar term in Friedmann equation with loop quantum effects, if
$\lambda > 0$ and brane-gravity correction when $\lambda < 0.$


title: The shear viscosity of the non-commutative plasma

abstract:
  We compute the shear viscosity of the non-commutative N=4 super Yang-Mills
quantum field theory at strong coupling using the dual supergravity background.
Special interest derives from the fact that the background presents an
intrinsic anisotropy in space through the distinction of commutative and
non-commutative directions. Despite this anisotropy the analysis exhibits the
ubiquitous result \eta/s = 1/4\pi for two different shear channels. In order to
derive this result, we show that the boundary energy momentum tensor must
couple to the open string metric. As a byproduct we compute the renormalised
holographic energy momentum tensor and show that it coincides with one in the
commutative theory.


title: Scale-dependent Galaxy Bias

abstract:
  We present a simple heuristic model to demonstrate how feedback related to
the galaxy formation process can result in a scale-dependent bias of mass
versus light, even on very large scales. The model invokes the idea that
galaxies form initially in locations determined by the local density field, but
the subsequent formation of galaxies is also influenced by the presence of
nearby galaxies that have already formed. The form of bias that results
possesses some features that are usually described in terms of stochastic
effects, but our model is entirely deterministic once the density field is
specified. Features in the large-scale galaxy power spectrum (such as wiggles
that might in an extreme case mimic the effect of baryons on the primordial
transfer function) could, at least in principle, arise from spatial modulations
of the galaxy formation process that arise naturally in our model. We also show
how this fully deterministic model gives rise to apparently stochasticity in
the galaxy distribution.


title: Regularity of harmonic functions for anisotropic fractional Laplacian

abstract:
  We prove that bounded harmonic functions of anisotropic fractional Laplacians
are H\"older continuous under mild regularity assumptions on the corresponding
L\'evy measure. Under some stronger assumptions the Green function, Poisson
kernel and the harmonic functions are even differentiable of order up to three.


title: Engineered quantum tunnelling in extended periodic potentials

abstract:
  Quantum tunnelling from a tilted, but otherwise periodic potential is
studied. Our theoretical and experimental results show that, by controlling the
system's parameters, we can engineer the escape rate of a Bose-Einstein
condensate to an exceptional degree. Possible applications of this atom-optics
realization of the open Wannier-Stark system are discussed.


title: Analytic wave front set for solutions to Schroedinger equation

abstract:
  This paper is a continuation of a previous paper by the same authors, where
an analytic smoothing effect was proved for long-range type perturbations of
the Laplacian $H_0$ on $\re^n$. In this paper, we consider short-range type
perturbations $H$ of the Laplacian on $\re^n$, and we characterize the analytic
wave front set of the solution to the Schr\"odinger equation:
  $e^{-itH}f$, in terms of that of the free solution: $e^{-itH_0}f$, for $t<0$
in the forward nontrapping region. The same result holds for $t>0$ in the
backward nontrapping region. This result is an analytic analogue of results by
Hassel and Wunsch and Nakamura.


title: Zero modes on cosmic string loops

abstract:
  We study the spectrum of fermionic modes on cosmic string loops. We find no
fermionic zero modes nor massive bound states - this implies that vortons
stabilized by fermionic currents do not exist. We have also studied
kink-(anti)kink and vortex-(anti)vortex systems and find that all systems that
have vanishing net topological charge do not support fermionic bound modes.


title: On the kernel of the norm in some unramified number fields extensions

abstract:
  We determine the -1 Tate cohomology group of the units for principal abelian
extensions of type (p^a, p^b) of a number field.


title:
Immune System -- Tumor Efficiency Rate as a new Oncological Index for
  Radiotherapy Treatment Optimization

abstract:
  A dynamical system model for tumor -- immune system interaction together with
a method to mimic radiation therapy are proposed. A large population of virtual
patients is simulated following an ideal radiation treatment. A characteristic
parameter, the Immune System -- Tumor Efficiency Rate (ISTER), is introduced.
ISTER dependence of treatment success and other features is studied.
Statistical results allow us to give a patient classification scheme.
Radiotherapy treatment biological effective dose (BED) is thus optimized based
on the patient physical condition, following the ALARA (As Low As Reasonably
Achievable) criterion.


title: Critical Behaviour of Irreversible Reaction Systems

abstract:
  An introductory review on the critical behaviour of some irreversible
reaction systems is given. The study of these systems has attracted great
attention during the last decades due to, on the one hand, the rich and complex
underlying physics, and on the other hand, their relevance for numerous
technological applications in heterogeneous catalysis, corrosion and coating,
development of microelectronic devices, etc. The review is focuses on recent
advances in the understanding of irreversible phase transitions (IPT's)
providing a survey of the theoretical development of the field during the last
decade, as well as a detailed discussion of relevant numerical simulations. The
Langevin formulation for the treatment of second-order IPT's is discussed.
Different Monte Carlo approaches are also presented in detail and the
finite-size scaling analysis of second-order IPT's is described. Special
attention is devoted to the description of recent progress in the study of
first-order IPT's observed upon catalytic oxidation of carbon monoxide and the
reduction of nitrogen monoxide, using lattice gas reaction models. Only brief
comments are given on other reactions such as the oxidation of hydrogen,
ammonia synthesis, etc. Also, a discussion of relevant experiments is presented
and measurement are compared with the numerical results. Furthermore, promising
areas for further research and open questions are also addressed.


title: Magnetic field induced 3D to 1D crossover in Sr0:9La0:1CuO2

abstract:
  The effect of the magnetic field on the critical behavior of Sr0:9La0:1CuO2
is explored in terms of reversible magnetization data. As the correlation
length transverse to the magnetic field Hi,applied along the i-axis, cannot
grow beyond the limiting magnetic length LHi, related to the average distance
between vortex lines, one expects a magnetic field induced finite size effect.
Invoking the scaling theory of critical phenomena we provide clear evidence for
this effect. It implies that in type II superconductors there is a 3D to 1D
crossover line Hpi(T). Consequently, below Tc and above Hpi(T) uperconductivity
is confined to cylinders with diameter LHi(1D). Accordingly, there is no
continuous phase transition in the (H,T)-plane along the Hc2-lines as predicted
by the mean-field treatment.


title: Stability of Euclidean space under Ricci flow

abstract:
  We study the Ricci flow for initial metrics which are C^0 small perturbations
of the Euclidean metric on R^n. In the case that this metric is asymptotically
Euclidean, we show that a Ricci harmonic map heat flow exists for all times,
and converges uniformly to the Euclidean metric as time approaches infinity. In
proving this stability result, we introduce a monotone integral quantity which
measures the deviation of the evolving metric from the Euclidean metric. We
also investigate the convergence of the diffeomorphisms relating Ricci harmonic
map heat flow to Ricci flow.


title: Analytical Model of the Time Developing Turbulent Boundary Layer

abstract:
  We present an analytical model for the time-developing turbulent boundary
layer (TD-TBL) over a flat plate. The model provides explicit formulae for the
temporal behavior of the wall-shear stress and both the temporal and spatial
distributions of the mean streamwise velocity, the turbulence kinetic energy
and Reynolds shear stress. The resulting profiles are in good agreement with
the DNS results of spatially-developing turbulent boundary layers at momentum
thickness Reynolds number equal to 1430 and 2900. Our analytical model is, to
the best of our knowledge, the first of its kind for TD-TBL.


title: A variational method based on weighted graph states

abstract:
  In a recent article [Phys. Rev. Lett. 97 (2006), 107206], we have presented a
class of states which is suitable as a variational set to find ground states in
spin systems of arbitrary spatial dimension and with long-range entanglement.
Here, we continue the exposition of our technique, extend from spin 1/2 to
higher spins and use the boson Hubbard model as a non-trivial example to
demonstrate our scheme.


title:
Divergence of the axial current and fermion density in Gross-Neveu
  models

abstract:
  The divergence of the axial current is used to relate the spatial derivative
of the fermion density to the bare fermion mass and scalar/pseudoscalar
condensates in 1+1 dimensional Gross-Neveu models. This serves as a novel test
of known results, to explain simple features of the continuous chiral model and
to resolve a conflict concerning the assignment of baryon number to certain
multi-fermion bound states.


title: Two-mode single-atom laser as a source of entangled light

abstract:
  A two-mode single-atom laser is considered, with the aim of generating
entanglement in macroscopic light. Two transitions in the four-level gain
medium atom independently interact with the two cavity modes, while two other
transitions are driven by control laser fields. Atomic relaxation as well as
cavity losses are taken into account. We show that this system is a source of
macroscopic entangled light over a wide range of control parameters and initial
states of the cavity field.


title: Basic-deformed thermostatistics

abstract:
  Starting from the basic-exponential, a q-deformed version of the exponential
function established in the framework of the basic-hypergeometric series, we
present a possible formulation of a generalized statistical mechanics. In a
q-nonuniform lattice we introduce the basic-entropy related to the
basic-exponential by means of a q-variational principle. Remarkably, this
distribution exhibits a natural cut-off in the energy spectrum. This fact,
already encountered in other formulations of generalized statistical mechanics,
is expected to be relevant to the applications of the theory to those systems
governed by long-range interactions. By employing the q-calculus, it is shown
that the standard thermodynamic functional relationships are preserved,
mimicking, in this way, the mathematical structure of the ordinary
thermostatistics which is recovered in the q=1 limit.

categories: cond-mat.stat-mech math-ph math.MP math.QA nucl-th


title: Watermark Embedding and Detection

abstract:
  The embedder and the detector (or decoder) are the two most important
components of the digital watermarking systems. Thus in this work, we discuss
how to design a better embedder and detector (or decoder). I first give a
summary of the prospective applications of watermarking technology and major
watermarking schemes in the literature. My review on the literature closely
centers upon how the side information is exploited at both embedders and
detectors. In Chapter 3, I explore the optimum detector or decoder according to
a particular probability distribution of the host signals. We found that the
performance of both multiplicative and additive spread spectrum schemes depends
on the shape parameter of the host signals. For spread spectrum schemes, the
performance of the detector or the decoder is reduced by the host interference.
Thus I present a new host-interference rejection technique for the
multiplicative spread spectrum schemes. Its embedding rule is tailored to the
optimum detection or decoding rule. Though the host interference rejection
schemes enjoy a big performance gain over the traditional spread spectrum
schemes, their drawbacks that it is difficult for them to be implemented with
the perceptual analysis to achieve the maximum allowable embedding level
discourage their use in real scenarios. Thus, in the last chapters of this
work, I introduce a double-sided technique to tackle this drawback. It differs
from the host interference rejection schemes in that it utilizes but does not
reject the host interference at its embedder. The perceptual analysis can be
easily implemented in our scheme to achieve the maximum allowable level of
embedding strength.


title: Nature of the bound states of molecular hydrogen in carbon nanohorns

abstract:
  The effects of confining molecular hydrogen within carbon nanohorns are
studied via high-resolution quasielastic and inelastic neutron spectroscopies.
Both sets of data are remarkably different from those obtained in bulk samples
in the liquid and crystalline states. At temperatures where bulk hydrogen is
liquid, the spectra of the confined sample show an elastic component indicating
a significant proportion of immobile molecules as well as distinctly narrower
quasielastic line widths and a strong distortion of the line shape of the para
- ortho rotational transition. The results show that hydrogen interacts far
more strongly with such carbonous structures than it does to carbon nanotubes,
suggesting that nanohorns and related nanostructures may offer significantly
better prospects as lightweight media for hydrogen storage applications.


title:
Finite strain viscoplasticity with nonlinear kinematic hardening:
  phenomenological modeling and time integration

abstract:
  This article deals with a viscoplastic material model of overstress type. The
model is based on a multiplicative decomposition of the deformation gradient
into elastic and inelastic part. An additional multiplicative decomposition of
inelastic part is used to describe a nonlinear kinematic hardening of
Armstrong-Frederick type.
  Two implicit time-stepping methods are adopted for numerical integration of
evolution equations, such that the plastic incompressibility constraint is
exactly satisfied. The first method is based on the tensor exponential. The
second method is a modified Euler-Backward method. Special numerical tests show
that both approaches yield similar results even for finite inelastic
increments.
  The basic features of the material response, predicted by the material model,
are illustrated with a series of numerical simulations.


title: Anonymity in the Wild: Mixes on unstructured networks

abstract:
  As decentralized computing scenarios get ever more popular, unstructured
topologies are natural candidates to consider running mix networks upon. We
consider mix network topologies where mixes are placed on the nodes of an
unstructured network, such as social networks and scale-free random networks.
We explore the efficiency and traffic analysis resistance properties of mix
networks based on unstructured topologies as opposed to theoretically optimal
structured topologies, under high latency conditions. We consider a mix of
directed and undirected network models, as well as one real world case study --
the LiveJournal friendship network topology. Our analysis indicates that
mix-networks based on scale-free and small-world topologies have, firstly,
mix-route lengths that are roughly comparable to those in expander graphs;
second, that compromise of the most central nodes has little effect on
anonymization properties, and third, batch sizes required for warding off
intersection attacks need to be an order of magnitude higher in unstructured
networks in comparison with expander graph topologies.


title:
Abstract numeration systems on bounded languages and multiplication by a
  constant

abstract:
  A set of integers is $S$-recognizable in an abstract numeration system $S$ if
the language made up of the representations of its elements is accepted by a
finite automaton. For abstract numeration systems built over bounded languages
with at least three letters, we show that multiplication by an integer
$\lambda\ge2$ does not preserve $S$-recognizability, meaning that there always
exists a $S$-recognizable set $X$ such that $\lambda X$ is not
$S$-recognizable. The main tool is a bijection between the representation of an
integer over a bounded language and its decomposition as a sum of binomial
coefficients with certain properties, the so-called combinatorial numeration
system.


title: The Higgs boson from an extended symmetry

abstract:
  The variety of ideas put forward in the context of a "composite" picture for
the Higgs boson calls for a simple and effective description of the related
phenomenology. Such a description is given here by means of a "minimal" model
and is explicitly applied to the example of a Higgs-top sector from an SO(5)
symmetry. We discuss the spectrum, the ElectroWeak Precision Tests, B-physics
and naturalness. We show the difficulty to comply with the different
constraints. The extended gauge sector relative to the standard SU(2)xU(1), if
there is any, has little or no impact on these considerations. We also discuss
the relation of the "minimal" model with its "little Higgs" or "holographic"
extensions based on the same symmetry.


title: Numerical Clifford Analysis for Nonlinear Schrodinger Problem

abstract:
  The aim of this work is to study the numerical solution of the nonlinear
Schrodinger problem using a combination between Witt basis and finite
difference approximations. We construct a discrete fundamental solution for the
non-stationary Schrodinger operator and we show the convergence of the
numerical scheme. Numerical examples are given at the end of the paper.


title: Shock-triggered formation of magnetically-dominated clouds

abstract:
  To understand the formation of a magnetically dominated molecular cloud out
of an atomic cloud, we follow the dynamical evolution of the cloud with a
time-dependent axisymmetric magnetohydrodynamic code. A thermally stable warm
atomic cloud is initially in static equilibrium with the surrounding hot
ionised gas. A shock propagating through the hot medium interacts with the
cloud. As a fast-mode shock propagates through the cloud, the gas behind it
becomes thermally unstable. The $\beta$ value of the gas also becomes much
smaller than the initial value of order unity. These conditions are ideal for
magnetohydrodynamic waves to produce high-density clumps embedded in a rarefied
warm medium. A slow-mode shock follows the fast-mode shock. Behind this shock a
dense shell forms, which subsequently fragments. This is a primary region for
the formation of massive stars. Our simulations show that only weak and
moderate-strength shocks can form cold clouds which have properties typical of
giant molecular clouds.


title:
Carleson Measures for the Drury-Arveson Hardy space and other
  Besov-Sobolev spaces on Complex Balls

abstract:
  We characterize the Carleson measures for the Drury-Arveson Hardy space and
other Hilbert spaces of analytic functions of several complex variables. This
provides sharp estimates for Drury's generalization of Von Neumann's
inequality. The characterization is in terms of a geometric condition, the
"split tree condition", which reflects the nonisotropic geometry underlying the
Drury-Arveson Hardy space.


title: Superstatistics of Brownian motion: A comparative study

abstract:
  The dynamics of temperature fluctuations of a gas of Brownian particles in
local equilibrium with a nonequilibrium heat bath, are described using an
approach consistent with Boltzmann-Gibbs statistics (BG). We use mesoscopic
nonequilibrium thermodynamics (MNET) to derive a Fokker-Planck equation for the
probability distribution in phase space including the local intensive variables
fluctuations. We contract the description to obtain an effective probability
distribution (EPD) from which the mass density, van Hove's function and the
dynamic structure factor of the system are obtained. The main result is to show
that in the long time limit the EPD exhibits a similar behavior as the
superstatistics distribution of nonextensive statistical mechanics (NESM),
therfore implying that the coarse-graining procedure is responsible for the so
called nonextensive effects.


title:
Measurement of neutrino velocity with the MINOS detectors and NuMI
  neutrino beam

abstract:
  The velocity of a ~3 GeV neutrino beam is measured by comparing detection
times at the Near and Far detectors of the MINOS experiment, separated by 734
km. A total of 473 Far Detector neutrino events was used to measure (v-c)/c =
5.1 +/- 2.9 x 10^-5 (at 68% C.L.). By correlating the measured energies of 258
charged-current neutrino events to their arrival times at the Far Detector, a
limit is imposed on the neutrino mass of m_nu < 50 MeV/c^2 (99% C.L.).


title: Isoconfigurational thermostat

abstract:
  A holonomic constraint is used to enforce a constant instantaneous
configurational temperature on an equilibrium system. Three sets of equations
of motion are obtained, differing according to the way in which the holonomic
constraint is introduced and the phase space distribution function that is
preserved by the dynamics. Firstly, Gauss' principle of least constraint is
used, and it is shown that it does not preserve the canonical distribution.
Secondly, a modified Hamiltonian is used to find a dynamics that provides a
restricted microcanonical distribution. Lastly, we provide equations that are
specifically designed to both satisfy the temperature constraint and produce a
restricted canonical ensemble.


title: Multiband superconductivity and penetration depth in PrOs4Sb12

abstract:
  The effective superconducting penetration depth measured in the vortex state
of PrOs4Sb12 using transverse-field muon spin rotation (TF-muSR) exhibits an
activated temperature dependence at low temperatures, consistent with a nonzero
gap for quasiparticle excitations. In contrast, Meissner-state radiofrequency
(rf) inductive measurements of the penetration depth yield a T^2 temperature
dependence, suggestive of point nodes in the gap. A scenario based on the
recent discovery of extreme two-band superconductivity in PrOs4Sb12 is proposed
to resolve this difference. In this picture a large difference between large-
and small-gap coherence lengths renders the field distribution in the vortex
state controlled mainly by supercurrents from a fully-gapped large-gap band. In
zero field all bands contribute, yielding a stronger temperature dependence to
the rf inductive measurements.


title:
What Makes a System Complex? an Approach to Self-Organization and
  Emergence

abstract:
  The fast changing reality in technical and natural domains perceived by
always more accurate observations has drawn attention on new and very broad
class of systems with specific behaviour represented under the common wording
complexity. From elementary system graph representation with components as
nodes and interactions as vertices, systems are shown to belong to only three
states : simple, complicated, and complex, the main properties of which are
discussed. The first two states have been studied at length over past
centuries, and last one finds its origin in the elementary fact that when
system performance is pushed up, there exists a threshold above which
interaction between components overtake outside interaction. Then system
self-organizes and filters corresponding outer action, making it more robust to
outer effect, with emergence of new behaviour not predictable from only
components study. Examples in Physics and Biology are given. Three main classes
of complexity behaviour are distinguished corresponding to different grades of
difficulty to handle their dynamics. The interest of using complex state
properties in man-made systems is stressed. Important issues concentrating on
the difficult balance between relative system isolation when becoming complex
and required delegation of corresponding new capability from (outside) operator
are discussed. This implies giving the system some intelligence in an adequate
frame between new augmented system state and supervising operator, with
consequences on canonical system triplet {effector-sensor-controller} to be
reorganized in this new setting. Moreover, entering complexity state opens the
possibility for function to feedback onto structure, ie to mimic at technical
level the invention of Nature over Her very long history.


title:
Pair Production of Doubly-Charged Scalars: Neutrino Mass Constraints and
  Signals at the LHC

abstract:
  We study the pair production of doubly charged Higgs bosons at the Large
Hadron Collider (LHC), assuming the doubly charged Higgs to be part of an
SU(2)_L triplet which generates Majorana masses for left-handed neutrinos. Such
pair-production has the advantage that it is not constrained by the triplet
vacuum expectation value, which tends to make the single production rate rather
small. We point out that, in addition to the Drell-Yan (DY) production
mechanism, two-photon processes also contribute to H++H++ production at a level
comparable to the QCD corrections to the DY channel. Decays of the doubly
charged Higgs into both the l+l+ and W+W+ modes are studied in detail to
optimize the signal observation over the backgrounds. Doubly charged scalars
should be observable at the LHC with 300 fb^-1 integrated luminosity in the ll
channel upto the mass range of 1 TeV even with a branching fraction of about 60
%, and in the WW channel upto a mass of 700 GeV. Such a doubly charged Higgs,
if it is a member of a triplet generating neutrino masses,cannot be long-lived
on the scale of collider detectors although it might lead to a displaced
secondary vertex during its decay if it is lighter than about 250 GeV.


title: Spiky Strings, Giant Magnons and beta-deformations

abstract:
  We study rigid string solutions rotating on the S^3 subspace of the
beta-deformed AdS_5xS^5 background found by Lunin and Maldacena. For particular
values of the parameters of the solutions we find the known giant magnon and
single spike strings. We present a single spike string solution on the deformed
S^3 and find how the deformation affects the dispersion relation. The possible
relation of this string solution to spin chains and the connection of the
solutions on the undeformed S^3 to the sine-Gordon model are briefly discussed.


title: Conservation Laws and Potential Symmetries of Linear Parabolic Equations

abstract:
  We carry out an extensive investigation of conservation laws and potential
symmetries for the class of linear (1+1)-dimensional second-order parabolic
equations. The group classification of this class is revised by employing
admissible transformations, the notion of normalized classes of differential
equations and the adjoint variational principle. All possible potential
conservation laws are described completely. They are in fact exhausted by local
conservation laws. For any equation from the above class the characteristic
space of local conservation laws is isomorphic to the solution set of the
adjoint equation. Effective criteria for the existence of potential symmetries
are proposed. Their proofs involve a rather intricate interplay between
different representations of potential systems, the notion of a potential
equation associated with a tuple of characteristics, prolongation of the
equivalence group to the whole potential frame and application of multiple dual
Darboux transformations. Based on the tools developed, a preliminary analysis
of generalized potential symmetries is carried out and then applied to
substantiate our construction of potential systems. The simplest potential
symmetries of the linear heat equation, which are associated with single
conservation laws, are classified with respect to its point symmetry group.
Equations possessing infinite series of potential symmetry algebras are studied
in detail.


title:
Pseudogap and Mott Transition Studied by Cellular Dynamical Mean Field
  Theory

abstract:
  We study metal-insulator transitions between Mott insulators and metals. The
transition mechanism completely different from the original dynamical mean
field theory (DMFT) emerges from a cluster extension of it. A consistent
picture suggests that the quasiparticle weight $Z$ remains nonzero through
metals and suddenly jumps to zero at the transition, while the gap opens
continuously in the insulators. This is in contrast with the original DMFT,
where $Z$ continuously vanishes but the gap opens discontinuously. The present
results arising from electron differentiation in momentum space agree with
recent puzzling bulk-sensitive experiments on CaVO$_3$ and SrVO$_3$.


title:
Damage spreading in 2-dimensional isotropic and anisotropic Bak-Sneppen
  models

abstract:
  We implement the damage spreading technique on 2-dimensional isotropic and
anisotropic Bak-Sneppen models. Our extensive numerical simulations show that
there exists a power-law sensitivity to the initial conditions at the
statistically stationary state (self-organized critical state). Corresponding
growth exponent $\alpha$ for the Hamming distance and the dynamical exponent
$z$ are calculated. These values allow us to observe a clear data collapse of
the finite size scaling for both versions of the Bak-Sneppen model. Moreover,
it is shown that the growth exponent of the distance in the isotropic and
anisotropic Bak-Sneppen models is strongly affected by the choice of the
transient time.


title: Strings in Yang-Mills-Higgs theory coupled to gravity

abstract:
  Non-Abelian strings for an Einstein-Yang-Mills-Higgs theory are explicitly
constructed. We consider N_f Higgs fields in the fundamental representation of
the U(1)xSU(N_c) gauge group in order to have a color-flavor SU(N_c) group
remaining unbroken. Choosing a suitable ansatz for the metric, Bogomol'nyi-like
first order equations are found and rotationally symmetric solutions are
proposed. In the N_f = N_c case, solutions are local strings and are shown to
be truly non-Abelian by parameterizing them in terms of orientational
collective coordinates. When N_f > N_c, the solutions correspond to semilocal
strings which, beside the orientational degrees of freedom, acquire additional
collective coordinates parameterizing their transverse size. The low-energy
effective theories for the correspondent moduli are found, showing that all
zero modes are normalizable in presence of gravity, even in the semilocal case.


title:
Non lin\'earit\'e des fonctions bool\'eennes donn\'ees par des traces de
  polyn\^omes de degr\'e binaire 3

abstract:
  Nous \'etudions la non lin\'earit\'e des fonctions d\'efinies sur F_{2^m}
o\`u $m$ est un entier impair, associ\'ees aux polyn\^omes de degr\'e 7 ou \`a
des polyn\^omes plus g\'en\'eraux.
  -----
  We study the nonlinearity of the functions defined on F_{2^m} where $m$ is an
odd integer, associated to the polynomials of degree 7 or more general
polynomials.


title: Representations of Graded Multi-Loop Lie Algebras

abstract:
  Let g_A (respectively, g_A(\mu)) be the graded multi-loop Lie algebra
(respectively graded twisted multi-loop Lie algebra)" associated with the
simple finite dimensional Lie algebra g over the complex field C. In this
paper, we prove that irreducible integrable g_A(\mu)-modules with finite
dimensional weight spaces are either highest weight modules or their duals and
classify the isomorphism classes of irreducible integrable g_A-modules and
g_A(\mu)-modules with finite dimensional weight spaces.


title: The dyon charge in noncommutative gauge theories

abstract:
  We present an explicit classical dyon solution for the noncommutative version
of the Yang-Mills-Higgs model (in the Prasad-Sommerfield limit) with a tehta
term. We show that the relation between classical electric and magnetic charges
also holds in noncommutative space. Extending the Noether approach to the case
of a noncommutative gauge theory, we analyze the effect of CP violation at the
quantum level, induced both by the theta term and by noncommutativity and we
prove that the Witten effect formula for the dyon charge remains the same as in
ordinary space.


title: Universal properties of population dynamics with fluctuating resources

abstract:
  Starting from the well-known field theory for directed percolation, we
describe an evolving population, near extinction, in an environment with its
own nontrivial spatio-temporal dynamics. Here, we consider the special case
where the environment follows a simple relaxational (Model A) dynamics. Two new
operators emerge, with upper critical dimension of four, which couple the two
theories in a nontrivial way. While the Wilson-Fisher fixed point remains
completely unaffected, a mismatch of time scales destabilizes the usual DP
fixed point, suggesting a crossover to a first order transition from the active
(surviving) to the inactive (extinct) state.


title: Density-metric unimodular gravity:vacuum spherical symmetry

abstract:
  We analyze an alternative theory of gravity characterized by metrics that are
tensor density of rank(0,2)and weight-1/2.The metric compatibility condition is
supposed to hold. The simplest expression for the action of gravitational field
is used.Taking the metric and trace of connections as dynamical variables,the
field equations in the absence of matter and other kinds of sources are
derived.The solutions of these equations are obtained for the case of vacuum
static spherical symmetric spacetime.The null geodesics and advance of
perihelion of ellipes are discussed.We confirm a subclass of solutions is
regular for r>0 and there is no event horizon while it is singular at r=0.


title: Some remarks on the dynamical systems approach to fourth order gravity

abstract:
  Building on earlier work, we discuss a general framework for exploring the
cosmological dynamics of Higher Order Theories of Gravity. We show that once
the theory of gravity has been specified, the cosmological equations can be
written as a first-order autonomous system and we give several examples which
illustrate the utility of our method. We also discuss a number of results which
have appeared recently in the literature.


title:
Fractal analysis for sets of non-differentiability of Minkowski's
  question mark function

abstract:
  In this paper we study various fractal geometric aspects of the Minkowski
question mark function $Q.$ We show that the unit interval can be written as
the union of the three sets $\Lambda_{0}:=\{x:Q'(x)=0\}$,
$\Lambda_{\infty}:=\{x:Q'(x)=\infty\}$, and $\Lambda_{\sim}:=\{x:Q'(x)$ does
not exist and $Q'(x)\not=\infty\}.$ The main result is that the Hausdorff
dimensions of these sets are related in the following way.
$\dim_{H}(\nu_{F})<\dim_{H}(\Lambda_{\sim})= \dim_{H} (\Lambda_{\infty}) =
\dim_{H} (\mathcal{L}(h_{\mathrm{top}}))<\dim_{H}(\Lambda_{0})=1.$
  Here, $\mathcal{L}(h_{\mathrm{top}})$ refers to the level set of the
  Stern-Brocot multifractal decomposition at the topological entropy
  $h_{\mathrm{top}}=\log2$ of the Farey map $F,$ and $\dim_{H}(\nu_{F})$
denotes the Hausdorff dimension of the measure of maximal entropy of the
dynamical system associated with $F.$ The proofs rely partially on the
multifractal formalism for Stern-Brocot intervals and give non-trivial
applications of this formalism.


title:
Neutrino oscillations in a variable-density medium and $\nu-$ bursts due
  to the gravitational collapse of stars

abstract:
  Under certain conditions, the propagation of a beam of oscillating neutrinos
in a variable-density medium takes the form of an almost complete
transformation of the initial type of neutrino into another type. The depth of
oscillations is then negligible. The transformation can occur in the cores and
envelopes of collapsing stars.


title: Braided enveloping algebras associated to quantum parabolic subalgebras

abstract:
  Associated to each subset $J$ of the nodes $I$ of a Dynkin diagram is a
triangular decomposition of the corresponding Lie algebra $\mathfrak{g}$ into
three subalgebras $\widetilde{\mathfrak{g}_{J}}$ (generated by $e_{j}$, $f_{j}$
for $j\in J$ and $h_{i}$ for $i\in I$), $\mathfrak{n}^{-}_{D}$ (generated by
$f_{d}$, $d\in D=I\setminus J$) and its dual $\mathfrak{n}_{D}^{+}$.
  We demonstrate a quantum counterpart, generalising work of Majid and Rosso,
by exhibiting analogous triangular decompositions of $U_{q}(\mathfrak{g})$ and
identifying a graded braided Hopf algebra that quantizes
$\mathfrak{n}_{D}^{-}$. This algebra has many similar properties to
$U_{q}^{-}(\mathfrak{g})$, in many cases being a Nichols algebra and therefore
completely determined by its associated braiding.


title: Parton Distributions for the LHC

abstract:
  We present a preliminary set of updated NLO parton distributions. For the
first time we have a quantitative extraction of the strange quark and antiquark
distributions and their uncertainties determined from CCFR and NuTeV dimuon
cross sections. Additional jet data from HERA and the Tevatron improve our
gluon extraction. Lepton asymmetry data and neutrino structure functions
improve the flavour separation, particularly constraining the down quark
valence distribution.


title: Challenges and Opportunities of Evolutionary Robotics

abstract:
  Robotic hardware designs are becoming more complex as the variety and number
of on-board sensors increase and as greater computational power is provided in
ever-smaller packages on-board robots. These advances in hardware, however, do
not automatically translate into better software for controlling complex
robots. Evolutionary techniques hold the potential to solve many difficult
problems in robotics which defy simple conventional approaches, but present
many challenges as well. Numerous disciplines including artificial life,
cognitive science and neural networks, rule-based systems, behavior-based
control, genetic algorithms and other forms of evolutionary computation have
contributed to shaping the current state of evolutionary robotics. This paper
provides an overview of developments in the emerging field of evolutionary
robotics, and discusses some of the opportunities and challenges which
currently face practitioners in the field.


title:
Measurement of the ttbar production cross section in ppbar collisions
  using dilepton events

abstract:
  We present a measurement of the ttbar pair production cross section in ppbar
collisions at sqrt(s) = 1.96 TeV utilizing approximately 425 pb-1 of data
collected with the D0 detector. We consider decay channels containing two high
pT charged leptons (either e or \mu) from leptonic decays of both top-daughter
W bosons. These were gathered using four sets of selection criteria, three of
which required that a pair of fully identified leptons (i.e., e\mu, ee, or
\mu\mu) be found. The fourth approach imposed less restrictive criteria on one
of the lepton candidates and required that at least one hadronic jet in each
event be tagged as containing a b quark. For a top quark mass of 175 GeV, the
measured cross section is 7.4 +/-1.4(stat} +/- 1.0(syst) pb.


title: Update of Parton Distributions at NNLO

abstract:
  We present a new set of parton distributions obtained at NNLO. These differ
from the previous sets available at NNLO due to improvements in the theoretical
treatment. In particular we include a full treatment of heavy flavours in the
region near the quark mass. In this way, an essentially complete set of NNLO
partons is presented for the first time. The improved treatment leads to a
significant change in the gluon and heavy quark distributions, and a larger
value of the QCD coupling at NNLO, alpha_S(M_Z^2) = 0.1191 +/- 0.002(expt.) +/-
0.003(theory). Indirectly this also leads to a change in the light partons at
small x and modifications of our predictions for W and Z production at the LHC.
As well as the best-fit set of partons, we also provide 30 additional sets
representing the uncertainties of the partons obtained using the Hessian
approach.


title: Permutation actions on equivariant cohomology

abstract:
  This survey paper describes two geometric representations of the permutation
group using the tools of toric topology. These actions are extremely useful for
computational problems in Schubert calculus. The (torus) equivariant cohomology
of the flag variety is constructed using the combinatorial description of
Goresky-Kottwitz-MacPherson, discussed in detail. Two permutation
representations on equivariant and ordinary cohomology are identified in terms
of irreducible representations of the permutation group. We show how to use the
permutation actions to construct divided difference operators and to give
formulas for some localizations of certain equivariant classes.
  This paper includes several new results, in particular a new proof of the
Chevalley-Monk formula and a proof that one of the natural permutation
representations on the equivariant cohomology of the flag variety is the
regular representation. Many examples, exercises, and open questions are
provided.


title: What Gamma-Ray Bursts Explode Into

abstract:
  The association of long gamma-ray bursts (GRBs) with Type Ib/c supernovae
implies that they explode into the winds of their Wolf-Rayet progenitor stars.
Although the evolution of some GRB afterglows is consistent with expansion into
a free wind, there is also good evidence for expansion into a constant density
medium. The evidence includes the evolution of X-ray afterglows (when X-rays
are below the cooling frequency), the evolution of the pre-jet break optical
and X-ray afterglow, and the sharp turn-on observed for some afterglows. Recent
observations of short bursts, which are expected to be interacting with a
constant density medium, provide a check on the standard afterglow model.
Although radio observations do not support the constant density model for long
bursts in some cases, the evidence for constant density interaction is strong.
The most plausible way to produce such a medium around a massive star is to
shock the progenitor wind. This requires a smaller termination shock than would
be expected, possibly due to a high pressure surroundings, a high progenitor
velocity, or the particular evolution leading to a GRB. However, the need for
the termination shock near the deceleration radius cannot be plausibly
accomodated and may indicate that some long bursts have compact binary
progenitors and explode directly into the interstellar medium.


title:
Financial equilibria in the semimartingale setting: complete markets and
  markets with withdrawal constraints

abstract:
  Existence of stochastic financial equilibria giving rise to semimartingale
asset prices is established under a general class of assumptions. These
equilibria are expressed in real terms and span complete markets or markets
with withdrawal constraints.We deal with random endowment density streams which
admit jumps and general time-dependent utility functions on which only
regularity conditions are imposed. As an integral part of the proof of the main
result, we establish a novel characterization of semimartingale functions.


title: The Nature of Generic Cosmological Singularities

abstract:
  The existence of a singularity by definition implies a preferred scale--the
affine parameter distance from/to the singularity of a causal geodesic that is
used to define it. However, this variable scale is also captured by the
expansion along the geodesic, and this can be used to obtain a regularized
state space picture by means of a conformal transformation that factors out the
expansion. This leads to the conformal `Hubble-normalized' orthonormal frame
approach which allows one to translate methods and results concerning spatially
homogeneous models into the generic inhomogeneous context, which in turn
enables one to derive the dynamical nature of generic cosmological
singularities. Here we describe this approach and outline the derivation of the
`cosmological billiard attractor,' which describes the generic dynamical
asymptotic behavior towards a generic spacelike singularity. We also compare
the `dynamical systems picture' resulting from this approach with other work on
generic spacelike singularities: the metric approach of Belinskii, Lifschitz,
and Khalatnikov, and the recent Iwasawa based Hamiltonian method used by
Damour, Henneaux, and Nicolai; in particular we show that the cosmological
billiards obtained by the latter and the cosmological billiard attractor form
complementary `dual' descriptions of the generic asymptotic dynamics of generic
spacelike singularities.


title: Jordan Triple Elementary Maps on Rings

abstract:
  We prove that Jordan triple elementary surjective maps on unital rings
containing a nontrivial idempotent are automatically additive.